ip.h 14 KB

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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. #include <linux/types.h>
  25. #include <linux/ip.h>
  26. #include <linux/in.h>
  27. #include <linux/skbuff.h>
  28. #include <net/inet_sock.h>
  29. #include <net/snmp.h>
  30. #include <net/flow.h>
  31. struct sock;
  32. struct inet_skb_parm {
  33. struct ip_options opt; /* Compiled IP options */
  34. unsigned char flags;
  35. #define IPSKB_FORWARDED 1
  36. #define IPSKB_XFRM_TUNNEL_SIZE 2
  37. #define IPSKB_XFRM_TRANSFORMED 4
  38. #define IPSKB_FRAG_COMPLETE 8
  39. #define IPSKB_REROUTED 16
  40. };
  41. static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
  42. {
  43. return ip_hdr(skb)->ihl * 4;
  44. }
  45. struct ipcm_cookie {
  46. __be32 addr;
  47. int oif;
  48. struct ip_options_rcu *opt;
  49. __u8 tx_flags;
  50. };
  51. #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
  52. struct ip_ra_chain {
  53. struct ip_ra_chain __rcu *next;
  54. struct sock *sk;
  55. union {
  56. void (*destructor)(struct sock *);
  57. struct sock *saved_sk;
  58. };
  59. struct rcu_head rcu;
  60. };
  61. extern struct ip_ra_chain __rcu *ip_ra_chain;
  62. /* IP flags. */
  63. #define IP_CE 0x8000 /* Flag: "Congestion" */
  64. #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
  65. #define IP_MF 0x2000 /* Flag: "More Fragments" */
  66. #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
  67. #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
  68. struct msghdr;
  69. struct net_device;
  70. struct packet_type;
  71. struct rtable;
  72. struct sockaddr;
  73. extern int igmp_mc_proc_init(void);
  74. /*
  75. * Functions provided by ip.c
  76. */
  77. extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
  78. __be32 saddr, __be32 daddr,
  79. struct ip_options_rcu *opt);
  80. extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
  81. struct packet_type *pt, struct net_device *orig_dev);
  82. extern int ip_local_deliver(struct sk_buff *skb);
  83. extern int ip_mr_input(struct sk_buff *skb);
  84. extern int ip_output(struct sk_buff *skb);
  85. extern int ip_mc_output(struct sk_buff *skb);
  86. extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
  87. extern int ip_do_nat(struct sk_buff *skb);
  88. extern void ip_send_check(struct iphdr *ip);
  89. extern int __ip_local_out(struct sk_buff *skb);
  90. extern int ip_local_out(struct sk_buff *skb);
  91. extern int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl);
  92. extern void ip_init(void);
  93. extern int ip_append_data(struct sock *sk, struct flowi4 *fl4,
  94. int getfrag(void *from, char *to, int offset, int len,
  95. int odd, struct sk_buff *skb),
  96. void *from, int len, int protolen,
  97. struct ipcm_cookie *ipc,
  98. struct rtable **rt,
  99. unsigned int flags);
  100. extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
  101. extern ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
  102. int offset, size_t size, int flags);
  103. extern struct sk_buff *__ip_make_skb(struct sock *sk,
  104. struct flowi4 *fl4,
  105. struct sk_buff_head *queue,
  106. struct inet_cork *cork);
  107. extern int ip_send_skb(struct sk_buff *skb);
  108. extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
  109. extern void ip_flush_pending_frames(struct sock *sk);
  110. extern struct sk_buff *ip_make_skb(struct sock *sk,
  111. struct flowi4 *fl4,
  112. int getfrag(void *from, char *to, int offset, int len,
  113. int odd, struct sk_buff *skb),
  114. void *from, int length, int transhdrlen,
  115. struct ipcm_cookie *ipc,
  116. struct rtable **rtp,
  117. unsigned int flags);
  118. static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
  119. {
  120. return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
  121. }
  122. /* datagram.c */
  123. extern int ip4_datagram_connect(struct sock *sk,
  124. struct sockaddr *uaddr, int addr_len);
  125. /*
  126. * Map a multicast IP onto multicast MAC for type Token Ring.
  127. * This conforms to RFC1469 Option 2 Multicasting i.e.
  128. * using a functional address to transmit / receive
  129. * multicast packets.
