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 #define IPSKB_MCROUTE BIT(10) 63 64 u16 frag_max_size; 65 }; 66 67 static inline bool ipv4_l3mdev_skb(u16 flags) 68 { 69 return !!(flags & IPSKB_L3SLAVE); 70 } 71 72 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 73 { 74 return ip_hdr(skb)->ihl * 4; 75 } 76 77 struct ipcm_cookie { 78 struct sockcm_cookie sockc; 79 __be32 addr; 80 int oif; 81 struct ip_options_rcu *opt; 82 __u8 protocol; 83 __u8 ttl; 84 __s16 tos; 85 __u16 gso_size; 86 }; 87 88 static inline void ipcm_init(struct ipcm_cookie *ipcm) 89 { 90 *ipcm = (struct ipcm_cookie) { .tos = -1 }; 91 } 92 93 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm, 94 const struct inet_sock *inet) 95 { 96 *ipcm = (struct ipcm_cookie) { 97 .tos = READ_ONCE(inet->tos), 98 }; 99 100 sockcm_init(&ipcm->sockc, &inet->sk); 101 102 ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if); 103 ipcm->addr = inet->inet_saddr; 104 ipcm->protocol = READ_ONCE(inet->inet_num); 105 } 106 107 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 108 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb)) 109 110 /* return enslaved device index if relevant */ 111 static inline int inet_sdif(const struct sk_buff *skb) 112 { 113 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 114 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) 115 return IPCB(skb)->iif; 116 #endif 117 return 0; 118 } 119 120 /* Special input handler for packets caught by router alert option. 121 They are selected only by protocol field, and then processed likely 122 local ones; but only if someone wants them! Otherwise, router 123 not running rsvpd will kill RSVP. 124 125 It is user level problem, what it will make with them. 126 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)), 127 but receiver should be enough clever f.e. to forward mtrace requests, 128 sent to multicast group to reach destination designated router. 129 */ 130 131 struct ip_ra_chain { 132 struct ip_ra_chain __rcu *next; 133 struct sock *sk; 134 union { 135 void (*destructor)(struct sock *); 136 struct sock *saved_sk; 137 }; 138 struct rcu_head rcu; 139 }; 140 141 /* IP flags. */ 142 #define IP_CE 0x8000 /* Flag: "Congestion" */ 143 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 144 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 145 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 146 147 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 148 149 struct msghdr; 150 struct net_device; 151 struct packet_type; 152 struct rtable; 153 struct sockaddr; 154 155 int igmp_mc_init(void); 156 157 /* 158 * Functions provided by ip.c 159 */ 160 161 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk, 162 __be32 saddr, __be32 daddr, 163 struct ip_options_rcu *opt, u8 tos); 164 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 165 struct net_device *orig_dev); 166 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 167 struct net_device *orig_dev); 168 int ip_local_deliver(struct sk_buff *skb); 169 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto); 170 int ip_mr_input(struct sk_buff *skb); 171 int ip_mr_output(struct net *net, struct sock *sk, struct sk_buff *skb); 172 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); 173 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); 174 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 175 int (*output)(struct net *, struct sock *, struct sk_buff *)); 176 177 struct ip_fraglist_iter { 178 struct sk_buff *frag; 179 struct iphdr *iph; 180 int offset; 181 unsigned int hlen; 182 }; 183 184 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, 185 unsigned int hlen, struct ip_fraglist_iter *iter); 186 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); 187 188 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) 189 { 190 struct sk_buff *skb = iter->frag; 191 192 iter->frag = skb->next; 193 skb_mark_not_on_list(skb); 194 195 return skb; 196 } 197 198 struct ip_frag_state { 199 bool DF; 200 unsigned int hlen; 201 unsigned int ll_rs; 202 unsigned int mtu; 203 unsigned int left; 204 int offset; 205 int ptr; 206 __be16 not_last_frag; 207 }; 208 209 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs, 210 unsigned int mtu, bool DF, struct ip_frag_state *state); 211 struct sk_buff *ip_frag_next(struct sk_buff *skb, 212 struct ip_frag_state *state); 213 214 void ip_send_check(struct iphdr *ip); 215 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 216 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 217 218 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 219 __u8 tos); 220 void ip_init(void); 221 int ip_append_data(struct sock *sk, struct flowi4 *fl4, 222 int getfrag(void *from, char *to, int offset, int len, 223 int odd, struct sk_buff *skb), 224 void *from, int len, int protolen, 225 struct ipcm_cookie *ipc, 226 struct rtable **rt, 227 unsigned int flags); 228 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 229 struct sk_buff *skb); 230 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 231 struct sk_buff_head *queue, 232 struct inet_cork *cork); 233 int ip_send_skb(struct net *net, struct sk_buff *skb); 234 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 235 void ip_flush_pending_frames(struct sock *sk); 236 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4, 237 int getfrag(void *from, char *to, int offset, 238 int len, int odd, struct sk_buff *skb), 239 void *from, int length, int transhdrlen, 240 struct ipcm_cookie *ipc, struct rtable **rtp, 241 struct inet_cork *cork, unsigned int flags); 242 243 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 244 245 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4) 246 { 247 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 248 } 249 250 /* Get the route scope that should be used when sending a packet. */ 251 static inline u8 ip_sendmsg_scope(const struct inet_sock *inet, 252 const struct ipcm_cookie *ipc, 253 const struct msghdr *msg) 254 { 255 if (sock_flag(&inet->sk, SOCK_LOCALROUTE) || 256 msg->msg_flags & MSG_DONTROUTE || 257 (ipc->opt && ipc->opt->opt.is_strictroute)) 258 return RT_SCOPE_LINK; 259 260 return RT_SCOPE_UNIVERSE; 261 } 262 263 /* datagram.c */ 264 int __ip4_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len); 265 int ip4_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len); 266 267 void ip4_datagram_release_cb(struct sock *sk); 268 269 struct ip_reply_arg { 270 struct kvec iov[1]; 271 int flags; 272 __wsum csum; 273 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 274 /* -1 if not needed */ 275 int bound_dev_if; 276 u8 tos; 277 kuid_t uid; 278 }; 279 280 #define IP_REPLY_ARG_NOSRCCHECK 1 281 282 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 283 { 284 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 285 } 286 287 void ip_send_unicast_reply(struct sock *sk, const struct sock *orig_sk, 288 struct sk_buff *skb, 289 const struct ip_options *sopt, 290 __be32 daddr, __be32 saddr, 291 const struct ip_reply_arg *arg, 292 unsigned int len, u64 transmit_time, u32 txhash); 293 294 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 295 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) 296 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 297 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 298 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 299 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 300 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 301 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) 302 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 303 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 304 305 static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt) 306 { 307 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt); 308 } 309 310 unsigned long snmp_fold_field(void __percpu *mib, int offt); 311 #if BITS_PER_LONG==32 312 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 313 size_t syncp_offset); 314 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); 315 #else 316 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 317 size_t syncp_offset) 318 { 319 return snmp_get_cpu_field(mib, cpu, offct); 320 321 } 322 323 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) 324 { 325 return snmp_fold_field(mib, offt); 326 } 327 #endif 328 329 #define snmp_get_cpu_field64_batch_cnt(buff64, stats_list, cnt, \ 330 mib_statistic, offset) \ 331 { \ 332 int i, c; \ 333 for_each_possible_cpu(c) { \ 334 for (i = 0; i < cnt; i++) \ 335 buff64[i] += snmp_get_cpu_field64( \ 336 mib_statistic, \ 337 c, stats_list[i].entry, \ 338 offset); \ 339 } \ 340 } 341 342 #define snmp_get_cpu_field_batch_cnt(buff, stats_list, cnt, mib_statistic) \ 343 { \ 344 int i, c; \ 345 for_each_possible_cpu(c) { \ 346 for (i = 0; i < cnt; i++) \ 347 buff[i] += snmp_get_cpu_field( \ 348 mib_statistic, \ 349 c, stats_list[i].entry); \ 350 } \ 351 } 352 353 static inline void inet_get_local_port_range(const struct net *net, int *low, int *high) 354 { 355 u32 range = READ_ONCE(net->ipv4.ip_local_ports.range); 356 357 *low = range & 0xffff; 358 *high = range >> 16; 359 } 360 bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high); 361 362 #ifdef CONFIG_SYSCTL 363 static inline bool inet_is_local_reserved_port(const struct net *net, unsigned short port) 364 { 365 if (!net->ipv4.sysctl_local_reserved_ports) 366 return false; 367 