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