blob: 821cedcc8e73b68af72d1918242c25d757c63d24 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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.
5 *
6 * Definitions for the IP module.
7 *
8 * Version: @(#)ip.h 1.0.2 05/07/93
9 *
Jesper Juhl02c30a82005-05-05 16:16:16 -070010 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 *
14 * Changes:
15 * Mike McLagan : Routing by source
16 *
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.
21 */
22#ifndef _IP_H
23#define _IP_H
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/ip.h>
27#include <linux/in.h>
Arnaldo Carvalho de Meloc9bdd4b2007-03-12 20:09:15 -030028#include <linux/skbuff.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020029
30#include <net/inet_sock.h>
Francesco Fuscoaa661582013-09-24 15:43:09 +020031#include <net/route.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <net/snmp.h>
KOVACS Krisztian86b08d82008-10-01 07:44:42 -070033#include <net/flow.h>
Jiri Pirko1bd758e2015-05-12 14:56:07 +020034#include <net/flow_dissector.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Gao Feng7ed14d92017-04-12 12:34:03 +080036#define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038struct sock;
39
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000040struct inet_skb_parm {
David Ahern0b922b72016-05-10 11:19:51 -070041 int iif;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 struct ip_options opt; /* Compiled IP options */
David Aherna04a4802016-10-16 20:02:52 -070043 u16 flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
Hannes Frederic Sowadf4d9252015-01-23 12:01:26 +010045#define IPSKB_FORWARDED BIT(0)
46#define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
47#define IPSKB_XFRM_TRANSFORMED BIT(2)
48#define IPSKB_FRAG_COMPLETE BIT(3)
49#define IPSKB_REROUTED BIT(4)
50#define IPSKB_DOREDIRECT BIT(5)
Florian Westphald6b915e2015-05-22 16:32:51 +020051#define IPSKB_FRAG_PMTU BIT(6)
Lance Richardson9ee6c5d2016-11-02 16:36:17 -040052#define IPSKB_L3SLAVE BIT(7)
Patrick McHardy5f2d04f2012-08-26 19:13:55 +020053
54 u16 frag_max_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055};
56
David Aherna04a4802016-10-16 20:02:52 -070057static inline bool ipv4_l3mdev_skb(u16 flags)
58{
59 return !!(flags & IPSKB_L3SLAVE);
60}
61
Arnaldo Carvalho de Meloc9bdd4b2007-03-12 20:09:15 -030062static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
63{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -070064 return ip_hdr(skb)->ihl * 4;
Arnaldo Carvalho de Meloc9bdd4b2007-03-12 20:09:15 -030065}
66
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000067struct ipcm_cookie {
Soheil Hassas Yeganeh24025c42016-04-02 23:08:10 -040068 struct sockcm_cookie sockc;
Al Viroc1d18f92006-09-27 18:28:28 -070069 __be32 addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 int oif;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000071 struct ip_options_rcu *opt;
Oliver Hartkopp2244d072010-08-17 08:59:14 +000072 __u8 tx_flags;
Francesco Fuscof02db312013-09-24 15:43:08 +020073 __u8 ttl;
74 __s16 tos;
75 char priority;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076};
77
78#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
Hannes Frederic Sowa4b261c72014-01-20 03:43:08 +010079#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000081struct ip_ra_chain {
Eric Dumazet43a951e2010-10-25 03:32:44 +000082 struct ip_ra_chain __rcu *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 struct sock *sk;
Eric Dumazet592fcb92010-06-09 16:21:07 +000084 union {
85 void (*destructor)(struct sock *);
86 struct sock *saved_sk;
87 };
Eric Dumazet66018502010-06-07 03:12:08 +000088 struct rcu_head rcu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089};
90
Eric Dumazet43a951e2010-10-25 03:32:44 +000091extern struct ip_ra_chain __rcu *ip_ra_chain;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93/* IP flags. */
94#define IP_CE 0x8000 /* Flag: "Congestion" */
95#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
96#define IP_MF 0x2000 /* Flag: "More Fragments" */
97#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
98
99#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
100
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -0200101struct msghdr;
102struct net_device;
103struct packet_type;
104struct rtable;
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -0200105struct sockaddr;
106
WANG Cong72c1d3b2014-01-10 16:09:45 -0800107int igmp_mc_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
109/*
110 * Functions provided by ip.c
111 */
112
Eric Dumazetcfe673b2015-09-25 07:39:16 -0700113int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700114 __be32 saddr, __be32 daddr,
115 struct ip_options_rcu *opt);
116int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
117 struct net_device *orig_dev);
118int ip_local_deliver(struct sk_buff *skb);
119int ip_mr_input(struct sk_buff *skb);
