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 #define IPSKB_NOPOLICY BIT(8) 60 61 u16 frag_max_size; 62 }; 63 64 static inline bool ipv4_l3mdev_skb(u16 flags) 65 { 66 return !!(flags & IPSKB_L3SLAVE); 67 } 68 69 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 70 { 71 return ip_hdr(skb)->ihl * 4; 72 } 73 74 struct ipcm_cookie { 75 struct sockcm_cookie sockc; 76 __be32 addr; 77 int oif; 78 struct ip_options_rcu *opt; 79 __u8 ttl; 80 __s16 tos; 81 char priority; 82 __u16 gso_size; 83 }; 84 85 static inline void ipcm_init(struct ipcm_cookie *ipcm) 86 { 87 *ipcm = (struct ipcm_cookie) { .tos = -1 }; 88 } 89 90 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm, 91 const struct inet_sock *inet) 92 { 93 ipcm_init(ipcm); 94 95 ipcm->sockc.mark = inet->sk.sk_mark; 96 ipcm->sockc.tsflags = inet->sk.sk_tsflags; 97 ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if); 98 ipcm->addr = inet->inet_saddr; 99 } 100 101 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 102 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb)) 103 104 /* return enslaved device index if relevant */ 105 static inline int inet_sdif(const struct sk_buff *skb) 106 { 107 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 108 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 109 return IPCB(skb)->iif; 110 #endif 111 return 0; 112 } 113 114 /* Special input handler for packets caught by router alert option. 115 They are selected only by protocol field, and then processed likely 116 local ones; but only if someone wants them! Otherwise, router 117 not running rsvpd will kill RSVP. 118 119 It is user level problem, what it will make with them. 120 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)), 121 but receiver should be enough clever f.e. to forward mtrace requests, 122 sent to multicast group to reach destination designated router. 123 */ 124 125 struct ip_ra_chain { 126 struct ip_ra_chain __rcu *next; 127 struct sock *sk; 128 union { 129 void (*destructor)(struct sock *); 130 struct sock *saved_sk; 131 }; 132 struct rcu_head rcu; 133 }; 134 135 /* IP flags. */ 136 #define IP_CE 0x8000 /* Flag: "Congestion" */ 137 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 138 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 139 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 140 141 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 142 143 struct msghdr; 144 struct net_device; 145 struct packet_type; 146 struct rtable; 147 struct sockaddr; 148 149 int igmp_mc_init(void); 150 151 /* 152 * Functions provided by ip.c 153 */ 154 155 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, 156 __be32 saddr, __be32 daddr, 157 struct ip_options_rcu *opt, u8 tos); 158 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 159 struct net_device *orig_dev); 160 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 161 struct net_device *orig_dev); 162 int ip_local_deliver(struct sk_buff *skb); 163 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto); 164 int ip_mr_input(struct sk_buff *skb); 165 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); 166 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); 167 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 168 int (*output)(struct net *, struct sock *, struct sk_buff *)); 169 170 struct ip_fraglist_iter { 171 struct sk_buff *frag; 172 struct iphdr *iph; 173 int offset; 174 unsigned int hlen; 175 }; 176 177 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, 178 unsigned int hlen, struct ip_fraglist_iter *iter); 179 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); 180 181 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) 182 { 183 struct sk_buff *skb = iter->frag; 184 185 iter->frag = skb->next; 186 skb_mark_not_on_list(skb); 187 188 return skb; 189 } 190 191 struct ip_frag_state { 192 bool DF; 193 unsigned int hlen; 194 unsigned int ll_rs; 195 unsigned int mtu; 196 unsigned int left; 197 int offset; 198 int ptr; 199 __be16 not_last_frag; 200 }; 201 202 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs, 203 unsigned int mtu, bool DF, struct ip_frag_state *state); 204 struct sk_buff *ip_frag_next(struct sk_buff *skb, 205 struct ip_frag_state *state); 206 207 void ip_send_check(struct iphdr *ip); 208 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 209 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 210 211 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 212 __u8 tos); 213 void ip_init(void); 214 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 215 int getfrag(void *from, char *to, int offset, int len, 216 int odd, struct sk_buff *skb), 217 void *from, int len, int protolen, 218 struct ipcm_cookie *ipc, 219 struct rtable **rt, 220 unsigned int flags); 221 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 222 struct sk_buff *skb); 223 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 224 int offset, size_t size, int flags); 225 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 226 struct sk_buff_head *queue, 227 struct inet_cork *cork); 228 int ip_send_skb(struct net *net, struct sk_buff *skb); 229 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 230 void ip_flush_pending_frames(struct sock *sk); 231 