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 u16 frag_max_size; 47 }; 48 49 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 50 { 51 return ip_hdr(skb)->ihl * 4; 52 } 53 54 struct ipcm_cookie { 55 __be32 addr; 56 int oif; 57 struct ip_options_rcu *opt; 58 __u8 tx_flags; 59 }; 60 61 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 62 63 struct ip_ra_chain { 64 struct ip_ra_chain __rcu *next; 65 struct sock *sk; 66 union { 67 void (*destructor)(struct sock *); 68 struct sock *saved_sk; 69 }; 70 struct rcu_head rcu; 71 }; 72 73 extern struct ip_ra_chain __rcu *ip_ra_chain; 74 75 /* IP flags. */ 76 #define IP_CE 0x8000 /* Flag: "Congestion" */ 77 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 78 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 79 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 80 81 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 82 83 struct msghdr; 84 struct net_device; 85 struct packet_type; 86 struct rtable; 87 struct sockaddr; 88 89 extern int igmp_mc_proc_init(void); 90 91 /* 92 * Functions provided by ip.c 93 */ 94 95 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 96 __be32 saddr, __be32 daddr, 97 struct ip_options_rcu *opt); 98 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 99 struct packet_type *pt, struct net_device *orig_dev); 100 extern int ip_local_deliver(struct sk_buff *skb); 101 extern int ip_mr_input(struct sk_buff *skb); 102 extern int ip_output(struct sk_buff *skb); 103 extern int ip_mc_output(struct sk_buff *skb); 104 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 105 extern int ip_do_nat(struct sk_buff *skb); 106 extern void ip_send_check(struct iphdr *ip); 107 extern int __ip_local_out(struct sk_buff *skb); 108 extern int ip_local_out(struct sk_buff *skb); 109 extern int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl); 110 extern void ip_init(void); 111 extern int ip_append_data(struct sock *sk, struct flowi4 *fl4, 112 int getfrag(void *from, char *to, int offset, int len, 113 int odd, struct sk_buff *skb), 114 void *from, int len, int protolen, 115 struct ipcm_cookie *ipc, 116 struct rtable **rt, 117 unsigned int flags); 118 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 119 extern ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 120 int offset, size_t size, int flags); 121 extern struct sk_buff *__ip_make_skb(struct sock *sk, 122 struct flowi4 *fl4, 123 struct sk_buff_head *queue, 124 struct inet_cork *cork); 125 extern int ip_send_skb(struct net *net, struct sk_buff *skb); 126 extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 127 extern void ip_flush_pending_frames(struct sock *sk); 128 extern struct sk_buff *ip_make_skb(struct sock *sk, 129 struct flowi4 *fl4, 130 int getfrag(void *from, char *to, int offset, int len, 131 int odd, struct sk_buff *skb), 132 void *from, int length, int transhdrlen, 133 struct ipcm_cookie *ipc, 134 struct rtable **rtp, 135 unsigned int flags); 136 137 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 138 { 139 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 140 } 141 142 /* datagram.c */ 143 extern int ip4_datagram_connect(struct sock *sk, 144 struct sockaddr *uaddr, int addr_len); 145 146 extern void ip4_datagram_release_cb(struct sock *sk); 147 148 struct ip_reply_arg { 149 struct kvec iov[1]; 150 int flags; 151 __wsum csum; 152 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 153 /* -1 if not needed */ 154 int bound_dev_if; 155 u8 tos; 156 }; 157 158 #define IP_REPLY_ARG_NOSRCCHECK 1 159 160 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 161 { 162 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 163 } 164 165 void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, 166 __be32 saddr, const struct ip_reply_arg *arg, 167 unsigned int len); 168 169 struct ipv4_config { 170 int log_martians; 171 int no_pmtu_disc; 172 }; 173 174 extern struct ipv4_config ipv4_config; 175 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 176 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 177 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 178 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 179 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 180 