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 <net/dst.h> 93 #include <net/net_namespace.h> 94 #include <net/protocol.h> 95 #include <net/ip.h> 96 #include <net/route.h> 97 #include <net/inetpeer.h> 98 #include <net/sock.h> 99 #include <net/ip_fib.h> 100 #include <net/arp.h> 101 #include <net/tcp.h> 102 #include <net/icmp.h> 103 #include <net/xfrm.h> 104 #include <net/netevent.h> 105 #include <net/rtnetlink.h> 106 #ifdef CONFIG_SYSCTL 107 #include <linux/sysctl.h> 108 #include <linux/kmemleak.h> 109 #endif 110 #include <net/secure_seq.h> 111 112 #define RT_FL_TOS(oldflp4) \ 113 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 114 115 #define IP_MAX_MTU 0xFFF0 116 117 #define RT_GC_TIMEOUT (300*HZ) 118 119 static int ip_rt_max_size; 120 static int ip_rt_redirect_number __read_mostly = 9; 121 static int ip_rt_redirect_load __read_mostly = HZ / 50; 122 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 123 static int ip_rt_error_cost __read_mostly = HZ; 124 static int ip_rt_error_burst __read_mostly = 5 * HZ; 125 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 126 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 127 static int ip_rt_min_advmss __read_mostly = 256; 128 129 /* 130 * Interface to generic destination cache. 131 */ 132 133 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 134 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 135 static unsigned int ipv4_mtu(const struct dst_entry *dst); 136 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 137 static void ipv4_link_failure(struct sk_buff *skb); 138 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 139 struct sk_buff *skb, u32 mtu); 140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 141 struct sk_buff *skb); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 144 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 145 int how) 146 { 147 } 148 149 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 150 { 151 WARN_ON(1); 152 return NULL; 153 } 154 155 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 156 struct sk_buff *skb, 157 const void *daddr); 158 159 static struct dst_ops ipv4_dst_ops = { 160 .family = AF_INET, 161 .protocol = cpu_to_be16(ETH_P_IP), 162 .check = ipv4_dst_check, 163 .default_advmss = ipv4_default_advmss, 164 .mtu = ipv4_mtu, 165 .cow_metrics = ipv4_cow_metrics, 166 .destroy = ipv4_dst_destroy, 167 .ifdown = ipv4_dst_ifdown, 168 .negative_advice = ipv4_negative_advice, 169 .link_failure = ipv4_link_failure, 170 .update_pmtu = ip_rt_update_pmtu, 171 .redirect = ip_do_redirect, 172 .local_out = __ip_local_out, 173 .neigh_lookup = ipv4_neigh_lookup, 174 }; 175 176 #define ECN_OR_COST(class) TC_PRIO_##class 177 178 const __u8 ip_tos2prio[16] = { 179 TC_PRIO_BESTEFFORT, 180 ECN_OR_COST(BESTEFFORT), 181 TC_PRIO_BESTEFFORT, 182 ECN_OR_COST(BESTEFFORT), 183 TC_PRIO_BULK, 184 ECN_OR_COST(BULK), 185 TC_PRIO_BULK, 186 ECN_OR_COST(BULK), 187 TC_PRIO_INTERACTIVE, 188 ECN_OR_COST(INTERACTIVE), 189 TC_PRIO_INTERACTIVE, 190 ECN_OR_COST(INTERACTIVE), 191 TC_PRIO_INTERACTIVE_BULK, 192 ECN_OR_COST(INTERACTIVE_BULK), 193 TC_PRIO_INTERACTIVE_BULK, 194 ECN_OR_COST(INTERACTIVE_BULK) 195 }; 196 EXPORT_SYMBOL(ip_tos2prio); 197 198 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 199 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) 200 201 #ifdef CONFIG_PROC_FS 202 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 203 { 204 if (*pos) 205 return NULL; 206 return SEQ_START_TOKEN; 207 } 208 209 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 210 { 211 ++*pos; 212 return NULL; 213 } 214 215 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 216 { 217 } 218 219 static int rt_cache_seq_show(struct seq_file *seq, void *v) 220 { 221 if (v == SEQ_START_TOKEN) 222 seq_printf(seq, "%-127s\n", 223 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 224 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 225 "HHUptod\tSpecDst"); 226 return 0; 227 } 228 229 static const struct seq_operations rt_cache_seq_ops = { 230 .start = rt_cache_seq_start, 231 .next = rt_cache_seq_next, 232 .stop = rt_cache_seq_stop, 233 .show = rt_cache_seq_show, 234 }; 235 236 static int rt_cache_seq_open(struct inode *inode, struct file *file) 237 { 238 return seq_open(file, &rt_cache_seq_ops); 239 } 240 241 static const struct file_operations rt_cache_seq_fops = { 242 .owner = THIS_MODULE, 243 .open = rt_cache_seq_open, 244 .read = seq_read, 245 .llseek = seq_lseek, 246 .release = seq_release, 247 }; 248 249 250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 251 { 252 int cpu; 253 254 if (*pos == 0) 255 return SEQ_START_TOKEN; 256 257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 258 if (!cpu_possible(cpu)) 259 continue; 260 *pos = cpu+1; 261 return &per_cpu(rt_cache_stat, cpu); 262 } 263 return NULL; 264 } 265 266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 267 { 268 int cpu; 269 270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 271 if (!cpu_possible(cpu)) 272 continue; 273 *pos = cpu+1; 274 return &per_cpu(rt_cache_stat, cpu); 275 } 276 return NULL; 277 278 } 279 280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 281 { 282 283 } 284 285 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 286 { 287 struct rt_cache_stat *st = v; 288 289 if (v == SEQ_START_TOKEN) { 290 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"); 291 return 0; 292 } 293 294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 296 dst_entries_get_slow(&ipv4_dst_ops), 297 st->in_hit, 298 st->in_slow_tot, 299 st->in_slow_mc, 300 st->in_no_route, 301 st->in_brd, 302 st->in_martian_dst, 303 st->in_martian_src, 304 305 st->out_hit, 306 st->out_slow_tot, 307 st->out_slow_mc, 308 309 st->gc_total, 310 st->gc_ignored, 311 st->gc_goal_miss, 312 st->gc_dst_overflow, 313 st->in_hlist_search, 314 st->out_hlist_search 315 ); 316 return 0; 317 } 318 319 static const struct seq_operations rt_cpu_seq_ops = { 320 .start = rt_cpu_seq_start, 321 .next = rt_cpu_seq_next, 322 .stop = rt_cpu_seq_stop, 323 .show = rt_cpu_seq_show, 324 }; 325 326 327 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 328 { 329 return seq_open(file, &rt_cpu_seq_ops); 330 } 331 332 static const struct file_operations rt_cpu_seq_fops = { 333 .owner = THIS_MODULE, 334 .open = rt_cpu_seq_open, 335 .read = seq_read, 336 .llseek = seq_lseek, 337 .release = seq_release, 338 }; 339 340 #ifdef CONFIG_IP_ROUTE_CLASSID 341 static int rt_acct_proc_show(struct seq_file *m, void *v) 342 { 343 struct ip_rt_acct *dst, *src; 344 unsigned int i, j; 345 346 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 347 if (!dst) 348 return -ENOMEM; 349 350 for_each_possible_cpu(i) { 351 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 352 for (j = 0; j < 256; j++) { 353 dst[j].o_bytes += src[j].o_bytes; 354 dst[j].o_packets += src[j].o_packets; 355 dst[j].i_bytes += src[j].i_bytes; 356 dst[j].i_packets += src[j].i_packets; 357 } 358 } 359 360 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 361 kfree(dst); 362 return 0; 363 } 364 365 static int rt_acct_proc_open(struct inode *inode, struct file *file) 366 { 367 return single_open(file, rt_acct_proc_show, NULL); 368 } 369 370 static const struct file_operations rt_acct_proc_fops = { 371 .owner = THIS_MODULE, 372 .open = rt_acct_proc_open, 373 .read = seq_read, 374 .llseek = seq_lseek, 375 .release = single_release, 376 }; 377 #endif 378 379 static int __net_init ip_rt_do_proc_init(struct net *net) 380 { 381 struct proc_dir_entry *pde; 382 383 pde = proc_create("rt_cache", S_IRUGO, net->proc_net, 384 &rt_cache_seq_fops); 385 if (!pde) 386 goto err1; 387 388 pde = proc_create("rt_cache", S_IRUGO, 389 net->proc_net_stat, &rt_cpu_seq_fops); 390 if (!pde) 391 goto err2; 392 393 #ifdef CONFIG_IP_ROUTE_CLASSID 394 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 395 if (!pde) 396 goto err3; 397 #endif 398 return 0; 399 400 #ifdef CONFIG_IP_ROUTE_CLASSID 401 err3: 402 remove_proc_entry("rt_cache", net->proc_net_stat); 403 #endif 404 err2: 405 remove_proc_entry("rt_cache", net->proc_net); 406 err1: 407 return -ENOMEM; 408 } 409 410 static void __net_exit ip_rt_do_proc_exit(struct net *net) 411 { 412 remove_proc_entry("rt_cache", net->proc_net_stat); 413 remove_proc_entry("rt_cache", net->proc_net); 414 #ifdef CONFIG_IP_ROUTE_CLASSID 415 remove_proc_entry("rt_acct", net->proc_net); 416 #endif 417 } 418 419 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 420 .init = ip_rt_do_proc_init, 421 .exit = ip_rt_do_proc_exit, 422 }; 423 424 static int __init ip_rt_proc_init(void) 425 { 426 return register_pernet_subsys(&ip_rt_proc_ops); 427 } 428 429 #else 430 static inline int ip_rt_proc_init(void) 431 { 432 return 0; 433 } 434 #endif /* CONFIG_PROC_FS */ 435 436 static inline bool rt_is_expired(const struct rtable *rth) 437 { 438 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); 439 } 440 441 void rt_cache_flush(struct net *net) 442 { 443 rt_genid_bump(net); 444 } 445 446 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 447 struct sk_buff *skb, 448 const void *daddr) 449 { 450 struct net_device *dev = dst->dev; 451 const __be32 *pkey = daddr; 452 const struct rtable *rt; 453 struct neighbour *n; 454 455 rt = (const struct rtable *) dst; 456 if (rt->rt_gateway) 457 pkey = (const __be32 *) &rt->rt_gateway; 458 else if (skb) 459 pkey = &ip_hdr(skb)->daddr; 460 461 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 462 if (n) 463 return n; 464 return neigh_create(&arp_tbl, pkey, dev); 465 } 466 467 /* 468 * Peer allocation may fail only in serious out-of-memory conditions. However 469 * we still can generate some output. 