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 #include <net/inet_dscp.h> 37 38 #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */ 39 #define IPV4_MIN_MTU 68 /* RFC 791 */ 40 41 extern unsigned int sysctl_fib_sync_mem; 42 extern unsigned int sysctl_fib_sync_mem_min; 43 extern unsigned int sysctl_fib_sync_mem_max; 44 45 struct sock; 46 47 struct inet_skb_parm { 48 int iif; 49 struct ip_options opt; /* Compiled IP options */ 50 u16 flags; 51 52 #define IPSKB_FORWARDED BIT(0) 53 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1) 54 #define IPSKB_XFRM_TRANSFORMED BIT(2) 55 #define IPSKB_FRAG_COMPLETE BIT(3) 56 #define IPSKB_REROUTED BIT(4) 57 #define IPSKB_DOREDIRECT BIT(5) 58 #define IPSKB_FRAG_PMTU BIT(6) 59 #define IPSKB_L3SLAVE BIT(7) 60 #define IPSKB_NOPOLICY BIT(8) 61 #define IPSKB_MULTIPATH BIT(9) 62 63 u16 frag_max_size; 64 }; 65 66 static inline bool ipv4_l3mdev_skb(u16 flags) 67 { 68 return !!(flags & IPSKB_L3SLAVE); 69 } 70 71 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 72 { 73 return ip_hdr(skb)->ihl * 4; 74 } 75 76 struct ipcm_cookie { 77 struct sockcm_cookie sockc; 78 __be32 addr; 79 int oif; 80 struct ip_options_rcu *opt; 81 __u8 protocol; 82 __u8 ttl; 83 __s16 tos; 84 __u16 gso_size; 85 }; 86 87 static inline void ipcm_init(struct ipcm_cookie *ipcm) 88 { 89 *ipcm = (struct ipcm_cookie) { .tos = -1 }; 90 } 91 92 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm, 93 const struct inet_sock *inet) 94 { 95 *ipcm = (struct ipcm_cookie) { 96 .tos = READ_ONCE(inet->tos), 97 }; 98 99 sockcm_init(&ipcm->sockc, &inet->sk); 100 101 ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if); 102 ipcm->addr = inet->inet_saddr; 103 ipcm->protocol = inet->inet_num; 104 } 105 106 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 107 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb)) 108 109 /* return enslaved device index if relevant */ 110 static inline int inet_sdif(const struct sk_buff *skb) 111 { 112 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 113 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 114 return IPCB(skb)->iif; 115 #endif 116 return 0; 117 } 118 119 /* Special input handler for packets caught by router alert option. 120 They are selected only by protocol field, and then processed likely 121 local ones; but only if someone wants them! Otherwise, router 122 not running rsvpd will kill RSVP. 123 124 It is user level problem, what it will make with them. 125 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)), 126 but receiver should be enough clever f.e. to forward mtrace requests, 127 sent to multicast group to reach destination designated router. 128 */ 129 130 struct ip_ra_chain { 131 struct ip_ra_chain __rcu *next; 132 struct sock *sk; 133 union { 134 void (*destructor)(struct sock *); 135 struct sock *saved_sk; 136 }; 137 struct rcu_head rcu; 138 }; 139 140 /* IP flags. */ 141 #define IP_CE 0x8000 /* Flag: "Congestion" */ 142 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 143 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 144 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 145 146 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 147 148 struct msghdr; 149 struct net_device; 150 struct packet_type; 151 struct rtable; 152 struct sockaddr; 153 154 int igmp_mc_init(void); 155 156 /* 157 * Functions provided by ip.c 158 */ 159 160 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, 161 __be32 saddr, __be32 daddr, 162 struct ip_options_rcu *opt, u8 tos); 163 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 164 struct net_device *orig_dev); 165 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 166 struct net_device *orig_dev); 167 int ip_local_deliver(struct sk_buff *skb); 168 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto); 169 int ip_mr_input(struct sk_buff *skb); 170 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); 171 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); 172 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 173 int (*output)(struct net *, struct sock *, struct sk_buff *)); 174 175 struct ip_fraglist_iter { 176 struct sk_buff *frag; 177 struct iphdr *iph; 178 int offset; 179 unsigned int hlen; 180 }; 181 182 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, 183 unsigned int hlen, struct ip_fraglist_iter *iter); 184 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); 185 186 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) 187 { 188 struct sk_buff *skb = iter->frag; 189 190 iter->frag = skb->next; 191 skb_mark_not_on_list(skb); 192 193 return skb; 194 } 195 196 struct ip_frag_state { 197 bool DF; 198 