1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * ROUTE - implementation of the IP router. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 13 * 14 * Fixes: 15 * Alan Cox : Verify area fixes. 16 * Alan Cox : cli() protects routing changes 17 * Rui Oliveira : ICMP routing table updates 18 * (rco@di.uminho.pt) Routing table insertion and update 19 * Linus Torvalds : Rewrote bits to be sensible 20 * Alan Cox : Added BSD route gw semantics 21 * Alan Cox : Super /proc >4K 22 * Alan Cox : MTU in route table 23 * Alan Cox : MSS actually. Also added the window 24 * clamper. 25 * Sam Lantinga : Fixed route matching in rt_del() 26 * Alan Cox : Routing cache support. 27 * Alan Cox : Removed compatibility cruft. 28 * Alan Cox : RTF_REJECT support. 29 * Alan Cox : TCP irtt support. 30 * Jonathan Naylor : Added Metric support. 31 * Miquel van Smoorenburg : BSD API fixes. 32 * Miquel van Smoorenburg : Metrics. 33 * Alan Cox : Use __u32 properly 34 * Alan Cox : Aligned routing errors more closely with BSD 35 * our system is still very different. 36 * Alan Cox : Faster /proc handling 37 * Alexey Kuznetsov : Massive rework to support tree based routing, 38 * routing caches and better behaviour. 39 * 40 * Olaf Erb : irtt wasn't being copied right. 41 * Bjorn Ekwall : Kerneld route support. 42 * Alan Cox : Multicast fixed (I hope) 43 * Pavel Krauz : Limited broadcast fixed 44 * Mike McLagan : Routing by source 45 * Alexey Kuznetsov : End of old history. Split to fib.c and 46 * route.c and rewritten from scratch. 47 * Andi Kleen : Load-limit warning messages. 48 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 52 * Marc Boucher : routing by fwmark 53 * Robert Olsson : Added rt_cache statistics 54 * Arnaldo C. Melo : Convert proc stuff to seq_file 55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 57 * Ilia Sotnikov : Removed TOS from hash calculations 58 * 59 * This program is free software; you can redistribute it and/or 60 * modify it under the terms of the GNU General Public License 61 * as published by the Free Software Foundation; either version 62 * 2 of the License, or (at your option) any later version. 63 */ 64 65 #define pr_fmt(fmt) "IPv4: " fmt 66 67 #include <linux/module.h> 68 #include <linux/uaccess.h> 69 #include <linux/bitops.h> 70 #include <linux/types.h> 71 #include <linux/kernel.h> 72 #include <linux/mm.h> 73 #include <linux/string.h> 74 #include <linux/socket.h> 75 #include <linux/sockios.h> 76 #include <linux/errno.h> 77 #include <linux/in.h> 78 #include <linux/inet.h> 79 #include <linux/netdevice.h> 80 #include <linux/proc_fs.h> 81 #include <linux/init.h> 82 #include <linux/skbuff.h> 83 #include <linux/inetdevice.h> 84 #include <linux/igmp.h> 85 #include <linux/pkt_sched.h> 86 #include <linux/mroute.h> 87 #include <linux/netfilter_ipv4.h> 88 #include <linux/random.h> 89 #include <linux/rcupdate.h> 90 #include <linux/times.h> 91 #include <linux/slab.h> 92 #include <linux/jhash.h> 93 #include <net/dst.h> 94 #include <net/dst_metadata.h> 95 #include <net/net_namespace.h> 96 #include <net/protocol.h> 97 #include <net/ip.h> 98 #include <net/route.h> 99 #include <net/inetpeer.h> 100 #include <net/sock.h> 101 #include <net/ip_fib.h> 102 #include <net/arp.h> 103 #include <net/tcp.h> 104 #include <net/icmp.h> 105 #include <net/xfrm.h> 106 #include <net/lwtunnel.h> 107 #include <net/netevent.h> 108 #include <net/rtnetlink.h> 109 #ifdef CONFIG_SYSCTL 110 #include <linux/sysctl.h> 111 #endif 112 #include <net/secure_seq.h> 113 #include <net/ip_tunnels.h> 114 #include <net/l3mdev.h> 115 116 #include "fib_lookup.h" 117 118 #define RT_FL_TOS(oldflp4) \ 119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 120 121 #define RT_GC_TIMEOUT (300*HZ) 122 123 static int ip_rt_max_size; 124 static int ip_rt_redirect_number __read_mostly = 9; 125 static int ip_rt_redirect_load __read_mostly = HZ / 50; 126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 127 static int ip_rt_error_cost __read_mostly = HZ; 128 static int ip_rt_error_burst __read_mostly = 5 * HZ; 129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 130 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 131 static int ip_rt_min_advmss __read_mostly = 256; 132 133 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 134 135 /* 136 * Interface to generic destination cache. 137 */ 138 139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 141 static 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 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 147 struct sk_buff *skb); 148 static void ipv4_dst_destroy(struct dst_entry *dst); 149 150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 151 { 152 WARN_ON(1); 153 return NULL; 154 } 155 156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 157 struct sk_buff *skb, 158 const void *daddr); 159 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 160 161 static struct dst_ops ipv4_dst_ops = { 162 .family = AF_INET, 163 .check = ipv4_dst_check, 164 .default_advmss = ipv4_default_advmss, 165 .mtu = ipv4_mtu, 166 .cow_metrics = ipv4_cow_metrics, 167 .destroy = ipv4_dst_destroy, 168 .negative_advice = ipv4_negative_advice, 169 .link_failure = ipv4_link_failure, 170 .update_pmtu = ip_rt_update_pmtu, 171 .redirect = ip_do_redirect, 172 .local_out = __ip_local_out, 173 .neigh_lookup = ipv4_neigh_lookup, 174 .confirm_neigh = ipv4_confirm_neigh, 175 }; 176 177 #define ECN_OR_COST(class) TC_PRIO_##class 178 179 const __u8 ip_tos2prio[16] = { 180 TC_PRIO_BESTEFFORT, 181 ECN_OR_COST(BESTEFFORT), 182 TC_PRIO_BESTEFFORT, 183 ECN_OR_COST(BESTEFFORT), 184 TC_PRIO_BULK, 185 ECN_OR_COST(BULK), 186 TC_PRIO_BULK, 187 ECN_OR_COST(BULK), 188 TC_PRIO_INTERACTIVE, 189 ECN_OR_COST(INTERACTIVE), 190 TC_PRIO_INTERACTIVE, 191 ECN_OR_COST(INTERACTIVE), 192 TC_PRIO_INTERACTIVE_BULK, 193 ECN_OR_COST(INTERACTIVE_BULK), 194 TC_PRIO_INTERACTIVE_BULK, 195 ECN_OR_COST(INTERACTIVE_BULK) 196 }; 197 EXPORT_SYMBOL(ip_tos2prio); 198 199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 200 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 201 202 #ifdef CONFIG_PROC_FS 203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 204 { 205 if (*pos) 206 return NULL; 207 return SEQ_START_TOKEN; 208 } 209 210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 211 { 212 ++*pos; 213 return NULL; 214 } 215 216 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 217 { 218 } 219 220 static int rt_cache_seq_show(struct seq_file *seq, void *v) 221 { 222 if (v == SEQ_START_TOKEN) 223 seq_printf(seq, "%-127s\n", 224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 226 "HHUptod\tSpecDst"); 227 return 0; 228 } 229 230 static const struct seq_operations rt_cache_seq_ops = { 231 .start = rt_cache_seq_start, 232 .next = rt_cache_seq_next, 233 .stop = rt_cache_seq_stop, 234 .show = rt_cache_seq_show, 235 }; 236 237 static int rt_cache_seq_open(struct inode *inode, struct file *file) 238 { 239 return seq_open(file, &rt_cache_seq_ops); 240 } 241 242 static const struct file_operations rt_cache_seq_fops = { 243 .open = rt_cache_seq_open, 244 .read = seq_read, 245 .llseek = seq_lseek, 246 .release = seq_release, 247 }; 248 249 250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 251 { 252 int cpu; 253 254 if (*pos == 0) 255 return SEQ_START_TOKEN; 256 257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 258 if (!cpu_possible(cpu)) 259 continue; 260 *pos = cpu+1; 261 return &per_cpu(rt_cache_stat, cpu); 262 } 263 return NULL; 264 } 265 266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 267 { 268 int cpu; 269 270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 271 if (!cpu_possible(cpu)) 272 continue; 273 *pos = cpu+1; 274 return &per_cpu(rt_cache_stat, cpu); 275 } 276 return NULL; 277 278 } 279 280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 281 { 282 283 } 284 285 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 286 { 287 struct rt_cache_stat *st = v; 288 289 if (v == SEQ_START_TOKEN) { 290 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"); 291 return 0; 292 } 293 294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 296 dst_entries_get_slow(&ipv4_dst_ops), 297 0, /* st->in_hit */ 298 st->in_slow_tot, 299 st->in_slow_mc, 300 st->in_no_route, 301 st->in_brd, 302 st->in_martian_dst, 303 st->in_martian_src, 304 305 0, /* st->out_hit */ 306 st->out_slow_tot, 307 st->out_slow_mc, 308 309 0, /* st->gc_total */ 310 0, /* st->gc_ignored */ 311 0, /* st->gc_goal_miss */ 312 0, /* st->gc_dst_overflow */ 313 0, /* st->in_hlist_search */ 314 0 /* st->out_hlist_search */ 315 ); 316 return 0; 317 } 318 319 static const struct seq_operations rt_cpu_seq_ops = { 320 .start = rt_cpu_seq_start, 321 .next = rt_cpu_seq_next, 322 .stop = rt_cpu_seq_stop, 323 .show = rt_cpu_seq_show, 324 }; 325 326 327 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 328 { 329 return seq_open(file, &rt_cpu_seq_ops); 330 } 331 332 static const struct file_operations rt_cpu_seq_fops = { 333 .open = rt_cpu_seq_open, 334 .read = seq_read, 335 .llseek = seq_lseek, 336 .release = seq_release, 337 }; 338 339 #ifdef CONFIG_IP_ROUTE_CLASSID 340 static int rt_acct_proc_show(struct seq_file *m, void *v) 341 { 342 struct ip_rt_acct *dst, *src; 343 unsigned int i, j; 344 345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 346 if (!dst) 347 return -ENOMEM; 348 349 for_each_possible_cpu(i) { 350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 351 for (j = 0; j < 256; j++) { 352 dst[j].o_bytes += src[j].o_bytes; 353 dst[j].o_packets += src[j].o_packets; 354 dst[j].i_bytes += src[j].i_bytes; 355 dst[j].i_packets += src[j].i_packets; 356 } 357 } 358 359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 360 kfree(dst); 361 return 0; 362 } 363 #endif 364 365 static int __net_init ip_rt_do_proc_init(struct net *net) 366 { 367 struct proc_dir_entry *pde; 368 369 pde = proc_create("rt_cache", 0444, net->proc_net, 370 &rt_cache_seq_fops); 371 if (!pde) 372 goto err1; 373 374 pde = proc_create("rt_cache", 0444, 375 net->proc_net_stat, &rt_cpu_seq_fops); 376 if (!pde) 377 goto err2; 378 379 #ifdef CONFIG_IP_ROUTE_CLASSID 380 pde = proc_create_single("rt_acct", 0, net->proc_net, 381 rt_acct_proc_show); 382 if (!pde) 383 goto err3; 384 #endif 385 return 0; 386 387 #ifdef CONFIG_IP_ROUTE_CLASSID 388 err3: 389 remove_proc_entry("rt_cache", net->proc_net_stat); 390 #endif 391 err2: 392 remove_proc_entry("rt_cache", net->proc_net); 393 err1: 394 return -ENOMEM; 395 } 396 397 static void __net_exit ip_rt_do_proc_exit(struct net *net) 398 { 399 remove_proc_entry("rt_cache", net->proc_net_stat); 400 remove_proc_entry("rt_cache", net->proc_net); 401 #ifdef CONFIG_IP_ROUTE_CLASSID 402 remove_proc_entry("rt_acct", net->proc_net); 403 #endif 404 } 405 406 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 407 .init = ip_rt_do_proc_init, 408 .exit = ip_rt_do_proc_exit, 409 }; 410 411 static int __init ip_rt_proc_init(void) 