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
34 struct sock;
35
36 struct 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
ip_hdrlen(const struct sk_buff * skb)47 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
48 {
49 return ip_hdr(skb)->ihl * 4;
50 }
51
52 struct ipcm_cookie {
53 __be32 addr;
54 int oif;
55 struct ip_options *opt;
56 __u8 tx_flags;
57 };
58
59 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
60
61 struct 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
71 extern 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
81 struct msghdr;
82 struct net_device;
83 struct packet_type;
84 struct rtable;
85 struct sockaddr;
86
87 extern int igmp_mc_proc_init(void);
88
89 /*
90 * Functions provided by ip.c
91 */
92
93 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
94 __be32 saddr, __be32 daddr,
95 struct ip_options *opt);
96 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
97 struct packet_type *pt, struct net_device *orig_dev);
98 extern int ip_local_deliver(struct sk_buff *skb);
99 extern int ip_mr_input(struct sk_buff *skb);
100 extern int ip_output(struct sk_buff *skb);
101 extern int ip_mc_output(struct sk_buff *skb);
102 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
103 extern int ip_do_nat(struct sk_buff *skb);
104 extern void ip_send_check(struct iphdr *ip);
105 extern int __ip_local_out(struct sk_buff *skb);
106 extern int ip_local_out(struct sk_buff *skb);
107 extern int ip_queue_xmit(struct sk_buff *skb);
108 extern void ip_init(void);
109 extern int ip_append_data(struct sock *sk,
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);
116 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
117 extern ssize_t ip_append_page(struct sock *sk, struct page *page,
118 int offset, size_t size, int flags);
119 extern struct sk_buff *__ip_make_skb(struct sock *sk,
120 struct sk_buff_head *queue,
121 struct inet_cork *cork);
122 extern int ip_send_skb(struct sk_buff *skb);
123 extern int ip_push_pending_frames(struct sock *sk);
124 extern void ip_flush_pending_frames(struct sock *sk);
125 extern struct sk_buff *ip_make_skb(struct sock *sk,
126 int getfrag(void *from, char *to, int offset, int len,
127 int odd, struct sk_buff *skb),
128 void *from, int length, int transhdrlen,
129 struct ipcm_cookie *ipc,
130 struct rtable **rtp,
131 unsigned int flags);
132
ip_finish_skb(struct sock * sk)133 static inline struct sk_buff *ip_finish_skb(struct sock *sk)
134 {
135 return __ip_make_skb(sk, &sk->sk_write_queue, &inet_sk(sk)->cork);
136 }
137
138 /* datagram.c */
139 extern int ip4_datagram_connect(struct sock *sk,
140 struct sockaddr *uaddr, int addr_len);
141
142 /*
143 * Map a multicast IP onto multicast MAC for type Token Ring.
144 * This conforms to RFC1469 Option 2 Multicasting i.e.
145 * using a functional address to transmit / receive
146 * multicast packets.
