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 <asm/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/net_namespace.h> 95 #include <net/protocol.h> 96 #include <net/ip.h> 97 #include <net/route.h> 98 #include <net/inetpeer.h> 99 #include <net/sock.h> 100 #include <net/ip_fib.h> 101 #include <net/arp.h> 102 #include <net/tcp.h> 103 #include <net/icmp.h> 104 #include <net/xfrm.h> 105 #include <net/netevent.h> 106 #include <net/rtnetlink.h> 107 #ifdef CONFIG_SYSCTL 108 #include <linux/sysctl.h> 109 #include <linux/kmemleak.h> 110 #endif 111 #include <net/secure_seq.h> 112 113 #define RT_FL_TOS(oldflp4) \ 114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 115 116 #define RT_GC_TIMEOUT (300*HZ) 117 118 static int ip_rt_max_size; 119 static int ip_rt_redirect_number __read_mostly = 9; 120 static int ip_rt_redirect_load __read_mostly = HZ / 50; 121 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 122 static int ip_rt_error_cost __read_mostly = HZ; 123 static int ip_rt_error_burst __read_mostly = 5 * HZ; 124 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 125 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 126 static int ip_rt_min_advmss __read_mostly = 256; 127 128 /* 129 * Interface to generic destination cache. 130 */ 131 132 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 133 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 134 static unsigned int ipv4_mtu(const struct dst_entry *dst); 135 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 136 static void ipv4_link_failure(struct sk_buff *skb); 137 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 138 struct sk_buff *skb, u32 mtu); 139 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 140 struct sk_buff *skb); 141 static void ipv4_dst_destroy(struct dst_entry *dst); 142 143 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 144 { 145 WARN_ON(1); 146 return NULL; 147 } 148 149 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 150 struct sk_buff *skb, 151 const void *daddr); 152 153 static struct dst_ops ipv4_dst_ops = { 154 .family = AF_INET, 155 .check = ipv4_dst_check, 156 .default_advmss = ipv4_default_advmss, 157 .mtu = ipv4_mtu, 158 .cow_metrics = ipv4_cow_metrics, 159 .destroy = ipv4_dst_destroy, 160 .negative_advice = ipv4_negative_advice, 161 .link_failure = ipv4_link_failure, 162 .update_pmtu = ip_rt_update_pmtu, 163 .redirect = ip_do_redirect, 164 .local_out = __ip_local_out, 165 .neigh_lookup = ipv4_neigh_lookup, 166 }; 167 168 #define ECN_OR_COST(class) TC_PRIO_##class 169 170 const __u8 ip_tos2prio[16] = { 171 TC_PRIO_BESTEFFORT, 172 ECN_OR_COST(BESTEFFORT), 173 TC_PRIO_BESTEFFORT, 174 ECN_OR_COST(BESTEFFORT), 175 TC_PRIO_BULK, 176 ECN_OR_COST(BULK), 177 TC_PRIO_BULK, 178 ECN_OR_COST(BULK), 179 TC_PRIO_INTERACTIVE, 180 ECN_OR_COST(INTERACTIVE), 181 TC_PRIO_INTERACTIVE, 182 ECN_OR_COST(INTERACTIVE), 183 TC_PRIO_INTERACTIVE_BULK, 184 ECN_OR_COST(INTERACTIVE_BULK), 185 TC_PRIO_INTERACTIVE_BULK, 186 ECN_OR_COST(INTERACTIVE_BULK) 187 }; 188 EXPORT_SYMBOL(ip_tos2prio); 189 190 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 191 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 192 193 #ifdef CONFIG_PROC_FS 194 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 195 { 196 if (*pos) 197 return NULL; 198 return SEQ_START_TOKEN; 199 } 200 201 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 202 { 203 ++*pos; 204 return NULL; 205 } 206 207 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 208 { 209 } 210 211 static int rt_cache_seq_show(struct seq_file *seq, void *v) 212 { 213 if (v == SEQ_START_TOKEN) 214 seq_printf(seq, "%-127s\n", 215 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 216 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 217 "HHUptod\tSpecDst"); 218 return 0; 219 } 220 221 static const struct seq_operations rt_cache_seq_ops = { 222 .start = rt_cache_seq_start, 223 .next = rt_cache_seq_next, 224 .stop = rt_cache_seq_stop, 225 .show = rt_cache_seq_show, 226 }; 227 228 static int rt_cache_seq_open(struct inode *inode, struct file *file) 229 { 230 return seq_open(file, &rt_cache_seq_ops); 231 } 232 233 static const struct file_operations rt_cache_seq_fops = { 234 .owner = THIS_MODULE, 235 .open = rt_cache_seq_open, 236 .read = seq_read, 237 .llseek = seq_lseek, 238 .release = seq_release, 239 }; 240 241 242 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 243 { 244 int cpu; 245 246 if (*pos == 0) 247 return SEQ_START_TOKEN; 248 249 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 250 if (!cpu_possible(cpu)) 251 continue; 252 *pos = cpu+1; 253 return &per_cpu(rt_cache_stat, cpu); 254 } 255 return NULL; 256 } 257 258 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 259 { 260 int cpu; 261 262 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 263 if (!cpu_possible(cpu)) 264 continue; 265 *pos = cpu+1; 266 return &per_cpu(rt_cache_stat, cpu); 267 } 268 return NULL; 269 270 } 271 272 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 273 { 274 275 } 276 277 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 278 { 279 struct rt_cache_stat *st = v; 280 281 if (v == SEQ_START_TOKEN) { 282 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"); 283 return 0; 284 } 285 286 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 287 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 288 dst_entries_get_slow(&ipv4_dst_ops), 289 0, /* st->in_hit */ 290 st->in_slow_tot, 291 st->in_slow_mc, 292 st->in_no_route, 293 st->in_brd, 294 st->in_martian_dst, 295 st->in_martian_src, 296 297 0, /* st->out_hit */ 298 st->out_slow_tot, 299 st->out_slow_mc, 300 301 0, /* st->gc_total */ 302 0, /* st->gc_ignored */ 303 0, /* st->gc_goal_miss */ 304 0, /* st->gc_dst_overflow */ 305 0, /* st->in_hlist_search */ 306 0 /* st->out_hlist_search */ 307 ); 308 return 0; 309 } 310 311 static const struct seq_operations rt_cpu_seq_ops = { 312 .start = rt_cpu_seq_start, 313 .next = rt_cpu_seq_next, 314 .stop = rt_cpu_seq_stop, 315 .show = rt_cpu_seq_show, 316 }; 317 318 319 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 320 { 321 return seq_open(file, &rt_cpu_seq_ops); 322 } 323 324 static const struct file_operations rt_cpu_seq_fops = { 325 .owner = THIS_MODULE, 326 .open = rt_cpu_seq_open, 327 .read = seq_read, 328 .llseek = seq_lseek, 329 .release = seq_release, 330 }; 331 332 #ifdef CONFIG_IP_ROUTE_CLASSID 333 static int rt_acct_proc_show(struct seq_file *m, void *v) 334 { 335 struct ip_rt_acct *dst, *src; 336 unsigned int i, j; 337 338 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 339 if (!dst) 340 return -ENOMEM; 341 342 for_each_possible_cpu(i) { 343 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 344 for (j = 0; j < 256; j++) { 345 dst[j].o_bytes += src[j].o_bytes; 346 dst[j].o_packets += src[j].o_packets; 347 dst[j].i_bytes += src[j].i_bytes; 348 dst[j].i_packets += src[j].i_packets; 349 } 350 } 351 352 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 353 kfree(dst); 354 return 0; 355 } 356 357 static int rt_acct_proc_open(struct inode *inode, struct file *file) 358 { 359 return single_open(file, rt_acct_proc_show, NULL); 360 } 361 362 static const struct file_operations rt_acct_proc_fops = { 363 .owner = THIS_MODULE, 364 .open = rt_acct_proc_open, 365 .read = seq_read, 366 .llseek = seq_lseek, 367 .release = single_release, 368 }; 369 #endif 370 371 static int __net_init ip_rt_do_proc_init(struct net *net) 372 { 373 struct proc_dir_entry *pde; 374 375 pde = proc_create("rt_cache", S_IRUGO, net->proc_net, 376 &rt_cache_seq_fops); 377 if (!pde) 378 goto err1; 379 380 pde = proc_create("rt_cache", S_IRUGO, 381 net->proc_net_stat, &rt_cpu_seq_fops); 382 if (!pde) 383 goto err2; 384 385 #ifdef CONFIG_IP_ROUTE_CLASSID 386 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 387 if (!pde) 388 goto err3; 389 #endif 390 return 0; 391 392 #ifdef CONFIG_IP_ROUTE_CLASSID 393 err3: 394 remove_proc_entry("rt_cache", net->proc_net_stat); 395 #endif 396 err2: 397 remove_proc_entry("rt_cache", net->proc_net); 398 err1: 399 return -ENOMEM; 400 } 401 402 static void __net_exit ip_rt_do_proc_exit(struct net *net) 403 { 404 remove_proc_entry("rt_cache", net->proc_net_stat); 405 remove_proc_entry("rt_cache", net->proc_net); 406 #ifdef CONFIG_IP_ROUTE_CLASSID 407 remove_proc_entry("rt_acct", net->proc_net); 408 #endif 409 } 410 411 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 412 .init = ip_rt_do_proc_init, 413 .exit = ip_rt_do_proc_exit, 414 }; 415 416 static int __init ip_rt_proc_init(void) 417 { 418 return register_pernet_subsys(&ip_rt_proc_ops); 419 } 420 421 #else 422 static inline int ip_rt_proc_init(void) 423 { 424 return 0; 425 } 426 #endif /* CONFIG_PROC_FS */ 427 428 static inline bool rt_is_expired(const struct rtable *rth) 429 { 430 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 431 } 432 433 void rt_cache_flush(struct net *net) 434 { 435 rt_genid_bump_ipv4(net); 436 } 437 438 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 439 struct sk_buff *skb, 440 