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 (mtu < ip_rt_min_pmtu) 970 mtu = ip_rt_min_pmtu; 971 972 if (rt->rt_pmtu == mtu && 973 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 974 return; 975 976 rcu_read_lock(); 977 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) { 978 struct fib_nh *nh = &FIB_RES_NH(res); 979 980 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, 981 jiffies + ip_rt_mtu_expires); 982 } 983 rcu_read_unlock(); 984 } 985 986 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 987 struct sk_buff *skb, u32 mtu) 988 { 989 struct rtable *rt = (struct rtable *) dst; 990 struct flowi4 fl4; 991 992 ip_rt_build_flow_key(&fl4, sk, skb); 993 __ip_rt_update_pmtu(rt, &fl4, mtu); 994 } 995 996 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 997 int oif, u32 mark, u8 protocol, int flow_flags) 998 { 999 const struct iphdr *iph = (const struct iphdr *) skb->data; 1000 struct flowi4 fl4; 1001 struct rtable *rt; 1002 1003 if (!mark) 1004 mark = IP4_REPLY_MARK(net, skb->mark); 1005 1006 __build_flow_key(&fl4, NULL, iph, oif, 1007 RT_TOS(iph->tos), protocol, mark, flow_flags); 1008 rt = __ip_route_output_key(net, &fl4); 1009 if (!IS_ERR(rt)) { 1010 __ip_rt_update_pmtu(rt, &fl4, mtu); 1011 ip_rt_put(rt); 1012 } 1013 } 1014 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1015 1016 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1017 { 1018 const struct iphdr *iph = (const struct iphdr *) skb->data; 1019 struct flowi4 fl4; 1020 struct rtable *rt; 1021 1022 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1023 1024 if (!fl4.flowi4_mark) 1025 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1026 1027 rt = __ip_route_output_key(sock_net(sk), &fl4); 1028 if (!IS_ERR(rt)) { 1029 __ip_rt_update_pmtu(rt, &fl4, mtu); 1030 ip_rt_put(rt); 1031 } 1032 } 1033 1034 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1035 { 1036 const struct iphdr *iph = (const struct iphdr *) skb->data; 1037 struct flowi4 fl4; 1038 struct rtable *rt; 1039 struct dst_entry *odst = NULL; 1040 bool new = false; 1041 1042 bh_lock_sock(sk); 1043 1044 if (!ip_sk_accept_pmtu(sk)) 1045 goto out; 1046 1047 odst = sk_dst_get(sk); 1048 1049 if (sock_owned_by_user(sk) || !odst) { 1050 __ipv4_sk_update_pmtu(skb, sk, mtu); 1051 goto out; 1052 } 1053 1054 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1055 1056 rt = (struct rtable *)odst; 1057 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) { 1058 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1059 if (IS_ERR(rt)) 1060 goto out; 1061 1062 new = true; 1063 } 1064 1065 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); 1066 1067 if (!dst_check(&rt->dst, 0)) { 1068 if (new) 1069 dst_release(&rt->dst); 1070 1071 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1072 if (IS_ERR(rt)) 1073 goto out; 1074 1075 new = true; 1076 } 1077 1078 if (new) 1079 sk_dst_set(sk, &rt->dst); 1080 1081 out: 1082 bh_unlock_sock(sk); 1083 dst_release(odst); 1084 } 1085 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1086 1087 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1088 int oif, u32 mark, u8 protocol, int flow_flags) 1089 { 1090 const struct iphdr *iph = (const struct iphdr *) skb->data; 1091 struct flowi4 fl4; 1092 struct rtable *rt; 1093 1094 __build_flow_key(&fl4, NULL, iph, oif, 1095 RT_TOS(iph->tos), protocol, mark, flow_flags); 1096 rt = __ip_route_output_key(net, &fl4); 1097 if (!IS_ERR(rt)) { 1098 __ip_do_redirect(rt, skb, &fl4, false); 1099 ip_rt_put(rt); 1100 } 1101 } 1102 EXPORT_SYMBOL_GPL(ipv4_redirect); 1103 1104 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1105 { 1106 const struct iphdr *iph = (const struct iphdr *) skb->data; 1107 struct flowi4 fl4; 1108 struct rtable *rt; 1109 1110 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1111 rt = __ip_route_output_key(sock_net(sk), &fl4); 1112 if (!IS_ERR(rt)) { 1113 __ip_do_redirect(rt, skb, &fl4, false); 1114 ip_rt_put(rt); 1115 } 1116 } 1117 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1118 1119 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1120 { 1121 struct rtable *rt = (struct rtable *) dst; 1122 1123 /* All IPV4 dsts are created with ->obsolete set to the value 1124 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1125 * into this function always. 1126 * 1127 * When a PMTU/redirect information update invalidates a route, 1128 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1129 * DST_OBSOLETE_DEAD by dst_free(). 1130 */ 1131 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1132 return NULL; 1133 return dst; 1134 } 1135 1136 static void ipv4_link_failure(struct sk_buff *skb) 1137 { 1138 struct rtable *rt; 1139 1140 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1141 1142 rt = skb_rtable(skb); 1143 if (rt) 1144 dst_set_expires(&rt->dst, 0); 1145 } 1146 1147 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb) 1148 { 1149 pr_debug("%s: %pI4 -> %pI4, %s\n", 1150 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1151 skb->dev ? skb->dev->name : "?"); 1152 kfree_skb(skb); 1153 WARN_ON(1); 1154 return 0; 1155 } 1156 1157 /* 1158 We do not cache source address of outgoing interface, 1159 because it is used only by IP RR, TS and SRR options, 1160 so that it out of fast path. 1161 1162 BTW remember: "addr" is allowed to be not aligned 1163 in IP options! 1164 */ 1165 1166 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1167 { 1168 __be32 src; 1169 1170 if (rt_is_output_route(rt)) 1171 src = ip_hdr(skb)->saddr; 1172 else { 1173 struct fib_result res; 1174 struct flowi4 fl4; 1175 struct iphdr *iph; 1176 1177 iph = ip_hdr(skb); 1178 1179 memset(&fl4, 0, sizeof(fl4)); 1180 fl4.daddr = iph->daddr; 1181 fl4.saddr = iph->saddr; 1182 fl4.flowi4_tos = RT_TOS(iph->tos); 1183 fl4.flowi4_oif = rt->dst.dev->ifindex; 1184 fl4.flowi4_iif = skb->dev->ifindex; 1185 fl4.flowi4_mark = skb->mark; 1186 1187 rcu_read_lock(); 1188 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1189 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1190 else 1191 src = inet_select_addr(rt->dst.dev, 1192 rt_nexthop(rt, iph->daddr), 1193 RT_SCOPE_UNIVERSE); 1194 rcu_read_unlock(); 1195 } 1196 memcpy(addr, &src, 4); 1197 } 1198 1199 #ifdef CONFIG_IP_ROUTE_CLASSID 1200 static void set_class_tag(struct rtable *rt, u32 tag) 1201 { 1202 if (!