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1/*
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 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <[email protected]>
12 * Alan Cox, <[email protected]>
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
25#include <linux/types.h>
26#include <linux/ip.h>
27#include <linux/in.h>
28#include <linux/skbuff.h>
29
30#include <net/inet_sock.h>
31#include <net/route.h>
32#include <net/snmp.h>
33#include <net/flow.h>
34
35struct sock;
36
37struct inet_skb_parm {
38 struct ip_options opt; /* Compiled IP options */
39 unsigned char flags;
40
41#define IPSKB_FORWARDED 1
42#define IPSKB_XFRM_TUNNEL_SIZE 2
43#define IPSKB_XFRM_TRANSFORMED 4
44#define IPSKB_FRAG_COMPLETE 8
45#define IPSKB_REROUTED 16
46
47 u16 frag_max_size;
48};
49
50static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
51{
52 return ip_hdr(skb)->ihl * 4;
53}
54
55struct ipcm_cookie {
56 __be32 addr;
57 int oif;
58 struct ip_options_rcu *opt;
59 __u8 tx_flags;
60 __u8 ttl;
61 __s16 tos;
62 char priority;
63};
64
65#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
66
67struct ip_ra_chain {
68 struct ip_ra_chain __rcu *next;
69 struct sock *sk;
70 union {
71 void (*destructor)(struct sock *);
72 struct sock *saved_sk;
73 };
74 struct rcu_head rcu;
75};
76
77extern struct ip_ra_chain __rcu *ip_ra_chain;
78
79/* IP flags. */
80#define IP_CE 0x8000 /* Flag: "Congestion" */
81#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
82#define IP_MF 0x2000 /* Flag: "More Fragments" */
83#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
84
85#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
86
87struct msghdr;
88struct net_device;
89struct packet_type;
90struct rtable;
91struct sockaddr;
92
93int igmp_mc_proc_init(void);
94
95/*
96 * Functions provided by ip.c
97 */
98
99int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
100 __be32 saddr, __be32 daddr,
101 struct ip_options_rcu *opt);
102int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
103 struct net_device *orig_dev);
104int ip_local_deliver(struct sk_buff *skb);
105int ip_mr_input(struct sk_buff *skb);
106int ip_output(struct sk_buff *skb);
107int ip_mc_output(struct sk_buff *skb);
108int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
109int ip_do_nat(struct sk_buff *skb);
110void ip_send_check(struct iphdr *ip);
111int __ip_local_out(struct sk_buff *skb);
112int ip_local_out(struct sk_buff *skb);
113int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl);
114void ip_init(void);
115int ip_append_data(struct sock *sk, struct flowi4 *fl4,
116 int getfrag(void *from, char *to, int offset, int len,
117 int odd, struct sk_buff *skb),
118 void *from, int len, int protolen,
119 struct ipcm_cookie *ipc,
120 struct rtable **rt,
121 unsigned int flags);
122int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
123 struct sk_buff *skb);
124ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
125 int offset, size_t size, int flags);
126struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
127 struct sk_buff_head *queue,
128 struct inet_cork *cork);
129int ip_send_skb(struct net *net, struct sk_buff *skb);
130int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
131void ip_flush_pending_frames(struct sock *sk);
132struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
133 int getfrag(void *from, char *to, int offset,
134 int len, int odd, struct sk_buff *skb),
135 void *from, int length, int transhdrlen,
136 struct ipcm_cookie *ipc, struct rtable **rtp,
137 unsigned int flags);
138
139static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
140{
141 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
142}
143
144static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
145{
146 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
147}
148
149static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
150{
151 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
152}
153
154/* datagram.c */
155int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
156
157void ip4_datagram_release_cb(struct sock *sk);
158
159struct ip_reply_arg {
160 struct kvec iov[1];
161 int flags;
162 __wsum csum;
163 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
164 /* -1 if not needed */
165 int bound_dev_if;
166 u8 tos;
167};
168
169#define IP_REPLY_ARG_NOSRCCHECK 1
170
171static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
