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/flow.h> 88 #include <net/inet_dscp.h> 89 #include <net/net_namespace.h> 90 #include <net/ip.h> 91 #include <net/route.h> 92 #include <net/inetpeer.h> 93 #include <net/sock.h> 94 #include <net/ip_fib.h> 95 #include <net/nexthop.h> 96 #include <net/tcp.h> 97 #include <net/icmp.h> 98 #include <net/xfrm.h> 99 #include <net/lwtunnel.h> 100 #include <net/netevent.h> 101 #include <net/rtnetlink.h> 102 #ifdef CONFIG_SYSCTL 103 #include <linux/sysctl.h> 104 #endif 105 #include <net/secure_seq.h> 106 #include <net/ip_tunnels.h> 107 108 #include "fib_lookup.h" 109 110 #define RT_GC_TIMEOUT (300*HZ) 111 112 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 113 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 114 #define DEFAULT_MIN_ADVMSS 256 115 static int ip_rt_max_size; 116 static int ip_rt_redirect_number __read_mostly = 9; 117 static int ip_rt_redirect_load __read_mostly = HZ / 50; 118 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 119 static int ip_rt_error_cost __read_mostly = HZ; 120 static int ip_rt_error_burst __read_mostly = 5 * HZ; 121 122 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 123 124 /* 125 * Interface to generic destination cache. 126 */ 127 128 INDIRECT_CALLABLE_SCOPE 129 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 130 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 131 INDIRECT_CALLABLE_SCOPE 132 unsigned int ipv4_mtu(const struct dst_entry *dst); 133 static void ipv4_negative_advice(struct sock *sk, 134 struct dst_entry *dst); 135 static void ipv4_link_failure(struct sk_buff *skb); 136 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 137 struct sk_buff *skb, u32 mtu, 138 bool confirm_neigh); 139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 140 struct sk_buff *skb); 141 static void ipv4_dst_destroy(struct dst_entry *dst); 142 143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 144 { 145 WARN_ON(1); 146 return NULL; 147 } 148 149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 150 struct sk_buff *skb, 151 const void *daddr); 152 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 153 154 static struct dst_ops ipv4_dst_ops = { 155 .family = AF_INET, 156 .check = ipv4_dst_check, 157 .default_advmss = ipv4_default_advmss, 158 .mtu = ipv4_mtu, 159 .cow_metrics = ipv4_cow_metrics, 160 .destroy = ipv4_dst_destroy, 161 .negative_advice = ipv4_negative_advice, 162 .link_failure = ipv4_link_failure, 163 .update_pmtu = ip_rt_update_pmtu, 164 .redirect = ip_do_redirect, 165 .local_out = __ip_local_out, 166 .neigh_lookup = ipv4_neigh_lookup, 167 .confirm_neigh = ipv4_confirm_neigh, 168 }; 169 170 #define ECN_OR_COST(class) TC_PRIO_##class 171 172 const __u8 ip_tos2prio[16] = { 173 TC_PRIO_BESTEFFORT, 174 ECN_OR_COST(BESTEFFORT), 175 TC_PRIO_BESTEFFORT, 176 ECN_OR_COST(BESTEFFORT), 177 TC_PRIO_BULK, 178 ECN_OR_COST(BULK), 179 TC_PRIO_BULK, 180 ECN_OR_COST(BULK), 181 TC_PRIO_INTERACTIVE, 182 ECN_OR_COST(INTERACTIVE), 183 TC_PRIO_INTERACTIVE, 184 ECN_OR_COST(INTERACTIVE), 185 TC_PRIO_INTERACTIVE_BULK, 186 ECN_OR_COST(INTERACTIVE_BULK), 187 TC_PRIO_INTERACTIVE_BULK, 188 ECN_OR_COST(INTERACTIVE_BULK) 189 }; 190 EXPORT_SYMBOL(ip_tos2prio); 191 192 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 193 #ifndef CONFIG_PREEMPT_RT 194 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195 #else 196 #define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) 197 #endif 198 199 #ifdef CONFIG_PROC_FS 200 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 201 { 202 if (*pos) 203 return NULL; 204 return SEQ_START_TOKEN; 205 } 206 207 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 208 { 209 ++*pos; 210 return NULL; 211 } 212 213 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 214 { 215 } 216 217 static int rt_cache_seq_show(struct seq_file *seq, void *v) 218 { 219 if (v == SEQ_START_TOKEN) 220 seq_printf(seq, "%-127s\n", 221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 223 "HHUptod\tSpecDst"); 224 return 0; 225 } 226 227 static const struct seq_operations rt_cache_seq_ops = { 228 .start = rt_cache_seq_start, 229 .next = rt_cache_seq_next, 230 .stop = rt_cache_seq_stop, 231 .show = rt_cache_seq_show, 232 }; 233 234 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 235 { 236 int cpu; 237 238 if (*pos == 0) 239 return SEQ_START_TOKEN; 240 241 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 242 if (!cpu_possible(cpu)) 243 continue; 244 *pos = cpu+1; 245 return &per_cpu(rt_cache_stat, cpu); 246 } 247 return NULL; 248 } 249 250 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 251 { 252 int cpu; 253 254 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 255 if (!cpu_possible(cpu)) 256 continue; 257 *pos = cpu+1; 258 return &per_cpu(rt_cache_stat, cpu); 259 } 260 (*pos)++; 261 return NULL; 262 263 } 264 265 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 266 { 267 268 } 269 270 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 271 { 272 struct rt_cache_stat *st = v; 273 274 if (v == SEQ_START_TOKEN) { 275 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"); 276 return 0; 277 } 278 279 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 280 "%08x %08x %08x %08x %08x %08x " 281 "%08x %08x %08x %08x\n", 282 dst_entries_get_slow(&ipv4_dst_ops), 283 0, /* st->in_hit */ 284 st->in_slow_tot, 285 st->in_slow_mc, 286 st->in_no_route, 287 st->in_brd, 288 st->in_martian_dst, 289 st->in_martian_src, 290 291 0, /* st->out_hit */ 292 st->out_slow_tot, 293 st->out_slow_mc, 294 295 0, /* st->gc_total */ 296 0, /* st->gc_ignored */ 297 0, /* st->gc_goal_miss */ 298 0, /* st->gc_dst_overflow */ 299 0, /* st->in_hlist_search */ 300 0 /* st->out_hlist_search */ 301 ); 302 return 0; 303 } 304 305 static const struct seq_operations rt_cpu_seq_ops = { 306 .start = rt_cpu_seq_start, 307 .next = rt_cpu_seq_next, 308 .stop = rt_cpu_seq_stop, 309 .show = rt_cpu_seq_show, 310 }; 311 312 #ifdef CONFIG_IP_ROUTE_CLASSID 313 static int rt_acct_proc_show(struct seq_file *m, void *v) 314 { 315 struct ip_rt_acct *dst, *src; 316 unsigned int i, j; 317 318 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 319 if (!dst) 320 return -ENOMEM; 321 322 for_each_possible_cpu(i) { 323 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 324 for (j = 0; j < 256; j++) { 325 dst[j].o_bytes += src[j].o_bytes; 326 dst[j].o_packets += src[j].o_packets; 327 dst[j].i_bytes += src[j].i_bytes; 328 dst[j].i_packets += src[j].i_packets; 329 } 330 } 331 332 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 333 kfree(dst); 334 return 0; 335 } 336 #endif 337 338 static int __net_init ip_rt_do_proc_init(struct net *net) 339 { 340 struct proc_dir_entry *pde; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 343 &rt_cache_seq_ops); 344 if (!pde) 345 goto err1; 346 347 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 348 &rt_cpu_seq_ops); 349 if (!pde) 350 goto err2; 351 352 #ifdef CONFIG_IP_ROUTE_CLASSID 353 pde = proc_create_single("rt_acct", 0, net->proc_net, 354 rt_acct_proc_show); 355 if (!pde) 356 goto err3; 357 #endif 358 return 0; 359 360 #ifdef CONFIG_IP_ROUTE_CLASSID 361 err3: 362 remove_proc_entry("rt_cache", net->proc_net_stat); 363 #endif 364 err2: 365 remove_proc_entry("rt_cache", net->proc_net); 366 err1: 367 return -ENOMEM; 368 } 369 370 static void __net_exit ip_rt_do_proc_exit(struct net *net) 371 { 372 remove_proc_entry("rt_cache", net->proc_net_stat); 373 remove_proc_entry("rt_cache", net->proc_net); 374 #ifdef CONFIG_IP_ROUTE_CLASSID 375 remove_proc_entry("rt_acct", net->proc_net); 376 #endif 377 } 378 379 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 380 .init = ip_rt_do_proc_init, 381 .exit = ip_rt_do_proc_exit, 382 }; 383 384 static int __init ip_rt_proc_init(void) 385 { 386 return register_pernet_subsys(&ip_rt_proc_ops); 387 } 388 389 #else 390 static inline int ip_rt_proc_init(void) 391 { 392 return 0; 393 } 394 #endif /* CONFIG_PROC_FS */ 395 396 static inline bool rt_is_expired(const struct rtable *rth) 397 { 398 bool res; 399 400 rcu_read_lock(); 401 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev)); 402 rcu_read_unlock(); 403 404 return res; 405 } 406 407 void rt_cache_flush(struct net *net) 408 { 409 rt_genid_bump_ipv4(net); 410 } 411 412 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 413 struct sk_buff *skb, 414 const void *daddr) 415 { 416 const struct rtable *rt = container_of(dst, struct rtable, dst); 417 struct net_device *dev; 418 struct neighbour *n; 419 420 rcu_read_lock(); 421 dev = dst_dev_rcu(dst); 422 if (likely(rt->rt_gw_family == AF_INET)) { 423 n = ip_neigh_gw4(dev, rt->rt_gw4); 424 } else if (rt->rt_gw_family == AF_INET6) { 425 n = ip_neigh_gw6(dev, &rt->rt_gw6); 426 } else { 427 __be32 pkey; 428 429 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 430 n = ip_neigh_gw4(dev, pkey); 431 } 432 433 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 434 n = NULL; 435 436 rcu_read_unlock(); 437 438 return n; 439 } 440 441 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 442 { 443 const struct rtable *rt = container_of(dst, struct rtable, dst); 444 struct net_device *dev = dst_dev(dst); 445 const __be32 *pkey = daddr; 446 447 if (rt->rt_gw_family == AF_INET) { 448 pkey = (const __be32 *)&rt->rt_gw4; 449 } else if (rt->rt_gw_family == AF_INET6) { 450 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 451 } else if (!daddr || 452 (rt->rt_flags & 453 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 454 return; 455 } 456 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 457 } 458 459 /* Hash tables of size 2048..262144 depending on RAM size. 460 * Each bucket uses 8 bytes. 461 */ 462 static u32 ip_idents_mask __read_mostly; 463 static atomic_t *ip_idents __read_mostly; 464 static u32 *ip_tstamps __read_mostly; 465 466 /* In order to protect privacy, we add a perturbation to identifiers 467 * if one generator is seldom used. This makes hard for an attacker 468 * to infer how many packets were sent between two points in time. 469 */ 470 static u32 ip_idents_reserve(u32 hash, int segs) 471 { 472 u32 bucket, old, now = (u32)jiffies; 473 atomic_t *p_id; 474 u32 *p_tstamp; 475 u32 delta = 0; 476 477 bucket = hash & ip_idents_mask; 478 p_tstamp = ip_tstamps + bucket; 479 p_id = ip_idents + bucket; 480 old = READ_ONCE(*p_tstamp); 481 482 if (old != now && cmpxchg(p_tstamp, old, now) == old) 483 delta = get_random_u32_below(now - old); 484 485 /* If UBSAN reports an error there, please make sure your compiler 486 * supports -fno-strict-overflow before reporting it that was a bug 487 * in UBSAN, and it has been fixed in GCC-8. 488 */ 489 return atomic_add_return(segs + delta, p_id) - segs; 490 } 491 492 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 493 { 494 u32 hash, id; 495 496 /* Note the following code is not safe, but this is okay. */ 497 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 498 get_random_bytes(&net->ipv4.ip_id_key, 499 sizeof(net->ipv4.ip_id_key)); 500 501 hash = siphash_3u32((__force u32)iph->daddr, 502 (__force u32)iph->saddr, 503 iph->protocol, 504 &net->ipv4.ip_id_key); 505 id = ip_idents_reserve(hash, segs); 506 iph->id = htons(id); 507 } 508 EXPORT_SYMBOL(__ip_select_ident); 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 & INET_DSCP_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), 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, 561 sk_uid(sk)); 562 rcu_read_unlock(); 563 } 564 565 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 566 const struct sk_buff *skb) 567 { 568 if (skb) 569 build_skb_flow_key(fl4, skb, sk); 570 else 571 build_sk_flow_key(fl4, sk); 572 } 573 574 static DEFINE_SPINLOCK(fnhe_lock); 575 576 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 577 { 578 struct rtable *rt; 579 580 rt = rcu_dereference(fnhe->fnhe_rth_input); 581 if (rt) { 582 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 583 dst_dev_put(&rt->dst); 584 dst_release(&rt->dst); 585 } 586 rt = rcu_dereference(fnhe->fnhe_rth_output); 587 if (rt) { 588 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 589 dst_dev_put(&rt->dst); 590 dst_release(&rt->dst); 591 } 592 } 593 594 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 595 { 596 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 597 struct fib_nh_exception *fnhe, *oldest = NULL; 598 599 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 600 fnhe = rcu_dereference_protected(*fnhe_p, 601 lockdep_is_held(&fnhe_lock)); 602 if (!fnhe) 603 break; 604 if (!oldest || 605 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 606 oldest = fnhe; 607 oldest_p = fnhe_p; 608 } 609 } 610 fnhe_flush_routes(oldest); 611 *oldest_p = oldest->fnhe_next; 612 kfree_rcu(oldest, rcu); 613 } 614 615 static u32 fnhe_hashfun(__be32 daddr) 616 { 617 static siphash_aligned_key_t fnhe_hash_key; 