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 368 } 369 370 static inline bool sysctl_dev_name_is_allowed(const char *name) 371 { 372 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 373 } 374 375 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 376 { 377 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock); 378 } 379 380 #else 381 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 382 { 383 return false; 384 } 385 386 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 387 { 388 return port < PROT_SOCK; 389 } 390 #endif 391 392 __be32 inet_current_timestamp(void); 393 394 /* From inetpeer.c */ 395 extern int inet_peer_threshold; 396 extern int inet_peer_minttl; 397 extern int inet_peer_maxttl; 398 399 void ipfrag_init(void); 400 401 void ip_static_sysctl_init(void); 402 403 #define IP4_REPLY_MARK(net, mark) \ 404 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0) 405 406 static inline bool ip_is_fragment(const struct iphdr *iph) 407 { 408 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 409 } 410 411 #ifdef CONFIG_INET 412 #include <net/dst.h> 413 414 /* The function in 2.2 was invalid, producing wrong result for 415 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 416 static inline 417 int ip_decrease_ttl(struct iphdr *iph) 418 { 419 u32 check = (__force u32)iph->check; 420 check += (__force u32)htons(0x0100); 421 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 422 return --iph->ttl; 423 } 424 425 static inline dscp_t ip4h_dscp(const struct iphdr *ip4h) 426 { 427 return inet_dsfield_to_dscp(ip4h->tos); 428 } 429 430 static inline int ip_mtu_locked(const struct dst_entry *dst) 431 { 432 const struct rtable *rt = dst_rtable(dst); 433 434 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 435 } 436 437 static inline 438 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 439 { 440 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 441 442 return pmtudisc == IP_PMTUDISC_DO || 443 (pmtudisc == IP_PMTUDISC_WANT && 444 !ip_mtu_locked(dst)); 445 } 446 447 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 448 { 449 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 450 451 return pmtudisc != IP_PMTUDISC_INTERFACE && 452 pmtudisc != IP_PMTUDISC_OMIT; 453 } 454 455 static inline bool ip_sk_use_pmtu(const struct sock *sk) 456 { 457 return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE; 458 } 459 460 static inline bool ip_sk_ignore_df(const struct sock *sk) 461 { 462 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 463 464 return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT; 465 } 466 467 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 468 bool forwarding) 469 { 470 const struct rtable *rt = dst_rtable(dst); 471 const struct net_device *dev; 472 unsigned int mtu, res; 473 struct net *net; 474 475 rcu_read_lock(); 476 477 dev = dst_dev_rcu(dst); 478 net = dev_net_rcu(dev); 479 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || 480 ip_mtu_locked(dst) || 481 !forwarding) { 482 mtu = rt->rt_pmtu; 483 if (mtu && time_before(jiffies, READ_ONCE(rt->dst.expires))) 484 goto out; 485 } 486 487 /* 'forwarding = true' case should always honour route mtu */ 488 mtu = dst_metric_raw(dst, RTAX_MTU); 489 if (mtu) 490 goto out; 491 492 mtu = READ_ONCE(dev->mtu); 493 494 if (unlikely(ip_mtu_locked(dst))) { 495 if (rt->rt_uses_gateway && mtu > 576) 496 mtu = 576; 497 } 498 499 out: 500 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 501 502 res = mtu - lwtunnel_headroom(dst->lwtstate, mtu); 503 504 rcu_read_unlock(); 505 506 return res; 507 } 508 509 /* Configured/administrative MTU of a route, for advertising the TCP MSS. 510 * 511 * Unlike ip_dst_mtu_maybe_forward(), this deliberately ignores the 512 * ICMP-learned path MTU (rt->rt_pmtu). The advertised MSS bounds what the 513 * peer may send to us and must reflect our receive capability (the device or 514 * route-configured MTU), not a path MTU learned on the reverse (send) 515 * direction, which may not apply to the peer->us path and outlives the fnhe 516 * for the whole connection. See RFC 2923 section 2.3 and the comment above 517 * tcp_advertise_mss(). 