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_rcu *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_rcu *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, struct flowi *fl); 108 extern void ip_init(void); 109 extern int ip_append_data(struct sock *sk, struct flowi4 *fl4, 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 flowi4 *fl4, struct page *page, 118 int offset, size_t size, int flags); 119 extern struct sk_buff *__ip_make_skb(struct sock *sk, 120 struct flowi4 *fl4, 121 struct sk_buff_head *queue, 122 struct inet_cork *cork); 123 extern int ip_send_skb(struct sk_buff *skb); 124 extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 125 extern void ip_flush_pending_frames(struct sock *sk); 126 extern struct sk_buff *ip_make_skb(struct sock *sk, 127 struct flowi4 *fl4, 128 int getfrag(void *from, char *to, int offset, int len, 129 int odd, struct sk_buff *skb), 130 void *from, int length, int transhdrlen, 131 struct ipcm_cookie *ipc, 132 struct rtable **rtp, 133 unsigned int flags); 134 135 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 136 { 137 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 138 } 139 140 /* datagram.c */ 141 extern int ip4_datagram_connect(struct sock *sk, 142 struct sockaddr *uaddr, int addr_len); 143 144 /* 145 * Map a multicast IP onto multicast MAC for type Token Ring. 146 * This conforms to RFC1469 Option 2 Multicasting i.e. 147 * using a functional address to transmit / receive 148 * multicast packets. 149 */ 150 151 static inline void ip_tr_mc_map(__be32 addr, char *buf) 152 { 153 buf[0]=0xC0; 154 buf[1]=0x00; 155 buf[2]=0x00; 156 buf[3]=0x04; 157 buf[4]=0x00; 158 buf[5]=0x00; 159 } 160 161 struct ip_reply_arg { 162 struct kvec iov[1]; 163 int flags; 164 __wsum csum; 165 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 166 /* -1 if not needed */ 167 int bound_dev_if; 168 u8 tos; 169 }; 170 171 #define IP_REPLY_ARG_NOSRCCHECK 1 172 173 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 174 { 175 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 176 } 177 178 void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr, 179 const struct ip_reply_arg *arg, unsigned int len); 180 181 struct ipv4_config { 182 int log_martians; 183 int no_pmtu_disc; 184 }; 185 186 extern struct ipv4_config ipv4_config; 187 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 188 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 189 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 190 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 191 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 192 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val) 193 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 194 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 195 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 196 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 197 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 198 199 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt); 200 #if BITS_PER_LONG==32 201 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 202 #else 203 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 204 { 205 return snmp_fold_field(mib, offt); 206 } 207 #endif 208 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 209 extern void snmp_mib_free(void __percpu *ptr[2]); 210 211 extern struct local_ports { 212 seqlock_t lock; 213 int range[2]; 214 } sysctl_local_ports; 215 extern void inet_get_local_port_range(int *low, int *high); 216 217 extern unsigned long *sysctl_local_reserved_ports; 218 static inline int inet_is_reserved_local_port(int port) 219 { 220 return test_bit(port, sysctl_local_reserved_ports); 221 } 222 223 extern int sysctl_ip_nonlocal_bind; 224 225 extern struct ctl_path net_core_path[]; 226 extern struct ctl_path net_ipv4_ctl_path[]; 227 228 /* From inetpeer.c */ 229 extern int inet_peer_threshold; 230 extern int inet_peer_minttl; 231 extern int inet_peer_maxttl; 232 233 /* From ip_output.c */ 234 extern int sysctl_ip_dynaddr; 235 236 extern void ipfrag_init(void); 237 238 extern void ip_static_sysctl_init(void); 239 240 static inline bool ip_is_fragment(const struct iphdr *iph) 241 { 242 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 243 } 244 245 #ifdef CONFIG_INET 246 #include <net/dst.h> 247 248 /* The function in 2.2 was invalid, producing wrong result for 249 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 250 static inline 251 int ip_decrease_ttl(struct iphdr *iph) 252 { 253 u32 check = (__force u32)iph->check; 254 check += (__force u32)htons(0x0100); 255 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 256 return --iph->ttl; 257 } 258 259 static inline 260 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 261 { 262 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 263 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 264 !(dst_metric_locked(dst, RTAX_MTU))); 265 } 266 267 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 268 269 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 270 { 271 if (iph->frag_off & htons(IP_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 iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 284 { 285 if (iph->frag_off & htons(IP_DF)) { 286 if (sk && inet_sk(sk)->inet_daddr) { 287 iph->id = htons(inet_sk(sk)->inet_id); 288 inet_sk(sk)->inet_id += 1 + more; 289 } else 290 iph->id = 0; 291 } else 292 __ip_select_ident(iph, dst, more); 293 } 294 295 /* 296 * Map a multicast IP onto multicast MAC for type ethernet. 