1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_FL_TOS(oldflp4) \ 110 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 111 112 #define RT_GC_TIMEOUT (300*HZ) 113 114 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 115 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 116 #define DEFAULT_MIN_ADVMSS 256 117 static int ip_rt_max_size; 118 static int ip_rt_redirect_number __read_mostly = 9; 119 static int ip_rt_redirect_load __read_mostly = HZ / 50; 120 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 121 static int ip_rt_error_cost __read_mostly = HZ; 122 static int ip_rt_error_burst __read_mostly = 5 * HZ; 123 124 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 125 126 /* 127 * Interface to generic destination cache. 128 */ 129 130 INDIRECT_CALLABLE_SCOPE 131 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 132 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 133 INDIRECT_CALLABLE_SCOPE 134 unsigned int ipv4_mtu(const struct dst_entry *dst); 135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 136 static void ipv4_link_failure(struct sk_buff *skb); 137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 138 struct sk_buff *skb, u32 mtu, 139 bool confirm_neigh); 140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 141 struct sk_buff *skb); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 144 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 145 { 146 WARN_ON(1); 147 return NULL; 148 } 149 150 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 151 struct sk_buff *skb, 152 const void *daddr); 153 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 154 155 static struct dst_ops ipv4_dst_ops = { 156 .family = AF_INET, 157 .check = ipv4_dst_check, 158 .default_advmss = ipv4_default_advmss, 159 .mtu = ipv4_mtu, 160 .cow_metrics = ipv4_cow_metrics, 161 .destroy = ipv4_dst_destroy, 162 .negative_advice = ipv4_negative_advice, 163 .link_failure = ipv4_link_failure, 164 .update_pmtu = ip_rt_update_pmtu, 165 .redirect = ip_do_redirect, 166 .local_out = __ip_local_out, 167 .neigh_lookup = ipv4_neigh_lookup, 168 .confirm_neigh = ipv4_confirm_neigh, 169 }; 170 171 #define ECN_OR_COST(class) TC_PRIO_##class 172 173 const __u8 ip_tos2prio[16] = { 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BESTEFFORT, 177 ECN_OR_COST(BESTEFFORT), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_BULK, 181 ECN_OR_COST(BULK), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE, 185 ECN_OR_COST(INTERACTIVE), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK), 188 TC_PRIO_INTERACTIVE_BULK, 189 ECN_OR_COST(INTERACTIVE_BULK) 190 }; 191 EXPORT_SYMBOL(ip_tos2prio); 192 193 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 196 #ifdef CONFIG_PROC_FS 197 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 198 { 199 if (*pos) 200 return NULL; 201 return SEQ_START_TOKEN; 202 } 203 204 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 205 { 206 ++*pos; 207 return NULL; 208 } 209 210 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 211 { 212 } 213 214 static int rt_cache_seq_show(struct seq_file *seq, void *v) 215 { 216 if (v == SEQ_START_TOKEN) 217 seq_printf(seq, "%-127s\n", 218 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 219 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 220 "HHUptod\tSpecDst"); 221 return 0; 222 } 223 224 static const struct seq_operations rt_cache_seq_ops = { 225 .start = rt_cache_seq_start, 226 .next = rt_cache_seq_next, 227 .stop = rt_cache_seq_stop, 228 .show = rt_cache_seq_show, 229 }; 230 231 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 232 { 233 int cpu; 234 235 if (*pos == 0) 236 return SEQ_START_TOKEN; 237 238 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 239 if (!cpu_possible(cpu)) 240 continue; 241 *pos = cpu+1; 242 return &per_cpu(rt_cache_stat, cpu); 243 } 244 return NULL; 245 } 246 247 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 248 { 249 int cpu; 250 251 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 252 if (!cpu_possible(cpu)) 253 continue; 254 *pos = cpu+1; 255 return &per_cpu(rt_cache_stat, cpu); 256 } 257 (*pos)++; 258 return NULL; 259 260 } 261 262 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 263 { 264 265 } 266 267 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 268 { 269 struct rt_cache_stat *st = v; 270 271 if (v == SEQ_START_TOKEN) { 272 seq_puts(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 273 return 0; 274 } 275 276 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 277 "%08x %08x %08x %08x %08x %08x " 278 "%08x %08x %08x %08x\n", 279 dst_entries_get_slow(&ipv4_dst_ops), 280 0, /* st->in_hit */ 281 st->in_slow_tot, 282 st->in_slow_mc, 283 st->in_no_route, 284 st->in_brd, 285 st->in_martian_dst, 286 st->in_martian_src, 287 288 0, /* st->out_hit */ 289 st->out_slow_tot, 290 st->out_slow_mc, 291 292 0, /* st->gc_total */ 293 0, /* st->gc_ignored */ 294 0, /* st->gc_goal_miss */ 295 0, /* st->gc_dst_overflow */ 296 0, /* st->in_hlist_search */ 297 0 /* st->out_hlist_search */ 298 ); 299 return 0; 300 } 301 302 static const struct seq_operations rt_cpu_seq_ops = { 303 .start = rt_cpu_seq_start, 304 .next = rt_cpu_seq_next, 305 .stop = rt_cpu_seq_stop, 306 .show = rt_cpu_seq_show, 307 }; 308 309 #ifdef CONFIG_IP_ROUTE_CLASSID 310 static int rt_acct_proc_show(struct seq_file *m, void *v) 311 { 312 struct ip_rt_acct *dst, *src; 313 unsigned int i, j; 314 315 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 316 if (!dst) 317 return -ENOMEM; 318 319 for_each_possible_cpu(i) { 320 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 321 for (j = 0; j < 256; j++) { 322 dst[j].o_bytes += src[j].o_bytes; 323 dst[j].o_packets += src[j].o_packets; 324 dst[j].i_bytes += src[j].i_bytes; 325 dst[j].i_packets += src[j].i_packets; 326 } 327 } 328 329 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 330 kfree(dst); 331 return 0; 332 } 333 #endif 334 335 static int __net_init ip_rt_do_proc_init(struct net *net) 336 { 337 struct proc_dir_entry *pde; 338 339 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 340 &rt_cache_seq_ops); 341 if (!pde) 342 goto err1; 343 344 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 345 &rt_cpu_seq_ops); 346 if (!pde) 347 goto err2; 348 349 #ifdef CONFIG_IP_ROUTE_CLASSID 350 pde = proc_create_single("rt_acct", 0, net->proc_net, 351 rt_acct_proc_show); 352 if (!pde) 353 goto err3; 354 #endif 355 return 0; 356 357 #ifdef CONFIG_IP_ROUTE_CLASSID 358 err3: 359 remove_proc_entry("rt_cache", net->proc_net_stat); 360 #endif 361 err2: 362 remove_proc_entry("rt_cache", net->proc_net); 363 err1: 364 return -ENOMEM; 365 } 366 367 static void __net_exit ip_rt_do_proc_exit(struct net *net) 368 { 369 remove_proc_entry("rt_cache", net->proc_net_stat); 370 remove_proc_entry("rt_cache", net->proc_net); 371 #ifdef CONFIG_IP_ROUTE_CLASSID 372 remove_proc_entry("rt_acct", net->proc_net); 373 #endif 374 } 375 376 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 377 .init = ip_rt_do_proc_init, 378 .exit = ip_rt_do_proc_exit, 379 }; 380 381 static int __init ip_rt_proc_init(void) 382 { 383 return register_pernet_subsys(&ip_rt_proc_ops); 384 } 385 386 #else 387 static inline int ip_rt_proc_init(void) 388 { 389 return 0; 390 } 391 #endif /* CONFIG_PROC_FS */ 392 393 static inline bool rt_is_expired(const struct rtable *rth) 394 { 395 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 396 } 397 398 void rt_cache_flush(struct net *net) 399 { 400 rt_genid_bump_ipv4(net); 401 } 402 403 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 404 struct sk_buff *skb, 405 const void *daddr) 406 { 407 const struct rtable *rt = container_of(dst, struct rtable, dst); 408 struct net_device *dev = dst->dev; 409 struct neighbour *n; 410 411 rcu_read_lock_bh(); 412 413 if (likely(rt->rt_gw_family == AF_INET)) { 414 n = ip_neigh_gw4(dev, rt->rt_gw4); 415 } else if (rt->rt_gw_family == AF_INET6) { 416 n = ip_neigh_gw6(dev, &rt->rt_gw6); 417 } else { 418 __be32 pkey; 419 420 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 421 n = ip_neigh_gw4(dev, pkey); 422 } 423 424 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 425 n = NULL; 426 427 rcu_read_unlock_bh(); 428 429 return n; 430 } 431 432 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 433 { 434 const struct rtable *rt = container_of(dst, struct rtable, dst); 435 struct net_device *dev = dst->dev; 436 const __be32 *pkey = daddr; 437 438 if (rt->rt_gw_family == AF_INET) { 439 pkey = (const __be32 *)&rt->rt_gw4; 440 } else if (rt->rt_gw_family == AF_INET6) { 441 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 442 } else if (!daddr || 443 (rt->rt_flags & 444 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 445 return; 446 } 447 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 448 } 449 450 /* Hash tables of size 2048..262144 depending on RAM size. 451 * Each bucket uses 8 bytes. 452 */ 453 static u32 ip_idents_mask __read_mostly; 454 static atomic_t *ip_idents __read_mostly; 455 static u32 *ip_tstamps __read_mostly; 456 457 /* In order to protect privacy, we add a perturbation to identifiers 458 * if one generator is seldom used. This makes hard for an attacker 459 * to infer how many packets were sent between two points in time. 460 */ 461 static u32 ip_idents_reserve(u32 hash, int segs) 462 { 463 u32 bucket, old, now = (u32)jiffies; 464 atomic_t *p_id; 465 u32 *p_tstamp; 466 u32 delta = 0; 467 468 bucket = hash & ip_idents_mask; 469 p_tstamp = ip_tstamps + bucket; 470 p_id = ip_idents + bucket; 471 old = READ_ONCE(*p_tstamp); 472 473 if (old != now && cmpxchg(p_tstamp, old, now) == old) 474 delta = prandom_u32_max(now - old); 475 476 /* If UBSAN reports an error there, please make sure your compiler 477 * supports -fno-strict-overflow before reporting it that was a bug 478 * in UBSAN, and it has been fixed in GCC-8. 479 */ 480 return atomic_add_return(segs + delta, p_id) - segs; 481 } 482 483 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 484 { 485 u32 hash, id; 486 487 /* Note the following code is not safe, but this is okay. */ 488 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 489 get_random_bytes(&net->ipv4.ip_id_key, 490 sizeof(net->ipv4.ip_id_key)); 491 492 hash = siphash_3u32((__force u32)iph->daddr, 493 (__force u32)iph->saddr, 494 iph->protocol, 495 &net->ipv4.ip_id_key); 496 id = ip_idents_reserve(hash, segs); 497 iph->id = htons(id); 498 } 499 EXPORT_SYMBOL(__ip_select_ident); 500 501 static void ip_rt_fix_tos(struct flowi4 *fl4) 502 { 503 __u8 tos = RT_FL_TOS(fl4); 504 505 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 506 if (tos & RTO_ONLINK) 507 fl4->flowi4_scope = RT_SCOPE_LINK; 508 } 509 510 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 511 const struct sock *sk, const struct iphdr *iph, 512 int oif, __u8 tos, u8 prot, u32 mark, 513 int flow_flags) 514 { 515 __u8 scope = RT_SCOPE_UNIVERSE; 516 517 if (sk) { 518 const struct inet_sock *inet = inet_sk(sk); 519 520 oif = sk->sk_bound_dev_if; 521 mark = sk->sk_mark; 522 tos = ip_sock_rt_tos(sk); 523 scope = ip_sock_rt_scope(sk); 524 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 525 } 526 527 flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope, 528 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 529 sock_net_uid(net, sk)); 530 } 531 532 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 533 const struct sock *sk) 534 { 535 const struct net *net = dev_net(skb->dev); 536 const struct iphdr *iph = ip_hdr(skb); 537 int oif = skb->dev->ifindex; 538 u8 prot = iph->protocol; 539 u32 mark = skb->mark; 540 __u8 tos = iph->tos; 541 542 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 543 } 544 545 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 546 { 547 const struct inet_sock *inet = inet_sk(sk); 548 const struct ip_options_rcu *inet_opt; 549 __be32 daddr = inet->inet_daddr; 550 551 rcu_read_lock(); 552 inet_opt = rcu_dereference(inet->inet_opt); 553 if (inet_opt && inet_opt->opt.srr) 554 daddr = inet_opt->opt.faddr; 555 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 556 ip_sock_rt_tos(sk) & IPTOS_RT_MASK, 557 ip_sock_rt_scope(sk), 558 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 559 inet_sk_flowi_flags(sk), 560 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 561 rcu_read_unlock(); 562 } 563 564 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 565 const struct sk_buff *skb) 566 { 567 if (skb) 568 build_skb_flow_key(fl4, skb, sk); 569 else 570 build_sk_flow_key(fl4, sk); 571 } 572 573 static DEFINE_SPINLOCK(fnhe_lock); 574 575 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 576 { 577 struct rtable *rt; 578 579 rt = rcu_dereference(fnhe->fnhe_rth_input); 580 if (rt) { 581 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 582 dst_dev_put(&rt->dst); 583 dst_release(&rt->dst); 