Eric W. Biedermanede20592015-10-07 16:48:47 -0500120int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
121int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
Eric W. Biederman694869b2015-06-12 21:55:31 -0500122int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
123 int (*output)(struct net *, struct sock *, struct sk_buff *));
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700124void ip_send_check(struct iphdr *ip);
Eric W. Biedermancf91a992015-10-07 16:48:45 -0500125int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
Eric W. Biederman33224b12015-10-07 16:48:46 -0500126int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
Eric Dumazetaad88722014-04-15 13:47:15 -0400127
Eric Dumazetb0270e92014-04-15 12:58:34 -0400128int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700129void ip_init(void);
130int ip_append_data(struct sock *sk, struct flowi4 *fl4,
131 int getfrag(void *from, char *to, int offset, int len,
132 int odd, struct sk_buff *skb),
133 void *from, int len, int protolen,
134 struct ipcm_cookie *ipc,
135 struct rtable **rt,
136 unsigned int flags);
137int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
138 struct sk_buff *skb);
139ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
140 int offset, size_t size, int flags);
141struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
142 struct sk_buff_head *queue,
143 struct inet_cork *cork);
144int ip_send_skb(struct net *net, struct sk_buff *skb);
145int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
146void ip_flush_pending_frames(struct sock *sk);
147struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
148 int getfrag(void *from, char *to, int offset,
149 int len, int odd, struct sk_buff *skb),
150 void *from, int length, int transhdrlen,
151 struct ipcm_cookie *ipc, struct rtable **rtp,
152 unsigned int flags);
Herbert Xu1c32c5a2011-03-01 02:36:47 +0000153
David S. Miller77968b72011-05-08 17:12:19 -0700154static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
Herbert Xu1c32c5a2011-03-01 02:36:47 +0000155{
David S. Miller77968b72011-05-08 17:12:19 -0700156 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
Herbert Xu1c32c5a2011-03-01 02:36:47 +0000157}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Francesco Fuscoaa661582013-09-24 15:43:09 +0200159static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
160{
161 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
162}
163
164static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
165{
166 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
167}
168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169/* datagram.c */
Eric Dumazet03645a12015-07-14 08:10:22 +0200170int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700171int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700173void ip4_datagram_release_cb(struct sock *sk);
Steffen Klassert8141ed92013-01-21 02:00:03 +0000174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175struct ip_reply_arg {
176 struct kvec iov[1];
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700177 int flags;
Al Virod6f5493c2006-11-14 21:26:08 -0800178 __wsum csum;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
180 /* -1 if not needed */
Patrick McHardyf0e48db2007-06-04 21:32:46 -0700181 int bound_dev_if;
Eric Dumazet66b13d92011-10-24 03:06:21 -0400182 u8 tos;
Lorenzo Colittie2d118a2016-11-04 02:23:43 +0900183 kuid_t uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184};
185
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700186#define IP_REPLY_ARG_NOSRCCHECK 1
187
KOVACS Krisztian86b08d82008-10-01 07:44:42 -0700188static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
189{
190 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
191}
192
Eric Dumazetbdbbb852015-01-29 21:35:05 -0800193void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
Eric Dumazet24a2d432014-09-27 09:50:55 -0700194 const struct ip_options *sopt,
195 __be32 daddr, __be32 saddr,
196 const struct ip_reply_arg *arg,
David S. Miller70e73412012-06-28 03:21:41 -0700197 unsigned int len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
Eric Dumazet4ce3c182010-06-30 13:31:19 -0700199#define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
Eric Dumazet13415e42016-04-27 16:44:43 -0700200#define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
Eric Dumazet4ce3c182010-06-30 13:31:19 -0700201#define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
Eric Dumazet13415e42016-04-27 16:44:43 -0700202#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
Eric Dumazet4ce3c182010-06-30 13:31:19 -0700203#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
Eric Dumazet13415e42016-04-27 16:44:43 -0700204#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
Pavel Emelyanov61a7e262008-07-18 04:03:08 -0700205#define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
Eric Dumazet13415e42016-04-27 16:44:43 -0700206#define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