unsigned int hlen; 199 unsigned int ll_rs; 200 unsigned int mtu; 201 unsigned int left; 202 int offset; 203 int ptr; 204 __be16 not_last_frag; 205 }; 206 207 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs, 208 unsigned int mtu, bool DF, struct ip_frag_state *state); 209 struct sk_buff *ip_frag_next(struct sk_buff *skb, 210 struct ip_frag_state *state); 211 212 void ip_send_check(struct iphdr *ip); 213 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 214 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 215 216 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 217 __u8 tos); 218 void ip_init(void); 219 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 220 int getfrag(void *from, char *to, int offset, int len, 221 int odd, struct sk_buff *skb), 222 void *from, int len, int protolen, 223 struct ipcm_cookie *ipc, 224 struct rtable **rt, 225 unsigned int flags); 226 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 227 struct sk_buff *skb); 228 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 229 struct sk_buff_head *queue, 230 struct inet_cork *cork); 231 int ip_send_skb(struct net *net, struct sk_buff *skb); 232 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 233 void ip_flush_pending_frames(struct sock *sk); 234 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 235 int getfrag(void *from, char *to, int offset, 236 int len, int odd, struct sk_buff *skb), 237 void *from, int length, int transhdrlen, 238 struct ipcm_cookie *ipc, struct rtable **rtp, 239 struct inet_cork *cork, unsigned int flags); 240 241 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 242 243 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 244 { 245 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 246 } 247 248 /* Get the route scope that should be used when sending a packet. */ 249 static inline u8 ip_sendmsg_scope(const struct inet_sock *inet, 250 const struct ipcm_cookie *ipc, 251 const struct msghdr *msg) 252 { 253 if (sock_flag(&inet->sk, SOCK_LOCALROUTE) || 254 msg->msg_flags & MSG_DONTROUTE || 255 (ipc->opt && ipc->opt->opt.is_strictroute)) 256 return RT_SCOPE_LINK; 257 258 return RT_SCOPE_UNIVERSE; 259 } 260 261 /* datagram.c */ 262 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 263 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 264 265 void ip4_datagram_release_cb(struct sock *sk); 266 267 struct ip_reply_arg { 268 struct kvec iov[1]; 269 int flags; 270 __wsum csum; 271 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 272 /* -1 if not needed */ 273 int bound_dev_if; 274 u8 tos; 275 kuid_t uid; 276 }; 277 278 #define IP_REPLY_ARG_NOSRCCHECK 1 279 280 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 281 { 282 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 283 } 284 285 void ip_send_unicast_reply(struct sock *sk, const struct sock *orig_sk, 286 struct sk_buff *skb, 287 const struct ip_options *sopt, 288 __be32 daddr, __be32 saddr, 289 const struct ip_reply_arg *arg, 290 unsigned int len, u64 transmit_time, u32 txhash); 291 292 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 293 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) 294 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 295 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 296 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 297 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 298 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 299 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) 300 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 301 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 302 303 static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt) 304 { 305 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt); 306 } 307 308 unsigned long snmp_fold_field(void __percpu *mib, int offt); 309 #if BITS_PER_LONG==32 310 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 311 size_t syncp_offset); 312 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); 313 #else 314 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 315 size_t syncp_offset) 316 { 317 return snmp_get_cpu_field(mib, cpu, offct); 318 319 } 320 321 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) 322 { 323 return snmp_fold_field(mib, offt); 324 } 325 #endif 326 327 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \ 328 { \ 329 int i, c; \ 330 for_each_possible_cpu(c) { \ 331 for (i = 0; stats_list[i].name; i++) \ 332 buff64[i] += snmp_get_cpu_field64( \ 333 mib_statistic, \ 334 c, stats_list[i].entry, \ 335 offset); \ 336 } \ 337 } 338 339 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \ 340 { \ 341 