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/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_GC_TIMEOUT (300*HZ) 110 111 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 112 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 113 #define DEFAULT_MIN_ADVMSS 256 114 static int ip_rt_max_size; 115 static int ip_rt_redirect_number __read_mostly = 9; 116 static int ip_rt_redirect_load __read_mostly = HZ / 50; 117 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 118 static int ip_rt_error_cost __read_mostly = HZ; 119 static int ip_rt_error_burst __read_mostly = 5 * HZ; 120 121 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 122 123 /* 124 * Interface to generic destination cache. 125 */ 126 127 INDIRECT_CALLABLE_SCOPE 128 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 129 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 130 INDIRECT_CALLABLE_SCOPE 131 unsigned int ipv4_mtu(const struct dst_entry *dst); 132 static void ipv4_negative_advice(struct sock *sk, 133 struct dst_entry *dst); 134 static void ipv4_link_failure(struct sk_buff *skb); 135 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 136 struct sk_buff *skb, u32 mtu, 137 bool confirm_neigh); 138 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 139 struct sk_buff *skb); 140 static void ipv4_dst_destroy(struct dst_entry *dst); 141 142 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 143 { 144 WARN_ON(1); 145 return NULL; 146 } 147 148 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 149 struct sk_buff *skb, 150 const void *daddr); 151 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 152 153 static struct dst_ops ipv4_dst_ops = { 154 .family = AF_INET, 155 .check = ipv4_dst_check, 156 .default_advmss = ipv4_default_advmss, 157 .mtu = ipv4_mtu, 158 .cow_metrics = ipv4_cow_metrics, 159 .destroy = ipv4_dst_destroy, 160 .negative_advice = ipv4_negative_advice, 161 .link_failure = ipv4_link_failure, 162 .update_pmtu = ip_rt_update_pmtu, 163 .redirect = ip_do_redirect, 164 .local_out = __ip_local_out, 165 .neigh_lookup = ipv4_neigh_lookup, 166 .confirm_neigh = ipv4_confirm_neigh, 167 }; 168 169 #define ECN_OR_COST(class) TC_PRIO_##class 170 171 const __u8 ip_tos2prio[16] = { 172 TC_PRIO_BESTEFFORT, 173 ECN_OR_COST(BESTEFFORT), 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BULK, 177 ECN_OR_COST(BULK), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_INTERACTIVE, 181 ECN_OR_COST(INTERACTIVE), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE_BULK, 185 ECN_OR_COST(INTERACTIVE_BULK), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK) 188 }; 189 EXPORT_SYMBOL(ip_tos2prio); 190 191 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 192 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 193 194 #ifdef CONFIG_PROC_FS 195 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 196 { 197 if (*pos) 198 return NULL; 199 return SEQ_START_TOKEN; 200 } 201 202 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 203 { 204 ++*pos; 205 return NULL; 206 } 207 208 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 209 { 210 } 211 212 static int rt_cache_seq_show(struct seq_file *seq, void *v) 213 { 214 if (v == SEQ_START_TOKEN) 215 seq_printf(seq, "%-127s\n", 216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 218 "HHUptod\tSpecDst"); 219 return 0; 220 } 221 222 static const struct seq_operations rt_cache_seq_ops = { 223 .start = rt_cache_seq_start, 224 .next = rt_cache_seq_next, 225 .stop = rt_cache_seq_stop, 226 .show = rt_cache_seq_show, 227 }; 228 229 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 230 { 231 int cpu; 232 233 if (*pos == 0) 234 return SEQ_START_TOKEN; 235 236 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 237 if (!cpu_possible(cpu)) 238 continue; 239 *pos = cpu+1; 240 return &per_cpu(rt_cache_stat, cpu); 241 } 242 return NULL; 243 } 244 245 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 246 { 247 int cpu; 248 249 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 250 if (!cpu_possible(cpu)) 251 continue; 252 *pos = cpu+1; 253 return &per_cpu(rt_cache_stat, cpu); 254 } 255 (*pos)++; 256 return NULL; 257 258 } 259 260 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 261 { 262 263 } 264 265 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 266 { 267 struct rt_cache_stat *st = v; 268 269 if (v == SEQ_START_TOKEN) { 270 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"); 271 return 0; 272 } 273 274 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 275 "%08x %08x %08x %08x %08x %08x " 276 "%08x %08x %08x %08x\n", 277 dst_entries_get_slow(&ipv4_dst_ops), 278 0, /* st->in_hit */ 279 st->in_slow_tot, 280 st->in_slow_mc, 281 st->in_no_route, 282 st->in_brd, 283 st->in_martian_dst, 284 st->in_martian_src, 285 286 0, /* st->out_hit */ 287 st->out_slow_tot, 288 st->out_slow_mc, 289 290 0, /* st->gc_total */ 291 0, /* st->gc_ignored */ 292 0, /* st->gc_goal_miss */ 293 0, /* st->gc_dst_overflow */ 294 0, /* st->in_hlist_search */ 295 0 /* st->out_hlist_search */ 296 ); 297 return 0; 298 } 299 300 static const struct seq_operations rt_cpu_seq_ops = { 301 .start = rt_cpu_seq_start, 302 .next = rt_cpu_seq_next, 303 .stop = rt_cpu_seq_stop, 304 .show = rt_cpu_seq_show, 305 }; 306 307 #ifdef CONFIG_IP_ROUTE_CLASSID 308 static int rt_acct_proc_show(struct seq_file *m, void *v) 309 { 310 struct ip_rt_acct *dst, *src; 311 unsigned int i, j; 312 313 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 314 if (!dst) 315 return -ENOMEM; 316 317 for_each_possible_cpu(i) { 318 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 319 for (j = 0; j < 256; j++) { 320 dst[j].o_bytes += src[j].o_bytes; 321 dst[j].o_packets += src[j].o_packets; 322 dst[j].i_bytes += src[j].i_bytes; 323 dst[j].i_packets += src[j].i_packets; 324 } 325 } 326 327 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 328 kfree(dst); 329 return 0; 330 } 331 #endif 332 333 static int __net_init ip_rt_do_proc_init(struct net *net) 334 { 335 struct proc_dir_entry *pde; 336 337 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 338 &rt_cache_seq_ops); 339 if (!pde) 340 goto err1; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 343 &rt_cpu_seq_ops); 344 if (!pde) 345 goto err2; 346 347 #ifdef CONFIG_IP_ROUTE_CLASSID 348 pde = proc_create_single("rt_acct", 0, net->proc_net, 349 rt_acct_proc_show); 350 if (!pde) 351 goto err3; 352 #endif 353 return 0; 354 355 #ifdef CONFIG_IP_ROUTE_CLASSID 356 err3: 357 remove_proc_entry("rt_cache", net->proc_net_stat); 358 #endif 359 err2: 360 remove_proc_entry("rt_cache", net->proc_net); 361 err1: 362 return -ENOMEM; 363 } 364 365 static void __net_exit ip_rt_do_proc_exit(struct net *net) 366 { 367 remove_proc_entry("rt_cache", net->proc_net_stat); 368 remove_proc_entry("rt_cache", net->proc_net); 369 #ifdef CONFIG_IP_ROUTE_CLASSID 370 remove_proc_entry("rt_acct", net->proc_net); 371 #endif 372 } 373 374 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 375 .init = ip_rt_do_proc_init, 376 .exit = ip_rt_do_proc_exit, 377 }; 378 379 static int __init ip_rt_proc_init(void) 380 { 381 return register_pernet_subsys(&ip_rt_proc_ops); 382 } 383 384 #else 385 static inline int ip_rt_proc_init(void) 386 { 387 return 0; 388 } 389 #endif /* CONFIG_PROC_FS */ 390 391 static inline bool rt_is_expired(const struct rtable *rth) 392 { 393 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 394 } 395 396 void rt_cache_flush(struct net *net) 397 { 398 rt_genid_bump_ipv4(net); 399 } 400 401 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 402 struct sk_buff *skb, 403 const void *daddr) 404 { 405 const struct rtable *rt = container_of(dst, struct rtable, dst); 406 struct net_device *dev = dst->dev; 407 struct neighbour *n; 408 409 rcu_read_lock(); 410 411 if (likely(rt->rt_gw_family == AF_INET)) { 412 n = ip_neigh_gw4(dev, rt->rt_gw4); 413 } else if (rt->rt_gw_family == AF_INET6) { 414 n = ip_neigh_gw6(dev, &rt->rt_gw6); 415 } else { 416 __be32 pkey; 417 418 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 419 n = ip_neigh_gw4(dev, pkey); 420 } 421 422 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 423 n = NULL; 424 425 rcu_read_unlock(); 426 427 return n; 428 } 429 430 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 431 { 432 const struct rtable *rt = container_of(dst, struct rtable, dst); 433 struct net_device *dev = dst->dev; 434 const __be32 *pkey = daddr; 435 436 if (rt->rt_gw_family == AF_INET) { 437 pkey = (const __be32 *)&rt->rt_gw4; 438 } else if (rt->rt_gw_family == AF_INET6) { 439 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 440 } else if (!daddr || 441 (rt->rt_flags & 442 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 443 return; 444 } 445 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 446 } 447 448 /* Hash tables of size 2048..262144 depending on RAM size. 449 * Each bucket uses 8 bytes. 450 */ 451 static u32 ip_idents_mask __read_mostly; 452 static atomic_t *ip_idents __read_mostly; 453 static u32 *ip_tstamps __read_mostly; 454 455 /* In order to protect privacy, we add a perturbation to identifiers 456 * if one generator is seldom used. This makes hard for an attacker 457 * to infer how many packets were sent between two points in time. 458 */ 459 static u32 ip_idents_reserve(u32 hash, int segs) 460 { 461 u32 bucket, old, now = (u32)jiffies; 462 atomic_t *p_id; 463 u32 *p_tstamp; 464 u32 delta = 0; 465 466 bucket = hash & ip_idents_mask; 467 p_tstamp = ip_tstamps + bucket; 468 p_id = ip_idents + bucket; 469 old = READ_ONCE(*p_tstamp); 470 471 if (old != now && cmpxchg(p_tstamp, old, now) == old) 472 delta = get_random_u32_below(now - old); 473 474 /* If UBSAN reports an error there, please make sure your compiler 475 * supports -fno-strict-overflow before reporting it that was a bug 476 * in UBSAN, and it has been fixed in GCC-8. 477 */ 478 return atomic_add_return(segs + delta, p_id) - segs; 479 } 480 481 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 482 { 483 u32 hash, id; 484 485 /* Note the following code is not safe, but this is okay. */ 486 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 487 get_random_bytes(&net->ipv4.ip_id_key, 488 sizeof(net->ipv4.ip_id_key)); 489 490 hash = siphash_3u32((__force u32)iph->daddr, 491 (__force u32)iph->saddr, 492 iph->protocol, 493 &net->ipv4.ip_id_key); 494 id = ip_idents_reserve(hash, segs); 495 iph->id = htons(id); 496 } 497 EXPORT_SYMBOL(__ip_select_ident); 498 499 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 500 const struct sock *sk, const struct iphdr *iph, 501 int oif, __u8 tos, u8 prot, u32 mark, 502 int flow_flags) 503 { 504 __u8 scope = RT_SCOPE_UNIVERSE; 505 506 if (sk) { 507 oif = sk->sk_bound_dev_if; 508 mark = READ_ONCE(sk->sk_mark); 509 tos = ip_sock_rt_tos(sk); 510 scope = ip_sock_rt_scope(sk); 511 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 512 sk->sk_protocol; 513 } 514 515 flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope, 516 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 517 sock_net_uid(net, sk)); 518 } 519 520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 521 const struct sock *sk) 522 { 523 const struct net *net = dev_net(skb->dev); 524 const struct iphdr *iph = ip_hdr(skb); 525 int oif = skb->dev->ifindex; 526 u8 prot = iph->protocol; 527 u32 mark = skb->mark; 528 __u8 tos = iph->tos; 529 530 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 531 } 532 533 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 534 { 535 const struct inet_sock *inet = inet_sk(sk); 536 const struct ip_options_rcu *inet_opt; 537 __be32 daddr = inet->inet_daddr; 538 539 rcu_read_lock(); 540 inet_opt = rcu_dereference(inet->inet_opt); 541 if (inet_opt && inet_opt->opt.srr) 542 daddr = inet_opt->opt.faddr; 543 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 544 ip_sock_rt_tos(sk) & IPTOS_RT_MASK, 545 ip_sock_rt_scope(sk), 546 inet_test_bit(HDRINCL, sk) ? 