1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_FL_TOS(oldflp4) \ 110 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 111 112 #define RT_GC_TIMEOUT (300*HZ) 113 114 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 115 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 116 #define DEFAULT_MIN_ADVMSS 256 117 static int ip_rt_max_size; 118 static int ip_rt_redirect_number __read_mostly = 9; 119 static int ip_rt_redirect_load __read_mostly = HZ / 50; 120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 121 static int ip_rt_error_cost __read_mostly = HZ; 122 static int ip_rt_error_burst __read_mostly = 5 * HZ; 123 124 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 125 126 /* 127 * Interface to generic destination cache. 128 */ 129 130 INDIRECT_CALLABLE_SCOPE 131 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 133 INDIRECT_CALLABLE_SCOPE 134 unsigned int ipv4_mtu(const struct dst_entry *dst); 135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 136 static void ipv4_link_failure(struct sk_buff *skb); 137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 138 struct sk_buff *skb, u32 mtu, 139 bool confirm_neigh); 140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 141 struct sk_buff *skb); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 144 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 145 { 146 WARN_ON(1); 147 return NULL; 148 } 149 150 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 151 struct sk_buff *skb, 152 const void *daddr); 153 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 154 155 static struct dst_ops ipv4_dst_ops = { 156 .family = AF_INET, 157 .check = ipv4_dst_check, 158 .default_advmss = ipv4_default_advmss, 159 .mtu = ipv4_mtu, 160 .cow_metrics = ipv4_cow_metrics, 161 .destroy = ipv4_dst_destroy, 162 .negative_advice = ipv4_negative_advice, 163 .link_failure = ipv4_link_failure, 164 .update_pmtu = ip_rt_update_pmtu, 165 .redirect = ip_do_redirect, 166 .local_out = __ip_local_out, 167 .neigh_lookup = ipv4_neigh_lookup, 168 .confirm_neigh = ipv4_confirm_neigh, 169 }; 170 171 #define ECN_OR_COST(class) TC_PRIO_##class 172 173 const __u8 ip_tos2prio[16] = { 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BESTEFFORT, 177 ECN_OR_COST(BESTEFFORT), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_BULK, 181 ECN_OR_COST(BULK), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE, 185 ECN_OR_COST(INTERACTIVE), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK), 188 TC_PRIO_INTERACTIVE_BULK, 189 ECN_OR_COST(INTERACTIVE_BULK) 190 }; 191 EXPORT_SYMBOL(ip_tos2prio); 192 193 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 196 #ifdef CONFIG_PROC_FS 197 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 198 { 199 if (*pos) 200 return NULL; 201 return SEQ_START_TOKEN; 202 } 203 204 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 205 { 206 ++*pos; 207 return NULL; 208 } 209 210 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 211 { 212 } 213 214 static int rt_cache_seq_show(struct seq_file *seq, void *v) 215 { 216 if (v == SEQ_START_TOKEN) 217 seq_printf(seq, "%-127s\n", 218 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 219 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 220 "HHUptod\tSpecDst"); 221 return 0; 222 } 223 224 static const struct seq_operations rt_cache_seq_ops = { 225 .start = rt_cache_seq_start, 226 .next = rt_cache_seq_next, 227 .stop = rt_cache_seq_stop, 228 .show = rt_cache_seq_show, 229 }; 230 231 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 232 { 233 int cpu; 234 235 if (*pos == 0) 236 return SEQ_START_TOKEN; 237 238 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 239 if (!cpu_possible(cpu)) 240 continue; 241 *pos = cpu+1; 242 return &per_cpu(rt_cache_stat, cpu); 243 } 244 return NULL; 245 } 246 247 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 248 { 249 int cpu; 250 251 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 252 if (!cpu_possible(cpu)) 253 continue; 254 *pos = cpu+1; 255 return &per_cpu(rt_cache_stat, cpu); 256 } 257 (*pos)++; 258 return NULL; 259 260 } 261 262 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 263 { 264 265 } 266 267 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 268 { 269 struct rt_cache_stat *st = v; 270 271 if (v == SEQ_START_TOKEN) { 272 seq_puts(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 273 return 0; 274 } 275 276 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 277 "%08x %08x %08x %08x %08x %08x " 278 "%08x %08x %08x %08x\n", 279 dst_entries_get_slow(&ipv4_dst_ops), 280 0, /* st->in_hit */ 281 st->in_slow_tot, 282 st->in_slow_mc, 283 st->in_no_route, 284 st->in_brd, 285 st->in_martian_dst, 286 st->in_martian_src, 287 288 0, /* st->out_hit */ 289 st->out_slow_tot, 290 st->out_slow_mc, 291 292 0, /* st->gc_total */ 293 0, /* st->gc_ignored */ 294 0, /* st->gc_goal_miss */ 295 0, /* st->gc_dst_overflow */ 296 0, /* st->in_hlist_search */ 297 0 /* st->out_hlist_search */ 298 ); 299 return 0; 300 } 301 302 static const struct seq_operations rt_cpu_seq_ops = { 303 .start = rt_cpu_seq_start, 304 .next = rt_cpu_seq_next, 305 .stop = rt_cpu_seq_stop, 306 .show = rt_cpu_seq_show, 307 }; 308 309 #ifdef CONFIG_IP_ROUTE_CLASSID 310 static int rt_acct_proc_show(struct seq_file *m, void *v) 311 { 312 struct ip_rt_acct *dst, *src; 313 unsigned int i, j; 314 315 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 316 if (!dst) 317 return -ENOMEM; 318 319 for_each_possible_cpu(i) { 320 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 321 for (j = 0; j < 256; j++) { 322 dst[j].o_bytes += src[j].o_bytes; 323 dst[j].o_packets += src[j].o_packets; 324 dst[j].i_bytes += src[j].i_bytes; 325 dst[j].i_packets += src[j].i_packets; 326 } 327 } 328 329 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 330 kfree(dst); 331 return 0; 332 } 333 #endif 334 335 static int __net_init ip_rt_do_proc_init(struct net *net) 336 { 337 struct proc_dir_entry *pde; 338 339 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 340 &rt_cache_seq_ops); 341 if (!pde) 342 goto err1; 343 344 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 345 &rt_cpu_seq_ops); 346 if (!pde) 347 goto err2; 348 349 #ifdef CONFIG_IP_ROUTE_CLASSID 350 pde = proc_create_single("rt_acct", 0, net->proc_net, 351 rt_acct_proc_show); 352 if (!pde) 353 goto err3; 354 #endif 355 return 0; 356 357 #ifdef CONFIG_IP_ROUTE_CLASSID 358 err3: 359 remove_proc_entry("rt_cache", net->proc_net_stat); 360 #endif 361 err2: 362 remove_proc_entry("rt_cache", net->proc_net); 363 err1: 364 return -ENOMEM; 365 } 366 367 static void __net_exit ip_rt_do_proc_exit(struct net *net) 368 { 369 remove_proc_entry("rt_cache", net->proc_net_stat); 370 remove_proc_entry("rt_cache", net->proc_net); 371 #ifdef CONFIG_IP_ROUTE_CLASSID 372 remove_proc_entry("rt_acct", net->proc_net); 373 #endif 374 } 375 376 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 377 .init = ip_rt_do_proc_init, 378 .exit = ip_rt_do_proc_exit, 379 }; 380 381 static int __init ip_rt_proc_init(void) 382 { 383 return register_pernet_subsys(&ip_rt_proc_ops); 384 } 385 386 #else 387 static inline int ip_rt_proc_init(void) 388 { 389 return 0; 390 } 391 #endif /* CONFIG_PROC_FS */ 392 393 static inline bool rt_is_expired(const struct rtable *rth) 394 { 395 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 396 } 397 398 void rt_cache_flush(struct net *net) 399 { 400 rt_genid_bump_ipv4(net); 401 } 402 403 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 404 struct sk_buff *skb, 405 const void *daddr) 406 { 407 const struct rtable *rt = container_of(dst, struct rtable, dst); 408 struct net_device *dev = dst->dev; 409 struct neighbour *n; 410 411 rcu_read_lock_bh(); 412 413 if (likely(rt->rt_gw_family == AF_INET)) { 414 n = ip_neigh_gw4(dev, rt->rt_gw4); 415 } else if (rt->rt_gw_family == AF_INET6) { 416 n = ip_neigh_gw6(dev, &rt->rt_gw6); 417 } else { 418 __be32 pkey; 419 420 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 421 n = ip_neigh_gw4(dev, pkey); 422 } 423 424 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 425 n = NULL; 426 427 rcu_read_unlock_bh(); 428 429 return n; 430 } 431 432 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 433 { 434 const struct rtable *rt = container_of(dst, struct rtable, dst); 435 struct net_device *dev = dst->dev; 436 const __be32 *pkey = daddr; 437 438 if (rt->rt_gw_family == AF_INET) { 439 pkey = (const __be32 *)&rt->rt_gw4; 440 } else if (rt->rt_gw_family == AF_INET6) { 441 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 442 } else if (!daddr || 443 (rt->rt_flags & 444 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 445 return; 446 } 447 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 448 } 449 450 /* Hash tables of size 2048..262144 depending on RAM size. 451 * Each bucket uses 8 bytes. 452 */ 453 static u32 ip_idents_mask __read_mostly; 454 static atomic_t *ip_idents __read_mostly; 455 static u32 *ip_tstamps __read_mostly; 456 457 /* In order to protect privacy, we add a perturbation to identifiers 458 * if one generator is seldom used. This makes hard for an attacker 459 * to infer how many packets were sent between two points in time. 460 */ 461 static u32 ip_idents_reserve(u32 hash, int segs) 462 { 463 u32 bucket, old, now = (u32)jiffies; 464 atomic_t *p_id; 465 u32 *p_tstamp; 466 u32 delta = 0; 467 468 bucket = hash & ip_idents_mask; 469 p_tstamp = ip_tstamps + bucket; 470 p_id = ip_idents + bucket; 471 old = READ_ONCE(*p_tstamp); 472 473 if (old != now && cmpxchg(p_tstamp, old, now) == old) 474 delta = prandom_u32_max(now - old); 475 476 /* If UBSAN reports an error there, please make sure your compiler 477 * supports -fno-strict-overflow before reporting it that was a bug 478 * in UBSAN, and it has been fixed in GCC-8. 479 */ 480 return atomic_add_return(segs + delta, p_id) - segs; 481 } 482 483 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 484 { 485 u32 hash, id; 486 487 /* Note the following code is not safe, but this is okay. */ 488 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 489 get_random_bytes(&net->ipv4.ip_id_key, 490 sizeof(net->ipv4.ip_id_key)); 491 492 hash = siphash_3u32((__force u32)iph->daddr, 493 (__force u32)iph->saddr, 494 iph->protocol, 495 &net->ipv4.ip_id_key); 496 id = ip_idents_reserve(hash, segs); 497 iph->id = htons(id); 498 } 499 EXPORT_SYMBOL(__ip_select_ident); 500 501 static void ip_rt_fix_tos(struct flowi4 *fl4) 502 { 503 __u8 tos = RT_FL_TOS(fl4); 504 505 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 506 fl4->flowi4_scope = tos & RTO_ONLINK ? 507 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE; 508 } 509 510 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 511 const struct sock *sk, 512 const struct iphdr *iph, 513 int oif, u8 tos, 514 u8 prot, u32 mark, int flow_flags) 515 { 516 if (sk) { 517 const struct inet_sock *inet = inet_sk(sk); 518 519 oif = sk->sk_bound_dev_if; 520 mark = sk->sk_mark; 521 tos = RT_CONN_FLAGS(sk); 522 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 523 } 524 flowi4_init_output(fl4, oif, mark, tos, 525 RT_SCOPE_UNIVERSE, prot, 526 flow_flags, 527 iph->daddr, iph->saddr, 0, 0, 528 sock_net_uid(net, sk)); 529 } 530 531 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 532 const struct sock *sk) 533 { 534 const struct net *net = dev_net(skb->dev); 535 const struct iphdr *iph = ip_hdr(skb); 536 int oif = skb->dev->ifindex; 537 u8 tos = RT_TOS(iph->tos); 538 u8 prot = iph->protocol; 539 u32 mark = skb->mark; 540 541 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 542 } 543 544 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 545 { 546 const struct inet_sock *inet = inet_sk(sk); 547 const struct ip_options_rcu *inet_opt; 548 __be32 daddr = inet->inet_daddr; 549 550 rcu_read_lock(); 551 inet_opt = rcu_dereference(inet->inet_opt); 552 if (inet_opt && inet_opt->opt.srr) 553 daddr = inet_opt->opt.faddr; 554 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 555 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 556 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 557 inet_sk_flowi_flags(sk), 558 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 559 rcu_read_unlock(); 560 } 561 562 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 563 const struct sk_buff *skb) 564 { 565 if (skb) 566 build_skb_flow_key(fl4, skb, sk); 567 else 568 build_sk_flow_key(fl4, sk); 569 } 570 571 static DEFINE_SPINLOCK(fnhe_lock); 572 573 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 574 { 575 struct rtable *rt; 576 577 rt = rcu_dereference(fnhe->fnhe_rth_input); 578 if (rt) { 579 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 580 dst_dev_put(&rt->dst); 581 dst_release(&rt->dst); 582 } 583 rt = rcu_dereference(fnhe->fnhe_rth_output); 