584 } 585 rt = rcu_dereference(fnhe->fnhe_rth_output); 586 if (rt) { 587 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 588 dst_dev_put(&rt->dst); 589 dst_release(&rt->dst); 590 } 591 } 592 593 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 594 { 595 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 596 struct fib_nh_exception *fnhe, *oldest = NULL; 597 598 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 599 fnhe = rcu_dereference_protected(*fnhe_p, 600 lockdep_is_held(&fnhe_lock)); 601 if (!fnhe) 602 break; 603 if (!oldest || 604 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 605 oldest = fnhe; 606 oldest_p = fnhe_p; 607 } 608 } 609 fnhe_flush_routes(oldest); 610 *oldest_p = oldest->fnhe_next; 611 kfree_rcu(oldest, rcu); 612 } 613 614 static u32 fnhe_hashfun(__be32 daddr) 615 { 616 static siphash_aligned_key_t fnhe_hash_key; 617 u64 hval; 618 619 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 620 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 621 return hash_64(hval, FNHE_HASH_SHIFT); 622 } 623 624 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 625 { 626 rt->rt_pmtu = fnhe->fnhe_pmtu; 627 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 628 rt->dst.expires = fnhe->fnhe_expires; 629 630 if (fnhe->fnhe_gw) { 631 rt->rt_flags |= RTCF_REDIRECTED; 632 rt->rt_uses_gateway = 1; 633 rt->rt_gw_family = AF_INET; 634 rt->rt_gw4 = fnhe->fnhe_gw; 635 } 636 } 637 638 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 639 __be32 gw, u32 pmtu, bool lock, 640 unsigned long expires) 641 { 642 struct fnhe_hash_bucket *hash; 643 struct fib_nh_exception *fnhe; 644 struct rtable *rt; 645 u32 genid, hval; 646 unsigned int i; 647 int depth; 648 649 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 650 hval = fnhe_hashfun(daddr); 651 652 spin_lock_bh(&fnhe_lock); 653 654 hash = rcu_dereference(nhc->nhc_exceptions); 655 if (!hash) { 656 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 657 if (!hash) 658 goto out_unlock; 659 rcu_assign_pointer(nhc->nhc_exceptions, hash); 660 } 661 662 hash += hval; 663 664 depth = 0; 665 for (fnhe = rcu_dereference(hash->chain); fnhe; 666 fnhe = rcu_dereference(fnhe->fnhe_next)) { 667 if (fnhe->fnhe_daddr == daddr) 668 break; 669 depth++; 670 } 671 672 if (fnhe) { 673 if (fnhe->fnhe_genid != genid) 674 fnhe->fnhe_genid = genid; 675 if (gw) 676 fnhe->fnhe_gw = gw; 677 if (pmtu) { 678 fnhe->fnhe_pmtu = pmtu; 679 fnhe->fnhe_mtu_locked = lock; 680 } 681 fnhe->fnhe_expires = max(1UL, expires); 682 /* Update all cached dsts too */ 683 rt = rcu_dereference(fnhe->fnhe_rth_input); 684 if (rt) 685 fill_route_from_fnhe(rt, fnhe); 686 rt = rcu_dereference(fnhe->fnhe_rth_output); 687 if (rt) 688 fill_route_from_fnhe(rt, fnhe); 689 } else { 690 /* Randomize max depth to avoid some side channels attacks. */ 691 int max_depth = FNHE_RECLAIM_DEPTH + 692 prandom_u32_max(FNHE_RECLAIM_DEPTH); 693 694 while (depth > max_depth) { 695 fnhe_remove_oldest(hash); 696 depth--; 697 } 698 699 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 700 if (!fnhe) 701 goto out_unlock; 702 703 fnhe->fnhe_next = hash->chain; 704 705 fnhe->fnhe_genid = genid; 706 fnhe->fnhe_daddr = daddr; 707 fnhe->fnhe_gw = gw; 708 fnhe->fnhe_pmtu = pmtu; 709 fnhe->fnhe_mtu_locked = lock; 710 fnhe->fnhe_expires = max(1UL, expires); 711 712 rcu_assign_pointer(hash->chain, fnhe); 713 714 /* Exception created; mark the cached routes for the nexthop 715 * stale, so anyone caching it rechecks if this exception 716 * applies to them. 717 */ 718 rt = rcu_dereference(nhc->nhc_rth_input); 719 if (rt) 720 rt->dst.obsolete = DST_OBSOLETE_KILL; 721 722 for_each_possible_cpu(i) { 723 struct rtable __rcu **prt; 724 725 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 726 rt = rcu_dereference(*prt); 727 if (rt) 728 rt->dst.obsolete = DST_OBSOLETE_KILL; 729 } 730 } 731 732 fnhe->fnhe_stamp = jiffies; 733 734 out_unlock: 735 spin_unlock_bh(&fnhe_lock); 736 } 737 738 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 739 bool kill_route) 740 { 741 __be32 new_gw = icmp_hdr(skb)->un.gateway; 742 __be32 old_gw = ip_hdr(skb)->saddr; 743 struct net_device *dev = skb->dev; 744 struct in_device *in_dev; 745 struct fib_result res; 746 struct neighbour *n; 747 struct net *net; 748 749 switch (icmp_hdr(skb)->code & 7) { 750 case ICMP_REDIR_NET: 751 case ICMP_REDIR_NETTOS: 752 case ICMP_REDIR_HOST: 753 case ICMP_REDIR_HOSTTOS: 754 break; 755 756 default: 757 return; 758 } 759 760 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 761 return; 762 763 in_dev = __in_dev_get_rcu(dev); 764 if (!in_dev) 765 return; 766 767 net = dev_net(dev); 768 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 769 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 770 ipv4_is_zeronet(new_gw)) 771 goto reject_redirect; 772 773 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 774 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 775 goto reject_redirect; 776 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 777 goto reject_redirect; 778 } else { 779 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 780 goto reject_redirect; 781 } 782 783 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 784 if (!n) 785 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 786 if (!IS_ERR(n)) { 787 if (!(n->nud_state & NUD_VALID)) { 788 neigh_event_send(n, NULL); 789 } else { 790 if (fib_lookup(net, fl4, &res, 0) == 0) { 791 struct fib_nh_common *nhc; 792 793 fib_select_path(net, &res, fl4, skb); 794 nhc = FIB_RES_NHC(res); 795 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 796 0, false, 797 jiffies + ip_rt_gc_timeout); 798 } 799 if (kill_route) 800 rt->dst.obsolete = DST_OBSOLETE_KILL; 801 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 802 } 803 neigh_release(n); 804 } 805 return; 806 807 reject_redirect: 808 #ifdef CONFIG_IP_ROUTE_VERBOSE 809 if (IN_DEV_LOG_MARTIANS(in_dev)) { 810 const struct iphdr *iph = (const struct iphdr *) skb->data; 811 __be32 daddr = iph->daddr; 812 __be32 saddr = iph->saddr; 813 814 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 815 " Advised path = %pI4 -> %pI4\n", 816 &old_gw, dev->name, &new_gw, 817 &saddr, &daddr); 818 } 819 #endif 820 ; 821 } 822 823 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 824 { 825 struct rtable *rt; 826 struct flowi4 fl4; 827 const struct iphdr *iph = (const struct iphdr *) skb->data; 828 struct net *net = dev_net(skb->dev); 829 int oif = skb->dev->ifindex; 830 u8 prot = iph->protocol; 831 u32 mark = skb->mark; 832 __u8 tos = iph->tos; 833 834 rt = (struct rtable *) dst; 835 836 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 837 __ip_do_redirect(rt, skb, &fl4, true); 838 } 839 840 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 841 { 842 struct rtable *rt = (struct rtable *)dst; 843 struct dst_entry *ret = dst; 844 845 if (rt) { 846 if (dst->obsolete > 0) { 847 ip_rt_put(rt); 848 ret = NULL; 849 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 850 rt->dst.expires) { 851 ip_rt_put(rt); 852 ret = NULL; 853 } 854 } 855 return ret; 856 } 857 858 /* 859 * Algorithm: 860 * 1. The first ip_rt_redirect_number redirects are sent 861 * with exponential backoff, then we stop sending them at all, 862 * assuming that the host ignores our redirects. 863 * 2. If we did not see packets requiring redirects 864 * during ip_rt_redirect_silence, we assume that the host 865 * forgot redirected route and start to send redirects again. 866 * 867 * This algorithm is much cheaper and more intelligent than dumb load limiting 868 * in icmp.c. 869 * 870 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 871 * and "frag. need" (breaks PMTU discovery) in icmp.c. 872 */ 873 874 void ip_rt_send_redirect(struct sk_buff *skb) 875 { 876 struct rtable *rt = skb_rtable(skb); 877 struct in_device *in_dev; 878 struct inet_peer *peer; 879 struct net *net; 880 int log_martians; 881 int vif; 882 883 rcu_read_lock(); 884 in_dev = __in_dev_get_rcu(rt->dst.dev); 885 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 886 rcu_read_unlock(); 887 return; 888 } 889 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 890 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 891 rcu_read_unlock(); 892 893 net = dev_net(rt->dst.dev); 894 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 895 if (!peer) { 896 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 897 rt_nexthop(rt, ip_hdr(skb)->daddr)); 898 return; 899 } 900 901 /* No redirected packets during ip_rt_redirect_silence; 902 * reset the algorithm. 903 */ 904 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 905 peer->rate_tokens = 0; 906 peer->n_redirects = 0; 907 } 908 909 /* Too many ignored redirects; do not send anything 910 * set dst.rate_last to the last seen redirected packet. 911 */ 912 if (peer->n_redirects >= ip_rt_redirect_number) { 913 peer->rate_last = jiffies; 914 goto out_put_peer; 915 } 916 917 /* Check for load limit; set rate_last to the latest sent 918 * redirect. 919 */ 920 if (peer->n_redirects == 0 || 921 time_after(jiffies, 922 (peer->rate_last + 923 (ip_rt_redirect_load << peer->n_redirects)))) { 924 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 925 926 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 927 peer->rate_last = jiffies; 928 ++peer->n_redirects; 929 #ifdef CONFIG_IP_ROUTE_VERBOSE 930 if (log_martians && 931 peer->n_redirects == ip_rt_redirect_number) 932 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 933 &ip_hdr(skb)->saddr, inet_iif(skb), 934 &ip_hdr(skb)->daddr, &gw); 935 #endif 936 } 937 out_put_peer: 938 inet_putpeer(peer); 939 } 940 941 static int ip_error(struct sk_buff *skb) 942 { 943 struct rtable *rt = skb_rtable(skb); 944 struct net_device *dev = skb->dev; 945 struct in_device *in_dev; 946 struct inet_peer *peer; 947 unsigned long now; 948 struct net *net; 949 SKB_DR(reason); 950 bool send; 951 int code; 952 953 if (netif_is_l3_master(skb->dev)) { 954 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 955 if (!dev) 956 goto out; 957 } 958 959 in_dev = __in_dev_get_rcu(dev); 960 961 /* IP on this device is disabled. */ 962 if (!in_dev) 963 goto out; 964 965 net = dev_net(rt->dst.dev); 966 if (!IN_DEV_FORWARD(in_dev)) { 967 switch (rt->dst.error) { 968 case EHOSTUNREACH: 969 SKB_DR_SET(reason, IP_INADDRERRORS); 970 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 971 break; 972 973 case ENETUNREACH: 974 SKB_DR_SET(reason, IP_INNOROUTES); 975 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 976 break; 977 } 978 goto out; 979 } 980 981 switch (rt->dst.error) { 982 case EINVAL: 983 default: 984 goto out; 985 case EHOSTUNREACH: 986 code = ICMP_HOST_UNREACH; 987 break; 988 case ENETUNREACH: 989 code = ICMP_NET_UNREACH; 990 SKB_DR_SET(reason, IP_INNOROUTES); 991 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 992 break; 993 case EACCES: 994 code = ICMP_PKT_FILTERED; 995 break; 996 } 997 998 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 999 l3mdev_master_ifindex(skb->dev), 1); 1000 1001 send = true; 1002 if (peer) { 1003 now = jiffies; 1004 peer->rate_tokens += now - peer->rate_last; 1005 if (peer->rate_tokens > ip_rt_error_burst) 1006 peer->rate_tokens = ip_rt_error_burst; 1007 peer->rate_last = now; 1008 if (peer->rate_tokens >= ip_rt_error_cost) 1009 peer->rate_tokens -= ip_rt_error_cost; 1010 else 1011 send = false; 1012 inet_putpeer(peer); 1013 } 1014 if (send) 1015 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1016 1017 out: kfree_skb_reason(skb, reason); 1018 return 0; 1019 } 1020 1021 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1022 { 1023 struct dst_entry *dst = &rt->dst; 1024 struct net *net = dev_net(dst->dev); 1025 struct fib_result res; 1026 bool lock = false; 1027 u32 old_mtu; 1028 1029 if (ip_mtu_locked(dst)) 1030 return; 1031 1032 old_mtu = ipv4_mtu(dst); 1033 if (old_mtu < mtu) 1034 return; 1035 1036 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1037 lock = true; 1038 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1039 } 1040 1041 if (rt->rt_pmtu == mtu && !lock && 1042 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1043 return; 1044 1045 rcu_read_lock(); 1046 if (fib_lookup(net, fl4, &res, 0) == 0) { 1047 struct fib_nh_common *nhc; 1048 1049 fib_select_path(net, &res, fl4, NULL); 1050 nhc = FIB_RES_NHC(res); 1051 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1052 jiffies + net->ipv4.ip_rt_mtu_expires); 1053 } 1054 rcu_read_unlock(); 1055 } 1056 1057 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1058 struct sk_buff *skb, u32 mtu, 1059 bool confirm_neigh) 1060 { 1061 struct rtable *rt = (struct rtable *) dst; 1062 struct flowi4 fl4; 1063 1064 ip_rt_build_flow_key(&fl4, sk, skb); 1065 1066 /* Don't make lookup fail for bridged encapsulations */ 1067 if (skb && netif_is_any_bridge_port(skb->dev)) 