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 void ipv4_negative_advice(struct sock *sk, 136 struct dst_entry *dst); 137 static void ipv4_link_failure(struct sk_buff *skb); 138 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 139 struct sk_buff *skb, u32 mtu, 140 bool confirm_neigh); 141 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 142 struct sk_buff *skb); 143 static void ipv4_dst_destroy(struct dst_entry *dst); 144 145 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 146 { 147 WARN_ON(1); 148 return NULL; 149 } 150 151 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 152 struct sk_buff *skb, 153 const void *daddr); 154 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 155 156 static struct dst_ops ipv4_dst_ops = { 157 .family = AF_INET, 158 .check = ipv4_dst_check, 159 .default_advmss = ipv4_default_advmss, 160 .mtu = ipv4_mtu, 161 .cow_metrics = ipv4_cow_metrics, 162 .destroy = ipv4_dst_destroy, 163 .negative_advice = ipv4_negative_advice, 164 .link_failure = ipv4_link_failure, 165 .update_pmtu = ip_rt_update_pmtu, 166 .redirect = ip_do_redirect, 167 .local_out = __ip_local_out, 168 .neigh_lookup = ipv4_neigh_lookup, 169 .confirm_neigh = ipv4_confirm_neigh, 170 }; 171 172 #define ECN_OR_COST(class) TC_PRIO_##class 173 174 const __u8 ip_tos2prio[16] = { 175 TC_PRIO_BESTEFFORT, 176 ECN_OR_COST(BESTEFFORT), 177 TC_PRIO_BESTEFFORT, 178 ECN_OR_COST(BESTEFFORT), 179 TC_PRIO_BULK, 180 ECN_OR_COST(BULK), 181 TC_PRIO_BULK, 182 ECN_OR_COST(BULK), 183 TC_PRIO_INTERACTIVE, 184 ECN_OR_COST(INTERACTIVE), 185 TC_PRIO_INTERACTIVE, 186 ECN_OR_COST(INTERACTIVE), 187 TC_PRIO_INTERACTIVE_BULK, 188 ECN_OR_COST(INTERACTIVE_BULK), 189 TC_PRIO_INTERACTIVE_BULK, 190 ECN_OR_COST(INTERACTIVE_BULK) 191 }; 192 EXPORT_SYMBOL(ip_tos2prio); 193 194 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 195 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 196 197 #ifdef CONFIG_PROC_FS 198 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 199 { 200 if (*pos) 201 return NULL; 202 return SEQ_START_TOKEN; 203 } 204 205 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 206 { 207 ++*pos; 208 return NULL; 209 } 210 211 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 212 { 213 } 214 215 static int rt_cache_seq_show(struct seq_file *seq, void *v) 216 { 217 if (v == SEQ_START_TOKEN) 218 seq_printf(seq, "%-127s\n", 219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 221 "HHUptod\tSpecDst"); 222 return 0; 223 } 224 225 static const struct seq_operations rt_cache_seq_ops = { 226 .start = rt_cache_seq_start, 227 .next = rt_cache_seq_next, 228 .stop = rt_cache_seq_stop, 229 .show = rt_cache_seq_show, 230 }; 231 232 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 233 { 234 int cpu; 235 236 if (*pos == 0) 237 return SEQ_START_TOKEN; 238 239 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 240 if (!cpu_possible(cpu)) 241 continue; 242 *pos = cpu+1; 243 return &per_cpu(rt_cache_stat, cpu); 244 } 245 return NULL; 246 } 247 248 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 249 { 250 int cpu; 251 252 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 253 if (!cpu_possible(cpu)) 254 continue; 255 *pos = cpu+1; 256 return &per_cpu(rt_cache_stat, cpu); 257 } 258 (*pos)++; 259 return NULL; 260 261 } 262 263 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 264 { 265 266 } 267 268 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 269 { 270 struct rt_cache_stat *st = v; 271 272 if (v == SEQ_START_TOKEN) { 273 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"); 274 return 0; 275 } 276 277 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 278 "%08x %08x %08x %08x %08x %08x " 279 "%08x %08x %08x %08x\n", 280 dst_entries_get_slow(&ipv4_dst_ops), 281 0, /* st->in_hit */ 282 st->in_slow_tot, 283 st->in_slow_mc, 284 st->in_no_route, 285 st->in_brd, 286 st->in_martian_dst, 287 st->in_martian_src, 288 289 0, /* st->out_hit */ 290 st->out_slow_tot, 291 st->out_slow_mc, 292 293 0, /* st->gc_total */ 294 0, /* st->gc_ignored */ 295 0, /* st->gc_goal_miss */ 296 0, /* st->gc_dst_overflow */ 297 0, /* st->in_hlist_search */ 298 0 /* st->out_hlist_search */ 299 ); 300 return 0; 301 } 302 303 static const struct seq_operations rt_cpu_seq_ops = { 304 .start = rt_cpu_seq_start, 305 .next = rt_cpu_seq_next, 306 .stop = rt_cpu_seq_stop, 307 .show = rt_cpu_seq_show, 308 }; 309 310 #ifdef CONFIG_IP_ROUTE_CLASSID 311 static int rt_acct_proc_show(struct seq_file *m, void *v) 312 { 313 struct ip_rt_acct *dst, *src; 314 unsigned int i, j; 315 316 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 317 if (!dst) 318 return -ENOMEM; 319 320 for_each_possible_cpu(i) { 321 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 322 for (j = 0; j < 256; j++) { 323 dst[j].o_bytes += src[j].o_bytes; 324 dst[j].o_packets += src[j].o_packets; 325 dst[j].i_bytes += src[j].i_bytes; 326 dst[j].i_packets += src[j].i_packets; 327 } 328 } 329 330 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 331 kfree(dst); 332 return 0; 333 } 334 #endif 335 336 static int __net_init ip_rt_do_proc_init(struct net *net) 337 { 338 struct proc_dir_entry *pde; 339 340 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 341 &rt_cache_seq_ops); 342 if (!pde) 343 goto err1; 344 345 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 346 &rt_cpu_seq_ops); 347 if (!pde) 348 goto err2; 349 350 #ifdef CONFIG_IP_ROUTE_CLASSID 351 pde = proc_create_single("rt_acct", 0, net->proc_net, 352 rt_acct_proc_show); 353 if (!pde) 354 goto err3; 355 #endif 356 return 0; 357 358 #ifdef CONFIG_IP_ROUTE_CLASSID 359 err3: 360 remove_proc_entry("rt_cache", net->proc_net_stat); 361 #endif 362 err2: 363 remove_proc_entry("rt_cache", net->proc_net); 364 err1: 365 return -ENOMEM; 366 } 367 368 static void __net_exit ip_rt_do_proc_exit(struct net *net) 369 { 370 remove_proc_entry("rt_cache", net->proc_net_stat); 371 remove_proc_entry("rt_cache", net->proc_net); 372 #ifdef CONFIG_IP_ROUTE_CLASSID 373 remove_proc_entry("rt_acct", net->proc_net); 374 #endif 375 } 376 377 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 378 .init = ip_rt_do_proc_init, 379 .exit = ip_rt_do_proc_exit, 380 }; 381 382 static int __init ip_rt_proc_init(void) 383 { 384 return register_pernet_subsys(&ip_rt_proc_ops); 385 } 386 387 #else 388 static inline int ip_rt_proc_init(void) 389 { 390 return 0; 391 } 392 #endif /* CONFIG_PROC_FS */ 393 394 static inline bool rt_is_expired(const struct rtable *rth) 395 { 396 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 397 } 398 399 void rt_cache_flush(struct net *net) 400 { 401 rt_genid_bump_ipv4(net); 402 } 403 404 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 405 struct sk_buff *skb, 406 const void *daddr) 407 { 408 const struct rtable *rt = container_of(dst, struct rtable, dst); 409 struct net_device *dev = dst->dev; 410 struct neighbour *n; 411 412 rcu_read_lock(); 413 414 if (likely(rt->rt_gw_family == AF_INET)) { 415 n = ip_neigh_gw4(dev, rt->rt_gw4); 416 } else if (rt->rt_gw_family == AF_INET6) { 417 n = ip_neigh_gw6(dev, &rt->rt_gw6); 418 } else { 419 __be32 pkey; 420 421 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 422 n = ip_neigh_gw4(dev, pkey); 423 } 424 425 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 426 n = NULL; 427 428 rcu_read_unlock(); 429 430 return n; 431 } 432 433 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 434 { 435 const struct rtable *rt = container_of(dst, struct rtable, dst); 436 struct net_device *dev = dst->dev; 437 const __be32 *pkey = daddr; 438 439 if (rt->rt_gw_family == AF_INET) { 440 pkey = (const __be32 *)&rt->rt_gw4; 441 } else if (rt->rt_gw_family == AF_INET6) { 442 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 443 } else if (!daddr || 444 (rt->rt_flags & 445 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 446 return; 447 } 448 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 449 } 450 451 /* Hash tables of size 2048..262144 depending on RAM size. 452 * Each bucket uses 8 bytes. 453 */ 454 static u32 ip_idents_mask __read_mostly; 455 static atomic_t *ip_idents __read_mostly; 456 static u32 *ip_tstamps __read_mostly; 457 458 /* In order to protect privacy, we add a perturbation to identifiers 459 * if one generator is seldom used. This makes hard for an attacker 460 * to infer how many packets were sent between two points in time. 461 */ 462 static u32 ip_idents_reserve(u32 hash, int segs) 463 { 464 u32 bucket, old, now = (u32)jiffies; 465 atomic_t *p_id; 466 u32 *p_tstamp; 467 u32 delta = 0; 468 469 bucket = hash & ip_idents_mask; 470 p_tstamp = ip_tstamps + bucket; 471 p_id = ip_idents + bucket; 472 old = READ_ONCE(*p_tstamp); 473 474 if (old != now && cmpxchg(p_tstamp, old, now) == old) 475 delta = get_random_u32_below(now - old); 476 477 /* If UBSAN reports an error there, please make sure your compiler 478 * supports -fno-strict-overflow before reporting it that was a bug 479 * in UBSAN, and it has been fixed in GCC-8. 480 */ 481 return atomic_add_return(segs + delta, p_id) - segs; 482 } 483 484 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 485 { 486 u32 hash, id; 487 488 /* Note the following code is not safe, but this is okay. */ 489 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 490 get_random_bytes(&net->ipv4.ip_id_key, 491 sizeof(net->ipv4.ip_id_key)); 492 493 hash = siphash_3u32((__force u32)iph->daddr, 494 (__force u32)iph->saddr, 495 iph->protocol, 496 &net->ipv4.ip_id_key); 497 id = ip_idents_reserve(hash, segs); 498 iph->id = htons(id); 499 } 500 EXPORT_SYMBOL(__ip_select_ident); 501 502 static void ip_rt_fix_tos(struct flowi4 *fl4) 503 { 504 __u8 tos = RT_FL_TOS(fl4); 505 506 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 507 if (tos & RTO_ONLINK) 508 fl4->flowi4_scope = RT_SCOPE_LINK; 509 } 510 511 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 512 const struct sock *sk, const struct iphdr *iph, 513 int oif, __u8 tos, u8 prot, u32 mark, 514 int flow_flags) 515 { 516 __u8 scope = RT_SCOPE_UNIVERSE; 517 518 if (sk) { 519 oif = sk->sk_bound_dev_if; 520 mark = READ_ONCE(sk->sk_mark); 521 tos = ip_sock_rt_tos(sk); 522 scope = ip_sock_rt_scope(sk); 523 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 524 sk->sk_protocol; 525 } 526 527 flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope, 528 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 529 sock_net_uid(net, sk)); 530 } 531 532 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 533 const struct sock *sk) 534 { 535 const struct net *net = dev_net(skb->dev); 536 const struct iphdr *iph = ip_hdr(skb); 537 int oif = skb->dev->ifindex; 538 u8 prot = iph->protocol; 539 u32 mark = skb->mark; 540 __u8 tos = iph->tos; 541 542 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 543 } 544 545 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 546 { 547 const struct inet_sock *inet = inet_sk(sk); 548 const struct ip_options_rcu *inet_opt; 549 __be32 daddr = inet->inet_daddr; 550 551 rcu_read_lock(); 552 inet_opt = rcu_dereference(inet->inet_opt); 553 if (inet_opt && inet_opt->opt.srr) 554 daddr = inet_opt->opt.faddr; 555 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 556 ip_sock_rt_tos(sk) & IPTOS_RT_MASK, 557 ip_sock_rt_scope(sk), 558 inet_test_bit(HDRINCL, sk) ? 