584 if (rt) { 585 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 586 dst_dev_put(&rt->dst); 587 dst_release(&rt->dst); 588 } 589 } 590 591 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 592 { 593 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 594 struct fib_nh_exception *fnhe, *oldest = NULL; 595 596 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 597 fnhe = rcu_dereference_protected(*fnhe_p, 598 lockdep_is_held(&fnhe_lock)); 599 if (!fnhe) 600 break; 601 if (!oldest || 602 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 603 oldest = fnhe; 604 oldest_p = fnhe_p; 605 } 606 } 607 fnhe_flush_routes(oldest); 608 *oldest_p = oldest->fnhe_next; 609 kfree_rcu(oldest, rcu); 610 } 611 612 static u32 fnhe_hashfun(__be32 daddr) 613 { 614 static siphash_aligned_key_t fnhe_hash_key; 615 u64 hval; 616 617 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 618 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 619 return hash_64(hval, FNHE_HASH_SHIFT); 620 } 621 622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 623 { 624 rt->rt_pmtu = fnhe->fnhe_pmtu; 625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 626 rt->dst.expires = fnhe->fnhe_expires; 627 628 if (fnhe->fnhe_gw) { 629 rt->rt_flags |= RTCF_REDIRECTED; 630 rt->rt_uses_gateway = 1; 631 rt->rt_gw_family = AF_INET; 632 rt->rt_gw4 = fnhe->fnhe_gw; 633 } 634 } 635 636 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 637 __be32 gw, u32 pmtu, bool lock, 638 unsigned long expires) 639 { 640 struct fnhe_hash_bucket *hash; 641 struct fib_nh_exception *fnhe; 642 struct rtable *rt; 643 u32 genid, hval; 644 unsigned int i; 645 int depth; 646 647 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 648 hval = fnhe_hashfun(daddr); 649 650 spin_lock_bh(&fnhe_lock); 651 652 hash = rcu_dereference(nhc->nhc_exceptions); 653 if (!hash) { 654 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 655 if (!hash) 656 goto out_unlock; 657 rcu_assign_pointer(nhc->nhc_exceptions, hash); 658 } 659 660 hash += hval; 661 662 depth = 0; 663 for (fnhe = rcu_dereference(hash->chain); fnhe; 664 fnhe = rcu_dereference(fnhe->fnhe_next)) { 665 if (fnhe->fnhe_daddr == daddr) 666 break; 667 depth++; 668 } 669 670 if (fnhe) { 671 if (fnhe->fnhe_genid != genid) 672 fnhe->fnhe_genid = genid; 673 if (gw) 674 fnhe->fnhe_gw = gw; 675 if (pmtu) { 676 fnhe->fnhe_pmtu = pmtu; 677 fnhe->fnhe_mtu_locked = lock; 678 } 679 fnhe->fnhe_expires = max(1UL, expires); 680 /* Update all cached dsts too */ 681 rt = rcu_dereference(fnhe->fnhe_rth_input); 682 if (rt) 683 fill_route_from_fnhe(rt, fnhe); 684 rt = rcu_dereference(fnhe->fnhe_rth_output); 685 if (rt) 686 fill_route_from_fnhe(rt, fnhe); 687 } else { 688 /* Randomize max depth to avoid some side channels attacks. */ 689 int max_depth = FNHE_RECLAIM_DEPTH + 690 prandom_u32_max(FNHE_RECLAIM_DEPTH); 691 692 while (depth > max_depth) { 693 fnhe_remove_oldest(hash); 694 depth--; 695 } 696 697 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 698 if (!fnhe) 699 goto out_unlock; 700 701 fnhe->fnhe_next = hash->chain; 702 703 fnhe->fnhe_genid = genid; 704 fnhe->fnhe_daddr = daddr; 705 fnhe->fnhe_gw = gw; 706 fnhe->fnhe_pmtu = pmtu; 707 fnhe->fnhe_mtu_locked = lock; 708 fnhe->fnhe_expires = max(1UL, expires); 709 710 rcu_assign_pointer(hash->chain, fnhe); 711 712 /* Exception created; mark the cached routes for the nexthop 713 * stale, so anyone caching it rechecks if this exception 714 * applies to them. 715 */ 716 rt = rcu_dereference(nhc->nhc_rth_input); 717 if (rt) 718 rt->dst.obsolete = DST_OBSOLETE_KILL; 719 720 for_each_possible_cpu(i) { 721 struct rtable __rcu **prt; 722 723 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 724 rt = rcu_dereference(*prt); 725 if (rt) 726 rt->dst.obsolete = DST_OBSOLETE_KILL; 727 } 728 } 729 730 fnhe->fnhe_stamp = jiffies; 731 732 out_unlock: 733 spin_unlock_bh(&fnhe_lock); 734 } 735 736 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 737 bool kill_route) 738 { 739 __be32 new_gw = icmp_hdr(skb)->un.gateway; 740 __be32 old_gw = ip_hdr(skb)->saddr; 741 struct net_device *dev = skb->dev; 742 struct in_device *in_dev; 743 struct fib_result res; 744 struct neighbour *n; 745 struct net *net; 746 747 switch (icmp_hdr(skb)->code & 7) { 748 case ICMP_REDIR_NET: 749 case ICMP_REDIR_NETTOS: 750 case ICMP_REDIR_HOST: 751 case ICMP_REDIR_HOSTTOS: 752 break; 753 754 default: 755 return; 756 } 757 758 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 759 return; 760 761 in_dev = __in_dev_get_rcu(dev); 762 if (!in_dev) 763 return; 764 765 net = dev_net(dev); 766 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 767 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 768 ipv4_is_zeronet(new_gw)) 769 goto reject_redirect; 770 771 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 772 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 773 goto reject_redirect; 774 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 775 goto reject_redirect; 776 } else { 777 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 778 goto reject_redirect; 779 } 780 781 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 782 if (!n) 783 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 784 if (!IS_ERR(n)) { 785 if (!(n->nud_state & NUD_VALID)) { 786 neigh_event_send(n, NULL); 787 } else { 788 if (fib_lookup(net, fl4, &res, 0) == 0) { 789 struct fib_nh_common *nhc; 790 791 fib_select_path(net, &res, fl4, skb); 792 nhc = FIB_RES_NHC(res); 793 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 794 0, false, 795 jiffies + ip_rt_gc_timeout); 796 } 797 if (kill_route) 798 rt->dst.obsolete = DST_OBSOLETE_KILL; 799 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 800 } 801 neigh_release(n); 802 } 803 return; 804 805 reject_redirect: 806 #ifdef CONFIG_IP_ROUTE_VERBOSE 807 if (IN_DEV_LOG_MARTIANS(in_dev)) { 808 const struct iphdr *iph = (const struct iphdr *) skb->data; 809 __be32 daddr = iph->daddr; 810 __be32 saddr = iph->saddr; 811 812 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 813 " Advised path = %pI4 -> %pI4\n", 814 &old_gw, dev->name, &new_gw, 815 &saddr, &daddr); 816 } 817 #endif 818 ; 819 } 820 821 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 822 { 823 struct rtable *rt; 824 struct flowi4 fl4; 825 const struct iphdr *iph = (const struct iphdr *) skb->data; 826 struct net *net = dev_net(skb->dev); 827 int oif = skb->dev->ifindex; 828 u8 tos = RT_TOS(iph->tos); 829 u8 prot = iph->protocol; 830 u32 mark = skb->mark; 831 832 rt = (struct rtable *) dst; 833 834 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 835 ip_rt_fix_tos(&fl4); 836 __ip_do_redirect(rt, skb, &fl4, true); 837 } 838 839 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 840 { 841 struct rtable *rt = (struct rtable *)dst; 842 struct dst_entry *ret = dst; 843 844 if (rt) { 845 if (dst->obsolete > 0) { 846 ip_rt_put(rt); 847 ret = NULL; 848 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 849 rt->dst.expires) { 850 ip_rt_put(rt); 851 ret = NULL; 852 } 853 } 854 return ret; 855 } 856 857 /* 858 * Algorithm: 859 * 1. The first ip_rt_redirect_number redirects are sent 860 * with exponential backoff, then we stop sending them at all, 861 * assuming that the host ignores our redirects. 862 * 2. If we did not see packets requiring redirects 863 * during ip_rt_redirect_silence, we assume that the host 864 * forgot redirected route and start to send redirects again. 865 * 866 * This algorithm is much cheaper and more intelligent than dumb load limiting 867 * in icmp.c. 868 * 869 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 870 * and "frag. need" (breaks PMTU discovery) in icmp.c. 871 */ 872 873 void ip_rt_send_redirect(struct sk_buff *skb) 874 { 875 struct rtable *rt = skb_rtable(skb); 876 struct in_device *in_dev; 877 struct inet_peer *peer; 878 struct net *net; 879 int log_martians; 880 int vif; 881 882 rcu_read_lock(); 883 in_dev = __in_dev_get_rcu(rt->dst.dev); 884 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 885 rcu_read_unlock(); 886 return; 887 } 888 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 889 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 890 rcu_read_unlock(); 891 892 net = dev_net(rt->dst.dev); 893 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 894 if (!peer) { 895 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 896 rt_nexthop(rt, ip_hdr(skb)->daddr)); 897 return; 898 } 899 900 /* No redirected packets during ip_rt_redirect_silence; 901 * reset the algorithm. 902 */ 903 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 904 peer->rate_tokens = 0; 905 peer->n_redirects = 0; 906 } 907 908 /* Too many ignored redirects; do not send anything 909 * set dst.rate_last to the last seen redirected packet. 910 */ 911 if (peer->n_redirects >= ip_rt_redirect_number) { 912 peer->rate_last = jiffies; 913 goto out_put_peer; 914 } 915 916 /* Check for load limit; set rate_last to the latest sent 917 * redirect. 918 */ 919 if (peer->n_redirects == 0 || 920 time_after(jiffies, 921 (peer->rate_last + 922 (ip_rt_redirect_load << peer->n_redirects)))) { 923 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 924 925 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 926 peer->rate_last = jiffies; 927 ++peer->n_redirects; 928 #ifdef CONFIG_IP_ROUTE_VERBOSE 929 if (log_martians && 930 peer->n_redirects == ip_rt_redirect_number) 931 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 932 &ip_hdr(skb)->saddr, inet_iif(skb), 933 &ip_hdr(skb)->daddr, &gw); 934 #endif 935 } 936 out_put_peer: 937 inet_putpeer(peer); 938 } 939 940 static int ip_error(struct sk_buff *skb) 941 { 942 struct rtable *rt = skb_rtable(skb); 943 struct net_device *dev = skb->dev; 944 struct in_device *in_dev; 945 struct inet_peer *peer; 946 unsigned long now; 947 struct net *net; 948 bool send; 949 int code; 950 951 if (netif_is_l3_master(skb->dev)) { 952 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 953 if (!dev) 954 goto out; 955 } 956 957 in_dev = __in_dev_get_rcu(dev); 958 959 /* IP on this device is disabled. */ 960 if (!in_dev) 961 goto out; 962 963 net = dev_net(rt->dst.dev); 964 if (!IN_DEV_FORWARD(in_dev)) { 965 switch (rt->dst.error) { 966 case EHOSTUNREACH: 967 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 968 break; 969 970 case ENETUNREACH: 971 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 972 break; 973 } 974 goto out; 975 } 976 977 switch (rt->dst.error) { 978 case EINVAL: 979 default: 980 goto out; 981 case EHOSTUNREACH: 982 code = ICMP_HOST_UNREACH; 983 break; 984 case ENETUNREACH: 985 code = ICMP_NET_UNREACH; 986 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 987 break; 988 case EACCES: 989 code = ICMP_PKT_FILTERED; 990 break; 991 } 992 993 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 994 l3mdev_master_ifindex(skb->dev), 1); 995 996 send = true; 997 if (peer) { 998 now = jiffies; 999 peer->rate_tokens += now - peer->rate_last; 1000 if (peer->rate_tokens > ip_rt_error_burst) 1001 peer->rate_tokens = ip_rt_error_burst; 1002 peer->rate_last = now; 1003 if (peer->rate_tokens >= ip_rt_error_cost) 1004 peer->rate_tokens -= ip_rt_error_cost; 1005 else 1006 send = false; 1007 inet_putpeer(peer); 1008 } 1009 if (send) 1010 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1011 1012 out: kfree_skb(skb); 1013 return 0; 1014 } 1015 1016 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1017 { 1018 struct dst_entry *dst = &rt->dst; 1019 struct net *net = dev_net(dst->dev); 1020 struct fib_result res; 1021 bool lock = false; 1022 u32 old_mtu; 1023 1024 if (ip_mtu_locked(dst)) 1025 return; 1026 1027 old_mtu = ipv4_mtu(dst); 1028 if (old_mtu < mtu) 1029 return; 1030 1031 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1032 lock = true; 1033 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1034 } 1035 1036 if (rt->rt_pmtu == mtu && !lock && 1037 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1038 return; 1039 1040 rcu_read_lock(); 1041 if (fib_lookup(net, fl4, &res, 0) == 0) { 1042 struct fib_nh_common *nhc; 1043 1044 fib_select_path(net, &res, fl4, NULL); 1045 nhc = FIB_RES_NHC(res); 1046 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1047 jiffies + net->ipv4.ip_rt_mtu_expires); 1048 } 1049 rcu_read_unlock(); 1050 } 1051 1052 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1053 struct sk_buff *skb, u32 mtu, 1054 bool confirm_neigh) 1055 { 1056 struct rtable *rt = (struct rtable *) dst; 1057 struct flowi4 fl4; 1058 1059 ip_rt_build_flow_key(&fl4, sk, skb); 1060 ip_rt_fix_tos(&fl4); 1061 1062 /* Don't make lookup fail for bridged encapsulations */ 1063 if (skb && netif_is_any_bridge_port(skb->dev)) 1064 fl4.flowi4_oif = 0; 1065 1066 __ip_rt_update_pmtu(rt, &fl4, mtu); 1067 } 1068 1069 