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 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/uaccess.h> 65 #include <linux/bitops.h> 66 #include <linux/types.h> 67 #include <linux/kernel.h> 68 #include <linux/mm.h> 69 #include <linux/memblock.h> 70 #include <linux/string.h> 71 #include <linux/socket.h> 72 #include <linux/sockios.h> 73 #include <linux/errno.h> 74 #include <linux/in.h> 75 #include <linux/inet.h> 76 #include <linux/netdevice.h> 77 #include <linux/proc_fs.h> 78 #include <linux/init.h> 79 #include <linux/skbuff.h> 80 #include <linux/inetdevice.h> 81 #include <linux/igmp.h> 82 #include <linux/pkt_sched.h> 83 #include <linux/mroute.h> 84 #include <linux/netfilter_ipv4.h> 85 #include <linux/random.h> 86 #include <linux/rcupdate.h> 87 #include <linux/times.h> 88 #include <linux/slab.h> 89 #include <linux/jhash.h> 90 #include <net/dst.h> 91 #include <net/dst_metadata.h> 92 #include <net/net_namespace.h> 93 #include <net/protocol.h> 94 #include <net/ip.h> 95 #include <net/route.h> 96 #include <net/inetpeer.h> 97 #include <net/sock.h> 98 #include <net/ip_fib.h> 99 #include <net/nexthop.h> 100 #include <net/arp.h> 101 #include <net/tcp.h> 102 #include <net/icmp.h> 103 #include <net/xfrm.h> 104 #include <net/lwtunnel.h> 105 #include <net/netevent.h> 106 #include <net/rtnetlink.h> 107 #ifdef CONFIG_SYSCTL 108 #include <linux/sysctl.h> 109 #endif 110 #include <net/secure_seq.h> 111 #include <net/ip_tunnels.h> 112 #include <net/l3mdev.h> 113 114 #include "fib_lookup.h" 115 116 #define RT_FL_TOS(oldflp4) \ 117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 118 119 #define RT_GC_TIMEOUT (300*HZ) 120 121 static int ip_rt_max_size; 122 static int ip_rt_redirect_number __read_mostly = 9; 123 static int ip_rt_redirect_load __read_mostly = HZ / 50; 124 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 125 static int ip_rt_error_cost __read_mostly = HZ; 126 static int ip_rt_error_burst __read_mostly = 5 * HZ; 127 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 128 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 129 static int ip_rt_min_advmss __read_mostly = 256; 130 131 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 132 133 /* 134 * Interface to generic destination cache. 135 */ 136 137 INDIRECT_CALLABLE_SCOPE 138 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 140 INDIRECT_CALLABLE_SCOPE 141 unsigned int ipv4_mtu(const struct dst_entry *dst); 142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 143 static void ipv4_link_failure(struct sk_buff *skb); 144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 145 struct sk_buff *skb, u32 mtu, 146 bool confirm_neigh); 147 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 148 struct sk_buff *skb); 149 static void ipv4_dst_destroy(struct dst_entry *dst); 150 151 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 152 { 153 WARN_ON(1); 154 return NULL; 155 } 156 157 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 158 struct sk_buff *skb, 159 const void *daddr); 160 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 161 162 static struct dst_ops ipv4_dst_ops = { 163 .family = AF_INET, 164 .check = ipv4_dst_check, 165 .default_advmss = ipv4_default_advmss, 166 .mtu = ipv4_mtu, 167 .cow_metrics = ipv4_cow_metrics, 168 .destroy = ipv4_dst_destroy, 169 .negative_advice = ipv4_negative_advice, 170 .link_failure = ipv4_link_failure, 171 .update_pmtu = ip_rt_update_pmtu, 172 .redirect = ip_do_redirect, 173 .local_out = __ip_local_out, 174 .neigh_lookup = ipv4_neigh_lookup, 175 .confirm_neigh = ipv4_confirm_neigh, 176 }; 177 178 #define ECN_OR_COST(class) TC_PRIO_##class 179 180 const __u8 ip_tos2prio[16] = { 181 TC_PRIO_BESTEFFORT, 182 ECN_OR_COST(BESTEFFORT), 183 TC_PRIO_BESTEFFORT, 184 ECN_OR_COST(BESTEFFORT), 185 TC_PRIO_BULK, 186 ECN_OR_COST(BULK), 187 TC_PRIO_BULK, 188 ECN_OR_COST(BULK), 189 TC_PRIO_INTERACTIVE, 190 ECN_OR_COST(INTERACTIVE), 191 TC_PRIO_INTERACTIVE, 192 ECN_OR_COST(INTERACTIVE), 193 TC_PRIO_INTERACTIVE_BULK, 194 ECN_OR_COST(INTERACTIVE_BULK), 195 TC_PRIO_INTERACTIVE_BULK, 196 ECN_OR_COST(INTERACTIVE_BULK) 197 }; 198 EXPORT_SYMBOL(ip_tos2prio); 199 200 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 201 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 202 203 #ifdef CONFIG_PROC_FS 204 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 205 { 206 if (*pos) 207 return NULL; 208 return SEQ_START_TOKEN; 209 } 210 211 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 212 { 213 ++*pos; 214 return NULL; 215 } 216 217 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 218 { 219 } 220 221 static int rt_cache_seq_show(struct seq_file *seq, void *v) 222 { 223 if (v == SEQ_START_TOKEN) 224 seq_printf(seq, "%-127s\n", 225 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 226 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 227 "HHUptod\tSpecDst"); 228 return 0; 229 } 230 231 static const struct seq_operations rt_cache_seq_ops = { 232 .start = rt_cache_seq_start, 233 .next = rt_cache_seq_next, 234 .stop = rt_cache_seq_stop, 235 .show = rt_cache_seq_show, 236 }; 237 238 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 239 { 240 int cpu; 241 242 if (*pos == 0) 243 return SEQ_START_TOKEN; 244 245 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 246 if (!cpu_possible(cpu)) 247 continue; 248 *pos = cpu+1; 249 return &per_cpu(rt_cache_stat, cpu); 250 } 251 return NULL; 252 } 253 254 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 255 { 256 int cpu; 257 258 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 259 if (!cpu_possible(cpu)) 260 continue; 261 *pos = cpu+1; 262 return &per_cpu(rt_cache_stat, cpu); 263 } 264 (*pos)++; 265 return NULL; 266 267 } 268 269 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 270 { 271 272 } 273 274 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 275 { 276 struct rt_cache_stat *st = v; 277 278 if (v == SEQ_START_TOKEN) { 279 seq_puts(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 280 return 0; 281 } 282 283 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 284 "%08x %08x %08x %08x %08x %08x " 285 "%08x %08x %08x %08x\n", 286 dst_entries_get_slow(&ipv4_dst_ops), 287 0, /* st->in_hit */ 288 st->in_slow_tot, 289 st->in_slow_mc, 290 st->in_no_route, 291 st->in_brd, 292 st->in_martian_dst, 293 st->in_martian_src, 294 295 0, /* st->out_hit */ 296 st->out_slow_tot, 297 st->out_slow_mc, 298 299 0, /* st->gc_total */ 300 0, /* st->gc_ignored */ 301 0, /* st->gc_goal_miss */ 302 0, /* st->gc_dst_overflow */ 303 0, /* st->in_hlist_search */ 304 0 /* st->out_hlist_search */ 305 ); 306 return 0; 307 } 308 309 static const struct seq_operations rt_cpu_seq_ops = { 310 .start = rt_cpu_seq_start, 311 .next = rt_cpu_seq_next, 312 .stop = rt_cpu_seq_stop, 313 .show = rt_cpu_seq_show, 314 }; 315 316 #ifdef CONFIG_IP_ROUTE_CLASSID 317 static int rt_acct_proc_show(struct seq_file *m, void *v) 318 { 319 struct ip_rt_acct *dst, *src; 320 unsigned int i, j; 321 322 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 323 if (!dst) 324 return -ENOMEM; 325 326 for_each_possible_cpu(i) { 327 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 328 for (j = 0; j < 256; j++) { 329 dst[j].o_bytes += src[j].o_bytes; 330 dst[j].o_packets += src[j].o_packets; 331 dst[j].i_bytes += src[j].i_bytes; 332 dst[j].i_packets += src[j].i_packets; 333 } 334 } 335 336 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 337 kfree(dst); 338 return 0; 339 } 340 #endif 341 342 static int __net_init ip_rt_do_proc_init(struct net *net) 343 { 344 struct proc_dir_entry *pde; 345 346 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 347 &rt_cache_seq_ops); 348 if (!pde) 349 goto err1; 350 351 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 352 &rt_cpu_seq_ops); 353 if (!pde) 354 goto err2; 355 356 #ifdef CONFIG_IP_ROUTE_CLASSID 357 pde = proc_create_single("rt_acct", 0, net->proc_net, 358 rt_acct_proc_show); 359 if (!pde) 360 goto err3; 361 #endif 362 return 0; 363 364 #ifdef CONFIG_IP_ROUTE_CLASSID 365 err3: 366 remove_proc_entry("rt_cache", net->proc_net_stat); 367 #endif 368 err2: 369 remove_proc_entry("rt_cache", net->proc_net); 370 err1: 371 return -ENOMEM; 372 } 373 374 static void __net_exit ip_rt_do_proc_exit(struct net *net) 375 { 376 remove_proc_entry("rt_cache", net->proc_net_stat); 377 remove_proc_entry("rt_cache", net->proc_net); 378 #ifdef CONFIG_IP_ROUTE_CLASSID 379 remove_proc_entry("rt_acct", net->proc_net); 380 #endif 381 } 382 383 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 384 .init = ip_rt_do_proc_init, 385 .exit = ip_rt_do_proc_exit, 386 }; 387 388 static int __init ip_rt_proc_init(void) 389 { 390 return register_pernet_subsys(&ip_rt_proc_ops); 391 } 392 393 #else 394 static inline int ip_rt_proc_init(void) 395 { 396 return 0; 397 } 398 #endif /* CONFIG_PROC_FS */ 399 400 static inline bool rt_is_expired(const struct rtable *rth) 401 { 402 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 403 } 404 405 void rt_cache_flush(struct net *net) 406 { 407 rt_genid_bump_ipv4(net); 408 } 409 410 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 411 struct sk_buff *skb, 412 const void *daddr) 413 { 414 const struct rtable *rt = container_of(dst, struct rtable, dst); 415 struct net_device *dev = dst->dev; 416 struct neighbour *n; 417 418 rcu_read_lock_bh(); 419 420 if (likely(rt->rt_gw_family == AF_INET)) { 421 n = ip_neigh_gw4(dev, rt->rt_gw4); 422 } else if (rt->rt_gw_family == AF_INET6) { 423 n = ip_neigh_gw6(dev, &rt->rt_gw6); 424 } else { 425 __be32 pkey; 426 427 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 428 n = ip_neigh_gw4(dev, pkey); 429 } 430 431 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 432 n = NULL; 433 434 rcu_read_unlock_bh(); 435 436 return n; 437 } 438 439 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 440 { 441 const struct rtable *rt = container_of(dst, struct rtable, dst); 442 struct net_device *dev = dst->dev; 443 const __be32 *pkey = daddr; 444 445 if (rt->rt_gw_family == AF_INET) { 446 pkey = (const __be32 *)&rt->rt_gw4; 447 } else if (rt->rt_gw_family == AF_INET6) { 448 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 449 } else if (!daddr || 450 (rt->rt_flags & 451 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 452 return; 453 } 454 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 455 } 456 457 /* Hash tables of size 2048..262144 depending on RAM size. 458 * Each bucket uses 8 bytes. 459 */ 460 static u32 ip_idents_mask __read_mostly; 461 static atomic_t *ip_idents __read_mostly; 462 static u32 *ip_tstamps __read_mostly; 463 464 /* In order to protect privacy, we add a perturbation to identifiers 465 * if one generator is seldom used. This makes hard for an attacker 466 * to infer how many packets were sent between two points in time. 467 */ 468 u32 ip_idents_reserve(u32 hash, int segs) 469 { 470 u32 bucket, old, now = (u32)jiffies; 471 atomic_t *p_id; 472 u32 *p_tstamp; 473 u32 delta = 0; 474 475 bucket = hash & ip_idents_mask; 476 p_tstamp = ip_tstamps + bucket; 477 p_id = ip_idents + bucket; 478 old = READ_ONCE(*p_tstamp); 479 480 if (old != now && cmpxchg(p_tstamp, old, now) == old) 481 delta = prandom_u32_max(now - old); 482 483 /* If UBSAN reports an error there, please make sure your compiler 484 * supports -fno-strict-overflow before reporting it that was a bug 485 * in UBSAN, and it has been fixed in GCC-8. 