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 /* IP on this device is disabled. */ 906 if (!in_dev) 907 goto out; 908 909 net = dev_net(rt->dst.dev); 910 if (!IN_DEV_FORWARD(in_dev)) { 911 switch (rt->dst.error) { 912 case EHOSTUNREACH: 913 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); 914 break; 915 916 case ENETUNREACH: 917 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 918 break; 919 } 920 goto out; 921 } 922 923 switch (rt->dst.error) { 924 case EINVAL: 925 default: 926 goto out; 927 case EHOSTUNREACH: 928 code = ICMP_HOST_UNREACH; 929 break; 930 case ENETUNREACH: 931 code = ICMP_NET_UNREACH; 932 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 933 break; 934 case EACCES: 935 code = ICMP_PKT_FILTERED; 936 break; 937 } 938 939 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 940 941 send = true; 942 if (peer) { 943 now = jiffies; 944 peer->rate_tokens += now - peer->rate_last; 945 if (peer->rate_tokens > ip_rt_error_burst) 946 peer->rate_tokens = ip_rt_error_burst; 947 peer->rate_last = now; 948 if (peer->rate_tokens >= ip_rt_error_cost) 949 peer->rate_tokens -= ip_rt_error_cost; 950 else 951 send = false; 952 inet_putpeer(peer); 953 } 954 if (send) 955 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 956 957 out: kfree_skb(skb); 958 return 0; 959 } 960 961 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 962 { 963 struct dst_entry *dst = &rt->dst; 964 struct fib_result res; 965 966 if (dst_metric_locked(dst, RTAX_MTU)) 967 return; 968 969 if (ipv4_mtu(dst) < mtu) 970 return; 971 972 if (mtu < ip_rt_min_pmtu) 973 mtu = ip_rt_min_pmtu; 974 975 if (rt->rt_pmtu == mtu && 976 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 977 return; 978 979 rcu_read_lock(); 980 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) { 981 struct fib_nh *nh = &FIB_RES_NH(res); 982 983 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, 984 jiffies + ip_rt_mtu_expires); 985 } 986 rcu_read_unlock(); 987 } 988 989 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 990 struct sk_buff *skb, u32 mtu) 991 { 992 struct rtable *rt = (struct rtable *) dst; 993 struct flowi4 fl4; 994 995 ip_rt_build_flow_key(&fl4, sk, skb); 996 __ip_rt_update_pmtu(rt, &fl4, mtu); 997 } 998 999 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1000 int oif, u32 mark, u8 protocol, int flow_flags) 1001 { 1002 const struct iphdr *iph = (const struct iphdr *) skb->data; 1003 struct flowi4 fl4; 1004 struct rtable *rt; 1005 1006 if (!mark) 1007 mark = IP4_REPLY_MARK(net, skb->mark); 1008 1009 __build_flow_key(&fl4, NULL, iph, oif, 1010 RT_TOS(iph->tos), protocol, mark, flow_flags); 1011 rt = __ip_route_output_key(net, &fl4); 1012 if (!IS_ERR(rt)) { 1013 __ip_rt_update_pmtu(rt, &fl4, mtu); 1014 ip_rt_put(rt); 1015 } 1016 } 1017 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1018 1019 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1020 { 1021 const struct iphdr *iph = (const struct iphdr *) skb->data; 1022 struct flowi4 fl4; 1023 struct rtable *rt; 1024 1025 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1026 1027 if (!fl4.flowi4_mark) 1028 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1029 1030 rt = __ip_route_output_key(sock_net(sk), &fl4); 1031 if (!IS_ERR(rt)) { 1032 __ip_rt_update_pmtu(rt, &fl4, mtu); 1033 ip_rt_put(rt); 1034 } 1035 } 1036 1037 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1038 { 1039 const struct iphdr *iph = (const struct iphdr *) skb->data; 1040 struct flowi4 fl4; 1041 struct rtable *rt; 1042 struct dst_entry *odst = NULL; 1043 bool new = false; 1044 1045 bh_lock_sock(sk); 1046 1047 if (!ip_sk_accept_pmtu(sk)) 1048 goto out; 1049 1050 odst = sk_dst_get(sk); 1051 1052 if (sock_owned_by_user(sk) || !odst) { 1053 __ipv4_sk_update_pmtu(skb, sk, mtu); 1054 goto out; 1055 } 1056 1057 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1058 1059 rt = (struct rtable *)odst; 1060 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1061 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1062 if (IS_ERR(rt)) 1063 goto out; 1064 1065 new = true; 1066 } 1067 1068 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); 1069 1070 if (!dst_check(&rt->dst, 0)) { 1071 if (new) 1072 dst_release(&rt->dst); 1073 1074 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1075 if (IS_ERR(rt)) 1076 goto out; 1077 1078 new = true; 1079 } 1080 1081 if (new) 1082 sk_dst_set(sk, &rt->dst); 1083 1084 out: 1085 bh_unlock_sock(sk); 1086 dst_release(odst); 1087 } 1088 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1089 1090 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1091 int oif, u32 mark, u8 protocol, int flow_flags) 1092 { 1093 const struct iphdr *iph = (const struct iphdr *) skb->data; 1094 struct flowi4 fl4; 1095 struct rtable *rt; 1096 1097 __build_flow_key(&fl4, NULL, iph, oif, 1098 RT_TOS(iph->tos), protocol, mark, flow_flags); 1099 rt = __ip_route_output_key(net, &fl4); 1100 if (!IS_ERR(rt)) { 1101 __ip_do_redirect(rt, skb, &fl4, false); 1102 ip_rt_put(rt); 1103 } 1104 } 1105 EXPORT_SYMBOL_GPL(ipv4_redirect); 1106 1107 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1108 { 1109 const struct iphdr *iph = (const struct iphdr *) skb->data; 1110 struct flowi4 fl4; 1111 struct rtable *rt; 1112 1113 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1114 rt = __ip_route_output_key(sock_net(sk), &fl4); 1115 if (!IS_ERR(rt)) { 1116 __ip_do_redirect(rt, skb, &fl4, false); 1117 ip_rt_put(rt); 1118 } 1119 } 1120 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1121 1122 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1123 { 1124 struct rtable *rt = (struct rtable *) dst; 1125 1126 /* All IPV4 dsts are created with ->obsolete set to the value 1127 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1128 * into this function always. 1129 * 1130 * When a PMTU/redirect information update invalidates a route, 1131 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1132 * DST_OBSOLETE_DEAD by dst_free(). 