547 IPPROTO_RAW : sk->sk_protocol, 548 inet_sk_flowi_flags(sk), 549 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 550 rcu_read_unlock(); 551 } 552 553 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 554 const struct sk_buff *skb) 555 { 556 if (skb) 557 build_skb_flow_key(fl4, skb, sk); 558 else 559 build_sk_flow_key(fl4, sk); 560 } 561 562 static DEFINE_SPINLOCK(fnhe_lock); 563 564 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 565 { 566 struct rtable *rt; 567 568 rt = rcu_dereference(fnhe->fnhe_rth_input); 569 if (rt) { 570 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 571 dst_dev_put(&rt->dst); 572 dst_release(&rt->dst); 573 } 574 rt = rcu_dereference(fnhe->fnhe_rth_output); 575 if (rt) { 576 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 577 dst_dev_put(&rt->dst); 578 dst_release(&rt->dst); 579 } 580 } 581 582 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 583 { 584 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 585 struct fib_nh_exception *fnhe, *oldest = NULL; 586 587 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 588 fnhe = rcu_dereference_protected(*fnhe_p, 589 lockdep_is_held(&fnhe_lock)); 590 if (!fnhe) 591 break; 592 if (!oldest || 593 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 594 oldest = fnhe; 595 oldest_p = fnhe_p; 596 } 597 } 598 fnhe_flush_routes(oldest); 599 *oldest_p = oldest->fnhe_next; 600 kfree_rcu(oldest, rcu); 601 } 602 603 static u32 fnhe_hashfun(__be32 daddr) 604 { 605 static siphash_aligned_key_t fnhe_hash_key; 606 u64 hval; 607 608 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 609 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 610 return hash_64(hval, FNHE_HASH_SHIFT); 611 } 612 613 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 614 { 615 rt->rt_pmtu = fnhe->fnhe_pmtu; 616 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 617 rt->dst.expires = fnhe->fnhe_expires; 618 619 if (fnhe->fnhe_gw) { 620 rt->rt_flags |= RTCF_REDIRECTED; 621 rt->rt_uses_gateway = 1; 622 rt->rt_gw_family = AF_INET; 623 rt->rt_gw4 = fnhe->fnhe_gw; 624 } 625 } 626 627 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 628 __be32 gw, u32 pmtu, bool lock, 629 unsigned long expires) 630 { 631 struct fnhe_hash_bucket *hash; 632 struct fib_nh_exception *fnhe; 633 struct rtable *rt; 634 u32 genid, hval; 635 unsigned int i; 636 int depth; 637 638 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 639 hval = fnhe_hashfun(daddr); 640 641 spin_lock_bh(&fnhe_lock); 642 643 hash = rcu_dereference(nhc->nhc_exceptions); 644 if (!hash) { 645 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 646 if (!hash) 647 goto out_unlock; 648 rcu_assign_pointer(nhc->nhc_exceptions, hash); 649 } 650 651 hash += hval; 652 653 depth = 0; 654 for (fnhe = rcu_dereference(hash->chain); fnhe; 655 fnhe = rcu_dereference(fnhe->fnhe_next)) { 656 if (fnhe->fnhe_daddr == daddr) 657 break; 658 depth++; 659 } 660 661 if (fnhe) { 662 if (fnhe->fnhe_genid != genid) 663 fnhe->fnhe_genid = genid; 664 if (gw) 665 fnhe->fnhe_gw = gw; 666 if (pmtu) { 667 fnhe->fnhe_pmtu = pmtu; 668 fnhe->fnhe_mtu_locked = lock; 669 } 670 fnhe->fnhe_expires = max(1UL, expires); 671 /* Update all cached dsts too */ 672 rt = rcu_dereference(fnhe->fnhe_rth_input); 673 if (rt) 674 fill_route_from_fnhe(rt, fnhe); 675 rt = rcu_dereference(fnhe->fnhe_rth_output); 676 if (rt) 677 fill_route_from_fnhe(rt, fnhe); 678 } else { 679 /* Randomize max depth to avoid some side channels attacks. */ 680 int max_depth = FNHE_RECLAIM_DEPTH + 681 get_random_u32_below(FNHE_RECLAIM_DEPTH); 682 683 while (depth > max_depth) { 684 fnhe_remove_oldest(hash); 685 depth--; 686 } 687 688 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 689 if (!fnhe) 690 goto out_unlock; 691 692 fnhe->fnhe_next = hash->chain; 693 694 fnhe->fnhe_genid = genid; 695 fnhe->fnhe_daddr = daddr; 696 fnhe->fnhe_gw = gw; 697 fnhe->fnhe_pmtu = pmtu; 698 fnhe->fnhe_mtu_locked = lock; 699 fnhe->fnhe_expires = max(1UL, expires); 700 701 rcu_assign_pointer(hash->chain, fnhe); 702 703 /* Exception created; mark the cached routes for the nexthop 704 * stale, so anyone caching it rechecks if this exception 705 * applies to them. 706 */ 707 rt = rcu_dereference(nhc->nhc_rth_input); 708 if (rt) 709 rt->dst.obsolete = DST_OBSOLETE_KILL; 710 711 for_each_possible_cpu(i) { 712 struct rtable __rcu **prt; 713 714 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 715 rt = rcu_dereference(*prt); 716 if (rt) 717 rt->dst.obsolete = DST_OBSOLETE_KILL; 718 } 719 } 720 721 fnhe->fnhe_stamp = jiffies; 722 723 out_unlock: 724 spin_unlock_bh(&fnhe_lock); 725 } 726 727 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 728 bool kill_route) 729 { 730 __be32 new_gw = icmp_hdr(skb)->un.gateway; 731 __be32 old_gw = ip_hdr(skb)->saddr; 732 struct net_device *dev = skb->dev; 733 struct in_device *in_dev; 734 struct fib_result res; 735 struct neighbour *n; 736 struct net *net; 737 738 switch (icmp_hdr(skb)->code & 7) { 739 case ICMP_REDIR_NET: 740 case ICMP_REDIR_NETTOS: 741 case ICMP_REDIR_HOST: 742 case ICMP_REDIR_HOSTTOS: 743 break; 744 745 default: 746 return; 747 } 748 749 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 750 return; 751 752 in_dev = __in_dev_get_rcu(dev); 753 if (!in_dev) 754 return; 755 756 net = dev_net(dev); 757 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 758 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 759 ipv4_is_zeronet(new_gw)) 760 goto reject_redirect; 761 762 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 763 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 764 goto reject_redirect; 765 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 766 goto reject_redirect; 767 } else { 768 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 769 goto reject_redirect; 770 } 771 772 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 773 if (!n) 774 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 775 if (!IS_ERR(n)) { 776 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 777 neigh_event_send(n, NULL); 778 } else { 779 if (fib_lookup(net, fl4, &res, 0) == 0) { 780 struct fib_nh_common *nhc; 781 782 fib_select_path(net, &res, fl4, skb); 783 nhc = FIB_RES_NHC(res); 784 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 785 0, false, 786 jiffies + ip_rt_gc_timeout); 787 } 788 if (kill_route) 789 rt->dst.obsolete = DST_OBSOLETE_KILL; 790 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 791 } 792 neigh_release(n); 793 } 794 return; 795 796 reject_redirect: 797 #ifdef CONFIG_IP_ROUTE_VERBOSE 798 if (IN_DEV_LOG_MARTIANS(in_dev)) { 799 const struct iphdr *iph = (const struct iphdr *) skb->data; 800 __be32 daddr = iph->daddr; 801 __be32 saddr = iph->saddr; 802 803 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 804 " Advised path = %pI4 -> %pI4\n", 805 &old_gw, dev->name, &new_gw, 806 &saddr, &daddr); 807 } 808 #endif 809 ; 810 } 811 812 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 813 { 814 struct rtable *rt; 815 struct flowi4 fl4; 816 const struct iphdr *iph = (const struct iphdr *) skb->data; 817 struct net *net = dev_net(skb->dev); 818 int oif = skb->dev->ifindex; 819 u8 prot = iph->protocol; 820 u32 mark = skb->mark; 821 __u8 tos = iph->tos; 822 823 rt = dst_rtable(dst); 824 825 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 826 __ip_do_redirect(rt, skb, &fl4, true); 827 } 828 829 static void ipv4_negative_advice(struct sock *sk, 830 struct dst_entry *dst) 831 { 832 struct rtable *rt = dst_rtable(dst); 833 834 if ((dst->obsolete > 0) || 835 (rt->rt_flags & RTCF_REDIRECTED) || 836 rt->dst.expires) 837 sk_dst_reset(sk); 838 } 839 840 /* 841 * Algorithm: 842 * 1. The first ip_rt_redirect_number redirects are sent 843 * with exponential backoff, then we stop sending them at all, 844 * assuming that the host ignores our redirects. 845 * 2. If we did not see packets requiring redirects 846 * during ip_rt_redirect_silence, we assume that the host 847 * forgot redirected route and start to send redirects again. 848 * 849 * This algorithm is much cheaper and more intelligent than dumb load limiting 850 * in icmp.c. 851 * 852 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 853 * and "frag. need" (breaks PMTU discovery) in icmp.c. 854 */ 855 856 void ip_rt_send_redirect(struct sk_buff *skb) 857 { 858 struct rtable *rt = skb_rtable(skb); 859 struct in_device *in_dev; 860 struct inet_peer *peer; 861 struct net *net; 862 int log_martians; 863 int vif; 864 865 rcu_read_lock(); 866 in_dev = __in_dev_get_rcu(rt->dst.dev); 867 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 868 rcu_read_unlock(); 869 return; 870 } 871 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 872 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 873 rcu_read_unlock(); 874 875 net = dev_net(rt->dst.dev); 876 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 877 if (!peer) { 878 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 879 rt_nexthop(rt, ip_hdr(skb)->daddr)); 880 return; 881 } 882 883 /* No redirected packets during ip_rt_redirect_silence; 884 * reset the algorithm. 885 */ 886 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 887 peer->rate_tokens = 0; 888 peer->n_redirects = 0; 889 } 890 891 /* Too many ignored redirects; do not send anything 892 * set dst.rate_last to the last seen redirected packet. 893 */ 894 if (peer->n_redirects >= ip_rt_redirect_number) { 895 peer->rate_last = jiffies; 896 goto out_put_peer; 897 } 898 899 /* Check for load limit; set rate_last to the latest sent 900 * redirect. 901 */ 902 if (peer->n_redirects == 0 || 903 time_after(jiffies, 904 (peer->rate_last + 905 (ip_rt_redirect_load << peer->n_redirects)))) { 906 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 907 908 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 909 peer->rate_last = jiffies; 910 ++peer->n_redirects; 911 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 912 peer->n_redirects == ip_rt_redirect_number) 913 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 914 &ip_hdr(skb)->saddr, inet_iif(skb), 915 &ip_hdr(skb)->daddr, &gw); 916 } 917 out_put_peer: 918 inet_putpeer(peer); 919 } 920 921 static int ip_error(struct sk_buff *skb) 922 { 923 struct rtable *rt = skb_rtable(skb); 924 struct net_device *dev = skb->dev; 925 struct in_device *in_dev; 926 struct inet_peer *peer; 927 unsigned long now; 928 struct net *net; 929 SKB_DR(reason); 930 bool send; 931 int code; 932 933 if (netif_is_l3_master(skb->dev)) { 934 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 935 if (!dev) 936 goto out; 937 } 938 939 in_dev = __in_dev_get_rcu(dev); 940 941 /* IP on this device is disabled. */ 942 if (!in_dev) 943 goto out; 944 945 net = dev_net(rt->dst.dev); 946 if (!IN_DEV_FORWARD(in_dev)) { 947 switch (rt->dst.error) { 948 case EHOSTUNREACH: 949 SKB_DR_SET(reason, IP_INADDRERRORS); 950 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 951 break; 952 953 case ENETUNREACH: 954 SKB_DR_SET(reason, IP_INNOROUTES); 955 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 956 break; 957 } 958 goto out; 959 } 960 961 switch (rt->dst.error) { 962 case EINVAL: 963 default: 964 goto out; 965 case EHOSTUNREACH: 966 code = ICMP_HOST_UNREACH; 967 break; 968 case ENETUNREACH: 969 code = ICMP_NET_UNREACH; 970 SKB_DR_SET(reason, IP_INNOROUTES); 971 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 972 break; 973 case EACCES: 974 code = ICMP_PKT_FILTERED; 975 break; 976 } 977 978 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 979 l3mdev_master_ifindex(skb->dev), 1); 980 981 send = true; 982 if (peer) { 983 now = jiffies; 984 peer->rate_tokens += now - peer->rate_last; 985 if (peer->rate_tokens > ip_rt_error_burst) 986 peer->rate_tokens = ip_rt_error_burst; 987 peer->rate_last = now; 988 if (peer->rate_tokens >= ip_rt_error_cost) 989 peer->rate_tokens -= ip_rt_error_cost; 990 else 991 send = false; 992 inet_putpeer(peer); 993 } 994 if (send) 995 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 996 997 out: kfree_skb_reason(skb, reason); 998 return 0; 999 } 1000 1001 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1002 { 1003 struct dst_entry *dst = &rt->dst; 1004 struct net *net = dev_net(dst->dev); 1005 struct fib_result res; 1006 bool lock = false; 1007 u32 old_mtu; 1008 1009 if (ip_mtu_locked(dst)) 1010 return; 1011 1012 old_mtu = ipv4_mtu(dst); 1013 if (old_mtu < mtu) 1014 return; 1015 1016 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1017 lock = true; 1018 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1019 } 1020 1021 if (rt->rt_pmtu == mtu && !lock && 1022 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1023 return; 1024 1025 rcu_read_lock(); 1026 if (fib_lookup(net, fl4, &res, 0) == 0) { 1027 struct fib_nh_common *nhc; 1028 1029 