412 { 413 return register_pernet_subsys(&ip_rt_proc_ops); 414 } 415 416 #else 417 static inline int ip_rt_proc_init(void) 418 { 419 return 0; 420 } 421 #endif /* CONFIG_PROC_FS */ 422 423 static inline bool rt_is_expired(const struct rtable *rth) 424 { 425 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 426 } 427 428 void rt_cache_flush(struct net *net) 429 { 430 rt_genid_bump_ipv4(net); 431 } 432 433 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 434 struct sk_buff *skb, 435 const void *daddr) 436 { 437 struct net_device *dev = dst->dev; 438 const __be32 *pkey = daddr; 439 const struct rtable *rt; 440 struct neighbour *n; 441 442 rt = (const struct rtable *) dst; 443 if (rt->rt_gateway) 444 pkey = (const __be32 *) &rt->rt_gateway; 445 else if (skb) 446 pkey = &ip_hdr(skb)->daddr; 447 448 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 449 if (n) 450 return n; 451 return neigh_create(&arp_tbl, pkey, dev); 452 } 453 454 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 455 { 456 struct net_device *dev = dst->dev; 457 const __be32 *pkey = daddr; 458 const struct rtable *rt; 459 460 rt = (const struct rtable *)dst; 461 if (rt->rt_gateway) 462 pkey = (const __be32 *)&rt->rt_gateway; 463 else if (!daddr || 464 (rt->rt_flags & 465 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) 466 return; 467 468 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 469 } 470 471 #define IP_IDENTS_SZ 2048u 472 473 static atomic_t *ip_idents __read_mostly; 474 static u32 *ip_tstamps __read_mostly; 475 476 /* In order to protect privacy, we add a perturbation to identifiers 477 * if one generator is seldom used. This makes hard for an attacker 478 * to infer how many packets were sent between two points in time. 479 */ 480 u32 ip_idents_reserve(u32 hash, int segs) 481 { 482 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; 483 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; 484 u32 old = READ_ONCE(*p_tstamp); 485 u32 now = (u32)jiffies; 486 u32 new, delta = 0; 487 488 if (old != now && cmpxchg(p_tstamp, old, now) == old) 489 delta = prandom_u32_max(now - old); 490 491 /* Do not use atomic_add_return() as it makes UBSAN unhappy */ 492 do { 493 old = (u32)atomic_read(p_id); 494 new = old + delta + segs; 495 } while (atomic_cmpxchg(p_id, old, new) != old); 496 497 return new - segs; 498 } 499 EXPORT_SYMBOL(ip_idents_reserve); 500 501 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 502 { 503 static u32 ip_idents_hashrnd __read_mostly; 504 u32 hash, id; 505 506 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); 507 508 hash = jhash_3words((__force u32)iph->daddr, 509 (__force u32)iph->saddr, 510 iph->protocol ^ net_hash_mix(net), 511 ip_idents_hashrnd); 512 id = ip_idents_reserve(hash, segs); 513 iph->id = htons(id); 514 } 515 EXPORT_SYMBOL(__ip_select_ident); 516 517 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 518 const struct sock *sk, 519 const struct iphdr *iph, 520 int oif, u8 tos, 521 u8 prot, u32 mark, int flow_flags) 522 { 523 if (sk) { 524 const struct inet_sock *inet = inet_sk(sk); 525 526 oif = sk->sk_bound_dev_if; 527 mark = sk->sk_mark; 528 tos = RT_CONN_FLAGS(sk); 529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 530 } 531 flowi4_init_output(fl4, oif, mark, tos, 532 RT_SCOPE_UNIVERSE, prot, 533 flow_flags, 534 iph->daddr, iph->saddr, 0, 0, 535 sock_net_uid(net, sk)); 536 } 537 538 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 539 const struct sock *sk) 540 { 541 const struct net *net = dev_net(skb->dev); 542 const struct iphdr *iph = ip_hdr(skb); 543 int oif = skb->dev->ifindex; 544 u8 tos = RT_TOS(iph->tos); 545 u8 prot = iph->protocol; 546 u32 mark = skb->mark; 547 548 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 549 } 550 551 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 552 { 553 const struct inet_sock *inet = inet_sk(sk); 554 const struct ip_options_rcu *inet_opt; 555 __be32 daddr = inet->inet_daddr; 556 557 rcu_read_lock(); 558 inet_opt = rcu_dereference(inet->inet_opt); 559 if (inet_opt && inet_opt->opt.srr) 560 daddr = inet_opt->opt.faddr; 561 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 562 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 563 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 564 inet_sk_flowi_flags(sk), 565 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 566 rcu_read_unlock(); 567 } 568 569 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 570 const struct sk_buff *skb) 571 { 572 if (skb) 573 build_skb_flow_key(fl4, skb, sk); 574 else 575 build_sk_flow_key(fl4, sk); 576 } 577 578 static DEFINE_SPINLOCK(fnhe_lock); 579 580 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 581 { 582 struct rtable *rt; 583 584 rt = rcu_dereference(fnhe->fnhe_rth_input); 585 if (rt) { 586 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 587 dst_dev_put(&rt->dst); 588 dst_release(&rt->dst); 589 } 590 rt = rcu_dereference(fnhe->fnhe_rth_output); 591 if (rt) { 592 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 593 dst_dev_put(&rt->dst); 594 dst_release(&rt->dst); 595 } 596 } 597 598 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 599 { 600 struct fib_nh_exception *fnhe, *oldest; 601 602 oldest = rcu_dereference(hash->chain); 603 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 604 fnhe = rcu_dereference(fnhe->fnhe_next)) { 605 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 606 oldest = fnhe; 607 } 608 fnhe_flush_routes(oldest); 609 return oldest; 610 } 611 612 static inline u32 fnhe_hashfun(__be32 daddr) 613 { 614 static u32 fnhe_hashrnd __read_mostly; 615 u32 hval; 616 617 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 618 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 619 return hash_32(hval, FNHE_HASH_SHIFT); 620 } 621 622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 623 { 624 rt->rt_pmtu = fnhe->fnhe_pmtu; 625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 626 rt->dst.expires = fnhe->fnhe_expires; 627 628 if (fnhe->fnhe_gw) { 629 rt->rt_flags |= RTCF_REDIRECTED; 630 rt->rt_gateway = fnhe->fnhe_gw; 631 rt->rt_uses_gateway = 1; 632 } 633 } 634 635 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 636 u32 pmtu, bool lock, unsigned long expires) 637 { 638 struct fnhe_hash_bucket *hash; 639 struct fib_nh_exception *fnhe; 640 struct rtable *rt; 641 u32 genid, hval; 642 unsigned int i; 643 int depth; 644 645 genid = fnhe_genid(dev_net(nh->nh_dev)); 646 hval = fnhe_hashfun(daddr); 647 648 spin_lock_bh(&fnhe_lock); 649 650 hash = rcu_dereference(nh->nh_exceptions); 651 if (!hash) { 652 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 653 if (!hash) 654 goto out_unlock; 655 rcu_assign_pointer(nh->nh_exceptions, hash); 656 } 657 658 hash += hval; 659 660 depth = 0; 661 for (fnhe = rcu_dereference(hash->chain); fnhe; 662 fnhe = rcu_dereference(fnhe->fnhe_next)) { 663 if (fnhe->fnhe_daddr == daddr) 664 break; 665 depth++; 666 } 667 668 if (fnhe) { 669 if (fnhe->fnhe_genid != genid) 670 fnhe->fnhe_genid = genid; 671 if (gw) 672 fnhe->fnhe_gw = gw; 673 if (pmtu) { 674 fnhe->fnhe_pmtu = pmtu; 675 fnhe->fnhe_mtu_locked = lock; 676 } 677 fnhe->fnhe_expires = max(1UL, expires); 678 /* Update all cached dsts too */ 679 rt = rcu_dereference(fnhe->fnhe_rth_input); 680 if (rt) 681 fill_route_from_fnhe(rt, fnhe); 682 rt = rcu_dereference(fnhe->fnhe_rth_output); 683 if (rt) 684 fill_route_from_fnhe(rt, fnhe); 685 } else { 686 if (depth > FNHE_RECLAIM_DEPTH) 687 fnhe = fnhe_oldest(hash); 688 else { 689 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 690 if (!fnhe) 691 goto out_unlock; 692 693 fnhe->fnhe_next = hash->chain; 694 rcu_assign_pointer(hash->chain, fnhe); 695 } 696 fnhe->fnhe_genid = genid; 697 fnhe->fnhe_daddr = daddr; 698 fnhe->fnhe_gw = gw; 699 fnhe->fnhe_pmtu = pmtu; 700 fnhe->fnhe_mtu_locked = lock; 701 fnhe->fnhe_expires = max(1UL, expires); 702 703 /* Exception created; mark the cached routes for the nexthop 704 * stale, so anyone caching it rechecks if this exception 705 * applies to them. 706 */ 707 rt = rcu_dereference(nh->nh_rth_input); 708 if (rt) 709 rt->dst.obsolete = DST_OBSOLETE_KILL; 710 711 for_each_possible_cpu(i) { 712 struct rtable __rcu **prt; 713 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 714 rt = rcu_dereference(*prt); 715 if (rt) 716 rt->dst.obsolete = DST_OBSOLETE_KILL; 717 } 718 } 719 720 fnhe->fnhe_stamp = jiffies; 721 722 out_unlock: 723 spin_unlock_bh(&fnhe_lock); 724 } 725 726 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 727 bool kill_route) 728 { 729 __be32 new_gw = icmp_hdr(skb)->un.gateway; 730 __be32 old_gw = ip_hdr(skb)->saddr; 731 struct net_device *dev = skb->dev; 732 struct in_device *in_dev; 733 struct fib_result res; 734 struct neighbour *n; 735 struct net *net; 736 737 switch (icmp_hdr(skb)->code & 7) { 738 case ICMP_REDIR_NET: 739 case ICMP_REDIR_NETTOS: 740 case ICMP_REDIR_HOST: 741 case ICMP_REDIR_HOSTTOS: 742 break; 743 744 default: 745 return; 746 } 747 748 if (rt->rt_gateway != old_gw) 749 return; 750 751 in_dev = __in_dev_get_rcu(dev); 752 if (!in_dev) 753 return; 754 755 net = dev_net(dev); 756 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 757 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 758 ipv4_is_zeronet(new_gw)) 759 goto reject_redirect; 760 761 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 762 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 763 goto reject_redirect; 764 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 765 goto reject_redirect; 766 } else { 767 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 768 goto reject_redirect; 769 } 770 771 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 772 if (!n) 773 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 774 if (!IS_ERR(n)) { 775 if (!(n->nud_state & NUD_VALID)) { 776 neigh_event_send(n, NULL); 777 } else { 778 if (fib_lookup(net, fl4, &res, 0) == 0) { 779 struct fib_nh *nh = &FIB_RES_NH(res); 780 781 update_or_create_fnhe(nh, fl4->daddr, new_gw, 782 0, false, 783 jiffies + ip_rt_gc_timeout); 784 } 785 if (kill_route) 786 rt->dst.obsolete = DST_OBSOLETE_KILL; 787 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 788 } 789 neigh_release(n); 790 } 791 return; 792 793 reject_redirect: 794 #ifdef CONFIG_IP_ROUTE_VERBOSE 795 if (IN_DEV_LOG_MARTIANS(in_dev)) { 796 const struct iphdr *iph = (const struct iphdr *) skb->data; 797 __be32 daddr = iph->daddr; 798 __be32 saddr = iph->saddr; 799 800 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 801 " Advised path = %pI4 -> %pI4\n", 802 &old_gw, dev->name, &new_gw, 803 &saddr, &daddr); 804 } 805 #endif 806 ; 807 } 808 809 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 810 { 811 struct rtable *rt; 812 struct flowi4 fl4; 813 const struct iphdr *iph = (const struct iphdr *) skb->data; 814 struct net *net = dev_net(skb->dev); 815 int oif = skb->dev->ifindex; 816 u8 tos = RT_TOS(iph->tos); 817 u8 prot = iph->protocol; 818 u32 mark = skb->mark; 819 820 rt = (struct rtable *) dst; 821 822 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 823 __ip_do_redirect(rt, skb, &fl4, true); 824 } 825 826 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 827 { 828 struct rtable *rt = (struct rtable *)dst; 829 struct dst_entry *ret = dst; 830 831 if (rt) { 832 if (dst->obsolete > 0) { 833 ip_rt_put(rt); 834 ret = NULL; 835 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 836 rt->dst.expires) { 837 ip_rt_put(rt); 838 ret = NULL; 839 } 840 } 841 return ret; 842 } 843 844 /* 845 * Algorithm: 846 * 1. The first ip_rt_redirect_number redirects are sent 847 * with exponential backoff, then we stop sending them at all, 848 * assuming that the host ignores our redirects. 