1133 */ 1134 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1135 return NULL; 1136 return dst; 1137 } 1138 1139 static void ipv4_link_failure(struct sk_buff *skb) 1140 { 1141 struct rtable *rt; 1142 1143 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1144 1145 rt = skb_rtable(skb); 1146 if (rt) 1147 dst_set_expires(&rt->dst, 0); 1148 } 1149 1150 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb) 1151 { 1152 pr_debug("%s: %pI4 -> %pI4, %s\n", 1153 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1154 skb->dev ? skb->dev->name : "?"); 1155 kfree_skb(skb); 1156 WARN_ON(1); 1157 return 0; 1158 } 1159 1160 /* 1161 We do not cache source address of outgoing interface, 1162 because it is used only by IP RR, TS and SRR options, 1163 so that it out of fast path. 1164 1165 BTW remember: "addr" is allowed to be not aligned 1166 in IP options! 1167 */ 1168 1169 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1170 { 1171 __be32 src; 1172 1173 if (rt_is_output_route(rt)) 1174 src = ip_hdr(skb)->saddr; 1175 else { 1176 struct fib_result res; 1177 struct flowi4 fl4; 1178 struct iphdr *iph; 1179 1180 iph = ip_hdr(skb); 1181 1182 memset(&fl4, 0, sizeof(fl4)); 1183 fl4.daddr = iph->daddr; 1184 fl4.saddr = iph->saddr; 1185 fl4.flowi4_tos = RT_TOS(iph->tos); 1186 fl4.flowi4_oif = rt->dst.dev->ifindex; 1187 fl4.flowi4_iif = skb->dev->ifindex; 1188 fl4.flowi4_mark = skb->mark; 1189 1190 rcu_read_lock(); 1191 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1192 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1193 else 1194 src = inet_select_addr(rt->dst.dev, 1195 rt_nexthop(rt, iph->daddr), 1196 RT_SCOPE_UNIVERSE); 1197 rcu_read_unlock(); 1198 } 1199 memcpy(addr, &src, 4); 1200 } 1201 1202 #ifdef CONFIG_IP_ROUTE_CLASSID 1203 static void set_class_tag(struct rtable *rt, u32 tag) 1204 { 1205 if (!(rt->dst.tclassid & 0xFFFF)) 1206 rt->dst.tclassid |= tag & 0xFFFF; 1207 if (!(rt->dst.tclassid & 0xFFFF0000)) 1208 rt->dst.tclassid |= tag & 0xFFFF0000; 1209 } 1210 #endif 1211 1212 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1213 { 1214 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1215 1216 if (advmss == 0) { 1217 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1218 ip_rt_min_advmss); 1219 if (advmss > 65535 - 40) 1220 advmss = 65535 - 40; 1221 } 1222 return advmss; 1223 } 1224 1225 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1226 { 1227 const struct rtable *rt = (const struct rtable *) dst; 1228 unsigned int mtu = rt->rt_pmtu; 1229 1230 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1231 mtu = dst_metric_raw(dst, RTAX_MTU); 1232 1233 if (mtu) 1234 return mtu; 1235 1236 mtu = dst->dev->mtu; 1237 1238 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1239 if (rt->rt_uses_gateway && mtu > 576) 1240 mtu = 576; 1241 } 1242 1243 return min_t(unsigned int, mtu, IP_MAX_MTU); 1244 } 1245 1246 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1247 { 1248 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1249 struct fib_nh_exception *fnhe; 1250 u32 hval; 1251 1252 if (!hash) 1253 return NULL; 1254 1255 hval = fnhe_hashfun(daddr); 1256 1257 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1258 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1259 if (fnhe->fnhe_daddr == daddr) 1260 return fnhe; 1261 } 1262 return NULL; 1263 } 1264 1265 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1266 __be32 daddr) 1267 { 1268 bool ret = false; 1269 1270 spin_lock_bh(&fnhe_lock); 1271 1272 if (daddr == fnhe->fnhe_daddr) { 1273 struct rtable __rcu **porig; 1274 struct rtable *orig; 1275 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1276 1277 if (rt_is_input_route(rt)) 1278 porig = &fnhe->fnhe_rth_input; 1279 else 1280 porig = &fnhe->fnhe_rth_output; 1281 orig = rcu_dereference(*porig); 1282 1283 if (fnhe->fnhe_genid != genid) { 1284 fnhe->fnhe_genid = genid; 1285 fnhe->fnhe_gw = 0; 1286 fnhe->fnhe_pmtu = 0; 1287 fnhe->fnhe_expires = 0; 1288 fnhe_flush_routes(fnhe); 1289 orig = NULL; 1290 } 1291 fill_route_from_fnhe(rt, fnhe); 1292 if (!rt->rt_gateway) 1293 rt->rt_gateway = daddr; 1294 1295 if (!(rt->dst.flags & DST_NOCACHE)) { 1296 rcu_assign_pointer(*porig, rt); 1297 if (orig) 1298 rt_free(orig); 1299 ret = true; 1300 } 1301 1302 fnhe->fnhe_stamp = jiffies; 1303 } 1304 spin_unlock_bh(&fnhe_lock); 1305 1306 return ret; 1307 } 1308 1309 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1310 { 1311 struct rtable *orig, *prev, **p; 1312 bool ret = true; 1313 1314 if (rt_is_input_route(rt)) { 1315 p = (struct rtable **)&nh->nh_rth_input; 1316 } else { 1317 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1318 } 1319 orig = *p; 1320 1321 prev = cmpxchg(p, orig, rt); 1322 if (prev == orig) { 1323 if (orig) 1324 rt_free(orig); 1325 } else 1326 ret = false; 1327 1328 return ret; 1329 } 1330 1331 struct uncached_list { 1332 spinlock_t lock; 1333 struct list_head head; 1334 }; 1335 1336 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1337 1338 static void rt_add_uncached_list(struct rtable *rt) 1339 { 1340 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1341 1342 rt->rt_uncached_list = ul; 1343 1344 spin_lock_bh(&ul->lock); 1345 list_add_tail(&rt->rt_uncached, &ul->head); 1346 spin_unlock_bh(&ul->lock); 1347 } 1348 1349 static void ipv4_dst_destroy(struct dst_entry *dst) 1350 { 1351 struct rtable *rt = (struct rtable *) dst; 1352 1353 if (!list_empty(&rt->rt_uncached)) { 1354 struct uncached_list *ul = rt->rt_uncached_list; 1355 1356 spin_lock_bh(&ul->lock); 1357 list_del(&rt->rt_uncached); 1358 spin_unlock_bh(&ul->lock); 1359 } 1360 } 1361 1362 void rt_flush_dev(struct net_device *dev) 1363 { 1364 struct net *net = dev_net(dev); 1365 struct rtable *rt; 1366 int cpu; 1367 1368 for_each_possible_cpu(cpu) { 1369 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1370 1371 spin_lock_bh(&ul->lock); 1372 list_for_each_entry(rt, &ul->head, rt_uncached) { 1373 if (rt->dst.dev != dev) 1374 continue; 1375 rt->dst.dev = net->loopback_dev; 1376 dev_hold(rt->dst.dev); 1377 dev_put(dev); 1378 } 1379 spin_unlock_bh(&ul->lock); 1380 } 1381 } 1382 1383 static bool rt_cache_valid(const struct rtable *rt) 1384 { 1385 return rt && 1386 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1387 !rt_is_expired(rt); 1388 } 1389 1390 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1391 const struct fib_result *res, 1392 struct fib_nh_exception *fnhe, 1393 struct fib_info *fi, u16 type, u32 itag) 1394 { 1395 bool cached = false; 1396 1397 if (fi) { 1398 struct fib_nh *nh = &FIB_RES_NH(*res); 1399 1400 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1401 rt->rt_gateway = nh->nh_gw; 1402 rt->rt_uses_gateway = 1; 1403 } 1404 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1405 #ifdef CONFIG_IP_ROUTE_CLASSID 1406 rt->dst.tclassid = nh->nh_tclassid; 1407 #endif 1408 if (unlikely(fnhe)) 1409 cached = rt_bind_exception(rt, fnhe, daddr); 1410 else if (!