1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Definitions for the IP module. 8 * 9 * Version: @(#)ip.h 1.0.2 05/07/93 10 * 11 * Authors: Ross Biro 12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 13 * Alan Cox, <gw4pts@gw4pts.ampr.org> 14 * 15 * Changes: 16 * Mike McLagan : Routing by source 17 */ 18 #ifndef _IP_H 19 #define _IP_H 20 21 #include <linux/types.h> 22 #include <linux/ip.h> 23 #include <linux/in.h> 24 #include <linux/skbuff.h> 25 #include <linux/jhash.h> 26 #include <linux/sockptr.h> 27 28 #include <net/inet_sock.h> 29 #include <net/route.h> 30 #include <net/snmp.h> 31 #include <net/flow.h> 32 #include <net/flow_dissector.h> 33 #include <net/netns/hash.h> 34 #include <net/lwtunnel.h> 35 36 #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */ 37 #define IPV4_MIN_MTU 68 /* RFC 791 */ 38 39 extern unsigned int sysctl_fib_sync_mem; 40 extern unsigned int sysctl_fib_sync_mem_min; 41 extern unsigned int sysctl_fib_sync_mem_max; 42 43 struct sock; 44 45 struct inet_skb_parm { 46 int iif; 47 struct ip_options opt; /* Compiled IP options */ 48 u16 flags; 49 50 #define IPSKB_FORWARDED BIT(0) 51 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1) 52 #define IPSKB_XFRM_TRANSFORMED BIT(2) 53 #define IPSKB_FRAG_COMPLETE BIT(3) 54 #define IPSKB_REROUTED BIT(4) 55 #define IPSKB_DOREDIRECT BIT(5) 56 #define IPSKB_FRAG_PMTU BIT(6) 57 #define IPSKB_L3SLAVE BIT(7) 58 59 u16 frag_max_size; 60 }; 61 62 static inline bool ipv4_l3mdev_skb(u16 flags) 63 { 64 return !!(flags & IPSKB_L3SLAVE); 65 } 66 67 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 68 { 69 return ip_hdr(skb)->ihl * 4; 70 } 71 72 struct ipcm_cookie { 73 struct sockcm_cookie sockc; 74 __be32 addr; 75 int oif; 76 struct ip_options_rcu *opt; 77 __u8 ttl; 78 __s16 tos; 79 char priority; 80 __u16 gso_size; 81 }; 82 83 static inline void ipcm_init(struct ipcm_cookie *ipcm) 84 { 85 *ipcm = (struct ipcm_cookie) { .tos = -1 }; 86 } 87 88 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm, 89 const struct inet_sock *inet) 90 { 91 ipcm_init(ipcm); 92 93 ipcm->sockc.mark = inet->sk.sk_mark; 94 ipcm->sockc.tsflags = inet->sk.sk_tsflags; 95 ipcm->oif = inet->sk.sk_bound_dev_if; 96 ipcm->addr = inet->inet_saddr; 97 } 98 99 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 100 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb)) 101 102 /* return enslaved device index if relevant */ 103 static inline int inet_sdif(const struct sk_buff *skb) 104 { 105 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 106 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 107 return IPCB(skb)->iif; 108 #endif 109 return 0; 110 } 111 112 /* Special input handler for packets caught by router alert option. 113 They are selected only by protocol field, and then processed likely 114 local ones; but only if someone wants them! Otherwise, router 115 not running rsvpd will kill RSVP. 116 117 It is user level problem, what it will make with them. 118 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)), 119 but receiver should be enough clever f.e. to forward mtrace requests, 120 sent to multicast group to reach destination designated router. 121 */ 122 123 struct ip_ra_chain { 124 struct ip_ra_chain __rcu *next; 125 struct sock *sk; 126 union { 127 void (*destructor)(struct sock *); 128 struct sock *saved_sk; 129 }; 130 struct rcu_head rcu; 131 }; 132 133 /* IP flags. */ 134 #define IP_CE 0x8000 /* Flag: "Congestion" */ 135 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 136 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 137 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 138 139 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 140 141 struct msghdr; 142 struct net_device; 143 struct packet_type; 144 struct rtable; 145 struct sockaddr; 146 147 int igmp_mc_init(void); 148 149 /* 150 * Functions provided by ip.c 151 */ 152 153 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, 154 __be32 saddr, __be32 daddr, 155 struct ip_options_rcu *opt, u8 tos); 156 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 157 struct net_device *orig_dev); 158 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 159 struct net_device *orig_dev); 160 int ip_local_deliver(struct sk_buff *skb); 161 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto); 162 int ip_mr_input(struct sk_buff *skb); 163 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); 164 