518 */ 519 static inline unsigned int ip_dst_mtu_configured(const struct dst_entry *dst) 520 { 521 unsigned int mtu, res; 522 523 rcu_read_lock(); 524 mtu = dst_metric_raw(dst, RTAX_MTU); 525 if (!mtu) 526 mtu = READ_ONCE(dst_dev_rcu(dst)->mtu); 527 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 528 res = mtu - lwtunnel_headroom(dst->lwtstate, mtu); 529 rcu_read_unlock(); 530 531 return res; 532 } 533 534 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 535 const struct sk_buff *skb) 536 { 537 const struct dst_entry *dst = skb_dst(skb); 538 unsigned int mtu; 539 540 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 541 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 542 543 return ip_dst_mtu_maybe_forward(dst, forwarding); 544 } 545 546 mtu = min(READ_ONCE(dst_dev(dst)->mtu), IP_MAX_MTU); 547 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 548 } 549 550 struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len, 551 struct netlink_ext_ack *extack); 552 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 553 { 554 if (fib_metrics != &dst_default_metrics && 555 refcount_dec_and_test(&fib_metrics->refcnt)) 556 kfree(fib_metrics); 557 } 558 559 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 560 static inline 561 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 562 { 563 dst_init_metrics(dst, fib_metrics->metrics, true); 564 565 if (fib_metrics != &dst_default_metrics) { 566 dst->_metrics |= DST_METRICS_REFCOUNTED; 567 refcount_inc(&fib_metrics->refcnt); 568 } 569 } 570 571 static inline 572 void ip_dst_metrics_put(struct dst_entry *dst) 573 { 574 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 575 576 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 577 kfree(p); 578 } 579 580 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); 581 582 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, 583 struct sock *sk, int segs) 584 { 585 struct iphdr *iph = ip_hdr(skb); 586 587 /* We had many attacks based on IPID, use the private 588 * generator as much as we can. 589 */ 590 if (sk && inet_sk(sk)->inet_daddr) { 591 int val; 592 593 /* avoid atomic operations for TCP, 594 * as we hold socket lock at this point. 595 */ 596 if (sk_is_tcp(sk)) { 597 sock_owned_by_me(sk); 598 val = atomic_read(&inet_sk(sk)->inet_id); 599 atomic_set(&inet_sk(sk)->inet_id, val + segs); 600 } else { 601 val = atomic_add_return(segs, &inet_sk(sk)->inet_id); 602 } 603 iph->id = htons(val); 604 return; 605 } 606 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 607 iph->id = 0; 608 } else { 609 /* Unfortunately we need the big hammer to get a suitable IPID */ 610 __ip_select_ident(net, iph, segs); 611 } 612 } 613 614 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 615 struct sock *sk) 616 { 617 ip_select_ident_segs(net, skb, sk, 1); 618 } 619 620 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 621 { 622 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 623 skb->len, proto, 0); 624 } 625 626 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 627 * Equivalent to : flow->v4addrs.src = iph->saddr; 628 * flow->v4addrs.dst = iph->daddr; 629 */ 630 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 631 const struct iphdr *iph) 632 { 633 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 634 offsetof(typeof(flow->addrs), v4addrs.src) + 635 sizeof(flow->addrs.v4addrs.src)); 636 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs)); 637 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 638 } 639 640 /* 641 * Map a multicast IP onto multicast MAC for type ethernet. 642 */ 643 644 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 645 { 646 __u32 addr=ntohl(naddr); 647 buf[0]=0x01; 648 buf[1]=0x00; 649 buf[2]=0x5e; 650 buf[5]=addr&0xFF; 651 addr>>=8; 652 buf[4]=addr&0xFF; 653 addr>>=8; 654 buf[3]=addr&0x7F; 655 } 656 657 /* 658 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 659 * Leave P_Key as 0 to be filled in by driver. 660 */ 661 662 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 663 { 664 __u32 addr; 665 unsigned char scope = broadcast[5] & 0xF; 666 667 buf[0] = 0; /* Reserved */ 668 buf[1] = 0xff; /* Multicast QPN */ 669 buf[2] = 0xff; 670 buf[3] = 0xff; 671 addr = ntohl(naddr); 672 buf[4] = 0xff; 673 buf[5] = 0x10 | scope; /* scope from broadcast address */ 674 buf[6] = 0x40; /* IPv4 signature */ 675 buf[7] = 0x1b; 676 buf[8] = broadcast[8]; /* P_Key */ 677 buf[9] = broadcast[9]; 678 buf[10] = 0; 679 buf[11] = 0; 680 buf[12] = 0; 681 buf[13] = 0; 682 buf[14] = 0; 683 buf[15] = 0; 684 buf[19] = addr & 0xff; 685 addr >>= 8; 686 buf[18] = addr & 0xff; 687 addr >>= 8; 688 buf[17] = addr & 0xff; 689 addr >>= 8; 690 buf[16] = addr & 0x0f; 691 } 692 693 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 694 { 695 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 696 memcpy(buf, broadcast, 4); 697 else 698 memcpy(buf, &naddr, sizeof(naddr)); 699 } 700 701 #if IS_ENABLED(CONFIG_IPV6) 702 #include <linux/ipv6.h> 703 #endif 704 705 static __inline__ void inet_reset_saddr(struct sock *sk) 706 { 707 inet_sk(sk)->inet_saddr = 0; 708 WRITE_ONCE(inet_sk(sk)->inet_rcv_saddr, 0); 709 #if IS_ENABLED(CONFIG_IPV6) 710 if (sk->sk_family == PF_INET6) { 711 struct ipv6_pinfo *np = inet6_sk(sk); 712 713 memset(&np->saddr, 