fib_select_path(net, &res, fl4, NULL); 1030 nhc = FIB_RES_NHC(res); 1031 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1032 jiffies + net->ipv4.ip_rt_mtu_expires); 1033 } 1034 rcu_read_unlock(); 1035 } 1036 1037 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1038 struct sk_buff *skb, u32 mtu, 1039 bool confirm_neigh) 1040 { 1041 struct rtable *rt = dst_rtable(dst); 1042 struct flowi4 fl4; 1043 1044 ip_rt_build_flow_key(&fl4, sk, skb); 1045 1046 /* Don't make lookup fail for bridged encapsulations */ 1047 if (skb && netif_is_any_bridge_port(skb->dev)) 1048 fl4.flowi4_oif = 0; 1049 1050 __ip_rt_update_pmtu(rt, &fl4, mtu); 1051 } 1052 1053 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1054 int oif, u8 protocol) 1055 { 1056 const struct iphdr *iph = (const struct iphdr *)skb->data; 1057 struct flowi4 fl4; 1058 struct rtable *rt; 1059 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1060 1061 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1062 0); 1063 rt = __ip_route_output_key(net, &fl4); 1064 if (!IS_ERR(rt)) { 1065 __ip_rt_update_pmtu(rt, &fl4, mtu); 1066 ip_rt_put(rt); 1067 } 1068 } 1069 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1070 1071 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1072 { 1073 const struct iphdr *iph = (const struct iphdr *)skb->data; 1074 struct flowi4 fl4; 1075 struct rtable *rt; 1076 1077 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1078 1079 if (!fl4.flowi4_mark) 1080 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1081 1082 rt = __ip_route_output_key(sock_net(sk), &fl4); 1083 if (!IS_ERR(rt)) { 1084 __ip_rt_update_pmtu(rt, &fl4, mtu); 1085 ip_rt_put(rt); 1086 } 1087 } 1088 1089 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1090 { 1091 const struct iphdr *iph = (const struct iphdr *)skb->data; 1092 struct flowi4 fl4; 1093 struct rtable *rt; 1094 struct dst_entry *odst = NULL; 1095 bool new = false; 1096 struct net *net = sock_net(sk); 1097 1098 bh_lock_sock(sk); 1099 1100 if (!ip_sk_accept_pmtu(sk)) 1101 goto out; 1102 1103 odst = sk_dst_get(sk); 1104 1105 if (sock_owned_by_user(sk) || !odst) { 1106 __ipv4_sk_update_pmtu(skb, sk, mtu); 1107 goto out; 1108 } 1109 1110 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1111 1112 rt = dst_rtable(odst); 1113 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1114 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1115 if (IS_ERR(rt)) 1116 goto out; 1117 1118 new = true; 1119 } 1120 1121 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1122 1123 if (!dst_check(&rt->dst, 0)) { 1124 if (new) 1125 dst_release(&rt->dst); 1126 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 if (new) 1135 sk_dst_set(sk, &rt->dst); 1136 1137 out: 1138 bh_unlock_sock(sk); 1139 dst_release(odst); 1140 } 1141 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1142 1143 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1144 int oif, u8 protocol) 1145 { 1146 const struct iphdr *iph = (const struct iphdr *)skb->data; 1147 struct flowi4 fl4; 1148 struct rtable *rt; 1149 1150 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1151 rt = __ip_route_output_key(net, &fl4); 1152 if (!IS_ERR(rt)) { 1153 __ip_do_redirect(rt, skb, &fl4, false); 1154 ip_rt_put(rt); 1155 } 1156 } 1157 EXPORT_SYMBOL_GPL(ipv4_redirect); 1158 1159 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1160 { 1161 const struct iphdr *iph = (const struct iphdr *)skb->data; 1162 struct flowi4 fl4; 1163 struct rtable *rt; 1164 struct net *net = sock_net(sk); 1165 1166 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1167 rt = __ip_route_output_key(net, &fl4); 1168 if (!IS_ERR(rt)) { 1169 __ip_do_redirect(rt, skb, &fl4, false); 1170 ip_rt_put(rt); 1171 } 1172 } 1173 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1174 1175 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1176 u32 cookie) 1177 { 1178 struct rtable *rt = dst_rtable(dst); 1179 1180 /* All IPV4 dsts are created with ->obsolete set to the value 1181 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1182 * into this function always. 1183 * 1184 * When a PMTU/redirect information update invalidates a route, 1185 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1186 * DST_OBSOLETE_DEAD. 1187 */ 1188 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1189 return NULL; 1190 return dst; 1191 } 1192 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1193 1194 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1195 { 1196 struct net_device *dev; 1197 struct ip_options opt; 1198 int res; 1199 1200 /* Recompile ip options since IPCB may not be valid anymore. 1201 * Also check we have a reasonable ipv4 header. 1202 */ 1203 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1204 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1205 return; 1206 1207 memset(&opt, 0, sizeof(opt)); 1208 if (ip_hdr(skb)->ihl > 5) { 1209 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1210 return; 1211 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1212 1213 rcu_read_lock(); 1214 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1215 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); 1216 rcu_read_unlock(); 1217 1218 if (res) 1219 return; 1220 } 1221 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1222 } 1223 1224 static void ipv4_link_failure(struct sk_buff *skb) 1225 { 1226 struct rtable *rt; 1227 1228 ipv4_send_dest_unreach(skb); 1229 1230 rt = skb_rtable(skb); 1231 if (rt) 1232 dst_set_expires(&rt->dst, 0); 1233 } 1234 1235 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1236 { 1237 pr_debug("%s: %pI4 -> %pI4, %s\n", 1238 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1239 skb->dev ? skb->dev->name : "?"); 1240 kfree_skb(skb); 1241 WARN_ON(1); 1242 return 0; 1243 } 1244 1245 /* 1246 * We do not cache source address of outgoing interface, 1247 * because it is used only by IP RR, TS and SRR options, 1248 * so that it out of fast path. 1249 * 1250 * BTW remember: "addr" is allowed to be not aligned 1251 * in IP options! 1252 */ 1253 1254 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1255 { 1256 __be32 src; 1257 1258 if (rt_is_output_route(rt)) 1259 src = ip_hdr(skb)->saddr; 1260 else { 1261 struct fib_result res; 1262 struct iphdr *iph = ip_hdr(skb); 1263 struct flowi4 fl4 = { 1264 .daddr = iph->daddr, 1265 .saddr = iph->saddr, 1266 .flowi4_tos = RT_TOS(iph->tos), 1267 .flowi4_oif = rt->dst.dev->ifindex, 1268 .flowi4_iif = skb->dev->ifindex, 1269 .flowi4_mark = skb->mark, 1270 }; 1271 1272 rcu_read_lock(); 1273 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1274 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1275 else 1276 src = inet_select_addr(rt->dst.dev, 1277 rt_nexthop(rt, iph->daddr), 1278 RT_SCOPE_UNIVERSE); 1279 rcu_read_unlock(); 1280 } 1281 memcpy(addr, &src, 4); 1282 } 1283 1284 #ifdef CONFIG_IP_ROUTE_CLASSID 1285 static void set_class_tag(struct rtable *rt, u32 tag) 1286 { 1287 if (!(rt->dst.tclassid & 0xFFFF)) 1288 rt->dst.tclassid |= tag & 0xFFFF; 1289 if (!(rt->dst.tclassid & 0xFFFF0000)) 1290 rt->dst.tclassid |= tag & 0xFFFF0000; 1291 } 1292 #endif 1293 1294 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1295 { 1296 struct net *net = dev_net(dst->dev); 1297 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1298 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1299 net->ipv4.ip_rt_min_advmss); 1300 1301 return min(advmss, IPV4_MAX_PMTU - header_size); 1302 } 1303 1304 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1305 { 1306 return ip_dst_mtu_maybe_forward(dst, false); 1307 } 1308 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1309 1310 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1311 { 1312 struct fnhe_hash_bucket *hash; 1313 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1314 u32 hval = fnhe_hashfun(daddr); 1315 1316 spin_lock_bh(&fnhe_lock); 1317 1318 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1319 lockdep_is_held(&fnhe_lock)); 1320 hash += hval; 1321 1322 fnhe_p = &hash->chain; 1323 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1324 while (fnhe) { 1325 if (fnhe->fnhe_daddr == daddr) { 1326 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1327 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1328 /* set fnhe_daddr to 0 to ensure it won't bind with 1329 * new dsts in rt_bind_exception(). 1330 */ 1331 fnhe->fnhe_daddr = 0; 1332 fnhe_flush_routes(fnhe); 1333 kfree_rcu(fnhe, rcu); 1334 break; 1335 } 1336 fnhe_p = &fnhe->fnhe_next; 1337 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1338 lockdep_is_held(&fnhe_lock)); 1339 } 1340 1341 spin_unlock_bh(&fnhe_lock); 1342 } 1343 1344 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1345 __be32 daddr) 1346 { 1347 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1348 struct fib_nh_exception *fnhe; 1349 u32 hval; 1350 1351 if (!hash) 1352 return NULL; 1353 1354 hval = fnhe_hashfun(daddr); 1355 1356 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1357 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1358 if (fnhe->fnhe_daddr == daddr) { 1359 if (fnhe->fnhe_expires && 1360 time_after(jiffies, fnhe->fnhe_expires)) { 1361 ip_del_fnhe(nhc, daddr); 1362 break; 1363 } 1364 return fnhe; 1365 } 1366 } 1367 return NULL; 1368 } 1369 1370 /* MTU selection: 1371 * 1. mtu on route is locked - use it 1372 * 2. mtu from nexthop exception 1373 * 3. mtu from egress device 1374 */ 1375 1376 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1377 { 1378 struct fib_nh_common *nhc = res->nhc; 1379 struct net_device *dev = nhc->nhc_dev; 1380 struct fib_info *fi = res->fi; 1381 u32 mtu = 0; 1382 1383 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1384 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1385 mtu = fi->fib_mtu; 1386 1387 if (likely(!mtu)) { 1388 struct fib_nh_exception *fnhe; 1389 1390 fnhe = find_exception(nhc, daddr); 1391 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1392 mtu = fnhe->fnhe_pmtu; 1393 } 1394 1395 if (likely(!mtu)) 1396 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1397 1398 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1399 } 1400 1401 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1402 __be32 daddr, const bool do_cache) 1403 { 1404 bool ret = false; 1405 1406 spin_lock_bh(&fnhe_lock); 1407 1408 if (daddr == fnhe->fnhe_daddr) { 1409 struct rtable __rcu **porig; 1410 struct rtable *orig; 1411 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1412 1413 if (rt_is_input_route(rt)) 1414 porig = &fnhe->fnhe_rth_input; 1415 else 1416 porig = &fnhe->fnhe_rth_output; 1417 orig = rcu_dereference(*porig); 1418 1419 if (fnhe->fnhe_genid != genid) { 1420 fnhe->fnhe_genid = genid; 1421 fnhe->fnhe_gw = 0; 1422 fnhe->fnhe_pmtu = 0; 1423 fnhe->fnhe_expires = 0; 1424 fnhe->fnhe_mtu_locked = false; 1425 fnhe_flush_routes(fnhe); 1426 orig = NULL; 1427 } 1428 fill_route_from_fnhe(rt, fnhe); 1429 if (!rt->rt_gw4) { 1430 rt->rt_gw4 = daddr; 1431 rt->rt_gw_family = AF_INET; 1432 } 1433 1434 if (do_cache) { 1435 dst_hold(&rt->dst); 1436 rcu_assign_pointer(*porig, rt); 1437 if (orig) { 1438 dst_dev_put(&orig->dst); 1439 dst_release(&orig->dst); 1440 } 1441 ret = true; 1442 } 1443 1444 fnhe->fnhe_stamp = jiffies; 1445 } 1446 spin_unlock_bh(&fnhe_lock); 1447 1448 return ret; 1449 } 1450 1451 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1452 { 1453 struct rtable *orig, *prev, **p; 1454 bool ret = true; 1455 1456 if (rt_is_input_route(rt)) { 1457 p = (struct rtable **)&nhc->nhc_rth_input; 1458 } else { 1459 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1460 } 1461 orig = *p; 1462 1463 /* hold dst before doing cmpxchg() to avoid race condition 1464 * on this dst 1465 */ 1466 dst_hold(&rt->dst); 1467 prev = cmpxchg(p, orig, rt); 1468 if (prev == orig) { 1469 if (orig) { 1470 rt_add_uncached_list(orig); 1471 dst_release(&orig->dst); 1472 } 1473 } else { 1474 dst_release(&rt->dst); 1475 ret = false; 1476 } 1477 1478 return ret; 1479 } 1480 1481 struct uncached_list { 1482 spinlock_t lock; 1483 struct list_head head; 1484 struct list_head quarantine; 1485 }; 1486 1487 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1488 1489 void rt_add_uncached_list(struct rtable *rt) 1490 { 1491 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1492 1493 rt->dst.rt_uncached_list = ul; 1494 1495 spin_lock_bh(&ul->lock); 1496 