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 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_STATS64((net)->mib.ip_statistics, field) 169 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 170 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 171 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 172 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 173 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_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 #if BITS_PER_LONG==32 182 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 183 #else 184 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 185 { 186 return snmp_fold_field(mib, offt); 187 } 188 #endif 189 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 190 extern void snmp_mib_free(void __percpu *ptr[2]); 191 192 extern struct local_ports { 193 seqlock_t lock; 194 int range[2]; 195 } sysctl_local_ports; 196 extern void inet_get_local_port_range(int *low, int *high); 197 198 extern unsigned long *sysctl_local_reserved_ports; 199 static inline int inet_is_reserved_local_port(int port) 200 { 201 return test_bit(port, sysctl_local_reserved_ports); 202 } 203 204 extern int sysctl_ip_default_ttl; 205 extern int sysctl_ip_nonlocal_bind; 206 207 extern struct ctl_path net_core_path[]; 208 extern struct ctl_path net_ipv4_ctl_path[]; 209 210 /* From inetpeer.c */ 211 extern int inet_peer_threshold; 212 extern int inet_peer_minttl; 213 extern int inet_peer_maxttl; 214 extern int inet_peer_gc_mintime; 215 extern int inet_peer_gc_maxtime; 216 217 /* From ip_output.c */ 218 extern int sysctl_ip_dynaddr; 219 220 extern void ipfrag_init(void); 221 222 extern void ip_static_sysctl_init(void); 223 224 #ifdef CONFIG_INET 225 #include <net/dst.h> 226 227 /* The function in 2.2 was invalid, producing wrong result for 228 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 229 static inline 230 int ip_decrease_ttl(struct iphdr *iph) 231 { 232 u32 check = (__force u32)iph->check; 233 check += (__force u32)htons(0x0100); 234 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 235 return --iph->ttl; 236 } 237 238 static inline 239 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 240 { 241 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 242 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 243 !(dst_metric_locked(dst, RTAX_MTU))); 244 } 245 246 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 247 248 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 249 { 250 if (iph->frag_off & htons(IP_DF)) { 251 /* This is only to work around buggy Windows95/2000 252 * VJ compression implementations. If the ID field 253 * does not change, they drop every other packet in 254 * a TCP stream using header compression. 255 */ 256 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 257 htons(inet_sk(sk)->inet_id++) : 0; 258 } else 259 __ip_select_ident(iph, dst, 0); 260 } 261 262 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 263 { 264 if (iph->frag_off & htons(IP_DF)) { 265 if (sk && inet_sk(sk)->inet_daddr) { 266 iph->id = htons(inet_sk(sk)->inet_id); 267 inet_sk(sk)->inet_id += 1 + more; 268 } else 269 iph->id = 0; 270 } else 271 __ip_select_ident(iph, dst, more); 272 } 273 274 /* 275 * Map a multicast IP onto multicast MAC for type ethernet. 276 */ 277 278 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 279 { 280 __u32 addr=ntohl(naddr); 281 buf[0]=0x01; 282 buf[1]=0x00; 283 buf[2]=0x5e; 284 buf[5]=addr&0xFF; 285 addr>>=8; 286 buf[4]=addr&0xFF; 287 addr>>=8; 288 buf[3]=addr&0x7F; 289 } 290 291 /* 292 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 293 * Leave P_Key as 0 to be filled in by driver. 