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 #define IPSKB_MULTIPATH BIT(9) 61 62 u16 frag_max_size; 63 }; 64 65 static inline bool ipv4_l3mdev_skb(u16 flags) 66 { 67 return !!(flags & IPSKB_L3SLAVE); 68 } 69 70 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 71 { 72 return ip_hdr(skb)->ihl * 4; 73 } 74 75 struct 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 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_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 */ 108 static 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 */ 127 128 struct 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 */ 145 146 struct msghdr; 147 struct net_device; 148 struct packet_type; 149 struct rtable; 150 struct sockaddr; 151 152 int igmp_mc_init(void); 153 154 /* 155 * Functions provided by ip.c 156 */ 157 158 int 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); 161 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 162 struct net_device *orig_dev); 163 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 164 struct net_device *orig_dev); 165 int ip_local_deliver(struct sk_buff *skb); 166 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto); 167 int ip_mr_input(struct sk_buff *skb); 168 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); 169 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); 170 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 171 int (*output)(struct net *, struct sock *, struct sk_buff *)); 172 173 struct ip_fraglist_iter { 174 struct sk_buff *frag; 175 struct iphdr *iph; 176 int offset; 177 unsigned int hlen; 178 }; 179 180 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, 181 unsigned int hlen, struct ip_fraglist_iter *iter); 182 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); 183 184 static 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 } 193 194 struct 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 }; 204 205 void 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); 207 struct sk_buff *ip_frag_next(struct sk_buff *skb, 208 struct ip_frag_state *state); 209 210 void ip_send_check(struct iphdr *ip); 211 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 212 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); 213 214 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 215 __u8 tos); 216 void ip_init(void); 217 int 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); 224 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, 225 struct sk_buff *skb); 226 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4, 227 struct sk_buff_head *queue, 228 struct inet_cork *cork); 229 int ip_send_skb(struct net *net, struct sk_buff *skb); 230 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4); 231 void ip_flush_pending_frames(struct sock *sk); 232 struct 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); 238 239 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl); 240 241 static 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. */ 247 static 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 } 258 259 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet) 260 { 261 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(READ_ONCE(inet->tos)); 262 } 263 264 /* datagram.c */ 265 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 266 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 267 268 void ip4_datagram_release_cb(struct sock *sk); 269 270 struct 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 1 282 283 static 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 } 287 288 void 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) 304 305 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(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 } 351 352 static inline void inet_get_local_port_range(const struct net *net, int *low, int *high) 353 { 354 u32 range = READ_ONCE(net->ipv4.ip_local_ports.range); 355 356 *low = range & 0xffff; 357 *high = range >> 16; 358 } 359 bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high); 360 361 #ifdef CONFIG_SYSCTL 362 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 363 { 364 if (!net->ipv4.sysctl_local_reserved_ports) 365 return false; 366 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 367 } 368 369 static inline bool sysctl_dev_name_is_allowed(const char *name) 370 { 371 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 372 } 373 374 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 375 { 376 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock); 377 } 378 379 #else 380 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 381 { 382 return false; 383 } 384 385 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 386 { 387 return port < PROT_SOCK; 388 } 389 #endif 390 391 __be32 inet_current_timestamp(void); 392 393 /* From inetpeer.c */ 394 extern int inet_peer_threshold; 395 extern int inet_peer_minttl; 396 extern int inet_peer_maxttl; 397 398 void ipfrag_init(void); 399 400 void ip_static_sysctl_init(void); 401 402 #define IP4_REPLY_MARK(net, mark) \ 403 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0) 404 405 static inline bool ip_is_fragment(const struct iphdr *iph) 406 { 407 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 408 } 409 410 #ifdef CONFIG_INET 411 #include <net/dst.h> 412 413 /* The function in 2.2 was invalid, producing wrong result for 414 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 415 static inline 416 int ip_decrease_ttl(struct iphdr *iph) 417 { 418 u32 check = (__force u32)iph->check; 419 check += (__force u32)htons(0x0100); 420 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 421 