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/dst_metadata.h> 95 #include <net/net_namespace.h> 96 #include <net/protocol.h> 97 #include <net/ip.h> 98 #include <net/route.h> 99 #include <net/inetpeer.h> 100 #include <net/sock.h> 101 #include <net/ip_fib.h> 102 #include <net/arp.h> 103 #include <net/tcp.h> 104 #include <net/icmp.h> 105 #include <net/xfrm.h> 106 #include <net/lwtunnel.h> 107 #include <net/netevent.h> 108 #include <net/rtnetlink.h> 109 #ifdef CONFIG_SYSCTL 110 #include <linux/sysctl.h> 111 #include <linux/kmemleak.h> 112 #endif 113 #include <net/secure_seq.h> 114 #include <net/ip_tunnels.h> 115 #include <net/vrf.h> 116 117 #define RT_FL_TOS(oldflp4) \ 118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 119 120 #define RT_GC_TIMEOUT (300*HZ) 121 122 static int ip_rt_max_size; 123 static int ip_rt_redirect_number __read_mostly = 9; 124 static int ip_rt_redirect_load __read_mostly = HZ / 50; 125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 126 static int ip_rt_error_cost __read_mostly = HZ; 127 static int ip_rt_error_burst __read_mostly = 5 * HZ; 128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 130 static int ip_rt_min_advmss __read_mostly = 256; 131 132 /* 133 * Interface to generic destination cache. 134 */ 135 136 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 137 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 138 static unsigned int ipv4_mtu(const struct dst_entry *dst); 139 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 140 static void ipv4_link_failure(struct sk_buff *skb); 141 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 142 struct sk_buff *skb, u32 mtu); 143 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 144 struct sk_buff *skb); 145 static void ipv4_dst_destroy(struct dst_entry *dst); 146 147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 148 { 149 WARN_ON(1); 150 return NULL; 151 } 152 153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 154 struct sk_buff *skb, 155 const void *daddr); 156 157 static struct dst_ops ipv4_dst_ops = { 158 .family = AF_INET, 159 .check = ipv4_dst_check, 160 .default_advmss = ipv4_default_advmss, 161 .mtu = ipv4_mtu, 162 .cow_metrics = ipv4_cow_metrics, 163 .destroy = ipv4_dst_destroy, 164 .negative_advice = ipv4_negative_advice, 165 .link_failure = ipv4_link_failure, 166 .update_pmtu = ip_rt_update_pmtu, 167 .redirect = ip_do_redirect, 168 .local_out = __ip_local_out, 169 .neigh_lookup = ipv4_neigh_lookup, 170 }; 171 172 #define ECN_OR_COST(class) TC_PRIO_##class 173 174 const __u8 ip_tos2prio[16] = { 175 TC_PRIO_BESTEFFORT, 176 ECN_OR_COST(BESTEFFORT), 177 TC_PRIO_BESTEFFORT, 178 ECN_OR_COST(BESTEFFORT), 179 TC_PRIO_BULK, 180 ECN_OR_COST(BULK), 181 TC_PRIO_BULK, 182 ECN_OR_COST(BULK), 183 TC_PRIO_INTERACTIVE, 184 ECN_OR_COST(INTERACTIVE), 185 TC_PRIO_INTERACTIVE, 186 ECN_OR_COST(INTERACTIVE), 187 TC_PRIO_INTERACTIVE_BULK, 188 ECN_OR_COST(INTERACTIVE_BULK), 189 TC_PRIO_INTERACTIVE_BULK, 190 ECN_OR_COST(INTERACTIVE_BULK) 191 }; 192 EXPORT_SYMBOL(ip_tos2prio); 193 194 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 195 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 196 197 #ifdef CONFIG_PROC_FS 198 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 199 { 200 if (*pos) 201 return NULL; 202 return SEQ_START_TOKEN; 203 } 204 205 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 206 { 207 ++*pos; 208 return NULL; 209 } 210 211 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 212 { 213 } 214 215 static int rt_cache_seq_show(struct seq_file *seq, void *v) 216 { 217 if (v == SEQ_START_TOKEN) 218 seq_printf(seq, "%-127s\n", 219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 221 "HHUptod\tSpecDst"); 222 return 0; 223 } 224 225 static const struct seq_operations rt_cache_seq_ops = { 226 .start = rt_cache_seq_start, 227 .next = rt_cache_seq_next, 228 .stop = rt_cache_seq_stop, 229 .show = rt_cache_seq_show, 230 }; 231 232 static int rt_cache_seq_open(struct inode *inode, struct file *file) 233 { 234 return seq_open(file, &rt_cache_seq_ops); 235 } 236 237 static const struct file_operations rt_cache_seq_fops = { 238 .owner = THIS_MODULE, 239 .open = rt_cache_seq_open, 240 .read = seq_read, 241 .llseek = seq_lseek, 242 .release = seq_release, 243 }; 244 245 246 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 247 { 248 int cpu; 249 250 if (*pos == 0) 251 return SEQ_START_TOKEN; 252 253 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 254 if (!cpu_possible(cpu)) 255 continue; 256 *pos = cpu+1; 257 return &per_cpu(rt_cache_stat, cpu); 258 } 259 return NULL; 260 } 261 262 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 263 { 264 int cpu; 265 266 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 267 if (!cpu_possible(cpu)) 268 continue; 269 *pos = cpu+1; 270 return &per_cpu(rt_cache_stat, cpu); 271 } 272 return NULL; 273 274 } 275 276 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 277 { 278 279 } 280 281 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 282 { 283 struct rt_cache_stat *st = v; 284 285 if (v == SEQ_START_TOKEN) { 286 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"); 287 return 0; 288 } 289 290 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 291 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 292 dst_entries_get_slow(&ipv4_dst_ops), 293 0, /* st->in_hit */ 294 st->in_slow_tot, 295 st->in_slow_mc, 296 st->in_no_route, 297 st->in_brd, 298 st->in_martian_dst, 299 st->in_martian_src, 300 301 0, /* st->out_hit */ 302 st->out_slow_tot, 303 st->out_slow_mc, 304 305 0, /* st->gc_total */ 306 0, /* st->gc_ignored */ 307 0, /* st->gc_goal_miss */ 308 0, /* st->gc_dst_overflow */ 309 0, /* st->in_hlist_search */ 310 0 /* st->out_hlist_search */ 311 ); 312 return 0; 313 } 314 315 static const struct seq_operations