int i, c; \ 342 for_each_possible_cpu(c) { \ 343 for (i = 0; stats_list[i].name; i++) \ 344 buff[i] += snmp_get_cpu_field( \ 345 mib_statistic, \ 346 c, stats_list[i].entry); \ 347 } \ 348 } 349 350 static inline void inet_get_local_port_range(const struct net *net, int *low, int *high) 351 { 352 u32 range = READ_ONCE(net->ipv4.ip_local_ports.range); 353 354 *low = range & 0xffff; 355 *high = range >> 16; 356 } 357 bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high); 358 359 #ifdef CONFIG_SYSCTL 360 static inline bool inet_is_local_reserved_port(const struct net *net, unsigned short port) 361 { 362 if (!net->ipv4.sysctl_local_reserved_ports) 363 return false; 364 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 365 } 366 367 static inline bool sysctl_dev_name_is_allowed(const char *name) 368 { 369 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 370 } 371 372 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 373 { 374 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock); 375 } 376 377 #else 378 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 379 { 380 return false; 381 } 382 383 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 384 { 385 return port < PROT_SOCK; 386 } 387 #endif 388 389 __be32 inet_current_timestamp(void); 390 391 /* From inetpeer.c */ 392 extern int inet_peer_threshold; 393 extern int inet_peer_minttl; 394 extern int inet_peer_maxttl; 395 396 void ipfrag_init(void); 397 398 void ip_static_sysctl_init(void); 399 400 #define IP4_REPLY_MARK(net, mark) \ 401 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0) 402 403 static inline bool ip_is_fragment(const struct iphdr *iph) 404 { 405 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 406 } 407 408 #ifdef CONFIG_INET 409 #include <net/dst.h> 410 411 /* The function in 2.2 was invalid, producing wrong result for 412 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 413 static inline 414 int ip_decrease_ttl(struct iphdr *iph) 415 { 416 u32 check = (__force u32)iph->check; 417 check += (__force u32)htons(0x0100); 418 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 419 return --iph->ttl; 420 } 421 422 static inline dscp_t ip4h_dscp(const struct iphdr *ip4h) 423 { 424 return inet_dsfield_to_dscp(ip4h->tos); 425 } 426 427 static inline int ip_mtu_locked(const struct dst_entry *dst) 428 { 429 const struct rtable *rt = dst_rtable(dst); 430 431 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 432 } 433 434 static inline 435 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 436 { 437 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 438 439 return pmtudisc == IP_PMTUDISC_DO || 440 (pmtudisc == IP_PMTUDISC_WANT && 441 !ip_mtu_locked(dst)); 442 } 443 444 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 445 { 446 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 447 448 return pmtudisc != IP_PMTUDISC_INTERFACE && 449 pmtudisc != IP_PMTUDISC_OMIT; 450 } 451 452 static inline bool ip_sk_use_pmtu(const struct sock *sk) 453 { 454 return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE; 455 } 456 457 static inline bool ip_sk_ignore_df(const struct sock *sk) 458 { 459 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 460 461 return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT; 462 } 463 464 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 465 bool forwarding) 466 { 467 const struct rtable *rt = dst_rtable(dst); 468 unsigned int mtu, res; 469 struct net *net; 470 471 rcu_read_lock(); 472 473 net = dev_net_rcu(dst->dev); 474 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || 475 ip_mtu_locked(dst) || 476 !forwarding) { 477 mtu = rt->rt_pmtu; 478 if (mtu && time_before(jiffies, rt->dst.expires)) 479 goto out; 480 } 481 482 /* 'forwarding = true' case should always honour route mtu */ 483 mtu = dst_metric_raw(dst, RTAX_MTU); 484 if (mtu) 485 goto out; 486 487 mtu = READ_ONCE(dst->dev->mtu); 488 489 if (unlikely(ip_mtu_locked(dst))) { 490 if (rt->rt_uses_gateway && mtu > 576) 491 mtu = 576; 492 } 493 494 out: 495 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 496 497 res = mtu - lwtunnel_headroom(dst->lwtstate, mtu); 498 499 rcu_read_unlock(); 500 501 return res; 502 } 503 504 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 505 const struct sk_buff *skb) 506 { 507 unsigned int mtu; 508 509 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 510 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 511 512 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); 513 } 514 515 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); 516 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 517 } 518 519 struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len, 520 struct netlink_ext_ack *extack); 521 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 522 { 523 if (fib_metrics != &dst_default_metrics && 524 refcount_dec_and_test(&fib_metrics->refcnt)) 525 kfree(fib_metrics); 526 } 527 528 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 529 static inline 530 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 531 { 532 dst_init_metrics(dst, fib_metrics->metrics, true); 533 534 if (fib_metrics != &dst_default_metrics) { 535 dst->_metrics |= DST_METRICS_REFCOUNTED; 536 refcount_inc(&fib_metrics->refcnt); 537 } 538 } 539 540 static inline 541 void ip_dst_metrics_put(struct dst_entry *dst) 542 { 543 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 544 545 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 546 kfree(p); 547 } 548 549 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); 550 551 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, 552 struct sock *sk, int segs) 553 { 554 struct iphdr *iph = ip_hdr(skb); 555 556 /* We had many attacks based on IPID, use the private 557 * generator as much as we can. 558 */ 559 if (sk && inet_sk(sk)->inet_daddr) { 560 int val; 561 562 /* avoid atomic operations for TCP, 563 * as we hold socket lock at this point. 564 */ 565 if (sk_is_tcp(sk)) { 566 sock_owned_by_me(sk); 567 val = atomic_read(&inet_sk(sk)->inet_id); 568 atomic_set(&inet_sk(sk)->inet_id, val + segs); 569 } else { 570 val = atomic_add_return(segs, &inet_sk(sk)->inet_id); 571 } 572 iph->id = htons(val); 573 return; 574 } 575 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 576 iph->id = 0; 577 } else { 578 /* Unfortunately we need the big hammer to get a suitable IPID */ 579 __ip_select_ident(net, iph, segs); 580 } 581 } 582 583 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 584 struct sock *sk) 585 { 586 ip_select_ident_segs(net, skb, sk, 1); 587 } 588 589 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 590 { 591 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 592 skb->len, proto, 0); 593 } 594 595 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 596 * Equivalent to : flow->v4addrs.src = iph->saddr; 597 * flow->v4addrs.dst = iph->daddr; 598 */ 599 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 600 const struct iphdr *iph) 601 { 602 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 603 offsetof(typeof(flow->addrs), v4addrs.src) + 604 sizeof(flow->addrs.v4addrs.src)); 605 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs)); 606 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 607 } 608 609 /* 610 * Map a multicast IP onto multicast MAC for type ethernet. 611 */ 612 613 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 614 { 615 __u32 addr=ntohl(naddr); 616 buf[0]=0x01; 617 buf[1]=0x00; 618 buf[2]=0x5e; 619 buf[5]=addr&0xFF; 620 addr>>=8; 621 buf[4]=addr&0xFF; 622 addr>>=8; 623 buf[3]=addr&0x7F; 624 } 625 626 /* 627 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 628 * Leave P_Key as 0 to be filled in by driver. 629 */ 630 631 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 632 { 633 __u32 addr; 634 unsigned char scope = broadcast[5] & 0xF; 635 636 buf[0] = 0; /* Reserved */ 637 buf[1] = 0xff; /* Multicast QPN */ 638 buf[2] = 0xff; 639 buf[3] = 0xff; 640 addr = ntohl(naddr); 641 buf[4] = 0xff; 642 buf[5] = 0x10 | scope; /* scope from broadcast address */ 643 buf[6] = 0x40; /* IPv4 signature */ 644 buf[7] = 0x1b; 645 buf[8] = broadcast[8]; /* P_Key */ 646 buf[9] = broadcast[9]; 647 buf[10] = 0; 648 buf[11] = 0; 649 buf[12] = 0; 650 buf[13] = 0; 651 buf[14] = 0; 652 buf[15] = 0; 653 buf[19] = addr & 0xff; 654 addr >>= 8; 655 buf[18] = addr & 0xff; 656 addr >>= 8; 657 buf[17] = addr & 0xff; 658 addr >>= 8; 659 buf[16] = addr & 0x0f; 660 } 661 662 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 663 { 664 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 665 memcpy(buf, broadcast, 4); 666 else 667 memcpy(buf, &naddr, sizeof(naddr)); 668 } 669 670 #if IS_MODULE(CONFIG_IPV6) 671 #define EXPORT_IPV6_MOD(X) EXPORT_SYMBOL(X) 672 #define EXPORT_IPV6_MOD_GPL(X) EXPORT_SYMBOL_GPL(X) 673 #else 674 #define EXPORT_IPV6_MOD(X) 675 #define EXPORT_IPV6_MOD_GPL(X) 676 #endif 677 678 #if IS_ENABLED(CONFIG_IPV6) 679 #include <linux/ipv6.h> 680 #endif 681 682 static __inline__ void inet_reset_saddr(struct sock *sk) 683 { 684 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 685 #if IS_ENABLED(CONFIG_IPV6) 686 if (sk->sk_family == PF_INET6) { 687 struct ipv6_pinfo *np = inet6_sk(sk); 688 689 memset(&np->saddr, 0, sizeof(np->saddr)); 690 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 