172{
173 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
174}
175
176void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
177 __be32 saddr, const struct ip_reply_arg *arg,
178 unsigned int len);
179
180struct ipv4_config {
181 int log_martians;
182 int no_pmtu_disc;
183};
184
185extern struct ipv4_config ipv4_config;
186#define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
187#define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
188#define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
189#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
190#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
191#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
192#define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
193#define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
194#define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
195#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
196#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
197
198unsigned long snmp_fold_field(void __percpu *mib[], int offt);
199#if BITS_PER_LONG==32
200u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
201#else
202static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
203{
204 return snmp_fold_field(mib, offt);
205}
206#endif
207int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
208
209static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
210{
211 int i;
212
213 BUG_ON(ptr == NULL);
214 for (i = 0; i < SNMP_ARRAY_SZ; i++) {
215 free_percpu(ptr[i]);
216 ptr[i] = NULL;
217 }
218}
219
220void inet_get_local_port_range(struct net *net, int *low, int *high);
221
222extern unsigned long *sysctl_local_reserved_ports;
223static inline int inet_is_reserved_local_port(int port)
224{
225 return test_bit(port, sysctl_local_reserved_ports);
226}
227
228extern int sysctl_ip_nonlocal_bind;
229
230/* From inetpeer.c */
231extern int inet_peer_threshold;
232extern int inet_peer_minttl;
233extern int inet_peer_maxttl;
234
235/* From ip_input.c */
236extern int sysctl_ip_early_demux;
237
238/* From ip_output.c */
239extern int sysctl_ip_dynaddr;
240
241void ipfrag_init(void);
242
243void ip_static_sysctl_init(void);
244
245static inline bool ip_is_fragment(const struct iphdr *iph)
246{
247 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
248}
249
250#ifdef CONFIG_INET
251#include <net/dst.h>
252
253/* The function in 2.2 was invalid, producing wrong result for
254 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
255static inline
256int ip_decrease_ttl(struct iphdr *iph)
257{
258 u32 check = (__force u32)iph->check;
259 check += (__force u32)htons(0x0100);
260 iph->check = (__force __sum16)(check + (check>=0xFFFF));
261 return --iph->ttl;
262}
263
264static inline
265int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
266{
267 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
268 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
269 !(dst_metric_locked(dst, RTAX_MTU)));
270}
271
272void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
273
274static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk)
275{
276 struct iphdr *iph = ip_hdr(skb);
277
278 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
279 /* This is only to work around buggy Windows95/2000
280 * VJ compression implementations. If the ID field
281 * does not change, they drop every other packet in
282 * a TCP stream using header compression.
283 */
284 iph->id = (sk && inet_sk(sk)->inet_daddr) ?
285 htons(inet_sk(sk)->inet_id++) : 0;
286 } else
287 __ip_select_ident(iph, dst, 0);
288}
289
290static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more)
291{
292 struct iphdr *iph = ip_hdr(skb);
293
294 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
295 if (sk && inet_sk(sk)->inet_daddr) {
296 iph->id = htons(inet_sk(sk)->inet_id);
297 inet_sk(sk)->inet_id += 1 + more;
298 } else
299 iph->id = 0;
300 } else
301 __ip_select_ident(iph, dst, more);
302}
303
304/*
305 * Map a multicast IP onto multicast MAC for type ethernet.
306 */
307
308static inline void ip_eth_mc_map(__be32 naddr, char *buf)
309{
310 __u32 addr=ntohl(naddr);
311 buf[0]=0x01;
312 buf[1]=0x00;
313 buf[2]=0x5e;
314 buf[5]=addr&0xFF;
315 addr>>=8;
316 buf[4]=addr&0xFF;
317 addr>>=8;
318 buf[3]=addr&0x7F;
319}
320
321/*
322 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
323 * Leave P_Key as 0 to be filled in by driver.