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1070 int oif, u8 protocol) 1071 { 1072 const struct iphdr *iph = (const struct iphdr *)skb->data; 1073 struct flowi4 fl4; 1074 struct rtable *rt; 1075 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1076 1077 __build_flow_key(net, &fl4, NULL, iph, oif, 1078 RT_TOS(iph->tos), protocol, mark, 0); 1079 rt = __ip_route_output_key(net, &fl4); 1080 if (!IS_ERR(rt)) { 1081 __ip_rt_update_pmtu(rt, &fl4, mtu); 1082 ip_rt_put(rt); 1083 } 1084 } 1085 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1086 1087 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1088 { 1089 const struct iphdr *iph = (const struct iphdr *)skb->data; 1090 struct flowi4 fl4; 1091 struct rtable *rt; 1092 1093 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1094 1095 if (!fl4.flowi4_mark) 1096 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1097 1098 rt = __ip_route_output_key(sock_net(sk), &fl4); 1099 if (!IS_ERR(rt)) { 1100 __ip_rt_update_pmtu(rt, &fl4, mtu); 1101 ip_rt_put(rt); 1102 } 1103 } 1104 1105 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1106 { 1107 const struct iphdr *iph = (const struct iphdr *)skb->data; 1108 struct flowi4 fl4; 1109 struct rtable *rt; 1110 struct dst_entry *odst = NULL; 1111 bool new = false; 1112 struct net *net = sock_net(sk); 1113 1114 bh_lock_sock(sk); 1115 1116 if (!ip_sk_accept_pmtu(sk)) 1117 goto out; 1118 1119 odst = sk_dst_get(sk); 1120 1121 if (sock_owned_by_user(sk) || !odst) { 1122 __ipv4_sk_update_pmtu(skb, sk, mtu); 1123 goto out; 1124 } 1125 1126 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1127 1128 rt = (struct rtable *)odst; 1129 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1130 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1131 if (IS_ERR(rt)) 1132 goto out; 1133 1134 new = true; 1135 } else { 1136 ip_rt_fix_tos(&fl4); 1137 } 1138 1139 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1140 1141 if (!dst_check(&rt->dst, 0)) { 1142 if (new) 1143 dst_release(&rt->dst); 1144 1145 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1146 if (IS_ERR(rt)) 1147 goto out; 1148 1149 new = true; 1150 } 1151 1152 if (new) 1153 sk_dst_set(sk, &rt->dst); 1154 1155 out: 1156 bh_unlock_sock(sk); 1157 dst_release(odst); 1158 } 1159 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1160 1161 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1162 int oif, u8 protocol) 1163 { 1164 const struct iphdr *iph = (const struct iphdr *)skb->data; 1165 struct flowi4 fl4; 1166 struct rtable *rt; 1167 1168 __build_flow_key(net, &fl4, NULL, iph, oif, 1169 RT_TOS(iph->tos), protocol, 0, 0); 1170 rt = __ip_route_output_key(net, &fl4); 1171 if (!IS_ERR(rt)) { 1172 __ip_do_redirect(rt, skb, &fl4, false); 1173 ip_rt_put(rt); 1174 } 1175 } 1176 EXPORT_SYMBOL_GPL(ipv4_redirect); 1177 1178 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1179 { 1180 const struct iphdr *iph = (const struct iphdr *)skb->data; 1181 struct flowi4 fl4; 1182 struct rtable *rt; 1183 struct net *net = sock_net(sk); 1184 1185 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1186 rt = __ip_route_output_key(net, &fl4); 1187 if (!IS_ERR(rt)) { 1188 __ip_do_redirect(rt, skb, &fl4, false); 1189 ip_rt_put(rt); 1190 } 1191 } 1192 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1193 1194 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1195 u32 cookie) 1196 { 1197 struct rtable *rt = (struct rtable *) dst; 1198 1199 /* All IPV4 dsts are created with ->obsolete set to the value 1200 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1201 * into this function always. 1202 * 1203 * When a PMTU/redirect information update invalidates a route, 1204 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1205 * DST_OBSOLETE_DEAD. 1206 */ 1207 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1208 return NULL; 1209 return dst; 1210 } 1211 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1212 1213 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1214 { 1215 struct ip_options opt; 1216 int res; 1217 1218 /* Recompile ip options since IPCB may not be valid anymore. 1219 * Also check we have a reasonable ipv4 header. 1220 */ 1221 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1222 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1223 return; 1224 1225 memset(&opt, 0, sizeof(opt)); 1226 if (ip_hdr(skb)->ihl > 5) { 1227 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1228 return; 1229 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1230 1231 rcu_read_lock(); 1232 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1233 rcu_read_unlock(); 1234 1235 if (res) 1236 return; 1237 } 1238 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1239 } 1240 1241 static void ipv4_link_failure(struct sk_buff *skb) 1242 { 1243 struct rtable *rt; 1244 1245 ipv4_send_dest_unreach(skb); 1246 1247 rt = skb_rtable(skb); 1248 if (rt) 1249 dst_set_expires(&rt->dst, 0); 1250 } 1251 1252 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1253 { 1254 pr_debug("%s: %pI4 -> %pI4, %s\n", 1255 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1256 skb->dev ? skb->dev->name : "?"); 1257 kfree_skb(skb); 1258 WARN_ON(1); 1259 return 0; 1260 } 1261 1262 /* 1263 * We do not cache source address of outgoing interface, 1264 * because it is used only by IP RR, TS and SRR options, 1265 * so that it out of fast path. 1266 * 1267 * BTW remember: "addr" is allowed to be not aligned 1268 * in IP options! 1269 */ 1270 1271 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1272 { 1273 __be32 src; 1274 1275 if (rt_is_output_route(rt)) 1276 src = ip_hdr(skb)->saddr; 1277 else { 1278 struct fib_result res; 1279 struct iphdr *iph = ip_hdr(skb); 1280 struct flowi4 fl4 = { 1281 .daddr = iph->daddr, 1282 .saddr = iph->saddr, 1283 .flowi4_tos = RT_TOS(iph->tos), 1284 .flowi4_oif = rt->dst.dev->ifindex, 1285 .flowi4_iif = skb->dev->ifindex, 1286 .flowi4_mark = skb->mark, 1287 }; 1288 1289 rcu_read_lock(); 1290 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1291 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1292 else 1293 src = inet_select_addr(rt->dst.dev, 1294 rt_nexthop(rt, iph->daddr), 1295 RT_SCOPE_UNIVERSE); 1296 rcu_read_unlock(); 1297 } 1298 memcpy(addr, &src, 4); 1299 } 1300 1301 #ifdef CONFIG_IP_ROUTE_CLASSID 1302 static void set_class_tag(struct rtable *rt, u32 tag) 1303 { 1304 if (!(rt->dst.tclassid & 0xFFFF)) 1305 rt->dst.tclassid |= tag & 0xFFFF; 1306 if (!(rt->dst.tclassid & 0xFFFF0000)) 1307 rt->dst.tclassid |= tag & 0xFFFF0000; 1308 } 1309 #endif 1310 1311 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1312 { 1313 struct net *net = dev_net(dst->dev); 1314 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1315 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1316 net->ipv4.ip_rt_min_advmss); 1317 1318 return min(advmss, IPV4_MAX_PMTU - header_size); 1319 } 1320 1321 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1322 { 1323 return ip_dst_mtu_maybe_forward(dst, false); 1324 } 1325 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1326 1327 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1328 { 1329 struct fnhe_hash_bucket *hash; 1330 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1331 u32 hval = fnhe_hashfun(daddr); 1332 1333 spin_lock_bh(&fnhe_lock); 1334 1335 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1336 lockdep_is_held(&fnhe_lock)); 1337 hash += hval; 1338 1339 fnhe_p = &hash->chain; 1340 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1341 while (fnhe) { 1342 if (fnhe->fnhe_daddr == daddr) { 1343 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1344 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1345 /* set fnhe_daddr to 0 to ensure it won't bind with 1346 * new dsts in rt_bind_exception(). 1347 */ 1348 fnhe->fnhe_daddr = 0; 1349 fnhe_flush_routes(fnhe); 1350 kfree_rcu(fnhe, rcu); 1351 break; 1352 } 1353 fnhe_p = &fnhe->fnhe_next; 1354 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1355 lockdep_is_held(&fnhe_lock)); 1356 } 1357 1358 spin_unlock_bh(&fnhe_lock); 1359 } 1360 1361 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1362 __be32 daddr) 1363 { 1364 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1365 struct fib_nh_exception *fnhe; 1366 u32 hval; 1367 1368 if (!hash) 1369 return NULL; 1370 1371 hval = fnhe_hashfun(daddr); 1372 1373 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1374 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1375 if (fnhe->fnhe_daddr == daddr) { 1376 if (fnhe->fnhe_expires && 1377 time_after(jiffies, fnhe->fnhe_expires)) { 1378 ip_del_fnhe(nhc, daddr); 1379 break; 1380 } 1381 return fnhe; 1382 } 1383 } 1384 return NULL; 1385 } 1386 1387 /* MTU selection: 1388 * 1. mtu on route is locked - use it 1389 * 2. mtu from nexthop exception 1390 * 3. mtu from egress device 1391 */ 1392 1393 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1394 { 1395 struct fib_nh_common *nhc = res->nhc; 1396 struct net_device *dev = nhc->nhc_dev; 1397 struct fib_info *fi = res->fi; 1398 u32 mtu = 0; 1399 1400 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1401 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1402 mtu = fi->fib_mtu; 1403 1404 if (likely(!mtu)) { 1405 struct fib_nh_exception *fnhe; 1406 1407 fnhe = find_exception(nhc, daddr); 1408 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1409 mtu = fnhe->fnhe_pmtu; 1410 } 1411 1412 if (likely(!mtu)) 1413 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1414 1415 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1416 } 1417 1418 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1419 __be32 daddr, const bool do_cache) 1420 { 1421 bool ret = false; 1422 1423 spin_lock_bh(&fnhe_lock); 1424 1425 if (daddr == fnhe->fnhe_daddr) { 1426 struct rtable __rcu **porig; 1427 struct rtable *orig; 1428 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1429 1430 if (rt_is_input_route(rt)) 1431 porig = &fnhe->fnhe_rth_input; 1432 else 1433 porig = &fnhe->fnhe_rth_output; 1434 orig = rcu_dereference(*porig); 1435 1436 if (fnhe->fnhe_genid != genid) { 1437 fnhe->fnhe_genid = genid; 1438 fnhe->fnhe_gw = 0; 1439 fnhe->fnhe_pmtu = 0; 1440 fnhe->fnhe_expires = 0; 1441 fnhe->fnhe_mtu_locked = false; 1442 fnhe_flush_routes(fnhe); 1443 orig = NULL; 1444 } 1445 fill_route_from_fnhe(rt, fnhe); 1446 if (!rt->rt_gw4) { 1447 rt->rt_gw4 = daddr; 1448 rt->rt_gw_family = AF_INET; 1449 } 1450 1451 if (do_cache) { 1452 dst_hold(&rt->dst); 1453 rcu_assign_pointer(*porig, rt); 1454 if (orig) { 1455 dst_dev_put(&orig->dst); 1456 dst_release(&orig->dst); 1457 } 1458 ret = true; 1459 } 1460 1461 fnhe->fnhe_stamp = jiffies; 1462 } 1463 spin_unlock_bh(&fnhe_lock); 1464 1465 return ret; 1466 } 1467 1468 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1469 { 1470 struct rtable *orig, *prev, **p; 1471 bool ret = true; 1472 1473 if (rt_is_input_route(rt)) { 1474 p = (struct rtable **)&nhc->nhc_rth_input; 1475 } else { 1476 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1477 } 1478 orig = *p; 1479 1480 /* hold dst before doing cmpxchg() to avoid race condition 1481 * on this dst 1482 */ 1483 dst_hold(&rt->dst); 1484 prev = cmpxchg(p, orig, rt); 1485 if (prev == orig) { 1486 if (orig) { 1487 rt_add_uncached_list(orig); 1488 dst_release(&orig->dst); 1489 } 1490 } else { 1491 dst_release(&rt->dst); 1492 ret = false; 1493 } 1494 1495 return ret; 1496 } 1497 1498 struct uncached_list { 1499 spinlock_t lock; 1500 struct list_head head; 1501 struct list_head quarantine; 1502 }; 1503 1504 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1505 1506 void rt_add_uncached_list(struct rtable *rt) 1507 { 1508 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1509 1510 rt->rt_uncached_list = ul; 1511 1512 spin_lock_bh(&ul->lock); 1513 list_add_tail(&rt->rt_uncached, &ul->head); 1514 spin_unlock_bh(&ul->lock); 1515 } 1516 1517 void rt_del_uncached_list(struct rtable *rt) 1518 { 1519 if (!list_empty(&rt->rt_uncached)) { 1520 struct uncached_list *ul = rt->rt_uncached_list; 1521 1522 spin_lock_bh(&ul->lock); 1523 list_del_init(&rt->rt_uncached); 1524 spin_unlock_bh(&ul->lock); 1525 } 1526 } 1527 1528 static void ipv4_dst_destroy(struct dst_entry *dst) 1529 { 1530 struct rtable *rt = (struct rtable *)dst; 1531 1532 ip_dst_metrics_put(dst); 1533 rt_del_uncached_list(rt); 1534 } 1535 1536 void rt_flush_dev(struct net_device *dev) 1537 { 1538 struct rtable *rt, *safe; 1539 int cpu; 1540 1541 for_each_possible_cpu(cpu) { 1542 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1543 1544 if (list_empty(&ul->head)) 1545 continue; 1546 1547 spin_lock_bh(&ul->lock); 1548 list_for_each_entry_safe(rt, safe, &ul->head, rt_uncached) { 1549 if (rt->dst.dev != dev) 1550 continue; 1551 rt->dst.dev = blackhole_netdev; 1552 dev_replace_track(dev, blackhole_netdev, 1553 &rt->dst.dev_tracker, 1554 GFP_ATOMIC); 1555 list_move(&rt->rt_uncached, &ul->quarantine); 1556 } 1557 spin_unlock_bh(&ul->lock); 1558 } 1559 } 1560 1561 static bool rt_cache_valid(const struct rtable *rt) 1562 { 1563 return rt && 1564 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1565 !rt_is_expired(rt); 1566 } 1567 1568 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1569 const struct fib_result *res, 1570 struct fib_nh_exception *fnhe, 1571 struct fib_info *fi, u16 type, u32 itag, 1572 const bool do_cache) 1573 { 1574 bool cached = false; 1575 1576 if (fi) { 1577 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1578 1579 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1580 rt->rt_uses_gateway = 1; 1581 rt->rt_gw_family = nhc->nhc_gw_family; 1582 /* only INET and INET6 are supported */ 1583 if (likely(nhc->nhc_gw_family == AF_INET)) 1584 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1585 else 1586 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1587 } 1588 1589 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1590 1591 #ifdef CONFIG_IP_ROUTE_CLASSID 1592 if (nhc->nhc_family == AF_INET) { 1593 struct fib_nh *nh; 1594 1595 nh = container_of(nhc, struct fib_nh, nh_common); 1596 rt->dst.tclassid = nh->nh_tclassid; 1597 } 1598 #endif 1599 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1600 if (unlikely(fnhe)) 1601 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1602 else if (do_cache) 1603 cached = rt_cache_route(nhc, rt); 1604 if (unlikely(!cached)) { 1605 /* Routes we intend to cache in nexthop exception or 1606 * FIB nexthop have the DST_NOCACHE bit clear. 