2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Definitions for the IP module.
8 * Version: @(#)ip.h 1.0.2 05/07/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
15 * Mike McLagan : Routing by source
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
25 #include <linux/types.h>
28 #include <linux/skbuff.h>
30 #include <net/inet_sock.h>
31 #include <net/route.h>
34 #include <net/flow_dissector.h>
38 struct inet_skb_parm {
40 struct ip_options opt; /* Compiled IP options */
43 #define IPSKB_FORWARDED BIT(0)
44 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
45 #define IPSKB_XFRM_TRANSFORMED BIT(2)
46 #define IPSKB_FRAG_COMPLETE BIT(3)
47 #define IPSKB_REROUTED BIT(4)
48 #define IPSKB_DOREDIRECT BIT(5)
49 #define IPSKB_FRAG_PMTU BIT(6)
50 #define IPSKB_FRAG_SEGS BIT(7)
51 #define IPSKB_L3SLAVE BIT(8)
56 static inline bool ipv4_l3mdev_skb(u16 flags)
58 return !!(flags & IPSKB_L3SLAVE);
61 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
63 return ip_hdr(skb)->ihl * 4;
67 struct sockcm_cookie sockc;
70 struct ip_options_rcu *opt;
77 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
78 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
81 struct ip_ra_chain __rcu *next;
84 void (*destructor)(struct sock *);
85 struct sock *saved_sk;
90 extern struct ip_ra_chain __rcu *ip_ra_chain;
93 #define IP_CE 0x8000 /* Flag: "Congestion" */
94 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
95 #define IP_MF 0x2000 /* Flag: "More Fragments" */
96 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
98 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
106 int igmp_mc_init(void);
109 * Functions provided by ip.c
112 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
113 __be32 saddr, __be32 daddr,
114 struct ip_options_rcu *opt);
115 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
116 struct net_device *orig_dev);
117 int ip_local_deliver(struct sk_buff *skb);
118 int ip_mr_input(struct sk_buff *skb);
119 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
120 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
121 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
122 int (*output)(struct net *, struct sock *, struct sk_buff *));
123 void ip_send_check(struct iphdr *ip);
124 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
125 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
127 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
129 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
130 int getfrag(void *from, char *to, int offset, int len,
131 int odd, struct sk_buff *skb),
132 void *from, int len, int protolen,
133 struct ipcm_cookie *ipc,
136 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
137 struct sk_buff *skb);
138 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
139 int offset, size_t size, int flags);
140 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
141 struct sk_buff_head *queue,
142 struct inet_cork *cork);
143 int ip_send_skb(struct net *net, struct sk_buff *skb);
144 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
145 void ip_flush_pending_frames(struct sock *sk);
146 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
147 int getfrag(void *from, char *to, int offset,
148 int len, int odd, struct sk_buff *skb),
149 void *from, int length, int transhdrlen,
150 struct ipcm_cookie *ipc, struct rtable **rtp,
153 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
155 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
158 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
160 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
163 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
165 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
169 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
170 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
172 void ip4_datagram_release_cb(struct sock *sk);
174 struct ip_reply_arg {
178 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
179 /* -1 if not needed */
185 #define IP_REPLY_ARG_NOSRCCHECK 1
187 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
189 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
192 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
193 const struct ip_options *sopt,
194 __be32 daddr, __be32 saddr,
195 const struct ip_reply_arg *arg,
198 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
199 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
200 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
201 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
202 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
203 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
204 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
205 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
206 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
207 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
209 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
210 unsigned long snmp_fold_field(void __percpu *mib, int offt);
211 #if BITS_PER_LONG==32
212 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
213 size_t syncp_offset);
214 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
216 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
219 return snmp_get_cpu_field(mib, cpu, offct);
223 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
225 return snmp_fold_field(mib, offt);
229 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
232 for_each_possible_cpu(c) { \
233 for (i = 0; stats_list[i].name; i++) \
234 buff64[i] += snmp_get_cpu_field64( \
236 c, stats_list[i].entry, \
241 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
244 for_each_possible_cpu(c) { \
245 for (i = 0; stats_list[i].name; i++) \
246 buff[i] += snmp_get_cpu_field( \
248 c, stats_list[i].entry); \
252 void inet_get_local_port_range(struct net *net, int *low, int *high);
255 static inline int inet_is_local_reserved_port(struct net *net, int port)
257 if (!net->ipv4.sysctl_local_reserved_ports)
259 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
262 static inline bool sysctl_dev_name_is_allowed(const char *name)
264 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
268 static inline int inet_is_local_reserved_port(struct net *net, int port)
274 __be32 inet_current_timestamp(void);
276 /* From inetpeer.c */
277 extern int inet_peer_threshold;
278 extern int inet_peer_minttl;
279 extern int inet_peer_maxttl;
281 void ipfrag_init(void);
283 void ip_static_sysctl_init(void);
285 #define IP4_REPLY_MARK(net, mark) \
286 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
288 static inline bool ip_is_fragment(const struct iphdr *iph)
290 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
296 /* The function in 2.2 was invalid, producing wrong result for
297 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
299 int ip_decrease_ttl(struct iphdr *iph)
301 u32 check = (__force u32)iph->check;
302 check += (__force u32)htons(0x0100);
303 iph->check = (__force __sum16)(check + (check>=0xFFFF));
308 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
310 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
312 return pmtudisc == IP_PMTUDISC_DO ||
313 (pmtudisc == IP_PMTUDISC_WANT &&
314 !(dst_metric_locked(dst, RTAX_MTU)));
317 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
319 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
320 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
323 static inline bool ip_sk_use_pmtu(const struct sock *sk)
325 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
328 static inline bool ip_sk_ignore_df(const struct sock *sk)
330 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
331 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
334 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
337 struct net *net = dev_net(dst->dev);
339 if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
340 dst_metric_locked(dst, RTAX_MTU) ||
344 return min(dst->dev->mtu, IP_MAX_MTU);
347 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
348 const struct sk_buff *skb)
350 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
351 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
353 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
356 return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
359 u32 ip_idents_reserve(u32 hash, int segs);
360 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
362 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
363 struct sock *sk, int segs)
365 struct iphdr *iph = ip_hdr(skb);
367 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
368 /* This is only to work around buggy Windows95/2000
369 * VJ compression implementations. If the ID field
370 * does not change, they drop every other packet in
371 * a TCP stream using header compression.
