1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/bitops.h> 65 #include <linux/kernel.h> 66 #include <linux/mm.h> 67 #include <linux/memblock.h> 68 #include <linux/socket.h> 69 #include <linux/errno.h> 70 #include <linux/in.h> 71 #include <linux/inet.h> 72 #include <linux/netdevice.h> 73 #include <linux/proc_fs.h> 74 #include <linux/init.h> 75 #include <linux/skbuff.h> 76 #include <linux/inetdevice.h> 77 #include <linux/igmp.h> 78 #include <linux/pkt_sched.h> 79 #include <linux/mroute.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/random.h> 82 #include <linux/rcupdate.h> 83 #include <linux/slab.h> 84 #include <linux/jhash.h> 85 #include <net/dst.h> 86 #include <net/dst_metadata.h> 87 #include <net/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_GC_TIMEOUT (300*HZ) 110 111 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 112 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 113 #define DEFAULT_MIN_ADVMSS 256 114 static int ip_rt_max_size; 115 static int ip_rt_redirect_number __read_mostly = 9; 116 static int ip_rt_redirect_load __read_mostly = HZ / 50; 117 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 118 static int ip_rt_error_cost __read_mostly = HZ; 119 static int ip_rt_error_burst __read_mostly = 5 * HZ; 120 121 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 122 123 /* 124 * Interface to generic destination cache. 125 */ 126 127 INDIRECT_CALLABLE_SCOPE 128 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 129 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 130 INDIRECT_CALLABLE_SCOPE 131 unsigned int ipv4_mtu(const struct dst_entry *dst); 132 static void ipv4_negative_advice(struct sock *sk, 133 struct dst_entry *dst); 134 static void ipv4_link_failure(struct sk_buff *skb); 135 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 136 struct sk_buff *skb, u32 mtu, 137 bool confirm_neigh); 138 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 139 struct sk_buff *skb); 140 static void ipv4_dst_destroy(struct dst_entry *dst); 141 142 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 143 { 144 WARN_ON(1); 145 return NULL; 146 } 147 148 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 149 struct sk_buff *skb, 150 const void *daddr); 151 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 152 153 static struct dst_ops ipv4_dst_ops = { 154 .family = AF_INET, 155 .check = ipv4_dst_check, 156 .default_advmss = ipv4_default_advmss, 157 .mtu = ipv4_mtu, 158 .cow_metrics = ipv4_cow_metrics, 159 .destroy = ipv4_dst_destroy, 160 .negative_advice = ipv4_negative_advice, 161 .link_failure = ipv4_link_failure, 162 .update_pmtu = ip_rt_update_pmtu, 163 .redirect = ip_do_redirect, 164 .local_out = __ip_local_out, 165 .neigh_lookup = ipv4_neigh_lookup, 166 .confirm_neigh = ipv4_confirm_neigh, 167 }; 168 169 #define ECN_OR_COST(class) TC_PRIO_##class 170 171 const __u8 ip_tos2prio[16] = { 172 TC_PRIO_BESTEFFORT, 173 ECN_OR_COST(BESTEFFORT), 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BULK, 177 ECN_OR_COST(BULK), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_INTERACTIVE, 181 ECN_OR_COST(INTERACTIVE), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE_BULK, 185 ECN_OR_COST(INTERACTIVE_BULK), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK) 188 }; 189 EXPORT_SYMBOL(ip_tos2prio); 190 191 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 192 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 193 194 #ifdef CONFIG_PROC_FS 195 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 196 { 197 if (*pos) 198 return NULL; 199 return SEQ_START_TOKEN; 200 } 201 202 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 203 { 204 ++*pos; 205 return NULL; 206 } 207 208 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 209 { 210 } 211 212 static int rt_cache_seq_show(struct seq_file *seq, void *v) 213 { 214 if (v == SEQ_START_TOKEN) 215 seq_printf(seq, "%-127s\n", 216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 218 "HHUptod\tSpecDst"); 219 return 0; 220 } 221 222 static const struct seq_operations rt_cache_seq_ops = { 223 .start = rt_cache_seq_start, 224 .next = rt_cache_seq_next, 225 .stop = rt_cache_seq_stop, 226 .show = rt_cache_seq_show, 227 }; 228 229 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 230 { 231 int cpu; 232 233 if (*pos == 0) 234 return SEQ_START_TOKEN; 235 236 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 237 if (!cpu_possible(cpu)) 238 continue; 239 *pos = cpu+1; 240 return &per_cpu(rt_cache_stat, cpu); 241 } 242 return NULL; 243 } 244 245 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 246 { 247 int cpu; 248 249 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 250 if (!cpu_possible(cpu)) 251 continue; 252 *pos = cpu+1; 253 return &per_cpu(rt_cache_stat, cpu); 254 } 255 (*pos)++; 256 return NULL; 257 258 } 259 260 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 261 { 262 263 } 264 265 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 266 { 267 struct rt_cache_stat *st = v; 268 269 if (v == SEQ_START_TOKEN) { 270 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"); 271 return 0; 272 } 273 274 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 275 "%08x %08x %08x %08x %08x %08x " 276 "%08x %08x %08x %08x\n", 277 dst_entries_get_slow(&ipv4_dst_ops), 278 0, /* st->in_hit */ 279 st->in_slow_tot, 280 st->in_slow_mc, 281 st->in_no_route, 282 st->in_brd, 283 st->in_martian_dst, 284 st->in_martian_src, 285 286 0, /* st->out_hit */ 287 st->out_slow_tot, 288 st->out_slow_mc, 289 290 0, /* st->gc_total */ 291 0, /* st->gc_ignored */ 292 0, /* st->gc_goal_miss */ 293 0, /* st->gc_dst_overflow */ 294 0, /* st->in_hlist_search */ 295 0 /* st->out_hlist_search */ 296 ); 297 return 0; 298 } 299 300 static const struct seq_operations rt_cpu_seq_ops = { 301 .start = rt_cpu_seq_start, 302 .next = rt_cpu_seq_next, 303 .stop = rt_cpu_seq_stop, 304 .show = rt_cpu_seq_show, 305 }; 306 307 #ifdef CONFIG_IP_ROUTE_CLASSID 308 static int rt_acct_proc_show(struct seq_file *m, void *v) 309 { 310 struct ip_rt_acct *dst, *src; 311 unsigned int i, j; 312 313 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 314 if (!dst) 315 return -ENOMEM; 316 317 for_each_possible_cpu(i) { 318 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 319 for (j = 0; j < 256; j++) { 320 dst[j].o_bytes += src[j].o_bytes; 321 dst[j].o_packets += src[j].o_packets; 322 dst[j].i_bytes += src[j].i_bytes; 323 dst[j].i_packets += src[j].i_packets; 324 } 325 } 326 327 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 328 kfree(dst); 329 return 0; 330 } 331 #endif 332 333 static int __net_init ip_rt_do_proc_init(struct net *net) 334 { 335 struct proc_dir_entry *pde; 336 337 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 338 &rt_cache_seq_ops); 339 if (!pde) 340 goto err1; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 343 &rt_cpu_seq_ops); 344 if (!pde) 345 goto err2; 346 347 #ifdef CONFIG_IP_ROUTE_CLASSID 348 pde = proc_create_single("rt_acct", 0, net->proc_net, 349 rt_acct_proc_show); 350 if (!pde) 351 goto err3; 352 #endif 353 return 0; 354 355 #ifdef CONFIG_IP_ROUTE_CLASSID 356 err3: 357 remove_proc_entry("rt_cache", net->proc_net_stat); 358 #endif 359 err2: 360 remove_proc_entry("rt_cache", net->proc_net); 361 err1: 362 return -ENOMEM; 363 } 364 365 static void __net_exit ip_rt_do_proc_exit(struct net *net) 366 { 367 remove_proc_entry("rt_cache", net->proc_net_stat); 368 remove_proc_entry("rt_cache", net->proc_net); 369 #ifdef CONFIG_IP_ROUTE_CLASSID 370 remove_proc_entry("rt_acct", net->proc_net); 371 #endif 372 } 373 374 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 375 .init = ip_rt_do_proc_init, 376 .exit = ip_rt_do_proc_exit, 377 }; 378 379 static int __init ip_rt_proc_init(void) 380 { 381 return register_pernet_subsys(&ip_rt_proc_ops); 382 } 383 384 #else 385 static inline int ip_rt_proc_init(void) 386 { 387 return 0; 388 } 389 #endif /* CONFIG_PROC_FS */ 390 391 static inline bool rt_is_expired(const struct rtable *rth) 392 { 393 bool res; 394 395 rcu_read_lock(); 396 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev)); 397 rcu_read_unlock(); 398 399 return res; 400 } 401 402 void rt_cache_flush(struct net *net) 403 { 404 rt_genid_bump_ipv4(net); 405 } 406 407 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 408 struct sk_buff *skb, 409 const void *daddr) 410 { 411 const struct rtable *rt = container_of(dst, struct rtable, dst); 412 struct net_device *dev = dst->dev; 413 struct neighbour *n; 414 415 rcu_read_lock(); 416 417 if (likely(rt->rt_gw_family == AF_INET)) { 418 n = ip_neigh_gw4(dev, rt->rt_gw4); 419 } else if (rt->rt_gw_family == AF_INET6) { 420 n = ip_neigh_gw6(dev, &rt->rt_gw6); 421 } else { 422 __be32 pkey; 423 424 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 425 n = ip_neigh_gw4(dev, pkey); 426 } 427 428 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 429 n = NULL; 430 431 rcu_read_unlock(); 432 433 return n; 434 } 435 436 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 437 { 438 const struct rtable *rt = container_of(dst, struct rtable, dst); 439 struct net_device *dev = dst->dev; 440 const __be32 *pkey = daddr; 441 442 if (rt->rt_gw_family == AF_INET) { 443 pkey = (const __be32 *)&rt->rt_gw4; 444 } else if (rt->rt_gw_family == AF_INET6) { 445 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 446 } else if (!daddr || 447 (rt->rt_flags & 448 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 449 return; 450 } 451 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 452 } 453 454 /* Hash tables of size 2048..262144 depending on RAM size. 455 * Each bucket uses 8 bytes. 456 */ 457 static u32 ip_idents_mask __read_mostly; 458 static atomic_t *ip_idents __read_mostly; 459 static u32 *ip_tstamps __read_mostly; 460 461 /* In order to protect privacy, we add a perturbation to identifiers 462 * if one generator is seldom used. This makes hard for an attacker 463 * to infer how many packets were sent between two points in time. 464 */ 465 static u32 ip_idents_reserve(u32 hash, int segs) 466 { 467 u32 bucket, old, now = (u32)jiffies; 468 atomic_t *p_id; 469 u32 *p_tstamp; 470 u32 delta = 0; 471 472 bucket = hash & ip_idents_mask; 473 p_tstamp = ip_tstamps + bucket; 474 p_id = ip_idents + bucket; 475 old = READ_ONCE(*p_tstamp); 476 477 if (old != now && cmpxchg(p_tstamp, old, now) == old) 478 delta = get_random_u32_below(now - old); 479 480 /* If UBSAN reports an error there, please make sure your compiler 481 * supports -fno-strict-overflow before reporting it that was a bug 482 * in UBSAN, and it has been fixed in GCC-8. 483 */ 484 return atomic_add_return(segs + delta, p_id) - segs; 485 } 486 487 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 488 { 489 u32 hash, id; 490 491 /* Note the following code is not safe, but this is okay. */ 492 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 493 get_random_bytes(&net->ipv4.ip_id_key, 494 sizeof(net->ipv4.ip_id_key)); 495 496 hash = siphash_3u32((__force u32)iph->daddr, 497 (__force u32)iph->saddr, 498 iph->protocol, 499 &net->ipv4.ip_id_key); 500 id = ip_idents_reserve(hash, segs); 501 iph->id = htons(id); 502 } 503 EXPORT_SYMBOL(__ip_select_ident); 504 505 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 506 const struct sock *sk, const struct iphdr *iph, 507 int oif, __u8 tos, u8 prot, u32 mark, 508 int flow_flags) 509 { 510 __u8 scope = RT_SCOPE_UNIVERSE; 511 512 if (sk) { 513 oif = sk->sk_bound_dev_if; 514 mark = READ_ONCE(sk->sk_mark); 515 tos = ip_sock_rt_tos(sk); 516 scope = ip_sock_rt_scope(sk); 517 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 518 sk->sk_protocol; 519 } 520 521 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope, 522 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 523 sock_net_uid(net, sk)); 524 } 525 526 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 527 const struct sock *sk) 528 { 529 const struct net *net = dev_net(skb->dev); 530 const struct iphdr *iph = ip_hdr(skb); 531 int oif = skb->dev->ifindex; 532 u8 prot = iph->protocol; 533 u32 mark = skb->mark; 534 __u8 tos = iph->tos; 535 536 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 537 } 538 539 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 540 { 541 const struct inet_sock *inet = inet_sk(sk); 542 const struct ip_options_rcu *inet_opt; 543 __be32 daddr = inet->inet_daddr; 544 545 rcu_read_lock(); 546 inet_opt = rcu_dereference(inet->inet_opt); 547 if (inet_opt && inet_opt->opt.srr) 548 daddr = inet_opt->opt.faddr; 549 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 550 ip_sock_rt_tos(sk), 551 ip_sock_rt_scope(sk), 552 inet_test_bit(HDRINCL, sk) ? 