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 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_rcu *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_rcu *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, struct flowi *fl); 108 extern void ip_init(void); 109 extern 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); 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 flowi4 *fl4, struct page *page, 118 int offset, size_t size, int flags); 119 extern struct sk_buff *__ip_make_skb(struct sock *sk, 120 struct flowi4 *fl4, 121 struct sk_buff_head *queue, 122 struct inet_cork *cork); 123 extern int ip_send_skb(struct sk_buff *skb); 124 extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 125 extern void ip_flush_pending_frames(struct sock *sk); 126 extern 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); 134 135 static 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 */ 141 extern int ip4_datagram_connect(struct sock *sk, 142 struct sockaddr *uaddr, int addr_len); 143 144 /* 145 * Map a multicast IP onto multicast MAC for type Token Ring. 146 * This conforms to RFC1469 Option 2 Multicasting i.e. 147 * using a functional address to transmit / receive 148 * multicast packets. 149 */ 150 151 static inline void ip_tr_mc_map(__be32 addr, char *buf) 152 { 153 buf[0]=0xC0; 154 buf[1]=0x00; 155 buf[2]=0x00; 156 buf[3]=0x04; 157 buf[4]=0x00; 158 buf[5]=0x00; 159 } 160 161 struct ip_reply_arg { 162 struct kvec iov[1]; 163 int flags; 164 __wsum csum; 165 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 166 /* -1 if not needed */ 167 int bound_dev_if; 168 }; 169 170 #define IP_REPLY_ARG_NOSRCCHECK 1 171 172 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 173 { 174 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 175 } 176 177 void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr, 178 struct ip_reply_arg *arg, unsigned int len); 179 180 struct ipv4_config { 181 int log_martians; 182 int no_pmtu_disc; 183 }; 184 185 extern 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) 197 198 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt); 199 #if BITS_PER_LONG==32 200 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 201 #else 202 static 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 207 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 208 extern void snmp_mib_free(void __percpu *ptr[2]); 209 210 extern struct local_ports { 211 seqlock_t lock; 212 int range[2]; 213 } sysctl_local_ports; 214 extern void inet_get_local_port_range(int *low, int *high); 215 216 extern unsigned long *sysctl_local_reserved_ports; 217 static inline int inet_is_reserved_local_port(int port) 218 { 219 return test_bit(port, sysctl_local_reserved_ports); 220 } 221 222 extern int sysctl_ip_nonlocal_bind; 223 224 extern struct ctl_path net_core_path[]; 225 extern struct ctl_path net_ipv4_ctl_path[]; 226 227 /* From inetpeer.c */ 228 extern int inet_peer_threshold; 229 extern int inet_peer_minttl; 230 extern int inet_peer_maxttl; 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 static inline bool ip_is_fragment(const struct iphdr *iph) 240 { 241 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 242 } 243 244 #ifdef CONFIG_INET 245 #include <net/dst.h> 246 247 /* The function in 2.2 was invalid, producing wrong result for 248 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 249 static inline 250 int ip_decrease_ttl(struct iphdr *iph) 251 { 252 u32 check = (__force u32)iph->check; 253 check += (__force u32)htons(0x0100); 254 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 255 return --iph->ttl; 256 } 257 258 static inline 259 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 260 { 261 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 262 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 263 !(dst_metric_locked(dst, RTAX_MTU))); 264 } 265 266 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 267 268 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 269 { 270 if (iph->frag_off & htons(IP_DF)) { 271 /* This is only to work around buggy Windows95/2000 272 * VJ compression implementations. If the ID field 273 * does not change, they drop every other packet in 274 * a TCP stream using header compression. 275 */ 276 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 277 htons(inet_sk(sk)->inet_id++) : 0; 278 } else 279 __ip_select_ident(iph, dst, 0); 280 } 281 282 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 283 { 284 if (iph->frag_off & htons(IP_DF)) { 285 if (sk && inet_sk(sk)->inet_daddr) { 286 iph->id = htons(inet_sk(sk)->inet_id); 287 inet_sk(sk)->inet_id += 1 + more; 288 } else 289 iph->id = 0; 290 } else 291 __ip_select_ident(iph, dst, more); 292 } 293 294 /* 295 * Map a multicast IP onto multicast MAC for type ethernet. 