559 IPPROTO_RAW : sk->sk_protocol, 560 inet_sk_flowi_flags(sk), 561 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 562 rcu_read_unlock(); 563 } 564 565 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 566 const struct sk_buff *skb) 567 { 568 if (skb) 569 build_skb_flow_key(fl4, skb, sk); 570 else 571 build_sk_flow_key(fl4, sk); 572 } 573 574 static DEFINE_SPINLOCK(fnhe_lock); 575 576 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 577 { 578 struct rtable *rt; 579 580 rt = rcu_dereference(fnhe->fnhe_rth_input); 581 if (rt) { 582 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 583 dst_dev_put(&rt->dst); 584 dst_release(&rt->dst); 585 } 586 rt = rcu_dereference(fnhe->fnhe_rth_output); 587 if (rt) { 588 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 589 dst_dev_put(&rt->dst); 590 dst_release(&rt->dst); 591 } 592 } 593 594 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 595 { 596 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 597 struct fib_nh_exception *fnhe, *oldest = NULL; 598 599 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 600 fnhe = rcu_dereference_protected(*fnhe_p, 601 lockdep_is_held(&fnhe_lock)); 602 if (!fnhe) 603 break; 604 if (!oldest || 605 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 606 oldest = fnhe; 607 oldest_p = fnhe_p; 608 } 609 } 610 fnhe_flush_routes(oldest); 611 *oldest_p = oldest->fnhe_next; 612 kfree_rcu(oldest, rcu); 613 } 614 615 static u32 fnhe_hashfun(__be32 daddr) 616 { 617 static siphash_aligned_key_t fnhe_hash_key; 618 u64 hval; 619 620 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 621 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 622 return hash_64(hval, FNHE_HASH_SHIFT); 623 } 624 625 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 626 { 627 rt->rt_pmtu = fnhe->fnhe_pmtu; 628 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 629 rt->dst.expires = fnhe->fnhe_expires; 630 631 if (fnhe->fnhe_gw) { 632 rt->rt_flags |= RTCF_REDIRECTED; 633 rt->rt_uses_gateway = 1; 634 rt->rt_gw_family = AF_INET; 635 rt->rt_gw4 = fnhe->fnhe_gw; 636 } 637 } 638 639 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 640 __be32 gw, u32 pmtu, bool lock, 641 unsigned long expires) 642 { 643 struct fnhe_hash_bucket *hash; 644 struct fib_nh_exception *fnhe; 645 struct rtable *rt; 646 u32 genid, hval; 647 unsigned int i; 648 int depth; 649 650 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 651 hval = fnhe_hashfun(daddr); 652 653 spin_lock_bh(&fnhe_lock); 654 655 hash = rcu_dereference(nhc->nhc_exceptions); 656 if (!hash) { 657 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 658 if (!hash) 659 goto out_unlock; 660 rcu_assign_pointer(nhc->nhc_exceptions, hash); 661 } 662 663 hash += hval; 664 665 depth = 0; 666 for (fnhe = rcu_dereference(hash->chain); fnhe; 667 fnhe = rcu_dereference(fnhe->fnhe_next)) { 668 if (fnhe->fnhe_daddr == daddr) 669 break; 670 depth++; 671 } 672 673 if (fnhe) { 674 if (fnhe->fnhe_genid != genid) 675 fnhe->fnhe_genid = genid; 676 if (gw) 677 fnhe->fnhe_gw = gw; 678 if (pmtu) { 679 fnhe->fnhe_pmtu = pmtu; 680 fnhe->fnhe_mtu_locked = lock; 681 } 682 fnhe->fnhe_expires = max(1UL, expires); 683 /* Update all cached dsts too */ 684 rt = rcu_dereference(fnhe->fnhe_rth_input); 685 if (rt) 686 fill_route_from_fnhe(rt, fnhe); 687 rt = rcu_dereference(fnhe->fnhe_rth_output); 688 if (rt) 689 fill_route_from_fnhe(rt, fnhe); 690 } else { 691 /* Randomize max depth to avoid some side channels attacks. */ 692 int max_depth = FNHE_RECLAIM_DEPTH + 693 get_random_u32_below(FNHE_RECLAIM_DEPTH); 694 695 while (depth > max_depth) { 696 fnhe_remove_oldest(hash); 697 depth--; 698 } 699 700 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 701 if (!fnhe) 702 goto out_unlock; 703 704 fnhe->fnhe_next = hash->chain; 705 706 fnhe->fnhe_genid = genid; 707 fnhe->fnhe_daddr = daddr; 708 fnhe->fnhe_gw = gw; 709 fnhe->fnhe_pmtu = pmtu; 710 fnhe->fnhe_mtu_locked = lock; 711 fnhe->fnhe_expires = max(1UL, expires); 712 713 rcu_assign_pointer(hash->chain, fnhe); 714 715 /* Exception created; mark the cached routes for the nexthop 716 * stale, so anyone caching it rechecks if this exception 717 * applies to them. 718 */ 719 rt = rcu_dereference(nhc->nhc_rth_input); 720 if (rt) 721 rt->dst.obsolete = DST_OBSOLETE_KILL; 722 723 for_each_possible_cpu(i) { 724 struct rtable __rcu **prt; 725 726 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 727 rt = rcu_dereference(*prt); 728 if (rt) 729 rt->dst.obsolete = DST_OBSOLETE_KILL; 730 } 731 } 732 733 fnhe->fnhe_stamp = jiffies; 734 735 out_unlock: 736 spin_unlock_bh(&fnhe_lock); 737 } 738 739 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 740 bool kill_route) 741 { 742 __be32 new_gw = icmp_hdr(skb)->un.gateway; 743 __be32 old_gw = ip_hdr(skb)->saddr; 744 struct net_device *dev = skb->dev; 745 struct in_device *in_dev; 746 struct fib_result res; 747 struct neighbour *n; 748 struct net *net; 749 750 switch (icmp_hdr(skb)->code & 7) { 751 case ICMP_REDIR_NET: 752 case ICMP_REDIR_NETTOS: 753 case ICMP_REDIR_HOST: 754 case ICMP_REDIR_HOSTTOS: 755 break; 756 757 default: 758 return; 759 } 760 761 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 762 return; 763 764 in_dev = __in_dev_get_rcu(dev); 765 if (!in_dev) 766 return; 767 768 net = dev_net(dev); 769 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 770 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 771 ipv4_is_zeronet(new_gw)) 772 goto reject_redirect; 773 774 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 775 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 776 goto reject_redirect; 777 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 778 goto reject_redirect; 779 } else { 780 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 781 goto reject_redirect; 782 } 783 784 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 785 if (!n) 786 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 787 if (!IS_ERR(n)) { 788 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 789 neigh_event_send(n, NULL); 790 } else { 791 if (fib_lookup(net, fl4, &res, 0) == 0) { 792 struct fib_nh_common *nhc; 793 794 fib_select_path(net, &res, fl4, skb); 795 nhc = FIB_RES_NHC(res); 796 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 797 0, false, 798 jiffies + ip_rt_gc_timeout); 799 } 800 if (kill_route) 801 rt->dst.obsolete = DST_OBSOLETE_KILL; 802 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 803 } 804 neigh_release(n); 805 } 806 return; 807 808 reject_redirect: 809 #ifdef CONFIG_IP_ROUTE_VERBOSE 810 if (IN_DEV_LOG_MARTIANS(in_dev)) { 811 const struct iphdr *iph = (const struct iphdr *) skb->data; 812 __be32 daddr = iph->daddr; 813 __be32 saddr = iph->saddr; 814 815 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 816 " Advised path = %pI4 -> %pI4\n", 817 &old_gw, dev->name, &new_gw, 818 &saddr, &daddr); 819 } 820 #endif 821 ; 822 } 823 824 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 825 { 826 struct rtable *rt; 827 struct flowi4 fl4; 828 const struct iphdr *iph = (const struct iphdr *) skb->data; 829 struct net *net = dev_net(skb->dev); 830 int oif = skb->dev->ifindex; 831 u8 prot = iph->protocol; 832 u32 mark = skb->mark; 833 __u8 tos = iph->tos; 834 835 rt = (struct rtable *) dst; 836 837 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 838 __ip_do_redirect(rt, skb, &fl4, true); 839 } 840 841 static void ipv4_negative_advice(struct sock *sk, 842 struct dst_entry *dst) 843 { 844 struct rtable *rt = (struct rtable *)dst; 845 846 if ((dst->obsolete > 0) || 847 (rt->rt_flags & RTCF_REDIRECTED) || 848 rt->dst.expires) 849 sk_dst_reset(sk); 850 } 851 852 /* 853 * Algorithm: 854 * 1. The first ip_rt_redirect_number redirects are sent 855 * with exponential backoff, then we stop sending them at all, 856 * assuming that the host ignores our redirects. 857 * 2. If we did not see packets requiring redirects 858 * during ip_rt_redirect_silence, we assume that the host 859 * forgot redirected route and start to send redirects again. 860 * 861 * This algorithm is much cheaper and more intelligent than dumb load limiting 862 * in icmp.c. 863 * 864 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 865 * and "frag. need" (breaks PMTU discovery) in icmp.c. 866 */ 867 868 void ip_rt_send_redirect(struct sk_buff *skb) 869 { 870 struct rtable *rt = skb_rtable(skb); 871 struct in_device *in_dev; 872 struct inet_peer *peer; 873 struct net *net; 874 int log_martians; 875 int vif; 876 877 rcu_read_lock(); 878 in_dev = __in_dev_get_rcu(rt->dst.dev); 879 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 880 rcu_read_unlock(); 881 return; 882 } 883 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 884 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 885 rcu_read_unlock(); 886 887 net = dev_net(rt->dst.dev); 888 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 889 if (!peer) { 890 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 891 rt_nexthop(rt, ip_hdr(skb)->daddr)); 892 return; 893 } 894 895 /* No redirected packets during ip_rt_redirect_silence; 896 * reset the algorithm. 897 */ 898 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 899 peer->rate_tokens = 0; 900 peer->n_redirects = 0; 901 } 902 903 /* Too many ignored redirects; do not send anything 904 * set dst.rate_last to the last seen redirected packet. 905 */ 906 if (peer->n_redirects >= ip_rt_redirect_number) { 907 peer->rate_last = jiffies; 908 goto out_put_peer; 909 } 910 911 /* Check for load limit; set rate_last to the latest sent 912 * redirect. 913 */ 914 if (peer->n_redirects == 0 || 915 time_after(jiffies, 916 (peer->rate_last + 917 (ip_rt_redirect_load << peer->n_redirects)))) { 918 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 919 920 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 921 peer->rate_last = jiffies; 922 ++peer->n_redirects; 923 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 924 peer->n_redirects == ip_rt_redirect_number) 925 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 926 &ip_hdr(skb)->saddr, inet_iif(skb), 927 &ip_hdr(skb)->daddr, &gw); 928 } 929 out_put_peer: 930 inet_putpeer(peer); 931 } 932 933 static int ip_error(struct sk_buff *skb) 934 { 935 struct rtable *rt = skb_rtable(skb); 936 struct net_device *dev = skb->dev; 937 struct in_device *in_dev; 938 struct inet_peer *peer; 939 unsigned long now; 940 struct net *net; 941 SKB_DR(reason); 942 bool send; 943 int code; 944 945 if (netif_is_l3_master(skb->dev)) { 946 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 947 if (!dev) 948 goto out; 949 } 950 951 in_dev = __in_dev_get_rcu(dev); 952 953 /* IP on this device is disabled. */ 954 if (!in_dev) 955 goto out; 956 957 net = dev_net(rt->dst.dev); 958 if (!IN_DEV_FORWARD(in_dev)) { 959 switch (rt->dst.error) { 960 case EHOSTUNREACH: 961 SKB_DR_SET(reason, IP_INADDRERRORS); 962 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 963 break; 964 965 case ENETUNREACH: 966 SKB_DR_SET(reason, IP_INNOROUTES); 967 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 968 break; 969 } 970 goto out; 971 } 972 973 switch (rt->dst.error) { 974 case EINVAL: 975 default: 976 goto out; 977 case EHOSTUNREACH: 978 code = ICMP_HOST_UNREACH; 979 break; 980 case ENETUNREACH: 981 code = ICMP_NET_UNREACH; 982 SKB_DR_SET(reason, IP_INNOROUTES); 983 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 984 break; 985 case EACCES: 986 code = ICMP_PKT_FILTERED; 987 break; 988 } 989 990 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 991 l3mdev_master_ifindex(skb->dev), 1); 992 993 send = true; 994 if (peer) { 995 now = jiffies; 996 peer->rate_tokens += now - peer->rate_last; 997 if (peer->rate_tokens > ip_rt_error_burst) 998 peer->rate_tokens = ip_rt_error_burst; 999 peer->rate_last = now; 1000 if (peer->rate_tokens >= ip_rt_error_cost) 1001 peer->rate_tokens -= ip_rt_error_cost; 1002 else 1003 send = false; 1004 inet_putpeer(peer); 1005 } 1006 if (send) 1007 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1008 1009 out: kfree_skb_reason(skb, reason); 1010 return 0; 1011 } 1012 1013 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1014 { 1015 struct dst_entry *dst = &rt->dst; 1016 struct net *net = dev_net(dst->dev); 1017 struct fib_result res; 1018 bool lock = false; 1019 u32 old_mtu; 1020 1021 if (ip_mtu_locked(dst)) 1022 return; 1023 1024 old_mtu = ipv4_mtu(dst); 1025 if (old_mtu < mtu) 1026 return; 1027 1028 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1029 lock = true; 1030 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1031 } 1032 1033 if (rt->rt_pmtu == mtu && !lock && 1034 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1035 return; 1036 1037 rcu_read_lock(); 1038 if (fib_lookup(net, fl4, &res, 0) == 0) { 1039 struct fib_nh_common *nhc; 1040 1041 fib_select_path(net, &res, fl4, NULL); 1042 nhc = FIB_RES_NHC(res); 1043 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1044 jiffies + net->ipv4.ip_rt_mtu_expires); 1045 } 1046 rcu_read_unlock(); 1047 } 1048 1049 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1050 struct sk_buff *skb, u32 mtu, 1051 bool confirm_neigh) 1052 { 1053 struct rtable *rt = (struct rtable *) dst; 1054 struct flowi4 fl4; 1055 1056 ip_rt_build_flow_key(&fl4, sk, skb); 1057 1058 /* Don't make lookup fail for bridged encapsulations */ 1059 if (skb && netif_is_any_bridge_port(skb->dev)) 1060 fl4.flowi4_oif = 0; 1061 1062 __ip_rt_update_pmtu(rt, &fl4, mtu); 1063 } 1064 1065 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1066 int oif, u8 protocol) 1067 { 1068 const struct iphdr *iph = (const struct iphdr *)skb->data; 1069 struct flowi4 fl4; 1070 struct rtable *rt; 1071 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1072 1073 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1074 0); 1075 rt = __ip_route_output_key(net, &fl4); 1076 if (!IS_ERR(rt)) { 1077 __ip_rt_update_pmtu(rt, &fl4, mtu); 1078 ip_rt_put(rt); 1079 } 1080 } 1081 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1082 1083 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1084 { 1085 const struct iphdr *iph = (const struct iphdr *)skb->data; 1086 struct flowi4 fl4; 1087 struct rtable *rt; 1088 1089 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1090 1091 if (!fl4.flowi4_mark) 1092 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1093 1094 rt = __ip_route_output_key(sock_net(sk), &fl4); 1095 if (!IS_ERR(rt)) { 1096 __ip_rt_update_pmtu(rt, &fl4, mtu); 1097 ip_rt_put(rt); 1098 } 1099 } 1100 1101 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1102 { 1103 const struct iphdr *iph = (const struct iphdr *)skb->data; 1104 struct flowi4 fl4; 1105 struct rtable *rt; 1106 struct dst_entry *odst = NULL; 1107 bool new = false; 1108 struct net *net = sock_net(sk); 1109 1110 bh_lock_sock(sk); 1111 1112 if (!ip_sk_accept_pmtu(sk)) 1113 goto out; 1114 1115 odst = sk_dst_get(sk); 1116 1117 if (sock_owned_by_user(sk) || !odst) { 1118 __ipv4_sk_update_pmtu(skb, sk, mtu); 1119 goto out; 1120 } 1121 1122 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1123 1124 rt = (struct rtable *)odst; 1125 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1126 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1127 if (IS_ERR(rt)) 1128 goto out; 1129 1130 new = true; 1131 } 1132 1133 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1134 1135 if (!dst_check(&rt->dst, 0)) { 1136 if (new) 1137 dst_release(&rt->dst); 1138 1139 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1140 if (IS_ERR(rt)) 1141 goto out; 1142 1143 new = true; 1144 } 1145 1146 if (new) 1147 sk_dst_set(sk, &rt->dst); 1148 1149 out: 1150 bh_unlock_sock(sk); 1151 dst_release(odst); 1152 } 1153 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1154 1155 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1156 int oif, u8 protocol) 1157 { 1158 const struct iphdr *iph = (const struct iphdr *)skb->data; 1159 struct flowi4 fl4; 1160 struct rtable *rt; 1161 1162 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1163 rt = __ip_route_output_key(net, &fl4); 1164 if (!IS_ERR(rt)) { 1165 __ip_do_redirect(rt, skb, &fl4, false); 1166 ip_rt_put(rt); 1167 } 1168 } 1169 EXPORT_SYMBOL_GPL(ipv4_redirect); 1170 1171 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1172 { 1173 const struct iphdr *iph = (const struct iphdr *)skb->data; 1174 struct flowi4 fl4; 1175 struct rtable *rt; 1176 struct net *net = sock_net(sk); 1177 1178 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1179 rt = __ip_route_output_key(net, &fl4); 1180 if (!IS_ERR(rt)) { 1181 __ip_do_redirect(rt, skb, &fl4, false); 1182 ip_rt_put(rt); 1183 } 1184 } 1185 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1186 1187 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1188 u32 cookie) 1189 { 1190 struct rtable *rt = (struct rtable *) dst; 1191 1192 /* All IPV4 dsts are created with ->obsolete set to the value 1193 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1194 * into this function always. 1195 * 1196 * When a PMTU/redirect information update invalidates a route, 1197 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1198 * DST_OBSOLETE_DEAD. 1199 */ 1200 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1201 return NULL; 1202 return dst; 1203 } 1204 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1205 1206 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1207 { 1208 struct net_device *dev; 1209 struct ip_options opt; 1210 int res; 1211 1212 /* Recompile ip options since IPCB may not be valid anymore. 1213 * Also check we have a reasonable ipv4 header. 1214 */ 1215 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1216 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1217 return; 1218 1219 memset(&opt, 0, sizeof(opt)); 1220 if (ip_hdr(skb)->ihl > 5) { 1221 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1222 return; 1223 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1224 1225 rcu_read_lock(); 1226 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1227 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); 1228 rcu_read_unlock(); 1229 1230 if (res) 1231 return; 1232 } 1233 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1234 } 1235 1236 static void ipv4_link_failure(struct sk_buff *skb) 1237 { 1238 struct rtable *rt; 1239 1240 ipv4_send_dest_unreach(skb); 1241 1242 rt = skb_rtable(skb); 1243 if (rt) 1244 dst_set_expires(&rt->dst, 0); 1245 } 1246 1247 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1248 { 1249 pr_debug("%s: %pI4 -> %pI4, %s\n", 1250 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1251 skb->dev ? skb->dev->name : "?"); 1252 kfree_skb(skb); 1253 WARN_ON(1); 1254 return 0; 1255 } 1256 1257 /* 1258 * We do not cache source address of outgoing interface, 1259 * because it is used only by IP RR, TS and SRR options, 1260 * so that it out of fast path. 1261 * 1262 * BTW remember: "addr" is allowed to be not aligned 1263 * in IP options! 1264 */ 1265 1266 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1267 { 1268 __be32 src; 1269 1270 if (rt_is_output_route(rt)) 1271 src = ip_hdr(skb)->saddr; 1272 else { 1273 struct fib_result res; 1274 struct iphdr *iph = ip_hdr(skb); 1275 struct flowi4 fl4 = { 1276 .daddr = iph->daddr, 1277 .saddr = iph->saddr, 1278 .flowi4_tos = iph->tos & IPTOS_RT_MASK, 1279 .flowi4_oif = rt->dst.dev->ifindex, 1280 .flowi4_iif = skb->dev->ifindex, 1281 .flowi4_mark = skb->mark, 1282 }; 1283 1284 rcu_read_lock(); 1285 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1286 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1287 else 1288 src = inet_select_addr(rt->dst.dev, 1289 rt_nexthop(rt, iph->daddr), 1290 RT_SCOPE_UNIVERSE); 1291 rcu_read_unlock(); 1292 } 1293 memcpy(addr, &src, 4); 1294 } 1295 1296 #ifdef CONFIG_IP_ROUTE_CLASSID 1297 static void set_class_tag(struct rtable *rt, u32 tag) 1298 { 1299 if (!(rt->dst.tclassid & 0xFFFF)) 1300 rt->dst.tclassid |= tag & 0xFFFF; 1301 if (!(rt->dst.tclassid & 0xFFFF0000)) 1302 rt->dst.tclassid |= tag & 0xFFFF0000; 1303 } 1304 #endif 1305 1306 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1307 { 1308 struct net *net = dev_net(dst->dev); 1309 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1310 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1311 net->ipv4.ip_rt_min_advmss); 1312 1313 return min(advmss, IPV4_MAX_PMTU - header_size); 1314 } 1315 1316 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1317 { 1318 return ip_dst_mtu_maybe_forward(dst, false); 1319 } 1320 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1321 1322 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1323 { 1324 struct fnhe_hash_bucket *hash; 1325 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1326 u32 hval = fnhe_hashfun(daddr); 1327 1328 spin_lock_bh(&fnhe_lock); 1329 1330 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1331 lockdep_is_held(&fnhe_lock)); 1332 hash += hval; 1333 1334 fnhe_p = &hash->chain; 1335 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1336 while (fnhe) { 1337 if (fnhe->fnhe_daddr == daddr) { 1338 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1339 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1340 /* set fnhe_daddr to 0 to ensure it won't bind with 1341 * new dsts in rt_bind_exception(). 1342 */ 1343 fnhe->fnhe_daddr = 0; 1344 fnhe_flush_routes(fnhe); 1345 kfree_rcu(fnhe, rcu); 1346 break; 1347 } 1348 fnhe_p = &fnhe->fnhe_next; 1349 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1350 lockdep_is_held(&fnhe_lock)); 1351 } 1352 1353 spin_unlock_bh(&fnhe_lock); 1354 } 1355 1356 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1357 __be32 daddr) 1358 { 1359 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1360 struct fib_nh_exception *fnhe; 1361 u32 hval; 1362 1363 if (!hash) 1364 return NULL; 1365 1366 hval = fnhe_hashfun(daddr); 1367 1368 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1369 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1370 if (fnhe->fnhe_daddr == daddr) { 1371 if (fnhe->fnhe_expires && 1372 time_after(jiffies, fnhe->fnhe_expires)) { 1373 ip_del_fnhe(nhc, daddr); 1374 break; 1375 } 1376 return fnhe; 1377 } 1378 } 1379 return NULL; 1380 } 1381 1382 /* MTU selection: 1383 * 1. mtu on route is locked - use it 1384 * 2. mtu from nexthop exception 1385 * 3. mtu from egress device 1386 */ 1387 1388 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1389 { 1390 struct fib_nh_common *nhc = res->nhc; 1391 struct net_device *dev = nhc->nhc_dev; 1392 struct fib_info *fi = res->fi; 1393 u32 mtu = 0; 1394 1395 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1396 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1397 mtu = fi->fib_mtu; 1398 1399 if (likely(!mtu)) { 1400 struct fib_nh_exception *fnhe; 1401 1402 fnhe = find_exception(nhc, daddr); 1403 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1404 mtu = fnhe->fnhe_pmtu; 1405 } 1406 1407 if (likely(!mtu)) 1408 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1409 1410 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1411 } 1412 1413 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1414 __be32 daddr, const bool do_cache) 1415 { 1416 bool ret = false; 1417 1418 spin_lock_bh(&fnhe_lock); 1419 1420 if (daddr == fnhe->fnhe_daddr) { 1421 struct rtable __rcu **porig; 1422 struct rtable *orig; 1423 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1424 1425 if (rt_is_input_route(rt)) 1426 porig = &fnhe->fnhe_rth_input; 1427 else 1428 porig = &fnhe->fnhe_rth_output; 1429 orig = rcu_dereference(*porig); 1430 1431 if (fnhe->fnhe_genid != genid) { 1432 fnhe->fnhe_genid = genid; 1433 fnhe->fnhe_gw = 0; 1434 fnhe->fnhe_pmtu = 0; 1435 fnhe->fnhe_expires = 0; 1436 fnhe->fnhe_mtu_locked = false; 1437 fnhe_flush_routes(fnhe); 1438 orig = NULL; 1439 } 1440 fill_route_from_fnhe(rt, fnhe); 1441 if (!rt->rt_gw4) { 1442 rt->rt_gw4 = daddr; 1443 rt->rt_gw_family = AF_INET; 1444 } 1445 1446 if (do_cache) { 1447 dst_hold(&rt->dst); 1448 rcu_assign_pointer(*porig, rt); 1449 if (orig) { 1450 dst_dev_put(&orig->dst); 1451 dst_release(&orig->dst); 1452 } 1453 ret = true; 1454 } 1455 1456 fnhe->fnhe_stamp = jiffies; 1457 } 1458 spin_unlock_bh(&fnhe_lock); 1459 1460 return ret; 1461 } 1462 1463 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1464 { 1465 struct rtable *orig, *prev, **p; 1466 bool ret = true; 1467 1468 if (rt_is_input_route(rt)) { 1469 p = (struct rtable **)&nhc->nhc_rth_input; 1470 } else { 1471 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1472 } 1473 orig = *p; 1474 1475 /* hold dst before doing cmpxchg() to avoid race condition 1476 * on this dst 1477 */ 1478 dst_hold(&rt->dst); 1479 prev = cmpxchg(p, orig, rt); 1480 if (prev == orig) { 1481 if (orig) { 1482 rt_add_uncached_list(orig); 1483 dst_release(&orig->dst); 1484 } 1485 } else { 1486 dst_release(&rt->dst); 1487 ret = false; 1488 } 1489 1490 return ret; 1491 } 1492 1493 struct uncached_list { 1494 spinlock_t lock; 1495 struct list_head head; 1496 struct list_head quarantine; 1497 }; 1498 1499 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1500 1501 void rt_add_uncached_list(struct rtable *rt) 1502 { 1503 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1504 1505 rt->dst.rt_uncached_list = ul; 1506 1507 spin_lock_bh(&ul->lock); 1508 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1509 spin_unlock_bh(&ul->lock); 1510 } 1511 1512 void rt_del_uncached_list(struct rtable *rt) 1513 { 1514 if (!list_empty(&rt->dst.rt_uncached)) { 1515 struct uncached_list *ul = rt->dst.rt_uncached_list; 1516 1517 spin_lock_bh(&ul->lock); 1518 list_del_init(&rt->dst.rt_uncached); 1519 spin_unlock_bh(&ul->lock); 1520 } 1521 } 1522 1523 static void ipv4_dst_destroy(struct dst_entry *dst) 1524 { 1525 struct rtable *rt = (struct rtable *)dst; 1526 1527 ip_dst_metrics_put(dst); 1528 rt_del_uncached_list(rt); 1529 } 1530 1531 void rt_flush_dev(struct net_device *dev) 1532 { 1533 struct rtable *rt, *safe; 1534 int cpu; 1535 1536 for_each_possible_cpu(cpu) { 1537 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1538 1539 if (list_empty(&ul->head)) 1540 continue; 1541 1542 spin_lock_bh(&ul->lock); 1543 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1544 if (rt->dst.dev != dev) 1545 continue; 1546 rt->dst.dev = blackhole_netdev; 1547 netdev_ref_replace(dev, blackhole_netdev, 1548 &rt->dst.dev_tracker, GFP_ATOMIC); 1549 list_move(&rt->dst.rt_uncached, &ul->quarantine); 1550 } 1551 spin_unlock_bh(&ul->lock); 1552 } 1553 } 1554 1555 static bool rt_cache_valid(const struct rtable *rt) 1556 { 1557 return rt && 1558 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1559 !rt_is_expired(rt); 1560 } 1561 1562 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1563 const struct fib_result *res, 1564 struct fib_nh_exception *fnhe, 1565 struct fib_info *fi, u16 type, u32 itag, 1566 const bool do_cache) 1567 { 1568 bool cached = false; 1569 1570 if (fi) { 1571 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1572 1573 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1574 rt->rt_uses_gateway = 1; 1575 rt->rt_gw_family = nhc->nhc_gw_family; 1576 /* only INET and INET6 are supported */ 1577 if (likely(nhc->nhc_gw_family == AF_INET)) 1578 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1579 else 1580 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1581 } 1582 1583 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1584 1585 #ifdef CONFIG_IP_ROUTE_CLASSID 1586 if (nhc->nhc_family == AF_INET) { 1587 struct fib_nh *nh; 1588 1589 nh = container_of(nhc, struct fib_nh, nh_common); 1590 rt->dst.tclassid = nh->nh_tclassid; 1591 } 1592 #endif 1593 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1594 if (unlikely(fnhe)) 1595 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1596 else if (do_cache) 1597 cached = rt_cache_route(nhc, rt); 1598 if (unlikely(!cached)) { 1599 /* Routes we intend to cache in nexthop exception or 1600 * FIB nexthop have the DST_NOCACHE bit clear. 