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 .protocol = cpu_to_be16(ETH_P_IP), 156 .check = ipv4_dst_check, 157 .default_advmss = ipv4_default_advmss, 158 .mtu = ipv4_mtu, 159 .cow_metrics = ipv4_cow_metrics, 160 .destroy = ipv4_dst_destroy, 161 .negative_advice = ipv4_negative_advice, 162 .link_failure = ipv4_link_failure, 163 .update_pmtu = ip_rt_update_pmtu, 164 .redirect = ip_do_redirect, 165 .local_out = __ip_local_out, 166 .neigh_lookup = ipv4_neigh_lookup, 167 }; 168 169 #define ECN_OR_COST(class) TC_PRIO_##class 170 171 const __u8 ip_tos2prio[16] = { 172 TC_PRIO_BESTEFFORT, 173 ECN_OR_COST(BESTEFFORT), 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BULK, 177 ECN_OR_COST(BULK), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_INTERACTIVE, 181 ECN_OR_COST(INTERACTIVE), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE_BULK, 185 ECN_OR_COST(INTERACTIVE_BULK), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK) 188 }; 189 EXPORT_SYMBOL(ip_tos2prio); 190 191 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 192 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 193 194 #ifdef CONFIG_PROC_FS 195 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 196 { 197 if (*pos) 198 return NULL; 199 return SEQ_START_TOKEN; 200 } 201 202 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 203 { 204 ++*pos; 205 return NULL; 206 } 207 208 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 209 { 210 } 211 212 static int rt_cache_seq_show(struct seq_file *seq, void *v) 213 { 214 if (v == SEQ_START_TOKEN) 215 seq_printf(seq, "%-127s\n", 216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 218 "HHUptod\tSpecDst"); 219 return 0; 220 } 221 222 static const struct seq_operations rt_cache_seq_ops = { 223 .start = rt_cache_seq_start, 224 .next = rt_cache_seq_next, 225 .stop = rt_cache_seq_stop, 226 .show = rt_cache_seq_show, 227 }; 228 229 static int rt_cache_seq_open(struct inode *inode, struct file *file) 230 { 231 return seq_open(file, &rt_cache_seq_ops); 232 } 233 234 static const struct file_operations rt_cache_seq_fops = { 235 .owner = THIS_MODULE, 236 .open = rt_cache_seq_open, 237 .read = seq_read, 238 .llseek = seq_lseek, 239 .release = seq_release, 240 }; 241 242 243 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 244 { 245 int cpu; 246 247 if (*pos == 0) 248 return SEQ_START_TOKEN; 249 250 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 251 if (!cpu_possible(cpu)) 252 continue; 253 *pos = cpu+1; 254 return &per_cpu(rt_cache_stat, cpu); 255 } 256 return NULL; 257 } 258 259 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 260 { 261 int cpu; 262 263 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 264 if (!cpu_possible(cpu)) 265 continue; 266 *pos = cpu+1; 267 return &per_cpu(rt_cache_stat, cpu); 268 } 269 return NULL; 270 271 } 272 273 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 274 { 275 276 } 277 278 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 279 { 280 struct rt_cache_stat *st = v; 281 282 if (v == SEQ_START_TOKEN) { 283 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"); 284 return 0; 285 } 286 287 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 288 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 289 dst_entries_get_slow(&ipv4_dst_ops), 290 0, /* st->in_hit */ 291 st->in_slow_tot, 292 st->in_slow_mc, 293 st->in_no_route, 294 st->in_brd, 295 st->in_martian_dst, 296 st->in_martian_src, 297 298 0, /* st->out_hit */ 299 st->out_slow_tot, 300 st->out_slow_mc, 301 302 0, /* st->gc_total */ 303 0, /* st->gc_ignored */ 304 0, /* st->gc_goal_miss */ 305 0, /* st->gc_dst_overflow */ 306 0, /* st->in_hlist_search */ 307 0 /* st->out_hlist_search */ 308 ); 309 return 0; 310 } 311 312 static const struct seq_operations rt_cpu_seq_ops = { 313 .start = rt_cpu_seq_start, 314 .next = rt_cpu_seq_next, 315 .stop = rt_cpu_seq_stop, 316 .show = rt_cpu_seq_show, 317 }; 318 319 320 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 321 { 322 return seq_open(file, &rt_cpu_seq_ops); 323 } 324 325 static const struct file_operations rt_cpu_seq_fops = { 326 .owner = THIS_MODULE, 327 .open = rt_cpu_seq_open, 328 .read = seq_read, 329 .llseek = seq_lseek, 330 .release = seq_release, 331 }; 332 333 #ifdef CONFIG_IP_ROUTE_CLASSID 334 static int rt_acct_proc_show(struct seq_file *m, void *v) 335 { 336 struct ip_rt_acct *dst, *src; 337 unsigned int i, j; 338 339 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 340 if (!dst) 341 return -ENOMEM; 342 343 for_each_possible_cpu(i) { 344 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 345 for (j = 0; j < 256; j++) { 346 dst[j].o_bytes += src[j].o_bytes; 347 dst[j].o_packets += src[j].o_packets; 348 dst[j].i_bytes += src[j].i_bytes; 349 dst[j].i_packets += src[j].i_packets; 350 } 351 } 352 353 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 354 kfree(dst); 355 return 0; 356 } 357 358 static int rt_acct_proc_open(struct inode *inode, struct file *file) 359 { 360 return single_open(file, rt_acct_proc_show, NULL); 361 } 362 363 static const struct file_operations rt_acct_proc_fops = { 364 .owner = THIS_MODULE, 365 .open = rt_acct_proc_open, 366 .read = seq_read, 367 .llseek = seq_lseek, 368 .release = single_release, 369 }; 370 #endif 371 372 static int __net_init ip_rt_do_proc_init(struct net *net) 373 { 374 struct proc_dir_entry *pde; 375 376 pde = proc_create("rt_cache", S_IRUGO, net->proc_net, 377 &rt_cache_seq_fops); 378 if (!pde) 379 goto err1; 380 381 pde = proc_create("rt_cache", S_IRUGO, 382 net->proc_net_stat, &rt_cpu_seq_fops); 383 if (!pde) 384 goto err2; 385 386 #ifdef CONFIG_IP_ROUTE_CLASSID 387 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 388 if (!pde) 389 goto err3; 390 #endif 391 return 0; 392 393 #ifdef CONFIG_IP_ROUTE_CLASSID 394 err3: 395 remove_proc_entry("rt_cache", net->proc_net_stat); 396 #endif 397 err2: 398 remove_proc_entry("rt_cache", net->proc_net); 399 err1: 400 return -ENOMEM; 401 } 402 403 static void __net_exit ip_rt_do_proc_exit(struct net *net) 404 { 405 remove_proc_entry("rt_cache", net->proc_net_stat); 406 remove_proc_entry("rt_cache", net->proc_net); 407 #ifdef CONFIG_IP_ROUTE_CLASSID 408 remove_proc_entry("rt_acct", net->proc_net); 409 #endif 410 } 411 412 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 413 .init = ip_rt_do_proc_init, 414 .exit = ip_rt_do_proc_exit, 415 }; 416 417 static int __init ip_rt_proc_init(void) 418 { 419 return register_pernet_subsys(&ip_rt_proc_ops); 420 } 421 422 #else 423 static inline int ip_rt_proc_init(void) 424 { 425 return 0; 426 } 427 #endif /* CONFIG_PROC_FS */ 428 429 static inline bool rt_is_expired(const struct rtable *rth) 430 { 431 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 432 } 433 434 void rt_cache_flush(struct net *net) 435 { 436 rt_genid_bump_ipv4(net); 437 } 438 439 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 440 struct sk_buff *skb, 441 const void *daddr) 442 { 443 struct net_device *dev = dst->dev; 444 const __be32 *pkey = daddr; 445 const struct rtable *rt; 446 struct neighbour *n; 447 448 rt = (const struct rtable *) dst; 449 if (rt->rt_gateway) 450 pkey = (const __be32 *) &rt->rt_gateway; 451 else if (skb) 452 pkey = &ip_hdr(skb)->daddr; 453 454 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 455 if (n) 456 return n; 457 return neigh_create(&arp_tbl, pkey, dev); 458 } 459 460 #define IP_IDENTS_SZ 2048u 461 struct ip_ident_bucket { 462 atomic_t id; 463 u32 stamp32; 464 }; 465 466 static struct ip_ident_bucket *ip_idents __read_mostly; 467 468 /* In order to protect privacy, we add