1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/flow.h> 88 #include <net/inet_dscp.h> 89 #include <net/net_namespace.h> 90 #include <net/ip.h> 91 #include <net/route.h> 92 #include <net/inetpeer.h> 93 #include <net/sock.h> 94 #include <net/ip_fib.h> 95 #include <net/nexthop.h> 96 #include <net/tcp.h> 97 #include <net/icmp.h> 98 #include <net/xfrm.h> 99 #include <net/lwtunnel.h> 100 #include <net/netevent.h> 101 #include <net/rtnetlink.h> 102 #ifdef CONFIG_SYSCTL 103 #include <linux/sysctl.h> 104 #endif 105 #include <net/secure_seq.h> 106 #include <net/ip_tunnels.h> 107 108 #include "fib_lookup.h" 109 110 #define RT_GC_TIMEOUT (300*HZ) 111 112 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 113 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 114 #define DEFAULT_MIN_ADVMSS 256 115 static int ip_rt_max_size; 116 static int ip_rt_redirect_number __read_mostly = 9; 117 static int ip_rt_redirect_load __read_mostly = HZ / 50; 118 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 119 static int ip_rt_error_cost __read_mostly = HZ; 120 static int ip_rt_error_burst __read_mostly = 5 * HZ; 121 122 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 123 124 /* 125 * Interface to generic destination cache. 126 */ 127 128 INDIRECT_CALLABLE_SCOPE 129 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 130 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 131 INDIRECT_CALLABLE_SCOPE 132 unsigned int ipv4_mtu(const struct dst_entry *dst); 133 static void ipv4_negative_advice(struct sock *sk, 134 struct dst_entry *dst); 135 static void ipv4_link_failure(struct sk_buff *skb); 136 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 137 struct sk_buff *skb, u32 mtu, 138 bool confirm_neigh); 139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 140 struct sk_buff *skb); 141 static void ipv4_dst_destroy(struct dst_entry *dst); 142 143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 144 { 145 WARN_ON(1); 146 return NULL; 147 } 148 149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 150 struct sk_buff *skb, 151 const void *daddr); 152 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 153 154 static struct dst_ops ipv4_dst_ops = { 155 .family = AF_INET, 156 .check = ipv4_dst_check, 157 .default_advmss = ipv4_default_advmss, 158 .mtu = ipv4_mtu, 159 .cow_metrics = ipv4_cow_metrics, 160 .destroy = ipv4_dst_destroy, 161 .negative_advice = ipv4_negative_advice, 162 .link_failure = ipv4_link_failure, 163 .update_pmtu = ip_rt_update_pmtu, 164 .redirect = ip_do_redirect, 165 .local_out = __ip_local_out, 166 .neigh_lookup = ipv4_neigh_lookup, 167 .confirm_neigh = ipv4_confirm_neigh, 168 }; 169 170 #define ECN_OR_COST(class) TC_PRIO_##class 171 172 const __u8 ip_tos2prio[16] = { 173 TC_PRIO_BESTEFFORT, 174 ECN_OR_COST(BESTEFFORT), 175 TC_PRIO_BESTEFFORT, 176 ECN_OR_COST(BESTEFFORT), 177 TC_PRIO_BULK, 178 ECN_OR_COST(BULK), 179 TC_PRIO_BULK, 180 ECN_OR_COST(BULK), 181 TC_PRIO_INTERACTIVE, 182 ECN_OR_COST(INTERACTIVE), 183 TC_PRIO_INTERACTIVE, 184 ECN_OR_COST(INTERACTIVE), 185 TC_PRIO_INTERACTIVE_BULK, 186 ECN_OR_COST(INTERACTIVE_BULK), 187 TC_PRIO_INTERACTIVE_BULK, 188 ECN_OR_COST(INTERACTIVE_BULK) 189 }; 190 EXPORT_SYMBOL(ip_tos2prio); 191 192 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 193 #ifndef CONFIG_PREEMPT_RT 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 #else 196 #define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) 197 #endif 198 199 #ifdef CONFIG_PROC_FS 200 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 201 { 202 if (*pos) 203 return NULL; 204 return SEQ_START_TOKEN; 205 } 206 207 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 208 { 209 ++*pos; 210 return NULL; 211 } 212 213 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 214 { 215 } 216 217 static int rt_cache_seq_show(struct seq_file *seq, void *v) 218 { 219 if (v == SEQ_START_TOKEN) 220 seq_printf(seq, "%-127s\n", 221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 223 "HHUptod\tSpecDst"); 224 return 0; 225 } 226 227 static const struct seq_operations rt_cache_seq_ops = { 228 .start = rt_cache_seq_start, 229 .next = rt_cache_seq_next, 230 .stop = rt_cache_seq_stop, 231 .show = rt_cache_seq_show, 232 }; 233 234 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 235 { 236 int cpu; 237 238 if (*pos == 0) 239 return SEQ_START_TOKEN; 240 241 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 242 if (!cpu_possible(cpu)) 243 continue; 244 *pos = cpu+1; 245 return &per_cpu(rt_cache_stat, cpu); 246 } 247 return NULL; 248 } 249 250 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 251 { 252 int cpu; 253 254 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 255 if (!cpu_possible(cpu)) 256 continue; 257 *pos = cpu+1; 258 return &per_cpu(rt_cache_stat, cpu); 259 } 260 (*pos)++; 261 return NULL; 262 263 } 264 265 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 266 { 267 268 } 269 270 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 271 { 272 struct rt_cache_stat *st = v; 273 274 if (v == SEQ_START_TOKEN) { 275 seq_puts(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 276 return 0; 277 } 278 279 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 280 "%08x %08x %08x %08x %08x %08x " 281 "%08x %08x %08x %08x\n", 282 dst_entries_get_slow(&ipv4_dst_ops), 283 0, /* st->in_hit */ 284 st->in_slow_tot, 285 st->in_slow_mc, 286 st->in_no_route, 287 st->in_brd, 288 st->in_martian_dst, 289 st->in_martian_src, 290 291 0, /* st->out_hit */ 292 st->out_slow_tot, 293 st->out_slow_mc, 294 295 0, /* st->gc_total */ 296 0, /* st->gc_ignored */ 297 0, /* st->gc_goal_miss */ 298 0, /* st->gc_dst_overflow */ 299 0, /* st->in_hlist_search */ 300 0 /* st->out_hlist_search */ 301 ); 302 return 0; 303 } 304 305 static const struct seq_operations rt_cpu_seq_ops = { 306 .start = rt_cpu_seq_start, 307 .next = rt_cpu_seq_next, 308 .stop = rt_cpu_seq_stop, 309 .show = rt_cpu_seq_show, 310 }; 311 312 #ifdef CONFIG_IP_ROUTE_CLASSID 313 static int rt_acct_proc_show(struct seq_file *m, void *v) 314 { 315 struct ip_rt_acct *dst, *src; 316 unsigned int i, j; 317 318 dst = kzalloc_objs(struct ip_rt_acct, 256); 319 if (!dst) 320 return -ENOMEM; 321 322 for_each_possible_cpu(i) { 323 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 324 for (j = 0; j < 256; j++) { 325 dst[j].o_bytes += src[j].o_bytes; 326 dst[j].o_packets += src[j].o_packets; 327 dst[j].i_bytes += src[j].i_bytes; 328 dst[j].i_packets += src[j].i_packets; 329 } 330 } 331 332 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 333 kfree(dst); 334 return 0; 335 } 336 #endif 337 338 static int __net_init ip_rt_do_proc_init(struct net *net) 339 { 340 struct proc_dir_entry *pde; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 343 &rt_cache_seq_ops); 344 if (!pde) 345 goto err1; 346 347 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 348 &rt_cpu_seq_ops); 349 if (!pde) 350 goto err2; 351 352 #ifdef CONFIG_IP_ROUTE_CLASSID 353 pde = proc_create_single("rt_acct", 0, net->proc_net, 354 rt_acct_proc_show); 355 if (!pde) 356 goto err3; 357 #endif 358 return 0; 359 360 #ifdef CONFIG_IP_ROUTE_CLASSID 361 err3: 362 remove_proc_entry("rt_cache", net->proc_net_stat); 363 #endif 364 err2: 365 remove_proc_entry("rt_cache", net->proc_net); 366 err1: 367 return -ENOMEM; 368 } 369 370 static void __net_exit ip_rt_do_proc_exit(struct net *net) 371 { 372 remove_proc_entry("rt_cache", net->proc_net_stat); 373 remove_proc_entry("rt_cache", net->proc_net); 374 #ifdef CONFIG_IP_ROUTE_CLASSID 375 remove_proc_entry("rt_acct", net->proc_net); 376 #endif 377 } 378 379 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 380 .init = ip_rt_do_proc_init, 381 .exit = ip_rt_do_proc_exit, 382 }; 383 384 static int __init ip_rt_proc_init(void) 385 { 386 return register_pernet_subsys(&ip_rt_proc_ops); 387 } 388 389 #else 390 static inline int ip_rt_proc_init(void) 391 { 392 return 0; 393 } 394 #endif /* CONFIG_PROC_FS */ 395 396 static inline bool rt_is_expired(const struct rtable *rth) 397 { 398 bool res; 399 400 rcu_read_lock(); 401 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev)); 402 rcu_read_unlock(); 403 404 return res; 405 } 406 407 void rt_cache_flush(struct net *net) 408 { 409 rt_genid_bump_ipv4(net); 410 } 411 412 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 413 struct sk_buff *skb, 414 const void *daddr) 415 { 416 const struct rtable *rt = container_of(dst, struct rtable, dst); 417 struct net_device *dev; 418 struct neighbour *n; 419 420 rcu_read_lock(); 421 dev = dst_dev_rcu(dst); 422 if (likely(rt->rt_gw_family == AF_INET)) { 423 n = ip_neigh_gw4(dev, rt->rt_gw4); 424 } else if (rt->rt_gw_family == AF_INET6) { 425 n = ip_neigh_gw6(dev, &rt->rt_gw6); 426 } else { 427 __be32 pkey; 428 429 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 430 n = ip_neigh_gw4(dev, pkey); 431 } 432 433 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 434 n = NULL; 435 436 rcu_read_unlock(); 437 438 return n; 439 } 440 441 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 442 { 443 const struct rtable *rt = container_of(dst, struct rtable, dst); 444 struct net_device *dev = dst_dev(dst); 445 const __be32 *pkey = daddr; 446 447 if (rt->rt_gw_family == AF_INET) { 448 pkey = (const __be32 *)&rt->rt_gw4; 449 } else if (IS_ENABLED(CONFIG_IPV6) && rt->rt_gw_family == AF_INET6) { 450 return __ipv6_confirm_neigh(dev, &rt->rt_gw6); 451 } else if (!daddr || 452 (rt->rt_flags & 453 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 454 return; 455 } 456 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 457 } 458 459 /* Hash tables of size 2048..262144 depending on RAM size. 460 * Each bucket uses 8 bytes. 461 */ 462 static u32 ip_idents_mask __read_mostly; 463 static atomic_t *ip_idents __read_mostly; 464 static u32 *ip_tstamps __read_mostly; 465 466 /* In order to protect privacy, we add a perturbation to identifiers 467 * if one generator is seldom used. This makes hard for an attacker 468 * to infer how many packets were sent between two points in time. 469 */ 470 static u32 ip_idents_reserve(u32 hash, int segs) 471 { 472 u32 bucket, old, now = (u32)jiffies; 473 atomic_t *p_id; 474 u32 *p_tstamp; 475 u32 delta = 0; 476 477 bucket = hash & ip_idents_mask; 478 p_tstamp = ip_tstamps + bucket; 479 p_id = ip_idents + bucket; 480 old = READ_ONCE(*p_tstamp); 481 482 if (old != now && cmpxchg(p_tstamp, old, now) == old) 483 delta = get_random_u32_below(now - old); 484 485 /* If UBSAN reports an error there, please make sure your compiler 486 * supports -fno-strict-overflow before reporting it that was a bug 487 * in UBSAN, and it has been fixed in GCC-8. 488 */ 489 return atomic_add_return(segs + delta, p_id) - segs; 490 } 491 492 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 493 { 494 u32 hash, id; 495 496 /* Note the following code is not safe, but this is okay. */ 497 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 498 get_random_bytes(&net->ipv4.ip_id_key, 499 sizeof(net->ipv4.ip_id_key)); 500 501 hash = siphash_3u32((__force u32)iph->daddr, 502 (__force u32)iph->saddr, 503 iph->protocol, 504 &net->ipv4.ip_id_key); 505 id = ip_idents_reserve(hash, segs); 506 iph->id = htons(id); 507 } 508 EXPORT_SYMBOL(__ip_select_ident); 509 510 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 511 const struct sock *sk, const struct iphdr *iph, 512 int oif, __u8 tos, u8 prot, u32 mark, 513 int flow_flags) 514 { 515 __u8 scope = RT_SCOPE_UNIVERSE; 516 517 if (sk) { 518 oif = sk->sk_bound_dev_if; 519 mark = READ_ONCE(sk->sk_mark); 520 tos = ip_sock_rt_tos(sk); 521 scope = ip_sock_rt_scope(sk); 522 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 523 sk->sk_protocol; 524 } 525 526 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope, 527 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 528 sock_net_uid(net, sk)); 529 } 530 531 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 532 const struct sock *sk) 533 { 534 const struct net *net = dev_net(skb->dev); 535 const struct iphdr *iph = ip_hdr(skb); 536 int oif = skb->dev->ifindex; 537 u8 prot = iph->protocol; 538 u32 mark = skb->mark; 539 __u8 tos = iph->tos; 540 541 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 542 } 543 544 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 545 { 546 const struct inet_sock *inet = inet_sk(sk); 547 const struct ip_options_rcu *inet_opt; 548 __be32 daddr = inet->inet_daddr; 549 550 rcu_read_lock(); 551 inet_opt = rcu_dereference(inet->inet_opt); 552 if (inet_opt && inet_opt->opt.srr) 553 daddr = inet_opt->opt.faddr; 554 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 555 ip_sock_rt_tos(sk), 556 ip_sock_rt_scope(sk), 557 inet_test_bit(HDRINCL, sk) ? 