1 # SOME DESCRIPTIVE TITLE
2 # Copyright (C) YEAR Free Software Foundation, Inc.
3 # This file is distributed under the same license as the PACKAGE package.
4 # FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
9 "Project-Id-Version: PACKAGE VERSION\n"
10 "POT-Creation-Date: 2015-01-21 20:35+0900\n"
11 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
12 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
13 "Language-Team: LANGUAGE <LL@li.org>\n"
16 "Content-Type: text/plain; charset=UTF-8\n"
17 "Content-Transfer-Encoding: 8bit\n"
20 #: build/C/man7/arp.7:13
26 #: build/C/man7/arp.7:13
32 #: build/C/man7/arp.7:13 build/C/man3/cmsg.3:11 build/C/man7/ddp.7:12 build/C/man5/gai.conf.5:19 build/C/man1/getent.1:24 build/C/man3/getipnodebyname.3:26 build/C/man2/getpeername.2:42 build/C/man5/host.conf.5:26 build/C/man7/hostname.7:39 build/C/man5/hosts.5:27 build/C/man5/hosts.equiv.5:6 build/C/man7/icmp.7:12 build/C/man3/inet_net_pton.3:26 build/C/man3/inet_ntop.3:26 build/C/man3/inet_pton.3:27 build/C/man7/ip.7:36 build/C/man7/ipv6.7:86 build/C/man7/netdevice.7:18 build/C/man5/nss.5:19 build/C/man5/nsswitch.conf.5:25 build/C/man7/packet.7:12 build/C/man5/protocols.5:29 build/C/man7/raw.7:13 build/C/man3/rcmd.3:43 build/C/man3/rexec.3:41 build/C/man5/services.5:34 build/C/man2/shutdown.2:40 build/C/man7/tcp.7:76 build/C/man7/udp.7:12 build/C/man7/udplite.7:27 build/C/man7/unix.7:20 build/C/man7/x25.7:12
38 #: build/C/man7/arp.7:13 build/C/man3/byteorder.3:32 build/C/man3/cmsg.3:11 build/C/man7/ddp.7:12 build/C/man3/endian.3:28 build/C/man3/ether_aton.3:31 build/C/man5/gai.conf.5:19 build/C/man3/getaddrinfo.3:44 build/C/man3/getaddrinfo_a.3:29 build/C/man3/gethostbyname.3:38 build/C/man3/getipnodebyname.3:26 build/C/man3/getnameinfo.3:10 build/C/man3/getnetent.3:30 build/C/man3/getnetent_r.3:26 build/C/man2/getpeername.2:42 build/C/man3/getprotoent.3:30 build/C/man3/getprotoent_r.3:26 build/C/man3/getservent.3:34 build/C/man3/getservent_r.3:26 build/C/man7/hostname.7:39 build/C/man5/hosts.5:27 build/C/man5/hosts.equiv.5:6 build/C/man7/icmp.7:12 build/C/man3/inet.3:42 build/C/man3/inet_net_pton.3:26 build/C/man3/inet_ntop.3:26 build/C/man3/inet_pton.3:27 build/C/man7/ip.7:36 build/C/man7/ipv6.7:86 build/C/man7/netdevice.7:18 build/C/man8/nscd.8:23 build/C/man5/nscd.conf.5:20 build/C/man5/nss.5:19 build/C/man5/nsswitch.conf.5:25 build/C/man7/packet.7:12 build/C/man5/protocols.5:29 build/C/man7/raw.7:13 build/C/man3/rcmd.3:43 build/C/man5/resolv.conf.5:23 build/C/man3/resolver.3:32 build/C/man3/rexec.3:41 build/C/man5/services.5:34 build/C/man3/setnetgrent.3:10 build/C/man2/shutdown.2:40 build/C/man7/tcp.7:76 build/C/man7/udp.7:12 build/C/man7/udplite.7:27 build/C/man7/unix.7:20 build/C/man7/x25.7:12
40 msgid "Linux Programmer's Manual"
44 #: build/C/man7/arp.7:14 build/C/man3/byteorder.3:33 build/C/man3/cmsg.3:12 build/C/man7/ddp.7:13 build/C/man3/endian.3:29 build/C/man3/ether_aton.3:32 build/C/man5/gai.conf.5:20 build/C/man3/getaddrinfo.3:45 build/C/man3/getaddrinfo_a.3:30 build/C/man1/getent.1:25 build/C/man3/gethostbyname.3:39 build/C/man3/getipnodebyname.3:27 build/C/man3/getnameinfo.3:11 build/C/man3/getnetent.3:31 build/C/man3/getnetent_r.3:27 build/C/man2/getpeername.2:43 build/C/man3/getprotoent.3:31 build/C/man3/getprotoent_r.3:27 build/C/man3/getservent.3:35 build/C/man3/getservent_r.3:27 build/C/man5/host.conf.5:27 build/C/man7/hostname.7:40 build/C/man5/hosts.5:28 build/C/man5/hosts.equiv.5:7 build/C/man7/icmp.7:13 build/C/man3/inet.3:43 build/C/man3/inet_net_pton.3:27 build/C/man3/inet_ntop.3:27 build/C/man3/inet_pton.3:28 build/C/man7/ip.7:37 build/C/man7/ipv6.7:87 build/C/man7/netdevice.7:19 build/C/man5/networks.5:27 build/C/man8/nscd.8:24 build/C/man5/nscd.conf.5:21 build/C/man5/nss.5:20 build/C/man5/nsswitch.conf.5:26 build/C/man7/packet.7:13 build/C/man5/protocols.5:30 build/C/man7/raw.7:14 build/C/man3/rcmd.3:44 build/C/man5/resolv.conf.5:25 build/C/man3/resolver.3:33 build/C/man3/rexec.3:42 build/C/man5/services.5:35 build/C/man3/setnetgrent.3:11 build/C/man2/shutdown.2:41 build/C/man7/tcp.7:77 build/C/man7/udp.7:13 build/C/man7/udplite.7:28 build/C/man7/unix.7:21 build/C/man7/x25.7:13
50 #: build/C/man7/arp.7:16
51 msgid "arp - Linux ARP kernel module."
55 #: build/C/man7/arp.7:16 build/C/man3/byteorder.3:48 build/C/man3/cmsg.3:37 build/C/man7/ddp.7:23 build/C/man3/endian.3:53 build/C/man3/ether_aton.3:57 build/C/man5/gai.conf.5:22 build/C/man3/getaddrinfo.3:76 build/C/man3/getaddrinfo_a.3:50 build/C/man1/getent.1:30 build/C/man3/gethostbyname.3:129 build/C/man3/getipnodebyname.3:44 build/C/man3/getnameinfo.3:32 build/C/man3/getnetent.3:48 build/C/man3/getnetent_r.3:62 build/C/man2/getpeername.2:50 build/C/man3/getprotoent.3:48 build/C/man3/getprotoent_r.3:59 build/C/man3/getservent.3:52 build/C/man3/getservent_r.3:59 build/C/man5/host.conf.5:29 build/C/man7/hostname.7:42 build/C/man5/hosts.5:32 build/C/man5/hosts.equiv.5:11 build/C/man7/icmp.7:15 build/C/man3/inet.3:75 build/C/man3/inet_net_pton.3:61 build/C/man3/inet_ntop.3:36 build/C/man3/inet_pton.3:36 build/C/man7/ip.7:53 build/C/man7/ipv6.7:99 build/C/man7/netdevice.7:25 build/C/man5/networks.5:29 build/C/man8/nscd.8:26 build/C/man5/nscd.conf.5:23 build/C/man5/nss.5:22 build/C/man5/nsswitch.conf.5:28 build/C/man7/packet.7:25 build/C/man5/protocols.5:32 build/C/man7/raw.7:22 build/C/man3/rcmd.3:92 build/C/man5/resolv.conf.5:29 build/C/man3/resolver.3:85 build/C/man3/rexec.3:56 build/C/man5/services.5:37 build/C/man3/setnetgrent.3:44 build/C/man2/shutdown.2:47 build/C/man7/tcp.7:87 build/C/man7/udp.7:23 build/C/man7/udplite.7:38 build/C/man7/unix.7:31 build/C/man7/x25.7:21
61 #: build/C/man7/arp.7:24
63 "This kernel protocol module implements the Address Resolution Protocol "
64 "defined in RFC\\ 826. It is used to convert between Layer2 hardware "
65 "addresses and IPv4 protocol addresses on directly connected networks. The "
66 "user normally doesn't interact directly with this module except to configure "
67 "it; instead it provides a service for other protocols in the kernel."
71 #: build/C/man7/arp.7:37
73 "A user process can receive ARP packets by using B<packet>(7) sockets. "
74 "There is also a mechanism for managing the ARP cache in user-space by using "
75 "B<netlink>(7) sockets. The ARP table can also be controlled via "
76 "B<ioctl>(2) on any B<AF_INET> socket."
80 #: build/C/man7/arp.7:49
82 "The ARP module maintains a cache of mappings between hardware addresses and "
83 "protocol addresses. The cache has a limited size so old and less frequently "
84 "used entries are garbage-collected. Entries which are marked as permanent "
85 "are never deleted by the garbage-collector. The cache can be directly "
86 "manipulated by the use of ioctls and its behavior can be tuned by the "
87 "I</proc> interfaces described below."
91 #: build/C/man7/arp.7:72
93 "When there is no positive feedback for an existing mapping after some time "
94 "(see the I</proc> interfaces below), a neighbor cache entry is considered "
95 "stale. Positive feedback can be gotten from a higher layer; for example "
96 "from a successful TCP ACK. Other protocols can signal forward progress "
97 "using the B<MSG_CONFIRM> flag to B<sendmsg>(2). When there is no forward "
98 "progress, ARP tries to reprobe. It first tries to ask a local arp daemon "
99 "B<app_solicit> times for an updated MAC address. If that fails and an old "
100 "MAC address is known, a unicast probe is sent B<ucast_solicit> times. If "
101 "that fails too, it will broadcast a new ARP request to the network. "
102 "Requests are sent only when there is data queued for sending."
106 #: build/C/man7/arp.7:77
108 "Linux will automatically add a nonpermanent proxy arp entry when it receives "
109 "a request for an address it forwards to and proxy arp is enabled on the "
110 "receiving interface. When there is a reject route for the target, no proxy "
111 "arp entry is added."
115 #: build/C/man7/arp.7:77 build/C/man7/ddp.7:144 build/C/man7/ip.7:1075 build/C/man7/netdevice.7:64 build/C/man7/packet.7:479 build/C/man7/tcp.7:1127 build/C/man7/udp.7:202 build/C/man7/unix.7:367
121 #: build/C/man7/arp.7:84
123 "Three ioctls are available on all B<AF_INET> sockets. They take a pointer "
124 "to a I<struct arpreq> as their argument."
128 #: build/C/man7/arp.7:94
132 " struct sockaddr arp_pa; /* protocol address */\n"
133 " struct sockaddr arp_ha; /* hardware address */\n"
134 " int arp_flags; /* flags */\n"
135 " struct sockaddr arp_netmask; /* netmask of protocol address */\n"
136 " char arp_dev[16];\n"
141 #: build/C/man7/arp.7:103
143 "B<SIOCSARP>, B<SIOCDARP> and B<SIOCGARP> respectively set, delete and get an "
144 "ARP mapping. Setting and deleting ARP maps are privileged operations and "
145 "may be performed only by a process with the B<CAP_NET_ADMIN> capability or "
146 "an effective UID of 0."
150 #: build/C/man7/arp.7:113
152 "I<arp_pa> must be an B<AF_INET> address and I<arp_ha> must have the same "
153 "type as the device which is specified in I<arp_dev>. I<arp_dev> is a "
154 "zero-terminated string which names a device."
158 #: build/C/man7/arp.7:118
160 msgid "I<arp_flags>\n"
164 #: build/C/man7/arp.7:119
166 msgid "flag:meaning\n"
170 #: build/C/man7/arp.7:120
172 msgid "ATF_COM:Lookup complete\n"
176 #: build/C/man7/arp.7:121
178 msgid "ATF_PERM:Permanent entry\n"
182 #: build/C/man7/arp.7:122
184 msgid "ATF_PUBL:Publish entry\n"
188 #: build/C/man7/arp.7:123
190 msgid "ATF_USETRAILERS:Trailers requested\n"
194 #: build/C/man7/arp.7:124
196 msgid "ATF_NETMASK:Use a netmask\n"
200 #: build/C/man7/arp.7:125
202 msgid "ATF_DONTPUB:Don't answer\n"
206 #: build/C/man7/arp.7:138
208 "If the B<ATF_NETMASK> flag is set, then I<arp_netmask> should be valid. "
209 "Linux 2.2 does not support proxy network ARP entries, so this should be set "
210 "to 0xffffffff, or 0 to remove an existing proxy arp entry. "
211 "B<ATF_USETRAILERS> is obsolete and should not be used."
215 #: build/C/man7/arp.7:138 build/C/man7/ddp.7:122 build/C/man7/icmp.7:41 build/C/man7/ip.7:926 build/C/man7/tcp.7:219 build/C/man7/udp.7:137
217 msgid "/proc interfaces"
221 #: build/C/man7/arp.7:151
223 "ARP supports a range of I</proc> interfaces to configure parameters on a "
224 "global or per-interface basis. The interfaces can be accessed by reading or "
225 "writing the I</proc/sys/net/ipv4/neigh/*/*> files. Each interface in the "
226 "system has its own directory in I</proc/sys/net/ipv4/neigh/>. The setting "
227 "in the \"default\" directory is used for all newly created devices. Unless "
228 "otherwise specified, time-related interfaces are specified in seconds."
232 #: build/C/man7/arp.7:151
234 msgid "I<anycast_delay> (since Linux 2.2)"
239 #: build/C/man7/arp.7:158
241 "The maximum number of jiffies to delay before replying to a IPv6 neighbor "
242 "solicitation message. Anycast support is not yet implemented. Defaults to "
247 #: build/C/man7/arp.7:158
249 msgid "I<app_solicit> (since Linux 2.2)"
254 #: build/C/man7/arp.7:165
256 "The maximum number of probes to send to the user space ARP daemon via "
257 "netlink before dropping back to multicast probes (see I<mcast_solicit>). "
262 #: build/C/man7/arp.7:165
264 msgid "I<base_reachable_time> (since Linux 2.2)"
269 #: build/C/man7/arp.7:176
271 "Once a neighbor has been found, the entry is considered to be valid for at "
272 "least a random value between I<base_reachable_time>/2 and "
273 "3*I<base_reachable_time>/2. An entry's validity will be extended if it "
274 "receives positive feedback from higher level protocols. Defaults to 30 "
275 "seconds. This file is now obsolete in favor of I<base_reachable_time_ms>."
279 #: build/C/man7/arp.7:176
281 msgid "I<base_reachable_time_ms> (since Linux 2.6.12)"
285 #: build/C/man7/arp.7:182
287 "As for I<base_reachable_time>, but measures time in milliseconds. Defaults "
288 "to 30000 milliseconds."
292 #: build/C/man7/arp.7:182
294 msgid "I<delay_first_probe_time> (since Linux 2.2)"
299 #: build/C/man7/arp.7:188
301 "Delay before first probe after it has been decided that a neighbor is "
302 "stale. Defaults to 5 seconds."
306 #: build/C/man7/arp.7:188
308 msgid "I<gc_interval> (since Linux 2.2)"
313 #: build/C/man7/arp.7:194
315 "How frequently the garbage collector for neighbor entries should attempt to "
316 "run. Defaults to 30 seconds."
320 #: build/C/man7/arp.7:194
322 msgid "I<gc_stale_time> (since Linux 2.2)"
327 #: build/C/man7/arp.7:201
329 "Determines how often to check for stale neighbor entries. When a neighbor "
330 "entry is considered stale, it is resolved again before sending data to it. "
331 "Defaults to 60 seconds."
335 #: build/C/man7/arp.7:201
337 msgid "I<gc_thresh1> (since Linux 2.2)"
342 #: build/C/man7/arp.7:208
344 "The minimum number of entries to keep in the ARP cache. The garbage "
345 "collector will not run if there are fewer than this number of entries in the "
346 "cache. Defaults to 128."
350 #: build/C/man7/arp.7:208
352 msgid "I<gc_thresh2> (since Linux 2.2)"
357 #: build/C/man7/arp.7:215
359 "The soft maximum number of entries to keep in the ARP cache. The garbage "
360 "collector will allow the number of entries to exceed this for 5 seconds "
361 "before collection will be performed. Defaults to 512."
365 #: build/C/man7/arp.7:215
367 msgid "I<gc_thresh3> (since Linux 2.2)"
372 #: build/C/man7/arp.7:222
374 "The hard maximum number of entries to keep in the ARP cache. The garbage "
375 "collector will always run if there are more than this number of entries in "
376 "the cache. Defaults to 1024."
380 #: build/C/man7/arp.7:222
382 msgid "I<locktime> (since Linux 2.2)"
387 #: build/C/man7/arp.7:229
389 "The minimum number of jiffies to keep an ARP entry in the cache. This "
390 "prevents ARP cache thrashing if there is more than one potential mapping "
391 "(generally due to network misconfiguration). Defaults to 1 second."
395 #: build/C/man7/arp.7:229
397 msgid "I<mcast_solicit> (since Linux 2.2)"
402 #: build/C/man7/arp.7:235
404 "The maximum number of attempts to resolve an address by multicast/broadcast "
405 "before marking the entry as unreachable. Defaults to 3."
409 #: build/C/man7/arp.7:235
411 msgid "I<proxy_delay> (since Linux 2.2)"
416 #: build/C/man7/arp.7:243
418 "When an ARP request for a known proxy-ARP address is received, delay up to "
419 "I<proxy_delay> jiffies before replying. This is used to prevent network "
420 "flooding in some cases. Defaults to 0.8 seconds."
424 #: build/C/man7/arp.7:243
426 msgid "I<proxy_qlen> (since Linux 2.2)"
431 #: build/C/man7/arp.7:248
433 "The maximum number of packets which may be queued to proxy-ARP addresses. "
438 #: build/C/man7/arp.7:248
440 msgid "I<retrans_time> (since Linux 2.2)"
445 #: build/C/man7/arp.7:255
447 "The number of jiffies to delay before retransmitting a request. Defaults to "
448 "1 second. This file is now obsolete in favor of I<retrans_time_ms>."
452 #: build/C/man7/arp.7:255
454 msgid "I<retrans_time_ms> (since Linux 2.6.12)"
458 #: build/C/man7/arp.7:259
460 "The number of milliseconds to delay before retransmitting a request. "
461 "Defaults to 1000 milliseconds."
465 #: build/C/man7/arp.7:259
467 msgid "I<ucast_solicit> (since Linux 2.2)"
472 #: build/C/man7/arp.7:266
474 "The maximum number of attempts to send unicast probes before asking the ARP "
475 "daemon (see I<app_solicit>). Defaults to 3."
479 #: build/C/man7/arp.7:266
481 msgid "I<unres_qlen> (since Linux 2.2)"
486 #: build/C/man7/arp.7:272
488 "The maximum number of packets which may be queued for each unresolved "
489 "address by other network layers. Defaults to 3."
493 #: build/C/man7/arp.7:272 build/C/man7/ddp.7:221 build/C/man3/endian.3:74 build/C/man3/getnameinfo.3:203 build/C/man7/icmp.7:161 build/C/man7/ipv6.7:362 build/C/man7/packet.7:532 build/C/man7/raw.7:175 build/C/man3/rcmd.3:262 build/C/man3/rexec.3:138 build/C/man7/tcp.7:1244 build/C/man7/udp.7:251 build/C/man7/udplite.7:132 build/C/man7/unix.7:484 build/C/man7/x25.7:100
499 #: build/C/man7/arp.7:279
501 "The I<struct arpreq> changed in Linux 2.0 to include the I<arp_dev> member "
502 "and the ioctl numbers changed at the same time. Support for the old ioctls "
503 "was dropped in Linux 2.2."
507 #: build/C/man7/arp.7:285
509 "Support for proxy arp entries for networks (netmask not equal 0xffffffff) "
510 "was dropped in Linux 2.2. It is replaced by automatic proxy arp setup by "
511 "the kernel for all reachable hosts on other interfaces (when forwarding and "
512 "proxy arp is enabled for the interface)."
516 #: build/C/man7/arp.7:289
517 msgid "The I<neigh/*> interfaces did not exist before Linux 2.2."
521 #: build/C/man7/arp.7:289 build/C/man7/ddp.7:244 build/C/man3/ether_aton.3:151 build/C/man3/gethostbyname.3:438 build/C/man3/inet_ntop.3:112 build/C/man3/inet_pton.3:150 build/C/man7/ip.7:1245 build/C/man7/ipv6.7:396 build/C/man7/netdevice.7:359 build/C/man7/packet.7:601 build/C/man7/raw.7:252 build/C/man3/rcmd.3:278 build/C/man3/rexec.3:158 build/C/man2/shutdown.2:104 build/C/man7/tcp.7:1251 build/C/man7/udplite.7:134 build/C/man7/unix.7:521 build/C/man7/x25.7:102
527 #: build/C/man7/arp.7:293
529 "Some timer settings are specified in jiffies, which is architecture- and "
530 "kernel version-dependent; see B<time>(7)."
534 #: build/C/man7/arp.7:299
536 "There is no way to signal positive feedback from user space. This means "
537 "connection-oriented protocols implemented in user space will generate "
538 "excessive ARP traffic, because ndisc will regularly reprobe the MAC "
539 "address. The same problem applies for some kernel protocols (e.g., NFS over "
544 #: build/C/man7/arp.7:302
546 "This man page mashes together functionality that is IPv4-specific with "
547 "functionality that is shared between IPv4 and IPv6."
551 #: build/C/man7/arp.7:302 build/C/man3/byteorder.3:92 build/C/man3/cmsg.3:222 build/C/man7/ddp.7:249 build/C/man3/endian.3:151 build/C/man3/ether_aton.3:157 build/C/man5/gai.conf.5:93 build/C/man3/getaddrinfo.3:828 build/C/man3/getaddrinfo_a.3:600 build/C/man1/getent.1:368 build/C/man3/gethostbyname.3:443 build/C/man3/getipnodebyname.3:266 build/C/man3/getnameinfo.3:282 build/C/man3/getnetent.3:154 build/C/man3/getnetent_r.3:145 build/C/man2/getpeername.2:143 build/C/man3/getprotoent.3:142 build/C/man3/getprotoent_r.3:237 build/C/man3/getservent.3:159 build/C/man3/getservent_r.3:241 build/C/man5/host.conf.5:199 build/C/man7/hostname.7:85 build/C/man5/hosts.5:115 build/C/man5/hosts.equiv.5:84 build/C/man7/icmp.7:191 build/C/man3/inet.3:305 build/C/man3/inet_net_pton.3:390 build/C/man3/inet_ntop.3:118 build/C/man3/inet_pton.3:215 build/C/man7/ip.7:1272 build/C/man7/ipv6.7:407 build/C/man7/netdevice.7:373 build/C/man5/networks.5:74 build/C/man8/nscd.8:85 build/C/man5/nscd.conf.5:239 build/C/man5/nss.5:110 build/C/man5/nsswitch.conf.5:352 build/C/man7/packet.7:631 build/C/man5/protocols.5:81 build/C/man7/raw.7:269 build/C/man3/rcmd.3:285 build/C/man5/resolv.conf.5:301 build/C/man3/resolver.3:274 build/C/man3/rexec.3:167 build/C/man5/services.5:210 build/C/man3/setnetgrent.3:107 build/C/man2/shutdown.2:113 build/C/man7/tcp.7:1263 build/C/man7/udp.7:256 build/C/man7/udplite.7:146 build/C/man7/unix.7:616 build/C/man7/x25.7:118
557 #: build/C/man7/arp.7:305
558 msgid "B<capabilities>(7), B<ip>(7)"
562 #: build/C/man7/arp.7:309
564 "RFC\\ 826 for a description of ARP. RFC\\ 2461 for a description of IPv6 "
565 "neighbor discovery and the base algorithms used. Linux 2.2+ IPv4 ARP uses "
566 "the IPv6 algorithms when applicable."
570 #: build/C/man3/byteorder.3:32
576 #: build/C/man3/byteorder.3:32
582 #: build/C/man3/byteorder.3:32 build/C/man3/endian.3:28 build/C/man3/ether_aton.3:31 build/C/man3/getaddrinfo.3:44 build/C/man3/getaddrinfo_a.3:29 build/C/man3/getnameinfo.3:10 build/C/man3/getnetent.3:30 build/C/man3/getnetent_r.3:26 build/C/man3/getprotoent.3:30 build/C/man3/getprotoent_r.3:26 build/C/man3/getservent.3:34 build/C/man3/getservent_r.3:26 build/C/man3/inet.3:42 build/C/man8/nscd.8:23 build/C/man5/nscd.conf.5:20 build/C/man3/resolver.3:32 build/C/man3/setnetgrent.3:10
588 #: build/C/man3/byteorder.3:36
590 "htonl, htons, ntohl, ntohs - convert values between host and network byte "
595 #: build/C/man3/byteorder.3:36 build/C/man3/cmsg.3:14 build/C/man7/ddp.7:15 build/C/man3/endian.3:33 build/C/man3/ether_aton.3:35 build/C/man3/getaddrinfo.3:48 build/C/man3/getaddrinfo_a.3:33 build/C/man1/getent.1:27 build/C/man3/gethostbyname.3:46 build/C/man3/getipnodebyname.3:30 build/C/man3/getnameinfo.3:13 build/C/man3/getnetent.3:34 build/C/man3/getnetent_r.3:30 build/C/man2/getpeername.2:45 build/C/man3/getprotoent.3:34 build/C/man3/getprotoent_r.3:30 build/C/man3/getservent.3:38 build/C/man3/getservent_r.3:30 build/C/man5/hosts.5:30 build/C/man3/inet.3:46 build/C/man3/inet_net_pton.3:29 build/C/man3/inet_ntop.3:29 build/C/man3/inet_pton.3:30 build/C/man7/ip.7:39 build/C/man7/ipv6.7:89 build/C/man7/netdevice.7:21 build/C/man7/packet.7:15 build/C/man7/raw.7:16 build/C/man3/rcmd.3:48 build/C/man5/resolv.conf.5:27 build/C/man3/resolver.3:36 build/C/man3/rexec.3:44 build/C/man3/setnetgrent.3:14 build/C/man2/shutdown.2:43 build/C/man7/tcp.7:79 build/C/man7/udp.7:15 build/C/man7/udplite.7:30 build/C/man7/unix.7:23 build/C/man7/x25.7:15
601 #: build/C/man3/byteorder.3:39 build/C/man3/inet_net_pton.3:32 build/C/man3/inet_ntop.3:32 build/C/man3/inet_pton.3:33
603 msgid "B<#include E<lt>arpa/inet.hE<gt>>\n"
607 #: build/C/man3/byteorder.3:41
609 msgid "B<uint32_t htonl(uint32_t >I<hostlong>B<);>\n"
613 #: build/C/man3/byteorder.3:43
615 msgid "B<uint16_t htons(uint16_t >I<hostshort>B<);>\n"
619 #: build/C/man3/byteorder.3:45
621 msgid "B<uint32_t ntohl(uint32_t >I<netlong>B<);>\n"
625 #: build/C/man3/byteorder.3:47
627 msgid "B<uint16_t ntohs(uint16_t >I<netshort>B<);>\n"
631 #: build/C/man3/byteorder.3:54
633 "The B<htonl>() function converts the unsigned integer I<hostlong> from host "
634 "byte order to network byte order."
638 #: build/C/man3/byteorder.3:60
640 "The B<htons>() function converts the unsigned short integer I<hostshort> "
641 "from host byte order to network byte order."
645 #: build/C/man3/byteorder.3:66
647 "The B<ntohl>() function converts the unsigned integer I<netlong> from "
648 "network byte order to host byte order."
652 #: build/C/man3/byteorder.3:72
654 "The B<ntohs>() function converts the unsigned short integer I<netshort> "
655 "from network byte order to host byte order."
659 #: build/C/man3/byteorder.3:76
661 "On the i386 the host byte order is Least Significant Byte first, whereas the "
662 "network byte order, as used on the Internet, is Most Significant Byte first."
666 #: build/C/man3/byteorder.3:76 build/C/man3/ether_aton.3:127 build/C/man3/rexec.3:142
672 #: build/C/man3/byteorder.3:77 build/C/man3/rexec.3:143
674 msgid "Multithreading (see pthreads(7))"
678 #: build/C/man3/byteorder.3:85
680 "The B<htonl>(), B<htons>(), B<ntohl>(), and B<ntohs>() functions are "
685 #: build/C/man3/byteorder.3:85 build/C/man3/cmsg.3:141 build/C/man3/endian.3:76 build/C/man3/ether_aton.3:149 build/C/man3/getaddrinfo.3:595 build/C/man3/getaddrinfo_a.3:305 build/C/man3/gethostbyname.3:317 build/C/man3/getipnodebyname.3:258 build/C/man3/getnameinfo.3:206 build/C/man3/getnetent.3:145 build/C/man3/getnetent_r.3:141 build/C/man2/getpeername.2:101 build/C/man3/getprotoent.3:140 build/C/man3/getprotoent_r.3:131 build/C/man3/getservent.3:157 build/C/man3/getservent_r.3:130 build/C/man3/inet.3:218 build/C/man3/inet_net_pton.3:159 build/C/man3/inet_ntop.3:100 build/C/man3/inet_pton.3:129 build/C/man3/rcmd.3:270 build/C/man3/resolver.3:272 build/C/man3/rexec.3:149 build/C/man3/setnetgrent.3:92 build/C/man2/shutdown.2:91
687 msgid "CONFORMING TO"
691 #: build/C/man3/byteorder.3:87 build/C/man3/inet_pton.3:131
692 msgid "POSIX.1-2001."
696 #: build/C/man3/byteorder.3:92
698 "Some systems require the inclusion of I<E<lt>netinet/in.hE<gt>> instead of "
699 "I<E<lt>arpa/inet.hE<gt>>."
703 #: build/C/man3/byteorder.3:95
704 msgid "B<endian>(3), B<gethostbyname>(3), B<getservent>(3)"
708 #: build/C/man3/cmsg.3:11
714 #: build/C/man3/cmsg.3:11 build/C/man5/resolv.conf.5:23 build/C/man7/unix.7:20
720 #: build/C/man3/cmsg.3:14
721 msgid "CMSG_ALIGN, CMSG_SPACE, CMSG_NXTHDR, CMSG_FIRSTHDR - access ancillary data"
725 #: build/C/man3/cmsg.3:16 build/C/man7/ddp.7:17 build/C/man2/getpeername.2:47 build/C/man7/ip.7:41 build/C/man7/ipv6.7:91 build/C/man7/raw.7:18 build/C/man2/shutdown.2:45 build/C/man7/tcp.7:81 build/C/man7/udp.7:17 build/C/man7/udplite.7:32 build/C/man7/unix.7:25 build/C/man7/x25.7:17
726 msgid "B<#include E<lt>sys/socket.hE<gt>>"
730 #: build/C/man3/cmsg.3:18
731 msgid "B<struct cmsghdr *CMSG_FIRSTHDR(struct msghdr *>I<msgh>B<);>"
735 #: build/C/man3/cmsg.3:20
737 "B<struct cmsghdr *CMSG_NXTHDR(struct msghdr *>I<msgh>B<, struct cmsghdr "
742 #: build/C/man3/cmsg.3:22
743 msgid "B<size_t CMSG_ALIGN(size_t >I<length>B<);>"
747 #: build/C/man3/cmsg.3:24
748 msgid "B<size_t CMSG_SPACE(size_t >I<length>B<);>"
752 #: build/C/man3/cmsg.3:26
753 msgid "B<size_t CMSG_LEN(size_t >I<length>B<);>"
757 #: build/C/man3/cmsg.3:28
758 msgid "B<unsigned char *CMSG_DATA(struct cmsghdr *>I<cmsg>B<);>"
762 #: build/C/man3/cmsg.3:36
766 " socklen_t cmsg_len; /* data byte count, including header */\n"
767 " int cmsg_level; /* originating protocol */\n"
768 " int cmsg_type; /* protocol-specific type */\n"
769 " /* followed by unsigned char cmsg_data[]; */\n"
774 #: build/C/man3/cmsg.3:51
776 "These macros are used to create and access control messages (also called "
777 "ancillary data) that are not a part of the socket payload. This control "
778 "information may include the interface the packet was received on, various "
779 "rarely used header fields, an extended error description, a set of file "
780 "descriptors or UNIX credentials. For instance, control messages can be used "
781 "to send additional header fields such as IP options. Ancillary data is sent "
782 "by calling B<sendmsg>(2) and received by calling B<recvmsg>(2). See their "
783 "manual pages for more information."
787 #: build/C/man3/cmsg.3:62
789 "Ancillary data is a sequence of I<struct cmsghdr> structures with appended "
790 "data. This sequence should be accessed using only the macros described in "
791 "this manual page and never directly. See the specific protocol man pages "
792 "for the available control message types. The maximum ancillary buffer size "
793 "allowed per socket can be set using I</proc/sys/net/core/optmem_max>; see "
798 #: build/C/man3/cmsg.3:69
800 "B<CMSG_FIRSTHDR>() returns a pointer to the first I<cmsghdr> in the "
801 "ancillary data buffer associated with the passed I<msghdr>."
805 #: build/C/man3/cmsg.3:76
807 "B<CMSG_NXTHDR>() returns the next valid I<cmsghdr> after the passed "
808 "I<cmsghdr>. It returns NULL when there isn't enough space left in the "
813 #: build/C/man3/cmsg.3:81
815 "B<CMSG_ALIGN>(), given a length, returns it including the required "
816 "alignment. This is a constant expression."
820 #: build/C/man3/cmsg.3:86
822 "B<CMSG_SPACE>() returns the number of bytes an ancillary element with "
823 "payload of the passed data length occupies. This is a constant expression."
827 #: build/C/man3/cmsg.3:90
828 msgid "B<CMSG_DATA>() returns a pointer to the data portion of a I<cmsghdr>."
832 #: build/C/man3/cmsg.3:101
834 "B<CMSG_LEN>() returns the value to store in the I<cmsg_len> member of the "
835 "I<cmsghdr> structure, taking into account any necessary alignment. It takes "
836 "the data length as an argument. This is a constant expression."
840 #: build/C/man3/cmsg.3:134
842 "To create ancillary data, first initialize the I<msg_controllen> member of "
843 "the I<msghdr> with the length of the control message buffer. Use "
844 "B<CMSG_FIRSTHDR>() on the I<msghdr> to get the first control message and "
845 "B<CMSG_NXTHDR>() to get all subsequent ones. In each control message, "
846 "initialize I<cmsg_len> (with B<CMSG_LEN>()), the other I<cmsghdr> header "
847 "fields, and the data portion using B<CMSG_DATA>(). Finally, the "
848 "I<msg_controllen> field of the I<msghdr> should be set to the sum of the "
849 "B<CMSG_SPACE>() of the length of all control messages in the buffer. For "
850 "more information on the I<msghdr>, see B<recvmsg>(2)."
854 #: build/C/man3/cmsg.3:141
856 "When the control message buffer is too short to store all messages, the "
857 "B<MSG_CTRUNC> flag is set in the I<msg_flags> member of the I<msghdr>."
861 #: build/C/man3/cmsg.3:146
863 "This ancillary data model conforms to the POSIX.1g draft, 4.4BSD-Lite, the "
864 "IPv6 advanced API described in RFC\\ 2292 and SUSv2. B<CMSG_ALIGN>() is a "
869 #: build/C/man3/cmsg.3:146 build/C/man7/ddp.7:226 build/C/man3/endian.3:91 build/C/man3/getaddrinfo.3:600 build/C/man3/getaddrinfo_a.3:308 build/C/man3/gethostbyname.3:341 build/C/man3/getipnodebyname.3:261 build/C/man3/getnameinfo.3:208 build/C/man3/getnetent.3:147 build/C/man2/getpeername.2:105 build/C/man5/host.conf.5:190 build/C/man5/hosts.5:88 build/C/man5/hosts.equiv.5:71 build/C/man7/icmp.7:169 build/C/man3/inet.3:226 build/C/man3/inet_net_pton.3:165 build/C/man3/inet_pton.3:131 build/C/man7/ip.7:1183 build/C/man7/ipv6.7:386 build/C/man7/netdevice.7:341 build/C/man8/nscd.8:60 build/C/man5/nscd.conf.5:232 build/C/man5/nsswitch.conf.5:333 build/C/man7/packet.7:538 build/C/man7/raw.7:187 build/C/man3/setnetgrent.3:103 build/C/man2/shutdown.2:95 build/C/man7/unix.7:490
875 #: build/C/man3/cmsg.3:151
877 "For portability, ancillary data should be accessed using only the macros "
878 "described here. B<CMSG_ALIGN>() is a Linux extension and should not be "
879 "used in portable programs."
883 #: build/C/man3/cmsg.3:161
885 "In Linux, B<CMSG_LEN>(), B<CMSG_DATA>(), and B<CMSG_ALIGN>() are constant "
886 "expressions (assuming their argument is constant); this could be used to "
887 "declare the size of global variables. This may not be portable, however."
891 #: build/C/man3/cmsg.3:161 build/C/man3/endian.3:107 build/C/man5/gai.conf.5:74 build/C/man3/getaddrinfo.3:623 build/C/man3/getaddrinfo_a.3:314 build/C/man3/getnameinfo.3:243 build/C/man3/getprotoent_r.3:135 build/C/man3/getservent_r.3:134 build/C/man5/hosts.5:107 build/C/man3/inet.3:262 build/C/man3/inet_net_pton.3:247 build/C/man3/inet_ntop.3:115 build/C/man3/inet_pton.3:156 build/C/man5/nss.5:100 build/C/man7/unix.7:608
897 #: build/C/man3/cmsg.3:165
898 msgid "This code looks for the B<IP_TTL> option in a received ancillary buffer:"
902 #: build/C/man3/cmsg.3:172
905 "struct msghdr msgh;\n"
906 "struct cmsghdr *cmsg;\n"
908 "int received_ttl;\n"
912 #: build/C/man3/cmsg.3:189
915 "/* Receive auxiliary data in msgh */\n"
916 "for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;\n"
917 " cmsg = CMSG_NXTHDR(&msgh,cmsg)) {\n"
918 " if (cmsg-E<gt>cmsg_level == IPPROTO_IP\n"
919 " && cmsg-E<gt>cmsg_type == IP_TTL) {\n"
920 " ttlptr = (int *) CMSG_DATA(cmsg);\n"
921 " received_ttl = *ttlptr;\n"
925 "if (cmsg == NULL) {\n"
927 " * Error: IP_TTL not enabled or small buffer\n"
934 #: build/C/man3/cmsg.3:195
936 "The code below passes an array of file descriptors over a UNIX domain socket "
937 "using B<SCM_RIGHTS>:"
941 #: build/C/man3/cmsg.3:208
944 "struct msghdr msg = {0};\n"
945 "struct cmsghdr *cmsg;\n"
946 "int myfds[NUM_FD]; /* Contains the file descriptors to pass. */\n"
948 " /* ancillary data buffer, wrapped in a union in order to ensure it is\n"
949 " suitably aligned */\n"
950 " char buf[CMSG_SPACE(sizeof myfds)];\n"
951 " struct cmsghdr align;\n"
957 #: build/C/man3/cmsg.3:220
960 "msg.msg_control = u.buf;\n"
961 "msg.msg_controllen = sizeof u.buf;\n"
962 "cmsg = CMSG_FIRSTHDR(&msg);\n"
963 "cmsg-E<gt>cmsg_level = SOL_SOCKET;\n"
964 "cmsg-E<gt>cmsg_type = SCM_RIGHTS;\n"
965 "cmsg-E<gt>cmsg_len = CMSG_LEN(sizeof(int) * NUM_FD);\n"
966 "/* Initialize the payload: */\n"
967 "fdptr = (int *) CMSG_DATA(cmsg);\n"
968 "memcpy(fdptr, myfds, NUM_FD * sizeof(int));\n"
969 "/* Sum of the length of all control messages in the buffer: */\n"
970 "msg.msg_controllen = cmsg-E<gt>cmsg_len;\n"
974 #: build/C/man3/cmsg.3:225
975 msgid "B<recvmsg>(2), B<sendmsg>(2)"
979 #: build/C/man3/cmsg.3:226
984 #: build/C/man7/ddp.7:12
990 #: build/C/man7/ddp.7:12
996 #: build/C/man7/ddp.7:15
997 msgid "ddp - Linux AppleTalk protocol implementation"
1001 #: build/C/man7/ddp.7:19
1002 msgid "B<#include E<lt>netatalk/at.hE<gt>>"
1006 #: build/C/man7/ddp.7:21
1007 msgid "I<ddp_socket>B< = socket(AF_APPLETALK, SOCK_DGRAM, 0);>"
1011 #: build/C/man7/ddp.7:23
1012 msgid "I<raw_socket>B< = socket(AF_APPLETALK, SOCK_RAW, >I<protocol>B<);>"
1016 #: build/C/man7/ddp.7:34
1018 "Linux implements the AppleTalk protocols described in I<Inside AppleTalk>. "
1019 "Only the DDP layer and AARP are present in the kernel. They are designed to "
1020 "be used via the B<netatalk> protocol libraries. This page documents the "
1021 "interface for those who wish or need to use the DDP layer directly."
1025 #: build/C/man7/ddp.7:39
1027 "The communication between AppleTalk and the user program works using a "
1028 "BSD-compatible socket interface. For more information on sockets, see "
1033 #: build/C/man7/ddp.7:60
1035 "An AppleTalk socket is created by calling the B<socket>(2) function with a "
1036 "B<AF_APPLETALK> socket family argument. Valid socket types are "
1037 "B<SOCK_DGRAM> to open a B<ddp> socket or B<SOCK_RAW> to open a B<raw> "
1038 "socket. I<protocol> is the AppleTalk protocol to be received or sent. For "
1039 "B<SOCK_RAW> you must specify B<ATPROTO_DDP>."
1043 #: build/C/man7/ddp.7:65
1045 "Raw sockets may be opened only by a process with effective user ID 0 or when "
1046 "the process has the B<CAP_NET_RAW> capability."
1050 #: build/C/man7/ddp.7:65 build/C/man7/ip.7:123 build/C/man7/ipv6.7:142 build/C/man7/raw.7:93 build/C/man7/udp.7:98 build/C/man7/udplite.7:58 build/C/man7/unix.7:57
1052 msgid "Address format"
1056 #: build/C/man7/ddp.7:68
1058 "An AppleTalk socket address is defined as a combination of a network number, "
1059 "a node number, and a port number."
1063 #: build/C/man7/ddp.7:75
1066 "struct at_addr {\n"
1067 " unsigned short s_net;\n"
1068 " unsigned char s_node;\n"
1073 #: build/C/man7/ddp.7:81
1076 "struct sockaddr_atalk {\n"
1077 " sa_family_t sat_family; /* address family */\n"
1078 " unsigned char sat_port; /* port */\n"
1079 " struct at_addr sat_addr; /* net/node */\n"
1083 #. FIXME . this doesn't make sense [johnl]
1085 #: build/C/man7/ddp.7:120
1087 "I<sat_family> is always set to B<AF_APPLETALK>. I<sat_port> contains the "
1088 "port. The port numbers below 129 are known as I<reserved ports>. Only "
1089 "processes with the effective user ID 0 or the B<CAP_NET_BIND_SERVICE> "
1090 "capability may B<bind>(2) to these sockets. I<sat_addr> is the host "
1091 "address. The I<net> member of I<struct at_addr> contains the host network "
1092 "in network byte order. The value of B<AT_ANYNET> is a wildcard and also "
1093 "implies \\(lqthis network.\\(rq The I<node> member of I<struct at_addr> "
1094 "contains the host node number. The value of B<AT_ANYNODE> is a wildcard and "
1095 "also implies \\(lqthis node.\\(rq The value of B<ATADDR_BCAST> is a link "
1096 "local broadcast address."
1100 #: build/C/man7/ddp.7:120 build/C/man7/ip.7:224 build/C/man7/ipv6.7:192 build/C/man7/packet.7:180 build/C/man7/raw.7:109 build/C/man7/tcp.7:889 build/C/man7/udp.7:178 build/C/man7/udplite.7:67 build/C/man7/unix.7:220 build/C/man7/x25.7:72
1102 msgid "Socket options"
1106 #: build/C/man7/ddp.7:122
1107 msgid "No protocol-specific socket options are supported."
1111 #: build/C/man7/ddp.7:128
1113 "IP supports a set of I</proc> interfaces to configure some global AppleTalk "
1114 "parameters. The parameters can be accessed by reading or writing files in "
1115 "the directory I</proc/sys/net/atalk/>."
1119 #: build/C/man7/ddp.7:128
1121 msgid "I<aarp-expiry-time>"
1125 #: build/C/man7/ddp.7:131
1126 msgid "The time interval (in seconds) before an AARP cache entry expires."
1130 #: build/C/man7/ddp.7:131
1132 msgid "I<aarp-resolve-time>"
1136 #: build/C/man7/ddp.7:134
1137 msgid "The time interval (in seconds) before an AARP cache entry is resolved."
1141 #: build/C/man7/ddp.7:134
1143 msgid "I<aarp-retransmit-limit>"
1147 #: build/C/man7/ddp.7:138
1149 "The number of retransmissions of an AARP query before the node is declared "
1154 #: build/C/man7/ddp.7:138
1156 msgid "I<aarp-tick-time>"
1160 #: build/C/man7/ddp.7:141
1161 msgid "The timer rate (in seconds) for the timer driving AARP."
1165 #: build/C/man7/ddp.7:144
1167 "The default values match the specification and should never need to be "
1171 #. FIXME . Add a section about multicasting
1173 #: build/C/man7/ddp.7:149
1174 msgid "All ioctls described in B<socket>(7) apply to DDP."
1178 #: build/C/man7/ddp.7:149 build/C/man3/gethostbyname.3:292 build/C/man3/getnetent_r.3:129 build/C/man2/getpeername.2:73 build/C/man3/getprotoent_r.3:119 build/C/man3/getservent_r.3:118 build/C/man3/inet_net_pton.3:145 build/C/man3/inet_ntop.3:91 build/C/man7/ip.7:1092 build/C/man7/ipv6.7:351 build/C/man7/packet.7:496 build/C/man7/raw.7:144 build/C/man2/shutdown.2:74 build/C/man7/tcp.7:1226 build/C/man7/udp.7:241 build/C/man7/udplite.7:121 build/C/man7/unix.7:405
1184 #: build/C/man7/ddp.7:153 build/C/man7/ip.7:1096 build/C/man7/raw.7:145
1190 #: build/C/man7/ddp.7:160
1192 "The user tried to execute an operation without the necessary permissions. "
1193 "These include sending to a broadcast address without having the broadcast "
1194 "flag set, and trying to bind to a reserved port without effective user ID 0 "
1195 "or B<CAP_NET_BIND_SERVICE>."
1199 #: build/C/man7/ddp.7:160 build/C/man7/ip.7:1112 build/C/man7/unix.7:406
1201 msgid "B<EADDRINUSE>"
1205 #: build/C/man7/ddp.7:163 build/C/man7/ip.7:1115
1206 msgid "Tried to bind to an address already in use."
1210 #: build/C/man7/ddp.7:163 build/C/man7/ip.7:1115 build/C/man7/packet.7:497
1212 msgid "B<EADDRNOTAVAIL>"
1216 #: build/C/man7/ddp.7:167 build/C/man7/ip.7:1119
1218 "A nonexistent interface was requested or the requested source address was "
1223 #: build/C/man7/ddp.7:167 build/C/man7/ip.7:1119
1229 #: build/C/man7/ddp.7:170 build/C/man7/ip.7:1122
1230 msgid "Operation on a nonblocking socket would block."
1234 #: build/C/man7/ddp.7:170 build/C/man7/ip.7:1122
1240 #: build/C/man7/ddp.7:173
1241 msgid "A connection operation on a nonblocking socket is already in progress."
1245 #: build/C/man7/ddp.7:173 build/C/man7/ip.7:1125
1247 msgid "B<ECONNABORTED>"
1251 #: build/C/man7/ddp.7:177 build/C/man7/ip.7:1129
1252 msgid "A connection was closed during an B<accept>(2)."
1256 #: build/C/man7/ddp.7:177 build/C/man7/ip.7:1129
1258 msgid "B<EHOSTUNREACH>"
1262 #: build/C/man7/ddp.7:180
1263 msgid "No routing table entry matches the destination address."
1267 #: build/C/man7/ddp.7:180 build/C/man2/getpeername.2:85 build/C/man7/ip.7:1134 build/C/man7/packet.7:503 build/C/man7/raw.7:152 build/C/man2/shutdown.2:79 build/C/man7/unix.7:422
1273 #: build/C/man7/ddp.7:183
1274 msgid "Invalid argument passed."
1278 #: build/C/man7/ddp.7:183 build/C/man7/ip.7:1140 build/C/man7/unix.7:431
1284 #: build/C/man7/ddp.7:187 build/C/man7/ip.7:1144
1285 msgid "B<connect>(2) was called on an already connected socket."
1289 #: build/C/man7/ddp.7:187 build/C/man3/inet_net_pton.3:151 build/C/man7/ip.7:1144 build/C/man7/packet.7:506 build/C/man7/raw.7:155
1295 #: build/C/man7/ddp.7:190
1296 msgid "Datagram is bigger than the DDP MTU."
1300 #: build/C/man7/ddp.7:190 build/C/man7/ipv6.7:352 build/C/man7/packet.7:515
1306 #: build/C/man7/ddp.7:193
1307 msgid "Network device not available or not capable of sending IP."
1311 #: build/C/man7/ddp.7:193 build/C/man3/getnetent_r.3:130 build/C/man3/getprotoent_r.3:120 build/C/man3/getservent_r.3:119 build/C/man3/inet_net_pton.3:154 build/C/man7/ip.7:1152 build/C/man7/packet.7:518 build/C/man7/unix.7:436
1317 #: build/C/man7/ddp.7:197 build/C/man7/ip.7:1156
1318 msgid "B<SIOCGSTAMP> was called on a socket where no packet arrived."
1322 #: build/C/man7/ddp.7:197
1324 msgid "B<ENOMEM> and B<ENOBUFS>"
1328 #: build/C/man7/ddp.7:200
1329 msgid "Not enough memory available."
1333 #: build/C/man7/ddp.7:200 build/C/man7/ip.7:1156
1339 #: build/C/man7/ddp.7:203 build/C/man7/ip.7:1159
1340 msgid "A kernel subsystem was not configured."
1344 #: build/C/man7/ddp.7:203 build/C/man7/ip.7:1159
1346 msgid "B<ENOPROTOOPT> and B<EOPNOTSUPP>"
1350 #: build/C/man7/ddp.7:206 build/C/man7/ip.7:1162
1351 msgid "Invalid socket option passed."
1355 #: build/C/man7/ddp.7:206 build/C/man2/getpeername.2:93 build/C/man7/ip.7:1162 build/C/man7/packet.7:521 build/C/man2/shutdown.2:84 build/C/man7/unix.7:444
1361 #: build/C/man7/ddp.7:210 build/C/man7/ip.7:1166
1363 "The operation is defined only on a connected socket, but the socket wasn't "
1368 #: build/C/man7/ddp.7:210 build/C/man7/ip.7:1166 build/C/man7/packet.7:527 build/C/man7/raw.7:166 build/C/man7/unix.7:451
1374 #: build/C/man7/ddp.7:215
1376 "User doesn't have permission to set high priority, make a configuration "
1377 "change, or send signals to the requested process or group."
1381 #: build/C/man7/ddp.7:215 build/C/man7/ip.7:1170 build/C/man7/tcp.7:1233 build/C/man7/unix.7:455
1387 #: build/C/man7/ddp.7:218 build/C/man7/ip.7:1173
1388 msgid "The connection was unexpectedly closed or shut down by the other end."
1392 #: build/C/man7/ddp.7:218 build/C/man7/ip.7:1173 build/C/man7/unix.7:477
1394 msgid "B<ESOCKTNOSUPPORT>"
1398 #: build/C/man7/ddp.7:221
1399 msgid "The socket was unconfigured, or an unknown socket type was requested."
1403 #: build/C/man7/ddp.7:226
1405 "AppleTalk is supported by Linux 2.0 or higher. The I</proc> interfaces "
1406 "exist since Linux 2.2."
1410 #: build/C/man7/ddp.7:232
1412 "Be very careful with the B<SO_BROADCAST> option - it is not privileged in "
1413 "Linux. It is easy to overload the network with careless sending to "
1414 "broadcast addresses."
1418 #: build/C/man7/ddp.7:232 build/C/man7/ip.7:1232 build/C/man7/packet.7:569
1420 msgid "Compatibility"
1424 #: build/C/man7/ddp.7:239
1426 "The basic AppleTalk socket interface is compatible with B<netatalk> on "
1427 "BSD-derived systems. Many BSD systems fail to check B<SO_BROADCAST> when "
1428 "sending broadcast frames; this can lead to compatibility problems."
1432 #: build/C/man7/ddp.7:244
1434 "The raw socket mode is unique to Linux and exists to support the alternative "
1435 "CAP package and AppleTalk monitoring tools more easily."
1439 #: build/C/man7/ddp.7:246 build/C/man7/ip.7:1247
1440 msgid "There are too many inconsistent error values."
1444 #: build/C/man7/ddp.7:249
1446 "The ioctls used to configure routing tables, devices, AARP tables and other "
1447 "devices are not yet described."
1451 #: build/C/man7/ddp.7:253
1452 msgid "B<recvmsg>(2), B<sendmsg>(2), B<capabilities>(7), B<socket>(7)"
1456 #: build/C/man3/endian.3:28
1462 #: build/C/man3/endian.3:28 build/C/man3/getnetent_r.3:26 build/C/man3/getprotoent_r.3:26 build/C/man3/getservent_r.3:26
1468 #: build/C/man3/endian.3:33
1470 "htobe16, htole16, be16toh, le16toh, htobe32, htole32, be32toh, le32toh, "
1471 "htobe64, htole64, be64toh, le64toh - convert values between host and "
1472 "big-/little-endian byte order"
1476 #: build/C/man3/endian.3:37
1479 "B<#define _BSD_SOURCE> /* See feature_test_macros(7) */\n"
1480 "B<#include E<lt>endian.hE<gt>>\n"
1484 #: build/C/man3/endian.3:42
1487 "B<uint16_t htobe16(uint16_t >I<host_16bits>B<);>\n"
1488 "B<uint16_t htole16(uint16_t >I<host_16bits>B<);>\n"
1489 "B<uint16_t be16toh(uint16_t >I<big_endian_16bits>B<);>\n"
1490 "B<uint16_t le16toh(uint16_t >I<little_endian_16bits>B<);>\n"
1494 #: build/C/man3/endian.3:47
1497 "B<uint32_t htobe32(uint32_t >I<host_32bits>B<);>\n"
1498 "B<uint32_t htole32(uint32_t >I<host_32bits>B<);>\n"
1499 "B<uint32_t be32toh(uint32_t >I<big_endian_32bits>B<);>\n"
1500 "B<uint32_t le32toh(uint32_t >I<little_endian_32bits>B<);>\n"
1504 #: build/C/man3/endian.3:52
1507 "B<uint64_t htobe64(uint64_t >I<host_64bits>B<);>\n"
1508 "B<uint64_t htole64(uint64_t >I<host_64bits>B<);>\n"
1509 "B<uint64_t be64toh(uint64_t >I<big_endian_64bits>B<);>\n"
1510 "B<uint64_t le64toh(uint64_t >I<little_endian_64bits>B<);>\n"
1514 #: build/C/man3/endian.3:57
1516 "These functions convert the byte encoding of integer values from the byte "
1517 "order that the current CPU (the \"host\") uses, to and from little-endian "
1518 "and big-endian byte order."
1522 #: build/C/man3/endian.3:62
1524 "The number, I<nn>, in the name of each function indicates the size of "
1525 "integer handled by the function, either 16, 32, or 64 bits."
1529 #: build/C/man3/endian.3:65
1531 "The functions with names of the form \"htobeI<nn>\" convert from host byte "
1532 "order to big-endian order."
1536 #: build/C/man3/endian.3:68
1538 "The functions with names of the form \"htoleI<nn>\" convert from host byte "
1539 "order to little-endian order."
1543 #: build/C/man3/endian.3:71
1545 "The functions with names of the form \"beI<nn>toh\" convert from big-endian "
1546 "order to host byte order."
1550 #: build/C/man3/endian.3:74
1552 "The functions with names of the form \"leI<nn>toh\" convert from "
1553 "little-endian order to host byte order."
1557 #: build/C/man3/endian.3:76
1558 msgid "These functions were added to glibc in version 2.9."
1562 #: build/C/man3/endian.3:91
1564 "These functions are nonstandard. Similar functions are present on the BSDs, "
1565 "where the required header file is I<E<lt>sys/endian.hE<gt>> instead of "
1566 "I<E<lt>endian.hE<gt>>. Unfortunately, NetBSD, FreeBSD, and glibc haven't "
1567 "followed the original OpenBSD naming convention for these functions, whereby "
1568 "the I<nn> component always appears at the end of the function name (thus, "
1569 "for example, in NetBSD, FreeBSD, and glibc, the equivalent of OpenBSDs "
1570 "\"betoh32\" is \"be32toh\")."
1574 #: build/C/man3/endian.3:99
1576 "These functions are similar to the older B<byteorder>(3) family of "
1577 "functions. For example, B<be32toh>() is identical to B<ntohl>()."
1581 #: build/C/man3/endian.3:107
1583 "The advantage of the B<byteorder>(3) functions is that they are standard "
1584 "functions available on all UNIX systems. On the other hand, the fact that "
1585 "they were designed for use in the context of TCP/IP means that they lack the "
1586 "64-bit and little-endian variants described in this page."
1590 #: build/C/man3/endian.3:114
1592 "The program below display the results of converting an integer from host "
1593 "byte order to both little-endian and big-endian byte order. Since host byte "
1594 "order is either little-endian or big-endian, only one of these conversions "
1595 "will have an effect. When we run this program on a little-endian system "
1596 "such as x86-32, we see the following:"
1600 #: build/C/man3/endian.3:121
1604 "x.u32 = 0x44332211\n"
1605 "htole32(x.u32) = 0x44332211\n"
1606 "htobe32(x.u32) = 0x11223344\n"
1610 #: build/C/man3/endian.3:123 build/C/man3/getprotoent_r.3:162 build/C/man3/getservent_r.3:160 build/C/man3/inet.3:278 build/C/man3/inet_net_pton.3:331 build/C/man3/inet_pton.3:173
1612 msgid "Program source"
1616 #: build/C/man3/endian.3:130
1619 "#include E<lt>endian.hE<gt>\n"
1620 "#include E<lt>stdint.hE<gt>\n"
1621 "#include E<lt>stdio.hE<gt>\n"
1622 "#include E<lt>stdlib.hE<gt>\n"
1626 #: build/C/man3/endian.3:138
1630 "main(int argc, char *argv[])\n"
1634 " uint8_t arr[4];\n"
1639 #: build/C/man3/endian.3:143
1642 " x.arr[0] = 0x11;\t/* Lowest-address byte */\n"
1643 " x.arr[1] = 0x22;\n"
1644 " x.arr[2] = 0x33;\n"
1645 " x.arr[3] = 0x44;\t/* Highest-address byte */\n"
1649 #: build/C/man3/endian.3:147
1652 " printf(\"x.u32 = 0x%x\\en\", x.u32);\n"
1653 " printf(\"htole32(x.u32) = 0x%x\\en\", htole32(x.u32));\n"
1654 " printf(\"htobe32(x.u32) = 0x%x\\en\", htobe32(x.u32));\n"
1658 #: build/C/man3/endian.3:150 build/C/man3/getaddrinfo.3:827 build/C/man3/getprotoent_r.3:236 build/C/man3/getservent_r.3:240 build/C/man3/inet_net_pton.3:389 build/C/man3/inet_pton.3:214
1661 " exit(EXIT_SUCCESS);\n"
1666 #: build/C/man3/endian.3:152
1667 msgid "B<byteorder>(3)"
1671 #: build/C/man3/ether_aton.3:31
1677 #: build/C/man3/ether_aton.3:31 build/C/man7/udplite.7:27
1683 #: build/C/man3/ether_aton.3:35
1685 "ether_aton, ether_ntoa, ether_ntohost, ether_hostton, ether_line, "
1686 "ether_ntoa_r, ether_aton_r - Ethernet address manipulation routines"
1690 #: build/C/man3/ether_aton.3:38
1692 msgid "B<#include E<lt>netinet/ether.hE<gt>>\n"
1696 #: build/C/man3/ether_aton.3:40
1698 msgid "B<char *ether_ntoa(const struct ether_addr *>I<addr>B<);>\n"
1702 #: build/C/man3/ether_aton.3:42
1704 msgid "B<struct ether_addr *ether_aton(const char *>I<asc>B<);>\n"
1708 #: build/C/man3/ether_aton.3:44
1711 "B<int ether_ntohost(char *>I<hostname>B<, const struct ether_addr "
1716 #: build/C/man3/ether_aton.3:46
1719 "B<int ether_hostton(const char *>I<hostname>B<, struct ether_addr "
1724 #: build/C/man3/ether_aton.3:49
1727 "B<int ether_line(const char *>I<line>B<, struct ether_addr *>I<addr>B<,>\n"
1728 "B< char *>I<hostname>B<);>\n"
1732 #: build/C/man3/ether_aton.3:51 build/C/man3/gethostbyname.3:70
1734 msgid "/* GNU extensions */\n"
1738 #: build/C/man3/ether_aton.3:53
1741 "B<char *ether_ntoa_r(const struct ether_addr *>I<addr>B<, char "
1746 #: build/C/man3/ether_aton.3:56
1749 "B<struct ether_addr *ether_aton_r(const char *>I<asc>B<,>\n"
1750 "B< struct ether_addr *>I<addr>B<);>\n"
1754 #: build/C/man3/ether_aton.3:67
1756 "B<ether_aton>() converts the 48-bit Ethernet host address I<asc> from the "
1757 "standard hex-digits-and-colons notation into binary data in network byte "
1758 "order and returns a pointer to it in a statically allocated buffer, which "
1759 "subsequent calls will overwrite. B<ether_aton>() returns NULL if the "
1760 "address is invalid."
1764 #: build/C/man3/ether_aton.3:76
1766 "The B<ether_ntoa>() function converts the Ethernet host address I<addr> "
1767 "given in network byte order to a string in standard hex-digits-and-colons "
1768 "notation, omitting leading zeros. The string is returned in a statically "
1769 "allocated buffer, which subsequent calls will overwrite."
1773 #: build/C/man3/ether_aton.3:83
1775 "The B<ether_ntohost>() function maps an Ethernet address to the "
1776 "corresponding hostname in I</etc/ethers> and returns nonzero if it cannot be "
1781 #: build/C/man3/ether_aton.3:90
1783 "The B<ether_hostton>() function maps a hostname to the corresponding "
1784 "Ethernet address in I</etc/ethers> and returns nonzero if it cannot be "
1789 #: build/C/man3/ether_aton.3:102
1791 "The B<ether_line>() function parses a line in I</etc/ethers> format "
1792 "(ethernet address followed by whitespace followed by hostname; \\(aq#\\(aq "
1793 "introduces a comment) and returns an address and hostname pair, or nonzero "
1794 "if it cannot be parsed. The buffer pointed to by I<hostname> must be "
1795 "sufficiently long, for example, have the same length as I<line>."
1799 #: build/C/man3/ether_aton.3:113
1801 "The functions B<ether_ntoa_r>() and B<ether_aton_r>() are reentrant "
1802 "thread-safe versions of B<ether_ntoa>() and B<ether_aton>() respectively, "
1803 "and do not use static buffers."
1807 #: build/C/man3/ether_aton.3:119
1808 msgid "The structure I<ether_addr> is defined in I<E<lt>net/ethernet.hE<gt>> as:"
1812 #: build/C/man3/ether_aton.3:125
1815 "struct ether_addr {\n"
1816 " uint8_t ether_addr_octet[6];\n"
1821 #: build/C/man3/ether_aton.3:130
1822 msgid "For an explanation of the terms used in this section, see B<attributes>(7)."
1826 #: build/C/man3/ether_aton.3:135
1828 msgid "Interface\tAttribute\tValue\n"
1832 #: build/C/man3/ether_aton.3:136 build/C/man3/ether_aton.3:140
1838 #: build/C/man3/ether_aton.3:137
1840 msgid "B<ether_aton>(),\n"
1844 #: build/C/man3/ether_aton.3:138
1846 msgid "B<ether_ntoa>()\n"
1850 #: build/C/man3/ether_aton.3:139
1852 msgid "T}\tThread safety\tMT-Unsafe\n"
1856 #: build/C/man3/ether_aton.3:141
1858 msgid "B<ether_ntohost>(),\n"
1862 #: build/C/man3/ether_aton.3:142
1864 msgid "B<ether_hostton>(),\n"
1868 #: build/C/man3/ether_aton.3:143
1870 msgid "B<ether_line>(),\n"
1874 #: build/C/man3/ether_aton.3:144
1876 msgid "B<ether_ntoa_r>(),\n"
1880 #: build/C/man3/ether_aton.3:145
1882 msgid "B<ether_aton_r>()\n"
1886 #: build/C/man3/ether_aton.3:146
1888 msgid "T}\tThread safety\tMT-Safe\n"
1892 #: build/C/man3/ether_aton.3:151
1893 msgid "4.3BSD, SunOS."
1896 #. The fix was presumably commit c0a0f9a32c8baa6ab93d00eb42d92c02e9e146d7
1897 #. which was in glibc 2.3
1899 #: build/C/man3/ether_aton.3:157
1901 "In glibc 2.2.5 and earlier, the implementation of B<ether_line>() is "
1906 #: build/C/man3/ether_aton.3:158
1907 msgid "B<ethers>(5)"
1911 #: build/C/man5/gai.conf.5:19
1917 #: build/C/man5/gai.conf.5:19 build/C/man5/nss.5:19
1923 #: build/C/man5/gai.conf.5:22
1924 msgid "gai.conf - getaddrinfo(3) configuration file"
1928 #: build/C/man5/gai.conf.5:36
1930 "A call to B<getaddrinfo>(3) might return multiple answers. According to "
1931 "RFC\\ 3484 these answers must be sorted so that the answer with the highest "
1932 "success rate is first in the list. The RFC provides an algorithm for the "
1933 "sorting. The static rules are not always adequate, though. For this "
1934 "reason, the RFC also requires that system administrators should have the "
1935 "possibility to dynamically change the sorting. For the glibc "
1936 "implementation, this can be achieved with the I</etc/gai.conf> file."
1940 #: build/C/man5/gai.conf.5:40
1942 "Each line in the configuration file consists of a keyword and its "
1943 "parameters. White spaces in any place are ignored. Lines starting with "
1944 "\\(aq#\\(aq are comments and are ignored."
1948 #: build/C/man5/gai.conf.5:42
1949 msgid "The keywords currently recognized are:"
1953 #: build/C/man5/gai.conf.5:42
1955 msgid "B<label> I<netmask> I<precedence>"
1959 #: build/C/man5/gai.conf.5:51
1961 "The value is added to the label table used in the RFC\\ 3484 sorting. If "
1962 "any B<label> definition is present in the configuration file is present, the "
1963 "default table is not used. All the label definitions of the default table "
1964 "which are to be maintained have to be duplicated. Following the keyword, "
1965 "the line has to contain a network mask and a label value."
1969 #: build/C/man5/gai.conf.5:51
1971 msgid "B<precedence> I<netmask> I<precedence>"
1975 #: build/C/man5/gai.conf.5:58
1977 "This keyword is similar to B<label>, but instead the value is added to the "
1978 "precedence table as specified in RFC\\ 3484. Once again, the presence of a "
1979 "single B<precedence> line in the configuration file causes the default table "
1984 #: build/C/man5/gai.conf.5:58
1986 msgid "B<reload> E<lt>B<yes>|B<no>E<gt>"
1990 #: build/C/man5/gai.conf.5:67
1992 "This keyword controls whether a process checks whether the configuration "
1993 "file has been changed since the last time it was read. If the value is "
1994 "\"B<yes>\", the file is reread. This might cause problems in multithreaded "
1995 "applications and is generally a bad idea. The default is \"B<no>\"."
1999 #: build/C/man5/gai.conf.5:67
2001 msgid "B<scopev4> I<mask> I<value>"
2005 #: build/C/man5/gai.conf.5:72
2007 "Add another rule to the RFC\\ 3484 scope table for IPv4 address. By "
2008 "default, the scope IDs described in section 3.2 in RFC\\ 3438 are used. "
2009 "Changing these defaults should hardly ever be necessary."
2013 #: build/C/man5/gai.conf.5:72 build/C/man3/getaddrinfo.3:593 build/C/man3/gethostbyname.3:307 build/C/man3/getnameinfo.3:197 build/C/man3/getnetent.3:141 build/C/man3/getprotoent.3:134 build/C/man3/getservent.3:153 build/C/man5/host.conf.5:180 build/C/man5/hosts.5:86 build/C/man5/hosts.equiv.5:69 build/C/man5/networks.5:70 build/C/man5/nss.5:98 build/C/man5/nsswitch.conf.5:298 build/C/man5/protocols.5:77 build/C/man5/resolv.conf.5:298 build/C/man3/resolver.3:267 build/C/man5/services.5:185 build/C/man3/setnetgrent.3:88 build/C/man7/udplite.7:126
2019 #: build/C/man5/gai.conf.5:74 build/C/man3/getaddrinfo.3:595
2020 msgid "I</etc/gai.conf>"
2024 #: build/C/man5/gai.conf.5:77
2026 "The default table according to RFC\\ 3484 would be specified with the "
2027 "following configuration file:"
2031 #: build/C/man5/gai.conf.5:89
2036 "label 2002::/16 2\n"
2038 "label ::ffff:0:0/96 4\n"
2039 "precedence ::1/128 50\n"
2040 "precedence ::/0 40\n"
2041 "precedence 2002::/16 30\n"
2042 "precedence ::/96 20\n"
2043 "precedence ::ffff:0:0/96 10\n"
2047 #: build/C/man5/gai.conf.5:95
2048 msgid "B<getaddrinfo>(3), RFC\\ 3484"
2052 #: build/C/man3/getaddrinfo.3:44
2058 #: build/C/man3/getaddrinfo.3:44
2064 #: build/C/man3/getaddrinfo.3:48
2066 "getaddrinfo, freeaddrinfo, gai_strerror - network address and service "
2071 #: build/C/man3/getaddrinfo.3:53 build/C/man3/getipnodebyname.3:35
2074 "B<#include E<lt>sys/types.hE<gt>>\n"
2075 "B<#include E<lt>sys/socket.hE<gt>>\n"
2076 "B<#include E<lt>netdb.hE<gt>>\n"
2080 #: build/C/man3/getaddrinfo.3:57
2083 "B<int getaddrinfo(const char *>I<node>B<, const char *>I<service>B<,>\n"
2084 "B< const struct addrinfo *>I<hints>B<,>\n"
2085 "B< struct addrinfo **>I<res>B<);>\n"
2089 #: build/C/man3/getaddrinfo.3:59
2091 msgid "B<void freeaddrinfo(struct addrinfo *>I<res>B<);>\n"
2095 #: build/C/man3/getaddrinfo.3:61
2097 msgid "B<const char *gai_strerror(int >I<errcode>B<);>\n"
2101 #: build/C/man3/getaddrinfo.3:66 build/C/man3/gethostbyname.3:93 build/C/man3/getnameinfo.3:26 build/C/man3/getnetent_r.3:52 build/C/man3/getprotoent_r.3:49 build/C/man3/getservent_r.3:49 build/C/man3/inet.3:70 build/C/man3/inet_net_pton.3:45 build/C/man3/rcmd.3:81 build/C/man3/setnetgrent.3:34
2102 msgid "Feature Test Macro Requirements for glibc (see B<feature_test_macros>(7)):"
2106 #: build/C/man3/getaddrinfo.3:72
2107 msgid "B<getaddrinfo>(), B<freeaddrinfo>(), B<gai_strerror>():"
2111 #: build/C/man3/getaddrinfo.3:74
2112 msgid "_POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || _POSIX_SOURCE"
2115 #. .BR getipnodebyname (3),
2116 #. .BR getipnodebyaddr (3),
2118 #: build/C/man3/getaddrinfo.3:101
2120 "Given I<node> and I<service>, which identify an Internet host and a service, "
2121 "B<getaddrinfo>() returns one or more I<addrinfo> structures, each of which "
2122 "contains an Internet address that can be specified in a call to B<bind>(2) "
2123 "or B<connect>(2). The B<getaddrinfo>() function combines the functionality "
2124 "provided by the B<gethostbyname>(3) and B<getservbyname>(3) functions into "
2125 "a single interface, but unlike the latter functions, B<getaddrinfo>() is "
2126 "reentrant and allows programs to eliminate IPv4-versus-IPv6 dependencies."