const void *daddr) 441 { 442 struct net_device *dev = dst->dev; 443 const __be32 *pkey = daddr; 444 const struct rtable *rt; 445 struct neighbour *n; 446 447 rt = (const struct rtable *) dst; 448 if (rt->rt_gateway) 449 pkey = (const __be32 *) &rt->rt_gateway; 450 else if (skb) 451 pkey = &ip_hdr(skb)->daddr; 452 453 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 454 if (n) 455 return n; 456 return neigh_create(&arp_tbl, pkey, dev); 457 } 458 459 #define IP_IDENTS_SZ 2048u 460 struct ip_ident_bucket { 461 atomic_t id; 462 u32 stamp32; 463 }; 464 465 static struct ip_ident_bucket *ip_idents __read_mostly; 466 467 /* In order to protect privacy, we add a perturbation to identifiers 468 * if one generator is seldom used. This makes hard for an attacker 469 * to infer how many packets were sent between two points in time. 470 */ 471 u32 ip_idents_reserve(u32 hash, int segs) 472 { 473 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ; 474 u32 old = ACCESS_ONCE(bucket->stamp32); 475 u32 now = (u32)jiffies; 476 u32 delta = 0; 477 478 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old) 479 delta = prandom_u32_max(now - old); 480 481 return atomic_add_return(segs + delta, &bucket->id) - segs; 482 } 483 EXPORT_SYMBOL(ip_idents_reserve); 484 485 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 486 { 487 static u32 ip_idents_hashrnd __read_mostly; 488 u32 hash, id; 489 490 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); 491 492 hash = jhash_3words((__force u32)iph->daddr, 493 (__force u32)iph->saddr, 494 iph->protocol ^ net_hash_mix(net), 495 ip_idents_hashrnd); 496 id = ip_idents_reserve(hash, segs); 497 iph->id = htons(id); 498 } 499 EXPORT_SYMBOL(__ip_select_ident); 500 501 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, 502 const struct iphdr *iph, 503 int oif, u8 tos, 504 u8 prot, u32 mark, int flow_flags) 505 { 506 if (sk) { 507 const struct inet_sock *inet = inet_sk(sk); 508 509 oif = sk->sk_bound_dev_if; 510 mark = sk->sk_mark; 511 tos = RT_CONN_FLAGS(sk); 512 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 513 } 514 flowi4_init_output(fl4, oif, mark, tos, 515 RT_SCOPE_UNIVERSE, prot, 516 flow_flags, 517 iph->daddr, iph->saddr, 0, 0); 518 } 519 520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 521 const struct sock *sk) 522 { 523 const struct iphdr *iph = ip_hdr(skb); 524 int oif = skb->dev->ifindex; 525 u8 tos = RT_TOS(iph->tos); 526 u8 prot = iph->protocol; 527 u32 mark = skb->mark; 528 529 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0); 530 } 531 532 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 533 { 534 const struct inet_sock *inet = inet_sk(sk); 535 const struct ip_options_rcu *inet_opt; 536 __be32 daddr = inet->inet_daddr; 537 538 rcu_read_lock(); 539 inet_opt = rcu_dereference(inet->inet_opt); 540 if (inet_opt && inet_opt->opt.srr) 541 daddr = inet_opt->opt.faddr; 542 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 543 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 544 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 545 inet_sk_flowi_flags(sk), 546 daddr, inet->inet_saddr, 0, 0); 547 rcu_read_unlock(); 548 } 549 550 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 551 const struct sk_buff *skb) 552 { 553 if (skb) 554 build_skb_flow_key(fl4, skb, sk); 555 else 556 build_sk_flow_key(fl4, sk); 557 } 558 559 static inline void rt_free(struct rtable *rt) 560 { 561 call_rcu(&rt->dst.rcu_head, dst_rcu_free); 562 } 563 564 static DEFINE_SPINLOCK(fnhe_lock); 565 566 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 567 { 568 struct rtable *rt; 569 570 rt = rcu_dereference(fnhe->fnhe_rth_input); 571 if (rt) { 572 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 573 rt_free(rt); 574 } 575 rt = rcu_dereference(fnhe->fnhe_rth_output); 576 if (rt) { 577 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 578 rt_free(rt); 579 } 580 } 581 582 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 583 { 584 struct fib_nh_exception *fnhe, *oldest; 585 586 oldest = rcu_dereference(hash->chain); 587 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 588 fnhe = rcu_dereference(fnhe->fnhe_next)) { 589 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 590 oldest = fnhe; 591 } 592 fnhe_flush_routes(oldest); 593 return oldest; 594 } 595 596 static inline u32 fnhe_hashfun(__be32 daddr) 597 { 598 static u32 fnhe_hashrnd __read_mostly; 599 u32 hval; 600 601 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 602 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 603 return hash_32(hval, FNHE_HASH_SHIFT); 604 } 605 606 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 607 { 608 rt->rt_pmtu = fnhe->fnhe_pmtu; 609 rt->dst.expires = fnhe->fnhe_expires; 610 611 if (fnhe->fnhe_gw) { 612 rt->rt_flags |= RTCF_REDIRECTED; 613 rt->rt_gateway = fnhe->fnhe_gw; 614 rt->rt_uses_gateway = 1; 615 } 616 } 617 618 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 619 u32 pmtu, unsigned long expires) 620 { 621 struct fnhe_hash_bucket *hash; 622 struct fib_nh_exception *fnhe; 623 struct rtable *rt; 624 unsigned int i; 625 int depth; 626 u32 hval = fnhe_hashfun(daddr); 627 628 spin_lock_bh(&fnhe_lock); 629 630 hash = rcu_dereference(nh->nh_exceptions); 631 if (!hash) { 632 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); 633 if (!hash) 634 goto out_unlock; 635 rcu_assign_pointer(nh->nh_exceptions, hash); 636 } 637 638 hash += hval; 639 640 depth = 0; 641 for (fnhe = rcu_dereference(hash->chain); fnhe; 642 fnhe = rcu_dereference(fnhe->fnhe_next)) { 643 if (fnhe->fnhe_daddr == daddr) 644 break; 645 depth++; 646 } 647 648 if (fnhe) { 649 if (gw) 650 fnhe->fnhe_gw = gw; 651 if (pmtu) { 652 fnhe->fnhe_pmtu = pmtu; 653 fnhe->fnhe_expires = max(1UL, expires); 654 } 655 /* Update all cached dsts too */ 656 rt = rcu_dereference(fnhe->fnhe_rth_input); 657 if (rt) 658 fill_route_from_fnhe(rt, fnhe); 659 rt = rcu_dereference(fnhe->fnhe_rth_output); 660 if (rt) 661 fill_route_from_fnhe(rt, fnhe); 662 } else { 663 if (depth > FNHE_RECLAIM_DEPTH) 664 fnhe = fnhe_oldest(hash); 665 else { 666 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 667 if (!fnhe) 668 goto out_unlock; 669 670 fnhe->fnhe_next = hash->chain; 671 rcu_assign_pointer(hash->chain, fnhe); 672 } 673 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev)); 674 fnhe->fnhe_daddr = daddr; 675 fnhe->fnhe_gw = gw; 676 fnhe->fnhe_pmtu = pmtu; 677 fnhe->fnhe_expires = expires; 678 679 /* Exception created; mark the cached routes for the nexthop 680 * stale, so anyone caching it rechecks if this exception 681 * applies to them. 682 */ 683 rt = rcu_dereference(nh->nh_rth_input); 684 if (rt) 685 rt->dst.obsolete = DST_OBSOLETE_KILL; 686 687 for_each_possible_cpu(i) { 688 struct rtable __rcu **prt; 689 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 690 rt = rcu_dereference(*prt); 691 if (rt) 692 rt->dst.obsolete = DST_OBSOLETE_KILL; 693 } 694 } 695 696 fnhe->fnhe_stamp = jiffies; 697 698 out_unlock: 699 spin_unlock_bh(&fnhe_lock); 700 } 701 702 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 703 bool kill_route) 704 { 705 __be32 new_gw = icmp_hdr(skb)->un.gateway; 706 __be32 old_gw = ip_hdr(skb)->saddr; 707 struct net_device *dev = skb->dev; 708 struct in_device *in_dev; 709 struct fib_result res; 710 struct neighbour *n; 711 struct net *net; 712 713 switch (icmp_hdr(skb)->code & 7) { 714 case ICMP_REDIR_NET: 715 case ICMP_REDIR_NETTOS: 716 case ICMP_REDIR_HOST: 717 case ICMP_REDIR_HOSTTOS: 718 break; 719 720 default: 721 return; 722 } 723 724 if (rt->rt_gateway != old_gw) 725 return; 726 727 in_dev = __in_dev_get_rcu(dev); 728 if (!in_dev) 729 return; 730 731 net = dev_net(dev); 732 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 733 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 734 ipv4_is_zeronet(new_gw)) 735 goto reject_redirect; 736 737 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 738 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 739 goto reject_redirect; 740 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 741 goto reject_redirect; 742 } else { 743 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 744 goto reject_redirect; 745 } 746 747 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); 748 if (!IS_ERR(n)) { 749 if (!