1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_FL_TOS(oldflp4) \ 110 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 111 112 #define RT_GC_TIMEOUT (300*HZ) 113 114 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 115 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 116 #define DEFAULT_MIN_ADVMSS 256 117 static int ip_rt_max_size; 118 static int ip_rt_redirect_number __read_mostly = 9; 119 static int ip_rt_redirect_load __read_mostly = HZ / 50; 120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 121 static int ip_rt_error_cost __read_mostly = HZ; 122 static int ip_rt_error_burst __read_mostly = 5 * HZ; 123 124 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 125 126 /* 127 * Interface to generic destination cache. 128 */ 129 130 INDIRECT_CALLABLE_SCOPE 131 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 133 INDIRECT_CALLABLE_SCOPE 134 unsigned int ipv4_mtu(const struct dst_entry *dst); 135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 136 static void ipv4_link_failure(struct sk_buff *skb); 137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 138 struct sk_buff *skb, u32 mtu, 139 bool confirm_neigh); 140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 141 struct sk_buff *skb); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 144 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 145 { 146 WARN_ON(1); 147 return NULL; 148 } 149 150 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 151 struct sk_buff *skb, 152 const void *daddr); 153 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 154 155 static struct dst_ops ipv4_dst_ops = { 156 .family = AF_INET, 157 .check = ipv4_dst_check, 158 .default_advmss = ipv4_default_advmss, 159 .mtu = ipv4_mtu, 160 .cow_metrics = ipv4_cow_metrics, 161 .destroy = ipv4_dst_destroy, 162 .negative_advice = ipv4_negative_advice, 163 .link_failure = ipv4_link_failure, 164 .update_pmtu = ip_rt_update_pmtu, 165 .redirect = ip_do_redirect, 166 .local_out = __ip_local_out, 167 .neigh_lookup = ipv4_neigh_lookup, 168 .confirm_neigh = ipv4_confirm_neigh, 169 }; 170 171 #define ECN_OR_COST(class) TC_PRIO_##class 172 173 const __u8 ip_tos2prio[16] = { 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BESTEFFORT, 177 ECN_OR_COST(BESTEFFORT), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_BULK, 181 ECN_OR_COST(BULK), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE, 185 ECN_OR_COST(INTERACTIVE), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK), 188 TC_PRIO_INTERACTIVE_BULK, 189 ECN_OR_COST(INTERACTIVE_BULK) 190 }; 191 EXPORT_SYMBOL(ip_tos2prio); 192 193 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 196 #ifdef CONFIG_PROC_FS 197 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 198 { 199 if (*pos) 200 return NULL; 201 return SEQ_START_TOKEN; 202 } 203 204 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 205 { 206 ++*pos; 207 return NULL; 208 } 209 210 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 211 { 212 } 213 214 static int rt_cache_seq_show(struct seq_file *seq, void *v) 215 { 216 if (v == SEQ_START_TOKEN) 217 seq_printf(seq, "%-127s\n", 218 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 219 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 220 "HHUptod\tSpecDst"); 221 return 0; 222 } 223 224 static const struct seq_operations rt_cache_seq_ops = { 225 .start = rt_cache_seq_start, 226 .next = rt_cache_seq_next, 227 .stop = rt_cache_seq_stop, 228 .show = rt_cache_seq_show, 229 }; 230 231 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 232 { 233 int cpu; 234 235 if (*pos == 0) 236 return SEQ_START_TOKEN; 237 238 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 239 if (!cpu_possible(cpu)) 240 continue; 241 *pos = cpu+1; 242 return &per_cpu(rt_cache_stat, cpu); 243 } 244 return NULL; 245 } 246 247 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 248 { 249 int cpu; 250 251 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 252 if (!cpu_possible(cpu)) 253 continue; 254 *pos = cpu+1; 255 return &per_cpu(rt_cache_stat, cpu); 256 } 257 (*pos)++; 258 return NULL; 259 260 } 261 262 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 263 { 264 265 } 266 267 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 268 { 269 struct rt_cache_stat *st = v; 270 271 if (v == SEQ_START_TOKEN) { 272 seq_puts(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 273 return 0; 274 } 275 276 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 277 "%08x %08x %08x %08x %08x %08x " 278 "%08x %08x %08x %08x\n", 279 dst_entries_get_slow(&ipv4_dst_ops), 280 0, /* st->in_hit */ 281 st->in_slow_tot, 282 st->in_slow_mc, 283 st->in_no_route, 284 st->in_brd, 285 st->in_martian_dst, 286 st->in_martian_src, 287 288 0, /* st->out_hit */ 289 st->out_slow_tot, 290 st->out_slow_mc, 291 292 0, /* st->gc_total */ 293 0, /* st->gc_ignored */ 294 0, /* st->gc_goal_miss */ 295 0, /* st->gc_dst_overflow */ 296 0, /* st->in_hlist_search */ 297 0 /* st->out_hlist_search */ 298 ); 299 return 0; 300 } 301 302 static const struct seq_operations rt_cpu_seq_ops = { 303 .start = rt_cpu_seq_start, 304 .next = rt_cpu_seq_next, 305 .stop = rt_cpu_seq_stop, 306 .show = rt_cpu_seq_show, 307 }; 308 309 #ifdef CONFIG_IP_ROUTE_CLASSID 310 static int rt_acct_proc_show(struct seq_file *m, void *v) 311 { 312 struct ip_rt_acct *dst, *src; 313 unsigned int i, j; 314 315 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 316 if (!dst) 317 return -ENOMEM; 318 319 for_each_possible_cpu(i) { 320 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 321 for (j = 0; j < 256; j++) { 322 dst[j].o_bytes += src[j].o_bytes; 323 dst[j].o_packets += src[j].o_packets; 324 dst[j].i_bytes += src[j].i_bytes; 325 dst[j].i_packets += src[j].i_packets; 326 } 327 } 328 329 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 330 kfree(dst); 331 return 0; 332 } 333 #endif 334 335 static int __net_init ip_rt_do_proc_init(struct net *net) 336 { 337 struct proc_dir_entry *pde; 338 339 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 340 &rt_cache_seq_ops); 341 if (!pde) 342 goto err1; 343 344 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 345 &rt_cpu_seq_ops); 346 if (!pde) 347 goto err2; 348 349 #ifdef CONFIG_IP_ROUTE_CLASSID 350 pde = proc_create_single("rt_acct", 0, net->proc_net, 351 rt_acct_proc_show); 352 if (!pde) 353 goto err3; 354 #endif 355 return 0; 356 357 #ifdef CONFIG_IP_ROUTE_CLASSID 358 err3: 359 remove_proc_entry("rt_cache", net->proc_net_stat); 360 #endif 361 err2: 362 remove_proc_entry("rt_cache", net->proc_net); 363 err1: 364 return -ENOMEM; 365 } 366 367 static void __net_exit ip_rt_do_proc_exit(struct net *net) 368 { 369 remove_proc_entry("rt_cache", net->proc_net_stat); 370 remove_proc_entry("rt_cache", net->proc_net); 371 #ifdef CONFIG_IP_ROUTE_CLASSID 372 remove_proc_entry("rt_acct", net->proc_net); 373 #endif 374 } 375 376 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 377 .init = ip_rt_do_proc_init, 378 .exit = ip_rt_do_proc_exit, 379 }; 380 381 static int __init ip_rt_proc_init(void) 382 { 383 return register_pernet_subsys(&ip_rt_proc_ops); 384 } 385 386 #else 387 static inline int ip_rt_proc_init(void) 388 { 389 return 0; 390 } 391 #endif /* CONFIG_PROC_FS */ 392 393 static inline bool rt_is_expired(const struct rtable *rth) 394 { 395 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 396 } 397 398 void rt_cache_flush(struct net *net) 399 { 400 rt_genid_bump_ipv4(net); 401 } 402 403 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 404 struct sk_buff *skb, 405 const void *daddr) 406 { 407 const struct rtable *rt = container_of(dst, struct rtable, dst); 408 struct net_device *dev = dst->dev; 409 struct neighbour *n; 410 411 rcu_read_lock_bh(); 412 413 if (likely(rt->rt_gw_family == AF_INET)) { 414 n = ip_neigh_gw4(dev, rt->rt_gw4); 415 } else if (rt->rt_gw_family == AF_INET6) { 416 n = ip_neigh_gw6(dev, &rt->rt_gw6); 417 } else { 418 __be32 pkey; 419 420 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 421 n = ip_neigh_gw4(dev, pkey); 422 } 423 424 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 425 n = NULL; 426 427 rcu_read_unlock_bh(); 428 429 return n; 430 } 431 432 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 433 { 434 const struct rtable *rt = container_of(dst, struct rtable, dst); 435 struct net_device *dev = dst->dev; 436 const __be32 *pkey = daddr; 437 438 if (rt->rt_gw_family == AF_INET) { 439 pkey = (const __be32 *)&rt->rt_gw4; 440 } else if (rt->rt_gw_family == AF_INET6) { 441 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 442 } else if (!daddr || 443 (rt->rt_flags & 444 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 445 return; 446 } 447 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 448 } 449 450 /* Hash tables of size 2048..262144 depending on RAM size. 451 * Each bucket uses 8 bytes. 452 */ 453 static u32 ip_idents_mask __read_mostly; 454 static atomic_t *ip_idents __read_mostly; 455 static u32 *ip_tstamps __read_mostly; 456 457 /* In order to protect privacy, we add a perturbation to identifiers 458 * if one generator is seldom used. This makes hard for an attacker 459 * to infer how many packets were sent between two points in time. 460 */ 461 static u32 ip_idents_reserve(u32 hash, int segs) 462 { 463 u32 bucket, old, now = (u32)jiffies; 464 atomic_t *p_id; 465 u32 *p_tstamp; 466 u32 delta = 0; 467 468 bucket = hash & ip_idents_mask; 469 p_tstamp = ip_tstamps + bucket; 470 p_id = ip_idents + bucket; 471 old = READ_ONCE(*p_tstamp); 472 473 if (old != now && cmpxchg(p_tstamp, old, now) == old) 474 delta = prandom_u32_max(now - old); 475 476 /* If UBSAN reports an error there, please make sure your compiler 477 * supports -fno-strict-overflow before reporting it that was a bug 478 * in UBSAN, and it has been fixed in GCC-8. 479 */ 480 return atomic_add_return(segs + delta, p_id) - segs; 481 } 482 483 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 484 { 485 u32 hash, id; 486 487 /* Note the following code is not safe, but this is okay. */ 488 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 489 get_random_bytes(&net->ipv4.ip_id_key, 490 sizeof(net->ipv4.ip_id_key)); 491 492 hash = siphash_3u32((__force u32)iph->daddr, 493 (__force u32)iph->saddr, 494 iph->protocol, 495 &net->ipv4.ip_id_key); 496 id = ip_idents_reserve(hash, segs); 497 iph->id = htons(id); 498 } 499 EXPORT_SYMBOL(__ip_select_ident); 500 501 static void ip_rt_fix_tos(struct flowi4 *fl4) 502 { 503 __u8 tos = RT_FL_TOS(fl4); 504 505 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 506 if (tos & RTO_ONLINK) 507 fl4->flowi4_scope = RT_SCOPE_LINK; 508 } 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 const struct inet_sock *inet = inet_sk(sk); 519 520 oif = sk->sk_bound_dev_if; 521 mark = sk->sk_mark; 522 tos = ip_sock_rt_tos(sk); 523 scope = ip_sock_rt_scope(sk); 524 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 525 } 526 527 flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope, 528 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 529 sock_net_uid(net, sk)); 530 } 531 532 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 533 const struct sock *sk) 534 { 535 const struct net *net = dev_net(skb->dev); 536 const struct iphdr *iph = ip_hdr(skb); 537 int oif = skb->dev->ifindex; 538 u8 prot = iph->protocol; 539 u32 mark = skb->mark; 540 __u8 tos = iph->tos; 541 542 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 543 } 544 545 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 546 { 547 const struct inet_sock *inet = inet_sk(sk); 548 const struct ip_options_rcu *inet_opt; 549 __be32 daddr = inet->inet_daddr; 550 551 rcu_read_lock(); 552 inet_opt = rcu_dereference(inet->inet_opt); 553 if (inet_opt && inet_opt->opt.srr) 554 daddr = inet_opt->opt.faddr; 555 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 556 ip_sock_rt_tos(sk) & IPTOS_RT_MASK, 557 ip_sock_rt_scope(sk), 558 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 559 inet_sk_flowi_flags(sk), 560 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 561 rcu_read_unlock(); 562 } 563 564 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 565 const struct sk_buff *skb) 566 { 567 if (skb) 568 build_skb_flow_key(fl4, skb, sk); 569 else 570 build_sk_flow_key(fl4, sk); 571 } 572 573 static DEFINE_SPINLOCK(fnhe_lock); 574 575 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 576 { 577 struct rtable *rt; 578 579 rt = rcu_dereference(fnhe->fnhe_rth_input); 580 if (rt) { 581 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 582 dst_dev_put(&rt->dst); 583 dst_release(&rt->dst); 584 } 585 rt = rcu_dereference(fnhe->fnhe_rth_output); 586 if (rt) { 587 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 