2 .\" This man page is Copyright (C) 1999 Andi Kleen <ak@muc.de>.
4 .\" %%%LICENSE_START(VERBATIM_ONE_PARA)
5 .\" Permission is granted to distribute possibly modified copies
6 .\" of this page provided the header is included verbatim,
7 .\" and in case of nontrivial modification author and date
8 .\" of the modification is added to the header.
11 .\" $Id: netdevice.7,v 1.10 2000/08/17 10:09:54 ak Exp $
13 .\" Modified, 2004-11-25, mtk, formatting and a few wording fixes
15 .\" Modified, 2011-11-02, <bidulock@openss7.org>, added many basic
16 .\" but missing ioctls, such as SIOCGIFADDR.
18 .TH NETDEVICE 7 2012-04-26 "Linux" "Linux Programmer's Manual"
20 netdevice \- low-level access to Linux network devices
22 .B "#include <sys/ioctl.h>"
24 .B "#include <net/if.h>"
26 This man page describes the sockets interface which is used to configure
29 Linux supports some standard ioctls to configure network devices.
30 They can be used on any socket's file descriptor regardless of the
39 char ifr_name[IFNAMSIZ]; /* Interface name */
41 struct sockaddr ifr_addr;
42 struct sockaddr ifr_dstaddr;
43 struct sockaddr ifr_broadaddr;
44 struct sockaddr ifr_netmask;
45 struct sockaddr ifr_hwaddr;
51 char ifr_slave[IFNAMSIZ];
52 char ifr_newname[IFNAMSIZ];
58 int ifc_len; /* size of buffer */
60 char *ifc_buf; /* buffer address */
61 struct ifreq *ifc_req; /* array of structures */
67 Normally, the user specifies which device to affect by setting
69 to the name of the interface.
70 All other members of the structure may
73 If an ioctl is marked as privileged then using it requires an effective
77 If this is not the case
84 return the name of the interface in
86 This is the only ioctl which returns its result in
90 Retrieve the interface index of the interface into
93 .BR SIOCGIFFLAGS ", " SIOCSIFFLAGS
94 Get or set the active flag word of the device.
96 contains a bit mask of the following values:
97 .\" Do not right adjust text blocks in tables
104 IFF_UP:Interface is running.
105 IFF_BROADCAST:Valid broadcast address set.
106 IFF_DEBUG:Internal debugging flag.
107 IFF_LOOPBACK:Interface is a loopback interface.
108 IFF_POINTOPOINT:Interface is a point-to-point link.
109 IFF_RUNNING:Resources allocated.
111 No arp protocol, L2 destination address not set.
113 IFF_PROMISC:Interface is in promiscuous mode.
114 IFF_NOTRAILERS:Avoid use of trailers.
115 IFF_ALLMULTI:Receive all multicast packets.
116 IFF_MASTER:Master of a load balancing bundle.
117 IFF_SLAVE:Slave of a load balancing bundle.
118 IFF_MULTICAST:Supports multicast
119 IFF_PORTSEL:Is able to select media type via ifmap.
120 IFF_AUTOMEDIA:Auto media selection active.
122 The addresses are lost when the interface goes down.
124 IFF_LOWER_UP:Driver signals L1 up (since Linux 2.6.17)
125 IFF_DORMANT:Driver signals dormant (since Linux 2.6.17)
126 IFF_ECHO:Echo sent packets (since Linux 2.6.25)
130 Setting the active flag word is a privileged operation, but any
133 .BR SIOCGIFPFLAGS ", " SIOCSIFPFLAGS
134 Get or set extended (private) flags for the device.
136 contains a bit mask of the following values:
142 IFF_802_1Q_VLAN:Interface is 802.1Q VLAN device.
143 IFF_EBRIDGE:Interface is Ethernet bridging device.
144 IFF_SLAVE_INACTIVE:Interface is inactive bonding slave.
145 IFF_MASTER_8023AD:Interface is 802.3ad bonding master.
146 IFF_MASTER_ALB:Interface is balanced-alb bonding master.
147 IFF_BONDING:Interface is a bonding master or slave.
148 IFF_SLAVE_NEEDARP:Interface needs ARPs for validation.
149 IFF_ISATAP:Interface is RFC4214 ISATAP interface.
152 Setting the extended (private) interface flags is a privileged operation.
154 .BR SIOCGIFADDR ", " SIOCSIFADDR
155 Get or set the address of the device using
157 Setting the interface address is a privileged operation.
158 For compatibility, only
160 addresses are accepted or returned.