691 } 692 #endif 693 } 694 695 #endif 696 697 static inline unsigned int ipv4_addr_hash(__be32 ip) 698 { 699 return (__force unsigned int) ip; 700 } 701 702 static inline u32 __ipv4_addr_hash(const __be32 ip, const u32 initval) 703 { 704 return jhash_1word((__force u32)ip, initval); 705 } 706 707 static inline u32 ipv4_portaddr_hash(const struct net *net, 708 __be32 saddr, 709 unsigned int port) 710 { 711 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 712 } 713 714 bool ip_call_ra_chain(struct sk_buff *skb); 715 716 /* 717 * Functions provided by ip_fragment.c 718 */ 719 720 enum ip_defrag_users { 721 IP_DEFRAG_LOCAL_DELIVER, 722 IP_DEFRAG_CALL_RA_CHAIN, 723 IP_DEFRAG_CONNTRACK_IN, 724 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 725 IP_DEFRAG_CONNTRACK_OUT, 726 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 727 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 728 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 729 IP_DEFRAG_VS_IN, 730 IP_DEFRAG_VS_OUT, 731 IP_DEFRAG_VS_FWD, 732 IP_DEFRAG_AF_PACKET, 733 IP_DEFRAG_MACVLAN, 734 }; 735 736 /* Return true if the value of 'user' is between 'lower_bond' 737 * and 'upper_bond' inclusively. 738 */ 739 static inline bool ip_defrag_user_in_between(u32 user, 740 enum ip_defrag_users lower_bond, 741 enum ip_defrag_users upper_bond) 742 { 743 return user >= lower_bond && user <= upper_bond; 744 } 745 746 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 747 #ifdef CONFIG_INET 748 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 749 #else 750 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 751 { 752 return skb; 753 } 754 #endif 755 756 /* 757 * Functions provided by ip_forward.c 758 */ 759 760 int ip_forward(struct sk_buff *skb); 761 762 /* 763 * Functions provided by ip_options.c 764 */ 765 766 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 767 __be32 daddr, struct rtable *rt); 768 769 int __ip_options_echo(struct net *net, struct ip_options *dopt, 770 struct sk_buff *skb, const struct ip_options *sopt); 771 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 772 struct sk_buff *skb) 773 { 774 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 775 } 776 777 void ip_options_fragment(struct sk_buff *skb); 778 int __ip_options_compile(struct net *net, struct ip_options *opt, 779 struct sk_buff *skb, __be32 *info); 780 int ip_options_compile(struct net *net, struct ip_options *opt, 781 struct sk_buff *skb); 782 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 783 sockptr_t data, int optlen); 784 void ip_options_undo(struct ip_options *opt); 785 void ip_forward_options(struct sk_buff *skb); 786 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 787 788 /* 789 * Functions provided by ip_sockglue.c 790 */ 791 792 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst); 793 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 794 struct sk_buff *skb, int tlen, int offset); 795 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 796 struct ipcm_cookie *ipc, bool allow_ipv6); 797 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl); 798 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 799 unsigned int optlen); 800 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 801 unsigned int optlen); 802 int do_ip_getsockopt(struct sock *sk, int level, int optname, 803 sockptr_t optval, sockptr_t optlen); 804 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 805 int __user *optlen); 806 int ip_ra_control(struct sock *sk, unsigned char on, 807 void (*destructor)(struct sock *)); 808 809 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 810 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 811 u32 info, u8 *payload); 812 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 813 u32 info); 814 815 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 816 { 817 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 818 } 819 820 bool icmp_global_allow(struct net *net); 821 void icmp_global_consume(struct net *net); 822 823 #ifdef CONFIG_PROC_FS 824 int ip_misc_proc_init(void); 825 #endif 826 827 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 828 struct netlink_ext_ack *extack); 829 830 static inline bool inetdev_valid_mtu(unsigned int mtu) 831 { 832 return likely(mtu >= IPV4_MIN_MTU); 833 } 834 835 void ip_sock_set_freebind(struct sock *sk); 836 int ip_sock_set_mtu_discover(struct sock *sk, int val); 837 void ip_sock_set_pktinfo(struct sock *sk); 838 void ip_sock_set_recverr(struct sock *sk); 839 void ip_sock_set_tos(struct sock *sk, int val); 840 void __ip_sock_set_tos(struct sock *sk, int val); 841 842 #endif /* _IP_H */ 843