588 dst_dev_put(&rt->dst); 589 dst_release(&rt->dst); 590 } 591 } 592 593 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 594 { 595 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 596 struct fib_nh_exception *fnhe, *oldest = NULL; 597 598 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 599 fnhe = rcu_dereference_protected(*fnhe_p, 600 lockdep_is_held(&fnhe_lock)); 601 if (!fnhe) 602 break; 603 if (!oldest || 604 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 605 oldest = fnhe; 606 oldest_p = fnhe_p; 607 } 608 } 609 fnhe_flush_routes(oldest); 610 *oldest_p = oldest->fnhe_next; 611 kfree_rcu(oldest, rcu); 612 } 613 614 static u32 fnhe_hashfun(__be32 daddr) 615 { 616 static siphash_aligned_key_t fnhe_hash_key; 617 u64 hval; 618 619 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 620 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 621 return hash_64(hval, FNHE_HASH_SHIFT); 622 } 623 624 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 625 { 626 rt->rt_pmtu = fnhe->fnhe_pmtu; 627 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 628 rt->dst.expires = fnhe->fnhe_expires; 629 630 if (fnhe->fnhe_gw) { 631 rt->rt_flags |= RTCF_REDIRECTED; 632 rt->rt_uses_gateway = 1; 633 rt->rt_gw_family = AF_INET; 634 rt->rt_gw4 = fnhe->fnhe_gw; 635 } 636 } 637 638 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 639 __be32 gw, u32 pmtu, bool lock, 640 unsigned long expires) 641 { 642 struct fnhe_hash_bucket *hash; 643 struct fib_nh_exception *fnhe; 644 struct rtable *rt; 645 u32 genid, hval; 646 unsigned int i; 647 int depth; 648 649 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 650 hval = fnhe_hashfun(daddr); 651 652 spin_lock_bh(&fnhe_lock); 653 654 hash = rcu_dereference(nhc->nhc_exceptions); 655 if (!hash) { 656 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 657 if (!hash) 658 goto out_unlock; 659 rcu_assign_pointer(nhc->nhc_exceptions, hash); 660 } 661 662 hash += hval; 663 664 depth = 0; 665 for (fnhe = rcu_dereference(hash->chain); fnhe; 666 fnhe = rcu_dereference(fnhe->fnhe_next)) { 667 if (fnhe->fnhe_daddr == daddr) 668 break; 669 depth++; 670 } 671 672 if (fnhe) { 673 if (fnhe->fnhe_genid != genid) 674 fnhe->fnhe_genid = genid; 675 if (gw) 676 fnhe->fnhe_gw = gw; 677 if (pmtu) { 678 fnhe->fnhe_pmtu = pmtu; 679 fnhe->fnhe_mtu_locked = lock; 680 } 681 fnhe->fnhe_expires = max(1UL, expires); 682 /* Update all cached dsts too */ 683 rt = rcu_dereference(fnhe->fnhe_rth_input); 684 if (rt) 685 fill_route_from_fnhe(rt, fnhe); 686 rt = rcu_dereference(fnhe->fnhe_rth_output); 687 if (rt) 688 fill_route_from_fnhe(rt, fnhe); 689 } else { 690 /* Randomize max depth to avoid some side channels attacks. */ 691 int max_depth = FNHE_RECLAIM_DEPTH + 692 prandom_u32_max(FNHE_RECLAIM_DEPTH); 693 694 while (depth > max_depth) { 695 fnhe_remove_oldest(hash); 696 depth--; 697 } 698 699 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 700 if (!fnhe) 701 goto out_unlock; 702 703 fnhe->fnhe_next = hash->chain; 704 705 fnhe->fnhe_genid = genid; 706 fnhe->fnhe_daddr = daddr; 707 fnhe->fnhe_gw = gw; 708 fnhe->fnhe_pmtu = pmtu; 709 fnhe->fnhe_mtu_locked = lock; 710 fnhe->fnhe_expires = max(1UL, expires); 711 712 rcu_assign_pointer(hash->chain, fnhe); 713 714 /* Exception created; mark the cached routes for the nexthop 715 * stale, so anyone caching it rechecks if this exception 716 * applies to them. 717 */ 718 rt = rcu_dereference(nhc->nhc_rth_input); 719 if (rt) 720 rt->dst.obsolete = DST_OBSOLETE_KILL; 721 722 for_each_possible_cpu(i) { 723 struct rtable __rcu **prt; 724 725 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 726 rt = rcu_dereference(*prt); 727 if (rt) 728 rt->dst.obsolete = DST_OBSOLETE_KILL; 729 } 730 } 731 732 fnhe->fnhe_stamp = jiffies; 733 734 out_unlock: 735 spin_unlock_bh(&fnhe_lock); 736 } 737 738 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 739 bool kill_route) 740 { 741 __be32 new_gw = icmp_hdr(skb)->un.gateway; 742 __be32 old_gw = ip_hdr(skb)->saddr; 743 struct net_device *dev = skb->dev; 744 struct in_device *in_dev; 745 struct fib_result res; 746 struct neighbour *n; 747 struct net *net; 748 749 switch (icmp_hdr(skb)->code & 7) { 750 case ICMP_REDIR_NET: 751 case ICMP_REDIR_NETTOS: 752 case ICMP_REDIR_HOST: 753 case ICMP_REDIR_HOSTTOS: 754 break; 755 756 default: 757 return; 758 } 759 760 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 761 return; 762 763 in_dev = __in_dev_get_rcu(dev); 764 if (!in_dev) 765 return; 766 767 net = dev_net(dev); 768 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 769 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 770 ipv4_is_zeronet(new_gw)) 771 goto reject_redirect; 772 773 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 774 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 775 goto reject_redirect; 776 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 777 goto reject_redirect; 778 } else { 779 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 780 goto reject_redirect; 781 } 782 783 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 784 if (!n) 785 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 786 if (!IS_ERR(n)) { 787 if (!(n->nud_state & NUD_VALID)) { 788 neigh_event_send(n, NULL); 789 } else { 790 if (fib_lookup(net, fl4, &res, 0) == 0) { 791 struct fib_nh_common *nhc; 792 793 fib_select_path(net, &res, fl4, skb); 794 nhc = FIB_RES_NHC(res); 795 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 796 0, false, 797 jiffies + ip_rt_gc_timeout); 798 } 799 if (kill_route) 800 rt->dst.obsolete = DST_OBSOLETE_KILL; 801 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 802 } 803 neigh_release(n); 804 } 805 return; 806 807 reject_redirect: 808 #ifdef CONFIG_IP_ROUTE_VERBOSE 809 if (IN_DEV_LOG_MARTIANS(in_dev)) { 810 const struct iphdr *iph = (const struct iphdr *) skb->data; 811 __be32 daddr = iph->daddr; 812 __be32 saddr = iph->saddr; 813 814 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 815 " Advised path = %pI4 -> %pI4\n", 816 &old_gw, dev->name, &new_gw, 817 &saddr, &daddr); 818 } 819 #endif 820 ; 821 } 822 823 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 824 { 825 struct rtable *rt; 826 struct flowi4 fl4; 827 const struct iphdr *iph = (const struct iphdr *) skb->data; 828 struct net *net = dev_net(skb->dev); 829 int oif = skb->dev->ifindex; 830 u8 prot = iph->protocol; 831 u32 mark = skb->mark; 832 __u8 tos = iph->tos; 833 834 rt = (struct rtable *) dst; 835 836 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 837 __ip_do_redirect(rt, skb, &fl4, true); 838 } 839 840 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 841 { 842 struct rtable *rt = (struct rtable *)dst; 843 struct dst_entry *ret = dst; 844 845 if (rt) { 846 if (dst->obsolete > 0) { 847 ip_rt_put(rt); 848 ret = NULL; 849 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 850 rt->dst.expires) { 851 ip_rt_put(rt); 852 ret = NULL; 853 } 854 } 855 return ret; 856 } 857 858 /* 859 * Algorithm: 860 * 1. The first ip_rt_redirect_number redirects are sent 861 * with exponential backoff, then we stop sending them at all, 862 * assuming that the host ignores our redirects. 863 * 2. If we did not see packets requiring redirects 864 * during ip_rt_redirect_silence, we assume that the host 865 * forgot redirected route and start to send redirects again. 866 * 867 * This algorithm is much cheaper and more intelligent than dumb load limiting 868 * in icmp.c. 869 * 870 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 871 * and "frag. need" (breaks PMTU discovery) in icmp.c. 872 */ 873 874 void ip_rt_send_redirect(struct sk_buff *skb) 875 { 876 struct rtable *rt = skb_rtable(skb); 877 struct in_device *in_dev; 878 struct inet_peer *peer; 879 struct net *net; 880 int log_martians; 881 int vif; 882 883 rcu_read_lock(); 884 in_dev = __in_dev_get_rcu(rt->dst.dev); 885 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 886 rcu_read_unlock(); 887 return; 888 } 889 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 890 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 891 rcu_read_unlock(); 892 893 net = dev_net(rt->dst.dev); 894 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 895 if (!peer) { 896 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 897 rt_nexthop(rt, ip_hdr(skb)->daddr)); 898 return; 899 } 900 901 /* No redirected packets during ip_rt_redirect_silence; 902 * reset the algorithm. 903 */ 904 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 905 peer->rate_tokens = 0; 906 peer->n_redirects = 0; 907 } 908 909 /* Too many ignored redirects; do not send anything 910 * set dst.rate_last to the last seen redirected packet. 911 */ 912 if (peer->n_redirects >= ip_rt_redirect_number) { 913 peer->rate_last = jiffies; 914 goto out_put_peer; 915 } 916 917 /* Check for load limit; set rate_last to the latest sent 918 * redirect. 919 */ 920 if (peer->n_redirects == 0 || 921 time_after(jiffies, 922 (peer->rate_last + 923 (ip_rt_redirect_load << peer->n_redirects)))) { 924 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 925 926 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 927 peer->rate_last = jiffies; 928 ++peer->n_redirects; 929 #ifdef CONFIG_IP_ROUTE_VERBOSE 930 if (log_martians && 931 peer->n_redirects == ip_rt_redirect_number) 932 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 933 &ip_hdr(skb)->saddr, inet_iif(skb), 934 &ip_hdr(skb)->daddr, &gw); 935 #endif 936 } 937 out_put_peer: 938 inet_putpeer(peer); 939 } 940 941 static int ip_error(struct sk_buff *skb) 942 { 943 struct rtable *rt = skb_rtable(skb); 944 struct net_device *dev = skb->dev; 945 struct in_device *in_dev; 946 struct inet_peer *peer; 947 unsigned long now; 948 struct net *net; 949 SKB_DR(reason); 950 bool send; 951 int code; 952 953 if (netif_is_l3_master(skb->dev)) { 954 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 955 if (!dev) 956 goto out; 957 } 958 959 in_dev = __in_dev_get_rcu(dev); 960 961 /* IP on this device is disabled. */ 962 if (!in_dev) 963 goto out; 964 965 net = dev_net(rt->dst.dev); 966 if (!IN_DEV_FORWARD(in_dev)) { 967 switch (rt->dst.error) { 968 case EHOSTUNREACH: 969 SKB_DR_SET(reason, IP_INADDRERRORS); 970 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 971 break; 972 973 case ENETUNREACH: 974 SKB_DR_SET(reason, IP_INNOROUTES); 975 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 976 break; 977 } 978 goto out; 979 } 980 981 switch (rt->dst.error) { 982 case EINVAL: 983 default: 984 goto out; 985 case EHOSTUNREACH: 986 code = ICMP_HOST_UNREACH; 987 break; 988 case ENETUNREACH: 989 code = ICMP_NET_UNREACH; 990 SKB_DR_SET(reason, IP_INNOROUTES); 991 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 992 break; 993 case EACCES: 994 code = ICMP_PKT_FILTERED; 995 break; 996 } 997 998 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 999 l3mdev_master_ifindex(skb->dev), 1); 1000 1001 send = true; 1002 if (peer) { 1003 now = jiffies; 1004 peer->rate_tokens += now - peer->rate_last; 1005 if (peer->rate_tokens > ip_rt_error_burst) 1006 peer->rate_tokens = ip_rt_error_burst; 1007 peer->rate_last = now; 1008 if (peer->rate_tokens >= ip_rt_error_cost) 1009 peer->rate_tokens -= ip_rt_error_cost; 1010 else 1011 send = false; 1012 inet_putpeer(peer); 1013 } 1014 if (send) 1015 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1016 1017 out: kfree_skb_reason(skb, reason); 1018 return 0; 1019 } 1020 1021 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1022 { 1023 struct dst_entry *dst = &rt->dst; 1024 struct net *net = dev_net(dst->dev); 1025 struct fib_result res; 1026 bool lock = false; 1027 u32 old_mtu; 1028 1029 if (ip_mtu_locked(dst)) 1030 return; 1031 1032 old_mtu = ipv4_mtu(dst); 1033 if (old_mtu < mtu) 1034 return; 1035 1036 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, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1043 return; 1044 1045 rcu_read_lock(); 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 nhc = FIB_RES_NHC(res); 1051 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1052 jiffies + net->ipv4.ip_rt_mtu_expires); 1053 } 1054 rcu_read_unlock(); 1055 } 1056 1057 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1058 struct sk_buff *skb, u32 mtu, 1059 bool confirm_neigh) 1060 { 1061 struct rtable *rt = (struct rtable *) dst; 1062 struct flowi4 fl4; 1063 1064 ip_rt_build_flow_key(&fl4, sk, skb); 1065 1066 /* Don't make lookup fail for bridged encapsulations */ 1067 if (skb && netif_is_any_bridge_port(skb->dev)) 1068 fl4.flowi4_oif = 0; 1069 1070 __ip_rt_update_pmtu(rt, &fl4, mtu); 1071 } 1072 1073 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1074 int oif, u8 protocol) 1075 { 1076 const struct iphdr *iph = (const struct iphdr *)skb->data; 1077 struct flowi4 fl4; 1078 struct rtable *rt; 1079 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1080 1081 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1082 0); 1083 rt = __ip_route_output_key(net, &fl4); 1084 if (!IS_ERR(rt)) { 1085 __ip_rt_update_pmtu(rt, &fl4, mtu); 1086 ip_rt_put(rt); 1087 } 1088 } 1089 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1090 1091 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1092 { 1093 const struct iphdr *iph = (const struct iphdr *)skb->data; 1094 struct flowi4 fl4; 1095 struct rtable *rt; 1096 1097 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1098 1099 if (!fl4.flowi4_mark) 1100 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1101 1102 rt = __ip_route_output_key(sock_net(sk), &fl4); 1103 if (!IS_ERR(rt)) { 1104 __ip_rt_update_pmtu(rt, &fl4, mtu); 1105 ip_rt_put(rt); 1106 } 1107 } 1108 1109 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1110 { 1111 const struct iphdr *iph = (const struct iphdr *)skb->data; 1112 struct flowi4 fl4; 1113 struct rtable *rt; 1114 struct dst_entry *odst = NULL; 1115 bool new = false; 1116 struct net *net = sock_net(sk); 1117 1118 bh_lock_sock(sk); 1119 1120 if (!ip_sk_accept_pmtu(sk)) 1121 goto out; 1122 1123 odst = sk_dst_get(sk); 1124 1125 if (sock_owned_by_user(sk) || !odst) { 1126 __ipv4_sk_update_pmtu(skb, sk, mtu); 1127 goto out; 1128 } 1129 1130 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1131 1132 rt = (struct rtable *)odst; 1133 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1134 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1135 if (IS_ERR(rt)) 1136 goto out; 1137 1138 new = true; 1139 } 1140 1141 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1142 1143 if (!dst_check(&rt->dst, 0)) { 1144 if (new) 1145 dst_release(&rt->dst); 1146 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 if (new) 1155 sk_dst_set(sk, &rt->dst); 1156 1157 out: 1158 bh_unlock_sock(sk); 1159 dst_release(odst); 1160 } 1161 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1162 1163 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1164 int oif, u8 protocol) 1165 { 1166 const struct iphdr *iph = (const struct iphdr *)skb->data; 1167 struct flowi4 fl4; 1168 struct rtable *rt; 1169 1170 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1171 rt = __ip_route_output_key(net, &fl4); 1172 if (!IS_ERR(rt)) { 1173 __ip_do_redirect(rt, skb, &fl4, false); 1174 ip_rt_put(rt); 1175 } 1176 } 1177 EXPORT_SYMBOL_GPL(ipv4_redirect); 1178 1179 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1180 { 1181 const struct iphdr *iph = (const struct iphdr *)skb->data; 1182 struct flowi4 fl4; 1183 struct rtable *rt; 1184 struct net *net = sock_net(sk); 1185 1186 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1187 rt = __ip_route_output_key(net, &fl4); 1188 if (!IS_ERR(rt)) { 1189 __ip_do_redirect(rt, skb, &fl4, false); 1190 ip_rt_put(rt); 1191 } 1192 } 1193 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1194 1195 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1196 u32 cookie) 1197 { 1198 struct rtable *rt = (struct rtable *) dst; 1199 1200 /* All IPV4 dsts are created with ->obsolete set to the value 1201 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1202 * into this function always. 1203 * 1204 * When a PMTU/redirect information update invalidates a route, 1205 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1206 * DST_OBSOLETE_DEAD. 1207 */ 1208 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1209 return NULL; 1210 return dst; 1211 } 1212 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1213 1214 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1215 { 1216 struct ip_options opt; 1217 int res; 1218 1219 /* Recompile ip options since IPCB may not be valid anymore. 1220 * Also check we have a reasonable ipv4 header. 1221 */ 1222 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1223 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1224 return; 1225 1226 memset(&opt, 0, sizeof(opt)); 1227 if (ip_hdr(skb)->ihl > 5) { 1228 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1229 return; 1230 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1231 1232 rcu_read_lock(); 1233 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1234 rcu_read_unlock(); 1235 1236 if (res) 1237 return; 1238 } 1239 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1240 } 1241 1242 static void ipv4_link_failure(struct sk_buff *skb) 1243 { 1244 struct rtable *rt; 1245 1246 ipv4_send_dest_unreach(skb); 1247 1248 rt = skb_rtable(skb); 1249 if (rt) 1250 dst_set_expires(&rt->dst, 0); 1251 } 1252 1253 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1254 { 1255 pr_debug("%s: %pI4 -> %pI4, %s\n", 1256 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1257 skb->dev ? skb->dev->name : "?"); 1258 kfree_skb(skb); 1259 WARN_ON(1); 1260 return 0; 1261 } 1262 1263 /* 1264 * We do not cache source address of outgoing interface, 1265 * because it is used only by IP RR, TS and SRR options, 1266 * so that it out of fast path. 1267 * 1268 * BTW remember: "addr" is allowed to be not aligned 1269 * in IP options! 1270 */ 1271 1272 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1273 { 1274 __be32 src; 1275 1276 if (rt_is_output_route(rt)) 1277 src = ip_hdr(skb)->saddr; 1278 else { 1279 struct fib_result res; 1280 struct iphdr *iph = ip_hdr(skb); 1281 struct flowi4 fl4 = { 1282 .daddr = iph->daddr, 1283 .saddr = iph->saddr, 1284 .flowi4_tos = RT_TOS(iph->tos), 1285 .flowi4_oif = rt->dst.dev->ifindex, 1286 .flowi4_iif = skb->dev->ifindex, 1287 .flowi4_mark = skb->mark, 1288 }; 1289 1290 rcu_read_lock(); 1291 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1292 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1293 else 1294 src = inet_select_addr(rt->dst.dev, 1295 rt_nexthop(rt, iph->daddr), 1296 RT_SCOPE_UNIVERSE); 1297 rcu_read_unlock(); 1298 } 1299 memcpy(addr, &src, 4); 1300 } 1301 1302 #ifdef CONFIG_IP_ROUTE_CLASSID 1303 static void set_class_tag(struct rtable *rt, u32 tag) 1304 { 1305 if (!(rt->dst.tclassid & 0xFFFF)) 1306 rt->dst.tclassid |= tag & 0xFFFF; 1307 if (!(rt->dst.tclassid & 0xFFFF0000)) 1308 rt->dst.tclassid |= tag & 0xFFFF0000; 1309 } 1310 #endif 1311 1312 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1313 { 1314 struct net *net = dev_net(dst->dev); 1315 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1316 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1317 net->ipv4.ip_rt_min_advmss); 1318 1319 return min(advmss, IPV4_MAX_PMTU - header_size); 1320 } 1321 1322 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1323 { 1324 return ip_dst_mtu_maybe_forward(dst, false); 1325 } 1326 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1327 1328 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1329 { 1330 struct fnhe_hash_bucket *hash; 1331 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1332 u32 hval = fnhe_hashfun(daddr); 1333 1334 spin_lock_bh(&fnhe_lock); 1335 1336 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1337 lockdep_is_held(&fnhe_lock)); 1338 hash += hval; 1339 1340 fnhe_p = &hash->chain; 1341 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1342 while (fnhe) { 1343 if (fnhe->fnhe_daddr == daddr) { 1344 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1345 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1346 /* set fnhe_daddr to 0 to ensure it won't bind with 1347 * new dsts in rt_bind_exception(). 1348 */ 1349 fnhe->fnhe_daddr = 0; 1350 fnhe_flush_routes(fnhe); 1351 kfree_rcu(fnhe, rcu); 1352 break; 1353 } 1354 fnhe_p = &fnhe->fnhe_next; 1355 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1356 lockdep_is_held(&fnhe_lock)); 1357 } 1358 1359 spin_unlock_bh(&fnhe_lock); 1360 } 1361 1362 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1363 __be32 daddr) 1364 { 1365 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1366 struct fib_nh_exception *fnhe; 1367 u32 hval; 1368 1369 if (!hash) 1370 return NULL; 1371 1372 hval = fnhe_hashfun(daddr); 1373 1374 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1375 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1376 if (fnhe->fnhe_daddr == daddr) { 1377 if (fnhe->fnhe_expires && 1378 time_after(jiffies, fnhe->fnhe_expires)) { 1379 ip_del_fnhe(nhc, daddr); 1380 break; 1381 } 1382 return fnhe; 1383 } 1384 } 1385 return NULL; 1386 } 1387 1388 /* MTU selection: 1389 * 1. mtu on route is locked - use it 1390 * 2. mtu from nexthop exception 1391 * 3. mtu from egress device 1392 */ 1393 1394 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1395 { 1396 struct fib_nh_common *nhc = res->nhc; 1397 struct net_device *dev = nhc->nhc_dev; 1398 struct fib_info *fi = res->fi; 1399 u32 mtu = 0; 1400 1401 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1402 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1403 mtu = fi->fib_mtu; 1404 1405 if (likely(!mtu)) { 1406 struct fib_nh_exception *fnhe; 1407 1408 fnhe = find_exception(nhc, daddr); 1409 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1410 mtu = fnhe->fnhe_pmtu; 1411 } 1412 1413 if (likely(!mtu)) 1414 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1415 1416 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1417 } 1418 1419 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1420 __be32 daddr, const bool do_cache) 1421 { 1422 bool ret = false; 1423 1424 spin_lock_bh(&fnhe_lock); 1425 1426 if (daddr == fnhe->fnhe_daddr) { 1427 struct rtable __rcu **porig; 1428 struct rtable *orig; 1429 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1430 1431 if (rt_is_input_route(rt)) 1432 porig = &fnhe->fnhe_rth_input; 1433 else 1434 porig = &fnhe->fnhe_rth_output; 1435 orig = rcu_dereference(*porig); 1436 1437 if (fnhe->fnhe_genid != genid) { 1438 fnhe->fnhe_genid = genid; 1439 fnhe->fnhe_gw = 0; 1440 fnhe->fnhe_pmtu = 0; 1441 fnhe->fnhe_expires = 0; 1442 fnhe->fnhe_mtu_locked = false; 1443 fnhe_flush_routes(fnhe); 1444 orig = NULL; 1445 } 1446 fill_route_from_fnhe(rt, fnhe); 1447 if (!rt->rt_gw4) { 1448 rt->rt_gw4 = daddr; 1449 rt->rt_gw_family = AF_INET; 1450 } 1451 1452 if (do_cache) { 1453 dst_hold(&rt->dst); 1454 rcu_assign_pointer(*porig, rt); 1455 if (orig) { 1456 dst_dev_put(&orig->dst); 1457 dst_release(&orig->dst); 1458 } 1459 ret = true; 1460 } 1461 1462 fnhe->fnhe_stamp = jiffies; 1463 } 1464 spin_unlock_bh(&fnhe_lock); 1465 1466 return ret; 1467 } 1468 1469 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1470 { 1471 struct rtable *orig, *prev, **p; 1472 bool ret = true; 1473 1474 if (rt_is_input_route(rt)) { 1475 p = (struct rtable **)&nhc->nhc_rth_input; 1476 } else { 1477 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1478 } 1479 orig = *p; 1480 1481 /* hold dst before doing cmpxchg() to avoid race condition 1482 * on this dst 1483 */ 1484 dst_hold(&rt->dst); 1485 prev = cmpxchg(p, orig, rt); 1486 if (prev == orig) { 1487 if (orig) { 1488 rt_add_uncached_list(orig); 1489 dst_release(&orig->dst); 1490 } 1491 } else { 1492 dst_release(&rt->dst); 1493 ret = false; 1494 } 1495 1496 return ret; 1497 } 1498 1499 struct uncached_list { 1500 spinlock_t lock; 1501 struct list_head head; 1502 struct list_head quarantine; 1503 }; 1504 1505 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1506 1507 void rt_add_uncached_list(struct rtable *rt) 1508 { 1509 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1510 1511 rt->rt_uncached_list = ul; 1512 1513 spin_lock_bh(&ul->lock); 1514 list_add_tail(&rt->rt_uncached, &ul->head); 1515 spin_unlock_bh(&ul->lock); 1516 } 1517 1518 void rt_del_uncached_list(struct rtable *rt) 1519 { 1520 if (!list_empty(&rt->rt_uncached)) { 1521 struct uncached_list *ul = rt->rt_uncached_list; 1522 1523 spin_lock_bh(&ul->lock); 1524 list_del_init(&rt->rt_uncached); 1525 spin_unlock_bh(&ul->lock); 1526 } 1527 } 1528 1529 static void ipv4_dst_destroy(struct dst_entry *dst) 1530 { 1531 struct rtable *rt = (struct rtable *)dst; 1532 1533 ip_dst_metrics_put(dst); 1534 rt_del_uncached_list(rt); 1535 } 1536 1537 void rt_flush_dev(struct net_device *dev) 1538 { 1539 struct rtable *rt, *safe; 1540 int cpu; 1541 1542 for_each_possible_cpu(cpu) { 1543 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1544 1545 if (list_empty(&ul->head)) 1546 continue; 1547 1548 spin_lock_bh(&ul->lock); 1549 list_for_each_entry_safe(rt, safe, &ul->head, rt_uncached) { 1550 if (rt->dst.dev != dev) 1551 continue; 1552 rt->dst.dev = blackhole_netdev; 1553 dev_replace_track(dev, blackhole_netdev, 1554 &rt->dst.dev_tracker, 1555 GFP_ATOMIC); 1556 list_move(&rt->rt_uncached, &ul->quarantine); 1557 } 1558 spin_unlock_bh(&ul->lock); 1559 } 1560 } 1561 1562 static bool rt_cache_valid(const struct rtable *rt) 1563 { 1564 return rt && 1565 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1566 !rt_is_expired(rt); 1567 } 1568 1569 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1570 const struct fib_result *res, 1571 struct fib_nh_exception *fnhe, 1572 struct fib_info *fi, u16 type, u32 itag, 1573 const bool do_cache) 1574 { 1575 bool cached = false; 1576 1577 if (fi) { 1578 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1579 1580 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1581 rt->rt_uses_gateway = 1; 1582 rt->rt_gw_family = nhc->nhc_gw_family; 1583 /* only INET and INET6 are supported */ 1584 if (likely(nhc->nhc_gw_family == AF_INET)) 1585 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1586 else 1587 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1588 } 1589 1590 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1591 1592 #ifdef CONFIG_IP_ROUTE_CLASSID 1593 if (nhc->nhc_family == AF_INET) { 1594 struct fib_nh *nh; 1595 1596 nh = container_of(nhc, struct fib_nh, nh_common); 1597 rt->dst.tclassid = nh->nh_tclassid; 1598 } 1599 #endif 1600 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1601 if (unlikely(fnhe)) 1602 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1603 else if (do_cache) 1604 cached = rt_cache_route(nhc, rt); 1605 if (unlikely(!cached)) { 1606 /* Routes we intend to cache in nexthop exception or 1607 * FIB nexthop have the DST_NOCACHE bit clear. 