618 u64 hval; 619 620 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 621 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 622 return hash_64(hval, FNHE_HASH_SHIFT); 623 } 624 625 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 626 { 627 rt->rt_pmtu = fnhe->fnhe_pmtu; 628 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 629 rt->dst.expires = fnhe->fnhe_expires; 630 631 if (fnhe->fnhe_gw) { 632 rt->rt_flags |= RTCF_REDIRECTED; 633 rt->rt_uses_gateway = 1; 634 rt->rt_gw_family = AF_INET; 635 rt->rt_gw4 = fnhe->fnhe_gw; 636 } 637 } 638 639 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 640 __be32 gw, u32 pmtu, bool lock, 641 unsigned long expires) 642 { 643 struct fnhe_hash_bucket *hash; 644 struct fib_nh_exception *fnhe; 645 struct rtable *rt; 646 u32 genid, hval; 647 unsigned int i; 648 int depth; 649 650 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 651 hval = fnhe_hashfun(daddr); 652 653 spin_lock_bh(&fnhe_lock); 654 655 hash = rcu_dereference(nhc->nhc_exceptions); 656 if (!hash) { 657 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 658 if (!hash) 659 goto out_unlock; 660 rcu_assign_pointer(nhc->nhc_exceptions, hash); 661 } 662 663 hash += hval; 664 665 depth = 0; 666 for (fnhe = rcu_dereference(hash->chain); fnhe; 667 fnhe = rcu_dereference(fnhe->fnhe_next)) { 668 if (fnhe->fnhe_daddr == daddr) 669 break; 670 depth++; 671 } 672 673 if (fnhe) { 674 if (fnhe->fnhe_genid != genid) 675 fnhe->fnhe_genid = genid; 676 if (gw) 677 fnhe->fnhe_gw = gw; 678 if (pmtu) { 679 fnhe->fnhe_pmtu = pmtu; 680 fnhe->fnhe_mtu_locked = lock; 681 } 682 fnhe->fnhe_expires = max(1UL, expires); 683 /* Update all cached dsts too */ 684 rt = rcu_dereference(fnhe->fnhe_rth_input); 685 if (rt) 686 fill_route_from_fnhe(rt, fnhe); 687 rt = rcu_dereference(fnhe->fnhe_rth_output); 688 if (rt) 689 fill_route_from_fnhe(rt, fnhe); 690 } else { 691 /* Randomize max depth to avoid some side channels attacks. */ 692 int max_depth = FNHE_RECLAIM_DEPTH + 693 get_random_u32_below(FNHE_RECLAIM_DEPTH); 694 695 while (depth > max_depth) { 696 fnhe_remove_oldest(hash); 697 depth--; 698 } 699 700 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 701 if (!fnhe) 702 goto out_unlock; 703 704 fnhe->fnhe_next = hash->chain; 705 706 fnhe->fnhe_genid = genid; 707 fnhe->fnhe_daddr = daddr; 708 fnhe->fnhe_gw = gw; 709 fnhe->fnhe_pmtu = pmtu; 710 fnhe->fnhe_mtu_locked = lock; 711 fnhe->fnhe_expires = max(1UL, expires); 712 713 rcu_assign_pointer(hash->chain, fnhe); 714 715 /* Exception created; mark the cached routes for the nexthop 716 * stale, so anyone caching it rechecks if this exception 717 * applies to them. 718 */ 719 rt = rcu_dereference(nhc->nhc_rth_input); 720 if (rt) 721 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 722 723 for_each_possible_cpu(i) { 724 struct rtable __rcu **prt; 725 726 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 727 rt = rcu_dereference(*prt); 728 if (rt) 729 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 730 } 731 } 732 733 fnhe->fnhe_stamp = jiffies; 734 735 out_unlock: 736 spin_unlock_bh(&fnhe_lock); 737 } 738 739 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 740 bool kill_route) 741 { 742 __be32 new_gw = icmp_hdr(skb)->un.gateway; 743 __be32 old_gw = ip_hdr(skb)->saddr; 744 struct net_device *dev = skb->dev; 745 struct in_device *in_dev; 746 struct fib_result res; 747 struct neighbour *n; 748 struct net *net; 749 750 switch (icmp_hdr(skb)->code & 7) { 751 case ICMP_REDIR_NET: 752 case ICMP_REDIR_NETTOS: 753 case ICMP_REDIR_HOST: 754 case ICMP_REDIR_HOSTTOS: 755 break; 756 757 default: 758 return; 759 } 760 761 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 762 return; 763 764 in_dev = __in_dev_get_rcu(dev); 765 if (!in_dev) 766 return; 767 768 net = dev_net(dev); 769 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 770 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 771 ipv4_is_zeronet(new_gw)) 772 goto reject_redirect; 773 774 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 775 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 776 goto reject_redirect; 777 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 778 goto reject_redirect; 779 } else { 780 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 781 goto reject_redirect; 782 } 783 784 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 785 if (!n) 786 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 787 if (!IS_ERR(n)) { 788 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 789 neigh_event_send(n, NULL); 790 } else { 791 if (fib_lookup(net, fl4, &res, 0) == 0) { 792 struct fib_nh_common *nhc; 793 794 fib_select_path(net, &res, fl4, skb); 795 nhc = FIB_RES_NHC(res); 796 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 797 0, false, 798 jiffies + ip_rt_gc_timeout); 799 } 800 if (kill_route) 801 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 802 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 803 } 804 neigh_release(n); 805 } 806 return; 807 808 reject_redirect: 809 #ifdef CONFIG_IP_ROUTE_VERBOSE 810 if (IN_DEV_LOG_MARTIANS(in_dev)) { 811 const struct iphdr *iph = (const struct iphdr *) skb->data; 812 __be32 daddr = iph->daddr; 813 __be32 saddr = iph->saddr; 814 815 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 816 " Advised path = %pI4 -> %pI4\n", 817 &old_gw, dev->name, &new_gw, 818 &saddr, &daddr); 819 } 820 #endif 821 ; 822 } 823 824 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 825 { 826 struct rtable *rt; 827 struct flowi4 fl4; 828 const struct iphdr *iph = (const struct iphdr *) skb->data; 829 struct net *net = dev_net(skb->dev); 830 int oif = skb->dev->ifindex; 831 u8 prot = iph->protocol; 832 u32 mark = skb->mark; 833 __u8 tos = iph->tos; 834 835 rt = dst_rtable(dst); 836 837 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 838 __ip_do_redirect(rt, skb, &fl4, true); 839 } 840 841 static void ipv4_negative_advice(struct sock *sk, 842 struct dst_entry *dst) 843 { 844 struct rtable *rt = dst_rtable(dst); 845 846 if ((READ_ONCE(dst->obsolete) > 0) || 847 (rt->rt_flags & RTCF_REDIRECTED) || 848 READ_ONCE(rt->dst.expires)) 849 sk_dst_reset(sk); 850 } 851 852 /* 853 * Algorithm: 854 * 1. The first ip_rt_redirect_number redirects are sent 855 * with exponential backoff, then we stop sending them at all, 856 * assuming that the host ignores our redirects. 857 * 2. If we did not see packets requiring redirects 858 * during ip_rt_redirect_silence, we assume that the host 859 * forgot redirected route and start to send redirects again. 860 * 861 * This algorithm is much cheaper and more intelligent than dumb load limiting 862 * in icmp.c. 863 * 864 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 865 * and "frag. need" (breaks PMTU discovery) in icmp.c. 866 */ 867 868 void ip_rt_send_redirect(struct sk_buff *skb) 869 { 870 struct rtable *rt = skb_rtable(skb); 871 struct in_device *in_dev; 872 struct inet_peer *peer; 873 struct net *net; 874 int log_martians; 875 int vif; 876 877 rcu_read_lock(); 878 in_dev = __in_dev_get_rcu(rt->dst.dev); 879 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 880 rcu_read_unlock(); 881 return; 882 } 883 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 884 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 885 886 net = dev_net(rt->dst.dev); 887 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 888 if (!peer) { 889 rcu_read_unlock(); 890 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 891 rt_nexthop(rt, ip_hdr(skb)->daddr)); 892 return; 893 } 894 895 /* No redirected packets during ip_rt_redirect_silence; 896 * reset the algorithm. 897 */ 898 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 899 peer->rate_tokens = 0; 900 peer->n_redirects = 0; 901 } 902 903 /* Too many ignored redirects; do not send anything 904 * set dst.rate_last to the last seen redirected packet. 905 */ 906 if (peer->n_redirects >= ip_rt_redirect_number) { 907 peer->rate_last = jiffies; 908 goto out_unlock; 909 } 910 911 /* Check for load limit; set rate_last to the latest sent 912 * redirect. 913 */ 914 if (peer->n_redirects == 0 || 915 time_after(jiffies, 916 (peer->rate_last + 917 (ip_rt_redirect_load << peer->n_redirects)))) { 918 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 919 920 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 921 peer->rate_last = jiffies; 922 ++peer->n_redirects; 923 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 924 peer->n_redirects == ip_rt_redirect_number) 925 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 926 &ip_hdr(skb)->saddr, inet_iif(skb), 927 &ip_hdr(skb)->daddr, &gw); 928 } 929 out_unlock: 930 rcu_read_unlock(); 931 } 932 933 static int ip_error(struct sk_buff *skb) 934 { 935 struct rtable *rt = skb_rtable(skb); 936 struct net_device *dev = skb->dev; 937 struct in_device *in_dev; 938 struct inet_peer *peer; 939 unsigned long now; 940 struct net *net; 941 SKB_DR(reason); 942 bool send; 943 int code; 944 945 if (netif_is_l3_master(skb->dev)) { 946 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 947 if (!dev) 948 goto out; 949 } 950 951 in_dev = __in_dev_get_rcu(dev); 952 953 /* IP on this device is disabled. */ 954 if (!in_dev) 955 goto out; 956 957 net = dev_net(rt->dst.dev); 958 if (!IN_DEV_FORWARD(in_dev)) { 959 switch (rt->dst.error) { 960 case EHOSTUNREACH: 961 SKB_DR_SET(reason, IP_INADDRERRORS); 962 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 963 break; 964 965 case ENETUNREACH: 966 SKB_DR_SET(reason, IP_INNOROUTES); 967 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 968 break; 969 } 970 goto out; 971 } 972 973 switch (rt->dst.error) { 974 case EINVAL: 975 default: 976 goto out; 977 case EHOSTUNREACH: 978 code = ICMP_HOST_UNREACH; 979 break; 980 case ENETUNREACH: 981 code = ICMP_NET_UNREACH; 982 SKB_DR_SET(reason, IP_INNOROUTES); 983 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 984 break; 985 case EACCES: 986 code = ICMP_PKT_FILTERED; 987 break; 988 } 989 990 rcu_read_lock(); 991 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 992 l3mdev_master_ifindex_rcu(skb->dev)); 993 send = true; 994 if (peer) { 995 now = jiffies; 996 peer->rate_tokens += now - peer->rate_last; 997 if (peer->rate_tokens > ip_rt_error_burst) 998 peer->rate_tokens = ip_rt_error_burst; 999 peer->rate_last = now; 1000 if (peer->rate_tokens >= ip_rt_error_cost) 1001 peer->rate_tokens -= ip_rt_error_cost; 1002 else 1003 send = false; 1004 } 1005 rcu_read_unlock(); 1006 1007 if (send) 1008 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1009 1010 out: kfree_skb_reason(skb, reason); 1011 return 0; 1012 } 1013 1014 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1015 { 1016 struct dst_entry *dst = &rt->dst; 1017 struct fib_result res; 1018 bool lock = false; 1019 struct net *net; 1020 u32 old_mtu; 1021 1022 if (ip_mtu_locked(dst)) 1023 return; 1024 1025 old_mtu = ipv4_mtu(dst); 1026 if (old_mtu < mtu) 1027 return; 1028 1029 rcu_read_lock(); 1030 net = dst_dev_net_rcu(dst); 1031 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1032 lock = true; 1033 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1034 } 1035 1036 if (rt->rt_pmtu == mtu && !lock && 1037 time_before(jiffies, READ_ONCE(dst->expires) - 1038 net->ipv4.ip_rt_mtu_expires / 2)) 1039 goto out; 1040 1041 if (fib_lookup(net, fl4, &res, 0) == 0) { 1042 struct fib_nh_common *nhc; 1043 1044 fib_select_path(net, &res, fl4, NULL); 1045 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1046 if (fib_info_num_path(res.fi) > 1) { 1047 int nhsel; 1048 1049 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1050 nhc = fib_info_nhc(res.fi, nhsel); 1051 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1052 jiffies + net->ipv4.ip_rt_mtu_expires); 1053 } 1054 goto out; 1055 } 1056 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1057 nhc = FIB_RES_NHC(res); 1058 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1059 jiffies + net->ipv4.ip_rt_mtu_expires); 1060 } 1061 out: 1062 rcu_read_unlock(); 1063 } 1064 1065 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1066 struct sk_buff *skb, u32 mtu, 1067 bool confirm_neigh) 1068 { 1069 struct rtable *rt = dst_rtable(dst); 1070 struct flowi4 fl4; 1071 1072 ip_rt_build_flow_key(&fl4, sk, skb); 1073 1074 /* Don't make lookup fail for bridged encapsulations */ 1075 if (skb && netif_is_any_bridge_port(skb->dev)) 1076 fl4.flowi4_oif = 0; 1077 1078 __ip_rt_update_pmtu(rt, &fl4, mtu); 1079 } 1080 1081 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1082 int oif, u8 protocol) 1083 { 1084 const struct iphdr *iph = (const struct iphdr *)skb->data; 1085 struct flowi4 fl4; 1086 struct rtable *rt; 1087 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1088 1089 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1090 0); 1091 rt = __ip_route_output_key(net, &fl4); 1092 if (!IS_ERR(rt)) { 1093 __ip_rt_update_pmtu(rt, &fl4, mtu); 1094 ip_rt_put(rt); 1095 } 1096 } 1097 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1098 1099 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1100 { 1101 const struct iphdr *iph = (const struct iphdr *)skb->data; 1102 struct flowi4 fl4; 1103 struct rtable *rt; 1104 1105 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1106 1107 if (!fl4.flowi4_mark) 1108 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1109 1110 rt = __ip_route_output_key(sock_net(sk), &fl4); 1111 if (!IS_ERR(rt)) { 1112 __ip_rt_update_pmtu(rt, &fl4, mtu); 1113 ip_rt_put(rt); 1114 } 1115 } 1116 1117 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1118 { 1119 const struct iphdr *iph = (const struct iphdr *)skb->data; 1120 struct flowi4 fl4; 1121 struct rtable *rt; 1122 struct dst_entry *odst = NULL; 1123 bool new = false; 1124 struct net *net = sock_net(sk); 1125 1126 bh_lock_sock(sk); 1127 1128 if (!ip_sk_accept_pmtu(sk)) 1129 goto out; 1130 1131 odst = sk_dst_get(sk); 1132 1133 if (sock_owned_by_user(sk) || !odst) { 1134 __ipv4_sk_update_pmtu(skb, sk, mtu); 1135 goto out; 1136 } 1137 1138 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1139 1140 rt = dst_rtable(odst); 1141 if (READ_ONCE(odst->obsolete) && !odst->ops->check(odst, 0)) { 1142 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1143 if (IS_ERR(rt)) 1144 goto out; 1145 1146 new = true; 1147 } 1148 1149 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1150 1151 if (!dst_check(&rt->dst, 0)) { 1152 if (new) 1153 dst_release(&rt->dst); 1154 1155 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1156 if (IS_ERR(rt)) 1157 goto out; 1158 1159 new = true; 1160 } 1161 1162 if (new) 1163 sk_dst_set(sk, &rt->dst); 1164 1165 out: 1166 bh_unlock_sock(sk); 1167 dst_release(odst); 1168 } 1169 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1170 1171 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1172 int oif, u8 protocol) 1173 { 1174 const struct iphdr *iph = (const struct iphdr *)skb->data; 1175 struct flowi4 fl4; 1176 struct rtable *rt; 1177 1178 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1179 rt = __ip_route_output_key(net, &fl4); 1180 if (!IS_ERR(rt)) { 1181 __ip_do_redirect(rt, skb, &fl4, false); 1182 ip_rt_put(rt); 1183 } 1184 } 1185 EXPORT_SYMBOL_GPL(ipv4_redirect); 1186 1187 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1188 { 1189 const struct iphdr *iph = (const struct iphdr *)skb->data; 1190 struct flowi4 fl4; 1191 struct rtable *rt; 1192 struct net *net = sock_net(sk); 1193 1194 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1195 rt = __ip_route_output_key(net, &fl4); 1196 if (!IS_ERR(rt)) { 1197 __ip_do_redirect(rt, skb, &fl4, false); 1198 ip_rt_put(rt); 1199 } 1200 } 1201 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1202 1203 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1204 u32 cookie) 1205 { 1206 struct rtable *rt = dst_rtable(dst); 1207 1208 /* All IPV4 dsts are created with ->obsolete set to the value 1209 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1210 * into this function always. 1211 * 1212 * When a PMTU/redirect information update invalidates a route, 1213 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1214 * DST_OBSOLETE_DEAD. 1215 */ 1216 if (READ_ONCE(dst->obsolete) != DST_OBSOLETE_FORCE_CHK || 1217 rt_is_expired(rt)) 1218 return NULL; 1219 return dst; 1220 } 1221 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1222 1223 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1224 { 1225 struct inet_skb_parm parm; 1226 struct net_device *dev; 1227 int res; 1228 1229 /* Recompile ip options since IPCB may not be valid anymore. 1230 * Also check we have a reasonable ipv4 header. 1231 */ 1232 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1233 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1234 return; 1235 1236 memset(&parm, 0, sizeof(parm)); 1237 if (ip_hdr(skb)->ihl > 5) { 1238 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1239 return; 1240 parm.opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1241 1242 rcu_read_lock(); 1243 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1244 res = __ip_options_compile(dev_net(dev), &parm.opt, skb, NULL); 1245 rcu_read_unlock(); 1246 1247 if (res) 1248 return; 1249 } 1250 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &parm); 1251 } 1252 1253 static void ipv4_link_failure(struct sk_buff *skb) 1254 { 1255 struct rtable *rt; 1256 1257 ipv4_send_dest_unreach(skb); 1258 1259 rt = skb_rtable(skb); 1260 if (rt) 1261 dst_set_expires(&rt->dst, 0); 1262 } 1263 1264 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1265 { 1266 pr_debug("%s: %pI4 -> %pI4, %s\n", 1267 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1268 skb->dev ? skb->dev->name : "?"); 1269 kfree_skb(skb); 1270 WARN_ON(1); 1271 return 0; 1272 } 1273 1274 /* 1275 * We do not cache source address of outgoing interface, 1276 * because it is used only by IP RR, TS and SRR options, 1277 * so that it out of fast path. 1278 * 1279 * BTW remember: "addr" is allowed to be not aligned 1280 * in IP options! 1281 */ 1282 1283 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1284 { 1285 __be32 src; 1286 1287 if (rt_is_output_route(rt)) 1288 src = ip_hdr(skb)->saddr; 1289 else { 1290 struct fib_result res; 1291 struct iphdr *iph = ip_hdr(skb); 1292 struct flowi4 fl4 = { 1293 .daddr = iph->daddr, 1294 .saddr = iph->saddr, 1295 .flowi4_dscp = ip4h_dscp(iph), 1296 .flowi4_oif = rt->dst.dev->ifindex, 1297 .flowi4_iif = skb->dev->ifindex, 1298 .flowi4_mark = skb->mark, 1299 }; 1300 1301 rcu_read_lock(); 1302 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1303 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1304 else 1305 src = inet_select_addr(rt->dst.dev, 1306 rt_nexthop(rt, iph->daddr), 1307 RT_SCOPE_UNIVERSE); 1308 rcu_read_unlock(); 1309 } 1310 memcpy(addr, &src, 4); 1311 } 1312 1313 #ifdef CONFIG_IP_ROUTE_CLASSID 1314 static void set_class_tag(struct rtable *rt, u32 tag) 1315 { 1316 if (!(rt->dst.tclassid & 0xFFFF)) 1317 rt->dst.tclassid |= tag & 0xFFFF; 1318 if (!(rt->dst.tclassid & 0xFFFF0000)) 1319 rt->dst.tclassid |= tag & 0xFFFF0000; 1320 } 1321 #endif 1322 1323 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1324 { 1325 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1326 unsigned int advmss; 1327 struct net *net; 1328 1329 rcu_read_lock(); 1330 net = dst_dev_net_rcu(dst); 1331 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1332 net->ipv4.ip_rt_min_advmss); 1333 rcu_read_unlock(); 1334 1335 return min(advmss, IPV4_MAX_PMTU - header_size); 1336 } 1337 1338 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1339 { 1340 return ip_dst_mtu_maybe_forward(dst, false); 1341 } 1342 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1343 1344 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1345 { 1346 struct fnhe_hash_bucket *hash; 1347 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1348 u32 hval = fnhe_hashfun(daddr); 1349 1350 spin_lock_bh(&fnhe_lock); 1351 1352 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1353 lockdep_is_held(&fnhe_lock)); 1354 hash += hval; 1355 1356 fnhe_p = &hash->chain; 1357 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1358 while (fnhe) { 1359 if (fnhe->fnhe_daddr == daddr) { 1360 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1361 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1362 /* set fnhe_daddr to 0 to ensure it won't bind with 1363 * new dsts in rt_bind_exception(). 1364 */ 1365 fnhe->fnhe_daddr = 0; 1366 fnhe_flush_routes(fnhe); 1367 kfree_rcu(fnhe, rcu); 1368 break; 1369 } 1370 fnhe_p = &fnhe->fnhe_next; 1371 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1372 lockdep_is_held(&fnhe_lock)); 1373 } 1374 1375 spin_unlock_bh(&fnhe_lock); 1376 } 1377 1378 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1379 __be32 daddr) 1380 { 1381 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1382 struct fib_nh_exception *fnhe; 1383 u32 hval; 1384 1385 if (!hash) 1386 return NULL; 1387 1388 hval = fnhe_hashfun(daddr); 1389 1390 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1391 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1392 if (fnhe->fnhe_daddr == daddr) { 1393 if (fnhe->fnhe_expires && 1394 time_after(jiffies, fnhe->fnhe_expires)) { 1395 ip_del_fnhe(nhc, daddr); 1396 break; 1397 } 1398 return fnhe; 1399 } 1400 } 1401 return NULL; 1402 } 1403 1404 /* MTU selection: 1405 * 1. mtu on route is locked - use it 1406 * 2. mtu from nexthop exception 1407 * 3. mtu from egress device 1408 */ 1409 1410 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1411 { 1412 struct fib_nh_common *nhc = res->nhc; 1413 struct net_device *dev = nhc->nhc_dev; 1414 struct fib_info *fi = res->fi; 1415 u32 mtu = 0; 1416 1417 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1418 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1419 mtu = fi->fib_mtu; 1420 1421 if (likely(!mtu)) { 1422 struct fib_nh_exception *fnhe; 1423 1424 fnhe = find_exception(nhc, daddr); 1425 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1426 mtu = fnhe->fnhe_pmtu; 1427 } 1428 1429 if (likely(!mtu)) 1430 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1431 1432 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1433 } 1434 1435 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1436 __be32 daddr, const bool do_cache) 1437 { 1438 bool ret = false; 1439 1440 spin_lock_bh(&fnhe_lock); 1441 1442 if (daddr == fnhe->fnhe_daddr) { 1443 struct rtable __rcu **porig; 1444 struct rtable *orig; 1445 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1446 1447 if (rt_is_input_route(rt)) 1448 porig = &fnhe->fnhe_rth_input; 1449 else 1450 porig = &fnhe->fnhe_rth_output; 1451 orig = rcu_dereference(*porig); 1452 1453 if (fnhe->fnhe_genid != genid) { 1454 fnhe->fnhe_genid = genid; 1455 fnhe->fnhe_gw = 0; 1456 fnhe->fnhe_pmtu = 0; 1457 fnhe->fnhe_expires = 0; 1458 fnhe->fnhe_mtu_locked = false; 1459 fnhe_flush_routes(fnhe); 1460 orig = NULL; 1461 } 1462 fill_route_from_fnhe(rt, fnhe); 1463 if (!rt->rt_gw4) { 1464 rt->rt_gw4 = daddr; 1465 rt->rt_gw_family = AF_INET; 1466 } 1467 1468 if (do_cache) { 1469 dst_hold(&rt->dst); 1470 rcu_assign_pointer(*porig, rt); 1471 if (orig) { 1472 dst_dev_put(&orig->dst); 1473 dst_release(&orig->dst); 1474 } 1475 ret = true; 1476 } 1477 1478 fnhe->fnhe_stamp = jiffies; 1479 } 1480 spin_unlock_bh(&fnhe_lock); 1481 1482 return ret; 1483 } 1484 1485 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1486 { 1487 struct rtable *orig, *prev, **p; 1488 bool ret = true; 1489 1490 if (rt_is_input_route(rt)) { 1491 p = (struct rtable **)&nhc->nhc_rth_input; 1492 } else { 1493 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1494 } 1495 orig = *p; 1496 1497 /* hold dst before doing cmpxchg() to avoid race condition 1498 * on this dst 1499 */ 1500 dst_hold(&rt->dst); 1501 prev = cmpxchg(p, orig, rt); 1502 if (prev == orig) { 1503 if (orig) { 1504 rt_add_uncached_list(orig); 1505 dst_release(&orig->dst); 1506 } 1507 } else { 1508 dst_release(&rt->dst); 1509 ret = false; 1510 } 1511 1512 return ret; 1513 } 1514 1515 struct uncached_list { 1516 spinlock_t lock; 1517 struct list_head head; 1518 }; 1519 1520 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1521 1522 void rt_add_uncached_list(struct rtable *rt) 1523 { 1524 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1525 1526 rt->dst.rt_uncached_list = ul; 1527 1528 spin_lock_bh(&ul->lock); 1529 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1530 spin_unlock_bh(&ul->lock); 1531 } 1532 1533 void rt_del_uncached_list(struct rtable *rt) 1534 { 1535 if (!list_empty(&rt->dst.rt_uncached)) { 1536 struct uncached_list *ul = rt->dst.rt_uncached_list; 1537 1538 spin_lock_bh(&ul->lock); 1539 list_del_init(&rt->dst.rt_uncached); 1540 spin_unlock_bh(&ul->lock); 1541 } 1542 } 1543 1544 static void ipv4_dst_destroy(struct dst_entry *dst) 1545 { 1546 ip_dst_metrics_put(dst); 1547 rt_del_uncached_list(dst_rtable(dst)); 1548 } 1549 1550 void rt_flush_dev(struct net_device *dev) 1551 { 1552 struct rtable *rt, *safe; 1553 int cpu; 1554 1555 for_each_possible_cpu(cpu) { 1556 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1557 1558 if (list_empty(&ul->head)) 1559 continue; 1560 1561 spin_lock_bh(&ul->lock); 1562 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1563 if (rt->dst.dev != dev) 1564 continue; 1565 rt->dst.dev = blackhole_netdev; 1566 netdev_ref_replace(dev, blackhole_netdev, 1567 &rt->dst.dev_tracker, GFP_ATOMIC); 1568 list_del_init(&rt->dst.rt_uncached); 1569 } 1570 spin_unlock_bh(&ul->lock); 1571 } 1572 } 1573 1574 static bool rt_cache_valid(const struct rtable *rt) 1575 { 1576 return rt && 1577 READ_ONCE(rt->dst.obsolete) == DST_OBSOLETE_FORCE_CHK && 1578 !rt_is_expired(rt); 1579 } 1580 1581 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1582 const struct fib_result *res, 1583 struct fib_nh_exception *fnhe, 1584 struct fib_info *fi, u16 type, u32 itag, 1585 const bool do_cache) 1586 { 1587 bool cached = false; 1588 1589 if (fi) { 1590 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1591 1592 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1593 rt->rt_uses_gateway = 1; 1594 rt->rt_gw_family = nhc->nhc_gw_family; 1595 /* only INET and INET6 are supported */ 1596 if (likely(nhc->nhc_gw_family == AF_INET)) 1597 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1598 else 1599 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1600 } 1601 1602 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1603 1604 #ifdef CONFIG_IP_ROUTE_CLASSID 1605 if (nhc->nhc_family == AF_INET) { 1606 struct fib_nh *nh; 1607 1608 nh = container_of(nhc, struct fib_nh, nh_common); 1609 rt->dst.tclassid = nh->nh_tclassid; 1610 } 1611 #endif 1612 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1613 if (unlikely(fnhe)) 1614 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1615 else if (do_cache) 1616 cached = rt_cache_route(nhc, rt); 1617 if (unlikely(!cached)) { 1618 /* Routes we intend to cache in nexthop exception or 1619 * FIB nexthop have the DST_NOCACHE bit clear. 