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(); 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(); 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 = get_random_u32_below(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 oif = sk->sk_bound_dev_if; 519 mark = READ_ONCE(sk->sk_mark); 520 tos = ip_sock_rt_tos(sk); 521 scope = ip_sock_rt_scope(sk); 522 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 523 sk->sk_protocol; 524 } 525 526 flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope, 527 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 528 sock_net_uid(net, sk)); 529 } 530 531 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 532 const struct sock *sk) 533 { 534 const struct net *net = dev_net(skb->dev); 535 const struct iphdr *iph = ip_hdr(skb); 536 int oif = skb->dev->ifindex; 537 u8 prot = iph->protocol; 538 u32 mark = skb->mark; 539 __u8 tos = iph->tos; 540 541 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 542 } 543 544 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 545 { 546 const struct inet_sock *inet = inet_sk(sk); 547 const struct ip_options_rcu *inet_opt; 548 __be32 daddr = inet->inet_daddr; 549 550 rcu_read_lock(); 551 inet_opt = rcu_dereference(inet->inet_opt); 552 if (inet_opt && inet_opt->opt.srr) 553 daddr = inet_opt->opt.faddr; 554 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 555 ip_sock_rt_tos(sk) & IPTOS_RT_MASK, 556 ip_sock_rt_scope(sk), 557 inet_test_bit(HDRINCL, sk) ? 558 IPPROTO_RAW : sk->sk_protocol, 559 inet_sk_flowi_flags(sk), 560 daddr, inet->inet_saddr, 0, 0, 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 get_random_u32_below(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 (!(READ_ONCE(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 net_device *dev; 1217 struct ip_options opt; 1218 int res; 1219 1220 /* Recompile ip options since IPCB may not be valid anymore. 1221 * Also check we have a reasonable ipv4 header. 1222 */ 1223 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1224 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1225 return; 1226 1227 memset(&opt, 0, sizeof(opt)); 1228 if (ip_hdr(skb)->ihl > 5) { 1229 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1230 return; 1231 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1232 1233 rcu_read_lock(); 1234 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1235 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); 1236 rcu_read_unlock(); 1237 1238 if (res) 1239 return; 1240 } 1241 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1242 } 1243 1244 static void ipv4_link_failure(struct sk_buff *skb) 1245 { 1246 struct rtable *rt; 1247 1248 ipv4_send_dest_unreach(skb); 1249 1250 rt = skb_rtable(skb); 1251 if (rt) 1252 dst_set_expires(&rt->dst, 0); 1253 } 1254 1255 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1256 { 1257 pr_debug("%s: %pI4 -> %pI4, %s\n", 1258 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1259 skb->dev ? skb->dev->name : "?"); 1260 kfree_skb(skb); 1261 WARN_ON(1); 1262 return 0; 1263 } 1264 1265 /* 1266 * We do not cache source address of outgoing interface, 1267 * because it is used only by IP RR, TS and SRR options, 1268 * so that it out of fast path. 1269 * 1270 * BTW remember: "addr" is allowed to be not aligned 1271 * in IP options! 1272 */ 1273 1274 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1275 { 1276 __be32 src; 1277 1278 if (rt_is_output_route(rt)) 1279 src = ip_hdr(skb)->saddr; 1280 else { 1281 struct fib_result res; 1282 struct iphdr *iph = ip_hdr(skb); 1283 struct flowi4 fl4 = { 1284 .daddr = iph->daddr, 1285 .saddr = iph->saddr, 1286 .flowi4_tos = RT_TOS(iph->tos), 1287 .flowi4_oif = rt->dst.dev->ifindex, 1288 .flowi4_iif = skb->dev->ifindex, 1289 .flowi4_mark = skb->mark, 1290 }; 1291 1292 rcu_read_lock(); 1293 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1294 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1295 else 1296 src = inet_select_addr(rt->dst.dev, 1297 rt_nexthop(rt, iph->daddr), 1298 RT_SCOPE_UNIVERSE); 1299 rcu_read_unlock(); 1300 } 1301 memcpy(addr, &src, 4); 1302 } 1303 1304 #ifdef CONFIG_IP_ROUTE_CLASSID 1305 static void set_class_tag(struct rtable *rt, u32 tag) 1306 { 1307 if (!(rt->dst.tclassid & 0xFFFF)) 1308 rt->dst.tclassid |= tag & 0xFFFF; 1309 if (!(rt->dst.tclassid & 0xFFFF0000)) 1310 rt->dst.tclassid |= tag & 0xFFFF0000; 1311 } 1312 #endif 1313 1314 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1315 { 1316 struct net *net = dev_net(dst->dev); 1317 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1318 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1319 net->ipv4.ip_rt_min_advmss); 1320 1321 return min(advmss, IPV4_MAX_PMTU - header_size); 1322 } 1323 1324 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1325 { 1326 return ip_dst_mtu_maybe_forward(dst, false); 1327 } 1328 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1329 1330 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1331 { 1332 struct fnhe_hash_bucket *hash; 1333 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1334 u32 hval = fnhe_hashfun(daddr); 1335 1336 spin_lock_bh(&fnhe_lock); 1337 1338 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1339 lockdep_is_held(&fnhe_lock)); 1340 hash += hval; 1341 1342 fnhe_p = &hash->chain; 1343 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1344 while (fnhe) { 1345 if (fnhe->fnhe_daddr == daddr) { 1346 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1347 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1348 /* set fnhe_daddr to 0 to ensure it won't bind with 1349 * new dsts in rt_bind_exception(). 1350 */ 1351 fnhe->fnhe_daddr = 0; 1352 fnhe_flush_routes(fnhe); 1353 kfree_rcu(fnhe, rcu); 1354 break; 1355 } 1356 fnhe_p = &fnhe->fnhe_next; 1357 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1358 lockdep_is_held(&fnhe_lock)); 1359 } 1360 1361 spin_unlock_bh(&fnhe_lock); 1362 } 1363 1364 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1365 __be32 daddr) 1366 { 1367 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1368 struct fib_nh_exception *fnhe; 1369 u32 hval; 1370 1371 if (!hash) 1372 return NULL; 1373 1374 hval = fnhe_hashfun(daddr); 1375 1376 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1377 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1378 if (fnhe->fnhe_daddr == daddr) { 1379 if (fnhe->fnhe_expires && 1380 time_after(jiffies, fnhe->fnhe_expires)) { 1381 ip_del_fnhe(nhc, daddr); 1382 break; 1383 } 1384 return fnhe; 1385 } 1386 } 1387 return NULL; 1388 } 1389 1390 /* MTU selection: 1391 * 1. mtu on route is locked - use it 1392 * 2. mtu from nexthop exception 1393 * 3. mtu from egress device 1394 */ 1395 1396 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1397 { 1398 struct fib_nh_common *nhc = res->nhc; 1399 struct net_device *dev = nhc->nhc_dev; 1400 struct fib_info *fi = res->fi; 1401 u32 mtu = 0; 1402 1403 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1404 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1405 mtu = fi->fib_mtu; 1406 1407 if (likely(!mtu)) { 1408 struct fib_nh_exception *fnhe; 1409 1410 fnhe = find_exception(nhc, daddr); 1411 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1412 mtu = fnhe->fnhe_pmtu; 1413 } 1414 1415 if (likely(!mtu)) 1416 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1417 1418 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1419 } 1420 1421 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1422 __be32 daddr, const bool do_cache) 1423 { 1424 bool ret = false; 1425 1426 spin_lock_bh(&fnhe_lock); 1427 1428 if (daddr == fnhe->fnhe_daddr) { 1429 struct rtable __rcu **porig; 1430 struct rtable *orig; 1431 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1432 1433 if (rt_is_input_route(rt)) 1434 porig = &fnhe->fnhe_rth_input; 1435 else 1436 porig = &fnhe->fnhe_rth_output; 1437 orig = rcu_dereference(*porig); 1438 1439 if (fnhe->fnhe_genid != genid) { 1440 fnhe->fnhe_genid = genid; 1441 fnhe->fnhe_gw = 0; 1442 fnhe->fnhe_pmtu = 0; 1443 fnhe->fnhe_expires = 0; 1444 fnhe->fnhe_mtu_locked = false; 1445 fnhe_flush_routes(fnhe); 1446 orig = NULL; 1447 } 1448 fill_route_from_fnhe(rt, fnhe); 1449 if (!rt->rt_gw4) { 1450 rt->rt_gw4 = daddr; 1451 rt->rt_gw_family = AF_INET; 1452 } 1453 1454 if (do_cache) { 1455 dst_hold(&rt->dst); 1456 rcu_assign_pointer(*porig, rt); 1457 if (orig) { 1458 dst_dev_put(&orig->dst); 1459 dst_release(&orig->dst); 1460 } 1461 ret = true; 1462 } 1463 1464 fnhe->fnhe_stamp = jiffies; 1465 } 1466 spin_unlock_bh(&fnhe_lock); 1467 1468 return ret; 1469 } 1470 1471 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1472 { 1473 struct rtable *orig, *prev, **p; 1474 bool ret = true; 1475 1476 if (rt_is_input_route(rt)) { 1477 p = (struct rtable **)&nhc->nhc_rth_input; 1478 } else { 1479 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1480 } 1481 orig = *p; 1482 1483 /* hold dst before doing cmpxchg() to avoid race condition 1484 * on this dst 1485 */ 1486 dst_hold(&rt->dst); 1487 prev = cmpxchg(p, orig, rt); 1488 if (prev == orig) { 1489 if (orig) { 1490 rt_add_uncached_list(orig); 1491 dst_release(&orig->dst); 1492 } 1493 } else { 1494 dst_release(&rt->dst); 1495 ret = false; 1496 } 1497 1498 return ret; 1499 } 1500 1501 struct uncached_list { 1502 spinlock_t