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 #include <linux/static_key.h> 28 29 #include <net/inet_sock.h> 30 #include <net/route.h> 31 #include <net/snmp.h> 32 #include <net/flow.h> 33 #include <net/flow_dissector.h> 34 #include <net/netns/hash.h> 35 #include <net/lwtunnel.h> 36 37 #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */ 38 #define IPV4_MIN_MTU 68 /* RFC 791 */ 39 40 extern unsigned int sysctl_fib_sync_mem; 41 extern unsigned int sysctl_fib_sync_mem_min; 42 extern unsigned int sysctl_fib_sync_mem_max; 43 44 struct sock; 45 46 struct inet_skb_parm { 47 int iif; 48 struct ip_options opt; /* Compiled IP options */ 49 u16 flags; 50 51 #define IPSKB_FORWARDED BIT(0) 52 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1) 53 #define IPSKB_XFRM_TRANSFORMED BIT(2) 54 #define IPSKB_FRAG_COMPLETE BIT(3) 55 #define IPSKB_REROUTED BIT(4) 56 #define IPSKB_DOREDIRECT BIT(5) 57 #define IPSKB_FRAG_PMTU BIT(6) 58 #define IPSKB_L3SLAVE BIT(7) 59 60 u16 frag_max_size; 61 }; 62 63 static inline bool ipv4_l3mdev_skb(u16 flags) 64 { 65 return !!(flags & IPSKB_L3SLAVE); 66 } 67 68 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 69 { 70 return ip_hdr(skb)->ihl * 4; 71 } 72 73 struct ipcm_cookie { 74 struct sockcm_cookie sockc; 75 __be32 addr; 76 int oif; 77 struct ip_options_rcu *opt; 78 __u8 ttl; 79 __s16 tos; 80 char priority; 81 __u16 gso_size; 82 }; 83 84 static inline void ipcm_init(struct ipcm_cookie *ipcm) 85 { 86 *ipcm = (struct ipcm_cookie) { .tos = -1 }; 87 } 88 89 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm, 90 const struct inet_sock *inet) 91 { 92 ipcm_init(ipcm); 93 94 ipcm->sockc.mark = inet->sk.sk_mark; 95 ipcm->sockc.tsflags = inet->sk.sk_tsflags; 96 ipcm->oif = inet->sk.sk_bound_dev_if; 97 ipcm->addr = inet->inet_saddr; 98 } 99 100 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 101 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb)) 102 103 /* return enslaved device index if relevant */ 104 static inline int inet_sdif(const struct sk_buff *skb) 105 { 106 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 107 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 108 return IPCB(skb)->iif; 109 #endif 110 return 0; 111 } 112 113 /* Special input handler for packets caught by router alert option. 114 They are selected only by protocol field, and then processed likely 115 local ones; but only if someone wants them! Otherwise, router 116 not running rsvpd will kill RSVP. 117 118 It is user level problem, what it will make with them. 119 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)), 120 but receiver should be enough clever f.e. to forward mtrace requests, 121 sent to multicast group to reach destination designated router. 122 */ 123 124 struct ip_ra_chain { 125 struct ip_ra_chain __rcu *next; 126 struct sock *sk; 127 union { 128 void (*destructor)(struct sock *); 129 struct sock *saved_sk; 130 }; 131 struct rcu_head rcu; 132 }; 133 134 /* IP flags. */ 135 #define IP_CE 0x8000 /* Flag: "Congestion" */ 136 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 137 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 138 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 139 140 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 141 142 struct msghdr; 143 struct net_device; 144 struct packet_type; 145 struct rtable; 146 struct sockaddr; 147 148 int igmp_mc_init(void); 149 150 /* 151 * Functions provided by ip.c 152 */ 153 154 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, 155 __be32 saddr, __be32 daddr, 156 struct ip_options_rcu *opt, u8 tos); 157 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 158 struct net_device *orig_dev); 159 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 160 struct net_device *orig_dev); 161 int ip_local_deliver(struct sk_buff *skb); 162 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto); 163 int ip_mr_input(struct sk_buff *skb); 164 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); 165 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); 166 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 167 int (*output)(struct net *, struct sock *, struct sk_buff *)); 168 169 struct ip_fraglist_iter { 170 struct sk_buff *frag; 171 struct iphdr *iph; 172 int offset; 173 unsigned int hlen; 174 }; 175 176 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, 177 unsigned int hlen, struct ip_fraglist_iter *iter); 178 