1608 * However, if we are unsuccessful at storing this 1609 * route into the cache we really need to set it. 1610 */ 1611 if (!rt->rt_gw4) { 1612 rt->rt_gw_family = AF_INET; 1613 rt->rt_gw4 = daddr; 1614 } 1615 rt_add_uncached_list(rt); 1616 } 1617 } else 1618 rt_add_uncached_list(rt); 1619 1620 #ifdef CONFIG_IP_ROUTE_CLASSID 1621 #ifdef CONFIG_IP_MULTIPLE_TABLES 1622 set_class_tag(rt, res->tclassid); 1623 #endif 1624 set_class_tag(rt, itag); 1625 #endif 1626 } 1627 1628 struct rtable *rt_dst_alloc(struct net_device *dev, 1629 unsigned int flags, u16 type, 1630 bool nopolicy, bool noxfrm) 1631 { 1632 struct rtable *rt; 1633 1634 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1635 (nopolicy ? DST_NOPOLICY : 0) | 1636 (noxfrm ? DST_NOXFRM : 0)); 1637 1638 if (rt) { 1639 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1640 rt->rt_flags = flags; 1641 rt->rt_type = type; 1642 rt->rt_is_input = 0; 1643 rt->rt_iif = 0; 1644 rt->rt_pmtu = 0; 1645 rt->rt_mtu_locked = 0; 1646 rt->rt_uses_gateway = 0; 1647 rt->rt_gw_family = 0; 1648 rt->rt_gw4 = 0; 1649 INIT_LIST_HEAD(&rt->rt_uncached); 1650 1651 rt->dst.output = ip_output; 1652 if (flags & RTCF_LOCAL) 1653 rt->dst.input = ip_local_deliver; 1654 } 1655 1656 return rt; 1657 } 1658 EXPORT_SYMBOL(rt_dst_alloc); 1659 1660 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1661 { 1662 struct rtable *new_rt; 1663 1664 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1665 rt->dst.flags); 1666 1667 if (new_rt) { 1668 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1669 new_rt->rt_flags = rt->rt_flags; 1670 new_rt->rt_type = rt->rt_type; 1671 new_rt->rt_is_input = rt->rt_is_input; 1672 new_rt->rt_iif = rt->rt_iif; 1673 new_rt->rt_pmtu = rt->rt_pmtu; 1674 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1675 new_rt->rt_gw_family = rt->rt_gw_family; 1676 if (rt->rt_gw_family == AF_INET) 1677 new_rt->rt_gw4 = rt->rt_gw4; 1678 else if (rt->rt_gw_family == AF_INET6) 1679 new_rt->rt_gw6 = rt->rt_gw6; 1680 INIT_LIST_HEAD(&new_rt->rt_uncached); 1681 1682 new_rt->dst.input = rt->dst.input; 1683 new_rt->dst.output = rt->dst.output; 1684 new_rt->dst.error = rt->dst.error; 1685 new_rt->dst.lastuse = jiffies; 1686 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1687 } 1688 return new_rt; 1689 } 1690 EXPORT_SYMBOL(rt_dst_clone); 1691 1692 /* called in rcu_read_lock() section */ 1693 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1694 u8 tos, struct net_device *dev, 1695 struct in_device *in_dev, u32 *itag) 1696 { 1697 int err; 1698 1699 /* Primary sanity checks. */ 1700 if (!in_dev) 1701 return -EINVAL; 1702 1703 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1704 skb->protocol != htons(ETH_P_IP)) 1705 return -EINVAL; 1706 1707 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1708 return -EINVAL; 1709 1710 if (ipv4_is_zeronet(saddr)) { 1711 if (!ipv4_is_local_multicast(daddr) && 1712 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1713 return -EINVAL; 1714 } else { 1715 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1716 in_dev, itag); 1717 if (err < 0) 1718 return err; 1719 } 1720 return 0; 1721 } 1722 1723 /* called in rcu_read_lock() section */ 1724 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1725 u8 tos, struct net_device *dev, int our) 1726 { 1727 struct in_device *in_dev = __in_dev_get_rcu(dev); 1728 unsigned int flags = RTCF_MULTICAST; 1729 struct rtable *rth; 1730 u32 itag = 0; 1731 int err; 1732 1733 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1734 if (err) 1735 return err; 1736 1737 if (our) 1738 flags |= RTCF_LOCAL; 1739 1740 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1741 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 1742 if (!rth) 1743 return -ENOBUFS; 1744 1745 #ifdef CONFIG_IP_ROUTE_CLASSID 1746 rth->dst.tclassid = itag; 1747 #endif 1748 rth->dst.output = ip_rt_bug; 1749 rth->rt_is_input= 1; 1750 1751 #ifdef CONFIG_IP_MROUTE 1752 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1753 rth->dst.input = ip_mr_input; 1754 #endif 1755 RT_CACHE_STAT_INC(in_slow_mc); 1756 1757 skb_dst_set(skb, &rth->dst); 1758 return 0; 1759 } 1760 1761 1762 static void ip_handle_martian_source(struct net_device *dev, 1763 struct in_device *in_dev, 1764 struct sk_buff *skb, 1765 __be32 daddr, 1766 __be32 saddr) 1767 { 1768 RT_CACHE_STAT_INC(in_martian_src); 1769 #ifdef CONFIG_IP_ROUTE_VERBOSE 1770 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1771 /* 1772 * RFC1812 recommendation, if source is martian, 1773 * the only hint is MAC header. 1774 */ 1775 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1776 &daddr, &saddr, dev->name); 1777 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1778 print_hex_dump(KERN_WARNING, "ll header: ", 1779 DUMP_PREFIX_OFFSET, 16, 1, 1780 skb_mac_header(skb), 1781 dev->hard_header_len, false); 1782 } 1783 } 1784 #endif 1785 } 1786 1787 /* called in rcu_read_lock() section */ 1788 static int __mkroute_input(struct sk_buff *skb, 1789 const struct fib_result *res, 1790 struct in_device *in_dev, 1791 __be32 daddr, __be32 saddr, u32 tos) 1792 { 1793 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1794 struct net_device *dev = nhc->nhc_dev; 1795 struct fib_nh_exception *fnhe; 1796 struct rtable *rth; 1797 int err; 1798 struct in_device *out_dev; 1799 bool do_cache; 1800 u32 itag = 0; 1801 1802 /* get a working reference to the output device */ 1803 out_dev = __in_dev_get_rcu(dev); 1804 if (!out_dev) { 1805 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1806 return -EINVAL; 1807 } 1808 1809 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1810 in_dev->dev, in_dev, &itag); 1811 if (err < 0) { 1812 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1813 saddr); 1814 1815 goto cleanup; 1816 } 1817 1818 do_cache = res->fi && !itag; 1819 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1820 skb->protocol == htons(ETH_P_IP)) { 1821 __be32 gw; 1822 1823 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1824 if (IN_DEV_SHARED_MEDIA(out_dev) || 1825 inet_addr_onlink(out_dev, saddr, gw)) 1826 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1827 } 1828 1829 if (skb->protocol != htons(ETH_P_IP)) { 1830 /* Not IP (i.e. ARP). Do not create route, if it is 1831 * invalid for proxy arp. DNAT routes are always valid. 1832 * 1833 * Proxy arp feature have been extended to allow, ARP 1834 * replies back to the same interface, to support 1835 * Private VLAN switch technologies. See arp.c. 1836 */ 1837 if (out_dev == in_dev && 1838 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1839 err = -EINVAL; 1840 goto cleanup; 1841 } 1842 } 1843 1844 fnhe = find_exception(nhc, daddr); 1845 if (do_cache) { 1846 if (fnhe) 1847 rth = rcu_dereference(fnhe->fnhe_rth_input); 1848 else 1849 rth = rcu_dereference(nhc->nhc_rth_input); 1850 if (rt_cache_valid(rth)) { 1851 skb_dst_set_noref(skb, &rth->dst); 1852 goto out; 1853 } 1854 } 1855 1856 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1857 IN_DEV_ORCONF(in_dev, NOPOLICY), 1858 IN_DEV_ORCONF(out_dev, NOXFRM)); 1859 if (!rth) { 1860 err = -ENOBUFS; 1861 goto cleanup; 1862 } 1863 1864 rth->rt_is_input = 1; 1865 RT_CACHE_STAT_INC(in_slow_tot); 1866 1867 rth->dst.input = ip_forward; 1868 1869 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1870 do_cache); 1871 lwtunnel_set_redirect(&rth->dst); 1872 skb_dst_set(skb, &rth->dst); 1873 out: 1874 err = 0; 1875 cleanup: 1876 return err; 1877 } 1878 1879 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1880 /* To make ICMP packets follow the right flow, the multipath hash is 1881 * calculated from the inner IP addresses. 1882 */ 1883 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1884 struct flow_keys *hash_keys) 1885 { 1886 const struct iphdr *outer_iph = ip_hdr(skb); 1887 const struct iphdr *key_iph = outer_iph; 1888 const struct iphdr *inner_iph; 1889 const struct icmphdr *icmph; 1890 struct iphdr _inner_iph; 1891 struct icmphdr _icmph; 1892 1893 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1894 goto out; 1895 1896 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1897 goto out; 1898 1899 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1900 &_icmph); 1901 if (!icmph) 1902 goto out; 1903 1904 if (!icmp_is_err(icmph->type)) 1905 goto out; 1906 1907 inner_iph = skb_header_pointer(skb, 1908 outer_iph->ihl * 4 + sizeof(_icmph), 1909 sizeof(_inner_iph), &_inner_iph); 1910 if (!inner_iph) 1911 goto out; 1912 1913 key_iph = inner_iph; 1914 out: 1915 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1916 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1917 } 1918 1919 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1920 const struct sk_buff *skb, 1921 bool *p_has_inner) 1922 { 1923 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1924 struct flow_keys keys, hash_keys; 1925 1926 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1927 return 0; 1928 1929 memset(&hash_keys, 0, sizeof(hash_keys)); 1930 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1931 1932 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1933 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1934 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1935 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1936 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1937 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1938 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1939 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1940 hash_keys.ports.src = keys.ports.src; 1941 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1942 hash_keys.ports.dst = keys.ports.dst; 1943 1944 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1945 return flow_hash_from_keys(&hash_keys); 1946 } 1947 1948 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1949 const struct sk_buff *skb, 1950 bool has_inner) 1951 { 1952 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1953 struct flow_keys keys, hash_keys; 1954 1955 /* We assume the packet carries an encapsulation, but if none was 1956 * encountered during dissection of the outer flow, then there is no 1957 * point in calling the flow dissector again. 