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 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 114 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 115 116 static int ip_rt_max_size; 117 static int ip_rt_redirect_number __read_mostly = 9; 118 static int ip_rt_redirect_load __read_mostly = HZ / 50; 119 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 120 static int ip_rt_error_cost __read_mostly = HZ; 121 static int ip_rt_error_burst __read_mostly = 5 * HZ; 122 static int ip_rt_min_advmss __read_mostly = 256; 123 124 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 125 126 /* 127 * Interface to generic destination cache. 128 */ 129 130 INDIRECT_CALLABLE_SCOPE 131 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 133 INDIRECT_CALLABLE_SCOPE 134 unsigned int ipv4_mtu(const struct dst_entry *dst); 135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 136 static void ipv4_link_failure(struct sk_buff *skb); 137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 138 struct sk_buff *skb, u32 mtu, 139 bool confirm_neigh); 140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 141 struct sk_buff *skb); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 144 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 145 { 146 WARN_ON(1); 147 return NULL; 148 } 149 150 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 151 struct sk_buff *skb, 152 const void *daddr); 153 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 154 155 static struct dst_ops ipv4_dst_ops = { 156 .family = AF_INET, 157 .check = ipv4_dst_check, 158 .default_advmss = ipv4_default_advmss, 159 .mtu = ipv4_mtu, 160 .cow_metrics = ipv4_cow_metrics, 161 .destroy = ipv4_dst_destroy, 162 .negative_advice = ipv4_negative_advice, 163 .link_failure = ipv4_link_failure, 164 .update_pmtu = ip_rt_update_pmtu, 165 .redirect = ip_do_redirect, 166 .local_out = __ip_local_out, 167 .neigh_lookup = ipv4_neigh_lookup, 168 .confirm_neigh = ipv4_confirm_neigh, 169 }; 170 171 #define ECN_OR_COST(class) TC_PRIO_##class 172 173 const __u8 ip_tos2prio[16] = { 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BESTEFFORT, 177 ECN_OR_COST(BESTEFFORT), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_BULK, 181 ECN_OR_COST(BULK), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE, 185 ECN_OR_COST(INTERACTIVE), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK), 188 TC_PRIO_INTERACTIVE_BULK, 189 ECN_OR_COST(INTERACTIVE_BULK) 190 }; 191 EXPORT_SYMBOL(ip_tos2prio); 192 193 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 196 #ifdef CONFIG_PROC_FS 197 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 198 { 199 if (*pos) 200 return NULL; 201 return SEQ_START_TOKEN; 202 } 203 204 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 205 { 206 ++*pos; 207 return NULL; 208 } 209 210 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 211 { 212 } 213 214 static int rt_cache_seq_show(struct seq_file *seq, void *v) 215 { 216 if (v == SEQ_START_TOKEN) 217 seq_printf(seq, "%-127s\n", 218 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 219 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 220 "HHUptod\tSpecDst"); 221 return 0; 222 } 223 224 static const struct seq_operations rt_cache_seq_ops = { 225 .start = rt_cache_seq_start, 226 .next = rt_cache_seq_next, 227 .stop = rt_cache_seq_stop, 228 .show = rt_cache_seq_show, 229 }; 230 231 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 232 { 233 int cpu; 234 235 if (*pos == 0) 236 return SEQ_START_TOKEN; 237 238 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 239 if (!cpu_possible(cpu)) 240 continue; 241 *pos = cpu+1; 242 return &per_cpu(rt_cache_stat, cpu); 243 } 244 return NULL; 245 } 246 247 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 248 { 249 int cpu; 250 251 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 252 if (!cpu_possible(cpu)) 253 continue; 254 *pos = cpu+1; 255 return &per_cpu(rt_cache_stat, cpu); 256 } 257 (*pos)++; 258 return NULL; 259 260 } 261 262 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 263 { 264 265 } 266 267 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 268 { 269 struct rt_cache_stat *st = v; 270 271 if (v == SEQ_START_TOKEN) { 272 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"); 273 return 0; 274 } 275 276 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 277 "%08x %08x %08x %08x %08x %08x " 278 "%08x %08x %08x %08x\n", 279 dst_entries_get_slow(&ipv4_dst_ops), 280 0, /* st->in_hit */ 281 st->in_slow_tot, 282 st->in_slow_mc, 283 st->in_no_route, 284 st->in_brd, 285 st->in_martian_dst, 286 st->in_martian_src, 287 288 0, /* st->out_hit */ 289 st->out_slow_tot, 290 st->out_slow_mc, 291 292 0, /* st->gc_total */ 293 0, /* st->gc_ignored */ 294 0, /* st->gc_goal_miss */ 295 0, /* st->gc_dst_overflow */ 296 0, /* st->in_hlist_search */ 297 0 /* st->out_hlist_search */ 298 ); 299 return 0; 300 } 301 302 static const struct seq_operations rt_cpu_seq_ops = { 303 .start = rt_cpu_seq_start, 304 .next = rt_cpu_seq_next, 305 .stop = rt_cpu_seq_stop, 306 .show = rt_cpu_seq_show, 307 }; 308 309 #ifdef CONFIG_IP_ROUTE_CLASSID 310 static int rt_acct_proc_show(struct seq_file *m, void *v) 311 { 312 struct ip_rt_acct *dst, *src; 313 unsigned int i, j; 314 315 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 316 if (!dst) 317 return -ENOMEM; 318 319 for_each_possible_cpu(i) { 320 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 321 for (j = 0; j < 256; j++) { 322 dst[j].o_bytes += src[j].o_bytes; 323 dst[j].o_packets += src[j].o_packets; 324 dst[j].i_bytes += src[j].i_bytes; 325 dst[j].i_packets += src[j].i_packets; 326 } 327 } 328 329 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 330 kfree(dst); 331 return 0; 332 } 333 #endif 334 335 static int __net_init ip_rt_do_proc_init(struct net *net) 336 { 337 struct proc_dir_entry *pde; 338 339 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 340 &rt_cache_seq_ops); 341 if (!pde) 342 goto err1; 343 344 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 345 &rt_cpu_seq_ops); 346 if (!pde) 347 goto err2; 348 349 #ifdef CONFIG_IP_ROUTE_CLASSID 350 pde = proc_create_single("rt_acct", 0, net->proc_net, 351 rt_acct_proc_show); 352 if (!pde) 353 goto err3; 354 #endif 355 return 0; 356 357 #ifdef CONFIG_IP_ROUTE_CLASSID 358 err3: 359 remove_proc_entry("rt_cache", net->proc_net_stat); 360 #endif 361 err2: 362 remove_proc_entry("rt_cache", net->proc_net); 363 err1: 364 return -ENOMEM; 365 } 366 367 static void __net_exit ip_rt_do_proc_exit(struct net *net) 368 { 369 remove_proc_entry("rt_cache", net->proc_net_stat); 370 remove_proc_entry("rt_cache", net->proc_net); 371 #ifdef CONFIG_IP_ROUTE_CLASSID 372 remove_proc_entry("rt_acct", net->proc_net); 373 #endif 374 } 375 376 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 377 .init = ip_rt_do_proc_init, 378 .exit = ip_rt_do_proc_exit, 379 }; 380 381 static int __init ip_rt_proc_init(void) 382 { 383 return register_pernet_subsys(&ip_rt_proc_ops); 384 } 385 386 #else 387 static inline int ip_rt_proc_init(void) 388 { 389 return 0; 390 } 391 #endif /* CONFIG_PROC_FS */ 392 393 static inline bool rt_is_expired(const struct rtable *rth) 394 { 395 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 396 } 397 398 void rt_cache_flush(struct net *net) 399 { 400 rt_genid_bump_ipv4(net); 401 } 402 403 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 404 struct sk_buff *skb, 405 const void *daddr) 406 { 407 const struct rtable *rt = container_of(dst, struct rtable, dst); 408 struct net_device *dev = dst->dev; 409 struct neighbour *n; 410 411 rcu_read_lock_bh(); 412 413 if (likely(rt->rt_gw_family == AF_INET)) { 414 n = ip_neigh_gw4(dev, rt->rt_gw4); 415 } else if (rt->rt_gw_family == AF_INET6) { 416 n = ip_neigh_gw6(dev, &rt->rt_gw6); 417 } else { 418 __be32 pkey; 419 420 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 421 n = ip_neigh_gw4(dev, pkey); 422 } 423 424 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 425 n = NULL; 426 427 rcu_read_unlock_bh(); 428 429 return n; 430 } 431 432 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 433 { 434 const struct rtable *rt = container_of(dst, struct rtable, dst); 435 struct net_device *dev = dst->dev; 436 const __be32 *pkey = daddr; 437 438 if (rt->rt_gw_family == AF_INET) { 439 pkey = (const __be32 *)&rt->rt_gw4; 440 } else if (rt->rt_gw_family == AF_INET6) { 441 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 442 } else if (!daddr || 443 (rt->rt_flags & 444 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 445 return; 446 } 447 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 448 } 449 450 /* Hash tables of size 2048..262144 depending on RAM size. 451 * Each bucket uses 8 bytes. 452 */ 453 static u32 ip_idents_mask __read_mostly; 454 static atomic_t *ip_idents __read_mostly; 455 static u32 *ip_tstamps __read_mostly; 456 457 /* In order to protect privacy, we add a perturbation to identifiers 458 * if one generator is seldom used. This makes hard for an attacker 459 * to infer how many packets were sent between two points in time. 460 */ 461 u32 ip_idents_reserve(u32 hash, int segs) 462 { 463 u32 bucket, old, now = (u32)jiffies; 464 atomic_t *p_id; 465 u32 *p_tstamp; 466 u32 delta = 0; 467 468 bucket = hash & ip_idents_mask; 469 p_tstamp = ip_tstamps + bucket; 470 p_id = ip_idents + bucket; 471 old = READ_ONCE(*p_tstamp); 472 473 if (old != now && cmpxchg(p_tstamp, old, now) == old) 474 delta = prandom_u32_max(now - old); 475 476 /* If UBSAN reports an error there, please make sure your compiler 477 * supports -fno-strict-overflow before reporting it that was a bug 478 * in UBSAN, and it has been fixed in GCC-8. 479 */ 480 return atomic_add_return(segs + delta, p_id) - segs; 481 } 482 EXPORT_SYMBOL(ip_idents_reserve); 483 484 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 485 { 486 u32 hash, id; 487 488 /* Note the following code is not safe, but this is okay. */ 489 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 490 get_random_bytes(&net->ipv4.ip_id_key, 491 sizeof(net->ipv4.ip_id_key)); 492 493 hash = siphash_3u32((__force u32)iph->daddr, 494 (__force u32)iph->saddr, 495 iph->protocol, 496 &net->ipv4.ip_id_key); 497 id = ip_idents_reserve(hash, segs); 498 iph->id = htons(id); 499 } 500 EXPORT_SYMBOL(__ip_select_ident); 501 502 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 503 const struct sock *sk, 504 const struct iphdr *iph, 505 int oif, u8 tos, 506 u8 prot, u32 mark, int flow_flags) 507 { 508 if (sk) { 509 const struct inet_sock *inet = inet_sk(sk); 510 511 oif = sk->sk_bound_dev_if; 512 mark = sk->sk_mark; 513 tos = RT_CONN_FLAGS(sk); 514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 515 } 516 flowi4_init_output(fl4, oif, mark, tos, 517 RT_SCOPE_UNIVERSE, prot, 518 flow_flags, 519 iph->daddr, iph->saddr, 0, 0, 520 sock_net_uid(net, sk)); 521 } 522 523 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 524 const struct sock *sk) 525 { 526 const struct net *net = dev_net(skb->dev); 527 const struct iphdr *iph = ip_hdr(skb); 528 int oif = skb->dev->ifindex; 529 u8 tos = RT_TOS(iph->tos); 530 u8 prot = iph->protocol; 531 u32 mark = skb->mark; 532 533 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 534 } 535 536 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 537 { 538 const struct inet_sock *inet = inet_sk(sk); 539 const struct ip_options_rcu *inet_opt; 540 __be32 daddr = inet->inet_daddr; 541 542 rcu_read_lock(); 543 inet_opt = rcu_dereference(inet->inet_opt); 544 if (inet_opt && inet_opt->opt.srr) 545 daddr = inet_opt->opt.faddr; 546 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 547 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 548 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 549 inet_sk_flowi_flags(sk), 550 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 551 rcu_read_unlock(); 552 } 553 554 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 555 const struct sk_buff *skb) 556 { 557 if (skb) 558 build_skb_flow_key(fl4, skb, sk); 559 else 560 build_sk_flow_key(fl4, sk); 561 } 562 563 static DEFINE_SPINLOCK(fnhe_lock); 564 565 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 566 { 567 struct rtable *rt; 568 569 rt = rcu_dereference(fnhe->fnhe_rth_input); 570 if (rt) { 571 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 572 dst_dev_put(&rt->dst); 573 dst_release(&rt->dst); 574 } 575 rt = rcu_dereference(fnhe->fnhe_rth_output); 576 if (rt) { 577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 578 dst_dev_put(&rt->dst); 579 dst_release(&rt->dst); 580 } 581 } 582 583 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 584 { 585 