a perturbation to identifiers 469 * if one generator is seldom used. This makes hard for an attacker 470 * to infer how many packets were sent between two points in time. 471 */ 472 u32 ip_idents_reserve(u32 hash, int segs) 473 { 474 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ; 475 u32 old = ACCESS_ONCE(bucket->stamp32); 476 u32 now = (u32)jiffies; 477 u32 delta = 0; 478 479 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old) 480 delta = prandom_u32_max(now - old); 481 482 return atomic_add_return(segs + delta, &bucket->id) - segs; 483 } 484 EXPORT_SYMBOL(ip_idents_reserve); 485 486 void __ip_select_ident(struct iphdr *iph, int segs) 487 { 488 static u32 ip_idents_hashrnd __read_mostly; 489 u32 hash, id; 490 491 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); 492 493 hash = jhash_3words((__force u32)iph->daddr, 494 (__force u32)iph->saddr, 495 iph->protocol, 496 ip_idents_hashrnd); 497 id = ip_idents_reserve(hash, segs); 498 iph->id = htons(id); 499 } 500 EXPORT_SYMBOL(__ip_select_ident); 501 502 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, 503 const struct iphdr *iph, 504 int oif, u8 tos, 505 u8 prot, u32 mark, int flow_flags) 506 { 507 if (sk) { 508 const struct inet_sock *inet = inet_sk(sk); 509 510 oif = sk->sk_bound_dev_if; 511 mark = sk->sk_mark; 512 tos = RT_CONN_FLAGS(sk); 513 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 514 } 515 flowi4_init_output(fl4, oif, mark, tos, 516 RT_SCOPE_UNIVERSE, prot, 517 flow_flags, 518 iph->daddr, iph->saddr, 0, 0); 519 } 520 521 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 522 const struct sock *sk) 523 { 524 const struct iphdr *iph = ip_hdr(skb); 525 int oif = skb->dev->ifindex; 526 u8 tos = RT_TOS(iph->tos); 527 u8 prot = iph->protocol; 528 u32 mark = skb->mark; 529 530 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0); 531 } 532 533 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 534 { 535 const struct inet_sock *inet = inet_sk(sk); 536 const struct ip_options_rcu *inet_opt; 537 __be32 daddr = inet->inet_daddr; 538 539 rcu_read_lock(); 540 inet_opt = rcu_dereference(inet->inet_opt); 541 if (inet_opt && inet_opt->opt.srr) 542 daddr = inet_opt->opt.faddr; 543 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 544 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 545 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 546 inet_sk_flowi_flags(sk), 547 daddr, inet->inet_saddr, 0, 0); 548 rcu_read_unlock(); 549 } 550 551 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 552 const struct sk_buff *skb) 553 { 554 if (skb) 555 build_skb_flow_key(fl4, skb, sk); 556 else 557 build_sk_flow_key(fl4, sk); 558 } 559 560 static inline void rt_free(struct rtable *rt) 561 { 562 call_rcu(&rt->dst.rcu_head, dst_rcu_free); 563 } 564 565 static DEFINE_SPINLOCK(fnhe_lock); 566 567 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 568 { 569 struct rtable *rt; 570 571 rt = rcu_dereference(fnhe->fnhe_rth_input); 572 if (rt) { 573 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 574 rt_free(rt); 575 } 576 rt = rcu_dereference(fnhe->fnhe_rth_output); 577 if (rt) { 578 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 579 rt_free(rt); 580 } 581 } 582 583 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 584 { 585 struct fib_nh_exception *fnhe, *oldest; 586 587 oldest = rcu_dereference(hash->chain); 588 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 589 fnhe = rcu_dereference(fnhe->fnhe_next)) { 590 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 591 oldest = fnhe; 592 } 593 fnhe_flush_routes(oldest); 594 return oldest; 595 } 596 597 static inline u32 fnhe_hashfun(__be32 daddr) 598 { 599 static u32 fnhe_hashrnd __read_mostly; 600 u32 hval; 601 602 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 603 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 604 return hash_32(hval, FNHE_HASH_SHIFT); 605 } 606 607 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 608 { 609 rt->rt_pmtu = fnhe->fnhe_pmtu; 610 rt->dst.expires = fnhe->fnhe_expires; 611 612 if (fnhe->fnhe_gw) { 613 rt->rt_flags |= RTCF_REDIRECTED; 614 rt->rt_gateway = fnhe->fnhe_gw; 615 rt->rt_uses_gateway = 1; 616 } 617 } 618 619 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 620 u32 pmtu, unsigned long expires) 621 { 622 struct fnhe_hash_bucket *hash; 623 struct fib_nh_exception *fnhe; 624 struct rtable *rt; 625 unsigned int i; 626 int depth; 627 u32 hval = fnhe_hashfun(daddr); 628 629 spin_lock_bh(&fnhe_lock); 630 631 hash = rcu_dereference(nh->nh_exceptions); 632 if (!hash) { 633 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); 634 if (!hash) 635 goto out_unlock; 636 rcu_assign_pointer(nh->nh_exceptions, hash); 637 } 638 639 hash += hval; 640 641 depth = 0; 642 for (fnhe = rcu_dereference(hash->chain); fnhe; 643 fnhe = rcu_dereference(fnhe->fnhe_next)) { 644 if (fnhe->fnhe_daddr == daddr) 645 break; 646 depth++; 647 } 648 649 if (fnhe) { 650 if (gw) 651 fnhe->fnhe_gw = gw; 652 if (pmtu) { 653 fnhe->fnhe_pmtu = pmtu; 654 fnhe->fnhe_expires = max(1UL, expires); 655 } 656 /* Update all cached dsts too */ 657 rt = rcu_dereference(fnhe->fnhe_rth_input); 658 if (rt) 659 fill_route_from_fnhe(rt, fnhe); 660 rt = rcu_dereference(fnhe->fnhe_rth_output); 661 if (rt) 662 fill_route_from_fnhe(rt, fnhe); 663 } else { 664 if (depth > FNHE_RECLAIM_DEPTH) 665 fnhe = fnhe_oldest(hash); 666 else { 667 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 668 if (!fnhe) 669 goto out_unlock; 670 671 fnhe->fnhe_next = hash->chain; 672 rcu_assign_pointer(hash->chain, fnhe); 673 } 674 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev)); 675 fnhe->fnhe_daddr = daddr; 676 fnhe->fnhe_gw = gw; 677 fnhe->fnhe_pmtu = pmtu; 678 fnhe->fnhe_expires = expires; 679 680 /* Exception created; mark the cached routes for the nexthop 681 * stale, so anyone caching it rechecks if this exception 682 * applies to them. 683 */ 684 rt = rcu_dereference(nh->nh_rth_input); 685 if (rt) 686 rt->dst.obsolete = DST_OBSOLETE_KILL; 687 688 for_each_possible_cpu(i) { 689 struct rtable __rcu **prt; 690 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 691 rt = rcu_dereference(*prt); 692 if (rt) 693 rt->dst.obsolete = DST_OBSOLETE_KILL; 694 } 695 } 696 697 fnhe->fnhe_stamp = jiffies; 698 699 out_unlock: 700 spin_unlock_bh(&fnhe_lock); 701 } 702 703 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 704 bool kill_route) 705 { 706 __be32 new_gw = icmp_hdr(skb)->un.gateway; 707 __be32 old_gw = ip_hdr(skb)->saddr; 708 struct net_device *dev = skb->dev; 709 struct in_device *in_dev; 710 struct fib_result res; 711 struct neighbour *n; 712 struct net *net; 713 714 switch (icmp_hdr(skb)->code & 7) { 715 case ICMP_REDIR_NET: 716 case ICMP_REDIR_NETTOS: 717 case ICMP_REDIR_HOST: 718 case ICMP_REDIR_HOSTTOS: 719 break; 720 721 default: 722 return; 723 } 724 725 if (rt->rt_gateway != old_gw) 726 return; 727 728 in_dev = __in_dev_get_rcu(dev); 729 if (!in_dev) 730 return; 731 732 net = dev_net(dev); 733 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 734 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 735 ipv4_is_zeronet(new_gw)) 736 goto reject_redirect; 737 738 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 739 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 740 goto reject_redirect; 741 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 742 goto reject_redirect; 743 } else { 744 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 745 goto reject_redirect; 746 } 747 748 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); 749 if (!IS_ERR(n)) { 750 if (!