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/uaccess.h> 65 #include <linux/bitops.h> 66 #include <linux/types.h> 67 #include <linux/kernel.h> 68 #include <linux/mm.h> 69 #include <linux/memblock.h> 70 #include <linux/string.h> 71 #include <linux/socket.h> 72 #include <linux/sockios.h> 73 #include <linux/errno.h> 74 #include <linux/in.h> 75 #include <linux/inet.h> 76 #include <linux/netdevice.h> 77 #include <linux/proc_fs.h> 78 #include <linux/init.h> 79 #include <linux/skbuff.h> 80 #include <linux/inetdevice.h> 81 #include <linux/igmp.h> 82 #include <linux/pkt_sched.h> 83 #include <linux/mroute.h> 84 #include <linux/netfilter_ipv4.h> 85 #include <linux/random.h> 86 #include <linux/rcupdate.h> 87 #include <linux/times.h> 88 #include <linux/slab.h> 89 #include <linux/jhash.h> 90 #include <net/dst.h> 91 #include <net/dst_metadata.h> 92 #include <net/net_namespace.h> 93 #include <net/protocol.h> 94 #include <net/ip.h> 95 #include <net/route.h> 96 #include <net/inetpeer.h> 97 #include <net/sock.h> 98 #include <net/ip_fib.h> 99 #include <net/nexthop.h> 100 #include <net/arp.h> 101 #include <net/tcp.h> 102 #include <net/icmp.h> 103 #include <net/xfrm.h> 104 #include <net/lwtunnel.h> 105 #include <net/netevent.h> 106 #include <net/rtnetlink.h> 107 #ifdef CONFIG_SYSCTL 108 #include <linux/sysctl.h> 109 #endif 110 #include <net/secure_seq.h> 111 #include <net/ip_tunnels.h> 112 #include <net/l3mdev.h> 113 114 #include "fib_lookup.h" 115 116 #define RT_FL_TOS(oldflp4) \ 117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 118 119 #define RT_GC_TIMEOUT (300*HZ) 120 121 static int ip_rt_max_size; 122 static int ip_rt_redirect_number __read_mostly = 9; 123 static int ip_rt_redirect_load __read_mostly = HZ / 50; 124 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 125 static int ip_rt_error_cost __read_mostly = HZ; 126 static int ip_rt_error_burst __read_mostly = 5 * HZ; 127 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 128 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 129 static int ip_rt_min_advmss __read_mostly = 256; 130 131 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 132 133 /* 134 * Interface to generic destination cache. 135 */ 136 137 INDIRECT_CALLABLE_SCOPE 138 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 140 INDIRECT_CALLABLE_SCOPE 141 unsigned int ipv4_mtu(const struct dst_entry *dst); 142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 143 static void ipv4_link_failure(struct sk_buff *skb); 144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 145 struct sk_buff *skb, u32 mtu, 146 bool confirm_neigh); 147 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 148 struct sk_buff *skb); 149 static void ipv4_dst_destroy(struct dst_entry *dst); 150 151 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 152 { 153 WARN_ON(1); 154 return NULL; 155 } 156 157 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 158 struct sk_buff *skb, 159 const void *daddr); 160 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 161 162 static struct dst_ops ipv4_dst_ops = { 163 .family = AF_INET, 164 .check = ipv4_dst_check, 165 .default_advmss = ipv4_default_advmss, 166 .mtu = ipv4_mtu, 167 .cow_metrics = ipv4_cow_metrics, 168 .destroy = ipv4_dst_destroy, 169 .negative_advice = ipv4_negative_advice, 170 .link_failure = ipv4_link_failure, 171 .update_pmtu = ip_rt_update_pmtu, 172 .redirect = ip_do_redirect, 173 .local_out = __ip_local_out, 174 .neigh_lookup = ipv4_neigh_lookup, 175 .confirm_neigh = ipv4_confirm_neigh, 176 }; 177 178 #define ECN_OR_COST(class) TC_PRIO_##class 179 180 const __u8 ip_tos2prio[16] = { 181 TC_PRIO_BESTEFFORT, 182 ECN_OR_COST(BESTEFFORT), 183 TC_PRIO_BESTEFFORT, 184 ECN_OR_COST(BESTEFFORT), 185 TC_PRIO_BULK, 186 ECN_OR_COST(BULK), 187 TC_PRIO_BULK, 188 ECN_OR_COST(BULK), 189 TC_PRIO_INTERACTIVE, 190 ECN_OR_COST(INTERACTIVE), 191 TC_PRIO_INTERACTIVE, 192 ECN_OR_COST(INTERACTIVE), 193 TC_PRIO_INTERACTIVE_BULK, 194 ECN_OR_COST(INTERACTIVE_BULK), 195 TC_PRIO_INTERACTIVE_BULK, 196 ECN_OR_COST(INTERACTIVE_BULK) 197 }; 198 EXPORT_SYMBOL(ip_tos2prio); 199 200 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 201 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 202 203 #ifdef CONFIG_PROC_FS 204 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 205 { 206 if (*pos) 207 return NULL; 208 return SEQ_START_TOKEN; 209 } 210 211 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 212 { 213 ++*pos; 214 return NULL; 215 } 216 217 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 218 { 219 } 220 221 static int rt_cache_seq_show(struct seq_file *seq, void *v) 222 { 223 if (v == SEQ_START_TOKEN) 224 seq_printf(seq, "%-127s\n", 225 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 226 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 227 "HHUptod\tSpecDst"); 228 return 0; 229 } 230 231 static const struct seq_operations rt_cache_seq_ops = { 232 .start = rt_cache_seq_start, 233 .next = rt_cache_seq_next, 234 .stop = rt_cache_seq_stop, 235 .show = rt_cache_seq_show, 236 }; 237 238 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 239 { 240 int cpu; 241 242 if (*pos == 0) 243 return SEQ_START_TOKEN; 244 245 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 246 if (!cpu_possible(cpu)) 247 continue; 248 *pos = cpu+1; 249 return &per_cpu(rt_cache_stat, cpu); 250 } 251 return NULL; 252 } 253 254 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 255 { 256 int cpu; 257 258 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 259 if (!cpu_possible(cpu)) 260 continue; 261 *pos = cpu+1; 262 return &per_cpu(rt_cache_stat, cpu); 263 } 264 (*pos)++; 265 return NULL; 266 267 } 268 269 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 270 { 271 272 } 273 274 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 275 { 276 struct rt_cache_stat *st = v; 277 278 if (v == SEQ_START_TOKEN) { 279 seq_printf(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"); 280 return 0; 281 } 282 283 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 284 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 285 dst_entries_get_slow(&ipv4_dst_ops), 286 0, /* st->in_hit */ 287 st->in_slow_tot, 288 st->in_slow_mc, 289 st->in_no_route, 290 st->in_brd, 291 st->in_martian_dst, 292 st->in_martian_src, 293 294 0, /* st->out_hit */ 295 st->out_slow_tot, 296 st->out_slow_mc, 297 298 0, /* st->gc_total */ 299 0, /* st->gc_ignored */ 300 0, /* st->gc_goal_miss */ 301 0, /* st->gc_dst_overflow */ 302 0, /* st->in_hlist_search */ 303 0 /* st->out_hlist_search */ 304 ); 305 return 0; 306 } 307 308 static const struct seq_operations rt_cpu_seq_ops = { 309 .start = rt_cpu_seq_start, 310 .next = rt_cpu_seq_next, 311 .stop = rt_cpu_seq_stop, 312 .show = rt_cpu_seq_show, 313 }; 314 315 #ifdef CONFIG_IP_ROUTE_CLASSID 316 static int rt_acct_proc_show(struct seq_file *m, void *v) 317 { 318 struct ip_rt_acct *dst, *src; 319 unsigned int i, j; 320 321 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 322 if (!dst) 323 return -ENOMEM; 324 325 for_each_possible_cpu(i) { 326 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 327 for (j = 0; j < 256; j++) { 328 dst[j].o_bytes += src[j].o_bytes; 329 dst[j].o_packets += src[j].o_packets; 330 dst[j].i_bytes += src[j].i_bytes; 331 dst[j].i_packets += src[j].i_packets; 332 } 333 } 334 335 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 336 kfree(dst); 337 return 0; 338 } 339 #endif 340 341 static int __net_init ip_rt_do_proc_init(struct net *net) 342 { 343 struct proc_dir_entry *pde; 344 345 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 346 &rt_cache_seq_ops); 347 if (!pde) 348 goto err1; 349 350 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 351 &rt_cpu_seq_ops); 352 if (!pde) 353 goto err2; 354 355 #ifdef CONFIG_IP_ROUTE_CLASSID 356 pde = proc_create_single("rt_acct", 0, net->proc_net, 357 rt_acct_proc_show); 358 if (!pde) 359 goto err3; 360 #endif 361 return 0; 362 363 #ifdef CONFIG_IP_ROUTE_CLASSID 364 err3: 365 remove_proc_entry("rt_cache", net->proc_net_stat); 366 #endif 367 err2: 368 remove_proc_entry("rt_cache", net->proc_net); 369 err1: 370 return -ENOMEM; 371 } 372 373 static void __net_exit ip_rt_do_proc_exit(struct net *net) 374 { 375 remove_proc_entry("rt_cache", net->proc_net_stat); 376 remove_proc_entry("rt_cache", net->proc_net); 377 #ifdef CONFIG_IP_ROUTE_CLASSID 378 remove_proc_entry("rt_acct", net->proc_net); 379 #endif 380 } 381 382 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 383 .init = ip_rt_do_proc_init, 384 .exit = ip_rt_do_proc_exit, 385 }; 386 387 static int __init ip_rt_proc_init(void) 388 { 389 return register_pernet_subsys(&ip_rt_proc_ops); 390 } 391 392 #else 393 static inline int ip_rt_proc_init(void) 394 { 395 return 0; 396 } 397 #endif /* CONFIG_PROC_FS */ 398 399 static inline bool rt_is_expired(const struct rtable *rth) 400 { 401 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 402 } 403 404 void rt_cache_flush(struct net *net) 405 { 406 rt_genid_bump_ipv4(net); 407 } 408 409 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 410 struct sk_buff *skb, 411 const void *daddr) 412 { 413 const struct rtable *rt = container_of(dst, struct rtable, dst); 414 struct net_device *dev = dst->dev; 415 struct neighbour *n; 416 417 rcu_read_lock_bh(); 418 419 if (likely(rt->rt_gw_family == AF_INET)) { 420 n = ip_neigh_gw4(dev, rt->rt_gw4); 421 } else if (rt->rt_gw_family == AF_INET6) { 422 n = ip_neigh_gw6(dev, &rt->rt_gw6); 423 } else { 424 __be32 pkey; 425 426 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 427 n = ip_neigh_gw4(dev, pkey); 428 } 429 430 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 431 n = NULL; 432 433 rcu_read_unlock_bh(); 434 435 return n; 436 } 437 438 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 439 { 440 const struct rtable *rt = container_of(dst, struct rtable, dst); 441 struct net_device *dev = dst->dev; 442 const __be32 *pkey = daddr; 443 444 if (rt->rt_gw_family == AF_INET) { 445 pkey = (const __be32 *)&rt->rt_gw4; 446 } else if (rt->rt_gw_family == AF_INET6) { 447 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 448 } else if (!daddr || 449 (rt->rt_flags & 450 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 451 return; 452 } 453 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 454 } 455 456 /* Hash tables of size 2048..262144 depending on RAM size. 457 * Each bucket uses 8 bytes. 458 */ 459 static u32 ip_idents_mask __read_mostly; 460 static atomic_t *ip_idents __read_mostly; 461 static u32 *ip_tstamps __read_mostly; 462 463 /* In order to protect privacy, we add a perturbation to identifiers 464 * if one generator is seldom used. This makes hard for an attacker 465 * to infer how many packets were sent between two points in time. 466 */ 467 u32 ip_idents_reserve(u32 hash, int segs) 468 { 469 u32 bucket, old, now = (u32)jiffies; 470 atomic_t *p_id; 471 u32 *p_tstamp; 472 u32 delta = 0; 473 474 bucket = hash & ip_idents_mask; 475 p_tstamp = ip_tstamps + bucket; 476 p_id = ip_idents + bucket; 477 old = READ_ONCE(*p_tstamp); 478 479 if (old != now && cmpxchg(p_tstamp, old, now) == old) 480 delta = prandom_u32_max(now - old); 481 482 /* If UBSAN reports an error there, please make sure your compiler 483 * supports -fno-strict-overflow before reporting it that was a bug 484 * in UBSAN, and it has been fixed in GCC-8. 