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, const struct sock *orig_sk, 292 struct sk_buff *skb, 293 const struct ip_options *sopt, 294 __be32 daddr, __be32 saddr, 295 const struct ip_reply_arg *arg, 296 unsigned int len, u64 transmit_time, u32 txhash); 297 298 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field) 299 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field) 300 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val) 301 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_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 __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val) 304 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 305 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field) 306 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 307 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd) 308 309 static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt) 310 { 311 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt); 312 } 313 314 unsigned long snmp_fold_field(void __percpu *mib, int offt); 315 #if BITS_PER_LONG==32 316 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 317 size_t syncp_offset); 318 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off); 319 #else 320 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct, 321 size_t syncp_offset) 322 { 323 return snmp_get_cpu_field(mib, cpu, offct); 324 325 } 326 327 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off) 328 { 329 return snmp_fold_field(mib, offt); 330 } 331 #endif 332 333 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \ 334 { \ 335 int i, c; \ 336 for_each_possible_cpu(c) { \ 337 for (i = 0; stats_list[i].name; i++) \ 338 buff64[i] += snmp_get_cpu_field64( \ 339 mib_statistic, \ 340 c, stats_list[i].entry, \ 341 offset); \ 342 } \ 343 } 344 345 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \ 346 { \ 347 int i, c; \ 348 for_each_possible_cpu(c) { \ 349 for (i = 0; stats_list[i].name; i++) \ 350 buff[i] += snmp_get_cpu_field( \ 351 mib_statistic, \ 352 c, stats_list[i].entry); \ 353 } \ 354 } 355 356 static inline void inet_get_local_port_range(const struct net *net, int *low, int *high) 357 { 358 u32 range = READ_ONCE(net->ipv4.ip_local_ports.range); 359 360 *low = range & 0xffff; 361 *high = range >> 16; 362 } 363 bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high); 364 365 #ifdef CONFIG_SYSCTL 366 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 367 { 368 if (!net->ipv4.sysctl_local_reserved_ports) 369 return false; 370 return test_bit(port, net->ipv4.sysctl_local_reserved_ports); 371 } 372 373 static inline bool sysctl_dev_name_is_allowed(const char *name) 374 { 375 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0; 376 } 377 378 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 379 { 380 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock); 381 } 382 383 #else 384 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port) 385 { 386 return false; 387 } 388 389 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port) 390 { 391 return port < PROT_SOCK; 392 } 393 #endif 394 395 __be32 inet_current_timestamp(void); 396 397 /* From inetpeer.c */ 398 extern int inet_peer_threshold; 399 extern int inet_peer_minttl; 400 extern int inet_peer_maxttl; 401 402 void ipfrag_init(void); 403 404 void ip_static_sysctl_init(void); 405 406 #define IP4_REPLY_MARK(net, mark) \ 407 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0) 408 409 static inline bool ip_is_fragment(const struct iphdr *iph) 410 { 411 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0; 412 } 413 414 #ifdef CONFIG_INET 415 #include <net/dst.h> 416 417 /* The function in 2.2 was invalid, producing wrong result for 418 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 419 static inline 420 int ip_decrease_ttl(struct iphdr *iph) 421 { 422 u32 check = (__force u32)iph->check; 423 check += (__force u32)htons(0x0100); 424 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 425 return --iph->ttl; 426 } 427 428 static inline dscp_t ip4h_dscp(const struct iphdr *ip4h) 429 { 430 return inet_dsfield_to_dscp(ip4h->tos); 431 } 432 433 static inline int ip_mtu_locked(const struct dst_entry *dst) 434 { 435 const struct rtable *rt = dst_rtable(dst); 436 437 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU); 438 } 439 440 static inline 441 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst) 442 { 443 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 444 445 return pmtudisc == IP_PMTUDISC_DO || 446 (pmtudisc == IP_PMTUDISC_WANT && 447 !ip_mtu_locked(dst)); 448 } 449 450 static inline bool ip_sk_accept_pmtu(const struct sock *sk) 451 { 452 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 453 454 return pmtudisc != IP_PMTUDISC_INTERFACE && 455 pmtudisc != IP_PMTUDISC_OMIT; 456 } 457 458 static inline bool ip_sk_use_pmtu(const struct sock *sk) 459 { 460 return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE; 461 } 462 463 static inline bool ip_sk_ignore_df(const struct sock *sk) 464 { 465 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc); 466 467 return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT; 468 } 469 470 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, 