(rt->dst.tclassid & 0xFFFF)) 1203 rt->dst.tclassid |= tag & 0xFFFF; 1204 if (!(rt->dst.tclassid & 0xFFFF0000)) 1205 rt->dst.tclassid |= tag & 0xFFFF0000; 1206 } 1207 #endif 1208 1209 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1210 { 1211 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1212 1213 if (advmss == 0) { 1214 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1215 ip_rt_min_advmss); 1216 if (advmss > 65535 - 40) 1217 advmss = 65535 - 40; 1218 } 1219 return advmss; 1220 } 1221 1222 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1223 { 1224 const struct rtable *rt = (const struct rtable *) dst; 1225 unsigned int mtu = rt->rt_pmtu; 1226 1227 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1228 mtu = dst_metric_raw(dst, RTAX_MTU); 1229 1230 if (mtu) 1231 return mtu; 1232 1233 mtu = dst->dev->mtu; 1234 1235 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1236 if (rt->rt_uses_gateway && mtu > 576) 1237 mtu = 576; 1238 } 1239 1240 return min_t(unsigned int, mtu, IP_MAX_MTU); 1241 } 1242 1243 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1244 { 1245 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1246 struct fib_nh_exception *fnhe; 1247 u32 hval; 1248 1249 if (!hash) 1250 return NULL; 1251 1252 hval = fnhe_hashfun(daddr); 1253 1254 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1255 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1256 if (fnhe->fnhe_daddr == daddr) 1257 return fnhe; 1258 } 1259 return NULL; 1260 } 1261 1262 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1263 __be32 daddr) 1264 { 1265 bool ret = false; 1266 1267 spin_lock_bh(&fnhe_lock); 1268 1269 if (daddr == fnhe->fnhe_daddr) { 1270 struct rtable __rcu **porig; 1271 struct rtable *orig; 1272 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1273 1274 if (rt_is_input_route(rt)) 1275 porig = &fnhe->fnhe_rth_input; 1276 else 1277 porig = &fnhe->fnhe_rth_output; 1278 orig = rcu_dereference(*porig); 1279 1280 if (fnhe->fnhe_genid != genid) { 1281 fnhe->fnhe_genid = genid; 1282 fnhe->fnhe_gw = 0; 1283 fnhe->fnhe_pmtu = 0; 1284 fnhe->fnhe_expires = 0; 1285 fnhe_flush_routes(fnhe); 1286 orig = NULL; 1287 } 1288 fill_route_from_fnhe(rt, fnhe); 1289 if (!rt->rt_gateway) 1290 rt->rt_gateway = daddr; 1291 1292 if (!(rt->dst.flags & DST_NOCACHE)) { 1293 rcu_assign_pointer(*porig, rt); 1294 if (orig) 1295 rt_free(orig); 1296 ret = true; 1297 } 1298 1299 fnhe->fnhe_stamp = jiffies; 1300 } 1301 spin_unlock_bh(&fnhe_lock); 1302 1303 return ret; 1304 } 1305 1306 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1307 { 1308 struct rtable *orig, *prev, **p; 1309 bool ret = true; 1310 1311 if (rt_is_input_route(rt)) { 1312 p = (struct rtable **)&nh->nh_rth_input; 1313 } else { 1314 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1315 } 1316 orig = *p; 1317 1318 prev = cmpxchg(p, orig, rt); 1319 if (prev == orig) { 1320 if (orig) 1321 rt_free(orig); 1322 } else 1323 ret = false; 1324 1325 return ret; 1326 } 1327 1328 static DEFINE_SPINLOCK(rt_uncached_lock); 1329 static LIST_HEAD(rt_uncached_list); 1330 1331 static void rt_add_uncached_list(struct rtable *rt) 1332 { 1333 spin_lock_bh(&rt_uncached_lock); 1334 list_add_tail(&rt->rt_uncached, &rt_uncached_list); 1335 spin_unlock_bh(&rt_uncached_lock); 1336 } 1337 1338 static void ipv4_dst_destroy(struct dst_entry *dst) 1339 { 1340 struct rtable *rt = (struct rtable *) dst; 1341 1342 if (!list_empty(&rt->rt_uncached)) { 1343 spin_lock_bh(&rt_uncached_lock); 1344 list_del(&rt->rt_uncached); 1345 spin_unlock_bh(&rt_uncached_lock); 1346 } 1347 } 1348 1349 void rt_flush_dev(struct net_device *dev) 1350 { 1351 if (!list_empty(&rt_uncached_list)) { 1352 struct net *net = dev_net(dev); 1353 struct rtable *rt; 1354 1355 spin_lock_bh(&rt_uncached_lock); 1356 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) { 1357 if (rt->dst.dev != dev) 1358 continue; 1359 rt->dst.dev = net->loopback_dev; 1360 dev_hold(rt->dst.dev); 1361 dev_put(dev); 1362 } 1363 spin_unlock_bh(&rt_uncached_lock); 1364 } 1365 } 1366 1367 static bool rt_cache_valid(const struct rtable *rt) 1368 { 1369 return rt && 1370 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1371 !rt_is_expired(rt); 1372 } 1373 1374 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1375 const struct fib_result *res, 1376 struct fib_nh_exception *fnhe, 1377 struct fib_info *fi, u16 type, u32 itag) 1378 { 1379 bool cached = false; 1380 1381 if (fi) { 1382 struct fib_nh *nh = &FIB_RES_NH(*res); 1383 1384 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1385 rt->rt_gateway = nh->nh_gw; 1386 rt->rt_uses_gateway = 1; 1387 } 1388 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1389 #ifdef CONFIG_IP_ROUTE_CLASSID 1390 rt->dst.tclassid = nh->nh_tclassid; 1391 #endif 1392 if (unlikely(fnhe)) 1393 cached = rt_bind_exception(rt, fnhe, daddr); 1394 else if (!(rt->dst.flags & DST_NOCACHE)) 1395 cached = rt_cache_route(nh, rt); 1396 if (unlikely(!cached)) { 1397 /* Routes we intend to cache in nexthop exception or 1398 * FIB nexthop have the DST_NOCACHE bit clear. 