485 */ 486 return atomic_add_return(segs + delta, p_id) - segs; 487 } 488 EXPORT_SYMBOL(ip_idents_reserve); 489 490 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 491 { 492 u32 hash, id; 493 494 /* Note the following code is not safe, but this is okay. */ 495 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 496 get_random_bytes(&net->ipv4.ip_id_key, 497 sizeof(net->ipv4.ip_id_key)); 498 499 hash = siphash_3u32((__force u32)iph->daddr, 500 (__force u32)iph->saddr, 501 iph->protocol, 502 &net->ipv4.ip_id_key); 503 id = ip_idents_reserve(hash, segs); 504 iph->id = htons(id); 505 } 506 EXPORT_SYMBOL(__ip_select_ident); 507 508 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 509 const struct sock *sk, 510 const struct iphdr *iph, 511 int oif, u8 tos, 512 u8 prot, u32 mark, int flow_flags) 513 { 514 if (sk) { 515 const struct inet_sock *inet = inet_sk(sk); 516 517 oif = sk->sk_bound_dev_if; 518 mark = sk->sk_mark; 519 tos = RT_CONN_FLAGS(sk); 520 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 521 } 522 flowi4_init_output(fl4, oif, mark, tos, 523 RT_SCOPE_UNIVERSE, prot, 524 flow_flags, 525 iph->daddr, iph->saddr, 0, 0, 526 sock_net_uid(net, sk)); 527 } 528 529 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 530 const struct sock *sk) 531 { 532 const struct net *net = dev_net(skb->dev); 533 const struct iphdr *iph = ip_hdr(skb); 534 int oif = skb->dev->ifindex; 535 u8 tos = RT_TOS(iph->tos); 536 u8 prot = iph->protocol; 537 u32 mark = skb->mark; 538 539 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 540 } 541 542 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 543 { 544 const struct inet_sock *inet = inet_sk(sk); 545 const struct ip_options_rcu *inet_opt; 546 __be32 daddr = inet->inet_daddr; 547 548 rcu_read_lock(); 549 inet_opt = rcu_dereference(inet->inet_opt); 550 if (inet_opt && inet_opt->opt.srr) 551 daddr = inet_opt->opt.faddr; 552 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 553 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 554 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 555 inet_sk_flowi_flags(sk), 556 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 557 rcu_read_unlock(); 558 } 559 560 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 561 const struct sk_buff *skb) 562 { 563 if (skb) 564 build_skb_flow_key(fl4, skb, sk); 565 else 566 build_sk_flow_key(fl4, sk); 567 } 568 569 static DEFINE_SPINLOCK(fnhe_lock); 570 571 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 572 { 573 struct rtable *rt; 574 575 rt = rcu_dereference(fnhe->fnhe_rth_input); 576 if (rt) { 577 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 578 dst_dev_put(&rt->dst); 579 dst_release(&rt->dst); 580 } 581 rt = rcu_dereference(fnhe->fnhe_rth_output); 582 if (rt) { 583 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 584 dst_dev_put(&rt->dst); 585 dst_release(&rt->dst); 586 } 587 } 588 589 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 590 { 591 struct fib_nh_exception *fnhe, *oldest; 592 593 oldest = rcu_dereference(hash->chain); 594 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 595 fnhe = rcu_dereference(fnhe->fnhe_next)) { 596 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 597 oldest = fnhe; 598 } 599 fnhe_flush_routes(oldest); 600 return oldest; 601 } 602 603 static inline u32 fnhe_hashfun(__be32 daddr) 604 { 605 static u32 fnhe_hashrnd __read_mostly; 606 u32 hval; 607 608 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 609 hval = jhash_1word((__force u32)daddr, fnhe_hashrnd); 610 return hash_32(hval, FNHE_HASH_SHIFT); 611 } 612 613 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 614 { 615 rt->rt_pmtu = fnhe->fnhe_pmtu; 616 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 617 rt->dst.expires = fnhe->fnhe_expires; 618 619 if (fnhe->fnhe_gw) { 620 rt->rt_flags |= RTCF_REDIRECTED; 621 rt->rt_uses_gateway = 1; 622 rt->rt_gw_family = AF_INET; 623 rt->rt_gw4 = fnhe->fnhe_gw; 624 } 625 } 626 627 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 628 __be32 gw, u32 pmtu, bool lock, 629 unsigned long expires) 630 { 631 struct fnhe_hash_bucket *hash; 632 struct fib_nh_exception *fnhe; 633 struct rtable *rt; 634 u32 genid, hval; 635 unsigned int i; 636 int depth; 637 638 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 639 hval = fnhe_hashfun(daddr); 640 641 spin_lock_bh(&fnhe_lock); 642 643 hash = rcu_dereference(nhc->nhc_exceptions); 644 if (!hash) { 645 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 646 if (!hash) 647 goto out_unlock; 648 rcu_assign_pointer(nhc->nhc_exceptions, hash); 649 } 650 651 hash += hval; 652 653 depth = 0; 654 for (fnhe = rcu_dereference(hash->chain); fnhe; 655 fnhe = rcu_dereference(fnhe->fnhe_next)) { 656 if (fnhe->fnhe_daddr == daddr) 657 break; 658 depth++; 659 } 660 661 if (fnhe) { 662 if (fnhe->fnhe_genid != genid) 663 fnhe->fnhe_genid = genid; 664 if (gw) 665 fnhe->fnhe_gw = gw; 666 if (pmtu) { 667 fnhe->fnhe_pmtu = pmtu; 668 fnhe->fnhe_mtu_locked = lock; 669 } 670 fnhe->fnhe_expires = max(1UL, expires); 671 /* Update all cached dsts too */ 672 rt = rcu_dereference(fnhe->fnhe_rth_input); 673 if (rt) 674 fill_route_from_fnhe(rt, fnhe); 675 rt = rcu_dereference(fnhe->fnhe_rth_output); 676 if (rt) 677 fill_route_from_fnhe(rt, fnhe); 678 } else { 679 if (depth > FNHE_RECLAIM_DEPTH) 680 fnhe = fnhe_oldest(hash); 681 else { 682 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 683 if (!fnhe) 684 goto out_unlock; 685 686 fnhe->fnhe_next = hash->chain; 687 rcu_assign_pointer(hash->chain, fnhe); 688 } 689 fnhe->fnhe_genid = genid; 690 fnhe->fnhe_daddr = daddr; 691 fnhe->fnhe_gw = gw; 692 fnhe->fnhe_pmtu = pmtu; 693 fnhe->fnhe_mtu_locked = lock; 694 fnhe->fnhe_expires = max(1UL, expires); 695 696 /* Exception created; mark the cached routes for the nexthop 697 * stale, so anyone caching it rechecks if this exception 698 * applies to them. 699 */ 700 rt = rcu_dereference(nhc->nhc_rth_input); 701 if (rt) 702 rt->dst.obsolete = DST_OBSOLETE_KILL; 703 704 for_each_possible_cpu(i) { 705 struct rtable __rcu **prt; 706 707 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 708 rt = rcu_dereference(*prt); 709 if (rt) 710 rt->dst.obsolete = DST_OBSOLETE_KILL; 711 } 712 } 713 714 fnhe->fnhe_stamp = jiffies; 715 716 out_unlock: 717 spin_unlock_bh(&fnhe_lock); 718 } 719 720 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 721 bool kill_route) 722 { 723 __be32 new_gw = icmp_hdr(skb)->un.gateway; 724 __be32 old_gw = ip_hdr(skb)->saddr; 725 struct net_device *dev = skb->dev; 726 struct in_device *in_dev; 727 struct fib_result res; 728 struct neighbour *n; 729 struct net *net; 730 731 switch (icmp_hdr(skb)->code & 7) { 732 case ICMP_REDIR_NET: 733 case ICMP_REDIR_NETTOS: 734 case ICMP_REDIR_HOST: 735 case ICMP_REDIR_HOSTTOS: 736 break; 737 738 default: 739 return; 740 } 741 742 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 743 return; 744 745 in_dev = __in_dev_get_rcu(dev); 746 if (!in_dev) 747 return; 748 749 net = dev_net(dev); 750 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 751 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 752 ipv4_is_zeronet(new_gw)) 753 goto reject_redirect; 754 755 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 756 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 757 goto reject_redirect; 758 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 759 goto reject_redirect; 760 } else { 761 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 762 goto reject_redirect; 763 } 764 765 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 766 if (!n) 767 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 768 if (!IS_ERR(n)) { 769 if (!(n->nud_state & NUD_VALID)) { 770 neigh_event_send(n, NULL); 771 } else { 772 if (fib_lookup(net, fl4, &res, 0) == 0) { 773 struct fib_nh_common *nhc; 774 775 fib_select_path(net, &res, fl4, skb); 776 nhc = FIB_RES_NHC(res); 777 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 778 0, false, 779 jiffies + ip_rt_gc_timeout); 780 } 781 if (kill_route) 782 rt->dst.obsolete = DST_OBSOLETE_KILL; 783 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 784 } 785 neigh_release(n); 786 } 787 return; 788 789 reject_redirect: 790 #ifdef CONFIG_IP_ROUTE_VERBOSE 791 if (IN_DEV_LOG_MARTIANS(in_dev)) { 792 const struct iphdr *iph = (const struct iphdr *) skb->data; 793 __be32 daddr = iph->daddr; 794 __be32 saddr = iph->saddr; 795 796 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 797 " Advised path = %pI4 -> %pI4\n", 798 &old_gw, dev->name, &new_gw, 799 &saddr, &daddr); 800 } 801 #endif 802 ; 803 } 804 805 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 806 { 807 struct rtable *rt; 808 struct flowi4 fl4; 809 const struct iphdr *iph = (const struct iphdr *) skb->data; 810 struct net *net = dev_net(skb->dev); 811 int oif = skb->dev->ifindex; 812 u8 tos = RT_TOS(iph->tos); 813 u8 prot = iph->protocol; 814 u32 mark = skb->mark; 815 816 rt = (struct rtable *) dst; 817 818 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 819 __ip_do_redirect(rt, skb, &fl4, true); 820 } 821 822 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 823 { 824 struct rtable *rt = (struct rtable *)dst; 825 struct dst_entry *ret = dst; 826 827 if (rt) { 828 if (dst->obsolete > 0) { 829 ip_rt_put(rt); 830 ret = NULL; 831 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 832 rt->dst.expires) { 833 ip_rt_put(rt); 834 ret = NULL; 835 } 836 } 837 return ret; 838 } 839 840 /* 841 * Algorithm: 842 * 1. The first ip_rt_redirect_number redirects are sent 843 * with exponential backoff, then we stop sending them at all, 844 * assuming that the host ignores our redirects. 845 * 2. If we did not see packets requiring redirects 846 * during ip_rt_redirect_silence, we assume that the host 847 * forgot redirected route and start to send redirects again. 848 * 849 * This algorithm is much cheaper and more intelligent than dumb load limiting 850 * in icmp.c. 851 * 852 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 853 * and "frag. need" (breaks PMTU discovery) in icmp.c. 854 */ 855 856 void ip_rt_send_redirect(struct sk_buff *skb) 857 { 858 struct rtable *rt = skb_rtable(skb); 859 struct in_device *in_dev; 860 struct inet_peer *peer; 861 struct net *net; 862 int log_martians; 863 int vif; 864 865 rcu_read_lock(); 866 in_dev = __in_dev_get_rcu(rt->dst.dev); 867 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 868 rcu_read_unlock(); 869 return; 870 } 871 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 872 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 873 rcu_read_unlock(); 874 875 net = dev_net(rt->dst.dev); 876 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 877 if (!peer) { 878 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 879 rt_nexthop(rt, ip_hdr(skb)->daddr)); 880 return; 881 } 882 883 /* No redirected packets during ip_rt_redirect_silence; 884 * reset the algorithm. 885 */ 886 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 887 peer->rate_tokens = 0; 888 peer->n_redirects = 0; 889 } 890 891 /* Too many ignored redirects; do not send anything 892 * set dst.rate_last to the last seen redirected packet. 893 */ 894 if (peer->n_redirects >= ip_rt_redirect_number) { 895 peer->rate_last = jiffies; 896 goto out_put_peer; 897 } 898 899 /* Check for load limit; set rate_last to the latest sent 900 * redirect. 901 */ 902 if (peer->n_redirects == 0 || 903 time_after(jiffies, 904 (peer->rate_last + 905 (ip_rt_redirect_load << peer->n_redirects)))) { 906 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 907 908 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 909 peer->rate_last = jiffies; 910 ++peer->n_redirects; 911 #ifdef CONFIG_IP_ROUTE_VERBOSE 912 if (log_martians && 913 peer->n_redirects == ip_rt_redirect_number) 914 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 915 &ip_hdr(skb)->saddr, inet_iif(skb), 916 &ip_hdr(skb)->daddr, &gw); 917 #endif 918 } 919 out_put_peer: 920 inet_putpeer(peer); 921 } 922 923 static int ip_error(struct sk_buff *skb) 924 { 925 struct rtable *rt = skb_rtable(skb); 926 struct net_device *dev = skb->dev; 927 struct in_device *in_dev; 928 struct inet_peer *peer; 929 unsigned long now; 930 struct net *net; 931 bool send; 932 int code; 933 934 if (netif_is_l3_master(skb->dev)) { 935 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 936 if (!dev) 937 goto out; 938 } 939 940 in_dev = __in_dev_get_rcu(dev); 941 942 /* IP on this device is disabled. */ 943 if (!in_dev) 944 goto out; 945 946 net = dev_net(rt->dst.dev); 947 if (!IN_DEV_FORWARD(in_dev)) { 948 switch (rt->dst.error) { 949 case EHOSTUNREACH: 950 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 951 break; 952 953 case ENETUNREACH: 954 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 955 break; 956 } 957 goto out; 958 } 959 960 switch (rt->dst.error) { 961 case EINVAL: 962 default: 963 goto out; 964 case EHOSTUNREACH: 965 code = ICMP_HOST_UNREACH; 966 break; 967 case ENETUNREACH: 968 code = ICMP_NET_UNREACH; 969 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 970 break; 971 case EACCES: 972 code = ICMP_PKT_FILTERED; 973 break; 974 } 975 976 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 977 l3mdev_master_ifindex(skb->dev), 1); 978 979 send = true; 980 if (peer) { 981 now = jiffies; 982 peer->rate_tokens += now - peer->rate_last; 983 if (peer->rate_tokens > ip_rt_error_burst) 984 peer->rate_tokens = ip_rt_error_burst; 985 peer->rate_last = now; 986 if (peer->rate_tokens >= ip_rt_error_cost) 987 peer->rate_tokens -= ip_rt_error_cost; 988 else 989 send = false; 990 inet_putpeer(peer); 991 } 992 if (send) 993 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 994 995 out: kfree_skb(skb); 996 return 0; 997 } 998 999 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1000 { 1001 struct dst_entry *dst = &rt->dst; 1002 struct net *net = dev_net(dst->dev); 1003 struct fib_result res; 1004 bool lock = false; 1005 u32 old_mtu; 1006 1007 if (ip_mtu_locked(dst)) 1008 return; 1009 1010 old_mtu = ipv4_mtu(dst); 1011 if (old_mtu < mtu) 1012 return; 1013 1014 if (mtu < ip_rt_min_pmtu) { 1015 lock = true; 