(rt->dst.flags & DST_NOCACHE)) 1411 cached = rt_cache_route(nh, rt); 1412 if (unlikely(!cached)) { 1413 /* Routes we intend to cache in nexthop exception or 1414 * FIB nexthop have the DST_NOCACHE bit clear. 1415 * However, if we are unsuccessful at storing this 1416 * route into the cache we really need to set it. 1417 */ 1418 rt->dst.flags |= DST_NOCACHE; 1419 if (!rt->rt_gateway) 1420 rt->rt_gateway = daddr; 1421 rt_add_uncached_list(rt); 1422 } 1423 } else 1424 rt_add_uncached_list(rt); 1425 1426 #ifdef CONFIG_IP_ROUTE_CLASSID 1427 #ifdef CONFIG_IP_MULTIPLE_TABLES 1428 set_class_tag(rt, res->tclassid); 1429 #endif 1430 set_class_tag(rt, itag); 1431 #endif 1432 } 1433 1434 static struct rtable *rt_dst_alloc(struct net_device *dev, 1435 bool nopolicy, bool noxfrm, bool will_cache) 1436 { 1437 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1438 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1439 (nopolicy ? DST_NOPOLICY : 0) | 1440 (noxfrm ? DST_NOXFRM : 0)); 1441 } 1442 1443 /* called in rcu_read_lock() section */ 1444 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1445 u8 tos, struct net_device *dev, int our) 1446 { 1447 struct rtable *rth; 1448 struct in_device *in_dev = __in_dev_get_rcu(dev); 1449 u32 itag = 0; 1450 int err; 1451 1452 /* Primary sanity checks. */ 1453 1454 if (!in_dev) 1455 return -EINVAL; 1456 1457 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1458 skb->protocol != htons(ETH_P_IP)) 1459 goto e_inval; 1460 1461 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1462 if (ipv4_is_loopback(saddr)) 1463 goto e_inval; 1464 1465 if (ipv4_is_zeronet(saddr)) { 1466 if (!ipv4_is_local_multicast(daddr)) 1467 goto e_inval; 1468 } else { 1469 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1470 in_dev, &itag); 1471 if (err < 0) 1472 goto e_err; 1473 } 1474 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, 1475 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1476 if (!rth) 1477 goto e_nobufs; 1478 1479 #ifdef CONFIG_IP_ROUTE_CLASSID 1480 rth->dst.tclassid = itag; 1481 #endif 1482 rth->dst.output = ip_rt_bug; 1483 1484 rth->rt_genid = rt_genid_ipv4(dev_net(dev)); 1485 rth->rt_flags = RTCF_MULTICAST; 1486 rth->rt_type = RTN_MULTICAST; 1487 rth->rt_is_input= 1; 1488 rth->rt_iif = 0; 1489 rth->rt_pmtu = 0; 1490 rth->rt_gateway = 0; 1491 rth->rt_uses_gateway = 0; 1492 INIT_LIST_HEAD(&rth->rt_uncached); 1493 if (our) { 1494 rth->dst.input= ip_local_deliver; 1495 rth->rt_flags |= RTCF_LOCAL; 1496 } 1497 1498 #ifdef CONFIG_IP_MROUTE 1499 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1500 rth->dst.input = ip_mr_input; 1501 #endif 1502 RT_CACHE_STAT_INC(in_slow_mc); 1503 1504 skb_dst_set(skb, &rth->dst); 1505 return 0; 1506 1507 e_nobufs: 1508 return -ENOBUFS; 1509 e_inval: 1510 return -EINVAL; 1511 e_err: 1512 return err; 1513 } 1514 1515 1516 static void ip_handle_martian_source(struct net_device *dev, 1517 struct in_device *in_dev, 1518 struct sk_buff *skb, 1519 __be32 daddr, 1520 __be32 saddr) 1521 { 1522 RT_CACHE_STAT_INC(in_martian_src); 1523 #ifdef CONFIG_IP_ROUTE_VERBOSE 1524 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1525 /* 1526 * RFC1812 recommendation, if source is martian, 1527 * the only hint is MAC header. 1528 */ 1529 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1530 &daddr, &saddr, dev->name); 1531 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1532 print_hex_dump(KERN_WARNING, "ll header: ", 1533 DUMP_PREFIX_OFFSET, 16, 1, 1534 skb_mac_header(skb), 1535 dev->hard_header_len, true); 1536 } 1537 } 1538 #endif 1539 } 1540 1541 /* called in rcu_read_lock() section */ 1542 static int __mkroute_input(struct sk_buff *skb, 1543 const struct fib_result *res, 1544 struct in_device *in_dev, 1545 __be32 daddr, __be32 saddr, u32 tos) 1546 { 1547 struct fib_nh_exception *fnhe; 1548 struct rtable *rth; 1549 int err; 1550 struct in_device *out_dev; 1551 unsigned int flags = 0; 1552 bool do_cache; 1553 u32 itag = 0; 1554 1555 /* get a working reference to the output device */ 1556 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1557 if (!out_dev) { 1558 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1559 return -EINVAL; 1560 } 1561 1562 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1563 in_dev->dev, in_dev, &itag); 1564 if (err < 0) { 1565 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1566 saddr); 1567 1568 goto cleanup; 1569 } 1570 1571 do_cache = res->fi && !itag; 1572 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1573 skb->protocol == htons(ETH_P_IP) && 1574 (IN_DEV_SHARED_MEDIA(out_dev) || 1575 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1576 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1577 1578 if (skb->protocol != htons(ETH_P_IP)) { 1579 /* Not IP (i.e. ARP). Do not create route, if it is 1580 * invalid for proxy arp. DNAT routes are always valid. 1581 * 1582 * Proxy arp feature have been extended to allow, ARP 1583 * replies back to the same interface, to support 1584 * Private VLAN switch technologies. See arp.c. 1585 */ 1586 if (out_dev == in_dev && 1587 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1588 err = -EINVAL; 1589 goto cleanup; 1590 } 1591 } 1592 1593 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1594 if (do_cache) { 1595 if (fnhe) 1596 rth = rcu_dereference(fnhe->fnhe_rth_input); 1597 else 1598 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1599 1600 if (rt_cache_valid(rth)) { 1601 skb_dst_set_noref(skb, &rth->dst); 1602 goto out; 1603 } 1604 } 1605 1606 rth = rt_dst_alloc(out_dev->dev, 1607 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1608 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1609 if (!rth) { 1610 err = -ENOBUFS; 1611 goto cleanup; 1612 } 1613 1614 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev)); 1615 rth->rt_flags = flags; 1616 rth->rt_type = res->type; 1617 rth->rt_is_input = 1; 1618 rth->rt_iif = 0; 1619 rth->rt_pmtu = 0; 1620 rth->rt_gateway = 0; 1621 rth->rt_uses_gateway = 0; 1622 INIT_LIST_HEAD(&rth->rt_uncached); 1623 RT_CACHE_STAT_INC(in_slow_tot); 1624 1625 rth->dst.input = ip_forward; 1626 rth->dst.output = ip_output; 1627 1628 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); 1629 skb_dst_set(skb, &rth->dst); 1630 out: 1631 err = 0; 1632 cleanup: 1633 return err; 1634 } 1635 1636 static int ip_mkroute_input(struct sk_buff *skb, 1637 struct fib_result *res, 1638 const struct flowi4 *fl4, 1639 struct in_device *in_dev, 1640 __be32 daddr, __be32 saddr, u32 tos) 1641 { 1642 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1643 if (res->fi && res->fi->fib_nhs > 1) 1644 fib_select_multipath(res); 1645 #endif 1646 1647 /* create a routing cache entry */ 1648 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1649 } 1650 1651 /* 1652 * NOTE. We drop all the packets that has local source 1653 * addresses, because every properly looped back packet 1654 * must have correct destination already attached by output routine. 