1620 * However, if we are unsuccessful at storing this 1621 * route into the cache we really need to set it. 1622 */ 1623 if (!rt->rt_gw4) { 1624 rt->rt_gw_family = AF_INET; 1625 rt->rt_gw4 = daddr; 1626 } 1627 rt_add_uncached_list(rt); 1628 } 1629 } else 1630 rt_add_uncached_list(rt); 1631 1632 #ifdef CONFIG_IP_ROUTE_CLASSID 1633 #ifdef CONFIG_IP_MULTIPLE_TABLES 1634 set_class_tag(rt, res->tclassid); 1635 #endif 1636 set_class_tag(rt, itag); 1637 #endif 1638 } 1639 1640 struct rtable *rt_dst_alloc(struct net_device *dev, 1641 unsigned int flags, u16 type, 1642 bool noxfrm) 1643 { 1644 struct rtable *rt; 1645 1646 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1647 (noxfrm ? DST_NOXFRM : 0)); 1648 1649 if (rt) { 1650 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1651 rt->rt_flags = flags; 1652 rt->rt_type = type; 1653 rt->rt_is_input = 0; 1654 rt->rt_iif = 0; 1655 rt->rt_pmtu = 0; 1656 rt->rt_mtu_locked = 0; 1657 rt->rt_uses_gateway = 0; 1658 rt->rt_gw_family = 0; 1659 rt->rt_gw4 = 0; 1660 1661 rt->dst.output = ip_output; 1662 if (flags & RTCF_LOCAL) 1663 rt->dst.input = ip_local_deliver; 1664 } 1665 1666 return rt; 1667 } 1668 EXPORT_SYMBOL(rt_dst_alloc); 1669 1670 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1671 { 1672 struct rtable *new_rt; 1673 1674 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1675 rt->dst.flags); 1676 1677 if (new_rt) { 1678 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1679 new_rt->rt_flags = rt->rt_flags; 1680 new_rt->rt_type = rt->rt_type; 1681 new_rt->rt_is_input = rt->rt_is_input; 1682 new_rt->rt_iif = rt->rt_iif; 1683 new_rt->rt_pmtu = rt->rt_pmtu; 1684 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1685 new_rt->rt_gw_family = rt->rt_gw_family; 1686 if (rt->rt_gw_family == AF_INET) 1687 new_rt->rt_gw4 = rt->rt_gw4; 1688 else if (rt->rt_gw_family == AF_INET6) 1689 new_rt->rt_gw6 = rt->rt_gw6; 1690 1691 new_rt->dst.input = READ_ONCE(rt->dst.input); 1692 new_rt->dst.output = READ_ONCE(rt->dst.output); 1693 new_rt->dst.error = rt->dst.error; 1694 new_rt->dst.lastuse = jiffies; 1695 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1696 } 1697 return new_rt; 1698 } 1699 EXPORT_SYMBOL(rt_dst_clone); 1700 1701 /* called in rcu_read_lock() section */ 1702 enum skb_drop_reason 1703 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1704 dscp_t dscp, struct net_device *dev, 1705 struct in_device *in_dev, u32 *itag) 1706 { 1707 enum skb_drop_reason reason; 1708 1709 /* Primary sanity checks. */ 1710 if (!in_dev) 1711 return SKB_DROP_REASON_NOT_SPECIFIED; 1712 1713 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1714 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1715 1716 if (skb->protocol != htons(ETH_P_IP)) 1717 return SKB_DROP_REASON_INVALID_PROTO; 1718 1719 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1720 return SKB_DROP_REASON_IP_LOCALNET; 1721 1722 if (ipv4_is_zeronet(saddr)) { 1723 if (!ipv4_is_local_multicast(daddr) && 1724 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1725 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1726 } else { 1727 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1728 dev, in_dev, itag); 1729 if (reason) 1730 return reason; 1731 } 1732 return SKB_NOT_DROPPED_YET; 1733 } 1734 1735 /* called in rcu_read_lock() section */ 1736 static enum skb_drop_reason 1737 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1738 dscp_t dscp, struct net_device *dev, int our) 1739 { 1740 struct in_device *in_dev = __in_dev_get_rcu(dev); 1741 unsigned int flags = RTCF_MULTICAST; 1742 enum skb_drop_reason reason; 1743 struct rtable *rth; 1744 u32 itag = 0; 1745 1746 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1747 &itag); 1748 if (reason) 1749 return reason; 1750 1751 if (our) 1752 flags |= RTCF_LOCAL; 1753 1754 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1755 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1756 1757 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1758 false); 1759 if (!rth) 1760 return SKB_DROP_REASON_NOMEM; 1761 1762 #ifdef CONFIG_IP_ROUTE_CLASSID 1763 rth->dst.tclassid = itag; 1764 #endif 1765 rth->dst.output = ip_rt_bug; 1766 rth->rt_is_input= 1; 1767 1768 #ifdef CONFIG_IP_MROUTE 1769 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1770 rth->dst.input = ip_mr_input; 1771 #endif 1772 RT_CACHE_STAT_INC(in_slow_mc); 1773 1774 skb_dst_drop(skb); 1775 skb_dst_set(skb, &rth->dst); 1776 return SKB_NOT_DROPPED_YET; 1777 } 1778 1779 1780 static void ip_handle_martian_source(struct net_device *dev, 1781 struct in_device *in_dev, 1782 struct sk_buff *skb, 1783 __be32 daddr, 1784 __be32 saddr) 1785 { 1786 RT_CACHE_STAT_INC(in_martian_src); 1787 #ifdef CONFIG_IP_ROUTE_VERBOSE 1788 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1789 /* 1790 * RFC1812 recommendation, if source is martian, 1791 * the only hint is MAC header. 1792 */ 1793 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1794 &daddr, &saddr, dev->name); 1795 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1796 print_hex_dump(KERN_WARNING, "ll header: ", 1797 DUMP_PREFIX_OFFSET, 16, 1, 1798 skb_mac_header(skb), 1799 dev->hard_header_len, false); 1800 } 1801 } 1802 #endif 1803 } 1804 1805 /* called in rcu_read_lock() section */ 1806 static enum skb_drop_reason 1807 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1808 struct in_device *in_dev, __be32 daddr, 1809 __be32 saddr, dscp_t dscp) 1810 { 1811 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1812 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1813 struct net_device *dev = nhc->nhc_dev; 1814 struct fib_nh_exception *fnhe; 1815 struct rtable *rth; 1816 int err; 1817 struct in_device *out_dev; 1818 bool do_cache; 1819 u32 itag = 0; 1820 1821 /* get a working reference to the output device */ 1822 out_dev = __in_dev_get_rcu(dev); 1823 if (!out_dev) { 1824 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1825 return reason; 1826 } 1827 1828 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1829 in_dev->dev, in_dev, &itag); 1830 if (err < 0) { 1831 reason = -err; 1832 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1833 saddr); 1834 1835 goto cleanup; 1836 } 1837 1838 do_cache = res->fi && !itag; 1839 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1840 skb->protocol == htons(ETH_P_IP)) { 1841 __be32 gw; 1842 1843 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1844 if (IN_DEV_SHARED_MEDIA(out_dev) || 1845 inet_addr_onlink(out_dev, saddr, gw)) 1846 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1847 } 1848 1849 if (skb->protocol != htons(ETH_P_IP)) { 1850 /* Not IP (i.e. ARP). Do not create route, if it is 1851 * invalid for proxy arp. DNAT routes are always valid. 1852 * 1853 * Proxy arp feature have been extended to allow, ARP 1854 * replies back to the same interface, to support 1855 * Private VLAN switch technologies. See arp.c. 1856 */ 1857 if (out_dev == in_dev && 1858 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1859 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1860 goto cleanup; 1861 } 1862 } 1863 1864 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1865 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1866 1867 fnhe = find_exception(nhc, daddr); 1868 if (do_cache) { 1869 if (fnhe) 1870 rth = rcu_dereference(fnhe->fnhe_rth_input); 1871 else 1872 rth = rcu_dereference(nhc->nhc_rth_input); 1873 if (rt_cache_valid(rth)) { 1874 skb_dst_set_noref(skb, &rth->dst); 1875 goto out; 1876 } 1877 } 1878 1879 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1880 IN_DEV_ORCONF(out_dev, NOXFRM)); 1881 if (!rth) { 1882 reason = SKB_DROP_REASON_NOMEM; 1883 goto cleanup; 1884 } 1885 1886 rth->rt_is_input = 1; 1887 RT_CACHE_STAT_INC(in_slow_tot); 1888 1889 rth->dst.input = ip_forward; 1890 1891 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1892 do_cache); 1893 lwtunnel_set_redirect(&rth->dst); 1894 skb_dst_set(skb, &rth->dst); 1895 out: 1896 reason = SKB_NOT_DROPPED_YET; 1897 cleanup: 1898 return reason; 1899 } 1900 1901 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1902 /* To make ICMP packets follow the right flow, the multipath hash is 1903 * calculated from the inner IP addresses. 1904 */ 1905 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1906 struct flow_keys *hash_keys) 1907 { 1908 const struct iphdr *outer_iph = ip_hdr(skb); 1909 const struct iphdr *key_iph = outer_iph; 1910 const struct iphdr *inner_iph; 1911 const struct icmphdr *icmph; 1912 struct iphdr _inner_iph; 1913 struct icmphdr _icmph; 1914 1915 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1916 goto out; 1917 1918 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1919 goto out; 1920 1921 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1922 &_icmph); 1923 if (!icmph) 1924 goto out; 1925 1926 if (!icmp_is_err(icmph->type)) 1927 goto out; 1928 1929 inner_iph = skb_header_pointer(skb, 1930 outer_iph->ihl * 4 + sizeof(_icmph), 1931 sizeof(_inner_iph), &_inner_iph); 1932 if (!inner_iph) 1933 goto out; 1934 1935 key_iph = inner_iph; 1936 out: 1937 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1938 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1939 } 1940 1941 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1942 const struct sk_buff *skb, 1943 bool *p_has_inner) 1944 { 1945 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1946 struct flow_keys keys, hash_keys; 1947 1948 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1949 return 0; 1950 1951 memset(&hash_keys, 0, sizeof(hash_keys)); 1952 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1953 1954 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1955 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1956 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1957 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1958 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1959 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1960 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1961 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1962 hash_keys.ports.src = keys.ports.src; 1963 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1964 hash_keys.ports.dst = keys.ports.dst; 1965 1966 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1967 return fib_multipath_hash_from_keys(net, &hash_keys); 1968 } 1969 1970 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1971 const struct sk_buff *skb, 1972 bool has_inner) 1973 { 1974 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1975 struct flow_keys keys, hash_keys; 1976 1977 /* We assume the packet carries an encapsulation, but if none was 1978 * encountered during dissection of the outer flow, then there is no 1979 * point in calling the flow dissector again. 