1016 mtu = min(old_mtu, ip_rt_min_pmtu); 1017 } 1018 1019 if (rt->rt_pmtu == mtu && !lock && 1020 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 1021 return; 1022 1023 rcu_read_lock(); 1024 if (fib_lookup(net, fl4, &res, 0) == 0) { 1025 struct fib_nh_common *nhc; 1026 1027 fib_select_path(net, &res, fl4, NULL); 1028 nhc = FIB_RES_NHC(res); 1029 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1030 jiffies + ip_rt_mtu_expires); 1031 } 1032 rcu_read_unlock(); 1033 } 1034 1035 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1036 struct sk_buff *skb, u32 mtu, 1037 bool confirm_neigh) 1038 { 1039 struct rtable *rt = (struct rtable *) dst; 1040 struct flowi4 fl4; 1041 1042 ip_rt_build_flow_key(&fl4, sk, skb); 1043 1044 /* Don't make lookup fail for bridged encapsulations */ 1045 if (skb && netif_is_any_bridge_port(skb->dev)) 1046 fl4.flowi4_oif = 0; 1047 1048 __ip_rt_update_pmtu(rt, &fl4, mtu); 1049 } 1050 1051 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1052 int oif, u8 protocol) 1053 { 1054 const struct iphdr *iph = (const struct iphdr *)skb->data; 1055 struct flowi4 fl4; 1056 struct rtable *rt; 1057 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1058 1059 __build_flow_key(net, &fl4, NULL, iph, oif, 1060 RT_TOS(iph->tos), protocol, mark, 0); 1061 rt = __ip_route_output_key(net, &fl4); 1062 if (!IS_ERR(rt)) { 1063 __ip_rt_update_pmtu(rt, &fl4, mtu); 1064 ip_rt_put(rt); 1065 } 1066 } 1067 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1068 1069 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1070 { 1071 const struct iphdr *iph = (const struct iphdr *)skb->data; 1072 struct flowi4 fl4; 1073 struct rtable *rt; 1074 1075 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1076 1077 if (!fl4.flowi4_mark) 1078 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1079 1080 rt = __ip_route_output_key(sock_net(sk), &fl4); 1081 if (!IS_ERR(rt)) { 1082 __ip_rt_update_pmtu(rt, &fl4, mtu); 1083 ip_rt_put(rt); 1084 } 1085 } 1086 1087 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1088 { 1089 const struct iphdr *iph = (const struct iphdr *)skb->data; 1090 struct flowi4 fl4; 1091 struct rtable *rt; 1092 struct dst_entry *odst = NULL; 1093 bool new = false; 1094 struct net *net = sock_net(sk); 1095 1096 bh_lock_sock(sk); 1097 1098 if (!ip_sk_accept_pmtu(sk)) 1099 goto out; 1100 1101 odst = sk_dst_get(sk); 1102 1103 if (sock_owned_by_user(sk) || !odst) { 1104 __ipv4_sk_update_pmtu(skb, sk, mtu); 1105 goto out; 1106 } 1107 1108 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1109 1110 rt = (struct rtable *)odst; 1111 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1112 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1113 if (IS_ERR(rt)) 1114 goto out; 1115 1116 new = true; 1117 } 1118 1119 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu); 1120 1121 if (!dst_check(&rt->dst, 0)) { 1122 if (new) 1123 dst_release(&rt->dst); 1124 1125 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1126 if (IS_ERR(rt)) 1127 goto out; 1128 1129 new = true; 1130 } 1131 1132 if (new) 1133 sk_dst_set(sk, &rt->dst); 1134 1135 out: 1136 bh_unlock_sock(sk); 1137 dst_release(odst); 1138 } 1139 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1140 1141 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1142 int oif, u8 protocol) 1143 { 1144 const struct iphdr *iph = (const struct iphdr *)skb->data; 1145 struct flowi4 fl4; 1146 struct rtable *rt; 1147 1148 __build_flow_key(net, &fl4, NULL, iph, oif, 1149 RT_TOS(iph->tos), protocol, 0, 0); 1150 rt = __ip_route_output_key(net, &fl4); 1151 if (!IS_ERR(rt)) { 1152 __ip_do_redirect(rt, skb, &fl4, false); 1153 ip_rt_put(rt); 1154 } 1155 } 1156 EXPORT_SYMBOL_GPL(ipv4_redirect); 1157 1158 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1159 { 1160 const struct iphdr *iph = (const struct iphdr *)skb->data; 1161 struct flowi4 fl4; 1162 struct rtable *rt; 1163 struct net *net = sock_net(sk); 1164 1165 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1166 rt = __ip_route_output_key(net, &fl4); 1167 if (!IS_ERR(rt)) { 1168 __ip_do_redirect(rt, skb, &fl4, false); 1169 ip_rt_put(rt); 1170 } 1171 } 1172 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1173 1174 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1175 u32 cookie) 1176 { 1177 struct rtable *rt = (struct rtable *) dst; 1178 1179 /* All IPV4 dsts are created with ->obsolete set to the value 1180 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1181 * into this function always. 1182 * 1183 * When a PMTU/redirect information update invalidates a route, 1184 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1185 * DST_OBSOLETE_DEAD. 1186 */ 1187 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1188 return NULL; 1189 return dst; 1190 } 1191 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1192 1193 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1194 { 1195 struct ip_options opt; 1196 int res; 1197 1198 /* Recompile ip options since IPCB may not be valid anymore. 1199 * Also check we have a reasonable ipv4 header. 1200 */ 1201 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1202 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1203 return; 1204 1205 memset(&opt, 0, sizeof(opt)); 1206 if (ip_hdr(skb)->ihl > 5) { 1207 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1208 return; 1209 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1210 1211 rcu_read_lock(); 1212 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1213 rcu_read_unlock(); 1214 1215 if (res) 1216 return; 1217 } 1218 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1219 } 1220 1221 static void ipv4_link_failure(struct sk_buff *skb) 1222 { 1223 struct rtable *rt; 1224 1225 ipv4_send_dest_unreach(skb); 1226 1227 rt = skb_rtable(skb); 1228 if (rt) 1229 dst_set_expires(&rt->dst, 0); 1230 } 1231 1232 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1233 { 1234 pr_debug("%s: %pI4 -> %pI4, %s\n", 1235 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1236 skb->dev ? skb->dev->name : "?"); 1237 kfree_skb(skb); 1238 WARN_ON(1); 1239 return 0; 1240 } 1241 1242 /* 1243 * We do not cache source address of outgoing interface, 1244 * because it is used only by IP RR, TS and SRR options, 1245 * so that it out of fast path. 1246 * 1247 * BTW remember: "addr" is allowed to be not aligned 1248 * in IP options! 1249 */ 1250 1251 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1252 { 1253 __be32 src; 1254 1255 if (rt_is_output_route(rt)) 1256 src = ip_hdr(skb)->saddr; 1257 else { 1258 struct fib_result res; 1259 struct iphdr *iph = ip_hdr(skb); 1260 struct flowi4 fl4 = { 1261 .daddr = iph->daddr, 1262 .saddr = iph->saddr, 1263 .flowi4_tos = RT_TOS(iph->tos), 1264 .flowi4_oif = rt->dst.dev->ifindex, 1265 .flowi4_iif = skb->dev->ifindex, 1266 .flowi4_mark = skb->mark, 1267 }; 1268 1269 rcu_read_lock(); 1270 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1271 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1272 else 1273 src = inet_select_addr(rt->dst.dev, 1274 rt_nexthop(rt, iph->daddr), 1275 RT_SCOPE_UNIVERSE); 1276 rcu_read_unlock(); 1277 } 1278 memcpy(addr, &src, 4); 1279 } 1280 1281 #ifdef CONFIG_IP_ROUTE_CLASSID 1282 static void set_class_tag(struct rtable *rt, u32 tag) 1283 { 1284 if (!(rt->dst.tclassid & 0xFFFF)) 1285 rt->dst.tclassid |= tag & 0xFFFF; 1286 if (!(rt->dst.tclassid & 0xFFFF0000)) 1287 rt->dst.tclassid |= tag & 0xFFFF0000; 1288 } 1289 #endif 1290 1291 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1292 { 1293 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1294 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1295 ip_rt_min_advmss); 1296 1297 return min(advmss, IPV4_MAX_PMTU - header_size); 1298 } 1299 1300 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1301 { 1302 const struct rtable *rt = (const struct rtable *)dst; 1303 unsigned int mtu = rt->rt_pmtu; 1304 1305 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1306 mtu = dst_metric_raw(dst, RTAX_MTU); 1307 1308 if (mtu) 1309 return mtu; 1310 1311 mtu = READ_ONCE(dst->dev->mtu); 1312 1313 if (unlikely(ip_mtu_locked(dst))) { 1314 if (rt->rt_uses_gateway && mtu > 576) 1315 mtu = 576; 1316 } 1317 1318 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1319 1320 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1321 } 1322 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1323 1324 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1325 { 1326 struct fnhe_hash_bucket *hash; 1327 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1328 u32 hval = fnhe_hashfun(daddr); 1329 1330 spin_lock_bh(&fnhe_lock); 1331 1332 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1333 lockdep_is_held(&fnhe_lock)); 1334 hash += hval; 1335 1336 fnhe_p = &hash->chain; 1337 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1338 while (fnhe) { 1339 if (fnhe->fnhe_daddr == daddr) { 1340 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1341 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1342 /* set fnhe_daddr to 0 to ensure it won't bind with 1343 * new dsts in rt_bind_exception(). 1344 */ 1345 fnhe->fnhe_daddr = 0; 1346 fnhe_flush_routes(fnhe); 1347 kfree_rcu(fnhe, rcu); 1348 break; 1349 } 1350 fnhe_p = &fnhe->fnhe_next; 1351 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1352 lockdep_is_held(&fnhe_lock)); 1353 } 1354 1355 spin_unlock_bh(&fnhe_lock); 1356 } 1357 1358 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1359 __be32 daddr) 1360 { 1361 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1362 struct fib_nh_exception *fnhe; 1363 u32 hval; 1364 1365 if (!hash) 1366 return NULL; 1367 1368 hval = fnhe_hashfun(daddr); 1369 1370 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1371 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1372 if (fnhe->fnhe_daddr == daddr) { 1373 if (fnhe->fnhe_expires && 1374 time_after(jiffies, fnhe->fnhe_expires)) { 1375 ip_del_fnhe(nhc, daddr); 1376 break; 1377 } 1378 return fnhe; 1379 } 1380 } 1381 return NULL; 1382 } 1383 1384 /* MTU selection: 1385 * 1. mtu on route is locked - use it 1386 * 2. mtu from nexthop exception 1387 * 3. mtu from egress device 1388 */ 1389 1390 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1391 { 1392 struct fib_nh_common *nhc = res->nhc; 1393 struct net_device *dev = nhc->nhc_dev; 1394 struct fib_info *fi = res->fi; 1395 u32 mtu = 0; 1396 1397 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1398 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1399 mtu = fi->fib_mtu; 1400 1401 if (likely(!mtu)) { 1402 struct fib_nh_exception *fnhe; 1403 1404 fnhe = find_exception(nhc, daddr); 1405 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1406 mtu = fnhe->fnhe_pmtu; 1407 } 1408 1409 if (likely(!mtu)) 1410 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1411 1412 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1413 } 1414 1415 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1416 __be32 daddr, const bool do_cache) 1417 { 1418 bool ret = false; 1419 1420 spin_lock_bh(&fnhe_lock); 1421 1422 if (daddr == fnhe->fnhe_daddr) { 1423 struct rtable __rcu **porig; 1424 struct rtable *orig; 1425 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1426 1427 if (rt_is_input_route(rt)) 1428 porig = &fnhe->fnhe_rth_input; 1429 else 1430 porig = &fnhe->fnhe_rth_output; 1431 orig = rcu_dereference(*porig); 1432 1433 if (fnhe->fnhe_genid != genid) { 1434 fnhe->fnhe_genid = genid; 1435 fnhe->fnhe_gw = 0; 1436 fnhe->fnhe_pmtu = 0; 1437 fnhe->fnhe_expires = 0; 1438 fnhe->fnhe_mtu_locked = false; 1439 fnhe_flush_routes(fnhe); 1440 orig = NULL; 1441 } 1442 fill_route_from_fnhe(rt, fnhe); 1443 if (!rt->rt_gw4) { 1444 rt->rt_gw4 = daddr; 1445 rt->rt_gw_family = AF_INET; 1446 } 1447 1448 if (do_cache) { 1449 dst_hold(&rt->dst); 1450 rcu_assign_pointer(*porig, rt); 1451 if (orig) { 1452 dst_dev_put(&orig->dst); 1453 dst_release(&orig->dst); 1454 } 1455 ret = true; 1456 } 1457 1458 fnhe->fnhe_stamp = jiffies; 1459 } 1460 spin_unlock_bh(&fnhe_lock); 1461 1462 return ret; 1463 } 1464 1465 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1466 { 1467 struct rtable *orig, *prev, **p; 1468 bool ret = true; 1469 1470 if (rt_is_input_route(rt)) { 1471 p = (struct rtable **)&nhc->nhc_rth_input; 1472 } else { 1473 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1474 } 1475 orig = *p; 1476 1477 /* hold dst before doing cmpxchg() to avoid race condition 1478 * on this dst 1479 */ 1480 dst_hold(&rt->dst); 1481 prev = cmpxchg(p, orig, rt); 1482 if (prev == orig) { 1483 if (orig) { 1484 rt_add_uncached_list(orig); 1485 dst_release(&orig->dst); 1486 } 1487 } else { 1488 dst_release(&rt->dst); 1489 ret = false; 1490 } 1491 1492 return ret; 1493 } 1494 1495 struct uncached_list { 