558 IPPROTO_RAW : sk->sk_protocol, 559 inet_sk_flowi_flags(sk), 560 daddr, inet->inet_saddr, 0, 0, 561 sk_uid(sk)); 562 rcu_read_unlock(); 563 } 564 565 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 566 const struct sk_buff *skb) 567 { 568 if (skb) 569 build_skb_flow_key(fl4, skb, sk); 570 else 571 build_sk_flow_key(fl4, sk); 572 } 573 574 static DEFINE_SPINLOCK(fnhe_lock); 575 576 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 577 { 578 struct rtable *rt; 579 580 rt = rcu_dereference(fnhe->fnhe_rth_input); 581 if (rt) { 582 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 583 dst_dev_put(&rt->dst); 584 dst_release(&rt->dst); 585 } 586 rt = rcu_dereference(fnhe->fnhe_rth_output); 587 if (rt) { 588 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 589 dst_dev_put(&rt->dst); 590 dst_release(&rt->dst); 591 } 592 } 593 594 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 595 { 596 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 597 struct fib_nh_exception *fnhe, *oldest = NULL; 598 599 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 600 fnhe = rcu_dereference_protected(*fnhe_p, 601 lockdep_is_held(&fnhe_lock)); 602 if (!fnhe) 603 break; 604 if (!oldest || 605 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 606 oldest = fnhe; 607 oldest_p = fnhe_p; 608 } 609 } 610 611 /* Clear oldest->fnhe_daddr to prevent this fnhe from being 612 * rebound with new dsts in rt_bind_exception(). 613 */ 614 oldest->fnhe_daddr = 0; 615 fnhe_flush_routes(oldest); 616 *oldest_p = oldest->fnhe_next; 617 kfree_rcu(oldest, rcu); 618 } 619 620 static u32 fnhe_hashfun(__be32 daddr) 621 { 622 static siphash_aligned_key_t fnhe_hash_key; 623 u64 hval; 624 625 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 626 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 627 return hash_64(hval, FNHE_HASH_SHIFT); 628 } 629 630 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 631 { 632 rt->rt_pmtu = fnhe->fnhe_pmtu; 633 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 634 rt->dst.expires = fnhe->fnhe_expires; 635 636 if (fnhe->fnhe_gw) { 637 rt->rt_flags |= RTCF_REDIRECTED; 638 rt->rt_uses_gateway = 1; 639 rt->rt_gw_family = AF_INET; 640 rt->rt_gw4 = fnhe->fnhe_gw; 641 } 642 } 643 644 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 645 __be32 gw, u32 pmtu, bool lock, 646 unsigned long expires) 647 { 648 struct fnhe_hash_bucket *hash; 649 struct fib_nh_exception *fnhe; 650 struct rtable *rt; 651 u32 genid, hval; 652 unsigned int i; 653 int depth; 654 655 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 656 hval = fnhe_hashfun(daddr); 657 658 spin_lock_bh(&fnhe_lock); 659 660 hash = rcu_dereference(nhc->nhc_exceptions); 661 if (!hash) { 662 hash = kzalloc_objs(*hash, FNHE_HASH_SIZE, GFP_ATOMIC); 663 if (!hash) 664 goto out_unlock; 665 rcu_assign_pointer(nhc->nhc_exceptions, hash); 666 } 667 668 hash += hval; 669 670 depth = 0; 671 for (fnhe = rcu_dereference(hash->chain); fnhe; 672 fnhe = rcu_dereference(fnhe->fnhe_next)) { 673 if (fnhe->fnhe_daddr == daddr) 674 break; 675 depth++; 676 } 677 678 if (fnhe) { 679 if (fnhe->fnhe_genid != genid) 680 fnhe->fnhe_genid = genid; 681 if (gw) 682 fnhe->fnhe_gw = gw; 683 if (pmtu) { 684 fnhe->fnhe_pmtu = pmtu; 685 fnhe->fnhe_mtu_locked = lock; 686 } 687 fnhe->fnhe_expires = max(1UL, expires); 688 /* Update all cached dsts too */ 689 rt = rcu_dereference(fnhe->fnhe_rth_input); 690 if (rt) 691 fill_route_from_fnhe(rt, fnhe); 692 rt = rcu_dereference(fnhe->fnhe_rth_output); 693 if (rt) 694 fill_route_from_fnhe(rt, fnhe); 695 } else { 696 /* Randomize max depth to avoid some side channels attacks. */ 697 int max_depth = FNHE_RECLAIM_DEPTH + 698 get_random_u32_below(FNHE_RECLAIM_DEPTH); 699 700 while (depth > max_depth) { 701 fnhe_remove_oldest(hash); 702 depth--; 703 } 704 705 fnhe = kzalloc_obj(*fnhe, GFP_ATOMIC); 706 if (!fnhe) 707 goto out_unlock; 708 709 fnhe->fnhe_next = hash->chain; 710 711 fnhe->fnhe_genid = genid; 712 fnhe->fnhe_daddr = daddr; 713 fnhe->fnhe_gw = gw; 714 fnhe->fnhe_pmtu = pmtu; 715 fnhe->fnhe_mtu_locked = lock; 716 fnhe->fnhe_expires = max(1UL, expires); 717 718 rcu_assign_pointer(hash->chain, fnhe); 719 720 /* Exception created; mark the cached routes for the nexthop 721 * stale, so anyone caching it rechecks if this exception 722 * applies to them. 723 */ 724 rt = rcu_dereference(nhc->nhc_rth_input); 725 if (rt) 726 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 727 728 for_each_possible_cpu(i) { 729 struct rtable __rcu **prt; 730 731 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 732 rt = rcu_dereference(*prt); 733 if (rt) 734 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 735 } 736 } 737 738 fnhe->fnhe_stamp = jiffies; 739 740 out_unlock: 741 spin_unlock_bh(&fnhe_lock); 742 } 743 744 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 745 bool kill_route) 746 { 747 __be32 new_gw = icmp_hdr(skb)->un.gateway; 748 __be32 old_gw = ip_hdr(skb)->saddr; 749 struct net_device *dev = skb->dev; 750 struct in_device *in_dev; 751 struct fib_result res; 752 struct neighbour *n; 753 struct net *net; 754 755 switch (icmp_hdr(skb)->code & 7) { 756 case ICMP_REDIR_NET: 757 case ICMP_REDIR_NETTOS: 758 case ICMP_REDIR_HOST: 759 case ICMP_REDIR_HOSTTOS: 760 break; 761 762 default: 763 return; 764 } 765 766 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 767 return; 768 769 in_dev = __in_dev_get_rcu(dev); 770 if (!in_dev) 771 return; 772 773 net = dev_net(dev); 774 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 775 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 776 ipv4_is_zeronet(new_gw)) 777 goto reject_redirect; 778 779 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 780 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 781 goto reject_redirect; 782 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 783 goto reject_redirect; 784 } else { 785 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 786 goto reject_redirect; 787 } 788 789 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 790 if (!n) 791 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 792 if (!IS_ERR(n)) { 793 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 794 neigh_event_send(n, NULL); 795 } else { 796 if (fib_lookup(net, fl4, &res, 0) == 0) { 797 struct fib_nh_common *nhc; 798 799 fib_select_path(net, &res, fl4, skb); 800 nhc = FIB_RES_NHC(res); 801 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 802 0, false, 803 jiffies + ip_rt_gc_timeout); 804 } 805 if (kill_route) 806 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 807 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 808 } 809 neigh_release(n); 810 } 811 return; 812 813 reject_redirect: 814 #ifdef CONFIG_IP_ROUTE_VERBOSE 815 if (IN_DEV_LOG_MARTIANS(in_dev)) { 816 const struct iphdr *iph = (const struct iphdr *) skb->data; 817 __be32 daddr = iph->daddr; 818 __be32 saddr = iph->saddr; 819 820 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 821 " Advised path = %pI4 -> %pI4\n", 822 &old_gw, dev->name, &new_gw, 823 &saddr, &daddr); 824 } 825 #endif 826 ; 827 } 828 829 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 830 { 831 struct rtable *rt; 832 struct flowi4 fl4; 833 const struct iphdr *iph = (const struct iphdr *) skb->data; 834 struct net *net = dev_net(skb->dev); 835 int oif = skb->dev->ifindex; 836 u8 prot = iph->protocol; 837 u32 mark = skb->mark; 838 __u8 tos = iph->tos; 839 840 rt = dst_rtable(dst); 841 842 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 843 __ip_do_redirect(rt, skb, &fl4, true); 844 } 845 846 static void ipv4_negative_advice(struct sock *sk, 847 struct dst_entry *dst) 848 { 849 struct rtable *rt = dst_rtable(dst); 850 851 if ((READ_ONCE(dst->obsolete) > 0) || 852 (rt->rt_flags & RTCF_REDIRECTED) || 853 READ_ONCE(rt->dst.expires)) 854 sk_dst_reset(sk); 855 } 856 857 /* 858 * Algorithm: 859 * 1. The first ip_rt_redirect_number redirects are sent 860 * with exponential backoff, then we stop sending them at all, 861 * assuming that the host ignores our redirects. 862 * 2. If we did not see packets requiring redirects 863 * during ip_rt_redirect_silence, we assume that the host 864 * forgot redirected route and start to send redirects again. 865 * 866 * This algorithm is much cheaper and more intelligent than dumb load limiting 867 * in icmp.c. 868 * 869 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 870 * and "frag. need" (breaks PMTU discovery) in icmp.c. 871 */ 872 873 void ip_rt_send_redirect(struct sk_buff *skb) 874 { 875 struct rtable *rt = skb_rtable(skb); 876 struct in_device *in_dev; 877 struct inet_peer *peer; 878 struct net *net; 879 int log_martians; 880 int vif; 881 882 rcu_read_lock(); 883 in_dev = __in_dev_get_rcu(rt->dst.dev); 884 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 885 rcu_read_unlock(); 886 return; 887 } 888 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 889 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 890 891 net = dev_net(rt->dst.dev); 892 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 893 if (!peer) { 894 rcu_read_unlock(); 895 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 896 rt_nexthop(rt, ip_hdr(skb)->daddr)); 897 return; 898 } 899 900 /* No redirected packets during ip_rt_redirect_silence; 901 * reset the algorithm. 902 */ 903 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 904 peer->rate_tokens = 0; 905 peer->n_redirects = 0; 906 } 907 908 /* Too many ignored redirects; do not send anything 909 * set dst.rate_last to the last seen redirected packet. 910 */ 911 if (peer->n_redirects >= ip_rt_redirect_number) { 912 peer->rate_last = jiffies; 913 goto out_unlock; 914 } 915 916 /* Check for load limit; set rate_last to the latest sent 917 * redirect. 918 */ 919 if (peer->n_redirects == 0 || 920 time_after(jiffies, 921 (peer->rate_last + 922 (ip_rt_redirect_load << peer->n_redirects)))) { 923 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 924 925 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 926 peer->rate_last = jiffies; 927 ++peer->n_redirects; 928 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 929 peer->n_redirects == ip_rt_redirect_number) 930 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 931 &ip_hdr(skb)->saddr, inet_iif(skb), 932 &ip_hdr(skb)->daddr, &gw); 933 } 934 out_unlock: 935 rcu_read_unlock(); 936 } 937 938 static int ip_error(struct sk_buff *skb) 939 { 940 struct rtable *rt = skb_rtable(skb); 941 struct net_device *dev = skb->dev; 942 struct in_device *in_dev; 943 struct inet_peer *peer; 944 unsigned long now; 945 struct net *net; 946 SKB_DR(reason); 947 bool send; 948 int code; 949 950 if (netif_is_l3_master(skb->dev)) { 951 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 952 if (!dev) 953 goto out; 954 } 955 956 in_dev = __in_dev_get_rcu(dev); 957 958 /* IP on this device is disabled. */ 959 if (!in_dev) 960 goto out; 961 962 net = dev_net(rt->dst.dev); 963 if (!IN_DEV_FORWARD(in_dev)) { 964 switch (rt->dst.error) { 965 case EHOSTUNREACH: 966 SKB_DR_SET(reason, IP_INADDRERRORS); 967 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 968 break; 969 970 case ENETUNREACH: 971 SKB_DR_SET(reason, IP_INNOROUTES); 972 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 973 break; 974 } 975 goto out; 976 } 977 978 switch (rt->dst.error) { 979 case EINVAL: 980 default: 981 goto out; 982 case EHOSTUNREACH: 983 code = ICMP_HOST_UNREACH; 984 break; 985 case ENETUNREACH: 986 code = ICMP_NET_UNREACH; 987 SKB_DR_SET(reason, IP_INNOROUTES); 988 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 989 break; 990 case EACCES: 991 code = ICMP_PKT_FILTERED; 992 break; 993 } 994 995 rcu_read_lock(); 996 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 997 l3mdev_master_ifindex_rcu(skb->dev)); 998 send = true; 999 if (peer) { 1000 now = jiffies; 1001 peer->rate_tokens += now - peer->rate_last; 1002 if (peer->rate_tokens > ip_rt_error_burst) 1003 peer->rate_tokens = ip_rt_error_burst; 1004 peer->rate_last = now; 1005 if (peer->rate_tokens >= ip_rt_error_cost) 1006 peer->rate_tokens -= ip_rt_error_cost; 1007 else 1008 send = false; 1009 } 1010 rcu_read_unlock(); 1011 1012 if (send) 1013 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1014 1015 out: kfree_skb_reason(skb, reason); 1016 return 0; 1017 } 1018 1019 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1020 { 1021 struct dst_entry *dst = &rt->dst; 1022 struct fib_result res; 1023 bool lock = false; 1024 struct net *net; 1025 u32 old_mtu; 1026 1027 if (ip_mtu_locked(dst)) 1028 return; 1029 1030 old_mtu = ipv4_mtu(dst); 1031 if (old_mtu < mtu) 1032 return; 1033 1034 rcu_read_lock(); 1035 net = dst_dev_net_rcu(dst); 1036 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1037 lock = true; 1038 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1039 } 1040 1041 if (rt->rt_pmtu == mtu && !lock && 1042 time_before(jiffies, READ_ONCE(dst->expires) - 1043 net->ipv4.ip_rt_mtu_expires / 2)) 1044 goto out; 1045 1046 if (fib_lookup(net, fl4, &res, 0) == 0) { 1047 struct fib_nh_common *nhc; 1048 1049 fib_select_path(net, &res, fl4, NULL); 1050 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1051 if (fib_info_num_path(res.fi) > 1) { 1052 int nhsel; 1053 1054 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1055 nhc = fib_info_nhc(res.fi, nhsel); 