(n->nud_state & NUD_VALID)) { 751 neigh_event_send(n, NULL); 752 } else { 753 if (fib_lookup(net, fl4, &res) == 0) { 754 struct fib_nh *nh = &FIB_RES_NH(res); 755 756 update_or_create_fnhe(nh, fl4->daddr, new_gw, 757 0, 0); 758 } 759 if (kill_route) 760 rt->dst.obsolete = DST_OBSOLETE_KILL; 761 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 762 } 763 neigh_release(n); 764 } 765 return; 766 767 reject_redirect: 768 #ifdef CONFIG_IP_ROUTE_VERBOSE 769 if (IN_DEV_LOG_MARTIANS(in_dev)) { 770 const struct iphdr *iph = (const struct iphdr *) skb->data; 771 __be32 daddr = iph->daddr; 772 __be32 saddr = iph->saddr; 773 774 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 775 " Advised path = %pI4 -> %pI4\n", 776 &old_gw, dev->name, &new_gw, 777 &saddr, &daddr); 778 } 779 #endif 780 ; 781 } 782 783 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 784 { 785 struct rtable *rt; 786 struct flowi4 fl4; 787 const struct iphdr *iph = (const struct iphdr *) skb->data; 788 int oif = skb->dev->ifindex; 789 u8 tos = RT_TOS(iph->tos); 790 u8 prot = iph->protocol; 791 u32 mark = skb->mark; 792 793 rt = (struct rtable *) dst; 794 795 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0); 796 __ip_do_redirect(rt, skb, &fl4, true); 797 } 798 799 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 800 { 801 struct rtable *rt = (struct rtable *)dst; 802 struct dst_entry *ret = dst; 803 804 if (rt) { 805 if (dst->obsolete > 0) { 806 ip_rt_put(rt); 807 ret = NULL; 808 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 809 rt->dst.expires) { 810 ip_rt_put(rt); 811 ret = NULL; 812 } 813 } 814 return ret; 815 } 816 817 /* 818 * Algorithm: 819 * 1. The first ip_rt_redirect_number redirects are sent 820 * with exponential backoff, then we stop sending them at all, 821 * assuming that the host ignores our redirects. 822 * 2. If we did not see packets requiring redirects 823 * during ip_rt_redirect_silence, we assume that the host 824 * forgot redirected route and start to send redirects again. 825 * 826 * This algorithm is much cheaper and more intelligent than dumb load limiting 827 * in icmp.c. 828 * 829 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 830 * and "frag. need" (breaks PMTU discovery) in icmp.c. 831 */ 832 833 void ip_rt_send_redirect(struct sk_buff *skb) 834 { 835 struct rtable *rt = skb_rtable(skb); 836 struct in_device *in_dev; 837 struct inet_peer *peer; 838 struct net *net; 839 int log_martians; 840 841 rcu_read_lock(); 842 in_dev = __in_dev_get_rcu(rt->dst.dev); 843 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 844 rcu_read_unlock(); 845 return; 846 } 847 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 848 rcu_read_unlock(); 849 850 net = dev_net(rt->dst.dev); 851 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 852 if (!peer) { 853 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 854 rt_nexthop(rt, ip_hdr(skb)->daddr)); 855 return; 856 } 857 858 /* No redirected packets during ip_rt_redirect_silence; 859 * reset the algorithm. 860 */ 861 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 862 peer->rate_tokens = 0; 863 864 /* Too many ignored redirects; do not send anything 865 * set dst.rate_last to the last seen redirected packet. 866 */ 867 if (peer->rate_tokens >= ip_rt_redirect_number) { 868 peer->rate_last = jiffies; 869 goto out_put_peer; 870 } 871 872 /* Check for load limit; set rate_last to the latest sent 873 * redirect. 874 */ 875 if (peer->rate_tokens == 0 || 876 time_after(jiffies, 877 (peer->rate_last + 878 (ip_rt_redirect_load << peer->rate_tokens)))) { 879 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 880 881 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 882 peer->rate_last = jiffies; 883 ++peer->rate_tokens; 884 #ifdef CONFIG_IP_ROUTE_VERBOSE 885 if (log_martians && 886 peer->rate_tokens == ip_rt_redirect_number) 887 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 888 &ip_hdr(skb)->saddr, inet_iif(skb), 889 &ip_hdr(skb)->daddr, &gw); 890 #endif 891 } 892 out_put_peer: 893 inet_putpeer(peer); 894 } 895 896 static int ip_error(struct sk_buff *skb) 897 { 898 struct in_device *in_dev = __in_dev_get_rcu(skb->dev); 899 struct rtable *rt = skb_rtable(skb); 900 struct inet_peer *peer; 901 unsigned long now; 902 struct net *net; 903 bool send; 904 int code; 905 906 net = dev_net(rt->dst.dev); 907 if (!IN_DEV_FORWARD(in_dev)) { 908 switch (rt->dst.error) { 909 case EHOSTUNREACH: 910 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); 911 break; 912 913 case ENETUNREACH: 914 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 915 break; 916 } 917 goto out; 918 } 919 920 switch (rt->dst.error) { 921 case EINVAL: 922 default: 923 goto out; 924 case EHOSTUNREACH: 925 code = ICMP_HOST_UNREACH; 926 break; 927 case ENETUNREACH: 928 code = ICMP_NET_UNREACH; 929 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 930 break; 931 case EACCES: 932 code = ICMP_PKT_FILTERED; 933 break; 934 } 935 936 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 937 938 send = true; 939 if (peer) { 940 now = jiffies; 941 peer->rate_tokens += now - peer->rate_last; 942 if (peer->rate_tokens > ip_rt_error_burst) 943 peer->rate_tokens = ip_rt_error_burst; 944 peer->rate_last = now; 945 if (peer->rate_tokens >= ip_rt_error_cost) 946 peer->rate_tokens -= ip_rt_error_cost; 947 else 948 send = false; 949 inet_putpeer(peer); 950 } 951 if (send) 952 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 953 954 out: kfree_skb(skb); 955 return 0; 956 } 957 958 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 959 { 960 struct dst_entry *dst = &rt->dst; 961 struct fib_result res; 962 963 if (dst_metric_locked(dst, RTAX_MTU)) 964 return; 965 966 if (dst->dev->mtu < mtu) 967 return; 968 969 if (rt->rt_pmtu && rt->rt_pmtu < 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) == NULL) { 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 static DEFINE_SPINLOCK(rt_uncached_lock); 1332 static LIST_HEAD(rt_uncached_list); 1333 1334 static void rt_add_uncached_list(struct rtable *rt) 1335 { 1336 spin_lock_bh(&rt_uncached_lock); 1337 list_add_tail(&rt->rt_uncached, &rt_uncached_list); 1338 spin_unlock_bh(&rt_uncached_lock); 1339 } 1340 1341 static void ipv4_dst_destroy(struct dst_entry *dst) 1342 { 1343 struct rtable *rt = (struct rtable *) dst; 1344 1345 if (!list_empty(&rt->rt_uncached)) { 1346 spin_lock_bh(&rt_uncached_lock); 1347 list_del(&rt->rt_uncached); 1348 spin_unlock_bh(&rt_uncached_lock); 1349 } 1350 } 1351 1352 void rt_flush_dev(struct net_device *dev) 1353 { 1354 if (!list_empty(&rt_uncached_list)) { 1355 struct net *net = dev_net(dev); 1356 struct rtable *rt; 1357 1358 spin_lock_bh(&rt_uncached_lock); 1359 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) { 1360 if (rt->dst.dev != dev) 1361 continue; 1362 rt->dst.dev = net->loopback_dev; 1363 dev_hold(rt->dst.dev); 1364 dev_put(dev); 1365 } 1366 spin_unlock_bh(&rt_uncached_lock); 1367 } 1368 } 1369 1370 static bool rt_cache_valid(const struct rtable *rt) 1371 { 1372 return rt && 1373 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1374 !rt_is_expired(rt); 1375 } 1376 1377 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1378 const struct fib_result *res, 1379 struct fib_nh_exception *fnhe, 1380 struct fib_info *fi, u16 type, u32 itag) 1381 { 1382 bool cached = false; 1383 1384 if (fi) { 1385 struct fib_nh *nh = &FIB_RES_NH(*res); 1386 1387 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1388 rt->rt_gateway = nh->nh_gw; 1389 rt->rt_uses_gateway = 1; 1390 } 1391 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1392 #ifdef CONFIG_IP_ROUTE_CLASSID 1393 rt->dst.tclassid = nh->nh_tclassid; 1394 #endif 1395 if (unlikely(fnhe)) 1396 cached = rt_bind_exception(rt, fnhe, daddr); 1397 else if (!