1399 * However, if we are unsuccessful at storing this 1400 * route into the cache we really need to set it. 1401 */ 1402 rt->dst.flags |= DST_NOCACHE; 1403 if (!rt->rt_gateway) 1404 rt->rt_gateway = daddr; 1405 rt_add_uncached_list(rt); 1406 } 1407 } else 1408 rt_add_uncached_list(rt); 1409 1410 #ifdef CONFIG_IP_ROUTE_CLASSID 1411 #ifdef CONFIG_IP_MULTIPLE_TABLES 1412 set_class_tag(rt, res->tclassid); 1413 #endif 1414 set_class_tag(rt, itag); 1415 #endif 1416 } 1417 1418 static struct rtable *rt_dst_alloc(struct net_device *dev, 1419 bool nopolicy, bool noxfrm, bool will_cache) 1420 { 1421 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1422 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1423 (nopolicy ? DST_NOPOLICY : 0) | 1424 (noxfrm ? DST_NOXFRM : 0)); 1425 } 1426 1427 /* called in rcu_read_lock() section */ 1428 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1429 u8 tos, struct net_device *dev, int our) 1430 { 1431 struct rtable *rth; 1432 struct in_device *in_dev = __in_dev_get_rcu(dev); 1433 u32 itag = 0; 1434 int err; 1435 1436 /* Primary sanity checks. */ 1437 1438 if (in_dev == NULL) 1439 return -EINVAL; 1440 1441 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1442 skb->protocol != htons(ETH_P_IP)) 1443 goto e_inval; 1444 1445 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1446 if (ipv4_is_loopback(saddr)) 1447 goto e_inval; 1448 1449 if (ipv4_is_zeronet(saddr)) { 1450 if (!ipv4_is_local_multicast(daddr)) 1451 goto e_inval; 1452 } else { 1453 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1454 in_dev, &itag); 1455 if (err < 0) 1456 goto e_err; 1457 } 1458 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, 1459 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1460 if (!rth) 1461 goto e_nobufs; 1462 1463 #ifdef CONFIG_IP_ROUTE_CLASSID 1464 rth->dst.tclassid = itag; 1465 #endif 1466 rth->dst.output = ip_rt_bug; 1467 1468 rth->rt_genid = rt_genid_ipv4(dev_net(dev)); 1469 rth->rt_flags = RTCF_MULTICAST; 1470 rth->rt_type = RTN_MULTICAST; 1471 rth->rt_is_input= 1; 1472 rth->rt_iif = 0; 1473 rth->rt_pmtu = 0; 1474 rth->rt_gateway = 0; 1475 rth->rt_uses_gateway = 0; 1476 INIT_LIST_HEAD(&rth->rt_uncached); 1477 if (our) { 1478 rth->dst.input= ip_local_deliver; 1479 rth->rt_flags |= RTCF_LOCAL; 1480 } 1481 1482 #ifdef CONFIG_IP_MROUTE 1483 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1484 rth->dst.input = ip_mr_input; 1485 #endif 1486 RT_CACHE_STAT_INC(in_slow_mc); 1487 1488 skb_dst_set(skb, &rth->dst); 1489 return 0; 1490 1491 e_nobufs: 1492 return -ENOBUFS; 1493 e_inval: 1494 return -EINVAL; 1495 e_err: 1496 return err; 1497 } 1498 1499 1500 static void ip_handle_martian_source(struct net_device *dev, 1501 struct in_device *in_dev, 1502 struct sk_buff *skb, 1503 __be32 daddr, 1504 __be32 saddr) 1505 { 1506 RT_CACHE_STAT_INC(in_martian_src); 1507 #ifdef CONFIG_IP_ROUTE_VERBOSE 1508 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1509 /* 1510 * RFC1812 recommendation, if source is martian, 1511 * the only hint is MAC header. 1512 */ 1513 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1514 &daddr, &saddr, dev->name); 1515 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1516 print_hex_dump(KERN_WARNING, "ll header: ", 1517 DUMP_PREFIX_OFFSET, 16, 1, 1518 skb_mac_header(skb), 1519 dev->hard_header_len, true); 1520 } 1521 } 1522 #endif 1523 } 1524 1525 /* called in rcu_read_lock() section */ 1526 static int __mkroute_input(struct sk_buff *skb, 1527 const struct fib_result *res, 1528 struct in_device *in_dev, 1529 __be32 daddr, __be32 saddr, u32 tos) 1530 { 1531 struct fib_nh_exception *fnhe; 1532 struct rtable *rth; 1533 int err; 1534 struct in_device *out_dev; 1535 unsigned int flags = 0; 1536 bool do_cache; 1537 u32 itag = 0; 1538 1539 /* get a working reference to the output device */ 1540 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1541 if (out_dev == NULL) { 1542 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1543 return -EINVAL; 1544 } 1545 1546 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1547 in_dev->dev, in_dev, &itag); 1548 if (err < 0) { 1549 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1550 saddr); 1551 1552 goto cleanup; 1553 } 1554 1555 do_cache = res->fi && !itag; 1556 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1557 (IN_DEV_SHARED_MEDIA(out_dev) || 1558 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) { 1559 flags |= RTCF_DOREDIRECT; 1560 do_cache = false; 1561 } 1562 1563 if (skb->protocol != htons(ETH_P_IP)) { 1564 /* Not IP (i.e. ARP). Do not create route, if it is 1565 * invalid for proxy arp. DNAT routes are always valid. 1566 * 1567 * Proxy arp feature have been extended to allow, ARP 1568 * replies back to the same interface, to support 1569 * Private VLAN switch technologies. See arp.c. 1570 */ 1571 if (out_dev == in_dev && 1572 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1573 err = -EINVAL; 1574 goto cleanup; 1575 } 1576 } 1577 1578 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1579 if (do_cache) { 1580 if (fnhe != NULL) 1581 rth = rcu_dereference(fnhe->fnhe_rth_input); 1582 else 1583 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1584 1585 if (rt_cache_valid(rth)) { 1586 skb_dst_set_noref(skb, &rth->dst); 1587 goto out; 1588 } 1589 } 1590 1591 rth = rt_dst_alloc(out_dev->dev, 1592 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1593 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1594 if (!rth) { 1595 err = -ENOBUFS; 1596 goto cleanup; 1597 } 1598 1599 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev)); 1600 rth->rt_flags = flags; 1601 rth->rt_type = res->type; 1602 rth->rt_is_input = 1; 1603 rth->rt_iif = 0; 1604 rth->rt_pmtu = 0; 1605 rth->rt_gateway = 0; 1606 rth->rt_uses_gateway = 0; 1607 INIT_LIST_HEAD(&rth->rt_uncached); 1608 RT_CACHE_STAT_INC(in_slow_tot); 1609 1610 rth->dst.input = ip_forward; 1611 rth->dst.output = ip_output; 1612 1613 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); 1614 skb_dst_set(skb, &rth->dst); 1615 out: 1616 err = 0; 1617 cleanup: 1618 return err; 1619 } 1620 1621 static int ip_mkroute_input(struct sk_buff *skb, 1622 struct fib_result *res, 1623 const struct flowi4 *fl4, 1624 struct in_device *in_dev, 1625 __be32 daddr, __be32 saddr, u32 tos) 1626 { 1627 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1628 if (res->fi && res->fi->fib_nhs > 1) 1629 fib_select_multipath(res); 1630 #endif 1631 1632 /* create a routing cache entry */ 1633 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1634 } 1635 1636 /* 1637 * NOTE. We drop all the packets that has local source 1638 * addresses, because every properly looped back packet 1639 * must have correct destination already attached by output routine. 1640 * 1641 * Such approach solves two big problems: 1642 * 1. Not simplex devices are handled properly. 