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 *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); 132 133 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 */ 148 149 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 1 169 170 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 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; 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 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 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); 262 263 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 } 276 277 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 */ 292 293 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 */ 310 311 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 } 341 342 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 343 #include <linux/ipv6.h> 344 #endif 345 346 static __inline__ void inet_reset_saddr(struct sock *sk) 347 { 348 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 349 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 350 if (sk->sk_family == PF_INET6) { 351 struct ipv6_pinfo *np = inet6_sk(sk); 352 353 memset(&np->saddr, 0, sizeof(np->saddr)); 354 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 355 } 356 #endif 357 } 358 359 #endif 360 361 static inline int sk_mc_loop(struct sock *sk) 362 { 363 if (!sk) 364 return 1; 365 switch (sk->sk_family) { 366 case AF_INET: 367 return inet_sk(sk)->mc_loop; 368 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 369 case AF_INET6: 370 return inet6_sk(sk)->mc_loop; 371 #endif 372 } 373 WARN_ON(1); 374 return 1; 375 } 376 377 extern int ip_call_ra_chain(struct sk_buff *skb); 378 379 /* 380 * Functions provided by ip_fragment.c 381 */ 382 383 enum ip_defrag_users { 384 IP_DEFRAG_LOCAL_DELIVER, 385 IP_DEFRAG_CALL_RA_CHAIN, 386 IP_DEFRAG_CONNTRACK_IN, 387 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 388 IP_DEFRAG_CONNTRACK_OUT, 389 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 390 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 391 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 392 IP_DEFRAG_VS_IN, 393 IP_DEFRAG_VS_OUT, 394 IP_DEFRAG_VS_FWD 395 }; 396 397 int ip_defrag(struct sk_buff *skb, u32 user); 398 int ip_frag_mem(struct net *net); 399 int ip_frag_nqueues(struct net *net); 400 401 /* 402 * Functions provided by ip_forward.c 403 */ 404 405 extern int ip_forward(struct sk_buff *skb); 406 407 /* 408 * Functions provided by ip_options.c 409 */ 410 411 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 412 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 413 extern void ip_options_fragment(struct sk_buff *skb); 414 extern int ip_options_compile(struct net *net, 415 struct ip_options *opt, struct sk_buff *skb); 416 extern int ip_options_get(struct net *net, struct ip_options **optp, 417 unsigned char *data, int optlen); 418 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 419 unsigned char __user *data, int optlen); 420 extern void ip_options_undo(struct ip_options * opt); 421 extern void ip_forward_options(struct sk_buff *skb); 422 extern int ip_options_rcv_srr(struct sk_buff *skb); 423 424 /* 425 * Functions provided by ip_sockglue.c 426 */ 427 428 extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 429 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 430 extern int ip_cmsg_send(struct net *net, 431 struct msghdr *msg, struct ipcm_cookie *ipc); 432 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 433 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 434 extern int compat_ip_setsockopt(struct sock *sk, int level, 435 int optname, char __user *optval, unsigned int optlen); 436 extern int compat_ip_getsockopt(struct sock *sk, int level, 437 int optname, char __user *optval, int __user *optlen); 438 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 439 440 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 441 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 442 __be16 port, u32 info, u8 *payload); 443 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 444 u32 info); 445 446 #ifdef CONFIG_PROC_FS 447 extern int ip_misc_proc_init(void); 448 #endif 449 450 #endif /* _IP_H */ 451