(n->nud_state & NUD_VALID)) { 750 neigh_event_send(n, NULL); 751 } else { 752 if (fib_lookup(net, fl4, &res) == 0) { 753 struct fib_nh *nh = &FIB_RES_NH(res); 754 755 update_or_create_fnhe(nh, fl4->daddr, new_gw, 756 0, 0); 757 } 758 if (kill_route) 759 rt->dst.obsolete = DST_OBSOLETE_KILL; 760 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 761 } 762 neigh_release(n); 763 } 764 return; 765 766 reject_redirect: 767 #ifdef CONFIG_IP_ROUTE_VERBOSE 768 if (IN_DEV_LOG_MARTIANS(in_dev)) { 769 const struct iphdr *iph = (const struct iphdr *) skb->data; 770 __be32 daddr = iph->daddr; 771 __be32 saddr = iph->saddr; 772 773 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 774 " Advised path = %pI4 -> %pI4\n", 775 &old_gw, dev->name, &new_gw, 776 &saddr, &daddr); 777 } 778 #endif 779 ; 780 } 781 782 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 783 { 784 struct rtable *rt; 785 struct flowi4 fl4; 786 const struct iphdr *iph = (const struct iphdr *) skb->data; 787 int oif = skb->dev->ifindex; 788 u8 tos = RT_TOS(iph->tos); 789 u8 prot = iph->protocol; 790 u32 mark = skb->mark; 791 792 rt = (struct rtable *) dst; 793 794 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0); 795 __ip_do_redirect(rt, skb, &fl4, true); 796 } 797 798 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 799 { 800 struct rtable *rt = (struct rtable *)dst; 801 struct dst_entry *ret = dst; 802 803 if (rt) { 804 if (dst->obsolete > 0) { 805 ip_rt_put(rt); 806 ret = NULL; 807 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 808 rt->dst.expires) { 809 ip_rt_put(rt); 810 ret = NULL; 811 } 812 } 813 return ret; 814 } 815 816 /* 817 * Algorithm: 818 * 1. The first ip_rt_redirect_number redirects are sent 819 * with exponential backoff, then we stop sending them at all, 820 * assuming that the host ignores our redirects. 821 * 2. If we did not see packets requiring redirects 822 * during ip_rt_redirect_silence, we assume that the host 823 * forgot redirected route and start to send redirects again. 824 * 825 * This algorithm is much cheaper and more intelligent than dumb load limiting 826 * in icmp.c. 827 * 828 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 829 * and "frag. need" (breaks PMTU discovery) in icmp.c. 830 */ 831 832 void ip_rt_send_redirect(struct sk_buff *skb) 833 { 834 struct rtable *rt = skb_rtable(skb); 835 struct in_device *in_dev; 836 struct inet_peer *peer; 837 struct net *net; 838 int log_martians; 839 840 rcu_read_lock(); 841 in_dev = __in_dev_get_rcu(rt->dst.dev); 842 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 843 rcu_read_unlock(); 844 return; 845 } 846 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 847 rcu_read_unlock(); 848 849 net = dev_net(rt->dst.dev); 850 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 851 if (!peer) { 852 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 853 rt_nexthop(rt, ip_hdr(skb)->daddr)); 854 return; 855 } 856 857 /* No redirected packets during ip_rt_redirect_silence; 858 * reset the algorithm. 859 */ 860 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 861 peer->rate_tokens = 0; 862 863 /* Too many ignored redirects; do not send anything 864 * set dst.rate_last to the last seen redirected packet. 865 */ 866 if (peer->rate_tokens >= ip_rt_redirect_number) { 867 peer->rate_last = jiffies; 868 goto out_put_peer; 869 } 870 871 /* Check for load limit; set rate_last to the latest sent 872 * redirect. 873 */ 874 if (peer->rate_tokens == 0 || 875 time_after(jiffies, 876 (peer->rate_last + 877 (ip_rt_redirect_load << peer->rate_tokens)))) { 878 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 879 880 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 881 peer->rate_last = jiffies; 882 ++peer->rate_tokens; 883 #ifdef CONFIG_IP_ROUTE_VERBOSE 884 if (log_martians && 885 peer->rate_tokens == ip_rt_redirect_number) 886 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 887 &ip_hdr(skb)->saddr, inet_iif(skb), 888 &ip_hdr(skb)->daddr, &gw); 889 #endif 890 } 891 out_put_peer: 892 inet_putpeer(peer); 893 } 894 895 static int ip_error(struct sk_buff *skb) 896 { 897 struct in_device *in_dev = __in_dev_get_rcu(skb->dev); 898 struct rtable *rt = skb_rtable(skb); 899 struct inet_peer *peer; 900 unsigned long now; 901 struct net *net; 902 bool send; 903 int code; 904 905 net = dev_net(rt->dst.dev); 906 if (!IN_DEV_FORWARD(in_dev)) { 907 switch (rt->dst.error) { 908 case EHOSTUNREACH: 909 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); 910 break; 911 912 case ENETUNREACH: 913 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 914 break; 915 } 916 goto out; 917 } 918 919 switch (rt->dst.error) { 920 case EINVAL: 921 default: 922 goto out; 923 case EHOSTUNREACH: 924 code = ICMP_HOST_UNREACH; 925 break; 926 case ENETUNREACH: 927 code = ICMP_NET_UNREACH; 928 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 929 break; 930 case EACCES: 931 code = ICMP_PKT_FILTERED; 932 break; 933 } 934 935 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 936 937 send = true; 938 if (peer) { 939 now = jiffies; 940 peer->rate_tokens += now - peer->rate_last; 941 if (peer->rate_tokens > ip_rt_error_burst) 942 peer->rate_tokens = ip_rt_error_burst; 943 peer->rate_last = now; 944 if (peer->rate_tokens >= ip_rt_error_cost) 945 peer->rate_tokens -= ip_rt_error_cost; 946 else 947 send = false; 948 inet_putpeer(peer); 949 } 950 if (send) 951 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 952 953 out: kfree_skb(skb); 954 return 0; 955 } 956 957 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 958 { 959 struct dst_entry *dst = &rt->dst; 960 struct fib_result res; 961 962 if (dst_metric_locked(dst, RTAX_MTU)) 963 return; 964 965 if (ipv4_mtu(dst) < mtu) 966 return; 967 968 if (mtu < ip_rt_min_pmtu) 969 mtu = ip_rt_min_pmtu; 970 971 if (rt->rt_pmtu == mtu && 972 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 973 return; 974 975 rcu_read_lock(); 976 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) { 977 struct fib_nh *nh = &FIB_RES_NH(res); 978 979 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, 980 jiffies + ip_rt_mtu_expires); 981 } 982 rcu_read_unlock(); 983 } 984 985 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 986 struct sk_buff *skb, u32 mtu) 987 { 988 struct rtable *rt = (struct rtable *) dst; 989 struct flowi4 fl4; 990 991 ip_rt_build_flow_key(&fl4, sk, skb); 992 __ip_rt_update_pmtu(rt, &fl4, mtu); 993 } 994 995 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 996 int oif, u32 mark, u8 protocol, int flow_flags) 997 { 998 const struct iphdr *iph = (const struct iphdr *) skb->data; 999 struct flowi4 fl4; 1000 struct rtable *rt; 1001 1002 if (!mark) 1003 mark = IP4_REPLY_MARK(net, skb->mark); 1004 1005 __build_flow_key(&fl4, NULL, iph, oif, 1006 RT_TOS(iph->tos), protocol, mark, flow_flags); 1007 rt = __ip_route_output_key(net, &fl4); 1008 if (!IS_ERR(rt)) { 1009 __ip_rt_update_pmtu(rt, &fl4, mtu); 1010 ip_rt_put(rt); 1011 } 1012 } 1013 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1014 1015 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1016 { 1017 const struct iphdr *iph = (const struct iphdr *) skb->data; 1018 struct flowi4 fl4; 1019 struct rtable *rt; 1020 1021 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1022 1023 if (!fl4.flowi4_mark) 1024 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1025 1026 rt = __ip_route_output_key(sock_net(sk), &fl4); 1027 if (!IS_ERR(rt)) { 1028 __ip_rt_update_pmtu(rt, &fl4, mtu); 1029 ip_rt_put(rt); 1030 } 1031 } 1032 1033 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1034 { 1035 const struct iphdr *iph = (const struct iphdr *) skb->data; 1036 struct flowi4 fl4; 1037 struct rtable *rt; 1038 struct dst_entry *odst = NULL; 1039 bool new = false; 1040 1041 bh_lock_sock(sk); 1042 1043 if (!ip_sk_accept_pmtu(sk)) 1044 goto out; 1045 1046 odst = sk_dst_get(sk); 1047 1048 if (sock_owned_by_user(sk) || !odst) { 1049 __ipv4_sk_update_pmtu(skb, sk, mtu); 1050 goto out; 1051 } 1052 1053 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1054 1055 rt = (struct rtable *)odst; 1056 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1057 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1058 if (IS_ERR(rt)) 1059 goto out; 1060 1061 new = true; 1062 } 1063 1064 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); 1065 1066 if (!dst_check(&rt->dst, 0)) { 1067 if (new) 1068 dst_release(&rt->dst); 1069 1070 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1071 if (IS_ERR(rt)) 1072 goto out; 1073 1074 new = true; 1075 } 1076 1077 if (new) 1078 sk_dst_set(sk, &rt->dst); 1079 1080 out: 1081 bh_unlock_sock(sk); 1082 dst_release(odst); 1083 } 1084 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1085 1086 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1087 int oif, u32 mark, u8 protocol, int flow_flags) 1088 { 1089 const struct iphdr *iph = (const struct iphdr *) skb->data; 1090 struct flowi4 fl4; 1091 struct rtable *rt; 1092 1093 __build_flow_key(&fl4, NULL, iph, oif, 1094 RT_TOS(iph->tos), protocol, mark, flow_flags); 1095 rt = __ip_route_output_key(net, &fl4); 1096 if (!IS_ERR(rt)) { 1097 __ip_do_redirect(rt, skb, &fl4, false); 1098 ip_rt_put(rt); 1099 } 1100 } 1101 EXPORT_SYMBOL_GPL(ipv4_redirect); 1102 1103 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1104 { 1105 const struct iphdr *iph = (const struct iphdr *) skb->data; 1106 struct flowi4 fl4; 1107 struct rtable *rt; 1108 1109 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1110 rt = __ip_route_output_key(sock_net(sk), &fl4); 1111 if (!IS_ERR(rt)) { 1112 __ip_do_redirect(rt, skb, &fl4, false); 1113 ip_rt_put(rt); 1114 } 1115 } 1116 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1117 1118 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1119 { 1120 struct rtable *rt = (struct rtable *) dst; 1121 1122 /* All IPV4 dsts are created with ->obsolete set to the value 1123 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1124 * into this function always. 