470 * Random ID selection looks a bit dangerous because we have no chances to 471 * select ID being unique in a reasonable period of time. 472 * But broken packet identifier may be better than no packet at all. 473 */ 474 static void ip_select_fb_ident(struct iphdr *iph) 475 { 476 static DEFINE_SPINLOCK(ip_fb_id_lock); 477 static u32 ip_fallback_id; 478 u32 salt; 479 480 spin_lock_bh(&ip_fb_id_lock); 481 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); 482 iph->id = htons(salt & 0xFFFF); 483 ip_fallback_id = salt; 484 spin_unlock_bh(&ip_fb_id_lock); 485 } 486 487 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) 488 { 489 struct net *net = dev_net(dst->dev); 490 struct inet_peer *peer; 491 492 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1); 493 if (peer) { 494 iph->id = htons(inet_getid(peer, more)); 495 inet_putpeer(peer); 496 return; 497 } 498 499 ip_select_fb_ident(iph); 500 } 501 EXPORT_SYMBOL(__ip_select_ident); 502 503 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk, 504 const struct iphdr *iph, 505 int oif, u8 tos, 506 u8 prot, u32 mark, int flow_flags) 507 { 508 if (sk) { 509 const struct inet_sock *inet = inet_sk(sk); 510 511 oif = sk->sk_bound_dev_if; 512 mark = sk->sk_mark; 513 tos = RT_CONN_FLAGS(sk); 514 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 515 } 516 flowi4_init_output(fl4, oif, mark, tos, 517 RT_SCOPE_UNIVERSE, prot, 518 flow_flags, 519 iph->daddr, iph->saddr, 0, 0); 520 } 521 522 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 523 const struct sock *sk) 524 { 525 const struct iphdr *iph = ip_hdr(skb); 526 int oif = skb->dev->ifindex; 527 u8 tos = RT_TOS(iph->tos); 528 u8 prot = iph->protocol; 529 u32 mark = skb->mark; 530 531 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0); 532 } 533 534 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 535 { 536 const struct inet_sock *inet = inet_sk(sk); 537 const struct ip_options_rcu *inet_opt; 538 __be32 daddr = inet->inet_daddr; 539 540 rcu_read_lock(); 541 inet_opt = rcu_dereference(inet->inet_opt); 542 if (inet_opt && inet_opt->opt.srr) 543 daddr = inet_opt->opt.faddr; 544 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 545 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 546 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 547 inet_sk_flowi_flags(sk), 548 daddr, inet->inet_saddr, 0, 0); 549 rcu_read_unlock(); 550 } 551 552 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 553 const struct sk_buff *skb) 554 { 555 if (skb) 556 build_skb_flow_key(fl4, skb, sk); 557 else 558 build_sk_flow_key(fl4, sk); 559 } 560 561 static inline void rt_free(struct rtable *rt) 562 { 563 call_rcu(&rt->dst.rcu_head, dst_rcu_free); 564 } 565 566 static DEFINE_SPINLOCK(fnhe_lock); 567 568 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 569 { 570 struct fib_nh_exception *fnhe, *oldest; 571 struct rtable *orig; 572 573 oldest = rcu_dereference(hash->chain); 574 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 575 fnhe = rcu_dereference(fnhe->fnhe_next)) { 576 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 577 oldest = fnhe; 578 } 579 orig = rcu_dereference(oldest->fnhe_rth); 580 if (orig) { 581 RCU_INIT_POINTER(oldest->fnhe_rth, NULL); 582 rt_free(orig); 583 } 584 return oldest; 585 } 586 587 static inline u32 fnhe_hashfun(__be32 daddr) 588 { 589 u32 hval; 590 591 hval = (__force u32) daddr; 592 hval ^= (hval >> 11) ^ (hval >> 22); 593 594 return hval & (FNHE_HASH_SIZE - 1); 595 } 596 597 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 598 u32 pmtu, unsigned long expires) 599 { 600 struct fnhe_hash_bucket *hash; 601 struct fib_nh_exception *fnhe; 602 int depth; 603 u32 hval = fnhe_hashfun(daddr); 604 605 spin_lock_bh(&fnhe_lock); 606 607 hash = nh->nh_exceptions; 608 if (!hash) { 609 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); 610 if (!hash) 611 goto out_unlock; 612 nh->nh_exceptions = hash; 613 } 614 615 hash += hval; 616 617 depth = 0; 618 for (fnhe = rcu_dereference(hash->chain); fnhe; 619 fnhe = rcu_dereference(fnhe->fnhe_next)) { 620 if (fnhe->fnhe_daddr == daddr) 621 break; 622 depth++; 623 } 624 625 if (fnhe) { 626 if (gw) 627 fnhe->fnhe_gw = gw; 628 if (pmtu) { 629 fnhe->fnhe_pmtu = pmtu; 630 fnhe->fnhe_expires = expires; 631 } 632 } else { 633 if (depth > FNHE_RECLAIM_DEPTH) 634 fnhe = fnhe_oldest(hash); 635 else { 636 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 637 if (!fnhe) 638 goto out_unlock; 639 640 fnhe->fnhe_next = hash->chain; 641 rcu_assign_pointer(hash->chain, fnhe); 642 } 643 fnhe->fnhe_daddr = daddr; 644 fnhe->fnhe_gw = gw; 645 fnhe->fnhe_pmtu = pmtu; 646 fnhe->fnhe_expires = expires; 647 } 648 649 fnhe->fnhe_stamp = jiffies; 650 651 out_unlock: 652 spin_unlock_bh(&fnhe_lock); 653 return; 654 } 655 656 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 657 bool kill_route) 658 { 659 __be32 new_gw = icmp_hdr(skb)->un.gateway; 660 __be32 old_gw = ip_hdr(skb)->saddr; 661 struct net_device *dev = skb->dev; 662 struct in_device *in_dev; 663 struct fib_result res; 664 struct neighbour *n; 665 struct net *net; 666 667 switch (icmp_hdr(skb)->code & 7) { 668 case ICMP_REDIR_NET: 669 case ICMP_REDIR_NETTOS: 670 case ICMP_REDIR_HOST: 671 case ICMP_REDIR_HOSTTOS: 672 break; 673 674 default: 675 return; 676 } 677 678 if (rt->rt_gateway != old_gw) 679 return; 680 681 in_dev = __in_dev_get_rcu(dev); 682 if (!in_dev) 683 return; 684 685 net = dev_net(dev); 686 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 687 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 688 ipv4_is_zeronet(new_gw)) 689 goto reject_redirect; 690 691 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 692 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 693 goto reject_redirect; 694 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 695 goto reject_redirect; 696 } else { 697 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 698 goto reject_redirect; 699 } 700 701 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); 702 if (n) { 703 if (!(n->nud_state & NUD_VALID)) { 704 neigh_event_send(n, NULL); 705 } else { 706 if (fib_lookup(net, fl4, &res) == 0) { 707 struct fib_nh *nh = &FIB_RES_NH(res); 708 709 update_or_create_fnhe(nh, fl4->daddr, new_gw, 710 0, 0); 711 } 712 if (kill_route) 713 rt->dst.obsolete = DST_OBSOLETE_KILL; 714 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 715 } 716 neigh_release(n); 717 } 718 return; 719 720 reject_redirect: 721 #ifdef CONFIG_IP_ROUTE_VERBOSE 722 if (IN_DEV_LOG_MARTIANS(in_dev)) { 723 const struct iphdr *iph = (const struct iphdr *) skb->data; 724 __be32 daddr = iph->daddr; 725 __be32 saddr = iph->saddr; 726 727 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 728 " Advised path = %pI4 -> %pI4\n", 729 &old_gw, dev->name, &new_gw, 730 &saddr, &daddr); 731 } 732 #endif 733 ; 734 } 735 736 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 737 { 738 struct rtable *rt; 739 struct flowi4 fl4; 740 741 rt = (struct rtable *) dst; 742 743 ip_rt_build_flow_key(&fl4, sk, skb); 744 __ip_do_redirect(rt, skb, &fl4, true); 745 } 746 747 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 748 { 749 struct rtable *rt = (struct rtable *)dst; 750 struct dst_entry *ret = dst; 751 752 if (rt) { 753 if (dst->obsolete > 0) { 754 ip_rt_put(rt); 755 ret = NULL; 756 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 757 rt->dst.expires) { 758 ip_rt_put(rt); 759 ret = NULL; 760 } 761 } 762 return ret; 763 } 764 765 /* 766 * Algorithm: 767 * 1. The first ip_rt_redirect_number redirects are sent 768 * with exponential backoff, then we stop sending them at all, 769 * assuming that the host ignores our redirects. 