1056 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1057 jiffies + net->ipv4.ip_rt_mtu_expires); 1058 } 1059 goto out; 1060 } 1061 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1062 nhc = FIB_RES_NHC(res); 1063 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1064 jiffies + net->ipv4.ip_rt_mtu_expires); 1065 } 1066 out: 1067 rcu_read_unlock(); 1068 } 1069 1070 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1071 struct sk_buff *skb, u32 mtu, 1072 bool confirm_neigh) 1073 { 1074 struct rtable *rt = dst_rtable(dst); 1075 struct flowi4 fl4; 1076 1077 ip_rt_build_flow_key(&fl4, sk, skb); 1078 1079 /* Don't make lookup fail for bridged encapsulations */ 1080 if (skb && netif_is_any_bridge_port(skb->dev)) 1081 fl4.flowi4_oif = 0; 1082 1083 __ip_rt_update_pmtu(rt, &fl4, mtu); 1084 } 1085 1086 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1087 int oif, u8 protocol) 1088 { 1089 const struct iphdr *iph = (const struct iphdr *)skb->data; 1090 struct flowi4 fl4; 1091 struct rtable *rt; 1092 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1093 1094 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1095 0); 1096 rt = __ip_route_output_key(net, &fl4); 1097 if (!IS_ERR(rt)) { 1098 __ip_rt_update_pmtu(rt, &fl4, mtu); 1099 ip_rt_put(rt); 1100 } 1101 } 1102 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1103 1104 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1105 { 1106 const struct iphdr *iph = (const struct iphdr *)skb->data; 1107 struct flowi4 fl4; 1108 struct rtable *rt; 1109 1110 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1111 1112 if (!fl4.flowi4_mark) 1113 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1114 1115 rt = __ip_route_output_key(sock_net(sk), &fl4); 1116 if (!IS_ERR(rt)) { 1117 __ip_rt_update_pmtu(rt, &fl4, mtu); 1118 ip_rt_put(rt); 1119 } 1120 } 1121 1122 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1123 { 1124 const struct iphdr *iph = (const struct iphdr *)skb->data; 1125 struct flowi4 fl4; 1126 struct rtable *rt; 1127 struct dst_entry *odst = NULL; 1128 bool new = false; 1129 struct net *net = sock_net(sk); 1130 1131 bh_lock_sock(sk); 1132 1133 if (!ip_sk_accept_pmtu(sk)) 1134 goto out; 1135 1136 odst = sk_dst_get(sk); 1137 1138 if (sock_owned_by_user(sk) || !odst) { 1139 __ipv4_sk_update_pmtu(skb, sk, mtu); 1140 goto out; 1141 } 1142 1143 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1144 1145 rt = dst_rtable(odst); 1146 if (READ_ONCE(odst->obsolete) && !odst->ops->check(odst, 0)) { 1147 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1148 if (IS_ERR(rt)) 1149 goto out; 1150 1151 new = true; 1152 } 1153 1154 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1155 1156 if (!dst_check(&rt->dst, 0)) { 1157 if (new) 1158 dst_release(&rt->dst); 1159 1160 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1161 if (IS_ERR(rt)) 1162 goto out; 1163 1164 new = true; 1165 } 1166 1167 if (new) 1168 sk_dst_set(sk, &rt->dst); 1169 1170 out: 1171 bh_unlock_sock(sk); 1172 dst_release(odst); 1173 } 1174 1175 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1176 int oif, u8 protocol) 1177 { 1178 const struct iphdr *iph = (const struct iphdr *)skb->data; 1179 struct flowi4 fl4; 1180 struct rtable *rt; 1181 1182 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1183 rt = __ip_route_output_key(net, &fl4); 1184 if (!IS_ERR(rt)) { 1185 __ip_do_redirect(rt, skb, &fl4, false); 1186 ip_rt_put(rt); 1187 } 1188 } 1189 EXPORT_SYMBOL_GPL(ipv4_redirect); 1190 1191 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1192 { 1193 const struct iphdr *iph = (const struct iphdr *)skb->data; 1194 struct flowi4 fl4; 1195 struct rtable *rt; 1196 struct net *net = sock_net(sk); 1197 1198 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1199 rt = __ip_route_output_key(net, &fl4); 1200 if (!IS_ERR(rt)) { 1201 __ip_do_redirect(rt, skb, &fl4, false); 1202 ip_rt_put(rt); 1203 } 1204 } 1205 1206 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1207 u32 cookie) 1208 { 1209 struct rtable *rt = dst_rtable(dst); 1210 1211 /* All IPV4 dsts are created with ->obsolete set to the value 1212 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1213 * into this function always. 1214 * 1215 * When a PMTU/redirect information update invalidates a route, 1216 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1217 * DST_OBSOLETE_DEAD. 1218 */ 1219 if (READ_ONCE(dst->obsolete) != DST_OBSOLETE_FORCE_CHK || 1220 rt_is_expired(rt)) 1221 return NULL; 1222 return dst; 1223 } 1224 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1225 1226 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1227 { 1228 struct inet_skb_parm parm; 1229 struct net_device *dev; 1230 int res; 1231 1232 /* Recompile ip options since IPCB may not be valid anymore. 1233 * Also check we have a reasonable ipv4 header. 1234 */ 1235 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1236 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1237 return; 1238 1239 memset(&parm, 0, sizeof(parm)); 1240 if (ip_hdr(skb)->ihl > 5) { 1241 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1242 return; 1243 parm.opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1244 1245 rcu_read_lock(); 1246 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1247 res = __ip_options_compile(dev_net(dev), &parm.opt, skb, NULL); 1248 rcu_read_unlock(); 1249 1250 if (res) 1251 return; 1252 } 1253 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &parm); 1254 } 1255 1256 static void ipv4_link_failure(struct sk_buff *skb) 1257 { 1258 struct rtable *rt; 1259 1260 ipv4_send_dest_unreach(skb); 1261 1262 rt = skb_rtable(skb); 1263 if (rt) 1264 dst_set_expires(&rt->dst, 0); 1265 } 1266 1267 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1268 { 1269 pr_debug("%s: %pI4 -> %pI4, %s\n", 1270 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1271 skb->dev ? skb->dev->name : "?"); 1272 kfree_skb(skb); 1273 WARN_ON_ONCE(1); 1274 return 0; 1275 } 1276 1277 /* 1278 * We do not cache source address of outgoing interface, 1279 * because it is used only by IP RR, TS and SRR options, 1280 * so that it out of fast path. 1281 * 1282 * BTW remember: "addr" is allowed to be not aligned 1283 * in IP options! 1284 */ 1285 1286 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1287 { 1288 __be32 src; 1289 1290 if (rt_is_output_route(rt)) 1291 src = ip_hdr(skb)->saddr; 1292 else { 1293 struct fib_result res; 1294 struct iphdr *iph = ip_hdr(skb); 1295 struct flowi4 fl4 = { 1296 .daddr = iph->daddr, 1297 .saddr = iph->saddr, 1298 .flowi4_dscp = ip4h_dscp(iph), 1299 .flowi4_oif = rt->dst.dev->ifindex, 1300 .flowi4_iif = skb->dev->ifindex, 1301 .flowi4_mark = skb->mark, 1302 }; 1303 1304 rcu_read_lock(); 1305 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1306 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1307 else 1308 src = inet_select_addr(rt->dst.dev, 1309 rt_nexthop(rt, iph->daddr), 1310 RT_SCOPE_UNIVERSE); 1311 rcu_read_unlock(); 1312 } 1313 memcpy(addr, &src, 4); 1314 } 1315 1316 #ifdef CONFIG_IP_ROUTE_CLASSID 1317 static void set_class_tag(struct rtable *rt, u32 tag) 1318 { 1319 if (!(rt->dst.tclassid & 0xFFFF)) 1320 rt->dst.tclassid |= tag & 0xFFFF; 1321 if (!(rt->dst.tclassid & 0xFFFF0000)) 1322 rt->dst.tclassid |= tag & 0xFFFF0000; 1323 } 1324 #endif 1325 1326 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1327 { 1328 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1329 unsigned int advmss; 1330 struct net *net; 1331 1332 rcu_read_lock(); 1333 net = dst_dev_net_rcu(dst); 1334 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1335 net->ipv4.ip_rt_min_advmss); 1336 rcu_read_unlock(); 1337 1338 return min(advmss, IPV4_MAX_PMTU - header_size); 1339 } 1340 1341 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1342 { 1343 return ip_dst_mtu_maybe_forward(dst, false); 1344 } 1345 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1346 1347 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1348 { 1349 struct fnhe_hash_bucket *hash; 1350 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1351 u32 hval = fnhe_hashfun(daddr); 1352 1353 spin_lock_bh(&fnhe_lock); 1354 1355 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1356 lockdep_is_held(&fnhe_lock)); 1357 hash += hval; 1358 1359 fnhe_p = &hash->chain; 1360 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1361 while (fnhe) { 1362 if (fnhe->fnhe_daddr == daddr) { 1363 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1364 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1365 /* set fnhe_daddr to 0 to ensure it won't bind with 1366 * new dsts in rt_bind_exception(). 1367 */ 1368 fnhe->fnhe_daddr = 0; 1369 fnhe_flush_routes(fnhe); 1370 kfree_rcu(fnhe, rcu); 1371 break; 1372 } 1373 fnhe_p = &fnhe->fnhe_next; 1374 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1375 lockdep_is_held(&fnhe_lock)); 1376 } 1377 1378 spin_unlock_bh(&fnhe_lock); 1379 } 1380 1381 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1382 __be32 daddr) 1383 { 1384 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1385 struct fib_nh_exception *fnhe; 1386 u32 hval; 1387 1388 if (!hash) 1389 return NULL; 1390 1391 hval = fnhe_hashfun(daddr); 1392 1393 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1394 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1395 if (fnhe->fnhe_daddr == daddr) { 1396 if (fnhe->fnhe_expires && 1397 time_after(jiffies, fnhe->fnhe_expires)) { 1398 ip_del_fnhe(nhc, daddr); 1399 break; 1400 } 1401 return fnhe; 1402 } 1403 } 1404 return NULL; 1405 } 1406 1407 /* MTU selection: 1408 * 1. mtu on route is locked - use it 1409 * 2. mtu from nexthop exception 1410 * 3. mtu from egress device 1411 */ 1412 1413 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1414 { 1415 struct fib_nh_common *nhc = res->nhc; 1416 struct net_device *dev = nhc->nhc_dev; 1417 struct fib_info *fi = res->fi; 1418 u32 mtu = 0; 1419 1420 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1421 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1422 mtu = fi->fib_mtu; 1423 1424 if (likely(!mtu)) { 1425 struct fib_nh_exception *fnhe; 1426 1427 fnhe = find_exception(nhc, daddr); 1428 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1429 mtu = fnhe->fnhe_pmtu; 1430 } 1431 1432 if (likely(!mtu)) 1433 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1434 1435 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1436 } 1437 1438 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1439 __be32 daddr, const bool do_cache) 1440 { 1441 bool ret = false; 1442 1443 spin_lock_bh(&fnhe_lock); 1444 1445 if (daddr == fnhe->fnhe_daddr) { 1446 struct rtable __rcu **porig; 1447 struct rtable *orig; 1448 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1449 1450 if (rt_is_input_route(rt)) 1451 porig = &fnhe->fnhe_rth_input; 1452 else 1453 porig = &fnhe->fnhe_rth_output; 1454 orig = rcu_dereference(*porig); 1455 1456 if (fnhe->fnhe_genid != genid) { 1457 fnhe->fnhe_genid = genid; 1458 fnhe->fnhe_gw = 0; 1459 fnhe->fnhe_pmtu = 0; 1460 fnhe->fnhe_expires = 0; 1461 fnhe->fnhe_mtu_locked = false; 1462 fnhe_flush_routes(fnhe); 1463 orig = NULL; 1464 } 1465 fill_route_from_fnhe(rt, fnhe); 1466 if (!rt->rt_gw4) { 1467 rt->rt_gw4 = daddr; 1468 rt->rt_gw_family = AF_INET; 1469 } 1470 1471 if (do_cache) { 1472 dst_hold(&rt->dst); 1473 rcu_assign_pointer(*porig, rt); 1474 if (orig) { 1475 dst_dev_put(&orig->dst); 1476 dst_release(&orig->dst); 1477 } 1478 ret = true; 1479 } 1480 1481 fnhe->fnhe_stamp = jiffies; 1482 } 1483 spin_unlock_bh(&fnhe_lock); 1484 1485 return ret; 1486 } 1487 1488 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1489 { 1490 struct rtable *orig, *prev, **p; 1491 bool ret = true; 1492 1493 if (rt_is_input_route(rt)) { 1494 p = (struct rtable **)&nhc->nhc_rth_input; 1495 } else { 1496 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1497 } 1498 orig = *p; 1499 1500 /* hold dst before doing cmpxchg() to avoid race condition 1501 * on this dst 1502 */ 1503 dst_hold(&rt->dst); 1504 prev = cmpxchg(p, orig, rt); 1505 if (prev == orig) { 1506 if (orig) { 1507 rt_add_uncached_list(orig); 1508 dst_release(&orig->dst); 1509 } 1510 } else { 1511 dst_release(&rt->dst); 1512 ret = false; 1513 } 1514 1515 return ret; 1516 } 1517 1518 struct uncached_list { 1519 spinlock_t lock; 1520 struct list_head head; 1521 }; 1522 1523 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1524 1525 void rt_add_uncached_list(struct rtable *rt) 1526 { 1527 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1528 1529 rt->dst.rt_uncached_list = ul; 1530 1531 spin_lock_bh(&ul->lock); 1532 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1533 spin_unlock_bh(&ul->lock); 1534 } 1535 1536 void rt_del_uncached_list(struct rtable *rt) 1537 { 1538 struct uncached_list *ul = rt->dst.rt_uncached_list; 1539 1540 if (ul) { 1541 spin_lock_bh(&ul->lock); 1542 list_del_init(&rt->dst.rt_uncached); 1543 spin_unlock_bh(&ul->lock); 1544 } 1545 } 1546 1547 static void ipv4_dst_destroy(struct