1607 * However, if we are unsuccessful at storing this 1608 * route into the cache we really need to set it. 1609 */ 1610 if (!rt->rt_gw4) { 1611 rt->rt_gw_family = AF_INET; 1612 rt->rt_gw4 = daddr; 1613 } 1614 rt_add_uncached_list(rt); 1615 } 1616 } else 1617 rt_add_uncached_list(rt); 1618 1619 #ifdef CONFIG_IP_ROUTE_CLASSID 1620 #ifdef CONFIG_IP_MULTIPLE_TABLES 1621 set_class_tag(rt, res->tclassid); 1622 #endif 1623 set_class_tag(rt, itag); 1624 #endif 1625 } 1626 1627 struct rtable *rt_dst_alloc(struct net_device *dev, 1628 unsigned int flags, u16 type, 1629 bool nopolicy, bool noxfrm) 1630 { 1631 struct rtable *rt; 1632 1633 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1634 (nopolicy ? DST_NOPOLICY : 0) | 1635 (noxfrm ? DST_NOXFRM : 0)); 1636 1637 if (rt) { 1638 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1639 rt->rt_flags = flags; 1640 rt->rt_type = type; 1641 rt->rt_is_input = 0; 1642 rt->rt_iif = 0; 1643 rt->rt_pmtu = 0; 1644 rt->rt_mtu_locked = 0; 1645 rt->rt_uses_gateway = 0; 1646 rt->rt_gw_family = 0; 1647 rt->rt_gw4 = 0; 1648 INIT_LIST_HEAD(&rt->rt_uncached); 1649 1650 rt->dst.output = ip_output; 1651 if (flags & RTCF_LOCAL) 1652 rt->dst.input = ip_local_deliver; 1653 } 1654 1655 return rt; 1656 } 1657 EXPORT_SYMBOL(rt_dst_alloc); 1658 1659 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1660 { 1661 struct rtable *new_rt; 1662 1663 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1664 rt->dst.flags); 1665 1666 if (new_rt) { 1667 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1668 new_rt->rt_flags = rt->rt_flags; 1669 new_rt->rt_type = rt->rt_type; 1670 new_rt->rt_is_input = rt->rt_is_input; 1671 new_rt->rt_iif = rt->rt_iif; 1672 new_rt->rt_pmtu = rt->rt_pmtu; 1673 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1674 new_rt->rt_gw_family = rt->rt_gw_family; 1675 if (rt->rt_gw_family == AF_INET) 1676 new_rt->rt_gw4 = rt->rt_gw4; 1677 else if (rt->rt_gw_family == AF_INET6) 1678 new_rt->rt_gw6 = rt->rt_gw6; 1679 INIT_LIST_HEAD(&new_rt->rt_uncached); 1680 1681 new_rt->dst.input = rt->dst.input; 1682 new_rt->dst.output = rt->dst.output; 1683 new_rt->dst.error = rt->dst.error; 1684 new_rt->dst.lastuse = jiffies; 1685 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1686 } 1687 return new_rt; 1688 } 1689 EXPORT_SYMBOL(rt_dst_clone); 1690 1691 /* called in rcu_read_lock() section */ 1692 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1693 u8 tos, struct net_device *dev, 1694 struct in_device *in_dev, u32 *itag) 1695 { 1696 int err; 1697 1698 /* Primary sanity checks. */ 1699 if (!in_dev) 1700 return -EINVAL; 1701 1702 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1703 skb->protocol != htons(ETH_P_IP)) 1704 return -EINVAL; 1705 1706 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1707 return -EINVAL; 1708 1709 if (ipv4_is_zeronet(saddr)) { 1710 if (!ipv4_is_local_multicast(daddr) && 1711 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1712 return -EINVAL; 1713 } else { 1714 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1715 in_dev, itag); 1716 if (err < 0) 1717 return err; 1718 } 1719 return 0; 1720 } 1721 1722 /* called in rcu_read_lock() section */ 1723 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1724 u8 tos, struct net_device *dev, int our) 1725 { 1726 struct in_device *in_dev = __in_dev_get_rcu(dev); 1727 unsigned int flags = RTCF_MULTICAST; 1728 struct rtable *rth; 1729 bool no_policy; 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 no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); 1741 if (no_policy) 1742 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1743 1744 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1745 no_policy, false); 1746 if (!rth) 1747 return -ENOBUFS; 1748 1749 #ifdef CONFIG_IP_ROUTE_CLASSID 1750 rth->dst.tclassid = itag; 1751 #endif 1752 rth->dst.output = ip_rt_bug; 1753 rth->rt_is_input= 1; 1754 1755 #ifdef CONFIG_IP_MROUTE 1756 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1757 rth->dst.input = ip_mr_input; 1758 #endif 1759 RT_CACHE_STAT_INC(in_slow_mc); 1760 1761 skb_dst_drop(skb); 1762 skb_dst_set(skb, &rth->dst); 1763 return 0; 1764 } 1765 1766 1767 static void ip_handle_martian_source(struct net_device *dev, 1768 struct in_device *in_dev, 1769 struct sk_buff *skb, 1770 __be32 daddr, 1771 __be32 saddr) 1772 { 1773 RT_CACHE_STAT_INC(in_martian_src); 1774 #ifdef CONFIG_IP_ROUTE_VERBOSE 1775 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1776 /* 1777 * RFC1812 recommendation, if source is martian, 1778 * the only hint is MAC header. 1779 */ 1780 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1781 &daddr, &saddr, dev->name); 1782 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1783 print_hex_dump(KERN_WARNING, "ll header: ", 1784 DUMP_PREFIX_OFFSET, 16, 1, 1785 skb_mac_header(skb), 1786 dev->hard_header_len, false); 1787 } 1788 } 1789 #endif 1790 } 1791 1792 /* called in rcu_read_lock() section */ 1793 static int __mkroute_input(struct sk_buff *skb, 1794 const struct fib_result *res, 1795 struct in_device *in_dev, 1796 __be32 daddr, __be32 saddr, u32 tos) 1797 { 1798 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1799 struct net_device *dev = nhc->nhc_dev; 1800 struct fib_nh_exception *fnhe; 1801 struct rtable *rth; 1802 int err; 1803 struct in_device *out_dev; 1804 bool do_cache, no_policy; 1805 u32 itag = 0; 1806 1807 /* get a working reference to the output device */ 1808 out_dev = __in_dev_get_rcu(dev); 1809 if (!out_dev) { 1810 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1811 return -EINVAL; 1812 } 1813 1814 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1815 in_dev->dev, in_dev, &itag); 1816 if (err < 0) { 1817 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1818 saddr); 1819 1820 goto cleanup; 1821 } 1822 1823 do_cache = res->fi && !itag; 1824 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1825 skb->protocol == htons(ETH_P_IP)) { 1826 __be32 gw; 1827 1828 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1829 if (IN_DEV_SHARED_MEDIA(out_dev) || 1830 inet_addr_onlink(out_dev, saddr, gw)) 1831 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1832 } 1833 1834 if (skb->protocol != htons(ETH_P_IP)) { 1835 /* Not IP (i.e. ARP). Do not create route, if it is 1836 * invalid for proxy arp. DNAT routes are always valid. 1837 * 1838 * Proxy arp feature have been extended to allow, ARP 1839 * replies back to the same interface, to support 1840 * Private VLAN switch technologies. See arp.c. 1841 */ 1842 if (out_dev == in_dev && 1843 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1844 err = -EINVAL; 1845 goto cleanup; 1846 } 1847 } 1848 1849 no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); 1850 if (no_policy) 1851 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1852 1853 fnhe = find_exception(nhc, daddr); 1854 if (do_cache) { 1855 if (fnhe) 1856 rth = rcu_dereference(fnhe->fnhe_rth_input); 1857 else 1858 rth = rcu_dereference(nhc->nhc_rth_input); 1859 if (rt_cache_valid(rth)) { 1860 skb_dst_set_noref(skb, &rth->dst); 1861 goto out; 1862 } 1863 } 1864 1865 rth = rt_dst_alloc(out_dev->dev, 0, res->type, no_policy, 1866 IN_DEV_ORCONF(out_dev, NOXFRM)); 1867 if (!rth) { 1868 err = -ENOBUFS; 1869 goto cleanup; 1870 } 1871 1872 rth->rt_is_input = 1; 1873 RT_CACHE_STAT_INC(in_slow_tot); 1874 1875 rth->dst.input = ip_forward; 1876 1877 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1878 do_cache); 1879 lwtunnel_set_redirect(&rth->dst); 1880 skb_dst_set(skb, &rth->dst); 1881 out: 1882 err = 0; 1883 cleanup: 1884 return err; 1885 } 1886 1887 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1888 /* To make ICMP packets follow the right flow, the multipath hash is 1889 * calculated from the inner IP addresses. 1890 */ 1891 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1892 struct flow_keys *hash_keys) 1893 { 1894 const struct iphdr *outer_iph = ip_hdr(skb); 1895 const struct iphdr *key_iph = outer_iph; 1896 const struct iphdr *inner_iph; 1897 const struct icmphdr *icmph; 1898 struct iphdr _inner_iph; 1899 struct icmphdr _icmph; 1900 1901 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1902 goto out; 1903 1904 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1905 goto out; 1906 1907 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1908 &_icmph); 1909 if (!icmph) 1910 goto out; 1911 1912 if (!icmp_is_err(icmph->type)) 1913 goto out; 1914 1915 inner_iph = skb_header_pointer(skb, 1916 outer_iph->ihl * 4 + sizeof(_icmph), 1917 sizeof(_inner_iph), &_inner_iph); 1918 if (!inner_iph) 1919 goto out; 1920 1921 key_iph = inner_iph; 1922 out: 1923 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1924 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1925 } 1926 1927 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1928 const struct sk_buff *skb, 1929 bool *p_has_inner) 1930 { 1931 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1932 struct flow_keys keys, hash_keys; 1933 1934 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1935 return 0; 1936 1937 memset(&hash_keys, 0, sizeof(hash_keys)); 1938 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1939 1940 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1941 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1942 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1943 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1944 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1945 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1946 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1947 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1948 hash_keys.ports.src = keys.ports.src; 1949 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1950 hash_keys.ports.dst = keys.ports.dst; 1951 1952 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1953 return flow_hash_from_keys(&hash_keys); 1954 } 1955 1956 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1957 const struct sk_buff *skb, 1958 bool has_inner) 1959 { 1960 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1961 struct flow_keys keys, hash_keys; 1962 1963 /* We assume the packet carries an encapsulation, but if none was 1964 * encountered during dissection of the outer flow, then there is no 1965 * point in calling the flow dissector again. 