0, sizeof(np->saddr)); 714 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 715 } 716 #endif 717 } 718 719 #endif 720 721 static inline unsigned int ipv4_addr_hash(__be32 ip) 722 { 723 return (__force unsigned int) ip; 724 } 725 726 static inline u32 __ipv4_addr_hash(const __be32 ip, const u32 initval) 727 { 728 return jhash_1word((__force u32)ip, initval); 729 } 730 731 static inline u32 ipv4_portaddr_hash(const struct net *net, 732 __be32 saddr, 733 unsigned int port) 734 { 735 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 736 } 737 738 bool ip_call_ra_chain(struct sk_buff *skb); 739 740 /* 741 * Functions provided by ip_fragment.c 742 */ 743 744 enum ip_defrag_users { 745 IP_DEFRAG_LOCAL_DELIVER, 746 IP_DEFRAG_CALL_RA_CHAIN, 747 IP_DEFRAG_CONNTRACK_IN, 748 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 749 IP_DEFRAG_CONNTRACK_OUT, 750 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 751 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 752 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 753 IP_DEFRAG_VS_IN, 754 IP_DEFRAG_VS_OUT, 755 IP_DEFRAG_VS_FWD, 756 IP_DEFRAG_AF_PACKET, 757 IP_DEFRAG_MACVLAN, 758 }; 759 760 /* Return true if the value of 'user' is between 'lower_bond' 761 * and 'upper_bond' inclusively. 762 */ 763 static inline bool ip_defrag_user_in_between(u32 user, 764 enum ip_defrag_users lower_bond, 765 enum ip_defrag_users upper_bond) 766 { 767 return user >= lower_bond && user <= upper_bond; 768 } 769 770 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 771 #ifdef CONFIG_INET 772 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 773 #else 774 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 775 { 776 return skb; 777 } 778 #endif 779 780 /* 781 * Functions provided by ip_forward.c 782 */ 783 784 int ip_forward(struct sk_buff *skb); 785 786 /* 787 * Functions provided by ip_options.c 788 */ 789 790 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 791 __be32 daddr, struct rtable *rt); 792 793 int __ip_options_echo(struct net *net, struct ip_options *dopt, 794 struct sk_buff *skb, const struct ip_options *sopt); 795 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 796 struct sk_buff *skb) 797 { 798 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 799 } 800 801 void ip_options_fragment(struct sk_buff *skb); 802 int __ip_options_compile(struct net *net, struct ip_options *opt, 803 struct sk_buff *skb, __be32 *info); 804 int ip_options_compile(struct net *net, struct ip_options *opt, 805 struct sk_buff *skb); 806 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 807 sockptr_t data, int optlen); 808 void ip_options_undo(struct ip_options *opt); 809 void ip_forward_options(struct sk_buff *skb); 810 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 811 812 /* 813 * Functions provided by ip_sockglue.c 814 */ 815 816 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst); 817 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 818 struct sk_buff *skb, int tlen, int offset); 819 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 820 struct ipcm_cookie *ipc, bool allow_ipv6); 821 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl); 822 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 823 unsigned int optlen); 824 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 825 unsigned int optlen); 826 int do_ip_getsockopt(struct sock *sk, int level, int optname, 827 sockptr_t optval, sockptr_t optlen); 828 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 829 int __user *optlen); 830 int ip_ra_control(struct sock *sk, unsigned char on, 831 void (*destructor)(struct sock *)); 832 833 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 834 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 835 u32 info, u8 *payload); 836 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 837 u32 info); 838 839 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 840 { 841 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 842 } 843 844 bool icmp_global_allow(struct net *net); 845 void icmp_global_consume(struct net *net); 846 847 #ifdef CONFIG_PROC_FS 848 int ip_misc_proc_init(void); 849 #endif 850 851 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 852 struct netlink_ext_ack *extack); 853 854 static inline bool inetdev_valid_mtu(unsigned int mtu) 855 { 856 return likely(mtu >= IPV4_MIN_MTU); 857 } 858 859 void ip_sock_set_freebind(struct sock *sk); 860 int ip_sock_set_mtu_discover(struct sock *sk, int val); 861 void ip_sock_set_pktinfo(struct sock *sk); 862 void ip_sock_set_recverr(struct sock *sk); 863 void ip_sock_set_tos(struct sock *sk, int val); 864 void __ip_sock_set_tos(struct sock *sk, int val); 865 866 #endif /* _IP_H */ 867