324 */
325
326static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
327{
328 __u32 addr;
329 unsigned char scope = broadcast[5] & 0xF;
330
331 buf[0] = 0; /* Reserved */
332 buf[1] = 0xff; /* Multicast QPN */
333 buf[2] = 0xff;
334 buf[3] = 0xff;
335 addr = ntohl(naddr);
336 buf[4] = 0xff;
337 buf[5] = 0x10 | scope; /* scope from broadcast address */
338 buf[6] = 0x40; /* IPv4 signature */
339 buf[7] = 0x1b;
340 buf[8] = broadcast[8]; /* P_Key */
341 buf[9] = broadcast[9];
342 buf[10] = 0;
343 buf[11] = 0;
344 buf[12] = 0;
345 buf[13] = 0;
346 buf[14] = 0;
347 buf[15] = 0;
348 buf[19] = addr & 0xff;
349 addr >>= 8;
350 buf[18] = addr & 0xff;
351 addr >>= 8;
352 buf[17] = addr & 0xff;
353 addr >>= 8;
354 buf[16] = addr & 0x0f;
355}
356
357static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
358{
359 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
360 memcpy(buf, broadcast, 4);
361 else
362 memcpy(buf, &naddr, sizeof(naddr));
363}
364
365#if IS_ENABLED(CONFIG_IPV6)
366#include <linux/ipv6.h>
367#endif
368
369static __inline__ void inet_reset_saddr(struct sock *sk)
370{
371 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
372#if IS_ENABLED(CONFIG_IPV6)
373 if (sk->sk_family == PF_INET6) {
374 struct ipv6_pinfo *np = inet6_sk(sk);
375
376 memset(&np->saddr, 0, sizeof(np->saddr));
377 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
378 }
379#endif
380}
381
382#endif
383
384static inline int sk_mc_loop(struct sock *sk)
385{
386 if (!sk)
387 return 1;
388 switch (sk->sk_family) {
389 case AF_INET:
390 return inet_sk(sk)->mc_loop;
391#if IS_ENABLED(CONFIG_IPV6)
392 case AF_INET6:
393 return inet6_sk(sk)->mc_loop;
394#endif
395 }
396 WARN_ON(1);
397 return 1;
398}
399
400bool ip_call_ra_chain(struct sk_buff *skb);
401
402/*
403 * Functions provided by ip_fragment.c
404 */
405
406enum ip_defrag_users {
407 IP_DEFRAG_LOCAL_DELIVER,
408 IP_DEFRAG_CALL_RA_CHAIN,
409 IP_DEFRAG_CONNTRACK_IN,
410 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
411 IP_DEFRAG_CONNTRACK_OUT,
412 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
413 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
414 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
415 IP_DEFRAG_VS_IN,
416 IP_DEFRAG_VS_OUT,
417 IP_DEFRAG_VS_FWD,
418 IP_DEFRAG_AF_PACKET,
419 IP_DEFRAG_MACVLAN,
420};
421
422int ip_defrag(struct sk_buff *skb, u32 user);
423#ifdef CONFIG_INET
424struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);
425#else
426static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
427{
428 return skb;
429}
430#endif
431int ip_frag_mem(struct net *net);
432int ip_frag_nqueues(struct net *net);
433
434/*
435 * Functions provided by ip_forward.c
436 */
437
438int ip_forward(struct sk_buff *skb);
439
440/*
441 * Functions provided by ip_options.c
442 */
443
444void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
445 __be32 daddr, struct rtable *rt, int is_frag);
446int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
447void ip_options_fragment(struct sk_buff *skb);
448int ip_options_compile(struct net *net, struct ip_options *opt,
449 struct sk_buff *skb);
450int ip_options_get(struct net *net, struct ip_options_rcu **optp,
451 unsigned char *data, int optlen);
452int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
453 unsigned char __user *data, int optlen);
454void ip_options_undo(struct ip_options *opt);
455void ip_forward_options(struct sk_buff *skb);
456int ip_options_rcv_srr(struct sk_buff *skb);
457
458/*
459 * Functions provided by ip_sockglue.c
460 */
461
462void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
463void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
464int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc);
465int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
466 unsigned int optlen);
467int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
468 int __user *optlen);
469int compat_ip_setsockopt(struct sock *sk, int level, int optname,
470 char __user *optval, unsigned int optlen);
471int compat_ip_getsockopt(struct sock *sk, int level, int optname,
472 char __user *optval, int __user *optlen);
473int ip_ra_control(struct sock *sk, unsigned char on,
474 void (*destructor)(struct sock *));
475
476int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
477void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
478 u32 info, u8 *payload);
479void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
480 u32 info);
481
482#ifdef CONFIG_PROC_FS
483int ip_misc_proc_init(void);
484#endif
485
486#endif /* _IP_H */