lock; 1503 struct list_head head; 1504 struct list_head quarantine; 1505 }; 1506 1507 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1508 1509 void rt_add_uncached_list(struct rtable *rt) 1510 { 1511 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1512 1513 rt->dst.rt_uncached_list = ul; 1514 1515 spin_lock_bh(&ul->lock); 1516 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1517 spin_unlock_bh(&ul->lock); 1518 } 1519 1520 void rt_del_uncached_list(struct rtable *rt) 1521 { 1522 if (!list_empty(&rt->dst.rt_uncached)) { 1523 struct uncached_list *ul = rt->dst.rt_uncached_list; 1524 1525 spin_lock_bh(&ul->lock); 1526 list_del_init(&rt->dst.rt_uncached); 1527 spin_unlock_bh(&ul->lock); 1528 } 1529 } 1530 1531 static void ipv4_dst_destroy(struct dst_entry *dst) 1532 { 1533 struct rtable *rt = (struct rtable *)dst; 1534 1535 ip_dst_metrics_put(dst); 1536 rt_del_uncached_list(rt); 1537 } 1538 1539 void rt_flush_dev(struct net_device *dev) 1540 { 1541 struct rtable *rt, *safe; 1542 int cpu; 1543 1544 for_each_possible_cpu(cpu) { 1545 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1546 1547 if (list_empty(&ul->head)) 1548 continue; 1549 1550 spin_lock_bh(&ul->lock); 1551 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1552 if (rt->dst.dev != dev) 1553 continue; 1554 rt->dst.dev = blackhole_netdev; 1555 netdev_ref_replace(dev, blackhole_netdev, 1556 &rt->dst.dev_tracker, GFP_ATOMIC); 1557 list_move(&rt->dst.rt_uncached, &ul->quarantine); 1558 } 1559 spin_unlock_bh(&ul->lock); 1560 } 1561 } 1562 1563 static bool rt_cache_valid(const struct rtable *rt) 1564 { 1565 return rt && 1566 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1567 !rt_is_expired(rt); 1568 } 1569 1570 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1571 const struct fib_result *res, 1572 struct fib_nh_exception *fnhe, 1573 struct fib_info *fi, u16 type, u32 itag, 1574 const bool do_cache) 1575 { 1576 bool cached = false; 1577 1578 if (fi) { 1579 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1580 1581 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1582 rt->rt_uses_gateway = 1; 1583 rt->rt_gw_family = nhc->nhc_gw_family; 1584 /* only INET and INET6 are supported */ 1585 if (likely(nhc->nhc_gw_family == AF_INET)) 1586 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1587 else 1588 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1589 } 1590 1591 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1592 1593 #ifdef CONFIG_IP_ROUTE_CLASSID 1594 if (nhc->nhc_family == AF_INET) { 1595 struct fib_nh *nh; 1596 1597 nh = container_of(nhc, struct fib_nh, nh_common); 1598 rt->dst.tclassid = nh->nh_tclassid; 1599 } 1600 #endif 1601 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1602 if (unlikely(fnhe)) 1603 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1604 else if (do_cache) 1605 cached = rt_cache_route(nhc, rt); 1606 if (unlikely(!cached)) { 1607 /* Routes we intend to cache in nexthop exception or 1608 * FIB nexthop have the DST_NOCACHE bit clear. 1609 * However, if we are unsuccessful at storing this 1610 * route into the cache we really need to set it. 1611 */ 1612 if (!rt->rt_gw4) { 1613 rt->rt_gw_family = AF_INET; 1614 rt->rt_gw4 = daddr; 1615 } 1616 rt_add_uncached_list(rt); 1617 } 1618 } else 1619 rt_add_uncached_list(rt); 1620 1621 #ifdef CONFIG_IP_ROUTE_CLASSID 1622 #ifdef CONFIG_IP_MULTIPLE_TABLES 1623 set_class_tag(rt, res->tclassid); 1624 #endif 1625 set_class_tag(rt, itag); 1626 #endif 1627 } 1628 1629 struct rtable *rt_dst_alloc(struct net_device *dev, 1630 unsigned int flags, u16 type, 1631 bool noxfrm) 1632 { 1633 struct rtable *rt; 1634 1635 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 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 1650 rt->dst.output = ip_output; 1651 if (flags & RTCF_LOCAL) 1652 rt->dst.input = ip_local_deliver; 1653 } 1654 1655 return rt; 1656 } 1657 EXPORT_SYMBOL(rt_dst_alloc); 1658 1659 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1660 { 1661 struct rtable *new_rt; 1662 1663 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1664 rt->dst.flags); 1665 1666 if (new_rt) { 1667 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1668 new_rt->rt_flags = rt->rt_flags; 1669 new_rt->rt_type = rt->rt_type; 1670 new_rt->rt_is_input = rt->rt_is_input; 1671 new_rt->rt_iif = rt->rt_iif; 1672 new_rt->rt_pmtu = rt->rt_pmtu; 1673 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1674 new_rt->rt_gw_family = rt->rt_gw_family; 1675 if (rt->rt_gw_family == AF_INET) 1676 new_rt->rt_gw4 = rt->rt_gw4; 1677 else if (rt->rt_gw_family == AF_INET6) 1678 new_rt->rt_gw6 = rt->rt_gw6; 1679 1680 new_rt->dst.input = rt->dst.input; 1681 new_rt->dst.output = rt->dst.output; 1682 new_rt->dst.error = rt->dst.error; 1683 new_rt->dst.lastuse = jiffies; 1684 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1685 } 1686 return new_rt; 1687 } 1688 EXPORT_SYMBOL(rt_dst_clone); 1689 1690 /* called in rcu_read_lock() section */ 1691 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1692 u8 tos, struct net_device *dev, 1693 struct in_device *in_dev, u32 *itag) 1694 { 1695 int err; 1696 1697 /* Primary sanity checks. */ 1698 if (!in_dev) 1699 return -EINVAL; 1700 1701 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1702 skb->protocol != htons(ETH_P_IP)) 1703 return -EINVAL; 1704 1705 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1706 return -EINVAL; 1707 1708 if (ipv4_is_zeronet(saddr)) { 1709 if (!ipv4_is_local_multicast(daddr) && 1710 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1711 return -EINVAL; 1712 } else { 1713 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1714 in_dev, itag); 1715 if (err < 0) 1716 return err; 1717 } 1718 return 0; 1719 } 1720 1721 /* called in rcu_read_lock() section */ 1722 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1723 u8 tos, struct net_device *dev, int our) 1724 { 1725 struct in_device *in_dev = __in_dev_get_rcu(dev); 1726 unsigned int flags = RTCF_MULTICAST; 1727 struct rtable *rth; 1728 u32 itag = 0; 1729 int err; 1730 1731 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1732 if (err) 1733 return err; 1734 1735 if (our) 1736 flags |= RTCF_LOCAL; 1737 1738 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1739 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1740 1741 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1742 false); 1743 if (!rth) 1744 return -ENOBUFS; 1745 1746 #ifdef CONFIG_IP_ROUTE_CLASSID 1747 rth->dst.tclassid = itag; 1748 #endif 1749 rth->dst.output = ip_rt_bug; 1750 rth->rt_is_input= 1; 1751 1752 #ifdef CONFIG_IP_MROUTE 1753 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1754 rth->dst.input = ip_mr_input; 1755 #endif 1756 RT_CACHE_STAT_INC(in_slow_mc); 1757 1758 skb_dst_drop(skb); 1759 skb_dst_set(skb, &rth->dst); 1760 return 0; 1761 } 1762 1763 1764 static void ip_handle_martian_source(struct net_device *dev, 1765 struct in_device *in_dev, 1766 struct sk_buff *skb, 1767 __be32 daddr, 1768 __be32 saddr) 1769 { 1770 RT_CACHE_STAT_INC(in_martian_src); 1771 #ifdef CONFIG_IP_ROUTE_VERBOSE 1772 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1773 /* 1774 * RFC1812 recommendation, if source is martian, 1775 * the only hint is MAC header. 1776 */ 1777 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1778 &daddr, &saddr, dev->name); 1779 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1780 print_hex_dump(KERN_WARNING, "ll header: ", 1781 DUMP_PREFIX_OFFSET, 16, 1, 1782 skb_mac_header(skb), 1783 dev->hard_header_len, false); 1784 } 1785 } 1786 #endif 1787 } 1788 1789 /* called in rcu_read_lock() section */ 1790 static int __mkroute_input(struct sk_buff *skb, 1791 const struct fib_result *res, 1792 struct in_device *in_dev, 1793 __be32 daddr, __be32 saddr, u32 tos) 1794 { 1795 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1796 struct net_device *dev = nhc->nhc_dev; 1797 struct fib_nh_exception *fnhe; 1798 struct rtable *rth; 1799 int err; 1800 struct in_device *out_dev; 1801 bool do_cache; 1802 u32 itag = 0; 1803 1804 /* get a working reference to the output device */ 1805 out_dev = __in_dev_get_rcu(dev); 1806 if (!out_dev) { 1807 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1808 return -EINVAL; 1809 } 1810 1811 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1812 in_dev->dev, in_dev, &itag); 1813 if (err < 0) { 1814 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1815 saddr); 1816 1817 goto cleanup; 1818 } 1819 1820 do_cache = res->fi && !itag; 1821 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1822 skb->protocol == htons(ETH_P_IP)) { 1823 __be32 gw; 1824 1825 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1826 if (IN_DEV_SHARED_MEDIA(out_dev) || 1827 inet_addr_onlink(out_dev, saddr, gw)) 1828 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1829 } 1830 1831 if (skb->protocol != htons(ETH_P_IP)) { 1832 /* Not IP (i.e. ARP). Do not create route, if it is 1833 * invalid for proxy arp. DNAT routes are always valid. 