1068 fl4.flowi4_oif = 0; 1069 1070 __ip_rt_update_pmtu(rt, &fl4, mtu); 1071 } 1072 1073 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1074 int oif, u8 protocol) 1075 { 1076 const struct iphdr *iph = (const struct iphdr *)skb->data; 1077 struct flowi4 fl4; 1078 struct rtable *rt; 1079 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1080 1081 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1082 0); 1083 rt = __ip_route_output_key(net, &fl4); 1084 if (!IS_ERR(rt)) { 1085 __ip_rt_update_pmtu(rt, &fl4, mtu); 1086 ip_rt_put(rt); 1087 } 1088 } 1089 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1090 1091 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1092 { 1093 const struct iphdr *iph = (const struct iphdr *)skb->data; 1094 struct flowi4 fl4; 1095 struct rtable *rt; 1096 1097 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1098 1099 if (!fl4.flowi4_mark) 1100 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1101 1102 rt = __ip_route_output_key(sock_net(sk), &fl4); 1103 if (!IS_ERR(rt)) { 1104 __ip_rt_update_pmtu(rt, &fl4, mtu); 1105 ip_rt_put(rt); 1106 } 1107 } 1108 1109 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1110 { 1111 const struct iphdr *iph = (const struct iphdr *)skb->data; 1112 struct flowi4 fl4; 1113 struct rtable *rt; 1114 struct dst_entry *odst = NULL; 1115 bool new = false; 1116 struct net *net = sock_net(sk); 1117 1118 bh_lock_sock(sk); 1119 1120 if (!ip_sk_accept_pmtu(sk)) 1121 goto out; 1122 1123 odst = sk_dst_get(sk); 1124 1125 if (sock_owned_by_user(sk) || !odst) { 1126 __ipv4_sk_update_pmtu(skb, sk, mtu); 1127 goto out; 1128 } 1129 1130 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1131 1132 rt = (struct rtable *)odst; 1133 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1134 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1135 if (IS_ERR(rt)) 1136 goto out; 1137 1138 new = true; 1139 } 1140 1141 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1142 1143 if (!dst_check(&rt->dst, 0)) { 1144 if (new) 1145 dst_release(&rt->dst); 1146 1147 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1148 if (IS_ERR(rt)) 1149 goto out; 1150 1151 new = true; 1152 } 1153 1154 if (new) 1155 sk_dst_set(sk, &rt->dst); 1156 1157 out: 1158 bh_unlock_sock(sk); 1159 dst_release(odst); 1160 } 1161 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1162 1163 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1164 int oif, u8 protocol) 1165 { 1166 const struct iphdr *iph = (const struct iphdr *)skb->data; 1167 struct flowi4 fl4; 1168 struct rtable *rt; 1169 1170 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1171 rt = __ip_route_output_key(net, &fl4); 1172 if (!IS_ERR(rt)) { 1173 __ip_do_redirect(rt, skb, &fl4, false); 1174 ip_rt_put(rt); 1175 } 1176 } 1177 EXPORT_SYMBOL_GPL(ipv4_redirect); 1178 1179 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1180 { 1181 const struct iphdr *iph = (const struct iphdr *)skb->data; 1182 struct flowi4 fl4; 1183 struct rtable *rt; 1184 struct net *net = sock_net(sk); 1185 1186 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1187 rt = __ip_route_output_key(net, &fl4); 1188 if (!IS_ERR(rt)) { 1189 __ip_do_redirect(rt, skb, &fl4, false); 1190 ip_rt_put(rt); 1191 } 1192 } 1193 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1194 1195 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1196 u32 cookie) 1197 { 1198 struct rtable *rt = (struct rtable *) dst; 1199 1200 /* All IPV4 dsts are created with ->obsolete set to the value 1201 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1202 * into this function always. 1203 * 1204 * When a PMTU/redirect information update invalidates a route, 1205 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1206 * DST_OBSOLETE_DEAD. 1207 */ 1208 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1209 return NULL; 1210 return dst; 1211 } 1212 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1213 1214 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1215 { 1216 struct ip_options opt; 1217 int res; 1218 1219 /* Recompile ip options since IPCB may not be valid anymore. 1220 * Also check we have a reasonable ipv4 header. 1221 */ 1222 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1223 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1224 return; 1225 1226 memset(&opt, 0, sizeof(opt)); 1227 if (ip_hdr(skb)->ihl > 5) { 1228 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1229 return; 1230 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1231 1232 rcu_read_lock(); 1233 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1234 rcu_read_unlock(); 1235 1236 if (res) 1237 return; 1238 } 1239 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1240 } 1241 1242 static void ipv4_link_failure(struct sk_buff *skb) 1243 { 1244 struct rtable *rt; 1245 1246 ipv4_send_dest_unreach(skb); 1247 1248 rt = skb_rtable(skb); 1249 if (rt) 1250 dst_set_expires(&rt->dst, 0); 1251 } 1252 1253 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1254 { 1255 pr_debug("%s: %pI4 -> %pI4, %s\n", 1256 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1257 skb->dev ? skb->dev->name : "?"); 1258 kfree_skb(skb); 1259 WARN_ON(1); 1260 return 0; 1261 } 1262 1263 /* 1264 * We do not cache source address of outgoing interface, 1265 * because it is used only by IP RR, TS and SRR options, 1266 * so that it out of fast path. 1267 * 1268 * BTW remember: "addr" is allowed to be not aligned 1269 * in IP options! 1270 */ 1271 1272 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1273 { 1274 __be32 src; 1275 1276 if (rt_is_output_route(rt)) 1277 src = ip_hdr(skb)->saddr; 1278 else { 1279 struct fib_result res; 1280 struct iphdr *iph = ip_hdr(skb); 1281 struct flowi4 fl4 = { 1282 .daddr = iph->daddr, 1283 .saddr = iph->saddr, 1284 .flowi4_tos = RT_TOS(iph->tos), 1285 .flowi4_oif = rt->dst.dev->ifindex, 1286 .flowi4_iif = skb->dev->ifindex, 1287 .flowi4_mark = skb->mark, 1288 }; 1289 1290 rcu_read_lock(); 1291 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1292 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1293 else 1294 src = inet_select_addr(rt->dst.dev, 1295 rt_nexthop(rt, iph->daddr), 1296 RT_SCOPE_UNIVERSE); 1297 rcu_read_unlock(); 1298 } 1299 memcpy(addr, &src, 4); 1300 } 1301 1302 #ifdef CONFIG_IP_ROUTE_CLASSID 1303 static void set_class_tag(struct rtable *rt, u32 tag) 1304 { 1305 if (!(rt->dst.tclassid & 0xFFFF)) 1306 rt->dst.tclassid |= tag & 0xFFFF; 1307 if (!(rt->dst.tclassid & 0xFFFF0000)) 1308 rt->dst.tclassid |= tag & 0xFFFF0000; 1309 } 1310 #endif 1311 1312 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1313 { 1314 struct net *net = dev_net(dst->dev); 1315 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1316 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1317 net->ipv4.ip_rt_min_advmss); 1318 1319 return min(advmss, IPV4_MAX_PMTU - header_size); 1320 } 1321 1322 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1323 { 1324 return ip_dst_mtu_maybe_forward(dst, false); 1325 } 1326 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1327 1328 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1329 { 1330 struct fnhe_hash_bucket *hash; 1331 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1332 u32 hval = fnhe_hashfun(daddr); 1333 1334 spin_lock_bh(&fnhe_lock); 1335 1336 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1337 lockdep_is_held(&fnhe_lock)); 1338 hash += hval; 1339 1340 fnhe_p = &hash->chain; 1341 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1342 while (fnhe) { 1343 if (fnhe->fnhe_daddr == daddr) { 1344 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1345 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1346 /* set fnhe_daddr to 0 to ensure it won't bind with 1347 * new dsts in rt_bind_exception(). 1348 */ 1349 fnhe->fnhe_daddr = 0; 1350 fnhe_flush_routes(fnhe); 1351 kfree_rcu(fnhe, rcu); 1352 break; 1353 } 1354 fnhe_p = &fnhe->fnhe_next; 1355 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1356 lockdep_is_held(&fnhe_lock)); 1357 } 1358 1359 spin_unlock_bh(&fnhe_lock); 1360 } 1361 1362 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1363 __be32 daddr) 1364 { 1365 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1366 struct fib_nh_exception *fnhe; 1367 u32 hval; 1368 1369 if (!hash) 1370 return NULL; 1371 1372 hval = fnhe_hashfun(daddr); 1373 1374 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1375 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1376 if (fnhe->fnhe_daddr == daddr) { 1377 if (fnhe->fnhe_expires && 1378 time_after(jiffies, fnhe->fnhe_expires)) { 1379 ip_del_fnhe(nhc, daddr); 1380 break; 1381 } 1382 return fnhe; 1383 } 1384 } 1385 return NULL; 1386 } 1387 1388 /* MTU selection: 1389 * 1. mtu on route is locked - use it 1390 * 2. mtu from nexthop exception 1391 * 3. mtu from egress device 1392 */ 1393 1394 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1395 { 1396 struct fib_nh_common *nhc = res->nhc; 1397 struct net_device *dev = nhc->nhc_dev; 1398 struct fib_info *fi = res->fi; 1399 u32 mtu = 0; 1400 1401 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1402 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1403 mtu = fi->fib_mtu; 1404 1405 if (likely(!mtu)) { 1406 struct fib_nh_exception *fnhe; 1407 1408 fnhe = find_exception(nhc, daddr); 1409 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1410 mtu = fnhe->fnhe_pmtu; 1411 } 1412 1413 if (likely(!mtu)) 1414 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1415 1416 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1417 } 1418 1419 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1420 __be32 daddr, const bool do_cache) 1421 { 1422 bool ret = false; 1423 1424 spin_lock_bh(&fnhe_lock); 1425 1426 if (daddr == fnhe->fnhe_daddr) { 1427 struct rtable __rcu **porig; 1428 struct rtable *orig; 1429 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1430 1431 if (rt_is_input_route(rt)) 1432 porig = &fnhe->fnhe_rth_input; 1433 else 1434 porig = &fnhe->fnhe_rth_output; 1435 orig = rcu_dereference(*porig); 1436 1437 if (fnhe->fnhe_genid != genid) { 1438 fnhe->fnhe_genid = genid; 1439 fnhe->fnhe_gw = 0; 1440 fnhe->fnhe_pmtu = 0; 1441 fnhe->fnhe_expires = 0; 1442 fnhe->fnhe_mtu_locked = false; 1443 fnhe_flush_routes(fnhe); 1444 orig = NULL; 1445 } 1446 fill_route_from_fnhe(rt, fnhe); 1447 if (!rt->rt_gw4) { 1448 rt->rt_gw4 = daddr; 1449 rt->rt_gw_family = AF_INET; 1450 } 1451 1452 if (do_cache) { 1453 dst_hold(&rt->dst); 1454 rcu_assign_pointer(*porig, rt); 1455 if (orig) { 1456 dst_dev_put(&orig->dst); 1457 dst_release(&orig->dst); 1458 } 1459 ret = true; 1460 } 1461 1462 fnhe->fnhe_stamp = jiffies; 1463 } 1464 spin_unlock_bh(&fnhe_lock); 1465 1466 return ret; 1467 } 1468 1469 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1470 { 1471 struct rtable *orig, *prev, **p; 1472 bool ret = true; 1473 1474 if (rt_is_input_route(rt)) { 1475 p = (struct rtable **)&nhc->nhc_rth_input; 1476 } else { 1477 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1478 } 1479 orig = *p; 1480 1481 /* hold dst before doing cmpxchg() to avoid race condition 1482 * on this dst 1483 */ 1484 dst_hold(&rt->dst); 1485 prev = cmpxchg(p, orig, rt); 1486 if (prev == orig) { 1487 if (orig) { 1488 rt_add_uncached_list(orig); 1489 dst_release(&orig->dst); 1490 } 1491 } else { 1492 dst_release(&rt->dst); 1493 ret = false; 1494 } 1495 1496 return ret; 1497 } 1498 1499 struct uncached_list { 1500 spinlock_t lock; 1501 struct list_head head; 1502 struct list_head quarantine; 1503 }; 1504 1505 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1506 1507 void rt_add_uncached_list(struct rtable *rt) 1508 { 1509 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1510 1511 rt->rt_uncached_list = ul; 1512 1513 spin_lock_bh(&ul->lock); 1514 list_add_tail(&rt->rt_uncached, &ul->head); 1515 spin_unlock_bh(&ul->lock); 1516 } 1517 1518 void rt_del_uncached_list(struct rtable *rt) 1519 { 1520 if (!list_empty(&rt->rt_uncached)) { 1521 struct uncached_list *ul = rt->rt_uncached_list; 1522 1523 spin_lock_bh(&ul->lock); 1524 list_del_init(&rt->rt_uncached); 1525 spin_unlock_bh(&ul->lock); 1526 } 1527 } 1528 1529 static void ipv4_dst_destroy(struct dst_entry *dst) 1530 { 1531 struct rtable *rt = (struct rtable *)dst; 1532 1533 ip_dst_metrics_put(dst); 1534 rt_del_uncached_list(rt); 1535 } 1536 1537 void rt_flush_dev(struct net_device *dev) 1538 { 1539 struct rtable *rt, *safe; 1540 int cpu; 1541 1542 for_each_possible_cpu(cpu) { 1543 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1544 1545 if (list_empty(&ul->head)) 1546 continue; 1547 1548 spin_lock_bh(&ul->lock); 1549 list_for_each_entry_safe(rt, safe, &ul->head, rt_uncached) { 1550 if (rt->dst.dev != dev) 1551 continue; 1552 rt->dst.dev = blackhole_netdev; 1553 dev_replace_track(dev, blackhole_netdev, 1554 &rt->dst.dev_tracker, 1555 GFP_ATOMIC); 1556 list_move(&rt->rt_uncached, &ul->quarantine); 1557 } 1558 spin_unlock_bh(&ul->lock); 1559 } 1560 } 1561 1562 static bool rt_cache_valid(const struct rtable *rt) 1563 { 1564 return rt && 1565 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1566 !rt_is_expired(rt); 1567 } 1568 1569 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1570 const struct fib_result *res, 1571 struct fib_nh_exception *fnhe, 1572 struct fib_info *fi, u16 type, u32 itag, 1573 const bool do_cache) 1574 { 1575 bool cached = false; 1576 1577 if (fi) { 1578 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1579 1580 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1581 rt->rt_uses_gateway = 1; 1582 rt->rt_gw_family = nhc->nhc_gw_family; 1583 /* only INET and INET6 are supported */ 1584 if (likely(nhc->nhc_gw_family == AF_INET)) 1585 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1586 else 1587 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1588 } 1589 1590 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1591 1592 #ifdef CONFIG_IP_ROUTE_CLASSID 1593 if (nhc->nhc_family == AF_INET) { 1594 struct fib_nh *nh; 1595 1596 nh = container_of(nhc, struct fib_nh, nh_common); 1597 rt->dst.tclassid = nh->nh_tclassid; 1598 } 1599 #endif 1600 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1601 if (unlikely(fnhe)) 1602 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1603 else if (do_cache) 1604 cached = rt_cache_route(nhc, rt); 1605 if (unlikely(!cached)) { 1606 /* Routes we intend to cache in nexthop exception or 1607 * FIB nexthop have the DST_NOCACHE bit clear. 