770 * 2. If we did not see packets requiring redirects 771 * during ip_rt_redirect_silence, we assume that the host 772 * forgot redirected route and start to send redirects again. 773 * 774 * This algorithm is much cheaper and more intelligent than dumb load limiting 775 * in icmp.c. 776 * 777 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 778 * and "frag. need" (breaks PMTU discovery) in icmp.c. 779 */ 780 781 void ip_rt_send_redirect(struct sk_buff *skb) 782 { 783 struct rtable *rt = skb_rtable(skb); 784 struct in_device *in_dev; 785 struct inet_peer *peer; 786 struct net *net; 787 int log_martians; 788 789 rcu_read_lock(); 790 in_dev = __in_dev_get_rcu(rt->dst.dev); 791 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 792 rcu_read_unlock(); 793 return; 794 } 795 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 796 rcu_read_unlock(); 797 798 net = dev_net(rt->dst.dev); 799 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 800 if (!peer) { 801 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 802 rt_nexthop(rt, ip_hdr(skb)->daddr)); 803 return; 804 } 805 806 /* No redirected packets during ip_rt_redirect_silence; 807 * reset the algorithm. 808 */ 809 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 810 peer->rate_tokens = 0; 811 812 /* Too many ignored redirects; do not send anything 813 * set dst.rate_last to the last seen redirected packet. 814 */ 815 if (peer->rate_tokens >= ip_rt_redirect_number) { 816 peer->rate_last = jiffies; 817 goto out_put_peer; 818 } 819 820 /* Check for load limit; set rate_last to the latest sent 821 * redirect. 822 */ 823 if (peer->rate_tokens == 0 || 824 time_after(jiffies, 825 (peer->rate_last + 826 (ip_rt_redirect_load << peer->rate_tokens)))) { 827 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 828 829 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 830 peer->rate_last = jiffies; 831 ++peer->rate_tokens; 832 #ifdef CONFIG_IP_ROUTE_VERBOSE 833 if (log_martians && 834 peer->rate_tokens == ip_rt_redirect_number) 835 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 836 &ip_hdr(skb)->saddr, inet_iif(skb), 837 &ip_hdr(skb)->daddr, &gw); 838 #endif 839 } 840 out_put_peer: 841 inet_putpeer(peer); 842 } 843 844 static int ip_error(struct sk_buff *skb) 845 { 846 struct in_device *in_dev = __in_dev_get_rcu(skb->dev); 847 struct rtable *rt = skb_rtable(skb); 848 struct inet_peer *peer; 849 unsigned long now; 850 struct net *net; 851 bool send; 852 int code; 853 854 net = dev_net(rt->dst.dev); 855 if (!IN_DEV_FORWARD(in_dev)) { 856 switch (rt->dst.error) { 857 case EHOSTUNREACH: 858 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); 859 break; 860 861 case ENETUNREACH: 862 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 863 break; 864 } 865 goto out; 866 } 867 868 switch (rt->dst.error) { 869 case EINVAL: 870 default: 871 goto out; 872 case EHOSTUNREACH: 873 code = ICMP_HOST_UNREACH; 874 break; 875 case ENETUNREACH: 876 code = ICMP_NET_UNREACH; 877 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 878 break; 879 case EACCES: 880 code = ICMP_PKT_FILTERED; 881 break; 882 } 883 884 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1); 885 886 send = true; 887 if (peer) { 888 now = jiffies; 889 peer->rate_tokens += now - peer->rate_last; 890 if (peer->rate_tokens > ip_rt_error_burst) 891 peer->rate_tokens = ip_rt_error_burst; 892 peer->rate_last = now; 893 if (peer->rate_tokens >= ip_rt_error_cost) 894 peer->rate_tokens -= ip_rt_error_cost; 895 else 896 send = false; 897 inet_putpeer(peer); 898 } 899 if (send) 900 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 901 902 out: kfree_skb(skb); 903 return 0; 904 } 905 906 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 907 { 908 struct dst_entry *dst = &rt->dst; 909 struct fib_result res; 910 911 if (dst_metric_locked(dst, RTAX_MTU)) 912 return; 913 914 if (dst->dev->mtu < mtu) 915 return; 916 917 if (mtu < ip_rt_min_pmtu) 918 mtu = ip_rt_min_pmtu; 919 920 if (!rt->rt_pmtu) { 921 dst->obsolete = DST_OBSOLETE_KILL; 922 } else { 923 rt->rt_pmtu = mtu; 924 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires); 925 } 926 927 rcu_read_lock(); 928 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) { 929 struct fib_nh *nh = &FIB_RES_NH(res); 930 931 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, 932 jiffies + ip_rt_mtu_expires); 933 } 934 rcu_read_unlock(); 935 } 936 937 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 938 struct sk_buff *skb, u32 mtu) 939 { 940 struct rtable *rt = (struct rtable *) dst; 941 struct flowi4 fl4; 942 943 ip_rt_build_flow_key(&fl4, sk, skb); 944 __ip_rt_update_pmtu(rt, &fl4, mtu); 945 } 946 947 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 948 int oif, u32 mark, u8 protocol, int flow_flags) 949 { 950 const struct iphdr *iph = (const struct iphdr *) skb->data; 951 struct flowi4 fl4; 952 struct rtable *rt; 953 954 __build_flow_key(&fl4, NULL, iph, oif, 955 RT_TOS(iph->tos), protocol, mark, flow_flags); 956 rt = __ip_route_output_key(net, &fl4); 957 if (!IS_ERR(rt)) { 958 __ip_rt_update_pmtu(rt, &fl4, mtu); 959 ip_rt_put(rt); 960 } 961 } 962 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 963 964 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 965 { 966 const struct iphdr *iph = (const struct iphdr *) skb->data; 967 struct flowi4 fl4; 968 struct rtable *rt; 969 970 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 971 rt = __ip_route_output_key(sock_net(sk), &fl4); 972 if (!IS_ERR(rt)) { 973 __ip_rt_update_pmtu(rt, &fl4, mtu); 974 ip_rt_put(rt); 975 } 976 } 977 978 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 979 { 980 const struct iphdr *iph = (const struct iphdr *) skb->data; 981 struct flowi4 fl4; 982 struct rtable *rt; 983 struct dst_entry *dst; 984 bool new = false; 985 986 bh_lock_sock(sk); 987 rt = (struct rtable *) __sk_dst_get(sk); 988 989 if (sock_owned_by_user(sk) || !rt) { 990 __ipv4_sk_update_pmtu(skb, sk, mtu); 991 goto out; 992 } 993 994 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 995 996 if (!__sk_dst_check(sk, 0)) { 997 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 998 if (IS_ERR(rt)) 999 goto out; 1000 1001 new = true; 1002 } 1003 1004 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); 1005 1006 dst = dst_check(&rt->dst, 0); 1007 if (!dst) { 1008 if (new) 1009 dst_release(&rt->dst); 1010 1011 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1012 if (IS_ERR(rt)) 1013 goto out; 1014 1015 new = true; 1016 } 1017 1018 if (new) 1019 __sk_dst_set(sk, &rt->dst); 1020 1021 out: 1022 bh_unlock_sock(sk); 1023 } 1024 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1025 1026 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1027 int oif, u32 mark, u8 protocol, int flow_flags) 1028 { 1029 const struct iphdr *iph = (const struct iphdr *) skb->data; 1030 struct flowi4 fl4; 1031 struct rtable *rt; 1032 1033 __build_flow_key(&fl4, NULL, iph, oif, 1034 RT_TOS(iph->tos), protocol, mark, flow_flags); 1035 rt = __ip_route_output_key(net, &fl4); 1036 if (!IS_ERR(rt)) { 1037 __ip_do_redirect(rt, skb, &fl4, false); 1038 ip_rt_put(rt); 1039 } 1040 } 1041 EXPORT_SYMBOL_GPL(ipv4_redirect); 1042 1043 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1044 { 1045 const struct iphdr *iph = (const struct iphdr *) skb->data; 1046 struct flowi4 fl4; 1047 struct rtable *rt; 1048 1049 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1050 rt = __ip_route_output_key(sock_net(sk), &fl4); 1051 if (!IS_ERR(rt)) { 1052 __ip_do_redirect(rt, skb, &fl4, false); 1053 ip_rt_put(rt); 1054 } 1055 } 1056 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1057 1058 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1059 { 1060 struct rtable *rt = (struct rtable *) dst; 1061 1062 /* All IPV4 dsts are created with ->obsolete set to the value 1063 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1064 * into this function always. 1065 * 1066 * When a PMTU/redirect information update invalidates a 1067 * route, this is indicated by setting obsolete to 1068 * DST_OBSOLETE_KILL. 1069 */ 1070 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt)) 1071 return NULL; 1072 return dst; 1073 } 1074 1075 static void ipv4_link_failure(struct sk_buff *skb) 1076 { 1077 struct rtable *rt; 1078 1079 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1080 1081 rt = skb_rtable(skb); 1082 if (rt) 1083 dst_set_expires(&rt->dst, 0); 1084 } 1085 1086 static int ip_rt_bug(struct sk_buff *skb) 1087 { 1088 pr_debug("%s: %pI4 -> %pI4, %s\n", 1089 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1090 skb->dev ? skb->dev->name : "?"); 1091 kfree_skb(skb); 1092 WARN_ON(1); 1093 return 0; 1094 } 1095 1096 /* 1097 We do not cache source address of outgoing interface, 1098 because it is used only by IP RR, TS and SRR options, 1099 so that it out of fast path. 1100 1101 BTW remember: "addr" is allowed to be not aligned 1102 in IP options! 