  130. */
  131. static inline void ip_tr_mc_map(__be32 addr, char *buf)
  132. {
  133. buf[0]=0xC0;
  134. buf[1]=0x00;
  135. buf[2]=0x00;
  136. buf[3]=0x04;
  137. buf[4]=0x00;
  138. buf[5]=0x00;
  139. }
  140. struct ip_reply_arg {
  141. struct kvec iov[1];
  142. int flags;
  143. __wsum csum;
  144. int csumoffset; /* u16 offset of csum in iov[0].iov_base */
  145. /* -1 if not needed */
  146. int bound_dev_if;
  147. };
  148. #define IP_REPLY_ARG_NOSRCCHECK 1
  149. static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
  150. {
  151. return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
  152. }
  153. void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
  154. struct ip_reply_arg *arg, unsigned int len);
  155. struct ipv4_config {
  156. int log_martians;
  157. int no_pmtu_disc;
  158. };
  159. extern struct ipv4_config ipv4_config;
  160. #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
  161. #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
  162. #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
  163. #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
  164. #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
  165. #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
  166. #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
  167. #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
  168. #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
  169. #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
  170. #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
  171. extern unsigned long snmp_fold_field(void __percpu *mib[], int offt);
  172. #if BITS_PER_LONG==32
  173. extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
  174. #else
  175. static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
  176. {
  177. return snmp_fold_field(mib, offt);
  178. }
  179. #endif
  180. extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
  181. extern void snmp_mib_free(void __percpu *ptr[2]);
  182. extern struct local_ports {
  183. seqlock_t lock;
  184. int range[2];
  185. } sysctl_local_ports;
  186. extern void inet_get_local_port_range(int *low, int *high);
  187. extern unsigned long *sysctl_local_reserved_ports;
  188. static inline int inet_is_reserved_local_port(int port)
  189. {
  190. return test_bit(port, sysctl_local_reserved_ports);
  191. }
  192. extern int sysctl_ip_nonlocal_bind;
  193. extern struct ctl_path net_core_path[];
  194. extern struct ctl_path net_ipv4_ctl_path[];
  195. /* From inetpeer.c */
  196. extern int inet_peer_threshold;
  197. extern int inet_peer_minttl;
  198. extern int inet_peer_maxttl;
  199. extern int inet_peer_gc_mintime;
  200. extern int inet_peer_gc_maxtime;
  201. /* From ip_output.c */
  202. extern int sysctl_ip_dynaddr;
  203. extern void ipfrag_init(void);
  204. extern void ip_static_sysctl_init(void);
  205. #ifdef CONFIG_INET
  206. #include <net/dst.h>
  207. /* The function in 2.2 was invalid, producing wrong result for
  208. * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
  209. static inline
  210. int ip_decrease_ttl(struct iphdr *iph)
  211. {
  212. u32 check = (__force u32)iph->check;
  213. check += (__force u32)htons(0x0100);
  214. iph->check = (__force __sum16)(check + (check>=0xFFFF));
  215. return --iph->ttl;
  216. }
  217. static inline
  218. int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
  219. {
  220. return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
  221. (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
  222. !(dst_metric_locked(dst, RTAX_MTU)));
  223. }
  224. extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
  225. static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
  226. {
  227. if (iph->frag_off & htons(IP_DF)) {
  228. /* This is only to work around buggy Windows95/2000
  229. * VJ compression implementations. If the ID field
  230. * does not change, they drop every other packet in
  231. * a TCP stream using header compression.
  232. */
  233. iph->id = (sk && inet_sk(sk)->inet_daddr) ?
  234. htons(inet_sk(sk)->inet_id++) : 0;
  235. } else
  236. __ip_select_ident(iph, dst, 0);
  237. }
  238. static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
  239. {
  240. if (iph->frag_off & htons(IP_DF)) {
  241. if (sk && inet_sk(sk)->inet_daddr) {
  242. iph->id = htons(inet_sk(sk)->inet_id);
  243. inet_sk(sk)->inet_id += 1 + more;
  244. } else
  245. iph->id = 0;
  246. } else
  247. __ip_select_ident(iph, dst, more);
  248. }
  249. /*
  250. * Map a multicast IP onto multicast MAC for type ethernet.
  251. */
  252. static inline void ip_eth_mc_map(__be32 naddr, char *buf)
  253. {
  254. __u32 addr=ntohl(naddr);
  255. buf[0]=0x01;
  256. buf[1]=0x00;
  257. buf[2]=0x5e;
  258. buf[5]=addr&0xFF;
  259. addr>>=8;
  260. buf[4]=addr&0xFF;
  261. addr>>=8;
  262. buf[3]=addr&0x7F;
  263. }
  264. /*
  265. * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
  266. * Leave P_Key as 0 to be filled in by driver.
