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 /* Update the PMTU of an exception when: 745 * - the new MTU of the first hop becomes smaller than the PMTU 746 * - the old MTU was the same as the PMTU, and it limited discovery of 747 * larger MTUs on the path. With that limit raised, we can now 748 * discover larger MTUs 749 * A special case is locked exceptions, for which the PMTU is smaller 750 * than the minimal accepted PMTU: 751 * - if the new MTU is greater than the PMTU, don't make any change 752 * - otherwise, unlock and set PMTU 753 * 754 * fnhe_lock keeps fnhe_pmtu and fnhe_mtu_locked consistent against 755 * update_or_create_fnhe(), which sets both under the same lock. 756 */ 757 void fnhe_update_pmtu(struct fib_nh_exception *fnhe, u32 new, u32 orig) 758 { 759 spin_lock_bh(&fnhe_lock); 760 761 if (fnhe->fnhe_mtu_locked) { 762 if (new <= fnhe->fnhe_pmtu) { 763 fnhe->fnhe_pmtu = new; 764 fnhe->fnhe_mtu_locked = false; 765 } 766 } else if (new < fnhe->fnhe_pmtu || orig == fnhe->fnhe_pmtu) { 767 fnhe->fnhe_pmtu = new; 768 } 769 770 spin_unlock_bh(&fnhe_lock); 771 } 772 773 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 774 bool kill_route) 775 { 776 __be32 new_gw = icmp_hdr(skb)->un.gateway; 777 __be32 old_gw = ip_hdr(skb)->saddr; 778 struct net_device *dev = skb->dev; 779 struct in_device *in_dev; 780 struct fib_result res; 781 struct neighbour *n; 782 struct net *net; 783 784 switch (icmp_hdr(skb)->code & 7) { 785 case ICMP_REDIR_NET: 786 case ICMP_REDIR_NETTOS: 787 case ICMP_REDIR_HOST: 788 case ICMP_REDIR_HOSTTOS: 789 break; 790 791 default: 792 return; 793 } 794 795 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 796 return; 797 798 in_dev = __in_dev_get_rcu(dev); 799 if (!in_dev) 800 return; 801 802 net = dev_net(dev); 803 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 804 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 805 ipv4_is_zeronet(new_gw)) 806 goto reject_redirect; 807 808 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 809 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 810 goto reject_redirect; 811 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 812 goto reject_redirect; 813 } else { 814 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 815 goto reject_redirect; 816 } 817 818 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 819 if (!n) 820 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 821 if (!IS_ERR(n)) { 822 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 823 neigh_event_send(n, NULL); 824 } else { 825 if (fib_lookup(net, fl4, &res, 0) == 0) { 826 struct fib_nh_common *nhc; 827 828 fib_select_path(net, &res, fl4, skb); 829 nhc = FIB_RES_NHC(res); 830 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 831 0, false, 832 jiffies + ip_rt_gc_timeout); 833 } 834 if (kill_route) 835 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 836 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 837 } 838 neigh_release(n); 839 } 840 return; 841 842 reject_redirect: 843 #ifdef CONFIG_IP_ROUTE_VERBOSE 844 if (IN_DEV_LOG_MARTIANS(in_dev)) { 845 const struct iphdr *iph = (const struct iphdr *) skb->data; 846 __be32 daddr = iph->daddr; 847 __be32 saddr = iph->saddr; 848 849 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 850 " Advised path = %pI4 -> %pI4\n", 851 &old_gw, dev->name, &new_gw, 852 &saddr, &daddr); 853 } 854 #endif 855 ; 856 } 857 858 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 859 { 860 struct rtable *rt; 861 struct flowi4 fl4; 862 const struct iphdr *iph = (const struct iphdr *) skb->data; 863 struct net *net = dev_net(skb->dev); 864 int oif = skb->dev->ifindex; 865 u8 prot = iph->protocol; 866 u32 mark = skb->mark; 867 __u8 tos = iph->tos; 868 869 rt = dst_rtable(dst); 870 871 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 872 __ip_do_redirect(rt, skb, &fl4, true); 873 } 874 875 static void ipv4_negative_advice(struct sock *sk, 876 struct dst_entry *dst) 877 { 878 struct rtable *rt = dst_rtable(dst); 879 880 if ((READ_ONCE(dst->obsolete) > 0) || 881 (rt->rt_flags & RTCF_REDIRECTED) || 882 READ_ONCE(rt->dst.expires)) 883 sk_dst_reset(sk); 884 } 885 886 /* 887 * Algorithm: 888 * 1. The first ip_rt_redirect_number redirects are sent 889 * with exponential backoff, then we stop sending them at all, 890 * assuming that the host ignores our redirects. 891 * 2. If we did not see packets requiring redirects 892 * during ip_rt_redirect_silence, we assume that the host 893 * forgot redirected route and start to send redirects again. 894 * 895 * This algorithm is much cheaper and more intelligent than dumb load limiting 896 * in icmp.c. 897 * 898 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 899 * and "frag. need" (breaks PMTU discovery) in icmp.c. 900 */ 901 902 void ip_rt_send_redirect(struct sk_buff *skb) 903 { 904 struct rtable *rt = skb_rtable(skb); 905 struct in_device *in_dev; 906 struct net_device *dev; 907 struct inet_peer *peer; 908 int log_martians; 909 struct net *net; 910 int vif; 911 912 rcu_read_lock(); 913 dev = dst_dev_rcu(&rt->dst); 914 in_dev = __in_dev_get_rcu(dev); 915 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 916 rcu_read_unlock(); 917 return; 918 } 919 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 920 vif = l3mdev_master_ifindex_rcu(dev); 921 922 net = dev_net_rcu(dev); 923 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 924 if (!peer) { 925 rcu_read_unlock(); 926 return; 927 } 928 929 /* No redirected packets during ip_rt_redirect_silence; 930 * reset the algorithm. 931 */ 932 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 933 peer->rate_tokens = 0; 934 peer->n_redirects = 0; 935 } 936 937 /* Too many ignored redirects; do not send anything 938 * set dst.rate_last to the last seen redirected packet. 939 */ 940 if (peer->n_redirects >= ip_rt_redirect_number) { 941 peer->rate_last = jiffies; 942 goto out_unlock; 943 } 944 945 /* Check for load limit; set rate_last to the latest sent 946 * redirect. 947 */ 948 if (peer->n_redirects == 0 || 949 time_after(jiffies, 950 (peer->rate_last + 951 (ip_rt_redirect_load << peer->n_redirects)))) { 952 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 953 954 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 955 peer->rate_last = jiffies; 956 ++peer->n_redirects; 957 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 958 peer->n_redirects == ip_rt_redirect_number) 959 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 960 &ip_hdr(skb)->saddr, inet_iif(skb), 961 &ip_hdr(skb)->daddr, &gw); 962 } 963 out_unlock: 964 rcu_read_unlock(); 965 } 966 967 static int ip_error(struct sk_buff *skb) 968 { 969 struct rtable *rt = skb_rtable(skb); 970 struct net_device *dev = skb->dev; 971 struct in_device *in_dev; 972 struct inet_peer *peer; 973 unsigned long now; 974 struct net *net; 975 SKB_DR(reason); 976 bool send; 977 int code; 978 979 if (netif_is_l3_master(skb->dev)) { 980 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 981 if (!dev) 982 goto out; 983 } 984 985 in_dev = __in_dev_get_rcu(dev); 986 987 /* IP on this device is disabled. */ 988 if (!in_dev) 989 goto out; 990 991 net = dev_net(rt->dst.dev); 992 if (!IN_DEV_FORWARD(in_dev)) { 993 switch (rt->dst.error) { 994 case EHOSTUNREACH: 995 SKB_DR_SET(reason, IP_INADDRERRORS); 996 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 997 break; 998 999 case ENETUNREACH: 1000 SKB_DR_SET(reason, IP_INNOROUTES); 1001 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 1002 break; 1003 } 1004 goto out; 1005 } 1006 1007 switch (rt->dst.error) { 1008 case EINVAL: 1009 default: 1010 goto out; 1011 case EHOSTUNREACH: 1012 code = ICMP_HOST_UNREACH; 1013 break; 1014 case ENETUNREACH: 1015 code = ICMP_NET_UNREACH; 1016 SKB_DR_SET(reason, IP_INNOROUTES); 1017 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 1018 break; 1019 case EACCES: 1020 code = ICMP_PKT_FILTERED; 1021 break; 1022 } 1023 1024 rcu_read_lock(); 1025 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1026 l3mdev_master_ifindex_rcu(skb->dev)); 1027 send = true; 1028 if (peer) { 1029 now = jiffies; 1030 peer->rate_tokens += now - peer->rate_last; 1031 if (peer->rate_tokens > ip_rt_error_burst) 1032 peer->rate_tokens = ip_rt_error_burst; 1033 peer->rate_last = now; 1034 if (peer->rate_tokens >= ip_rt_error_cost) 1035 peer->rate_tokens -= ip_rt_error_cost; 1036 else 1037 send = false; 1038 } 1039 rcu_read_unlock(); 1040 1041 if (send) 1042 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1043 1044 out: kfree_skb_reason(skb, reason); 1045 return 0; 1046 } 1047 1048 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1049 { 1050 struct dst_entry *dst = &rt->dst; 1051 struct fib_result res; 1052 bool lock = false; 1053 struct net *net; 1054 u32 old_mtu; 1055 1056 if (ip_mtu_locked(dst)) 1057 return; 1058 1059 old_mtu = ipv4_mtu(dst); 1060 if (old_mtu < mtu) 1061 return; 1062 1063 rcu_read_lock(); 1064 net = dst_dev_net_rcu(dst); 1065 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1066 lock = true; 1067 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1068 } 1069 1070 if (rt->rt_pmtu == mtu && !lock && 1071 time_before(jiffies, READ_ONCE(dst->expires) - 1072 net->ipv4.ip_rt_mtu_expires / 2)) 1073 goto out; 1074 1075 if (fib_lookup(net, fl4, &res, 0) == 0) { 1076 struct fib_nh_common *nhc; 1077 1078 fib_select_path(net, &res, fl4, NULL); 1079 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1080 if (fib_info_num_path(res.fi) > 1) { 1081 int nhsel; 1082 1083 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1084 nhc = fib_info_nhc(res.fi, nhsel); 1085 if (!nhc) 1086 break; 1087 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1088 jiffies + net->ipv4.ip_rt_mtu_expires); 1089 } 1090 goto out; 1091 } 1092 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1093 nhc = FIB_RES_NHC(res); 1094 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1095 jiffies + net->ipv4.ip_rt_mtu_expires); 1096 } 1097 out: 1098 rcu_read_unlock(); 1099 } 1100 1101 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1102 struct sk_buff *skb, u32 mtu, 1103 bool confirm_neigh) 1104 { 1105 struct rtable *rt = dst_rtable(dst); 1106 struct flowi4 fl4; 1107 1108 ip_rt_build_flow_key(&fl4, sk, skb); 1109 1110 /* Don't make lookup fail for bridged encapsulations */ 1111 if (skb && netif_is_any_bridge_port(skb->dev)) 1112 fl4.flowi4_oif = 0; 1113 1114 __ip_rt_update_pmtu(rt, &fl4, mtu); 1115 } 1116 1117 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1118 int oif, u8 protocol) 1119 { 1120 const struct iphdr *iph = (const struct iphdr *)skb->data; 1121 struct flowi4 fl4; 1122 struct rtable *rt; 1123 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1124 1125 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1126 0); 1127 rt = __ip_route_output_key(net, &fl4); 1128 if (!IS_ERR(rt)) { 1129 __ip_rt_update_pmtu(rt, &fl4, mtu); 1130 ip_rt_put(rt); 1131 } 1132 } 1133 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1134 