(rt->dst.flags & DST_NOCACHE)) 1398 cached = rt_cache_route(nh, rt); 1399 if (unlikely(!cached)) { 1400 /* Routes we intend to cache in nexthop exception or 1401 * FIB nexthop have the DST_NOCACHE bit clear. 1402 * However, if we are unsuccessful at storing this 1403 * route into the cache we really need to set it. 1404 */ 1405 rt->dst.flags |= DST_NOCACHE; 1406 if (!rt->rt_gateway) 1407 rt->rt_gateway = daddr; 1408 rt_add_uncached_list(rt); 1409 } 1410 } else 1411 rt_add_uncached_list(rt); 1412 1413 #ifdef CONFIG_IP_ROUTE_CLASSID 1414 #ifdef CONFIG_IP_MULTIPLE_TABLES 1415 set_class_tag(rt, res->tclassid); 1416 #endif 1417 set_class_tag(rt, itag); 1418 #endif 1419 } 1420 1421 static struct rtable *rt_dst_alloc(struct net_device *dev, 1422 bool nopolicy, bool noxfrm, bool will_cache) 1423 { 1424 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1425 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1426 (nopolicy ? DST_NOPOLICY : 0) | 1427 (noxfrm ? DST_NOXFRM : 0)); 1428 } 1429 1430 /* called in rcu_read_lock() section */ 1431 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1432 u8 tos, struct net_device *dev, int our) 1433 { 1434 struct rtable *rth; 1435 struct in_device *in_dev = __in_dev_get_rcu(dev); 1436 u32 itag = 0; 1437 int err; 1438 1439 /* Primary sanity checks. */ 1440 1441 if (in_dev == NULL) 1442 return -EINVAL; 1443 1444 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1445 skb->protocol != htons(ETH_P_IP)) 1446 goto e_inval; 1447 1448 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1449 if (ipv4_is_loopback(saddr)) 1450 goto e_inval; 1451 1452 if (ipv4_is_zeronet(saddr)) { 1453 if (!ipv4_is_local_multicast(daddr)) 1454 goto e_inval; 1455 } else { 1456 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1457 in_dev, &itag); 1458 if (err < 0) 1459 goto e_err; 1460 } 1461 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, 1462 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1463 if (!rth) 1464 goto e_nobufs; 1465 1466 #ifdef CONFIG_IP_ROUTE_CLASSID 1467 rth->dst.tclassid = itag; 1468 #endif 1469 rth->dst.output = ip_rt_bug; 1470 1471 rth->rt_genid = rt_genid_ipv4(dev_net(dev)); 1472 rth->rt_flags = RTCF_MULTICAST; 1473 rth->rt_type = RTN_MULTICAST; 1474 rth->rt_is_input= 1; 1475 rth->rt_iif = 0; 1476 rth->rt_pmtu = 0; 1477 rth->rt_gateway = 0; 1478 rth->rt_uses_gateway = 0; 1479 INIT_LIST_HEAD(&rth->rt_uncached); 1480 if (our) { 1481 rth->dst.input= ip_local_deliver; 1482 rth->rt_flags |= RTCF_LOCAL; 1483 } 1484 1485 #ifdef CONFIG_IP_MROUTE 1486 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1487 rth->dst.input = ip_mr_input; 1488 #endif 1489 RT_CACHE_STAT_INC(in_slow_mc); 1490 1491 skb_dst_set(skb, &rth->dst); 1492 return 0; 1493 1494 e_nobufs: 1495 return -ENOBUFS; 1496 e_inval: 1497 return -EINVAL; 1498 e_err: 1499 return err; 1500 } 1501 1502 1503 static void ip_handle_martian_source(struct net_device *dev, 1504 struct in_device *in_dev, 1505 struct sk_buff *skb, 1506 __be32 daddr, 1507 __be32 saddr) 1508 { 1509 RT_CACHE_STAT_INC(in_martian_src); 1510 #ifdef CONFIG_IP_ROUTE_VERBOSE 1511 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1512 /* 1513 * RFC1812 recommendation, if source is martian, 1514 * the only hint is MAC header. 1515 */ 1516 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1517 &daddr, &saddr, dev->name); 1518 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1519 print_hex_dump(KERN_WARNING, "ll header: ", 1520 DUMP_PREFIX_OFFSET, 16, 1, 1521 skb_mac_header(skb), 1522 dev->hard_header_len, true); 1523 } 1524 } 1525 #endif 1526 } 1527 1528 /* called in rcu_read_lock() section */ 1529 static int __mkroute_input(struct sk_buff *skb, 1530 const struct fib_result *res, 1531 struct in_device *in_dev, 1532 __be32 daddr, __be32 saddr, u32 tos) 1533 { 1534 struct fib_nh_exception *fnhe; 1535 struct rtable *rth; 1536 int err; 1537 struct in_device *out_dev; 1538 unsigned int flags = 0; 1539 bool do_cache; 1540 u32 itag = 0; 1541 1542 /* get a working reference to the output device */ 1543 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1544 if (out_dev == NULL) { 1545 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1546 return -EINVAL; 1547 } 1548 1549 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1550 in_dev->dev, in_dev, &itag); 1551 if (err < 0) { 1552 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1553 saddr); 1554 1555 goto cleanup; 1556 } 1557 1558 do_cache = res->fi && !itag; 1559 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1560 skb->protocol == htons(ETH_P_IP) && 1561 (IN_DEV_SHARED_MEDIA(out_dev) || 1562 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1563 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1564 1565 if (skb->protocol != htons(ETH_P_IP)) { 1566 /* Not IP (i.e. ARP). Do not create route, if it is 1567 * invalid for proxy arp. DNAT routes are always valid. 1568 * 1569 * Proxy arp feature have been extended to allow, ARP 1570 * replies back to the same interface, to support 1571 * Private VLAN switch technologies. See arp.c. 1572 */ 1573 if (out_dev == in_dev && 1574 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1575 err = -EINVAL; 1576 goto cleanup; 1577 } 1578 } 1579 1580 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1581 if (do_cache) { 1582 if (fnhe != NULL) 1583 rth = rcu_dereference(fnhe->fnhe_rth_input); 1584 else 1585 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1586 1587 if (rt_cache_valid(rth)) { 1588 skb_dst_set_noref(skb, &rth->dst); 1589 goto out; 1590 } 1591 } 1592 1593 rth = rt_dst_alloc(out_dev->dev, 1594 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1595 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1596 if (!rth) { 1597 err = -ENOBUFS; 1598 goto cleanup; 1599 } 1600 1601 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev)); 1602 rth->rt_flags = flags; 1603 rth->rt_type = res->type; 1604 rth->rt_is_input = 1; 1605 rth->rt_iif = 0; 1606 rth->rt_pmtu = 0; 1607 rth->rt_gateway = 0; 1608 rth->rt_uses_gateway = 0; 1609 INIT_LIST_HEAD(&rth->rt_uncached); 1610 RT_CACHE_STAT_INC(in_slow_tot); 1611 1612 rth->dst.input = ip_forward; 1613 rth->dst.output = ip_output; 1614 1615 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); 1616 skb_dst_set(skb, &rth->dst); 1617 out: 1618 err = 0; 1619 cleanup: 1620 return err; 1621 } 1622 1623 static int ip_mkroute_input(struct sk_buff *skb, 1624 struct fib_result *res, 1625 const struct flowi4 *fl4, 1626 struct in_device *in_dev, 1627 __be32 daddr, __be32 saddr, u32 tos) 1628 { 1629 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1630 if (res->fi && res->fi->fib_nhs > 1) 1631 fib_select_multipath(res); 1632 #endif 1633 1634 /* create a routing cache entry */ 1635 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1636 } 1637 1638 /* 1639 * NOTE. We drop all the packets that has local source 1640 * addresses, because every properly looped back packet 1641 * must have correct destination already attached by output routine. 1642 * 1643 * Such approach solves two big problems: 1644 * 1. Not simplex devices are handled properly. 