1496 spinlock_t lock; 1497 struct list_head head; 1498 }; 1499 1500 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1501 1502 void rt_add_uncached_list(struct rtable *rt) 1503 { 1504 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1505 1506 rt->rt_uncached_list = ul; 1507 1508 spin_lock_bh(&ul->lock); 1509 list_add_tail(&rt->rt_uncached, &ul->head); 1510 spin_unlock_bh(&ul->lock); 1511 } 1512 1513 void rt_del_uncached_list(struct rtable *rt) 1514 { 1515 if (!list_empty(&rt->rt_uncached)) { 1516 struct uncached_list *ul = rt->rt_uncached_list; 1517 1518 spin_lock_bh(&ul->lock); 1519 list_del(&rt->rt_uncached); 1520 spin_unlock_bh(&ul->lock); 1521 } 1522 } 1523 1524 static void ipv4_dst_destroy(struct dst_entry *dst) 1525 { 1526 struct rtable *rt = (struct rtable *)dst; 1527 1528 ip_dst_metrics_put(dst); 1529 rt_del_uncached_list(rt); 1530 } 1531 1532 void rt_flush_dev(struct net_device *dev) 1533 { 1534 struct rtable *rt; 1535 int cpu; 1536 1537 for_each_possible_cpu(cpu) { 1538 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1539 1540 spin_lock_bh(&ul->lock); 1541 list_for_each_entry(rt, &ul->head, rt_uncached) { 1542 if (rt->dst.dev != dev) 1543 continue; 1544 rt->dst.dev = blackhole_netdev; 1545 dev_hold(rt->dst.dev); 1546 dev_put(dev); 1547 } 1548 spin_unlock_bh(&ul->lock); 1549 } 1550 } 1551 1552 static bool rt_cache_valid(const struct rtable *rt) 1553 { 1554 return rt && 1555 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1556 !rt_is_expired(rt); 1557 } 1558 1559 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1560 const struct fib_result *res, 1561 struct fib_nh_exception *fnhe, 1562 struct fib_info *fi, u16 type, u32 itag, 1563 const bool do_cache) 1564 { 1565 bool cached = false; 1566 1567 if (fi) { 1568 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1569 1570 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1571 rt->rt_uses_gateway = 1; 1572 rt->rt_gw_family = nhc->nhc_gw_family; 1573 /* only INET and INET6 are supported */ 1574 if (likely(nhc->nhc_gw_family == AF_INET)) 1575 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1576 else 1577 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1578 } 1579 1580 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1581 1582 #ifdef CONFIG_IP_ROUTE_CLASSID 1583 if (nhc->nhc_family == AF_INET) { 1584 struct fib_nh *nh; 1585 1586 nh = container_of(nhc, struct fib_nh, nh_common); 1587 rt->dst.tclassid = nh->nh_tclassid; 1588 } 1589 #endif 1590 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1591 if (unlikely(fnhe)) 1592 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1593 else if (do_cache) 1594 cached = rt_cache_route(nhc, rt); 1595 if (unlikely(!cached)) { 1596 /* Routes we intend to cache in nexthop exception or 1597 * FIB nexthop have the DST_NOCACHE bit clear. 1598 * However, if we are unsuccessful at storing this 1599 * route into the cache we really need to set it. 1600 */ 1601 if (!rt->rt_gw4) { 1602 rt->rt_gw_family = AF_INET; 1603 rt->rt_gw4 = daddr; 1604 } 1605 rt_add_uncached_list(rt); 1606 } 1607 } else 1608 rt_add_uncached_list(rt); 1609 1610 #ifdef CONFIG_IP_ROUTE_CLASSID 1611 #ifdef CONFIG_IP_MULTIPLE_TABLES 1612 set_class_tag(rt, res->tclassid); 1613 #endif 1614 set_class_tag(rt, itag); 1615 #endif 1616 } 1617 1618 struct rtable *rt_dst_alloc(struct net_device *dev, 1619 unsigned int flags, u16 type, 1620 bool nopolicy, bool noxfrm) 1621 { 1622 struct rtable *rt; 1623 1624 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1625 (nopolicy ? DST_NOPOLICY : 0) | 1626 (noxfrm ? DST_NOXFRM : 0)); 1627 1628 if (rt) { 1629 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1630 rt->rt_flags = flags; 1631 rt->rt_type = type; 1632 rt->rt_is_input = 0; 1633 rt->rt_iif = 0; 1634 rt->rt_pmtu = 0; 1635 rt->rt_mtu_locked = 0; 1636 rt->rt_uses_gateway = 0; 1637 rt->rt_gw_family = 0; 1638 rt->rt_gw4 = 0; 1639 INIT_LIST_HEAD(&rt->rt_uncached); 1640 1641 rt->dst.output = ip_output; 1642 if (flags & RTCF_LOCAL) 1643 rt->dst.input = ip_local_deliver; 1644 } 1645 1646 return rt; 1647 } 1648 EXPORT_SYMBOL(rt_dst_alloc); 1649 1650 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1651 { 1652 struct rtable *new_rt; 1653 1654 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1655 rt->dst.flags); 1656 1657 if (new_rt) { 1658 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1659 new_rt->rt_flags = rt->rt_flags; 1660 new_rt->rt_type = rt->rt_type; 1661 new_rt->rt_is_input = rt->rt_is_input; 1662 new_rt->rt_iif = rt->rt_iif; 1663 new_rt->rt_pmtu = rt->rt_pmtu; 1664 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1665 new_rt->rt_gw_family = rt->rt_gw_family; 1666 if (rt->rt_gw_family == AF_INET) 1667 new_rt->rt_gw4 = rt->rt_gw4; 1668 else if (rt->rt_gw_family == AF_INET6) 1669 new_rt->rt_gw6 = rt->rt_gw6; 1670 INIT_LIST_HEAD(&new_rt->rt_uncached); 1671 1672 new_rt->dst.input = rt->dst.input; 1673 new_rt->dst.output = rt->dst.output; 1674 new_rt->dst.error = rt->dst.error; 1675 new_rt->dst.lastuse = jiffies; 1676 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1677 } 1678 return new_rt; 1679 } 1680 EXPORT_SYMBOL(rt_dst_clone); 1681 1682 /* called in rcu_read_lock() section */ 1683 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1684 u8 tos, struct net_device *dev, 1685 struct in_device *in_dev, u32 *itag) 1686 { 1687 int err; 1688 1689 /* Primary sanity checks. */ 1690 if (!in_dev) 1691 return -EINVAL; 1692 1693 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1694 skb->protocol != htons(ETH_P_IP)) 1695 return -EINVAL; 1696 1697 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1698 return -EINVAL; 1699 1700 if (ipv4_is_zeronet(saddr)) { 1701 if (!ipv4_is_local_multicast(daddr) && 1702 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1703 return -EINVAL; 1704 } else { 1705 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1706 in_dev, itag); 1707 if (err < 0) 1708 return err; 1709 } 1710 return 0; 1711 } 1712 1713 /* called in rcu_read_lock() section */ 1714 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1715 u8 tos, struct net_device *dev, int our) 1716 { 1717 struct in_device *in_dev = __in_dev_get_rcu(dev); 1718 unsigned int flags = RTCF_MULTICAST; 1719 struct rtable *rth; 1720 u32 itag = 0; 1721 int err; 1722 1723 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1724 if (err) 1725 return err; 1726 1727 if (our) 1728 flags |= RTCF_LOCAL; 1729 1730 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1731 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 1732 if (!rth) 1733 return -ENOBUFS; 1734 1735 #ifdef CONFIG_IP_ROUTE_CLASSID 1736 rth->dst.tclassid = itag; 1737 #endif 1738 rth->dst.output = ip_rt_bug; 1739 rth->rt_is_input= 1; 1740 1741 #ifdef CONFIG_IP_MROUTE 1742 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1743 rth->dst.input = ip_mr_input; 1744 #endif 1745 RT_CACHE_STAT_INC(in_slow_mc); 1746 1747 skb_dst_set(skb, &rth->dst); 1748 return 0; 1749 } 1750 1751 1752 static void ip_handle_martian_source(struct net_device *dev, 1753 struct in_device *in_dev, 1754 struct sk_buff *skb, 1755 __be32 daddr, 1756 __be32 saddr) 1757 { 1758 RT_CACHE_STAT_INC(in_martian_src); 1759 #ifdef CONFIG_IP_ROUTE_VERBOSE 1760 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1761 /* 1762 * RFC1812 recommendation, if source is martian, 1763 * the only hint is MAC header. 1764 */ 1765 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1766 &daddr, &saddr, dev->name); 1767 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1768 print_hex_dump(KERN_WARNING, "ll header: ", 1769 DUMP_PREFIX_OFFSET, 16, 1, 1770 skb_mac_header(skb), 1771 dev->hard_header_len, false); 1772 } 1773 } 1774 #endif 1775 } 1776 1777 /* called in rcu_read_lock() section */ 1778 static int __mkroute_input(struct sk_buff *skb, 1779 const struct fib_result *res, 1780 struct in_device *in_dev, 1781 __be32 daddr, __be32 saddr, u32 tos) 1782 { 1783 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1784 struct net_device *dev = nhc->nhc_dev; 1785 struct fib_nh_exception *fnhe; 1786 struct rtable *rth; 1787 int err; 1788 struct in_device *out_dev; 1789 bool do_cache; 1790 u32 itag = 0; 1791 1792 /* get a working reference to the output device */ 1793 out_dev = __in_dev_get_rcu(dev); 1794 if (!out_dev) { 1795 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1796 return -EINVAL; 1797 } 1798 1799 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1800 in_dev->dev, in_dev, &itag); 1801 if (err < 0) { 1802 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1803 saddr); 1804 1805 goto cleanup; 1806 } 1807 1808 do_cache = res->fi && !itag; 1809 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1810 skb->protocol == htons(ETH_P_IP)) { 1811 __be32 gw; 1812 1813 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1814 if (IN_DEV_SHARED_MEDIA(out_dev) || 1815 inet_addr_onlink(out_dev, saddr, gw)) 1816 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1817 } 1818 1819 if (skb->protocol != htons(ETH_P_IP)) { 1820 /* Not IP (i.e. ARP). Do not create route, if it is 1821 * invalid for proxy arp. DNAT routes are always valid. 1822 * 1823 * Proxy arp feature have been extended to allow, ARP 1824 * replies back to the same interface, to support 1825 * Private VLAN switch technologies. See arp.c. 1826 */ 1827 if (out_dev == in_dev && 1828 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1829 err = -EINVAL; 1830 goto cleanup; 1831 } 1832 } 1833 1834 fnhe = find_exception(nhc, daddr); 1835 if (do_cache) { 1836 if (fnhe) 1837 rth = rcu_dereference(fnhe->fnhe_rth_input); 1838 else 1839 rth = rcu_dereference(nhc->nhc_rth_input); 1840 if (rt_cache_valid(rth)) { 1841 skb_dst_set_noref(skb, &rth->dst); 1842 goto out; 1843 } 1844 } 1845 1846 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1847 IN_DEV_ORCONF(in_dev, NOPOLICY), 1848 IN_DEV_ORCONF(out_dev, NOXFRM)); 1849 if (!rth) { 1850 err = -ENOBUFS; 1851 goto cleanup; 1852 } 1853 1854 rth->rt_is_input = 1; 1855 RT_CACHE_STAT_INC(in_slow_tot); 1856 1857 rth->dst.input = ip_forward; 1858 1859 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1860 do_cache); 1861 lwtunnel_set_redirect(&rth->dst); 1862 skb_dst_set(skb, &rth->dst); 1863 out: 1864 err = 0; 1865 cleanup: 1866 return err; 1867 } 1868 1869 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1870 /* To make ICMP packets follow the right flow, the multipath hash is 1871 * calculated from the inner IP addresses. 1872 */ 1873 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1874 struct flow_keys *hash_keys) 1875 { 1876 const struct iphdr *outer_iph = ip_hdr(skb); 1877 const struct iphdr *key_iph = outer_iph; 1878 const struct iphdr *inner_iph; 1879 const struct icmphdr *icmph; 1880 struct iphdr _inner_iph; 1881 struct icmphdr _icmph; 1882 1883 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1884 goto out; 1885 1886 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1887 goto out; 1888 1889 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1890 &_icmph); 1891 if (!icmph) 1892 goto out; 1893 1894 if (!icmp_is_err(icmph->type)) 1895 goto out; 1896 1897 inner_iph = skb_header_pointer(skb, 1898 outer_iph->ihl * 4 + sizeof(_icmph), 1899 sizeof(_inner_iph), &_inner_iph); 1900 if (!inner_iph) 1901 goto out; 1902 1903 key_iph = inner_iph; 1904 out: 1905 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1906 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1907 } 1908 1909 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1910 const struct sk_buff *skb, 1911 bool *p_has_inner) 1912 { 1913 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1914 struct flow_keys keys, hash_keys; 1915 1916 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1917 return 0; 1918 1919 memset(&hash_keys, 0, sizeof(hash_keys)); 1920 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1921 1922 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1923 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1924 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1925 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1926 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1927 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1928 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1929 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1930 hash_keys.ports.src = keys.ports.src; 1931 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1932 hash_keys.ports.dst = keys.ports.dst; 1933 1934 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1935 return flow_hash_from_keys(&hash_keys); 1936 } 1937 1938 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1939 const struct sk_buff *skb, 1940 bool has_inner) 1941 { 1942 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 1943 struct flow_keys keys, hash_keys; 1944 1945 /* We assume the packet carries an encapsulation, but if none was 1946 * encountered during dissection of the outer flow, then there is no 1947 * point in calling the flow dissector again. 