1655 * 1656 * Such approach solves two big problems: 1657 * 1. Not simplex devices are handled properly. 1658 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1659 * called with rcu_read_lock() 1660 */ 1661 1662 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1663 u8 tos, struct net_device *dev) 1664 { 1665 struct fib_result res; 1666 struct in_device *in_dev = __in_dev_get_rcu(dev); 1667 struct flowi4 fl4; 1668 unsigned int flags = 0; 1669 u32 itag = 0; 1670 struct rtable *rth; 1671 int err = -EINVAL; 1672 struct net *net = dev_net(dev); 1673 bool do_cache; 1674 1675 /* IP on this device is disabled. */ 1676 1677 if (!in_dev) 1678 goto out; 1679 1680 /* Check for the most weird martians, which can be not detected 1681 by fib_lookup. 1682 */ 1683 1684 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1685 goto martian_source; 1686 1687 res.fi = NULL; 1688 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1689 goto brd_input; 1690 1691 /* Accept zero addresses only to limited broadcast; 1692 * I even do not know to fix it or not. Waiting for complains :-) 1693 */ 1694 if (ipv4_is_zeronet(saddr)) 1695 goto martian_source; 1696 1697 if (ipv4_is_zeronet(daddr)) 1698 goto martian_destination; 1699 1700 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1701 * and call it once if daddr or/and saddr are loopback addresses 1702 */ 1703 if (ipv4_is_loopback(daddr)) { 1704 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1705 goto martian_destination; 1706 } else if (ipv4_is_loopback(saddr)) { 1707 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1708 goto martian_source; 1709 } 1710 1711 /* 1712 * Now we are ready to route packet. 1713 */ 1714 fl4.flowi4_oif = 0; 1715 fl4.flowi4_iif = dev->ifindex; 1716 fl4.flowi4_mark = skb->mark; 1717 fl4.flowi4_tos = tos; 1718 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1719 fl4.daddr = daddr; 1720 fl4.saddr = saddr; 1721 err = fib_lookup(net, &fl4, &res); 1722 if (err != 0) { 1723 if (!IN_DEV_FORWARD(in_dev)) 1724 err = -EHOSTUNREACH; 1725 goto no_route; 1726 } 1727 1728 if (res.type == RTN_BROADCAST) 1729 goto brd_input; 1730 1731 if (res.type == RTN_LOCAL) { 1732 err = fib_validate_source(skb, saddr, daddr, tos, 1733 0, dev, in_dev, &itag); 1734 if (err < 0) 1735 goto martian_source_keep_err; 1736 goto local_input; 1737 } 1738 1739 if (!IN_DEV_FORWARD(in_dev)) { 1740 err = -EHOSTUNREACH; 1741 goto no_route; 1742 } 1743 if (res.type != RTN_UNICAST) 1744 goto martian_destination; 1745 1746 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1747 out: return err; 1748 1749 brd_input: 1750 if (skb->protocol != htons(ETH_P_IP)) 1751 goto e_inval; 1752 1753 if (!ipv4_is_zeronet(saddr)) { 1754 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1755 in_dev, &itag); 1756 if (err < 0) 1757 goto martian_source_keep_err; 1758 } 1759 flags |= RTCF_BROADCAST; 1760 res.type = RTN_BROADCAST; 1761 RT_CACHE_STAT_INC(in_brd); 1762 1763 local_input: 1764 do_cache = false; 1765 if (res.fi) { 1766 if (!itag) { 1767 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1768 if (rt_cache_valid(rth)) { 1769 skb_dst_set_noref(skb, &rth->dst); 1770 err = 0; 1771 goto out; 1772 } 1773 do_cache = true; 1774 } 1775 } 1776 1777 rth = rt_dst_alloc(net->loopback_dev, 1778 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1779 if (!rth) 1780 goto e_nobufs; 1781 1782 rth->dst.input= ip_local_deliver; 1783 rth->dst.output= ip_rt_bug; 1784 #ifdef CONFIG_IP_ROUTE_CLASSID 1785 rth->dst.tclassid = itag; 1786 #endif 1787 1788 rth->rt_genid = rt_genid_ipv4(net); 1789 rth->rt_flags = flags|RTCF_LOCAL; 1790 rth->rt_type = res.type; 1791 rth->rt_is_input = 1; 1792 rth->rt_iif = 0; 1793 rth->rt_pmtu = 0; 1794 rth->rt_gateway = 0; 1795 rth->rt_uses_gateway = 0; 1796 INIT_LIST_HEAD(&rth->rt_uncached); 1797 RT_CACHE_STAT_INC(in_slow_tot); 1798 if (res.type == RTN_UNREACHABLE) { 1799 rth->dst.input= ip_error; 1800 rth->dst.error= -err; 1801 rth->rt_flags &= ~RTCF_LOCAL; 1802 } 1803 if (do_cache) { 1804 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { 1805 rth->dst.flags |= DST_NOCACHE; 1806 rt_add_uncached_list(rth); 1807 } 1808 } 1809 skb_dst_set(skb, &rth->dst); 1810 err = 0; 1811 goto out; 1812 1813 no_route: 1814 RT_CACHE_STAT_INC(in_no_route); 1815 res.type = RTN_UNREACHABLE; 1816 res.fi = NULL; 1817 goto local_input; 1818 1819 /* 1820 * Do not cache martian addresses: they should be logged (RFC1812) 1821 */ 1822 martian_destination: 1823 RT_CACHE_STAT_INC(in_martian_dst); 1824 #ifdef CONFIG_IP_ROUTE_VERBOSE 1825 if (IN_DEV_LOG_MARTIANS(in_dev)) 1826 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1827 &daddr, &saddr, dev->name); 1828 #endif 1829 1830 e_inval: 1831 err = -EINVAL; 1832 goto out; 1833 1834 e_nobufs: 1835 err = -ENOBUFS; 1836 goto out; 1837 1838 martian_source: 1839 err = -EINVAL; 1840 martian_source_keep_err: 1841 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1842 goto out; 1843 } 1844 1845 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1846 u8 tos, struct net_device *dev) 1847 { 1848 int res; 1849 1850 rcu_read_lock(); 1851 1852 /* Multicast recognition logic is moved from route cache to here. 1853 The problem was that too many Ethernet cards have broken/missing 1854 hardware multicast filters :-( As result the host on multicasting 1855 network acquires a lot of useless route cache entries, sort of 1856 SDR messages from all the world. Now we try to get rid of them. 1857 Really, provided software IP multicast filter is organized 1858 reasonably (at least, hashed), it does not result in a slowdown 1859 comparing with route cache reject entries. 