2130 #: build/C/man3/getaddrinfo.3:107
2132 "The I<addrinfo> structure used by B<getaddrinfo>() contains the following "
2137 #: build/C/man3/getaddrinfo.3:120
2140 "struct addrinfo {\n"
2143 " int ai_socktype;\n"
2144 " int ai_protocol;\n"
2145 " socklen_t ai_addrlen;\n"
2146 " struct sockaddr *ai_addr;\n"
2147 " char *ai_canonname;\n"
2148 " struct addrinfo *ai_next;\n"
2153 #: build/C/man3/getaddrinfo.3:142
2155 "The I<hints> argument points to an I<addrinfo> structure that specifies "
2156 "criteria for selecting the socket address structures returned in the list "
2157 "pointed to by I<res>. If I<hints> is not NULL it points to an I<addrinfo> "
2158 "structure whose I<ai_family>, I<ai_socktype>, and I<ai_protocol> specify "
2159 "criteria that limit the set of socket addresses returned by "
2160 "B<getaddrinfo>(), as follows:"
2164 #: build/C/man3/getaddrinfo.3:142
2166 msgid "I<ai_family>"
2170 #: build/C/man3/getaddrinfo.3:158
2172 "This field specifies the desired address family for the returned addresses. "
2173 "Valid values for this field include B<AF_INET> and B<AF_INET6>. The value "
2174 "B<AF_UNSPEC> indicates that B<getaddrinfo>() should return socket addresses "
2175 "for any address family (either IPv4 or IPv6, for example) that can be used "
2176 "with I<node> and I<service>."
2180 #: build/C/man3/getaddrinfo.3:158
2182 msgid "I<ai_socktype>"
2186 #: build/C/man3/getaddrinfo.3:167
2188 "This field specifies the preferred socket type, for example B<SOCK_STREAM> "
2189 "or B<SOCK_DGRAM>. Specifying 0 in this field indicates that socket "
2190 "addresses of any type can be returned by B<getaddrinfo>()."
2194 #: build/C/man3/getaddrinfo.3:167
2196 msgid "I<ai_protocol>"
2200 #: build/C/man3/getaddrinfo.3:173
2202 "This field specifies the protocol for the returned socket addresses. "
2203 "Specifying 0 in this field indicates that socket addresses with any protocol "
2204 "can be returned by B<getaddrinfo>()."
2208 #: build/C/man3/getaddrinfo.3:173
2214 #: build/C/man3/getaddrinfo.3:177
2216 "This field specifies additional options, described below. Multiple flags "
2217 "are specified by bitwise OR-ing them together."
2221 #: build/C/man3/getaddrinfo.3:181
2223 "All the other fields in the structure pointed to by I<hints> must contain "
2224 "either 0 or a null pointer, as appropriate."
2228 #: build/C/man3/getaddrinfo.3:216
2230 "Specifying I<hints> as NULL is equivalent to setting I<ai_socktype> and "
2231 "I<ai_protocol> to 0; I<ai_family> to B<AF_UNSPEC>; and I<ai_flags> to "
2232 "B<(AI_V4MAPPED\\ |\\ AI_ADDRCONFIG)>. (POSIX specifies different defaults "
2233 "for I<ai_flags>; see NOTES.) I<node> specifies either a numerical network "
2234 "address (for IPv4, numbers-and-dots notation as supported by "
2235 "B<inet_aton>(3); for IPv6, hexadecimal string format as supported by "
2236 "B<inet_pton>(3)), or a network hostname, whose network addresses are looked "
2237 "up and resolved. If I<hints.ai_flags> contains the B<AI_NUMERICHOST> flag, "
2238 "then I<node> must be a numerical network address. The B<AI_NUMERICHOST> "
2239 "flag suppresses any potentially lengthy network host address lookups."
2243 #: build/C/man3/getaddrinfo.3:241
2245 "If the B<AI_PASSIVE> flag is specified in I<hints.ai_flags>, and I<node> is "
2246 "NULL, then the returned socket addresses will be suitable for B<bind>(2)ing "
2247 "a socket that will B<accept>(2) connections. The returned socket address "
2248 "will contain the \"wildcard address\" (B<INADDR_ANY> for IPv4 addresses, "
2249 "B<IN6ADDR_ANY_INIT> for IPv6 address). The wildcard address is used by "
2250 "applications (typically servers) that intend to accept connections on any "
2251 "of the hosts's network addresses. If I<node> is not NULL, then the "
2252 "B<AI_PASSIVE> flag is ignored."
2256 #: build/C/man3/getaddrinfo.3:261
2258 "If the B<AI_PASSIVE> flag is not set in I<hints.ai_flags>, then the returned "
2259 "socket addresses will be suitable for use with B<connect>(2), B<sendto>(2), "
2260 "or B<sendmsg>(2). If I<node> is NULL, then the network address will be set "
2261 "to the loopback interface address (B<INADDR_LOOPBACK> for IPv4 addresses, "
2262 "B<IN6ADDR_LOOPBACK_INIT> for IPv6 address); this is used by applications "
2263 "that intend to communicate with peers running on the same host."
2267 #: build/C/man3/getaddrinfo.3:284
2269 "I<service> sets the port in each returned address structure. If this "
2270 "argument is a service name (see B<services>(5)), it is translated to the "
2271 "corresponding port number. This argument can also be specified as a decimal "
2272 "number, which is simply converted to binary. If I<service> is NULL, then "
2273 "the port number of the returned socket addresses will be left "
2274 "uninitialized. If B<AI_NUMERICSERV> is specified in I<hints.ai_flags> and "
2275 "I<service> is not NULL, then I<service> must point to a string containing a "
2276 "numeric port number. This flag is used to inhibit the invocation of a name "
2277 "resolution service in cases where it is known not to be required."
2281 #: build/C/man3/getaddrinfo.3:290
2282 msgid "Either I<node> or I<service>, but not both, may be NULL."
2286 #: build/C/man3/getaddrinfo.3:306
2288 "The B<getaddrinfo>() function allocates and initializes a linked list of "
2289 "I<addrinfo> structures, one for each network address that matches I<node> "
2290 "and I<service>, subject to any restrictions imposed by I<hints>, and returns "
2291 "a pointer to the start of the list in I<res>. The items in the linked list "
2292 "are linked by the I<ai_next> field."
2296 #: build/C/man3/getaddrinfo.3:328
2298 "There are several reasons why the linked list may have more than one "
2299 "I<addrinfo> structure, including: the network host is multihomed, accessible "
2300 "over multiple protocols (e.g., both B<AF_INET> and B<AF_INET6>); or the same "
2301 "service is available from multiple socket types (one B<SOCK_STREAM> address "
2302 "and another B<SOCK_DGRAM> address, for example). Normally, the application "
2303 "should try using the addresses in the order in which they are returned. The "
2304 "sorting function used within B<getaddrinfo>() is defined in RFC\\ 3484; the "
2305 "order can be tweaked for a particular system by editing I</etc/gai.conf> "
2306 "(available since glibc 2.5)."
2309 #. In glibc prior to 2.3.4, the ai_canonname of each addrinfo
2310 #. structure was set pointing to the canonical name; that was
2311 #. more than POSIX.1-2001 specified, or other implementations provided.
2314 #: build/C/man3/getaddrinfo.3:343
2316 "If I<hints.ai_flags> includes the B<AI_CANONNAME> flag, then the "
2317 "I<ai_canonname> field of the first of the I<addrinfo> structures in the "
2318 "returned list is set to point to the official name of the host."
2322 #: build/C/man3/getaddrinfo.3:347
2324 "The remaining fields of each returned I<addrinfo> structure are initialized "
2329 #: build/C/man3/getaddrinfo.3:347 build/C/man3/getaddrinfo.3:370 build/C/man3/getaddrinfo_a.3:191 build/C/man3/getaddrinfo_a.3:195 build/C/man3/getaddrinfo_a.3:197 build/C/man3/inet_net_pton.3:207 build/C/man3/inet_net_pton.3:213 build/C/man3/inet_net_pton.3:220 build/C/man3/inet_net_pton.3:227 build/C/man3/inet_net_pton.3:234 build/C/man7/ip.7:1001 build/C/man7/ip.7:1004 build/C/man7/ip.7:1007 build/C/man7/ip.7:1010 build/C/man5/nsswitch.conf.5:144 build/C/man5/nsswitch.conf.5:148 build/C/man7/unix.7:95 build/C/man7/unix.7:120 build/C/man7/unix.7:136 build/C/man7/unix.7:162 build/C/man7/unix.7:166 build/C/man7/unix.7:170
2335 #: build/C/man3/getaddrinfo.3:370
2337 "The I<ai_family>, I<ai_socktype>, and I<ai_protocol> fields return the "
2338 "socket creation parameters (i.e., these fields have the same meaning as the "
2339 "corresponding arguments of B<socket>(2)). For example, I<ai_family> might "
2340 "return B<AF_INET> or B<AF_INET6>; I<ai_socktype> might return B<SOCK_DGRAM> "
2341 "or B<SOCK_STREAM>; and I<ai_protocol> returns the protocol for the socket."
2345 #: build/C/man3/getaddrinfo.3:377
2347 "A pointer to the socket address is placed in the I<ai_addr> field, and the "
2348 "length of the socket address, in bytes, is placed in the I<ai_addrlen> "
2353 #: build/C/man3/getaddrinfo.3:396
2355 "If I<hints.ai_flags> includes the B<AI_ADDRCONFIG> flag, then IPv4 addresses "
2356 "are returned in the list pointed to by I<res> only if the local system has "
2357 "at least one IPv4 address configured, and IPv6 addresses are returned only "
2358 "if the local system has at least one IPv6 address configured. The loopback "
2359 "address is not considered for this case as valid as a configured address. "
2360 "This flag is useful on, for example, IPv4-only systems, to ensure that "
2361 "B<getaddrinfo>() does not return IPv6 socket addresses that would always "
2362 "fail in B<connect>(2) or B<bind>(2)."
2366 #: build/C/man3/getaddrinfo.3:421
2368 "If I<hints.ai_flags> specifies the B<AI_V4MAPPED> flag, and "
2369 "I<hints.ai_family> was specified as B<AF_INET6>, and no matching IPv6 "
2370 "addresses could be found, then return IPv4-mapped IPv6 addresses in the list "
2371 "pointed to by I<res>. If both B<AI_V4MAPPED> and B<AI_ALL> are specified in "
2372 "I<hints.ai_flags>, then return both IPv6 and IPv4-mapped IPv6 addresses in "
2373 "the list pointed to by I<res>. B<AI_ALL> is ignored if B<AI_V4MAPPED> is "
2374 "not also specified."
2378 #: build/C/man3/getaddrinfo.3:427
2380 "The B<freeaddrinfo>() function frees the memory that was allocated for the "
2381 "dynamically allocated linked list I<res>."
2385 #: build/C/man3/getaddrinfo.3:427
2387 msgid "Extensions to getaddrinfo() for Internationalized Domain Names"
2391 #: build/C/man3/getaddrinfo.3:436
2393 "Starting with glibc 2.3.4, B<getaddrinfo>() has been extended to "
2394 "selectively allow the incoming and outgoing hostnames to be transparently "
2395 "converted to and from the Internationalized Domain Name (IDN) format (see "
2396 "RFC 3490, I<Internationalizing Domain Names in Applications (IDNA)>). Four "
2397 "new flags are defined:"
2401 #: build/C/man3/getaddrinfo.3:436
2407 #: build/C/man3/getaddrinfo.3:442
2409 "If this flag is specified, then the node name given in I<node> is converted "
2410 "to IDN format if necessary. The source encoding is that of the current "
2414 #. Implementation Detail:
2415 #. To minimize effects on system performance the implementation might
2416 #. want to check whether the input string contains any non-ASCII
2417 #. characters. If there are none the IDN step can be skipped completely.
2418 #. On systems which allow not-ASCII safe encodings for a locale this
2419 #. might be a problem.
2421 #: build/C/man3/getaddrinfo.3:454
2423 "If the input name contains non-ASCII characters, then the IDN encoding is "
2424 "used. Those parts of the node name (delimited by dots) that contain "
2425 "non-ASCII characters are encoded using ASCII Compatible Encoding (ACE) "
2426 "before being passed to the name resolution functions."
2430 #: build/C/man3/getaddrinfo.3:454
2432 msgid "B<AI_CANONIDN>"
2436 #: build/C/man3/getaddrinfo.3:466
2438 "After a successful name lookup, and if the B<AI_CANONNAME> flag was "
2439 "specified, B<getaddrinfo>() will return the canonical name of the node "
2440 "corresponding to the I<addrinfo> structure value passed back. The return "
2441 "value is an exact copy of the value returned by the name resolution "
2446 #. Implementation Detail:
2447 #. If no component of the returned name starts with xn\-\- the IDN
2448 #. step can be skipped, therefore avoiding unnecessary slowdowns.
2450 #: build/C/man3/getaddrinfo.3:479
2452 "If the name is encoded using ACE, then it will contain the I<xn--> prefix "
2453 "for one or more components of the name. To convert these components into a "
2454 "readable form the B<AI_CANONIDN> flag can be passed in addition to "
2455 "B<AI_CANONNAME>. The resulting string is encoded using the current locale's "
2460 #: build/C/man3/getaddrinfo.3:479
2462 msgid "B<AI_IDN_ALLOW_UNASSIGNED>, B<AI_IDN_USE_STD3_ASCII_RULES>"
2466 #: build/C/man3/getaddrinfo.3:486 build/C/man3/getnameinfo.3:139
2468 "Setting these flags will enable the IDNA_ALLOW_UNASSIGNED (allow unassigned "
2469 "Unicode code points) and IDNA_USE_STD3_ASCII_RULES (check output to make "
2470 "sure it is a STD3 conforming hostname) flags respectively to be used in the "
2475 #: build/C/man3/getaddrinfo.3:486 build/C/man3/getaddrinfo_a.3:242 build/C/man3/gethostbyname.3:280 build/C/man3/getipnodebyname.3:186 build/C/man3/getnameinfo.3:139 build/C/man3/getnetent.3:130 build/C/man3/getnetent_r.3:118 build/C/man2/getpeername.2:68 build/C/man3/getprotoent.3:123 build/C/man3/getprotoent_r.3:108 build/C/man3/getservent.3:142 build/C/man3/getservent_r.3:107 build/C/man3/inet_net_pton.3:130 build/C/man3/inet_ntop.3:83 build/C/man3/inet_pton.3:116 build/C/man3/rcmd.3:239 build/C/man3/resolver.3:245 build/C/man3/setnetgrent.3:86 build/C/man2/shutdown.2:69
2477 msgid "RETURN VALUE"
2480 #. FIXME glibc defines the following additional errors, some which
2481 #. can probably be returned by getaddrinfo(); they need to
2484 #. #define EAI_INPROGRESS -100 /* Processing request in progress. */
2485 #. #define EAI_CANCELED -101 /* Request canceled. */
2486 #. #define EAI_NOTCANCELED -102 /* Request not canceled. */
2487 #. #define EAI_ALLDONE -103 /* All requests done. */
2488 #. #define EAI_INTR -104 /* Interrupted by a signal. */
2489 #. #define EAI_IDN_ENCODE -105 /* IDN encoding failed. */
2492 #: build/C/man3/getaddrinfo.3:500
2494 "B<getaddrinfo>() returns 0 if it succeeds, or one of the following nonzero "
2499 #: build/C/man3/getaddrinfo.3:500
2501 msgid "B<EAI_ADDRFAMILY>"
2506 #: build/C/man3/getaddrinfo.3:505
2508 "The specified network host does not have any network addresses in the "
2509 "requested address family."
2513 #: build/C/man3/getaddrinfo.3:505 build/C/man3/getaddrinfo_a.3:247 build/C/man3/getaddrinfo_a.3:264 build/C/man3/getnameinfo.3:155
2515 msgid "B<EAI_AGAIN>"
2519 #: build/C/man3/getaddrinfo.3:509
2520 msgid "The name server returned a temporary failure indication. Try again later."
2524 #: build/C/man3/getaddrinfo.3:509 build/C/man3/getnameinfo.3:159
2526 msgid "B<EAI_BADFLAGS>"
2530 #: build/C/man3/getaddrinfo.3:519
2532 "I<hints.ai_flags> contains invalid flags; or, I<hints.ai_flags> included "
2533 "B<AI_CANONNAME> and I<name> was NULL."
2537 #: build/C/man3/getaddrinfo.3:519 build/C/man3/getnameinfo.3:164
2543 #: build/C/man3/getaddrinfo.3:522
2544 msgid "The name server returned a permanent failure indication."
2548 #: build/C/man3/getaddrinfo.3:522 build/C/man3/getnameinfo.3:167
2550 msgid "B<EAI_FAMILY>"
2554 #: build/C/man3/getaddrinfo.3:525
2555 msgid "The requested address family is not supported."
2559 #: build/C/man3/getaddrinfo.3:525 build/C/man3/getaddrinfo_a.3:252 build/C/man3/getnameinfo.3:171
2561 msgid "B<EAI_MEMORY>"
2565 #: build/C/man3/getaddrinfo.3:528 build/C/man3/getaddrinfo_a.3:255 build/C/man3/getnameinfo.3:174 build/C/man7/unix.7:444
2566 msgid "Out of memory."
2570 #: build/C/man3/getaddrinfo.3:528
2572 msgid "B<EAI_NODATA>"
2577 #: build/C/man3/getaddrinfo.3:533
2579 "The specified network host exists, but does not have any network addresses "
2584 #: build/C/man3/getaddrinfo.3:533 build/C/man3/getnameinfo.3:174
2586 msgid "B<EAI_NONAME>"
2590 #: build/C/man3/getaddrinfo.3:550
2592 "The I<node> or I<service> is not known; or both I<node> and I<service> are "
2593 "NULL; or B<AI_NUMERICSERV> was specified in I<hints.ai_flags> and I<service> "
2594 "was not a numeric port-number string."
2598 #: build/C/man3/getaddrinfo.3:550
2600 msgid "B<EAI_SERVICE>"
2604 #: build/C/man3/getaddrinfo.3:571
2606 "The requested service is not available for the requested socket type. It "
2607 "may be available through another socket type. For example, this error could "
2608 "occur if I<service> was \"shell\" (a service available only on stream "
2609 "sockets), and either I<hints.ai_protocol> was B<IPPROTO_UDP>, or "
2610 "I<hints.ai_socktype> was B<SOCK_DGRAM>; or the error could occur if "
2611 "I<service> was not NULL, and I<hints.ai_socktype> was B<SOCK_RAW> (a socket "
2612 "type that does not support the concept of services)."
2616 #: build/C/man3/getaddrinfo.3:571
2618 msgid "B<EAI_SOCKTYPE>"
2622 #: build/C/man3/getaddrinfo.3:583
2624 "The requested socket type is not supported. This could occur, for example, "
2625 "if I<hints.ai_socktype> and I<hints.ai_protocol> are inconsistent (e.g., "
2626 "B<SOCK_DGRAM> and B<IPPROTO_TCP>, respectively)."
2630 #: build/C/man3/getaddrinfo.3:583 build/C/man3/getaddrinfo_a.3:255 build/C/man3/getnameinfo.3:187
2632 msgid "B<EAI_SYSTEM>"
2636 #: build/C/man3/getaddrinfo.3:588
2637 msgid "Other system error, check I<errno> for details."
2641 #: build/C/man3/getaddrinfo.3:593
2643 "The B<gai_strerror>() function translates these error codes to a human "
2644 "readable string, suitable for error reporting."
2648 #: build/C/man3/getaddrinfo.3:600
2649 msgid "POSIX.1-2001. The B<getaddrinfo>() function is documented in RFC\\ 2553."
2653 #: build/C/man3/getaddrinfo.3:605
2655 "B<getaddrinfo>() supports the I<address>B<%>I<scope-id> notation for "
2656 "specifying the IPv6 scope-ID."
2660 #: build/C/man3/getaddrinfo.3:613
2662 "B<AI_ADDRCONFIG>, B<AI_ALL>, and B<AI_V4MAPPED> are available since glibc "
2663 "2.3.3. B<AI_NUMERICSERV> is available since glibc 2.3.4."
2667 #: build/C/man3/getaddrinfo.3:623
2669 "According to POSIX.1-2001, specifying I<hints> as NULL should cause "
2670 "I<ai_flags> to be assumed as 0. The GNU C library instead assumes a value "
2671 "of B<(AI_V4MAPPED\\ |\\ AI_ADDRCONFIG)> for this case, since this value is "
2672 "considered an improvement on the specification."
2675 #. getnameinfo.3 refers to this example
2676 #. socket.2 refers to this example
2677 #. bind.2 refers to this example
2678 #. connect.2 refers to this example
2679 #. recvfrom.2 refers to this example
2680 #. sendto.2 refers to this example
2682 #: build/C/man3/getaddrinfo.3:637
2684 "The following programs demonstrate the use of B<getaddrinfo>(), "
2685 "B<gai_strerror>(), B<freeaddrinfo>(), and B<getnameinfo>(3). The programs "
2686 "are an echo server and client for UDP datagrams."
2690 #: build/C/man3/getaddrinfo.3:637
2692 msgid "Server program"
2696 #: build/C/man3/getaddrinfo.3:647
2699 "#include E<lt>sys/types.hE<gt>\n"
2700 "#include E<lt>stdio.hE<gt>\n"
2701 "#include E<lt>stdlib.hE<gt>\n"
2702 "#include E<lt>unistd.hE<gt>\n"
2703 "#include E<lt>string.hE<gt>\n"
2704 "#include E<lt>sys/socket.hE<gt>\n"
2705 "#include E<lt>netdb.hE<gt>\n"
2709 #: build/C/man3/getaddrinfo.3:649 build/C/man3/getaddrinfo.3:744
2711 msgid "#define BUF_SIZE 500\n"
2715 #: build/C/man3/getaddrinfo.3:660
2719 "main(int argc, char *argv[])\n"
2721 " struct addrinfo hints;\n"
2722 " struct addrinfo *result, *rp;\n"
2724 " struct sockaddr_storage peer_addr;\n"
2725 " socklen_t peer_addr_len;\n"
2727 " char buf[BUF_SIZE];\n"
2731 #: build/C/man3/getaddrinfo.3:665
2734 " if (argc != 2) {\n"
2735 " fprintf(stderr, \"Usage: %s port\\en\", argv[0]);\n"
2736 " exit(EXIT_FAILURE);\n"
2741 #: build/C/man3/getaddrinfo.3:674
2744 " memset(&hints, 0, sizeof(struct addrinfo));\n"
2745 " hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */\n"
2746 " hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */\n"
2747 " hints.ai_flags = AI_PASSIVE; /* For wildcard IP address */\n"
2748 " hints.ai_protocol = 0; /* Any protocol */\n"
2749 " hints.ai_canonname = NULL;\n"
2750 " hints.ai_addr = NULL;\n"
2751 " hints.ai_next = NULL;\n"
2755 #: build/C/man3/getaddrinfo.3:680
2758 " s = getaddrinfo(NULL, argv[1], &hints, &result);\n"
2760 " fprintf(stderr, \"getaddrinfo: %s\\en\", gai_strerror(s));\n"
2761 " exit(EXIT_FAILURE);\n"
2766 #: build/C/man3/getaddrinfo.3:685
2769 " /* getaddrinfo() returns a list of address structures.\n"
2770 " Try each address until we successfully bind(2).\n"
2771 " If socket(2) (or bind(2)) fails, we (close the socket\n"
2772 " and) try the next address. */\n"
2776 #: build/C/man3/getaddrinfo.3:691
2779 " for (rp = result; rp != NULL; rp = rp-E<gt>ai_next) {\n"
2780 " sfd = socket(rp-E<gt>ai_family, rp-E<gt>ai_socktype,\n"
2781 " rp-E<gt>ai_protocol);\n"
2787 #: build/C/man3/getaddrinfo.3:694
2790 " if (bind(sfd, rp-E<gt>ai_addr, rp-E<gt>ai_addrlen) == 0)\n"
2791 " break; /* Success */\n"
2795 #: build/C/man3/getaddrinfo.3:697 build/C/man3/getaddrinfo.3:790
2803 #: build/C/man3/getaddrinfo.3:702
2806 " if (rp == NULL) { /* No address succeeded */\n"
2807 " fprintf(stderr, \"Could not bind\\en\");\n"
2808 " exit(EXIT_FAILURE);\n"
2813 #: build/C/man3/getaddrinfo.3:704 build/C/man3/getaddrinfo.3:797
2815 msgid " freeaddrinfo(result); /* No longer needed */\n"
2819 #: build/C/man3/getaddrinfo.3:706
2821 msgid " /* Read datagrams and echo them back to sender */\n"
2825 #: build/C/man3/getaddrinfo.3:713
2829 " peer_addr_len = sizeof(struct sockaddr_storage);\n"
2830 " nread = recvfrom(sfd, buf, BUF_SIZE, 0,\n"
2831 " (struct sockaddr *) &peer_addr, &peer_addr_len);\n"
2832 " if (nread == -1)\n"
2833 " continue; /* Ignore failed request */\n"
2837 #: build/C/man3/getaddrinfo.3:715
2839 msgid " char host[NI_MAXHOST], service[NI_MAXSERV];\n"
2843 #: build/C/man3/getaddrinfo.3:724
2846 " s = getnameinfo((struct sockaddr *) &peer_addr,\n"
2847 " peer_addr_len, host, NI_MAXHOST,\n"
2848 " service, NI_MAXSERV, NI_NUMERICSERV);\n"
2850 " printf(\"Received %zd bytes from %s:%s\\en\",\n"
2851 " nread, host, service);\n"
2853 " fprintf(stderr, \"getnameinfo: %s\\en\", gai_strerror(s));\n"
2857 #: build/C/man3/getaddrinfo.3:731
2860 " if (sendto(sfd, buf, nread, 0,\n"
2861 " (struct sockaddr *) &peer_addr,\n"
2862 " peer_addr_len) != nread)\n"
2863 " fprintf(stderr, \"Error sending response\\en\");\n"
2869 #: build/C/man3/getaddrinfo.3:732
2871 msgid "Client program"
2875 #: build/C/man3/getaddrinfo.3:742
2878 "#include E<lt>sys/types.hE<gt>\n"
2879 "#include E<lt>sys/socket.hE<gt>\n"
2880 "#include E<lt>netdb.hE<gt>\n"
2881 "#include E<lt>stdio.hE<gt>\n"
2882 "#include E<lt>stdlib.hE<gt>\n"
2883 "#include E<lt>unistd.hE<gt>\n"
2884 "#include E<lt>string.hE<gt>\n"
2888 #: build/C/man3/getaddrinfo.3:754
2892 "main(int argc, char *argv[])\n"
2894 " struct addrinfo hints;\n"
2895 " struct addrinfo *result, *rp;\n"
2899 " char buf[BUF_SIZE];\n"
2903 #: build/C/man3/getaddrinfo.3:759
2906 " if (argc E<lt> 3) {\n"
2907 " fprintf(stderr, \"Usage: %s host port msg...\\en\", argv[0]);\n"
2908 " exit(EXIT_FAILURE);\n"
2913 #: build/C/man3/getaddrinfo.3:761
2915 msgid " /* Obtain address(es) matching host/port */\n"
2919 #: build/C/man3/getaddrinfo.3:767
2922 " memset(&hints, 0, sizeof(struct addrinfo));\n"
2923 " hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */\n"
2924 " hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */\n"
2925 " hints.ai_flags = 0;\n"
2926 " hints.ai_protocol = 0; /* Any protocol */\n"
2930 #: build/C/man3/getaddrinfo.3:773
2933 " s = getaddrinfo(argv[1], argv[2], &hints, &result);\n"
2935 " fprintf(stderr, \"getaddrinfo: %s\\en\", gai_strerror(s));\n"
2936 " exit(EXIT_FAILURE);\n"
2941 #: build/C/man3/getaddrinfo.3:778
2944 " /* getaddrinfo() returns a list of address structures.\n"
2945 " Try each address until we successfully connect(2).\n"
2946 " If socket(2) (or connect(2)) fails, we (close the socket\n"
2947 " and) try the next address. */\n"
2951 #: build/C/man3/getaddrinfo.3:784
2954 " for (rp = result; rp != NULL; rp = rp-E<gt>ai_next) {\n"
2955 " sfd = socket(rp-E<gt>ai_family, rp-E<gt>ai_socktype,\n"
2956 " rp-E<gt>ai_protocol);\n"
2962 #: build/C/man3/getaddrinfo.3:787
2965 " if (connect(sfd, rp-E<gt>ai_addr, rp-E<gt>ai_addrlen) != -1)\n"
2966 " break; /* Success */\n"
2970 #: build/C/man3/getaddrinfo.3:795
2973 " if (rp == NULL) { /* No address succeeded */\n"
2974 " fprintf(stderr, \"Could not connect\\en\");\n"
2975 " exit(EXIT_FAILURE);\n"
2980 #: build/C/man3/getaddrinfo.3:800
2983 " /* Send remaining command-line arguments as separate\n"
2984 " datagrams, and read responses from server */\n"
2988 #: build/C/man3/getaddrinfo.3:804
2991 " for (j = 3; j E<lt> argc; j++) {\n"
2992 " len = strlen(argv[j]) + 1;\n"
2993 " /* +1 for terminating null byte */\n"
2997 #: build/C/man3/getaddrinfo.3:810
3000 " if (len + 1 E<gt> BUF_SIZE) {\n"
3001 " fprintf(stderr,\n"
3002 " \"Ignoring long message in argument %d\\en\", j);\n"
3008 #: build/C/man3/getaddrinfo.3:815
3011 " if (write(sfd, argv[j], len) != len) {\n"
3012 " fprintf(stderr, \"partial/failed write\\en\");\n"
3013 " exit(EXIT_FAILURE);\n"
3018 #: build/C/man3/getaddrinfo.3:821
3021 " nread = read(sfd, buf, BUF_SIZE);\n"
3022 " if (nread == -1) {\n"
3023 " perror(\"read\");\n"
3024 " exit(EXIT_FAILURE);\n"
3029 #: build/C/man3/getaddrinfo.3:824
3032 " printf(\"Received %zd bytes: %s\\en\", nread, buf);\n"
3036 #. .BR getipnodebyaddr (3),
3037 #. .BR getipnodebyname (3),
3039 #: build/C/man3/getaddrinfo.3:837
3041 "B<getaddrinfo_a>(3), B<gethostbyname>(3), B<getnameinfo>(3), B<inet>(3), "
3042 "B<gai.conf>(5), B<hostname>(7), B<ip>(7)"
3046 #: build/C/man3/getaddrinfo_a.3:29
3048 msgid "GETADDRINFO_A"
3052 #: build/C/man3/getaddrinfo_a.3:29 build/C/man3/getnameinfo.3:10 build/C/man3/inet.3:42 build/C/man3/inet_net_pton.3:26 build/C/man3/rcmd.3:43 build/C/man3/resolver.3:32 build/C/man3/rexec.3:41 build/C/man3/setnetgrent.3:10
3058 #: build/C/man3/getaddrinfo_a.3:33
3060 "getaddrinfo_a, gai_suspend, gai_error, gai_cancel - asynchronous network "
3061 "address and service translation"
3065 #: build/C/man3/getaddrinfo_a.3:37
3068 "B<#define _GNU_SOURCE> /* See feature_test_macros(7) */\n"
3069 "B<#include E<lt>netdb.hE<gt>>\n"
3073 #: build/C/man3/getaddrinfo_a.3:40
3076 "B<int getaddrinfo_a(int >I<mode>B<, struct gaicb *>I<list[]>B<,>\n"
3077 "B< int >I<nitems>B<, struct sigevent *>I<sevp>B<);>\n"
3081 #: build/C/man3/getaddrinfo_a.3:43
3084 "B<int gai_suspend(const struct gaicb * const >I<list[]>B<, int "
3086 "B< const struct timespec *>I<timeout>B<);>\n"
3090 #: build/C/man3/getaddrinfo_a.3:45
3092 msgid "B<int gai_error(struct gaicb *>I<req>B<);>\n"
3096 #: build/C/man3/getaddrinfo_a.3:47
3098 msgid "B<int gai_cancel(struct gaicb *>I<req>B<);>\n"
3102 #: build/C/man3/getaddrinfo_a.3:49
3104 msgid "Link with I<-lanl>.\n"
3108 #: build/C/man3/getaddrinfo_a.3:57
3110 "The B<getaddrinfo_a>() function performs the same task as "
3111 "B<getaddrinfo>(3), but allows multiple name look-ups to be performed "
3112 "asynchronously, with optional notification on completion of look-up "
3117 #: build/C/man3/getaddrinfo_a.3:61
3118 msgid "The I<mode> argument has one of the following values:"
3122 #: build/C/man3/getaddrinfo_a.3:61
3128 #: build/C/man3/getaddrinfo_a.3:65
3130 "Perform the look-ups synchronously. The call blocks until the look-ups have "
3135 #: build/C/man3/getaddrinfo_a.3:65
3137 msgid "B<GAI_NOWAIT>"
3141 #: build/C/man3/getaddrinfo_a.3:73
3143 "Perform the look-ups asynchronously. The call returns immediately, and the "
3144 "requests are resolved in the background. See the discussion of the I<sevp> "
3149 #: build/C/man3/getaddrinfo_a.3:88
3151 "The array I<list> specifies the look-up requests to process. The I<nitems> "
3152 "argument specifies the number of elements in I<list>. The requested look-up "
3153 "operations are started in parallel. NULL elements in I<list> are ignored. "
3154 "Each request is described by a I<gaicb> structure, defined as follows:"
3158 #: build/C/man3/getaddrinfo_a.3:97
3162 " const char *ar_name;\n"
3163 " const char *ar_service;\n"
3164 " const struct addrinfo *ar_request;\n"
3165 " struct addrinfo *ar_result;\n"
3170 #: build/C/man3/getaddrinfo_a.3:128
3172 "The elements of this structure correspond to the arguments of "
3173 "B<getaddrinfo>(3). Thus, I<ar_name> corresponds to the I<node> argument and "
3174 "I<ar_service> to the I<service> argument, identifying an Internet host and a "
3175 "service. The I<ar_request> element corresponds to the I<hints> argument, "
3176 "specifying the criteria for selecting the returned socket address "
3177 "structures. Finally, I<ar_result> corresponds to the I<res> argument; you "
3178 "do not need to initialize this element, it will be automatically set when "
3179 "the request is resolved. The I<addrinfo> structure referenced by the last "
3180 "two elements is described in B<getaddrinfo>(3)."
3184 #: build/C/man3/getaddrinfo_a.3:144
3186 "When I<mode> is specified as B<GAI_NOWAIT>, notifications about resolved "
3187 "requests can be obtained by employing the I<sigevent> structure pointed to "
3188 "by the I<sevp> argument. For the definition and general details of this "
3189 "structure, see B<sigevent>(7). The I<sevp-E<gt>sigev_notify> field can have "
3190 "the following values:"
3194 #: build/C/man3/getaddrinfo_a.3:144
3196 msgid "B<SIGEV_NONE>"
3200 #: build/C/man3/getaddrinfo_a.3:147
3201 msgid "Don't provide any notification."
3205 #: build/C/man3/getaddrinfo_a.3:147
3207 msgid "B<SIGEV_SIGNAL>"
3210 #. si_pid and si_uid are also set, to the values of the calling process,
3211 #. which doesn't provide useful information, so we'll skip mentioning it.
3213 #: build/C/man3/getaddrinfo_a.3:163
3215 "When a look-up completes, generate the signal I<sigev_signo> for the "
3216 "process. See B<sigevent>(7) for general details. The I<si_code> field of "
3217 "the I<siginfo_t> structure will be set to B<SI_ASYNCNL>."
3221 #: build/C/man3/getaddrinfo_a.3:163
3223 msgid "B<SIGEV_THREAD>"
3227 #: build/C/man3/getaddrinfo_a.3:171
3229 "When a look-up completes, invoke I<sigev_notify_function> as if it were the "
3230 "start function of a new thread. See B<sigevent>(7) for details."
3234 #: build/C/man3/getaddrinfo_a.3:180
3236 "For B<SIGEV_SIGNAL> and B<SIGEV_THREAD>, it may be useful to point "
3237 "I<sevp-E<gt>sigev_value.sival_ptr> to I<list>."
3241 #: build/C/man3/getaddrinfo_a.3:191
3243 "The B<gai_suspend>() function suspends execution of the calling thread, "
3244 "waiting for the completion of one or more requests in the array I<list>. "
3245 "The I<nitems> argument specifies the size of the array I<list>. The call "
3246 "blocks until one of the following occurs:"
3250 #: build/C/man3/getaddrinfo_a.3:195
3251 msgid "One or more of the operations in I<list> completes."
3255 #: build/C/man3/getaddrinfo_a.3:197
3256 msgid "The call is interrupted by a signal that is caught."
3260 #: build/C/man3/getaddrinfo_a.3:210
3262 "The time interval specified in I<timeout> elapses. This argument specifies "
3263 "a timeout in seconds plus nanoseconds (see B<nanosleep>(2) for details of "
3264 "the I<timespec> structure). If I<timeout> is NULL, then the call blocks "
3265 "indefinitely (until one of the events above occurs)."
3269 #: build/C/man3/getaddrinfo_a.3:215
3271 "No explicit indication of which request was completed is given; you must "
3272 "determine which request(s) have completed by iterating with B<gai_error>() "
3273 "over the list of requests."
3277 #: build/C/man3/getaddrinfo_a.3:225
3279 "The B<gai_error>() function returns the status of the request I<req>: "
3280 "either B<EAI_INPROGRESS> if the request was not completed yet, 0 if it was "
3281 "handled successfully, or an error code if the request could not be resolved."
3285 #: build/C/man3/getaddrinfo_a.3:242
3287 "The B<gai_cancel>() function cancels the request I<req>. If the request "
3288 "has been canceled successfully, the error status of the request will be set "
3289 "to B<EAI_CANCELLED> and normal asynchronous notification will be performed. "
3290 "The request cannot be canceled if it is currently being processed; in that "
3291 "case, it will be handled as if B<gai_cancel>() has never been called. If "
3292 "I<req> is NULL, an attempt is made to cancel all outstanding requests that "
3293 "the process has made."
3297 #: build/C/man3/getaddrinfo_a.3:247
3299 "The B<getaddrinfo_a>() function returns 0 if all of the requests have been "
3300 "enqueued successfully, or one of the following nonzero error codes:"
3304 #: build/C/man3/getaddrinfo_a.3:252
3306 "The resources necessary to enqueue the look-up requests were not available. "
3307 "The application may check the error status of each request to determine "
3308 "which ones failed."
3312 #: build/C/man3/getaddrinfo_a.3:259
3313 msgid "I<mode> is invalid."
3317 #: build/C/man3/getaddrinfo_a.3:264
3319 "The B<gai_suspend>() function returns 0 if at least one of the listed "
3320 "requests has been completed. Otherwise, it returns one of the following "
3321 "nonzero error codes:"
3325 #: build/C/man3/getaddrinfo_a.3:267
3326 msgid "The given timeout expired before any of the requests could be completed."
3330 #: build/C/man3/getaddrinfo_a.3:267 build/C/man3/getaddrinfo_a.3:297
3332 msgid "B<EAI_ALLDONE>"
3336 #: build/C/man3/getaddrinfo_a.3:270
3337 msgid "There were no actual requests given to the function."
3341 #: build/C/man3/getaddrinfo_a.3:270
3347 #: build/C/man3/getaddrinfo_a.3:275
3349 "A signal has interrupted the function. Note that this interruption might "
3350 "have been caused by signal notification of some completed look-up request."
3354 #: build/C/man3/getaddrinfo_a.3:287
3356 "The B<gai_error>() function can return B<EAI_INPROGRESS> for an unfinished "
3357 "look-up request, 0 for a successfully completed look-up (as described "
3358 "above), one of the error codes that could be returned by B<getaddrinfo>(3), "
3359 "or the error code B<EAI_CANCELLED> if the request has been canceled "
3360 "explicitly before it could be finished."
3364 #: build/C/man3/getaddrinfo_a.3:291
3365 msgid "The B<gai_cancel>() function can return one of these values:"
3369 #: build/C/man3/getaddrinfo_a.3:291
3371 msgid "B<EAI_CANCELLED>"
3375 #: build/C/man3/getaddrinfo_a.3:294
3376 msgid "The request has been canceled successfully."
3380 #: build/C/man3/getaddrinfo_a.3:294
3382 msgid "B<EAI_NOTCANCELLED>"
3386 #: build/C/man3/getaddrinfo_a.3:297
3387 msgid "The request has not been canceled."
3391 #: build/C/man3/getaddrinfo_a.3:300
3392 msgid "The request has already completed."
3396 #: build/C/man3/getaddrinfo_a.3:305 build/C/man3/getnameinfo.3:197
3398 "The B<gai_strerror>(3) function translates these error codes to a human "
3399 "readable string, suitable for error reporting."
3403 #: build/C/man3/getaddrinfo_a.3:308
3405 "These functions are GNU extensions; they first appeared in glibc in version "
3410 #: build/C/man3/getaddrinfo_a.3:314
3412 "The interface of B<getaddrinfo_a>() was modeled after the B<lio_listio>(3) "
3417 #: build/C/man3/getaddrinfo_a.3:318
3419 "Two examples are provided: a simple example that resolves several requests "
3420 "in parallel synchronously, and a complex example showing some of the "
3421 "asynchronous capabilities."
3425 #: build/C/man3/getaddrinfo_a.3:318
3427 msgid "Synchronous example"
3431 #: build/C/man3/getaddrinfo_a.3:323
3433 "The program below simply resolves several hostnames in parallel, giving a "
3434 "speed-up compared to resolving the hostnames sequentially using "
3435 "B<getaddrinfo>(3). The program might be used like this:"
3439 #: build/C/man3/getaddrinfo_a.3:330
3442 "$ B<./a.out ftp.us.kernel.org enoent.linuxfoundation.org gnu.cz>\n"
3443 "ftp.us.kernel.org: 128.30.2.36\n"
3444 "enoent.linuxfoundation.org: Name or service not known\n"
3445 "gnu.cz: 87.236.197.13\n"
3449 #: build/C/man3/getaddrinfo_a.3:334
3450 msgid "Here is the program source code"
3454 #: build/C/man3/getaddrinfo_a.3:341 build/C/man3/getaddrinfo_a.3:430
3457 "#define _GNU_SOURCE\n"
3458 "#include E<lt>netdb.hE<gt>\n"
3459 "#include E<lt>stdio.hE<gt>\n"
3460 "#include E<lt>stdlib.hE<gt>\n"
3461 "#include E<lt>string.hE<gt>\n"
3465 #: build/C/man3/getaddrinfo_a.3:349
3469 "main(int argc, char *argv[])\n"
3472 " struct gaicb *reqs[argc - 1];\n"
3473 " char host[NI_MAXHOST];\n"
3474 " struct addrinfo *res;\n"
3478 #: build/C/man3/getaddrinfo_a.3:354
3481 " if (argc E<lt> 2) {\n"
3482 " fprintf(stderr, \"Usage: %s HOST...\\en\", argv[0]);\n"
3483 " exit(EXIT_FAILURE);\n"
3488 #: build/C/man3/getaddrinfo_a.3:364
3491 " for (i = 0; i E<lt> argc - 1; i++) {\n"
3492 " reqs[i] = malloc(sizeof(*reqs[0]));\n"
3493 " if (reqs[i] == NULL) {\n"
3494 " perror(\"malloc\");\n"
3495 " exit(EXIT_FAILURE);\n"
3497 " memset(reqs[i], 0, sizeof(*reqs[0]));\n"
3498 " reqs[i]-E<gt>ar_name = argv[i + 1];\n"
3503 #: build/C/man3/getaddrinfo_a.3:371
3506 " ret = getaddrinfo_a(GAI_WAIT, reqs, argc - 1, NULL);\n"
3507 " if (ret != 0) {\n"
3508 " fprintf(stderr, \"getaddrinfo_a() failed: %s\\en\",\n"
3509 " gai_strerror(ret));\n"
3510 " exit(EXIT_FAILURE);\n"
3515 #: build/C/man3/getaddrinfo_a.3:377
3518 " for (i = 0; i E<lt> argc - 1; i++) {\n"
3519 " printf(\"%s: \", reqs[i]-E<gt>ar_name);\n"
3520 " ret = gai_error(reqs[i]);\n"
3521 " if (ret == 0) {\n"
3522 " res = reqs[i]-E<gt>ar_result;\n"
3526 #: build/C/man3/getaddrinfo_a.3:387
3529 " ret = getnameinfo(res-E<gt>ai_addr, res-E<gt>ai_addrlen,\n"
3530 " host, sizeof(host),\n"
3531 " NULL, 0, NI_NUMERICHOST);\n"
3532 " if (ret != 0) {\n"
3533 " fprintf(stderr, \"getnameinfo() failed: %s\\en\",\n"
3534 " gai_strerror(ret));\n"
3535 " exit(EXIT_FAILURE);\n"
3541 #: build/C/man3/getaddrinfo_a.3:394
3545 " puts(gai_strerror(ret));\n"
3548 " exit(EXIT_SUCCESS);\n"
3553 #: build/C/man3/getaddrinfo_a.3:395
3555 msgid "Asynchronous example"
3559 #: build/C/man3/getaddrinfo_a.3:400
3561 "This example shows a simple interactive B<getaddrinfo_a>() front-end. The "
3562 "notification facility is not demonstrated."
3566 #: build/C/man3/getaddrinfo_a.3:402
3567 msgid "An example session might look like this:"
3571 #: build/C/man3/getaddrinfo_a.3:419
3575 "E<gt> a ftp.us.kernel.org enoent.linuxfoundation.org gnu.cz\n"
3577 "[2] gnu.cz: Request not canceled\n"
3579 "[00] ftp.us.kernel.org: Finished\n"
3581 "[00] ftp.us.kernel.org: 216.165.129.139\n"
3582 "[01] enoent.linuxfoundation.org: Processing request in progress\n"
3583 "[02] gnu.cz: 87.236.197.13\n"
3585 "[00] ftp.us.kernel.org: 216.165.129.139\n"
3586 "[01] enoent.linuxfoundation.org: Name or service not known\n"
3587 "[02] gnu.cz: 87.236.197.13\n"
3591 #: build/C/man3/getaddrinfo_a.3:423
3592 msgid "The program source is as follows:"
3596 #: build/C/man3/getaddrinfo_a.3:433
3599 "static struct gaicb **reqs = NULL;\n"
3600 "static int nreqs = 0;\n"
3604 #: build/C/man3/getaddrinfo_a.3:438
3610 " static char buf[256];\n"
3614 #: build/C/man3/getaddrinfo_a.3:442
3617 " fputs(\"E<gt> \", stdout); fflush(stdout);\n"
3618 " if (fgets(buf, sizeof(buf), stdin) == NULL)\n"
3623 #: build/C/man3/getaddrinfo_a.3:445
3626 " if (buf[strlen(buf) - 1] == \\(aq\\en\\(aq)\n"
3627 " buf[strlen(buf) - 1] = 0;\n"
3631 #: build/C/man3/getaddrinfo_a.3:448
3639 #: build/C/man3/getaddrinfo_a.3:456
3642 "/* Add requests for specified hostnames */\n"
3644 "add_requests(void)\n"
3646 " int nreqs_base = nreqs;\n"
3652 #: build/C/man3/getaddrinfo_a.3:460
3655 " while ((host = strtok(NULL, \" \"))) {\n"
3657 " reqs = realloc(reqs, nreqs * sizeof(reqs[0]));\n"
3661 #: build/C/man3/getaddrinfo_a.3:464
3664 " reqs[nreqs - 1] = calloc(1, sizeof(*reqs[0]));\n"
3665 " reqs[nreqs - 1]-E<gt>ar_name = strdup(host);\n"
3670 #: build/C/man3/getaddrinfo_a.3:466
3672 msgid " /* Queue nreqs_base..nreqs requests. */\n"
3676 #: build/C/man3/getaddrinfo_a.3:475
3679 " ret = getaddrinfo_a(GAI_NOWAIT, &reqs[nreqs_base],\n"
3680 " nreqs - nreqs_base, NULL);\n"
3682 " fprintf(stderr, \"getaddrinfo_a() failed: %s\\en\",\n"
3683 " gai_strerror(ret));\n"
3684 " exit(EXIT_FAILURE);\n"
3690 #: build/C/man3/getaddrinfo_a.3:484
3693 "/* Wait until at least one of specified requests completes */\n"
3695 "wait_requests(void)\n"
3699 " struct gaicb const **wait_reqs = calloc(nreqs, sizeof(*wait_reqs));\n"
3700 " /* NULL elements are ignored by gai_suspend(). */\n"
3704 #: build/C/man3/getaddrinfo_a.3:487 build/C/man3/getaddrinfo_a.3:524
3707 " while ((id = strtok(NULL, \" \")) != NULL) {\n"
3712 #: build/C/man3/getaddrinfo_a.3:492 build/C/man3/getaddrinfo_a.3:529
3715 " if (n E<gt>= nreqs) {\n"
3716 " printf(\"Bad request number: %s\\en\", id);\n"
3722 #: build/C/man3/getaddrinfo_a.3:495
3725 " wait_reqs[n] = reqs[n];\n"
3730 #: build/C/man3/getaddrinfo_a.3:501
3733 " ret = gai_suspend(wait_reqs, nreqs, NULL);\n"
3735 " printf(\"gai_suspend(): %s\\en\", gai_strerror(ret));\n"
3741 #: build/C/man3/getaddrinfo_a.3:505
3744 " for (i = 0; i E<lt> nreqs; i++) {\n"
3745 " if (wait_reqs[i] == NULL)\n"
3750 #: build/C/man3/getaddrinfo_a.3:509
3753 " ret = gai_error(reqs[i]);\n"
3754 " if (ret == EAI_INPROGRESS)\n"
3759 #: build/C/man3/getaddrinfo_a.3:514
3762 " printf(\"[%02d] %s: %s\\en\", i, reqs[i]-E<gt>ar_name,\n"
3763 " ret == 0 ? \"Finished\" : gai_strerror(ret));\n"
3769 #: build/C/man3/getaddrinfo_a.3:521
3772 "/* Cancel specified requests */\n"
3774 "cancel_requests(void)\n"
3781 #: build/C/man3/getaddrinfo_a.3:535
3784 " ret = gai_cancel(reqs[n]);\n"
3785 " printf(\"[%s] %s: %s\\en\", id, reqs[atoi(id)]-E<gt>ar_name,\n"
3786 " gai_strerror(ret));\n"
3792 #: build/C/man3/getaddrinfo_a.3:543
3795 "/* List all requests */\n"
3797 "list_requests(void)\n"
3800 " char host[NI_MAXHOST];\n"
3801 " struct addrinfo *res;\n"
3805 #: build/C/man3/getaddrinfo_a.3:547
3808 " for (i = 0; i E<lt> nreqs; i++) {\n"
3809 " printf(\"[%02d] %s: \", i, reqs[i]-E<gt>ar_name);\n"
3810 " ret = gai_error(reqs[i]);\n"
3814 #: build/C/man3/getaddrinfo_a.3:550
3818 " res = reqs[i]-E<gt>ar_result;\n"
3822 #: build/C/man3/getaddrinfo_a.3:565
3825 " ret = getnameinfo(res-E<gt>ai_addr, res-E<gt>ai_addrlen,\n"
3826 " host, sizeof(host),\n"
3827 " NULL, 0, NI_NUMERICHOST);\n"
3829 " fprintf(stderr, \"getnameinfo() failed: %s\\en\",\n"
3830 " gai_strerror(ret));\n"
3831 " exit(EXIT_FAILURE);\n"
3835 " puts(gai_strerror(ret));\n"
3842 #: build/C/man3/getaddrinfo_a.3:571
3846 "main(int argc, char *argv[])\n"
3853 #: build/C/man3/getaddrinfo_a.3:574
3856 " while ((cmdline = getcmd()) != NULL) {\n"
3857 " cmd = strtok(cmdline, \" \");\n"
3861 #: build/C/man3/getaddrinfo_a.3:599
3864 " if (cmd == NULL) {\n"
3865 " list_requests();\n"
3867 " switch (cmd[0]) {\n"
3868 " case \\(aqa\\(aq:\n"
3869 " add_requests();\n"
3871 " case \\(aqw\\(aq:\n"
3872 " wait_requests();\n"
3874 " case \\(aqc\\(aq:\n"
3875 " cancel_requests();\n"
3877 " case \\(aql\\(aq:\n"
3878 " list_requests();\n"
3881 " fprintf(stderr, \"Bad command: %c\\en\", cmd[0]);\n"
3886 " exit(EXIT_SUCCESS);\n"
3891 #: build/C/man3/getaddrinfo_a.3:606
3893 "B<getaddrinfo>(3), B<inet>(3), B<lio_listio>(3), B<hostname>(7), B<ip>(7), "
3898 #: build/C/man1/getent.1:24
3904 #: build/C/man1/getent.1:24
3910 #: build/C/man1/getent.1:24
3912 msgid "User Commands"
3916 #: build/C/man1/getent.1:27
3917 msgid "getent - get entries from Name Service Switch libraries"
3921 #: build/C/man1/getent.1:30
3922 msgid "B<getent> I<database> [I<key> ...]"
3926 #: build/C/man1/getent.1:45
3928 "The B<getent> command displays entries from databases supported by the Name "
3929 "Service Switch libraries, which are configured in I</etc/nsswitch.conf>. If "
3930 "one or more I<key> arguments are provided, then only the entries that match "
3931 "the supplied keys will be displayed. Otherwise, if no I<key> is provided, "
3932 "all entries will be displayed (unless the database does not support "
3937 #: build/C/man1/getent.1:49
3939 "The I<database> may be any of those supported by the GNU C Library, listed "
3944 #: build/C/man1/getent.1:50
3950 #: build/C/man1/getent.1:71
3952 "When no I<key> is provided, use B<sethostent>(3), B<gethostent>(3), and "
3953 "B<endhostent>(3) to enumerate the hosts database. This is identical to "
3954 "using B<hosts>. When one or more I<key> arguments are provided, pass each "
3955 "I<key> in succession to B<getaddrinfo>(3) with the address family "
3956 "B<AF_UNSPEC>, enumerating each socket address structure returned."
3960 #: build/C/man1/getent.1:71
3966 #: build/C/man1/getent.1:77
3967 msgid "Same as B<ahosts>, but use the address family B<AF_INET>."
3971 #: build/C/man1/getent.1:77
3977 #: build/C/man1/getent.1:88
3979 "Same as B<ahosts>, but use the address family B<AF_INET6>. The call to "
3980 "B<getaddrinfo>(3) in this case includes the B<AI_V4MAPPED> flag."
3984 #: build/C/man1/getent.1:88 build/C/man5/nsswitch.conf.5:44
3990 #: build/C/man1/getent.1:105
3992 "When no I<key> is provided, use B<setaliasent>(3), B<getaliasent>(3), and "
3993 "B<endaliasent>(3) to enumerate the aliases database. When one or more "
3994 "I<key> arguments are provided, pass each I<key> in succession to "
3995 "B<getaliasbyname>(3) and display the result."
3999 #: build/C/man1/getent.1:105 build/C/man5/nsswitch.conf.5:49
4005 #: build/C/man1/getent.1:121
4007 "When one or more I<key> arguments are provided, pass each I<key> in "
4008 "succession to B<ether_aton>(3) and B<ether_hostton>(3) until a result is "
4009 "obtained, and display the result. Enumeration is not supported on "
4010 "B<ethers>, so a I<key> must be provided."
4014 #: build/C/man1/getent.1:121 build/C/man5/nsswitch.conf.5:52
4020 #: build/C/man1/getent.1:142
4022 "When no I<key> is provided, use B<setgrent>(3), B<getgrent>(3), and "
4023 "B<endgrent>(3) to enumerate the group database. When one or more I<key> "
4024 "arguments are provided, pass each numeric I<key> to B<getgrgid>(3) and each "
4025 "nonnumeric I<key> to B<getgrnam>(3) and display the result."
4029 #: build/C/man1/getent.1:142
4035 #: build/C/man1/getent.1:159
4037 "When no I<key> is provided, use B<setsgent>(3), B<getsgent>(3), and "
4038 "B<endsgent>(3) to enumerate the gshadow database. When one or more I<key> "
4039 "arguments are provided, pass each I<key> in succession to B<getsgnam>(3) "
4040 "and display the result."
4044 #: build/C/man1/getent.1:159 build/C/man5/nsswitch.conf.5:57
4050 #: build/C/man1/getent.1:182
4052 "When no I<key> is provided, use B<sethostent>(3), B<gethostent>(3), and "
4053 "B<endhostent>(3) to enumerate the hosts database. When one or more I<key> "
4054 "arguments are provided, pass each I<key> to B<gethostbyaddr>(3) or "
4055 "B<gethostbyname2>(3), depending on whether a call to B<inet_pton>(3) "
4056 "indicates that the I<key> is an IPv6 or IPv4 address or not, and display the "
4061 #: build/C/man1/getent.1:182 build/C/man5/nsswitch.conf.5:62
4063 msgid "B<initgroups>"
4067 #: build/C/man1/getent.1:196
4069 "When one or more I<key> arguments are provided, pass each I<key> in "
4070 "succession to B<getgrouplist>(3) and display the result. Enumeration is "
4071 "not supported on B<initgroups>, so a I<key> must be provided."
4075 #: build/C/man1/getent.1:196 build/C/man5/nsswitch.conf.5:67
4081 #: build/C/man1/getent.1:222
4083 "When one I<key> is provided, pass the I<key> to B<setnetgrent>(3) and, "
4084 "using B<getnetgrent>(3) display the resulting string triple (I<hostname>, "
4085 "I<username>, I<domainname>). Alternatively, three I<keys> may be provided, "
4086 "which are interpreted as the I<hostname>, I<username> and I<domainname> to "
4087 "match to a netgroup name via B<innetgr>(3). Enumeration is not supported on "
4088 "B<netgroup>, so either one or three I<keys> must be provided."
4092 #: build/C/man1/getent.1:222 build/C/man5/nsswitch.conf.5:71
4098 #: build/C/man1/getent.1:243
4100 "When no I<key> is provided, use B<setnetent>(3), B<getnetent>(3), and "
4101 "B<endnetent>(3) to enumerate the networks database. When one or more "
4102 "I<key> arguments are provided, pass each numeric I<key> to "
4103 "B<getnetbyaddr>(3) and each nonnumeric I<key> to B<getnetbyname>(3) and "
4104 "display the result."
4108 #: build/C/man1/getent.1:243 build/C/man5/nsswitch.conf.5:76
4114 #: build/C/man1/getent.1:264
4116 "When no I<key> is provided, use B<setpwent>(3), B<getpwent>(3), and "
4117 "B<endpwent>(3) to enumerate the passwd database. When one or more I<key> "
4118 "arguments are provided, pass each numeric I<key> to B<getpwuid>(3) and each "
4119 "nonnumeric I<key> to B<getpwnam>(3) and display the result."
4123 #: build/C/man1/getent.1:264 build/C/man5/nsswitch.conf.5:81
4125 msgid "B<protocols>"
4129 #: build/C/man1/getent.1:285
4131 "When no I<key> is provided, use B<setprotoent>(3), B<getprotoent>(3), and "
4132 "B<endprotoent>(3) to enumerate the protocols database. When one or more "
4133 "I<key> arguments are provided, pass each numeric I<key> to "
4134 "B<getprotobynumber>(3) and each nonnumeric I<key> to B<getprotobyname>(3) "
4135 "and display the result."
4139 #: build/C/man1/getent.1:285 build/C/man5/nsswitch.conf.5:89
4145 #: build/C/man1/getent.1:306
4147 "When no I<key> is provided, use B<setrpcent>(3), B<getrpcent>(3), and "
4148 "B<endrpcent>(3) to enumerate the rpc database. When one or more I<key> "
4149 "arguments are provided, pass each numeric I<key> to B<getrpcbynumber>(3) "
4150 "and each nonnumeric I<key> to B<getrpcbyname>(3) and display the result."
4154 #: build/C/man1/getent.1:306 build/C/man5/nsswitch.conf.5:94
4160 #: build/C/man1/getent.1:327
4162 "When no I<key> is provided, use B<setservent>(3), B<getservent>(3), and "
4163 "B<endservent>(3) to enumerate the services database. When one or more "
4164 "I<key> arguments are provided, pass each numeric I<key> to "
4165 "B<getservbynumber>(3) and each nonnumeric I<key> to B<getservbyname>(3) "
4166 "and display the result."
4170 #: build/C/man1/getent.1:327 build/C/man5/nsswitch.conf.5:99
4176 #: build/C/man1/getent.1:344
4178 "When no I<key> is provided, use B<setspent>(3), B<getspent>(3), and "
4179 "B<endspent>(3) to enumerate the shadow database. When one or more I<key> "
4180 "arguments are provided, pass each I<key> in succession to B<getspnam>(3) "
4181 "and display the result."
4185 #: build/C/man1/getent.1:345
4191 #: build/C/man1/getent.1:348
4192 msgid "One of the following exit values can be returned by B<getent>:"
4196 #: build/C/man1/getent.1:349
4202 #: build/C/man1/getent.1:352
4203 msgid "Command completed successfully."
4207 #: build/C/man1/getent.1:352
4213 #: build/C/man1/getent.1:357
4214 msgid "Missing arguments, or I<database> unknown."
4218 #: build/C/man1/getent.1:357
4224 #: build/C/man1/getent.1:363
4225 msgid "One or more supplied I<key> could not be found in the I<database>."
4229 #: build/C/man1/getent.1:363
4235 #: build/C/man1/getent.1:367
4236 msgid "Enumeration not supported on this I<database>."
4240 #: build/C/man1/getent.1:369
4241 msgid "B<nsswitch.conf>(5)"
4245 #: build/C/man3/gethostbyname.3:38
4247 msgid "GETHOSTBYNAME"
4251 #: build/C/man3/gethostbyname.3:38
4257 #: build/C/man3/gethostbyname.3:46
4259 "gethostbyname, gethostbyaddr, sethostent, gethostent, endhostent, h_errno, "
4260 "herror, hstrerror, gethostbyaddr_r, gethostbyname2, gethostbyname2_r, "
4261 "gethostbyname_r, gethostent_r - get network host entry"
4265 #: build/C/man3/gethostbyname.3:50
4268 "B<#include E<lt>netdb.hE<gt>>\n"
4269 "B<extern int h_errno;>\n"
4273 #: build/C/man3/gethostbyname.3:52
4275 msgid "B<struct hostent *gethostbyname(const char *>I<name>B<);>\n"
4279 #: build/C/man3/gethostbyname.3:56
4282 "B<#include E<lt>sys/socket.hE<gt>> /* for AF_INET */\n"
4283 "B<struct hostent *gethostbyaddr(const void *>I<addr>B<,>\n"
4284 "B< socklen_t >I<len>B<, int >I<type>B<);>\n"
4288 #: build/C/man3/gethostbyname.3:58
4290 msgid "B<void sethostent(int >I<stayopen>B<);>\n"
4294 #: build/C/man3/gethostbyname.3:60
4296 msgid "B<void endhostent(void);>\n"
4300 #: build/C/man3/gethostbyname.3:62
4302 msgid "B<void herror(const char *>I<s>B<);>\n"
4306 #: build/C/man3/gethostbyname.3:64
4308 msgid "B<const char *hstrerror(int >I<err>B<);>\n"
4312 #: build/C/man3/gethostbyname.3:66
4314 msgid "/* System V/POSIX extension */\n"
4318 #: build/C/man3/gethostbyname.3:68
4320 msgid "B<struct hostent *gethostent(void);>\n"
4324 #: build/C/man3/gethostbyname.3:72
4326 msgid "B<struct hostent *gethostbyname2(const char *>I<name>B<, int >I<af>B<);>\n"
4330 #: build/C/man3/gethostbyname.3:76
4333 "B<int gethostent_r(>\n"
4334 "B< struct hostent *>I<ret>B<, char *>I<buf>B<, size_t "
4336 "B< struct hostent **>I<result>B<, int *>I<h_errnop>B<);>\n"
4340 #: build/C/man3/gethostbyname.3:80
4343 "B<int gethostbyaddr_r(const void *>I<addr>B<, socklen_t >I<len>B<, int "
4345 "B< struct hostent *>I<ret>B<, char *>I<buf>B<, size_t "
4347 "B< struct hostent **>I<result>B<, int *>I<h_errnop>B<);>\n"
4351 #: build/C/man3/gethostbyname.3:84
4354 "B<int gethostbyname_r(const char *>I<name>B<,>\n"
4355 "B< struct hostent *>I<ret>B<, char *>I<buf>B<, size_t "
4357 "B< struct hostent **>I<result>B<, int *>I<h_errnop>B<);>\n"
4361 #: build/C/man3/gethostbyname.3:88
4364 "B<int gethostbyname2_r(const char *>I<name>B<, int >I<af,>\n"
4365 "B< struct hostent *>I<ret>B<, char *>I<buf>B<, size_t "
4367 "B< struct hostent **>I<result>B<, int *>I<h_errnop>B<);>\n"
4371 #: build/C/man3/gethostbyname.3:102
4373 "B<gethostbyname2>(), B<gethostent_r>(), B<gethostbyaddr_r>(), "
4374 "B<gethostbyname_r>(), B<gethostbyname2_r>():"
4378 #: build/C/man3/gethostbyname.3:104 build/C/man3/gethostbyname.3:112 build/C/man3/getnetent_r.3:60 build/C/man3/getprotoent_r.3:57 build/C/man3/getservent_r.3:57 build/C/man3/inet_net_pton.3:58
4379 msgid "_BSD_SOURCE || _SVID_SOURCE"
4383 #: build/C/man3/gethostbyname.3:108
4384 msgid "B<herror>(), B<hstrerror>():"
4388 #: build/C/man3/gethostbyname.3:109
4390 msgid "Since glibc 2.8:"
4394 #: build/C/man3/gethostbyname.3:112
4396 msgid "Before glibc 2.8:"
4400 #: build/C/man3/gethostbyname.3:115 build/C/man3/gethostbyname.3:126
4405 #: build/C/man3/gethostbyname.3:118
4410 #: build/C/man3/gethostbyname.3:119
4412 msgid "Since glibc 2.12:"
4416 #: build/C/man3/gethostbyname.3:123
4419 "_BSD_SOURCE || _SVID_SOURCE ||\n"
4420 " (_POSIX_C_SOURCE E<lt> 200809L && _XOPEN_SOURCE E<lt> 700)\n"
4424 #: build/C/man3/gethostbyname.3:123
4426 msgid "Before glibc 2.12:"
4430 #: build/C/man3/gethostbyname.3:143
4432 "The B<gethostbyname*>(), B<gethostbyaddr*>(), B<herror>(), and "
4433 "B<hstrerror>() functions are obsolete. Applications should use "
4434 "B<getaddrinfo>(3), B<getnameinfo>(3), and B<gai_strerror>(3) instead."
4438 #: build/C/man3/gethostbyname.3:184
4440 "The B<gethostbyname>() function returns a structure of type I<hostent> for "
4441 "the given host I<name>. Here I<name> is either a hostname, or an IPv4 "
4442 "address in standard dot notation (as for B<inet_addr>(3)), or an IPv6 "
4443 "address in colon (and possibly dot) notation. (See RFC\\ 1884 for the "
4444 "description of IPv6 addresses.) If I<name> is an IPv4 or IPv6 address, no "
4445 "lookup is performed and B<gethostbyname>() simply copies I<name> into the "
4446 "I<h_name> field and its I<struct in_addr> equivalent into the "
4447 "I<h_addr_list[0]> field of the returned I<hostent> structure. If I<name> "
4448 "doesn't end in a dot and the environment variable B<HOSTALIASES> is set, the "
4449 "alias file pointed to by B<HOSTALIASES> will first be searched for I<name> "
4450 "(see B<hostname>(7) for the file format). The current domain and its "
4451 "parents are searched unless I<name> ends in a dot."
4455 #: build/C/man3/gethostbyname.3:200
4457 "The B<gethostbyaddr>() function returns a structure of type I<hostent> for "
4458 "the given host address I<addr> of length I<len> and address type I<type>. "
4459 "Valid address types are B<AF_INET> and B<AF_INET6>. The host address "
4460 "argument is a pointer to a struct of a type depending on the address type, "
4461 "for example a I<struct in_addr *> (probably obtained via a call to "
4462 "B<inet_addr>(3)) for address type B<AF_INET>."
4466 #: build/C/man3/gethostbyname.3:207
4468 "The B<sethostent>() function specifies, if I<stayopen> is true (1), that a "
4469 "connected TCP socket should be used for the name server queries and that the "
4470 "connection should remain open during successive queries. Otherwise, name "
4471 "server queries will use UDP datagrams."
4475 #: build/C/man3/gethostbyname.3:212
4477 "The B<endhostent>() function ends the use of a TCP connection for name "
4482 #: build/C/man3/gethostbyname.3:217
4484 "The (obsolete) B<herror>() function prints the error message associated "
4485 "with the current value of I<h_errno> on I<stderr>."
4489 #: build/C/man3/gethostbyname.3:222
4491 "The (obsolete) B<hstrerror>() function takes an error number (typically "
4492 "I<h_errno>) and returns the corresponding message string."
4496 #. .BR resolv+ (8)).
4498 #: build/C/man3/gethostbyname.3:239
4500 "The domain name queries carried out by B<gethostbyname>() and "
4501 "B<gethostbyaddr>() use a combination of any or all of the name server "
4502 "B<named>(8), a broken out line from I</etc/hosts>, and the Network "
4503 "Information Service (NIS or YP), depending upon the contents of the I<order> "
4504 "line in I</etc/host.conf>. The default action is to query B<named>(8), "
4505 "followed by I</etc/hosts>."
4509 #: build/C/man3/gethostbyname.3:241
4510 msgid "The I<hostent> structure is defined in I<E<lt>netdb.hE<gt>> as follows:"
4514 #: build/C/man3/gethostbyname.3:253
4517 "struct hostent {\n"
4518 " char *h_name; /* official name of host */\n"
4519 " char **h_aliases; /* alias list */\n"
4520 " int h_addrtype; /* host address type */\n"
4521 " int h_length; /* length of address */\n"
4522 " char **h_addr_list; /* list of addresses */\n"
4524 "#define h_addr h_addr_list[0] /* for backward compatibility */\n"
4528 #: build/C/man3/gethostbyname.3:257
4529 msgid "The members of the I<hostent> structure are:"
4533 #: build/C/man3/gethostbyname.3:257 build/C/man3/getipnodebyname.3:210
4539 #: build/C/man3/gethostbyname.3:260
4540 msgid "The official name of the host."
4544 #: build/C/man3/gethostbyname.3:260 build/C/man3/getipnodebyname.3:213
4546 msgid "I<h_aliases>"
4550 #: build/C/man3/gethostbyname.3:263
4551 msgid "An array of alternative names for the host, terminated by a null pointer."
4555 #: build/C/man3/gethostbyname.3:263 build/C/man3/getipnodebyname.3:217
4557 msgid "I<h_addrtype>"
4561 #: build/C/man3/gethostbyname.3:270
4562 msgid "The type of address; always B<AF_INET> or B<AF_INET6> at present."
4566 #: build/C/man3/gethostbyname.3:270 build/C/man3/getipnodebyname.3:239
4572 #: build/C/man3/gethostbyname.3:273
4573 msgid "The length of the address in bytes."
