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/flow.h> 88 #include <net/inet_dscp.h> 89 #include <net/net_namespace.h> 90 #include <net/ip.h> 91 #include <net/route.h> 92 #include <net/inetpeer.h> 93 #include <net/sock.h> 94 #include <net/ip_fib.h> 95 #include <net/nexthop.h> 96 #include <net/tcp.h> 97 #include <net/icmp.h> 98 #include <net/xfrm.h> 99 #include <net/lwtunnel.h> 100 #include <net/netevent.h> 101 #include <net/rtnetlink.h> 102 #ifdef CONFIG_SYSCTL 103 #include <linux/sysctl.h> 104 #endif 105 #include <net/secure_seq.h> 106 #include <net/ip_tunnels.h> 107 108 #include "fib_lookup.h" 109 110 #define RT_GC_TIMEOUT (300*HZ) 111 112 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 113 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 114 #define DEFAULT_MIN_ADVMSS 256 115 static int ip_rt_max_size; 116 static int ip_rt_redirect_number __read_mostly = 9; 117 static int ip_rt_redirect_load __read_mostly = HZ / 50; 118 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 119 static int ip_rt_error_cost __read_mostly = HZ; 120 static int ip_rt_error_burst __read_mostly = 5 * HZ; 121 122 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 123 124 /* 125 * Interface to generic destination cache. 126 */ 127 128 INDIRECT_CALLABLE_SCOPE 129 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 130 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 131 INDIRECT_CALLABLE_SCOPE 132 unsigned int ipv4_mtu(const struct dst_entry *dst); 133 static void ipv4_negative_advice(struct sock *sk, 134 struct dst_entry *dst); 135 static void ipv4_link_failure(struct sk_buff *skb); 136 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 137 struct sk_buff *skb, u32 mtu, 138 bool confirm_neigh); 139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 140 struct sk_buff *skb); 141 static void ipv4_dst_destroy(struct dst_entry *dst); 142 143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 144 { 145 WARN_ON(1); 146 return NULL; 147 } 148 149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 150 struct sk_buff *skb, 151 const void *daddr); 152 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 153 154 static struct dst_ops ipv4_dst_ops = { 155 .family = AF_INET, 156 .check = ipv4_dst_check, 157 .default_advmss = ipv4_default_advmss, 158 .mtu = ipv4_mtu, 159 .cow_metrics = ipv4_cow_metrics, 160 .destroy = ipv4_dst_destroy, 161 .negative_advice = ipv4_negative_advice, 162 .link_failure = ipv4_link_failure, 163 .update_pmtu = ip_rt_update_pmtu, 164 .redirect = ip_do_redirect, 165 .local_out = __ip_local_out, 166 .neigh_lookup = ipv4_neigh_lookup, 167 .confirm_neigh = ipv4_confirm_neigh, 168 }; 169 170 #define ECN_OR_COST(class) TC_PRIO_##class 171 172 const __u8 ip_tos2prio[16] = { 173 TC_PRIO_BESTEFFORT, 174 ECN_OR_COST(BESTEFFORT), 175 TC_PRIO_BESTEFFORT, 176 ECN_OR_COST(BESTEFFORT), 177 TC_PRIO_BULK, 178 ECN_OR_COST(BULK), 179 TC_PRIO_BULK, 180 ECN_OR_COST(BULK), 181 TC_PRIO_INTERACTIVE, 182 ECN_OR_COST(INTERACTIVE), 183 TC_PRIO_INTERACTIVE, 184 ECN_OR_COST(INTERACTIVE), 185 TC_PRIO_INTERACTIVE_BULK, 186 ECN_OR_COST(INTERACTIVE_BULK), 187 TC_PRIO_INTERACTIVE_BULK, 188 ECN_OR_COST(INTERACTIVE_BULK) 189 }; 190 EXPORT_SYMBOL(ip_tos2prio); 191 192 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 193 #ifndef CONFIG_PREEMPT_RT 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 #else 196 #define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) 197 #endif 198 199 #ifdef CONFIG_PROC_FS 200 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 201 { 202 if (*pos) 203 return NULL; 204 return SEQ_START_TOKEN; 205 } 206 207 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 208 { 209 ++*pos; 210 return NULL; 211 } 212 213 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 214 { 215 } 216 217 static int rt_cache_seq_show(struct seq_file *seq, void *v) 218 { 219 if (v == SEQ_START_TOKEN) 220 seq_printf(seq, "%-127s\n", 221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 223 "HHUptod\tSpecDst"); 224 return 0; 225 } 226 227 static const struct seq_operations rt_cache_seq_ops = { 228 .start = rt_cache_seq_start, 229 .next = rt_cache_seq_next, 230 .stop = rt_cache_seq_stop, 231 .show = rt_cache_seq_show, 232 }; 233 234 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 235 { 236 int cpu; 237 238 if (*pos == 0) 239 return SEQ_START_TOKEN; 240 241 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 242 if (!cpu_possible(cpu)) 243 continue; 244 *pos = cpu+1; 245 return &per_cpu(rt_cache_stat, cpu); 246 } 247 return NULL; 248 } 249 250 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 251 { 252 int cpu; 253 254 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 255 if (!cpu_possible(cpu)) 256 continue; 257 *pos = cpu+1; 258 return &per_cpu(rt_cache_stat, cpu); 259 } 260 (*pos)++; 261 return NULL; 262 263 } 264 265 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 266 { 267 268 } 269 270 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 271 { 272 struct rt_cache_stat *st = v; 273 274 if (v == SEQ_START_TOKEN) { 275 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"); 276 return 0; 277 } 278 279 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 280 "%08x %08x %08x %08x %08x %08x " 281 "%08x %08x %08x %08x\n", 282 dst_entries_get_slow(&ipv4_dst_ops), 283 0, /* st->in_hit */ 284 st->in_slow_tot, 285 st->in_slow_mc, 286 st->in_no_route, 287 st->in_brd, 288 st->in_martian_dst, 289 st->in_martian_src, 290 291 0, /* st->out_hit */ 292 st->out_slow_tot, 293 st->out_slow_mc, 294 295 0, /* st->gc_total */ 296 0, /* st->gc_ignored */ 297 0, /* st->gc_goal_miss */ 298 0, /* st->gc_dst_overflow */ 299 0, /* st->in_hlist_search */ 300 0 /* st->out_hlist_search */ 301 ); 302 return 0; 303 } 304 305 static const struct seq_operations rt_cpu_seq_ops = { 306 .start = rt_cpu_seq_start, 307 .next = rt_cpu_seq_next, 308 .stop = rt_cpu_seq_stop, 309 .show = rt_cpu_seq_show, 310 }; 311 312 #ifdef CONFIG_IP_ROUTE_CLASSID 313 static int rt_acct_proc_show(struct seq_file *m, void *v) 314 { 315 struct ip_rt_acct *dst, *src; 316 unsigned int i, j; 317 318 dst = kzalloc_objs(struct ip_rt_acct, 256); 319 if (!dst) 320 return -ENOMEM; 321 322 for_each_possible_cpu(i) { 323 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 324 for (j = 0; j < 256; j++) { 325 dst[j].o_bytes += src[j].o_bytes; 326 dst[j].o_packets += src[j].o_packets; 327 dst[j].i_bytes += src[j].i_bytes; 328 dst[j].i_packets += src[j].i_packets; 329 } 330 } 331 332 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 333 kfree(dst); 334 return 0; 335 } 336 #endif 337 338 static int __net_init ip_rt_do_proc_init(struct net *net) 339 { 340 struct proc_dir_entry *pde; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 343 &rt_cache_seq_ops); 344 if (!pde) 345 goto err1; 346 347 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 348 &rt_cpu_seq_ops); 349 if (!pde) 350 goto err2; 351 352 #ifdef CONFIG_IP_ROUTE_CLASSID 353 pde = proc_create_single("rt_acct", 0, net->proc_net, 354 rt_acct_proc_show); 355 if (!pde) 356 goto err3; 357 #endif 358 return 0; 359 360 #ifdef CONFIG_IP_ROUTE_CLASSID 361 err3: 362 remove_proc_entry("rt_cache", net->proc_net_stat); 363 #endif 364 err2: 365 remove_proc_entry("rt_cache", net->proc_net); 366 err1: 367 return -ENOMEM; 368 } 369 370 static void __net_exit ip_rt_do_proc_exit(struct net *net) 371 { 372 remove_proc_entry("rt_cache", net->proc_net_stat); 373 remove_proc_entry("rt_cache", net->proc_net); 374 #ifdef CONFIG_IP_ROUTE_CLASSID 375 remove_proc_entry("rt_acct", net->proc_net); 376 #endif 377 } 378 379 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 380 .init = ip_rt_do_proc_init, 381 .exit = ip_rt_do_proc_exit, 382 }; 383 384 static int __init ip_rt_proc_init(void) 385 { 386 return register_pernet_subsys(&ip_rt_proc_ops); 387 } 388 389 #else 390 static inline int ip_rt_proc_init(void) 391 { 392 return 0; 393 } 394 #endif /* CONFIG_PROC_FS */ 395 396 static inline bool rt_is_expired(const struct rtable *rth) 397 { 398 bool res; 399 400 rcu_read_lock(); 401 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev)); 402 rcu_read_unlock(); 403 404 return res; 405 } 406 407 void rt_cache_flush(struct net *net) 408 { 409 rt_genid_bump_ipv4(net); 410 } 411 412 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 413 struct sk_buff *skb, 414 const void *daddr) 415 { 416 const struct rtable *rt = container_of(dst, struct rtable, dst); 417 struct net_device *dev; 418 struct neighbour *n; 419 420 rcu_read_lock(); 421 dev = dst_dev_rcu(dst); 422 if (likely(rt->rt_gw_family == AF_INET)) { 423 n = ip_neigh_gw4(dev, rt->rt_gw4); 424 } else if (rt->rt_gw_family == AF_INET6) { 425 n = ip_neigh_gw6(dev, &rt->rt_gw6); 426 } else { 427 __be32 pkey; 428 429 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 430 n = ip_neigh_gw4(dev, pkey); 431 } 432 433 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 434 n = NULL; 435 436 rcu_read_unlock(); 437 438 return n; 439 } 440 441 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 442 { 443 const struct rtable *rt = container_of(dst, struct rtable, dst); 444 struct net_device *dev = dst_dev(dst); 445 const __be32 *pkey = daddr; 446 447 if (rt->rt_gw_family == AF_INET) { 448 pkey = (const __be32 *)&rt->rt_gw4; 449 } else if (IS_ENABLED(CONFIG_IPV6) && rt->rt_gw_family == AF_INET6) { 450 return __ipv6_confirm_neigh(dev, &rt->rt_gw6); 451 } else if (!daddr || 452 (rt->rt_flags & 453 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 454 return; 455 } 456 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 457 } 458 459 /* Hash tables of size 2048..262144 depending on RAM size. 460 * Each bucket uses 8 bytes. 461 */ 462 static u32 ip_idents_mask __read_mostly; 463 static atomic_t *ip_idents __read_mostly; 464 static u32 *ip_tstamps __read_mostly; 465 466 /* In order to protect privacy, we add a perturbation to identifiers 467 * if one generator is seldom used. This makes hard for an attacker 468 * to infer how many packets were sent between two points in time. 469 */ 470 static u32 ip_idents_reserve(u32 hash, int segs) 471 { 472 u32 bucket, old, now = (u32)jiffies; 473 atomic_t *p_id; 474 u32 *p_tstamp; 475 u32 delta = 0; 476 477 bucket = hash & ip_idents_mask; 478 p_tstamp = ip_tstamps + bucket; 479 p_id = ip_idents + bucket; 480 old = READ_ONCE(*p_tstamp); 481 482 if (old != now && cmpxchg(p_tstamp, old, now) == old) 483 delta = get_random_u32_below(now - old); 484 485 /* If UBSAN reports an error there, please make sure your compiler 486 * supports -fno-strict-overflow before reporting it that was a bug 487 * in UBSAN, and it has been fixed in GCC-8. 488 */ 489 return atomic_add_return(segs + delta, p_id) - segs; 490 } 491 492 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 493 { 494 u32 hash, id; 495 496 /* Note the following code is not safe, but this is okay. */ 497 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 498 get_random_bytes(&net->ipv4.ip_id_key, 499 sizeof(net->ipv4.ip_id_key)); 500 501 hash = siphash_3u32((__force u32)iph->daddr, 502 (__force u32)iph->saddr, 503 iph->protocol, 504 &net->ipv4.ip_id_key); 505 id = ip_idents_reserve(hash, segs); 506 iph->id = htons(id); 507 } 508 EXPORT_SYMBOL(__ip_select_ident); 509 510 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 511 const struct sock *sk, const struct iphdr *iph, 512 int oif, __u8 tos, u8 prot, u32 mark, 513 int flow_flags) 514 { 515 __u8 scope = RT_SCOPE_UNIVERSE; 516 517 if (sk) { 518 oif = sk->sk_bound_dev_if; 519 mark = READ_ONCE(sk->sk_mark); 520 tos = ip_sock_rt_tos(sk); 521 scope = ip_sock_rt_scope(sk); 522 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 523 sk->sk_protocol; 524 } 525 526 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope, 527 prot, flow_flags, 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 prot = iph->protocol; 538 u32 mark = skb->mark; 539 __u8 tos = iph->tos; 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, READ_ONCE(sk->sk_mark), 555 ip_sock_rt_tos(sk), 556 ip_sock_rt_scope(sk), 557 inet_test_bit(HDRINCL, sk) ? 