1135 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1136 { 1137 const struct iphdr *iph = (const struct iphdr *)skb->data; 1138 struct flowi4 fl4; 1139 struct rtable *rt; 1140 1141 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1142 1143 if (!fl4.flowi4_mark) 1144 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1145 1146 rt = __ip_route_output_key(sock_net(sk), &fl4); 1147 if (!IS_ERR(rt)) { 1148 __ip_rt_update_pmtu(rt, &fl4, mtu); 1149 ip_rt_put(rt); 1150 } 1151 } 1152 1153 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1154 { 1155 const struct iphdr *iph = (const struct iphdr *)skb->data; 1156 struct flowi4 fl4; 1157 struct rtable *rt; 1158 struct dst_entry *odst = NULL; 1159 bool new = false; 1160 struct net *net = sock_net(sk); 1161 1162 bh_lock_sock(sk); 1163 1164 if (!ip_sk_accept_pmtu(sk)) 1165 goto out; 1166 1167 odst = sk_dst_get(sk); 1168 1169 if (sock_owned_by_user(sk) || !odst) { 1170 __ipv4_sk_update_pmtu(skb, sk, mtu); 1171 goto out; 1172 } 1173 1174 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1175 1176 rt = dst_rtable(odst); 1177 if (READ_ONCE(odst->obsolete) && !odst->ops->check(odst, 0)) { 1178 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1179 if (IS_ERR(rt)) 1180 goto out; 1181 1182 new = true; 1183 } 1184 1185 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1186 1187 if (!dst_check(&rt->dst, 0)) { 1188 if (new) 1189 dst_release(&rt->dst); 1190 1191 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1192 if (IS_ERR(rt)) 1193 goto out; 1194 1195 new = true; 1196 } 1197 1198 if (new) 1199 sk_dst_set(sk, &rt->dst); 1200 1201 out: 1202 bh_unlock_sock(sk); 1203 dst_release(odst); 1204 } 1205 1206 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1207 int oif, u8 protocol) 1208 { 1209 const struct iphdr *iph = (const struct iphdr *)skb->data; 1210 struct flowi4 fl4; 1211 struct rtable *rt; 1212 1213 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1214 rt = __ip_route_output_key(net, &fl4); 1215 if (!IS_ERR(rt)) { 1216 __ip_do_redirect(rt, skb, &fl4, false); 1217 ip_rt_put(rt); 1218 } 1219 } 1220 EXPORT_SYMBOL_GPL(ipv4_redirect); 1221 1222 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1223 { 1224 const struct iphdr *iph = (const struct iphdr *)skb->data; 1225 struct flowi4 fl4; 1226 struct rtable *rt; 1227 struct net *net = sock_net(sk); 1228 1229 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1230 rt = __ip_route_output_key(net, &fl4); 1231 if (!IS_ERR(rt)) { 1232 __ip_do_redirect(rt, skb, &fl4, false); 1233 ip_rt_put(rt); 1234 } 1235 } 1236 1237 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1238 u32 cookie) 1239 { 1240 struct rtable *rt = dst_rtable(dst); 1241 1242 /* All IPV4 dsts are created with ->obsolete set to the value 1243 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1244 * into this function always. 1245 * 1246 * When a PMTU/redirect information update invalidates a route, 1247 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1248 * DST_OBSOLETE_DEAD. 1249 */ 1250 if (READ_ONCE(dst->obsolete) != DST_OBSOLETE_FORCE_CHK || 1251 rt_is_expired(rt)) 1252 return NULL; 1253 return dst; 1254 } 1255 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1256 1257 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1258 { 1259 struct inet_skb_parm parm; 1260 struct net_device *dev; 1261 int res; 1262 1263 /* Recompile ip options since IPCB may not be valid anymore. 1264 * Also check we have a reasonable ipv4 header. 1265 */ 1266 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1267 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1268 return; 1269 1270 memset(&parm, 0, sizeof(parm)); 1271 if (ip_hdr(skb)->ihl > 5) { 1272 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1273 return; 1274 parm.opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1275 1276 rcu_read_lock(); 1277 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1278 res = __ip_options_compile(dev_net(dev), &parm.opt, skb, NULL); 1279 rcu_read_unlock(); 1280 1281 if (res) 1282 return; 1283 } 1284 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &parm); 1285 } 1286 1287 static void ipv4_link_failure(struct sk_buff *skb) 1288 { 1289 struct rtable *rt; 1290 1291 ipv4_send_dest_unreach(skb); 1292 1293 rt = skb_rtable(skb); 1294 if (rt) 1295 dst_set_expires(&rt->dst, 0); 1296 } 1297 1298 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1299 { 1300 pr_debug("%s: %pI4 -> %pI4, %s\n", 1301 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1302 skb->dev ? skb->dev->name : "?"); 1303 kfree_skb(skb); 1304 WARN_ON_ONCE(1); 1305 return 0; 1306 } 1307 1308 /* 1309 * We do not cache source address of outgoing interface, 1310 * because it is used only by IP RR, TS and SRR options, 1311 * so that it out of fast path. 1312 * 1313 * BTW remember: "addr" is allowed to be not aligned 1314 * in IP options! 1315 */ 1316 1317 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1318 { 1319 __be32 src; 1320 1321 rcu_read_lock(); 1322 if (rt_is_output_route(rt)) { 1323 src = ip_hdr(skb)->saddr; 1324 } else { 1325 struct net_device *dev = dst_dev_rcu(&rt->dst); 1326 struct net *net = dev_net_rcu(dev); 1327 struct iphdr *iph = ip_hdr(skb); 1328 struct fib_result res; 1329 struct flowi4 fl4 = { 1330 .daddr = iph->daddr, 1331 .saddr = iph->saddr, 1332 .flowi4_dscp = ip4h_dscp(iph), 1333 .flowi4_oif = dev->ifindex, 1334 .flowi4_iif = skb->dev->ifindex, 1335 .flowi4_mark = skb->mark, 1336 }; 1337 1338 if (fib_lookup(net, &fl4, &res, 0) == 0) 1339 src = fib_result_prefsrc(net, &res); 1340 else 1341 src = inet_select_addr(dev, 1342 rt_nexthop(rt, iph->daddr), 1343 RT_SCOPE_UNIVERSE); 1344 } 1345 rcu_read_unlock(); 1346 1347 memcpy(addr, &src, 4); 1348 } 1349 1350 #ifdef CONFIG_IP_ROUTE_CLASSID 1351 static void set_class_tag(struct rtable *rt, u32 tag) 1352 { 1353 if (!(rt->dst.tclassid & 0xFFFF)) 1354 rt->dst.tclassid |= tag & 0xFFFF; 1355 if (!(rt->dst.tclassid & 0xFFFF0000)) 1356 rt->dst.tclassid |= tag & 0xFFFF0000; 1357 } 1358 #endif 1359 1360 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1361 { 1362 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1363 unsigned int advmss; 1364 struct net *net; 1365 1366 rcu_read_lock(); 1367 net = dst_dev_net_rcu(dst); 1368 advmss = max_t(unsigned int, ip_dst_mtu_configured(dst) - header_size, 1369 net->ipv4.ip_rt_min_advmss); 1370 rcu_read_unlock(); 1371 1372 return min(advmss, IPV4_MAX_PMTU - header_size); 1373 } 1374 1375 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1376 { 1377 return ip_dst_mtu_maybe_forward(dst, false); 1378 } 1379 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1380 1381 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1382 { 1383 struct fnhe_hash_bucket *hash; 1384 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1385 u32 hval = fnhe_hashfun(daddr); 1386 1387 spin_lock_bh(&fnhe_lock); 1388 1389 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1390 lockdep_is_held(&fnhe_lock)); 1391 hash += hval; 1392 1393 fnhe_p = &hash->chain; 1394 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1395 while (fnhe) { 1396 if (fnhe->fnhe_daddr == daddr) { 1397 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1398 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1399 /* set fnhe_daddr to 0 to ensure it won't bind with 1400 * new dsts in rt_bind_exception(). 1401 */ 1402 fnhe->fnhe_daddr = 0; 1403 fnhe_flush_routes(fnhe); 1404 kfree_rcu(fnhe, rcu); 1405 break; 1406 } 1407 fnhe_p = &fnhe->fnhe_next; 1408 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1409 lockdep_is_held(&fnhe_lock)); 1410 } 1411 1412 spin_unlock_bh(&fnhe_lock); 1413 } 1414 1415 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1416 __be32 daddr) 1417 { 1418 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1419 struct fib_nh_exception *fnhe; 1420 u32 hval; 1421 1422 if (!hash) 1423 return NULL; 1424 1425 hval = fnhe_hashfun(daddr); 1426 1427 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1428 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1429 if (fnhe->fnhe_daddr == daddr) { 1430 if (fnhe->fnhe_expires && 1431 time_after(jiffies, fnhe->fnhe_expires)) { 1432 ip_del_fnhe(nhc, daddr); 1433 break; 1434 } 1435 return fnhe; 1436 } 1437 } 1438 return NULL; 1439 } 1440 1441 /* MTU selection: 1442 * 1. mtu on route is locked - use it 1443 * 2. mtu from nexthop exception 1444 * 3. mtu from egress device 1445 */ 1446 1447 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1448 { 1449 struct fib_nh_common *nhc = res->nhc; 1450 struct net_device *dev = nhc->nhc_dev; 1451 struct fib_info *fi = res->fi; 1452 u32 mtu = 0; 1453 1454 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1455 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1456 mtu = fi->fib_mtu; 1457 1458 if (likely(!mtu)) { 1459 struct fib_nh_exception *fnhe; 1460 1461 fnhe = find_exception(nhc, daddr); 1462 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1463 mtu = fnhe->fnhe_pmtu; 1464 } 1465 1466 if (likely(!mtu)) 1467 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1468 1469 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1470 } 1471 1472 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1473 __be32 daddr, const bool do_cache) 1474 { 1475 bool ret = false; 1476 1477 spin_lock_bh(&fnhe_lock); 1478 1479 if (daddr == fnhe->fnhe_daddr) { 1480 struct rtable __rcu **porig; 1481 struct rtable *orig; 1482 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1483 1484 if (rt_is_input_route(rt)) 1485 porig = &fnhe->fnhe_rth_input; 1486 else 1487 porig = &fnhe->fnhe_rth_output; 1488 orig = rcu_dereference(*porig); 1489 1490 if (fnhe->fnhe_genid != genid) { 1491 fnhe->fnhe_genid = genid; 1492 fnhe->fnhe_gw = 0; 1493 fnhe->fnhe_pmtu = 0; 1494 fnhe->fnhe_expires = 0; 1495 fnhe->fnhe_mtu_locked = false; 1496 fnhe_flush_routes(fnhe); 1497 orig = NULL; 1498 } 1499 fill_route_from_fnhe(rt, fnhe); 1500 if (!rt->rt_gw4) { 1501 rt->rt_gw4 = daddr; 1502 rt->rt_gw_family = AF_INET; 1503 } 1504 1505 if (do_cache) { 1506 dst_hold(&rt->dst); 1507 rcu_assign_pointer(*porig, rt); 1508 if (orig) { 1509 dst_dev_put(&orig->dst); 1510 dst_release(&orig->dst); 1511 } 1512 ret = true; 1513 } 1514 1515 fnhe->fnhe_stamp = jiffies; 1516 } 1517 spin_unlock_bh(&fnhe_lock); 1518 1519 return ret; 1520 } 1521 1522 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1523 { 1524 struct rtable *orig, *prev, **p; 1525 bool ret = true; 1526 1527 if (rt_is_input_route(rt)) { 1528 p = (struct rtable **)&nhc->nhc_rth_input; 1529 } else { 1530 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1531 } 1532 orig = *p; 1533 1534 /* hold dst before doing cmpxchg() to avoid race condition 1535 * on this dst 1536 */ 1537 dst_hold(&rt->dst); 1538 prev = cmpxchg(p, orig, rt); 1539 if (prev == orig) { 1540 if (orig) { 1541 rt_add_uncached_list(orig); 1542 dst_release(&orig->dst); 1543 } 1544 } else { 1545 dst_release(&rt->dst); 1546 ret = false; 1547 } 