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