1948 */ 1949 if (!has_inner) 1950 return 0; 1951 1952 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1953 return 0; 1954 1955 memset(&hash_keys, 0, sizeof(hash_keys)); 1956 skb_flow_dissect_flow_keys(skb, &keys, 0); 1957 1958 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1959 return 0; 1960 1961 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1962 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1963 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1964 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1965 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1966 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1967 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1968 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1969 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1970 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1971 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1972 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1973 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1974 hash_keys.tags.flow_label = keys.tags.flow_label; 1975 } 1976 1977 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1978 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1979 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1980 hash_keys.ports.src = keys.ports.src; 1981 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1982 hash_keys.ports.dst = keys.ports.dst; 1983 1984 return flow_hash_from_keys(&hash_keys); 1985 } 1986 1987 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1988 const struct sk_buff *skb) 1989 { 1990 u32 mhash, mhash_inner; 1991 bool has_inner = true; 1992 1993 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 1994 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 1995 1996 return jhash_2words(mhash, mhash_inner, 0); 1997 } 1998 1999 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2000 const struct flowi4 *fl4) 2001 { 2002 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; 2003 struct flow_keys hash_keys; 2004 2005 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2006 return 0; 2007 2008 memset(&hash_keys, 0, sizeof(hash_keys)); 2009 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2010 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2011 hash_keys.addrs.v4addrs.src = fl4->saddr; 2012 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2013 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2014 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2015 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2016 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2017 hash_keys.ports.src = fl4->fl4_sport; 2018 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2019 hash_keys.ports.dst = fl4->fl4_dport; 2020 2021 return flow_hash_from_keys(&hash_keys); 2022 } 2023 2024 /* if skb is set it will be used and fl4 can be NULL */ 2025 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2026 const struct sk_buff *skb, struct flow_keys *flkeys) 2027 { 2028 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2029 struct flow_keys hash_keys; 2030 u32 mhash = 0; 2031 2032 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 2033 case 0: 2034 memset(&hash_keys, 0, sizeof(hash_keys)); 2035 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2036 if (skb) { 2037 ip_multipath_l3_keys(skb, &hash_keys); 2038 } else { 2039 hash_keys.addrs.v4addrs.src = fl4->saddr; 2040 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2041 } 2042 mhash = flow_hash_from_keys(&hash_keys); 2043 break; 2044 case 1: 2045 /* skb is currently provided only when forwarding */ 2046 if (skb) { 2047 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2048 struct flow_keys keys; 2049 2050 /* short-circuit if we already have L4 hash present */ 2051 if (skb->l4_hash) 2052 return skb_get_hash_raw(skb) >> 1; 2053 2054 memset(&hash_keys, 0, sizeof(hash_keys)); 2055 2056 if (!flkeys) { 2057 skb_flow_dissect_flow_keys(skb, &keys, flag); 2058 flkeys = &keys; 2059 } 2060 2061 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2062 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2063 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2064 hash_keys.ports.src = flkeys->ports.src; 2065 hash_keys.ports.dst = flkeys->ports.dst; 2066 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2067 } else { 2068 memset(&hash_keys, 0, sizeof(hash_keys)); 2069 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2070 hash_keys.addrs.v4addrs.src = fl4->saddr; 2071 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2072 hash_keys.ports.src = fl4->fl4_sport; 2073 hash_keys.ports.dst = fl4->fl4_dport; 2074 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2075 } 2076 mhash = flow_hash_from_keys(&hash_keys); 2077 break; 2078 case 2: 2079 memset(&hash_keys, 0, sizeof(hash_keys)); 2080 /* skb is currently provided only when forwarding */ 2081 if (skb) { 2082 struct flow_keys keys; 2083 2084 skb_flow_dissect_flow_keys(skb, &keys, 0); 2085 /* Inner can be v4 or v6 */ 2086 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2087 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2088 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2089 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2090 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2091 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2092 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2093 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2094 hash_keys.tags.flow_label = keys.tags.flow_label; 2095 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2096 } else { 2097 /* Same as case 0 */ 2098 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2099 ip_multipath_l3_keys(skb, &hash_keys); 2100 } 2101 } else { 2102 /* Same as case 0 */ 2103 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2104 hash_keys.addrs.v4addrs.src = fl4->saddr; 2105 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2106 } 2107 mhash = flow_hash_from_keys(&hash_keys); 2108 break; 2109 case 3: 2110 if (skb) 2111 mhash = fib_multipath_custom_hash_skb(net, skb); 2112 else 2113 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2114 break; 2115 } 2116 2117 if (multipath_hash) 2118 mhash = jhash_2words(mhash, multipath_hash, 0); 2119 2120 return mhash >> 1; 2121 } 2122 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2123 2124 static int ip_mkroute_input(struct sk_buff *skb, 2125 struct fib_result *res, 2126 struct in_device *in_dev, 2127 __be32 daddr, __be32 saddr, u32 tos, 2128 struct flow_keys *hkeys) 2129 { 2130 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2131 if (res->fi && fib_info_num_path(res->fi) > 1) { 2132 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2133 2134 fib_select_multipath(res, h); 2135 } 2136 #endif 2137 2138 /* create a routing cache entry */ 2139 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 2140 } 2141 2142 /* Implements all the saddr-related checks as ip_route_input_slow(), 2143 * assuming daddr is valid and the destination is not a local broadcast one. 2144 * Uses the provided hint instead of performing a route lookup. 2145 */ 2146 int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2147 u8 tos, struct net_device *dev, 2148 const struct sk_buff *hint) 2149 { 2150 struct in_device *in_dev = __in_dev_get_rcu(dev); 2151 struct rtable *rt = skb_rtable(hint); 2152 struct net *net = dev_net(dev); 2153 int err = -EINVAL; 2154 u32 tag = 0; 2155 2156 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2157 goto martian_source; 2158 2159 if (ipv4_is_zeronet(saddr)) 2160 goto martian_source; 2161 2162 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2163 goto martian_source; 2164 2165 if (rt->rt_type != RTN_LOCAL) 2166 goto skip_validate_source; 2167 2168 tos &= IPTOS_RT_MASK; 2169 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); 2170 if (err < 0) 2171 goto martian_source; 2172 2173 skip_validate_source: 2174 skb_dst_copy(skb, hint); 2175 return 0; 2176 2177 martian_source: 2178 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2179 return err; 2180 } 2181 2182 /* 2183 * NOTE. We drop all the packets that has local source 2184 * addresses, because every properly looped back packet 2185 * must have correct destination already attached by output routine. 2186 * Changes in the enforced policies must be applied also to 2187 * ip_route_use_hint(). 2188 * 2189 * Such approach solves two big problems: 2190 * 1. Not simplex devices are handled properly. 2191 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2192 * called with rcu_read_lock() 2193 */ 2194 2195 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2196 u8 tos, struct net_device *dev, 2197 struct fib_result *res) 2198 { 2199 struct in_device *in_dev = __in_dev_get_rcu(dev); 2200 struct flow_keys *flkeys = NULL, _flkeys; 2201 struct net *net = dev_net(dev); 2202 struct ip_tunnel_info *tun_info; 2203 int err = -EINVAL; 2204 unsigned int flags = 0; 2205 u32 itag = 0; 2206 struct rtable *rth; 2207 struct flowi4 fl4; 2208 bool do_cache = true; 2209 2210 /* IP on this device is disabled. */ 2211 2212 if (!in_dev) 2213 goto out; 2214 2215 /* Check for the most weird martians, which can be not detected 2216 * by fib_lookup. 2217 */ 2218 2219 tun_info = skb_tunnel_info(skb); 2220 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2221 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2222 else 2223 fl4.flowi4_tun_key.tun_id = 0; 2224 skb_dst_drop(skb); 2225 2226 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2227 goto martian_source; 2228 2229 res->fi = NULL; 2230 res->table = NULL; 2231 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2232 goto brd_input; 2233 2234 /* Accept zero addresses only to limited broadcast; 2235 * I even do not know to fix it or not. Waiting for complains :-) 2236 */ 2237 if (ipv4_is_zeronet(saddr)) 2238 goto martian_source; 2239 2240 if (ipv4_is_zeronet(daddr)) 2241 goto martian_destination; 2242 2243 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2244 * and call it once if daddr or/and saddr are loopback addresses 2245 */ 2246 if (ipv4_is_loopback(daddr)) { 2247 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2248 goto martian_destination; 2249 } else if (ipv4_is_loopback(saddr)) { 2250 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2251 goto martian_source; 2252 } 2253 2254 /* 2255 * Now we are ready to route packet. 2256 */ 2257 fl4.flowi4_oif = 0; 2258 fl4.flowi4_iif = dev->ifindex; 2259 fl4.flowi4_mark = skb->mark; 2260 fl4.flowi4_tos = tos; 2261 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2262 fl4.flowi4_flags = 0; 2263 fl4.daddr = daddr; 2264 fl4.saddr = saddr; 2265 fl4.flowi4_uid = sock_net_uid(net, NULL); 2266 fl4.flowi4_multipath_hash = 0; 2267 2268 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2269 flkeys = &_flkeys; 2270 } else { 2271 fl4.flowi4_proto = 0; 2272 fl4.fl4_sport = 0; 2273 fl4.fl4_dport = 0; 2274 } 2275 2276 err = fib_lookup(net, &fl4, res, 0); 2277 if (err != 0) { 2278 if (!IN_DEV_FORWARD(in_dev)) 2279 err = -EHOSTUNREACH; 2280 goto no_route; 2281 } 2282 2283 if (res->type == RTN_BROADCAST) { 2284 if (IN_DEV_BFORWARD(in_dev)) 2285 goto make_route; 2286 /* not do cache if bc_forwarding is enabled */ 2287 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2288 do_cache = false; 2289 goto brd_input; 2290 } 2291 2292 if (res->type == RTN_LOCAL) { 2293 err = fib_validate_source(skb, saddr, daddr, tos, 2294 0, dev, in_dev, &itag); 2295 if (err < 0) 2296 goto martian_source; 2297 goto local_input; 2298 } 2299 2300 if (!IN_DEV_FORWARD(in_dev)) { 2301 err = -EHOSTUNREACH; 2302 goto no_route; 2303 } 2304 if (res->type != RTN_UNICAST) 2305 goto martian_destination; 2306 2307 make_route: 2308 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2309 out: return err; 2310 2311 brd_input: 2312 if (skb->protocol != htons(ETH_P_IP)) 2313 goto e_inval; 2314 2315 if (!ipv4_is_zeronet(saddr)) { 2316 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2317 in_dev, &itag); 2318 if (err < 0) 2319 goto martian_source; 2320 } 2321 flags |= RTCF_BROADCAST; 2322 res->type = RTN_BROADCAST; 2323 RT_CACHE_STAT_INC(in_brd); 2324 2325 local_input: 2326 do_cache &= res->fi && !itag; 2327 if (do_cache) { 2328 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2329 2330 rth = rcu_dereference(nhc->nhc_rth_input); 2331 if (rt_cache_valid(rth)) { 2332 skb_dst_set_noref(skb, &rth->dst); 2333 err = 0; 2334 goto out; 2335 } 2336 } 2337 2338 