dst_entry *dst) 1548 { 1549 ip_dst_metrics_put(dst); 1550 rt_del_uncached_list(dst_rtable(dst)); 1551 } 1552 1553 void rt_flush_dev(struct net_device *dev) 1554 { 1555 struct rtable *rt, *safe; 1556 int cpu; 1557 1558 for_each_possible_cpu(cpu) { 1559 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1560 1561 if (list_empty(&ul->head)) 1562 continue; 1563 1564 spin_lock_bh(&ul->lock); 1565 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1566 if (rt->dst.dev != dev) 1567 continue; 1568 rt->dst.dev = blackhole_netdev; 1569 netdev_ref_replace(dev, blackhole_netdev, 1570 &rt->dst.dev_tracker, GFP_ATOMIC); 1571 list_del_init(&rt->dst.rt_uncached); 1572 } 1573 spin_unlock_bh(&ul->lock); 1574 } 1575 } 1576 1577 static bool rt_cache_valid(const struct rtable *rt) 1578 { 1579 return rt && 1580 READ_ONCE(rt->dst.obsolete) == DST_OBSOLETE_FORCE_CHK && 1581 !rt_is_expired(rt); 1582 } 1583 1584 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1585 const struct fib_result *res, 1586 struct fib_nh_exception *fnhe, 1587 struct fib_info *fi, u16 type, u32 itag, 1588 const bool do_cache) 1589 { 1590 bool cached = false; 1591 1592 if (fi) { 1593 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1594 1595 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1596 rt->rt_uses_gateway = 1; 1597 rt->rt_gw_family = nhc->nhc_gw_family; 1598 /* only INET and INET6 are supported */ 1599 if (likely(nhc->nhc_gw_family == AF_INET)) 1600 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1601 else 1602 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1603 } 1604 1605 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1606 1607 #ifdef CONFIG_IP_ROUTE_CLASSID 1608 if (nhc->nhc_family == AF_INET) { 1609 struct fib_nh *nh; 1610 1611 nh = container_of(nhc, struct fib_nh, nh_common); 1612 rt->dst.tclassid = nh->nh_tclassid; 1613 } 1614 #endif 1615 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1616 if (unlikely(fnhe)) 1617 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1618 else if (do_cache) 1619 cached = rt_cache_route(nhc, rt); 1620 if (unlikely(!cached)) { 1621 /* Routes we intend to cache in nexthop exception or 1622 * FIB nexthop have the DST_NOCACHE bit clear. 1623 * However, if we are unsuccessful at storing this 1624 * route into the cache we really need to set it. 1625 */ 1626 if (!rt->rt_gw4) { 1627 rt->rt_gw_family = AF_INET; 1628 rt->rt_gw4 = daddr; 1629 } 1630 rt_add_uncached_list(rt); 1631 } 1632 } else 1633 rt_add_uncached_list(rt); 1634 1635 #ifdef CONFIG_IP_ROUTE_CLASSID 1636 #ifdef CONFIG_IP_MULTIPLE_TABLES 1637 set_class_tag(rt, res->tclassid); 1638 #endif 1639 set_class_tag(rt, itag); 1640 #endif 1641 } 1642 1643 struct rtable *rt_dst_alloc(struct net_device *dev, 1644 unsigned int flags, u16 type, 1645 bool noxfrm) 1646 { 1647 struct rtable *rt; 1648 1649 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1650 (noxfrm ? DST_NOXFRM : 0)); 1651 1652 if (rt) { 1653 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1654 rt->rt_flags = flags; 1655 rt->rt_type = type; 1656 rt->rt_is_input = 0; 1657 rt->rt_iif = 0; 1658 rt->rt_pmtu = 0; 1659 rt->rt_mtu_locked = 0; 1660 rt->rt_uses_gateway = 0; 1661 rt->rt_gw_family = 0; 1662 rt->rt_gw4 = 0; 1663 1664 rt->dst.output = ip_output; 1665 if (flags & RTCF_LOCAL) 1666 rt->dst.input = ip_local_deliver; 1667 } 1668 1669 return rt; 1670 } 1671 EXPORT_SYMBOL(rt_dst_alloc); 1672 1673 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1674 { 1675 struct rtable *new_rt; 1676 1677 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1678 rt->dst.flags); 1679 1680 if (new_rt) { 1681 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1682 new_rt->rt_flags = rt->rt_flags; 1683 new_rt->rt_type = rt->rt_type; 1684 new_rt->rt_is_input = rt->rt_is_input; 1685 new_rt->rt_iif = rt->rt_iif; 1686 new_rt->rt_pmtu = rt->rt_pmtu; 1687 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1688 new_rt->rt_gw_family = rt->rt_gw_family; 1689 if (rt->rt_gw_family == AF_INET) 1690 new_rt->rt_gw4 = rt->rt_gw4; 1691 else if (rt->rt_gw_family == AF_INET6) 1692 new_rt->rt_gw6 = rt->rt_gw6; 1693 1694 new_rt->dst.input = READ_ONCE(rt->dst.input); 1695 new_rt->dst.output = READ_ONCE(rt->dst.output); 1696 new_rt->dst.error = rt->dst.error; 1697 new_rt->dst.lastuse = jiffies; 1698 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1699 } 1700 return new_rt; 1701 } 1702 1703 /* called in rcu_read_lock() section */ 1704 enum skb_drop_reason 1705 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1706 dscp_t dscp, struct net_device *dev, 1707 struct in_device *in_dev, u32 *itag) 1708 { 1709 enum skb_drop_reason reason; 1710 1711 /* Primary sanity checks. */ 1712 if (!in_dev) 1713 return SKB_DROP_REASON_NOT_SPECIFIED; 1714 1715 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1716 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1717 1718 if (skb->protocol != htons(ETH_P_IP)) 1719 return SKB_DROP_REASON_INVALID_PROTO; 1720 1721 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1722 return SKB_DROP_REASON_IP_LOCALNET; 1723 1724 if (ipv4_is_zeronet(saddr)) { 1725 if (!ipv4_is_local_multicast(daddr) && 1726 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1727 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1728 } else { 1729 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1730 dev, in_dev, itag); 1731 if (reason) 1732 return reason; 1733 } 1734 return SKB_NOT_DROPPED_YET; 1735 } 1736 1737 /* called in rcu_read_lock() section */ 1738 static enum skb_drop_reason 1739 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1740 dscp_t dscp, struct net_device *dev, int our) 1741 { 1742 struct in_device *in_dev = __in_dev_get_rcu(dev); 1743 unsigned int flags = RTCF_MULTICAST; 1744 enum skb_drop_reason reason; 1745 struct rtable *rth; 1746 u32 itag = 0; 1747 1748 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1749 &itag); 1750 if (reason) 1751 return reason; 1752 1753 if (our) 1754 flags |= RTCF_LOCAL; 1755 1756 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1757 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1758 1759 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1760 false); 1761 if (!rth) 1762 return SKB_DROP_REASON_NOMEM; 1763 1764 #ifdef CONFIG_IP_ROUTE_CLASSID 1765 rth->dst.tclassid = itag; 1766 #endif 1767 rth->dst.output = ip_rt_bug; 1768 rth->rt_is_input= 1; 1769 1770 #ifdef CONFIG_IP_MROUTE 1771 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1772 rth->dst.input = ip_mr_input; 1773 #endif 1774 RT_CACHE_STAT_INC(in_slow_mc); 1775 1776 skb_dst_drop(skb); 1777 skb_dst_set(skb, &rth->dst); 1778 return SKB_NOT_DROPPED_YET; 1779 } 1780 1781 1782 static void ip_handle_martian_source(struct net_device *dev, 1783 struct in_device *in_dev, 1784 struct sk_buff *skb, 1785 __be32 daddr, 1786 __be32 saddr) 1787 { 1788 RT_CACHE_STAT_INC(in_martian_src); 1789 #ifdef CONFIG_IP_ROUTE_VERBOSE 1790 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1791 /* 1792 * RFC1812 recommendation, if source is martian, 1793 * the only hint is MAC header. 1794 */ 1795 pr_warn("martian source (src=%pI4, dst=%pI4, dev=%s)\n", 1796 &saddr, &daddr, dev->name); 1797 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1798 print_hex_dump(KERN_WARNING, "ll header: ", 1799 DUMP_PREFIX_OFFSET, 16, 1, 1800 skb_mac_header(skb), 1801 dev->hard_header_len, false); 1802 } 1803 } 1804 #endif 1805 } 1806 1807 /* called in rcu_read_lock() section */ 1808 static enum skb_drop_reason 1809 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1810 struct in_device *in_dev, __be32 daddr, 1811 __be32 saddr, dscp_t dscp) 1812 { 1813 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1814 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1815 struct net_device *dev = nhc->nhc_dev; 1816 struct fib_nh_exception *fnhe; 1817 struct rtable *rth; 1818 int err; 1819 struct in_device *out_dev; 1820 bool do_cache; 1821 u32 itag = 0; 1822 1823 /* get a working reference to the output device */ 1824 out_dev = __in_dev_get_rcu(dev); 1825 if (!out_dev) { 1826 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1827 return reason; 1828 } 1829 1830 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1831 in_dev->dev, in_dev, &itag); 1832 if (err < 0) { 1833 reason = -err; 1834 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1835 saddr); 1836 1837 goto cleanup; 1838 } 1839 1840 do_cache = res->fi && !itag; 1841 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1842 skb->protocol == htons(ETH_P_IP)) { 1843 __be32 gw; 1844 1845 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1846 if (IN_DEV_SHARED_MEDIA(out_dev) || 1847 inet_addr_onlink(out_dev, saddr, gw)) 1848 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1849 } 1850 1851 if (skb->protocol != htons(ETH_P_IP)) { 1852 /* Not IP (i.e. ARP). Do not create route, if it is 1853 * invalid for proxy arp. DNAT routes are always valid. 1854 * 1855 * Proxy arp feature have been extended to allow, ARP 1856 * replies back to the same interface, to support 1857 * Private VLAN switch technologies. See arp.c. 1858 */ 1859 if (out_dev == in_dev && 1860 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1861 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1862 goto cleanup; 1863 } 1864 } 1865 1866 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1867 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1868 1869 fnhe = find_exception(nhc, daddr); 1870 if (do_cache) { 1871 if (fnhe) 1872 rth = rcu_dereference(fnhe->fnhe_rth_input); 1873 else 1874 rth = rcu_dereference(nhc->nhc_rth_input); 1875 if (rt_cache_valid(rth)) { 1876 skb_dst_set_noref(skb, &rth->dst); 1877 goto out; 1878 } 1879 } 1880 1881 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1882 IN_DEV_ORCONF(out_dev, NOXFRM)); 1883 if (!rth) { 1884 reason = SKB_DROP_REASON_NOMEM; 1885 goto cleanup; 1886 } 1887 1888 rth->rt_is_input = 1; 1889 RT_CACHE_STAT_INC(in_slow_tot); 1890 1891 rth->dst.input = ip_forward; 1892 1893 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1894 do_cache); 1895 lwtunnel_set_redirect(&rth->dst); 1896 skb_dst_set(skb, &rth->dst); 1897 out: 1898 reason = SKB_NOT_DROPPED_YET; 1899 cleanup: 1900 return reason; 1901 } 1902 1903 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1904 /* To make ICMP packets follow the right flow, the multipath hash is 1905 * calculated from the inner IP addresses. 1906 */ 1907 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1908 struct flow_keys *hash_keys) 1909 { 1910 const struct iphdr *outer_iph = ip_hdr(skb); 1911 const struct iphdr *key_iph = outer_iph; 1912 const struct iphdr *inner_iph; 1913 const struct icmphdr *icmph; 1914 struct iphdr _inner_iph; 1915 struct icmphdr _icmph; 1916 1917 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1918 goto out; 1919 1920 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1921 goto out; 1922 1923 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1924 &_icmph); 1925 if (!icmph) 1926 goto out; 1927 1928 if (!icmp_is_err(icmph->type)) 1929 goto out; 1930 1931 inner_iph = skb_header_pointer(skb, 1932 outer_iph->ihl * 4 + sizeof(_icmph), 1933 sizeof(_inner_iph), &_inner_iph); 1934 if (!inner_iph) 1935 goto out; 1936 1937 key_iph = inner_iph; 1938 out: 1939 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1940 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1941 } 1942 1943 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1944 const struct sk_buff *skb, 1945 bool *p_has_inner) 1946 { 1947 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1948 struct flow_keys keys, hash_keys; 1949 1950 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1951 return 0; 1952 1953 memset(&hash_keys, 0, sizeof(hash_keys)); 1954 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1955 1956 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1957 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1958 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1959 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1960 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1961 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1962 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1963 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1964 hash_keys.ports.src = keys.ports.src; 1965 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1966 hash_keys.ports.dst = keys.ports.dst; 1967 1968 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1969 return fib_multipath_hash_from_keys(net, &hash_keys); 1970 } 1971 1972 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1973 const struct sk_buff *skb, 1974 bool has_inner) 1975 { 1976 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1977 struct flow_keys keys, hash_keys; 1978 1979 /* We assume the packet carries an encapsulation, but if none was 1980 * encountered during dissection of the outer flow, then there is no 1981 * point in calling the flow dissector again. 