1966 */ 1967 if (!has_inner) 1968 return 0; 1969 1970 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1971 return 0; 1972 1973 memset(&hash_keys, 0, sizeof(hash_keys)); 1974 skb_flow_dissect_flow_keys(skb, &keys, 0); 1975 1976 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1977 return 0; 1978 1979 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1980 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1981 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1982 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1983 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1984 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1985 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1986 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1988 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1989 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1990 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1991 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1992 hash_keys.tags.flow_label = keys.tags.flow_label; 1993 } 1994 1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1996 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1998 hash_keys.ports.src = keys.ports.src; 1999 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2000 hash_keys.ports.dst = keys.ports.dst; 2001 2002 return flow_hash_from_keys(&hash_keys); 2003 } 2004 2005 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2006 const struct sk_buff *skb) 2007 { 2008 u32 mhash, mhash_inner; 2009 bool has_inner = true; 2010 2011 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2012 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2013 2014 return jhash_2words(mhash, mhash_inner, 0); 2015 } 2016 2017 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2018 const struct flowi4 *fl4) 2019 { 2020 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 2021 struct flow_keys hash_keys; 2022 2023 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2024 return 0; 2025 2026 memset(&hash_keys, 0, sizeof(hash_keys)); 2027 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2028 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2029 hash_keys.addrs.v4addrs.src = fl4->saddr; 2030 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2031 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2032 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2033 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2034 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2035 hash_keys.ports.src = fl4->fl4_sport; 2036 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2037 hash_keys.ports.dst = fl4->fl4_dport; 2038 2039 return flow_hash_from_keys(&hash_keys); 2040 } 2041 2042 /* if skb is set it will be used and fl4 can be NULL */ 2043 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2044 const struct sk_buff *skb, struct flow_keys *flkeys) 2045 { 2046 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2047 struct flow_keys hash_keys; 2048 u32 mhash = 0; 2049 2050 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2051 case 0: 2052 memset(&hash_keys, 0, sizeof(hash_keys)); 2053 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2054 if (skb) { 2055 ip_multipath_l3_keys(skb, &hash_keys); 2056 } else { 2057 hash_keys.addrs.v4addrs.src = fl4->saddr; 2058 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2059 } 2060 mhash = flow_hash_from_keys(&hash_keys); 2061 break; 2062 case 1: 2063 /* skb is currently provided only when forwarding */ 2064 if (skb) { 2065 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2066 struct flow_keys keys; 2067 2068 /* short-circuit if we already have L4 hash present */ 2069 if (skb->l4_hash) 2070 return skb_get_hash_raw(skb) >> 1; 2071 2072 memset(&hash_keys, 0, sizeof(hash_keys)); 2073 2074 if (!flkeys) { 2075 skb_flow_dissect_flow_keys(skb, &keys, flag); 2076 flkeys = &keys; 2077 } 2078 2079 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2080 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2081 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2082 hash_keys.ports.src = flkeys->ports.src; 2083 hash_keys.ports.dst = flkeys->ports.dst; 2084 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2085 } else { 2086 memset(&hash_keys, 0, sizeof(hash_keys)); 2087 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2088 hash_keys.addrs.v4addrs.src = fl4->saddr; 2089 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2090 hash_keys.ports.src = fl4->fl4_sport; 2091 hash_keys.ports.dst = fl4->fl4_dport; 2092 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2093 } 2094 mhash = flow_hash_from_keys(&hash_keys); 2095 break; 2096 case 2: 2097 memset(&hash_keys, 0, sizeof(hash_keys)); 2098 /* skb is currently provided only when forwarding */ 2099 if (skb) { 2100 struct flow_keys keys; 2101 2102 skb_flow_dissect_flow_keys(skb, &keys, 0); 2103 /* Inner can be v4 or v6 */ 2104 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2105 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2106 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2107 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2108 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2109 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2110 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2111 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2112 hash_keys.tags.flow_label = keys.tags.flow_label; 2113 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2114 } else { 2115 /* Same as case 0 */ 2116 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2117 ip_multipath_l3_keys(skb, &hash_keys); 2118 } 2119 } else { 2120 /* Same as case 0 */ 2121 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2122 hash_keys.addrs.v4addrs.src = fl4->saddr; 2123 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2124 } 2125 mhash = flow_hash_from_keys(&hash_keys); 2126 break; 2127 case 3: 2128 if (skb) 2129 mhash = fib_multipath_custom_hash_skb(net, skb); 2130 else 2131 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2132 break; 2133 } 2134 2135 if (multipath_hash) 2136 mhash = jhash_2words(mhash, multipath_hash, 0); 2137 2138 return mhash >> 1; 2139 } 2140 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2141 2142 static int ip_mkroute_input(struct sk_buff *skb, 2143 struct fib_result *res, 2144 struct in_device *in_dev, 2145 __be32 daddr, __be32 saddr, u32 tos, 2146 struct flow_keys *hkeys) 2147 { 2148 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2149 if (res->fi && fib_info_num_path(res->fi) > 1) { 2150 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2151 2152 fib_select_multipath(res, h); 2153 } 2154 #endif 2155 2156 /* create a routing cache entry */ 2157 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2158 } 2159 2160 /* Implements all the saddr-related checks as ip_route_input_slow(), 2161 * assuming daddr is valid and the destination is not a local broadcast one. 2162 * Uses the provided hint instead of performing a route lookup. 2163 */ 2164 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2165 u8 tos, struct net_device *dev, 2166 const struct sk_buff *hint) 2167 { 2168 struct in_device *in_dev = __in_dev_get_rcu(dev); 2169 struct rtable *rt = skb_rtable(hint); 2170 struct net *net = dev_net(dev); 2171 int err = -EINVAL; 2172 u32 tag = 0; 2173 2174 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2175 goto martian_source; 2176 2177 if (ipv4_is_zeronet(saddr)) 2178 goto martian_source; 2179 2180 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2181 goto martian_source; 2182 2183 if (rt->rt_type != RTN_LOCAL) 2184 goto skip_validate_source; 2185 2186 tos &= IPTOS_RT_MASK; 2187 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2188 if (err < 0) 2189 goto martian_source; 2190 2191 skip_validate_source: 2192 skb_dst_copy(skb, hint); 2193 return 0; 2194 2195 martian_source: 2196 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2197 return err; 2198 } 2199 2200 /* get device for dst_alloc with local routes */ 2201 static struct net_device *ip_rt_get_dev(struct net *net, 2202 const struct fib_result *res) 2203 { 2204 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2205 struct net_device *dev = NULL; 2206 2207 if (nhc) 2208 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2209 2210 return dev ? : net->loopback_dev; 2211 } 2212 2213 /* 2214 * NOTE. We drop all the packets that has local source 2215 * addresses, because every properly looped back packet 2216 * must have correct destination already attached by output routine. 2217 * Changes in the enforced policies must be applied also to 2218 * ip_route_use_hint(). 2219 * 2220 * Such approach solves two big problems: 2221 * 1. Not simplex devices are handled properly. 2222 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2223 * called with rcu_read_lock() 2224 */ 2225 2226 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2227 u8 tos, struct net_device *dev, 2228 struct fib_result *res) 2229 { 2230 struct in_device *in_dev = __in_dev_get_rcu(dev); 2231 struct flow_keys *flkeys = NULL, _flkeys; 2232 struct net *net = dev_net(dev); 2233 struct ip_tunnel_info *tun_info; 2234 int err = -EINVAL; 2235 unsigned int flags = 0; 2236 u32 itag = 0; 2237 struct rtable *rth; 2238 struct flowi4 fl4; 2239 bool do_cache = true; 2240 bool no_policy; 2241 2242 /* IP on this device is disabled. */ 2243 2244 if (!in_dev) 2245 goto out; 2246 2247 /* Check for the most weird martians, which can be not detected 2248 * by fib_lookup. 2249 */ 2250 2251 tun_info = skb_tunnel_info(skb); 2252 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2253 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2254 else 2255 fl4.flowi4_tun_key.tun_id = 0; 2256 skb_dst_drop(skb); 2257 2258 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2259 goto martian_source; 2260 2261 res->fi = NULL; 2262 res->table = NULL; 2263 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2264 goto brd_input; 2265 2266 /* Accept zero addresses only to limited broadcast; 2267 * I even do not know to fix it or not. Waiting for complains :-) 2268 */ 2269 if (ipv4_is_zeronet(saddr)) 2270 goto martian_source; 2271 2272 if (ipv4_is_zeronet(daddr)) 2273 goto martian_destination; 2274 2275 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2276 * and call it once if daddr or/and saddr are loopback addresses 2277 */ 2278 if (ipv4_is_loopback(daddr)) { 2279 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2280 goto martian_destination; 2281 } else if (ipv4_is_loopback(saddr)) { 2282 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2283 goto martian_source; 2284 } 2285 2286 /* 2287 * Now we are ready to route packet. 2288 */ 2289 fl4.flowi4_l3mdev = 0; 2290 fl4.flowi4_oif = 0; 2291 fl4.flowi4_iif = dev->ifindex; 2292 fl4.flowi4_mark = skb->mark; 2293 fl4.flowi4_tos = tos; 2294 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2295 fl4.flowi4_flags = 0; 2296 fl4.daddr = daddr; 2297 fl4.saddr = saddr; 2298 fl4.flowi4_uid = sock_net_uid(net, NULL); 2299 fl4.flowi4_multipath_hash = 0; 2300 2301 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2302 flkeys = &_flkeys; 2303 } else { 2304 fl4.flowi4_proto = 0; 2305 fl4.fl4_sport = 0; 2306 fl4.fl4_dport = 0; 2307 } 2308 2309 err = fib_lookup(net, &fl4, res, 0); 2310 if (err != 0) { 2311 if (!IN_DEV_FORWARD(in_dev)) 2312 err = -EHOSTUNREACH; 2313 goto no_route; 2314 } 2315 2316 if (res->type == RTN_BROADCAST) { 2317 if (IN_DEV_BFORWARD(in_dev)) 2318 goto make_route; 2319 /* not do cache if bc_forwarding is enabled */ 2320 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2321 do_cache = false; 2322 goto brd_input; 2323 } 2324 2325 if (res->type == RTN_LOCAL) { 2326 err = fib_validate_source(skb, saddr, daddr, tos, 2327 0, dev, in_dev, &itag); 2328 if (err < 0) 2329 goto martian_source; 2330 goto local_input; 2331 } 2332 2333 if (!IN_DEV_FORWARD(in_dev)) { 2334 err = -EHOSTUNREACH; 2335 goto no_route; 2336 } 2337 if (res->type != RTN_UNICAST) 2338 goto martian_destination; 2339 2340 make_route: 2341 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2342 out: return err; 2343 2344 brd_input: 2345 if (skb->protocol != htons(ETH_P_IP)) 2346 goto e_inval; 2347 2348 if (!ipv4_is_zeronet(saddr)) { 2349 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2350 in_dev, &itag); 2351 if (err < 0) 2352 goto martian_source; 2353 } 2354 flags |= RTCF_BROADCAST; 2355 res->type = RTN_BROADCAST; 2356 RT_CACHE_STAT_INC(in_brd); 2357 2358 local_input: 2359 no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); 2360 if (no_policy) 2361 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2362 2363 do_cache &= res->fi && !itag; 2364 if (do_cache) { 2365 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2366 2367 rth = rcu_dereference(nhc->nhc_rth_input); 2368 if (rt_cache_valid(rth)) { 2369 skb_dst_set_noref(skb, &rth->dst); 2370 err = 0; 2371 goto out; 2372 } 2373 } 2374 2375 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2376 flags | RTCF_LOCAL, res->type, 2377 no_policy, false); 2378 if (!rth) 2379 goto e_nobufs; 2380 2381 rth->dst.output= ip_rt_bug; 2382 #ifdef CONFIG_IP_ROUTE_CLASSID 2383 rth->dst.tclassid = itag; 2384 #endif 2385 rth->rt_is_input = 1; 2386 2387 RT_CACHE_STAT_INC(in_slow_tot); 2388 if (res->type == RTN_UNREACHABLE) { 2389 rth->dst.input= ip_error; 2390 rth->dst.error= -err; 2391 rth->rt_flags &= ~RTCF_LOCAL; 2392 } 2393 2394 if (do_cache) { 2395 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2396 2397 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2398 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2399 