486 */ 487 return atomic_add_return(segs + delta, p_id) - segs; 488 } 489 EXPORT_SYMBOL(ip_idents_reserve); 490 491 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 492 { 493 u32 hash, id; 494 495 /* Note the following code is not safe, but this is okay. */ 496 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 497 get_random_bytes(&net->ipv4.ip_id_key, 498 sizeof(net->ipv4.ip_id_key)); 499 500 hash = siphash_3u32((__force u32)iph->daddr, 501 (__force u32)iph->saddr, 502 iph->protocol, 503 &net->ipv4.ip_id_key); 504 id = ip_idents_reserve(hash, segs); 505 iph->id = htons(id); 506 } 507 EXPORT_SYMBOL(__ip_select_ident); 508 509 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 510 const struct sock *sk, 511 const struct iphdr *iph, 512 int oif, u8 tos, 513 u8 prot, u32 mark, int flow_flags) 514 { 515 if (sk) { 516 const struct inet_sock *inet = inet_sk(sk); 517 518 oif = sk->sk_bound_dev_if; 519 mark = sk->sk_mark; 520 tos = RT_CONN_FLAGS(sk); 521 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 522 } 523 flowi4_init_output(fl4, oif, mark, tos, 524 RT_SCOPE_UNIVERSE, prot, 525 flow_flags, 526 iph->daddr, iph->saddr, 0, 0, 527 sock_net_uid(net, sk)); 528 } 529 530 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 531 const struct sock *sk) 532 { 533 const struct net *net = dev_net(skb->dev); 534 const struct iphdr *iph = ip_hdr(skb); 535 int oif = skb->dev->ifindex; 536 u8 tos = RT_TOS(iph->tos); 537 u8 prot = iph->protocol; 538 u32 mark = skb->mark; 539 540 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 541 } 542 543 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 544 { 545 const struct inet_sock *inet = inet_sk(sk); 546 const struct ip_options_rcu *inet_opt; 547 __be32 daddr = inet->inet_daddr; 548 549 rcu_read_lock(); 550 inet_opt = rcu_dereference(inet->inet_opt); 551 if (inet_opt && inet_opt->opt.srr) 552 daddr = inet_opt->opt.faddr; 553 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 554 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 555 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 556 inet_sk_flowi_flags(sk), 557 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 558 rcu_read_unlock(); 559 } 560 561 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 562 const struct sk_buff *skb) 563 { 564 if (skb) 565 build_skb_flow_key(fl4, skb, sk); 566 else 567 build_sk_flow_key(fl4, sk); 568 } 569 570 static DEFINE_SPINLOCK(fnhe_lock); 571 572 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 573 { 574 struct rtable *rt; 575 576 rt = rcu_dereference(fnhe->fnhe_rth_input); 577 if (rt) { 578 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 579 dst_dev_put(&rt->dst); 580 dst_release(&rt->dst); 581 } 582 rt = rcu_dereference(fnhe->fnhe_rth_output); 583 if (rt) { 584 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 585 dst_dev_put(&rt->dst); 586 dst_release(&rt->dst); 587 } 588 } 589 590 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 591 { 592 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 593 struct fib_nh_exception *fnhe, *oldest = NULL; 594 595 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 596 fnhe = rcu_dereference_protected(*fnhe_p, 597 lockdep_is_held(&fnhe_lock)); 598 if (!fnhe) 599 break; 600 if (!oldest || 601 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 602 oldest = fnhe; 603 oldest_p = fnhe_p; 604 } 605 } 606 fnhe_flush_routes(oldest); 607 *oldest_p = oldest->fnhe_next; 608 kfree_rcu(oldest, rcu); 609 } 610 611 static u32 fnhe_hashfun(__be32 daddr) 612 { 613 static siphash_key_t fnhe_hash_key __read_mostly; 614 u64 hval; 615 616 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 617 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 618 return hash_64(hval, FNHE_HASH_SHIFT); 619 } 620 621 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 622 { 623 rt->rt_pmtu = fnhe->fnhe_pmtu; 624 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 625 rt->dst.expires = fnhe->fnhe_expires; 626 627 if (fnhe->fnhe_gw) { 628 rt->rt_flags |= RTCF_REDIRECTED; 629 rt->rt_uses_gateway = 1; 630 rt->rt_gw_family = AF_INET; 631 rt->rt_gw4 = fnhe->fnhe_gw; 632 } 633 } 634 635 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 636 __be32 gw, u32 pmtu, bool lock, 637 unsigned long expires) 638 { 639 struct fnhe_hash_bucket *hash; 640 struct fib_nh_exception *fnhe; 641 struct rtable *rt; 642 u32 genid, hval; 643 unsigned int i; 644 int depth; 645 646 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 647 hval = fnhe_hashfun(daddr); 648 649 spin_lock_bh(&fnhe_lock); 650 651 hash = rcu_dereference(nhc->nhc_exceptions); 652 if (!hash) { 653 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 654 if (!hash) 655 goto out_unlock; 656 rcu_assign_pointer(nhc->nhc_exceptions, hash); 657 } 658 659 hash += hval; 660 661 depth = 0; 662 for (fnhe = rcu_dereference(hash->chain); fnhe; 663 fnhe = rcu_dereference(fnhe->fnhe_next)) { 664 if (fnhe->fnhe_daddr == daddr) 665 break; 666 depth++; 667 } 668 669 if (fnhe) { 670 if (fnhe->fnhe_genid != genid) 671 fnhe->fnhe_genid = genid; 672 if (gw) 673 fnhe->fnhe_gw = gw; 674 if (pmtu) { 675 fnhe->fnhe_pmtu = pmtu; 676 fnhe->fnhe_mtu_locked = lock; 677 } 678 fnhe->fnhe_expires = max(1UL, expires); 679 /* Update all cached dsts too */ 680 rt = rcu_dereference(fnhe->fnhe_rth_input); 681 if (rt) 682 fill_route_from_fnhe(rt, fnhe); 683 rt = rcu_dereference(fnhe->fnhe_rth_output); 684 if (rt) 685 fill_route_from_fnhe(rt, fnhe); 686 } else { 687 /* Randomize max depth to avoid some side channels attacks. */ 688 int max_depth = FNHE_RECLAIM_DEPTH + 689 prandom_u32_max(FNHE_RECLAIM_DEPTH); 690 691 while (depth > max_depth) { 692 fnhe_remove_oldest(hash); 693 depth--; 694 } 695 696 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 697 if (!fnhe) 698 goto out_unlock; 699 700 fnhe->fnhe_next = hash->chain; 701 702 fnhe->fnhe_genid = genid; 703 fnhe->fnhe_daddr = daddr; 704 fnhe->fnhe_gw = gw; 705 fnhe->fnhe_pmtu = pmtu; 706 fnhe->fnhe_mtu_locked = lock; 707 fnhe->fnhe_expires = max(1UL, expires); 708 709 rcu_assign_pointer(hash->chain, fnhe); 710 711 /* Exception created; mark the cached routes for the nexthop 712 * stale, so anyone caching it rechecks if this exception 713 * applies to them. 714 */ 715 rt = rcu_dereference(nhc->nhc_rth_input); 716 if (rt) 717 rt->dst.obsolete = DST_OBSOLETE_KILL; 718 719 for_each_possible_cpu(i) { 720 struct rtable __rcu **prt; 721 722 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 723 rt = rcu_dereference(*prt); 724 if (rt) 725 rt->dst.obsolete = DST_OBSOLETE_KILL; 726 } 727 } 728 729 fnhe->fnhe_stamp = jiffies; 730 731 out_unlock: 732 spin_unlock_bh(&fnhe_lock); 733 } 734 735 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 736 bool kill_route) 737 { 738 __be32 new_gw = icmp_hdr(skb)->un.gateway; 739 __be32 old_gw = ip_hdr(skb)->saddr; 740 struct net_device *dev = skb->dev; 741 struct in_device *in_dev; 742 struct fib_result res; 743 struct neighbour *n; 744 struct net *net; 745 746 switch (icmp_hdr(skb)->code & 7) { 747 case ICMP_REDIR_NET: 748 case ICMP_REDIR_NETTOS: 749 case ICMP_REDIR_HOST: 750 case ICMP_REDIR_HOSTTOS: 751 break; 752 753 default: 754 return; 755 } 756 757 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 758 return; 759 760 in_dev = __in_dev_get_rcu(dev); 761 if (!in_dev) 762 return; 763 764 net = dev_net(dev); 765 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 766 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 767 ipv4_is_zeronet(new_gw)) 768 goto reject_redirect; 769 770 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 771 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 772 goto reject_redirect; 773 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 774 goto reject_redirect; 775 } else { 776 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 777 goto reject_redirect; 778 } 779 780 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 781 if (!n) 782 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 783 if (!IS_ERR(n)) { 784 if (!(n->nud_state & NUD_VALID)) { 785 neigh_event_send(n, NULL); 786 } else { 787 if (fib_lookup(net, fl4, &res, 0) == 0) { 788 struct fib_nh_common *nhc; 789 790 fib_select_path(net, &res, fl4, skb); 791 nhc = FIB_RES_NHC(res); 792 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 793 0, false, 794 jiffies + ip_rt_gc_timeout); 795 } 796 if (kill_route) 797 rt->dst.obsolete = DST_OBSOLETE_KILL; 798 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 799 } 800 neigh_release(n); 801 } 802 return; 803 804 reject_redirect: 805 #ifdef CONFIG_IP_ROUTE_VERBOSE 806 if (IN_DEV_LOG_MARTIANS(in_dev)) { 807 const struct iphdr *iph = (const struct iphdr *) skb->data; 808 __be32 daddr = iph->daddr; 809 __be32 saddr = iph->saddr; 810 811 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 812 " Advised path = %pI4 -> %pI4\n", 813 &old_gw, dev->name, &new_gw, 814 &saddr, &daddr); 815 } 816 #endif 817 ; 818 } 819 820 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 821 { 822 struct rtable *rt; 823 struct flowi4 fl4; 824 const struct iphdr *iph = (const struct iphdr *) skb->data; 825 struct net *net = dev_net(skb->dev); 826 int oif = skb->dev->ifindex; 827 u8 tos = RT_TOS(iph->tos); 828 u8 prot = iph->protocol; 829 u32 mark = skb->mark; 830 831 rt = (struct rtable *) dst; 832 833 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 834 __ip_do_redirect(rt, skb, &fl4, true); 835 } 836 837 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 838 { 839 struct rtable *rt = (struct rtable *)dst; 840 struct dst_entry *ret = dst; 841 842 if (rt) { 843 if (dst->obsolete > 0) { 844 ip_rt_put(rt); 845 ret = NULL; 846 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 847 rt->dst.expires) { 848 ip_rt_put(rt); 849 ret = NULL; 850 } 851 } 852 return ret; 853 } 854 855 /* 856 * Algorithm: 857 * 1. The first ip_rt_redirect_number redirects are sent 858 * with exponential backoff, then we stop sending them at all, 859 * assuming that the host ignores our redirects. 860 * 2. If we did not see packets requiring redirects 861 * during ip_rt_redirect_silence, we assume that the host 862 * forgot redirected route and start to send redirects again. 863 * 864 * This algorithm is much cheaper and more intelligent than dumb load limiting 865 * in icmp.c. 866 * 867 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 868 * and "frag. need" (breaks PMTU discovery) in icmp.c. 869 */ 870 871 void ip_rt_send_redirect(struct sk_buff *skb) 872 { 873 struct rtable *rt = skb_rtable(skb); 874 struct in_device *in_dev; 875 struct inet_peer *peer; 876 struct net *net; 877 int log_martians; 878 int vif; 879 880 rcu_read_lock(); 881 in_dev = __in_dev_get_rcu(rt->dst.dev); 882 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 883 rcu_read_unlock(); 884 return; 885 } 886 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 887 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 888 rcu_read_unlock(); 889 890 net = dev_net(rt->dst.dev); 891 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 892 if (!peer) { 893 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 894 rt_nexthop(rt, ip_hdr(skb)->daddr)); 895 return; 896 } 897 898 /* No redirected packets during ip_rt_redirect_silence; 899 * reset the algorithm. 900 */ 901 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 902 peer->rate_tokens = 0; 903 peer->n_redirects = 0; 904 } 905 906 /* Too many ignored redirects; do not send anything 907 * set dst.rate_last to the last seen redirected packet. 908 */ 909 if (peer->n_redirects >= ip_rt_redirect_number) { 910 peer->rate_last = jiffies; 911 goto out_put_peer; 912 } 913 914 /* Check for load limit; set rate_last to the latest sent 915 * redirect. 916 */ 917 if (peer->n_redirects == 0 || 918 time_after(jiffies, 919 (peer->rate_last + 920 (ip_rt_redirect_load << peer->n_redirects)))) { 921 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 922 923 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 924 peer->rate_last = jiffies; 925 ++peer->n_redirects; 926 #ifdef CONFIG_IP_ROUTE_VERBOSE 927 if (log_martians && 928 peer->n_redirects == ip_rt_redirect_number) 929 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 930 &ip_hdr(skb)->saddr, inet_iif(skb), 931 &ip_hdr(skb)->daddr, &gw); 932 #endif 933 } 934 out_put_peer: 935 inet_putpeer(peer); 936 } 937 938 static int ip_error(struct sk_buff *skb) 939 { 940 struct rtable *rt = skb_rtable(skb); 941 struct net_device *dev = skb->dev; 942 struct in_device *in_dev; 943 struct inet_peer *peer; 944 unsigned long now; 945 struct net *net; 946 bool send; 947 int code; 948 949 if (netif_is_l3_master(skb->dev)) { 950 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 951 if (!dev) 952 goto out; 953 } 954 955 in_dev = __in_dev_get_rcu(dev); 956 957 /* IP on this device is disabled. */ 958 if (!in_dev) 959 goto out; 960 961 net = dev_net(rt->dst.dev); 962 if (!IN_DEV_FORWARD(in_dev)) { 963 switch (rt->dst.error) { 964 case EHOSTUNREACH: 965 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 966 break; 967 968 case ENETUNREACH: 969 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 970 break; 971 } 972 goto out; 973 } 974 975 switch (rt->dst.error) { 976 case EINVAL: 977 default: 978 goto out; 979 case EHOSTUNREACH: 980 code = ICMP_HOST_UNREACH; 981 break; 982 case ENETUNREACH: 983 code = ICMP_NET_UNREACH; 984 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 985 break; 986 case EACCES: 987 code = ICMP_PKT_FILTERED; 988 break; 989 } 990 991 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 992 l3mdev_master_ifindex(skb->dev), 1); 993 994 send = true; 995 if (peer) { 996 now = jiffies; 997 peer->rate_tokens += now - peer->rate_last; 998 if (peer->rate_tokens > ip_rt_error_burst) 999 peer->rate_tokens = ip_rt_error_burst; 1000 peer->rate_last = now; 1001 if (peer->rate_tokens >= ip_rt_error_cost) 1002 peer->rate_tokens -= ip_rt_error_cost; 1003 else 1004 send = false; 1005 inet_putpeer(peer); 1006 } 1007 if (send) 1008 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1009 1010 out: kfree_skb(skb); 1011 return 0; 1012 } 1013 1014 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1015 { 1016 struct dst_entry *dst = &rt->dst; 1017 struct net *net = dev_net(dst->dev); 1018 struct fib_result res; 1019 bool lock = false; 1020 u32 old_mtu; 1021 1022 if (ip_mtu_locked(dst)) 1023 return; 1024 1025 old_mtu = ipv4_mtu(dst); 1026 if (old_mtu < mtu) 1027 return; 1028 1029 if (mtu < ip_rt_min_pmtu) { 1030 lock = true; 1031 mtu = min(old_mtu, ip_rt_min_pmtu); 1032 } 1033 1034 if (rt->rt_pmtu == mtu && !lock && 1035 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 1036 return; 1037 1038 rcu_read_lock(); 1039 if (fib_lookup(net, fl4, &res, 0) == 0) { 1040 struct fib_nh_common *nhc; 1041 1042 fib_select_path(net, &res, fl4, NULL); 1043 nhc = FIB_RES_NHC(res); 1044 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1045 jiffies + ip_rt_mtu_expires); 1046 } 1047 rcu_read_unlock(); 1048 } 1049 1050 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1051 struct sk_buff *skb, u32 mtu, 1052 bool confirm_neigh) 1053 { 1054 struct rtable *rt = (struct rtable *) dst; 1055 struct flowi4 fl4; 1056 1057 ip_rt_build_flow_key(&fl4, sk, skb); 1058 1059 /* Don't make lookup fail for bridged encapsulations */ 1060 if (skb && netif_is_any_bridge_port(skb->dev)) 1061 fl4.flowi4_oif = 0; 1062 1063 __ip_rt_update_pmtu(rt, &fl4, mtu); 1064 } 1065 1066 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1067 int oif, u8 protocol) 1068 { 1069 const struct iphdr *iph = (const struct iphdr *)skb->data; 1070 struct flowi4 fl4; 1071 struct rtable *rt; 1072 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1073 1074 __build_flow_key(net, &fl4, NULL, iph, oif, 1075 RT_TOS(iph->tos), protocol, mark, 0); 1076 rt = __ip_route_output_key(net, &fl4); 1077 if (!IS_ERR(rt)) { 1078 __ip_rt_update_pmtu(rt, &fl4, mtu); 1079 ip_rt_put(rt); 1080 } 1081 } 1082 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1083 1084 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1085 { 1086 const struct iphdr *iph = (const struct iphdr *)skb->data; 1087 struct flowi4 fl4; 1088 struct rtable *rt; 1089 1090 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1091 1092 if (!fl4.flowi4_mark) 1093 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1094 1095 rt = __ip_route_output_key(sock_net(sk), &fl4); 1096 if (!IS_ERR(rt)) { 1097 __ip_rt_update_pmtu(rt, &fl4, mtu); 1098 ip_rt_put(rt); 1099 } 1100 } 1101 1102 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1103 { 1104 const struct iphdr *iph = (const struct iphdr *)skb->data; 1105 struct flowi4 fl4; 1106 struct rtable *rt; 1107 struct dst_entry *odst = NULL; 1108 bool new = false; 1109 struct net *net = sock_net(sk); 1110 1111 bh_lock_sock(sk); 1112 1113 if (!ip_sk_accept_pmtu(sk)) 1114 goto out; 1115 1116 odst = sk_dst_get(sk); 1117 1118 if (sock_owned_by_user(sk) || !odst) { 1119 __ipv4_sk_update_pmtu(skb, sk, mtu); 1120 goto out; 1121 } 1122 1123 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1124 1125 rt = (struct rtable *)odst; 1126 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1127 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1128 if (IS_ERR(rt)) 1129 goto out; 1130 1131 new = true; 1132 } 1133 1134 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1135 1136 if (!dst_check(&rt->dst, 0)) { 1137 if (new) 1138 dst_release(&rt->dst); 1139 1140 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1141 if (IS_ERR(rt)) 1142 goto out; 1143 1144 new = true; 1145 } 1146 1147 if (new) 1148 sk_dst_set(sk, &rt->dst); 1149 1150 out: 1151 bh_unlock_sock(sk); 1152 dst_release(odst); 1153 } 1154 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1155 1156 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1157 int oif, u8 protocol) 1158 { 1159 const struct iphdr *iph = (const struct iphdr *)skb->data; 1160 struct flowi4 fl4; 1161 struct rtable *rt; 1162 1163 __build_flow_key(net, &fl4, NULL, iph, oif, 1164 RT_TOS(iph->tos), protocol, 0, 0); 1165 rt = __ip_route_output_key(net, &fl4); 1166 if (!IS_ERR(rt)) { 1167 __ip_do_redirect(rt, skb, &fl4, false); 1168 ip_rt_put(rt); 1169 } 1170 } 1171 EXPORT_SYMBOL_GPL(ipv4_redirect); 1172 1173 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1174 { 1175 const struct iphdr *iph = (const struct iphdr *)skb->data; 1176 struct flowi4 fl4; 1177 struct rtable *rt; 1178 struct net *net = sock_net(sk); 1179 1180 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1181 rt = __ip_route_output_key(net, &fl4); 1182 if (!IS_ERR(rt)) { 1183 __ip_do_redirect(rt, skb, &fl4, false); 1184 ip_rt_put(rt); 1185 } 1186 } 1187 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1188 1189 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1190 u32 cookie) 1191 { 1192 struct rtable *rt = (struct rtable *) dst; 1193 1194 /* All IPV4 dsts are created with ->obsolete set to the value 1195 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1196 * into this function always. 1197 * 1198 * When a PMTU/redirect information update invalidates a route, 1199 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1200 * DST_OBSOLETE_DEAD. 1201 */ 1202 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1203 return NULL; 1204 return dst; 1205 } 1206 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1207 1208 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1209 { 1210 struct ip_options opt; 1211 int res; 1212 1213 /* Recompile ip options since IPCB may not be valid anymore. 1214 * Also check we have a reasonable ipv4 header. 1215 */ 1216 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1217 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1218 return; 1219 1220 memset(&opt, 0, sizeof(opt)); 1221 if (ip_hdr(skb)->ihl > 5) { 1222 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1223 return; 1224 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1225 1226 rcu_read_lock(); 1227 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1228 rcu_read_unlock(); 1229 1230 if (res) 1231 return; 1232 } 1233 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1234 } 1235 1236 static void ipv4_link_failure(struct sk_buff *skb) 1237 { 1238 struct rtable *rt; 1239 1240 ipv4_send_dest_unreach(skb); 1241 1242 rt = skb_rtable(skb); 1243 if (rt) 1244 dst_set_expires(&rt->dst, 0); 1245 } 1246 1247 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1248 { 1249 pr_debug("%s: %pI4 -> %pI4, %s\n", 1250 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1251 skb->dev ? skb->dev->name : "?"); 1252 kfree_skb(skb); 1253 WARN_ON(1); 1254 return 0; 1255 } 1256 1257 /* 1258 * We do not cache source address of outgoing interface, 1259 * because it is used only by IP RR, TS and SRR options, 1260 * so that it out of fast path. 1261 * 1262 * BTW remember: "addr" is allowed to be not aligned 1263 * in IP options! 1264 */ 1265 1266 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1267 { 1268 __be32 src; 1269 1270 if (rt_is_output_route(rt)) 1271 src = ip_hdr(skb)->saddr; 1272 else { 1273 struct fib_result res; 1274 struct iphdr *iph = ip_hdr(skb); 1275 struct flowi4 fl4 = { 1276 .daddr = iph->daddr, 1277 .saddr = iph->saddr, 1278 .flowi4_tos = RT_TOS(iph->tos), 1279 .flowi4_oif = rt->dst.dev->ifindex, 1280 .flowi4_iif = skb->dev->ifindex, 1281 .flowi4_mark = skb->mark, 1282 }; 1283 1284 rcu_read_lock(); 1285 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1286 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1287 else 1288 src = inet_select_addr(rt->dst.dev, 1289 rt_nexthop(rt, iph->daddr), 1290 RT_SCOPE_UNIVERSE); 1291 rcu_read_unlock(); 1292 } 1293 memcpy(addr, &src, 4); 1294 } 1295 1296 #ifdef CONFIG_IP_ROUTE_CLASSID 1297 static void set_class_tag(struct rtable *rt, u32 tag) 1298 { 1299 if (!(rt->dst.tclassid & 0xFFFF)) 1300 rt->dst.tclassid |= tag & 0xFFFF; 1301 if (!(rt->dst.tclassid & 0xFFFF0000)) 1302 rt->dst.tclassid |= tag & 0xFFFF0000; 1303 } 1304 #endif 1305 1306 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1307 { 1308 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1309 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1310 ip_rt_min_advmss); 1311 1312 return min(advmss, IPV4_MAX_PMTU - header_size); 1313 } 1314 1315 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1316 { 1317 return ip_dst_mtu_maybe_forward(dst, false); 1318 } 1319 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1320 1321 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1322 { 1323 struct fnhe_hash_bucket *hash; 1324 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1325 u32 hval = fnhe_hashfun(daddr); 1326 1327 spin_lock_bh(&fnhe_lock); 1328 1329 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1330 lockdep_is_held(&fnhe_lock)); 1331 hash += hval; 1332 1333 fnhe_p = &hash->chain; 1334 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1335 while (fnhe) { 1336 if (fnhe->fnhe_daddr == daddr) { 1337 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1338 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1339 /* set fnhe_daddr to 0 to ensure it won't bind with 1340 * new dsts in rt_bind_exception(). 1341 */ 1342 fnhe->fnhe_daddr = 0; 1343 fnhe_flush_routes(fnhe); 1344 kfree_rcu(fnhe, rcu); 1345 break; 1346 } 1347 fnhe_p = &fnhe->fnhe_next; 1348 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1349 lockdep_is_held(&fnhe_lock)); 1350 } 1351 1352 spin_unlock_bh(&fnhe_lock); 1353 } 1354 1355 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1356 __be32 daddr) 1357 { 1358 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1359 struct fib_nh_exception *fnhe; 1360 u32 hval; 1361 1362 if (!hash) 1363 return NULL; 1364 1365 hval = fnhe_hashfun(daddr); 1366 1367 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1368 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1369 if (fnhe->fnhe_daddr == daddr) { 1370 if (fnhe->fnhe_expires && 1371 time_after(jiffies, fnhe->fnhe_expires)) { 1372 ip_del_fnhe(nhc, daddr); 1373 break; 1374 } 1375 return fnhe; 1376 } 1377 } 1378 return NULL; 1379 } 1380 1381 /* MTU selection: 1382 * 1. mtu on route is locked - use it 1383 * 2. mtu from nexthop exception 1384 * 3. mtu from egress device 1385 */ 1386 1387 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1388 { 1389 struct fib_nh_common *nhc = res->nhc; 1390 struct net_device *dev = nhc->nhc_dev; 1391 struct fib_info *fi = res->fi; 1392 u32 mtu = 0; 1393 1394 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1395 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1396 mtu = fi->fib_mtu; 1397 1398 if (likely(!mtu)) { 1399 struct fib_nh_exception *fnhe; 1400 1401 fnhe = find_exception(nhc, daddr); 1402 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1403 mtu = fnhe->fnhe_pmtu; 1404 } 1405 1406 if (likely(!mtu)) 1407 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1408 1409 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1410 } 1411 1412 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1413 __be32 daddr, const bool do_cache) 1414 { 1415 bool ret = false; 1416 1417 spin_lock_bh(&fnhe_lock); 1418 1419 if (daddr == fnhe->fnhe_daddr) { 1420 struct rtable __rcu **porig; 1421 struct rtable *orig; 1422 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1423 1424 if (rt_is_input_route(rt)) 1425 porig = &fnhe->fnhe_rth_input; 1426 else 1427 porig = &fnhe->fnhe_rth_output; 1428 orig = rcu_dereference(*porig); 1429 1430 if (fnhe->fnhe_genid != genid) { 1431 fnhe->fnhe_genid = genid; 1432 fnhe->fnhe_gw = 0; 1433 fnhe->fnhe_pmtu = 0; 1434 fnhe->fnhe_expires = 0; 1435 fnhe->fnhe_mtu_locked = false; 1436 fnhe_flush_routes(fnhe); 1437 orig = NULL; 1438 } 1439 fill_route_from_fnhe(rt, fnhe); 1440 if (!rt->rt_gw4) { 1441 rt->rt_gw4 = daddr; 1442 rt->rt_gw_family = AF_INET; 1443 } 1444 1445 if (do_cache) { 1446 dst_hold(&rt->dst); 1447 rcu_assign_pointer(*porig, rt); 1448 if (orig) { 1449 dst_dev_put(&orig->dst); 1450 dst_release(&orig->dst); 1451 } 1452 ret = true; 1453 } 1454 1455 fnhe->fnhe_stamp = jiffies; 1456 } 1457 spin_unlock_bh(&fnhe_lock); 1458 1459 return ret; 1460 } 1461 1462 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1463 { 1464 struct rtable *orig, *prev, **p; 1465 bool ret = true; 1466 1467 if (rt_is_input_route(rt)) { 1468 p = (struct rtable **)&nhc->nhc_rth_input; 1469 } else { 1470 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1471 } 1472 orig = *p; 1473 1474 /* hold dst before doing cmpxchg() to avoid race condition 1475 * on this dst 1476 */ 1477 dst_hold(&rt->dst); 1478 prev = cmpxchg(p, orig, rt); 1479 if (prev == orig) { 1480 if (orig) { 1481 rt_add_uncached_list(orig); 1482 dst_release(&orig->dst); 1483 } 1484 } else { 1485 dst_release(&rt->dst); 1486 ret = false; 1487 } 1488 1489 return ret; 1490 } 1491 1492 struct uncached_list { 1493 spinlock_t lock; 1494 struct list_head head; 1495 }; 1496 1497 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1498 1499 void rt_add_uncached_list(struct rtable *rt) 1500 { 1501 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1502 