1645 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1646 * called with rcu_read_lock() 1647 */ 1648 1649 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1650 u8 tos, struct net_device *dev) 1651 { 1652 struct fib_result res; 1653 struct in_device *in_dev = __in_dev_get_rcu(dev); 1654 struct flowi4 fl4; 1655 unsigned int flags = 0; 1656 u32 itag = 0; 1657 struct rtable *rth; 1658 int err = -EINVAL; 1659 struct net *net = dev_net(dev); 1660 bool do_cache; 1661 1662 /* IP on this device is disabled. */ 1663 1664 if (!in_dev) 1665 goto out; 1666 1667 /* Check for the most weird martians, which can be not detected 1668 by fib_lookup. 1669 */ 1670 1671 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1672 goto martian_source; 1673 1674 res.fi = NULL; 1675 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1676 goto brd_input; 1677 1678 /* Accept zero addresses only to limited broadcast; 1679 * I even do not know to fix it or not. Waiting for complains :-) 1680 */ 1681 if (ipv4_is_zeronet(saddr)) 1682 goto martian_source; 1683 1684 if (ipv4_is_zeronet(daddr)) 1685 goto martian_destination; 1686 1687 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1688 * and call it once if daddr or/and saddr are loopback addresses 1689 */ 1690 if (ipv4_is_loopback(daddr)) { 1691 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1692 goto martian_destination; 1693 } else if (ipv4_is_loopback(saddr)) { 1694 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1695 goto martian_source; 1696 } 1697 1698 /* 1699 * Now we are ready to route packet. 1700 */ 1701 fl4.flowi4_oif = 0; 1702 fl4.flowi4_iif = dev->ifindex; 1703 fl4.flowi4_mark = skb->mark; 1704 fl4.flowi4_tos = tos; 1705 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1706 fl4.daddr = daddr; 1707 fl4.saddr = saddr; 1708 err = fib_lookup(net, &fl4, &res); 1709 if (err != 0) { 1710 if (!IN_DEV_FORWARD(in_dev)) 1711 err = -EHOSTUNREACH; 1712 goto no_route; 1713 } 1714 1715 if (res.type == RTN_BROADCAST) 1716 goto brd_input; 1717 1718 if (res.type == RTN_LOCAL) { 1719 err = fib_validate_source(skb, saddr, daddr, tos, 1720 0, dev, in_dev, &itag); 1721 if (err < 0) 1722 goto martian_source_keep_err; 1723 goto local_input; 1724 } 1725 1726 if (!IN_DEV_FORWARD(in_dev)) { 1727 err = -EHOSTUNREACH; 1728 goto no_route; 1729 } 1730 if (res.type != RTN_UNICAST) 1731 goto martian_destination; 1732 1733 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1734 out: return err; 1735 1736 brd_input: 1737 if (skb->protocol != htons(ETH_P_IP)) 1738 goto e_inval; 1739 1740 if (!ipv4_is_zeronet(saddr)) { 1741 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1742 in_dev, &itag); 1743 if (err < 0) 1744 goto martian_source_keep_err; 1745 } 1746 flags |= RTCF_BROADCAST; 1747 res.type = RTN_BROADCAST; 1748 RT_CACHE_STAT_INC(in_brd); 1749 1750 local_input: 1751 do_cache = false; 1752 if (res.fi) { 1753 if (!itag) { 1754 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1755 if (rt_cache_valid(rth)) { 1756 skb_dst_set_noref(skb, &rth->dst); 1757 err = 0; 1758 goto out; 1759 } 1760 do_cache = true; 1761 } 1762 } 1763 1764 rth = rt_dst_alloc(net->loopback_dev, 1765 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1766 if (!rth) 1767 goto e_nobufs; 1768 1769 rth->dst.input= ip_local_deliver; 1770 rth->dst.output= ip_rt_bug; 1771 #ifdef CONFIG_IP_ROUTE_CLASSID 1772 rth->dst.tclassid = itag; 1773 #endif 1774 1775 rth->rt_genid = rt_genid_ipv4(net); 1776 rth->rt_flags = flags|RTCF_LOCAL; 1777 rth->rt_type = res.type; 1778 rth->rt_is_input = 1; 1779 rth->rt_iif = 0; 1780 rth->rt_pmtu = 0; 1781 rth->rt_gateway = 0; 1782 rth->rt_uses_gateway = 0; 1783 INIT_LIST_HEAD(&rth->rt_uncached); 1784 RT_CACHE_STAT_INC(in_slow_tot); 1785 if (res.type == RTN_UNREACHABLE) { 1786 rth->dst.input= ip_error; 1787 rth->dst.error= -err; 1788 rth->rt_flags &= ~RTCF_LOCAL; 1789 } 1790 if (do_cache) { 1791 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { 1792 rth->dst.flags |= DST_NOCACHE; 1793 rt_add_uncached_list(rth); 1794 } 1795 } 1796 skb_dst_set(skb, &rth->dst); 1797 err = 0; 1798 goto out; 1799 1800 no_route: 1801 RT_CACHE_STAT_INC(in_no_route); 1802 res.type = RTN_UNREACHABLE; 1803 res.fi = NULL; 1804 goto local_input; 1805 1806 /* 1807 * Do not cache martian addresses: they should be logged (RFC1812) 1808 */ 1809 martian_destination: 1810 RT_CACHE_STAT_INC(in_martian_dst); 1811 #ifdef CONFIG_IP_ROUTE_VERBOSE 1812 if (IN_DEV_LOG_MARTIANS(in_dev)) 1813 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1814 &daddr, &saddr, dev->name); 1815 #endif 1816 1817 e_inval: 1818 err = -EINVAL; 1819 goto out; 1820 1821 e_nobufs: 1822 err = -ENOBUFS; 1823 goto out; 1824 1825 martian_source: 1826 err = -EINVAL; 1827 martian_source_keep_err: 1828 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1829 goto out; 1830 } 1831 1832 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1833 u8 tos, struct net_device *dev) 1834 { 1835 int res; 1836 1837 rcu_read_lock(); 1838 1839 /* Multicast recognition logic is moved from route cache to here. 1840 The problem was that too many Ethernet cards have broken/missing 1841 hardware multicast filters :-( As result the host on multicasting 1842 network acquires a lot of useless route cache entries, sort of 1843 SDR messages from all the world. Now we try to get rid of them. 1844 Really, provided software IP multicast filter is organized 1845 reasonably (at least, hashed), it does not result in a slowdown 1846 comparing with route cache reject entries. 1847 Note, that multicast routers are not affected, because 1848 route cache entry is created eventually. 1849 */ 1850 if (ipv4_is_multicast(daddr)) { 1851 struct in_device *in_dev = __in_dev_get_rcu(dev); 1852 1853 if (in_dev) { 1854 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1855 ip_hdr(skb)->protocol); 1856 if (our 1857 #ifdef CONFIG_IP_MROUTE 1858 || 1859 (!ipv4_is_local_multicast(daddr) && 1860 IN_DEV_MFORWARD(in_dev)) 1861 #endif 1862 ) { 1863 int res = ip_route_input_mc(skb, daddr, saddr, 1864 tos, dev, our); 1865 rcu_read_unlock(); 1866 return res; 1867 } 1868 } 1869 rcu_read_unlock(); 1870 return -EINVAL; 1871 } 1872 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1873 rcu_read_unlock(); 1874 return res; 1875 } 1876 EXPORT_SYMBOL(ip_route_input_noref); 1877 1878 /* called with rcu_read_lock() */ 1879 static struct rtable *__mkroute_output(const struct fib_result *res, 1880 const struct flowi4 *fl4, int orig_oif, 1881 struct net_device *dev_out, 1882 unsigned int flags) 1883 { 1884 struct fib_info *fi = res->fi; 1885 struct fib_nh_exception *fnhe; 1886 struct in_device *in_dev; 1887 u16 type = res->type; 1888 struct rtable *rth; 1889 bool do_cache; 1890 1891 in_dev = __in_dev_get_rcu(dev_out); 1892 if (!in_dev) 1893 return ERR_PTR(-EINVAL); 1894 1895 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1896 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1897 return ERR_PTR(-EINVAL); 1898 1899 if (ipv4_is_lbcast(fl4->daddr)) 1900 type = RTN_BROADCAST; 1901 else if (ipv4_is_multicast(fl4->daddr)) 1902 type = RTN_MULTICAST; 1903 else if (ipv4_is_zeronet(fl4->daddr)) 1904 return ERR_PTR(-EINVAL); 1905 1906 if (dev_out->flags & IFF_LOOPBACK) 1907 flags |= RTCF_LOCAL; 1908 1909 do_cache = true; 1910 if (type == RTN_BROADCAST) { 1911 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1912 fi = NULL; 1913 } else if (type == RTN_MULTICAST) { 1914 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1915 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1916 fl4->flowi4_proto)) 1917 flags &= ~RTCF_LOCAL; 1918 else 1919 do_cache = false; 1920 /* If multicast route do not exist use 1921 * default one, but do not gateway in this case. 1922 * Yes, it is hack. 1923 */ 1924 if (fi && res->prefixlen < 4) 1925 fi = NULL; 1926 } 1927 1928 fnhe = NULL; 1929 do_cache &= fi != NULL; 1930 if (do_cache) { 1931 struct rtable __rcu **prth; 1932 struct fib_nh *nh = &FIB_RES_NH(*res); 1933 1934 fnhe = find_exception(nh, fl4->daddr); 1935 if (fnhe) 1936 prth = &fnhe->fnhe_rth_output; 1937 else { 1938 if (unlikely(fl4->flowi4_flags & 1939 FLOWI_FLAG_KNOWN_NH && 1940 !