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); 179 180 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) 181 { 182 struct sk_buff *skb = iter->frag; 183 184 iter->frag = skb->next; 185 skb_mark_not_on_list(skb); 186 187 return skb; 188 } 189 190 struct ip_frag_state { 191 bool DF; 192 unsigned int hlen; 193 unsigned int ll_rs; 194 unsigned int mtu; 195 unsigned int left; 196 int offset; 197 int ptr; 198 __be16 not_last_frag; 199 }; 200 201 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs, 202 unsigned int mtu, bool DF, struct ip_frag_state *state); 203 struct sk_buff *ip_frag_next(struct sk_buff *skb, 204 struct ip_frag_state *state); 205 206 void ip_send_check(struct iphdr *ip); 207 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 208 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 209 210 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 211 __u8 tos); 212 void ip_init(void); 213 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 214 int getfrag(void *from, char *to, int offset, int len, 215 int odd, struct sk_buff *skb), 216 void *from, int len, int protolen, 217 struct ipcm_cookie *ipc, 218 struct rtable **rt, 219 unsigned int flags); 220 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 221 struct sk_buff *skb); 222 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 223 int offset, size_t size, int flags); 224 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 225 struct sk_buff_head *queue, 226 struct inet_cork *cork); 227 int ip_send_skb(struct net *net, struct sk_buff *skb); 228 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 229 void ip_flush_pending_frames(struct sock *sk); 230 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 231 int getfrag(void *from, char *to, int offset, 232 int len, int odd, struct sk_buff *skb), 233 void *from, int length, int transhdrlen, 234 struct ipcm_cookie *ipc, struct rtable **rtp, 235 struct inet_cork *cork, unsigned int flags); 236 237 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 238 239 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 240 { 241 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 242 } 243 244 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet) 245 { 246 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos); 247 } 248 249 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk) 250 { 251 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk); 252 } 253 254 /* datagram.c */ 255 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 256 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 257 258 void ip4_datagram_release_cb(struct sock *sk); 259 260 struct ip_reply_arg { 261 struct kvec iov[1]; 262 int flags; 263 __wsum csum; 264 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 265 /* -1 if not needed */ 266 int bound_dev_if; 267 u8 tos; 268 kuid_t uid; 269 }; 270 271 #define IP_REPLY_ARG_NOSRCCHECK 1 272 273 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 274 { 275 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 276 } 277 278 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, 279 const struct ip_options *sopt, 280 __be32 daddr, __be32 saddr, 281 const struct ip_reply_arg *arg, 282 unsigned int len, u64 transmit_time); 283 284 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 285 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) 286 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 287 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_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 __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 290 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 291 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) 292 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 293 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 294 295 static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt) 296 { 297 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt); 298 } 299 300 unsigned long snmp_fold_field(void __percpu *mib, int offt); 301 #if BITS_PER_LONG==32 302 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 303 size_t syncp_offset); 304 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); 305 #else 306 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 307 size_t syncp_offset) 308 { 309 return snmp_get_cpu_field(mib, cpu, offct); 310 311 } 312 313 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) 314 { 315 return snmp_fold_field(mib, offt); 