1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_FL_TOS(oldflp4) \ 110 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 111 112 #define RT_GC_TIMEOUT (300*HZ) 113 114 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 115 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 116 #define DEFAULT_MIN_ADVMSS 256 117 static int ip_rt_max_size; 118 static int ip_rt_redirect_number __read_mostly = 9; 119 static int ip_rt_redirect_load __read_mostly = HZ / 50; 120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 121 static int ip_rt_error_cost __read_mostly = HZ; 122 static int ip_rt_error_burst __read_mostly = 5 * HZ; 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 static 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 } 482 483 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 484 { 485 u32 hash, id; 486 487 /* Note the following code is not safe, but this is okay. */ 488 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 489 get_random_bytes(&net->ipv4.ip_id_key, 490 sizeof(net->ipv4.ip_id_key)); 491 492 hash = siphash_3u32((__force u32)iph->daddr, 493 (__force u32)iph->saddr, 494 iph->protocol, 495 &net->ipv4.ip_id_key); 496 id = ip_idents_reserve(hash, segs); 497 iph->id = htons(id); 498 } 499 EXPORT_SYMBOL(__ip_select_ident); 500 501 static void ip_rt_fix_tos(struct flowi4 *fl4) 502 { 503 __u8 tos = RT_FL_TOS(fl4); 504 505 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 506 fl4->flowi4_scope = tos & RTO_ONLINK ? 507 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE; 508 } 509 510 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 511 const struct sock *sk, 512 const struct iphdr *iph, 513 int oif, u8 tos, 514 u8 prot, u32 mark, int flow_flags) 515 { 516 if (sk) { 517 const struct inet_sock *inet = inet_sk(sk); 518 519 oif = sk->sk_bound_dev_if; 520 mark = sk->sk_mark; 521 tos = RT_CONN_FLAGS(sk); 522 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 523 } 524 flowi4_init_output(fl4, oif, mark, tos, 525 RT_SCOPE_UNIVERSE, prot, 526 flow_flags, 527 iph->daddr, iph->saddr, 0, 0, 528 sock_net_uid(net, sk)); 529 } 530 531 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 532 const struct sock *sk) 533 { 534 const struct net *net = dev_net(skb->dev); 535 const struct iphdr *iph = ip_hdr(skb); 536 int oif = skb->dev->ifindex; 537 u8 tos = RT_TOS(iph->tos); 538 u8 prot = iph->protocol; 539 u32 mark = skb->mark; 540 541 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 542 } 543 544 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 545 { 546 const struct inet_sock *inet = inet_sk(sk); 547 const struct ip_options_rcu *inet_opt; 548 __be32 daddr = inet->inet_daddr; 549 550 rcu_read_lock(); 551 inet_opt = rcu_dereference(inet->inet_opt); 552 if (inet_opt && inet_opt->opt.srr) 553 daddr = inet_opt->opt.faddr; 554 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 555 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 556 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 557 inet_sk_flowi_flags(sk), 558 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 559 rcu_read_unlock(); 560 } 561 562 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 563 const struct sk_buff *skb) 564 { 565 if (skb) 566 build_skb_flow_key(fl4, skb, sk); 567 else 568 build_sk_flow_key(fl4, sk); 569 } 570 571 static DEFINE_SPINLOCK(fnhe_lock); 572 573 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 574 { 575 struct rtable *rt; 576 577 rt = rcu_dereference(fnhe->fnhe_rth_input); 578 if (rt) { 579 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 580 dst_dev_put(&rt->dst); 581 dst_release(&rt->dst); 582 } 583 rt = rcu_dereference(fnhe->fnhe_rth_output); 584 if (rt) { 585 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 586 dst_dev_put(&rt->dst); 587 dst_release(&rt->dst); 588 } 589 } 590 591 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 592 { 593 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 594 struct fib_nh_exception *fnhe, *oldest = NULL; 595 596 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 597 fnhe = rcu_dereference_protected(*fnhe_p, 598 lockdep_is_held(&fnhe_lock)); 599 if (!fnhe) 600 break; 601 if (!oldest || 602 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 603 oldest = fnhe; 604 oldest_p = fnhe_p; 605 } 606 } 607 fnhe_flush_routes(oldest); 608 *oldest_p = oldest->fnhe_next; 609 kfree_rcu(oldest, rcu); 610 } 611 612 static u32 fnhe_hashfun(__be32 daddr) 613 { 614 static siphash_aligned_key_t fnhe_hash_key; 615 u64 hval; 616 617 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 618 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 619 return hash_64(hval, FNHE_HASH_SHIFT); 620 } 621 622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 623 { 624 rt->rt_pmtu = fnhe->fnhe_pmtu; 625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 626 rt->dst.expires = fnhe->fnhe_expires; 627 628 if (fnhe->fnhe_gw) { 629 rt->rt_flags |= RTCF_REDIRECTED; 630 rt->rt_uses_gateway = 1; 631 rt->rt_gw_family = AF_INET; 632 rt->rt_gw4 = fnhe->fnhe_gw; 633 } 634 } 635 636 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 637 __be32 gw, u32 pmtu, bool lock, 638 unsigned long expires) 639 { 640 struct fnhe_hash_bucket *hash; 641 struct fib_nh_exception *fnhe; 642 struct rtable *rt; 643 u32 genid, hval; 644 unsigned int i; 645 int depth; 646 647 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 648 hval = fnhe_hashfun(daddr); 649 650 spin_lock_bh(&fnhe_lock); 651 652 hash = rcu_dereference(nhc->nhc_exceptions); 653 if (!hash) { 654 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 655 if (!hash) 656 goto out_unlock; 657 rcu_assign_pointer(nhc->nhc_exceptions, hash); 658 } 659 660 hash += hval; 661 662 depth = 0; 663 for (fnhe = rcu_dereference(hash->chain); fnhe; 664 fnhe = rcu_dereference(fnhe->fnhe_next)) { 665 if (fnhe->fnhe_daddr == daddr) 666 break; 667 depth++; 668 } 669 670 if (fnhe) { 671 if (fnhe->fnhe_genid != genid) 672 fnhe->fnhe_genid = genid; 673 if (gw) 674 fnhe->fnhe_gw = gw; 675 if (pmtu) { 676 fnhe->fnhe_pmtu = pmtu; 677 fnhe->fnhe_mtu_locked = lock; 678 } 679 fnhe->fnhe_expires = max(1UL, expires); 680 /* Update all cached dsts too */ 681 rt = rcu_dereference(fnhe->fnhe_rth_input); 682 if (rt) 683 fill_route_from_fnhe(rt, fnhe); 684 rt = rcu_dereference(fnhe->fnhe_rth_output); 685 if (rt) 686 fill_route_from_fnhe(rt, fnhe); 687 } else { 688 /* Randomize max depth to avoid some side channels attacks. */ 689 int max_depth = FNHE_RECLAIM_DEPTH + 690 prandom_u32_max(FNHE_RECLAIM_DEPTH); 691 692 while (depth > max_depth) { 693 fnhe_remove_oldest(hash); 694 depth--; 695 } 696 697 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 698 if (!fnhe) 699 goto out_unlock; 700 701 fnhe->fnhe_next = hash->chain; 702 703 fnhe->fnhe_genid = genid; 704 fnhe->fnhe_daddr = daddr; 705 fnhe->fnhe_gw = gw; 706 fnhe->fnhe_pmtu = pmtu; 707 fnhe->fnhe_mtu_locked = lock; 708 fnhe->fnhe_expires = max(1UL, expires); 709 710 rcu_assign_pointer(hash->chain, fnhe); 711 712 /* Exception created; mark the cached routes for the nexthop 713 * stale, so anyone caching it rechecks if this exception 714 * applies to them. 715 */ 716 rt = rcu_dereference(nhc->nhc_rth_input); 717 if (rt) 718 rt->dst.obsolete = DST_OBSOLETE_KILL; 719 720 for_each_possible_cpu(i) { 721 struct rtable __rcu **prt; 722 723 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 724 rt = rcu_dereference(*prt); 725 if (rt) 726 rt->dst.obsolete = DST_OBSOLETE_KILL; 727 } 728 } 729 730 fnhe->fnhe_stamp = jiffies; 731 732 out_unlock: 733 spin_unlock_bh(&fnhe_lock); 734 } 735 736 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 737 bool kill_route) 738 { 739 __be32 new_gw = icmp_hdr(skb)->un.gateway; 740 __be32 old_gw = ip_hdr(skb)->saddr; 741 struct net_device *dev = skb->dev; 742 struct in_device *in_dev; 743 struct fib_result res; 744 struct neighbour *n; 745 struct net *net; 746 747 switch (icmp_hdr(skb)->code & 7) { 748 case ICMP_REDIR_NET: 749 case ICMP_REDIR_NETTOS: 750 case ICMP_REDIR_HOST: 751 case ICMP_REDIR_HOSTTOS: 752 break; 753 754 default: 755 return; 756 } 757 758 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 759 return; 760 761 in_dev = __in_dev_get_rcu(dev); 762 if (!in_dev) 763 return; 764 765 net = dev_net(dev); 766 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 767 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 768 ipv4_is_zeronet(new_gw)) 769 goto reject_redirect; 770 771 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 772 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 773 goto reject_redirect; 774 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 775 goto reject_redirect; 776 } else { 777 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 778 goto reject_redirect; 779 } 780 781 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 782 if (!n) 783 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 784 if (!IS_ERR(n)) { 785 if (!(n->nud_state & NUD_VALID)) { 786 neigh_event_send(n, NULL); 787 } else { 788 if (fib_lookup(net, fl4, &res, 0) == 0) { 789 struct fib_nh_common *nhc; 790 791 fib_select_path(net, &res, fl4, skb); 792 nhc = FIB_RES_NHC(res); 793 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 794 0, false, 795 jiffies + ip_rt_gc_timeout); 796 } 797 if (kill_route) 798 rt->dst.obsolete = DST_OBSOLETE_KILL; 799 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 800 } 801 neigh_release(n); 802 } 803 return; 804 805 reject_redirect: 806 #ifdef CONFIG_IP_ROUTE_VERBOSE 807 if (IN_DEV_LOG_MARTIANS(in_dev)) { 808 const struct iphdr *iph = (const struct iphdr *) skb->data; 809 __be32 daddr = iph->daddr; 810 __be32 saddr = iph->saddr; 811 812 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 813 " Advised path = %pI4 -> %pI4\n", 814 &old_gw, dev->name, &new_gw, 815 &saddr, &daddr); 816 } 817 #endif 818 ; 819 } 820 821 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 822 { 823 struct rtable *rt; 824 struct flowi4 fl4; 825 const struct iphdr *iph = (const struct iphdr *) skb->data; 826 struct net *net = dev_net(skb->dev); 827 int oif = skb->dev->ifindex; 828 u8 tos = RT_TOS(iph->tos); 829 u8 prot = iph->protocol; 830 u32 mark = skb->mark; 831 832 rt = (struct rtable *) dst; 833 834 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 835 ip_rt_fix_tos(&fl4); 836 __ip_do_redirect(rt, skb, &fl4, true); 837 } 838 839 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 840 { 841 struct rtable *rt = (struct rtable *)dst; 842 struct dst_entry *ret = dst; 843 844 if (rt) { 845 if (dst->obsolete > 0) { 846 ip_rt_put(rt); 847 ret = NULL; 848 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 849 rt->dst.expires) { 850 ip_rt_put(rt); 851 ret = NULL; 852 } 853 } 854 return ret; 855 } 856 857 /* 858 * Algorithm: 859 * 1. The first ip_rt_redirect_number redirects are sent 860 * with exponential backoff, then we stop sending them at all, 861 * assuming that the host ignores our redirects. 862 * 2. If we did not see packets requiring redirects 863 * during ip_rt_redirect_silence, we assume that the host 864 * forgot redirected route and start to send redirects again. 