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); 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 __percpu *mib[], int offt); 178 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize); 179 extern void snmp_mib_free(void __percpu *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 unsigned long *sysctl_local_reserved_ports; 188 static inline int inet_is_reserved_local_port(int port) 189 { 190 return test_bit(port, sysctl_local_reserved_ports); 191 } 192 193 extern int sysctl_ip_default_ttl; 194 extern int sysctl_ip_nonlocal_bind; 195 196 extern struct ctl_path net_core_path[]; 197 extern struct ctl_path net_ipv4_ctl_path[]; 198 199 /* From inetpeer.c */ 200 extern int inet_peer_threshold; 201 extern int inet_peer_minttl; 202 extern int inet_peer_maxttl; 203 extern int inet_peer_gc_mintime; 204 extern int inet_peer_gc_maxtime; 205 206 /* From ip_output.c */ 207 extern int sysctl_ip_dynaddr; 208 209 extern void ipfrag_init(void); 210 211 extern void ip_static_sysctl_init(void); 212 213 #ifdef CONFIG_INET 214 #include <net/dst.h> 215 216 /* The function in 2.2 was invalid, producing wrong result for 217 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 218 static inline 219 int ip_decrease_ttl(struct iphdr *iph) 220 { 221 u32 check = (__force u32)iph->check; 222 check += (__force u32)htons(0x0100); 223 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 224 return --iph->ttl; 225 } 226 227 static inline 228 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 229 { 230 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 231 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 232 !(dst_metric_locked(dst, RTAX_MTU)))); 233 } 234 235 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 236 237 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 238 { 239 if (iph->frag_off & htons(IP_DF)) { 240 /* This is only to work around buggy Windows95/2000 241 * VJ compression implementations. If the ID field 242 * does not change, they drop every other packet in 243 * a TCP stream using header compression. 244 */ 245 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 246 htons(inet_sk(sk)->inet_id++) : 0; 247 } else 248 __ip_select_ident(iph, dst, 0); 249 } 250 251 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 252 { 253 if (iph->frag_off & htons(IP_DF)) { 254 if (sk && inet_sk(sk)->inet_daddr) { 255 iph->id = htons(inet_sk(sk)->inet_id); 256 inet_sk(sk)->inet_id += 1 + more; 257 } else 258 iph->id = 0; 259 } else 260 __ip_select_ident(iph, dst, more); 261 } 262 263 /* 264 * Map a multicast IP onto multicast MAC for type ethernet. 265 */ 266 267 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 268 { 269 __u32 addr=ntohl(naddr); 270 buf[0]=0x01; 271 buf[1]=0x00; 272 buf[2]=0x5e; 273 buf[5]=addr&0xFF; 274 addr>>=8; 275 buf[4]=addr&0xFF; 276 addr>>=8; 277 buf[3]=addr&0x7F; 278 } 279 280 /* 281 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 282 * Leave P_Key as 0 to be filled in by driver. 283 */ 284 285 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 286 { 287 __u32 addr; 288 unsigned char scope = broadcast[5] & 0xF; 289 290 buf[0] = 0; /* Reserved */ 291 buf[1] = 0xff; /* Multicast QPN */ 292 buf[2] = 0xff; 293 buf[3] = 0xff; 294 addr = ntohl(naddr); 295 buf[4] = 0xff; 296 buf[5] = 0x10 | scope; /* scope from broadcast address */ 297 buf[6] = 0x40; /* IPv4 signature */ 298 buf[7] = 0x1b; 299 buf[8] = broadcast[8]; /* P_Key */ 300 buf[9] = broadcast[9]; 301 buf[10] = 0; 302 buf[11] = 0; 303 buf[12] = 0; 304 buf[13] = 0; 305 buf[14] = 0; 306 buf[15] = 0; 307 buf[19] = addr & 0xff; 308 addr >>= 8; 309 buf[18] = addr & 0xff; 310 addr >>= 8; 311 buf[17] = addr & 0xff; 312 addr >>= 8; 313 buf[16] = addr & 0x0f; 314 } 315 316 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 317 #include <linux/ipv6.h> 318 #endif 319 320 static __inline__ void inet_reset_saddr(struct sock *sk) 321 { 322 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 323 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 324 if (sk->sk_family == PF_INET6) { 325 struct ipv6_pinfo *np = inet6_sk(sk); 326 327 memset(&np->saddr, 0, sizeof(np->saddr)); 328 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 329 } 330 #endif 331 } 332 333 #endif 334 335 static inline int sk_mc_loop(struct sock *sk) 336 { 337 if (!sk) 338 return 1; 339 switch (sk->sk_family) { 340 case AF_INET: 341 return inet_sk(sk)->mc_loop; 342 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 343 case AF_INET6: 344 return inet6_sk(sk)->mc_loop; 345 #endif 346 } 347 WARN_ON(1); 348 return 1; 349 } 350 351 extern int ip_call_ra_chain(struct sk_buff *skb); 352 353 /* 354 * Functions provided by ip_fragment.c 355 */ 356 357 enum ip_defrag_users { 358 IP_DEFRAG_LOCAL_DELIVER, 359 IP_DEFRAG_CALL_RA_CHAIN, 360 IP_DEFRAG_CONNTRACK_IN, 361 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 362 IP_DEFRAG_CONNTRACK_OUT, 363 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 364 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 365 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 366 IP_DEFRAG_VS_IN, 367 IP_DEFRAG_VS_OUT, 368 IP_DEFRAG_VS_FWD 369 }; 370 371 int ip_defrag(struct sk_buff *skb, u32 user); 372 int ip_frag_mem(struct net *net); 373 int ip_frag_nqueues(struct net *net); 374 375 /* 376 * Functions provided by ip_forward.c 377 */ 378 379 extern int ip_forward(struct sk_buff *skb); 380 381 /* 382 * Functions provided by ip_options.c 383 */ 384 385 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 386 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 387 extern void ip_options_fragment(struct sk_buff *skb); 388 extern int ip_options_compile(struct net *net, 389 struct ip_options *opt, struct sk_buff *skb); 390 extern int ip_options_get(struct net *net, struct ip_options **optp, 391 unsigned char *data, int optlen); 392 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 393 unsigned char __user *data, int optlen); 394 extern void ip_options_undo(struct ip_options * opt); 395 extern void ip_forward_options(struct sk_buff *skb); 396 extern int ip_options_rcv_srr(struct sk_buff *skb); 397 398 /* 399 * Functions provided by ip_sockglue.c 400 */ 401 402 extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 403 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 404 extern int ip_cmsg_send(struct net *net, 405 struct msghdr *msg, struct ipcm_cookie *ipc); 406 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 407 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 408 extern int compat_ip_setsockopt(struct sock *sk, int level, 409 int optname, char __user *optval, unsigned int optlen); 410 extern int compat_ip_getsockopt(struct sock *sk, int level, 411 int optname, char __user *optval, int __user *optlen); 412 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 413 414 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 415 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 416 __be16 port, u32 info, u8 *payload); 417 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 418 u32 info); 419 420 /* sysctl helpers - any sysctl which holds a value that ends up being 421 * fed into the routing cache should use these handlers. 422 */ 423 int ipv4_doint_and_flush(ctl_table *ctl, int write, 424 void __user *buffer, 425 size_t *lenp, loff_t *ppos); 426 int ipv4_doint_and_flush_strategy(ctl_table *table, 427 void __user *oldval, size_t __user *oldlenp, 428 void __user *newval, size_t newlen); 429 #ifdef CONFIG_PROC_FS 430 extern int ip_misc_proc_init(void); 431 #endif 432 433 #endif /* _IP_H */ 434