558 IPPROTO_RAW : sk->sk_protocol, 559 inet_sk_flowi_flags(sk), 560 daddr, inet->inet_saddr, 0, 0, 561 sk_uid(sk)); 562 rcu_read_unlock(); 563 } 564 565 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 566 const struct sk_buff *skb) 567 { 568 if (skb) 569 build_skb_flow_key(fl4, skb, sk); 570 else 571 build_sk_flow_key(fl4, sk); 572 } 573 574 static DEFINE_SPINLOCK(fnhe_lock); 575 576 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 577 { 578 struct rtable *rt; 579 580 rt = rcu_dereference(fnhe->fnhe_rth_input); 581 if (rt) { 582 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 583 dst_dev_put(&rt->dst); 584 dst_release(&rt->dst); 585 } 586 rt = rcu_dereference(fnhe->fnhe_rth_output); 587 if (rt) { 588 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 589 dst_dev_put(&rt->dst); 590 dst_release(&rt->dst); 591 } 592 } 593 594 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 595 { 596 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 597 struct fib_nh_exception *fnhe, *oldest = NULL; 598 599 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 600 fnhe = rcu_dereference_protected(*fnhe_p, 601 lockdep_is_held(&fnhe_lock)); 602 if (!fnhe) 603 break; 604 if (!oldest || 605 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 606 oldest = fnhe; 607 oldest_p = fnhe_p; 608 } 609 } 610 611 /* Clear oldest->fnhe_daddr to prevent this fnhe from being 612 * rebound with new dsts in rt_bind_exception(). 613 */ 614 oldest->fnhe_daddr = 0; 615 fnhe_flush_routes(oldest); 616 *oldest_p = oldest->fnhe_next; 617 kfree_rcu(oldest, rcu); 618 } 619 620 static u32 fnhe_hashfun(__be32 daddr) 621 { 622 static siphash_aligned_key_t fnhe_hash_key; 623 u64 hval; 624 625 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 626 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 627 return hash_64(hval, FNHE_HASH_SHIFT); 628 } 629 630 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 631 { 632 rt->rt_pmtu = fnhe->fnhe_pmtu; 633 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 634 rt->dst.expires = fnhe->fnhe_expires; 635 636 if (fnhe->fnhe_gw) { 637 rt->rt_flags |= RTCF_REDIRECTED; 638 rt->rt_uses_gateway = 1; 639 rt->rt_gw_family = AF_INET; 640 rt->rt_gw4 = fnhe->fnhe_gw; 641 } 642 } 643 644 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 645 __be32 gw, u32 pmtu, bool lock, 646 unsigned long expires) 647 { 648 struct fnhe_hash_bucket *hash; 649 struct fib_nh_exception *fnhe; 650 struct rtable *rt; 651 u32 genid, hval; 652 unsigned int i; 653 int depth; 654 655 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 656 hval = fnhe_hashfun(daddr); 657 658 spin_lock_bh(&fnhe_lock); 659 660 hash = rcu_dereference(nhc->nhc_exceptions); 661 if (!hash) { 662 hash = kzalloc_objs(*hash, FNHE_HASH_SIZE, GFP_ATOMIC); 663 if (!hash) 664 goto out_unlock; 665 rcu_assign_pointer(nhc->nhc_exceptions, hash); 666 } 667 668 hash += hval; 669 670 depth = 0; 671 for (fnhe = rcu_dereference(hash->chain); fnhe; 672 fnhe = rcu_dereference(fnhe->fnhe_next)) { 673 if (fnhe->fnhe_daddr == daddr) 674 break; 675 depth++; 676 } 677 678 if (fnhe) { 679 if (fnhe->fnhe_genid != genid) 680 fnhe->fnhe_genid = genid; 681 if (gw) 682 fnhe->fnhe_gw = gw; 683 if (pmtu) { 684 fnhe->fnhe_pmtu = pmtu; 685 fnhe->fnhe_mtu_locked = lock; 686 } 687 fnhe->fnhe_expires = max(1UL, expires); 688 /* Update all cached dsts too */ 689 rt = rcu_dereference(fnhe->fnhe_rth_input); 690 if (rt) 691 fill_route_from_fnhe(rt, fnhe); 692 rt = rcu_dereference(fnhe->fnhe_rth_output); 693 if (rt) 694 fill_route_from_fnhe(rt, fnhe); 695 } else { 696 /* Randomize max depth to avoid some side channels attacks. */ 697 int max_depth = FNHE_RECLAIM_DEPTH + 698 get_random_u32_below(FNHE_RECLAIM_DEPTH); 699 700 while (depth > max_depth) { 701 fnhe_remove_oldest(hash); 702 depth--; 703 } 704 705 fnhe = kzalloc_obj(*fnhe, GFP_ATOMIC); 706 if (!fnhe) 707 goto out_unlock; 708 709 fnhe->fnhe_next = hash->chain; 710 711 fnhe->fnhe_genid = genid; 712 fnhe->fnhe_daddr = daddr; 713 fnhe->fnhe_gw = gw; 714 fnhe->fnhe_pmtu = pmtu; 715 fnhe->fnhe_mtu_locked = lock; 716 fnhe->fnhe_expires = max(1UL, expires); 717 718 rcu_assign_pointer(hash->chain, fnhe); 719 720 /* Exception created; mark the cached routes for the nexthop 721 * stale, so anyone caching it rechecks if this exception 722 * applies to them. 723 */ 724 rt = rcu_dereference(nhc->nhc_rth_input); 725 if (rt) 726 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 727 728 for_each_possible_cpu(i) { 729 struct rtable __rcu **prt; 730 731 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 732 rt = rcu_dereference(*prt); 733 if (rt) 734 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 735 } 736 } 737 738 fnhe->fnhe_stamp = jiffies; 739 740 out_unlock: 741 spin_unlock_bh(&fnhe_lock); 742 } 743 744 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 745 bool kill_route) 746 { 747 __be32 new_gw = icmp_hdr(skb)->un.gateway; 748 __be32 old_gw = ip_hdr(skb)->saddr; 749 struct net_device *dev = skb->dev; 750 struct in_device *in_dev; 751 struct fib_result res; 752 struct neighbour *n; 753 struct net *net; 754 755 switch (icmp_hdr(skb)->code & 7) { 756 case ICMP_REDIR_NET: 757 case ICMP_REDIR_NETTOS: 758 case ICMP_REDIR_HOST: 759 case ICMP_REDIR_HOSTTOS: 760 break; 761 762 default: 763 return; 764 } 765 766 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 767 return; 768 769 in_dev = __in_dev_get_rcu(dev); 770 if (!in_dev) 771 return; 772 773 net = dev_net(dev); 774 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 775 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 776 ipv4_is_zeronet(new_gw)) 777 goto reject_redirect; 778 779 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 780 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 781 goto reject_redirect; 782 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 783 goto reject_redirect; 784 } else { 785 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 786 goto reject_redirect; 787 } 788 789 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 790 if (!n) 791 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 792 if (!IS_ERR(n)) { 793 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 794 neigh_event_send(n, NULL); 795 } else { 796 if (fib_lookup(net, fl4, &res, 0) == 0) { 797 struct fib_nh_common *nhc; 798 799 fib_select_path(net, &res, fl4, skb); 800 nhc = FIB_RES_NHC(res); 801 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 802 0, false, 803 jiffies + ip_rt_gc_timeout); 804 } 805 if (kill_route) 806 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 807 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 808 } 809 neigh_release(n); 810 } 811 return; 812 813 reject_redirect: 814 #ifdef CONFIG_IP_ROUTE_VERBOSE 815 if (IN_DEV_LOG_MARTIANS(in_dev)) { 816 const struct iphdr *iph = (const struct iphdr *) skb->data; 817 __be32 daddr = iph->daddr; 818 __be32 saddr = iph->saddr; 819 820 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 821 " Advised path = %pI4 -> %pI4\n", 822 &old_gw, dev->name, &new_gw, 823 &saddr, &daddr); 824 } 825 #endif 826 ; 827 } 828 829 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 830 { 831 struct rtable *rt; 832 struct flowi4 fl4; 833 const struct iphdr *iph = (const struct iphdr *) skb->data; 834 struct net *net = dev_net(skb->dev); 835 int oif = skb->dev->ifindex; 836 u8 prot = iph->protocol; 837 u32 mark = skb->mark; 838 __u8 tos = iph->tos; 839 840 rt = dst_rtable(dst); 841 842 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 843 __ip_do_redirect(rt, skb, &fl4, true); 844 } 845 846 static void ipv4_negative_advice(struct sock *sk, 847 struct dst_entry *dst) 848 { 849 struct rtable *rt = dst_rtable(dst); 850 851 if ((READ_ONCE(dst->obsolete) > 0) || 852 (rt->rt_flags & RTCF_REDIRECTED) || 853 READ_ONCE(rt->dst.expires)) 854 sk_dst_reset(sk); 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 net_device *dev; 878 struct inet_peer *peer; 879 int log_martians; 880 struct net *net; 881 int vif; 882 883 rcu_read_lock(); 884 dev = dst_dev_rcu(&rt->dst); 885 in_dev = __in_dev_get_rcu(dev); 886 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 887 rcu_read_unlock(); 888 return; 889 } 890 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 891 vif = l3mdev_master_ifindex_rcu(dev); 892 893 net = dev_net_rcu(dev); 894 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 895 if (!peer) { 896 rcu_read_unlock(); 897 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 898 rt_nexthop(rt, ip_hdr(skb)->daddr)); 899 return; 900 } 901 902 /* No redirected packets during ip_rt_redirect_silence; 903 * reset the algorithm. 904 */ 905 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 906 peer->rate_tokens = 0; 907 peer->n_redirects = 0; 908 } 909 910 /* Too many ignored redirects; do not send anything 911 * set dst.rate_last to the last seen redirected packet. 912 */ 913 if (peer->n_redirects >= ip_rt_redirect_number) { 914 peer->rate_last = jiffies; 915 goto out_unlock; 916 } 917 918 /* Check for load limit; set rate_last to the latest sent 919 * redirect. 920 */ 921 if (peer->n_redirects == 0 || 922 time_after(jiffies, 923 (peer->rate_last + 924 (ip_rt_redirect_load << peer->n_redirects)))) { 925 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 926 927 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 928 peer->rate_last = jiffies; 929 ++peer->n_redirects; 930 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 931 peer->n_redirects == ip_rt_redirect_number) 932 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 933 &ip_hdr(skb)->saddr, inet_iif(skb), 934 &ip_hdr(skb)->daddr, &gw); 935 } 936 out_unlock: 937 rcu_read_unlock(); 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 rcu_read_lock(); 998 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 999 l3mdev_master_ifindex_rcu(skb->dev)); 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 } 1012 rcu_read_unlock(); 1013 1014 if (send) 1015 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1016 1017 out: kfree_skb_reason(skb, reason); 1018 return 0; 1019 } 1020 1021 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1022 { 1023 struct dst_entry *dst = &rt->dst; 1024 struct fib_result res; 1025 bool lock = false; 1026 struct net *net; 1027 u32 old_mtu; 1028 1029 if (ip_mtu_locked(dst)) 1030 return; 1031 1032 old_mtu = ipv4_mtu(dst); 1033 if (old_mtu < mtu) 1034 return; 1035 1036 rcu_read_lock(); 1037 net = dst_dev_net_rcu(dst); 1038 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1039 lock = true; 1040 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1041 } 1042 1043 if (rt->rt_pmtu == mtu && !lock && 1044 time_before(jiffies, READ_ONCE(dst->expires) - 1045 net->ipv4.ip_rt_mtu_expires / 2)) 1046 goto out; 1047 1048 if (fib_lookup(net, fl4, &res, 0) == 0) { 1049 struct fib_nh_common *nhc; 1050 1051 fib_select_path(net, &res, fl4, NULL); 1052 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1053 if (fib_info_num_path(res.fi) > 1) { 1054 int nhsel; 1055 1056 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1057 nhc = fib_info_nhc(res.fi, nhsel); 1058 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1059 jiffies + net->ipv4.ip_rt_mtu_expires); 1060 } 1061 goto out; 1062 } 1063 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1064 nhc = FIB_RES_NHC(res); 1065 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1066 jiffies + net->ipv4.ip_rt_mtu_expires); 1067 } 1068 out: 1069 rcu_read_unlock(); 1070 } 1071 1072 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1073 struct sk_buff *skb, u32 mtu, 1074 bool confirm_neigh) 1075 { 1076 struct rtable *rt = dst_rtable(dst); 1077 struct flowi4 fl4; 1078 1079 ip_rt_build_flow_key(&fl4, sk, skb); 1080 1081 /* Don't make lookup fail for bridged encapsulations */ 1082 if (skb && netif_is_any_bridge_port(skb->dev)) 1083 fl4.flowi4_oif = 0; 1084 1085 __ip_rt_update_pmtu(rt, &fl4, mtu); 1086 } 1087 1088 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1089 int oif, u8 protocol) 1090 { 1091 const struct iphdr *iph = (const struct iphdr *)skb->data; 1092 struct flowi4 fl4; 1093 struct rtable *rt; 1094 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1095 1096 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1097 0); 1098 rt = __ip_route_output_key(net, &fl4); 1099 if (!IS_ERR(rt)) { 1100 __ip_rt_update_pmtu(rt, &fl4, mtu); 1101 ip_rt_put(rt); 1102 } 1103 } 1104 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1105 1106 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1107 { 1108 const struct iphdr *iph = (const struct iphdr *)skb->data; 1109 struct flowi4 fl4; 1110 struct rtable *rt; 1111 1112 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1113 1114 if (!fl4.flowi4_mark) 1115 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1116 1117 rt = __ip_route_output_key(sock_net(sk), &fl4); 1118 if (!IS_ERR(rt)) { 1119 __ip_rt_update_pmtu(rt, &fl4, mtu); 1120 ip_rt_put(rt); 1121 } 1122 } 1123 1124 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1125 { 1126 const struct iphdr *iph = (const struct iphdr *)skb->data; 1127 struct flowi4 fl4; 1128 struct rtable *rt; 1129 struct dst_entry *odst = NULL; 1130 bool new = false; 1131 struct net *net = sock_net(sk); 1132 1133 bh_lock_sock(sk); 1134 1135 if (!ip_sk_accept_pmtu(sk)) 1136 goto out; 1137 1138 odst = sk_dst_get(sk); 1139 1140 if (sock_owned_by_user(sk) || !odst) { 1141 __ipv4_sk_update_pmtu(skb, sk, mtu); 1142 goto out; 1143 } 1144 1145 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1146 1147 rt = dst_rtable(odst); 1148 if (READ_ONCE(odst->obsolete) && !odst->ops->check(odst, 0)) { 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 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1157 1158 if (!dst_check(&rt->dst, 0)) { 1159 if (new) 1160 dst_release(&rt->dst); 1161 1162 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1163 if (IS_ERR(rt)) 1164 goto out; 1165 1166 new = true; 1167 } 1168 1169 if (new) 1170 sk_dst_set(sk, &rt->dst); 1171 1172 out: 1173 bh_unlock_sock(sk); 1174 dst_release(odst); 1175 } 1176 1177 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1178 int oif, u8 protocol) 1179 { 1180 const struct iphdr *iph = (const struct iphdr *)skb->data; 1181 struct flowi4 fl4; 1182 struct rtable *rt; 1183 1184 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1185 rt = __ip_route_output_key(net, &fl4); 1186 if (!IS_ERR(rt)) { 1187 __ip_do_redirect(rt, skb, &fl4, false); 1188 ip_rt_put(rt); 1189 } 1190 } 1191 EXPORT_SYMBOL_GPL(ipv4_redirect); 1192 1193 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1194 { 1195 const struct iphdr *iph = (const struct iphdr *)skb->data; 1196 struct flowi4 fl4; 1197 struct rtable *rt; 1198 struct net *net = sock_net(sk); 1199 1200 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1201 rt = __ip_route_output_key(net, &fl4); 1202 if (!IS_ERR(rt)) { 1203 __ip_do_redirect(rt, skb, &fl4, false); 1204 ip_rt_put(rt); 1205 } 1206 } 1207 1208 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1209 u32 cookie) 1210 { 1211 struct rtable *rt = dst_rtable(dst); 1212 1213 /* All IPV4 dsts are created with ->obsolete set to the value 1214 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1215 * into this function always. 1216 * 1217 * When a PMTU/redirect information update invalidates a route, 1218 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1219 * DST_OBSOLETE_DEAD. 1220 */ 1221 if (READ_ONCE(dst->obsolete) != DST_OBSOLETE_FORCE_CHK || 1222 rt_is_expired(rt)) 1223 return NULL; 1224 return dst; 1225 } 1226 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1227 1228 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1229 { 1230 struct inet_skb_parm parm; 1231 struct net_device *dev; 1232 int res; 1233 1234 /* Recompile ip options since IPCB may not be valid anymore. 1235 * Also check we have a reasonable ipv4 header. 1236 */ 1237 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1238 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1239 return; 1240 1241 memset(&parm, 0, sizeof(parm)); 1242 if (ip_hdr(skb)->ihl > 5) { 1243 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1244 return; 1245 parm.opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1246 1247 rcu_read_lock(); 1248 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1249 res = __ip_options_compile(dev_net(dev), &parm.opt, skb, NULL); 1250 rcu_read_unlock(); 1251 1252 if (res) 1253 return; 1254 } 1255 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &parm); 1256 } 1257 1258 static void ipv4_link_failure(struct sk_buff *skb) 1259 { 1260 struct rtable *rt; 1261 1262 ipv4_send_dest_unreach(skb); 1263 1264 rt = skb_rtable(skb); 1265 if (rt) 1266 dst_set_expires(&rt->dst, 0); 1267 } 1268 1269 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1270 { 1271 pr_debug("%s: %pI4 -> %pI4, %s\n", 1272 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1273 skb->dev ? skb->dev->name : "?"); 1274 kfree_skb(skb); 1275 WARN_ON_ONCE(1); 1276 return 0; 1277 } 1278 1279 /* 1280 * We do not cache source address of outgoing interface, 1281 * because it is used only by IP RR, TS and SRR options, 1282 * so that it out of fast path. 1283 * 1284 * BTW remember: "addr" is allowed to be not aligned 1285 * in IP options! 1286 */ 1287 1288 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1289 { 1290 __be32 src; 1291 1292 rcu_read_lock(); 1293 if (rt_is_output_route(rt)) { 1294 src = ip_hdr(skb)->saddr; 1295 } else { 1296 struct net_device *dev = dst_dev_rcu(&rt->dst); 1297 struct net *net = dev_net_rcu(dev); 1298 struct iphdr *iph = ip_hdr(skb); 1299 struct fib_result res; 1300 struct flowi4 fl4 = { 1301 .daddr = iph->daddr, 1302 .saddr = iph->saddr, 1303 .flowi4_dscp = ip4h_dscp(iph), 1304 .flowi4_oif = dev->ifindex, 1305 .flowi4_iif = skb->dev->ifindex, 1306 .flowi4_mark = skb->mark, 1307 }; 1308 1309 if (fib_lookup(net, &fl4, &res, 0) == 0) 1310 src = fib_result_prefsrc(net, &res); 1311 else 1312 src = inet_select_addr(dev, 1313 rt_nexthop(rt, iph->daddr), 1314 RT_SCOPE_UNIVERSE); 1315 } 1316 rcu_read_unlock(); 1317 1318 memcpy(addr, &src, 4); 1319 } 1320 1321 #ifdef CONFIG_IP_ROUTE_CLASSID 1322 static void set_class_tag(struct rtable *rt, u32 tag) 1323 { 1324 if (!(rt->dst.tclassid & 0xFFFF)) 1325 rt->dst.tclassid |= tag & 0xFFFF; 1326 if (!(rt->dst.tclassid & 0xFFFF0000)) 1327 rt->dst.tclassid |= tag & 0xFFFF0000; 1328 } 1329 #endif 1330 1331 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1332 { 1333 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1334 unsigned int advmss; 1335 struct net *net; 1336 1337 rcu_read_lock(); 1338 net = dst_dev_net_rcu(dst); 1339 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1340 net->ipv4.ip_rt_min_advmss); 1341 rcu_read_unlock(); 1342 1343 return min(advmss, IPV4_MAX_PMTU - header_size); 1344 } 1345 1346 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1347 { 1348 return ip_dst_mtu_maybe_forward(dst, false); 1349 } 1350 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1351 1352 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1353 { 1354 struct fnhe_hash_bucket *hash; 1355 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1356 u32 hval = fnhe_hashfun(daddr); 1357 1358 spin_lock_bh(&fnhe_lock); 1359 1360 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1361 lockdep_is_held(&fnhe_lock)); 1362 hash += hval; 1363 1364 fnhe_p = &hash->chain; 1365 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1366 while (fnhe) { 1367 if (fnhe->fnhe_daddr == daddr) { 1368 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1369 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1370 /* set fnhe_daddr to 0 to ensure it won't bind with 1371 * new dsts in rt_bind_exception(). 1372 */ 1373 fnhe->fnhe_daddr = 0; 1374 fnhe_flush_routes(fnhe); 1375 kfree_rcu(fnhe, rcu); 1376 break; 1377 } 1378 fnhe_p = &fnhe->fnhe_next; 1379 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1380 lockdep_is_held(&fnhe_lock)); 1381 } 1382 1383 spin_unlock_bh(&fnhe_lock); 1384 } 1385 1386 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1387 __be32 daddr) 1388 { 1389 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1390 struct fib_nh_exception *fnhe; 1391 u32 hval; 1392 1393 if (!hash) 1394 return NULL; 1395 1396 hval = fnhe_hashfun(daddr); 1397 1398 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1399 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1400 if (fnhe->fnhe_daddr == daddr) { 1401 if (fnhe->fnhe_expires && 1402 time_after(jiffies, fnhe->fnhe_expires)) { 1403 ip_del_fnhe(nhc, daddr); 1404 break; 1405 } 1406 return fnhe; 1407 } 1408 } 1409 return NULL; 1410 } 1411 1412 /* MTU selection: 1413 * 1. mtu on route is locked - use it 1414 * 2. mtu from nexthop exception 1415 * 3. mtu from egress device 1416 */ 1417 1418 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1419 { 1420 struct fib_nh_common *nhc = res->nhc; 1421 struct net_device *dev = nhc->nhc_dev; 1422 struct fib_info *fi = res->fi; 1423 u32 mtu = 0; 1424 1425 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1426 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1427 mtu = fi->fib_mtu; 1428 1429 if (likely(!mtu)) { 1430 struct fib_nh_exception *fnhe; 1431 1432 fnhe = find_exception(nhc, daddr); 1433 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1434 mtu = fnhe->fnhe_pmtu; 1435 } 1436 1437 if (likely(!mtu)) 1438 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1439 1440 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1441 } 1442 1443 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1444 __be32 daddr, const bool do_cache) 1445 { 1446 bool ret = false; 1447 1448 spin_lock_bh(&fnhe_lock); 1449 1450 if (daddr == fnhe->fnhe_daddr) { 1451 struct rtable __rcu **porig; 1452 struct rtable *orig; 1453 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1454 1455 if (rt_is_input_route(rt)) 1456 porig = &fnhe->fnhe_rth_input; 1457 else 1458 porig = &fnhe->fnhe_rth_output; 1459 orig = rcu_dereference(*porig); 1460 1461 if (fnhe->fnhe_genid != genid) { 1462 fnhe->fnhe_genid = genid; 1463 fnhe->fnhe_gw = 0; 1464 fnhe->fnhe_pmtu = 0; 1465 fnhe->fnhe_expires = 0; 1466 fnhe->fnhe_mtu_locked = false; 1467 fnhe_flush_routes(fnhe); 1468 orig = NULL; 1469 } 1470 fill_route_from_fnhe(rt, fnhe); 1471 if (!rt->rt_gw4) { 1472 rt->rt_gw4 = daddr; 1473 rt->rt_gw_family = AF_INET; 1474 } 1475 1476 if (do_cache) { 1477 dst_hold(&rt->dst); 1478 rcu_assign_pointer(*porig, rt); 1479 if (orig) { 1480 dst_dev_put(&orig->dst); 1481 dst_release(&orig->dst); 1482 } 1483 ret = true; 1484 } 1485 1486 fnhe->fnhe_stamp = jiffies; 1487 } 1488 spin_unlock_bh(&fnhe_lock); 1489 1490 return ret; 1491 } 1492 1493 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1494 { 1495 struct rtable *orig, *prev, **p; 1496 bool ret = true; 1497 1498 if (rt_is_input_route(rt)) { 1499 p = (struct rtable **)&nhc->nhc_rth_input; 1500 } else { 1501 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1502 } 1503 orig = *p; 1504 1505 /* hold dst before doing cmpxchg() to avoid race condition 1506 * on this dst 1507 */ 1508 dst_hold(&rt->dst); 1509 prev = cmpxchg(p, orig, rt); 1510 if (prev == orig) { 1511 if (orig) { 1512 rt_add_uncached_list(orig); 1513 dst_release(&orig->dst); 1514 } 1515 } else { 1516 dst_release(&rt->dst); 1517 ret = false; 1518 } 1519 1520 return ret; 1521 } 1522 1523 struct uncached_list { 1524 spinlock_t lock; 1525 struct list_head head; 1526 }; 1527 1528 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1529 1530 void rt_add_uncached_list(struct rtable *rt) 1531 { 1532 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1533 1534 rt->dst.rt_uncached_list = ul; 1535 1536 spin_lock_bh(&ul->lock); 1537 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1538 spin_unlock_bh(&ul->lock); 1539 } 1540 1541 void rt_del_uncached_list(struct rtable *rt) 1542 { 1543 struct uncached_list *ul = rt->dst.rt_uncached_list; 1544 1545 if (ul) { 1546 spin_lock_bh(&ul->lock); 1547 list_del_init(&rt->dst.rt_uncached); 1548 spin_unlock_bh(&ul->lock); 1549 } 1550 } 1551 1552 static void ipv4_dst_destroy(struct dst_entry *dst) 1553 { 1554 ip_dst_metrics_put(dst); 1555 rt_del_uncached_list(dst_rtable(dst)); 1556 } 1557 1558 void rt_flush_dev(struct net_device *dev) 1559 { 1560 struct rtable *rt, *safe; 1561 int cpu; 1562 1563 for_each_possible_cpu(cpu) { 1564 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1565 1566 if (list_empty(&ul->head)) 1567 continue; 1568 1569 spin_lock_bh(&ul->lock); 1570 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1571 if (rt->dst.dev != dev) 1572 continue; 1573 rcu_assign_pointer(rt->dst.dev_rcu, blackhole_netdev); 1574 netdev_ref_replace(dev, blackhole_netdev, 1575 &rt->dst.dev_tracker, GFP_ATOMIC); 1576 list_del_init(&rt->dst.rt_uncached); 1577 } 1578 spin_unlock_bh(&ul->lock); 1579 } 1580 } 1581 1582 static bool rt_cache_valid(const struct rtable *rt) 1583 { 1584 return rt && 1585 READ_ONCE(rt->dst.obsolete) == DST_OBSOLETE_FORCE_CHK && 1586 !rt_is_expired(rt); 1587 } 1588 1589 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1590 const struct fib_result *res, 1591 struct fib_nh_exception *fnhe, 1592 struct fib_info *fi, u16 type, u32 itag, 1593 const bool do_cache) 1594 { 1595 bool cached = false; 1596 1597 if (fi) { 1598 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1599 1600 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1601 rt->rt_uses_gateway = 1; 1602 rt->rt_gw_family = nhc->nhc_gw_family; 1603 /* only INET and INET6 are supported */ 1604 if (likely(nhc->nhc_gw_family == AF_INET)) 1605 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1606 else 1607 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1608 } 1609 1610 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1611 1612 #ifdef CONFIG_IP_ROUTE_CLASSID 1613 if (nhc->nhc_family == AF_INET) { 1614 struct fib_nh *nh; 1615 1616 nh = container_of(nhc, struct fib_nh, nh_common); 1617 rt->dst.tclassid = nh->nh_tclassid; 1618 } 1619 #endif 1620 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1621 if (unlikely(fnhe)) 1622 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1623 else if (do_cache) 1624 cached = rt_cache_route(nhc, rt); 1625 if (unlikely(!cached)) { 1626 /* Routes we intend to cache in nexthop exception or 1627 * FIB nexthop have the DST_NOCACHE bit clear. 