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val) 181 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 182 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 183 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 184 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 185 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 186 187 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt); 188 #if BITS_PER_LONG==32 189 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 190 #else 191 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 192 { 193 return snmp_fold_field(mib, offt); 194 } 195 #endif 196 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 197 198 static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ]) 199 { 200 int i; 201 202 BUG_ON(ptr == NULL); 203 for (i = 0; i < SNMP_ARRAY_SZ; i++) { 204 free_percpu(ptr[i]); 205 ptr[i] = NULL; 206 } 207 } 208 209 extern struct local_ports { 210 seqlock_t lock; 211 int range[2]; 212 } sysctl_local_ports; 213 extern void inet_get_local_port_range(int *low, int *high); 214 215 extern unsigned long *sysctl_local_reserved_ports; 216 static inline int inet_is_reserved_local_port(int port) 217 { 218 return test_bit(port, sysctl_local_reserved_ports); 219 } 220 221 extern int sysctl_ip_nonlocal_bind; 222 223 /* From inetpeer.c */ 224 extern int inet_peer_threshold; 225 extern int inet_peer_minttl; 226 extern int inet_peer_maxttl; 227 228 /* From ip_input.c */ 229 extern int sysctl_ip_early_demux; 230 231 /* From ip_output.c */ 232 extern int sysctl_ip_dynaddr; 233 234 extern void ipfrag_init(void); 235 236 extern void ip_static_sysctl_init(void); 237 238 static inline bool ip_is_fragment(const struct iphdr *iph) 239 { 240 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 241 } 242 243 #ifdef CONFIG_INET 244 #include <net/dst.h> 245 246 /* The function in 2.2 was invalid, producing wrong result for 247 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 248 static inline 249 int ip_decrease_ttl(struct iphdr *iph) 250 { 251 u32 check = (__force u32)iph->check; 252 check += (__force u32)htons(0x0100); 253 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 254 return --iph->ttl; 255 } 256 257 static inline 258 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 259 { 260 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 261 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 262 !(dst_metric_locked(dst, RTAX_MTU))); 263 } 264 265 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 266 267 static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk) 268 { 269 struct iphdr *iph = ip_hdr(skb); 270 271 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 272 /* This is only to work around buggy Windows95/2000 273 * VJ compression implementations. If the ID field 274 * does not change, they drop every other packet in 275 * a TCP stream using header compression. 276 */ 277 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 278 htons(inet_sk(sk)->inet_id++) : 0; 279 } else 280 __ip_select_ident(iph, dst, 0); 281 } 282 283 static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more) 284 { 285 struct iphdr *iph = ip_hdr(skb); 286 287 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 288 if (sk && inet_sk(sk)->inet_daddr) { 289 iph->id = htons(inet_sk(sk)->inet_id); 290 inet_sk(sk)->inet_id += 1 + more; 291 } else 292 iph->id = 0; 293 } else 294 __ip_select_ident(iph, dst, more); 295 } 296 297 /* 298 * Map a multicast IP onto multicast MAC for type ethernet. 299 */ 300 301 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 302 { 303 __u32 addr=ntohl(naddr); 304 buf[0]=0x01; 305 buf[1]=0x00; 306 buf[2]=0x5e; 307 buf[5]=addr&0xFF; 308 addr>>=8; 309 buf[4]=addr&0xFF; 310 addr>>=8; 311 buf[3]=addr&0x7F; 312 } 313 314 /* 315 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 316 * Leave P_Key as 0 to be filled in by driver. 