147 */
148
ip_tr_mc_map(__be32 addr,char * buf)149 static inline void ip_tr_mc_map(__be32 addr, char *buf)
150 {
151 buf[0]=0xC0;
152 buf[1]=0x00;
153 buf[2]=0x00;
154 buf[3]=0x04;
155 buf[4]=0x00;
156 buf[5]=0x00;
157 }
158
159 struct 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 };
167
168 #define IP_REPLY_ARG_NOSRCCHECK 1
169
ip_reply_arg_flowi_flags(const struct ip_reply_arg * arg)170 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
171 {
172 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
173 }
174
175 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
176 unsigned int len);
177
178 struct ipv4_config {
179 int log_martians;
180 int no_pmtu_disc;
181 };
182
183 extern struct ipv4_config ipv4_config;
184 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
185 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
186 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
187 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
188 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
189 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
190 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
191 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
192 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
193 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
194 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
195
196 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt);
197 #if BITS_PER_LONG==32
198 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
199 #else
snmp_fold_field64(void __percpu * mib[],int offt,size_t syncp_off)200 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
201 {
202 return snmp_fold_field(mib, offt);
203 }
204 #endif
205 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
206 extern void snmp_mib_free(void __percpu *ptr[2]);
207
208 extern struct local_ports {
209 seqlock_t lock;
210 int range[2];
211 } sysctl_local_ports;
212 extern void inet_get_local_port_range(int *low, int *high);
213
214 extern unsigned long *sysctl_local_reserved_ports;
inet_is_reserved_local_port(int port)215 static inline int inet_is_reserved_local_port(int port)
216 {
217 return test_bit(port, sysctl_local_reserved_ports);
218 }
219
220 extern int sysctl_ip_nonlocal_bind;
221
222 extern struct ctl_path net_core_path[];
223 extern struct ctl_path net_ipv4_ctl_path[];
224
225 /* From inetpeer.c */
226 extern int inet_peer_threshold;
227 extern int inet_peer_minttl;
228 extern int inet_peer_maxttl;
229 extern int inet_peer_gc_mintime;
230 extern int inet_peer_gc_maxtime;
231
232 /* From ip_output.c */
233 extern int sysctl_ip_dynaddr;
234
235 extern void ipfrag_init(void);
236
237 extern void ip_static_sysctl_init(void);
238
239 #ifdef CONFIG_INET
240 #include <net/dst.h>
241
242 /* The function in 2.2 was invalid, producing wrong result for
243 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
244 static inline
ip_decrease_ttl(struct iphdr * iph)245 int ip_decrease_ttl(struct iphdr *iph)
246 {
247 u32 check = (__force u32)iph->check;
248 check += (__force u32)htons(0x0100);
249 iph->check = (__force __sum16)(check + (check>=0xFFFF));
250 return --iph->ttl;
251 }
252
253 static inline
ip_dont_fragment(struct sock * sk,struct dst_entry * dst)254 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
255 {
256 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
257 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
258 !(dst_metric_locked(dst, RTAX_MTU)));
259 }
260
261 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
262
ip_select_ident(struct iphdr * iph,struct dst_entry * dst,struct sock * sk)263 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
264 {
265 if (iph->frag_off & htons(IP_DF)) {
266 /* This is only to work around buggy Windows95/2000
267 * VJ compression implementations. If the ID field
268 * does not change, they drop every other packet in
269 * a TCP stream using header compression.
270 */
271 iph->id = (sk && inet_sk(sk)->inet_daddr) ?
272 htons(inet_sk(sk)->inet_id++) : 0;
273 } else
274 __ip_select_ident(iph, dst, 0);
275 }
276
ip_select_ident_more(struct iphdr * iph,struct dst_entry * dst,struct sock * sk,int more)277 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
278 {
279 if (iph->frag_off & htons(IP_DF)) {
280 if (sk && inet_sk(sk)->inet_daddr) {
281 iph->id = htons(inet_sk(sk)->inet_id);
282 inet_sk(sk)->inet_id += 1 + more;
283 } else
284 iph->id = 0;
285 } else
286 __ip_select_ident(iph, dst, more);
287 }
288
289 /*
290 * Map a multicast IP onto multicast MAC for type ethernet.
291 */
292
ip_eth_mc_map(__be32 naddr,char * buf)293 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
294 {
295 __u32 addr=ntohl(naddr);
296 buf[0]=0x01;
297 buf[1]=0x00;
298 buf[2]=0x5e;
299 buf[5]=addr&0xFF;
300 addr>>=8;
301 buf[4]=addr&0xFF;
302 addr>>=8;
303 buf[3]=addr&0x7F;
304 }
305
306 /*
307 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
308 * Leave P_Key as 0 to be filled in by driver.