4577 #: build/C/man3/gethostbyname.3:273 build/C/man3/getipnodebyname.3:253
4579 msgid "I<h_addr_list>"
4583 #: build/C/man3/gethostbyname.3:277
4585 "An array of pointers to network addresses for the host (in network byte "
4586 "order), terminated by a null pointer."
4590 #: build/C/man3/gethostbyname.3:277
4596 #: build/C/man3/gethostbyname.3:280
4597 msgid "The first address in I<h_addr_list> for backward compatibility."
4601 #: build/C/man3/gethostbyname.3:292
4603 "The B<gethostbyname>() and B<gethostbyaddr>() functions return the "
4604 "I<hostent> structure or a null pointer if an error occurs. On error, the "
4605 "I<h_errno> variable holds an error number. When non-NULL, the return value "
4606 "may point at static data, see the notes below."
4610 #: build/C/man3/gethostbyname.3:294
4611 msgid "The variable I<h_errno> can have the following values:"
4615 #: build/C/man3/gethostbyname.3:294 build/C/man3/getipnodebyname.3:190
4617 msgid "B<HOST_NOT_FOUND>"
4621 #: build/C/man3/gethostbyname.3:297
4622 msgid "The specified host is unknown."
4626 #: build/C/man3/gethostbyname.3:297
4628 msgid "B<NO_ADDRESS> or B<NO_DATA>"
4632 #: build/C/man3/gethostbyname.3:300
4633 msgid "The requested name is valid but does not have an IP address."
4637 #: build/C/man3/gethostbyname.3:300 build/C/man3/getipnodebyname.3:199
4639 msgid "B<NO_RECOVERY>"
4643 #: build/C/man3/gethostbyname.3:303
4644 msgid "A nonrecoverable name server error occurred."
4648 #: build/C/man3/gethostbyname.3:303 build/C/man3/getipnodebyname.3:202
4650 msgid "B<TRY_AGAIN>"
4654 #: build/C/man3/gethostbyname.3:307
4656 "A temporary error occurred on an authoritative name server. Try again "
4661 #: build/C/man3/gethostbyname.3:308 build/C/man5/host.conf.5:181
4663 msgid "I</etc/host.conf>"
4667 #: build/C/man3/gethostbyname.3:311
4668 msgid "resolver configuration file"
4672 #: build/C/man3/gethostbyname.3:311 build/C/man5/host.conf.5:187 build/C/man5/hosts.5:88
4674 msgid "I</etc/hosts>"
4678 #: build/C/man3/gethostbyname.3:314
4679 msgid "host database file"
4683 #: build/C/man3/gethostbyname.3:314 build/C/man5/nsswitch.conf.5:306 build/C/man3/setnetgrent.3:92
4685 msgid "I</etc/nsswitch.conf>"
4689 #: build/C/man3/gethostbyname.3:317
4690 msgid "name service switch configuration"
4694 #: build/C/man3/gethostbyname.3:341
4696 "POSIX.1-2001 specifies B<gethostbyname>(), B<gethostbyaddr>(), "
4697 "B<sethostent>(), B<endhostent>(), B<gethostent>(), and I<h_errno>; "
4698 "B<gethostbyname>(), B<gethostbyaddr>(), and I<h_errno> are marked "
4699 "obsolescent in that standard. POSIX.1-2008 removes the specifications of "
4700 "B<gethostbyname>(), B<gethostbyaddr>(), and I<h_errno>, recommending the use "
4701 "of B<getaddrinfo>(3) and B<getnameinfo>(3) instead."
4705 #: build/C/man3/gethostbyname.3:351
4707 "The functions B<gethostbyname>() and B<gethostbyaddr>() may return "
4708 "pointers to static data, which may be overwritten by later calls. Copying "
4709 "the I<struct hostent> does not suffice, since it contains pointers; a deep "
4714 #: build/C/man3/gethostbyname.3:375
4716 "In the original BSD implementation the I<len> argument of B<gethostbyname>() "
4717 "was an I<int>. The SUSv2 standard is buggy and declares the I<len> argument "
4718 "of B<gethostbyaddr>() to be of type I<size_t>. (That is wrong, because it "
4719 "has to be I<int>, and I<size_t> is not. POSIX.1-2001 makes it I<socklen_t>, "
4720 "which is OK.) See also B<accept>(2)."
4724 #: build/C/man3/gethostbyname.3:381
4726 "The BSD prototype for B<gethostbyaddr>() uses I<const char\\ *> for the "
4731 #: build/C/man3/gethostbyname.3:381
4733 msgid "System V/POSIX extension"
4736 #. e.g., Linux, FreeBSD, UnixWare, HP-UX
4737 #. e.g., FreeBSD, AIX
4739 #: build/C/man3/gethostbyname.3:398
4741 "POSIX requires the B<gethostent>() call, that should return the next entry "
4742 "in the host data base. When using DNS/BIND this does not make much sense, "
4743 "but it may be reasonable if the host data base is a file that can be read "
4744 "line by line. On many systems a routine of this name reads from the file "
4745 "I</etc/hosts>. It may be available only when the library was built without "
4746 "DNS support. The glibc version will ignore ipv6 entries. This function is "
4747 "not reentrant, and glibc adds a reentrant version B<gethostent_r>()."
4751 #: build/C/man3/gethostbyname.3:398
4753 msgid "GNU extensions"
4757 #: build/C/man3/gethostbyname.3:404
4759 "Glibc2 also has a B<gethostbyname2>() that works like B<gethostbyname>(), "
4760 "but permits to specify the address family to which the address must belong."
4764 #: build/C/man3/gethostbyname.3:438
4766 "Glibc2 also has reentrant versions B<gethostent_r>(), B<gethostbyaddr_r>(), "
4767 "B<gethostbyname_r>() and B<gethostbyname2_r>(). The caller supplies a "
4768 "I<hostent> structure I<ret> which will be filled in on success, and a "
4769 "temporary work buffer I<buf> of size I<buflen>. After the call, I<result> "
4770 "will point to the result on success. In case of an error or if no entry is "
4771 "found I<result> will be NULL. The functions return 0 on success and a "
4772 "nonzero error number on failure. In addition to the errors returned by the "
4773 "nonreentrant versions of these functions, if I<buf> is too small, the "
4774 "functions will return B<ERANGE>, and the call should be retried with a "
4775 "larger buffer. The global variable I<h_errno> is not modified, but the "
4776 "address of a variable in which to store error numbers is passed in "
4780 #. http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=482973
4782 #: build/C/man3/gethostbyname.3:443
4784 "B<gethostbyname>() does not recognize components of a dotted IPv4 address "
4785 "string that are expressed in hexadecimal."
4788 #. .BR getipnodebyaddr (3),
4789 #. .BR getipnodebyname (3),
4791 #: build/C/man3/gethostbyname.3:455
4793 "B<getaddrinfo>(3), B<getnameinfo>(3), B<inet>(3), B<inet_ntop>(3), "
4794 "B<inet_pton>(3), B<resolver>(3), B<hosts>(5), B<nsswitch.conf>(5), "
4795 "B<hostname>(7), B<named>(8)"
4799 #: build/C/man3/getipnodebyname.3:26
4801 msgid "GETIPNODEBYNAME"
4805 #: build/C/man3/getipnodebyname.3:26
4811 #: build/C/man3/getipnodebyname.3:30
4813 "getipnodebyname, getipnodebyaddr, freehostent - get network hostnames and "
4818 #: build/C/man3/getipnodebyname.3:38
4821 "B<struct hostent *getipnodebyname(const char *>I<name>B<, int >I<af>B<,>\n"
4822 "B< int >I<flags>B<, int *>I<error_num>B<);>\n"
4826 #: build/C/man3/getipnodebyname.3:41
4829 "B<struct hostent *getipnodebyaddr(const void *>I<addr>B<, size_t "
4831 "B< int >I<af>B<, int *>I<error_num>B<);>\n"
4835 #: build/C/man3/getipnodebyname.3:43
4837 msgid "B<void freehostent(struct hostent *>I<ip>B<);>\n"
4841 #: build/C/man3/getipnodebyname.3:51
4843 "These functions are deprecated (and unavailable in glibc). Use "
4844 "B<getaddrinfo>(3) and B<getnameinfo>(3) instead."
4848 #: build/C/man3/getipnodebyname.3:59
4850 "The B<getipnodebyname>() and B<getipnodebyaddr>() functions return the "
4851 "names and addresses of a network host. These functions return a pointer to "
4852 "the following structure:"
4856 #: build/C/man3/getipnodebyname.3:69
4859 "struct hostent {\n"
4861 " char **h_aliases;\n"
4862 " int h_addrtype;\n"
4864 " char **h_addr_list;\n"
4869 #: build/C/man3/getipnodebyname.3:82
4871 "These functions replace the B<gethostbyname>(3) and B<gethostbyaddr>(3) "
4872 "functions, which could access only the IPv4 network address family. The "
4873 "B<getipnodebyname>() and B<getipnodebyaddr>() functions can access "
4874 "multiple network address families."
4878 #: build/C/man3/getipnodebyname.3:93
4880 "Unlike the B<gethostby> functions, these functions return pointers to "
4881 "dynamically allocated memory. The B<freehostent>() function is used to "
4882 "release the dynamically allocated memory after the caller no longer needs "
4883 "the I<hostent> structure."
4887 #: build/C/man3/getipnodebyname.3:93
4889 msgid "getipnodebyname() arguments"
4893 #: build/C/man3/getipnodebyname.3:104
4895 "The B<getipnodebyname>() function looks up network addresses for the host "
4896 "specified by the I<name> argument. The I<af> argument specifies one of the "
4901 #: build/C/man3/getipnodebyname.3:104 build/C/man3/getipnodebyname.3:166 build/C/man3/inet_ntop.3:57 build/C/man3/inet_pton.3:53
4907 #: build/C/man3/getipnodebyname.3:110
4909 "The I<name> argument points to a dotted-quad IPv4 address or a name of an "
4910 "IPv4 network host."
4914 #: build/C/man3/getipnodebyname.3:110 build/C/man3/getipnodebyname.3:176 build/C/man3/inet_ntop.3:70 build/C/man3/inet_pton.3:67
4920 #: build/C/man3/getipnodebyname.3:116
4922 "The I<name> argument points to a hexadecimal IPv6 address or a name of an "
4923 "IPv6 network host."
4927 #: build/C/man3/getipnodebyname.3:125
4929 "The I<flags> argument specifies additional options. More than one option "
4930 "can be specified by bitwise OR-ing them together. I<flags> should be set to "
4931 "0 if no options are desired."
4935 #: build/C/man3/getipnodebyname.3:125
4937 msgid "B<AI_V4MAPPED>"
4941 #: build/C/man3/getipnodebyname.3:132
4943 "This flag is used with B<AF_INET6> to request a query for IPv4 addresses "
4944 "instead of IPv6 addresses; the IPv4 addresses will be mapped to IPv6 "
4949 #: build/C/man3/getipnodebyname.3:132
4955 #: build/C/man3/getipnodebyname.3:138
4957 "This flag is used with B<AI_V4MAPPED> to request a query for both IPv4 and "
4958 "IPv6 addresses. Any IPv4 address found will be mapped to an IPv6 address."
4962 #: build/C/man3/getipnodebyname.3:138
4964 msgid "B<AI_ADDRCONFIG>"
4968 #: build/C/man3/getipnodebyname.3:150
4970 "This flag is used with B<AF_INET6> to further request that queries for IPv6 "
4971 "addresses should not be made unless the system has at least one IPv6 address "
4972 "assigned to a network interface, and that queries for IPv4 addresses should "
4973 "not be made unless the system has at least one IPv4 address assigned to a "
4974 "network interface. This flag may be used by itself or with the "
4975 "B<AI_V4MAPPED> flag."
4979 #: build/C/man3/getipnodebyname.3:150
4981 msgid "B<AI_DEFAULT>"
4985 #: build/C/man3/getipnodebyname.3:154
4986 msgid "This flag is equivalent to B<(AI_ADDRCONFIG | AI_V4MAPPED)>."
4990 #: build/C/man3/getipnodebyname.3:154
4992 msgid "getipnodebyaddr() arguments"
4996 #: build/C/man3/getipnodebyname.3:166
4998 "The B<getipnodebyaddr>() function looks up the name of the host whose "
4999 "network address is specified by the I<addr> argument. The I<af> argument "
5000 "specifies one of the following values:"
5004 #: build/C/man3/getipnodebyname.3:176
5006 "The I<addr> argument points to a I<struct in_addr> and I<len> must be set to "
5007 "I<sizeof(struct in_addr)>."
5011 #: build/C/man3/getipnodebyname.3:186
5013 "The I<addr> argument points to a I<struct in6_addr> and I<len> must be set "
5014 "to I<sizeof(struct in6_addr)>."
5018 #: build/C/man3/getipnodebyname.3:190
5020 "NULL is returned if an error occurred, and I<error_num> will contain an "
5021 "error code from the following list:"
5025 #: build/C/man3/getipnodebyname.3:193
5026 msgid "The hostname or network address was not found."
5030 #: build/C/man3/getipnodebyname.3:193
5032 msgid "B<NO_ADDRESS>"
5036 #: build/C/man3/getipnodebyname.3:199
5038 "The domain name server recognized the network address or name, but no answer "
5039 "was returned. This can happen if the network host has only IPv4 addresses "
5040 "and a request has been made for IPv6 information only, or vice versa."
5044 #: build/C/man3/getipnodebyname.3:202
5045 msgid "The domain name server returned a permanent failure response."
5049 #: build/C/man3/getipnodebyname.3:206
5051 "The domain name server returned a temporary failure response. You might "
5052 "have better luck next time."
5056 #: build/C/man3/getipnodebyname.3:210
5058 "A successful query returns a pointer to a I<hostent> structure that contains "
5059 "the following fields:"
5063 #: build/C/man3/getipnodebyname.3:213
5064 msgid "This is the official name of this network host."
5068 #: build/C/man3/getipnodebyname.3:217
5070 "This is an array of pointers to unofficial aliases for the same host. The "
5071 "array is terminated by a null pointer."
5075 #: build/C/man3/getipnodebyname.3:239
5077 "This is a copy of the I<af> argument to B<getipnodebyname>() or "
5078 "B<getipnodebyaddr>(). I<h_addrtype> will always be B<AF_INET> if the I<af> "
5079 "argument was B<AF_INET>. I<h_addrtype> will always be B<AF_INET6> if the "
5080 "I<af> argument was B<AF_INET6>."
5084 #: build/C/man3/getipnodebyname.3:253
5086 "This field will be set to I<sizeof(struct in_addr)> if I<h_addrtype> is "
5087 "B<AF_INET>, and to I<sizeof(struct in6_addr)> if I<h_addrtype> is "
5092 #: build/C/man3/getipnodebyname.3:258
5094 "This is an array of one or more pointers to network address structures for "
5095 "the network host. The array is terminated by a null pointer."
5098 #. Not in POSIX.1-2001.
5100 #: build/C/man3/getipnodebyname.3:261
5105 #: build/C/man3/getipnodebyname.3:266
5107 "These functions were present in glibc 2.1.91-95, but were removed again. "
5108 "Several UNIX-like systems support them, but all call them deprecated."
5112 #: build/C/man3/getipnodebyname.3:270
5113 msgid "B<getaddrinfo>(3), B<getnameinfo>(3), B<inet_ntop>(3), B<inet_pton>(3)"
5117 #: build/C/man3/getnameinfo.3:10
5123 #: build/C/man3/getnameinfo.3:13
5124 msgid "getnameinfo - address-to-name translation in protocol-independent manner"
5128 #: build/C/man3/getnameinfo.3:17
5131 "B<#include E<lt>sys/socket.hE<gt>>\n"
5132 "B<#include E<lt>netdb.hE<gt>>\n"
5136 #: build/C/man3/getnameinfo.3:21
5139 "B<int getnameinfo(const struct sockaddr *>I<sa>B<, socklen_t >I<salen>B<,>\n"
5140 "B< char *>I<host>B<, socklen_t >I<hostlen>B<,>\n"
5141 "B< char *>I<serv>B<, socklen_t >I<servlen>B<, int "
5146 #: build/C/man3/getnameinfo.3:31
5148 "B<getnameinfo>(): _POSIX_C_SOURCE\\ E<gt>=\\ 1 || _XOPEN_SOURCE || "
5153 #: build/C/man3/getnameinfo.3:47
5155 "The B<getnameinfo>() function is the inverse of B<getaddrinfo>(3): it "
5156 "converts a socket address to a corresponding host and service, in a "
5157 "protocol-independent manner. It combines the functionality of "
5158 "B<gethostbyaddr>(3) and B<getservbyport>(3), but unlike those functions, "
5159 "B<getnameinfo>() is reentrant and allows programs to eliminate "
5160 "IPv4-versus-IPv6 dependencies."
5164 #: build/C/man3/getnameinfo.3:70
5166 "The I<sa> argument is a pointer to a generic socket address structure (of "
5167 "type I<sockaddr_in> or I<sockaddr_in6>) of size I<salen> that holds the "
5168 "input IP address and port number. The arguments I<host> and I<serv> are "
5169 "pointers to caller-allocated buffers (of size I<hostlen> and I<servlen> "
5170 "respectively) into which B<getnameinfo>() places null-terminated strings "
5171 "containing the host and service names respectively."
5175 #: build/C/man3/getnameinfo.3:83
5177 "The caller can specify that no hostname (or no service name) is required by "
5178 "providing a NULL I<host> (or I<serv>) argument or a zero I<hostlen> (or "
5179 "I<servlen>) argument. However, at least one of hostname or service name "
5180 "must be requested."
5184 #: build/C/man3/getnameinfo.3:89
5185 msgid "The I<flags> argument modifies the behavior of B<getnameinfo>() as follows:"
5189 #: build/C/man3/getnameinfo.3:89
5191 msgid "B<NI_NAMEREQD>"
5195 #: build/C/man3/getnameinfo.3:92
5196 msgid "If set, then an error is returned if the hostname cannot be determined."
5200 #: build/C/man3/getnameinfo.3:92
5206 #: build/C/man3/getnameinfo.3:98
5208 "If set, then the service is datagram (UDP) based rather than stream (TCP) "
5209 "based. This is required for the few ports (512-514) that have different "
5210 "services for UDP and TCP."
5214 #: build/C/man3/getnameinfo.3:98
5216 msgid "B<NI_NOFQDN>"
5220 #: build/C/man3/getnameinfo.3:102
5222 "If set, return only the hostname part of the fully qualified domain name for "
5227 #: build/C/man3/getnameinfo.3:102
5229 msgid "B<NI_NUMERICHOST>"
5232 #. For example, by calling
5235 #. .BR gethostbyaddr ().
5236 #. POSIX.1-2003 has NI_NUMERICSCOPE, but glibc doesn't have it.
5238 #: build/C/man3/getnameinfo.3:112
5240 "If set, then the numeric form of the hostname is returned. (When not set, "
5241 "this will still happen in case the node's name cannot be determined.)"
5245 #: build/C/man3/getnameinfo.3:112
5247 msgid "B<NI_NUMERICSERV>"
5251 #: build/C/man3/getnameinfo.3:117
5253 "If set, then the numeric form of the service address is returned. (When not "
5254 "set, this will still happen in case the service's name cannot be "
5259 #: build/C/man3/getnameinfo.3:117
5261 msgid "Extensions to getnameinfo() for Internationalized Domain Names"
5265 #: build/C/man3/getnameinfo.3:126
5267 "Starting with glibc 2.3.4, B<getnameinfo>() has been extended to "
5268 "selectively allow hostnames to be transparently converted to and from the "
5269 "Internationalized Domain Name (IDN) format (see RFC 3490, "
5270 "I<Internationalizing Domain Names in Applications (IDNA)>). Three new flags "
5275 #: build/C/man3/getnameinfo.3:126
5281 #: build/C/man3/getnameinfo.3:132
5283 "If this flag is used, then the name found in the lookup process is converted "
5284 "from IDN format to the locale's encoding if necessary. ASCII-only names are "
5285 "not affected by the conversion, which makes this flag usable in existing "
5286 "programs and environments."
5290 #: build/C/man3/getnameinfo.3:132
5292 msgid "B<NI_IDN_ALLOW_UNASSIGNED>, B<NI_IDN_USE_STD3_ASCII_RULES>"
5295 #. FIXME glibc defines the following additional errors, some which
5296 #. can probably be returned by getnameinfo(); they need to
5299 #. #define EAI_INPROGRESS -100 /* Processing request in progress. */
5300 #. #define EAI_CANCELED -101 /* Request canceled. */
5301 #. #define EAI_NOTCANCELED -102 /* Request not canceled. */
5302 #. #define EAI_ALLDONE -103 /* All requests done. */
5303 #. #define EAI_INTR -104 /* Interrupted by a signal. */
5304 #. #define EAI_IDN_ENCODE -105 /* IDN encoding failed. */
5307 #: build/C/man3/getnameinfo.3:155
5309 "On success 0 is returned, and node and service names, if requested, are "
5310 "filled with null-terminated strings, possibly truncated to fit the specified "
5311 "buffer lengths. On error, one of the following nonzero error codes is "
5316 #: build/C/man3/getnameinfo.3:159
5317 msgid "The name could not be resolved at this time. Try again later."
5321 #: build/C/man3/getnameinfo.3:164
5322 msgid "The I<flags> argument has an invalid value."
5326 #: build/C/man3/getnameinfo.3:167
5327 msgid "A nonrecoverable error occurred."
5331 #: build/C/man3/getnameinfo.3:171
5333 "The address family was not recognized, or the address length was invalid for "
5334 "the specified family."
5338 #: build/C/man3/getnameinfo.3:180
5340 "The name does not resolve for the supplied arguments. B<NI_NAMEREQD> is set "
5341 "and the host's name cannot be located, or neither hostname nor service name "
5346 #: build/C/man3/getnameinfo.3:180
5348 msgid "B<EAI_OVERFLOW>"
5352 #: build/C/man3/getnameinfo.3:187
5353 msgid "The buffer pointed to by I<host> or I<serv> was too small."
5357 #: build/C/man3/getnameinfo.3:192
5358 msgid "A system error occurred. The error code can be found in I<errno>."
5362 #: build/C/man3/getnameinfo.3:199
5367 #: build/C/man3/getnameinfo.3:201
5368 msgid "/etc/nsswitch.conf"
5372 #: build/C/man3/getnameinfo.3:203
5373 msgid "/etc/resolv.conf"
5377 #: build/C/man3/getnameinfo.3:206
5378 msgid "B<getnameinfo>() is provided in glibc since version 2.1."
5382 #: build/C/man3/getnameinfo.3:208
5383 msgid "RFC\\ 2553, POSIX.1-2001."
5387 #: build/C/man3/getnameinfo.3:213
5389 "In order to assist the programmer in choosing reasonable sizes for the "
5390 "supplied buffers, I<E<lt>netdb.hE<gt>> defines the constants"
5394 #: build/C/man3/getnameinfo.3:218
5397 "#define NI_MAXHOST 1025\n"
5398 "#define NI_MAXSERV 32\n"
5402 #: build/C/man3/getnameinfo.3:228
5404 "Since glibc 2.8, these definitions are exposed only if one of the feature "
5405 "test macros B<_BSD_SOURCE>, B<_SVID_SOURCE>, or B<_GNU_SOURCE> is defined."
5409 #: build/C/man3/getnameinfo.3:236
5411 "The former is the constant B<MAXDNAME> in recent versions of BIND's "
5412 "I<E<lt>arpa/nameser.hE<gt>> header file. The latter is a guess based on the "
5413 "services listed in the current Assigned Numbers RFC."
5417 #: build/C/man3/getnameinfo.3:243
5419 "Before glibc version 2.2, the I<hostlen> and I<servlen> arguments were typed "
5424 #: build/C/man3/getnameinfo.3:248
5426 "The following code tries to get the numeric hostname and service name, for a "
5427 "given socket address. Note that there is no hardcoded reference to a "
5428 "particular address family."
5432 #: build/C/man3/getnameinfo.3:254
5435 "struct sockaddr *sa; /* input */\n"
5436 "socklen_t len; /* input */\n"
5437 "char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];\n"
5441 #: build/C/man3/getnameinfo.3:258
5444 "if (getnameinfo(sa, len, hbuf, sizeof(hbuf), sbuf,\n"
5445 " sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0)\n"
5446 " printf(\"host=%s, serv=%s\\en\", hbuf, sbuf);\n"
5450 #: build/C/man3/getnameinfo.3:263
5452 "The following version checks if the socket address has a reverse address "
5457 #: build/C/man3/getnameinfo.3:269
5460 "struct sockaddr *sa; /* input */\n"
5461 "socklen_t len; /* input */\n"
5462 "char hbuf[NI_MAXHOST];\n"
5466 #: build/C/man3/getnameinfo.3:275
5469 "if (getnameinfo(sa, len, hbuf, sizeof(hbuf),\n"
5470 " NULL, 0, NI_NAMEREQD))\n"
5471 " printf(\"could not resolve hostname\");\n"
5473 " printf(\"host=%s\\en\", hbuf);\n"
5477 #: build/C/man3/getnameinfo.3:282
5479 "An example program using B<getnameinfo>() can be found in "
5480 "B<getaddrinfo>(3)."
5484 #: build/C/man3/getnameinfo.3:297
5486 "B<accept>(2), B<getpeername>(2), B<getsockname>(2), B<recvfrom>(2), "
5487 "B<socket>(2), B<getaddrinfo>(3), B<gethostbyaddr>(3), B<getservbyname>(3), "
5488 "B<getservbyport>(3), B<inet_ntop>(3), B<hosts>(5), B<services>(5), "
5489 "B<hostname>(7), B<named>(8)"
5493 #: build/C/man3/getnameinfo.3:301
5495 "R. Gilligan, S. Thomson, J. Bound and W. Stevens, I<Basic Socket Interface "
5496 "Extensions for IPv6>, RFC\\ 2553, March 1999."
5500 #: build/C/man3/getnameinfo.3:307
5502 "Tatsuya Jinmei and Atsushi Onoe, I<An Extension of Format for IPv6 Scoped "
5503 "Addresses>, internet draft, work in progress E<.UR "
5504 "ftp://ftp.ietf.org\\:/internet-drafts\\:/draft-ietf-ipngwg-scopedaddr-format-02.txt> "
5509 #: build/C/man3/getnameinfo.3:312
5511 "Craig Metz, I<Protocol Independence Using the Sockets API>, Proceedings of "
5512 "the freenix track: 2000 USENIX annual technical conference, June 2000"
5516 #: build/C/man3/getnameinfo.3:314
5519 "http://www.usenix.org\\:/publications\\:/library\\:/proceedings\\:/usenix2000\\:/freenix\\:/metzprotocol.html> "
5524 #: build/C/man3/getnetent.3:30
5530 #: build/C/man3/getnetent.3:30 build/C/man3/getprotoent.3:30 build/C/man3/getservent.3:34
5536 #: build/C/man3/getnetent.3:34
5538 "getnetent, getnetbyname, getnetbyaddr, setnetent, endnetent - get network "
5543 #: build/C/man3/getnetent.3:37 build/C/man3/getnetent_r.3:33 build/C/man3/getprotoent.3:37 build/C/man3/getprotoent_r.3:33 build/C/man3/getservent.3:41 build/C/man3/getservent_r.3:33 build/C/man3/setnetgrent.3:17
5545 msgid "B<#include E<lt>netdb.hE<gt>>\n"
5549 #: build/C/man3/getnetent.3:39
5551 msgid "B<struct netent *getnetent(void);>\n"
5555 #: build/C/man3/getnetent.3:41
5557 msgid "B<struct netent *getnetbyname(const char *>I<name>B<);>\n"
5561 #: build/C/man3/getnetent.3:43
5563 msgid "B<struct netent *getnetbyaddr(uint32_t >I<net>B<, int >I<type>B<);>\n"
5567 #: build/C/man3/getnetent.3:45
5569 msgid "B<void setnetent(int >I<stayopen>B<);>\n"
5573 #: build/C/man3/getnetent.3:47
5575 msgid "B<void endnetent(void);>\n"
5579 #: build/C/man3/getnetent.3:57
5581 "The B<getnetent>() function reads the next entry from the networks database "
5582 "and returns a I<netent> structure containing the broken-out fields from the "
5583 "entry. A connection is opened to the database if necessary."
5587 #: build/C/man3/getnetent.3:66
5589 "The B<getnetbyname>() function returns a I<netent> structure for the entry "
5590 "from the database that matches the network I<name>."
5594 #: build/C/man3/getnetent.3:80
5596 "The B<getnetbyaddr>() function returns a I<netent> structure for the entry "
5597 "from the database that matches the network number I<net> of type I<type>. "
5598 "The I<net> argument must be in host byte order."
5602 #: build/C/man3/getnetent.3:92
5604 "The B<setnetent>() function opens a connection to the database, and sets "
5605 "the next entry to the first entry. If I<stayopen> is nonzero, then the "
5606 "connection to the database will not be closed between calls to one of the "
5607 "B<getnet*>() functions."
5611 #: build/C/man3/getnetent.3:96
5612 msgid "The B<endnetent>() function closes the connection to the database."
5616 #: build/C/man3/getnetent.3:102
5617 msgid "The I<netent> structure is defined in I<E<lt>netdb.hE<gt>> as follows:"
5621 #: build/C/man3/getnetent.3:111
5625 " char *n_name; /* official network name */\n"
5626 " char **n_aliases; /* alias list */\n"
5627 " int n_addrtype; /* net address type */\n"
5628 " uint32_t n_net; /* network number */\n"
5633 #: build/C/man3/getnetent.3:117
5634 msgid "The members of the I<netent> structure are:"
5638 #: build/C/man3/getnetent.3:117
5644 #: build/C/man3/getnetent.3:120
5645 msgid "The official name of the network."
5649 #: build/C/man3/getnetent.3:120
5651 msgid "I<n_aliases>"
5655 #: build/C/man3/getnetent.3:123
5656 msgid "A NULL-terminated list of alternative names for the network."
5660 #: build/C/man3/getnetent.3:123
5662 msgid "I<n_addrtype>"
5666 #: build/C/man3/getnetent.3:127
5667 msgid "The type of the network number; always B<AF_INET>."
5671 #: build/C/man3/getnetent.3:127
5677 #: build/C/man3/getnetent.3:130
5678 msgid "The network number in host byte order."
5682 #: build/C/man3/getnetent.3:141
5684 "The B<getnetent>(), B<getnetbyname>() and B<getnetbyaddr>() functions "
5685 "return a pointer to a statically allocated I<netent> structure, or a null "
5686 "pointer if an error occurs or the end of the file is reached."
5690 #: build/C/man3/getnetent.3:142 build/C/man5/networks.5:71
5692 msgid "I</etc/networks>"
5696 #: build/C/man3/getnetent.3:145
5697 msgid "networks database file"
5701 #: build/C/man3/getnetent.3:147 build/C/man3/getprotoent.3:142 build/C/man3/getservent.3:159
5702 msgid "4.3BSD, POSIX.1-2001."
5706 #: build/C/man3/getnetent.3:154
5708 "In glibc versions before 2.2, the I<net> argument of B<getnetbyaddr>() was "
5714 #: build/C/man3/getnetent.3:159
5715 msgid "B<getnetent_r>(3), B<getprotoent>(3), B<getservent>(3)"
5719 #: build/C/man3/getnetent.3:160
5724 #: build/C/man3/getnetent_r.3:26
5730 #: build/C/man3/getnetent_r.3:30
5731 msgid "getnetent_r, getnetbyname_r, getnetbyaddr_r - get network entry (reentrant)"
5735 #: build/C/man3/getnetent_r.3:37
5738 "B<int getnetent_r(struct netent *>I<result_buf>B<, char *>I<buf>B<,>\n"
5739 "B< size_t >I<buflen>B<, struct netent **>I<result>B<,>\n"
5740 "B< int *>I<h_errnop>B<);>\n"
5744 #: build/C/man3/getnetent_r.3:42
5747 "B<int getnetbyname_r(const char *>I<name>B<,>\n"
5748 "B< struct netent *>I<result_buf>B<, char *>I<buf>B<,>\n"
5749 "B< size_t >I<buflen>B<, struct netent **>I<result>B<,>\n"
5750 "B< int *>I<h_errnop>B<);>\n"
5754 #: build/C/man3/getnetent_r.3:47
5757 "B<int getnetbyaddr_r(uint32_t >I<net>B<, int >I<type>B<,>\n"
5758 "B< struct netent *>I<result_buf>B<, char *>I<buf>B<,>\n"
5759 "B< size_t >I<buflen>B<, struct netent **>I<result>B<,>\n"
5760 "B< int *>I<h_errnop>B<);>\n"
5764 #: build/C/man3/getnetent_r.3:58
5765 msgid "B<getnetent_r>(), B<getnetbyname_r>(), B<getnetbyaddr_r>():"
5769 #: build/C/man3/getnetent_r.3:79
5771 "The B<getnetent_r>(), B<getnetbyname_r>(), and B<getnetbyaddr_r>() "
5772 "functions are the reentrant equivalents of, respectively, B<getnetent>(3), "
5773 "B<getnetbyname>(3), and B<getnetbynumber>(3). They differ in the way that "
5774 "the I<netent> structure is returned, and in the function calling signature "
5775 "and return value. This manual page describes just the differences from the "
5776 "nonreentrant functions."
5780 #: build/C/man3/getnetent_r.3:85
5782 "Instead of returning a pointer to a statically allocated I<netent> structure "
5783 "as the function result, these functions copy the structure into the location "
5784 "pointed to by I<result_buf>."
5787 #. I can find no information on the required/recommended buffer size;
5788 #. the nonreentrant functions use a 1024 byte buffer -- mtk.
5790 #: build/C/man3/getnetent_r.3:102
5792 "The I<buf> array is used to store the string fields pointed to by the "
5793 "returned I<netent> structure. (The nonreentrant functions allocate these "
5794 "strings in static storage.) The size of this array is specified in "
5795 "I<buflen>. If I<buf> is too small, the call fails with the error B<ERANGE>, "
5796 "and the caller must try again with a larger buffer. (A buffer of length "
5797 "1024 bytes should be sufficient for most applications.)"
5801 #: build/C/man3/getnetent_r.3:110
5803 "If the function call successfully obtains a network record, then I<*result> "
5804 "is set pointing to I<result_buf>; otherwise, I<*result> is set to NULL."
5807 #. getnetent.3 doesn't document any use of h_errno, but nevertheless
5808 #. the nonreentrant functions no seem to set h_errno.
5810 #: build/C/man3/getnetent_r.3:118
5812 "The buffer pointed to by I<h_errnop> is used to return the value that would "
5813 "be stored in the global variable I<h_errno> by the nonreentrant versions of "
5818 #: build/C/man3/getnetent_r.3:121 build/C/man3/getprotoent_r.3:111
5820 "On success, these functions return 0. On error, they return one of the "
5821 "positive error numbers listed in ERRORS."
5825 #: build/C/man3/getnetent_r.3:129
5827 "On error, record not found (B<getnetbyname_r>(), B<getnetbyaddr_r>()), or "
5828 "end of input (B<getnetent_r>()) I<result> is set to NULL."
5832 #: build/C/man3/getnetent_r.3:134
5833 msgid "(B<getnetent_r>()) No more records in database."
5837 #: build/C/man3/getnetent_r.3:134 build/C/man3/getprotoent_r.3:124 build/C/man3/getservent_r.3:123
5843 #: build/C/man3/getnetent_r.3:141 build/C/man3/getprotoent_r.3:131 build/C/man3/getservent_r.3:130
5845 "I<buf> is too small. Try again with a larger buffer (and increased "
5850 #: build/C/man3/getnetent_r.3:145 build/C/man3/getprotoent_r.3:135 build/C/man3/getservent_r.3:134
5852 "These functions are GNU extensions. Functions with similar names exist on "
5853 "some other systems, though typically with different calling signatures."
5857 #: build/C/man3/getnetent_r.3:147
5858 msgid "B<getnetent>(3), B<networks>(5)"
5862 #: build/C/man2/getpeername.2:42
5868 #: build/C/man2/getpeername.2:42 build/C/man5/nsswitch.conf.5:25
5874 #: build/C/man2/getpeername.2:45
5875 msgid "getpeername - get name of connected peer socket"
5879 #: build/C/man2/getpeername.2:50
5881 "B<int getpeername(int >I<sockfd>B<, struct sockaddr *>I<addr>B<, socklen_t "
5886 #: build/C/man2/getpeername.2:63
5888 "B<getpeername>() returns the address of the peer connected to the socket "
5889 "I<sockfd>, in the buffer pointed to by I<addr>. The I<addrlen> argument "
5890 "should be initialized to indicate the amount of space pointed to by "
5891 "I<addr>. On return it contains the actual size of the name returned (in "
5892 "bytes). The name is truncated if the buffer provided is too small."
5896 #: build/C/man2/getpeername.2:68
5898 "The returned address is truncated if the buffer provided is too small; in "
5899 "this case, I<addrlen> will return a value greater than was supplied to the "
5904 #: build/C/man2/getpeername.2:73 build/C/man2/shutdown.2:74
5906 "On success, zero is returned. On error, -1 is returned, and I<errno> is set "
5911 #: build/C/man2/getpeername.2:74 build/C/man2/shutdown.2:75
5917 #: build/C/man2/getpeername.2:79
5918 msgid "The argument I<sockfd> is not a valid descriptor."
5922 #: build/C/man2/getpeername.2:79 build/C/man7/packet.7:500 build/C/man7/raw.7:149 build/C/man7/unix.7:419
5928 #: build/C/man2/getpeername.2:85
5930 "The I<addr> argument points to memory not in a valid part of the process "
5935 #: build/C/man2/getpeername.2:89
5936 msgid "I<addrlen> is invalid (e.g., is negative)."
5940 #: build/C/man2/getpeername.2:89 build/C/man7/packet.7:512
5946 #: build/C/man2/getpeername.2:93
5948 "Insufficient resources were available in the system to perform the "
5953 #: build/C/man2/getpeername.2:96
5954 msgid "The socket is not connected."
5958 #: build/C/man2/getpeername.2:96 build/C/man2/shutdown.2:87
5964 #: build/C/man2/getpeername.2:101
5965 msgid "The argument I<sockfd> is a file, not a socket."
5969 #: build/C/man2/getpeername.2:105
5971 "SVr4, 4.4BSD (the B<getpeername>() function call first appeared in 4.2BSD), "
5976 #: build/C/man2/getpeername.2:116
5978 "The third argument of B<getpeername>() is in reality an I<int\\ *> (and "
5979 "this is what 4.x BSD and libc4 and libc5 have). Some POSIX confusion "
5980 "resulted in the present I<socklen_t>, also used by glibc. See also "
5985 #: build/C/man2/getpeername.2:143
5987 "For stream sockets, once a B<connect>(2) has been performed, either socket "
5988 "can call B<getpeername>() to obtain the address of the peer socket. On the "
5989 "other hand, datagram sockets are connectionless. Calling B<connect>(2) on "
5990 "a datagram socket merely sets the peer address for outgoing datagrams sent "
5991 "with B<write>(2) or B<recv>(2). The caller of B<connect>(2) can use "
5992 "B<getpeername>() to obtain the peer address that it earlier set for the "
5993 "socket. However, the peer socket is unaware of this information, and "
5994 "calling B<getpeername>() on the peer socket will return no useful "
5995 "information (unless a B<connect>(2) call was also executed on the peer). "
5996 "Note also that the receiver of a datagram can obtain the address of the "
5997 "sender when using B<recvfrom>(2)."
6001 #: build/C/man2/getpeername.2:149
6003 "B<accept>(2), B<bind>(2), B<getsockname>(2), B<ip>(7), B<socket>(7), "
6008 #: build/C/man3/getprotoent.3:30
6014 #: build/C/man3/getprotoent.3:34
6016 "getprotoent, getprotobyname, getprotobynumber, setprotoent, endprotoent - "
6017 "get protocol entry"
6021 #: build/C/man3/getprotoent.3:39
6023 msgid "B<struct protoent *getprotoent(void);>\n"
6027 #: build/C/man3/getprotoent.3:41
6029 msgid "B<struct protoent *getprotobyname(const char *>I<name>B<);>\n"
6033 #: build/C/man3/getprotoent.3:43
6035 msgid "B<struct protoent *getprotobynumber(int >I<proto>B<);>\n"
6039 #: build/C/man3/getprotoent.3:45
6041 msgid "B<void setprotoent(int >I<stayopen>B<);>\n"
6045 #: build/C/man3/getprotoent.3:47
6047 msgid "B<void endprotoent(void);>\n"
6051 #: build/C/man3/getprotoent.3:58
6053 "The B<getprotoent>() function reads the next entry from the protocols "
6054 "database (see B<protocols>(5)) and returns a I<protoent> structure "
6055 "containing the broken-out fields from the entry. A connection is opened to "
6056 "the database if necessary."
6060 #: build/C/man3/getprotoent.3:68
6062 "The B<getprotobyname>() function returns a I<protoent> structure for the "
6063 "entry from the database that matches the protocol name I<name>. A "
6064 "connection is opened to the database if necessary."
6068 #: build/C/man3/getprotoent.3:78
6070 "The B<getprotobynumber>() function returns a I<protoent> structure for the "
6071 "entry from the database that matches the protocol number I<number>. A "
6072 "connection is opened to the database if necessary."
6076 #: build/C/man3/getprotoent.3:90
6078 "The B<setprotoent>() function opens a connection to the database, and sets "
6079 "the next entry to the first entry. If I<stayopen> is nonzero, then the "
6080 "connection to the database will not be closed between calls to one of the "
6081 "B<getproto*>() functions."
6085 #: build/C/man3/getprotoent.3:94
6086 msgid "The B<endprotoent>() function closes the connection to the database."
6090 #: build/C/man3/getprotoent.3:100
6091 msgid "The I<protoent> structure is defined in I<E<lt>netdb.hE<gt>> as follows:"
6095 #: build/C/man3/getprotoent.3:108
6098 "struct protoent {\n"
6099 " char *p_name; /* official protocol name */\n"
6100 " char **p_aliases; /* alias list */\n"
6101 " int p_proto; /* protocol number */\n"
6106 #: build/C/man3/getprotoent.3:114
6107 msgid "The members of the I<protoent> structure are:"
6111 #: build/C/man3/getprotoent.3:114
6117 #: build/C/man3/getprotoent.3:117
6118 msgid "The official name of the protocol."
6122 #: build/C/man3/getprotoent.3:117
6124 msgid "I<p_aliases>"
6128 #: build/C/man3/getprotoent.3:120
6129 msgid "A NULL-terminated list of alternative names for the protocol."
6133 #: build/C/man3/getprotoent.3:120
6139 #: build/C/man3/getprotoent.3:123
6140 msgid "The protocol number."
6144 #: build/C/man3/getprotoent.3:134
6146 "The B<getprotoent>(), B<getprotobyname>() and B<getprotobynumber>() "
6147 "functions return a pointer to a statically allocated I<protoent> structure, "
6148 "or a null pointer if an error occurs or the end of the file is reached."
6152 #: build/C/man3/getprotoent.3:136 build/C/man5/protocols.5:78
6154 msgid "I</etc/protocols>"
6158 #: build/C/man3/getprotoent.3:139
6159 msgid "protocol database file"
6163 #: build/C/man3/getprotoent.3:146
6164 msgid "B<getnetent>(3), B<getprotoent_r>(3), B<getservent>(3), B<protocols>(5)"
6168 #: build/C/man3/getprotoent_r.3:26
6170 msgid "GETPROTOENT_R"
6174 #: build/C/man3/getprotoent_r.3:30
6176 "getprotoent_r, getprotobyname_r, getprotobynumber_r - get protocol entry "
6181 #: build/C/man3/getprotoent_r.3:36
6184 "B<int getprotoent_r(struct protoent *>I<result_buf>B<, char *>I<buf>B<,>\n"
6185 "B< size_t >I<buflen>B<, struct protoent **>I<result>B<);>\n"
6189 #: build/C/man3/getprotoent_r.3:40
6192 "B<int getprotobyname_r(const char *>I<name>B<,>\n"
6193 "B< struct protoent *>I<result_buf>B<, char *>I<buf>B<,>\n"
6194 "B< size_t >I<buflen>B<, struct protoent **>I<result>B<);>\n"
6198 #: build/C/man3/getprotoent_r.3:44
6201 "B<int getprotobynumber_r(int >I<proto>B<,>\n"
6202 "B< struct protoent *>I<result_buf>B<, char *>I<buf>B<,>\n"
6203 "B< size_t >I<buflen>B<, struct protoent **>I<result>B<);>\n"
6207 #: build/C/man3/getprotoent_r.3:55
6208 msgid "B<getprotoent_r>(), B<getprotobyname_r>(), B<getprotobynumber_r>():"
6212 #: build/C/man3/getprotoent_r.3:76
6214 "The B<getprotoent_r>(), B<getprotobyname_r>(), and B<getprotobynumber_r>() "
6215 "functions are the reentrant equivalents of, respectively, B<getprotoent>(3), "
6216 "B<getprotobyname>(3), and B<getprotobynumber>(3). They differ in the way "
6217 "that the I<protoent> structure is returned, and in the function calling "
6218 "signature and return value. This manual page describes just the differences "
6219 "from the nonreentrant functions."
6223 #: build/C/man3/getprotoent_r.3:82
6225 "Instead of returning a pointer to a statically allocated I<protoent> "
6226 "structure as the function result, these functions copy the structure into "
6227 "the location pointed to by I<result_buf>."
6230 #. I can find no information on the required/recommended buffer size;
6231 #. the nonreentrant functions use a 1024 byte buffer.
6232 #. The 1024 byte value is also what the Solaris man page suggests. -- mtk
6234 #: build/C/man3/getprotoent_r.3:100
6236 "The I<buf> array is used to store the string fields pointed to by the "
6237 "returned I<protoent> structure. (The nonreentrant functions allocate these "
6238 "strings in static storage.) The size of this array is specified in "
6239 "I<buflen>. If I<buf> is too small, the call fails with the error B<ERANGE>, "
6240 "and the caller must try again with a larger buffer. (A buffer of length "
6241 "1024 bytes should be sufficient for most applications.)"
6245 #: build/C/man3/getprotoent_r.3:108
6247 "If the function call successfully obtains a protocol record, then I<*result> "
6248 "is set pointing to I<result_buf>; otherwise, I<*result> is set to NULL."
6252 #: build/C/man3/getprotoent_r.3:119
6254 "On error, record not found (B<getprotobyname_r>(), B<getprotobynumber_r>()), "
6255 "or end of input (B<getprotoent_r>()) I<result> is set to NULL."
6259 #: build/C/man3/getprotoent_r.3:124
6260 msgid "(B<getprotoent_r>()) No more records in database."
6264 #: build/C/man3/getprotoent_r.3:149
6266 "The program below uses B<getprotobyname_r>() to retrieve the protocol "
6267 "record for the protocol named in its first command-line argument. If a "
6268 "second (integer) command-line argument is supplied, it is used as the "
6269 "initial value for I<buflen>; if B<getprotobyname_r>() fails with the error "
6270 "B<ERANGE>, the program retries with larger buffer sizes. The following "
6271 "shell session shows a couple of sample runs:"
6275 #: build/C/man3/getprotoent_r.3:160
6278 "$B< ./a.out tcp 1>\n"
6279 "ERANGE! Retrying with larger buffer\n"
6280 "getprotobyname_r() returned: 0 (success) (buflen=78)\n"
6281 "p_name=tcp; p_proto=6; aliases=TCP\n"
6282 "$B< ./a.out xxx 1>\n"
6283 "ERANGE! Retrying with larger buffer\n"
6284 "getprotobyname_r() returned: 0 (success) (buflen=100)\n"
6285 "Call failed/record not found\n"
6289 #: build/C/man3/getprotoent_r.3:172 build/C/man3/getservent_r.3:170
6292 "#define _GNU_SOURCE\n"
6293 "#include E<lt>ctype.hE<gt>\n"
6294 "#include E<lt>netdb.hE<gt>\n"
6295 "#include E<lt>stdlib.hE<gt>\n"
6296 "#include E<lt>stdio.hE<gt>\n"
6297 "#include E<lt>errno.hE<gt>\n"
6298 "#include E<lt>string.hE<gt>\n"
6302 #: build/C/man3/getprotoent_r.3:174 build/C/man3/getservent_r.3:172
6304 msgid "#define MAX_BUF 10000\n"
6308 #: build/C/man3/getprotoent_r.3:183
6312 "main(int argc, char *argv[])\n"
6314 " int buflen, erange_cnt, s;\n"
6315 " struct protoent result_buf;\n"
6316 " struct protoent *result;\n"
6317 " char buf[MAX_BUF];\n"
6322 #: build/C/man3/getprotoent_r.3:188
6325 " if (argc E<lt> 2) {\n"
6326 " printf(\"Usage: %s proto-name [buflen]\\en\", argv[0]);\n"
6327 " exit(EXIT_FAILURE);\n"
6332 #: build/C/man3/getprotoent_r.3:192
6336 " if (argc E<gt> 2)\n"
6337 " buflen = atoi(argv[2]);\n"
6341 #: build/C/man3/getprotoent_r.3:197 build/C/man3/getservent_r.3:200
6344 " if (buflen E<gt> MAX_BUF) {\n"
6345 " printf(\"Exceeded buffer limit (%d)\\en\", MAX_BUF);\n"
6346 " exit(EXIT_FAILURE);\n"
6351 #: build/C/man3/getprotoent_r.3:206
6354 " erange_cnt = 0;\n"
6356 " s = getprotobyname_r(argv[1], &result_buf,\n"
6357 " buf, buflen, &result);\n"
6358 " if (s == ERANGE) {\n"
6359 " if (erange_cnt == 0)\n"
6360 " printf(\"ERANGE! Retrying with larger buffer\\en\");\n"
6365 #: build/C/man3/getprotoent_r.3:209 build/C/man3/getservent_r.3:212
6368 " /* Increment a byte at a time so we can see exactly\n"
6369 " what size buffer was required */\n"
6373 #: build/C/man3/getprotoent_r.3:211 build/C/man3/getservent_r.3:214
6375 msgid " buflen++;\n"
6379 #: build/C/man3/getprotoent_r.3:218 build/C/man3/getservent_r.3:221
6382 " if (buflen E<gt> MAX_BUF) {\n"
6383 " printf(\"Exceeded buffer limit (%d)\\en\", MAX_BUF);\n"
6384 " exit(EXIT_FAILURE);\n"
6387 " } while (s == ERANGE);\n"
6391 #: build/C/man3/getprotoent_r.3:222
6394 " printf(\"getprotobyname_r() returned: %s (buflen=%d)\\en\",\n"
6395 " (s == 0) ? \"0 (success)\" : (s == ENOENT) ? \"ENOENT\" :\n"
6396 " strerror(s), buflen);\n"
6400 #: build/C/man3/getprotoent_r.3:227 build/C/man3/getservent_r.3:230
6403 " if (s != 0 || result == NULL) {\n"
6404 " printf(\"Call failed/record not found\\en\");\n"
6405 " exit(EXIT_FAILURE);\n"
6410 #: build/C/man3/getprotoent_r.3:233
6413 " printf(\"p_name=%s; p_proto=%d; aliases=\",\n"
6414 " result_buf.p_name, result_buf.p_proto);\n"
6415 " for (p = result_buf.p_aliases; *p != NULL; p++)\n"
6416 " printf(\"%s \", *p);\n"
6417 " printf(\"\\en\");\n"
6421 #: build/C/man3/getprotoent_r.3:239
6422 msgid "B<getprotoent>(3), B<protocols>(5)"
6426 #: build/C/man3/getservent.3:34
6432 #: build/C/man3/getservent.3:38
6434 "getservent, getservbyname, getservbyport, setservent, endservent - get "
6439 #: build/C/man3/getservent.3:43
6441 msgid "B<struct servent *getservent(void);>\n"
6445 #: build/C/man3/getservent.3:45
6448 "B<struct servent *getservbyname(const char *>I<name>B<, const char "
6453 #: build/C/man3/getservent.3:47
6455 msgid "B<struct servent *getservbyport(int >I<port>B<, const char *>I<proto>B<);>\n"
6459 #: build/C/man3/getservent.3:49
6461 msgid "B<void setservent(int >I<stayopen>B<);>\n"
6465 #: build/C/man3/getservent.3:51
6467 msgid "B<void endservent(void);>\n"
6471 #: build/C/man3/getservent.3:62
6473 "The B<getservent>() function reads the next entry from the services "
6474 "database (see B<services>(5)) and returns a I<servent> structure containing "
6475 "the broken-out fields from the entry. A connection is opened to the "
6476 "database if necessary."
6480 #: build/C/man3/getservent.3:77
6482 "The B<getservbyname>() function returns a I<servent> structure for the "
6483 "entry from the database that matches the service I<name> using protocol "
6484 "I<proto>. If I<proto> is NULL, any protocol will be matched. A connection "
6485 "is opened to the database if necessary."
6489 #: build/C/man3/getservent.3:93
6491 "The B<getservbyport>() function returns a I<servent> structure for the "
6492 "entry from the database that matches the port I<port> (given in network byte "
6493 "order) using protocol I<proto>. If I<proto> is NULL, any protocol will be "
6494 "matched. A connection is opened to the database if necessary."
6498 #: build/C/man3/getservent.3:105
6500 "The B<setservent>() function opens a connection to the database, and sets "
6501 "the next entry to the first entry. If I<stayopen> is nonzero, then the "
6502 "connection to the database will not be closed between calls to one of the "
6503 "B<getserv*>() functions."
6507 #: build/C/man3/getservent.3:109
6508 msgid "The B<endservent>() function closes the connection to the database."
6512 #: build/C/man3/getservent.3:115
6513 msgid "The I<servent> structure is defined in I<E<lt>netdb.hE<gt>> as follows:"
6517 #: build/C/man3/getservent.3:124
6520 "struct servent {\n"
6521 " char *s_name; /* official service name */\n"
6522 " char **s_aliases; /* alias list */\n"
6523 " int s_port; /* port number */\n"
6524 " char *s_proto; /* protocol to use */\n"
6529 #: build/C/man3/getservent.3:130
6530 msgid "The members of the I<servent> structure are:"
6534 #: build/C/man3/getservent.3:130
6540 #: build/C/man3/getservent.3:133
6541 msgid "The official name of the service."
6545 #: build/C/man3/getservent.3:133
6547 msgid "I<s_aliases>"
6551 #: build/C/man3/getservent.3:136
6552 msgid "A NULL-terminated list of alternative names for the service."
6556 #: build/C/man3/getservent.3:136
6562 #: build/C/man3/getservent.3:139
6563 msgid "The port number for the service given in network byte order."
6567 #: build/C/man3/getservent.3:139
6573 #: build/C/man3/getservent.3:142
6574 msgid "The name of the protocol to use with this service."
6578 #: build/C/man3/getservent.3:153
6580 "The B<getservent>(), B<getservbyname>() and B<getservbyport>() functions "
6581 "return a pointer to a statically allocated I<servent> structure, or NULL if "
6582 "an error occurs or the end of the file is reached."
6586 #: build/C/man3/getservent.3:154 build/C/man5/services.5:186
6588 msgid "I</etc/services>"
6592 #: build/C/man3/getservent.3:157
6593 msgid "services database file"
6597 #: build/C/man3/getservent.3:163
6598 msgid "B<getnetent>(3), B<getprotoent>(3), B<getservent_r>(3), B<services>(5)"
6602 #: build/C/man3/getservent_r.3:26
6604 msgid "GETSERVENT_R"
6608 #: build/C/man3/getservent_r.3:30
6610 "getservent_r, getservbyname_r, getservbyport_r - get service entry "
6615 #: build/C/man3/getservent_r.3:36
6618 "B<int getservent_r(struct servent *>I<result_buf>B<, char *>I<buf>B<,>\n"
6619 "B< size_t >I<buflen>B<, struct servent **>I<result>B<);>\n"
6623 #: build/C/man3/getservent_r.3:40
6626 "B<int getservbyname_r(const char *>I<name>B<, const char *>I<proto>B<,>\n"
6627 "B< struct servent *>I<result_buf>B<, char *>I<buf>B<,>\n"
6628 "B< size_t >I<buflen>B<, struct servent **>I<result>B<);>\n"
6632 #: build/C/man3/getservent_r.3:44
6635 "B<int getservbyport_r(int >I<port>B<, const char *>I<proto>B<,>\n"
6636 "B< struct servent *>I<result_buf>B<, char *>I<buf>B<,>\n"
6637 "B< size_t >I<buflen>B<, struct servent **>I<result>B<);>\n"
6641 #: build/C/man3/getservent_r.3:55
6642 msgid "B<getservent_r>(), B<getservbyname_r>(), B<getservbyport_r>():"
6646 #: build/C/man3/getservent_r.3:76
6648 "The B<getservent_r>(), B<getservbyname_r>(), and B<getservbyport_r>() "
6649 "functions are the reentrant equivalents of, respectively, B<getservent>(3), "
6650 "B<getservbyname>(3), and B<getservbyport>(3). They differ in the way that "
6651 "the I<servent> structure is returned, and in the function calling signature "
6652 "and return value. This manual page describes just the differences from the "
6653 "nonreentrant functions."
6657 #: build/C/man3/getservent_r.3:82
6659 "Instead of returning a pointer to a statically allocated I<servent> "
6660 "structure as the function result, these functions copy the structure into "
6661 "the location pointed to by I<result_buf>."
6664 #. I can find no information on the required/recommended buffer size;
6665 #. the nonreentrant functions use a 1024 byte buffer -- mtk.
6667 #: build/C/man3/getservent_r.3:99
6669 "The I<buf> array is used to store the string fields pointed to by the "
6670 "returned I<servent> structure. (The nonreentrant functions allocate these "
6671 "strings in static storage.) The size of this array is specified in "
6672 "I<buflen>. If I<buf> is too small, the call fails with the error B<ERANGE>, "
6673 "and the caller must try again with a larger buffer. (A buffer of length "
6674 "1024 bytes should be sufficient for most applications.)"
6678 #: build/C/man3/getservent_r.3:107
6680 "If the function call successfully obtains a service record, then I<*result> "
6681 "is set pointing to I<result_buf>; otherwise, I<*result> is set to NULL."
6685 #: build/C/man3/getservent_r.3:110
6687 "On success, these functions return 0. On error, they return one of the "
6688 "positive error numbers listed in errors."
6692 #: build/C/man3/getservent_r.3:118
6694 "On error, record not found (B<getservbyname_r>(), B<getservbyport_r>()), or "
6695 "end of input (B<getservent_r>()) I<result> is set to NULL."
6699 #: build/C/man3/getservent_r.3:123
6700 msgid "(B<getservent_r>()) No more records in database."
6704 #: build/C/man3/getservent_r.3:148
6706 "The program below uses B<getservbyport_r>() to retrieve the service record "
6707 "for the port and protocol named in its first command-line argument. If a "
6708 "third (integer) command-line argument is supplied, it is used as the initial "
6709 "value for I<buflen>; if B<getservbyport_r>() fails with the error "
6710 "B<ERANGE>, the program retries with larger buffer sizes. The following "
6711 "shell session shows a couple of sample runs:"
6715 #: build/C/man3/getservent_r.3:158
6718 "$B< ./a.out 7 tcp 1>\n"
6719 "ERANGE! Retrying with larger buffer\n"
6720 "getservbyport_r() returned: 0 (success) (buflen=87)\n"
6721 "s_name=echo; s_proto=tcp; s_port=7; aliases=\n"
6722 "$B< ./a.out 77777 tcp>\n"
6723 "getservbyport_r() returned: 0 (success) (buflen=1024)\n"
6724 "Call failed/record not found\n"
6728 #: build/C/man3/getservent_r.3:182
6732 "main(int argc, char *argv[])\n"
6734 " int buflen, erange_cnt, port, s;\n"
6735 " struct servent result_buf;\n"
6736 " struct servent *result;\n"
6737 " char buf[MAX_BUF];\n"
6743 #: build/C/man3/getservent_r.3:187
6746 " if (argc E<lt> 3) {\n"
6747 " printf(\"Usage: %s port-num proto-name [buflen]\\en\", argv[0]);\n"
6748 " exit(EXIT_FAILURE);\n"
6753 #: build/C/man3/getservent_r.3:191
6756 " port = htons(atoi(argv[1]));\n"
6757 " protop = (strcmp(argv[2], \"null\") == 0 ||\n"
6758 " strcmp(argv[2], \"NULL\") == 0) ? NULL : argv[2];\n"
6762 #: build/C/man3/getservent_r.3:195
6766 " if (argc E<gt> 3)\n"
6767 " buflen = atoi(argv[3]);\n"
6771 #: build/C/man3/getservent_r.3:209
6774 " erange_cnt = 0;\n"
6776 " s = getservbyport_r(port, protop, &result_buf,\n"
6777 " buf, buflen, &result);\n"
6778 " if (s == ERANGE) {\n"
6779 " if (erange_cnt == 0)\n"
6780 " printf(\"ERANGE! Retrying with larger buffer\\en\");\n"
6785 #: build/C/man3/getservent_r.3:225
6788 " printf(\"getservbyport_r() returned: %s (buflen=%d)\\en\",\n"
6789 " (s == 0) ? \"0 (success)\" : (s == ENOENT) ? \"ENOENT\" :\n"
6790 " strerror(s), buflen);\n"
6794 #: build/C/man3/getservent_r.3:237
6797 " printf(\"s_name=%s; s_proto=%s; s_port=%d; aliases=\",\n"
6798 " result_buf.s_name, result_buf.s_proto,\n"
6799 " ntohs(result_buf.s_port));\n"
6800 " for (p = result_buf.s_aliases; *p != NULL; p++)\n"
6801 " printf(\"%s \", *p);\n"
6802 " printf(\"\\en\");\n"
6806 #: build/C/man3/getservent_r.3:243
6807 msgid "B<getservent>(3), B<services>(5)"
6811 #: build/C/man5/host.conf.5:26
6817 #: build/C/man5/host.conf.5:26
6823 #: build/C/man5/host.conf.5:26 build/C/man5/networks.5:26
6825 msgid "Linux System Administration"
6829 #: build/C/man5/host.conf.5:29
6830 msgid "host.conf - resolver configuration file"
6834 #: build/C/man5/host.conf.5:38
6836 "The file I</etc/host.conf> contains configuration information specific to "
6837 "the resolver library. It should contain one configuration keyword per line, "
6838 "followed by appropriate configuration information. The keywords recognized "
6839 "are I<order>, I<trim>, I<multi>, I<nospoof>, I<spoof>, and I<reorder>. "
6840 "These keywords are described below."
6844 #: build/C/man5/host.conf.5:38
6850 #: build/C/man5/host.conf.5:44
6852 "This keyword specifies how host lookups are to be performed. It should be "
6853 "followed by one or more lookup methods, separated by commas. Valid methods "
6854 "are I<bind>, I<hosts>, and I<nis>."
6858 #: build/C/man5/host.conf.5:44
6864 #: build/C/man5/host.conf.5:61
6866 "This keyword may be listed more than once. Each time it should be followed "
6867 "by a list of domains, separated by colons (\\(aq:\\(aq), semicolons "
6868 "(\\(aq;\\(aq) or commas (\\(aq,\\(aq), with the leading dot. When set, the "
6869 "resolv+ library will automatically trim the given domain name from the end "
6870 "of any hostname resolved via DNS. This is intended for use with local hosts "
6871 "and domains. (Related note: trim will not affect hostnames gathered via NIS "
6872 "or the hosts file. Care should be taken to ensure that the first hostname "
6873 "for each entry in the hosts file is fully qualified or unqualified, as "
6874 "appropriate for the local installation.)"
6878 #: build/C/man5/host.conf.5:61
6884 #: build/C/man5/host.conf.5:76
6886 "Valid values are I<on> and I<off>. If set to I<on>, the resolv+ library "
6887 "will return all valid addresses for a host that appears in the I</etc/hosts> "
6888 "file, instead of only the first. This is I<off> by default, as it may cause "
6889 "a substantial performance loss at sites with large hosts files."
6893 #: build/C/man5/host.conf.5:76
6899 #: build/C/man5/host.conf.5:91
6901 "Valid values are I<on> and I<off>. If set to I<on>, the resolv+ library "
6902 "will attempt to prevent hostname spoofing to enhance the security of "
6903 "B<rlogin> and B<rsh>. It works as follows: after performing a host address "
6904 "lookup, resolv+ will perform a hostname lookup for that address. If the two "
6905 "hostnames do not match, the query will fail. The default value is I<off>."
6909 #: build/C/man5/host.conf.5:91
6911 msgid "I<spoofalert>"
6915 #: build/C/man5/host.conf.5:103
6917 "Valid values are I<on> and I<off>. If this option is set to I<on> and the "
6918 "I<nospoof> option is also set, resolv+ will log a warning of the error via "
6919 "the syslog facility. The default value is I<off>."
6923 #: build/C/man5/host.conf.5:103
6929 #: build/C/man5/host.conf.5:122
6931 "Valid values are I<off>, I<nowarn> and I<warn>. If this option is set to "
6932 "I<off>, spoofed addresses are permitted and no warnings will be emitted via "
6933 "the syslog facility. If this option is set to I<warn>, resolv+ will attempt "
6934 "to prevent hostname spoofing to enhance the security and log a warning of "
6935 "the error via the syslog facility. If this option is set to I<nowarn>, the "
6936 "resolv+ library will attempt to prevent hostname spoofing to enhance the "
6937 "security but not emit warnings via the syslog facility. Setting this option "
6938 "to anything else is equal to setting it to I<nowarn>."
6942 #: build/C/man5/host.conf.5:122
6948 #: build/C/man5/host.conf.5:135
6950 "Valid values are I<on> and I<off>. If set to I<on>, resolv+ will attempt to "
6951 "reorder host addresses so that local addresses (i.e., on the same subnet) "
6952 "are listed first when a B<gethostbyname>(3) is performed. Reordering is "
6953 "done for all lookup methods. The default value is I<off>."
6957 #: build/C/man5/host.conf.5:135
6963 #: build/C/man5/host.conf.5:139
6965 "There are six environment variables that can be used to allow users to "
6966 "override the behavior which is configured in I</etc/host.conf>."
6970 #: build/C/man5/host.conf.5:139
6972 msgid "B<RESOLV_HOST_CONF>"
6976 #: build/C/man5/host.conf.5:143
6978 "If set, this variable points to a file that should be read instead of "
6979 "I</etc/host.conf>."
6983 #: build/C/man5/host.conf.5:143
6985 msgid "B<RESOLV_SERV_ORDER>"
6989 #: build/C/man5/host.conf.5:148
6990 msgid "Overrides the I<order> command."
6994 #: build/C/man5/host.conf.5:148
6996 msgid "B<RESOLV_SPOOF_CHECK>"
7000 #: build/C/man5/host.conf.5:157
7002 "Overrides the I<nospoof>, I<spoofalert> and I<spoof> commands in the same "
7003 "way as the I<spoof> command is parsed. Valid values are I<off>, I<nowarn> "
7008 #: build/C/man5/host.conf.5:157
7010 msgid "B<RESOLV_MULTI>"
7014 #: build/C/man5/host.conf.5:162
7015 msgid "Overrides the I<multi> command."
7019 #: build/C/man5/host.conf.5:162
7021 msgid "B<RESOLV_REORDER>"
7025 #: build/C/man5/host.conf.5:167
7026 msgid "Overrides the I<reorder> command."
7030 #: build/C/man5/host.conf.5:167
7032 msgid "B<RESOLV_ADD_TRIM_DOMAINS>"
7036 #: build/C/man5/host.conf.5:172
7038 "A list of domains, separated by colons (\\(aq:\\(aq), semicolons "
7039 "(\\(aq;\\(aq) or commas (\\(aq,\\(aq), with the leading dot, which will be "
7040 "added to the list of domains that should be trimmed."
7044 #: build/C/man5/host.conf.5:172
7046 msgid "B<RESOLV_OVERRIDE_TRIM_DOMAINS>"
7050 #: build/C/man5/host.conf.5:180
7052 "A list of domains, separated by colons (\\(aq:\\(aq), semicolons "
7053 "(\\(aq;\\(aq) or commas (\\(aq,\\(aq), with the leading dot, which will "
7054 "replace the list of domains that should be trimmed. Overrides the I<trim> "
7059 #: build/C/man5/host.conf.5:184 build/C/man5/host.conf.5:187
7060 msgid "Resolver configuration file"
7064 #: build/C/man5/host.conf.5:184
7066 msgid "I</etc/resolv.conf>"
7070 #: build/C/man5/host.conf.5:190
7071 msgid "Local hosts database"
7075 #: build/C/man5/host.conf.5:199
7077 "The following differences exist compared to the original implementation. A "
7078 "new command I<spoof> and a new environment variable B<RESOLV_SPOOF_CHECK> "
7079 "can take arguments like I<off>, I<nowarn> and I<warn>. Line comments can "
7080 "appear anywhere and not only at the beginning of a line."
7084 #: build/C/man5/host.conf.5:203
7085 msgid "B<gethostbyname>(3), B<hostname>(7), B<named>(8), B<resolv+>(8)"
7089 #: build/C/man7/hostname.7:39
7095 #: build/C/man7/hostname.7:39
7101 #: build/C/man7/hostname.7:42
7102 msgid "hostname - hostname resolution description"
7106 #: build/C/man7/hostname.7:46
7108 "Hostnames are domains, where a domain is a hierarchical, dot-separated list "
7109 "of subdomains; for example, the machine monet, in the Berkeley subdomain of "
7110 "the EDU domain would be represented as \"monet.Berkeley.EDU\"."
7114 #: build/C/man7/hostname.7:55
7116 "Hostnames are often used with network client and server programs, which must "
7117 "generally translate the name to an address for use. (This task is generally "
7118 "performed by either B<getaddrinfo>(3) or the obsolete B<gethostbyname>(3).) "
7119 "Hostnames are resolved by the Internet name resolver in the following "
7124 #: build/C/man7/hostname.7:68
7126 "If the name consists of a single component, that is, contains no dot, and if "
7127 "the environment variable B<HOSTALIASES> is set to the name of a file, that "
7128 "file is searched for any string matching the input hostname. The file "
7129 "should consist of lines made up of two white-space separated strings, the "
7130 "first of which is the hostname alias, and the second of which is the "
7131 "complete hostname to be substituted for that alias. If a case-insensitive "
7132 "match is found between the hostname to be resolved and the first field of a "
7133 "line in the file, the substituted name is looked up with no further "
7138 #: build/C/man7/hostname.7:72
7140 "If the input name ends with a trailing dot, the trailing dot is removed, and "
7141 "the remaining name is looked up with no further processing."
7145 #: build/C/man7/hostname.7:85
7147 "If the input name does not end with a trailing dot, it is looked up by "
7148 "searching through a list of domains until a match is found. The default "
7149 "search list includes first the local domain, then its parent domains with at "
7150 "least 2 name components (longest first). For example, in the domain "
7151 "CS.Berkeley.EDU, the name lithium.CChem will be checked first as "
7152 "lithium.CChem.CS.Berkeley.EDU and then as lithium.CChem.Berkeley.EDU. "
7153 "Lithium.CChem.EDU will not be tried, as there is only one component "
7154 "remaining from the local domain. The search path can be changed from the "
7155 "default by a system-wide configuration file (see B<resolver>(5))."
7159 #: build/C/man7/hostname.7:89
7160 msgid "B<gethostbyname>(3), B<resolver>(5), B<mailaddr>(7), B<named>(8)"
7164 #: build/C/man5/hosts.5:27
7170 #: build/C/man5/hosts.5:27
7176 #: build/C/man5/hosts.5:30
7177 msgid "hosts - static table lookup for hostnames"
7181 #: build/C/man5/hosts.5:32
7182 msgid "B</etc/hosts>"
7186 #: build/C/man5/hosts.5:40
7188 "This manual page describes the format of the I</etc/hosts> file. This file "
7189 "is a simple text file that associates IP addresses with hostnames, one line "
7190 "per IP address. For each host a single line should be present with the "
7191 "following information:"
7195 #: build/C/man5/hosts.5:43
7196 msgid "IP_address canonical_hostname [aliases...]"
7200 #: build/C/man5/hosts.5:56
7202 "Fields of the entry are separated by any number of blanks and/or tab "
7203 "characters. Text from a \"#\" character until the end of the line is a "
7204 "comment, and is ignored. Host names may contain only alphanumeric "
7205 "characters, minus signs (\"-\"), and periods (\".\"). They must begin with "
7206 "an alphabetic character and end with an alphanumeric character. Optional "
7207 "aliases provide for name changes, alternate spellings, shorter hostnames, or "
7208 "generic hostnames (for example, I<localhost>)."
