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/route.h> 32 #include <net/snmp.h> 33 #include <net/flow.h> 34 35 struct sock; 36 37 struct inet_skb_parm { 38 struct ip_options opt; /* Compiled IP options */ 39 unsigned char flags; 40 41 #define IPSKB_FORWARDED 1 42 #define IPSKB_XFRM_TUNNEL_SIZE 2 43 #define IPSKB_XFRM_TRANSFORMED 4 44 #define IPSKB_FRAG_COMPLETE 8 45 #define IPSKB_REROUTED 16 46 47 u16 frag_max_size; 48 }; 49 50 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 51 { 52 return ip_hdr(skb)->ihl * 4; 53 } 54 55 struct ipcm_cookie { 56 __be32 addr; 57 int oif; 58 struct ip_options_rcu *opt; 59 __u8 tx_flags; 60 __u8 ttl; 61 __s16 tos; 62 char priority; 63 }; 64 65 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 66 67 struct ip_ra_chain { 68 struct ip_ra_chain __rcu *next; 69 struct sock *sk; 70 union { 71 void (*destructor)(struct sock *); 72 struct sock *saved_sk; 73 }; 74 struct rcu_head rcu; 75 }; 76 77 extern struct ip_ra_chain __rcu *ip_ra_chain; 78 79 /* IP flags. */ 80 #define IP_CE 0x8000 /* Flag: "Congestion" */ 81 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 82 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 83 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 84 85 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 86 87 struct msghdr; 88 struct net_device; 89 struct packet_type; 90 struct rtable; 91 struct sockaddr; 92 93 int igmp_mc_proc_init(void); 94 95 /* 96 * Functions provided by ip.c 97 */ 98 99 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 100 __be32 saddr, __be32 daddr, 101 struct ip_options_rcu *opt); 102 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 103 struct net_device *orig_dev); 104 int ip_local_deliver(struct sk_buff *skb); 105 int ip_mr_input(struct sk_buff *skb); 106 int ip_output(struct sk_buff *skb); 107 int ip_mc_output(struct sk_buff *skb); 108 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 109 int ip_do_nat(struct sk_buff *skb); 110 void ip_send_check(struct iphdr *ip); 111 int __ip_local_out(struct sk_buff *skb); 112 int ip_local_out(struct sk_buff *skb); 113 int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl); 114 void ip_init(void); 115 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 116 int getfrag(void *from, char *to, int offset, int len, 117 int odd, struct sk_buff *skb), 118 void *from, int len, int protolen, 119 struct ipcm_cookie *ipc, 120 struct rtable **rt, 121 unsigned int flags); 122 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 123 struct sk_buff *skb); 124 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 125 int offset, size_t size, int flags); 126 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 127 struct sk_buff_head *queue, 128 struct inet_cork *cork); 129 int ip_send_skb(struct net *net, struct sk_buff *skb); 130 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 131 void ip_flush_pending_frames(struct sock *sk); 132 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 133 int getfrag(void *from, char *to, int offset, 134 int len, int odd, struct sk_buff *skb), 135 void *from, int length, int transhdrlen, 136 struct ipcm_cookie *ipc, struct rtable **rtp, 137 unsigned int flags); 138 139 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 140 { 141 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 142 } 143 144 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet) 145 { 146 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos); 147 } 148 149 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk) 150 { 151 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk); 152 } 153 154 /* datagram.c */ 155 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 156 157 void ip4_datagram_release_cb(struct sock *sk); 158 159 struct ip_reply_arg { 160 struct kvec iov[1]; 161 int flags; 162 __wsum csum; 163 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 164 /* -1 if not needed */ 165 int bound_dev_if; 166 u8 tos; 167 }; 168 169 #define IP_REPLY_ARG_NOSRCCHECK 1 170 171 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 172 { 173 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 174 } 175 176 void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, 177 __be32 saddr, const struct ip_reply_arg *arg, 178 unsigned int len); 179 180 struct ipv4_config { 181 int log_martians; 182 int no_pmtu_disc; 183 }; 184 185 extern struct ipv4_config ipv4_config; 186 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 187 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 188 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 189 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 190 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 191 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val) 192 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 193 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 194 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 195 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 196 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 197 198 unsigned long snmp_fold_field(void __percpu *mib[], int offt); 199 #if BITS_PER_LONG==32 200 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 201 #else 202 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 203 { 204 return snmp_fold_field(mib, offt); 205 } 206 #endif 207 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 208 209 static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ]) 210 { 211 int i; 212 213 BUG_ON(ptr == NULL); 214 for (i = 0; i < SNMP_ARRAY_SZ; i++) { 215 free_percpu(ptr[i]); 216 ptr[i] = NULL; 217 } 218 } 219 220 void inet_get_local_port_range(struct net *net, int *low, int *high); 221 222 extern unsigned long *sysctl_local_reserved_ports; 223 static inline int inet_is_reserved_local_port(int port) 224 { 225 return test_bit(port, sysctl_local_reserved_ports); 226 } 227 228 extern int sysctl_ip_nonlocal_bind; 229 230 /* From inetpeer.c */ 231 extern int inet_peer_threshold; 232 extern int inet_peer_minttl; 233 extern int inet_peer_maxttl; 234 235 /* From ip_input.c */ 236 extern int sysctl_ip_early_demux; 237 238 /* From ip_output.c */ 239 extern int sysctl_ip_dynaddr; 240 241 void ipfrag_init(void); 242 243 void ip_static_sysctl_init(void); 244 245 static inline bool ip_is_fragment(const struct iphdr *iph) 246 { 247 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 248 } 249 250 #ifdef CONFIG_INET 251 #include <net/dst.h> 252 253 /* The function in 2.2 was invalid, producing wrong result for 254 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 255 static inline 256 int ip_decrease_ttl(struct iphdr *iph) 257 { 258 u32 check = (__force u32)iph->check; 259 check += (__force u32)htons(0x0100); 260 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 261 return --iph->ttl; 262 } 263 264 static inline 265 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 266 { 267 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 268 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 269 !(dst_metric_locked(dst, RTAX_MTU))); 270 } 271 272 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 273 274 static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk) 275 { 276 struct iphdr *iph = ip_hdr(skb); 277 278 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 279 /* This is only to work around buggy Windows95/2000 280 * VJ compression implementations. If the ID field 281 * does not change, they drop every other packet in 282 * a TCP stream using header compression. 283 */ 284 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 285 htons(inet_sk(sk)->inet_id++) : 0; 286 } else 287 __ip_select_ident(iph, dst, 0); 288 } 289 290 static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more) 291 { 292 struct iphdr *iph = ip_hdr(skb); 293 294 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 295 if (sk && inet_sk(sk)->inet_daddr) { 296 iph->id = htons(inet_sk(sk)->inet_id); 297 inet_sk(sk)->inet_id += 1 + more; 298 } else 299 iph->id = 0; 300 } else 301 __ip_select_ident(iph, dst, more); 302 } 303 304 /* 305 * Map a multicast IP onto multicast MAC for type ethernet. 306 */ 307 308 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 309 { 310 __u32 addr=ntohl(naddr); 311 buf[0]=0x01; 312 buf[1]=0x00; 313 buf[2]=0x5e; 314 buf[5]=addr&0xFF; 315 addr>>=8; 316 buf[4]=addr&0xFF; 317 addr>>=8; 318 buf[3]=addr&0x7F; 319 } 320 321 /* 322 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 323 * Leave P_Key as 0 to be filled in by driver. 