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 586 struct fib_nh_exception *fnhe, *oldest = NULL; 587 588 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 589 fnhe = rcu_dereference_protected(*fnhe_p, 590 lockdep_is_held(&fnhe_lock)); 591 if (!fnhe) 592 break; 593 if (!oldest || 594 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 595 oldest = fnhe; 596 oldest_p = fnhe_p; 597 } 598 } 599 fnhe_flush_routes(oldest); 600 *oldest_p = oldest->fnhe_next; 601 kfree_rcu(oldest, rcu); 602 } 603 604 static u32 fnhe_hashfun(__be32 daddr) 605 { 606 static siphash_aligned_key_t fnhe_hash_key; 607 u64 hval; 608 609 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 610 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 611 return hash_64(hval, FNHE_HASH_SHIFT); 612 } 613 614 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 615 { 616 rt->rt_pmtu = fnhe->fnhe_pmtu; 617 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 618 rt->dst.expires = fnhe->fnhe_expires; 619 620 if (fnhe->fnhe_gw) { 621 rt->rt_flags |= RTCF_REDIRECTED; 622 rt->rt_uses_gateway = 1; 623 rt->rt_gw_family = AF_INET; 624 rt->rt_gw4 = fnhe->fnhe_gw; 625 } 626 } 627 628 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 629 __be32 gw, u32 pmtu, bool lock, 630 unsigned long expires) 631 { 632 struct fnhe_hash_bucket *hash; 633 struct fib_nh_exception *fnhe; 634 struct rtable *rt; 635 u32 genid, hval; 636 unsigned int i; 637 int depth; 638 639 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 640 hval = fnhe_hashfun(daddr); 641 642 spin_lock_bh(&fnhe_lock); 643 644 hash = rcu_dereference(nhc->nhc_exceptions); 645 if (!hash) { 646 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 647 if (!hash) 648 goto out_unlock; 649 rcu_assign_pointer(nhc->nhc_exceptions, hash); 650 } 651 652 hash += hval; 653 654 depth = 0; 655 for (fnhe = rcu_dereference(hash->chain); fnhe; 656 fnhe = rcu_dereference(fnhe->fnhe_next)) { 657 if (fnhe->fnhe_daddr == daddr) 658 break; 659 depth++; 660 } 661 662 if (fnhe) { 663 if (fnhe->fnhe_genid != genid) 664 fnhe->fnhe_genid = genid; 665 if (gw) 666 fnhe->fnhe_gw = gw; 667 if (pmtu) { 668 fnhe->fnhe_pmtu = pmtu; 669 fnhe->fnhe_mtu_locked = lock; 670 } 671 fnhe->fnhe_expires = max(1UL, expires); 672 /* Update all cached dsts too */ 673 rt = rcu_dereference(fnhe->fnhe_rth_input); 674 if (rt) 675 fill_route_from_fnhe(rt, fnhe); 676 rt = rcu_dereference(fnhe->fnhe_rth_output); 677 if (rt) 678 fill_route_from_fnhe(rt, fnhe); 679 } else { 680 /* Randomize max depth to avoid some side channels attacks. */ 681 int max_depth = FNHE_RECLAIM_DEPTH + 682 prandom_u32_max(FNHE_RECLAIM_DEPTH); 683 684 while (depth > max_depth) { 685 fnhe_remove_oldest(hash); 686 depth--; 687 } 688 689 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 690 if (!fnhe) 691 goto out_unlock; 692 693 fnhe->fnhe_next = hash->chain; 694 695 fnhe->fnhe_genid = genid; 696 fnhe->fnhe_daddr = daddr; 697 fnhe->fnhe_gw = gw; 698 fnhe->fnhe_pmtu = pmtu; 699 fnhe->fnhe_mtu_locked = lock; 700 fnhe->fnhe_expires = max(1UL, expires); 701 702 rcu_assign_pointer(hash->chain, fnhe); 703 704 /* Exception created; mark the cached routes for the nexthop 705 * stale, so anyone caching it rechecks if this exception 706 * applies to them. 707 */ 708 rt = rcu_dereference(nhc->nhc_rth_input); 709 if (rt) 710 rt->dst.obsolete = DST_OBSOLETE_KILL; 711 712 for_each_possible_cpu(i) { 713 struct rtable __rcu **prt; 714 715 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 716 rt = rcu_dereference(*prt); 717 if (rt) 718 rt->dst.obsolete = DST_OBSOLETE_KILL; 719 } 720 } 721 722 fnhe->fnhe_stamp = jiffies; 723 724 out_unlock: 725 spin_unlock_bh(&fnhe_lock); 726 } 727 728 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 729 bool kill_route) 730 { 731 __be32 new_gw = icmp_hdr(skb)->un.gateway; 732 __be32 old_gw = ip_hdr(skb)->saddr; 733 struct net_device *dev = skb->dev; 734 struct in_device *in_dev; 735 struct fib_result res; 736 struct neighbour *n; 737 struct net *net; 738 739 switch (icmp_hdr(skb)->code & 7) { 740 case ICMP_REDIR_NET: 741 case ICMP_REDIR_NETTOS: 742 case ICMP_REDIR_HOST: 743 case ICMP_REDIR_HOSTTOS: 744 break; 745 746 default: 747 return; 748 } 749 750 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 751 return; 752 753 in_dev = __in_dev_get_rcu(dev); 754 if (!in_dev) 755 return; 756 757 net = dev_net(dev); 758 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 759 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 760 ipv4_is_zeronet(new_gw)) 761 goto reject_redirect; 762 763 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 764 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 765 goto reject_redirect; 766 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 767 goto reject_redirect; 768 } else { 769 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 770 goto reject_redirect; 771 } 772 773 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 774 if (!n) 775 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 776 if (!IS_ERR(n)) { 777 if (!(n->nud_state & NUD_VALID)) { 778 neigh_event_send(n, NULL); 779 } else { 780 if (fib_lookup(net, fl4, &res, 0) == 0) { 781 struct fib_nh_common *nhc; 782 783 fib_select_path(net, &res, fl4, skb); 784 nhc = FIB_RES_NHC(res); 785 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 786 0, false, 787 jiffies + ip_rt_gc_timeout); 788 } 789 if (kill_route) 790 rt->dst.obsolete = DST_OBSOLETE_KILL; 791 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 792 } 793 neigh_release(n); 794 } 795 return; 796 797 reject_redirect: 798 #ifdef CONFIG_IP_ROUTE_VERBOSE 799 if (IN_DEV_LOG_MARTIANS(in_dev)) { 800 const struct iphdr *iph = (const struct iphdr *) skb->data; 801 __be32 daddr = iph->daddr; 802 __be32 saddr = iph->saddr; 803 804 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 805 " Advised path = %pI4 -> %pI4\n", 806 &old_gw, dev->name, &new_gw, 807 &saddr, &daddr); 808 } 809 #endif 810 ; 811 } 812 813 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 814 { 815 struct rtable *rt; 816 struct flowi4 fl4; 817 const struct iphdr *iph = (const struct iphdr *) skb->data; 818 struct net *net = dev_net(skb->dev); 819 int oif = skb->dev->ifindex; 820 u8 tos = RT_TOS(iph->tos); 821 u8 prot = iph->protocol; 822 u32 mark = skb->mark; 823 824 rt = (struct rtable *) dst; 825 826 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 827 __ip_do_redirect(rt, skb, &fl4, true); 828 } 829 830 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 831 { 832 struct rtable *rt = (struct rtable *)dst; 833 struct dst_entry *ret = dst; 834 835 if (rt) { 836 if (dst->obsolete > 0) { 837 ip_rt_put(rt); 838 ret = NULL; 839 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 840 rt->dst.expires) { 841 ip_rt_put(rt); 842 ret = NULL; 843 } 844 } 845 return ret; 846 } 847 848 /* 849 * Algorithm: 850 * 1. The first ip_rt_redirect_number redirects are sent 851 * with exponential backoff, then we stop sending them at all, 852 * assuming that the host ignores our redirects. 853 * 2. If we did not see packets requiring redirects 854 * during ip_rt_redirect_silence, we assume that the host 855 * forgot redirected route and start to send redirects again. 856 * 857 * This algorithm is much cheaper and more intelligent than dumb load limiting 858 * in icmp.c. 859 * 860 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 861 * and "frag. need" (breaks PMTU discovery) in icmp.c. 862 */ 863 864 void ip_rt_send_redirect(struct sk_buff *skb) 865 { 866 struct rtable *rt = skb_rtable(skb); 867 struct in_device *in_dev; 868 struct inet_peer *peer; 869 struct net *net; 870 int log_martians; 871 int vif; 872 873 rcu_read_lock(); 874 in_dev = __in_dev_get_rcu(rt->dst.dev); 875 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 876 rcu_read_unlock(); 877 return; 878 } 879 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 880 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 881 rcu_read_unlock(); 882 883 net = dev_net(rt->dst.dev); 884 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 885 if (!peer) { 886 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 887 rt_nexthop(rt, ip_hdr(skb)->daddr)); 888 return; 889 } 890 891 /* No redirected packets during ip_rt_redirect_silence; 892 * reset the algorithm. 893 */ 894 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 895 peer->rate_tokens = 0; 896 peer->n_redirects = 0; 897 } 898 899 /* Too many ignored redirects; do not send anything 900 * set dst.rate_last to the last seen redirected packet. 901 */ 902 if (peer->n_redirects >= ip_rt_redirect_number) { 903 peer->rate_last = jiffies; 904 goto out_put_peer; 905 } 906 907 /* Check for load limit; set rate_last to the latest sent 908 * redirect. 909 */ 910 if (peer->n_redirects == 0 || 911 time_after(jiffies, 912 (peer->rate_last + 913 (ip_rt_redirect_load << peer->n_redirects)))) { 914 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 915 916 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 917 peer->rate_last = jiffies; 918 ++peer->n_redirects; 919 #ifdef CONFIG_IP_ROUTE_VERBOSE 920 if (log_martians && 921 peer->n_redirects == ip_rt_redirect_number) 922 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 923 &ip_hdr(skb)->saddr, inet_iif(skb), 924 &ip_hdr(skb)->daddr, &gw); 925 #endif 926 } 927 out_put_peer: 928 inet_putpeer(peer); 929 } 930 931 static int ip_error(struct sk_buff *skb) 932 { 933 struct rtable *rt = skb_rtable(skb); 934 struct net_device *dev = skb->dev; 935 struct in_device *in_dev; 936 struct inet_peer *peer; 937 unsigned long now; 938 struct net *net; 939 bool send; 940 int code; 941 942 if (netif_is_l3_master(skb->dev)) { 943 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 944 if (!dev) 945 goto out; 946 } 947 948 in_dev = __in_dev_get_rcu(dev); 949 950 /* IP on this device is disabled. */ 951 if (!in_dev) 952 goto out; 953 954 net = dev_net(rt->dst.dev); 955 if (!IN_DEV_FORWARD(in_dev)) { 956 switch (rt->dst.error) { 957 case EHOSTUNREACH: 958 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 959 break; 960 961 case ENETUNREACH: 962 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 963 break; 964 } 965 goto out; 966 } 967 968 switch (rt->dst.error) { 969 case EINVAL: 970 default: 971 goto out; 972 case EHOSTUNREACH: 973 code = ICMP_HOST_UNREACH; 974 break; 975 case ENETUNREACH: 976 code = ICMP_NET_UNREACH; 977 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 978 break; 979 case EACCES: 980 code = ICMP_PKT_FILTERED; 981 break; 982 } 983 984 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 985 l3mdev_master_ifindex(skb->dev), 1); 986 987 send = true; 988 if (peer) { 989 now = jiffies; 990 peer->rate_tokens += now - peer->rate_last; 991 if (peer->rate_tokens > ip_rt_error_burst) 992 peer->rate_tokens = ip_rt_error_burst; 993 peer->rate_last = now; 994 if (peer->rate_tokens >= ip_rt_error_cost) 995 peer->rate_tokens -= ip_rt_error_cost; 996 else 997 send = false; 998 inet_putpeer(peer); 999 } 1000 if (send) 1001 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1002 1003 out: kfree_skb(skb); 1004 return 0; 1005 } 1006 1007 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1008 { 1009 struct dst_entry *dst = &rt->dst; 1010 struct net *net = dev_net(dst->dev); 1011 struct fib_result res; 1012 bool lock = false; 1013 u32 old_mtu; 1014 1015 if (ip_mtu_locked(dst)) 1016 return; 1017 1018 old_mtu = ipv4_mtu(dst); 1019 if (old_mtu < mtu) 1020 return; 1021 1022 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1023 lock = true; 1024 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1025 } 1026 1027 if (rt->rt_pmtu == mtu && !lock && 1028 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1029 return; 1030 1031 rcu_read_lock(); 1032 if (fib_lookup(net, fl4, &res, 0) == 0) { 1033 struct fib_nh_common *nhc; 1034 1035 fib_select_path(net, &res, fl4, NULL); 1036 nhc = FIB_RES_NHC(res); 1037 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1038 jiffies + net->ipv4.ip_rt_mtu_expires); 1039 } 1040 rcu_read_unlock(); 1041 } 1042 1043 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1044 struct sk_buff *skb, u32 mtu, 1045 bool confirm_neigh) 1046 { 1047 struct rtable *rt = (struct rtable *) dst; 1048 struct flowi4 fl4; 1049 1050 ip_rt_build_flow_key(&fl4, sk, skb); 1051 1052 /* Don't make lookup fail for bridged encapsulations */ 1053 if (skb && netif_is_any_bridge_port(skb->dev)) 1054 fl4.flowi4_oif = 0; 1055 1056 __ip_rt_update_pmtu(rt, &fl4, mtu); 1057 } 1058 1059 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1060 int oif, u8 protocol) 1061 { 1062 const struct iphdr *iph = (const struct iphdr *)skb->data; 1063 struct flowi4 fl4; 1064 struct rtable *rt; 1065 