7212 #: build/C/man5/hosts.5:64
7214 "The Berkeley Internet Name Domain (BIND) Server implements the Internet name "
7215 "server for UNIX systems. It augments or replaces the I</etc/hosts> file or "
7216 "hostname lookup, and frees a host from relying on I</etc/hosts> being up to "
7217 "date and complete."
7221 #: build/C/man5/hosts.5:67
7223 "In modern systems, even though the host table has been superseded by DNS, it "
7224 "is still widely used for:"
7228 #: build/C/man5/hosts.5:67
7230 msgid "B<bootstrapping>"
7234 #: build/C/man5/hosts.5:73
7236 "Most systems have a small host table containing the name and address "
7237 "information for important hosts on the local network. This is useful when "
7238 "DNS is not running, for example during system bootup."
7242 #: build/C/man5/hosts.5:73
7248 #: build/C/man5/hosts.5:79
7250 "Sites that use NIS use the host table as input to the NIS host database. "
7251 "Even though NIS can be used with DNS, most NIS sites still use the host "
7252 "table with an entry for all local hosts as a backup."
7256 #: build/C/man5/hosts.5:79
7258 msgid "B<isolated nodes>"
7262 #: build/C/man5/hosts.5:86
7264 "Very small sites that are isolated from the network use the host table "
7265 "instead of DNS. If the local information rarely changes, and the network is "
7266 "not connected to the Internet, DNS offers little advantage."
7270 #: build/C/man5/hosts.5:91
7272 "Modifications to this file normally take effect immediately, except in cases "
7273 "where the file is cached by applications."
7277 #: build/C/man5/hosts.5:91
7279 msgid "Historical notes"
7283 #: build/C/man5/hosts.5:94
7285 "RFC\\ 952 gave the original format for the host table, though it has since "
7290 #: build/C/man5/hosts.5:107
7292 "Before the advent of DNS, the host table was the only way of resolving "
7293 "hostnames on the fledgling Internet. Indeed, this file could be created "
7294 "from the official host data base maintained at the Network Information "
7295 "Control Center (NIC), though local changes were often required to bring it "
7296 "up to date regarding unofficial aliases and/or unknown hosts. The NIC no "
7297 "longer maintains the hosts.txt files, though looking around at the time of "
7298 "writing (circa 2000), there are historical hosts.txt files on the WWW. I "
7299 "just found three, from 92, 94, and 95."
7303 #: build/C/man5/hosts.5:114
7306 "127.0.0.1 localhost\n"
7307 "192.168.1.10 foo.mydomain.org foo\n"
7308 "192.168.1.13 bar.mydomain.org bar\n"
7309 "146.82.138.7 master.debian.org master\n"
7310 "209.237.226.90 www.opensource.org\n"
7314 #: build/C/man5/hosts.5:121
7315 msgid "B<hostname>(1), B<resolver>(3), B<resolver>(5), B<hostname>(7), B<named>(8)"
7319 #: build/C/man5/hosts.5:122
7320 msgid "Internet RFC\\ 952"
7324 #: build/C/man5/hosts.equiv.5:6
7330 #: build/C/man5/hosts.equiv.5:6
7336 #: build/C/man5/hosts.equiv.5:11
7338 "/etc/hosts.equiv - list of hosts and users that are granted \"trusted\" B<r> "
7339 "command access to your system"
7343 #: build/C/man5/hosts.equiv.5:22
7345 "The B<hosts.equiv> file allows or denies hosts and users to use the "
7346 "B<r>-commands (e.g., B<rlogin>, B<rsh>, or B<rcp>) without supplying a "
7351 #: build/C/man5/hosts.equiv.5:24
7352 msgid "The file uses the following format:"
7356 #: build/C/man5/hosts.equiv.5:24
7358 msgid "I<[ + | - ]> I<[hostname]> I<[username]>"
7362 #: build/C/man5/hosts.equiv.5:43
7364 "The I<hostname> is the name of a host which is logically equivalent to the "
7365 "local host. Users logged into that host are allowed to access like-named "
7366 "user accounts on the local host without supplying a password. The "
7367 "I<hostname> may be (optionally) preceded by a plus (+) sign. If the plus "
7368 "sign is used alone, it allows any host to access your system. You can "
7369 "explicitly deny access to a host by preceding the I<hostname> by a minus (-) "
7370 "sign. Users from that host must always supply a password. For security "
7371 "reasons you should always use the FQDN of the hostname and not the short "
7376 #: build/C/man5/hosts.equiv.5:61
7378 "The I<username> entry grants a specific user access to all user accounts "
7379 "(except root) without supplying a password. That means the user is NOT "
7380 "restricted to like-named accounts. The I<username> may be (optionally) "
7381 "preceded by a plus (+) sign. You can also explicitly deny access to a "
7382 "specific user by preceding the I<username> with a minus (-) sign. This says "
7383 "that the user is not trusted no matter what other entries for that host "
7388 #: build/C/man5/hosts.equiv.5:63
7389 msgid "Netgroups can be specified by preceding the netgroup by an @ sign."
7393 #: build/C/man5/hosts.equiv.5:69
7395 "Be extremely careful when using the plus (+) sign. A simple typographical "
7396 "error could result in a standalone plus sign. A standalone plus sign is a "
7397 "wildcard character that means \"any host\"!"
7401 #: build/C/man5/hosts.equiv.5:71
7402 msgid "I</etc/hosts.equiv>"
7406 #: build/C/man5/hosts.equiv.5:76
7408 "Some systems will honor the contents of this file only when it has owner "
7409 "root and no write permission for anybody else. Some exceptionally paranoid "
7410 "systems even require that there be no other hard links to the file."
7414 #: build/C/man5/hosts.equiv.5:84
7416 "Modern systems use the Pluggable Authentication Modules library (PAM). With "
7417 "PAM a standalone plus sign is considered a wildcard character which means "
7418 "\"any host\" only when the word I<promiscuous> is added to the auth "
7419 "component line in your PAM file for the particular service (e.g., "
7424 #: build/C/man5/hosts.equiv.5:87
7425 msgid "B<rhosts>(5), B<rlogind>(8), B<rshd>(8)"
7429 #: build/C/man7/icmp.7:12
7435 #: build/C/man7/icmp.7:12 build/C/man8/nscd.8:23 build/C/man7/raw.7:13
7441 #: build/C/man7/icmp.7:15
7442 msgid "icmp - Linux IPv4 ICMP kernel module."
7446 #: build/C/man7/icmp.7:23
7448 "This kernel protocol module implements the Internet Control Message Protocol "
7449 "defined in RFC\\ 792. It is used to signal error conditions and for "
7450 "diagnosis. The user doesn't interact directly with this module; instead it "
7451 "communicates with the other protocols in the kernel and these pass the ICMP "
7452 "errors to the application layers. The kernel ICMP module also answers ICMP "
7457 #: build/C/man7/icmp.7:35
7459 "A user protocol may receive ICMP packets for all local sockets by opening a "
7460 "raw socket with the protocol B<IPPROTO_ICMP>. See B<raw>(7) for more "
7461 "information. The types of ICMP packets passed to the socket can be filtered "
7462 "using the B<ICMP_FILTER> socket option. ICMP packets are always processed "
7463 "by the kernel too, even when passed to a user socket."
7467 #: build/C/man7/icmp.7:41
7469 "Linux limits the rate of ICMP error packets to each destination. "
7470 "B<ICMP_REDIRECT> and B<ICMP_DEST_UNREACH> are also limited by the "
7471 "destination route of the incoming packets."
7474 #. FIXME . better description needed
7476 #: build/C/man7/icmp.7:54
7478 "ICMP supports a set of I</proc> interfaces to configure some global IP "
7479 "parameters. The parameters can be accessed by reading or writing files in "
7480 "the directory I</proc/sys/net/ipv4/>. Most of these parameters are rate "
7481 "limitations for specific ICMP types. Linux 2.2 uses a token bucket filter "
7482 "to limit ICMPs. The value is the timeout in jiffies until the token bucket "
7483 "filter is cleared after a burst. A jiffy is a system dependent unit, "
7484 "usually 10ms on i386 and about 1ms on alpha and ia64."
7488 #: build/C/man7/icmp.7:54
7490 msgid "I<icmp_destunreach_rate> (Linux 2.2 to 2.4.9)"
7493 #. Precisely: from 2.1.102
7495 #: build/C/man7/icmp.7:63
7497 "Maximum rate to send ICMP Destination Unreachable packets. This limits the "
7498 "rate at which packets are sent to any individual route or destination. The "
7499 "limit does not affect sending of B<ICMP_FRAG_NEEDED> packets needed for path "
7504 #: build/C/man7/icmp.7:63
7506 msgid "I<icmp_echo_ignore_all> (since Linux 2.2)"
7509 #. Precisely: 2.1.68
7511 #: build/C/man7/icmp.7:69
7512 msgid "If this value is nonzero, Linux will ignore all B<ICMP_ECHO> requests."
7516 #: build/C/man7/icmp.7:69
7518 msgid "I<icmp_echo_ignore_broadcasts> (since Linux 2.2)"
7521 #. Precisely: from 2.1.68
7523 #: build/C/man7/icmp.7:75
7525 "If this value is nonzero, Linux will ignore all B<ICMP_ECHO> packets sent to "
7526 "broadcast addresses."
7530 #: build/C/man7/icmp.7:75
7532 msgid "I<icmp_echoreply_rate> (Linux 2.2 to 2.4.9)"
7535 #. Precisely: from 2.1.102
7537 #: build/C/man7/icmp.7:83
7539 "Maximum rate for sending B<ICMP_ECHOREPLY> packets in response to "
7540 "B<ICMP_ECHOREQUEST> packets."
7544 #: build/C/man7/icmp.7:83
7547 "I<icmp_errors_use_inbound_ifaddr> (Boolean; default: disabled; since Linux "
7551 #. The following taken from 2.6.28-rc4 Documentation/networking/ip-sysctl.txt
7553 #: build/C/man7/icmp.7:88
7555 "If disabled, ICMP error messages are sent with the primary address of the "
7556 "exiting interface."
7560 #: build/C/man7/icmp.7:94
7562 "If enabled, the message will be sent with the primary address of the "
7563 "interface that received the packet that caused the ICMP error. This is the "
7564 "behavior that many network administrators will expect from a router. And it "
7565 "can make debugging complicated network layouts much easier."
7569 #: build/C/man7/icmp.7:98
7571 "Note that if no primary address exists for the interface selected, then the "
7572 "primary address of the first non-loopback interface that has one will be "
7573 "used regardless of this setting."
7577 #: build/C/man7/icmp.7:98
7580 "I<icmp_ignore_bogus_error_responses> (Boolean; default: disabled; since "
7584 #. precisely: since 2.1.32
7585 #. The following taken from 2.6.28-rc4 Documentation/networking/ip-sysctl.txt
7587 #: build/C/man7/icmp.7:106
7589 "Some routers violate RFC1122 by sending bogus responses to broadcast "
7590 "frames. Such violations are normally logged via a kernel warning. If this "
7591 "parameter is enabled, the kernel will not give such warnings, which will "
7592 "avoid log file clutter."
7596 #: build/C/man7/icmp.7:106
7598 msgid "I<icmp_paramprob_rate> (Linux 2.2 to 2.4.9)"
7601 #. Precisely: from 2.1.102
7603 #: build/C/man7/icmp.7:113
7605 "Maximum rate for sending B<ICMP_PARAMETERPROB> packets. These packets are "
7606 "sent when a packet arrives with an invalid IP header."
7610 #: build/C/man7/icmp.7:113
7612 msgid "I<icmp_ratelimit> (integer; default: 1000; since Linux 2.4.10)"
7615 #. The following taken from 2.6.28-rc4 Documentation/networking/ip-sysctl.txt
7617 #: build/C/man7/icmp.7:121
7619 "Limit the maximum rates for sending ICMP packets whose type matches "
7620 "I<icmp_ratemask> (see below) to specific targets. 0 to disable any "
7621 "limiting, otherwise the minimum space between responses in milliseconds."
7625 #: build/C/man7/icmp.7:121
7627 msgid "I<icmp_ratemask> (integer; default: see below; since Linux 2.4.10)"
7630 #. The following taken from 2.6.28-rc4 Documentation/networking/ip-sysctl.txt
7632 #: build/C/man7/icmp.7:125
7633 msgid "Mask made of ICMP types for which rates are being limited."
7637 #: build/C/man7/icmp.7:127
7638 msgid "Significant bits: IHGFEDCBA9876543210"
7642 #: build/C/man7/icmp.7:129
7643 msgid "Default mask: 0000001100000011000 (0x1818)"
7647 #: build/C/man7/icmp.7:132
7648 msgid "Bit definitions (see the Linux kernel source file I<include/linux/icmp.h>):"
7652 #: build/C/man7/icmp.7:136
7654 msgid "0 Echo Reply\n"
7658 #: build/C/man7/icmp.7:137
7660 msgid "3 Destination Unreachable *\n"
7664 #: build/C/man7/icmp.7:138
7666 msgid "4 Source Quench *\n"
7670 #: build/C/man7/icmp.7:139
7672 msgid "5 Redirect\n"
7676 #: build/C/man7/icmp.7:140
7678 msgid "8 Echo Request\n"
7682 #: build/C/man7/icmp.7:141
7684 msgid "B Time Exceeded *\n"
7688 #: build/C/man7/icmp.7:142
7690 msgid "C Parameter Problem *\n"
7694 #: build/C/man7/icmp.7:143
7696 msgid "D Timestamp Request\n"
7700 #: build/C/man7/icmp.7:144
7702 msgid "E Timestamp Reply\n"
7706 #: build/C/man7/icmp.7:145
7708 msgid "F Info Request\n"
7712 #: build/C/man7/icmp.7:146
7714 msgid "G Info Reply\n"
7718 #: build/C/man7/icmp.7:147
7720 msgid "H Address Mask Request\n"
7724 #: build/C/man7/icmp.7:148
7726 msgid "I Address Mask Reply\n"
7730 #: build/C/man7/icmp.7:154
7732 "The bits marked with an asterisk are rate limited by default (see the "
7733 "default mask above)."
7737 #: build/C/man7/icmp.7:154
7739 msgid "I<icmp_timeexceed_rate> (Linux 2.2 to 2.4.9)"
7743 #: build/C/man7/icmp.7:161
7745 "Maximum rate for sending B<ICMP_TIME_EXCEEDED> packets. These packets are "
7746 "sent to prevent loops when a packet has crossed too many hops."
7750 #: build/C/man7/icmp.7:165
7751 msgid "Support for the B<ICMP_ADDRESS> request was removed in 2.2."
7755 #: build/C/man7/icmp.7:169
7756 msgid "Support for B<ICMP_SOURCE_QUENCH> was removed in Linux 2.2."
7759 #. not really true ATM
7761 #. Linux ICMP should be compliant to RFC 1122.
7763 #: build/C/man7/icmp.7:177
7765 "As many other implementations don't support B<IPPROTO_ICMP> raw sockets, "
7766 "this feature should not be relied on in portable programs."
7770 #: build/C/man7/icmp.7:182
7772 "B<ICMP_REDIRECT> packets are not sent when Linux is not acting as a router. "
7773 "They are also accepted only from the old gateway defined in the routing "
7774 "table and the redirect routes are expired after some time."
7778 #: build/C/man7/icmp.7:186
7780 "The 64-bit timestamp returned by B<ICMP_TIMESTAMP> is in milliseconds since "
7781 "the Epoch, 1970-01-01 00:00:00 +0000 (UTC)."
7785 #: build/C/man7/icmp.7:191
7787 "Linux ICMP internally uses a raw socket to send ICMPs. This raw socket may "
7788 "appear in B<netstat>(8) output with a zero inode."
7792 #: build/C/man7/icmp.7:193
7797 #: build/C/man7/icmp.7:194
7798 msgid "RFC\\ 792 for a description of the ICMP protocol."
7802 #: build/C/man3/inet.3:42
7808 #: build/C/man3/inet.3:46
7810 "inet_aton, inet_addr, inet_network, inet_ntoa, inet_makeaddr, inet_lnaof, "
7811 "inet_netof - Internet address manipulation routines"
7815 #: build/C/man3/inet.3:51
7818 "B<#include E<lt>sys/socket.hE<gt>>\n"
7819 "B<#include E<lt>netinet/in.hE<gt>>\n"
7820 "B<#include E<lt>arpa/inet.hE<gt>>\n"
7824 #: build/C/man3/inet.3:53
7826 msgid "B<int inet_aton(const char *>I<cp>B<, struct in_addr *>I<inp>B<);>\n"
7830 #: build/C/man3/inet.3:55
7832 msgid "B<in_addr_t inet_addr(const char *>I<cp>B<);>\n"
7836 #: build/C/man3/inet.3:57
7838 msgid "B<in_addr_t inet_network(const char *>I<cp>B<);>\n"
7842 #: build/C/man3/inet.3:59
7844 msgid "B<char *inet_ntoa(struct in_addr >I<in>B<);>\n"
7848 #: build/C/man3/inet.3:61
7851 "B<struct in_addr inet_makeaddr(in_addr_t >I<net>B<, in_addr_t "
7856 #: build/C/man3/inet.3:63
7858 msgid "B<in_addr_t inet_lnaof(struct in_addr >I<in>B<);>\n"
7862 #: build/C/man3/inet.3:65
7864 msgid "B<in_addr_t inet_netof(struct in_addr >I<in>B<);>\n"
7868 #: build/C/man3/inet.3:75
7869 msgid "B<inet_aton>(), B<inet_ntoa>(): _BSD_SOURCE || _SVID_SOURCE"
7873 #: build/C/man3/inet.3:85
7875 "B<inet_aton>() converts the Internet host address I<cp> from the IPv4 "
7876 "numbers-and-dots notation into binary form (in network byte order) and "
7877 "stores it in the structure that I<inp> points to. B<inet_aton>() returns "
7878 "nonzero if the address is valid, zero if not. The address supplied in I<cp> "
7879 "can have one of the following forms:"
7883 #: build/C/man3/inet.3:85
7889 #: build/C/man3/inet.3:89
7891 "Each of the four numeric parts specifies a byte of the address; the bytes "
7892 "are assigned in left-to-right order to produce the binary address."
7896 #: build/C/man3/inet.3:89
7902 #: build/C/man3/inet.3:102
7904 "Parts I<a> and I<b> specify the first two bytes of the binary address. Part "
7905 "I<c> is interpreted as a 16-bit value that defines the rightmost two bytes "
7906 "of the binary address. This notation is suitable for specifying (outmoded) "
7907 "Class B network addresses."
7911 #: build/C/man3/inet.3:102
7917 #: build/C/man3/inet.3:113
7919 "Part I<a> specifies the first byte of the binary address. Part I<b> is "
7920 "interpreted as a 24-bit value that defines the rightmost three bytes of the "
7921 "binary address. This notation is suitable for specifying (outmoded) Class A "
7922 "network addresses."
7926 #: build/C/man3/inet.3:113
7932 #: build/C/man3/inet.3:119
7934 "The value I<a> is interpreted as a 32-bit value that is stored directly into "
7935 "the binary address without any byte rearrangement."
7939 #: build/C/man3/inet.3:132
7941 "In all of the above forms, components of the dotted address can be specified "
7942 "in decimal, octal (with a leading I<0>), or hexadecimal, with a leading "
7943 "I<0X>). Addresses in any of these forms are collectively termed I<IPV4 "
7944 "numbers-and-dots notation>. The form that uses exactly four decimal numbers "
7945 "is referred to as I<IPv4 dotted-decimal notation> (or sometimes: I<IPv4 "
7946 "dotted-quad notation>)."
7950 #: build/C/man3/inet.3:140
7952 "B<inet_aton>() returns 1 if the supplied string was successfully "
7953 "interpreted, or 0 if the string is invalid (B<errno> is I<not> set on "
7958 #: build/C/man3/inet.3:157
7960 "The B<inet_addr>() function converts the Internet host address I<cp> from "
7961 "IPv4 numbers-and-dots notation into binary data in network byte order. If "
7962 "the input is invalid, B<INADDR_NONE> (usually -1) is returned. Use of this "
7963 "function is problematic because -1 is a valid address (255.255.255.255). "
7964 "Avoid its use in favor of B<inet_aton>(), B<inet_pton>(3), or "
7965 "B<getaddrinfo>(3), which provide a cleaner way to indicate error return."
7969 #: build/C/man3/inet.3:167
7971 "The B<inet_network>() function converts I<cp>, a string in IPv4 "
7972 "numbers-and-dots notation, into a number in host byte order suitable for use "
7973 "as an Internet network address. On success, the converted address is "
7974 "returned. If the input is invalid, -1 is returned."
7978 #: build/C/man3/inet.3:175
7980 "The B<inet_ntoa>() function converts the Internet host address I<in>, given "
7981 "in network byte order, to a string in IPv4 dotted-decimal notation. The "
7982 "string is returned in a statically allocated buffer, which subsequent calls "
7987 #: build/C/man3/inet.3:181
7989 "The B<inet_lnaof>() function returns the local network address part of the "
7990 "Internet address I<in>. The returned value is in host byte order."
7994 #: build/C/man3/inet.3:187
7996 "The B<inet_netof>() function returns the network number part of the "
7997 "Internet address I<in>. The returned value is in host byte order."
8001 #: build/C/man3/inet.3:198
8003 "The B<inet_makeaddr>() function is the converse of B<inet_netof>() and "
8004 "B<inet_lnaof>(). It returns an Internet host address in network byte order, "
8005 "created by combining the network number I<net> with the local address "
8006 "I<host>, both in host byte order."
8010 #: build/C/man3/inet.3:208
8012 "The structure I<in_addr> as used in B<inet_ntoa>(), B<inet_makeaddr>(), "
8013 "B<inet_lnaof>() and B<inet_netof>() is defined in "
8014 "I<E<lt>netinet/in.hE<gt>> as:"
8018 #: build/C/man3/inet.3:212
8020 msgid "typedef uint32_t in_addr_t;\n"
8024 #: build/C/man3/inet.3:216
8027 "struct in_addr {\n"
8028 " in_addr_t s_addr;\n"
8033 #: build/C/man3/inet.3:226
8035 "4.3BSD. B<inet_addr>() and B<inet_ntoa>() are specified in POSIX.1-2001. "
8036 "B<inet_aton>() is not specified in POSIX.1-2001, but is available on most "
8041 #: build/C/man3/inet.3:230
8043 "On the i386 the host byte order is Least Significant Byte first (little "
8044 "endian), whereas the network byte order, as used on the Internet, is Most "
8045 "Significant Byte first (big endian)."
8049 #: build/C/man3/inet.3:239
8051 "B<inet_lnaof>(), B<inet_netof>(), and B<inet_makeaddr>() are legacy "
8052 "functions that assume they are dealing with I<classful network addresses>. "
8053 "Classful networking divides IPv4 network addresses into host and network "
8054 "components at byte boundaries, as follows:"
8058 #: build/C/man3/inet.3:239
8064 #: build/C/man3/inet.3:245
8066 "This address type is indicated by the value 0 in the most significant bit of "
8067 "the (network byte ordered) address. The network address is contained in the "
8068 "most significant byte, and the host address occupies the remaining three "
8073 #: build/C/man3/inet.3:245
8079 #: build/C/man3/inet.3:251
8081 "This address type is indicated by the binary value 10 in the most "
8082 "significant two bits of the address. The network address is contained in "
8083 "the two most significant bytes, and the host address occupies the remaining "
8088 #: build/C/man3/inet.3:251
8094 #: build/C/man3/inet.3:257
8096 "This address type is indicated by the binary value 110 in the most "
8097 "significant three bits of the address. The network address is contained in "
8098 "the three most significant bytes, and the host address occupies the "
8103 #: build/C/man3/inet.3:262
8105 "Classful network addresses are now obsolete, having been superseded by "
8106 "Classless Inter-Domain Routing (CIDR), which divides addresses into network "
8107 "and host components at arbitrary bit (rather than byte) boundaries."
8111 #: build/C/man3/inet.3:269
8113 "An example of the use of B<inet_aton>() and B<inet_ntoa>() is shown "
8114 "below. Here are some example runs:"
8118 #: build/C/man3/inet.3:276
8121 "$B< ./a.out 226.000.000.037> # Last byte is in octal\n"
8123 "$B< ./a.out 0x7f.1 > # First byte is in hex\n"
8128 #: build/C/man3/inet.3:285
8131 "#define _BSD_SOURCE\n"
8132 "#include E<lt>arpa/inet.hE<gt>\n"
8133 "#include E<lt>stdio.hE<gt>\n"
8134 "#include E<lt>stdlib.hE<gt>\n"
8138 #: build/C/man3/inet.3:290
8142 "main(int argc, char *argv[])\n"
8144 " struct in_addr addr;\n"
8148 #: build/C/man3/inet.3:295
8151 " if (argc != 2) {\n"
8152 " fprintf(stderr, \"%s E<lt>dotted-addressE<gt>\\en\", argv[0]);\n"
8153 " exit(EXIT_FAILURE);\n"
8158 #: build/C/man3/inet.3:300
8161 " if (inet_aton(argv[1], &addr) == 0) {\n"
8162 " fprintf(stderr, \"Invalid address\\en\");\n"
8163 " exit(EXIT_FAILURE);\n"
8168 #: build/C/man3/inet.3:304
8171 " printf(\"%s\\en\", inet_ntoa(addr));\n"
8172 " exit(EXIT_SUCCESS);\n"
8177 #: build/C/man3/inet.3:315
8179 "B<byteorder>(3), B<getaddrinfo>(3), B<gethostbyname>(3), B<getnameinfo>(3), "
8180 "B<getnetent>(3), B<inet_net_pton>(3), B<inet_ntop>(3), B<inet_pton>(3), "
8181 "B<hosts>(5), B<networks>(5)"
8185 #: build/C/man3/inet_net_pton.3:26
8187 msgid "INET_NET_PTON"
8191 #: build/C/man3/inet_net_pton.3:29
8192 msgid "inet_net_pton, inet_net_ntop - Internet network number conversion"
8196 #: build/C/man3/inet_net_pton.3:35
8199 "B<int inet_net_pton(int >I<af>B<, const char *>I<pres>B<,>\n"
8200 "B< void *>I<netp>B<, size_t >I<nsize>B<);>\n"
8204 #: build/C/man3/inet_net_pton.3:38
8207 "B<char *inet_net_ntop(int >I<af>B<, const void *>I<netp>B<, int "
8209 "B< char *>I<pres>B<, size_t >I<psize>B<);>\n"
8213 #: build/C/man3/inet_net_pton.3:41 build/C/man3/resolver.3:85
8214 msgid "Link with I<-lresolv>."
8218 #: build/C/man3/inet_net_pton.3:49
8219 msgid "B<inet_net_pton>(), B<inet_net_ntop>():"
8223 #: build/C/man3/inet_net_pton.3:52
8225 msgid "Since glibc 2.20:"
8229 #: build/C/man3/inet_net_pton.3:55
8230 msgid "_DEFAULT_SOURCE"
8234 #: build/C/man3/inet_net_pton.3:55
8236 msgid "Before glibc 2.20:"
8240 #: build/C/man3/inet_net_pton.3:64
8242 "These functions convert network numbers between presentation (i.e., "
8243 "printable) format and network (i.e., binary) format."
8247 #: build/C/man3/inet_net_pton.3:70
8249 "For both functions, I<af> specifies the address family for the conversion; "
8250 "the only supported value is B<AF_INET>."
8254 #: build/C/man3/inet_net_pton.3:70
8256 msgid "inet_net_pton()"
8260 #: build/C/man3/inet_net_pton.3:89
8262 "The B<inet_net_pton>() function converts I<pres>, a null-terminated string "
8263 "containing an Internet network number in presentation format to network "
8264 "format. The result of the conversion, which is in network byte order, is "
8265 "placed in the buffer pointed to by I<net>. (The I<netp> argument typically "
8266 "points to an I<in_addr> structure.) The I<nsize> argument specifies the "
8267 "number of bytes available in I<netp>."
8271 #: build/C/man3/inet_net_pton.3:97
8273 "On success, B<inet_net_pton>() returns the number of bits in the network "
8274 "number field of the result placed in I<netp>. For a discussion of the input "
8275 "presentation format and the return value, see NOTES."
8279 #: build/C/man3/inet_net_pton.3:107
8281 "I<Note>: the buffer pointed to by I<netp> should be zeroed out before "
8282 "calling B<inet_net_pton>(), since the call writes only as many bytes as are "
8283 "required for the network number (or as are explicitly specified by I<pres>), "
8284 "which may be less than the number of bytes in a complete network address."
8288 #: build/C/man3/inet_net_pton.3:107
8290 msgid "inet_net_ntop()"
8294 #: build/C/man3/inet_net_pton.3:119
8296 "The B<inet_net_ntop>() function converts the network number in the buffer "
8297 "pointed to by I<netp> to presentation format; I<*netp> is interpreted as a "
8298 "value in network byte order. The I<bits> argument specifies the number of "
8299 "bits in the network number in I<*netp>."
8303 #: build/C/man3/inet_net_pton.3:130
8305 "The null-terminated presentation-format string is placed in the buffer "
8306 "pointed to by I<pres>. The I<psize> argument specifies the number of bytes "
8307 "available in I<pres>. The presentation string is in CIDR format: a "
8308 "dotted-decimal number representing the network address, followed by a slash, "
8309 "and the size of the network number in bits."
8313 #: build/C/man3/inet_net_pton.3:137
8315 "On success, B<inet_net_pton>() returns the number of bits in the network "
8316 "number. On error, it returns -1, and I<errno> is set to indicate the cause "
8321 #: build/C/man3/inet_net_pton.3:145
8323 "On success, B<inet_net_ntop>() returns I<pres>. On error, it returns NULL, "
8324 "and I<errno> is set to indicate the cause of the error."
8328 #: build/C/man3/inet_net_pton.3:146 build/C/man3/inet_ntop.3:92
8330 msgid "B<EAFNOSUPPORT>"
8334 #: build/C/man3/inet_net_pton.3:151
8335 msgid "I<af> specified a value other than B<AF_INET>."
8339 #: build/C/man3/inet_net_pton.3:154
8340 msgid "The size of the output buffer was insufficient."
8344 #: build/C/man3/inet_net_pton.3:159
8345 msgid "(B<inet_net_pton>()) I<pres> was not in correct presentation format."
8349 #: build/C/man3/inet_net_pton.3:165
8351 "The B<inet_net_pton>() and B<inet_net_ntop>() functions are nonstandard, "
8352 "but widely available."
8356 #: build/C/man3/inet_net_pton.3:166
8358 msgid "Input presentation format for inet_net_pton()"
8362 #: build/C/man3/inet_net_pton.3:170
8364 "The network number may be specified either as a hexadecimal value or in "
8365 "dotted-decimal notation."
8368 #. If the hexadecimal string is short, the remaining nibbles are zeroed.
8370 #: build/C/man3/inet_net_pton.3:175
8372 "Hexadecimal values are indicated by an initial \"0x\" or \"0X\". The "
8373 "hexadecimal digits populate the nibbles (half octets) of the network number "
8374 "from left to right in network byte order."
8378 #: build/C/man3/inet_net_pton.3:179
8380 "In dotted-decimal notation, up to four octets are specified, as decimal "
8381 "numbers separated by dots. Thus, any of the following forms are accepted:"
8385 #: build/C/man3/inet_net_pton.3:184
8394 #. Reading other man pages, some other implementations treat
8395 #. 'c' in a.b.c as a 16-bit number that populates right-most two bytes
8396 #. 'b' in a.b as a 24-bit number that populates right-most three bytes
8398 #: build/C/man3/inet_net_pton.3:192
8400 "Each part is a number in the range 0 to 255 that populates one byte of the "
8401 "resulting network number, going from left to right, in network-byte (big "
8402 "endian) order. Where a part is omitted, the resulting byte in the network "
8407 #: build/C/man3/inet_net_pton.3:197
8409 "For either hexadecimal or dotted-decimal format, the network number can "
8410 "optionally be followed by a slash and a number in the range 0 to 32, which "
8411 "specifies the size of the network number in bits."
8415 #: build/C/man3/inet_net_pton.3:197
8417 msgid "Return value of inet_net_pton()"
8421 #: build/C/man3/inet_net_pton.3:207
8423 "The return value of B<inet_net_pton>() is the number of bits in the network "
8424 "number field. If the input presentation string terminates with a slash and "
8425 "an explicit size value, then that size becomes the return value of "
8426 "B<inet_net_pton>(). Otherwise, the return value, I<bits>, is inferred as "
8431 #: build/C/man3/inet_net_pton.3:213
8433 "If the most significant byte of the network number is greater than or equal "
8434 "to 240, then I<bits> is 32."
8438 #: build/C/man3/inet_net_pton.3:220
8440 "Otherwise, if the most significant byte of the network number is greater "
8441 "than or equal to 224, then I<bits> is 4."
8445 #: build/C/man3/inet_net_pton.3:227
8447 "Otherwise, if the most significant byte of the network number is greater "
8448 "than or equal to 192, then I<bits> is 24."
8452 #: build/C/man3/inet_net_pton.3:234
8454 "Otherwise, if the most significant byte of the network number is greater "
8455 "than or equal to 128, then I<bits> is 16."
8459 #: build/C/man3/inet_net_pton.3:238
8460 msgid "Otherwise, I<bits> is 8."
8464 #: build/C/man3/inet_net_pton.3:247
8466 "If the resulting I<bits> value from the above steps is greater than or equal "
8467 "to 8, but the number of octets specified in the network number exceed "
8468 "I<bits/8>, then I<bits> is set to 8 times the number of octets actually "
8473 #: build/C/man3/inet_net_pton.3:261
8475 "The program below demonstrates the use of B<inet_net_pton>() and "
8476 "B<inet_net_ntop>(). It uses B<inet_net_pton>() to convert the presentation "
8477 "format network address provided in its first command-line argument to binary "
8478 "form, displays the return value from B<inet_net_pton>(). It then uses "
8479 "B<inet_net_ntop>() to convert the binary form back to presentation format, "
8480 "and displays the resulting string."
8484 #: build/C/man3/inet_net_pton.3:275
8486 "In order to demonstrate that B<inet_net_pton>() may not write to all bytes "
8487 "of its I<netp> argument, the program allows an optional second command-line "
8488 "argument, a number used to initialize the buffer before B<inet_net_pton>() "
8489 "is called. As its final line of output, the program displays all of the "
8490 "bytes of the buffer returned by B<inet_net_pton>() allowing the user to see "
8491 "which bytes have not been touched by B<inet_net_pton>()."
8495 #: build/C/man3/inet_net_pton.3:279
8497 "An example run, showing that B<inet_net_pton>() infers the number of bits "
8498 "in the network number:"
8502 #: build/C/man3/inet_net_pton.3:286
8505 "$ B<./a.out 193.168>\n"
8506 "inet_net_pton() returned: 24\n"
8507 "inet_net_ntop() yielded: 193.168.0/24\n"
8508 "Raw address: c1a80000\n"
8512 #: build/C/man3/inet_net_pton.3:292
8514 "Demonstrate that B<inet_net_pton>() does not zero out unused bytes in its "
8519 #: build/C/man3/inet_net_pton.3:299
8522 "$ B<./a.out 193.168 0xffffffff>\n"
8523 "inet_net_pton() returned: 24\n"
8524 "inet_net_ntop() yielded: 193.168.0/24\n"
8525 "Raw address: c1a800ff\n"
8529 #: build/C/man3/inet_net_pton.3:307
8531 "Demonstrate that B<inet_net_pton>() will widen the inferred size of the "
8532 "network number, if the supplied number of bytes in the presentation string "
8533 "exceeds the inferred value:"
8537 #: build/C/man3/inet_net_pton.3:314
8540 "$ B<./a.out 193.168.1.128>\n"
8541 "inet_net_pton() returned: 32\n"
8542 "inet_net_ntop() yielded: 193.168.1.128/32\n"
8543 "Raw address: c1a80180\n"
8547 #: build/C/man3/inet_net_pton.3:322
8549 "Explicitly specifying the size of the network number overrides any inference "
8550 "about its size (but any extra bytes that are explicitly specified will still "
8551 "be used by B<inet_net_pton>(): to populate the result buffer):"
8555 #: build/C/man3/inet_net_pton.3:329
8558 "$ B<./a.out 193.168.1.128/24>\n"
8559 "inet_net_pton() returned: 24\n"
8560 "inet_net_ntop() yielded: 193.168.1/24\n"
8561 "Raw address: c1a80180\n"
8565 #: build/C/man3/inet_net_pton.3:334
8567 msgid "/* Link with \"-lresolv\" */\n"
8571 #: build/C/man3/inet_net_pton.3:338
8574 "#include E<lt>arpa/inet.hE<gt>\n"
8575 "#include E<lt>stdio.hE<gt>\n"
8576 "#include E<lt>stdlib.hE<gt>\n"
8580 #: build/C/man3/inet_net_pton.3:341
8583 "#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \\e\n"
8588 #: build/C/man3/inet_net_pton.3:348
8592 "main(int argc, char *argv[])\n"
8595 " struct in_addr addr;\n"
8600 #: build/C/man3/inet_net_pton.3:355
8603 " if (argc E<lt> 2) {\n"
8604 " fprintf(stderr,\n"
8605 " \"Usage: %s presentation-form [addr-init-value]\\en\",\n"
8607 " exit(EXIT_FAILURE);\n"
8612 #: build/C/man3/inet_net_pton.3:361
8615 " /* If argv[2] is supplied (a numeric value), use it to initialize\n"
8616 " the output buffer given to inet_net_pton(), so that we can see\n"
8617 " that inet_net_pton() initializes only those bytes needed for\n"
8618 " the network number. If argv[2] is not supplied, then initialize\n"
8619 " the buffer to zero (as is recommended practice). */\n"
8623 #: build/C/man3/inet_net_pton.3:363
8625 msgid " addr.s_addr = (argc E<gt> 2) ? strtod(argv[2], NULL) : 0;\n"
8629 #: build/C/man3/inet_net_pton.3:365
8631 msgid " /* Convert presentation network number in argv[1] to binary */\n"
8635 #: build/C/man3/inet_net_pton.3:369
8638 " bits = inet_net_pton(AF_INET, argv[1], &addr, sizeof(addr));\n"
8639 " if (bits == -1)\n"
8640 " errExit(\"inet_net_ntop\");\n"
8644 #: build/C/man3/inet_net_pton.3:371
8646 msgid " printf(\"inet_net_pton() returned: %d\\en\", bits);\n"
8650 #: build/C/man3/inet_net_pton.3:374
8653 " /* Convert binary format back to presentation, using \\(aqbits\\(aq\n"
8654 " returned by inet_net_pton() */\n"
8658 #: build/C/man3/inet_net_pton.3:377
8661 " if (inet_net_ntop(AF_INET, &addr, bits, buf, sizeof(buf)) == NULL)\n"
8662 " errExit(\"inet_net_ntop\");\n"
8666 #: build/C/man3/inet_net_pton.3:379
8668 msgid " printf(\"inet_net_ntop() yielded: %s\\en\", buf);\n"
8672 #: build/C/man3/inet_net_pton.3:384
8675 " /* Display \\(aqaddr\\(aq in raw form (in network byte order), so we "
8677 " see bytes not displayed by inet_net_ntop(); some of those bytes\n"
8678 " may not have been touched by inet_net_ntop(), and so will still\n"
8679 " have any initial value that was specified in argv[2]. */\n"
8683 #: build/C/man3/inet_net_pton.3:386
8685 msgid " printf(\"Raw address: %x\\en\", htonl(addr.s_addr));\n"
8689 #: build/C/man3/inet_net_pton.3:392
8690 msgid "B<inet>(3), B<networks>(5)"
8694 #: build/C/man3/inet_ntop.3:26
8700 #: build/C/man3/inet_ntop.3:26
8706 #: build/C/man3/inet_ntop.3:29
8707 msgid "inet_ntop - convert IPv4 and IPv6 addresses from binary to text form"
8711 #: build/C/man3/inet_ntop.3:35
8714 "B<const char *inet_ntop(int >I<af>B<, const void *>I<src>B<,>\n"
8715 "B< char *>I<dst>B<, socklen_t >I<size>B<);>\n"
8719 #: build/C/man3/inet_ntop.3:48
8721 "This function converts the network address structure I<src> in the I<af> "
8722 "address family into a character string. The resulting string is copied to "
8723 "the buffer pointed to by I<dst>, which must be a non-null pointer. The "
8724 "caller specifies the number of bytes available in this buffer in the "
8729 #: build/C/man3/inet_ntop.3:57
8731 "B<inet_ntop>() extends the B<inet_ntoa>(3) function to support multiple "
8732 "address families, B<inet_ntoa>(3) is now considered to be deprecated in "
8733 "favor of B<inet_ntop>(). The following address families are currently "
8738 #: build/C/man3/inet_ntop.3:70
8740 "I<src> points to a I<struct in_addr> (in network byte order) which is "
8741 "converted to an IPv4 network address in the dotted-decimal format, "
8742 "\"I<ddd.ddd.ddd.ddd>\". The buffer I<dst> must be at least "
8743 "B<INET_ADDRSTRLEN> bytes long."
8747 #: build/C/man3/inet_ntop.3:83
8749 "I<src> points to a I<struct in6_addr> (in network byte order) which is "
8750 "converted to a representation of this address in the most appropriate IPv6 "
8751 "network address format for this address. The buffer I<dst> must be at least "
8752 "B<INET6_ADDRSTRLEN> bytes long."
8756 #: build/C/man3/inet_ntop.3:91
8758 "On success, B<inet_ntop>() returns a non-null pointer to I<dst>. NULL is "
8759 "returned if there was an error, with I<errno> set to indicate the error."
8763 #: build/C/man3/inet_ntop.3:96
8764 msgid "I<af> was not a valid address family."
8768 #: build/C/man3/inet_ntop.3:96
8774 #: build/C/man3/inet_ntop.3:100
8775 msgid "The converted address string would exceed the size given by I<size>."
8778 #. 2.1.3: size_t, 2.1.91: socklen_t
8780 #: build/C/man3/inet_ntop.3:112
8782 "POSIX.1-2001. Note that RFC\\ 2553 defines a prototype where the last "
8783 "argument I<size> is of type I<size_t>. Many systems follow RFC\\ 2553. "
8784 "Glibc 2.0 and 2.1 have I<size_t>, but 2.2 and later have I<socklen_t>."
8788 #: build/C/man3/inet_ntop.3:115
8789 msgid "B<AF_INET6> converts IPv4-mapped IPv6 addresses into an IPv6 format."
8793 #: build/C/man3/inet_ntop.3:118
8794 msgid "See B<inet_pton>(3)."
8798 #: build/C/man3/inet_ntop.3:121
8799 msgid "B<getnameinfo>(3), B<inet>(3), B<inet_pton>(3)"
8803 #: build/C/man3/inet_pton.3:27
8809 #: build/C/man3/inet_pton.3:27
8815 #: build/C/man3/inet_pton.3:30
8816 msgid "inet_pton - convert IPv4 and IPv6 addresses from text to binary form"
8820 #: build/C/man3/inet_pton.3:35
8822 msgid "B<int inet_pton(int >I<af>B<, const char *>I<src>B<, void *>I<dst>B<);>\n"
8826 #: build/C/man3/inet_pton.3:51
8828 "This function converts the character string I<src> into a network address "
8829 "structure in the I<af> address family, then copies the network address "
8830 "structure to I<dst>. The I<af> argument must be either B<AF_INET> or "
8835 #: build/C/man3/inet_pton.3:53
8836 msgid "The following address families are currently supported:"
8840 #: build/C/man3/inet_pton.3:67
8842 "I<src> points to a character string containing an IPv4 network address in "
8843 "dotted-decimal format, \"I<ddd.ddd.ddd.ddd>\", where I<ddd> is a decimal "
8844 "number of up to three digits in the range 0 to 255. The address is "
8845 "converted to a I<struct in_addr> and copied to I<dst>, which must be "
8846 "I<sizeof(struct in_addr)> (4) bytes (32 bits) long."
8850 #: build/C/man3/inet_pton.3:79
8852 "I<src> points to a character string containing an IPv6 network address. The "
8853 "address is converted to a I<struct in6_addr> and copied to I<dst>, which "
8854 "must be I<sizeof(struct in6_addr)> (16) bytes (128 bits) long. The allowed "
8855 "formats for IPv6 addresses follow these rules:"
8859 #: build/C/man3/inet_pton.3:80
8865 #: build/C/man3/inet_pton.3:87
8867 "The preferred format is I<x:x:x:x:x:x:x:x>. This form consists of eight "
8868 "hexadecimal numbers, each of which expresses a 16-bit value (i.e., each I<x> "
8869 "can be up to 4 hex digits)."
8873 #: build/C/man3/inet_pton.3:87
8879 #: build/C/man3/inet_pton.3:100
8881 "A series of contiguous zero values in the preferred format can be "
8882 "abbreviated to I<::>. Only one instance of I<::> can occur in an address. "
8883 "For example, the loopback address I<0:0:0:0:0:0:0:1> can be abbreviated as "
8884 "I<::1>. The wildcard address, consisting of all zeros, can be written as "
8889 #: build/C/man3/inet_pton.3:100
8895 #: build/C/man3/inet_pton.3:113
8897 "An alternate format is useful for expressing IPv4-mapped IPv6 addresses. "
8898 "This form is written as I<x:x:x:x:x:x:d.d.d.d>, where the six leading I<x>s "
8899 "are hexadecimal values that define the six most-significant 16-bit pieces of "
8900 "the address (i.e., 96 bits), and the I<d>s express a value in dotted-decimal "
8901 "notation that defines the least significant 32 bits of the address. An "
8902 "example of such an address is I<::FFFF:204.152.189.116>."
8906 #: build/C/man3/inet_pton.3:116
8907 msgid "See RFC 2373 for further details on the representation of IPv6 addresses."
8911 #: build/C/man3/inet_pton.3:129
8913 "B<inet_pton>() returns 1 on success (network address was successfully "
8914 "converted). 0 is returned if I<src> does not contain a character string "
8915 "representing a valid network address in the specified address family. If "
8916 "I<af> does not contain a valid address family, -1 is returned and I<errno> "
8917 "is set to B<EAFNOSUPPORT>."
8921 #: build/C/man3/inet_pton.3:150
8923 "Unlike B<inet_aton>(3) and B<inet_addr>(3), B<inet_pton>() supports IPv6 "
8924 "addresses. On the other hand, B<inet_pton>() accepts only IPv4 addresses "
8925 "in dotted-decimal notation, whereas B<inet_aton>(3) and B<inet_addr>(3) "
8926 "allow the more general numbers-and-dots notation (hexadecimal and octal "
8927 "number formats, and formats that don't require all four bytes to be "
8928 "explicitly written). For an interface that handles both IPv6 addresses, and "
8929 "IPv4 addresses in numbers-and-dots notation, see B<getaddrinfo>(3)."
8933 #: build/C/man3/inet_pton.3:156
8935 "B<AF_INET6> does not recognize IPv4 addresses. An explicit IPv4-mapped IPv6 "
8936 "address must be supplied in I<src> instead."
8940 #: build/C/man3/inet_pton.3:162
8942 "The program below demonstrates the use of B<inet_pton>() and "
8943 "B<inet_ntop>(3). Here are some example runs:"
8947 #: build/C/man3/inet_pton.3:171
8950 "$B< ./a.out i6 0:0:0:0:0:0:0:0>\n"
8952 "$B< ./a.out i6 1:0:0:0:0:0:0:8>\n"
8954 "$B< ./a.out i6 0:0:0:0:0:FFFF:204.152.189.116>\n"
8955 "::ffff:204.152.189.116\n"
8959 #: build/C/man3/inet_pton.3:180
8962 "#include E<lt>arpa/inet.hE<gt>\n"
8963 "#include E<lt>stdio.hE<gt>\n"
8964 "#include E<lt>stdlib.hE<gt>\n"
8965 "#include E<lt>string.hE<gt>\n"
8969 #: build/C/man3/inet_pton.3:187
8973 "main(int argc, char *argv[])\n"
8975 " unsigned char buf[sizeof(struct in6_addr)];\n"
8977 " char str[INET6_ADDRSTRLEN];\n"
8981 #: build/C/man3/inet_pton.3:192
8984 " if (argc != 3) {\n"
8985 " fprintf(stderr, \"Usage: %s {i4|i6|E<lt>numE<gt>} string\\en\", "
8987 " exit(EXIT_FAILURE);\n"
8992 #: build/C/man3/inet_pton.3:195
8995 " domain = (strcmp(argv[1], \"i4\") == 0) ? AF_INET :\n"
8996 " (strcmp(argv[1], \"i6\") == 0) ? AF_INET6 : atoi(argv[1]);\n"
9000 #: build/C/man3/inet_pton.3:204
9003 " s = inet_pton(domain, argv[2], buf);\n"
9004 " if (s E<lt>= 0) {\n"
9006 " fprintf(stderr, \"Not in presentation format\");\n"
9008 " perror(\"inet_pton\");\n"
9009 " exit(EXIT_FAILURE);\n"
9014 #: build/C/man3/inet_pton.3:209
9017 " if (inet_ntop(domain, buf, str, INET6_ADDRSTRLEN) == NULL) {\n"
9018 " perror(\"inet_ntop\");\n"
9019 " exit(EXIT_FAILURE);\n"
9024 #: build/C/man3/inet_pton.3:211
9026 msgid " printf(\"%s\\en\", str);\n"
9030 #: build/C/man3/inet_pton.3:218
9031 msgid "B<getaddrinfo>(3), B<inet>(3), B<inet_ntop>(3)"
9035 #: build/C/man7/ip.7:36
9041 #: build/C/man7/ip.7:36
9047 #: build/C/man7/ip.7:39
9048 msgid "ip - Linux IPv4 protocol implementation"
9052 #: build/C/man7/ip.7:45 build/C/man7/ipv6.7:93 build/C/man7/raw.7:20 build/C/man7/tcp.7:83 build/C/man7/udp.7:19
9053 msgid "B<#include E<lt>netinet/in.hE<gt>>"
9057 #: build/C/man7/ip.7:47
9058 msgid "B<#include E<lt>netinet/ip.hE<gt> >/* superset of previous */"
9062 #: build/C/man7/ip.7:49
9063 msgid "I<tcp_socket>B< = socket(AF_INET, SOCK_STREAM, 0);>"
9067 #: build/C/man7/ip.7:51
9068 msgid "I<udp_socket>B< = socket(AF_INET, SOCK_DGRAM, 0);>"
9072 #: build/C/man7/ip.7:53
9073 msgid "I<raw_socket>B< = socket(AF_INET, SOCK_RAW, >I<protocol>B<);>"
9076 #. FIXME . has someone verified that 2.1 is really 1812 compliant?
9078 #: build/C/man7/ip.7:60
9080 "Linux implements the Internet Protocol, version 4, described in RFC\\ 791 "
9081 "and RFC\\ 1122. B<ip> contains a level 2 multicasting implementation "
9082 "conforming to RFC\\ 1112. It also contains an IP router including a packet "
9087 #: build/C/man7/ip.7:64
9089 "The programming interface is BSD-sockets compatible. For more information "
9090 "on sockets, see B<socket>(7)."
9094 #: build/C/man7/ip.7:95
9096 "An IP socket is created by calling the B<socket>(2) function as "
9097 "B<socket(AF_INET, >I<socket_type>B<, >I<protocol>B<)>. Valid socket types "
9098 "are B<SOCK_STREAM> to open a B<tcp>(7) socket, B<SOCK_DGRAM> to open a "
9099 "B<udp>(7) socket, or B<SOCK_RAW> to open a B<raw>(7) socket to access the "
9100 "IP protocol directly. I<protocol> is the IP protocol in the IP header to be "
9101 "received or sent. The only valid values for I<protocol> are 0 and "
9102 "B<IPPROTO_TCP> for TCP sockets, and 0 and B<IPPROTO_UDP> for UDP sockets. "
9103 "For B<SOCK_RAW> you may specify a valid IANA IP protocol defined in RFC\\ "
9104 "1700 assigned numbers."
9108 #: build/C/man7/ip.7:117
9110 "When a process wants to receive new incoming packets or connections, it "
9111 "should bind a socket to a local interface address using B<bind>(2). In this "
9112 "case, only one IP socket may be bound to any given local (address, port) "
9113 "pair. When B<INADDR_ANY> is specified in the bind call, the socket will be "
9114 "bound to I<all> local interfaces. When B<listen>(2) is called on an "
9115 "unbound socket, the socket is automatically bound to a random free port with "
9116 "the local address set to B<INADDR_ANY>. When B<connect>(2) is called on an "
9117 "unbound socket, the socket is automatically bound to a random free port or "
9118 "to a usable shared port with the local address set to B<INADDR_ANY>."
9122 #: build/C/man7/ip.7:123
9124 "A TCP local socket address that has been bound is unavailable for some time "
9125 "after closing, unless the B<SO_REUSEADDR> flag has been set. Care should be "
9126 "taken when using this flag as it makes TCP less reliable."
9130 #: build/C/man7/ip.7:134
9132 "An IP socket address is defined as a combination of an IP interface address "
9133 "and a 16-bit port number. The basic IP protocol does not supply port "
9134 "numbers, they are implemented by higher level protocols like B<udp>(7) and "
9135 "B<tcp>(7). On raw sockets I<sin_port> is set to the IP protocol."
9139 #: build/C/man7/ip.7:142
9142 "struct sockaddr_in {\n"
9143 " sa_family_t sin_family; /* address family: AF_INET */\n"
9144 " in_port_t sin_port; /* port in network byte order */\n"
9145 " struct in_addr sin_addr; /* internet address */\n"
9150 #: build/C/man7/ip.7:147
9153 "/* Internet address. */\n"
9154 "struct in_addr {\n"
9155 " uint32_t s_addr; /* address in network byte order */\n"
9160 #: build/C/man7/ip.7:172
9162 "I<sin_family> is always set to B<AF_INET>. This is required; in Linux 2.2 "
9163 "most networking functions return B<EINVAL> when this setting is missing. "
9164 "I<sin_port> contains the port in network byte order. The port numbers below "
9165 "1024 are called I<privileged ports> (or sometimes: I<reserved ports>). Only "
9166 "privileged processes (i.e., those having the B<CAP_NET_BIND_SERVICE> "
9167 "capability) may B<bind>(2) to these sockets. Note that the raw IPv4 "
9168 "protocol as such has no concept of a port, they are implemented only by "
9169 "higher protocols like B<tcp>(7) and B<udp>(7)."
9173 #: build/C/man7/ip.7:191
9175 "I<sin_addr> is the IP host address. The I<s_addr> member of I<struct "
9176 "in_addr> contains the host interface address in network byte order. "
9177 "I<in_addr> should be assigned one of the B<INADDR_*> values (e.g., "
9178 "B<INADDR_ANY>) or set using the B<inet_aton>(3), B<inet_addr>(3), "
9179 "B<inet_makeaddr>(3) library functions or directly with the name resolver "
9180 "(see B<gethostbyname>(3))."
9183 #. Leave a loophole for XTP @)
9185 #: build/C/man7/ip.7:203
9187 "IPv4 addresses are divided into unicast, broadcast and multicast addresses. "
9188 "Unicast addresses specify a single interface of a host, broadcast addresses "
9189 "specify all hosts on a network and multicast addresses address all hosts in "
9190 "a multicast group. Datagrams to broadcast addresses can be sent or received "
9191 "only when the B<SO_BROADCAST> socket flag is set. In the current "
9192 "implementation, connection-oriented sockets are allowed to use only unicast "
9197 #: build/C/man7/ip.7:211
9199 "Note that the address and the port are always stored in network byte order. "
9200 "In particular, this means that you need to call B<htons>(3) on the number "
9201 "that is assigned to a port. All address/port manipulation functions in the "
9202 "standard library work in network byte order."
9206 #: build/C/man7/ip.7:224
9208 "There are several special addresses: B<INADDR_LOOPBACK> (127.0.0.1) always "
9209 "refers to the local host via the loopback device; B<INADDR_ANY> (0.0.0.0) "
9210 "means any address for binding; B<INADDR_BROADCAST> (255.255.255.255) means "
9211 "any host and has the same effect on bind as B<INADDR_ANY> for historical "
9215 #. or SOL_IP on Linux
9217 #: build/C/man7/ip.7:233
9219 "IP supports some protocol-specific socket options that can be set with "
9220 "B<setsockopt>(2) and read with B<getsockopt>(2). The socket option level "
9221 "for IP is B<IPPROTO_IP>. A boolean integer flag is zero when it is false, "
9226 #: build/C/man7/ip.7:233
9228 msgid "B<IP_ADD_MEMBERSHIP> (since Linux 1.2)"
9232 #: build/C/man7/ip.7:239
9233 msgid "Join a multicast group. Argument is an I<ip_mreqn> structure."
9237 #: build/C/man7/ip.7:249
9240 "struct ip_mreqn {\n"
9241 " struct in_addr imr_multiaddr; /* IP multicast group\n"
9243 " struct in_addr imr_address; /* IP address of local\n"
9245 " int imr_ifindex; /* interface index */\n"
9249 #. (i.e., within the 224.0.0.0-239.255.255.255 range)
9251 #: build/C/man7/ip.7:270
9253 "I<imr_multiaddr> contains the address of the multicast group the application "
9254 "wants to join or leave. It must be a valid multicast address (or "
9255 "B<setsockopt>(2) fails with the error B<EINVAL>). I<imr_address> is the "
9256 "address of the local interface with which the system should join the "
9257 "multicast group; if it is equal to B<INADDR_ANY>, an appropriate interface "
9258 "is chosen by the system. I<imr_ifindex> is the interface index of the "
9259 "interface that should join/leave the I<imr_multiaddr> group, or 0 to "
9260 "indicate any interface."
9264 #: build/C/man7/ip.7:285
9266 "The I<ip_mreqn> structure is available only since Linux 2.2. For "
9267 "compatibility, the old I<ip_mreq> structure (present since Linux 1.2) is "
9268 "still supported; it differs from I<ip_mreqn> only by not including the "
9269 "I<imr_ifindex> field. Only valid as a B<setsockopt>(2)."
9273 #: build/C/man7/ip.7:285
9275 msgid "B<IP_ADD_SOURCE_MEMBERSHIP> (since Linux 2.4.22 / 2.5.68)"
9279 #: build/C/man7/ip.7:292
9281 "Join a multicast group and allow receiving data only from a specified "
9282 "source. Argument is an I<ip_mreq_source> structure."
9286 #: build/C/man7/ip.7:303
9289 "struct ip_mreq_source {\n"
9290 " struct in_addr imr_multiaddr; /* IP multicast group\n"
9292 " struct in_addr imr_interface; /* IP address of local\n"
9294 " struct in_addr imr_sourceaddr; /* IP address of\n"
9295 " multicast source */\n"
9300 #: build/C/man7/ip.7:324
9302 "The I<ip_mreq_source> structure is similar to I<ip_mreqn> described under "
9303 "B<IP_ADD_MEMBERSIP>. The I<imr_multiaddr> field contains the address of the "
9304 "multicast group the application wants to join or leave. The "
9305 "I<imr_interface> field is the address of the local interface with which the "
9306 "system should join the multicast group. Finally, the I<imr_sourceaddr> "
9307 "field contains the address of the source the application wants to receive "
9312 #: build/C/man7/ip.7:327
9314 "This option can be used multiple times to allow receiving data from more "
9319 #: build/C/man7/ip.7:327
9321 msgid "B<IP_BLOCK_SOURCE> (since Linux 2.4.22 / 2.5.68)"
9325 #: build/C/man7/ip.7:335
9327 "Stop receiving multicast data from a specific source in a given group. This "
9328 "is valid only after the application has subscribed to the multicast group "
9329 "using either B<IP_ADD_MEMBERSHIP> or B<IP_ADD_SOURCE_MEMBERSHIP>."
9333 #: build/C/man7/ip.7:340 build/C/man7/ip.7:362 build/C/man7/ip.7:926
9335 "Argument is an I<ip_mreq_source> structure as described under "
9336 "B<IP_ADD_SOURCE_MEMBERSHIP>."
9340 #: build/C/man7/ip.7:340
9342 msgid "B<IP_DROP_MEMBERSHIP> (since Linux 1.2)"
9346 #: build/C/man7/ip.7:349
9348 "Leave a multicast group. Argument is an I<ip_mreqn> or I<ip_mreq> structure "
9349 "similar to B<IP_ADD_MEMBERSHIP>."
9353 #: build/C/man7/ip.7:349
9355 msgid "B<IP_DROP_SOURCE_MEMBERSHIP> (since Linux 2.4.22 / 2.5.68)"
9359 #: build/C/man7/ip.7:357
9361 "Leave a source-specific group\\(emthat is, stop receiving data from a given "
9362 "multicast group that come from a given source. If the application has "
9363 "subscribed to multiple sources within the same group, data from the "
9364 "remaining sources will still be delivered. To stop receiving data from all "
9365 "sources at once, use B<IP_LEAVE_GROUP>."
9369 #: build/C/man7/ip.7:362
9371 msgid "B<IP_FREEBIND> (since Linux 2.4)"
9374 #. Precisely: 2.4.0-test10
9376 #: build/C/man7/ip.7:375
9378 "If enabled, this boolean option allows binding to an IP address that is "
9379 "nonlocal or does not (yet) exist. This permits listening on a socket, "
9380 "without requiring the underlying network interface or the specified dynamic "
9381 "IP address to be up at the time that the application is trying to bind to "
9382 "it. This option is the per-socket equivalent of the I<ip_nonlocal_bind> "
9383 "I</proc> interface described below."
9387 #: build/C/man7/ip.7:375
9389 msgid "B<IP_HDRINCL> (since Linux 2.0)"
9393 #: build/C/man7/ip.7:391
9395 "If enabled, the user supplies an IP header in front of the user data. Only "
9396 "valid for B<SOCK_RAW> sockets. See B<raw>(7) for more information. When "
9397 "this flag is enabled the values set by B<IP_OPTIONS>, B<IP_TTL> and "
9398 "B<IP_TOS> are ignored."
9402 #: build/C/man7/ip.7:391
9404 msgid "B<IP_MSFILTER> (since Linux 2.4.22 / 2.5.68)"
9408 #: build/C/man7/ip.7:397
9410 "This option provides access to the advanced full-state filtering API. "
9411 "Argument is an I<ip_msfilter> structure."
9415 #: build/C/man7/ip.7:406
9418 "struct ip_msfilter {\n"
9419 " struct in_addr imsf_multiaddr; /* IP multicast group\n"
9421 " struct in_addr imsf_interface; /* IP address of local\n"
9423 " uint32_t imsf_fmode; /* Filter-mode */\n"
9427 #: build/C/man7/ip.7:412
9430 " uint32_t imsf_numsrc; /* Number of sources in\n"
9431 " the following array */\n"
9432 " struct in_addr imsf_slist[1]; /* Array of source\n"
9438 #: build/C/man7/ip.7:427
9440 "There are two macros, B<MCAST_INCLUDE> and B<MCAST_EXCLUDE>, which can be "
9441 "used to specify the filtering mode. Additionally, the "
9442 "B<IP_MSFILTER_SIZE>(n) macro exists to determine how much memory is needed "
9443 "to store I<ip_msfilter> structure with I<n> sources in the source list."
9447 #: build/C/man7/ip.7:430
9448 msgid "For the full description of multicast source filtering refer to RFC 3376."
9452 #: build/C/man7/ip.7:430
9454 msgid "B<IP_MTU> (since Linux 2.2)"
9457 #. Precisely: 2.1.124
9459 #: build/C/man7/ip.7:438
9461 "Retrieve the current known path MTU of the current socket. Valid only when "
9462 "the socket has been connected. Returns an integer. Only valid as a "
9467 #: build/C/man7/ip.7:438
9469 msgid "B<IP_MTU_DISCOVER> (since Linux 2.2)"
9472 #. Precisely: 2.1.124
9474 #: build/C/man7/ip.7:459
9476 "Set or receive the Path MTU Discovery setting for a socket. When enabled, "
9477 "Linux will perform Path MTU Discovery as defined in RFC\\ 1191 on "
9478 "B<SOCK_STREAM> sockets. For non-B<SOCK_STREAM> sockets, B<IP_PMTUDISC_DO> "
9479 "forces the don't-fragment flag to be set on all outgoing packets. It is the "
9480 "user's responsibility to packetize the data in MTU-sized chunks and to do "
9481 "the retransmits if necessary. The kernel will reject (with B<EMSGSIZE>) "
9482 "datagrams that are bigger than the known path MTU. B<IP_PMTUDISC_WANT> will "
9483 "fragment a datagram if needed according to the path MTU, or will set the "
9484 "don't-fragment flag otherwise."
9488 #: build/C/man7/ip.7:467
9490 "The system-wide default can be toggled between B<IP_PMTUDISC_WANT> and "
9491 "B<IP_PMTUDISC_DONT> by writing (respectively, zero and nonzero values) to "
9492 "the I</proc/sys/net/ipv4/ip_no_pmtu_disc> file."
9496 #: build/C/man7/ip.7:471
9498 msgid "Path MTU discovery value:Meaning\n"
9502 #: build/C/man7/ip.7:472
9504 msgid "IP_PMTUDISC_WANT:Use per-route settings.\n"
9508 #: build/C/man7/ip.7:473
9510 msgid "IP_PMTUDISC_DONT:Never do Path MTU Discovery.\n"
9514 #: build/C/man7/ip.7:474
9516 msgid "IP_PMTUDISC_DO:Always do Path MTU Discovery.\n"
9520 #: build/C/man7/ip.7:475
9522 msgid "IP_PMTUDISC_PROBE:Set DF but ignore Path MTU.\n"
9526 #: build/C/man7/ip.7:493
9528 "When PMTU discovery is enabled, the kernel automatically keeps track of the "
9529 "path MTU per destination host. When it is connected to a specific peer with "
9530 "B<connect>(2), the currently known path MTU can be retrieved conveniently "
9531 "using the B<IP_MTU> socket option (e.g., after an B<EMSGSIZE> error "
9532 "occurred). The path MTU may change over time. For connectionless sockets "
9533 "with many destinations, the new MTU for a given destination can also be "
9534 "accessed using the error queue (see B<IP_RECVERR>). A new error will be "
9535 "queued for every incoming MTU update."
9539 #: build/C/man7/ip.7:498
9541 "While MTU discovery is in progress, initial packets from datagram sockets "
9542 "may be dropped. Applications using UDP should be aware of this and not take "
9543 "it into account for their packet retransmit strategy."
9546 #. FIXME . this is an ugly hack
9548 #: build/C/man7/ip.7:503
9550 "To bootstrap the path MTU discovery process on unconnected sockets, it is "
9551 "possible to start with a big datagram size (up to 64K-headers bytes long) "
9552 "and let it shrink by updates of the path MTU."
9556 #: build/C/man7/ip.7:512
9558 "To get an initial estimate of the path MTU, connect a datagram socket to the "
9559 "destination address using B<connect>(2) and retrieve the MTU by calling "
9560 "B<getsockopt>(2) with the B<IP_MTU> option."
9564 #: build/C/man7/ip.7:524
9566 "It is possible to implement RFC 4821 MTU probing with B<SOCK_DGRAM> or "
9567 "B<SOCK_RAW> sockets by setting a value of B<IP_PMTUDISC_PROBE> (available "
9568 "since Linux 2.6.22). This is also particularly useful for diagnostic tools "
9569 "such as B<tracepath>(8) that wish to deliberately send probe packets larger "
9570 "than the observed Path MTU."
9574 #: build/C/man7/ip.7:524
9576 msgid "B<IP_MULTICAST_ALL> (since Linux 2.6.31)"
9580 #: build/C/man7/ip.7:538
9582 "This option can be used to modify the delivery policy of multicast messages "
9583 "to sockets bound to the wildcard B<INADDR_ANY> address. The argument is a "
9584 "boolean integer (defaults to 1). If set to 1, the socket will receive "
9585 "messages from all the groups that have been joined globally on the whole "
9586 "system. Otherwise, it will deliver messages only from the groups that have "
9587 "been explicitly joined (for example via the B<IP_ADD_MEMBERSHIP> option) on "
9588 "this particular socket."
9592 #: build/C/man7/ip.7:538
9594 msgid "B<IP_MULTICAST_IF> (since Linux 1.2)"
9597 #. net: IP_MULTICAST_IF setsockopt now recognizes struct mreq
9598 #. Commit: 3a084ddb4bf299a6e898a9a07c89f3917f0713f7
9600 #: build/C/man7/ip.7:550
9602 "Set the local device for a multicast socket. Argument is an I<ip_mreqn> or "
9603 "I<ip_mreq> (since Linux 3.5) structure similar to B<IP_ADD_MEMBERSHIP>."
9607 #: build/C/man7/ip.7:554
9608 msgid "When an invalid socket option is passed, B<ENOPROTOOPT> is returned."
9612 #: build/C/man7/ip.7:554
9614 msgid "B<IP_MULTICAST_LOOP> (since Linux 1.2)"
9618 #: build/C/man7/ip.7:558
9620 "Set or read a boolean integer argument that determines whether sent "
9621 "multicast packets should be looped back to the local sockets."
9625 #: build/C/man7/ip.7:558
9627 msgid "B<IP_MULTICAST_TTL> (since Linux 1.2)"
9631 #: build/C/man7/ip.7:566
9633 "Set or read the time-to-live value of outgoing multicast packets for this "
9634 "socket. It is very important for multicast packets to set the smallest TTL "
9635 "possible. The default is 1 which means that multicast packets don't leave "
9636 "the local network unless the user program explicitly requests it. Argument "
9641 #: build/C/man7/ip.7:566
9643 msgid "B<IP_NODEFRAG> (since Linux 2.6.36)"
9647 #: build/C/man7/ip.7:574
9649 "If enabled (argument is nonzero), the reassembly of outgoing packets is "
9650 "disabled in the netfilter layer. This option is valid only for B<SOCK_RAW> "
9651 "sockets. The argument is an integer."
9655 #: build/C/man7/ip.7:574
9657 msgid "B<IP_OPTIONS> (since Linux 2.0)"
9660 #. Precisely: 1.3.30
9662 #: build/C/man7/ip.7:603
9664 "Set or get the IP options to be sent with every packet from this socket. "
9665 "The arguments are a pointer to a memory buffer containing the options and "
9666 "the option length. The B<setsockopt>(2) call sets the IP options "
9667 "associated with a socket. The maximum option size for IPv4 is 40 bytes. "
9668 "See RFC\\ 791 for the allowed options. When the initial connection request "
9669 "packet for a B<SOCK_STREAM> socket contains IP options, the IP options will "
9670 "be set automatically to the options from the initial packet with routing "
9671 "headers reversed. Incoming packets are not allowed to change options after "
9672 "the connection is established. The processing of all incoming source "
9673 "routing options is disabled by default and can be enabled by using the "
9674 "I<accept_source_route> I</proc> interface. Other options like timestamps "
9675 "are still handled. For datagram sockets, IP options can be only set by the "
9676 "local user. Calling B<getsockopt>(2) with B<IP_OPTIONS> puts the current "
9677 "IP options used for sending into the supplied buffer."
9681 #: build/C/man7/ip.7:603
9683 msgid "B<IP_PKTINFO> (since Linux 2.2)"
9686 #. Precisely: 2.1.68
9688 #: build/C/man7/ip.7:620
9690 "Pass an B<IP_PKTINFO> ancillary message that contains a I<pktinfo> structure "
9691 "that supplies some information about the incoming packet. This only works "
9692 "for datagram oriented sockets. The argument is a flag that tells the socket "
9693 "whether the B<IP_PKTINFO> message should be passed or not. The message "
9694 "itself can only be sent/retrieved as control message with a packet using "
9695 "B<recvmsg>(2) or B<sendmsg>(2)."
9699 #: build/C/man7/ip.7:629
9702 "struct in_pktinfo {\n"
9703 " unsigned int ipi_ifindex; /* Interface index */\n"
9704 " struct in_addr ipi_spec_dst; /* Local address */\n"
9705 " struct in_addr ipi_addr; /* Header Destination\n"
9710 #. FIXME . elaborate on that.