865 * 866 * This algorithm is much cheaper and more intelligent than dumb load limiting 867 * in icmp.c. 868 * 869 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 870 * and "frag. need" (breaks PMTU discovery) in icmp.c. 871 */ 872 873 void ip_rt_send_redirect(struct sk_buff *skb) 874 { 875 struct rtable *rt = skb_rtable(skb); 876 struct in_device *in_dev; 877 struct inet_peer *peer; 878 struct net *net; 879 int log_martians; 880 int vif; 881 882 rcu_read_lock(); 883 in_dev = __in_dev_get_rcu(rt->dst.dev); 884 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 885 rcu_read_unlock(); 886 return; 887 } 888 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 889 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 890 rcu_read_unlock(); 891 892 net = dev_net(rt->dst.dev); 893 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 894 if (!peer) { 895 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 896 rt_nexthop(rt, ip_hdr(skb)->daddr)); 897 return; 898 } 899 900 /* No redirected packets during ip_rt_redirect_silence; 901 * reset the algorithm. 902 */ 903 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 904 peer->rate_tokens = 0; 905 peer->n_redirects = 0; 906 } 907 908 /* Too many ignored redirects; do not send anything 909 * set dst.rate_last to the last seen redirected packet. 910 */ 911 if (peer->n_redirects >= ip_rt_redirect_number) { 912 peer->rate_last = jiffies; 913 goto out_put_peer; 914 } 915 916 /* Check for load limit; set rate_last to the latest sent 917 * redirect. 918 */ 919 if (peer->n_redirects == 0 || 920 time_after(jiffies, 921 (peer->rate_last + 922 (ip_rt_redirect_load << peer->n_redirects)))) { 923 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 924 925 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 926 peer->rate_last = jiffies; 927 ++peer->n_redirects; 928 #ifdef CONFIG_IP_ROUTE_VERBOSE 929 if (log_martians && 930 peer->n_redirects == ip_rt_redirect_number) 931 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 932 &ip_hdr(skb)->saddr, inet_iif(skb), 933 &ip_hdr(skb)->daddr, &gw); 934 #endif 935 } 936 out_put_peer: 937 inet_putpeer(peer); 938 } 939 940 static int ip_error(struct sk_buff *skb) 941 { 942 struct rtable *rt = skb_rtable(skb); 943 struct net_device *dev = skb->dev; 944 struct in_device *in_dev; 945 struct inet_peer *peer; 946 unsigned long now; 947 struct net *net; 948 SKB_DR(reason); 949 bool send; 950 int code; 951 952 if (netif_is_l3_master(skb->dev)) { 953 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 954 if (!dev) 955 goto out; 956 } 957 958 in_dev = __in_dev_get_rcu(dev); 959 960 /* IP on this device is disabled. */ 961 if (!in_dev) 962 goto out; 963 964 net = dev_net(rt->dst.dev); 965 if (!IN_DEV_FORWARD(in_dev)) { 966 switch (rt->dst.error) { 967 case EHOSTUNREACH: 968 SKB_DR_SET(reason, IP_INADDRERRORS); 969 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 970 break; 971 972 case ENETUNREACH: 973 SKB_DR_SET(reason, IP_INNOROUTES); 974 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 975 break; 976 } 977 goto out; 978 } 979 980 switch (rt->dst.error) { 981 case EINVAL: 982 default: 983 goto out; 984 case EHOSTUNREACH: 985 code = ICMP_HOST_UNREACH; 986 break; 987 case ENETUNREACH: 988 code = ICMP_NET_UNREACH; 989 SKB_DR_SET(reason, IP_INNOROUTES); 990 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 991 break; 992 case EACCES: 993 code = ICMP_PKT_FILTERED; 994 break; 995 } 996 997 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 998 l3mdev_master_ifindex(skb->dev), 1); 999 1000 send = true; 1001 if (peer) { 1002 now = jiffies; 1003 peer->rate_tokens += now - peer->rate_last; 1004 if (peer->rate_tokens > ip_rt_error_burst) 1005 peer->rate_tokens = ip_rt_error_burst; 1006 peer->rate_last = now; 1007 if (peer->rate_tokens >= ip_rt_error_cost) 1008 peer->rate_tokens -= ip_rt_error_cost; 1009 else 1010 send = false; 1011 inet_putpeer(peer); 1012 } 1013 if (send) 1014 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1015 1016 out: kfree_skb_reason(skb, reason); 1017 return 0; 1018 } 1019 1020 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1021 { 1022 struct dst_entry *dst = &rt->dst; 1023 struct net *net = dev_net(dst->dev); 1024 struct fib_result res; 1025 bool lock = false; 1026 u32 old_mtu; 1027 1028 if (ip_mtu_locked(dst)) 1029 return; 1030 1031 old_mtu = ipv4_mtu(dst); 1032 if (old_mtu < mtu) 1033 return; 1034 1035 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1036 lock = true; 1037 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1038 } 1039 1040 if (rt->rt_pmtu == mtu && !lock && 1041 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1042 return; 1043 1044 rcu_read_lock(); 1045 if (fib_lookup(net, fl4, &res, 0) == 0) { 1046 struct fib_nh_common *nhc; 1047 1048 fib_select_path(net, &res, fl4, NULL); 1049 nhc = FIB_RES_NHC(res); 1050 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1051 jiffies + net->ipv4.ip_rt_mtu_expires); 1052 } 1053 rcu_read_unlock(); 1054 } 1055 1056 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1057 struct sk_buff *skb, u32 mtu, 1058 bool confirm_neigh) 1059 { 1060 struct rtable *rt = (struct rtable *) dst; 1061 struct flowi4 fl4; 1062 1063 ip_rt_build_flow_key(&fl4, sk, skb); 1064 ip_rt_fix_tos(&fl4); 1065 1066 /* Don't make lookup fail for bridged encapsulations */ 1067 if (skb && netif_is_any_bridge_port(skb->dev)) 1068 fl4.flowi4_oif = 0; 1069 1070 __ip_rt_update_pmtu(rt, &fl4, mtu); 1071 } 1072 1073 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1074 int oif, u8 protocol) 1075 { 1076 const struct iphdr *iph = (const struct iphdr *)skb->data; 1077 struct flowi4 fl4; 1078 struct rtable *rt; 1079 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1080 1081 __build_flow_key(net, &fl4, NULL, iph, oif, 1082 RT_TOS(iph->tos), protocol, mark, 0); 1083 rt = __ip_route_output_key(net, &fl4); 1084 if (!IS_ERR(rt)) { 1085 __ip_rt_update_pmtu(rt, &fl4, mtu); 1086 ip_rt_put(rt); 1087 } 1088 } 1089 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1090 1091 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1092 { 1093 const struct iphdr *iph = (const struct iphdr *)skb->data; 1094 struct flowi4 fl4; 1095 struct rtable *rt; 1096 1097 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1098 1099 if (!fl4.flowi4_mark) 1100 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1101 1102 rt = __ip_route_output_key(sock_net(sk), &fl4); 1103 if (!IS_ERR(rt)) { 1104 __ip_rt_update_pmtu(rt, &fl4, mtu); 1105 ip_rt_put(rt); 1106 } 1107 } 1108 1109 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1110 { 1111 const struct iphdr *iph = (const struct iphdr *)skb->data; 1112 struct flowi4 fl4; 1113 struct rtable *rt; 1114 struct dst_entry *odst = NULL; 1115 bool new = false; 1116 struct net *net = sock_net(sk); 1117 1118 bh_lock_sock(sk); 1119 1120 if (!ip_sk_accept_pmtu(sk)) 1121 goto out; 1122 1123 odst = sk_dst_get(sk); 1124 1125 if (sock_owned_by_user(sk) || !odst) { 1126 __ipv4_sk_update_pmtu(skb, sk, mtu); 1127 goto out; 1128 } 1129 1130 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1131 1132 rt = (struct rtable *)odst; 1133 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1134 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1135 if (IS_ERR(rt)) 1136 goto out; 1137 1138 new = true; 1139 } else { 1140 ip_rt_fix_tos(&fl4); 1141 } 1142 1143 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1144 1145 if (!dst_check(&rt->dst, 0)) { 1146 if (new) 1147 dst_release(&rt->dst); 1148 1149 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1150 if (IS_ERR(rt)) 1151 goto out; 1152 1153 new = true; 1154 } 1155 1156 if (new) 1157 sk_dst_set(sk, &rt->dst); 1158 1159 out: 1160 bh_unlock_sock(sk); 1161 dst_release(odst); 1162 } 1163 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1164 1165 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1166 int oif, u8 protocol) 1167 { 1168 const struct iphdr *iph = (const struct iphdr *)skb->data; 1169 struct flowi4 fl4; 1170 struct rtable *rt; 1171 1172 __build_flow_key(net, &fl4, NULL, iph, oif, 1173 RT_TOS(iph->tos), protocol, 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_redirect); 1181 1182 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1183 { 1184 const struct iphdr *iph = (const struct iphdr *)skb->data; 1185 struct flowi4 fl4; 1186 struct rtable *rt; 1187 struct net *net = sock_net(sk); 1188 1189 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1190 rt = __ip_route_output_key(net, &fl4); 1191 if (!IS_ERR(rt)) { 1192 __ip_do_redirect(rt, skb, &fl4, false); 1193 ip_rt_put(rt); 1194 } 1195 } 1196 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1197 1198 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1199 u32 cookie) 1200 { 1201 struct rtable *rt = (struct rtable *) dst; 1202 1203 /* All IPV4 dsts are created with ->obsolete set to the value 1204 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1205 * into this function always. 1206 * 1207 * When a PMTU/redirect information update invalidates a route, 1208 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1209 * DST_OBSOLETE_DEAD. 1210 */ 1211 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1212 return NULL; 1213 return dst; 1214 } 1215 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1216 1217 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1218 { 1219 struct ip_options opt; 1220 int res; 1221 1222 /* Recompile ip options since IPCB may not be valid anymore. 1223 * Also check we have a reasonable ipv4 header. 1224 */ 1225 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1226 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1227 return; 1228 1229 memset(&opt, 0, sizeof(opt)); 1230 if (ip_hdr(skb)->ihl > 5) { 1231 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1232 return; 1233 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1234 1235 rcu_read_lock(); 1236 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1237 rcu_read_unlock(); 1238 1239 if (res) 1240 return; 1241 } 1242 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1243 } 1244 1245 static void ipv4_link_failure(struct sk_buff *skb) 1246 { 1247 struct rtable *rt; 1248 1249 ipv4_send_dest_unreach(skb); 1250 1251 rt = skb_rtable(skb); 1252 if (rt) 1253 dst_set_expires(&rt->dst, 0); 1254 } 1255 1256 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1257 { 1258 pr_debug("%s: %pI4 -> %pI4, %s\n", 1259 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1260 skb->dev ? skb->dev->name : "?"); 1261 kfree_skb(skb); 1262 WARN_ON(1); 1263 return 0; 1264 } 1265 1266 /* 1267 * We do not cache source address of outgoing interface, 1268 * because it is used only by IP RR, TS and SRR options, 1269 * so that it out of fast path. 1270 * 1271 * BTW remember: "addr" is allowed to be not aligned 1272 * in IP options! 1273 */ 1274 1275 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1276 { 1277 __be32 src; 1278 1279 if (rt_is_output_route(rt)) 1280 src = ip_hdr(skb)->saddr; 1281 else { 1282 struct fib_result res; 1283 struct iphdr *iph = ip_hdr(skb); 1284 struct flowi4 fl4 = { 1285 .daddr = iph->daddr, 1286 .saddr = iph->saddr, 1287 .flowi4_tos = RT_TOS(iph->tos), 1288 .flowi4_oif = rt->dst.dev->ifindex, 1289 .flowi4_iif = skb->dev->ifindex, 1290 .flowi4_mark = skb->mark, 1291 }; 1292 1293 rcu_read_lock(); 1294 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1295 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1296 else 1297 src = inet_select_addr(rt->dst.dev, 1298 rt_nexthop(rt, iph->daddr), 1299 RT_SCOPE_UNIVERSE); 1300 rcu_read_unlock(); 1301 } 1302 memcpy(addr, &src, 4); 1303 } 1304 1305 #ifdef CONFIG_IP_ROUTE_CLASSID 1306 static void set_class_tag(struct rtable *rt, u32 tag) 1307 { 1308 if (!(rt->dst.tclassid & 0xFFFF)) 1309 rt->dst.tclassid |= tag & 0xFFFF; 1310 if (!