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); 165 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 166 int (*output)(struct net *, struct sock *, struct sk_buff *)); 167 168 struct ip_fraglist_iter { 169 struct sk_buff *frag; 170 struct iphdr *iph; 171 int offset; 172 unsigned int hlen; 173 }; 174 175 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, 176 unsigned int hlen, struct ip_fraglist_iter *iter); 177 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); 178 179 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) 180 { 181 struct sk_buff *skb = iter->frag; 182 183 iter->frag = skb->next; 184 skb_mark_not_on_list(skb); 185 186 return skb; 187 } 188 189 struct ip_frag_state { 190 bool DF; 191 unsigned int hlen; 192 unsigned int ll_rs; 193 unsigned int mtu; 194 unsigned int left; 195 int offset; 196 int ptr; 197 __be16 not_last_frag; 198 }; 199 200 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs, 201 unsigned int mtu, bool DF, struct ip_frag_state *state); 202 struct sk_buff *ip_frag_next(struct sk_buff *skb, 203 struct ip_frag_state *state); 204 205 void ip_send_check(struct iphdr *ip); 206 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 207 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 208 209 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 210 __u8 tos); 211 void ip_init(void); 212 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 213 int getfrag(void *from, char *to, int offset, int len, 214 int odd, struct sk_buff *skb), 215 void *from, int len, int protolen, 216 struct ipcm_cookie *ipc, 217 struct rtable **rt, 218 unsigned int flags); 219 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 220 struct sk_buff *skb); 221 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 222 int offset, size_t size, int flags); 223 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 224 struct sk_buff_head *queue, 225 struct inet_cork *cork); 226 int ip_send_skb(struct net *net, struct sk_buff *skb); 227 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 228 void ip_flush_pending_frames(struct sock *sk); 229 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 230 int getfrag(void *from, char *to, int offset, 231 int len, int odd, struct sk_buff *skb), 232 void *from, int length, int transhdrlen, 233 struct ipcm_cookie *ipc, struct rtable **rtp, 234 struct inet_cork *cork, unsigned int flags); 235 236 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 237 238 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 239 { 240 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 241 } 242 243 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet) 244 { 245 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos); 246 } 247 248 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk) 249 { 250 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk); 251 } 252 253 /* datagram.c */ 254 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 255 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 256 257 void ip4_datagram_release_cb(struct sock *sk); 258 259 struct ip_reply_arg { 260 struct kvec iov[1]; 261 int flags; 262 __wsum csum; 263 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 264 /* -1 if not needed */ 265 int bound_dev_if; 266 u8 tos; 267 kuid_t uid; 268 }; 269 270 #define IP_REPLY_ARG_NOSRCCHECK 1 271 272 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 273 { 274 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 275 } 276 277 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, 278 const struct ip_options *sopt, 279 __be32 daddr, __be32 saddr, 280 const struct ip_reply_arg *arg, 281 unsigned int len, u64 transmit_time); 282 283 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 284 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) 285 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 286 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 287 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 288 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 289 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 290 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) 291 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 292 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 293 294 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct); 295 unsigned long snmp_fold_field(void __percpu *mib, int offt); 296 #if BITS_PER_LONG==32 297 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 