WARN_ON(rth->dst.input == lwtunnel_input); 2400 rth->dst.lwtstate->orig_input = rth->dst.input; 2401 rth->dst.input = lwtunnel_input; 2402 } 2403 2404 if (unlikely(!rt_cache_route(nhc, rth))) 2405 rt_add_uncached_list(rth); 2406 } 2407 skb_dst_set(skb, &rth->dst); 2408 err = 0; 2409 goto out; 2410 2411 no_route: 2412 RT_CACHE_STAT_INC(in_no_route); 2413 res->type = RTN_UNREACHABLE; 2414 res->fi = NULL; 2415 res->table = NULL; 2416 goto local_input; 2417 2418 /* 2419 * Do not cache martian addresses: they should be logged (RFC1812) 2420 */ 2421 martian_destination: 2422 RT_CACHE_STAT_INC(in_martian_dst); 2423 #ifdef CONFIG_IP_ROUTE_VERBOSE 2424 if (IN_DEV_LOG_MARTIANS(in_dev)) 2425 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2426 &daddr, &saddr, dev->name); 2427 #endif 2428 2429 e_inval: 2430 err = -EINVAL; 2431 goto out; 2432 2433 e_nobufs: 2434 err = -ENOBUFS; 2435 goto out; 2436 2437 martian_source: 2438 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2439 goto out; 2440 } 2441 2442 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2443 u8 tos, struct net_device *dev) 2444 { 2445 struct fib_result res; 2446 int err; 2447 2448 tos &= IPTOS_RT_MASK; 2449 rcu_read_lock(); 2450 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2451 rcu_read_unlock(); 2452 2453 return err; 2454 } 2455 EXPORT_SYMBOL(ip_route_input_noref); 2456 2457 /* called with rcu_read_lock held */ 2458 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2459 u8 tos, struct net_device *dev, struct fib_result *res) 2460 { 2461 /* Multicast recognition logic is moved from route cache to here. 2462 * The problem was that too many Ethernet cards have broken/missing 2463 * hardware multicast filters :-( As result the host on multicasting 2464 * network acquires a lot of useless route cache entries, sort of 2465 * SDR messages from all the world. Now we try to get rid of them. 2466 * Really, provided software IP multicast filter is organized 2467 * reasonably (at least, hashed), it does not result in a slowdown 2468 * comparing with route cache reject entries. 2469 * Note, that multicast routers are not affected, because 2470 * route cache entry is created eventually. 2471 */ 2472 if (ipv4_is_multicast(daddr)) { 2473 struct in_device *in_dev = __in_dev_get_rcu(dev); 2474 int our = 0; 2475 int err = -EINVAL; 2476 2477 if (!in_dev) 2478 return err; 2479 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2480 ip_hdr(skb)->protocol); 2481 2482 /* check l3 master if no match yet */ 2483 if (!our && netif_is_l3_slave(dev)) { 2484 struct in_device *l3_in_dev; 2485 2486 l3_in_dev = __in_dev_get_rcu(skb->dev); 2487 if (l3_in_dev) 2488 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2489 ip_hdr(skb)->protocol); 2490 } 2491 2492 if (our 2493 #ifdef CONFIG_IP_MROUTE 2494 || 2495 (!ipv4_is_local_multicast(daddr) && 2496 IN_DEV_MFORWARD(in_dev)) 2497 #endif 2498 ) { 2499 err = ip_route_input_mc(skb, daddr, saddr, 2500 tos, dev, our); 2501 } 2502 return err; 2503 } 2504 2505 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2506 } 2507 2508 /* called with rcu_read_lock() */ 2509 static struct rtable *__mkroute_output(const struct fib_result *res, 2510 const struct flowi4 *fl4, int orig_oif, 2511 struct net_device *dev_out, 2512 unsigned int flags) 2513 { 2514 struct fib_info *fi = res->fi; 2515 struct fib_nh_exception *fnhe; 2516 struct in_device *in_dev; 2517 u16 type = res->type; 2518 struct rtable *rth; 2519 bool do_cache; 2520 2521 in_dev = __in_dev_get_rcu(dev_out); 2522 if (!in_dev) 2523 return ERR_PTR(-EINVAL); 2524 2525 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2526 if (ipv4_is_loopback(fl4->saddr) && 2527 !(dev_out->flags & IFF_LOOPBACK) && 2528 !netif_is_l3_master(dev_out)) 2529 return ERR_PTR(-EINVAL); 2530 2531 if (ipv4_is_lbcast(fl4->daddr)) 2532 type = RTN_BROADCAST; 2533 else if (ipv4_is_multicast(fl4->daddr)) 2534 type = RTN_MULTICAST; 2535 else if (ipv4_is_zeronet(fl4->daddr)) 2536 return ERR_PTR(-EINVAL); 2537 2538 if (dev_out->flags & IFF_LOOPBACK) 2539 flags |= RTCF_LOCAL; 2540 2541 do_cache = true; 2542 if (type == RTN_BROADCAST) { 2543 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2544 fi = NULL; 2545 } else if (type == RTN_MULTICAST) { 2546 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2547 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2548 fl4->flowi4_proto)) 2549 flags &= ~RTCF_LOCAL; 2550 else 2551 do_cache = false; 2552 /* If multicast route do not exist use 2553 * default one, but do not gateway in this case. 2554 * Yes, it is hack. 2555 */ 2556 if (fi && res->prefixlen < 4) 2557 fi = NULL; 2558 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2559 (orig_oif != dev_out->ifindex)) { 2560 /* For local routes that require a particular output interface 2561 * we do not want to cache the result. Caching the result 2562 * causes incorrect behaviour when there are multiple source 2563 * addresses on the interface, the end result being that if the 2564 * intended recipient is waiting on that interface for the 2565 * packet he won't receive it because it will be delivered on 2566 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2567 * be set to the loopback interface as well. 2568 */ 2569 do_cache = false; 2570 } 2571 2572 fnhe = NULL; 2573 do_cache &= fi != NULL; 2574 if (fi) { 2575 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2576 struct rtable __rcu **prth; 2577 2578 fnhe = find_exception(nhc, fl4->daddr); 2579 if (!do_cache) 2580 goto add; 2581 if (fnhe) { 2582 prth = &fnhe->fnhe_rth_output; 2583 } else { 2584 if (unlikely(fl4->flowi4_flags & 2585 FLOWI_FLAG_KNOWN_NH && 2586 !(nhc->nhc_gw_family && 2587 nhc->nhc_scope == RT_SCOPE_LINK))) { 2588 do_cache = false; 2589 goto add; 2590 } 2591 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2592 } 2593 rth = rcu_dereference(*prth); 2594 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2595 return rth; 2596 } 2597 2598 add: 2599 rth = rt_dst_alloc(dev_out, flags, type, 2600 IN_DEV_ORCONF(in_dev, NOPOLICY), 2601 IN_DEV_ORCONF(in_dev, NOXFRM)); 2602 if (!rth) 2603 return ERR_PTR(-ENOBUFS); 2604 2605 rth->rt_iif = orig_oif; 2606 2607 RT_CACHE_STAT_INC(out_slow_tot); 2608 2609 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2610 if (flags & RTCF_LOCAL && 2611 !(dev_out->flags & IFF_LOOPBACK)) { 2612 rth->dst.output = ip_mc_output; 2613 RT_CACHE_STAT_INC(out_slow_mc); 2614 } 2615 #ifdef CONFIG_IP_MROUTE 2616 if (type == RTN_MULTICAST) { 2617 if (IN_DEV_MFORWARD(in_dev) && 2618 !ipv4_is_local_multicast(fl4->daddr)) { 2619 rth->dst.input = ip_mr_input; 2620 rth->dst.output = ip_mc_output; 2621 } 2622 } 2623 #endif 2624 } 2625 2626 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2627 lwtunnel_set_redirect(&rth->dst); 2628 2629 return rth; 2630 } 2631 2632 /* 2633 * Major route resolver routine. 2634 */ 2635 2636 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2637 const struct sk_buff *skb) 2638 { 2639 struct fib_result res = { 2640 .type = RTN_UNSPEC, 2641 .fi = NULL, 2642 .table = NULL, 2643 .tclassid = 0, 2644 }; 2645 struct rtable *rth; 2646 2647 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2648 ip_rt_fix_tos(fl4); 2649 2650 rcu_read_lock(); 2651 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2652 rcu_read_unlock(); 2653 2654 return rth; 2655 } 2656 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2657 2658 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2659 struct fib_result *res, 2660 const struct sk_buff *skb) 2661 { 2662 struct net_device *dev_out = NULL; 2663 int orig_oif = fl4->flowi4_oif; 2664 unsigned int flags = 0; 2665 struct rtable *rth; 2666 int err; 2667 2668 if (fl4->saddr) { 2669 if (ipv4_is_multicast(fl4->saddr) || 2670 ipv4_is_lbcast(fl4->saddr) || 2671 ipv4_is_zeronet(fl4->saddr)) { 2672 rth = ERR_PTR(-EINVAL); 2673 goto out; 2674 } 2675 2676 rth = ERR_PTR(-ENETUNREACH); 2677 2678 /* I removed check for oif == dev_out->oif here. 2679 * It was wrong for two reasons: 2680 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2681 * is assigned to multiple interfaces. 2682 * 2. Moreover, we are allowed to send packets with saddr 2683 * of another iface. --ANK 2684 */ 2685 2686 if (fl4->flowi4_oif == 0 && 2687 (ipv4_is_multicast(fl4->daddr) || 2688 ipv4_is_lbcast(fl4->daddr))) { 2689 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2690 dev_out = __ip_dev_find(net, fl4->saddr, false); 2691 if (!dev_out) 2692 goto out; 2693 2694 /* Special hack: user can direct multicasts 2695 * and limited broadcast via necessary interface 2696 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2697 * This hack is not just for fun, it allows 2698 * vic,vat and friends to work. 2699 * They bind socket to loopback, set ttl to zero 2700 * and expect that it will work. 2701 * From the viewpoint of routing cache they are broken, 2702 * because we are not allowed to build multicast path 2703 * with loopback source addr (look, routing cache 2704 * cannot know, that ttl is zero, so that packet 2705 * will not leave this host and route is valid). 2706 * Luckily, this hack is good workaround. 2707 */ 2708 2709 fl4->flowi4_oif = dev_out->ifindex; 2710 goto make_route; 2711 } 2712 2713 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2714 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2715 if (!__ip_dev_find(net, fl4->saddr, false)) 2716 goto out; 2717 } 2718 } 2719 2720 2721 if (fl4->flowi4_oif) { 2722 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2723 rth = ERR_PTR(-ENODEV); 2724 if (!dev_out) 2725 goto out; 2726 2727 /* RACE: Check return value of inet_select_addr instead. */ 2728 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2729 rth = ERR_PTR(-ENETUNREACH); 2730 goto out; 2731 } 2732 if (ipv4_is_local_multicast(fl4->daddr) || 2733 ipv4_is_lbcast(fl4->daddr) || 2734 fl4->flowi4_proto == IPPROTO_IGMP) { 2735 if (!fl4->saddr) 2736 fl4->saddr = inet_select_addr(dev_out, 0, 2737 RT_SCOPE_LINK); 2738 goto make_route; 2739 } 2740 if (!fl4->saddr) { 2741 if (ipv4_is_multicast(fl4->daddr)) 2742 fl4->saddr = inet_select_addr(dev_out, 0, 2743 fl4->flowi4_scope); 2744 else if (!fl4->daddr) 2745 fl4->saddr = inet_select_addr(dev_out, 0, 2746 RT_SCOPE_HOST); 2747 } 2748 } 2749 2750 if (!fl4->daddr) { 2751 fl4->daddr = fl4->saddr; 2752 if (!fl4->daddr) 2753 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2754 dev_out = net->loopback_dev; 2755 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2756 res->type = RTN_LOCAL; 2757 flags |= RTCF_LOCAL; 2758 goto make_route; 2759 } 2760 2761 err = fib_lookup(net, fl4, res, 0); 2762 if (err) { 2763 res->fi = NULL; 2764 res->table = NULL; 2765 if (fl4->flowi4_oif && 2766 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2767 /* Apparently, routing tables are wrong. Assume, 2768 * that the destination is on link. 2769 * 2770 * WHY? DW. 2771 * Because we are allowed to send to iface 2772 * even if it has NO routes and NO assigned 2773 * addresses. When oif is specified, routing 2774 * tables are looked up with only one purpose: 2775 * to catch if destination is gatewayed, rather than 2776 * direct. Moreover, if MSG_DONTROUTE is set, 2777 * we send packet, ignoring both routing tables 2778 * and ifaddr state. --ANK 2779 * 2780 * 2781 * We could make it even if oif is unknown, 2782 * likely IPv6, but we do not. 2783 */ 2784 2785 if (fl4->saddr == 0) 2786 fl4->saddr = inet_select_addr(dev_out, 0, 2787 RT_SCOPE_LINK); 2788 res->type = RTN_UNICAST; 2789 goto make_route; 2790 } 2791 rth = ERR_PTR(err); 2792 goto out; 2793 } 2794 2795 if (res->type == RTN_LOCAL) { 2796 if (!fl4->saddr) { 2797 if (res->fi->fib_prefsrc) 2798 fl4->saddr = res->fi->fib_prefsrc; 2799 else 2800 fl4->saddr = fl4->daddr; 2801 } 2802 2803 /* L3 master device is the loopback for that domain */ 2804 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2805 net->loopback_dev; 2806 2807 /* make sure orig_oif points to fib result device even 2808 * though packet rx/tx happens over loopback or l3mdev 2809 */ 2810 orig_oif = FIB_RES_OIF(*res); 2811 2812 fl4->flowi4_oif = dev_out->ifindex; 2813 flags |= RTCF_LOCAL; 2814 goto make_route; 2815 } 2816 2817 fib_select_path(net, res, fl4, skb); 2818 2819 dev_out = FIB_RES_DEV(*res); 2820 2821 make_route: 2822 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2823 2824 out: 2825 return rth; 2826 } 2827 2828 static struct dst_ops ipv4_dst_blackhole_ops = { 2829 .family = AF_INET, 2830 .default_advmss = ipv4_default_advmss, 2831 .neigh_lookup = ipv4_neigh_lookup, 2832 .check = dst_blackhole_check, 2833 .cow_metrics = dst_blackhole_cow_metrics, 2834 .update_pmtu = dst_blackhole_update_pmtu, 2835 .redirect = dst_blackhole_redirect, 2836 .mtu = dst_blackhole_mtu, 2837 }; 2838 2839 