296 */ 297 298 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 299 { 300 __u32 addr=ntohl(naddr); 301 buf[0]=0x01; 302 buf[1]=0x00; 303 buf[2]=0x5e; 304 buf[5]=addr&0xFF; 305 addr>>=8; 306 buf[4]=addr&0xFF; 307 addr>>=8; 308 buf[3]=addr&0x7F; 309 } 310 311 /* 312 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 313 * Leave P_Key as 0 to be filled in by driver. 314 */ 315 316 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 317 { 318 __u32 addr; 319 unsigned char scope = broadcast[5] & 0xF; 320 321 buf[0] = 0; /* Reserved */ 322 buf[1] = 0xff; /* Multicast QPN */ 323 buf[2] = 0xff; 324 buf[3] = 0xff; 325 addr = ntohl(naddr); 326 buf[4] = 0xff; 327 buf[5] = 0x10 | scope; /* scope from broadcast address */ 328 buf[6] = 0x40; /* IPv4 signature */ 329 buf[7] = 0x1b; 330 buf[8] = broadcast[8]; /* P_Key */ 331 buf[9] = broadcast[9]; 332 buf[10] = 0; 333 buf[11] = 0; 334 buf[12] = 0; 335 buf[13] = 0; 336 buf[14] = 0; 337 buf[15] = 0; 338 buf[19] = addr & 0xff; 339 addr >>= 8; 340 buf[18] = addr & 0xff; 341 addr >>= 8; 342 buf[17] = addr & 0xff; 343 addr >>= 8; 344 buf[16] = addr & 0x0f; 345 } 346 347 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 348 { 349 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 350 memcpy(buf, broadcast, 4); 351 else 352 memcpy(buf, &naddr, sizeof(naddr)); 353 } 354 355 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 356 #include <linux/ipv6.h> 357 #endif 358 359 static __inline__ void inet_reset_saddr(struct sock *sk) 360 { 361 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 362 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 363 if (sk->sk_family == PF_INET6) { 364 struct ipv6_pinfo *np = inet6_sk(sk); 365 366 memset(&np->saddr, 0, sizeof(np->saddr)); 367 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 368 } 369 #endif 370 } 371 372 #endif 373 374 static inline int sk_mc_loop(struct sock *sk) 375 { 376 if (!sk) 377 return 1; 378 switch (sk->sk_family) { 379 case AF_INET: 380 return inet_sk(sk)->mc_loop; 381 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 382 case AF_INET6: 383 return inet6_sk(sk)->mc_loop; 384 #endif 385 } 386 WARN_ON(1); 387 return 1; 388 } 389 390 extern int ip_call_ra_chain(struct sk_buff *skb); 391 392 /* 393 * Functions provided by ip_fragment.c 394 */ 395 396 enum ip_defrag_users { 397 IP_DEFRAG_LOCAL_DELIVER, 398 IP_DEFRAG_CALL_RA_CHAIN, 399 IP_DEFRAG_CONNTRACK_IN, 400 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 401 IP_DEFRAG_CONNTRACK_OUT, 402 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 403 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 404 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 405 IP_DEFRAG_VS_IN, 406 IP_DEFRAG_VS_OUT, 407 IP_DEFRAG_VS_FWD, 408 IP_DEFRAG_AF_PACKET, 409 }; 410 411 int ip_defrag(struct sk_buff *skb, u32 user); 412 int ip_frag_mem(struct net *net); 413 int ip_frag_nqueues(struct net *net); 414 415 /* 416 * Functions provided by ip_forward.c 417 */ 418 419 extern int ip_forward(struct sk_buff *skb); 420 421 /* 422 * Functions provided by ip_options.c 423 */ 424 425 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 426 __be32 daddr, struct rtable *rt, int is_frag); 427 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 428 extern void ip_options_fragment(struct sk_buff *skb); 429 extern int ip_options_compile(struct net *net, 430 struct ip_options *opt, struct sk_buff *skb); 431 extern int ip_options_get(struct net *net, struct ip_options_rcu **optp, 432 unsigned char *data, int optlen); 433 extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 434 unsigned char __user *data, int optlen); 435 extern void ip_options_undo(struct ip_options * opt); 436 extern void ip_forward_options(struct sk_buff *skb); 437 extern int ip_options_rcv_srr(struct sk_buff *skb); 438 439 /* 440 * Functions provided by ip_sockglue.c 441 */ 442 443 extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 444 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 445 extern int ip_cmsg_send(struct net *net, 446 struct msghdr *msg, struct ipcm_cookie *ipc); 447 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 448 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 449 extern int compat_ip_setsockopt(struct sock *sk, int level, 450 int optname, char __user *optval, unsigned int optlen); 451 extern int compat_ip_getsockopt(struct sock *sk, int level, 452 int optname, char __user *optval, int __user *optlen); 453 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 454 455 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 456 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 457 __be16 port, u32 info, u8 *payload); 458 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 459 u32 info); 460 461 #ifdef CONFIG_PROC_FS 462 extern int ip_misc_proc_init(void); 463 #endif 464 465 #endif /* _IP_H */ 466