(rt->dst.tclassid & 0xFFFF0000)) 1311 rt->dst.tclassid |= tag & 0xFFFF0000; 1312 } 1313 #endif 1314 1315 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1316 { 1317 struct net *net = dev_net(dst->dev); 1318 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1319 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1320 net->ipv4.ip_rt_min_advmss); 1321 1322 return min(advmss, IPV4_MAX_PMTU - header_size); 1323 } 1324 1325 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1326 { 1327 return ip_dst_mtu_maybe_forward(dst, false); 1328 } 1329 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1330 1331 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1332 { 1333 struct fnhe_hash_bucket *hash; 1334 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1335 u32 hval = fnhe_hashfun(daddr); 1336 1337 spin_lock_bh(&fnhe_lock); 1338 1339 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1340 lockdep_is_held(&fnhe_lock)); 1341 hash += hval; 1342 1343 fnhe_p = &hash->chain; 1344 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1345 while (fnhe) { 1346 if (fnhe->fnhe_daddr == daddr) { 1347 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1348 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1349 /* set fnhe_daddr to 0 to ensure it won't bind with 1350 * new dsts in rt_bind_exception(). 1351 */ 1352 fnhe->fnhe_daddr = 0; 1353 fnhe_flush_routes(fnhe); 1354 kfree_rcu(fnhe, rcu); 1355 break; 1356 } 1357 fnhe_p = &fnhe->fnhe_next; 1358 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1359 lockdep_is_held(&fnhe_lock)); 1360 } 1361 1362 spin_unlock_bh(&fnhe_lock); 1363 } 1364 1365 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1366 __be32 daddr) 1367 { 1368 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1369 struct fib_nh_exception *fnhe; 1370 u32 hval; 1371 1372 if (!hash) 1373 return NULL; 1374 1375 hval = fnhe_hashfun(daddr); 1376 1377 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1378 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1379 if (fnhe->fnhe_daddr == daddr) { 1380 if (fnhe->fnhe_expires && 1381 time_after(jiffies, fnhe->fnhe_expires)) { 1382 ip_del_fnhe(nhc, daddr); 1383 break; 1384 } 1385 return fnhe; 1386 } 1387 } 1388 return NULL; 1389 } 1390 1391 /* MTU selection: 1392 * 1. mtu on route is locked - use it 1393 * 2. mtu from nexthop exception 1394 * 3. mtu from egress device 1395 */ 1396 1397 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1398 { 1399 struct fib_nh_common *nhc = res->nhc; 1400 struct net_device *dev = nhc->nhc_dev; 1401 struct fib_info *fi = res->fi; 1402 u32 mtu = 0; 1403 1404 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1405 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1406 mtu = fi->fib_mtu; 1407 1408 if (likely(!mtu)) { 1409 struct fib_nh_exception *fnhe; 1410 1411 fnhe = find_exception(nhc, daddr); 1412 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1413 mtu = fnhe->fnhe_pmtu; 1414 } 1415 1416 if (likely(!mtu)) 1417 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1418 1419 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1420 } 1421 1422 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1423 __be32 daddr, const bool do_cache) 1424 { 1425 bool ret = false; 1426 1427 spin_lock_bh(&fnhe_lock); 1428 1429 if (daddr == fnhe->fnhe_daddr) { 1430 struct rtable __rcu **porig; 1431 struct rtable *orig; 1432 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1433 1434 if (rt_is_input_route(rt)) 1435 porig = &fnhe->fnhe_rth_input; 1436 else 1437 porig = &fnhe->fnhe_rth_output; 1438 orig = rcu_dereference(*porig); 1439 1440 if (fnhe->fnhe_genid != genid) { 1441 fnhe->fnhe_genid = genid; 1442 fnhe->fnhe_gw = 0; 1443 fnhe->fnhe_pmtu = 0; 1444 fnhe->fnhe_expires = 0; 1445 fnhe->fnhe_mtu_locked = false; 1446 fnhe_flush_routes(fnhe); 1447 orig = NULL; 1448 } 1449 fill_route_from_fnhe(rt, fnhe); 1450 if (!rt->rt_gw4) { 1451 rt->rt_gw4 = daddr; 1452 rt->rt_gw_family = AF_INET; 1453 } 1454 1455 if (do_cache) { 1456 dst_hold(&rt->dst); 1457 rcu_assign_pointer(*porig, rt); 1458 if (orig) { 1459 dst_dev_put(&orig->dst); 1460 dst_release(&orig->dst); 1461 } 1462 ret = true; 1463 } 1464 1465 fnhe->fnhe_stamp = jiffies; 1466 } 1467 spin_unlock_bh(&fnhe_lock); 1468 1469 return ret; 1470 } 1471 1472 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1473 { 1474 struct rtable *orig, *prev, **p; 1475 bool ret = true; 1476 1477 if (rt_is_input_route(rt)) { 1478 p = (struct rtable **)&nhc->nhc_rth_input; 1479 } else { 1480 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1481 } 1482 orig = *p; 1483 1484 /* hold dst before doing cmpxchg() to avoid race condition 1485 * on this dst 1486 */ 1487 dst_hold(&rt->dst); 1488 prev = cmpxchg(p, orig, rt); 1489 if (prev == orig) { 1490 if (orig) { 1491 rt_add_uncached_list(orig); 1492 dst_release(&orig->dst); 1493 } 1494 } else { 1495 dst_release(&rt->dst); 1496 ret = false; 1497 } 1498 1499 return ret; 1500 } 1501 1502 struct uncached_list { 1503 spinlock_t lock; 1504 struct list_head head; 1505 struct list_head quarantine; 1506 }; 1507 1508 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1509 1510 void rt_add_uncached_list(struct rtable *rt) 1511 { 1512 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1513 1514 rt->rt_uncached_list = ul; 1515 1516 spin_lock_bh(&ul->lock); 1517 list_add_tail(&rt->rt_uncached, &ul->head); 1518 spin_unlock_bh(&ul->lock); 1519 } 1520 1521 void rt_del_uncached_list(struct rtable *rt) 1522 { 1523 if (!list_empty(&rt->rt_uncached)) { 1524 struct uncached_list *ul = rt->rt_uncached_list; 1525 1526 spin_lock_bh(&ul->lock); 1527 list_del_init(&rt->rt_uncached); 1528 spin_unlock_bh(&ul->lock); 1529 } 1530 } 1531 1532 static void ipv4_dst_destroy(struct dst_entry *dst) 1533 { 1534 struct rtable *rt = (struct rtable *)dst; 1535 1536 ip_dst_metrics_put(dst); 1537 rt_del_uncached_list(rt); 1538 } 1539 1540 void rt_flush_dev(struct net_device *dev) 1541 { 1542 struct rtable *rt, *safe; 1543 int cpu; 1544 1545 for_each_possible_cpu(cpu) { 1546 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1547 1548 if (list_empty(&ul->head)) 1549 continue; 1550 1551 spin_lock_bh(&ul->lock); 1552 list_for_each_entry_safe(rt, safe, &ul->head, rt_uncached) { 1553 if (rt->dst.dev != dev) 1554 continue; 1555 rt->dst.dev = blackhole_netdev; 1556 dev_replace_track(dev, blackhole_netdev, 1557 &rt->dst.dev_tracker, 1558 GFP_ATOMIC); 1559 list_move(&rt->rt_uncached, &ul->quarantine); 1560 } 1561 spin_unlock_bh(&ul->lock); 1562 } 1563 } 1564 1565 static bool rt_cache_valid(const struct rtable *rt) 1566 { 1567 return rt && 1568 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1569 !rt_is_expired(rt); 1570 } 1571 1572 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1573 const struct fib_result *res, 1574 struct fib_nh_exception *fnhe, 1575 struct fib_info *fi, u16 type, u32 itag, 1576 const bool do_cache) 1577 { 1578 bool cached = false; 1579 1580 if (fi) { 1581 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1582 1583 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1584 rt->rt_uses_gateway = 1; 1585 rt->rt_gw_family = nhc->nhc_gw_family; 1586 /* only INET and INET6 are supported */ 1587 if (likely(nhc->nhc_gw_family == AF_INET)) 1588 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1589 else 1590 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1591 } 1592 1593 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1594 1595 #ifdef CONFIG_IP_ROUTE_CLASSID 1596 if (nhc->nhc_family == AF_INET) { 1597 struct fib_nh *nh; 1598 1599 nh = container_of(nhc, struct fib_nh, nh_common); 1600 rt->dst.tclassid = nh->nh_tclassid; 1601 } 1602 #endif 1603 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1604 if (unlikely(fnhe)) 1605 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1606 else if (do_cache) 1607 cached = rt_cache_route(nhc, rt); 1608 if (unlikely(!cached)) { 1609 /* Routes we intend to cache in nexthop exception or 1610 * FIB nexthop have the DST_NOCACHE bit clear. 1611 * However, if we are unsuccessful at storing this 1612 * route into the cache we really need to set it. 1613 */ 1614 if (!rt->rt_gw4) { 1615 rt->rt_gw_family = AF_INET; 1616 rt->rt_gw4 = daddr; 1617 } 1618 rt_add_uncached_list(rt); 1619 } 1620 } else 1621 rt_add_uncached_list(rt); 1622 1623 #ifdef CONFIG_IP_ROUTE_CLASSID 1624 #ifdef CONFIG_IP_MULTIPLE_TABLES 1625 set_class_tag(rt, res->tclassid); 1626 #endif 1627 set_class_tag(rt, itag); 1628 #endif 1629 } 1630 1631 struct rtable *rt_dst_alloc(struct net_device *dev, 1632 unsigned int flags, u16 type, 1633 bool nopolicy, bool noxfrm) 1634 { 1635 struct rtable *rt; 1636 1637 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1638 (nopolicy ? DST_NOPOLICY : 0) | 1639 (noxfrm ? DST_NOXFRM : 0)); 1640 1641 if (rt) { 1642 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1643 rt->rt_flags = flags; 1644 rt->rt_type = type; 1645 rt->rt_is_input = 0; 1646 rt->rt_iif = 0; 1647 rt->rt_pmtu = 0; 1648 rt->rt_mtu_locked = 0; 1649 rt->rt_uses_gateway = 0; 1650 rt->rt_gw_family = 0; 1651 rt->rt_gw4 = 0; 1652 INIT_LIST_HEAD(&rt->rt_uncached); 1653 1654 rt->dst.output = ip_output; 1655 if (flags & RTCF_LOCAL) 1656 rt->dst.input = ip_local_deliver; 1657 } 1658 1659 return rt; 1660 } 1661 EXPORT_SYMBOL(rt_dst_alloc); 1662 1663 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1664 { 1665 struct rtable *new_rt; 1666 1667 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1668 rt->dst.flags); 1669 1670 if (new_rt) { 1671 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1672 new_rt->rt_flags = rt->rt_flags; 1673 new_rt->rt_type = rt->rt_type; 1674 new_rt->rt_is_input = rt->rt_is_input; 1675 new_rt->rt_iif = rt->rt_iif; 1676 new_rt->rt_pmtu = rt->rt_pmtu; 1677 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1678 new_rt->rt_gw_family = rt->rt_gw_family; 1679 if (rt->rt_gw_family == AF_INET) 1680 new_rt->rt_gw4 = rt->rt_gw4; 1681 else if (rt->rt_gw_family == AF_INET6) 1682 new_rt->rt_gw6 = rt->rt_gw6; 1683 INIT_LIST_HEAD(&new_rt->rt_uncached); 1684 1685 new_rt->dst.input = rt->dst.input; 1686 new_rt->dst.output = rt->dst.output; 1687 new_rt->dst.error = rt->dst.error; 1688 new_rt->dst.lastuse = jiffies; 1689 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1690 } 1691 return new_rt; 1692 } 1693 EXPORT_SYMBOL(rt_dst_clone); 1694 1695 /* called in rcu_read_lock() section */ 1696 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1697 u8 tos, struct net_device *dev, 1698 struct in_device *in_dev, u32 *itag) 1699 { 1700 int err; 1701 1702 /* Primary sanity checks. */ 1703 if (!in_dev) 1704 return -EINVAL; 1705 1706 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1707 skb->protocol != htons(ETH_P_IP)) 1708 return -EINVAL; 1709 1710 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1711 return -EINVAL; 1712 1713 if (ipv4_is_zeronet(saddr)) { 1714 if (!ipv4_is_local_multicast(daddr) && 1715 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1716 return -EINVAL; 1717 } else { 1718 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1719 in_dev, itag); 1720 if (err < 0) 1721 return err; 1722 } 1723 return 0; 1724 } 1725 1726 /* called in rcu_read_lock() section */ 1727 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1728 u8 tos, struct net_device *dev, int our) 1729 { 1730 struct in_device *in_dev = __in_dev_get_rcu(dev); 1731 unsigned int flags = RTCF_MULTICAST; 1732 struct rtable *rth; 1733 u32 itag = 0; 1734 int err; 1735 1736 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1737 if (err) 1738 return err; 1739 1740 if (our) 1741 flags |= RTCF_LOCAL; 1742 1743 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1744 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 1745 if (!rth) 1746 return -ENOBUFS; 1747 1748 #ifdef CONFIG_IP_ROUTE_CLASSID 1749 rth->dst.tclassid = itag; 1750 #endif 1751 rth->dst.output = ip_rt_bug; 1752 rth->rt_is_input= 1; 1753 1754 #ifdef CONFIG_IP_MROUTE 1755 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1756 rth->dst.input = ip_mr_input; 1757 #endif 1758 RT_CACHE_STAT_INC(in_slow_mc); 1759 1760 skb_dst_set(skb, &rth->dst); 1761 return 0; 1762 } 1763 1764 1765 static void ip_handle_martian_source(struct net_device *dev, 1766 struct in_device *in_dev, 1767 struct sk_buff *skb, 1768 __be32 daddr, 1769 __be32 saddr) 1770 { 1771 RT_CACHE_STAT_INC(in_martian_src); 1772 #ifdef CONFIG_IP_ROUTE_VERBOSE 1773 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1774 /* 1775 * RFC1812 recommendation, if source is martian, 1776 * the only hint is MAC header. 