1125 * 1126 * When a PMTU/redirect information update invalidates a route, 1127 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1128 * DST_OBSOLETE_DEAD by dst_free(). 1129 */ 1130 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1131 return NULL; 1132 return dst; 1133 } 1134 1135 static void ipv4_link_failure(struct sk_buff *skb) 1136 { 1137 struct rtable *rt; 1138 1139 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1140 1141 rt = skb_rtable(skb); 1142 if (rt) 1143 dst_set_expires(&rt->dst, 0); 1144 } 1145 1146 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb) 1147 { 1148 pr_debug("%s: %pI4 -> %pI4, %s\n", 1149 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1150 skb->dev ? skb->dev->name : "?"); 1151 kfree_skb(skb); 1152 WARN_ON(1); 1153 return 0; 1154 } 1155 1156 /* 1157 We do not cache source address of outgoing interface, 1158 because it is used only by IP RR, TS and SRR options, 1159 so that it out of fast path. 1160 1161 BTW remember: "addr" is allowed to be not aligned 1162 in IP options! 1163 */ 1164 1165 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1166 { 1167 __be32 src; 1168 1169 if (rt_is_output_route(rt)) 1170 src = ip_hdr(skb)->saddr; 1171 else { 1172 struct fib_result res; 1173 struct flowi4 fl4; 1174 struct iphdr *iph; 1175 1176 iph = ip_hdr(skb); 1177 1178 memset(&fl4, 0, sizeof(fl4)); 1179 fl4.daddr = iph->daddr; 1180 fl4.saddr = iph->saddr; 1181 fl4.flowi4_tos = RT_TOS(iph->tos); 1182 fl4.flowi4_oif = rt->dst.dev->ifindex; 1183 fl4.flowi4_iif = skb->dev->ifindex; 1184 fl4.flowi4_mark = skb->mark; 1185 1186 rcu_read_lock(); 1187 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1188 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1189 else 1190 src = inet_select_addr(rt->dst.dev, 1191 rt_nexthop(rt, iph->daddr), 1192 RT_SCOPE_UNIVERSE); 1193 rcu_read_unlock(); 1194 } 1195 memcpy(addr, &src, 4); 1196 } 1197 1198 #ifdef CONFIG_IP_ROUTE_CLASSID 1199 static void set_class_tag(struct rtable *rt, u32 tag) 1200 { 1201 if (!(rt->dst.tclassid & 0xFFFF)) 1202 rt->dst.tclassid |= tag & 0xFFFF; 1203 if (!(rt->dst.tclassid & 0xFFFF0000)) 1204 rt->dst.tclassid |= tag & 0xFFFF0000; 1205 } 1206 #endif 1207 1208 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1209 { 1210 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1211 1212 if (advmss == 0) { 1213 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1214 ip_rt_min_advmss); 1215 if (advmss > 65535 - 40) 1216 advmss = 65535 - 40; 1217 } 1218 return advmss; 1219 } 1220 1221 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1222 { 1223 const struct rtable *rt = (const struct rtable *) dst; 1224 unsigned int mtu = rt->rt_pmtu; 1225 1226 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1227 mtu = dst_metric_raw(dst, RTAX_MTU); 1228 1229 if (mtu) 1230 return mtu; 1231 1232 mtu = dst->dev->mtu; 1233 1234 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1235 if (rt->rt_uses_gateway && mtu > 576) 1236 mtu = 576; 1237 } 1238 1239 return min_t(unsigned int, mtu, IP_MAX_MTU); 1240 } 1241 1242 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1243 { 1244 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1245 struct fib_nh_exception *fnhe; 1246 u32 hval; 1247 1248 if (!hash) 1249 return NULL; 1250 1251 hval = fnhe_hashfun(daddr); 1252 1253 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1254 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1255 if (fnhe->fnhe_daddr == daddr) 1256 return fnhe; 1257 } 1258 return NULL; 1259 } 1260 1261 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1262 __be32 daddr) 1263 { 1264 bool ret = false; 1265 1266 spin_lock_bh(&fnhe_lock); 1267 1268 if (daddr == fnhe->fnhe_daddr) { 1269 struct rtable __rcu **porig; 1270 struct rtable *orig; 1271 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1272 1273 if (rt_is_input_route(rt)) 1274 porig = &fnhe->fnhe_rth_input; 1275 else 1276 porig = &fnhe->fnhe_rth_output; 1277 orig = rcu_dereference(*porig); 1278 1279 if (fnhe->fnhe_genid != genid) { 1280 fnhe->fnhe_genid = genid; 1281 fnhe->fnhe_gw = 0; 1282 fnhe->fnhe_pmtu = 0; 1283 fnhe->fnhe_expires = 0; 1284 fnhe_flush_routes(fnhe); 1285 orig = NULL; 1286 } 1287 fill_route_from_fnhe(rt, fnhe); 1288 if (!rt->rt_gateway) 1289 rt->rt_gateway = daddr; 1290 1291 if (!(rt->dst.flags & DST_NOCACHE)) { 1292 rcu_assign_pointer(*porig, rt); 1293 if (orig) 1294 rt_free(orig); 1295 ret = true; 1296 } 1297 1298 fnhe->fnhe_stamp = jiffies; 1299 } 1300 spin_unlock_bh(&fnhe_lock); 1301 1302 return ret; 1303 } 1304 1305 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1306 { 1307 struct rtable *orig, *prev, **p; 1308 bool ret = true; 1309 1310 if (rt_is_input_route(rt)) { 1311 p = (struct rtable **)&nh->nh_rth_input; 1312 } else { 1313 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1314 } 1315 orig = *p; 1316 1317 prev = cmpxchg(p, orig, rt); 1318 if (prev == orig) { 1319 if (orig) 1320 rt_free(orig); 1321 } else 1322 ret = false; 1323 1324 return ret; 1325 } 1326 1327 struct uncached_list { 1328 spinlock_t lock; 1329 struct list_head head; 1330 }; 1331 1332 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1333 1334 static void rt_add_uncached_list(struct rtable *rt) 1335 { 1336 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1337 1338 rt->rt_uncached_list = ul; 1339 1340 spin_lock_bh(&ul->lock); 1341 list_add_tail(&rt->rt_uncached, &ul->head); 1342 spin_unlock_bh(&ul->lock); 1343 } 1344 1345 static void ipv4_dst_destroy(struct dst_entry *dst) 1346 { 1347 struct rtable *rt = (struct rtable *) dst; 1348 1349 if (!list_empty(&rt->rt_uncached)) { 1350 struct uncached_list *ul = rt->rt_uncached_list; 1351 1352 spin_lock_bh(&ul->lock); 1353 list_del(&rt->rt_uncached); 1354 spin_unlock_bh(&ul->lock); 1355 } 1356 } 1357 1358 void rt_flush_dev(struct net_device *dev) 1359 { 1360 struct net *net = dev_net(dev); 1361 struct rtable *rt; 1362 int cpu; 1363 1364 for_each_possible_cpu(cpu) { 1365 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1366 1367 spin_lock_bh(&ul->lock); 1368 list_for_each_entry(rt, &ul->head, rt_uncached) { 1369 if (rt->dst.dev != dev) 1370 continue; 1371 rt->dst.dev = net->loopback_dev; 1372 dev_hold(rt->dst.dev); 1373 dev_put(dev); 1374 } 1375 spin_unlock_bh(&ul->lock); 1376 } 1377 } 1378 1379 static bool rt_cache_valid(const struct rtable *rt) 1380 { 1381 return rt && 1382 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1383 !rt_is_expired(rt); 1384 } 1385 1386 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1387 const struct fib_result *res, 1388 struct fib_nh_exception *fnhe, 1389 struct fib_info *fi, u16 type, u32 itag) 1390 { 1391 bool cached = false; 1392 1393 if (fi) { 1394 struct fib_nh *nh = &FIB_RES_NH(*res); 1395 1396 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1397 rt->rt_gateway = nh->nh_gw; 1398 rt->rt_uses_gateway = 1; 1399 } 1400 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1401 #ifdef CONFIG_IP_ROUTE_CLASSID 1402 rt->dst.tclassid = nh->nh_tclassid; 1403 #endif 1404 if (unlikely(fnhe)) 1405 cached = rt_bind_exception(rt, fnhe, daddr); 1406 else if (!(rt->dst.flags & DST_NOCACHE)) 1407 cached = rt_cache_route(nh, rt); 1408 if (unlikely(!cached)) { 1409 /* Routes we intend to cache in nexthop exception or 1410 * FIB nexthop have the DST_NOCACHE bit clear. 1411 * However, if we are unsuccessful at storing this 1412 * route into the cache we really need to set it. 1413 */ 1414 rt->dst.flags |= DST_NOCACHE; 1415 if (!rt->rt_gateway) 1416 rt->rt_gateway = daddr; 1417 rt_add_uncached_list(rt); 1418 } 1419 } else 1420 rt_add_uncached_list(rt); 1421 1422 #ifdef CONFIG_IP_ROUTE_CLASSID 1423 #ifdef CONFIG_IP_MULTIPLE_TABLES 1424 set_class_tag(rt, res->tclassid); 1425 #endif 1426 set_class_tag(rt, itag); 1427 #endif 1428 } 1429 1430 static struct rtable *rt_dst_alloc(struct net_device *dev, 1431 bool nopolicy, bool noxfrm, bool will_cache) 1432 { 1433 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1434 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1435 (nopolicy ? DST_NOPOLICY : 0) | 1436 (noxfrm ? DST_NOXFRM : 0)); 1437 } 1438 1439 /* called in rcu_read_lock() section */ 1440 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1441 u8 tos, struct net_device *dev, int our) 1442 { 1443 struct rtable *rth; 1444 struct in_device *in_dev = __in_dev_get_rcu(dev); 1445 u32 itag = 0; 1446 int err; 1447 1448 /* Primary sanity checks. */ 1449 1450 if (!in_dev) 1451 return -EINVAL; 1452 1453 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1454 skb->protocol != htons(ETH_P_IP)) 1455 goto e_inval; 1456 1457 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1458 if (ipv4_is_loopback(saddr)) 1459 goto e_inval; 1460 1461 if (ipv4_is_zeronet(saddr)) { 1462 if (!ipv4_is_local_multicast(daddr)) 1463 goto e_inval; 1464 } else { 1465 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1466 in_dev, &itag); 1467 if (err < 0) 1468 goto e_err; 1469 } 1470 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, 1471 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1472 if (!rth) 1473 goto e_nobufs; 1474 1475 #ifdef CONFIG_IP_ROUTE_CLASSID 1476 rth->dst.tclassid = itag; 1477 #endif 1478 rth->dst.output = ip_rt_bug; 1479 1480 rth->rt_genid = rt_genid_ipv4(dev_net(dev)); 1481 rth->rt_flags = RTCF_MULTICAST; 1482 rth->rt_type = RTN_MULTICAST; 1483 rth->rt_is_input= 1; 1484 rth->rt_iif = 0; 1485 rth->rt_pmtu = 0; 1486 rth->rt_gateway = 0; 1487 rth->rt_uses_gateway = 0; 1488 INIT_LIST_HEAD(&rth->rt_uncached); 1489 if (our) { 1490 rth->dst.input= ip_local_deliver; 1491 rth->rt_flags |= RTCF_LOCAL; 1492 } 1493 1494 #ifdef CONFIG_IP_MROUTE 1495 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1496 rth->dst.input = ip_mr_input; 1497 #endif 1498 RT_CACHE_STAT_INC(in_slow_mc); 1499 1500 skb_dst_set(skb, &rth->dst); 1501 return 0; 1502 1503 e_nobufs: 1504 return -ENOBUFS; 1505 e_inval: 1506 return -EINVAL; 1507 e_err: 1508 return err; 1509 } 1510 1511 1512 static void ip_handle_martian_source(struct net_device *dev, 1513 struct in_device *in_dev, 1514 struct sk_buff *skb, 1515 __be32 daddr, 1516 __be32 saddr) 1517 { 1518 RT_CACHE_STAT_INC(in_martian_src); 1519 #ifdef CONFIG_IP_ROUTE_VERBOSE 1520 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1521 /* 1522 * RFC1812 recommendation, if source is martian, 1523 * the only hint is MAC header. 1524 */ 1525 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1526 &daddr, &saddr, dev->name); 1527 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1528 print_hex_dump(KERN_WARNING, "ll header: ", 1529 DUMP_PREFIX_OFFSET, 16, 1, 1530 skb_mac_header(skb), 1531 dev->hard_header_len, true); 1532 } 1533 } 1534 #endif 1535 } 1536 1537 /* called in rcu_read_lock() section */ 1538 static int __mkroute_input(struct sk_buff *skb, 1539 const struct fib_result *res, 1540 struct in_device *in_dev, 1541 __be32 daddr, __be32 saddr, u32 tos) 1542 { 1543 struct fib_nh_exception *fnhe; 1544 struct rtable *rth; 1545 int err; 1546 struct in_device *out_dev; 1547 unsigned int flags = 0; 1548 bool do_cache; 1549 u32 itag = 0; 1550 1551 /* get a working reference to the output device */ 1552 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1553 if (!out_dev) { 1554 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1555 return -EINVAL; 1556 } 1557 1558 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1559 in_dev->dev, in_dev, &itag); 1560 if (err < 0) { 1561 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1562 saddr); 1563 1564 goto cleanup; 1565 } 1566 1567 do_cache = res->fi && !itag; 1568 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1569 skb->protocol == htons(ETH_P_IP) && 1570 (IN_DEV_SHARED_MEDIA(out_dev) || 1571 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1572 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1573 1574 if (skb->protocol != htons(ETH_P_IP)) { 1575 /* Not IP (i.e. ARP). Do not create route, if it is 1576 * invalid for proxy arp. DNAT routes are always valid. 1577 * 1578 * Proxy arp feature have been extended to allow, ARP 1579 * replies back to the same interface, to support 1580 * Private VLAN switch technologies. See arp.c. 1581 */ 1582 if (out_dev == in_dev && 1583 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1584 err = -EINVAL; 1585 goto cleanup; 1586 } 1587 } 1588 1589 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1590 if (do_cache) { 1591 if (fnhe) 1592 rth = rcu_dereference(fnhe->fnhe_rth_input); 1593 else 1594 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1595 1596 if (rt_cache_valid(rth)) { 1597 skb_dst_set_noref(skb, &rth->dst); 1598 goto out; 1599 } 1600 } 1601 1602 rth = rt_dst_alloc(out_dev->dev, 1603 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1604 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1605 if (!rth) { 1606 err = -ENOBUFS; 1607 goto cleanup; 1608 } 1609 1610 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev)); 1611 rth->rt_flags = flags; 1612 rth->rt_type = res->type; 1613 rth->rt_is_input = 1; 1614 rth->rt_iif = 0; 1615 rth->rt_pmtu = 0; 1616 rth->rt_gateway = 0; 1617 rth->rt_uses_gateway = 0; 1618 INIT_LIST_HEAD(&rth->rt_uncached); 1619 RT_CACHE_STAT_INC(in_slow_tot); 1620 1621 rth->dst.input = ip_forward; 1622 rth->dst.output = ip_output; 1623 1624 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); 1625 skb_dst_set(skb, &rth->dst); 1626 out: 1627 err = 0; 1628 cleanup: 1629 return err; 1630 } 1631 1632 static int ip_mkroute_input(struct sk_buff *skb, 1633 struct fib_result *res, 1634 const struct flowi4 *fl4, 1635 struct in_device *in_dev, 1636 __be32 daddr, __be32 saddr, u32 tos) 1637 { 1638 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1639 if (res->fi && res->fi->fib_nhs > 1) 1640 fib_select_multipath(res); 1641 #endif 1642 1643 /* create a routing cache entry */ 1644 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1645 } 1646 1647 /* 1648 * NOTE. We drop all the packets that has local source 1649 * addresses, because every properly looped back packet 1650 * must have correct destination already attached by output routine. 1651 * 1652 * Such approach solves two big problems: 1653 * 1. Not simplex devices are handled properly. 1654 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1655 * called with rcu_read_lock() 1656 */ 1657 1658 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1659 u8 tos, struct net_device *dev) 1660 { 1661 struct fib_result res; 1662 struct in_device *in_dev = __in_dev_get_rcu(dev); 1663 struct flowi4 fl4; 1664 unsigned int flags = 0; 1665 u32 itag = 0; 1666 struct rtable *rth; 1667 int err = -EINVAL; 1668 struct net *net = dev_net(dev); 1669 bool do_cache; 1670 1671 /* IP on this device is disabled. */ 1672 1673 if (!in_dev) 1674 goto out; 1675 1676 /* Check for the most weird martians, which can be not detected 1677 by fib_lookup. 1678 */ 1679 1680 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1681 goto martian_source; 1682 1683 res.fi = NULL; 1684 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1685 goto brd_input; 1686 1687 /* Accept zero addresses only to limited broadcast; 1688 * I even do not know to fix it or not. Waiting for complains :-) 1689 */ 1690 if (ipv4_is_zeronet(saddr)) 1691 goto martian_source; 1692 1693 if (ipv4_is_zeronet(daddr)) 1694 goto martian_destination; 1695 1696 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1697 * and call it once if daddr or/and saddr are loopback addresses 1698 */ 1699 if (ipv4_is_loopback(daddr)) { 1700 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1701 goto martian_destination; 1702 } else if (ipv4_is_loopback(saddr)) { 1703 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1704 goto martian_source; 1705 } 1706 1707 /* 1708 * Now we are ready to route packet. 1709 */ 1710 fl4.flowi4_oif = 0; 1711 fl4.flowi4_iif = dev->ifindex; 1712 fl4.flowi4_mark = skb->mark; 1713 fl4.flowi4_tos = tos; 1714 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1715 fl4.daddr = daddr; 1716 fl4.saddr = saddr; 1717 err = fib_lookup(net, &fl4, &res); 1718 if (err != 0) { 1719 if (!IN_DEV_FORWARD(in_dev)) 1720 err = -EHOSTUNREACH; 1721 goto no_route; 1722 } 1723 1724 if (res.type == RTN_BROADCAST) 1725 goto brd_input; 1726 1727 if (res.type == RTN_LOCAL) { 1728 err = fib_validate_source(skb, saddr, daddr, tos, 1729 0, dev, in_dev, &itag); 1730 if (err < 0) 1731 goto martian_source_keep_err; 1732 goto local_input; 1733 } 1734 1735 if (!IN_DEV_FORWARD(in_dev)) { 1736 err = -EHOSTUNREACH; 1737 goto no_route; 1738 } 1739 if (res.type != RTN_UNICAST) 1740 goto martian_destination; 1741 1742 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1743 out: return err; 1744 1745 brd_input: 1746 if (skb->protocol != htons(ETH_P_IP)) 1747 goto e_inval; 1748 1749 if (!ipv4_is_zeronet(saddr)) { 1750 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1751 in_dev, &itag); 1752 if (err < 0) 1753 goto martian_source_keep_err; 1754 } 1755 flags |= RTCF_BROADCAST; 1756 res.type = RTN_BROADCAST; 1757 RT_CACHE_STAT_INC(in_brd); 1758 1759 local_input: 1760 do_cache = false; 1761 if (res.fi) { 1762 if (!itag) { 1763 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1764 if (rt_cache_valid(rth)) { 1765 skb_dst_set_noref(skb, &rth->dst); 1766 err = 0; 1767 goto out; 1768 } 1769 do_cache = true; 1770 } 1771 } 1772 1773 rth = rt_dst_alloc(net->loopback_dev, 1774 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1775 if (!rth) 1776 goto e_nobufs; 1777 1778 rth->dst.input= ip_local_deliver; 1779 rth->dst.output= ip_rt_bug; 1780 #ifdef CONFIG_IP_ROUTE_CLASSID 1781 rth->dst.tclassid = itag; 1782 #endif 1783 1784 rth->rt_genid = rt_genid_ipv4(net); 1785 rth->rt_flags = flags|RTCF_LOCAL; 1786 rth->rt_type = res.type; 1787 rth->rt_is_input = 1; 1788 rth->rt_iif = 0; 1789 rth->rt_pmtu = 0; 1790 rth->rt_gateway = 0; 1791 rth->rt_uses_gateway = 0; 