553 IPPROTO_RAW : sk->sk_protocol, 554 inet_sk_flowi_flags(sk), 555 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 556 rcu_read_unlock(); 557 } 558 559 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 560 const struct sk_buff *skb) 561 { 562 if (skb) 563 build_skb_flow_key(fl4, skb, sk); 564 else 565 build_sk_flow_key(fl4, sk); 566 } 567 568 static DEFINE_SPINLOCK(fnhe_lock); 569 570 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 571 { 572 struct rtable *rt; 573 574 rt = rcu_dereference(fnhe->fnhe_rth_input); 575 if (rt) { 576 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 577 dst_dev_put(&rt->dst); 578 dst_release(&rt->dst); 579 } 580 rt = rcu_dereference(fnhe->fnhe_rth_output); 581 if (rt) { 582 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 583 dst_dev_put(&rt->dst); 584 dst_release(&rt->dst); 585 } 586 } 587 588 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 589 { 590 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 591 struct fib_nh_exception *fnhe, *oldest = NULL; 592 593 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 594 fnhe = rcu_dereference_protected(*fnhe_p, 595 lockdep_is_held(&fnhe_lock)); 596 if (!fnhe) 597 break; 598 if (!oldest || 599 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 600 oldest = fnhe; 601 oldest_p = fnhe_p; 602 } 603 } 604 fnhe_flush_routes(oldest); 605 *oldest_p = oldest->fnhe_next; 606 kfree_rcu(oldest, rcu); 607 } 608 609 static u32 fnhe_hashfun(__be32 daddr) 610 { 611 static siphash_aligned_key_t fnhe_hash_key; 612 u64 hval; 613 614 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 615 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 616 return hash_64(hval, FNHE_HASH_SHIFT); 617 } 618 619 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 620 { 621 rt->rt_pmtu = fnhe->fnhe_pmtu; 622 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 623 rt->dst.expires = fnhe->fnhe_expires; 624 625 if (fnhe->fnhe_gw) { 626 rt->rt_flags |= RTCF_REDIRECTED; 627 rt->rt_uses_gateway = 1; 628 rt->rt_gw_family = AF_INET; 629 rt->rt_gw4 = fnhe->fnhe_gw; 630 } 631 } 632 633 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 634 __be32 gw, u32 pmtu, bool lock, 635 unsigned long expires) 636 { 637 struct fnhe_hash_bucket *hash; 638 struct fib_nh_exception *fnhe; 639 struct rtable *rt; 640 u32 genid, hval; 641 unsigned int i; 642 int depth; 643 644 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 645 hval = fnhe_hashfun(daddr); 646 647 spin_lock_bh(&fnhe_lock); 648 649 hash = rcu_dereference(nhc->nhc_exceptions); 650 if (!hash) { 651 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 652 if (!hash) 653 goto out_unlock; 654 rcu_assign_pointer(nhc->nhc_exceptions, hash); 655 } 656 657 hash += hval; 658 659 depth = 0; 660 for (fnhe = rcu_dereference(hash->chain); fnhe; 661 fnhe = rcu_dereference(fnhe->fnhe_next)) { 662 if (fnhe->fnhe_daddr == daddr) 663 break; 664 depth++; 665 } 666 667 if (fnhe) { 668 if (fnhe->fnhe_genid != genid) 669 fnhe->fnhe_genid = genid; 670 if (gw) 671 fnhe->fnhe_gw = gw; 672 if (pmtu) { 673 fnhe->fnhe_pmtu = pmtu; 674 fnhe->fnhe_mtu_locked = lock; 675 } 676 fnhe->fnhe_expires = max(1UL, expires); 677 /* Update all cached dsts too */ 678 rt = rcu_dereference(fnhe->fnhe_rth_input); 679 if (rt) 680 fill_route_from_fnhe(rt, fnhe); 681 rt = rcu_dereference(fnhe->fnhe_rth_output); 682 if (rt) 683 fill_route_from_fnhe(rt, fnhe); 684 } else { 685 /* Randomize max depth to avoid some side channels attacks. */ 686 int max_depth = FNHE_RECLAIM_DEPTH + 687 get_random_u32_below(FNHE_RECLAIM_DEPTH); 688 689 while (depth > max_depth) { 690 fnhe_remove_oldest(hash); 691 depth--; 692 } 693 694 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 695 if (!fnhe) 696 goto out_unlock; 697 698 fnhe->fnhe_next = hash->chain; 699 700 fnhe->fnhe_genid = genid; 701 fnhe->fnhe_daddr = daddr; 702 fnhe->fnhe_gw = gw; 703 fnhe->fnhe_pmtu = pmtu; 704 fnhe->fnhe_mtu_locked = lock; 705 fnhe->fnhe_expires = max(1UL, expires); 706 707 rcu_assign_pointer(hash->chain, fnhe); 708 709 /* Exception created; mark the cached routes for the nexthop 710 * stale, so anyone caching it rechecks if this exception 711 * applies to them. 712 */ 713 rt = rcu_dereference(nhc->nhc_rth_input); 714 if (rt) 715 rt->dst.obsolete = DST_OBSOLETE_KILL; 716 717 for_each_possible_cpu(i) { 718 struct rtable __rcu **prt; 719 720 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 721 rt = rcu_dereference(*prt); 722 if (rt) 723 rt->dst.obsolete = DST_OBSOLETE_KILL; 724 } 725 } 726 727 fnhe->fnhe_stamp = jiffies; 728 729 out_unlock: 730 spin_unlock_bh(&fnhe_lock); 731 } 732 733 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 734 bool kill_route) 735 { 736 __be32 new_gw = icmp_hdr(skb)->un.gateway; 737 __be32 old_gw = ip_hdr(skb)->saddr; 738 struct net_device *dev = skb->dev; 739 struct in_device *in_dev; 740 struct fib_result res; 741 struct neighbour *n; 742 struct net *net; 743 744 switch (icmp_hdr(skb)->code & 7) { 745 case ICMP_REDIR_NET: 746 case ICMP_REDIR_NETTOS: 747 case ICMP_REDIR_HOST: 748 case ICMP_REDIR_HOSTTOS: 749 break; 750 751 default: 752 return; 753 } 754 755 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 756 return; 757 758 in_dev = __in_dev_get_rcu(dev); 759 if (!in_dev) 760 return; 761 762 net = dev_net(dev); 763 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 764 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 765 ipv4_is_zeronet(new_gw)) 766 goto reject_redirect; 767 768 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 769 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 770 goto reject_redirect; 771 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 772 goto reject_redirect; 773 } else { 774 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 775 goto reject_redirect; 776 } 777 778 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 779 if (!n) 780 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 781 if (!IS_ERR(n)) { 782 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 783 neigh_event_send(n, NULL); 784 } else { 785 if (fib_lookup(net, fl4, &res, 0) == 0) { 786 struct fib_nh_common *nhc; 787 788 fib_select_path(net, &res, fl4, skb); 789 nhc = FIB_RES_NHC(res); 790 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 791 0, false, 792 jiffies + ip_rt_gc_timeout); 793 } 794 if (kill_route) 795 rt->dst.obsolete = DST_OBSOLETE_KILL; 796 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 797 } 798 neigh_release(n); 799 } 800 return; 801 802 reject_redirect: 803 #ifdef CONFIG_IP_ROUTE_VERBOSE 804 if (IN_DEV_LOG_MARTIANS(in_dev)) { 805 const struct iphdr *iph = (const struct iphdr *) skb->data; 806 __be32 daddr = iph->daddr; 807 __be32 saddr = iph->saddr; 808 809 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 810 " Advised path = %pI4 -> %pI4\n", 811 &old_gw, dev->name, &new_gw, 812 &saddr, &daddr); 813 } 814 #endif 815 ; 816 } 817 818 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 819 { 820 struct rtable *rt; 821 struct flowi4 fl4; 822 const struct iphdr *iph = (const struct iphdr *) skb->data; 823 struct net *net = dev_net(skb->dev); 824 int oif = skb->dev->ifindex; 825 u8 prot = iph->protocol; 826 u32 mark = skb->mark; 827 __u8 tos = iph->tos; 828 829 rt = dst_rtable(dst); 830 831 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 832 __ip_do_redirect(rt, skb, &fl4, true); 833 } 834 835 static void ipv4_negative_advice(struct sock *sk, 836 struct dst_entry *dst) 837 { 838 struct rtable *rt = dst_rtable(dst); 839 840 if ((dst->obsolete > 0) || 841 (rt->rt_flags & RTCF_REDIRECTED) || 842 rt->dst.expires) 843 sk_dst_reset(sk); 844 } 845 846 /* 847 * Algorithm: 848 * 1. The first ip_rt_redirect_number redirects are sent 849 * with exponential backoff, then we stop sending them at all, 850 * assuming that the host ignores our redirects. 851 * 2. If we did not see packets requiring redirects 852 * during ip_rt_redirect_silence, we assume that the host 853 * forgot redirected route and start to send redirects again. 854 * 855 * This algorithm is much cheaper and more intelligent than dumb load limiting 856 * in icmp.c. 857 * 858 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 859 * and "frag. need" (breaks PMTU discovery) in icmp.c. 860 */ 861 862 void ip_rt_send_redirect(struct sk_buff *skb) 863 { 864 struct rtable *rt = skb_rtable(skb); 865 struct in_device *in_dev; 866 struct inet_peer *peer; 867 struct net *net; 868 int log_martians; 869 int vif; 870 871 rcu_read_lock(); 872 in_dev = __in_dev_get_rcu(rt->dst.dev); 873 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 874 rcu_read_unlock(); 875 return; 876 } 877 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 878 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 879 880 net = dev_net(rt->dst.dev); 881 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 882 if (!peer) { 883 rcu_read_unlock(); 884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 885 rt_nexthop(rt, ip_hdr(skb)->daddr)); 886 return; 887 } 888 889 /* No redirected packets during ip_rt_redirect_silence; 890 * reset the algorithm. 891 */ 892 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 893 peer->rate_tokens = 0; 894 peer->n_redirects = 0; 895 } 896 897 /* Too many ignored redirects; do not send anything 898 * set dst.rate_last to the last seen redirected packet. 899 */ 900 if (peer->n_redirects >= ip_rt_redirect_number) { 901 peer->rate_last = jiffies; 902 goto out_unlock; 903 } 904 905 /* Check for load limit; set rate_last to the latest sent 906 * redirect. 907 */ 908 if (peer->n_redirects == 0 || 909 time_after(jiffies, 910 (peer->rate_last + 911 (ip_rt_redirect_load << peer->n_redirects)))) { 912 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 913 914 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 915 peer->rate_last = jiffies; 916 ++peer->n_redirects; 917 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 918 peer->n_redirects == ip_rt_redirect_number) 919 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 920 &ip_hdr(skb)->saddr, inet_iif(skb), 921 &ip_hdr(skb)->daddr, &gw); 922 } 923 out_unlock: 924 rcu_read_unlock(); 925 } 926 927 static int ip_error(struct sk_buff *skb) 928 { 929 struct rtable *rt = skb_rtable(skb); 930 struct net_device *dev = skb->dev; 931 struct in_device *in_dev; 932 struct inet_peer *peer; 933 unsigned long now; 934 struct net *net; 935 SKB_DR(reason); 936 bool send; 937 int code; 938 939 if (netif_is_l3_master(skb->dev)) { 940 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 941 if (!dev) 942 goto out; 943 } 944 945 in_dev = __in_dev_get_rcu(dev); 946 947 /* IP on this device is disabled. */ 948 if (!in_dev) 949 goto out; 950 951 net = dev_net(rt->dst.dev); 952 if (!IN_DEV_FORWARD(in_dev)) { 953 switch (rt->dst.error) { 954 case EHOSTUNREACH: 955 SKB_DR_SET(reason, IP_INADDRERRORS); 956 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 957 break; 958 959 case ENETUNREACH: 960 SKB_DR_SET(reason, IP_INNOROUTES); 961 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 962 break; 963 } 964 goto out; 965 } 966 967 switch (rt->dst.error) { 968 case EINVAL: 969 default: 970 goto out; 971 case EHOSTUNREACH: 972 code = ICMP_HOST_UNREACH; 973 break; 974 case ENETUNREACH: 975 code = ICMP_NET_UNREACH; 976 SKB_DR_SET(reason, IP_INNOROUTES); 977 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 978 break; 979 case EACCES: 980 code = ICMP_PKT_FILTERED; 981 break; 982 } 983 984 rcu_read_lock(); 985 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 986 l3mdev_master_ifindex_rcu(skb->dev)); 987 send = true; 988 if (peer) { 989 now = jiffies; 990 peer->rate_tokens += now - peer->rate_last; 991 if (peer->rate_tokens > ip_rt_error_burst) 992 peer->rate_tokens = ip_rt_error_burst; 993 peer->rate_last = now; 994 if (peer->rate_tokens >= ip_rt_error_cost) 995 peer->rate_tokens -= ip_rt_error_cost; 996 else 997 send = false; 998 } 999 rcu_read_unlock(); 1000 1001 if (send) 1002 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1003 1004 out: kfree_skb_reason(skb, reason); 1005 return 0; 1006 } 1007 1008 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1009 { 1010 struct dst_entry *dst = &rt->dst; 1011 struct fib_result res; 1012 bool lock = false; 1013 struct net *net; 1014 u32 old_mtu; 1015 1016 if (ip_mtu_locked(dst)) 1017 return; 1018 1019 old_mtu = ipv4_mtu(dst); 1020 if (old_mtu < mtu) 1021 return; 1022 1023 rcu_read_lock(); 1024 net = dev_net_rcu(dst->dev); 1025 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1026 lock = true; 1027 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1028 } 1029 1030 if (rt->rt_pmtu == mtu && !lock && 1031 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1032 goto out; 1033 1034 if (fib_lookup(net, fl4, &res, 0) == 0) { 1035 struct fib_nh_common *nhc; 1036 1037 fib_select_path(net, &res, fl4, NULL); 1038 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1039 if (fib_info_num_path(res.fi) > 1) { 1040 int nhsel; 1041 1042 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1043 nhc = fib_info_nhc(res.fi, nhsel); 1044 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1045 jiffies + net->ipv4.ip_rt_mtu_expires); 1046 } 1047 goto out; 1048 } 1049 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1050 nhc = FIB_RES_NHC(res); 