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2840 { 2841 struct rtable *ort = (struct rtable *) dst_orig; 2842 struct rtable *rt; 2843 2844 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2845 if (rt) { 2846 struct dst_entry *new = &rt->dst; 2847 2848 new->__use = 1; 2849 new->input = dst_discard; 2850 new->output = dst_discard_out; 2851 2852 new->dev = net->loopback_dev; 2853 dev_hold_track(new->dev, &new->dev_tracker, GFP_ATOMIC); 2854 2855 rt->rt_is_input = ort->rt_is_input; 2856 rt->rt_iif = ort->rt_iif; 2857 rt->rt_pmtu = ort->rt_pmtu; 2858 rt->rt_mtu_locked = ort->rt_mtu_locked; 2859 2860 rt->rt_genid = rt_genid_ipv4(net); 2861 rt->rt_flags = ort->rt_flags; 2862 rt->rt_type = ort->rt_type; 2863 rt->rt_uses_gateway = ort->rt_uses_gateway; 2864 rt->rt_gw_family = ort->rt_gw_family; 2865 if (rt->rt_gw_family == AF_INET) 2866 rt->rt_gw4 = ort->rt_gw4; 2867 else if (rt->rt_gw_family == AF_INET6) 2868 rt->rt_gw6 = ort->rt_gw6; 2869 2870 INIT_LIST_HEAD(&rt->rt_uncached); 2871 } 2872 2873 dst_release(dst_orig); 2874 2875 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2876 } 2877 2878 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2879 const struct sock *sk) 2880 { 2881 struct rtable *rt = __ip_route_output_key(net, flp4); 2882 2883 if (IS_ERR(rt)) 2884 return rt; 2885 2886 if (flp4->flowi4_proto) { 2887 flp4->flowi4_oif = rt->dst.dev->ifindex; 2888 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2889 flowi4_to_flowi(flp4), 2890 sk, 0); 2891 } 2892 2893 return rt; 2894 } 2895 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2896 2897 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2898 struct net_device *dev, 2899 struct net *net, __be32 *saddr, 2900 const struct ip_tunnel_info *info, 2901 u8 protocol, bool use_cache) 2902 { 2903 #ifdef CONFIG_DST_CACHE 2904 struct dst_cache *dst_cache; 2905 #endif 2906 struct rtable *rt = NULL; 2907 struct flowi4 fl4; 2908 __u8 tos; 2909 2910 #ifdef CONFIG_DST_CACHE 2911 dst_cache = (struct dst_cache *)&info->dst_cache; 2912 if (use_cache) { 2913 rt = dst_cache_get_ip4(dst_cache, saddr); 2914 if (rt) 2915 return rt; 2916 } 2917 #endif 2918 memset(&fl4, 0, sizeof(fl4)); 2919 fl4.flowi4_mark = skb->mark; 2920 fl4.flowi4_proto = protocol; 2921 fl4.daddr = info->key.u.ipv4.dst; 2922 fl4.saddr = info->key.u.ipv4.src; 2923 tos = info->key.tos; 2924 fl4.flowi4_tos = RT_TOS(tos); 2925 2926 rt = ip_route_output_key(net, &fl4); 2927 if (IS_ERR(rt)) { 2928 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2929 return ERR_PTR(-ENETUNREACH); 2930 } 2931 if (rt->dst.dev == dev) { /* is this necessary? */ 2932 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2933 ip_rt_put(rt); 2934 return ERR_PTR(-ELOOP); 2935 } 2936 #ifdef CONFIG_DST_CACHE 2937 if (use_cache) 2938 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2939 #endif 2940 *saddr = fl4.saddr; 2941 return rt; 2942 } 2943 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2944 2945 /* called with rcu_read_lock held */ 2946 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2947 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2948 struct sk_buff *skb, u32 portid, u32 seq, 2949 unsigned int flags) 2950 { 2951 struct rtmsg *r; 2952 struct nlmsghdr *nlh; 2953 unsigned long expires = 0; 2954 u32 error; 2955 u32 metrics[RTAX_MAX]; 2956 2957 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2958 if (!nlh) 2959 return -EMSGSIZE; 2960 2961 r = nlmsg_data(nlh); 2962 r->rtm_family = AF_INET; 2963 r->rtm_dst_len = 32; 2964 r->rtm_src_len = 0; 2965 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2966 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2967 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2968 goto nla_put_failure; 2969 r->rtm_type = rt->rt_type; 2970 r->rtm_scope = RT_SCOPE_UNIVERSE; 2971 r->rtm_protocol = RTPROT_UNSPEC; 2972 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2973 if (rt->rt_flags & RTCF_NOTIFY) 2974 r->rtm_flags |= RTM_F_NOTIFY; 2975 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2976 r->rtm_flags |= RTCF_DOREDIRECT; 2977 2978 if (nla_put_in_addr(skb, RTA_DST, dst)) 2979 goto nla_put_failure; 2980 if (src) { 2981 r->rtm_src_len = 32; 2982 if (nla_put_in_addr(skb, RTA_SRC, src)) 2983 goto nla_put_failure; 2984 } 2985 if (rt->dst.dev && 2986 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2987 goto nla_put_failure; 2988 if (rt->dst.lwtstate && 2989 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2990 goto nla_put_failure; 2991 #ifdef CONFIG_IP_ROUTE_CLASSID 2992 if (rt->dst.tclassid && 2993 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2994 goto nla_put_failure; 2995 #endif 2996 if (fl4 && !rt_is_input_route(rt) && 2997 fl4->saddr != src) { 2998 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2999 goto nla_put_failure; 3000 } 3001 if (rt->rt_uses_gateway) { 3002 if (rt->rt_gw_family == AF_INET && 3003 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3004 goto nla_put_failure; 3005 } else if (rt->rt_gw_family == AF_INET6) { 3006 int alen = sizeof(struct in6_addr); 3007 struct nlattr *nla; 3008 struct rtvia *via; 3009 3010 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3011 if (!nla) 3012 goto nla_put_failure; 3013 3014 via = nla_data(nla); 3015 via->rtvia_family = AF_INET6; 3016 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3017 } 3018 } 3019 3020 expires = rt->dst.expires; 3021 if (expires) { 3022 unsigned long now = jiffies; 3023 3024 if (time_before(now, expires)) 3025 expires -= now; 3026 else 3027 expires = 0; 3028 } 3029 3030 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3031 if (rt->rt_pmtu && expires) 3032 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3033 if (rt->rt_mtu_locked && expires) 3034 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3035 if (rtnetlink_put_metrics(skb, metrics) < 0) 3036 goto nla_put_failure; 3037 3038 if (fl4) { 3039 if (fl4->flowi4_mark && 3040 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3041 goto nla_put_failure; 3042 3043 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3044 nla_put_u32(skb, RTA_UID, 3045 from_kuid_munged(current_user_ns(), 3046 fl4->flowi4_uid))) 3047 goto nla_put_failure; 3048 3049 if (rt_is_input_route(rt)) { 3050 #ifdef CONFIG_IP_MROUTE 3051 if (ipv4_is_multicast(dst) && 3052 !ipv4_is_local_multicast(dst) && 3053 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3054 int err = ipmr_get_route(net, skb, 3055 fl4->saddr, fl4->daddr, 3056 r, portid); 3057 3058 if (err <= 0) { 3059 if (err == 0) 3060 return 0; 3061 goto nla_put_failure; 3062 } 3063 } else 3064 #endif 3065 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3066 goto nla_put_failure; 3067 } 3068 } 3069 3070 error = rt->dst.error; 3071 3072 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3073 goto nla_put_failure; 3074 3075 nlmsg_end(skb, nlh); 3076 return 0; 3077 3078 nla_put_failure: 3079 nlmsg_cancel(skb, nlh); 3080 return -EMSGSIZE; 3081 } 3082 3083 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3084 struct netlink_callback *cb, u32 table_id, 3085 struct fnhe_hash_bucket *bucket, int genid, 3086 int *fa_index, int fa_start, unsigned int flags) 3087 { 3088 int i; 3089 3090 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3091 struct fib_nh_exception *fnhe; 3092 3093 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3094 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3095 struct rtable *rt; 3096 int err; 3097 3098 if (*fa_index < fa_start) 3099 goto next; 3100 3101 if (fnhe->fnhe_genid != genid) 3102 goto next; 3103 3104 if (fnhe->fnhe_expires && 3105 time_after(jiffies, fnhe->fnhe_expires)) 3106 goto next; 3107 3108 rt = rcu_dereference(fnhe->fnhe_rth_input); 3109 if (!rt) 3110 rt = rcu_dereference(fnhe->fnhe_rth_output); 3111 if (!rt) 3112 goto next; 3113 3114 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3115 table_id, NULL, skb, 3116 NETLINK_CB(cb->skb).portid, 3117 cb->nlh->nlmsg_seq, flags); 3118 if (err) 3119 return err; 3120 next: 3121 (*fa_index)++; 3122 } 3123 } 3124 3125 return 0; 3126 } 3127 3128 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3129 u32 table_id, struct fib_info *fi, 3130 int *fa_index, int fa_start, unsigned int flags) 3131 { 3132 struct net *net = sock_net(cb->skb->sk); 3133 int nhsel, genid = fnhe_genid(net); 3134 3135 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3136 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3137 struct fnhe_hash_bucket *bucket; 3138 int err; 3139 3140 if (nhc->nhc_flags & RTNH_F_DEAD) 3141 continue; 3142 3143 rcu_read_lock(); 3144 bucket = rcu_dereference(nhc->nhc_exceptions); 3145 err = 0; 3146 if (bucket) 3147 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3148 genid, fa_index, fa_start, 3149 flags); 3150 rcu_read_unlock(); 3151 if (err) 3152 return err; 3153 } 3154 3155 return 0; 3156 } 3157 3158 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3159 u8 ip_proto, __be16 sport, 3160 __be16 dport) 3161 { 3162 struct sk_buff *skb; 3163 struct iphdr *iph; 3164 3165 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3166 if (!skb) 3167 return NULL; 3168 3169 /* Reserve room for dummy headers, this skb can pass 3170 * through good chunk of routing engine. 3171 */ 3172 skb_reset_mac_header(skb); 3173 skb_reset_network_header(skb); 3174 skb->protocol = htons(ETH_P_IP); 3175 iph = skb_put(skb, sizeof(struct iphdr)); 3176 iph->protocol = ip_proto; 3177 iph->saddr = src; 3178 iph->daddr = dst; 3179 iph->version = 0x4; 3180 iph->frag_off = 0; 3181 iph->ihl = 0x5; 3182 skb_set_transport_header(skb, skb->len); 3183 3184 switch (iph->protocol) { 3185 case IPPROTO_UDP: { 3186 struct udphdr *udph; 3187 3188 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3189 udph->source = sport; 3190 udph->dest = dport; 3191 udph->len = htons(sizeof(struct udphdr)); 3192 udph->check = 0; 3193 break; 3194 } 3195 case IPPROTO_TCP: { 3196 struct tcphdr *tcph; 3197 3198 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3199 tcph->source = sport; 3200 tcph->dest = dport; 3201 tcph->doff = sizeof(struct tcphdr) / 4; 3202 tcph->rst = 1; 3203 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3204 src, dst, 0); 3205 break; 3206 } 3207 case IPPROTO_ICMP: { 3208 struct icmphdr *icmph; 3209 3210 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3211 icmph->type = ICMP_ECHO; 3212 icmph->code = 0; 3213 } 3214 } 3215 3216 return skb; 3217 } 3218 3219 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3220 const struct nlmsghdr *nlh, 3221 struct nlattr **tb, 3222 struct netlink_ext_ack *extack) 3223 { 3224 struct rtmsg *rtm; 3225 int i, err; 3226 3227 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3228 NL_SET_ERR_MSG(extack, 3229 "ipv4: Invalid header for route get request"); 3230 return -EINVAL; 3231 } 3232 3233 if (!netlink_strict_get_check(skb)) 3234 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3235 rtm_ipv4_policy, extack); 3236 3237 rtm = nlmsg_data(nlh); 3238 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3239 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3240 rtm->rtm_table || rtm->rtm_protocol || 3241 rtm->rtm_scope || rtm->rtm_type) { 3242 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3243 return -EINVAL; 3244 } 3245 3246 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3247 RTM_F_LOOKUP_TABLE | 3248 RTM_F_FIB_MATCH)) { 3249 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3250 return -EINVAL; 3251 } 3252 3253 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3254 rtm_ipv4_policy, extack); 3255 if (err) 3256 return err; 3257 3258 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3259 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3260 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3261 return -EINVAL; 3262 } 3263 3264 for (i = 0; i <= RTA_MAX; i++) { 3265 if (!tb[i]) 3266 continue; 3267 3268 switch (i) { 3269 case RTA_IIF: 3270 case RTA_OIF: 3271 case RTA_SRC: 3272 case RTA_DST: 3273 case RTA_IP_PROTO: 3274 case RTA_SPORT: 3275 case RTA_DPORT: 3276 case RTA_MARK: 3277 case RTA_UID: 3278 break; 3279 default: 3280 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3281 return -EINVAL; 3282 } 3283 } 3284 3285 return 0; 3286 } 3287 3288 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3289 struct netlink_ext_ack *extack) 3290 { 3291 struct net *net = sock_net(in_skb->sk); 3292 struct nlattr *tb[RTA_MAX+1]; 3293 u32 table_id = RT_TABLE_MAIN; 3294 __be16 sport = 0, dport = 0; 3295 struct fib_result res = {}; 3296 u8 ip_proto = IPPROTO_UDP; 3297 struct rtable *rt = NULL; 3298 struct sk_buff *skb; 3299 struct rtmsg *rtm; 3300 struct flowi4 fl4 = {}; 3301 __be32 dst = 0; 3302 __be32 src = 0; 3303 kuid_t uid; 3304 u32 iif; 3305 int err; 3306 int mark; 3307 3308 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3309 if (err < 