1958 */ 1959 if (!has_inner) 1960 return 0; 1961 1962 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1963 return 0; 1964 1965 memset(&hash_keys, 0, sizeof(hash_keys)); 1966 skb_flow_dissect_flow_keys(skb, &keys, 0); 1967 1968 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1969 return 0; 1970 1971 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1972 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1973 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1974 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1975 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1976 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1977 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1978 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1979 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1980 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1981 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1982 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1983 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1984 hash_keys.tags.flow_label = keys.tags.flow_label; 1985 } 1986 1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1988 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1989 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1990 hash_keys.ports.src = keys.ports.src; 1991 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1992 hash_keys.ports.dst = keys.ports.dst; 1993 1994 return flow_hash_from_keys(&hash_keys); 1995 } 1996 1997 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1998 const struct sk_buff *skb) 1999 { 2000 u32 mhash, mhash_inner; 2001 bool has_inner = true; 2002 2003 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2004 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2005 2006 return jhash_2words(mhash, mhash_inner, 0); 2007 } 2008 2009 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2010 const struct flowi4 *fl4) 2011 { 2012 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 2013 struct flow_keys hash_keys; 2014 2015 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2016 return 0; 2017 2018 memset(&hash_keys, 0, sizeof(hash_keys)); 2019 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2020 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2021 hash_keys.addrs.v4addrs.src = fl4->saddr; 2022 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2023 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2024 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2025 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2026 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2027 hash_keys.ports.src = fl4->fl4_sport; 2028 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2029 hash_keys.ports.dst = fl4->fl4_dport; 2030 2031 return flow_hash_from_keys(&hash_keys); 2032 } 2033 2034 /* if skb is set it will be used and fl4 can be NULL */ 2035 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2036 const struct sk_buff *skb, struct flow_keys *flkeys) 2037 { 2038 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2039 struct flow_keys hash_keys; 2040 u32 mhash = 0; 2041 2042 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2043 case 0: 2044 memset(&hash_keys, 0, sizeof(hash_keys)); 2045 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2046 if (skb) { 2047 ip_multipath_l3_keys(skb, &hash_keys); 2048 } else { 2049 hash_keys.addrs.v4addrs.src = fl4->saddr; 2050 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2051 } 2052 mhash = flow_hash_from_keys(&hash_keys); 2053 break; 2054 case 1: 2055 /* skb is currently provided only when forwarding */ 2056 if (skb) { 2057 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2058 struct flow_keys keys; 2059 2060 /* short-circuit if we already have L4 hash present */ 2061 if (skb->l4_hash) 2062 return skb_get_hash_raw(skb) >> 1; 2063 2064 memset(&hash_keys, 0, sizeof(hash_keys)); 2065 2066 if (!flkeys) { 2067 skb_flow_dissect_flow_keys(skb, &keys, flag); 2068 flkeys = &keys; 2069 } 2070 2071 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2072 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2073 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2074 hash_keys.ports.src = flkeys->ports.src; 2075 hash_keys.ports.dst = flkeys->ports.dst; 2076 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2077 } else { 2078 memset(&hash_keys, 0, sizeof(hash_keys)); 2079 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2080 hash_keys.addrs.v4addrs.src = fl4->saddr; 2081 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2082 hash_keys.ports.src = fl4->fl4_sport; 2083 hash_keys.ports.dst = fl4->fl4_dport; 2084 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2085 } 2086 mhash = flow_hash_from_keys(&hash_keys); 2087 break; 2088 case 2: 2089 memset(&hash_keys, 0, sizeof(hash_keys)); 2090 /* skb is currently provided only when forwarding */ 2091 if (skb) { 2092 struct flow_keys keys; 2093 2094 skb_flow_dissect_flow_keys(skb, &keys, 0); 2095 /* Inner can be v4 or v6 */ 2096 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2097 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2098 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2099 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2100 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2101 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2102 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2103 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2104 hash_keys.tags.flow_label = keys.tags.flow_label; 2105 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2106 } else { 2107 /* Same as case 0 */ 2108 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2109 ip_multipath_l3_keys(skb, &hash_keys); 2110 } 2111 } else { 2112 /* Same as case 0 */ 2113 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2114 hash_keys.addrs.v4addrs.src = fl4->saddr; 2115 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2116 } 2117 mhash = flow_hash_from_keys(&hash_keys); 2118 break; 2119 case 3: 2120 if (skb) 2121 mhash = fib_multipath_custom_hash_skb(net, skb); 2122 else 2123 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2124 break; 2125 } 2126 2127 if (multipath_hash) 2128 mhash = jhash_2words(mhash, multipath_hash, 0); 2129 2130 return mhash >> 1; 2131 } 2132 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2133 2134 static int ip_mkroute_input(struct sk_buff *skb, 2135 struct fib_result *res, 2136 struct in_device *in_dev, 2137 __be32 daddr, __be32 saddr, u32 tos, 2138 struct flow_keys *hkeys) 2139 { 2140 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2141 if (res->fi && fib_info_num_path(res->fi) > 1) { 2142 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2143 2144 fib_select_multipath(res, h); 2145 } 2146 #endif 2147 2148 /* create a routing cache entry */ 2149 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2150 } 2151 2152 /* Implements all the saddr-related checks as ip_route_input_slow(), 2153 * assuming daddr is valid and the destination is not a local broadcast one. 2154 * Uses the provided hint instead of performing a route lookup. 2155 */ 2156 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2157 u8 tos, struct net_device *dev, 2158 const struct sk_buff *hint) 2159 { 2160 struct in_device *in_dev = __in_dev_get_rcu(dev); 2161 struct rtable *rt = skb_rtable(hint); 2162 struct net *net = dev_net(dev); 2163 int err = -EINVAL; 2164 u32 tag = 0; 2165 2166 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2167 goto martian_source; 2168 2169 if (ipv4_is_zeronet(saddr)) 2170 goto martian_source; 2171 2172 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2173 goto martian_source; 2174 2175 if (rt->rt_type != RTN_LOCAL) 2176 goto skip_validate_source; 2177 2178 tos &= IPTOS_RT_MASK; 2179 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2180 if (err < 0) 2181 goto martian_source; 2182 2183 skip_validate_source: 2184 skb_dst_copy(skb, hint); 2185 return 0; 2186 2187 martian_source: 2188 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2189 return err; 2190 } 2191 2192 /* get device for dst_alloc with local routes */ 2193 static struct net_device *ip_rt_get_dev(struct net *net, 2194 const struct fib_result *res) 2195 { 2196 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2197 struct net_device *dev = NULL; 2198 2199 if (nhc) 2200 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2201 2202 return dev ? : net->loopback_dev; 2203 } 2204 2205 /* 2206 * NOTE. We drop all the packets that has local source 2207 * addresses, because every properly looped back packet 2208 * must have correct destination already attached by output routine. 2209 * Changes in the enforced policies must be applied also to 2210 * ip_route_use_hint(). 2211 * 2212 * Such approach solves two big problems: 2213 * 1. Not simplex devices are handled properly. 2214 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2215 * called with rcu_read_lock() 2216 */ 2217 2218 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2219 u8 tos, struct net_device *dev, 2220 struct fib_result *res) 2221 { 2222 struct in_device *in_dev = __in_dev_get_rcu(dev); 2223 struct flow_keys *flkeys = NULL, _flkeys; 2224 struct net *net = dev_net(dev); 2225 struct ip_tunnel_info *tun_info; 2226 int err = -EINVAL; 2227 unsigned int flags = 0; 2228 u32 itag = 0; 2229 struct rtable *rth; 2230 struct flowi4 fl4; 2231 bool do_cache = true; 2232 2233 /* IP on this device is disabled. */ 2234 2235 if (!in_dev) 2236 goto out; 2237 2238 /* Check for the most weird martians, which can be not detected 2239 * by fib_lookup. 2240 */ 2241 2242 tun_info = skb_tunnel_info(skb); 2243 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2244 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2245 else 2246 fl4.flowi4_tun_key.tun_id = 0; 2247 skb_dst_drop(skb); 2248 2249 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2250 goto martian_source; 2251 2252 res->fi = NULL; 2253 res->table = NULL; 2254 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2255 goto brd_input; 2256 2257 /* Accept zero addresses only to limited broadcast; 2258 * I even do not know to fix it or not. Waiting for complains :-) 2259 */ 2260 if (ipv4_is_zeronet(saddr)) 2261 goto martian_source; 2262 2263 if (ipv4_is_zeronet(daddr)) 2264 goto martian_destination; 2265 2266 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2267 * and call it once if daddr or/and saddr are loopback addresses 2268 */ 2269 if (ipv4_is_loopback(daddr)) { 2270 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2271 goto martian_destination; 2272 } else if (ipv4_is_loopback(saddr)) { 2273 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2274 goto martian_source; 2275 } 2276 2277 /* 2278 * Now we are ready to route packet. 2279 */ 2280 fl4.flowi4_l3mdev = 0; 2281 fl4.flowi4_oif = 0; 2282 fl4.flowi4_iif = dev->ifindex; 2283 fl4.flowi4_mark = skb->mark; 2284 fl4.flowi4_tos = tos; 2285 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2286 fl4.flowi4_flags = 0; 2287 fl4.daddr = daddr; 2288 fl4.saddr = saddr; 2289 fl4.flowi4_uid = sock_net_uid(net, NULL); 2290 fl4.flowi4_multipath_hash = 0; 2291 2292 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2293 flkeys = &_flkeys; 2294 } else { 2295 fl4.flowi4_proto = 0; 2296 fl4.fl4_sport = 0; 2297 fl4.fl4_dport = 0; 2298 } 2299 2300 err = fib_lookup(net, &fl4, res, 0); 2301 if (err != 0) { 2302 if (!IN_DEV_FORWARD(in_dev)) 2303 err = -EHOSTUNREACH; 2304 goto no_route; 2305 } 2306 2307 if (res->type == RTN_BROADCAST) { 2308 if (IN_DEV_BFORWARD(in_dev)) 2309 goto make_route; 2310 /* not do cache if bc_forwarding is enabled */ 2311 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2312 do_cache = false; 2313 goto brd_input; 2314 } 2315 2316 if (res->type == RTN_LOCAL) { 2317 err = fib_validate_source(skb, saddr, daddr, tos, 2318 0, dev, in_dev, &itag); 2319 if (err < 0) 2320 goto martian_source; 2321 goto local_input; 2322 } 2323 2324 if (!IN_DEV_FORWARD(in_dev)) { 2325 err = -EHOSTUNREACH; 2326 goto no_route; 2327 } 2328 if (res->type != RTN_UNICAST) 2329 goto martian_destination; 2330 2331 make_route: 2332 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2333 out: return err; 2334 2335 brd_input: 2336 if (skb->protocol != htons(ETH_P_IP)) 2337 goto e_inval; 2338 2339 if (!ipv4_is_zeronet(saddr)) { 2340 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2341 in_dev, &itag); 2342 if (err < 0) 2343 goto martian_source; 2344 } 2345 flags |= RTCF_BROADCAST; 2346 res->type = RTN_BROADCAST; 2347 RT_CACHE_STAT_INC(in_brd); 2348 2349 local_input: 2350 do_cache &= res->fi && !itag; 2351 if (do_cache) { 2352 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2353 2354 rth = rcu_dereference(nhc->nhc_rth_input); 2355 if (rt_cache_valid(rth)) { 2356 skb_dst_set_noref(skb, &rth->dst); 2357 err = 0; 2358 goto out; 2359 } 2360 } 2361 2362 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2363 flags | RTCF_LOCAL, res->type, 2364 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 2365 if (!rth) 2366 goto e_nobufs; 2367 2368 rth->dst.output= ip_rt_bug; 2369 #ifdef CONFIG_IP_ROUTE_CLASSID 2370 rth->dst.tclassid = itag; 2371 #endif 2372 rth->rt_is_input = 1; 2373 2374 RT_CACHE_STAT_INC(in_slow_tot); 2375 if (res->type == RTN_UNREACHABLE) { 2376 rth->dst.input= ip_error; 2377 rth->dst.error= -err; 2378 rth->rt_flags &= ~RTCF_LOCAL; 2379 } 2380 2381 if (do_cache) { 2382 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2383 2384 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2385 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2386 WARN_ON(rth->dst.input == lwtunnel_input); 2387 rth->dst.lwtstate->orig_input = rth->dst.input; 2388 rth->dst.input = lwtunnel_input; 2389 } 2390 2391 if (unlikely(!rt_cache_route(nhc, rth))) 2392 rt_add_uncached_list(rth); 2393 } 2394 skb_dst_set(skb, &rth->dst); 2395 err = 0; 2396 goto out; 2397 2398 no_route: 2399 RT_CACHE_STAT_INC(in_no_route); 2400 res->type = RTN_UNREACHABLE; 2401 res->fi = NULL; 2402 res->table = NULL; 2403 goto local_input; 2404 2405 /* 2406 * Do not cache martian addresses: they should be logged (RFC1812) 2407 */ 2408 martian_destination: 2409 RT_CACHE_STAT_INC(in_martian_dst); 2410 #ifdef CONFIG_IP_ROUTE_VERBOSE 2411 if (IN_DEV_LOG_MARTIANS(in_dev)) 2412 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2413 &daddr, &saddr, dev->name); 2414 #endif 2415 2416 e_inval: 2417 err = -EINVAL; 2418 goto out; 2419 2420 e_nobufs: 2421 err = -ENOBUFS; 2422 goto out; 2423 2424 martian_source: 2425 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2426 goto out; 2427 } 2428 2429 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2430 u8 tos, struct net_device *dev) 2431 { 2432 struct fib_result res; 2433 int err; 2434 2435 tos &= IPTOS_RT_MASK; 2436 rcu_read_lock(); 2437 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2438 rcu_read_unlock(); 2439 2440 return err; 2441 } 2442 EXPORT_SYMBOL(ip_route_input_noref); 2443 2444 /* called with rcu_read_lock held */ 2445 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2446 u8 tos, struct net_device *dev, struct fib_result *res) 2447 { 2448 /* Multicast recognition logic is moved from route cache to here. 2449 * The problem was that too many Ethernet cards have broken/missing 2450 * hardware multicast filters :-( As result the host on multicasting 2451 * network acquires a lot of useless route cache entries, sort of 2452 * SDR messages from all the world. Now we try to get rid of them. 2453 * Really, provided software IP multicast filter is organized 2454 * reasonably (at least, hashed), it does not result in a slowdown 2455 * comparing with route cache reject entries. 