1628 * However, if we are unsuccessful at storing this 1629 * route into the cache we really need to set it. 1630 */ 1631 if (!rt->rt_gw4) { 1632 rt->rt_gw_family = AF_INET; 1633 rt->rt_gw4 = daddr; 1634 } 1635 rt_add_uncached_list(rt); 1636 } 1637 } else 1638 rt_add_uncached_list(rt); 1639 1640 #ifdef CONFIG_IP_ROUTE_CLASSID 1641 #ifdef CONFIG_IP_MULTIPLE_TABLES 1642 set_class_tag(rt, res->tclassid); 1643 #endif 1644 set_class_tag(rt, itag); 1645 #endif 1646 } 1647 1648 struct rtable *rt_dst_alloc(struct net_device *dev, 1649 unsigned int flags, u16 type, 1650 bool noxfrm) 1651 { 1652 struct rtable *rt; 1653 1654 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1655 (noxfrm ? DST_NOXFRM : 0)); 1656 1657 if (rt) { 1658 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1659 rt->rt_flags = flags; 1660 rt->rt_type = type; 1661 rt->rt_is_input = 0; 1662 rt->rt_iif = 0; 1663 rt->rt_pmtu = 0; 1664 rt->rt_mtu_locked = 0; 1665 rt->rt_uses_gateway = 0; 1666 rt->rt_gw_family = 0; 1667 rt->rt_gw4 = 0; 1668 1669 rt->dst.output = ip_output; 1670 if (flags & RTCF_LOCAL) 1671 rt->dst.input = ip_local_deliver; 1672 } 1673 1674 return rt; 1675 } 1676 EXPORT_SYMBOL(rt_dst_alloc); 1677 1678 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1679 { 1680 struct rtable *new_rt; 1681 1682 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1683 rt->dst.flags); 1684 1685 if (new_rt) { 1686 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1687 new_rt->rt_flags = rt->rt_flags; 1688 new_rt->rt_type = rt->rt_type; 1689 new_rt->rt_is_input = rt->rt_is_input; 1690 new_rt->rt_iif = rt->rt_iif; 1691 new_rt->rt_pmtu = rt->rt_pmtu; 1692 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1693 new_rt->rt_gw_family = rt->rt_gw_family; 1694 if (rt->rt_gw_family == AF_INET) 1695 new_rt->rt_gw4 = rt->rt_gw4; 1696 else if (rt->rt_gw_family == AF_INET6) 1697 new_rt->rt_gw6 = rt->rt_gw6; 1698 1699 new_rt->dst.input = READ_ONCE(rt->dst.input); 1700 new_rt->dst.output = READ_ONCE(rt->dst.output); 1701 new_rt->dst.error = rt->dst.error; 1702 new_rt->dst.lastuse = jiffies; 1703 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1704 } 1705 return new_rt; 1706 } 1707 1708 /* called in rcu_read_lock() section */ 1709 enum skb_drop_reason 1710 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1711 dscp_t dscp, struct net_device *dev, 1712 struct in_device *in_dev, u32 *itag) 1713 { 1714 enum skb_drop_reason reason; 1715 1716 /* Primary sanity checks. */ 1717 if (!in_dev) 1718 return SKB_DROP_REASON_NOT_SPECIFIED; 1719 1720 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1721 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1722 1723 if (skb->protocol != htons(ETH_P_IP)) 1724 return SKB_DROP_REASON_INVALID_PROTO; 1725 1726 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1727 return SKB_DROP_REASON_IP_LOCALNET; 1728 1729 if (ipv4_is_zeronet(saddr)) { 1730 if (!ipv4_is_local_multicast(daddr) && 1731 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1732 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1733 } else { 1734 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1735 dev, in_dev, itag); 1736 if (reason) 1737 return reason; 1738 } 1739 return SKB_NOT_DROPPED_YET; 1740 } 1741 1742 /* called in rcu_read_lock() section */ 1743 static enum skb_drop_reason 1744 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1745 dscp_t dscp, struct net_device *dev, int our) 1746 { 1747 struct in_device *in_dev = __in_dev_get_rcu(dev); 1748 unsigned int flags = RTCF_MULTICAST; 1749 enum skb_drop_reason reason; 1750 struct rtable *rth; 1751 u32 itag = 0; 1752 1753 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1754 &itag); 1755 if (reason) 1756 return reason; 1757 1758 if (our) 1759 flags |= RTCF_LOCAL; 1760 1761 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1762 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1763 1764 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1765 false); 1766 if (!rth) 1767 return SKB_DROP_REASON_NOMEM; 1768 1769 #ifdef CONFIG_IP_ROUTE_CLASSID 1770 rth->dst.tclassid = itag; 1771 #endif 1772 rth->dst.output = ip_rt_bug; 1773 rth->rt_is_input= 1; 1774 1775 #ifdef CONFIG_IP_MROUTE 1776 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1777 rth->dst.input = ip_mr_input; 1778 #endif 1779 RT_CACHE_STAT_INC(in_slow_mc); 1780 1781 skb_dst_drop(skb); 1782 skb_dst_set(skb, &rth->dst); 1783 return SKB_NOT_DROPPED_YET; 1784 } 1785 1786 1787 static void ip_handle_martian_source(struct net_device *dev, 1788 struct in_device *in_dev, 1789 struct sk_buff *skb, 1790 __be32 daddr, 1791 __be32 saddr) 1792 { 1793 RT_CACHE_STAT_INC(in_martian_src); 1794 #ifdef CONFIG_IP_ROUTE_VERBOSE 1795 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1796 /* 1797 * RFC1812 recommendation, if source is martian, 1798 * the only hint is MAC header. 1799 */ 1800 pr_warn("martian source (src=%pI4, dst=%pI4, dev=%s)\n", 1801 &saddr, &daddr, dev->name); 1802 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1803 print_hex_dump(KERN_WARNING, "ll header: ", 1804 DUMP_PREFIX_OFFSET, 16, 1, 1805 skb_mac_header(skb), 1806 dev->hard_header_len, false); 1807 } 1808 } 1809 #endif 1810 } 1811 1812 /* called in rcu_read_lock() section */ 1813 static enum skb_drop_reason 1814 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1815 struct in_device *in_dev, __be32 daddr, 1816 __be32 saddr, dscp_t dscp) 1817 { 1818 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1819 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1820 struct net_device *dev = nhc->nhc_dev; 1821 struct fib_nh_exception *fnhe; 1822 struct rtable *rth; 1823 int err; 1824 struct in_device *out_dev; 1825 bool do_cache; 1826 u32 itag = 0; 1827 1828 /* get a working reference to the output device */ 1829 out_dev = __in_dev_get_rcu(dev); 1830 if (!out_dev) { 1831 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1832 return reason; 1833 } 1834 1835 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1836 in_dev->dev, in_dev, &itag); 1837 if (err < 0) { 1838 reason = -err; 1839 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1840 saddr); 1841 1842 goto cleanup; 1843 } 1844 1845 do_cache = res->fi && !itag; 1846 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1847 skb->protocol == htons(ETH_P_IP)) { 1848 __be32 gw; 1849 1850 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1851 if (IN_DEV_SHARED_MEDIA(out_dev) || 1852 inet_addr_onlink(out_dev, saddr, gw)) 1853 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1854 } 1855 1856 if (skb->protocol != htons(ETH_P_IP)) { 1857 /* Not IP (i.e. ARP). Do not create route, if it is 1858 * invalid for proxy arp. DNAT routes are always valid. 1859 * 1860 * Proxy arp feature have been extended to allow, ARP 1861 * replies back to the same interface, to support 1862 * Private VLAN switch technologies. See arp.c. 1863 */ 1864 if (out_dev == in_dev && 1865 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1866 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1867 goto cleanup; 1868 } 1869 } 1870 1871 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1872 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1873 1874 fnhe = find_exception(nhc, daddr); 1875 if (do_cache) { 1876 if (fnhe) 1877 rth = rcu_dereference(fnhe->fnhe_rth_input); 1878 else 1879 rth = rcu_dereference(nhc->nhc_rth_input); 1880 if (rt_cache_valid(rth)) { 1881 skb_dst_set_noref(skb, &rth->dst); 1882 goto out; 1883 } 1884 } 1885 1886 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1887 IN_DEV_ORCONF(out_dev, NOXFRM)); 1888 if (!rth) { 1889 reason = SKB_DROP_REASON_NOMEM; 1890 goto cleanup; 1891 } 1892 1893 rth->rt_is_input = 1; 1894 RT_CACHE_STAT_INC(in_slow_tot); 1895 1896 rth->dst.input = ip_forward; 1897 1898 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1899 do_cache); 1900 lwtunnel_set_redirect(&rth->dst); 1901 skb_dst_set(skb, &rth->dst); 1902 out: 1903 reason = SKB_NOT_DROPPED_YET; 1904 cleanup: 1905 return reason; 1906 } 1907 1908 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1909 /* To make ICMP packets follow the right flow, the multipath hash is 1910 * calculated from the inner IP addresses. 1911 */ 1912 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1913 struct flow_keys *hash_keys) 1914 { 1915 const struct iphdr *outer_iph = ip_hdr(skb); 1916 const struct iphdr *key_iph = outer_iph; 1917 const struct iphdr *inner_iph; 1918 const struct icmphdr *icmph; 1919 struct iphdr _inner_iph; 1920 struct icmphdr _icmph; 1921 1922 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1923 goto out; 1924 1925 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1926 goto out; 1927 1928 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1929 &_icmph); 1930 if (!icmph) 1931 goto out; 1932 1933 if (!icmp_is_err(icmph->type)) 1934 goto out; 1935 1936 inner_iph = skb_header_pointer(skb, 1937 outer_iph->ihl * 4 + sizeof(_icmph), 1938 sizeof(_inner_iph), &_inner_iph); 1939 if (!inner_iph) 1940 goto out; 1941 1942 key_iph = inner_iph; 1943 out: 1944 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1945 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1946 } 1947 1948 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1949 const struct sk_buff *skb, 1950 bool *p_has_inner) 1951 { 1952 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1953 struct flow_keys keys, hash_keys; 1954 1955 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1956 return 0; 1957 1958 memset(&hash_keys, 0, sizeof(hash_keys)); 1959 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1960 1961 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1962 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1963 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1964 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1965 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1966 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1967 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1968 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1969 hash_keys.ports.src = keys.ports.src; 1970 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1971 hash_keys.ports.dst = keys.ports.dst; 1972 1973 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1974 return fib_multipath_hash_from_keys(net, &hash_keys); 1975 } 1976 1977 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1978 const struct sk_buff *skb, 1979 bool has_inner) 1980 { 1981 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1982 struct flow_keys keys, hash_keys; 1983 1984 /* We assume the packet carries an encapsulation, but if none was 1985 * encountered during dissection of the outer flow, then there is no 1986 * point in calling the flow dissector again. 