rt_cpu_seq_ops = { 316 .start = rt_cpu_seq_start, 317 .next = rt_cpu_seq_next, 318 .stop = rt_cpu_seq_stop, 319 .show = rt_cpu_seq_show, 320 }; 321 322 323 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 324 { 325 return seq_open(file, &rt_cpu_seq_ops); 326 } 327 328 static const struct file_operations rt_cpu_seq_fops = { 329 .owner = THIS_MODULE, 330 .open = rt_cpu_seq_open, 331 .read = seq_read, 332 .llseek = seq_lseek, 333 .release = seq_release, 334 }; 335 336 #ifdef CONFIG_IP_ROUTE_CLASSID 337 static int rt_acct_proc_show(struct seq_file *m, void *v) 338 { 339 struct ip_rt_acct *dst, *src; 340 unsigned int i, j; 341 342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 343 if (!dst) 344 return -ENOMEM; 345 346 for_each_possible_cpu(i) { 347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 348 for (j = 0; j < 256; j++) { 349 dst[j].o_bytes += src[j].o_bytes; 350 dst[j].o_packets += src[j].o_packets; 351 dst[j].i_bytes += src[j].i_bytes; 352 dst[j].i_packets += src[j].i_packets; 353 } 354 } 355 356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 357 kfree(dst); 358 return 0; 359 } 360 361 static int rt_acct_proc_open(struct inode *inode, struct file *file) 362 { 363 return single_open(file, rt_acct_proc_show, NULL); 364 } 365 366 static const struct file_operations rt_acct_proc_fops = { 367 .owner = THIS_MODULE, 368 .open = rt_acct_proc_open, 369 .read = seq_read, 370 .llseek = seq_lseek, 371 .release = single_release, 372 }; 373 #endif 374 375 static int __net_init ip_rt_do_proc_init(struct net *net) 376 { 377 struct proc_dir_entry *pde; 378 379 pde = proc_create("rt_cache", S_IRUGO, net->proc_net, 380 &rt_cache_seq_fops); 381 if (!pde) 382 goto err1; 383 384 pde = proc_create("rt_cache", S_IRUGO, 385 net->proc_net_stat, &rt_cpu_seq_fops); 386 if (!pde) 387 goto err2; 388 389 #ifdef CONFIG_IP_ROUTE_CLASSID 390 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 391 if (!pde) 392 goto err3; 393 #endif 394 return 0; 395 396 #ifdef CONFIG_IP_ROUTE_CLASSID 397 err3: 398 remove_proc_entry("rt_cache", net->proc_net_stat); 399 #endif 400 err2: 401 remove_proc_entry("rt_cache", net->proc_net); 402 err1: 403 return -ENOMEM; 404 } 405 406 static void __net_exit ip_rt_do_proc_exit(struct net *net) 407 { 408 remove_proc_entry("rt_cache", net->proc_net_stat); 409 remove_proc_entry("rt_cache", net->proc_net); 410 #ifdef CONFIG_IP_ROUTE_CLASSID 411 remove_proc_entry("rt_acct", net->proc_net); 412 #endif 413 } 414 415 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 416 .init = ip_rt_do_proc_init, 417 .exit = ip_rt_do_proc_exit, 418 }; 419 420 static int __init ip_rt_proc_init(void) 421 { 422 return register_pernet_subsys(&ip_rt_proc_ops); 423 } 424 425 #else 426 static inline int ip_rt_proc_init(void) 427 { 428 return 0; 429 } 430 #endif /* CONFIG_PROC_FS */ 431 432 static inline bool rt_is_expired(const struct rtable *rth) 433 { 434 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 435 } 436 437 void rt_cache_flush(struct net *net) 438 { 439 rt_genid_bump_ipv4(net); 440 } 441 442 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 443 struct sk_buff *skb, 444 const void *daddr) 445 { 446 struct net_device *dev = dst->dev; 447 const __be32 *pkey = daddr; 448 const struct rtable *rt; 449 struct neighbour *n; 450 451 rt = (const struct rtable *) dst; 452 if (rt->rt_gateway) 453 pkey = (const __be32 *) &rt->rt_gateway; 454 else if (skb) 455 pkey = &ip_hdr(skb)->daddr; 456 457 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 458 if (n) 459 return n; 460 return neigh_create(&arp_tbl, pkey, dev); 461 } 462 463 #define IP_IDENTS_SZ 2048u 464 465 static atomic_t *ip_idents __read_mostly; 466 static u32 *ip_tstamps __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 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; 475 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; 476 u32 old = ACCESS_ONCE(*p_tstamp); 477 u32 now = (u32)jiffies; 478 u32 delta = 0; 479 480 if (old != now && cmpxchg(p_tstamp, old, now) == old) 481 delta = prandom_u32_max(now - old); 482 483 return atomic_add_return(segs + delta, p_id) - segs; 484 } 485 EXPORT_SYMBOL(ip_idents_reserve); 486 487 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 488 { 489 static u32 ip_idents_hashrnd __read_mostly; 490 u32 hash, id; 491 492 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); 493 494 hash = jhash_3words((__force u32)iph->daddr, 495 (__force u32)iph->saddr, 496 iph->protocol ^ net_hash_mix(net), 497 ip_idents_hashrnd); 498 id = ip_idents_reserve(hash, segs); 499 iph->id = htons(id); 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 void fnhe_flush_routes(struct fib_nh_exception *fnhe) 569 { 570 struct rtable *rt; 571 572 rt = rcu_dereference(fnhe->fnhe_rth_input); 573 if (rt) { 574 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 575 rt_free(rt); 576 } 577 rt = rcu_dereference(fnhe->fnhe_rth_output); 578 if (rt) { 579 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 580 rt_free(rt); 581 } 582 } 583 584 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 585 { 586 struct fib_nh_exception *fnhe, *oldest; 587 588 oldest = rcu_dereference(hash->chain); 589 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 590 fnhe = rcu_dereference(fnhe->fnhe_next)) { 591 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 592 oldest = fnhe; 593 } 594 fnhe_flush_routes(oldest); 595 return oldest; 596 } 597 598 static inline u32 fnhe_hashfun(__be32 daddr) 599 { 600 static u32 fnhe_hashrnd __read_mostly; 601 u32 hval; 602 603 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 604 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 605 return hash_32(hval, FNHE_HASH_SHIFT); 606 } 607 608 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 609 { 610 rt->rt_pmtu = fnhe->fnhe_pmtu; 611 rt->dst.expires = fnhe->fnhe_expires; 612 613 if (fnhe->fnhe_gw) { 614 rt->rt_flags |= RTCF_REDIRECTED; 615 rt->rt_gateway = fnhe->fnhe_gw; 616 rt->rt_uses_gateway = 1; 617 } 618 } 619 620 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 621 u32 pmtu, unsigned long expires) 622 { 623 struct fnhe_hash_bucket *hash; 624 struct fib_nh_exception *fnhe; 625 struct rtable *rt; 626 unsigned int i; 627 int depth; 628 u32 hval = fnhe_hashfun(daddr); 629 630 spin_lock_bh(&fnhe_lock); 631 632 hash = rcu_dereference(nh->nh_exceptions); 633 if (!hash) { 634 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC); 635 if (!hash) 636 goto out_unlock; 637 rcu_assign_pointer(nh->nh_exceptions, hash); 638 } 639 640 hash += hval; 641 642 depth = 0; 643 for (fnhe = rcu_dereference(hash->chain); fnhe; 644 fnhe = rcu_dereference(fnhe->fnhe_next)) { 645 if (fnhe->fnhe_daddr == daddr) 646 break; 647 depth++; 648 } 649 650 if (fnhe) { 651 if (gw) 652 fnhe->fnhe_gw = gw; 653 if (pmtu) { 654 fnhe->fnhe_pmtu = pmtu; 655 fnhe->fnhe_expires = max(1UL, expires); 656 } 657 /* Update all cached dsts too */ 658 rt = rcu_dereference(fnhe->fnhe_rth_input); 659 if (rt) 660 fill_route_from_fnhe(rt, fnhe); 661 rt = rcu_dereference(fnhe->fnhe_rth_output); 662 if (rt) 663 fill_route_from_fnhe(rt, fnhe); 664 } else { 665 if (depth > FNHE_RECLAIM_DEPTH) 666 fnhe = fnhe_oldest(hash); 667 else { 668 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 669 if (!fnhe) 670 goto out_unlock; 671 672 fnhe->fnhe_next = hash->chain; 673 rcu_assign_pointer(hash->chain, fnhe); 674 } 675 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev)); 676 fnhe->fnhe_daddr = daddr; 677 fnhe->fnhe_gw = gw; 678 fnhe->fnhe_pmtu = pmtu; 679 fnhe->fnhe_expires = expires; 680 681 /* Exception created; mark the cached routes for the nexthop 682 * stale, so anyone caching it rechecks if this exception 683 * applies to them. 684 */ 685 rt = rcu_dereference(nh->nh_rth_input); 686 if (rt) 687 rt->dst.obsolete = DST_OBSOLETE_KILL; 688 689 for_each_possible_cpu(i) { 690 struct rtable __rcu **prt; 691 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 692 rt = rcu_dereference(*prt); 693 if (rt) 694 rt->dst.obsolete = DST_OBSOLETE_KILL; 695 } 696 } 697 698 fnhe->fnhe_stamp = jiffies; 699 700 out_unlock: 701 spin_unlock_bh(&fnhe_lock); 702 } 703 704 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 705 bool kill_route) 706 { 707 __be32 new_gw = icmp_hdr(skb)->un.gateway; 708 __be32 old_gw = ip_hdr(skb)->saddr; 709 struct net_device *dev = skb->dev; 710 struct in_device *in_dev; 711 struct fib_result res; 712 struct neighbour *n; 713 struct net *net; 714 715 switch (icmp_hdr(skb)->code & 7) { 716 case ICMP_REDIR_NET: 717 case ICMP_REDIR_NETTOS: 718 case ICMP_REDIR_HOST: 719 case ICMP_REDIR_HOSTTOS: 720 break; 721 722 default: 723 return; 724 } 725 726 if (rt->rt_gateway != old_gw) 727 return; 728 729 in_dev = __in_dev_get_rcu(dev); 730 if (!in_dev) 731 return; 732 733 net = dev_net(dev); 734 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 735 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 736 ipv4_is_zeronet(new_gw)) 737 goto reject_redirect; 738 739 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 740 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 741 goto reject_redirect; 742 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 743 goto reject_redirect; 744 } else { 745 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 746 goto reject_redirect; 747 } 748 749 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw); 750 if (!IS_ERR(n)) { 751 if (!(n->nud_state & NUD_VALID)) { 752 neigh_event_send(n, NULL); 753 } else { 754 if (fib_lookup(net, fl4, &res, 0) == 0) { 755 struct fib_nh *nh = &FIB_RES_NH(res); 756 757 update_or_create_fnhe(nh, fl4->daddr, new_gw, 758 0, 0); 759 } 760 if (kill_route) 761 rt->dst.obsolete = DST_OBSOLETE_KILL; 762 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 763 } 764 neigh_release(n); 765 } 766 return; 767 768 reject_redirect: 769 #ifdef CONFIG_IP_ROUTE_VERBOSE 770 if (IN_DEV_LOG_MARTIANS(in_dev)) { 771 const struct iphdr *iph = (const struct iphdr *) skb->data; 772 __be32 daddr = iph->daddr; 773 __be32 saddr = iph->saddr; 774 775 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 776 " Advised path = %pI4 -> %pI4\n", 777 &old_gw, dev->name, &new_gw, 778 &saddr, &daddr); 779 } 780 #endif 781 ; 782 } 783 784 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 785 { 786 struct rtable *rt; 787 struct flowi4 fl4; 788 const struct iphdr *iph = (const struct iphdr *) skb->data; 789 int oif = skb->dev->ifindex; 790 u8 tos = RT_TOS(iph->tos); 791 u8 prot = iph->protocol; 792 u32 mark = skb->mark; 793 794 rt = (struct rtable *) dst; 795 796 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0); 797 __ip_do_redirect(rt, skb, &fl4, true); 798 } 799 800 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 801 { 802 struct rtable *rt = (struct rtable *)dst; 803 struct dst_entry *ret = dst; 804 805 if (rt) { 806 if (dst->obsolete > 0) { 807 ip_rt_put(rt); 808 ret = NULL; 809 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 810 rt->dst.expires) { 811 ip_rt_put(rt); 812 ret = NULL; 813 } 814 } 815 return ret; 816 } 817 818 /* 819 * Algorithm: 820 * 1. The first ip_rt_redirect_number redirects are sent 821 * with exponential backoff, then we stop sending them at all, 822 * assuming that the host ignores our redirects. 823 * 2. If we did not see packets requiring redirects 824 * during ip_rt_redirect_silence, we assume that the host 825 * forgot redirected route and start to send redirects again. 