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1066 1067 __build_flow_key(net, &fl4, NULL, iph, oif, 1068 RT_TOS(iph->tos), protocol, mark, 0); 1069 rt = __ip_route_output_key(net, &fl4); 1070 if (!IS_ERR(rt)) { 1071 __ip_rt_update_pmtu(rt, &fl4, mtu); 1072 ip_rt_put(rt); 1073 } 1074 } 1075 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1076 1077 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1078 { 1079 const struct iphdr *iph = (const struct iphdr *)skb->data; 1080 struct flowi4 fl4; 1081 struct rtable *rt; 1082 1083 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1084 1085 if (!fl4.flowi4_mark) 1086 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1087 1088 rt = __ip_route_output_key(sock_net(sk), &fl4); 1089 if (!IS_ERR(rt)) { 1090 __ip_rt_update_pmtu(rt, &fl4, mtu); 1091 ip_rt_put(rt); 1092 } 1093 } 1094 1095 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1096 { 1097 const struct iphdr *iph = (const struct iphdr *)skb->data; 1098 struct flowi4 fl4; 1099 struct rtable *rt; 1100 struct dst_entry *odst = NULL; 1101 bool new = false; 1102 struct net *net = sock_net(sk); 1103 1104 bh_lock_sock(sk); 1105 1106 if (!ip_sk_accept_pmtu(sk)) 1107 goto out; 1108 1109 odst = sk_dst_get(sk); 1110 1111 if (sock_owned_by_user(sk) || !odst) { 1112 __ipv4_sk_update_pmtu(skb, sk, mtu); 1113 goto out; 1114 } 1115 1116 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1117 1118 rt = (struct rtable *)odst; 1119 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1120 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1121 if (IS_ERR(rt)) 1122 goto out; 1123 1124 new = true; 1125 } 1126 1127 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1128 1129 if (!dst_check(&rt->dst, 0)) { 1130 if (new) 1131 dst_release(&rt->dst); 1132 1133 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1134 if (IS_ERR(rt)) 1135 goto out; 1136 1137 new = true; 1138 } 1139 1140 if (new) 1141 sk_dst_set(sk, &rt->dst); 1142 1143 out: 1144 bh_unlock_sock(sk); 1145 dst_release(odst); 1146 } 1147 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1148 1149 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1150 int oif, u8 protocol) 1151 { 1152 const struct iphdr *iph = (const struct iphdr *)skb->data; 1153 struct flowi4 fl4; 1154 struct rtable *rt; 1155 1156 __build_flow_key(net, &fl4, NULL, iph, oif, 1157 RT_TOS(iph->tos), protocol, 0, 0); 1158 rt = __ip_route_output_key(net, &fl4); 1159 if (!IS_ERR(rt)) { 1160 __ip_do_redirect(rt, skb, &fl4, false); 1161 ip_rt_put(rt); 1162 } 1163 } 1164 EXPORT_SYMBOL_GPL(ipv4_redirect); 1165 1166 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1167 { 1168 const struct iphdr *iph = (const struct iphdr *)skb->data; 1169 struct flowi4 fl4; 1170 struct rtable *rt; 1171 struct net *net = sock_net(sk); 1172 1173 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1174 rt = __ip_route_output_key(net, &fl4); 1175 if (!IS_ERR(rt)) { 1176 __ip_do_redirect(rt, skb, &fl4, false); 1177 ip_rt_put(rt); 1178 } 1179 } 1180 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1181 1182 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1183 u32 cookie) 1184 { 1185 struct rtable *rt = (struct rtable *) dst; 1186 1187 /* All IPV4 dsts are created with ->obsolete set to the value 1188 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1189 * into this function always. 1190 * 1191 * When a PMTU/redirect information update invalidates a route, 1192 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1193 * DST_OBSOLETE_DEAD. 1194 */ 1195 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1196 return NULL; 1197 return dst; 1198 } 1199 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1200 1201 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1202 { 1203 struct ip_options opt; 1204 int res; 1205 1206 /* Recompile ip options since IPCB may not be valid anymore. 1207 * Also check we have a reasonable ipv4 header. 1208 */ 1209 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1210 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1211 return; 1212 1213 memset(&opt, 0, sizeof(opt)); 1214 if (ip_hdr(skb)->ihl > 5) { 1215 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1216 return; 1217 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1218 1219 rcu_read_lock(); 1220 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1221 rcu_read_unlock(); 1222 1223 if (res) 1224 return; 1225 } 1226 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1227 } 1228 1229 static void ipv4_link_failure(struct sk_buff *skb) 1230 { 1231 struct rtable *rt; 1232 1233 ipv4_send_dest_unreach(skb); 1234 1235 rt = skb_rtable(skb); 1236 if (rt) 1237 dst_set_expires(&rt->dst, 0); 1238 } 1239 1240 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1241 { 1242 pr_debug("%s: %pI4 -> %pI4, %s\n", 1243 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1244 skb->dev ? skb->dev->name : "?"); 1245 kfree_skb(skb); 1246 WARN_ON(1); 1247 return 0; 1248 } 1249 1250 /* 1251 * We do not cache source address of outgoing interface, 1252 * because it is used only by IP RR, TS and SRR options, 1253 * so that it out of fast path. 1254 * 1255 * BTW remember: "addr" is allowed to be not aligned 1256 * in IP options! 1257 */ 1258 1259 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1260 { 1261 __be32 src; 1262 1263 if (rt_is_output_route(rt)) 1264 src = ip_hdr(skb)->saddr; 1265 else { 1266 struct fib_result res; 1267 struct iphdr *iph = ip_hdr(skb); 1268 struct flowi4 fl4 = { 1269 .daddr = iph->daddr, 1270 .saddr = iph->saddr, 1271 .flowi4_tos = RT_TOS(iph->tos), 1272 .flowi4_oif = rt->dst.dev->ifindex, 1273 .flowi4_iif = skb->dev->ifindex, 1274 .flowi4_mark = skb->mark, 1275 }; 1276 1277 rcu_read_lock(); 1278 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1279 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1280 else 1281 src = inet_select_addr(rt->dst.dev, 1282 rt_nexthop(rt, iph->daddr), 1283 RT_SCOPE_UNIVERSE); 1284 rcu_read_unlock(); 1285 } 1286 memcpy(addr, &src, 4); 1287 } 1288 1289 #ifdef CONFIG_IP_ROUTE_CLASSID 1290 static void set_class_tag(struct rtable *rt, u32 tag) 1291 { 1292 if (!(rt->dst.tclassid & 0xFFFF)) 1293 rt->dst.tclassid |= tag & 0xFFFF; 1294 if (!(rt->dst.tclassid & 0xFFFF0000)) 1295 rt->dst.tclassid |= tag & 0xFFFF0000; 1296 } 1297 #endif 1298 1299 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1300 { 1301 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1302 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1303 ip_rt_min_advmss); 1304 1305 return min(advmss, IPV4_MAX_PMTU - header_size); 1306 } 1307 1308 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1309 { 1310 return ip_dst_mtu_maybe_forward(dst, false); 1311 } 1312 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1313 1314 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1315 { 1316 struct fnhe_hash_bucket *hash; 1317 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1318 u32 hval = fnhe_hashfun(daddr); 1319 1320 spin_lock_bh(&fnhe_lock); 1321 1322 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1323 lockdep_is_held(&fnhe_lock)); 1324 hash += hval; 1325 1326 fnhe_p = &hash->chain; 1327 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1328 while (fnhe) { 1329 if (fnhe->fnhe_daddr == daddr) { 1330 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1331 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1332 /* set fnhe_daddr to 0 to ensure it won't bind with 1333 * new dsts in rt_bind_exception(). 1334 */ 1335 fnhe->fnhe_daddr = 0; 1336 fnhe_flush_routes(fnhe); 1337 kfree_rcu(fnhe, rcu); 1338 break; 1339 } 1340 fnhe_p = &fnhe->fnhe_next; 1341 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1342 lockdep_is_held(&fnhe_lock)); 1343 } 1344 1345 spin_unlock_bh(&fnhe_lock); 1346 } 1347 1348 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1349 __be32 daddr) 1350 { 1351 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1352 struct fib_nh_exception *fnhe; 1353 u32 hval; 1354 1355 if (!hash) 1356 return NULL; 1357 1358 hval = fnhe_hashfun(daddr); 1359 1360 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1361 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1362 if (fnhe->fnhe_daddr == daddr) { 1363 if (fnhe->fnhe_expires && 1364 time_after(jiffies, fnhe->fnhe_expires)) { 1365 ip_del_fnhe(nhc, daddr); 1366 break; 1367 } 1368 return fnhe; 1369 } 1370 } 1371 return NULL; 1372 } 1373 1374 /* MTU selection: 1375 * 1. mtu on route is locked - use it 1376 * 2. mtu from nexthop exception 1377 * 3. mtu from egress device 1378 */ 1379 1380 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1381 { 1382 struct fib_nh_common *nhc = res->nhc; 1383 struct net_device *dev = nhc->nhc_dev; 1384 struct fib_info *fi = res->fi; 1385 u32 mtu = 0; 1386 1387 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1388 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1389 mtu = fi->fib_mtu; 1390 1391 if (likely(!mtu)) { 1392 struct fib_nh_exception *fnhe; 1393 1394 fnhe = find_exception(nhc, daddr); 1395 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1396 mtu = fnhe->fnhe_pmtu; 1397 } 1398 1399 if (likely(!mtu)) 1400 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1401 1402 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1403 } 1404 1405 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1406 __be32 daddr, const bool do_cache) 1407 { 1408 bool ret = false; 1409 1410 spin_lock_bh(&fnhe_lock); 1411 1412 if (daddr == fnhe->fnhe_daddr) { 1413 struct rtable __rcu **porig; 1414 struct rtable *orig; 1415 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1416 1417 if (rt_is_input_route(rt)) 1418 porig = &fnhe->fnhe_rth_input; 1419 else 1420 porig = &fnhe->fnhe_rth_output; 1421 orig = rcu_dereference(*porig); 1422 1423 if (fnhe->fnhe_genid != genid) { 1424 fnhe->fnhe_genid = genid; 1425 fnhe->fnhe_gw = 0; 1426 fnhe->fnhe_pmtu = 0; 1427 fnhe->fnhe_expires = 0; 1428 fnhe->fnhe_mtu_locked = false; 1429 fnhe_flush_routes(fnhe); 1430 orig = NULL; 1431 } 1432 fill_route_from_fnhe(rt, fnhe); 1433 if (!rt->rt_gw4) { 1434 rt->rt_gw4 = daddr; 1435 rt->rt_gw_family = AF_INET; 1436 } 1437 1438 if (do_cache) { 1439 dst_hold(&rt->dst); 1440 rcu_assign_pointer(*porig, rt); 1441 if (orig) { 1442 dst_dev_put(&orig->dst); 1443 dst_release(&orig->dst); 1444 } 1445 ret = true; 1446 } 1447 1448 fnhe->fnhe_stamp = jiffies; 1449 } 1450 spin_unlock_bh(&fnhe_lock); 1451 1452 return ret; 1453 } 1454 1455 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1456 { 1457 struct rtable *orig, *prev, **p; 1458 bool ret = true; 1459 1460 if (rt_is_input_route(rt)) { 1461 p = (struct rtable **)&nhc->nhc_rth_input; 1462 } else { 1463 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1464 } 1465 orig = *p; 1466 1467 /* hold dst before doing cmpxchg() to avoid race condition 1468 * on this dst 1469 */ 1470 dst_hold(&rt->dst); 1471 prev = cmpxchg(p, orig, rt); 1472 if (prev == orig) { 1473 if (orig) { 1474 rt_add_uncached_list(orig); 1475 dst_release(&orig->dst); 1476 } 1477 } else { 1478 dst_release(&rt->dst); 1479 ret = false; 1480 } 1481 1482 return ret; 1483 } 1484 1485 struct uncached_list { 1486 spinlock_t lock; 1487 struct list_head head; 1488 }; 1489 1490 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1491 1492 void rt_add_uncached_list(struct rtable *rt) 1493 { 1494 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1495 1496 rt->rt_uncached_list = ul; 1497 1498 spin_lock_bh(&ul->lock); 1499 list_add_tail(&rt->rt_uncached, &ul->head); 1500 spin_unlock_bh(&ul->lock); 1501 } 1502 1503 void rt_del_uncached_list(struct rtable *rt) 1504 { 1505 if (!list_empty(&rt->rt_uncached)) { 1506 struct uncached_list *ul = rt->rt_uncached_list; 1507 1508 spin_lock_bh(&ul->lock); 1509 list_del(&rt->rt_uncached); 1510 spin_unlock_bh(&ul->lock); 1511 } 1512 } 1513 1514 static void ipv4_dst_destroy(struct dst_entry *dst) 1515 { 1516 struct rtable *rt = (struct rtable *)dst; 1517 1518 ip_dst_metrics_put(dst); 1519 rt_del_uncached_list(rt); 1520 } 1521 1522 void rt_flush_dev(struct net_device *dev) 1523 { 1524 struct rtable *rt; 1525 int cpu; 1526 1527 for_each_possible_cpu(cpu) { 1528 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1529 1530 spin_lock_bh(&ul->lock); 1531 list_for_each_entry(rt, &ul->head, rt_uncached) { 1532 if (rt->dst.dev != dev) 1533 continue; 1534 rt->dst.dev = blackhole_netdev; 1535 dev_replace_track(dev, blackhole_netdev, 1536 &rt->dst.dev_tracker, 1537 GFP_ATOMIC); 1538 } 1539 spin_unlock_bh(&ul->lock); 1540 } 1541 } 1542 1543 static bool rt_cache_valid(const struct rtable *rt) 1544 { 1545 return rt && 1546 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1547 !rt_is_expired(rt); 1548 } 1549 1550 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1551 const struct fib_result *res, 1552 struct fib_nh_exception *fnhe, 1553 struct fib_info *fi, u16 type, u32 itag, 1554 const bool do_cache) 1555 { 1556 bool cached = false; 1557 1558 if (fi) { 1559 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1560 1561 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1562 rt->rt_uses_gateway = 1; 1563 rt->rt_gw_family = nhc->nhc_gw_family; 1564 /* only INET and INET6 are supported */ 1565 if (likely(nhc->nhc_gw_family == AF_INET)) 1566 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1567 else 1568 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1569 } 1570 1571 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1572 1573 #ifdef CONFIG_IP_ROUTE_CLASSID 1574 if (nhc->nhc_family == AF_INET) { 1575 struct fib_nh *nh; 1576 1577 nh = container_of(nhc, struct fib_nh, nh_common); 1578 rt->dst.tclassid = nh->nh_tclassid; 1579 } 1580 #endif 1581 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1582 if (unlikely(fnhe)) 1583 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1584 else if (do_cache) 1585 cached = rt_cache_route(nhc, rt); 1586 if (unlikely(!cached)) { 1587 /* Routes we intend to cache in nexthop exception or 1588 * FIB nexthop have the DST_NOCACHE bit clear. 