1980 */ 1981 if (!has_inner) 1982 return 0; 1983 1984 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1985 return 0; 1986 1987 memset(&hash_keys, 0, sizeof(hash_keys)); 1988 skb_flow_dissect_flow_keys(skb, &keys, 0); 1989 1990 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1991 return 0; 1992 1993 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1994 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1996 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1998 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1999 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2000 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2001 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2002 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2003 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2004 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2005 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2006 hash_keys.tags.flow_label = keys.tags.flow_label; 2007 } 2008 2009 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2010 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2011 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2012 hash_keys.ports.src = keys.ports.src; 2013 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2014 hash_keys.ports.dst = keys.ports.dst; 2015 2016 return fib_multipath_hash_from_keys(net, &hash_keys); 2017 } 2018 2019 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2020 const struct sk_buff *skb) 2021 { 2022 u32 mhash, mhash_inner; 2023 bool has_inner = true; 2024 2025 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2026 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2027 2028 return jhash_2words(mhash, mhash_inner, 0); 2029 } 2030 2031 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2032 const struct flowi4 *fl4) 2033 { 2034 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2035 struct flow_keys hash_keys; 2036 2037 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2038 return 0; 2039 2040 memset(&hash_keys, 0, sizeof(hash_keys)); 2041 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2042 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2043 hash_keys.addrs.v4addrs.src = fl4->saddr; 2044 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2045 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2046 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2047 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2048 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2049 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2050 hash_keys.ports.src = (__force __be16)get_random_u16(); 2051 else 2052 hash_keys.ports.src = fl4->fl4_sport; 2053 } 2054 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2055 hash_keys.ports.dst = fl4->fl4_dport; 2056 2057 return fib_multipath_hash_from_keys(net, &hash_keys); 2058 } 2059 2060 /* if skb is set it will be used and fl4 can be NULL */ 2061 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2062 const struct sk_buff *skb, struct flow_keys *flkeys) 2063 { 2064 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2065 struct flow_keys hash_keys; 2066 u32 mhash = 0; 2067 2068 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2069 case 0: 2070 memset(&hash_keys, 0, sizeof(hash_keys)); 2071 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2072 if (skb) { 2073 ip_multipath_l3_keys(skb, &hash_keys); 2074 } else { 2075 hash_keys.addrs.v4addrs.src = fl4->saddr; 2076 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2077 } 2078 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2079 break; 2080 case 1: 2081 /* skb is currently provided only when forwarding */ 2082 if (skb) { 2083 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2084 struct flow_keys keys; 2085 2086 /* short-circuit if we already have L4 hash present */ 2087 if (skb->l4_hash) 2088 return skb_get_hash_raw(skb) >> 1; 2089 2090 memset(&hash_keys, 0, sizeof(hash_keys)); 2091 2092 if (!flkeys) { 2093 skb_flow_dissect_flow_keys(skb, &keys, flag); 2094 flkeys = &keys; 2095 } 2096 2097 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2098 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2099 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2100 hash_keys.ports.src = flkeys->ports.src; 2101 hash_keys.ports.dst = flkeys->ports.dst; 2102 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2103 } else { 2104 memset(&hash_keys, 0, sizeof(hash_keys)); 2105 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2106 hash_keys.addrs.v4addrs.src = fl4->saddr; 2107 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2108 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2109 hash_keys.ports.src = (__force __be16)get_random_u16(); 2110 else 2111 hash_keys.ports.src = fl4->fl4_sport; 2112 hash_keys.ports.dst = fl4->fl4_dport; 2113 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2114 } 2115 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2116 break; 2117 case 2: 2118 memset(&hash_keys, 0, sizeof(hash_keys)); 2119 /* skb is currently provided only when forwarding */ 2120 if (skb) { 2121 struct flow_keys keys; 2122 2123 skb_flow_dissect_flow_keys(skb, &keys, 0); 2124 /* Inner can be v4 or v6 */ 2125 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2126 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2127 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2128 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2129 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2130 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2131 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2132 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2133 hash_keys.tags.flow_label = keys.tags.flow_label; 2134 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2135 } else { 2136 /* Same as case 0 */ 2137 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2138 ip_multipath_l3_keys(skb, &hash_keys); 2139 } 2140 } else { 2141 /* Same as case 0 */ 2142 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2143 hash_keys.addrs.v4addrs.src = fl4->saddr; 2144 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2145 } 2146 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2147 break; 2148 case 3: 2149 if (skb) 2150 mhash = fib_multipath_custom_hash_skb(net, skb); 2151 else 2152 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2153 break; 2154 } 2155 2156 if (multipath_hash) 2157 mhash = jhash_2words(mhash, multipath_hash, 0); 2158 2159 return mhash >> 1; 2160 } 2161 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2162 2163 static enum skb_drop_reason 2164 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2165 struct in_device *in_dev, __be32 daddr, 2166 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2167 { 2168 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2169 if (res->fi && fib_info_num_path(res->fi) > 1) { 2170 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2171 2172 fib_select_multipath(res, h, NULL); 2173 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2174 } 2175 #endif 2176 2177 /* create a routing cache entry */ 2178 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2179 } 2180 2181 /* Implements all the saddr-related checks as ip_route_input_slow(), 2182 * assuming daddr is valid and the destination is not a local broadcast one. 2183 * Uses the provided hint instead of performing a route lookup. 2184 */ 2185 enum skb_drop_reason 2186 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2187 dscp_t dscp, struct net_device *dev, 2188 const struct sk_buff *hint) 2189 { 2190 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2191 struct in_device *in_dev = __in_dev_get_rcu(dev); 2192 struct rtable *rt = skb_rtable(hint); 2193 struct net *net = dev_net(dev); 2194 u32 tag = 0; 2195 2196 if (!in_dev) 2197 return reason; 2198 2199 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2200 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2201 goto martian_source; 2202 } 2203 2204 if (ipv4_is_zeronet(saddr)) { 2205 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2206 goto martian_source; 2207 } 2208 2209 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2210 reason = SKB_DROP_REASON_IP_LOCALNET; 2211 goto martian_source; 2212 } 2213 2214 if (!(rt->rt_flags & RTCF_LOCAL)) 2215 goto skip_validate_source; 2216 2217 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2218 in_dev, &tag); 2219 if (reason) 2220 goto martian_source; 2221 2222 skip_validate_source: 2223 skb_dst_copy(skb, hint); 2224 return SKB_NOT_DROPPED_YET; 2225 2226 martian_source: 2227 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2228 return reason; 2229 } 2230 2231 /* get device for dst_alloc with local routes */ 2232 static struct net_device *ip_rt_get_dev(struct net *net, 2233 const struct fib_result *res) 2234 { 2235 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2236 struct net_device *dev = NULL; 2237 2238 if (nhc) 2239 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2240 2241 return dev ? : net->loopback_dev; 2242 } 2243 2244 /* 2245 * NOTE. We drop all the packets that has local source 2246 * addresses, because every properly looped back packet 2247 * must have correct destination already attached by output routine. 2248 * Changes in the enforced policies must be applied also to 2249 * ip_route_use_hint(). 2250 * 2251 * Such approach solves two big problems: 2252 * 1. Not simplex devices are handled properly. 2253 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2254 * called with rcu_read_lock() 2255 */ 2256 2257 static enum skb_drop_reason 2258 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2259 dscp_t dscp, struct net_device *dev, 2260 struct fib_result *res) 2261 { 2262 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2263 struct in_device *in_dev = __in_dev_get_rcu(dev); 2264 struct flow_keys *flkeys = NULL, _flkeys; 2265 struct net *net = dev_net(dev); 2266 struct ip_tunnel_info *tun_info; 2267 int err = -EINVAL; 2268 unsigned int flags = 0; 2269 u32 itag = 0; 2270 struct rtable *rth; 2271 struct flowi4 fl4; 2272 bool do_cache = true; 2273 2274 /* IP on this device is disabled. */ 2275 2276 if (!in_dev) 2277 goto out; 2278 2279 /* Check for the most weird martians, which can be not detected 2280 * by fib_lookup. 2281 */ 2282 2283 tun_info = skb_tunnel_info(skb); 2284 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2285 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2286 else 2287 fl4.flowi4_tun_key.tun_id = 0; 2288 skb_dst_drop(skb); 2289 2290 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2291 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2292 goto martian_source; 2293 } 2294 2295 res->fi = NULL; 2296 res->table = NULL; 2297 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2298 goto brd_input; 2299 2300 /* Accept zero addresses only to limited broadcast; 2301 * I even do not know to fix it or not. Waiting for complains :-) 2302 */ 2303 if (ipv4_is_zeronet(saddr)) { 2304 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2305 goto martian_source; 2306 } 2307 2308 if (ipv4_is_zeronet(daddr)) { 2309 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2310 goto martian_destination; 2311 } 2312 2313 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2314 * and call it once if daddr or/and saddr are loopback addresses 2315 */ 2316 if (ipv4_is_loopback(daddr)) { 2317 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2318 reason = SKB_DROP_REASON_IP_LOCALNET; 2319 goto martian_destination; 2320 } 2321 } else if (ipv4_is_loopback(saddr)) { 2322 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2323 reason = SKB_DROP_REASON_IP_LOCALNET; 2324 goto martian_source; 2325 } 2326 } 2327 2328 /* 2329 * Now we are ready to route packet. 