1982 */ 1983 if (!has_inner) 1984 return 0; 1985 1986 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1987 return 0; 1988 1989 memset(&hash_keys, 0, sizeof(hash_keys)); 1990 skb_flow_dissect_flow_keys(skb, &keys, 0); 1991 1992 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1993 return 0; 1994 1995 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1996 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1998 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1999 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2000 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2001 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2002 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2003 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2004 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2005 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2006 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2007 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2008 hash_keys.tags.flow_label = keys.tags.flow_label; 2009 } 2010 2011 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2012 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2013 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2014 hash_keys.ports.src = keys.ports.src; 2015 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2016 hash_keys.ports.dst = keys.ports.dst; 2017 2018 return fib_multipath_hash_from_keys(net, &hash_keys); 2019 } 2020 2021 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2022 const struct sk_buff *skb) 2023 { 2024 u32 mhash, mhash_inner; 2025 bool has_inner = true; 2026 2027 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2028 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2029 2030 return jhash_2words(mhash, mhash_inner, 0); 2031 } 2032 2033 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2034 const struct flowi4 *fl4) 2035 { 2036 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2037 struct flow_keys hash_keys; 2038 2039 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2040 return 0; 2041 2042 memset(&hash_keys, 0, sizeof(hash_keys)); 2043 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2044 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2045 hash_keys.addrs.v4addrs.src = fl4->saddr; 2046 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2047 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2048 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2049 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2050 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2051 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2052 hash_keys.ports.src = (__force __be16)get_random_u16(); 2053 else 2054 hash_keys.ports.src = fl4->fl4_sport; 2055 } 2056 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2057 hash_keys.ports.dst = fl4->fl4_dport; 2058 2059 return fib_multipath_hash_from_keys(net, &hash_keys); 2060 } 2061 2062 /* if skb is set it will be used and fl4 can be NULL */ 2063 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2064 const struct sk_buff *skb, struct flow_keys *flkeys) 2065 { 2066 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2067 struct flow_keys hash_keys; 2068 u32 mhash = 0; 2069 2070 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2071 case 0: 2072 memset(&hash_keys, 0, sizeof(hash_keys)); 2073 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2074 if (skb) { 2075 ip_multipath_l3_keys(skb, &hash_keys); 2076 } else { 2077 hash_keys.addrs.v4addrs.src = fl4->saddr; 2078 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2079 } 2080 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2081 break; 2082 case 1: 2083 /* skb is currently provided only when forwarding */ 2084 if (skb) { 2085 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2086 struct flow_keys keys; 2087 2088 /* short-circuit if we already have L4 hash present */ 2089 if (skb->l4_hash) 2090 return skb_get_hash_raw(skb) >> 1; 2091 2092 memset(&hash_keys, 0, sizeof(hash_keys)); 2093 2094 if (!flkeys) { 2095 skb_flow_dissect_flow_keys(skb, &keys, flag); 2096 flkeys = &keys; 2097 } 2098 2099 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2100 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2101 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2102 hash_keys.ports.src = flkeys->ports.src; 2103 hash_keys.ports.dst = flkeys->ports.dst; 2104 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2105 } else { 2106 memset(&hash_keys, 0, sizeof(hash_keys)); 2107 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2108 hash_keys.addrs.v4addrs.src = fl4->saddr; 2109 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2110 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2111 hash_keys.ports.src = (__force __be16)get_random_u16(); 2112 else 2113 hash_keys.ports.src = fl4->fl4_sport; 2114 hash_keys.ports.dst = fl4->fl4_dport; 2115 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2116 } 2117 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2118 break; 2119 case 2: 2120 memset(&hash_keys, 0, sizeof(hash_keys)); 2121 /* skb is currently provided only when forwarding */ 2122 if (skb) { 2123 struct flow_keys keys; 2124 2125 skb_flow_dissect_flow_keys(skb, &keys, 0); 2126 /* Inner can be v4 or v6 */ 2127 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2128 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2129 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2130 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2131 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2132 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2133 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2134 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2135 hash_keys.tags.flow_label = keys.tags.flow_label; 2136 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2137 } else { 2138 /* Same as case 0 */ 2139 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2140 ip_multipath_l3_keys(skb, &hash_keys); 2141 } 2142 } else { 2143 /* Same as case 0 */ 2144 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2145 hash_keys.addrs.v4addrs.src = fl4->saddr; 2146 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2147 } 2148 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2149 break; 2150 case 3: 2151 if (skb) 2152 mhash = fib_multipath_custom_hash_skb(net, skb); 2153 else 2154 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2155 break; 2156 } 2157 2158 if (multipath_hash) 2159 mhash = jhash_2words(mhash, multipath_hash, 0); 2160 2161 return mhash >> 1; 2162 } 2163 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2164 2165 static enum skb_drop_reason 2166 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2167 struct in_device *in_dev, __be32 daddr, 2168 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2169 { 2170 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2171 if (res->fi && fib_info_num_path(res->fi) > 1) { 2172 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2173 2174 fib_select_multipath(res, h, NULL); 2175 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2176 } 2177 #endif 2178 2179 /* create a routing cache entry */ 2180 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2181 } 2182 2183 /* Implements all the saddr-related checks as ip_route_input_slow(), 2184 * assuming daddr is valid and the destination is not a local broadcast one. 2185 * Uses the provided hint instead of performing a route lookup. 2186 */ 2187 enum skb_drop_reason 2188 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2189 dscp_t dscp, struct net_device *dev, 2190 const struct sk_buff *hint) 2191 { 2192 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2193 struct in_device *in_dev = __in_dev_get_rcu(dev); 2194 struct rtable *rt = skb_rtable(hint); 2195 struct net *net = dev_net(dev); 2196 u32 tag = 0; 2197 2198 if (!in_dev) 2199 return reason; 2200 2201 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2202 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2203 goto martian_source; 2204 } 2205 2206 if (ipv4_is_zeronet(saddr)) { 2207 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2208 goto martian_source; 2209 } 2210 2211 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2212 reason = SKB_DROP_REASON_IP_LOCALNET; 2213 goto martian_source; 2214 } 2215 2216 if (!(rt->rt_flags & RTCF_LOCAL)) 2217 goto skip_validate_source; 2218 2219 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2220 in_dev, &tag); 2221 if (reason) 2222 goto martian_source; 2223 2224 skip_validate_source: 2225 skb_dst_copy(skb, hint); 2226 return SKB_NOT_DROPPED_YET; 2227 2228 martian_source: 2229 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2230 return reason; 2231 } 2232 2233 /* get device for dst_alloc with local routes */ 2234 static struct net_device *ip_rt_get_dev(struct net *net, 2235 const struct fib_result *res) 2236 { 2237 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2238 struct net_device *dev = NULL; 2239 2240 if (nhc) 2241 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2242 2243 return dev ? : net->loopback_dev; 2244 } 2245 2246 /* 2247 * NOTE. We drop all the packets that has local source 2248 * addresses, because every properly looped back packet 2249 * must have correct destination already attached by output routine. 2250 * Changes in the enforced policies must be applied also to 2251 * ip_route_use_hint(). 2252 * 2253 * Such approach solves two big problems: 2254 * 1. Not simplex devices are handled properly. 2255 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2256 * called with rcu_read_lock() 2257 */ 2258 2259 static enum skb_drop_reason 2260 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2261 dscp_t dscp, struct net_device *dev, 2262 struct fib_result *res) 2263 { 2264 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2265 struct in_device *in_dev = __in_dev_get_rcu(dev); 2266 struct flow_keys *flkeys = NULL, _flkeys; 2267 struct net *net = dev_net(dev); 2268 struct ip_tunnel_info *tun_info; 2269 int err = -EINVAL; 2270 unsigned int flags = 0; 2271 u32 itag = 0; 2272 struct rtable *rth; 2273 struct flowi4 fl4; 2274 bool do_cache = true; 2275 2276 /* IP on this device is disabled. */ 2277 2278 if (!in_dev) 2279 goto out; 2280 2281 /* Check for the most weird martians, which can be not detected 2282 * by fib_lookup. 2283 */ 2284 2285 tun_info = skb_tunnel_info(skb); 2286 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2287 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2288 else 2289 fl4.flowi4_tun_key.tun_id = 0; 2290 skb_dst_drop(skb); 2291 2292 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2293 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2294 goto martian_source; 2295 } 2296 2297 res->fi = NULL; 2298 res->table = NULL; 2299 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2300 goto brd_input; 2301 2302 /* Accept zero addresses only to limited broadcast; 2303 * I even do not know to fix it or not. Waiting for complains :-) 2304 */ 2305 if (ipv4_is_zeronet(saddr)) { 2306 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2307 goto martian_source; 2308 } 2309 2310 if (ipv4_is_zeronet(daddr)) { 2311 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2312 goto martian_destination; 2313 } 2314 2315 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2316 * and call it once if daddr or/and saddr are loopback addresses 2317 */ 2318 if (ipv4_is_loopback(daddr)) { 2319 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2320 reason = SKB_DROP_REASON_IP_LOCALNET; 2321 goto martian_destination; 2322 } 2323 } else if (ipv4_is_loopback(saddr)) { 2324 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2325 reason = SKB_DROP_REASON_IP_LOCALNET; 2326 goto martian_source; 2327 } 2328 } 2329 2330 /* 2331 * Now we are ready to route packet. 