294 */ 295 296 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 297 { 298 __u32 addr; 299 unsigned char scope = broadcast[5] & 0xF; 300 301 buf[0] = 0; /* Reserved */ 302 buf[1] = 0xff; /* Multicast QPN */ 303 buf[2] = 0xff; 304 buf[3] = 0xff; 305 addr = ntohl(naddr); 306 buf[4] = 0xff; 307 buf[5] = 0x10 | scope; /* scope from broadcast address */ 308 buf[6] = 0x40; /* IPv4 signature */ 309 buf[7] = 0x1b; 310 buf[8] = broadcast[8]; /* P_Key */ 311 buf[9] = broadcast[9]; 312 buf[10] = 0; 313 buf[11] = 0; 314 buf[12] = 0; 315 buf[13] = 0; 316 buf[14] = 0; 317 buf[15] = 0; 318 buf[19] = addr & 0xff; 319 addr >>= 8; 320 buf[18] = addr & 0xff; 321 addr >>= 8; 322 buf[17] = addr & 0xff; 323 addr >>= 8; 324 buf[16] = addr & 0x0f; 325 } 326 327 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 328 #include <linux/ipv6.h> 329 #endif 330 331 static __inline__ void inet_reset_saddr(struct sock *sk) 332 { 333 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 334 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 335 if (sk->sk_family == PF_INET6) { 336 struct ipv6_pinfo *np = inet6_sk(sk); 337 338 memset(&np->saddr, 0, sizeof(np->saddr)); 339 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 340 } 341 #endif 342 } 343 344 #endif 345 346 static inline int sk_mc_loop(struct sock *sk) 347 { 348 if (!sk) 349 return 1; 350 switch (sk->sk_family) { 351 case AF_INET: 352 return inet_sk(sk)->mc_loop; 353 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 354 case AF_INET6: 355 return inet6_sk(sk)->mc_loop; 356 #endif 357 } 358 WARN_ON(1); 359 return 1; 360 } 361 362 extern int ip_call_ra_chain(struct sk_buff *skb); 363 364 /* 365 * Functions provided by ip_fragment.c 366 */ 367 368 enum ip_defrag_users { 369 IP_DEFRAG_LOCAL_DELIVER, 370 IP_DEFRAG_CALL_RA_CHAIN, 371 IP_DEFRAG_CONNTRACK_IN, 372 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 373 IP_DEFRAG_CONNTRACK_OUT, 374 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 375 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 376 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 377 IP_DEFRAG_VS_IN, 378 IP_DEFRAG_VS_OUT, 379 IP_DEFRAG_VS_FWD 380 }; 381 382 int ip_defrag(struct sk_buff *skb, u32 user); 383 int ip_frag_mem(struct net *net); 384 int ip_frag_nqueues(struct net *net); 385 386 /* 387 * Functions provided by ip_forward.c 388 */ 389 390 extern int ip_forward(struct sk_buff *skb); 391 392 /* 393 * Functions provided by ip_options.c 394 */ 395 396 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 397 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 398 extern void ip_options_fragment(struct sk_buff *skb); 399 extern int ip_options_compile(struct net *net, 400 struct ip_options *opt, struct sk_buff *skb); 401 extern int ip_options_get(struct net *net, struct ip_options **optp, 402 unsigned char *data, int optlen); 403 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 404 unsigned char __user *data, int optlen); 405 extern void ip_options_undo(struct ip_options * opt); 406 extern void ip_forward_options(struct sk_buff *skb); 407 extern int ip_options_rcv_srr(struct sk_buff *skb); 408 409 /* 410 * Functions provided by ip_sockglue.c 411 */ 412 413 extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 414 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 415 extern int ip_cmsg_send(struct net *net, 416 struct msghdr *msg, struct ipcm_cookie *ipc); 417 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 418 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 419 extern int compat_ip_setsockopt(struct sock *sk, int level, 420 int optname, char __user *optval, unsigned int optlen); 421 extern int compat_ip_getsockopt(struct sock *sk, int level, 422 int optname, char __user *optval, int __user *optlen); 423 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 424 425 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 426 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 427 __be16 port, u32 info, u8 *payload); 428 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 429 u32 info); 430 431 /* sysctl helpers - any sysctl which holds a value that ends up being 432 * fed into the routing cache should use these handlers. 433 */ 434 int ipv4_doint_and_flush(ctl_table *ctl, int write, 435 void __user *buffer, 436 size_t *lenp, loff_t *ppos); 437 int ipv4_doint_and_flush_strategy(ctl_table *table, 438 void __user *oldval, size_t __user *oldlenp, 439 void __user *newval, size_t newlen); 440 #ifdef CONFIG_PROC_FS 441 extern int ip_misc_proc_init(void); 442 #endif 443 444 #endif /* _IP_H */ 445