1601 * However, if we are unsuccessful at storing this 1602 * route into the cache we really need to set it. 1603 */ 1604 if (!rt->rt_gw4) { 1605 rt->rt_gw_family = AF_INET; 1606 rt->rt_gw4 = daddr; 1607 } 1608 rt_add_uncached_list(rt); 1609 } 1610 } else 1611 rt_add_uncached_list(rt); 1612 1613 #ifdef CONFIG_IP_ROUTE_CLASSID 1614 #ifdef CONFIG_IP_MULTIPLE_TABLES 1615 set_class_tag(rt, res->tclassid); 1616 #endif 1617 set_class_tag(rt, itag); 1618 #endif 1619 } 1620 1621 struct rtable *rt_dst_alloc(struct net_device *dev, 1622 unsigned int flags, u16 type, 1623 bool noxfrm) 1624 { 1625 struct rtable *rt; 1626 1627 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1628 (noxfrm ? DST_NOXFRM : 0)); 1629 1630 if (rt) { 1631 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1632 rt->rt_flags = flags; 1633 rt->rt_type = type; 1634 rt->rt_is_input = 0; 1635 rt->rt_iif = 0; 1636 rt->rt_pmtu = 0; 1637 rt->rt_mtu_locked = 0; 1638 rt->rt_uses_gateway = 0; 1639 rt->rt_gw_family = 0; 1640 rt->rt_gw4 = 0; 1641 1642 rt->dst.output = ip_output; 1643 if (flags & RTCF_LOCAL) 1644 rt->dst.input = ip_local_deliver; 1645 } 1646 1647 return rt; 1648 } 1649 EXPORT_SYMBOL(rt_dst_alloc); 1650 1651 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1652 { 1653 struct rtable *new_rt; 1654 1655 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1656 rt->dst.flags); 1657 1658 if (new_rt) { 1659 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1660 new_rt->rt_flags = rt->rt_flags; 1661 new_rt->rt_type = rt->rt_type; 1662 new_rt->rt_is_input = rt->rt_is_input; 1663 new_rt->rt_iif = rt->rt_iif; 1664 new_rt->rt_pmtu = rt->rt_pmtu; 1665 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1666 new_rt->rt_gw_family = rt->rt_gw_family; 1667 if (rt->rt_gw_family == AF_INET) 1668 new_rt->rt_gw4 = rt->rt_gw4; 1669 else if (rt->rt_gw_family == AF_INET6) 1670 new_rt->rt_gw6 = rt->rt_gw6; 1671 1672 new_rt->dst.input = rt->dst.input; 1673 new_rt->dst.output = rt->dst.output; 1674 new_rt->dst.error = rt->dst.error; 1675 new_rt->dst.lastuse = jiffies; 1676 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1677 } 1678 return new_rt; 1679 } 1680 EXPORT_SYMBOL(rt_dst_clone); 1681 1682 /* called in rcu_read_lock() section */ 1683 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1684 u8 tos, struct net_device *dev, 1685 struct in_device *in_dev, u32 *itag) 1686 { 1687 int err; 1688 1689 /* Primary sanity checks. */ 1690 if (!in_dev) 1691 return -EINVAL; 1692 1693 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1694 skb->protocol != htons(ETH_P_IP)) 1695 return -EINVAL; 1696 1697 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1698 return -EINVAL; 1699 1700 if (ipv4_is_zeronet(saddr)) { 1701 if (!ipv4_is_local_multicast(daddr) && 1702 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1703 return -EINVAL; 1704 } else { 1705 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1706 in_dev, itag); 1707 if (err < 0) 1708 return err; 1709 } 1710 return 0; 1711 } 1712 1713 /* called in rcu_read_lock() section */ 1714 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1715 u8 tos, struct net_device *dev, int our) 1716 { 1717 struct in_device *in_dev = __in_dev_get_rcu(dev); 1718 unsigned int flags = RTCF_MULTICAST; 1719 struct rtable *rth; 1720 u32 itag = 0; 1721 int err; 1722 1723 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1724 if (err) 1725 return err; 1726 1727 if (our) 1728 flags |= RTCF_LOCAL; 1729 1730 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1731 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1732 1733 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1734 false); 1735 if (!rth) 1736 return -ENOBUFS; 1737 1738 #ifdef CONFIG_IP_ROUTE_CLASSID 1739 rth->dst.tclassid = itag; 1740 #endif 1741 rth->dst.output = ip_rt_bug; 1742 rth->rt_is_input= 1; 1743 1744 #ifdef CONFIG_IP_MROUTE 1745 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1746 rth->dst.input = ip_mr_input; 1747 #endif 1748 RT_CACHE_STAT_INC(in_slow_mc); 1749 1750 skb_dst_drop(skb); 1751 skb_dst_set(skb, &rth->dst); 1752 return 0; 1753 } 1754 1755 1756 static void ip_handle_martian_source(struct net_device *dev, 1757 struct in_device *in_dev, 1758 struct sk_buff *skb, 1759 __be32 daddr, 1760 __be32 saddr) 1761 { 1762 RT_CACHE_STAT_INC(in_martian_src); 1763 #ifdef CONFIG_IP_ROUTE_VERBOSE 1764 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1765 /* 1766 * RFC1812 recommendation, if source is martian, 1767 * the only hint is MAC header. 1768 */ 1769 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1770 &daddr, &saddr, dev->name); 1771 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1772 print_hex_dump(KERN_WARNING, "ll header: ", 1773 DUMP_PREFIX_OFFSET, 16, 1, 1774 skb_mac_header(skb), 1775 dev->hard_header_len, false); 1776 } 1777 } 1778 #endif 1779 } 1780 1781 /* called in rcu_read_lock() section */ 1782 static int __mkroute_input(struct sk_buff *skb, 1783 const struct fib_result *res, 1784 struct in_device *in_dev, 1785 __be32 daddr, __be32 saddr, u32 tos) 1786 { 1787 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1788 struct net_device *dev = nhc->nhc_dev; 1789 struct fib_nh_exception *fnhe; 1790 struct rtable *rth; 1791 int err; 1792 struct in_device *out_dev; 1793 bool do_cache; 1794 u32 itag = 0; 1795 1796 /* get a working reference to the output device */ 1797 out_dev = __in_dev_get_rcu(dev); 1798 if (!out_dev) { 1799 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1800 return -EINVAL; 1801 } 1802 1803 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1804 in_dev->dev, in_dev, &itag); 1805 if (err < 0) { 1806 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1807 saddr); 1808 1809 goto cleanup; 1810 } 1811 1812 do_cache = res->fi && !itag; 1813 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1814 skb->protocol == htons(ETH_P_IP)) { 1815 __be32 gw; 1816 1817 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1818 if (IN_DEV_SHARED_MEDIA(out_dev) || 1819 inet_addr_onlink(out_dev, saddr, gw)) 1820 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1821 } 1822 1823 if (skb->protocol != htons(ETH_P_IP)) { 1824 /* Not IP (i.e. ARP). Do not create route, if it is 1825 * invalid for proxy arp. DNAT routes are always valid. 1826 * 1827 * Proxy arp feature have been extended to allow, ARP 1828 * replies back to the same interface, to support 1829 * Private VLAN switch technologies. See arp.c. 1830 */ 1831 if (out_dev == in_dev && 1832 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1833 err = -EINVAL; 1834 goto cleanup; 1835 } 1836 } 1837 1838 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1839 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1840 1841 fnhe = find_exception(nhc, daddr); 1842 if (do_cache) { 1843 if (fnhe) 1844 rth = rcu_dereference(fnhe->fnhe_rth_input); 1845 else 1846 rth = rcu_dereference(nhc->nhc_rth_input); 1847 if (rt_cache_valid(rth)) { 1848 skb_dst_set_noref(skb, &rth->dst); 1849 goto out; 1850 } 1851 } 1852 1853 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1854 IN_DEV_ORCONF(out_dev, NOXFRM)); 1855 if (!rth) { 1856 err = -ENOBUFS; 1857 goto cleanup; 1858 } 1859 1860 rth->rt_is_input = 1; 1861 RT_CACHE_STAT_INC(in_slow_tot); 1862 1863 rth->dst.input = ip_forward; 1864 1865 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1866 do_cache); 1867 lwtunnel_set_redirect(&rth->dst); 1868 skb_dst_set(skb, &rth->dst); 1869 out: 1870 err = 0; 1871 cleanup: 1872 return err; 1873 } 1874 1875 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1876 /* To make ICMP packets follow the right flow, the multipath hash is 1877 * calculated from the inner IP addresses. 1878 */ 1879 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1880 struct flow_keys *hash_keys) 1881 { 1882 const struct iphdr *outer_iph = ip_hdr(skb); 1883 const struct iphdr *key_iph = outer_iph; 1884 const struct iphdr *inner_iph; 1885 const struct icmphdr *icmph; 1886 struct iphdr _inner_iph; 1887 struct icmphdr _icmph; 1888 1889 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1890 goto out; 1891 1892 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1893 goto out; 1894 1895 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1896 &_icmph); 1897 if (!icmph) 1898 goto out; 1899 1900 if (!icmp_is_err(icmph->type)) 1901 goto out; 1902 1903 inner_iph = skb_header_pointer(skb, 1904 outer_iph->ihl * 4 + sizeof(_icmph), 1905 sizeof(_inner_iph), &_inner_iph); 1906 if (!inner_iph) 1907 goto out; 1908 1909 key_iph = inner_iph; 1910 out: 1911 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1912 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1913 } 1914 1915 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1916 const struct sk_buff *skb, 1917 bool *p_has_inner) 1918 { 1919 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1920 struct flow_keys keys, hash_keys; 1921 1922 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1923 return 0; 1924 1925 memset(&hash_keys, 0, sizeof(hash_keys)); 1926 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1927 1928 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1929 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1930 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1931 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1932 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1933 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1934 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1935 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1936 hash_keys.ports.src = keys.ports.src; 1937 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1938 hash_keys.ports.dst = keys.ports.dst; 1939 1940 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1941 return flow_hash_from_keys(&hash_keys); 1942 } 1943 1944 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1945 const struct sk_buff *skb, 1946 bool has_inner) 1947 { 1948 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1949 struct flow_keys keys, hash_keys; 1950 1951 /* We assume the packet carries an encapsulation, but if none was 1952 * encountered during dissection of the outer flow, then there is no 1953 * point in calling the flow dissector again. 