1860 Note, that multicast routers are not affected, because 1861 route cache entry is created eventually. 1862 */ 1863 if (ipv4_is_multicast(daddr)) { 1864 struct in_device *in_dev = __in_dev_get_rcu(dev); 1865 1866 if (in_dev) { 1867 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1868 ip_hdr(skb)->protocol); 1869 if (our 1870 #ifdef CONFIG_IP_MROUTE 1871 || 1872 (!ipv4_is_local_multicast(daddr) && 1873 IN_DEV_MFORWARD(in_dev)) 1874 #endif 1875 ) { 1876 int res = ip_route_input_mc(skb, daddr, saddr, 1877 tos, dev, our); 1878 rcu_read_unlock(); 1879 return res; 1880 } 1881 } 1882 rcu_read_unlock(); 1883 return -EINVAL; 1884 } 1885 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1886 rcu_read_unlock(); 1887 return res; 1888 } 1889 EXPORT_SYMBOL(ip_route_input_noref); 1890 1891 /* called with rcu_read_lock() */ 1892 static struct rtable *__mkroute_output(const struct fib_result *res, 1893 const struct flowi4 *fl4, int orig_oif, 1894 struct net_device *dev_out, 1895 unsigned int flags) 1896 { 1897 struct fib_info *fi = res->fi; 1898 struct fib_nh_exception *fnhe; 1899 struct in_device *in_dev; 1900 u16 type = res->type; 1901 struct rtable *rth; 1902 bool do_cache; 1903 1904 in_dev = __in_dev_get_rcu(dev_out); 1905 if (!in_dev) 1906 return ERR_PTR(-EINVAL); 1907 1908 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1909 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1910 return ERR_PTR(-EINVAL); 1911 1912 if (ipv4_is_lbcast(fl4->daddr)) 1913 type = RTN_BROADCAST; 1914 else if (ipv4_is_multicast(fl4->daddr)) 1915 type = RTN_MULTICAST; 1916 else if (ipv4_is_zeronet(fl4->daddr)) 1917 return ERR_PTR(-EINVAL); 1918 1919 if (dev_out->flags & IFF_LOOPBACK) 1920 flags |= RTCF_LOCAL; 1921 1922 do_cache = true; 1923 if (type == RTN_BROADCAST) { 1924 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1925 fi = NULL; 1926 } else if (type == RTN_MULTICAST) { 1927 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1928 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1929 fl4->flowi4_proto)) 1930 flags &= ~RTCF_LOCAL; 1931 else 1932 do_cache = false; 1933 /* If multicast route do not exist use 1934 * default one, but do not gateway in this case. 1935 * Yes, it is hack. 1936 */ 1937 if (fi && res->prefixlen < 4) 1938 fi = NULL; 1939 } 1940 1941 fnhe = NULL; 1942 do_cache &= fi != NULL; 1943 if (do_cache) { 1944 struct rtable __rcu **prth; 1945 struct fib_nh *nh = &FIB_RES_NH(*res); 1946 1947 fnhe = find_exception(nh, fl4->daddr); 1948 if (fnhe) 1949 prth = &fnhe->fnhe_rth_output; 1950 else { 1951 if (unlikely(fl4->flowi4_flags & 1952 FLOWI_FLAG_KNOWN_NH && 1953 !(nh->nh_gw && 1954 nh->nh_scope == RT_SCOPE_LINK))) { 1955 do_cache = false; 1956 goto add; 1957 } 1958 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 1959 } 1960 rth = rcu_dereference(*prth); 1961 if (rt_cache_valid(rth)) { 1962 dst_hold(&rth->dst); 1963 return rth; 1964 } 1965 } 1966 1967 add: 1968 rth = rt_dst_alloc(dev_out, 1969 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1970 IN_DEV_CONF_GET(in_dev, NOXFRM), 1971 do_cache); 1972 if (!rth) 1973 return ERR_PTR(-ENOBUFS); 1974 1975 rth->dst.output = ip_output; 1976 1977 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out)); 1978 rth->rt_flags = flags; 1979 rth->rt_type = type; 1980 rth->rt_is_input = 0; 1981 rth->rt_iif = orig_oif ? : 0; 1982 rth->rt_pmtu = 0; 1983 rth->rt_gateway = 0; 1984 rth->rt_uses_gateway = 0; 1985 INIT_LIST_HEAD(&rth->rt_uncached); 1986 1987 RT_CACHE_STAT_INC(out_slow_tot); 1988 1989 if (flags & RTCF_LOCAL) 1990 rth->dst.input = ip_local_deliver; 1991 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 1992 if (flags & RTCF_LOCAL && 1993 !(dev_out->flags & IFF_LOOPBACK)) { 1994 rth->dst.output = ip_mc_output; 1995 RT_CACHE_STAT_INC(out_slow_mc); 1996 } 1997 #ifdef CONFIG_IP_MROUTE 1998 if (type == RTN_MULTICAST) { 1999 if (IN_DEV_MFORWARD(in_dev) && 2000 !ipv4_is_local_multicast(fl4->daddr)) { 2001 rth->dst.input = ip_mr_input; 2002 rth->dst.output = ip_mc_output; 2003 } 2004 } 2005 #endif 2006 } 2007 2008 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 2009 2010 return rth; 2011 } 2012 2013 /* 2014 * Major route resolver routine. 2015 */ 2016 2017 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 2018 { 2019 struct net_device *dev_out = NULL; 2020 __u8 tos = RT_FL_TOS(fl4); 2021 unsigned int flags = 0; 2022 struct fib_result res; 2023 struct rtable *rth; 2024 int orig_oif; 2025 2026 res.tclassid = 0; 2027 res.fi = NULL; 2028 res.table = NULL; 2029 2030 orig_oif = fl4->flowi4_oif; 2031 2032 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2033 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2034 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2035 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2036 2037 rcu_read_lock(); 2038 if (fl4->saddr) { 2039 rth = ERR_PTR(-EINVAL); 2040 if (ipv4_is_multicast(fl4->saddr) || 2041 ipv4_is_lbcast(fl4->saddr) || 2042 ipv4_is_zeronet(fl4->saddr)) 2043 goto out; 2044 2045 /* I removed check for oif == dev_out->oif here. 2046 It was wrong for two reasons: 2047 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2048 is assigned to multiple interfaces. 2049 2. Moreover, we are allowed to send packets with saddr 2050 of another iface. --ANK 2051 */ 2052 2053 if (fl4->flowi4_oif == 0 && 2054 (ipv4_is_multicast(fl4->daddr) || 2055 ipv4_is_lbcast(fl4->daddr))) { 2056 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2057 dev_out = __ip_dev_find(net, fl4->saddr, false); 2058 if (!dev_out) 2059 goto out; 2060 2061 /* Special hack: user can direct multicasts 2062 and limited broadcast via necessary interface 2063 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2064 This hack is not just for fun, it allows 2065 vic,vat and friends to work. 2066 They bind socket to loopback, set ttl to zero 2067 and expect that it will work. 2068 From the viewpoint of routing cache they are broken, 2069 because we are not allowed to build multicast path 2070 with loopback source addr (look, routing cache 2071 cannot know, that ttl is zero, so that packet 2072 will not leave this host and route is valid). 2073 Luckily, this hack is good workaround. 