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