1777 */ 1778 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1779 &daddr, &saddr, dev->name); 1780 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1781 print_hex_dump(KERN_WARNING, "ll header: ", 1782 DUMP_PREFIX_OFFSET, 16, 1, 1783 skb_mac_header(skb), 1784 dev->hard_header_len, false); 1785 } 1786 } 1787 #endif 1788 } 1789 1790 /* called in rcu_read_lock() section */ 1791 static int __mkroute_input(struct sk_buff *skb, 1792 const struct fib_result *res, 1793 struct in_device *in_dev, 1794 __be32 daddr, __be32 saddr, u32 tos) 1795 { 1796 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1797 struct net_device *dev = nhc->nhc_dev; 1798 struct fib_nh_exception *fnhe; 1799 struct rtable *rth; 1800 int err; 1801 struct in_device *out_dev; 1802 bool do_cache; 1803 u32 itag = 0; 1804 1805 /* get a working reference to the output device */ 1806 out_dev = __in_dev_get_rcu(dev); 1807 if (!out_dev) { 1808 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1809 return -EINVAL; 1810 } 1811 1812 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1813 in_dev->dev, in_dev, &itag); 1814 if (err < 0) { 1815 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1816 saddr); 1817 1818 goto cleanup; 1819 } 1820 1821 do_cache = res->fi && !itag; 1822 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1823 skb->protocol == htons(ETH_P_IP)) { 1824 __be32 gw; 1825 1826 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1827 if (IN_DEV_SHARED_MEDIA(out_dev) || 1828 inet_addr_onlink(out_dev, saddr, gw)) 1829 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1830 } 1831 1832 if (skb->protocol != htons(ETH_P_IP)) { 1833 /* Not IP (i.e. ARP). Do not create route, if it is 1834 * invalid for proxy arp. DNAT routes are always valid. 1835 * 1836 * Proxy arp feature have been extended to allow, ARP 1837 * replies back to the same interface, to support 1838 * Private VLAN switch technologies. See arp.c. 1839 */ 1840 if (out_dev == in_dev && 1841 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1842 err = -EINVAL; 1843 goto cleanup; 1844 } 1845 } 1846 1847 fnhe = find_exception(nhc, daddr); 1848 if (do_cache) { 1849 if (fnhe) 1850 rth = rcu_dereference(fnhe->fnhe_rth_input); 1851 else 1852 rth = rcu_dereference(nhc->nhc_rth_input); 1853 if (rt_cache_valid(rth)) { 1854 skb_dst_set_noref(skb, &rth->dst); 1855 goto out; 1856 } 1857 } 1858 1859 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1860 IN_DEV_ORCONF(in_dev, NOPOLICY), 1861 IN_DEV_ORCONF(out_dev, NOXFRM)); 1862 if (!rth) { 1863 err = -ENOBUFS; 1864 goto cleanup; 1865 } 1866 1867 rth->rt_is_input = 1; 1868 RT_CACHE_STAT_INC(in_slow_tot); 1869 1870 rth->dst.input = ip_forward; 1871 1872 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1873 do_cache); 1874 lwtunnel_set_redirect(&rth->dst); 1875 skb_dst_set(skb, &rth->dst); 1876 out: 1877 err = 0; 1878 cleanup: 1879 return err; 1880 } 1881 1882 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1883 /* To make ICMP packets follow the right flow, the multipath hash is 1884 * calculated from the inner IP addresses. 1885 */ 1886 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1887 struct flow_keys *hash_keys) 1888 { 1889 const struct iphdr *outer_iph = ip_hdr(skb); 1890 const struct iphdr *key_iph = outer_iph; 1891 const struct iphdr *inner_iph; 1892 const struct icmphdr *icmph; 1893 struct iphdr _inner_iph; 1894 struct icmphdr _icmph; 1895 1896 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1897 goto out; 1898 1899 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1900 goto out; 1901 1902 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1903 &_icmph); 1904 if (!icmph) 1905 goto out; 1906 1907 if (!icmp_is_err(icmph->type)) 1908 goto out; 1909 1910 inner_iph = skb_header_pointer(skb, 1911 outer_iph->ihl * 4 + sizeof(_icmph), 1912 sizeof(_inner_iph), &_inner_iph); 1913 if (!inner_iph) 1914 goto out; 1915 1916 key_iph = inner_iph; 1917 out: 1918 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1919 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1920 } 1921 1922 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1923 const struct sk_buff *skb, 1924 bool *p_has_inner) 1925 { 1926 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1927 struct flow_keys keys, hash_keys; 1928 1929 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1930 return 0; 1931 1932 memset(&hash_keys, 0, sizeof(hash_keys)); 1933 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1934 1935 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1936 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1937 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1938 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1939 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1940 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1941 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1942 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1943 hash_keys.ports.src = keys.ports.src; 1944 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1945 hash_keys.ports.dst = keys.ports.dst; 1946 1947 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1948 return flow_hash_from_keys(&hash_keys); 1949 } 1950 1951 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1952 const struct sk_buff *skb, 1953 bool has_inner) 1954 { 1955 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1956 struct flow_keys keys, hash_keys; 1957 1958 /* We assume the packet carries an encapsulation, but if none was 1959 * encountered during dissection of the outer flow, then there is no 1960 * point in calling the flow dissector again. 1961 */ 1962 if (!has_inner) 1963 return 0; 1964 1965 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1966 return 0; 1967 1968 memset(&hash_keys, 0, sizeof(hash_keys)); 1969 skb_flow_dissect_flow_keys(skb, &keys, 0); 1970 1971 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1972 return 0; 1973 1974 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1975 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1976 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1977 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1978 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1979 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1980 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1981 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1982 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1983 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1984 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1985 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1986 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1987 hash_keys.tags.flow_label = keys.tags.flow_label; 1988 } 1989 1990 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1991 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1992 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1993 hash_keys.ports.src = keys.ports.src; 1994 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1995 hash_keys.ports.dst = keys.ports.dst; 1996 1997 return flow_hash_from_keys(&hash_keys); 1998 } 1999 2000 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2001 const struct sk_buff *skb) 2002 { 2003 u32 mhash, mhash_inner; 2004 bool has_inner = true; 2005 2006 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2007 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2008 2009 return jhash_2words(mhash, mhash_inner, 0); 2010 } 2011 2012 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2013 const struct flowi4 *fl4) 2014 { 2015 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 2016 struct flow_keys hash_keys; 2017 2018 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2019 return 0; 2020 2021 memset(&hash_keys, 0, sizeof(hash_keys)); 2022 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2023 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2024 hash_keys.addrs.v4addrs.src = fl4->saddr; 2025 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2026 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2027 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2028 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2029 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2030 hash_keys.ports.src = fl4->fl4_sport; 2031 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2032 hash_keys.ports.dst = fl4->fl4_dport; 2033 2034 return flow_hash_from_keys(&hash_keys); 2035 } 2036 2037 /* if skb is set it will be used and fl4 can be NULL */ 2038 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2039 const struct sk_buff *skb, struct flow_keys *flkeys) 2040 { 2041 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2042 struct flow_keys hash_keys; 2043 u32 mhash = 0; 2044 2045 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2046 case 0: 2047 memset(&hash_keys, 0, sizeof(hash_keys)); 2048 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2049 if (skb) { 2050 ip_multipath_l3_keys(skb, &hash_keys); 2051 } else { 2052 hash_keys.addrs.v4addrs.src = fl4->saddr; 2053 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2054 } 2055 mhash = flow_hash_from_keys(&hash_keys); 2056 break; 2057 case 1: 2058 /* skb is currently provided only when forwarding */ 2059 if (skb) { 2060 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2061 struct flow_keys keys; 2062 2063 /* short-circuit if we already have L4 hash present */ 2064 if (skb->l4_hash) 2065 return skb_get_hash_raw(skb) >> 1; 2066 2067 memset(&hash_keys, 0, sizeof(hash_keys)); 2068 2069 if (!flkeys) { 2070 skb_flow_dissect_flow_keys(skb, &keys, flag); 2071 flkeys = &keys; 2072 } 2073 2074 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2075 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2076 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2077 hash_keys.ports.src = flkeys->ports.src; 2078 hash_keys.ports.dst = flkeys->ports.dst; 2079 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2080 } else { 2081 memset(&hash_keys, 0, sizeof(hash_keys)); 2082 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2083 hash_keys.addrs.v4addrs.src = fl4->saddr; 2084 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2085 hash_keys.ports.src = fl4->fl4_sport; 2086 hash_keys.ports.dst = fl4->fl4_dport; 2087 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2088 } 2089 mhash = flow_hash_from_keys(&hash_keys); 2090 break; 2091 case 2: 2092 memset(&hash_keys, 0, sizeof(hash_keys)); 2093 /* skb is currently provided only when forwarding */ 2094 if (skb) { 2095 struct flow_keys keys; 2096 2097 skb_flow_dissect_flow_keys(skb, &keys, 0); 2098 /* Inner can be v4 or v6 */ 2099 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2100 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2101 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2102 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2103 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2104 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2105 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2106 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2107 hash_keys.tags.flow_label = keys.tags.flow_label; 2108 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2109 } else { 2110 /* Same as case 0 */ 2111 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2112 ip_multipath_l3_keys(skb, &hash_keys); 2113 } 2114 } else { 2115 /* Same as case 0 */ 2116 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2117 hash_keys.addrs.v4addrs.src = fl4->saddr; 2118 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2119 } 2120 mhash = flow_hash_from_keys(&hash_keys); 2121 break; 2122 case 3: 2123 if (skb) 2124 mhash = fib_multipath_custom_hash_skb(net, skb); 2125 else 2126 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2127 break; 2128 } 2129 2130 if (multipath_hash) 2131 mhash = jhash_2words(mhash, multipath_hash, 0); 2132 2133 return mhash >> 1; 2134 } 2135 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2136 2137 static int ip_mkroute_input(struct sk_buff *skb, 2138 struct fib_result *res, 2139 struct in_device *in_dev, 2140 __be32 daddr, __be32 saddr, u32 tos, 2141 struct flow_keys *hkeys) 2142 { 2143 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2144 if (res->fi && fib_info_num_path(res->fi) > 1) { 2145 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2146 2147 fib_select_multipath(res, h); 2148 } 2149 #endif 2150 2151 /* create a routing cache entry */ 2152 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2153 } 2154 2155 /* Implements all the saddr-related checks as ip_route_input_slow(), 2156 * assuming daddr is valid and the destination is not a local broadcast one. 2157 * Uses the provided hint instead of performing a route lookup. 