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