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1497 spin_unlock_bh(&ul->lock); 1498 } 1499 1500 void rt_del_uncached_list(struct rtable *rt) 1501 { 1502 if (!list_empty(&rt->dst.rt_uncached)) { 1503 struct uncached_list *ul = rt->dst.rt_uncached_list; 1504 1505 spin_lock_bh(&ul->lock); 1506 list_del_init(&rt->dst.rt_uncached); 1507 spin_unlock_bh(&ul->lock); 1508 } 1509 } 1510 1511 static void ipv4_dst_destroy(struct dst_entry *dst) 1512 { 1513 ip_dst_metrics_put(dst); 1514 rt_del_uncached_list(dst_rtable(dst)); 1515 } 1516 1517 void rt_flush_dev(struct net_device *dev) 1518 { 1519 struct rtable *rt, *safe; 1520 int cpu; 1521 1522 for_each_possible_cpu(cpu) { 1523 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1524 1525 if (list_empty(&ul->head)) 1526 continue; 1527 1528 spin_lock_bh(&ul->lock); 1529 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1530 if (rt->dst.dev != dev) 1531 continue; 1532 rt->dst.dev = blackhole_netdev; 1533 netdev_ref_replace(dev, blackhole_netdev, 1534 &rt->dst.dev_tracker, GFP_ATOMIC); 1535 list_move(&rt->dst.rt_uncached, &ul->quarantine); 1536 } 1537 spin_unlock_bh(&ul->lock); 1538 } 1539 } 1540 1541 static bool rt_cache_valid(const struct rtable *rt) 1542 { 1543 return rt && 1544 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1545 !rt_is_expired(rt); 1546 } 1547 1548 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1549 const struct fib_result *res, 1550 struct fib_nh_exception *fnhe, 1551 struct fib_info *fi, u16 type, u32 itag, 1552 const bool do_cache) 1553 { 1554 bool cached = false; 1555 1556 if (fi) { 1557 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1558 1559 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1560 rt->rt_uses_gateway = 1; 1561 rt->rt_gw_family = nhc->nhc_gw_family; 1562 /* only INET and INET6 are supported */ 1563 if (likely(nhc->nhc_gw_family == AF_INET)) 1564 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1565 else 1566 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1567 } 1568 1569 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1570 1571 #ifdef CONFIG_IP_ROUTE_CLASSID 1572 if (nhc->nhc_family == AF_INET) { 1573 struct fib_nh *nh; 1574 1575 nh = container_of(nhc, struct fib_nh, nh_common); 1576 rt->dst.tclassid = nh->nh_tclassid; 1577 } 1578 #endif 1579 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1580 if (unlikely(fnhe)) 1581 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1582 else if (do_cache) 1583 cached = rt_cache_route(nhc, rt); 1584 if (unlikely(!cached)) { 1585 /* Routes we intend to cache in nexthop exception or 1586 * FIB nexthop have the DST_NOCACHE bit clear. 1587 * However, if we are unsuccessful at storing this 1588 * route into the cache we really need to set it. 1589 */ 1590 if (!rt->rt_gw4) { 1591 rt->rt_gw_family = AF_INET; 1592 rt->rt_gw4 = daddr; 1593 } 1594 rt_add_uncached_list(rt); 1595 } 1596 } else 1597 rt_add_uncached_list(rt); 1598 1599 #ifdef CONFIG_IP_ROUTE_CLASSID 1600 #ifdef CONFIG_IP_MULTIPLE_TABLES 1601 set_class_tag(rt, res->tclassid); 1602 #endif 1603 set_class_tag(rt, itag); 1604 #endif 1605 } 1606 1607 struct rtable *rt_dst_alloc(struct net_device *dev, 1608 unsigned int flags, u16 type, 1609 bool noxfrm) 1610 { 1611 struct rtable *rt; 1612 1613 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1614 (noxfrm ? DST_NOXFRM : 0)); 1615 1616 if (rt) { 1617 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1618 rt->rt_flags = flags; 1619 rt->rt_type = type; 1620 rt->rt_is_input = 0; 1621 rt->rt_iif = 0; 1622 rt->rt_pmtu = 0; 1623 rt->rt_mtu_locked = 0; 1624 rt->rt_uses_gateway = 0; 1625 rt->rt_gw_family = 0; 1626 rt->rt_gw4 = 0; 1627 1628 rt->dst.output = ip_output; 1629 if (flags & RTCF_LOCAL) 1630 rt->dst.input = ip_local_deliver; 1631 } 1632 1633 return rt; 1634 } 1635 EXPORT_SYMBOL(rt_dst_alloc); 1636 1637 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1638 { 1639 struct rtable *new_rt; 1640 1641 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1642 rt->dst.flags); 1643 1644 if (new_rt) { 1645 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1646 new_rt->rt_flags = rt->rt_flags; 1647 new_rt->rt_type = rt->rt_type; 1648 new_rt->rt_is_input = rt->rt_is_input; 1649 new_rt->rt_iif = rt->rt_iif; 1650 new_rt->rt_pmtu = rt->rt_pmtu; 1651 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1652 new_rt->rt_gw_family = rt->rt_gw_family; 1653 if (rt->rt_gw_family == AF_INET) 1654 new_rt->rt_gw4 = rt->rt_gw4; 1655 else if (rt->rt_gw_family == AF_INET6) 1656 new_rt->rt_gw6 = rt->rt_gw6; 1657 1658 new_rt->dst.input = rt->dst.input; 1659 new_rt->dst.output = rt->dst.output; 1660 new_rt->dst.error = rt->dst.error; 1661 new_rt->dst.lastuse = jiffies; 1662 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1663 } 1664 return new_rt; 1665 } 1666 EXPORT_SYMBOL(rt_dst_clone); 1667 1668 /* called in rcu_read_lock() section */ 1669 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1670 u8 tos, struct net_device *dev, 1671 struct in_device *in_dev, u32 *itag) 1672 { 1673 int err; 1674 1675 /* Primary sanity checks. */ 1676 if (!in_dev) 1677 return -EINVAL; 1678 1679 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1680 skb->protocol != htons(ETH_P_IP)) 1681 return -EINVAL; 1682 1683 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1684 return -EINVAL; 1685 1686 if (ipv4_is_zeronet(saddr)) { 1687 if (!ipv4_is_local_multicast(daddr) && 1688 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1689 return -EINVAL; 1690 } else { 1691 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1692 in_dev, itag); 1693 if (err < 0) 1694 return err; 1695 } 1696 return 0; 1697 } 1698 1699 /* called in rcu_read_lock() section */ 1700 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1701 u8 tos, struct net_device *dev, int our) 1702 { 1703 struct in_device *in_dev = __in_dev_get_rcu(dev); 1704 unsigned int flags = RTCF_MULTICAST; 1705 struct rtable *rth; 1706 u32 itag = 0; 1707 int err; 1708 1709 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1710 if (err) 1711 return err; 1712 1713 if (our) 1714 flags |= RTCF_LOCAL; 1715 1716 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1717 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1718 1719 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1720 false); 1721 if (!rth) 1722 return -ENOBUFS; 1723 1724 #ifdef CONFIG_IP_ROUTE_CLASSID 1725 rth->dst.tclassid = itag; 1726 #endif 1727 rth->dst.output = ip_rt_bug; 1728 rth->rt_is_input= 1; 1729 1730 #ifdef CONFIG_IP_MROUTE 1731 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1732 rth->dst.input = ip_mr_input; 1733 #endif 1734 RT_CACHE_STAT_INC(in_slow_mc); 1735 1736 skb_dst_drop(skb); 1737 skb_dst_set(skb, &rth->dst); 1738 return 0; 1739 } 1740 1741 1742 static void ip_handle_martian_source(struct net_device *dev, 1743 struct in_device *in_dev, 1744 struct sk_buff *skb, 1745 __be32 daddr, 1746 __be32 saddr) 1747 { 1748 RT_CACHE_STAT_INC(in_martian_src); 1749 #ifdef CONFIG_IP_ROUTE_VERBOSE 1750 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1751 /* 1752 * RFC1812 recommendation, if source is martian, 1753 * the only hint is MAC header. 1754 */ 1755 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1756 &daddr, &saddr, dev->name); 1757 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1758 print_hex_dump(KERN_WARNING, "ll header: ", 1759 DUMP_PREFIX_OFFSET, 16, 1, 1760 skb_mac_header(skb), 1761 dev->hard_header_len, false); 1762 } 1763 } 1764 #endif 1765 } 1766 1767 /* called in rcu_read_lock() section */ 1768 static int __mkroute_input(struct sk_buff *skb, 1769 const struct fib_result *res, 1770 struct in_device *in_dev, 1771 __be32 daddr, __be32 saddr, u32 tos) 1772 { 1773 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1774 struct net_device *dev = nhc->nhc_dev; 1775 struct fib_nh_exception *fnhe; 1776 struct rtable *rth; 1777 int err; 1778 struct in_device *out_dev; 1779 bool do_cache; 1780 u32 itag = 0; 1781 1782 /* get a working reference to the output device */ 1783 out_dev = __in_dev_get_rcu(dev); 1784 if (!out_dev) { 1785 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1786 return -EINVAL; 1787 } 1788 1789 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1790 in_dev->dev, in_dev, &itag); 1791 if (err < 0) { 1792 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1793 saddr); 1794 1795 goto cleanup; 1796 } 1797 1798 do_cache = res->fi && !itag; 1799 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1800 skb->protocol == htons(ETH_P_IP)) { 1801 __be32 gw; 1802 1803 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1804 if (IN_DEV_SHARED_MEDIA(out_dev) || 1805 inet_addr_onlink(out_dev, saddr, gw)) 1806 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1807 } 1808 1809 if (skb->protocol != htons(ETH_P_IP)) { 1810 /* Not IP (i.e. ARP). Do not create route, if it is 1811 * invalid for proxy arp. DNAT routes are always valid. 1812 * 1813 * Proxy arp feature have been extended to allow, ARP 1814 * replies back to the same interface, to support 1815 * Private VLAN switch technologies. See arp.c. 1816 */ 1817 if (out_dev == in_dev && 1818 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1819 err = -EINVAL; 1820 goto cleanup; 1821 } 1822 } 1823 1824 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1825 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1826 1827 fnhe = find_exception(nhc, daddr); 1828 if (do_cache) { 1829 if (fnhe) 1830 rth = rcu_dereference(fnhe->fnhe_rth_input); 1831 else 1832 rth = rcu_dereference(nhc->nhc_rth_input); 1833 if (rt_cache_valid(rth)) { 1834 skb_dst_set_noref(skb, &rth->dst); 1835 goto out; 1836 } 1837 } 1838 1839 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1840 IN_DEV_ORCONF(out_dev, NOXFRM)); 1841 if (!rth) { 1842 err = -ENOBUFS; 1843 goto cleanup; 1844 } 1845 1846 rth->rt_is_input = 1; 1847 RT_CACHE_STAT_INC(in_slow_tot); 1848 1849 rth->dst.input = ip_forward; 1850 1851 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1852 do_cache); 1853 lwtunnel_set_redirect(&rth->dst); 1854 skb_dst_set(skb, &rth->dst); 1855 out: 1856 err = 0; 1857 cleanup: 1858 return err; 1859 } 1860 1861 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1862 /* To make ICMP packets follow the right flow, the multipath hash is 1863 * calculated from the inner IP addresses. 1864 */ 1865 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1866 struct flow_keys *hash_keys) 1867 { 1868 const struct iphdr *outer_iph = ip_hdr(skb); 1869 const struct iphdr *key_iph = outer_iph; 1870 const struct iphdr *inner_iph; 1871 const struct icmphdr *icmph; 1872 struct iphdr _inner_iph; 1873 struct icmphdr _icmph; 1874 1875 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1876 goto out; 1877 1878 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1879 goto out; 1880 1881 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1882 &_icmph); 1883 if (!icmph) 1884 goto out; 1885 1886 if (!icmp_is_err(icmph->type)) 1887 goto out; 1888 1889 inner_iph = skb_header_pointer(skb, 1890 outer_iph->ihl * 4 + sizeof(_icmph), 1891 sizeof(_inner_iph), &_inner_iph); 1892 if (!inner_iph) 1893 goto out; 1894 1895 key_iph = inner_iph; 1896 out: 1897 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1898 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1899 } 1900 1901 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1902 const struct sk_buff *skb, 1903 bool *p_has_inner) 1904 { 1905 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1906 struct flow_keys keys, hash_keys; 1907 1908 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1909 return 0; 1910 1911 memset(&hash_keys, 0, sizeof(hash_keys)); 1912 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1913 1914 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1915 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1916 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1917 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1918 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1919 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1920 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1921 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1922 hash_keys.ports.src = keys.ports.src; 1923 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1924 hash_keys.ports.dst = keys.ports.dst; 1925 1926 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1927 return flow_hash_from_keys(&hash_keys); 1928 } 1929 1930 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1931 const struct sk_buff *skb, 1932 bool has_inner) 1933 { 1934 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1935 struct flow_keys keys, hash_keys; 1936 1937 /* We assume the packet carries an encapsulation, but if none was 1938 * encountered during dissection of the outer flow, then there is no 1939 * point in calling the flow dissector again. 