1548 1549 return ret; 1550 } 1551 1552 struct uncached_list { 1553 spinlock_t lock; 1554 struct list_head head; 1555 }; 1556 1557 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1558 1559 void rt_add_uncached_list(struct rtable *rt) 1560 { 1561 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1562 1563 rt->dst.rt_uncached_list = ul; 1564 1565 spin_lock_bh(&ul->lock); 1566 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1567 spin_unlock_bh(&ul->lock); 1568 } 1569 1570 void rt_del_uncached_list(struct rtable *rt) 1571 { 1572 struct uncached_list *ul = rt->dst.rt_uncached_list; 1573 1574 if (ul) { 1575 spin_lock_bh(&ul->lock); 1576 list_del_init(&rt->dst.rt_uncached); 1577 spin_unlock_bh(&ul->lock); 1578 } 1579 } 1580 1581 static void ipv4_dst_destroy(struct dst_entry *dst) 1582 { 1583 ip_dst_metrics_put(dst); 1584 rt_del_uncached_list(dst_rtable(dst)); 1585 } 1586 1587 void rt_flush_dev(struct net_device *dev) 1588 { 1589 struct rtable *rt, *safe; 1590 int cpu; 1591 1592 for_each_possible_cpu(cpu) { 1593 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1594 1595 if (list_empty(&ul->head)) 1596 continue; 1597 1598 spin_lock_bh(&ul->lock); 1599 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1600 if (rt->dst.dev != dev) 1601 continue; 1602 rcu_assign_pointer(rt->dst.dev_rcu, blackhole_netdev); 1603 netdev_ref_replace(dev, blackhole_netdev, 1604 &rt->dst.dev_tracker, GFP_ATOMIC); 1605 list_del_init(&rt->dst.rt_uncached); 1606 } 1607 spin_unlock_bh(&ul->lock); 1608 } 1609 } 1610 1611 static bool rt_cache_valid(const struct rtable *rt) 1612 { 1613 return rt && 1614 READ_ONCE(rt->dst.obsolete) == DST_OBSOLETE_FORCE_CHK && 1615 !rt_is_expired(rt); 1616 } 1617 1618 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1619 const struct fib_result *res, 1620 struct fib_nh_exception *fnhe, 1621 struct fib_info *fi, u16 type, u32 itag, 1622 const bool do_cache) 1623 { 1624 bool cached = false; 1625 1626 if (fi) { 1627 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1628 1629 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1630 rt->rt_uses_gateway = 1; 1631 rt->rt_gw_family = nhc->nhc_gw_family; 1632 /* only INET and INET6 are supported */ 1633 if (likely(nhc->nhc_gw_family == AF_INET)) 1634 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1635 else 1636 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1637 } 1638 1639 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1640 1641 #ifdef CONFIG_IP_ROUTE_CLASSID 1642 if (nhc->nhc_family == AF_INET) { 1643 struct fib_nh *nh; 1644 1645 nh = container_of(nhc, struct fib_nh, nh_common); 1646 rt->dst.tclassid = nh->nh_tclassid; 1647 } 1648 #endif 1649 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1650 if (unlikely(fnhe)) 1651 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1652 else if (do_cache) 1653 cached = rt_cache_route(nhc, rt); 1654 if (unlikely(!cached)) { 1655 /* Routes we intend to cache in nexthop exception or 1656 * FIB nexthop have the DST_NOCACHE bit clear. 1657 * However, if we are unsuccessful at storing this 1658 * route into the cache we really need to set it. 1659 */ 1660 if (!rt->rt_gw4) { 1661 rt->rt_gw_family = AF_INET; 1662 rt->rt_gw4 = daddr; 1663 } 1664 rt_add_uncached_list(rt); 1665 } 1666 } else 1667 rt_add_uncached_list(rt); 1668 1669 #ifdef CONFIG_IP_ROUTE_CLASSID 1670 #ifdef CONFIG_IP_MULTIPLE_TABLES 1671 set_class_tag(rt, res->tclassid); 1672 #endif 1673 set_class_tag(rt, itag); 1674 #endif 1675 } 1676 1677 struct rtable *rt_dst_alloc(struct net_device *dev, 1678 unsigned int flags, u16 type, 1679 bool noxfrm) 1680 { 1681 struct rtable *rt; 1682 1683 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1684 (noxfrm ? DST_NOXFRM : 0)); 1685 1686 if (rt) { 1687 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1688 rt->rt_flags = flags; 1689 rt->rt_type = type; 1690 rt->rt_is_input = 0; 1691 rt->rt_iif = 0; 1692 rt->rt_pmtu = 0; 1693 rt->rt_mtu_locked = 0; 1694 rt->rt_uses_gateway = 0; 1695 rt->rt_gw_family = 0; 1696 rt->rt_gw4 = 0; 1697 1698 rt->dst.output = ip_output; 1699 if (flags & RTCF_LOCAL) 1700 rt->dst.input = ip_local_deliver; 1701 } 1702 1703 return rt; 1704 } 1705 EXPORT_SYMBOL(rt_dst_alloc); 1706 1707 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1708 { 1709 struct rtable *new_rt; 1710 1711 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1712 rt->dst.flags); 1713 1714 if (new_rt) { 1715 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1716 new_rt->rt_flags = rt->rt_flags; 1717 new_rt->rt_type = rt->rt_type; 1718 new_rt->rt_is_input = rt->rt_is_input; 1719 new_rt->rt_iif = rt->rt_iif; 1720 new_rt->rt_pmtu = rt->rt_pmtu; 1721 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1722 new_rt->rt_gw_family = rt->rt_gw_family; 1723 if (rt->rt_gw_family == AF_INET) 1724 new_rt->rt_gw4 = rt->rt_gw4; 1725 else if (rt->rt_gw_family == AF_INET6) 1726 new_rt->rt_gw6 = rt->rt_gw6; 1727 1728 new_rt->dst.input = READ_ONCE(rt->dst.input); 1729 new_rt->dst.output = READ_ONCE(rt->dst.output); 1730 new_rt->dst.error = rt->dst.error; 1731 new_rt->dst.lastuse = jiffies; 1732 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1733 } 1734 return new_rt; 1735 } 1736 1737 /* called in rcu_read_lock() section */ 1738 enum skb_drop_reason 1739 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1740 dscp_t dscp, struct net_device *dev, 1741 struct in_device *in_dev, u32 *itag) 1742 { 1743 enum skb_drop_reason reason; 1744 1745 /* Primary sanity checks. */ 1746 if (!in_dev) 1747 return SKB_DROP_REASON_NOT_SPECIFIED; 1748 1749 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1750 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1751 1752 if (skb->protocol != htons(ETH_P_IP)) 1753 return SKB_DROP_REASON_INVALID_PROTO; 1754 1755 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1756 return SKB_DROP_REASON_IP_LOCALNET; 1757 1758 if (ipv4_is_zeronet(saddr)) { 1759 if (!ipv4_is_local_multicast(daddr) && 1760 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1761 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1762 } else { 1763 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1764 dev, in_dev, itag); 1765 if (reason) 1766 return reason; 1767 } 1768 return SKB_NOT_DROPPED_YET; 1769 } 1770 1771 /* called in rcu_read_lock() section */ 1772 static enum skb_drop_reason 1773 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1774 dscp_t dscp, struct net_device *dev, int our) 1775 { 1776 struct in_device *in_dev = __in_dev_get_rcu(dev); 1777 unsigned int flags = RTCF_MULTICAST; 1778 enum skb_drop_reason reason; 1779 struct rtable *rth; 1780 u32 itag = 0; 1781 1782 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1783 &itag); 1784 if (reason) 1785 return reason; 1786 1787 if (our) 1788 flags |= RTCF_LOCAL; 1789 1790 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1791 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1792 1793 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1794 false); 1795 if (!rth) 1796 return SKB_DROP_REASON_NOMEM; 1797 1798 #ifdef CONFIG_IP_ROUTE_CLASSID 1799 rth->dst.tclassid = itag; 1800 #endif 1801 rth->dst.output = ip_rt_bug; 1802 rth->rt_is_input= 1; 1803 1804 #ifdef CONFIG_IP_MROUTE 1805 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1806 rth->dst.input = ip_mr_input; 1807 #endif 1808 RT_CACHE_STAT_INC(in_slow_mc); 1809 1810 skb_dst_drop(skb); 1811 skb_dst_set(skb, &rth->dst); 1812 return SKB_NOT_DROPPED_YET; 1813 } 1814 1815 1816 static void ip_handle_martian_source(struct net_device *dev, 1817 struct in_device *in_dev, 1818 struct sk_buff *skb, 1819 __be32 daddr, 1820 __be32 saddr) 1821 { 1822 RT_CACHE_STAT_INC(in_martian_src); 1823 #ifdef CONFIG_IP_ROUTE_VERBOSE 1824 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1825 /* 1826 * RFC1812 recommendation, if source is martian, 1827 * the only hint is MAC header. 1828 */ 1829 pr_warn("martian source (src=%pI4, dst=%pI4, dev=%s)\n", 1830 &saddr, &daddr, dev->name); 1831 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1832 print_hex_dump(KERN_WARNING, "ll header: ", 1833 DUMP_PREFIX_OFFSET, 16, 1, 1834 skb_mac_header(skb), 1835 dev->hard_header_len, false); 1836 } 1837 } 1838 #endif 1839 } 1840 1841 /* called in rcu_read_lock() section */ 1842 static enum skb_drop_reason 1843 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1844 struct in_device *in_dev, __be32 daddr, 1845 __be32 saddr, dscp_t dscp) 1846 { 1847 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1848 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1849 struct net_device *dev = nhc->nhc_dev; 1850 struct fib_nh_exception *fnhe; 1851 struct rtable *rth; 1852 int err; 1853 struct in_device *out_dev; 1854 bool do_cache; 1855 u32 itag = 0; 1856 1857 /* get a working reference to the output device */ 1858 out_dev = __in_dev_get_rcu(dev); 1859 if (!out_dev) { 1860 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1861 return reason; 1862 } 1863 1864 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1865 in_dev->dev, in_dev, &itag); 1866 if (err < 0) { 1867 reason = -err; 1868 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1869 saddr); 1870 1871 goto cleanup; 1872 } 1873 1874 do_cache = res->fi && !itag; 1875 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1876 skb->protocol == htons(ETH_P_IP)) { 1877 __be32 gw; 1878 1879 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1880 if (IN_DEV_SHARED_MEDIA(out_dev) || 1881 inet_addr_onlink(out_dev, saddr, gw)) 1882 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1883 } 1884 1885 if (skb->protocol != htons(ETH_P_IP)) { 1886 /* Not IP (i.e. ARP). Do not create route, if it is 1887 * invalid for proxy arp. DNAT routes are always valid. 1888 * 1889 * Proxy arp feature have been extended to allow, ARP 1890 * replies back to the same interface, to support 1891 * Private VLAN switch technologies. See arp.c. 1892 */ 1893 if (out_dev == in_dev && 1894 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1895 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1896 goto cleanup; 1897 } 1898 } 1899 1900 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1901 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1902 1903 fnhe = find_exception(nhc, daddr); 1904 if (do_cache) { 1905 if (fnhe) 1906 rth = rcu_dereference(fnhe->fnhe_rth_input); 1907 else 1908 rth = rcu_dereference(nhc->nhc_rth_input); 1909 if (rt_cache_valid(rth)) { 1910 skb_dst_set_noref(skb, &rth->dst); 1911 goto out; 1912 } 1913 } 1914 1915 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1916 IN_DEV_ORCONF(out_dev, NOXFRM)); 1917 if (!rth) { 1918 reason = SKB_DROP_REASON_NOMEM; 1919 goto cleanup; 1920 } 1921 1922 rth->rt_is_input = 1; 1923 RT_CACHE_STAT_INC(in_slow_tot); 1924 1925 rth->dst.input = ip_forward; 1926 1927 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1928 do_cache); 1929 lwtunnel_set_redirect(&rth->dst); 1930 skb_dst_set(skb, &rth->dst); 1931 out: 1932 reason = SKB_NOT_DROPPED_YET; 1933 cleanup: 1934 return reason; 1935 } 1936 1937 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1938 /* To make ICMP packets follow the right flow, the multipath hash is 1939 * calculated from the inner IP addresses. 