2074 */ 2075 2076 fl4->flowi4_oif = dev_out->ifindex; 2077 goto make_route; 2078 } 2079 2080 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2081 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2082 if (!__ip_dev_find(net, fl4->saddr, false)) 2083 goto out; 2084 } 2085 } 2086 2087 2088 if (fl4->flowi4_oif) { 2089 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2090 rth = ERR_PTR(-ENODEV); 2091 if (!dev_out) 2092 goto out; 2093 2094 /* RACE: Check return value of inet_select_addr instead. */ 2095 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2096 rth = ERR_PTR(-ENETUNREACH); 2097 goto out; 2098 } 2099 if (ipv4_is_local_multicast(fl4->daddr) || 2100 ipv4_is_lbcast(fl4->daddr)) { 2101 if (!fl4->saddr) 2102 fl4->saddr = inet_select_addr(dev_out, 0, 2103 RT_SCOPE_LINK); 2104 goto make_route; 2105 } 2106 if (!fl4->saddr) { 2107 if (ipv4_is_multicast(fl4->daddr)) 2108 fl4->saddr = inet_select_addr(dev_out, 0, 2109 fl4->flowi4_scope); 2110 else if (!fl4->daddr) 2111 fl4->saddr = inet_select_addr(dev_out, 0, 2112 RT_SCOPE_HOST); 2113 } 2114 } 2115 2116 if (!fl4->daddr) { 2117 fl4->daddr = fl4->saddr; 2118 if (!fl4->daddr) 2119 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2120 dev_out = net->loopback_dev; 2121 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2122 res.type = RTN_LOCAL; 2123 flags |= RTCF_LOCAL; 2124 goto make_route; 2125 } 2126 2127 if (fib_lookup(net, fl4, &res)) { 2128 res.fi = NULL; 2129 res.table = NULL; 2130 if (fl4->flowi4_oif) { 2131 /* Apparently, routing tables are wrong. Assume, 2132 that the destination is on link. 2133 2134 WHY? DW. 2135 Because we are allowed to send to iface 2136 even if it has NO routes and NO assigned 2137 addresses. When oif is specified, routing 2138 tables are looked up with only one purpose: 2139 to catch if destination is gatewayed, rather than 2140 direct. Moreover, if MSG_DONTROUTE is set, 2141 we send packet, ignoring both routing tables 2142 and ifaddr state. --ANK 2143 2144 2145 We could make it even if oif is unknown, 2146 likely IPv6, but we do not. 2147 */ 2148 2149 if (fl4->saddr == 0) 2150 fl4->saddr = inet_select_addr(dev_out, 0, 2151 RT_SCOPE_LINK); 2152 res.type = RTN_UNICAST; 2153 goto make_route; 2154 } 2155 rth = ERR_PTR(-ENETUNREACH); 2156 goto out; 2157 } 2158 2159 if (res.type == RTN_LOCAL) { 2160 if (!fl4->saddr) { 2161 if (res.fi->fib_prefsrc) 2162 fl4->saddr = res.fi->fib_prefsrc; 2163 else 2164 fl4->saddr = fl4->daddr; 2165 } 2166 dev_out = net->loopback_dev; 2167 fl4->flowi4_oif = dev_out->ifindex; 2168 flags |= RTCF_LOCAL; 2169 goto make_route; 2170 } 2171 2172 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2173 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2174 fib_select_multipath(&res); 2175 else 2176 #endif 2177 if (!res.prefixlen && 2178 res.table->tb_num_default > 1 && 2179 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2180 fib_select_default(&res); 2181 2182 if (!fl4->saddr) 2183 fl4->saddr = FIB_RES_PREFSRC(net, res); 2184 2185 dev_out = FIB_RES_DEV(res); 2186 fl4->flowi4_oif = dev_out->ifindex; 2187 2188 2189 make_route: 2190 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2191 2192 out: 2193 rcu_read_unlock(); 2194 return rth; 2195 } 2196 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2197 2198 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2199 { 2200 return NULL; 2201 } 2202 2203 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2204 { 2205 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2206 2207 return mtu ? : dst->dev->mtu; 2208 } 2209 2210 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2211 struct sk_buff *skb, u32 mtu) 2212 { 2213 } 2214 2215 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2216 struct sk_buff *skb) 2217 { 2218 } 2219 2220 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2221 unsigned long old) 2222 { 2223 return NULL; 2224 } 2225 2226 static struct dst_ops ipv4_dst_blackhole_ops = { 2227 .family = AF_INET, 2228 .check = ipv4_blackhole_dst_check, 2229 .mtu = ipv4_blackhole_mtu, 2230 .default_advmss = ipv4_default_advmss, 2231 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2232 .redirect = ipv4_rt_blackhole_redirect, 2233 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2234 .neigh_lookup = ipv4_neigh_lookup, 2235 }; 2236 2237 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2238 { 2239 struct rtable *ort = (struct rtable *) dst_orig; 2240 struct rtable *rt; 2241 2242 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2243 if (rt) { 2244 struct dst_entry *new = &rt->dst; 2245 2246 new->__use = 1; 2247 new->input = dst_discard; 2248 new->output = dst_discard_sk; 2249 2250 new->dev = ort->dst.dev; 2251 if (new->dev) 2252 dev_hold(new->dev); 2253 2254 rt->rt_is_input = ort->rt_is_input; 2255 rt->rt_iif = ort->rt_iif; 2256 rt->rt_pmtu = ort->rt_pmtu; 2257 2258 rt->rt_genid = rt_genid_ipv4(net); 2259 rt->rt_flags = ort->rt_flags; 2260 rt->rt_type = ort->rt_type; 2261 rt->rt_gateway = ort->rt_gateway; 2262 rt->rt_uses_gateway = ort->rt_uses_gateway; 2263 2264 INIT_LIST_HEAD(&rt->rt_uncached); 2265 2266 dst_free(new); 2267 } 2268 2269 dst_release(dst_orig); 2270 2271 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2272 } 2273 2274 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2275 struct sock *sk) 2276 { 2277 struct rtable *rt = __ip_route_output_key(net, flp4); 2278 2279 if (IS_ERR(rt)) 2280 return rt; 2281 2282 if (flp4->flowi4_proto) 2283 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2284 flowi4_to_flowi(flp4), 2285 sk, 0); 2286 2287 return rt; 2288 } 2289 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2290 2291 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2292 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2293 u32 seq, int event, int nowait, unsigned int flags) 2294 { 2295 struct rtable *rt = skb_rtable(skb); 2296 struct rtmsg *r; 2297 struct nlmsghdr *nlh; 2298 unsigned long expires = 0; 2299 u32 error; 2300 u32 metrics[RTAX_MAX]; 2301 2302 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2303 if (!nlh) 2304 return -EMSGSIZE; 2305 2306 r = nlmsg_data(nlh); 2307 r->rtm_family = AF_INET; 2308 r->rtm_dst_len = 32; 2309 r->rtm_src_len = 0; 2310 r->rtm_tos = fl4->flowi4_tos; 2311 r->rtm_table = RT_TABLE_MAIN; 2312 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) 2313 goto