1103 */ 1104 1105 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1106 { 1107 __be32 src; 1108 1109 if (rt_is_output_route(rt)) 1110 src = ip_hdr(skb)->saddr; 1111 else { 1112 struct fib_result res; 1113 struct flowi4 fl4; 1114 struct iphdr *iph; 1115 1116 iph = ip_hdr(skb); 1117 1118 memset(&fl4, 0, sizeof(fl4)); 1119 fl4.daddr = iph->daddr; 1120 fl4.saddr = iph->saddr; 1121 fl4.flowi4_tos = RT_TOS(iph->tos); 1122 fl4.flowi4_oif = rt->dst.dev->ifindex; 1123 fl4.flowi4_iif = skb->dev->ifindex; 1124 fl4.flowi4_mark = skb->mark; 1125 1126 rcu_read_lock(); 1127 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1128 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1129 else 1130 src = inet_select_addr(rt->dst.dev, 1131 rt_nexthop(rt, iph->daddr), 1132 RT_SCOPE_UNIVERSE); 1133 rcu_read_unlock(); 1134 } 1135 memcpy(addr, &src, 4); 1136 } 1137 1138 #ifdef CONFIG_IP_ROUTE_CLASSID 1139 static void set_class_tag(struct rtable *rt, u32 tag) 1140 { 1141 if (!(rt->dst.tclassid & 0xFFFF)) 1142 rt->dst.tclassid |= tag & 0xFFFF; 1143 if (!(rt->dst.tclassid & 0xFFFF0000)) 1144 rt->dst.tclassid |= tag & 0xFFFF0000; 1145 } 1146 #endif 1147 1148 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1149 { 1150 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1151 1152 if (advmss == 0) { 1153 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1154 ip_rt_min_advmss); 1155 if (advmss > 65535 - 40) 1156 advmss = 65535 - 40; 1157 } 1158 return advmss; 1159 } 1160 1161 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1162 { 1163 const struct rtable *rt = (const struct rtable *) dst; 1164 unsigned int mtu = rt->rt_pmtu; 1165 1166 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1167 mtu = dst_metric_raw(dst, RTAX_MTU); 1168 1169 if (mtu) 1170 return mtu; 1171 1172 mtu = dst->dev->mtu; 1173 1174 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1175 if (rt->rt_uses_gateway && mtu > 576) 1176 mtu = 576; 1177 } 1178 1179 if (mtu > IP_MAX_MTU) 1180 mtu = IP_MAX_MTU; 1181 1182 return mtu; 1183 } 1184 1185 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1186 { 1187 struct fnhe_hash_bucket *hash = nh->nh_exceptions; 1188 struct fib_nh_exception *fnhe; 1189 u32 hval; 1190 1191 if (!hash) 1192 return NULL; 1193 1194 hval = fnhe_hashfun(daddr); 1195 1196 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1197 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1198 if (fnhe->fnhe_daddr == daddr) 1199 return fnhe; 1200 } 1201 return NULL; 1202 } 1203 1204 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1205 __be32 daddr) 1206 { 1207 bool ret = false; 1208 1209 spin_lock_bh(&fnhe_lock); 1210 1211 if (daddr == fnhe->fnhe_daddr) { 1212 struct rtable *orig = rcu_dereference(fnhe->fnhe_rth); 1213 if (orig && rt_is_expired(orig)) { 1214 fnhe->fnhe_gw = 0; 1215 fnhe->fnhe_pmtu = 0; 1216 fnhe->fnhe_expires = 0; 1217 } 1218 if (fnhe->fnhe_pmtu) { 1219 unsigned long expires = fnhe->fnhe_expires; 1220 unsigned long diff = expires - jiffies; 1221 1222 if (time_before(jiffies, expires)) { 1223 rt->rt_pmtu = fnhe->fnhe_pmtu; 1224 dst_set_expires(&rt->dst, diff); 1225 } 1226 } 1227 if (fnhe->fnhe_gw) { 1228 rt->rt_flags |= RTCF_REDIRECTED; 1229 rt->rt_gateway = fnhe->fnhe_gw; 1230 rt->rt_uses_gateway = 1; 1231 } else if (!rt->rt_gateway) 1232 rt->rt_gateway = daddr; 1233 1234 rcu_assign_pointer(fnhe->fnhe_rth, rt); 1235 if (orig) 1236 rt_free(orig); 1237 1238 fnhe->fnhe_stamp = jiffies; 1239 ret = true; 1240 } 1241 spin_unlock_bh(&fnhe_lock); 1242 1243 return ret; 1244 } 1245 1246 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1247 { 1248 struct rtable *orig, *prev, **p; 1249 bool ret = true; 1250 1251 if (rt_is_input_route(rt)) { 1252 p = (struct rtable **)&nh->nh_rth_input; 1253 } else { 1254 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output); 1255 } 1256 orig = *p; 1257 1258 prev = cmpxchg(p, orig, rt); 1259 if (prev == orig) { 1260 if (orig) 1261 rt_free(orig); 1262 } else 1263 ret = false; 1264 1265 return ret; 1266 } 1267 1268 static DEFINE_SPINLOCK(rt_uncached_lock); 1269 static LIST_HEAD(rt_uncached_list); 1270 1271 static void rt_add_uncached_list(struct rtable *rt) 1272 { 1273 spin_lock_bh(&rt_uncached_lock); 1274 list_add_tail(&rt->rt_uncached, &rt_uncached_list); 1275 spin_unlock_bh(&rt_uncached_lock); 1276 } 1277 1278 static void ipv4_dst_destroy(struct dst_entry *dst) 1279 { 1280 struct rtable *rt = (struct rtable *) dst; 1281 1282 if (!list_empty(&rt->rt_uncached)) { 1283 spin_lock_bh(&rt_uncached_lock); 1284 list_del(&rt->rt_uncached); 1285 spin_unlock_bh(&rt_uncached_lock); 1286 } 1287 } 1288 1289 void rt_flush_dev(struct net_device *dev) 1290 { 1291 if (!list_empty(&rt_uncached_list)) { 1292 struct net *net = dev_net(dev); 1293 struct rtable *rt; 1294 1295 spin_lock_bh(&rt_uncached_lock); 1296 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) { 1297 if (rt->dst.dev != dev) 1298 continue; 1299 rt->dst.dev = net->loopback_dev; 1300 dev_hold(rt->dst.dev); 1301 dev_put(dev); 1302 } 1303 spin_unlock_bh(&rt_uncached_lock); 1304 } 1305 } 1306 1307 static bool rt_cache_valid(const struct rtable *rt) 1308 { 1309 return rt && 1310 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1311 !rt_is_expired(rt); 1312 } 1313 1314 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1315 const struct fib_result *res, 1316 struct fib_nh_exception *fnhe, 1317 struct fib_info *fi, u16 type, u32 itag) 1318 { 1319 bool cached = false; 1320 1321 if (fi) { 1322 struct fib_nh *nh = &FIB_RES_NH(*res); 1323 1324 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1325 rt->rt_gateway = nh->nh_gw; 1326 rt->rt_uses_gateway = 1; 1327 } 1328 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1329 #ifdef CONFIG_IP_ROUTE_CLASSID 1330 rt->dst.tclassid = nh->nh_tclassid; 1331 #endif 1332 if (unlikely(fnhe)) 1333 cached = rt_bind_exception(rt, fnhe, daddr); 1334 else if (!(rt->dst.flags & DST_NOCACHE)) 1335 cached = rt_cache_route(nh, rt); 1336 if (unlikely(!cached)) { 1337 /* Routes we intend to cache in nexthop exception or 1338 * FIB nexthop have the DST_NOCACHE bit clear. 1339 * However, if we are unsuccessful at storing this 1340 * route into the cache we really need to set it. 1341 */ 1342 rt->dst.flags |= DST_NOCACHE; 1343 if (!rt->rt_gateway) 1344 rt->rt_gateway = daddr; 1345 rt_add_uncached_list(rt); 1346 } 1347 } else 1348 rt_add_uncached_list(rt); 1349 1350 #ifdef CONFIG_IP_ROUTE_CLASSID 1351 #ifdef CONFIG_IP_MULTIPLE_TABLES 1352 set_class_tag(rt, res->tclassid); 1353 #endif 1354 set_class_tag(rt, itag); 1355 #endif 1356 } 1357 1358 static struct rtable *rt_dst_alloc(struct net_device *dev, 1359 bool nopolicy, bool noxfrm, bool will_cache) 1360 { 1361 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1362 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1363 (nopolicy ? DST_NOPOLICY : 0) | 1364 (noxfrm ? DST_NOXFRM : 0)); 1365 } 1366 1367 /* called in rcu_read_lock() section */ 1368 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1369 u8 tos, struct net_device *dev, int our) 1370 { 1371 struct rtable *rth; 1372 struct in_device *in_dev = __in_dev_get_rcu(dev); 1373 u32 itag = 0; 1374 int err; 1375 1376 /* Primary sanity checks. */ 1377 1378 if (in_dev == NULL) 1379 return -EINVAL; 1380 1381 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1382 skb->protocol != htons(ETH_P_IP)) 1383 goto e_inval; 1384 1385 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1386 if (ipv4_is_loopback(saddr)) 1387 goto e_inval; 1388 1389 if (ipv4_is_zeronet(saddr)) { 1390 if (!ipv4_is_local_multicast(daddr)) 1391 goto e_inval; 1392 } else { 1393 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1394 in_dev, &itag); 1395 if (err < 0) 1396 goto e_err; 1397 } 1398 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, 1399 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1400 if (!rth) 1401 goto e_nobufs; 1402 1403 #ifdef CONFIG_IP_ROUTE_CLASSID 1404 rth->dst.tclassid = itag; 1405 #endif 1406 rth->dst.output = ip_rt_bug; 1407 1408 rth->rt_genid = rt_genid(dev_net(dev)); 1409 rth->rt_flags = RTCF_MULTICAST; 1410 rth->rt_type = RTN_MULTICAST; 1411 rth->rt_is_input= 1; 1412 rth->rt_iif = 0; 1413 rth->rt_pmtu = 0; 1414 rth->rt_gateway = 0; 1415 rth->rt_uses_gateway = 0; 1416 INIT_LIST_HEAD(&rth->rt_uncached); 1417 if (our) { 1418 rth->dst.input= ip_local_deliver; 1419 rth->rt_flags |= RTCF_LOCAL; 1420 } 1421 1422 #ifdef CONFIG_IP_MROUTE 1423 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1424 rth->dst.input = ip_mr_input; 1425 #endif 1426 RT_CACHE_STAT_INC(in_slow_mc); 1427 1428 skb_dst_set(skb, &rth->dst); 1429 return 0; 1430 1431 e_nobufs: 1432 return -ENOBUFS; 1433 e_inval: 1434 return -EINVAL; 1435 e_err: 1436 return err; 1437 } 1438 1439 1440 static void ip_handle_martian_source(struct net_device *dev, 1441 struct in_device *in_dev, 1442 struct sk_buff *skb, 1443 __be32 daddr, 1444 __be32 saddr) 1445 { 1446 RT_CACHE_STAT_INC(in_martian_src); 1447 #ifdef CONFIG_IP_ROUTE_VERBOSE 1448 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1449 /* 1450 * RFC1812 recommendation, if source is martian, 1451 * the only hint is MAC header. 