1608 * However, if we are unsuccessful at storing this 1609 * route into the cache we really need to set it. 1610 */ 1611 if (!rt->rt_gw4) { 1612 rt->rt_gw_family = AF_INET; 1613 rt->rt_gw4 = daddr; 1614 } 1615 rt_add_uncached_list(rt); 1616 } 1617 } else 1618 rt_add_uncached_list(rt); 1619 1620 #ifdef CONFIG_IP_ROUTE_CLASSID 1621 #ifdef CONFIG_IP_MULTIPLE_TABLES 1622 set_class_tag(rt, res->tclassid); 1623 #endif 1624 set_class_tag(rt, itag); 1625 #endif 1626 } 1627 1628 struct rtable *rt_dst_alloc(struct net_device *dev, 1629 unsigned int flags, u16 type, 1630 bool nopolicy, bool noxfrm) 1631 { 1632 struct rtable *rt; 1633 1634 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1635 (nopolicy ? DST_NOPOLICY : 0) | 1636 (noxfrm ? DST_NOXFRM : 0)); 1637 1638 if (rt) { 1639 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1640 rt->rt_flags = flags; 1641 rt->rt_type = type; 1642 rt->rt_is_input = 0; 1643 rt->rt_iif = 0; 1644 rt->rt_pmtu = 0; 1645 rt->rt_mtu_locked = 0; 1646 rt->rt_uses_gateway = 0; 1647 rt->rt_gw_family = 0; 1648 rt->rt_gw4 = 0; 1649 INIT_LIST_HEAD(&rt->rt_uncached); 1650 1651 rt->dst.output = ip_output; 1652 if (flags & RTCF_LOCAL) 1653 rt->dst.input = ip_local_deliver; 1654 } 1655 1656 return rt; 1657 } 1658 EXPORT_SYMBOL(rt_dst_alloc); 1659 1660 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1661 { 1662 struct rtable *new_rt; 1663 1664 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1665 rt->dst.flags); 1666 1667 if (new_rt) { 1668 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1669 new_rt->rt_flags = rt->rt_flags; 1670 new_rt->rt_type = rt->rt_type; 1671 new_rt->rt_is_input = rt->rt_is_input; 1672 new_rt->rt_iif = rt->rt_iif; 1673 new_rt->rt_pmtu = rt->rt_pmtu; 1674 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1675 new_rt->rt_gw_family = rt->rt_gw_family; 1676 if (rt->rt_gw_family == AF_INET) 1677 new_rt->rt_gw4 = rt->rt_gw4; 1678 else if (rt->rt_gw_family == AF_INET6) 1679 new_rt->rt_gw6 = rt->rt_gw6; 1680 INIT_LIST_HEAD(&new_rt->rt_uncached); 1681 1682 new_rt->dst.input = rt->dst.input; 1683 new_rt->dst.output = rt->dst.output; 1684 new_rt->dst.error = rt->dst.error; 1685 new_rt->dst.lastuse = jiffies; 1686 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1687 } 1688 return new_rt; 1689 } 1690 EXPORT_SYMBOL(rt_dst_clone); 1691 1692 /* called in rcu_read_lock() section */ 1693 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1694 u8 tos, struct net_device *dev, 1695 struct in_device *in_dev, u32 *itag) 1696 { 1697 int err; 1698 1699 /* Primary sanity checks. */ 1700 if (!in_dev) 1701 return -EINVAL; 1702 1703 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1704 skb->protocol != htons(ETH_P_IP)) 1705 return -EINVAL; 1706 1707 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1708 return -EINVAL; 1709 1710 if (ipv4_is_zeronet(saddr)) { 1711 if (!ipv4_is_local_multicast(daddr) && 1712 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1713 return -EINVAL; 1714 } else { 1715 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1716 in_dev, itag); 1717 if (err < 0) 1718 return err; 1719 } 1720 return 0; 1721 } 1722 1723 /* called in rcu_read_lock() section */ 1724 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1725 u8 tos, struct net_device *dev, int our) 1726 { 1727 struct in_device *in_dev = __in_dev_get_rcu(dev); 1728 unsigned int flags = RTCF_MULTICAST; 1729 struct rtable *rth; 1730 bool no_policy; 1731 u32 itag = 0; 1732 int err; 1733 1734 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1735 if (err) 1736 return err; 1737 1738 if (our) 1739 flags |= RTCF_LOCAL; 1740 1741 no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); 1742 if (no_policy) 1743 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1744 1745 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1746 no_policy, false); 1747 if (!rth) 1748 return -ENOBUFS; 1749 1750 #ifdef CONFIG_IP_ROUTE_CLASSID 1751 rth->dst.tclassid = itag; 1752 #endif 1753 rth->dst.output = ip_rt_bug; 1754 rth->rt_is_input= 1; 1755 1756 #ifdef CONFIG_IP_MROUTE 1757 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1758 rth->dst.input = ip_mr_input; 1759 #endif 1760 RT_CACHE_STAT_INC(in_slow_mc); 1761 1762 skb_dst_drop(skb); 1763 skb_dst_set(skb, &rth->dst); 1764 return 0; 1765 } 1766 1767 1768 static void ip_handle_martian_source(struct net_device *dev, 1769 struct in_device *in_dev, 1770 struct sk_buff *skb, 1771 __be32 daddr, 1772 __be32 saddr) 1773 { 1774 RT_CACHE_STAT_INC(in_martian_src); 1775 #ifdef CONFIG_IP_ROUTE_VERBOSE 1776 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1777 /* 1778 * RFC1812 recommendation, if source is martian, 1779 * the only hint is MAC header. 1780 */ 1781 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1782 &daddr, &saddr, dev->name); 1783 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1784 print_hex_dump(KERN_WARNING, "ll header: ", 1785 DUMP_PREFIX_OFFSET, 16, 1, 1786 skb_mac_header(skb), 1787 dev->hard_header_len, false); 1788 } 1789 } 1790 #endif 1791 } 1792 1793 /* called in rcu_read_lock() section */ 1794 static int __mkroute_input(struct sk_buff *skb, 1795 const struct fib_result *res, 1796 struct in_device *in_dev, 1797 __be32 daddr, __be32 saddr, u32 tos) 1798 { 1799 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1800 struct net_device *dev = nhc->nhc_dev; 1801 struct fib_nh_exception *fnhe; 1802 struct rtable *rth; 1803 int err; 1804 struct in_device *out_dev; 1805 bool do_cache, no_policy; 1806 u32 itag = 0; 1807 1808 /* get a working reference to the output device */ 1809 out_dev = __in_dev_get_rcu(dev); 1810 if (!out_dev) { 1811 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1812 return -EINVAL; 1813 } 1814 1815 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1816 in_dev->dev, in_dev, &itag); 1817 if (err < 0) { 1818 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1819 saddr); 1820 1821 goto cleanup; 1822 } 1823 1824 do_cache = res->fi && !itag; 1825 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1826 skb->protocol == htons(ETH_P_IP)) { 1827 __be32 gw; 1828 1829 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1830 if (IN_DEV_SHARED_MEDIA(out_dev) || 1831 inet_addr_onlink(out_dev, saddr, gw)) 1832 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1833 } 1834 1835 if (skb->protocol != htons(ETH_P_IP)) { 1836 /* Not IP (i.e. ARP). Do not create route, if it is 1837 * invalid for proxy arp. DNAT routes are always valid. 1838 * 1839 * Proxy arp feature have been extended to allow, ARP 1840 * replies back to the same interface, to support 1841 * Private VLAN switch technologies. See arp.c. 1842 */ 1843 if (out_dev == in_dev && 1844 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1845 err = -EINVAL; 1846 goto cleanup; 1847 } 1848 } 1849 1850 no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); 1851 if (no_policy) 1852 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1853 1854 fnhe = find_exception(nhc, daddr); 1855 if (do_cache) { 1856 if (fnhe) 1857 rth = rcu_dereference(fnhe->fnhe_rth_input); 1858 else 1859 rth = rcu_dereference(nhc->nhc_rth_input); 1860 if (rt_cache_valid(rth)) { 1861 skb_dst_set_noref(skb, &rth->dst); 1862 goto out; 1863 } 1864 } 1865 1866 rth = rt_dst_alloc(out_dev->dev, 0, res->type, no_policy, 1867 IN_DEV_ORCONF(out_dev, NOXFRM)); 1868 if (!rth) { 1869 err = -ENOBUFS; 1870 goto cleanup; 1871 } 1872 1873 rth->rt_is_input = 1; 1874 RT_CACHE_STAT_INC(in_slow_tot); 1875 1876 rth->dst.input = ip_forward; 1877 1878 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1879 do_cache); 1880 lwtunnel_set_redirect(&rth->dst); 1881 skb_dst_set(skb, &rth->dst); 1882 out: 1883 err = 0; 1884 cleanup: 1885 return err; 1886 } 1887 1888 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1889 /* To make ICMP packets follow the right flow, the multipath hash is 1890 * calculated from the inner IP addresses. 1891 */ 1892 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1893 struct flow_keys *hash_keys) 1894 { 1895 const struct iphdr *outer_iph = ip_hdr(skb); 1896 const struct iphdr *key_iph = outer_iph; 1897 const struct iphdr *inner_iph; 1898 const struct icmphdr *icmph; 1899 struct iphdr _inner_iph; 1900 struct icmphdr _icmph; 1901 1902 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1903 goto out; 1904 1905 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1906 goto out; 1907 1908 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1909 &_icmph); 1910 if (!icmph) 1911 goto out; 1912 1913 if (!icmp_is_err(icmph->type)) 1914 goto out; 1915 1916 inner_iph = skb_header_pointer(skb, 1917 outer_iph->ihl * 4 + sizeof(_icmph), 1918 sizeof(_inner_iph), &_inner_iph); 1919 if (!inner_iph) 1920 goto out; 1921 1922 key_iph = inner_iph; 1923 out: 1924 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1925 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1926 } 1927 1928 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1929 const struct sk_buff *skb, 1930 bool *p_has_inner) 1931 { 1932 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1933 struct flow_keys keys, hash_keys; 1934 1935 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1936 return 0; 1937 1938 memset(&hash_keys, 0, sizeof(hash_keys)); 1939 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1940 1941 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1942 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1943 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1944 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1945 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1946 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1947 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1948 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1949 hash_keys.ports.src = keys.ports.src; 1950 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1951 hash_keys.ports.dst = keys.ports.dst; 1952 1953 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1954 return flow_hash_from_keys(&hash_keys); 1955 } 1956 1957 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1958 const struct sk_buff *skb, 1959 bool has_inner) 1960 { 1961 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1962 struct flow_keys keys, hash_keys; 1963 1964 /* We assume the packet carries an encapsulation, but if none was 1965 * encountered during dissection of the outer flow, then there is no 1966 * point in calling the flow dissector again. 