1940 */ 1941 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1942 struct flow_keys *hash_keys) 1943 { 1944 const struct iphdr *outer_iph = ip_hdr(skb); 1945 const struct iphdr *key_iph = outer_iph; 1946 const struct iphdr *inner_iph; 1947 const struct icmphdr *icmph; 1948 struct iphdr _inner_iph; 1949 struct icmphdr _icmph; 1950 1951 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1952 goto out; 1953 1954 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1955 goto out; 1956 1957 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1958 &_icmph); 1959 if (!icmph) 1960 goto out; 1961 1962 if (!icmp_is_err(icmph->type)) 1963 goto out; 1964 1965 inner_iph = skb_header_pointer(skb, 1966 outer_iph->ihl * 4 + sizeof(_icmph), 1967 sizeof(_inner_iph), &_inner_iph); 1968 if (!inner_iph) 1969 goto out; 1970 1971 key_iph = inner_iph; 1972 out: 1973 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1974 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1975 } 1976 1977 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1978 const struct sk_buff *skb, 1979 bool *p_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 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1985 return 0; 1986 1987 memset(&hash_keys, 0, sizeof(hash_keys)); 1988 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1989 1990 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1991 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1992 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1993 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1994 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1996 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1998 hash_keys.ports.src = keys.ports.src; 1999 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2000 hash_keys.ports.dst = keys.ports.dst; 2001 2002 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 2003 return fib_multipath_hash_from_keys(net, &hash_keys); 2004 } 2005 2006 static u32 fib_multipath_custom_hash_inner(const struct net *net, 2007 const struct sk_buff *skb, 2008 bool has_inner) 2009 { 2010 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2011 struct flow_keys keys, hash_keys; 2012 2013 /* We assume the packet carries an encapsulation, but if none was 2014 * encountered during dissection of the outer flow, then there is no 2015 * point in calling the flow dissector again. 2016 */ 2017 if (!has_inner) 2018 return 0; 2019 2020 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 2021 return 0; 2022 2023 memset(&hash_keys, 0, sizeof(hash_keys)); 2024 skb_flow_dissect_flow_keys(skb, &keys, 0); 2025 2026 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 2027 return 0; 2028 2029 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2030 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2031 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2032 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2033 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2034 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2035 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2036 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2037 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2038 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2039 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2040 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2041 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2042 hash_keys.tags.flow_label = keys.tags.flow_label; 2043 } 2044 2045 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2046 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2047 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2048 hash_keys.ports.src = keys.ports.src; 2049 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2050 hash_keys.ports.dst = keys.ports.dst; 2051 2052 return fib_multipath_hash_from_keys(net, &hash_keys); 2053 } 2054 2055 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2056 const struct sk_buff *skb) 2057 { 2058 u32 mhash, mhash_inner; 2059 bool has_inner = true; 2060 2061 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2062 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2063 2064 return jhash_2words(mhash, mhash_inner, 0); 2065 } 2066 2067 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2068 const struct flowi4 *fl4) 2069 { 2070 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2071 struct flow_keys hash_keys; 2072 2073 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2074 return 0; 2075 2076 memset(&hash_keys, 0, sizeof(hash_keys)); 2077 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2078 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2079 hash_keys.addrs.v4addrs.src = fl4->saddr; 2080 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2081 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2082 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2083 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2084 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2085 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2086 hash_keys.ports.src = (__force __be16)get_random_u16(); 2087 else 2088 hash_keys.ports.src = fl4->fl4_sport; 2089 } 2090 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2091 hash_keys.ports.dst = fl4->fl4_dport; 2092 2093 return fib_multipath_hash_from_keys(net, &hash_keys); 2094 } 2095 2096 /* if skb is set it will be used and fl4 can be NULL */ 2097 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2098 const struct sk_buff *skb, struct flow_keys *flkeys) 2099 { 2100 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2101 struct flow_keys hash_keys; 2102 u32 mhash = 0; 2103 2104 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2105 case 0: 2106 memset(&hash_keys, 0, sizeof(hash_keys)); 2107 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2108 if (skb) { 2109 ip_multipath_l3_keys(skb, &hash_keys); 2110 } else { 2111 hash_keys.addrs.v4addrs.src = fl4->saddr; 2112 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2113 } 2114 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2115 break; 2116 case 1: 2117 /* skb is currently provided only when forwarding */ 2118 if (skb) { 2119 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2120 struct flow_keys keys; 2121 2122 /* short-circuit if we already have L4 hash present */ 2123 if (skb->l4_hash) 2124 return skb_get_hash_raw(skb) >> 1; 2125 2126 memset(&hash_keys, 0, sizeof(hash_keys)); 2127 2128 if (!flkeys) { 2129 skb_flow_dissect_flow_keys(skb, &keys, flag); 2130 flkeys = &keys; 2131 } 2132 2133 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2134 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2135 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2136 hash_keys.ports.src = flkeys->ports.src; 2137 hash_keys.ports.dst = flkeys->ports.dst; 2138 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2139 } else { 2140 memset(&hash_keys, 0, sizeof(hash_keys)); 2141 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2142 hash_keys.addrs.v4addrs.src = fl4->saddr; 2143 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2144 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2145 hash_keys.ports.src = (__force __be16)get_random_u16(); 2146 else 2147 hash_keys.ports.src = fl4->fl4_sport; 2148 hash_keys.ports.dst = fl4->fl4_dport; 2149 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2150 } 2151 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2152 break; 2153 case 2: 2154 memset(&hash_keys, 0, sizeof(hash_keys)); 2155 /* skb is currently provided only when forwarding */ 2156 if (skb) { 2157 struct flow_keys keys; 2158 2159 skb_flow_dissect_flow_keys(skb, &keys, 0); 2160 /* Inner can be v4 or v6 */ 2161 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2162 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2163 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2164 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2165 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2166 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2167 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2168 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2169 hash_keys.tags.flow_label = keys.tags.flow_label; 2170 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2171 } else { 2172 /* Same as case 0 */ 2173 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2174 ip_multipath_l3_keys(skb, &hash_keys); 2175 } 2176 } else { 2177 /* Same as case 0 */ 2178 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2179 hash_keys.addrs.v4addrs.src = fl4->saddr; 2180 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2181 } 2182 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2183 break; 2184 case 3: 2185 if (skb) 2186 mhash = fib_multipath_custom_hash_skb(net, skb); 2187 else 2188 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2189 break; 2190 } 2191 2192 if (multipath_hash) 2193 mhash = jhash_2words(mhash, multipath_hash, 0); 2194 2195 return mhash >> 1; 2196 } 2197 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2198 2199 static enum skb_drop_reason 2200 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2201 struct in_device *in_dev, __be32 daddr, 2202 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2203 { 2204 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2205 if (res->fi && fib_info_num_path(res->fi) > 1) { 2206 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2207 2208 fib_select_multipath(res, h, NULL); 2209 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2210 } 2211 #endif 2212 2213 /* create a routing cache entry */ 2214 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2215 } 2216 2217 /* Implements all the saddr-related checks as ip_route_input_slow(), 2218 * assuming daddr is valid and the destination is not a local broadcast one. 2219 * Uses the provided hint instead of performing a route lookup. 2220 */ 2221 enum skb_drop_reason 2222 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2223 dscp_t dscp, struct net_device *dev, 2224 const struct sk_buff *hint) 2225 { 2226 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2227 struct in_device *in_dev = __in_dev_get_rcu(dev); 2228 struct rtable *rt = skb_rtable(hint); 2229 struct net *net = dev_net(dev); 2230 u32 tag = 0; 2231 2232 if (!in_dev) 2233 return reason; 2234 2235 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2236 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2237 goto martian_source; 2238 } 2239 2240 if (ipv4_is_zeronet(saddr)) { 2241 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2242 goto martian_source; 2243 } 2244 2245 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2246 reason = SKB_DROP_REASON_IP_LOCALNET; 2247 goto martian_source; 2248 } 2249 2250 if (!