1987 */ 1988 if (!has_inner) 1989 return 0; 1990 1991 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1992 return 0; 1993 1994 memset(&hash_keys, 0, sizeof(hash_keys)); 1995 skb_flow_dissect_flow_keys(skb, &keys, 0); 1996 1997 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1998 return 0; 1999 2000 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2001 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2002 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2003 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2004 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2005 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2006 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2007 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2008 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2009 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2010 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2011 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2012 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2013 hash_keys.tags.flow_label = keys.tags.flow_label; 2014 } 2015 2016 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2017 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2018 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2019 hash_keys.ports.src = keys.ports.src; 2020 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2021 hash_keys.ports.dst = keys.ports.dst; 2022 2023 return fib_multipath_hash_from_keys(net, &hash_keys); 2024 } 2025 2026 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2027 const struct sk_buff *skb) 2028 { 2029 u32 mhash, mhash_inner; 2030 bool has_inner = true; 2031 2032 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2033 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2034 2035 return jhash_2words(mhash, mhash_inner, 0); 2036 } 2037 2038 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2039 const struct flowi4 *fl4) 2040 { 2041 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2042 struct flow_keys hash_keys; 2043 2044 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2045 return 0; 2046 2047 memset(&hash_keys, 0, sizeof(hash_keys)); 2048 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2049 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2050 hash_keys.addrs.v4addrs.src = fl4->saddr; 2051 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2052 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2053 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2054 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2055 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2056 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2057 hash_keys.ports.src = (__force __be16)get_random_u16(); 2058 else 2059 hash_keys.ports.src = fl4->fl4_sport; 2060 } 2061 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2062 hash_keys.ports.dst = fl4->fl4_dport; 2063 2064 return fib_multipath_hash_from_keys(net, &hash_keys); 2065 } 2066 2067 /* if skb is set it will be used and fl4 can be NULL */ 2068 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2069 const struct sk_buff *skb, struct flow_keys *flkeys) 2070 { 2071 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2072 struct flow_keys hash_keys; 2073 u32 mhash = 0; 2074 2075 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2076 case 0: 2077 memset(&hash_keys, 0, sizeof(hash_keys)); 2078 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2079 if (skb) { 2080 ip_multipath_l3_keys(skb, &hash_keys); 2081 } else { 2082 hash_keys.addrs.v4addrs.src = fl4->saddr; 2083 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2084 } 2085 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2086 break; 2087 case 1: 2088 /* skb is currently provided only when forwarding */ 2089 if (skb) { 2090 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2091 struct flow_keys keys; 2092 2093 /* short-circuit if we already have L4 hash present */ 2094 if (skb->l4_hash) 2095 return skb_get_hash_raw(skb) >> 1; 2096 2097 memset(&hash_keys, 0, sizeof(hash_keys)); 2098 2099 if (!flkeys) { 2100 skb_flow_dissect_flow_keys(skb, &keys, flag); 2101 flkeys = &keys; 2102 } 2103 2104 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2105 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2106 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2107 hash_keys.ports.src = flkeys->ports.src; 2108 hash_keys.ports.dst = flkeys->ports.dst; 2109 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2110 } else { 2111 memset(&hash_keys, 0, sizeof(hash_keys)); 2112 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2113 hash_keys.addrs.v4addrs.src = fl4->saddr; 2114 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2115 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2116 hash_keys.ports.src = (__force __be16)get_random_u16(); 2117 else 2118 hash_keys.ports.src = fl4->fl4_sport; 2119 hash_keys.ports.dst = fl4->fl4_dport; 2120 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2121 } 2122 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2123 break; 2124 case 2: 2125 memset(&hash_keys, 0, sizeof(hash_keys)); 2126 /* skb is currently provided only when forwarding */ 2127 if (skb) { 2128 struct flow_keys keys; 2129 2130 skb_flow_dissect_flow_keys(skb, &keys, 0); 2131 /* Inner can be v4 or v6 */ 2132 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2133 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2134 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2135 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2136 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2137 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2138 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2139 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2140 hash_keys.tags.flow_label = keys.tags.flow_label; 2141 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2142 } else { 2143 /* Same as case 0 */ 2144 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2145 ip_multipath_l3_keys(skb, &hash_keys); 2146 } 2147 } else { 2148 /* Same as case 0 */ 2149 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2150 hash_keys.addrs.v4addrs.src = fl4->saddr; 2151 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2152 } 2153 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2154 break; 2155 case 3: 2156 if (skb) 2157 mhash = fib_multipath_custom_hash_skb(net, skb); 2158 else 2159 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2160 break; 2161 } 2162 2163 if (multipath_hash) 2164 mhash = jhash_2words(mhash, multipath_hash, 0); 2165 2166 return mhash >> 1; 2167 } 2168 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2169 2170 static enum skb_drop_reason 2171 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2172 struct in_device *in_dev, __be32 daddr, 2173 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2174 { 2175 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2176 if (res->fi && fib_info_num_path(res->fi) > 1) { 2177 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2178 2179 fib_select_multipath(res, h, NULL); 2180 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2181 } 2182 #endif 2183 2184 /* create a routing cache entry */ 2185 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2186 } 2187 2188 /* Implements all the saddr-related checks as ip_route_input_slow(), 2189 * assuming daddr is valid and the destination is not a local broadcast one. 2190 * Uses the provided hint instead of performing a route lookup. 2191 */ 2192 enum skb_drop_reason 2193 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2194 dscp_t dscp, struct net_device *dev, 2195 const struct sk_buff *hint) 2196 { 2197 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2198 struct in_device *in_dev = __in_dev_get_rcu(dev); 2199 struct rtable *rt = skb_rtable(hint); 2200 struct net *net = dev_net(dev); 2201 u32 tag = 0; 2202 2203 if (!in_dev) 2204 return reason; 2205 2206 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2207 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2208 goto martian_source; 2209 } 2210 2211 if (ipv4_is_zeronet(saddr)) { 2212 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2213 goto martian_source; 2214 } 2215 2216 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2217 reason = SKB_DROP_REASON_IP_LOCALNET; 2218 goto martian_source; 2219 } 2220 2221 if (!(rt->rt_flags & RTCF_LOCAL)) 2222 goto skip_validate_source; 2223 2224 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2225 in_dev, &tag); 2226 if (reason) 2227 goto martian_source; 2228 2229 skip_validate_source: 2230 skb_dst_copy(skb, hint); 2231 return SKB_NOT_DROPPED_YET; 2232 2233 martian_source: 2234 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2235 return reason; 2236 } 2237 2238 /* get device for dst_alloc with local routes */ 2239 static struct net_device *ip_rt_get_dev(struct net *net, 2240 const struct fib_result *res) 2241 { 2242 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2243 struct net_device *dev = NULL; 2244 2245 if (nhc) 2246 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2247 2248 return dev ? : net->loopback_dev; 2249 } 2250 2251 /* 2252 * NOTE. We drop all the packets that has local source 2253 * addresses, because every properly looped back packet 2254 * must have correct destination already attached by output routine. 2255 * Changes in the enforced policies must be applied also to 2256 * ip_route_use_hint(). 2257 * 2258 * Such approach solves two big problems: 2259 * 1. Not simplex devices are handled properly. 2260 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2261 * called with rcu_read_lock() 2262 */ 2263 2264 static enum skb_drop_reason 2265 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2266 dscp_t dscp, struct net_device *dev, 2267 struct fib_result *res) 2268 { 2269 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2270 struct in_device *in_dev = __in_dev_get_rcu(dev); 2271 struct flow_keys *flkeys = NULL, _flkeys; 2272 struct net *net = dev_net(dev); 2273 struct ip_tunnel_info *tun_info; 2274 int err = -EINVAL; 2275 unsigned int flags = 0; 2276 u32 itag = 0; 2277 struct rtable *rth; 2278 struct flowi4 fl4; 2279 bool do_cache = true; 2280 2281 /* IP on this device is disabled. */ 2282 2283 if (!in_dev) 2284 goto out; 2285 2286 /* Check for the most weird martians, which can be not detected 2287 * by fib_lookup. 2288 */ 2289 2290 tun_info = skb_tunnel_info(skb); 2291 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2292 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2293 else 2294 fl4.flowi4_tun_key.tun_id = 0; 2295 skb_dst_drop(skb); 2296 2297 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2298 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2299 goto martian_source; 2300 } 2301 2302 res->fi = NULL; 2303 res->table = NULL; 2304 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2305 goto brd_input; 2306 2307 /* Accept zero addresses only to limited broadcast; 2308 * I even do not know to fix it or not. Waiting for complains :-) 2309 */ 2310 if (ipv4_is_zeronet(saddr)) { 2311 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2312 goto martian_source; 2313 } 2314 2315 if (ipv4_is_zeronet(daddr)) { 2316 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2317 goto martian_destination; 2318 } 2319 2320 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2321 * and call it once if daddr or/and saddr are loopback addresses 2322 */ 2323 if (ipv4_is_loopback(daddr)) { 2324 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2325 reason = SKB_DROP_REASON_IP_LOCALNET; 2326 goto martian_destination; 2327 } 2328 } else if (ipv4_is_loopback(saddr)) { 2329 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2330 reason = SKB_DROP_REASON_IP_LOCALNET; 2331 goto martian_source; 2332 } 2333 } 2334 2335 /* 2336 * Now we are ready to route packet. 2337 */ 2338 fl4.flowi4_l3mdev = 0; 2339 fl4.flowi4_oif = 0; 2340 fl4.flowi4_iif = dev->ifindex; 2341 fl4.flowi4_mark = skb->mark; 2342 fl4.flowi4_dscp = dscp; 2343 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2344 fl4.flowi4_flags = 0; 2345 fl4.daddr = daddr; 2346 fl4.saddr = saddr; 2347 fl4.flowi4_uid = sock_net_uid(net, NULL); 2348 fl4.flowi4_multipath_hash = 0; 2349 2350 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2351 flkeys = &_flkeys; 2352 } else { 2353 fl4.flowi4_proto = 0; 2354 fl4.fl4_sport = 0; 2355 fl4.fl4_dport = 0; 2356 } 2357 2358 err = fib_lookup(net, &fl4, res, 0); 2359 if (err != 0) { 2360 if (!IN_DEV_FORWARD(in_dev)) 2361 err = -EHOSTUNREACH; 2362 goto no_route; 2363 } 2364 2365 if (res->type == RTN_BROADCAST) { 2366 if (IN_DEV_BFORWARD(in_dev)) 2367 goto make_route; 2368 /* not do cache if bc_forwarding is enabled */ 2369 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2370 do_cache = false; 2371 goto brd_input; 2372 } 2373 2374 err = -EINVAL; 2375 if (res->type == RTN_LOCAL) { 2376 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2377 0, dev, in_dev, &itag); 2378 if (reason) 2379 goto martian_source; 2380 goto local_input; 2381 } 2382 2383 if (!IN_DEV_FORWARD(in_dev)) { 2384 err = -EHOSTUNREACH; 2385 goto no_route; 2386 } 2387 if (res->type != RTN_UNICAST) { 2388 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2389 goto martian_destination; 2390 } 2391 2392 make_route: 2393 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2394 flkeys); 2395 2396 out: 2397 return reason; 2398 2399 brd_input: 2400 if (skb->protocol != htons(ETH_P_IP)) { 2401 reason = SKB_DROP_REASON_INVALID_PROTO; 2402 goto out; 2403 } 2404 2405 if (!ipv4_is_zeronet(saddr)) { 2406 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2407 dev, in_dev, &itag); 2408 if (reason) 2409 goto martian_source; 2410 } 2411 flags |= RTCF_BROADCAST; 2412 res->type = RTN_BROADCAST; 2413 RT_CACHE_STAT_INC(in_brd); 2414 2415 local_input: 2416 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2417 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2418 2419 do_cache &= res->fi && !itag; 2420 if (do_cache) { 2421 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2422 2423 rth = rcu_dereference(nhc->nhc_rth_input); 2424 if (rt_cache_valid(rth)) { 