298 size_t syncp_offset); 299 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); 300 #else 301 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 302 size_t syncp_offset) 303 { 304 return snmp_get_cpu_field(mib, cpu, offct); 305 306 } 307 308 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) 309 { 310 return snmp_fold_field(mib, offt); 311 } 312 #endif 313 314 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \ 315 { \ 316 int i, c; \ 317 for_each_possible_cpu(c) { \ 318 for (i = 0; stats_list[i].name; i++) \ 319 buff64[i] += snmp_get_cpu_field64( \ 320 mib_statistic, \ 321 c, stats_list[i].entry, \ 322 offset); \ 323 } \ 324 } 325 326 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \ 327 { \ 328 int i, c; \ 329 for_each_possible_cpu(c) { \ 330 for (i = 0; stats_list[i].name; i++) \ 331 buff[i] += snmp_get_cpu_field( \ 332 mib_statistic, \ 333 c, stats_list[i].entry); \ 334 } \ 335 } 336 337 void inet_get_local_port_range(struct net *net, int *low, int *high); 338 339 #ifdef CONFIG_SYSCTL 340 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 341 { 342 if (!net->ipv4.sysctl_local_reserved_ports) 343 return false; 344 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 345 } 346 347 static inline bool sysctl_dev_name_is_allowed(const char *name) 348 { 349 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 350 } 351 352 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 353 { 354 return port < net->ipv4.sysctl_ip_prot_sock; 355 } 356 357 #else 358 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 359 { 360 return false; 361 } 362 363 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 364 { 365 return port < PROT_SOCK; 366 } 367 #endif 368 369 __be32 inet_current_timestamp(void); 370 371 /* From inetpeer.c */ 372 extern int inet_peer_threshold; 373 extern int inet_peer_minttl; 374 extern int inet_peer_maxttl; 375 376 void ipfrag_init(void); 377 378 void ip_static_sysctl_init(void); 379 380 #define IP4_REPLY_MARK(net, mark) \ 381 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0) 382 383 static inline bool ip_is_fragment(const struct iphdr *iph) 384 { 385 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 386 } 387 388 #ifdef CONFIG_INET 389 #include <net/dst.h> 390 391 /* The function in 2.2 was invalid, producing wrong result for 392 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 393 static inline 394 int ip_decrease_ttl(struct iphdr *iph) 395 { 396 u32 check = (__force u32)iph->check; 397 check += (__force u32)htons(0x0100); 398 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 399 return --iph->ttl; 400 } 401 402 static inline int ip_mtu_locked(const struct dst_entry *dst) 403 { 404 const struct rtable *rt = (const struct rtable *)dst; 405 406 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 407 } 408 409 static inline 410 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 411 { 412 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 413 414 return pmtudisc == IP_PMTUDISC_DO || 415 (pmtudisc == IP_PMTUDISC_WANT && 416 !ip_mtu_locked(dst)); 417 } 418 419 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 420 { 421 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE && 422 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT; 423 } 424 425 static inline bool ip_sk_use_pmtu(const struct sock *sk) 426 { 427 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE; 428 } 429 430 static inline bool ip_sk_ignore_df(const struct sock *sk) 431 { 432 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO || 433 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT; 434 } 435 436 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 437 bool forwarding) 438 { 439 struct net *net = dev_net(dst->dev); 440 unsigned int mtu; 441 442 if (net->ipv4.sysctl_ip_fwd_use_pmtu || 443 ip_mtu_locked(dst) || 444 !forwarding) 445 return dst_mtu(dst); 446 447 /* 'forwarding = true' case should always honour route mtu */ 448 mtu = dst_metric_raw(dst, RTAX_MTU); 449 if (!mtu) 450 mtu = min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU); 451 452 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 453 } 454 455 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 456 const struct sk_buff *skb) 457 { 458 unsigned int mtu; 459 460 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 461 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 462 463 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); 