1967 */ 1968 if (!has_inner) 1969 return 0; 1970 1971 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1972 return 0; 1973 1974 memset(&hash_keys, 0, sizeof(hash_keys)); 1975 skb_flow_dissect_flow_keys(skb, &keys, 0); 1976 1977 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1978 return 0; 1979 1980 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1981 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1982 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1983 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1984 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1985 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1986 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1987 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1988 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1989 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1990 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1991 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1992 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1993 hash_keys.tags.flow_label = keys.tags.flow_label; 1994 } 1995 1996 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1997 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1998 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1999 hash_keys.ports.src = keys.ports.src; 2000 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2001 hash_keys.ports.dst = keys.ports.dst; 2002 2003 return flow_hash_from_keys(&hash_keys); 2004 } 2005 2006 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2007 const struct sk_buff *skb) 2008 { 2009 u32 mhash, mhash_inner; 2010 bool has_inner = true; 2011 2012 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2013 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2014 2015 return jhash_2words(mhash, mhash_inner, 0); 2016 } 2017 2018 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2019 const struct flowi4 *fl4) 2020 { 2021 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 2022 struct flow_keys hash_keys; 2023 2024 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2025 return 0; 2026 2027 memset(&hash_keys, 0, sizeof(hash_keys)); 2028 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2029 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2030 hash_keys.addrs.v4addrs.src = fl4->saddr; 2031 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2032 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2033 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2034 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2035 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2036 hash_keys.ports.src = fl4->fl4_sport; 2037 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2038 hash_keys.ports.dst = fl4->fl4_dport; 2039 2040 return flow_hash_from_keys(&hash_keys); 2041 } 2042 2043 /* if skb is set it will be used and fl4 can be NULL */ 2044 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2045 const struct sk_buff *skb, struct flow_keys *flkeys) 2046 { 2047 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2048 struct flow_keys hash_keys; 2049 u32 mhash = 0; 2050 2051 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2052 case 0: 2053 memset(&hash_keys, 0, sizeof(hash_keys)); 2054 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2055 if (skb) { 2056 ip_multipath_l3_keys(skb, &hash_keys); 2057 } else { 2058 hash_keys.addrs.v4addrs.src = fl4->saddr; 2059 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2060 } 2061 mhash = flow_hash_from_keys(&hash_keys); 2062 break; 2063 case 1: 2064 /* skb is currently provided only when forwarding */ 2065 if (skb) { 2066 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2067 struct flow_keys keys; 2068 2069 /* short-circuit if we already have L4 hash present */ 2070 if (skb->l4_hash) 2071 return skb_get_hash_raw(skb) >> 1; 2072 2073 memset(&hash_keys, 0, sizeof(hash_keys)); 2074 2075 if (!flkeys) { 2076 skb_flow_dissect_flow_keys(skb, &keys, flag); 2077 flkeys = &keys; 2078 } 2079 2080 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2081 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2082 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2083 hash_keys.ports.src = flkeys->ports.src; 2084 hash_keys.ports.dst = flkeys->ports.dst; 2085 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2086 } else { 2087 memset(&hash_keys, 0, sizeof(hash_keys)); 2088 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2089 hash_keys.addrs.v4addrs.src = fl4->saddr; 2090 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2091 hash_keys.ports.src = fl4->fl4_sport; 2092 hash_keys.ports.dst = fl4->fl4_dport; 2093 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2094 } 2095 mhash = flow_hash_from_keys(&hash_keys); 2096 break; 2097 case 2: 2098 memset(&hash_keys, 0, sizeof(hash_keys)); 2099 /* skb is currently provided only when forwarding */ 2100 if (skb) { 2101 struct flow_keys keys; 2102 2103 skb_flow_dissect_flow_keys(skb, &keys, 0); 2104 /* Inner can be v4 or v6 */ 2105 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2106 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2107 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2108 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2109 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2110 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2111 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2112 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2113 hash_keys.tags.flow_label = keys.tags.flow_label; 2114 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2115 } else { 2116 /* Same as case 0 */ 2117 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2118 ip_multipath_l3_keys(skb, &hash_keys); 2119 } 2120 } else { 2121 /* Same as case 0 */ 2122 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2123 hash_keys.addrs.v4addrs.src = fl4->saddr; 2124 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2125 } 2126 mhash = flow_hash_from_keys(&hash_keys); 2127 break; 2128 case 3: 2129 if (skb) 2130 mhash = fib_multipath_custom_hash_skb(net, skb); 2131 else 2132 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2133 break; 2134 } 2135 2136 if (multipath_hash) 2137 mhash = jhash_2words(mhash, multipath_hash, 0); 2138 2139 return mhash >> 1; 2140 } 2141 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2142 2143 static int ip_mkroute_input(struct sk_buff *skb, 2144 struct fib_result *res, 2145 struct in_device *in_dev, 2146 __be32 daddr, __be32 saddr, u32 tos, 2147 struct flow_keys *hkeys) 2148 { 2149 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2150 if (res->fi && fib_info_num_path(res->fi) > 1) { 2151 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2152 2153 fib_select_multipath(res, h); 2154 } 2155 #endif 2156 2157 /* create a routing cache entry */ 2158 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2159 } 2160 2161 /* Implements all the saddr-related checks as ip_route_input_slow(), 2162 * assuming daddr is valid and the destination is not a local broadcast one. 2163 * Uses the provided hint instead of performing a route lookup. 2164 */ 2165 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2166 u8 tos, struct net_device *dev, 2167 const struct sk_buff *hint) 2168 { 2169 struct in_device *in_dev = __in_dev_get_rcu(dev); 2170 struct rtable *rt = skb_rtable(hint); 2171 struct net *net = dev_net(dev); 2172 int err = -EINVAL; 2173 u32 tag = 0; 2174 2175 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2176 goto martian_source; 2177 2178 if (ipv4_is_zeronet(saddr)) 2179 goto martian_source; 2180 2181 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2182 goto martian_source; 2183 2184 if (rt->rt_type != RTN_LOCAL) 2185 goto skip_validate_source; 2186 2187 tos &= IPTOS_RT_MASK; 2188 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2189 if (err < 0) 2190 goto martian_source; 2191 2192 skip_validate_source: 2193 skb_dst_copy(skb, hint); 2194 return 0; 2195 2196 martian_source: 2197 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2198 return err; 2199 } 2200 2201 /* get device for dst_alloc with local routes */ 2202 static struct net_device *ip_rt_get_dev(struct net *net, 2203 const struct fib_result *res) 2204 { 2205 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2206 struct net_device *dev = NULL; 2207 2208 if (nhc) 2209 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2210 2211 return dev ? : net->loopback_dev; 2212 } 2213 2214 /* 2215 * NOTE. We drop all the packets that has local source 2216 * addresses, because every properly looped back packet 2217 * must have correct destination already attached by output routine. 2218 * Changes in the enforced policies must be applied also to 2219 * ip_route_use_hint(). 2220 * 2221 * Such approach solves two big problems: 2222 * 1. Not simplex devices are handled properly. 2223 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2224 * called with rcu_read_lock() 2225 */ 2226 2227 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2228 u8 tos, struct net_device *dev, 2229 struct fib_result *res) 2230 { 2231 struct in_device *in_dev = __in_dev_get_rcu(dev); 2232 struct flow_keys *flkeys = NULL, _flkeys; 2233 struct net *net = dev_net(dev); 2234 struct ip_tunnel_info *tun_info; 2235 int err = -EINVAL; 2236 unsigned int flags = 0; 2237 u32 itag = 0; 2238 struct rtable *rth; 2239 struct flowi4 fl4; 2240 bool do_cache = true; 2241 bool no_policy; 2242 2243 /* IP on this device is disabled. */ 2244 2245 if (!in_dev) 2246 goto out; 2247 2248 /* Check for the most weird martians, which can be not detected 2249 * by fib_lookup. 2250 */ 2251 2252 tun_info = skb_tunnel_info(skb); 2253 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2254 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2255 else 2256 fl4.flowi4_tun_key.tun_id = 0; 2257 skb_dst_drop(skb); 2258 2259 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2260 goto martian_source; 2261 2262 res->fi = NULL; 2263 res->table = NULL; 2264 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2265 goto brd_input; 2266 2267 /* Accept zero addresses only to limited broadcast; 2268 * I even do not know to fix it or not. Waiting for complains :-) 2269 */ 2270 if (ipv4_is_zeronet(saddr)) 2271 goto martian_source; 2272 2273 if (ipv4_is_zeronet(daddr)) 2274 goto martian_destination; 2275 2276 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2277 * and call it once if daddr or/and saddr are loopback addresses 2278 */ 2279 if (ipv4_is_loopback(daddr)) { 2280 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2281 goto martian_destination; 2282 } else if (ipv4_is_loopback(saddr)) { 2283 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2284 goto martian_source; 2285 } 2286 2287 /* 2288 * Now we are ready to route packet. 2289 */ 2290 fl4.flowi4_l3mdev = 0; 2291 fl4.flowi4_oif = 0; 2292 fl4.flowi4_iif = dev->ifindex; 2293 fl4.flowi4_mark = skb->mark; 2294 fl4.flowi4_tos = tos; 2295 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2296 fl4.flowi4_flags = 0; 2297 fl4.daddr = daddr; 2298 fl4.saddr = saddr; 2299 fl4.flowi4_uid = sock_net_uid(net, NULL); 2300 fl4.flowi4_multipath_hash = 0; 2301 2302 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2303 flkeys = &_flkeys; 2304 } else { 2305 fl4.flowi4_proto = 0; 2306 fl4.fl4_sport = 0; 2307 fl4.fl4_dport = 0; 2308 } 2309 2310 err = fib_lookup(net, &fl4, res, 0); 2311 if (err != 0) { 2312 if (!IN_DEV_FORWARD(in_dev)) 2313 err = -EHOSTUNREACH; 2314 goto no_route; 2315 } 2316 2317 if (res->type == RTN_BROADCAST) { 2318 if (IN_DEV_BFORWARD(in_dev)) 2319 goto make_route; 2320 /* not do cache if bc_forwarding is enabled */ 2321 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2322 do_cache = false; 2323 goto brd_input; 2324 } 2325 2326 if (res->type == RTN_LOCAL) { 2327 err = fib_validate_source(skb, saddr, daddr, tos, 2328 0, dev, in_dev, &itag); 2329 if (err < 0) 2330 goto martian_source; 2331 goto local_input; 2332 } 2333 2334 if (!IN_DEV_FORWARD(in_dev)) { 2335 err = -EHOSTUNREACH; 2336 goto no_route; 2337 } 2338 if (res->type != RTN_UNICAST) 2339 goto martian_destination; 2340 2341 make_route: 2342 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2343 out: return err; 2344 2345 brd_input: 2346 if (skb->protocol != htons(ETH_P_IP)) 2347 goto e_inval; 2348 2349 if (!ipv4_is_zeronet(saddr)) { 2350 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2351 in_dev, &itag); 2352 if (err < 0) 2353 goto martian_source; 2354 } 2355 flags |= RTCF_BROADCAST; 2356 res->type = RTN_BROADCAST; 2357 RT_CACHE_STAT_INC(in_brd); 2358 2359 local_input: 2360 no_policy = IN_DEV_ORCONF(in_dev, NOPOLICY); 2361 if (no_policy) 2362 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2363 2364 do_cache &= res->fi && !itag; 2365 if (do_cache) { 2366 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2367 2368 rth = rcu_dereference(nhc->nhc_rth_input); 2369 if (rt_cache_valid(rth)) { 2370 skb_dst_set_noref(skb, &rth->dst); 2371 err = 0; 2372 goto out; 2373 } 2374 } 2375 2376 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2377 flags | RTCF_LOCAL, res->type, 2378 no_policy, false); 2379 if (!rth) 2380 goto e_nobufs; 2381 2382 rth->dst.output= ip_rt_bug; 2383 #ifdef CONFIG_IP_ROUTE_CLASSID 2384 rth->dst.tclassid = itag; 2385 #endif 2386 rth->rt_is_input = 1; 2387 2388 RT_CACHE_STAT_INC(in_slow_tot); 2389 if (res->type == RTN_UNREACHABLE) { 2390 rth->dst.input= ip_error; 2391 rth->dst.error= -err; 2392 rth->rt_flags &= ~RTCF_LOCAL; 2393 } 2394 2395 if (do_cache) { 2396 