373 if (sk && inet_sk(sk)->inet_daddr) {
374 iph->id = htons(inet_sk(sk)->inet_id);
375 inet_sk(sk)->inet_id += segs;
380 __ip_select_ident(net, iph, segs);
384 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
387 ip_select_ident_segs(net, skb, sk, 1);
390 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
392 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
396 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
397 * Equivalent to : flow->v4addrs.src = iph->saddr;
398 * flow->v4addrs.dst = iph->daddr;
400 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
401 const struct iphdr *iph)
403 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
404 offsetof(typeof(flow->addrs), v4addrs.src) +
405 sizeof(flow->addrs.v4addrs.src));
406 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
407 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
410 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
412 const struct iphdr *iph = skb_gro_network_header(skb);
414 return csum_tcpudp_nofold(iph->saddr, iph->daddr,
415 skb_gro_len(skb), proto, 0);
419 * Map a multicast IP onto multicast MAC for type ethernet.
422 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
424 __u32 addr=ntohl(naddr);
436 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
437 * Leave P_Key as 0 to be filled in by driver.
440 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
443 unsigned char scope = broadcast[5] & 0xF;
445 buf[0] = 0; /* Reserved */
446 buf[1] = 0xff; /* Multicast QPN */
451 buf[5] = 0x10 | scope; /* scope from broadcast address */
452 buf[6] = 0x40; /* IPv4 signature */
454 buf[8] = broadcast[8]; /* P_Key */
455 buf[9] = broadcast[9];
462 buf[19] = addr & 0xff;
464 buf[18] = addr & 0xff;
466 buf[17] = addr & 0xff;
468 buf[16] = addr & 0x0f;
471 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
473 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
474 memcpy(buf, broadcast, 4);
476 memcpy(buf, &naddr, sizeof(naddr));
479 #if IS_ENABLED(CONFIG_IPV6)
480 #include <linux/ipv6.h>
483 static __inline__ void inet_reset_saddr(struct sock *sk)
485 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
486 #if IS_ENABLED(CONFIG_IPV6)
487 if (sk->sk_family == PF_INET6) {
488 struct ipv6_pinfo *np = inet6_sk(sk);
490 memset(&np->saddr, 0, sizeof(np->saddr));
491 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
498 static inline unsigned int ipv4_addr_hash(__be32 ip)
500 return (__force unsigned int) ip;
503 bool ip_call_ra_chain(struct sk_buff *skb);
506 * Functions provided by ip_fragment.c
509 enum ip_defrag_users {
510 IP_DEFRAG_LOCAL_DELIVER,
511 IP_DEFRAG_CALL_RA_CHAIN,
512 IP_DEFRAG_CONNTRACK_IN,
513 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
514 IP_DEFRAG_CONNTRACK_OUT,
515 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
516 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
517 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
525 /* Return true if the value of 'user' is between 'lower_bond'
526 * and 'upper_bond' inclusively.
528 static inline bool ip_defrag_user_in_between(u32 user,
529 enum ip_defrag_users lower_bond,
530 enum ip_defrag_users upper_bond)
532 return user >= lower_bond && user <= upper_bond;
535 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
537 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
539 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
544 int ip_frag_mem(struct net *net);
547 * Functions provided by ip_forward.c
550 int ip_forward(struct sk_buff *skb);
553 * Functions provided by ip_options.c
556 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
557 __be32 daddr, struct rtable *rt, int is_frag);
559 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
560 const struct ip_options *sopt);
561 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
563 return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
566 void ip_options_fragment(struct sk_buff *skb);
567 int ip_options_compile(struct net *net, struct ip_options *opt,
568 struct sk_buff *skb);
569 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
570 unsigned char *data, int optlen);
571 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
572 unsigned char __user *data, int optlen);
573 void ip_options_undo(struct ip_options *opt);
574 void ip_forward_options(struct sk_buff *skb);
575 int ip_options_rcv_srr(struct sk_buff *skb);
578 * Functions provided by ip_sockglue.c
581 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
582 void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int tlen, int offset);
583 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
584 struct ipcm_cookie *ipc, bool allow_ipv6);
585 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
586 unsigned int optlen);
587 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
589 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
590 char __user *optval, unsigned int optlen);
591 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
592 char __user *optval, int __user *optlen);
593 int ip_ra_control(struct sock *sk, unsigned char on,
594 void (*destructor)(struct sock *));
596 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
597 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
598 u32 info, u8 *payload);
599 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
602 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
604 ip_cmsg_recv_offset(msg, skb, 0, 0);
607 bool icmp_global_allow(void);
608 extern int sysctl_icmp_msgs_per_sec;
609 extern int sysctl_icmp_msgs_burst;
611 #ifdef CONFIG_PROC_FS
612 int ip_misc_proc_init(void);