(rt->rt_flags & RTCF_LOCAL)) 2251 goto skip_validate_source; 2252 2253 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2254 in_dev, &tag); 2255 if (reason) 2256 goto martian_source; 2257 2258 skip_validate_source: 2259 skb_dst_copy(skb, hint); 2260 return SKB_NOT_DROPPED_YET; 2261 2262 martian_source: 2263 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2264 return reason; 2265 } 2266 2267 /* get device for dst_alloc with local routes */ 2268 static struct net_device *ip_rt_get_dev(struct net *net, 2269 const struct fib_result *res) 2270 { 2271 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2272 struct net_device *dev = NULL; 2273 2274 if (nhc) 2275 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2276 2277 return dev ? : net->loopback_dev; 2278 } 2279 2280 /* 2281 * NOTE. We drop all the packets that has local source 2282 * addresses, because every properly looped back packet 2283 * must have correct destination already attached by output routine. 2284 * Changes in the enforced policies must be applied also to 2285 * ip_route_use_hint(). 2286 * 2287 * Such approach solves two big problems: 2288 * 1. Not simplex devices are handled properly. 2289 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2290 * called with rcu_read_lock() 2291 */ 2292 2293 static enum skb_drop_reason 2294 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2295 dscp_t dscp, struct net_device *dev, 2296 struct fib_result *res) 2297 { 2298 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2299 struct in_device *in_dev = __in_dev_get_rcu(dev); 2300 struct flow_keys *flkeys = NULL, _flkeys; 2301 struct net *net = dev_net(dev); 2302 struct ip_tunnel_info *tun_info; 2303 int err = -EINVAL; 2304 unsigned int flags = 0; 2305 u32 itag = 0; 2306 struct rtable *rth; 2307 struct flowi4 fl4; 2308 bool do_cache = true; 2309 2310 /* IP on this device is disabled. */ 2311 2312 if (!in_dev) 2313 goto out; 2314 2315 /* Check for the most weird martians, which can be not detected 2316 * by fib_lookup. 2317 */ 2318 2319 tun_info = skb_tunnel_info(skb); 2320 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2321 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2322 else 2323 fl4.flowi4_tun_key.tun_id = 0; 2324 skb_dst_drop(skb); 2325 2326 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2327 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2328 goto martian_source; 2329 } 2330 2331 res->fi = NULL; 2332 res->table = NULL; 2333 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2334 goto brd_input; 2335 2336 /* Accept zero addresses only to limited broadcast; 2337 * I even do not know to fix it or not. Waiting for complains :-) 2338 */ 2339 if (ipv4_is_zeronet(saddr)) { 2340 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2341 goto martian_source; 2342 } 2343 2344 if (ipv4_is_zeronet(daddr)) { 2345 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2346 goto martian_destination; 2347 } 2348 2349 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2350 * and call it once if daddr or/and saddr are loopback addresses 2351 */ 2352 if (ipv4_is_loopback(daddr)) { 2353 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2354 reason = SKB_DROP_REASON_IP_LOCALNET; 2355 goto martian_destination; 2356 } 2357 } else if (ipv4_is_loopback(saddr)) { 2358 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2359 reason = SKB_DROP_REASON_IP_LOCALNET; 2360 goto martian_source; 2361 } 2362 } 2363 2364 /* 2365 * Now we are ready to route packet. 2366 */ 2367 fl4.flowi4_l3mdev = 0; 2368 fl4.flowi4_oif = 0; 2369 fl4.flowi4_iif = dev->ifindex; 2370 fl4.flowi4_mark = skb->mark; 2371 fl4.flowi4_dscp = dscp; 2372 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2373 fl4.flowi4_flags = 0; 2374 fl4.daddr = daddr; 2375 fl4.saddr = saddr; 2376 fl4.flowi4_uid = sock_net_uid(net, NULL); 2377 fl4.flowi4_multipath_hash = 0; 2378 2379 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2380 flkeys = &_flkeys; 2381 } else { 2382 fl4.flowi4_proto = 0; 2383 fl4.fl4_sport = 0; 2384 fl4.fl4_dport = 0; 2385 } 2386 2387 err = fib_lookup(net, &fl4, res, 0); 2388 if (err != 0) { 2389 if (!IN_DEV_FORWARD(in_dev)) 2390 err = -EHOSTUNREACH; 2391 goto no_route; 2392 } 2393 2394 if (res->type == RTN_BROADCAST) { 2395 if (IN_DEV_BFORWARD(in_dev)) 2396 goto make_route; 2397 /* not do cache if bc_forwarding is enabled */ 2398 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2399 do_cache = false; 2400 goto brd_input; 2401 } 2402 2403 err = -EINVAL; 2404 if (res->type == RTN_LOCAL) { 2405 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2406 0, dev, in_dev, &itag); 2407 if (reason) 2408 goto martian_source; 2409 goto local_input; 2410 } 2411 2412 if (!IN_DEV_FORWARD(in_dev)) { 2413 err = -EHOSTUNREACH; 2414 goto no_route; 2415 } 2416 if (res->type != RTN_UNICAST) { 2417 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2418 goto martian_destination; 2419 } 2420 2421 make_route: 2422 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2423 flkeys); 2424 2425 out: 2426 return reason; 2427 2428 brd_input: 2429 if (skb->protocol != htons(ETH_P_IP)) { 2430 reason = SKB_DROP_REASON_INVALID_PROTO; 2431 goto out; 2432 } 2433 2434 if (!ipv4_is_zeronet(saddr)) { 2435 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2436 dev, in_dev, &itag); 2437 if (reason) 2438 goto martian_source; 2439 } 2440 flags |= RTCF_BROADCAST; 2441 res->type = RTN_BROADCAST; 2442 RT_CACHE_STAT_INC(in_brd); 2443 2444 local_input: 2445 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2446 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2447 2448 do_cache &= res->fi && !itag; 2449 if (do_cache) { 2450 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2451 2452 rth = rcu_dereference(nhc->nhc_rth_input); 2453 if (rt_cache_valid(rth)) { 2454 skb_dst_set_noref(skb, &rth->dst); 2455 reason = SKB_NOT_DROPPED_YET; 2456 goto out; 2457 } 2458 } 2459 2460 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2461 flags | RTCF_LOCAL, res->type, false); 2462 if (!rth) 2463 goto e_nobufs; 2464 2465 rth->dst.output= ip_rt_bug; 2466 #ifdef CONFIG_IP_ROUTE_CLASSID 2467 rth->dst.tclassid = itag; 2468 #endif 2469 rth->rt_is_input = 1; 2470 2471 RT_CACHE_STAT_INC(in_slow_tot); 2472 if (res->type == RTN_UNREACHABLE) { 2473 rth->dst.input= ip_error; 2474 rth->dst.error= -err; 2475 rth->rt_flags &= ~RTCF_LOCAL; 2476 } 2477 2478 if (do_cache) { 2479 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2480 2481 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2482 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2483 WARN_ON(rth->dst.input == lwtunnel_input); 2484 rth->dst.lwtstate->orig_input = rth->dst.input; 2485 rth->dst.input = lwtunnel_input; 2486 } 2487 2488 if (unlikely(!rt_cache_route(nhc, rth))) 2489 rt_add_uncached_list(rth); 2490 } 2491 skb_dst_set(skb, &rth->dst); 2492 reason = SKB_NOT_DROPPED_YET; 2493 goto out; 2494 2495 no_route: 2496 RT_CACHE_STAT_INC(in_no_route); 2497 res->type = RTN_UNREACHABLE; 2498 res->fi = NULL; 2499 res->table = NULL; 2500 goto local_input; 2501 2502 /* 2503 * Do not cache martian addresses: they should be logged (RFC1812) 2504 */ 2505 martian_destination: 2506 RT_CACHE_STAT_INC(in_martian_dst); 2507 #ifdef CONFIG_IP_ROUTE_VERBOSE 2508 if (IN_DEV_LOG_MARTIANS(in_dev)) 2509 net_warn_ratelimited("martian destination (src=%pI4, dst=%pI4, dev=%s)\n", 2510 &saddr, &daddr, dev->name); 2511 #endif 2512 goto out; 2513 2514 e_nobufs: 2515 reason = SKB_DROP_REASON_NOMEM; 2516 goto out; 2517 2518 martian_source: 2519 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2520 goto out; 2521 } 2522 2523 /* called with rcu_read_lock held */ 2524 static enum skb_drop_reason 2525 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2526 dscp_t dscp, struct net_device *dev, 2527 struct fib_result *res) 2528 { 2529 /* Multicast recognition logic is moved from route cache to here. 2530 * The problem was that too many Ethernet cards have broken/missing 2531 * hardware multicast filters :-( As result the host on multicasting 2532 * network acquires a lot of useless route cache entries, sort of 2533 * SDR messages from all the world. Now we try to get rid of them. 2534 * Really, provided software IP multicast filter is organized 2535 * reasonably (at least, hashed), it does not result in a slowdown 2536 * comparing with route cache reject entries. 2537 * Note, that multicast routers are not affected, because 2538 * route cache entry is created eventually. 2539 */ 2540 if (ipv4_is_multicast(daddr)) { 2541 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2542 struct in_device *in_dev = __in_dev_get_rcu(dev); 2543 int our = 0; 2544 2545 if (!in_dev) 2546 return reason; 2547 2548 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2549 ip_hdr(skb)->protocol); 2550 2551 /* check l3 master if no match yet */ 2552 if (!our && netif_is_l3_slave(dev)) { 2553 struct in_device *l3_in_dev; 2554 2555 l3_in_dev = __in_dev_get_rcu(skb->dev); 2556 if (l3_in_dev) 2557 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2558 ip_hdr(skb)->protocol); 2559 } 2560 2561 if (our 2562 #ifdef CONFIG_IP_MROUTE 2563 || 2564 (!ipv4_is_local_multicast(daddr) && 2565 IN_DEV_MFORWARD(in_dev)) 2566 #endif 2567 ) { 2568 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2569 dev, our); 2570 } 2571 return reason; 2572 } 2573 2574 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2575 } 2576 2577 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2578 __be32 saddr, dscp_t dscp, 2579 struct net_device *dev) 2580 { 2581 enum skb_drop_reason reason; 2582 struct fib_result res; 2583 2584 rcu_read_lock(); 2585 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2586 rcu_read_unlock(); 2587 2588 return reason; 2589 } 2590 EXPORT_SYMBOL(ip_route_input_noref); 2591 2592 /* called with rcu_read_lock() */ 2593 static struct rtable *__mkroute_output(const struct fib_result *res, 2594 const struct flowi4 *fl4, int orig_oif, 2595 struct net_device *dev_out, 2596 unsigned int flags) 2597 { 2598 struct fib_info *fi = res->fi; 2599 struct fib_nh_exception *fnhe; 2600 struct in_device *in_dev; 2601 u16 type = res->type; 2602 struct rtable *rth; 2603 bool do_cache; 2604 2605 in_dev = __in_dev_get_rcu(dev_out); 2606 if (!in_dev) 2607 return ERR_PTR(-EINVAL); 2608 2609 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2610 if (ipv4_is_loopback(fl4->saddr) && 2611 !