471 bool forwarding) 472 { 473 const struct rtable *rt = dst_rtable(dst); 474 struct net *net = dev_net(dst->dev); 475 unsigned int mtu; 476 477 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) || 478 ip_mtu_locked(dst) || 479 !forwarding) { 480 mtu = rt->rt_pmtu; 481 if (mtu && time_before(jiffies, rt->dst.expires)) 482 goto out; 483 } 484 485 /* 'forwarding = true' case should always honour route mtu */ 486 mtu = dst_metric_raw(dst, RTAX_MTU); 487 if (mtu) 488 goto out; 489 490 mtu = READ_ONCE(dst->dev->mtu); 491 492 if (unlikely(ip_mtu_locked(dst))) { 493 if (rt->rt_uses_gateway && mtu > 576) 494 mtu = 576; 495 } 496 497 out: 498 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 499 500 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 501 } 502 503 static inline unsigned int ip_skb_dst_mtu(struct sock *sk, 504 const struct sk_buff *skb) 505 { 506 unsigned int mtu; 507 508 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { 509 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; 510 511 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); 512 } 513 514 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU); 515 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu); 516 } 517 518 struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len, 519 struct netlink_ext_ack *extack); 520 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics) 521 { 522 if (fib_metrics != &dst_default_metrics && 523 refcount_dec_and_test(&fib_metrics->refcnt)) 524 kfree(fib_metrics); 525 } 526 527 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */ 528 static inline 529 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics) 530 { 531 dst_init_metrics(dst, fib_metrics->metrics, true); 532 533 if (fib_metrics != &dst_default_metrics) { 534 dst->_metrics |= DST_METRICS_REFCOUNTED; 535 refcount_inc(&fib_metrics->refcnt); 536 } 537 } 538 539 static inline 540 void ip_dst_metrics_put(struct dst_entry *dst) 541 { 542 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 543 544 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 545 kfree(p); 546 } 547 548 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs); 549 550 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb, 551 struct sock *sk, int segs) 552 { 553 struct iphdr *iph = ip_hdr(skb); 554 555 /* We had many attacks based on IPID, use the private 556 * generator as much as we can. 557 */ 558 if (sk && inet_sk(sk)->inet_daddr) { 559 int val; 560 561 /* avoid atomic operations for TCP, 562 * as we hold socket lock at this point. 563 */ 564 if (sk_is_tcp(sk)) { 565 sock_owned_by_me(sk); 566 val = atomic_read(&inet_sk(sk)->inet_id); 567 atomic_set(&inet_sk(sk)->inet_id, val + segs); 568 } else { 569 val = atomic_add_return(segs, &inet_sk(sk)->inet_id); 570 } 571 iph->id = htons(val); 572 return; 573 } 574 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) { 575 iph->id = 0; 576 } else { 577 /* Unfortunately we need the big hammer to get a suitable IPID */ 578 __ip_select_ident(net, iph, segs); 579 } 580 } 581 582 static inline void ip_select_ident(struct net *net, struct sk_buff *skb, 583 struct sock *sk) 584 { 585 ip_select_ident_segs(net, skb, sk, 1); 586 } 587 588 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto) 589 { 590 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, 591 skb->len, proto, 0); 592 } 593 594 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store 595 * Equivalent to : flow->v4addrs.src = iph->saddr; 596 * flow->v4addrs.dst = iph->daddr; 597 */ 598 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow, 599 const struct iphdr *iph) 600 { 601 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) != 602 offsetof(typeof(flow->addrs), v4addrs.src) + 603 sizeof(flow->addrs.v4addrs.src)); 604 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs)); 605 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 606 } 607 608 /* 609 * Map a multicast IP onto multicast MAC for type ethernet. 610 */ 611 612 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 613 { 614 __u32 addr=ntohl(naddr); 615 buf[0]=0x01; 616 buf[1]=0x00; 617 buf[2]=0x5e; 618 buf[5]=addr&0xFF; 619 addr>>=8; 620 buf[4]=addr&0xFF; 621 addr>>=8; 622 buf[3]=addr&0x7F; 623 } 624 625 /* 626 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 627 * Leave P_Key as 0 to be filled in by driver. 628 */ 629 630 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 631 { 632 __u32 addr; 633 unsigned char scope = broadcast[5] & 0xF; 634 635 buf[0] = 0; /* Reserved */ 636 buf[1] = 0xff; /* Multicast QPN */ 637 buf[2] = 0xff; 638 buf[3] = 0xff; 639 addr = ntohl(naddr); 640 buf[4] = 0xff; 641 buf[5] = 0x10 | scope; /* scope from broadcast address */ 642 buf[6] = 0x40; /* IPv4 signature */ 643 buf[7] = 0x1b; 644 buf[8] = broadcast[8]; /* P_Key */ 645 buf[9] = broadcast[9]; 646 buf[10] = 0; 647 buf[11] = 0; 648 buf[12] = 0; 649 buf[13] = 0; 650 buf[14] = 0; 651 buf[15] = 0; 652 buf[19] = addr & 0xff; 653 addr >>= 8; 654 buf[18] = addr & 0xff; 655 addr >>= 8; 656 buf[17] = addr & 0xff; 657 addr >>= 8; 658 buf[16] = addr & 0x0f; 659 } 660 661 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 662 { 663 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) 