1792 INIT_LIST_HEAD(&rth->rt_uncached); 1793 RT_CACHE_STAT_INC(in_slow_tot); 1794 if (res.type == RTN_UNREACHABLE) { 1795 rth->dst.input= ip_error; 1796 rth->dst.error= -err; 1797 rth->rt_flags &= ~RTCF_LOCAL; 1798 } 1799 if (do_cache) { 1800 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { 1801 rth->dst.flags |= DST_NOCACHE; 1802 rt_add_uncached_list(rth); 1803 } 1804 } 1805 skb_dst_set(skb, &rth->dst); 1806 err = 0; 1807 goto out; 1808 1809 no_route: 1810 RT_CACHE_STAT_INC(in_no_route); 1811 res.type = RTN_UNREACHABLE; 1812 res.fi = NULL; 1813 goto local_input; 1814 1815 /* 1816 * Do not cache martian addresses: they should be logged (RFC1812) 1817 */ 1818 martian_destination: 1819 RT_CACHE_STAT_INC(in_martian_dst); 1820 #ifdef CONFIG_IP_ROUTE_VERBOSE 1821 if (IN_DEV_LOG_MARTIANS(in_dev)) 1822 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1823 &daddr, &saddr, dev->name); 1824 #endif 1825 1826 e_inval: 1827 err = -EINVAL; 1828 goto out; 1829 1830 e_nobufs: 1831 err = -ENOBUFS; 1832 goto out; 1833 1834 martian_source: 1835 err = -EINVAL; 1836 martian_source_keep_err: 1837 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1838 goto out; 1839 } 1840 1841 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1842 u8 tos, struct net_device *dev) 1843 { 1844 int res; 1845 1846 rcu_read_lock(); 1847 1848 /* Multicast recognition logic is moved from route cache to here. 1849 The problem was that too many Ethernet cards have broken/missing 1850 hardware multicast filters :-( As result the host on multicasting 1851 network acquires a lot of useless route cache entries, sort of 1852 SDR messages from all the world. Now we try to get rid of them. 1853 Really, provided software IP multicast filter is organized 1854 reasonably (at least, hashed), it does not result in a slowdown 1855 comparing with route cache reject entries. 1856 Note, that multicast routers are not affected, because 1857 route cache entry is created eventually. 1858 */ 1859 if (ipv4_is_multicast(daddr)) { 1860 struct in_device *in_dev = __in_dev_get_rcu(dev); 1861 1862 if (in_dev) { 1863 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1864 ip_hdr(skb)->protocol); 1865 if (our 1866 #ifdef CONFIG_IP_MROUTE 1867 || 1868 (!ipv4_is_local_multicast(daddr) && 1869 IN_DEV_MFORWARD(in_dev)) 1870 #endif 1871 ) { 1872 int res = ip_route_input_mc(skb, daddr, saddr, 1873 tos, dev, our); 1874 rcu_read_unlock(); 1875 return res; 1876 } 1877 } 1878 rcu_read_unlock(); 1879 return -EINVAL; 1880 } 1881 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1882 rcu_read_unlock(); 1883 return res; 1884 } 1885 EXPORT_SYMBOL(ip_route_input_noref); 1886 1887 /* called with rcu_read_lock() */ 1888 static struct rtable *__mkroute_output(const struct fib_result *res, 1889 const struct flowi4 *fl4, int orig_oif, 1890 struct net_device *dev_out, 1891 unsigned int flags) 1892 { 1893 struct fib_info *fi = res->fi; 1894 struct fib_nh_exception *fnhe; 1895 struct in_device *in_dev; 1896 u16 type = res->type; 1897 struct rtable *rth; 1898 bool do_cache; 1899 1900 in_dev = __in_dev_get_rcu(dev_out); 1901 if (!in_dev) 1902 return ERR_PTR(-EINVAL); 1903 1904 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1905 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1906 return ERR_PTR(-EINVAL); 1907 1908 if (ipv4_is_lbcast(fl4->daddr)) 1909 type = RTN_BROADCAST; 1910 else if (ipv4_is_multicast(fl4->daddr)) 1911 type = RTN_MULTICAST; 1912 else if (ipv4_is_zeronet(fl4->daddr)) 1913 return ERR_PTR(-EINVAL); 1914 1915 if (dev_out->flags & IFF_LOOPBACK) 1916 flags |= RTCF_LOCAL; 1917 1918 do_cache = true; 1919 if (type == RTN_BROADCAST) { 1920 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1921 fi = NULL; 1922 } else if (type == RTN_MULTICAST) { 1923 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1924 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1925 fl4->flowi4_proto)) 1926 flags &= ~RTCF_LOCAL; 1927 else 1928 do_cache = false; 1929 /* If multicast route do not exist use 1930 * default one, but do not gateway in this case. 1931 * Yes, it is hack. 1932 */ 1933 if (fi && res->prefixlen < 4) 1934 fi = NULL; 1935 } 1936 1937 fnhe = NULL; 1938 do_cache &= fi != NULL; 1939 if (do_cache) { 1940 struct rtable __rcu **prth; 1941 struct fib_nh *nh = &FIB_RES_NH(*res); 1942 1943 fnhe = find_exception(nh, fl4->daddr); 1944 if (fnhe) 1945 prth = &fnhe->fnhe_rth_output; 1946 else { 1947 if (unlikely(fl4->flowi4_flags & 1948 FLOWI_FLAG_KNOWN_NH && 1949 !(nh->nh_gw && 1950 nh->nh_scope == RT_SCOPE_LINK))) { 1951 do_cache = false; 1952 goto add; 1953 } 1954 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 1955 } 1956 rth = rcu_dereference(*prth); 1957 if (rt_cache_valid(rth)) { 1958 dst_hold(&rth->dst); 1959 return rth; 1960 } 1961 } 1962 1963 add: 1964 rth = rt_dst_alloc(dev_out, 1965 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1966 IN_DEV_CONF_GET(in_dev, NOXFRM), 1967 do_cache); 1968 if (!rth) 1969 return ERR_PTR(-ENOBUFS); 1970 1971 rth->dst.output = ip_output; 1972 1973 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out)); 1974 rth->rt_flags = flags; 1975 rth->rt_type = type; 1976 rth->rt_is_input = 0; 1977 rth->rt_iif = orig_oif ? : 0; 1978 rth->rt_pmtu = 0; 1979 rth->rt_gateway = 0; 1980 rth->rt_uses_gateway = 0; 1981 INIT_LIST_HEAD(&rth->rt_uncached); 1982 1983 RT_CACHE_STAT_INC(out_slow_tot); 1984 1985 if (flags & RTCF_LOCAL) 1986 rth->dst.input = ip_local_deliver; 1987 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 1988 if (flags & RTCF_LOCAL && 1989 !(dev_out->flags & IFF_LOOPBACK)) { 1990 rth->dst.output = ip_mc_output; 1991 RT_CACHE_STAT_INC(out_slow_mc); 1992 } 1993 #ifdef CONFIG_IP_MROUTE 1994 if (type == RTN_MULTICAST) { 1995 if (IN_DEV_MFORWARD(in_dev) && 1996 !ipv4_is_local_multicast(fl4->daddr)) { 1997 rth->dst.input = ip_mr_input; 1998 rth->dst.output = ip_mc_output; 1999 } 2000 } 2001 #endif 2002 } 2003 2004 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 2005 2006 return rth; 2007 } 2008 2009 /* 2010 * Major route resolver routine. 2011 */ 2012 2013 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 2014 { 2015 struct net_device *dev_out = NULL; 2016 __u8 tos = RT_FL_TOS(fl4); 2017 unsigned int flags = 0; 2018 struct fib_result res; 2019 struct rtable *rth; 2020 int orig_oif; 2021 2022 res.tclassid = 0; 2023 res.fi = NULL; 2024 res.table = NULL; 2025 2026 orig_oif = fl4->flowi4_oif; 2027 2028 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2029 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2030 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2031 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2032 2033 rcu_read_lock(); 2034 if (fl4->saddr) { 2035 rth = ERR_PTR(-EINVAL); 2036 if (ipv4_is_multicast(fl4->saddr) || 2037 ipv4_is_lbcast(fl4->saddr) || 2038 ipv4_is_zeronet(fl4->saddr)) 2039 goto out; 2040 2041 /* I removed check for oif == dev_out->oif here. 2042 It was wrong for two reasons: 2043 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2044 is assigned to multiple interfaces. 2045 2. Moreover, we are allowed to send packets with saddr 2046 of another iface. --ANK 2047 */ 2048 2049 if (fl4->flowi4_oif == 0 && 2050 (ipv4_is_multicast(fl4->daddr) || 2051 ipv4_is_lbcast(fl4->daddr))) { 2052 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2053 dev_out = __ip_dev_find(net, fl4->saddr, false); 2054 if (!dev_out) 2055 goto out; 2056 2057 /* Special hack: user can direct multicasts 2058 and limited broadcast via necessary interface 2059 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2060 This hack is not just for fun, it allows 2061 vic,vat and friends to work. 2062 They bind socket to loopback, set ttl to zero 2063 and expect that it will work. 2064 From the viewpoint of routing cache they are broken, 2065 because we are not allowed to build multicast path 2066 with loopback source addr (look, routing cache 2067 cannot know, that ttl is zero, so that packet 2068 will not leave this host and route is valid). 2069 Luckily, this hack is good workaround. 2070 */ 2071 2072 fl4->flowi4_oif = dev_out->ifindex; 2073 goto make_route; 2074 } 2075 2076 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2077 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2078 if (!