1503 rt->rt_uncached_list = ul; 1504 1505 spin_lock_bh(&ul->lock); 1506 list_add_tail(&rt->rt_uncached, &ul->head); 1507 spin_unlock_bh(&ul->lock); 1508 } 1509 1510 void rt_del_uncached_list(struct rtable *rt) 1511 { 1512 if (!list_empty(&rt->rt_uncached)) { 1513 struct uncached_list *ul = rt->rt_uncached_list; 1514 1515 spin_lock_bh(&ul->lock); 1516 list_del(&rt->rt_uncached); 1517 spin_unlock_bh(&ul->lock); 1518 } 1519 } 1520 1521 static void ipv4_dst_destroy(struct dst_entry *dst) 1522 { 1523 struct rtable *rt = (struct rtable *)dst; 1524 1525 ip_dst_metrics_put(dst); 1526 rt_del_uncached_list(rt); 1527 } 1528 1529 void rt_flush_dev(struct net_device *dev) 1530 { 1531 struct rtable *rt; 1532 int cpu; 1533 1534 for_each_possible_cpu(cpu) { 1535 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1536 1537 spin_lock_bh(&ul->lock); 1538 list_for_each_entry(rt, &ul->head, rt_uncached) { 1539 if (rt->dst.dev != dev) 1540 continue; 1541 rt->dst.dev = blackhole_netdev; 1542 dev_hold(rt->dst.dev); 1543 dev_put(dev); 1544 } 1545 spin_unlock_bh(&ul->lock); 1546 } 1547 } 1548 1549 static bool rt_cache_valid(const struct rtable *rt) 1550 { 1551 return rt && 1552 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1553 !rt_is_expired(rt); 1554 } 1555 1556 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1557 const struct fib_result *res, 1558 struct fib_nh_exception *fnhe, 1559 struct fib_info *fi, u16 type, u32 itag, 1560 const bool do_cache) 1561 { 1562 bool cached = false; 1563 1564 if (fi) { 1565 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1566 1567 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1568 rt->rt_uses_gateway = 1; 1569 rt->rt_gw_family = nhc->nhc_gw_family; 1570 /* only INET and INET6 are supported */ 1571 if (likely(nhc->nhc_gw_family == AF_INET)) 1572 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1573 else 1574 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1575 } 1576 1577 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1578 1579 #ifdef CONFIG_IP_ROUTE_CLASSID 1580 if (nhc->nhc_family == AF_INET) { 1581 struct fib_nh *nh; 1582 1583 nh = container_of(nhc, struct fib_nh, nh_common); 1584 rt->dst.tclassid = nh->nh_tclassid; 1585 } 1586 #endif 1587 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1588 if (unlikely(fnhe)) 1589 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1590 else if (do_cache) 1591 cached = rt_cache_route(nhc, rt); 1592 if (unlikely(!cached)) { 1593 /* Routes we intend to cache in nexthop exception or 1594 * FIB nexthop have the DST_NOCACHE bit clear. 1595 * However, if we are unsuccessful at storing this 1596 * route into the cache we really need to set it. 1597 */ 1598 if (!rt->rt_gw4) { 1599 rt->rt_gw_family = AF_INET; 1600 rt->rt_gw4 = daddr; 1601 } 1602 rt_add_uncached_list(rt); 1603 } 1604 } else 1605 rt_add_uncached_list(rt); 1606 1607 #ifdef CONFIG_IP_ROUTE_CLASSID 1608 #ifdef CONFIG_IP_MULTIPLE_TABLES 1609 set_class_tag(rt, res->tclassid); 1610 #endif 1611 set_class_tag(rt, itag); 1612 #endif 1613 } 1614 1615 struct rtable *rt_dst_alloc(struct net_device *dev, 1616 unsigned int flags, u16 type, 1617 bool nopolicy, bool noxfrm) 1618 { 1619 struct rtable *rt; 1620 1621 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1622 (nopolicy ? DST_NOPOLICY : 0) | 1623 (noxfrm ? DST_NOXFRM : 0)); 1624 1625 if (rt) { 1626 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1627 rt->rt_flags = flags; 1628 rt->rt_type = type; 1629 rt->rt_is_input = 0; 1630 rt->rt_iif = 0; 1631 rt->rt_pmtu = 0; 1632 rt->rt_mtu_locked = 0; 1633 rt->rt_uses_gateway = 0; 1634 rt->rt_gw_family = 0; 1635 rt->rt_gw4 = 0; 1636 INIT_LIST_HEAD(&rt->rt_uncached); 1637 1638 rt->dst.output = ip_output; 1639 if (flags & RTCF_LOCAL) 1640 rt->dst.input = ip_local_deliver; 1641 } 1642 1643 return rt; 1644 } 1645 EXPORT_SYMBOL(rt_dst_alloc); 1646 1647 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1648 { 1649 struct rtable *new_rt; 1650 1651 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1652 rt->dst.flags); 1653 1654 if (new_rt) { 1655 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1656 new_rt->rt_flags = rt->rt_flags; 1657 new_rt->rt_type = rt->rt_type; 1658 new_rt->rt_is_input = rt->rt_is_input; 1659 new_rt->rt_iif = rt->rt_iif; 1660 new_rt->rt_pmtu = rt->rt_pmtu; 1661 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1662 new_rt->rt_gw_family = rt->rt_gw_family; 1663 if (rt->rt_gw_family == AF_INET) 1664 new_rt->rt_gw4 = rt->rt_gw4; 1665 else if (rt->rt_gw_family == AF_INET6) 1666 new_rt->rt_gw6 = rt->rt_gw6; 1667 INIT_LIST_HEAD(&new_rt->rt_uncached); 1668 1669 new_rt->dst.input = rt->dst.input; 1670 new_rt->dst.output = rt->dst.output; 1671 new_rt->dst.error = rt->dst.error; 1672 new_rt->dst.lastuse = jiffies; 1673 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1674 } 1675 return new_rt; 1676 } 1677 EXPORT_SYMBOL(rt_dst_clone); 1678 1679 /* called in rcu_read_lock() section */ 1680 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1681 u8 tos, struct net_device *dev, 1682 struct in_device *in_dev, u32 *itag) 1683 { 1684 int err; 1685 1686 /* Primary sanity checks. */ 1687 if (!in_dev) 1688 return -EINVAL; 1689 1690 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1691 skb->protocol != htons(ETH_P_IP)) 1692 return -EINVAL; 1693 1694 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1695 return -EINVAL; 1696 1697 if (ipv4_is_zeronet(saddr)) { 1698 if (!ipv4_is_local_multicast(daddr) && 1699 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1700 return -EINVAL; 1701 } else { 1702 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1703 in_dev, itag); 1704 if (err < 0) 1705 return err; 1706 } 1707 return 0; 1708 } 1709 1710 /* called in rcu_read_lock() section */ 1711 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1712 u8 tos, struct net_device *dev, int our) 1713 { 1714 struct in_device *in_dev = __in_dev_get_rcu(dev); 1715 unsigned int flags = RTCF_MULTICAST; 1716 struct rtable *rth; 1717 u32 itag = 0; 1718 int err; 1719 1720 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1721 if (err) 1722 return err; 1723 1724 if (our) 1725 flags |= RTCF_LOCAL; 1726 1727 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1728 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 1729 if (!rth) 1730 return -ENOBUFS; 1731 1732 #ifdef CONFIG_IP_ROUTE_CLASSID 1733 rth->dst.tclassid = itag; 1734 #endif 1735 rth->dst.output = ip_rt_bug; 1736 rth->rt_is_input= 1; 1737 1738 #ifdef CONFIG_IP_MROUTE 1739 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1740 rth->dst.input = ip_mr_input; 1741 #endif 1742 RT_CACHE_STAT_INC(in_slow_mc); 1743 1744 skb_dst_set(skb, &rth->dst); 1745 return 0; 1746 } 1747 1748 1749 static void ip_handle_martian_source(struct net_device *dev, 1750 struct in_device *in_dev, 1751 struct sk_buff *skb, 1752 __be32 daddr, 1753 __be32 saddr) 1754 { 1755 RT_CACHE_STAT_INC(in_martian_src); 1756 #ifdef CONFIG_IP_ROUTE_VERBOSE 1757 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1758 /* 1759 * RFC1812 recommendation, if source is martian, 1760 * the only hint is MAC header. 1761 */ 1762 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1763 &daddr, &saddr, dev->name); 1764 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1765 print_hex_dump(KERN_WARNING, "ll header: ", 1766 DUMP_PREFIX_OFFSET, 16, 1, 1767 skb_mac_header(skb), 1768 dev->hard_header_len, false); 1769 } 1770 } 1771 #endif 1772 } 1773 1774 /* called in rcu_read_lock() section */ 1775 static int __mkroute_input(struct sk_buff *skb, 1776 const struct fib_result *res, 1777 struct in_device *in_dev, 1778 __be32 daddr, __be32 saddr, u32 tos) 1779 { 1780 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1781 struct net_device *dev = nhc->nhc_dev; 1782 struct fib_nh_exception *fnhe; 1783 struct rtable *rth; 1784 int err; 1785 struct in_device *out_dev; 1786 bool do_cache; 1787 u32 itag = 0; 1788 1789 /* get a working reference to the output device */ 1790 out_dev = __in_dev_get_rcu(dev); 1791 if (!out_dev) { 1792 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1793 return -EINVAL; 1794 } 1795 1796 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1797 in_dev->dev, in_dev, &itag); 1798 if (err < 0) { 1799 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1800 saddr); 1801 1802 goto cleanup; 1803 } 1804 1805 do_cache = res->fi && !itag; 1806 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1807 skb->protocol == htons(ETH_P_IP)) { 1808 __be32 gw; 1809 1810 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1811 if (IN_DEV_SHARED_MEDIA(out_dev) || 1812 inet_addr_onlink(out_dev, saddr, gw)) 1813 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1814 } 1815 1816 if (skb->protocol != htons(ETH_P_IP)) { 1817 /* Not IP (i.e. ARP). Do not create route, if it is 1818 * invalid for proxy arp. DNAT routes are always valid. 1819 * 1820 * Proxy arp feature have been extended to allow, ARP 1821 * replies back to the same interface, to support 1822 * Private VLAN switch technologies. See arp.c. 1823 */ 1824 if (out_dev == in_dev && 1825 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1826 err = -EINVAL; 1827 goto cleanup; 1828 } 1829 } 1830 1831 fnhe = find_exception(nhc, daddr); 1832 if (do_cache) { 1833 if (fnhe) 1834 rth = rcu_dereference(fnhe->fnhe_rth_input); 1835 else 1836 rth = rcu_dereference(nhc->nhc_rth_input); 1837 if (rt_cache_valid(rth)) { 1838 skb_dst_set_noref(skb, &rth->dst); 1839 goto out; 1840 } 1841 } 1842 1843 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1844 IN_DEV_ORCONF(in_dev, NOPOLICY), 1845 IN_DEV_ORCONF(out_dev, NOXFRM)); 1846 if (!rth) { 1847 err = -ENOBUFS; 1848 goto cleanup; 1849 } 1850 1851 rth->rt_is_input = 1; 1852 RT_CACHE_STAT_INC(in_slow_tot); 1853 1854 rth->dst.input = ip_forward; 1855 1856 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1857 do_cache); 1858 lwtunnel_set_redirect(&rth->dst); 1859 skb_dst_set(skb, &rth->dst); 1860 out: 1861 err = 0; 1862 cleanup: 1863 return err; 1864 } 1865 1866 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1867 /* To make ICMP packets follow the right flow, the multipath hash is 1868 * calculated from the inner IP addresses. 1869 */ 1870 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1871 struct flow_keys *hash_keys) 1872 { 1873 const struct iphdr *outer_iph = ip_hdr(skb); 1874 const struct iphdr *key_iph = outer_iph; 1875 const struct iphdr *inner_iph; 1876 const struct icmphdr *icmph; 1877 struct iphdr _inner_iph; 1878 struct icmphdr _icmph; 1879 1880 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1881 goto out; 1882 1883 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1884 goto out; 1885 1886 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1887 &_icmph); 1888 if (!icmph) 1889 goto out; 1890 1891 if (!icmp_is_err(icmph->type)) 1892 goto out; 1893 1894 inner_iph = skb_header_pointer(skb, 1895 outer_iph->ihl * 4 + sizeof(_icmph), 1896 sizeof(_inner_iph), &_inner_iph); 1897 if (!inner_iph) 1898 goto out; 1899 1900 key_iph = inner_iph; 1901 out: 1902 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1903 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1904 } 1905 1906 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1907 const struct sk_buff *skb, 1908 bool *p_has_inner) 1909 { 1910 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1911 struct flow_keys keys, hash_keys; 1912 1913 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1914 return 0; 1915 1916 memset(&hash_keys, 0, sizeof(hash_keys)); 1917 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1918 1919 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1920 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1921 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1922 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1923 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1924 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1925 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1926 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1927 hash_keys.ports.src = keys.ports.src; 1928 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1929 hash_keys.ports.dst = keys.ports.dst; 1930 1931 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1932 return flow_hash_from_keys(&hash_keys); 1933 } 1934 1935 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1936 const struct sk_buff *skb, 1937 bool has_inner) 1938 { 1939 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1940 struct flow_keys keys, hash_keys; 1941 1942 /* We assume the packet carries an encapsulation, but if none was 1943 * encountered during dissection of the outer flow, then there is no 1944 * point in calling the flow dissector again. 