1051 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1052 jiffies + net->ipv4.ip_rt_mtu_expires); 1053 } 1054 out: 1055 rcu_read_unlock(); 1056 } 1057 1058 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1059 struct sk_buff *skb, u32 mtu, 1060 bool confirm_neigh) 1061 { 1062 struct rtable *rt = dst_rtable(dst); 1063 struct flowi4 fl4; 1064 1065 ip_rt_build_flow_key(&fl4, sk, skb); 1066 1067 /* Don't make lookup fail for bridged encapsulations */ 1068 if (skb && netif_is_any_bridge_port(skb->dev)) 1069 fl4.flowi4_oif = 0; 1070 1071 __ip_rt_update_pmtu(rt, &fl4, mtu); 1072 } 1073 1074 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1075 int oif, u8 protocol) 1076 { 1077 const struct iphdr *iph = (const struct iphdr *)skb->data; 1078 struct flowi4 fl4; 1079 struct rtable *rt; 1080 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1081 1082 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1083 0); 1084 rt = __ip_route_output_key(net, &fl4); 1085 if (!IS_ERR(rt)) { 1086 __ip_rt_update_pmtu(rt, &fl4, mtu); 1087 ip_rt_put(rt); 1088 } 1089 } 1090 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1091 1092 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1093 { 1094 const struct iphdr *iph = (const struct iphdr *)skb->data; 1095 struct flowi4 fl4; 1096 struct rtable *rt; 1097 1098 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1099 1100 if (!fl4.flowi4_mark) 1101 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1102 1103 rt = __ip_route_output_key(sock_net(sk), &fl4); 1104 if (!IS_ERR(rt)) { 1105 __ip_rt_update_pmtu(rt, &fl4, mtu); 1106 ip_rt_put(rt); 1107 } 1108 } 1109 1110 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1111 { 1112 const struct iphdr *iph = (const struct iphdr *)skb->data; 1113 struct flowi4 fl4; 1114 struct rtable *rt; 1115 struct dst_entry *odst = NULL; 1116 bool new = false; 1117 struct net *net = sock_net(sk); 1118 1119 bh_lock_sock(sk); 1120 1121 if (!ip_sk_accept_pmtu(sk)) 1122 goto out; 1123 1124 odst = sk_dst_get(sk); 1125 1126 if (sock_owned_by_user(sk) || !odst) { 1127 __ipv4_sk_update_pmtu(skb, sk, mtu); 1128 goto out; 1129 } 1130 1131 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1132 1133 rt = dst_rtable(odst); 1134 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1135 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1136 if (IS_ERR(rt)) 1137 goto out; 1138 1139 new = true; 1140 } 1141 1142 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1143 1144 if (!dst_check(&rt->dst, 0)) { 1145 if (new) 1146 dst_release(&rt->dst); 1147 1148 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1149 if (IS_ERR(rt)) 1150 goto out; 1151 1152 new = true; 1153 } 1154 1155 if (new) 1156 sk_dst_set(sk, &rt->dst); 1157 1158 out: 1159 bh_unlock_sock(sk); 1160 dst_release(odst); 1161 } 1162 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1163 1164 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1165 int oif, u8 protocol) 1166 { 1167 const struct iphdr *iph = (const struct iphdr *)skb->data; 1168 struct flowi4 fl4; 1169 struct rtable *rt; 1170 1171 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1172 rt = __ip_route_output_key(net, &fl4); 1173 if (!IS_ERR(rt)) { 1174 __ip_do_redirect(rt, skb, &fl4, false); 1175 ip_rt_put(rt); 1176 } 1177 } 1178 EXPORT_SYMBOL_GPL(ipv4_redirect); 1179 1180 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1181 { 1182 const struct iphdr *iph = (const struct iphdr *)skb->data; 1183 struct flowi4 fl4; 1184 struct rtable *rt; 1185 struct net *net = sock_net(sk); 1186 1187 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1188 rt = __ip_route_output_key(net, &fl4); 1189 if (!IS_ERR(rt)) { 1190 __ip_do_redirect(rt, skb, &fl4, false); 1191 ip_rt_put(rt); 1192 } 1193 } 1194 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1195 1196 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1197 u32 cookie) 1198 { 1199 struct rtable *rt = dst_rtable(dst); 1200 1201 /* All IPV4 dsts are created with ->obsolete set to the value 1202 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1203 * into this function always. 1204 * 1205 * When a PMTU/redirect information update invalidates a route, 1206 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1207 * DST_OBSOLETE_DEAD. 1208 */ 1209 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1210 return NULL; 1211 return dst; 1212 } 1213 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1214 1215 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1216 { 1217 struct net_device *dev; 1218 struct ip_options opt; 1219 int res; 1220 1221 /* Recompile ip options since IPCB may not be valid anymore. 1222 * Also check we have a reasonable ipv4 header. 1223 */ 1224 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1225 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1226 return; 1227 1228 memset(&opt, 0, sizeof(opt)); 1229 if (ip_hdr(skb)->ihl > 5) { 1230 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1231 return; 1232 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1233 1234 rcu_read_lock(); 1235 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1236 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); 1237 rcu_read_unlock(); 1238 1239 if (res) 1240 return; 1241 } 1242 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1243 } 1244 1245 static void ipv4_link_failure(struct sk_buff *skb) 1246 { 1247 struct rtable *rt; 1248 1249 ipv4_send_dest_unreach(skb); 1250 1251 rt = skb_rtable(skb); 1252 if (rt) 1253 dst_set_expires(&rt->dst, 0); 1254 } 1255 1256 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1257 { 1258 pr_debug("%s: %pI4 -> %pI4, %s\n", 1259 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1260 skb->dev ? skb->dev->name : "?"); 1261 kfree_skb(skb); 1262 WARN_ON(1); 1263 return 0; 1264 } 1265 1266 /* 1267 * We do not cache source address of outgoing interface, 1268 * because it is used only by IP RR, TS and SRR options, 1269 * so that it out of fast path. 1270 * 1271 * BTW remember: "addr" is allowed to be not aligned 1272 * in IP options! 1273 */ 1274 1275 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1276 { 1277 __be32 src; 1278 1279 if (rt_is_output_route(rt)) 1280 src = ip_hdr(skb)->saddr; 1281 else { 1282 struct fib_result res; 1283 struct iphdr *iph = ip_hdr(skb); 1284 struct flowi4 fl4 = { 1285 .daddr = iph->daddr, 1286 .saddr = iph->saddr, 1287 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)), 1288 .flowi4_oif = rt->dst.dev->ifindex, 1289 .flowi4_iif = skb->dev->ifindex, 1290 .flowi4_mark = skb->mark, 1291 }; 1292 1293 rcu_read_lock(); 1294 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1295 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1296 else 1297 src = inet_select_addr(rt->dst.dev, 1298 rt_nexthop(rt, iph->daddr), 1299 RT_SCOPE_UNIVERSE); 1300 rcu_read_unlock(); 1301 } 1302 memcpy(addr, &src, 4); 1303 } 1304 1305 #ifdef CONFIG_IP_ROUTE_CLASSID 1306 static void set_class_tag(struct rtable *rt, u32 tag) 1307 { 1308 if (!(rt->dst.tclassid & 0xFFFF)) 1309 rt->dst.tclassid |= tag & 0xFFFF; 1310 if (!(rt->dst.tclassid & 0xFFFF0000)) 1311 rt->dst.tclassid |= tag & 0xFFFF0000; 1312 } 1313 #endif 1314 1315 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1316 { 1317 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1318 unsigned int advmss; 1319 struct net *net; 1320 1321 rcu_read_lock(); 1322 net = dev_net_rcu(dst->dev); 1323 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1324 net->ipv4.ip_rt_min_advmss); 1325 rcu_read_unlock(); 1326 1327 return min(advmss, IPV4_MAX_PMTU - header_size); 1328 } 1329 1330 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1331 { 1332 return ip_dst_mtu_maybe_forward(dst, false); 1333 } 1334 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1335 1336 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1337 { 1338 struct fnhe_hash_bucket *hash; 1339 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1340 u32 hval = fnhe_hashfun(daddr); 1341 1342 spin_lock_bh(&fnhe_lock); 1343 1344 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1345 lockdep_is_held(&fnhe_lock)); 1346 hash += hval; 1347 1348 fnhe_p = &hash->chain; 1349 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1350 while (fnhe) { 1351 if (fnhe->fnhe_daddr == daddr) { 1352 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1353 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1354 /* set fnhe_daddr to 0 to ensure it won't bind with 1355 * new dsts in rt_bind_exception(). 1356 */ 1357 fnhe->fnhe_daddr = 0; 1358 fnhe_flush_routes(fnhe); 1359 kfree_rcu(fnhe, rcu); 1360 break; 1361 } 1362 fnhe_p = &fnhe->fnhe_next; 1363 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1364 lockdep_is_held(&fnhe_lock)); 1365 } 1366 1367 spin_unlock_bh(&fnhe_lock); 1368 } 1369 1370 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1371 __be32 daddr) 1372 { 1373 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1374 struct fib_nh_exception *fnhe; 1375 u32 hval; 1376 1377 if (!hash) 1378 return NULL; 1379 1380 hval = fnhe_hashfun(daddr); 1381 1382 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1383 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1384 if (fnhe->fnhe_daddr == daddr) { 1385 if (fnhe->fnhe_expires && 1386 time_after(jiffies, fnhe->fnhe_expires)) { 1387 ip_del_fnhe(nhc, daddr); 1388 break; 1389 } 1390 return fnhe; 1391 } 1392 } 1393 return NULL; 1394 } 1395 1396 /* MTU selection: 1397 * 1. mtu on route is locked - use it 1398 * 2. mtu from nexthop exception 1399 * 3. mtu from egress device 1400 */ 1401 1402 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1403 { 1404 struct fib_nh_common *nhc = res->nhc; 1405 struct net_device *dev = nhc->nhc_dev; 1406 struct fib_info *fi = res->fi; 1407 u32 mtu = 0; 1408 1409 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1410 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1411 mtu = fi->fib_mtu; 1412 1413 if (likely(!mtu)) { 1414 struct fib_nh_exception *fnhe; 1415 1416 fnhe = find_exception(nhc, daddr); 1417 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1418 mtu = fnhe->fnhe_pmtu; 1419 } 1420 1421 if (likely(!mtu)) 1422 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1423 1424 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1425 } 1426 1427 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1428 __be32 daddr, const bool do_cache) 1429 { 1430 bool ret = false; 1431 1432 spin_lock_bh(&fnhe_lock); 1433 1434 if (daddr == fnhe->fnhe_daddr) { 1435 struct rtable __rcu **porig; 1436 struct rtable *orig; 1437 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1438 1439 if (rt_is_input_route(rt)) 1440 porig = &fnhe->fnhe_rth_input; 1441 else 1442 porig = &fnhe->fnhe_rth_output; 1443 orig = rcu_dereference(*porig); 1444 1445 if (fnhe->fnhe_genid != genid) { 1446 fnhe->fnhe_genid = genid; 1447 fnhe->fnhe_gw = 0; 1448 fnhe->fnhe_pmtu = 0; 1449 fnhe->fnhe_expires = 0; 1450 fnhe->fnhe_mtu_locked = false; 1451 fnhe_flush_routes(fnhe); 1452 orig = NULL; 1453 } 1454 fill_route_from_fnhe(rt, fnhe); 1455 if (!rt->rt_gw4) { 1456 rt->rt_gw4 = daddr; 1457 rt->rt_gw_family = AF_INET; 1458 } 1459 1460 if (do_cache) { 1461 dst_hold(&rt->dst); 1462 rcu_assign_pointer(*porig, rt); 1463 if (orig) { 1464 dst_dev_put(&orig->dst); 1465 dst_release(&orig->dst); 1466 } 1467 ret = true; 1468 } 1469 1470 fnhe->fnhe_stamp = jiffies; 1471 } 1472 spin_unlock_bh(&fnhe_lock); 1473 1474 return ret; 1475 } 1476 1477 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1478 { 1479 struct rtable *orig, *prev, **p; 1480 bool ret = true; 1481 1482 if (rt_is_input_route(rt)) { 1483 p = (struct rtable **)&nhc->nhc_rth_input; 1484 } else { 1485 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1486 } 1487 orig = *p; 1488 1489 /* hold dst before doing cmpxchg() to avoid race condition 1490 * on this dst 1491 */ 1492 dst_hold(&rt->dst); 1493 prev = cmpxchg(p, orig, rt); 1494 if (prev == orig) { 1495 if (orig) { 1496 rt_add_uncached_list(orig); 1497 dst_release(&orig->dst); 1498 } 1499 } else { 1500 dst_release(&rt->dst); 1501 ret = false; 1502 } 1503 1504 return ret; 1505 } 1506 1507 struct uncached_list { 1508 spinlock_t lock; 1509 struct list_head head; 1510 }; 1511 1512 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1513 1514 void rt_add_uncached_list(struct rtable *rt) 1515 { 1516 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1517 1518 rt->dst.rt_uncached_list = ul; 1519 1520 spin_lock_bh(&ul->lock); 1521 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1522 spin_unlock_bh(&ul->lock); 1523 } 1524 1525 void rt_del_uncached_list(struct rtable *rt) 1526 { 1527 if (!list_empty(&rt->dst.rt_uncached)) { 1528 struct uncached_list *ul = rt->dst.rt_uncached_list; 1529 1530 spin_lock_bh(&ul->lock); 1531 list_del_init(&rt->dst.rt_uncached); 1532 spin_unlock_bh(&ul->lock); 1533 } 1534 } 1535 1536 static void ipv4_dst_destroy(struct dst_entry *dst) 1537 { 1538 ip_dst_metrics_put(dst); 1539 rt_del_uncached_list(dst_rtable(dst)); 