nla_put_failure; 2314 r->rtm_type = rt->rt_type; 2315 r->rtm_scope = RT_SCOPE_UNIVERSE; 2316 r->rtm_protocol = RTPROT_UNSPEC; 2317 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2318 if (rt->rt_flags & RTCF_NOTIFY) 2319 r->rtm_flags |= RTM_F_NOTIFY; 2320 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2321 r->rtm_flags |= RTCF_DOREDIRECT; 2322 2323 if (nla_put_in_addr(skb, RTA_DST, dst)) 2324 goto nla_put_failure; 2325 if (src) { 2326 r->rtm_src_len = 32; 2327 if (nla_put_in_addr(skb, RTA_SRC, src)) 2328 goto nla_put_failure; 2329 } 2330 if (rt->dst.dev && 2331 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2332 goto nla_put_failure; 2333 #ifdef CONFIG_IP_ROUTE_CLASSID 2334 if (rt->dst.tclassid && 2335 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2336 goto nla_put_failure; 2337 #endif 2338 if (!rt_is_input_route(rt) && 2339 fl4->saddr != src) { 2340 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2341 goto nla_put_failure; 2342 } 2343 if (rt->rt_uses_gateway && 2344 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2345 goto nla_put_failure; 2346 2347 expires = rt->dst.expires; 2348 if (expires) { 2349 unsigned long now = jiffies; 2350 2351 if (time_before(now, expires)) 2352 expires -= now; 2353 else 2354 expires = 0; 2355 } 2356 2357 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2358 if (rt->rt_pmtu && expires) 2359 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2360 if (rtnetlink_put_metrics(skb, metrics) < 0) 2361 goto nla_put_failure; 2362 2363 if (fl4->flowi4_mark && 2364 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2365 goto nla_put_failure; 2366 2367 error = rt->dst.error; 2368 2369 if (rt_is_input_route(rt)) { 2370 #ifdef CONFIG_IP_MROUTE 2371 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2372 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2373 int err = ipmr_get_route(net, skb, 2374 fl4->saddr, fl4->daddr, 2375 r, nowait); 2376 if (err <= 0) { 2377 if (!nowait) { 2378 if (err == 0) 2379 return 0; 2380 goto nla_put_failure; 2381 } else { 2382 if (err == -EMSGSIZE) 2383 goto nla_put_failure; 2384 error = err; 2385 } 2386 } 2387 } else 2388 #endif 2389 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) 2390 goto nla_put_failure; 2391 } 2392 2393 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2394 goto nla_put_failure; 2395 2396 nlmsg_end(skb, nlh); 2397 return 0; 2398 2399 nla_put_failure: 2400 nlmsg_cancel(skb, nlh); 2401 return -EMSGSIZE; 2402 } 2403 2404 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 2405 { 2406 struct net *net = sock_net(in_skb->sk); 2407 struct rtmsg *rtm; 2408 struct nlattr *tb[RTA_MAX+1]; 2409 struct rtable *rt = NULL; 2410 struct flowi4 fl4; 2411 __be32 dst = 0; 2412 __be32 src = 0; 2413 u32 iif; 2414 int err; 2415 int mark; 2416 struct sk_buff *skb; 2417 2418 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2419 if (err < 0) 2420 goto errout; 2421 2422 rtm = nlmsg_data(nlh); 2423 2424 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2425 if (!skb) { 2426 err = -ENOBUFS; 2427 goto errout; 2428 } 2429 2430 /* Reserve room for dummy headers, this skb can pass 2431 through good chunk of routing engine. 2432 */ 2433 skb_reset_mac_header(skb); 2434 skb_reset_network_header(skb); 2435 2436 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2437 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2438 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2439 2440 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2441 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2442 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2443 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2444 2445 memset(&fl4, 0, sizeof(fl4)); 2446 fl4.daddr = dst; 2447 fl4.saddr = src; 2448 fl4.flowi4_tos = rtm->rtm_tos; 2449 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2450 fl4.flowi4_mark = mark; 2451 2452 if (iif) { 2453 struct net_device *dev; 2454 2455 dev = __dev_get_by_index(net, iif); 2456 if (!dev) { 2457 err = -ENODEV; 2458 goto errout_free; 2459 } 2460 2461 skb->protocol = htons(ETH_P_IP); 2462 skb->dev = dev; 2463 skb->mark = mark; 2464 local_bh_disable(); 2465 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2466 local_bh_enable(); 2467 2468 rt = skb_rtable(skb); 2469 if (err == 0 && rt->dst.error) 2470 err = -rt->dst.error; 2471 } else { 2472 rt = ip_route_output_key(net, &fl4); 2473 2474 err = 0; 2475 if (IS_ERR(rt)) 2476 err = PTR_ERR(rt); 2477 } 2478 2479 if (err) 2480 goto errout_free; 2481 2482 skb_dst_set(skb, &rt->dst); 2483 if (rtm->rtm_flags & RTM_F_NOTIFY) 2484 rt->rt_flags |= RTCF_NOTIFY; 2485 2486 err = rt_fill_info(net, dst, src, &fl4, skb, 2487 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2488 RTM_NEWROUTE, 0, 0); 2489 if (err < 0) 2490 goto errout_free; 2491 2492 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2493 errout: 2494 return err; 2495 2496 errout_free: 2497 kfree_skb(skb); 2498 goto errout; 2499 } 2500 2501 void ip_rt_multicast_event(struct in_device *in_dev) 2502 { 2503 rt_cache_flush(dev_net(in_dev->dev)); 2504 } 2505 2506 #ifdef CONFIG_SYSCTL 2507 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2508 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2509 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2510 static int ip_rt_gc_elasticity __read_mostly = 8; 2511 2512 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2513 void __user *buffer, 2514 size_t *lenp, loff_t *ppos) 2515 { 2516 struct net *net = (struct net *)__ctl->extra1; 2517 2518 if (write) { 2519 rt_cache_flush(net); 2520 fnhe_genid_bump(net); 2521 return 0; 2522 } 2523 2524 return -EINVAL; 2525 } 2526 2527 static struct ctl_table ipv4_route_table[] = { 2528 { 2529 .procname = "gc_thresh", 2530 .data = &ipv4_dst_ops.gc_thresh, 2531 .maxlen = sizeof(int), 2532 .mode = 0644, 2533 .proc_handler = proc_dointvec, 2534 }, 2535 { 2536 .procname = "max_size", 2537 .data = &ip_rt_max_size, 2538 .maxlen = sizeof(int), 2539 .mode = 0644, 2540 .proc_handler = proc_dointvec, 2541 }, 2542 { 2543 /* Deprecated. Use gc_min_interval_ms */ 2544 2545 .procname = "gc_min_interval", 2546 .data = &ip_rt_gc_min_interval, 2547 .maxlen = sizeof(int), 2548 .mode = 0644, 2549 .proc_handler = proc_dointvec_jiffies, 2550 }, 2551 { 2552 .procname = "gc_min_interval_ms", 2553 .data = &ip_rt_gc_min_interval, 