849 * 2. If we did not see packets requiring redirects 850 * during ip_rt_redirect_silence, we assume that the host 851 * forgot redirected route and start to send redirects again. 852 * 853 * This algorithm is much cheaper and more intelligent than dumb load limiting 854 * in icmp.c. 855 * 856 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 857 * and "frag. need" (breaks PMTU discovery) in icmp.c. 858 */ 859 860 void ip_rt_send_redirect(struct sk_buff *skb) 861 { 862 struct rtable *rt = skb_rtable(skb); 863 struct in_device *in_dev; 864 struct inet_peer *peer; 865 struct net *net; 866 int log_martians; 867 int vif; 868 869 rcu_read_lock(); 870 in_dev = __in_dev_get_rcu(rt->dst.dev); 871 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 872 rcu_read_unlock(); 873 return; 874 } 875 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 876 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 877 rcu_read_unlock(); 878 879 net = dev_net(rt->dst.dev); 880 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 881 if (!peer) { 882 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 883 rt_nexthop(rt, ip_hdr(skb)->daddr)); 884 return; 885 } 886 887 /* No redirected packets during ip_rt_redirect_silence; 888 * reset the algorithm. 889 */ 890 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 891 peer->rate_tokens = 0; 892 893 /* Too many ignored redirects; do not send anything 894 * set dst.rate_last to the last seen redirected packet. 895 */ 896 if (peer->rate_tokens >= ip_rt_redirect_number) { 897 peer->rate_last = jiffies; 898 goto out_put_peer; 899 } 900 901 /* Check for load limit; set rate_last to the latest sent 902 * redirect. 903 */ 904 if (peer->rate_tokens == 0 || 905 time_after(jiffies, 906 (peer->rate_last + 907 (ip_rt_redirect_load << peer->rate_tokens)))) { 908 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 909 910 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 911 peer->rate_last = jiffies; 912 ++peer->rate_tokens; 913 #ifdef CONFIG_IP_ROUTE_VERBOSE 914 if (log_martians && 915 peer->rate_tokens == ip_rt_redirect_number) 916 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 917 &ip_hdr(skb)->saddr, inet_iif(skb), 918 &ip_hdr(skb)->daddr, &gw); 919 #endif 920 } 921 out_put_peer: 922 inet_putpeer(peer); 923 } 924 925 static int ip_error(struct sk_buff *skb) 926 { 927 struct rtable *rt = skb_rtable(skb); 928 struct net_device *dev = skb->dev; 929 struct in_device *in_dev; 930 struct inet_peer *peer; 931 unsigned long now; 932 struct net *net; 933 bool send; 934 int code; 935 936 if (netif_is_l3_master(skb->dev)) { 937 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 938 if (!dev) 939 goto out; 940 } 941 942 in_dev = __in_dev_get_rcu(dev); 943 944 /* IP on this device is disabled. */ 945 if (!in_dev) 946 goto out; 947 948 net = dev_net(rt->dst.dev); 949 if (!IN_DEV_FORWARD(in_dev)) { 950 switch (rt->dst.error) { 951 case EHOSTUNREACH: 952 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 953 break; 954 955 case ENETUNREACH: 956 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 957 break; 958 } 959 goto out; 960 } 961 962 switch (rt->dst.error) { 963 case EINVAL: 964 default: 965 goto out; 966 case EHOSTUNREACH: 967 code = ICMP_HOST_UNREACH; 968 break; 969 case ENETUNREACH: 970 code = ICMP_NET_UNREACH; 971 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 972 break; 973 case EACCES: 974 code = ICMP_PKT_FILTERED; 975 break; 976 } 977 978 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 979 l3mdev_master_ifindex(skb->dev), 1); 980 981 send = true; 982 if (peer) { 983 now = jiffies; 984 peer->rate_tokens += now - peer->rate_last; 985 if (peer->rate_tokens > ip_rt_error_burst) 986 peer->rate_tokens = ip_rt_error_burst; 987 peer->rate_last = now; 988 if (peer->rate_tokens >= ip_rt_error_cost) 989 peer->rate_tokens -= ip_rt_error_cost; 990 else 991 send = false; 992 inet_putpeer(peer); 993 } 994 if (send) 995 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 996 997 out: kfree_skb(skb); 998 return 0; 999 } 1000 1001 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1002 { 1003 struct dst_entry *dst = &rt->dst; 1004 u32 old_mtu = ipv4_mtu(dst); 1005 struct fib_result res; 1006 bool lock = false; 1007 1008 if (ip_mtu_locked(dst)) 1009 return; 1010 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(dev_net(dst->dev), fl4, &res, 0) == 0) { 1025 struct fib_nh *nh = &FIB_RES_NH(res); 1026 1027 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock, 1028 jiffies + ip_rt_mtu_expires); 1029 } 1030 rcu_read_unlock(); 1031 } 1032 1033 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1034 struct sk_buff *skb, u32 mtu) 1035 { 1036 struct rtable *rt = (struct rtable *) dst; 1037 struct flowi4 fl4; 1038 1039 ip_rt_build_flow_key(&fl4, sk, skb); 1040 __ip_rt_update_pmtu(rt, &fl4, mtu); 1041 } 1042 1043 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1044 int oif, u32 mark, u8 protocol, int flow_flags) 1045 { 1046 const struct iphdr *iph = (const struct iphdr *) skb->data; 1047 struct flowi4 fl4; 1048 struct rtable *rt; 1049 1050 if (!mark) 1051 mark = IP4_REPLY_MARK(net, skb->mark); 1052 1053 __build_flow_key(net, &fl4, NULL, iph, oif, 1054 RT_TOS(iph->tos), protocol, mark, flow_flags); 1055 rt = __ip_route_output_key(net, &fl4); 1056 if (!IS_ERR(rt)) { 1057 __ip_rt_update_pmtu(rt, &fl4, mtu); 1058 ip_rt_put(rt); 1059 } 1060 } 1061 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1062 1063 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1064 { 1065 const struct iphdr *iph = (const struct iphdr *) skb->data; 1066 struct flowi4 fl4; 1067 struct rtable *rt; 1068 1069 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1070 1071 if (!fl4.flowi4_mark) 1072 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1073 1074 rt = __ip_route_output_key(sock_net(sk), &fl4); 1075 if (!IS_ERR(rt)) { 1076 __ip_rt_update_pmtu(rt, &fl4, mtu); 1077 ip_rt_put(rt); 1078 } 1079 } 1080 1081 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1082 { 1083 const struct iphdr *iph = (const struct iphdr *) skb->data; 1084 struct flowi4 fl4; 1085 struct rtable *rt; 1086 struct dst_entry *odst = NULL; 1087 bool new = false; 1088 struct net *net = sock_net(sk); 1089 1090 bh_lock_sock(sk); 1091 1092 if (!ip_sk_accept_pmtu(sk)) 1093 goto out; 1094 1095 odst = sk_dst_get(sk); 1096 1097 if (sock_owned_by_user(sk) || !odst) { 1098 __ipv4_sk_update_pmtu(skb, sk, mtu); 1099 goto out; 1100 } 1101 1102 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1103 1104 rt = (struct rtable *)odst; 1105 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1106 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1107 if (IS_ERR(rt)) 1108 goto out; 1109 1110 new = true; 1111 } 1112 1113 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu); 1114 1115 if (!dst_check(&rt->dst, 0)) { 1116 if (new) 1117 dst_release(&rt->dst); 1118 1119 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1120 if (IS_ERR(rt)) 1121 goto out; 1122 1123 new = true; 1124 } 1125 1126 if (new) 1127 sk_dst_set(sk, &rt->dst); 1128 1129 out: 1130 bh_unlock_sock(sk); 1131 dst_release(odst); 1132 } 1133 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1134 1135 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1136 int oif, u32 mark, u8 protocol, int flow_flags) 1137 { 1138 const struct iphdr *iph = (const struct iphdr *) skb->data; 1139 struct flowi4 fl4; 1140 struct rtable *rt; 1141 1142 __build_flow_key(net, &fl4, NULL, iph, oif, 1143 RT_TOS(iph->tos), protocol, mark, flow_flags); 1144 rt = __ip_route_output_key(net, &fl4); 1145 if (!IS_ERR(rt)) { 1146 __ip_do_redirect(rt, skb, &fl4, false); 1147 ip_rt_put(rt); 1148 } 1149 } 1150 EXPORT_SYMBOL_GPL(ipv4_redirect); 1151 1152 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1153 { 1154 const struct iphdr *iph = (const struct iphdr *) skb->data; 1155 struct flowi4 fl4; 1156 struct rtable *rt; 1157 struct net *net = sock_net(sk); 1158 1159 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1160 rt = __ip_route_output_key(net, &fl4); 1161 if (!IS_ERR(rt)) { 1162 __ip_do_redirect(rt, skb, &fl4, false); 1163 ip_rt_put(rt); 1164 } 1165 } 1166 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1167 1168 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1169 { 1170 struct rtable *rt = (struct rtable *) dst; 1171 1172 /* All IPV4 dsts are created with ->obsolete set to the value 1173 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1174 * into this function always. 1175 * 1176 * When a PMTU/redirect information update invalidates a route, 1177 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1178 * DST_OBSOLETE_DEAD by dst_free(). 1179 */ 1180 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1181 return NULL; 1182 return dst; 1183 } 1184 1185 static void ipv4_link_failure(struct sk_buff *skb) 1186 { 1187 struct rtable *rt; 1188 1189 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1190 1191 rt = skb_rtable(skb); 1192 if (rt) 1193 dst_set_expires(&rt->dst, 0); 1194 } 1195 1196 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1197 { 1198 pr_debug("%s: %pI4 -> %pI4, %s\n", 1199 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1200 skb->dev ? skb->dev->name : "?"); 1201 kfree_skb(skb); 1202 WARN_ON(1); 1203 return 0; 1204 } 1205 1206 /* 1207 We do not cache source address of outgoing interface, 1208 because it is used only by IP RR, TS and SRR options, 1209 so that it out of fast path. 1210 1211 BTW remember: "addr" is allowed to be not aligned 1212 in IP options! 1213 */ 1214 1215 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1216 { 1217 __be32 src; 1218 1219 if (rt_is_output_route(rt)) 1220 src = ip_hdr(skb)->saddr; 1221 else { 1222 struct fib_result res; 1223 struct flowi4 fl4; 1224 struct iphdr *iph; 1225 1226 iph = ip_hdr(skb); 1227 1228 memset(&fl4, 0, sizeof(fl4)); 1229 fl4.daddr = iph->daddr; 1230 fl4.saddr = iph->saddr; 1231 fl4.flowi4_tos = RT_TOS(iph->tos); 1232 fl4.flowi4_oif = rt->dst.dev->ifindex; 1233 fl4.flowi4_iif = skb->dev->ifindex; 1234 fl4.flowi4_mark = skb->mark; 1235 1236 rcu_read_lock(); 1237 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1238 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1239 else 1240 src = inet_select_addr(rt->dst.dev, 1241 rt_nexthop(rt, iph->daddr), 1242 RT_SCOPE_UNIVERSE); 1243 rcu_read_unlock(); 1244 } 1245 memcpy(addr, &src, 4); 1246 } 1247 1248 #ifdef CONFIG_IP_ROUTE_CLASSID 1249 static void set_class_tag(struct rtable *rt, u32 tag) 1250 { 1251 if (!