2456 * Note, that multicast routers are not affected, because 2457 * route cache entry is created eventually. 2458 */ 2459 if (ipv4_is_multicast(daddr)) { 2460 struct in_device *in_dev = __in_dev_get_rcu(dev); 2461 int our = 0; 2462 int err = -EINVAL; 2463 2464 if (!in_dev) 2465 return err; 2466 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2467 ip_hdr(skb)->protocol); 2468 2469 /* check l3 master if no match yet */ 2470 if (!our && netif_is_l3_slave(dev)) { 2471 struct in_device *l3_in_dev; 2472 2473 l3_in_dev = __in_dev_get_rcu(skb->dev); 2474 if (l3_in_dev) 2475 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2476 ip_hdr(skb)->protocol); 2477 } 2478 2479 if (our 2480 #ifdef CONFIG_IP_MROUTE 2481 || 2482 (!ipv4_is_local_multicast(daddr) && 2483 IN_DEV_MFORWARD(in_dev)) 2484 #endif 2485 ) { 2486 err = ip_route_input_mc(skb, daddr, saddr, 2487 tos, dev, our); 2488 } 2489 return err; 2490 } 2491 2492 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2493 } 2494 2495 /* called with rcu_read_lock() */ 2496 static struct rtable *__mkroute_output(const struct fib_result *res, 2497 const struct flowi4 *fl4, int orig_oif, 2498 struct net_device *dev_out, 2499 unsigned int flags) 2500 { 2501 struct fib_info *fi = res->fi; 2502 struct fib_nh_exception *fnhe; 2503 struct in_device *in_dev; 2504 u16 type = res->type; 2505 struct rtable *rth; 2506 bool do_cache; 2507 2508 in_dev = __in_dev_get_rcu(dev_out); 2509 if (!in_dev) 2510 return ERR_PTR(-EINVAL); 2511 2512 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2513 if (ipv4_is_loopback(fl4->saddr) && 2514 !(dev_out->flags & IFF_LOOPBACK) && 2515 !netif_is_l3_master(dev_out)) 2516 return ERR_PTR(-EINVAL); 2517 2518 if (ipv4_is_lbcast(fl4->daddr)) 2519 type = RTN_BROADCAST; 2520 else if (ipv4_is_multicast(fl4->daddr)) 2521 type = RTN_MULTICAST; 2522 else if (ipv4_is_zeronet(fl4->daddr)) 2523 return ERR_PTR(-EINVAL); 2524 2525 if (dev_out->flags & IFF_LOOPBACK) 2526 flags |= RTCF_LOCAL; 2527 2528 do_cache = true; 2529 if (type == RTN_BROADCAST) { 2530 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2531 fi = NULL; 2532 } else if (type == RTN_MULTICAST) { 2533 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2534 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2535 fl4->flowi4_proto)) 2536 flags &= ~RTCF_LOCAL; 2537 else 2538 do_cache = false; 2539 /* If multicast route do not exist use 2540 * default one, but do not gateway in this case. 2541 * Yes, it is hack. 2542 */ 2543 if (fi && res->prefixlen < 4) 2544 fi = NULL; 2545 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2546 (orig_oif != dev_out->ifindex)) { 2547 /* For local routes that require a particular output interface 2548 * we do not want to cache the result. Caching the result 2549 * causes incorrect behaviour when there are multiple source 2550 * addresses on the interface, the end result being that if the 2551 * intended recipient is waiting on that interface for the 2552 * packet he won't receive it because it will be delivered on 2553 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2554 * be set to the loopback interface as well. 2555 */ 2556 do_cache = false; 2557 } 2558 2559 fnhe = NULL; 2560 do_cache &= fi != NULL; 2561 if (fi) { 2562 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2563 struct rtable __rcu **prth; 2564 2565 fnhe = find_exception(nhc, fl4->daddr); 2566 if (!do_cache) 2567 goto add; 2568 if (fnhe) { 2569 prth = &fnhe->fnhe_rth_output; 2570 } else { 2571 if (unlikely(fl4->flowi4_flags & 2572 FLOWI_FLAG_KNOWN_NH && 2573 !(nhc->nhc_gw_family && 2574 nhc->nhc_scope == RT_SCOPE_LINK))) { 2575 do_cache = false; 2576 goto add; 2577 } 2578 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2579 } 2580 rth = rcu_dereference(*prth); 2581 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2582 return rth; 2583 } 2584 2585 add: 2586 rth = rt_dst_alloc(dev_out, flags, type, 2587 IN_DEV_ORCONF(in_dev, NOPOLICY), 2588 IN_DEV_ORCONF(in_dev, NOXFRM)); 2589 if (!rth) 2590 return ERR_PTR(-ENOBUFS); 2591 2592 rth->rt_iif = orig_oif; 2593 2594 RT_CACHE_STAT_INC(out_slow_tot); 2595 2596 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2597 if (flags & RTCF_LOCAL && 2598 !(dev_out->flags & IFF_LOOPBACK)) { 2599 rth->dst.output = ip_mc_output; 2600 RT_CACHE_STAT_INC(out_slow_mc); 2601 } 2602 #ifdef CONFIG_IP_MROUTE 2603 if (type == RTN_MULTICAST) { 2604 if (IN_DEV_MFORWARD(in_dev) && 2605 !ipv4_is_local_multicast(fl4->daddr)) { 2606 rth->dst.input = ip_mr_input; 2607 rth->dst.output = ip_mc_output; 2608 } 2609 } 2610 #endif 2611 } 2612 2613 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2614 lwtunnel_set_redirect(&rth->dst); 2615 2616 return rth; 2617 } 2618 2619 /* 2620 * Major route resolver routine. 2621 */ 2622 2623 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2624 const struct sk_buff *skb) 2625 { 2626 struct fib_result res = { 2627 .type = RTN_UNSPEC, 2628 .fi = NULL, 2629 .table = NULL, 2630 .tclassid = 0, 2631 }; 2632 struct rtable *rth; 2633 2634 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2635 ip_rt_fix_tos(fl4); 2636 2637 rcu_read_lock(); 2638 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2639 rcu_read_unlock(); 2640 2641 return rth; 2642 } 2643 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2644 2645 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2646 struct fib_result *res, 2647 const struct sk_buff *skb) 2648 { 2649 struct net_device *dev_out = NULL; 2650 int orig_oif = fl4->flowi4_oif; 2651 unsigned int flags = 0; 2652 struct rtable *rth; 2653 int err; 2654 2655 if (fl4->saddr) { 2656 if (ipv4_is_multicast(fl4->saddr) || 2657 ipv4_is_lbcast(fl4->saddr) || 2658 ipv4_is_zeronet(fl4->saddr)) { 2659 rth = ERR_PTR(-EINVAL); 2660 goto out; 2661 } 2662 2663 rth = ERR_PTR(-ENETUNREACH); 2664 2665 /* I removed check for oif == dev_out->oif here. 2666 * It was wrong for two reasons: 2667 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2668 * is assigned to multiple interfaces. 2669 * 2. Moreover, we are allowed to send packets with saddr 2670 * of another iface. --ANK 2671 */ 2672 2673 if (fl4->flowi4_oif == 0 && 2674 (ipv4_is_multicast(fl4->daddr) || 2675 ipv4_is_lbcast(fl4->daddr))) { 2676 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2677 dev_out = __ip_dev_find(net, fl4->saddr, false); 2678 if (!dev_out) 2679 goto out; 2680 2681 /* Special hack: user can direct multicasts 2682 * and limited broadcast via necessary interface 2683 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2684 * This hack is not just for fun, it allows 2685 * vic,vat and friends to work. 2686 * They bind socket to loopback, set ttl to zero 2687 * and expect that it will work. 2688 * From the viewpoint of routing cache they are broken, 2689 * because we are not allowed to build multicast path 2690 * with loopback source addr (look, routing cache 2691 * cannot know, that ttl is zero, so that packet 2692 * will not leave this host and route is valid). 2693 * Luckily, this hack is good workaround. 2694 */ 2695 2696 fl4->flowi4_oif = dev_out->ifindex; 2697 goto make_route; 2698 } 2699 2700 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2701 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2702 if (!__ip_dev_find(net, fl4->saddr, false)) 2703 goto out; 2704 } 2705 } 2706 2707 2708 if (fl4->flowi4_oif) { 2709 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2710 rth = ERR_PTR(-ENODEV); 2711 if (!dev_out) 2712 goto out; 2713 2714 /* RACE: Check return value of inet_select_addr instead. */ 2715 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2716 rth = ERR_PTR(-ENETUNREACH); 2717 goto out; 2718 } 2719 if (ipv4_is_local_multicast(fl4->daddr) || 2720 ipv4_is_lbcast(fl4->daddr) || 2721 fl4->flowi4_proto == IPPROTO_IGMP) { 2722 if (!fl4->saddr) 2723 fl4->saddr = inet_select_addr(dev_out, 0, 2724 RT_SCOPE_LINK); 2725 goto make_route; 2726 } 2727 if (!fl4->saddr) { 2728 if (ipv4_is_multicast(fl4->daddr)) 2729 fl4->saddr = inet_select_addr(dev_out, 0, 2730 fl4->flowi4_scope); 2731 else if (!fl4->daddr) 2732 fl4->saddr = inet_select_addr(dev_out, 0, 2733 RT_SCOPE_HOST); 2734 } 2735 } 2736 2737 if (!fl4->daddr) { 2738 fl4->daddr = fl4->saddr; 2739 if (!fl4->daddr) 2740 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2741 dev_out = net->loopback_dev; 2742 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2743 res->type = RTN_LOCAL; 2744 flags |= RTCF_LOCAL; 2745 goto make_route; 2746 } 2747 2748 err = fib_lookup(net, fl4, res, 0); 2749 if (err) { 2750 res->fi = NULL; 2751 res->table = NULL; 2752 if (fl4->flowi4_oif && 2753 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2754 /* Apparently, routing tables are wrong. Assume, 2755 * that the destination is on link. 2756 * 2757 * WHY? DW. 2758 * Because we are allowed to send to iface 2759 * even if it has NO routes and NO assigned 2760 * addresses. When oif is specified, routing 2761 * tables are looked up with only one purpose: 2762 * to catch if destination is gatewayed, rather than 2763 * direct. Moreover, if MSG_DONTROUTE is set, 2764 * we send packet, ignoring both routing tables 2765 * and ifaddr state. --ANK 2766 * 2767 * 2768 * We could make it even if oif is unknown, 2769 * likely IPv6, but we do not. 2770 */ 2771 2772 if (fl4->saddr == 0) 2773 fl4->saddr = inet_select_addr(dev_out, 0, 2774 RT_SCOPE_LINK); 2775 res->type = RTN_UNICAST; 2776 goto make_route; 2777 } 2778 rth = ERR_PTR(err); 2779 goto out; 2780 } 2781 2782 if (res->type == RTN_LOCAL) { 2783 if (!fl4->saddr) { 2784 if (res->fi->fib_prefsrc) 2785 fl4->saddr = res->fi->fib_prefsrc; 2786 else 2787 fl4->saddr = fl4->daddr; 2788 } 2789 2790 /* L3 master device is the loopback for that domain */ 2791 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2792 net->loopback_dev; 2793 2794 /* make sure orig_oif points to fib result device even 2795 * though packet rx/tx happens over loopback or l3mdev 2796 */ 2797 orig_oif = FIB_RES_OIF(*res); 2798 2799 fl4->flowi4_oif = dev_out->ifindex; 2800 flags |= RTCF_LOCAL; 2801 goto make_route; 2802 } 2803 2804 fib_select_path(net, res, fl4, skb); 2805 2806 dev_out = FIB_RES_DEV(*res); 2807 2808 make_route: 2809 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2810 2811 out: 2812 return rth; 2813 } 2814 2815 static struct dst_ops ipv4_dst_blackhole_ops = { 2816 .family = AF_INET, 2817 .default_advmss = ipv4_default_advmss, 2818 .neigh_lookup = ipv4_neigh_lookup, 2819 .check = dst_blackhole_check, 2820 .cow_metrics = dst_blackhole_cow_metrics, 2821 .update_pmtu = dst_blackhole_update_pmtu, 2822 .redirect = dst_blackhole_redirect, 2823 .mtu = dst_blackhole_mtu, 2824 }; 2825 2826 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2827 { 2828 struct rtable *ort = (struct rtable *) dst_orig; 2829 struct rtable *rt; 2830 2831 