1452 */ 1453 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1454 &daddr, &saddr, dev->name); 1455 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1456 print_hex_dump(KERN_WARNING, "ll header: ", 1457 DUMP_PREFIX_OFFSET, 16, 1, 1458 skb_mac_header(skb), 1459 dev->hard_header_len, true); 1460 } 1461 } 1462 #endif 1463 } 1464 1465 /* called in rcu_read_lock() section */ 1466 static int __mkroute_input(struct sk_buff *skb, 1467 const struct fib_result *res, 1468 struct in_device *in_dev, 1469 __be32 daddr, __be32 saddr, u32 tos) 1470 { 1471 struct rtable *rth; 1472 int err; 1473 struct in_device *out_dev; 1474 unsigned int flags = 0; 1475 bool do_cache; 1476 u32 itag; 1477 1478 /* get a working reference to the output device */ 1479 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1480 if (out_dev == NULL) { 1481 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1482 return -EINVAL; 1483 } 1484 1485 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1486 in_dev->dev, in_dev, &itag); 1487 if (err < 0) { 1488 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1489 saddr); 1490 1491 goto cleanup; 1492 } 1493 1494 do_cache = res->fi && !itag; 1495 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1496 (IN_DEV_SHARED_MEDIA(out_dev) || 1497 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) { 1498 flags |= RTCF_DOREDIRECT; 1499 do_cache = false; 1500 } 1501 1502 if (skb->protocol != htons(ETH_P_IP)) { 1503 /* Not IP (i.e. ARP). Do not create route, if it is 1504 * invalid for proxy arp. DNAT routes are always valid. 1505 * 1506 * Proxy arp feature have been extended to allow, ARP 1507 * replies back to the same interface, to support 1508 * Private VLAN switch technologies. See arp.c. 1509 */ 1510 if (out_dev == in_dev && 1511 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1512 err = -EINVAL; 1513 goto cleanup; 1514 } 1515 } 1516 1517 if (do_cache) { 1518 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1519 if (rt_cache_valid(rth)) { 1520 skb_dst_set_noref(skb, &rth->dst); 1521 goto out; 1522 } 1523 } 1524 1525 rth = rt_dst_alloc(out_dev->dev, 1526 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1527 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1528 if (!rth) { 1529 err = -ENOBUFS; 1530 goto cleanup; 1531 } 1532 1533 rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); 1534 rth->rt_flags = flags; 1535 rth->rt_type = res->type; 1536 rth->rt_is_input = 1; 1537 rth->rt_iif = 0; 1538 rth->rt_pmtu = 0; 1539 rth->rt_gateway = 0; 1540 rth->rt_uses_gateway = 0; 1541 INIT_LIST_HEAD(&rth->rt_uncached); 1542 1543 rth->dst.input = ip_forward; 1544 rth->dst.output = ip_output; 1545 1546 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag); 1547 skb_dst_set(skb, &rth->dst); 1548 out: 1549 err = 0; 1550 cleanup: 1551 return err; 1552 } 1553 1554 static int ip_mkroute_input(struct sk_buff *skb, 1555 struct fib_result *res, 1556 const struct flowi4 *fl4, 1557 struct in_device *in_dev, 1558 __be32 daddr, __be32 saddr, u32 tos) 1559 { 1560 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1561 if (res->fi && res->fi->fib_nhs > 1) 1562 fib_select_multipath(res); 1563 #endif 1564 1565 /* create a routing cache entry */ 1566 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1567 } 1568 1569 /* 1570 * NOTE. We drop all the packets that has local source 1571 * addresses, because every properly looped back packet 1572 * must have correct destination already attached by output routine. 1573 * 1574 * Such approach solves two big problems: 1575 * 1. Not simplex devices are handled properly. 1576 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1577 * called with rcu_read_lock() 1578 */ 1579 1580 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1581 u8 tos, struct net_device *dev) 1582 { 1583 struct fib_result res; 1584 struct in_device *in_dev = __in_dev_get_rcu(dev); 1585 struct flowi4 fl4; 1586 unsigned int flags = 0; 1587 u32 itag = 0; 1588 struct rtable *rth; 1589 int err = -EINVAL; 1590 struct net *net = dev_net(dev); 1591 bool do_cache; 1592 1593 /* IP on this device is disabled. */ 1594 1595 if (!in_dev) 1596 goto out; 1597 1598 /* Check for the most weird martians, which can be not detected 1599 by fib_lookup. 1600 */ 1601 1602 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1603 goto martian_source; 1604 1605 res.fi = NULL; 1606 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1607 goto brd_input; 1608 1609 /* Accept zero addresses only to limited broadcast; 1610 * I even do not know to fix it or not. Waiting for complains :-) 1611 */ 1612 if (ipv4_is_zeronet(saddr)) 1613 goto martian_source; 1614 1615 if (ipv4_is_zeronet(daddr)) 1616 goto martian_destination; 1617 1618 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1619 * and call it once if daddr or/and saddr are loopback addresses 1620 */ 1621 if (ipv4_is_loopback(daddr)) { 1622 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1623 goto martian_destination; 1624 } else if (ipv4_is_loopback(saddr)) { 1625 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1626 goto martian_source; 1627 } 1628 1629 /* 1630 * Now we are ready to route packet. 1631 */ 1632 fl4.flowi4_oif = 0; 1633 fl4.flowi4_iif = dev->ifindex; 1634 fl4.flowi4_mark = skb->mark; 1635 fl4.flowi4_tos = tos; 1636 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1637 fl4.daddr = daddr; 1638 fl4.saddr = saddr; 1639 err = fib_lookup(net, &fl4, &res); 1640 if (err != 0) 1641 goto no_route; 1642 1643 RT_CACHE_STAT_INC(in_slow_tot); 1644 1645 if (res.type == RTN_BROADCAST) 1646 goto brd_input; 1647 1648 if (res.type == RTN_LOCAL) { 1649 err = fib_validate_source(skb, saddr, daddr, tos, 1650 LOOPBACK_IFINDEX, 1651 dev, in_dev, &itag); 1652 if (err < 0) 1653 goto martian_source_keep_err; 1654 goto local_input; 1655 } 1656 1657 if (!IN_DEV_FORWARD(in_dev)) 1658 goto no_route; 1659 if (res.type != RTN_UNICAST) 1660 goto martian_destination; 1661 1662 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1663 out: return err; 1664 1665 brd_input: 1666 if (skb->protocol != htons(ETH_P_IP)) 1667 goto e_inval; 1668 1669 if (!ipv4_is_zeronet(saddr)) { 1670 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1671 in_dev, &itag); 1672 if (err < 0) 1673 goto martian_source_keep_err; 1674 } 1675 flags |= RTCF_BROADCAST; 1676 res.type = RTN_BROADCAST; 1677 RT_CACHE_STAT_INC(in_brd); 1678 1679 local_input: 1680 do_cache = false; 1681 if (res.fi) { 1682 if (!itag) { 1683 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1684 if (rt_cache_valid(rth)) { 1685 skb_dst_set_noref(skb, &rth->dst); 1686 err = 0; 1687 goto out; 1688 } 1689 do_cache = true; 1690 } 1691 } 1692 1693 rth = rt_dst_alloc(net->loopback_dev, 1694 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1695 if (!rth) 1696 goto e_nobufs; 1697 1698 rth->dst.input= ip_local_deliver; 1699 rth->dst.output= ip_rt_bug; 1700 #ifdef CONFIG_IP_ROUTE_CLASSID 1701 rth->dst.tclassid = itag; 1702 #endif 1703 1704 rth->rt_genid = rt_genid(net); 1705 rth->rt_flags = flags|RTCF_LOCAL; 1706 rth->rt_type = res.type; 1707 rth->rt_is_input = 1; 1708 rth->rt_iif = 0; 1709 rth->rt_pmtu = 0; 1710 rth->rt_gateway = 0; 1711 rth->rt_uses_gateway = 0; 1712 INIT_LIST_HEAD(&rth->rt_uncached); 1713 if (res.type == RTN_UNREACHABLE) { 1714 rth->dst.input= ip_error; 1715 rth->dst.error= -err; 1716 rth->rt_flags &= ~RTCF_LOCAL; 1717 } 1718 if (do_cache) 1719 rt_cache_route(&FIB_RES_NH(res), rth); 1720 skb_dst_set(skb, &rth->dst); 1721 err = 0; 1722 goto out; 1723 1724 no_route: 1725 RT_CACHE_STAT_INC(in_no_route); 1726 res.type = RTN_UNREACHABLE; 1727 if (err == -ESRCH) 1728 err = -ENETUNREACH; 1729 goto local_input; 1730 1731 /* 1732 * Do not cache martian addresses: they should be logged (RFC1812) 1733 */ 1734 martian_destination: 1735 RT_CACHE_STAT_INC(in_martian_dst); 1736 #ifdef CONFIG_IP_ROUTE_VERBOSE 1737 if (IN_DEV_LOG_MARTIANS(in_dev)) 1738 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1739 &daddr, &saddr, dev->name); 1740 #endif 1741 1742 e_inval: 1743 err = -EINVAL; 1744 goto out; 1745 1746 e_nobufs: 1747 err = -ENOBUFS; 1748 goto out; 1749 1750 martian_source: 1751 err = -EINVAL; 1752 martian_source_keep_err: 1753 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1754 goto out; 1755 } 1756 1757 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1758 u8 tos, struct net_device *dev) 1759 { 1760 int res; 1761 1762 rcu_read_lock(); 1763 1764 /* Multicast recognition logic is moved from route cache to here. 1765 The problem was that too many Ethernet cards have broken/missing 1766 hardware multicast filters :-( As result the host on multicasting 1767 network acquires a lot of useless route cache entries, sort of 1768 SDR messages from all the world. Now we try to get rid of them. 1769 Really, provided software IP multicast filter is organized 1770 reasonably (at least, hashed), it does not result in a slowdown 1771 comparing with route cache reject entries. 