(dev_out->flags & IFF_LOOPBACK) && 2612 !netif_is_l3_master(dev_out)) 2613 return ERR_PTR(-EINVAL); 2614 2615 if (ipv4_is_lbcast(fl4->daddr)) { 2616 type = RTN_BROADCAST; 2617 2618 /* reset fi to prevent gateway resolution */ 2619 fi = NULL; 2620 } else if (ipv4_is_multicast(fl4->daddr)) { 2621 type = RTN_MULTICAST; 2622 } else if (ipv4_is_zeronet(fl4->daddr)) { 2623 return ERR_PTR(-EINVAL); 2624 } 2625 2626 if (dev_out->flags & IFF_LOOPBACK) 2627 flags |= RTCF_LOCAL; 2628 2629 do_cache = true; 2630 if (type == RTN_BROADCAST) { 2631 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2632 } else if (type == RTN_MULTICAST) { 2633 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2634 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2635 fl4->flowi4_proto)) 2636 flags &= ~RTCF_LOCAL; 2637 else 2638 do_cache = false; 2639 /* If multicast route do not exist use 2640 * default one, but do not gateway in this case. 2641 * Yes, it is hack. 2642 */ 2643 if (fi && res->prefixlen < 4) 2644 fi = NULL; 2645 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2646 (orig_oif != dev_out->ifindex)) { 2647 /* For local routes that require a particular output interface 2648 * we do not want to cache the result. Caching the result 2649 * causes incorrect behaviour when there are multiple source 2650 * addresses on the interface, the end result being that if the 2651 * intended recipient is waiting on that interface for the 2652 * packet he won't receive it because it will be delivered on 2653 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2654 * be set to the loopback interface as well. 2655 */ 2656 do_cache = false; 2657 } 2658 2659 fnhe = NULL; 2660 do_cache &= fi != NULL; 2661 if (fi) { 2662 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2663 struct rtable __rcu **prth; 2664 2665 fnhe = find_exception(nhc, fl4->daddr); 2666 if (!do_cache) 2667 goto add; 2668 if (fnhe) { 2669 prth = &fnhe->fnhe_rth_output; 2670 } else { 2671 if (unlikely(fl4->flowi4_flags & 2672 FLOWI_FLAG_KNOWN_NH && 2673 !(nhc->nhc_gw_family && 2674 nhc->nhc_scope == RT_SCOPE_LINK))) { 2675 do_cache = false; 2676 goto add; 2677 } 2678 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2679 } 2680 rth = rcu_dereference(*prth); 2681 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2682 return rth; 2683 } 2684 2685 add: 2686 rth = rt_dst_alloc(dev_out, flags, type, 2687 IN_DEV_ORCONF(in_dev, NOXFRM)); 2688 if (!rth) 2689 return ERR_PTR(-ENOBUFS); 2690 2691 rth->rt_iif = orig_oif; 2692 2693 RT_CACHE_STAT_INC(out_slow_tot); 2694 2695 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2696 if (flags & RTCF_LOCAL && 2697 !(dev_out->flags & IFF_LOOPBACK)) { 2698 rth->dst.output = ip_mc_output; 2699 RT_CACHE_STAT_INC(out_slow_mc); 2700 } 2701 #ifdef CONFIG_IP_MROUTE 2702 if (type == RTN_MULTICAST) { 2703 if (IN_DEV_MFORWARD(in_dev) && 2704 !ipv4_is_local_multicast(fl4->daddr)) { 2705 rth->dst.input = ip_mr_input; 2706 rth->dst.output = ip_mr_output; 2707 } 2708 } 2709 #endif 2710 } 2711 2712 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2713 lwtunnel_set_redirect(&rth->dst); 2714 2715 return rth; 2716 } 2717 2718 /* 2719 * Major route resolver routine. 2720 */ 2721 2722 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2723 const struct sk_buff *skb) 2724 { 2725 struct fib_result res = { 2726 .type = RTN_UNSPEC, 2727 .fi = NULL, 2728 .table = NULL, 2729 .tclassid = 0, 2730 }; 2731 struct rtable *rth; 2732 2733 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2734 2735 rcu_read_lock(); 2736 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2737 rcu_read_unlock(); 2738 2739 return rth; 2740 } 2741 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2742 2743 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2744 struct fib_result *res, 2745 const struct sk_buff *skb) 2746 { 2747 struct net_device *dev_out = NULL; 2748 int orig_oif = fl4->flowi4_oif; 2749 unsigned int flags = 0; 2750 struct rtable *rth; 2751 int err; 2752 2753 if (fl4->saddr) { 2754 if (ipv4_is_multicast(fl4->saddr) || 2755 ipv4_is_lbcast(fl4->saddr)) { 2756 rth = ERR_PTR(-EINVAL); 2757 goto out; 2758 } 2759 2760 rth = ERR_PTR(-ENETUNREACH); 2761 2762 /* I removed check for oif == dev_out->oif here. 2763 * It was wrong for two reasons: 2764 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2765 * is assigned to multiple interfaces. 2766 * 2. Moreover, we are allowed to send packets with saddr 2767 * of another iface. --ANK 2768 */ 2769 2770 if (fl4->flowi4_oif == 0 && 2771 (ipv4_is_multicast(fl4->daddr) || 2772 ipv4_is_lbcast(fl4->daddr))) { 2773 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2774 dev_out = __ip_dev_find(net, fl4->saddr, false); 2775 if (!dev_out) 2776 goto out; 2777 2778 /* Special hack: user can direct multicasts 2779 * and limited broadcast via necessary interface 2780 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2781 * This hack is not just for fun, it allows 2782 * vic,vat and friends to work. 2783 * They bind socket to loopback, set ttl to zero 2784 * and expect that it will work. 2785 * From the viewpoint of routing cache they are broken, 2786 * because we are not allowed to build multicast path 2787 * with loopback source addr (look, routing cache 2788 * cannot know, that ttl is zero, so that packet 2789 * will not leave this host and route is valid). 2790 * Luckily, this hack is good workaround. 2791 */ 2792 2793 fl4->flowi4_oif = dev_out->ifindex; 2794 goto make_route; 2795 } 2796 2797 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2798 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2799 if (!__ip_dev_find(net, fl4->saddr, false)) 2800 goto out; 2801 } 2802 } 2803 2804 2805 if (fl4->flowi4_oif) { 2806 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2807 rth = ERR_PTR(-ENODEV); 2808 if (!dev_out) 2809 goto out; 2810 2811 /* RACE: Check return value of inet_select_addr instead. */ 2812 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2813 rth = ERR_PTR(-ENETUNREACH); 2814 goto out; 2815 } 2816 if (ipv4_is_local_multicast(fl4->daddr) || 2817 ipv4_is_lbcast(fl4->daddr) || 2818 fl4->flowi4_proto == IPPROTO_IGMP) { 2819 if (!fl4->saddr) 2820 fl4->saddr = inet_select_addr(dev_out, 0, 2821 RT_SCOPE_LINK); 2822 goto make_route; 2823 } 2824 if (!fl4->saddr) { 2825 if (ipv4_is_multicast(fl4->daddr)) 2826 fl4->saddr = inet_select_addr(dev_out, 0, 2827 fl4->flowi4_scope); 2828 else if (!fl4->daddr) 2829 fl4->saddr = inet_select_addr(dev_out, 0, 2830 RT_SCOPE_HOST); 2831 } 2832 } 2833 2834 if (!fl4->daddr) { 2835 fl4->daddr = fl4->saddr; 2836 if (!fl4->daddr) 2837 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2838 dev_out = net->loopback_dev; 2839 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2840 res->type = RTN_LOCAL; 2841 flags |= RTCF_LOCAL; 2842 goto make_route; 2843 } 2844 2845 err = fib_lookup(net, fl4, res, 0); 2846 if (err) { 2847 res->fi = NULL; 2848 res->table = NULL; 2849 if (fl4->flowi4_oif && 2850 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2851 /* Apparently, routing tables are wrong. Assume, 2852 * that the destination is on link. 2853 * 2854 * WHY? DW. 2855 * Because we are allowed to send to iface 2856 * even if it has NO routes and NO assigned 2857 * addresses. When oif is specified, routing 2858 * tables are looked up with only one purpose: 2859 * to catch if destination is gatewayed, rather than 2860 * direct. Moreover, if MSG_DONTROUTE is set, 2861 * we send packet, ignoring both routing tables 2862 * and ifaddr state. --ANK 2863 * 2864 * 2865 * We could make it even if oif is unknown, 2866 * likely IPv6, but we do not. 2867 */ 2868 2869 if (fl4->saddr == 0) 2870 fl4->saddr = inet_select_addr(dev_out, 0, 2871 RT_SCOPE_LINK); 2872 res->type = RTN_UNICAST; 2873 goto make_route; 2874 } 2875 rth = ERR_PTR(err); 2876 goto out; 2877 } 2878 2879 if (res->type == RTN_LOCAL) { 2880 if (!fl4->saddr) { 2881 if (res->fi->fib_prefsrc) 2882 fl4->saddr = res->fi->fib_prefsrc; 2883 else 2884 fl4->saddr = fl4->daddr; 2885 } 2886 2887 /* L3 master device is the loopback for that domain */ 2888 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2889 net->loopback_dev; 2890 2891 /* make sure orig_oif points to fib result device even 2892 * though packet rx/tx happens over loopback or l3mdev 2893 */ 2894 orig_oif = FIB_RES_OIF(*res); 2895 2896 fl4->flowi4_oif = dev_out->ifindex; 2897 flags |= RTCF_LOCAL; 2898 goto make_route; 2899 } 2900 2901 fib_select_path(net, res, fl4, skb); 2902 2903 dev_out = FIB_RES_DEV(*res); 2904 2905 make_route: 2906 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2907 2908 out: 2909 return rth; 2910 } 2911 2912 static struct dst_ops ipv4_dst_blackhole_ops = { 2913 .family = AF_INET, 2914 .default_advmss = ipv4_default_advmss, 2915 .neigh_lookup = ipv4_neigh_lookup, 2916 .check = dst_blackhole_check, 2917 .cow_metrics = dst_blackhole_cow_metrics, 2918 .update_pmtu = dst_blackhole_update_pmtu, 2919 .redirect = dst_blackhole_redirect, 2920 .mtu = dst_blackhole_mtu, 2921 }; 2922 2923 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2924 { 2925 struct rtable *ort = dst_rtable(dst_orig); 2926 struct rtable *rt; 2927 2928 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2929 if (rt) { 2930 struct dst_entry *new = &rt->dst; 2931 2932 new->__use = 1; 2933 new->input = dst_discard; 2934 new->output = dst_discard_out; 2935 2936 new->dev = net->loopback_dev; 2937 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2938 2939 rt->rt_is_input = ort->rt_is_input; 2940 rt->rt_iif = ort->rt_iif; 2941 rt->rt_pmtu = ort->rt_pmtu; 2942 rt->rt_mtu_locked = ort->rt_mtu_locked; 2943 2944 rt->rt_genid = rt_genid_ipv4(net); 2945 rt->rt_flags = ort->rt_flags; 2946 rt->rt_type = ort->rt_type; 2947 rt->rt_uses_gateway = ort->rt_uses_gateway; 2948 rt->rt_gw_family = ort->rt_gw_family; 2949 if (rt->rt_gw_family == AF_INET) 2950 rt->rt_gw4 = ort->rt_gw4; 2951 else if (rt->rt_gw_family == AF_INET6) 2952 rt->rt_gw6 = ort->rt_gw6; 2953 } 2954 2955 dst_release(dst_orig); 2956 2957 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2958 } 2959 2960 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2961 const struct sock *sk) 2962 { 2963 struct rtable *rt = __ip_route_output_key(net, flp4); 2964 2965 if (IS_ERR(rt)) 2966 return rt; 2967 2968 if (flp4->flowi4_proto) { 2969 flp4->flowi4_oif = rt->dst.dev->ifindex; 2970 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2971 flowi4_to_flowi(flp4), 2972 sk, 0)); 2973 } 2974 2975 return rt; 2976 } 2977 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2978 2979 /* called with rcu_read_lock held */ 2980 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2981 struct rtable *rt, u32 table_id, dscp_t dscp, 2982 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2983 u32 seq, unsigned int flags) 2984 { 2985 struct rtmsg *r; 2986 struct nlmsghdr *nlh; 2987 unsigned long expires = 0; 2988 u32 error; 2989 u32 metrics[RTAX_MAX]; 2990 2991 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2992 if (!nlh) 2993 return -EMSGSIZE; 2994 2995 r = nlmsg_data(nlh); 2996 r->rtm_family = AF_INET; 2997 r->rtm_dst_len = 32; 2998 r->rtm_src_len = 0; 2999 r->rtm_tos = inet_dscp_to_dsfield(dscp); 3000 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 3001 if (nla_put_u32(skb, RTA_TABLE, table_id)) 3002 goto nla_put_failure; 3003 r->rtm_type = rt->rt_type; 3004 r->rtm_scope = RT_SCOPE_UNIVERSE; 3005 r->rtm_protocol = RTPROT_UNSPEC; 3006 