1945 */ 1946 if (!has_inner) 1947 return 0; 1948 1949 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1950 return 0; 1951 1952 memset(&hash_keys, 0, sizeof(hash_keys)); 1953 skb_flow_dissect_flow_keys(skb, &keys, 0); 1954 1955 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1956 return 0; 1957 1958 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1959 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1960 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1961 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1962 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1963 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1964 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1965 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1966 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1967 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1968 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1969 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1970 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1971 hash_keys.tags.flow_label = keys.tags.flow_label; 1972 } 1973 1974 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1975 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1976 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1977 hash_keys.ports.src = keys.ports.src; 1978 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1979 hash_keys.ports.dst = keys.ports.dst; 1980 1981 return flow_hash_from_keys(&hash_keys); 1982 } 1983 1984 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1985 const struct sk_buff *skb) 1986 { 1987 u32 mhash, mhash_inner; 1988 bool has_inner = true; 1989 1990 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 1991 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 1992 1993 return jhash_2words(mhash, mhash_inner, 0); 1994 } 1995 1996 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 1997 const struct flowi4 *fl4) 1998 { 1999 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 2000 struct flow_keys hash_keys; 2001 2002 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2003 return 0; 2004 2005 memset(&hash_keys, 0, sizeof(hash_keys)); 2006 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2007 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2008 hash_keys.addrs.v4addrs.src = fl4->saddr; 2009 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2010 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2011 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2012 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2013 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2014 hash_keys.ports.src = fl4->fl4_sport; 2015 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2016 hash_keys.ports.dst = fl4->fl4_dport; 2017 2018 return flow_hash_from_keys(&hash_keys); 2019 } 2020 2021 /* if skb is set it will be used and fl4 can be NULL */ 2022 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2023 const struct sk_buff *skb, struct flow_keys *flkeys) 2024 { 2025 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2026 struct flow_keys hash_keys; 2027 u32 mhash = 0; 2028 2029 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2030 case 0: 2031 memset(&hash_keys, 0, sizeof(hash_keys)); 2032 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2033 if (skb) { 2034 ip_multipath_l3_keys(skb, &hash_keys); 2035 } else { 2036 hash_keys.addrs.v4addrs.src = fl4->saddr; 2037 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2038 } 2039 mhash = flow_hash_from_keys(&hash_keys); 2040 break; 2041 case 1: 2042 /* skb is currently provided only when forwarding */ 2043 if (skb) { 2044 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2045 struct flow_keys keys; 2046 2047 /* short-circuit if we already have L4 hash present */ 2048 if (skb->l4_hash) 2049 return skb_get_hash_raw(skb) >> 1; 2050 2051 memset(&hash_keys, 0, sizeof(hash_keys)); 2052 2053 if (!flkeys) { 2054 skb_flow_dissect_flow_keys(skb, &keys, flag); 2055 flkeys = &keys; 2056 } 2057 2058 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2059 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2060 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2061 hash_keys.ports.src = flkeys->ports.src; 2062 hash_keys.ports.dst = flkeys->ports.dst; 2063 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2064 } else { 2065 memset(&hash_keys, 0, sizeof(hash_keys)); 2066 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2067 hash_keys.addrs.v4addrs.src = fl4->saddr; 2068 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2069 hash_keys.ports.src = fl4->fl4_sport; 2070 hash_keys.ports.dst = fl4->fl4_dport; 2071 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2072 } 2073 mhash = flow_hash_from_keys(&hash_keys); 2074 break; 2075 case 2: 2076 memset(&hash_keys, 0, sizeof(hash_keys)); 2077 /* skb is currently provided only when forwarding */ 2078 if (skb) { 2079 struct flow_keys keys; 2080 2081 skb_flow_dissect_flow_keys(skb, &keys, 0); 2082 /* Inner can be v4 or v6 */ 2083 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2084 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2085 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2086 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2087 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2088 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2089 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2090 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2091 hash_keys.tags.flow_label = keys.tags.flow_label; 2092 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2093 } else { 2094 /* Same as case 0 */ 2095 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2096 ip_multipath_l3_keys(skb, &hash_keys); 2097 } 2098 } else { 2099 /* Same as case 0 */ 2100 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2101 hash_keys.addrs.v4addrs.src = fl4->saddr; 2102 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2103 } 2104 mhash = flow_hash_from_keys(&hash_keys); 2105 break; 2106 case 3: 2107 if (skb) 2108 mhash = fib_multipath_custom_hash_skb(net, skb); 2109 else 2110 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2111 break; 2112 } 2113 2114 if (multipath_hash) 2115 mhash = jhash_2words(mhash, multipath_hash, 0); 2116 2117 return mhash >> 1; 2118 } 2119 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2120 2121 static int ip_mkroute_input(struct sk_buff *skb, 2122 struct fib_result *res, 2123 struct in_device *in_dev, 2124 __be32 daddr, __be32 saddr, u32 tos, 2125 struct flow_keys *hkeys) 2126 { 2127 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2128 if (res->fi && fib_info_num_path(res->fi) > 1) { 2129 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2130 2131 fib_select_multipath(res, h); 2132 } 2133 #endif 2134 2135 /* create a routing cache entry */ 2136 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2137 } 2138 2139 /* Implements all the saddr-related checks as ip_route_input_slow(), 2140 * assuming daddr is valid and the destination is not a local broadcast one. 2141 * Uses the provided hint instead of performing a route lookup. 2142 */ 2143 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2144 u8 tos, struct net_device *dev, 2145 const struct sk_buff *hint) 2146 { 2147 struct in_device *in_dev = __in_dev_get_rcu(dev); 2148 struct rtable *rt = skb_rtable(hint); 2149 struct net *net = dev_net(dev); 2150 int err = -EINVAL; 2151 u32 tag = 0; 2152 2153 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2154 goto martian_source; 2155 2156 if (ipv4_is_zeronet(saddr)) 2157 goto martian_source; 2158 2159 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2160 goto martian_source; 2161 2162 if (rt->rt_type != RTN_LOCAL) 2163 goto skip_validate_source; 2164 2165 tos &= IPTOS_RT_MASK; 2166 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2167 if (err < 0) 2168 goto martian_source; 2169 2170 skip_validate_source: 2171 skb_dst_copy(skb, hint); 2172 return 0; 2173 2174 martian_source: 2175 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2176 return err; 2177 } 2178 2179 /* get device for dst_alloc with local routes */ 2180 static struct net_device *ip_rt_get_dev(struct net *net, 2181 const struct fib_result *res) 2182 { 2183 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2184 struct net_device *dev = NULL; 2185 2186 if (nhc) 2187 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2188 2189 return dev ? : net->loopback_dev; 2190 } 2191 2192 /* 2193 * NOTE. We drop all the packets that has local source 2194 * addresses, because every properly looped back packet 2195 * must have correct destination already attached by output routine. 2196 * Changes in the enforced policies must be applied also to 2197 * ip_route_use_hint(). 2198 * 2199 * Such approach solves two big problems: 2200 * 1. Not simplex devices are handled properly. 2201 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2202 * called with rcu_read_lock() 2203 */ 2204 2205 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2206 u8 tos, struct net_device *dev, 2207 struct fib_result *res) 2208 { 2209 struct in_device *in_dev = __in_dev_get_rcu(dev); 2210 struct flow_keys *flkeys = NULL, _flkeys; 2211 struct net *net = dev_net(dev); 2212 struct ip_tunnel_info *tun_info; 2213 int err = -EINVAL; 2214 unsigned int flags = 0; 2215 u32 itag = 0; 2216 struct rtable *rth; 2217 struct flowi4 fl4; 2218 bool do_cache = true; 2219 2220 /* IP on this device is disabled. */ 2221 2222 if (!in_dev) 2223 goto out; 2224 2225 /* Check for the most weird martians, which can be not detected 2226 * by fib_lookup. 2227 */ 2228 2229 tun_info = skb_tunnel_info(skb); 2230 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2231 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2232 else 2233 fl4.flowi4_tun_key.tun_id = 0; 2234 skb_dst_drop(skb); 2235 2236 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2237 goto martian_source; 2238 2239 res->fi = NULL; 2240 res->table = NULL; 2241 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2242 goto brd_input; 2243 2244 /* Accept zero addresses only to limited broadcast; 2245 * I even do not know to fix it or not. Waiting for complains :-) 2246 */ 2247 if (ipv4_is_zeronet(saddr)) 2248 goto martian_source; 2249 2250 if (ipv4_is_zeronet(daddr)) 2251 goto martian_destination; 2252 2253 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2254 * and call it once if daddr or/and saddr are loopback addresses 2255 */ 2256 if (ipv4_is_loopback(daddr)) { 2257 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2258 goto martian_destination; 2259 } else if (ipv4_is_loopback(saddr)) { 2260 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2261 goto martian_source; 2262 } 2263 2264 /* 2265 * Now we are ready to route packet. 2266 */ 2267 fl4.flowi4_oif = 0; 2268 fl4.flowi4_iif = dev->ifindex; 2269 fl4.flowi4_mark = skb->mark; 2270 fl4.flowi4_tos = tos; 2271 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2272 fl4.flowi4_flags = 0; 2273 fl4.daddr = daddr; 2274 fl4.saddr = saddr; 2275 fl4.flowi4_uid = sock_net_uid(net, NULL); 2276 fl4.flowi4_multipath_hash = 0; 2277 2278 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2279 flkeys = &_flkeys; 2280 } else { 2281 fl4.flowi4_proto = 0; 2282 fl4.fl4_sport = 0; 2283 fl4.fl4_dport = 0; 2284 } 2285 2286 err = fib_lookup(net, &fl4, res, 0); 2287 if (err != 0) { 2288 if (!IN_DEV_FORWARD(in_dev)) 2289 err = -EHOSTUNREACH; 2290 goto no_route; 2291 } 2292 2293 if (res->type == RTN_BROADCAST) { 2294 if (IN_DEV_BFORWARD(in_dev)) 2295 goto make_route; 2296 /* not do cache if bc_forwarding is enabled */ 2297 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2298 do_cache = false; 2299 goto brd_input; 2300 } 2301 2302 if (res->type == RTN_LOCAL) { 2303 err = fib_validate_source(skb, saddr, daddr, tos, 2304 0, dev, in_dev, &itag); 2305 if (err < 0) 2306 goto martian_source; 2307 goto local_input; 2308 } 2309 2310 if (!IN_DEV_FORWARD(in_dev)) { 2311 err = -EHOSTUNREACH; 2312 goto no_route; 2313 } 2314 if (res->type != RTN_UNICAST) 2315 goto martian_destination; 2316 2317 make_route: 2318 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2319 out: return err; 2320 2321 brd_input: 2322 if (skb->protocol != htons(ETH_P_IP)) 2323 goto e_inval; 2324 2325 if (!ipv4_is_zeronet(saddr)) { 2326 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2327 in_dev, &itag); 2328 if (err < 0) 2329 goto martian_source; 2330 } 2331 flags |= RTCF_BROADCAST; 2332 res->type = RTN_BROADCAST; 2333 RT_CACHE_STAT_INC(in_brd); 2334 2335 local_input: 2336 do_cache &= res->fi && !itag; 2337 if (do_cache) { 2338 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2339 2340 rth = rcu_dereference(nhc->nhc_rth_input); 2341 if (rt_cache_valid(rth)) { 2342 skb_dst_set_noref(skb, &rth->dst); 2343 err = 0; 2344 goto out; 2345 } 2346 } 2347 2348 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2349 flags | RTCF_LOCAL, res->type, 2350 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 2351 if (!rth) 2352 goto e_nobufs; 2353 2354 rth->dst.output= ip_rt_bug; 2355 #ifdef CONFIG_IP_ROUTE_CLASSID 2356 rth->dst.tclassid = itag; 2357 #endif 2358 rth->rt_is_input = 1; 2359 2360 RT_CACHE_STAT_INC(in_slow_tot); 2361 if (res->type == RTN_UNREACHABLE) { 2362 rth->dst.input= ip_error; 2363 rth->dst.error= -err; 2364 rth->rt_flags &= ~RTCF_LOCAL; 2365 } 2366 2367 if (do_cache) { 2368 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2369 2370 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2371 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2372 WARN_ON(rth->dst.input == lwtunnel_input); 2373 rth->dst.lwtstate->orig_input = rth->dst.input; 2374 rth->dst.input = lwtunnel_input; 2375 } 2376 2377 if (unlikely(!rt_cache_route(nhc, rth))) 2378 rt_add_uncached_list(rth); 2379 } 2380 skb_dst_set(skb, &rth->dst); 2381 err = 0; 2382 goto out; 2383 2384 no_route: 2385 RT_CACHE_STAT_INC(in_no_route); 2386 res->type = RTN_UNREACHABLE; 2387 res->fi = NULL; 2388 res->table = NULL; 2389 goto local_input; 2390 2391 /* 2392 * Do not cache martian addresses: they should be logged (RFC1812) 2393 */ 2394 martian_destination: 2395 RT_CACHE_STAT_INC(in_martian_dst); 2396 #ifdef CONFIG_IP_ROUTE_VERBOSE 2397 if (IN_DEV_LOG_MARTIANS(in_dev)) 2398 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2399 &daddr, &saddr, dev->name); 2400 #endif 2401 2402 e_inval: 2403 err = -EINVAL; 2404 goto out; 2405 2406 e_nobufs: 2407 err = -ENOBUFS; 2408 goto out; 2409 2410 martian_source: 2411 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2412 goto out; 2413 } 2414 2415 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2416 u8 tos, struct net_device *dev) 2417 { 2418 struct fib_result res; 2419 int err; 2420 2421 tos &= IPTOS_RT_MASK; 2422 rcu_read_lock(); 2423 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2424 rcu_read_unlock(); 2425 2426 return err; 2427 } 2428 EXPORT_SYMBOL(ip_route_input_noref); 2429 2430 /* called with rcu_read_lock held */ 2431 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2432 u8 tos, struct net_device *dev, struct fib_result *res) 2433 { 2434 /* Multicast recognition logic is moved from route cache to here. 2435 * The problem was that too many Ethernet cards have broken/missing 2436 * hardware multicast filters :-( As result the host on multicasting 2437 * network acquires a lot of useless route cache entries, sort of 2438 * SDR messages from all the world. Now we try to get rid of them. 2439 * Really, provided software IP multicast filter is organized 2440 * reasonably (at least, hashed), it does not result in a slowdown 2441 * comparing with route cache reject entries. 2442 * Note, that multicast routers are not affected, because 2443 * route cache entry is created eventually. 2444 */ 2445 if (ipv4_is_multicast(daddr)) { 2446 struct in_device *in_dev = __in_dev_get_rcu(dev); 2447 int our = 0; 2448 int err = -EINVAL; 2449 2450 if (!in_dev) 2451 return err; 2452 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2453 ip_hdr(skb)->protocol); 2454 2455 /* check l3 master if no match yet */ 2456 if (!our && netif_is_l3_slave(dev)) { 2457 struct in_device *l3_in_dev; 2458 2459 l3_in_dev = __in_dev_get_rcu(skb->dev); 2460 if (l3_in_dev) 2461 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2462 ip_hdr(skb)->protocol); 2463 } 2464 2465 if (our 2466 #ifdef CONFIG_IP_MROUTE 2467 || 2468 (!ipv4_is_local_multicast(daddr) && 2469 IN_DEV_MFORWARD(in_dev)) 2470 #endif 2471 ) { 2472 err = ip_route_input_mc(skb, daddr, saddr, 2473 tos, dev, our); 2474 } 2475 return err; 2476 } 2477 2478 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2479 } 2480 2481 /* called with rcu_read_lock() */ 2482 static struct rtable *__mkroute_output(const struct fib_result *res, 2483 const struct flowi4 *fl4, int orig_oif, 2484 struct net_device *dev_out, 2485 unsigned int flags) 2486 { 2487 struct fib_info *fi = res->fi; 2488 struct fib_nh_exception *fnhe; 2489 struct in_device *in_dev; 2490 u16 type = res->type; 2491 struct rtable *rth; 2492 bool do_cache; 2493 2494 in_dev = __in_dev_get_rcu(dev_out); 2495 if (!in_dev) 2496 return ERR_PTR(-EINVAL); 2497 2498 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2499 if (ipv4_is_loopback(fl4->saddr) && 2500 !(dev_out->flags & IFF_LOOPBACK) && 2501 !netif_is_l3_master(dev_out)) 2502 return ERR_PTR(-EINVAL); 2503 2504 if (ipv4_is_lbcast(fl4->daddr)) 2505 type = RTN_BROADCAST; 2506 else if (ipv4_is_multicast(fl4->daddr)) 2507 type = RTN_MULTICAST; 2508 else if (ipv4_is_zeronet(fl4->daddr)) 2509 return ERR_PTR(-EINVAL); 2510 2511 if (dev_out->flags & IFF_LOOPBACK) 2512 flags |= RTCF_LOCAL; 2513 2514 do_cache = true; 2515 if (type == RTN_BROADCAST) { 2516 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2517 fi = NULL; 2518 } else if (type == RTN_MULTICAST) { 2519 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2520 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2521 fl4->flowi4_proto)) 2522 flags &= ~RTCF_LOCAL; 2523 else 2524 do_cache = false; 2525 /* If multicast route do not exist use 2526 * default one, but do not gateway in this case. 2527 * Yes, it is hack. 2528 */ 2529 if (fi && res->prefixlen < 4) 2530 fi = NULL; 2531 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2532 (orig_oif != dev_out->ifindex)) { 2533 /* For local routes that require a particular output interface 2534 * we do not want to cache the result. Caching the result 2535 * causes incorrect behaviour when there are multiple source 2536 * addresses on the interface, the end result being that if the 2537 * intended recipient is waiting on that interface for the 2538 * packet he won't receive it because it will be delivered on 2539 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2540 * be set to the loopback interface as well. 2541 */ 2542 do_cache = false; 2543 } 2544 2545 fnhe = NULL; 2546 do_cache &= fi != NULL; 2547 if (fi) { 2548 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2549 struct rtable __rcu **prth; 2550 2551 fnhe = find_exception(nhc, fl4->daddr); 2552 if (!do_cache) 2553 goto add; 2554 if (fnhe) { 2555 prth = &fnhe->fnhe_rth_output; 2556 } else { 2557 if (unlikely(fl4->flowi4_flags & 2558 FLOWI_FLAG_KNOWN_NH && 2559 !(nhc->nhc_gw_family && 2560 nhc->nhc_scope == RT_SCOPE_LINK))) { 2561 do_cache = false; 2562 goto add; 2563 } 2564 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2565 } 2566 rth = rcu_dereference(*prth); 2567 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2568 return rth; 2569 } 2570 2571 add: 2572 rth = rt_dst_alloc(dev_out, flags, type, 2573 IN_DEV_ORCONF(in_dev, NOPOLICY), 2574 IN_DEV_ORCONF(in_dev, NOXFRM)); 2575 if (!rth) 2576 return ERR_PTR(-ENOBUFS); 2577 2578 rth->rt_iif = orig_oif; 2579 2580 RT_CACHE_STAT_INC(out_slow_tot); 2581 2582 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2583 if (flags & RTCF_LOCAL && 2584 !(dev_out->flags & IFF_LOOPBACK)) { 2585 rth->dst.output = ip_mc_output; 2586 RT_CACHE_STAT_INC(out_slow_mc); 2587 } 2588 #ifdef CONFIG_IP_MROUTE 2589 if (type == RTN_MULTICAST) { 2590 if (IN_DEV_MFORWARD(in_dev) && 2591 !ipv4_is_local_multicast(fl4->daddr)) { 2592 rth->dst.input = ip_mr_input; 2593 rth->dst.output = ip_mc_output; 2594 } 2595 } 2596 #endif 2597 } 2598 2599 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2600 lwtunnel_set_redirect(&rth->dst); 2601 2602 return rth; 2603 } 2604 2605 /* 2606 * Major route resolver routine. 2607 */ 2608 2609 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2610 const struct sk_buff *skb) 2611 { 2612 __u8 tos = RT_FL_TOS(fl4); 2613 struct fib_result res = { 2614 .type = RTN_UNSPEC, 2615 .fi = NULL, 2616 .table = NULL, 2617 .tclassid = 0, 2618 }; 2619 struct rtable *rth; 2620 2621 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2622 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2623 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2624 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2625 2626 rcu_read_lock(); 2627 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2628 rcu_read_unlock(); 2629 2630 return rth; 2631 } 2632 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2633 2634 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2635 struct fib_result *res, 2636 const struct sk_buff *skb) 2637 { 2638 struct net_device *dev_out = NULL; 2639 int orig_oif = fl4->flowi4_oif; 2640 unsigned int flags = 0; 2641 struct rtable *rth; 2642 int err; 2643 2644 if (fl4->saddr) { 2645 if (ipv4_is_multicast(fl4->saddr) || 2646 ipv4_is_lbcast(fl4->saddr) || 2647 ipv4_is_zeronet(fl4->saddr)) { 2648 rth = ERR_PTR(-EINVAL); 2649 goto out; 2650 } 2651 2652 rth = ERR_PTR(-ENETUNREACH); 2653 2654 /* I removed check for oif == dev_out->oif here. 2655 * It was wrong for two reasons: 2656 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2657 * is assigned to multiple interfaces. 2658 * 2. Moreover, we are allowed to send packets with saddr 2659 * of another iface. --ANK 2660 */ 2661 2662 if (fl4->flowi4_oif == 0 && 2663 (ipv4_is_multicast(fl4->daddr) || 2664 ipv4_is_lbcast(fl4->daddr))) { 2665 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2666 dev_out = __ip_dev_find(net, fl4->saddr, false); 2667 if (!dev_out) 2668 goto out; 2669 2670 /* Special hack: user can direct multicasts 2671 * and limited broadcast via necessary interface 2672 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2673 * This hack is not just for fun, it allows 2674 * vic,vat and friends to work. 2675 * They bind socket to loopback, set ttl to zero 2676 * and expect that it will work. 2677 * From the viewpoint of routing cache they are broken, 2678 * because we are not allowed to build multicast path 2679 * with loopback source addr (look, routing cache 2680 * cannot know, that ttl is zero, so that packet 2681 * will not leave this host and route is valid). 2682 * Luckily, this hack is good workaround. 2683 */ 2684 2685 fl4->flowi4_oif = dev_out->ifindex; 2686 goto make_route; 2687 } 2688 2689 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2690 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2691 if (!__ip_dev_find(net, fl4->saddr, false)) 2692 goto out; 2693 } 2694 } 2695 2696 2697 if (fl4->flowi4_oif) { 2698 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2699 rth = ERR_PTR(-ENODEV); 2700 if (!dev_out) 2701 goto out; 2702 2703 /* RACE: Check return value of inet_select_addr instead. */ 2704 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2705 rth = ERR_PTR(-ENETUNREACH); 2706 goto out; 2707 } 2708 if (ipv4_is_local_multicast(fl4->daddr) || 2709 ipv4_is_lbcast(fl4->daddr) || 2710 fl4->flowi4_proto == IPPROTO_IGMP) { 2711 if (!fl4->saddr) 2712 fl4->saddr = inet_select_addr(dev_out, 0, 2713 RT_SCOPE_LINK); 2714 goto make_route; 2715 } 2716 if (!fl4->saddr) { 2717 if (ipv4_is_multicast(fl4->daddr)) 2718 fl4->saddr = inet_select_addr(dev_out, 0, 2719 fl4->flowi4_scope); 2720 else if (!fl4->daddr) 2721 fl4->saddr = inet_select_addr(dev_out, 0, 2722 RT_SCOPE_HOST); 2723 } 2724 } 2725 2726 if (!fl4->daddr) { 2727 fl4->daddr = fl4->saddr; 2728 if (!fl4->daddr) 2729 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2730 dev_out = net->loopback_dev; 2731 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2732 res->type = RTN_LOCAL; 2733 flags |= RTCF_LOCAL; 2734 goto make_route; 2735 } 2736 2737 err = fib_lookup(net, fl4, res, 0); 2738 if (err) { 2739 res->fi = NULL; 2740 res->table = NULL; 2741 if (fl4->flowi4_oif && 2742 (ipv4_is_multicast(fl4->daddr) || 2743 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2744 /* Apparently, routing tables are wrong. Assume, 2745 * that the destination is on link. 2746 * 2747 * WHY? DW. 2748 * Because we are allowed to send to iface 2749 * even if it has NO routes and NO assigned 2750 * addresses. When oif is specified, routing 2751 * tables are looked up with only one purpose: 2752 * to catch if destination is gatewayed, rather than 2753 * direct. Moreover, if MSG_DONTROUTE is set, 2754 * we send packet, ignoring both routing tables 2755 * and ifaddr state. --ANK 2756 * 2757 * 2758 * We could make it even if oif is unknown, 2759 * likely IPv6, but we do not. 2760 */ 2761 2762 if (fl4->saddr == 0) 2763 fl4->saddr = inet_select_addr(dev_out, 0, 2764 RT_SCOPE_LINK); 2765 res->type = RTN_UNICAST; 2766 goto make_route; 2767 } 2768 rth = ERR_PTR(err); 2769 goto out; 2770 } 2771 2772 if (res->type == RTN_LOCAL) { 2773 if (!fl4->saddr) { 2774 if (res->fi->fib_prefsrc) 2775 fl4->saddr = res->fi->fib_prefsrc; 2776 else 2777 fl4->saddr = fl4->daddr; 2778 } 2779 2780 /* L3 master device is the loopback for that domain */ 2781 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2782 