826 * 827 * This algorithm is much cheaper and more intelligent than dumb load limiting 828 * in icmp.c. 829 * 830 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 831 * and "frag. need" (breaks PMTU discovery) in icmp.c. 832 */ 833 834 void ip_rt_send_redirect(struct sk_buff *skb) 835 { 836 struct rtable *rt = skb_rtable(skb); 837 struct in_device *in_dev; 838 struct inet_peer *peer; 839 struct net *net; 840 int log_martians; 841 int vif; 842 843 rcu_read_lock(); 844 in_dev = __in_dev_get_rcu(rt->dst.dev); 845 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 846 rcu_read_unlock(); 847 return; 848 } 849 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 850 vif = vrf_master_ifindex_rcu(rt->dst.dev); 851 rcu_read_unlock(); 852 853 net = dev_net(rt->dst.dev); 854 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 855 if (!peer) { 856 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 857 rt_nexthop(rt, ip_hdr(skb)->daddr)); 858 return; 859 } 860 861 /* No redirected packets during ip_rt_redirect_silence; 862 * reset the algorithm. 863 */ 864 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 865 peer->rate_tokens = 0; 866 867 /* Too many ignored redirects; do not send anything 868 * set dst.rate_last to the last seen redirected packet. 869 */ 870 if (peer->rate_tokens >= ip_rt_redirect_number) { 871 peer->rate_last = jiffies; 872 goto out_put_peer; 873 } 874 875 /* Check for load limit; set rate_last to the latest sent 876 * redirect. 877 */ 878 if (peer->rate_tokens == 0 || 879 time_after(jiffies, 880 (peer->rate_last + 881 (ip_rt_redirect_load << peer->rate_tokens)))) { 882 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 883 884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 885 peer->rate_last = jiffies; 886 ++peer->rate_tokens; 887 #ifdef CONFIG_IP_ROUTE_VERBOSE 888 if (log_martians && 889 peer->rate_tokens == ip_rt_redirect_number) 890 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 891 &ip_hdr(skb)->saddr, inet_iif(skb), 892 &ip_hdr(skb)->daddr, &gw); 893 #endif 894 } 895 out_put_peer: 896 inet_putpeer(peer); 897 } 898 899 static int ip_error(struct sk_buff *skb) 900 { 901 struct in_device *in_dev = __in_dev_get_rcu(skb->dev); 902 struct rtable *rt = skb_rtable(skb); 903 struct inet_peer *peer; 904 unsigned long now; 905 struct net *net; 906 bool send; 907 int code; 908 909 /* IP on this device is disabled. */ 910 if (!in_dev) 911 goto out; 912 913 net = dev_net(rt->dst.dev); 914 if (!IN_DEV_FORWARD(in_dev)) { 915 switch (rt->dst.error) { 916 case EHOSTUNREACH: 917 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS); 918 break; 919 920 case ENETUNREACH: 921 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 922 break; 923 } 924 goto out; 925 } 926 927 switch (rt->dst.error) { 928 case EINVAL: 929 default: 930 goto out; 931 case EHOSTUNREACH: 932 code = ICMP_HOST_UNREACH; 933 break; 934 case ENETUNREACH: 935 code = ICMP_NET_UNREACH; 936 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES); 937 break; 938 case EACCES: 939 code = ICMP_PKT_FILTERED; 940 break; 941 } 942 943 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 944 vrf_master_ifindex(skb->dev), 1); 945 946 send = true; 947 if (peer) { 948 now = jiffies; 949 peer->rate_tokens += now - peer->rate_last; 950 if (peer->rate_tokens > ip_rt_error_burst) 951 peer->rate_tokens = ip_rt_error_burst; 952 peer->rate_last = now; 953 if (peer->rate_tokens >= ip_rt_error_cost) 954 peer->rate_tokens -= ip_rt_error_cost; 955 else 956 send = false; 957 inet_putpeer(peer); 958 } 959 if (send) 960 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 961 962 out: kfree_skb(skb); 963 return 0; 964 } 965 966 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 967 { 968 struct dst_entry *dst = &rt->dst; 969 struct fib_result res; 970 971 if (dst_metric_locked(dst, RTAX_MTU)) 972 return; 973 974 if (ipv4_mtu(dst) < mtu) 975 return; 976 977 if (mtu < ip_rt_min_pmtu) 978 mtu = ip_rt_min_pmtu; 979 980 if (rt->rt_pmtu == mtu && 981 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 982 return; 983 984 rcu_read_lock(); 985 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) { 986 struct fib_nh *nh = &FIB_RES_NH(res); 987 988 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, 989 jiffies + ip_rt_mtu_expires); 990 } 991 rcu_read_unlock(); 992 } 993 994 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 995 struct sk_buff *skb, u32 mtu) 996 { 997 struct rtable *rt = (struct rtable *) dst; 998 struct flowi4 fl4; 999 1000 ip_rt_build_flow_key(&fl4, sk, skb); 1001 __ip_rt_update_pmtu(rt, &fl4, mtu); 1002 } 1003 1004 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1005 int oif, u32 mark, u8 protocol, int flow_flags) 1006 { 1007 const struct iphdr *iph = (const struct iphdr *) skb->data; 1008 struct flowi4 fl4; 1009 struct rtable *rt; 1010 1011 if (!mark) 1012 mark = IP4_REPLY_MARK(net, skb->mark); 1013 1014 __build_flow_key(&fl4, NULL, iph, oif, 1015 RT_TOS(iph->tos), protocol, mark, flow_flags); 1016 rt = __ip_route_output_key(net, &fl4); 1017 if (!IS_ERR(rt)) { 1018 __ip_rt_update_pmtu(rt, &fl4, mtu); 1019 ip_rt_put(rt); 1020 } 1021 } 1022 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1023 1024 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1025 { 1026 const struct iphdr *iph = (const struct iphdr *) skb->data; 1027 struct flowi4 fl4; 1028 struct rtable *rt; 1029 1030 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1031 1032 if (!fl4.flowi4_mark) 1033 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1034 1035 rt = __ip_route_output_key(sock_net(sk), &fl4); 1036 if (!IS_ERR(rt)) { 1037 __ip_rt_update_pmtu(rt, &fl4, mtu); 1038 ip_rt_put(rt); 1039 } 1040 } 1041 1042 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1043 { 1044 const struct iphdr *iph = (const struct iphdr *) skb->data; 1045 struct flowi4 fl4; 1046 struct rtable *rt; 1047 struct dst_entry *odst = NULL; 1048 bool new = false; 1049 1050 bh_lock_sock(sk); 1051 1052 if (!ip_sk_accept_pmtu(sk)) 1053 goto out; 1054 1055 odst = sk_dst_get(sk); 1056 1057 if (sock_owned_by_user(sk) || !odst) { 1058 __ipv4_sk_update_pmtu(skb, sk, mtu); 1059 goto out; 1060 } 1061 1062 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1063 1064 rt = (struct rtable *)odst; 1065 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1066 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1067 if (IS_ERR(rt)) 1068 goto out; 1069 1070 new = true; 1071 } 1072 1073 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); 1074 1075 if (!dst_check(&rt->dst, 0)) { 1076 if (new) 1077 dst_release(&rt->dst); 1078 1079 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1080 if (IS_ERR(rt)) 1081 goto out; 1082 1083 new = true; 1084 } 1085 1086 if (new) 1087 sk_dst_set(sk, &rt->dst); 1088 1089 out: 1090 bh_unlock_sock(sk); 1091 dst_release(odst); 1092 } 1093 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1094 1095 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1096 int oif, u32 mark, u8 protocol, int flow_flags) 1097 { 1098 const struct iphdr *iph = (const struct iphdr *) skb->data; 1099 struct flowi4 fl4; 1100 struct rtable *rt; 1101 1102 __build_flow_key(&fl4, NULL, iph, oif, 1103 RT_TOS(iph->tos), protocol, mark, flow_flags); 1104 rt = __ip_route_output_key(net, &fl4); 1105 if (!IS_ERR(rt)) { 1106 __ip_do_redirect(rt, skb, &fl4, false); 1107 ip_rt_put(rt); 1108 } 1109 } 1110 EXPORT_SYMBOL_GPL(ipv4_redirect); 1111 1112 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1113 { 1114 const struct iphdr *iph = (const struct iphdr *) skb->data; 1115 struct flowi4 fl4; 1116 struct rtable *rt; 1117 1118 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); 1119 rt = __ip_route_output_key(sock_net(sk), &fl4); 1120 if (!IS_ERR(rt)) { 1121 __ip_do_redirect(rt, skb, &fl4, false); 1122 ip_rt_put(rt); 1123 } 1124 } 1125 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1126 1127 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1128 { 1129 struct rtable *rt = (struct rtable *) dst; 1130 1131 /* All IPV4 dsts are created with ->obsolete set to the value 1132 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1133 * into this function always. 1134 * 1135 * When a PMTU/redirect information update invalidates a route, 1136 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1137 * DST_OBSOLETE_DEAD by dst_free(). 1138 */ 1139 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1140 return NULL; 1141 return dst; 1142 } 1143 1144 static void ipv4_link_failure(struct sk_buff *skb) 1145 { 1146 struct rtable *rt; 1147 1148 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1149 1150 rt = skb_rtable(skb); 1151 if (rt) 1152 dst_set_expires(&rt->dst, 0); 1153 } 1154 1155 static int ip_rt_bug(struct sock *sk, struct sk_buff *skb) 1156 { 1157 pr_debug("%s: %pI4 -> %pI4, %s\n", 1158 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1159 skb->dev ? skb->dev->name : "?"); 1160 kfree_skb(skb); 1161 WARN_ON(1); 1162 return 0; 1163 } 1164 1165 /* 1166 We do not cache source address of outgoing interface, 1167 because it is used only by IP RR, TS and SRR options, 1168 so that it out of fast path. 1169 1170 BTW remember: "addr" is allowed to be not aligned 1171 in IP options! 1172 */ 1173 1174 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1175 { 1176 __be32 src; 1177 1178 if (rt_is_output_route(rt)) 1179 src = ip_hdr(skb)->saddr; 1180 else { 1181 struct fib_result res; 1182 struct flowi4 fl4; 1183 struct iphdr *iph; 1184 1185 iph = ip_hdr(skb); 1186 1187 memset(&fl4, 0, sizeof(fl4)); 1188 fl4.daddr = iph->daddr; 1189 fl4.saddr = iph->saddr; 1190 fl4.flowi4_tos = RT_TOS(iph->tos); 1191 fl4.flowi4_oif = rt->dst.dev->ifindex; 1192 fl4.flowi4_iif = skb->dev->ifindex; 1193 fl4.flowi4_mark = skb->mark; 1194 1195 rcu_read_lock(); 1196 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1197 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1198 else 1199 src = inet_select_addr(rt->dst.dev, 1200 rt_nexthop(rt, iph->daddr), 1201 RT_SCOPE_UNIVERSE); 1202 rcu_read_unlock(); 1203 } 1204 memcpy(addr, &src, 4); 1205 } 1206 1207 #ifdef CONFIG_IP_ROUTE_CLASSID 1208 static void set_class_tag(struct rtable *rt, u32 tag) 1209 { 1210 if (!(rt->dst.tclassid & 0xFFFF)) 1211 rt->dst.tclassid |= tag & 0xFFFF; 1212 if (!(rt->dst.tclassid & 0xFFFF0000)) 1213 rt->dst.tclassid |= tag & 0xFFFF0000; 1214 } 1215 #endif 1216 1217 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1218 { 1219 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1220 1221 if (advmss == 0) { 1222 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1223 ip_rt_min_advmss); 1224 if (advmss > 65535 - 40) 1225 advmss = 65535 - 40; 1226 } 1227 return advmss; 1228 } 1229 1230 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1231 { 1232 const struct rtable *rt = (const struct rtable *) dst; 1233 unsigned int mtu = rt->rt_pmtu; 1234 1235 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1236 mtu = dst_metric_raw(dst, RTAX_MTU); 1237 1238 if (mtu) 1239 return mtu; 1240 1241 mtu = dst->dev->mtu; 1242 1243 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1244 if (rt->rt_uses_gateway && mtu > 576) 1245 mtu = 576; 1246 } 1247 1248 return min_t(unsigned int, mtu, IP_MAX_MTU); 1249 } 1250 1251 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1252 { 1253 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1254 struct fib_nh_exception *fnhe; 1255 u32 hval; 1256 1257 if (!hash) 1258 return NULL; 1259 1260 hval = fnhe_hashfun(daddr); 1261 1262 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1263 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1264 if (fnhe->fnhe_daddr == daddr) 1265 return fnhe; 1266 } 1267 return NULL; 1268 } 1269 1270 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1271 __be32 daddr) 1272 { 1273 bool ret = false; 1274 1275 spin_lock_bh(&fnhe_lock); 1276 1277 if (daddr == fnhe->fnhe_daddr) { 1278 struct rtable __rcu **porig; 1279 struct rtable *orig; 1280 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1281 1282 if (rt_is_input_route(rt)) 1283 porig = &fnhe->fnhe_rth_input; 1284 else 1285 porig = &fnhe->fnhe_rth_output; 1286 orig = rcu_dereference(*porig); 1287 1288 if (fnhe->fnhe_genid != genid) { 1289 fnhe->fnhe_genid = genid; 1290 fnhe->fnhe_gw = 0; 1291 fnhe->fnhe_pmtu = 0; 1292 fnhe->fnhe_expires = 0; 1293 fnhe_flush_routes(fnhe); 1294 orig = NULL; 1295 } 1296 fill_route_from_fnhe(rt, fnhe); 1297 if (!rt->rt_gateway) 1298 rt->rt_gateway = daddr; 1299 1300 if (!