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2339 flags | RTCF_LOCAL, res->type, 2340 IN_DEV_ORCONF(in_dev, NOPOLICY), false); 2341 if (!rth) 2342 goto e_nobufs; 2343 2344 rth->dst.output= ip_rt_bug; 2345 #ifdef CONFIG_IP_ROUTE_CLASSID 2346 rth->dst.tclassid = itag; 2347 #endif 2348 rth->rt_is_input = 1; 2349 2350 RT_CACHE_STAT_INC(in_slow_tot); 2351 if (res->type == RTN_UNREACHABLE) { 2352 rth->dst.input= ip_error; 2353 rth->dst.error= -err; 2354 rth->rt_flags &= ~RTCF_LOCAL; 2355 } 2356 2357 if (do_cache) { 2358 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2359 2360 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2361 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2362 WARN_ON(rth->dst.input == lwtunnel_input); 2363 rth->dst.lwtstate->orig_input = rth->dst.input; 2364 rth->dst.input = lwtunnel_input; 2365 } 2366 2367 if (unlikely(!rt_cache_route(nhc, rth))) 2368 rt_add_uncached_list(rth); 2369 } 2370 skb_dst_set(skb, &rth->dst); 2371 err = 0; 2372 goto out; 2373 2374 no_route: 2375 RT_CACHE_STAT_INC(in_no_route); 2376 res->type = RTN_UNREACHABLE; 2377 res->fi = NULL; 2378 res->table = NULL; 2379 goto local_input; 2380 2381 /* 2382 * Do not cache martian addresses: they should be logged (RFC1812) 2383 */ 2384 martian_destination: 2385 RT_CACHE_STAT_INC(in_martian_dst); 2386 #ifdef CONFIG_IP_ROUTE_VERBOSE 2387 if (IN_DEV_LOG_MARTIANS(in_dev)) 2388 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2389 &daddr, &saddr, dev->name); 2390 #endif 2391 2392 e_inval: 2393 err = -EINVAL; 2394 goto out; 2395 2396 e_nobufs: 2397 err = -ENOBUFS; 2398 goto out; 2399 2400 martian_source: 2401 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2402 goto out; 2403 } 2404 2405 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2406 u8 tos, struct net_device *dev) 2407 { 2408 struct fib_result res; 2409 int err; 2410 2411 tos &= IPTOS_RT_MASK; 2412 rcu_read_lock(); 2413 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2414 rcu_read_unlock(); 2415 2416 return err; 2417 } 2418 EXPORT_SYMBOL(ip_route_input_noref); 2419 2420 /* called with rcu_read_lock held */ 2421 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2422 u8 tos, struct net_device *dev, struct fib_result *res) 2423 { 2424 /* Multicast recognition logic is moved from route cache to here. 2425 * The problem was that too many Ethernet cards have broken/missing 2426 * hardware multicast filters :-( As result the host on multicasting 2427 * network acquires a lot of useless route cache entries, sort of 2428 * SDR messages from all the world. Now we try to get rid of them. 2429 * Really, provided software IP multicast filter is organized 2430 * reasonably (at least, hashed), it does not result in a slowdown 2431 * comparing with route cache reject entries. 2432 * Note, that multicast routers are not affected, because 2433 * route cache entry is created eventually. 2434 */ 2435 if (ipv4_is_multicast(daddr)) { 2436 struct in_device *in_dev = __in_dev_get_rcu(dev); 2437 int our = 0; 2438 int err = -EINVAL; 2439 2440 if (!in_dev) 2441 return err; 2442 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2443 ip_hdr(skb)->protocol); 2444 2445 /* check l3 master if no match yet */ 2446 if (!our && netif_is_l3_slave(dev)) { 2447 struct in_device *l3_in_dev; 2448 2449 l3_in_dev = __in_dev_get_rcu(skb->dev); 2450 if (l3_in_dev) 2451 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2452 ip_hdr(skb)->protocol); 2453 } 2454 2455 if (our 2456 #ifdef CONFIG_IP_MROUTE 2457 || 2458 (!ipv4_is_local_multicast(daddr) && 2459 IN_DEV_MFORWARD(in_dev)) 2460 #endif 2461 ) { 2462 err = ip_route_input_mc(skb, daddr, saddr, 2463 tos, dev, our); 2464 } 2465 return err; 2466 } 2467 2468 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2469 } 2470 2471 /* called with rcu_read_lock() */ 2472 static struct rtable *__mkroute_output(const struct fib_result *res, 2473 const struct flowi4 *fl4, int orig_oif, 2474 struct net_device *dev_out, 2475 unsigned int flags) 2476 { 2477 struct fib_info *fi = res->fi; 2478 struct fib_nh_exception *fnhe; 2479 struct in_device *in_dev; 2480 u16 type = res->type; 2481 struct rtable *rth; 2482 bool do_cache; 2483 2484 in_dev = __in_dev_get_rcu(dev_out); 2485 if (!in_dev) 2486 return ERR_PTR(-EINVAL); 2487 2488 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2489 if (ipv4_is_loopback(fl4->saddr) && 2490 !(dev_out->flags & IFF_LOOPBACK) && 2491 !netif_is_l3_master(dev_out)) 2492 return ERR_PTR(-EINVAL); 2493 2494 if (ipv4_is_lbcast(fl4->daddr)) 2495 type = RTN_BROADCAST; 2496 else if (ipv4_is_multicast(fl4->daddr)) 2497 type = RTN_MULTICAST; 2498 else if (ipv4_is_zeronet(fl4->daddr)) 2499 return ERR_PTR(-EINVAL); 2500 2501 if (dev_out->flags & IFF_LOOPBACK) 2502 flags |= RTCF_LOCAL; 2503 2504 do_cache = true; 2505 if (type == RTN_BROADCAST) { 2506 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2507 fi = NULL; 2508 } else if (type == RTN_MULTICAST) { 2509 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2510 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2511 fl4->flowi4_proto)) 2512 flags &= ~RTCF_LOCAL; 2513 else 2514 do_cache = false; 2515 /* If multicast route do not exist use 2516 * default one, but do not gateway in this case. 2517 * Yes, it is hack. 2518 */ 2519 if (fi && res->prefixlen < 4) 2520 fi = NULL; 2521 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2522 (orig_oif != dev_out->ifindex)) { 2523 /* For local routes that require a particular output interface 2524 * we do not want to cache the result. Caching the result 2525 * causes incorrect behaviour when there are multiple source 2526 * addresses on the interface, the end result being that if the 2527 * intended recipient is waiting on that interface for the 2528 * packet he won't receive it because it will be delivered on 2529 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2530 * be set to the loopback interface as well. 2531 */ 2532 do_cache = false; 2533 } 2534 2535 fnhe = NULL; 2536 do_cache &= fi != NULL; 2537 if (fi) { 2538 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2539 struct rtable __rcu **prth; 2540 2541 fnhe = find_exception(nhc, fl4->daddr); 2542 if (!do_cache) 2543 goto add; 2544 if (fnhe) { 2545 prth = &fnhe->fnhe_rth_output; 2546 } else { 2547 if (unlikely(fl4->flowi4_flags & 2548 FLOWI_FLAG_KNOWN_NH && 2549 !(nhc->nhc_gw_family && 2550 nhc->nhc_scope == RT_SCOPE_LINK))) { 2551 do_cache = false; 2552 goto add; 2553 } 2554 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2555 } 2556 rth = rcu_dereference(*prth); 2557 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2558 return rth; 2559 } 2560 2561 add: 2562 rth = rt_dst_alloc(dev_out, flags, type, 2563 IN_DEV_ORCONF(in_dev, NOPOLICY), 2564 IN_DEV_ORCONF(in_dev, NOXFRM)); 2565 if (!rth) 2566 return ERR_PTR(-ENOBUFS); 2567 2568 rth->rt_iif = orig_oif; 2569 2570 RT_CACHE_STAT_INC(out_slow_tot); 2571 2572 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2573 if (flags & RTCF_LOCAL && 2574 !(dev_out->flags & IFF_LOOPBACK)) { 2575 rth->dst.output = ip_mc_output; 2576 RT_CACHE_STAT_INC(out_slow_mc); 2577 } 2578 #ifdef CONFIG_IP_MROUTE 2579 if (type == RTN_MULTICAST) { 2580 if (IN_DEV_MFORWARD(in_dev) && 2581 !ipv4_is_local_multicast(fl4->daddr)) { 2582 rth->dst.input = ip_mr_input; 2583 rth->dst.output = ip_mc_output; 2584 } 2585 } 2586 #endif 2587 } 2588 2589 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2590 lwtunnel_set_redirect(&rth->dst); 2591 2592 return rth; 2593 } 2594 2595 /* 2596 * Major route resolver routine. 2597 */ 2598 2599 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2600 const struct sk_buff *skb) 2601 { 2602 __u8 tos = RT_FL_TOS(fl4); 2603 struct fib_result res = { 2604 .type = RTN_UNSPEC, 2605 .fi = NULL, 2606 .table = NULL, 2607 .tclassid = 0, 2608 }; 2609 struct rtable *rth; 2610 2611 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2612 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2613 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2614 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2615 2616 rcu_read_lock(); 2617 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2618 rcu_read_unlock(); 2619 2620 return rth; 2621 } 2622 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2623 2624 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2625 struct fib_result *res, 2626 const struct sk_buff *skb) 2627 { 2628 struct net_device *dev_out = NULL; 2629 int orig_oif = fl4->flowi4_oif; 2630 unsigned int flags = 0; 2631 struct rtable *rth; 2632 int err; 2633 2634 if (fl4->saddr) { 2635 if (ipv4_is_multicast(fl4->saddr) || 2636 ipv4_is_lbcast(fl4->saddr) || 2637 ipv4_is_zeronet(fl4->saddr)) { 2638 rth = ERR_PTR(-EINVAL); 2639 goto out; 2640 } 2641 2642 rth = ERR_PTR(-ENETUNREACH); 2643 2644 /* I removed check for oif == dev_out->oif here. 2645 * It was wrong for two reasons: 2646 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2647 * is assigned to multiple interfaces. 2648 * 2. Moreover, we are allowed to send packets with saddr 2649 * of another iface. --ANK 2650 */ 2651 2652 if (fl4->flowi4_oif == 0 && 2653 (ipv4_is_multicast(fl4->daddr) || 2654 ipv4_is_lbcast(fl4->daddr))) { 2655 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2656 dev_out = __ip_dev_find(net, fl4->saddr, false); 2657 if (!dev_out) 2658 goto out; 2659 2660 /* Special hack: user can direct multicasts 2661 * and limited broadcast via necessary interface 2662 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2663 * This hack is not just for fun, it allows 2664 * vic,vat and friends to work. 2665 * They bind socket to loopback, set ttl to zero 2666 * and expect that it will work. 2667 * From the viewpoint of routing cache they are broken, 2668 * because we are not allowed to build multicast path 2669 * with loopback source addr (look, routing cache 2670 * cannot know, that ttl is zero, so that packet 2671 * will not leave this host and route is valid). 2672 * Luckily, this hack is good workaround. 2673 */ 2674 2675 fl4->flowi4_oif = dev_out->ifindex; 2676 goto make_route; 2677 } 2678 2679 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2680 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2681 if (!__ip_dev_find(net, fl4->saddr, false)) 2682 goto out; 2683 } 2684 } 2685 2686 2687 if (fl4->flowi4_oif) { 2688 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2689 rth = ERR_PTR(-ENODEV); 2690 if (!dev_out) 2691 goto out; 2692 2693 /* RACE: Check return value of inet_select_addr instead. */ 2694 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2695 rth = ERR_PTR(-ENETUNREACH); 2696 goto out; 2697 } 2698 if (ipv4_is_local_multicast(fl4->daddr) || 2699 ipv4_is_lbcast(fl4->daddr) || 2700 fl4->flowi4_proto == IPPROTO_IGMP) { 2701 if (!fl4->saddr) 2702 fl4->saddr = inet_select_addr(dev_out, 0, 2703 RT_SCOPE_LINK); 2704 goto make_route; 2705 } 2706 if (!fl4->saddr) { 2707 if (ipv4_is_multicast(fl4->daddr)) 2708 fl4->saddr = inet_select_addr(dev_out, 0, 2709 fl4->flowi4_scope); 2710 else if (!fl4->daddr) 2711 fl4->saddr = inet_select_addr(dev_out, 0, 2712 RT_SCOPE_HOST); 2713 } 2714 } 2715 2716 if (!fl4->daddr) { 2717 fl4->daddr = fl4->saddr; 2718 if (!fl4->daddr) 2719 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2720 dev_out = net->loopback_dev; 2721 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2722 res->type = RTN_LOCAL; 2723 flags |= RTCF_LOCAL; 2724 goto make_route; 2725 } 2726 2727 err = fib_lookup(net, fl4, res, 0); 2728 if (err) { 2729 res->fi = NULL; 2730 res->table = NULL; 2731 if (fl4->flowi4_oif && 2732 (ipv4_is_multicast(fl4->daddr) || 2733 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2734 /* Apparently, routing tables are wrong. Assume, 2735 * that the destination is on link. 2736 * 2737 * WHY? DW. 2738 * Because we are allowed to send to iface 2739 * even if it has NO routes and NO assigned 2740 * addresses. When oif is specified, routing 2741 * tables are looked up with only one purpose: 2742 * to catch if destination is gatewayed, rather than 2743 * direct. Moreover, if MSG_DONTROUTE is set, 2744 * we send packet, ignoring both routing tables 2745 * and ifaddr state. --ANK 2746 * 2747 * 2748 * We could make it even if oif is unknown, 2749 * likely IPv6, but we do not. 2750 */ 2751 2752 if (fl4->saddr == 0) 2753 fl4->saddr = inet_select_addr(dev_out, 0, 2754 RT_SCOPE_LINK); 2755 res->type = RTN_UNICAST; 2756 goto make_route; 2757 } 2758 rth = ERR_PTR(err); 2759 goto out; 2760 } 2761 2762 if (res->type == RTN_LOCAL) { 2763 if (!fl4->saddr) { 2764 if (res->fi->fib_prefsrc) 2765 fl4->saddr = res->fi->fib_prefsrc; 2766 else 2767 fl4->saddr = fl4->daddr; 2768 } 2769 2770 /* L3 master device is the loopback for that domain */ 2771 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2772 