1540 } 1541 1542 void rt_flush_dev(struct net_device *dev) 1543 { 1544 struct rtable *rt, *safe; 1545 int cpu; 1546 1547 for_each_possible_cpu(cpu) { 1548 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1549 1550 if (list_empty(&ul->head)) 1551 continue; 1552 1553 spin_lock_bh(&ul->lock); 1554 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1555 if (rt->dst.dev != dev) 1556 continue; 1557 rt->dst.dev = blackhole_netdev; 1558 netdev_ref_replace(dev, blackhole_netdev, 1559 &rt->dst.dev_tracker, GFP_ATOMIC); 1560 list_del_init(&rt->dst.rt_uncached); 1561 } 1562 spin_unlock_bh(&ul->lock); 1563 } 1564 } 1565 1566 static bool rt_cache_valid(const struct rtable *rt) 1567 { 1568 return rt && 1569 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1570 !rt_is_expired(rt); 1571 } 1572 1573 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1574 const struct fib_result *res, 1575 struct fib_nh_exception *fnhe, 1576 struct fib_info *fi, u16 type, u32 itag, 1577 const bool do_cache) 1578 { 1579 bool cached = false; 1580 1581 if (fi) { 1582 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1583 1584 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1585 rt->rt_uses_gateway = 1; 1586 rt->rt_gw_family = nhc->nhc_gw_family; 1587 /* only INET and INET6 are supported */ 1588 if (likely(nhc->nhc_gw_family == AF_INET)) 1589 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1590 else 1591 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1592 } 1593 1594 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1595 1596 #ifdef CONFIG_IP_ROUTE_CLASSID 1597 if (nhc->nhc_family == AF_INET) { 1598 struct fib_nh *nh; 1599 1600 nh = container_of(nhc, struct fib_nh, nh_common); 1601 rt->dst.tclassid = nh->nh_tclassid; 1602 } 1603 #endif 1604 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1605 if (unlikely(fnhe)) 1606 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1607 else if (do_cache) 1608 cached = rt_cache_route(nhc, rt); 1609 if (unlikely(!cached)) { 1610 /* Routes we intend to cache in nexthop exception or 1611 * FIB nexthop have the DST_NOCACHE bit clear. 1612 * However, if we are unsuccessful at storing this 1613 * route into the cache we really need to set it. 1614 */ 1615 if (!rt->rt_gw4) { 1616 rt->rt_gw_family = AF_INET; 1617 rt->rt_gw4 = daddr; 1618 } 1619 rt_add_uncached_list(rt); 1620 } 1621 } else 1622 rt_add_uncached_list(rt); 1623 1624 #ifdef CONFIG_IP_ROUTE_CLASSID 1625 #ifdef CONFIG_IP_MULTIPLE_TABLES 1626 set_class_tag(rt, res->tclassid); 1627 #endif 1628 set_class_tag(rt, itag); 1629 #endif 1630 } 1631 1632 struct rtable *rt_dst_alloc(struct net_device *dev, 1633 unsigned int flags, u16 type, 1634 bool noxfrm) 1635 { 1636 struct rtable *rt; 1637 1638 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1639 (noxfrm ? DST_NOXFRM : 0)); 1640 1641 if (rt) { 1642 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1643 rt->rt_flags = flags; 1644 rt->rt_type = type; 1645 rt->rt_is_input = 0; 1646 rt->rt_iif = 0; 1647 rt->rt_pmtu = 0; 1648 rt->rt_mtu_locked = 0; 1649 rt->rt_uses_gateway = 0; 1650 rt->rt_gw_family = 0; 1651 rt->rt_gw4 = 0; 1652 1653 rt->dst.output = ip_output; 1654 if (flags & RTCF_LOCAL) 1655 rt->dst.input = ip_local_deliver; 1656 } 1657 1658 return rt; 1659 } 1660 EXPORT_SYMBOL(rt_dst_alloc); 1661 1662 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1663 { 1664 struct rtable *new_rt; 1665 1666 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1667 rt->dst.flags); 1668 1669 if (new_rt) { 1670 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1671 new_rt->rt_flags = rt->rt_flags; 1672 new_rt->rt_type = rt->rt_type; 1673 new_rt->rt_is_input = rt->rt_is_input; 1674 new_rt->rt_iif = rt->rt_iif; 1675 new_rt->rt_pmtu = rt->rt_pmtu; 1676 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1677 new_rt->rt_gw_family = rt->rt_gw_family; 1678 if (rt->rt_gw_family == AF_INET) 1679 new_rt->rt_gw4 = rt->rt_gw4; 1680 else if (rt->rt_gw_family == AF_INET6) 1681 new_rt->rt_gw6 = rt->rt_gw6; 1682 1683 new_rt->dst.input = rt->dst.input; 1684 new_rt->dst.output = rt->dst.output; 1685 new_rt->dst.error = rt->dst.error; 1686 new_rt->dst.lastuse = jiffies; 1687 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1688 } 1689 return new_rt; 1690 } 1691 EXPORT_SYMBOL(rt_dst_clone); 1692 1693 /* called in rcu_read_lock() section */ 1694 enum skb_drop_reason 1695 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1696 dscp_t dscp, struct net_device *dev, 1697 struct in_device *in_dev, u32 *itag) 1698 { 1699 enum skb_drop_reason reason; 1700 1701 /* Primary sanity checks. */ 1702 if (!in_dev) 1703 return SKB_DROP_REASON_NOT_SPECIFIED; 1704 1705 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1706 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1707 1708 if (skb->protocol != htons(ETH_P_IP)) 1709 return SKB_DROP_REASON_INVALID_PROTO; 1710 1711 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1712 return SKB_DROP_REASON_IP_LOCALNET; 1713 1714 if (ipv4_is_zeronet(saddr)) { 1715 if (!ipv4_is_local_multicast(daddr) && 1716 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1717 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1718 } else { 1719 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1720 dev, in_dev, itag); 1721 if (reason) 1722 return reason; 1723 } 1724 return SKB_NOT_DROPPED_YET; 1725 } 1726 1727 /* called in rcu_read_lock() section */ 1728 static enum skb_drop_reason 1729 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1730 dscp_t dscp, struct net_device *dev, int our) 1731 { 1732 struct in_device *in_dev = __in_dev_get_rcu(dev); 1733 unsigned int flags = RTCF_MULTICAST; 1734 enum skb_drop_reason reason; 1735 struct rtable *rth; 1736 u32 itag = 0; 1737 1738 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1739 &itag); 1740 if (reason) 1741 return reason; 1742 1743 if (our) 1744 flags |= RTCF_LOCAL; 1745 1746 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1747 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1748 1749 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1750 false); 1751 if (!rth) 1752 return SKB_DROP_REASON_NOMEM; 1753 1754 #ifdef CONFIG_IP_ROUTE_CLASSID 1755 rth->dst.tclassid = itag; 1756 #endif 1757 rth->dst.output = ip_rt_bug; 1758 rth->rt_is_input= 1; 1759 1760 #ifdef CONFIG_IP_MROUTE 1761 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1762 rth->dst.input = ip_mr_input; 1763 #endif 1764 RT_CACHE_STAT_INC(in_slow_mc); 1765 1766 skb_dst_drop(skb); 1767 skb_dst_set(skb, &rth->dst); 1768 return SKB_NOT_DROPPED_YET; 1769 } 1770 1771 1772 static void ip_handle_martian_source(struct net_device *dev, 1773 struct in_device *in_dev, 1774 struct sk_buff *skb, 1775 __be32 daddr, 1776 __be32 saddr) 1777 { 1778 RT_CACHE_STAT_INC(in_martian_src); 1779 #ifdef CONFIG_IP_ROUTE_VERBOSE 1780 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1781 /* 1782 * RFC1812 recommendation, if source is martian, 1783 * the only hint is MAC header. 1784 */ 1785 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1786 &daddr, &saddr, dev->name); 1787 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1788 print_hex_dump(KERN_WARNING, "ll header: ", 1789 DUMP_PREFIX_OFFSET, 16, 1, 1790 skb_mac_header(skb), 1791 dev->hard_header_len, false); 1792 } 1793 } 1794 #endif 1795 } 1796 1797 /* called in rcu_read_lock() section */ 1798 static enum skb_drop_reason 1799 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1800 struct in_device *in_dev, __be32 daddr, 1801 __be32 saddr, dscp_t dscp) 1802 { 1803 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1804 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1805 struct net_device *dev = nhc->nhc_dev; 1806 struct fib_nh_exception *fnhe; 1807 struct rtable *rth; 1808 int err; 1809 struct in_device *out_dev; 1810 bool do_cache; 1811 u32 itag = 0; 1812 1813 /* get a working reference to the output device */ 1814 out_dev = __in_dev_get_rcu(dev); 1815 if (!out_dev) { 1816 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1817 return reason; 1818 } 1819 1820 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1821 in_dev->dev, in_dev, &itag); 1822 if (err < 0) { 1823 reason = -err; 1824 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1825 saddr); 1826 1827 goto cleanup; 1828 } 1829 1830 do_cache = res->fi && !itag; 1831 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1832 skb->protocol == htons(ETH_P_IP)) { 1833 __be32 gw; 1834 1835 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1836 if (IN_DEV_SHARED_MEDIA(out_dev) || 1837 inet_addr_onlink(out_dev, saddr, gw)) 1838 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1839 } 1840 1841 if (skb->protocol != htons(ETH_P_IP)) { 1842 /* Not IP (i.e. ARP). Do not create route, if it is 1843 * invalid for proxy arp. DNAT routes are always valid. 1844 * 1845 * Proxy arp feature have been extended to allow, ARP 1846 * replies back to the same interface, to support 1847 * Private VLAN switch technologies. See arp.c. 1848 */ 1849 if (out_dev == in_dev && 1850 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1851 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1852 goto cleanup; 1853 } 1854 } 1855 1856 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1857 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1858 1859 fnhe = find_exception(nhc, daddr); 1860 if (do_cache) { 1861 if (fnhe) 1862 rth = rcu_dereference(fnhe->fnhe_rth_input); 1863 else 1864 rth = rcu_dereference(nhc->nhc_rth_input); 1865 if (rt_cache_valid(rth)) { 1866 skb_dst_set_noref(skb, &rth->dst); 1867 goto out; 1868 } 1869 } 1870 1871 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1872 IN_DEV_ORCONF(out_dev, NOXFRM)); 1873 if (!rth) { 1874 reason = SKB_DROP_REASON_NOMEM; 1875 goto cleanup; 1876 } 1877 1878 rth->rt_is_input = 1; 1879 RT_CACHE_STAT_INC(in_slow_tot); 1880 1881 rth->dst.input = ip_forward; 1882 1883 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1884 do_cache); 1885 lwtunnel_set_redirect(&rth->dst); 1886 skb_dst_set(skb, &rth->dst); 1887 out: 1888 reason = SKB_NOT_DROPPED_YET; 1889 cleanup: 1890 return reason; 1891 } 1892 1893 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1894 /* To make ICMP packets follow the right flow, the multipath hash is 1895 * calculated from the inner IP addresses. 1896 */ 1897 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1898 struct flow_keys *hash_keys) 1899 { 1900 const struct iphdr *outer_iph = ip_hdr(skb); 1901 const struct iphdr *key_iph = outer_iph; 1902 const struct iphdr *inner_iph; 1903 const struct icmphdr *icmph; 1904 struct iphdr _inner_iph; 1905 struct icmphdr _icmph; 1906 1907 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1908 goto out; 1909 1910 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1911 goto out; 1912 1913 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1914 &_icmph); 1915 if (!icmph) 1916 goto out; 1917 1918 if (!icmp_is_err(icmph->type)) 1919 goto out; 1920 1921 inner_iph = skb_header_pointer(skb, 1922 outer_iph->ihl * 4 + sizeof(_icmph), 1923 sizeof(_inner_iph), &_inner_iph); 1924 if (!inner_iph) 1925 goto out; 1926 1927 key_iph = inner_iph; 1928 out: 1929 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1930 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1931 } 1932 1933 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1934 const struct sk_buff *skb, 1935 bool *p_has_inner) 1936 { 1937 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1938 struct flow_keys keys, hash_keys; 1939 1940 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1941 return 0; 1942 1943 memset(&hash_keys, 0, sizeof(hash_keys)); 1944 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1945 1946 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1947 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1948 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1949 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1950 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1951 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1952 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1953 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1954 hash_keys.ports.src = keys.ports.src; 1955 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1956 hash_keys.ports.dst = keys.ports.dst; 1957 1958 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1959 return fib_multipath_hash_from_keys(net, &hash_keys); 1960 } 1961 1962 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1963 const struct sk_buff *skb, 1964 bool has_inner) 1965 { 1966 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1967 struct flow_keys keys, hash_keys; 1968 1969 /* We assume the packet carries an encapsulation, but if none was 1970 * encountered during dissection of the outer flow, then there is no 1971 * point in calling the flow dissector again. 