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 net *net, 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 struct ip_reply_arg { 145 struct kvec iov[1]; 146 int flags; 147 __wsum csum; 148 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 149 /* -1 if not needed */ 150 int bound_dev_if; 151 u8 tos; 152 }; 153 154 #define IP_REPLY_ARG_NOSRCCHECK 1 155 156 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 157 { 158 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 159 } 160 161 void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, 162 __be32 saddr, const struct ip_reply_arg *arg, 163 unsigned int len); 164 165 struct ipv4_config { 166 int log_martians; 167 int no_pmtu_disc; 168 }; 169 170 extern struct ipv4_config ipv4_config; 171 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 172 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field) 173 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 174 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val) 175 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 176 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val) 177 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 178 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 179 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 180 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 181 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 182 183 extern unsigned long snmp_fold_field(void __percpu *mib[], int offt); 184 #if BITS_PER_LONG==32 185 extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off); 186 #else 187 static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off) 188 { 189 return snmp_fold_field(mib, offt); 190 } 191 #endif 192 extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align); 193 extern void snmp_mib_free(void __percpu *ptr[2]); 194 195 extern struct local_ports { 196 seqlock_t lock; 197 int range[2]; 198 } sysctl_local_ports; 199 extern void inet_get_local_port_range(int *low, int *high); 200 201 extern unsigned long *sysctl_local_reserved_ports; 202 static inline int inet_is_reserved_local_port(int port) 203 { 204 return test_bit(port, sysctl_local_reserved_ports); 205 } 206 207 extern int sysctl_ip_nonlocal_bind; 208 209 /* From inetpeer.c */ 210 extern int inet_peer_threshold; 211 extern int inet_peer_minttl; 212 extern int inet_peer_maxttl; 213 214 /* From ip_input.c */ 215 extern int sysctl_ip_early_demux; 216 217 /* From ip_output.c */ 218 extern int sysctl_ip_dynaddr; 219 220 extern void ipfrag_init(void); 221 222 extern void ip_static_sysctl_init(void); 223 224 static inline bool ip_is_fragment(const struct iphdr *iph) 225 { 226 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 227 } 228 229 #ifdef CONFIG_INET 230 #include <net/dst.h> 231 232 /* The function in 2.2 was invalid, producing wrong result for 233 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 234 static inline 235 int ip_decrease_ttl(struct iphdr *iph) 236 { 237 u32 check = (__force u32)iph->check; 238 check += (__force u32)htons(0x0100); 239 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 240 return --iph->ttl; 241 } 242 243 static inline 244 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 245 { 246 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 247 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 248 !(dst_metric_locked(dst, RTAX_MTU))); 249 } 250 251 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 252 253 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 254 { 255 if (iph->frag_off & htons(IP_DF)) { 256 /* This is only to work around buggy Windows95/2000 257 * VJ compression implementations. If the ID field 258 * does not change, they drop every other packet in 259 * a TCP stream using header compression. 260 */ 261 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 262 htons(inet_sk(sk)->inet_id++) : 0; 263 } else 264 __ip_select_ident(iph, dst, 0); 265 } 266 267 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 268 { 269 if (iph->frag_off & htons(IP_DF)) { 270 if (sk && inet_sk(sk)->inet_daddr) { 271 iph->id = htons(inet_sk(sk)->inet_id); 272 inet_sk(sk)->inet_id += 1 + more; 273 } else 274 iph->id = 0; 275 } else 276 __ip_select_ident(iph, dst, more); 277 } 278 279 /* 280 * Map a multicast IP onto multicast MAC for type ethernet. 281 */ 282 283 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 284 { 285 __u32 addr=ntohl(naddr); 286 buf[0]=0x01; 287 buf[1]=0x00; 288 buf[2]=0x5e; 289 buf[5]=addr&0xFF; 290 addr>>=8; 291 buf[4]=addr&0xFF; 292 addr>>=8; 293 buf[3]=addr&0x7F; 294 } 295 296 /* 297 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 298 * Leave P_Key as 0 to be filled in by driver. 