316 } 317 #endif 318 319 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \ 320 { \ 321 int i, c; \ 322 for_each_possible_cpu(c) { \ 323 for (i = 0; stats_list[i].name; i++) \ 324 buff64[i] += snmp_get_cpu_field64( \ 325 mib_statistic, \ 326 c, stats_list[i].entry, \ 327 offset); \ 328 } \ 329 } 330 331 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \ 332 { \ 333 int i, c; \ 334 for_each_possible_cpu(c) { \ 335 for (i = 0; stats_list[i].name; i++) \ 336 buff[i] += snmp_get_cpu_field( \ 337 mib_statistic, \ 338 c, stats_list[i].entry); \ 339 } \ 340 } 341 342 void inet_get_local_port_range(struct net *net, int *low, int *high); 343 344 #ifdef CONFIG_SYSCTL 345 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 346 { 347 if (!net->ipv4.sysctl_local_reserved_ports) 348 return false; 349 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 350 } 351 352 static inline bool sysctl_dev_name_is_allowed(const char *name) 353 { 354 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 355 } 356 357 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 358 { 359 return port < net->ipv4.sysctl_ip_prot_sock; 360 } 361 362 #else 363 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 364 { 365 return false; 366 } 367 368 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 369 { 370 return port < PROT_SOCK; 371 } 372 #endif 373 374 __be32 inet_current_timestamp(void); 375 376 /* From inetpeer.c */ 377 extern int inet_peer_threshold; 378 extern int inet_peer_minttl; 379 extern int inet_peer_maxttl; 380 381 void ipfrag_init(void); 382 383 void ip_static_sysctl_init(void); 384 385 #define IP4_REPLY_MARK(net, mark) \ 386 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0) 387 388 static inline bool ip_is_fragment(const struct iphdr *iph) 389 { 390 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 391 } 392 393 #ifdef CONFIG_INET 394 #include <net/dst.h> 395 396 /* The function in 2.2 was invalid, producing wrong result for 397 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 398 static inline 399 int ip_decrease_ttl(struct iphdr *iph) 400 { 401 u32 check = (__force u32)iph->check; 402 check += (__force u32)htons(0x0100); 403 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 404 return --iph->ttl; 405 } 406 407 static inline int ip_mtu_locked(const struct dst_entry *dst) 408 { 409 const struct rtable *rt = (const struct rtable *)dst; 410 411 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 412 } 413 414 static inline 415 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 416 { 417 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 418 419 return pmtudisc == IP_PMTUDISC_DO || 420 (pmtudisc == IP_PMTUDISC_WANT && 421 !ip_mtu_locked(dst)); 422 } 423 424 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 425 { 426 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE && 427 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT; 428 } 429 430 static inline bool ip_sk_use_pmtu(const struct sock *sk) 431 { 432 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE; 433 } 434 435 static inline bool ip_sk_ignore_df(const struct sock *sk) 436 { 437 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO || 438 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT; 439 } 440 441 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 442 bool forwarding) 443 { 444 const struct rtable *rt = container_of(dst, struct rtable, dst); 445 struct net *net = dev_net(dst->dev); 446 unsigned int mtu; 447 448 if (net->ipv4.sysctl_ip_fwd_use_pmtu || 449 ip_mtu_locked(dst) || 450 !forwarding) { 451 mtu = rt->rt_pmtu; 452 if (mtu && time_before(jiffies, rt->dst.expires)) 453 goto out; 454 } 455 456 /* 'forwarding = true' case should always honour route mtu */ 457 mtu = dst_metric_raw(dst, RTAX_MTU); 458 if (mtu) 459 goto out; 460 461 mtu = READ_ONCE(dst->dev->mtu); 462 463 if (unlikely(ip_mtu_locked(dst))) { 464 if (rt->rt_uses_gateway && mtu > 576) 465 mtu = 576; 466 } 467 468 out: 469 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 470 471 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 472 } 473 474 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 475 const struct sk_buff *skb) 476 { 477 unsigned int mtu; 478 479 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 480 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 481 482 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); 483 } 484 485 