9711 #. This field is grossly misnamed
9713 #: build/C/man7/ip.7:654
9715 "I<ipi_ifindex> is the unique index of the interface the packet was received "
9716 "on. I<ipi_spec_dst> is the local address of the packet and I<ipi_addr> is "
9717 "the destination address in the packet header. If B<IP_PKTINFO> is passed to "
9718 "B<sendmsg>(2) and I<ipi_spec_dst> is not zero, then it is used as the local "
9719 "source address for the routing table lookup and for setting up IP source "
9720 "route options. When I<ipi_ifindex> is not zero, the primary local address "
9721 "of the interface specified by the index overwrites I<ipi_spec_dst> for the "
9722 "routing table lookup."
9726 #: build/C/man7/ip.7:654
9728 msgid "B<IP_RECVERR> (since Linux 2.2)"
9731 #. Precisely: 2.1.15
9732 #. or SOL_IP on Linux
9734 #: build/C/man7/ip.7:676
9736 "Enable extended reliable error message passing. When enabled on a datagram "
9737 "socket, all generated errors will be queued in a per-socket error queue. "
9738 "When the user receives an error from a socket operation, the errors can be "
9739 "received by calling B<recvmsg>(2) with the B<MSG_ERRQUEUE> flag set. The "
9740 "I<sock_extended_err> structure describing the error will be passed in an "
9741 "ancillary message with the type B<IP_RECVERR> and the level B<IPPROTO_IP>. "
9742 "This is useful for reliable error handling on unconnected sockets. The "
9743 "received data portion of the error queue contains the error packet."
9747 #: build/C/man7/ip.7:682
9748 msgid "The B<IP_RECVERR> control message contains a I<sock_extended_err> structure:"
9752 #: build/C/man7/ip.7:690
9755 "#define SO_EE_ORIGIN_NONE 0\n"
9756 "#define SO_EE_ORIGIN_LOCAL 1\n"
9757 "#define SO_EE_ORIGIN_ICMP 2\n"
9758 "#define SO_EE_ORIGIN_ICMP6 3\n"
9762 #: build/C/man7/ip.7:701
9765 "struct sock_extended_err {\n"
9766 " uint32_t ee_errno; /* error number */\n"
9767 " uint8_t ee_origin; /* where the error originated */\n"
9768 " uint8_t ee_type; /* type */\n"
9769 " uint8_t ee_code; /* code */\n"
9770 " uint8_t ee_pad;\n"
9771 " uint32_t ee_info; /* additional information */\n"
9772 " uint32_t ee_data; /* other data */\n"
9773 " /* More data may follow */\n"
9778 #: build/C/man7/ip.7:703
9780 msgid "struct sockaddr *SO_EE_OFFENDER(struct sock_extended_err *);\n"
9784 #: build/C/man7/ip.7:726
9786 "I<ee_errno> contains the I<errno> number of the queued error. I<ee_origin> "
9787 "is the origin code of where the error originated. The other fields are "
9788 "protocol-specific. The macro B<SO_EE_OFFENDER> returns a pointer to the "
9789 "address of the network object where the error originated from given a "
9790 "pointer to the ancillary message. If this address is not known, the "
9791 "I<sa_family> member of the I<sockaddr> contains B<AF_UNSPEC> and the other "
9792 "fields of the I<sockaddr> are undefined."
9795 #. FIXME . Is it a good idea to document that? It is a dubious feature.
9800 #. has slightly different semantics. Instead of
9801 #. saving the errors for the next timeout, it passes all incoming
9802 #. errors immediately to the user.
9803 #. This might be useful for very short-lived TCP connections which
9804 #. need fast error handling. Use this option with care:
9805 #. it makes TCP unreliable
9806 #. by not allowing it to recover properly from routing
9807 #. shifts and other normal
9808 #. conditions and breaks the protocol specification.
9810 #: build/C/man7/ip.7:785
9812 "IP uses the I<sock_extended_err> structure as follows: I<ee_origin> is set "
9813 "to B<SO_EE_ORIGIN_ICMP> for errors received as an ICMP packet, or "
9814 "B<SO_EE_ORIGIN_LOCAL> for locally generated errors. Unknown values should "
9815 "be ignored. I<ee_type> and I<ee_code> are set from the type and code fields "
9816 "of the ICMP header. I<ee_info> contains the discovered MTU for B<EMSGSIZE> "
9817 "errors. The message also contains the I<sockaddr_in of the node> caused the "
9818 "error, which can be accessed with the B<SO_EE_OFFENDER> macro. The "
9819 "I<sin_family> field of the B<SO_EE_OFFENDER> address is B<AF_UNSPEC> when "
9820 "the source was unknown. When the error originated from the network, all IP "
9821 "options (B<IP_OPTIONS>, B<IP_TTL>, etc.) enabled on the socket and contained "
9822 "in the error packet are passed as control messages. The payload of the "
9823 "packet causing the error is returned as normal payload. Note that TCP has "
9824 "no error queue; B<MSG_ERRQUEUE> is not permitted on B<SOCK_STREAM> sockets. "
9825 "B<IP_RECVERR> is valid for TCP, but all errors are returned by socket "
9826 "function return or B<SO_ERROR> only."
9830 #: build/C/man7/ip.7:790
9832 "For raw sockets, B<IP_RECVERR> enables passing of all received ICMP errors "
9833 "to the application, otherwise errors are only reported on connected sockets"
9837 #: build/C/man7/ip.7:794
9839 "It sets or retrieves an integer boolean flag. B<IP_RECVERR> defaults to "
9844 #: build/C/man7/ip.7:794
9846 msgid "B<IP_RECVOPTS> (since Linux 2.2)"
9849 #. Precisely: 2.1.15
9851 #: build/C/man7/ip.7:805
9853 "Pass all incoming IP options to the user in a B<IP_OPTIONS> control "
9854 "message. The routing header and other options are already filled in for the "
9855 "local host. Not supported for B<SOCK_STREAM> sockets."
9859 #: build/C/man7/ip.7:805
9861 msgid "B<IP_RECVORIGDSTADDR> (since Linux 2.6.29)"
9864 #. commit e8b2dfe9b4501ed0047459b2756ba26e5a940a69
9866 #: build/C/man7/ip.7:816
9868 "This boolean option enables the B<IP_ORIGDSTADDR> ancillary message in "
9869 "B<recvmsg>(2), in which the kernel returns the original destination address "
9870 "of the datagram being received. The ancillary message contains a I<struct "
9875 #: build/C/man7/ip.7:816
9877 msgid "B<IP_RECVTOS> (since Linux 2.2)"
9880 #. Precisely: 2.1.68
9882 #: build/C/man7/ip.7:825
9884 "If enabled, the B<IP_TOS> ancillary message is passed with incoming "
9885 "packets. It contains a byte which specifies the Type of Service/Precedence "
9886 "field of the packet header. Expects a boolean integer flag."
9890 #: build/C/man7/ip.7:825
9892 msgid "B<IP_RECVTTL> (since Linux 2.2)"
9895 #. Precisely: 2.1.68
9897 #: build/C/man7/ip.7:835
9899 "When this flag is set, pass a B<IP_TTL> control message with the time to "
9900 "live field of the received packet as a byte. Not supported for "
9901 "B<SOCK_STREAM> sockets."
9905 #: build/C/man7/ip.7:835
9907 msgid "B<IP_RETOPTS> (since Linux 2.2)"
9910 #. Precisely: 2.1.15
9912 #: build/C/man7/ip.7:842
9914 "Identical to B<IP_RECVOPTS>, but returns raw unprocessed options with "
9915 "timestamp and route record options not filled in for this hop."
9919 #: build/C/man7/ip.7:842
9921 msgid "B<IP_ROUTER_ALERT> (since Linux 2.2)"
9924 #. Precisely: 2.1.68
9926 #: build/C/man7/ip.7:854
9928 "Pass all to-be forwarded packets with the IP Router Alert option set to this "
9929 "socket. Only valid for raw sockets. This is useful, for instance, for "
9930 "user-space RSVP daemons. The tapped packets are not forwarded by the "
9931 "kernel; it is the user's responsibility to send them out again. Socket "
9932 "binding is ignored, such packets are only filtered by protocol. Expects an "
9937 #: build/C/man7/ip.7:854
9939 msgid "B<IP_TOS> (since Linux 1.0)"
9942 #. FIXME elaborate on this
9943 #. Needs CAP_NET_ADMIN
9945 #. Since Linux 2.6.27
9946 #. Author: KOVACS Krisztian <hidden@sch.bme.hu>
9947 #. http://lwn.net/Articles/252545/
9949 #: build/C/man7/ip.7:888
9951 "Set or receive the Type-Of-Service (TOS) field that is sent with every IP "
9952 "packet originating from this socket. It is used to prioritize packets on "
9953 "the network. TOS is a byte. There are some standard TOS flags defined: "
9954 "B<IPTOS_LOWDELAY> to minimize delays for interactive traffic, "
9955 "B<IPTOS_THROUGHPUT> to optimize throughput, B<IPTOS_RELIABILITY> to optimize "
9956 "for reliability, B<IPTOS_MINCOST> should be used for \"filler data\" where "
9957 "slow transmission doesn't matter. At most one of these TOS values can be "
9958 "specified. Other bits are invalid and shall be cleared. Linux sends "
9959 "B<IPTOS_LOWDELAY> datagrams first by default, but the exact behavior depends "
9960 "on the configured queueing discipline. Some high priority levels may "
9961 "require superuser privileges (the B<CAP_NET_ADMIN> capability). The "
9962 "priority can also be set in a protocol independent way by the "
9963 "(B<SOL_SOCKET>, B<SO_PRIORITY>) socket option (see B<socket>(7))."
9967 #: build/C/man7/ip.7:888
9969 msgid "B<IP_TRANSPARENT> (since Linux 2.6.24)"
9972 #. commit f5715aea4564f233767ea1d944b2637a5fd7cd2e
9973 #. This patch introduces the IP_TRANSPARENT socket option: enabling that
9974 #. will make the IPv4 routing omit the non-local source address check on
9975 #. output. Setting IP_TRANSPARENT requires NET_ADMIN capability.
9976 #. http://lwn.net/Articles/252545/
9978 #: build/C/man7/ip.7:908
9980 "Setting this boolean option enables transparent proxying on this socket. "
9981 "This socket option allows the calling application to bind to a nonlocal IP "
9982 "address and operate both as a client and a server with the foreign address "
9983 "as the local endpoint. NOTE: this requires that routing be set up in a way "
9984 "that packets going to the foreign address are routed through the TProxy box "
9985 "(i.e., the system hosting the application that employs the B<IP_TRANSPARENT> "
9986 "socket option). Enabling this socket option requires superuser privileges "
9987 "(the B<CAP_NET_ADMIN> capability)."
9991 #: build/C/man7/ip.7:911
9993 "TProxy redirection with the iptables TPROXY target also requires that this "
9994 "option be set on the redirected socket."
9998 #: build/C/man7/ip.7:911
10000 msgid "B<IP_TTL> (since Linux 1.0)"
10003 #. type: Plain text
10004 #: build/C/man7/ip.7:915
10006 "Set or retrieve the current time-to-live field that is used in every packet "
10007 "sent from this socket."
10011 #: build/C/man7/ip.7:915
10013 msgid "B<IP_UNBLOCK_SOURCE> (since Linux 2.4.22 / 2.5.68)"
10016 #. type: Plain text
10017 #: build/C/man7/ip.7:921
10019 "Unblock previously blocked multicast source. Returns B<EADDRNOTAVAIL> when "
10020 "given source is not being blocked."
10023 #. FIXME As at 2.6.12, 14 Jun 2005, the following are undocumented:
10025 #. ip_conntrack_max
10026 #. type: Plain text
10027 #: build/C/man7/ip.7:942
10029 "The IP protocol supports a set of I</proc> interfaces to configure some "
10030 "global parameters. The parameters can be accessed by reading or writing "
10031 "files in the directory I</proc/sys/net/ipv4/>. Interfaces described as "
10032 "I<Boolean> take an integer value, with a nonzero value (\"true\") meaning "
10033 "that the corresponding option is enabled, and a zero value (\"false\") "
10034 "meaning that the option is disabled."
10038 #: build/C/man7/ip.7:942
10040 msgid "I<ip_always_defrag> (Boolean; since Linux 2.2.13)"
10043 #. type: Plain text
10044 #: build/C/man7/ip.7:948
10046 "[New with kernel 2.2.13; in earlier kernel versions this feature was "
10047 "controlled at compile time by the B<CONFIG_IP_ALWAYS_DEFRAG> option; this "
10048 "option is not present in 2.4.x and later]"
10051 #. type: Plain text
10052 #: build/C/man7/ip.7:955
10054 "When this boolean flag is enabled (not equal 0), incoming fragments (parts "
10055 "of IP packets that arose when some host between origin and destination "
10056 "decided that the packets were too large and cut them into pieces) will be "
10057 "reassembled (defragmented) before being processed, even if they are about to "
10061 #. type: Plain text
10062 #: build/C/man7/ip.7:962
10064 "Only enable if running either a firewall that is the sole link to your "
10065 "network or a transparent proxy; never ever use it for a normal router or "
10066 "host. Otherwise, fragmented communication can be disturbed if the fragments "
10067 "travel over different links. Defragmentation also has a large memory and "
10071 #. type: Plain text
10072 #: build/C/man7/ip.7:966
10074 "This is automagically turned on when masquerading or transparent proxying "
10079 #: build/C/man7/ip.7:966
10081 msgid "I<ip_autoconfig> (since Linux 2.2 to 2.6.17)"
10084 #. Precisely: since 2.1.68
10085 #. FIXME document ip_autoconfig
10086 #. type: Plain text
10087 #: build/C/man7/ip.7:972
10088 msgid "Not documented."
10092 #: build/C/man7/ip.7:972
10094 msgid "I<ip_default_ttl> (integer; default: 64; since Linux 2.2)"
10097 #. Precisely: 2.1.15
10098 #. type: Plain text
10099 #: build/C/man7/ip.7:980
10101 "Set the default time-to-live value of outgoing packets. This can be changed "
10102 "per socket with the B<IP_TTL> option."
10106 #: build/C/man7/ip.7:980
10108 msgid "I<ip_dynaddr> (Boolean; default: disabled; since Linux 2.0.31)"
10111 #. type: Plain text
10112 #: build/C/man7/ip.7:987
10114 "Enable dynamic socket address and masquerading entry rewriting on interface "
10115 "address change. This is useful for dialup interface with changing IP "
10116 "addresses. 0 means no rewriting, 1 turns it on and 2 enables verbose mode."
10120 #: build/C/man7/ip.7:987
10122 msgid "I<ip_forward> (Boolean; default: disabled; since Linux 1.2)"
10125 #. type: Plain text
10126 #: build/C/man7/ip.7:992
10128 "Enable IP forwarding with a boolean flag. IP forwarding can be also set on "
10129 "a per-interface basis."
10133 #: build/C/man7/ip.7:992
10135 msgid "I<ip_local_port_range> (since Linux 2.2)"
10138 #. Precisely: since 2.1.68
10139 #. type: Plain text
10140 #: build/C/man7/ip.7:1000
10142 "This file contains two integers that define the default local port range "
10143 "allocated to sockets that are not explicitly bound to a port number\\(emthat "
10144 "is, the range used for I<ephemeral ports>. An ephemeral port is allocated "
10145 "to a socket in the following circumstances:"
10148 #. type: Plain text
10149 #: build/C/man7/ip.7:1004
10151 "the port number in a socket address is specified as 0 when calling "
10155 #. type: Plain text
10156 #: build/C/man7/ip.7:1007
10157 msgid "B<listen>(2) is called on a stream socket that was not previously bound;"
10160 #. type: Plain text
10161 #: build/C/man7/ip.7:1010
10162 msgid "B<connect>(2) was called on a socket that was not previously bound;"
10165 #. type: Plain text
10166 #: build/C/man7/ip.7:1013
10167 msgid "B<sendto>(2) is called on a datagram socket that was not previously bound."
10170 #. type: Plain text
10171 #: build/C/man7/ip.7:1020
10173 "Allocation of ephemeral ports starts with the first number in "
10174 "I<ip_local_port_range> and ends with the second number. If the range of "
10175 "ephemeral ports is exhausted, then the relevant system call returns an error "
10179 #. type: Plain text
10180 #: build/C/man7/ip.7:1031
10182 "Note that the port range in I<ip_local_port_range> should not conflict with "
10183 "the ports used by masquerading (although the case is handled). Also, "
10184 "arbitrary choices may cause problems with some firewall packet filters that "
10185 "make assumptions about the local ports in use. The first number should be "
10186 "at least greater than 1024, or better, greater than 4096, to avoid clashes "
10187 "with well known ports and to minimize firewall problems."
10191 #: build/C/man7/ip.7:1031
10193 msgid "I<ip_no_pmtu_disc> (Boolean; default: disabled; since Linux 2.2)"
10196 #. Precisely: 2.1.15
10198 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
10199 #. type: Plain text
10200 #: build/C/man7/ip.7:1043
10202 "If enabled, don't do Path MTU Discovery for TCP sockets by default. Path "
10203 "MTU discovery may fail if misconfigured firewalls (that drop all ICMP "
10204 "packets) or misconfigured interfaces (e.g., a point-to-point link where the "
10205 "both ends don't agree on the MTU) are on the path. It is better to fix the "
10206 "broken routers on the path than to turn off Path MTU Discovery globally, "
10207 "because not doing it incurs a high cost to the network."
10211 #: build/C/man7/ip.7:1043
10213 msgid "I<ip_nonlocal_bind> (Boolean; default: disabled; since Linux 2.4)"
10216 #. Precisely: patch-2.4.0-test10
10218 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
10219 #. type: Plain text
10220 #: build/C/man7/ip.7:1052
10222 "If set, allows processes to B<bind>(2) to nonlocal IP addresses, which can "
10223 "be quite useful, but may break some applications."
10227 #: build/C/man7/ip.7:1052
10229 msgid "I<ip6frag_time> (integer; default: 30)"
10233 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
10234 #. type: Plain text
10235 #: build/C/man7/ip.7:1057
10236 msgid "Time in seconds to keep an IPv6 fragment in memory."
10240 #: build/C/man7/ip.7:1057
10242 msgid "I<ip6frag_secret_interval> (integer; default: 600)"
10245 #. type: Plain text
10246 #: build/C/man7/ip.7:1061
10248 "Regeneration interval (in seconds) of the hash secret (or lifetime for the "
10249 "hash secret) for IPv6 fragments."
10253 #: build/C/man7/ip.7:1061
10255 msgid "I<ipfrag_high_thresh> (integer), I<ipfrag_low_thresh> (integer)"
10258 #. type: Plain text
10259 #: build/C/man7/ip.7:1068
10261 "If the amount of queued IP fragments reaches I<ipfrag_high_thresh>, the "
10262 "queue is pruned down to I<ipfrag_low_thresh>. Contains an integer with the "
10267 #: build/C/man7/ip.7:1068
10272 #. FIXME Document the conf/*/* interfaces
10274 #. FIXME Document the route/* interfaces
10275 #. type: Plain text
10276 #: build/C/man7/ip.7:1075
10277 msgid "See B<arp>(7)."
10281 #. commented out the following because ipchains is obsolete
10283 #. The ioctls to configure firewalling are documented in
10288 #. type: Plain text
10289 #: build/C/man7/ip.7:1088
10290 msgid "All ioctls described in B<socket>(7) apply to B<ip>."
10293 #. FIXME Add a discussion of multicasting
10294 #. type: Plain text
10295 #: build/C/man7/ip.7:1092
10297 "Ioctls to configure generic device parameters are described in "
10301 #. type: Plain text
10302 #: build/C/man7/ip.7:1112
10304 "The user tried to execute an operation without the necessary permissions. "
10305 "These include: sending a packet to a broadcast address without having the "
10306 "B<SO_BROADCAST> flag set; sending a packet via a I<prohibit> route; "
10307 "modifying firewall settings without superuser privileges (the "
10308 "B<CAP_NET_ADMIN> capability); binding to a privileged port without superuser "
10309 "privileges (the B<CAP_NET_BIND_SERVICE> capability)."
10312 #. type: Plain text
10313 #: build/C/man7/ip.7:1125
10314 msgid "An connection operation on a nonblocking socket is already in progress."
10317 #. type: Plain text
10318 #: build/C/man7/ip.7:1134
10320 "No valid routing table entry matches the destination address. This error "
10321 "can be caused by a ICMP message from a remote router or for the local "
10325 #. type: Plain text
10326 #: build/C/man7/ip.7:1140
10328 "Invalid argument passed. For send operations this can be caused by sending "
10329 "to a I<blackhole> route."
10332 #. type: Plain text
10333 #: build/C/man7/ip.7:1147
10334 msgid "Datagram is bigger than an MTU on the path and it cannot be fragmented."
10338 #: build/C/man7/ip.7:1147
10340 msgid "B<ENOBUFS>, B<ENOMEM>"
10343 #. type: Plain text
10344 #: build/C/man7/ip.7:1152
10346 "Not enough free memory. This often means that the memory allocation is "
10347 "limited by the socket buffer limits, not by the system memory, but this is "
10348 "not 100% consistent."
10351 #. type: Plain text
10352 #: build/C/man7/ip.7:1170
10354 "User doesn't have permission to set high priority, change configuration, or "
10355 "send signals to the requested process or group."
10358 #. type: Plain text
10359 #: build/C/man7/ip.7:1176
10360 msgid "The socket is not configured or an unknown socket type was requested."
10363 #. type: Plain text
10364 #: build/C/man7/ip.7:1183
10366 "Other errors may be generated by the overlaying protocols; see B<tcp>(7), "
10367 "B<raw>(7), B<udp>(7), and B<socket>(7)."
10370 #. IP_PASSSEC is Linux-specific
10371 #. IP_XFRM_POLICY is Linux-specific
10372 #. IP_IPSEC_POLICY is a nonstandard extension, also present on some BSDs
10373 #. type: Plain text
10374 #: build/C/man7/ip.7:1198
10376 "B<IP_FREEBIND>, B<IP_MSFILTER>, B<IP_MTU>, B<IP_MTU_DISCOVER>, "
10377 "B<IP_RECVORIGDSTADDR>, B<IP_PKTINFO>, B<IP_RECVERR>, B<IP_ROUTER_ALERT>, and "
10378 "B<IP_TRANSPARENT> are Linux-specific."
10381 #. type: Plain text
10382 #: build/C/man7/ip.7:1207
10384 "Be very careful with the B<SO_BROADCAST> option - it is not privileged in "
10385 "Linux. It is easy to overload the network with careless broadcasts. For "
10386 "new application protocols it is better to use a multicast group instead of "
10387 "broadcasting. Broadcasting is discouraged."
10390 #. type: Plain text
10391 #: build/C/man7/ip.7:1217
10393 "Some other BSD sockets implementations provide B<IP_RCVDSTADDR> and "
10394 "B<IP_RECVIF> socket options to get the destination address and the interface "
10395 "of received datagrams. Linux has the more general B<IP_PKTINFO> for the "
10399 #. type: Plain text
10400 #: build/C/man7/ip.7:1226
10402 "Some BSD sockets implementations also provide an B<IP_RECVTTL> option, but "
10403 "an ancillary message with type B<IP_RECVTTL> is passed with the incoming "
10404 "packet. This is different from the B<IP_TTL> option used in Linux."
10407 #. type: Plain text
10408 #: build/C/man7/ip.7:1232
10410 "Using B<SOL_IP> socket options level isn't portable, BSD-based stacks use "
10411 "B<IPPROTO_IP> level."
10414 #. type: Plain text
10415 #: build/C/man7/ip.7:1245
10417 "For compatibility with Linux 2.0, the obsolete B<socket(AF_INET, "
10418 "SOCK_PACKET, >I<protocol>B<)> syntax is still supported to open a "
10419 "B<packet>(7) socket. This is deprecated and should be replaced by "
10420 "B<socket(AF_PACKET, SOCK_RAW, >I<protocol>B<)> instead. The main difference "
10421 "is the new I<sockaddr_ll> address structure for generic link layer "
10422 "information instead of the old B<sockaddr_pkt>."
10425 #. type: Plain text
10426 #: build/C/man7/ip.7:1255
10428 "The error used to diagnose exhaustion of the ephemeral port range differs "
10429 "across the various system calls (B<connect>(2), B<bind>(2), B<listen>(2), "
10430 "B<sendto>(2)) that can assign ephemeral ports."
10434 #. Some versions of glibc forget to declare
10435 #. .IR in_pktinfo .
10436 #. Workaround currently is to copy it into your program from this man page.
10437 #. type: Plain text
10438 #: build/C/man7/ip.7:1262
10440 "The ioctls to configure IP-specific interface options and ARP tables are not "
10445 #. This man page was written by Andi Kleen.
10446 #. type: Plain text
10447 #: build/C/man7/ip.7:1272
10449 "Receiving the original destination address with B<MSG_ERRQUEUE> in "
10450 "I<msg_name> by B<recvmsg>(2) does not work in some 2.2 kernels."
10453 #. type: Plain text
10454 #: build/C/man7/ip.7:1285
10456 "B<recvmsg>(2), B<sendmsg>(2), B<byteorder>(3), B<ipfw>(4), "
10457 "B<capabilities>(7), B<icmp>(7), B<ipv6>(7), B<netlink>(7), B<raw>(7), "
10458 "B<socket>(7), B<tcp>(7), B<udp>(7)"
10461 #. type: Plain text
10462 #: build/C/man7/ip.7:1288
10464 "RFC\\ 791 for the original IP specification. RFC\\ 1122 for the IPv4 host "
10465 "requirements. RFC\\ 1812 for the IPv4 router requirements."
10469 #: build/C/man7/ipv6.7:86
10475 #: build/C/man7/ipv6.7:86 build/C/man7/packet.7:12
10480 #. type: Plain text
10481 #: build/C/man7/ipv6.7:89
10482 msgid "ipv6 - Linux IPv6 protocol implementation"
10485 #. type: Plain text
10486 #: build/C/man7/ipv6.7:95
10487 msgid "I<tcp6_socket>B< = socket(AF_INET6, SOCK_STREAM, 0);>"
10490 #. type: Plain text
10491 #: build/C/man7/ipv6.7:97
10492 msgid "I<raw6_socket>B< = socket(AF_INET6, SOCK_RAW, >I<protocol>B<);>"
10495 #. type: Plain text
10496 #: build/C/man7/ipv6.7:99
10497 msgid "I<udp6_socket>B< = socket(AF_INET6, SOCK_DGRAM, >I<protocol>B<);>"
10500 #. type: Plain text
10501 #: build/C/man7/ipv6.7:106
10503 "Linux 2.2 optionally implements the Internet Protocol, version 6. This man "
10504 "page contains a description of the IPv6 basic API as implemented by the "
10505 "Linux kernel and glibc 2.1. The interface is based on the BSD sockets "
10506 "interface; see B<socket>(7)."
10509 #. type: Plain text
10510 #: build/C/man7/ipv6.7:111
10512 "The IPv6 API aims to be mostly compatible with the IPv4 API (see B<ip>(7)). "
10513 "Only differences are described in this man page."
10516 #. type: Plain text
10517 #: build/C/man7/ipv6.7:123
10519 "To bind an B<AF_INET6> socket to any process, the local address should be "
10520 "copied from the I<in6addr_any> variable which has I<in6_addr> type. In "
10521 "static initializations, B<IN6ADDR_ANY_INIT> may also be used, which expands "
10522 "to a constant expression. Both of them are in network byte order."
10525 #. type: Plain text
10526 #: build/C/man7/ipv6.7:130
10528 "The IPv6 loopback address (::1) is available in the global "
10529 "I<in6addr_loopback> variable. For initializations, B<IN6ADDR_LOOPBACK_INIT> "
10533 #. type: Plain text
10534 #: build/C/man7/ipv6.7:137
10536 "IPv4 connections can be handled with the v6 API by using the v4-mapped-on-v6 "
10537 "address type; thus a program only needs to support this API type to support "
10538 "both protocols. This is handled transparently by the address handling "
10539 "functions in the C library."
10542 #. type: Plain text
10543 #: build/C/man7/ipv6.7:142
10545 "IPv4 and IPv6 share the local port space. When you get an IPv4 connection "
10546 "or packet to a IPv6 socket, its source address will be mapped to v6 and it "
10547 "will be mapped to v6."
10550 #. type: Plain text
10551 #: build/C/man7/ipv6.7:152
10554 "struct sockaddr_in6 {\n"
10555 " sa_family_t sin6_family; /* AF_INET6 */\n"
10556 " in_port_t sin6_port; /* port number */\n"
10557 " uint32_t sin6_flowinfo; /* IPv6 flow information */\n"
10558 " struct in6_addr sin6_addr; /* IPv6 address */\n"
10559 " uint32_t sin6_scope_id; /* Scope ID (new in 2.4) */\n"
10563 #. type: Plain text
10564 #: build/C/man7/ipv6.7:156
10567 "struct in6_addr {\n"
10568 " unsigned char s6_addr[16]; /* IPv6 address */\n"
10572 #. type: Plain text
10573 #: build/C/man7/ipv6.7:178
10575 "I<sin6_family> is always set to B<AF_INET6>; I<sin6_port> is the protocol "
10576 "port (see I<sin_port> in B<ip>(7)); I<sin6_flowinfo> is the IPv6 flow "
10577 "identifier; I<sin6_addr> is the 128-bit IPv6 address. I<sin6_scope_id> is "
10578 "an ID depending on the scope of the address. It is new in Linux 2.4. Linux "
10579 "supports it only for link-local addresses, in that case I<sin6_scope_id> "
10580 "contains the interface index (see B<netdevice>(7))"
10583 #. type: Plain text
10584 #: build/C/man7/ipv6.7:184
10586 "IPv6 supports several address types: unicast to address a single host, "
10587 "multicast to address a group of hosts, anycast to address the nearest member "
10588 "of a group of hosts (not implemented in Linux), IPv4-on-IPv6 to address a "
10589 "IPv4 host, and other reserved address types."
10592 #. type: Plain text
10593 #: build/C/man7/ipv6.7:190
10595 "The address notation for IPv6 is a group of 8 4-digit hexadecimal numbers, "
10596 "separated with a \\(aq:\\(aq. \\&\"::\" stands for a string of 0 bits. "
10597 "Special addresses are ::1 for loopback and ::FFFF:E<lt>IPv4 addressE<gt> for "
10598 "IPv4-mapped-on-IPv6."
10601 #. type: Plain text
10602 #: build/C/man7/ipv6.7:192
10603 msgid "The port space of IPv6 is shared with IPv4."
10606 #. type: Plain text
10607 #: build/C/man7/ipv6.7:200
10609 "IPv6 supports some protocol-specific socket options that can be set with "
10610 "B<setsockopt>(2) and read with B<getsockopt>(2). The socket option level "
10611 "for IPv6 is B<IPPROTO_IPV6>. A boolean integer flag is zero when it is "
10612 "false, otherwise true."
10616 #: build/C/man7/ipv6.7:200
10618 msgid "B<IPV6_ADDRFORM>"
10621 #. type: Plain text
10622 #: build/C/man7/ipv6.7:214
10624 "Turn an B<AF_INET6> socket into a socket of a different address family. "
10625 "Only B<AF_INET> is currently supported for that. It is allowed only for "
10626 "IPv6 sockets that are connected and bound to a v4-mapped-on-v6 address. The "
10627 "argument is a pointer to an integer containing B<AF_INET>. This is useful "
10628 "to pass v4-mapped sockets as file descriptors to programs that don't know "
10629 "how to deal with the IPv6 API."
10633 #: build/C/man7/ipv6.7:214
10635 msgid "B<IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP>"
10638 #. type: Plain text
10639 #: build/C/man7/ipv6.7:219
10641 "Control membership in multicast groups. Argument is a pointer to a I<struct "
10646 #: build/C/man7/ipv6.7:219
10648 msgid "B<IPV6_MTU>"
10651 #. type: Plain text
10652 #: build/C/man7/ipv6.7:225
10654 "B<getsockopt>(): Retrieve the current known path MTU of the current socket. "
10655 "Only valid when the socket has been connected. Returns an integer."
10658 #. type: Plain text
10659 #: build/C/man7/ipv6.7:231
10661 "B<setsockopt>(): Set the MTU to be used for the socket. The MTU is limited "
10662 "by the device MTU or the path MTU when path MTU discovery is enabled. "
10663 "Argument is a pointer to integer."
10667 #: build/C/man7/ipv6.7:231
10669 msgid "B<IPV6_MTU_DISCOVER>"
10672 #. type: Plain text
10673 #: build/C/man7/ipv6.7:239
10675 "Control path-MTU discovery on the socket. See B<IP_MTU_DISCOVER> in "
10676 "B<ip>(7) for details."
10680 #: build/C/man7/ipv6.7:239
10682 msgid "B<IPV6_MULTICAST_HOPS>"
10685 #. type: Plain text
10686 #: build/C/man7/ipv6.7:246
10688 "Set the multicast hop limit for the socket. Argument is a pointer to an "
10689 "integer. -1 in the value means use the route default, otherwise it should "
10690 "be between 0 and 255."
10694 #: build/C/man7/ipv6.7:246
10696 msgid "B<IPV6_MULTICAST_IF>"
10699 #. type: Plain text
10700 #: build/C/man7/ipv6.7:257
10702 "Set the device for outgoing multicast packets on the socket. This is "
10703 "allowed only for B<SOCK_DGRAM> and B<SOCK_RAW> socket. The argument is a "
10704 "pointer to an interface index (see B<netdevice>(7)) in an integer."
10708 #: build/C/man7/ipv6.7:257
10710 msgid "B<IPV6_MULTICAST_LOOP>"
10713 #. type: Plain text
10714 #: build/C/man7/ipv6.7:261
10716 "Control whether the socket sees multicast packets that it has send itself. "
10717 "Argument is a pointer to boolean."
10721 #: build/C/man7/ipv6.7:261
10723 msgid "B<IPV6_RECVPKTINFO> (since Linux 2.6.14)"
10726 #. type: Plain text
10727 #: build/C/man7/ipv6.7:275
10729 "Set delivery of the B<IPV6_PKTINFO> control message on incoming datagrams. "
10730 "Such control messages contain a I<struct in6_pktinfo>, as per RFC 3542. "
10731 "Only allowed for B<SOCK_DGRAM> or B<SOCK_RAW> sockets. Argument is a "
10732 "pointer to a boolean value in an integer."
10735 #. type: Plain text
10736 #: build/C/man7/ipv6.7:278
10739 "B<IPV6_RTHDR, IPV6_AUTHHDR, IPV6_DSTOPTS, IPV6_HOPOPTS, IPV6_FLOWINFO, "
10743 #. type: Plain text
10744 #: build/C/man7/ipv6.7:303
10746 "Set delivery of control messages for incoming datagrams containing extension "
10747 "headers from the received packet. B<IPV6_RTHDR> delivers the routing "
10748 "header, B<IPV6_AUTHHDR> delivers the authentication header, B<IPV6_DSTOPTS> "
10749 "delivers the destination options, B<IPV6_HOPOPTS> delivers the hop options, "
10750 "B<IPV6_FLOWINFO> delivers an integer containing the flow ID, "
10751 "B<IPV6_HOPLIMIT> delivers an integer containing the hop count of the "
10752 "packet. The control messages have the same type as the socket option. All "
10753 "these header options can also be set for outgoing packets by putting the "
10754 "appropriate control message into the control buffer of B<sendmsg>(2). Only "
10755 "allowed for B<SOCK_DGRAM> or B<SOCK_RAW> sockets. Argument is a pointer to "
10760 #: build/C/man7/ipv6.7:303
10762 msgid "B<IPV6_RECVERR>"
10765 #. type: Plain text
10766 #: build/C/man7/ipv6.7:312
10768 "Control receiving of asynchronous error options. See B<IP_RECVERR> in "
10769 "B<ip>(7) for details. Argument is a pointer to boolean."
10773 #: build/C/man7/ipv6.7:312
10775 msgid "B<IPV6_ROUTER_ALERT>"
10778 #. type: Plain text
10779 #: build/C/man7/ipv6.7:327
10781 "Pass forwarded packets containing a router alert hop-by-hop option to this "
10782 "socket. Only allowed for B<SOCK_RAW> sockets. The tapped packets are not "
10783 "forwarded by the kernel, it is the user's responsibility to send them out "
10784 "again. Argument is a pointer to an integer. A positive integer indicates a "
10785 "router alert option value to intercept. Packets carrying a router alert "
10786 "option with a value field containing this integer will be delivered to the "
10787 "socket. A negative integer disables delivery of packets with router alert "
10788 "options to this socket."
10792 #: build/C/man7/ipv6.7:327
10794 msgid "B<IPV6_UNICAST_HOPS>"
10797 #. type: Plain text
10798 #: build/C/man7/ipv6.7:333
10800 "Set the unicast hop limit for the socket. Argument is a pointer to an "
10801 "integer. -1 in the value means use the route default, otherwise it should "
10802 "be between 0 and 255."
10806 #: build/C/man7/ipv6.7:333
10808 msgid "B<IPV6_V6ONLY> (since Linux 2.4.21 and 2.6)"
10812 #. type: Plain text
10813 #: build/C/man7/ipv6.7:340
10815 "If this flag is set to true (nonzero), then the socket is restricted to "
10816 "sending and receiving IPv6 packets only. In this case, an IPv4 and an IPv6 "
10817 "application can bind to a single port at the same time."
10820 #. type: Plain text
10821 #: build/C/man7/ipv6.7:344
10823 "If this flag is set to false (zero), then the socket can be used to send and "
10824 "receive packets to and from an IPv6 address or an IPv4-mapped IPv6 address."
10827 #. type: Plain text
10828 #: build/C/man7/ipv6.7:346
10829 msgid "The argument is a pointer to a boolean value in an integer."
10832 #. FLOWLABEL_MGR, FLOWINFO_SEND
10833 #. type: Plain text
10834 #: build/C/man7/ipv6.7:351
10836 "The default value for this flag is defined by the contents of the file "
10837 "I</proc/sys/net/ipv6/bindv6only>. The default value for that file is 0 "
10841 #. type: Plain text
10842 #: build/C/man7/ipv6.7:362
10844 "The user tried to B<bind>(2) to a link-local IPv6 address, but the "
10845 "I<sin6_scope_id> in the supplied I<sockaddr_in6> structure is not a valid "
10849 #. type: Plain text
10850 #: build/C/man7/ipv6.7:378
10852 "Linux 2.4 will break binary compatibility for the I<sockaddr_in6> for 64-bit "
10853 "hosts by changing the alignment of I<in6_addr> and adding an additional "
10854 "I<sin6_scope_id> field. The kernel interfaces stay compatible, but a "
10855 "program including I<sockaddr_in6> or I<in6_addr> into other structures may "
10856 "not be. This is not a problem for 32-bit hosts like i386."
10859 #. type: Plain text
10860 #: build/C/man7/ipv6.7:386
10862 "The I<sin6_flowinfo> field is new in Linux 2.4. It is transparently "
10863 "passed/read by the kernel when the passed address length contains it. Some "
10864 "programs that pass a longer address buffer and then check the outgoing "
10865 "address length may break."
10868 #. type: Plain text
10869 #: build/C/man7/ipv6.7:396
10871 "The I<sockaddr_in6> structure is bigger than the generic I<sockaddr>. "
10872 "Programs that assume that all address types can be stored safely in a "
10873 "I<struct sockaddr> need to be changed to use I<struct sockaddr_storage> for "
10877 #. type: Plain text
10878 #: build/C/man7/ipv6.7:401
10880 "The IPv6 extended API as in RFC\\ 2292 is currently only partly implemented; "
10881 "although the 2.2 kernel has near complete support for receiving options, the "
10882 "macros for generating IPv6 options are missing in glibc 2.1."
10885 #. type: Plain text
10886 #: build/C/man7/ipv6.7:403
10887 msgid "IPSec support for EH and AH headers is missing."
10890 #. type: Plain text
10891 #: build/C/man7/ipv6.7:405
10892 msgid "Flow label management is not complete and not documented here."
10895 #. type: Plain text
10896 #: build/C/man7/ipv6.7:407
10897 msgid "This man page is not complete."
10900 #. type: Plain text
10901 #: build/C/man7/ipv6.7:410
10902 msgid "B<cmsg>(3), B<ip>(7)"
10905 #. type: Plain text
10906 #: build/C/man7/ipv6.7:413
10908 "RFC\\ 2553: IPv6 BASIC API; Linux tries to be compliant to this. RFC\\ "
10909 "2460: IPv6 specification."
10913 #: build/C/man7/netdevice.7:18
10919 #: build/C/man7/netdevice.7:18
10924 #. type: Plain text
10925 #: build/C/man7/netdevice.7:21
10926 msgid "netdevice - low-level access to Linux network devices"
10929 #. type: Plain text
10930 #: build/C/man7/netdevice.7:23
10931 msgid "B<#include E<lt>sys/ioctl.hE<gt>>"
10934 #. type: Plain text
10935 #: build/C/man7/netdevice.7:25
10936 msgid "B<#include E<lt>net/if.hE<gt>>"
10939 #. type: Plain text
10940 #: build/C/man7/netdevice.7:28
10942 "This man page describes the sockets interface which is used to configure "
10946 #. type: Plain text
10947 #: build/C/man7/netdevice.7:35
10949 "Linux supports some standard ioctls to configure network devices. They can "
10950 "be used on any socket's file descriptor regardless of the family or type. "
10951 "Most of them pass an I<ifreq> structure:"
10954 #. type: Plain text
10955 #: build/C/man7/netdevice.7:56
10959 " char ifr_name[IFNAMSIZ]; /* Interface name */\n"
10961 " struct sockaddr ifr_addr;\n"
10962 " struct sockaddr ifr_dstaddr;\n"
10963 " struct sockaddr ifr_broadaddr;\n"
10964 " struct sockaddr ifr_netmask;\n"
10965 " struct sockaddr ifr_hwaddr;\n"
10966 " short ifr_flags;\n"
10967 " int ifr_ifindex;\n"
10968 " int ifr_metric;\n"
10970 " struct ifmap ifr_map;\n"
10971 " char ifr_slave[IFNAMSIZ];\n"
10972 " char ifr_newname[IFNAMSIZ];\n"
10973 " char *ifr_data;\n"
10978 #. type: Plain text
10979 #: build/C/man7/netdevice.7:64
10981 "Normally, the user specifies which device to affect by setting I<ifr_name> "
10982 "to the name of the interface. All other members of the structure may share "
10986 #. type: Plain text
10987 #: build/C/man7/netdevice.7:72
10989 "If an ioctl is marked as privileged, then using it requires an effective "
10990 "user ID of 0 or the B<CAP_NET_ADMIN> capability. If this is not the case, "
10991 "B<EPERM> will be returned."
10995 #: build/C/man7/netdevice.7:72
10997 msgid "B<SIOCGIFNAME>"
11000 #. type: Plain text
11001 #: build/C/man7/netdevice.7:80
11003 "Given the I<ifr_ifindex>, return the name of the interface in I<ifr_name>. "
11004 "This is the only ioctl which returns its result in I<ifr_name>."
11008 #: build/C/man7/netdevice.7:80
11010 msgid "B<SIOCGIFINDEX>"
11013 #. type: Plain text
11014 #: build/C/man7/netdevice.7:84
11015 msgid "Retrieve the interface index of the interface into I<ifr_ifindex>."
11019 #: build/C/man7/netdevice.7:84
11021 msgid "B<SIOCGIFFLAGS>, B<SIOCSIFFLAGS>"
11024 #. Do not right adjust text blocks in tables
11025 #. type: Plain text
11026 #: build/C/man7/netdevice.7:90
11028 "Get or set the active flag word of the device. I<ifr_flags> contains a bit "
11029 "mask of the following values:"
11033 #: build/C/man7/netdevice.7:95
11035 msgid "Device flags\n"
11039 #: build/C/man7/netdevice.7:96
11041 msgid "IFF_UP:Interface is running.\n"
11045 #: build/C/man7/netdevice.7:97
11047 msgid "IFF_BROADCAST:Valid broadcast address set.\n"
11051 #: build/C/man7/netdevice.7:98
11053 msgid "IFF_DEBUG:Internal debugging flag.\n"
11057 #: build/C/man7/netdevice.7:99
11059 msgid "IFF_LOOPBACK:Interface is a loopback interface.\n"
11063 #: build/C/man7/netdevice.7:100
11065 msgid "IFF_POINTOPOINT:Interface is a point-to-point link.\n"
11069 #: build/C/man7/netdevice.7:101
11071 msgid "IFF_RUNNING:Resources allocated.\n"
11075 #: build/C/man7/netdevice.7:102
11077 msgid "IFF_NOARP:T{\n"
11081 #: build/C/man7/netdevice.7:103
11083 msgid "No arp protocol, L2 destination address not set.\n"
11087 #: build/C/man7/netdevice.7:104 build/C/man7/netdevice.7:115
11093 #: build/C/man7/netdevice.7:105
11095 msgid "IFF_PROMISC:Interface is in promiscuous mode.\n"
11099 #: build/C/man7/netdevice.7:106
11101 msgid "IFF_NOTRAILERS:Avoid use of trailers.\n"
11105 #: build/C/man7/netdevice.7:107
11107 msgid "IFF_ALLMULTI:Receive all multicast packets.\n"
11111 #: build/C/man7/netdevice.7:108
11113 msgid "IFF_MASTER:Master of a load balancing bundle.\n"
11117 #: build/C/man7/netdevice.7:109
11119 msgid "IFF_SLAVE:Slave of a load balancing bundle.\n"
11123 #: build/C/man7/netdevice.7:110
11125 msgid "IFF_MULTICAST:Supports multicast\n"
11129 #: build/C/man7/netdevice.7:111
11131 msgid "IFF_PORTSEL:Is able to select media type via ifmap.\n"
11135 #: build/C/man7/netdevice.7:112
11137 msgid "IFF_AUTOMEDIA:Auto media selection active.\n"
11141 #: build/C/man7/netdevice.7:113
11143 msgid "IFF_DYNAMIC:T{\n"
11147 #: build/C/man7/netdevice.7:114
11149 msgid "The addresses are lost when the interface goes down.\n"
11153 #: build/C/man7/netdevice.7:116
11155 msgid "IFF_LOWER_UP:Driver signals L1 up (since Linux 2.6.17)\n"
11159 #: build/C/man7/netdevice.7:117
11161 msgid "IFF_DORMANT:Driver signals dormant (since Linux 2.6.17)\n"
11165 #: build/C/man7/netdevice.7:118
11167 msgid "IFF_ECHO:Echo sent packets (since Linux 2.6.25)\n"
11170 #. type: Plain text
11171 #: build/C/man7/netdevice.7:124
11173 "Setting the active flag word is a privileged operation, but any process may "
11178 #: build/C/man7/netdevice.7:124
11180 msgid "B<SIOCGIFPFLAGS>, B<SIOCSIFPFLAGS>"
11183 #. type: Plain text
11184 #: build/C/man7/netdevice.7:129
11186 "Get or set extended (private) flags for the device. I<ifr_flags> contains a "
11187 "bit mask of the following values:"
11191 #: build/C/man7/netdevice.7:133
11193 msgid "Private flags\n"
11197 #: build/C/man7/netdevice.7:134
11199 msgid "IFF_802_1Q_VLAN:Interface is 802.1Q VLAN device.\n"
11203 #: build/C/man7/netdevice.7:135
11205 msgid "IFF_EBRIDGE:Interface is Ethernet bridging device.\n"
11209 #: build/C/man7/netdevice.7:136
11211 msgid "IFF_SLAVE_INACTIVE:Interface is inactive bonding slave.\n"
11215 #: build/C/man7/netdevice.7:137
11217 msgid "IFF_MASTER_8023AD:Interface is 802.3ad bonding master.\n"
11221 #: build/C/man7/netdevice.7:138
11223 msgid "IFF_MASTER_ALB:Interface is balanced-alb bonding master.\n"
11227 #: build/C/man7/netdevice.7:139
11229 msgid "IFF_BONDING:Interface is a bonding master or slave.\n"
11233 #: build/C/man7/netdevice.7:140
11235 msgid "IFF_SLAVE_NEEDARP:Interface needs ARPs for validation.\n"
11239 #: build/C/man7/netdevice.7:141
11241 msgid "IFF_ISATAP:Interface is RFC4214 ISATAP interface.\n"
11244 #. type: Plain text
11245 #: build/C/man7/netdevice.7:145
11246 msgid "Setting the extended (private) interface flags is a privileged operation."
11250 #: build/C/man7/netdevice.7:145
11252 msgid "B<SIOCGIFADDR>, B<SIOCSIFADDR>"
11255 #. type: Plain text
11256 #: build/C/man7/netdevice.7:153
11258 "Get or set the address of the device using I<ifr_addr>. Setting the "
11259 "interface address is a privileged operation. For compatibility, only "
11260 "B<AF_INET> addresses are accepted or returned."
11264 #: build/C/man7/netdevice.7:153
11266 msgid "B<SIOCGIFDSTADDR>, B<SIOCSIFDSTADDR>"
11269 #. type: Plain text
11270 #: build/C/man7/netdevice.7:161
11272 "Get or set the destination address of a point-to-point device using "
11273 "I<ifr_dstaddr>. For compatibility, only B<AF_INET> addresses are accepted "
11274 "or returned. Setting the destination address is a privileged operation."
11278 #: build/C/man7/netdevice.7:161
11280 msgid "B<SIOCGIFBRDADDR>, B<SIOCSIFBRDADDR>"
11283 #. type: Plain text
11284 #: build/C/man7/netdevice.7:169
11286 "Get or set the broadcast address for a device using I<ifr_brdaddr>. For "
11287 "compatibility, only B<AF_INET> addresses are accepted or returned. Setting "
11288 "the broadcast address is a privileged operation."
11292 #: build/C/man7/netdevice.7:169
11294 msgid "B<SIOCGIFNETMASK>, B<SIOCSIFNETMASK>"
11297 #. type: Plain text
11298 #: build/C/man7/netdevice.7:177
11300 "Get or set the network mask for a device using I<ifr_netmask>. For "
11301 "compatibility, only B<AF_INET> addresses are accepted or returned. Setting "
11302 "the network mask is a privileged operation."
11306 #: build/C/man7/netdevice.7:177
11308 msgid "B<SIOCGIFMETRIC>, B<SIOCSIFMETRIC>"
11311 #. type: Plain text
11312 #: build/C/man7/netdevice.7:186
11314 "Get or set the metric of the device using I<ifr_metric>. This is currently "
11315 "not implemented; it sets I<ifr_metric> to 0 if you attempt to read it and "
11316 "returns B<EOPNOTSUPP> if you attempt to set it."
11320 #: build/C/man7/netdevice.7:186
11322 msgid "B<SIOCGIFMTU>, B<SIOCSIFMTU>"
11325 #. type: Plain text
11326 #: build/C/man7/netdevice.7:193
11328 "Get or set the MTU (Maximum Transfer Unit) of a device using I<ifr_mtu>. "
11329 "Setting the MTU is a privileged operation. Setting the MTU to too small "
11330 "values may cause kernel crashes."
11334 #: build/C/man7/netdevice.7:193
11336 msgid "B<SIOCGIFHWADDR>, B<SIOCSIFHWADDR>"
11339 #. type: Plain text
11340 #: build/C/man7/netdevice.7:204
11342 "Get or set the hardware address of a device using I<ifr_hwaddr>. The "
11343 "hardware address is specified in a struct I<sockaddr>. I<sa_family> "
11344 "contains the ARPHRD_* device type, I<sa_data> the L2 hardware address "
11345 "starting from byte 0. Setting the hardware address is a privileged "
11350 #: build/C/man7/netdevice.7:204
11352 msgid "B<SIOCSIFHWBROADCAST>"
11355 #. type: Plain text
11356 #: build/C/man7/netdevice.7:209
11358 "Set the hardware broadcast address of a device from I<ifr_hwaddr>. This is "
11359 "a privileged operation."
11363 #: build/C/man7/netdevice.7:209
11365 msgid "B<SIOCGIFMAP>, B<SIOCSIFMAP>"
11368 #. type: Plain text
11369 #: build/C/man7/netdevice.7:214
11371 "Get or set the interface's hardware parameters using I<ifr_map>. Setting "
11372 "the parameters is a privileged operation."
11375 #. type: Plain text
11376 #: build/C/man7/netdevice.7:225
11380 " unsigned long mem_start;\n"
11381 " unsigned long mem_end;\n"
11382 " unsigned short base_addr;\n"
11383 " unsigned char irq;\n"
11384 " unsigned char dma;\n"
11385 " unsigned char port;\n"
11389 #. type: Plain text
11390 #: build/C/man7/netdevice.7:230
11392 "The interpretation of the ifmap structure depends on the device driver and "
11393 "the architecture."
11397 #: build/C/man7/netdevice.7:230
11399 msgid "B<SIOCADDMULTI>, B<SIOCDELMULTI>"
11402 #. type: Plain text
11403 #: build/C/man7/netdevice.7:239
11405 "Add an address to or delete an address from the device's link layer "
11406 "multicast filters using I<ifr_hwaddr>. These are privileged operations. "
11407 "See also B<packet>(7) for an alternative."
11411 #: build/C/man7/netdevice.7:239
11413 msgid "B<SIOCGIFTXQLEN>, B<SIOCSIFTXQLEN>"
11416 #. type: Plain text
11417 #: build/C/man7/netdevice.7:244
11419 "Get or set the transmit queue length of a device using I<ifr_qlen>. Setting "
11420 "the transmit queue length is a privileged operation."
11424 #: build/C/man7/netdevice.7:244
11426 msgid "B<SIOCSIFNAME>"
11429 #. type: Plain text
11430 #: build/C/man7/netdevice.7:253
11432 "Changes the name of the interface specified in I<ifr_name> to "
11433 "I<ifr_newname>. This is a privileged operation. It is allowed only when "
11434 "the interface is not up."
11438 #: build/C/man7/netdevice.7:253
11440 msgid "B<SIOCGIFCONF>"
11443 #. type: Plain text
11444 #: build/C/man7/netdevice.7:263
11446 "Return a list of interface (transport layer) addresses. This currently "
11447 "means only addresses of the B<AF_INET> (IPv4) family for compatibility. "
11448 "Unlike the others, this ioctl passes an I<ifconf> structure:"
11451 #. type: Plain text
11452 #: build/C/man7/netdevice.7:273
11455 "struct ifconf {\n"
11456 " int ifc_len; /* size of buffer */\n"
11458 " char *ifc_buf; /* buffer address */\n"
11459 " struct ifreq *ifc_req; /* array of structures */\n"
11464 #. type: Plain text
11465 #: build/C/man7/netdevice.7:299
11467 "If I<ifc_req> is NULL, B<SIOCGIFCONF> returns the necessary buffer size in "
11468 "bytes for receiving all available addresses in I<ifc_len>. Otherwise, "
11469 "I<ifc_req> contains a pointer to an array of I<ifreq> structures to be "
11470 "filled with all currently active L3 interface addresses. I<ifc_len> "
11471 "contains the size of the array in bytes. Within each I<ifreq> structure, "
11472 "I<ifr_name> will receive the interface name, and I<ifr_addr> the address. "
11473 "The actual number of bytes transferred is returned in I<ifc_len>."
11476 #. type: Plain text
11477 #: build/C/man7/netdevice.7:315
11479 "If the size specified by I<ifc_len> is insufficient to store all the "
11480 "addresses, the kernel will skip the exceeding ones and return success. "
11481 "There is no reliable way of detecting this condition once it has occurred. "
11482 "It is therefore recommended to either determine the necessary buffer size "
11483 "beforehand by calling B<SIOCGIFCONF> with I<ifc_req> set to NULL, or to "
11484 "retry the call with a bigger buffer whenever I<ifc_len> upon return differs "
11485 "by less than I<sizeof(struct ifreq)> from its original value."
11488 #. Slaving isn't supported in 2.2
11491 #. .BR SIOCGIFSLAVE ", " SIOCSIFSLAVE
11492 #. Get or set the slave device using
11494 #. Setting the slave device is a privileged operation.
11496 #. FIXME . add amateur radio stuff.
11497 #. type: Plain text
11498 #: build/C/man7/netdevice.7:332
11500 "If an error occurs accessing the I<ifconf> or I<ifreq> structures, B<EFAULT> "
11501 "will be returned."
11504 #. type: Plain text
11505 #: build/C/man7/netdevice.7:338
11507 "Most protocols support their own ioctls to configure protocol-specific "
11508 "interface options. See the protocol man pages for a description. For "
11509 "configuring IP addresses, see B<ip>(7)."
11512 #. type: Plain text
11513 #: build/C/man7/netdevice.7:341
11515 "In addition, some devices support private ioctls. These are not described "
11519 #. type: Plain text
11520 #: build/C/man7/netdevice.7:349
11522 "Strictly speaking, B<SIOCGIFCONF> and the other ioctls that accept or return "
11523 "only B<AF_INET> socket addresses, are IP-specific and belong in B<ip>(7)."
11526 #. type: Plain text
11527 #: build/C/man7/netdevice.7:354
11529 "The names of interfaces with no addresses or that don't have the "
11530 "B<IFF_RUNNING> flag set can be found via I</proc/net/dev>."
11533 #. type: Plain text
11534 #: build/C/man7/netdevice.7:359
11536 "Local IPv6 IP addresses can be found via I</proc/net> or via "
11540 #. type: Plain text
11541 #: build/C/man7/netdevice.7:365
11543 "glibc 2.1 is missing the I<ifr_newname> macro in I<E<lt>net/if.hE<gt>>. Add "
11544 "the following to your program as a workaround:"
11547 #. type: Plain text
11548 #: build/C/man7/netdevice.7:371
11551 "#ifndef ifr_newname\n"
11552 "#define ifr_newname ifr_ifru.ifru_slave\n"
11556 #. type: Plain text
11557 #: build/C/man7/netdevice.7:377
11558 msgid "B<proc>(5), B<capabilities>(7), B<ip>(7), B<rtnetlink>(7)"
11562 #: build/C/man5/networks.5:26
11568 #: build/C/man5/networks.5:26
11574 #: build/C/man5/networks.5:26
11579 #. type: Plain text
11580 #: build/C/man5/networks.5:29
11581 msgid "networks - network name information"
11584 #. type: Plain text
11585 #: build/C/man5/networks.5:35
11587 "The file I</etc/networks> is a plain ASCII file that describes known DARPA "
11588 "networks and symbolic names for these networks. Each line represents a "
11589 "network and has the following structure:"
11592 #. type: Plain text
11593 #: build/C/man5/networks.5:38
11594 msgid "I<name number aliases ...>"
11597 #. type: Plain text
11598 #: build/C/man5/networks.5:46
11600 "where the fields are delimited by spaces or tabs. Empty lines are ignored. "
11601 "The hash character (B<#>) indicates the start of a comment: this character, "
11602 "and the remaining characters up to the end of the current line, are ignored "
11603 "by library functions that process the file."
11606 #. type: Plain text
11607 #: build/C/man5/networks.5:48 build/C/man5/protocols.5:59
11608 msgid "The field descriptions are:"
11612 #: build/C/man5/networks.5:48
11617 #. type: Plain text
11618 #: build/C/man5/networks.5:53
11620 "The symbolic name for the network. Network names can contain any printable "
11621 "characters except white-space characters or the comment character."
11625 #: build/C/man5/networks.5:53 build/C/man5/protocols.5:67
11630 #. type: Plain text
11631 #: build/C/man5/networks.5:58
11633 "The official number for this network in numbers-and-dots notation (see "
11634 "B<inet>(3)). The trailing \".0\" (for the host component of the network "
11635 "address) may be omitted."
11639 #: build/C/man5/networks.5:58 build/C/man5/protocols.5:71 build/C/man5/services.5:120
11644 #. type: Plain text
11645 #: build/C/man5/networks.5:61
11646 msgid "Optional aliases for the network."
11649 #. type: Plain text
11650 #: build/C/man5/networks.5:70
11652 "This file is read by the B<route>(8) and B<netstat>(8) utilities. Only "
11653 "Class A, B or C networks are supported, partitioned networks (i.e., "
11654 "network/26 or network/28) are not supported by this facility."
11657 #. type: Plain text
11658 #: build/C/man5/networks.5:74
11659 msgid "The networks definition file."
11662 #. type: Plain text
11663 #: build/C/man5/networks.5:79
11665 "B<getnetbyaddr>(3), B<getnetbyname>(3), B<getnetent>(3), B<netstat>(8), "
11670 #: build/C/man8/nscd.8:23
11675 #. type: Plain text
11676 #: build/C/man8/nscd.8:26
11677 msgid "nscd - name service cache daemon"
11680 #. type: Plain text
11681 #: build/C/man8/nscd.8:34
11683 "Nscd is a daemon that provides a cache for the most common name service "
11684 "requests. The default configuration file, I</etc/nscd.conf>, determines the "
11685 "behavior of the cache daemon. See B<nscd.conf>(5)."
11688 #. type: Plain text
11689 #: build/C/man8/nscd.8:47
11691 "Nscd provides caching for accesses of the B<passwd>(5), B<group>(5), and "
11692 "B<hosts>(5) databases through standard libc interfaces, such as "
11693 "B<getpwnam>(3), B<getpwuid>(3), B<getgrnam>(3), B<getgrgid>(3), "
11694 "B<gethostbyname>(3), and others."
11697 #. type: Plain text
11698 #: build/C/man8/nscd.8:56
11700 "There are two caches for each database: a positive one for items found, and "
11701 "a negative one for items not found. Each cache has a separate TTL "
11702 "(time-to-live) period for its data. Note that the shadow file is "
11703 "specifically not cached. B<getspnam>(3) calls remain uncached as a result."
11707 #: build/C/man8/nscd.8:56
11713 #: build/C/man8/nscd.8:57
11718 #. type: Plain text
11719 #: build/C/man8/nscd.8:60
11720 msgid "will give you a list with all options and what they do."
11723 #. type: Plain text
11724 #: build/C/man8/nscd.8:83
11726 "The daemon will try to watch for changes in configuration files appropriate "
11727 "for each database (e.g., I</etc/passwd> for the I<passwd> database or "
11728 "I</etc/hosts> and I</etc/resolv.conf> for the I<hosts> database), and flush "
11729 "the cache when these are changed. However, this will happen only after a "
11730 "short delay (unless the B<inotify>(7) mechanism is available and glibc 2.9 "
11731 "or later is available), and this auto-detection does not cover configuration "
11732 "files required by nonstandard NSS modules, if any are specified in "
11733 "I</etc/nsswitch.conf>. In that case, you need to run the following command "
11734 "after changing the configuration file of the database so that B<nscd> "
11735 "invalidates its cache:"
11738 #. type: Plain text
11739 #: build/C/man8/nscd.8:85
11741 msgid " $ B<nscd -i> I<E<lt>databaseE<gt>>\n"
11744 #. type: Plain text
11745 #: build/C/man8/nscd.8:87
11746 msgid "B<nscd.conf>(5), B<nsswitch.conf>(5)"
11750 #: build/C/man5/nscd.conf.5:20
11756 #: build/C/man5/nscd.conf.5:20
11761 #. type: Plain text
11762 #: build/C/man5/nscd.conf.5:23
11763 msgid "/etc/nscd.conf - name service cache daemon configuration file"
11766 #. type: Plain text
11767 #: build/C/man5/nscd.conf.5:36
11769 "The file I</etc/nscd.conf> is read from B<nscd>(8) at startup. Each line "
11770 "specifies either an attribute and a value, or an attribute, service, and a "
11771 "value. Fields are separated either by SPACE or TAB characters. A "
11772 "\\(aq#\\(aq (number sign) indicates the beginning of a comment; following "
11773 "characters, up to the end of the line, are not interpreted by nscd."
11776 #. type: Plain text
11777 #: build/C/man5/nscd.conf.5:39
11779 "Valid services are I<passwd>, I<group>, I<hosts>, I<services>, or "
11783 #. type: Plain text
11784 #: build/C/man5/nscd.conf.5:42
11785 msgid "B<logfile> I<debug-file-name>"
11788 #. type: Plain text
11789 #: build/C/man5/nscd.conf.5:44
11790 msgid "Specifies name of the file to which debug info should be written."
11793 #. type: Plain text
11794 #: build/C/man5/nscd.conf.5:48
11795 msgid "B<debug-level> I<value>"
11798 #. type: Plain text
11799 #: build/C/man5/nscd.conf.5:51
11800 msgid "Sets the desired debug level. The default is 0."
11803 #. type: Plain text
11804 #: build/C/man5/nscd.conf.5:55
11805 msgid "B<threads> I<number>"
11808 #. type: Plain text
11809 #: build/C/man5/nscd.conf.5:59
11811 "This is the number of threads that are started to wait for requests. At "
11812 "least five threads will always be created."
11815 #. type: Plain text
11816 #: build/C/man5/nscd.conf.5:63
11817 msgid "B<max-threads> I<number>"
11820 #. type: Plain text
11821 #: build/C/man5/nscd.conf.5:66
11822 msgid "Specifies the maximum number of threads. The default is 32."
11825 #. type: Plain text
11826 #: build/C/man5/nscd.conf.5:70
11827 msgid "B<server-user> I<user>"
11830 #. type: Plain text
11831 #: build/C/man5/nscd.conf.5:74
11833 "If this option is set, nscd will run as this user and not as root. If a "
11834 "separate cache for every user is used (-S parameter), this option is "
11838 #. type: Plain text
11839 #: build/C/man5/nscd.conf.5:78
11840 msgid "B<stat-user> I<user>"
11843 #. type: Plain text
11844 #: build/C/man5/nscd.conf.5:80
11845 msgid "Specifies the user who is allowed to request statistics."
11848 #. type: Plain text
11849 #: build/C/man5/nscd.conf.5:85
11850 msgid "B<reload-count> unlimited | I<number>"
11853 #. type: Plain text
11854 #: build/C/man5/nscd.conf.5:89
11856 "Limit on the number of times a cached entry gets reloaded without being used "
11857 "before it gets removed. The default is 5."
11860 #. type: Plain text
11861 #: build/C/man5/nscd.conf.5:93
11862 msgid "B<paranoia> I<E<lt>yes|noE<gt>>"
11865 #. type: Plain text
11866 #: build/C/man5/nscd.conf.5:96
11868 "Enabling paranoia mode causes nscd to restart itself periodically. The "
11872 #. type: Plain text
11873 #: build/C/man5/nscd.conf.5:100
11874 msgid "B<restart-interval> I<time>"
11877 #. type: Plain text
11878 #: build/C/man5/nscd.conf.5:108
11880 "Sets the restart interval to I<time> seconds if periodic restart is enabled "
11881 "by enabling B<paranoia> mode. The default is 3600."
11884 #. type: Plain text
11885 #: build/C/man5/nscd.conf.5:113
11886 msgid "B<enable-cache> I<service> I<E<lt>yes|noE<gt>>"
11889 #. type: Plain text
11890 #: build/C/man5/nscd.conf.5:118
11891 msgid "Enables or disables the specified I<service> cache. The default is no."
11894 #. type: Plain text
11895 #: build/C/man5/nscd.conf.5:123
11896 msgid "B<positive-time-to-live> I<service> I<value>"
11899 #. type: Plain text
11900 #: build/C/man5/nscd.conf.5:131
11902 "Sets the TTL (time-to-live) for positive entries (successful queries) in "
11903 "the specified cache for I<service>. I<Value> is in seconds. Larger values "
11904 "increase cache hit rates and reduce mean response times, but increase "
11905 "problems with cache coherence."
11908 #. type: Plain text
11909 #: build/C/man5/nscd.conf.5:136
11910 msgid "B<negative-time-to-live> I<service> I<value>"
11913 #. type: Plain text
11914 #: build/C/man5/nscd.conf.5:146
11916 "Sets the TTL (time-to-live) for negative entries (unsuccessful queries) in "
11917 "the specified cache for I<service>. I<Value> is in seconds. Can result in "
11918 "significant performance improvements if there are several files owned by "
11919 "UIDs (user IDs) not in system databases (for example untarring the Linux "
11920 "kernel sources as root); should be kept small to reduce cache coherency "
11924 #. type: Plain text
11925 #: build/C/man5/nscd.conf.5:151
11926 msgid "B<suggested-size> I<service> I<value>"
11929 #. type: Plain text
11930 #: build/C/man5/nscd.conf.5:156
11932 "This is the internal hash table size, I<value> should remain a prime number "
11933 "for optimum efficiency. The default is 211."
11936 #. type: Plain text
11937 #: build/C/man5/nscd.conf.5:161
11938 msgid "B<check-files> I<service> I<E<lt>yes|noE<gt>>"
11941 #. type: Plain text
11942 #: build/C/man5/nscd.conf.5:173
11944 "Enables or disables checking the file belonging to the specified I<service> "
11945 "for changes. The files are I</etc/passwd>, I</etc/group>, I</etc/hosts>, "
11946 "I</etc/services> and I</etc/netgroup>. The default is yes."
11949 #. type: Plain text
11950 #: build/C/man5/nscd.conf.5:178
11951 msgid "B<persistent> I<service> I<E<lt>yes|noE<gt>>"
11954 #. type: Plain text
11955 #: build/C/man5/nscd.conf.5:185
11957 "Keep the content of the cache for I<service> over server restarts; useful "
11958 "when B<paranoia> mode is set. The default is no."
11961 #. type: Plain text
11962 #: build/C/man5/nscd.conf.5:190
11963 msgid "B<shared> I<service> I<E<lt>yes|noE<gt>>"
11966 #. type: Plain text
11967 #: build/C/man5/nscd.conf.5:197
11969 "The memory mapping of the nscd databases for I<service> is shared with the "
11970 "clients so that they can directly search in them instead of having to ask "
11971 "the daemon over the socket each time a lookup is performed. The default is "
11975 #. type: Plain text
11976 #: build/C/man5/nscd.conf.5:202
11977 msgid "B<max-db-size> I<service> I<bytes>"
11980 #. type: Plain text
11981 #: build/C/man5/nscd.conf.5:206
11983 "The maximum allowable size, in bytes, of the database files for the "
11984 "I<service>. The default is 33554432."
11987 #. type: Plain text
11988 #: build/C/man5/nscd.conf.5:211
11989 msgid "B<auto-propagate> I<service> I<E<lt>yes|noE<gt>>"
11992 #. type: Plain text
11993 #: build/C/man5/nscd.conf.5:231
11995 "When set to I<no> for I<passwd> or I<group> service, then the I<.byname> "
11996 "requests are not added to I<passwd.byuid> or I<group.bygid> cache. This can "
11997 "help with tables containing multiple records for the same ID. The default "
11998 "is yes. This option is valid only for services I<passwd> and I<group>."
12001 #. type: Plain text
12002 #: build/C/man5/nscd.conf.5:239
12004 "The default values stated in this manual page originate from the source code "
12005 "of B<nscd>(8) and are used if not overridden in the configuration file. "
12006 "The default values used in the configuration file of your distribution might "
12010 #. type: Plain text
12011 #: build/C/man5/nscd.conf.5:240
12016 #: build/C/man5/nss.5:19
12021 #. type: Plain text
12022 #: build/C/man5/nss.5:22
12023 msgid "nss - Name Service Switch configuration file"
12026 #. type: Plain text
12027 #: build/C/man5/nss.5:29
12029 "Each call to a function which retrieves data from a system database like the "
12030 "password or group database is handled by the Name Service Switch "
12031 "implementation in the GNU C library. The various services provided are "
12032 "implemented by independent modules, each of which naturally varies widely "
12036 #. type: Plain text
12037 #: build/C/man5/nss.5:38
12039 "The default implementations coming with the GNU C library are by default "
12040 "conservative and do not use unsafe data. This might be very costly in some "
12041 "situations, especially when the databases are large. Some modules allow the "
12042 "system administrator to request taking shortcuts if these are known to be "
12043 "safe. It is then the system administrator's responsibility to ensure the "
12044 "assumption is correct."
12047 #. type: Plain text
12048 #: build/C/man5/nss.5:42
12050 "There are other modules where the implementation changed over time. If an "
12051 "implementation used to sacrifice speed for memory consumption, it might "
12052 "create problems if the preference is switched."