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2832 if (rt) { 2833 struct dst_entry *new = &rt->dst; 2834 2835 new->__use = 1; 2836 new->input = dst_discard; 2837 new->output = dst_discard_out; 2838 2839 new->dev = net->loopback_dev; 2840 dev_hold_track(new->dev, &new->dev_tracker, GFP_ATOMIC); 2841 2842 rt->rt_is_input = ort->rt_is_input; 2843 rt->rt_iif = ort->rt_iif; 2844 rt->rt_pmtu = ort->rt_pmtu; 2845 rt->rt_mtu_locked = ort->rt_mtu_locked; 2846 2847 rt->rt_genid = rt_genid_ipv4(net); 2848 rt->rt_flags = ort->rt_flags; 2849 rt->rt_type = ort->rt_type; 2850 rt->rt_uses_gateway = ort->rt_uses_gateway; 2851 rt->rt_gw_family = ort->rt_gw_family; 2852 if (rt->rt_gw_family == AF_INET) 2853 rt->rt_gw4 = ort->rt_gw4; 2854 else if (rt->rt_gw_family == AF_INET6) 2855 rt->rt_gw6 = ort->rt_gw6; 2856 2857 INIT_LIST_HEAD(&rt->rt_uncached); 2858 } 2859 2860 dst_release(dst_orig); 2861 2862 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2863 } 2864 2865 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2866 const struct sock *sk) 2867 { 2868 struct rtable *rt = __ip_route_output_key(net, flp4); 2869 2870 if (IS_ERR(rt)) 2871 return rt; 2872 2873 if (flp4->flowi4_proto) { 2874 flp4->flowi4_oif = rt->dst.dev->ifindex; 2875 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2876 flowi4_to_flowi(flp4), 2877 sk, 0); 2878 } 2879 2880 return rt; 2881 } 2882 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2883 2884 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2885 struct net_device *dev, 2886 struct net *net, __be32 *saddr, 2887 const struct ip_tunnel_info *info, 2888 u8 protocol, bool use_cache) 2889 { 2890 #ifdef CONFIG_DST_CACHE 2891 struct dst_cache *dst_cache; 2892 #endif 2893 struct rtable *rt = NULL; 2894 struct flowi4 fl4; 2895 __u8 tos; 2896 2897 #ifdef CONFIG_DST_CACHE 2898 dst_cache = (struct dst_cache *)&info->dst_cache; 2899 if (use_cache) { 2900 rt = dst_cache_get_ip4(dst_cache, saddr); 2901 if (rt) 2902 return rt; 2903 } 2904 #endif 2905 memset(&fl4, 0, sizeof(fl4)); 2906 fl4.flowi4_mark = skb->mark; 2907 fl4.flowi4_proto = protocol; 2908 fl4.daddr = info->key.u.ipv4.dst; 2909 fl4.saddr = info->key.u.ipv4.src; 2910 tos = info->key.tos; 2911 fl4.flowi4_tos = RT_TOS(tos); 2912 2913 rt = ip_route_output_key(net, &fl4); 2914 if (IS_ERR(rt)) { 2915 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2916 return ERR_PTR(-ENETUNREACH); 2917 } 2918 if (rt->dst.dev == dev) { /* is this necessary? */ 2919 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2920 ip_rt_put(rt); 2921 return ERR_PTR(-ELOOP); 2922 } 2923 #ifdef CONFIG_DST_CACHE 2924 if (use_cache) 2925 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2926 #endif 2927 *saddr = fl4.saddr; 2928 return rt; 2929 } 2930 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2931 2932 /* called with rcu_read_lock held */ 2933 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2934 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2935 struct sk_buff *skb, u32 portid, u32 seq, 2936 unsigned int flags) 2937 { 2938 struct rtmsg *r; 2939 struct nlmsghdr *nlh; 2940 unsigned long expires = 0; 2941 u32 error; 2942 u32 metrics[RTAX_MAX]; 2943 2944 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2945 if (!nlh) 2946 return -EMSGSIZE; 2947 2948 r = nlmsg_data(nlh); 2949 r->rtm_family = AF_INET; 2950 r->rtm_dst_len = 32; 2951 r->rtm_src_len = 0; 2952 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2953 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2954 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2955 goto nla_put_failure; 2956 r->rtm_type = rt->rt_type; 2957 r->rtm_scope = RT_SCOPE_UNIVERSE; 2958 r->rtm_protocol = RTPROT_UNSPEC; 2959 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2960 if (rt->rt_flags & RTCF_NOTIFY) 2961 r->rtm_flags |= RTM_F_NOTIFY; 2962 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2963 r->rtm_flags |= RTCF_DOREDIRECT; 2964 2965 if (nla_put_in_addr(skb, RTA_DST, dst)) 2966 goto nla_put_failure; 2967 if (src) { 2968 r->rtm_src_len = 32; 2969 if (nla_put_in_addr(skb, RTA_SRC, src)) 2970 goto nla_put_failure; 2971 } 2972 if (rt->dst.dev && 2973 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2974 goto nla_put_failure; 2975 if (rt->dst.lwtstate && 2976 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2977 goto nla_put_failure; 2978 #ifdef CONFIG_IP_ROUTE_CLASSID 2979 if (rt->dst.tclassid && 2980 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2981 goto nla_put_failure; 2982 #endif 2983 if (fl4 && !rt_is_input_route(rt) && 2984 fl4->saddr != src) { 2985 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2986 goto nla_put_failure; 2987 } 2988 if (rt->rt_uses_gateway) { 2989 if (rt->rt_gw_family == AF_INET && 2990 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2991 goto nla_put_failure; 2992 } else if (rt->rt_gw_family == AF_INET6) { 2993 int alen = sizeof(struct in6_addr); 2994 struct nlattr *nla; 2995 struct rtvia *via; 2996 2997 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2998 if (!nla) 2999 goto nla_put_failure; 3000 3001 via = nla_data(nla); 3002 via->rtvia_family = AF_INET6; 3003 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3004 } 3005 } 3006 3007 expires = rt->dst.expires; 3008 if (expires) { 3009 unsigned long now = jiffies; 3010 3011 if (time_before(now, expires)) 3012 expires -= now; 3013 else 3014 expires = 0; 3015 } 3016 3017 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3018 if (rt->rt_pmtu && expires) 3019 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3020 if (rt->rt_mtu_locked && expires) 3021 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3022 if (rtnetlink_put_metrics(skb, metrics) < 0) 3023 goto nla_put_failure; 3024 3025 if (fl4) { 3026 if (fl4->flowi4_mark && 3027 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3028 goto nla_put_failure; 3029 3030 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3031 nla_put_u32(skb, RTA_UID, 3032 from_kuid_munged(current_user_ns(), 3033 fl4->flowi4_uid))) 3034 goto nla_put_failure; 3035 3036 if (rt_is_input_route(rt)) { 3037 #ifdef CONFIG_IP_MROUTE 3038 if (ipv4_is_multicast(dst) && 3039 !ipv4_is_local_multicast(dst) && 3040 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3041 int err = ipmr_get_route(net, skb, 3042 fl4->saddr, fl4->daddr, 3043 r, portid); 3044 3045 if (err <= 0) { 3046 if (err == 0) 3047 return 0; 3048 goto nla_put_failure; 3049 } 3050 } else 3051 #endif 3052 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3053 goto nla_put_failure; 3054 } 3055 } 3056 3057 error = rt->dst.error; 3058 3059 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3060 goto nla_put_failure; 3061 3062 nlmsg_end(skb, nlh); 3063 return 0; 3064 3065 nla_put_failure: 3066 nlmsg_cancel(skb, nlh); 3067 return -EMSGSIZE; 3068 } 3069 3070 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3071 struct netlink_callback *cb, u32 table_id, 3072 struct fnhe_hash_bucket *bucket, int genid, 3073 int *fa_index, int fa_start, unsigned int flags) 3074 { 3075 int i; 3076 3077 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3078 struct fib_nh_exception *fnhe; 3079 3080 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3081 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3082 struct rtable *rt; 3083 int err; 3084 3085 if (*fa_index < fa_start) 3086 goto next; 3087 3088 if (fnhe->fnhe_genid != genid) 3089 goto next; 3090 3091 if (fnhe->fnhe_expires && 3092 time_after(jiffies, fnhe->fnhe_expires)) 3093 goto next; 3094 3095 rt = rcu_dereference(fnhe->fnhe_rth_input); 3096 if (!rt) 3097 rt = rcu_dereference(fnhe->fnhe_rth_output); 3098 if (!rt) 3099 goto next; 3100 3101 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3102 table_id, NULL, skb, 3103 NETLINK_CB(cb->skb).portid, 3104 cb->nlh->nlmsg_seq, flags); 3105 if (err) 3106 return err; 3107 next: 3108 (*fa_index)++; 3109 } 3110 } 3111 3112 return 0; 3113 } 3114 3115 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3116 u32 table_id, struct fib_info *fi, 3117 int *fa_index, int fa_start, unsigned int flags) 3118 { 3119 struct net *net = sock_net(cb->skb->sk); 3120 int nhsel, genid = fnhe_genid(net); 3121 3122 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3123 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3124 struct fnhe_hash_bucket *bucket; 3125 int err; 3126 3127 if (nhc->nhc_flags & RTNH_F_DEAD) 3128 continue; 3129 3130 rcu_read_lock(); 3131 bucket = rcu_dereference(nhc->nhc_exceptions); 3132 err = 0; 3133 if (bucket) 3134 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3135 genid, fa_index, fa_start, 3136 flags); 3137 rcu_read_unlock(); 3138 if (err) 3139 return err; 3140 } 3141 3142 return 0; 3143 } 3144 3145 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3146 u8 ip_proto, __be16 sport, 3147 __be16 dport) 3148 { 3149 struct sk_buff *skb; 3150 struct iphdr *iph; 3151 3152 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3153 if (!skb) 3154 return NULL; 3155 3156 /* Reserve room for dummy headers, this skb can pass 3157 * through good chunk of routing engine. 3158 */ 3159 skb_reset_mac_header(skb); 3160 skb_reset_network_header(skb); 3161 skb->protocol = htons(ETH_P_IP); 3162 iph = skb_put(skb, sizeof(struct iphdr)); 3163 iph->protocol = ip_proto; 3164 iph->saddr = src; 3165 iph->daddr = dst; 3166 iph->version = 0x4; 3167 iph->frag_off = 0; 3168 iph->ihl = 0x5; 3169 skb_set_transport_header(skb, skb->len); 3170 3171 switch (iph->protocol) { 3172 case IPPROTO_UDP: { 3173 struct udphdr *udph; 3174 3175 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3176 udph->source = sport; 3177 udph->dest = dport; 3178 udph->len = htons(sizeof(struct udphdr)); 3179 udph->check = 0; 3180 break; 3181 } 3182 case IPPROTO_TCP: { 3183 struct tcphdr *tcph; 3184 3185 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3186 tcph->source = sport; 3187 tcph->dest = dport; 3188 tcph->doff = sizeof(struct tcphdr) / 4; 3189 tcph->rst = 1; 3190 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3191 src, dst, 0); 3192 break; 3193 } 3194 case IPPROTO_ICMP: { 3195 struct icmphdr *icmph; 3196 3197 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3198 icmph->type = ICMP_ECHO; 3199 icmph->code = 0; 3200 } 3201 } 3202 3203 return skb; 3204 } 3205 3206 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3207 const struct nlmsghdr *nlh, 3208 struct nlattr **tb, 3209 struct netlink_ext_ack *extack) 3210 { 3211 struct rtmsg *rtm; 3212 int i, err; 3213 3214 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3215 NL_SET_ERR_MSG(extack, 3216 "ipv4: Invalid header for route get request"); 3217 return -EINVAL; 3218 } 3219 3220 if (!netlink_strict_get_check(skb)) 3221 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3222 rtm_ipv4_policy, extack); 3223 3224 rtm = nlmsg_data(nlh); 3225 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3226 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3227 rtm->rtm_table || rtm->rtm_protocol || 3228 rtm->rtm_scope || rtm->rtm_type) { 3229 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3230 return -EINVAL; 3231 } 3232 3233 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3234 RTM_F_LOOKUP_TABLE | 3235 RTM_F_FIB_MATCH)) { 3236 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3237 return -EINVAL; 3238 } 3239 3240 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3241 rtm_ipv4_policy, extack); 3242 if (err) 3243 return err; 3244 3245 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3246 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3247 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3248 return -EINVAL; 3249 } 3250 3251 for (i = 0; i <= RTA_MAX; i++) { 3252 if (!tb[i]) 3253 continue; 3254 3255 switch (i) { 3256 case RTA_IIF: 3257 case RTA_OIF: 3258 case RTA_SRC: 3259 case RTA_DST: 3260 case RTA_IP_PROTO: 3261 case RTA_SPORT: 3262 case RTA_DPORT: 3263 case RTA_MARK: 3264 case RTA_UID: 3265 break; 3266 default: 3267 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3268 return -EINVAL; 3269 } 3270 } 3271 3272 return 0; 3273 } 3274 3275 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3276 struct netlink_ext_ack *extack) 3277 { 3278 struct net *net = sock_net(in_skb->sk); 3279 struct nlattr *tb[RTA_MAX+1]; 3280 u32 table_id = RT_TABLE_MAIN; 3281 __be16 sport = 0, dport = 0; 3282 struct fib_result res = {}; 3283 u8 ip_proto = IPPROTO_UDP; 3284 struct rtable *rt = NULL; 3285 struct sk_buff *skb; 3286 struct rtmsg *rtm; 3287 struct flowi4 fl4 = {}; 3288 __be32 dst = 0; 3289 __be32 src = 0; 3290 kuid_t uid; 3291 u32 iif; 3292 int err; 3293 int mark; 3294 3295 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3296 if (err < 0) 3297 return err; 3298 3299 rtm = nlmsg_data(nlh); 3300 