1940 */ 1941 if (!has_inner) 1942 return 0; 1943 1944 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1945 return 0; 1946 1947 memset(&hash_keys, 0, sizeof(hash_keys)); 1948 skb_flow_dissect_flow_keys(skb, &keys, 0); 1949 1950 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1951 return 0; 1952 1953 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1954 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1955 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1956 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1957 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1958 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1959 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1960 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1961 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1962 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1963 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1964 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1965 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1966 hash_keys.tags.flow_label = keys.tags.flow_label; 1967 } 1968 1969 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1970 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1971 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1972 hash_keys.ports.src = keys.ports.src; 1973 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1974 hash_keys.ports.dst = keys.ports.dst; 1975 1976 return flow_hash_from_keys(&hash_keys); 1977 } 1978 1979 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1980 const struct sk_buff *skb) 1981 { 1982 u32 mhash, mhash_inner; 1983 bool has_inner = true; 1984 1985 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 1986 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 1987 1988 return jhash_2words(mhash, mhash_inner, 0); 1989 } 1990 1991 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 1992 const struct flowi4 *fl4) 1993 { 1994 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1995 struct flow_keys hash_keys; 1996 1997 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1998 return 0; 1999 2000 memset(&hash_keys, 0, sizeof(hash_keys)); 2001 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2002 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2003 hash_keys.addrs.v4addrs.src = fl4->saddr; 2004 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2005 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2006 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2007 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2008 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2009 hash_keys.ports.src = fl4->fl4_sport; 2010 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2011 hash_keys.ports.dst = fl4->fl4_dport; 2012 2013 return flow_hash_from_keys(&hash_keys); 2014 } 2015 2016 /* if skb is set it will be used and fl4 can be NULL */ 2017 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2018 const struct sk_buff *skb, struct flow_keys *flkeys) 2019 { 2020 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2021 struct flow_keys hash_keys; 2022 u32 mhash = 0; 2023 2024 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2025 case 0: 2026 memset(&hash_keys, 0, sizeof(hash_keys)); 2027 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2028 if (skb) { 2029 ip_multipath_l3_keys(skb, &hash_keys); 2030 } else { 2031 hash_keys.addrs.v4addrs.src = fl4->saddr; 2032 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2033 } 2034 mhash = flow_hash_from_keys(&hash_keys); 2035 break; 2036 case 1: 2037 /* skb is currently provided only when forwarding */ 2038 if (skb) { 2039 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2040 struct flow_keys keys; 2041 2042 /* short-circuit if we already have L4 hash present */ 2043 if (skb->l4_hash) 2044 return skb_get_hash_raw(skb) >> 1; 2045 2046 memset(&hash_keys, 0, sizeof(hash_keys)); 2047 2048 if (!flkeys) { 2049 skb_flow_dissect_flow_keys(skb, &keys, flag); 2050 flkeys = &keys; 2051 } 2052 2053 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2054 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2055 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2056 hash_keys.ports.src = flkeys->ports.src; 2057 hash_keys.ports.dst = flkeys->ports.dst; 2058 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2059 } else { 2060 memset(&hash_keys, 0, sizeof(hash_keys)); 2061 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2062 hash_keys.addrs.v4addrs.src = fl4->saddr; 2063 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2064 hash_keys.ports.src = fl4->fl4_sport; 2065 hash_keys.ports.dst = fl4->fl4_dport; 2066 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2067 } 2068 mhash = flow_hash_from_keys(&hash_keys); 2069 break; 2070 case 2: 2071 memset(&hash_keys, 0, sizeof(hash_keys)); 2072 /* skb is currently provided only when forwarding */ 2073 if (skb) { 2074 struct flow_keys keys; 2075 2076 skb_flow_dissect_flow_keys(skb, &keys, 0); 2077 /* Inner can be v4 or v6 */ 2078 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2079 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2080 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2081 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2082 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2083 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2084 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2085 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2086 hash_keys.tags.flow_label = keys.tags.flow_label; 2087 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2088 } else { 2089 /* Same as case 0 */ 2090 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2091 ip_multipath_l3_keys(skb, &hash_keys); 2092 } 2093 } else { 2094 /* Same as case 0 */ 2095 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2096 hash_keys.addrs.v4addrs.src = fl4->saddr; 2097 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2098 } 2099 mhash = flow_hash_from_keys(&hash_keys); 2100 break; 2101 case 3: 2102 if (skb) 2103 mhash = fib_multipath_custom_hash_skb(net, skb); 2104 else 2105 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2106 break; 2107 } 2108 2109 if (multipath_hash) 2110 mhash = jhash_2words(mhash, multipath_hash, 0); 2111 2112 return mhash >> 1; 2113 } 2114 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2115 2116 static int ip_mkroute_input(struct sk_buff *skb, 2117 struct fib_result *res, 2118 struct in_device *in_dev, 2119 __be32 daddr, __be32 saddr, u32 tos, 2120 struct flow_keys *hkeys) 2121 { 2122 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2123 if (res->fi && fib_info_num_path(res->fi) > 1) { 2124 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2125 2126 fib_select_multipath(res, h); 2127 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2128 } 2129 #endif 2130 2131 /* create a routing cache entry */ 2132 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2133 } 2134 2135 /* Implements all the saddr-related checks as ip_route_input_slow(), 2136 * assuming daddr is valid and the destination is not a local broadcast one. 2137 * Uses the provided hint instead of performing a route lookup. 2138 */ 2139 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2140 u8 tos, struct net_device *dev, 2141 const struct sk_buff *hint) 2142 { 2143 struct in_device *in_dev = __in_dev_get_rcu(dev); 2144 struct rtable *rt = skb_rtable(hint); 2145 struct net *net = dev_net(dev); 2146 int err = -EINVAL; 2147 u32 tag = 0; 2148 2149 if (!in_dev) 2150 return -EINVAL; 2151 2152 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2153 goto martian_source; 2154 2155 if (ipv4_is_zeronet(saddr)) 2156 goto martian_source; 2157 2158 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2159 goto martian_source; 2160 2161 if (rt->rt_type != RTN_LOCAL) 2162 goto skip_validate_source; 2163 2164 tos &= IPTOS_RT_MASK; 2165 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2166 if (err < 0) 2167 goto martian_source; 2168 2169 skip_validate_source: 2170 skb_dst_copy(skb, hint); 2171 return 0; 2172 2173 martian_source: 2174 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2175 return err; 2176 } 2177 2178 /* get device for dst_alloc with local routes */ 2179 static struct net_device *ip_rt_get_dev(struct net *net, 2180 const struct fib_result *res) 2181 { 2182 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2183 struct net_device *dev = NULL; 2184 2185 if (nhc) 2186 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2187 2188 return dev ? : net->loopback_dev; 2189 } 2190 2191 /* 2192 * NOTE. We drop all the packets that has local source 2193 * addresses, because every properly looped back packet 2194 * must have correct destination already attached by output routine. 2195 * Changes in the enforced policies must be applied also to 2196 * ip_route_use_hint(). 2197 * 2198 * Such approach solves two big problems: 2199 * 1. Not simplex devices are handled properly. 2200 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2201 * called with rcu_read_lock() 2202 */ 2203 2204 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2205 u8 tos, struct net_device *dev, 2206 struct fib_result *res) 2207 { 2208 struct in_device *in_dev = __in_dev_get_rcu(dev); 2209 struct flow_keys *flkeys = NULL, _flkeys; 2210 struct net *net = dev_net(dev); 2211 struct ip_tunnel_info *tun_info; 2212 int err = -EINVAL; 2213 unsigned int flags = 0; 2214 u32 itag = 0; 2215 struct rtable *rth; 2216 struct flowi4 fl4; 2217 bool do_cache = true; 2218 2219 /* IP on this device is disabled. */ 2220 2221 if (!in_dev) 2222 goto out; 2223 2224 /* Check for the most weird martians, which can be not detected 2225 * by fib_lookup. 2226 */ 2227 2228 tun_info = skb_tunnel_info(skb); 2229 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2230 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2231 else 2232 fl4.flowi4_tun_key.tun_id = 0; 2233 skb_dst_drop(skb); 2234 2235 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2236 goto martian_source; 2237 2238 res->fi = NULL; 2239 res->table = NULL; 2240 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2241 goto brd_input; 2242 2243 /* Accept zero addresses only to limited broadcast; 2244 * I even do not know to fix it or not. Waiting for complains :-) 2245 */ 2246 if (ipv4_is_zeronet(saddr)) 2247 goto martian_source; 2248 2249 if (ipv4_is_zeronet(daddr)) 2250 goto martian_destination; 2251 2252 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2253 * and call it once if daddr or/and saddr are loopback addresses 2254 */ 2255 if (ipv4_is_loopback(daddr)) { 2256 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2257 goto martian_destination; 2258 } else if (ipv4_is_loopback(saddr)) { 2259 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2260 goto martian_source; 2261 } 2262 2263 /* 2264 * Now we are ready to route packet. 