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); 486 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 487 } 488 489 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx, 490 int fc_mx_len, 491 struct netlink_ext_ack *extack); 492 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 493 { 494 if (fib_metrics != &dst_default_metrics && 495 refcount_dec_and_test(&fib_metrics->refcnt)) 496 kfree(fib_metrics); 497 } 498 499 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 500 static inline 501 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 502 { 503 dst_init_metrics(dst, fib_metrics->metrics, true); 504 505 if (fib_metrics != &dst_default_metrics) { 506 dst->_metrics |= DST_METRICS_REFCOUNTED; 507 refcount_inc(&fib_metrics->refcnt); 508 } 509 } 510 511 static inline 512 void ip_dst_metrics_put(struct dst_entry *dst) 513 { 514 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 515 516 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 517 kfree(p); 518 } 519 520 u32 ip_idents_reserve(u32 hash, int segs); 521 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); 522 523 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, 524 struct sock *sk, int segs) 525 { 526 struct iphdr *iph = ip_hdr(skb); 527 528 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 529 /* This is only to work around buggy Windows95/2000 530 * VJ compression implementations. If the ID field 531 * does not change, they drop every other packet in 532 * a TCP stream using header compression. 533 */ 534 if (sk && inet_sk(sk)->inet_daddr) { 535 iph->id = htons(inet_sk(sk)->inet_id); 536 inet_sk(sk)->inet_id += segs; 537 } else { 538 iph->id = 0; 539 } 540 } else { 541 __ip_select_ident(net, iph, segs); 542 } 543 } 544 545 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 546 struct sock *sk) 547 { 548 ip_select_ident_segs(net, skb, sk, 1); 549 } 550 551 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 552 { 553 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 554 skb->len, proto, 0); 555 } 556 557 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 558 * Equivalent to : flow->v4addrs.src = iph->saddr; 559 * flow->v4addrs.dst = iph->daddr; 560 */ 561 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 562 const struct iphdr *iph) 563 { 564 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 565 offsetof(typeof(flow->addrs), v4addrs.src) + 566 sizeof(flow->addrs.v4addrs.src)); 567 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs)); 568 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 569 } 570 571 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto) 572 { 573 const struct iphdr *iph = skb_gro_network_header(skb); 574 575 return csum_tcpudp_nofold(iph->saddr, iph->daddr, 576 skb_gro_len(skb), proto, 0); 577 } 578 579 /* 580 * Map a multicast IP onto multicast MAC for type ethernet. 581 */ 582 583 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 584 { 585 __u32 addr=ntohl(naddr); 586 buf[0]=0x01; 587 buf[1]=0x00; 588 buf[2]=0x5e; 589 buf[5]=addr&0xFF; 590 addr>>=8; 591 buf[4]=addr&0xFF; 592 addr>>=8; 593 buf[3]=addr&0x7F; 594 } 595 596 /* 597 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 598 * Leave P_Key as 0 to be filled in by driver. 599 */ 600 601 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 602 { 603 __u32 addr; 604 unsigned char scope = broadcast[5] & 0xF; 605 606 buf[0] = 0; /* Reserved */ 607 buf[1] = 0xff; /* Multicast QPN */ 608 buf[2] = 0xff; 609 buf[3] = 0xff; 610 addr = ntohl(naddr); 611 buf[4] = 0xff; 612 buf[5] = 0x10 | scope; /* scope from broadcast address */ 613 buf[6] = 0x40; /* IPv4 signature */ 614 buf[7] = 0x1b; 615 buf[8] = broadcast[8]; /* P_Key */ 616 buf[9] = broadcast[9]; 617 buf[10] = 0; 618 buf[11] = 0; 619 buf[12] = 0; 620 buf[13] = 0; 621 buf[14] = 0; 622 buf[15] = 0; 623 buf[19] = addr & 0xff; 624 addr >>= 8; 625 buf[18] = addr & 0xff; 626 addr >>= 8; 627 buf[17] = addr & 0xff; 628 addr >>= 8; 629 buf[16] = addr & 0x0f; 630 } 631 632 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 633 { 634 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 635 memcpy(buf, broadcast, 4); 636 else 637 memcpy(buf, &naddr, sizeof(naddr)); 638 } 639 640 #if IS_ENABLED(CONFIG_IPV6) 641 #include <linux/ipv6.h> 642 #endif 643 644 static __inline__ void inet_reset_saddr(struct sock *sk) 645 { 646 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 647 #if IS_ENABLED(CONFIG_IPV6) 648 if (sk->sk_family == PF_INET6) { 649 struct ipv6_pinfo *np = inet6_sk(sk); 650 651 memset(&np->saddr, 0, sizeof(np->saddr)); 652 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 653 } 654 #endif 655 } 656 657 #endif 658 659 static inline unsigned int ipv4_addr_hash(__be32 ip) 660 { 661 return (__force unsigned int) ip; 662 } 663 664 static inline u32 ipv4_portaddr_hash(const struct net *net, 665 __be32 saddr, 666 unsigned int port) 667 { 668 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 669 } 670 671 bool ip_call_ra_chain(struct sk_buff *skb); 672 673 /* 674 * Functions provided by ip_fragment.c 675 */ 676 677 enum ip_defrag_users { 678 IP_DEFRAG_LOCAL_DELIVER, 679 IP_DEFRAG_CALL_RA_CHAIN, 680 IP_DEFRAG_CONNTRACK_IN, 681 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 682 IP_DEFRAG_CONNTRACK_OUT, 683 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 684 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 685 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 686 IP_DEFRAG_VS_IN, 687 IP_DEFRAG_VS_OUT, 688 IP_DEFRAG_VS_FWD, 689 IP_DEFRAG_AF_PACKET, 690 IP_DEFRAG_MACVLAN, 691 }; 692 693 /* Return true if the value of 'user' is between 'lower_bond' 694 * and 'upper_bond' inclusively. 695 */ 696 static inline bool ip_defrag_user_in_between(u32 user, 697 enum ip_defrag_users lower_bond, 698 enum ip_defrag_users upper_bond) 699 { 700 return user >= lower_bond && user <= upper_bond; 701 } 702 703 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 704 #ifdef CONFIG_INET 705 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 706 #else 707 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 708 { 709 return skb; 710 } 711 #endif 712 713 /* 714 * Functions provided by ip_forward.c 715 */ 716 717 int ip_forward(struct sk_buff *skb); 718 719 /* 720 * Functions provided by ip_options.c 721 */ 722 723 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 724 __be32 daddr, struct rtable *rt, int is_frag); 725 726 int __ip_options_echo(struct net *net, struct ip_options *dopt, 727 struct sk_buff *skb, const struct ip_options *sopt); 728 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 729 struct sk_buff *skb) 730 { 731 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 732 } 733 734 void ip_options_fragment(struct sk_buff *skb); 735 int __ip_options_compile(struct net *net, struct ip_options *opt, 736 struct sk_buff *skb, __be32 *info); 737 int ip_options_compile(struct net *net, struct ip_options *opt, 738 struct sk_buff *skb); 739 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 740 sockptr_t data, int optlen); 741 void ip_options_undo(struct ip_options *opt); 742 void ip_forward_options(struct sk_buff *skb); 743 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 744 745 /* 746 * Functions provided by ip_sockglue.c 747 */ 748 749 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); 750 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 751 struct sk_buff *skb, int tlen, int offset); 752 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 753 struct ipcm_cookie *ipc, bool allow_ipv6); 754 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl); 755 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 756 unsigned int optlen); 757 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 758 int __user *optlen); 759 int ip_ra_control(struct sock *sk, unsigned char on, 760 void (*destructor)(struct sock *)); 761 762 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 763 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 764 u32 info, u8 *payload); 765 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 766 u32 info); 767 768 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 769 { 770 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 771 } 772 773 bool icmp_global_allow(void); 774 extern int sysctl_icmp_msgs_per_sec; 775 extern int sysctl_icmp_msgs_burst; 776 777 #ifdef CONFIG_PROC_FS 778 int ip_misc_proc_init(void); 779 #endif 780 781 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 782 struct netlink_ext_ack *extack); 783 784 static inline bool inetdev_valid_mtu(unsigned int mtu) 785 { 786 return likely(mtu >= IPV4_MIN_MTU); 787 } 788 789 void ip_sock_set_freebind(struct sock *sk); 790 int ip_sock_set_mtu_discover(struct sock *sk, int val); 791 void ip_sock_set_pktinfo(struct sock *sk); 792 void ip_sock_set_recverr(struct sock *sk); 793 void ip_sock_set_tos(struct sock *sk, int val); 794 795 #endif /* _IP_H */ 796