464 } 465 466 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); 467 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 468 } 469 470 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx, 471 int fc_mx_len, 472 struct netlink_ext_ack *extack); 473 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 474 { 475 if (fib_metrics != &dst_default_metrics && 476 refcount_dec_and_test(&fib_metrics->refcnt)) 477 kfree(fib_metrics); 478 } 479 480 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 481 static inline 482 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 483 { 484 dst_init_metrics(dst, fib_metrics->metrics, true); 485 486 if (fib_metrics != &dst_default_metrics) { 487 dst->_metrics |= DST_METRICS_REFCOUNTED; 488 refcount_inc(&fib_metrics->refcnt); 489 } 490 } 491 492 static inline 493 void ip_dst_metrics_put(struct dst_entry *dst) 494 { 495 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 496 497 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 498 kfree(p); 499 } 500 501 u32 ip_idents_reserve(u32 hash, int segs); 502 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); 503 504 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, 505 struct sock *sk, int segs) 506 { 507 struct iphdr *iph = ip_hdr(skb); 508 509 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 510 /* This is only to work around buggy Windows95/2000 511 * VJ compression implementations. If the ID field 512 * does not change, they drop every other packet in 513 * a TCP stream using header compression. 514 */ 515 if (sk && inet_sk(sk)->inet_daddr) { 516 iph->id = htons(inet_sk(sk)->inet_id); 517 inet_sk(sk)->inet_id += segs; 518 } else { 519 iph->id = 0; 520 } 521 } else { 522 __ip_select_ident(net, iph, segs); 523 } 524 } 525 526 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 527 struct sock *sk) 528 { 529 ip_select_ident_segs(net, skb, sk, 1); 530 } 531 532 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 533 { 534 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 535 skb->len, proto, 0); 536 } 537 538 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 539 * Equivalent to : flow->v4addrs.src = iph->saddr; 540 * flow->v4addrs.dst = iph->daddr; 541 */ 542 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 543 const struct iphdr *iph) 544 { 545 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 546 offsetof(typeof(flow->addrs), v4addrs.src) + 547 sizeof(flow->addrs.v4addrs.src)); 548 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs)); 549 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 550 } 551 552 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto) 553 { 554 const struct iphdr *iph = skb_gro_network_header(skb); 555 556 return csum_tcpudp_nofold(iph->saddr, iph->daddr, 557 skb_gro_len(skb), proto, 0); 558 } 559 560 /* 561 * Map a multicast IP onto multicast MAC for type ethernet. 562 */ 563 564 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 565 { 566 __u32 addr=ntohl(naddr); 567 buf[0]=0x01; 568 buf[1]=0x00; 569 buf[2]=0x5e; 570 buf[5]=addr&0xFF; 571 addr>>=8; 572 buf[4]=addr&0xFF; 573 addr>>=8; 574 buf[3]=addr&0x7F; 575 } 576 577 /* 578 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 579 * Leave P_Key as 0 to be filled in by driver. 580 */ 581 582 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 583 { 584 __u32 addr; 585 unsigned char scope = broadcast[5] & 0xF; 586 587 buf[0] = 0; /* Reserved */ 588 buf[1] = 0xff; /* Multicast QPN */ 589 buf[2] = 0xff; 590 buf[3] = 0xff; 591 addr = ntohl(naddr); 592 buf[4] = 0xff; 593 buf[5] = 0x10 | scope; /* scope from broadcast address */ 594 buf[6] = 0x40; /* IPv4 signature */ 595 buf[7] = 0x1b; 596 buf[8] = broadcast[8]; /* P_Key */ 597 buf[9] = broadcast[9]; 598 buf[10] = 0; 599 buf[11] = 0; 600 buf[12] = 0; 601 buf[13] = 0; 602 buf[14] = 0; 603 buf[15] = 0; 604 buf[19] = addr & 0xff; 605 addr >>= 8; 606 buf[18] = addr & 0xff; 607 addr >>= 8; 608 buf[17] = addr & 0xff; 609 addr >>= 8; 610 buf[16] = addr & 0x0f; 611 } 612 613 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 614 { 615 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 616 memcpy(buf, broadcast, 4); 617 else 618 memcpy(buf, &naddr, sizeof(naddr)); 619 } 620 621 #if IS_ENABLED(CONFIG_IPV6) 622 #include <linux/ipv6.h> 623 #endif 624 625 static __inline__ void inet_reset_saddr(struct sock *sk) 626 { 627 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 