0) 3310 return err; 3311 3312 rtm = nlmsg_data(nlh); 3313 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3314 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3315 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3316 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3317 if (tb[RTA_UID]) 3318 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3319 else 3320 uid = (iif ? INVALID_UID : current_uid()); 3321 3322 if (tb[RTA_IP_PROTO]) { 3323 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3324 &ip_proto, AF_INET, extack); 3325 if (err) 3326 return err; 3327 } 3328 3329 if (tb[RTA_SPORT]) 3330 sport = nla_get_be16(tb[RTA_SPORT]); 3331 3332 if (tb[RTA_DPORT]) 3333 dport = nla_get_be16(tb[RTA_DPORT]); 3334 3335 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3336 if (!skb) 3337 return -ENOBUFS; 3338 3339 fl4.daddr = dst; 3340 fl4.saddr = src; 3341 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3342 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3343 fl4.flowi4_mark = mark; 3344 fl4.flowi4_uid = uid; 3345 if (sport) 3346 fl4.fl4_sport = sport; 3347 if (dport) 3348 fl4.fl4_dport = dport; 3349 fl4.flowi4_proto = ip_proto; 3350 3351 rcu_read_lock(); 3352 3353 if (iif) { 3354 struct net_device *dev; 3355 3356 dev = dev_get_by_index_rcu(net, iif); 3357 if (!dev) { 3358 err = -ENODEV; 3359 goto errout_rcu; 3360 } 3361 3362 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3363 skb->dev = dev; 3364 skb->mark = mark; 3365 err = ip_route_input_rcu(skb, dst, src, 3366 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3367 &res); 3368 3369 rt = skb_rtable(skb); 3370 if (err == 0 && rt->dst.error) 3371 err = -rt->dst.error; 3372 } else { 3373 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3374 skb->dev = net->loopback_dev; 3375 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3376 err = 0; 3377 if (IS_ERR(rt)) 3378 err = PTR_ERR(rt); 3379 else 3380 skb_dst_set(skb, &rt->dst); 3381 } 3382 3383 if (err) 3384 goto errout_rcu; 3385 3386 if (rtm->rtm_flags & RTM_F_NOTIFY) 3387 rt->rt_flags |= RTCF_NOTIFY; 3388 3389 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3390 table_id = res.table ? res.table->tb_id : 0; 3391 3392 /* reset skb for netlink reply msg */ 3393 skb_trim(skb, 0); 3394 skb_reset_network_header(skb); 3395 skb_reset_transport_header(skb); 3396 skb_reset_mac_header(skb); 3397 3398 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3399 struct fib_rt_info fri; 3400 3401 if (!res.fi) { 3402 err = fib_props[res.type].error; 3403 if (!err) 3404 err = -EHOSTUNREACH; 3405 goto errout_rcu; 3406 } 3407 fri.fi = res.fi; 3408 fri.tb_id = table_id; 3409 fri.dst = res.prefix; 3410 fri.dst_len = res.prefixlen; 3411 fri.tos = fl4.flowi4_tos; 3412 fri.type = rt->rt_type; 3413 fri.offload = 0; 3414 fri.trap = 0; 3415 fri.offload_failed = 0; 3416 if (res.fa_head) { 3417 struct fib_alias *fa; 3418 3419 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3420 u8 slen = 32 - fri.dst_len; 3421 3422 if (fa->fa_slen == slen && 3423 fa->tb_id == fri.tb_id && 3424 fa->fa_dscp == inet_dsfield_to_dscp(fri.tos) && 3425 fa->fa_info == res.fi && 3426 fa->fa_type == fri.type) { 3427 fri.offload = READ_ONCE(fa->offload); 3428 fri.trap = READ_ONCE(fa->trap); 3429 break; 3430 } 3431 } 3432 } 3433 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3434 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3435 } else { 3436 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3437 NETLINK_CB(in_skb).portid, 3438 nlh->nlmsg_seq, 0); 3439 } 3440 if (err < 0) 3441 goto errout_rcu; 3442 3443 rcu_read_unlock(); 3444 3445 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3446 3447 errout_free: 3448 return err; 3449 errout_rcu: 3450 rcu_read_unlock(); 3451 kfree_skb(skb); 3452 goto errout_free; 3453 } 3454 3455 void ip_rt_multicast_event(struct in_device *in_dev) 3456 { 3457 rt_cache_flush(dev_net(in_dev->dev)); 3458 } 3459 3460 #ifdef CONFIG_SYSCTL 3461 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3462 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3463 static int ip_rt_gc_elasticity __read_mostly = 8; 3464 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3465 3466 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3467 void *buffer, size_t *lenp, loff_t *ppos) 3468 { 3469 struct net *net = (struct net *)__ctl->extra1; 3470 3471 if (write) { 3472 rt_cache_flush(net); 3473 fnhe_genid_bump(net); 3474 return 0; 3475 } 3476 3477 return -EINVAL; 3478 } 3479 3480 static struct ctl_table ipv4_route_table[] = { 3481 { 3482 .procname = "gc_thresh", 3483 .data = &ipv4_dst_ops.gc_thresh, 3484 .maxlen = sizeof(int), 3485 .mode = 0644, 3486 .proc_handler = proc_dointvec, 3487 }, 3488 { 3489 .procname = "max_size", 3490 .data = &ip_rt_max_size, 3491 .maxlen = sizeof(int), 3492 .mode = 0644, 3493 .proc_handler = proc_dointvec, 3494 }, 3495 { 3496 /* Deprecated. Use gc_min_interval_ms */ 3497 3498 .procname = "gc_min_interval", 3499 .data = &ip_rt_gc_min_interval, 3500 .maxlen = sizeof(int), 3501 .mode = 0644, 3502 .proc_handler = proc_dointvec_jiffies, 3503 }, 3504 { 3505 .procname = "gc_min_interval_ms", 3506 .data = &ip_rt_gc_min_interval, 3507 .maxlen = sizeof(int), 3508 .mode = 0644, 3509 .proc_handler = proc_dointvec_ms_jiffies, 3510 }, 3511 { 3512 .procname = "gc_timeout", 3513 .data = &ip_rt_gc_timeout, 3514 .maxlen = sizeof(int), 3515 .mode = 0644, 3516 .proc_handler = proc_dointvec_jiffies, 3517 }, 3518 { 3519 .procname = "gc_interval", 3520 .data = &ip_rt_gc_interval, 3521 .maxlen = sizeof(int), 3522 .mode = 0644, 3523 .proc_handler = proc_dointvec_jiffies, 3524 }, 3525 { 3526 .procname = "redirect_load", 3527 .data = &ip_rt_redirect_load, 3528 .maxlen = sizeof(int), 3529 .mode = 0644, 3530 .proc_handler = proc_dointvec, 3531 }, 3532 { 3533 .procname = "redirect_number", 3534 .data = &ip_rt_redirect_number, 3535 .maxlen = sizeof(int), 3536 .mode = 0644, 3537 .proc_handler = proc_dointvec, 3538 }, 3539 { 3540 .procname = "redirect_silence", 3541 .data = &ip_rt_redirect_silence, 3542 .maxlen = sizeof(int), 3543 .mode = 0644, 3544 .proc_handler = proc_dointvec, 3545 }, 3546 { 3547 .procname = "error_cost", 3548 .data = &ip_rt_error_cost, 3549 .maxlen = sizeof(int), 3550 .mode = 0644, 3551 .proc_handler = proc_dointvec, 3552 }, 3553 { 3554 .procname = "error_burst", 3555 .data = &ip_rt_error_burst, 3556 .maxlen = sizeof(int), 3557 .mode = 0644, 3558 .proc_handler = proc_dointvec, 3559 }, 3560 { 3561 .procname = "gc_elasticity", 3562 .data = &ip_rt_gc_elasticity, 3563 .maxlen = sizeof(int), 3564 .mode = 0644, 3565 .proc_handler = proc_dointvec, 3566 }, 3567 { } 3568 }; 3569 3570 static const char ipv4_route_flush_procname[] = "flush"; 3571 3572 static struct ctl_table ipv4_route_netns_table[] = { 3573 { 3574 .procname = ipv4_route_flush_procname, 3575 .maxlen = sizeof(int), 3576 .mode = 0200, 3577 .proc_handler = ipv4_sysctl_rtcache_flush, 3578 }, 3579 { 3580 .procname = "min_pmtu", 3581 .data = &init_net.ipv4.ip_rt_min_pmtu, 3582 .maxlen = sizeof(int), 3583 .mode = 0644, 3584 .proc_handler = proc_dointvec_minmax, 3585 .extra1 = &ip_min_valid_pmtu, 3586 }, 3587 { 3588 .procname = "mtu_expires", 3589 .data = &init_net.ipv4.ip_rt_mtu_expires, 3590 .maxlen = sizeof(int), 3591 .mode = 0644, 3592 .proc_handler = proc_dointvec_jiffies, 3593 }, 3594 { 3595 .procname = "min_adv_mss", 3596 .data = &init_net.ipv4.ip_rt_min_advmss, 3597 .maxlen = sizeof(int), 3598 .mode = 0644, 3599 .proc_handler = proc_dointvec, 3600 }, 3601 { }, 3602 }; 3603 3604 static __net_init int sysctl_route_net_init(struct net *net) 3605 { 3606 struct ctl_table *tbl; 3607 3608 tbl = ipv4_route_netns_table; 3609 if (!net_eq(net, &init_net)) { 3610 int i; 3611 3612 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3613 if (!tbl) 3614 goto err_dup; 3615 3616 /* Don't export non-whitelisted sysctls to unprivileged users */ 3617 if (net->user_ns != &init_user_ns) { 3618 if (tbl[0].procname != ipv4_route_flush_procname) 3619 tbl[0].procname = NULL; 3620 } 3621 3622 /* Update the variables to point into the current struct net 3623 * except for the first element flush 3624 */ 3625 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3626 tbl[i].data += (void *)net - (void *)&init_net; 3627 } 3628 tbl[0].extra1 = net; 3629 3630 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3631 if (!net->ipv4.route_hdr) 3632 goto err_reg; 3633 return 0; 3634 3635 err_reg: 3636 if (tbl != ipv4_route_netns_table) 3637 kfree(tbl); 3638 err_dup: 3639 return -ENOMEM; 3640 } 3641 3642 static __net_exit void sysctl_route_net_exit(struct net *net) 3643 { 3644 struct ctl_table *tbl; 3645 3646 tbl = net->ipv4.route_hdr->ctl_table_arg; 3647 unregister_net_sysctl_table(net->ipv4.route_hdr); 3648 BUG_ON(tbl == ipv4_route_netns_table); 3649 kfree(tbl); 3650 } 3651 3652 static __net_initdata struct pernet_operations sysctl_route_ops = { 3653 .init = sysctl_route_net_init, 3654 .exit = sysctl_route_net_exit, 3655 }; 3656 #endif 3657 3658 static __net_init int netns_ip_rt_init(struct net *net) 3659 { 3660 /* Set default value for namespaceified sysctls */ 3661 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3662 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3663 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3664 return 0; 3665 } 3666 3667 static struct pernet_operations __net_initdata ip_rt_ops = { 3668 .init = netns_ip_rt_init, 3669 }; 3670 3671 static __net_init int rt_genid_init(struct net *net) 3672 { 3673 atomic_set(&net->ipv4.rt_genid, 0); 3674 atomic_set(&net->fnhe_genid, 0); 3675 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3676 return 0; 3677 } 3678 3679 static __net_initdata struct pernet_operations rt_genid_ops = { 3680 .init = rt_genid_init, 3681 }; 3682 3683 static int __net_init ipv4_inetpeer_init(struct net *net) 3684 { 3685 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3686 3687 if (!bp) 3688 return -ENOMEM; 3689 inet_peer_base_init(bp); 3690 net->ipv4.peers = bp; 3691 return 0; 3692 } 3693 3694 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3695 { 3696 struct inet_peer_base *bp = net->ipv4.peers; 3697 3698 net->ipv4.peers = NULL; 3699 inetpeer_invalidate_tree(bp); 3700 kfree(bp); 3701 } 3702 3703 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3704 .init = ipv4_inetpeer_init, 3705 .exit = ipv4_inetpeer_exit, 3706 }; 3707 3708 #ifdef CONFIG_IP_ROUTE_CLASSID 3709 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3710 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3711 3712 int __init ip_rt_init(void) 3713 { 3714 void *idents_hash; 3715 int cpu; 3716 3717 /* For modern hosts, this will use 2 MB of memory */ 3718 idents_hash = alloc_large_system_hash("IP idents", 3719 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3720 0, 3721 16, /* one bucket per 64 KB */ 3722 HASH_ZERO, 3723 NULL, 3724 &ip_idents_mask, 3725 2048, 3726 256*1024); 3727 3728 ip_idents = idents_hash; 3729 3730 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3731 3732 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3733 3734 for_each_possible_cpu(cpu) { 3735 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3736 3737 INIT_LIST_HEAD(&ul->head); 3738 INIT_LIST_HEAD(&ul->quarantine); 3739 spin_lock_init(&ul->lock); 3740 } 3741 #ifdef CONFIG_IP_ROUTE_CLASSID 3742 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3743 if (!ip_rt_acct) 3744 panic("IP: failed to allocate ip_rt_acct\n"); 3745 #endif 3746 3747 ipv4_dst_ops.kmem_cachep = 3748 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3749 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3750 3751 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3752 3753 if (dst_entries_init(&ipv4_dst_ops) < 0) 3754 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3755 3756 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3757 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3758 3759 ipv4_dst_ops.gc_thresh = ~0; 3760 ip_rt_max_size = INT_MAX; 3761 3762 devinet_init(); 3763 ip_fib_init(); 3764 3765 if (ip_rt_proc_init()) 3766 pr_err("Unable to create route proc files\n"); 3767 #ifdef CONFIG_XFRM 3768 xfrm_init(); 3769 xfrm4_init(); 3770 #endif 3771 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3772 RTNL_FLAG_DOIT_UNLOCKED); 3773 3774 #ifdef CONFIG_SYSCTL 3775 register_pernet_subsys(&sysctl_route_ops); 3776 #endif 3777 register_pernet_subsys(&ip_rt_ops); 3778 register_pernet_subsys(&rt_genid_ops); 3779 register_pernet_subsys(&ipv4_inetpeer_ops); 3780 return 0; 3781 } 3782 3783 #ifdef CONFIG_SYSCTL 3784 /* 3785 * We really need to sanitize the damn ipv4 init order, then all 3786 * this nonsense will go away. 3787 */ 3788 void __init ip_static_sysctl_init(void) 3789 { 3790 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3791 } 3792 #endif 3793