2332 */ 2333 fl4.flowi4_l3mdev = 0; 2334 fl4.flowi4_oif = 0; 2335 fl4.flowi4_iif = dev->ifindex; 2336 fl4.flowi4_mark = skb->mark; 2337 fl4.flowi4_dscp = dscp; 2338 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2339 fl4.flowi4_flags = 0; 2340 fl4.daddr = daddr; 2341 fl4.saddr = saddr; 2342 fl4.flowi4_uid = sock_net_uid(net, NULL); 2343 fl4.flowi4_multipath_hash = 0; 2344 2345 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2346 flkeys = &_flkeys; 2347 } else { 2348 fl4.flowi4_proto = 0; 2349 fl4.fl4_sport = 0; 2350 fl4.fl4_dport = 0; 2351 } 2352 2353 err = fib_lookup(net, &fl4, res, 0); 2354 if (err != 0) { 2355 if (!IN_DEV_FORWARD(in_dev)) 2356 err = -EHOSTUNREACH; 2357 goto no_route; 2358 } 2359 2360 if (res->type == RTN_BROADCAST) { 2361 if (IN_DEV_BFORWARD(in_dev)) 2362 goto make_route; 2363 /* not do cache if bc_forwarding is enabled */ 2364 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2365 do_cache = false; 2366 goto brd_input; 2367 } 2368 2369 err = -EINVAL; 2370 if (res->type == RTN_LOCAL) { 2371 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2372 0, dev, in_dev, &itag); 2373 if (reason) 2374 goto martian_source; 2375 goto local_input; 2376 } 2377 2378 if (!IN_DEV_FORWARD(in_dev)) { 2379 err = -EHOSTUNREACH; 2380 goto no_route; 2381 } 2382 if (res->type != RTN_UNICAST) { 2383 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2384 goto martian_destination; 2385 } 2386 2387 make_route: 2388 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2389 flkeys); 2390 2391 out: 2392 return reason; 2393 2394 brd_input: 2395 if (skb->protocol != htons(ETH_P_IP)) { 2396 reason = SKB_DROP_REASON_INVALID_PROTO; 2397 goto out; 2398 } 2399 2400 if (!ipv4_is_zeronet(saddr)) { 2401 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2402 dev, in_dev, &itag); 2403 if (reason) 2404 goto martian_source; 2405 } 2406 flags |= RTCF_BROADCAST; 2407 res->type = RTN_BROADCAST; 2408 RT_CACHE_STAT_INC(in_brd); 2409 2410 local_input: 2411 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2412 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2413 2414 do_cache &= res->fi && !itag; 2415 if (do_cache) { 2416 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2417 2418 rth = rcu_dereference(nhc->nhc_rth_input); 2419 if (rt_cache_valid(rth)) { 2420 skb_dst_set_noref(skb, &rth->dst); 2421 reason = SKB_NOT_DROPPED_YET; 2422 goto out; 2423 } 2424 } 2425 2426 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2427 flags | RTCF_LOCAL, res->type, false); 2428 if (!rth) 2429 goto e_nobufs; 2430 2431 rth->dst.output= ip_rt_bug; 2432 #ifdef CONFIG_IP_ROUTE_CLASSID 2433 rth->dst.tclassid = itag; 2434 #endif 2435 rth->rt_is_input = 1; 2436 2437 RT_CACHE_STAT_INC(in_slow_tot); 2438 if (res->type == RTN_UNREACHABLE) { 2439 rth->dst.input= ip_error; 2440 rth->dst.error= -err; 2441 rth->rt_flags &= ~RTCF_LOCAL; 2442 } 2443 2444 if (do_cache) { 2445 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2446 2447 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2448 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2449 WARN_ON(rth->dst.input == lwtunnel_input); 2450 rth->dst.lwtstate->orig_input = rth->dst.input; 2451 rth->dst.input = lwtunnel_input; 2452 } 2453 2454 if (unlikely(!rt_cache_route(nhc, rth))) 2455 rt_add_uncached_list(rth); 2456 } 2457 skb_dst_set(skb, &rth->dst); 2458 reason = SKB_NOT_DROPPED_YET; 2459 goto out; 2460 2461 no_route: 2462 RT_CACHE_STAT_INC(in_no_route); 2463 res->type = RTN_UNREACHABLE; 2464 res->fi = NULL; 2465 res->table = NULL; 2466 goto local_input; 2467 2468 /* 2469 * Do not cache martian addresses: they should be logged (RFC1812) 2470 */ 2471 martian_destination: 2472 RT_CACHE_STAT_INC(in_martian_dst); 2473 #ifdef CONFIG_IP_ROUTE_VERBOSE 2474 if (IN_DEV_LOG_MARTIANS(in_dev)) 2475 net_warn_ratelimited("martian destination (src=%pI4, dst=%pI4, dev=%s)\n", 2476 &saddr, &daddr, dev->name); 2477 #endif 2478 goto out; 2479 2480 e_nobufs: 2481 reason = SKB_DROP_REASON_NOMEM; 2482 goto out; 2483 2484 martian_source: 2485 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2486 goto out; 2487 } 2488 2489 /* called with rcu_read_lock held */ 2490 static enum skb_drop_reason 2491 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2492 dscp_t dscp, struct net_device *dev, 2493 struct fib_result *res) 2494 { 2495 /* Multicast recognition logic is moved from route cache to here. 2496 * The problem was that too many Ethernet cards have broken/missing 2497 * hardware multicast filters :-( As result the host on multicasting 2498 * network acquires a lot of useless route cache entries, sort of 2499 * SDR messages from all the world. Now we try to get rid of them. 2500 * Really, provided software IP multicast filter is organized 2501 * reasonably (at least, hashed), it does not result in a slowdown 2502 * comparing with route cache reject entries. 2503 * Note, that multicast routers are not affected, because 2504 * route cache entry is created eventually. 2505 */ 2506 if (ipv4_is_multicast(daddr)) { 2507 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2508 struct in_device *in_dev = __in_dev_get_rcu(dev); 2509 int our = 0; 2510 2511 if (!in_dev) 2512 return reason; 2513 2514 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2515 ip_hdr(skb)->protocol); 2516 2517 /* check l3 master if no match yet */ 2518 if (!our && netif_is_l3_slave(dev)) { 2519 struct in_device *l3_in_dev; 2520 2521 l3_in_dev = __in_dev_get_rcu(skb->dev); 2522 if (l3_in_dev) 2523 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2524 ip_hdr(skb)->protocol); 2525 } 2526 2527 if (our 2528 #ifdef CONFIG_IP_MROUTE 2529 || 2530 (!ipv4_is_local_multicast(daddr) && 2531 IN_DEV_MFORWARD(in_dev)) 2532 #endif 2533 ) { 2534 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2535 dev, our); 2536 } 2537 return reason; 2538 } 2539 2540 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2541 } 2542 2543 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2544 __be32 saddr, dscp_t dscp, 2545 struct net_device *dev) 2546 { 2547 enum skb_drop_reason reason; 2548 struct fib_result res; 2549 2550 rcu_read_lock(); 2551 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2552 rcu_read_unlock(); 2553 2554 return reason; 2555 } 2556 EXPORT_SYMBOL(ip_route_input_noref); 2557 2558 /* called with rcu_read_lock() */ 2559 static struct rtable *__mkroute_output(const struct fib_result *res, 2560 const struct flowi4 *fl4, int orig_oif, 2561 struct net_device *dev_out, 2562 unsigned int flags) 2563 { 2564 struct fib_info *fi = res->fi; 2565 struct fib_nh_exception *fnhe; 2566 struct in_device *in_dev; 2567 u16 type = res->type; 2568 struct rtable *rth; 2569 bool do_cache; 2570 2571 in_dev = __in_dev_get_rcu(dev_out); 2572 if (!in_dev) 2573 return ERR_PTR(-EINVAL); 2574 2575 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2576 if (ipv4_is_loopback(fl4->saddr) && 2577 !(dev_out->flags & IFF_LOOPBACK) && 2578 !netif_is_l3_master(dev_out)) 2579 return ERR_PTR(-EINVAL); 2580 2581 if (ipv4_is_lbcast(fl4->daddr)) { 2582 type = RTN_BROADCAST; 2583 2584 /* reset fi to prevent gateway resolution */ 2585 fi = NULL; 2586 } else if (ipv4_is_multicast(fl4->daddr)) { 2587 type = RTN_MULTICAST; 2588 } else if (ipv4_is_zeronet(fl4->daddr)) { 2589 return ERR_PTR(-EINVAL); 2590 } 2591 2592 if (dev_out->flags & IFF_LOOPBACK) 2593 flags |= RTCF_LOCAL; 2594 2595 do_cache = true; 2596 if (type == RTN_BROADCAST) { 2597 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2598 } else if (type == RTN_MULTICAST) { 2599 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2600 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2601 fl4->flowi4_proto)) 2602 flags &= ~RTCF_LOCAL; 2603 else 2604 do_cache = false; 2605 /* If multicast route do not exist use 2606 * default one, but do not gateway in this case. 2607 * Yes, it is hack. 2608 */ 2609 if (fi && res->prefixlen < 4) 2610 fi = NULL; 2611 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2612 (orig_oif != dev_out->ifindex)) { 2613 /* For local routes that require a particular output interface 2614 * we do not want to cache the result. Caching the result 2615 * causes incorrect behaviour when there are multiple source 2616 * addresses on the interface, the end result being that if the 2617 * intended recipient is waiting on that interface for the 2618 * packet he won't receive it because it will be delivered on 2619 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2620 * be set to the loopback interface as well. 2621 */ 2622 do_cache = false; 2623 } 2624 2625 fnhe = NULL; 2626 do_cache &= fi != NULL; 2627 if (fi) { 2628 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2629 struct rtable __rcu **prth; 2630 2631 fnhe = find_exception(nhc, fl4->daddr); 2632 if (!do_cache) 2633 goto add; 2634 if (fnhe) { 2635 prth = &fnhe->fnhe_rth_output; 2636 } else { 2637 if (unlikely(fl4->flowi4_flags & 2638 FLOWI_FLAG_KNOWN_NH && 2639 !(nhc->nhc_gw_family && 2640 nhc->nhc_scope == RT_SCOPE_LINK))) { 2641 do_cache = false; 2642 goto add; 2643 } 2644 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2645 } 2646 rth = rcu_dereference(*prth); 2647 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2648 return rth; 2649 } 2650 2651 add: 2652 rth = rt_dst_alloc(dev_out, flags, type, 2653 IN_DEV_ORCONF(in_dev, NOXFRM)); 2654 if (!rth) 2655 return ERR_PTR(-ENOBUFS); 2656 2657 rth->rt_iif = orig_oif; 2658 2659 RT_CACHE_STAT_INC(out_slow_tot); 2660 2661 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2662 if (flags & RTCF_LOCAL && 2663 !(dev_out->flags & IFF_LOOPBACK)) { 2664 rth->dst.output = ip_mc_output; 2665 RT_CACHE_STAT_INC(out_slow_mc); 2666 } 2667 #ifdef CONFIG_IP_MROUTE 2668 if (type == RTN_MULTICAST) { 2669 if (IN_DEV_MFORWARD(in_dev) && 2670 !ipv4_is_local_multicast(fl4->daddr)) { 2671 rth->dst.input = ip_mr_input; 2672 rth->dst.output = ip_mr_output; 2673 } 2674 } 2675 #endif 2676 } 2677 2678 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2679 lwtunnel_set_redirect(&rth->dst); 2680 2681 return rth; 2682 } 2683 2684 /* 2685 * Major route resolver routine. 2686 */ 2687 2688 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2689 const struct sk_buff *skb) 2690 { 2691 struct fib_result res = { 2692 .type = RTN_UNSPEC, 2693 .fi = NULL, 2694 .table = NULL, 2695 .tclassid = 0, 2696 }; 2697 struct rtable *rth; 2698 2699 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2700 2701 rcu_read_lock(); 2702 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2703 rcu_read_unlock(); 2704 2705 return rth; 2706 } 2707 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2708 2709 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2710 struct fib_result *res, 2711 const struct sk_buff *skb) 2712 { 2713 struct net_device *dev_out = NULL; 2714 int orig_oif = fl4->flowi4_oif; 2715 unsigned int flags = 0; 2716 struct rtable *rth; 2717 int err; 2718 2719 if (fl4->saddr) { 2720 if (ipv4_is_multicast(fl4->saddr) || 2721 ipv4_is_lbcast(fl4->saddr)) { 2722 rth = ERR_PTR(-EINVAL); 2723 goto out; 2724 } 2725 2726 rth = ERR_PTR(-ENETUNREACH); 2727 2728 /* I removed check for oif == dev_out->oif here. 2729 * It was wrong for two reasons: 2730 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2731 * is assigned to multiple interfaces. 2732 * 2. Moreover, we are allowed to send packets with saddr 2733 * of another iface. --ANK 2734 */ 2735 2736 if (fl4->flowi4_oif == 0 && 2737 (ipv4_is_multicast(fl4->daddr) || 2738 ipv4_is_lbcast(fl4->daddr))) { 2739 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2740 dev_out = __ip_dev_find(net, fl4->saddr, false); 2741 if (!dev_out) 2742 goto out; 2743 2744 /* Special hack: user can direct multicasts 2745 * and limited broadcast via necessary interface 2746 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2747 * This hack is not just for fun, it allows 2748 * vic,vat and friends to work. 2749 * They bind socket to loopback, set ttl to zero 2750 * and expect that it will work. 2751 * From the viewpoint of routing cache they are broken, 2752 * because we are not allowed to build multicast path 2753 * with loopback source addr (look, routing cache 2754 * cannot know, that ttl is zero, so that packet 2755 * will not leave this host and route is valid). 2756 * Luckily, this hack is good workaround. 2757 */ 2758 2759 fl4->flowi4_oif = dev_out->ifindex; 2760 goto make_route; 2761 } 2762 2763 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2764 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2765 if (!