12055 #. type: Plain text
12056 #: build/C/man5/nss.5:51
12058 "The I</etc/default/nss> file contains a number of variable assignments. "
12059 "Each variable controls the behavior of one or more NSS modules. White "
12060 "spaces are ignored. Lines beginning with \\(aq#\\(aq are treated as "
12064 #. type: Plain text
12065 #: build/C/man5/nss.5:53
12066 msgid "The variables currently recognized are:"
12070 #: build/C/man5/nss.5:53
12072 msgid "B<NETID_AUTHORITATIVE => I<TRUE>|I<FALSE>"
12075 #. type: Plain text
12076 #: build/C/man5/nss.5:68
12078 "If set to TRUE, the NIS backend for the B<initgroups>(3) function will "
12079 "accept the information from the I<netid.byname> NIS map as authoritative. "
12080 "This can speed up the function significantly if the I<group.byname> map is "
12081 "large. The content of the I<netid.byname> map is used B<as is>. The system "
12082 "administrator has to make sure it is correctly generated."
12086 #: build/C/man5/nss.5:68
12088 msgid "B<SERVICES_AUTHORITATIVE => I<TRUE>|I<FALSE>"
12091 #. type: Plain text
12092 #: build/C/man5/nss.5:80
12094 "If set to TRUE, the NIS backend for the B<getservbyname>(3) and "
12095 "B<getservbyname_r>(3) functions will assume that the "
12096 "I<services.byservicename> NIS map exists and is authoritative, particularly "
12097 "that it contains both keys with /proto and without /proto for both primary "
12098 "service names and service aliases. The system administrator has to make "
12099 "sure it is correctly generated."
12103 #: build/C/man5/nss.5:80
12105 msgid "B<SETENT_BATCH_READ => I<TRUE>|I<FALSE>"
12108 #. type: Plain text
12109 #: build/C/man5/nss.5:98
12111 "If set to TRUE, the NIS backend for the B<setpwent>(3) and B<setgrent>(3) "
12112 "functions will read the entire database at once and then hand out the "
12113 "requests one by one from memory with every corresponding B<getpwent>(3) or "
12114 "B<getgrent>(3) call respectively. Otherwise, each B<getpwent>(3) or "
12115 "B<getgrent>(3) call might result in a network communication with the server "
12116 "to get the next entry."
12119 #. type: Plain text
12120 #: build/C/man5/nss.5:100
12121 msgid "I</etc/default/nss>"
12124 #. type: Plain text
12125 #: build/C/man5/nss.5:102
12126 msgid "The default configuration corresponds to the following configuration file:"
12130 #. Ulrich Drepper <drepper@redhat.com>
12131 #. type: Plain text
12132 #: build/C/man5/nss.5:110
12135 "NETID_AUTHORITATIVE=FALSE\n"
12136 "SERVICES_AUTHORITATIVE=FALSE\n"
12137 "SETENT_BATCH_READ=FALSE\n"
12140 #. type: Plain text
12141 #: build/C/man5/nss.5:111
12142 msgid "I<nsswitch.conf>"
12146 #: build/C/man5/nsswitch.conf.5:25
12148 msgid "NSSWITCH.CONF"
12151 #. type: Plain text
12152 #: build/C/man5/nsswitch.conf.5:28
12153 msgid "nsswitch.conf - Name Service Switch configuration file"
12156 #. type: Plain text
12157 #: build/C/man5/nsswitch.conf.5:36
12159 "The Name Service Switch (NSS) configuration file, I</etc/nsswitch.conf>, is "
12160 "used by the GNU C Library to determine the sources from which to obtain "
12161 "name-service information in a range of categories, and in what order. Each "
12162 "category of information is identified by a database name."
12165 #. type: Plain text
12166 #: build/C/man5/nsswitch.conf.5:42
12168 "The file is plain ASCII text, with columns separated by spaces or tab "
12169 "characters. The first column specifies the database name. The remaining "
12170 "columns describe the order of sources to query and a limited set of actions "
12171 "that can be performed by lookup result."
12174 #. type: Plain text
12175 #: build/C/man5/nsswitch.conf.5:44
12176 msgid "The following databases are understood by the GNU C Library:"
12179 #. type: Plain text
12180 #: build/C/man5/nsswitch.conf.5:49
12181 msgid "Mail aliases, used by B<getaliasent>(3) and related functions."
12184 #. type: Plain text
12185 #: build/C/man5/nsswitch.conf.5:52
12186 msgid "Ethernet numbers."
12189 #. type: Plain text
12190 #: build/C/man5/nsswitch.conf.5:57
12191 msgid "Groups of users, used by B<getgrent>(3) and related functions."
12194 #. type: Plain text
12195 #: build/C/man5/nsswitch.conf.5:62
12196 msgid "Host names and numbers, used by B<gethostbyname>(3) and related functions."
12199 #. type: Plain text
12200 #: build/C/man5/nsswitch.conf.5:67
12201 msgid "Supplementary group access list, used by B<getgrouplist>(3) function."
12204 #. type: Plain text
12205 #: build/C/man5/nsswitch.conf.5:71
12207 "Network-wide list of hosts and users, used for access rules. C libraries "
12208 "before glibc 2.1 supported netgroups only over NIS."
12211 #. type: Plain text
12212 #: build/C/man5/nsswitch.conf.5:76
12213 msgid "Network names and numbers, used by B<getnetent>(3) and related functions."
12216 #. type: Plain text
12217 #: build/C/man5/nsswitch.conf.5:81
12218 msgid "User passwords, used by B<getpwent>(3) and related functions."
12221 #. type: Plain text
12222 #: build/C/man5/nsswitch.conf.5:86
12223 msgid "Network protocols, used by B<getprotoent>(3) and related functions."
12227 #: build/C/man5/nsswitch.conf.5:86
12229 msgid "B<publickey>"
12232 #. type: Plain text
12233 #: build/C/man5/nsswitch.conf.5:89
12234 msgid "Public and secret keys for Secure_RPC used by NFS and NIS+."
12237 #. type: Plain text
12238 #: build/C/man5/nsswitch.conf.5:94
12240 "Remote procedure call names and numbers, used by B<getrpcbyname>(3) and "
12241 "related functions."
12244 #. type: Plain text
12245 #: build/C/man5/nsswitch.conf.5:99
12246 msgid "Network services, used by B<getservent>(3) and related functions."
12249 #. type: Plain text
12250 #: build/C/man5/nsswitch.conf.5:104
12251 msgid "Shadow user passwords, used by B<getspnam>(3) and related functions."
12254 #. type: Plain text
12255 #: build/C/man5/nsswitch.conf.5:108
12256 msgid "Here is an example I</etc/nsswitch.conf> file:"
12260 #: build/C/man5/nsswitch.conf.5:111
12265 #. type: Plain text
12266 #: build/C/man5/nsswitch.conf.5:114 build/C/man5/nsswitch.conf.5:117 build/C/man5/nsswitch.conf.5:120
12271 #: build/C/man5/nsswitch.conf.5:114
12277 #: build/C/man5/nsswitch.conf.5:117
12283 #: build/C/man5/nsswitch.conf.5:121
12288 #. type: Plain text
12289 #: build/C/man5/nsswitch.conf.5:124
12290 msgid "dns [!UNAVAIL=return] files"
12294 #: build/C/man5/nsswitch.conf.5:124
12299 #. type: Plain text
12300 #: build/C/man5/nsswitch.conf.5:127 build/C/man5/nsswitch.conf.5:130 build/C/man5/nsswitch.conf.5:133 build/C/man5/nsswitch.conf.5:136 build/C/man5/nsswitch.conf.5:139
12301 msgid "nis [NOTFOUND=return] files"
12305 #: build/C/man5/nsswitch.conf.5:127
12311 #: build/C/man5/nsswitch.conf.5:130
12317 #: build/C/man5/nsswitch.conf.5:133
12323 #: build/C/man5/nsswitch.conf.5:136
12328 #. type: Plain text
12329 #: build/C/man5/nsswitch.conf.5:144
12330 msgid "The first column is the database name. The remaining columns specify:"
12333 #. type: Plain text
12334 #: build/C/man5/nsswitch.conf.5:148
12336 "One or more service specifications, for example, \"files\", \"db\", or "
12337 "\"nis\". The order of the services on the line determines the order in "
12338 "which those services will be queried, in turn, until a result is found."
12341 #. type: Plain text
12342 #: build/C/man5/nsswitch.conf.5:151
12344 "Optional actions to perform if a particular result is obtained from the "
12345 "preceding service, for example, \"[NOTFOUND=return]\"."
12348 #. type: Plain text
12349 #: build/C/man5/nsswitch.conf.5:177
12351 "The service specifications supported on your system depend on the presence "
12352 "of shared libraries, and are therefore extensible. Libraries called "
12353 "I</lib/libnss_SERVICE.so.>B<X> will provide the named I<SERVICE>. On a "
12354 "standard installation, you can use \"files\", \"db\", \"nis\", and "
12355 "\"nisplus\". For the B<hosts> database, you can additionally specify "
12356 "\"dns\". For the B<passwd>, B<group>, and B<shadow> databases, you can "
12357 "additionally specify \"compat\" (see B<Compatibility mode> below). The "
12358 "version number B<X> may be 1 for glibc 2.0, or 2 for glibc 2.1 and later. "
12359 "On systems with additional libraries installed, you may have access to "
12360 "further services such as \"hesiod\", \"ldap\", \"winbind\" and \"wins\"."
12363 #. type: Plain text
12364 #: build/C/man5/nsswitch.conf.5:182
12366 "An action may also be specified following a service specification. The "
12367 "action modifies the behavior following a result obtained from the preceding "
12368 "data source. Action items take the general form:"
12371 #. type: Plain text
12372 #: build/C/man5/nsswitch.conf.5:185
12373 msgid "[I<STATUS>=I<ACTION>]"
12376 #. type: Plain text
12377 #: build/C/man5/nsswitch.conf.5:187
12378 msgid "[!I<STATUS>=I<ACTION>]"
12381 #. type: Plain text
12382 #: build/C/man5/nsswitch.conf.5:190
12386 #. type: Plain text
12387 #: build/C/man5/nsswitch.conf.5:201
12388 msgid "I<STATUS> =E<gt> B<success> | B<notfound> | B<unavail> | B<tryagain>"
12391 #. type: Plain text
12392 #: build/C/man5/nsswitch.conf.5:207
12393 msgid "I<ACTION> =E<gt> B<return> | B<continue>"
12396 #. type: Plain text
12397 #: build/C/man5/nsswitch.conf.5:212
12399 "The ! negates the test, matching all possible results except the one "
12400 "specified. The case of the keywords is not significant."
12403 #. type: Plain text
12404 #: build/C/man5/nsswitch.conf.5:217
12406 "The I<STATUS> value is matched against the result of the lookup function "
12407 "called by the preceding service specification, and can be one of:"
12411 #: build/C/man5/nsswitch.conf.5:218
12416 #. type: Plain text
12417 #: build/C/man5/nsswitch.conf.5:222
12419 "No error occurred and the requested entry is returned. The default action "
12420 "for this condition is \"return\"."
12424 #: build/C/man5/nsswitch.conf.5:222
12426 msgid "B<notfound>"
12429 #. type: Plain text
12430 #: build/C/man5/nsswitch.conf.5:226
12432 "The lookup succeeded, but the requested entry was not found. The default "
12433 "action for this condition is \"continue\"."
12437 #: build/C/man5/nsswitch.conf.5:226
12442 #. type: Plain text
12443 #: build/C/man5/nsswitch.conf.5:233
12445 "The service is permanently unavailable. This can mean either that the "
12446 "required file cannot be read, or, for network services, that the server is "
12447 "not available or does not allow queries. The default action for this "
12448 "condition is \"continue\"."
12452 #: build/C/man5/nsswitch.conf.5:233
12454 msgid "B<tryagain>"
12457 #. type: Plain text
12458 #: build/C/man5/nsswitch.conf.5:239
12460 "The service is temporarily unavailable. This could mean a file is locked or "
12461 "a server currently cannot accept more connections. The default action for "
12462 "this condition is \"continue\"."
12465 #. type: Plain text
12466 #: build/C/man5/nsswitch.conf.5:244
12467 msgid "The I<ACTION> value can be one of:"
12471 #: build/C/man5/nsswitch.conf.5:245
12476 #. type: Plain text
12477 #: build/C/man5/nsswitch.conf.5:257
12479 "Return a result now. Do not call any further lookup functions. However, "
12480 "for compatibility reasons, if this is the selected action for the B<group> "
12481 "database and the B<notfound> status, and the configuration file does not "
12482 "contain the B<initgroups> line, the next lookup function is always called, "
12483 "without affecting the search result."
12487 #: build/C/man5/nsswitch.conf.5:257
12489 msgid "B<continue>"
12492 #. type: Plain text
12493 #: build/C/man5/nsswitch.conf.5:260
12494 msgid "Call the next lookup function."
12498 #: build/C/man5/nsswitch.conf.5:261
12500 msgid "Compatibility mode (compat)"
12503 #. type: Plain text
12504 #: build/C/man5/nsswitch.conf.5:267
12506 "The NSS \"compat\" service is similar to \"files\" except that it "
12507 "additionally permits special entries in I</etc/passwd> for granting users or "
12508 "members of netgroups access to the system. The following entries are valid "
12513 #: build/C/man5/nsswitch.conf.5:268
12515 msgid "B<+>I<user>"
12518 #. type: Plain text
12519 #: build/C/man5/nsswitch.conf.5:273
12520 msgid "Include the specified I<user> from the NIS passwd map."
12524 #: build/C/man5/nsswitch.conf.5:273
12526 msgid "B<+@>I<netgroup>"
12529 #. type: Plain text
12530 #: build/C/man5/nsswitch.conf.5:277
12531 msgid "Include all users in the given I<netgroup>."
12535 #: build/C/man5/nsswitch.conf.5:277
12537 msgid "B<->I<user>"
12540 #. type: Plain text
12541 #: build/C/man5/nsswitch.conf.5:282
12542 msgid "Exclude the specified I<user> from the NIS passwd map."
12546 #: build/C/man5/nsswitch.conf.5:282
12548 msgid "B<-@>I<netgroup>"
12551 #. type: Plain text
12552 #: build/C/man5/nsswitch.conf.5:286
12553 msgid "Exclude all users in the given I<netgroup>."
12557 #: build/C/man5/nsswitch.conf.5:286
12562 #. type: Plain text
12563 #: build/C/man5/nsswitch.conf.5:290
12565 "Include every user, except previously excluded ones, from the NIS passwd "
12569 #. type: Plain text
12570 #: build/C/man5/nsswitch.conf.5:298
12572 "By default the source is \"nis\", but this may be overridden by specifying "
12573 "\"nisplus\" as the source for the pseudo-databases B<passwd_compat>, "
12574 "B<group_compat>, and B<shadow_compat>."
12577 #. type: Plain text
12578 #: build/C/man5/nsswitch.conf.5:305
12580 "A service named I<SERVICE> is implemented by a shared object library named "
12581 "I<libnss_SERVICE.so.>B<X> that resides in I</lib>."
12584 #. type: Plain text
12585 #: build/C/man5/nsswitch.conf.5:310
12586 msgid "NSS configuration file."
12590 #: build/C/man5/nsswitch.conf.5:310
12592 msgid "I</lib/libnss_compat.so.>B<X>"
12595 #. type: Plain text
12596 #: build/C/man5/nsswitch.conf.5:313
12597 msgid "implements \"compat\" source."
12601 #: build/C/man5/nsswitch.conf.5:313
12603 msgid "I</lib/libnss_db.so.>B<X>"
12606 #. type: Plain text
12607 #: build/C/man5/nsswitch.conf.5:316
12608 msgid "implements \"db\" source."
12612 #: build/C/man5/nsswitch.conf.5:316
12614 msgid "I</lib/libnss_dns.so.>B<X>"
12617 #. type: Plain text
12618 #: build/C/man5/nsswitch.conf.5:319
12619 msgid "implements \"dns\" source."
12623 #: build/C/man5/nsswitch.conf.5:319
12625 msgid "I</lib/libnss_files.so.>B<X>"
12628 #. type: Plain text
12629 #: build/C/man5/nsswitch.conf.5:322
12630 msgid "implements \"files\" source."
12634 #: build/C/man5/nsswitch.conf.5:322
12636 msgid "I</lib/libnss_hesiod.so.>B<X>"
12639 #. type: Plain text
12640 #: build/C/man5/nsswitch.conf.5:325
12641 msgid "implements \"hesiod\" source."
12645 #: build/C/man5/nsswitch.conf.5:325
12647 msgid "I</lib/libnss_nis.so.>B<X>"
12650 #. type: Plain text
12651 #: build/C/man5/nsswitch.conf.5:328
12652 msgid "implements \"nis\" source."
12656 #: build/C/man5/nsswitch.conf.5:328
12658 msgid "I</lib/libnss_nisplus.so.>B<X>"
12661 #. type: Plain text
12662 #: build/C/man5/nsswitch.conf.5:331
12663 msgid "implements \"nisplus\" source."
12666 #. type: Plain text
12667 #: build/C/man5/nsswitch.conf.5:339
12669 "Within each process that uses B<nsswitch.conf>, the entire file is read only "
12670 "once. If the file is later changed, the process will continue using the old "
12674 #. type: Plain text
12675 #: build/C/man5/nsswitch.conf.5:352
12677 "Traditionally, there was only a single source for service information, often "
12678 "in the form of a single configuration file (e.g., I</etc/passwd>). However, "
12679 "as other name services, such as the Network Information Service (NIS) and "
12680 "the Domain Name Service (DNS), became popular, a method was needed that "
12681 "would be more flexible than fixed search orders coded into the C library. "
12682 "The Name Service Switch mechanism, which was based on the mechanism used by "
12683 "Sun Microsystems in the Solaris 2 C library, introduced a cleaner solution "
12687 #. type: Plain text
12688 #: build/C/man5/nsswitch.conf.5:354
12689 msgid "B<getent>(1), B<nss>(5)"
12693 #: build/C/man7/packet.7:12
12698 #. type: Plain text
12699 #: build/C/man7/packet.7:15
12700 msgid "packet - packet interface on device level"
12703 #. type: Plain text
12704 #: build/C/man7/packet.7:18
12706 msgid "B<#include E<lt>sys/socket.hE<gt>>\n"
12709 #. type: Plain text
12710 #: build/C/man7/packet.7:20
12712 msgid "B<#include E<lt>linux/if_packet.hE<gt>>\n"
12715 #. type: Plain text
12716 #: build/C/man7/packet.7:22
12718 msgid "B<#include E<lt>net/ethernet.hE<gt> /* the L2 protocols */>\n"
12721 #. type: Plain text
12722 #: build/C/man7/packet.7:24
12725 "B<packet_socket = socket(AF_PACKET, int >I<socket_type>B<, int "
12726 ">I<protocol>B<);>\n"
12729 #. type: Plain text
12730 #: build/C/man7/packet.7:30
12732 "Packet sockets are used to receive or send raw packets at the device driver "
12733 "(OSI Layer 2) level. They allow the user to implement protocol modules in "
12734 "user space on top of the physical layer."
12737 #. type: Plain text
12738 #: build/C/man7/packet.7:51
12740 "The I<socket_type> is either B<SOCK_RAW> for raw packets including the "
12741 "link-level header or B<SOCK_DGRAM> for cooked packets with the link-level "
12742 "header removed. The link-level header information is available in a common "
12743 "format in a I<sockaddr_ll>. I<protocol> is the IEEE 802.3 protocol number "
12744 "in network byte order. See the I<E<lt>linux/if_ether.hE<gt>> include file "
12745 "for a list of allowed protocols. When protocol is set to "
12746 "B<htons(ETH_P_ALL)> then all protocols are received. All incoming packets "
12747 "of that protocol type will be passed to the packet socket before they are "
12748 "passed to the protocols implemented in the kernel."
12751 #. type: Plain text
12752 #: build/C/man7/packet.7:55
12754 "Only processes with effective UID 0 or the B<CAP_NET_RAW> capability may "
12755 "open packet sockets."
12758 #. type: Plain text
12759 #: build/C/man7/packet.7:73
12761 "B<SOCK_RAW> packets are passed to and from the device driver without any "
12762 "changes in the packet data. When receiving a packet, the address is still "
12763 "parsed and passed in a standard I<sockaddr_ll> address structure. When "
12764 "transmitting a packet, the user supplied buffer should contain the physical "
12765 "layer header. That packet is then queued unmodified to the network driver "
12766 "of the interface defined by the destination address. Some device drivers "
12767 "always add other headers. B<SOCK_RAW> is similar to but not compatible with "
12768 "the obsolete B<AF_INET/SOCK_PACKET> of Linux 2.0."
12771 #. type: Plain text
12772 #: build/C/man7/packet.7:83
12774 "B<SOCK_DGRAM> operates on a slightly higher level. The physical header is "
12775 "removed before the packet is passed to the user. Packets sent through a "
12776 "B<SOCK_DGRAM> packet socket get a suitable physical layer header based on "
12777 "the information in the I<sockaddr_ll> destination address before they are "
12781 #. type: Plain text
12782 #: build/C/man7/packet.7:96
12784 "By default all packets of the specified protocol type are passed to a packet "
12785 "socket. To get packets only from a specific interface use B<bind>(2) "
12786 "specifying an address in a I<struct sockaddr_ll> to bind the packet socket "
12787 "to an interface. Only the I<sll_protocol> and the I<sll_ifindex> address "
12788 "fields are used for purposes of binding."
12791 #. type: Plain text
12792 #: build/C/man7/packet.7:100
12793 msgid "The B<connect>(2) operation is not supported on packet sockets."
12796 #. type: Plain text
12797 #: build/C/man7/packet.7:109
12799 "When the B<MSG_TRUNC> flag is passed to B<recvmsg>(2), B<recv>(2), "
12800 "B<recvfrom>(2) the real length of the packet on the wire is always "
12801 "returned, even when it is longer than the buffer."
12805 #: build/C/man7/packet.7:109
12807 msgid "Address types"
12810 #. type: Plain text
12811 #: build/C/man7/packet.7:113
12812 msgid "The I<sockaddr_ll> is a device independent physical layer address."
12815 #. type: Plain text
12816 #: build/C/man7/packet.7:125
12819 "struct sockaddr_ll {\n"
12820 " unsigned short sll_family; /* Always AF_PACKET */\n"
12821 " unsigned short sll_protocol; /* Physical layer protocol */\n"
12822 " int sll_ifindex; /* Interface number */\n"
12823 " unsigned short sll_hatype; /* ARP hardware type */\n"
12824 " unsigned char sll_pkttype; /* Packet type */\n"
12825 " unsigned char sll_halen; /* Length of address */\n"
12826 " unsigned char sll_addr[8]; /* Physical layer address */\n"
12830 #. type: Plain text
12831 #: build/C/man7/packet.7:164
12833 "I<sll_protocol> is the standard ethernet protocol type in network byte order "
12834 "as defined in the I<E<lt>linux/if_ether.hE<gt>> include file. It defaults "
12835 "to the socket's protocol. I<sll_ifindex> is the interface index of the "
12836 "interface (see B<netdevice>(7)); 0 matches any interface (only permitted for "
12837 "binding). I<sll_hatype> is an ARP type as defined in the "
12838 "I<E<lt>linux/if_arp.hE<gt>> include file. I<sll_pkttype> contains the "
12839 "packet type. Valid types are B<PACKET_HOST> for a packet addressed to the "
12840 "local host, B<PACKET_BROADCAST> for a physical layer broadcast packet, "
12841 "B<PACKET_MULTICAST> for a packet sent to a physical layer multicast address, "
12842 "B<PACKET_OTHERHOST> for a packet to some other host that has been caught by "
12843 "a device driver in promiscuous mode, and B<PACKET_OUTGOING> for a packet "
12844 "originated from the local host that is looped back to a packet socket. "
12845 "These types make sense only for receiving. I<sll_addr> and I<sll_halen> "
12846 "contain the physical layer (e.g., IEEE 802.3) address and its length. The "
12847 "exact interpretation depends on the device."
12850 #. type: Plain text
12851 #: build/C/man7/packet.7:180
12853 "When you send packets it is enough to specify I<sll_family>, I<sll_addr>, "
12854 "I<sll_halen>, I<sll_ifindex>. The other fields should be 0. I<sll_hatype> "
12855 "and I<sll_pkttype> are set on received packets for your information. For "
12856 "bind only I<sll_protocol> and I<sll_ifindex> are used."
12859 #. type: Plain text
12860 #: build/C/man7/packet.7:185
12862 "Packet socket options are configured by calling B<setsockopt>(2) with level "
12867 #: build/C/man7/packet.7:185
12869 msgid "B<PACKET_ADD_MEMBERSHIP>"
12873 #: build/C/man7/packet.7:188
12875 msgid "B<PACKET_DROP_MEMBERSHIP>"
12878 #. type: Plain text
12879 #: build/C/man7/packet.7:200
12881 "Packet sockets can be used to configure physical layer multicasting and "
12882 "promiscuous mode. B<PACKET_ADD_MEMBERSHIP> adds a binding and "
12883 "B<PACKET_DROP_MEMBERSHIP> drops it. They both expect a I<packet_mreq> "
12884 "structure as argument:"
12887 #. type: Plain text
12888 #: build/C/man7/packet.7:209
12891 "struct packet_mreq {\n"
12892 " int mr_ifindex; /* interface index */\n"
12893 " unsigned short mr_type; /* action */\n"
12894 " unsigned short mr_alen; /* address length */\n"
12895 " unsigned char mr_address[8]; /* physical layer address */\n"
12899 #. type: Plain text
12900 #: build/C/man7/packet.7:230
12902 "B<mr_ifindex> contains the interface index for the interface whose status "
12903 "should be changed. The B<mr_type> parameter specifies which action to "
12904 "perform. B<PACKET_MR_PROMISC> enables receiving all packets on a shared "
12905 "medium (often known as \"promiscuous mode\"), B<PACKET_MR_MULTICAST> binds "
12906 "the socket to the physical layer multicast group specified in B<mr_address> "
12907 "and B<mr_alen>, and B<PACKET_MR_ALLMULTI> sets the socket up to receive all "
12908 "multicast packets arriving at the interface."
12911 #. type: Plain text
12912 #: build/C/man7/packet.7:236
12914 "In addition, the traditional ioctls B<SIOCSIFFLAGS>, B<SIOCADDMULTI>, "
12915 "B<SIOCDELMULTI> can be used for the same purpose."
12919 #: build/C/man7/packet.7:236
12921 msgid "B<PACKET_AUXDATA> (since Linux 2.6.21)"
12924 #. commit 8dc4194474159660d7f37c495e3fc3f10d0db8cc
12925 #. type: Plain text
12926 #: build/C/man7/packet.7:246
12928 "If this binary option is enabled, the packet socket passes a metadata "
12929 "structure along with each packet in the B<recvmsg>(2) control field. The "
12930 "structure can be read with B<cmsg>(3). It is defined as"
12933 #. type: Plain text
12934 #: build/C/man7/packet.7:258
12937 "struct tpacket_auxdata {\n"
12938 " __u32 tp_status;\n"
12939 " __u32 tp_len; /* packet length */\n"
12940 " __u32 tp_snaplen; /* captured length */\n"
12943 " __u16 tp_vlan_tci;\n"
12944 " __u16 tp_padding;\n"
12949 #: build/C/man7/packet.7:260
12951 msgid "B<PACKET_FANOUT> (since Linux 3.1)"
12954 #. commit dc99f600698dcac69b8f56dda9a8a00d645c5ffc
12955 #. type: Plain text
12956 #: build/C/man7/packet.7:282
12958 "To scale processing across threads, packet sockets can form a fanout group. "
12959 "In this mode, each matching packet is enqueued onto only one socket in the "
12960 "group. A socket joins a fanout group by calling B<setsockopt>(2) with "
12961 "level B<SOL_PACKET> and option B<PACKET_FANOUT>. Each network namespace can "
12962 "have up to 65536 independent groups. A socket selects a group by encoding "
12963 "the ID in the first 16 bits of the integer option value. The first packet "
12964 "socket to join a group implicitly creates it. To successfully join an "
12965 "existing group, subsequent packet sockets must have the same protocol, "
12966 "device settings, fanout mode and flags (see below). Packet sockets can "
12967 "leave a fanout group only by closing the socket. The group is deleted when "
12968 "the last socket is closed."
12971 #. commit 2d36097d26b5991d71a2cf4a20c1a158f0f1bfcd
12972 #. type: Plain text
12973 #: build/C/man7/packet.7:305
12975 "Fanout supports multiple algorithms to spread traffic between sockets. The "
12976 "default mode, B<PACKET_FANOUT_HASH>, sends packets from the same flow to the "
12977 "same socket to maintain per-flow ordering. For each packet, it chooses a "
12978 "socket by taking the packet flow hash modulo the number of sockets in the "
12979 "group, where a flow hash is a hash over network-layer address and optional "
12980 "transport-layer port fields. The load-balance mode B<PACKET_FANOUT_LB> "
12981 "implements a round-robin algorithm. B<PACKET_FANOUT_CPU> selects the socket "
12982 "based on the CPU that the packet arrived on. B<PACKET_FANOUT_ROLLOVER> "
12983 "processes all data on a single socket, moves to the next when one becomes "
12984 "backlogged. B<PACKET_FANOUT_RND> selects the socket using a pseudo-random "
12985 "number generator. B<PACKET_FANOUT_QM> (available since Linux 3.14) selects "
12986 "the socket using the recorded queue_mapping of the received skb."
12989 #. type: Plain text
12990 #: build/C/man7/packet.7:320
12992 "Fanout modes can take additional options. IP fragmentation causes packets "
12993 "from the same flow to have different flow hashes. The flag "
12994 "B<PACKET_FANOUT_FLAG_DEFRAG>, if set, causes packet to be defragmented "
12995 "before fanout is applied, to preserve order even in this case. Fanout mode "
12996 "and options are communicated in the second 16 bits of the integer option "
12997 "value. The flag B<PACKET_FANOUT_FLAG_ROLLOVER> enables the roll over "
12998 "mechanism as a backup strategy: if the original fanout algorithm selects a "
12999 "backlogged socket, the packet rolls over to the next available one."
13003 #: build/C/man7/packet.7:320
13005 msgid "B<PACKET_LOSS> (with B<PACKET_TX_RING>)"
13008 #. type: Plain text
13009 #: build/C/man7/packet.7:343
13011 "When a malformed packet is encountered on a transmit ring, the default is to "
13012 "reset its I<tp_status> to B<TP_STATUS_WRONG_FORMAT> and abort the "
13013 "transmission immediately. The malformed packet blocks itself and "
13014 "subsequently enqueued packets from being sent. The format error must be "
13015 "fixed, the associated I<tp_status> reset to B<TP_STATUS_SEND_REQUEST>, and "
13016 "the transmission process restarted via B<send>(2). However, if "
13017 "B<PACKET_LOSS> is set, any malformed packet will be skipped, its "
13018 "I<tp_status> reset to B<TP_STATUS_AVAILABLE>, and the transmission process "
13023 #: build/C/man7/packet.7:343
13025 msgid "B<PACKET_RESERVE> (with B<PACKET_RX_RING>)"
13028 #. type: Plain text
13029 #: build/C/man7/packet.7:348
13031 "By default, a packet receive ring writes packets immediately following the "
13032 "metadata structure and alignment padding. This integer option reserves "
13033 "additional headroom."
13037 #: build/C/man7/packet.7:348
13039 msgid "B<PACKET_RX_RING>"
13042 #. type: Plain text
13043 #: build/C/man7/packet.7:394
13045 "Create a memory-mapped ring buffer for asynchronous packet reception. The "
13046 "packet socket reserves a contiguous region of application address space, "
13047 "lays it out into an array of packet slots and copies packets (up to "
13048 "I<tp_snaplen>) into subsequent slots. Each packet is preceded by a "
13049 "metadata structure similar to I<tpacket_auxdata>. The protocol fields "
13050 "encode the offset to the data from the start of the metadata header. "
13051 "I<tp_net> stores the offset to the network layer. If the packet socket is "
13052 "of type B<SOCK_DGRAM>, then I<tp_mac> is the same. If it is of type "
13053 "B<SOCK_RAW>, then that field stores the offset to the link-layer frame. "
13054 "Packet socket and application communicate the head and tail of the ring "
13055 "through the I<tp_status> field. The packet socket owns all slots with "
13056 "I<tp_status> equal to B<TP_STATUS_KERNEL>. After filling a slot, it changes "
13057 "the status of the slot to transfer ownership to the application. During "
13058 "normal operation, the new I<tp_status> value has at least the "
13059 "B<TP_STATUS_USER> bit set to signal that a received packet has been stored. "
13060 "When the application has finished processing a packet, it transfers "
13061 "ownership of the slot back to the socket by setting I<tp_status> equal to "
13062 "B<TP_STATUS_KERNEL>. Packet sockets implement multiple variants of the "
13063 "packet ring. The implementation details are described in "
13064 "I<Documentation/networking/packet_mmap.txt> in the Linux kernel source tree."
13068 #: build/C/man7/packet.7:394
13070 msgid "B<PACKET_STATISTICS>"
13073 #. type: Plain text
13074 #: build/C/man7/packet.7:397
13075 msgid "Retrieve packet socket statistics in the form of a structure"
13078 #. type: Plain text
13079 #: build/C/man7/packet.7:404
13082 "struct tpacket_stats {\n"
13083 " unsigned int tp_packets; /* Total packet count */\n"
13084 " unsigned int tp_drops; /* Dropped packet count */\n"
13088 #. type: Plain text
13089 #: build/C/man7/packet.7:410
13091 "Receiving statistics resets the internal counters. The statistics structure "
13092 "differs when using a ring of variant B<TPACKET_V3>."
13096 #: build/C/man7/packet.7:410
13098 msgid "B<PACKET_TIMESTAMP> (with B<PACKET_RX_RING>; since Linux 2.6.36)"
13101 #. commit 614f60fa9d73a9e8fdff3df83381907fea7c5649
13102 #. type: Plain text
13103 #: build/C/man7/packet.7:420
13105 "The packet receive ring always stores a timestamp in the metadata header. "
13106 "By default, this is a software generated timestamp generated when the packet "
13107 "is copied into the ring. This integer option selects the type of "
13108 "timestamp. Besides the default, it support the two hardware formats "
13109 "described in I<Documentation/networking/timestamping.txt> in the Linux "
13110 "kernel source tree."
13114 #: build/C/man7/packet.7:420
13116 msgid "B<PACKET_TX_RING> (since Linux 2.6.31)"
13119 #. commit 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1
13120 #. type: Plain text
13121 #: build/C/man7/packet.7:455
13123 "Create a memory-mapped ring buffer for packet transmission. This option is "
13124 "similar to B<PACKET_RX_RING> and takes the same arguments. The application "
13125 "writes packets into slots with I<tp_status> equal to B<TP_STATUS_AVAILABLE> "
13126 "and schedules them for transmission by changing I<tp_status> to "
13127 "B<TP_STATUS_SEND_REQUEST>. When packets are ready to be transmitted, the "
13128 "application calls B<send>(2) or a variant thereof. The I<buf> and I<len> "
13129 "fields of this call are ignored. If an address is passed using B<sendto>(2) "
13130 "or B<sendmsg>(2), then that overrides the socket default. On successful "
13131 "transmission, the socket resets I<tp_status> to B<TP_STATUS_AVAILABLE>. It "
13132 "immediately aborts the transmission on error unless B<PACKET_LOSS> is set."
13136 #: build/C/man7/packet.7:455
13138 msgid "B<PACKET_VERSION> (with B<PACKET_RX_RING>; since Linux 2.6.27)"
13141 #. commit bbd6ef87c544d88c30e4b762b1b61ef267a7d279
13142 #. type: Plain text
13143 #: build/C/man7/packet.7:464
13145 "By default, B<PACKET_RX_RING> creates a packet receive ring of variant "
13146 "B<TPACKET_V1>. To create another variant, configure the desired variant by "
13147 "setting this integer option before creating the ring."
13151 #: build/C/man7/packet.7:464
13153 msgid "B<PACKET_QDISC_BYPASS> (since Linux 3.14)"
13156 #. commit d346a3fae3ff1d99f5d0c819bf86edf9094a26a1
13157 #. type: Plain text
13158 #: build/C/man7/packet.7:479
13160 "By default, packets sent through packet sockets pass through the kernel's "
13161 "qdisc (traffic control) layer, which is fine for the vast majority of use "
13162 "cases. For traffic generator appliances using packet sockets that intend to "
13163 "brute-force flood the network\\(emfor example, to test devices under load in "
13164 "a similar fashion to pktgen\\(emthis layer can be bypassed by setting this "
13165 "integer option to 1. A side effect is that packet buffering in the qdisc "
13166 "layer is avoided, which will lead to increased drops when network device "
13167 "transmit queues are busy; therefore, use at your own risk."
13170 #. FIXME Document SIOCGSTAMPNS
13171 #. type: Plain text
13172 #: build/C/man7/packet.7:486
13174 "B<SIOCGSTAMP> can be used to receive the timestamp of the last received "
13175 "packet. Argument is a I<struct timeval> variable."
13178 #. type: Plain text
13179 #: build/C/man7/packet.7:492
13181 "In addition, all standard ioctls defined in B<netdevice>(7) and "
13182 "B<socket>(7) are valid on packet sockets."
13186 #: build/C/man7/packet.7:492 build/C/man7/raw.7:131 build/C/man7/tcp.7:1210 build/C/man7/udp.7:103
13188 msgid "Error handling"
13191 #. type: Plain text
13192 #: build/C/man7/packet.7:496
13194 "Packet sockets do no error handling other than errors occurred while passing "
13195 "the packet to the device driver. They don't have the concept of a pending "
13199 #. type: Plain text
13200 #: build/C/man7/packet.7:500
13201 msgid "Unknown multicast group address passed."
13204 #. type: Plain text
13205 #: build/C/man7/packet.7:503
13206 msgid "User passed invalid memory address."
13209 #. type: Plain text
13210 #: build/C/man7/packet.7:506 build/C/man7/raw.7:155
13211 msgid "Invalid argument."
13214 #. type: Plain text
13215 #: build/C/man7/packet.7:509
13216 msgid "Packet is bigger than interface MTU."
13220 #: build/C/man7/packet.7:509
13222 msgid "B<ENETDOWN>"
13225 #. type: Plain text
13226 #: build/C/man7/packet.7:512
13227 msgid "Interface is not up."
13230 #. type: Plain text
13231 #: build/C/man7/packet.7:515
13232 msgid "Not enough memory to allocate the packet."
13235 #. type: Plain text
13236 #: build/C/man7/packet.7:518
13237 msgid "Unknown device name or interface index specified in interface address."
13240 #. type: Plain text
13241 #: build/C/man7/packet.7:521
13242 msgid "No packet received."
13245 #. type: Plain text
13246 #: build/C/man7/packet.7:524
13247 msgid "No interface address passed."
13251 #: build/C/man7/packet.7:524
13256 #. type: Plain text
13257 #: build/C/man7/packet.7:527
13258 msgid "Interface address contained an invalid interface index."
13261 #. type: Plain text
13262 #: build/C/man7/packet.7:530
13263 msgid "User has insufficient privileges to carry out this operation."
13266 #. type: Plain text
13267 #: build/C/man7/packet.7:532
13268 msgid "In addition, other errors may be generated by the low-level driver."
13271 #. type: Plain text
13272 #: build/C/man7/packet.7:537
13274 "B<AF_PACKET> is a new feature in Linux 2.2. Earlier Linux versions "
13275 "supported only B<SOCK_PACKET>."
13278 #. type: Plain text
13279 #: build/C/man7/packet.7:546
13281 "For portable programs it is suggested to use B<AF_PACKET> via B<pcap>(3); "
13282 "although this covers only a subset of the B<AF_PACKET> features."
13285 #. type: Plain text
13286 #: build/C/man7/packet.7:567
13288 "The B<SOCK_DGRAM> packet sockets make no attempt to create or parse the IEEE "
13289 "802.2 LLC header for a IEEE 802.3 frame. When B<ETH_P_802_3> is specified "
13290 "as protocol for sending the kernel creates the 802.3 frame and fills out the "
13291 "length field; the user has to supply the LLC header to get a fully "
13292 "conforming packet. Incoming 802.3 packets are not multiplexed on the "
13293 "DSAP/SSAP protocol fields; instead they are supplied to the user as protocol "
13294 "B<ETH_P_802_2> with the LLC header prefixed. It is thus not possible to "
13295 "bind to B<ETH_P_802_3>; bind to B<ETH_P_802_2> instead and do the protocol "
13296 "multiplex yourself. The default for sending is the standard Ethernet DIX "
13297 "encapsulation with the protocol filled in."
13300 #. type: Plain text
13301 #: build/C/man7/packet.7:569
13302 msgid "Packet sockets are not subject to the input or output firewall chains."
13305 #. type: Plain text
13306 #: build/C/man7/packet.7:579
13308 "In Linux 2.0, the only way to get a packet socket was by calling "
13309 "B<socket(AF_INET, SOCK_PACKET, >I<protocol>B<)>. This is still supported "
13310 "but strongly deprecated. The main difference between the two methods is "
13311 "that B<SOCK_PACKET> uses the old I<struct sockaddr_pkt> to specify an "
13312 "interface, which doesn't provide physical layer independence."
13315 #. type: Plain text
13316 #: build/C/man7/packet.7:587
13319 "struct sockaddr_pkt {\n"
13320 " unsigned short spkt_family;\n"
13321 " unsigned char spkt_device[14];\n"
13322 " unsigned short spkt_protocol;\n"
13326 #. type: Plain text
13327 #: build/C/man7/packet.7:599
13329 "I<spkt_family> contains the device type, I<spkt_protocol> is the IEEE 802.3 "
13330 "protocol type as defined in I<E<lt>sys/if_ether.hE<gt>> and I<spkt_device> "
13331 "is the device name as a null-terminated string, for example, eth0."
13334 #. type: Plain text
13335 #: build/C/man7/packet.7:601
13336 msgid "This structure is obsolete and should not be used in new code."
13339 #. type: Plain text
13340 #: build/C/man7/packet.7:605
13342 "glibc 2.1 does not have a define for B<SOL_PACKET>. The suggested "
13343 "workaround is to use:"
13346 #. type: Plain text
13347 #: build/C/man7/packet.7:611
13350 "#ifndef SOL_PACKET\n"
13351 "#define SOL_PACKET 263\n"
13355 #. type: Plain text
13356 #: build/C/man7/packet.7:615
13357 msgid "This is fixed in later glibc versions."
13360 #. type: Plain text
13361 #: build/C/man7/packet.7:617
13362 msgid "The IEEE 802.2/803.3 LLC handling could be considered as a bug."
13365 #. type: Plain text
13366 #: build/C/man7/packet.7:619
13367 msgid "Socket filters are not documented."
13371 #. This man page was written by Andi Kleen with help from Matthew Wilcox.
13372 #. AF_PACKET in Linux 2.2 was implemented
13373 #. by Alexey Kuznetsov, based on code by Alan Cox and others.
13374 #. type: Plain text
13375 #: build/C/man7/packet.7:631
13377 "The B<MSG_TRUNC> B<recvmsg>(2) extension is an ugly hack and should be "
13378 "replaced by a control message. There is currently no way to get the "
13379 "original destination address of packets via B<SOCK_DGRAM>."
13382 #. type: Plain text
13383 #: build/C/man7/packet.7:638
13385 "B<socket>(2), B<pcap>(3), B<capabilities>(7), B<ip>(7), B<raw>(7), "
13389 #. type: Plain text
13390 #: build/C/man7/packet.7:641
13392 "RFC\\ 894 for the standard IP Ethernet encapsulation. RFC\\ 1700 for the "
13393 "IEEE 802.3 IP encapsulation."
13396 #. type: Plain text
13397 #: build/C/man7/packet.7:645
13398 msgid "The I<E<lt>linux/if_ether.hE<gt>> include file for physical layer protocols."
13401 #. type: Plain text
13402 #: build/C/man7/packet.7:653
13404 "The Linux kernel source tree. I</Documentation/networking/filter.txt> "
13405 "describes how to apply Berkeley Packet Filters to packet sockets. "
13406 "I</tools/testing/selftests/net/psock_tpacket.c> contains example source code "
13407 "for all available versions of B<PACKET_RX_RING> and B<PACKET_TX_RING>."
13411 #: build/C/man5/protocols.5:29
13417 #: build/C/man5/protocols.5:29 build/C/man7/x25.7:12
13422 #. type: Plain text
13423 #: build/C/man5/protocols.5:32
13424 msgid "protocols - protocols definition file"
13427 #. type: Plain text
13428 #: build/C/man5/protocols.5:40
13430 "This file is a plain ASCII file, describing the various DARPA internet "
13431 "protocols that are available from the TCP/IP subsystem. It should be "
13432 "consulted instead of using the numbers in the ARPA include files, or, even "
13433 "worse, just guessing them. These numbers will occur in the protocol field "
13434 "of any IP header."
13437 #. .. by the DDN Network Information Center.
13438 #. type: Plain text
13439 #: build/C/man5/protocols.5:46
13441 "Keep this file untouched since changes would result in incorrect IP "
13442 "packages. Protocol numbers and names are specified by the IANA (Internet "
13443 "Assigned Numbers Authority)."
13446 #. type: Plain text
13447 #: build/C/man5/protocols.5:48
13448 msgid "Each line is of the following format:"
13451 #. type: Plain text
13452 #: build/C/man5/protocols.5:51
13453 msgid "I<protocol number aliases ...>"
13456 #. type: Plain text
13457 #: build/C/man5/protocols.5:57
13459 "where the fields are delimited by spaces or tabs. Empty lines are ignored. "
13460 "If a line contains a hash mark (#), the hash mark and the part of the line "
13461 "following it are ignored."
13465 #: build/C/man5/protocols.5:59 build/C/man5/services.5:109
13467 msgid "I<protocol>"
13470 #. type: Plain text
13471 #: build/C/man5/protocols.5:67
13472 msgid "the native name for the protocol. For example I<ip>, I<tcp>, or I<udp>."
13475 #. type: Plain text
13476 #: build/C/man5/protocols.5:71
13478 "the official number for this protocol as it will appear within the IP "
13482 #. type: Plain text
13483 #: build/C/man5/protocols.5:74
13484 msgid "optional aliases for the protocol."
13487 #. The following is not true as at glibc 2.8 (a line with a comma is
13488 #. ignored by getservent()); it's not clear if/when it was ever true.
13489 #. As a backward compatibility feature, the slash (/) between the
13493 #. name can in fact be either a slash or a comma (,).
13494 #. Use of the comma in
13495 #. modern installations is deprecated.
13496 #. type: Plain text
13497 #: build/C/man5/protocols.5:77 build/C/man5/services.5:165
13499 "This file might be distributed over a network using a network-wide naming "
13500 "service like Yellow Pages/NIS or BIND/Hesiod."
13503 #. type: Plain text
13504 #: build/C/man5/protocols.5:81
13505 msgid "The protocols definition file."
13508 #. type: Plain text
13509 #: build/C/man5/protocols.5:83
13510 msgid "B<getprotoent>(3)"
13513 #. type: Plain text
13514 #: build/C/man5/protocols.5:85
13515 msgid "E<.UR http://www.iana.org\\:/assignments\\:/protocol-numbers> E<.UE>"
13519 #: build/C/man7/raw.7:13
13524 #. type: Plain text
13525 #: build/C/man7/raw.7:16
13526 msgid "raw - Linux IPv4 raw sockets"
13529 #. type: Plain text
13530 #: build/C/man7/raw.7:22
13531 msgid "B<raw_socket = socket(AF_INET, SOCK_RAW, int >I<protocol>B<);>"
13534 #. type: Plain text
13535 #: build/C/man7/raw.7:26
13537 "Raw sockets allow new IPv4 protocols to be implemented in user space. A raw "
13538 "socket receives or sends the raw datagram not including link level headers."
13541 #. type: Plain text
13542 #: build/C/man7/raw.7:32
13544 "The IPv4 layer generates an IP header when sending a packet unless the "
13545 "B<IP_HDRINCL> socket option is enabled on the socket. When it is enabled, "
13546 "the packet must contain an IP header. For receiving the IP header is always "
13547 "included in the packet."
13550 #. type: Plain text
13551 #: build/C/man7/raw.7:36
13553 "Only processes with an effective user ID of 0 or the B<CAP_NET_RAW> "
13554 "capability are allowed to open raw sockets."
13557 #. type: Plain text
13558 #: build/C/man7/raw.7:43
13560 "All packets or errors matching the I<protocol> number specified for the raw "
13561 "socket are passed to this socket. For a list of the allowed protocols see "
13562 "RFC\\ 1700 assigned numbers and B<getprotobyname>(3)."
13565 #. type: Plain text
13566 #: build/C/man7/raw.7:53
13568 "A protocol of B<IPPROTO_RAW> implies enabled B<IP_HDRINCL> and is able to "
13569 "send any IP protocol that is specified in the passed header. Receiving of "
13570 "all IP protocols via B<IPPROTO_RAW> is not possible using raw sockets."
13574 #: build/C/man7/raw.7:58
13576 msgid "IP Header fields modified on sending by B<IP_HDRINCL>\n"
13580 #: build/C/man7/raw.7:59
13582 msgid "IP Checksum:Always filled in.\n"
13586 #: build/C/man7/raw.7:60
13588 msgid "Source Address:Filled in when zero.\n"
13592 #: build/C/man7/raw.7:61
13594 msgid "Packet Id:Filled in when zero.\n"
13598 #: build/C/man7/raw.7:62
13600 msgid "Total Length:Always filled in.\n"
13603 #. type: Plain text
13604 #: build/C/man7/raw.7:76
13606 "If B<IP_HDRINCL> is specified and the IP header has a nonzero destination "
13607 "address, then the destination address of the socket is used to route the "
13608 "packet. When B<MSG_DONTROUTE> is specified, the destination address should "
13609 "refer to a local interface, otherwise a routing table lookup is done anyway "
13610 "but gatewayed routes are ignored."
13613 #. type: Plain text
13614 #: build/C/man7/raw.7:84
13616 "If B<IP_HDRINCL> isn't set, then IP header options can be set on raw sockets "
13617 "with B<setsockopt>(2); see B<ip>(7) for more information."
13620 #. type: Plain text
13621 #: build/C/man7/raw.7:89
13623 "In Linux 2.2, all IP header fields and options can be set using IP socket "
13624 "options. This means raw sockets are usually needed only for new protocols "
13625 "or protocols with no user interface (like ICMP)."
13628 #. type: Plain text
13629 #: build/C/man7/raw.7:93
13631 "When a packet is received, it is passed to any raw sockets which have been "
13632 "bound to its protocol before it is passed to other protocol handlers (e.g., "
13633 "kernel protocol modules)."
13636 #. type: Plain text
13637 #: build/C/man7/raw.7:109
13639 "Raw sockets use the standard I<sockaddr_in> address structure defined in "
13640 "B<ip>(7). The I<sin_port> field could be used to specify the IP protocol "
13641 "number, but it is ignored for sending in Linux 2.2 and should be always set "
13642 "to 0 (see BUGS). For incoming packets, I<sin_port> is set to the protocol "
13643 "of the packet. See the I<E<lt>netinet/in.hE<gt>> include file for valid IP "
13647 #. Or SOL_RAW on Linux
13648 #. type: Plain text
13649 #: build/C/man7/raw.7:118
13651 "Raw socket options can be set with B<setsockopt>(2) and read with "
13652 "B<getsockopt>(2) by passing the B<IPPROTO_RAW> family flag."
13656 #: build/C/man7/raw.7:118
13658 msgid "B<ICMP_FILTER>"
13661 #. type: Plain text
13662 #: build/C/man7/raw.7:126
13664 "Enable a special filter for raw sockets bound to the B<IPPROTO_ICMP> "
13665 "protocol. The value has a bit set for each ICMP message type which should "
13666 "be filtered out. The default is to filter no ICMP messages."
13669 #. type: Plain text
13670 #: build/C/man7/raw.7:131
13672 "In addition, all B<ip>(7) B<IPPROTO_IP> socket options valid for datagram "
13673 "sockets are supported."
13676 #. type: Plain text
13677 #: build/C/man7/raw.7:144
13679 "Errors originating from the network are passed to the user only when the "
13680 "socket is connected or the B<IP_RECVERR> flag is enabled. For connected "
13681 "sockets, only B<EMSGSIZE> and B<EPROTO> are passed for compatibility. With "
13682 "B<IP_RECVERR>, all network errors are saved in the error queue."
13685 #. type: Plain text
13686 #: build/C/man7/raw.7:149
13688 "User tried to send to a broadcast address without having the broadcast flag "
13689 "set on the socket."
13692 #. type: Plain text
13693 #: build/C/man7/raw.7:152
13694 msgid "An invalid memory address was supplied."
13697 #. type: Plain text
13698 #: build/C/man7/raw.7:162
13700 "Packet too big. Either Path MTU Discovery is enabled (the "
13701 "B<IP_MTU_DISCOVER> socket flag) or the packet size exceeds the maximum "
13702 "allowed IPv4 packet size of 64KB."
13706 #: build/C/man7/raw.7:162 build/C/man7/unix.7:447
13708 msgid "B<EOPNOTSUPP>"
13711 #. type: Plain text
13712 #: build/C/man7/raw.7:166
13713 msgid "Invalid flag has been passed to a socket call (like B<MSG_OOB>)."
13716 #. type: Plain text
13717 #: build/C/man7/raw.7:172
13719 "The user doesn't have permission to open raw sockets. Only processes with "
13720 "an effective user ID of 0 or the B<CAP_NET_RAW> attribute may do that."
13724 #: build/C/man7/raw.7:172
13729 #. type: Plain text
13730 #: build/C/man7/raw.7:175
13731 msgid "An ICMP error has arrived reporting a parameter problem."
13734 #. type: Plain text
13735 #: build/C/man7/raw.7:181
13737 "B<IP_RECVERR> and B<ICMP_FILTER> are new in Linux 2.2. They are Linux "
13738 "extensions and should not be used in portable programs."
13741 #. type: Plain text
13742 #: build/C/man7/raw.7:187
13744 "Linux 2.0 enabled some bug-to-bug compatibility with BSD in the raw socket "
13745 "code when the B<SO_BSDCOMPAT> socket option was set \\(em since Linux 2.2, "
13746 "this option no longer has that effect."
13749 #. type: Plain text
13750 #: build/C/man7/raw.7:205
13752 "By default, raw sockets do path MTU (Maximum Transmission Unit) discovery. "
13753 "This means the kernel will keep track of the MTU to a specific target IP "
13754 "address and return B<EMSGSIZE> when a raw packet write exceeds it. When "
13755 "this happens, the application should decrease the packet size. Path MTU "
13756 "discovery can be also turned off using the B<IP_MTU_DISCOVER> socket option "
13757 "or the I</proc/sys/net/ipv4/ip_no_pmtu_disc> file, see B<ip>(7) for "
13758 "details. When turned off, raw sockets will fragment outgoing packets that "
13759 "exceed the interface MTU. However, disabling it is not recommended for "
13760 "performance and reliability reasons."
13763 #. type: Plain text
13764 #: build/C/man7/raw.7:214
13766 "A raw socket can be bound to a specific local address using the B<bind>(2) "
13767 "call. If it isn't bound, all packets with the specified IP protocol are "
13768 "received. In addition, a RAW socket can be bound to a specific network "
13769 "device using B<SO_BINDTODEVICE>; see B<socket>(7)."
13772 #. type: Plain text
13773 #: build/C/man7/raw.7:225
13775 "An B<IPPROTO_RAW> socket is send only. If you really want to receive all IP "
13776 "packets, use a B<packet>(7) socket with the B<ETH_P_IP> protocol. Note "
13777 "that packet sockets don't reassemble IP fragments, unlike raw sockets."
13780 #. type: Plain text
13781 #: build/C/man7/raw.7:231
13783 "If you want to receive all ICMP packets for a datagram socket, it is often "
13784 "better to use B<IP_RECVERR> on that particular socket; see B<ip>(7)."
13787 #. type: Plain text
13788 #: build/C/man7/raw.7:238
13790 "Raw sockets may tap all IP protocols in Linux, even protocols like ICMP or "
13791 "TCP which have a protocol module in the kernel. In this case, the packets "
13792 "are passed to both the kernel module and the raw socket(s). This should not "
13793 "be relied upon in portable programs, many other BSD socket implementation "
13794 "have limitations here."
13797 #. type: Plain text
13798 #: build/C/man7/raw.7:243
13800 "Linux never changes headers passed from the user (except for filling in some "
13801 "zeroed fields as described for B<IP_HDRINCL>). This differs from many other "
13802 "implementations of raw sockets."
13805 #. type: Plain text
13806 #: build/C/man7/raw.7:246
13808 "RAW sockets are generally rather unportable and should be avoided in "
13809 "programs intended to be portable."
13812 #. type: Plain text
13813 #: build/C/man7/raw.7:252
13815 "Sending on raw sockets should take the IP protocol from I<sin_port>; this "
13816 "ability was lost in Linux 2.2. The workaround is to use B<IP_HDRINCL>."
13819 #. type: Plain text
13820 #: build/C/man7/raw.7:254
13821 msgid "Transparent proxy extensions are not described."
13824 #. type: Plain text
13825 #: build/C/man7/raw.7:259
13827 "When the B<IP_HDRINCL> option is set, datagrams will not be fragmented and "
13828 "are limited to the interface MTU."
13832 #. This man page was written by Andi Kleen.
13833 #. type: Plain text
13834 #: build/C/man7/raw.7:269
13836 "Setting the IP protocol for sending in I<sin_port> got lost in Linux 2.2. "
13837 "The protocol that the socket was bound to or that was specified in the "
13838 "initial B<socket>(2) call is always used."
13841 #. type: Plain text
13842 #: build/C/man7/raw.7:275
13843 msgid "B<recvmsg>(2), B<sendmsg>(2), B<capabilities>(7), B<ip>(7), B<socket>(7)"
13846 #. type: Plain text
13847 #: build/C/man7/raw.7:281
13849 "B<RFC\\ 1191> for path MTU discovery. B<RFC\\ 791> and the "
13850 "I<E<lt>linux/ip.hE<gt>> header file for the IP protocol."
13854 #: build/C/man3/rcmd.3:43
13859 #. type: Plain text
13860 #: build/C/man3/rcmd.3:48
13862 "rcmd, rresvport, iruserok, ruserok, rcmd_af, rresvport_af, iruserok_af, "
13863 "ruserok_af - routines for returning a stream to a remote command"
13866 #. type: Plain text
13867 #: build/C/man3/rcmd.3:51
13870 "B<#include E<lt>netdb.hE<gt> \\ \\ >/* Or E<lt>unistd.hE<gt> on some systems "
13874 #. type: Plain text
13875 #: build/C/man3/rcmd.3:54
13878 "B<int rcmd(char **>I<ahost>B<, unsigned short >I<inport>B<, const char "
13879 "*>I<locuser>B<, >\n"
13880 "B< const char *>I<remuser>B<, const char *>I<cmd>B<, int "
13884 #. type: Plain text
13885 #: build/C/man3/rcmd.3:56
13887 msgid "B<int rresvport(int *>I<port>B<);>\n"
13890 #. type: Plain text
13891 #: build/C/man3/rcmd.3:59
13894 "B<int iruserok(uint32_t >I<raddr>B<, int >I<superuser>B<, >\n"
13895 "B< const char *>I<ruser>B<, const char *>I<luser>B<);>\n"
13898 #. type: Plain text
13899 #: build/C/man3/rcmd.3:62
13902 "B<int ruserok(const char *>I<rhost>B<, int >I<superuser>B<, >\n"
13903 "B< const char *>I<ruser>B<, const char *>I<luser>B<);>\n"
13906 #. type: Plain text
13907 #: build/C/man3/rcmd.3:66
13910 "B<int rcmd_af(char **>I<ahost>B<, unsigned short >I<inport>B<, const char "
13911 "*>I<locuser>B<, >\n"
13912 "B< const char *>I<remuser>B<, const char *>I<cmd>B<, int "
13914 "B< sa_family_t >I<af>B<);>\n"
13917 #. type: Plain text
13918 #: build/C/man3/rcmd.3:68
13920 msgid "B<int rresvport_af(int *>I<port>B<, sa_family_t >I<af>B<);>\n"
13923 #. type: Plain text
13924 #: build/C/man3/rcmd.3:72
13927 "B<int iruserok_af(const void *>I<raddr>B<, int >I<superuser>B<, >\n"
13928 "B< const char *>I<ruser>B<, const char *>I<luser>B<, "
13929 "sa_family_t >I<af>B<);>\n"
13932 #. type: Plain text
13933 #: build/C/man3/rcmd.3:76
13936 "B<int ruserok_af(const char *>I<rhost>B<, int >I<superuser>B<, >\n"
13937 "B< const char *>I<ruser>B<, const char *>I<luser>B<, "
13938 "sa_family_t >I<af>B<);>\n"
13941 #. type: Plain text
13942 #: build/C/man3/rcmd.3:92
13944 "B<rcmd>(), B<rcmd_af>(), B<rresvport>(), B<rresvport_af>(), B<iruserok>(), "
13945 "B<iruserok_af>(), B<ruserok>(), B<ruserok_af>(): _BSD_SOURCE"
13948 #. type: Plain text
13949 #: build/C/man3/rcmd.3:113
13951 "The B<rcmd>() function is used by the superuser to execute a command on a "
13952 "remote machine using an authentication scheme based on privileged port "
13953 "numbers. The B<rresvport>() function returns a descriptor to a socket with "
13954 "an address in the privileged port space. The B<iruserok>() and "
13955 "B<ruserok>() functions are used by servers to authenticate clients "
13956 "requesting service with B<rcmd>(). All four functions are used by the "
13957 "B<rshd>(8) server (among others)."
13961 #: build/C/man3/rcmd.3:113
13966 #. type: Plain text
13967 #: build/C/man3/rcmd.3:129
13969 "The B<rcmd>() function looks up the host I<*ahost> using "
13970 "B<gethostbyname>(3), returning -1 if the host does not exist. Otherwise, "
13971 "I<*ahost> is set to the standard name of the host and a connection is "
13972 "established to a server residing at the well-known Internet port I<inport>."
13975 #. type: Plain text
13976 #: build/C/man3/rcmd.3:158
13978 "If the connection succeeds, a socket in the Internet domain of type "
13979 "B<SOCK_STREAM> is returned to the caller, and given to the remote command as "
13980 "I<stdin> and I<stdout>. If I<fd2p> is nonzero, then an auxiliary channel to "
13981 "a control process will be set up, and a descriptor for it will be placed in "
13982 "I<*fd2p>. The control process will return diagnostic output from the "
13983 "command (unit 2) on this channel, and will also accept bytes on this channel "
13984 "as being UNIX signal numbers, to be forwarded to the process group of the "
13985 "command. If I<fd2p> is 0, then the I<stderr> (unit 2 of the remote command) "
13986 "will be made the same as the I<stdout> and no provision is made for sending "
13987 "arbitrary signals to the remote process, although you may be able to get its "
13988 "attention by using out-of-band data."
13991 #. type: Plain text
13992 #: build/C/man3/rcmd.3:161
13993 msgid "The protocol is described in detail in B<rshd>(8)."
13997 #: build/C/man3/rcmd.3:161
13999 msgid "rresvport()"
14002 #. type: Plain text
14003 #: build/C/man3/rcmd.3:183
14005 "The B<rresvport>() function is used to obtain a socket with a privileged "
14006 "port bound to it. This socket is suitable for use by B<rcmd>() and several "
14007 "other functions. Privileged ports are those in the range 0 to 1023. Only a "
14008 "privileged process (B<CAP_NET_BIND_SERVICE>) is allowed to bind to a "
14009 "privileged port. In the glibc implementation, this function restricts its "
14010 "search to the ports from 512 to 1023. The I<port> argument is value-result: "
14011 "the value it supplies to the call is used as the starting point for a "
14012 "circular search of the port range; on (successful) return, it contains the "
14013 "port number that was bound to."
14017 #: build/C/man3/rcmd.3:183
14019 msgid "iruserok() and ruserok()"
14022 #. type: Plain text
14023 #: build/C/man3/rcmd.3:201
14025 "The B<iruserok>() and B<ruserok>() functions take a remote host's IP "
14026 "address or name, respectively, two usernames and a flag indicating whether "
14027 "the local user's name is that of the superuser. Then, if the user is I<not> "
14028 "the superuser, it checks the I</etc/hosts.equiv> file. If that lookup is "
14029 "not done, or is unsuccessful, the I<.rhosts> in the local user's home "
14030 "directory is checked to see if the request for service is allowed."
14033 #. type: Plain text
14034 #: build/C/man3/rcmd.3:217
14036 "If this file does not exist, is not a regular file, is owned by anyone other "
14037 "than the user or the superuser, or is writable by anyone other than the "
14038 "owner, the check automatically fails. Zero is returned if the machine name "
14039 "is listed in the I<hosts.equiv> file, or the host and remote username are "
14040 "found in the I<.rhosts> file; otherwise B<iruserok>() and B<ruserok>() "
14041 "return -1. If the local domain (as obtained from B<gethostname>(2)) is the "
14042 "same as the remote domain, only the machine name need be specified."
14045 #. type: Plain text
14046 #: build/C/man3/rcmd.3:223
14048 "If the IP address of the remote host is known, B<iruserok>() should be used "
14049 "in preference to B<ruserok>(), as it does not require trusting the DNS "
14050 "server for the remote host's domain."
14054 #: build/C/man3/rcmd.3:223
14056 msgid "*_af() variants"
14059 #. type: Plain text
14060 #: build/C/man3/rcmd.3:239
14062 "All of the functions described above work with IPv4 (B<AF_INET>) sockets. "
14063 "The \"_af\" variants take an extra argument that allows the socket address "
14064 "family to be specified. For these functions, the I<af> argument can be "
14065 "specified as B<AF_INET> or B<AF_INET6>. In addition, B<rcmd_af>() supports "
14066 "the use of B<AF_UNSPEC>."
14069 #. type: Plain text
14070 #: build/C/man3/rcmd.3:245
14072 "The B<rcmd>() function returns a valid socket descriptor on success. It "
14073 "returns -1 on error and prints a diagnostic message on the standard error."
14076 #. type: Plain text
14077 #: build/C/man3/rcmd.3:256
14079 "The B<rresvport>() function returns a valid, bound socket descriptor on "
14080 "success. It returns -1 on error with the global value I<errno> set "
14081 "according to the reason for failure. The error code B<EAGAIN> is overloaded "
14082 "to mean \"All network ports in use.\""
14085 #. type: Plain text
14086 #: build/C/man3/rcmd.3:262
14088 "For information on the return from B<ruserok>() and B<iruserok>(), see "
14092 #. type: Plain text
14093 #: build/C/man3/rcmd.3:270
14095 "The functions B<iruserok_af>(), B<rcmd_af>(), B<rresvport_af>(), and "
14096 "B<ruserok_af>() functions are provide in glibc since version 2.2."
14099 #. type: Plain text
14100 #: build/C/man3/rcmd.3:278
14102 "Not in POSIX.1-2001. Present on the BSDs, Solaris, and many other systems. "
14103 "These functions appeared in 4.2BSD. The \"_af\" variants are more recent "
14104 "additions, and are not present on as wide a range of systems."
14107 #. Bug filed 25 Nov 2007:
14108 #. http://sources.redhat.com/bugzilla/show_bug.cgi?id=5399
14109 #. type: Plain text
14110 #: build/C/man3/rcmd.3:285
14112 "B<iruserok>() and B<iruserok_af>() are declared in glibc headers only "
14113 "since version 2.12."
14116 #. type: Plain text
14117 #: build/C/man3/rcmd.3:292
14119 "B<rlogin>(1), B<rsh>(1), B<intro>(2), B<rexec>(3), B<rexecd>(8), "
14120 "B<rlogind>(8), B<rshd>(8)"
14124 #: build/C/man5/resolv.conf.5:23
14126 msgid "RESOLV.CONF"
14129 #. type: Plain text
14130 #: build/C/man5/resolv.conf.5:27
14131 msgid "resolv.conf - resolver configuration file"
14134 #. type: Plain text
14135 #: build/C/man5/resolv.conf.5:29
14136 msgid "B</etc/resolv.conf>"
14139 #. type: Plain text
14140 #: build/C/man5/resolv.conf.5:41
14142 "The I<resolver> is a set of routines in the C library that provide access to "
14143 "the Internet Domain Name System (DNS). The resolver configuration file "
14144 "contains information that is read by the resolver routines the first time "
14145 "they are invoked by a process. The file is designed to be human readable "
14146 "and contains a list of keywords with values that provide various types of "
14147 "resolver information. The configuration file is considered a trusted source "
14148 "of DNS information (e.g., DNSSEC AD-bit information will be returned "
14149 "unmodified from this source)."
14152 #. type: Plain text
14153 #: build/C/man5/resolv.conf.5:46
14155 "If this file does not exist, only the name server on the local machine will "
14156 "be queried; the domain name is determined from the hostname and the domain "
14157 "search path is constructed from the domain name."
14160 #. type: Plain text
14161 #: build/C/man5/resolv.conf.5:48
14162 msgid "The different configuration options are:"
14166 #: build/C/man5/resolv.conf.5:48
14168 msgid "B<nameserver> Name server IP address"
14171 #. type: Plain text
14172 #: build/C/man5/resolv.conf.5:65
14174 "Internet address of a name server that the resolver should query, either an "
14175 "IPv4 address (in dot notation), or an IPv6 address in colon (and possibly "
14176 "dot) notation as per RFC 2373. Up to B<MAXNS> (currently 3, see "
14177 "I<E<lt>resolv.hE<gt>>) name servers may be listed, one per keyword. If "
14178 "there are multiple servers, the resolver library queries them in the order "
14179 "listed. If no B<nameserver> entries are present, the default is to use the "
14180 "name server on the local machine. (The algorithm used is to try a name "
14181 "server, and if the query times out, try the next, until out of name servers, "
14182 "then repeat trying all the name servers until a maximum number of retries "
14187 #: build/C/man5/resolv.conf.5:65
14189 msgid "B<domain> Local domain name."
14192 #. type: Plain text
14193 #: build/C/man5/resolv.conf.5:76
14195 "Most queries for names within this domain can use short names relative to "
14196 "the local domain. If set to \\(aq.\\(aq, the root domain is considered. If "
14197 "no B<domain> entry is present, the domain is determined from the local "
14198 "hostname returned by B<gethostname>(2); the domain part is taken to be "
14199 "everything after the first \\(aq.\\(aq. Finally, if the hostname does not "
14200 "contain a domain part, the root domain is assumed."
14204 #: build/C/man5/resolv.conf.5:76
14206 msgid "B<search> Search list for host-name lookup."
14209 #. When having a resolv.conv with a line
14210 #. search subdomain.domain.tld domain.tld
14211 #. and doing a hostlookup, for example by
14212 #. ping host.anothersubdomain
14213 #. it sends dns-requests for
14214 #. host.anothersubdomain.
14215 #. host.anothersubdomain.subdomain.domain.tld.
14216 #. host.anothersubdomain.domain.tld.
14217 #. thus not only causing unnecessary traffic for the root-dns-servers
14218 #. but broadcasting information to the outside and making man-in-the-middle
14219 #. attacks possible.
14220 #. type: Plain text
14221 #: build/C/man5/resolv.conf.5:106
14223 "The search list is normally determined from the local domain name; by "
14224 "default, it contains only the local domain name. This may be changed by "
14225 "listing the desired domain search path following the I<search> keyword with "
14226 "spaces or tabs separating the names. Resolver queries having fewer than "
14227 "I<ndots> dots (default is 1) in them will be attempted using each component "
14228 "of the search path in turn until a match is found. For environments with "
14229 "multiple subdomains please read B<options ndots:>I<n> below to avoid "
14230 "man-in-the-middle attacks and unnecessary traffic for the root-dns-servers. "
14231 "Note that this process may be slow and will generate a lot of network "
14232 "traffic if the servers for the listed domains are not local, and that "
14233 "queries will time out if no server is available for one of the domains."