297 */ 298 299 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 300 { 301 __u32 addr=ntohl(naddr); 302 buf[0]=0x01; 303 buf[1]=0x00; 304 buf[2]=0x5e; 305 buf[5]=addr&0xFF; 306 addr>>=8; 307 buf[4]=addr&0xFF; 308 addr>>=8; 309 buf[3]=addr&0x7F; 310 } 311 312 /* 313 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 314 * Leave P_Key as 0 to be filled in by driver. 315 */ 316 317 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 318 { 319 __u32 addr; 320 unsigned char scope = broadcast[5] & 0xF; 321 322 buf[0] = 0; /* Reserved */ 323 buf[1] = 0xff; /* Multicast QPN */ 324 buf[2] = 0xff; 325 buf[3] = 0xff; 326 addr = ntohl(naddr); 327 buf[4] = 0xff; 328 buf[5] = 0x10 | scope; /* scope from broadcast address */ 329 buf[6] = 0x40; /* IPv4 signature */ 330 buf[7] = 0x1b; 331 buf[8] = broadcast[8]; /* P_Key */ 332 buf[9] = broadcast[9]; 333 buf[10] = 0; 334 buf[11] = 0; 335 buf[12] = 0; 336 buf[13] = 0; 337 buf[14] = 0; 338 buf[15] = 0; 339 buf[19] = addr & 0xff; 340 addr >>= 8; 341 buf[18] = addr & 0xff; 342 addr >>= 8; 343 buf[17] = addr & 0xff; 344 addr >>= 8; 345 buf[16] = addr & 0x0f; 346 } 347 348 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 349 { 350 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 351 memcpy(buf, broadcast, 4); 352 else 353 memcpy(buf, &naddr, sizeof(naddr)); 354 } 355 356 #if IS_ENABLED(CONFIG_IPV6) 357 #include <linux/ipv6.h> 358 #endif 359 360 static __inline__ void inet_reset_saddr(struct sock *sk) 361 { 362 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 363 #if IS_ENABLED(CONFIG_IPV6) 364 if (sk->sk_family == PF_INET6) { 365 struct ipv6_pinfo *np = inet6_sk(sk); 366 367 memset(&np->saddr, 0, sizeof(np->saddr)); 368 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 369 } 370 #endif 371 } 372 373 #endif 374 375 static inline int sk_mc_loop(struct sock *sk) 376 { 377 if (!sk) 378 return 1; 379 switch (sk->sk_family) { 380 case AF_INET: 381 return inet_sk(sk)->mc_loop; 382 #if IS_ENABLED(CONFIG_IPV6) 383 case AF_INET6: 384 return inet6_sk(sk)->mc_loop; 385 #endif 386 } 387 WARN_ON(1); 388 return 1; 389 } 390 391 extern bool ip_call_ra_chain(struct sk_buff *skb); 392 393 /* 394 * Functions provided by ip_fragment.c 395 */ 396 397 enum ip_defrag_users { 398 IP_DEFRAG_LOCAL_DELIVER, 399 IP_DEFRAG_CALL_RA_CHAIN, 400 IP_DEFRAG_CONNTRACK_IN, 401 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 402 IP_DEFRAG_CONNTRACK_OUT, 403 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 404 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 405 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 406 IP_DEFRAG_VS_IN, 407 IP_DEFRAG_VS_OUT, 408 IP_DEFRAG_VS_FWD, 409 IP_DEFRAG_AF_PACKET, 410 IP_DEFRAG_MACVLAN, 411 }; 412 413 int ip_defrag(struct sk_buff *skb, u32 user); 414 #ifdef CONFIG_INET 415 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user); 416 #else 417 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) 418 { 419 return skb; 420 } 421 #endif 422 int ip_frag_mem(struct net *net); 423 int ip_frag_nqueues(struct net *net); 424 425 /* 426 * Functions provided by ip_forward.c 427 */ 428 429 extern int ip_forward(struct sk_buff *skb); 430 431 /* 432 * Functions provided by ip_options.c 433 */ 434 435 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 436 __be32 daddr, struct rtable *rt, int is_frag); 437 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 438 extern void ip_options_fragment(struct sk_buff *skb); 439 extern int ip_options_compile(struct net *net, 440 struct ip_options *opt, struct sk_buff *skb); 441 extern int ip_options_get(struct net *net, struct ip_options_rcu **optp, 442 unsigned char *data, int optlen); 443 extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 444 unsigned char __user *data, int optlen); 445 extern void ip_options_undo(struct ip_options * opt); 446 extern void ip_forward_options(struct sk_buff *skb); 447 extern int ip_options_rcv_srr(struct sk_buff *skb); 448 449 /* 450 * Functions provided by ip_sockglue.c 451 */ 452 453 extern void ipv4_pktinfo_prepare(struct sk_buff *skb); 454 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 455 extern int ip_cmsg_send(struct net *net, 456 struct msghdr *msg, struct ipcm_cookie *ipc); 457 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 458 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 459 extern int compat_ip_setsockopt(struct sock *sk, int level, 460 int optname, char __user *optval, unsigned int optlen); 461 extern int compat_ip_getsockopt(struct sock *sk, int level, 462 int optname, char __user *optval, int __user *optlen); 463 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 464 465 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 466 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 467 __be16 port, u32 info, u8 *payload); 468 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 469 u32 info); 470 471 #ifdef CONFIG_PROC_FS 472 extern int ip_misc_proc_init(void); 473 #endif 474 475 #endif /* _IP_H */ 476