David S. Millerf7324ac2014-03-06 15:03:17 -0500207#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
Eric Dumazet13415e42016-04-27 16:44:43 -0700208#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Raghavendra K Tc4c6bc32015-08-30 11:29:41 +0530210u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
WANG Cong698365f2014-05-05 15:55:55 -0700211unsigned long snmp_fold_field(void __percpu *mib, int offt);
Eric Dumazet4ce3c182010-06-30 13:31:19 -0700212#if BITS_PER_LONG==32
Raghavendra K Tc4c6bc32015-08-30 11:29:41 +0530213u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
214 size_t syncp_offset);
WANG Cong698365f2014-05-05 15:55:55 -0700215u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
Eric Dumazet4ce3c182010-06-30 13:31:19 -0700216#else
Raghavendra K Tc4c6bc32015-08-30 11:29:41 +0530217static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
218 size_t syncp_offset)
219{
220 return snmp_get_cpu_field(mib, cpu, offct);
221
222}
223
WANG Cong698365f2014-05-05 15:55:55 -0700224static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
Eric Dumazet4ce3c182010-06-30 13:31:19 -0700225{
226 return snmp_fold_field(mib, offt);
227}
228#endif
YOSHIFUJI Hideaki33490172007-04-20 15:57:15 -0700229
Jia He6348ef22016-09-30 11:28:58 +0800230#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
231{ \
232 int i, c; \
233 for_each_possible_cpu(c) { \
234 for (i = 0; stats_list[i].name; i++) \
235 buff64[i] += snmp_get_cpu_field64( \
236 mib_statistic, \
237 c, stats_list[i].entry, \
238 offset); \
239 } \
240}
241
242#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
243{ \
244 int i, c; \
245 for_each_possible_cpu(c) { \
246 for (i = 0; stats_list[i].name; i++) \
247 buff[i] += snmp_get_cpu_field( \
248 mib_statistic, \
249 c, stats_list[i].entry); \
250 } \
251}
252
Eric W. Biederman0bbf87d2013-09-28 14:10:59 -0700253void inet_get_local_port_range(struct net *net, int *low, int *high);
Stephen Hemminger227b60f2007-10-10 17:30:46 -0700254
David S. Millerfcd77db2014-05-15 13:43:14 -0400255#ifdef CONFIG_SYSCTL
WANG Cong122ff242014-05-12 16:04:53 -0700256static inline int inet_is_local_reserved_port(struct net *net, int port)
Amerigo Wange3826f12010-05-05 00:27:06 +0000257{
WANG Cong122ff242014-05-12 16:04:53 -0700258 if (!net->ipv4.sysctl_local_reserved_ports)
259 return 0;
260 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
Amerigo Wange3826f12010-05-05 00:27:06 +0000261}
WANG Cong20e61da2014-07-25 15:25:08 -0700262
263static inline bool sysctl_dev_name_is_allowed(const char *name)
264{
265 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
266}
267
Krister Johansen4548b682017-01-20 17:49:11 -0800268static inline int inet_prot_sock(struct net *net)
269{
270 return net->ipv4.sysctl_ip_prot_sock;
271}
272
WANG Cong122ff242014-05-12 16:04:53 -0700273#else
274static inline int inet_is_local_reserved_port(struct net *net, int port)
275{
276 return 0;
277}
Krister Johansen4548b682017-01-20 17:49:11 -0800278
279static inline int inet_prot_sock(struct net *net)
280{
281 return PROT_SOCK;
282}
WANG Cong122ff242014-05-12 16:04:53 -0700283#endif
Amerigo Wange3826f12010-05-05 00:27:06 +0000284
Deepa Dinamani822c8682016-02-27 00:32:15 -0800285__be32 inet_current_timestamp(void);
286
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300287/* From inetpeer.c */
288extern int inet_peer_threshold;
289extern int inet_peer_minttl;
290extern int inet_peer_maxttl;
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300291
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700292void ipfrag_init(void);
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300293
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700294void ip_static_sysctl_init(void);
Al Virobd7b1532008-07-15 16:00:59 -0400295
Lorenzo Colittie1108612014-05-13 10:17:33 -0700296#define IP4_REPLY_MARK(net, mark) \
297 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
298
David S. Millerd18cd552011-06-23 21:28:52 -0700299static inline bool ip_is_fragment(const struct iphdr *iph)
300{
301 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
302}
303
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304#ifdef CONFIG_INET
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -0200305#include <net/dst.h>
306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307/* The function in 2.2 was invalid, producing wrong result for
308 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
309static inline
310int ip_decrease_ttl(struct iphdr *iph)
311{
Al Viro5c78f272006-11-14 21:42:26 -0800312 u32 check = (__force u32)iph->check;
313 check += (__force u32)htons(0x0100);
314 iph->check = (__force __sum16)(check + (check>=0xFFFF));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 return --iph->ttl;
316}
317
318static inline
Eric Dumazet4e3f5d72015-09-25 07:39:14 -0700319int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
Eric Dumazet4e3f5d72015-09-25 07:39:14 -0700321 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