(rt->dst.flags & DST_NOCACHE)) { 1301 rcu_assign_pointer(*porig, rt); 1302 if (orig) 1303 rt_free(orig); 1304 ret = true; 1305 } 1306 1307 fnhe->fnhe_stamp = jiffies; 1308 } 1309 spin_unlock_bh(&fnhe_lock); 1310 1311 return ret; 1312 } 1313 1314 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1315 { 1316 struct rtable *orig, *prev, **p; 1317 bool ret = true; 1318 1319 if (rt_is_input_route(rt)) { 1320 p = (struct rtable **)&nh->nh_rth_input; 1321 } else { 1322 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1323 } 1324 orig = *p; 1325 1326 prev = cmpxchg(p, orig, rt); 1327 if (prev == orig) { 1328 if (orig) 1329 rt_free(orig); 1330 } else 1331 ret = false; 1332 1333 return ret; 1334 } 1335 1336 struct uncached_list { 1337 spinlock_t lock; 1338 struct list_head head; 1339 }; 1340 1341 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1342 1343 static void rt_add_uncached_list(struct rtable *rt) 1344 { 1345 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1346 1347 rt->rt_uncached_list = ul; 1348 1349 spin_lock_bh(&ul->lock); 1350 list_add_tail(&rt->rt_uncached, &ul->head); 1351 spin_unlock_bh(&ul->lock); 1352 } 1353 1354 static void ipv4_dst_destroy(struct dst_entry *dst) 1355 { 1356 struct rtable *rt = (struct rtable *) dst; 1357 1358 if (!list_empty(&rt->rt_uncached)) { 1359 struct uncached_list *ul = rt->rt_uncached_list; 1360 1361 spin_lock_bh(&ul->lock); 1362 list_del(&rt->rt_uncached); 1363 spin_unlock_bh(&ul->lock); 1364 } 1365 } 1366 1367 void rt_flush_dev(struct net_device *dev) 1368 { 1369 struct net *net = dev_net(dev); 1370 struct rtable *rt; 1371 int cpu; 1372 1373 for_each_possible_cpu(cpu) { 1374 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1375 1376 spin_lock_bh(&ul->lock); 1377 list_for_each_entry(rt, &ul->head, rt_uncached) { 1378 if (rt->dst.dev != dev) 1379 continue; 1380 rt->dst.dev = net->loopback_dev; 1381 dev_hold(rt->dst.dev); 1382 dev_put(dev); 1383 } 1384 spin_unlock_bh(&ul->lock); 1385 } 1386 } 1387 1388 static bool rt_cache_valid(const struct rtable *rt) 1389 { 1390 return rt && 1391 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1392 !rt_is_expired(rt); 1393 } 1394 1395 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1396 const struct fib_result *res, 1397 struct fib_nh_exception *fnhe, 1398 struct fib_info *fi, u16 type, u32 itag) 1399 { 1400 bool cached = false; 1401 1402 if (fi) { 1403 struct fib_nh *nh = &FIB_RES_NH(*res); 1404 1405 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1406 rt->rt_gateway = nh->nh_gw; 1407 rt->rt_uses_gateway = 1; 1408 } 1409 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1410 #ifdef CONFIG_IP_ROUTE_CLASSID 1411 rt->dst.tclassid = nh->nh_tclassid; 1412 #endif 1413 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 1414 if (unlikely(fnhe)) 1415 cached = rt_bind_exception(rt, fnhe, daddr); 1416 else if (!(rt->dst.flags & DST_NOCACHE)) 1417 cached = rt_cache_route(nh, rt); 1418 if (unlikely(!cached)) { 1419 /* Routes we intend to cache in nexthop exception or 1420 * FIB nexthop have the DST_NOCACHE bit clear. 1421 * However, if we are unsuccessful at storing this 1422 * route into the cache we really need to set it. 1423 */ 1424 rt->dst.flags |= DST_NOCACHE; 1425 if (!rt->rt_gateway) 1426 rt->rt_gateway = daddr; 1427 rt_add_uncached_list(rt); 1428 } 1429 } else 1430 rt_add_uncached_list(rt); 1431 1432 #ifdef CONFIG_IP_ROUTE_CLASSID 1433 #ifdef CONFIG_IP_MULTIPLE_TABLES 1434 set_class_tag(rt, res->tclassid); 1435 #endif 1436 set_class_tag(rt, itag); 1437 #endif 1438 } 1439 1440 static struct rtable *rt_dst_alloc(struct net_device *dev, 1441 unsigned int flags, u16 type, 1442 bool nopolicy, bool noxfrm, bool will_cache) 1443 { 1444 struct rtable *rt; 1445 1446 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1447 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1448 (nopolicy ? DST_NOPOLICY : 0) | 1449 (noxfrm ? DST_NOXFRM : 0)); 1450 1451 if (rt) { 1452 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1453 rt->rt_flags = flags; 1454 rt->rt_type = type; 1455 rt->rt_is_input = 0; 1456 rt->rt_iif = 0; 1457 rt->rt_pmtu = 0; 1458 rt->rt_gateway = 0; 1459 rt->rt_uses_gateway = 0; 1460 rt->rt_table_id = 0; 1461 INIT_LIST_HEAD(&rt->rt_uncached); 1462 1463 rt->dst.output = ip_output; 1464 if (flags & RTCF_LOCAL) 1465 rt->dst.input = ip_local_deliver; 1466 } 1467 1468 return rt; 1469 } 1470 1471 /* called in rcu_read_lock() section */ 1472 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1473 u8 tos, struct net_device *dev, int our) 1474 { 1475 struct rtable *rth; 1476 struct in_device *in_dev = __in_dev_get_rcu(dev); 1477 unsigned int flags = RTCF_MULTICAST; 1478 u32 itag = 0; 1479 int err; 1480 1481 /* Primary sanity checks. */ 1482 1483 if (!in_dev) 1484 return -EINVAL; 1485 1486 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1487 skb->protocol != htons(ETH_P_IP)) 1488 goto e_inval; 1489 1490 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1491 if (ipv4_is_loopback(saddr)) 1492 goto e_inval; 1493 1494 if (ipv4_is_zeronet(saddr)) { 1495 if (!ipv4_is_local_multicast(daddr)) 1496 goto e_inval; 1497 } else { 1498 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1499 in_dev, &itag); 1500 if (err < 0) 1501 goto