net->loopback_dev; 2773 2774 /* make sure orig_oif points to fib result device even 2775 * though packet rx/tx happens over loopback or l3mdev 2776 */ 2777 orig_oif = FIB_RES_OIF(*res); 2778 2779 fl4->flowi4_oif = dev_out->ifindex; 2780 flags |= RTCF_LOCAL; 2781 goto make_route; 2782 } 2783 2784 fib_select_path(net, res, fl4, skb); 2785 2786 dev_out = FIB_RES_DEV(*res); 2787 2788 make_route: 2789 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2790 2791 out: 2792 return rth; 2793 } 2794 2795 static struct dst_ops ipv4_dst_blackhole_ops = { 2796 .family = AF_INET, 2797 .default_advmss = ipv4_default_advmss, 2798 .neigh_lookup = ipv4_neigh_lookup, 2799 .check = dst_blackhole_check, 2800 .cow_metrics = dst_blackhole_cow_metrics, 2801 .update_pmtu = dst_blackhole_update_pmtu, 2802 .redirect = dst_blackhole_redirect, 2803 .mtu = dst_blackhole_mtu, 2804 }; 2805 2806 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2807 { 2808 struct rtable *ort = (struct rtable *) dst_orig; 2809 struct rtable *rt; 2810 2811 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2812 if (rt) { 2813 struct dst_entry *new = &rt->dst; 2814 2815 new->__use = 1; 2816 new->input = dst_discard; 2817 new->output = dst_discard_out; 2818 2819 new->dev = net->loopback_dev; 2820 if (new->dev) 2821 dev_hold(new->dev); 2822 2823 rt->rt_is_input = ort->rt_is_input; 2824 rt->rt_iif = ort->rt_iif; 2825 rt->rt_pmtu = ort->rt_pmtu; 2826 rt->rt_mtu_locked = ort->rt_mtu_locked; 2827 2828 rt->rt_genid = rt_genid_ipv4(net); 2829 rt->rt_flags = ort->rt_flags; 2830 rt->rt_type = ort->rt_type; 2831 rt->rt_uses_gateway = ort->rt_uses_gateway; 2832 rt->rt_gw_family = ort->rt_gw_family; 2833 if (rt->rt_gw_family == AF_INET) 2834 rt->rt_gw4 = ort->rt_gw4; 2835 else if (rt->rt_gw_family == AF_INET6) 2836 rt->rt_gw6 = ort->rt_gw6; 2837 2838 INIT_LIST_HEAD(&rt->rt_uncached); 2839 } 2840 2841 dst_release(dst_orig); 2842 2843 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2844 } 2845 2846 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2847 const struct sock *sk) 2848 { 2849 struct rtable *rt = __ip_route_output_key(net, flp4); 2850 2851 if (IS_ERR(rt)) 2852 return rt; 2853 2854 if (flp4->flowi4_proto) { 2855 flp4->flowi4_oif = rt->dst.dev->ifindex; 2856 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2857 flowi4_to_flowi(flp4), 2858 sk, 0); 2859 } 2860 2861 return rt; 2862 } 2863 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2864 2865 struct rtable *ip_route_output_tunnel(struct sk_buff *skb, 2866 struct net_device *dev, 2867 struct net *net, __be32 *saddr, 2868 const struct ip_tunnel_info *info, 2869 u8 protocol, bool use_cache) 2870 { 2871 #ifdef CONFIG_DST_CACHE 2872 struct dst_cache *dst_cache; 2873 #endif 2874 struct rtable *rt = NULL; 2875 struct flowi4 fl4; 2876 __u8 tos; 2877 2878 #ifdef CONFIG_DST_CACHE 2879 dst_cache = (struct dst_cache *)&info->dst_cache; 2880 if (use_cache) { 2881 rt = dst_cache_get_ip4(dst_cache, saddr); 2882 if (rt) 2883 return rt; 2884 } 2885 #endif 2886 memset(&fl4, 0, sizeof(fl4)); 2887 fl4.flowi4_mark = skb->mark; 2888 fl4.flowi4_proto = protocol; 2889 fl4.daddr = info->key.u.ipv4.dst; 2890 fl4.saddr = info->key.u.ipv4.src; 2891 tos = info->key.tos; 2892 fl4.flowi4_tos = RT_TOS(tos); 2893 2894 rt = ip_route_output_key(net, &fl4); 2895 if (IS_ERR(rt)) { 2896 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr); 2897 return ERR_PTR(-ENETUNREACH); 2898 } 2899 if (rt->dst.dev == dev) { /* is this necessary? */ 2900 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr); 2901 ip_rt_put(rt); 2902 return ERR_PTR(-ELOOP); 2903 } 2904 #ifdef CONFIG_DST_CACHE 2905 if (use_cache) 2906 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr); 2907 #endif 2908 *saddr = fl4.saddr; 2909 return rt; 2910 } 2911 EXPORT_SYMBOL_GPL(ip_route_output_tunnel); 2912 2913 /* called with rcu_read_lock held */ 2914 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2915 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2916 struct sk_buff *skb, u32 portid, u32 seq, 2917 unsigned int flags) 2918 { 2919 struct rtmsg *r; 2920 struct nlmsghdr *nlh; 2921 unsigned long expires = 0; 2922 u32 error; 2923 u32 metrics[RTAX_MAX]; 2924 2925 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2926 if (!nlh) 2927 return -EMSGSIZE; 2928 2929 r = nlmsg_data(nlh); 2930 r->rtm_family = AF_INET; 2931 r->rtm_dst_len = 32; 2932 r->rtm_src_len = 0; 2933 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0; 2934 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2935 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2936 goto nla_put_failure; 2937 r->rtm_type = rt->rt_type; 2938 r->rtm_scope = RT_SCOPE_UNIVERSE; 2939 r->rtm_protocol = RTPROT_UNSPEC; 2940 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2941 if (rt->rt_flags & RTCF_NOTIFY) 2942 r->rtm_flags |= RTM_F_NOTIFY; 2943 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2944 r->rtm_flags |= RTCF_DOREDIRECT; 2945 2946 if (nla_put_in_addr(skb, RTA_DST, dst)) 2947 goto nla_put_failure; 2948 if (src) { 2949 r->rtm_src_len = 32; 2950 if (nla_put_in_addr(skb, RTA_SRC, src)) 2951 goto nla_put_failure; 2952 } 2953 if (rt->dst.dev && 2954 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2955 goto nla_put_failure; 2956 if (rt->dst.lwtstate && 2957 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2958 goto nla_put_failure; 2959 #ifdef CONFIG_IP_ROUTE_CLASSID 2960 if (rt->dst.tclassid && 2961 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2962 goto nla_put_failure; 2963 #endif 2964 if (fl4 && !rt_is_input_route(rt) && 2965 fl4->saddr != src) { 2966 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2967 goto nla_put_failure; 2968 } 2969 if (rt->rt_uses_gateway) { 2970 if (rt->rt_gw_family == AF_INET && 2971 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2972 goto nla_put_failure; 2973 } else if (rt->rt_gw_family == AF_INET6) { 2974 int alen = sizeof(struct in6_addr); 2975 struct nlattr *nla; 2976 struct rtvia *via; 2977 2978 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2979 if (!nla) 2980 goto nla_put_failure; 2981 2982 via = nla_data(nla); 2983 via->rtvia_family = AF_INET6; 2984 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2985 } 2986 } 2987 2988 expires = rt->dst.expires; 2989 if (expires) { 2990 unsigned long now = jiffies; 2991 2992 if (time_before(now, expires)) 2993 expires -= now; 2994 else 2995 expires = 0; 2996 } 2997 2998 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2999 if (rt->rt_pmtu && expires) 3000 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3001 if (rt->rt_mtu_locked && expires) 3002 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3003 if (rtnetlink_put_metrics(skb, metrics) < 0) 3004 goto nla_put_failure; 3005 3006 if (fl4) { 3007 if (fl4->flowi4_mark && 3008 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3009 goto nla_put_failure; 3010 3011 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3012 nla_put_u32(skb, RTA_UID, 3013 from_kuid_munged(current_user_ns(), 3014 fl4->flowi4_uid))) 3015 goto nla_put_failure; 3016 3017 if (rt_is_input_route(rt)) { 3018 #ifdef CONFIG_IP_MROUTE 3019 if (ipv4_is_multicast(dst) && 3020 !ipv4_is_local_multicast(dst) && 3021 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 3022 int err = ipmr_get_route(net, skb, 3023 fl4->saddr, fl4->daddr, 3024 r, portid); 3025 3026 if (err <= 0) { 3027 if (err == 0) 3028 return 0; 3029 goto nla_put_failure; 3030 } 3031 } else 3032 #endif 3033 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3034 goto nla_put_failure; 3035 } 3036 } 3037 3038 error = rt->dst.error; 3039 3040 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3041 goto nla_put_failure; 3042 3043 nlmsg_end(skb, nlh); 3044 return 0; 3045 3046 nla_put_failure: 3047 nlmsg_cancel(skb, nlh); 3048 return -EMSGSIZE; 3049 } 3050 3051 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3052 struct netlink_callback *cb, u32 table_id, 3053 struct fnhe_hash_bucket *bucket, int genid, 3054 int *fa_index, int fa_start, unsigned int flags) 3055 { 3056 int i; 3057 3058 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3059 struct fib_nh_exception *fnhe; 3060 3061 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3062 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3063 struct rtable *rt; 3064 int err; 3065 3066 if (*fa_index < fa_start) 3067 goto next; 3068 3069 if (fnhe->fnhe_genid != genid) 3070 goto next; 3071 3072 if (fnhe->fnhe_expires && 3073 time_after(jiffies, fnhe->fnhe_expires)) 3074 goto next; 3075 3076 rt = rcu_dereference(fnhe->fnhe_rth_input); 3077 if (!rt) 3078 rt = rcu_dereference(fnhe->fnhe_rth_output); 3079 if (!rt) 3080 goto next; 3081 3082 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3083 table_id, NULL, skb, 3084 NETLINK_CB(cb->skb).portid, 3085 cb->nlh->nlmsg_seq, flags); 3086 if (err) 3087 return err; 3088 next: 3089 (*fa_index)++; 3090 } 3091 } 3092 3093 return 0; 3094 } 3095 3096 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3097 u32 table_id, struct fib_info *fi, 3098 int *fa_index, int fa_start, unsigned int flags) 3099 { 3100 struct net *net = sock_net(cb->skb->sk); 3101 int nhsel, genid = fnhe_genid(net); 3102 3103 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3104 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3105 struct fnhe_hash_bucket *bucket; 3106 int err; 3107 3108 if (nhc->nhc_flags & RTNH_F_DEAD) 3109 continue; 3110 3111 rcu_read_lock(); 3112 bucket = rcu_dereference(nhc->nhc_exceptions); 3113 err = 0; 3114 if (bucket) 3115 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3116 genid, fa_index, fa_start, 3117 flags); 3118 rcu_read_unlock(); 3119 if (err) 3120 return err; 3121 } 3122 3123 return 0; 3124 } 3125 3126 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3127 u8 ip_proto, __be16 sport, 3128 __be16 dport) 3129 { 3130 struct sk_buff *skb; 3131 struct iphdr *iph; 3132 3133 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3134 if (!skb) 3135 return NULL; 3136 3137 /* Reserve room for dummy headers, this skb can pass 3138 * through good chunk of routing engine. 3139 */ 3140 skb_reset_mac_header(skb); 3141 skb_reset_network_header(skb); 3142 skb->protocol = htons(ETH_P_IP); 3143 iph = skb_put(skb, sizeof(struct iphdr)); 3144 iph->protocol = ip_proto; 3145 iph->saddr = src; 3146 iph->daddr = dst; 3147 iph->version = 0x4; 3148 iph->frag_off = 0; 3149 iph->ihl = 0x5; 3150 skb_set_transport_header(skb, skb->len); 3151 3152 switch (iph->protocol) { 3153 case IPPROTO_UDP: { 3154 struct udphdr *udph; 3155 3156 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3157 udph->source = sport; 3158 udph->dest = dport; 3159 udph->len = sizeof(struct udphdr); 3160 udph->check = 0; 3161 break; 3162 } 3163 case IPPROTO_TCP: { 3164 struct tcphdr *tcph; 3165 3166 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3167 tcph->source = sport; 3168 tcph->dest = dport; 3169 tcph->doff = sizeof(struct tcphdr) / 4; 3170 tcph->rst = 1; 3171 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3172 src, dst, 0); 3173 break; 3174 } 3175 case IPPROTO_ICMP: { 3176 struct icmphdr *icmph; 3177 3178 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3179 icmph->type = ICMP_ECHO; 3180 icmph->code = 0; 3181 } 3182 } 3183 3184 return skb; 3185 } 3186 3187 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3188 const struct nlmsghdr *nlh, 3189 struct nlattr **tb, 3190 struct netlink_ext_ack *extack) 3191 { 3192 struct rtmsg *rtm; 3193 int i, err; 3194 3195 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3196 NL_SET_ERR_MSG(extack, 3197 "ipv4: Invalid header for route get request"); 3198 return -EINVAL; 3199 } 3200 3201 if (!netlink_strict_get_check(skb)) 3202 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3203 rtm_ipv4_policy, extack); 3204 3205 rtm = nlmsg_data(nlh); 3206 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3207 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3208 rtm->rtm_table || rtm->rtm_protocol || 3209 rtm->rtm_scope || rtm->rtm_type) { 3210 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3211 return -EINVAL; 3212 } 3213 3214 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3215 RTM_F_LOOKUP_TABLE | 3216 RTM_F_FIB_MATCH)) { 3217 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3218 return -EINVAL; 3219 } 3220 3221 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3222 rtm_ipv4_policy, extack); 3223 if (err) 3224 return err; 3225 3226 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3227 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3228 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3229 return -EINVAL; 3230 } 3231 3232 for (i = 0; i <= RTA_MAX; i++) { 3233 if (!tb[i]) 3234 continue; 3235 3236 