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2397 2398 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2399 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2400 WARN_ON(rth->dst.input == lwtunnel_input); 2401 rth->dst.lwtstate->orig_input = rth->dst.input; 2402 rth->dst.input = lwtunnel_input; 2403 } 2404 2405 if (unlikely(!rt_cache_route(nhc, rth))) 2406 rt_add_uncached_list(rth); 2407 } 2408 skb_dst_set(skb, &rth->dst); 2409 err = 0; 2410 goto out; 2411 2412 no_route: 2413 RT_CACHE_STAT_INC(in_no_route); 2414 res->type = RTN_UNREACHABLE; 2415 res->fi = NULL; 2416 res->table = NULL; 2417 goto local_input; 2418 2419 /* 2420 * Do not cache martian addresses: they should be logged (RFC1812) 2421 */ 2422 martian_destination: 2423 RT_CACHE_STAT_INC(in_martian_dst); 2424 #ifdef CONFIG_IP_ROUTE_VERBOSE 2425 if (IN_DEV_LOG_MARTIANS(in_dev)) 2426 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2427 &daddr, &saddr, dev->name); 2428 #endif 2429 2430 e_inval: 2431 err = -EINVAL; 2432 goto out; 2433 2434 e_nobufs: 2435 err = -ENOBUFS; 2436 goto out; 2437 2438 martian_source: 2439 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2440 goto out; 2441 } 2442 2443 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2444 u8 tos, struct net_device *dev) 2445 { 2446 struct fib_result res; 2447 int err; 2448 2449 tos &= IPTOS_RT_MASK; 2450 rcu_read_lock(); 2451 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2452 rcu_read_unlock(); 2453 2454 return err; 2455 } 2456 EXPORT_SYMBOL(ip_route_input_noref); 2457 2458 /* called with rcu_read_lock held */ 2459 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2460 u8 tos, struct net_device *dev, struct fib_result *res) 2461 { 2462 /* Multicast recognition logic is moved from route cache to here. 2463 * The problem was that too many Ethernet cards have broken/missing 2464 * hardware multicast filters :-( As result the host on multicasting 2465 * network acquires a lot of useless route cache entries, sort of 2466 * SDR messages from all the world. Now we try to get rid of them. 2467 * Really, provided software IP multicast filter is organized 2468 * reasonably (at least, hashed), it does not result in a slowdown 2469 * comparing with route cache reject entries. 2470 * Note, that multicast routers are not affected, because 2471 * route cache entry is created eventually. 2472 */ 2473 if (ipv4_is_multicast(daddr)) { 2474 struct in_device *in_dev = __in_dev_get_rcu(dev); 2475 int our = 0; 2476 int err = -EINVAL; 2477 2478 if (!in_dev) 2479 return err; 2480 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2481 ip_hdr(skb)->protocol); 2482 2483 /* check l3 master if no match yet */ 2484 if (!our && netif_is_l3_slave(dev)) { 2485 struct in_device *l3_in_dev; 2486 2487 l3_in_dev = __in_dev_get_rcu(skb->dev); 2488 if (l3_in_dev) 2489 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2490 ip_hdr(skb)->protocol); 2491 } 2492 2493 if (our 2494 #ifdef CONFIG_IP_MROUTE 2495 || 2496 (!ipv4_is_local_multicast(daddr) && 2497 IN_DEV_MFORWARD(in_dev)) 2498 #endif 2499 ) { 2500 err = ip_route_input_mc(skb, daddr, saddr, 2501 tos, dev, our); 2502 } 2503 return err; 2504 } 2505 2506 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2507 } 2508 2509 /* called with rcu_read_lock() */ 2510 static struct rtable *__mkroute_output(const struct fib_result *res, 2511 const struct flowi4 *fl4, int orig_oif, 2512 struct net_device *dev_out, 2513 unsigned int flags) 2514 { 2515 struct fib_info *fi = res->fi; 2516 struct fib_nh_exception *fnhe; 2517 struct in_device *in_dev; 2518 u16 type = res->type; 2519 struct rtable *rth; 2520 bool do_cache; 2521 2522 in_dev = __in_dev_get_rcu(dev_out); 2523 if (!in_dev) 2524 return ERR_PTR(-EINVAL); 2525 2526 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2527 if (ipv4_is_loopback(fl4->saddr) && 2528 !(dev_out->flags & IFF_LOOPBACK) && 2529 !netif_is_l3_master(dev_out)) 2530 return ERR_PTR(-EINVAL); 2531 2532 if (ipv4_is_lbcast(fl4->daddr)) 2533 type = RTN_BROADCAST; 2534 else if (ipv4_is_multicast(fl4->daddr)) 2535 type = RTN_MULTICAST; 2536 else if (ipv4_is_zeronet(fl4->daddr)) 2537 return ERR_PTR(-EINVAL); 2538 2539 if (dev_out->flags & IFF_LOOPBACK) 2540 flags |= RTCF_LOCAL; 2541 2542 do_cache = true; 2543 if (type == RTN_BROADCAST) { 2544 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2545 fi = NULL; 2546 } else if (type == RTN_MULTICAST) { 2547 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2548 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2549 fl4->flowi4_proto)) 2550 flags &= ~RTCF_LOCAL; 2551 else 2552 do_cache = false; 2553 /* If multicast route do not exist use 2554 * default one, but do not gateway in this case. 2555 * Yes, it is hack. 2556 */ 2557 if (fi && res->prefixlen < 4) 2558 fi = NULL; 2559 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2560 (orig_oif != dev_out->ifindex)) { 2561 /* For local routes that require a particular output interface 2562 * we do not want to cache the result. Caching the result 2563 * causes incorrect behaviour when there are multiple source 2564 * addresses on the interface, the end result being that if the 2565 * intended recipient is waiting on that interface for the 2566 * packet he won't receive it because it will be delivered on 2567 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2568 * be set to the loopback interface as well. 2569 */ 2570 do_cache = false; 2571 } 2572 2573 fnhe = NULL; 2574 do_cache &= fi != NULL; 2575 if (fi) { 2576 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2577 struct rtable __rcu **prth; 2578 2579 fnhe = find_exception(nhc, fl4->daddr); 2580 if (!do_cache) 2581 goto add; 2582 if (fnhe) { 2583 prth = &fnhe->fnhe_rth_output; 2584 } else { 2585 if (unlikely(fl4->flowi4_flags & 2586 FLOWI_FLAG_KNOWN_NH && 2587 !(nhc->nhc_gw_family && 2588 nhc->nhc_scope == RT_SCOPE_LINK))) { 2589 do_cache = false; 2590 goto add; 2591 } 2592 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2593 } 2594 rth = rcu_dereference(*prth); 2595 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2596 return rth; 2597 } 2598 2599 add: 2600 rth = rt_dst_alloc(dev_out, flags, type, 2601 IN_DEV_ORCONF(in_dev, NOPOLICY), 2602 IN_DEV_ORCONF(in_dev, NOXFRM)); 2603 if (!rth) 2604 return ERR_PTR(-ENOBUFS); 2605 2606 rth->rt_iif = orig_oif; 2607 2608 RT_CACHE_STAT_INC(out_slow_tot); 2609 2610 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2611 if (flags & RTCF_LOCAL && 2612 !(dev_out->flags & IFF_LOOPBACK)) { 2613 rth->dst.output = ip_mc_output; 2614 RT_CACHE_STAT_INC(out_slow_mc); 2615 } 2616 #ifdef CONFIG_IP_MROUTE 2617 if (type == RTN_MULTICAST) { 2618 if (IN_DEV_MFORWARD(in_dev) && 2619 !ipv4_is_local_multicast(fl4->daddr)) { 2620 rth->dst.input = ip_mr_input; 2621 rth->dst.output = ip_mc_output; 2622 } 2623 } 2624 #endif 2625 } 2626 2627 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2628 lwtunnel_set_redirect(&rth->dst); 2629 2630 return rth; 2631 } 2632 2633 /* 2634 * Major route resolver routine. 2635 */ 2636 2637 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2638 const struct sk_buff *skb) 2639 { 2640 struct fib_result res = { 2641 .type = RTN_UNSPEC, 2642 .fi = NULL, 2643 .table = NULL, 2644 .tclassid = 0, 2645 }; 2646 struct rtable *rth; 2647 2648 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2649 ip_rt_fix_tos(fl4); 2650 2651 rcu_read_lock(); 2652 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2653 rcu_read_unlock(); 2654 2655 return rth; 2656 } 2657 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2658 2659 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2660 struct fib_result *res, 2661 const struct sk_buff *skb) 2662 { 2663 struct net_device *dev_out = NULL; 2664 int orig_oif = fl4->flowi4_oif; 2665 unsigned int flags = 0; 2666 struct rtable *rth; 2667 int err; 2668 2669 if (fl4->saddr) { 2670 if (ipv4_is_multicast(fl4->saddr) || 2671 ipv4_is_lbcast(fl4->saddr) || 2672 ipv4_is_zeronet(fl4->saddr)) { 2673 rth = ERR_PTR(-EINVAL); 2674 goto out; 2675 } 2676 2677 rth = ERR_PTR(-ENETUNREACH); 2678 2679 /* I removed check for oif == dev_out->oif here. 2680 * It was wrong for two reasons: 2681 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2682 * is assigned to multiple interfaces. 2683 * 2. Moreover, we are allowed to send packets with saddr 2684 * of another iface. --ANK 2685 */ 2686 2687 if (fl4->flowi4_oif == 0 && 2688 (ipv4_is_multicast(fl4->daddr) || 2689 ipv4_is_lbcast(fl4->daddr))) { 2690 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2691 dev_out = __ip_dev_find(net, fl4->saddr, false); 2692 if (!dev_out) 2693 goto out; 2694 2695 /* Special hack: user can direct multicasts 2696 * and limited broadcast via necessary interface 2697 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2698 * This hack is not just for fun, it allows 2699 * vic,vat and friends to work. 2700 * They bind socket to loopback, set ttl to zero 2701 * and expect that it will work. 2702 * From the viewpoint of routing cache they are broken, 2703 * because we are not allowed to build multicast path 2704 * with loopback source addr (look, routing cache 2705 * cannot know, that ttl is zero, so that packet 2706 * will not leave this host and route is valid). 2707 * Luckily, this hack is good workaround. 2708 */ 2709 2710 fl4->flowi4_oif = dev_out->ifindex; 2711 goto make_route; 2712 } 2713 2714 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2715 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2716 if (!__ip_dev_find(net, fl4->saddr, false)) 2717 goto out; 2718 } 2719 } 2720 2721 2722 if (fl4->flowi4_oif) { 2723 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2724 rth = ERR_PTR(-ENODEV); 2725 if (!dev_out) 2726 goto out; 2727 2728 /* RACE: Check return value of inet_select_addr instead. */ 2729 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2730 rth = ERR_PTR(-ENETUNREACH); 2731 goto out; 2732 } 2733 if (ipv4_is_local_multicast(fl4->daddr) || 2734 ipv4_is_lbcast(fl4->daddr) || 2735 fl4->flowi4_proto == IPPROTO_IGMP) { 2736 if (!fl4->saddr) 2737 fl4->saddr = inet_select_addr(dev_out, 0, 2738 RT_SCOPE_LINK); 2739 goto make_route; 2740 } 2741 if (!fl4->saddr) { 2742 if (ipv4_is_multicast(fl4->daddr)) 2743 fl4->saddr = inet_select_addr(dev_out, 0, 2744 fl4->flowi4_scope); 2745 else if (!fl4->daddr) 2746 fl4->saddr = inet_select_addr(dev_out, 0, 2747 RT_SCOPE_HOST); 2748 } 2749 } 2750 2751 if (!fl4->daddr) { 2752 fl4->daddr = fl4->saddr; 2753 if (!fl4->daddr) 2754 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2755 dev_out = net->loopback_dev; 2756 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2757 res->type = RTN_LOCAL; 2758 flags |= RTCF_LOCAL; 2759 goto make_route; 2760 } 2761 2762 err = fib_lookup(net, fl4, res, 0); 2763 if (err) { 2764 res->fi = NULL; 2765 res->table = NULL; 2766 if (fl4->flowi4_oif && 2767 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2768 /* Apparently, routing tables are wrong. Assume, 2769 * that the destination is on link. 2770 * 2771 * WHY? DW. 2772 * Because we are allowed to send to iface 2773 * even if it has NO routes and NO assigned 2774 * addresses. When oif is specified, routing 2775 * tables are looked up with only one purpose: 2776 * to catch if destination is gatewayed, rather than 2777 * direct. Moreover, if MSG_DONTROUTE is set, 2778 * we send packet, ignoring both routing tables 2779 * and ifaddr state. --ANK 2780 * 2781 * 2782 * We could make it even if oif is unknown, 2783 * likely IPv6, but we do not. 2784 */ 2785 2786 if (fl4->saddr == 0) 2787 fl4->saddr = inet_select_addr(dev_out, 0, 2788 RT_SCOPE_LINK); 2789 res->type = RTN_UNICAST; 2790 goto make_route; 2791 } 2792 rth = ERR_PTR(err); 2793 goto out; 2794 } 2795 2796 if (res->type == RTN_LOCAL) { 2797 if (!fl4->saddr) { 2798 if (res->fi->fib_prefsrc) 2799 fl4->saddr = res->fi->fib_prefsrc; 2800 else 2801 fl4->saddr = fl4->daddr; 2802 } 2803 2804 /* L3 master device is the loopback for that domain */ 2805 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2806 net->loopback_dev; 2807 2808 /* make sure orig_oif points to fib result device even 2809 * though packet rx/tx happens over loopback or l3mdev 2810 */ 2811 orig_oif = FIB_RES_OIF(*res); 2812 2813 fl4->flowi4_oif = dev_out->ifindex; 2814 flags |= RTCF_LOCAL; 2815 goto make_route; 2816 } 2817 2818 fib_select_path(net, res, fl4, skb); 2819 2820 dev_out = FIB_RES_DEV(*res); 2821 2822 make_route: 2823 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2824 2825 out: 2826 return rth; 2827 } 2828 2829 static struct dst_ops ipv4_dst_blackhole_ops = { 2830 .family = AF_INET, 2831 .default_advmss = ipv4_default_advmss, 2832 .neigh_lookup = ipv4_neigh_lookup, 2833 .check = dst_blackhole_check, 2834 .cow_metrics = dst_blackhole_cow_metrics, 2835 .update_pmtu = dst_blackhole_update_pmtu, 2836 .redirect = dst_blackhole_redirect, 