322
323 return pmtudisc == IP_PMTUDISC_DO ||
324 (pmtudisc == IP_PMTUDISC_WANT &&
Eric Dumazeta02cec22010-09-22 20:43:57 +0000325 !(dst_metric_locked(dst, RTAX_MTU)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326}
327
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100328static inline bool ip_sk_accept_pmtu(const struct sock *sk)
329{
Hannes Frederic Sowa1b346572014-02-26 01:20:42 +0100330 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
331 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100332}
333
334static inline bool ip_sk_use_pmtu(const struct sock *sk)
335{
336 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
337}
338
WANG Cong60ff7462014-05-04 16:39:18 -0700339static inline bool ip_sk_ignore_df(const struct sock *sk)
Hannes Frederic Sowa1b346572014-02-26 01:20:42 +0100340{
341 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
342 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
343}
344
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100345static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
346 bool forwarding)
347{
348 struct net *net = dev_net(dst->dev);
349
350 if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
351 dst_metric_locked(dst, RTAX_MTU) ||
352 !forwarding)
353 return dst_mtu(dst);
354
355 return min(dst->dev->mtu, IP_MAX_MTU);
356}
357
Shmulik Ladkanifedbb6b42016-06-29 21:47:03 +0300358static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
359 const struct sk_buff *skb)
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100360{
Eric Dumazetcaf3f262015-10-04 21:08:08 -0700361 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100362 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
Eric Dumazetcaf3f262015-10-04 21:08:08 -0700363
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100364 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100365 }
Eric Dumazetcaf3f262015-10-04 21:08:08 -0700366
367 return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
Hannes Frederic Sowaf87c10a2014-01-09 10:01:15 +0100368}
369
Eric Dumazet04ca6972014-07-26 08:58:10 +0200370u32 ip_idents_reserve(u32 hash, int segs);
Hannes Frederic Sowab6a77192015-03-25 17:07:44 +0100371void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
Eric Dumazet73f156a2014-06-02 05:26:03 -0700372
Hannes Frederic Sowab6a77192015-03-25 17:07:44 +0100373static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
374 struct sock *sk, int segs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375{
Ansis Atteka703133d2013-09-18 15:29:53 -0700376 struct iphdr *iph = ip_hdr(skb);
377
WANG Cong60ff7462014-05-04 16:39:18 -0700378 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 /* This is only to work around buggy Windows95/2000
380 * VJ compression implementations. If the ID field
381 * does not change, they drop every other packet in
382 * a TCP stream using header compression.
383 */
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000384 if (sk && inet_sk(sk)->inet_daddr) {
385 iph->id = htons(inet_sk(sk)->inet_id);
Eric Dumazet73f156a2014-06-02 05:26:03 -0700386 inet_sk(sk)->inet_id += segs;
387 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 iph->id = 0;
Eric Dumazet73f156a2014-06-02 05:26:03 -0700389 }
390 } else {
Hannes Frederic Sowab6a77192015-03-25 17:07:44 +0100391 __ip_select_ident(net, iph, segs);
Eric Dumazet73f156a2014-06-02 05:26:03 -0700392 }
393}
394
Hannes Frederic Sowab6a77192015-03-25 17:07:44 +0100395static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
396 struct sock *sk)
Eric Dumazet73f156a2014-06-02 05:26:03 -0700397{
Hannes Frederic Sowab6a77192015-03-25 17:07:44 +0100398 ip_select_ident_segs(net, skb, sk, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399}
400
Tom Herberted70fcf2014-05-02 16:29:38 -0700401static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
402{
403 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
404 skb->len, proto, 0);
405}
406
Tom Herbertc3f83242015-06-04 09:16:40 -0700407/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
408 * Equivalent to : flow->v4addrs.src = iph->saddr;
409 * flow->v4addrs.dst = iph->daddr;
410 */
411static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
412 const struct iphdr *iph)
413{
414 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
415 offsetof(typeof(flow->addrs), v4addrs.src) +
416 sizeof(flow->addrs.v4addrs.src));
417 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
418 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
419}
420
Tom Herbert1933a782014-08-22 13:34:04 -0700421static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
422{
423 const struct iphdr *iph = skb_gro_network_header(skb);
424
425 return csum_tcpudp_nofold(iph->saddr, iph->daddr,
426 skb_gro_len(skb), proto, 0);
427}
428
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429/*
430 * Map a multicast IP onto multicast MAC for type ethernet.