2330 */ 2331 fl4.flowi4_l3mdev = 0; 2332 fl4.flowi4_oif = 0; 2333 fl4.flowi4_iif = dev->ifindex; 2334 fl4.flowi4_mark = skb->mark; 2335 fl4.flowi4_dscp = dscp; 2336 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2337 fl4.flowi4_flags = 0; 2338 fl4.daddr = daddr; 2339 fl4.saddr = saddr; 2340 fl4.flowi4_uid = sock_net_uid(net, NULL); 2341 fl4.flowi4_multipath_hash = 0; 2342 2343 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2344 flkeys = &_flkeys; 2345 } else { 2346 fl4.flowi4_proto = 0; 2347 fl4.fl4_sport = 0; 2348 fl4.fl4_dport = 0; 2349 } 2350 2351 err = fib_lookup(net, &fl4, res, 0); 2352 if (err != 0) { 2353 if (!IN_DEV_FORWARD(in_dev)) 2354 err = -EHOSTUNREACH; 2355 goto no_route; 2356 } 2357 2358 if (res->type == RTN_BROADCAST) { 2359 if (IN_DEV_BFORWARD(in_dev)) 2360 goto make_route; 2361 /* not do cache if bc_forwarding is enabled */ 2362 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2363 do_cache = false; 2364 goto brd_input; 2365 } 2366 2367 err = -EINVAL; 2368 if (res->type == RTN_LOCAL) { 2369 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2370 0, dev, in_dev, &itag); 2371 if (reason) 2372 goto martian_source; 2373 goto local_input; 2374 } 2375 2376 if (!IN_DEV_FORWARD(in_dev)) { 2377 err = -EHOSTUNREACH; 2378 goto no_route; 2379 } 2380 if (res->type != RTN_UNICAST) { 2381 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2382 goto martian_destination; 2383 } 2384 2385 make_route: 2386 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2387 flkeys); 2388 2389 out: 2390 return reason; 2391 2392 brd_input: 2393 if (skb->protocol != htons(ETH_P_IP)) { 2394 reason = SKB_DROP_REASON_INVALID_PROTO; 2395 goto out; 2396 } 2397 2398 if (!ipv4_is_zeronet(saddr)) { 2399 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2400 dev, in_dev, &itag); 2401 if (reason) 2402 goto martian_source; 2403 } 2404 flags |= RTCF_BROADCAST; 2405 res->type = RTN_BROADCAST; 2406 RT_CACHE_STAT_INC(in_brd); 2407 2408 local_input: 2409 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2410 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2411 2412 do_cache &= res->fi && !itag; 2413 if (do_cache) { 2414 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2415 2416 rth = rcu_dereference(nhc->nhc_rth_input); 2417 if (rt_cache_valid(rth)) { 2418 skb_dst_set_noref(skb, &rth->dst); 2419 reason = SKB_NOT_DROPPED_YET; 2420 goto out; 2421 } 2422 } 2423 2424 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2425 flags | RTCF_LOCAL, res->type, false); 2426 if (!rth) 2427 goto e_nobufs; 2428 2429 rth->dst.output= ip_rt_bug; 2430 #ifdef CONFIG_IP_ROUTE_CLASSID 2431 rth->dst.tclassid = itag; 2432 #endif 2433 rth->rt_is_input = 1; 2434 2435 RT_CACHE_STAT_INC(in_slow_tot); 2436 if (res->type == RTN_UNREACHABLE) { 2437 rth->dst.input= ip_error; 2438 rth->dst.error= -err; 2439 rth->rt_flags &= ~RTCF_LOCAL; 2440 } 2441 2442 if (do_cache) { 2443 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2444 2445 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2446 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2447 WARN_ON(rth->dst.input == lwtunnel_input); 2448 rth->dst.lwtstate->orig_input = rth->dst.input; 2449 rth->dst.input = lwtunnel_input; 2450 } 2451 2452 if (unlikely(!rt_cache_route(nhc, rth))) 2453 rt_add_uncached_list(rth); 2454 } 2455 skb_dst_set(skb, &rth->dst); 2456 reason = SKB_NOT_DROPPED_YET; 2457 goto out; 2458 2459 no_route: 2460 RT_CACHE_STAT_INC(in_no_route); 2461 res->type = RTN_UNREACHABLE; 2462 res->fi = NULL; 2463 res->table = NULL; 2464 goto local_input; 2465 2466 /* 2467 * Do not cache martian addresses: they should be logged (RFC1812) 2468 */ 2469 martian_destination: 2470 RT_CACHE_STAT_INC(in_martian_dst); 2471 #ifdef CONFIG_IP_ROUTE_VERBOSE 2472 if (IN_DEV_LOG_MARTIANS(in_dev)) 2473 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2474 &daddr, &saddr, dev->name); 2475 #endif 2476 goto out; 2477 2478 e_nobufs: 2479 reason = SKB_DROP_REASON_NOMEM; 2480 goto out; 2481 2482 martian_source: 2483 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2484 goto out; 2485 } 2486 2487 /* called with rcu_read_lock held */ 2488 static enum skb_drop_reason 2489 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2490 dscp_t dscp, struct net_device *dev, 2491 struct fib_result *res) 2492 { 2493 /* Multicast recognition logic is moved from route cache to here. 2494 * The problem was that too many Ethernet cards have broken/missing 2495 * hardware multicast filters :-( As result the host on multicasting 2496 * network acquires a lot of useless route cache entries, sort of 2497 * SDR messages from all the world. Now we try to get rid of them. 2498 * Really, provided software IP multicast filter is organized 2499 * reasonably (at least, hashed), it does not result in a slowdown 2500 * comparing with route cache reject entries. 2501 * Note, that multicast routers are not affected, because 2502 * route cache entry is created eventually. 2503 */ 2504 if (ipv4_is_multicast(daddr)) { 2505 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2506 struct in_device *in_dev = __in_dev_get_rcu(dev); 2507 int our = 0; 2508 2509 if (!in_dev) 2510 return reason; 2511 2512 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2513 ip_hdr(skb)->protocol); 2514 2515 /* check l3 master if no match yet */ 2516 if (!our && netif_is_l3_slave(dev)) { 2517 struct in_device *l3_in_dev; 2518 2519 l3_in_dev = __in_dev_get_rcu(skb->dev); 2520 if (l3_in_dev) 2521 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2522 ip_hdr(skb)->protocol); 2523 } 2524 2525 if (our 2526 #ifdef CONFIG_IP_MROUTE 2527 || 2528 (!ipv4_is_local_multicast(daddr) && 2529 IN_DEV_MFORWARD(in_dev)) 2530 #endif 2531 ) { 2532 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2533 dev, our); 2534 } 2535 return reason; 2536 } 2537 2538 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2539 } 2540 2541 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2542 __be32 saddr, dscp_t dscp, 2543 struct net_device *dev) 2544 { 2545 enum skb_drop_reason reason; 2546 struct fib_result res; 2547 2548 rcu_read_lock(); 2549 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2550 rcu_read_unlock(); 2551 2552 return reason; 2553 } 2554 EXPORT_SYMBOL(ip_route_input_noref); 2555 2556 /* called with rcu_read_lock() */ 2557 static struct rtable *__mkroute_output(const struct fib_result *res, 2558 const struct flowi4 *fl4, int orig_oif, 2559 struct net_device *dev_out, 2560 unsigned int flags) 2561 { 2562 struct fib_info *fi = res->fi; 2563 struct fib_nh_exception *fnhe; 2564 struct in_device *in_dev; 2565 u16 type = res->type; 2566 struct rtable *rth; 2567 bool do_cache; 2568 2569 in_dev = __in_dev_get_rcu(dev_out); 2570 if (!in_dev) 2571 return ERR_PTR(-EINVAL); 2572 2573 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2574 if (ipv4_is_loopback(fl4->saddr) && 2575 !(dev_out->flags & IFF_LOOPBACK) && 2576 !netif_is_l3_master(dev_out)) 2577 return ERR_PTR(-EINVAL); 2578 2579 if (ipv4_is_lbcast(fl4->daddr)) { 2580 type = RTN_BROADCAST; 2581 2582 /* reset fi to prevent gateway resolution */ 2583 fi = NULL; 2584 } else if (ipv4_is_multicast(fl4->daddr)) { 2585 type = RTN_MULTICAST; 2586 } else if (ipv4_is_zeronet(fl4->daddr)) { 2587 return ERR_PTR(-EINVAL); 2588 } 2589 2590 if (dev_out->flags & IFF_LOOPBACK) 2591 flags |= RTCF_LOCAL; 2592 2593 do_cache = true; 2594 if (type == RTN_BROADCAST) { 2595 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2596 } else if (type == RTN_MULTICAST) { 2597 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2598 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2599 fl4->flowi4_proto)) 2600 flags &= ~RTCF_LOCAL; 2601 else 2602 do_cache = false; 2603 /* If multicast route do not exist use 2604 * default one, but do not gateway in this case. 2605 * Yes, it is hack. 2606 */ 2607 if (fi && res->prefixlen < 4) 2608 fi = NULL; 2609 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2610 (orig_oif != dev_out->ifindex)) { 2611 /* For local routes that require a particular output interface 2612 * we do not want to cache the result. Caching the result 2613 * causes incorrect behaviour when there are multiple source 2614 * addresses on the interface, the end result being that if the 2615 * intended recipient is waiting on that interface for the 2616 * packet he won't receive it because it will be delivered on 2617 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2618 * be set to the loopback interface as well. 2619 */ 2620 do_cache = false; 2621 } 2622 2623 fnhe = NULL; 2624 do_cache &= fi != NULL; 2625 if (fi) { 2626 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2627 struct rtable __rcu **prth; 2628 2629 fnhe = find_exception(nhc, fl4->daddr); 2630 if (!do_cache) 2631 goto add; 2632 if (fnhe) { 2633 prth = &fnhe->fnhe_rth_output; 2634 } else { 2635 if (unlikely(fl4->flowi4_flags & 2636 FLOWI_FLAG_KNOWN_NH && 2637 !(nhc->nhc_gw_family && 2638 nhc->nhc_scope == RT_SCOPE_LINK))) { 2639 do_cache = false; 2640 goto add; 2641 } 2642 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2643 } 2644 rth = rcu_dereference(*prth); 2645 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2646 return rth; 2647 } 2648 2649 add: 2650 rth = rt_dst_alloc(dev_out, flags, type, 2651 IN_DEV_ORCONF(in_dev, NOXFRM)); 2652 if (!rth) 2653 return ERR_PTR(-ENOBUFS); 2654 2655 rth->rt_iif = orig_oif; 2656 2657 RT_CACHE_STAT_INC(out_slow_tot); 2658 2659 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2660 if (flags & RTCF_LOCAL && 2661 !(dev_out->flags & IFF_LOOPBACK)) { 2662 rth->dst.output = ip_mc_output; 2663 RT_CACHE_STAT_INC(out_slow_mc); 2664 } 2665 #ifdef CONFIG_IP_MROUTE 2666 if (type == RTN_MULTICAST) { 2667 if (IN_DEV_MFORWARD(in_dev) && 2668 !ipv4_is_local_multicast(fl4->daddr)) { 2669 rth->dst.input = ip_mr_input; 2670 rth->dst.output = ip_mr_output; 2671 } 2672 } 2673 #endif 2674 } 2675 2676 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2677 lwtunnel_set_redirect(&rth->dst); 2678 2679 return rth; 2680 } 2681 2682 /* 2683 * Major route resolver routine. 2684 */ 2685 2686 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2687 const struct sk_buff *skb) 2688 { 2689 struct fib_result res = { 2690 .type = RTN_UNSPEC, 2691 .fi = NULL, 2692 .table = NULL, 2693 .tclassid = 0, 2694 }; 2695 struct rtable *rth; 2696 2697 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2698 2699 rcu_read_lock(); 2700 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2701 rcu_read_unlock(); 2702 2703 return rth; 2704 } 2705 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2706 2707 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2708 struct fib_result *res, 2709 const struct sk_buff *skb) 2710 { 2711 struct net_device *dev_out = NULL; 2712 int orig_oif = fl4->flowi4_oif; 2713 unsigned int flags = 0; 2714 struct rtable *rth; 2715 int err; 2716 2717 if (fl4->saddr) { 2718 if (ipv4_is_multicast(fl4->saddr) || 2719 ipv4_is_lbcast(fl4->saddr)) { 2720 rth = ERR_PTR(-EINVAL); 2721 goto out; 2722 } 2723 2724 rth = ERR_PTR(-ENETUNREACH); 2725 2726 /* I removed check for oif == dev_out->oif here. 2727 * It was wrong for two reasons: 2728 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2729 * is assigned to multiple interfaces. 2730 * 2. Moreover, we are allowed to send packets with saddr 2731 * of another iface. --ANK 2732 */ 2733 2734 if (fl4->flowi4_oif == 0 && 2735 (ipv4_is_multicast(fl4->daddr) || 2736 ipv4_is_lbcast(fl4->daddr))) { 2737 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2738 dev_out = __ip_dev_find(net, fl4->saddr, false); 2739 if (!dev_out) 2740 goto out; 2741 2742 /* Special hack: user can direct multicasts 2743 * and limited broadcast via necessary interface 2744 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2745 * This hack is not just for fun, it allows 2746 * vic,vat and friends to work. 2747 * They bind socket to loopback, set ttl to zero 2748 * and expect that it will work. 2749 * From the viewpoint of routing cache they are broken, 2750 * because we are not allowed to build multicast path 2751 * with loopback source addr (look, routing cache 2752 * cannot know, that ttl is zero, so that packet 2753 * will not leave this host and route is valid). 2754 * Luckily, this hack is good workaround. 2755 */ 2756 2757 fl4->flowi4_oif = dev_out->ifindex; 2758 goto make_route; 2759 } 2760 2761 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2762 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2763 if (!__ip_dev_find(net, fl4->saddr, false)) 2764 goto out; 2765 } 2766 } 2767 2768 2769 if (fl4->flowi4_oif) { 2770 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2771 rth = ERR_PTR(-ENODEV); 2772 if (!dev_out) 2773 goto out; 2774 2775 /* RACE: Check return value of inet_select_addr instead. */ 2776 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2777 rth = ERR_PTR(-ENETUNREACH); 2778 goto out; 2779 } 2780 if (ipv4_is_local_multicast(fl4->daddr) || 2781 ipv4_is_lbcast(fl4->daddr) || 2782 fl4->flowi4_proto == IPPROTO_IGMP) { 2783 if (!fl4->saddr) 2784 fl4->saddr = inet_select_addr(dev_out, 0, 2785 RT_SCOPE_LINK); 2786 goto make_route; 2787 } 2788 if (!fl4->saddr) { 2789 if (ipv4_is_multicast(fl4->daddr)) 2790 fl4->saddr = inet_select_addr(dev_out, 0, 2791 fl4->flowi4_scope); 2792 else if (!fl4->daddr) 2793 fl4->saddr = inet_select_addr(dev_out, 0, 2794 RT_SCOPE_HOST); 2795 } 2796 } 2797 2798 if (!fl4->daddr) { 2799 fl4->daddr = fl4->saddr; 2800 if (!fl4->daddr) 2801 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2802 dev_out = net->loopback_dev; 2803 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2804 res->type = RTN_LOCAL; 2805 flags |= RTCF_LOCAL; 2806 goto make_route; 2807 } 2808 2809 err = fib_lookup(net, fl4, res, 0); 2810 if (err) { 2811 res->fi = NULL; 2812 res->table = NULL; 2813 if (fl4->flowi4_oif && 2814 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2815 /* Apparently, routing tables are wrong. Assume, 2816 * that the destination is on link. 2817 * 2818 * WHY? DW. 2819 * Because we are allowed to send to iface 2820 * even if it has NO routes and NO assigned 2821 * addresses. When oif is specified, routing 2822 * tables are looked up with only one purpose: 2823 * to catch if destination is gatewayed, rather than 2824 * direct. Moreover, if MSG_DONTROUTE is set, 2825 * we send packet, ignoring both routing tables 2826 * and ifaddr state. --ANK 2827 * 2828 * 2829 * We could make it even if oif is unknown, 2830 * likely IPv6, but we do not. 2831 */ 2832 2833 if (fl4->saddr == 0) 2834 fl4->saddr = inet_select_addr(dev_out, 0, 2835 