1834 * 1835 * Proxy arp feature have been extended to allow, ARP 1836 * replies back to the same interface, to support 1837 * Private VLAN switch technologies. See arp.c. 1838 */ 1839 if (out_dev == in_dev && 1840 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1841 err = -EINVAL; 1842 goto cleanup; 1843 } 1844 } 1845 1846 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1847 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1848 1849 fnhe = find_exception(nhc, daddr); 1850 if (do_cache) { 1851 if (fnhe) 1852 rth = rcu_dereference(fnhe->fnhe_rth_input); 1853 else 1854 rth = rcu_dereference(nhc->nhc_rth_input); 1855 if (rt_cache_valid(rth)) { 1856 skb_dst_set_noref(skb, &rth->dst); 1857 goto out; 1858 } 1859 } 1860 1861 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1862 IN_DEV_ORCONF(out_dev, NOXFRM)); 1863 if (!rth) { 1864 err = -ENOBUFS; 1865 goto cleanup; 1866 } 1867 1868 rth->rt_is_input = 1; 1869 RT_CACHE_STAT_INC(in_slow_tot); 1870 1871 rth->dst.input = ip_forward; 1872 1873 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1874 do_cache); 1875 lwtunnel_set_redirect(&rth->dst); 1876 skb_dst_set(skb, &rth->dst); 1877 out: 1878 err = 0; 1879 cleanup: 1880 return err; 1881 } 1882 1883 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1884 /* To make ICMP packets follow the right flow, the multipath hash is 1885 * calculated from the inner IP addresses. 1886 */ 1887 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1888 struct flow_keys *hash_keys) 1889 { 1890 const struct iphdr *outer_iph = ip_hdr(skb); 1891 const struct iphdr *key_iph = outer_iph; 1892 const struct iphdr *inner_iph; 1893 const struct icmphdr *icmph; 1894 struct iphdr _inner_iph; 1895 struct icmphdr _icmph; 1896 1897 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1898 goto out; 1899 1900 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1901 goto out; 1902 1903 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1904 &_icmph); 1905 if (!icmph) 1906 goto out; 1907 1908 if (!icmp_is_err(icmph->type)) 1909 goto out; 1910 1911 inner_iph = skb_header_pointer(skb, 1912 outer_iph->ihl * 4 + sizeof(_icmph), 1913 sizeof(_inner_iph), &_inner_iph); 1914 if (!inner_iph) 1915 goto out; 1916 1917 key_iph = inner_iph; 1918 out: 1919 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1920 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1921 } 1922 1923 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1924 const struct sk_buff *skb, 1925 bool *p_has_inner) 1926 { 1927 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1928 struct flow_keys keys, hash_keys; 1929 1930 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1931 return 0; 1932 1933 memset(&hash_keys, 0, sizeof(hash_keys)); 1934 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1935 1936 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1937 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1938 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1939 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1940 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1941 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1942 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1943 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1944 hash_keys.ports.src = keys.ports.src; 1945 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1946 hash_keys.ports.dst = keys.ports.dst; 1947 1948 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1949 return flow_hash_from_keys(&hash_keys); 1950 } 1951 1952 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1953 const struct sk_buff *skb, 1954 bool has_inner) 1955 { 1956 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1957 struct flow_keys keys, hash_keys; 1958 1959 /* We assume the packet carries an encapsulation, but if none was 1960 * encountered during dissection of the outer flow, then there is no 1961 * point in calling the flow dissector again. 1962 */ 1963 if (!has_inner) 1964 return 0; 1965 1966 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1967 return 0; 1968 1969 memset(&hash_keys, 0, sizeof(hash_keys)); 1970 skb_flow_dissect_flow_keys(skb, &keys, 0); 1971 1972 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1973 return 0; 1974 1975 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1976 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1977 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1978 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1979 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1980 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1981 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1982 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1983 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1984 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1985 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1986 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1988 hash_keys.tags.flow_label = keys.tags.flow_label; 1989 } 1990 1991 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1992 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1993 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1994 hash_keys.ports.src = keys.ports.src; 1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1996 hash_keys.ports.dst = keys.ports.dst; 1997 1998 return flow_hash_from_keys(&hash_keys); 1999 } 2000 2001 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2002 const struct sk_buff *skb) 2003 { 2004 u32 mhash, mhash_inner; 2005 bool has_inner = true; 2006 2007 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2008 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2009 2010 return jhash_2words(mhash, mhash_inner, 0); 2011 } 2012 2013 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2014 const struct flowi4 *fl4) 2015 { 2016 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2017 struct flow_keys hash_keys; 2018 2019 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2020 return 0; 2021 2022 memset(&hash_keys, 0, sizeof(hash_keys)); 2023 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2024 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2025 hash_keys.addrs.v4addrs.src = fl4->saddr; 2026 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2027 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2028 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2029 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2030 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2031 hash_keys.ports.src = fl4->fl4_sport; 2032 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2033 hash_keys.ports.dst = fl4->fl4_dport; 2034 2035 return flow_hash_from_keys(&hash_keys); 2036 } 2037 2038 /* if skb is set it will be used and fl4 can be NULL */ 2039 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2040 const struct sk_buff *skb, struct flow_keys *flkeys) 2041 { 2042 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2043 struct flow_keys hash_keys; 2044 u32 mhash = 0; 2045 2046 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2047 case 0: 2048 memset(&hash_keys, 0, sizeof(hash_keys)); 2049 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2050 if (skb) { 2051 ip_multipath_l3_keys(skb, &hash_keys); 2052 } else { 2053 hash_keys.addrs.v4addrs.src = fl4->saddr; 2054 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2055 } 2056 mhash = flow_hash_from_keys(&hash_keys); 2057 break; 2058 case 1: 2059 /* skb is currently provided only when forwarding */ 2060 if (skb) { 2061 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2062 struct flow_keys keys; 2063 2064 /* short-circuit if we already have L4 hash present */ 2065 if (skb->l4_hash) 2066 return skb_get_hash_raw(skb) >> 1; 2067 2068 memset(&hash_keys, 0, sizeof(hash_keys)); 2069 2070 if (!flkeys) { 2071 skb_flow_dissect_flow_keys(skb, &keys, flag); 2072 flkeys = &keys; 2073 } 2074 2075 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2076 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2077 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2078 hash_keys.ports.src = flkeys->ports.src; 2079 hash_keys.ports.dst = flkeys->ports.dst; 2080 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2081 } else { 2082 memset(&hash_keys, 0, sizeof(hash_keys)); 2083 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2084 hash_keys.addrs.v4addrs.src = fl4->saddr; 2085 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2086 hash_keys.ports.src = fl4->fl4_sport; 2087 hash_keys.ports.dst = fl4->fl4_dport; 2088 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2089 } 2090 mhash = flow_hash_from_keys(&hash_keys); 2091 break; 2092 case 2: 2093 memset(&hash_keys, 0, sizeof(hash_keys)); 2094 /* skb is currently provided only when forwarding */ 2095 if (skb) { 2096 struct flow_keys keys; 2097 2098 skb_flow_dissect_flow_keys(skb, &keys, 0); 2099 /* Inner can be v4 or v6 */ 2100 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2101 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2102 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2103 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2104 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2105 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2106 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2107 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2108 hash_keys.tags.flow_label = keys.tags.flow_label; 2109 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2110 } else { 2111 /* Same as case 0 */ 2112 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2113 