324 */ 325 326 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 327 { 328 __u32 addr; 329 unsigned char scope = broadcast[5] & 0xF; 330 331 buf[0] = 0; /* Reserved */ 332 buf[1] = 0xff; /* Multicast QPN */ 333 buf[2] = 0xff; 334 buf[3] = 0xff; 335 addr = ntohl(naddr); 336 buf[4] = 0xff; 337 buf[5] = 0x10 | scope; /* scope from broadcast address */ 338 buf[6] = 0x40; /* IPv4 signature */ 339 buf[7] = 0x1b; 340 buf[8] = broadcast[8]; /* P_Key */ 341 buf[9] = broadcast[9]; 342 buf[10] = 0; 343 buf[11] = 0; 344 buf[12] = 0; 345 buf[13] = 0; 346 buf[14] = 0; 347 buf[15] = 0; 348 buf[19] = addr & 0xff; 349 addr >>= 8; 350 buf[18] = addr & 0xff; 351 addr >>= 8; 352 buf[17] = addr & 0xff; 353 addr >>= 8; 354 buf[16] = addr & 0x0f; 355 } 356 357 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 358 { 359 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 360 memcpy(buf, broadcast, 4); 361 else 362 memcpy(buf, &naddr, sizeof(naddr)); 363 } 364 365 #if IS_ENABLED(CONFIG_IPV6) 366 #include <linux/ipv6.h> 367 #endif 368 369 static __inline__ void inet_reset_saddr(struct sock *sk) 370 { 371 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 372 #if IS_ENABLED(CONFIG_IPV6) 373 if (sk->sk_family == PF_INET6) { 374 struct ipv6_pinfo *np = inet6_sk(sk); 375 376 memset(&np->saddr, 0, sizeof(np->saddr)); 377 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 378 } 379 #endif 380 } 381 382 #endif 383 384 static inline int sk_mc_loop(struct sock *sk) 385 { 386 if (!sk) 387 return 1; 388 switch (sk->sk_family) { 389 case AF_INET: 390 return inet_sk(sk)->mc_loop; 391 #if IS_ENABLED(CONFIG_IPV6) 392 case AF_INET6: 393 return inet6_sk(sk)->mc_loop; 394 #endif 395 } 396 WARN_ON(1); 397 return 1; 398 } 399 400 bool ip_call_ra_chain(struct sk_buff *skb); 401 402 /* 403 * Functions provided by ip_fragment.c 404 */ 405 406 enum ip_defrag_users { 407 IP_DEFRAG_LOCAL_DELIVER, 408 IP_DEFRAG_CALL_RA_CHAIN, 409 IP_DEFRAG_CONNTRACK_IN, 410 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 411 IP_DEFRAG_CONNTRACK_OUT, 412 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 413 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 414 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 415 IP_DEFRAG_VS_IN, 416 IP_DEFRAG_VS_OUT, 417 IP_DEFRAG_VS_FWD, 418 IP_DEFRAG_AF_PACKET, 419 IP_DEFRAG_MACVLAN, 420 }; 421 422 int ip_defrag(struct sk_buff *skb, u32 user); 423 #ifdef CONFIG_INET 424 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user); 425 #else 426 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) 427 { 428 return skb; 429 } 430 #endif 431 int ip_frag_mem(struct net *net); 432 int ip_frag_nqueues(struct net *net); 433 434 /* 435 * Functions provided by ip_forward.c 436 */ 437 438 int ip_forward(struct sk_buff *skb); 439 440 /* 441 * Functions provided by ip_options.c 442 */ 443 444 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 445 __be32 daddr, struct rtable *rt, int is_frag); 446 int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 447 void ip_options_fragment(struct sk_buff *skb); 448 int ip_options_compile(struct net *net, struct ip_options *opt, 449 struct sk_buff *skb); 450 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 451 unsigned char *data, int optlen); 452 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 453 unsigned char __user *data, int optlen); 454 void ip_options_undo(struct ip_options *opt); 455 void ip_forward_options(struct sk_buff *skb); 456 int ip_options_rcv_srr(struct sk_buff *skb); 457 458 /* 459 * Functions provided by ip_sockglue.c 460 */ 461 462 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); 463 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 464 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc); 465 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 466 unsigned int optlen); 467 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 468 int __user *optlen); 469 int compat_ip_setsockopt(struct sock *sk, int level, int optname, 470 char __user *optval, unsigned int optlen); 471 int compat_ip_getsockopt(struct sock *sk, int level, int optname, 472 char __user *optval, int __user *optlen); 473 int ip_ra_control(struct sock *sk, unsigned char on, 474 void (*destructor)(struct sock *)); 475 476 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 477 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 478 u32 info, u8 *payload); 479 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 480 u32 info); 481 482 #ifdef CONFIG_PROC_FS 483 int ip_misc_proc_init(void); 484 #endif 485 486 #endif /* _IP_H */ 487