309 */
310
ip_ib_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)311 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
312 {
313 __u32 addr;
314 unsigned char scope = broadcast[5] & 0xF;
315
316 buf[0] = 0; /* Reserved */
317 buf[1] = 0xff; /* Multicast QPN */
318 buf[2] = 0xff;
319 buf[3] = 0xff;
320 addr = ntohl(naddr);
321 buf[4] = 0xff;
322 buf[5] = 0x10 | scope; /* scope from broadcast address */
323 buf[6] = 0x40; /* IPv4 signature */
324 buf[7] = 0x1b;
325 buf[8] = broadcast[8]; /* P_Key */
326 buf[9] = broadcast[9];
327 buf[10] = 0;
328 buf[11] = 0;
329 buf[12] = 0;
330 buf[13] = 0;
331 buf[14] = 0;
332 buf[15] = 0;
333 buf[19] = addr & 0xff;
334 addr >>= 8;
335 buf[18] = addr & 0xff;
336 addr >>= 8;
337 buf[17] = addr & 0xff;
338 addr >>= 8;
339 buf[16] = addr & 0x0f;
340 }
341
ip_ipgre_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)342 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
343 {
344 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
345 memcpy(buf, broadcast, 4);
346 else
347 memcpy(buf, &naddr, sizeof(naddr));
348 }
349
350 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
351 #include <linux/ipv6.h>
352 #endif
353
inet_reset_saddr(struct sock * sk)354 static __inline__ void inet_reset_saddr(struct sock *sk)
355 {
356 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
357 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
358 if (sk->sk_family == PF_INET6) {
359 struct ipv6_pinfo *np = inet6_sk(sk);
360
361 memset(&np->saddr, 0, sizeof(np->saddr));
362 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
363 }
364 #endif
365 }
366
367 #endif
368
sk_mc_loop(struct sock * sk)369 static inline int sk_mc_loop(struct sock *sk)
370 {
371 if (!sk)
372 return 1;
373 switch (sk->sk_family) {
374 case AF_INET:
375 return inet_sk(sk)->mc_loop;
376 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
377 case AF_INET6:
378 return inet6_sk(sk)->mc_loop;
379 #endif
380 }
381 WARN_ON(1);
382 return 1;
383 }
384
385 extern int ip_call_ra_chain(struct sk_buff *skb);
386
387 /*
388 * Functions provided by ip_fragment.c
389 */
390
391 enum ip_defrag_users {
392 IP_DEFRAG_LOCAL_DELIVER,
393 IP_DEFRAG_CALL_RA_CHAIN,
394 IP_DEFRAG_CONNTRACK_IN,
395 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
396 IP_DEFRAG_CONNTRACK_OUT,
397 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
398 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
399 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
400 IP_DEFRAG_VS_IN,
401 IP_DEFRAG_VS_OUT,
402 IP_DEFRAG_VS_FWD
403 };
404
405 int ip_defrag(struct sk_buff *skb, u32 user);
406 int ip_frag_mem(struct net *net);
407 int ip_frag_nqueues(struct net *net);
408
409 /*
410 * Functions provided by ip_forward.c
411 */
412
413 extern int ip_forward(struct sk_buff *skb);
414
415 /*
416 * Functions provided by ip_options.c
417 */
418
419 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
420 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
421 extern void ip_options_fragment(struct sk_buff *skb);
422 extern int ip_options_compile(struct net *net,
423 struct ip_options *opt, struct sk_buff *skb);
424 extern int ip_options_get(struct net *net, struct ip_options **optp,
425 unsigned char *data, int optlen);
426 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
427 unsigned char __user *data, int optlen);
428 extern void ip_options_undo(struct ip_options * opt);
429 extern void ip_forward_options(struct sk_buff *skb);
430 extern int ip_options_rcv_srr(struct sk_buff *skb);
431
432 /*
433 * Functions provided by ip_sockglue.c
434 */
435
436 extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
437 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
438 extern int ip_cmsg_send(struct net *net,
439 struct msghdr *msg, struct ipcm_cookie *ipc);
440 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen);
441 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
442 extern int compat_ip_setsockopt(struct sock *sk, int level,
443 int optname, char __user *optval, unsigned int optlen);
444 extern int compat_ip_getsockopt(struct sock *sk, int level,
445 int optname, char __user *optval, int __user *optlen);
446 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
447
448 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
449 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
450 __be16 port, u32 info, u8 *payload);
451 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
452 u32 info);
453
454 #ifdef CONFIG_PROC_FS
455 extern int ip_misc_proc_init(void);
456 #endif
457
458 #endif /* _IP_H */
459