1972 */ 1973 if (!has_inner) 1974 return 0; 1975 1976 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1977 return 0; 1978 1979 memset(&hash_keys, 0, sizeof(hash_keys)); 1980 skb_flow_dissect_flow_keys(skb, &keys, 0); 1981 1982 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1983 return 0; 1984 1985 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1986 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1988 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1989 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1990 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1991 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1992 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1993 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1994 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1996 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1998 hash_keys.tags.flow_label = keys.tags.flow_label; 1999 } 2000 2001 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2002 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2003 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2004 hash_keys.ports.src = keys.ports.src; 2005 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2006 hash_keys.ports.dst = keys.ports.dst; 2007 2008 return fib_multipath_hash_from_keys(net, &hash_keys); 2009 } 2010 2011 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2012 const struct sk_buff *skb) 2013 { 2014 u32 mhash, mhash_inner; 2015 bool has_inner = true; 2016 2017 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2018 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2019 2020 return jhash_2words(mhash, mhash_inner, 0); 2021 } 2022 2023 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2024 const struct flowi4 *fl4) 2025 { 2026 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2027 struct flow_keys hash_keys; 2028 2029 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2030 return 0; 2031 2032 memset(&hash_keys, 0, sizeof(hash_keys)); 2033 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2034 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2035 hash_keys.addrs.v4addrs.src = fl4->saddr; 2036 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2037 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2038 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2039 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2040 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2041 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2042 hash_keys.ports.src = (__force __be16)get_random_u16(); 2043 else 2044 hash_keys.ports.src = fl4->fl4_sport; 2045 } 2046 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2047 hash_keys.ports.dst = fl4->fl4_dport; 2048 2049 return fib_multipath_hash_from_keys(net, &hash_keys); 2050 } 2051 2052 /* if skb is set it will be used and fl4 can be NULL */ 2053 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2054 const struct sk_buff *skb, struct flow_keys *flkeys) 2055 { 2056 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2057 struct flow_keys hash_keys; 2058 u32 mhash = 0; 2059 2060 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2061 case 0: 2062 memset(&hash_keys, 0, sizeof(hash_keys)); 2063 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2064 if (skb) { 2065 ip_multipath_l3_keys(skb, &hash_keys); 2066 } else { 2067 hash_keys.addrs.v4addrs.src = fl4->saddr; 2068 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2069 } 2070 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2071 break; 2072 case 1: 2073 /* skb is currently provided only when forwarding */ 2074 if (skb) { 2075 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2076 struct flow_keys keys; 2077 2078 /* short-circuit if we already have L4 hash present */ 2079 if (skb->l4_hash) 2080 return skb_get_hash_raw(skb) >> 1; 2081 2082 memset(&hash_keys, 0, sizeof(hash_keys)); 2083 2084 if (!flkeys) { 2085 skb_flow_dissect_flow_keys(skb, &keys, flag); 2086 flkeys = &keys; 2087 } 2088 2089 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2090 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2091 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2092 hash_keys.ports.src = flkeys->ports.src; 2093 hash_keys.ports.dst = flkeys->ports.dst; 2094 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2095 } else { 2096 memset(&hash_keys, 0, sizeof(hash_keys)); 2097 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2098 hash_keys.addrs.v4addrs.src = fl4->saddr; 2099 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2100 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2101 hash_keys.ports.src = (__force __be16)get_random_u16(); 2102 else 2103 hash_keys.ports.src = fl4->fl4_sport; 2104 hash_keys.ports.dst = fl4->fl4_dport; 2105 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2106 } 2107 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2108 break; 2109 case 2: 2110 memset(&hash_keys, 0, sizeof(hash_keys)); 2111 /* skb is currently provided only when forwarding */ 2112 if (skb) { 2113 struct flow_keys keys; 2114 2115 skb_flow_dissect_flow_keys(skb, &keys, 0); 2116 /* Inner can be v4 or v6 */ 2117 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2118 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2119 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2120 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2121 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2122 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2123 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2124 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2125 hash_keys.tags.flow_label = keys.tags.flow_label; 2126 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2127 } else { 2128 /* Same as case 0 */ 2129 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2130 ip_multipath_l3_keys(skb, &hash_keys); 2131 } 2132 } else { 2133 /* Same as case 0 */ 2134 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2135 hash_keys.addrs.v4addrs.src = fl4->saddr; 2136 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2137 } 2138 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2139 break; 2140 case 3: 2141 if (skb) 2142 mhash = fib_multipath_custom_hash_skb(net, skb); 2143 else 2144 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2145 break; 2146 } 2147 2148 if (multipath_hash) 2149 mhash = jhash_2words(mhash, multipath_hash, 0); 2150 2151 return mhash >> 1; 2152 } 2153 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2154 2155 static enum skb_drop_reason 2156 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2157 struct in_device *in_dev, __be32 daddr, 2158 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2159 { 2160 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2161 if (res->fi && fib_info_num_path(res->fi) > 1) { 2162 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2163 2164 fib_select_multipath(res, h, NULL); 2165 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2166 } 2167 #endif 2168 2169 /* create a routing cache entry */ 2170 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2171 } 2172 2173 /* Implements all the saddr-related checks as ip_route_input_slow(), 2174 * assuming daddr is valid and the destination is not a local broadcast one. 2175 * Uses the provided hint instead of performing a route lookup. 2176 */ 2177 enum skb_drop_reason 2178 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2179 dscp_t dscp, struct net_device *dev, 2180 const struct sk_buff *hint) 2181 { 2182 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2183 struct in_device *in_dev = __in_dev_get_rcu(dev); 2184 struct rtable *rt = skb_rtable(hint); 2185 struct net *net = dev_net(dev); 2186 u32 tag = 0; 2187 2188 if (!in_dev) 2189 return reason; 2190 2191 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2192 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2193 goto martian_source; 2194 } 2195 2196 if (ipv4_is_zeronet(saddr)) { 2197 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2198 goto martian_source; 2199 } 2200 2201 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2202 reason = SKB_DROP_REASON_IP_LOCALNET; 2203 goto martian_source; 2204 } 2205 2206 if (rt->rt_type != RTN_LOCAL) 2207 goto skip_validate_source; 2208 2209 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2210 in_dev, &tag); 2211 if (reason) 2212 goto martian_source; 2213 2214 skip_validate_source: 2215 skb_dst_copy(skb, hint); 2216 return SKB_NOT_DROPPED_YET; 2217 2218 martian_source: 2219 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2220 return reason; 2221 } 2222 2223 /* get device for dst_alloc with local routes */ 2224 static struct net_device *ip_rt_get_dev(struct net *net, 2225 const struct fib_result *res) 2226 { 2227 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2228 struct net_device *dev = NULL; 2229 2230 if (nhc) 2231 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2232 2233 return dev ? : net->loopback_dev; 2234 } 2235 2236 /* 2237 * NOTE. We drop all the packets that has local source 2238 * addresses, because every properly looped back packet 2239 * must have correct destination already attached by output routine. 2240 * Changes in the enforced policies must be applied also to 2241 * ip_route_use_hint(). 2242 * 2243 * Such approach solves two big problems: 2244 * 1. Not simplex devices are handled properly. 2245 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2246 * called with rcu_read_lock() 2247 */ 2248 2249 static enum skb_drop_reason 2250 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2251 dscp_t dscp, struct net_device *dev, 2252 struct fib_result *res) 2253 { 2254 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2255 struct in_device *in_dev = __in_dev_get_rcu(dev); 2256 struct flow_keys *flkeys = NULL, _flkeys; 2257 struct net *net = dev_net(dev); 2258 struct ip_tunnel_info *tun_info; 2259 int err = -EINVAL; 2260 unsigned int flags = 0; 2261 u32 itag = 0; 2262 struct rtable *rth; 2263 struct flowi4 fl4; 2264 bool do_cache = true; 2265 2266 /* IP on this device is disabled. */ 2267 2268 if (!in_dev) 2269 goto out; 2270 2271 /* Check for the most weird martians, which can be not detected 2272 * by fib_lookup. 2273 */ 2274 2275 tun_info = skb_tunnel_info(skb); 2276 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2277 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2278 else 2279 fl4.flowi4_tun_key.tun_id = 0; 2280 skb_dst_drop(skb); 2281 2282 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2283 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2284 goto martian_source; 2285 } 2286 2287 res->fi = NULL; 2288 res->table = NULL; 2289 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2290 goto brd_input; 2291 2292 /* Accept zero addresses only to limited broadcast; 2293 * I even do not know to fix it or not. Waiting for complains :-) 2294 */ 2295 if (ipv4_is_zeronet(saddr)) { 2296 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2297 goto martian_source; 2298 } 2299 2300 if (ipv4_is_zeronet(daddr)) { 2301 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2302 goto martian_destination; 2303 } 2304 2305 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2306 * and call it once if daddr or/and saddr are loopback addresses 2307 */ 2308 if (ipv4_is_loopback(daddr)) { 2309 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2310 reason = SKB_DROP_REASON_IP_LOCALNET; 2311 goto martian_destination; 2312 } 2313 } else if (ipv4_is_loopback(saddr)) { 2314 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2315 reason = SKB_DROP_REASON_IP_LOCALNET; 2316 goto martian_source; 2317 } 2318 } 2319 2320 /* 2321 * Now we are ready to route packet. 