1772 Note, that multicast routers are not affected, because 1773 route cache entry is created eventually. 1774 */ 1775 if (ipv4_is_multicast(daddr)) { 1776 struct in_device *in_dev = __in_dev_get_rcu(dev); 1777 1778 if (in_dev) { 1779 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1780 ip_hdr(skb)->protocol); 1781 if (our 1782 #ifdef CONFIG_IP_MROUTE 1783 || 1784 (!ipv4_is_local_multicast(daddr) && 1785 IN_DEV_MFORWARD(in_dev)) 1786 #endif 1787 ) { 1788 int res = ip_route_input_mc(skb, daddr, saddr, 1789 tos, dev, our); 1790 rcu_read_unlock(); 1791 return res; 1792 } 1793 } 1794 rcu_read_unlock(); 1795 return -EINVAL; 1796 } 1797 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1798 rcu_read_unlock(); 1799 return res; 1800 } 1801 EXPORT_SYMBOL(ip_route_input_noref); 1802 1803 /* called with rcu_read_lock() */ 1804 static struct rtable *__mkroute_output(const struct fib_result *res, 1805 const struct flowi4 *fl4, int orig_oif, 1806 struct net_device *dev_out, 1807 unsigned int flags) 1808 { 1809 struct fib_info *fi = res->fi; 1810 struct fib_nh_exception *fnhe; 1811 struct in_device *in_dev; 1812 u16 type = res->type; 1813 struct rtable *rth; 1814 bool do_cache; 1815 1816 in_dev = __in_dev_get_rcu(dev_out); 1817 if (!in_dev) 1818 return ERR_PTR(-EINVAL); 1819 1820 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1821 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1822 return ERR_PTR(-EINVAL); 1823 1824 if (ipv4_is_lbcast(fl4->daddr)) 1825 type = RTN_BROADCAST; 1826 else if (ipv4_is_multicast(fl4->daddr)) 1827 type = RTN_MULTICAST; 1828 else if (ipv4_is_zeronet(fl4->daddr)) 1829 return ERR_PTR(-EINVAL); 1830 1831 if (dev_out->flags & IFF_LOOPBACK) 1832 flags |= RTCF_LOCAL; 1833 1834 do_cache = true; 1835 if (type == RTN_BROADCAST) { 1836 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1837 fi = NULL; 1838 } else if (type == RTN_MULTICAST) { 1839 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1840 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1841 fl4->flowi4_proto)) 1842 flags &= ~RTCF_LOCAL; 1843 else 1844 do_cache = false; 1845 /* If multicast route do not exist use 1846 * default one, but do not gateway in this case. 1847 * Yes, it is hack. 1848 */ 1849 if (fi && res->prefixlen < 4) 1850 fi = NULL; 1851 } 1852 1853 fnhe = NULL; 1854 do_cache &= fi != NULL; 1855 if (do_cache) { 1856 struct rtable __rcu **prth; 1857 struct fib_nh *nh = &FIB_RES_NH(*res); 1858 1859 fnhe = find_exception(nh, fl4->daddr); 1860 if (fnhe) 1861 prth = &fnhe->fnhe_rth; 1862 else { 1863 if (unlikely(fl4->flowi4_flags & 1864 FLOWI_FLAG_KNOWN_NH && 1865 !(nh->nh_gw && 1866 nh->nh_scope == RT_SCOPE_LINK))) { 1867 do_cache = false; 1868 goto add; 1869 } 1870 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output); 1871 } 1872 rth = rcu_dereference(*prth); 1873 if (rt_cache_valid(rth)) { 1874 dst_hold(&rth->dst); 1875 return rth; 1876 } 1877 } 1878 1879 add: 1880 rth = rt_dst_alloc(dev_out, 1881 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1882 IN_DEV_CONF_GET(in_dev, NOXFRM), 1883 do_cache); 1884 if (!rth) 1885 return ERR_PTR(-ENOBUFS); 1886 1887 rth->dst.output = ip_output; 1888 1889 rth->rt_genid = rt_genid(dev_net(dev_out)); 1890 rth->rt_flags = flags; 1891 rth->rt_type = type; 1892 rth->rt_is_input = 0; 1893 rth->rt_iif = orig_oif ? : 0; 1894 rth->rt_pmtu = 0; 1895 rth->rt_gateway = 0; 1896 rth->rt_uses_gateway = 0; 1897 INIT_LIST_HEAD(&rth->rt_uncached); 1898 1899 RT_CACHE_STAT_INC(out_slow_tot); 1900 1901 if (flags & RTCF_LOCAL) 1902 rth->dst.input = ip_local_deliver; 1903 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 1904 if (flags & RTCF_LOCAL && 1905 !(dev_out->flags & IFF_LOOPBACK)) { 1906 rth->dst.output = ip_mc_output; 1907 RT_CACHE_STAT_INC(out_slow_mc); 1908 } 1909 #ifdef CONFIG_IP_MROUTE 1910 if (type == RTN_MULTICAST) { 1911 if (IN_DEV_MFORWARD(in_dev) && 1912 !ipv4_is_local_multicast(fl4->daddr)) { 1913 rth->dst.input = ip_mr_input; 1914 rth->dst.output = ip_mc_output; 1915 } 1916 } 1917 #endif 1918 } 1919 1920 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 1921 1922 return rth; 1923 } 1924 1925 /* 1926 * Major route resolver routine. 1927 */ 1928 1929 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 1930 { 1931 struct net_device *dev_out = NULL; 1932 __u8 tos = RT_FL_TOS(fl4); 1933 unsigned int flags = 0; 1934 struct fib_result res; 1935 struct rtable *rth; 1936 int orig_oif; 1937 1938 res.tclassid = 0; 1939 res.fi = NULL; 1940 res.table = NULL; 1941 1942 orig_oif = fl4->flowi4_oif; 1943 1944 fl4->flowi4_iif = LOOPBACK_IFINDEX; 1945 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 1946 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 1947 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 1948 1949 rcu_read_lock(); 1950 if (fl4->saddr) { 1951 rth = ERR_PTR(-EINVAL); 1952 if (ipv4_is_multicast(fl4->saddr) || 1953 ipv4_is_lbcast(fl4->saddr) || 1954 ipv4_is_zeronet(fl4->saddr)) 1955 goto out; 1956 1957 /* I removed check for oif == dev_out->oif here. 1958 It was wrong for two reasons: 1959 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 1960 is assigned to multiple interfaces. 1961 2. Moreover, we are allowed to send packets with saddr 1962 of another iface. --ANK 1963 */ 1964 1965 if (fl4->flowi4_oif == 0 && 1966 (ipv4_is_multicast(fl4->daddr) || 1967 ipv4_is_lbcast(fl4->daddr))) { 1968 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 1969 dev_out = __ip_dev_find(net, fl4->saddr, false); 1970 if (dev_out == NULL) 1971 goto out; 1972 1973 /* Special hack: user can direct multicasts 1974 and limited broadcast via necessary interface 1975 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 1976 This hack is not just for fun, it allows 1977 vic,vat and friends to work. 1978 They bind socket to loopback, set ttl to zero 1979 and expect that it will work. 1980 From the viewpoint of routing cache they are broken, 1981 because we are not allowed to build multicast path 1982 with loopback source addr (look, routing cache 1983 cannot know, that ttl is zero, so that packet 1984 will not leave this host and route is valid). 1985 Luckily, this hack is good workaround. 1986 */ 1987 1988 fl4->flowi4_oif = dev_out->ifindex; 1989 goto make_route; 1990 } 1991 1992 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 1993 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 1994 if (!