1643 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1644 * called with rcu_read_lock() 1645 */ 1646 1647 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1648 u8 tos, struct net_device *dev) 1649 { 1650 struct fib_result res; 1651 struct in_device *in_dev = __in_dev_get_rcu(dev); 1652 struct flowi4 fl4; 1653 unsigned int flags = 0; 1654 u32 itag = 0; 1655 struct rtable *rth; 1656 int err = -EINVAL; 1657 struct net *net = dev_net(dev); 1658 bool do_cache; 1659 1660 /* IP on this device is disabled. */ 1661 1662 if (!in_dev) 1663 goto out; 1664 1665 /* Check for the most weird martians, which can be not detected 1666 by fib_lookup. 1667 */ 1668 1669 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1670 goto martian_source; 1671 1672 res.fi = NULL; 1673 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1674 goto brd_input; 1675 1676 /* Accept zero addresses only to limited broadcast; 1677 * I even do not know to fix it or not. Waiting for complains :-) 1678 */ 1679 if (ipv4_is_zeronet(saddr)) 1680 goto martian_source; 1681 1682 if (ipv4_is_zeronet(daddr)) 1683 goto martian_destination; 1684 1685 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1686 * and call it once if daddr or/and saddr are loopback addresses 1687 */ 1688 if (ipv4_is_loopback(daddr)) { 1689 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1690 goto martian_destination; 1691 } else if (ipv4_is_loopback(saddr)) { 1692 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1693 goto martian_source; 1694 } 1695 1696 /* 1697 * Now we are ready to route packet. 1698 */ 1699 fl4.flowi4_oif = 0; 1700 fl4.flowi4_iif = dev->ifindex; 1701 fl4.flowi4_mark = skb->mark; 1702 fl4.flowi4_tos = tos; 1703 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1704 fl4.daddr = daddr; 1705 fl4.saddr = saddr; 1706 err = fib_lookup(net, &fl4, &res); 1707 if (err != 0) { 1708 if (!IN_DEV_FORWARD(in_dev)) 1709 err = -EHOSTUNREACH; 1710 goto no_route; 1711 } 1712 1713 if (res.type == RTN_BROADCAST) 1714 goto brd_input; 1715 1716 if (res.type == RTN_LOCAL) { 1717 err = fib_validate_source(skb, saddr, daddr, tos, 1718 0, dev, in_dev, &itag); 1719 if (err < 0) 1720 goto martian_source_keep_err; 1721 goto local_input; 1722 } 1723 1724 if (!IN_DEV_FORWARD(in_dev)) { 1725 err = -EHOSTUNREACH; 1726 goto no_route; 1727 } 1728 if (res.type != RTN_UNICAST) 1729 goto martian_destination; 1730 1731 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1732 out: return err; 1733 1734 brd_input: 1735 if (skb->protocol != htons(ETH_P_IP)) 1736 goto e_inval; 1737 1738 if (!ipv4_is_zeronet(saddr)) { 1739 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1740 in_dev, &itag); 1741 if (err < 0) 1742 goto martian_source_keep_err; 1743 } 1744 flags |= RTCF_BROADCAST; 1745 res.type = RTN_BROADCAST; 1746 RT_CACHE_STAT_INC(in_brd); 1747 1748 local_input: 1749 do_cache = false; 1750 if (res.fi) { 1751 if (!itag) { 1752 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1753 if (rt_cache_valid(rth)) { 1754 skb_dst_set_noref(skb, &rth->dst); 1755 err = 0; 1756 goto out; 1757 } 1758 do_cache = true; 1759 } 1760 } 1761 1762 rth = rt_dst_alloc(net->loopback_dev, 1763 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1764 if (!rth) 1765 goto e_nobufs; 1766 1767 rth->dst.input= ip_local_deliver; 1768 rth->dst.output= ip_rt_bug; 1769 #ifdef CONFIG_IP_ROUTE_CLASSID 1770 rth->dst.tclassid = itag; 1771 #endif 1772 1773 rth->rt_genid = rt_genid_ipv4(net); 1774 rth->rt_flags = flags|RTCF_LOCAL; 1775 rth->rt_type = res.type; 1776 rth->rt_is_input = 1; 1777 rth->rt_iif = 0; 1778 rth->rt_pmtu = 0; 1779 rth->rt_gateway = 0; 1780 rth->rt_uses_gateway = 0; 1781 INIT_LIST_HEAD(&rth->rt_uncached); 1782 RT_CACHE_STAT_INC(in_slow_tot); 1783 if (res.type == RTN_UNREACHABLE) { 1784 rth->dst.input= ip_error; 1785 rth->dst.error= -err; 1786 rth->rt_flags &= ~RTCF_LOCAL; 1787 } 1788 if (do_cache) { 1789 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { 1790 rth->dst.flags |= DST_NOCACHE; 1791 rt_add_uncached_list(rth); 1792 } 1793 } 1794 skb_dst_set(skb, &rth->dst); 1795 err = 0; 1796 goto out; 1797 1798 no_route: 1799 RT_CACHE_STAT_INC(in_no_route); 1800 res.type = RTN_UNREACHABLE; 1801 res.fi = NULL; 1802 goto local_input; 1803 1804 /* 1805 * Do not cache martian addresses: they should be logged (RFC1812) 1806 */ 1807 martian_destination: 1808 RT_CACHE_STAT_INC(in_martian_dst); 1809 #ifdef CONFIG_IP_ROUTE_VERBOSE 1810 if (IN_DEV_LOG_MARTIANS(in_dev)) 1811 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1812 &daddr, &saddr, dev->name); 1813 #endif 1814 1815 e_inval: 1816 err = -EINVAL; 1817 goto out; 1818 1819 e_nobufs: 1820 err = -ENOBUFS; 1821 goto out; 1822 1823 martian_source: 1824 err = -EINVAL; 1825 martian_source_keep_err: 1826 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1827 goto out; 1828 } 1829 1830 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1831 u8 tos, struct net_device *dev) 1832 { 1833 int res; 1834 1835 rcu_read_lock(); 1836 1837 /* Multicast recognition logic is moved from route cache to here. 1838 The problem was that too many Ethernet cards have broken/missing 1839 hardware multicast filters :-( As result the host on multicasting 1840 network acquires a lot of useless route cache entries, sort of 1841 SDR messages from all the world. Now we try to get rid of them. 1842 Really, provided software IP multicast filter is organized 1843 reasonably (at least, hashed), it does not result in a slowdown 1844 comparing with route cache reject entries. 1845 Note, that multicast routers are not affected, because 1846 route cache entry is created eventually. 