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, <[email protected]> 12 * Alan Cox, <[email protected]> 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 union skb_shared_tx shtx; 57 }; 58 59 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 60 61 struct ip_ra_chain { 62 struct ip_ra_chain *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 *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 int ip_push_pending_frames(struct sock *sk); 120 extern void ip_flush_pending_frames(struct sock *sk); 121 122 /* datagram.c */ 123 extern int ip4_datagram_connect(struct sock *sk, 124 struct sockaddr *uaddr, int addr_len); 125 126 /* 127 * Map a multicast IP onto multicast MAC for type Token Ring. 128 * This conforms to RFC1469 Option 2 Multicasting i.e. 129 * using a functional address to transmit / receive 130 * multicast packets. 131 */ 132 133 static inline void ip_tr_mc_map(__be32 addr, char *buf) 134 { 135 buf[0]=0xC0; 136 buf[1]=0x00; 137 buf[2]=0x00; 138 buf[3]=0x04; 139 buf[4]=0x00; 140 buf[5]=0x00; 141 } 142 143 struct ip_reply_arg { 144 struct kvec iov[1]; 145 int flags; 146 __wsum csum; 147 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 148 /* -1 if not needed */ 149 int bound_dev_if; 150 }; 151 152 #define IP_REPLY_ARG_NOSRCCHECK 1 153 154 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 155 { 156 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 157 } 158 159 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 160 unsigned int len); 161 162 struct ipv4_config { 163 int log_martians; 164 int no_pmtu_disc; 165 }; 166 167 extern struct ipv4_config ipv4_config; 168 #define IP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.ip_statistics, field) 169 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.ip_statistics, field) 170 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.ip_statistics, field, val) 171 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS_BH((net)->mib.ip_statistics, field, val) 172 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS((net)->mib.ip_statistics, field, val) 173 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS_BH((net)->mib.ip_statistics, field, val) 174 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 175 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 176 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 177 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 178 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 179 180 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt); 181 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 182 extern void snmp_mib_free(void __percpu *ptr[2]); 183 184 extern struct local_ports { 185 seqlock_t lock; 186 int range[2]; 187 } sysctl_local_ports; 188 extern void inet_get_local_port_range(int *low, int *high); 189 190 extern unsigned long *sysctl_local_reserved_ports; 191 static inline int inet_is_reserved_local_port(int port) 192 { 193 return test_bit(port, sysctl_local_reserved_ports); 194 } 195 196 extern int sysctl_ip_default_ttl; 197 extern int sysctl_ip_nonlocal_bind; 198 199 extern struct ctl_path net_core_path[]; 200 extern struct ctl_path net_ipv4_ctl_path[]; 201 202 /* From inetpeer.c */ 203 extern int inet_peer_threshold; 204 extern int inet_peer_minttl; 205 extern int inet_peer_maxttl; 206 extern int inet_peer_gc_mintime; 207 extern int inet_peer_gc_maxtime; 208 209 /* From ip_output.c */ 210 extern int sysctl_ip_dynaddr; 211 212 extern void ipfrag_init(void); 213 214 extern void ip_static_sysctl_init(void); 215 216 #ifdef CONFIG_INET 217 #include <net/dst.h> 218 219 /* The function in 2.2 was invalid, producing wrong result for 220 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 221 static inline 222 int ip_decrease_ttl(struct iphdr *iph) 223 { 224 u32 check = (__force u32)iph->check; 225 check += (__force u32)htons(0x0100); 226 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 227 return --iph->ttl; 228 } 229 230 static inline 231 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 232 { 233 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 234 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 235 !(dst_metric_locked(dst, RTAX_MTU)))); 236 } 237 238 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 239 240 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 241 { 242 if (iph->frag_off & htons(IP_DF)) { 243 /* This is only to work around buggy Windows95/2000 244 * VJ compression implementations. If the ID field 245 * does not change, they drop every other packet in 246 * a TCP stream using header compression. 247 */ 248 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 249 htons(inet_sk(sk)->inet_id++) : 0; 250 } else 251 __ip_select_ident(iph, dst, 0); 252 } 253 254 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 255 { 256 if (iph->frag_off & htons(IP_DF)) { 257 if (sk && inet_sk(sk)->inet_daddr) { 258 iph->id = htons(inet_sk(sk)->inet_id); 259 inet_sk(sk)->inet_id += 1 + more; 260 } else 261 iph->id = 0; 262 } else 263 __ip_select_ident(iph, dst, more); 264 } 265 266 /* 267 * Map a multicast IP onto multicast MAC for type ethernet. 