return --iph->ttl; 422 } 423 424 static inline int ip_mtu_locked(const struct dst_entry *dst) 425 { 426 const struct rtable *rt = dst_rtable(dst); 427 428 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 429 } 430 431 static inline 432 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 433 { 434 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 435 436 return pmtudisc == IP_PMTUDISC_DO || 437 (pmtudisc == IP_PMTUDISC_WANT && 438 !ip_mtu_locked(dst)); 439 } 440 441 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 442 { 443 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 444 445 return pmtudisc != IP_PMTUDISC_INTERFACE && 446 pmtudisc != IP_PMTUDISC_OMIT; 447 } 448 449 static inline bool ip_sk_use_pmtu(const struct sock *sk) 450 { 451 return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE; 452 } 453 454 static inline bool ip_sk_ignore_df(const struct sock *sk) 455 { 456 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 457 458 return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT; 459 } 460 461 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 462 bool forwarding) 463 { 464 const struct rtable *rt = dst_rtable(dst); 465 struct net *net = dev_net(dst->dev); 466 unsigned int mtu; 467 468 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || 469 ip_mtu_locked(dst) || 470 !forwarding) { 471 mtu = rt->rt_pmtu; 472 if (mtu && time_before(jiffies, rt->dst.expires)) 473 goto out; 474 } 475 476 /* 'forwarding = true' case should always honour route mtu */ 477 mtu = dst_metric_raw(dst, RTAX_MTU); 478 if (mtu) 479 goto out; 480 481 mtu = READ_ONCE(dst->dev->mtu); 482 483 if (unlikely(ip_mtu_locked(dst))) { 484 if (rt->rt_uses_gateway && mtu > 576) 485 mtu = 576; 486 } 487 488 out: 489 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 490 491 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 492 } 493 494 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 495 const struct sk_buff *skb) 496 { 497 unsigned int mtu; 498 499 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 500 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 501 502 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); 503 } 504 505 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); 506 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 507 } 508 509 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx, 510 int fc_mx_len, 511 struct netlink_ext_ack *extack); 512 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 513 { 514 if (fib_metrics != &dst_default_metrics && 515 refcount_dec_and_test(&fib_metrics->refcnt)) 516 kfree(fib_metrics); 517 } 518 519 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 520 static inline 521 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 522 { 523 dst_init_metrics(dst, fib_metrics->metrics, true); 524 525 if (fib_metrics != &dst_default_metrics) { 526 dst->_metrics |= DST_METRICS_REFCOUNTED; 527 refcount_inc(&fib_metrics->refcnt); 528 } 529 } 530 531 static inline 532 void ip_dst_metrics_put(struct dst_entry *dst) 533 { 534 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 535 536 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 537 kfree(p); 538 } 539 540 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); 541 542 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, 543 struct sock *sk, int segs) 544 { 545 struct iphdr *iph = ip_hdr(skb); 546 547 /* We had many attacks based on IPID, use the private 548 * generator as much as we can. 549 */ 550 if (sk && inet_sk(sk)->inet_daddr) { 551 int val; 552 553 /* avoid atomic operations for TCP, 554 * as we hold socket lock at this point. 555 */ 556 if (sk_is_tcp(sk)) { 557 sock_owned_by_me(sk); 558 val = atomic_read(&inet_sk(sk)->inet_id); 559 atomic_set(&inet_sk(sk)->inet_id, val + segs); 560 } else { 561 val = atomic_add_return(segs, &inet_sk(sk)->inet_id); 562 } 563 iph->id = htons(val); 564 return; 565 } 566 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 567 iph->id = 0; 568 } else { 569 /* Unfortunately we need the big hammer to get a suitable IPID */ 570 __ip_select_ident(net, iph, segs); 571 } 572 } 573 574 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 575 struct sock *sk) 576 { 577 ip_select_ident_segs(net, skb, sk, 1); 578 } 579 580 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 581 { 582 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 583 skb->len, proto, 0); 584 } 585 586 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 587 * Equivalent to : flow->v4addrs.src = iph->saddr; 588 * flow->v4addrs.dst = iph->daddr; 589 */ 590 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 591 const struct iphdr *iph) 592 { 593 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 594 offsetof(typeof(flow->addrs), v4addrs.src) + 595 sizeof(flow->addrs.v4addrs.src)); 596 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs)); 597 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 598 } 599 600 /* 601 * Map a multicast IP onto multicast MAC for type ethernet. 602 */ 603 604 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 605 { 606 __u32 addr=ntohl(naddr); 607 buf[0]=0x01; 608 buf[1]=0x00; 609 buf[2]=0x5e; 610 buf[5]=addr&0xFF; 611 addr>>=8; 612 buf[4]=addr&0xFF; 613 addr>>=8; 614 buf[3]=addr&0x7F; 615 } 616 617 /* 618 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 619 * Leave P_Key as 0 to be filled in by driver. 