1847 */ 1848 if (ipv4_is_multicast(daddr)) { 1849 struct in_device *in_dev = __in_dev_get_rcu(dev); 1850 1851 if (in_dev) { 1852 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1853 ip_hdr(skb)->protocol); 1854 if (our 1855 #ifdef CONFIG_IP_MROUTE 1856 || 1857 (!ipv4_is_local_multicast(daddr) && 1858 IN_DEV_MFORWARD(in_dev)) 1859 #endif 1860 ) { 1861 int res = ip_route_input_mc(skb, daddr, saddr, 1862 tos, dev, our); 1863 rcu_read_unlock(); 1864 return res; 1865 } 1866 } 1867 rcu_read_unlock(); 1868 return -EINVAL; 1869 } 1870 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1871 rcu_read_unlock(); 1872 return res; 1873 } 1874 EXPORT_SYMBOL(ip_route_input_noref); 1875 1876 /* called with rcu_read_lock() */ 1877 static struct rtable *__mkroute_output(const struct fib_result *res, 1878 const struct flowi4 *fl4, int orig_oif, 1879 struct net_device *dev_out, 1880 unsigned int flags) 1881 { 1882 struct fib_info *fi = res->fi; 1883 struct fib_nh_exception *fnhe; 1884 struct in_device *in_dev; 1885 u16 type = res->type; 1886 struct rtable *rth; 1887 bool do_cache; 1888 1889 in_dev = __in_dev_get_rcu(dev_out); 1890 if (!in_dev) 1891 return ERR_PTR(-EINVAL); 1892 1893 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1894 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1895 return ERR_PTR(-EINVAL); 1896 1897 if (ipv4_is_lbcast(fl4->daddr)) 1898 type = RTN_BROADCAST; 1899 else if (ipv4_is_multicast(fl4->daddr)) 1900 type = RTN_MULTICAST; 1901 else if (ipv4_is_zeronet(fl4->daddr)) 1902 return ERR_PTR(-EINVAL); 1903 1904 if (dev_out->flags & IFF_LOOPBACK) 1905 flags |= RTCF_LOCAL; 1906 1907 do_cache = true; 1908 if (type == RTN_BROADCAST) { 1909 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1910 fi = NULL; 1911 } else if (type == RTN_MULTICAST) { 1912 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1913 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1914 fl4->flowi4_proto)) 1915 flags &= ~RTCF_LOCAL; 1916 else 1917 do_cache = false; 1918 /* If multicast route do not exist use 1919 * default one, but do not gateway in this case. 1920 * Yes, it is hack. 1921 */ 1922 if (fi && res->prefixlen < 4) 1923 fi = NULL; 1924 } 1925 1926 fnhe = NULL; 1927 do_cache &= fi != NULL; 1928 if (do_cache) { 1929 struct rtable __rcu **prth; 1930 struct fib_nh *nh = &FIB_RES_NH(*res); 1931 1932 fnhe = find_exception(nh, fl4->daddr); 1933 if (fnhe) 1934 prth = &fnhe->fnhe_rth_output; 1935 else { 1936 if (unlikely(fl4->flowi4_flags & 1937 FLOWI_FLAG_KNOWN_NH && 1938 !(nh->nh_gw && 1939 nh->nh_scope == RT_SCOPE_LINK))) { 1940 do_cache = false; 1941 goto add; 1942 } 1943 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 1944 } 1945 rth = rcu_dereference(*prth); 1946 if (rt_cache_valid(rth)) { 1947 dst_hold(&rth->dst); 1948 return rth; 1949 } 1950 } 1951 1952 add: 1953 rth = rt_dst_alloc(dev_out, 1954 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1955 IN_DEV_CONF_GET(in_dev, NOXFRM), 1956 do_cache); 1957 if (!rth) 1958 return ERR_PTR(-ENOBUFS); 1959 1960 rth->dst.output = ip_output; 1961 1962 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out)); 1963 rth->rt_flags = flags; 1964 rth->rt_type = type; 1965 rth->rt_is_input = 0; 1966 rth->rt_iif = orig_oif ? : 0; 1967 rth->rt_pmtu = 0; 1968 rth->rt_gateway = 0; 1969 rth->rt_uses_gateway = 0; 1970 INIT_LIST_HEAD(&rth->rt_uncached); 1971 1972 RT_CACHE_STAT_INC(out_slow_tot); 1973 1974 if (flags & RTCF_LOCAL) 1975 rth->dst.input = ip_local_deliver; 1976 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 1977 if (flags & RTCF_LOCAL && 1978 !(dev_out->flags & IFF_LOOPBACK)) { 1979 rth->dst.output = ip_mc_output; 1980 RT_CACHE_STAT_INC(out_slow_mc); 1981 } 1982 #ifdef CONFIG_IP_MROUTE 1983 if (type == RTN_MULTICAST) { 1984 if (IN_DEV_MFORWARD(in_dev) && 1985 !ipv4_is_local_multicast(fl4->daddr)) { 1986 rth->dst.input = ip_mr_input; 1987 rth->dst.output = ip_mc_output; 1988 } 1989 } 1990 #endif 1991 } 1992 1993 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 1994 1995 return rth; 1996 } 1997 1998 /* 1999 * Major route resolver routine. 2000 */ 2001 2002 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 2003 { 2004 struct net_device *dev_out = NULL; 2005 __u8 tos = RT_FL_TOS(fl4); 2006 unsigned int flags = 0; 2007 struct fib_result res; 2008 struct rtable *rth; 2009 int orig_oif; 2010 2011 res.tclassid = 0; 2012 res.fi = NULL; 2013 res.table = NULL; 2014 2015 orig_oif = fl4->flowi4_oif; 2016 2017 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2018 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2019 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2020 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2021 2022 rcu_read_lock(); 2023 if (fl4->saddr) { 2024 rth = ERR_PTR(-EINVAL); 2025 if (ipv4_is_multicast(fl4->saddr) || 2026 ipv4_is_lbcast(fl4->saddr) || 2027 ipv4_is_zeronet(fl4->saddr)) 2028 goto out; 2029 2030 /* I removed check for oif == dev_out->oif here. 2031 It was wrong for two reasons: 2032 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2033 is assigned to multiple interfaces. 2034 2. Moreover, we are allowed to send packets with saddr 2035 of another iface. --ANK 2036 */ 2037 2038 if (fl4->flowi4_oif == 0 && 2039 (ipv4_is_multicast(fl4->daddr) || 2040 ipv4_is_lbcast(fl4->daddr))) { 2041 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2042 dev_out = __ip_dev_find(net, fl4->saddr, false); 2043 if (dev_out == NULL) 2044 goto out; 2045 2046 /* Special hack: user can direct multicasts 2047 and limited broadcast via necessary interface 2048 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2049 This hack is not just for fun, it allows 2050 vic,vat and friends to work. 2051 They bind socket to loopback, set ttl to zero 2052 and expect that it will work. 2053 From the viewpoint of routing cache they are broken, 2054 because we are not allowed to build multicast path 2055 with loopback source addr (look, routing cache 2056 cannot know, that ttl is zero, so that packet 2057 will not leave this host and route is valid). 2058 Luckily, this hack is good workaround. 2059 */ 2060 2061 fl4->flowi4_oif = dev_out->ifindex; 2062 goto make_route; 2063 } 2064 2065 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2066 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2067 if (!