ip_multipath_l3_keys(skb, &hash_keys); 2114 } 2115 } else { 2116 /* Same as case 0 */ 2117 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2118 hash_keys.addrs.v4addrs.src = fl4->saddr; 2119 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2120 } 2121 mhash = flow_hash_from_keys(&hash_keys); 2122 break; 2123 case 3: 2124 if (skb) 2125 mhash = fib_multipath_custom_hash_skb(net, skb); 2126 else 2127 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2128 break; 2129 } 2130 2131 if (multipath_hash) 2132 mhash = jhash_2words(mhash, multipath_hash, 0); 2133 2134 return mhash >> 1; 2135 } 2136 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2137 2138 static int ip_mkroute_input(struct sk_buff *skb, 2139 struct fib_result *res, 2140 struct in_device *in_dev, 2141 __be32 daddr, __be32 saddr, u32 tos, 2142 struct flow_keys *hkeys) 2143 { 2144 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2145 if (res->fi && fib_info_num_path(res->fi) > 1) { 2146 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2147 2148 fib_select_multipath(res, h); 2149 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2150 } 2151 #endif 2152 2153 /* create a routing cache entry */ 2154 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2155 } 2156 2157 /* Implements all the saddr-related checks as ip_route_input_slow(), 2158 * assuming daddr is valid and the destination is not a local broadcast one. 2159 * Uses the provided hint instead of performing a route lookup. 2160 */ 2161 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2162 u8 tos, struct net_device *dev, 2163 const struct sk_buff *hint) 2164 { 2165 struct in_device *in_dev = __in_dev_get_rcu(dev); 2166 struct rtable *rt = skb_rtable(hint); 2167 struct net *net = dev_net(dev); 2168 int err = -EINVAL; 2169 u32 tag = 0; 2170 2171 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2172 goto martian_source; 2173 2174 if (ipv4_is_zeronet(saddr)) 2175 goto martian_source; 2176 2177 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2178 goto martian_source; 2179 2180 if (rt->rt_type != RTN_LOCAL) 2181 goto skip_validate_source; 2182 2183 tos &= IPTOS_RT_MASK; 2184 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2185 if (err < 0) 2186 goto martian_source; 2187 2188 skip_validate_source: 2189 skb_dst_copy(skb, hint); 2190 return 0; 2191 2192 martian_source: 2193 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2194 return err; 2195 } 2196 2197 /* get device for dst_alloc with local routes */ 2198 static struct net_device *ip_rt_get_dev(struct net *net, 2199 const struct fib_result *res) 2200 { 2201 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2202 struct net_device *dev = NULL; 2203 2204 if (nhc) 2205 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2206 2207 return dev ? : net->loopback_dev; 2208 } 2209 2210 /* 2211 * NOTE. We drop all the packets that has local source 2212 * addresses, because every properly looped back packet 2213 * must have correct destination already attached by output routine. 2214 * Changes in the enforced policies must be applied also to 2215 * ip_route_use_hint(). 2216 * 2217 * Such approach solves two big problems: 2218 * 1. Not simplex devices are handled properly. 2219 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2220 * called with rcu_read_lock() 2221 */ 2222 2223 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2224 u8 tos, struct net_device *dev, 2225 struct fib_result *res) 2226 { 2227 struct in_device *in_dev = __in_dev_get_rcu(dev); 2228 struct flow_keys *flkeys = NULL, _flkeys; 2229 struct net *net = dev_net(dev); 2230 struct ip_tunnel_info *tun_info; 2231 int err = -EINVAL; 2232 unsigned int flags = 0; 2233 u32 itag = 0; 2234 struct rtable *rth; 2235 struct flowi4 fl4; 2236 bool do_cache = true; 2237 2238 /* IP on this device is disabled. */ 2239 2240 if (!in_dev) 2241 goto out; 2242 2243 /* Check for the most weird martians, which can be not detected 2244 * by fib_lookup. 2245 */ 2246 2247 tun_info = skb_tunnel_info(skb); 2248 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2249 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2250 else 2251 fl4.flowi4_tun_key.tun_id = 0; 2252 skb_dst_drop(skb); 2253 2254 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2255 goto martian_source; 2256 2257 res->fi = NULL; 2258 res->table = NULL; 2259 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2260 goto brd_input; 2261 2262 /* Accept zero addresses only to limited broadcast; 2263 * I even do not know to fix it or not. Waiting for complains :-) 2264 */ 2265 if (ipv4_is_zeronet(saddr)) 2266 goto martian_source; 2267 2268 if (ipv4_is_zeronet(daddr)) 2269 goto martian_destination; 2270 2271 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2272 * and call it once if daddr or/and saddr are loopback addresses 2273 */ 2274 if (ipv4_is_loopback(daddr)) { 2275 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2276 goto martian_destination; 2277 } else if (ipv4_is_loopback(saddr)) { 2278 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2279 goto martian_source; 2280 } 2281 2282 /* 2283 * Now we are ready to route packet. 2284 */ 2285 fl4.flowi4_l3mdev = 0; 2286 fl4.flowi4_oif = 0; 2287 fl4.flowi4_iif = dev->ifindex; 2288 fl4.flowi4_mark = skb->mark; 2289 fl4.flowi4_tos = tos; 2290 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2291 fl4.flowi4_flags = 0; 2292 fl4.daddr = daddr; 2293 fl4.saddr = saddr; 2294 fl4.flowi4_uid = sock_net_uid(net, NULL); 2295 fl4.flowi4_multipath_hash = 0; 2296 2297 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2298 flkeys = &_flkeys; 2299 } else { 2300 fl4.flowi4_proto = 0; 2301 fl4.fl4_sport = 0; 2302 fl4.fl4_dport = 0; 2303 } 2304 2305 err = fib_lookup(net, &fl4, res, 0); 2306 if (err != 0) { 2307 if (!IN_DEV_FORWARD(in_dev)) 2308 err = -EHOSTUNREACH; 2309 goto no_route; 2310 } 2311 2312 if (res->type == RTN_BROADCAST) { 2313 if (IN_DEV_BFORWARD(in_dev)) 2314 goto make_route; 2315 /* not do cache if bc_forwarding is enabled */ 2316 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2317 do_cache = false; 2318 goto brd_input; 2319 } 2320 2321 if (res->type == RTN_LOCAL) { 2322 err = fib_validate_source(skb, saddr, daddr, tos, 2323 0, dev, in_dev, &itag); 2324 if (err < 0) 2325 goto martian_source; 2326 goto local_input; 2327 } 2328 2329 if (!IN_DEV_FORWARD(in_dev)) { 2330 err = -EHOSTUNREACH; 2331 goto no_route; 2332 } 2333 if (res->type != RTN_UNICAST) 2334 goto martian_destination; 2335 2336 make_route: 2337 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2338 out: return err; 2339 2340 brd_input: 2341 if (skb->protocol != htons(ETH_P_IP)) 2342 goto e_inval; 2343 2344 if (!ipv4_is_zeronet(saddr)) { 2345 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2346 in_dev, &itag); 2347 if (err < 0) 2348 goto martian_source; 2349 } 2350 flags |= RTCF_BROADCAST; 2351 res->type = RTN_BROADCAST; 2352 RT_CACHE_STAT_INC(in_brd); 2353 2354 local_input: 2355 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2356 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2357 2358 do_cache &= res->fi && !itag; 2359 if (do_cache) { 2360 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2361 2362 rth = rcu_dereference(nhc->nhc_rth_input); 2363 if (rt_cache_valid(rth)) { 2364 skb_dst_set_noref(skb, &rth->dst); 2365 err = 0; 2366 goto out; 2367 } 2368 } 2369 2370 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2371 flags | RTCF_LOCAL, res->type, false); 2372 if (!rth) 2373 goto e_nobufs; 2374 2375 rth->dst.output= ip_rt_bug; 2376 #ifdef CONFIG_IP_ROUTE_CLASSID 2377 rth->dst.tclassid = itag; 2378 #endif 2379 rth->rt_is_input = 1; 2380 2381 RT_CACHE_STAT_INC(in_slow_tot); 2382 if (res->type == RTN_UNREACHABLE) { 2383 rth->dst.input= ip_error; 2384 rth->dst.error= -err; 2385 rth->rt_flags &= ~RTCF_LOCAL; 2386 } 2387 2388 if (do_cache) { 2389 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2390 2391 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2392 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2393 WARN_ON(rth->dst.input == lwtunnel_input); 2394 rth->dst.lwtstate->orig_input = rth->dst.input; 2395 rth->dst.input = lwtunnel_input; 2396 } 2397 2398 if (unlikely(!rt_cache_route(nhc, rth))) 2399 rt_add_uncached_list(rth); 2400 } 2401 skb_dst_set(skb, &rth->dst); 2402 err = 0; 2403 goto out; 2404 2405 no_route: 2406 RT_CACHE_STAT_INC(in_no_route); 2407 res->type = RTN_UNREACHABLE; 2408 res->fi = NULL; 2409 res->table = NULL; 2410 goto local_input; 2411 2412 /* 2413 * Do not cache martian addresses: they should be logged (RFC1812) 2414 */ 2415 martian_destination: 2416 RT_CACHE_STAT_INC(in_martian_dst); 2417 #ifdef CONFIG_IP_ROUTE_VERBOSE 2418 if (IN_DEV_LOG_MARTIANS(in_dev)) 2419 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2420 &daddr, &saddr, dev->name); 2421 #endif 2422 2423 e_inval: 2424 err = -EINVAL; 2425 goto out; 2426 2427 e_nobufs: 2428 err = -ENOBUFS; 2429 goto out; 2430 2431 martian_source: 2432 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2433 goto out; 2434 } 2435 2436 /* called with rcu_read_lock held */ 2437 static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2438 u8 tos, struct net_device *dev, struct fib_result *res) 2439 { 2440 /* Multicast recognition logic is moved from route cache to here. 2441 * The problem was that too many Ethernet cards have broken/missing 2442 * hardware multicast filters :-( As result the host on multicasting 2443 * network acquires a lot of useless route cache entries, sort of 2444 * SDR messages from all the world. Now we try to get rid of them. 2445 * Really, provided software IP multicast filter is organized 2446 * reasonably (at least, hashed), it does not result in a slowdown 2447 * comparing with route cache reject entries. 