1954 */ 1955 if (!has_inner) 1956 return 0; 1957 1958 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1959 return 0; 1960 1961 memset(&hash_keys, 0, sizeof(hash_keys)); 1962 skb_flow_dissect_flow_keys(skb, &keys, 0); 1963 1964 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1965 return 0; 1966 1967 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1968 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1969 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1970 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1971 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1972 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1973 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1974 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1975 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1976 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1977 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1978 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1979 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1980 hash_keys.tags.flow_label = keys.tags.flow_label; 1981 } 1982 1983 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1984 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1985 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1986 hash_keys.ports.src = keys.ports.src; 1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1988 hash_keys.ports.dst = keys.ports.dst; 1989 1990 return flow_hash_from_keys(&hash_keys); 1991 } 1992 1993 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1994 const struct sk_buff *skb) 1995 { 1996 u32 mhash, mhash_inner; 1997 bool has_inner = true; 1998 1999 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2000 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2001 2002 return jhash_2words(mhash, mhash_inner, 0); 2003 } 2004 2005 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2006 const struct flowi4 *fl4) 2007 { 2008 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2009 struct flow_keys hash_keys; 2010 2011 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2012 return 0; 2013 2014 memset(&hash_keys, 0, sizeof(hash_keys)); 2015 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2016 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2017 hash_keys.addrs.v4addrs.src = fl4->saddr; 2018 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2019 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2020 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2021 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2022 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2023 hash_keys.ports.src = fl4->fl4_sport; 2024 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2025 hash_keys.ports.dst = fl4->fl4_dport; 2026 2027 return flow_hash_from_keys(&hash_keys); 2028 } 2029 2030 /* if skb is set it will be used and fl4 can be NULL */ 2031 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2032 const struct sk_buff *skb, struct flow_keys *flkeys) 2033 { 2034 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2035 struct flow_keys hash_keys; 2036 u32 mhash = 0; 2037 2038 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2039 case 0: 2040 memset(&hash_keys, 0, sizeof(hash_keys)); 2041 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2042 if (skb) { 2043 ip_multipath_l3_keys(skb, &hash_keys); 2044 } else { 2045 hash_keys.addrs.v4addrs.src = fl4->saddr; 2046 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2047 } 2048 mhash = flow_hash_from_keys(&hash_keys); 2049 break; 2050 case 1: 2051 /* skb is currently provided only when forwarding */ 2052 if (skb) { 2053 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2054 struct flow_keys keys; 2055 2056 /* short-circuit if we already have L4 hash present */ 2057 if (skb->l4_hash) 2058 return skb_get_hash_raw(skb) >> 1; 2059 2060 memset(&hash_keys, 0, sizeof(hash_keys)); 2061 2062 if (!flkeys) { 2063 skb_flow_dissect_flow_keys(skb, &keys, flag); 2064 flkeys = &keys; 2065 } 2066 2067 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2068 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2069 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2070 hash_keys.ports.src = flkeys->ports.src; 2071 hash_keys.ports.dst = flkeys->ports.dst; 2072 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2073 } else { 2074 memset(&hash_keys, 0, sizeof(hash_keys)); 2075 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2076 hash_keys.addrs.v4addrs.src = fl4->saddr; 2077 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2078 hash_keys.ports.src = fl4->fl4_sport; 2079 hash_keys.ports.dst = fl4->fl4_dport; 2080 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2081 } 2082 mhash = flow_hash_from_keys(&hash_keys); 2083 break; 2084 case 2: 2085 memset(&hash_keys, 0, sizeof(hash_keys)); 2086 /* skb is currently provided only when forwarding */ 2087 if (skb) { 2088 struct flow_keys keys; 2089 2090 skb_flow_dissect_flow_keys(skb, &keys, 0); 2091 /* Inner can be v4 or v6 */ 2092 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2093 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2094 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2095 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2096 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2097 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2098 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2099 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2100 hash_keys.tags.flow_label = keys.tags.flow_label; 2101 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2102 } else { 2103 /* Same as case 0 */ 2104 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2105 ip_multipath_l3_keys(skb, &hash_keys); 2106 } 2107 } else { 2108 /* Same as case 0 */ 2109 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2110 hash_keys.addrs.v4addrs.src = fl4->saddr; 2111 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2112 } 2113 mhash = flow_hash_from_keys(&hash_keys); 2114 break; 2115 case 3: 2116 if (skb) 2117 mhash = fib_multipath_custom_hash_skb(net, skb); 2118 else 2119 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2120 break; 2121 } 2122 2123 if (multipath_hash) 2124 mhash = jhash_2words(mhash, multipath_hash, 0); 2125 2126 return mhash >> 1; 2127 } 2128 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2129 2130 static int ip_mkroute_input(struct sk_buff *skb, 2131 struct fib_result *res, 2132 struct in_device *in_dev, 2133 __be32 daddr, __be32 saddr, u32 tos, 2134 struct flow_keys *hkeys) 2135 { 2136 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2137 if (res->fi && fib_info_num_path(res->fi) > 1) { 2138 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2139 2140 fib_select_multipath(res, h); 2141 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2142 } 2143 #endif 2144 2145 /* create a routing cache entry */ 2146 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2147 } 2148 2149 /* Implements all the saddr-related checks as ip_route_input_slow(), 2150 * assuming daddr is valid and the destination is not a local broadcast one. 2151 * Uses the provided hint instead of performing a route lookup. 2152 */ 2153 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2154 u8 tos, struct net_device *dev, 2155 const struct sk_buff *hint) 2156 { 2157 struct in_device *in_dev = __in_dev_get_rcu(dev); 2158 struct rtable *rt = skb_rtable(hint); 2159 struct net *net = dev_net(dev); 2160 int err = -EINVAL; 2161 u32 tag = 0; 2162 2163 if (!in_dev) 2164 return -EINVAL; 2165 2166 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2167 goto martian_source; 2168 2169 if (ipv4_is_zeronet(saddr)) 2170 goto martian_source; 2171 2172 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2173 goto martian_source; 2174 2175 if (rt->rt_type != RTN_LOCAL) 2176 goto skip_validate_source; 2177 2178 tos &= IPTOS_RT_MASK; 2179 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2180 if (err < 0) 2181 goto martian_source; 2182 2183 skip_validate_source: 2184 skb_dst_copy(skb, hint); 2185 return 0; 2186 2187 martian_source: 2188 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2189 return err; 2190 } 2191 2192 /* get device for dst_alloc with local routes */ 2193 static struct net_device *ip_rt_get_dev(struct net *net, 2194 const struct fib_result *res) 2195 { 2196 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2197 struct net_device *dev = NULL; 2198 2199 if (nhc) 2200 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2201 2202 return dev ? : net->loopback_dev; 2203 } 2204 2205 /* 2206 * NOTE. We drop all the packets that has local source 2207 * addresses, because every properly looped back packet 2208 * must have correct destination already attached by output routine. 2209 * Changes in the enforced policies must be applied also to 2210 * ip_route_use_hint(). 2211 * 2212 * Such approach solves two big problems: 2213 * 1. Not simplex devices are handled properly. 2214 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2215 * called with rcu_read_lock() 2216 */ 2217 2218 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2219 u8 tos, struct net_device *dev, 2220 struct fib_result *res) 2221 { 2222 struct in_device *in_dev = __in_dev_get_rcu(dev); 2223 struct flow_keys *flkeys = NULL, _flkeys; 2224 struct net *net = dev_net(dev); 2225 struct ip_tunnel_info *tun_info; 2226 int err = -EINVAL; 2227 unsigned int flags = 0; 2228 u32 itag = 0; 2229 struct rtable *rth; 2230 struct flowi4 fl4; 2231 bool do_cache = true; 2232 2233 /* IP on this device is disabled. */ 2234 2235 if (!in_dev) 2236 goto out; 2237 2238 /* Check for the most weird martians, which can be not detected 2239 * by fib_lookup. 2240 */ 2241 2242 tun_info = skb_tunnel_info(skb); 2243 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2244 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2245 else 2246 fl4.flowi4_tun_key.tun_id = 0; 2247 skb_dst_drop(skb); 2248 2249 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2250 goto martian_source; 2251 2252 res->fi = NULL; 2253 res->table = NULL; 2254 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2255 goto brd_input; 2256 2257 /* Accept zero addresses only to limited broadcast; 2258 * I even do not know to fix it or not. Waiting for complains :-) 2259 */ 2260 if (ipv4_is_zeronet(saddr)) 2261 goto martian_source; 2262 2263 if (ipv4_is_zeronet(daddr)) 2264 goto martian_destination; 2265 2266 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2267 * and call it once if daddr or/and saddr are loopback addresses 2268 */ 2269 if (ipv4_is_loopback(daddr)) { 2270 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2271 goto martian_destination; 2272 } else if (ipv4_is_loopback(saddr)) { 2273 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2274 goto martian_source; 2275 } 2276 2277 /* 2278 * Now we are ready to route packet. 2279 */ 2280 fl4.flowi4_l3mdev = 0; 2281 fl4.flowi4_oif = 0; 2282 fl4.flowi4_iif = dev->ifindex; 2283 fl4.flowi4_mark = skb->mark; 2284 fl4.flowi4_tos = tos; 2285 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2286 fl4.flowi4_flags = 0; 2287 fl4.daddr = daddr; 2288 fl4.saddr = saddr; 2289 fl4.flowi4_uid = sock_net_uid(net, NULL); 2290 fl4.flowi4_multipath_hash = 0; 2291 2292 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2293 flkeys = &_flkeys; 2294 } else { 2295 fl4.flowi4_proto = 0; 2296 fl4.fl4_sport = 0; 2297 fl4.fl4_dport = 0; 2298 } 2299 2300 err = fib_lookup(net, &fl4, res, 0); 2301 if (err != 0) { 2302 if (!IN_DEV_FORWARD(in_dev)) 2303 err = -EHOSTUNREACH; 2304 goto no_route; 2305 } 2306 2307 if (res->type == RTN_BROADCAST) { 2308 if (IN_DEV_BFORWARD(in_dev)) 2309 goto make_route; 2310 /* not do cache if bc_forwarding is enabled */ 2311 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2312 do_cache = false; 2313 goto brd_input; 2314 } 2315 2316 if (res->type == RTN_LOCAL) { 2317 err = fib_validate_source(skb, saddr, daddr, tos, 2318 0, dev, in_dev, &itag); 2319 if (err < 0) 2320 goto martian_source; 2321 goto local_input; 2322 } 2323 2324 if (!IN_DEV_FORWARD(in_dev)) { 2325 err = -EHOSTUNREACH; 2326 goto no_route; 2327 } 2328 if (res->type != RTN_UNICAST) 2329 goto martian_destination; 2330 2331 make_route: 2332 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2333 out: return err; 2334 2335 brd_input: 2336 if (skb->protocol != htons(ETH_P_IP)) 2337 goto e_inval; 2338 2339 if (!ipv4_is_zeronet(saddr)) { 2340 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2341 in_dev, &itag); 2342 if (err < 0) 2343 goto martian_source; 2344 } 2345 flags |= RTCF_BROADCAST; 2346 res->type = RTN_BROADCAST; 2347 RT_CACHE_STAT_INC(in_brd); 2348 2349 local_input: 2350 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2351 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2352 2353 do_cache &= res->fi && !itag; 2354 if (do_cache) { 2355 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2356 2357 rth = rcu_dereference(nhc->nhc_rth_input); 2358 if (rt_cache_valid(rth)) { 2359 skb_dst_set_noref(skb, &rth->dst); 2360 err = 0; 2361 goto out; 2362 } 2363 } 2364 2365 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2366 flags | RTCF_LOCAL, res->type, false); 2367 if (!rth) 2368 goto e_nobufs; 2369 2370 rth->dst.output= ip_rt_bug; 2371 #ifdef CONFIG_IP_ROUTE_CLASSID 2372 rth->dst.tclassid = itag; 2373 #endif 2374 rth->rt_is_input = 1; 2375 2376 RT_CACHE_STAT_INC(in_slow_tot); 2377 if (res->type == RTN_UNREACHABLE) { 2378 rth->dst.input= ip_error; 2379 rth->dst.error= -err; 2380 rth->rt_flags &= ~RTCF_LOCAL; 2381 } 2382 2383 if (do_cache) { 2384 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2385 2386 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2387 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2388 WARN_ON(rth->dst.input == lwtunnel_input); 2389 rth->dst.lwtstate->orig_input = rth->dst.input; 2390 rth->dst.input = lwtunnel_input; 2391 } 2392 2393 if (unlikely(!rt_cache_route(nhc, rth))) 2394 rt_add_uncached_list(rth); 2395 } 2396 skb_dst_set(skb, &rth->dst); 2397 err = 0; 2398 goto out; 2399 2400 no_route: 2401 RT_CACHE_STAT_INC(in_no_route); 2402 res->type = RTN_UNREACHABLE; 2403 res->fi = NULL; 2404 res->table = NULL; 2405 goto local_input; 2406 2407 /* 2408 * Do not cache martian addresses: they should be logged (RFC1812) 2409 */ 2410 martian_destination: 2411 RT_CACHE_STAT_INC(in_martian_dst); 2412 #ifdef CONFIG_IP_ROUTE_VERBOSE 2413 if (IN_DEV_LOG_MARTIANS(in_dev)) 2414 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2415 &daddr, &saddr, dev->name); 2416 #endif 2417 2418 e_inval: 2419 err = -EINVAL; 2420 goto out; 2421 2422 e_nobufs: 2423 err = -ENOBUFS; 2424 goto out; 2425 2426 martian_source: 2427 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2428 goto out; 2429 } 2430 2431 /* called with rcu_read_lock held */ 2432 static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2433 u8 tos, struct net_device *dev, struct fib_result *res) 2434 { 2435 /* Multicast recognition logic is moved from route cache to here. 2436 * The problem was that too many Ethernet cards have broken/missing 2437 * hardware multicast filters :-( As result the host on multicasting 2438 * network acquires a lot of useless route cache entries, sort of 2439 * SDR messages from all the world. Now we try to get rid of them. 2440 * Really, provided software IP multicast filter is organized 2441 * reasonably (at least, hashed), it does not result in a slowdown 2442 * comparing with route cache reject entries. 