RT_SCOPE_LINK); 2836 res->type = RTN_UNICAST; 2837 goto make_route; 2838 } 2839 rth = ERR_PTR(err); 2840 goto out; 2841 } 2842 2843 if (res->type == RTN_LOCAL) { 2844 if (!fl4->saddr) { 2845 if (res->fi->fib_prefsrc) 2846 fl4->saddr = res->fi->fib_prefsrc; 2847 else 2848 fl4->saddr = fl4->daddr; 2849 } 2850 2851 /* L3 master device is the loopback for that domain */ 2852 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2853 net->loopback_dev; 2854 2855 /* make sure orig_oif points to fib result device even 2856 * though packet rx/tx happens over loopback or l3mdev 2857 */ 2858 orig_oif = FIB_RES_OIF(*res); 2859 2860 fl4->flowi4_oif = dev_out->ifindex; 2861 flags |= RTCF_LOCAL; 2862 goto make_route; 2863 } 2864 2865 fib_select_path(net, res, fl4, skb); 2866 2867 dev_out = FIB_RES_DEV(*res); 2868 2869 make_route: 2870 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2871 2872 out: 2873 return rth; 2874 } 2875 2876 static struct dst_ops ipv4_dst_blackhole_ops = { 2877 .family = AF_INET, 2878 .default_advmss = ipv4_default_advmss, 2879 .neigh_lookup = ipv4_neigh_lookup, 2880 .check = dst_blackhole_check, 2881 .cow_metrics = dst_blackhole_cow_metrics, 2882 .update_pmtu = dst_blackhole_update_pmtu, 2883 .redirect = dst_blackhole_redirect, 2884 .mtu = dst_blackhole_mtu, 2885 }; 2886 2887 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2888 { 2889 struct rtable *ort = dst_rtable(dst_orig); 2890 struct rtable *rt; 2891 2892 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2893 if (rt) { 2894 struct dst_entry *new = &rt->dst; 2895 2896 new->__use = 1; 2897 new->input = dst_discard; 2898 new->output = dst_discard_out; 2899 2900 new->dev = net->loopback_dev; 2901 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2902 2903 rt->rt_is_input = ort->rt_is_input; 2904 rt->rt_iif = ort->rt_iif; 2905 rt->rt_pmtu = ort->rt_pmtu; 2906 rt->rt_mtu_locked = ort->rt_mtu_locked; 2907 2908 rt->rt_genid = rt_genid_ipv4(net); 2909 rt->rt_flags = ort->rt_flags; 2910 rt->rt_type = ort->rt_type; 2911 rt->rt_uses_gateway = ort->rt_uses_gateway; 2912 rt->rt_gw_family = ort->rt_gw_family; 2913 if (rt->rt_gw_family == AF_INET) 2914 rt->rt_gw4 = ort->rt_gw4; 2915 else if (rt->rt_gw_family == AF_INET6) 2916 rt->rt_gw6 = ort->rt_gw6; 2917 } 2918 2919 dst_release(dst_orig); 2920 2921 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2922 } 2923 2924 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2925 const struct sock *sk) 2926 { 2927 struct rtable *rt = __ip_route_output_key(net, flp4); 2928 2929 if (IS_ERR(rt)) 2930 return rt; 2931 2932 if (flp4->flowi4_proto) { 2933 flp4->flowi4_oif = rt->dst.dev->ifindex; 2934 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2935 flowi4_to_flowi(flp4), 2936 sk, 0)); 2937 } 2938 2939 return rt; 2940 } 2941 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2942 2943 /* called with rcu_read_lock held */ 2944 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2945 struct rtable *rt, u32 table_id, dscp_t dscp, 2946 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2947 u32 seq, unsigned int flags) 2948 { 2949 struct rtmsg *r; 2950 struct nlmsghdr *nlh; 2951 unsigned long expires = 0; 2952 u32 error; 2953 u32 metrics[RTAX_MAX]; 2954 2955 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2956 if (!nlh) 2957 return -EMSGSIZE; 2958 2959 r = nlmsg_data(nlh); 2960 r->rtm_family = AF_INET; 2961 r->rtm_dst_len = 32; 2962 r->rtm_src_len = 0; 2963 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2964 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2965 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2966 goto nla_put_failure; 2967 r->rtm_type = rt->rt_type; 2968 r->rtm_scope = RT_SCOPE_UNIVERSE; 2969 r->rtm_protocol = RTPROT_UNSPEC; 2970 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2971 if (rt->rt_flags & RTCF_NOTIFY) 2972 r->rtm_flags |= RTM_F_NOTIFY; 2973 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2974 r->rtm_flags |= RTCF_DOREDIRECT; 2975 2976 if (nla_put_in_addr(skb, RTA_DST, dst)) 2977 goto nla_put_failure; 2978 if (src) { 2979 r->rtm_src_len = 32; 2980 if (nla_put_in_addr(skb, RTA_SRC, src)) 2981 goto nla_put_failure; 2982 } 2983 if (rt->dst.dev && 2984 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2985 goto nla_put_failure; 2986 if (lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2987 goto nla_put_failure; 2988 #ifdef CONFIG_IP_ROUTE_CLASSID 2989 if (rt->dst.tclassid && 2990 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2991 goto nla_put_failure; 2992 #endif 2993 if (fl4 && !rt_is_input_route(rt) && 2994 fl4->saddr != src) { 2995 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2996 goto nla_put_failure; 2997 } 2998 if (rt->rt_uses_gateway) { 2999 if (rt->rt_gw_family == AF_INET && 3000 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3001 goto nla_put_failure; 3002 } else if (rt->rt_gw_family == AF_INET6) { 3003 int alen = sizeof(struct in6_addr); 3004 struct nlattr *nla; 3005 struct rtvia *via; 3006 3007 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3008 if (!nla) 3009 goto nla_put_failure; 3010 3011 via = nla_data(nla); 3012 via->rtvia_family = AF_INET6; 3013 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3014 } 3015 } 3016 3017 expires = READ_ONCE(rt->dst.expires); 3018 if (expires) { 3019 unsigned long now = jiffies; 3020 3021 if (time_before(now, expires)) 3022 expires -= now; 3023 else 3024 expires = 0; 3025 } 3026 3027 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3028 if (rt->rt_pmtu && expires) 3029 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3030 if (rt->rt_mtu_locked && expires) 3031 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3032 if (rtnetlink_put_metrics(skb, metrics) < 0) 3033 goto nla_put_failure; 3034 3035 if (fl4) { 3036 if (fl4->flowi4_mark && 3037 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3038 goto nla_put_failure; 3039 3040 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3041 nla_put_u32(skb, RTA_UID, 3042 from_kuid_munged(current_user_ns(), 3043 fl4->flowi4_uid))) 3044 goto nla_put_failure; 3045 3046 if (rt_is_input_route(rt)) { 3047 #ifdef CONFIG_IP_MROUTE 3048 if (ipv4_is_multicast(dst) && 3049 !ipv4_is_local_multicast(dst) && 3050 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3051 int err = ipmr_get_route(net, skb, 3052 fl4->saddr, fl4->daddr, 3053 r, portid); 3054 3055 if (err <= 0) { 3056 if (err == 0) 3057 return 0; 3058 goto nla_put_failure; 3059 } 3060 } else 3061 #endif 3062 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3063 goto nla_put_failure; 3064 } 3065 } 3066 3067 error = rt->dst.error; 3068 3069 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3070 goto nla_put_failure; 3071 3072 nlmsg_end(skb, nlh); 3073 return 0; 3074 3075 nla_put_failure: 3076 nlmsg_cancel(skb, nlh); 3077 return -EMSGSIZE; 3078 } 3079 3080 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3081 struct netlink_callback *cb, u32 table_id, 3082 struct fnhe_hash_bucket *bucket, int genid, 3083 int *fa_index, int fa_start, unsigned int flags) 3084 { 3085 int i; 3086 3087 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3088 struct fib_nh_exception *fnhe; 3089 3090 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3091 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3092 struct rtable *rt; 3093 int err; 3094 3095 if (*fa_index < fa_start) 3096 goto next; 3097 3098 if (fnhe->fnhe_genid != genid) 3099 goto next; 3100 3101 if (fnhe->fnhe_expires && 3102 time_after(jiffies, fnhe->fnhe_expires)) 3103 goto next; 3104 3105 rt = rcu_dereference(fnhe->fnhe_rth_input); 3106 if (!rt) 3107 rt = rcu_dereference(fnhe->fnhe_rth_output); 3108 if (!rt) 3109 goto next; 3110 3111 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3112 table_id, 0, NULL, skb, 3113 NETLINK_CB(cb->skb).portid, 3114 cb->nlh->nlmsg_seq, flags); 3115 if (err) 3116 return err; 3117 next: 3118 (*fa_index)++; 3119 } 3120 } 3121 3122 return 0; 3123 } 3124 3125 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3126 u32 table_id, struct fib_info *fi, 3127 int *fa_index, int fa_start, unsigned int flags) 3128 { 3129 struct net *net = sock_net(cb->skb->sk); 3130 int nhsel, genid = fnhe_genid(net); 3131 3132 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3133 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3134 struct fnhe_hash_bucket *bucket; 3135 int err; 3136 3137 if (nhc->nhc_flags & RTNH_F_DEAD) 3138 continue; 3139 3140 rcu_read_lock(); 3141 bucket = rcu_dereference(nhc->nhc_exceptions); 3142 err = 0; 3143 if (bucket) 3144 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3145 genid, fa_index, fa_start, 3146 flags); 3147 rcu_read_unlock(); 3148 if (err) 3149 return err; 3150 } 3151 3152 return 0; 3153 } 3154 3155 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3156 u8 ip_proto, __be16 sport, 3157 __be16 dport) 3158 { 3159 struct sk_buff *skb; 3160 struct iphdr *iph; 3161 3162 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3163 if (!skb) 3164 return NULL; 3165 3166 /* Reserve room for dummy headers, this skb can pass 3167 * through good chunk of routing engine. 3168 */ 3169 skb_reset_mac_header(skb); 3170 skb_reset_network_header(skb); 3171 skb->protocol = htons(ETH_P_IP); 3172 iph = skb_put(skb, sizeof(struct iphdr)); 3173 iph->protocol = ip_proto; 3174 iph->saddr = src; 3175 iph->daddr = dst; 3176 iph->version = 0x4; 3177 iph->frag_off = 0; 3178 iph->ihl = 0x5; 3179 skb_set_transport_header(skb, skb->len); 3180 3181 switch (iph->protocol) { 3182 case IPPROTO_UDP: { 3183 struct udphdr *udph; 3184 3185 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3186 udph->source = sport; 3187 udph->dest = dport; 3188 udph->len = htons(sizeof(struct udphdr)); 3189 udph->check = 0; 3190 break; 3191 } 3192 case IPPROTO_TCP: { 3193 struct tcphdr *tcph; 3194 3195 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3196 tcph->source = sport; 3197 tcph->dest = dport; 3198 tcph->doff = sizeof(struct tcphdr) / 4; 3199 tcph->rst = 1; 3200 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3201 src, dst, 0); 3202 break; 3203 } 3204 case IPPROTO_ICMP: { 3205 struct icmphdr *icmph; 3206 3207 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3208 icmph->type = ICMP_ECHO; 3209 icmph->code = 0; 3210 } 3211 } 3212 3213 return skb; 3214 } 3215 3216 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3217 const struct nlmsghdr *nlh, 3218 struct nlattr **tb, 3219 struct netlink_ext_ack *extack) 3220 { 3221 struct rtmsg *rtm; 3222 int i, err; 3223 3224 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3225 if (!rtm) { 3226 NL_SET_ERR_MSG(extack, 3227 "ipv4: Invalid header for route get request"); 3228 return -EINVAL; 3229 } 3230 3231 if (!netlink_strict_get_check(skb)) 3232 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3233 rtm_ipv4_policy, extack); 3234 3235 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3236 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3237 rtm->rtm_table || rtm->rtm_protocol || 3238 rtm->rtm_scope || rtm->rtm_type) { 3239 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3240 return -EINVAL; 3241 } 3242 3243 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3244 RTM_F_LOOKUP_TABLE | 3245 RTM_F_FIB_MATCH)) { 3246 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3247 return -EINVAL; 3248 } 3249 3250 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3251 rtm_ipv4_policy, extack); 3252 if (err) 3253 return err; 3254 3255 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3256 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3257 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3258 return -EINVAL; 3259 } 3260 3261 for (i = 0; i <= RTA_MAX; i++) { 3262 if (!tb[i]) 3263 continue; 3264 3265 switch (i) { 3266 case RTA_IIF: 3267 case RTA_OIF: 3268 case RTA_SRC: 3269 case RTA_DST: 3270 case RTA_IP_PROTO: 3271 case RTA_SPORT: 3272 case RTA_DPORT: 3273 case RTA_MARK: 3274 case RTA_UID: 3275 break; 3276 default: 3277 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3278 return -EINVAL; 3279 } 3280 } 3281 3282 return 0; 3283 } 3284 3285 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3286 struct netlink_ext_ack *extack) 3287 { 3288 struct net *net = sock_net(in_skb->sk); 3289 struct nlattr *tb[RTA_MAX+1]; 3290 u32 table_id = RT_TABLE_MAIN; 3291 __be16 sport = 0, dport = 0; 3292 struct fib_result res = {}; 3293 u8 ip_proto = IPPROTO_UDP; 3294 struct rtable *rt = NULL; 3295 struct sk_buff *skb; 3296 struct rtmsg *rtm; 3297 struct flowi4 fl4 = {}; 3298 __be32 dst = 0; 3299 __be32 src = 0; 3300 dscp_t dscp; 3301 kuid_t uid; 3302 u32 iif; 3303 int err; 3304 int mark; 3305 3306 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3307 if (err < 0) 3308 return err; 3309 3310 rtm = nlmsg_data(nlh); 3311 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3312 