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3301 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3302 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3303 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3304 if (tb[RTA_UID]) 3305 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3306 else 3307 uid = (iif ? INVALID_UID : current_uid()); 3308 3309 if (tb[RTA_IP_PROTO]) { 3310 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3311 &ip_proto, AF_INET, extack); 3312 if (err) 3313 return err; 3314 } 3315 3316 if (tb[RTA_SPORT]) 3317 sport = nla_get_be16(tb[RTA_SPORT]); 3318 3319 if (tb[RTA_DPORT]) 3320 dport = nla_get_be16(tb[RTA_DPORT]); 3321 3322 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3323 if (!skb) 3324 return -ENOBUFS; 3325 3326 fl4.daddr = dst; 3327 fl4.saddr = src; 3328 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3329 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3330 fl4.flowi4_mark = mark; 3331 fl4.flowi4_uid = uid; 3332 if (sport) 3333 fl4.fl4_sport = sport; 3334 if (dport) 3335 fl4.fl4_dport = dport; 3336 fl4.flowi4_proto = ip_proto; 3337 3338 rcu_read_lock(); 3339 3340 if (iif) { 3341 struct net_device *dev; 3342 3343 dev = dev_get_by_index_rcu(net, iif); 3344 if (!dev) { 3345 err = -ENODEV; 3346 goto errout_rcu; 3347 } 3348 3349 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3350 skb->dev = dev; 3351 skb->mark = mark; 3352 err = ip_route_input_rcu(skb, dst, src, 3353 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3354 &res); 3355 3356 rt = skb_rtable(skb); 3357 if (err == 0 && rt->dst.error) 3358 err = -rt->dst.error; 3359 } else { 3360 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3361 skb->dev = net->loopback_dev; 3362 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3363 err = 0; 3364 if (IS_ERR(rt)) 3365 err = PTR_ERR(rt); 3366 else 3367 skb_dst_set(skb, &rt->dst); 3368 } 3369 3370 if (err) 3371 goto errout_rcu; 3372 3373 if (rtm->rtm_flags & RTM_F_NOTIFY) 3374 rt->rt_flags |= RTCF_NOTIFY; 3375 3376 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3377 table_id = res.table ? res.table->tb_id : 0; 3378 3379 /* reset skb for netlink reply msg */ 3380 skb_trim(skb, 0); 3381 skb_reset_network_header(skb); 3382 skb_reset_transport_header(skb); 3383 skb_reset_mac_header(skb); 3384 3385 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3386 struct fib_rt_info fri; 3387 3388 if (!res.fi) { 3389 err = fib_props[res.type].error; 3390 if (!err) 3391 err = -EHOSTUNREACH; 3392 goto errout_rcu; 3393 } 3394 fri.fi = res.fi; 3395 fri.tb_id = table_id; 3396 fri.dst = res.prefix; 3397 fri.dst_len = res.prefixlen; 3398 fri.dscp = inet_dsfield_to_dscp(fl4.flowi4_tos); 3399 fri.type = rt->rt_type; 3400 fri.offload = 0; 3401 fri.trap = 0; 3402 fri.offload_failed = 0; 3403 if (res.fa_head) { 3404 struct fib_alias *fa; 3405 3406 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3407 u8 slen = 32 - fri.dst_len; 3408 3409 if (fa->fa_slen == slen && 3410 fa->tb_id == fri.tb_id && 3411 fa->fa_dscp == fri.dscp && 3412 fa->fa_info == res.fi && 3413 fa->fa_type == fri.type) { 3414 fri.offload = READ_ONCE(fa->offload); 3415 fri.trap = READ_ONCE(fa->trap); 3416 break; 3417 } 3418 } 3419 } 3420 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3421 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3422 } else { 3423 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3424 NETLINK_CB(in_skb).portid, 3425 nlh->nlmsg_seq, 0); 3426 } 3427 if (err < 0) 3428 goto errout_rcu; 3429 3430 rcu_read_unlock(); 3431 3432 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3433 3434 errout_free: 3435 return err; 3436 errout_rcu: 3437 rcu_read_unlock(); 3438 kfree_skb(skb); 3439 goto errout_free; 3440 } 3441 3442 void ip_rt_multicast_event(struct in_device *in_dev) 3443 { 3444 rt_cache_flush(dev_net(in_dev->dev)); 3445 } 3446 3447 #ifdef CONFIG_SYSCTL 3448 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3449 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3450 static int ip_rt_gc_elasticity __read_mostly = 8; 3451 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3452 3453 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3454 void *buffer, size_t *lenp, loff_t *ppos) 3455 { 3456 struct net *net = (struct net *)__ctl->extra1; 3457 3458 if (write) { 3459 rt_cache_flush(net); 3460 fnhe_genid_bump(net); 3461 return 0; 3462 } 3463 3464 return -EINVAL; 3465 } 3466 3467 static struct ctl_table ipv4_route_table[] = { 3468 { 3469 .procname = "gc_thresh", 3470 .data = &ipv4_dst_ops.gc_thresh, 3471 .maxlen = sizeof(int), 3472 .mode = 0644, 3473 .proc_handler = proc_dointvec, 3474 }, 3475 { 3476 .procname = "max_size", 3477 .data = &ip_rt_max_size, 3478 .maxlen = sizeof(int), 3479 .mode = 0644, 3480 .proc_handler = proc_dointvec, 3481 }, 3482 { 3483 /* Deprecated. Use gc_min_interval_ms */ 3484 3485 .procname = "gc_min_interval", 3486 .data = &ip_rt_gc_min_interval, 3487 .maxlen = sizeof(int), 3488 .mode = 0644, 3489 .proc_handler = proc_dointvec_jiffies, 3490 }, 3491 { 3492 .procname = "gc_min_interval_ms", 3493 .data = &ip_rt_gc_min_interval, 3494 .maxlen = sizeof(int), 3495 .mode = 0644, 3496 .proc_handler = proc_dointvec_ms_jiffies, 3497 }, 3498 { 3499 .procname = "gc_timeout", 3500 .data = &ip_rt_gc_timeout, 3501 .maxlen = sizeof(int), 3502 .mode = 0644, 3503 .proc_handler = proc_dointvec_jiffies, 3504 }, 3505 { 3506 .procname = "gc_interval", 3507 .data = &ip_rt_gc_interval, 3508 .maxlen = sizeof(int), 3509 .mode = 0644, 3510 .proc_handler = proc_dointvec_jiffies, 3511 }, 3512 { 3513 .procname = "redirect_load", 3514 .data = &ip_rt_redirect_load, 3515 .maxlen = sizeof(int), 3516 .mode = 0644, 3517 .proc_handler = proc_dointvec, 3518 }, 3519 { 3520 .procname = "redirect_number", 3521 .data = &ip_rt_redirect_number, 3522 .maxlen = sizeof(int), 3523 .mode = 0644, 3524 .proc_handler = proc_dointvec, 3525 }, 3526 { 3527 .procname = "redirect_silence", 3528 .data = &ip_rt_redirect_silence, 3529 .maxlen = sizeof(int), 3530 .mode = 0644, 3531 .proc_handler = proc_dointvec, 3532 }, 3533 { 3534 .procname = "error_cost", 3535 .data = &ip_rt_error_cost, 3536 .maxlen = sizeof(int), 3537 .mode = 0644, 3538 .proc_handler = proc_dointvec, 3539 }, 3540 { 3541 .procname = "error_burst", 3542 .data = &ip_rt_error_burst, 3543 .maxlen = sizeof(int), 3544 .mode = 0644, 3545 .proc_handler = proc_dointvec, 3546 }, 3547 { 3548 .procname = "gc_elasticity", 3549 .data = &ip_rt_gc_elasticity, 3550 .maxlen = sizeof(int), 3551 .mode = 0644, 3552 .proc_handler = proc_dointvec, 3553 }, 3554 { } 3555 }; 3556 3557 static const char ipv4_route_flush_procname[] = "flush"; 3558 3559 static struct ctl_table ipv4_route_netns_table[] = { 3560 { 3561 .procname = ipv4_route_flush_procname, 3562 .maxlen = sizeof(int), 3563 .mode = 0200, 3564 .proc_handler = ipv4_sysctl_rtcache_flush, 3565 }, 3566 { 3567 .procname = "min_pmtu", 3568 .data = &init_net.ipv4.ip_rt_min_pmtu, 3569 .maxlen = sizeof(int), 3570 .mode = 0644, 3571 .proc_handler = proc_dointvec_minmax, 3572 .extra1 = &ip_min_valid_pmtu, 3573 }, 3574 { 3575 .procname = "mtu_expires", 3576 .data = &init_net.ipv4.ip_rt_mtu_expires, 3577 .maxlen = sizeof(int), 3578 .mode = 0644, 3579 .proc_handler = proc_dointvec_jiffies, 3580 }, 3581 { 3582 .procname = "min_adv_mss", 3583 .data = &init_net.ipv4.ip_rt_min_advmss, 3584 .maxlen = sizeof(int), 3585 .mode = 0644, 3586 .proc_handler = proc_dointvec, 3587 }, 3588 { }, 3589 }; 3590 3591 static __net_init int sysctl_route_net_init(struct net *net) 3592 { 3593 struct ctl_table *tbl; 3594 3595 tbl = ipv4_route_netns_table; 3596 if (!net_eq(net, &init_net)) { 3597 int i; 3598 3599 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3600 if (!tbl) 3601 goto err_dup; 3602 3603 /* Don't export non-whitelisted sysctls to unprivileged users */ 3604 if (net->user_ns != &init_user_ns) { 3605 if (tbl[0].procname != ipv4_route_flush_procname) 3606 tbl[0].procname = NULL; 3607 } 3608 3609 /* Update the variables to point into the current struct net 3610 * except for the first element flush 3611 */ 3612 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3613 tbl[i].data += (void *)net - (void *)&init_net; 3614 } 3615 tbl[0].extra1 = net; 3616 3617 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3618 if (!net->ipv4.route_hdr) 3619 goto err_reg; 3620 return 0; 3621 3622 err_reg: 3623 if (tbl != ipv4_route_netns_table) 3624 kfree(tbl); 3625 err_dup: 3626 return -ENOMEM; 3627 } 3628 3629 static __net_exit void sysctl_route_net_exit(struct net *net) 3630 { 3631 struct ctl_table *tbl; 3632 3633 tbl = net->ipv4.route_hdr->ctl_table_arg; 3634 unregister_net_sysctl_table(net->ipv4.route_hdr); 3635 BUG_ON(tbl == ipv4_route_netns_table); 3636 kfree(tbl); 3637 } 3638 3639 static __net_initdata struct pernet_operations sysctl_route_ops = { 3640 .init = sysctl_route_net_init, 3641 .exit = sysctl_route_net_exit, 3642 }; 3643 #endif 3644 3645 static __net_init int netns_ip_rt_init(struct net *net) 3646 { 3647 /* Set default value for namespaceified sysctls */ 3648 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3649 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3650 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3651 return 0; 3652 } 3653 3654 static struct pernet_operations __net_initdata ip_rt_ops = { 3655 .init = netns_ip_rt_init, 3656 }; 3657 3658 static __net_init int rt_genid_init(struct net *net) 3659 { 3660 atomic_set(&net->ipv4.rt_genid, 0); 3661 atomic_set(&net->fnhe_genid, 0); 3662 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3663 return 0; 3664 } 3665 3666 static __net_initdata struct pernet_operations rt_genid_ops = { 3667 .init = rt_genid_init, 3668 }; 3669 3670 static int __net_init ipv4_inetpeer_init(struct net *net) 3671 { 3672 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3673 3674 if (!bp) 3675 return -ENOMEM; 3676 inet_peer_base_init(bp); 3677 net->ipv4.peers = bp; 3678 return 0; 3679 } 3680 3681 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3682 { 3683 struct inet_peer_base *bp = net->ipv4.peers; 3684 3685 net->ipv4.peers = NULL; 3686 inetpeer_invalidate_tree(bp); 3687 kfree(bp); 3688 } 3689 3690 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3691 .init = ipv4_inetpeer_init, 3692 .exit = ipv4_inetpeer_exit, 3693 }; 3694 3695 #ifdef CONFIG_IP_ROUTE_CLASSID 3696 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3697 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3698 3699 int __init ip_rt_init(void) 3700 { 3701 void *idents_hash; 3702 int cpu; 3703 3704 /* For modern hosts, this will use 2 MB of memory */ 3705 idents_hash = alloc_large_system_hash("IP idents", 3706 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3707 0, 3708 16, /* one bucket per 64 KB */ 3709 HASH_ZERO, 3710 NULL, 3711 &ip_idents_mask, 3712 2048, 3713 256*1024); 3714 3715 ip_idents = idents_hash; 3716 3717 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3718 3719 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3720 3721 for_each_possible_cpu(cpu) { 3722 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3723 3724 INIT_LIST_HEAD(&ul->head); 3725 INIT_LIST_HEAD(&ul->quarantine); 3726 spin_lock_init(&ul->lock); 3727 } 3728 #ifdef CONFIG_IP_ROUTE_CLASSID 3729 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3730 if (!ip_rt_acct) 3731 panic("IP: failed to allocate ip_rt_acct\n"); 3732 #endif 3733 3734 ipv4_dst_ops.kmem_cachep = 3735 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3736 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3737 3738 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3739 3740 if (dst_entries_init(&ipv4_dst_ops) < 0) 3741 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3742 3743 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3744 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3745 3746 ipv4_dst_ops.gc_thresh = ~0; 3747 ip_rt_max_size = INT_MAX; 3748 3749 devinet_init(); 3750 ip_fib_init(); 3751 3752 if (ip_rt_proc_init()) 3753 pr_err("Unable to create route proc files\n"); 3754 #ifdef CONFIG_XFRM 3755 xfrm_init(); 3756 xfrm4_init(); 3757 #endif 3758 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3759 RTNL_FLAG_DOIT_UNLOCKED); 3760 3761 #ifdef CONFIG_SYSCTL 3762 register_pernet_subsys(&sysctl_route_ops); 3763 #endif 3764 register_pernet_subsys(&ip_rt_ops); 3765 register_pernet_subsys(&rt_genid_ops); 3766 register_pernet_subsys(&ipv4_inetpeer_ops); 3767 return 0; 3768 } 3769 3770 #ifdef CONFIG_SYSCTL 3771 /* 3772 * We really need to sanitize the damn ipv4 init order, then all 3773 * this nonsense will go away. 3774 */ 3775 void __init ip_static_sysctl_init(void) 3776 { 3777 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3778 } 3779 #endif 3780