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 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 void (*destructor)(struct sock *); 65 }; 66 67 extern struct ip_ra_chain *ip_ra_chain; 68 extern rwlock_t ip_ra_lock; 69 70 /* IP flags. */ 71 #define IP_CE 0x8000 /* Flag: "Congestion" */ 72 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 73 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 74 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 75 76 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 77 78 struct msghdr; 79 struct net_device; 80 struct packet_type; 81 struct rtable; 82 struct sockaddr; 83 84 extern int igmp_mc_proc_init(void); 85 86 /* 87 * Functions provided by ip.c 88 */ 89 90 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 91 __be32 saddr, __be32 daddr, 92 struct ip_options *opt); 93 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 94 struct packet_type *pt, struct net_device *orig_dev); 95 extern int ip_local_deliver(struct sk_buff *skb); 96 extern int ip_mr_input(struct sk_buff *skb); 97 extern int ip_output(struct sk_buff *skb); 98 extern int ip_mc_output(struct sk_buff *skb); 99 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 100 extern int ip_do_nat(struct sk_buff *skb); 101 extern void ip_send_check(struct iphdr *ip); 102 extern int __ip_local_out(struct sk_buff *skb); 103 extern int ip_local_out(struct sk_buff *skb); 104 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok); 105 extern void ip_init(void); 106 extern int ip_append_data(struct sock *sk, 107 int getfrag(void *from, char *to, int offset, int len, 108 int odd, struct sk_buff *skb), 109 void *from, int len, int protolen, 110 struct ipcm_cookie *ipc, 111 struct rtable **rt, 112 unsigned int flags); 113 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 114 extern ssize_t ip_append_page(struct sock *sk, struct page *page, 115 int offset, size_t size, int flags); 116 extern int ip_push_pending_frames(struct sock *sk); 117 extern void ip_flush_pending_frames(struct sock *sk); 118 119 /* datagram.c */ 120 extern int ip4_datagram_connect(struct sock *sk, 121 struct sockaddr *uaddr, int addr_len); 122 123 /* 124 * Map a multicast IP onto multicast MAC for type Token Ring. 125 * This conforms to RFC1469 Option 2 Multicasting i.e. 126 * using a functional address to transmit / receive 127 * multicast packets. 128 */ 129 130 static inline void ip_tr_mc_map(__be32 addr, char *buf) 131 { 132 buf[0]=0xC0; 133 buf[1]=0x00; 134 buf[2]=0x00; 135 buf[3]=0x04; 136 buf[4]=0x00; 137 buf[5]=0x00; 138 } 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 }; 148 149 #define IP_REPLY_ARG_NOSRCCHECK 1 150 151 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 152 { 153 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 154 } 155 156 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 157 unsigned int len); 158 159 struct ipv4_config { 160 int log_martians; 161 int no_pmtu_disc; 162 }; 163 164 extern struct ipv4_config ipv4_config; 165 #define IP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.ip_statistics, field) 166 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.ip_statistics, field) 167 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.ip_statistics, field, val) 168 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS_BH((net)->mib.ip_statistics, field, val) 169 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS((net)->mib.ip_statistics, field, val) 170 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS_BH((net)->mib.ip_statistics, field, val) 171 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 172 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 173 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 174 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 175 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 176 177 extern unsigned long snmp_fold_field(void *mib[], int offt); 178 extern int snmp_mib_init(void *ptr[2], size_t mibsize); 179 extern void snmp_mib_free(void *ptr[2]); 180 181 extern struct local_ports { 182 seqlock_t lock; 183 int range[2]; 184 } sysctl_local_ports; 185 extern void inet_get_local_port_range(int *low, int *high); 186 187 extern int sysctl_ip_default_ttl; 188 extern int sysctl_ip_nonlocal_bind; 189 190 extern struct ctl_path net_core_path[]; 191 extern struct ctl_path net_ipv4_ctl_path[]; 192 193 /* From inetpeer.c */ 194 extern int inet_peer_threshold; 195 extern int inet_peer_minttl; 196 extern int inet_peer_maxttl; 197 extern int inet_peer_gc_mintime; 198 extern int inet_peer_gc_maxtime; 199 200 /* From ip_output.c */ 201 extern int sysctl_ip_dynaddr; 202 203 extern void ipfrag_init(void); 204 205 extern void ip_static_sysctl_init(void); 206 207 #ifdef CONFIG_INET 208 #include <net/dst.h> 209 210 /* The function in 2.2 was invalid, producing wrong result for 211 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 212 static inline 213 int ip_decrease_ttl(struct iphdr *iph) 214 { 215 u32 check = (__force u32)iph->check; 216 check += (__force u32)htons(0x0100); 217 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 218 return --iph->ttl; 219 } 220 221 static inline 222 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 223 { 224 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 225 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 226 !