(rt->dst.tclassid & 0xFFFF)) 1252 rt->dst.tclassid |= tag & 0xFFFF; 1253 if (!(rt->dst.tclassid & 0xFFFF0000)) 1254 rt->dst.tclassid |= tag & 0xFFFF0000; 1255 } 1256 #endif 1257 1258 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1259 { 1260 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1261 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1262 ip_rt_min_advmss); 1263 1264 return min(advmss, IPV4_MAX_PMTU - header_size); 1265 } 1266 1267 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1268 { 1269 const struct rtable *rt = (const struct rtable *) dst; 1270 unsigned int mtu = rt->rt_pmtu; 1271 1272 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1273 mtu = dst_metric_raw(dst, RTAX_MTU); 1274 1275 if (mtu) 1276 return mtu; 1277 1278 mtu = READ_ONCE(dst->dev->mtu); 1279 1280 if (unlikely(ip_mtu_locked(dst))) { 1281 if (rt->rt_uses_gateway && mtu > 576) 1282 mtu = 576; 1283 } 1284 1285 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1286 1287 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1288 } 1289 1290 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr) 1291 { 1292 struct fnhe_hash_bucket *hash; 1293 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1294 u32 hval = fnhe_hashfun(daddr); 1295 1296 spin_lock_bh(&fnhe_lock); 1297 1298 hash = rcu_dereference_protected(nh->nh_exceptions, 1299 lockdep_is_held(&fnhe_lock)); 1300 hash += hval; 1301 1302 fnhe_p = &hash->chain; 1303 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1304 while (fnhe) { 1305 if (fnhe->fnhe_daddr == daddr) { 1306 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1307 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1308 fnhe_flush_routes(fnhe); 1309 kfree_rcu(fnhe, rcu); 1310 break; 1311 } 1312 fnhe_p = &fnhe->fnhe_next; 1313 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1314 lockdep_is_held(&fnhe_lock)); 1315 } 1316 1317 spin_unlock_bh(&fnhe_lock); 1318 } 1319 1320 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1321 { 1322 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1323 struct fib_nh_exception *fnhe; 1324 u32 hval; 1325 1326 if (!hash) 1327 return NULL; 1328 1329 hval = fnhe_hashfun(daddr); 1330 1331 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1332 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1333 if (fnhe->fnhe_daddr == daddr) { 1334 if (fnhe->fnhe_expires && 1335 time_after(jiffies, fnhe->fnhe_expires)) { 1336 ip_del_fnhe(nh, daddr); 1337 break; 1338 } 1339 return fnhe; 1340 } 1341 } 1342 return NULL; 1343 } 1344 1345 /* MTU selection: 1346 * 1. mtu on route is locked - use it 1347 * 2. mtu from nexthop exception 1348 * 3. mtu from egress device 1349 */ 1350 1351 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1352 { 1353 struct fib_info *fi = res->fi; 1354 struct fib_nh *nh = &fi->fib_nh[res->nh_sel]; 1355 struct net_device *dev = nh->nh_dev; 1356 u32 mtu = 0; 1357 1358 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1359 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1360 mtu = fi->fib_mtu; 1361 1362 if (likely(!mtu)) { 1363 struct fib_nh_exception *fnhe; 1364 1365 fnhe = find_exception(nh, daddr); 1366 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1367 mtu = fnhe->fnhe_pmtu; 1368 } 1369 1370 if (likely(!mtu)) 1371 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1372 1373 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu); 1374 } 1375 1376 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1377 __be32 daddr, const bool do_cache) 1378 { 1379 bool ret = false; 1380 1381 spin_lock_bh(&fnhe_lock); 1382 1383 if (daddr == fnhe->fnhe_daddr) { 1384 struct rtable __rcu **porig; 1385 struct rtable *orig; 1386 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1387 1388 if (rt_is_input_route(rt)) 1389 porig = &fnhe->fnhe_rth_input; 1390 else 1391 porig = &fnhe->fnhe_rth_output; 1392 orig = rcu_dereference(*porig); 1393 1394 if (fnhe->fnhe_genid != genid) { 1395 fnhe->fnhe_genid = genid; 1396 fnhe->fnhe_gw = 0; 1397 fnhe->fnhe_pmtu = 0; 1398 fnhe->fnhe_expires = 0; 1399 fnhe->fnhe_mtu_locked = false; 1400 fnhe_flush_routes(fnhe); 1401 orig = NULL; 1402 } 1403 fill_route_from_fnhe(rt, fnhe); 1404 if (!rt->rt_gateway) 1405 rt->rt_gateway = daddr; 1406 1407 if (do_cache) { 1408 dst_hold(&rt->dst); 1409 rcu_assign_pointer(*porig, rt); 1410 if (orig) { 1411 dst_dev_put(&orig->dst); 1412 dst_release(&orig->dst); 1413 } 1414 ret = true; 1415 } 1416 1417 fnhe->fnhe_stamp = jiffies; 1418 } 1419 spin_unlock_bh(&fnhe_lock); 1420 1421 return ret; 1422 } 1423 1424 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1425 { 1426 struct rtable *orig, *prev, **p; 1427 bool ret = true; 1428 1429 if (rt_is_input_route(rt)) { 1430 p = (struct rtable **)&nh->nh_rth_input; 1431 } else { 1432 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1433 } 1434 orig = *p; 1435 1436 /* hold dst before doing cmpxchg() to avoid race condition 1437 * on this dst 1438 */ 1439 dst_hold(&rt->dst); 1440 prev = cmpxchg(p, orig, rt); 1441 if (prev == orig) { 1442 if (orig) { 1443 dst_dev_put(&orig->dst); 1444 dst_release(&orig->dst); 1445 } 1446 } else { 1447 dst_release(&rt->dst); 1448 ret = false; 1449 } 1450 1451 return ret; 1452 } 1453 1454 struct uncached_list { 1455 spinlock_t lock; 1456 struct list_head head; 1457 }; 1458 1459 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1460 1461 void rt_add_uncached_list(struct rtable *rt) 1462 { 1463 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1464 1465 rt->rt_uncached_list = ul; 1466 1467 spin_lock_bh(&ul->lock); 1468 list_add_tail(&rt->rt_uncached, &ul->head); 1469 spin_unlock_bh(&ul->lock); 1470 } 1471 1472 void rt_del_uncached_list(struct rtable *rt) 1473 { 1474 if (!list_empty(&rt->rt_uncached)) { 1475 struct uncached_list *ul = rt->rt_uncached_list; 1476 1477 spin_lock_bh(&ul->lock); 1478 list_del(&rt->rt_uncached); 1479 spin_unlock_bh(&ul->lock); 1480 } 1481 } 1482 1483 static void ipv4_dst_destroy(struct dst_entry *dst) 1484 { 1485 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst); 1486 struct rtable *rt = (struct rtable *)dst; 1487 1488 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt)) 1489 kfree(p); 1490 1491 rt_del_uncached_list(rt); 1492 } 1493 1494 void rt_flush_dev(struct net_device *dev) 1495 { 1496 struct net *net = dev_net(dev); 1497 struct rtable *rt; 1498 int cpu; 1499 1500 for_each_possible_cpu(cpu) { 1501 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1502 1503 spin_lock_bh(&ul->lock); 1504 list_for_each_entry(rt, &ul->head, rt_uncached) { 1505 if (rt->dst.dev != dev) 1506 continue; 1507 rt->dst.dev = net->loopback_dev; 1508 dev_hold(rt->dst.dev); 1509 dev_put(dev); 1510 } 1511 spin_unlock_bh(&ul->lock); 1512 } 1513 } 1514 1515 static bool rt_cache_valid(const struct rtable *rt) 1516 { 1517 return rt && 1518 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1519 !rt_is_expired(rt); 1520 } 1521 1522 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1523 const struct fib_result *res, 1524 struct fib_nh_exception *fnhe, 1525 struct fib_info *fi, u16 type, u32 itag, 1526 const bool do_cache) 1527 { 1528 bool cached = false; 1529 1530 if (fi) { 1531 struct fib_nh *nh = &FIB_RES_NH(*res); 1532 1533 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1534 rt->rt_gateway = nh->nh_gw; 1535 rt->rt_uses_gateway = 1; 1536 } 1537 dst_init_metrics(&rt->dst, fi->fib_metrics->metrics, true); 1538 if (fi->fib_metrics != &dst_default_metrics) { 1539 rt->dst._metrics |= DST_METRICS_REFCOUNTED; 1540 refcount_inc(&fi->fib_metrics->refcnt); 1541 } 1542 #ifdef CONFIG_IP_ROUTE_CLASSID 1543 rt->dst.tclassid = nh->nh_tclassid; 1544 #endif 1545 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 1546 if (unlikely(fnhe)) 1547 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1548 else if (do_cache) 1549 cached = rt_cache_route(nh, rt); 1550 if (unlikely(!cached)) { 1551 /* Routes we intend to cache in nexthop exception or 1552 * FIB nexthop have the DST_NOCACHE bit clear. 1553 * However, if we are unsuccessful at storing this 1554 * route into the cache we really need to set it. 1555 */ 1556 if (!rt->rt_gateway) 1557 rt->rt_gateway = daddr; 1558 rt_add_uncached_list(rt); 1559 } 1560 } else 1561 rt_add_uncached_list(rt); 1562 1563 #ifdef CONFIG_IP_ROUTE_CLASSID 1564 #ifdef CONFIG_IP_MULTIPLE_TABLES 1565 set_class_tag(rt, res->tclassid); 1566 #endif 1567 set_class_tag(rt, itag); 1568 #endif 1569 } 1570 1571 struct rtable *rt_dst_alloc(struct net_device *dev, 1572 unsigned int flags, u16 type, 1573 bool nopolicy, bool noxfrm, bool will_cache) 1574 { 1575 struct rtable *rt; 1576 1577 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1578 (will_cache ? 0 : DST_HOST) | 1579 (nopolicy ? DST_NOPOLICY : 0) | 1580 (noxfrm ? DST_NOXFRM : 0)); 1581 1582 if (rt) { 1583 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1584 rt->rt_flags = flags; 1585 rt->rt_type = type; 1586 rt->rt_is_input = 0; 1587 rt->rt_iif = 0; 1588 rt->rt_pmtu = 0; 1589 rt->rt_mtu_locked = 0; 1590 rt->rt_gateway = 0; 1591 rt->rt_uses_gateway = 0; 1592 INIT_LIST_HEAD(&rt->rt_uncached); 1593 1594 rt->dst.output = ip_output; 1595 if (flags & RTCF_LOCAL) 1596 rt->dst.input = ip_local_deliver; 1597 } 1598 1599 return rt; 1600 } 1601 EXPORT_SYMBOL(rt_dst_alloc); 1602 1603 /* called in rcu_read_lock() section */ 1604 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1605 u8 tos, struct net_device *dev, 1606 struct in_device *in_dev, u32 *itag) 1607 { 1608 int err; 1609 1610 /* Primary sanity checks. */ 1611 if (!in_dev) 1612 return -EINVAL; 1613 1614 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1615 skb->protocol != htons(ETH_P_IP)) 1616 return -EINVAL; 1617 1618 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1619 return -EINVAL; 1620 1621 if (ipv4_is_zeronet(saddr)) { 1622 if (!ipv4_is_local_multicast(daddr)) 1623 return -EINVAL; 1624 } else { 1625 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1626 in_dev, itag); 1627 if (err < 0) 1628 return err; 1629 } 1630 return 0; 1631 } 1632 1633 /* called in rcu_read_lock() section */ 1634 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1635 u8 tos, struct net_device *dev, int our) 1636 { 1637 struct in_device *in_dev = __in_dev_get_rcu(dev); 1638 unsigned int flags = RTCF_MULTICAST; 1639 struct rtable *rth; 1640 u32 itag = 0; 1641 int err; 1642 1643 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1644 if (err) 1645 return err; 1646 1647 if (our) 1648 flags |= RTCF_LOCAL; 1649 1650 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1651 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1652 if (!rth) 1653 return -ENOBUFS; 1654 1655 #ifdef CONFIG_IP_ROUTE_CLASSID 1656 rth->dst.tclassid = itag; 1657 #endif 1658 rth->dst.output = ip_rt_bug; 1659 rth->rt_is_input= 1; 1660 1661 #ifdef CONFIG_IP_MROUTE 1662 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1663 rth->dst.input = ip_mr_input; 1664 #endif 1665 RT_CACHE_STAT_INC(in_slow_mc); 1666 1667 skb_dst_set(skb, &rth->dst); 1668 return 0; 1669 } 1670 1671 1672 static void ip_handle_martian_source(struct net_device *dev, 1673 struct in_device *in_dev, 1674 struct sk_buff *skb, 1675 __be32 daddr, 1676 __be32 saddr) 1677 { 1678 RT_CACHE_STAT_INC(in_martian_src); 1679 #ifdef CONFIG_IP_ROUTE_VERBOSE 1680 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1681 /* 1682 * RFC1812 recommendation, if source is martian, 1683 * the only hint is MAC header. 