2322 */ 2323 fl4.flowi4_l3mdev = 0; 2324 fl4.flowi4_oif = 0; 2325 fl4.flowi4_iif = dev->ifindex; 2326 fl4.flowi4_mark = skb->mark; 2327 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp); 2328 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2329 fl4.flowi4_flags = 0; 2330 fl4.daddr = daddr; 2331 fl4.saddr = saddr; 2332 fl4.flowi4_uid = sock_net_uid(net, NULL); 2333 fl4.flowi4_multipath_hash = 0; 2334 2335 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2336 flkeys = &_flkeys; 2337 } else { 2338 fl4.flowi4_proto = 0; 2339 fl4.fl4_sport = 0; 2340 fl4.fl4_dport = 0; 2341 } 2342 2343 err = fib_lookup(net, &fl4, res, 0); 2344 if (err != 0) { 2345 if (!IN_DEV_FORWARD(in_dev)) 2346 err = -EHOSTUNREACH; 2347 goto no_route; 2348 } 2349 2350 if (res->type == RTN_BROADCAST) { 2351 if (IN_DEV_BFORWARD(in_dev)) 2352 goto make_route; 2353 /* not do cache if bc_forwarding is enabled */ 2354 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2355 do_cache = false; 2356 goto brd_input; 2357 } 2358 2359 err = -EINVAL; 2360 if (res->type == RTN_LOCAL) { 2361 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2362 0, dev, in_dev, &itag); 2363 if (reason) 2364 goto martian_source; 2365 goto local_input; 2366 } 2367 2368 if (!IN_DEV_FORWARD(in_dev)) { 2369 err = -EHOSTUNREACH; 2370 goto no_route; 2371 } 2372 if (res->type != RTN_UNICAST) { 2373 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2374 goto martian_destination; 2375 } 2376 2377 make_route: 2378 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2379 flkeys); 2380 2381 out: 2382 return reason; 2383 2384 brd_input: 2385 if (skb->protocol != htons(ETH_P_IP)) { 2386 reason = SKB_DROP_REASON_INVALID_PROTO; 2387 goto out; 2388 } 2389 2390 if (!ipv4_is_zeronet(saddr)) { 2391 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2392 dev, in_dev, &itag); 2393 if (reason) 2394 goto martian_source; 2395 } 2396 flags |= RTCF_BROADCAST; 2397 res->type = RTN_BROADCAST; 2398 RT_CACHE_STAT_INC(in_brd); 2399 2400 local_input: 2401 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2402 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2403 2404 do_cache &= res->fi && !itag; 2405 if (do_cache) { 2406 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2407 2408 rth = rcu_dereference(nhc->nhc_rth_input); 2409 if (rt_cache_valid(rth)) { 2410 skb_dst_set_noref(skb, &rth->dst); 2411 reason = SKB_NOT_DROPPED_YET; 2412 goto out; 2413 } 2414 } 2415 2416 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2417 flags | RTCF_LOCAL, res->type, false); 2418 if (!rth) 2419 goto e_nobufs; 2420 2421 rth->dst.output= ip_rt_bug; 2422 #ifdef CONFIG_IP_ROUTE_CLASSID 2423 rth->dst.tclassid = itag; 2424 #endif 2425 rth->rt_is_input = 1; 2426 2427 RT_CACHE_STAT_INC(in_slow_tot); 2428 if (res->type == RTN_UNREACHABLE) { 2429 rth->dst.input= ip_error; 2430 rth->dst.error= -err; 2431 rth->rt_flags &= ~RTCF_LOCAL; 2432 } 2433 2434 if (do_cache) { 2435 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2436 2437 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2438 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2439 WARN_ON(rth->dst.input == lwtunnel_input); 2440 rth->dst.lwtstate->orig_input = rth->dst.input; 2441 rth->dst.input = lwtunnel_input; 2442 } 2443 2444 if (unlikely(!rt_cache_route(nhc, rth))) 2445 rt_add_uncached_list(rth); 2446 } 2447 skb_dst_set(skb, &rth->dst); 2448 reason = SKB_NOT_DROPPED_YET; 2449 goto out; 2450 2451 no_route: 2452 RT_CACHE_STAT_INC(in_no_route); 2453 res->type = RTN_UNREACHABLE; 2454 res->fi = NULL; 2455 res->table = NULL; 2456 goto local_input; 2457 2458 /* 2459 * Do not cache martian addresses: they should be logged (RFC1812) 2460 */ 2461 martian_destination: 2462 RT_CACHE_STAT_INC(in_martian_dst); 2463 #ifdef CONFIG_IP_ROUTE_VERBOSE 2464 if (IN_DEV_LOG_MARTIANS(in_dev)) 2465 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2466 &daddr, &saddr, dev->name); 2467 #endif 2468 goto out; 2469 2470 e_nobufs: 2471 reason = SKB_DROP_REASON_NOMEM; 2472 goto out; 2473 2474 martian_source: 2475 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2476 goto out; 2477 } 2478 2479 /* called with rcu_read_lock held */ 2480 static enum skb_drop_reason 2481 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2482 dscp_t dscp, struct net_device *dev, 2483 struct fib_result *res) 2484 { 2485 /* Multicast recognition logic is moved from route cache to here. 2486 * The problem was that too many Ethernet cards have broken/missing 2487 * hardware multicast filters :-( As result the host on multicasting 2488 * network acquires a lot of useless route cache entries, sort of 2489 * SDR messages from all the world. Now we try to get rid of them. 2490 * Really, provided software IP multicast filter is organized 2491 * reasonably (at least, hashed), it does not result in a slowdown 2492 * comparing with route cache reject entries. 2493 * Note, that multicast routers are not affected, because 2494 * route cache entry is created eventually. 2495 */ 2496 if (ipv4_is_multicast(daddr)) { 2497 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2498 struct in_device *in_dev = __in_dev_get_rcu(dev); 2499 int our = 0; 2500 2501 if (!in_dev) 2502 return reason; 2503 2504 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2505 ip_hdr(skb)->protocol); 2506 2507 /* check l3 master if no match yet */ 2508 if (!our && netif_is_l3_slave(dev)) { 2509 struct in_device *l3_in_dev; 2510 2511 l3_in_dev = __in_dev_get_rcu(skb->dev); 2512 if (l3_in_dev) 2513 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2514 ip_hdr(skb)->protocol); 2515 } 2516 2517 if (our 2518 #ifdef CONFIG_IP_MROUTE 2519 || 2520 (!ipv4_is_local_multicast(daddr) && 2521 IN_DEV_MFORWARD(in_dev)) 2522 #endif 2523 ) { 2524 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2525 dev, our); 2526 } 2527 return reason; 2528 } 2529 2530 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2531 } 2532 2533 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2534 __be32 saddr, dscp_t dscp, 2535 struct net_device *dev) 2536 { 2537 enum skb_drop_reason reason; 2538 struct fib_result res; 2539 2540 rcu_read_lock(); 2541 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2542 rcu_read_unlock(); 2543 2544 return reason; 2545 } 2546 EXPORT_SYMBOL(ip_route_input_noref); 2547 2548 /* called with rcu_read_lock() */ 2549 static struct rtable *__mkroute_output(const struct fib_result *res, 2550 const struct flowi4 *fl4, int orig_oif, 2551 struct net_device *dev_out, 2552 unsigned int flags) 2553 { 2554 struct fib_info *fi = res->fi; 2555 struct fib_nh_exception *fnhe; 2556 struct in_device *in_dev; 2557 u16 type = res->type; 2558 struct rtable *rth; 2559 bool do_cache; 2560 2561 in_dev = __in_dev_get_rcu(dev_out); 2562 if (!in_dev) 2563 return ERR_PTR(-EINVAL); 2564 2565 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2566 if (ipv4_is_loopback(fl4->saddr) && 2567 !(dev_out->flags & IFF_LOOPBACK) && 2568 !netif_is_l3_master(dev_out)) 2569 return ERR_PTR(-EINVAL); 2570 2571 if (ipv4_is_lbcast(fl4->daddr)) 2572 type = RTN_BROADCAST; 2573 else if (ipv4_is_multicast(fl4->daddr)) 2574 type = RTN_MULTICAST; 2575 else if (ipv4_is_zeronet(fl4->daddr)) 2576 return ERR_PTR(-EINVAL); 2577 2578 if (dev_out->flags & IFF_LOOPBACK) 2579 flags |= RTCF_LOCAL; 2580 2581 do_cache = true; 2582 if (type == RTN_BROADCAST) { 2583 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2584 fi = NULL; 2585 } else if (type == RTN_MULTICAST) { 2586 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2587 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2588 fl4->flowi4_proto)) 2589 flags &= ~RTCF_LOCAL; 2590 else 2591 do_cache = false; 2592 /* If multicast route do not exist use 2593 * default one, but do not gateway in this case. 2594 * Yes, it is hack. 2595 */ 2596 if (fi && res->prefixlen < 4) 2597 fi = NULL; 2598 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2599 (orig_oif != dev_out->ifindex)) { 2600 /* For local routes that require a particular output interface 2601 * we do not want to cache the result. Caching the result 2602 * causes incorrect behaviour when there are multiple source 2603 * addresses on the interface, the end result being that if the 2604 * intended recipient is waiting on that interface for the 2605 * packet he won't receive it because it will be delivered on 2606 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2607 * be set to the loopback interface as well. 2608 */ 2609 do_cache = false; 2610 } 2611 2612 fnhe = NULL; 2613 do_cache &= fi != NULL; 2614 if (fi) { 2615 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2616 struct rtable __rcu **prth; 2617 2618 fnhe = find_exception(nhc, fl4->daddr); 2619 if (!do_cache) 2620 goto add; 2621 if (fnhe) { 2622 prth = &fnhe->fnhe_rth_output; 2623 } else { 2624 if (unlikely(fl4->flowi4_flags & 2625 FLOWI_FLAG_KNOWN_NH && 2626 !(nhc->nhc_gw_family && 2627 nhc->nhc_scope == RT_SCOPE_LINK))) { 2628 do_cache = false; 2629 goto add; 2630 } 2631 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2632 } 2633 rth = rcu_dereference(*prth); 2634 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2635 return rth; 2636 } 2637 2638 add: 2639 rth = rt_dst_alloc(dev_out, flags, type, 2640 IN_DEV_ORCONF(in_dev, NOXFRM)); 2641 if (!rth) 2642 return ERR_PTR(-ENOBUFS); 2643 2644 rth->rt_iif = orig_oif; 2645 2646 RT_CACHE_STAT_INC(out_slow_tot); 2647 2648 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2649 if (flags & RTCF_LOCAL && 2650 !(dev_out->flags & IFF_LOOPBACK)) { 2651 rth->dst.output = ip_mc_output; 2652 RT_CACHE_STAT_INC(out_slow_mc); 2653 } 2654 #ifdef CONFIG_IP_MROUTE 2655 if (type == RTN_MULTICAST) { 2656 if (IN_DEV_MFORWARD(in_dev) && 2657 !ipv4_is_local_multicast(fl4->daddr)) { 2658 rth->dst.input = ip_mr_input; 2659 rth->dst.output = ip_mc_output; 2660 } 2661 } 2662 #endif 2663 } 2664 2665 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2666 lwtunnel_set_redirect(&rth->dst); 2667 2668 return rth; 2669 } 2670 2671 /* 2672 * Major route resolver routine. 2673 */ 2674 2675 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2676 const struct sk_buff *skb) 2677 { 2678 struct fib_result res = { 2679 .type = RTN_UNSPEC, 2680 .fi = NULL, 2681 .table = NULL, 2682 .tclassid = 0, 2683 }; 2684 struct rtable *rth; 2685 2686 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2687 fl4->flowi4_tos &= INET_DSCP_MASK; 2688 2689 rcu_read_lock(); 2690 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2691 rcu_read_unlock(); 2692 2693 return rth; 2694 } 2695 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2696 2697 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2698 struct fib_result *res, 2699 const struct sk_buff *skb) 2700 { 2701 struct net_device *dev_out = NULL; 2702 int orig_oif = fl4->flowi4_oif; 2703 unsigned int flags = 0; 2704 struct rtable *rth; 2705 int err; 2706 2707 if (fl4->saddr) { 2708 if (ipv4_is_multicast(fl4->saddr) || 2709 ipv4_is_lbcast(fl4->saddr)) { 2710 rth = ERR_PTR(-EINVAL); 2711 goto out; 2712 } 2713 2714 rth = ERR_PTR(-ENETUNREACH); 2715 2716 /* I removed check for oif == dev_out->oif here. 2717 * It was wrong for two reasons: 2718 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2719 * is assigned to multiple interfaces. 2720 * 2. Moreover, we are allowed to send packets with saddr 2721 * of another iface. --ANK 2722 */ 2723 2724 if (fl4->flowi4_oif == 0 && 2725 (ipv4_is_multicast(fl4->daddr) || 2726 ipv4_is_lbcast(fl4->daddr))) { 2727 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2728 dev_out = __ip_dev_find(net, fl4->saddr, false); 2729 if (!dev_out) 2730 goto out; 2731 2732 /* Special hack: user can direct multicasts 2733 * and limited broadcast via necessary interface 2734 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2735 * This hack is not just for fun, it allows 2736 * vic,vat and friends to work. 2737 * They bind socket to loopback, set ttl to zero 2738 * and expect that it will work. 2739 * From the viewpoint of routing cache they are broken, 2740 * because we are not allowed to build multicast path 2741 * with loopback source addr (look, routing cache 2742 * cannot know, that ttl is zero, so that packet 2743 * will not leave this host and route is valid). 2744 * Luckily, this hack is good workaround. 2745 */ 2746 2747 fl4->flowi4_oif = dev_out->ifindex; 2748 goto make_route; 2749 } 2750 2751 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2752 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2753 if (!