net->loopback_dev; 2783 2784 /* make sure orig_oif points to fib result device even 2785 * though packet rx/tx happens over loopback or l3mdev 2786 */ 2787 orig_oif = FIB_RES_OIF(*res); 2788 2789 fl4->flowi4_oif = dev_out->ifindex; 2790 flags |= RTCF_LOCAL; 2791 goto make_route; 2792 } 2793 2794 fib_select_path(net, res, fl4, skb); 2795 2796 dev_out = FIB_RES_DEV(*res); 2797 2798 make_route: 2799 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2800 2801 out: 2802 return rth; 2803 } 2804 2805 static struct dst_ops ipv4_dst_blackhole_ops = { 2806 .family = AF_INET, 2807 .default_advmss = ipv4_default_advmss, 2808 .neigh_lookup = ipv4_neigh_lookup, 2809 .check = dst_blackhole_check, 2810 .cow_metrics = dst_blackhole_cow_metrics, 2811 .update_pmtu = dst_blackhole_update_pmtu, 2812 .redirect = dst_blackhole_redirect, 2813 .mtu = dst_blackhole_mtu, 2814 }; 2815 2816 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2817 { 2818 struct rtable *ort = (struct rtable *) dst_orig; 2819 struct rtable *rt; 2820 2821 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2822 if (rt) { 2823 struct dst_entry *new = &rt->dst; 2824 2825 new->__use = 1; 2826 new->input = dst_discard; 2827 new->output = dst_discard_out; 2828 2829 new->dev = net->loopback_dev; 2830 dev_hold(new->dev); 2831 2832 rt->rt_is_input = ort->rt_is_input; 2833 rt->rt_iif = ort->rt_iif; 2834 rt->rt_pmtu = ort->rt_pmtu; 2835 rt->rt_mtu_locked = ort->rt_mtu_locked; 2836 2837 rt->rt_genid = rt_genid_ipv4(net); 2838 rt->rt_flags = ort->rt_flags; 2839 rt->rt_type = ort->rt_type; 2840 rt->rt_uses_gateway = ort->rt_uses_gateway; 2841 rt->rt_gw_family = ort->rt_gw_family; 2842 if (rt->rt_gw_family == AF_INET) 2843 rt->rt_gw4 = ort->rt_gw4; 2844 else if (rt->rt_gw_family == AF_INET6) 2845 rt->rt_gw6 = ort->rt_gw6; 2846 2847 INIT_LIST_HEAD(&rt->rt_uncached); 2848 } 2849 2850 dst_release(dst_orig); 2851 2852 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2853 } 2854 2855 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2856 const struct sock *sk) 2857 { 2858 struct rtable *rt = __ip_route_output_key(net, flp4); 2859 2860 if (IS_ERR(rt)) 2861 return rt; 2862 2863 if (flp4->flowi4_proto) { 2864 flp4->flowi4_oif = rt->dst.dev->ifindex; 2865 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2866 flowi4_to_flowi(flp4), 2867 sk, 0); 2868 } 2869 2870 return rt; 2871 } 2872 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2873 2874 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2875 struct net_device *dev, 2876 struct net *net, __be32 *saddr, 2877 const struct ip_tunnel_info *info, 2878 u8 protocol, bool use_cache) 2879 { 2880 #ifdef CONFIG_DST_CACHE 2881 struct dst_cache *dst_cache; 2882 #endif 2883 struct rtable *rt = NULL; 2884 struct flowi4 fl4; 2885 __u8 tos; 2886 2887 #ifdef CONFIG_DST_CACHE 2888 dst_cache = (struct dst_cache *)&info->dst_cache; 2889 if (use_cache) { 2890 rt = dst_cache_get_ip4(dst_cache, saddr); 2891 if (rt) 2892 return rt; 2893 } 2894 #endif 2895 memset(&fl4, 0, sizeof(fl4)); 2896 fl4.flowi4_mark = skb->mark; 2897 fl4.flowi4_proto = protocol; 2898 fl4.daddr = info->key.u.ipv4.dst; 2899 fl4.saddr = info->key.u.ipv4.src; 2900 tos = info->key.tos; 2901 fl4.flowi4_tos = RT_TOS(tos); 2902 2903 rt = ip_route_output_key(net, &fl4); 2904 if (IS_ERR(rt)) { 2905 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2906 return ERR_PTR(-ENETUNREACH); 2907 } 2908 if (rt->dst.dev == dev) { /* is this necessary? */ 2909 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2910 ip_rt_put(rt); 2911 return ERR_PTR(-ELOOP); 2912 } 2913 #ifdef CONFIG_DST_CACHE 2914 if (use_cache) 2915 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2916 #endif 2917 *saddr = fl4.saddr; 2918 return rt; 2919 } 2920 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2921 2922 /* called with rcu_read_lock held */ 2923 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2924 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2925 struct sk_buff *skb, u32 portid, u32 seq, 2926 unsigned int flags) 2927 { 2928 struct rtmsg *r; 2929 struct nlmsghdr *nlh; 2930 unsigned long expires = 0; 2931 u32 error; 2932 u32 metrics[RTAX_MAX]; 2933 2934 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2935 if (!nlh) 2936 return -EMSGSIZE; 2937 2938 r = nlmsg_data(nlh); 2939 r->rtm_family = AF_INET; 2940 r->rtm_dst_len = 32; 2941 r->rtm_src_len = 0; 2942 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2943 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2944 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2945 goto nla_put_failure; 2946 r->rtm_type = rt->rt_type; 2947 r->rtm_scope = RT_SCOPE_UNIVERSE; 2948 r->rtm_protocol = RTPROT_UNSPEC; 2949 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2950 if (rt->rt_flags & RTCF_NOTIFY) 2951 r->rtm_flags |= RTM_F_NOTIFY; 2952 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2953 r->rtm_flags |= RTCF_DOREDIRECT; 2954 2955 if (nla_put_in_addr(skb, RTA_DST, dst)) 2956 goto nla_put_failure; 2957 if (src) { 2958 r->rtm_src_len = 32; 2959 if (nla_put_in_addr(skb, RTA_SRC, src)) 2960 goto nla_put_failure; 2961 } 2962 if (rt->dst.dev && 2963 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2964 goto nla_put_failure; 2965 if (rt->dst.lwtstate && 2966 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2967 goto nla_put_failure; 2968 #ifdef CONFIG_IP_ROUTE_CLASSID 2969 if (rt->dst.tclassid && 2970 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2971 goto nla_put_failure; 2972 #endif 2973 if (fl4 && !rt_is_input_route(rt) && 2974 fl4->saddr != src) { 2975 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2976 goto nla_put_failure; 2977 } 2978 if (rt->rt_uses_gateway) { 2979 if (rt->rt_gw_family == AF_INET && 2980 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2981 goto nla_put_failure; 2982 } else if (rt->rt_gw_family == AF_INET6) { 2983 int alen = sizeof(struct in6_addr); 2984 struct nlattr *nla; 2985 struct rtvia *via; 2986 2987 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2988 if (!nla) 2989 goto nla_put_failure; 2990 2991 via = nla_data(nla); 2992 via->rtvia_family = AF_INET6; 2993 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2994 } 2995 } 2996 2997 expires = rt->dst.expires; 2998 if (expires) { 2999 unsigned long now = jiffies; 3000 3001 if (time_before(now, expires)) 3002 expires -= now; 3003 else 3004 expires = 0; 3005 } 3006 3007 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3008 if (rt->rt_pmtu && expires) 3009 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3010 if (rt->rt_mtu_locked && expires) 3011 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3012 if (rtnetlink_put_metrics(skb, metrics) < 0) 3013 goto nla_put_failure; 3014 3015 if (fl4) { 3016 if (fl4->flowi4_mark && 3017 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3018 goto nla_put_failure; 3019 3020 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3021 nla_put_u32(skb, RTA_UID, 3022 from_kuid_munged(current_user_ns(), 3023 fl4->flowi4_uid))) 3024 goto nla_put_failure; 3025 3026 if (rt_is_input_route(rt)) { 3027 #ifdef CONFIG_IP_MROUTE 3028 if (ipv4_is_multicast(dst) && 3029 !ipv4_is_local_multicast(dst) && 3030 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3031 int err = ipmr_get_route(net, skb, 3032 fl4->saddr, fl4->daddr, 3033 r, portid); 3034 3035 if (err <= 0) { 3036 if (err == 0) 3037 return 0; 3038 goto nla_put_failure; 3039 } 3040 } else 3041 #endif 3042 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3043 goto nla_put_failure; 3044 } 3045 } 3046 3047 error = rt->dst.error; 3048 3049 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3050 goto nla_put_failure; 3051 3052 nlmsg_end(skb, nlh); 3053 return 0; 3054 3055 nla_put_failure: 3056 nlmsg_cancel(skb, nlh); 3057 return -EMSGSIZE; 3058 } 3059 3060 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3061 struct netlink_callback *cb, u32 table_id, 3062 struct fnhe_hash_bucket *bucket, int genid, 3063 int *fa_index, int fa_start, unsigned int flags) 3064 { 3065 int i; 3066 3067 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3068 struct fib_nh_exception *fnhe; 3069 3070 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3071 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3072 struct rtable *rt; 3073 int err; 3074 3075 if (*fa_index < fa_start) 3076 goto next; 3077 3078 if (fnhe->fnhe_genid != genid) 3079 goto next; 3080 3081 if (fnhe->fnhe_expires && 3082 time_after(jiffies, fnhe->fnhe_expires)) 3083 goto next; 3084 3085 rt = rcu_dereference(fnhe->fnhe_rth_input); 3086 if (!rt) 3087 rt = rcu_dereference(fnhe->fnhe_rth_output); 3088 if (!rt) 3089 goto next; 3090 3091 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3092 table_id, NULL, skb, 3093 NETLINK_CB(cb->skb).portid, 3094 cb->nlh->nlmsg_seq, flags); 3095 if (err) 3096 return err; 3097 next: 3098 (*fa_index)++; 3099 } 3100 } 3101 3102 return 0; 3103 } 3104 3105 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3106 u32 table_id, struct fib_info *fi, 3107 int *fa_index, int fa_start, unsigned int flags) 3108 { 3109 struct net *net = sock_net(cb->skb->sk); 3110 int nhsel, genid = fnhe_genid(net); 3111 3112 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3113 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3114 struct fnhe_hash_bucket *bucket; 3115 int err; 3116 3117 if (nhc->nhc_flags & RTNH_F_DEAD) 3118 continue; 3119 3120 rcu_read_lock(); 3121 bucket = rcu_dereference(nhc->nhc_exceptions); 3122 err = 0; 3123 if (bucket) 3124 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3125 genid, fa_index, fa_start, 3126 flags); 3127 rcu_read_unlock(); 3128 if (err) 3129 return err; 3130 } 3131 3132 return 0; 3133 } 3134 3135 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3136 u8 ip_proto, __be16 sport, 3137 __be16 dport) 3138 { 3139 struct sk_buff *skb; 3140 struct iphdr *iph; 3141 3142 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3143 if (!skb) 3144 return NULL; 3145 3146 /* Reserve room for dummy headers, this skb can pass 3147 * through good chunk of routing engine. 3148 */ 3149 skb_reset_mac_header(skb); 3150 skb_reset_network_header(skb); 3151 skb->protocol = htons(ETH_P_IP); 3152 iph = skb_put(skb, sizeof(struct iphdr)); 3153 iph->protocol = ip_proto; 3154 iph->saddr = src; 3155 iph->daddr = dst; 3156 iph->version = 0x4; 3157 iph->frag_off = 0; 3158 iph->ihl = 0x5; 3159 skb_set_transport_header(skb, skb->len); 3160 3161 switch (iph->protocol) { 3162 case IPPROTO_UDP: { 3163 struct udphdr *udph; 3164 3165 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3166 udph->source = sport; 3167 udph->dest = dport; 3168 udph->len = htons(sizeof(struct udphdr)); 3169 udph->check = 0; 3170 break; 3171 } 3172 case IPPROTO_TCP: { 3173 struct tcphdr *tcph; 3174 3175 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3176 tcph->source = sport; 3177 tcph->dest = dport; 3178 tcph->doff = sizeof(struct tcphdr) / 4; 3179 tcph->rst = 1; 3180 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3181 src, dst, 0); 3182 break; 3183 } 3184 case IPPROTO_ICMP: { 3185 struct icmphdr *icmph; 3186 3187 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3188 icmph->type = ICMP_ECHO; 3189 icmph->code = 0; 3190 } 3191 } 3192 3193 return skb; 3194 } 3195 3196 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3197 const struct nlmsghdr *nlh, 3198 struct nlattr **tb, 3199 struct netlink_ext_ack *extack) 3200 { 3201 struct rtmsg *rtm; 3202 int i, err; 3203 3204 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3205 NL_SET_ERR_MSG(extack, 3206 "ipv4: Invalid header for route get request"); 3207 return -EINVAL; 3208 } 3209 3210 if (!netlink_strict_get_check(skb)) 3211 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3212 rtm_ipv4_policy, extack); 3213 3214 rtm = nlmsg_data(nlh); 3215 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3216 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3217 rtm->rtm_table || rtm->rtm_protocol || 3218 rtm->rtm_scope || rtm->rtm_type) { 3219 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3220 return -EINVAL; 3221 } 3222 3223 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3224 RTM_F_LOOKUP_TABLE | 3225 RTM_F_FIB_MATCH)) { 3226 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3227 return -EINVAL; 3228 } 3229 3230 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3231 rtm_ipv4_policy, extack); 3232 if (err) 3233 return err; 3234 3235 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3236 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3237 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3238 return -EINVAL; 3239 } 3240 3241 for (i = 0; i <= RTA_MAX; i++) { 3242 if (!tb[i]) 3243 continue; 3244 3245 switch (i) { 3246 case RTA_IIF: 3247 case RTA_OIF: 3248 case RTA_SRC: 3249 case RTA_DST: 