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