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