1684 */ 1685 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1686 &daddr, &saddr, dev->name); 1687 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1688 print_hex_dump(KERN_WARNING, "ll header: ", 1689 DUMP_PREFIX_OFFSET, 16, 1, 1690 skb_mac_header(skb), 1691 dev->hard_header_len, true); 1692 } 1693 } 1694 #endif 1695 } 1696 1697 /* called in rcu_read_lock() section */ 1698 static int __mkroute_input(struct sk_buff *skb, 1699 const struct fib_result *res, 1700 struct in_device *in_dev, 1701 __be32 daddr, __be32 saddr, u32 tos) 1702 { 1703 struct fib_nh_exception *fnhe; 1704 struct rtable *rth; 1705 int err; 1706 struct in_device *out_dev; 1707 bool do_cache; 1708 u32 itag = 0; 1709 1710 /* get a working reference to the output device */ 1711 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1712 if (!out_dev) { 1713 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1714 return -EINVAL; 1715 } 1716 1717 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1718 in_dev->dev, in_dev, &itag); 1719 if (err < 0) { 1720 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1721 saddr); 1722 1723 goto cleanup; 1724 } 1725 1726 do_cache = res->fi && !itag; 1727 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1728 skb->protocol == htons(ETH_P_IP) && 1729 (IN_DEV_SHARED_MEDIA(out_dev) || 1730 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1731 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1732 1733 if (skb->protocol != htons(ETH_P_IP)) { 1734 /* Not IP (i.e. ARP). Do not create route, if it is 1735 * invalid for proxy arp. DNAT routes are always valid. 1736 * 1737 * Proxy arp feature have been extended to allow, ARP 1738 * replies back to the same interface, to support 1739 * Private VLAN switch technologies. See arp.c. 1740 */ 1741 if (out_dev == in_dev && 1742 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1743 err = -EINVAL; 1744 goto cleanup; 1745 } 1746 } 1747 1748 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1749 if (do_cache) { 1750 if (fnhe) 1751 rth = rcu_dereference(fnhe->fnhe_rth_input); 1752 else 1753 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1754 if (rt_cache_valid(rth)) { 1755 skb_dst_set_noref(skb, &rth->dst); 1756 goto out; 1757 } 1758 } 1759 1760 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1761 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1762 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1763 if (!rth) { 1764 err = -ENOBUFS; 1765 goto cleanup; 1766 } 1767 1768 rth->rt_is_input = 1; 1769 RT_CACHE_STAT_INC(in_slow_tot); 1770 1771 rth->dst.input = ip_forward; 1772 1773 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1774 do_cache); 1775 lwtunnel_set_redirect(&rth->dst); 1776 skb_dst_set(skb, &rth->dst); 1777 out: 1778 err = 0; 1779 cleanup: 1780 return err; 1781 } 1782 1783 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1784 /* To make ICMP packets follow the right flow, the multipath hash is 1785 * calculated from the inner IP addresses. 1786 */ 1787 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1788 struct flow_keys *hash_keys) 1789 { 1790 const struct iphdr *outer_iph = ip_hdr(skb); 1791 const struct iphdr *key_iph = outer_iph; 1792 const struct iphdr *inner_iph; 1793 const struct icmphdr *icmph; 1794 struct iphdr _inner_iph; 1795 struct icmphdr _icmph; 1796 1797 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1798 goto out; 1799 1800 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1801 goto out; 1802 1803 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1804 &_icmph); 1805 if (!icmph) 1806 goto out; 1807 1808 if (icmph->type != ICMP_DEST_UNREACH && 1809 icmph->type != ICMP_REDIRECT && 1810 icmph->type != ICMP_TIME_EXCEEDED && 1811 icmph->type != ICMP_PARAMETERPROB) 1812 goto out; 1813 1814 inner_iph = skb_header_pointer(skb, 1815 outer_iph->ihl * 4 + sizeof(_icmph), 1816 sizeof(_inner_iph), &_inner_iph); 1817 if (!inner_iph) 1818 goto out; 1819 1820 key_iph = inner_iph; 1821 out: 1822 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1823 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1824 } 1825 1826 /* if skb is set it will be used and fl4 can be NULL */ 1827 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 1828 const struct sk_buff *skb, struct flow_keys *flkeys) 1829 { 1830 struct flow_keys hash_keys; 1831 u32 mhash; 1832 1833 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 1834 case 0: 1835 memset(&hash_keys, 0, sizeof(hash_keys)); 1836 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1837 if (skb) { 1838 ip_multipath_l3_keys(skb, &hash_keys); 1839 } else { 1840 hash_keys.addrs.v4addrs.src = fl4->saddr; 1841 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1842 } 1843 break; 1844 case 1: 1845 /* skb is currently provided only when forwarding */ 1846 if (skb) { 1847 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 1848 struct flow_keys keys; 1849 1850 /* short-circuit if we already have L4 hash present */ 1851 if (skb->l4_hash) 1852 return skb_get_hash_raw(skb) >> 1; 1853 1854 memset(&hash_keys, 0, sizeof(hash_keys)); 1855 1856 if (!flkeys) { 1857 skb_flow_dissect_flow_keys(skb, &keys, flag); 1858 flkeys = &keys; 1859 } 1860 1861 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1862 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 1863 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 1864 hash_keys.ports.src = flkeys->ports.src; 1865 hash_keys.ports.dst = flkeys->ports.dst; 1866 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 1867 } else { 1868 memset(&hash_keys, 0, sizeof(hash_keys)); 1869 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1870 hash_keys.addrs.v4addrs.src = fl4->saddr; 1871 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1872 hash_keys.ports.src = fl4->fl4_sport; 1873 hash_keys.ports.dst = fl4->fl4_dport; 1874 hash_keys.basic.ip_proto = fl4->flowi4_proto; 1875 } 1876 break; 1877 } 1878 mhash = flow_hash_from_keys(&hash_keys); 1879 1880 return mhash >> 1; 1881 } 1882 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1883 1884 static int ip_mkroute_input(struct sk_buff *skb, 1885 struct fib_result *res, 1886 struct in_device *in_dev, 1887 __be32 daddr, __be32 saddr, u32 tos, 1888 struct flow_keys *hkeys) 1889 { 1890 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1891 if (res->fi && res->fi->fib_nhs > 1) { 1892 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1893 1894 fib_select_multipath(res, h); 1895 } 1896 #endif 1897 1898 /* create a routing cache entry */ 1899 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1900 } 1901 1902 /* 1903 * NOTE. We drop all the packets that has local source 1904 * addresses, because every properly looped back packet 1905 * must have correct destination already attached by output routine. 1906 * 1907 * Such approach solves two big problems: 1908 * 1. Not simplex devices are handled properly. 1909 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1910 * called with rcu_read_lock() 1911 */ 1912 1913 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1914 u8 tos, struct net_device *dev, 1915 struct fib_result *res) 1916 { 1917 struct in_device *in_dev = __in_dev_get_rcu(dev); 1918 struct flow_keys *flkeys = NULL, _flkeys; 1919 struct net *net = dev_net(dev); 1920 struct ip_tunnel_info *tun_info; 1921 int err = -EINVAL; 1922 unsigned int flags = 0; 1923 u32 itag = 0; 1924 struct rtable *rth; 1925 struct flowi4 fl4; 1926 bool do_cache; 1927 1928 /* IP on this device is disabled. */ 1929 1930 if (!in_dev) 1931 goto out; 1932 1933 /* Check for the most weird martians, which can be not detected 1934 by fib_lookup. 1935 */ 1936 1937 tun_info = skb_tunnel_info(skb); 1938 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1939 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1940 else 1941 fl4.flowi4_tun_key.tun_id = 0; 1942 skb_dst_drop(skb); 1943 1944 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1945 goto martian_source; 1946 1947 res->fi = NULL; 1948 res->table = NULL; 1949 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1950 goto brd_input; 1951 1952 /* Accept zero addresses only to limited broadcast; 1953 * I even do not know to fix it or not. Waiting for complains :-) 1954 */ 1955 if (ipv4_is_zeronet(saddr)) 1956 goto martian_source; 1957 1958 if (ipv4_is_zeronet(daddr)) 1959 goto martian_destination; 1960 1961 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1962 * and call it once if daddr or/and saddr are loopback addresses 1963 */ 1964 if (ipv4_is_loopback(daddr)) { 1965 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1966 goto martian_destination; 1967 } else if (ipv4_is_loopback(saddr)) { 1968 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1969 goto martian_source; 1970 } 1971 1972 /* 1973 * Now we are ready to route packet. 