268 */ 269 270 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 271 { 272 __u32 addr=ntohl(naddr); 273 buf[0]=0x01; 274 buf[1]=0x00; 275 buf[2]=0x5e; 276 buf[5]=addr&0xFF; 277 addr>>=8; 278 buf[4]=addr&0xFF; 279 addr>>=8; 280 buf[3]=addr&0x7F; 281 } 282 283 /* 284 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 285 * Leave P_Key as 0 to be filled in by driver. 286 */ 287 288 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 289 { 290 __u32 addr; 291 unsigned char scope = broadcast[5] & 0xF; 292 293 buf[0] = 0; /* Reserved */ 294 buf[1] = 0xff; /* Multicast QPN */ 295 buf[2] = 0xff; 296 buf[3] = 0xff; 297 addr = ntohl(naddr); 298 buf[4] = 0xff; 299 buf[5] = 0x10 | scope; /* scope from broadcast address */ 300 buf[6] = 0x40; /* IPv4 signature */ 301 buf[7] = 0x1b; 302 buf[8] = broadcast[8]; /* P_Key */ 303 buf[9] = broadcast[9]; 304 buf[10] = 0; 305 buf[11] = 0; 306 buf[12] = 0; 307 buf[13] = 0; 308 buf[14] = 0; 309 buf[15] = 0; 310 buf[19] = addr & 0xff; 311 addr >>= 8; 312 buf[18] = addr & 0xff; 313 addr >>= 8; 314 buf[17] = addr & 0xff; 315 addr >>= 8; 316 buf[16] = addr & 0x0f; 317 } 318 319 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 320 #include <linux/ipv6.h> 321 #endif 322 323 static __inline__ void inet_reset_saddr(struct sock *sk) 324 { 325 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 326 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 327 if (sk->sk_family == PF_INET6) { 328 struct ipv6_pinfo *np = inet6_sk(sk); 329 330 memset(&np->saddr, 0, sizeof(np->saddr)); 331 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 332 } 333 #endif 334 } 335 336 #endif 337 338 static inline int sk_mc_loop(struct sock *sk) 339 { 340 if (!sk) 341 return 1; 342 switch (sk->sk_family) { 343 case AF_INET: 344 return inet_sk(sk)->mc_loop; 345 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 346 case AF_INET6: 347 return inet6_sk(sk)->mc_loop; 348 #endif 349 } 350 WARN_ON(1); 351 return 1; 352 } 353 354 extern int ip_call_ra_chain(struct sk_buff *skb); 355 356 /* 357 * Functions provided by ip_fragment.c 358 */ 359 360 enum ip_defrag_users { 361 IP_DEFRAG_LOCAL_DELIVER, 362 IP_DEFRAG_CALL_RA_CHAIN, 363 IP_DEFRAG_CONNTRACK_IN, 364 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 365 IP_DEFRAG_CONNTRACK_OUT, 366 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 367 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 368 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 369 IP_DEFRAG_VS_IN, 370 IP_DEFRAG_VS_OUT, 371 IP_DEFRAG_VS_FWD 372 }; 373 374 int ip_defrag(struct sk_buff *skb, u32 user); 375 int ip_frag_mem(struct net *net); 376 int ip_frag_nqueues(struct net *net); 377 378 /* 379 * Functions provided by ip_forward.c 380 */ 381 382 extern int ip_forward(struct sk_buff *skb); 383 384 /* 385 * Functions provided by ip_options.c 386 */ 387 388 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 389 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 390 extern void ip_options_fragment(struct sk_buff *skb); 391 extern int ip_options_compile(struct net *net, 392 struct ip_options *opt, struct sk_buff *skb); 393 extern int ip_options_get(struct net *net, struct ip_options **optp, 394 unsigned char *data, int optlen); 395 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 396 unsigned char __user *data, int optlen); 397 extern void ip_options_undo(struct ip_options * opt); 398 extern void ip_forward_options(struct sk_buff *skb); 399 extern int ip_options_rcv_srr(struct sk_buff *skb); 400 401 /* 402 * Functions provided by ip_sockglue.c 403 */ 404 405 extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 406 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 407 extern int ip_cmsg_send(struct net *net, 408 struct msghdr *msg, struct ipcm_cookie *ipc); 409 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 410 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 411 extern int compat_ip_setsockopt(struct sock *sk, int level, 412 int optname, char __user *optval, unsigned int optlen); 413 extern int compat_ip_getsockopt(struct sock *sk, int level, 414 int optname, char __user *optval, int __user *optlen); 415 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 416 417 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 418 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 419 __be16 port, u32 info, u8 *payload); 420 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 421 u32 info); 422 423 /* sysctl helpers - any sysctl which holds a value that ends up being 424 * fed into the routing cache should use these handlers. 425 */ 426 int ipv4_doint_and_flush(ctl_table *ctl, int write, 427 void __user *buffer, 428 size_t *lenp, loff_t *ppos); 429 int ipv4_doint_and_flush_strategy(ctl_table *table, 430 void __user *oldval, size_t __user *oldlenp, 431 void __user *newval, size_t newlen); 432 #ifdef CONFIG_PROC_FS 433 extern int ip_misc_proc_init(void); 434 #endif 435 436 #endif /* _IP_H */ 437