2158 */ 2159 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2160 u8 tos, struct net_device *dev, 2161 const struct sk_buff *hint) 2162 { 2163 struct in_device *in_dev = __in_dev_get_rcu(dev); 2164 struct rtable *rt = skb_rtable(hint); 2165 struct net *net = dev_net(dev); 2166 int err = -EINVAL; 2167 u32 tag = 0; 2168 2169 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2170 goto martian_source; 2171 2172 if (ipv4_is_zeronet(saddr)) 2173 goto martian_source; 2174 2175 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2176 goto martian_source; 2177 2178 if (rt->rt_type != RTN_LOCAL) 2179 goto skip_validate_source; 2180 2181 tos &= IPTOS_RT_MASK; 2182 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2183 if (err < 0) 2184 goto martian_source; 2185 2186 skip_validate_source: 2187 skb_dst_copy(skb, hint); 2188 return 0; 2189 2190 martian_source: 2191 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2192 return err; 2193 } 2194 2195 /* get device for dst_alloc with local routes */ 2196 static struct net_device *ip_rt_get_dev(struct net *net, 2197 const struct fib_result *res) 2198 { 2199 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2200 struct net_device *dev = NULL; 2201 2202 if (nhc) 2203 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2204 2205 return dev ? : net->loopback_dev; 2206 } 2207 2208 /* 2209 * NOTE. We drop all the packets that has local source 2210 * addresses, because every properly looped back packet 2211 * must have correct destination already attached by output routine. 2212 * Changes in the enforced policies must be applied also to 2213 * ip_route_use_hint(). 2214 * 2215 * Such approach solves two big problems: 2216 * 1. Not simplex devices are handled properly. 2217 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2218 * called with rcu_read_lock() 2219 */ 2220 2221 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2222 u8 tos, struct net_device *dev, 2223 struct fib_result *res) 2224 { 2225 struct in_device *in_dev = __in_dev_get_rcu(dev); 2226 struct flow_keys *flkeys = NULL, _flkeys; 2227 struct net *net = dev_net(dev); 2228 struct ip_tunnel_info *tun_info; 2229 int err = -EINVAL; 2230 unsigned int flags = 0; 2231 u32 itag = 0; 2232 struct rtable *rth; 2233 struct flowi4 fl4; 2234 bool do_cache = true; 2235 2236 /* IP on this device is disabled. */ 2237 2238 if (!in_dev) 2239 goto out; 2240 2241 /* Check for the most weird martians, which can be not detected 2242 * by fib_lookup. 2243 */ 2244 2245 tun_info = skb_tunnel_info(skb); 2246 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2247 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2248 else 2249 fl4.flowi4_tun_key.tun_id = 0; 2250 skb_dst_drop(skb); 2251 2252 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2253 goto martian_source; 2254 2255 res->fi = NULL; 2256 res->table = NULL; 2257 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2258 goto brd_input; 2259 2260 /* Accept zero addresses only to limited broadcast; 2261 * I even do not know to fix it or not. Waiting for complains :-) 2262 */ 2263 if (ipv4_is_zeronet(saddr)) 2264 goto martian_source; 2265 2266 if (ipv4_is_zeronet(daddr)) 2267 goto martian_destination; 2268 2269 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2270 * and call it once if daddr or/and saddr are loopback addresses 2271 */ 2272 if (ipv4_is_loopback(daddr)) { 2273 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2274 goto martian_destination; 2275 } else if (ipv4_is_loopback(saddr)) { 2276 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2277 goto martian_source; 2278 } 2279 2280 /* 2281 * Now we are ready to route packet. 2282 */ 2283 fl4.flowi4_l3mdev = 0; 2284 fl4.flowi4_oif = 0; 2285 fl4.flowi4_iif = dev->ifindex; 2286 fl4.flowi4_mark = skb->mark; 2287 fl4.flowi4_tos = tos; 2288 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2289 fl4.flowi4_flags = 0; 2290 fl4.daddr = daddr; 2291 fl4.saddr = saddr; 2292 fl4.flowi4_uid = sock_net_uid(net, NULL); 2293 fl4.flowi4_multipath_hash = 0; 2294 2295 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2296 flkeys = &_flkeys; 2297 } else { 2298 fl4.flowi4_proto = 0; 2299 fl4.fl4_sport = 0; 2300 fl4.fl4_dport = 0; 2301 } 2302 2303 err = fib_lookup(net, &fl4, res, 0); 2304 if (err != 0) { 2305 if (!IN_DEV_FORWARD(in_dev)) 2306 err = -EHOSTUNREACH; 2307 goto no_route; 2308 } 2309 2310 if (res->type == RTN_BROADCAST) { 2311 if (IN_DEV_BFORWARD(in_dev)) 2312 goto make_route; 2313 /* not do cache if bc_forwarding is enabled */ 2314 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2315 do_cache = false; 2316 goto brd_input; 2317 } 2318 2319 if (res->type == RTN_LOCAL) { 2320 err = fib_validate_source(skb, saddr, daddr, tos, 2321 0, dev, in_dev, &itag); 2322 if (err < 0) 2323 goto martian_source; 2324 goto local_input; 2325 } 2326 2327 if (!IN_DEV_FORWARD(in_dev)) { 2328 err = -EHOSTUNREACH; 2329 goto no_route; 2330 } 2331 if (res->type != RTN_UNICAST) 2332 goto martian_destination; 2333 2334 make_route: 2335 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2336 out: return err; 2337 2338 brd_input: 2339 if (skb->protocol != htons(ETH_P_IP)) 2340 goto e_inval; 2341 2342 if (!ipv4_is_zeronet(saddr)) { 2343 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2344 in_dev, &itag); 2345 if (err < 0) 2346 goto martian_source; 2347 } 2348 flags |= RTCF_BROADCAST; 2349 res->type = RTN_BROADCAST; 2350 RT_CACHE_STAT_INC(in_brd); 2351 2352 local_input: 2353 do_cache &= res->fi && !itag; 2354 if (do_cache) { 2355 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2356 2357 rth = rcu_dereference(nhc->nhc_rth_input); 2358 if (rt_cache_valid(rth)) { 2359 skb_dst_set_noref(skb, &rth->dst); 2360 err = 0; 2361 goto out; 2362 } 2363 } 2364 2365 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2366 flags | RTCF_LOCAL, res->type, 2367 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 2368 if (!rth) 2369 goto e_nobufs; 2370 2371 rth->dst.output= ip_rt_bug; 2372 #ifdef CONFIG_IP_ROUTE_CLASSID 2373 rth->dst.tclassid = itag; 2374 #endif 2375 rth->rt_is_input = 1; 2376 2377 RT_CACHE_STAT_INC(in_slow_tot); 2378 if (res->type == RTN_UNREACHABLE) { 2379 rth->dst.input= ip_error; 2380 rth->dst.error= -err; 2381 rth->rt_flags &= ~RTCF_LOCAL; 2382 } 2383 2384 if (do_cache) { 2385 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2386 2387 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2388 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2389 WARN_ON(rth->dst.input == lwtunnel_input); 2390 rth->dst.lwtstate->orig_input = rth->dst.input; 2391 rth->dst.input = lwtunnel_input; 2392 } 2393 2394 if (unlikely(!rt_cache_route(nhc, rth))) 2395 rt_add_uncached_list(rth); 2396 } 2397 skb_dst_set(skb, &rth->dst); 2398 err = 0; 2399 goto out; 2400 2401 no_route: 2402 RT_CACHE_STAT_INC(in_no_route); 2403 res->type = RTN_UNREACHABLE; 2404 res->fi = NULL; 2405 res->table = NULL; 2406 goto local_input; 2407 2408 /* 2409 * Do not cache martian addresses: they should be logged (RFC1812) 2410 */ 2411 martian_destination: 2412 RT_CACHE_STAT_INC(in_martian_dst); 2413 #ifdef CONFIG_IP_ROUTE_VERBOSE 2414 if (IN_DEV_LOG_MARTIANS(in_dev)) 2415 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2416 &daddr, &saddr, dev->name); 2417 #endif 2418 2419 e_inval: 2420 err = -EINVAL; 2421 goto out; 2422 2423 e_nobufs: 2424 err = -ENOBUFS; 2425 goto out; 2426 2427 martian_source: 2428 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2429 goto out; 2430 } 2431 2432 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2433 u8 tos, struct net_device *dev) 2434 { 2435 struct fib_result res; 2436 int err; 2437 2438 tos &= IPTOS_RT_MASK; 2439 rcu_read_lock(); 2440 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2441 rcu_read_unlock(); 2442 2443 return err; 2444 } 2445 EXPORT_SYMBOL(ip_route_input_noref); 2446 2447 /* called with rcu_read_lock held */ 2448 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2449 u8 tos, struct net_device *dev, struct fib_result *res) 2450 { 2451 /* Multicast recognition logic is moved from route cache to here. 2452 * The problem was that too many Ethernet cards have broken/missing 2453 * hardware multicast filters :-( As result the host on multicasting 2454 * network acquires a lot of useless route cache entries, sort of 2455 * SDR messages from all the world. Now we try to get rid of them. 2456 * Really, provided software IP multicast filter is organized 2457 * reasonably (at least, hashed), it does not result in a slowdown 2458 * comparing with route cache reject entries. 2459 * Note, that multicast routers are not affected, because 2460 * route cache entry is created eventually. 2461 */ 2462 if (ipv4_is_multicast(daddr)) { 2463 struct in_device *in_dev = __in_dev_get_rcu(dev); 2464 int our = 0; 2465 int err = -EINVAL; 2466 2467 if (!in_dev) 2468 return err; 2469 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2470 ip_hdr(skb)->protocol); 2471 2472 /* check l3 master if no match yet */ 2473 if (!our && netif_is_l3_slave(dev)) { 2474 struct in_device *l3_in_dev; 2475 2476 l3_in_dev = __in_dev_get_rcu(skb->dev); 2477 if (l3_in_dev) 2478 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2479 ip_hdr(skb)->protocol); 2480 } 2481 2482 if (our 2483 #ifdef CONFIG_IP_MROUTE 2484 || 2485 (!ipv4_is_local_multicast(daddr) && 2486 IN_DEV_MFORWARD(in_dev)) 2487 #endif 2488 ) { 2489 err = ip_route_input_mc(skb, daddr, saddr, 2490 tos, dev, our); 2491 } 2492 return err; 2493 } 2494 2495 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2496 } 2497 2498 /* called with rcu_read_lock() */ 2499 static struct rtable *__mkroute_output(const struct fib_result *res, 2500 const struct flowi4 *fl4, int orig_oif, 2501 struct net_device *dev_out, 2502 unsigned int flags) 2503 { 2504 struct fib_info *fi = res->fi; 2505 struct fib_nh_exception *fnhe; 2506 struct in_device *in_dev; 2507 u16 type = res->type; 2508 struct rtable *rth; 2509 bool do_cache; 2510 2511 in_dev = __in_dev_get_rcu(dev_out); 2512 if (!in_dev) 2513 return ERR_PTR(-EINVAL); 2514 2515 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2516 if (ipv4_is_loopback(fl4->saddr) && 2517 !