664 memcpy(buf, broadcast, 4); 665 else 666 memcpy(buf, &naddr, sizeof(naddr)); 667 } 668 669 #if IS_ENABLED(CONFIG_IPV6) 670 #include <linux/ipv6.h> 671 #endif 672 673 static __inline__ void inet_reset_saddr(struct sock *sk) 674 { 675 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0; 676 #if IS_ENABLED(CONFIG_IPV6) 677 if (sk->sk_family == PF_INET6) { 678 struct ipv6_pinfo *np = inet6_sk(sk); 679 680 memset(&np->saddr, 0, sizeof(np->saddr)); 681 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 682 } 683 #endif 684 } 685 686 #endif 687 688 static inline unsigned int ipv4_addr_hash(__be32 ip) 689 { 690 return (__force unsigned int) ip; 691 } 692 693 static inline u32 __ipv4_addr_hash(const __be32 ip, const u32 initval) 694 { 695 return jhash_1word((__force u32)ip, initval); 696 } 697 698 static inline u32 ipv4_portaddr_hash(const struct net *net, 699 __be32 saddr, 700 unsigned int port) 701 { 702 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port; 703 } 704 705 bool ip_call_ra_chain(struct sk_buff *skb); 706 707 /* 708 * Functions provided by ip_fragment.c 709 */ 710 711 enum ip_defrag_users { 712 IP_DEFRAG_LOCAL_DELIVER, 713 IP_DEFRAG_CALL_RA_CHAIN, 714 IP_DEFRAG_CONNTRACK_IN, 715 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX, 716 IP_DEFRAG_CONNTRACK_OUT, 717 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX, 718 IP_DEFRAG_CONNTRACK_BRIDGE_IN, 719 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX, 720 IP_DEFRAG_VS_IN, 721 IP_DEFRAG_VS_OUT, 722 IP_DEFRAG_VS_FWD, 723 IP_DEFRAG_AF_PACKET, 724 IP_DEFRAG_MACVLAN, 725 }; 726 727 /* Return true if the value of 'user' is between 'lower_bond' 728 * and 'upper_bond' inclusively. 729 */ 730 static inline bool ip_defrag_user_in_between(u32 user, 731 enum ip_defrag_users lower_bond, 732 enum ip_defrag_users upper_bond) 733 { 734 return user >= lower_bond && user <= upper_bond; 735 } 736 737 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user); 738 #ifdef CONFIG_INET 739 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user); 740 #else 741 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) 742 { 743 return skb; 744 } 745 #endif 746 747 /* 748 * Functions provided by ip_forward.c 749 */ 750 751 int ip_forward(struct sk_buff *skb); 752 753 /* 754 * Functions provided by ip_options.c 755 */ 756 757 void ip_options_build(struct sk_buff *skb, struct ip_options *opt, 758 __be32 daddr, struct rtable *rt); 759 760 int __ip_options_echo(struct net *net, struct ip_options *dopt, 761 struct sk_buff *skb, const struct ip_options *sopt); 762 static inline int ip_options_echo(struct net *net, struct ip_options *dopt, 763 struct sk_buff *skb) 764 { 765 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt); 766 } 767 768 void ip_options_fragment(struct sk_buff *skb); 769 int __ip_options_compile(struct net *net, struct ip_options *opt, 770 struct sk_buff *skb, __be32 *info); 771 int ip_options_compile(struct net *net, struct ip_options *opt, 772 struct sk_buff *skb); 773 int ip_options_get(struct net *net, struct ip_options_rcu **optp, 774 sockptr_t data, int optlen); 775 void ip_options_undo(struct ip_options *opt); 776 void ip_forward_options(struct sk_buff *skb); 777 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev); 778 779 /* 780 * Functions provided by ip_sockglue.c 781 */ 782 783 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst); 784 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk, 785 struct sk_buff *skb, int tlen, int offset); 786 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, 787 struct ipcm_cookie *ipc, bool allow_ipv6); 788 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl); 789 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 790 unsigned int optlen); 791 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 792 unsigned int optlen); 793 int do_ip_getsockopt(struct sock *sk, int level, int optname, 794 sockptr_t optval, sockptr_t optlen); 795 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, 796 int __user *optlen); 797 int ip_ra_control(struct sock *sk, unsigned char on, 798 void (*destructor)(struct sock *)); 799 800 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len); 801 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port, 802 u32 info, u8 *payload); 803 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 804 u32 info); 805 806 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb) 807 { 808 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0); 809 } 810 811 bool icmp_global_allow(struct net *net); 812 void icmp_global_consume(struct net *net); 813 814 #ifdef CONFIG_PROC_FS 815 int ip_misc_proc_init(void); 816 #endif 817 818 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family, 819 struct netlink_ext_ack *extack); 820 821 static inline bool inetdev_valid_mtu(unsigned int mtu) 822 { 823 return likely(mtu >= IPV4_MIN_MTU); 824 } 825 826 void ip_sock_set_freebind(struct sock *sk); 827 int ip_sock_set_mtu_discover(struct sock *sk, int val); 828 void ip_sock_set_pktinfo(struct sock *sk); 829 void ip_sock_set_recverr(struct sock *sk); 830 void ip_sock_set_tos(struct sock *sk, int val); 831 void __ip_sock_set_tos(struct sock *sk, int val); 832 833 #endif /* _IP_H */ 834