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 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 181 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 182 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 183 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 184 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 185 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val) 186 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 187 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 188 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 189 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 190 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 191 192 unsigned long snmp_fold_field(void __percpu *mib[], int offt); 193 #if BITS_PER_LONG==32 194 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 195 #else 196 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 197 { 198 return snmp_fold_field(mib, offt); 199 } 200 #endif 201 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 202 203 static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ]) 204 { 205 int i; 206 207 BUG_ON(ptr == NULL); 208 for (i = 0; i < SNMP_ARRAY_SZ; i++) { 209 free_percpu(ptr[i]); 210 ptr[i] = NULL; 211 } 212 } 213 214 void inet_get_local_port_range(struct net *net, int *low, int *high); 215 216 extern unsigned long *sysctl_local_reserved_ports; 217 static inline int inet_is_reserved_local_port(int port) 218 { 219 return test_bit(port, sysctl_local_reserved_ports); 220 } 221 222 extern int sysctl_ip_nonlocal_bind; 223 224 /* From inetpeer.c */ 225 extern int inet_peer_threshold; 226 extern int inet_peer_minttl; 227 extern int inet_peer_maxttl; 228 229 /* From ip_input.c */ 230 extern int sysctl_ip_early_demux; 231 232 /* From ip_output.c */ 233 extern int sysctl_ip_dynaddr; 234 235 void ipfrag_init(void); 236 237 void ip_static_sysctl_init(void); 238 239 static inline bool ip_is_fragment(const struct iphdr *iph) 240 { 241 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 242 } 243 244 #ifdef CONFIG_INET 245 #include <net/dst.h> 246 247 /* The function in 2.2 was invalid, producing wrong result for 248 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 249 static inline 250 int ip_decrease_ttl(struct iphdr *iph) 251 { 252 u32 check = (__force u32)iph->check; 253 check += (__force u32)htons(0x0100); 254 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 255 return --iph->ttl; 256 } 257 258 static inline 259 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 260 { 261 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 262 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 263 !(dst_metric_locked(dst, RTAX_MTU))); 264 } 265 266 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 267 268 static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk) 269 { 270 struct iphdr *iph = ip_hdr(skb); 271 272 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 273 /* This is only to work around buggy Windows95/2000 274 * VJ compression implementations. If the ID field 275 * does not change, they drop every other packet in 276 * a TCP stream using header compression. 277 */ 278 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 279 htons(inet_sk(sk)->inet_id++) : 0; 280 } else 281 __ip_select_ident(iph, dst, 0); 282 } 283 284 static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more) 285 { 286 struct iphdr *iph = ip_hdr(skb); 287 288 if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) { 289 if (sk && inet_sk(sk)->inet_daddr) { 290 iph->id = htons(inet_sk(sk)->inet_id); 291 inet_sk(sk)->inet_id += 1 + more; 292 } else 293 iph->id = 0; 294 } else 295 __ip_select_ident(iph, dst, more); 296 } 297 298 /* 299 * Map a multicast IP onto multicast MAC for type ethernet. 300 */ 301 302 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 303 { 304 __u32 addr=ntohl(naddr); 305 buf[0]=0x01; 306 buf[1]=0x00; 307 buf[2]=0x5e; 308 buf[5]=addr&0xFF; 309 addr>>=8; 310 buf[4]=addr&0xFF; 311 addr>>=8; 312 buf[3]=addr&0x7F; 313 } 314 315 /* 316 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 317 * Leave P_Key as 0 to be filled in by driver. 