__ip_dev_find(net, fl4->saddr, false)) 2766 goto out; 2767 } 2768 } 2769 2770 2771 if (fl4->flowi4_oif) { 2772 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2773 rth = ERR_PTR(-ENODEV); 2774 if (!dev_out) 2775 goto out; 2776 2777 /* RACE: Check return value of inet_select_addr instead. */ 2778 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2779 rth = ERR_PTR(-ENETUNREACH); 2780 goto out; 2781 } 2782 if (ipv4_is_local_multicast(fl4->daddr) || 2783 ipv4_is_lbcast(fl4->daddr) || 2784 fl4->flowi4_proto == IPPROTO_IGMP) { 2785 if (!fl4->saddr) 2786 fl4->saddr = inet_select_addr(dev_out, 0, 2787 RT_SCOPE_LINK); 2788 goto make_route; 2789 } 2790 if (!fl4->saddr) { 2791 if (ipv4_is_multicast(fl4->daddr)) 2792 fl4->saddr = inet_select_addr(dev_out, 0, 2793 fl4->flowi4_scope); 2794 else if (!fl4->daddr) 2795 fl4->saddr = inet_select_addr(dev_out, 0, 2796 RT_SCOPE_HOST); 2797 } 2798 } 2799 2800 if (!fl4->daddr) { 2801 fl4->daddr = fl4->saddr; 2802 if (!fl4->daddr) 2803 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2804 dev_out = net->loopback_dev; 2805 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2806 res->type = RTN_LOCAL; 2807 flags |= RTCF_LOCAL; 2808 goto make_route; 2809 } 2810 2811 err = fib_lookup(net, fl4, res, 0); 2812 if (err) { 2813 res->fi = NULL; 2814 res->table = NULL; 2815 if (fl4->flowi4_oif && 2816 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2817 /* Apparently, routing tables are wrong. Assume, 2818 * that the destination is on link. 2819 * 2820 * WHY? DW. 2821 * Because we are allowed to send to iface 2822 * even if it has NO routes and NO assigned 2823 * addresses. When oif is specified, routing 2824 * tables are looked up with only one purpose: 2825 * to catch if destination is gatewayed, rather than 2826 * direct. Moreover, if MSG_DONTROUTE is set, 2827 * we send packet, ignoring both routing tables 2828 * and ifaddr state. --ANK 2829 * 2830 * 2831 * We could make it even if oif is unknown, 2832 * likely IPv6, but we do not. 2833 */ 2834 2835 if (fl4->saddr == 0) 2836 fl4->saddr = inet_select_addr(dev_out, 0, 2837 RT_SCOPE_LINK); 2838 res->type = RTN_UNICAST; 2839 goto make_route; 2840 } 2841 rth = ERR_PTR(err); 2842 goto out; 2843 } 2844 2845 if (res->type == RTN_LOCAL) { 2846 if (!fl4->saddr) { 2847 if (res->fi->fib_prefsrc) 2848 fl4->saddr = res->fi->fib_prefsrc; 2849 else 2850 fl4->saddr = fl4->daddr; 2851 } 2852 2853 /* L3 master device is the loopback for that domain */ 2854 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2855 net->loopback_dev; 2856 2857 /* make sure orig_oif points to fib result device even 2858 * though packet rx/tx happens over loopback or l3mdev 2859 */ 2860 orig_oif = FIB_RES_OIF(*res); 2861 2862 fl4->flowi4_oif = dev_out->ifindex; 2863 flags |= RTCF_LOCAL; 2864 goto make_route; 2865 } 2866 2867 fib_select_path(net, res, fl4, skb); 2868 2869 dev_out = FIB_RES_DEV(*res); 2870 2871 make_route: 2872 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2873 2874 out: 2875 return rth; 2876 } 2877 2878 static struct dst_ops ipv4_dst_blackhole_ops = { 2879 .family = AF_INET, 2880 .default_advmss = ipv4_default_advmss, 2881 .neigh_lookup = ipv4_neigh_lookup, 2882 .check = dst_blackhole_check, 2883 .cow_metrics = dst_blackhole_cow_metrics, 2884 .update_pmtu = dst_blackhole_update_pmtu, 2885 .redirect = dst_blackhole_redirect, 2886 .mtu = dst_blackhole_mtu, 2887 }; 2888 2889 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2890 { 2891 struct rtable *ort = dst_rtable(dst_orig); 2892 struct rtable *rt; 2893 2894 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2895 if (rt) { 2896 struct dst_entry *new = &rt->dst; 2897 2898 new->__use = 1; 2899 new->input = dst_discard; 2900 new->output = dst_discard_out; 2901 2902 new->dev = net->loopback_dev; 2903 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2904 2905 rt->rt_is_input = ort->rt_is_input; 2906 rt->rt_iif = ort->rt_iif; 2907 rt->rt_pmtu = ort->rt_pmtu; 2908 rt->rt_mtu_locked = ort->rt_mtu_locked; 2909 2910 rt->rt_genid = rt_genid_ipv4(net); 2911 rt->rt_flags = ort->rt_flags; 2912 rt->rt_type = ort->rt_type; 2913 rt->rt_uses_gateway = ort->rt_uses_gateway; 2914 rt->rt_gw_family = ort->rt_gw_family; 2915 if (rt->rt_gw_family == AF_INET) 2916 rt->rt_gw4 = ort->rt_gw4; 2917 else if (rt->rt_gw_family == AF_INET6) 2918 rt->rt_gw6 = ort->rt_gw6; 2919 } 2920 2921 dst_release(dst_orig); 2922 2923 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2924 } 2925 2926 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2927 const struct sock *sk) 2928 { 2929 struct rtable *rt = __ip_route_output_key(net, flp4); 2930 2931 if (IS_ERR(rt)) 2932 return rt; 2933 2934 if (flp4->flowi4_proto) { 2935 flp4->flowi4_oif = rt->dst.dev->ifindex; 2936 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2937 flowi4_to_flowi(flp4), 2938 sk, 0)); 2939 } 2940 2941 return rt; 2942 } 2943 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2944 2945 /* called with rcu_read_lock held */ 2946 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2947 struct rtable *rt, u32 table_id, dscp_t dscp, 2948 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2949 u32 seq, unsigned int flags) 2950 { 2951 struct rtmsg *r; 2952 struct nlmsghdr *nlh; 2953 unsigned long expires = 0; 2954 u32 error; 2955 u32 metrics[RTAX_MAX]; 2956 2957 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2958 if (!nlh) 2959 return -EMSGSIZE; 2960 2961 r = nlmsg_data(nlh); 2962 r->rtm_family = AF_INET; 2963 r->rtm_dst_len = 32; 2964 r->rtm_src_len = 0; 2965 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2966 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2967 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2968 goto nla_put_failure; 2969 r->rtm_type = rt->rt_type; 2970 r->rtm_scope = RT_SCOPE_UNIVERSE; 2971 r->rtm_protocol = RTPROT_UNSPEC; 2972 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2973 if (rt->rt_flags & RTCF_NOTIFY) 2974 r->rtm_flags |= RTM_F_NOTIFY; 2975 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2976 r->rtm_flags |= RTCF_DOREDIRECT; 2977 2978 if (nla_put_in_addr(skb, RTA_DST, dst)) 2979 goto nla_put_failure; 2980 if (src) { 2981 r->rtm_src_len = 32; 2982 if (nla_put_in_addr(skb, RTA_SRC, src)) 2983 goto nla_put_failure; 2984 } 2985 if (rt->dst.dev && 2986 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2987 goto nla_put_failure; 2988 if (lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2989 goto nla_put_failure; 2990 #ifdef CONFIG_IP_ROUTE_CLASSID 2991 if (rt->dst.tclassid && 2992 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2993 goto nla_put_failure; 2994 #endif 2995 if (fl4 && !rt_is_input_route(rt) && 2996 fl4->saddr != src) { 2997 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2998 goto nla_put_failure; 2999 } 3000 if (rt->rt_uses_gateway) { 3001 if (rt->rt_gw_family == AF_INET && 3002 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3003 goto nla_put_failure; 3004 } else if (rt->rt_gw_family == AF_INET6) { 3005 int alen = sizeof(struct in6_addr); 3006 struct nlattr *nla; 3007 struct rtvia *via; 3008 3009 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3010 if (!nla) 3011 goto nla_put_failure; 3012 3013 via = nla_data(nla); 3014 via->rtvia_family = AF_INET6; 3015 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3016 } 3017 } 3018 3019 expires = READ_ONCE(rt->dst.expires); 3020 if (expires) { 3021 unsigned long now = jiffies; 3022 3023 if (time_before(now, expires)) 3024 expires -= now; 3025 else 3026 expires = 0; 3027 } 3028 3029 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3030 if (rt->rt_pmtu && expires) 3031 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3032 if (rt->rt_mtu_locked && expires) 3033 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3034 if (rtnetlink_put_metrics(skb, metrics) < 0) 3035 goto nla_put_failure; 3036 3037 if (fl4) { 3038 if (fl4->flowi4_mark && 3039 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3040 goto nla_put_failure; 3041 3042 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3043 nla_put_u32(skb, RTA_UID, 3044 from_kuid_munged(current_user_ns(), 3045 fl4->flowi4_uid))) 3046 goto nla_put_failure; 3047 3048 if (rt_is_input_route(rt)) { 3049 #ifdef CONFIG_IP_MROUTE 3050 if (ipv4_is_multicast(dst) && 3051 !ipv4_is_local_multicast(dst) && 3052 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3053 int err = ipmr_get_route(net, skb, 3054 fl4->saddr, fl4->daddr, 3055 r, portid); 3056 3057 if (err <= 0) { 3058 if (err == 0) 3059 return 0; 3060 goto nla_put_failure; 3061 } 3062 } else 3063 #endif 3064 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3065 goto nla_put_failure; 3066 } 3067 } 3068 3069 error = rt->dst.error; 3070 3071 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3072 goto nla_put_failure; 3073 3074 nlmsg_end(skb, nlh); 3075 return 0; 3076 3077 nla_put_failure: 3078 nlmsg_cancel(skb, nlh); 3079 return -EMSGSIZE; 3080 } 3081 3082 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3083 struct netlink_callback *cb, u32 table_id, 3084 struct fnhe_hash_bucket *bucket, int genid, 3085 int *fa_index, int fa_start, unsigned int flags) 3086 { 3087 int i; 3088 3089 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3090 struct fib_nh_exception *fnhe; 3091 3092 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3093 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3094 struct rtable *rt; 3095 int err; 3096 3097 if (*fa_index < fa_start) 3098 goto next; 3099 3100 if (fnhe->fnhe_genid != genid) 3101 goto next; 3102 3103 if (fnhe->fnhe_expires && 3104 time_after(jiffies, fnhe->fnhe_expires)) 3105 goto next; 3106 3107 rt = rcu_dereference(fnhe->fnhe_rth_input); 3108 if (!rt) 3109 rt = rcu_dereference(fnhe->fnhe_rth_output); 3110 if (!rt) 3111 goto next; 3112 3113 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3114 table_id, 0, NULL, skb, 3115 NETLINK_CB(cb->skb).portid, 3116 cb->nlh->nlmsg_seq, flags); 3117 if (err) 3118 return err; 3119 next: 3120 (*fa_index)++; 3121 } 3122 } 3123 3124 return 0; 3125 } 3126 3127 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3128 u32 table_id, struct fib_info *fi, 3129 int *fa_index, int fa_start, unsigned int flags) 3130 { 3131 struct net *net = sock_net(cb->skb->sk); 3132 int nhsel, genid = fnhe_genid(net); 3133 3134 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3135 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3136 struct fnhe_hash_bucket *bucket; 3137 int err; 3138 3139 if (nhc->nhc_flags & RTNH_F_DEAD) 3140 continue; 3141 3142 rcu_read_lock(); 3143 bucket = rcu_dereference(nhc->nhc_exceptions); 3144 err = 0; 3145 if (bucket) 3146 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3147 genid, fa_index, fa_start, 3148 flags); 3149 rcu_read_unlock(); 3150 if (err) 3151 return err; 3152 } 3153 3154 return 0; 3155 } 3156 3157 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3158 u8 ip_proto, __be16 sport, 3159 __be16 dport) 3160 { 3161 struct sk_buff *skb; 3162 struct iphdr *iph; 3163 3164 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3165 if (!skb) 3166 return NULL; 3167 3168 /* Reserve room for dummy headers, this skb can pass 3169 * through good chunk of routing engine. 3170 */ 3171 skb_reset_mac_header(skb); 3172 skb_reset_network_header(skb); 3173 skb->protocol = htons(ETH_P_IP); 3174 iph = skb_put(skb, sizeof(struct iphdr)); 3175 iph->protocol = ip_proto; 3176 iph->saddr = src; 3177 iph->daddr = dst; 3178 iph->version = 0x4; 3179 iph->frag_off = 0; 3180 iph->ihl = 0x5; 3181 skb_set_transport_header(skb, skb->len); 3182 3183 switch (iph->protocol) { 3184 case IPPROTO_UDP: { 3185 struct udphdr *udph; 3186 3187 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3188 udph->source = sport; 3189 udph->dest = dport; 3190 udph->len = htons(sizeof(struct udphdr)); 3191 udph->check = 0; 3192 break; 3193 } 3194 case IPPROTO_TCP: { 3195 struct tcphdr *tcph; 3196 3197 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3198 tcph->source = sport; 3199 tcph->dest = dport; 3200 tcph->doff = sizeof(struct tcphdr) / 4; 3201 tcph->rst = 1; 3202 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3203 src, dst, 0); 3204 break; 3205 } 3206 case IPPROTO_ICMP: { 3207 struct icmphdr *icmph; 3208 3209 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3210 icmph->type = ICMP_ECHO; 3211 icmph->code = 0; 3212 } 3213 } 3214 3215 return skb; 3216 } 3217 3218 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3219 const struct nlmsghdr *nlh, 3220 struct nlattr **tb, 3221 struct netlink_ext_ack *extack) 3222 { 3223 struct rtmsg *rtm; 3224 int i, err; 3225 3226 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3227 if (!rtm) { 3228 NL_SET_ERR_MSG(extack, 3229 "ipv4: Invalid header for route get request"); 3230 return -EINVAL; 3231 } 3232 3233 if (!netlink_strict_get_check(skb)) 3234 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3235 rtm_ipv4_policy, extack); 3236 3237 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3238 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3239 rtm->rtm_table || rtm->rtm_protocol || 3240 rtm->rtm_scope || rtm->rtm_type) { 3241 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3242 return -EINVAL; 3243 } 3244 3245 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3246 RTM_F_LOOKUP_TABLE | 3247 RTM_F_FIB_MATCH)) { 3248 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3249 return -EINVAL; 3250 } 3251 3252 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3253 rtm_ipv4_policy, extack); 3254 if (err) 3255 return err; 3256 3257 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3258 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3259 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3260 return -EINVAL; 3261 } 3262 3263 for (i = 0; i <= RTA_MAX; i++) { 3264 if (!tb[i]) 3265 continue; 3266 3267 switch (i) { 3268 case RTA_IIF: 3269 case RTA_OIF: 3270 case RTA_SRC: 3271 case RTA_DST: 3272 case RTA_IP_PROTO: 3273 case RTA_SPORT: 3274 case RTA_DPORT: 3275 case RTA_MARK: 3276 case RTA_UID: 3277 break; 3278 default: 3279 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3280 return -EINVAL; 3281 } 3282 } 3283 3284 return 0; 3285 } 3286 3287 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3288 struct netlink_ext_ack *extack) 3289 { 3290 struct net *net = sock_net(in_skb->sk); 3291 struct nlattr *tb[RTA_MAX+1]; 3292 u32 table_id = RT_TABLE_MAIN; 3293 __be16 sport = 0, dport = 0; 3294 struct fib_result res = {}; 3295 u8 ip_proto = IPPROTO_UDP; 3296 struct rtable *rt = NULL; 3297 struct sk_buff *skb; 3298 struct rtmsg *rtm; 3299 struct flowi4 fl4 = {}; 3300 __be32 dst = 0; 3301 __be32 src = 0; 3302 dscp_t dscp; 3303 kuid_t uid; 3304 u32 iif; 3305 int err; 3306 int mark; 3307 3308 