2425 skb_dst_set_noref(skb, &rth->dst); 2426 reason = SKB_NOT_DROPPED_YET; 2427 goto out; 2428 } 2429 } 2430 2431 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2432 flags | RTCF_LOCAL, res->type, false); 2433 if (!rth) 2434 goto e_nobufs; 2435 2436 rth->dst.output= ip_rt_bug; 2437 #ifdef CONFIG_IP_ROUTE_CLASSID 2438 rth->dst.tclassid = itag; 2439 #endif 2440 rth->rt_is_input = 1; 2441 2442 RT_CACHE_STAT_INC(in_slow_tot); 2443 if (res->type == RTN_UNREACHABLE) { 2444 rth->dst.input= ip_error; 2445 rth->dst.error= -err; 2446 rth->rt_flags &= ~RTCF_LOCAL; 2447 } 2448 2449 if (do_cache) { 2450 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2451 2452 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2453 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2454 WARN_ON(rth->dst.input == lwtunnel_input); 2455 rth->dst.lwtstate->orig_input = rth->dst.input; 2456 rth->dst.input = lwtunnel_input; 2457 } 2458 2459 if (unlikely(!rt_cache_route(nhc, rth))) 2460 rt_add_uncached_list(rth); 2461 } 2462 skb_dst_set(skb, &rth->dst); 2463 reason = SKB_NOT_DROPPED_YET; 2464 goto out; 2465 2466 no_route: 2467 RT_CACHE_STAT_INC(in_no_route); 2468 res->type = RTN_UNREACHABLE; 2469 res->fi = NULL; 2470 res->table = NULL; 2471 goto local_input; 2472 2473 /* 2474 * Do not cache martian addresses: they should be logged (RFC1812) 2475 */ 2476 martian_destination: 2477 RT_CACHE_STAT_INC(in_martian_dst); 2478 #ifdef CONFIG_IP_ROUTE_VERBOSE 2479 if (IN_DEV_LOG_MARTIANS(in_dev)) 2480 net_warn_ratelimited("martian destination (src=%pI4, dst=%pI4, dev=%s)\n", 2481 &saddr, &daddr, dev->name); 2482 #endif 2483 goto out; 2484 2485 e_nobufs: 2486 reason = SKB_DROP_REASON_NOMEM; 2487 goto out; 2488 2489 martian_source: 2490 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2491 goto out; 2492 } 2493 2494 /* called with rcu_read_lock held */ 2495 static enum skb_drop_reason 2496 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2497 dscp_t dscp, struct net_device *dev, 2498 struct fib_result *res) 2499 { 2500 /* Multicast recognition logic is moved from route cache to here. 2501 * The problem was that too many Ethernet cards have broken/missing 2502 * hardware multicast filters :-( As result the host on multicasting 2503 * network acquires a lot of useless route cache entries, sort of 2504 * SDR messages from all the world. Now we try to get rid of them. 2505 * Really, provided software IP multicast filter is organized 2506 * reasonably (at least, hashed), it does not result in a slowdown 2507 * comparing with route cache reject entries. 2508 * Note, that multicast routers are not affected, because 2509 * route cache entry is created eventually. 2510 */ 2511 if (ipv4_is_multicast(daddr)) { 2512 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2513 struct in_device *in_dev = __in_dev_get_rcu(dev); 2514 int our = 0; 2515 2516 if (!in_dev) 2517 return reason; 2518 2519 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2520 ip_hdr(skb)->protocol); 2521 2522 /* check l3 master if no match yet */ 2523 if (!our && netif_is_l3_slave(dev)) { 2524 struct in_device *l3_in_dev; 2525 2526 l3_in_dev = __in_dev_get_rcu(skb->dev); 2527 if (l3_in_dev) 2528 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2529 ip_hdr(skb)->protocol); 2530 } 2531 2532 if (our 2533 #ifdef CONFIG_IP_MROUTE 2534 || 2535 (!ipv4_is_local_multicast(daddr) && 2536 IN_DEV_MFORWARD(in_dev)) 2537 #endif 2538 ) { 2539 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2540 dev, our); 2541 } 2542 return reason; 2543 } 2544 2545 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2546 } 2547 2548 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2549 __be32 saddr, dscp_t dscp, 2550 struct net_device *dev) 2551 { 2552 enum skb_drop_reason reason; 2553 struct fib_result res; 2554 2555 rcu_read_lock(); 2556 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2557 rcu_read_unlock(); 2558 2559 return reason; 2560 } 2561 EXPORT_SYMBOL(ip_route_input_noref); 2562 2563 /* called with rcu_read_lock() */ 2564 static struct rtable *__mkroute_output(const struct fib_result *res, 2565 const struct flowi4 *fl4, int orig_oif, 2566 struct net_device *dev_out, 2567 unsigned int flags) 2568 { 2569 struct fib_info *fi = res->fi; 2570 struct fib_nh_exception *fnhe; 2571 struct in_device *in_dev; 2572 u16 type = res->type; 2573 struct rtable *rth; 2574 bool do_cache; 2575 2576 in_dev = __in_dev_get_rcu(dev_out); 2577 if (!in_dev) 2578 return ERR_PTR(-EINVAL); 2579 2580 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2581 if (ipv4_is_loopback(fl4->saddr) && 2582 !(dev_out->flags & IFF_LOOPBACK) && 2583 !netif_is_l3_master(dev_out)) 2584 return ERR_PTR(-EINVAL); 2585 2586 if (ipv4_is_lbcast(fl4->daddr)) { 2587 type = RTN_BROADCAST; 2588 2589 /* reset fi to prevent gateway resolution */ 2590 fi = NULL; 2591 } else if (ipv4_is_multicast(fl4->daddr)) { 2592 type = RTN_MULTICAST; 2593 } else if (ipv4_is_zeronet(fl4->daddr)) { 2594 return ERR_PTR(-EINVAL); 2595 } 2596 2597 if (dev_out->flags & IFF_LOOPBACK) 2598 flags |= RTCF_LOCAL; 2599 2600 do_cache = true; 2601 if (type == RTN_BROADCAST) { 2602 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2603 } else if (type == RTN_MULTICAST) { 2604 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2605 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2606 fl4->flowi4_proto)) 2607 flags &= ~RTCF_LOCAL; 2608 else 2609 do_cache = false; 2610 /* If multicast route do not exist use 2611 * default one, but do not gateway in this case. 2612 * Yes, it is hack. 2613 */ 2614 if (fi && res->prefixlen < 4) 2615 fi = NULL; 2616 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2617 (orig_oif != dev_out->ifindex)) { 2618 /* For local routes that require a particular output interface 2619 * we do not want to cache the result. Caching the result 2620 * causes incorrect behaviour when there are multiple source 2621 * addresses on the interface, the end result being that if the 2622 * intended recipient is waiting on that interface for the 2623 * packet he won't receive it because it will be delivered on 2624 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2625 * be set to the loopback interface as well. 2626 */ 2627 do_cache = false; 2628 } 2629 2630 fnhe = NULL; 2631 do_cache &= fi != NULL; 2632 if (fi) { 2633 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2634 struct rtable __rcu **prth; 2635 2636 fnhe = find_exception(nhc, fl4->daddr); 2637 if (!do_cache) 2638 goto add; 2639 if (fnhe) { 2640 prth = &fnhe->fnhe_rth_output; 2641 } else { 2642 if (unlikely(fl4->flowi4_flags & 2643 FLOWI_FLAG_KNOWN_NH && 2644 !(nhc->nhc_gw_family && 2645 nhc->nhc_scope == RT_SCOPE_LINK))) { 2646 do_cache = false; 2647 goto add; 2648 } 2649 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2650 } 2651 rth = rcu_dereference(*prth); 2652 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2653 return rth; 2654 } 2655 2656 add: 2657 rth = rt_dst_alloc(dev_out, flags, type, 2658 IN_DEV_ORCONF(in_dev, NOXFRM)); 2659 if (!rth) 2660 return ERR_PTR(-ENOBUFS); 2661 2662 rth->rt_iif = orig_oif; 2663 2664 RT_CACHE_STAT_INC(out_slow_tot); 2665 2666 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2667 if (flags & RTCF_LOCAL && 2668 !(dev_out->flags & IFF_LOOPBACK)) { 2669 rth->dst.output = ip_mc_output; 2670 RT_CACHE_STAT_INC(out_slow_mc); 2671 } 2672 #ifdef CONFIG_IP_MROUTE 2673 if (type == RTN_MULTICAST) { 2674 if (IN_DEV_MFORWARD(in_dev) && 2675 !ipv4_is_local_multicast(fl4->daddr)) { 2676 rth->dst.input = ip_mr_input; 2677 rth->dst.output = ip_mr_output; 2678 } 2679 } 2680 #endif 2681 } 2682 2683 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2684 lwtunnel_set_redirect(&rth->dst); 2685 2686 return rth; 2687 } 2688 2689 /* 2690 * Major route resolver routine. 2691 */ 2692 2693 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2694 const struct sk_buff *skb) 2695 { 2696 struct fib_result res = { 2697 .type = RTN_UNSPEC, 2698 .fi = NULL, 2699 .table = NULL, 2700 .tclassid = 0, 2701 }; 2702 struct rtable *rth; 2703 2704 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2705 2706 rcu_read_lock(); 2707 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2708 rcu_read_unlock(); 2709 2710 return rth; 2711 } 2712 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2713 2714 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2715 struct fib_result *res, 2716 const struct sk_buff *skb) 2717 { 2718 struct net_device *dev_out = NULL; 2719 int orig_oif = fl4->flowi4_oif; 2720 unsigned int flags = 0; 2721 struct rtable *rth; 2722 int err; 2723 2724 if (fl4->saddr) { 2725 if (ipv4_is_multicast(fl4->saddr) || 2726 ipv4_is_lbcast(fl4->saddr)) { 2727 rth = ERR_PTR(-EINVAL); 2728 goto out; 2729 } 2730 2731 rth = ERR_PTR(-ENETUNREACH); 2732 2733 /* I removed check for oif == dev_out->oif here. 2734 * It was wrong for two reasons: 2735 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2736 * is assigned to multiple interfaces. 2737 * 2. Moreover, we are allowed to send packets with saddr 2738 * of another iface. --ANK 2739 */ 2740 2741 if (fl4->flowi4_oif == 0 && 2742 (ipv4_is_multicast(fl4->daddr) || 2743 ipv4_is_lbcast(fl4->daddr))) { 2744 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2745 dev_out = __ip_dev_find(net, fl4->saddr, false); 2746 if (!dev_out) 2747 goto out; 2748 2749 /* Special hack: user can direct multicasts 2750 * and limited broadcast via necessary interface 2751 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2752 * This hack is not just for fun, it allows 2753 * vic,vat and friends to work. 2754 * They bind socket to loopback, set ttl to zero 2755 * and expect that it will work. 2756 * From the viewpoint of routing cache they are broken, 2757 * because we are not allowed to build multicast path 2758 * with loopback source addr (look, routing cache 2759 * cannot know, that ttl is zero, so that packet 2760 * will not leave this host and route is valid). 2761 * Luckily, this hack is good workaround. 2762 */ 2763 2764 fl4->flowi4_oif = dev_out->ifindex; 2765 goto make_route; 2766 } 2767 2768 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2769 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2770 if (!__ip_dev_find(net, fl4->saddr, false)) 2771 goto out; 2772 } 2773 } 2774 2775 2776 if (fl4->flowi4_oif) { 2777 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2778 rth = ERR_PTR(-ENODEV); 2779 if (!dev_out) 2780 goto out; 2781 2782 /* RACE: Check return value of inet_select_addr instead. */ 2783 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2784 rth = ERR_PTR(-ENETUNREACH); 2785 goto out; 2786 } 2787 if (ipv4_is_local_multicast(fl4->daddr) || 2788 ipv4_is_lbcast(fl4->daddr) || 2789 fl4->flowi4_proto == IPPROTO_IGMP) { 2790 if (!fl4->saddr) 2791 fl4->saddr = inet_select_addr(dev_out, 0, 2792 RT_SCOPE_LINK); 2793 goto make_route; 2794 } 2795 if (!fl4->saddr) { 2796 if (ipv4_is_multicast(fl4->daddr)) 2797 fl4->saddr = inet_select_addr(dev_out, 0, 2798 fl4->flowi4_scope); 2799 else if (!fl4->daddr) 2800 fl4->saddr = inet_select_addr(dev_out, 0, 2801 RT_SCOPE_HOST); 2802 } 2803 } 2804 2805 if (!fl4->daddr) { 2806 fl4->daddr = fl4->saddr; 2807 if (!fl4->daddr) 2808 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2809 dev_out = net->loopback_dev; 2810 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2811 res->type = RTN_LOCAL; 2812 flags |= RTCF_LOCAL; 2813 goto make_route; 2814 } 2815 2816 err = fib_lookup(net, fl4, res, 0); 2817 if (err) { 2818 res->fi = NULL; 2819 res->table = NULL; 2820 if (fl4->flowi4_oif && 2821 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2822 /* Apparently, routing tables are wrong. Assume, 2823 * that the destination is on link. 2824 * 2825 * WHY? DW. 2826 * Because we are allowed to send to iface 2827 * even if it has NO routes and NO assigned 2828 * addresses. When oif is specified, routing 2829 * tables are looked up with only one purpose: 2830 * to catch if destination is gatewayed, rather than 2831 * direct. Moreover, if MSG_DONTROUTE is set, 2832 * we send packet, ignoring both routing tables 2833 * and ifaddr state. --ANK 2834 * 2835 * 2836 * We could make it even if oif is unknown, 2837 * likely IPv6, but we do not. 2838 */ 2839 2840 if (fl4->saddr == 0) 2841 fl4->saddr = inet_select_addr(dev_out, 0, 2842 RT_SCOPE_LINK); 2843 res->type = RTN_UNICAST; 2844 goto make_route; 2845 } 2846 rth = ERR_PTR(err); 2847 goto out; 2848 } 2849 2850 if (res->type == RTN_LOCAL) { 2851 if (!fl4->saddr) { 2852 if (res->fi->fib_prefsrc) 2853 fl4->saddr = res->fi->fib_prefsrc; 2854 else 2855 fl4->saddr = fl4->daddr; 2856 } 2857 2858 /* L3 master device is the