__ip_dev_find(net, fl4->saddr, false)) 2079 goto out; 2080 } 2081 } 2082 2083 2084 if (fl4->flowi4_oif) { 2085 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2086 rth = ERR_PTR(-ENODEV); 2087 if (!dev_out) 2088 goto out; 2089 2090 /* RACE: Check return value of inet_select_addr instead. */ 2091 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2092 rth = ERR_PTR(-ENETUNREACH); 2093 goto out; 2094 } 2095 if (ipv4_is_local_multicast(fl4->daddr) || 2096 ipv4_is_lbcast(fl4->daddr)) { 2097 if (!fl4->saddr) 2098 fl4->saddr = inet_select_addr(dev_out, 0, 2099 RT_SCOPE_LINK); 2100 goto make_route; 2101 } 2102 if (!fl4->saddr) { 2103 if (ipv4_is_multicast(fl4->daddr)) 2104 fl4->saddr = inet_select_addr(dev_out, 0, 2105 fl4->flowi4_scope); 2106 else if (!fl4->daddr) 2107 fl4->saddr = inet_select_addr(dev_out, 0, 2108 RT_SCOPE_HOST); 2109 } 2110 } 2111 2112 if (!fl4->daddr) { 2113 fl4->daddr = fl4->saddr; 2114 if (!fl4->daddr) 2115 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2116 dev_out = net->loopback_dev; 2117 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2118 res.type = RTN_LOCAL; 2119 flags |= RTCF_LOCAL; 2120 goto make_route; 2121 } 2122 2123 if (fib_lookup(net, fl4, &res)) { 2124 res.fi = NULL; 2125 res.table = NULL; 2126 if (fl4->flowi4_oif) { 2127 /* Apparently, routing tables are wrong. Assume, 2128 that the destination is on link. 2129 2130 WHY? DW. 2131 Because we are allowed to send to iface 2132 even if it has NO routes and NO assigned 2133 addresses. When oif is specified, routing 2134 tables are looked up with only one purpose: 2135 to catch if destination is gatewayed, rather than 2136 direct. Moreover, if MSG_DONTROUTE is set, 2137 we send packet, ignoring both routing tables 2138 and ifaddr state. --ANK 2139 2140 2141 We could make it even if oif is unknown, 2142 likely IPv6, but we do not. 2143 */ 2144 2145 if (fl4->saddr == 0) 2146 fl4->saddr = inet_select_addr(dev_out, 0, 2147 RT_SCOPE_LINK); 2148 res.type = RTN_UNICAST; 2149 goto make_route; 2150 } 2151 rth = ERR_PTR(-ENETUNREACH); 2152 goto out; 2153 } 2154 2155 if (res.type == RTN_LOCAL) { 2156 if (!fl4->saddr) { 2157 if (res.fi->fib_prefsrc) 2158 fl4->saddr = res.fi->fib_prefsrc; 2159 else 2160 fl4->saddr = fl4->daddr; 2161 } 2162 dev_out = net->loopback_dev; 2163 fl4->flowi4_oif = dev_out->ifindex; 2164 flags |= RTCF_LOCAL; 2165 goto make_route; 2166 } 2167 2168 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2169 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2170 fib_select_multipath(&res); 2171 else 2172 #endif 2173 if (!res.prefixlen && 2174 res.table->tb_num_default > 1 && 2175 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2176 fib_select_default(&res); 2177 2178 if (!fl4->saddr) 2179 fl4->saddr = FIB_RES_PREFSRC(net, res); 2180 2181 dev_out = FIB_RES_DEV(res); 2182 fl4->flowi4_oif = dev_out->ifindex; 2183 2184 2185 make_route: 2186 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2187 2188 out: 2189 rcu_read_unlock(); 2190 return rth; 2191 } 2192 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2193 2194 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2195 { 2196 return NULL; 2197 } 2198 2199 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2200 { 2201 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2202 2203 return mtu ? : dst->dev->mtu; 2204 } 2205 2206 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2207 struct sk_buff *skb, u32 mtu) 2208 { 2209 } 2210 2211 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2212 struct sk_buff *skb) 2213 { 2214 } 2215 2216 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2217 unsigned long old) 2218 { 2219 return NULL; 2220 } 2221 2222 static struct dst_ops ipv4_dst_blackhole_ops = { 2223 .family = AF_INET, 2224 .check = ipv4_blackhole_dst_check, 2225 .mtu = ipv4_blackhole_mtu, 2226 .default_advmss = ipv4_default_advmss, 2227 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2228 .redirect = ipv4_rt_blackhole_redirect, 2229 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2230 .neigh_lookup = ipv4_neigh_lookup, 2231 }; 2232 2233 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2234 { 2235 struct rtable *ort = (struct rtable *) dst_orig; 2236 struct rtable *rt; 2237 2238 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2239 if (rt) { 2240 struct dst_entry *new = &rt->dst; 2241 2242 new->__use = 1; 2243 new->input = dst_discard; 2244 new->output = dst_discard_sk; 2245 2246 new->dev = ort->dst.dev; 2247 if (new->dev) 2248 dev_hold(new->dev); 2249 2250 rt->rt_is_input = ort->rt_is_input; 2251 rt->rt_iif = ort->rt_iif; 2252 rt->rt_pmtu = ort->rt_pmtu; 2253 2254 rt->rt_genid = rt_genid_ipv4(net); 2255 rt->rt_flags = ort->rt_flags; 2256 rt->rt_type = ort->rt_type; 2257 rt->rt_gateway = ort->rt_gateway; 2258 rt->rt_uses_gateway = ort->rt_uses_gateway; 2259 2260 INIT_LIST_HEAD(&rt->rt_uncached); 2261 2262 dst_free(new); 2263 } 2264 2265 dst_release(dst_orig); 2266 2267 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2268 } 2269 2270 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2271 struct sock *sk) 2272 { 2273 struct rtable *rt = __ip_route_output_key(net, flp4); 2274 2275 if (IS_ERR(rt)) 2276 return rt; 2277 2278 if (flp4->flowi4_proto) 2279 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2280 flowi4_to_flowi(flp4), 2281 sk, 0); 2282 2283 return rt; 2284 } 2285 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2286 2287 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2288 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2289 u32 seq, int event, int nowait, unsigned int flags) 2290 { 2291 struct rtable *rt = skb_rtable(skb); 2292 struct rtmsg *r; 2293 struct nlmsghdr *nlh; 2294 unsigned long expires = 0; 2295 u32 error; 2296 u32 metrics[RTAX_MAX]; 2297 2298 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2299 if (!nlh) 2300 return -EMSGSIZE; 2301 2302 r = nlmsg_data(nlh); 2303 r->rtm_family = AF_INET; 2304 r->rtm_dst_len = 32; 2305 r->rtm_src_len = 0; 2306 r->rtm_tos = fl4->flowi4_tos; 2307 r->rtm_table = RT_TABLE_MAIN; 2308 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) 2309 goto nla_put_failure; 2310 r->rtm_type = rt->rt_type; 2311 r->rtm_scope = RT_SCOPE_UNIVERSE; 2312 r->rtm_protocol = RTPROT_UNSPEC; 2313 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2314 if (rt->rt_flags & RTCF_NOTIFY) 2315 r->rtm_flags |= RTM_F_NOTIFY; 2316 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2317 r->rtm_flags |= RTCF_DOREDIRECT; 2318 2319 if (nla_put_in_addr(skb, RTA_DST, dst)) 2320 goto nla_put_failure; 2321 if (src) { 2322 r->rtm_src_len = 32; 2323 if (nla_put_in_addr(skb, RTA_SRC, src)) 2324 goto nla_put_failure; 2325 } 2326 if (rt->dst.dev && 2327 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2328 goto nla_put_failure; 2329 #ifdef CONFIG_IP_ROUTE_CLASSID 2330 if (rt->dst.tclassid && 2331 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2332 goto nla_put_failure; 2333 #endif 2334 if (!rt_is_input_route(rt) && 2335 fl4->saddr != src) { 2336 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2337 goto nla_put_failure; 2338 } 2339 if (rt->rt_uses_gateway && 2340 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2341 goto nla_put_failure; 2342 2343 expires = rt->dst.expires; 2344 if (expires) { 2345 unsigned long now = jiffies; 2346 2347 if (time_before(now, expires)) 2348 expires -= now; 2349 else 2350 expires = 0; 2351 } 2352 2353 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2354 if (rt->rt_pmtu && expires) 2355 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2356 if (rtnetlink_put_metrics(skb, metrics) < 0) 2357 goto nla_put_failure; 2358 2359 if (fl4->flowi4_mark && 2360 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2361 goto nla_put_failure; 2362 2363 error = rt->dst.error; 2364 2365 if (rt_is_input_route(rt)) { 2366 #ifdef CONFIG_IP_MROUTE 2367 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2368 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2369 int err = ipmr_get_route(net, skb, 2370 fl4->saddr, fl4->daddr, 2371 r, nowait); 2372 if (err <= 0) { 2373 if (!nowait) { 2374 if (err == 0) 2375 return 0; 2376 goto nla_put_failure; 2377 } else { 2378 if (err == -EMSGSIZE) 2379 goto nla_put_failure; 2380 error = err; 2381 } 2382 } 2383 } else 2384 #endif 2385 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) 2386 goto nla_put_failure; 2387 } 2388 2389 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2390 goto nla_put_failure; 2391 2392 nlmsg_end(skb, nlh); 2393 return 0; 2394 2395 nla_put_failure: 2396 nlmsg_cancel(skb, nlh); 2397 return -EMSGSIZE; 2398 } 2399 2400 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 2401 { 2402 struct net *net = sock_net(in_skb->sk); 2403 struct rtmsg *rtm; 2404 struct nlattr *tb[RTA_MAX+1]; 2405 struct rtable *rt = NULL; 2406 struct flowi4 fl4; 2407 __be32 dst = 0; 2408 __be32 src = 0; 2409 u32 iif; 2410 int err; 2411 int mark; 2412 struct sk_buff *skb; 2413 2414 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2415 if (err < 0) 2416 goto errout; 2417 2418 rtm = nlmsg_data(nlh); 2419 2420 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2421 if (!skb) { 2422 err = -ENOBUFS; 2423 goto errout; 2424 } 2425 2426 /* Reserve room for dummy headers, this skb can pass 2427 through good chunk of routing engine. 