299 */ 300 301 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 302 { 303 __u32 addr; 304 unsigned char scope = broadcast[5] & 0xF; 305 306 buf[0] = 0; /* Reserved */ 307 buf[1] = 0xff; /* Multicast QPN */ 308 buf[2] = 0xff; 309 buf[3] = 0xff; 310 addr = ntohl(naddr); 311 buf[4] = 0xff; 312 buf[5] = 0x10 | scope; /* scope from broadcast address */ 313 buf[6] = 0x40; /* IPv4 signature */ 314 buf[7] = 0x1b; 315 buf[8] = broadcast[8]; /* P_Key */ 316 buf[9] = broadcast[9]; 317 buf[10] = 0; 318 buf[11] = 0; 319 buf[12] = 0; 320 buf[13] = 0; 321 buf[14] = 0; 322 buf[15] = 0; 323 buf[19] = addr & 0xff; 324 addr >>= 8; 325 buf[18] = addr & 0xff; 326 addr >>= 8; 327 buf[17] = addr & 0xff; 328 addr >>= 8; 329 buf[16] = addr & 0x0f; 330 } 331 332 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 333 { 334 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 335 memcpy(buf, broadcast, 4); 336 else 337 memcpy(buf, &naddr, sizeof(naddr)); 338 } 339 340 #if IS_ENABLED(CONFIG_IPV6) 341 #include <linux/ipv6.h> 342 #endif 343 344 static __inline__ void inet_reset_saddr(struct sock *sk) 345 { 346 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 347 #if IS_ENABLED(CONFIG_IPV6) 348 if (sk->sk_family == PF_INET6) { 349 struct ipv6_pinfo *np = inet6_sk(sk); 350 351 memset(&np->saddr, 0, sizeof(np->saddr)); 352 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 353 } 354 #endif 355 } 356 357 #endif 358 359 static inline int sk_mc_loop(struct sock *sk) 360 { 361 if (!sk) 362 return 1; 363 switch (sk->sk_family) { 364 case AF_INET: 365 return inet_sk(sk)->mc_loop; 366 #if IS_ENABLED(CONFIG_IPV6) 367 case AF_INET6: 368 return inet6_sk(sk)->mc_loop; 369 #endif 370 } 371 WARN_ON(1); 372 return 1; 373 } 374 375 extern bool ip_call_ra_chain(struct sk_buff *skb); 376 377 /* 378 * Functions provided by ip_fragment.c 379 */ 380 381 enum ip_defrag_users { 382 IP_DEFRAG_LOCAL_DELIVER, 383 IP_DEFRAG_CALL_RA_CHAIN, 384 IP_DEFRAG_CONNTRACK_IN, 385 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 386 IP_DEFRAG_CONNTRACK_OUT, 387 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 388 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 389 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 390 IP_DEFRAG_VS_IN, 391 IP_DEFRAG_VS_OUT, 392 IP_DEFRAG_VS_FWD, 393 IP_DEFRAG_AF_PACKET, 394 IP_DEFRAG_MACVLAN, 395 }; 396 397 int ip_defrag(struct sk_buff *skb, u32 user); 398 #ifdef CONFIG_INET 399 struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user); 400 #else 401 static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) 402 { 403 return skb; 404 } 405 #endif 406 int ip_frag_mem(struct net *net); 407 int ip_frag_nqueues(struct net *net); 408 409 /* 410 * Functions provided by ip_forward.c 411 */ 412 413 extern int ip_forward(struct sk_buff *skb); 414 415 /* 416 * Functions provided by ip_options.c 417 */ 418 419 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 420 __be32 daddr, struct rtable *rt, int is_frag); 421 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 422 extern void ip_options_fragment(struct sk_buff *skb); 423 extern int ip_options_compile(struct net *net, 424 struct ip_options *opt, struct sk_buff *skb); 425 extern int ip_options_get(struct net *net, struct ip_options_rcu **optp, 426 unsigned char *data, int optlen); 427 extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp, 428 unsigned char __user *data, int optlen); 429 extern void ip_options_undo(struct ip_options * opt); 430 extern void ip_forward_options(struct sk_buff *skb); 431 extern int ip_options_rcv_srr(struct sk_buff *skb); 432 433 /* 434 * Functions provided by ip_sockglue.c 435 */ 436 437 extern void ipv4_pktinfo_prepare(struct sk_buff *skb); 438 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 439 extern int ip_cmsg_send(struct net *net, 440 struct msghdr *msg, struct ipcm_cookie *ipc); 441 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); 442 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 443 extern int compat_ip_setsockopt(struct sock *sk, int level, 444 int optname, char __user *optval, unsigned int optlen); 445 extern int compat_ip_getsockopt(struct sock *sk, int level, 446 int optname, char __user *optval, int __user *optlen); 447 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 448 449 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 450 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 451 __be16 port, u32 info, u8 *payload); 452 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 453 u32 info); 454 455 #ifdef CONFIG_PROC_FS 456 extern int ip_misc_proc_init(void); 457 #endif 458 459 #endif /* _IP_H */ 460