loopback for that domain */ 2859 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2860 net->loopback_dev; 2861 2862 /* make sure orig_oif points to fib result device even 2863 * though packet rx/tx happens over loopback or l3mdev 2864 */ 2865 orig_oif = FIB_RES_OIF(*res); 2866 2867 fl4->flowi4_oif = dev_out->ifindex; 2868 flags |= RTCF_LOCAL; 2869 goto make_route; 2870 } 2871 2872 fib_select_path(net, res, fl4, skb); 2873 2874 dev_out = FIB_RES_DEV(*res); 2875 2876 make_route: 2877 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2878 2879 out: 2880 return rth; 2881 } 2882 2883 static struct dst_ops ipv4_dst_blackhole_ops = { 2884 .family = AF_INET, 2885 .default_advmss = ipv4_default_advmss, 2886 .neigh_lookup = ipv4_neigh_lookup, 2887 .check = dst_blackhole_check, 2888 .cow_metrics = dst_blackhole_cow_metrics, 2889 .update_pmtu = dst_blackhole_update_pmtu, 2890 .redirect = dst_blackhole_redirect, 2891 .mtu = dst_blackhole_mtu, 2892 }; 2893 2894 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2895 { 2896 struct rtable *ort = dst_rtable(dst_orig); 2897 struct rtable *rt; 2898 2899 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2900 if (rt) { 2901 struct dst_entry *new = &rt->dst; 2902 2903 new->__use = 1; 2904 new->input = dst_discard; 2905 new->output = dst_discard_out; 2906 2907 new->dev = net->loopback_dev; 2908 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2909 2910 rt->rt_is_input = ort->rt_is_input; 2911 rt->rt_iif = ort->rt_iif; 2912 rt->rt_pmtu = ort->rt_pmtu; 2913 rt->rt_mtu_locked = ort->rt_mtu_locked; 2914 2915 rt->rt_genid = rt_genid_ipv4(net); 2916 rt->rt_flags = ort->rt_flags; 2917 rt->rt_type = ort->rt_type; 2918 rt->rt_uses_gateway = ort->rt_uses_gateway; 2919 rt->rt_gw_family = ort->rt_gw_family; 2920 if (rt->rt_gw_family == AF_INET) 2921 rt->rt_gw4 = ort->rt_gw4; 2922 else if (rt->rt_gw_family == AF_INET6) 2923 rt->rt_gw6 = ort->rt_gw6; 2924 } 2925 2926 dst_release(dst_orig); 2927 2928 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2929 } 2930 2931 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2932 const struct sock *sk) 2933 { 2934 struct rtable *rt = __ip_route_output_key(net, flp4); 2935 2936 if (IS_ERR(rt)) 2937 return rt; 2938 2939 if (flp4->flowi4_proto) { 2940 flp4->flowi4_oif = rt->dst.dev->ifindex; 2941 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2942 flowi4_to_flowi(flp4), 2943 sk, 0)); 2944 } 2945 2946 return rt; 2947 } 2948 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2949 2950 /* called with rcu_read_lock held */ 2951 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2952 struct rtable *rt, u32 table_id, dscp_t dscp, 2953 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2954 u32 seq, unsigned int flags) 2955 { 2956 struct rtmsg *r; 2957 struct nlmsghdr *nlh; 2958 unsigned long expires = 0; 2959 u32 error; 2960 u32 metrics[RTAX_MAX]; 2961 2962 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2963 if (!nlh) 2964 return -EMSGSIZE; 2965 2966 r = nlmsg_data(nlh); 2967 r->rtm_family = AF_INET; 2968 r->rtm_dst_len = 32; 2969 r->rtm_src_len = 0; 2970 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2971 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2972 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2973 goto nla_put_failure; 2974 r->rtm_type = rt->rt_type; 2975 r->rtm_scope = RT_SCOPE_UNIVERSE; 2976 r->rtm_protocol = RTPROT_UNSPEC; 2977 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2978 if (rt->rt_flags & RTCF_NOTIFY) 2979 r->rtm_flags |= RTM_F_NOTIFY; 2980 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2981 r->rtm_flags |= RTCF_DOREDIRECT; 2982 2983 if (nla_put_in_addr(skb, RTA_DST, dst)) 2984 goto nla_put_failure; 2985 if (src) { 2986 r->rtm_src_len = 32; 2987 if (nla_put_in_addr(skb, RTA_SRC, src)) 2988 goto nla_put_failure; 2989 } 2990 if (rt->dst.dev && 2991 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2992 goto nla_put_failure; 2993 if (lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2994 goto nla_put_failure; 2995 #ifdef CONFIG_IP_ROUTE_CLASSID 2996 if (rt->dst.tclassid && 2997 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2998 goto nla_put_failure; 2999 #endif 3000 if (fl4 && !rt_is_input_route(rt) && 3001 fl4->saddr != src) { 3002 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 3003 goto nla_put_failure; 3004 } 3005 if (rt->rt_uses_gateway) { 3006 if (rt->rt_gw_family == AF_INET && 3007 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3008 goto nla_put_failure; 3009 } else if (rt->rt_gw_family == AF_INET6) { 3010 int alen = sizeof(struct in6_addr); 3011 struct nlattr *nla; 3012 struct rtvia *via; 3013 3014 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3015 if (!nla) 3016 goto nla_put_failure; 3017 3018 via = nla_data(nla); 3019 via->rtvia_family = AF_INET6; 3020 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3021 } 3022 } 3023 3024 expires = READ_ONCE(rt->dst.expires); 3025 if (expires) { 3026 unsigned long now = jiffies; 3027 3028 if (time_before(now, expires)) 3029 expires -= now; 3030 else 3031 expires = 0; 3032 } 3033 3034 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3035 if (rt->rt_pmtu && expires) 3036 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3037 if (rt->rt_mtu_locked && expires) 3038 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3039 if (rtnetlink_put_metrics(skb, metrics) < 0) 3040 goto nla_put_failure; 3041 3042 if (fl4) { 3043 if (fl4->flowi4_mark && 3044 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3045 goto nla_put_failure; 3046 3047 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3048 nla_put_u32(skb, RTA_UID, 3049 from_kuid_munged(current_user_ns(), 3050 fl4->flowi4_uid))) 3051 goto nla_put_failure; 3052 3053 if (rt_is_input_route(rt)) { 3054 #ifdef CONFIG_IP_MROUTE 3055 if (ipv4_is_multicast(dst) && 3056 !ipv4_is_local_multicast(dst) && 3057 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3058 int err = ipmr_get_route(net, skb, 3059 fl4->saddr, fl4->daddr, 3060 r, portid); 3061 3062 if (err <= 0) { 3063 if (err == 0) 3064 return 0; 3065 goto nla_put_failure; 3066 } 3067 } else 3068 #endif 3069 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3070 goto nla_put_failure; 3071 } 3072 } 3073 3074 error = rt->dst.error; 3075 3076 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3077 goto nla_put_failure; 3078 3079 nlmsg_end(skb, nlh); 3080 return 0; 3081 3082 nla_put_failure: 3083 nlmsg_cancel(skb, nlh); 3084 return -EMSGSIZE; 3085 } 3086 3087 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3088 struct netlink_callback *cb, u32 table_id, 3089 struct fnhe_hash_bucket *bucket, int genid, 3090 int *fa_index, int fa_start, unsigned int flags) 3091 { 3092 int i; 3093 3094 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3095 struct fib_nh_exception *fnhe; 3096 3097 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3098 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3099 struct rtable *rt; 3100 int err; 3101 3102 if (*fa_index < fa_start) 3103 goto next; 3104 3105 if (fnhe->fnhe_genid != genid) 3106 goto next; 3107 3108 if (fnhe->fnhe_expires && 3109 time_after(jiffies, fnhe->fnhe_expires)) 3110 goto next; 3111 3112 rt = rcu_dereference(fnhe->fnhe_rth_input); 3113 if (!rt) 3114 rt = rcu_dereference(fnhe->fnhe_rth_output); 3115 if (!rt) 3116 goto next; 3117 3118 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3119 table_id, 0, NULL, skb, 3120 NETLINK_CB(cb->skb).portid, 3121 cb->nlh->nlmsg_seq, flags); 3122 if (err) 3123 return err; 3124 next: 3125 (*fa_index)++; 3126 } 3127 } 3128 3129 return 0; 3130 } 3131 3132 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3133 u32 table_id, struct fib_info *fi, 3134 int *fa_index, int fa_start, unsigned int flags) 3135 { 3136 struct net *net = sock_net(cb->skb->sk); 3137 int nhsel, genid = fnhe_genid(net); 3138 3139 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3140 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3141 struct fnhe_hash_bucket *bucket; 3142 int err; 3143 3144 if (nhc->nhc_flags & RTNH_F_DEAD) 3145 continue; 3146 3147 rcu_read_lock(); 3148 bucket = rcu_dereference(nhc->nhc_exceptions); 3149 err = 0; 3150 if (bucket) 3151 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3152 genid, fa_index, fa_start, 3153 flags); 3154 rcu_read_unlock(); 3155 if (err) 3156 return err; 3157 } 3158 3159 return 0; 3160 } 3161 3162 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3163 u8 ip_proto, __be16 sport, 3164 __be16 dport) 3165 { 3166 struct sk_buff *skb; 3167 struct iphdr *iph; 3168 3169 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3170 if (!skb) 3171 return NULL; 3172 3173 /* Reserve room for dummy headers, this skb can pass 3174 * through good chunk of routing engine. 3175 */ 3176 skb_reset_mac_header(skb); 3177 skb_reset_network_header(skb); 3178 skb->protocol = htons(ETH_P_IP); 3179 iph = skb_put(skb, sizeof(struct iphdr)); 3180 iph->protocol = ip_proto; 3181 iph->saddr = src; 3182 iph->daddr = dst; 3183 iph->version = 0x4; 3184 iph->frag_off = 0; 3185 iph->ihl = 0x5; 3186 skb_set_transport_header(skb, skb->len); 3187 3188 switch (iph->protocol) { 3189 case IPPROTO_UDP: { 3190 struct udphdr *udph; 3191 3192 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3193 udph->source = sport; 3194 udph->dest = dport; 3195 udp_set_len_short(udph, sizeof(struct udphdr)); 3196 udph->check = 0; 3197 break; 3198 } 3199 case IPPROTO_TCP: { 3200 struct tcphdr *tcph; 3201 3202 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3203 tcph->source = sport; 3204 tcph->dest = dport; 3205 tcph->doff = sizeof(struct tcphdr) / 4; 3206 tcph->rst = 1; 3207 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3208 src, dst, 0); 3209 break; 3210 } 3211 case IPPROTO_ICMP: { 3212 struct icmphdr *icmph; 3213 3214 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3215 icmph->type = ICMP_ECHO; 3216 icmph->code = 0; 3217 } 3218 } 3219 3220 return skb; 3221 } 3222 3223 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3224 const struct nlmsghdr *nlh, 3225 struct nlattr **tb, 3226 struct netlink_ext_ack *extack) 3227 { 3228 struct rtmsg *rtm; 3229 int i, err; 3230 3231 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3232 if (!rtm) { 3233 NL_SET_ERR_MSG(extack, 3234 "ipv4: Invalid header for route get request"); 3235 return -EINVAL; 3236 } 3237 3238 if (!netlink_strict_get_check(skb)) 3239 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3240 rtm_ipv4_policy, extack); 3241 3242 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3243 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3244 rtm->rtm_table || rtm->rtm_protocol || 3245 rtm->rtm_scope || rtm->rtm_type) { 3246 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3247 return -EINVAL; 3248 } 3249 3250 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3251 RTM_F_LOOKUP_TABLE | 3252 RTM_F_FIB_MATCH)) { 3253 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3254 return -EINVAL; 3255 } 3256 3257 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3258 rtm_ipv4_policy, extack); 3259 if (err) 3260 return err; 3261 3262 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3263 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3264 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3265 return -EINVAL; 3266 } 3267 3268 for (i = 0; i <= RTA_MAX; i++) { 3269 if (!tb[i]) 3270 continue; 3271 3272 switch (i) { 3273 case RTA_IIF: 3274 case RTA_OIF: 3275 case RTA_SRC: 3276 case RTA_DST: 3277 case RTA_IP_PROTO: 3278 case RTA_SPORT: 3279 case RTA_DPORT: 3280 case RTA_MARK: 3281 case RTA_UID: 3282 break; 3283 default: 3284 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3285 return -EINVAL; 3286 } 3287 } 3288 3289 return 0; 3290 } 3291 3292 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3293 struct netlink_ext_ack *extack) 3294 { 3295 struct net *net = sock_net(in_skb->sk); 3296 struct nlattr *tb[RTA_MAX+1]; 3297 u32 table_id = RT_TABLE_MAIN; 3298 __be16 sport = 0, dport = 0; 3299 struct fib_result res = {}; 3300 u8 ip_proto = IPPROTO_UDP; 3301 struct rtable *rt = NULL; 3302 struct sk_buff *skb; 3303 struct rtmsg *rtm; 3304 struct flowi4 fl4 = {}; 3305 __be32 dst = 0; 3306 __be32 src = 0; 3307 dscp_t dscp; 3308 kuid_t uid; 3309 u32 iif; 3310 int err; 3311 int mark; 3312 3313 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3314 if (err < 0) 3315 return err; 3316 3317 rtm = nlmsg_data(nlh); 3318 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3319 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3320 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3321 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3322 