e_err; 1502 } 1503 if (our) 1504 flags |= RTCF_LOCAL; 1505 1506 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1507 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1508 if (!rth) 1509 goto e_nobufs; 1510 1511 #ifdef CONFIG_IP_ROUTE_CLASSID 1512 rth->dst.tclassid = itag; 1513 #endif 1514 rth->dst.output = ip_rt_bug; 1515 rth->rt_is_input= 1; 1516 1517 #ifdef CONFIG_IP_MROUTE 1518 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1519 rth->dst.input = ip_mr_input; 1520 #endif 1521 RT_CACHE_STAT_INC(in_slow_mc); 1522 1523 skb_dst_set(skb, &rth->dst); 1524 return 0; 1525 1526 e_nobufs: 1527 return -ENOBUFS; 1528 e_inval: 1529 return -EINVAL; 1530 e_err: 1531 return err; 1532 } 1533 1534 1535 static void ip_handle_martian_source(struct net_device *dev, 1536 struct in_device *in_dev, 1537 struct sk_buff *skb, 1538 __be32 daddr, 1539 __be32 saddr) 1540 { 1541 RT_CACHE_STAT_INC(in_martian_src); 1542 #ifdef CONFIG_IP_ROUTE_VERBOSE 1543 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1544 /* 1545 * RFC1812 recommendation, if source is martian, 1546 * the only hint is MAC header. 1547 */ 1548 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1549 &daddr, &saddr, dev->name); 1550 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1551 print_hex_dump(KERN_WARNING, "ll header: ", 1552 DUMP_PREFIX_OFFSET, 16, 1, 1553 skb_mac_header(skb), 1554 dev->hard_header_len, true); 1555 } 1556 } 1557 #endif 1558 } 1559 1560 /* called in rcu_read_lock() section */ 1561 static int __mkroute_input(struct sk_buff *skb, 1562 const struct fib_result *res, 1563 struct in_device *in_dev, 1564 __be32 daddr, __be32 saddr, u32 tos) 1565 { 1566 struct fib_nh_exception *fnhe; 1567 struct rtable *rth; 1568 int err; 1569 struct in_device *out_dev; 1570 bool do_cache; 1571 u32 itag = 0; 1572 1573 /* get a working reference to the output device */ 1574 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1575 if (!out_dev) { 1576 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1577 return -EINVAL; 1578 } 1579 1580 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1581 in_dev->dev, in_dev, &itag); 1582 if (err < 0) { 1583 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1584 saddr); 1585 1586 goto cleanup; 1587 } 1588 1589 do_cache = res->fi && !itag; 1590 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1591 skb->protocol == htons(ETH_P_IP) && 1592 (IN_DEV_SHARED_MEDIA(out_dev) || 1593 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1594 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1595 1596 if (skb->protocol != htons(ETH_P_IP)) { 1597 /* Not IP (i.e. ARP). Do not create route, if it is 1598 * invalid for proxy arp. DNAT routes are always valid. 1599 * 1600 * Proxy arp feature have been extended to allow, ARP 1601 * replies back to the same interface, to support 1602 * Private VLAN switch technologies. See arp.c. 1603 */ 1604 if (out_dev == in_dev && 1605 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1606 err = -EINVAL; 1607 goto cleanup; 1608 } 1609 } 1610 1611 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1612 if (do_cache) { 1613 if (fnhe) 1614 rth = rcu_dereference(fnhe->fnhe_rth_input); 1615 else 1616 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1617 1618 if (rt_cache_valid(rth)) { 1619 skb_dst_set_noref(skb, &rth->dst); 1620 goto out; 1621 } 1622 } 1623 1624 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1625 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1626 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1627 if (!rth) { 1628 err = -ENOBUFS; 1629 goto cleanup; 1630 } 1631 1632 rth->rt_is_input = 1; 1633 if (res->table) 1634 rth->rt_table_id = res->table->tb_id; 1635 RT_CACHE_STAT_INC(in_slow_tot); 1636 1637 rth->dst.input = ip_forward; 1638 1639 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); 1640 if (lwtunnel_output_redirect(rth->dst.lwtstate)) { 1641 rth->dst.lwtstate->orig_output = rth->dst.output; 1642 rth->dst.output = lwtunnel_output; 1643 } 1644 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 1645 rth->dst.lwtstate->orig_input = rth->dst.input; 1646 rth->dst.input = lwtunnel_input; 1647 } 1648 skb_dst_set(skb, &rth->dst); 1649 out: 1650 err = 0; 1651 cleanup: 1652 return err; 1653 } 1654 1655 static int ip_mkroute_input(struct sk_buff *skb, 1656 struct fib_result *res, 1657 const struct flowi4 *fl4, 1658 struct in_device *in_dev, 1659 __be32 daddr, __be32 saddr, u32 tos) 1660 { 1661 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1662 if (res->fi && res->fi->fib_nhs > 1) 1663 fib_select_multipath(res); 1664 #endif 1665 1666 /* create a routing cache entry */ 1667 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1668 } 1669 1670 /* 1671 * NOTE. We drop all the packets that has local source 1672 * addresses, because every properly looped back packet 1673 * must have correct destination already attached by output routine. 1674 * 1675 * Such approach solves two big problems: 1676 * 1. Not simplex devices are handled properly. 1677 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1678 * called with rcu_read_lock() 1679 */ 1680 1681 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1682 u8 tos, struct net_device *dev) 1683 { 1684 struct fib_result res; 1685 struct in_device *in_dev = __in_dev_get_rcu(dev); 1686 struct ip_tunnel_info *tun_info; 1687 struct flowi4 fl4; 1688 unsigned int flags = 0; 1689 u32 itag = 0; 1690 struct rtable *rth; 1691 int err = -EINVAL; 1692 struct net *net = dev_net(dev); 1693 bool do_cache; 1694 1695 /* IP on this device is disabled. */ 1696 1697 if (!in_dev) 1698 goto out; 1699 1700 /* Check for the most weird martians, which can be not detected 1701 by fib_lookup. 