  267. */
  268. static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
  269. {
  270. __u32 addr;
  271. unsigned char scope = broadcast[5] & 0xF;
  272. buf[0] = 0; /* Reserved */
  273. buf[1] = 0xff; /* Multicast QPN */
  274. buf[2] = 0xff;
  275. buf[3] = 0xff;
  276. addr = ntohl(naddr);
  277. buf[4] = 0xff;
  278. buf[5] = 0x10 | scope; /* scope from broadcast address */
  279. buf[6] = 0x40; /* IPv4 signature */
  280. buf[7] = 0x1b;
  281. buf[8] = broadcast[8]; /* P_Key */
  282. buf[9] = broadcast[9];
  283. buf[10] = 0;
  284. buf[11] = 0;
  285. buf[12] = 0;
  286. buf[13] = 0;
  287. buf[14] = 0;
  288. buf[15] = 0;
  289. buf[19] = addr & 0xff;
  290. addr >>= 8;
  291. buf[18] = addr & 0xff;
  292. addr >>= 8;
  293. buf[17] = addr & 0xff;
  294. addr >>= 8;
  295. buf[16] = addr & 0x0f;
  296. }
  297. static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
  298. {
  299. if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
  300. memcpy(buf, broadcast, 4);
  301. else
  302. memcpy(buf, &naddr, sizeof(naddr));
  303. }
  304. #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  305. #include <linux/ipv6.h>
  306. #endif
  307. static __inline__ void inet_reset_saddr(struct sock *sk)
  308. {
  309. inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
  310. #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  311. if (sk->sk_family == PF_INET6) {
  312. struct ipv6_pinfo *np = inet6_sk(sk);
  313. memset(&np->saddr, 0, sizeof(np->saddr));
  314. memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
  315. }
  316. #endif
  317. }
  318. #endif
  319. static inline int sk_mc_loop(struct sock *sk)
  320. {
  321. if (!sk)
  322. return 1;
  323. switch (sk->sk_family) {
  324. case AF_INET:
  325. return inet_sk(sk)->mc_loop;
  326. #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  327. case AF_INET6:
  328. return inet6_sk(sk)->mc_loop;
  329. #endif
  330. }
  331. WARN_ON(1);
  332. return 1;
  333. }
  334. extern int ip_call_ra_chain(struct sk_buff *skb);
  335. /*
  336. * Functions provided by ip_fragment.c
  337. */
  338. enum ip_defrag_users {
  339. IP_DEFRAG_LOCAL_DELIVER,
  340. IP_DEFRAG_CALL_RA_CHAIN,
  341. IP_DEFRAG_CONNTRACK_IN,
  342. __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
  343. IP_DEFRAG_CONNTRACK_OUT,
  344. __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
  345. IP_DEFRAG_CONNTRACK_BRIDGE_IN,
  346. __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
  347. IP_DEFRAG_VS_IN,
  348. IP_DEFRAG_VS_OUT,
  349. IP_DEFRAG_VS_FWD
  350. };
  351. int ip_defrag(struct sk_buff *skb, u32 user);
  352. int ip_frag_mem(struct net *net);
  353. int ip_frag_nqueues(struct net *net);
  354. /*
  355. * Functions provided by ip_forward.c
  356. */
  357. extern int ip_forward(struct sk_buff *skb);
  358. /*
  359. * Functions provided by ip_options.c
  360. */
  361. extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
  362. __be32 daddr, struct rtable *rt, int is_frag);
  363. extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
  364. extern void ip_options_fragment(struct sk_buff *skb);
  365. extern int ip_options_compile(struct net *net,
  366. struct ip_options *opt, struct sk_buff *skb);
  367. extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
  368. unsigned char *data, int optlen);
  369. extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
  370. unsigned char __user *data, int optlen);
  371. extern void ip_options_undo(struct ip_options * opt);
  372. extern void ip_forward_options(struct sk_buff *skb);
  373. extern int ip_options_rcv_srr(struct sk_buff *skb);
  374. /*
  375. * Functions provided by ip_sockglue.c
  376. */
  377. extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
  378. extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
  379. extern int ip_cmsg_send(struct net *net,
  380. struct msghdr *msg, struct ipcm_cookie *ipc);
  381. extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen);
  382. extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
  383. extern int compat_ip_setsockopt(struct sock *sk, int level,
  384. int optname, char __user *optval, unsigned int optlen);
  385. extern int compat_ip_getsockopt(struct sock *sk, int level,
  386. int optname, char __user *optval, int __user *optlen);
  387. extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
  388. extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
  389. extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
  390. __be16 port, u32 info, u8 *payload);
  391. extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
  392. u32 info);
  393. #ifdef CONFIG_PROC_FS
  394. extern int ip_misc_proc_init(void);
  395. #endif
  396. #endif /* _IP_H */