2448 * Note, that multicast routers are not affected, because 2449 * route cache entry is created eventually. 2450 */ 2451 if (ipv4_is_multicast(daddr)) { 2452 struct in_device *in_dev = __in_dev_get_rcu(dev); 2453 int our = 0; 2454 int err = -EINVAL; 2455 2456 if (!in_dev) 2457 return err; 2458 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2459 ip_hdr(skb)->protocol); 2460 2461 /* check l3 master if no match yet */ 2462 if (!our && netif_is_l3_slave(dev)) { 2463 struct in_device *l3_in_dev; 2464 2465 l3_in_dev = __in_dev_get_rcu(skb->dev); 2466 if (l3_in_dev) 2467 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2468 ip_hdr(skb)->protocol); 2469 } 2470 2471 if (our 2472 #ifdef CONFIG_IP_MROUTE 2473 || 2474 (!ipv4_is_local_multicast(daddr) && 2475 IN_DEV_MFORWARD(in_dev)) 2476 #endif 2477 ) { 2478 err = ip_route_input_mc(skb, daddr, saddr, 2479 tos, dev, our); 2480 } 2481 return err; 2482 } 2483 2484 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2485 } 2486 2487 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2488 u8 tos, struct net_device *dev) 2489 { 2490 struct fib_result res; 2491 int err; 2492 2493 tos &= IPTOS_RT_MASK; 2494 rcu_read_lock(); 2495 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2496 rcu_read_unlock(); 2497 2498 return err; 2499 } 2500 EXPORT_SYMBOL(ip_route_input_noref); 2501 2502 /* called with rcu_read_lock() */ 2503 static struct rtable *__mkroute_output(const struct fib_result *res, 2504 const struct flowi4 *fl4, int orig_oif, 2505 struct net_device *dev_out, 2506 unsigned int flags) 2507 { 2508 struct fib_info *fi = res->fi; 2509 struct fib_nh_exception *fnhe; 2510 struct in_device *in_dev; 2511 u16 type = res->type; 2512 struct rtable *rth; 2513 bool do_cache; 2514 2515 in_dev = __in_dev_get_rcu(dev_out); 2516 if (!in_dev) 2517 return ERR_PTR(-EINVAL); 2518 2519 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2520 if (ipv4_is_loopback(fl4->saddr) && 2521 !(dev_out->flags & IFF_LOOPBACK) && 2522 !netif_is_l3_master(dev_out)) 2523 return ERR_PTR(-EINVAL); 2524 2525 if (ipv4_is_lbcast(fl4->daddr)) 2526 type = RTN_BROADCAST; 2527 else if (ipv4_is_multicast(fl4->daddr)) 2528 type = RTN_MULTICAST; 2529 else if (ipv4_is_zeronet(fl4->daddr)) 2530 return ERR_PTR(-EINVAL); 2531 2532 if (dev_out->flags & IFF_LOOPBACK) 2533 flags |= RTCF_LOCAL; 2534 2535 do_cache = true; 2536 if (type == RTN_BROADCAST) { 2537 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2538 fi = NULL; 2539 } else if (type == RTN_MULTICAST) { 2540 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2541 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2542 fl4->flowi4_proto)) 2543 flags &= ~RTCF_LOCAL; 2544 else 2545 do_cache = false; 2546 /* If multicast route do not exist use 2547 * default one, but do not gateway in this case. 2548 * Yes, it is hack. 2549 */ 2550 if (fi && res->prefixlen < 4) 2551 fi = NULL; 2552 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2553 (orig_oif != dev_out->ifindex)) { 2554 /* For local routes that require a particular output interface 2555 * we do not want to cache the result. Caching the result 2556 * causes incorrect behaviour when there are multiple source 2557 * addresses on the interface, the end result being that if the 2558 * intended recipient is waiting on that interface for the 2559 * packet he won't receive it because it will be delivered on 2560 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2561 * be set to the loopback interface as well. 2562 */ 2563 do_cache = false; 2564 } 2565 2566 fnhe = NULL; 2567 do_cache &= fi != NULL; 2568 if (fi) { 2569 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2570 struct rtable __rcu **prth; 2571 2572 fnhe = find_exception(nhc, fl4->daddr); 2573 if (!do_cache) 2574 goto add; 2575 if (fnhe) { 2576 prth = &fnhe->fnhe_rth_output; 2577 } else { 2578 if (unlikely(fl4->flowi4_flags & 2579 FLOWI_FLAG_KNOWN_NH && 2580 !(nhc->nhc_gw_family && 2581 nhc->nhc_scope == RT_SCOPE_LINK))) { 2582 do_cache = false; 2583 goto add; 2584 } 2585 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2586 } 2587 rth = rcu_dereference(*prth); 2588 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2589 return rth; 2590 } 2591 2592 add: 2593 rth = rt_dst_alloc(dev_out, flags, type, 2594 IN_DEV_ORCONF(in_dev, NOXFRM)); 2595 if (!rth) 2596 return ERR_PTR(-ENOBUFS); 2597 2598 rth->rt_iif = orig_oif; 2599 2600 RT_CACHE_STAT_INC(out_slow_tot); 2601 2602 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2603 if (flags & RTCF_LOCAL && 2604 !(dev_out->flags & IFF_LOOPBACK)) { 2605 rth->dst.output = ip_mc_output; 2606 RT_CACHE_STAT_INC(out_slow_mc); 2607 } 2608 #ifdef CONFIG_IP_MROUTE 2609 if (type == RTN_MULTICAST) { 2610 if (IN_DEV_MFORWARD(in_dev) && 2611 !ipv4_is_local_multicast(fl4->daddr)) { 2612 rth->dst.input = ip_mr_input; 2613 rth->dst.output = ip_mc_output; 2614 } 2615 } 2616 #endif 2617 } 2618 2619 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2620 lwtunnel_set_redirect(&rth->dst); 2621 2622 return rth; 2623 } 2624 2625 /* 2626 * Major route resolver routine. 2627 */ 2628 2629 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2630 const struct sk_buff *skb) 2631 { 2632 struct fib_result res = { 2633 .type = RTN_UNSPEC, 2634 .fi = NULL, 2635 .table = NULL, 2636 .tclassid = 0, 2637 }; 2638 struct rtable *rth; 2639 2640 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2641 ip_rt_fix_tos(fl4); 2642 2643 rcu_read_lock(); 2644 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2645 rcu_read_unlock(); 2646 2647 return rth; 2648 } 2649 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2650 2651 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2652 struct fib_result *res, 2653 const struct sk_buff *skb) 2654 { 2655 struct net_device *dev_out = NULL; 2656 int orig_oif = fl4->flowi4_oif; 2657 unsigned int flags = 0; 2658 struct rtable *rth; 2659 int err; 2660 2661 if (fl4->saddr) { 2662 if (ipv4_is_multicast(fl4->saddr) || 2663 ipv4_is_lbcast(fl4->saddr) || 2664 ipv4_is_zeronet(fl4->saddr)) { 2665 rth = ERR_PTR(-EINVAL); 2666 goto out; 2667 } 2668 2669 rth = ERR_PTR(-ENETUNREACH); 2670 2671 /* I removed check for oif == dev_out->oif here. 2672 * It was wrong for two reasons: 2673 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2674 * is assigned to multiple interfaces. 2675 * 2. Moreover, we are allowed to send packets with saddr 2676 * of another iface. --ANK 2677 */ 2678 2679 if (fl4->flowi4_oif == 0 && 2680 (ipv4_is_multicast(fl4->daddr) || 2681 ipv4_is_lbcast(fl4->daddr))) { 2682 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2683 dev_out = __ip_dev_find(net, fl4->saddr, false); 2684 if (!dev_out) 2685 goto out; 2686 2687 /* Special hack: user can direct multicasts 2688 * and limited broadcast via necessary interface 2689 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2690 * This hack is not just for fun, it allows 2691 * vic,vat and friends to work. 2692 * They bind socket to loopback, set ttl to zero 2693 * and expect that it will work. 2694 * From the viewpoint of routing cache they are broken, 2695 * because we are not allowed to build multicast path 2696 * with loopback source addr (look, routing cache 2697 * cannot know, that ttl is zero, so that packet 2698 * will not leave this host and route is valid). 2699 * Luckily, this hack is good workaround. 2700 */ 2701 2702 fl4->flowi4_oif = dev_out->ifindex; 2703 goto make_route; 2704 } 2705 2706 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2707 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2708 if (!