431 */
432
Al Viro714e85b2006-11-14 20:51:49 -0800433static inline void ip_eth_mc_map(__be32 naddr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434{
Al Viro714e85b2006-11-14 20:51:49 -0800435 __u32 addr=ntohl(naddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 buf[0]=0x01;
437 buf[1]=0x00;
438 buf[2]=0x5e;
439 buf[5]=addr&0xFF;
440 addr>>=8;
441 buf[4]=addr&0xFF;
442 addr>>=8;
443 buf[3]=addr&0x7F;
444}
445
446/*
447 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
448 * Leave P_Key as 0 to be filled in by driver.
449 */
450
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700451static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452{
Al Viro714e85b2006-11-14 20:51:49 -0800453 __u32 addr;
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700454 unsigned char scope = broadcast[5] & 0xF;
455
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 buf[0] = 0; /* Reserved */
457 buf[1] = 0xff; /* Multicast QPN */
458 buf[2] = 0xff;
459 buf[3] = 0xff;
Al Viro714e85b2006-11-14 20:51:49 -0800460 addr = ntohl(naddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 buf[4] = 0xff;
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700462 buf[5] = 0x10 | scope; /* scope from broadcast address */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 buf[6] = 0x40; /* IPv4 signature */
464 buf[7] = 0x1b;
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700465 buf[8] = broadcast[8]; /* P_Key */
466 buf[9] = broadcast[9];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 buf[10] = 0;
468 buf[11] = 0;
469 buf[12] = 0;
470 buf[13] = 0;
471 buf[14] = 0;
472 buf[15] = 0;
473 buf[19] = addr & 0xff;
474 addr >>= 8;
475 buf[18] = addr & 0xff;
476 addr >>= 8;
477 buf[17] = addr & 0xff;
478 addr >>= 8;
479 buf[16] = addr & 0x0f;
480}
481
Timo Teräs93ca3bb2011-03-28 22:40:53 +0000482static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
483{
484 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
485 memcpy(buf, broadcast, 4);
486 else
487 memcpy(buf, &naddr, sizeof(naddr));
488}
489
Eric Dumazetdfd56b82011-12-10 09:48:31 +0000490#if IS_ENABLED(CONFIG_IPV6)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491#include <linux/ipv6.h>
492#endif
493
494static __inline__ void inet_reset_saddr(struct sock *sk)
495{
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000496 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
Eric Dumazetdfd56b82011-12-10 09:48:31 +0000497#if IS_ENABLED(CONFIG_IPV6)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 if (sk->sk_family == PF_INET6) {
499 struct ipv6_pinfo *np = inet6_sk(sk);
500
501 memset(&np->saddr, 0, sizeof(np->saddr));
Eric Dumazetefe42082013-10-03 15:42:29 -0700502 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 }
504#endif
505}
506
507#endif
508
David Ahern72afa352015-08-27 16:06:59 -0700509static inline unsigned int ipv4_addr_hash(__be32 ip)
510{
511 return (__force unsigned int) ip;
512}
513
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700514bool ip_call_ra_chain(struct sk_buff *skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515
516/*
Rami Rosenb7982322008-01-01 21:13:09 -0800517 * Functions provided by ip_fragment.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 */
519
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +0000520enum ip_defrag_users {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 IP_DEFRAG_LOCAL_DELIVER,
522 IP_DEFRAG_CALL_RA_CHAIN,
523 IP_DEFRAG_CONNTRACK_IN,
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700524 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 IP_DEFRAG_CONNTRACK_OUT,
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700526 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
Patrick McHardy8fa9ff62009-12-15 16:59:59 +0100527 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700528 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 IP_DEFRAG_VS_IN,
530 IP_DEFRAG_VS_OUT,
David S. Miller595fc712011-07-05 01:05:48 -0700531 IP_DEFRAG_VS_FWD,
532 IP_DEFRAG_AF_PACKET,
Eric Dumazetbc416d92011-10-06 10:28:31 +0000533 IP_DEFRAG_MACVLAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534};
535
Andy Zhou5cf42282015-05-15 14:15:35 -0700536/* Return true if the value of 'user' is between 'lower_bond'
537 * and 'upper_bond' inclusively.