14236 #. type: Plain text
14237 #: build/C/man5/resolv.conf.5:109
14239 "The search list is currently limited to six domains with a total of 256 "
14244 #: build/C/man5/resolv.conf.5:109
14246 msgid "B<sortlist>"
14249 #. type: Plain text
14250 #: build/C/man5/resolv.conf.5:122
14252 "This option allows addresses returned by B<gethostbyname>(3) to be sorted. "
14253 "A sortlist is specified by IP-address-netmask pairs. The netmask is "
14254 "optional and defaults to the natural netmask of the net. The IP address and "
14255 "optional network pairs are separated by slashes. Up to 10 pairs may be "
14256 "specified. Here is an example:"
14259 #. type: Plain text
14260 #: build/C/man5/resolv.conf.5:125
14261 msgid "sortlist 130.155.160.0/255.255.240.0 130.155.0.0"
14265 #: build/C/man5/resolv.conf.5:127
14270 #. type: Plain text
14271 #: build/C/man5/resolv.conf.5:131
14273 "Options allows certain internal resolver variables to be modified. The "
14277 #. type: Plain text
14278 #: build/C/man5/resolv.conf.5:134
14279 msgid "B<options> I<option> I<...>"
14282 #. type: Plain text
14283 #: build/C/man5/resolv.conf.5:136
14284 msgid "where I<option> is one of the following:"
14288 #: build/C/man5/resolv.conf.5:136
14293 #. Since glibc 2.2?
14294 #. type: Plain text
14295 #: build/C/man5/resolv.conf.5:145
14297 "sets B<RES_DEBUG> in I<_res.options> (effective only if glibc was built with "
14298 "debug support; see B<resolver>(3))."
14302 #: build/C/man5/resolv.conf.5:145
14304 msgid "B<ndots:>I<n>"
14308 #. type: Plain text
14309 #: build/C/man5/resolv.conf.5:159
14311 "sets a threshold for the number of dots which must appear in a name given to "
14312 "B<res_query>(3) (see B<resolver>(3)) before an I<initial absolute query> "
14313 "will be made. The default for I<n> is 1, meaning that if there are any dots "
14314 "in a name, the name will be tried first as an absolute name before any "
14315 "I<search list> elements are appended to it. The value for this option is "
14316 "silently capped to 15."
14320 #: build/C/man5/resolv.conf.5:159
14322 msgid "B<timeout:>I<n>"
14326 #. type: Plain text
14327 #: build/C/man5/resolv.conf.5:170
14329 "sets the amount of time the resolver will wait for a response from a remote "
14330 "name server before retrying the query via a different name server. Measured "
14331 "in seconds, the default is B<RES_TIMEOUT> (currently 5, see "
14332 "I<E<lt>resolv.hE<gt>>). The value for this option is silently capped to 30."
14336 #: build/C/man5/resolv.conf.5:170
14338 msgid "B<attempts:>I<n>"
14341 #. type: Plain text
14342 #: build/C/man5/resolv.conf.5:179
14344 "sets the number of times the resolver will send a query to its name servers "
14345 "before giving up and returning an error to the calling application. The "
14346 "default is B<RES_DFLRETRY> (currently 2, see I<E<lt>resolv.hE<gt>>). The "
14347 "value for this option is silently capped to 5."
14351 #: build/C/man5/resolv.conf.5:179
14357 #. type: Plain text
14358 #: build/C/man5/resolv.conf.5:189
14360 "sets B<RES_ROTATE> in I<_res.options>, which causes round-robin selection of "
14361 "name servers from among those listed. This has the effect of spreading the "
14362 "query load among all listed servers, rather than having all clients try the "
14363 "first listed server first every time."
14367 #: build/C/man5/resolv.conf.5:189
14369 msgid "B<no-check-names>"
14373 #. type: Plain text
14374 #: build/C/man5/resolv.conf.5:199
14376 "sets B<RES_NOCHECKNAME> in I<_res.options>, which disables the modern BIND "
14377 "checking of incoming hostnames and mail names for invalid characters such as "
14378 "underscore (_), non-ASCII, or control characters."
14382 #: build/C/man5/resolv.conf.5:199
14388 #. type: Plain text
14389 #: build/C/man5/resolv.conf.5:210
14391 "sets B<RES_USE_INET6> in I<_res.options>. This has the effect of trying a "
14392 "AAAA query before an A query inside the B<gethostbyname>(3) function, and "
14393 "of mapping IPv4 responses in IPv6 \"tunneled form\" if no AAAA records are "
14394 "found but an A record set exists."
14398 #: build/C/man5/resolv.conf.5:210
14400 msgid "B<ip6-bytestring> (since glibc 2.3.4)"
14403 #. type: Plain text
14404 #: build/C/man5/resolv.conf.5:219
14406 "sets B<RES_USE_BSTRING> in I<_res.options>. This causes reverse IPv6 "
14407 "lookups to be made using the bit-label format described in RFC\\ 2673; if "
14408 "this option is not set, then nibble format is used."
14412 #: build/C/man5/resolv.conf.5:219
14414 msgid "B<ip6-dotint>/B<no-ip6-dotint> (since glibc 2.3.4)"
14417 #. type: Plain text
14418 #: build/C/man5/resolv.conf.5:236
14420 "Clear/set B<RES_NOIP6DOTINT> in I<_res.options>. When this option is clear "
14421 "(B<ip6-dotint>), reverse IPv6 lookups are made in the (deprecated) "
14422 "I<ip6.int> zone; when this option is set (B<no-ip6-dotint>), reverse IPv6 "
14423 "lookups are made in the I<ip6.arpa> zone by default. This option is set by "
14428 #: build/C/man5/resolv.conf.5:236
14430 msgid "B<edns0> (since glibc 2.6)"
14433 #. type: Plain text
14434 #: build/C/man5/resolv.conf.5:243
14436 "sets B<RES_USE_EDNSO> in I<_res.options>. This enables support for the DNS "
14437 "extensions described in RFC\\ 2671."
14441 #: build/C/man5/resolv.conf.5:243
14443 msgid "B<single-request> (since glibc 2.10)"
14446 #. type: Plain text
14447 #: build/C/man5/resolv.conf.5:256
14449 "sets B<RES_SNGLKUP> in I<_res.options>. By default, glibc performs IPv4 and "
14450 "IPv6 lookups in parallel since version 2.9. Some appliance DNS servers "
14451 "cannot handle these queries properly and make the requests time out. This "
14452 "option disables the behavior and makes glibc perform the IPv6 and IPv4 "
14453 "requests sequentially (at the cost of some slowdown of the resolving "
14458 #: build/C/man5/resolv.conf.5:256
14460 msgid "B<single-request-reopen> (since glibc 2.9)"
14463 #. type: Plain text
14464 #: build/C/man5/resolv.conf.5:264
14466 "The resolver uses the same socket for the A and AAAA requests. Some "
14467 "hardware mistakenly sends back only one reply. When that happens the client "
14468 "system will sit and wait for the second reply. Turning this option on "
14469 "changes this behavior so that if two requests from the same port are not "
14470 "handled correctly it will close the socket and open a new one before sending "
14471 "the second request."
14475 #: build/C/man5/resolv.conf.5:264
14477 msgid "B<no-tld-query> (since glibc 2.14)"
14480 #. type: Plain text
14481 #: build/C/man5/resolv.conf.5:275
14483 "sets RES_NOTLDQUERY in I<_res.options>. This option causes B<res_nsearch>() "
14484 "to not attempt to resolve an unqualified name as if it were a top level "
14485 "domain (TLD). This option can cause problems if the site has ``localhost'' "
14486 "as a TLD rather than having localhost on one or more elements of the search "
14487 "list. This option has no effect if neither RES_DEFNAMES or RES_DNSRCH is "
14491 #. type: Plain text
14492 #: build/C/man5/resolv.conf.5:280
14494 "The I<domain> and I<search> keywords are mutually exclusive. If more than "
14495 "one instance of these keywords is present, the last instance wins."
14498 #. type: Plain text
14499 #: build/C/man5/resolv.conf.5:285
14501 "The I<search> keyword of a system's I<resolv.conf> file can be overridden on "
14502 "a per-process basis by setting the environment variable B<LOCALDOMAIN> to a "
14503 "space-separated list of search domains."
14506 #. type: Plain text
14507 #: build/C/man5/resolv.conf.5:291
14509 "The I<options> keyword of a system's I<resolv.conf> file can be amended on a "
14510 "per-process basis by setting the environment variable B<RES_OPTIONS> to a "
14511 "space-separated list of resolver options as explained above under "
14515 #. type: Plain text
14516 #: build/C/man5/resolv.conf.5:295
14518 "The keyword and value must appear on a single line, and the keyword (e.g., "
14519 "B<nameserver>) must start the line. The value follows the keyword, "
14520 "separated by white space."
14523 #. type: Plain text
14524 #: build/C/man5/resolv.conf.5:298
14526 "Lines that contain a semicolon (;) or hash character (#) in the first "
14527 "column are treated as comments."
14530 #. type: Plain text
14531 #: build/C/man5/resolv.conf.5:301
14532 msgid "I</etc/resolv.conf>, I<E<lt>resolv.hE<gt>>"
14535 #. type: Plain text
14536 #: build/C/man5/resolv.conf.5:306
14537 msgid "B<gethostbyname>(3), B<resolver>(3), B<hostname>(7), B<named>(8)"
14540 #. type: Plain text
14541 #: build/C/man5/resolv.conf.5:307
14542 msgid "Name Server Operations Guide for BIND"
14546 #: build/C/man3/resolver.3:32
14551 #. type: Plain text
14552 #: build/C/man3/resolver.3:36
14554 "res_init, res_query, res_search, res_querydomain, res_mkquery, res_send, "
14555 "dn_comp, dn_expand - resolver routines"
14558 #. type: Plain text
14559 #: build/C/man3/resolver.3:42
14562 "B<#include E<lt>netinet/in.hE<gt>>\n"
14563 "B<#include E<lt>arpa/nameser.hE<gt>>\n"
14564 "B<#include E<lt>resolv.hE<gt>>\n"
14565 "B<extern struct __res_state _res;>\n"
14568 #. type: Plain text
14569 #: build/C/man3/resolver.3:44
14571 msgid "B<int res_init(void);>\n"
14574 #. type: Plain text
14575 #: build/C/man3/resolver.3:46
14577 msgid "B<int res_query(const char *>I<dname>B<, int >I<class>B<, int >I<type>B<,>\n"
14580 #. type: Plain text
14581 #: build/C/man3/resolver.3:48 build/C/man3/resolver.3:53 build/C/man3/resolver.3:70
14583 msgid "B<unsigned char *>I<answer>B<, int >I<anslen>B<);>\n"
14586 #. type: Plain text
14587 #: build/C/man3/resolver.3:51
14590 "B<int res_search(const char *>I<dname>B<, int >I<class>B<, int "
14594 #. type: Plain text
14595 #: build/C/man3/resolver.3:56
14597 msgid "B<int res_querydomain(const char *>I<name>B<, const char *>I<domain>B<,>\n"
14600 #. type: Plain text
14601 #: build/C/man3/resolver.3:59
14604 "B<int >I<class>B<, int >I<type>B<, unsigned char *>I<answer>B<,>\n"
14605 "B<int >I<anslen>B<);>\n"
14608 #. type: Plain text
14609 #: build/C/man3/resolver.3:62
14611 msgid "B<int res_mkquery(int >I<op>B<, const char *>I<dname>B<, int >I<class>B<,>\n"
14614 #. type: Plain text
14615 #: build/C/man3/resolver.3:65
14618 "B<int >I<type>B<, const unsigned char *>I<data>B<, int >I<datalen>B<,>\n"
14619 "B<const unsigned char *>I<newrr>B<, unsigned char *>I<buf>B<, int "
14620 ">I<buflen>B<);>\n"
14623 #. type: Plain text
14624 #: build/C/man3/resolver.3:68
14626 msgid "B<int res_send(const unsigned char *>I<msg>B<, int >I<msglen>B<,>\n"
14629 #. type: Plain text
14630 #: build/C/man3/resolver.3:73
14632 msgid "B<int dn_comp(const char *>I<exp_dn>B<, unsigned char *>I<comp_dn>B<,>\n"
14635 #. type: Plain text
14636 #: build/C/man3/resolver.3:75
14639 "B<int >I<length>B<, unsigned char **>I<dnptrs>B<, unsigned char "
14640 "**>I<lastdnptr>B<);>\n"
14643 #. type: Plain text
14644 #: build/C/man3/resolver.3:78
14647 "B<int dn_expand(const unsigned char *>I<msg>B<, const unsigned char "
14648 "*>I<eomorig>B<,>\n"
14651 #. type: Plain text
14652 #: build/C/man3/resolver.3:81
14655 "B<const unsigned char *>I<comp_dn>B<, char *>I<exp_dn>B<,>\n"
14656 "B<int >I<length>B<);>\n"
14659 #. type: Plain text
14660 #: build/C/man3/resolver.3:88
14662 "These functions make queries to and interpret the responses from Internet "
14663 "domain name servers."
14666 #. type: Plain text
14667 #: build/C/man3/resolver.3:102
14669 "The B<res_init>() function reads the configuration files (see "
14670 "B<resolv.conf>(5)) to get the default domain name, search order and name "
14671 "server address(es). If no server is given, the local host is tried. If no "
14672 "domain is given, that associated with the local host is used. It can be "
14673 "overridden with the environment variable B<LOCALDOMAIN>. B<res_init>() is "
14674 "normally executed by the first call to one of the other functions."
14677 #. type: Plain text
14678 #: build/C/man3/resolver.3:110
14680 "The B<res_query>() function queries the name server for the fully qualified "
14681 "domain name I<name> of specified I<type> and I<class>. The reply is left in "
14682 "the buffer I<answer> of length I<anslen> supplied by the caller."
14685 #. type: Plain text
14686 #: build/C/man3/resolver.3:123
14688 "The B<res_search>() function makes a query and waits for the response like "
14689 "B<res_query>(), but in addition implements the default and search rules "
14690 "controlled by B<RES_DEFNAMES> and B<RES_DNSRCH> (see description of I<_res> "
14694 #. type: Plain text
14695 #: build/C/man3/resolver.3:129
14697 "The B<res_querydomain>() function makes a query using B<res_query>() on "
14698 "the concatenation of I<name> and I<domain>."
14701 #. type: Plain text
14702 #: build/C/man3/resolver.3:132
14703 msgid "The following functions are lower-level routines used by B<res_query>()."
14706 #. type: Plain text
14707 #: build/C/man3/resolver.3:143
14709 "The B<res_mkquery>() function constructs a query message in I<buf> of "
14710 "length I<buflen> for the domain name I<dname>. The query type I<op> is "
14711 "usually B<QUERY>, but can be any of the types defined in "
14712 "I<E<lt>arpa/nameser.hE<gt>>. I<newrr> is currently unused."
14715 #. type: Plain text
14716 #: build/C/man3/resolver.3:153
14718 "The B<res_send>() function sends a preformatted query given in I<msg> of "
14719 "length I<msglen> and returns the answer in I<answer> which is of length "
14720 "I<anslen>. It will call B<res_init>(), if it has not already been called."
14723 #. type: Plain text
14724 #: build/C/man3/resolver.3:166
14726 "The B<dn_comp>() function compresses the domain name I<exp_dn> and stores "
14727 "it in the buffer I<comp_dn> of length I<length>. The compression uses an "
14728 "array of pointers I<dnptrs> to previously compressed names in the current "
14729 "message. The first pointer points to the beginning of the message and the "
14730 "list ends with NULL. The limit of the array is specified by I<lastdnptr>. "
14731 "If I<dnptr> is NULL, domain names are not compressed. If I<lastdnptr> is "
14732 "NULL, the list of labels is not updated."
14735 #. type: Plain text
14736 #: build/C/man3/resolver.3:175
14738 "The B<dn_expand>() function expands the compressed domain name I<comp_dn> "
14739 "to a full domain name, which is placed in the buffer I<exp_dn> of size "
14740 "I<length>. The compressed name is contained in a query or reply message, "
14741 "and I<msg> points to the beginning of the message."
14744 #. type: Plain text
14745 #: build/C/man3/resolver.3:183
14747 "The resolver routines use global configuration and state information "
14748 "contained in the structure I<_res>, which is defined in "
14749 "I<E<lt>resolv.hE<gt>>. The only field that is normally manipulated by the "
14750 "user is I<_res.options>. This field can contain the bitwise \"OR\" of the "
14751 "following options:"
14755 #: build/C/man3/resolver.3:183
14757 msgid "B<RES_INIT>"
14760 #. type: Plain text
14761 #: build/C/man3/resolver.3:188
14762 msgid "True if B<res_init>() has been called."
14766 #: build/C/man3/resolver.3:188
14768 msgid "B<RES_DEBUG>"
14771 #. See resolv/README.
14772 #. Support for RES_DEBUG was made conditional in glibc 2.2.
14773 #. type: Plain text
14774 #: build/C/man3/resolver.3:195
14776 "Print debugging messages. This option is available only if glibc was built "
14777 "with debugging enabled, which is not the default."
14781 #: build/C/man3/resolver.3:195
14783 msgid "B<RES_AAONLY>"
14786 #. type: Plain text
14787 #: build/C/man3/resolver.3:202
14789 "Accept authoritative answers only. B<res_send>() continues until it finds "
14790 "an authoritative answer or returns an error. [Not currently implemented]."
14794 #: build/C/man3/resolver.3:202
14796 msgid "B<RES_USEVC>"
14799 #. type: Plain text
14800 #: build/C/man3/resolver.3:205
14801 msgid "Use TCP connections for queries rather than UDP datagrams."
14805 #: build/C/man3/resolver.3:205
14807 msgid "B<RES_PRIMARY>"
14810 #. type: Plain text
14811 #: build/C/man3/resolver.3:208
14812 msgid "Query primary domain name server only."
14816 #: build/C/man3/resolver.3:208
14818 msgid "B<RES_IGNTC>"
14821 #. type: Plain text
14822 #: build/C/man3/resolver.3:213
14824 "Ignore truncation errors. Don't retry with TCP. [Not currently "
14829 #: build/C/man3/resolver.3:213
14831 msgid "B<RES_RECURSE>"
14834 #. type: Plain text
14835 #: build/C/man3/resolver.3:220
14837 "Set the recursion desired bit in queries. Recursion is carried out by the "
14838 "domain name server, not by B<res_send>(). [Enabled by default]."
14842 #: build/C/man3/resolver.3:220
14844 msgid "B<RES_DEFNAMES>"
14847 #. type: Plain text
14848 #: build/C/man3/resolver.3:227
14850 "If set, B<res_search>() will append the default domain name to single "
14851 "component names\\(emthat is, those that do not contain a dot. [Enabled by "
14856 #: build/C/man3/resolver.3:227
14858 msgid "B<RES_STAYOPEN>"
14861 #. type: Plain text
14862 #: build/C/man3/resolver.3:232
14863 msgid "Used with B<RES_USEVC> to keep the TCP connection open between queries."
14867 #: build/C/man3/resolver.3:232
14869 msgid "B<RES_DNSRCH>"
14872 #. type: Plain text
14873 #: build/C/man3/resolver.3:241
14875 "If set, B<res_search>() will search for hostnames in the current domain and "
14876 "in parent domains. This option is used by B<gethostbyname>(3). [Enabled by "
14880 #. type: Plain text
14881 #: build/C/man3/resolver.3:245
14883 "This list is not complete. You can find some other flags described in "
14884 "B<resolv.conf>(5)."
14887 #. type: Plain text
14888 #: build/C/man3/resolver.3:250
14889 msgid "The B<res_init>() function returns 0 on success, or -1 if an error occurs."
14892 #. type: Plain text
14893 #: build/C/man3/resolver.3:260
14895 "The B<res_query>(), B<res_search>(), B<res_querydomain>(), B<res_mkquery>() "
14896 "and B<res_send>() functions return the length of the response, or -1 if an "
14900 #. type: Plain text
14901 #: build/C/man3/resolver.3:267
14903 "The B<dn_comp>() and B<dn_expand>() functions return the length of the "
14904 "compressed name, or -1 if an error occurs."
14907 #. type: Plain text
14908 #: build/C/man3/resolver.3:271
14911 "/etc/resolv.conf resolver configuration file\n"
14912 "/etc/host.conf resolver configuration file\n"
14915 #. type: Plain text
14916 #: build/C/man3/resolver.3:274
14920 #. type: Plain text
14921 #: build/C/man3/resolver.3:279
14923 "B<gethostbyname>(3), B<resolv.conf>(5), B<resolver>(5), B<hostname>(7), "
14928 #: build/C/man3/rexec.3:41
14933 #. type: Plain text
14934 #: build/C/man3/rexec.3:44
14935 msgid "rexec, rexec_af - return stream to a remote command"
14938 #. type: Plain text
14939 #: build/C/man3/rexec.3:48
14942 "B<#define _BSD_SOURCE> /* See feature_test_macros(7) */\n"
14943 "B<#include E<lt>netdb.hE<gt>>\n"
14946 #. type: Plain text
14947 #: build/C/man3/rexec.3:51
14950 "B<int rexec(char **>I<ahost>B<, int >I<inport>B<, const char *>I<user>B<, "
14952 "B< const char *>I<passwd>B<, const char *>I<cmd>B<, int "
14956 #. type: Plain text
14957 #: build/C/man3/rexec.3:55
14960 "B<int rexec_af(char **>I<ahost>B<, int >I<inport>B<, const char *>I<user>B<, "
14962 "B< const char *>I<passwd>B<, const char *>I<cmd>B<, int "
14964 "B< sa_family_t >I<af>B<);>\n"
14967 #. type: Plain text
14968 #: build/C/man3/rexec.3:59
14969 msgid "This interface is obsoleted by B<rcmd>(3)."
14972 #. type: Plain text
14973 #: build/C/man3/rexec.3:78
14975 "The B<rexec>() function looks up the host I<*ahost> using "
14976 "B<gethostbyname>(3), returning -1 if the host does not exist. Otherwise, "
14977 "I<*ahost> is set to the standard name of the host. If a username and "
14978 "password are both specified, then these are used to authenticate to the "
14979 "foreign host; otherwise the environment and then the I<.netrc> file in "
14980 "user's home directory are searched for appropriate information. If all this "
14981 "fails, the user is prompted for the information."
14984 #. type: Plain text
14985 #: build/C/man3/rexec.3:89
14987 "The port I<inport> specifies which well-known DARPA Internet port to use for "
14988 "the connection; the call I<getservbyname(\"exec\", \"tcp\")> (see "
14989 "B<getservent>(3)) will return a pointer to a structure that contains the "
14990 "necessary port. The protocol for connection is described in detail in "
14994 #. type: Plain text
14995 #: build/C/man3/rexec.3:122
14997 "If the connection succeeds, a socket in the Internet domain of type "
14998 "B<SOCK_STREAM> is returned to the caller, and given to the remote command as "
14999 "I<stdin> and I<stdout>. If I<fd2p> is nonzero, then an auxiliary channel to "
15000 "a control process will be setup, and a descriptor for it will be placed in "
15001 "I<*fd2p>. The control process will return diagnostic output from the "
15002 "command (unit 2) on this channel, and will also accept bytes on this channel "
15003 "as being UNIX signal numbers, to be forwarded to the process group of the "
15004 "command. The diagnostic information returned does not include remote "
15005 "authorization failure, as the secondary connection is set up after "
15006 "authorization has been verified. If I<fd2p> is 0, then the I<stderr> (unit "
15007 "2 of the remote command) will be made the same as the I<stdout> and no "
15008 "provision is made for sending arbitrary signals to the remote process, "
15009 "although you may be able to get its attention by using out-of-band data."
15013 #: build/C/man3/rexec.3:122
15018 #. type: Plain text
15019 #: build/C/man3/rexec.3:138
15021 "The B<rexec>() function works over IPv4 (B<AF_INET>). By contrast, the "
15022 "B<rexec_af>() function provides an extra argument, I<af>, that allows the "
15023 "caller to select the protocol. This argument can be specified as "
15024 "B<AF_INET>, B<AF_INET6>, or B<AF_UNSPEC> (to allow the implementation to "
15025 "select the protocol)."
15028 #. type: Plain text
15029 #: build/C/man3/rexec.3:142
15030 msgid "The B<rexec_af>() function was added to glibc in version 2.2."
15033 #. type: Plain text
15034 #: build/C/man3/rexec.3:149
15035 msgid "The B<rexec>() and B<rexec_af>() functions are not thread-safe."
15038 #. type: Plain text
15039 #: build/C/man3/rexec.3:158
15041 "These functions are not in POSIX.1-2001. The B<rexec>() function first "
15042 "appeared in 4.2BSD, and is present on the BSDs, Solaris, and many other "
15043 "systems. The B<rexec_af>() function is more recent, and less widespread."
15046 #. type: Plain text
15047 #: build/C/man3/rexec.3:162
15048 msgid "The B<rexec>() function sends the unencrypted password across the network."
15051 #. type: Plain text
15052 #: build/C/man3/rexec.3:167
15054 "The underlying service is considered a big security hole and therefore not "
15055 "enabled on many sites; see B<rexecd>(8) for explanations."
15058 #. type: Plain text
15059 #: build/C/man3/rexec.3:169
15060 msgid "B<rcmd>(3), B<rexecd>(8)"
15064 #: build/C/man5/services.5:34
15070 #: build/C/man5/services.5:34
15075 #. type: Plain text
15076 #: build/C/man5/services.5:37
15077 msgid "services - Internet network services list"
15080 #. type: Plain text
15081 #: build/C/man5/services.5:52
15083 "B<services> is a plain ASCII file providing a mapping between human-friendly "
15084 "textual names for internet services, and their underlying assigned port "
15085 "numbers and protocol types. Every networking program should look into this "
15086 "file to get the port number (and protocol) for its service. The C library "
15087 "routines B<getservent>(3), B<getservbyname>(3), B<getservbyport>(3), "
15088 "B<setservent>(3), and B<endservent>(3) support querying this file from "
15092 #. type: Plain text
15093 #: build/C/man5/services.5:58
15095 "Port numbers are assigned by the IANA (Internet Assigned Numbers Authority), "
15096 "and their current policy is to assign both TCP and UDP protocols when "
15097 "assigning a port number. Therefore, most entries will have two entries, "
15098 "even for TCP-only services."
15101 #. type: Plain text
15102 #: build/C/man5/services.5:70
15104 "Port numbers below 1024 (so-called \"low numbered\" ports) can be bound to "
15105 "only by root (see B<bind>(2), B<tcp>(7), and B<udp>(7)). This is so clients "
15106 "connecting to low numbered ports can trust that the service running on the "
15107 "port is the standard implementation, and not a rogue service run by a user "
15108 "of the machine. Well-known port numbers specified by the IANA are normally "
15109 "located in this root-only space."
15112 #. type: Plain text
15113 #: build/C/man5/services.5:85
15115 "The presence of an entry for a service in the B<services> file does not "
15116 "necessarily mean that the service is currently running on the machine. See "
15117 "B<inetd.conf>(5) for the configuration of Internet services offered. Note "
15118 "that not all networking services are started by B<inetd>(8), and so won't "
15119 "appear in B<inetd.conf>(5). In particular, news (NNTP) and mail (SMTP) "
15120 "servers are often initialized from the system boot scripts."
15123 #. type: Plain text
15124 #: build/C/man5/services.5:94
15126 "The location of the B<services> file is defined by B<_PATH_SERVICES> in "
15127 "I<E<lt>netdb.hE<gt>>. This is usually set to I</etc/services>."
15130 #. type: Plain text
15131 #: build/C/man5/services.5:96
15132 msgid "Each line describes one service, and is of the form:"
15135 #. type: Plain text
15136 #: build/C/man5/services.5:98
15137 msgid "I<service-name\\ \\ \\ port>B</>I<protocol\\ \\ \\ >[I<aliases ...>]"
15141 #: build/C/man5/services.5:98
15147 #: build/C/man5/services.5:100
15149 msgid "I<service-name>"
15152 #. type: Plain text
15153 #: build/C/man5/services.5:106
15155 "is the friendly name the service is known by and looked up under. It is "
15156 "case sensitive. Often, the client program is named after the "
15161 #: build/C/man5/services.5:106
15166 #. type: Plain text
15167 #: build/C/man5/services.5:109
15168 msgid "is the port number (in decimal) to use for this service."
15171 #. type: Plain text
15172 #: build/C/man5/services.5:120
15174 "is the type of protocol to be used. This field should match an entry in the "
15175 "B<protocols>(5) file. Typical values include B<tcp> and B<udp>."
15178 #. type: Plain text
15179 #: build/C/man5/services.5:126
15181 "is an optional space or tab separated list of other names for this service. "
15182 "Again, the names are case sensitive."
15185 #. type: Plain text
15186 #: build/C/man5/services.5:128
15187 msgid "Either spaces or tabs may be used to separate the fields."
15190 #. type: Plain text
15191 #: build/C/man5/services.5:132
15193 "Comments are started by the hash sign (#) and continue until the end of the "
15194 "line. Blank lines are skipped."
15197 #. type: Plain text
15198 #: build/C/man5/services.5:143
15200 "The I<service-name> should begin in the first column of the file, since "
15201 "leading spaces are not stripped. I<service-names> can be any printable "
15202 "characters excluding space and tab. However, a conservative choice of "
15203 "characters should be used to minimize compatibility problems. For example, "
15204 "a-z, 0-9, and hyphen (-) would seem a sensible choice."
15207 #. type: Plain text
15208 #: build/C/man5/services.5:152
15210 "Lines not matching this format should not be present in the file. "
15211 "(Currently, they are silently skipped by B<getservent>(3), "
15212 "B<getservbyname>(3), and B<getservbyport>(3). However, this behavior should "
15213 "not be relied on.)"
15216 #. type: Plain text
15217 #: build/C/man5/services.5:169
15218 msgid "A sample B<services> file might look like this:"
15221 #. type: Plain text
15222 #: build/C/man5/services.5:182
15225 "CW<netstat 15/tcp\n"
15226 "qotd 17/tcp quote\n"
15227 "msp 18/tcp # message send protocol\n"
15228 "msp 18/udp # message send protocol\n"
15229 "chargen 19/tcp ttytst source\n"
15230 "chargen 19/udp ttytst source\n"
15232 "# 22 - unassigned\n"
15236 #. type: Plain text
15237 #: build/C/man5/services.5:189
15238 msgid "The Internet network services list"
15242 #: build/C/man5/services.5:189
15244 msgid "I<E<lt>netdb.hE<gt>>"
15248 #. It's not clear when/if the following was ever true;
15249 #. it isn't true for glibc 2.8:
15250 #. There is a maximum of 35 aliases, due to the way the
15251 #. .BR getservent (3)
15252 #. code is written.
15254 #. It's not clear when/if the following was ever true;
15255 #. it isn't true for glibc 2.8:
15256 #. Lines longer than
15258 #. (currently 1024) characters will be ignored by
15259 #. .BR getservent (3),
15260 #. .BR getservbyname (3),
15262 #. .BR getservbyport (3).
15263 #. However, this will also cause the next line to be mis-parsed.
15264 #. type: Plain text
15265 #: build/C/man5/services.5:210
15266 msgid "Definition of B<_PATH_SERVICES>"
15269 #. type: Plain text
15270 #: build/C/man5/services.5:220
15272 "B<listen>(2), B<endservent>(3), B<getservbyname>(3), B<getservbyport>(3), "
15273 "B<getservent>(3), B<setservent>(3), B<inetd.conf>(5), B<protocols>(5), "
15277 #. type: Plain text
15278 #: build/C/man5/services.5:221
15279 msgid "Assigned Numbers RFC, most recently RFC\\ 1700, (AKA STD0002)."
15283 #: build/C/man3/setnetgrent.3:10
15285 msgid "SETNETGRENT"
15288 #. type: Plain text
15289 #: build/C/man3/setnetgrent.3:14
15291 "setnetgrent, endnetgrent, getnetgrent, getnetgrent_r, innetgr - handle "
15292 "network group entries"
15295 #. type: Plain text
15296 #: build/C/man3/setnetgrent.3:19
15298 msgid "B<int setnetgrent(const char *>I<netgroup>B<);>\n"
15301 #. type: Plain text
15302 #: build/C/man3/setnetgrent.3:21
15304 msgid "B<void endnetgrent(void);>\n"
15307 #. type: Plain text
15308 #: build/C/man3/setnetgrent.3:23
15311 "B<int getnetgrent(char **>I<host>B<, char **>I<user>B<, char "
15312 "**>I<domain>B<);>\n"
15315 #. type: Plain text
15316 #: build/C/man3/setnetgrent.3:26
15319 "B<int getnetgrent_r(char **>I<host>B<, char **>I<user>B<,>\n"
15320 "B< char **>I<domain>B<, char *>I<buf>B<, size_t "
15321 ">I<buflen>B<);>\n"
15324 #. type: Plain text
15325 #: build/C/man3/setnetgrent.3:29
15328 "B<int innetgr(const char *>I<netgroup>B<, const char *>I<host>B<,>\n"
15329 "B< const char *>I<user>B<, const char *>I<domain>B<);>\n"
15332 #. type: Plain text
15333 #: build/C/man3/setnetgrent.3:43
15335 "B<setnetgrent>(), B<endnetgrent>(), B<getnetgrent>(), B<getnetgrent_r>(), "
15336 "B<innetgr>(): _BSD_SOURCE || _SVID_SOURCE"
15339 #. type: Plain text
15340 #: build/C/man3/setnetgrent.3:57
15342 "The I<netgroup> is a SunOS invention. A netgroup database is a list of "
15343 "string triples (I<hostname>, I<username>, I<domainname>) or other netgroup "
15344 "names. Any of the elements in a triple can be empty, which means that "
15345 "anything matches. The functions described here allow access to the netgroup "
15346 "databases. The file I</etc/nsswitch.conf> defines what database is "
15350 #. type: Plain text
15351 #: build/C/man3/setnetgrent.3:77
15353 "The B<setnetgrent>() call defines the netgroup that will be searched by "
15354 "subsequent B<getnetgrent>() calls. The B<getnetgrent>() function "
15355 "retrieves the next netgroup entry, and returns pointers in I<host>, I<user>, "
15356 "I<domain>. A null pointer means that the corresponding entry matches any "
15357 "string. The pointers are valid only as long as there is no call to other "
15358 "netgroup-related functions. To avoid this problem you can use the GNU "
15359 "function B<getnetgrent_r>() that stores the strings in the supplied "
15360 "buffer. To free all allocated buffers use B<endnetgrent>()."
15363 #. type: Plain text
15364 #: build/C/man3/setnetgrent.3:86
15366 "In most cases you want to check only if the triplet (I<hostname>, "
15367 "I<username>, I<domainname>) is a member of a netgroup. The function "
15368 "B<innetgr>() can be used for this without calling the above three "
15369 "functions. Again, a null pointer is a wildcard and matches any string. The "
15370 "function is thread-safe."
15373 #. type: Plain text
15374 #: build/C/man3/setnetgrent.3:88
15375 msgid "These functions return 1 on success and 0 for failure."
15378 #. type: Plain text
15379 #: build/C/man3/setnetgrent.3:90
15380 msgid "I</etc/netgroup>"
15383 #. getnetgrent_r() is on Solaris 8 and AIX 5.1, but not the BSDs.
15384 #. type: Plain text
15385 #: build/C/man3/setnetgrent.3:103
15387 "These functions are not in POSIX.1-2001, but B<setnetgrent>(), "
15388 "B<endnetgrent>(), B<getnetgrent>(), and B<innetgr>() are available on most "
15389 "UNIX systems. B<getnetgrent_r>() is not widely available on other systems."
15392 #. type: Plain text
15393 #: build/C/man3/setnetgrent.3:107
15394 msgid "In the BSD implementation, B<setnetgrent>() returns void."
15397 #. type: Plain text
15398 #: build/C/man3/setnetgrent.3:110
15399 msgid "B<sethostent>(3), B<setprotoent>(3), B<setservent>(3)"
15403 #: build/C/man2/shutdown.2:40
15409 #: build/C/man2/shutdown.2:40
15414 #. type: Plain text
15415 #: build/C/man2/shutdown.2:43
15416 msgid "shutdown - shut down part of a full-duplex connection"
15419 #. type: Plain text
15420 #: build/C/man2/shutdown.2:47
15421 msgid "B<int shutdown(int >I<sockfd>B<, int >I<how>B<);>"
15424 #. type: Plain text
15425 #: build/C/man2/shutdown.2:69
15427 "The B<shutdown>() call causes all or part of a full-duplex connection on "
15428 "the socket associated with I<sockfd> to be shut down. If I<how> is "
15429 "B<SHUT_RD>, further receptions will be disallowed. If I<how> is B<SHUT_WR>, "
15430 "further transmissions will be disallowed. If I<how> is B<SHUT_RDWR>, "
15431 "further receptions and transmissions will be disallowed."
15434 #. type: Plain text
15435 #: build/C/man2/shutdown.2:79
15436 msgid "I<sockfd> is not a valid descriptor."
15439 #. type: Plain text
15440 #: build/C/man2/shutdown.2:84
15441 msgid "An invalid value was specified in I<how> (but see BUGS)."
15444 #. type: Plain text
15445 #: build/C/man2/shutdown.2:87
15446 msgid "The specified socket is not connected."
15449 #. type: Plain text
15450 #: build/C/man2/shutdown.2:91
15451 msgid "I<sockfd> is a file, not a socket."
15454 #. type: Plain text
15455 #: build/C/man2/shutdown.2:95
15457 "POSIX.1-2001, 4.4BSD (the B<shutdown>() function call first appeared in "
15461 #. type: Plain text
15462 #: build/C/man2/shutdown.2:104
15464 "The constants B<SHUT_RD>, B<SHUT_WR>, B<SHUT_RDWR> have the value 0, 1, 2, "
15465 "respectively, and are defined in I<E<lt>sys/socket.hE<gt>> since "
15470 #. https://bugzilla.kernel.org/show_bug.cgi?id=47111
15471 #. type: Plain text
15472 #: build/C/man2/shutdown.2:113
15474 "As currently implemented, checks for the validity of I<how> are done in "
15475 "domain-specific code, and not all domains perform these checks. Most "
15476 "notably, UNIX domain sockets simply ignore invalid values; this may change "
15480 #. type: Plain text
15481 #: build/C/man2/shutdown.2:116
15482 msgid "B<connect>(2), B<socket>(2), B<socket>(7)"
15486 #: build/C/man7/tcp.7:76
15492 #: build/C/man7/tcp.7:76
15497 #. type: Plain text
15498 #: build/C/man7/tcp.7:79
15499 msgid "tcp - TCP protocol"
15502 #. type: Plain text
15503 #: build/C/man7/tcp.7:85
15504 msgid "B<#include E<lt>netinet/tcp.hE<gt>>"
15507 #. type: Plain text
15508 #: build/C/man7/tcp.7:87
15509 msgid "B<tcp_socket = socket(AF_INET, SOCK_STREAM, 0);>"
15512 #. type: Plain text
15513 #: build/C/man7/tcp.7:100
15515 "This is an implementation of the TCP protocol defined in RFC\\ 793, RFC\\ "
15516 "1122 and RFC\\ 2001 with the NewReno and SACK extensions. It provides a "
15517 "reliable, stream-oriented, full-duplex connection between two sockets on top "
15518 "of B<ip>(7), for both v4 and v6 versions. TCP guarantees that the data "
15519 "arrives in order and retransmits lost packets. It generates and checks a "
15520 "per-packet checksum to catch transmission errors. TCP does not preserve "
15521 "record boundaries."
15524 #. type: Plain text
15525 #: build/C/man7/tcp.7:119
15527 "A newly created TCP socket has no remote or local address and is not fully "
15528 "specified. To create an outgoing TCP connection use B<connect>(2) to "
15529 "establish a connection to another TCP socket. To receive new incoming "
15530 "connections, first B<bind>(2) the socket to a local address and port and "
15531 "then call B<listen>(2) to put the socket into the listening state. After "
15532 "that a new socket for each incoming connection can be accepted using "
15533 "B<accept>(2). A socket which has had B<accept>(2) or B<connect>(2) "
15534 "successfully called on it is fully specified and may transmit data. Data "
15535 "cannot be transmitted on listening or not yet connected sockets."
15538 #. type: Plain text
15539 #: build/C/man7/tcp.7:139
15541 "Linux supports RFC\\ 1323 TCP high performance extensions. These include "
15542 "Protection Against Wrapped Sequence Numbers (PAWS), Window Scaling and "
15543 "Timestamps. Window scaling allows the use of large (E<gt> 64K) TCP windows "
15544 "in order to support links with high latency or bandwidth. To make use of "
15545 "them, the send and receive buffer sizes must be increased. They can be set "
15546 "globally with the I</proc/sys/net/ipv4/tcp_wmem> and "
15547 "I</proc/sys/net/ipv4/tcp_rmem> files, or on individual sockets by using the "
15548 "B<SO_SNDBUF> and B<SO_RCVBUF> socket options with the B<setsockopt>(2) "
15552 #. type: Plain text
15553 #: build/C/man7/tcp.7:170
15555 "The maximum sizes for socket buffers declared via the B<SO_SNDBUF> and "
15556 "B<SO_RCVBUF> mechanisms are limited by the values in the "
15557 "I</proc/sys/net/core/rmem_max> and I</proc/sys/net/core/wmem_max> files. "
15558 "Note that TCP actually allocates twice the size of the buffer requested in "
15559 "the B<setsockopt>(2) call, and so a succeeding B<getsockopt>(2) call will "
15560 "not return the same size of buffer as requested in the B<setsockopt>(2) "
15561 "call. TCP uses the extra space for administrative purposes and internal "
15562 "kernel structures, and the I</proc> file values reflect the larger sizes "
15563 "compared to the actual TCP windows. On individual connections, the socket "
15564 "buffer size must be set prior to the B<listen>(2) or B<connect>(2) calls "
15565 "in order to have it take effect. See B<socket>(7) for more information."
15568 #. type: Plain text
15569 #: build/C/man7/tcp.7:202
15571 "TCP supports urgent data. Urgent data is used to signal the receiver that "
15572 "some important message is part of the data stream and that it should be "
15573 "processed as soon as possible. To send urgent data specify the B<MSG_OOB> "
15574 "option to B<send>(2). When urgent data is received, the kernel sends a "
15575 "B<SIGURG> signal to the process or process group that has been set as the "
15576 "socket \"owner\" using the B<SIOCSPGRP> or B<FIOSETOWN> ioctls (or the "
15577 "POSIX.1-2001-specified B<fcntl>(2) B<F_SETOWN> operation). When the "
15578 "B<SO_OOBINLINE> socket option is enabled, urgent data is put into the normal "
15579 "data stream (a program can test for its location using the B<SIOCATMARK> "
15580 "ioctl described below), otherwise it can be received only when the "
15581 "B<MSG_OOB> flag is set for B<recv>(2) or B<recvmsg>(2)."
15584 #. type: Plain text
15585 #: build/C/man7/tcp.7:210
15587 "Linux 2.4 introduced a number of changes for improved throughput and "
15588 "scaling, as well as enhanced functionality. Some of these features include "
15589 "support for zero-copy B<sendfile>(2), Explicit Congestion Notification, new "
15590 "management of TIME_WAIT sockets, keep-alive socket options and support for "
15591 "Duplicate SACK extensions."
15595 #: build/C/man7/tcp.7:210
15597 msgid "Address formats"
15600 #. type: Plain text
15601 #: build/C/man7/tcp.7:219
15603 "TCP is built on top of IP (see B<ip>(7)). The address formats defined by "
15604 "B<ip>(7) apply to TCP. TCP supports point-to-point communication only; "
15605 "broadcasting and multicasting are not supported."
15608 #. type: Plain text
15609 #: build/C/man7/tcp.7:231
15611 "System-wide TCP parameter settings can be accessed by files in the directory "
15612 "I</proc/sys/net/ipv4/>. In addition, most IP I</proc> interfaces also apply "
15613 "to TCP; see B<ip>(7). Variables described as I<Boolean> take an integer "
15614 "value, with a nonzero value (\"true\") meaning that the corresponding option "
15615 "is enabled, and a zero value (\"false\") meaning that the option is "
15620 #: build/C/man7/tcp.7:231
15622 msgid "I<tcp_abc> (Integer; default: 0; since Linux 2.6.15)"
15625 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
15626 #. type: Plain text
15627 #: build/C/man7/tcp.7:239
15629 "Control the Appropriate Byte Count (ABC), defined in RFC 3465. ABC is a way "
15630 "of increasing the congestion window (I<cwnd>) more slowly in response to "
15631 "partial acknowledgments. Possible values are:"
15635 #: build/C/man7/tcp.7:240 build/C/man7/tcp.7:428 build/C/man7/tcp.7:449 build/C/man7/tcp.7:593
15640 #. type: Plain text
15641 #: build/C/man7/tcp.7:244
15642 msgid "increase I<cwnd> once per acknowledgment (no ABC)"
15646 #: build/C/man7/tcp.7:244 build/C/man7/tcp.7:430 build/C/man7/tcp.7:456 build/C/man7/tcp.7:595
15651 #. type: Plain text
15652 #: build/C/man7/tcp.7:248
15653 msgid "increase I<cwnd> once per acknowledgment of full sized segment"
15657 #: build/C/man7/tcp.7:248 build/C/man7/tcp.7:432 build/C/man7/tcp.7:463 build/C/man7/tcp.7:597
15662 #. type: Plain text
15663 #: build/C/man7/tcp.7:253
15665 "allow increase I<cwnd> by two if acknowledgment is of two segments to "
15666 "compensate for delayed acknowledgments."
15670 #: build/C/man7/tcp.7:254
15672 msgid "I<tcp_abort_on_overflow> (Boolean; default: disabled; since Linux 2.4)"
15676 #. type: Plain text
15677 #: build/C/man7/tcp.7:266
15679 "Enable resetting connections if the listening service is too slow and unable "
15680 "to keep up and accept them. It means that if overflow occurred due to a "
15681 "burst, the connection will recover. Enable this option I<only> if you are "
15682 "really sure that the listening daemon cannot be tuned to accept connections "
15683 "faster. Enabling this option can harm the clients of your server."
15687 #: build/C/man7/tcp.7:266
15689 msgid "I<tcp_adv_win_scale> (integer; default: 2; since Linux 2.4)"
15692 #. Since 2.4.0-test7
15693 #. type: Plain text
15694 #: build/C/man7/tcp.7:278
15696 "Count buffering overhead as I<bytes/2^tcp_adv_win_scale>, if "
15697 "I<tcp_adv_win_scale> is greater than 0; or "
15698 "I<bytes-bytes/2^(-tcp_adv_win_scale)>, if I<tcp_adv_win_scale> is less than "
15699 "or equal to zero."
15702 #. type: Plain text
15703 #: build/C/man7/tcp.7:291
15705 "The socket receive buffer space is shared between the application and "
15706 "kernel. TCP maintains part of the buffer as the TCP window, this is the "
15707 "size of the receive window advertised to the other end. The rest of the "
15708 "space is used as the \"application\" buffer, used to isolate the network "
15709 "from scheduling and application latencies. The I<tcp_adv_win_scale> default "
15710 "value of 2 implies that the space used for the application buffer is one "
15711 "fourth that of the total."
15715 #: build/C/man7/tcp.7:291
15718 "I<tcp_allowed_congestion_control> (String; default: see text; since Linux "
15722 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
15723 #. type: Plain text
15724 #: build/C/man7/tcp.7:304
15726 "Show/set the congestion control algorithm choices available to unprivileged "
15727 "processes (see the description of the B<TCP_CONGESTION> socket option). The "
15728 "items in the list are separated by white space and terminated by a newline "
15729 "character. The list is a subset of those listed in "
15730 "I<tcp_available_congestion_control>. The default value for this list is "
15731 "\"reno\" plus the default setting of I<tcp_congestion_control>."
15735 #: build/C/man7/tcp.7:304
15737 msgid "I<tcp_autocorking> (Boolean; default: enabled; since Linux 3.14)"
15740 #. commit f54b311142a92ea2e42598e347b84e1655caf8e3
15741 #. Text heavily based on Documentation/networking/ip-sysctl.txt
15742 #. type: Plain text
15743 #: build/C/man7/tcp.7:321
15745 "If this option is enabled, the kernel tries to coalesce small writes (from "
15746 "consecutive B<write>(2) and B<sendmsg>(2) calls) as much as possible, in "
15747 "order to decrease the total number of sent packets. Coalescing is done if "
15748 "at least one prior packet for the flow is waiting in Qdisc queues or device "
15749 "transmit queue. Applications can still use the B<TCP_CORK> socket option to "
15750 "obtain optimal behavior when they know how/when to uncork their sockets."
15754 #: build/C/man7/tcp.7:321
15756 msgid "I<tcp_available_congestion_control> (String; read-only; since Linux 2.4.20)"
15759 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
15760 #. type: Plain text
15761 #: build/C/man7/tcp.7:332
15763 "Show a list of the congestion-control algorithms that are registered. The "
15764 "items in the list are separated by white space and terminated by a newline "
15765 "character. This list is a limiting set for the list in "
15766 "I<tcp_allowed_congestion_control>. More congestion-control algorithms may "
15767 "be available as modules, but not loaded."
15771 #: build/C/man7/tcp.7:332
15773 msgid "I<tcp_app_win> (integer; default: 31; since Linux 2.4)"
15776 #. Since 2.4.0-test7
15777 #. type: Plain text
15778 #: build/C/man7/tcp.7:337
15780 "This variable defines how many bytes of the TCP window are reserved for "
15781 "buffering overhead."
15785 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
15786 #. type: Plain text
15787 #: build/C/man7/tcp.7:343
15789 "A maximum of (I<window/2^tcp_app_win>, mss) bytes in the window are reserved "
15790 "for the application buffer. A value of 0 implies that no amount is "
15795 #: build/C/man7/tcp.7:343
15797 msgid "I<tcp_base_mss> (Integer; default: 512; since Linux 2.6.17)"
15801 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
15802 #. type: Plain text
15803 #: build/C/man7/tcp.7:352
15805 "The initial value of I<search_low> to be used by the packetization layer "
15806 "Path MTU discovery (MTU probing). If MTU probing is enabled, this is the "
15807 "initial MSS used by the connection."
15811 #: build/C/man7/tcp.7:352
15813 msgid "I<tcp_bic> (Boolean; default: disabled; Linux 2.4.27/2.6.6 to 2.6.13)"
15817 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
15818 #. type: Plain text
15819 #: build/C/man7/tcp.7:366
15821 "Enable BIC TCP congestion control algorithm. BIC-TCP is a sender-side only "
15822 "change that ensures a linear RTT fairness under large windows while offering "
15823 "both scalability and bounded TCP-friendliness. The protocol combines two "
15824 "schemes called additive increase and binary search increase. When the "
15825 "congestion window is large, additive increase with a large increment ensures "
15826 "linear RTT fairness as well as good scalability. Under small congestion "
15827 "windows, binary search increase provides TCP friendliness."
15831 #: build/C/man7/tcp.7:366
15833 msgid "I<tcp_bic_low_window> (integer; default: 14; Linux 2.4.27/2.6.6 to 2.6.13)"
15837 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
15838 #. type: Plain text
15839 #: build/C/man7/tcp.7:373
15841 "Set the threshold window (in packets) where BIC TCP starts to adjust the "
15842 "congestion window. Below this threshold BIC TCP behaves the same as the "
15843 "default TCP Reno."
15847 #: build/C/man7/tcp.7:373
15850 "I<tcp_bic_fast_convergence> (Boolean; default: enabled; Linux 2.4.27/2.6.6 "
15854 #. type: Plain text
15855 #: build/C/man7/tcp.7:377
15857 "Force BIC TCP to more quickly respond to changes in congestion window. "
15858 "Allows two flows sharing the same connection to converge more rapidly."
15862 #: build/C/man7/tcp.7:377
15864 msgid "I<tcp_congestion_control> (String; default: see text; since Linux 2.4.13)"
15867 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
15868 #. type: Plain text
15869 #: build/C/man7/tcp.7:384
15871 "Set the default congestion-control algorithm to be used for new "
15872 "connections. The algorithm \"reno\" is always available, but additional "
15873 "choices may be available depending on kernel configuration. The default "
15874 "value for this file is set as part of kernel configuration."
15878 #: build/C/man7/tcp.7:384
15880 msgid "I<tcp_dma_copybreak> (integer; default: 4096; since Linux 2.6.24)"
15883 #. type: Plain text
15884 #: build/C/man7/tcp.7:391
15886 "Lower limit, in bytes, of the size of socket reads that will be offloaded to "
15887 "a DMA copy engine, if one is present in the system and the kernel was "
15888 "configured with the B<CONFIG_NET_DMA> option."
15892 #: build/C/man7/tcp.7:391
15894 msgid "I<tcp_dsack> (Boolean; default: enabled; since Linux 2.4)"
15897 #. Since 2.4.0-test7
15898 #. type: Plain text
15899 #: build/C/man7/tcp.7:395
15900 msgid "Enable RFC\\ 2883 TCP Duplicate SACK support."
15904 #: build/C/man7/tcp.7:395
15906 msgid "I<tcp_ecn> (Boolean; default: disabled; since Linux 2.4)"
15909 #. Since 2.4.0-test7
15910 #. type: Plain text
15911 #: build/C/man7/tcp.7:402
15913 "Enable RFC\\ 2884 Explicit Congestion Notification. When enabled, "
15914 "connectivity to some destinations could be affected due to older, "
15915 "misbehaving routers along the path causing connections to be dropped."
15919 #: build/C/man7/tcp.7:402
15921 msgid "I<tcp_fack> (Boolean; default: enabled; since Linux 2.2)"
15925 #. type: Plain text
15926 #: build/C/man7/tcp.7:406
15927 msgid "Enable TCP Forward Acknowledgement support."
15931 #: build/C/man7/tcp.7:406
15933 msgid "I<tcp_fin_timeout> (integer; default: 60; since Linux 2.2)"
15938 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
15939 #. type: Plain text
15940 #: build/C/man7/tcp.7:416
15942 "This specifies how many seconds to wait for a final FIN packet before the "
15943 "socket is forcibly closed. This is strictly a violation of the TCP "
15944 "specification, but required to prevent denial-of-service attacks. In Linux "
15945 "2.2, the default value was 180."
15949 #: build/C/man7/tcp.7:416
15951 msgid "I<tcp_frto> (integer; default: 0; since Linux 2.4.21/2.6)"
15954 #. Since 2.4.21/2.5.43
15955 #. type: Plain text
15956 #: build/C/man7/tcp.7:425
15958 "Enable F-RTO, an enhanced recovery algorithm for TCP retransmission timeouts "
15959 "(RTOs). It is particularly beneficial in wireless environments where packet "
15960 "loss is typically due to random radio interference rather than intermediate "
15961 "router congestion. See RFC 4138 for more details."
15964 #. type: Plain text
15965 #: build/C/man7/tcp.7:427
15966 msgid "This file can have one of the following values:"
15969 #. type: Plain text
15970 #: build/C/man7/tcp.7:430
15974 #. type: Plain text
15975 #: build/C/man7/tcp.7:432
15976 msgid "The basic version F-RTO algorithm is enabled."
15979 #. type: Plain text
15980 #: build/C/man7/tcp.7:437
15982 "Enable SACK-enhanced F-RTO if flow uses SACK. The basic version can be used "
15983 "also when SACK is in use though in that case scenario(s) exists where F-RTO "
15984 "interacts badly with the packet counting of the SACK-enabled TCP flow."
15987 #. type: Plain text
15988 #: build/C/man7/tcp.7:441
15990 "Before Linux 2.6.22, this parameter was a Boolean value, supporting just "
15991 "values 0 and 1 above."
15995 #: build/C/man7/tcp.7:441
15997 msgid "I<tcp_frto_response> (integer; default: 0; since Linux 2.6.22)"
16000 #. type: Plain text
16001 #: build/C/man7/tcp.7:448
16003 "When F-RTO has detected that a TCP retransmission timeout was spurious (i.e, "
16004 "the timeout would have been avoided had TCP set a longer retransmission "
16005 "timeout), TCP has several options concerning what to do next. Possible "
16009 #. type: Plain text
16010 #: build/C/man7/tcp.7:456
16012 "Rate halving based; a smooth and conservative response, results in halved "
16013 "congestion window (I<cwnd>) and slow-start threshold (I<ssthresh>) after "
16017 #. type: Plain text
16018 #: build/C/man7/tcp.7:463
16020 "Very conservative response; not recommended because even though being valid, "
16021 "it interacts poorly with the rest of Linux TCP; halves I<cwnd> and "
16022 "I<ssthresh> immediately."
16025 #. type: Plain text
16026 #: build/C/man7/tcp.7:472
16028 "Aggressive response; undoes congestion-control measures that are now known "
16029 "to be unnecessary (ignoring the possibility of a lost retransmission that "
16030 "would require TCP to be more cautious); I<cwnd> and I<ssthresh> are restored "
16031 "to the values prior to timeout."
16035 #: build/C/man7/tcp.7:473
16037 msgid "I<tcp_keepalive_intvl> (integer; default: 75; since Linux 2.4)"
16041 #. type: Plain text
16042 #: build/C/man7/tcp.7:477
16043 msgid "The number of seconds between TCP keep-alive probes."
16047 #: build/C/man7/tcp.7:477
16049 msgid "I<tcp_keepalive_probes> (integer; default: 9; since Linux 2.2)"
16053 #. type: Plain text
16054 #: build/C/man7/tcp.7:483
16056 "The maximum number of TCP keep-alive probes to send before giving up and "
16057 "killing the connection if no response is obtained from the other end."
16061 #: build/C/man7/tcp.7:483
16063 msgid "I<tcp_keepalive_time> (integer; default: 7200; since Linux 2.2)"
16067 #. type: Plain text
16068 #: build/C/man7/tcp.7:495
16070 "The number of seconds a connection needs to be idle before TCP begins "
16071 "sending out keep-alive probes. Keep-alives are sent only when the "
16072 "B<SO_KEEPALIVE> socket option is enabled. The default value is 7200 seconds "
16073 "(2 hours). An idle connection is terminated after approximately an "
16074 "additional 11 minutes (9 probes an interval of 75 seconds apart) when "
16075 "keep-alive is enabled."
16079 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
16080 #. type: Plain text
16081 #: build/C/man7/tcp.7:500
16083 "Note that underlying connection tracking mechanisms and application timeouts "
16084 "may be much shorter."
16088 #: build/C/man7/tcp.7:500
16090 msgid "I<tcp_low_latency> (Boolean; default: disabled; since Linux 2.4.21/2.6)"
16093 #. Since 2.4.21/2.5.60
16094 #. type: Plain text
16095 #: build/C/man7/tcp.7:508
16097 "If enabled, the TCP stack makes decisions that prefer lower latency as "
16098 "opposed to higher throughput. It this option is disabled, then higher "
16099 "throughput is preferred. An example of an application where this default "
16100 "should be changed would be a Beowulf compute cluster."
16104 #: build/C/man7/tcp.7:508
16106 msgid "I<tcp_max_orphans> (integer; default: see below; since Linux 2.4)"
16110 #. type: Plain text
16111 #: build/C/man7/tcp.7:522
16113 "The maximum number of orphaned (not attached to any user file handle) TCP "
16114 "sockets allowed in the system. When this number is exceeded, the orphaned "
16115 "connection is reset and a warning is printed. This limit exists only to "
16116 "prevent simple denial-of-service attacks. Lowering this limit is not "
16117 "recommended. Network conditions might require you to increase the number of "
16118 "orphans allowed, but note that each orphan can eat up to ~64K of unswappable "
16119 "memory. The default initial value is set equal to the kernel parameter "
16120 "NR_FILE. This initial default is adjusted depending on the memory in the "
16125 #: build/C/man7/tcp.7:522
16127 msgid "I<tcp_max_syn_backlog> (integer; default: see below; since Linux 2.2)"
16131 #. type: Plain text
16132 #: build/C/man7/tcp.7:539
16134 "The maximum number of queued connection requests which have still not "
16135 "received an acknowledgement from the connecting client. If this number is "
16136 "exceeded, the kernel will begin dropping requests. The default value of 256 "
16137 "is increased to 1024 when the memory present in the system is adequate or "
16138 "greater (E<gt>= 128Mb), and reduced to 128 for those systems with very low "
16139 "memory (E<lt>= 32Mb). It is recommended that if this needs to be increased "
16140 "above 1024, TCP_SYNQ_HSIZE in I<include/net/tcp.h> be modified to keep "
16141 "TCP_SYNQ_HSIZE*16E<lt>=tcp_max_syn_backlog, and the kernel be recompiled."
16145 #: build/C/man7/tcp.7:539
16147 msgid "I<tcp_max_tw_buckets> (integer; default: see below; since Linux 2.4)"
16151 #. type: Plain text
16152 #: build/C/man7/tcp.7:549
16154 "The maximum number of sockets in TIME_WAIT state allowed in the system. "
16155 "This limit exists only to prevent simple denial-of-service attacks. The "
16156 "default value of NR_FILE*2 is adjusted depending on the memory in the "
16157 "system. If this number is exceeded, the socket is closed and a warning is "
16162 #: build/C/man7/tcp.7:549
16164 msgid "I<tcp_moderate_rcvbuf> (Boolean; default: enabled; since Linux 2.4.17/2.6.7)"
16167 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
16168 #. type: Plain text
16169 #: build/C/man7/tcp.7:556
16171 "If enabled, TCP performs receive buffer auto-tuning, attempting to "
16172 "automatically size the buffer (no greater than I<tcp_rmem[2]>) to match the "
16173 "size required by the path for full throughput."
16177 #: build/C/man7/tcp.7:556
16179 msgid "I<tcp_mem> (since Linux 2.4)"
16182 #. Since 2.4.0-test7
16183 #. type: Plain text
16184 #: build/C/man7/tcp.7:568
16186 "This is a vector of 3 integers: [low, pressure, high]. These bounds, "
16187 "measured in units of the system page size, are used by TCP to track its "
16188 "memory usage. The defaults are calculated at boot time from the amount of "
16189 "available memory. (TCP can only use I<low memory> for this, which is "
16190 "limited to around 900 megabytes on 32-bit systems. 64-bit systems do not "
16191 "suffer this limitation.)"
16195 #: build/C/man7/tcp.7:569
16200 #. type: Plain text
16201 #: build/C/man7/tcp.7:573
16203 "TCP doesn't regulate its memory allocation when the number of pages it has "
16204 "allocated globally is below this number."
16208 #: build/C/man7/tcp.7:573 build/C/man7/udp.7:151
16210 msgid "I<pressure>"
16213 #. type: Plain text
16214 #: build/C/man7/tcp.7:582
16216 "When the amount of memory allocated by TCP exceeds this number of pages, TCP "
16217 "moderates its memory consumption. This memory pressure state is exited once "
16218 "the number of pages allocated falls below the I<low> mark."
16222 #: build/C/man7/tcp.7:582
16227 #. type: Plain text
16228 #: build/C/man7/tcp.7:586
16230 "The maximum number of pages, globally, that TCP will allocate. This value "
16231 "overrides any other limits imposed by the kernel."
16235 #: build/C/man7/tcp.7:587
16237 msgid "I<tcp_mtu_probing> (integer; default: 0; since Linux 2.6.17)"
16240 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
16241 #. type: Plain text
16242 #: build/C/man7/tcp.7:592
16244 "This parameter controls TCP Packetization-Layer Path MTU Discovery. The "
16245 "following values may be assigned to the file:"
16248 #. type: Plain text
16249 #: build/C/man7/tcp.7:595
16253 #. type: Plain text
16254 #: build/C/man7/tcp.7:597
16255 msgid "Disabled by default, enabled when an ICMP black hole detected"
16258 #. type: Plain text
16259 #: build/C/man7/tcp.7:600
16260 msgid "Always enabled, use initial MSS of I<tcp_base_mss>."
16264 #: build/C/man7/tcp.7:601
16266 msgid "I<tcp_no_metrics_save> (Boolean; default: disabled; since Linux 2.6.6)"
16269 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
16270 #. type: Plain text
16271 #: build/C/man7/tcp.7:612
16273 "By default, TCP saves various connection metrics in the route cache when the "
16274 "connection closes, so that connections established in the near future can "
16275 "use these to set initial conditions. Usually, this increases overall "
16276 "performance, but it may sometimes cause performance degradation. If "
16277 "I<tcp_no_metrics_save> is enabled, TCP will not cache metrics on closing "
16282 #: build/C/man7/tcp.7:612
16284 msgid "I<tcp_orphan_retries> (integer; default: 8; since Linux 2.4)"
16288 #. type: Plain text
16289 #: build/C/man7/tcp.7:617
16291 "The maximum number of attempts made to probe the other end of a connection "
16292 "which has been closed by our end."
16296 #: build/C/man7/tcp.7:617
16298 msgid "I<tcp_reordering> (integer; default: 3; since Linux 2.4)"
16301 #. Since 2.4.0-test7
16302 #. type: Plain text
16303 #: build/C/man7/tcp.7:626
16305 "The maximum a packet can be reordered in a TCP packet stream without TCP "
16306 "assuming packet loss and going into slow start. It is not advisable to "
16307 "change this number. This is a packet reordering detection metric designed "
16308 "to minimize unnecessary back off and retransmits provoked by reordering of "
16309 "packets on a connection."
16313 #: build/C/man7/tcp.7:626
16315 msgid "I<tcp_retrans_collapse> (Boolean; default: enabled; since Linux 2.2)"
16319 #. type: Plain text
16320 #: build/C/man7/tcp.7:630
16321 msgid "Try to send full-sized packets during retransmit."
16325 #: build/C/man7/tcp.7:630
16327 msgid "I<tcp_retries1> (integer; default: 3; since Linux 2.2)"
16331 #. type: Plain text
16332 #: build/C/man7/tcp.7:640
16334 "The number of times TCP will attempt to retransmit a packet on an "
16335 "established connection normally, without the extra effort of getting the "
16336 "network layers involved. Once we exceed this number of retransmits, we "
16337 "first have the network layer update the route if possible before each new "
16338 "retransmit. The default is the RFC specified minimum of 3."
16342 #: build/C/man7/tcp.7:640
16344 msgid "I<tcp_retries2> (integer; default: 15; since Linux 2.2)"
16348 #. type: Plain text
16349 #: build/C/man7/tcp.7:650
16351 "The maximum number of times a TCP packet is retransmitted in established "
16352 "state before giving up. The default value is 15, which corresponds to a "
16353 "duration of approximately between 13 to 30 minutes, depending on the "
16354 "retransmission timeout. The RFC\\ 1122 specified minimum limit of 100 "
16355 "seconds is typically deemed too short."
16359 #: build/C/man7/tcp.7:650
16361 msgid "I<tcp_rfc1337> (Boolean; default: disabled; since Linux 2.2)"
16365 #. type: Plain text
16366 #: build/C/man7/tcp.7:658
16368 "Enable TCP behavior conformant with RFC\\ 1337. When disabled, if a RST is "
16369 "received in TIME_WAIT state, we close the socket immediately without waiting "
16370 "for the end of the TIME_WAIT period."
16374 #: build/C/man7/tcp.7:658
16376 msgid "I<tcp_rmem> (since Linux 2.4)"
16379 #. Since 2.4.0-test7
16380 #. type: Plain text
16381 #: build/C/man7/tcp.7:666
16383 "This is a vector of 3 integers: [min, default, max]. These parameters are "
16384 "used by TCP to regulate receive buffer sizes. TCP dynamically adjusts the "
16385 "size of the receive buffer from the defaults listed below, in the range of "
16386 "these values, depending on memory available in the system."
16390 #: build/C/man7/tcp.7:667 build/C/man7/tcp.7:844 build/C/man7/udp.7:145
16395 #. type: Plain text
16396 #: build/C/man7/tcp.7:682
16398 "minimum size of the receive buffer used by each TCP socket. The default "
16399 "value is the system page size. (On Linux 2.4, the default value is 4K, "
16400 "lowered to B<PAGE_SIZE> bytes in low-memory systems.) This value is used to "
16401 "ensure that in memory pressure mode, allocations below this size will still "
16402 "succeed. This is not used to bound the size of the receive buffer declared "
16403 "using B<SO_RCVBUF> on a socket."
16407 #: build/C/man7/tcp.7:682 build/C/man7/tcp.7:854
16412 #. type: Plain text
16413 #: build/C/man7/tcp.7:696
16415 "the default size of the receive buffer for a TCP socket. This value "
16416 "overwrites the initial default buffer size from the generic global "
16417 "I<net.core.rmem_default> defined for all protocols. The default value is "
16418 "87380 bytes. (On Linux 2.4, this will be lowered to 43689 in low-memory "
16419 "systems.) If larger receive buffer sizes are desired, this value should be "
16420 "increased (to affect all sockets). To employ large TCP windows, the "
16421 "I<net.ipv4.tcp_window_scaling> must be enabled (default)."
16425 #: build/C/man7/tcp.7:696 build/C/man7/tcp.7:868 build/C/man7/udp.7:157
16430 #. type: Plain text
16431 #: build/C/man7/tcp.7:705
16433 "the maximum size of the receive buffer used by each TCP socket. This value "
16434 "does not override the global I<net.core.rmem_max>. This is not used to "
16435 "limit the size of the receive buffer declared using B<SO_RCVBUF> on a "
16436 "socket. The default value is calculated using the formula"
16439 #. type: Plain text
16440 #: build/C/man7/tcp.7:707
16442 msgid " max(87380, min(4MB, I<tcp_mem>[1]*PAGE_SIZE/128))\n"
16445 #. type: Plain text
16446 #: build/C/man7/tcp.7:710
16448 "(On Linux 2.4, the default is 87380*2 bytes, lowered to 87380 in low-memory "
16453 #: build/C/man7/tcp.7:711
16455 msgid "I<tcp_sack> (Boolean; default: enabled; since Linux 2.2)"
16459 #. type: Plain text
16460 #: build/C/man7/tcp.7:715
16461 msgid "Enable RFC\\ 2018 TCP Selective Acknowledgements."
16465 #: build/C/man7/tcp.7:715
16467 msgid "I<tcp_slow_start_after_idle> (Boolean; default: enabled; since Linux 2.6.18)"
16470 #. The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
16471 #. type: Plain text
16472 #: build/C/man7/tcp.7:723
16474 "If enabled, provide RFC 2861 behavior and time out the congestion window "
16475 "after an idle period. An idle period is defined as the current RTO "
16476 "(retransmission timeout). If disabled, the congestion window will not be "
16477 "timed out after an idle period."
16481 #: build/C/man7/tcp.7:723
16483 msgid "I<tcp_stdurg> (Boolean; default: disabled; since Linux 2.2)"
16487 #. RFC 793 was ambiguous in its specification of the meaning of the
16488 #. urgent pointer. RFC 1122 (and RFC 961) fixed on a particular
16489 #. resolution of this ambiguity (unfortunately the "wrong" one).
16490 #. type: Plain text
16491 #: build/C/man7/tcp.7:737
16493 "If this option is enabled, then use the RFC\\ 1122 interpretation of the TCP "
16494 "urgent-pointer field. According to this interpretation, the urgent pointer "
16495 "points to the last byte of urgent data. If this option is disabled, then "
16496 "use the BSD-compatible interpretation of the urgent pointer: the urgent "
16497 "pointer points to the first byte after the urgent data. Enabling this "
16498 "option may lead to interoperability problems."
16502 #: build/C/man7/tcp.7:737
16504 msgid "I<tcp_syn_retries> (integer; default: 5; since Linux 2.2)"
16508 #. type: Plain text
16509 #: build/C/man7/tcp.7:744
16511 "The maximum number of times initial SYNs for an active TCP connection "
16512 "attempt will be retransmitted. This value should not be higher than 255. "
16513 "The default value is 5, which corresponds to approximately 180 seconds."
16517 #: build/C/man7/tcp.7:744
16519 msgid "I<tcp_synack_retries> (integer; default: 5; since Linux 2.2)"
16523 #. type: Plain text
16524 #: build/C/man7/tcp.7:750
16526 "The maximum number of times a SYN/ACK segment for a passive TCP connection "
16527 "will be retransmitted. This number should not be higher than 255."