162 .BR SIOCGIFDSTADDR ", " SIOCSIFDSTADDR
163 Get or set the destination address of a point-to-point device using
165 For compatibility, only
167 addresses are accepted or returned.
168 Setting the destination address is a privileged operation.
170 .BR SIOCGIFBRDADDR ", " SIOCSIFBRDADDR
171 Get or set the broadcast address for a device using
173 For compatibility, only
175 addresses are accepted or returned.
176 Setting the broadcast address is a privileged operation.
178 .BR SIOCGIFNETMASK ", " SIOCSIFNETMASK
179 Get or set the network mask for a device using
181 For compatibility, only
183 addresses are accepted or returned.
184 Setting the network mask is a privileged operation.
186 .BR SIOCGIFMETRIC ", " SIOCSIFMETRIC
187 Get or set the metric of the device using
189 This is currently not implemented; it sets
191 to 0 if you attempt to read it and returns
193 if you attempt to set it.
195 .BR SIOCGIFMTU ", " SIOCSIFMTU
196 Get or set the MTU (Maximum Transfer Unit) of a device using
198 Setting the MTU is a privileged operation.
200 too small values may cause kernel crashes.
202 .BR SIOCGIFHWADDR ", " SIOCSIFHWADDR
203 Get or set the hardware address of a device using
205 The hardware address is specified in a struct
208 contains the ARPHRD_* device type,
210 the L2 hardware address starting from byte 0.
211 Setting the hardware address is a privileged operation.
213 .B SIOCSIFHWBROADCAST
214 Set the hardware broadcast address of a device from
216 This is a privileged operation.
218 .BR SIOCGIFMAP ", " SIOCSIFMAP
219 Get or set the interface's hardware parameters using
221 Setting the parameters is a privileged operation.
226 unsigned long mem_start;
227 unsigned long mem_end;
228 unsigned short base_addr;
236 The interpretation of the ifmap structure depends on the device driver
237 and the architecture.
239 .BR SIOCADDMULTI ", " SIOCDELMULTI
240 Add an address to or delete an address from the device's link layer
241 multicast filters using
243 These are privileged operations.
248 .BR SIOCGIFTXQLEN ", " SIOCSIFTXQLEN
249 Get or set the transmit queue length of a device using
251 Setting the transmit queue length is a privileged operation.
254 Changes the name of the interface specified in
258 This is a privileged operation.
259 It is only allowed when the interface
263 Return a list of interface (transport layer) addresses.
265 means only addresses of the
267 (IPv4) family for compatibility.
270 structure as argument to the ioctl.
271 It contains a pointer to an array of
275 and its length in bytes in
277 The kernel fills the ifreqs with all current L3 interface addresses that
280 contains the interface name (eth0:1 etc.),
283 The kernel returns with the actual length in
287 is equal to the original length the buffer probably has overflowed
288 and you should retry with a bigger buffer to get all addresses.
289 When no error occurs the ioctl returns 0;
291 Overflow is not an error.
292 .\" Slaving isn't supported in 2.2
295 .\" .BR SIOCGIFSLAVE ", " SIOCSIFSLAVE
296 .\" Get or set the slave device using
298 .\" Setting the slave device is a privileged operation.
300 .\" FIXME add amateur radio stuff.
302 Most protocols support their own ioctls to configure protocol-specific
304 See the protocol man pages for a description.
305 For configuring IP addresses see
308 In addition some devices support private ioctls.
309 These are not described here.
313 and the other ioctls that only accept or return
316 are IP specific and belong in
319 The names of interfaces with no addresses or that don't have the
321 flag set can be found via
324 Local IPv6 IP addresses can be found via
329 glibc 2.1 is missing the
333 Add the following to your program as a workaround:
338 #define ifr_newname ifr_ifru.ifru_slave
344 .BR capabilities (7),