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3309 if (err < 0) 3310 return err; 3311 3312 rtm = nlmsg_data(nlh); 3313 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3314 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3315 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3316 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3317 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3318 if (tb[RTA_UID]) 3319 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3320 else 3321 uid = (iif ? INVALID_UID : current_uid()); 3322 3323 if (tb[RTA_IP_PROTO]) { 3324 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3325 &ip_proto, AF_INET, extack); 3326 if (err) 3327 return err; 3328 } 3329 3330 if (tb[RTA_SPORT]) 3331 sport = nla_get_be16(tb[RTA_SPORT]); 3332 3333 if (tb[RTA_DPORT]) 3334 dport = nla_get_be16(tb[RTA_DPORT]); 3335 3336 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3337 if (!skb) 3338 return -ENOBUFS; 3339 3340 fl4.daddr = dst; 3341 fl4.saddr = src; 3342 fl4.flowi4_dscp = dscp; 3343 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3344 fl4.flowi4_mark = mark; 3345 fl4.flowi4_uid = uid; 3346 if (sport) 3347 fl4.fl4_sport = sport; 3348 if (dport) 3349 fl4.fl4_dport = dport; 3350 fl4.flowi4_proto = ip_proto; 3351 3352 rcu_read_lock(); 3353 3354 if (iif) { 3355 struct net_device *dev; 3356 3357 dev = dev_get_by_index_rcu(net, iif); 3358 if (!dev) { 3359 err = -ENODEV; 3360 goto errout_rcu; 3361 } 3362 3363 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3364 skb->dev = dev; 3365 skb->mark = mark; 3366 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3367 &res) ? -EINVAL : 0; 3368 3369 rt = skb_rtable(skb); 3370 if (err == 0 && rt->dst.error) 3371 err = -rt->dst.error; 3372 } else { 3373 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3374 skb->dev = net->loopback_dev; 3375 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3376 err = 0; 3377 if (IS_ERR(rt)) 3378 err = PTR_ERR(rt); 3379 else 3380 skb_dst_set(skb, &rt->dst); 3381 } 3382 3383 if (err) 3384 goto errout_rcu; 3385 3386 if (rtm->rtm_flags & RTM_F_NOTIFY) 3387 rt->rt_flags |= RTCF_NOTIFY; 3388 3389 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3390 table_id = res.table ? res.table->tb_id : 0; 3391 3392 /* reset skb for netlink reply msg */ 3393 skb_trim(skb, 0); 3394 skb_reset_network_header(skb); 3395 skb_reset_transport_header(skb); 3396 skb_reset_mac_header(skb); 3397 3398 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3399 struct fib_rt_info fri; 3400 3401 if (!res.fi) { 3402 err = fib_props[res.type].error; 3403 if (!err) 3404 err = -EHOSTUNREACH; 3405 goto errout_rcu; 3406 } 3407 fri.fi = res.fi; 3408 fri.tb_id = table_id; 3409 fri.dst = res.prefix; 3410 fri.dst_len = res.prefixlen; 3411 fri.dscp = res.dscp; 3412 fri.type = rt->rt_type; 3413 fri.offload = 0; 3414 fri.trap = 0; 3415 fri.offload_failed = 0; 3416 if (res.fa_head) { 3417 struct fib_alias *fa; 3418 3419 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3420 u8 slen = 32 - fri.dst_len; 3421 3422 if (fa->fa_slen == slen && 3423 fa->tb_id == fri.tb_id && 3424 fa->fa_dscp == fri.dscp && 3425 fa->fa_info == res.fi && 3426 fa->fa_type == fri.type) { 3427 fri.offload = READ_ONCE(fa->offload); 3428 fri.trap = READ_ONCE(fa->trap); 3429 fri.offload_failed = 3430 READ_ONCE(fa->offload_failed); 3431 break; 3432 } 3433 } 3434 } 3435 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3436 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3437 } else { 3438 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3439 skb, NETLINK_CB(in_skb).portid, 3440 nlh->nlmsg_seq, 0); 3441 } 3442 if (err < 0) 3443 goto errout_rcu; 3444 3445 rcu_read_unlock(); 3446 3447 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3448 3449 errout_free: 3450 return err; 3451 errout_rcu: 3452 rcu_read_unlock(); 3453 kfree_skb(skb); 3454 goto errout_free; 3455 } 3456 3457 void ip_rt_multicast_event(struct in_device *in_dev) 3458 { 3459 rt_cache_flush(dev_net(in_dev->dev)); 3460 } 3461 3462 #ifdef CONFIG_SYSCTL 3463 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3464 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3465 static int ip_rt_gc_elasticity __read_mostly = 8; 3466 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3467 3468 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3469 void *buffer, size_t *lenp, loff_t *ppos) 3470 { 3471 struct net *net = (struct net *)__ctl->extra1; 3472 3473 if (write) { 3474 rt_cache_flush(net); 3475 fnhe_genid_bump(net); 3476 return 0; 3477 } 3478 3479 return -EINVAL; 3480 } 3481 3482 static struct ctl_table ipv4_route_table[] = { 3483 { 3484 .procname = "gc_thresh", 3485 .data = &ipv4_dst_ops.gc_thresh, 3486 .maxlen = sizeof(int), 3487 .mode = 0644, 3488 .proc_handler = proc_dointvec, 3489 }, 3490 { 3491 .procname = "max_size", 3492 .data = &ip_rt_max_size, 3493 .maxlen = sizeof(int), 3494 .mode = 0644, 3495 .proc_handler = proc_dointvec, 3496 }, 3497 { 3498 /* Deprecated. Use gc_min_interval_ms */ 3499 3500 .procname = "gc_min_interval", 3501 .data = &ip_rt_gc_min_interval, 3502 .maxlen = sizeof(int), 3503 .mode = 0644, 3504 .proc_handler = proc_dointvec_jiffies, 3505 }, 3506 { 3507 .procname = "gc_min_interval_ms", 3508 .data = &ip_rt_gc_min_interval, 3509 .maxlen = sizeof(int), 3510 .mode = 0644, 3511 .proc_handler = proc_dointvec_ms_jiffies, 3512 }, 3513 { 3514 .procname = "gc_timeout", 3515 .data = &ip_rt_gc_timeout, 3516 .maxlen = sizeof(int), 3517 .mode = 0644, 3518 .proc_handler = proc_dointvec_jiffies, 3519 }, 3520 { 3521 .procname = "gc_interval", 3522 .data = &ip_rt_gc_interval, 3523 .maxlen = sizeof(int), 3524 .mode = 0644, 3525 .proc_handler = proc_dointvec_jiffies, 3526 }, 3527 { 3528 .procname = "redirect_load", 3529 .data = &ip_rt_redirect_load, 3530 .maxlen = sizeof(int), 3531 .mode = 0644, 3532 .proc_handler = proc_dointvec, 3533 }, 3534 { 3535 .procname = "redirect_number", 3536 .data = &ip_rt_redirect_number, 3537 .maxlen = sizeof(int), 3538 .mode = 0644, 3539 .proc_handler = proc_dointvec, 3540 }, 3541 { 3542 .procname = "redirect_silence", 3543 .data = &ip_rt_redirect_silence, 3544 .maxlen = sizeof(int), 3545 .mode = 0644, 3546 .proc_handler = proc_dointvec, 3547 }, 3548 { 3549 .procname = "error_cost", 3550 .data = &ip_rt_error_cost, 3551 .maxlen = sizeof(int), 3552 .mode = 0644, 3553 .proc_handler = proc_dointvec, 3554 }, 3555 { 3556 .procname = "error_burst", 3557 .data = &ip_rt_error_burst, 3558 .maxlen = sizeof(int), 3559 .mode = 0644, 3560 .proc_handler = proc_dointvec, 3561 }, 3562 { 3563 .procname = "gc_elasticity", 3564 .data = &ip_rt_gc_elasticity, 3565 .maxlen = sizeof(int), 3566 .mode = 0644, 3567 .proc_handler = proc_dointvec, 3568 }, 3569 }; 3570 3571 static const char ipv4_route_flush_procname[] = "flush"; 3572 3573 static struct ctl_table ipv4_route_netns_table[] = { 3574 { 3575 .procname = ipv4_route_flush_procname, 3576 .maxlen = sizeof(int), 3577 .mode = 0200, 3578 .proc_handler = ipv4_sysctl_rtcache_flush, 3579 }, 3580 { 3581 .procname = "min_pmtu", 3582 .data = &init_net.ipv4.ip_rt_min_pmtu, 3583 .maxlen = sizeof(int), 3584 .mode = 0644, 3585 .proc_handler = proc_dointvec_minmax, 3586 .extra1 = &ip_min_valid_pmtu, 3587 }, 3588 { 3589 .procname = "mtu_expires", 3590 .data = &init_net.ipv4.ip_rt_mtu_expires, 3591 .maxlen = sizeof(int), 3592 .mode = 0644, 3593 .proc_handler = proc_dointvec_jiffies, 3594 }, 3595 { 3596 .procname = "min_adv_mss", 3597 .data = &init_net.ipv4.ip_rt_min_advmss, 3598 .maxlen = sizeof(int), 3599 .mode = 0644, 3600 .proc_handler = proc_dointvec, 3601 }, 3602 }; 3603 3604 static __net_init int sysctl_route_net_init(struct net *net) 3605 { 3606 struct ctl_table *tbl; 3607 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3608 3609 tbl = ipv4_route_netns_table; 3610 if (!net_eq(net, &init_net)) { 3611 int i; 3612 3613 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3614 if (!tbl) 3615 goto err_dup; 3616 3617 /* Don't export non-whitelisted sysctls to unprivileged users */ 3618 if (net->user_ns != &init_user_ns) { 3619 if (tbl[0].procname != ipv4_route_flush_procname) 3620 table_size = 0; 3621 } 3622 3623 /* Update the variables to point into the current struct net 3624 * except for the first element flush 3625 */ 3626 for (i = 1; i < table_size; i++) 3627 tbl[i].data += (void *)net - (void *)&init_net; 3628 } 3629 tbl[0].extra1 = net; 3630 3631 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3632 tbl, table_size); 3633 if (!net->ipv4.route_hdr) 3634 goto err_reg; 3635 return 0; 3636 3637 err_reg: 3638 if (tbl != ipv4_route_netns_table) 3639 kfree(tbl); 3640 err_dup: 3641 return -ENOMEM; 3642 } 3643 3644 static __net_exit void sysctl_route_net_exit(struct net *net) 3645 { 3646 const struct ctl_table *tbl; 3647 3648 tbl = net->ipv4.route_hdr->ctl_table_arg; 3649 unregister_net_sysctl_table(net->ipv4.route_hdr); 3650 BUG_ON(tbl == ipv4_route_netns_table); 3651 kfree(tbl); 3652 } 3653 3654 static __net_initdata struct pernet_operations sysctl_route_ops = { 3655 .init = sysctl_route_net_init, 3656 .exit = sysctl_route_net_exit, 3657 }; 3658 #endif 3659 3660 static __net_init int netns_ip_rt_init(struct net *net) 3661 { 3662 /* Set default value for namespaceified sysctls */ 3663 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3664 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3665 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3666 return 0; 3667 } 3668 3669 static struct pernet_operations __net_initdata ip_rt_ops = { 3670 .init = netns_ip_rt_init, 3671 }; 3672 3673 static __net_init int rt_genid_init(struct net *net) 3674 { 3675 atomic_set(&net->ipv4.rt_genid, 0); 3676 atomic_set(&net->fnhe_genid, 0); 3677 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3678 return 0; 3679 } 3680 3681 static __net_initdata struct pernet_operations rt_genid_ops = { 3682 .init = rt_genid_init, 3683 }; 3684 3685 static int __net_init ipv4_inetpeer_init(struct net *net) 3686 { 3687 struct inet_peer_base *bp = kmalloc_obj(*bp); 3688 3689 if (!bp) 3690 return -ENOMEM; 3691 inet_peer_base_init(bp); 3692 net->ipv4.peers = bp; 3693 return 0; 3694 } 3695 3696 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3697 { 3698 struct inet_peer_base *bp = net->ipv4.peers; 3699 3700 net->ipv4.peers = NULL; 3701 inetpeer_invalidate_tree(bp); 3702 kfree(bp); 3703 } 3704 3705 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3706 .init = ipv4_inetpeer_init, 3707 .exit = ipv4_inetpeer_exit, 3708 }; 3709 3710 #ifdef CONFIG_IP_ROUTE_CLASSID 3711 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3712 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3713 3714 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3715 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3716 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3717 }; 3718 3719 int __init ip_rt_init(void) 3720 { 3721 void *idents_hash; 3722 int cpu; 3723 3724 /* For modern hosts, this will use 2 MB of memory */ 3725 idents_hash = alloc_large_system_hash("IP idents", 3726 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3727 0, 3728 16, /* one bucket per 64 KB */ 3729 HASH_ZERO, 3730 NULL, 3731 &ip_idents_mask, 3732 2048, 3733 256*1024); 3734 3735 ip_idents = idents_hash; 3736 3737 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3738 3739 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3740 3741 for_each_possible_cpu(cpu) { 3742 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3743 3744 INIT_LIST_HEAD(&ul->head); 3745 spin_lock_init(&ul->lock); 3746 } 3747 #ifdef CONFIG_IP_ROUTE_CLASSID 3748 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3749 if (!ip_rt_acct) 3750 panic("IP: failed to allocate ip_rt_acct\n"); 3751 #endif 3752 3753 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3754 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3755 3756 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3757 3758 if (dst_entries_init(&ipv4_dst_ops) < 0) 3759 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3760 3761 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3762 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3763 3764 ipv4_dst_ops.gc_thresh = ~0; 3765 ip_rt_max_size = INT_MAX; 3766 3767 devinet_init(); 3768 ip_fib_init(); 3769 3770 if (ip_rt_proc_init()) 3771 pr_err("Unable to create route proc files\n"); 3772 #ifdef CONFIG_XFRM 3773 xfrm_init(); 3774 xfrm4_init(); 3775 #endif 3776 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3777 3778 #ifdef CONFIG_SYSCTL 3779 register_pernet_subsys(&sysctl_route_ops); 3780 #endif 3781 register_pernet_subsys(&ip_rt_ops); 3782 register_pernet_subsys(&rt_genid_ops); 3783 register_pernet_subsys(&ipv4_inetpeer_ops); 3784 return 0; 3785 } 3786 3787 #ifdef CONFIG_SYSCTL 3788 /* 3789 * We really need to sanitize the damn ipv4 init order, then all 3790 * this nonsense will go away. 3791 */ 3792 void __init ip_static_sysctl_init(void) 3793 { 3794 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3795 } 3796 #endif 3797