1589 * However, if we are unsuccessful at storing this 1590 * route into the cache we really need to set it. 1591 */ 1592 if (!rt->rt_gw4) { 1593 rt->rt_gw_family = AF_INET; 1594 rt->rt_gw4 = daddr; 1595 } 1596 rt_add_uncached_list(rt); 1597 } 1598 } else 1599 rt_add_uncached_list(rt); 1600 1601 #ifdef CONFIG_IP_ROUTE_CLASSID 1602 #ifdef CONFIG_IP_MULTIPLE_TABLES 1603 set_class_tag(rt, res->tclassid); 1604 #endif 1605 set_class_tag(rt, itag); 1606 #endif 1607 } 1608 1609 struct rtable *rt_dst_alloc(struct net_device *dev, 1610 unsigned int flags, u16 type, 1611 bool nopolicy, bool noxfrm) 1612 { 1613 struct rtable *rt; 1614 1615 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1616 (nopolicy ? DST_NOPOLICY : 0) | 1617 (noxfrm ? DST_NOXFRM : 0)); 1618 1619 if (rt) { 1620 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1621 rt->rt_flags = flags; 1622 rt->rt_type = type; 1623 rt->rt_is_input = 0; 1624 rt->rt_iif = 0; 1625 rt->rt_pmtu = 0; 1626 rt->rt_mtu_locked = 0; 1627 rt->rt_uses_gateway = 0; 1628 rt->rt_gw_family = 0; 1629 rt->rt_gw4 = 0; 1630 INIT_LIST_HEAD(&rt->rt_uncached); 1631 1632 rt->dst.output = ip_output; 1633 if (flags & RTCF_LOCAL) 1634 rt->dst.input = ip_local_deliver; 1635 } 1636 1637 return rt; 1638 } 1639 EXPORT_SYMBOL(rt_dst_alloc); 1640 1641 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1642 { 1643 struct rtable *new_rt; 1644 1645 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1646 rt->dst.flags); 1647 1648 if (new_rt) { 1649 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1650 new_rt->rt_flags = rt->rt_flags; 1651 new_rt->rt_type = rt->rt_type; 1652 new_rt->rt_is_input = rt->rt_is_input; 1653 new_rt->rt_iif = rt->rt_iif; 1654 new_rt->rt_pmtu = rt->rt_pmtu; 1655 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1656 new_rt->rt_gw_family = rt->rt_gw_family; 1657 if (rt->rt_gw_family == AF_INET) 1658 new_rt->rt_gw4 = rt->rt_gw4; 1659 else if (rt->rt_gw_family == AF_INET6) 1660 new_rt->rt_gw6 = rt->rt_gw6; 1661 INIT_LIST_HEAD(&new_rt->rt_uncached); 1662 1663 new_rt->dst.input = rt->dst.input; 1664 new_rt->dst.output = rt->dst.output; 1665 new_rt->dst.error = rt->dst.error; 1666 new_rt->dst.lastuse = jiffies; 1667 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1668 } 1669 return new_rt; 1670 } 1671 EXPORT_SYMBOL(rt_dst_clone); 1672 1673 /* called in rcu_read_lock() section */ 1674 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1675 u8 tos, struct net_device *dev, 1676 struct in_device *in_dev, u32 *itag) 1677 { 1678 int err; 1679 1680 /* Primary sanity checks. */ 1681 if (!in_dev) 1682 return -EINVAL; 1683 1684 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1685 skb->protocol != htons(ETH_P_IP)) 1686 return -EINVAL; 1687 1688 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1689 return -EINVAL; 1690 1691 if (ipv4_is_zeronet(saddr)) { 1692 if (!ipv4_is_local_multicast(daddr) && 1693 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1694 return -EINVAL; 1695 } else { 1696 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1697 in_dev, itag); 1698 if (err < 0) 1699 return err; 1700 } 1701 return 0; 1702 } 1703 1704 /* called in rcu_read_lock() section */ 1705 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1706 u8 tos, struct net_device *dev, int our) 1707 { 1708 struct in_device *in_dev = __in_dev_get_rcu(dev); 1709 unsigned int flags = RTCF_MULTICAST; 1710 struct rtable *rth; 1711 u32 itag = 0; 1712 int err; 1713 1714 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1715 if (err) 1716 return err; 1717 1718 if (our) 1719 flags |= RTCF_LOCAL; 1720 1721 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1722 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 1723 if (!rth) 1724 return -ENOBUFS; 1725 1726 #ifdef CONFIG_IP_ROUTE_CLASSID 1727 rth->dst.tclassid = itag; 1728 #endif 1729 rth->dst.output = ip_rt_bug; 1730 rth->rt_is_input= 1; 1731 1732 #ifdef CONFIG_IP_MROUTE 1733 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1734 rth->dst.input = ip_mr_input; 1735 #endif 1736 RT_CACHE_STAT_INC(in_slow_mc); 1737 1738 skb_dst_set(skb, &rth->dst); 1739 return 0; 1740 } 1741 1742 1743 static void ip_handle_martian_source(struct net_device *dev, 1744 struct in_device *in_dev, 1745 struct sk_buff *skb, 1746 __be32 daddr, 1747 __be32 saddr) 1748 { 1749 RT_CACHE_STAT_INC(in_martian_src); 1750 #ifdef CONFIG_IP_ROUTE_VERBOSE 1751 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1752 /* 1753 * RFC1812 recommendation, if source is martian, 1754 * the only hint is MAC header. 1755 */ 1756 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1757 &daddr, &saddr, dev->name); 1758 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1759 print_hex_dump(KERN_WARNING, "ll header: ", 1760 DUMP_PREFIX_OFFSET, 16, 1, 1761 skb_mac_header(skb), 1762 dev->hard_header_len, false); 1763 } 1764 } 1765 #endif 1766 } 1767 1768 /* called in rcu_read_lock() section */ 1769 static int __mkroute_input(struct sk_buff *skb, 1770 const struct fib_result *res, 1771 struct in_device *in_dev, 1772 __be32 daddr, __be32 saddr, u32 tos) 1773 { 1774 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1775 struct net_device *dev = nhc->nhc_dev; 1776 struct fib_nh_exception *fnhe; 1777 struct rtable *rth; 1778 int err; 1779 struct in_device *out_dev; 1780 bool do_cache; 1781 u32 itag = 0; 1782 1783 /* get a working reference to the output device */ 1784 out_dev = __in_dev_get_rcu(dev); 1785 if (!out_dev) { 1786 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1787 return -EINVAL; 1788 } 1789 1790 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1791 in_dev->dev, in_dev, &itag); 1792 if (err < 0) { 1793 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1794 saddr); 1795 1796 goto cleanup; 1797 } 1798 1799 do_cache = res->fi && !itag; 1800 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1801 skb->protocol == htons(ETH_P_IP)) { 1802 __be32 gw; 1803 1804 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1805 if (IN_DEV_SHARED_MEDIA(out_dev) || 1806 inet_addr_onlink(out_dev, saddr, gw)) 1807 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1808 } 1809 1810 if (skb->protocol != htons(ETH_P_IP)) { 1811 /* Not IP (i.e. ARP). Do not create route, if it is 1812 * invalid for proxy arp. DNAT routes are always valid. 1813 * 1814 * Proxy arp feature have been extended to allow, ARP 1815 * replies back to the same interface, to support 1816 * Private VLAN switch technologies. See arp.c. 1817 */ 1818 if (out_dev == in_dev && 1819 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1820 err = -EINVAL; 1821 goto cleanup; 1822 } 1823 } 1824 1825 fnhe = find_exception(nhc, daddr); 1826 if (do_cache) { 1827 if (fnhe) 1828 rth = rcu_dereference(fnhe->fnhe_rth_input); 1829 else 1830 rth = rcu_dereference(nhc->nhc_rth_input); 1831 if (rt_cache_valid(rth)) { 1832 skb_dst_set_noref(skb, &rth->dst); 1833 goto out; 1834 } 1835 } 1836 1837 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1838 IN_DEV_ORCONF(in_dev, NOPOLICY), 1839 IN_DEV_ORCONF(out_dev, NOXFRM)); 1840 if (!rth) { 1841 err = -ENOBUFS; 1842 goto cleanup; 1843 } 1844 1845 rth->rt_is_input = 1; 1846 RT_CACHE_STAT_INC(in_slow_tot); 1847 1848 rth->dst.input = ip_forward; 1849 1850 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1851 do_cache); 1852 lwtunnel_set_redirect(&rth->dst); 1853 skb_dst_set(skb, &rth->dst); 1854 out: 1855 err = 0; 1856 cleanup: 1857 return err; 1858 } 1859 1860 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1861 /* To make ICMP packets follow the right flow, the multipath hash is 1862 * calculated from the inner IP addresses. 1863 */ 1864 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1865 struct flow_keys *hash_keys) 1866 { 1867 const struct iphdr *outer_iph = ip_hdr(skb); 1868 const struct iphdr *key_iph = outer_iph; 1869 const struct iphdr *inner_iph; 1870 const struct icmphdr *icmph; 1871 struct iphdr _inner_iph; 1872 struct icmphdr _icmph; 1873 1874 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1875 goto out; 1876 1877 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1878 goto out; 1879 1880 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1881 &_icmph); 1882 if (!icmph) 1883 goto out; 1884 1885 if (!icmp_is_err(icmph->type)) 1886 goto out; 1887 1888 inner_iph = skb_header_pointer(skb, 1889 outer_iph->ihl * 4 + sizeof(_icmph), 1890 sizeof(_inner_iph), &_inner_iph); 1891 if (!inner_iph) 1892 goto out; 1893 1894 key_iph = inner_iph; 1895 out: 1896 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1897 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1898 } 1899 1900 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1901 const struct sk_buff *skb, 1902 bool *p_has_inner) 1903 { 1904 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1905 struct flow_keys keys, hash_keys; 1906 1907 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1908 return 0; 1909 1910 memset(&hash_keys, 0, sizeof(hash_keys)); 1911 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1912 1913 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1914 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1915 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1916 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1917 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1918 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1919 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1920 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1921 hash_keys.ports.src = keys.ports.src; 1922 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1923 hash_keys.ports.dst = keys.ports.dst; 1924 1925 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1926 return flow_hash_from_keys(&hash_keys); 1927 } 1928 1929 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1930 const struct sk_buff *skb, 1931 bool has_inner) 1932 { 1933 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1934 struct flow_keys keys, hash_keys; 1935 1936 /* We assume the packet carries an encapsulation, but if none was 1937 * encountered during dissection of the outer flow, then there is no 1938 * point in calling the flow dissector again. 