(dev_out->flags & IFF_LOOPBACK) && 2518 !netif_is_l3_master(dev_out)) 2519 return ERR_PTR(-EINVAL); 2520 2521 if (ipv4_is_lbcast(fl4->daddr)) 2522 type = RTN_BROADCAST; 2523 else if (ipv4_is_multicast(fl4->daddr)) 2524 type = RTN_MULTICAST; 2525 else if (ipv4_is_zeronet(fl4->daddr)) 2526 return ERR_PTR(-EINVAL); 2527 2528 if (dev_out->flags & IFF_LOOPBACK) 2529 flags |= RTCF_LOCAL; 2530 2531 do_cache = true; 2532 if (type == RTN_BROADCAST) { 2533 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2534 fi = NULL; 2535 } else if (type == RTN_MULTICAST) { 2536 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2537 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2538 fl4->flowi4_proto)) 2539 flags &= ~RTCF_LOCAL; 2540 else 2541 do_cache = false; 2542 /* If multicast route do not exist use 2543 * default one, but do not gateway in this case. 2544 * Yes, it is hack. 2545 */ 2546 if (fi && res->prefixlen < 4) 2547 fi = NULL; 2548 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2549 (orig_oif != dev_out->ifindex)) { 2550 /* For local routes that require a particular output interface 2551 * we do not want to cache the result. Caching the result 2552 * causes incorrect behaviour when there are multiple source 2553 * addresses on the interface, the end result being that if the 2554 * intended recipient is waiting on that interface for the 2555 * packet he won't receive it because it will be delivered on 2556 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2557 * be set to the loopback interface as well. 2558 */ 2559 do_cache = false; 2560 } 2561 2562 fnhe = NULL; 2563 do_cache &= fi != NULL; 2564 if (fi) { 2565 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2566 struct rtable __rcu **prth; 2567 2568 fnhe = find_exception(nhc, fl4->daddr); 2569 if (!do_cache) 2570 goto add; 2571 if (fnhe) { 2572 prth = &fnhe->fnhe_rth_output; 2573 } else { 2574 if (unlikely(fl4->flowi4_flags & 2575 FLOWI_FLAG_KNOWN_NH && 2576 !(nhc->nhc_gw_family && 2577 nhc->nhc_scope == RT_SCOPE_LINK))) { 2578 do_cache = false; 2579 goto add; 2580 } 2581 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2582 } 2583 rth = rcu_dereference(*prth); 2584 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2585 return rth; 2586 } 2587 2588 add: 2589 rth = rt_dst_alloc(dev_out, flags, type, 2590 IN_DEV_ORCONF(in_dev, NOPOLICY), 2591 IN_DEV_ORCONF(in_dev, NOXFRM)); 2592 if (!rth) 2593 return ERR_PTR(-ENOBUFS); 2594 2595 rth->rt_iif = orig_oif; 2596 2597 RT_CACHE_STAT_INC(out_slow_tot); 2598 2599 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2600 if (flags & RTCF_LOCAL && 2601 !(dev_out->flags & IFF_LOOPBACK)) { 2602 rth->dst.output = ip_mc_output; 2603 RT_CACHE_STAT_INC(out_slow_mc); 2604 } 2605 #ifdef CONFIG_IP_MROUTE 2606 if (type == RTN_MULTICAST) { 2607 if (IN_DEV_MFORWARD(in_dev) && 2608 !ipv4_is_local_multicast(fl4->daddr)) { 2609 rth->dst.input = ip_mr_input; 2610 rth->dst.output = ip_mc_output; 2611 } 2612 } 2613 #endif 2614 } 2615 2616 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2617 lwtunnel_set_redirect(&rth->dst); 2618 2619 return rth; 2620 } 2621 2622 /* 2623 * Major route resolver routine. 2624 */ 2625 2626 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2627 const struct sk_buff *skb) 2628 { 2629 struct fib_result res = { 2630 .type = RTN_UNSPEC, 2631 .fi = NULL, 2632 .table = NULL, 2633 .tclassid = 0, 2634 }; 2635 struct rtable *rth; 2636 2637 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2638 ip_rt_fix_tos(fl4); 2639 2640 rcu_read_lock(); 2641 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2642 rcu_read_unlock(); 2643 2644 return rth; 2645 } 2646 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2647 2648 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2649 struct fib_result *res, 2650 const struct sk_buff *skb) 2651 { 2652 struct net_device *dev_out = NULL; 2653 int orig_oif = fl4->flowi4_oif; 2654 unsigned int flags = 0; 2655 struct rtable *rth; 2656 int err; 2657 2658 if (fl4->saddr) { 2659 if (ipv4_is_multicast(fl4->saddr) || 2660 ipv4_is_lbcast(fl4->saddr) || 2661 ipv4_is_zeronet(fl4->saddr)) { 2662 rth = ERR_PTR(-EINVAL); 2663 goto out; 2664 } 2665 2666 rth = ERR_PTR(-ENETUNREACH); 2667 2668 /* I removed check for oif == dev_out->oif here. 2669 * It was wrong for two reasons: 2670 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2671 * is assigned to multiple interfaces. 2672 * 2. Moreover, we are allowed to send packets with saddr 2673 * of another iface. --ANK 2674 */ 2675 2676 if (fl4->flowi4_oif == 0 && 2677 (ipv4_is_multicast(fl4->daddr) || 2678 ipv4_is_lbcast(fl4->daddr))) { 2679 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2680 dev_out = __ip_dev_find(net, fl4->saddr, false); 2681 if (!dev_out) 2682 goto out; 2683 2684 /* Special hack: user can direct multicasts 2685 * and limited broadcast via necessary interface 2686 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2687 * This hack is not just for fun, it allows 2688 * vic,vat and friends to work. 2689 * They bind socket to loopback, set ttl to zero 2690 * and expect that it will work. 2691 * From the viewpoint of routing cache they are broken, 2692 * because we are not allowed to build multicast path 2693 * with loopback source addr (look, routing cache 2694 * cannot know, that ttl is zero, so that packet 2695 * will not leave this host and route is valid). 2696 * Luckily, this hack is good workaround. 2697 */ 2698 2699 fl4->flowi4_oif = dev_out->ifindex; 2700 goto make_route; 2701 } 2702 2703 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2704 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2705 if (!__ip_dev_find(net, fl4->saddr, false)) 2706 goto out; 2707 } 2708 } 2709 2710 2711 if (fl4->flowi4_oif) { 2712 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2713 rth = ERR_PTR(-ENODEV); 2714 if (!dev_out) 2715 goto out; 2716 2717 /* RACE: Check return value of inet_select_addr instead. */ 2718 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2719 rth = ERR_PTR(-ENETUNREACH); 2720 goto out; 2721 } 2722 if (ipv4_is_local_multicast(fl4->daddr) || 2723 ipv4_is_lbcast(fl4->daddr) || 2724 fl4->flowi4_proto == IPPROTO_IGMP) { 2725 if (!fl4->saddr) 2726 fl4->saddr = inet_select_addr(dev_out, 0, 2727 RT_SCOPE_LINK); 2728 goto make_route; 2729 } 2730 if (!fl4->saddr) { 2731 if (ipv4_is_multicast(fl4->daddr)) 2732 fl4->saddr = inet_select_addr(dev_out, 0, 2733 fl4->flowi4_scope); 2734 else if (!fl4->daddr) 2735 fl4->saddr = inet_select_addr(dev_out, 0, 2736 RT_SCOPE_HOST); 2737 } 2738 } 2739 2740 if (!fl4->daddr) { 2741 fl4->daddr = fl4->saddr; 2742 if (!fl4->daddr) 2743 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2744 dev_out = net->loopback_dev; 2745 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2746 res->type = RTN_LOCAL; 2747 flags |= RTCF_LOCAL; 2748 goto make_route; 2749 } 2750 2751 err = fib_lookup(net, fl4, res, 0); 2752 if (err) { 2753 res->fi = NULL; 2754 res->table = NULL; 2755 if (fl4->flowi4_oif && 2756 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2757 /* Apparently, routing tables are wrong. Assume, 2758 * that the destination is on link. 2759 * 2760 * WHY? DW. 2761 * Because we are allowed to send to iface 2762 * even if it has NO routes and NO assigned 2763 * addresses. When oif is specified, routing 2764 * tables are looked up with only one purpose: 2765 * to catch if destination is gatewayed, rather than 2766 * direct. Moreover, if MSG_DONTROUTE is set, 2767 * we send packet, ignoring both routing tables 2768 * and ifaddr state. --ANK 2769 * 2770 * 2771 * We could make it even if oif is unknown, 2772 * likely IPv6, but we do not. 2773 */ 2774 2775 if (fl4->saddr == 0) 2776 fl4->saddr = inet_select_addr(dev_out, 0, 2777 RT_SCOPE_LINK); 2778 res->type = RTN_UNICAST; 2779 goto make_route; 2780 } 2781 rth = ERR_PTR(err); 2782 goto out; 2783 } 2784 2785 if (res->type == RTN_LOCAL) { 2786 if (!fl4->saddr) { 2787 if (res->fi->fib_prefsrc) 2788 fl4->saddr = res->fi->fib_prefsrc; 2789 else 2790 fl4->saddr = fl4->daddr; 2791 } 2792 2793 /* L3 master device is the loopback for that domain */ 2794 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2795 net->loopback_dev; 2796 2797 /* make sure orig_oif points to fib result device even 2798 * though packet rx/tx happens over loopback or l3mdev 2799 */ 2800 orig_oif = FIB_RES_OIF(*res); 2801 2802 fl4->flowi4_oif = dev_out->ifindex; 2803 flags |= RTCF_LOCAL; 2804 goto make_route; 2805 } 2806 2807 fib_select_path(net, res, fl4, skb); 2808 2809 dev_out = FIB_RES_DEV(*res); 2810 2811 make_route: 2812 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2813 2814 out: 2815 return rth; 2816 } 2817 2818 static struct dst_ops ipv4_dst_blackhole_ops = { 2819 .family = AF_INET, 2820 .default_advmss = ipv4_default_advmss, 2821 .neigh_lookup = ipv4_neigh_lookup, 2822 .check = dst_blackhole_check, 2823 .cow_metrics = dst_blackhole_cow_metrics, 2824 .update_pmtu = dst_blackhole_update_pmtu, 2825 .redirect = dst_blackhole_redirect, 2826 .mtu = dst_blackhole_mtu, 2827 }; 2828 2829 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2830 { 2831 struct rtable *ort = (struct rtable *) dst_orig; 2832 struct rtable *rt; 2833 2834 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2835 if (rt) { 2836 struct dst_entry *new = &rt->dst; 2837 2838 new->__use = 1; 2839 new->input = dst_discard; 2840 new->output = dst_discard_out; 2841 2842 new->dev = net->loopback_dev; 2843 dev_hold_track(new->dev, &new->dev_tracker, GFP_ATOMIC); 2844 2845 rt->rt_is_input = ort->rt_is_input; 2846 rt->rt_iif = ort->rt_iif; 2847 rt->rt_pmtu = ort->rt_pmtu; 2848 rt->rt_mtu_locked = ort->rt_mtu_locked; 2849 2850 rt->rt_genid = rt_genid_ipv4(net); 2851 rt->rt_flags = ort->rt_flags; 2852 rt->rt_type = ort->rt_type; 2853 rt->rt_uses_gateway = ort->rt_uses_gateway; 2854 rt->rt_gw_family = ort->rt_gw_family; 2855 if (rt->rt_gw_family == AF_INET) 2856 rt->rt_gw4 = ort->rt_gw4; 2857 else if (rt->rt_gw_family == AF_INET6) 2858 rt->rt_gw6 = ort->rt_gw6; 2859 2860 INIT_LIST_HEAD(&rt->rt_uncached); 2861 } 2862 2863 dst_release(dst_orig); 2864 2865 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2866 } 2867 2868 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2869 const struct sock *sk) 2870 { 2871 struct rtable *rt = __ip_route_output_key(net, flp4); 2872 2873 if (IS_ERR(rt)) 2874 return rt; 2875 2876 if (flp4->flowi4_proto) { 2877 flp4->flowi4_oif = rt->dst.dev->ifindex; 2878 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2879 flowi4_to_flowi(flp4), 2880 sk, 0); 2881 } 2882 2883 return rt; 2884 } 2885 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2886 2887 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2888 struct net_device *dev, 2889 struct net *net, __be32 *saddr, 2890 const struct ip_tunnel_info *info, 2891 u8 protocol, bool use_cache) 2892 { 2893 #ifdef CONFIG_DST_CACHE 2894 struct dst_cache *dst_cache; 2895 #endif 2896 struct rtable *rt = NULL; 2897 struct flowi4 fl4; 2898 __u8 tos; 2899 2900 #ifdef CONFIG_DST_CACHE 2901 dst_cache = (struct dst_cache *)&info->dst_cache; 2902 if (use_cache) { 2903 rt = dst_cache_get_ip4(dst_cache, saddr); 2904 if (rt) 2905 return rt; 2906 } 2907 #endif 2908 memset(&fl4, 0, sizeof(fl4)); 2909 fl4.flowi4_mark = skb->mark; 2910 fl4.flowi4_proto = protocol; 2911 fl4.daddr = info->key.u.ipv4.dst; 2912 fl4.saddr = info->key.u.ipv4.src; 2913 tos = info->key.tos; 2914 fl4.flowi4_tos = RT_TOS(tos); 2915 2916 rt = ip_route_output_key(net, &fl4); 2917 if (IS_ERR(rt)) { 2918 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2919 return ERR_PTR(-ENETUNREACH); 2920 } 2921 if (rt->dst.dev == dev) { /* is this necessary? */ 2922 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2923 ip_rt_put(rt); 2924 return ERR_PTR(-ELOOP); 2925 } 2926 #ifdef CONFIG_DST_CACHE 2927 if (use_cache) 2928 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2929 #endif 2930 *saddr = fl4.saddr; 2931 return rt; 2932 } 2933 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2934 2935 /* called with rcu_read_lock held */ 2936 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2937 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2938 struct sk_buff *skb, u32 portid, u32 seq, 2939 unsigned int flags) 2940 { 2941 struct rtmsg *r; 2942 struct nlmsghdr *nlh; 2943 unsigned long expires = 0; 2944 u32 error; 2945 u32 metrics[RTAX_MAX]; 2946 2947 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2948 if (!nlh) 2949 return -EMSGSIZE; 2950 2951 r = nlmsg_data(nlh); 2952 r->rtm_family = AF_INET; 2953 r->rtm_dst_len = 32; 2954 r->rtm_src_len = 0; 2955 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2956 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2957 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2958 goto nla_put_failure; 2959 r->rtm_type = rt->rt_type; 2960 r->rtm_scope = RT_SCOPE_UNIVERSE; 2961 r->rtm_protocol = RTPROT_UNSPEC; 2962 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2963 if (rt->rt_flags & RTCF_NOTIFY) 2964 r->rtm_flags |= RTM_F_NOTIFY; 2965 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2966 r->rtm_flags |= RTCF_DOREDIRECT; 2967 2968 if (nla_put_in_addr(skb, RTA_DST, dst)) 2969 goto nla_put_failure; 2970 if (src) { 2971 r->rtm_src_len = 32; 2972 if (nla_put_in_addr(skb, RTA_SRC, src)) 2973 goto nla_put_failure; 2974 } 2975 if (rt->dst.dev && 2976 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2977 goto nla_put_failure; 2978 if (rt->dst.lwtstate && 2979 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2980 goto nla_put_failure; 2981 #ifdef CONFIG_IP_ROUTE_CLASSID 2982 if (rt->dst.tclassid && 2983 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2984 goto nla_put_failure; 2985 #endif 2986 if (fl4 && !rt_is_input_route(rt) && 2987 fl4->saddr != src) { 2988 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2989 goto nla_put_failure; 2990 } 2991 if (rt->rt_uses_gateway) { 2992 if (rt->rt_gw_family == AF_INET && 2993 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2994 goto nla_put_failure; 2995 } else if (rt->rt_gw_family == AF_INET6) { 2996 int alen = sizeof(struct in6_addr); 2997 struct nlattr *nla; 2998 struct rtvia *via; 2999 3000 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3001 if (!nla) 3002 goto nla_put_failure; 3003 3004 via = nla_data(nla); 3005 via->rtvia_family = AF_INET6; 3006 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3007 } 3008 } 3009 3010 expires = rt->dst.expires; 3011 if (expires) { 3012 unsigned long now = jiffies; 3013 3014 if (time_before(now, expires)) 3015 expires -= now; 3016 else 3017 expires = 0; 3018 } 3019 3020 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3021 if (rt->rt_pmtu && expires) 3022 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3023 if (rt->rt_mtu_locked && expires) 3024 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3025 if (rtnetlink_put_metrics(skb, metrics) < 0) 3026 goto nla_put_failure; 3027 3028 if (fl4) { 3029 if (fl4->flowi4_mark && 3030 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3031 goto nla_put_failure; 3032 3033 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3034 nla_put_u32(skb, RTA_UID, 3035 from_kuid_munged(current_user_ns(), 3036 fl4->flowi4_uid))) 3037 goto nla_put_failure; 3038 3039 if (rt_is_input_route(rt)) { 3040 #ifdef CONFIG_IP_MROUTE 3041 if (ipv4_is_multicast(dst) && 3042 !ipv4_is_local_multicast(dst) && 3043 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3044 int err = ipmr_get_route(net, skb, 3045 fl4->saddr, fl4->daddr, 3046 r, portid); 3047 3048 if (err <= 0) { 3049 if (err == 0) 3050 return 0; 3051 goto nla_put_failure; 3052 } 3053 } else 3054 #endif 3055 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3056 goto nla_put_failure; 3057 } 3058 } 3059 3060 error = rt->dst.error; 3061 3062 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3063 goto nla_put_failure; 3064 3065 nlmsg_end(skb, nlh); 3066 return 0; 3067 3068 nla_put_failure: 3069 nlmsg_cancel(skb, nlh); 3070 return -EMSGSIZE; 3071 } 3072 3073 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3074 struct netlink_callback *cb, u32 table_id, 3075 struct fnhe_hash_bucket *bucket, int genid, 3076 int *fa_index, int fa_start, unsigned int flags) 3077 { 3078 int i; 3079 3080 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3081 struct fib_nh_exception *fnhe; 3082 3083 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3084 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3085 struct rtable *rt; 3086 int err; 3087 3088 if (*fa_index < fa_start) 3089 goto next; 3090 3091 if (fnhe->fnhe_genid != genid) 3092 goto next; 3093 3094 if (fnhe->fnhe_expires && 3095 time_after(jiffies, fnhe->fnhe_expires)) 3096 goto next; 3097 3098 rt = rcu_dereference(fnhe->fnhe_rth_input); 3099 if (!rt) 3100 rt = rcu_dereference(fnhe->fnhe_rth_output); 3101 if (!rt) 3102 goto next; 3103 3104 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3105 table_id, NULL, skb, 3106 NETLINK_CB(cb->skb).portid, 3107 cb->nlh->nlmsg_seq, flags); 3108 if (err) 3109 return err; 3110 next: 3111 (*fa_index)++; 3112 } 3113 } 3114 3115 return 0; 3116 } 3117 3118 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3119 u32 table_id, struct fib_info *fi, 3120 int *fa_index, int fa_start, unsigned int flags) 3121 { 3122 struct net *net = sock_net(cb->skb->sk); 3123 int nhsel, genid = fnhe_genid(net); 3124 3125 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3126 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3127 struct fnhe_hash_bucket *bucket; 3128 int err; 3129 3130 if (nhc->nhc_flags & RTNH_F_DEAD) 3131 continue; 3132 3133 rcu_read_lock(); 3134 bucket = rcu_dereference(nhc->nhc_exceptions); 3135 err = 0; 3136 if (bucket) 3137 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3138 genid, fa_index, fa_start, 3139 flags); 3140 rcu_read_unlock(); 3141 if (err) 3142 return err; 3143 } 3144 3145 return 0; 3146 } 3147 3148 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3149 u8 ip_proto, __be16 sport, 3150 __be16 dport) 3151 { 3152 struct sk_buff *skb; 3153 struct iphdr *iph; 3154 3155 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3156 if (!skb) 3157 return NULL; 3158 3159 /* Reserve room for dummy headers, this skb can pass 3160 * through good chunk of routing engine. 3161 */ 3162 skb_reset_mac_header(skb); 3163 skb_reset_network_header(skb); 3164 skb->protocol = htons(ETH_P_IP); 3165 iph = skb_put(skb, sizeof(struct iphdr)); 3166 iph->protocol = ip_proto; 3167 iph->saddr = src; 3168 iph->daddr = dst; 3169 iph->version = 0x4; 3170 iph->frag_off = 0; 3171 iph->ihl = 0x5; 3172 skb_set_transport_header(skb, skb->len); 3173 3174 switch (iph->protocol) { 3175 case IPPROTO_UDP: { 3176 struct udphdr *udph; 3177 3178 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3179 udph->source = sport; 3180 udph->dest = dport; 3181 udph->len = htons(sizeof(struct udphdr)); 3182 udph->check = 0; 3183 break; 3184 } 3185 case IPPROTO_TCP: { 3186 struct tcphdr *tcph; 3187 3188 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3189 tcph->source = sport; 3190 tcph->dest = dport; 3191 tcph->doff = sizeof(struct tcphdr) / 4; 3192 tcph->rst = 1; 3193 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3194 src, dst, 0); 3195 break; 3196 } 3197 case IPPROTO_ICMP: { 3198 struct icmphdr *icmph; 3199 3200 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3201 icmph->type = ICMP_ECHO; 3202 icmph->code = 0; 3203 } 3204 } 3205 3206 return skb; 3207 } 3208 3209 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3210 const struct nlmsghdr *nlh, 3211 struct nlattr **tb, 3212 struct netlink_ext_ack *extack) 3213 { 3214 struct rtmsg *rtm; 3215 int i, err; 3216 3217 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3218 NL_SET_ERR_MSG(extack, 3219 "ipv4: Invalid header for route get request"); 3220 return -EINVAL; 3221 } 3222 3223 if (!netlink_strict_get_check(skb)) 3224 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3225 rtm_ipv4_policy, extack); 3226 3227 rtm = nlmsg_data(nlh); 3228 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3229 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3230 rtm->rtm_table || rtm->rtm_protocol || 3231 rtm->rtm_scope || rtm->rtm_type) { 3232 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3233 return -EINVAL; 3234 } 3235 3236 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3237 RTM_F_LOOKUP_TABLE | 3238 RTM_F_FIB_MATCH)) { 3239 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3240 return -EINVAL; 3241 } 3242 3243 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3244 rtm_ipv4_policy, extack); 3245 if (err) 3246 return err; 3247 3248 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3249 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3250 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3251 return -EINVAL; 3252 } 3253 3254 for (i = 0; i <= RTA_MAX; i++) { 3255 if (!tb[i]) 3256 continue; 3257 3258 switch (i) { 3259 case RTA_IIF: 3260 case RTA_OIF: 3261 case RTA_SRC: 3262 case RTA_DST: 3263 case RTA_IP_PROTO: 3264 case RTA_SPORT: 3265 case RTA_DPORT: 3266 case RTA_MARK: 3267 case RTA_UID: 3268 break; 3269 default: 3270 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3271 return -EINVAL; 3272 } 3273 } 3274 3275 return 0; 3276 } 3277 3278 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3279 struct netlink_ext_ack *extack) 3280 { 3281 struct net *net = sock_net(in_skb->sk); 3282 struct nlattr *tb[RTA_MAX+1]; 3283 u32 table_id = RT_TABLE_MAIN; 3284 __be16 sport = 0, dport = 0; 3285 struct fib_result res = {}; 3286 u8 ip_proto = IPPROTO_UDP; 3287 struct rtable *rt = NULL; 3288 struct sk_buff *skb; 3289 struct rtmsg *rtm; 3290 struct flowi4 fl4 = {}; 3291 __be32 dst = 0; 3292 __be32 src = 0; 3293 kuid_t uid; 3294 u32 iif; 3295 int err; 3296 int mark; 3297 3298 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3299 if (err < 0) 3300 return err; 3301 3302 rtm = nlmsg_data(nlh); 3303 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3304 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3305 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3306 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3307 if (tb[RTA_UID]) 3308 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3309 else 3310 uid = (iif ? INVALID_UID : current_uid()); 3311 3312 if (tb[RTA_IP_PROTO]) { 3313 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3314 &ip_proto, AF_INET, extack); 3315 if (err) 3316 return err; 3317 } 3318 3319 if (tb[RTA_SPORT]) 3320 sport = nla_get_be16(tb[RTA_SPORT]); 3321 3322 if (tb[RTA_DPORT]) 3323 dport = nla_get_be16(tb[RTA_DPORT]); 3324 3325 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3326 if (!skb) 3327 return -ENOBUFS; 3328 3329 fl4.daddr = dst; 3330 fl4.saddr = src; 3331 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3332 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3333 fl4.flowi4_mark = mark; 3334 fl4.flowi4_uid = uid; 3335 if (sport) 3336 fl4.fl4_sport = sport; 3337 if (dport) 3338 fl4.fl4_dport = dport; 3339 fl4.flowi4_proto = ip_proto; 3340 3341 rcu_read_lock(); 3342 3343 if (iif) { 3344 struct net_device *dev; 3345 3346 dev = dev_get_by_index_rcu(net, iif); 3347 if (!dev) { 3348 err = -ENODEV; 3349 goto errout_rcu; 3350 } 3351 3352 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3353 skb->dev = dev; 3354 skb->mark = mark; 3355 err = ip_route_input_rcu(skb, dst, src, 3356 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3357 &res); 3358 3359 rt = skb_rtable(skb); 3360 if (err == 0 && rt->dst.error) 3361 err = -rt->dst.error; 3362 } else { 3363 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3364 skb->dev = net->loopback_dev; 3365 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3366 err = 0; 3367 if (IS_ERR(rt)) 3368 err = PTR_ERR(rt); 3369 else 3370 skb_dst_set(skb, &rt->dst); 3371 } 3372 3373 if (err) 3374 goto errout_rcu; 3375 3376 if (rtm->rtm_flags & RTM_F_NOTIFY) 3377 rt->rt_flags |= RTCF_NOTIFY; 3378 3379 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3380 table_id = res.table ? res.table->tb_id : 0; 3381 3382 /* reset skb for netlink reply msg */ 3383 skb_trim(skb, 0); 3384 skb_reset_network_header(skb); 3385 skb_reset_transport_header(skb); 3386 skb_reset_mac_header(skb); 3387 3388 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3389 struct fib_rt_info fri; 3390 3391 if (!res.fi) { 3392 err = fib_props[res.type].error; 3393 if (!err) 3394 err = -EHOSTUNREACH; 3395 goto errout_rcu; 3396 } 3397 fri.fi = res.fi; 3398 fri.tb_id = table_id; 3399 fri.dst = res.prefix; 3400 fri.dst_len = res.prefixlen; 3401 fri.dscp = inet_dsfield_to_dscp(fl4.flowi4_tos); 3402 fri.type = rt->rt_type; 3403 fri.offload = 0; 3404 fri.trap = 0; 3405 fri.offload_failed = 0; 3406 if (res.fa_head) { 3407 struct fib_alias *fa; 3408 3409 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3410 u8 slen = 32 - fri.dst_len; 3411 3412 if (fa->fa_slen == slen && 3413 fa->tb_id == fri.tb_id && 3414 fa->fa_dscp == fri.dscp && 3415 fa->fa_info == res.fi && 3416 fa->fa_type == fri.type) { 3417 fri.offload = READ_ONCE(fa->offload); 3418 fri.trap = READ_ONCE(fa->trap); 3419 break; 3420 } 3421 } 3422 } 3423 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3424 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3425 } else { 3426 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3427 NETLINK_CB(in_skb).portid, 3428 nlh->nlmsg_seq, 0); 3429 } 3430 if (err < 0) 3431 goto errout_rcu; 3432 3433 rcu_read_unlock(); 3434 3435 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3436 3437 errout_free: 3438 return err; 3439 errout_rcu: 3440 rcu_read_unlock(); 3441 kfree_skb(skb); 3442 goto errout_free; 3443 } 3444 3445 void ip_rt_multicast_event(struct in_device *in_dev) 3446 { 3447 rt_cache_flush(dev_net(in_dev->dev)); 3448 } 3449 3450 #ifdef CONFIG_SYSCTL 3451 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3452 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3453 static int ip_rt_gc_elasticity __read_mostly = 8; 3454 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3455 3456 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3457 void *buffer, size_t *lenp, loff_t *ppos) 3458 { 3459 struct net *net = (struct net *)__ctl->extra1; 3460 3461 if (write) { 3462 rt_cache_flush(net); 3463 fnhe_genid_bump(net); 3464 return 0; 3465 } 3466 3467 return -EINVAL; 3468 } 3469 3470 static struct ctl_table ipv4_route_table[] = { 3471 { 3472 .procname = "gc_thresh", 3473 .data = &ipv4_dst_ops.gc_thresh, 3474 .maxlen = sizeof(int), 3475 .mode = 0644, 3476 .proc_handler = proc_dointvec, 3477 }, 3478 { 3479 .procname = "max_size", 3480 .data = &ip_rt_max_size, 3481 .maxlen = sizeof(int), 3482 .mode = 0644, 3483 .proc_handler = proc_dointvec, 3484 }, 3485 { 3486 /* Deprecated. Use gc_min_interval_ms */ 3487 3488 .procname = "gc_min_interval", 3489 .data = &ip_rt_gc_min_interval, 3490 .maxlen = sizeof(int), 3491 .mode = 0644, 3492 .proc_handler = proc_dointvec_jiffies, 3493 }, 3494 { 3495 .procname = "gc_min_interval_ms", 3496 .data = &ip_rt_gc_min_interval, 3497 .maxlen = sizeof(int), 3498 .mode = 0644, 3499 .proc_handler = proc_dointvec_ms_jiffies, 3500 }, 3501 { 3502 .procname = "gc_timeout", 3503 .data = &ip_rt_gc_timeout, 3504 .maxlen = sizeof(int), 3505 .mode = 0644, 3506 .proc_handler = proc_dointvec_jiffies, 3507 }, 3508 { 3509 .procname = "gc_interval", 3510 .data = &ip_rt_gc_interval, 3511 .maxlen = sizeof(int), 3512 .mode = 0644, 3513 .proc_handler = proc_dointvec_jiffies, 3514 }, 3515 { 3516 .procname = "redirect_load", 3517 .data = &ip_rt_redirect_load, 3518 .maxlen = sizeof(int), 3519 .mode = 0644, 3520 .proc_handler = proc_dointvec, 3521 }, 3522 { 3523 .procname = "redirect_number", 3524 .data = &ip_rt_redirect_number, 3525 .maxlen = sizeof(int), 3526 .mode = 0644, 3527 .proc_handler = proc_dointvec, 3528 }, 3529 { 3530 .procname = "redirect_silence", 3531 .data = &ip_rt_redirect_silence, 3532 .maxlen = sizeof(int), 3533 .mode = 0644, 3534 .proc_handler = proc_dointvec, 3535 }, 3536 { 3537 .procname = "error_cost", 3538 .data = &ip_rt_error_cost, 3539 .maxlen = sizeof(int), 3540 .mode = 0644, 3541 .proc_handler = proc_dointvec, 3542 }, 3543 { 3544 .procname = "error_burst", 3545 .data = &ip_rt_error_burst, 3546 .maxlen = sizeof(int), 3547 .mode = 0644, 3548 .proc_handler = proc_dointvec, 3549 }, 3550 { 3551 .procname = "gc_elasticity", 3552 .data = &ip_rt_gc_elasticity, 3553 .maxlen = sizeof(int), 3554 .mode = 0644, 3555 .proc_handler = proc_dointvec, 3556 }, 3557 { } 3558 }; 3559 3560 static const char ipv4_route_flush_procname[] = "flush"; 3561 3562 static struct ctl_table ipv4_route_netns_table[] = { 3563 { 3564 .procname = ipv4_route_flush_procname, 3565 .maxlen = sizeof(int), 3566 .mode = 0200, 3567 .proc_handler = ipv4_sysctl_rtcache_flush, 3568 }, 3569 { 3570 .procname = "min_pmtu", 3571 .data = &init_net.ipv4.ip_rt_min_pmtu, 3572 .maxlen = sizeof(int), 3573 .mode = 0644, 3574 .proc_handler = proc_dointvec_minmax, 3575 .extra1 = &ip_min_valid_pmtu, 3576 }, 3577 { 3578 .procname = "mtu_expires", 3579 .data = &init_net.ipv4.ip_rt_mtu_expires, 3580 .maxlen = sizeof(int), 3581 .mode = 0644, 3582 .proc_handler = proc_dointvec_jiffies, 3583 }, 3584 { 3585 .procname = "min_adv_mss", 3586 .data = &init_net.ipv4.ip_rt_min_advmss, 3587 .maxlen = sizeof(int), 3588 .mode = 0644, 3589 .proc_handler = proc_dointvec, 3590 }, 3591 { }, 3592 }; 3593 3594 static __net_init int sysctl_route_net_init(struct net *net) 3595 { 3596 struct ctl_table *tbl; 3597 3598 tbl = ipv4_route_netns_table; 3599 if (!net_eq(net, &init_net)) { 3600 int i; 3601 3602 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3603 if (!tbl) 3604 goto err_dup; 3605 3606 /* Don't export non-whitelisted sysctls to unprivileged users */ 3607 if (net->user_ns != &init_user_ns) { 3608 if (tbl[0].procname != ipv4_route_flush_procname) 3609 tbl[0].procname = NULL; 3610 } 3611 3612 /* Update the variables to point into the current struct net 3613 * except for the first element flush 3614 */ 3615 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3616 tbl[i].data += (void *)net - (void *)&init_net; 3617 } 3618 tbl[0].extra1 = net; 3619 3620 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3621 if (!net->ipv4.route_hdr) 3622 goto err_reg; 3623 return 0; 3624 3625 err_reg: 3626 if (tbl != ipv4_route_netns_table) 3627 kfree(tbl); 3628 err_dup: 3629 return -ENOMEM; 3630 } 3631 3632 static __net_exit void sysctl_route_net_exit(struct net *net) 3633 { 3634 struct ctl_table *tbl; 3635 3636 tbl = net->ipv4.route_hdr->ctl_table_arg; 3637 unregister_net_sysctl_table(net->ipv4.route_hdr); 3638 BUG_ON(tbl == ipv4_route_netns_table); 3639 kfree(tbl); 3640 } 3641 3642 static __net_initdata struct pernet_operations sysctl_route_ops = { 3643 .init = sysctl_route_net_init, 3644 .exit = sysctl_route_net_exit, 3645 }; 3646 #endif 3647 3648 static __net_init int netns_ip_rt_init(struct net *net) 3649 { 3650 /* Set default value for namespaceified sysctls */ 3651 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3652 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3653 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3654 return 0; 3655 } 3656 3657 static struct pernet_operations __net_initdata ip_rt_ops = { 3658 .init = netns_ip_rt_init, 3659 }; 3660 3661 static __net_init int rt_genid_init(struct net *net) 3662 { 3663 atomic_set(&net->ipv4.rt_genid, 0); 3664 atomic_set(&net->fnhe_genid, 0); 3665 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3666 return 0; 3667 } 3668 3669 static __net_initdata struct pernet_operations rt_genid_ops = { 3670 .init = rt_genid_init, 3671 }; 3672 3673 static int __net_init ipv4_inetpeer_init(struct net *net) 3674 { 3675 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3676 3677 if (!bp) 3678 return -ENOMEM; 3679 inet_peer_base_init(bp); 3680 net->ipv4.peers = bp; 3681 return 0; 3682 } 3683 3684 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3685 { 3686 struct inet_peer_base *bp = net->ipv4.peers; 3687 3688 net->ipv4.peers = NULL; 3689 inetpeer_invalidate_tree(bp); 3690 kfree(bp); 3691 } 3692 3693 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3694 .init = ipv4_inetpeer_init, 3695 .exit = ipv4_inetpeer_exit, 3696 }; 3697 3698 #ifdef CONFIG_IP_ROUTE_CLASSID 3699 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3700 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3701 3702 int __init ip_rt_init(void) 3703 { 3704 void *idents_hash; 3705 int cpu; 3706 3707 /* For modern hosts, this will use 2 MB of memory */ 3708 idents_hash = alloc_large_system_hash("IP idents", 3709 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3710 0, 3711 16, /* one bucket per 64 KB */ 3712 HASH_ZERO, 3713 NULL, 3714 &ip_idents_mask, 3715 2048, 3716 256*1024); 3717 3718 ip_idents = idents_hash; 3719 3720 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3721 3722 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3723 3724 for_each_possible_cpu(cpu) { 3725 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3726 3727 INIT_LIST_HEAD(&ul->head); 3728 INIT_LIST_HEAD(&ul->quarantine); 3729 spin_lock_init(&ul->lock); 3730 } 3731 #ifdef CONFIG_IP_ROUTE_CLASSID 3732 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3733 if (!ip_rt_acct) 3734 panic("IP: failed to allocate ip_rt_acct\n"); 3735 #endif 3736 3737 ipv4_dst_ops.kmem_cachep = 3738 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3739 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3740 3741 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3742 3743 if (dst_entries_init(&ipv4_dst_ops) < 0) 3744 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3745 3746 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3747 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3748 3749 ipv4_dst_ops.gc_thresh = ~0; 3750 ip_rt_max_size = INT_MAX; 3751 3752 devinet_init(); 3753 ip_fib_init(); 3754 3755 if (ip_rt_proc_init()) 3756 pr_err("Unable to create route proc files\n"); 3757 #ifdef CONFIG_XFRM 3758 xfrm_init(); 3759 xfrm4_init(); 3760 #endif 3761 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3762 RTNL_FLAG_DOIT_UNLOCKED); 3763 3764 #ifdef CONFIG_SYSCTL 3765 register_pernet_subsys(&sysctl_route_ops); 3766 #endif 3767 register_pernet_subsys(&ip_rt_ops); 3768 register_pernet_subsys(&rt_genid_ops); 3769 register_pernet_subsys(&ipv4_inetpeer_ops); 3770 return 0; 3771 } 3772 3773 #ifdef CONFIG_SYSCTL 3774 /* 3775 * We really need to sanitize the damn ipv4 init order, then all 3776 * this nonsense will go away. 3777 */ 3778 void __init ip_static_sysctl_init(void) 3779 { 3780 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3781 } 3782 #endif 3783