2443 * Note, that multicast routers are not affected, because 2444 * route cache entry is created eventually. 2445 */ 2446 if (ipv4_is_multicast(daddr)) { 2447 struct in_device *in_dev = __in_dev_get_rcu(dev); 2448 int our = 0; 2449 int err = -EINVAL; 2450 2451 if (!in_dev) 2452 return err; 2453 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2454 ip_hdr(skb)->protocol); 2455 2456 /* check l3 master if no match yet */ 2457 if (!our && netif_is_l3_slave(dev)) { 2458 struct in_device *l3_in_dev; 2459 2460 l3_in_dev = __in_dev_get_rcu(skb->dev); 2461 if (l3_in_dev) 2462 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2463 ip_hdr(skb)->protocol); 2464 } 2465 2466 if (our 2467 #ifdef CONFIG_IP_MROUTE 2468 || 2469 (!ipv4_is_local_multicast(daddr) && 2470 IN_DEV_MFORWARD(in_dev)) 2471 #endif 2472 ) { 2473 err = ip_route_input_mc(skb, daddr, saddr, 2474 tos, dev, our); 2475 } 2476 return err; 2477 } 2478 2479 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2480 } 2481 2482 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2483 u8 tos, struct net_device *dev) 2484 { 2485 struct fib_result res; 2486 int err; 2487 2488 tos &= IPTOS_RT_MASK; 2489 rcu_read_lock(); 2490 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2491 rcu_read_unlock(); 2492 2493 return err; 2494 } 2495 EXPORT_SYMBOL(ip_route_input_noref); 2496 2497 /* called with rcu_read_lock() */ 2498 static struct rtable *__mkroute_output(const struct fib_result *res, 2499 const struct flowi4 *fl4, int orig_oif, 2500 struct net_device *dev_out, 2501 unsigned int flags) 2502 { 2503 struct fib_info *fi = res->fi; 2504 struct fib_nh_exception *fnhe; 2505 struct in_device *in_dev; 2506 u16 type = res->type; 2507 struct rtable *rth; 2508 bool do_cache; 2509 2510 in_dev = __in_dev_get_rcu(dev_out); 2511 if (!in_dev) 2512 return ERR_PTR(-EINVAL); 2513 2514 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2515 if (ipv4_is_loopback(fl4->saddr) && 2516 !(dev_out->flags & IFF_LOOPBACK) && 2517 !netif_is_l3_master(dev_out)) 2518 return ERR_PTR(-EINVAL); 2519 2520 if (ipv4_is_lbcast(fl4->daddr)) 2521 type = RTN_BROADCAST; 2522 else if (ipv4_is_multicast(fl4->daddr)) 2523 type = RTN_MULTICAST; 2524 else if (ipv4_is_zeronet(fl4->daddr)) 2525 return ERR_PTR(-EINVAL); 2526 2527 if (dev_out->flags & IFF_LOOPBACK) 2528 flags |= RTCF_LOCAL; 2529 2530 do_cache = true; 2531 if (type == RTN_BROADCAST) { 2532 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2533 fi = NULL; 2534 } else if (type == RTN_MULTICAST) { 2535 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2536 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2537 fl4->flowi4_proto)) 2538 flags &= ~RTCF_LOCAL; 2539 else 2540 do_cache = false; 2541 /* If multicast route do not exist use 2542 * default one, but do not gateway in this case. 2543 * Yes, it is hack. 2544 */ 2545 if (fi && res->prefixlen < 4) 2546 fi = NULL; 2547 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2548 (orig_oif != dev_out->ifindex)) { 2549 /* For local routes that require a particular output interface 2550 * we do not want to cache the result. Caching the result 2551 * causes incorrect behaviour when there are multiple source 2552 * addresses on the interface, the end result being that if the 2553 * intended recipient is waiting on that interface for the 2554 * packet he won't receive it because it will be delivered on 2555 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2556 * be set to the loopback interface as well. 2557 */ 2558 do_cache = false; 2559 } 2560 2561 fnhe = NULL; 2562 do_cache &= fi != NULL; 2563 if (fi) { 2564 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2565 struct rtable __rcu **prth; 2566 2567 fnhe = find_exception(nhc, fl4->daddr); 2568 if (!do_cache) 2569 goto add; 2570 if (fnhe) { 2571 prth = &fnhe->fnhe_rth_output; 2572 } else { 2573 if (unlikely(fl4->flowi4_flags & 2574 FLOWI_FLAG_KNOWN_NH && 2575 !(nhc->nhc_gw_family && 2576 nhc->nhc_scope == RT_SCOPE_LINK))) { 2577 do_cache = false; 2578 goto add; 2579 } 2580 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2581 } 2582 rth = rcu_dereference(*prth); 2583 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2584 return rth; 2585 } 2586 2587 add: 2588 rth = rt_dst_alloc(dev_out, flags, type, 2589 IN_DEV_ORCONF(in_dev, NOXFRM)); 2590 if (!rth) 2591 return ERR_PTR(-ENOBUFS); 2592 2593 rth->rt_iif = orig_oif; 2594 2595 RT_CACHE_STAT_INC(out_slow_tot); 2596 2597 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2598 if (flags & RTCF_LOCAL && 2599 !(dev_out->flags & IFF_LOOPBACK)) { 2600 rth->dst.output = ip_mc_output; 2601 RT_CACHE_STAT_INC(out_slow_mc); 2602 } 2603 #ifdef CONFIG_IP_MROUTE 2604 if (type == RTN_MULTICAST) { 2605 if (IN_DEV_MFORWARD(in_dev) && 2606 !ipv4_is_local_multicast(fl4->daddr)) { 2607 rth->dst.input = ip_mr_input; 2608 rth->dst.output = ip_mc_output; 2609 } 2610 } 2611 #endif 2612 } 2613 2614 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2615 lwtunnel_set_redirect(&rth->dst); 2616 2617 return rth; 2618 } 2619 2620 /* 2621 * Major route resolver routine. 2622 */ 2623 2624 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2625 const struct sk_buff *skb) 2626 { 2627 struct fib_result res = { 2628 .type = RTN_UNSPEC, 2629 .fi = NULL, 2630 .table = NULL, 2631 .tclassid = 0, 2632 }; 2633 struct rtable *rth; 2634 2635 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2636 ip_rt_fix_tos(fl4); 2637 2638 rcu_read_lock(); 2639 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2640 rcu_read_unlock(); 2641 2642 return rth; 2643 } 2644 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2645 2646 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2647 struct fib_result *res, 2648 const struct sk_buff *skb) 2649 { 2650 struct net_device *dev_out = NULL; 2651 int orig_oif = fl4->flowi4_oif; 2652 unsigned int flags = 0; 2653 struct rtable *rth; 2654 int err; 2655 2656 if (fl4->saddr) { 2657 if (ipv4_is_multicast(fl4->saddr) || 2658 ipv4_is_lbcast(fl4->saddr) || 2659 ipv4_is_zeronet(fl4->saddr)) { 2660 rth = ERR_PTR(-EINVAL); 2661 goto out; 2662 } 2663 2664 rth = ERR_PTR(-ENETUNREACH); 2665 2666 /* I removed check for oif == dev_out->oif here. 2667 * It was wrong for two reasons: 2668 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2669 * is assigned to multiple interfaces. 2670 * 2. Moreover, we are allowed to send packets with saddr 2671 * of another iface. --ANK 2672 */ 2673 2674 if (fl4->flowi4_oif == 0 && 2675 (ipv4_is_multicast(fl4->daddr) || 2676 ipv4_is_lbcast(fl4->daddr))) { 2677 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2678 dev_out = __ip_dev_find(net, fl4->saddr, false); 2679 if (!dev_out) 2680 goto out; 2681 2682 /* Special hack: user can direct multicasts 2683 * and limited broadcast via necessary interface 2684 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2685 * This hack is not just for fun, it allows 2686 * vic,vat and friends to work. 2687 * They bind socket to loopback, set ttl to zero 2688 * and expect that it will work. 2689 * From the viewpoint of routing cache they are broken, 2690 * because we are not allowed to build multicast path 2691 * with loopback source addr (look, routing cache 2692 * cannot know, that ttl is zero, so that packet 2693 * will not leave this host and route is valid). 2694 * Luckily, this hack is good workaround. 2695 */ 2696 2697 fl4->flowi4_oif = dev_out->ifindex; 2698 goto make_route; 2699 } 2700 2701 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2702 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2703 if (!__ip_dev_find(net, fl4->saddr, false)) 2704 goto out; 2705 } 2706 } 2707 2708 2709 if (fl4->flowi4_oif) { 2710 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2711 rth = ERR_PTR(-ENODEV); 2712 if (!dev_out) 2713 goto out; 2714 2715 /* RACE: Check return value of inet_select_addr instead. */ 2716 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2717 rth = ERR_PTR(-ENETUNREACH); 2718 goto out; 2719 } 2720 if (ipv4_is_local_multicast(fl4->daddr) || 2721 ipv4_is_lbcast(fl4->daddr) || 2722 fl4->flowi4_proto == IPPROTO_IGMP) { 2723 if (!fl4->saddr) 2724 fl4->saddr = inet_select_addr(dev_out, 0, 2725 RT_SCOPE_LINK); 2726 goto make_route; 2727 } 2728 if (!fl4->saddr) { 2729 if (ipv4_is_multicast(fl4->daddr)) 2730 fl4->saddr = inet_select_addr(dev_out, 0, 2731 fl4->flowi4_scope); 2732 else if (!fl4->daddr) 2733 fl4->saddr = inet_select_addr(dev_out, 0, 2734 RT_SCOPE_HOST); 2735 } 2736 } 2737 2738 if (!fl4->daddr) { 2739 fl4->daddr = fl4->saddr; 2740 if (!fl4->daddr) 2741 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2742 dev_out = net->loopback_dev; 2743 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2744 res->type = RTN_LOCAL; 2745 flags |= RTCF_LOCAL; 2746 goto make_route; 2747 } 2748 2749 err = fib_lookup(net, fl4, res, 0); 2750 if (err) { 2751 res->fi = NULL; 2752 res->table = NULL; 2753 if (fl4->flowi4_oif && 2754 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2755 /* Apparently, routing tables are wrong. Assume, 2756 * that the destination is on link. 2757 * 2758 * WHY? DW. 2759 * Because we are allowed to send to iface 2760 * even if it has NO routes and NO assigned 2761 * addresses. When oif is specified, routing 2762 * tables are looked up with only one purpose: 2763 * to catch if destination is gatewayed, rather than 2764 * direct. Moreover, if MSG_DONTROUTE is set, 2765 * we send packet, ignoring both routing tables 2766 * and ifaddr state. --ANK 2767 * 2768 * 2769 * We could make it even if oif is unknown, 2770 * likely IPv6, but we do not. 2771 */ 2772 2773 if (fl4->saddr == 0) 2774 fl4->saddr = inet_select_addr(dev_out, 0, 2775 RT_SCOPE_LINK); 2776 res->type = RTN_UNICAST; 2777 goto make_route; 2778 } 2779 rth = ERR_PTR(err); 2780 goto out; 2781 } 2782 2783 if (res->type == RTN_LOCAL) { 2784 if (!fl4->saddr) { 2785 if (res->fi->fib_prefsrc) 2786 fl4->saddr = res->fi->fib_prefsrc; 2787 else 2788 fl4->saddr = fl4->daddr; 2789 } 2790 2791 /* L3 master device is the loopback for that domain */ 2792 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2793 net->loopback_dev; 2794 2795 /* make sure orig_oif points to fib result device even 2796 * though packet rx/tx happens over loopback or l3mdev 2797 */ 2798 orig_oif = FIB_RES_OIF(*res); 2799 2800 fl4->flowi4_oif = dev_out->ifindex; 2801 flags |= RTCF_LOCAL; 2802 goto make_route; 2803 } 2804 2805 fib_select_path(net, res, fl4, skb); 2806 2807 dev_out = FIB_RES_DEV(*res); 2808 2809 make_route: 2810 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2811 2812 out: 2813 return rth; 2814 } 2815 2816 static struct dst_ops ipv4_dst_blackhole_ops = { 2817 .family = AF_INET, 2818 .default_advmss = ipv4_default_advmss, 2819 .neigh_lookup = ipv4_neigh_lookup, 2820 .check = dst_blackhole_check, 2821 .cow_metrics = dst_blackhole_cow_metrics, 2822 .update_pmtu = dst_blackhole_update_pmtu, 2823 .redirect = dst_blackhole_redirect, 2824 .mtu = dst_blackhole_mtu, 2825 }; 2826 2827 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2828 { 2829 struct rtable *ort = (struct rtable *) dst_orig; 2830 struct rtable *rt; 2831 2832 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2833 if (rt) { 2834 struct dst_entry *new = &rt->dst; 2835 2836 new->__use = 1; 2837 new->input = dst_discard; 