__ip_dev_find(net, fl4->saddr, false)) 2709 goto out; 2710 } 2711 } 2712 2713 2714 if (fl4->flowi4_oif) { 2715 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2716 rth = ERR_PTR(-ENODEV); 2717 if (!dev_out) 2718 goto out; 2719 2720 /* RACE: Check return value of inet_select_addr instead. */ 2721 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2722 rth = ERR_PTR(-ENETUNREACH); 2723 goto out; 2724 } 2725 if (ipv4_is_local_multicast(fl4->daddr) || 2726 ipv4_is_lbcast(fl4->daddr) || 2727 fl4->flowi4_proto == IPPROTO_IGMP) { 2728 if (!fl4->saddr) 2729 fl4->saddr = inet_select_addr(dev_out, 0, 2730 RT_SCOPE_LINK); 2731 goto make_route; 2732 } 2733 if (!fl4->saddr) { 2734 if (ipv4_is_multicast(fl4->daddr)) 2735 fl4->saddr = inet_select_addr(dev_out, 0, 2736 fl4->flowi4_scope); 2737 else if (!fl4->daddr) 2738 fl4->saddr = inet_select_addr(dev_out, 0, 2739 RT_SCOPE_HOST); 2740 } 2741 } 2742 2743 if (!fl4->daddr) { 2744 fl4->daddr = fl4->saddr; 2745 if (!fl4->daddr) 2746 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2747 dev_out = net->loopback_dev; 2748 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2749 res->type = RTN_LOCAL; 2750 flags |= RTCF_LOCAL; 2751 goto make_route; 2752 } 2753 2754 err = fib_lookup(net, fl4, res, 0); 2755 if (err) { 2756 res->fi = NULL; 2757 res->table = NULL; 2758 if (fl4->flowi4_oif && 2759 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2760 /* Apparently, routing tables are wrong. Assume, 2761 * that the destination is on link. 2762 * 2763 * WHY? DW. 2764 * Because we are allowed to send to iface 2765 * even if it has NO routes and NO assigned 2766 * addresses. When oif is specified, routing 2767 * tables are looked up with only one purpose: 2768 * to catch if destination is gatewayed, rather than 2769 * direct. Moreover, if MSG_DONTROUTE is set, 2770 * we send packet, ignoring both routing tables 2771 * and ifaddr state. --ANK 2772 * 2773 * 2774 * We could make it even if oif is unknown, 2775 * likely IPv6, but we do not. 2776 */ 2777 2778 if (fl4->saddr == 0) 2779 fl4->saddr = inet_select_addr(dev_out, 0, 2780 RT_SCOPE_LINK); 2781 res->type = RTN_UNICAST; 2782 goto make_route; 2783 } 2784 rth = ERR_PTR(err); 2785 goto out; 2786 } 2787 2788 if (res->type == RTN_LOCAL) { 2789 if (!fl4->saddr) { 2790 if (res->fi->fib_prefsrc) 2791 fl4->saddr = res->fi->fib_prefsrc; 2792 else 2793 fl4->saddr = fl4->daddr; 2794 } 2795 2796 /* L3 master device is the loopback for that domain */ 2797 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2798 net->loopback_dev; 2799 2800 /* make sure orig_oif points to fib result device even 2801 * though packet rx/tx happens over loopback or l3mdev 2802 */ 2803 orig_oif = FIB_RES_OIF(*res); 2804 2805 fl4->flowi4_oif = dev_out->ifindex; 2806 flags |= RTCF_LOCAL; 2807 goto make_route; 2808 } 2809 2810 fib_select_path(net, res, fl4, skb); 2811 2812 dev_out = FIB_RES_DEV(*res); 2813 2814 make_route: 2815 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2816 2817 out: 2818 return rth; 2819 } 2820 2821 static struct dst_ops ipv4_dst_blackhole_ops = { 2822 .family = AF_INET, 2823 .default_advmss = ipv4_default_advmss, 2824 .neigh_lookup = ipv4_neigh_lookup, 2825 .check = dst_blackhole_check, 2826 .cow_metrics = dst_blackhole_cow_metrics, 2827 .update_pmtu = dst_blackhole_update_pmtu, 2828 .redirect = dst_blackhole_redirect, 2829 .mtu = dst_blackhole_mtu, 2830 }; 2831 2832 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2833 { 2834 struct rtable *ort = (struct rtable *) dst_orig; 2835 struct rtable *rt; 2836 2837 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2838 if (rt) { 2839 struct dst_entry *new = &rt->dst; 2840 2841 new->__use = 1; 2842 new->input = dst_discard; 2843 new->output = dst_discard_out; 2844 2845 new->dev = net->loopback_dev; 2846 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2847 2848 rt->rt_is_input = ort->rt_is_input; 2849 rt->rt_iif = ort->rt_iif; 2850 rt->rt_pmtu = ort->rt_pmtu; 2851 rt->rt_mtu_locked = ort->rt_mtu_locked; 2852 2853 rt->rt_genid = rt_genid_ipv4(net); 2854 rt->rt_flags = ort->rt_flags; 2855 rt->rt_type = ort->rt_type; 2856 rt->rt_uses_gateway = ort->rt_uses_gateway; 2857 rt->rt_gw_family = ort->rt_gw_family; 2858 if (rt->rt_gw_family == AF_INET) 2859 rt->rt_gw4 = ort->rt_gw4; 2860 else if (rt->rt_gw_family == AF_INET6) 2861 rt->rt_gw6 = ort->rt_gw6; 2862 } 2863 2864 dst_release(dst_orig); 2865 2866 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2867 } 2868 2869 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2870 const struct sock *sk) 2871 { 2872 struct rtable *rt = __ip_route_output_key(net, flp4); 2873 2874 if (IS_ERR(rt)) 2875 return rt; 2876 2877 if (flp4->flowi4_proto) { 2878 flp4->flowi4_oif = rt->dst.dev->ifindex; 2879 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2880 flowi4_to_flowi(flp4), 2881 sk, 0); 2882 } 2883 2884 return rt; 2885 } 2886 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2887 2888 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2889 struct net_device *dev, 2890 struct net *net, __be32 *saddr, 2891 const struct ip_tunnel_info *info, 2892 u8 protocol, bool use_cache) 2893 { 2894 #ifdef CONFIG_DST_CACHE 2895 struct dst_cache *dst_cache; 2896 #endif 2897 struct rtable *rt = NULL; 2898 struct flowi4 fl4; 2899 __u8 tos; 2900 2901 #ifdef CONFIG_DST_CACHE 2902 dst_cache = (struct dst_cache *)&info->dst_cache; 2903 if (use_cache) { 2904 rt = dst_cache_get_ip4(dst_cache, saddr); 2905 if (rt) 2906 return rt; 2907 } 2908 #endif 2909 memset(&fl4, 0, sizeof(fl4)); 2910 fl4.flowi4_mark = skb->mark; 2911 fl4.flowi4_proto = protocol; 2912 fl4.daddr = info->key.u.ipv4.dst; 2913 fl4.saddr = info->key.u.ipv4.src; 2914 tos = info->key.tos; 2915 fl4.flowi4_tos = RT_TOS(tos); 2916 2917 rt = ip_route_output_key(net, &fl4); 2918 if (IS_ERR(rt)) { 2919 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2920 return ERR_PTR(-ENETUNREACH); 2921 } 2922 if (rt->dst.dev == dev) { /* is this necessary? */ 2923 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2924 ip_rt_put(rt); 2925 return ERR_PTR(-ELOOP); 2926 } 2927 #ifdef CONFIG_DST_CACHE 2928 if (use_cache) 2929 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2930 #endif 2931 *saddr = fl4.saddr; 2932 return rt; 2933 } 2934 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2935 2936 /* called with rcu_read_lock held */ 2937 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2938 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2939 struct sk_buff *skb, u32 portid, u32 seq, 2940 unsigned int flags) 2941 { 2942 struct rtmsg *r; 2943 struct nlmsghdr *nlh; 2944 unsigned long expires = 0; 2945 u32 error; 2946 u32 metrics[RTAX_MAX]; 2947 2948 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2949 if (!nlh) 2950 return -EMSGSIZE; 2951 2952 r = nlmsg_data(nlh); 2953 r->rtm_family = AF_INET; 2954 r->rtm_dst_len = 32; 2955 r->rtm_src_len = 0; 2956 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2957 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2958 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2959 goto nla_put_failure; 2960 r->rtm_type = rt->rt_type; 2961 r->rtm_scope = RT_SCOPE_UNIVERSE; 2962 r->rtm_protocol = RTPROT_UNSPEC; 2963 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2964 if (rt->rt_flags & RTCF_NOTIFY) 2965 r->rtm_flags |= RTM_F_NOTIFY; 2966 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2967 r->rtm_flags |= RTCF_DOREDIRECT; 2968 2969 if (nla_put_in_addr(skb, RTA_DST, dst)) 2970 goto nla_put_failure; 2971 if (src) { 2972 r->rtm_src_len = 32; 2973 if (nla_put_in_addr(skb, RTA_SRC, src)) 2974 goto nla_put_failure; 2975 } 2976 if (rt->dst.dev && 2977 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2978 goto nla_put_failure; 2979 if (rt->dst.lwtstate && 2980 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2981 goto nla_put_failure; 2982 #ifdef CONFIG_IP_ROUTE_CLASSID 2983 if (rt->dst.tclassid && 2984 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2985 goto nla_put_failure; 2986 #endif 2987 if (fl4 && !rt_is_input_route(rt) && 2988 fl4->saddr != src) { 2989 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2990 goto nla_put_failure; 2991 } 2992 if (rt->rt_uses_gateway) { 2993 if (rt->rt_gw_family == AF_INET && 2994 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2995 goto nla_put_failure; 2996 } else if (rt->rt_gw_family == AF_INET6) { 2997 int alen = sizeof(struct in6_addr); 2998 struct nlattr *nla; 2999 struct rtvia *via; 3000 3001 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3002 if (!nla) 3003 goto nla_put_failure; 3004 3005 via = nla_data(nla); 3006 via->rtvia_family = AF_INET6; 3007 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3008 } 3009 } 3010 3011 expires = rt->dst.expires; 3012 if (expires) { 3013 unsigned long now = jiffies; 3014 3015 if (time_before(now, expires)) 3016 expires -= now; 3017 else 3018 expires = 0; 3019 } 3020 3021 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3022 if (rt->rt_pmtu && expires) 3023 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3024 if (rt->rt_mtu_locked && expires) 3025 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3026 if (rtnetlink_put_metrics(skb, metrics) < 0) 3027 goto nla_put_failure; 3028 3029 if (fl4) { 3030 if (fl4->flowi4_mark && 3031 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3032 goto nla_put_failure; 3033 3034 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3035 nla_put_u32(skb, RTA_UID, 3036 from_kuid_munged(current_user_ns(), 3037 fl4->flowi4_uid))) 3038 goto nla_put_failure; 3039 3040 if (rt_is_input_route(rt)) { 3041 #ifdef CONFIG_IP_MROUTE 3042 if (ipv4_is_multicast(dst) && 3043 !ipv4_is_local_multicast(dst) && 3044 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3045 int err = ipmr_get_route(net, skb, 3046 fl4->saddr, fl4->daddr, 3047 r, portid); 3048 3049 if (err <= 0) { 3050 if (err == 0) 3051 return 0; 3052 goto nla_put_failure; 3053 } 3054 } else 3055 #endif 3056 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3057 goto nla_put_failure; 3058 } 3059 } 3060 3061 error = rt->dst.error; 3062 3063 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3064 goto nla_put_failure; 3065 3066 nlmsg_end(skb, nlh); 3067 return 0; 3068 3069 nla_put_failure: 3070 nlmsg_cancel(skb, nlh); 3071 return -EMSGSIZE; 3072 } 3073 3074 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3075 struct netlink_callback *cb, u32 table_id, 3076 struct fnhe_hash_bucket *bucket, int genid, 3077 int *fa_index, int fa_start, unsigned int flags) 3078 { 3079 int i; 