__ip_dev_find(net, fl4->saddr, false)) 2754 goto out; 2755 } 2756 } 2757 2758 2759 if (fl4->flowi4_oif) { 2760 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2761 rth = ERR_PTR(-ENODEV); 2762 if (!dev_out) 2763 goto out; 2764 2765 /* RACE: Check return value of inet_select_addr instead. */ 2766 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2767 rth = ERR_PTR(-ENETUNREACH); 2768 goto out; 2769 } 2770 if (ipv4_is_local_multicast(fl4->daddr) || 2771 ipv4_is_lbcast(fl4->daddr) || 2772 fl4->flowi4_proto == IPPROTO_IGMP) { 2773 if (!fl4->saddr) 2774 fl4->saddr = inet_select_addr(dev_out, 0, 2775 RT_SCOPE_LINK); 2776 goto make_route; 2777 } 2778 if (!fl4->saddr) { 2779 if (ipv4_is_multicast(fl4->daddr)) 2780 fl4->saddr = inet_select_addr(dev_out, 0, 2781 fl4->flowi4_scope); 2782 else if (!fl4->daddr) 2783 fl4->saddr = inet_select_addr(dev_out, 0, 2784 RT_SCOPE_HOST); 2785 } 2786 } 2787 2788 if (!fl4->daddr) { 2789 fl4->daddr = fl4->saddr; 2790 if (!fl4->daddr) 2791 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2792 dev_out = net->loopback_dev; 2793 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2794 res->type = RTN_LOCAL; 2795 flags |= RTCF_LOCAL; 2796 goto make_route; 2797 } 2798 2799 err = fib_lookup(net, fl4, res, 0); 2800 if (err) { 2801 res->fi = NULL; 2802 res->table = NULL; 2803 if (fl4->flowi4_oif && 2804 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2805 /* Apparently, routing tables are wrong. Assume, 2806 * that the destination is on link. 2807 * 2808 * WHY? DW. 2809 * Because we are allowed to send to iface 2810 * even if it has NO routes and NO assigned 2811 * addresses. When oif is specified, routing 2812 * tables are looked up with only one purpose: 2813 * to catch if destination is gatewayed, rather than 2814 * direct. Moreover, if MSG_DONTROUTE is set, 2815 * we send packet, ignoring both routing tables 2816 * and ifaddr state. --ANK 2817 * 2818 * 2819 * We could make it even if oif is unknown, 2820 * likely IPv6, but we do not. 2821 */ 2822 2823 if (fl4->saddr == 0) 2824 fl4->saddr = inet_select_addr(dev_out, 0, 2825 RT_SCOPE_LINK); 2826 res->type = RTN_UNICAST; 2827 goto make_route; 2828 } 2829 rth = ERR_PTR(err); 2830 goto out; 2831 } 2832 2833 if (res->type == RTN_LOCAL) { 2834 if (!fl4->saddr) { 2835 if (res->fi->fib_prefsrc) 2836 fl4->saddr = res->fi->fib_prefsrc; 2837 else 2838 fl4->saddr = fl4->daddr; 2839 } 2840 2841 /* L3 master device is the loopback for that domain */ 2842 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2843 net->loopback_dev; 2844 2845 /* make sure orig_oif points to fib result device even 2846 * though packet rx/tx happens over loopback or l3mdev 2847 */ 2848 orig_oif = FIB_RES_OIF(*res); 2849 2850 fl4->flowi4_oif = dev_out->ifindex; 2851 flags |= RTCF_LOCAL; 2852 goto make_route; 2853 } 2854 2855 fib_select_path(net, res, fl4, skb); 2856 2857 dev_out = FIB_RES_DEV(*res); 2858 2859 make_route: 2860 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2861 2862 out: 2863 return rth; 2864 } 2865 2866 static struct dst_ops ipv4_dst_blackhole_ops = { 2867 .family = AF_INET, 2868 .default_advmss = ipv4_default_advmss, 2869 .neigh_lookup = ipv4_neigh_lookup, 2870 .check = dst_blackhole_check, 2871 .cow_metrics = dst_blackhole_cow_metrics, 2872 .update_pmtu = dst_blackhole_update_pmtu, 2873 .redirect = dst_blackhole_redirect, 2874 .mtu = dst_blackhole_mtu, 2875 }; 2876 2877 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2878 { 2879 struct rtable *ort = dst_rtable(dst_orig); 2880 struct rtable *rt; 2881 2882 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2883 if (rt) { 2884 struct dst_entry *new = &rt->dst; 2885 2886 new->__use = 1; 2887 new->input = dst_discard; 2888 new->output = dst_discard_out; 2889 2890 new->dev = net->loopback_dev; 2891 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2892 2893 rt->rt_is_input = ort->rt_is_input; 2894 rt->rt_iif = ort->rt_iif; 2895 rt->rt_pmtu = ort->rt_pmtu; 2896 rt->rt_mtu_locked = ort->rt_mtu_locked; 2897 2898 rt->rt_genid = rt_genid_ipv4(net); 2899 rt->rt_flags = ort->rt_flags; 2900 rt->rt_type = ort->rt_type; 2901 rt->rt_uses_gateway = ort->rt_uses_gateway; 2902 rt->rt_gw_family = ort->rt_gw_family; 2903 if (rt->rt_gw_family == AF_INET) 2904 rt->rt_gw4 = ort->rt_gw4; 2905 else if (rt->rt_gw_family == AF_INET6) 2906 rt->rt_gw6 = ort->rt_gw6; 2907 } 2908 2909 dst_release(dst_orig); 2910 2911 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2912 } 2913 2914 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2915 const struct sock *sk) 2916 { 2917 struct rtable *rt = __ip_route_output_key(net, flp4); 2918 2919 if (IS_ERR(rt)) 2920 return rt; 2921 2922 if (flp4->flowi4_proto) { 2923 flp4->flowi4_oif = rt->dst.dev->ifindex; 2924 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2925 flowi4_to_flowi(flp4), 2926 sk, 0)); 2927 } 2928 2929 return rt; 2930 } 2931 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2932 2933 /* called with rcu_read_lock held */ 2934 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2935 struct rtable *rt, u32 table_id, dscp_t dscp, 2936 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2937 u32 seq, unsigned int flags) 2938 { 2939 struct rtmsg *r; 2940 struct nlmsghdr *nlh; 2941 unsigned long expires = 0; 2942 u32 error; 2943 u32 metrics[RTAX_MAX]; 2944 2945 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2946 if (!nlh) 2947 return -EMSGSIZE; 2948 2949 r = nlmsg_data(nlh); 2950 r->rtm_family = AF_INET; 2951 r->rtm_dst_len = 32; 2952 r->rtm_src_len = 0; 2953 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2954 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2955 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2956 goto nla_put_failure; 2957 r->rtm_type = rt->rt_type; 2958 r->rtm_scope = RT_SCOPE_UNIVERSE; 2959 r->rtm_protocol = RTPROT_UNSPEC; 2960 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2961 if (rt->rt_flags & RTCF_NOTIFY) 2962 r->rtm_flags |= RTM_F_NOTIFY; 2963 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2964 r->rtm_flags |= RTCF_DOREDIRECT; 2965 2966 if (nla_put_in_addr(skb, RTA_DST, dst)) 2967 goto nla_put_failure; 2968 if (src) { 2969 r->rtm_src_len = 32; 2970 if (nla_put_in_addr(skb, RTA_SRC, src)) 2971 goto nla_put_failure; 2972 } 2973 if (rt->dst.dev && 2974 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2975 goto nla_put_failure; 2976 if (rt->dst.lwtstate && 2977 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2978 goto nla_put_failure; 2979 #ifdef CONFIG_IP_ROUTE_CLASSID 2980 if (rt->dst.tclassid && 2981 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2982 goto nla_put_failure; 2983 #endif 2984 if (fl4 && !rt_is_input_route(rt) && 2985 fl4->saddr != src) { 2986 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2987 goto nla_put_failure; 2988 } 2989 if (rt->rt_uses_gateway) { 2990 if (rt->rt_gw_family == AF_INET && 2991 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2992 goto nla_put_failure; 2993 } else if (rt->rt_gw_family == AF_INET6) { 2994 int alen = sizeof(struct in6_addr); 2995 struct nlattr *nla; 2996 struct rtvia *via; 2997 2998 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2999 if (!nla) 3000 goto nla_put_failure; 3001 3002 via = nla_data(nla); 3003 via->rtvia_family = AF_INET6; 3004 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3005 } 3006 } 3007 3008 expires = rt->dst.expires; 3009 if (expires) { 3010 unsigned long now = jiffies; 3011 3012 if (time_before(now, expires)) 3013 expires -= now; 3014 else 3015 expires = 0; 3016 } 3017 3018 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3019 if (rt->rt_pmtu && expires) 3020 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3021 if (rt->rt_mtu_locked && expires) 3022 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3023 if (rtnetlink_put_metrics(skb, metrics) < 0) 3024 goto nla_put_failure; 3025 3026 if (fl4) { 3027 if (fl4->flowi4_mark && 3028 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3029 goto nla_put_failure; 3030 3031 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3032 nla_put_u32(skb, RTA_UID, 3033 from_kuid_munged(current_user_ns(), 3034 fl4->flowi4_uid))) 3035 goto nla_put_failure; 3036 3037 if (rt_is_input_route(rt)) { 3038 #ifdef CONFIG_IP_MROUTE 3039 if (ipv4_is_multicast(dst) && 3040 !ipv4_is_local_multicast(dst) && 3041 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3042 int err = ipmr_get_route(net, skb, 3043 fl4->saddr, fl4->daddr, 3044 r, portid); 3045 3046 if (err <= 0) { 3047 if (err == 0) 3048 return 0; 3049 goto nla_put_failure; 3050 } 3051 } else 3052 #endif 3053 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3054 goto nla_put_failure; 3055 } 3056 } 3057 3058 error = rt->dst.error; 3059 3060 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3061 goto nla_put_failure; 3062 3063 nlmsg_end(skb, nlh); 3064 return 0; 3065 3066 nla_put_failure: 3067 nlmsg_cancel(skb, nlh); 3068 return -EMSGSIZE; 3069 } 3070 3071 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3072 struct netlink_callback *cb, u32 table_id, 3073 struct fnhe_hash_bucket *bucket, int genid, 3074 int *fa_index, int fa_start, unsigned int flags) 3075 { 3076 int i; 3077 3078 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3079 struct fib_nh_exception *fnhe; 3080 3081 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3082 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3083 struct rtable *rt; 3084 int err; 3085 3086 if (*fa_index < fa_start) 3087 goto next; 3088 3089 if (fnhe->fnhe_genid != genid) 3090 goto next; 3091 3092 if (fnhe->fnhe_expires && 3093 time_after(jiffies, fnhe->fnhe_expires)) 3094 goto next; 3095 3096 rt = rcu_dereference(fnhe->fnhe_rth_input); 3097 if (!rt) 3098 rt = rcu_dereference(fnhe->fnhe_rth_output); 3099 if (!rt) 3100 goto next; 3101 3102 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3103 table_id, 0, NULL, skb, 3104 NETLINK_CB(cb->skb).portid, 3105 cb->nlh->nlmsg_seq, flags); 3106 if (err) 3107 return err; 3108 next: 3109 (*fa_index)++; 3110 } 3111 } 3112 3113 return 0; 3114 } 3115 3116 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3117 u32 table_id, struct fib_info *fi, 3118 int *fa_index, int fa_start, unsigned int flags) 3119 { 3120 struct net *net = sock_net(cb->skb->sk); 3121 int nhsel, genid = fnhe_genid(net); 3122 3123 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3124 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3125 struct fnhe_hash_bucket *bucket; 3126 int err; 3127 3128 if (nhc->nhc_flags & RTNH_F_DEAD) 3129 continue; 3130 3131 rcu_read_lock(); 3132 bucket = rcu_dereference(nhc->nhc_exceptions); 3133 err = 0; 3134 if (bucket) 3135 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3136 genid, fa_index, fa_start, 3137 flags); 3138 rcu_read_unlock(); 3139 if (err) 3140 return err; 3141 } 3142 3143 return 0; 3144 } 3145 3146 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3147 u8 ip_proto, __be16 sport, 3148 __be16 dport) 3149 { 3150 struct sk_buff *skb; 3151 struct iphdr *iph; 3152 3153 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3154 if (!skb) 3155 return NULL; 3156 3157 /* Reserve room for dummy headers, this skb can pass 3158 * through good chunk of routing engine. 3159 */ 3160 skb_reset_mac_header(skb); 3161 skb_reset_network_header(skb); 3162 skb->protocol = htons(ETH_P_IP); 3163 iph = skb_put(skb, sizeof(struct iphdr)); 3164 iph->protocol = ip_proto; 3165 iph->saddr = src; 3166 iph->daddr = dst; 3167 iph->version = 0x4; 3168 iph->frag_off = 0; 3169 iph->ihl = 0x5; 3170 skb_set_transport_header(skb, skb->len); 3171 3172 switch (iph->protocol) { 3173 case IPPROTO_UDP: { 3174 struct udphdr *udph; 3175 3176 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3177 udph->source = sport; 3178 udph->dest = dport; 3179 udph->len = htons(sizeof(struct udphdr)); 3180 udph->check = 0; 3181 break; 3182 } 3183 case IPPROTO_TCP: { 3184 struct tcphdr *tcph; 3185 3186 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3187 tcph->source = sport; 3188 tcph->dest = dport; 3189 tcph->doff = sizeof(struct tcphdr) / 4; 3190 tcph->rst = 1; 3191 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3192 src, dst, 0); 3193 break; 3194 } 3195 case IPPROTO_ICMP: { 3196 struct icmphdr *icmph; 3197 3198 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3199 icmph->type = ICMP_ECHO; 3200 icmph->code = 0; 3201 } 3202 } 3203 3204 return skb; 3205 } 3206 3207 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3208 const struct nlmsghdr *nlh, 3209 struct nlattr **tb, 3210 struct netlink_ext_ack *extack) 3211 { 3212 struct rtmsg *rtm; 3213 int i, err; 3214 3215 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3216 if (!rtm) { 3217 NL_SET_ERR_MSG(extack, 3218 "ipv4: Invalid header for route get request"); 3219 return -EINVAL; 3220 } 3221 3222 if (!netlink_strict_get_check(skb)) 3223 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3224 rtm_ipv4_policy, extack); 3225 3226 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3227 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3228 rtm->rtm_table || rtm->rtm_protocol || 3229 rtm->rtm_scope || rtm->rtm_type) { 3230 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3231 return -EINVAL; 3232 } 3233 3234 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3235 RTM_F_LOOKUP_TABLE | 3236 RTM_F_FIB_MATCH)) { 3237 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3238 return -EINVAL; 3239 } 3240 3241 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3242 rtm_ipv4_policy, extack); 3243 if (err) 3244 return err; 3245 3246 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3247 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3248 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3249 return -EINVAL; 3250 } 3251 3252 for (i = 0; i <= RTA_MAX; i++) { 3253 if (!tb[i]) 3254 continue; 3255 3256 switch (i) { 3257 case RTA_IIF: 3258 case RTA_OIF: 3259 case RTA_SRC: 3260 case RTA_DST: 3261 case RTA_IP_PROTO: 3262 case RTA_SPORT: 3263 case RTA_DPORT: 3264 case RTA_MARK: 3265 case RTA_UID: 3266 break; 3267 default: 3268 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3269 return -EINVAL; 3270 } 3271 } 3272 3273 return 0; 3274 } 3275 3276 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3277 struct netlink_ext_ack *extack) 3278 { 3279 struct net *net = sock_net(in_skb->sk); 3280 struct nlattr *tb[RTA_MAX+1]; 3281 u32 table_id = RT_TABLE_MAIN; 3282 __be16 sport = 0, dport = 0; 3283 struct fib_result res = {}; 3284 u8 ip_proto = IPPROTO_UDP; 3285 struct rtable *rt = NULL; 3286 struct sk_buff *skb; 3287 struct rtmsg *rtm; 3288 struct flowi4 fl4 = {}; 3289 __be32 dst = 0; 3290 __be32 src = 0; 3291 dscp_t dscp; 3292 kuid_t uid; 3293 u32 iif; 3294 int err; 3295 int mark; 3296 3297 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3298 if (err < 0) 3299 