(nh->nh_gw && 1941 nh->nh_scope == RT_SCOPE_LINK))) { 1942 do_cache = false; 1943 goto add; 1944 } 1945 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 1946 } 1947 rth = rcu_dereference(*prth); 1948 if (rt_cache_valid(rth)) { 1949 dst_hold(&rth->dst); 1950 return rth; 1951 } 1952 } 1953 1954 add: 1955 rth = rt_dst_alloc(dev_out, 1956 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1957 IN_DEV_CONF_GET(in_dev, NOXFRM), 1958 do_cache); 1959 if (!rth) 1960 return ERR_PTR(-ENOBUFS); 1961 1962 rth->dst.output = ip_output; 1963 1964 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out)); 1965 rth->rt_flags = flags; 1966 rth->rt_type = type; 1967 rth->rt_is_input = 0; 1968 rth->rt_iif = orig_oif ? : 0; 1969 rth->rt_pmtu = 0; 1970 rth->rt_gateway = 0; 1971 rth->rt_uses_gateway = 0; 1972 INIT_LIST_HEAD(&rth->rt_uncached); 1973 1974 RT_CACHE_STAT_INC(out_slow_tot); 1975 1976 if (flags & RTCF_LOCAL) 1977 rth->dst.input = ip_local_deliver; 1978 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 1979 if (flags & RTCF_LOCAL && 1980 !(dev_out->flags & IFF_LOOPBACK)) { 1981 rth->dst.output = ip_mc_output; 1982 RT_CACHE_STAT_INC(out_slow_mc); 1983 } 1984 #ifdef CONFIG_IP_MROUTE 1985 if (type == RTN_MULTICAST) { 1986 if (IN_DEV_MFORWARD(in_dev) && 1987 !ipv4_is_local_multicast(fl4->daddr)) { 1988 rth->dst.input = ip_mr_input; 1989 rth->dst.output = ip_mc_output; 1990 } 1991 } 1992 #endif 1993 } 1994 1995 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 1996 1997 return rth; 1998 } 1999 2000 /* 2001 * Major route resolver routine. 2002 */ 2003 2004 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 2005 { 2006 struct net_device *dev_out = NULL; 2007 __u8 tos = RT_FL_TOS(fl4); 2008 unsigned int flags = 0; 2009 struct fib_result res; 2010 struct rtable *rth; 2011 int orig_oif; 2012 2013 res.tclassid = 0; 2014 res.fi = NULL; 2015 res.table = NULL; 2016 2017 orig_oif = fl4->flowi4_oif; 2018 2019 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2020 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2021 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2022 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2023 2024 rcu_read_lock(); 2025 if (fl4->saddr) { 2026 rth = ERR_PTR(-EINVAL); 2027 if (ipv4_is_multicast(fl4->saddr) || 2028 ipv4_is_lbcast(fl4->saddr) || 2029 ipv4_is_zeronet(fl4->saddr)) 2030 goto out; 2031 2032 /* I removed check for oif == dev_out->oif here. 2033 It was wrong for two reasons: 2034 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2035 is assigned to multiple interfaces. 2036 2. Moreover, we are allowed to send packets with saddr 2037 of another iface. --ANK 2038 */ 2039 2040 if (fl4->flowi4_oif == 0 && 2041 (ipv4_is_multicast(fl4->daddr) || 2042 ipv4_is_lbcast(fl4->daddr))) { 2043 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2044 dev_out = __ip_dev_find(net, fl4->saddr, false); 2045 if (dev_out == NULL) 2046 goto out; 2047 2048 /* Special hack: user can direct multicasts 2049 and limited broadcast via necessary interface 2050 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2051 This hack is not just for fun, it allows 2052 vic,vat and friends to work. 2053 They bind socket to loopback, set ttl to zero 2054 and expect that it will work. 2055 From the viewpoint of routing cache they are broken, 2056 because we are not allowed to build multicast path 2057 with loopback source addr (look, routing cache 2058 cannot know, that ttl is zero, so that packet 2059 will not leave this host and route is valid). 2060 Luckily, this hack is good workaround. 2061 */ 2062 2063 fl4->flowi4_oif = dev_out->ifindex; 2064 goto make_route; 2065 } 2066 2067 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2068 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2069 if (!__ip_dev_find(net, fl4->saddr, false)) 2070 goto out; 2071 } 2072 } 2073 2074 2075 if (fl4->flowi4_oif) { 2076 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2077 rth = ERR_PTR(-ENODEV); 2078 if (dev_out == NULL) 2079 goto out; 2080 2081 /* RACE: Check return value of inet_select_addr instead. */ 2082 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2083 rth = ERR_PTR(-ENETUNREACH); 2084 goto out; 2085 } 2086 if (ipv4_is_local_multicast(fl4->daddr) || 2087 ipv4_is_lbcast(fl4->daddr)) { 2088 if (!fl4->saddr) 2089 fl4->saddr = inet_select_addr(dev_out, 0, 2090 RT_SCOPE_LINK); 2091 goto make_route; 2092 } 2093 if (!fl4->saddr) { 2094 if (ipv4_is_multicast(fl4->daddr)) 2095 fl4->saddr = inet_select_addr(dev_out, 0, 2096 fl4->flowi4_scope); 2097 else if (!fl4->daddr) 2098 fl4->saddr = inet_select_addr(dev_out, 0, 2099 RT_SCOPE_HOST); 2100 } 2101 } 2102 2103 if (!fl4->daddr) { 2104 fl4->daddr = fl4->saddr; 2105 if (!fl4->daddr) 2106 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2107 dev_out = net->loopback_dev; 2108 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2109 res.type = RTN_LOCAL; 2110 flags |= RTCF_LOCAL; 2111 goto make_route; 2112 } 2113 2114 if (fib_lookup(net, fl4, &res)) { 2115 res.fi = NULL; 2116 res.table = NULL; 2117 if (fl4->flowi4_oif) { 2118 /* Apparently, routing tables are wrong. Assume, 2119 that the destination is on link. 2120 2121 WHY? DW. 2122 Because we are allowed to send to iface 2123 even if it has NO routes and NO assigned 2124 addresses. When oif is specified, routing 2125 tables are looked up with only one purpose: 2126 to catch if destination is gatewayed, rather than 2127 direct. Moreover, if MSG_DONTROUTE is set, 2128 we send packet, ignoring both routing tables 2129 and ifaddr state. --ANK 2130 2131 2132 We could make it even if oif is unknown, 2133 likely IPv6, but we do not. 2134 */ 2135 2136 if (fl4->saddr == 0) 2137 fl4->saddr = inet_select_addr(dev_out, 0, 2138 RT_SCOPE_LINK); 2139 res.type = RTN_UNICAST; 2140 goto make_route; 2141 } 2142 rth = ERR_PTR(-ENETUNREACH); 2143 goto out; 2144 } 2145 2146 if (res.type == RTN_LOCAL) { 2147 if (!fl4->saddr) { 2148 if (res.fi->fib_prefsrc) 2149 fl4->saddr = res.fi->fib_prefsrc; 2150 else 2151 fl4->saddr = fl4->daddr; 2152 } 2153 dev_out = net->loopback_dev; 2154 fl4->flowi4_oif = dev_out->ifindex; 2155 flags |= RTCF_LOCAL; 2156 goto make_route; 2157 } 2158 2159 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2160 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2161 fib_select_multipath(&res); 2162 else 2163 #endif 2164 if (!res.prefixlen && 2165 res.table->tb_num_default > 1 && 2166 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2167 fib_select_default(&res); 2168 2169 if (!fl4->saddr) 2170 fl4->saddr = FIB_RES_PREFSRC(net, res); 2171 2172 dev_out = FIB_RES_DEV(res); 2173 fl4->flowi4_oif = dev_out->ifindex; 2174 2175 2176 make_route: 2177 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2178 2179 out: 2180 rcu_read_unlock(); 2181 return rth; 2182 } 2183 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2184 2185 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2186 { 2187 return NULL; 2188 } 2189 2190 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2191 { 2192 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2193 2194 return mtu ? : dst->dev->mtu; 2195 } 2196 2197 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2198 struct sk_buff *skb, u32 mtu) 2199 { 2200 } 2201 2202 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2203 struct sk_buff *skb) 2204 { 2205 } 2206 2207 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2208 unsigned long old) 2209 { 2210 return NULL; 2211 } 2212 2213 static struct dst_ops ipv4_dst_blackhole_ops = { 2214 .family = AF_INET, 2215 .protocol = cpu_to_be16(ETH_P_IP), 2216 .check = ipv4_blackhole_dst_check, 2217 .mtu = ipv4_blackhole_mtu, 2218 .default_advmss = ipv4_default_advmss, 2219 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2220 .redirect = ipv4_rt_blackhole_redirect, 2221 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2222 .neigh_lookup = ipv4_neigh_lookup, 2223 }; 2224 2225 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2226 { 2227 struct rtable *ort = (struct rtable *) dst_orig; 2228 struct rtable *rt; 2229 2230 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2231 if (rt) { 2232 struct dst_entry *new = &rt->dst; 2233 2234 new->__use = 1; 2235 new->input = dst_discard; 2236 new->output = dst_discard_sk; 2237 2238 new->dev = ort->dst.dev; 2239 if (new->dev) 2240 dev_hold(new->dev); 2241 2242 rt->rt_is_input = ort->rt_is_input; 2243 rt->rt_iif = ort->rt_iif; 2244 rt->rt_pmtu = ort->rt_pmtu; 2245 2246 rt->rt_genid = rt_genid_ipv4(net); 2247 rt->rt_flags = ort->rt_flags; 2248 rt->rt_type = ort->rt_type; 2249 rt->rt_gateway = ort->rt_gateway; 2250 rt->rt_uses_gateway = ort->rt_uses_gateway; 2251 2252 INIT_LIST_HEAD(&rt->rt_uncached); 2253 2254 dst_free(new); 2255 } 2256 2257 dst_release(dst_orig); 2258 2259 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2260 } 2261 2262 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2263 struct sock *sk) 2264 { 2265 struct rtable *rt = __ip_route_output_key(net, flp4); 2266 2267 if (IS_ERR(rt)) 2268 return rt; 2269 2270 if (flp4->flowi4_proto) 2271 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2272 flowi4_to_flowi(flp4), 2273 sk, 0); 2274 2275 return rt; 2276 } 2277 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2278 2279 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2280 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2281 u32 seq, int event, int nowait, unsigned int flags) 2282 { 2283 struct rtable *rt = skb_rtable(skb); 2284 struct rtmsg *r; 2285 struct nlmsghdr *nlh; 2286 unsigned long expires = 0; 2287 u32 error; 2288 u32 metrics[RTAX_MAX]; 2289 2290 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2291 if (nlh == NULL) 2292 return -EMSGSIZE; 2293 2294 r = nlmsg_data(nlh); 2295 r->rtm_family = AF_INET; 2296 r->rtm_dst_len = 32; 2297 r->rtm_src_len = 0; 2298 r->rtm_tos = fl4->flowi4_tos; 2299 r->rtm_table = RT_TABLE_MAIN; 2300 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) 2301 goto nla_put_failure; 2302 r->rtm_type = rt->rt_type; 2303 r->rtm_scope = RT_SCOPE_UNIVERSE; 2304 r->rtm_protocol = RTPROT_UNSPEC; 2305 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2306 if (rt->rt_flags & RTCF_NOTIFY) 2307 r->rtm_flags |= RTM_F_NOTIFY; 2308 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2309 r->rtm_flags |= RTCF_DOREDIRECT; 2310 2311 if (nla_put_be32(skb, RTA_DST, dst)) 2312 goto nla_put_failure; 2313 if (src) { 2314 r->rtm_src_len = 32; 2315 if (nla_put_be32(skb, RTA_SRC, src)) 2316 goto nla_put_failure; 2317 } 2318 if (rt->dst.dev && 2319 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2320 goto nla_put_failure; 2321 #ifdef CONFIG_IP_ROUTE_CLASSID 2322 if (rt->dst.tclassid && 2323 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2324 goto nla_put_failure; 2325 #endif 2326 if (!rt_is_input_route(rt) && 2327 fl4->saddr != src) { 2328 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr)) 2329 goto nla_put_failure; 2330 } 2331 if (rt->rt_uses_gateway && 2332 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway)) 2333 goto nla_put_failure; 2334 2335 expires = rt->dst.expires; 2336 if (expires) { 2337 unsigned long now = jiffies; 2338 2339 if (time_before(now, expires)) 2340 expires -= now; 2341 else 2342 expires = 0; 2343 } 2344 2345 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2346 if (rt->rt_pmtu && expires) 2347 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2348 if (rtnetlink_put_metrics(skb, metrics) < 0) 2349 goto nla_put_failure; 2350 2351 if (fl4->flowi4_mark && 2352 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2353 goto nla_put_failure; 2354 2355 error = rt->dst.error; 2356 2357 if (rt_is_input_route(rt)) { 2358 #ifdef CONFIG_IP_MROUTE 2359 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2360 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2361 int err = ipmr_get_route(net, skb, 2362 fl4->saddr, fl4->daddr, 2363 r, nowait); 2364 if (err <= 0) { 2365 if (!nowait) { 2366 if (err == 0) 2367 return 0; 2368 goto nla_put_failure; 2369 } else { 2370 if (err == -EMSGSIZE) 2371 goto nla_put_failure; 2372 error = err; 2373 } 2374 } 2375 } else 2376 #endif 2377 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) 2378 goto nla_put_failure; 2379 } 2380 2381 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2382 goto nla_put_failure; 2383 2384 return nlmsg_end(skb, nlh); 2385 2386 nla_put_failure: 2387 nlmsg_cancel(skb, nlh); 2388 return -EMSGSIZE; 2389 } 2390 2391 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 2392 { 2393 struct net *net = sock_net(in_skb->sk); 2394 struct rtmsg *rtm; 2395 struct nlattr *tb[RTA_MAX+1]; 2396 struct rtable *rt = NULL; 2397 struct flowi4 fl4; 2398 __be32 dst = 0; 2399 __be32 src = 0; 2400 u32 iif; 2401 int err; 2402 int mark; 2403 struct sk_buff *skb; 2404 2405 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2406 if (err < 0) 2407 goto errout; 2408 2409 rtm = nlmsg_data(nlh); 2410 2411 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2412 if (skb == NULL) { 2413 err = -ENOBUFS; 2414 goto errout; 2415 } 2416 2417 /* Reserve room for dummy headers, this skb can pass 2418 through good chunk of routing engine. 2419 */ 2420 skb_reset_mac_header(skb); 2421 skb_reset_network_header(skb); 2422 2423 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2424 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2425 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2426 2427 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2428 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2429 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2430 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2431 2432 memset(&fl4, 0, sizeof(fl4)); 2433 fl4.daddr = dst; 2434 fl4.saddr = src; 2435 fl4.flowi4_tos = rtm->rtm_tos; 2436 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2437 fl4.flowi4_mark = mark; 2438 2439 if (iif) { 2440 struct net_device *dev; 2441 2442 dev = __dev_get_by_index(net, iif); 2443 if (dev == NULL) { 2444 err = -ENODEV; 2445 goto errout_free; 2446 } 2447 2448 skb->protocol = htons(ETH_P_IP); 2449 skb->dev = dev; 2450 skb->mark = mark; 2451 local_bh_disable(); 2452 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2453 local_bh_enable(); 2454 2455 rt = skb_rtable(skb); 2456 if (err == 0 && rt->dst.error) 2457 err = -rt->dst.error; 2458 } else { 2459 rt = ip_route_output_key(net, &fl4); 2460 2461 err = 0; 2462 if (IS_ERR(rt)) 2463 err = PTR_ERR(rt); 2464 } 2465 2466 if (err) 2467 goto errout_free; 2468 2469 skb_dst_set(skb, &rt->dst); 2470 if (rtm->rtm_flags & RTM_F_NOTIFY) 2471 rt->rt_flags |= RTCF_NOTIFY; 2472 2473 err = rt_fill_info(net, dst, src, &fl4, skb, 2474 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2475 RTM_NEWROUTE, 0, 0); 2476 if (err <= 0) 2477 goto errout_free; 2478 2479 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2480 errout: 2481 return err; 2482 2483 errout_free: 2484 kfree_skb(skb); 