16531 #: build/C/man7/tcp.7:750
16533 msgid "I<tcp_syncookies> (Boolean; since Linux 2.2)"
16537 #. type: Plain text
16538 #: build/C/man7/tcp.7:770
16540 "Enable TCP syncookies. The kernel must be compiled with "
16541 "B<CONFIG_SYN_COOKIES>. Send out syncookies when the syn backlog queue of a "
16542 "socket overflows. The syncookies feature attempts to protect a socket from "
16543 "a SYN flood attack. This should be used as a last resort, if at all. This "
16544 "is a violation of the TCP protocol, and conflicts with other areas of TCP "
16545 "such as TCP extensions. It can cause problems for clients and relays. It "
16546 "is not recommended as a tuning mechanism for heavily loaded servers to help "
16547 "with overloaded or misconfigured conditions. For recommended alternatives "
16548 "see I<tcp_max_syn_backlog>, I<tcp_synack_retries>, and "
16549 "I<tcp_abort_on_overflow>."
16553 #: build/C/man7/tcp.7:770
16555 msgid "I<tcp_timestamps> (Boolean; default: enabled; since Linux 2.2)"
16559 #. type: Plain text
16560 #: build/C/man7/tcp.7:774
16561 msgid "Enable RFC\\ 1323 TCP timestamps."
16565 #: build/C/man7/tcp.7:774
16567 msgid "I<tcp_tso_win_divisor> (integer; default: 3; since Linux 2.6.9)"
16570 #. type: Plain text
16571 #: build/C/man7/tcp.7:780
16573 "This parameter controls what percentage of the congestion window can be "
16574 "consumed by a single TCP Segmentation Offload (TSO) frame. The setting of "
16575 "this parameter is a tradeoff between burstiness and building larger TSO "
16580 #: build/C/man7/tcp.7:780
16582 msgid "I<tcp_tw_recycle> (Boolean; default: disabled; since Linux 2.4)"
16587 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
16588 #. type: Plain text
16589 #: build/C/man7/tcp.7:790
16591 "Enable fast recycling of TIME_WAIT sockets. Enabling this option is not "
16592 "recommended for devices communicating with the general Internet or using NAT "
16593 "(Network Address Translation). Since some NAT gateways pass through IP "
16594 "timestamp values, one IP can appear to have non-increasing timestamps. See "
16595 "RFC 1323 (PAWS), RFC 6191."
16599 #: build/C/man7/tcp.7:790
16601 msgid "I<tcp_tw_reuse> (Boolean; default: disabled; since Linux 2.4.19/2.6)"
16604 #. Since 2.4.19/2.5.43
16606 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
16607 #. type: Plain text
16608 #: build/C/man7/tcp.7:798
16610 "Allow to reuse TIME_WAIT sockets for new connections when it is safe from "
16611 "protocol viewpoint. It should not be changed without advice/request of "
16612 "technical experts."
16616 #: build/C/man7/tcp.7:798
16618 msgid "I<tcp_vegas_cong_avoid> (Boolean; default: disabled; Linux 2.2 to 2.6.13)"
16621 #. Since 2.1.8; removed in 2.6.13
16623 #. The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
16624 #. type: Plain text
16625 #: build/C/man7/tcp.7:809
16627 "Enable TCP Vegas congestion avoidance algorithm. TCP Vegas is a sender-side "
16628 "only change to TCP that anticipates the onset of congestion by estimating "
16629 "the bandwidth. TCP Vegas adjusts the sending rate by modifying the "
16630 "congestion window. TCP Vegas should provide less packet loss, but it is not "
16631 "as aggressive as TCP Reno."
16635 #: build/C/man7/tcp.7:809
16637 msgid "I<tcp_westwood> (Boolean; default: disabled; Linux 2.4.26/2.6.3 to 2.6.13)"
16640 #. type: Plain text
16641 #: build/C/man7/tcp.7:821
16643 "Enable TCP Westwood+ congestion control algorithm. TCP Westwood+ is a "
16644 "sender-side only modification of the TCP Reno protocol stack that optimizes "
16645 "the performance of TCP congestion control. It is based on end-to-end "
16646 "bandwidth estimation to set congestion window and slow start threshold after "
16647 "a congestion episode. Using this estimation, TCP Westwood+ adaptively sets "
16648 "a slow start threshold and a congestion window which takes into account the "
16649 "bandwidth used at the time congestion is experienced. TCP Westwood+ "
16650 "significantly increases fairness with respect to TCP Reno in wired networks "
16651 "and throughput over wireless links."
16655 #: build/C/man7/tcp.7:821
16657 msgid "I<tcp_window_scaling> (Boolean; default: enabled; since Linux 2.2)"
16661 #. type: Plain text
16662 #: build/C/man7/tcp.7:835
16664 "Enable RFC\\ 1323 TCP window scaling. This feature allows the use of a "
16665 "large window (E<gt> 64K) on a TCP connection, should the other end support "
16666 "it. Normally, the 16 bit window length field in the TCP header limits the "
16667 "window size to less than 64K bytes. If larger windows are desired, "
16668 "applications can increase the size of their socket buffers and the window "
16669 "scaling option will be employed. If I<tcp_window_scaling> is disabled, TCP "
16670 "will not negotiate the use of window scaling with the other end during "
16671 "connection setup."
16675 #: build/C/man7/tcp.7:835
16677 msgid "I<tcp_wmem> (since Linux 2.4)"
16680 #. Since 2.4.0-test7
16681 #. type: Plain text
16682 #: build/C/man7/tcp.7:843
16684 "This is a vector of 3 integers: [min, default, max]. These parameters are "
16685 "used by TCP to regulate send buffer sizes. TCP dynamically adjusts the size "
16686 "of the send buffer from the default values listed below, in the range of "
16687 "these values, depending on memory available."
16690 #. type: Plain text
16691 #: build/C/man7/tcp.7:854
16693 "Minimum size of the send buffer used by each TCP socket. The default value "
16694 "is the system page size. (On Linux 2.4, the default value is 4K bytes.) "
16695 "This value is used to ensure that in memory pressure mode, allocations below "
16696 "this size will still succeed. This is not used to bound the size of the "
16697 "send buffer declared using B<SO_SNDBUF> on a socket."
16700 #. True in Linux 2.4 and 2.6
16701 #. type: Plain text
16702 #: build/C/man7/tcp.7:868
16704 "The default size of the send buffer for a TCP socket. This value overwrites "
16705 "the initial default buffer size from the generic global "
16706 "I</proc/sys/net/core/wmem_default> defined for all protocols. The default "
16707 "value is 16K bytes. If larger send buffer sizes are desired, this value "
16708 "should be increased (to affect all sockets). To employ large TCP windows, "
16709 "the I</proc/sys/net/ipv4/tcp_window_scaling> must be set to a nonzero value "
16713 #. type: Plain text
16714 #: build/C/man7/tcp.7:877
16716 "The maximum size of the send buffer used by each TCP socket. This value "
16717 "does not override the value in I</proc/sys/net/core/wmem_max>. This is not "
16718 "used to limit the size of the send buffer declared using B<SO_SNDBUF> on a "
16719 "socket. The default value is calculated using the formula"
16722 #. type: Plain text
16723 #: build/C/man7/tcp.7:879
16725 msgid " max(65536, min(4MB, I<tcp_mem>[1]*PAGE_SIZE/128))\n"
16728 #. type: Plain text
16729 #: build/C/man7/tcp.7:882
16731 "(On Linux 2.4, the default value is 128K bytes, lowered 64K depending on "
16732 "low-memory systems.)"
16736 #: build/C/man7/tcp.7:883
16739 "I<tcp_workaround_signed_windows> (Boolean; default: disabled; since Linux "
16743 #. type: Plain text
16744 #: build/C/man7/tcp.7:889
16746 "If enabled, assume that no receipt of a window-scaling option means that the "
16747 "remote TCP is broken and treats the window as a signed quantity. If "
16748 "disabled, assume that the remote TCP is not broken even if we do not receive "
16749 "a window scaling option from it."
16752 #. or SOL_TCP on Linux
16753 #. type: Plain text
16754 #: build/C/man7/tcp.7:907
16756 "To set or get a TCP socket option, call B<getsockopt>(2) to read or "
16757 "B<setsockopt>(2) to write the option with the option level argument set to "
16758 "B<IPPROTO_TCP>. Unless otherwise noted, I<optval> is a pointer to an "
16759 "I<int>. In addition, most B<IPPROTO_IP> socket options are valid on TCP "
16760 "sockets. For more information see B<ip>(7)."
16764 #: build/C/man7/tcp.7:907
16766 msgid "B<TCP_CONGESTION> (since Linux 2.6.13)"
16769 #. commit 5f8ef48d240963093451bcf83df89f1a1364f51d
16770 #. Author: Stephen Hemminger <shemminger@osdl.org>
16771 #. type: Plain text
16772 #: build/C/man7/tcp.7:923
16774 "The argument for this option is a string. This option allows the caller to "
16775 "set the TCP congestion control algorithm to be used, on a per-socket basis. "
16776 "Unprivileged processes are restricted to choosing one of the algorithms in "
16777 "I<tcp_allowed_congestion_control> (described above). Privileged processes "
16778 "(B<CAP_NET_ADMIN>) can choose from any of the available congestion-control "
16779 "algorithms (see the description of I<tcp_available_congestion_control> "
16784 #: build/C/man7/tcp.7:923
16786 msgid "B<TCP_CORK> (since Linux 2.2)"
16789 #. precisely: since 2.1.127
16790 #. type: Plain text
16791 #: build/C/man7/tcp.7:939
16793 "If set, don't send out partial frames. All queued partial frames are sent "
16794 "when the option is cleared again. This is useful for prepending headers "
16795 "before calling B<sendfile>(2), or for throughput optimization. As currently "
16796 "implemented, there is a 200 millisecond ceiling on the time for which output "
16797 "is corked by B<TCP_CORK>. If this ceiling is reached, then queued data is "
16798 "automatically transmitted. This option can be combined with B<TCP_NODELAY> "
16799 "only since Linux 2.5.71. This option should not be used in code intended to "
16804 #: build/C/man7/tcp.7:939
16806 msgid "B<TCP_DEFER_ACCEPT> (since Linux 2.4)"
16809 #. Precisely: since 2.3.38
16810 #. Useful references:
16811 #. http://www.techrepublic.com/article/take-advantage-of-tcp-ip-options-to-optimize-data-transmission/
16812 #. http://unix.stackexchange.com/questions/94104/real-world-use-of-tcp-defer-accept
16813 #. type: Plain text
16814 #: build/C/man7/tcp.7:950
16816 "Allow a listener to be awakened only when data arrives on the socket. Takes "
16817 "an integer value (seconds), this can bound the maximum number of attempts "
16818 "TCP will make to complete the connection. This option should not be used in "
16819 "code intended to be portable."
16823 #: build/C/man7/tcp.7:950
16825 msgid "B<TCP_INFO> (since Linux 2.4)"
16828 #. type: Plain text
16829 #: build/C/man7/tcp.7:956
16831 "Used to collect information about this socket. The kernel returns a "
16832 "I<struct tcp_info> as defined in the file I</usr/include/linux/tcp.h>. This "
16833 "option should not be used in code intended to be portable."
16837 #: build/C/man7/tcp.7:956
16839 msgid "B<TCP_KEEPCNT> (since Linux 2.4)"
16842 #. Precisely: since 2.3.18
16843 #. type: Plain text
16844 #: build/C/man7/tcp.7:963
16846 "The maximum number of keepalive probes TCP should send before dropping the "
16847 "connection. This option should not be used in code intended to be portable."
16851 #: build/C/man7/tcp.7:963
16853 msgid "B<TCP_KEEPIDLE> (since Linux 2.4)"
16856 #. Precisely: since 2.3.18
16857 #. type: Plain text
16858 #: build/C/man7/tcp.7:972
16860 "The time (in seconds) the connection needs to remain idle before TCP starts "
16861 "sending keepalive probes, if the socket option B<SO_KEEPALIVE> has been set "
16862 "on this socket. This option should not be used in code intended to be "
16867 #: build/C/man7/tcp.7:972
16869 msgid "B<TCP_KEEPINTVL> (since Linux 2.4)"
16872 #. Precisely: since 2.3.18
16873 #. type: Plain text
16874 #: build/C/man7/tcp.7:977
16876 "The time (in seconds) between individual keepalive probes. This option "
16877 "should not be used in code intended to be portable."
16881 #: build/C/man7/tcp.7:977
16883 msgid "B<TCP_LINGER2> (since Linux 2.4)"
16886 #. Precisely: since 2.3.41
16887 #. type: Plain text
16888 #: build/C/man7/tcp.7:989
16890 "The lifetime of orphaned FIN_WAIT2 state sockets. This option can be used "
16891 "to override the system-wide setting in the file "
16892 "I</proc/sys/net/ipv4/tcp_fin_timeout> for this socket. This is not to be "
16893 "confused with the B<socket>(7) level option B<SO_LINGER>. This option "
16894 "should not be used in code intended to be portable."
16898 #: build/C/man7/tcp.7:989
16900 msgid "B<TCP_MAXSEG>"
16903 #. Present in Linux 1.0
16904 #. type: Plain text
16905 #: build/C/man7/tcp.7:999
16907 "The maximum segment size for outgoing TCP packets. In Linux 2.2 and "
16908 "earlier, and in Linux 2.6.28 and later, if this option is set before "
16909 "connection establishment, it also changes the MSS value announced to the "
16910 "other end in the initial packet. Values greater than the (eventual) "
16911 "interface MTU have no effect. TCP will also impose its minimum and maximum "
16912 "bounds over the value provided."
16916 #: build/C/man7/tcp.7:999
16918 msgid "B<TCP_NODELAY>"
16921 #. Present in Linux 1.0
16922 #. type: Plain text
16923 #: build/C/man7/tcp.7:1016
16925 "If set, disable the Nagle algorithm. This means that segments are always "
16926 "sent as soon as possible, even if there is only a small amount of data. "
16927 "When not set, data is buffered until there is a sufficient amount to send "
16928 "out, thereby avoiding the frequent sending of small packets, which results "
16929 "in poor utilization of the network. This option is overridden by "
16930 "B<TCP_CORK>; however, setting this option forces an explicit flush of "
16931 "pending output, even if B<TCP_CORK> is currently set."
16935 #: build/C/man7/tcp.7:1016
16937 msgid "B<TCP_QUICKACK> (since Linux 2.4.4)"
16940 #. type: Plain text
16941 #: build/C/man7/tcp.7:1031
16943 "Enable quickack mode if set or disable quickack mode if cleared. In "
16944 "quickack mode, acks are sent immediately, rather than delayed if needed in "
16945 "accordance to normal TCP operation. This flag is not permanent, it only "
16946 "enables a switch to or from quickack mode. Subsequent operation of the TCP "
16947 "protocol will once again enter/leave quickack mode depending on internal "
16948 "protocol processing and factors such as delayed ack timeouts occurring and "
16949 "data transfer. This option should not be used in code intended to be "
16954 #: build/C/man7/tcp.7:1031
16956 msgid "B<TCP_SYNCNT> (since Linux 2.4)"
16959 #. Precisely: since 2.3.18
16960 #. type: Plain text
16961 #: build/C/man7/tcp.7:1038
16963 "Set the number of SYN retransmits that TCP should send before aborting the "
16964 "attempt to connect. It cannot exceed 255. This option should not be used "
16965 "in code intended to be portable."
16969 #: build/C/man7/tcp.7:1038
16971 msgid "B<TCP_USER_TIMEOUT> (since Linux 2.6.37)"
16974 #. commit dca43c75e7e545694a9dd6288553f55c53e2a3a3
16975 #. Author: Jerry Chu <hkchu@google.com>
16976 #. The following text taken nearly verbatim from Jerry Chu's (excellent)
16978 #. type: Plain text
16979 #: build/C/man7/tcp.7:1056
16981 "This option takes an I<unsigned int> as an argument. When the value is "
16982 "greater than 0, it specifies the maximum amount of time in milliseconds that "
16983 "transmitted data may remain unacknowledged before TCP will forcibly close "
16984 "the corresponding connection and return B<ETIMEDOUT> to the application. If "
16985 "the option value is specified as 0, TCP will to use the system default."
16988 #. type: Plain text
16989 #: build/C/man7/tcp.7:1063
16991 "Increasing user timeouts allows a TCP connection to survive extended periods "
16992 "without end-to-end connectivity. Decreasing user timeouts allows "
16993 "applications to \"fail fast\", if so desired. Otherwise, failure may take "
16994 "up to 20 minutes with the current system defaults in a normal WAN "
16998 #. type: Plain text
16999 #: build/C/man7/tcp.7:1073
17001 "This option can be set during any state of a TCP connection, but is only "
17002 "effective during the synchronized states of a connection (ESTABLISHED, "
17003 "FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, and LAST-ACK). Moreover, when "
17004 "used with the TCP keepalive (B<SO_KEEPALIVE>) option, B<TCP_USER_TIMEOUT> "
17005 "will override keepalive to determine when to close a connection due to "
17006 "keepalive failure."
17009 #. type: Plain text
17010 #: build/C/man7/tcp.7:1076
17012 "The option has no effect on when TCP retransmits a packet, nor when a "
17013 "keepalive probe is sent."
17016 #. type: Plain text
17017 #: build/C/man7/tcp.7:1080
17019 "This option, like many others, will be inherited by the socket returned by "
17020 "B<accept>(2), if it was set on the listening socket."
17023 #. type: Plain text
17024 #: build/C/man7/tcp.7:1083
17026 "Further details on the user timeout feature can be found in RFC\\ 793 and "
17027 "RFC\\ 5482 (\"TCP User Timeout Option\")."
17031 #: build/C/man7/tcp.7:1083
17033 msgid "B<TCP_WINDOW_CLAMP> (since Linux 2.4)"
17036 #. Precisely: since 2.3.41
17037 #. type: Plain text
17038 #: build/C/man7/tcp.7:1090
17040 "Bound the size of the advertised window to this value. The kernel imposes a "
17041 "minimum size of SOCK_MIN_RCVBUF/2. This option should not be used in code "
17042 "intended to be portable."
17046 #: build/C/man7/tcp.7:1090 build/C/man7/unix.7:260
17048 msgid "Sockets API"
17051 #. type: Plain text
17052 #: build/C/man7/tcp.7:1099
17054 "TCP provides limited support for out-of-band data, in the form of (a single "
17055 "byte of) urgent data. In Linux this means if the other end sends newer "
17056 "out-of-band data the older urgent data is inserted as normal data into the "
17057 "stream (even when B<SO_OOBINLINE> is not set). This differs from BSD-based "
17061 #. type: Plain text
17062 #: build/C/man7/tcp.7:1106
17064 "Linux uses the BSD compatible interpretation of the urgent pointer field by "
17065 "default. This violates RFC\\ 1122, but is required for interoperability "
17066 "with other stacks. It can be changed via I</proc/sys/net/ipv4/tcp_stdurg>."
17069 #. type: Plain text
17070 #: build/C/man7/tcp.7:1111
17072 "It is possible to peek at out-of-band data using the B<recv>(2) B<MSG_PEEK> "
17076 #. type: Plain text
17077 #: build/C/man7/tcp.7:1127
17079 "Since version 2.4, Linux supports the use of B<MSG_TRUNC> in the I<flags> "
17080 "argument of B<recv>(2) (and B<recvmsg>(2)). This flag causes the received "
17081 "bytes of data to be discarded, rather than passed back in a caller-supplied "
17082 "buffer. Since Linux 2.4.4, B<MSG_TRUNC> also has this effect when used in "
17083 "conjunction with B<MSG_OOB> to receive out-of-band data."
17086 #. type: Plain text
17087 #: build/C/man7/tcp.7:1133 build/C/man7/unix.7:373
17089 "The following B<ioctl>(2) calls return information in I<value>. The "
17090 "correct syntax is:"
17093 #. type: Plain text
17094 #: build/C/man7/tcp.7:1138
17097 "B<int>I< value>B<;>\n"
17098 "I<error>B< = ioctl(>I<tcp_socket>B<, >I<ioctl_type>B<, &>I<value>B<);>\n"
17101 #. type: Plain text
17102 #: build/C/man7/tcp.7:1143
17103 msgid "I<ioctl_type> is one of the following:"
17107 #: build/C/man7/tcp.7:1143 build/C/man7/unix.7:383
17112 #. FIXME . http://sources.redhat.com/bugzilla/show_bug.cgi?id=12002,
17113 #. filed 2010-09-10, may cause SIOCINQ to be defined in glibc headers
17114 #. SIOCOUTQ also has an effect for UNIX domain sockets, but not
17115 #. quite what userland might expect. It seems to return the number
17116 #. of bytes allocated for buffers containing pending output.
17117 #. That number is normally larger than the number of bytes of pending
17118 #. output. Since this info is, from userland's point of view, imprecise,
17119 #. and it may well change, probably best not to document this now.
17120 #. type: Plain text
17121 #: build/C/man7/tcp.7:1159 build/C/man7/unix.7:405
17123 "Returns the amount of queued unread data in the receive buffer. The socket "
17124 "must not be in LISTEN state, otherwise an error (B<EINVAL>) is returned. "
17125 "B<SIOCINQ> is defined in I<E<lt>linux/sockios.hE<gt>>. Alternatively, you "
17126 "can use the synonymous B<FIONREAD>, defined in I<E<lt>sys/ioctl.hE<gt>>."
17130 #: build/C/man7/tcp.7:1159
17132 msgid "B<SIOCATMARK>"
17135 #. type: Plain text
17136 #: build/C/man7/tcp.7:1164
17138 "Returns true (i.e., I<value> is nonzero) if the inbound data stream is at "
17142 #. type: Plain text
17143 #: build/C/man7/tcp.7:1180
17145 "If the B<SO_OOBINLINE> socket option is set, and B<SIOCATMARK> returns true, "
17146 "then the next read from the socket will return the urgent data. If the "
17147 "B<SO_OOBINLINE> socket option is not set, and B<SIOCATMARK> returns true, "
17148 "then the next read from the socket will return the bytes following the "
17149 "urgent data (to actually read the urgent data requires the B<recv(MSG_OOB)> "
17153 #. type: Plain text
17154 #: build/C/man7/tcp.7:1194
17156 "Note that a read never reads across the urgent mark. If an application is "
17157 "informed of the presence of urgent data via B<select>(2) (using the "
17158 "I<exceptfds> argument) or through delivery of a B<SIGURG> signal, then it "
17159 "can advance up to the mark using a loop which repeatedly tests B<SIOCATMARK> "
17160 "and performs a read (requesting any number of bytes) as long as "
17161 "B<SIOCATMARK> returns false."
17165 #: build/C/man7/tcp.7:1194
17167 msgid "B<SIOCOUTQ>"
17170 #. FIXME . http://sources.redhat.com/bugzilla/show_bug.cgi?id=12002,
17171 #. filed 2010-09-10, may cause SIOCOUTQ to be defined in glibc headers
17172 #. type: Plain text
17173 #: build/C/man7/tcp.7:1210
17175 "Returns the amount of unsent data in the socket send queue. The socket must "
17176 "not be in LISTEN state, otherwise an error (B<EINVAL>) is returned. "
17177 "B<SIOCOUTQ> is defined in I<E<lt>linux/sockios.hE<gt>>. Alternatively, you "
17178 "can use the synonymous B<TIOCOUTQ>, defined in I<E<lt>sys/ioctl.hE<gt>>."
17181 #. type: Plain text
17182 #: build/C/man7/tcp.7:1215
17184 "When a network error occurs, TCP tries to resend the packet. If it doesn't "
17185 "succeed after some time, either B<ETIMEDOUT> or the last received error on "
17186 "this connection is reported."
17189 #. type: Plain text
17190 #: build/C/man7/tcp.7:1226
17192 "Some applications require a quicker error notification. This can be enabled "
17193 "with the B<IPPROTO_IP> level B<IP_RECVERR> socket option. When this option "
17194 "is enabled, all incoming errors are immediately passed to the user program. "
17195 "Use this option with care \\(em it makes TCP less tolerant to routing "
17196 "changes and other normal network conditions."
17200 #: build/C/man7/tcp.7:1227
17202 msgid "B<EAFNOTSUPPORT>"
17205 #. type: Plain text
17206 #: build/C/man7/tcp.7:1233
17207 msgid "Passed socket address type in I<sin_family> was not B<AF_INET>."
17210 #. type: Plain text
17211 #: build/C/man7/tcp.7:1237
17213 "The other end closed the socket unexpectedly or a read is executed on a shut "
17218 #: build/C/man7/tcp.7:1237
17220 msgid "B<ETIMEDOUT>"
17223 #. type: Plain text
17224 #: build/C/man7/tcp.7:1240
17225 msgid "The other end didn't acknowledge retransmitted data after some time."
17228 #. type: Plain text
17229 #: build/C/man7/tcp.7:1244
17231 "Any errors defined for B<ip>(7) or the generic socket layer may also be "
17232 "returned for TCP."
17235 #. type: Plain text
17236 #: build/C/man7/tcp.7:1251
17238 "Support for Explicit Congestion Notification, zero-copy B<sendfile>(2), "
17239 "reordering support and some SACK extensions (DSACK) were introduced in 2.4. "
17240 "Support for forward acknowledgement (FACK), TIME_WAIT recycling, and "
17241 "per-connection keepalive socket options were introduced in 2.3."
17244 #. type: Plain text
17245 #: build/C/man7/tcp.7:1253
17246 msgid "Not all errors are documented."
17249 #. Only a single Linux kernel version is described
17250 #. Info for 2.2 was lost. Should be added again,
17251 #. or put into a separate page.
17253 #. This man page was originally written by Andi Kleen.
17254 #. It was updated for 2.4 by Nivedita Singhvi with input from
17255 #. Alexey Kuznetsov's Documentation/networking/ip-sysctl.txt
17257 #. type: Plain text
17258 #: build/C/man7/tcp.7:1263
17259 msgid "IPv6 is not described."
17262 #. type: Plain text
17263 #: build/C/man7/tcp.7:1275
17265 "B<accept>(2), B<bind>(2), B<connect>(2), B<getsockopt>(2), B<listen>(2), "
17266 "B<recvmsg>(2), B<sendfile>(2), B<sendmsg>(2), B<socket>(2), B<ip>(7), "
17270 #. type: Plain text
17271 #: build/C/man7/tcp.7:1277
17272 msgid "RFC\\ 793 for the TCP specification."
17275 #. type: Plain text
17276 #: build/C/man7/tcp.7:1279
17278 "RFC\\ 1122 for the TCP requirements and a description of the Nagle "
17282 #. type: Plain text
17283 #: build/C/man7/tcp.7:1281
17284 msgid "RFC\\ 1323 for TCP timestamp and window scaling options."
17287 #. type: Plain text
17288 #: build/C/man7/tcp.7:1283
17289 msgid "RFC\\ 1337 for a description of TIME_WAIT assassination hazards."
17292 #. type: Plain text
17293 #: build/C/man7/tcp.7:1285
17294 msgid "RFC\\ 3168 for a description of Explicit Congestion Notification."
17297 #. type: Plain text
17298 #: build/C/man7/tcp.7:1287
17299 msgid "RFC\\ 2581 for TCP congestion control algorithms."
17302 #. type: Plain text
17303 #: build/C/man7/tcp.7:1288
17304 msgid "RFC\\ 2018 and RFC\\ 2883 for SACK and extensions to SACK."
17308 #: build/C/man7/udp.7:12
17314 #: build/C/man7/udp.7:12
17319 #. type: Plain text
17320 #: build/C/man7/udp.7:15
17321 msgid "udp - User Datagram Protocol for IPv4"
17324 #. type: Plain text
17325 #: build/C/man7/udp.7:21
17326 msgid "B<#include E<lt>netinet/udp.hE<gt>>"
17329 #. type: Plain text
17330 #: build/C/man7/udp.7:23
17331 msgid "B<udp_socket = socket(AF_INET, SOCK_DGRAM, 0);>"
17334 #. type: Plain text
17335 #: build/C/man7/udp.7:29
17337 "This is an implementation of the User Datagram Protocol described in RFC\\ "
17338 "768. It implements a connectionless, unreliable datagram packet service. "
17339 "Packets may be reordered or duplicated before they arrive. UDP generates "
17340 "and checks checksums to catch transmission errors."
17343 #. type: Plain text
17344 #: build/C/man7/udp.7:58
17346 "When a UDP socket is created, its local and remote addresses are "
17347 "unspecified. Datagrams can be sent immediately using B<sendto>(2) or "
17348 "B<sendmsg>(2) with a valid destination address as an argument. When "
17349 "B<connect>(2) is called on the socket, the default destination address is "
17350 "set and datagrams can now be sent using B<send>(2) or B<write>(2) without "
17351 "specifying a destination address. It is still possible to send to other "
17352 "destinations by passing an address to B<sendto>(2) or B<sendmsg>(2). In "
17353 "order to receive packets, the socket can be bound to a local address first "
17354 "by using B<bind>(2). Otherwise, the socket layer will automatically assign "
17355 "a free local port out of the range defined by "
17356 "I</proc/sys/net/ipv4/ip_local_port_range> and bind the socket to "
17360 #. type: Plain text
17361 #: build/C/man7/udp.7:66
17363 "All receive operations return only one packet. When the packet is smaller "
17364 "than the passed buffer, only that much data is returned; when it is bigger, "
17365 "the packet is truncated and the B<MSG_TRUNC> flag is set. B<MSG_WAITALL> is "
17369 #. type: Plain text
17370 #: build/C/man7/udp.7:75
17372 "IP options may be sent or received using the socket options described in "
17373 "B<ip>(7). They are processed by the kernel only when the appropriate "
17374 "I</proc> parameter is enabled (but still passed to the user even when it is "
17375 "turned off). See B<ip>(7)."
17378 #. type: Plain text
17379 #: build/C/man7/udp.7:80
17381 "When the B<MSG_DONTROUTE> flag is set on sending, the destination address "
17382 "must refer to a local interface address and the packet is sent only to that "
17386 #. type: Plain text
17387 #: build/C/man7/udp.7:98
17389 "By default, Linux UDP does path MTU (Maximum Transmission Unit) discovery. "
17390 "This means the kernel will keep track of the MTU to a specific target IP "
17391 "address and return B<EMSGSIZE> when a UDP packet write exceeds it. When "
17392 "this happens, the application should decrease the packet size. Path MTU "
17393 "discovery can be also turned off using the B<IP_MTU_DISCOVER> socket option "
17394 "or the I</proc/sys/net/ipv4/ip_no_pmtu_disc> file; see B<ip>(7) for "
17395 "details. When turned off, UDP will fragment outgoing UDP packets that "
17396 "exceed the interface MTU. However, disabling it is not recommended for "
17397 "performance and reliability reasons."
17400 #. type: Plain text
17401 #: build/C/man7/udp.7:103
17402 msgid "UDP uses the IPv4 I<sockaddr_in> address format described in B<ip>(7)."
17405 #. type: Plain text
17406 #: build/C/man7/udp.7:114
17408 "All fatal errors will be passed to the user as an error return even when the "
17409 "socket is not connected. This includes asynchronous errors received from "
17410 "the network. You may get an error for an earlier packet that was sent on "
17411 "the same socket. This behavior differs from many other BSD socket "
17412 "implementations which don't pass any errors unless the socket is connected. "
17413 "Linux's behavior is mandated by B<RFC\\ 1122>."
17416 #. type: Plain text
17417 #: build/C/man7/udp.7:128
17419 "For compatibility with legacy code, in Linux 2.0 and 2.2 it was possible to "
17420 "set the B<SO_BSDCOMPAT> B<SOL_SOCKET> option to receive remote errors only "
17421 "when the socket has been connected (except for B<EPROTO> and B<EMSGSIZE>). "
17422 "Locally generated errors are always passed. Support for this socket option "
17423 "was removed in later kernels; see B<socket>(7) for further information."
17426 #. type: Plain text
17427 #: build/C/man7/udp.7:137
17429 "When the B<IP_RECVERR> option is enabled, all errors are stored in the "
17430 "socket error queue, and can be received by B<recvmsg>(2) with the "
17431 "B<MSG_ERRQUEUE> flag set."
17434 #. type: Plain text
17435 #: build/C/man7/udp.7:140
17437 "System-wide UDP parameter settings can be accessed by files in the directory "
17438 "I</proc/sys/net/ipv4/>."
17442 #: build/C/man7/udp.7:140
17444 msgid "I<udp_mem> (since Linux 2.6.25)"
17447 #. type: Plain text
17448 #: build/C/man7/udp.7:144
17450 "This is a vector of three integers governing the number of pages allowed for "
17451 "queueing by all UDP sockets."
17454 #. type: Plain text
17455 #: build/C/man7/udp.7:151
17457 "Below this number of pages, UDP is not bothered about its memory appetite. "
17458 "When the amount of memory allocated by UDP exceeds this number, UDP starts "
17459 "to moderate memory usage."
17462 #. type: Plain text
17463 #: build/C/man7/udp.7:157
17465 "This value was introduced to follow the format of I<tcp_mem> (see "
17469 #. type: Plain text
17470 #: build/C/man7/udp.7:160
17471 msgid "Number of pages allowed for queueing by all UDP sockets."
17474 #. type: Plain text
17475 #: build/C/man7/udp.7:164
17477 "Defaults values for these three items are calculated at boot time from the "
17478 "amount of available memory."
17482 #: build/C/man7/udp.7:164
17484 msgid "I<udp_rmem_min> (integer; default value: PAGE_SIZE; since Linux 2.6.25)"
17487 #. type: Plain text
17488 #: build/C/man7/udp.7:171
17490 "Minimal size, in bytes, of receive buffers used by UDP sockets in "
17491 "moderation. Each UDP socket is able to use the size for receiving data, "
17492 "even if total pages of UDP sockets exceed I<udp_mem> pressure."
17496 #: build/C/man7/udp.7:171
17498 msgid "I<udp_wmem_min> (integer; default value: PAGE_SIZE; since Linux 2.6.25)"
17501 #. type: Plain text
17502 #: build/C/man7/udp.7:178
17504 "Minimal size, in bytes, of send buffer used by UDP sockets in moderation. "
17505 "Each UDP socket is able to use the size for sending data, even if total "
17506 "pages of UDP sockets exceed I<udp_mem> pressure."
17509 #. type: Plain text
17510 #: build/C/man7/udp.7:189
17512 "To set or get a UDP socket option, call B<getsockopt>(2) to read or "
17513 "B<setsockopt>(2) to write the option with the option level argument set to "
17514 "B<IPPROTO_UDP>. Unless otherwise noted, I<optval> is a pointer to an "
17519 #: build/C/man7/udp.7:189
17521 msgid "B<UDP_CORK> (since Linux 2.5.44)"
17524 #. FIXME document UDP_ENCAP (new in kernel 2.5.67)
17525 #. From include/linux/udp.h:
17526 #. /* UDP encapsulation types */
17527 #. #define UDP_ENCAP_ESPINUDP_NON_IKE 1 /* draft-ietf-ipsec-nat-t-ike-00/01 */
17528 #. #define UDP_ENCAP_ESPINUDP 2 /* draft-ietf-ipsec-udp-encaps-06 */
17529 #. #define UDP_ENCAP_L2TPINUDP 3 /* rfc2661 */
17530 #. type: Plain text
17531 #: build/C/man7/udp.7:202
17533 "If this option is enabled, then all data output on this socket is "
17534 "accumulated into a single datagram that is transmitted when the option is "
17535 "disabled. This option should not be used in code intended to be portable."
17538 #. type: Plain text
17539 #: build/C/man7/udp.7:206
17540 msgid "These ioctls can be accessed using B<ioctl>(2). The correct syntax is:"
17543 #. type: Plain text
17544 #: build/C/man7/udp.7:211
17547 "B<int>I< value>B<;>\n"
17548 "I<error>B< = ioctl(>I<udp_socket>B<, >I<ioctl_type>B<, &>I<value>B<);>\n"
17552 #: build/C/man7/udp.7:213
17554 msgid "B<FIONREAD> (B<SIOCINQ>)"
17557 #. See http://www.securiteam.com/unixfocus/5KP0I15IKO.html
17558 #. "GNUnet DoS (UDP Socket Unreachable)", 14 May 2006
17559 #. type: Plain text
17560 #: build/C/man7/udp.7:231
17562 "Gets a pointer to an integer as argument. Returns the size of the next "
17563 "pending datagram in the integer in bytes, or 0 when no datagram is pending. "
17564 "B<Warning:> Using B<FIONREAD>, it is impossible to distinguish the case "
17565 "where no datagram is pending from the case where the next pending datagram "
17566 "contains zero bytes of data. It is safer to use B<select>(2), B<poll>(2), "
17567 "or B<epoll>(7) to distinguish these cases."
17571 #: build/C/man7/udp.7:231
17573 msgid "B<TIOCOUTQ> (B<SIOCOUTQ>)"
17576 #. type: Plain text
17577 #: build/C/man7/udp.7:235
17579 "Returns the number of data bytes in the local send queue. Only supported "
17580 "with Linux 2.4 and above."
17583 #. type: Plain text
17584 #: build/C/man7/udp.7:241
17586 "In addition, all ioctls documented in B<ip>(7) and B<socket>(7) are "
17590 #. type: Plain text
17591 #: build/C/man7/udp.7:247
17593 "All errors documented for B<socket>(7) or B<ip>(7) may be returned by a "
17594 "send or receive on a UDP socket."
17598 #: build/C/man7/udp.7:247 build/C/man7/unix.7:410
17600 msgid "B<ECONNREFUSED>"
17603 #. type: Plain text
17604 #: build/C/man7/udp.7:251
17606 "No receiver was associated with the destination address. This might be "
17607 "caused by a previous packet sent over the socket."
17611 #. This man page was written by Andi Kleen.
17612 #. type: Plain text
17613 #: build/C/man7/udp.7:256
17614 msgid "B<IP_RECVERR> is a new feature in Linux 2.2."
17617 #. type: Plain text
17618 #: build/C/man7/udp.7:261
17619 msgid "B<ip>(7), B<raw>(7), B<socket>(7), B<udplite>(7)"
17622 #. type: Plain text
17623 #: build/C/man7/udp.7:263
17624 msgid "RFC\\ 768 for the User Datagram Protocol."
17627 #. type: Plain text
17628 #: build/C/man7/udp.7:265
17629 msgid "RFC\\ 1122 for the host requirements."
17632 #. type: Plain text
17633 #: build/C/man7/udp.7:266
17634 msgid "RFC\\ 1191 for a description of path MTU discovery."
17638 #: build/C/man7/udplite.7:27
17643 #. type: Plain text
17644 #: build/C/man7/udplite.7:30
17645 msgid "udplite - Lightweight User Datagram Protocol"
17648 #. type: Plain text
17649 #: build/C/man7/udplite.7:38
17650 msgid "B<sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDPLITE);>"
17653 #. type: Plain text
17654 #: build/C/man7/udplite.7:41
17656 "This is an implementation of the Lightweight User Datagram Protocol "
17657 "(UDP-Lite), as described in RFC\\ 3828."
17660 #. type: Plain text
17661 #: build/C/man7/udplite.7:47
17663 "UDP-Lite is an extension of UDP (RFC\\ 768) to support variable-length "
17664 "checksums. This has advantages for some types of multimedia transport that "
17665 "may be able to make use of slightly damaged datagrams, rather than having "
17666 "them discarded by lower-layer protocols."
17669 #. type: Plain text
17670 #: build/C/man7/udplite.7:53
17672 "The variable-length checksum coverage is set via a B<setsockopt>(2) "
17673 "option. If this option is not set, the only difference to UDP is in using a "
17674 "different IP protocol identifier (IANA number 136)."
17677 #. type: Plain text
17678 #: build/C/man7/udplite.7:58
17680 "The UDP-Lite implementation is a full extension of B<udp>(7)\\(emthat is, it "
17681 "shares the same API and API behavior, and in addition offers two socket "
17682 "options to control the checksum coverage."
17685 #. type: Plain text
17686 #: build/C/man7/udplite.7:67
17688 "UDP-Litev4 uses the I<sockaddr_in> address format described in B<ip>(7). "
17689 "UDP-Litev6 uses the I<sockaddr_in6> address format described in B<ipv6>(7)."
17692 #. type: Plain text
17693 #: build/C/man7/udplite.7:80
17695 "To set or get a UDP-Lite socket option, call B<getsockopt>(2) to read or "
17696 "B<setsockopt>(2) to write the option with the option level argument set to "
17697 "B<IPPROTO_UDPLITE>. In addition, all B<IPPROTO_UDP> socket options are "
17698 "valid on a UDP-Lite socket. See B<udp>(7) for more information."
17701 #. type: Plain text
17702 #: build/C/man7/udplite.7:82
17703 msgid "The following two options are specific to UDP-Lite."
17707 #: build/C/man7/udplite.7:82
17709 msgid "B<UDPLITE_SEND_CSCOV>"
17712 #. type: Plain text
17713 #: build/C/man7/udplite.7:87
17715 "This option sets the sender checksum coverage and takes an I<int> as "
17716 "argument, with a checksum coverage value in the range 0..2^16-1."
17719 #. type: Plain text
17720 #: build/C/man7/udplite.7:91
17722 "A value of 0 means that the entire datagram is always covered. Values from "
17723 "1-7 are illegal (RFC\\ 3828, 3.1) and are rounded up to the minimum coverage "
17727 #. type: Plain text
17728 #: build/C/man7/udplite.7:97
17730 "With regard to IPv6 jumbograms (RFC\\ 2675), the UDP-Litev6 checksum "
17731 "coverage is limited to the first 2^16-1 octets, as per RFC\\ 3828, 3.5. "
17732 "Higher values are therefore silently truncated to 2^16-1. If in doubt, the "
17733 "current coverage value can always be queried using B<getsockopt>(2)."
17737 #: build/C/man7/udplite.7:97
17739 msgid "B<UDPLITE_RECV_CSCOV>"
17742 #. type: Plain text
17743 #: build/C/man7/udplite.7:108
17745 "This is the receiver-side analogue and uses the same argument format and "
17746 "value range as B<UDPLITE_SEND_CSCOV>. This option is not required to enable "
17747 "traffic with partial checksum coverage. Its function is that of a traffic "
17748 "filter: when enabled, it instructs the kernel to drop all packets which have "
17749 "a coverage I<less> than the specified coverage value."
17752 #. SO_NO_CHECK exists and is supported by UDPv4, but is
17753 #. commented out in socket(7), hence also commented out here
17755 #. Since UDP-Lite mandates checksums, checksumming can not be disabled
17760 #. type: Plain text
17761 #: build/C/man7/udplite.7:121
17763 "When the value of B<UDPLITE_RECV_CSCOV> exceeds the actual packet coverage, "
17764 "incoming packets are silently dropped, but may generate a warning message in "
17768 #. type: Plain text
17769 #: build/C/man7/udplite.7:126
17771 "All errors documented for B<udp>(7) may be returned. UDP-Lite does not add "
17775 #. type: Plain text
17776 #: build/C/man7/udplite.7:129
17777 msgid "I</proc/net/snmp> - basic UDP-Litev4 statistics counters."
17780 #. type: Plain text
17781 #: build/C/man7/udplite.7:132
17782 msgid "I</proc/net/snmp6> - basic UDP-Litev6 statistics counters."
17785 #. type: Plain text
17786 #: build/C/man7/udplite.7:134
17787 msgid "UDP-Litev4/v6 first appeared in Linux 2.6.20."
17790 #. FIXME . remove this section once glibc supports UDP-Lite
17791 #. type: Plain text
17792 #: build/C/man7/udplite.7:137
17793 msgid "Where glibc support is missing, the following definitions are needed:"
17796 #. The following two are defined in the kernel in linux/net/udplite.h
17797 #. type: Plain text
17798 #: build/C/man7/udplite.7:144
17801 "#define IPPROTO_UDPLITE 136\n"
17802 "#define UDPLITE_SEND_CSCOV 10\n"
17803 "#define UDPLITE_RECV_CSCOV 11\n"
17806 #. type: Plain text
17807 #: build/C/man7/udplite.7:151
17808 msgid "B<ip>(7), B<ipv6>(7), B<socket>(7), B<udp>(7)"
17811 #. type: Plain text
17812 #: build/C/man7/udplite.7:153
17813 msgid "RFC\\ 3828 for the Lightweight User Datagram Protocol (UDP-Lite)."
17816 #. type: Plain text
17817 #: build/C/man7/udplite.7:155
17818 msgid "I<Documentation/networking/udplite.txt> in the Linux kernel source tree"
17822 #: build/C/man7/unix.7:20
17827 #. type: Plain text
17828 #: build/C/man7/unix.7:23
17829 msgid "unix - sockets for local interprocess communication"
17832 #. type: Plain text
17833 #: build/C/man7/unix.7:27
17834 msgid "B<#include E<lt>sys/un.hE<gt>>"
17837 #. type: Plain text
17838 #: build/C/man7/unix.7:29
17839 msgid "I<unix_socket>B< = socket(AF_UNIX, type, 0);>"
17842 #. type: Plain text
17843 #: build/C/man7/unix.7:31
17844 msgid "I<error>B< = socketpair(AF_UNIX, type, 0, int *>I<sv>B<);>"
17847 #. type: Plain text
17848 #: build/C/man7/unix.7:42
17850 "The B<AF_UNIX> (also known as B<AF_LOCAL>) socket family is used to "
17851 "communicate between processes on the same machine efficiently. "
17852 "Traditionally, UNIX domain sockets can be either unnamed, or bound to a "
17853 "filesystem pathname (marked as being of type socket). Linux also supports "
17854 "an abstract namespace which is independent of the filesystem."
17857 #. type: Plain text
17858 #: build/C/man7/unix.7:54
17860 "Valid socket types in the UNIX domain are: B<SOCK_STREAM>, for a "
17861 "stream-oriented socket; B<SOCK_DGRAM>, for a datagram-oriented socket that "
17862 "preserves message boundaries (as on most UNIX implementations, UNIX domain "
17863 "datagram sockets are always reliable and don't reorder datagrams); and "
17864 "(since Linux 2.6.4) B<SOCK_SEQPACKET>, for a connection-oriented socket "
17865 "that preserves message boundaries and delivers messages in the order that "
17869 #. type: Plain text
17870 #: build/C/man7/unix.7:57
17872 "UNIX domain sockets support passing file descriptors or process credentials "
17873 "to other processes using ancillary data."
17876 #. type: Plain text
17877 #: build/C/man7/unix.7:59
17878 msgid "A UNIX domain socket address is represented in the following structure:"
17881 #. type: Plain text
17882 #: build/C/man7/unix.7:63
17884 msgid "#define UNIX_PATH_MAX 108\n"
17887 #. type: Plain text
17888 #: build/C/man7/unix.7:68
17891 "struct sockaddr_un {\n"
17892 " sa_family_t sun_family; /* AF_UNIX */\n"
17893 " char sun_path[UNIX_PATH_MAX]; /* pathname */\n"
17897 #. type: Plain text
17898 #: build/C/man7/unix.7:75
17899 msgid "The I<sun_family> field always contains B<AF_UNIX>."
17902 #. type: Plain text
17903 #: build/C/man7/unix.7:91
17905 "Various systems calls (for example, B<bind>(2), B<connect>(2), and "
17906 "B<sendto>(2)) take a I<sockaddr_un> argument as input. Some other system "
17907 "calls (for example, B<getsockname>(2), B<getpeername>(2), B<recvfrom>(2), "
17908 "and B<accept>(2)) return an argument of this type."
17911 #. type: Plain text
17912 #: build/C/man7/unix.7:95
17913 msgid "Three types of address are distinguished in the I<sockaddr_un> structure:"
17916 #. type: Plain text
17917 #: build/C/man7/unix.7:103
17919 "I<pathname>: a UNIX domain socket can be bound to a null-terminated "
17920 "filesystem pathname using B<bind>(2). When the address of a pathname socket "
17921 "is returned (by one of the system calls noted above), its length is"
17924 #. type: Plain text
17925 #: build/C/man7/unix.7:105
17927 msgid " offsetof(struct sockaddr_un, sun_path) + strlen(sun_path) + 1\n"
17930 #. type: Plain text
17931 #: build/C/man7/unix.7:118
17933 "and I<sun_path> contains the null-terminated pathname. (On Linux, the above "
17934 "B<offsetof>() expression equates to the same value as "
17935 "I<sizeof(sa_family_t)>, but some other implementations include other fields "
17936 "before I<sun_path>, so the B<offsetof>() expression more portably describes "
17937 "the size of the address structure.)"
17940 #. type: Plain text
17941 #: build/C/man7/unix.7:120
17942 msgid "For further details of pathname sockets, see below."
17945 #. There is quite some variation across implementations: FreeBSD
17946 #. says the length is 16 bytes, HP-UX 11 says it's zero bytes.
17947 #. type: Plain text
17948 #: build/C/man7/unix.7:136
17950 "I<unnamed>: A stream socket that has not been bound to a pathname using "
17951 "B<bind>(2) has no name. Likewise, the two sockets created by "
17952 "B<socketpair>(2) are unnamed. When the address of an unnamed socket is "
17953 "returned, its length is I<sizeof(sa_family_t)>, and I<sun_path> should not "
17957 #. type: Plain text
17958 #: build/C/man7/unix.7:159
17960 "I<abstract>: an abstract socket address is distinguished (from a pathname "
17961 "socket) by the fact that I<sun_path[0]> is a null byte (\\(aq\\e0\\(aq). "
17962 "The socket's address in this namespace is given by the additional bytes in "
17963 "I<sun_path> that are covered by the specified length of the address "
17964 "structure. (Null bytes in the name have no special significance.) The name "
17965 "has no connection with filesystem pathnames. When the address of an "
17966 "abstract socket is returned, the returned I<addrlen> is greater than "
17967 "I<sizeof(sa_family_t)> (i.e., greater than 2), and the name of the socket is "
17968 "contained in the first I<(addrlen - sizeof(sa_family_t))> bytes of "
17969 "I<sun_path>. The abstract socket namespace is a nonportable Linux "
17974 #: build/C/man7/unix.7:159
17976 msgid "Pathname sockets"
17979 #. type: Plain text
17980 #: build/C/man7/unix.7:162
17982 "When binding a socket to a pathname, a few rules should be observed for "
17983 "maximum portability and ease of coding:"
17986 #. type: Plain text
17987 #: build/C/man7/unix.7:166
17988 msgid "The pathname in I<sun_path> should be null-terminated."
17991 #. type: Plain text
17992 #: build/C/man7/unix.7:170
17994 "The length of the pathname, including the terminating null byte, should not "
17995 "exceed the size of I<sun_path>."
17998 #. type: Plain text
17999 #: build/C/man7/unix.7:176
18001 "The I<addrlen> argument that describes the enclosing I<sockaddr_un> "
18002 "structure should have a value of at least:"
18005 #. type: Plain text
18006 #: build/C/man7/unix.7:179
18008 msgid " offsetof(struct sockaddr_un, sun_path)+strlen(addr.sun_path)+1\n"
18011 #. type: Plain text
18012 #: build/C/man7/unix.7:185
18014 "or, more simply, I<addrlen> can be specified as I<sizeof(struct "
18018 #. Linux does this, including for the case where the supplied path
18020 #. type: Plain text
18021 #: build/C/man7/unix.7:193
18023 "There is some variation in how implementations handle UNIX domain socket "
18024 "addresses that do not follow the above rules. For example, some (but not "
18025 "all) implementations append a null terminator if none is present in the "
18026 "supplied I<sun_path>."
18030 #. Modern BSDs generally have 104, Tru64 and AIX have 104,
18031 #. Solaris and Irix have 108
18032 #. type: Plain text
18033 #: build/C/man7/unix.7:202
18035 "When coding portable applications, keep in mind that some implementations "
18036 "have I<sun_path> as short as 92 bytes."
18039 #. type: Plain text
18040 #: build/C/man7/unix.7:220
18042 "Various system calls (B<accept>(2), B<recvfrom>(2), B<getsockname>(2), "
18043 "B<getpeername>(2)) return socket address structures. When applied to UNIX "
18044 "domain sockets, the value-result I<addrlen> argument supplied to the call "
18045 "should be initialized as above. Upon return, the argument is set to "
18046 "indicate the I<actual> size of the address structure. The caller should "
18047 "check the value returned in this argument: if the output value exceeds the "
18048 "input value, then there is no guarantee that a null terminator is present in "
18049 "I<sun_path>. (See BUGS.)"
18052 #. type: Plain text
18053 #: build/C/man7/unix.7:233
18055 "For historical reasons, these socket options are specified with a "
18056 "B<SOL_SOCKET> type even though they are B<AF_UNIX> specific. They can be "
18057 "set with B<setsockopt>(2) and read with B<getsockopt>(2) by specifying "
18058 "B<SOL_SOCKET> as the socket family."
18062 #: build/C/man7/unix.7:233
18064 msgid "B<SO_PASSCRED>"
18067 #. type: Plain text
18068 #: build/C/man7/unix.7:240
18070 "Enables the receiving of the credentials of the sending process in an "
18071 "ancillary message. When this option is set and the socket is not yet "
18072 "connected a unique name in the abstract namespace will be generated "
18073 "automatically. Expects an integer boolean flag."
18077 #: build/C/man7/unix.7:240
18079 msgid "Autobind feature"
18082 #. i.e., sizeof(short)
18083 #. type: Plain text
18084 #: build/C/man7/unix.7:260
18086 "If a B<bind>(2) call specifies I<addrlen> as I<sizeof(sa_family_t)>, or the "
18087 "B<SO_PASSCRED> socket option was specified for a socket that was not "
18088 "explicitly bound to an address, then the socket is autobound to an abstract "
18089 "address. The address consists of a null byte followed by 5 bytes in the "
18090 "character set I<[0-9a-f]>. Thus, there is a limit of 2^20 autobind "
18091 "addresses. (From Linux 2.1.15, when the autobind feature was added, 8 bytes "
18092 "were used, and the limit was thus 2^32 autobind addresses. The change to 5 "
18093 "bytes came in Linux 2.3.15.)"
18096 #. type: Plain text
18097 #: build/C/man7/unix.7:263
18099 "The following paragraphs describe domain-specific details and unsupported "
18100 "features of the sockets API for UNIX domain sockets on Linux."
18103 #. type: Plain text
18104 #: build/C/man7/unix.7:271
18106 "UNIX domain sockets do not support the transmission of out-of-band data (the "
18107 "B<MSG_OOB> flag for B<send>(2) and B<recv>(2))."
18110 #. type: Plain text
18111 #: build/C/man7/unix.7:276
18112 msgid "The B<send>(2) B<MSG_MORE> flag is not supported by UNIX domain sockets."
18115 #. type: Plain text
18116 #: build/C/man7/unix.7:284
18118 "The use of B<MSG_TRUNC> in the I<flags> argument of B<recv>(2) is not "
18119 "supported by UNIX domain sockets."
18122 #. type: Plain text
18123 #: build/C/man7/unix.7:296
18125 "The B<SO_SNDBUF> socket option does have an effect for UNIX domain sockets, "
18126 "but the B<SO_RCVBUF> option does not. For datagram sockets, the "
18127 "B<SO_SNDBUF> value imposes an upper limit on the size of outgoing "
18128 "datagrams. This limit is calculated as the doubled (see B<socket>(7)) "
18129 "option value less 32 bytes used for overhead."
18133 #: build/C/man7/unix.7:296
18135 msgid "Ancillary messages"
18138 #. type: Plain text
18139 #: build/C/man7/unix.7:318
18141 "Ancillary data is sent and received using B<sendmsg>(2) and B<recvmsg>(2). "
18142 "For historical reasons the ancillary message types listed below are "
18143 "specified with a B<SOL_SOCKET> type even though they are B<AF_UNIX> "
18144 "specific. To send them set the I<cmsg_level> field of the struct I<cmsghdr> "
18145 "to B<SOL_SOCKET> and the I<cmsg_type> field to the type. For more "
18146 "information see B<cmsg>(3)."
18150 #: build/C/man7/unix.7:318
18152 msgid "B<SCM_RIGHTS>"
18155 #. type: Plain text
18156 #: build/C/man7/unix.7:324
18158 "Send or receive a set of open file descriptors from another process. The "
18159 "data portion contains an integer array of the file descriptors. The passed "
18160 "file descriptors behave as though they have been created with B<dup>(2)."
18164 #: build/C/man7/unix.7:324
18166 msgid "B<SCM_CREDENTIALS>"
18169 #. type: Plain text
18170 #: build/C/man7/unix.7:334
18172 "Send or receive UNIX credentials. This can be used for authentication. The "
18173 "credentials are passed as a I<struct ucred> ancillary message. Thus "
18174 "structure is defined in I<E<lt>sys/socket.hE<gt>> as follows:"
18177 #. type: Plain text
18178 #: build/C/man7/unix.7:342
18182 " pid_t pid; /* process ID of the sending process */\n"
18183 " uid_t uid; /* user ID of the sending process */\n"
18184 " gid_t gid; /* group ID of the sending process */\n"
18188 #. type: Plain text
18189 #: build/C/man7/unix.7:351
18191 "Since glibc 2.8, the B<_GNU_SOURCE> feature test macro must be defined "
18192 "(before including I<any> header files) in order to obtain the definition of "
18196 #. type: Plain text
18197 #: build/C/man7/unix.7:367
18199 "The credentials which the sender specifies are checked by the kernel. A "
18200 "process with effective user ID 0 is allowed to specify values that do not "
18201 "match its own. The sender must specify its own process ID (unless it has "
18202 "the capability B<CAP_SYS_ADMIN>), its user ID, effective user ID, or saved "
18203 "set-user-ID (unless it has B<CAP_SETUID>), and its group ID, effective group "
18204 "ID, or saved set-group-ID (unless it has B<CAP_SETGID>). To receive a "
18205 "I<struct ucred> message the B<SO_PASSCRED> option must be enabled on the "
18209 #. type: Plain text
18210 #: build/C/man7/unix.7:378
18213 "B<int>I< value>B<;>\n"
18214 "I<error>B< = ioctl(>I<unix_socket>B<, >I<ioctl_type>B<, &>I<value>B<);>\n"
18217 #. type: Plain text
18218 #: build/C/man7/unix.7:383
18219 msgid "I<ioctl_type> can be:"
18222 #. type: Plain text
18223 #: build/C/man7/unix.7:410
18225 "The specified local address is already in use or the filesystem socket "
18226 "object already exists."
18229 #. type: Plain text
18230 #: build/C/man7/unix.7:416
18232 "The remote address specified by B<connect>(2) was not a listening socket. "
18233 "This error can also occur if the target pathname is not a socket."
18237 #: build/C/man7/unix.7:416
18239 msgid "B<ECONNRESET>"
18242 #. type: Plain text
18243 #: build/C/man7/unix.7:419
18244 msgid "Remote socket was unexpectedly closed."
18247 #. type: Plain text
18248 #: build/C/man7/unix.7:422
18249 msgid "User memory address was not valid."
18252 #. type: Plain text
18253 #: build/C/man7/unix.7:431
18255 "Invalid argument passed. A common cause is that the value B<AF_UNIX> was "
18256 "not specified in the I<sun_type> field of passed addresses, or the socket "
18257 "was in an invalid state for the applied operation."
18260 #. type: Plain text
18261 #: build/C/man7/unix.7:436
18263 "B<connect>(2) called on an already connected socket or a target address was "
18264 "specified on a connected socket."
18267 #. type: Plain text
18268 #: build/C/man7/unix.7:441
18270 "The pathname in the remote address specified to B<connect>(2) did not "
18275 #: build/C/man7/unix.7:441
18280 #. type: Plain text
18281 #: build/C/man7/unix.7:447
18282 msgid "Socket operation needs a target address, but the socket is not connected."
18285 #. type: Plain text
18286 #: build/C/man7/unix.7:451
18288 "Stream operation called on non-stream oriented socket or tried to use the "
18289 "out-of-band data option."
18292 #. type: Plain text
18293 #: build/C/man7/unix.7:455
18294 msgid "The sender passed invalid credentials in the I<struct ucred>."
18297 #. type: Plain text
18298 #: build/C/man7/unix.7:467
18300 "Remote socket was closed on a stream socket. If enabled, a B<SIGPIPE> is "
18301 "sent as well. This can be avoided by passing the B<MSG_NOSIGNAL> flag to "
18302 "B<sendmsg>(2) or B<recvmsg>(2)."
18306 #: build/C/man7/unix.7:467
18308 msgid "B<EPROTONOSUPPORT>"
18311 #. type: Plain text
18312 #: build/C/man7/unix.7:471
18313 msgid "Passed protocol is not B<AF_UNIX>."
18317 #: build/C/man7/unix.7:471
18319 msgid "B<EPROTOTYPE>"
18322 #. type: Plain text
18323 #: build/C/man7/unix.7:477
18325 "Remote socket does not match the local socket type (B<SOCK_DGRAM> versus "
18329 #. type: Plain text
18330 #: build/C/man7/unix.7:480
18331 msgid "Unknown socket type."
18334 #. type: Plain text
18335 #: build/C/man7/unix.7:484
18337 "Other errors can be generated by the generic socket layer or by the "
18338 "filesystem while generating a filesystem socket object. See the appropriate "
18339 "manual pages for more information."
18342 #. type: Plain text
18343 #: build/C/man7/unix.7:490
18345 "B<SCM_CREDENTIALS> and the abstract namespace were introduced with Linux 2.2 "
18346 "and should not be used in portable programs. (Some BSD-derived systems also "
18347 "support credential passing, but the implementation details differ.)"
18350 #. type: Plain text
18351 #: build/C/man7/unix.7:501
18353 "In the Linux implementation, sockets which are visible in the filesystem "
18354 "honor the permissions of the directory they are in. Their owner, group, and "
18355 "permissions can be changed. Creation of a new socket will fail if the "
18356 "process does not have write and search (execute) permission on the directory "
18357 "the socket is created in. Connecting to the socket object requires "
18358 "read/write permission. This behavior differs from many BSD-derived systems "
18359 "which ignore permissions for UNIX domain sockets. Portable programs should "
18360 "not rely on this feature for security."
18363 #. type: Plain text
18364 #: build/C/man7/unix.7:509
18366 "Binding to a socket with a filename creates a socket in the filesystem that "
18367 "must be deleted by the caller when it is no longer needed (using "
18368 "B<unlink>(2)). The usual UNIX close-behind semantics apply; the socket can "
18369 "be unlinked at any time and will be finally removed from the filesystem when "
18370 "the last reference to it is closed."
18373 #. type: Plain text
18374 #: build/C/man7/unix.7:518
18376 "To pass file descriptors or credentials over a B<SOCK_STREAM>, you need to "
18377 "send or receive at least one byte of nonancillary data in the same "
18378 "B<sendmsg>(2) or B<recvmsg>(2) call."
18381 #. type: Plain text
18382 #: build/C/man7/unix.7:521
18383 msgid "UNIX domain stream sockets do not support the notion of out-of-band data."
18386 #. The behavior on Solaris is quite similar.
18387 #. type: Plain text
18388 #: build/C/man7/unix.7:546
18390 "When binding a socket to an address, Linux is one of the implementations "
18391 "that appends a null terminator if none is supplied in I<sun_path>. In most "
18392 "cases this is unproblematic: when the socket address is retrieved, it will "
18393 "be one byte longer than that supplied when the socket was bound. However, "
18394 "there is one case where confusing behavior can result: if 108 non-null bytes "
18395 "are supplied when a socket is bound, then the addition of the null "
18396 "terminator takes the length of the pathname beyond I<sizeof(sun_path)>. "
18397 "Consequently, when retrieving the socket address (for example, via "
18398 "B<accept>(2)), if the input I<addrlen> argument for the retrieving call is "
18399 "specified as I<sizeof(struct sockaddr_un)>, then the returned address "
18400 "structure I<won't> have a null terminator in I<sun_path>."
18403 #. i.e., traditional BSD
18404 #. type: Plain text
18405 #: build/C/man7/unix.7:556
18407 "In addition, some implementations don't require a null terminator when "
18408 "binding a socket (the I<addrlen> argument is used to determine the length of "
18409 "I<sun_path>) and when the socket address is retrieved on these "
18410 "implementations, there is no null terminator in I<sun_path>."
18413 #. type: Plain text
18414 #: build/C/man7/unix.7:561
18416 "Applications that retrieve socket addresses can (portably) code to handle "
18417 "the possibility that there is no null terminator in I<sun_path> by "
18418 "respecting the fact that the number of valid bytes in the pathname is:"
18421 #. The following patch to amend kernel behavior was rejected:
18422 #. http://thread.gmane.org/gmane.linux.kernel.api/2437
18423 #. Subject: [patch] Fix handling of overlength pathname in AF_UNIX sun_path
18425 #. And there was a related discussion in the Austin list:
18426 #. http://thread.gmane.org/gmane.comp.standards.posix.austin.general/5735
18427 #. Subject: Having a sun_path with no null terminator
18430 #. FIXME . Track http://austingroupbugs.net/view.php?id=561
18431 #. type: Plain text
18432 #: build/C/man7/unix.7:573
18434 msgid " strnlen(addr.sun_path, addrlen - offsetof(sockaddr_un, sun_path))\n"
18437 #. type: Plain text
18438 #: build/C/man7/unix.7:585
18440 "Alternatively, an application can retrieve the socket address by allocating "
18441 "a buffer of size I<sizeof(struct sockaddr_un)+1> that is zeroed out before "
18442 "the retrieval. The retrieving call can specify I<addrlen> as "
18443 "I<sizeof(struct sockaddr_un)>, and the extra zero byte ensures that there "
18444 "will be a null terminator for the string returned in I<sun_path>:"
18447 #. type: Plain text
18448 #: build/C/man7/unix.7:589
18450 msgid "void *addrp;\n"
18453 #. type: Plain text
18454 #: build/C/man7/unix.7:595
18457 "addrlen = sizeof(struct sockaddr_un);\n"
18458 "addrp = malloc(addrlen + 1);\n"
18459 "if (addrp == NULL)\n"
18460 " /* Handle error */ ;\n"
18461 "memset(addrp, 0, addrlen + 1);\n"
18464 #. type: Plain text
18465 #: build/C/man7/unix.7:598
18468 "if (getsockname(sfd, (struct sockaddr *) addrp, &addrlen)) == -1)\n"
18469 " /* handle error */ ;\n"
18472 #. type: Plain text
18473 #: build/C/man7/unix.7:600
18476 "printf(\"sun_path = %s\\en\", ((struct sockaddr_un *) "
18477 "addrp)-E<gt>sun_path);\n"
18480 #. type: Plain text
18481 #: build/C/man7/unix.7:608
18483 "This sort of messiness can be avoided if it is guaranteed that the "
18484 "applications that I<create> pathname sockets follow the rules outlined above "
18485 "under I<Pathname sockets>."
18488 #. type: Plain text
18489 #: build/C/man7/unix.7:611
18490 msgid "See B<bind>(2)."
18493 #. type: Plain text
18494 #: build/C/man7/unix.7:616
18495 msgid "For an example of the use of B<SCM_RIGHTS> see B<cmsg>(3)."
18498 #. type: Plain text
18499 #: build/C/man7/unix.7:624
18501 "B<recvmsg>(2), B<sendmsg>(2), B<socket>(2), B<socketpair>(2), B<cmsg>(3), "
18502 "B<capabilities>(7), B<credentials>(7), B<socket>(7)"
18506 #: build/C/man7/x25.7:12
18511 #. type: Plain text
18512 #: build/C/man7/x25.7:15
18513 msgid "x25 - ITU-T X.25 / ISO-8208 protocol interface."
18516 #. type: Plain text
18517 #: build/C/man7/x25.7:19
18518 msgid "B<#include E<lt>linux/x25.hE<gt>>"
18521 #. type: Plain text
18522 #: build/C/man7/x25.7:21
18523 msgid "B<x25_socket = socket(AF_X25, SOCK_SEQPACKET, 0);>"
18526 #. type: Plain text
18527 #: build/C/man7/x25.7:30
18529 "X25 sockets provide an interface to the X.25 packet layer protocol. This "
18530 "allows applications to communicate over a public X.25 data network as "
18531 "standardized by International Telecommunication Union's recommendation X.25 "
18532 "(X.25 DTE-DCE mode). X25 sockets can also be used for communication without "
18533 "an intermediate X.25 network (X.25 DTE-DTE mode) as described in ISO-8208."
18536 #. type: Plain text
18537 #: build/C/man7/x25.7:47
18539 "Message boundaries are preserved \\(em a B<read>(2) from a socket will "
18540 "retrieve the same chunk of data as output with the corresponding B<write>(2) "
18541 "to the peer socket. When necessary, the kernel takes care of segmenting and "
18542 "reassembling long messages by means of the X.25 M-bit. There is no "
18543 "hard-coded upper limit for the message size. However, reassembling of a "
18544 "long message might fail if there is a temporary lack of system resources or "
18545 "when other constraints (such as socket memory or buffer size limits) become "
18546 "effective. If that occurs, the X.25 connection will be reset."
18550 #: build/C/man7/x25.7:47
18552 msgid "Socket addresses"
18555 #. type: Plain text
18556 #: build/C/man7/x25.7:54
18558 "The B<AF_X25> socket address family uses the I<struct sockaddr_x25> for "
18559 "representing network addresses as defined in ITU-T recommendation X.121."
18562 #. type: Plain text
18563 #: build/C/man7/x25.7:61
18566 "struct sockaddr_x25 {\n"
18567 " sa_family_t sx25_family; /* must be AF_X25 */\n"
18568 " x25_address sx25_addr; /* X.121 Address */\n"
18572 #. type: Plain text
18573 #: build/C/man7/x25.7:72
18575 "I<sx25_addr> contains a char array I<x25_addr[]> to be interpreted as a "
18576 "null-terminated string. I<sx25_addr.x25_addr[]> consists of up to 15 (not "
18577 "counting the terminating null byte) ASCII characters forming the X.121 "
18578 "address. Only the decimal digit characters from \\(aq0\\(aq to \\(aq9\\(aq "
18582 #. type: Plain text
18583 #: build/C/man7/x25.7:81
18585 "The following X.25-specific socket options can be set by using "
18586 "B<setsockopt>(2) and read with B<getsockopt>(2) with the I<level> argument "
18587 "set to B<SOL_X25>."
18591 #: build/C/man7/x25.7:81
18593 msgid "B<X25_QBITINCL>"
18596 #. type: Plain text
18597 #: build/C/man7/x25.7:100
18599 "Controls whether the X.25 Q-bit (Qualified Data Bit) is accessible by the "
18600 "user. It expects an integer argument. If set to 0 (default), the Q-bit is "
18601 "never set for outgoing packets and the Q-bit of incoming packets is "
18602 "ignored. If set to 1, an additional first byte is prepended to each message "
18603 "read from or written to the socket. For data read from the socket, a 0 "
18604 "first byte indicates that the Q-bits of the corresponding incoming data "
18605 "packets were not set. A first byte with value 1 indicates that the Q-bit of "
18606 "the corresponding incoming data packets was set. If the first byte of the "
18607 "data written to the socket is 1, the Q-bit of the corresponding outgoing "
18608 "data packets will be set. If the first byte is 0, the Q-bit will not be "
18612 #. type: Plain text
18613 #: build/C/man7/x25.7:102
18614 msgid "The AF_X25 protocol family is a new feature of Linux 2.2."
18617 #. type: Plain text
18618 #: build/C/man7/x25.7:105
18619 msgid "Plenty, as the X.25 PLP implementation is B<CONFIG_EXPERIMENTAL>."
18622 #. type: Plain text
18623 #: build/C/man7/x25.7:107
18624 msgid "This man page is incomplete."
18627 #. type: Plain text
18628 #: build/C/man7/x25.7:114
18630 "There is no dedicated application programmer's header file yet; you need to "
18631 "include the kernel header file I<E<lt>linux/x25.hE<gt>>. "
18632 "B<CONFIG_EXPERIMENTAL> might also imply that future versions of the "
18633 "interface are not binary compatible."
18636 #. type: Plain text
18637 #: build/C/man7/x25.7:118
18639 "X.25 N-Reset events are not propagated to the user process yet. Thus, if a "
18640 "reset occurred, data might be lost without notice."
18643 #. type: Plain text
18644 #: build/C/man7/x25.7:121
18645 msgid "B<socket>(2), B<socket>(7)"
18648 #. type: Plain text
18649 #: build/C/man7/x25.7:126
18651 "Jonathan Simon Naylor: \\(lqThe Re-Analysis and Re-Implementation of "
18652 "X.25.\\(rq The URL is E<.UR "
18653 "ftp://ftp.pspt.fi\\:/pub\\:/ham\\:/linux\\:/ax25\\:/x25doc.tgz> E<.UE .>"