2265 */ 2266 fl4.flowi4_l3mdev = 0; 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_RO(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 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2337 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2338 2339 do_cache &= res->fi && !itag; 2340 if (do_cache) { 2341 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2342 2343 rth = rcu_dereference(nhc->nhc_rth_input); 2344 if (rt_cache_valid(rth)) { 2345 skb_dst_set_noref(skb, &rth->dst); 2346 err = 0; 2347 goto out; 2348 } 2349 } 2350 2351 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2352 flags | RTCF_LOCAL, res->type, false); 2353 if (!rth) 2354 goto e_nobufs; 2355 2356 rth->dst.output= ip_rt_bug; 2357 #ifdef CONFIG_IP_ROUTE_CLASSID 2358 rth->dst.tclassid = itag; 2359 #endif 2360 rth->rt_is_input = 1; 2361 2362 RT_CACHE_STAT_INC(in_slow_tot); 2363 if (res->type == RTN_UNREACHABLE) { 2364 rth->dst.input= ip_error; 2365 rth->dst.error= -err; 2366 rth->rt_flags &= ~RTCF_LOCAL; 2367 } 2368 2369 if (do_cache) { 2370 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2371 2372 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2373 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2374 WARN_ON(rth->dst.input == lwtunnel_input); 2375 rth->dst.lwtstate->orig_input = rth->dst.input; 2376 rth->dst.input = lwtunnel_input; 2377 } 2378 2379 if (unlikely(!rt_cache_route(nhc, rth))) 2380 rt_add_uncached_list(rth); 2381 } 2382 skb_dst_set(skb, &rth->dst); 2383 err = 0; 2384 goto out; 2385 2386 no_route: 2387 RT_CACHE_STAT_INC(in_no_route); 2388 res->type = RTN_UNREACHABLE; 2389 res->fi = NULL; 2390 res->table = NULL; 2391 goto local_input; 2392 2393 /* 2394 * Do not cache martian addresses: they should be logged (RFC1812) 2395 */ 2396 martian_destination: 2397 RT_CACHE_STAT_INC(in_martian_dst); 2398 #ifdef CONFIG_IP_ROUTE_VERBOSE 2399 if (IN_DEV_LOG_MARTIANS(in_dev)) 2400 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2401 &daddr, &saddr, dev->name); 2402 #endif 2403 2404 e_inval: 2405 err = -EINVAL; 2406 goto out; 2407 2408 e_nobufs: 2409 err = -ENOBUFS; 2410 goto out; 2411 2412 martian_source: 2413 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2414 goto out; 2415 } 2416 2417 /* called with rcu_read_lock held */ 2418 static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2419 u8 tos, struct net_device *dev, struct fib_result *res) 2420 { 2421 /* Multicast recognition logic is moved from route cache to here. 2422 * The problem was that too many Ethernet cards have broken/missing 2423 * hardware multicast filters :-( As result the host on multicasting 2424 * network acquires a lot of useless route cache entries, sort of 2425 * SDR messages from all the world. Now we try to get rid of them. 2426 * Really, provided software IP multicast filter is organized 2427 * reasonably (at least, hashed), it does not result in a slowdown 2428 * comparing with route cache reject entries. 2429 * Note, that multicast routers are not affected, because 2430 * route cache entry is created eventually. 2431 */ 2432 if (ipv4_is_multicast(daddr)) { 2433 struct in_device *in_dev = __in_dev_get_rcu(dev); 2434 int our = 0; 2435 int err = -EINVAL; 2436 2437 if (!in_dev) 2438 return err; 2439 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2440 ip_hdr(skb)->protocol); 2441 2442 /* check l3 master if no match yet */ 2443 if (!our && netif_is_l3_slave(dev)) { 2444 struct in_device *l3_in_dev; 2445 2446 l3_in_dev = __in_dev_get_rcu(skb->dev); 2447 if (l3_in_dev) 2448 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2449 ip_hdr(skb)->protocol); 2450 } 2451 2452 if (our 2453 #ifdef CONFIG_IP_MROUTE 2454 || 2455 (!ipv4_is_local_multicast(daddr) && 2456 IN_DEV_MFORWARD(in_dev)) 2457 #endif 2458 ) { 2459 err = ip_route_input_mc(skb, daddr, saddr, 2460 tos, dev, our); 2461 } 2462 return err; 2463 } 2464 2465 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2466 } 2467 2468 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2469 u8 tos, struct net_device *dev) 2470 { 2471 struct fib_result res; 2472 int err; 2473 2474 tos &= IPTOS_RT_MASK; 2475 rcu_read_lock(); 2476 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2477 rcu_read_unlock(); 2478 2479 return err; 2480 } 2481 EXPORT_SYMBOL(ip_route_input_noref); 2482 2483 /* called with rcu_read_lock() */ 2484 static struct rtable *__mkroute_output(const struct fib_result *res, 2485 const struct flowi4 *fl4, int orig_oif, 2486 struct net_device *dev_out, 2487 unsigned int flags) 2488 { 2489 struct fib_info *fi = res->fi; 2490 struct fib_nh_exception *fnhe; 2491 struct in_device *in_dev; 2492 u16 type = res->type; 2493 struct rtable *rth; 2494 bool do_cache; 2495 2496 in_dev = __in_dev_get_rcu(dev_out); 2497 if (!in_dev) 2498 return ERR_PTR(-EINVAL); 2499 2500 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2501 if (ipv4_is_loopback(fl4->saddr) && 2502 !(dev_out->flags & IFF_LOOPBACK) && 2503 !netif_is_l3_master(dev_out)) 2504 return ERR_PTR(-EINVAL); 2505 2506 if (ipv4_is_lbcast(fl4->daddr)) 2507 type = RTN_BROADCAST; 2508 else if (ipv4_is_multicast(fl4->daddr)) 2509 type = RTN_MULTICAST; 2510 else if (ipv4_is_zeronet(fl4->daddr)) 2511 return ERR_PTR(-EINVAL); 2512 2513 if (dev_out->flags & IFF_LOOPBACK) 2514 flags |= RTCF_LOCAL; 2515 2516 do_cache = true; 2517 if (type == RTN_BROADCAST) { 2518 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2519 fi = NULL; 2520 } else if (type == RTN_MULTICAST) { 2521 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2522 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2523 fl4->flowi4_proto)) 2524 flags &= ~RTCF_LOCAL; 2525 else 2526 do_cache = false; 2527 /* If multicast route do not exist use 2528 * default one, but do not gateway in this case. 2529 * Yes, it is hack. 2530 */ 2531 if (fi && res->prefixlen < 4) 2532 fi = NULL; 2533 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2534 (orig_oif != dev_out->ifindex)) { 2535 /* For local routes that require a particular output interface 2536 * we do not want to cache the result. Caching the result 2537 * causes incorrect behaviour when there are multiple source 2538 * addresses on the interface, the end result being that if the 2539 * intended recipient is waiting on that interface for the 2540 * packet he won't receive it because it will be delivered on 2541 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2542 * be set to the loopback interface as well. 2543 */ 2544 do_cache = false; 2545 } 2546 2547 fnhe = NULL; 2548 do_cache &= fi != NULL; 2549 if (fi) { 2550 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2551 struct rtable __rcu **prth; 2552 2553 fnhe = find_exception(nhc, fl4->daddr); 2554 if (!do_cache) 2555 goto add; 2556 if (fnhe) { 2557 prth = &fnhe->fnhe_rth_output; 2558 } else { 2559 if (unlikely(fl4->flowi4_flags & 2560 FLOWI_FLAG_KNOWN_NH && 2561 !(nhc->nhc_gw_family && 2562 nhc->nhc_scope == RT_SCOPE_LINK))) { 2563 do_cache = false; 2564 goto add; 2565 } 2566 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2567 } 2568 rth = rcu_dereference(*prth); 2569 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2570 return rth; 2571 } 2572 2573 add: 2574 rth = rt_dst_alloc(dev_out, flags, type, 2575 IN_DEV_ORCONF(in_dev, NOXFRM)); 2576 if (!rth) 2577 return ERR_PTR(-ENOBUFS); 2578 2579 rth->rt_iif = orig_oif; 2580 2581 RT_CACHE_STAT_INC(out_slow_tot); 2582 2583 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2584 if (flags & RTCF_LOCAL && 2585 !(dev_out->flags & IFF_LOOPBACK)) { 2586 rth->dst.output = ip_mc_output; 2587 RT_CACHE_STAT_INC(out_slow_mc); 2588 } 2589 #ifdef CONFIG_IP_MROUTE 2590 if (type == RTN_MULTICAST) { 2591 if (IN_DEV_MFORWARD(in_dev) && 2592 !ipv4_is_local_multicast(fl4->daddr)) { 2593 rth->dst.input = ip_mr_input; 2594 rth->dst.output = ip_mc_output; 2595 } 2596 } 2597 #endif 2598 } 2599 2600 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2601 lwtunnel_set_redirect(&rth->dst); 2602 2603 return rth; 2604 } 2605 2606 /* 2607 * Major route resolver routine. 2608 */ 2609 2610 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2611 const struct sk_buff *skb) 2612 { 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 &= IPTOS_RT_MASK; 2623 2624 rcu_read_lock(); 2625 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2626 rcu_read_unlock(); 2627 2628 return rth; 2629 } 2630 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2631 2632 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2633 struct fib_result *res, 2634 const struct sk_buff *skb) 2635 { 2636 struct net_device *dev_out = NULL; 2637 int orig_oif = fl4->flowi4_oif; 2638 unsigned int flags = 0; 2639 struct rtable *rth; 2640 int err; 2641 2642 if (fl4->saddr) { 2643 if (ipv4_is_multicast(fl4->saddr) || 2644 ipv4_is_lbcast(fl4->saddr) || 2645 ipv4_is_zeronet(fl4->saddr)) { 2646 rth = ERR_PTR(-EINVAL); 2647 goto out; 2648 } 2649 2650 rth = ERR_PTR(-ENETUNREACH); 2651 2652 /* I removed check for oif == dev_out->oif here. 2653 * It was wrong for two reasons: 2654 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2655 * is assigned to multiple interfaces. 2656 * 2. Moreover, we are allowed to send packets with saddr 2657 * of another iface. --ANK 2658 */ 2659 2660 if (fl4->flowi4_oif == 0 && 2661 (ipv4_is_multicast(fl4->daddr) || 2662 ipv4_is_lbcast(fl4->daddr))) { 2663 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2664 dev_out = __ip_dev_find(net, fl4->saddr, false); 2665 if (!dev_out) 2666 goto out; 2667 2668 /* Special hack: user can direct multicasts 2669 * and limited broadcast via necessary interface 2670 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2671 * This hack is not just for fun, it allows 2672 * vic,vat and friends to work. 2673 * They bind socket to loopback, set ttl to zero 2674 * and expect that it will work. 2675 * From the viewpoint of routing cache they are broken, 2676 * because we are not allowed to build multicast path 2677 * with loopback source addr (look, routing cache 2678 * cannot know, that ttl is zero, so that packet 2679 * will not leave this host and route is valid). 2680 * Luckily, this hack is good workaround. 2681 */ 2682 2683 fl4->flowi4_oif = dev_out->ifindex; 2684 goto make_route; 2685 } 2686 2687 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2688 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2689 if (!__ip_dev_find(net, fl4->saddr, false)) 2690 goto out; 2691 } 2692 } 2693 2694 2695 if (fl4->flowi4_oif) { 2696 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2697 rth = ERR_PTR(-ENODEV); 2698 if (!dev_out) 2699 goto out; 2700 2701 /* RACE: Check return value of inet_select_addr instead. */ 2702 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2703 rth = ERR_PTR(-ENETUNREACH); 2704 goto out; 2705 } 2706 if (ipv4_is_local_multicast(fl4->daddr) || 2707 ipv4_is_lbcast(fl4->daddr) || 2708 fl4->flowi4_proto == IPPROTO_IGMP) { 2709 if (!fl4->saddr) 2710 fl4->saddr = inet_select_addr(dev_out, 0, 2711 RT_SCOPE_LINK); 2712 goto make_route; 2713 } 2714 if (!fl4->saddr) { 2715 if (ipv4_is_multicast(fl4->daddr)) 2716 fl4->saddr = inet_select_addr(dev_out, 0, 2717 fl4->flowi4_scope); 2718 else if (!fl4->daddr) 2719 fl4->saddr = inet_select_addr(dev_out, 0, 2720 RT_SCOPE_HOST); 2721 } 2722 } 2723 2724 if (!fl4->daddr) { 2725 fl4->daddr = fl4->saddr; 2726 if (!fl4->daddr) 2727 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2728 dev_out = net->loopback_dev; 2729 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2730 res->type = RTN_LOCAL; 2731 flags |= RTCF_LOCAL; 2732 goto make_route; 2733 } 2734 2735 err = fib_lookup(net, fl4, res, 0); 2736 if (err) { 2737 res->fi = NULL; 2738 res->table = NULL; 2739 if (fl4->flowi4_oif && 2740 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2741 /* Apparently, routing tables are wrong. Assume, 2742 * that the destination is on link. 2743 * 2744 * WHY? DW. 2745 * Because we are allowed to send to iface 2746 * even if it has NO routes and NO assigned 2747 * addresses. When oif is specified, routing 2748 * tables are looked up with only one purpose: 2749 * to catch if destination is gatewayed, rather than 2750 * direct. Moreover, if MSG_DONTROUTE is set, 2751 * we send packet, ignoring both routing tables 2752 * and ifaddr state. --ANK 2753 * 2754 * 2755 * We could make it even if oif is unknown, 2756 * likely IPv6, but we do not. 2757 */ 2758 2759 if (fl4->saddr == 0) 2760 fl4->saddr = inet_select_addr(dev_out, 0, 2761 RT_SCOPE_LINK); 2762 res->type = RTN_UNICAST; 2763 goto make_route; 2764 } 2765 rth = ERR_PTR(err); 2766 goto out; 2767 } 2768 2769 if (res->type == RTN_LOCAL) { 2770 if (!fl4->saddr) { 2771 if (res->fi->fib_prefsrc) 2772 fl4->saddr = res->fi->fib_prefsrc; 2773 else 2774 fl4->saddr = fl4->daddr; 2775 } 2776 2777 /* L3 master device is the loopback for that domain */ 2778 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2779 net->loopback_dev; 2780 2781 /* make sure orig_oif points to fib result device even 2782 * though packet rx/tx happens over loopback or l3mdev 2783 */ 2784 orig_oif = FIB_RES_OIF(*res); 2785 2786 fl4->flowi4_oif = dev_out->ifindex; 2787 flags |= RTCF_LOCAL; 2788 goto make_route; 2789 } 2790 2791 fib_select_path(net, res, fl4, skb); 2792 2793 dev_out = FIB_RES_DEV(*res); 2794 2795 make_route: 2796 