1939 */ 1940 if (!has_inner) 1941 return 0; 1942 1943 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1944 return 0; 1945 1946 memset(&hash_keys, 0, sizeof(hash_keys)); 1947 skb_flow_dissect_flow_keys(skb, &keys, 0); 1948 1949 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1950 return 0; 1951 1952 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1953 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1954 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1955 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1956 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1957 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1958 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1959 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1960 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1961 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1962 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1963 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1964 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1965 hash_keys.tags.flow_label = keys.tags.flow_label; 1966 } 1967 1968 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1969 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1970 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1971 hash_keys.ports.src = keys.ports.src; 1972 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1973 hash_keys.ports.dst = keys.ports.dst; 1974 1975 return flow_hash_from_keys(&hash_keys); 1976 } 1977 1978 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1979 const struct sk_buff *skb) 1980 { 1981 u32 mhash, mhash_inner; 1982 bool has_inner = true; 1983 1984 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 1985 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 1986 1987 return jhash_2words(mhash, mhash_inner, 0); 1988 } 1989 1990 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 1991 const struct flowi4 *fl4) 1992 { 1993 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1994 struct flow_keys hash_keys; 1995 1996 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1997 return 0; 1998 1999 memset(&hash_keys, 0, sizeof(hash_keys)); 2000 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2001 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2002 hash_keys.addrs.v4addrs.src = fl4->saddr; 2003 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2004 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2005 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2006 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2007 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2008 hash_keys.ports.src = fl4->fl4_sport; 2009 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2010 hash_keys.ports.dst = fl4->fl4_dport; 2011 2012 return flow_hash_from_keys(&hash_keys); 2013 } 2014 2015 /* if skb is set it will be used and fl4 can be NULL */ 2016 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2017 const struct sk_buff *skb, struct flow_keys *flkeys) 2018 { 2019 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2020 struct flow_keys hash_keys; 2021 u32 mhash = 0; 2022 2023 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2024 case 0: 2025 memset(&hash_keys, 0, sizeof(hash_keys)); 2026 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2027 if (skb) { 2028 ip_multipath_l3_keys(skb, &hash_keys); 2029 } else { 2030 hash_keys.addrs.v4addrs.src = fl4->saddr; 2031 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2032 } 2033 mhash = flow_hash_from_keys(&hash_keys); 2034 break; 2035 case 1: 2036 /* skb is currently provided only when forwarding */ 2037 if (skb) { 2038 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2039 struct flow_keys keys; 2040 2041 /* short-circuit if we already have L4 hash present */ 2042 if (skb->l4_hash) 2043 return skb_get_hash_raw(skb) >> 1; 2044 2045 memset(&hash_keys, 0, sizeof(hash_keys)); 2046 2047 if (!flkeys) { 2048 skb_flow_dissect_flow_keys(skb, &keys, flag); 2049 flkeys = &keys; 2050 } 2051 2052 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2053 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2054 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2055 hash_keys.ports.src = flkeys->ports.src; 2056 hash_keys.ports.dst = flkeys->ports.dst; 2057 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2058 } else { 2059 memset(&hash_keys, 0, sizeof(hash_keys)); 2060 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2061 hash_keys.addrs.v4addrs.src = fl4->saddr; 2062 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2063 hash_keys.ports.src = fl4->fl4_sport; 2064 hash_keys.ports.dst = fl4->fl4_dport; 2065 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2066 } 2067 mhash = flow_hash_from_keys(&hash_keys); 2068 break; 2069 case 2: 2070 memset(&hash_keys, 0, sizeof(hash_keys)); 2071 /* skb is currently provided only when forwarding */ 2072 if (skb) { 2073 struct flow_keys keys; 2074 2075 skb_flow_dissect_flow_keys(skb, &keys, 0); 2076 /* Inner can be v4 or v6 */ 2077 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2078 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2079 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2080 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2081 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2082 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2083 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2084 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2085 hash_keys.tags.flow_label = keys.tags.flow_label; 2086 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2087 } else { 2088 /* Same as case 0 */ 2089 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2090 ip_multipath_l3_keys(skb, &hash_keys); 2091 } 2092 } else { 2093 /* Same as case 0 */ 2094 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2095 hash_keys.addrs.v4addrs.src = fl4->saddr; 2096 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2097 } 2098 mhash = flow_hash_from_keys(&hash_keys); 2099 break; 2100 case 3: 2101 if (skb) 2102 mhash = fib_multipath_custom_hash_skb(net, skb); 2103 else 2104 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2105 break; 2106 } 2107 2108 if (multipath_hash) 2109 mhash = jhash_2words(mhash, multipath_hash, 0); 2110 2111 return mhash >> 1; 2112 } 2113 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2114 2115 static int ip_mkroute_input(struct sk_buff *skb, 2116 struct fib_result *res, 2117 struct in_device *in_dev, 2118 __be32 daddr, __be32 saddr, u32 tos, 2119 struct flow_keys *hkeys) 2120 { 2121 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2122 if (res->fi && fib_info_num_path(res->fi) > 1) { 2123 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2124 2125 fib_select_multipath(res, h); 2126 } 2127 #endif 2128 2129 /* create a routing cache entry */ 2130 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2131 } 2132 2133 /* Implements all the saddr-related checks as ip_route_input_slow(), 2134 * assuming daddr is valid and the destination is not a local broadcast one. 2135 * Uses the provided hint instead of performing a route lookup. 2136 */ 2137 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2138 u8 tos, struct net_device *dev, 2139 const struct sk_buff *hint) 2140 { 2141 struct in_device *in_dev = __in_dev_get_rcu(dev); 2142 struct rtable *rt = skb_rtable(hint); 2143 struct net *net = dev_net(dev); 2144 int err = -EINVAL; 2145 u32 tag = 0; 2146 2147 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2148 goto martian_source; 2149 2150 if (ipv4_is_zeronet(saddr)) 2151 goto martian_source; 2152 2153 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2154 goto martian_source; 2155 2156 if (rt->rt_type != RTN_LOCAL) 2157 goto skip_validate_source; 2158 2159 tos &= IPTOS_RT_MASK; 2160 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2161 if (err < 0) 2162 goto martian_source; 2163 2164 skip_validate_source: 2165 skb_dst_copy(skb, hint); 2166 return 0; 2167 2168 martian_source: 2169 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2170 return err; 2171 } 2172 2173 /* get device for dst_alloc with local routes */ 2174 static struct net_device *ip_rt_get_dev(struct net *net, 2175 const struct fib_result *res) 2176 { 2177 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2178 struct net_device *dev = NULL; 2179 2180 if (nhc) 2181 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2182 2183 return dev ? : net->loopback_dev; 2184 } 2185 2186 /* 2187 * NOTE. We drop all the packets that has local source 2188 * addresses, because every properly looped back packet 2189 * must have correct destination already attached by output routine. 2190 * Changes in the enforced policies must be applied also to 2191 * ip_route_use_hint(). 2192 * 2193 * Such approach solves two big problems: 2194 * 1. Not simplex devices are handled properly. 2195 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2196 * called with rcu_read_lock() 2197 */ 2198 2199 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2200 u8 tos, struct net_device *dev, 2201 struct fib_result *res) 2202 { 2203 struct in_device *in_dev = __in_dev_get_rcu(dev); 2204 struct flow_keys *flkeys = NULL, _flkeys; 2205 struct net *net = dev_net(dev); 2206 struct ip_tunnel_info *tun_info; 2207 int err = -EINVAL; 2208 unsigned int flags = 0; 2209 u32 itag = 0; 2210 struct rtable *rth; 2211 struct flowi4 fl4; 2212 bool do_cache = true; 2213 2214 /* IP on this device is disabled. */ 2215 2216 if (!in_dev) 2217 goto out; 2218 2219 /* Check for the most weird martians, which can be not detected 2220 * by fib_lookup. 2221 */ 2222 2223 tun_info = skb_tunnel_info(skb); 2224 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2225 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2226 else 2227 fl4.flowi4_tun_key.tun_id = 0; 2228 skb_dst_drop(skb); 2229 2230 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2231 goto martian_source; 2232 2233 res->fi = NULL; 2234 res->table = NULL; 2235 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2236 goto brd_input; 2237 2238 /* Accept zero addresses only to limited broadcast; 2239 * I even do not know to fix it or not. Waiting for complains :-) 2240 */ 2241 if (ipv4_is_zeronet(saddr)) 2242 goto martian_source; 2243 2244 if (ipv4_is_zeronet(daddr)) 2245 goto martian_destination; 2246 2247 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2248 * and call it once if daddr or/and saddr are loopback addresses 2249 */ 2250 if (ipv4_is_loopback(daddr)) { 2251 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2252 goto martian_destination; 2253 } else if (ipv4_is_loopback(saddr)) { 2254 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2255 goto martian_source; 2256 } 2257 2258 /* 2259 * Now we are ready to route packet. 2260 */ 2261 fl4.flowi4_oif = 0; 2262 fl4.flowi4_iif = dev->ifindex; 2263 fl4.flowi4_mark = skb->mark; 2264 fl4.flowi4_tos = tos; 2265 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2266 fl4.flowi4_flags = 0; 2267 fl4.daddr = daddr; 2268 fl4.saddr = saddr; 2269 fl4.flowi4_uid = sock_net_uid(net, NULL); 2270 fl4.flowi4_multipath_hash = 0; 2271 2272 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2273 flkeys = &_flkeys; 2274 } else { 2275 fl4.flowi4_proto = 0; 2276 fl4.fl4_sport = 0; 2277 fl4.fl4_dport = 0; 2278 } 2279 2280 err = fib_lookup(net, &fl4, res, 0); 2281 if (err != 0) { 2282 if (!IN_DEV_FORWARD(in_dev)) 2283 err = -EHOSTUNREACH; 2284 goto no_route; 2285 } 2286 2287 if (res->type == RTN_BROADCAST) { 2288 if (IN_DEV_BFORWARD(in_dev)) 2289 goto make_route; 2290 /* not do cache if bc_forwarding is enabled */ 2291 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2292 do_cache = false; 2293 goto brd_input; 2294 } 2295 2296 if (res->type == RTN_LOCAL) { 2297 err = fib_validate_source(skb, saddr, daddr, tos, 2298 0, dev, in_dev, &itag); 2299 if (err < 0) 2300 goto martian_source; 2301 goto local_input; 2302 } 2303 2304 if (!IN_DEV_FORWARD(in_dev)) { 2305 err = -EHOSTUNREACH; 2306 goto no_route; 2307 } 2308 if (res->type != RTN_UNICAST) 2309 goto martian_destination; 2310 2311 make_route: 2312 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2313 out: return err; 2314 2315 brd_input: 2316 if (skb->protocol != htons(ETH_P_IP)) 2317 goto e_inval; 2318 2319 if (!ipv4_is_zeronet(saddr)) { 2320 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2321 in_dev, &itag); 2322 if (err < 0) 2323 goto martian_source; 2324 } 2325 flags |= RTCF_BROADCAST; 2326 res->type = RTN_BROADCAST; 2327 RT_CACHE_STAT_INC(in_brd); 2328 2329 local_input: 2330 do_cache &= res->fi && !itag; 2331 if (do_cache) { 2332 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2333 2334 rth = rcu_dereference(nhc->nhc_rth_input); 2335 if (rt_cache_valid(rth)) { 2336 skb_dst_set_noref(skb, &rth->dst); 2337 err = 0; 2338 goto out; 2339 } 2340 } 2341 2342 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2343 flags | RTCF_LOCAL, res->type, 2344 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 2345 if (!rth) 2346 goto e_nobufs; 2347 2348 rth->dst.output= ip_rt_bug; 2349 #ifdef CONFIG_IP_ROUTE_CLASSID 2350 rth->dst.tclassid = itag; 2351 #endif 2352 rth->rt_is_input = 1; 2353 2354 RT_CACHE_STAT_INC(in_slow_tot); 2355 if (res->type == RTN_UNREACHABLE) { 2356 rth->dst.input= ip_error; 2357 rth->dst.error= -err; 2358 rth->rt_flags &= ~RTCF_LOCAL; 2359 } 2360 2361 if (do_cache) { 2362 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2363 2364 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2365 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2366 WARN_ON(rth->dst.input == lwtunnel_input); 2367 rth->dst.lwtstate->orig_input = rth->dst.input; 2368 rth->dst.input = lwtunnel_input; 2369 } 2370 2371 if (unlikely(!rt_cache_route(nhc, rth))) 2372 rt_add_uncached_list(rth); 2373 } 2374 skb_dst_set(skb, &rth->dst); 2375 err = 0; 2376 goto out; 2377 2378 no_route: 2379 RT_CACHE_STAT_INC(in_no_route); 2380 res->type = RTN_UNREACHABLE; 2381 res->fi = NULL; 2382 res->table = NULL; 2383 goto local_input; 2384 2385 /* 2386 * Do not cache martian addresses: they should be logged (RFC1812) 2387 */ 2388 martian_destination: 2389 RT_CACHE_STAT_INC(in_martian_dst); 2390 #ifdef CONFIG_IP_ROUTE_VERBOSE 2391 if (IN_DEV_LOG_MARTIANS(in_dev)) 2392 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2393 &daddr, &saddr, dev->name); 2394 #endif 2395 2396 e_inval: 2397 err = -EINVAL; 2398 goto out; 2399 2400 e_nobufs: 2401 err = -ENOBUFS; 2402 goto out; 2403 2404 martian_source: 2405 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2406 goto out; 2407 } 2408 2409 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2410 u8 tos, struct net_device *dev) 2411 { 2412 struct fib_result res; 2413 int err; 2414 2415 tos &= IPTOS_RT_MASK; 2416 rcu_read_lock(); 2417 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2418 rcu_read_unlock(); 2419 2420 return err; 2421 } 2422 EXPORT_SYMBOL(ip_route_input_noref); 2423 2424 /* called with rcu_read_lock held */ 2425 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2426 u8 tos, struct net_device *dev, struct fib_result *res) 2427 { 2428 /* Multicast recognition logic is moved from route cache to here. 2429 * The problem was that too many Ethernet cards have broken/missing 2430 * hardware multicast filters :-( As result the host on multicasting 2431 * network acquires a lot of useless route cache entries, sort of 2432 * SDR messages from all the world. Now we try to get rid of them. 2433 * Really, provided software IP multicast filter is organized 2434 * reasonably (at least, hashed), it does not result in a slowdown 2435 * comparing with route cache reject entries. 