620 */ 621 622 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 623 { 624 __u32 addr; 625 unsigned char scope = broadcast[5] & 0xF; 626 627 buf[0] = 0; /* Reserved */ 628 buf[1] = 0xff; /* Multicast QPN */ 629 buf[2] = 0xff; 630 buf[3] = 0xff; 631 addr = ntohl(naddr); 632 buf[4] = 0xff; 633 buf[5] = 0x10 | scope; /* scope from broadcast address */ 634 buf[6] = 0x40; /* IPv4 signature */ 635 buf[7] = 0x1b; 636 buf[8] = broadcast[8]; /* P_Key */ 637 buf[9] = broadcast[9]; 638 buf[10] = 0; 639 buf[11] = 0; 640 buf[12] = 0; 641 buf[13] = 0; 642 buf[14] = 0; 643 buf[15] = 0; 644 buf[19] = addr & 0xff; 645 addr >>= 8; 646 buf[18] = addr & 0xff; 647 addr >>= 8; 648 buf[17] = addr & 0xff; 649 addr >>= 8; 650 buf[16] = addr & 0x0f; 651 } 652 653 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 654 { 655 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 656 memcpy(buf, broadcast, 4); 657 else 658 memcpy(buf, &naddr, sizeof(naddr)); 659 } 660 661 #if IS_ENABLED(CONFIG_IPV6) 662 #include <linux/ipv6.h> 663 #endif 664 665 static __inline__ void inet_reset_saddr(struct sock *sk) 666 { 667 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 668 #if IS_ENABLED(CONFIG_IPV6) 669 if (sk->sk_family == PF_INET6) { 670 struct ipv6_pinfo *np = inet6_sk(sk); 671 672 memset(&np->saddr, 0, sizeof(np->saddr)); 673 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 674 } 675 #endif 676 } 677 678 #endif 679 680 static inline unsigned int ipv4_addr_hash(__be32 ip) 681 { 682 return (__force unsigned int) ip; 683 } 684 685 static inline u32 ipv4_portaddr_hash(const struct net *net, 686 __be32 saddr, 687 unsigned int port) 688 { 689 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 690 } 691 692 bool ip_call_ra_chain(struct sk_buff *skb); 693 694 /* 695 * Functions provided by ip_fragment.c 696 */ 697 698 enum ip_defrag_users { 699 IP_DEFRAG_LOCAL_DELIVER, 700 IP_DEFRAG_CALL_RA_CHAIN, 701 IP_DEFRAG_CONNTRACK_IN, 702 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 703 IP_DEFRAG_CONNTRACK_OUT, 704 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 705 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 706 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 707 IP_DEFRAG_VS_IN, 708 IP_DEFRAG_VS_OUT, 709 IP_DEFRAG_VS_FWD, 710 IP_DEFRAG_AF_PACKET, 711 IP_DEFRAG_MACVLAN, 712 }; 713 714 /* Return true if the value of 'user' is between 'lower_bond' 715 * and 'upper_bond' inclusively. 716 */ 717 static inline bool ip_defrag_user_in_between(u32 user, 718 enum ip_defrag_users lower_bond, 719 enum ip_defrag_users upper_bond) 720 { 721 return user >= lower_bond && user <= upper_bond; 722 } 723 724 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 725 #ifdef CONFIG_INET 726 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 727 #else 728 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 729 { 730 return skb; 731 } 732 #endif 733 734 /* 735 * Functions provided by ip_forward.c 736 */ 737 738 int ip_forward(struct sk_buff *skb); 739 740 /* 741 * Functions provided by ip_options.c 742 */ 743 744 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 745 __be32 daddr, struct rtable *rt); 746 747 int __ip_options_echo(struct net *net, struct ip_options *dopt, 748 struct sk_buff *skb, const struct ip_options *sopt); 749 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 750 struct sk_buff *skb) 751 { 752 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 753 } 754 755 void ip_options_fragment(struct sk_buff *skb); 756 int __ip_options_compile(struct net *net, struct ip_options *opt, 757 struct sk_buff *skb, __be32 *info); 758 int ip_options_compile(struct net *net, struct ip_options *opt, 759 struct sk_buff *skb); 760 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 761 sockptr_t data, int optlen); 762 void ip_options_undo(struct ip_options *opt); 763 void ip_forward_options(struct sk_buff *skb); 764 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 765 766 /* 767 * Functions provided by ip_sockglue.c 768 */ 769 770 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst); 771 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 772 struct sk_buff *skb, int tlen, int offset); 773 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 774 struct ipcm_cookie *ipc, bool allow_ipv6); 775 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl); 776 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 777 unsigned int optlen); 778 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 779 unsigned int optlen); 780 int do_ip_getsockopt(struct sock *sk, int level, int optname, 781 sockptr_t optval, sockptr_t optlen); 782 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 783 int __user *optlen); 784 int ip_ra_control(struct sock *sk, unsigned char on, 785 void (*destructor)(struct sock *)); 786 787 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 788 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 789 u32 info, u8 *payload); 790 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 791 u32 info); 792 793 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 794 { 795 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 796 } 797 798 bool icmp_global_allow(void); 799 extern int sysctl_icmp_msgs_per_sec; 800 extern int sysctl_icmp_msgs_burst; 801 802 #ifdef CONFIG_PROC_FS 803 int ip_misc_proc_init(void); 804 #endif 805 806 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 807 struct netlink_ext_ack *extack); 808 809 static inline bool inetdev_valid_mtu(unsigned int mtu) 810 { 811 return likely(mtu >= IPV4_MIN_MTU); 812 } 813 814 void ip_sock_set_freebind(struct sock *sk); 815 int ip_sock_set_mtu_discover(struct sock *sk, int val); 816 void ip_sock_set_pktinfo(struct sock *sk); 817 void ip_sock_set_recverr(struct sock *sk); 818 void ip_sock_set_tos(struct sock *sk, int val); 819 void __ip_sock_set_tos(struct sock *sk, int val); 820 821 #endif /* _IP_H */ 822