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2797 2798 out: 2799 return rth; 2800 } 2801 2802 static struct dst_ops ipv4_dst_blackhole_ops = { 2803 .family = AF_INET, 2804 .default_advmss = ipv4_default_advmss, 2805 .neigh_lookup = ipv4_neigh_lookup, 2806 .check = dst_blackhole_check, 2807 .cow_metrics = dst_blackhole_cow_metrics, 2808 .update_pmtu = dst_blackhole_update_pmtu, 2809 .redirect = dst_blackhole_redirect, 2810 .mtu = dst_blackhole_mtu, 2811 }; 2812 2813 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2814 { 2815 struct rtable *ort = dst_rtable(dst_orig); 2816 struct rtable *rt; 2817 2818 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2819 if (rt) { 2820 struct dst_entry *new = &rt->dst; 2821 2822 new->__use = 1; 2823 new->input = dst_discard; 2824 new->output = dst_discard_out; 2825 2826 new->dev = net->loopback_dev; 2827 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2828 2829 rt->rt_is_input = ort->rt_is_input; 2830 rt->rt_iif = ort->rt_iif; 2831 rt->rt_pmtu = ort->rt_pmtu; 2832 rt->rt_mtu_locked = ort->rt_mtu_locked; 2833 2834 rt->rt_genid = rt_genid_ipv4(net); 2835 rt->rt_flags = ort->rt_flags; 2836 rt->rt_type = ort->rt_type; 2837 rt->rt_uses_gateway = ort->rt_uses_gateway; 2838 rt->rt_gw_family = ort->rt_gw_family; 2839 if (rt->rt_gw_family == AF_INET) 2840 rt->rt_gw4 = ort->rt_gw4; 2841 else if (rt->rt_gw_family == AF_INET6) 2842 rt->rt_gw6 = ort->rt_gw6; 2843 } 2844 2845 dst_release(dst_orig); 2846 2847 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2848 } 2849 2850 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2851 const struct sock *sk) 2852 { 2853 struct rtable *rt = __ip_route_output_key(net, flp4); 2854 2855 if (IS_ERR(rt)) 2856 return rt; 2857 2858 if (flp4->flowi4_proto) { 2859 flp4->flowi4_oif = rt->dst.dev->ifindex; 2860 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2861 flowi4_to_flowi(flp4), 2862 sk, 0)); 2863 } 2864 2865 return rt; 2866 } 2867 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2868 2869 /* called with rcu_read_lock held */ 2870 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2871 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2872 struct sk_buff *skb, u32 portid, u32 seq, 2873 unsigned int flags) 2874 { 2875 struct rtmsg *r; 2876 struct nlmsghdr *nlh; 2877 unsigned long expires = 0; 2878 u32 error; 2879 u32 metrics[RTAX_MAX]; 2880 2881 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2882 if (!nlh) 2883 return -EMSGSIZE; 2884 2885 r = nlmsg_data(nlh); 2886 r->rtm_family = AF_INET; 2887 r->rtm_dst_len = 32; 2888 r->rtm_src_len = 0; 2889 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2890 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2891 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2892 goto nla_put_failure; 2893 r->rtm_type = rt->rt_type; 2894 r->rtm_scope = RT_SCOPE_UNIVERSE; 2895 r->rtm_protocol = RTPROT_UNSPEC; 2896 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2897 if (rt->rt_flags & RTCF_NOTIFY) 2898 r->rtm_flags |= RTM_F_NOTIFY; 2899 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2900 r->rtm_flags |= RTCF_DOREDIRECT; 2901 2902 if (nla_put_in_addr(skb, RTA_DST, dst)) 2903 goto nla_put_failure; 2904 if (src) { 2905 r->rtm_src_len = 32; 2906 if (nla_put_in_addr(skb, RTA_SRC, src)) 2907 goto nla_put_failure; 2908 } 2909 if (rt->dst.dev && 2910 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2911 goto nla_put_failure; 2912 if (rt->dst.lwtstate && 2913 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2914 goto nla_put_failure; 2915 #ifdef CONFIG_IP_ROUTE_CLASSID 2916 if (rt->dst.tclassid && 2917 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2918 goto nla_put_failure; 2919 #endif 2920 if (fl4 && !rt_is_input_route(rt) && 2921 fl4->saddr != src) { 2922 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2923 goto nla_put_failure; 2924 } 2925 if (rt->rt_uses_gateway) { 2926 if (rt->rt_gw_family == AF_INET && 2927 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2928 goto nla_put_failure; 2929 } else if (rt->rt_gw_family == AF_INET6) { 2930 int alen = sizeof(struct in6_addr); 2931 struct nlattr *nla; 2932 struct rtvia *via; 2933 2934 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2935 if (!nla) 2936 goto nla_put_failure; 2937 2938 via = nla_data(nla); 2939 via->rtvia_family = AF_INET6; 2940 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2941 } 2942 } 2943 2944 expires = rt->dst.expires; 2945 if (expires) { 2946 unsigned long now = jiffies; 2947 2948 if (time_before(now, expires)) 2949 expires -= now; 2950 else 2951 expires = 0; 2952 } 2953 2954 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2955 if (rt->rt_pmtu && expires) 2956 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2957 if (rt->rt_mtu_locked && expires) 2958 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2959 if (rtnetlink_put_metrics(skb, metrics) < 0) 2960 goto nla_put_failure; 2961 2962 if (fl4) { 2963 if (fl4->flowi4_mark && 2964 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2965 goto nla_put_failure; 2966 2967 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2968 nla_put_u32(skb, RTA_UID, 2969 from_kuid_munged(current_user_ns(), 2970 fl4->flowi4_uid))) 2971 goto nla_put_failure; 2972 2973 if (rt_is_input_route(rt)) { 2974 #ifdef CONFIG_IP_MROUTE 2975 if (ipv4_is_multicast(dst) && 2976 !ipv4_is_local_multicast(dst) && 2977 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 2978 int err = ipmr_get_route(net, skb, 2979 fl4->saddr, fl4->daddr, 2980 r, portid); 2981 2982 if (err <= 0) { 2983 if (err == 0) 2984 return 0; 2985 goto nla_put_failure; 2986 } 2987 } else 2988 #endif 2989 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2990 goto nla_put_failure; 2991 } 2992 } 2993 2994 error = rt->dst.error; 2995 2996 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2997 goto nla_put_failure; 2998 2999 nlmsg_end(skb, nlh); 3000 return 0; 3001 3002 nla_put_failure: 3003 nlmsg_cancel(skb, nlh); 3004 return -EMSGSIZE; 3005 } 3006 3007 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3008 struct netlink_callback *cb, u32 table_id, 3009 struct fnhe_hash_bucket *bucket, int genid, 3010 int *fa_index, int fa_start, unsigned int flags) 3011 { 3012 int i; 3013 3014 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3015 struct fib_nh_exception *fnhe; 3016 3017 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3018 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3019 struct rtable *rt; 3020 int err; 3021 3022 if (*fa_index < fa_start) 3023 goto next; 3024 3025 if (fnhe->fnhe_genid != genid) 3026 goto next; 3027 3028 if (fnhe->fnhe_expires && 3029 time_after(jiffies, fnhe->fnhe_expires)) 3030 goto next; 3031 3032 rt = rcu_dereference(fnhe->fnhe_rth_input); 3033 if (!rt) 3034 rt = rcu_dereference(fnhe->fnhe_rth_output); 3035 if (!rt) 3036 goto next; 3037 3038 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3039 table_id, NULL, skb, 3040 NETLINK_CB(cb->skb).portid, 3041 cb->nlh->nlmsg_seq, flags); 3042 if (err) 3043 return err; 3044 next: 3045 (*fa_index)++; 3046 } 3047 } 3048 3049 return 0; 3050 } 3051 3052 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3053 u32 table_id, struct fib_info *fi, 3054 int *fa_index, int fa_start, unsigned int flags) 3055 { 3056 struct net *net = sock_net(cb->skb->sk); 3057 int nhsel, genid = fnhe_genid(net); 3058 3059 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3060 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3061 struct fnhe_hash_bucket *bucket; 3062 int err; 3063 3064 if (nhc->nhc_flags & RTNH_F_DEAD) 3065 continue; 3066 3067 rcu_read_lock(); 3068 bucket = rcu_dereference(nhc->nhc_exceptions); 3069 err = 0; 3070 if (bucket) 3071 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3072 genid, fa_index, fa_start, 3073 flags); 3074 rcu_read_unlock(); 3075 if (err) 3076 return err; 3077 } 3078 3079 return 0; 3080 } 3081 3082 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3083 u8 ip_proto, __be16 sport, 3084 __be16 dport) 3085 { 3086 struct sk_buff *skb; 3087 struct iphdr *iph; 3088 3089 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3090 if (!skb) 3091 return NULL; 3092 3093 /* Reserve room for dummy headers, this skb can pass 3094 * through good chunk of routing engine. 3095 */ 3096 skb_reset_mac_header(skb); 3097 skb_reset_network_header(skb); 3098 skb->protocol = htons(ETH_P_IP); 3099 iph = skb_put(skb, sizeof(struct iphdr)); 3100 iph->protocol = ip_proto; 3101 iph->saddr = src; 3102 iph->daddr = dst; 3103 iph->version = 0x4; 3104 iph->frag_off = 0; 3105 iph->ihl = 0x5; 3106 skb_set_transport_header(skb, skb->len); 3107 3108 switch (iph->protocol) { 3109 case IPPROTO_UDP: { 3110 struct udphdr *udph; 3111 3112 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3113 udph->source = sport; 3114 udph->dest = dport; 3115 udph->len = htons(sizeof(struct udphdr)); 3116 udph->check = 0; 3117 break; 3118 } 3119 case IPPROTO_TCP: { 3120 struct tcphdr *tcph; 3121 3122 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3123 tcph->source = sport; 3124 tcph->dest = dport; 3125 tcph->doff = sizeof(struct tcphdr) / 4; 3126 tcph->rst = 1; 3127 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3128 src, dst, 0); 3129 break; 3130 } 3131 case IPPROTO_ICMP: { 3132 struct icmphdr *icmph; 3133 3134 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3135 icmph->type = ICMP_ECHO; 3136 icmph->code = 0; 3137 } 3138 } 3139 3140 return skb; 3141 } 3142 3143 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3144 const struct nlmsghdr *nlh, 3145 struct nlattr **tb, 3146 struct netlink_ext_ack *extack) 3147 { 3148 struct rtmsg *rtm; 3149 int i, err; 3150 3151 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3152 NL_SET_ERR_MSG(extack, 3153 "ipv4: Invalid header for route get request"); 3154 return -EINVAL; 3155 } 3156 3157 if (!netlink_strict_get_check(skb)) 3158 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3159 rtm_ipv4_policy, extack); 3160 3161 rtm = nlmsg_data(nlh); 3162 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3163 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3164 rtm->rtm_table || rtm->rtm_protocol || 3165 rtm->rtm_scope || rtm->rtm_type) { 3166 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3167 return -EINVAL; 3168 } 3169 3170 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3171 RTM_F_LOOKUP_TABLE | 3172 RTM_F_FIB_MATCH)) { 3173 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3174 return -EINVAL; 3175 } 3176 3177 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3178 rtm_ipv4_policy, extack); 3179 if (err) 3180 return err; 3181 3182 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3183 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3184 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3185 return -EINVAL; 3186 } 3187 3188 for (i = 0; i <= RTA_MAX; i++) { 3189 if (!tb[i]) 3190 continue; 3191 3192 switch (i) { 3193 case RTA_IIF: 3194 case RTA_OIF: 3195 case RTA_SRC: 3196 case RTA_DST: 3197 case RTA_IP_PROTO: 3198 case RTA_SPORT: 3199 case RTA_DPORT: 3200 case RTA_MARK: 3201 case RTA_UID: 3202 break; 3203 default: 3204 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3205 return -EINVAL; 3206 } 3207 } 3208 3209 return 0; 3210 } 3211 3212 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3213 struct netlink_ext_ack *extack) 3214 { 3215 struct net *net = sock_net(in_skb->sk); 3216 struct nlattr *tb[RTA_MAX+1]; 3217 u32 table_id = RT_TABLE_MAIN; 3218 __be16 sport = 0, dport = 0; 3219 struct fib_result res = {}; 3220 u8 ip_proto = IPPROTO_UDP; 3221 struct rtable *rt = NULL; 3222 struct sk_buff *skb; 3223 struct rtmsg *rtm; 3224 struct flowi4 fl4 = {}; 3225 __be32 dst = 0; 3226 __be32 src = 0; 3227 kuid_t uid; 3228 u32 iif; 3229 int err; 3230 int mark; 3231 3232 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3233 if (err < 0) 3234 return err; 3235 3236 rtm = nlmsg_data(nlh); 3237 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3238 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3239 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3240 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3241 if (tb[RTA_UID]) 3242 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3243 else 3244 uid = (iif ? INVALID_UID : current_uid()); 3245 3246 if (tb[RTA_IP_PROTO]) { 3247 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3248 &ip_proto, AF_INET, extack); 3249 if (err) 3250 return err; 3251 } 3252 3253 if (tb[RTA_SPORT]) 3254 sport = nla_get_be16(tb[RTA_SPORT]); 3255 3256 if (tb[RTA_DPORT]) 3257 dport = nla_get_be16(tb[RTA_DPORT]); 3258 3259 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3260 if (!skb) 3261 return -ENOBUFS; 3262 3263 fl4.daddr = dst; 3264 fl4.saddr = src; 3265 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3266 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3267 fl4.flowi4_mark = mark; 3268 fl4.flowi4_uid = uid; 3269 if (sport) 3270 fl4.fl4_sport = sport; 3271 if (dport) 3272 fl4.fl4_dport = dport; 3273 fl4.flowi4_proto = ip_proto; 3274 3275 rcu_read_lock(); 3276 3277 if (iif) { 3278 struct net_device *dev; 3279 3280 dev = dev_get_by_index_rcu(net, iif); 3281 if (!dev) { 3282 err = -ENODEV; 3283 goto errout_rcu; 3284 } 3285 3286 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3287 skb->dev = dev; 3288 skb->mark = mark; 3289 err = ip_route_input_rcu(skb, dst, src, 3290 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3291 &res); 3292 3293 rt = skb_rtable(skb); 3294 if (err == 0 && rt->dst.error) 3295 err = -rt->dst.error; 3296 } else { 3297 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3298 skb->dev = net->loopback_dev; 3299 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3300 err = 0; 3301 if (IS_ERR(rt)) 3302 err = PTR_ERR(rt); 3303 else 3304 skb_dst_set(skb, &rt->dst); 3305 } 3306 3307 if (err) 3308 goto errout_rcu; 3309 3310 if (rtm->rtm_flags & RTM_F_NOTIFY) 3311 rt->rt_flags |= RTCF_NOTIFY; 3312 3313 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3314 table_id = res.table ? res.table->tb_id : 0; 3315 3316 /* reset skb for netlink reply msg */ 3317 skb_trim(skb, 0); 3318 skb_reset_network_header(skb); 3319 skb_reset_transport_header(skb); 3320 skb_reset_mac_header(skb); 3321 3322 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3323 struct fib_rt_info fri; 3324 3325 if (!res.fi) { 3326 err = fib_props[res.type].error; 3327 if (!err) 3328 err = -EHOSTUNREACH; 3329 goto errout_rcu; 3330 } 3331 fri.fi = res.fi; 3332 fri.tb_id = table_id; 3333 fri.dst = res.prefix; 3334 fri.dst_len = res.prefixlen; 3335 fri.dscp = inet_dsfield_to_dscp(fl4.flowi4_tos); 3336 fri.type = rt->rt_type; 3337 fri.offload = 0; 3338 fri.trap = 0; 3339 fri.offload_failed = 0; 3340 if (res.fa_head) { 3341 struct fib_alias *fa; 3342 3343 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3344 u8 slen = 32 - fri.dst_len; 3345 3346 if (fa->fa_slen == slen && 3347 fa->tb_id == fri.tb_id && 3348 fa->fa_dscp == fri.dscp && 3349 fa->fa_info == res.fi && 3350 fa->fa_type == fri.type) { 3351 fri.offload = READ_ONCE(fa->offload); 3352 fri.trap = READ_ONCE(fa->trap); 3353 fri.offload_failed = 3354 READ_ONCE(fa->offload_failed); 3355 break; 3356 } 3357 } 3358 } 3359 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3360 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3361 } else { 3362 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3363 NETLINK_CB(in_skb).portid, 3364 nlh->nlmsg_seq, 0); 3365 } 3366 if (err < 0) 3367 goto errout_rcu; 3368 3369 rcu_read_unlock(); 3370 3371 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3372 3373 errout_free: 3374 return err; 3375 errout_rcu: 3376 rcu_read_unlock(); 3377 kfree_skb(skb); 3378 goto errout_free; 3379 } 3380 3381 void ip_rt_multicast_event(struct in_device *in_dev) 3382 { 3383 rt_cache_flush(dev_net(in_dev->dev)); 3384 } 3385 3386 #ifdef CONFIG_SYSCTL 3387 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3388 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3389 static int ip_rt_gc_elasticity __read_mostly = 8; 3390 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3391 3392 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3393 void *buffer, size_t *lenp, loff_t *ppos) 3394 { 3395 struct net *net = (struct net *)__ctl->extra1; 3396 3397 if (write) { 3398 rt_cache_flush(net); 3399 fnhe_genid_bump(net); 3400 return 0; 3401 } 3402 3403 return -EINVAL; 3404 } 3405 3406 static struct ctl_table ipv4_route_table[] = { 3407 { 3408 .procname = "gc_thresh", 3409 .data = &ipv4_dst_ops.gc_thresh, 3410 .maxlen = sizeof(int), 3411 .mode = 0644, 3412 .proc_handler = proc_dointvec, 3413 }, 3414 { 3415 .procname = "max_size", 3416 .data = &ip_rt_max_size, 3417 .maxlen = sizeof(int), 3418 .mode = 0644, 3419 .proc_handler = proc_dointvec, 3420 }, 3421 { 3422 /* Deprecated. Use gc_min_interval_ms */ 3423 3424 .procname = "gc_min_interval", 3425 .data = &ip_rt_gc_min_interval, 3426 .maxlen = sizeof(int), 3427 .mode = 0644, 3428 .proc_handler = proc_dointvec_jiffies, 3429 }, 3430 { 3431 .procname = "gc_min_interval_ms", 3432 .data = &ip_rt_gc_min_interval, 3433 .maxlen = sizeof(int), 3434 .mode = 0644, 3435 .proc_handler = proc_dointvec_ms_jiffies, 3436 }, 3437 { 3438 .procname = "gc_timeout", 3439 .data = &ip_rt_gc_timeout, 3440 .maxlen = sizeof(int), 3441 .mode = 0644, 3442 .proc_handler = proc_dointvec_jiffies, 3443 }, 3444 { 3445 .procname = "gc_interval", 3446 .data = &ip_rt_gc_interval, 3447 .maxlen = sizeof(int), 3448 .mode = 0644, 3449 .proc_handler = proc_dointvec_jiffies, 3450 }, 3451 { 3452 .procname = "redirect_load", 3453 .data = &ip_rt_redirect_load, 3454 .maxlen = sizeof(int), 3455 .mode = 0644, 3456 .proc_handler = proc_dointvec, 3457 }, 3458 { 3459 .procname = "redirect_number", 3460 .data = &ip_rt_redirect_number, 3461 .maxlen = sizeof(int), 3462 .mode = 0644, 3463 .proc_handler = proc_dointvec, 3464 }, 3465 { 3466 .procname = "redirect_silence", 3467 .data = &ip_rt_redirect_silence, 3468 .maxlen = sizeof(int), 3469 .mode = 0644, 3470 .proc_handler = proc_dointvec, 3471 }, 3472 { 3473 .procname = "error_cost", 3474 .data = &ip_rt_error_cost, 3475 .maxlen = sizeof(int), 3476 .mode = 0644, 3477 .proc_handler = proc_dointvec, 3478 }, 3479 { 3480 .procname = "error_burst", 3481 .data = &ip_rt_error_burst, 3482 .maxlen = sizeof(int), 3483 .mode = 0644, 3484 .proc_handler = proc_dointvec, 3485 }, 3486 { 3487 .procname = "gc_elasticity", 3488 .data = &ip_rt_gc_elasticity, 3489 .maxlen = sizeof(int), 3490 .mode = 0644, 3491 .proc_handler = proc_dointvec, 3492 }, 3493 }; 3494 3495 static const char ipv4_route_flush_procname[] = "flush"; 3496 3497 static struct ctl_table ipv4_route_netns_table[] = { 3498 { 3499 .procname = ipv4_route_flush_procname, 3500 .maxlen = sizeof(int), 3501 .mode = 0200, 3502 .proc_handler = ipv4_sysctl_rtcache_flush, 3503 }, 3504 { 3505 .procname = "min_pmtu", 3506 .data = &init_net.ipv4.ip_rt_min_pmtu, 3507 .maxlen = sizeof(int), 3508 .mode = 0644, 3509 .proc_handler = proc_dointvec_minmax, 3510 .extra1 = &ip_min_valid_pmtu, 3511 }, 3512 { 3513 .procname = "mtu_expires", 3514 .data = &init_net.ipv4.ip_rt_mtu_expires, 3515 .maxlen = sizeof(int), 3516 .mode = 0644, 3517 .proc_handler = proc_dointvec_jiffies, 3518 }, 3519 { 3520 .procname = "min_adv_mss", 3521 .data = &init_net.ipv4.ip_rt_min_advmss, 3522 .maxlen = sizeof(int), 3523 .mode = 0644, 3524 .proc_handler = proc_dointvec, 3525 }, 3526 }; 3527 3528 static __net_init int sysctl_route_net_init(struct net *net) 3529 { 3530 struct ctl_table *tbl; 3531 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3532 3533 tbl = ipv4_route_netns_table; 3534 if (!net_eq(net, &init_net)) { 3535 int i; 3536 3537 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3538 if (!tbl) 3539 goto err_dup; 3540 3541 /* Don't export non-whitelisted sysctls to unprivileged users */ 3542 if (net->user_ns != &init_user_ns) { 3543 if (tbl[0].procname != ipv4_route_flush_procname) 3544 table_size = 0; 3545 } 3546 3547 /* Update the variables to point into the current struct net 3548 * except for the first element flush 3549 */ 3550 for (i = 1; i < table_size; i++) 3551 tbl[i].data += (void *)net - (void *)&init_net; 3552 } 3553 tbl[0].extra1 = net; 3554 3555 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3556 tbl, table_size); 3557 if (!net->ipv4.route_hdr) 3558 goto err_reg; 3559 return 0; 3560 3561 err_reg: 3562 if (tbl != ipv4_route_netns_table) 3563 kfree(tbl); 3564 err_dup: 3565 return -ENOMEM; 3566 } 3567 3568 static __net_exit void sysctl_route_net_exit(struct net *net) 3569 { 3570 const struct ctl_table *tbl; 3571 3572 tbl = net->ipv4.route_hdr->ctl_table_arg; 3573 unregister_net_sysctl_table(net->ipv4.route_hdr); 3574 BUG_ON(tbl == ipv4_route_netns_table); 3575 kfree(tbl); 3576 } 3577 3578 static __net_initdata struct pernet_operations sysctl_route_ops = { 3579 .init = sysctl_route_net_init, 3580 .exit = sysctl_route_net_exit, 3581 }; 3582 #endif 3583 3584 static __net_init int netns_ip_rt_init(struct net *net) 3585 { 3586 /* Set default value for namespaceified sysctls */ 3587 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3588 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3589 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3590 return 0; 3591 } 3592 3593 static struct pernet_operations __net_initdata ip_rt_ops = { 3594 .init = netns_ip_rt_init, 3595 }; 3596 3597 static __net_init int rt_genid_init(struct net *net) 3598 { 3599 atomic_set(&net->ipv4.rt_genid, 0); 3600 atomic_set(&net->fnhe_genid, 0); 3601 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3602 return 0; 3603 } 3604 3605 static __net_initdata struct pernet_operations rt_genid_ops = { 3606 .init = rt_genid_init, 3607 }; 3608 3609 static int __net_init ipv4_inetpeer_init(struct net *net) 3610 { 3611 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3612 3613 if (!bp) 3614 return -ENOMEM; 3615 inet_peer_base_init(bp); 3616 net->ipv4.peers = bp; 3617 return 0; 3618 } 3619 3620 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3621 { 3622 struct inet_peer_base *bp = net->ipv4.peers; 3623 3624 net->ipv4.peers = NULL; 3625 inetpeer_invalidate_tree(bp); 3626 kfree(bp); 3627 } 3628 3629 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3630 .init = ipv4_inetpeer_init, 3631 .exit = ipv4_inetpeer_exit, 3632 }; 3633 3634 #ifdef CONFIG_IP_ROUTE_CLASSID 3635 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3636 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3637 3638 int __init ip_rt_init(void) 3639 { 3640 void *idents_hash; 3641 int cpu; 3642 3643 /* For modern hosts, this will use 2 MB of memory */ 3644 idents_hash = alloc_large_system_hash("IP idents", 3645 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3646 0, 3647 16, /* one bucket per 64 KB */ 3648 HASH_ZERO, 3649 NULL, 3650 &ip_idents_mask, 3651 2048, 3652 256*1024); 3653 3654 ip_idents = idents_hash; 3655 3656 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3657 3658 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3659 3660 for_each_possible_cpu(cpu) { 3661 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3662 3663 INIT_LIST_HEAD(&ul->head); 3664 INIT_LIST_HEAD(&ul->quarantine); 3665 spin_lock_init(&ul->lock); 3666 } 3667 #ifdef CONFIG_IP_ROUTE_CLASSID 3668 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3669 if (!ip_rt_acct) 3670 panic("IP: failed to allocate ip_rt_acct\n"); 3671 #endif 3672 3673 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3674 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3675 3676 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3677 3678 if (dst_entries_init(&ipv4_dst_ops) < 0) 3679 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3680 3681 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3682 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3683 3684 ipv4_dst_ops.gc_thresh = ~0; 3685 ip_rt_max_size = INT_MAX; 3686 3687 devinet_init(); 3688 ip_fib_init(); 3689 3690 if (ip_rt_proc_init()) 3691 pr_err("Unable to create route proc files\n"); 3692 #ifdef CONFIG_XFRM 3693 xfrm_init(); 3694 xfrm4_init(); 3695 #endif 3696 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3697 RTNL_FLAG_DOIT_UNLOCKED); 3698 3699 #ifdef CONFIG_SYSCTL 3700 register_pernet_subsys(&sysctl_route_ops); 3701 #endif 3702 register_pernet_subsys(&ip_rt_ops); 3703 register_pernet_subsys(&rt_genid_ops); 3704 register_pernet_subsys(&ipv4_inetpeer_ops); 3705 return 0; 3706 } 3707 3708 #ifdef CONFIG_SYSCTL 3709 /* 3710 * We really need to sanitize the damn ipv4 init order, then all 3711 * this nonsense will go away. 3712 */ 3713 void __init ip_static_sysctl_init(void) 3714 { 3715 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3716 } 3717 #endif 3718