return err; 3300 3301 rtm = nlmsg_data(nlh); 3302 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3303 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3304 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3305 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3306 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3307 if (tb[RTA_UID]) 3308 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3309 else 3310 uid = (iif ? INVALID_UID : current_uid()); 3311 3312 if (tb[RTA_IP_PROTO]) { 3313 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3314 &ip_proto, AF_INET, extack); 3315 if (err) 3316 return err; 3317 } 3318 3319 if (tb[RTA_SPORT]) 3320 sport = nla_get_be16(tb[RTA_SPORT]); 3321 3322 if (tb[RTA_DPORT]) 3323 dport = nla_get_be16(tb[RTA_DPORT]); 3324 3325 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3326 if (!skb) 3327 return -ENOBUFS; 3328 3329 fl4.daddr = dst; 3330 fl4.saddr = src; 3331 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp); 3332 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3333 fl4.flowi4_mark = mark; 3334 fl4.flowi4_uid = uid; 3335 if (sport) 3336 fl4.fl4_sport = sport; 3337 if (dport) 3338 fl4.fl4_dport = dport; 3339 fl4.flowi4_proto = ip_proto; 3340 3341 rcu_read_lock(); 3342 3343 if (iif) { 3344 struct net_device *dev; 3345 3346 dev = dev_get_by_index_rcu(net, iif); 3347 if (!dev) { 3348 err = -ENODEV; 3349 goto errout_rcu; 3350 } 3351 3352 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3353 skb->dev = dev; 3354 skb->mark = mark; 3355 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3356 &res) ? -EINVAL : 0; 3357 3358 rt = skb_rtable(skb); 3359 if (err == 0 && rt->dst.error) 3360 err = -rt->dst.error; 3361 } else { 3362 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3363 skb->dev = net->loopback_dev; 3364 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3365 err = 0; 3366 if (IS_ERR(rt)) 3367 err = PTR_ERR(rt); 3368 else 3369 skb_dst_set(skb, &rt->dst); 3370 } 3371 3372 if (err) 3373 goto errout_rcu; 3374 3375 if (rtm->rtm_flags & RTM_F_NOTIFY) 3376 rt->rt_flags |= RTCF_NOTIFY; 3377 3378 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3379 table_id = res.table ? res.table->tb_id : 0; 3380 3381 /* reset skb for netlink reply msg */ 3382 skb_trim(skb, 0); 3383 skb_reset_network_header(skb); 3384 skb_reset_transport_header(skb); 3385 skb_reset_mac_header(skb); 3386 3387 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3388 struct fib_rt_info fri; 3389 3390 if (!res.fi) { 3391 err = fib_props[res.type].error; 3392 if (!err) 3393 err = -EHOSTUNREACH; 3394 goto errout_rcu; 3395 } 3396 fri.fi = res.fi; 3397 fri.tb_id = table_id; 3398 fri.dst = res.prefix; 3399 fri.dst_len = res.prefixlen; 3400 fri.dscp = res.dscp; 3401 fri.type = rt->rt_type; 3402 fri.offload = 0; 3403 fri.trap = 0; 3404 fri.offload_failed = 0; 3405 if (res.fa_head) { 3406 struct fib_alias *fa; 3407 3408 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3409 u8 slen = 32 - fri.dst_len; 3410 3411 if (fa->fa_slen == slen && 3412 fa->tb_id == fri.tb_id && 3413 fa->fa_dscp == fri.dscp && 3414 fa->fa_info == res.fi && 3415 fa->fa_type == fri.type) { 3416 fri.offload = READ_ONCE(fa->offload); 3417 fri.trap = READ_ONCE(fa->trap); 3418 fri.offload_failed = 3419 READ_ONCE(fa->offload_failed); 3420 break; 3421 } 3422 } 3423 } 3424 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3425 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3426 } else { 3427 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3428 skb, NETLINK_CB(in_skb).portid, 3429 nlh->nlmsg_seq, 0); 3430 } 3431 if (err < 0) 3432 goto errout_rcu; 3433 3434 rcu_read_unlock(); 3435 3436 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3437 3438 errout_free: 3439 return err; 3440 errout_rcu: 3441 rcu_read_unlock(); 3442 kfree_skb(skb); 3443 goto errout_free; 3444 } 3445 3446 void ip_rt_multicast_event(struct in_device *in_dev) 3447 { 3448 rt_cache_flush(dev_net(in_dev->dev)); 3449 } 3450 3451 #ifdef CONFIG_SYSCTL 3452 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3453 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3454 static int ip_rt_gc_elasticity __read_mostly = 8; 3455 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3456 3457 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3458 void *buffer, size_t *lenp, loff_t *ppos) 3459 { 3460 struct net *net = (struct net *)__ctl->extra1; 3461 3462 if (write) { 3463 rt_cache_flush(net); 3464 fnhe_genid_bump(net); 3465 return 0; 3466 } 3467 3468 return -EINVAL; 3469 } 3470 3471 static struct ctl_table ipv4_route_table[] = { 3472 { 3473 .procname = "gc_thresh", 3474 .data = &ipv4_dst_ops.gc_thresh, 3475 .maxlen = sizeof(int), 3476 .mode = 0644, 3477 .proc_handler = proc_dointvec, 3478 }, 3479 { 3480 .procname = "max_size", 3481 .data = &ip_rt_max_size, 3482 .maxlen = sizeof(int), 3483 .mode = 0644, 3484 .proc_handler = proc_dointvec, 3485 }, 3486 { 3487 /* Deprecated. Use gc_min_interval_ms */ 3488 3489 .procname = "gc_min_interval", 3490 .data = &ip_rt_gc_min_interval, 3491 .maxlen = sizeof(int), 3492 .mode = 0644, 3493 .proc_handler = proc_dointvec_jiffies, 3494 }, 3495 { 3496 .procname = "gc_min_interval_ms", 3497 .data = &ip_rt_gc_min_interval, 3498 .maxlen = sizeof(int), 3499 .mode = 0644, 3500 .proc_handler = proc_dointvec_ms_jiffies, 3501 }, 3502 { 3503 .procname = "gc_timeout", 3504 .data = &ip_rt_gc_timeout, 3505 .maxlen = sizeof(int), 3506 .mode = 0644, 3507 .proc_handler = proc_dointvec_jiffies, 3508 }, 3509 { 3510 .procname = "gc_interval", 3511 .data = &ip_rt_gc_interval, 3512 .maxlen = sizeof(int), 3513 .mode = 0644, 3514 .proc_handler = proc_dointvec_jiffies, 3515 }, 3516 { 3517 .procname = "redirect_load", 3518 .data = &ip_rt_redirect_load, 3519 .maxlen = sizeof(int), 3520 .mode = 0644, 3521 .proc_handler = proc_dointvec, 3522 }, 3523 { 3524 .procname = "redirect_number", 3525 .data = &ip_rt_redirect_number, 3526 .maxlen = sizeof(int), 3527 .mode = 0644, 3528 .proc_handler = proc_dointvec, 3529 }, 3530 { 3531 .procname = "redirect_silence", 3532 .data = &ip_rt_redirect_silence, 3533 .maxlen = sizeof(int), 3534 .mode = 0644, 3535 .proc_handler = proc_dointvec, 3536 }, 3537 { 3538 .procname = "error_cost", 3539 .data = &ip_rt_error_cost, 3540 .maxlen = sizeof(int), 3541 .mode = 0644, 3542 .proc_handler = proc_dointvec, 3543 }, 3544 { 3545 .procname = "error_burst", 3546 .data = &ip_rt_error_burst, 3547 .maxlen = sizeof(int), 3548 .mode = 0644, 3549 .proc_handler = proc_dointvec, 3550 }, 3551 { 3552 .procname = "gc_elasticity", 3553 .data = &ip_rt_gc_elasticity, 3554 .maxlen = sizeof(int), 3555 .mode = 0644, 3556 .proc_handler = proc_dointvec, 3557 }, 3558 }; 3559 3560 static const char ipv4_route_flush_procname[] = "flush"; 3561 3562 static struct ctl_table ipv4_route_netns_table[] = { 3563 { 3564 .procname = ipv4_route_flush_procname, 3565 .maxlen = sizeof(int), 3566 .mode = 0200, 3567 .proc_handler = ipv4_sysctl_rtcache_flush, 3568 }, 3569 { 3570 .procname = "min_pmtu", 3571 .data = &init_net.ipv4.ip_rt_min_pmtu, 3572 .maxlen = sizeof(int), 3573 .mode = 0644, 3574 .proc_handler = proc_dointvec_minmax, 3575 .extra1 = &ip_min_valid_pmtu, 3576 }, 3577 { 3578 .procname = "mtu_expires", 3579 .data = &init_net.ipv4.ip_rt_mtu_expires, 3580 .maxlen = sizeof(int), 3581 .mode = 0644, 3582 .proc_handler = proc_dointvec_jiffies, 3583 }, 3584 { 3585 .procname = "min_adv_mss", 3586 .data = &init_net.ipv4.ip_rt_min_advmss, 3587 .maxlen = sizeof(int), 3588 .mode = 0644, 3589 .proc_handler = proc_dointvec, 3590 }, 3591 }; 3592 3593 static __net_init int sysctl_route_net_init(struct net *net) 3594 { 3595 struct ctl_table *tbl; 3596 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3597 3598 tbl = ipv4_route_netns_table; 3599 if (!net_eq(net, &init_net)) { 3600 int i; 3601 3602 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3603 if (!tbl) 3604 goto err_dup; 3605 3606 /* Don't export non-whitelisted sysctls to unprivileged users */ 3607 if (net->user_ns != &init_user_ns) { 3608 if (tbl[0].procname != ipv4_route_flush_procname) 3609 table_size = 0; 3610 } 3611 3612 /* Update the variables to point into the current struct net 3613 * except for the first element flush 3614 */ 3615 for (i = 1; i < table_size; i++) 3616 tbl[i].data += (void *)net - (void *)&init_net; 3617 } 3618 tbl[0].extra1 = net; 3619 3620 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3621 tbl, table_size); 3622 if (!net->ipv4.route_hdr) 3623 goto err_reg; 3624 return 0; 3625 3626 err_reg: 3627 if (tbl != ipv4_route_netns_table) 3628 kfree(tbl); 3629 err_dup: 3630 return -ENOMEM; 3631 } 3632 3633 static __net_exit void sysctl_route_net_exit(struct net *net) 3634 { 3635 const struct ctl_table *tbl; 3636 3637 tbl = net->ipv4.route_hdr->ctl_table_arg; 3638 unregister_net_sysctl_table(net->ipv4.route_hdr); 3639 BUG_ON(tbl == ipv4_route_netns_table); 3640 kfree(tbl); 3641 } 3642 3643 static __net_initdata struct pernet_operations sysctl_route_ops = { 3644 .init = sysctl_route_net_init, 3645 .exit = sysctl_route_net_exit, 3646 }; 3647 #endif 3648 3649 static __net_init int netns_ip_rt_init(struct net *net) 3650 { 3651 /* Set default value for namespaceified sysctls */ 3652 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3653 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3654 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3655 return 0; 3656 } 3657 3658 static struct pernet_operations __net_initdata ip_rt_ops = { 3659 .init = netns_ip_rt_init, 3660 }; 3661 3662 static __net_init int rt_genid_init(struct net *net) 3663 { 3664 atomic_set(&net->ipv4.rt_genid, 0); 3665 atomic_set(&net->fnhe_genid, 0); 3666 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3667 return 0; 3668 } 3669 3670 static __net_initdata struct pernet_operations rt_genid_ops = { 3671 .init = rt_genid_init, 3672 }; 3673 3674 static int __net_init ipv4_inetpeer_init(struct net *net) 3675 { 3676 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3677 3678 if (!bp) 3679 return -ENOMEM; 3680 inet_peer_base_init(bp); 3681 net->ipv4.peers = bp; 3682 return 0; 3683 } 3684 3685 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3686 { 3687 struct inet_peer_base *bp = net->ipv4.peers; 3688 3689 net->ipv4.peers = NULL; 3690 inetpeer_invalidate_tree(bp); 3691 kfree(bp); 3692 } 3693 3694 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3695 .init = ipv4_inetpeer_init, 3696 .exit = ipv4_inetpeer_exit, 3697 }; 3698 3699 #ifdef CONFIG_IP_ROUTE_CLASSID 3700 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3701 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3702 3703 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3704 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3705 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3706 }; 3707 3708 int __init ip_rt_init(void) 3709 { 3710 void *idents_hash; 3711 int cpu; 3712 3713 /* For modern hosts, this will use 2 MB of memory */ 3714 idents_hash = alloc_large_system_hash("IP idents", 3715 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3716 0, 3717 16, /* one bucket per 64 KB */ 3718 HASH_ZERO, 3719 NULL, 3720 &ip_idents_mask, 3721 2048, 3722 256*1024); 3723 3724 ip_idents = idents_hash; 3725 3726 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3727 3728 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3729 3730 for_each_possible_cpu(cpu) { 3731 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3732 3733 INIT_LIST_HEAD(&ul->head); 3734 spin_lock_init(&ul->lock); 3735 } 3736 #ifdef CONFIG_IP_ROUTE_CLASSID 3737 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3738 if (!ip_rt_acct) 3739 panic("IP: failed to allocate ip_rt_acct\n"); 3740 #endif 3741 3742 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3743 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3744 3745 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3746 3747 if (dst_entries_init(&ipv4_dst_ops) < 0) 3748 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3749 3750 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3751 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3752 3753 ipv4_dst_ops.gc_thresh = ~0; 3754 ip_rt_max_size = INT_MAX; 3755 3756 devinet_init(); 3757 ip_fib_init(); 3758 3759 if (ip_rt_proc_init()) 3760 pr_err("Unable to create route proc files\n"); 3761 #ifdef CONFIG_XFRM 3762 xfrm_init(); 3763 xfrm4_init(); 3764 #endif 3765 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3766 3767 #ifdef CONFIG_SYSCTL 3768 register_pernet_subsys(&sysctl_route_ops); 3769 #endif 3770 register_pernet_subsys(&ip_rt_ops); 3771 register_pernet_subsys(&rt_genid_ops); 3772 register_pernet_subsys(&ipv4_inetpeer_ops); 3773 return 0; 3774 } 3775 3776 #ifdef CONFIG_SYSCTL 3777 /* 3778 * We really need to sanitize the damn ipv4 init order, then all 3779 * this nonsense will go away. 3780 */ 3781 void __init ip_static_sysctl_init(void) 3782 { 3783 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3784 } 3785 #endif 3786