2436 * Note, that multicast routers are not affected, because 2437 * route cache entry is created eventually. 2438 */ 2439 if (ipv4_is_multicast(daddr)) { 2440 struct in_device *in_dev = __in_dev_get_rcu(dev); 2441 int our = 0; 2442 int err = -EINVAL; 2443 2444 if (!in_dev) 2445 return err; 2446 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2447 ip_hdr(skb)->protocol); 2448 2449 /* check l3 master if no match yet */ 2450 if (!our && netif_is_l3_slave(dev)) { 2451 struct in_device *l3_in_dev; 2452 2453 l3_in_dev = __in_dev_get_rcu(skb->dev); 2454 if (l3_in_dev) 2455 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2456 ip_hdr(skb)->protocol); 2457 } 2458 2459 if (our 2460 #ifdef CONFIG_IP_MROUTE 2461 || 2462 (!ipv4_is_local_multicast(daddr) && 2463 IN_DEV_MFORWARD(in_dev)) 2464 #endif 2465 ) { 2466 err = ip_route_input_mc(skb, daddr, saddr, 2467 tos, dev, our); 2468 } 2469 return err; 2470 } 2471 2472 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2473 } 2474 2475 /* called with rcu_read_lock() */ 2476 static struct rtable *__mkroute_output(const struct fib_result *res, 2477 const struct flowi4 *fl4, int orig_oif, 2478 struct net_device *dev_out, 2479 unsigned int flags) 2480 { 2481 struct fib_info *fi = res->fi; 2482 struct fib_nh_exception *fnhe; 2483 struct in_device *in_dev; 2484 u16 type = res->type; 2485 struct rtable *rth; 2486 bool do_cache; 2487 2488 in_dev = __in_dev_get_rcu(dev_out); 2489 if (!in_dev) 2490 return ERR_PTR(-EINVAL); 2491 2492 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2493 if (ipv4_is_loopback(fl4->saddr) && 2494 !(dev_out->flags & IFF_LOOPBACK) && 2495 !netif_is_l3_master(dev_out)) 2496 return ERR_PTR(-EINVAL); 2497 2498 if (ipv4_is_lbcast(fl4->daddr)) 2499 type = RTN_BROADCAST; 2500 else if (ipv4_is_multicast(fl4->daddr)) 2501 type = RTN_MULTICAST; 2502 else if (ipv4_is_zeronet(fl4->daddr)) 2503 return ERR_PTR(-EINVAL); 2504 2505 if (dev_out->flags & IFF_LOOPBACK) 2506 flags |= RTCF_LOCAL; 2507 2508 do_cache = true; 2509 if (type == RTN_BROADCAST) { 2510 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2511 fi = NULL; 2512 } else if (type == RTN_MULTICAST) { 2513 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2514 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2515 fl4->flowi4_proto)) 2516 flags &= ~RTCF_LOCAL; 2517 else 2518 do_cache = false; 2519 /* If multicast route do not exist use 2520 * default one, but do not gateway in this case. 2521 * Yes, it is hack. 2522 */ 2523 if (fi && res->prefixlen < 4) 2524 fi = NULL; 2525 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2526 (orig_oif != dev_out->ifindex)) { 2527 /* For local routes that require a particular output interface 2528 * we do not want to cache the result. Caching the result 2529 * causes incorrect behaviour when there are multiple source 2530 * addresses on the interface, the end result being that if the 2531 * intended recipient is waiting on that interface for the 2532 * packet he won't receive it because it will be delivered on 2533 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2534 * be set to the loopback interface as well. 2535 */ 2536 do_cache = false; 2537 } 2538 2539 fnhe = NULL; 2540 do_cache &= fi != NULL; 2541 if (fi) { 2542 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2543 struct rtable __rcu **prth; 2544 2545 fnhe = find_exception(nhc, fl4->daddr); 2546 if (!do_cache) 2547 goto add; 2548 if (fnhe) { 2549 prth = &fnhe->fnhe_rth_output; 2550 } else { 2551 if (unlikely(fl4->flowi4_flags & 2552 FLOWI_FLAG_KNOWN_NH && 2553 !(nhc->nhc_gw_family && 2554 nhc->nhc_scope == RT_SCOPE_LINK))) { 2555 do_cache = false; 2556 goto add; 2557 } 2558 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2559 } 2560 rth = rcu_dereference(*prth); 2561 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2562 return rth; 2563 } 2564 2565 add: 2566 rth = rt_dst_alloc(dev_out, flags, type, 2567 IN_DEV_ORCONF(in_dev, NOPOLICY), 2568 IN_DEV_ORCONF(in_dev, NOXFRM)); 2569 if (!rth) 2570 return ERR_PTR(-ENOBUFS); 2571 2572 rth->rt_iif = orig_oif; 2573 2574 RT_CACHE_STAT_INC(out_slow_tot); 2575 2576 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2577 if (flags & RTCF_LOCAL && 2578 !(dev_out->flags & IFF_LOOPBACK)) { 2579 rth->dst.output = ip_mc_output; 2580 RT_CACHE_STAT_INC(out_slow_mc); 2581 } 2582 #ifdef CONFIG_IP_MROUTE 2583 if (type == RTN_MULTICAST) { 2584 if (IN_DEV_MFORWARD(in_dev) && 2585 !ipv4_is_local_multicast(fl4->daddr)) { 2586 rth->dst.input = ip_mr_input; 2587 rth->dst.output = ip_mc_output; 2588 } 2589 } 2590 #endif 2591 } 2592 2593 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2594 lwtunnel_set_redirect(&rth->dst); 2595 2596 return rth; 2597 } 2598 2599 /* 2600 * Major route resolver routine. 2601 */ 2602 2603 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2604 const struct sk_buff *skb) 2605 { 2606 __u8 tos = RT_FL_TOS(fl4); 2607 struct fib_result res = { 2608 .type = RTN_UNSPEC, 2609 .fi = NULL, 2610 .table = NULL, 2611 .tclassid = 0, 2612 }; 2613 struct rtable *rth; 2614 2615 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2616 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2617 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2618 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2619 2620 rcu_read_lock(); 2621 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2622 rcu_read_unlock(); 2623 2624 return rth; 2625 } 2626 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2627 2628 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2629 struct fib_result *res, 2630 const struct sk_buff *skb) 2631 { 2632 struct net_device *dev_out = NULL; 2633 int orig_oif = fl4->flowi4_oif; 2634 unsigned int flags = 0; 2635 struct rtable *rth; 2636 int err; 2637 2638 if (fl4->saddr) { 2639 if (ipv4_is_multicast(fl4->saddr) || 2640 ipv4_is_lbcast(fl4->saddr) || 2641 ipv4_is_zeronet(fl4->saddr)) { 2642 rth = ERR_PTR(-EINVAL); 2643 goto out; 2644 } 2645 2646 rth = ERR_PTR(-ENETUNREACH); 2647 2648 /* I removed check for oif == dev_out->oif here. 2649 * It was wrong for two reasons: 2650 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2651 * is assigned to multiple interfaces. 2652 * 2. Moreover, we are allowed to send packets with saddr 2653 * of another iface. --ANK 2654 */ 2655 2656 if (fl4->flowi4_oif == 0 && 2657 (ipv4_is_multicast(fl4->daddr) || 2658 ipv4_is_lbcast(fl4->daddr))) { 2659 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2660 dev_out = __ip_dev_find(net, fl4->saddr, false); 2661 if (!dev_out) 2662 goto out; 2663 2664 /* Special hack: user can direct multicasts 2665 * and limited broadcast via necessary interface 2666 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2667 * This hack is not just for fun, it allows 2668 * vic,vat and friends to work. 2669 * They bind socket to loopback, set ttl to zero 2670 * and expect that it will work. 2671 * From the viewpoint of routing cache they are broken, 2672 * because we are not allowed to build multicast path 2673 * with loopback source addr (look, routing cache 2674 * cannot know, that ttl is zero, so that packet 2675 * will not leave this host and route is valid). 2676 * Luckily, this hack is good workaround. 2677 */ 2678 2679 fl4->flowi4_oif = dev_out->ifindex; 2680 goto make_route; 2681 } 2682 2683 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2684 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2685 if (!__ip_dev_find(net, fl4->saddr, false)) 2686 goto out; 2687 } 2688 } 2689 2690 2691 if (fl4->flowi4_oif) { 2692 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2693 rth = ERR_PTR(-ENODEV); 2694 if (!dev_out) 2695 goto out; 2696 2697 /* RACE: Check return value of inet_select_addr instead. */ 2698 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2699 rth = ERR_PTR(-ENETUNREACH); 2700 goto out; 2701 } 2702 if (ipv4_is_local_multicast(fl4->daddr) || 2703 ipv4_is_lbcast(fl4->daddr) || 2704 fl4->flowi4_proto == IPPROTO_IGMP) { 2705 if (!fl4->saddr) 2706 fl4->saddr = inet_select_addr(dev_out, 0, 2707 RT_SCOPE_LINK); 2708 goto make_route; 2709 } 2710 if (!fl4->saddr) { 2711 if (ipv4_is_multicast(fl4->daddr)) 2712 fl4->saddr = inet_select_addr(dev_out, 0, 2713 fl4->flowi4_scope); 2714 else if (!fl4->daddr) 2715 fl4->saddr = inet_select_addr(dev_out, 0, 2716 RT_SCOPE_HOST); 2717 } 2718 } 2719 2720 if (!fl4->daddr) { 2721 fl4->daddr = fl4->saddr; 2722 if (!fl4->daddr) 2723 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2724 dev_out = net->loopback_dev; 2725 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2726 res->type = RTN_LOCAL; 2727 flags |= RTCF_LOCAL; 2728 goto make_route; 2729 } 2730 2731 err = fib_lookup(net, fl4, res, 0); 2732 if (err) { 2733 res->fi = NULL; 2734 res->table = NULL; 2735 if (fl4->flowi4_oif && 2736 (ipv4_is_multicast(fl4->daddr) || 2737 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2738 /* Apparently, routing tables are wrong. Assume, 2739 * that the destination is on link. 2740 * 2741 * WHY? DW. 2742 * Because we are allowed to send to iface 2743 * even if it has NO routes and NO assigned 2744 * addresses. When oif is specified, routing 2745 * tables are looked up with only one purpose: 2746 * to catch if destination is gatewayed, rather than 2747 * direct. Moreover, if MSG_DONTROUTE is set, 2748 * we send packet, ignoring both routing tables 2749 * and ifaddr state. --ANK 2750 * 2751 * 2752 * We could make it even if oif is unknown, 2753 * likely IPv6, but we do not. 2754 */ 2755 2756 if (fl4->saddr == 0) 2757 fl4->saddr = inet_select_addr(dev_out, 0, 2758 RT_SCOPE_LINK); 2759 res->type = RTN_UNICAST; 2760 goto make_route; 2761 } 2762 rth = ERR_PTR(err); 2763 goto out; 2764 } 2765 2766 if (res->type == RTN_LOCAL) { 2767 if (!fl4->saddr) { 2768 if (res->fi->fib_prefsrc) 2769 fl4->saddr = res->fi->fib_prefsrc; 2770 else 2771 fl4->saddr = fl4->daddr; 2772 } 2773 2774 /* L3 master device is the loopback for that domain */ 2775 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2776 net->loopback_dev; 2777 2778 /* make sure orig_oif points to fib result device even 2779 * though packet rx/tx happens over loopback or l3mdev 2780 */ 2781 orig_oif = FIB_RES_OIF(*res); 2782 2783 fl4->flowi4_oif = dev_out->ifindex; 2784 flags |= RTCF_LOCAL; 2785 goto make_route; 2786 } 2787 2788 fib_select_path(net, res, fl4, skb); 2789 2790 dev_out = FIB_RES_DEV(*res); 2791 2792 make_route: 2793 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2794 2795 out: 2796 return rth; 2797 } 2798 2799 static struct dst_ops ipv4_dst_blackhole_ops = { 2800 .family = AF_INET, 2801 .default_advmss = ipv4_default_advmss, 2802 .neigh_lookup = ipv4_neigh_lookup, 2803 .check = dst_blackhole_check, 2804 .cow_metrics = dst_blackhole_cow_metrics, 2805 .update_pmtu = dst_blackhole_update_pmtu, 2806 .redirect = dst_blackhole_redirect, 2807 .mtu = dst_blackhole_mtu, 2808 }; 2809 2810 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2811 { 2812 struct rtable *ort = (struct rtable *) dst_orig; 2813 struct rtable *rt; 2814 2815 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2816 if (rt) { 2817 struct dst_entry *new = &rt->dst; 2818 2819 new->__use = 1; 2820 new->input = dst_discard; 2821 new->output = dst_discard_out; 2822 2823 new->dev = net->loopback_dev; 2824 dev_hold_track(new->dev, &new->dev_tracker, GFP_ATOMIC); 2825 2826 rt->rt_is_input = ort->rt_is_input; 2827 rt->rt_iif = ort->rt_iif; 2828 rt->rt_pmtu = ort->rt_pmtu; 2829 rt->rt_mtu_locked = ort->rt_mtu_locked; 2830 2831 rt->rt_genid = rt_genid_ipv4(net); 2832 rt->rt_flags = ort->rt_flags; 2833 rt->rt_type = ort->rt_type; 2834 rt->rt_uses_gateway = ort->rt_uses_gateway; 2835 rt->rt_gw_family = ort->rt_gw_family; 2836 if (rt->rt_gw_family == AF_INET) 2837 rt->rt_gw4 = ort->rt_gw4; 2838 else if (rt->rt_gw_family == AF_INET6) 2839 rt->rt_gw6 = ort->rt_gw6; 2840 2841 INIT_LIST_HEAD(&rt->rt_uncached); 2842 } 2843 2844 dst_release(dst_orig); 2845 2846 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2847 } 2848 2849 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2850 const struct sock *sk) 2851 { 2852 struct rtable *rt = __ip_route_output_key(net, flp4); 2853 2854 if (IS_ERR(rt)) 2855 return rt; 2856 2857 if (flp4->flowi4_proto) { 2858 flp4->flowi4_oif = rt->dst.dev->ifindex; 2859 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2860 flowi4_to_flowi(flp4), 2861 sk, 0); 2862 } 2863 2864 return rt; 2865 } 2866 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2867 2868 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2869 struct net_device *dev, 2870 struct net *net, __be32 *saddr, 2871 const struct ip_tunnel_info *info, 2872 u8 protocol, bool use_cache) 2873 { 2874 #ifdef CONFIG_DST_CACHE 2875 struct dst_cache *dst_cache; 2876 #endif 2877 struct rtable *rt = NULL; 2878 struct flowi4 fl4; 2879 __u8 tos; 2880 2881 #ifdef CONFIG_DST_CACHE 2882 dst_cache = (struct dst_cache *)&info->dst_cache; 2883 if (use_cache) { 2884 rt = dst_cache_get_ip4(dst_cache, saddr); 2885 if (rt) 2886 return rt; 2887 } 2888 #endif 2889 memset(&fl4, 0, sizeof(fl4)); 2890 fl4.flowi4_mark = skb->mark; 2891 fl4.flowi4_proto = protocol; 2892 fl4.daddr = info->key.u.ipv4.dst; 2893 fl4.saddr = info->key.u.ipv4.src; 2894 tos = info->key.tos; 2895 fl4.flowi4_tos = RT_TOS(tos); 2896 2897 rt = ip_route_output_key(net, &fl4); 2898 if (IS_ERR(rt)) { 2899 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2900 return ERR_PTR(-ENETUNREACH); 2901 } 2902 if (rt->dst.dev == dev) { /* is this necessary? */ 2903 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2904 ip_rt_put(rt); 2905 return ERR_PTR(-ELOOP); 2906 } 2907 #ifdef CONFIG_DST_CACHE 2908 if (use_cache) 2909 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2910 #endif 2911 *saddr = fl4.saddr; 2912 return rt; 2913 } 2914 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2915 2916 /* called with rcu_read_lock held */ 2917 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2918 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2919 struct sk_buff *skb, u32 portid, u32 seq, 2920 unsigned int flags) 2921 { 2922 struct rtmsg *r; 2923 struct nlmsghdr *nlh; 2924 unsigned long expires = 0; 2925 u32 error; 2926 u32 metrics[RTAX_MAX]; 2927 2928 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2929 if (!nlh) 2930 return -EMSGSIZE; 2931 2932 r = nlmsg_data(nlh); 2933 r->rtm_family = AF_INET; 2934 r->rtm_dst_len = 32; 2935 r->rtm_src_len = 0; 2936 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2937 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2938 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2939 goto nla_put_failure; 2940 r->rtm_type = rt->rt_type; 2941 r->rtm_scope = RT_SCOPE_UNIVERSE; 2942 r->rtm_protocol = RTPROT_UNSPEC; 2943 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2944 if (rt->rt_flags & RTCF_NOTIFY) 2945 r->rtm_flags |= RTM_F_NOTIFY; 2946 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2947 r->rtm_flags |= RTCF_DOREDIRECT; 2948 2949 if (nla_put_in_addr(skb, RTA_DST, dst)) 2950 goto nla_put_failure; 2951 if (src) { 2952 r->rtm_src_len = 32; 2953 if (nla_put_in_addr(skb, RTA_SRC, src)) 2954 goto nla_put_failure; 2955 } 2956 if (rt->dst.dev && 2957 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2958 goto nla_put_failure; 2959 if (rt->dst.lwtstate && 2960 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2961 goto nla_put_failure; 2962 #ifdef CONFIG_IP_ROUTE_CLASSID 2963 if (rt->dst.tclassid && 2964 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2965 goto nla_put_failure; 2966 #endif 2967 if (fl4 && !rt_is_input_route(rt) && 2968 fl4->saddr != src) { 2969 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2970 goto nla_put_failure; 2971 } 2972 if (rt->rt_uses_gateway) { 2973 if (rt->rt_gw_family == AF_INET && 2974 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2975 goto nla_put_failure; 2976 } else if (rt->rt_gw_family == AF_INET6) { 2977 int alen = sizeof(struct in6_addr); 2978 struct nlattr *nla; 2979 struct rtvia *via; 2980 2981 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2982 if (!nla) 2983 goto nla_put_failure; 2984 2985 via = nla_data(nla); 2986 via->rtvia_family = AF_INET6; 2987 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2988 } 2989 } 2990 2991 expires = rt->dst.expires; 2992 if (expires) { 2993 unsigned long now = jiffies; 2994 2995 if (time_before(now, expires)) 2996 expires -= now; 2997 else 2998 expires = 0; 2999 } 3000 3001 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3002 if (rt->rt_pmtu && expires) 3003 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3004 if (rt->rt_mtu_locked && expires) 3005 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3006 if (rtnetlink_put_metrics(skb, metrics) < 0) 3007 goto nla_put_failure; 3008 3009 if (fl4) { 3010 if (fl4->flowi4_mark && 3011 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3012 goto nla_put_failure; 3013 3014 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3015 nla_put_u32(skb, RTA_UID, 3016 from_kuid_munged(current_user_ns(), 3017 fl4->flowi4_uid))) 3018 goto nla_put_failure; 3019 3020 if (rt_is_input_route(rt)) { 3021 #ifdef CONFIG_IP_MROUTE 3022 if (ipv4_is_multicast(dst) && 3023 !ipv4_is_local_multicast(dst) && 3024 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3025 int err = ipmr_get_route(net, skb, 3026 fl4->saddr, fl4->daddr, 3027 r, portid); 3028 3029 if (err <= 0) { 3030 if (err == 0) 3031 return 0; 3032 goto nla_put_failure; 3033 } 3034 } else 3035 #endif 3036 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3037 goto nla_put_failure; 3038 } 3039 } 3040 3041 error = rt->dst.error; 3042 3043 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3044 goto nla_put_failure; 3045 3046 nlmsg_end(skb, nlh); 3047 return 0; 3048 3049 nla_put_failure: 3050 nlmsg_cancel(skb, nlh); 3051 return -EMSGSIZE; 3052 } 3053 3054 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3055 struct netlink_callback *cb, u32 table_id, 3056 struct fnhe_hash_bucket *bucket, int genid, 3057 int *fa_index, int fa_start, unsigned int flags) 3058 { 3059 int i; 3060 3061 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3062 struct fib_nh_exception *fnhe; 3063 3064 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3065 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3066 struct rtable *rt; 3067 int err; 3068 3069 if (*fa_index < fa_start) 3070 goto next; 3071 3072 if (fnhe->fnhe_genid != genid) 3073 goto next; 3074 3075 if (fnhe->fnhe_expires && 3076 time_after(jiffies, fnhe->fnhe_expires)) 3077 goto next; 3078 3079 rt = rcu_dereference(fnhe->fnhe_rth_input); 3080 if (!rt) 3081 rt = rcu_dereference(fnhe->fnhe_rth_output); 3082 if (!rt) 3083 goto next; 3084 3085 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3086 table_id, NULL, skb, 3087 NETLINK_CB(cb->skb).portid, 3088 cb->nlh->nlmsg_seq, flags); 3089 if (err) 3090 return err; 3091 next: 3092 (*fa_index)++; 3093 } 3094 } 3095 3096 return 0; 3097 } 3098 3099 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3100 u32 table_id, struct fib_info *fi, 3101 int *fa_index, int fa_start, unsigned int flags) 3102 { 3103 struct net *net = sock_net(cb->skb->sk); 3104 int nhsel, genid = fnhe_genid(net); 3105 3106 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3107 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3108 struct fnhe_hash_bucket *bucket; 3109 int err; 3110 3111 if (nhc->nhc_flags & RTNH_F_DEAD) 3112 continue; 3113 3114 rcu_read_lock(); 3115 bucket = rcu_dereference(nhc->nhc_exceptions); 3116 err = 0; 3117 if (bucket) 3118 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3119 genid, fa_index, fa_start, 3120 flags); 3121 rcu_read_unlock(); 3122 if (err) 3123 return err; 3124 } 3125 3126 return 0; 3127 } 3128 3129 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3130 u8 ip_proto, __be16 sport, 3131 __be16 dport) 3132 { 3133 struct sk_buff *skb; 3134 struct iphdr *iph; 3135 3136 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3137 if (!skb) 3138 return NULL; 3139 3140 /* Reserve room for dummy headers, this skb can pass 3141 * through good chunk of routing engine. 3142 */ 3143 skb_reset_mac_header(skb); 3144 skb_reset_network_header(skb); 3145 skb->protocol = htons(ETH_P_IP); 3146 iph = skb_put(skb, sizeof(struct iphdr)); 3147 iph->protocol = ip_proto; 3148 iph->saddr = src; 3149 iph->daddr = dst; 3150 iph->version = 0x4; 3151 iph->frag_off = 0; 3152 iph->ihl = 0x5; 3153 skb_set_transport_header(skb, skb->len); 3154 3155 switch (iph->protocol) { 3156 case IPPROTO_UDP: { 3157 struct udphdr *udph; 3158 3159 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3160 udph->source = sport; 3161 udph->dest = dport; 3162 udph->len = htons(sizeof(struct udphdr)); 3163 udph->check = 0; 3164 break; 3165 } 3166 case IPPROTO_TCP: { 3167 struct tcphdr *tcph; 3168 3169 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3170 tcph->source = sport; 3171 tcph->dest = dport; 3172 tcph->doff = sizeof(struct tcphdr) / 4; 3173 tcph->rst = 1; 3174 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3175 src, dst, 0); 3176 break; 3177 } 3178 case IPPROTO_ICMP: { 3179 struct icmphdr *icmph; 3180 3181 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3182 icmph->type = ICMP_ECHO; 3183 icmph->code = 0; 3184 } 3185 } 3186 3187 return skb; 3188 } 3189 3190 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3191 const struct nlmsghdr *nlh, 3192 struct nlattr **tb, 3193 struct netlink_ext_ack *extack) 3194 { 3195 struct rtmsg *rtm; 3196 int i, err; 3197 3198 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3199 NL_SET_ERR_MSG(extack, 3200 "ipv4: Invalid header for route get request"); 3201 return -EINVAL; 3202 } 3203 3204 if (!netlink_strict_get_check(skb)) 3205 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3206 rtm_ipv4_policy, extack); 3207 3208 rtm = nlmsg_data(nlh); 3209 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3210 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3211 rtm->rtm_table || rtm->rtm_protocol || 3212 rtm->rtm_scope || rtm->rtm_type) { 3213 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3214 return -EINVAL; 3215 } 3216 3217 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3218 RTM_F_LOOKUP_TABLE | 3219 RTM_F_FIB_MATCH)) { 3220 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3221 return -EINVAL; 3222 } 3223 3224 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3225 rtm_ipv4_policy, extack); 3226 if (err) 3227 return err; 3228 3229 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3230 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3231 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3232 return -EINVAL; 3233 } 3234 3235 for (i = 0; i <= RTA_MAX; i++) { 3236 if (!tb[i]) 3237 continue; 3238 3239 switch (i) { 3240 case RTA_IIF: 3241 case RTA_OIF: 3242 case RTA_SRC: 3243 case RTA_DST: 3244 case RTA_IP_PROTO: 3245 case RTA_SPORT: 3246 case RTA_DPORT: 3247 case RTA_MARK: 3248 case RTA_UID: 3249 break; 3250 default: 3251 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3252 return -EINVAL; 3253 } 3254 } 3255 3256 return 0; 3257 } 3258 3259 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3260 struct netlink_ext_ack *extack) 3261 { 3262 struct net *net = sock_net(in_skb->sk); 3263 struct nlattr *tb[RTA_MAX+1]; 3264 u32 table_id = RT_TABLE_MAIN; 3265 __be16 sport = 0, dport = 0; 3266 struct fib_result res = {}; 3267 u8 ip_proto = IPPROTO_UDP; 3268 struct rtable *rt = NULL; 3269 struct sk_buff *skb; 3270 struct rtmsg *rtm; 3271 struct flowi4 fl4 = {}; 3272 __be32 dst = 0; 3273 __be32 src = 0; 3274 kuid_t uid; 3275 u32 iif; 3276 int err; 3277 int mark; 3278 3279 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3280 