__ip_dev_find(net, fl4->saddr, false)) 1995 goto out; 1996 } 1997 } 1998 1999 2000 if (fl4->flowi4_oif) { 2001 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2002 rth = ERR_PTR(-ENODEV); 2003 if (dev_out == NULL) 2004 goto out; 2005 2006 /* RACE: Check return value of inet_select_addr instead. */ 2007 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2008 rth = ERR_PTR(-ENETUNREACH); 2009 goto out; 2010 } 2011 if (ipv4_is_local_multicast(fl4->daddr) || 2012 ipv4_is_lbcast(fl4->daddr)) { 2013 if (!fl4->saddr) 2014 fl4->saddr = inet_select_addr(dev_out, 0, 2015 RT_SCOPE_LINK); 2016 goto make_route; 2017 } 2018 if (fl4->saddr) { 2019 if (ipv4_is_multicast(fl4->daddr)) 2020 fl4->saddr = inet_select_addr(dev_out, 0, 2021 fl4->flowi4_scope); 2022 else if (!fl4->daddr) 2023 fl4->saddr = inet_select_addr(dev_out, 0, 2024 RT_SCOPE_HOST); 2025 } 2026 } 2027 2028 if (!fl4->daddr) { 2029 fl4->daddr = fl4->saddr; 2030 if (!fl4->daddr) 2031 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2032 dev_out = net->loopback_dev; 2033 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2034 res.type = RTN_LOCAL; 2035 flags |= RTCF_LOCAL; 2036 goto make_route; 2037 } 2038 2039 if (fib_lookup(net, fl4, &res)) { 2040 res.fi = NULL; 2041 res.table = NULL; 2042 if (fl4->flowi4_oif) { 2043 /* Apparently, routing tables are wrong. Assume, 2044 that the destination is on link. 2045 2046 WHY? DW. 2047 Because we are allowed to send to iface 2048 even if it has NO routes and NO assigned 2049 addresses. When oif is specified, routing 2050 tables are looked up with only one purpose: 2051 to catch if destination is gatewayed, rather than 2052 direct. Moreover, if MSG_DONTROUTE is set, 2053 we send packet, ignoring both routing tables 2054 and ifaddr state. --ANK 2055 2056 2057 We could make it even if oif is unknown, 2058 likely IPv6, but we do not. 2059 */ 2060 2061 if (fl4->saddr == 0) 2062 fl4->saddr = inet_select_addr(dev_out, 0, 2063 RT_SCOPE_LINK); 2064 res.type = RTN_UNICAST; 2065 goto make_route; 2066 } 2067 rth = ERR_PTR(-ENETUNREACH); 2068 goto out; 2069 } 2070 2071 if (res.type == RTN_LOCAL) { 2072 if (!fl4->saddr) { 2073 if (res.fi->fib_prefsrc) 2074 fl4->saddr = res.fi->fib_prefsrc; 2075 else 2076 fl4->saddr = fl4->daddr; 2077 } 2078 dev_out = net->loopback_dev; 2079 fl4->flowi4_oif = dev_out->ifindex; 2080 flags |= RTCF_LOCAL; 2081 goto make_route; 2082 } 2083 2084 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2085 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2086 fib_select_multipath(&res); 2087 else 2088 #endif 2089 if (!res.prefixlen && 2090 res.table->tb_num_default > 1 && 2091 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2092 fib_select_default(&res); 2093 2094 if (!fl4->saddr) 2095 fl4->saddr = FIB_RES_PREFSRC(net, res); 2096 2097 dev_out = FIB_RES_DEV(res); 2098 fl4->flowi4_oif = dev_out->ifindex; 2099 2100 2101 make_route: 2102 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2103 2104 out: 2105 rcu_read_unlock(); 2106 return rth; 2107 } 2108 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2109 2110 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2111 { 2112 return NULL; 2113 } 2114 2115 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2116 { 2117 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2118 2119 return mtu ? : dst->dev->mtu; 2120 } 2121 2122 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2123 struct sk_buff *skb, u32 mtu) 2124 { 2125 } 2126 2127 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2128 struct sk_buff *skb) 2129 { 2130 } 2131 2132 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2133 unsigned long old) 2134 { 2135 return NULL; 2136 } 2137 2138 static struct dst_ops ipv4_dst_blackhole_ops = { 2139 .family = AF_INET, 2140 .protocol = cpu_to_be16(ETH_P_IP), 2141 .check = ipv4_blackhole_dst_check, 2142 .mtu = ipv4_blackhole_mtu, 2143 .default_advmss = ipv4_default_advmss, 2144 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2145 .redirect = ipv4_rt_blackhole_redirect, 2146 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2147 .neigh_lookup = ipv4_neigh_lookup, 2148 }; 2149 2150 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2151 { 2152 struct rtable *ort = (struct rtable *) dst_orig; 2153 struct rtable *rt; 2154 2155 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2156 if (rt) { 2157 struct dst_entry *new = &rt->dst; 2158 2159 new->__use = 1; 2160 new->input = dst_discard; 2161 new->output = dst_discard; 2162 2163 new->dev = ort->dst.dev; 2164 if (new->dev) 2165 dev_hold(new->dev); 2166 2167 rt->rt_is_input = ort->rt_is_input; 2168 rt->rt_iif = ort->rt_iif; 2169 rt->rt_pmtu = ort->rt_pmtu; 2170 2171 rt->rt_genid = rt_genid(net); 2172 rt->rt_flags = ort->rt_flags; 2173 rt->rt_type = ort->rt_type; 2174 rt->rt_gateway = ort->rt_gateway; 2175 rt->rt_uses_gateway = ort->rt_uses_gateway; 2176 2177 INIT_LIST_HEAD(&rt->rt_uncached); 2178 2179 dst_free(new); 2180 } 2181 2182 dst_release(dst_orig); 2183 2184 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2185 } 2186 2187 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2188 struct sock *sk) 2189 { 2190 struct rtable *rt = __ip_route_output_key(net, flp4); 2191 2192 if (IS_ERR(rt)) 2193 return rt; 2194 2195 if (flp4->flowi4_proto) 2196 rt = (struct rtable *) xfrm_lookup(net, &rt->dst, 2197 flowi4_to_flowi(flp4), 2198 sk, 0); 2199 2200 return rt; 2201 } 2202 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2203 2204 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2205 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2206 u32 seq, int event, int nowait, unsigned int flags) 2207 { 2208 struct rtable *rt = skb_rtable(skb); 2209 struct rtmsg *r; 2210 struct nlmsghdr *nlh; 2211 unsigned long expires = 0; 2212 u32 error; 2213 u32 metrics[RTAX_MAX]; 2214 2215 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2216 if (nlh == NULL) 2217 return -EMSGSIZE; 2218 2219 r = nlmsg_data(nlh); 2220 r->rtm_family = AF_INET; 2221 r->rtm_dst_len = 32; 2222 r->rtm_src_len = 0; 2223 r->rtm_tos = fl4->flowi4_tos; 2224 r->rtm_table = RT_TABLE_MAIN; 2225 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) 2226 goto nla_put_failure; 2227 r->rtm_type = rt->rt_type; 2228 r->rtm_scope = RT_SCOPE_UNIVERSE; 2229 r->rtm_protocol = RTPROT_UNSPEC; 2230 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2231 if (rt->rt_flags & RTCF_NOTIFY) 2232 r->rtm_flags |= RTM_F_NOTIFY; 2233 2234 if (nla_put_be32(skb, RTA_DST, dst)) 2235 goto nla_put_failure; 2236 if (src) { 2237 r->rtm_src_len = 32; 2238 if (nla_put_be32(skb, RTA_SRC, src)) 2239 goto nla_put_failure; 2240 } 2241 if (rt->dst.dev && 2242 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2243 goto nla_put_failure; 2244 #ifdef CONFIG_IP_ROUTE_CLASSID 2245 if (rt->dst.tclassid && 2246 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2247 goto nla_put_failure; 2248 #endif 2249 if (!rt_is_input_route(rt) && 2250 fl4->saddr != src) { 2251 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr)) 2252 goto nla_put_failure; 2253 } 2254 if (rt->rt_uses_gateway && 2255 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway)) 2256 goto nla_put_failure; 2257 2258 expires = rt->dst.expires; 2259 if (expires) { 2260 unsigned long now = jiffies; 2261 2262 if (time_before(now, expires)) 2263 expires -= now; 2264 else 2265 expires = 0; 2266 } 2267 2268 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2269 if (rt->rt_pmtu && expires) 2270 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2271 if (rtnetlink_put_metrics(skb, metrics) < 0) 2272 goto nla_put_failure; 2273 2274 if (fl4->flowi4_mark && 2275 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2276 goto nla_put_failure; 2277 2278 error = rt->dst.error; 2279 2280 if (rt_is_input_route(rt)) { 2281 #ifdef CONFIG_IP_MROUTE 2282 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2283 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2284 int err = ipmr_get_route(net, skb, 2285 fl4->saddr, fl4->daddr, 2286 r, nowait); 2287 if (err <= 0) { 2288 if (!nowait) { 2289 if (err == 0) 2290 return 0; 2291 goto nla_put_failure; 2292 } else { 2293 if (err == -EMSGSIZE) 2294 goto nla_put_failure; 2295 error = err; 2296 } 2297 } 2298 } else 2299 #endif 2300 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif)) 2301 goto nla_put_failure; 2302 } 2303 2304 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2305 goto nla_put_failure; 2306 2307 return nlmsg_end(skb, nlh); 2308 2309 nla_put_failure: 2310 nlmsg_cancel(skb, nlh); 2311 return -EMSGSIZE; 2312 } 2313 2314 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg) 2315 { 2316 struct net *net = sock_net(in_skb->sk); 2317 struct rtmsg *rtm; 2318 struct nlattr *tb[RTA_MAX+1]; 2319 struct rtable *rt = NULL; 2320 struct flowi4 fl4; 2321 __be32 dst = 0; 2322 __be32 src = 0; 2323 u32 iif; 2324 int err; 2325 int mark; 2326 struct sk_buff *skb; 2327 2328 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2329 if (err < 0) 2330 goto errout; 2331 2332 rtm = nlmsg_data(nlh); 2333 2334 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2335 if (skb == NULL) { 2336 err = -ENOBUFS; 2337 goto errout; 2338 } 2339 2340 /* Reserve room for dummy headers, this skb can pass 2341 through good chunk of routing engine. 