2837 .mtu = dst_blackhole_mtu, 2838 }; 2839 2840 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2841 { 2842 struct rtable *ort = (struct rtable *) dst_orig; 2843 struct rtable *rt; 2844 2845 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2846 if (rt) { 2847 struct dst_entry *new = &rt->dst; 2848 2849 new->__use = 1; 2850 new->input = dst_discard; 2851 new->output = dst_discard_out; 2852 2853 new->dev = net->loopback_dev; 2854 dev_hold_track(new->dev, &new->dev_tracker, GFP_ATOMIC); 2855 2856 rt->rt_is_input = ort->rt_is_input; 2857 rt->rt_iif = ort->rt_iif; 2858 rt->rt_pmtu = ort->rt_pmtu; 2859 rt->rt_mtu_locked = ort->rt_mtu_locked; 2860 2861 rt->rt_genid = rt_genid_ipv4(net); 2862 rt->rt_flags = ort->rt_flags; 2863 rt->rt_type = ort->rt_type; 2864 rt->rt_uses_gateway = ort->rt_uses_gateway; 2865 rt->rt_gw_family = ort->rt_gw_family; 2866 if (rt->rt_gw_family == AF_INET) 2867 rt->rt_gw4 = ort->rt_gw4; 2868 else if (rt->rt_gw_family == AF_INET6) 2869 rt->rt_gw6 = ort->rt_gw6; 2870 2871 INIT_LIST_HEAD(&rt->rt_uncached); 2872 } 2873 2874 dst_release(dst_orig); 2875 2876 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2877 } 2878 2879 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2880 const struct sock *sk) 2881 { 2882 struct rtable *rt = __ip_route_output_key(net, flp4); 2883 2884 if (IS_ERR(rt)) 2885 return rt; 2886 2887 if (flp4->flowi4_proto) { 2888 flp4->flowi4_oif = rt->dst.dev->ifindex; 2889 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2890 flowi4_to_flowi(flp4), 2891 sk, 0); 2892 } 2893 2894 return rt; 2895 } 2896 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2897 2898 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2899 struct net_device *dev, 2900 struct net *net, __be32 *saddr, 2901 const struct ip_tunnel_info *info, 2902 u8 protocol, bool use_cache) 2903 { 2904 #ifdef CONFIG_DST_CACHE 2905 struct dst_cache *dst_cache; 2906 #endif 2907 struct rtable *rt = NULL; 2908 struct flowi4 fl4; 2909 __u8 tos; 2910 2911 #ifdef CONFIG_DST_CACHE 2912 dst_cache = (struct dst_cache *)&info->dst_cache; 2913 if (use_cache) { 2914 rt = dst_cache_get_ip4(dst_cache, saddr); 2915 if (rt) 2916 return rt; 2917 } 2918 #endif 2919 memset(&fl4, 0, sizeof(fl4)); 2920 fl4.flowi4_mark = skb->mark; 2921 fl4.flowi4_proto = protocol; 2922 fl4.daddr = info->key.u.ipv4.dst; 2923 fl4.saddr = info->key.u.ipv4.src; 2924 tos = info->key.tos; 2925 fl4.flowi4_tos = RT_TOS(tos); 2926 2927 rt = ip_route_output_key(net, &fl4); 2928 if (IS_ERR(rt)) { 2929 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2930 return ERR_PTR(-ENETUNREACH); 2931 } 2932 if (rt->dst.dev == dev) { /* is this necessary? */ 2933 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2934 ip_rt_put(rt); 2935 return ERR_PTR(-ELOOP); 2936 } 2937 #ifdef CONFIG_DST_CACHE 2938 if (use_cache) 2939 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2940 #endif 2941 *saddr = fl4.saddr; 2942 return rt; 2943 } 2944 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2945 2946 /* called with rcu_read_lock held */ 2947 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2948 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2949 struct sk_buff *skb, u32 portid, u32 seq, 2950 unsigned int flags) 2951 { 2952 struct rtmsg *r; 2953 struct nlmsghdr *nlh; 2954 unsigned long expires = 0; 2955 u32 error; 2956 u32 metrics[RTAX_MAX]; 2957 2958 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2959 if (!nlh) 2960 return -EMSGSIZE; 2961 2962 r = nlmsg_data(nlh); 2963 r->rtm_family = AF_INET; 2964 r->rtm_dst_len = 32; 2965 r->rtm_src_len = 0; 2966 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2967 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2968 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2969 goto nla_put_failure; 2970 r->rtm_type = rt->rt_type; 2971 r->rtm_scope = RT_SCOPE_UNIVERSE; 2972 r->rtm_protocol = RTPROT_UNSPEC; 2973 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2974 if (rt->rt_flags & RTCF_NOTIFY) 2975 r->rtm_flags |= RTM_F_NOTIFY; 2976 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2977 r->rtm_flags |= RTCF_DOREDIRECT; 2978 2979 if (nla_put_in_addr(skb, RTA_DST, dst)) 2980 goto nla_put_failure; 2981 if (src) { 2982 r->rtm_src_len = 32; 2983 if (nla_put_in_addr(skb, RTA_SRC, src)) 2984 goto nla_put_failure; 2985 } 2986 if (rt->dst.dev && 2987 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2988 goto nla_put_failure; 2989 if (rt->dst.lwtstate && 2990 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2991 goto nla_put_failure; 2992 #ifdef CONFIG_IP_ROUTE_CLASSID 2993 if (rt->dst.tclassid && 2994 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2995 goto nla_put_failure; 2996 #endif 2997 if (fl4 && !rt_is_input_route(rt) && 2998 fl4->saddr != src) { 2999 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 3000 goto nla_put_failure; 3001 } 3002 if (rt->rt_uses_gateway) { 3003 if (rt->rt_gw_family == AF_INET && 3004 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3005 goto nla_put_failure; 3006 } else if (rt->rt_gw_family == AF_INET6) { 3007 int alen = sizeof(struct in6_addr); 3008 struct nlattr *nla; 3009 struct rtvia *via; 3010 3011 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3012 if (!nla) 3013 goto nla_put_failure; 3014 3015 via = nla_data(nla); 3016 via->rtvia_family = AF_INET6; 3017 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3018 } 3019 } 3020 3021 expires = rt->dst.expires; 3022 if (expires) { 3023 unsigned long now = jiffies; 3024 3025 if (time_before(now, expires)) 3026 expires -= now; 3027 else 3028 expires = 0; 3029 } 3030 3031 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3032 if (rt->rt_pmtu && expires) 3033 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3034 if (rt->rt_mtu_locked && expires) 3035 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3036 if (rtnetlink_put_metrics(skb, metrics) < 0) 3037 goto nla_put_failure; 3038 3039 if (fl4) { 3040 if (fl4->flowi4_mark && 3041 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3042 goto nla_put_failure; 3043 3044 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3045 nla_put_u32(skb, RTA_UID, 3046 from_kuid_munged(current_user_ns(), 3047 fl4->flowi4_uid))) 3048 goto nla_put_failure; 3049 3050 if (rt_is_input_route(rt)) { 3051 #ifdef CONFIG_IP_MROUTE 3052 if (ipv4_is_multicast(dst) && 3053 !ipv4_is_local_multicast(dst) && 3054 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3055 int err = ipmr_get_route(net, skb, 3056 fl4->saddr, fl4->daddr, 3057 r, portid); 3058 3059 if (err <= 0) { 3060 if (err == 0) 3061 return 0; 3062 goto nla_put_failure; 3063 } 3064 } else 3065 #endif 3066 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3067 goto nla_put_failure; 3068 } 3069 } 3070 3071 error = rt->dst.error; 3072 3073 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3074 goto nla_put_failure; 3075 3076 nlmsg_end(skb, nlh); 3077 return 0; 3078 3079 nla_put_failure: 3080 nlmsg_cancel(skb, nlh); 3081 return -EMSGSIZE; 3082 } 3083 3084 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3085 struct netlink_callback *cb, u32 table_id, 3086 struct fnhe_hash_bucket *bucket, int genid, 3087 int *fa_index, int fa_start, unsigned int flags) 3088 { 3089 int i; 3090 3091 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3092 struct fib_nh_exception *fnhe; 3093 3094 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3095 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3096 struct rtable *rt; 3097 int err; 3098 3099 if (*fa_index < fa_start) 3100 goto next; 3101 3102 if (fnhe->fnhe_genid != genid) 3103 goto next; 3104 3105 if (fnhe->fnhe_expires && 3106 time_after(jiffies, fnhe->fnhe_expires)) 3107 goto next; 3108 3109 rt = rcu_dereference(fnhe->fnhe_rth_input); 3110 if (!rt) 3111 rt = rcu_dereference(fnhe->fnhe_rth_output); 3112 if (!rt) 3113 goto next; 3114 3115 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3116 table_id, NULL, skb, 3117 NETLINK_CB(cb->skb).portid, 3118 cb->nlh->nlmsg_seq, flags); 3119 if (err) 3120 return err; 3121 next: 3122 (*fa_index)++; 3123 } 3124 } 3125 3126 return 0; 3127 } 3128 3129 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3130 u32 table_id, struct fib_info *fi, 3131 int *fa_index, int fa_start, unsigned int flags) 3132 { 3133 struct net *net = sock_net(cb->skb->sk); 3134 int nhsel, genid = fnhe_genid(net); 3135 3136 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3137 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3138 struct fnhe_hash_bucket *bucket; 3139 int err; 3140 3141 if (nhc->nhc_flags & RTNH_F_DEAD) 3142 continue; 3143 3144 rcu_read_lock(); 3145 bucket = rcu_dereference(nhc->nhc_exceptions); 3146 err = 0; 3147 if (bucket) 3148 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3149 genid, fa_index, fa_start, 3150 flags); 3151 rcu_read_unlock(); 3152 if (err) 3153 return err; 3154 } 3155 3156 return 0; 3157 } 3158 3159 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3160 u8 ip_proto, __be16 sport, 3161 __be16 dport) 3162 { 3163 struct sk_buff *skb; 3164 struct iphdr *iph; 3165 3166 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3167 if (!skb) 3168 return NULL; 3169 3170 /* Reserve room for dummy headers, this skb can pass 3171 * through good chunk of routing engine. 3172 */ 3173 skb_reset_mac_header(skb); 3174 skb_reset_network_header(skb); 3175 skb->protocol = htons(ETH_P_IP); 3176 iph = skb_put(skb, sizeof(struct iphdr)); 3177 iph->protocol = ip_proto; 3178 iph->saddr = src; 3179 iph->daddr = dst; 3180 iph->version = 0x4; 3181 iph->frag_off = 0; 3182 iph->ihl = 0x5; 3183 skb_set_transport_header(skb, skb->len); 3184 3185 switch (iph->protocol) { 3186 case IPPROTO_UDP: { 3187 struct udphdr *udph; 3188 3189 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3190 udph->source = sport; 3191 udph->dest = dport; 3192 udph->len = htons(sizeof(struct udphdr)); 3193 udph->check = 0; 3194 break; 3195 } 3196 case IPPROTO_TCP: { 3197 struct tcphdr *tcph; 3198 3199 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3200 tcph->source = sport; 3201 tcph->dest = dport; 3202 tcph->doff = sizeof(struct tcphdr) / 4; 3203 tcph->rst = 1; 3204 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3205 src, dst, 0); 3206 break; 3207 } 3208 case IPPROTO_ICMP: { 3209 struct icmphdr *icmph; 3210 3211 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3212 icmph->type = ICMP_ECHO; 3213 icmph->code = 0; 3214 } 3215 } 3216 3217 return skb; 3218 } 3219 3220 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3221 const struct nlmsghdr *nlh, 3222 struct nlattr **tb, 3223 struct netlink_ext_ack *extack) 3224 { 3225 struct rtmsg *rtm; 3226 int i, err; 3227 3228 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3229 NL_SET_ERR_MSG(extack, 3230 "ipv4: Invalid header for route get request"); 3231 return -EINVAL; 3232 } 3233 3234 if (!netlink_strict_get_check(skb)) 3235 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3236 rtm_ipv4_policy, extack); 3237 3238 rtm = nlmsg_data(nlh); 3239 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3240 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3241 rtm->rtm_table || rtm->rtm_protocol || 3242 rtm->rtm_scope || rtm->rtm_type) { 3243 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3244 return -EINVAL; 3245 } 3246 3247 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3248 RTM_F_LOOKUP_TABLE | 3249 RTM_F_FIB_MATCH)) { 3250 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3251 return -EINVAL; 3252 } 3253 3254 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3255 rtm_ipv4_policy, extack); 3256 if (err) 3257 return err; 3258 3259 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3260 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3261 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3262 return -EINVAL; 3263 } 3264 3265 for (i = 0; i <= RTA_MAX; i++) { 3266 if (!tb[i]) 3267 continue; 3268 3269 switch (i) { 3270 case RTA_IIF: 3271 case RTA_OIF: 3272 case RTA_SRC: 3273 case RTA_DST: 3274 case RTA_IP_PROTO: 3275 case RTA_SPORT: 3276 case RTA_DPORT: 3277 case RTA_MARK: 3278 case RTA_UID: 3279 break; 3280 default: 3281 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3282 return -EINVAL; 3283 } 3284 } 3285 3286 return 0; 3287 } 3288 3289 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3290 struct netlink_ext_ack *extack) 3291 { 3292 struct net *net = sock_net(in_skb->sk); 3293 struct nlattr *tb[RTA_MAX+1]; 3294 u32 table_id = RT_TABLE_MAIN; 3295 __be16 sport = 0, dport = 0; 3296 struct fib_result res = {}; 3297 u8 ip_proto = IPPROTO_UDP; 3298 struct rtable *rt = NULL; 3299 struct sk_buff *skb; 3300 struct rtmsg *rtm; 3301 struct flowi4 fl4 = {}; 3302 __be32 dst = 0; 3303 __be32 src = 0; 3304 kuid_t uid; 3305 u32 iif; 3306 int err; 3307 int mark; 3308 3309 