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 3007 if (rt->rt_flags & RTCF_NOTIFY) 3008 r->rtm_flags |= RTM_F_NOTIFY; 3009 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 3010 r->rtm_flags |= RTCF_DOREDIRECT; 3011 3012 if (nla_put_in_addr(skb, RTA_DST, dst)) 3013 goto nla_put_failure; 3014 if (src) { 3015 r->rtm_src_len = 32; 3016 if (nla_put_in_addr(skb, RTA_SRC, src)) 3017 goto nla_put_failure; 3018 } 3019 if (rt->dst.dev && 3020 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 3021 goto nla_put_failure; 3022 if (lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 3023 goto nla_put_failure; 3024 #ifdef CONFIG_IP_ROUTE_CLASSID 3025 if (rt->dst.tclassid && 3026 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 3027 goto nla_put_failure; 3028 #endif 3029 if (fl4 && !rt_is_input_route(rt) && 3030 fl4->saddr != src) { 3031 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 3032 goto nla_put_failure; 3033 } 3034 if (rt->rt_uses_gateway) { 3035 if (rt->rt_gw_family == AF_INET && 3036 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3037 goto nla_put_failure; 3038 } else if (rt->rt_gw_family == AF_INET6) { 3039 int alen = sizeof(struct in6_addr); 3040 struct nlattr *nla; 3041 struct rtvia *via; 3042 3043 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3044 if (!nla) 3045 goto nla_put_failure; 3046 3047 via = nla_data(nla); 3048 via->rtvia_family = AF_INET6; 3049 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3050 } 3051 } 3052 3053 expires = READ_ONCE(rt->dst.expires); 3054 if (expires) { 3055 unsigned long now = jiffies; 3056 3057 if (time_before(now, expires)) 3058 expires -= now; 3059 else 3060 expires = 0; 3061 } 3062 3063 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3064 if (rt->rt_pmtu && expires) 3065 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3066 if (rt->rt_mtu_locked && expires) 3067 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3068 if (rtnetlink_put_metrics(skb, metrics) < 0) 3069 goto nla_put_failure; 3070 3071 if (fl4) { 3072 if (fl4->flowi4_mark && 3073 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3074 goto nla_put_failure; 3075 3076 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3077 nla_put_u32(skb, RTA_UID, 3078 from_kuid_munged(current_user_ns(), 3079 fl4->flowi4_uid))) 3080 goto nla_put_failure; 3081 3082 if (rt_is_input_route(rt)) { 3083 #ifdef CONFIG_IP_MROUTE 3084 if (ipv4_is_multicast(dst) && 3085 !ipv4_is_local_multicast(dst) && 3086 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3087 int err = ipmr_get_route(net, skb, 3088 fl4->saddr, fl4->daddr, 3089 r, portid); 3090 3091 if (err <= 0) { 3092 if (err == 0) 3093 return 0; 3094 goto nla_put_failure; 3095 } 3096 } else 3097 #endif 3098 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3099 goto nla_put_failure; 3100 } 3101 } 3102 3103 error = rt->dst.error; 3104 3105 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3106 goto nla_put_failure; 3107 3108 nlmsg_end(skb, nlh); 3109 return 0; 3110 3111 nla_put_failure: 3112 nlmsg_cancel(skb, nlh); 3113 return -EMSGSIZE; 3114 } 3115 3116 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3117 struct netlink_callback *cb, u32 table_id, 3118 struct fnhe_hash_bucket *bucket, int genid, 3119 int *fa_index, int fa_start, unsigned int flags) 3120 { 3121 int i; 3122 3123 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3124 struct fib_nh_exception *fnhe; 3125 3126 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3127 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3128 struct rtable *rt; 3129 int err; 3130 3131 if (*fa_index < fa_start) 3132 goto next; 3133 3134 if (fnhe->fnhe_genid != genid) 3135 goto next; 3136 3137 if (fnhe->fnhe_expires && 3138 time_after(jiffies, fnhe->fnhe_expires)) 3139 goto next; 3140 3141 rt = rcu_dereference(fnhe->fnhe_rth_input); 3142 if (!rt) 3143 rt = rcu_dereference(fnhe->fnhe_rth_output); 3144 if (!rt) 3145 goto next; 3146 3147 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3148 table_id, 0, NULL, skb, 3149 NETLINK_CB(cb->skb).portid, 3150 cb->nlh->nlmsg_seq, flags); 3151 if (err) 3152 return err; 3153 next: 3154 (*fa_index)++; 3155 } 3156 } 3157 3158 return 0; 3159 } 3160 3161 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3162 u32 table_id, struct fib_info *fi, 3163 int *fa_index, int fa_start, unsigned int flags) 3164 { 3165 struct net *net = sock_net(cb->skb->sk); 3166 int nhsel, genid = fnhe_genid(net); 3167 3168 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3169 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3170 struct fnhe_hash_bucket *bucket; 3171 int err; 3172 3173 if (!nhc) 3174 break; 3175 3176 if (nhc->nhc_flags & RTNH_F_DEAD) 3177 continue; 3178 3179 rcu_read_lock(); 3180 bucket = rcu_dereference(nhc->nhc_exceptions); 3181 err = 0; 3182 if (bucket) 3183 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3184 genid, fa_index, fa_start, 3185 flags); 3186 rcu_read_unlock(); 3187 if (err) 3188 return err; 3189 } 3190 3191 return 0; 3192 } 3193 3194 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3195 u8 ip_proto, __be16 sport, 3196 __be16 dport) 3197 { 3198 struct sk_buff *skb; 3199 struct iphdr *iph; 3200 3201 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3202 if (!skb) 3203 return NULL; 3204 3205 /* Reserve room for dummy headers, this skb can pass 3206 * through good chunk of routing engine. 3207 */ 3208 skb_reset_mac_header(skb); 3209 skb_reset_network_header(skb); 3210 skb->protocol = htons(ETH_P_IP); 3211 iph = skb_put(skb, sizeof(struct iphdr)); 3212 iph->protocol = ip_proto; 3213 iph->saddr = src; 3214 iph->daddr = dst; 3215 iph->version = 0x4; 3216 iph->frag_off = 0; 3217 iph->ihl = 0x5; 3218 skb_set_transport_header(skb, skb->len); 3219 3220 switch (iph->protocol) { 3221 case IPPROTO_UDP: { 3222 struct udphdr *udph; 3223 3224 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3225 udph->source = sport; 3226 udph->dest = dport; 3227 udp_set_len_short(udph, sizeof(struct udphdr)); 3228 udph->check = 0; 3229 break; 3230 } 3231 case IPPROTO_TCP: { 3232 struct tcphdr *tcph; 3233 3234 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3235 tcph->source = sport; 3236 tcph->dest = dport; 3237 tcph->doff = sizeof(struct tcphdr) / 4; 3238 tcph->rst = 1; 3239 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3240 src, dst, 0); 3241 break; 3242 } 3243 case IPPROTO_ICMP: { 3244 struct icmphdr *icmph; 3245 3246 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3247 icmph->type = ICMP_ECHO; 3248 icmph->code = 0; 3249 } 3250 } 3251 3252 return skb; 3253 } 3254 3255 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3256 const struct nlmsghdr *nlh, 3257 struct nlattr **tb, 3258 struct netlink_ext_ack *extack) 3259 { 3260 struct rtmsg *rtm; 3261 int i, err; 3262 3263 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3264 if (!rtm) { 3265 NL_SET_ERR_MSG(extack, 3266 "ipv4: Invalid header for route get request"); 3267 return -EINVAL; 3268 } 3269 3270 if (!netlink_strict_get_check(skb)) 3271 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3272 rtm_ipv4_policy, extack); 3273 3274 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3275 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3276 rtm->rtm_table || rtm->rtm_protocol || 3277 rtm->rtm_scope || rtm->rtm_type) { 3278 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3279 return -EINVAL; 3280 } 3281 3282 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3283 RTM_F_LOOKUP_TABLE | 3284 RTM_F_FIB_MATCH)) { 3285 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3286 return -EINVAL; 3287 } 3288 3289 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3290 rtm_ipv4_policy, extack); 3291 if (err) 3292 return err; 3293 3294 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3295 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3296 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3297 return -EINVAL; 3298 } 3299 3300 for (i = 0; i <= RTA_MAX; i++) { 3301 if (!tb[i]) 3302 continue; 3303 3304 switch (i) { 3305 case RTA_IIF: 3306 case RTA_OIF: 3307 case RTA_SRC: 3308 case RTA_DST: 3309 case RTA_IP_PROTO: 3310 case RTA_SPORT: 3311 case RTA_DPORT: 3312 case RTA_MARK: 3313 case RTA_UID: 3314 break; 3315 default: 3316 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3317 return -EINVAL; 3318 } 3319 } 3320 3321 return 0; 3322 } 3323 3324 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3325 struct netlink_ext_ack *extack) 3326 { 3327 struct net *net = sock_net(in_skb->sk); 3328 struct nlattr *tb[RTA_MAX+1]; 3329 u32 table_id = RT_TABLE_MAIN; 3330 __be16 sport = 0, dport = 0; 3331 struct fib_result res = {}; 3332 u8 ip_proto = IPPROTO_UDP; 3333 struct rtable *rt = NULL; 3334 struct sk_buff *skb; 3335 struct rtmsg *rtm; 3336 struct flowi4 fl4 = {}; 3337 __be32 dst = 0; 3338 __be32 src = 0; 3339 dscp_t dscp; 3340 kuid_t uid; 3341 u32 iif; 3342 int err; 3343 int mark; 3344 3345 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3346 if (err < 0) 3347 return err; 3348 3349 rtm = nlmsg_data(nlh); 3350 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3351 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3352 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3353 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3354 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3355 if (tb[RTA_UID]) 3356 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3357 else 3358 uid = (iif ? INVALID_UID : current_uid()); 3359 3360 if (tb[RTA_IP_PROTO]) { 3361 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3362 &ip_proto, AF_INET, extack); 3363 if (err) 3364 return err; 3365 } 3366 3367 if (tb[RTA_SPORT]) 3368 sport = nla_get_be16(tb[RTA_SPORT]); 3369 3370 if (tb[RTA_DPORT]) 3371 dport = nla_get_be16(tb[RTA_DPORT]); 3372 3373 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3374 if (!skb) 3375 return -ENOBUFS; 3376 3377 fl4.daddr = dst; 3378 fl4.saddr = src; 3379 fl4.flowi4_dscp = dscp; 3380 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3381 fl4.flowi4_mark = mark; 3382 fl4.flowi4_uid = uid; 3383 if (sport) 3384 fl4.fl4_sport = sport; 3385 if (dport) 3386 fl4.fl4_dport = dport; 3387 fl4.flowi4_proto = ip_proto; 3388 3389 rcu_read_lock(); 3390 3391 if (iif) { 3392 struct net_device *dev; 3393 3394 dev = dev_get_by_index_rcu(net, iif); 3395 if (!dev) { 3396 err = -ENODEV; 3397 goto errout_rcu; 3398 } 3399 3400 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3401 skb->dev = dev; 3402 skb->mark = mark; 3403 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3404 &res) ? -EINVAL : 0; 3405 3406 rt = skb_rtable(skb); 3407 if (err == 0 && rt->dst.error) 3408 err = -rt->dst.error; 3409 } else { 3410 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3411 skb->dev = net->loopback_dev; 3412 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3413 err = 0; 3414 if (IS_ERR(rt)) 3415 err = PTR_ERR(rt); 3416 else 3417 skb_dst_set(skb, &rt->dst); 3418 } 3419 3420 if (err) 3421 goto