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 232 int getfrag(void *from, char *to, int offset, 233 int len, int odd, struct sk_buff *skb), 234 void *from, int length, int transhdrlen, 235 struct ipcm_cookie *ipc, struct rtable **rtp, 236 struct inet_cork *cork, unsigned int flags); 237 238 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 239 240 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 241 { 242 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 243 } 244 245 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet) 246 { 247 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos); 248 } 249 250 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk) 251 { 252 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk); 253 } 254 255 /* datagram.c */ 256 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 257 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 258 259 void ip4_datagram_release_cb(struct sock *sk); 260 261 struct ip_reply_arg { 262 struct kvec iov[1]; 263 int flags; 264 __wsum csum; 265 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 266 /* -1 if not needed */ 267 int bound_dev_if; 268 u8 tos; 269 kuid_t uid; 270 }; 271 272 #define IP_REPLY_ARG_NOSRCCHECK 1 273 274 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 275 { 276 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 277 } 278 279 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, 280 const struct ip_options *sopt, 281 __be32 daddr, __be32 saddr, 282 const struct ip_reply_arg *arg, 283 unsigned int len, u64 transmit_time); 284 285 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 286 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) 287 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 288 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_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 __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 291 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 292 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) 293 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 294 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 295 296 static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt) 297 { 298 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt); 299 } 300 301 unsigned long snmp_fold_field(void __percpu *mib, int offt); 302 #if BITS_PER_LONG==32 303 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 304 size_t syncp_offset); 305 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); 306 #else 307 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 308 size_t syncp_offset) 309 { 310 return snmp_get_cpu_field(mib, cpu, offct); 311 312 } 313 314 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) 315 { 316 return snmp_fold_field(mib, offt); 317 } 318 #endif 319 320 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \ 321 { \ 322 int i, c; \ 323 for_each_possible_cpu(c) { \ 324 for (i = 0; stats_list[i].name; i++) \ 325 buff64[i] += snmp_get_cpu_field64( \ 326 mib_statistic, \ 327 c, stats_list[i].entry, \ 328 offset); \ 329 } \ 330 } 331 332 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \ 333 { \ 334 int i, c; \ 335 for_each_possible_cpu(c) { \ 336 for (i = 0; stats_list[i].name; i++) \ 337 buff[i] += snmp_get_cpu_field( \ 338 mib_statistic, \ 339 c, stats_list[i].entry); \ 340 } \ 341 } 342 343 void inet_get_local_port_range(struct net *net, int *low, int *high); 344 345 #ifdef CONFIG_SYSCTL 346 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 347 { 348 if (!net->ipv4.sysctl_local_reserved_ports) 349 return false; 350 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 351 } 352 353 static inline bool sysctl_dev_name_is_allowed(const char *name) 354 { 355 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 356 } 357 358 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 359 { 360 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock); 361 } 362 363 #else 364 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 365 { 366 return false; 367 } 368 369 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 370 { 371 return port < PROT_SOCK; 372 } 373 #endif 374 375 __be32 inet_current_timestamp(void); 376 377 /* From inetpeer.c */ 378 extern int inet_peer_threshold; 379 extern int inet_peer_minttl; 380 extern int inet_peer_maxttl; 381 382 void ipfrag_init(void); 383 384 void ip_static_sysctl_init(void); 385 386 #define IP4_REPLY_MARK(net, mark) \ 387 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0) 388 389 static inline bool ip_is_fragment(const struct iphdr *iph) 390 { 391 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 392 } 393 394 #ifdef CONFIG_INET 395 #include <net/dst.h> 396 397 /* The function in 2.2 was invalid, producing wrong result for 398 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 399 static inline 400 int ip_decrease_ttl(struct iphdr *iph) 401 { 402 u32 check = (__force u32)iph->check; 403 check += (__force u32)htons(0x0100); 404 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 405 return --iph->ttl; 406 } 407 408 static inline int ip_mtu_locked(const struct dst_entry *dst) 409 { 410 const struct rtable *rt = (const struct rtable *)dst; 411 412 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 