318 */ 319 320 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 321 { 322 __u32 addr; 323 unsigned char scope = broadcast[5] & 0xF; 324 325 buf[0] = 0; /* Reserved */ 326 buf[1] = 0xff; /* Multicast QPN */ 327 buf[2] = 0xff; 328 buf[3] = 0xff; 329 addr = ntohl(naddr); 330 buf[4] = 0xff; 331 buf[5] = 0x10 | scope; /* scope from broadcast address */ 332 buf[6] = 0x40; /* IPv4 signature */ 333 buf[7] = 0x1b; 334 buf[8] = broadcast[8]; /* P_Key */ 335 buf[9] = broadcast[9]; 336 buf[10] = 0; 337 buf[11] = 0; 338 buf[12] = 0; 339 buf[13] = 0; 340 buf[14] = 0; 341 buf[15] = 0; 342 buf[19] = addr & 0xff; 343 addr >>= 8; 344 buf[18] = addr & 0xff; 345 addr >>= 8; 346 buf[17] = addr & 0xff; 347 addr >>= 8; 348 buf[16] = addr & 0x0f; 349 } 350 351 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 352 { 353 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 354 memcpy(buf, broadcast, 4); 355 else 356 memcpy(buf, &naddr, sizeof(naddr)); 357 } 358 359 #if IS_ENABLED(CONFIG_IPV6) 360 #include <linux/ipv6.h> 361 #endif 362 363 static __inline__ void inet_reset_saddr(struct sock *sk) 364 { 365 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 366 #if IS_ENABLED(CONFIG_IPV6) 367 if (sk->sk_family == PF_INET6) { 368 struct ipv6_pinfo *np = inet6_sk(sk); 369 370 memset(&np->saddr, 0, sizeof(np->saddr)); 371 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 372 } 373 #endif 374 } 375 376 #endif 377 378 static inline int sk_mc_loop(struct sock *sk) 379 { 380 if (!sk) 381 return 1; 382 switch (sk->sk_family) { 383 case AF_INET: 384 return inet_sk(sk)->mc_loop; 385 #if IS_ENABLED(CONFIG_IPV6) 386 case AF_INET6: 387 return inet6_sk(sk)->mc_loop; 388 #endif 389 } 390 WARN_ON(1); 391 return 1; 392 } 393 394 bool ip_call_ra_chain(struct sk_buff *skb); 395 396 /* 397 * Functions provided by ip_fragment.c 398 */ 399 400 enum ip_defrag_users { 401 IP_DEFRAG_LOCAL_DELIVER, 402 IP_DEFRAG_CALL_RA_CHAIN, 403 IP_DEFRAG_CONNTRACK_IN, 404 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 405 IP_DEFRAG_CONNTRACK_OUT, 406 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 407 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 408 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 409 IP_DEFRAG_VS_IN, 410 IP_DEFRAG_VS_OUT, 411 IP_DEFRAG_VS_FWD, 412 IP_DEFRAG_AF_PACKET, 413 IP_DEFRAG_MACVLAN, 414 }; 415 416 int ip_defrag(struct sk_buff *skb, u32 user); 417 #ifdef CONFIG_INET 418 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user); 419 #else 420 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) 421 { 422 return skb; 423 } 424 #endif 425 int ip_frag_mem(struct net *net); 426 int ip_frag_nqueues(struct net *net); 427 428 /* 429 * Functions provided by ip_forward.c 430 */ 431 432 int ip_forward(struct sk_buff *skb); 433 434 /* 435 * Functions provided by ip_options.c 436 */ 437 438 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 439 __be32 daddr, struct rtable *rt, int is_frag); 440 int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 441 void ip_options_fragment(struct sk_buff *skb); 442 int ip_options_compile(struct net *net, struct ip_options *opt, 443 struct sk_buff *skb); 444 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 445 unsigned char *data, int optlen); 446 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 447 unsigned char __user *data, int optlen); 448 void ip_options_undo(struct ip_options *opt); 449 void ip_forward_options(struct sk_buff *skb); 450 int ip_options_rcv_srr(struct sk_buff *skb); 451 452 /* 453 * Functions provided by ip_sockglue.c 454 */ 455 456 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); 457 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 458 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc); 459 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, 460 unsigned int optlen); 461 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 462 int __user *optlen); 463 int compat_ip_setsockopt(struct sock *sk, int level, int optname, 464 char __user *optval, unsigned int optlen); 465 int compat_ip_getsockopt(struct sock *sk, int level, int optname, 466 char __user *optval, int __user *optlen); 467 int ip_ra_control(struct sock *sk, unsigned char on, 468 void (*destructor)(struct sock *)); 469 470 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 471 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 472 u32 info, u8 *payload); 473 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 474 u32 info); 475 476 #ifdef CONFIG_PROC_FS 477 int ip_misc_proc_init(void); 478 #endif 479 480 #endif /* _IP_H */ 481