2342 */ 2343 skb_reset_mac_header(skb); 2344 skb_reset_network_header(skb); 2345 2346 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2347 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2348 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2349 2350 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2351 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2352 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2353 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2354 2355 memset(&fl4, 0, sizeof(fl4)); 2356 fl4.daddr = dst; 2357 fl4.saddr = src; 2358 fl4.flowi4_tos = rtm->rtm_tos; 2359 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2360 fl4.flowi4_mark = mark; 2361 2362 if (iif) { 2363 struct net_device *dev; 2364 2365 dev = __dev_get_by_index(net, iif); 2366 if (dev == NULL) { 2367 err = -ENODEV; 2368 goto errout_free; 2369 } 2370 2371 skb->protocol = htons(ETH_P_IP); 2372 skb->dev = dev; 2373 skb->mark = mark; 2374 local_bh_disable(); 2375 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2376 local_bh_enable(); 2377 2378 rt = skb_rtable(skb); 2379 if (err == 0 && rt->dst.error) 2380 err = -rt->dst.error; 2381 } else { 2382 rt = ip_route_output_key(net, &fl4); 2383 2384 err = 0; 2385 if (IS_ERR(rt)) 2386 err = PTR_ERR(rt); 2387 } 2388 2389 if (err) 2390 goto errout_free; 2391 2392 skb_dst_set(skb, &rt->dst); 2393 if (rtm->rtm_flags & RTM_F_NOTIFY) 2394 rt->rt_flags |= RTCF_NOTIFY; 2395 2396 err = rt_fill_info(net, dst, src, &fl4, skb, 2397 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2398 RTM_NEWROUTE, 0, 0); 2399 if (err <= 0) 2400 goto errout_free; 2401 2402 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2403 errout: 2404 return err; 2405 2406 errout_free: 2407 kfree_skb(skb); 2408 goto errout; 2409 } 2410 2411 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) 2412 { 2413 return skb->len; 2414 } 2415 2416 void ip_rt_multicast_event(struct in_device *in_dev) 2417 { 2418 rt_cache_flush(dev_net(in_dev->dev)); 2419 } 2420 2421 #ifdef CONFIG_SYSCTL 2422 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2423 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2424 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2425 static int ip_rt_gc_elasticity __read_mostly = 8; 2426 2427 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, 2428 void __user *buffer, 2429 size_t *lenp, loff_t *ppos) 2430 { 2431 if (write) { 2432 rt_cache_flush((struct net *)__ctl->extra1); 2433 return 0; 2434 } 2435 2436 return -EINVAL; 2437 } 2438 2439 static ctl_table ipv4_route_table[] = { 2440 { 2441 .procname = "gc_thresh", 2442 .data = &ipv4_dst_ops.gc_thresh, 2443 .maxlen = sizeof(int), 2444 .mode = 0644, 2445 .proc_handler = proc_dointvec, 2446 }, 2447 { 2448 .procname = "max_size", 2449 .data = &ip_rt_max_size, 2450 .maxlen = sizeof(int), 2451 .mode = 0644, 2452 .proc_handler = proc_dointvec, 2453 }, 2454 { 2455 /* Deprecated. Use gc_min_interval_ms */ 2456 2457 .procname = "gc_min_interval", 2458 .data = &ip_rt_gc_min_interval, 2459 .maxlen = sizeof(int), 2460 .mode = 0644, 2461 .proc_handler = proc_dointvec_jiffies, 2462 }, 2463 { 2464 .procname = "gc_min_interval_ms", 2465 .data = &ip_rt_gc_min_interval, 2466 .maxlen = sizeof(int), 2467 .mode = 0644, 2468 .proc_handler = proc_dointvec_ms_jiffies, 2469 }, 2470 { 2471 .procname = "gc_timeout", 2472 .data = &ip_rt_gc_timeout, 2473 .maxlen = sizeof(int), 2474 .mode = 0644, 2475 .proc_handler = proc_dointvec_jiffies, 2476 }, 2477 { 2478 .procname = "gc_interval", 2479 .data = &ip_rt_gc_interval, 2480 .maxlen = sizeof(int), 2481 .mode = 0644, 2482 .proc_handler = proc_dointvec_jiffies, 2483 }, 2484 { 2485 .procname = "redirect_load", 2486 .data = &ip_rt_redirect_load, 2487 .maxlen = sizeof(int), 2488 .mode = 0644, 2489 .proc_handler = proc_dointvec, 2490 }, 2491 { 2492 .procname = "redirect_number", 2493 .data = &ip_rt_redirect_number, 2494 .maxlen = sizeof(int), 2495 .mode = 0644, 2496 .proc_handler = proc_dointvec, 2497 }, 2498 { 2499 .procname = "redirect_silence", 2500 .data = &ip_rt_redirect_silence, 2501 .maxlen = sizeof(int), 2502 .mode = 0644, 2503 .proc_handler = proc_dointvec, 2504 }, 2505 { 2506 .procname = "error_cost", 2507 .data = &ip_rt_error_cost, 2508 .maxlen = sizeof(int), 2509 .mode = 0644, 2510 .proc_handler = proc_dointvec, 2511 }, 2512 { 2513 .procname = "error_burst", 2514 .data = &ip_rt_error_burst, 2515 .maxlen = sizeof(int), 2516 .mode = 0644, 2517 .proc_handler = proc_dointvec, 2518 }, 2519 { 2520 .procname = "gc_elasticity", 2521 .data = &ip_rt_gc_elasticity, 2522 .maxlen = sizeof(int), 2523 .mode = 0644, 2524 .proc_handler = proc_dointvec, 2525 }, 2526 { 2527 .procname = "mtu_expires", 2528 .data = &ip_rt_mtu_expires, 2529 .maxlen = sizeof(int), 2530 .mode = 0644, 2531 .proc_handler = proc_dointvec_jiffies, 2532 }, 2533 { 2534 .procname = "min_pmtu", 2535 .data = &ip_rt_min_pmtu, 2536 .maxlen = sizeof(int), 2537 .mode = 0644, 2538 .proc_handler = proc_dointvec, 2539 }, 2540 { 2541 .procname = "min_adv_mss", 2542 .data = &ip_rt_min_advmss, 2543 .maxlen = sizeof(int), 2544 .mode = 0644, 2545 .proc_handler = proc_dointvec, 2546 }, 2547 { } 2548 }; 2549 2550 static struct ctl_table ipv4_route_flush_table[] = { 2551 { 2552 .procname = "flush", 2553 .maxlen = sizeof(int), 2554 .mode = 0200, 2555 .proc_handler = ipv4_sysctl_rtcache_flush, 2556 }, 2557 { }, 2558 }; 2559 2560 static __net_init int sysctl_route_net_init(struct net *net) 2561 { 2562 struct ctl_table *tbl; 2563 2564 tbl = ipv4_route_flush_table; 2565 if (!net_eq(net, &init_net)) { 2566 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2567 if (tbl == NULL) 2568 goto err_dup; 2569 2570 /* Don't export sysctls to unprivileged users */ 2571 if (net->user_ns != &init_user_ns) 2572 tbl[0].procname = NULL; 2573 } 2574 tbl[0].extra1 = net; 2575 2576 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2577 if (net->ipv4.route_hdr == NULL) 2578 goto err_reg; 2579 return 0; 2580 2581 err_reg: 2582 if (tbl != ipv4_route_flush_table) 2583 kfree(tbl); 2584 err_dup: 2585 return -ENOMEM; 2586 } 2587 2588 static __net_exit void sysctl_route_net_exit(struct net *net) 2589 { 2590 struct ctl_table *tbl; 2591 2592 tbl = net->ipv4.route_hdr->ctl_table_arg; 2593 unregister_net_sysctl_table(net->ipv4.route_hdr); 2594 BUG_ON(tbl == ipv4_route_flush_table); 2595 kfree(tbl); 2596 } 2597 2598 static __net_initdata struct pernet_operations sysctl_route_ops = { 2599 .init = sysctl_route_net_init, 2600 .exit = sysctl_route_net_exit, 2601 }; 2602 #endif 2603 2604 static __net_init int rt_genid_init(struct net *net) 2605 { 2606 atomic_set(&net->rt_genid, 0); 2607 get_random_bytes(&net->ipv4.dev_addr_genid, 2608 sizeof(net->ipv4.dev_addr_genid)); 2609 return 0; 2610 } 2611 2612 static __net_initdata struct pernet_operations rt_genid_ops = { 2613 .init = rt_genid_init, 2614 }; 2615 2616 static int __net_init ipv4_inetpeer_init(struct net *net) 2617 { 2618 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2619 2620 if (!bp) 2621 return -ENOMEM; 2622 inet_peer_base_init(bp); 2623 net->ipv4.peers = bp; 2624 return 0; 2625 } 2626 2627 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2628 { 2629 struct inet_peer_base *bp = net->ipv4.peers; 2630 2631 net->ipv4.peers = NULL; 2632 inetpeer_invalidate_tree(bp); 2633 kfree(bp); 2634 } 2635 2636 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2637 .init = ipv4_inetpeer_init, 2638 .exit = ipv4_inetpeer_exit, 2639 }; 2640 2641 #ifdef CONFIG_IP_ROUTE_CLASSID 2642 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2643 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2644 2645 int __init ip_rt_init(void) 2646 { 2647 int rc = 0; 2648 2649 #ifdef CONFIG_IP_ROUTE_CLASSID 2650 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2651 if (!ip_rt_acct) 2652 panic("IP: failed to allocate ip_rt_acct\n"); 2653 #endif 2654 2655 ipv4_dst_ops.kmem_cachep = 2656 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2657 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2658 2659 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2660 2661 if (dst_entries_init(&ipv4_dst_ops) < 0) 2662 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2663 2664 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2665 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2666 2667 ipv4_dst_ops.gc_thresh = ~0; 2668 ip_rt_max_size = INT_MAX; 2669 2670 devinet_init(); 2671 ip_fib_init(); 2672 2673 if (ip_rt_proc_init()) 2674 pr_err("Unable to create route proc files\n"); 2675 #ifdef CONFIG_XFRM 2676 xfrm_init(); 2677 xfrm4_init(); 2678 #endif 2679 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2680 2681 #ifdef CONFIG_SYSCTL 2682 register_pernet_subsys(&sysctl_route_ops); 2683 #endif 2684 register_pernet_subsys(&rt_genid_ops); 2685 register_pernet_subsys(&ipv4_inetpeer_ops); 2686 return rc; 2687 } 2688 2689 #ifdef CONFIG_SYSCTL 2690 /* 2691 * We really need to sanitize the damn ipv4 init order, then all 2692 * this nonsense will go away. 2693 */ 2694 void __init ip_static_sysctl_init(void) 2695 { 2696 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2697 } 2698 #endif 2699