if (err < 0) 3281 return err; 3282 3283 rtm = nlmsg_data(nlh); 3284 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3285 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3286 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3287 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3288 if (tb[RTA_UID]) 3289 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3290 else 3291 uid = (iif ? INVALID_UID : current_uid()); 3292 3293 if (tb[RTA_IP_PROTO]) { 3294 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3295 &ip_proto, AF_INET, extack); 3296 if (err) 3297 return err; 3298 } 3299 3300 if (tb[RTA_SPORT]) 3301 sport = nla_get_be16(tb[RTA_SPORT]); 3302 3303 if (tb[RTA_DPORT]) 3304 dport = nla_get_be16(tb[RTA_DPORT]); 3305 3306 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3307 if (!skb) 3308 return -ENOBUFS; 3309 3310 fl4.daddr = dst; 3311 fl4.saddr = src; 3312 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3313 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3314 fl4.flowi4_mark = mark; 3315 fl4.flowi4_uid = uid; 3316 if (sport) 3317 fl4.fl4_sport = sport; 3318 if (dport) 3319 fl4.fl4_dport = dport; 3320 fl4.flowi4_proto = ip_proto; 3321 3322 rcu_read_lock(); 3323 3324 if (iif) { 3325 struct net_device *dev; 3326 3327 dev = dev_get_by_index_rcu(net, iif); 3328 if (!dev) { 3329 err = -ENODEV; 3330 goto errout_rcu; 3331 } 3332 3333 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3334 skb->dev = dev; 3335 skb->mark = mark; 3336 err = ip_route_input_rcu(skb, dst, src, 3337 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3338 &res); 3339 3340 rt = skb_rtable(skb); 3341 if (err == 0 && rt->dst.error) 3342 err = -rt->dst.error; 3343 } else { 3344 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3345 skb->dev = net->loopback_dev; 3346 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3347 err = 0; 3348 if (IS_ERR(rt)) 3349 err = PTR_ERR(rt); 3350 else 3351 skb_dst_set(skb, &rt->dst); 3352 } 3353 3354 if (err) 3355 goto errout_rcu; 3356 3357 if (rtm->rtm_flags & RTM_F_NOTIFY) 3358 rt->rt_flags |= RTCF_NOTIFY; 3359 3360 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3361 table_id = res.table ? res.table->tb_id : 0; 3362 3363 /* reset skb for netlink reply msg */ 3364 skb_trim(skb, 0); 3365 skb_reset_network_header(skb); 3366 skb_reset_transport_header(skb); 3367 skb_reset_mac_header(skb); 3368 3369 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3370 struct fib_rt_info fri; 3371 3372 if (!res.fi) { 3373 err = fib_props[res.type].error; 3374 if (!err) 3375 err = -EHOSTUNREACH; 3376 goto errout_rcu; 3377 } 3378 fri.fi = res.fi; 3379 fri.tb_id = table_id; 3380 fri.dst = res.prefix; 3381 fri.dst_len = res.prefixlen; 3382 fri.tos = fl4.flowi4_tos; 3383 fri.type = rt->rt_type; 3384 fri.offload = 0; 3385 fri.trap = 0; 3386 fri.offload_failed = 0; 3387 if (res.fa_head) { 3388 struct fib_alias *fa; 3389 3390 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3391 u8 slen = 32 - fri.dst_len; 3392 3393 if (fa->fa_slen == slen && 3394 fa->tb_id == fri.tb_id && 3395 fa->fa_tos == fri.tos && 3396 fa->fa_info == res.fi && 3397 fa->fa_type == fri.type) { 3398 fri.offload = READ_ONCE(fa->offload); 3399 fri.trap = READ_ONCE(fa->trap); 3400 break; 3401 } 3402 } 3403 } 3404 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3405 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3406 } else { 3407 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3408 NETLINK_CB(in_skb).portid, 3409 nlh->nlmsg_seq, 0); 3410 } 3411 if (err < 0) 3412 goto errout_rcu; 3413 3414 rcu_read_unlock(); 3415 3416 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3417 3418 errout_free: 3419 return err; 3420 errout_rcu: 3421 rcu_read_unlock(); 3422 kfree_skb(skb); 3423 goto errout_free; 3424 } 3425 3426 void ip_rt_multicast_event(struct in_device *in_dev) 3427 { 3428 rt_cache_flush(dev_net(in_dev->dev)); 3429 } 3430 3431 #ifdef CONFIG_SYSCTL 3432 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3433 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3434 static int ip_rt_gc_elasticity __read_mostly = 8; 3435 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3436 3437 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3438 void *buffer, size_t *lenp, loff_t *ppos) 3439 { 3440 struct net *net = (struct net *)__ctl->extra1; 3441 3442 if (write) { 3443 rt_cache_flush(net); 3444 fnhe_genid_bump(net); 3445 return 0; 3446 } 3447 3448 return -EINVAL; 3449 } 3450 3451 static struct ctl_table ipv4_route_table[] = { 3452 { 3453 .procname = "gc_thresh", 3454 .data = &ipv4_dst_ops.gc_thresh, 3455 .maxlen = sizeof(int), 3456 .mode = 0644, 3457 .proc_handler = proc_dointvec, 3458 }, 3459 { 3460 .procname = "max_size", 3461 .data = &ip_rt_max_size, 3462 .maxlen = sizeof(int), 3463 .mode = 0644, 3464 .proc_handler = proc_dointvec, 3465 }, 3466 { 3467 /* Deprecated. Use gc_min_interval_ms */ 3468 3469 .procname = "gc_min_interval", 3470 .data = &ip_rt_gc_min_interval, 3471 .maxlen = sizeof(int), 3472 .mode = 0644, 3473 .proc_handler = proc_dointvec_jiffies, 3474 }, 3475 { 3476 .procname = "gc_min_interval_ms", 3477 .data = &ip_rt_gc_min_interval, 3478 .maxlen = sizeof(int), 3479 .mode = 0644, 3480 .proc_handler = proc_dointvec_ms_jiffies, 3481 }, 3482 { 3483 .procname = "gc_timeout", 3484 .data = &ip_rt_gc_timeout, 3485 .maxlen = sizeof(int), 3486 .mode = 0644, 3487 .proc_handler = proc_dointvec_jiffies, 3488 }, 3489 { 3490 .procname = "gc_interval", 3491 .data = &ip_rt_gc_interval, 3492 .maxlen = sizeof(int), 3493 .mode = 0644, 3494 .proc_handler = proc_dointvec_jiffies, 3495 }, 3496 { 3497 .procname = "redirect_load", 3498 .data = &ip_rt_redirect_load, 3499 .maxlen = sizeof(int), 3500 .mode = 0644, 3501 .proc_handler = proc_dointvec, 3502 }, 3503 { 3504 .procname = "redirect_number", 3505 .data = &ip_rt_redirect_number, 3506 .maxlen = sizeof(int), 3507 .mode = 0644, 3508 .proc_handler = proc_dointvec, 3509 }, 3510 { 3511 .procname = "redirect_silence", 3512 .data = &ip_rt_redirect_silence, 3513 .maxlen = sizeof(int), 3514 .mode = 0644, 3515 .proc_handler = proc_dointvec, 3516 }, 3517 { 3518 .procname = "error_cost", 3519 .data = &ip_rt_error_cost, 3520 .maxlen = sizeof(int), 3521 .mode = 0644, 3522 .proc_handler = proc_dointvec, 3523 }, 3524 { 3525 .procname = "error_burst", 3526 .data = &ip_rt_error_burst, 3527 .maxlen = sizeof(int), 3528 .mode = 0644, 3529 .proc_handler = proc_dointvec, 3530 }, 3531 { 3532 .procname = "gc_elasticity", 3533 .data = &ip_rt_gc_elasticity, 3534 .maxlen = sizeof(int), 3535 .mode = 0644, 3536 .proc_handler = proc_dointvec, 3537 }, 3538 { 3539 .procname = "min_adv_mss", 3540 .data = &ip_rt_min_advmss, 3541 .maxlen = sizeof(int), 3542 .mode = 0644, 3543 .proc_handler = proc_dointvec, 3544 }, 3545 { } 3546 }; 3547 3548 static const char ipv4_route_flush_procname[] = "flush"; 3549 3550 static struct ctl_table ipv4_route_netns_table[] = { 3551 { 3552 .procname = ipv4_route_flush_procname, 3553 .maxlen = sizeof(int), 3554 .mode = 0200, 3555 .proc_handler = ipv4_sysctl_rtcache_flush, 3556 }, 3557 { 3558 .procname = "min_pmtu", 3559 .data = &init_net.ipv4.ip_rt_min_pmtu, 3560 .maxlen = sizeof(int), 3561 .mode = 0644, 3562 .proc_handler = proc_dointvec_minmax, 3563 .extra1 = &ip_min_valid_pmtu, 3564 }, 3565 { 3566 .procname = "mtu_expires", 3567 .data = &init_net.ipv4.ip_rt_mtu_expires, 3568 .maxlen = sizeof(int), 3569 .mode = 0644, 3570 .proc_handler = proc_dointvec_jiffies, 3571 }, 3572 { }, 3573 }; 3574 3575 static __net_init int sysctl_route_net_init(struct net *net) 3576 { 3577 struct ctl_table *tbl; 3578 3579 tbl = ipv4_route_netns_table; 3580 if (!net_eq(net, &init_net)) { 3581 int i; 3582 3583 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3584 if (!tbl) 3585 goto err_dup; 3586 3587 /* Don't export non-whitelisted sysctls to unprivileged users */ 3588 if (net->user_ns != &init_user_ns) { 3589 if (tbl[0].procname != ipv4_route_flush_procname) 3590 tbl[0].procname = NULL; 3591 } 3592 3593 /* Update the variables to point into the current struct net 3594 * except for the first element flush 3595 */ 3596 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3597 tbl[i].data += (void *)net - (void *)&init_net; 3598 } 3599 tbl[0].extra1 = net; 3600 3601 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3602 if (!net->ipv4.route_hdr) 3603 goto err_reg; 3604 return 0; 3605 3606 err_reg: 3607 if (tbl != ipv4_route_netns_table) 3608 kfree(tbl); 3609 err_dup: 3610 return -ENOMEM; 3611 } 3612 3613 static __net_exit void sysctl_route_net_exit(struct net *net) 3614 { 3615 struct ctl_table *tbl; 3616 3617 tbl = net->ipv4.route_hdr->ctl_table_arg; 3618 unregister_net_sysctl_table(net->ipv4.route_hdr); 3619 BUG_ON(tbl == ipv4_route_netns_table); 3620 kfree(tbl); 3621 } 3622 3623 static __net_initdata struct pernet_operations sysctl_route_ops = { 3624 .init = sysctl_route_net_init, 3625 .exit = sysctl_route_net_exit, 3626 }; 3627 #endif 3628 3629 static __net_init int netns_ip_rt_init(struct net *net) 3630 { 3631 /* Set default value for namespaceified sysctls */ 3632 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3633 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3634 return 0; 3635 } 3636 3637 static struct pernet_operations __net_initdata ip_rt_ops = { 3638 .init = netns_ip_rt_init, 3639 }; 3640 3641 static __net_init int rt_genid_init(struct net *net) 3642 { 3643 atomic_set(&net->ipv4.rt_genid, 0); 3644 atomic_set(&net->fnhe_genid, 0); 3645 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3646 return 0; 3647 } 3648 3649 static __net_initdata struct pernet_operations rt_genid_ops = { 3650 .init = rt_genid_init, 3651 }; 3652 3653 static int __net_init ipv4_inetpeer_init(struct net *net) 3654 { 3655 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3656 3657 if (!bp) 3658 return -ENOMEM; 3659 inet_peer_base_init(bp); 3660 net->ipv4.peers = bp; 3661 return 0; 3662 } 3663 3664 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3665 { 3666 struct inet_peer_base *bp = net->ipv4.peers; 3667 3668 net->ipv4.peers = NULL; 3669 inetpeer_invalidate_tree(bp); 3670 kfree(bp); 3671 } 3672 3673 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3674 .init = ipv4_inetpeer_init, 3675 .exit = ipv4_inetpeer_exit, 3676 }; 3677 3678 #ifdef CONFIG_IP_ROUTE_CLASSID 3679 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3680 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3681 3682 int __init ip_rt_init(void) 3683 { 3684 void *idents_hash; 3685 int cpu; 3686 3687 /* For modern hosts, this will use 2 MB of memory */ 3688 idents_hash = alloc_large_system_hash("IP idents", 3689 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3690 0, 3691 16, /* one bucket per 64 KB */ 3692 HASH_ZERO, 3693 NULL, 3694 &ip_idents_mask, 3695 2048, 3696 256*1024); 3697 3698 ip_idents = idents_hash; 3699 3700 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3701 3702 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3703 3704 for_each_possible_cpu(cpu) { 3705 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3706 3707 INIT_LIST_HEAD(&ul->head); 3708 spin_lock_init(&ul->lock); 3709 } 3710 #ifdef CONFIG_IP_ROUTE_CLASSID 3711 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3712 if (!ip_rt_acct) 3713 panic("IP: failed to allocate ip_rt_acct\n"); 3714 #endif 3715 3716 ipv4_dst_ops.kmem_cachep = 3717 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3718 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3719 3720 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3721 3722 if (dst_entries_init(&ipv4_dst_ops) < 0) 3723 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3724 3725 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3726 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3727 3728 ipv4_dst_ops.gc_thresh = ~0; 3729 ip_rt_max_size = INT_MAX; 3730 3731 devinet_init(); 3732 ip_fib_init(); 3733 3734 if (ip_rt_proc_init()) 3735 pr_err("Unable to create route proc files\n"); 3736 #ifdef CONFIG_XFRM 3737 xfrm_init(); 3738 xfrm4_init(); 3739 #endif 3740 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3741 RTNL_FLAG_DOIT_UNLOCKED); 3742 3743 #ifdef CONFIG_SYSCTL 3744 register_pernet_subsys(&sysctl_route_ops); 3745 #endif 3746 register_pernet_subsys(&ip_rt_ops); 3747 register_pernet_subsys(&rt_genid_ops); 3748 register_pernet_subsys(&ipv4_inetpeer_ops); 3749 return 0; 3750 } 3751 3752 #ifdef CONFIG_SYSCTL 3753 /* 3754 * We really need to sanitize the damn ipv4 init order, then all 3755 * this nonsense will go away. 3756 */ 3757 void __init ip_static_sysctl_init(void) 3758 { 3759 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3760 } 3761 #endif 3762