3250 case RTA_IP_PROTO: 3251 case RTA_SPORT: 3252 case RTA_DPORT: 3253 case RTA_MARK: 3254 case RTA_UID: 3255 break; 3256 default: 3257 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3258 return -EINVAL; 3259 } 3260 } 3261 3262 return 0; 3263 } 3264 3265 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3266 struct netlink_ext_ack *extack) 3267 { 3268 struct net *net = sock_net(in_skb->sk); 3269 struct nlattr *tb[RTA_MAX+1]; 3270 u32 table_id = RT_TABLE_MAIN; 3271 __be16 sport = 0, dport = 0; 3272 struct fib_result res = {}; 3273 u8 ip_proto = IPPROTO_UDP; 3274 struct rtable *rt = NULL; 3275 struct sk_buff *skb; 3276 struct rtmsg *rtm; 3277 struct flowi4 fl4 = {}; 3278 __be32 dst = 0; 3279 __be32 src = 0; 3280 kuid_t uid; 3281 u32 iif; 3282 int err; 3283 int mark; 3284 3285 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3286 if (err < 0) 3287 return err; 3288 3289 rtm = nlmsg_data(nlh); 3290 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3291 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3292 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3293 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3294 if (tb[RTA_UID]) 3295 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3296 else 3297 uid = (iif ? INVALID_UID : current_uid()); 3298 3299 if (tb[RTA_IP_PROTO]) { 3300 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3301 &ip_proto, AF_INET, extack); 3302 if (err) 3303 return err; 3304 } 3305 3306 if (tb[RTA_SPORT]) 3307 sport = nla_get_be16(tb[RTA_SPORT]); 3308 3309 if (tb[RTA_DPORT]) 3310 dport = nla_get_be16(tb[RTA_DPORT]); 3311 3312 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3313 if (!skb) 3314 return -ENOBUFS; 3315 3316 fl4.daddr = dst; 3317 fl4.saddr = src; 3318 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3319 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3320 fl4.flowi4_mark = mark; 3321 fl4.flowi4_uid = uid; 3322 if (sport) 3323 fl4.fl4_sport = sport; 3324 if (dport) 3325 fl4.fl4_dport = dport; 3326 fl4.flowi4_proto = ip_proto; 3327 3328 rcu_read_lock(); 3329 3330 if (iif) { 3331 struct net_device *dev; 3332 3333 dev = dev_get_by_index_rcu(net, iif); 3334 if (!dev) { 3335 err = -ENODEV; 3336 goto errout_rcu; 3337 } 3338 3339 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3340 skb->dev = dev; 3341 skb->mark = mark; 3342 err = ip_route_input_rcu(skb, dst, src, 3343 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3344 &res); 3345 3346 rt = skb_rtable(skb); 3347 if (err == 0 && rt->dst.error) 3348 err = -rt->dst.error; 3349 } else { 3350 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3351 skb->dev = net->loopback_dev; 3352 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3353 err = 0; 3354 if (IS_ERR(rt)) 3355 err = PTR_ERR(rt); 3356 else 3357 skb_dst_set(skb, &rt->dst); 3358 } 3359 3360 if (err) 3361 goto errout_rcu; 3362 3363 if (rtm->rtm_flags & RTM_F_NOTIFY) 3364 rt->rt_flags |= RTCF_NOTIFY; 3365 3366 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3367 table_id = res.table ? res.table->tb_id : 0; 3368 3369 /* reset skb for netlink reply msg */ 3370 skb_trim(skb, 0); 3371 skb_reset_network_header(skb); 3372 skb_reset_transport_header(skb); 3373 skb_reset_mac_header(skb); 3374 3375 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3376 struct fib_rt_info fri; 3377 3378 if (!res.fi) { 3379 err = fib_props[res.type].error; 3380 if (!err) 3381 err = -EHOSTUNREACH; 3382 goto errout_rcu; 3383 } 3384 fri.fi = res.fi; 3385 fri.tb_id = table_id; 3386 fri.dst = res.prefix; 3387 fri.dst_len = res.prefixlen; 3388 fri.tos = fl4.flowi4_tos; 3389 fri.type = rt->rt_type; 3390 fri.offload = 0; 3391 fri.trap = 0; 3392 fri.offload_failed = 0; 3393 if (res.fa_head) { 3394 struct fib_alias *fa; 3395 3396 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3397 u8 slen = 32 - fri.dst_len; 3398 3399 if (fa->fa_slen == slen && 3400 fa->tb_id == fri.tb_id && 3401 fa->fa_tos == fri.tos && 3402 fa->fa_info == res.fi && 3403 fa->fa_type == fri.type) { 3404 fri.offload = fa->offload; 3405 fri.trap = fa->trap; 3406 break; 3407 } 3408 } 3409 } 3410 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3411 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3412 } else { 3413 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3414 NETLINK_CB(in_skb).portid, 3415 nlh->nlmsg_seq, 0); 3416 } 3417 if (err < 0) 3418 goto errout_rcu; 3419 3420 rcu_read_unlock(); 3421 3422 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3423 3424 errout_free: 3425 return err; 3426 errout_rcu: 3427 rcu_read_unlock(); 3428 kfree_skb(skb); 3429 goto errout_free; 3430 } 3431 3432 void ip_rt_multicast_event(struct in_device *in_dev) 3433 { 3434 rt_cache_flush(dev_net(in_dev->dev)); 3435 } 3436 3437 #ifdef CONFIG_SYSCTL 3438 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3439 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3440 static int ip_rt_gc_elasticity __read_mostly = 8; 3441 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3442 3443 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3444 void *buffer, size_t *lenp, loff_t *ppos) 3445 { 3446 struct net *net = (struct net *)__ctl->extra1; 3447 3448 if (write) { 3449 rt_cache_flush(net); 3450 fnhe_genid_bump(net); 3451 return 0; 3452 } 3453 3454 return -EINVAL; 3455 } 3456 3457 static struct ctl_table ipv4_route_table[] = { 3458 { 3459 .procname = "gc_thresh", 3460 .data = &ipv4_dst_ops.gc_thresh, 3461 .maxlen = sizeof(int), 3462 .mode = 0644, 3463 .proc_handler = proc_dointvec, 3464 }, 3465 { 3466 .procname = "max_size", 3467 .data = &ip_rt_max_size, 3468 .maxlen = sizeof(int), 3469 .mode = 0644, 3470 .proc_handler = proc_dointvec, 3471 }, 3472 { 3473 /* Deprecated. Use gc_min_interval_ms */ 3474 3475 .procname = "gc_min_interval", 3476 .data = &ip_rt_gc_min_interval, 3477 .maxlen = sizeof(int), 3478 .mode = 0644, 3479 .proc_handler = proc_dointvec_jiffies, 3480 }, 3481 { 3482 .procname = "gc_min_interval_ms", 3483 .data = &ip_rt_gc_min_interval, 3484 .maxlen = sizeof(int), 3485 .mode = 0644, 3486 .proc_handler = proc_dointvec_ms_jiffies, 3487 }, 3488 { 3489 .procname = "gc_timeout", 3490 .data = &ip_rt_gc_timeout, 3491 .maxlen = sizeof(int), 3492 .mode = 0644, 3493 .proc_handler = proc_dointvec_jiffies, 3494 }, 3495 { 3496 .procname = "gc_interval", 3497 .data = &ip_rt_gc_interval, 3498 .maxlen = sizeof(int), 3499 .mode = 0644, 3500 .proc_handler = proc_dointvec_jiffies, 3501 }, 3502 { 3503 .procname = "redirect_load", 3504 .data = &ip_rt_redirect_load, 3505 .maxlen = sizeof(int), 3506 .mode = 0644, 3507 .proc_handler = proc_dointvec, 3508 }, 3509 { 3510 .procname = "redirect_number", 3511 .data = &ip_rt_redirect_number, 3512 .maxlen = sizeof(int), 3513 .mode = 0644, 3514 .proc_handler = proc_dointvec, 3515 }, 3516 { 3517 .procname = "redirect_silence", 3518 .data = &ip_rt_redirect_silence, 3519 .maxlen = sizeof(int), 3520 .mode = 0644, 3521 .proc_handler = proc_dointvec, 3522 }, 3523 { 3524 .procname = "error_cost", 3525 .data = &ip_rt_error_cost, 3526 .maxlen = sizeof(int), 3527 .mode = 0644, 3528 .proc_handler = proc_dointvec, 3529 }, 3530 { 3531 .procname = "error_burst", 3532 .data = &ip_rt_error_burst, 3533 .maxlen = sizeof(int), 3534 .mode = 0644, 3535 .proc_handler = proc_dointvec, 3536 }, 3537 { 3538 .procname = "gc_elasticity", 3539 .data = &ip_rt_gc_elasticity, 3540 .maxlen = sizeof(int), 3541 .mode = 0644, 3542 .proc_handler = proc_dointvec, 3543 }, 3544 { 3545 .procname = "mtu_expires", 3546 .data = &ip_rt_mtu_expires, 3547 .maxlen = sizeof(int), 3548 .mode = 0644, 3549 .proc_handler = proc_dointvec_jiffies, 3550 }, 3551 { 3552 .procname = "min_pmtu", 3553 .data = &ip_rt_min_pmtu, 3554 .maxlen = sizeof(int), 3555 .mode = 0644, 3556 .proc_handler = proc_dointvec_minmax, 3557 .extra1 = &ip_min_valid_pmtu, 3558 }, 3559 { 3560 .procname = "min_adv_mss", 3561 .data = &ip_rt_min_advmss, 3562 .maxlen = sizeof(int), 3563 .mode = 0644, 3564 .proc_handler = proc_dointvec, 3565 }, 3566 { } 3567 }; 3568 3569 static const char ipv4_route_flush_procname[] = "flush"; 3570 3571 static struct ctl_table ipv4_route_flush_table[] = { 3572 { 3573 .procname = ipv4_route_flush_procname, 3574 .maxlen = sizeof(int), 3575 .mode = 0200, 3576 .proc_handler = ipv4_sysctl_rtcache_flush, 3577 }, 3578 { }, 3579 }; 3580 3581 static __net_init int sysctl_route_net_init(struct net *net) 3582 { 3583 struct ctl_table *tbl; 3584 3585 tbl = ipv4_route_flush_table; 3586 if (!net_eq(net, &init_net)) { 3587 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3588 if (!tbl) 3589 goto err_dup; 3590 3591 /* Don't export non-whitelisted sysctls to unprivileged users */ 3592 if (net->user_ns != &init_user_ns) { 3593 if (tbl[0].procname != ipv4_route_flush_procname) 3594 tbl[0].procname = NULL; 3595 } 3596 } 3597 tbl[0].extra1 = net; 3598 3599 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3600 if (!net->ipv4.route_hdr) 3601 goto err_reg; 3602 return 0; 3603 3604 err_reg: 3605 if (tbl != ipv4_route_flush_table) 3606 kfree(tbl); 3607 err_dup: 3608 return -ENOMEM; 3609 } 3610 3611 static __net_exit void sysctl_route_net_exit(struct net *net) 3612 { 3613 struct ctl_table *tbl; 3614 3615 tbl = net->ipv4.route_hdr->ctl_table_arg; 3616 unregister_net_sysctl_table(net->ipv4.route_hdr); 3617 BUG_ON(tbl == ipv4_route_flush_table); 3618 kfree(tbl); 3619 } 3620 3621 static __net_initdata struct pernet_operations sysctl_route_ops = { 3622 .init = sysctl_route_net_init, 3623 .exit = sysctl_route_net_exit, 3624 }; 3625 #endif 3626 3627 static __net_init int rt_genid_init(struct net *net) 3628 { 3629 atomic_set(&net->ipv4.rt_genid, 0); 3630 atomic_set(&net->fnhe_genid, 0); 3631 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3632 return 0; 3633 } 3634 3635 static __net_initdata struct pernet_operations rt_genid_ops = { 3636 .init = rt_genid_init, 3637 }; 3638 3639 static int __net_init ipv4_inetpeer_init(struct net *net) 3640 { 3641 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3642 3643 if (!bp) 3644 return -ENOMEM; 3645 inet_peer_base_init(bp); 3646 net->ipv4.peers = bp; 3647 return 0; 3648 } 3649 3650 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3651 { 3652 struct inet_peer_base *bp = net->ipv4.peers; 3653 3654 net->ipv4.peers = NULL; 3655 inetpeer_invalidate_tree(bp); 3656 kfree(bp); 3657 } 3658 3659 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3660 .init = ipv4_inetpeer_init, 3661 .exit = ipv4_inetpeer_exit, 3662 }; 3663 3664 #ifdef CONFIG_IP_ROUTE_CLASSID 3665 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3666 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3667 3668 int __init ip_rt_init(void) 3669 { 3670 void *idents_hash; 3671 int cpu; 3672 3673 /* For modern hosts, this will use 2 MB of memory */ 3674 idents_hash = alloc_large_system_hash("IP idents", 3675 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3676 0, 3677 16, /* one bucket per 64 KB */ 3678 HASH_ZERO, 3679 NULL, 3680 &ip_idents_mask, 3681 2048, 3682 256*1024); 3683 3684 ip_idents = idents_hash; 3685 3686 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3687 3688 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3689 3690 for_each_possible_cpu(cpu) { 3691 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3692 3693 INIT_LIST_HEAD(&ul->head); 3694 spin_lock_init(&ul->lock); 3695 } 3696 #ifdef CONFIG_IP_ROUTE_CLASSID 3697 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3698 if (!ip_rt_acct) 3699 panic("IP: failed to allocate ip_rt_acct\n"); 3700 #endif 3701 3702 ipv4_dst_ops.kmem_cachep = 3703 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3704 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3705 3706 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3707 3708 if (dst_entries_init(&ipv4_dst_ops) < 0) 3709 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3710 3711 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3712 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3713 3714 ipv4_dst_ops.gc_thresh = ~0; 3715 ip_rt_max_size = INT_MAX; 3716 3717 devinet_init(); 3718 ip_fib_init(); 3719 3720 if (ip_rt_proc_init()) 3721 pr_err("Unable to create route proc files\n"); 3722 #ifdef CONFIG_XFRM 3723 xfrm_init(); 3724 xfrm4_init(); 3725 #endif 3726 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3727 RTNL_FLAG_DOIT_UNLOCKED); 3728 3729 #ifdef CONFIG_SYSCTL 3730 register_pernet_subsys(&sysctl_route_ops); 3731 #endif 3732 register_pernet_subsys(&rt_genid_ops); 3733 register_pernet_subsys(&ipv4_inetpeer_ops); 3734 return 0; 3735 } 3736 3737 #ifdef CONFIG_SYSCTL 3738 /* 3739 * We really need to sanitize the damn ipv4 init order, then all 3740 * this nonsense will go away. 3741 */ 3742 void __init ip_static_sysctl_init(void) 3743 { 3744 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3745 } 3746 #endif 3747