3080 3081 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3082 struct fib_nh_exception *fnhe; 3083 3084 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3085 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3086 struct rtable *rt; 3087 int err; 3088 3089 if (*fa_index < fa_start) 3090 goto next; 3091 3092 if (fnhe->fnhe_genid != genid) 3093 goto next; 3094 3095 if (fnhe->fnhe_expires && 3096 time_after(jiffies, fnhe->fnhe_expires)) 3097 goto next; 3098 3099 rt = rcu_dereference(fnhe->fnhe_rth_input); 3100 if (!rt) 3101 rt = rcu_dereference(fnhe->fnhe_rth_output); 3102 if (!rt) 3103 goto next; 3104 3105 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3106 table_id, NULL, skb, 3107 NETLINK_CB(cb->skb).portid, 3108 cb->nlh->nlmsg_seq, flags); 3109 if (err) 3110 return err; 3111 next: 3112 (*fa_index)++; 3113 } 3114 } 3115 3116 return 0; 3117 } 3118 3119 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3120 u32 table_id, struct fib_info *fi, 3121 int *fa_index, int fa_start, unsigned int flags) 3122 { 3123 struct net *net = sock_net(cb->skb->sk); 3124 int nhsel, genid = fnhe_genid(net); 3125 3126 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3127 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3128 struct fnhe_hash_bucket *bucket; 3129 int err; 3130 3131 if (nhc->nhc_flags & RTNH_F_DEAD) 3132 continue; 3133 3134 rcu_read_lock(); 3135 bucket = rcu_dereference(nhc->nhc_exceptions); 3136 err = 0; 3137 if (bucket) 3138 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3139 genid, fa_index, fa_start, 3140 flags); 3141 rcu_read_unlock(); 3142 if (err) 3143 return err; 3144 } 3145 3146 return 0; 3147 } 3148 3149 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3150 u8 ip_proto, __be16 sport, 3151 __be16 dport) 3152 { 3153 struct sk_buff *skb; 3154 struct iphdr *iph; 3155 3156 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3157 if (!skb) 3158 return NULL; 3159 3160 /* Reserve room for dummy headers, this skb can pass 3161 * through good chunk of routing engine. 3162 */ 3163 skb_reset_mac_header(skb); 3164 skb_reset_network_header(skb); 3165 skb->protocol = htons(ETH_P_IP); 3166 iph = skb_put(skb, sizeof(struct iphdr)); 3167 iph->protocol = ip_proto; 3168 iph->saddr = src; 3169 iph->daddr = dst; 3170 iph->version = 0x4; 3171 iph->frag_off = 0; 3172 iph->ihl = 0x5; 3173 skb_set_transport_header(skb, skb->len); 3174 3175 switch (iph->protocol) { 3176 case IPPROTO_UDP: { 3177 struct udphdr *udph; 3178 3179 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3180 udph->source = sport; 3181 udph->dest = dport; 3182 udph->len = htons(sizeof(struct udphdr)); 3183 udph->check = 0; 3184 break; 3185 } 3186 case IPPROTO_TCP: { 3187 struct tcphdr *tcph; 3188 3189 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3190 tcph->source = sport; 3191 tcph->dest = dport; 3192 tcph->doff = sizeof(struct tcphdr) / 4; 3193 tcph->rst = 1; 3194 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3195 src, dst, 0); 3196 break; 3197 } 3198 case IPPROTO_ICMP: { 3199 struct icmphdr *icmph; 3200 3201 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3202 icmph->type = ICMP_ECHO; 3203 icmph->code = 0; 3204 } 3205 } 3206 3207 return skb; 3208 } 3209 3210 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3211 const struct nlmsghdr *nlh, 3212 struct nlattr **tb, 3213 struct netlink_ext_ack *extack) 3214 { 3215 struct rtmsg *rtm; 3216 int i, err; 3217 3218 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3219 NL_SET_ERR_MSG(extack, 3220 "ipv4: Invalid header for route get request"); 3221 return -EINVAL; 3222 } 3223 3224 if (!netlink_strict_get_check(skb)) 3225 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3226 rtm_ipv4_policy, extack); 3227 3228 rtm = nlmsg_data(nlh); 3229 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3230 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3231 rtm->rtm_table || rtm->rtm_protocol || 3232 rtm->rtm_scope || rtm->rtm_type) { 3233 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3234 return -EINVAL; 3235 } 3236 3237 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3238 RTM_F_LOOKUP_TABLE | 3239 RTM_F_FIB_MATCH)) { 3240 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3241 return -EINVAL; 3242 } 3243 3244 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3245 rtm_ipv4_policy, extack); 3246 if (err) 3247 return err; 3248 3249 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3250 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3251 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3252 return -EINVAL; 3253 } 3254 3255 for (i = 0; i <= RTA_MAX; i++) { 3256 if (!tb[i]) 3257 continue; 3258 3259 switch (i) { 3260 case RTA_IIF: 3261 case RTA_OIF: 3262 case RTA_SRC: 3263 case RTA_DST: 3264 case RTA_IP_PROTO: 3265 case RTA_SPORT: 3266 case RTA_DPORT: 3267 case RTA_MARK: 3268 case RTA_UID: 3269 break; 3270 default: 3271 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3272 return -EINVAL; 3273 } 3274 } 3275 3276 return 0; 3277 } 3278 3279 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3280 struct netlink_ext_ack *extack) 3281 { 3282 struct net *net = sock_net(in_skb->sk); 3283 struct nlattr *tb[RTA_MAX+1]; 3284 u32 table_id = RT_TABLE_MAIN; 3285 __be16 sport = 0, dport = 0; 3286 struct fib_result res = {}; 3287 u8 ip_proto = IPPROTO_UDP; 3288 struct rtable *rt = NULL; 3289 struct sk_buff *skb; 3290 struct rtmsg *rtm; 3291 struct flowi4 fl4 = {}; 3292 __be32 dst = 0; 3293 __be32 src = 0; 3294 kuid_t uid; 3295 u32 iif; 3296 int err; 3297 int mark; 3298 3299 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3300 if (err < 0) 3301 return err; 3302 3303 rtm = nlmsg_data(nlh); 3304 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3305 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3306 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3307 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3308 if (tb[RTA_UID]) 3309 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3310 else 3311 uid = (iif ? INVALID_UID : current_uid()); 3312 3313 if (tb[RTA_IP_PROTO]) { 3314 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3315 &ip_proto, AF_INET, extack); 3316 if (err) 3317 return err; 3318 } 3319 3320 if (tb[RTA_SPORT]) 3321 sport = nla_get_be16(tb[RTA_SPORT]); 3322 3323 if (tb[RTA_DPORT]) 3324 dport = nla_get_be16(tb[RTA_DPORT]); 3325 3326 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3327 if (!skb) 3328 return -ENOBUFS; 3329 3330 fl4.daddr = dst; 3331 fl4.saddr = src; 3332 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3333 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3334 fl4.flowi4_mark = mark; 3335 fl4.flowi4_uid = uid; 3336 if (sport) 3337 fl4.fl4_sport = sport; 3338 if (dport) 3339 fl4.fl4_dport = dport; 3340 fl4.flowi4_proto = ip_proto; 3341 3342 rcu_read_lock(); 3343 3344 if (iif) { 3345 struct net_device *dev; 3346 3347 dev = dev_get_by_index_rcu(net, iif); 3348 if (!dev) { 3349 err = -ENODEV; 3350 goto errout_rcu; 3351 } 3352 3353 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3354 skb->dev = dev; 3355 skb->mark = mark; 3356 err = ip_route_input_rcu(skb, dst, src, 3357 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3358 &res); 3359 3360 rt = skb_rtable(skb); 3361 if (err == 0 && rt->dst.error) 3362 err = -rt->dst.error; 3363 } else { 3364 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3365 skb->dev = net->loopback_dev; 3366 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3367 err = 0; 3368 if (IS_ERR(rt)) 3369 err = PTR_ERR(rt); 3370 else 3371 skb_dst_set(skb, &rt->dst); 3372 } 3373 3374 if (err) 3375 goto errout_rcu; 3376 3377 if (rtm->rtm_flags & RTM_F_NOTIFY) 3378 rt->rt_flags |= RTCF_NOTIFY; 3379 3380 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3381 table_id = res.table ? res.table->tb_id : 0; 3382 3383 /* reset skb for netlink reply msg */ 3384 skb_trim(skb, 0); 3385 skb_reset_network_header(skb); 3386 skb_reset_transport_header(skb); 3387 skb_reset_mac_header(skb); 3388 3389 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3390 struct fib_rt_info fri; 3391 3392 if (!res.fi) { 3393 err = fib_props[res.type].error; 3394 if (!err) 3395 err = -EHOSTUNREACH; 3396 goto errout_rcu; 3397 } 3398 fri.fi = res.fi; 3399 fri.tb_id = table_id; 3400 fri.dst = res.prefix; 3401 fri.dst_len = res.prefixlen; 3402 fri.dscp = inet_dsfield_to_dscp(fl4.flowi4_tos); 3403 fri.type = rt->rt_type; 3404 fri.offload = 0; 3405 fri.trap = 0; 3406 fri.offload_failed = 0; 3407 if (res.fa_head) { 3408 struct fib_alias *fa; 3409 3410 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3411 u8 slen = 32 - fri.dst_len; 3412 3413 if (fa->fa_slen == slen && 3414 fa->tb_id == fri.tb_id && 3415 fa->fa_dscp == fri.dscp && 3416 fa->fa_info == res.fi && 3417 fa->fa_type == fri.type) { 3418 fri.offload = READ_ONCE(fa->offload); 3419 fri.trap = READ_ONCE(fa->trap); 3420 fri.offload_failed = 3421 READ_ONCE(fa->offload_failed); 3422 break; 3423 } 3424 } 3425 } 3426 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3427 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3428 } else { 3429 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3430 NETLINK_CB(in_skb).portid, 3431 nlh->nlmsg_seq, 0); 3432 } 3433 if (err < 0) 3434 goto errout_rcu; 3435 3436 rcu_read_unlock(); 3437 3438 