2485 goto errout; 2486 } 2487 2488 void ip_rt_multicast_event(struct in_device *in_dev) 2489 { 2490 rt_cache_flush(dev_net(in_dev->dev)); 2491 } 2492 2493 #ifdef CONFIG_SYSCTL 2494 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2495 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2496 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2497 static int ip_rt_gc_elasticity __read_mostly = 8; 2498 2499 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2500 void __user *buffer, 2501 size_t *lenp, loff_t *ppos) 2502 { 2503 struct net *net = (struct net *)__ctl->extra1; 2504 2505 if (write) { 2506 rt_cache_flush(net); 2507 fnhe_genid_bump(net); 2508 return 0; 2509 } 2510 2511 return -EINVAL; 2512 } 2513 2514 static struct ctl_table ipv4_route_table[] = { 2515 { 2516 .procname = "gc_thresh", 2517 .data = &ipv4_dst_ops.gc_thresh, 2518 .maxlen = sizeof(int), 2519 .mode = 0644, 2520 .proc_handler = proc_dointvec, 2521 }, 2522 { 2523 .procname = "max_size", 2524 .data = &ip_rt_max_size, 2525 .maxlen = sizeof(int), 2526 .mode = 0644, 2527 .proc_handler = proc_dointvec, 2528 }, 2529 { 2530 /* Deprecated. Use gc_min_interval_ms */ 2531 2532 .procname = "gc_min_interval", 2533 .data = &ip_rt_gc_min_interval, 2534 .maxlen = sizeof(int), 2535 .mode = 0644, 2536 .proc_handler = proc_dointvec_jiffies, 2537 }, 2538 { 2539 .procname = "gc_min_interval_ms", 2540 .data = &ip_rt_gc_min_interval, 2541 .maxlen = sizeof(int), 2542 .mode = 0644, 2543 .proc_handler = proc_dointvec_ms_jiffies, 2544 }, 2545 { 2546 .procname = "gc_timeout", 2547 .data = &ip_rt_gc_timeout, 2548 .maxlen = sizeof(int), 2549 .mode = 0644, 2550 .proc_handler = proc_dointvec_jiffies, 2551 }, 2552 { 2553 .procname = "gc_interval", 2554 .data = &ip_rt_gc_interval, 2555 .maxlen = sizeof(int), 2556 .mode = 0644, 2557 .proc_handler = proc_dointvec_jiffies, 2558 }, 2559 { 2560 .procname = "redirect_load", 2561 .data = &ip_rt_redirect_load, 2562 .maxlen = sizeof(int), 2563 .mode = 0644, 2564 .proc_handler = proc_dointvec, 2565 }, 2566 { 2567 .procname = "redirect_number", 2568 .data = &ip_rt_redirect_number, 2569 .maxlen = sizeof(int), 2570 .mode = 0644, 2571 .proc_handler = proc_dointvec, 2572 }, 2573 { 2574 .procname = "redirect_silence", 2575 .data = &ip_rt_redirect_silence, 2576 .maxlen = sizeof(int), 2577 .mode = 0644, 2578 .proc_handler = proc_dointvec, 2579 }, 2580 { 2581 .procname = "error_cost", 2582 .data = &ip_rt_error_cost, 2583 .maxlen = sizeof(int), 2584 .mode = 0644, 2585 .proc_handler = proc_dointvec, 2586 }, 2587 { 2588 .procname = "error_burst", 2589 .data = &ip_rt_error_burst, 2590 .maxlen = sizeof(int), 2591 .mode = 0644, 2592 .proc_handler = proc_dointvec, 2593 }, 2594 { 2595 .procname = "gc_elasticity", 2596 .data = &ip_rt_gc_elasticity, 2597 .maxlen = sizeof(int), 2598 .mode = 0644, 2599 .proc_handler = proc_dointvec, 2600 }, 2601 { 2602 .procname = "mtu_expires", 2603 .data = &ip_rt_mtu_expires, 2604 .maxlen = sizeof(int), 2605 .mode = 0644, 2606 .proc_handler = proc_dointvec_jiffies, 2607 }, 2608 { 2609 .procname = "min_pmtu", 2610 .data = &ip_rt_min_pmtu, 2611 .maxlen = sizeof(int), 2612 .mode = 0644, 2613 .proc_handler = proc_dointvec, 2614 }, 2615 { 2616 .procname = "min_adv_mss", 2617 .data = &ip_rt_min_advmss, 2618 .maxlen = sizeof(int), 2619 .mode = 0644, 2620 .proc_handler = proc_dointvec, 2621 }, 2622 { } 2623 }; 2624 2625 static struct ctl_table ipv4_route_flush_table[] = { 2626 { 2627 .procname = "flush", 2628 .maxlen = sizeof(int), 2629 .mode = 0200, 2630 .proc_handler = ipv4_sysctl_rtcache_flush, 2631 }, 2632 { }, 2633 }; 2634 2635 static __net_init int sysctl_route_net_init(struct net *net) 2636 { 2637 struct ctl_table *tbl; 2638 2639 tbl = ipv4_route_flush_table; 2640 if (!net_eq(net, &init_net)) { 2641 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2642 if (tbl == NULL) 2643 goto err_dup; 2644 2645 /* Don't export sysctls to unprivileged users */ 2646 if (net->user_ns != &init_user_ns) 2647 tbl[0].procname = NULL; 2648 } 2649 tbl[0].extra1 = net; 2650 2651 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2652 if (net->ipv4.route_hdr == NULL) 2653 goto err_reg; 2654 return 0; 2655 2656 err_reg: 2657 if (tbl != ipv4_route_flush_table) 2658 kfree(tbl); 2659 err_dup: 2660 return -ENOMEM; 2661 } 2662 2663 static __net_exit void sysctl_route_net_exit(struct net *net) 2664 { 2665 struct ctl_table *tbl; 2666 2667 tbl = net->ipv4.route_hdr->ctl_table_arg; 2668 unregister_net_sysctl_table(net->ipv4.route_hdr); 2669 BUG_ON(tbl == ipv4_route_flush_table); 2670 kfree(tbl); 2671 } 2672 2673 static __net_initdata struct pernet_operations sysctl_route_ops = { 2674 .init = sysctl_route_net_init, 2675 .exit = sysctl_route_net_exit, 2676 }; 2677 #endif 2678 2679 static __net_init int rt_genid_init(struct net *net) 2680 { 2681 atomic_set(&net->ipv4.rt_genid, 0); 2682 atomic_set(&net->fnhe_genid, 0); 2683 get_random_bytes(&net->ipv4.dev_addr_genid, 2684 sizeof(net->ipv4.dev_addr_genid)); 2685 return 0; 2686 } 2687 2688 static __net_initdata struct pernet_operations rt_genid_ops = { 2689 .init = rt_genid_init, 2690 }; 2691 2692 static int __net_init ipv4_inetpeer_init(struct net *net) 2693 { 2694 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2695 2696 if (!bp) 2697 return -ENOMEM; 2698 inet_peer_base_init(bp); 2699 net->ipv4.peers = bp; 2700 return 0; 2701 } 2702 2703 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2704 { 2705 struct inet_peer_base *bp = net->ipv4.peers; 2706 2707 net->ipv4.peers = NULL; 2708 inetpeer_invalidate_tree(bp); 2709 kfree(bp); 2710 } 2711 2712 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2713 .init = ipv4_inetpeer_init, 2714 .exit = ipv4_inetpeer_exit, 2715 }; 2716 2717 #ifdef CONFIG_IP_ROUTE_CLASSID 2718 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2719 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2720 2721 int __init ip_rt_init(void) 2722 { 2723 int rc = 0; 2724 2725 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); 2726 if (!ip_idents) 2727 panic("IP: failed to allocate ip_idents\n"); 2728 2729 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 2730 2731 #ifdef CONFIG_IP_ROUTE_CLASSID 2732 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2733 if (!ip_rt_acct) 2734 panic("IP: failed to allocate ip_rt_acct\n"); 2735 #endif 2736 2737 ipv4_dst_ops.kmem_cachep = 2738 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2739 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2740 2741 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2742 2743 if (dst_entries_init(&ipv4_dst_ops) < 0) 2744 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2745 2746 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2747 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2748 2749 ipv4_dst_ops.gc_thresh = ~0; 2750 ip_rt_max_size = INT_MAX; 2751 2752 devinet_init(); 2753 ip_fib_init(); 2754 2755 if (ip_rt_proc_init()) 2756 pr_err("Unable to create route proc files\n"); 2757 #ifdef CONFIG_XFRM 2758 xfrm_init(); 2759 xfrm4_init(); 2760 #endif 2761 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2762 2763 #ifdef CONFIG_SYSCTL 2764 register_pernet_subsys(&sysctl_route_ops); 2765 #endif 2766 register_pernet_subsys(&rt_genid_ops); 2767 register_pernet_subsys(&ipv4_inetpeer_ops); 2768 return rc; 2769 } 2770 2771 #ifdef CONFIG_SYSCTL 2772 /* 2773 * We really need to sanitize the damn ipv4 init order, then all 2774 * this nonsense will go away. 2775 */ 2776 void __init ip_static_sysctl_init(void) 2777 { 2778 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2779 } 2780 #endif 2781