2838 new->output = dst_discard_out; 2839 2840 new->dev = net->loopback_dev; 2841 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2842 2843 rt->rt_is_input = ort->rt_is_input; 2844 rt->rt_iif = ort->rt_iif; 2845 rt->rt_pmtu = ort->rt_pmtu; 2846 rt->rt_mtu_locked = ort->rt_mtu_locked; 2847 2848 rt->rt_genid = rt_genid_ipv4(net); 2849 rt->rt_flags = ort->rt_flags; 2850 rt->rt_type = ort->rt_type; 2851 rt->rt_uses_gateway = ort->rt_uses_gateway; 2852 rt->rt_gw_family = ort->rt_gw_family; 2853 if (rt->rt_gw_family == AF_INET) 2854 rt->rt_gw4 = ort->rt_gw4; 2855 else if (rt->rt_gw_family == AF_INET6) 2856 rt->rt_gw6 = ort->rt_gw6; 2857 } 2858 2859 dst_release(dst_orig); 2860 2861 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2862 } 2863 2864 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2865 const struct sock *sk) 2866 { 2867 struct rtable *rt = __ip_route_output_key(net, flp4); 2868 2869 if (IS_ERR(rt)) 2870 return rt; 2871 2872 if (flp4->flowi4_proto) { 2873 flp4->flowi4_oif = rt->dst.dev->ifindex; 2874 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2875 flowi4_to_flowi(flp4), 2876 sk, 0); 2877 } 2878 2879 return rt; 2880 } 2881 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2882 2883 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2884 struct net_device *dev, 2885 struct net *net, __be32 *saddr, 2886 const struct ip_tunnel_info *info, 2887 u8 protocol, bool use_cache) 2888 { 2889 #ifdef CONFIG_DST_CACHE 2890 struct dst_cache *dst_cache; 2891 #endif 2892 struct rtable *rt = NULL; 2893 struct flowi4 fl4; 2894 __u8 tos; 2895 2896 #ifdef CONFIG_DST_CACHE 2897 dst_cache = (struct dst_cache *)&info->dst_cache; 2898 if (use_cache) { 2899 rt = dst_cache_get_ip4(dst_cache, saddr); 2900 if (rt) 2901 return rt; 2902 } 2903 #endif 2904 memset(&fl4, 0, sizeof(fl4)); 2905 fl4.flowi4_mark = skb->mark; 2906 fl4.flowi4_proto = protocol; 2907 fl4.daddr = info->key.u.ipv4.dst; 2908 fl4.saddr = info->key.u.ipv4.src; 2909 tos = info->key.tos; 2910 fl4.flowi4_tos = RT_TOS(tos); 2911 2912 rt = ip_route_output_key(net, &fl4); 2913 if (IS_ERR(rt)) { 2914 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2915 return ERR_PTR(-ENETUNREACH); 2916 } 2917 if (rt->dst.dev == dev) { /* is this necessary? */ 2918 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2919 ip_rt_put(rt); 2920 return ERR_PTR(-ELOOP); 2921 } 2922 #ifdef CONFIG_DST_CACHE 2923 if (use_cache) 2924 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2925 #endif 2926 *saddr = fl4.saddr; 2927 return rt; 2928 } 2929 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2930 2931 /* called with rcu_read_lock held */ 2932 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2933 struct rtable *rt, u32 table_id, dscp_t dscp, 2934 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2935 u32 seq, unsigned int flags) 2936 { 2937 struct rtmsg *r; 2938 struct nlmsghdr *nlh; 2939 unsigned long expires = 0; 2940 u32 error; 2941 u32 metrics[RTAX_MAX]; 2942 2943 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2944 if (!nlh) 2945 return -EMSGSIZE; 2946 2947 r = nlmsg_data(nlh); 2948 r->rtm_family = AF_INET; 2949 r->rtm_dst_len = 32; 2950 r->rtm_src_len = 0; 2951 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2952 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2953 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2954 goto nla_put_failure; 2955 r->rtm_type = rt->rt_type; 2956 r->rtm_scope = RT_SCOPE_UNIVERSE; 2957 r->rtm_protocol = RTPROT_UNSPEC; 2958 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2959 if (rt->rt_flags & RTCF_NOTIFY) 2960 r->rtm_flags |= RTM_F_NOTIFY; 2961 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2962 r->rtm_flags |= RTCF_DOREDIRECT; 2963 2964 if (nla_put_in_addr(skb, RTA_DST, dst)) 2965 goto nla_put_failure; 2966 if (src) { 2967 r->rtm_src_len = 32; 2968 if (nla_put_in_addr(skb, RTA_SRC, src)) 2969 goto nla_put_failure; 2970 } 2971 if (rt->dst.dev && 2972 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2973 goto nla_put_failure; 2974 if (rt->dst.lwtstate && 2975 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2976 goto nla_put_failure; 2977 #ifdef CONFIG_IP_ROUTE_CLASSID 2978 if (rt->dst.tclassid && 2979 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2980 goto nla_put_failure; 2981 #endif 2982 if (fl4 && !rt_is_input_route(rt) && 2983 fl4->saddr != src) { 2984 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2985 goto nla_put_failure; 2986 } 2987 if (rt->rt_uses_gateway) { 2988 if (rt->rt_gw_family == AF_INET && 2989 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2990 goto nla_put_failure; 2991 } else if (rt->rt_gw_family == AF_INET6) { 2992 int alen = sizeof(struct in6_addr); 2993 struct nlattr *nla; 2994 struct rtvia *via; 2995 2996 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2997 if (!nla) 2998 goto nla_put_failure; 2999 3000 via = nla_data(nla); 3001 via->rtvia_family = AF_INET6; 3002 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3003 } 3004 } 3005 3006 expires = rt->dst.expires; 3007 if (expires) { 3008 unsigned long now = jiffies; 3009 3010 if (time_before(now, expires)) 3011 expires -= now; 3012 else 3013 expires = 0; 3014 } 3015 3016 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3017 if (rt->rt_pmtu && expires) 3018 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3019 if (rt->rt_mtu_locked && expires) 3020 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3021 if (rtnetlink_put_metrics(skb, metrics) < 0) 3022 goto nla_put_failure; 3023 3024 if (fl4) { 3025 if (fl4->flowi4_mark && 3026 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3027 goto nla_put_failure; 3028 3029 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3030 nla_put_u32(skb, RTA_UID, 3031 from_kuid_munged(current_user_ns(), 3032 fl4->flowi4_uid))) 3033 goto nla_put_failure; 3034 3035 if (rt_is_input_route(rt)) { 3036 #ifdef CONFIG_IP_MROUTE 3037 if (ipv4_is_multicast(dst) && 3038 !ipv4_is_local_multicast(dst) && 3039 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3040 int err = ipmr_get_route(net, skb, 3041 fl4->saddr, fl4->daddr, 3042 r, portid); 3043 3044 if (err <= 0) { 3045 if (err == 0) 3046 return 0; 3047 goto nla_put_failure; 3048 } 3049 } else 3050 #endif 3051 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3052 goto nla_put_failure; 3053 } 3054 } 3055 3056 error = rt->dst.error; 3057 3058 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3059 goto nla_put_failure; 3060 3061 nlmsg_end(skb, nlh); 3062 return 0; 3063 3064 nla_put_failure: 3065 nlmsg_cancel(skb, nlh); 3066 return -EMSGSIZE; 3067 } 3068 3069 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3070 struct netlink_callback *cb, u32 table_id, 3071 struct fnhe_hash_bucket *bucket, int genid, 3072 int *fa_index, int fa_start, unsigned int flags) 3073 { 3074 int i; 3075 3076 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3077 struct fib_nh_exception *fnhe; 3078 3079 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3080 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3081 struct rtable *rt; 3082 int err; 3083 3084 if (*fa_index < fa_start) 3085 goto next; 3086 3087 if (fnhe->fnhe_genid != genid) 3088 goto next; 3089 3090 if (fnhe->fnhe_expires && 3091 time_after(jiffies, fnhe->fnhe_expires)) 3092 goto next; 3093 3094 rt = rcu_dereference(fnhe->fnhe_rth_input); 3095 if (!rt) 3096 rt = rcu_dereference(fnhe->fnhe_rth_output); 3097 if (!rt) 3098 goto next; 3099 3100 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3101 table_id, 0, NULL, skb, 3102 NETLINK_CB(cb->skb).portid, 3103 cb->nlh->nlmsg_seq, flags); 3104 if (err) 3105 return err; 3106 next: 3107 (*fa_index)++; 3108 } 3109 } 3110 3111 return 0; 3112 } 3113 3114 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3115 u32 table_id, struct fib_info *fi, 3116 int *fa_index, int fa_start, unsigned int flags) 3117 { 3118 struct net *net = sock_net(cb->skb->sk); 3119 int nhsel, genid = fnhe_genid(net); 3120 3121 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3122 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3123 struct fnhe_hash_bucket *bucket; 3124 int err; 3125 3126 if (nhc->nhc_flags & RTNH_F_DEAD) 3127 continue; 3128 3129 rcu_read_lock(); 3130 bucket = rcu_dereference(nhc->nhc_exceptions); 3131 err = 0; 3132 if (bucket) 3133 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3134 genid, fa_index, fa_start, 3135 flags); 3136 rcu_read_unlock(); 3137 if (err) 3138 return err; 3139 } 3140 3141 return 0; 3142 } 3143 3144 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3145 u8 ip_proto, __be16 sport, 3146 __be16 dport) 3147 { 3148 struct sk_buff *skb; 3149 struct iphdr *iph; 3150 3151 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3152 if (!skb) 3153 return NULL; 3154 3155 /* Reserve room for dummy headers, this skb can pass 3156 * through good chunk of routing engine. 3157 */ 3158 skb_reset_mac_header(skb); 3159 skb_reset_network_header(skb); 3160 skb->protocol = htons(ETH_P_IP); 3161 iph = skb_put(skb, sizeof(struct iphdr)); 3162 iph->protocol = ip_proto; 3163 iph->saddr = src; 3164 iph->daddr = dst; 3165 iph->version = 0x4; 3166 iph->frag_off = 0; 3167 iph->ihl = 0x5; 3168 skb_set_transport_header(skb, skb->len); 3169 3170 switch (iph->protocol) { 3171 case IPPROTO_UDP: { 3172 struct udphdr *udph; 3173 3174 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3175 udph->source = sport; 3176 udph->dest = dport; 3177 udph->len = htons(sizeof(struct udphdr)); 3178 udph->check = 0; 3179 break; 3180 } 3181 case IPPROTO_TCP: { 3182 struct tcphdr *tcph; 3183 3184 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3185 tcph->source = sport; 3186 tcph->dest = dport; 3187 tcph->doff = sizeof(struct tcphdr) / 4; 3188 tcph->rst = 1; 3189 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3190 src, dst, 0); 3191 break; 3192 } 3193 case IPPROTO_ICMP: { 3194 struct icmphdr *icmph; 3195 3196 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3197 icmph->type = ICMP_ECHO; 3198 icmph->code = 0; 3199 } 3200 } 3201 3202 return skb; 3203 } 3204 3205 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3206 const struct nlmsghdr *nlh, 3207 struct nlattr **tb, 3208 struct netlink_ext_ack *extack) 3209 { 3210 struct rtmsg *rtm; 3211 int i, err; 3212 3213 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3214 NL_SET_ERR_MSG(extack, 3215 "ipv4: Invalid header for route get request"); 3216 return -EINVAL; 3217 } 3218 3219 if (!netlink_strict_get_check(skb)) 3220 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3221 rtm_ipv4_policy, extack); 3222 3223 rtm = nlmsg_data(nlh); 3224 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3225 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3226 rtm->rtm_table || rtm->rtm_protocol || 3227 rtm->rtm_scope || rtm->rtm_type) { 3228 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3229 return -EINVAL; 3230 } 3231 3232 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3233 RTM_F_LOOKUP_TABLE | 3234 RTM_F_FIB_MATCH)) { 3235 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3236 return -EINVAL; 3237 } 3238 3239 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3240 rtm_ipv4_policy, extack); 3241 if (err) 3242 return err; 3243 3244 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3245 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3246 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3247 return -EINVAL; 3248 } 3249 3250 for (i = 0; i <= RTA_MAX; i++) { 3251 if (!tb[i]) 3252 continue; 3253 3254 switch (i) { 3255 case RTA_IIF: 3256 case RTA_OIF: 3257 case RTA_SRC: 3258 case RTA_DST: 3259 case RTA_IP_PROTO: 3260 case RTA_SPORT: 3261 case RTA_DPORT: 3262 case RTA_MARK: 3263 case RTA_UID: 3264 break; 3265 default: 3266 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3267 return -EINVAL; 3268 } 3269 } 3270 3271 return 0; 3272 } 3273 3274 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3275 struct netlink_ext_ack *extack) 3276 { 3277 struct net *net = sock_net(in_skb->sk); 3278 struct nlattr *tb[RTA_MAX+1]; 3279 u32 table_id = RT_TABLE_MAIN; 3280 __be16 sport = 0, dport = 0; 3281 struct fib_result res = {}; 3282 u8 ip_proto = IPPROTO_UDP; 3283 struct rtable *rt = NULL; 3284 struct sk_buff *skb; 3285 struct rtmsg *rtm; 3286 struct flowi4 fl4 = {}; 3287 __be32 dst = 0; 3288 __be32 src = 0; 3289 kuid_t uid; 3290 u32 iif; 3291 int err; 3292 int mark; 3293 3294 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3295 if (err < 0) 3296 return err; 3297 3298 rtm = nlmsg_data(nlh); 3299 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3300 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3301 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3302 