switch (i) { 3237 case RTA_IIF: 3238 case RTA_OIF: 3239 case RTA_SRC: 3240 case RTA_DST: 3241 case RTA_IP_PROTO: 3242 case RTA_SPORT: 3243 case RTA_DPORT: 3244 case RTA_MARK: 3245 case RTA_UID: 3246 break; 3247 default: 3248 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3249 return -EINVAL; 3250 } 3251 } 3252 3253 return 0; 3254 } 3255 3256 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3257 struct netlink_ext_ack *extack) 3258 { 3259 struct net *net = sock_net(in_skb->sk); 3260 struct nlattr *tb[RTA_MAX+1]; 3261 u32 table_id = RT_TABLE_MAIN; 3262 __be16 sport = 0, dport = 0; 3263 struct fib_result res = {}; 3264 u8 ip_proto = IPPROTO_UDP; 3265 struct rtable *rt = NULL; 3266 struct sk_buff *skb; 3267 struct rtmsg *rtm; 3268 struct flowi4 fl4 = {}; 3269 __be32 dst = 0; 3270 __be32 src = 0; 3271 kuid_t uid; 3272 u32 iif; 3273 int err; 3274 int mark; 3275 3276 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3277 if (err < 0) 3278 return err; 3279 3280 rtm = nlmsg_data(nlh); 3281 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 3282 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 3283 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3284 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3285 if (tb[RTA_UID]) 3286 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3287 else 3288 uid = (iif ? INVALID_UID : current_uid()); 3289 3290 if (tb[RTA_IP_PROTO]) { 3291 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3292 &ip_proto, AF_INET, extack); 3293 if (err) 3294 return err; 3295 } 3296 3297 if (tb[RTA_SPORT]) 3298 sport = nla_get_be16(tb[RTA_SPORT]); 3299 3300 if (tb[RTA_DPORT]) 3301 dport = nla_get_be16(tb[RTA_DPORT]); 3302 3303 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3304 if (!skb) 3305 return -ENOBUFS; 3306 3307 fl4.daddr = dst; 3308 fl4.saddr = src; 3309 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK; 3310 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 3311 fl4.flowi4_mark = mark; 3312 fl4.flowi4_uid = uid; 3313 if (sport) 3314 fl4.fl4_sport = sport; 3315 if (dport) 3316 fl4.fl4_dport = dport; 3317 fl4.flowi4_proto = ip_proto; 3318 3319 rcu_read_lock(); 3320 3321 if (iif) { 3322 struct net_device *dev; 3323 3324 dev = dev_get_by_index_rcu(net, iif); 3325 if (!dev) { 3326 err = -ENODEV; 3327 goto errout_rcu; 3328 } 3329 3330 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3331 skb->dev = dev; 3332 skb->mark = mark; 3333 err = ip_route_input_rcu(skb, dst, src, 3334 rtm->rtm_tos & IPTOS_RT_MASK, dev, 3335 &res); 3336 3337 rt = skb_rtable(skb); 3338 if (err == 0 && rt->dst.error) 3339 err = -rt->dst.error; 3340 } else { 3341 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3342 skb->dev = net->loopback_dev; 3343 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3344 err = 0; 3345 if (IS_ERR(rt)) 3346 err = PTR_ERR(rt); 3347 else 3348 skb_dst_set(skb, &rt->dst); 3349 } 3350 3351 if (err) 3352 goto errout_rcu; 3353 3354 if (rtm->rtm_flags & RTM_F_NOTIFY) 3355 rt->rt_flags |= RTCF_NOTIFY; 3356 3357 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3358 table_id = res.table ? res.table->tb_id : 0; 3359 3360 /* reset skb for netlink reply msg */ 3361 skb_trim(skb, 0); 3362 skb_reset_network_header(skb); 3363 skb_reset_transport_header(skb); 3364 skb_reset_mac_header(skb); 3365 3366 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3367 struct fib_rt_info fri; 3368 3369 if (!res.fi) { 3370 err = fib_props[res.type].error; 3371 if (!err) 3372 err = -EHOSTUNREACH; 3373 goto errout_rcu; 3374 } 3375 fri.fi = res.fi; 3376 fri.tb_id = table_id; 3377 fri.dst = res.prefix; 3378 fri.dst_len = res.prefixlen; 3379 fri.tos = fl4.flowi4_tos; 3380 fri.type = rt->rt_type; 3381 fri.offload = 0; 3382 fri.trap = 0; 3383 fri.offload_failed = 0; 3384 if (res.fa_head) { 3385 struct fib_alias *fa; 3386 3387 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3388 u8 slen = 32 - fri.dst_len; 3389 3390 if (fa->fa_slen == slen && 3391 fa->tb_id == fri.tb_id && 3392 fa->fa_tos == fri.tos && 3393 fa->fa_info == res.fi && 3394 fa->fa_type == fri.type) { 3395 fri.offload = fa->offload; 3396 fri.trap = fa->trap; 3397 break; 3398 } 3399 } 3400 } 3401 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3402 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3403 } else { 3404 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3405 NETLINK_CB(in_skb).portid, 3406 nlh->nlmsg_seq, 0); 3407 } 3408 if (err < 0) 3409 goto errout_rcu; 3410 3411 rcu_read_unlock(); 3412 3413 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3414 3415 errout_free: 3416 return err; 3417 errout_rcu: 3418 rcu_read_unlock(); 3419 kfree_skb(skb); 3420 goto errout_free; 3421 } 3422 3423 void ip_rt_multicast_event(struct in_device *in_dev) 3424 { 3425 rt_cache_flush(dev_net(in_dev->dev)); 3426 } 3427 3428 #ifdef CONFIG_SYSCTL 3429 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3430 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3431 static int ip_rt_gc_elasticity __read_mostly = 8; 3432 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3433 3434 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3435 void *buffer, size_t *lenp, loff_t *ppos) 3436 { 3437 struct net *net = (struct net *)__ctl->extra1; 3438 3439 if (write) { 3440 rt_cache_flush(net); 3441 fnhe_genid_bump(net); 3442 return 0; 3443 } 3444 3445 return -EINVAL; 3446 } 3447 3448 static struct ctl_table ipv4_route_table[] = { 3449 { 3450 .procname = "gc_thresh", 3451 .data = &ipv4_dst_ops.gc_thresh, 3452 .maxlen = sizeof(int), 3453 .mode = 0644, 3454 .proc_handler = proc_dointvec, 3455 }, 3456 { 3457 .procname = "max_size", 3458 .data = &ip_rt_max_size, 3459 .maxlen = sizeof(int), 3460 .mode = 0644, 3461 .proc_handler = proc_dointvec, 3462 }, 3463 { 3464 /* Deprecated. Use gc_min_interval_ms */ 3465 3466 .procname = "gc_min_interval", 3467 .data = &ip_rt_gc_min_interval, 3468 .maxlen = sizeof(int), 3469 .mode = 0644, 3470 .proc_handler = proc_dointvec_jiffies, 3471 }, 3472 { 3473 .procname = "gc_min_interval_ms", 3474 .data = &ip_rt_gc_min_interval, 3475 .maxlen = sizeof(int), 3476 .mode = 0644, 3477 .proc_handler = proc_dointvec_ms_jiffies, 3478 }, 3479 { 3480 .procname = "gc_timeout", 3481 .data = &ip_rt_gc_timeout, 3482 .maxlen = sizeof(int), 3483 .mode = 0644, 3484 .proc_handler = proc_dointvec_jiffies, 3485 }, 3486 { 3487 .procname = "gc_interval", 3488 .data = &ip_rt_gc_interval, 3489 .maxlen = sizeof(int), 3490 .mode = 0644, 3491 .proc_handler = proc_dointvec_jiffies, 3492 }, 3493 { 3494 .procname = "redirect_load", 3495 .data = &ip_rt_redirect_load, 3496 .maxlen = sizeof(int), 3497 .mode = 0644, 3498 .proc_handler = proc_dointvec, 3499 }, 3500 { 3501 .procname = "redirect_number", 3502 .data = &ip_rt_redirect_number, 3503 .maxlen = sizeof(int), 3504 .mode = 0644, 3505 .proc_handler = proc_dointvec, 3506 }, 3507 { 3508 .procname = "redirect_silence", 3509 .data = &ip_rt_redirect_silence, 3510 .maxlen = sizeof(int), 3511 .mode = 0644, 3512 .proc_handler = proc_dointvec, 3513 }, 3514 { 3515 .procname = "error_cost", 3516 .data = &ip_rt_error_cost, 3517 .maxlen = sizeof(int), 3518 .mode = 0644, 3519 .proc_handler = proc_dointvec, 3520 }, 3521 { 3522 .procname = "error_burst", 3523 .data = &ip_rt_error_burst, 3524 .maxlen = sizeof(int), 3525 .mode = 0644, 3526 .proc_handler = proc_dointvec, 3527 }, 3528 { 3529 .procname = "gc_elasticity", 3530 .data = &ip_rt_gc_elasticity, 3531 .maxlen = sizeof(int), 3532 .mode = 0644, 3533 .proc_handler = proc_dointvec, 3534 }, 3535 { 3536 .procname = "mtu_expires", 3537 .data = &ip_rt_mtu_expires, 3538 .maxlen = sizeof(int), 3539 .mode = 0644, 3540 .proc_handler = proc_dointvec_jiffies, 3541 }, 3542 { 3543 .procname = "min_pmtu", 3544 .data = &ip_rt_min_pmtu, 3545 .maxlen = sizeof(int), 3546 .mode = 0644, 3547 .proc_handler = proc_dointvec_minmax, 3548 .extra1 = &ip_min_valid_pmtu, 3549 }, 3550 { 3551 .procname = "min_adv_mss", 3552 .data = &ip_rt_min_advmss, 3553 .maxlen = sizeof(int), 3554 .mode = 0644, 3555 .proc_handler = proc_dointvec, 3556 }, 3557 { } 3558 }; 3559 3560 static const char ipv4_route_flush_procname[] = "flush"; 3561 3562 static struct ctl_table ipv4_route_flush_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 }; 3571 3572 static __net_init int sysctl_route_net_init(struct net *net) 3573 { 3574 struct ctl_table *tbl; 3575 3576 tbl = ipv4_route_flush_table; 3577 if (!net_eq(net, &init_net)) { 3578 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3579 if (!tbl) 3580 goto err_dup; 3581 3582 /* Don't export non-whitelisted sysctls to unprivileged users */ 3583 if (net->user_ns != &init_user_ns) { 3584 if (tbl[0].procname != ipv4_route_flush_procname) 3585 tbl[0].procname = NULL; 3586 } 3587 } 3588 tbl[0].extra1 = net; 3589 3590 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3591 if (!net->ipv4.route_hdr) 3592 goto err_reg; 3593 return 0; 3594 3595 err_reg: 3596 if (tbl != ipv4_route_flush_table) 3597 kfree(tbl); 3598 err_dup: 3599 return -ENOMEM; 3600 } 3601 3602 static __net_exit void sysctl_route_net_exit(struct net *net) 3603 { 3604 struct ctl_table *tbl; 3605 3606 tbl = net->ipv4.route_hdr->ctl_table_arg; 3607 unregister_net_sysctl_table(net->ipv4.route_hdr); 3608 BUG_ON(tbl == ipv4_route_flush_table); 3609 kfree(tbl); 3610 } 3611 3612 static __net_initdata struct pernet_operations sysctl_route_ops = { 3613 .init = sysctl_route_net_init, 3614 .exit = sysctl_route_net_exit, 3615 }; 3616 #endif 3617 3618 static __net_init int rt_genid_init(struct net *net) 3619 { 3620 atomic_set(&net->ipv4.rt_genid, 0); 3621 atomic_set(&net->fnhe_genid, 0); 3622 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3623 return 0; 3624 } 3625 3626 static __net_initdata struct pernet_operations rt_genid_ops = { 3627 .init = rt_genid_init, 3628 }; 3629 3630 static int __net_init ipv4_inetpeer_init(struct net *net) 3631 { 3632 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3633 3634 if (!bp) 3635 return -ENOMEM; 3636 inet_peer_base_init(bp); 3637 net->ipv4.peers = bp; 3638 return 0; 3639 } 3640 3641 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3642 { 3643 struct inet_peer_base *bp = net->ipv4.peers; 3644 3645 net->ipv4.peers = NULL; 3646 inetpeer_invalidate_tree(bp); 3647 kfree(bp); 3648 } 3649 3650 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3651 .init = ipv4_inetpeer_init, 3652 .exit = ipv4_inetpeer_exit, 3653 }; 3654 3655 #ifdef CONFIG_IP_ROUTE_CLASSID 3656 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3657 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3658 3659 int __init ip_rt_init(void) 3660 { 3661 void *idents_hash; 3662 int cpu; 3663 3664 /* For modern hosts, this will use 2 MB of memory */ 3665 idents_hash = alloc_large_system_hash("IP idents", 3666 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3667 0, 3668 16, /* one bucket per 64 KB */ 3669 HASH_ZERO, 3670 NULL, 3671 &ip_idents_mask, 3672 2048, 3673 256*1024); 3674 3675 ip_idents = idents_hash; 3676 3677 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3678 3679 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3680 3681 for_each_possible_cpu(cpu) { 3682 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3683 3684 INIT_LIST_HEAD(&ul->head); 3685 spin_lock_init(&ul->lock); 3686 } 3687 #ifdef CONFIG_IP_ROUTE_CLASSID 3688 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3689 if (!ip_rt_acct) 3690 panic("IP: failed to allocate ip_rt_acct\n"); 3691 #endif 3692 3693 ipv4_dst_ops.kmem_cachep = 3694 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3695 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3696 3697 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3698 3699 if (dst_entries_init(&ipv4_dst_ops) < 0) 3700 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3701 3702 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3703 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3704 3705 ipv4_dst_ops.gc_thresh = ~0; 3706 ip_rt_max_size = INT_MAX; 3707 3708 devinet_init(); 3709 ip_fib_init(); 3710 3711 if (ip_rt_proc_init()) 3712 pr_err("Unable to create route proc files\n"); 3713 #ifdef CONFIG_XFRM 3714 xfrm_init(); 3715 xfrm4_init(); 3716 #endif 3717 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3718 RTNL_FLAG_DOIT_UNLOCKED); 3719 3720 #ifdef CONFIG_SYSCTL 3721 register_pernet_subsys(&sysctl_route_ops); 3722 #endif 3723 register_pernet_subsys(&rt_genid_ops); 3724 register_pernet_subsys(&ipv4_inetpeer_ops); 3725 return 0; 3726 } 3727 3728 #ifdef CONFIG_SYSCTL 3729 /* 3730 * We really need to sanitize the damn ipv4 init order, then all 3731 * this nonsense will go away. 3732 */ 3733 void __init ip_static_sysctl_init(void) 3734 { 3735 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3736 } 3737 #endif 3738