1974 */ 1975 fl4.flowi4_oif = 0; 1976 fl4.flowi4_iif = dev->ifindex; 1977 fl4.flowi4_mark = skb->mark; 1978 fl4.flowi4_tos = tos; 1979 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1980 fl4.flowi4_flags = 0; 1981 fl4.daddr = daddr; 1982 fl4.saddr = saddr; 1983 fl4.flowi4_uid = sock_net_uid(net, NULL); 1984 1985 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 1986 flkeys = &_flkeys; 1987 } else { 1988 fl4.flowi4_proto = 0; 1989 fl4.fl4_sport = 0; 1990 fl4.fl4_dport = 0; 1991 } 1992 1993 err = fib_lookup(net, &fl4, res, 0); 1994 if (err != 0) { 1995 if (!IN_DEV_FORWARD(in_dev)) 1996 err = -EHOSTUNREACH; 1997 goto no_route; 1998 } 1999 2000 if (res->type == RTN_BROADCAST) { 2001 if (IN_DEV_BFORWARD(in_dev)) 2002 goto make_route; 2003 goto brd_input; 2004 } 2005 2006 if (res->type == RTN_LOCAL) { 2007 err = fib_validate_source(skb, saddr, daddr, tos, 2008 0, dev, in_dev, &itag); 2009 if (err < 0) 2010 goto martian_source; 2011 goto local_input; 2012 } 2013 2014 if (!IN_DEV_FORWARD(in_dev)) { 2015 err = -EHOSTUNREACH; 2016 goto no_route; 2017 } 2018 if (res->type != RTN_UNICAST) 2019 goto martian_destination; 2020 2021 make_route: 2022 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2023 out: return err; 2024 2025 brd_input: 2026 if (skb->protocol != htons(ETH_P_IP)) 2027 goto e_inval; 2028 2029 if (!ipv4_is_zeronet(saddr)) { 2030 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2031 in_dev, &itag); 2032 if (err < 0) 2033 goto martian_source; 2034 } 2035 flags |= RTCF_BROADCAST; 2036 res->type = RTN_BROADCAST; 2037 RT_CACHE_STAT_INC(in_brd); 2038 2039 local_input: 2040 do_cache = false; 2041 if (res->fi) { 2042 if (!itag) { 2043 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 2044 if (rt_cache_valid(rth)) { 2045 skb_dst_set_noref(skb, &rth->dst); 2046 err = 0; 2047 goto out; 2048 } 2049 do_cache = true; 2050 } 2051 } 2052 2053 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2054 flags | RTCF_LOCAL, res->type, 2055 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2056 if (!rth) 2057 goto e_nobufs; 2058 2059 rth->dst.output= ip_rt_bug; 2060 #ifdef CONFIG_IP_ROUTE_CLASSID 2061 rth->dst.tclassid = itag; 2062 #endif 2063 rth->rt_is_input = 1; 2064 2065 RT_CACHE_STAT_INC(in_slow_tot); 2066 if (res->type == RTN_UNREACHABLE) { 2067 rth->dst.input= ip_error; 2068 rth->dst.error= -err; 2069 rth->rt_flags &= ~RTCF_LOCAL; 2070 } 2071 2072 if (do_cache) { 2073 struct fib_nh *nh = &FIB_RES_NH(*res); 2074 2075 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 2076 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2077 WARN_ON(rth->dst.input == lwtunnel_input); 2078 rth->dst.lwtstate->orig_input = rth->dst.input; 2079 rth->dst.input = lwtunnel_input; 2080 } 2081 2082 if (unlikely(!rt_cache_route(nh, rth))) 2083 rt_add_uncached_list(rth); 2084 } 2085 skb_dst_set(skb, &rth->dst); 2086 err = 0; 2087 goto out; 2088 2089 no_route: 2090 RT_CACHE_STAT_INC(in_no_route); 2091 res->type = RTN_UNREACHABLE; 2092 res->fi = NULL; 2093 res->table = NULL; 2094 goto local_input; 2095 2096 /* 2097 * Do not cache martian addresses: they should be logged (RFC1812) 2098 */ 2099 martian_destination: 2100 RT_CACHE_STAT_INC(in_martian_dst); 2101 #ifdef CONFIG_IP_ROUTE_VERBOSE 2102 if (IN_DEV_LOG_MARTIANS(in_dev)) 2103 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2104 &daddr, &saddr, dev->name); 2105 #endif 2106 2107 e_inval: 2108 err = -EINVAL; 2109 goto out; 2110 2111 e_nobufs: 2112 err = -ENOBUFS; 2113 goto out; 2114 2115 martian_source: 2116 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2117 goto out; 2118 } 2119 2120 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2121 u8 tos, struct net_device *dev) 2122 { 2123 struct fib_result res; 2124 int err; 2125 2126 tos &= IPTOS_RT_MASK; 2127 rcu_read_lock(); 2128 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2129 rcu_read_unlock(); 2130 2131 return err; 2132 } 2133 EXPORT_SYMBOL(ip_route_input_noref); 2134 2135 /* called with rcu_read_lock held */ 2136 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2137 u8 tos, struct net_device *dev, struct fib_result *res) 2138 { 2139 /* Multicast recognition logic is moved from route cache to here. 2140 The problem was that too many Ethernet cards have broken/missing 2141 hardware multicast filters :-( As result the host on multicasting 2142 network acquires a lot of useless route cache entries, sort of 2143 SDR messages from all the world. Now we try to get rid of them. 2144 Really, provided software IP multicast filter is organized 2145 reasonably (at least, hashed), it does not result in a slowdown 2146 comparing with route cache reject entries. 2147 Note, that multicast routers are not affected, because 2148 route cache entry is created eventually. 2149 */ 2150 if (ipv4_is_multicast(daddr)) { 2151 struct in_device *in_dev = __in_dev_get_rcu(dev); 2152 int our = 0; 2153 int err = -EINVAL; 2154 2155 if (in_dev) 2156 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2157 ip_hdr(skb)->protocol); 2158 2159 /* check l3 master if no match yet */ 2160 if ((!in_dev || !our) && netif_is_l3_slave(dev)) { 2161 struct in_device *l3_in_dev; 2162 2163 l3_in_dev = __in_dev_get_rcu(skb->dev); 2164 if (l3_in_dev) 2165 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2166 ip_hdr(skb)->protocol); 2167 } 2168 2169 if (our 2170 #ifdef CONFIG_IP_MROUTE 2171 || 2172 (!ipv4_is_local_multicast(daddr) && 2173 IN_DEV_MFORWARD(in_dev)) 2174 #endif 2175 ) { 2176 err = ip_route_input_mc(skb, daddr, saddr, 2177 tos, dev, our); 2178 } 2179 return err; 2180 } 2181 2182 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2183 } 2184 2185 /* called with rcu_read_lock() */ 2186 static struct rtable *__mkroute_output(const struct fib_result *res, 2187 const struct flowi4 *fl4, int orig_oif, 2188 struct net_device *dev_out, 2189 unsigned int flags) 2190 { 2191 struct fib_info *fi = res->fi; 2192 struct fib_nh_exception *fnhe; 2193 struct in_device *in_dev; 2194 u16 type = res->type; 2195 struct rtable *rth; 2196 bool do_cache; 2197 2198 in_dev = __in_dev_get_rcu(dev_out); 2199 if (!in_dev) 2200 return ERR_PTR(-EINVAL); 2201 2202 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2203 if (ipv4_is_loopback(fl4->saddr) && 2204 !(dev_out->flags & IFF_LOOPBACK) && 2205 !netif_is_l3_master(dev_out)) 2206 return ERR_PTR(-EINVAL); 2207 2208 if (ipv4_is_lbcast(fl4->daddr)) 2209 type = RTN_BROADCAST; 2210 else if (ipv4_is_multicast(fl4->daddr)) 2211 type = RTN_MULTICAST; 2212 else if (ipv4_is_zeronet(fl4->daddr)) 2213 return ERR_PTR(-EINVAL); 2214 2215 if (dev_out->flags & IFF_LOOPBACK) 2216 flags |= RTCF_LOCAL; 2217 2218 do_cache = true; 2219 if (type == RTN_BROADCAST) { 2220 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2221 fi = NULL; 2222 } else if (type == RTN_MULTICAST) { 2223 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2224 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2225 fl4->flowi4_proto)) 2226 flags &= ~RTCF_LOCAL; 2227 else 2228 do_cache = false; 2229 /* If multicast route do not exist use 2230 * default one, but do not gateway in this case. 2231 * Yes, it is hack. 2232 */ 2233 if (fi && res->prefixlen < 4) 2234 fi = NULL; 2235 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2236 (orig_oif != dev_out->ifindex)) { 2237 /* For local routes that require a particular output interface 2238 * we do not want to cache the result. Caching the result 2239 * causes incorrect behaviour when there are multiple source 2240 * addresses on the interface, the end result being that if the 2241 * intended recipient is waiting on that interface for the 2242 * packet he won't receive it because it will be delivered on 2243 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2244 * be set to the loopback interface as well. 2245 */ 2246 do_cache = false; 2247 } 2248 2249 fnhe = NULL; 2250 do_cache &= fi != NULL; 2251 if (fi) { 2252 struct rtable __rcu **prth; 2253 struct fib_nh *nh = &FIB_RES_NH(*res); 2254 2255 fnhe = find_exception(nh, fl4->daddr); 2256 if (!do_cache) 2257 goto add; 2258 if (fnhe) { 2259 prth = &fnhe->fnhe_rth_output; 2260 } else { 2261 if (unlikely(fl4->flowi4_flags & 2262 FLOWI_FLAG_KNOWN_NH && 2263 !(nh->nh_gw && 2264 nh->nh_scope == RT_SCOPE_LINK))) { 2265 do_cache = false; 2266 goto add; 2267 } 2268 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 2269 } 2270 rth = rcu_dereference(*prth); 2271 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2272 return rth; 2273 } 2274 2275 add: 2276 rth = rt_dst_alloc(dev_out, flags, type, 2277 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2278 IN_DEV_CONF_GET(in_dev, NOXFRM), 2279 do_cache); 2280 if (!rth) 2281 return ERR_PTR(-ENOBUFS); 2282 2283 rth->rt_iif = orig_oif; 2284 2285 RT_CACHE_STAT_INC(out_slow_tot); 2286 2287 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2288 if (flags & RTCF_LOCAL && 2289 !(dev_out->flags & IFF_LOOPBACK)) { 2290 rth->dst.output = ip_mc_output; 2291 RT_CACHE_STAT_INC(out_slow_mc); 2292 } 2293 #ifdef CONFIG_IP_MROUTE 2294 if (type == RTN_MULTICAST) { 2295 if (IN_DEV_MFORWARD(in_dev) && 2296 !ipv4_is_local_multicast(fl4->daddr)) { 2297 rth->dst.input = ip_mr_input; 2298 rth->dst.output = ip_mc_output; 2299 } 2300 } 2301 #endif 2302 } 2303 2304 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2305 lwtunnel_set_redirect(&rth->dst); 2306 2307 return rth; 2308 } 2309 2310 /* 2311 * Major route resolver routine. 2312 */ 2313 2314 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2315 const struct sk_buff *skb) 2316 { 2317 __u8 tos = RT_FL_TOS(fl4); 2318 struct fib_result res = { 2319 .type = RTN_UNSPEC, 2320 .fi = NULL, 2321 .table = NULL, 2322 .tclassid = 0, 2323 }; 2324 struct rtable *rth; 2325 2326 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2327 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2328 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2329 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2330 2331 rcu_read_lock(); 2332 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2333 rcu_read_unlock(); 2334 2335 return rth; 2336 } 2337 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2338 2339 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2340 struct fib_result *res, 2341 const struct sk_buff *skb) 2342 { 2343 struct net_device *dev_out = NULL; 2344 int orig_oif = fl4->flowi4_oif; 2345 unsigned int flags = 0; 2346 struct rtable *rth; 2347 int err = -ENETUNREACH; 2348 2349 if (fl4->saddr) { 2350 rth = ERR_PTR(-EINVAL); 2351 if (ipv4_is_multicast(fl4->saddr) || 2352 ipv4_is_lbcast(fl4->saddr) || 2353 ipv4_is_zeronet(fl4->saddr)) 2354 goto out; 2355 2356 /* I removed check for oif == dev_out->oif here. 2357 It was wrong for two reasons: 2358 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2359 is assigned to multiple interfaces. 2360 2. Moreover, we are allowed to send packets with saddr 2361 of another iface. --ANK 2362 */ 2363 2364 if (fl4->flowi4_oif == 0 && 2365 (ipv4_is_multicast(fl4->daddr) || 2366 ipv4_is_lbcast(fl4->daddr))) { 2367 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2368 dev_out = __ip_dev_find(net, fl4->saddr, false); 2369 if (!dev_out) 2370 goto out; 2371 2372 /* Special hack: user can direct multicasts 2373 and limited broadcast via necessary interface 2374 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2375 This hack is not just for fun, it allows 2376 vic,vat and friends to work. 2377 They bind socket to loopback, set ttl to zero 2378 and expect that it will work. 2379 From the viewpoint of routing cache they are broken, 2380 because we are not allowed to build multicast path 2381 with loopback source addr (look, routing cache 2382 cannot know, that ttl is zero, so that packet 2383 will not leave this host and route is valid). 2384 Luckily, this hack is good workaround. 2385 */ 2386 2387 fl4->flowi4_oif = dev_out->ifindex; 2388 goto make_route; 2389 } 2390 2391 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2392 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2393 if (!