628 #if IS_ENABLED(CONFIG_IPV6) 629 if (sk->sk_family == PF_INET6) { 630 struct ipv6_pinfo *np = inet6_sk(sk); 631 632 memset(&np->saddr, 0, sizeof(np->saddr)); 633 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 634 } 635 #endif 636 } 637 638 #endif 639 640 static inline unsigned int ipv4_addr_hash(__be32 ip) 641 { 642 return (__force unsigned int) ip; 643 } 644 645 static inline u32 ipv4_portaddr_hash(const struct net *net, 646 __be32 saddr, 647 unsigned int port) 648 { 649 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 650 } 651 652 bool ip_call_ra_chain(struct sk_buff *skb); 653 654 /* 655 * Functions provided by ip_fragment.c 656 */ 657 658 enum ip_defrag_users { 659 IP_DEFRAG_LOCAL_DELIVER, 660 IP_DEFRAG_CALL_RA_CHAIN, 661 IP_DEFRAG_CONNTRACK_IN, 662 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 663 IP_DEFRAG_CONNTRACK_OUT, 664 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 665 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 666 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 667 IP_DEFRAG_VS_IN, 668 IP_DEFRAG_VS_OUT, 669 IP_DEFRAG_VS_FWD, 670 IP_DEFRAG_AF_PACKET, 671 IP_DEFRAG_MACVLAN, 672 }; 673 674 /* Return true if the value of 'user' is between 'lower_bond' 675 * and 'upper_bond' inclusively. 676 */ 677 static inline bool ip_defrag_user_in_between(u32 user, 678 enum ip_defrag_users lower_bond, 679 enum ip_defrag_users upper_bond) 680 { 681 return user >= lower_bond && user <= upper_bond; 682 } 683 684 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 685 #ifdef CONFIG_INET 686 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 687 #else 688 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 689 { 690 return skb; 691 } 692 #endif 693 694 /* 695 * Functions provided by ip_forward.c 696 */ 697 698 int ip_forward(struct sk_buff *skb); 699 700 /* 701 * Functions provided by ip_options.c 702 */ 703 704 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 705 __be32 daddr, struct rtable *rt, int is_frag); 706 707 int __ip_options_echo(struct net *net, struct ip_options *dopt, 708 struct sk_buff *skb, const struct ip_options *sopt); 709 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 710 struct sk_buff *skb) 711 { 712 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 713 } 714 715 void ip_options_fragment(struct sk_buff *skb); 716 int __ip_options_compile(struct net *net, struct ip_options *opt, 717 struct sk_buff *skb, __be32 *info); 718 int ip_options_compile(struct net *net, struct ip_options *opt, 719 struct sk_buff *skb); 720 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 721 sockptr_t data, int optlen); 722 void ip_options_undo(struct ip_options *opt); 723 void ip_forward_options(struct sk_buff *skb); 724 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 725 726 /* 727 * Functions provided by ip_sockglue.c 728 */ 729 730 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); 731 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 732 struct sk_buff *skb, int tlen, int offset); 733 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 734 struct ipcm_cookie *ipc, bool allow_ipv6); 735 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 736 unsigned int optlen); 737 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 738 int __user *optlen); 739 int ip_ra_control(struct sock *sk, unsigned char on, 740 void (*destructor)(struct sock *)); 741 742 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 743 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 744 u32 info, u8 *payload); 745 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 746 u32 info); 747 748 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 749 { 750 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 751 } 752 753 bool icmp_global_allow(void); 754 extern int sysctl_icmp_msgs_per_sec; 755 extern int sysctl_icmp_msgs_burst; 756 757 #ifdef CONFIG_PROC_FS 758 int ip_misc_proc_init(void); 759 #endif 760 761 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 762 struct netlink_ext_ack *extack); 763 764 static inline bool inetdev_valid_mtu(unsigned int mtu) 765 { 766 return likely(mtu >= IPV4_MIN_MTU); 767 } 768 769 void ip_sock_set_freebind(struct sock *sk); 770 int ip_sock_set_mtu_discover(struct sock *sk, int val); 771 void ip_sock_set_pktinfo(struct sock *sk); 772 void ip_sock_set_recverr(struct sock *sk); 773 void ip_sock_set_tos(struct sock *sk, int val); 774 775 #endif /* _IP_H */ 776