__ip_dev_find(net, fl4->saddr, false)) 2068 goto out; 2069 } 2070 } 2071 2072 2073 if (fl4->flowi4_oif) { 2074 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2075 rth = ERR_PTR(-ENODEV); 2076 if (dev_out == NULL) 2077 goto out; 2078 2079 /* RACE: Check return value of inet_select_addr instead. */ 2080 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2081 rth = ERR_PTR(-ENETUNREACH); 2082 goto out; 2083 } 2084 if (ipv4_is_local_multicast(fl4->daddr) || 2085 ipv4_is_lbcast(fl4->daddr)) { 2086 if (!fl4->saddr) 2087 fl4->saddr = inet_select_addr(dev_out, 0, 2088 RT_SCOPE_LINK); 2089 goto make_route; 2090 } 2091 if (!fl4->saddr) { 2092 if (ipv4_is_multicast(fl4->daddr)) 2093 fl4->saddr = inet_select_addr(dev_out, 0, 2094 fl4->flowi4_scope); 2095 else if (!fl4->daddr) 2096 fl4->saddr = inet_select_addr(dev_out, 0, 2097 RT_SCOPE_HOST); 2098 } 2099 } 2100 2101 if (!fl4->daddr) { 2102 fl4->daddr = fl4->saddr; 2103 if (!fl4->daddr) 2104 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2105 dev_out = net->loopback_dev; 2106 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2107 res.type = RTN_LOCAL; 2108 flags |= RTCF_LOCAL; 2109 goto make_route; 2110 } 2111 2112 if (fib_lookup(net, fl4, &res)) { 2113 res.fi = NULL; 2114 res.table = NULL; 2115 if (fl4->flowi4_oif) { 2116 /* Apparently, routing tables are wrong. Assume, 2117 that the destination is on link. 2118 2119 WHY? DW. 2120 Because we are allowed to send to iface 2121 even if it has NO routes and NO assigned 2122 addresses. When oif is specified, routing 2123 tables are looked up with only one purpose: 2124 to catch if destination is gatewayed, rather than 2125 direct. Moreover, if MSG_DONTROUTE is set, 2126 we send packet, ignoring both routing tables 2127 and ifaddr state. --ANK 2128 2129 2130 We could make it even if oif is unknown, 2131 likely IPv6, but we do not. 2132 */ 2133 2134 if (fl4->saddr == 0) 2135 fl4->saddr = inet_select_addr(dev_out, 0, 2136 RT_SCOPE_LINK); 2137 res.type = RTN_UNICAST; 2138 goto make_route; 2139 } 2140 rth = ERR_PTR(-ENETUNREACH); 2141 goto out; 2142 } 2143 2144 if (res.type == RTN_LOCAL) { 2145 if (!fl4->saddr) { 2146 if (res.fi->fib_prefsrc) 2147 fl4->saddr = res.fi->fib_prefsrc; 2148 else 2149 fl4->saddr = fl4->daddr; 2150 } 2151 dev_out = net->loopback_dev; 2152 fl4->flowi4_oif = dev_out->ifindex; 2153 flags |= RTCF_LOCAL; 2154 goto make_route; 2155 } 2156 2157 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2158 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2159 fib_select_multipath(&res); 2160 else 2161 #endif 2162 if (!res.prefixlen && 2163 res.table->tb_num_default > 1 && 2164 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2165 fib_select_default(&res); 2166 2167 if (!fl4->saddr) 2168 fl4->saddr = FIB_RES_PREFSRC(net, res); 2169 2170 dev_out = FIB_RES_DEV(res); 2171 fl4->flowi4_oif = dev_out->ifindex; 2172 2173 2174 make_route: 2175 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2176 2177 out: 2178 rcu_read_unlock(); 2179 return rth; 2180 } 2181 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2182 2183 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2184 { 2185 return NULL; 2186 } 2187 2188 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2189 { 2190 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2191 2192 return mtu ? : dst->dev->mtu; 2193 } 2194 2195 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2196 struct sk_buff *skb, u32 mtu) 2197 { 2198 } 2199 2200 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2201 struct sk_buff *skb) 2202 { 2203 } 2204 2205 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2206 unsigned long old) 2207 { 2208 return NULL; 2209 } 2210 2211 static struct dst_ops ipv4_dst_blackhole_ops = { 2212 .family = AF_INET, 2213 .protocol = cpu_to_be16(ETH_P_IP), 2214 .check = ipv4_blackhole_dst_check, 2215 .mtu = ipv4_blackhole_mtu, 2216 .default_advmss = ipv4_default_advmss, 2217 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2218 .redirect = ipv4_rt_blackhole_redirect, 2219 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2220 .neigh_lookup = ipv4_neigh_lookup, 2221 }; 2222 2223 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2224 { 2225 struct rtable *ort = (struct rtable *) dst_orig; 2226 struct rtable *rt; 2227 2228 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2229 if (rt) { 2230 struct dst_entry *new = &rt->dst; 2231 2232 new->__use = 1; 2233 new->input = dst_discard; 2234 new->output = dst_discard_sk; 2235 2236 new->dev = ort->dst.dev; 2237 if (new->dev) 2238 dev_hold(new->dev); 2239 2240 rt->rt_is_input = ort->rt_is_input; 2241 rt->rt_iif = ort->rt_iif; 2242 rt->rt_pmtu = ort->rt_pmtu; 2243 2244 rt->rt_genid = rt_genid_ipv4(net); 2245 rt->rt_flags = ort->rt_flags; 2246 rt->rt_type = ort->rt_type; 2247 rt->rt_gateway = ort->rt_gateway; 2248 rt->rt_uses_gateway = ort->rt_uses_gateway; 2249 2250 INIT_LIST_HEAD(&rt->rt_uncached); 2251 2252 dst_free(new); 2253 } 2254 2255 dst_release(dst_orig); 2256 2257 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2258 } 2259 2260 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2261 struct sock *sk) 2262 { 2263 struct rtable *rt = __ip_route_output_key(net, flp4); 2264 2265 if (IS_ERR(rt)) 2266 return rt; 2267 2268 if (flp4->flowi4_proto) 2269 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2270 flowi4_to_flowi(flp4), 2271 sk, 0); 2272 2273 return rt; 2274 } 2275 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2276 2277 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2278 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2279 u32 seq, int event, int nowait, unsigned int flags) 2280 { 2281 struct rtable *rt = skb_rtable(skb); 2282 struct rtmsg *r; 2283 struct nlmsghdr *nlh; 2284 unsigned long expires = 0; 2285 u32 error; 2286 u32 metrics[RTAX_MAX]; 2287 2288 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2289 if (nlh == NULL) 2290 return -EMSGSIZE; 2291 2292 r = nlmsg_data(nlh); 2293 r->rtm_family = AF_INET; 2294 r->rtm_dst_len = 32; 2295 r->rtm_src_len = 0; 2296 r->rtm_tos = fl4->flowi4_tos; 2297 r->rtm_table = RT_TABLE_MAIN; 2298 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) 2299 goto nla_put_failure; 2300 r->rtm_type = rt->rt_type; 2301 r->rtm_scope = RT_SCOPE_UNIVERSE; 2302 r->rtm_protocol = RTPROT_UNSPEC; 2303 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2304 if (rt->rt_flags & RTCF_NOTIFY) 2305 r->rtm_flags |= RTM_F_NOTIFY; 2306 2307 if (nla_put_be32(skb, RTA_DST, dst)) 2308 goto nla_put_failure; 2309 if (src) { 2310 r->rtm_src_len = 32; 2311 if (nla_put_be32(skb, RTA_SRC, src)) 2312 goto nla_put_failure; 2313 } 2314 if (rt->dst.dev && 2315 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2316 goto nla_put_failure; 2317 #ifdef CONFIG_IP_ROUTE_CLASSID 2318 if (rt->dst.tclassid && 2319 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2320 goto nla_put_failure; 2321 #endif 2322 if (!rt_is_input_route(rt) && 2323 fl4->saddr != src) { 2324 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr)) 2325 goto nla_put_failure; 2326 } 2327 if (rt->rt_uses_gateway && 2328 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway)) 2329 goto nla_put_failure; 2330 2331 expires = rt->dst.expires; 2332 if (expires) { 2333 unsigned long now = jiffies; 2334 2335 if (time_before(now, expires)) 2336 expires -= now; 2337 else 2338 expires = 0; 2339 } 2340 2341 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2342 if (rt->rt_pmtu && expires) 2343 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2344 if (rtnetlink_put_metrics(skb, metrics) < 0) 2345 goto nla_put_failure; 2346 2347 if (fl4->flowi4_mark && 2348 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2349 goto nla_put_failure; 2350 2351 error = rt->dst.error; 2352 2353 if (rt_is_input_route(rt)) { 2354 #ifdef CONFIG_IP_MROUTE 2355 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2356 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2357 int err = ipmr_get_route(net, skb, 2358 fl4->saddr, fl4->daddr, 2359 r, nowait); 2360 if (err <= 0) { 2361 if (!nowait) { 2362 if (err == 0) 2363 return 0; 2364 goto nla_put_failure; 2365 } else { 2366 if (err == -EMSGSIZE) 2367 goto nla_put_failure; 2368 error = err; 2369 } 2370 } 2371 } else 2372 #endif 2373 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) 2374 goto nla_put_failure; 2375 } 2376 2377 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2378 goto nla_put_failure; 2379 2380 return nlmsg_end(skb, nlh); 2381 2382 nla_put_failure: 2383 nlmsg_cancel(skb, nlh); 2384 return -EMSGSIZE; 2385 } 2386 2387 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 2388 { 2389 struct net *net = sock_net(in_skb->sk); 2390 struct rtmsg *rtm; 2391 struct nlattr *tb[RTA_MAX+1]; 2392 struct rtable *rt = NULL; 2393 struct flowi4 fl4; 2394 __be32 dst = 0; 2395 __be32 src = 0; 2396 u32 iif; 2397 int err; 2398 int mark; 2399 struct sk_buff *skb; 2400 2401 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2402 if (err < 0) 2403 goto errout; 2404 2405 rtm = nlmsg_data(nlh); 2406 2407 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2408 if (skb == NULL) { 2409 err = -ENOBUFS; 2410 goto errout; 2411 } 2412 2413 /* Reserve room for dummy headers, this skb can pass 2414 through good chunk of routing engine. 2415 */ 2416 skb_reset_mac_header(skb); 2417 skb_reset_network_header(skb); 2418 2419 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2420 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2421 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2422 2423 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2424 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2425 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2426 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2427 2428 memset(&fl4, 0, sizeof(fl4)); 2429 fl4.daddr = dst; 2430 fl4.saddr = src; 2431 fl4.flowi4_tos = rtm->rtm_tos; 2432 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2433 fl4.flowi4_mark = mark; 2434 2435 if (iif) { 2436 struct net_device *dev; 2437 2438 dev = __dev_get_by_index(net, iif); 2439 if (dev == NULL) { 2440 err = -ENODEV; 2441 goto errout_free; 2442 } 2443 2444 skb->protocol = htons(ETH_P_IP); 2445 skb->dev = dev; 2446 skb->mark = mark; 2447 local_bh_disable(); 2448 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2449 local_bh_enable(); 2450 2451 rt = skb_rtable(skb); 2452 if (err == 0 && rt->dst.error) 2453 err = -rt->dst.error; 2454 } else { 2455 rt = ip_route_output_key(net, &fl4); 2456 2457 err = 0; 2458 if (IS_ERR(rt)) 2459 err = PTR_ERR(rt); 2460 } 2461 2462 if (err) 2463 goto errout_free; 2464 2465 skb_dst_set(skb, &rt->dst); 2466 if (rtm->rtm_flags & RTM_F_NOTIFY) 2467 rt->rt_flags |= RTCF_NOTIFY; 2468 2469 err = rt_fill_info(net, dst, src, &fl4, skb, 2470 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2471 RTM_NEWROUTE, 0, 0); 2472 if (err <= 0) 2473 goto errout_free; 2474 2475 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2476 errout: 2477 return err; 2478 2479 errout_free: 2480 kfree_skb(skb); 2481 goto errout; 2482 } 2483 2484 void ip_rt_multicast_event(struct in_device *in_dev) 2485 { 2486 rt_cache_flush(dev_net(in_dev->dev)); 2487 } 2488 2489 #ifdef CONFIG_SYSCTL 2490 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2491 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2492 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2493 static int ip_rt_gc_elasticity __read_mostly = 8; 2494 2495 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2496 void __user *buffer, 2497 size_t *lenp, loff_t *ppos) 2498 { 2499 struct net *net = (struct net *)__ctl->extra1; 2500 2501 if (write) { 2502 rt_cache_flush(net); 2503 fnhe_genid_bump(net); 2504 return 0; 2505 } 2506 2507 return -EINVAL; 2508 } 2509 2510 static struct ctl_table ipv4_route_table[] = { 2511 { 2512 .procname = "gc_thresh", 2513 .data = &ipv4_dst_ops.gc_thresh, 2514 .maxlen = sizeof(int), 2515 .mode = 0644, 2516 .proc_handler = proc_dointvec, 2517 }, 2518 { 2519 .procname = "max_size", 2520 .data = &ip_rt_max_size, 2521 .maxlen = sizeof(int), 2522 .mode = 0644, 2523 .proc_handler = proc_dointvec, 2524 }, 2525 { 2526 /* Deprecated. Use gc_min_interval_ms */ 2527 2528 .procname = "gc_min_interval", 2529 .data = &ip_rt_gc_min_interval, 2530 .maxlen = sizeof(int), 2531 .mode = 0644, 2532 .proc_handler = proc_dointvec_jiffies, 2533 }, 2534 { 2535 .procname = "gc_min_interval_ms", 2536 .data = &ip_rt_gc_min_interval, 2537 .maxlen = sizeof(int), 2538 .mode = 0644, 2539 .proc_handler = proc_dointvec_ms_jiffies, 2540 }, 2541 { 2542 .procname = "gc_timeout", 2543 .data = &ip_rt_gc_timeout, 2544 .maxlen = sizeof(int), 2545 .mode = 0644, 2546 .proc_handler = proc_dointvec_jiffies, 2547 }, 2548 { 2549 .procname = "gc_interval", 2550 .data = &ip_rt_gc_interval, 2551 .maxlen = sizeof(int), 2552 .mode = 0644, 2553 .proc_handler = proc_dointvec_jiffies, 2554 }, 2555 { 2556 .procname = "redirect_load", 2557 .data = &ip_rt_redirect_load, 2558 .maxlen = sizeof(int), 2559 .mode = 0644, 2560 .proc_handler = proc_dointvec, 2561 }, 2562 { 2563 .procname = "redirect_number", 2564 .data = &ip_rt_redirect_number, 2565 .maxlen = sizeof(int), 2566 .mode = 0644, 2567 .proc_handler = proc_dointvec, 2568 }, 2569 { 2570 .procname = "redirect_silence", 2571 .data = &ip_rt_redirect_silence, 2572 .maxlen = sizeof(int), 2573 .mode = 0644, 2574 .proc_handler = proc_dointvec, 2575 }, 2576 { 2577 .procname = "error_cost", 2578 .data = &ip_rt_error_cost, 2579 .maxlen = sizeof(int), 2580 .mode = 0644, 2581 .proc_handler = proc_dointvec, 2582 }, 2583 { 2584 .procname = "error_burst", 2585 .data = &ip_rt_error_burst, 2586 .maxlen = sizeof(int), 2587 .mode = 0644, 2588 .proc_handler = proc_dointvec, 2589 }, 2590 { 2591 .procname = "gc_elasticity", 2592 .data = &ip_rt_gc_elasticity, 2593 .maxlen = sizeof(int), 2594 .mode = 0644, 2595 .proc_handler = proc_dointvec, 2596 }, 2597 { 2598 .procname = "mtu_expires", 2599 .data = &ip_rt_mtu_expires, 2600 .maxlen = sizeof(int), 2601 .mode = 0644, 2602 .proc_handler = proc_dointvec_jiffies, 2603 }, 2604 { 2605 .procname = "min_pmtu", 2606 .data = &ip_rt_min_pmtu, 2607 .maxlen = sizeof(int), 2608 .mode = 0644, 2609 .proc_handler = proc_dointvec, 2610 }, 2611 { 2612 .procname = "min_adv_mss", 2613 .data = &ip_rt_min_advmss, 2614 .maxlen = sizeof(int), 2615 .mode = 0644, 2616 .proc_handler = proc_dointvec, 2617 }, 2618 { } 2619 }; 2620 2621 static struct ctl_table ipv4_route_flush_table[] = { 2622 { 2623 .procname = "flush", 2624 .maxlen = sizeof(int), 2625 .mode = 0200, 2626 .proc_handler = ipv4_sysctl_rtcache_flush, 2627 }, 2628 { }, 2629 }; 2630 2631 static __net_init int sysctl_route_net_init(struct net *net) 2632 { 2633 struct ctl_table *tbl; 2634 2635 tbl = ipv4_route_flush_table; 2636 if (!net_eq(net, &init_net)) { 2637 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2638 if (tbl == NULL) 2639 goto err_dup; 2640 2641 /* Don't export sysctls to unprivileged users */ 2642 if (net->user_ns != &init_user_ns) 2643 tbl[0].procname = NULL; 2644 } 2645 tbl[0].extra1 = net; 2646 2647 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2648 if (net->ipv4.route_hdr == NULL) 2649 goto err_reg; 2650 return 0; 2651 2652 err_reg: 2653 if (tbl != ipv4_route_flush_table) 2654 kfree(tbl); 2655 err_dup: 2656 return -ENOMEM; 2657 } 2658 2659 static __net_exit void sysctl_route_net_exit(struct net *net) 2660 { 2661 struct ctl_table *tbl; 2662 2663 tbl = net->ipv4.route_hdr->ctl_table_arg; 2664 unregister_net_sysctl_table(net->ipv4.route_hdr); 2665 BUG_ON(tbl == ipv4_route_flush_table); 2666 kfree(tbl); 2667 } 2668 2669 static __net_initdata struct pernet_operations sysctl_route_ops = { 2670 .init = sysctl_route_net_init, 2671 .exit = sysctl_route_net_exit, 2672 }; 2673 #endif 2674 2675 static __net_init int rt_genid_init(struct net *net) 2676 { 2677 atomic_set(&net->ipv4.rt_genid, 0); 2678 atomic_set(&net->fnhe_genid, 0); 2679 get_random_bytes(&net->ipv4.dev_addr_genid, 2680 sizeof(net->ipv4.dev_addr_genid)); 2681 return 0; 2682 } 2683 2684 static __net_initdata struct pernet_operations rt_genid_ops = { 2685 .init = rt_genid_init, 2686 }; 2687 2688 static int __net_init ipv4_inetpeer_init(struct net *net) 2689 { 2690 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2691 2692 if (!bp) 2693 return -ENOMEM; 2694 inet_peer_base_init(bp); 2695 net->ipv4.peers = bp; 2696 return 0; 2697 } 2698 2699 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2700 { 2701 struct inet_peer_base *bp = net->ipv4.peers; 2702 2703 net->ipv4.peers = NULL; 2704 inetpeer_invalidate_tree(bp); 2705 kfree(bp); 2706 } 2707 2708 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2709 .init = ipv4_inetpeer_init, 2710 .exit = ipv4_inetpeer_exit, 2711 }; 2712 2713 #ifdef CONFIG_IP_ROUTE_CLASSID 2714 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2715 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2716 2717 int __init ip_rt_init(void) 2718 { 2719 int rc = 0; 2720 2721 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); 2722 if (!ip_idents) 2723 panic("IP: failed to allocate ip_idents\n"); 2724 2725 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 2726 2727 #ifdef CONFIG_IP_ROUTE_CLASSID 2728 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2729 if (!ip_rt_acct) 2730 panic("IP: failed to allocate ip_rt_acct\n"); 2731 #endif 2732 2733 ipv4_dst_ops.kmem_cachep = 2734 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2735 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2736 2737 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2738 2739 if (dst_entries_init(&ipv4_dst_ops) < 0) 2740 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2741 2742 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2743 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2744 2745 ipv4_dst_ops.gc_thresh = ~0; 2746 ip_rt_max_size = INT_MAX; 2747 2748 devinet_init(); 2749 ip_fib_init(); 2750 2751 if (ip_rt_proc_init()) 2752 pr_err("Unable to create route proc files\n"); 2753 #ifdef CONFIG_XFRM 2754 xfrm_init(); 2755 xfrm4_init(); 2756 #endif 2757 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2758 2759 #ifdef CONFIG_SYSCTL 2760 register_pernet_subsys(&sysctl_route_ops); 2761 #endif 2762 register_pernet_subsys(&rt_genid_ops); 2763 register_pernet_subsys(&ipv4_inetpeer_ops); 2764 return rc; 2765 } 2766 2767 #ifdef CONFIG_SYSCTL 2768 /* 2769 * We really need to sanitize the damn ipv4 init order, then all 2770 * this nonsense will go away. 2771 */ 2772 void __init ip_static_sysctl_init(void) 2773 { 2774 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2775 } 2776 #endif 2777