__ip_dev_find(net, fl4->saddr, false)) 2394 goto out; 2395 } 2396 } 2397 2398 2399 if (fl4->flowi4_oif) { 2400 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2401 rth = ERR_PTR(-ENODEV); 2402 if (!dev_out) 2403 goto out; 2404 2405 /* RACE: Check return value of inet_select_addr instead. */ 2406 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2407 rth = ERR_PTR(-ENETUNREACH); 2408 goto out; 2409 } 2410 if (ipv4_is_local_multicast(fl4->daddr) || 2411 ipv4_is_lbcast(fl4->daddr) || 2412 fl4->flowi4_proto == IPPROTO_IGMP) { 2413 if (!fl4->saddr) 2414 fl4->saddr = inet_select_addr(dev_out, 0, 2415 RT_SCOPE_LINK); 2416 goto make_route; 2417 } 2418 if (!fl4->saddr) { 2419 if (ipv4_is_multicast(fl4->daddr)) 2420 fl4->saddr = inet_select_addr(dev_out, 0, 2421 fl4->flowi4_scope); 2422 else if (!fl4->daddr) 2423 fl4->saddr = inet_select_addr(dev_out, 0, 2424 RT_SCOPE_HOST); 2425 } 2426 } 2427 2428 if (!fl4->daddr) { 2429 fl4->daddr = fl4->saddr; 2430 if (!fl4->daddr) 2431 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2432 dev_out = net->loopback_dev; 2433 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2434 res->type = RTN_LOCAL; 2435 flags |= RTCF_LOCAL; 2436 goto make_route; 2437 } 2438 2439 err = fib_lookup(net, fl4, res, 0); 2440 if (err) { 2441 res->fi = NULL; 2442 res->table = NULL; 2443 if (fl4->flowi4_oif && 2444 (ipv4_is_multicast(fl4->daddr) || 2445 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2446 /* Apparently, routing tables are wrong. Assume, 2447 that the destination is on link. 2448 2449 WHY? DW. 2450 Because we are allowed to send to iface 2451 even if it has NO routes and NO assigned 2452 addresses. When oif is specified, routing 2453 tables are looked up with only one purpose: 2454 to catch if destination is gatewayed, rather than 2455 direct. Moreover, if MSG_DONTROUTE is set, 2456 we send packet, ignoring both routing tables 2457 and ifaddr state. --ANK 2458 2459 2460 We could make it even if oif is unknown, 2461 likely IPv6, but we do not. 2462 */ 2463 2464 if (fl4->saddr == 0) 2465 fl4->saddr = inet_select_addr(dev_out, 0, 2466 RT_SCOPE_LINK); 2467 res->type = RTN_UNICAST; 2468 goto make_route; 2469 } 2470 rth = ERR_PTR(err); 2471 goto out; 2472 } 2473 2474 if (res->type == RTN_LOCAL) { 2475 if (!fl4->saddr) { 2476 if (res->fi->fib_prefsrc) 2477 fl4->saddr = res->fi->fib_prefsrc; 2478 else 2479 fl4->saddr = fl4->daddr; 2480 } 2481 2482 /* L3 master device is the loopback for that domain */ 2483 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2484 net->loopback_dev; 2485 2486 /* make sure orig_oif points to fib result device even 2487 * though packet rx/tx happens over loopback or l3mdev 2488 */ 2489 orig_oif = FIB_RES_OIF(*res); 2490 2491 fl4->flowi4_oif = dev_out->ifindex; 2492 flags |= RTCF_LOCAL; 2493 goto make_route; 2494 } 2495 2496 fib_select_path(net, res, fl4, skb); 2497 2498 dev_out = FIB_RES_DEV(*res); 2499 fl4->flowi4_oif = dev_out->ifindex; 2500 2501 2502 make_route: 2503 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2504 2505 out: 2506 return rth; 2507 } 2508 2509 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2510 { 2511 return NULL; 2512 } 2513 2514 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2515 { 2516 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2517 2518 return mtu ? : dst->dev->mtu; 2519 } 2520 2521 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2522 struct sk_buff *skb, u32 mtu) 2523 { 2524 } 2525 2526 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2527 struct sk_buff *skb) 2528 { 2529 } 2530 2531 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2532 unsigned long old) 2533 { 2534 return NULL; 2535 } 2536 2537 static struct dst_ops ipv4_dst_blackhole_ops = { 2538 .family = AF_INET, 2539 .check = ipv4_blackhole_dst_check, 2540 .mtu = ipv4_blackhole_mtu, 2541 .default_advmss = ipv4_default_advmss, 2542 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2543 .redirect = ipv4_rt_blackhole_redirect, 2544 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2545 .neigh_lookup = ipv4_neigh_lookup, 2546 }; 2547 2548 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2549 { 2550 struct rtable *ort = (struct rtable *) dst_orig; 2551 struct rtable *rt; 2552 2553 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2554 if (rt) { 2555 struct dst_entry *new = &rt->dst; 2556 2557 new->__use = 1; 2558 new->input = dst_discard; 2559 new->output = dst_discard_out; 2560 2561 new->dev = net->loopback_dev; 2562 if (new->dev) 2563 dev_hold(new->dev); 2564 2565 rt->rt_is_input = ort->rt_is_input; 2566 rt->rt_iif = ort->rt_iif; 2567 rt->rt_pmtu = ort->rt_pmtu; 2568 rt->rt_mtu_locked = ort->rt_mtu_locked; 2569 2570 rt->rt_genid = rt_genid_ipv4(net); 2571 rt->rt_flags = ort->rt_flags; 2572 rt->rt_type = ort->rt_type; 2573 rt->rt_gateway = ort->rt_gateway; 2574 rt->rt_uses_gateway = ort->rt_uses_gateway; 2575 2576 INIT_LIST_HEAD(&rt->rt_uncached); 2577 } 2578 2579 dst_release(dst_orig); 2580 2581 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2582 } 2583 2584 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2585 const struct sock *sk) 2586 { 2587 struct rtable *rt = __ip_route_output_key(net, flp4); 2588 2589 if (IS_ERR(rt)) 2590 return rt; 2591 2592 if (flp4->flowi4_proto) 2593 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2594 flowi4_to_flowi(flp4), 2595 sk, 0); 2596 2597 return rt; 2598 } 2599 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2600 2601 /* called with rcu_read_lock held */ 2602 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2603 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2604 struct sk_buff *skb, u32 portid, u32 seq) 2605 { 2606 struct rtmsg *r; 2607 struct nlmsghdr *nlh; 2608 unsigned long expires = 0; 2609 u32 error; 2610 u32 metrics[RTAX_MAX]; 2611 2612 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2613 if (!nlh) 2614 return -EMSGSIZE; 2615 2616 r = nlmsg_data(nlh); 2617 r->rtm_family = AF_INET; 2618 r->rtm_dst_len = 32; 2619 r->rtm_src_len = 0; 2620 r->rtm_tos = fl4->flowi4_tos; 2621 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2622 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2623 goto nla_put_failure; 2624 r->rtm_type = rt->rt_type; 2625 r->rtm_scope = RT_SCOPE_UNIVERSE; 2626 r->rtm_protocol = RTPROT_UNSPEC; 2627 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2628 if (rt->rt_flags & RTCF_NOTIFY) 2629 r->rtm_flags |= RTM_F_NOTIFY; 2630 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2631 r->rtm_flags |= RTCF_DOREDIRECT; 2632 2633 if (nla_put_in_addr(skb, RTA_DST, dst)) 2634 goto nla_put_failure; 2635 if (src) { 2636 r->rtm_src_len = 32; 2637 if (nla_put_in_addr(skb, RTA_SRC, src)) 2638 goto nla_put_failure; 2639 } 2640 if (rt->dst.dev && 2641 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2642 goto nla_put_failure; 2643 #ifdef CONFIG_IP_ROUTE_CLASSID 2644 if (rt->dst.tclassid && 2645 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2646 goto nla_put_failure; 2647 #endif 2648 if (!rt_is_input_route(rt) && 2649 fl4->saddr != src) { 2650 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2651 goto nla_put_failure; 2652 } 2653 if (rt->rt_uses_gateway && 2654 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2655 goto nla_put_failure; 2656 2657 expires = rt->dst.expires; 2658 if (expires) { 2659 unsigned long now = jiffies; 2660 2661 if (time_before(now, expires)) 2662 expires -= now; 2663 else 2664 expires = 0; 2665 } 2666 2667 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2668 if (rt->rt_pmtu && expires) 2669 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2670 if (rt->rt_mtu_locked && expires) 2671 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2672 if (rtnetlink_put_metrics(skb, metrics) < 0) 2673 goto nla_put_failure; 2674 2675 if (fl4->flowi4_mark && 2676 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2677 goto nla_put_failure; 2678 2679 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2680 nla_put_u32(skb, RTA_UID, 2681 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2682 goto nla_put_failure; 2683 2684 error = rt->dst.error; 2685 2686 if (rt_is_input_route(rt)) { 2687 #ifdef CONFIG_IP_MROUTE 2688 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2689 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2690 int err = ipmr_get_route(net, skb, 2691 fl4->saddr, fl4->daddr, 2692 r, portid); 2693 2694 if (err <= 0) { 2695 if (err == 0) 2696 return 0; 2697 goto nla_put_failure; 2698 } 2699 } else 2700 #endif 2701 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2702 goto nla_put_failure; 2703 } 2704 2705 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2706 goto nla_put_failure; 2707 2708 nlmsg_end(skb, nlh); 2709 return 0; 2710 2711 nla_put_failure: 2712 nlmsg_cancel(skb, nlh); 2713 return -EMSGSIZE; 2714 } 2715 2716 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2717 u8 ip_proto, __be16 sport, 2718 __be16 dport) 2719 { 2720 struct sk_buff *skb; 2721 struct iphdr *iph; 2722 2723 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2724 if (!skb) 2725 return NULL; 2726 2727 /* Reserve room for dummy headers, this skb can pass 2728 * through good chunk of routing engine. 2729 */ 2730 skb_reset_mac_header(skb); 2731 skb_reset_network_header(skb); 2732 skb->protocol = htons(ETH_P_IP); 2733 iph = skb_put(skb, sizeof(struct iphdr)); 2734 iph->protocol = ip_proto; 2735 iph->saddr = src; 2736 iph->daddr = dst; 2737 iph->version = 0x4; 2738 iph->frag_off = 0; 2739 iph->ihl = 0x5; 2740 skb_set_transport_header(skb, skb->len); 2741 2742 switch (iph->protocol) { 2743 case IPPROTO_UDP: { 2744 struct udphdr *udph; 2745 2746 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2747 udph->source = sport; 2748 udph->dest = dport; 2749 udph->len = sizeof(struct udphdr); 2750 udph->check = 0; 2751 break; 2752 } 2753 case IPPROTO_TCP: { 2754 struct tcphdr *tcph; 2755 2756 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2757 tcph->source = sport; 2758 tcph->dest = dport; 2759 tcph->doff = sizeof(struct tcphdr) / 4; 2760 tcph->rst = 1; 2761 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2762 src, dst, 0); 2763 break; 2764 } 2765 case IPPROTO_ICMP: { 2766 struct icmphdr *icmph; 2767 2768 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2769 icmph->type = ICMP_ECHO; 2770 icmph->code = 0; 2771 } 2772 } 2773 2774 return skb; 2775 } 2776 2777 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2778 struct netlink_ext_ack *extack) 2779 { 2780 struct net *net = sock_net(in_skb->sk); 2781 struct nlattr *tb[RTA_MAX+1]; 2782 u32 table_id = RT_TABLE_MAIN; 2783 __be16 sport = 0, dport = 0; 2784 struct fib_result res = {}; 2785 u8 ip_proto = IPPROTO_UDP; 2786 struct rtable *rt = NULL; 2787 struct sk_buff *skb; 2788 struct rtmsg *rtm; 2789 struct flowi4 fl4; 2790 __be32 dst = 0; 2791 __be32 src = 0; 2792 kuid_t uid; 2793 u32 iif; 2794 int err; 2795 int mark; 2796 2797 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy, 2798 extack); 2799 if (err < 0) 2800 return err; 2801 2802 rtm = nlmsg_data(nlh); 