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3313 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3314 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3315 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3316 if (tb[RTA_UID]) 3317 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3318 else 3319 uid = (iif ? INVALID_UID : current_uid()); 3320 3321 if (tb[RTA_IP_PROTO]) { 3322 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3323 &ip_proto, AF_INET, extack); 3324 if (err) 3325 return err; 3326 } 3327 3328 if (tb[RTA_SPORT]) 3329 sport = nla_get_be16(tb[RTA_SPORT]); 3330 3331 if (tb[RTA_DPORT]) 3332 dport = nla_get_be16(tb[RTA_DPORT]); 3333 3334 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3335 if (!skb) 3336 return -ENOBUFS; 3337 3338 fl4.daddr = dst; 3339 fl4.saddr = src; 3340 fl4.flowi4_dscp = dscp; 3341 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3342 fl4.flowi4_mark = mark; 3343 fl4.flowi4_uid = uid; 3344 if (sport) 3345 fl4.fl4_sport = sport; 3346 if (dport) 3347 fl4.fl4_dport = dport; 3348 fl4.flowi4_proto = ip_proto; 3349 3350 rcu_read_lock(); 3351 3352 if (iif) { 3353 struct net_device *dev; 3354 3355 dev = dev_get_by_index_rcu(net, iif); 3356 if (!dev) { 3357 err = -ENODEV; 3358 goto errout_rcu; 3359 } 3360 3361 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3362 skb->dev = dev; 3363 skb->mark = mark; 3364 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3365 &res) ? -EINVAL : 0; 3366 3367 rt = skb_rtable(skb); 3368 if (err == 0 && rt->dst.error) 3369 err = -rt->dst.error; 3370 } else { 3371 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3372 skb->dev = net->loopback_dev; 3373 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3374 err = 0; 3375 if (IS_ERR(rt)) 3376 err = PTR_ERR(rt); 3377 else 3378 skb_dst_set(skb, &rt->dst); 3379 } 3380 3381 if (err) 3382 goto errout_rcu; 3383 3384 if (rtm->rtm_flags & RTM_F_NOTIFY) 3385 rt->rt_flags |= RTCF_NOTIFY; 3386 3387 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3388 table_id = res.table ? res.table->tb_id : 0; 3389 3390 /* reset skb for netlink reply msg */ 3391 skb_trim(skb, 0); 3392 skb_reset_network_header(skb); 3393 skb_reset_transport_header(skb); 3394 skb_reset_mac_header(skb); 3395 3396 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3397 struct fib_rt_info fri; 3398 3399 if (!res.fi) { 3400 err = fib_props[res.type].error; 3401 if (!err) 3402 err = -EHOSTUNREACH; 3403 goto errout_rcu; 3404 } 3405 fri.fi = res.fi; 3406 fri.tb_id = table_id; 3407 fri.dst = res.prefix; 3408 fri.dst_len = res.prefixlen; 3409 fri.dscp = res.dscp; 3410 fri.type = rt->rt_type; 3411 fri.offload = 0; 3412 fri.trap = 0; 3413 fri.offload_failed = 0; 3414 if (res.fa_head) { 3415 struct fib_alias *fa; 3416 3417 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3418 u8 slen = 32 - fri.dst_len; 3419 3420 if (fa->fa_slen == slen && 3421 fa->tb_id == fri.tb_id && 3422 fa->fa_dscp == fri.dscp && 3423 fa->fa_info == res.fi && 3424 fa->fa_type == fri.type) { 3425 fri.offload = READ_ONCE(fa->offload); 3426 fri.trap = READ_ONCE(fa->trap); 3427 fri.offload_failed = 3428 READ_ONCE(fa->offload_failed); 3429 break; 3430 } 3431 } 3432 } 3433 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3434 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3435 } else { 3436 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3437 skb, NETLINK_CB(in_skb).portid, 3438 nlh->nlmsg_seq, 0); 3439 } 3440 if (err < 0) 3441 goto errout_rcu; 3442 3443 rcu_read_unlock(); 3444 3445 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3446 3447 errout_free: 3448 return err; 3449 errout_rcu: 3450 rcu_read_unlock(); 3451 kfree_skb(skb); 3452 goto errout_free; 3453 } 3454 3455 void ip_rt_multicast_event(struct in_device *in_dev) 3456 { 3457 rt_cache_flush(dev_net(in_dev->dev)); 3458 } 3459 3460 #ifdef CONFIG_SYSCTL 3461 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3462 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3463 static int ip_rt_gc_elasticity __read_mostly = 8; 3464 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3465 3466 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3467 void *buffer, size_t *lenp, loff_t *ppos) 3468 { 3469 struct net *net = (struct net *)__ctl->extra1; 3470 3471 if (write) { 3472 rt_cache_flush(net); 3473 fnhe_genid_bump(net); 3474 return 0; 3475 } 3476 3477 return -EINVAL; 3478 } 3479 3480 static struct ctl_table ipv4_route_table[] = { 3481 { 3482 .procname = "gc_thresh", 3483 .data = &ipv4_dst_ops.gc_thresh, 3484 .maxlen = sizeof(int), 3485 .mode = 0644, 3486 .proc_handler = proc_dointvec, 3487 }, 3488 { 3489 .procname = "max_size", 3490 .data = &ip_rt_max_size, 3491 .maxlen = sizeof(int), 3492 .mode = 0644, 3493 .proc_handler = proc_dointvec, 3494 }, 3495 { 3496 /* Deprecated. Use gc_min_interval_ms */ 3497 3498 .procname = "gc_min_interval", 3499 .data = &ip_rt_gc_min_interval, 3500 .maxlen = sizeof(int), 3501 .mode = 0644, 3502 .proc_handler = proc_dointvec_jiffies, 3503 }, 3504 { 3505 .procname = "gc_min_interval_ms", 3506 .data = &ip_rt_gc_min_interval, 3507 .maxlen = sizeof(int), 3508 .mode = 0644, 3509 .proc_handler = proc_dointvec_ms_jiffies, 3510 }, 3511 { 3512 .procname = "gc_timeout", 3513 .data = &ip_rt_gc_timeout, 3514 .maxlen = sizeof(int), 3515 .mode = 0644, 3516 .proc_handler = proc_dointvec_jiffies, 3517 }, 3518 { 3519 .procname = "gc_interval", 3520 .data = &ip_rt_gc_interval, 3521 .maxlen = sizeof(int), 3522 .mode = 0644, 3523 .proc_handler = proc_dointvec_jiffies, 3524 }, 3525 { 3526 .procname = "redirect_load", 3527 .data = &ip_rt_redirect_load, 3528 .maxlen = sizeof(int), 3529 .mode = 0644, 3530 .proc_handler = proc_dointvec, 3531 }, 3532 { 3533 .procname = "redirect_number", 3534 .data = &ip_rt_redirect_number, 3535 .maxlen = sizeof(int), 3536 .mode = 0644, 3537 .proc_handler = proc_dointvec, 3538 }, 3539 { 3540 .procname = "redirect_silence", 3541 .data = &ip_rt_redirect_silence, 3542 .maxlen = sizeof(int), 3543 .mode = 0644, 3544 .proc_handler = proc_dointvec, 3545 }, 3546 { 3547 .procname = "error_cost", 3548 .data = &ip_rt_error_cost, 3549 .maxlen = sizeof(int), 3550 .mode = 0644, 3551 .proc_handler = proc_dointvec, 3552 }, 3553 { 3554 .procname = "error_burst", 3555 .data = &ip_rt_error_burst, 3556 .maxlen = sizeof(int), 3557 .mode = 0644, 3558 .proc_handler = proc_dointvec, 3559 }, 3560 { 3561 .procname = "gc_elasticity", 3562 .data = &ip_rt_gc_elasticity, 3563 .maxlen = sizeof(int), 3564 .mode = 0644, 3565 .proc_handler = proc_dointvec, 3566 }, 3567 }; 3568 3569 static const char ipv4_route_flush_procname[] = "flush"; 3570 3571 static struct ctl_table ipv4_route_netns_table[] = { 3572 { 3573 .procname = ipv4_route_flush_procname, 3574 .maxlen = sizeof(int), 3575 .mode = 0200, 3576 .proc_handler = ipv4_sysctl_rtcache_flush, 3577 }, 3578 { 3579 .procname = "min_pmtu", 3580 .data = &init_net.ipv4.ip_rt_min_pmtu, 3581 .maxlen = sizeof(int), 3582 .mode = 0644, 3583 .proc_handler = proc_dointvec_minmax, 3584 .extra1 = &ip_min_valid_pmtu, 3585 }, 3586 { 3587 .procname = "mtu_expires", 3588 .data = &init_net.ipv4.ip_rt_mtu_expires, 3589 .maxlen = sizeof(int), 3590 .mode = 0644, 3591 .proc_handler = proc_dointvec_jiffies, 3592 }, 3593 { 3594 .procname = "min_adv_mss", 3595 .data = &init_net.ipv4.ip_rt_min_advmss, 3596 .maxlen = sizeof(int), 3597 .mode = 0644, 3598 .proc_handler = proc_dointvec, 3599 }, 3600 }; 3601 3602 static __net_init int sysctl_route_net_init(struct net *net) 3603 { 3604 struct ctl_table *tbl; 3605 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3606 3607 tbl = ipv4_route_netns_table; 3608 if (!net_eq(net, &init_net)) { 3609 int i; 3610 3611 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3612 if (!tbl) 3613 goto err_dup; 3614 3615 /* Don't export non-whitelisted sysctls to unprivileged users */ 3616 if (net->user_ns != &init_user_ns) { 3617 if (tbl[0].procname != ipv4_route_flush_procname) 3618 table_size = 0; 3619 } 3620 3621 /* Update the variables to point into the current struct net 3622 * except for the first element flush 3623 */ 3624 for (i = 1; i < table_size; i++) 3625 tbl[i].data += (void *)net - (void *)&init_net; 3626 } 3627 tbl[0].extra1 = net; 3628 3629 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3630 tbl, table_size); 3631 if (!net->ipv4.route_hdr) 3632 goto err_reg; 3633 return 0; 3634 3635 err_reg: 3636 if (tbl != ipv4_route_netns_table) 3637 kfree(tbl); 3638 err_dup: 3639 return -ENOMEM; 3640 } 3641 3642 static __net_exit void sysctl_route_net_exit(struct net *net) 3643 { 3644 const struct ctl_table *tbl; 3645 3646 tbl = net->ipv4.route_hdr->ctl_table_arg; 3647 unregister_net_sysctl_table(net->ipv4.route_hdr); 3648 BUG_ON(tbl == ipv4_route_netns_table); 3649 kfree(tbl); 3650 } 3651 3652 static __net_initdata struct pernet_operations sysctl_route_ops = { 3653 .init = sysctl_route_net_init, 3654 .exit = sysctl_route_net_exit, 3655 }; 3656 #endif 3657 3658 static __net_init int netns_ip_rt_init(struct net *net) 3659 { 3660 /* Set default value for namespaceified sysctls */ 3661 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3662 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3663 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3664 return 0; 3665 } 3666 3667 static struct pernet_operations __net_initdata ip_rt_ops = { 3668 .init = netns_ip_rt_init, 3669 }; 3670 3671 static __net_init int rt_genid_init(struct net *net) 3672 { 3673 atomic_set(&net->ipv4.rt_genid, 0); 3674 atomic_set(&net->fnhe_genid, 0); 3675 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3676 return 0; 3677 } 3678 3679 static __net_initdata struct pernet_operations rt_genid_ops = { 3680 .init = rt_genid_init, 3681 }; 3682 3683 static int __net_init ipv4_inetpeer_init(struct net *net) 3684 { 3685 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3686 3687 if (!bp) 3688 return -ENOMEM; 3689 inet_peer_base_init(bp); 3690 net->ipv4.peers = bp; 3691 return 0; 3692 } 3693 3694 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3695 { 3696 struct inet_peer_base *bp = net->ipv4.peers; 3697 3698 net->ipv4.peers = NULL; 3699 inetpeer_invalidate_tree(bp); 3700 kfree(bp); 3701 } 3702 3703 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3704 .init = ipv4_inetpeer_init, 3705 .exit = ipv4_inetpeer_exit, 3706 }; 3707 3708 #ifdef CONFIG_IP_ROUTE_CLASSID 3709 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3710 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3711 3712 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3713 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3714 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3715 }; 3716 3717 int __init ip_rt_init(void) 3718 { 3719 void *idents_hash; 3720 int cpu; 3721 3722 /* For modern hosts, this will use 2 MB of memory */ 3723 idents_hash = alloc_large_system_hash("IP idents", 3724 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3725 0, 3726 16, /* one bucket per 64 KB */ 3727 HASH_ZERO, 3728 NULL, 3729 &ip_idents_mask, 3730 2048, 3731 256*1024); 3732 3733 ip_idents = idents_hash; 3734 3735 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3736 3737 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3738 3739 for_each_possible_cpu(cpu) { 3740 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3741 3742 INIT_LIST_HEAD(&ul->head); 3743 spin_lock_init(&ul->lock); 3744 } 3745 #ifdef CONFIG_IP_ROUTE_CLASSID 3746 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3747 if (!ip_rt_acct) 3748 panic("IP: failed to allocate ip_rt_acct\n"); 3749 #endif 3750 3751 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3752 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3753 3754 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3755 3756 if (dst_entries_init(&ipv4_dst_ops) < 0) 3757 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3758 3759 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3760 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3761 3762 ipv4_dst_ops.gc_thresh = ~0; 3763 ip_rt_max_size = INT_MAX; 3764 3765 devinet_init(); 3766 ip_fib_init(); 3767 3768 if (ip_rt_proc_init()) 3769 pr_err("Unable to create route proc files\n"); 3770 #ifdef CONFIG_XFRM 3771 xfrm_init(); 3772 xfrm4_init(); 3773 #endif 3774 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3775 3776 #ifdef CONFIG_SYSCTL 3777 register_pernet_subsys(&sysctl_route_ops); 3778 #endif 3779 register_pernet_subsys(&ip_rt_ops); 3780 register_pernet_subsys(&rt_genid_ops); 3781 register_pernet_subsys(&ipv4_inetpeer_ops); 3782 return 0; 3783 } 3784 3785 #ifdef CONFIG_SYSCTL 3786 /* 3787 * We really need to sanitize the damn ipv4 init order, then all 3788 * this nonsense will go away. 3789 */ 3790 void __init ip_static_sysctl_init(void) 3791 { 3792 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3793 } 3794 #endif 3795