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3439 3440 errout_free: 3441 return err; 3442 errout_rcu: 3443 rcu_read_unlock(); 3444 kfree_skb(skb); 3445 goto errout_free; 3446 } 3447 3448 void ip_rt_multicast_event(struct in_device *in_dev) 3449 { 3450 rt_cache_flush(dev_net(in_dev->dev)); 3451 } 3452 3453 #ifdef CONFIG_SYSCTL 3454 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3455 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3456 static int ip_rt_gc_elasticity __read_mostly = 8; 3457 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3458 3459 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3460 void *buffer, size_t *lenp, loff_t *ppos) 3461 { 3462 struct net *net = (struct net *)__ctl->extra1; 3463 3464 if (write) { 3465 rt_cache_flush(net); 3466 fnhe_genid_bump(net); 3467 return 0; 3468 } 3469 3470 return -EINVAL; 3471 } 3472 3473 static struct ctl_table ipv4_route_table[] = { 3474 { 3475 .procname = "gc_thresh", 3476 .data = &ipv4_dst_ops.gc_thresh, 3477 .maxlen = sizeof(int), 3478 .mode = 0644, 3479 .proc_handler = proc_dointvec, 3480 }, 3481 { 3482 .procname = "max_size", 3483 .data = &ip_rt_max_size, 3484 .maxlen = sizeof(int), 3485 .mode = 0644, 3486 .proc_handler = proc_dointvec, 3487 }, 3488 { 3489 /* Deprecated. Use gc_min_interval_ms */ 3490 3491 .procname = "gc_min_interval", 3492 .data = &ip_rt_gc_min_interval, 3493 .maxlen = sizeof(int), 3494 .mode = 0644, 3495 .proc_handler = proc_dointvec_jiffies, 3496 }, 3497 { 3498 .procname = "gc_min_interval_ms", 3499 .data = &ip_rt_gc_min_interval, 3500 .maxlen = sizeof(int), 3501 .mode = 0644, 3502 .proc_handler = proc_dointvec_ms_jiffies, 3503 }, 3504 { 3505 .procname = "gc_timeout", 3506 .data = &ip_rt_gc_timeout, 3507 .maxlen = sizeof(int), 3508 .mode = 0644, 3509 .proc_handler = proc_dointvec_jiffies, 3510 }, 3511 { 3512 .procname = "gc_interval", 3513 .data = &ip_rt_gc_interval, 3514 .maxlen = sizeof(int), 3515 .mode = 0644, 3516 .proc_handler = proc_dointvec_jiffies, 3517 }, 3518 { 3519 .procname = "redirect_load", 3520 .data = &ip_rt_redirect_load, 3521 .maxlen = sizeof(int), 3522 .mode = 0644, 3523 .proc_handler = proc_dointvec, 3524 }, 3525 { 3526 .procname = "redirect_number", 3527 .data = &ip_rt_redirect_number, 3528 .maxlen = sizeof(int), 3529 .mode = 0644, 3530 .proc_handler = proc_dointvec, 3531 }, 3532 { 3533 .procname = "redirect_silence", 3534 .data = &ip_rt_redirect_silence, 3535 .maxlen = sizeof(int), 3536 .mode = 0644, 3537 .proc_handler = proc_dointvec, 3538 }, 3539 { 3540 .procname = "error_cost", 3541 .data = &ip_rt_error_cost, 3542 .maxlen = sizeof(int), 3543 .mode = 0644, 3544 .proc_handler = proc_dointvec, 3545 }, 3546 { 3547 .procname = "error_burst", 3548 .data = &ip_rt_error_burst, 3549 .maxlen = sizeof(int), 3550 .mode = 0644, 3551 .proc_handler = proc_dointvec, 3552 }, 3553 { 3554 .procname = "gc_elasticity", 3555 .data = &ip_rt_gc_elasticity, 3556 .maxlen = sizeof(int), 3557 .mode = 0644, 3558 .proc_handler = proc_dointvec, 3559 }, 3560 { } 3561 }; 3562 3563 static const char ipv4_route_flush_procname[] = "flush"; 3564 3565 static struct ctl_table ipv4_route_netns_table[] = { 3566 { 3567 .procname = ipv4_route_flush_procname, 3568 .maxlen = sizeof(int), 3569 .mode = 0200, 3570 .proc_handler = ipv4_sysctl_rtcache_flush, 3571 }, 3572 { 3573 .procname = "min_pmtu", 3574 .data = &init_net.ipv4.ip_rt_min_pmtu, 3575 .maxlen = sizeof(int), 3576 .mode = 0644, 3577 .proc_handler = proc_dointvec_minmax, 3578 .extra1 = &ip_min_valid_pmtu, 3579 }, 3580 { 3581 .procname = "mtu_expires", 3582 .data = &init_net.ipv4.ip_rt_mtu_expires, 3583 .maxlen = sizeof(int), 3584 .mode = 0644, 3585 .proc_handler = proc_dointvec_jiffies, 3586 }, 3587 { 3588 .procname = "min_adv_mss", 3589 .data = &init_net.ipv4.ip_rt_min_advmss, 3590 .maxlen = sizeof(int), 3591 .mode = 0644, 3592 .proc_handler = proc_dointvec, 3593 }, 3594 { }, 3595 }; 3596 3597 static __net_init int sysctl_route_net_init(struct net *net) 3598 { 3599 struct ctl_table *tbl; 3600 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3601 3602 tbl = ipv4_route_netns_table; 3603 if (!net_eq(net, &init_net)) { 3604 int i; 3605 3606 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3607 if (!tbl) 3608 goto err_dup; 3609 3610 /* Don't export non-whitelisted sysctls to unprivileged users */ 3611 if (net->user_ns != &init_user_ns) { 3612 if (tbl[0].procname != ipv4_route_flush_procname) { 3613 tbl[0].procname = NULL; 3614 table_size = 0; 3615 } 3616 } 3617 3618 /* Update the variables to point into the current struct net 3619 * except for the first element flush 3620 */ 3621 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++) 3622 tbl[i].data += (void *)net - (void *)&init_net; 3623 } 3624 tbl[0].extra1 = net; 3625 3626 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3627 tbl, table_size); 3628 if (!net->ipv4.route_hdr) 3629 goto err_reg; 3630 return 0; 3631 3632 err_reg: 3633 if (tbl != ipv4_route_netns_table) 3634 kfree(tbl); 3635 err_dup: 3636 return -ENOMEM; 3637 } 3638 3639 static __net_exit void sysctl_route_net_exit(struct net *net) 3640 { 3641 struct ctl_table *tbl; 3642 3643 tbl = net->ipv4.route_hdr->ctl_table_arg; 3644 unregister_net_sysctl_table(net->ipv4.route_hdr); 3645 BUG_ON(tbl == ipv4_route_netns_table); 3646 kfree(tbl); 3647 } 3648 3649 static __net_initdata struct pernet_operations sysctl_route_ops = { 3650 .init = sysctl_route_net_init, 3651 .exit = sysctl_route_net_exit, 3652 }; 3653 #endif 3654 3655 static __net_init int netns_ip_rt_init(struct net *net) 3656 { 3657 /* Set default value for namespaceified sysctls */ 3658 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3659 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3660 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3661 return 0; 3662 } 3663 3664 static struct pernet_operations __net_initdata ip_rt_ops = { 3665 .init = netns_ip_rt_init, 3666 }; 3667 3668 static __net_init int rt_genid_init(struct net *net) 3669 { 3670 atomic_set(&net->ipv4.rt_genid, 0); 3671 atomic_set(&net->fnhe_genid, 0); 3672 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3673 return 0; 3674 } 3675 3676 static __net_initdata struct pernet_operations rt_genid_ops = { 3677 .init = rt_genid_init, 3678 }; 3679 3680 static int __net_init ipv4_inetpeer_init(struct net *net) 3681 { 3682 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3683 3684 if (!bp) 3685 return -ENOMEM; 3686 inet_peer_base_init(bp); 3687 net->ipv4.peers = bp; 3688 return 0; 3689 } 3690 3691 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3692 { 3693 struct inet_peer_base *bp = net->ipv4.peers; 3694 3695 net->ipv4.peers = NULL; 3696 inetpeer_invalidate_tree(bp); 3697 kfree(bp); 3698 } 3699 3700 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3701 .init = ipv4_inetpeer_init, 3702 .exit = ipv4_inetpeer_exit, 3703 }; 3704 3705 #ifdef CONFIG_IP_ROUTE_CLASSID 3706 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3707 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3708 3709 int __init ip_rt_init(void) 3710 { 3711 void *idents_hash; 3712 int cpu; 3713 3714 /* For modern hosts, this will use 2 MB of memory */ 3715 idents_hash = alloc_large_system_hash("IP idents", 3716 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3717 0, 3718 16, /* one bucket per 64 KB */ 3719 HASH_ZERO, 3720 NULL, 3721 &ip_idents_mask, 3722 2048, 3723 256*1024); 3724 3725 ip_idents = idents_hash; 3726 3727 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3728 3729 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3730 3731 for_each_possible_cpu(cpu) { 3732 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3733 3734 INIT_LIST_HEAD(&ul->head); 3735 INIT_LIST_HEAD(&ul->quarantine); 3736 spin_lock_init(&ul->lock); 3737 } 3738 #ifdef CONFIG_IP_ROUTE_CLASSID 3739 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3740 if (!ip_rt_acct) 3741 panic("IP: failed to allocate ip_rt_acct\n"); 3742 #endif 3743 3744 ipv4_dst_ops.kmem_cachep = 3745 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3746 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3747 3748 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3749 3750 if (dst_entries_init(&ipv4_dst_ops) < 0) 3751 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3752 3753 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3754 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3755 3756 ipv4_dst_ops.gc_thresh = ~0; 3757 ip_rt_max_size = INT_MAX; 3758 3759 devinet_init(); 3760 ip_fib_init(); 3761 3762 if (ip_rt_proc_init()) 3763 pr_err("Unable to create route proc files\n"); 3764 #ifdef CONFIG_XFRM 3765 xfrm_init(); 3766 xfrm4_init(); 3767 #endif 3768 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3769 RTNL_FLAG_DOIT_UNLOCKED); 3770 3771 #ifdef CONFIG_SYSCTL 3772 register_pernet_subsys(&sysctl_route_ops); 3773 #endif 3774 register_pernet_subsys(&ip_rt_ops); 3775 register_pernet_subsys(&rt_genid_ops); 3776 register_pernet_subsys(&ipv4_inetpeer_ops); 3777 return 0; 3778 } 3779 3780 #ifdef CONFIG_SYSCTL 3781 /* 3782 * We really need to sanitize the damn ipv4 init order, then all 3783 * this nonsense will go away. 3784 */ 3785 void __init ip_static_sysctl_init(void) 3786 { 3787 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3788 } 3789 #endif 3790