2803 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2804 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2805 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2806 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2807 if (tb[RTA_UID]) 2808 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2809 else 2810 uid = (iif ? INVALID_UID : current_uid()); 2811 2812 if (tb[RTA_IP_PROTO]) { 2813 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2814 &ip_proto, extack); 2815 if (err) 2816 return err; 2817 } 2818 2819 if (tb[RTA_SPORT]) 2820 sport = nla_get_be16(tb[RTA_SPORT]); 2821 2822 if (tb[RTA_DPORT]) 2823 dport = nla_get_be16(tb[RTA_DPORT]); 2824 2825 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2826 if (!skb) 2827 return -ENOBUFS; 2828 2829 memset(&fl4, 0, sizeof(fl4)); 2830 fl4.daddr = dst; 2831 fl4.saddr = src; 2832 fl4.flowi4_tos = rtm->rtm_tos; 2833 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2834 fl4.flowi4_mark = mark; 2835 fl4.flowi4_uid = uid; 2836 if (sport) 2837 fl4.fl4_sport = sport; 2838 if (dport) 2839 fl4.fl4_dport = dport; 2840 fl4.flowi4_proto = ip_proto; 2841 2842 rcu_read_lock(); 2843 2844 if (iif) { 2845 struct net_device *dev; 2846 2847 dev = dev_get_by_index_rcu(net, iif); 2848 if (!dev) { 2849 err = -ENODEV; 2850 goto errout_rcu; 2851 } 2852 2853 fl4.flowi4_iif = iif; /* for rt_fill_info */ 2854 skb->dev = dev; 2855 skb->mark = mark; 2856 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 2857 dev, &res); 2858 2859 rt = skb_rtable(skb); 2860 if (err == 0 && rt->dst.error) 2861 err = -rt->dst.error; 2862 } else { 2863 fl4.flowi4_iif = LOOPBACK_IFINDEX; 2864 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 2865 err = 0; 2866 if (IS_ERR(rt)) 2867 err = PTR_ERR(rt); 2868 else 2869 skb_dst_set(skb, &rt->dst); 2870 } 2871 2872 if (err) 2873 goto errout_rcu; 2874 2875 if (rtm->rtm_flags & RTM_F_NOTIFY) 2876 rt->rt_flags |= RTCF_NOTIFY; 2877 2878 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 2879 table_id = res.table ? res.table->tb_id : 0; 2880 2881 /* reset skb for netlink reply msg */ 2882 skb_trim(skb, 0); 2883 skb_reset_network_header(skb); 2884 skb_reset_transport_header(skb); 2885 skb_reset_mac_header(skb); 2886 2887 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2888 if (!res.fi) { 2889 err = fib_props[res.type].error; 2890 if (!err) 2891 err = -EHOSTUNREACH; 2892 goto errout_rcu; 2893 } 2894 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 2895 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 2896 rt->rt_type, res.prefix, res.prefixlen, 2897 fl4.flowi4_tos, res.fi, 0); 2898 } else { 2899 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 2900 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 2901 } 2902 if (err < 0) 2903 goto errout_rcu; 2904 2905 rcu_read_unlock(); 2906 2907 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2908 2909 errout_free: 2910 return err; 2911 errout_rcu: 2912 rcu_read_unlock(); 2913 kfree_skb(skb); 2914 goto errout_free; 2915 } 2916 2917 void ip_rt_multicast_event(struct in_device *in_dev) 2918 { 2919 rt_cache_flush(dev_net(in_dev->dev)); 2920 } 2921 2922 #ifdef CONFIG_SYSCTL 2923 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2924 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2925 static int ip_rt_gc_elasticity __read_mostly = 8; 2926 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 2927 2928 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2929 void __user *buffer, 2930 size_t *lenp, loff_t *ppos) 2931 { 2932 struct net *net = (struct net *)__ctl->extra1; 2933 2934 if (write) { 2935 rt_cache_flush(net); 2936 fnhe_genid_bump(net); 2937 return 0; 2938 } 2939 2940 return -EINVAL; 2941 } 2942 2943 static struct ctl_table ipv4_route_table[] = { 2944 { 2945 .procname = "gc_thresh", 2946 .data = &ipv4_dst_ops.gc_thresh, 2947 .maxlen = sizeof(int), 2948 .mode = 0644, 2949 .proc_handler = proc_dointvec, 2950 }, 2951 { 2952 .procname = "max_size", 2953 .data = &ip_rt_max_size, 2954 .maxlen = sizeof(int), 2955 .mode = 0644, 2956 .proc_handler = proc_dointvec, 2957 }, 2958 { 2959 /* Deprecated. Use gc_min_interval_ms */ 2960 2961 .procname = "gc_min_interval", 2962 .data = &ip_rt_gc_min_interval, 2963 .maxlen = sizeof(int), 2964 .mode = 0644, 2965 .proc_handler = proc_dointvec_jiffies, 2966 }, 2967 { 2968 .procname = "gc_min_interval_ms", 2969 .data = &ip_rt_gc_min_interval, 2970 .maxlen = sizeof(int), 2971 .mode = 0644, 2972 .proc_handler = proc_dointvec_ms_jiffies, 2973 }, 2974 { 2975 .procname = "gc_timeout", 2976 .data = &ip_rt_gc_timeout, 2977 .maxlen = sizeof(int), 2978 .mode = 0644, 2979 .proc_handler = proc_dointvec_jiffies, 2980 }, 2981 { 2982 .procname = "gc_interval", 2983 .data = &ip_rt_gc_interval, 2984 .maxlen = sizeof(int), 2985 .mode = 0644, 2986 .proc_handler = proc_dointvec_jiffies, 2987 }, 2988 { 2989 .procname = "redirect_load", 2990 .data = &ip_rt_redirect_load, 2991 .maxlen = sizeof(int), 2992 .mode = 0644, 2993 .proc_handler = proc_dointvec, 2994 }, 2995 { 2996 .procname = "redirect_number", 2997 .data = &ip_rt_redirect_number, 2998 .maxlen = sizeof(int), 2999 .mode = 0644, 3000 .proc_handler = proc_dointvec, 3001 }, 3002 { 3003 .procname = "redirect_silence", 3004 .data = &ip_rt_redirect_silence, 3005 .maxlen = sizeof(int), 3006 .mode = 0644, 3007 .proc_handler = proc_dointvec, 3008 }, 3009 { 3010 .procname = "error_cost", 3011 .data = &ip_rt_error_cost, 3012 .maxlen = sizeof(int), 3013 .mode = 0644, 3014 .proc_handler = proc_dointvec, 3015 }, 3016 { 3017 .procname = "error_burst", 3018 .data = &ip_rt_error_burst, 3019 .maxlen = sizeof(int), 3020 .mode = 0644, 3021 .proc_handler = proc_dointvec, 3022 }, 3023 { 3024 .procname = "gc_elasticity", 3025 .data = &ip_rt_gc_elasticity, 3026 .maxlen = sizeof(int), 3027 .mode = 0644, 3028 .proc_handler = proc_dointvec, 3029 }, 3030 { 3031 .procname = "mtu_expires", 3032 .data = &ip_rt_mtu_expires, 3033 .maxlen = sizeof(int), 3034 .mode = 0644, 3035 .proc_handler = proc_dointvec_jiffies, 3036 }, 3037 { 3038 .procname = "min_pmtu", 3039 .data = &ip_rt_min_pmtu, 3040 .maxlen = sizeof(int), 3041 .mode = 0644, 3042 .proc_handler = proc_dointvec_minmax, 3043 .extra1 = &ip_min_valid_pmtu, 3044 }, 3045 { 3046 .procname = "min_adv_mss", 3047 .data = &ip_rt_min_advmss, 3048 .maxlen = sizeof(int), 3049 .mode = 0644, 3050 .proc_handler = proc_dointvec, 3051 }, 3052 { } 3053 }; 3054 3055 static struct ctl_table ipv4_route_flush_table[] = { 3056 { 3057 .procname = "flush", 3058 .maxlen = sizeof(int), 3059 .mode = 0200, 3060 .proc_handler = ipv4_sysctl_rtcache_flush, 3061 }, 3062 { }, 3063 }; 3064 3065 static __net_init int sysctl_route_net_init(struct net *net) 3066 { 3067 struct ctl_table *tbl; 3068 3069 tbl = ipv4_route_flush_table; 3070 if (!net_eq(net, &init_net)) { 3071 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3072 if (!tbl) 3073 goto err_dup; 3074 3075 /* Don't export sysctls to unprivileged users */ 3076 if (net->user_ns != &init_user_ns) 3077 tbl[0].procname = NULL; 3078 } 3079 tbl[0].extra1 = net; 3080 3081 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3082 if (!net->ipv4.route_hdr) 3083 goto err_reg; 3084 return 0; 3085 3086 err_reg: 3087 if (tbl != ipv4_route_flush_table) 3088 kfree(tbl); 3089 err_dup: 3090 return -ENOMEM; 3091 } 3092 3093 static __net_exit void sysctl_route_net_exit(struct net *net) 3094 { 3095 struct ctl_table *tbl; 3096 3097 tbl = net->ipv4.route_hdr->ctl_table_arg; 3098 unregister_net_sysctl_table(net->ipv4.route_hdr); 3099 BUG_ON(tbl == ipv4_route_flush_table); 3100 kfree(tbl); 3101 } 3102 3103 static __net_initdata struct pernet_operations sysctl_route_ops = { 3104 .init = sysctl_route_net_init, 3105 .exit = sysctl_route_net_exit, 3106 }; 3107 #endif 3108 3109 static __net_init int rt_genid_init(struct net *net) 3110 { 3111 atomic_set(&net->ipv4.rt_genid, 0); 3112 atomic_set(&net->fnhe_genid, 0); 3113 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3114 return 0; 3115 } 3116 3117 static __net_initdata struct pernet_operations rt_genid_ops = { 3118 .init = rt_genid_init, 3119 }; 3120 3121 static int __net_init ipv4_inetpeer_init(struct net *net) 3122 { 3123 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3124 3125 if (!bp) 3126 return -ENOMEM; 3127 inet_peer_base_init(bp); 3128 net->ipv4.peers = bp; 3129 return 0; 3130 } 3131 3132 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3133 { 3134 struct inet_peer_base *bp = net->ipv4.peers; 3135 3136 net->ipv4.peers = NULL; 3137 inetpeer_invalidate_tree(bp); 3138 kfree(bp); 3139 } 3140 3141 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3142 .init = ipv4_inetpeer_init, 3143 .exit = ipv4_inetpeer_exit, 3144 }; 3145 3146 #ifdef CONFIG_IP_ROUTE_CLASSID 3147 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3148 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3149 3150 int __init ip_rt_init(void) 3151 { 3152 int cpu; 3153 3154 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3155 GFP_KERNEL); 3156 if (!ip_idents) 3157 panic("IP: failed to allocate ip_idents\n"); 3158 3159 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3160 3161 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3162 if (!ip_tstamps) 3163 panic("IP: failed to allocate ip_tstamps\n"); 3164 3165 for_each_possible_cpu(cpu) { 3166 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3167 3168 INIT_LIST_HEAD(&ul->head); 3169 spin_lock_init(&ul->lock); 3170 } 3171 #ifdef CONFIG_IP_ROUTE_CLASSID 3172 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3173 if (!ip_rt_acct) 3174 panic("IP: failed to allocate ip_rt_acct\n"); 3175 #endif 3176 3177 ipv4_dst_ops.kmem_cachep = 3178 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3179 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3180 3181 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3182 3183 if (dst_entries_init(&ipv4_dst_ops) < 0) 3184 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3185 3186 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3187 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3188 3189 ipv4_dst_ops.gc_thresh = ~0; 3190 ip_rt_max_size = INT_MAX; 3191 3192 devinet_init(); 3193 ip_fib_init(); 3194 3195 if (ip_rt_proc_init()) 3196 pr_err("Unable to create route proc files\n"); 3197 #ifdef CONFIG_XFRM 3198 xfrm_init(); 3199 xfrm4_init(); 3200 #endif 3201 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3202 RTNL_FLAG_DOIT_UNLOCKED); 3203 3204 #ifdef CONFIG_SYSCTL 3205 register_pernet_subsys(&sysctl_route_ops); 3206 #endif 3207 register_pernet_subsys(&rt_genid_ops); 3208 register_pernet_subsys(&ipv4_inetpeer_ops); 3209 return 0; 3210 } 3211 3212 #ifdef CONFIG_SYSCTL 3213 /* 3214 * We really need to sanitize the damn ipv4 init order, then all 3215 * this nonsense will go away. 3216 */ 3217 void __init ip_static_sysctl_init(void) 3218 { 3219 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3220 } 3221 #endif 3222