errout_rcu; 3422 3423 if (rtm->rtm_flags & RTM_F_NOTIFY) 3424 rt->rt_flags |= RTCF_NOTIFY; 3425 3426 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3427 table_id = res.table ? res.table->tb_id : 0; 3428 3429 /* reset skb for netlink reply msg */ 3430 skb_trim(skb, 0); 3431 skb_reset_network_header(skb); 3432 skb_reset_transport_header(skb); 3433 skb_reset_mac_header(skb); 3434 3435 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3436 struct fib_rt_info fri; 3437 3438 if (!res.fi) { 3439 err = fib_props[res.type].error; 3440 if (!err) 3441 err = -EHOSTUNREACH; 3442 goto errout_rcu; 3443 } 3444 fri.fi = res.fi; 3445 fri.tb_id = table_id; 3446 fri.dst = res.prefix; 3447 fri.dst_len = res.prefixlen; 3448 fri.dscp = res.dscp; 3449 fri.type = rt->rt_type; 3450 fri.offload = 0; 3451 fri.trap = 0; 3452 fri.offload_failed = 0; 3453 if (res.fa_head) { 3454 struct fib_alias *fa; 3455 3456 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3457 u8 slen = 32 - fri.dst_len; 3458 3459 if (fa->fa_slen == slen && 3460 fa->tb_id == fri.tb_id && 3461 fa->fa_dscp == fri.dscp && 3462 fa->fa_info == res.fi && 3463 fa->fa_type == fri.type) { 3464 fri.offload = READ_ONCE(fa->offload); 3465 fri.trap = READ_ONCE(fa->trap); 3466 fri.offload_failed = 3467 READ_ONCE(fa->offload_failed); 3468 break; 3469 } 3470 } 3471 } 3472 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3473 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3474 } else { 3475 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3476 skb, NETLINK_CB(in_skb).portid, 3477 nlh->nlmsg_seq, 0); 3478 } 3479 if (err < 0) 3480 goto errout_rcu; 3481 3482 rcu_read_unlock(); 3483 3484 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3485 3486 errout_free: 3487 return err; 3488 errout_rcu: 3489 rcu_read_unlock(); 3490 kfree_skb(skb); 3491 goto errout_free; 3492 } 3493 3494 void ip_rt_multicast_event(struct in_device *in_dev) 3495 { 3496 rt_cache_flush(dev_net(in_dev->dev)); 3497 } 3498 3499 #ifdef CONFIG_SYSCTL 3500 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3501 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3502 static int ip_rt_gc_elasticity __read_mostly = 8; 3503 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3504 3505 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3506 void *buffer, size_t *lenp, loff_t *ppos) 3507 { 3508 struct net *net = (struct net *)__ctl->extra1; 3509 3510 if (write) { 3511 rt_cache_flush(net); 3512 fnhe_genid_bump(net); 3513 return 0; 3514 } 3515 3516 return -EINVAL; 3517 } 3518 3519 static struct ctl_table ipv4_route_table[] = { 3520 { 3521 .procname = "gc_thresh", 3522 .data = &ipv4_dst_ops.gc_thresh, 3523 .maxlen = sizeof(int), 3524 .mode = 0644, 3525 .proc_handler = proc_dointvec, 3526 }, 3527 { 3528 .procname = "max_size", 3529 .data = &ip_rt_max_size, 3530 .maxlen = sizeof(int), 3531 .mode = 0644, 3532 .proc_handler = proc_dointvec, 3533 }, 3534 { 3535 /* Deprecated. Use gc_min_interval_ms */ 3536 3537 .procname = "gc_min_interval", 3538 .data = &ip_rt_gc_min_interval, 3539 .maxlen = sizeof(int), 3540 .mode = 0644, 3541 .proc_handler = proc_dointvec_jiffies, 3542 }, 3543 { 3544 .procname = "gc_min_interval_ms", 3545 .data = &ip_rt_gc_min_interval, 3546 .maxlen = sizeof(int), 3547 .mode = 0644, 3548 .proc_handler = proc_dointvec_ms_jiffies, 3549 }, 3550 { 3551 .procname = "gc_timeout", 3552 .data = &ip_rt_gc_timeout, 3553 .maxlen = sizeof(int), 3554 .mode = 0644, 3555 .proc_handler = proc_dointvec_jiffies, 3556 }, 3557 { 3558 .procname = "gc_interval", 3559 .data = &ip_rt_gc_interval, 3560 .maxlen = sizeof(int), 3561 .mode = 0644, 3562 .proc_handler = proc_dointvec_jiffies, 3563 }, 3564 { 3565 .procname = "redirect_load", 3566 .data = &ip_rt_redirect_load, 3567 .maxlen = sizeof(int), 3568 .mode = 0644, 3569 .proc_handler = proc_dointvec, 3570 }, 3571 { 3572 .procname = "redirect_number", 3573 .data = &ip_rt_redirect_number, 3574 .maxlen = sizeof(int), 3575 .mode = 0644, 3576 .proc_handler = proc_dointvec, 3577 }, 3578 { 3579 .procname = "redirect_silence", 3580 .data = &ip_rt_redirect_silence, 3581 .maxlen = sizeof(int), 3582 .mode = 0644, 3583 .proc_handler = proc_dointvec, 3584 }, 3585 { 3586 .procname = "error_cost", 3587 .data = &ip_rt_error_cost, 3588 .maxlen = sizeof(int), 3589 .mode = 0644, 3590 .proc_handler = proc_dointvec, 3591 }, 3592 { 3593 .procname = "error_burst", 3594 .data = &ip_rt_error_burst, 3595 .maxlen = sizeof(int), 3596 .mode = 0644, 3597 .proc_handler = proc_dointvec, 3598 }, 3599 { 3600 .procname = "gc_elasticity", 3601 .data = &ip_rt_gc_elasticity, 3602 .maxlen = sizeof(int), 3603 .mode = 0644, 3604 .proc_handler = proc_dointvec, 3605 }, 3606 }; 3607 3608 static const char ipv4_route_flush_procname[] = "flush"; 3609 3610 static struct ctl_table ipv4_route_netns_table[] = { 3611 { 3612 .procname = ipv4_route_flush_procname, 3613 .maxlen = sizeof(int), 3614 .mode = 0200, 3615 .proc_handler = ipv4_sysctl_rtcache_flush, 3616 }, 3617 { 3618 .procname = "min_pmtu", 3619 .data = &init_net.ipv4.ip_rt_min_pmtu, 3620 .maxlen = sizeof(int), 3621 .mode = 0644, 3622 .proc_handler = proc_dointvec_minmax, 3623 .extra1 = &ip_min_valid_pmtu, 3624 }, 3625 { 3626 .procname = "mtu_expires", 3627 .data = &init_net.ipv4.ip_rt_mtu_expires, 3628 .maxlen = sizeof(int), 3629 .mode = 0644, 3630 .proc_handler = proc_dointvec_jiffies, 3631 }, 3632 { 3633 .procname = "min_adv_mss", 3634 .data = &init_net.ipv4.ip_rt_min_advmss, 3635 .maxlen = sizeof(int), 3636 .mode = 0644, 3637 .proc_handler = proc_dointvec, 3638 }, 3639 }; 3640 3641 static __net_init int sysctl_route_net_init(struct net *net) 3642 { 3643 struct ctl_table *tbl; 3644 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3645 3646 tbl = ipv4_route_netns_table; 3647 if (!net_eq(net, &init_net)) { 3648 int i; 3649 3650 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3651 if (!tbl) 3652 goto err_dup; 3653 3654 /* Don't export non-whitelisted sysctls to unprivileged users */ 3655 if (net->user_ns != &init_user_ns) { 3656 if (tbl[0].procname != ipv4_route_flush_procname) 3657 table_size = 0; 3658 } 3659 3660 /* Update the variables to point into the current struct net 3661 * except for the first element flush 3662 */ 3663 for (i = 1; i < table_size; i++) 3664 tbl[i].data += (void *)net - (void *)&init_net; 3665 } 3666 tbl[0].extra1 = net; 3667 3668 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3669 tbl, table_size); 3670 if (!net->ipv4.route_hdr) 3671 goto err_reg; 3672 return 0; 3673 3674 err_reg: 3675 if (tbl != ipv4_route_netns_table) 3676 kfree(tbl); 3677 err_dup: 3678 return -ENOMEM; 3679 } 3680 3681 static __net_exit void sysctl_route_net_exit(struct net *net) 3682 { 3683 const struct ctl_table *tbl; 3684 3685 tbl = net->ipv4.route_hdr->ctl_table_arg; 3686 unregister_net_sysctl_table(net->ipv4.route_hdr); 3687 BUG_ON(tbl == ipv4_route_netns_table); 3688 kfree(tbl); 3689 } 3690 3691 static __net_initdata struct pernet_operations sysctl_route_ops = { 3692 .init = sysctl_route_net_init, 3693 .exit = sysctl_route_net_exit, 3694 }; 3695 #endif 3696 3697 static __net_init int netns_ip_rt_init(struct net *net) 3698 { 3699 /* Set default value for namespaceified sysctls */ 3700 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3701 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3702 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3703 return 0; 3704 } 3705 3706 static struct pernet_operations __net_initdata ip_rt_ops = { 3707 .init = netns_ip_rt_init, 3708 }; 3709 3710 static __net_init int rt_genid_init(struct net *net) 3711 { 3712 atomic_set(&net->ipv4.rt_genid, 0); 3713 atomic_set(&net->fnhe_genid, 0); 3714 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3715 return 0; 3716 } 3717 3718 static __net_initdata struct pernet_operations rt_genid_ops = { 3719 .init = rt_genid_init, 3720 }; 3721 3722 static int __net_init ipv4_inetpeer_init(struct net *net) 3723 { 3724 struct inet_peer_base *bp = kmalloc_obj(*bp); 3725 3726 if (!bp) 3727 return -ENOMEM; 3728 inet_peer_base_init(bp); 3729 net->ipv4.peers = bp; 3730 return 0; 3731 } 3732 3733 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3734 { 3735 struct inet_peer_base *bp = net->ipv4.peers; 3736 3737 net->ipv4.peers = NULL; 3738 inetpeer_invalidate_tree(bp); 3739 kfree(bp); 3740 } 3741 3742 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3743 .init = ipv4_inetpeer_init, 3744 .exit = ipv4_inetpeer_exit, 3745 }; 3746 3747 #ifdef CONFIG_IP_ROUTE_CLASSID 3748 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3749 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3750 3751 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3752 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3753 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3754 }; 3755 3756 int __init ip_rt_init(void) 3757 { 3758 void *idents_hash; 3759 int cpu; 3760 3761 /* For modern hosts, this will use 2 MB of memory */ 3762 idents_hash = alloc_large_system_hash("IP idents", 3763 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3764 0, 3765 16, /* one bucket per 64 KB */ 3766 HASH_ZERO, 3767 NULL, 3768 &ip_idents_mask, 3769 2048, 3770 256*1024); 3771 3772 ip_idents = idents_hash; 3773 3774 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3775 3776 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3777 3778 for_each_possible_cpu(cpu) { 3779 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3780 3781 INIT_LIST_HEAD(&ul->head); 3782 spin_lock_init(&ul->lock); 3783 } 3784 #ifdef CONFIG_IP_ROUTE_CLASSID 3785 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3786 if (!ip_rt_acct) 3787 panic("IP: failed to allocate ip_rt_acct\n"); 3788 #endif 3789 3790 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3791 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3792 3793 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3794 3795 if (dst_entries_init(&ipv4_dst_ops) < 0) 3796 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3797 3798 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3799 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3800 3801 ipv4_dst_ops.gc_thresh = ~0; 3802 ip_rt_max_size = INT_MAX; 3803 3804 devinet_init(); 3805 ip_fib_init(); 3806 3807 if (ip_rt_proc_init()) 3808 pr_err("Unable to create route proc files\n"); 3809 #ifdef CONFIG_XFRM 3810 xfrm_init(); 3811 xfrm4_init(); 3812 #endif 3813 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3814 3815 #ifdef CONFIG_SYSCTL 3816 register_pernet_subsys(&sysctl_route_ops); 3817 #endif 3818 register_pernet_subsys(&ip_rt_ops); 3819 register_pernet_subsys(&rt_genid_ops); 3820 register_pernet_subsys(&ipv4_inetpeer_ops); 3821 return 0; 3822 } 3823 3824 #ifdef CONFIG_SYSCTL 3825 /* 3826 * We really need to sanitize the damn ipv4 init order, then all 3827 * this nonsense will go away. 3828 */ 3829 void __init ip_static_sysctl_init(void) 3830 { 3831 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3832 } 3833 #endif 3834