413 } 414 415 static inline 416 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 417 { 418 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 419 420 return pmtudisc == IP_PMTUDISC_DO || 421 (pmtudisc == IP_PMTUDISC_WANT && 422 !ip_mtu_locked(dst)); 423 } 424 425 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 426 { 427 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE && 428 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT; 429 } 430 431 static inline bool ip_sk_use_pmtu(const struct sock *sk) 432 { 433 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE; 434 } 435 436 static inline bool ip_sk_ignore_df(const struct sock *sk) 437 { 438 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO || 439 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT; 440 } 441 442 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 443 bool forwarding) 444 { 445 const struct rtable *rt = container_of(dst, struct rtable, dst); 446 struct net *net = dev_net(dst->dev); 447 unsigned int mtu; 448 449 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || 450 ip_mtu_locked(dst) || 451 !forwarding) { 452 mtu = rt->rt_pmtu; 453 if (mtu && time_before(jiffies, rt->dst.expires)) 454 goto out; 455 } 456 457 /* 'forwarding = true' case should always honour route mtu */ 458 mtu = dst_metric_raw(dst, RTAX_MTU); 459 if (mtu) 460 goto out; 461 462 mtu = READ_ONCE(dst->dev->mtu); 463 464 if (unlikely(ip_mtu_locked(dst))) { 465 if (rt->rt_uses_gateway && mtu > 576) 466 mtu = 576; 467 } 468 469 out: 470 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 471 472 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 473 } 474 475 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 476 const struct sk_buff *skb) 477 { 478 unsigned int mtu; 479 480 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 481 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 482 483 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); 484 } 485 486 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); 487 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 488 } 489 490 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx, 491 int fc_mx_len, 492 struct netlink_ext_ack *extack); 493 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 494 { 495 if (fib_metrics != &dst_default_metrics && 496 refcount_dec_and_test(&fib_metrics->refcnt)) 497 kfree(fib_metrics); 498 } 499 500 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 501 static inline 502 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 503 { 504 dst_init_metrics(dst, fib_metrics->metrics, true); 505 506 if (fib_metrics != &dst_default_metrics) { 507 dst->_metrics |= DST_METRICS_REFCOUNTED; 508 refcount_inc(&fib_metrics->refcnt); 509 } 510 } 511 512 static inline 513 void ip_dst_metrics_put(struct dst_entry *dst) 514 { 515 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 516 517 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 518 kfree(p); 519 } 520 521 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 /* We had many attacks based on IPID, use the private 529 * generator as much as we can. 530 */ 531 if (sk && inet_sk(sk)->inet_daddr) { 532 iph->id = htons(inet_sk(sk)->inet_id); 533 inet_sk(sk)->inet_id += segs; 534 return; 535 } 536 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 537 iph->id = 0; 538 } else { 539 /* Unfortunately we need the big hammer to get a suitable IPID */ 540 __ip_select_ident(net, iph, segs); 541 } 542 } 543 544 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 545 struct sock *sk) 546 { 547 ip_select_ident_segs(net, skb, sk, 1); 548 } 549 550 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 551 { 552 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 553 skb->len, proto, 0); 554 } 555 556 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 557 * Equivalent to : flow->v4addrs.src = iph->saddr; 558 * flow->v4addrs.dst = iph->daddr; 559 */ 560 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 561 const struct iphdr *iph) 562 { 563 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 564 offsetof(typeof(flow->addrs), v4addrs.src) + 565 sizeof(flow->addrs.v4addrs.src)); 566 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs)); 567 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 568 } 569 570 /* 571 * Map a multicast IP onto multicast MAC for type ethernet. 572 */ 573 574 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 575 { 576 __u32 addr=ntohl(naddr); 577 buf[0]=0x01; 578 buf[1]=0x00; 579 buf[2]=0x5e; 580 buf[5]=addr&0xFF; 581 addr>>=8; 582 buf[4]=addr&0xFF; 583 addr>>=8; 584 buf[3]=addr&0x7F; 585 } 586 587 /* 588 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 589 * Leave P_Key as 0 to be filled in by driver. 