317 */ 318 319 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 320 { 321 __u32 addr; 322 unsigned char scope = broadcast[5] & 0xF; 323 324 buf[0] = 0; /* Reserved */ 325 buf[1] = 0xff; /* Multicast QPN */ 326 buf[2] = 0xff; 327 buf[3] = 0xff; 328 addr = ntohl(naddr); 329 buf[4] = 0xff; 330 buf[5] = 0x10 | scope; /* scope from broadcast address */ 331 buf[6] = 0x40; /* IPv4 signature */ 332 buf[7] = 0x1b; 333 buf[8] = broadcast[8]; /* P_Key */ 334 buf[9] = broadcast[9]; 335 buf[10] = 0; 336 buf[11] = 0; 337 buf[12] = 0; 338 buf[13] = 0; 339 buf[14] = 0; 340 buf[15] = 0; 341 buf[19] = addr & 0xff; 342 addr >>= 8; 343 buf[18] = addr & 0xff; 344 addr >>= 8; 345 buf[17] = addr & 0xff; 346 addr >>= 8; 347 buf[16] = addr & 0x0f; 348 } 349 350 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 351 { 352 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 353 memcpy(buf, broadcast, 4); 354 else 355 memcpy(buf, &naddr, sizeof(naddr)); 356 } 357 358 #if IS_ENABLED(CONFIG_IPV6) 359 #include <linux/ipv6.h> 360 #endif 361 362 static __inline__ void inet_reset_saddr(struct sock *sk) 363 { 364 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 365 #if IS_ENABLED(CONFIG_IPV6) 366 if (sk->sk_family == PF_INET6) { 367 struct ipv6_pinfo *np = inet6_sk(sk); 368 369 memset(&np->saddr, 0, sizeof(np->saddr)); 370 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 371 } 372 #endif 373 } 374 375 #endif 376 377 static inline int sk_mc_loop(struct sock *sk) 378 { 379 if (!sk) 380 return 1; 381 switch (sk->sk_family) { 382 case AF_INET: 383 return inet_sk(sk)->mc_loop; 384 #if IS_ENABLED(CONFIG_IPV6) 385 case AF_INET6: 386 return inet6_sk(sk)->mc_loop; 387 #endif 388 } 389 WARN_ON(1); 390 return 1; 391 } 392 393 extern bool ip_call_ra_chain(struct sk_buff *skb); 394 395 /* 396 * Functions provided by ip_fragment.c 397 */ 398 399 enum ip_defrag_users { 400 IP_DEFRAG_LOCAL_DELIVER, 401 IP_DEFRAG_CALL_RA_CHAIN, 402 IP_DEFRAG_CONNTRACK_IN, 403 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 404 IP_DEFRAG_CONNTRACK_OUT, 405 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 406 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 407 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 408 IP_DEFRAG_VS_IN, 409 IP_DEFRAG_VS_OUT, 410 IP_DEFRAG_VS_FWD, 411 IP_DEFRAG_AF_PACKET, 412 IP_DEFRAG_MACVLAN, 413 }; 414 415 int ip_defrag(struct sk_buff *skb, u32 user); 416 #ifdef CONFIG_INET 417 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user); 418 #else 419 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) 420 { 421 return skb; 422 } 423 #endif 424 int ip_frag_mem(struct net *net); 425 int ip_frag_nqueues(struct net *net); 426 427 /* 428 * Functions provided by ip_forward.c 429 */ 430 431 extern int ip_forward(struct sk_buff *skb); 432 433 /* 434 * Functions provided by ip_options.c 435 */ 436 437 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 438 __be32 daddr, struct rtable *rt, int is_frag); 439 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 440 extern void ip_options_fragment(struct sk_buff *skb); 441 extern int ip_options_compile(struct net *net, 442 struct ip_options *opt, struct sk_buff *skb); 443 extern int ip_options_get(struct net *net, struct ip_options_rcu **optp, 444 unsigned char *data, int optlen); 445 extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 446 unsigned char __user *data, int optlen); 447 extern void ip_options_undo(struct ip_options * opt); 448 extern void ip_forward_options(struct sk_buff *skb); 449 extern int ip_options_rcv_srr(struct sk_buff *skb); 450 451 /* 452 * Functions provided by ip_sockglue.c 453 */ 454 455 extern void ipv4_pktinfo_prepare(struct sk_buff *skb); 456 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 457 extern int ip_cmsg_send(struct net *net, 458 struct msghdr *msg, struct ipcm_cookie *ipc); 459 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 460 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 461 extern int compat_ip_setsockopt(struct sock *sk, int level, 462 int optname, char __user *optval, unsigned int optlen); 463 extern int compat_ip_getsockopt(struct sock *sk, int level, 464 int optname, char __user *optval, int __user *optlen); 465 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 466 467 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 468 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 469 __be16 port, u32 info, u8 *payload); 470 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 471 u32 info); 472 473 #ifdef CONFIG_PROC_FS 474 extern int ip_misc_proc_init(void); 475 #endif 476 477 #endif /* _IP_H */ 478