2554 .maxlen = sizeof(int), 2555 .mode = 0644, 2556 .proc_handler = proc_dointvec_ms_jiffies, 2557 }, 2558 { 2559 .procname = "gc_timeout", 2560 .data = &ip_rt_gc_timeout, 2561 .maxlen = sizeof(int), 2562 .mode = 0644, 2563 .proc_handler = proc_dointvec_jiffies, 2564 }, 2565 { 2566 .procname = "gc_interval", 2567 .data = &ip_rt_gc_interval, 2568 .maxlen = sizeof(int), 2569 .mode = 0644, 2570 .proc_handler = proc_dointvec_jiffies, 2571 }, 2572 { 2573 .procname = "redirect_load", 2574 .data = &ip_rt_redirect_load, 2575 .maxlen = sizeof(int), 2576 .mode = 0644, 2577 .proc_handler = proc_dointvec, 2578 }, 2579 { 2580 .procname = "redirect_number", 2581 .data = &ip_rt_redirect_number, 2582 .maxlen = sizeof(int), 2583 .mode = 0644, 2584 .proc_handler = proc_dointvec, 2585 }, 2586 { 2587 .procname = "redirect_silence", 2588 .data = &ip_rt_redirect_silence, 2589 .maxlen = sizeof(int), 2590 .mode = 0644, 2591 .proc_handler = proc_dointvec, 2592 }, 2593 { 2594 .procname = "error_cost", 2595 .data = &ip_rt_error_cost, 2596 .maxlen = sizeof(int), 2597 .mode = 0644, 2598 .proc_handler = proc_dointvec, 2599 }, 2600 { 2601 .procname = "error_burst", 2602 .data = &ip_rt_error_burst, 2603 .maxlen = sizeof(int), 2604 .mode = 0644, 2605 .proc_handler = proc_dointvec, 2606 }, 2607 { 2608 .procname = "gc_elasticity", 2609 .data = &ip_rt_gc_elasticity, 2610 .maxlen = sizeof(int), 2611 .mode = 0644, 2612 .proc_handler = proc_dointvec, 2613 }, 2614 { 2615 .procname = "mtu_expires", 2616 .data = &ip_rt_mtu_expires, 2617 .maxlen = sizeof(int), 2618 .mode = 0644, 2619 .proc_handler = proc_dointvec_jiffies, 2620 }, 2621 { 2622 .procname = "min_pmtu", 2623 .data = &ip_rt_min_pmtu, 2624 .maxlen = sizeof(int), 2625 .mode = 0644, 2626 .proc_handler = proc_dointvec, 2627 }, 2628 { 2629 .procname = "min_adv_mss", 2630 .data = &ip_rt_min_advmss, 2631 .maxlen = sizeof(int), 2632 .mode = 0644, 2633 .proc_handler = proc_dointvec, 2634 }, 2635 { } 2636 }; 2637 2638 static struct ctl_table ipv4_route_flush_table[] = { 2639 { 2640 .procname = "flush", 2641 .maxlen = sizeof(int), 2642 .mode = 0200, 2643 .proc_handler = ipv4_sysctl_rtcache_flush, 2644 }, 2645 { }, 2646 }; 2647 2648 static __net_init int sysctl_route_net_init(struct net *net) 2649 { 2650 struct ctl_table *tbl; 2651 2652 tbl = ipv4_route_flush_table; 2653 if (!net_eq(net, &init_net)) { 2654 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2655 if (!tbl) 2656 goto err_dup; 2657 2658 /* Don't export sysctls to unprivileged users */ 2659 if (net->user_ns != &init_user_ns) 2660 tbl[0].procname = NULL; 2661 } 2662 tbl[0].extra1 = net; 2663 2664 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2665 if (!net->ipv4.route_hdr) 2666 goto err_reg; 2667 return 0; 2668 2669 err_reg: 2670 if (tbl != ipv4_route_flush_table) 2671 kfree(tbl); 2672 err_dup: 2673 return -ENOMEM; 2674 } 2675 2676 static __net_exit void sysctl_route_net_exit(struct net *net) 2677 { 2678 struct ctl_table *tbl; 2679 2680 tbl = net->ipv4.route_hdr->ctl_table_arg; 2681 unregister_net_sysctl_table(net->ipv4.route_hdr); 2682 BUG_ON(tbl == ipv4_route_flush_table); 2683 kfree(tbl); 2684 } 2685 2686 static __net_initdata struct pernet_operations sysctl_route_ops = { 2687 .init = sysctl_route_net_init, 2688 .exit = sysctl_route_net_exit, 2689 }; 2690 #endif 2691 2692 static __net_init int rt_genid_init(struct net *net) 2693 { 2694 atomic_set(&net->ipv4.rt_genid, 0); 2695 atomic_set(&net->fnhe_genid, 0); 2696 get_random_bytes(&net->ipv4.dev_addr_genid, 2697 sizeof(net->ipv4.dev_addr_genid)); 2698 return 0; 2699 } 2700 2701 static __net_initdata struct pernet_operations rt_genid_ops = { 2702 .init = rt_genid_init, 2703 }; 2704 2705 static int __net_init ipv4_inetpeer_init(struct net *net) 2706 { 2707 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2708 2709 if (!bp) 2710 return -ENOMEM; 2711 inet_peer_base_init(bp); 2712 net->ipv4.peers = bp; 2713 return 0; 2714 } 2715 2716 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2717 { 2718 struct inet_peer_base *bp = net->ipv4.peers; 2719 2720 net->ipv4.peers = NULL; 2721 inetpeer_invalidate_tree(bp); 2722 kfree(bp); 2723 } 2724 2725 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2726 .init = ipv4_inetpeer_init, 2727 .exit = ipv4_inetpeer_exit, 2728 }; 2729 2730 #ifdef CONFIG_IP_ROUTE_CLASSID 2731 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2732 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2733 2734 int __init ip_rt_init(void) 2735 { 2736 int rc = 0; 2737 int cpu; 2738 2739 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); 2740 if (!ip_idents) 2741 panic("IP: failed to allocate ip_idents\n"); 2742 2743 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 2744 2745 for_each_possible_cpu(cpu) { 2746 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 2747 2748 INIT_LIST_HEAD(&ul->head); 2749 spin_lock_init(&ul->lock); 2750 } 2751 #ifdef CONFIG_IP_ROUTE_CLASSID 2752 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2753 if (!ip_rt_acct) 2754 panic("IP: failed to allocate ip_rt_acct\n"); 2755 #endif 2756 2757 ipv4_dst_ops.kmem_cachep = 2758 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2759 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2760 2761 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2762 2763 if (dst_entries_init(&ipv4_dst_ops) < 0) 2764 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2765 2766 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2767 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2768 2769 ipv4_dst_ops.gc_thresh = ~0; 2770 ip_rt_max_size = INT_MAX; 2771 2772 devinet_init(); 2773 ip_fib_init(); 2774 2775 if (ip_rt_proc_init()) 2776 pr_err("Unable to create route proc files\n"); 2777 #ifdef CONFIG_XFRM 2778 xfrm_init(); 2779 xfrm4_init(); 2780 #endif 2781 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2782 2783 #ifdef CONFIG_SYSCTL 2784 register_pernet_subsys(&sysctl_route_ops); 2785 #endif 2786 register_pernet_subsys(&rt_genid_ops); 2787 register_pernet_subsys(&ipv4_inetpeer_ops); 2788 return rc; 2789 } 2790 2791 #ifdef CONFIG_SYSCTL 2792 /* 2793 * We really need to sanitize the damn ipv4 init order, then all 2794 * this nonsense will go away. 2795 */ 2796 void __init ip_static_sysctl_init(void) 2797 { 2798 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2799 } 2800 #endif 2801