2428 */ 2429 skb_reset_mac_header(skb); 2430 skb_reset_network_header(skb); 2431 2432 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2433 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2434 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2435 2436 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2437 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2438 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2439 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2440 2441 memset(&fl4, 0, sizeof(fl4)); 2442 fl4.daddr = dst; 2443 fl4.saddr = src; 2444 fl4.flowi4_tos = rtm->rtm_tos; 2445 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2446 fl4.flowi4_mark = mark; 2447 2448 if (iif) { 2449 struct net_device *dev; 2450 2451 dev = __dev_get_by_index(net, iif); 2452 if (!dev) { 2453 err = -ENODEV; 2454 goto errout_free; 2455 } 2456 2457 skb->protocol = htons(ETH_P_IP); 2458 skb->dev = dev; 2459 skb->mark = mark; 2460 local_bh_disable(); 2461 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2462 local_bh_enable(); 2463 2464 rt = skb_rtable(skb); 2465 if (err == 0 && rt->dst.error) 2466 err = -rt->dst.error; 2467 } else { 2468 rt = ip_route_output_key(net, &fl4); 2469 2470 err = 0; 2471 if (IS_ERR(rt)) 2472 err = PTR_ERR(rt); 2473 } 2474 2475 if (err) 2476 goto errout_free; 2477 2478 skb_dst_set(skb, &rt->dst); 2479 if (rtm->rtm_flags & RTM_F_NOTIFY) 2480 rt->rt_flags |= RTCF_NOTIFY; 2481 2482 err = rt_fill_info(net, dst, src, &fl4, skb, 2483 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2484 RTM_NEWROUTE, 0, 0); 2485 if (err < 0) 2486 goto errout_free; 2487 2488 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2489 errout: 2490 return err; 2491 2492 errout_free: 2493 kfree_skb(skb); 2494 goto errout; 2495 } 2496 2497 void ip_rt_multicast_event(struct in_device *in_dev) 2498 { 2499 rt_cache_flush(dev_net(in_dev->dev)); 2500 } 2501 2502 #ifdef CONFIG_SYSCTL 2503 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2504 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2505 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2506 static int ip_rt_gc_elasticity __read_mostly = 8; 2507 2508 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2509 void __user *buffer, 2510 size_t *lenp, loff_t *ppos) 2511 { 2512 struct net *net = (struct net *)__ctl->extra1; 2513 2514 if (write) { 2515 rt_cache_flush(net); 2516 fnhe_genid_bump(net); 2517 return 0; 2518 } 2519 2520 return -EINVAL; 2521 } 2522 2523 static struct ctl_table ipv4_route_table[] = { 2524 { 2525 .procname = "gc_thresh", 2526 .data = &ipv4_dst_ops.gc_thresh, 2527 .maxlen = sizeof(int), 2528 .mode = 0644, 2529 .proc_handler = proc_dointvec, 2530 }, 2531 { 2532 .procname = "max_size", 2533 .data = &ip_rt_max_size, 2534 .maxlen = sizeof(int), 2535 .mode = 0644, 2536 .proc_handler = proc_dointvec, 2537 }, 2538 { 2539 /* Deprecated. Use gc_min_interval_ms */ 2540 2541 .procname = "gc_min_interval", 2542 .data = &ip_rt_gc_min_interval, 2543 .maxlen = sizeof(int), 2544 .mode = 0644, 2545 .proc_handler = proc_dointvec_jiffies, 2546 }, 2547 { 2548 .procname = "gc_min_interval_ms", 2549 .data = &ip_rt_gc_min_interval, 2550 .maxlen = sizeof(int), 2551 .mode = 0644, 2552 .proc_handler = proc_dointvec_ms_jiffies, 2553 }, 2554 { 2555 .procname = "gc_timeout", 2556 .data = &ip_rt_gc_timeout, 2557 .maxlen = sizeof(int), 2558 .mode = 0644, 2559 .proc_handler = proc_dointvec_jiffies, 2560 }, 2561 { 2562 .procname = "gc_interval", 2563 .data = &ip_rt_gc_interval, 2564 .maxlen = sizeof(int), 2565 .mode = 0644, 2566 .proc_handler = proc_dointvec_jiffies, 2567 }, 2568 { 2569 .procname = "redirect_load", 2570 .data = &ip_rt_redirect_load, 2571 .maxlen = sizeof(int), 2572 .mode = 0644, 2573 .proc_handler = proc_dointvec, 2574 }, 2575 { 2576 .procname = "redirect_number", 2577 .data = &ip_rt_redirect_number, 2578 .maxlen = sizeof(int), 2579 .mode = 0644, 2580 .proc_handler = proc_dointvec, 2581 }, 2582 { 2583 .procname = "redirect_silence", 2584 .data = &ip_rt_redirect_silence, 2585 .maxlen = sizeof(int), 2586 .mode = 0644, 2587 .proc_handler = proc_dointvec, 2588 }, 2589 { 2590 .procname = "error_cost", 2591 .data = &ip_rt_error_cost, 2592 .maxlen = sizeof(int), 2593 .mode = 0644, 2594 .proc_handler = proc_dointvec, 2595 }, 2596 { 2597 .procname = "error_burst", 2598 .data = &ip_rt_error_burst, 2599 .maxlen = sizeof(int), 2600 .mode = 0644, 2601 .proc_handler = proc_dointvec, 2602 }, 2603 { 2604 .procname = "gc_elasticity", 2605 .data = &ip_rt_gc_elasticity, 2606 .maxlen = sizeof(int), 2607 .mode = 0644, 2608 .proc_handler = proc_dointvec, 2609 }, 2610 { 2611 .procname = "mtu_expires", 2612 .data = &ip_rt_mtu_expires, 2613 .maxlen = sizeof(int), 2614 .mode = 0644, 2615 .proc_handler = proc_dointvec_jiffies, 2616 }, 2617 { 2618 .procname = "min_pmtu", 2619 .data = &ip_rt_min_pmtu, 2620 .maxlen = sizeof(int), 2621 .mode = 0644, 2622 .proc_handler = proc_dointvec, 2623 }, 2624 { 2625 .procname = "min_adv_mss", 2626 .data = &ip_rt_min_advmss, 2627 .maxlen = sizeof(int), 2628 .mode = 0644, 2629 .proc_handler = proc_dointvec, 2630 }, 2631 { } 2632 }; 2633 2634 static struct ctl_table ipv4_route_flush_table[] = { 2635 { 2636 .procname = "flush", 2637 .maxlen = sizeof(int), 2638 .mode = 0200, 2639 .proc_handler = ipv4_sysctl_rtcache_flush, 2640 }, 2641 { }, 2642 }; 2643 2644 static __net_init int sysctl_route_net_init(struct net *net) 2645 { 2646 struct ctl_table *tbl; 2647 2648 tbl = ipv4_route_flush_table; 2649 if (!net_eq(net, &init_net)) { 2650 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2651 if (!tbl) 2652 goto err_dup; 2653 2654 /* Don't export sysctls to unprivileged users */ 2655 if (net->user_ns != &init_user_ns) 2656 tbl[0].procname = NULL; 2657 } 2658 tbl[0].extra1 = net; 2659 2660 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2661 if (!net->ipv4.route_hdr) 2662 goto err_reg; 2663 return 0; 2664 2665 err_reg: 2666 if (tbl != ipv4_route_flush_table) 2667 kfree(tbl); 2668 err_dup: 2669 return -ENOMEM; 2670 } 2671 2672 static __net_exit void sysctl_route_net_exit(struct net *net) 2673 { 2674 struct ctl_table *tbl; 2675 2676 tbl = net->ipv4.route_hdr->ctl_table_arg; 2677 unregister_net_sysctl_table(net->ipv4.route_hdr); 2678 BUG_ON(tbl == ipv4_route_flush_table); 2679 kfree(tbl); 2680 } 2681 2682 static __net_initdata struct pernet_operations sysctl_route_ops = { 2683 .init = sysctl_route_net_init, 2684 .exit = sysctl_route_net_exit, 2685 }; 2686 #endif 2687 2688 static __net_init int rt_genid_init(struct net *net) 2689 { 2690 atomic_set(&net->ipv4.rt_genid, 0); 2691 atomic_set(&net->fnhe_genid, 0); 2692 get_random_bytes(&net->ipv4.dev_addr_genid, 2693 sizeof(net->ipv4.dev_addr_genid)); 2694 return 0; 2695 } 2696 2697 static __net_initdata struct pernet_operations rt_genid_ops = { 2698 .init = rt_genid_init, 2699 }; 2700 2701 static int __net_init ipv4_inetpeer_init(struct net *net) 2702 { 2703 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2704 2705 if (!bp) 2706 return -ENOMEM; 2707 inet_peer_base_init(bp); 2708 net->ipv4.peers = bp; 2709 return 0; 2710 } 2711 2712 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2713 { 2714 struct inet_peer_base *bp = net->ipv4.peers; 2715 2716 net->ipv4.peers = NULL; 2717 inetpeer_invalidate_tree(bp); 2718 kfree(bp); 2719 } 2720 2721 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2722 .init = ipv4_inetpeer_init, 2723 .exit = ipv4_inetpeer_exit, 2724 }; 2725 2726 #ifdef CONFIG_IP_ROUTE_CLASSID 2727 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2728 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2729 2730 int __init ip_rt_init(void) 2731 { 2732 int rc = 0; 2733 int cpu; 2734 2735 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); 2736 if (!ip_idents) 2737 panic("IP: failed to allocate ip_idents\n"); 2738 2739 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 2740 2741 for_each_possible_cpu(cpu) { 2742 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 2743 2744 INIT_LIST_HEAD(&ul->head); 2745 spin_lock_init(&ul->lock); 2746 } 2747 #ifdef CONFIG_IP_ROUTE_CLASSID 2748 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2749 if (!ip_rt_acct) 2750 panic("IP: failed to allocate ip_rt_acct\n"); 2751 #endif 2752 2753 ipv4_dst_ops.kmem_cachep = 2754 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2755 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2756 2757 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2758 2759 if (dst_entries_init(&ipv4_dst_ops) < 0) 2760 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2761 2762 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2763 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2764 2765 ipv4_dst_ops.gc_thresh = ~0; 2766 ip_rt_max_size = INT_MAX; 2767 2768 devinet_init(); 2769 ip_fib_init(); 2770 2771 if (ip_rt_proc_init()) 2772 pr_err("Unable to create route proc files\n"); 2773 #ifdef CONFIG_XFRM 2774 xfrm_init(); 2775 xfrm4_init(); 2776 #endif 2777 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2778 2779 #ifdef CONFIG_SYSCTL 2780 register_pernet_subsys(&sysctl_route_ops); 2781 #endif 2782 register_pernet_subsys(&rt_genid_ops); 2783 register_pernet_subsys(&ipv4_inetpeer_ops); 2784 return rc; 2785 } 2786 2787 #ifdef CONFIG_SYSCTL 2788 /* 2789 * We really need to sanitize the damn ipv4 init order, then all 2790 * this nonsense will go away. 2791 */ 2792 void __init ip_static_sysctl_init(void) 2793 { 2794 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2795 } 2796 #endif 2797