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3303 if (tb[RTA_UID]) 3304 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3305 else 3306 uid = (iif ? INVALID_UID : current_uid()); 3307 3308 if (tb[RTA_IP_PROTO]) { 3309 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3310 &ip_proto, AF_INET, extack); 3311 if (err) 3312 return err; 3313 } 3314 3315 if (tb[RTA_SPORT]) 3316 sport = nla_get_be16(tb[RTA_SPORT]); 3317 3318 if (tb[RTA_DPORT]) 3319 dport = nla_get_be16(tb[RTA_DPORT]); 3320 3321 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3322 if (!skb) 3323 return -ENOBUFS; 3324 3325 fl4.daddr = dst; 3326 fl4.saddr = src; 3327 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3328 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3329 fl4.flowi4_mark = mark; 3330 fl4.flowi4_uid = uid; 3331 if (sport) 3332 fl4.fl4_sport = sport; 3333 if (dport) 3334 fl4.fl4_dport = dport; 3335 fl4.flowi4_proto = ip_proto; 3336 3337 rcu_read_lock(); 3338 3339 if (iif) { 3340 struct net_device *dev; 3341 3342 dev = dev_get_by_index_rcu(net, iif); 3343 if (!dev) { 3344 err = -ENODEV; 3345 goto errout_rcu; 3346 } 3347 3348 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3349 skb->dev = dev; 3350 skb->mark = mark; 3351 err = ip_route_input_rcu(skb, dst, src, 3352 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3353 &res); 3354 3355 rt = skb_rtable(skb); 3356 if (err == 0 && rt->dst.error) 3357 err = -rt->dst.error; 3358 } else { 3359 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3360 skb->dev = net->loopback_dev; 3361 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3362 err = 0; 3363 if (IS_ERR(rt)) 3364 err = PTR_ERR(rt); 3365 else 3366 skb_dst_set(skb, &rt->dst); 3367 } 3368 3369 if (err) 3370 goto errout_rcu; 3371 3372 if (rtm->rtm_flags & RTM_F_NOTIFY) 3373 rt->rt_flags |= RTCF_NOTIFY; 3374 3375 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3376 table_id = res.table ? res.table->tb_id : 0; 3377 3378 /* reset skb for netlink reply msg */ 3379 skb_trim(skb, 0); 3380 skb_reset_network_header(skb); 3381 skb_reset_transport_header(skb); 3382 skb_reset_mac_header(skb); 3383 3384 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3385 struct fib_rt_info fri; 3386 3387 if (!res.fi) { 3388 err = fib_props[res.type].error; 3389 if (!err) 3390 err = -EHOSTUNREACH; 3391 goto errout_rcu; 3392 } 3393 fri.fi = res.fi; 3394 fri.tb_id = table_id; 3395 fri.dst = res.prefix; 3396 fri.dst_len = res.prefixlen; 3397 fri.dscp = res.dscp; 3398 fri.type = rt->rt_type; 3399 fri.offload = 0; 3400 fri.trap = 0; 3401 fri.offload_failed = 0; 3402 if (res.fa_head) { 3403 struct fib_alias *fa; 3404 3405 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3406 u8 slen = 32 - fri.dst_len; 3407 3408 if (fa->fa_slen == slen && 3409 fa->tb_id == fri.tb_id && 3410 fa->fa_dscp == fri.dscp && 3411 fa->fa_info == res.fi && 3412 fa->fa_type == fri.type) { 3413 fri.offload = READ_ONCE(fa->offload); 3414 fri.trap = READ_ONCE(fa->trap); 3415 fri.offload_failed = 3416 READ_ONCE(fa->offload_failed); 3417 break; 3418 } 3419 } 3420 } 3421 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3422 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3423 } else { 3424 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3425 skb, NETLINK_CB(in_skb).portid, 3426 nlh->nlmsg_seq, 0); 3427 } 3428 if (err < 0) 3429 goto errout_rcu; 3430 3431 rcu_read_unlock(); 3432 3433 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3434 3435 errout_free: 3436 return err; 3437 errout_rcu: 3438 rcu_read_unlock(); 3439 kfree_skb(skb); 3440 goto errout_free; 3441 } 3442 3443 void ip_rt_multicast_event(struct in_device *in_dev) 3444 { 3445 rt_cache_flush(dev_net(in_dev->dev)); 3446 } 3447 3448 #ifdef CONFIG_SYSCTL 3449 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3450 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3451 static int ip_rt_gc_elasticity __read_mostly = 8; 3452 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3453 3454 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3455 void *buffer, size_t *lenp, loff_t *ppos) 3456 { 3457 struct net *net = (struct net *)__ctl->extra1; 3458 3459 if (write) { 3460 rt_cache_flush(net); 3461 fnhe_genid_bump(net); 3462 return 0; 3463 } 3464 3465 return -EINVAL; 3466 } 3467 3468 static struct ctl_table ipv4_route_table[] = { 3469 { 3470 .procname = "gc_thresh", 3471 .data = &ipv4_dst_ops.gc_thresh, 3472 .maxlen = sizeof(int), 3473 .mode = 0644, 3474 .proc_handler = proc_dointvec, 3475 }, 3476 { 3477 .procname = "max_size", 3478 .data = &ip_rt_max_size, 3479 .maxlen = sizeof(int), 3480 .mode = 0644, 3481 .proc_handler = proc_dointvec, 3482 }, 3483 { 3484 /* Deprecated. Use gc_min_interval_ms */ 3485 3486 .procname = "gc_min_interval", 3487 .data = &ip_rt_gc_min_interval, 3488 .maxlen = sizeof(int), 3489 .mode = 0644, 3490 .proc_handler = proc_dointvec_jiffies, 3491 }, 3492 { 3493 .procname = "gc_min_interval_ms", 3494 .data = &ip_rt_gc_min_interval, 3495 .maxlen = sizeof(int), 3496 .mode = 0644, 3497 .proc_handler = proc_dointvec_ms_jiffies, 3498 }, 3499 { 3500 .procname = "gc_timeout", 3501 .data = &ip_rt_gc_timeout, 3502 .maxlen = sizeof(int), 3503 .mode = 0644, 3504 .proc_handler = proc_dointvec_jiffies, 3505 }, 3506 { 3507 .procname = "gc_interval", 3508 .data = &ip_rt_gc_interval, 3509 .maxlen = sizeof(int), 3510 .mode = 0644, 3511 .proc_handler = proc_dointvec_jiffies, 3512 }, 3513 { 3514 .procname = "redirect_load", 3515 .data = &ip_rt_redirect_load, 3516 .maxlen = sizeof(int), 3517 .mode = 0644, 3518 .proc_handler = proc_dointvec, 3519 }, 3520 { 3521 .procname = "redirect_number", 3522 .data = &ip_rt_redirect_number, 3523 .maxlen = sizeof(int), 3524 .mode = 0644, 3525 .proc_handler = proc_dointvec, 3526 }, 3527 { 3528 .procname = "redirect_silence", 3529 .data = &ip_rt_redirect_silence, 3530 .maxlen = sizeof(int), 3531 .mode = 0644, 3532 .proc_handler = proc_dointvec, 3533 }, 3534 { 3535 .procname = "error_cost", 3536 .data = &ip_rt_error_cost, 3537 .maxlen = sizeof(int), 3538 .mode = 0644, 3539 .proc_handler = proc_dointvec, 3540 }, 3541 { 3542 .procname = "error_burst", 3543 .data = &ip_rt_error_burst, 3544 .maxlen = sizeof(int), 3545 .mode = 0644, 3546 .proc_handler = proc_dointvec, 3547 }, 3548 { 3549 .procname = "gc_elasticity", 3550 .data = &ip_rt_gc_elasticity, 3551 .maxlen = sizeof(int), 3552 .mode = 0644, 3553 .proc_handler = proc_dointvec, 3554 }, 3555 { } 3556 }; 3557 3558 static const char ipv4_route_flush_procname[] = "flush"; 3559 3560 static struct ctl_table ipv4_route_netns_table[] = { 3561 { 3562 .procname = ipv4_route_flush_procname, 3563 .maxlen = sizeof(int), 3564 .mode = 0200, 3565 .proc_handler = ipv4_sysctl_rtcache_flush, 3566 }, 3567 { 3568 .procname = "min_pmtu", 3569 .data = &init_net.ipv4.ip_rt_min_pmtu, 3570 .maxlen = sizeof(int), 3571 .mode = 0644, 3572 .proc_handler = proc_dointvec_minmax, 3573 .extra1 = &ip_min_valid_pmtu, 3574 }, 3575 { 3576 .procname = "mtu_expires", 3577 .data = &init_net.ipv4.ip_rt_mtu_expires, 3578 .maxlen = sizeof(int), 3579 .mode = 0644, 3580 .proc_handler = proc_dointvec_jiffies, 3581 }, 3582 { 3583 .procname = "min_adv_mss", 3584 .data = &init_net.ipv4.ip_rt_min_advmss, 3585 .maxlen = sizeof(int), 3586 .mode = 0644, 3587 .proc_handler = proc_dointvec, 3588 }, 3589 { }, 3590 }; 3591 3592 static __net_init int sysctl_route_net_init(struct net *net) 3593 { 3594 struct ctl_table *tbl; 3595 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3596 3597 tbl = ipv4_route_netns_table; 3598 if (!net_eq(net, &init_net)) { 3599 int i; 3600 3601 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3602 if (!tbl) 3603 goto err_dup; 3604 3605 /* Don't export non-whitelisted sysctls to unprivileged users */ 3606 if (net->user_ns != &init_user_ns) { 3607 if (tbl[0].procname != ipv4_route_flush_procname) { 3608 tbl[0].procname = NULL; 3609 table_size = 0; 3610 } 3611 } 3612 3613 /* Update the variables to point into the current struct net 3614 * except for the first element flush 3615 */ 3616 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3617 tbl[i].data += (void *)net - (void *)&init_net; 3618 } 3619 tbl[0].extra1 = net; 3620 3621 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3622 tbl, table_size); 3623 if (!net->ipv4.route_hdr) 3624 goto err_reg; 3625 return 0; 3626 3627 err_reg: 3628 if (tbl != ipv4_route_netns_table) 3629 kfree(tbl); 3630 err_dup: 3631 return -ENOMEM; 3632 } 3633 3634 static __net_exit void sysctl_route_net_exit(struct net *net) 3635 { 3636 struct ctl_table *tbl; 3637 3638 tbl = net->ipv4.route_hdr->ctl_table_arg; 3639 unregister_net_sysctl_table(net->ipv4.route_hdr); 3640 BUG_ON(tbl == ipv4_route_netns_table); 3641 kfree(tbl); 3642 } 3643 3644 static __net_initdata struct pernet_operations sysctl_route_ops = { 3645 .init = sysctl_route_net_init, 3646 .exit = sysctl_route_net_exit, 3647 }; 3648 #endif 3649 3650 static __net_init int netns_ip_rt_init(struct net *net) 3651 { 3652 /* Set default value for namespaceified sysctls */ 3653 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3654 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3655 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3656 return 0; 3657 } 3658 3659 static struct pernet_operations __net_initdata ip_rt_ops = { 3660 .init = netns_ip_rt_init, 3661 }; 3662 3663 static __net_init int rt_genid_init(struct net *net) 3664 { 3665 atomic_set(&net->ipv4.rt_genid, 0); 3666 atomic_set(&net->fnhe_genid, 0); 3667 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3668 return 0; 3669 } 3670 3671 static __net_initdata struct pernet_operations rt_genid_ops = { 3672 .init = rt_genid_init, 3673 }; 3674 3675 static int __net_init ipv4_inetpeer_init(struct net *net) 3676 { 3677 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3678 3679 if (!bp) 3680 return -ENOMEM; 3681 inet_peer_base_init(bp); 3682 net->ipv4.peers = bp; 3683 return 0; 3684 } 3685 3686 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3687 { 3688 struct inet_peer_base *bp = net->ipv4.peers; 3689 3690 net->ipv4.peers = NULL; 3691 inetpeer_invalidate_tree(bp); 3692 kfree(bp); 3693 } 3694 3695 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3696 .init = ipv4_inetpeer_init, 3697 .exit = ipv4_inetpeer_exit, 3698 }; 3699 3700 #ifdef CONFIG_IP_ROUTE_CLASSID 3701 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3702 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3703 3704 int __init ip_rt_init(void) 3705 { 3706 void *idents_hash; 3707 int cpu; 3708 3709 /* For modern hosts, this will use 2 MB of memory */ 3710 idents_hash = alloc_large_system_hash("IP idents", 3711 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3712 0, 3713 16, /* one bucket per 64 KB */ 3714 HASH_ZERO, 3715 NULL, 3716 &ip_idents_mask, 3717 2048, 3718 256*1024); 3719 3720 ip_idents = idents_hash; 3721 3722 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3723 3724 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3725 3726 for_each_possible_cpu(cpu) { 3727 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3728 3729 INIT_LIST_HEAD(&ul->head); 3730 INIT_LIST_HEAD(&ul->quarantine); 3731 spin_lock_init(&ul->lock); 3732 } 3733 #ifdef CONFIG_IP_ROUTE_CLASSID 3734 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3735 if (!ip_rt_acct) 3736 panic("IP: failed to allocate ip_rt_acct\n"); 3737 #endif 3738 3739 ipv4_dst_ops.kmem_cachep = 3740 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3741 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3742 3743 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3744 3745 if (dst_entries_init(&ipv4_dst_ops) < 0) 3746 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3747 3748 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3749 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3750 3751 ipv4_dst_ops.gc_thresh = ~0; 3752 ip_rt_max_size = INT_MAX; 3753 3754 devinet_init(); 3755 ip_fib_init(); 3756 3757 if (ip_rt_proc_init()) 3758 pr_err("Unable to create route proc files\n"); 3759 #ifdef CONFIG_XFRM 3760 xfrm_init(); 3761 xfrm4_init(); 3762 #endif 3763 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3764 RTNL_FLAG_DOIT_UNLOCKED); 3765 3766 #ifdef CONFIG_SYSCTL 3767 register_pernet_subsys(&sysctl_route_ops); 3768 #endif 3769 register_pernet_subsys(&ip_rt_ops); 3770 register_pernet_subsys(&rt_genid_ops); 3771 register_pernet_subsys(&ipv4_inetpeer_ops); 3772 return 0; 3773 } 3774 3775 #ifdef CONFIG_SYSCTL 3776 /* 3777 * We really need to sanitize the damn ipv4 init order, then all 3778 * this nonsense will go away. 3779 */ 3780 void __init ip_static_sysctl_init(void) 3781 { 3782 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3783 } 3784 #endif 3785