590 */ 591 592 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 593 { 594 __u32 addr; 595 unsigned char scope = broadcast[5] & 0xF; 596 597 buf[0] = 0; /* Reserved */ 598 buf[1] = 0xff; /* Multicast QPN */ 599 buf[2] = 0xff; 600 buf[3] = 0xff; 601 addr = ntohl(naddr); 602 buf[4] = 0xff; 603 buf[5] = 0x10 | scope; /* scope from broadcast address */ 604 buf[6] = 0x40; /* IPv4 signature */ 605 buf[7] = 0x1b; 606 buf[8] = broadcast[8]; /* P_Key */ 607 buf[9] = broadcast[9]; 608 buf[10] = 0; 609 buf[11] = 0; 610 buf[12] = 0; 611 buf[13] = 0; 612 buf[14] = 0; 613 buf[15] = 0; 614 buf[19] = addr & 0xff; 615 addr >>= 8; 616 buf[18] = addr & 0xff; 617 addr >>= 8; 618 buf[17] = addr & 0xff; 619 addr >>= 8; 620 buf[16] = addr & 0x0f; 621 } 622 623 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 624 { 625 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 626 memcpy(buf, broadcast, 4); 627 else 628 memcpy(buf, &naddr, sizeof(naddr)); 629 } 630 631 #if IS_ENABLED(CONFIG_IPV6) 632 #include <linux/ipv6.h> 633 #endif 634 635 static __inline__ void inet_reset_saddr(struct sock *sk) 636 { 637 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 638 #if IS_ENABLED(CONFIG_IPV6) 639 if (sk->sk_family == PF_INET6) { 640 struct ipv6_pinfo *np = inet6_sk(sk); 641 642 memset(&np->saddr, 0, sizeof(np->saddr)); 643 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 644 } 645 #endif 646 } 647 648 #endif 649 650 static inline unsigned int ipv4_addr_hash(__be32 ip) 651 { 652 return (__force unsigned int) ip; 653 } 654 655 static inline u32 ipv4_portaddr_hash(const struct net *net, 656 __be32 saddr, 657 unsigned int port) 658 { 659 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 660 } 661 662 bool ip_call_ra_chain(struct sk_buff *skb); 663 664 /* 665 * Functions provided by ip_fragment.c 666 */ 667 668 enum ip_defrag_users { 669 IP_DEFRAG_LOCAL_DELIVER, 670 IP_DEFRAG_CALL_RA_CHAIN, 671 IP_DEFRAG_CONNTRACK_IN, 672 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 673 IP_DEFRAG_CONNTRACK_OUT, 674 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 675 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 676 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 677 IP_DEFRAG_VS_IN, 678 IP_DEFRAG_VS_OUT, 679 IP_DEFRAG_VS_FWD, 680 IP_DEFRAG_AF_PACKET, 681 IP_DEFRAG_MACVLAN, 682 }; 683 684 /* Return true if the value of 'user' is between 'lower_bond' 685 * and 'upper_bond' inclusively. 686 */ 687 static inline bool ip_defrag_user_in_between(u32 user, 688 enum ip_defrag_users lower_bond, 689 enum ip_defrag_users upper_bond) 690 { 691 return user >= lower_bond && user <= upper_bond; 692 } 693 694 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 695 #ifdef CONFIG_INET 696 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 697 #else 698 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 699 { 700 return skb; 701 } 702 #endif 703 704 /* 705 * Functions provided by ip_forward.c 706 */ 707 708 int ip_forward(struct sk_buff *skb); 709 710 /* 711 * Functions provided by ip_options.c 712 */ 713 714 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 715 __be32 daddr, struct rtable *rt); 716 717 int __ip_options_echo(struct net *net, struct ip_options *dopt, 718 struct sk_buff *skb, const struct ip_options *sopt); 719 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 720 struct sk_buff *skb) 721 { 722 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 723 } 724 725 void ip_options_fragment(struct sk_buff *skb); 726 int __ip_options_compile(struct net *net, struct ip_options *opt, 727 struct sk_buff *skb, __be32 *info); 728 int ip_options_compile(struct net *net, struct ip_options *opt, 729 struct sk_buff *skb); 730 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 731 sockptr_t data, int optlen); 732 void ip_options_undo(struct ip_options *opt); 733 void ip_forward_options(struct sk_buff *skb); 734 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 735 736 /* 737 * Functions provided by ip_sockglue.c 738 */ 739 740 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb); 741 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 742 struct sk_buff *skb, int tlen, int offset); 743 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 744 struct ipcm_cookie *ipc, bool allow_ipv6); 745 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl); 746 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 747 unsigned int optlen); 748 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 749 int __user *optlen); 750 int ip_ra_control(struct sock *sk, unsigned char on, 751 void (*destructor)(struct sock *)); 752 753 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 754 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 755 u32 info, u8 *payload); 756 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 757 u32 info); 758 759 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 760 { 761 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 762 } 763 764 bool icmp_global_allow(void); 765 extern int sysctl_icmp_msgs_per_sec; 766 extern int sysctl_icmp_msgs_burst; 767 768 #ifdef CONFIG_PROC_FS 769 int ip_misc_proc_init(void); 770 #endif 771 772 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 773 struct netlink_ext_ack *extack); 774 775 static inline bool inetdev_valid_mtu(unsigned int mtu) 776 { 777 return likely(mtu >= IPV4_MIN_MTU); 778 } 779 780 void ip_sock_set_freebind(struct sock *sk); 781 int ip_sock_set_mtu_discover(struct sock *sk, int val); 782 void ip_sock_set_pktinfo(struct sock *sk); 783 void ip_sock_set_recverr(struct sock *sk); 784 void ip_sock_set_tos(struct sock *sk, int val); 785 void __ip_sock_set_tos(struct sock *sk, int val); 786 787 #endif /* _IP_H */ 788