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3310 if (err < 0) 3311 return err; 3312 3313 rtm = nlmsg_data(nlh); 3314 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3315 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3316 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3317 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3318 if (tb[RTA_UID]) 3319 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3320 else 3321 uid = (iif ? INVALID_UID : current_uid()); 3322 3323 if (tb[RTA_IP_PROTO]) { 3324 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3325 &ip_proto, AF_INET, extack); 3326 if (err) 3327 return err; 3328 } 3329 3330 if (tb[RTA_SPORT]) 3331 sport = nla_get_be16(tb[RTA_SPORT]); 3332 3333 if (tb[RTA_DPORT]) 3334 dport = nla_get_be16(tb[RTA_DPORT]); 3335 3336 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3337 if (!skb) 3338 return -ENOBUFS; 3339 3340 fl4.daddr = dst; 3341 fl4.saddr = src; 3342 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3343 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3344 fl4.flowi4_mark = mark; 3345 fl4.flowi4_uid = uid; 3346 if (sport) 3347 fl4.fl4_sport = sport; 3348 if (dport) 3349 fl4.fl4_dport = dport; 3350 fl4.flowi4_proto = ip_proto; 3351 3352 rcu_read_lock(); 3353 3354 if (iif) { 3355 struct net_device *dev; 3356 3357 dev = dev_get_by_index_rcu(net, iif); 3358 if (!dev) { 3359 err = -ENODEV; 3360 goto errout_rcu; 3361 } 3362 3363 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3364 skb->dev = dev; 3365 skb->mark = mark; 3366 err = ip_route_input_rcu(skb, dst, src, 3367 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3368 &res); 3369 3370 rt = skb_rtable(skb); 3371 if (err == 0 && rt->dst.error) 3372 err = -rt->dst.error; 3373 } else { 3374 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3375 skb->dev = net->loopback_dev; 3376 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3377 err = 0; 3378 if (IS_ERR(rt)) 3379 err = PTR_ERR(rt); 3380 else 3381 skb_dst_set(skb, &rt->dst); 3382 } 3383 3384 if (err) 3385 goto errout_rcu; 3386 3387 if (rtm->rtm_flags & RTM_F_NOTIFY) 3388 rt->rt_flags |= RTCF_NOTIFY; 3389 3390 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3391 table_id = res.table ? res.table->tb_id : 0; 3392 3393 /* reset skb for netlink reply msg */ 3394 skb_trim(skb, 0); 3395 skb_reset_network_header(skb); 3396 skb_reset_transport_header(skb); 3397 skb_reset_mac_header(skb); 3398 3399 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3400 struct fib_rt_info fri; 3401 3402 if (!res.fi) { 3403 err = fib_props[res.type].error; 3404 if (!err) 3405 err = -EHOSTUNREACH; 3406 goto errout_rcu; 3407 } 3408 fri.fi = res.fi; 3409 fri.tb_id = table_id; 3410 fri.dst = res.prefix; 3411 fri.dst_len = res.prefixlen; 3412 fri.dscp = inet_dsfield_to_dscp(fl4.flowi4_tos); 3413 fri.type = rt->rt_type; 3414 fri.offload = 0; 3415 fri.trap = 0; 3416 fri.offload_failed = 0; 3417 if (res.fa_head) { 3418 struct fib_alias *fa; 3419 3420 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3421 u8 slen = 32 - fri.dst_len; 3422 3423 if (fa->fa_slen == slen && 3424 fa->tb_id == fri.tb_id && 3425 fa->fa_dscp == fri.dscp && 3426 fa->fa_info == res.fi && 3427 fa->fa_type == fri.type) { 3428 fri.offload = READ_ONCE(fa->offload); 3429 fri.trap = READ_ONCE(fa->trap); 3430 break; 3431 } 3432 } 3433 } 3434 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3435 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3436 } else { 3437 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3438 NETLINK_CB(in_skb).portid, 3439 nlh->nlmsg_seq, 0); 3440 } 3441 if (err < 0) 3442 goto errout_rcu; 3443 3444 rcu_read_unlock(); 3445 3446 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3447 3448 errout_free: 3449 return err; 3450 errout_rcu: 3451 rcu_read_unlock(); 3452 kfree_skb(skb); 3453 goto errout_free; 3454 } 3455 3456 void ip_rt_multicast_event(struct in_device *in_dev) 3457 { 3458 rt_cache_flush(dev_net(in_dev->dev)); 3459 } 3460 3461 #ifdef CONFIG_SYSCTL 3462 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3463 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3464 static int ip_rt_gc_elasticity __read_mostly = 8; 3465 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3466 3467 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3468 void *buffer, size_t *lenp, loff_t *ppos) 3469 { 3470 struct net *net = (struct net *)__ctl->extra1; 3471 3472 if (write) { 3473 rt_cache_flush(net); 3474 fnhe_genid_bump(net); 3475 return 0; 3476 } 3477 3478 return -EINVAL; 3479 } 3480 3481 static struct ctl_table ipv4_route_table[] = { 3482 { 3483 .procname = "gc_thresh", 3484 .data = &ipv4_dst_ops.gc_thresh, 3485 .maxlen = sizeof(int), 3486 .mode = 0644, 3487 .proc_handler = proc_dointvec, 3488 }, 3489 { 3490 .procname = "max_size", 3491 .data = &ip_rt_max_size, 3492 .maxlen = sizeof(int), 3493 .mode = 0644, 3494 .proc_handler = proc_dointvec, 3495 }, 3496 { 3497 /* Deprecated. Use gc_min_interval_ms */ 3498 3499 .procname = "gc_min_interval", 3500 .data = &ip_rt_gc_min_interval, 3501 .maxlen = sizeof(int), 3502 .mode = 0644, 3503 .proc_handler = proc_dointvec_jiffies, 3504 }, 3505 { 3506 .procname = "gc_min_interval_ms", 3507 .data = &ip_rt_gc_min_interval, 3508 .maxlen = sizeof(int), 3509 .mode = 0644, 3510 .proc_handler = proc_dointvec_ms_jiffies, 3511 }, 3512 { 3513 .procname = "gc_timeout", 3514 .data = &ip_rt_gc_timeout, 3515 .maxlen = sizeof(int), 3516 .mode = 0644, 3517 .proc_handler = proc_dointvec_jiffies, 3518 }, 3519 { 3520 .procname = "gc_interval", 3521 .data = &ip_rt_gc_interval, 3522 .maxlen = sizeof(int), 3523 .mode = 0644, 3524 .proc_handler = proc_dointvec_jiffies, 3525 }, 3526 { 3527 .procname = "redirect_load", 3528 .data = &ip_rt_redirect_load, 3529 .maxlen = sizeof(int), 3530 .mode = 0644, 3531 .proc_handler = proc_dointvec, 3532 }, 3533 { 3534 .procname = "redirect_number", 3535 .data = &ip_rt_redirect_number, 3536 .maxlen = sizeof(int), 3537 .mode = 0644, 3538 .proc_handler = proc_dointvec, 3539 }, 3540 { 3541 .procname = "redirect_silence", 3542 .data = &ip_rt_redirect_silence, 3543 .maxlen = sizeof(int), 3544 .mode = 0644, 3545 .proc_handler = proc_dointvec, 3546 }, 3547 { 3548 .procname = "error_cost", 3549 .data = &ip_rt_error_cost, 3550 .maxlen = sizeof(int), 3551 .mode = 0644, 3552 .proc_handler = proc_dointvec, 3553 }, 3554 { 3555 .procname = "error_burst", 3556 .data = &ip_rt_error_burst, 3557 .maxlen = sizeof(int), 3558 .mode = 0644, 3559 .proc_handler = proc_dointvec, 3560 }, 3561 { 3562 .procname = "gc_elasticity", 3563 .data = &ip_rt_gc_elasticity, 3564 .maxlen = sizeof(int), 3565 .mode = 0644, 3566 .proc_handler = proc_dointvec, 3567 }, 3568 { } 3569 }; 3570 3571 static const char ipv4_route_flush_procname[] = "flush"; 3572 3573 static struct ctl_table ipv4_route_netns_table[] = { 3574 { 3575 .procname = ipv4_route_flush_procname, 3576 .maxlen = sizeof(int), 3577 .mode = 0200, 3578 .proc_handler = ipv4_sysctl_rtcache_flush, 3579 }, 3580 { 3581 .procname = "min_pmtu", 3582 .data = &init_net.ipv4.ip_rt_min_pmtu, 3583 .maxlen = sizeof(int), 3584 .mode = 0644, 3585 .proc_handler = proc_dointvec_minmax, 3586 .extra1 = &ip_min_valid_pmtu, 3587 }, 3588 { 3589 .procname = "mtu_expires", 3590 .data = &init_net.ipv4.ip_rt_mtu_expires, 3591 .maxlen = sizeof(int), 3592 .mode = 0644, 3593 .proc_handler = proc_dointvec_jiffies, 3594 }, 3595 { 3596 .procname = "min_adv_mss", 3597 .data = &init_net.ipv4.ip_rt_min_advmss, 3598 .maxlen = sizeof(int), 3599 .mode = 0644, 3600 .proc_handler = proc_dointvec, 3601 }, 3602 { }, 3603 }; 3604 3605 static __net_init int sysctl_route_net_init(struct net *net) 3606 { 3607 struct ctl_table *tbl; 3608 3609 tbl = ipv4_route_netns_table; 3610 if (!net_eq(net, &init_net)) { 3611 int i; 3612 3613 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3614 if (!tbl) 3615 goto err_dup; 3616 3617 /* Don't export non-whitelisted sysctls to unprivileged users */ 3618 if (net->user_ns != &init_user_ns) { 3619 if (tbl[0].procname != ipv4_route_flush_procname) 3620 tbl[0].procname = NULL; 3621 } 3622 3623 /* Update the variables to point into the current struct net 3624 * except for the first element flush 3625 */ 3626 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3627 tbl[i].data += (void *)net - (void *)&init_net; 3628 } 3629 tbl[0].extra1 = net; 3630 3631 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3632 if (!net->ipv4.route_hdr) 3633 goto err_reg; 3634 return 0; 3635 3636 err_reg: 3637 if (tbl != ipv4_route_netns_table) 3638 kfree(tbl); 3639 err_dup: 3640 return -ENOMEM; 3641 } 3642 3643 static __net_exit void sysctl_route_net_exit(struct net *net) 3644 { 3645 struct ctl_table *tbl; 3646 3647 tbl = net->ipv4.route_hdr->ctl_table_arg; 3648 unregister_net_sysctl_table(net->ipv4.route_hdr); 3649 BUG_ON(tbl == ipv4_route_netns_table); 3650 kfree(tbl); 3651 } 3652 3653 static __net_initdata struct pernet_operations sysctl_route_ops = { 3654 .init = sysctl_route_net_init, 3655 .exit = sysctl_route_net_exit, 3656 }; 3657 #endif 3658 3659 static __net_init int netns_ip_rt_init(struct net *net) 3660 { 3661 /* Set default value for namespaceified sysctls */ 3662 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3663 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3664 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3665 return 0; 3666 } 3667 3668 static struct pernet_operations __net_initdata ip_rt_ops = { 3669 .init = netns_ip_rt_init, 3670 }; 3671 3672 static __net_init int rt_genid_init(struct net *net) 3673 { 3674 atomic_set(&net->ipv4.rt_genid, 0); 3675 atomic_set(&net->fnhe_genid, 0); 3676 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3677 return 0; 3678 } 3679 3680 static __net_initdata struct pernet_operations rt_genid_ops = { 3681 .init = rt_genid_init, 3682 }; 3683 3684 static int __net_init ipv4_inetpeer_init(struct net *net) 3685 { 3686 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3687 3688 if (!bp) 3689 return -ENOMEM; 3690 inet_peer_base_init(bp); 3691 net->ipv4.peers = bp; 3692 return 0; 3693 } 3694 3695 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3696 { 3697 struct inet_peer_base *bp = net->ipv4.peers; 3698 3699 net->ipv4.peers = NULL; 3700 inetpeer_invalidate_tree(bp); 3701 kfree(bp); 3702 } 3703 3704 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3705 .init = ipv4_inetpeer_init, 3706 .exit = ipv4_inetpeer_exit, 3707 }; 3708 3709 #ifdef CONFIG_IP_ROUTE_CLASSID 3710 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3711 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3712 3713 int __init ip_rt_init(void) 3714 { 3715 void *idents_hash; 3716 int cpu; 3717 3718 /* For modern hosts, this will use 2 MB of memory */ 3719 idents_hash = alloc_large_system_hash("IP idents", 3720 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3721 0, 3722 16, /* one bucket per 64 KB */ 3723 HASH_ZERO, 3724 NULL, 3725 &ip_idents_mask, 3726 2048, 3727 256*1024); 3728 3729 ip_idents = idents_hash; 3730 3731 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3732 3733 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3734 3735 for_each_possible_cpu(cpu) { 3736 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3737 3738 INIT_LIST_HEAD(&ul->head); 3739 INIT_LIST_HEAD(&ul->quarantine); 3740 spin_lock_init(&ul->lock); 3741 } 3742 #ifdef CONFIG_IP_ROUTE_CLASSID 3743 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3744 if (!ip_rt_acct) 3745 panic("IP: failed to allocate ip_rt_acct\n"); 3746 #endif 3747 3748 ipv4_dst_ops.kmem_cachep = 3749 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3750 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3751 3752 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3753 3754 if (dst_entries_init(&ipv4_dst_ops) < 0) 3755 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3756 3757 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3758 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3759 3760 ipv4_dst_ops.gc_thresh = ~0; 3761 ip_rt_max_size = INT_MAX; 3762 3763 devinet_init(); 3764 ip_fib_init(); 3765 3766 if (ip_rt_proc_init()) 3767 pr_err("Unable to create route proc files\n"); 3768 #ifdef CONFIG_XFRM 3769 xfrm_init(); 3770 xfrm4_init(); 3771 #endif 3772 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3773 RTNL_FLAG_DOIT_UNLOCKED); 3774 3775 #ifdef CONFIG_SYSCTL 3776 register_pernet_subsys(&sysctl_route_ops); 3777 #endif 3778 register_pernet_subsys(&ip_rt_ops); 3779 register_pernet_subsys(&rt_genid_ops); 3780 register_pernet_subsys(&ipv4_inetpeer_ops); 3781 return 0; 3782 } 3783 3784 #ifdef CONFIG_SYSCTL 3785 /* 3786 * We really need to sanitize the damn ipv4 init order, then all 3787 * this nonsense will go away. 3788 */ 3789 void __init ip_static_sysctl_init(void) 3790 { 3791 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3792 } 3793 #endif 3794