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3323 if (tb[RTA_UID]) 3324 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3325 else 3326 uid = (iif ? INVALID_UID : current_uid()); 3327 3328 if (tb[RTA_IP_PROTO]) { 3329 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3330 &ip_proto, AF_INET, extack); 3331 if (err) 3332 return err; 3333 } 3334 3335 if (tb[RTA_SPORT]) 3336 sport = nla_get_be16(tb[RTA_SPORT]); 3337 3338 if (tb[RTA_DPORT]) 3339 dport = nla_get_be16(tb[RTA_DPORT]); 3340 3341 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3342 if (!skb) 3343 return -ENOBUFS; 3344 3345 fl4.daddr = dst; 3346 fl4.saddr = src; 3347 fl4.flowi4_dscp = dscp; 3348 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3349 fl4.flowi4_mark = mark; 3350 fl4.flowi4_uid = uid; 3351 if (sport) 3352 fl4.fl4_sport = sport; 3353 if (dport) 3354 fl4.fl4_dport = dport; 3355 fl4.flowi4_proto = ip_proto; 3356 3357 rcu_read_lock(); 3358 3359 if (iif) { 3360 struct net_device *dev; 3361 3362 dev = dev_get_by_index_rcu(net, iif); 3363 if (!dev) { 3364 err = -ENODEV; 3365 goto errout_rcu; 3366 } 3367 3368 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3369 skb->dev = dev; 3370 skb->mark = mark; 3371 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3372 &res) ? -EINVAL : 0; 3373 3374 rt = skb_rtable(skb); 3375 if (err == 0 && rt->dst.error) 3376 err = -rt->dst.error; 3377 } else { 3378 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3379 skb->dev = net->loopback_dev; 3380 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3381 err = 0; 3382 if (IS_ERR(rt)) 3383 err = PTR_ERR(rt); 3384 else 3385 skb_dst_set(skb, &rt->dst); 3386 } 3387 3388 if (err) 3389 goto errout_rcu; 3390 3391 if (rtm->rtm_flags & RTM_F_NOTIFY) 3392 rt->rt_flags |= RTCF_NOTIFY; 3393 3394 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3395 table_id = res.table ? res.table->tb_id : 0; 3396 3397 /* reset skb for netlink reply msg */ 3398 skb_trim(skb, 0); 3399 skb_reset_network_header(skb); 3400 skb_reset_transport_header(skb); 3401 skb_reset_mac_header(skb); 3402 3403 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3404 struct fib_rt_info fri; 3405 3406 if (!res.fi) { 3407 err = fib_props[res.type].error; 3408 if (!err) 3409 err = -EHOSTUNREACH; 3410 goto errout_rcu; 3411 } 3412 fri.fi = res.fi; 3413 fri.tb_id = table_id; 3414 fri.dst = res.prefix; 3415 fri.dst_len = res.prefixlen; 3416 fri.dscp = res.dscp; 3417 fri.type = rt->rt_type; 3418 fri.offload = 0; 3419 fri.trap = 0; 3420 fri.offload_failed = 0; 3421 if (res.fa_head) { 3422 struct fib_alias *fa; 3423 3424 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3425 u8 slen = 32 - fri.dst_len; 3426 3427 if (fa->fa_slen == slen && 3428 fa->tb_id == fri.tb_id && 3429 fa->fa_dscp == fri.dscp && 3430 fa->fa_info == res.fi && 3431 fa->fa_type == fri.type) { 3432 fri.offload = READ_ONCE(fa->offload); 3433 fri.trap = READ_ONCE(fa->trap); 3434 fri.offload_failed = 3435 READ_ONCE(fa->offload_failed); 3436 break; 3437 } 3438 } 3439 } 3440 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3441 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3442 } else { 3443 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3444 skb, NETLINK_CB(in_skb).portid, 3445 nlh->nlmsg_seq, 0); 3446 } 3447 if (err < 0) 3448 goto errout_rcu; 3449 3450 rcu_read_unlock(); 3451 3452 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3453 3454 errout_free: 3455 return err; 3456 errout_rcu: 3457 rcu_read_unlock(); 3458 kfree_skb(skb); 3459 goto errout_free; 3460 } 3461 3462 void ip_rt_multicast_event(struct in_device *in_dev) 3463 { 3464 rt_cache_flush(dev_net(in_dev->dev)); 3465 } 3466 3467 #ifdef CONFIG_SYSCTL 3468 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3469 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3470 static int ip_rt_gc_elasticity __read_mostly = 8; 3471 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3472 3473 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3474 void *buffer, size_t *lenp, loff_t *ppos) 3475 { 3476 struct net *net = (struct net *)__ctl->extra1; 3477 3478 if (write) { 3479 rt_cache_flush(net); 3480 fnhe_genid_bump(net); 3481 return 0; 3482 } 3483 3484 return -EINVAL; 3485 } 3486 3487 static struct ctl_table ipv4_route_table[] = { 3488 { 3489 .procname = "gc_thresh", 3490 .data = &ipv4_dst_ops.gc_thresh, 3491 .maxlen = sizeof(int), 3492 .mode = 0644, 3493 .proc_handler = proc_dointvec, 3494 }, 3495 { 3496 .procname = "max_size", 3497 .data = &ip_rt_max_size, 3498 .maxlen = sizeof(int), 3499 .mode = 0644, 3500 .proc_handler = proc_dointvec, 3501 }, 3502 { 3503 /* Deprecated. Use gc_min_interval_ms */ 3504 3505 .procname = "gc_min_interval", 3506 .data = &ip_rt_gc_min_interval, 3507 .maxlen = sizeof(int), 3508 .mode = 0644, 3509 .proc_handler = proc_dointvec_jiffies, 3510 }, 3511 { 3512 .procname = "gc_min_interval_ms", 3513 .data = &ip_rt_gc_min_interval, 3514 .maxlen = sizeof(int), 3515 .mode = 0644, 3516 .proc_handler = proc_dointvec_ms_jiffies, 3517 }, 3518 { 3519 .procname = "gc_timeout", 3520 .data = &ip_rt_gc_timeout, 3521 .maxlen = sizeof(int), 3522 .mode = 0644, 3523 .proc_handler = proc_dointvec_jiffies, 3524 }, 3525 { 3526 .procname = "gc_interval", 3527 .data = &ip_rt_gc_interval, 3528 .maxlen = sizeof(int), 3529 .mode = 0644, 3530 .proc_handler = proc_dointvec_jiffies, 3531 }, 3532 { 3533 .procname = "redirect_load", 3534 .data = &ip_rt_redirect_load, 3535 .maxlen = sizeof(int), 3536 .mode = 0644, 3537 .proc_handler = proc_dointvec, 3538 }, 3539 { 3540 .procname = "redirect_number", 3541 .data = &ip_rt_redirect_number, 3542 .maxlen = sizeof(int), 3543 .mode = 0644, 3544 .proc_handler = proc_dointvec, 3545 }, 3546 { 3547 .procname = "redirect_silence", 3548 .data = &ip_rt_redirect_silence, 3549 .maxlen = sizeof(int), 3550 .mode = 0644, 3551 .proc_handler = proc_dointvec, 3552 }, 3553 { 3554 .procname = "error_cost", 3555 .data = &ip_rt_error_cost, 3556 .maxlen = sizeof(int), 3557 .mode = 0644, 3558 .proc_handler = proc_dointvec, 3559 }, 3560 { 3561 .procname = "error_burst", 3562 .data = &ip_rt_error_burst, 3563 .maxlen = sizeof(int), 3564 .mode = 0644, 3565 .proc_handler = proc_dointvec, 3566 }, 3567 { 3568 .procname = "gc_elasticity", 3569 .data = &ip_rt_gc_elasticity, 3570 .maxlen = sizeof(int), 3571 .mode = 0644, 3572 .proc_handler = proc_dointvec, 3573 }, 3574 }; 3575 3576 static const char ipv4_route_flush_procname[] = "flush"; 3577 3578 static struct ctl_table ipv4_route_netns_table[] = { 3579 { 3580 .procname = ipv4_route_flush_procname, 3581 .maxlen = sizeof(int), 3582 .mode = 0200, 3583 .proc_handler = ipv4_sysctl_rtcache_flush, 3584 }, 3585 { 3586 .procname = "min_pmtu", 3587 .data = &init_net.ipv4.ip_rt_min_pmtu, 3588 .maxlen = sizeof(int), 3589 .mode = 0644, 3590 .proc_handler = proc_dointvec_minmax, 3591 .extra1 = &ip_min_valid_pmtu, 3592 }, 3593 { 3594 .procname = "mtu_expires", 3595 .data = &init_net.ipv4.ip_rt_mtu_expires, 3596 .maxlen = sizeof(int), 3597 .mode = 0644, 3598 .proc_handler = proc_dointvec_jiffies, 3599 }, 3600 { 3601 .procname = "min_adv_mss", 3602 .data = &init_net.ipv4.ip_rt_min_advmss, 3603 .maxlen = sizeof(int), 3604 .mode = 0644, 3605 .proc_handler = proc_dointvec, 3606 }, 3607 }; 3608 3609 static __net_init int sysctl_route_net_init(struct net *net) 3610 { 3611 struct ctl_table *tbl; 3612 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3613 3614 tbl = ipv4_route_netns_table; 3615 if (!net_eq(net, &init_net)) { 3616 int i; 3617 3618 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3619 if (!tbl) 3620 goto err_dup; 3621 3622 /* Don't export non-whitelisted sysctls to unprivileged users */ 3623 if (net->user_ns != &init_user_ns) { 3624 if (tbl[0].procname != ipv4_route_flush_procname) 3625 table_size = 0; 3626 } 3627 3628 /* Update the variables to point into the current struct net 3629 * except for the first element flush 3630 */ 3631 for (i = 1; i < table_size; i++) 3632 tbl[i].data += (void *)net - (void *)&init_net; 3633 } 3634 tbl[0].extra1 = net; 3635 3636 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3637 tbl, table_size); 3638 if (!net->ipv4.route_hdr) 3639 goto err_reg; 3640 return 0; 3641 3642 err_reg: 3643 if (tbl != ipv4_route_netns_table) 3644 kfree(tbl); 3645 err_dup: 3646 return -ENOMEM; 3647 } 3648 3649 static __net_exit void sysctl_route_net_exit(struct net *net) 3650 { 3651 const struct ctl_table *tbl; 3652 3653 tbl = net->ipv4.route_hdr->ctl_table_arg; 3654 unregister_net_sysctl_table(net->ipv4.route_hdr); 3655 BUG_ON(tbl == ipv4_route_netns_table); 3656 kfree(tbl); 3657 } 3658 3659 static __net_initdata struct pernet_operations sysctl_route_ops = { 3660 .init = sysctl_route_net_init, 3661 .exit = sysctl_route_net_exit, 3662 }; 3663 #endif 3664 3665 static __net_init int netns_ip_rt_init(struct net *net) 3666 { 3667 /* Set default value for namespaceified sysctls */ 3668 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3669 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3670 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3671 return 0; 3672 } 3673 3674 static struct pernet_operations __net_initdata ip_rt_ops = { 3675 .init = netns_ip_rt_init, 3676 }; 3677 3678 static __net_init int rt_genid_init(struct net *net) 3679 { 3680 atomic_set(&net->ipv4.rt_genid, 0); 3681 atomic_set(&net->fnhe_genid, 0); 3682 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3683 return 0; 3684 } 3685 3686 static __net_initdata struct pernet_operations rt_genid_ops = { 3687 .init = rt_genid_init, 3688 }; 3689 3690 static int __net_init ipv4_inetpeer_init(struct net *net) 3691 { 3692 struct inet_peer_base *bp = kmalloc_obj(*bp); 3693 3694 if (!bp) 3695 return -ENOMEM; 3696 inet_peer_base_init(bp); 3697 net->ipv4.peers = bp; 3698 return 0; 3699 } 3700 3701 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3702 { 3703 struct inet_peer_base *bp = net->ipv4.peers; 3704 3705 net->ipv4.peers = NULL; 3706 inetpeer_invalidate_tree(bp); 3707 kfree(bp); 3708 } 3709 3710 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3711 .init = ipv4_inetpeer_init, 3712 .exit = ipv4_inetpeer_exit, 3713 }; 3714 3715 #ifdef CONFIG_IP_ROUTE_CLASSID 3716 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3717 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3718 3719 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3720 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3721 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3722 }; 3723 3724 int __init ip_rt_init(void) 3725 { 3726 void *idents_hash; 3727 int cpu; 3728 3729 /* For modern hosts, this will use 2 MB of memory */ 3730 idents_hash = alloc_large_system_hash("IP idents", 3731 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3732 0, 3733 16, /* one bucket per 64 KB */ 3734 HASH_ZERO, 3735 NULL, 3736 &ip_idents_mask, 3737 2048, 3738 256*1024); 3739 3740 ip_idents = idents_hash; 3741 3742 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3743 3744 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3745 3746 for_each_possible_cpu(cpu) { 3747 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3748 3749 INIT_LIST_HEAD(&ul->head); 3750 spin_lock_init(&ul->lock); 3751 } 3752 #ifdef CONFIG_IP_ROUTE_CLASSID 3753 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3754 if (!ip_rt_acct) 3755 panic("IP: failed to allocate ip_rt_acct\n"); 3756 #endif 3757 3758 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3759 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3760 3761 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3762 3763 if (dst_entries_init(&ipv4_dst_ops) < 0) 3764 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3765 3766 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3767 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3768 3769 ipv4_dst_ops.gc_thresh = ~0; 3770 ip_rt_max_size = INT_MAX; 3771 3772 devinet_init(); 3773 ip_fib_init(); 3774 3775 if (ip_rt_proc_init()) 3776 pr_err("Unable to create route proc files\n"); 3777 #ifdef CONFIG_XFRM 3778 xfrm_init(); 3779 xfrm4_init(); 3780 #endif 3781 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3782 3783 #ifdef CONFIG_SYSCTL 3784 register_pernet_subsys(&sysctl_route_ops); 3785 #endif 3786 register_pernet_subsys(&ip_rt_ops); 3787 register_pernet_subsys(&rt_genid_ops); 3788 register_pernet_subsys(&ipv4_inetpeer_ops); 3789 return 0; 3790 } 3791 3792 #ifdef CONFIG_SYSCTL 3793 /* 3794 * We really need to sanitize the damn ipv4 init order, then all 3795 * this nonsense will go away. 3796 */ 3797 void __init ip_static_sysctl_init(void) 3798 { 3799 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3800 } 3801 #endif 3802