538 */
539static inline bool ip_defrag_user_in_between(u32 user,
540 enum ip_defrag_users lower_bond,
541 enum ip_defrag_users upper_bond)
542{
543 return user >= lower_bond && user <= upper_bond;
544}
545
Eric W. Biederman19bcf9f2015-10-09 13:44:54 -0500546int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
Eric Dumazetbc416d92011-10-06 10:28:31 +0000547#ifdef CONFIG_INET
Eric W. Biederman19bcf9f2015-10-09 13:44:54 -0500548struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
Eric Dumazetbc416d92011-10-06 10:28:31 +0000549#else
Eric W. Biederman19bcf9f2015-10-09 13:44:54 -0500550static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
Eric Dumazetbc416d92011-10-06 10:28:31 +0000551{
552 return skb;
553}
554#endif
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800555int ip_frag_mem(struct net *net);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557/*
558 * Functions provided by ip_forward.c
559 */
560
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700561int ip_forward(struct sk_buff *skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
563/*
564 * Functions provided by ip_options.c
565 */
566
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700567void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
568 __be32 daddr, struct rtable *rt, int is_frag);
Eric Dumazet24a2d432014-09-27 09:50:55 -0700569
570int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
571 const struct ip_options *sopt);
572static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
573{
574 return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
575}
576
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700577void ip_options_fragment(struct sk_buff *skb);
578int ip_options_compile(struct net *net, struct ip_options *opt,
579 struct sk_buff *skb);
580int ip_options_get(struct net *net, struct ip_options_rcu **optp,
581 unsigned char *data, int optlen);
582int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
583 unsigned char __user *data, int optlen);
584void ip_options_undo(struct ip_options *opt);
585void ip_forward_options(struct sk_buff *skb);
586int ip_options_rcv_srr(struct sk_buff *skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588/*
589 * Functions provided by ip_sockglue.c
590 */
591
Shawn Bohrerfbf88662013-10-07 11:01:40 -0500592void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
Paolo Abeniad959032016-11-04 11:28:58 +0100593void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
594 struct sk_buff *skb, int tlen, int offset);
Soheil Hassas Yeganeh24025c42016-04-02 23:08:10 -0400595int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
Hannes Frederic Sowac8e6ad02014-02-18 21:38:08 +0100596 struct ipcm_cookie *ipc, bool allow_ipv6);
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700597int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
598 unsigned int optlen);
599int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
600 int __user *optlen);
601int compat_ip_setsockopt(struct sock *sk, int level, int optname,
602 char __user *optval, unsigned int optlen);
603int compat_ip_getsockopt(struct sock *sk, int level, int optname,
604 char __user *optval, int __user *optlen);
605int ip_ra_control(struct sock *sk, unsigned char on,
606 void (*destructor)(struct sock *));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
Hannes Frederic Sowa85fbaa72013-11-23 00:46:12 +0100608int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700609void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
610 u32 info, u8 *payload);
611void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
612 u32 info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
Tom Herbert5961de92015-01-05 13:56:16 -0800614static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
615{
Paolo Abeniad959032016-11-04 11:28:58 +0100616 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
Tom Herbert5961de92015-01-05 13:56:16 -0800617}
618
Eric Dumazet4cdf5072014-09-19 07:38:40 -0700619bool icmp_global_allow(void);
620extern int sysctl_icmp_msgs_per_sec;
621extern int sysctl_icmp_msgs_burst;
622
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300623#ifdef CONFIG_PROC_FS
Joe Perches5c3a0fd2013-09-21 10:22:42 -0700624int ip_misc_proc_init(void);
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -0300625#endif
626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627#endif /* _IP_H */