(dst_metric_locked(dst, RTAX_MTU)))); 227 } 228 229 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 230 231 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 232 { 233 if (iph->frag_off & htons(IP_DF)) { 234 /* This is only to work around buggy Windows95/2000 235 * VJ compression implementations. If the ID field 236 * does not change, they drop every other packet in 237 * a TCP stream using header compression. 238 */ 239 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 240 htons(inet_sk(sk)->inet_id++) : 0; 241 } else 242 __ip_select_ident(iph, dst, 0); 243 } 244 245 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 246 { 247 if (iph->frag_off & htons(IP_DF)) { 248 if (sk && inet_sk(sk)->inet_daddr) { 249 iph->id = htons(inet_sk(sk)->inet_id); 250 inet_sk(sk)->inet_id += 1 + more; 251 } else 252 iph->id = 0; 253 } else 254 __ip_select_ident(iph, dst, more); 255 } 256 257 /* 258 * Map a multicast IP onto multicast MAC for type ethernet. 259 */ 260 261 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 262 { 263 __u32 addr=ntohl(naddr); 264 buf[0]=0x01; 265 buf[1]=0x00; 266 buf[2]=0x5e; 267 buf[5]=addr&0xFF; 268 addr>>=8; 269 buf[4]=addr&0xFF; 270 addr>>=8; 271 buf[3]=addr&0x7F; 272 } 273 274 /* 275 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 276 * Leave P_Key as 0 to be filled in by driver. 277 */ 278 279 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 280 { 281 __u32 addr; 282 unsigned char scope = broadcast[5] & 0xF; 283 284 buf[0] = 0; /* Reserved */ 285 buf[1] = 0xff; /* Multicast QPN */ 286 buf[2] = 0xff; 287 buf[3] = 0xff; 288 addr = ntohl(naddr); 289 buf[4] = 0xff; 290 buf[5] = 0x10 | scope; /* scope from broadcast address */ 291 buf[6] = 0x40; /* IPv4 signature */ 292 buf[7] = 0x1b; 293 buf[8] = broadcast[8]; /* P_Key */ 294 buf[9] = broadcast[9]; 295 buf[10] = 0; 296 buf[11] = 0; 297 buf[12] = 0; 298 buf[13] = 0; 299 buf[14] = 0; 300 buf[15] = 0; 301 buf[19] = addr & 0xff; 302 addr >>= 8; 303 buf[18] = addr & 0xff; 304 addr >>= 8; 305 buf[17] = addr & 0xff; 306 addr >>= 8; 307 buf[16] = addr & 0x0f; 308 } 309 310 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 311 #include <linux/ipv6.h> 312 #endif 313 314 static __inline__ void inet_reset_saddr(struct sock *sk) 315 { 316 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 317 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 318 if (sk->sk_family == PF_INET6) { 319 struct ipv6_pinfo *np = inet6_sk(sk); 320 321 memset(&np->saddr, 0, sizeof(np->saddr)); 322 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 323 } 324 #endif 325 } 326 327 #endif 328 329 static inline int sk_mc_loop(struct sock *sk) 330 { 331 if (!sk) 332 return 1; 333 switch (sk->sk_family) { 334 case AF_INET: 335 return inet_sk(sk)->mc_loop; 336 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 337 case AF_INET6: 338 return inet6_sk(sk)->mc_loop; 339 #endif 340 } 341 WARN_ON(1); 342 return 1; 343 } 344 345 extern int ip_call_ra_chain(struct sk_buff *skb); 346 347 /* 348 * Functions provided by ip_fragment.c 349 */ 350 351 enum ip_defrag_users { 352 IP_DEFRAG_LOCAL_DELIVER, 353 IP_DEFRAG_CALL_RA_CHAIN, 354 IP_DEFRAG_CONNTRACK_IN, 355 IP_DEFRAG_CONNTRACK_OUT, 356 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 357 IP_DEFRAG_VS_IN, 358 IP_DEFRAG_VS_OUT, 359 IP_DEFRAG_VS_FWD 360 }; 361 362 int ip_defrag(struct sk_buff *skb, u32 user); 363 int ip_frag_mem(struct net *net); 364 int ip_frag_nqueues(struct net *net); 365 366 /* 367 * Functions provided by ip_forward.c 368 */ 369 370 extern int ip_forward(struct sk_buff *skb); 371 372 /* 373 * Functions provided by ip_options.c 374 */ 375 376 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 377 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 378 extern void ip_options_fragment(struct sk_buff *skb); 379 extern int ip_options_compile(struct net *net, 380 struct ip_options *opt, struct sk_buff *skb); 381 extern int ip_options_get(struct net *net, struct ip_options **optp, 382 unsigned char *data, int optlen); 383 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 384 unsigned char __user *data, int optlen); 385 extern void ip_options_undo(struct ip_options * opt); 386 extern void ip_forward_options(struct sk_buff *skb); 387 extern int ip_options_rcv_srr(struct sk_buff *skb); 388 389 /* 390 * Functions provided by ip_sockglue.c 391 */ 392 393 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 394 extern int ip_cmsg_send(struct net *net, 395 struct msghdr *msg, struct ipcm_cookie *ipc); 396 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 397 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 398 extern int compat_ip_setsockopt(struct sock *sk, int level, 399 int optname, char __user *optval, unsigned int optlen); 400 extern int compat_ip_getsockopt(struct sock *sk, int level, 401 int optname, char __user *optval, int __user *optlen); 402 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 403 404 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 405 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 406 __be16 port, u32 info, u8 *payload); 407 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 408 u32 info); 409 410 /* sysctl helpers - any sysctl which holds a value that ends up being 411 * fed into the routing cache should use these handlers. 412 */ 413 int ipv4_doint_and_flush(ctl_table *ctl, int write, 414 void __user *buffer, 415 size_t *lenp, loff_t *ppos); 416 int ipv4_doint_and_flush_strategy(ctl_table *table, 417 void __user *oldval, size_t __user *oldlenp, 418 void __user *newval, size_t newlen); 419 #ifdef CONFIG_PROC_FS 420 extern int ip_misc_proc_init(void); 421 #endif 422 423 #endif /* _IP_H */ 424