1702 */ 1703 1704 tun_info = skb_tunnel_info(skb); 1705 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1706 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1707 else 1708 fl4.flowi4_tun_key.tun_id = 0; 1709 skb_dst_drop(skb); 1710 1711 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1712 goto martian_source; 1713 1714 res.fi = NULL; 1715 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1716 goto brd_input; 1717 1718 /* Accept zero addresses only to limited broadcast; 1719 * I even do not know to fix it or not. Waiting for complains :-) 1720 */ 1721 if (ipv4_is_zeronet(saddr)) 1722 goto martian_source; 1723 1724 if (ipv4_is_zeronet(daddr)) 1725 goto martian_destination; 1726 1727 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1728 * and call it once if daddr or/and saddr are loopback addresses 1729 */ 1730 if (ipv4_is_loopback(daddr)) { 1731 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1732 goto martian_destination; 1733 } else if (ipv4_is_loopback(saddr)) { 1734 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1735 goto martian_source; 1736 } 1737 1738 /* 1739 * Now we are ready to route packet. 1740 */ 1741 fl4.flowi4_oif = 0; 1742 fl4.flowi4_iif = vrf_master_ifindex_rcu(dev) ? : dev->ifindex; 1743 fl4.flowi4_mark = skb->mark; 1744 fl4.flowi4_tos = tos; 1745 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1746 fl4.daddr = daddr; 1747 fl4.saddr = saddr; 1748 err = fib_lookup(net, &fl4, &res, 0); 1749 if (err != 0) { 1750 if (!IN_DEV_FORWARD(in_dev)) 1751 err = -EHOSTUNREACH; 1752 goto no_route; 1753 } 1754 1755 if (res.type == RTN_BROADCAST) 1756 goto brd_input; 1757 1758 if (res.type == RTN_LOCAL) { 1759 err = fib_validate_source(skb, saddr, daddr, tos, 1760 0, dev, in_dev, &itag); 1761 if (err < 0) 1762 goto martian_source_keep_err; 1763 goto local_input; 1764 } 1765 1766 if (!IN_DEV_FORWARD(in_dev)) { 1767 err = -EHOSTUNREACH; 1768 goto no_route; 1769 } 1770 if (res.type != RTN_UNICAST) 1771 goto martian_destination; 1772 1773 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1774 out: return err; 1775 1776 brd_input: 1777 if (skb->protocol != htons(ETH_P_IP)) 1778 goto e_inval; 1779 1780 if (!ipv4_is_zeronet(saddr)) { 1781 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1782 in_dev, &itag); 1783 if (err < 0) 1784 goto martian_source_keep_err; 1785 } 1786 flags |= RTCF_BROADCAST; 1787 res.type = RTN_BROADCAST; 1788 RT_CACHE_STAT_INC(in_brd); 1789 1790 local_input: 1791 do_cache = false; 1792 if (res.fi) { 1793 if (!itag) { 1794 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1795 if (rt_cache_valid(rth)) { 1796 skb_dst_set_noref(skb, &rth->dst); 1797 err = 0; 1798 goto out; 1799 } 1800 do_cache = true; 1801 } 1802 } 1803 1804 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type, 1805 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1806 if (!rth) 1807 goto e_nobufs; 1808 1809 rth->dst.output= ip_rt_bug; 1810 #ifdef CONFIG_IP_ROUTE_CLASSID 1811 rth->dst.tclassid = itag; 1812 #endif 1813 rth->rt_is_input = 1; 1814 if (res.table) 1815 rth->rt_table_id = res.table->tb_id; 1816 1817 RT_CACHE_STAT_INC(in_slow_tot); 1818 if (res.type == RTN_UNREACHABLE) { 1819 rth->dst.input= ip_error; 1820 rth->dst.error= -err; 1821 rth->rt_flags &= ~RTCF_LOCAL; 1822 } 1823 if (do_cache) { 1824 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { 1825 rth->dst.flags |= DST_NOCACHE; 1826 rt_add_uncached_list(rth); 1827 } 1828 } 1829 skb_dst_set(skb, &rth->dst); 1830 err = 0; 1831 goto out; 1832 1833 no_route: 1834 RT_CACHE_STAT_INC(in_no_route); 1835 res.type = RTN_UNREACHABLE; 1836 res.fi = NULL; 1837 goto local_input; 1838 1839 /* 1840 * Do not cache martian addresses: they should be logged (RFC1812) 1841 */ 1842 martian_destination: 1843 RT_CACHE_STAT_INC(in_martian_dst); 1844 #ifdef CONFIG_IP_ROUTE_VERBOSE 1845 if (IN_DEV_LOG_MARTIANS(in_dev)) 1846 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1847 &daddr, &saddr, dev->name); 1848 #endif 1849 1850 e_inval: 1851 err = -EINVAL; 1852 goto out; 1853 1854 e_nobufs: 1855 err = -ENOBUFS; 1856 goto out; 1857 1858 martian_source: 1859 err = -EINVAL; 1860 martian_source_keep_err: 1861 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1862 goto out; 1863 } 1864 1865 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1866 u8 tos, struct net_device *dev) 1867 { 1868 int res; 1869 1870 rcu_read_lock(); 1871 1872 /* Multicast recognition logic is moved from route cache to here. 1873 The problem was that too many Ethernet cards have broken/missing 1874 hardware multicast filters :-( As result the host on multicasting 1875 network acquires a lot of useless route cache entries, sort of 1876 SDR messages from all the world. Now we try to get rid of them. 1877 Really, provided software IP multicast filter is organized 1878 reasonably (at least, hashed), it does not result in a slowdown 1879 comparing with route cache reject entries. 1880 Note, that multicast routers are not affected, because 1881 route cache entry is created eventually. 1882 */ 1883 if (ipv4_is_multicast(daddr)) { 1884 struct in_device *in_dev = __in_dev_get_rcu(dev); 1885 1886 if (in_dev) { 1887 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1888 ip_hdr(skb)->protocol); 1889 if (our 1890 #ifdef CONFIG_IP_MROUTE 1891 || 1892 (!ipv4_is_local_multicast(daddr) && 1893 IN_DEV_MFORWARD(in_dev)) 1894 #endif 1895 ) { 1896 int res = ip_route_input_mc(skb, daddr, saddr, 1897 tos, dev, our); 1898 rcu_read_unlock(); 1899 return res; 1900 } 1901 } 1902 rcu_read_unlock(); 1903 return -EINVAL; 1904 } 1905 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1906 rcu_read_unlock(); 1907 return res; 1908 } 1909 EXPORT_SYMBOL(ip_route_input_noref); 1910 1911 /* called with rcu_read_lock() */ 1912 static struct rtable *__mkroute_output(const struct fib_result *res, 1913 const struct flowi4 *fl4, int orig_oif, 1914 struct net_device *dev_out, 1915 unsigned int flags) 1916 { 1917 struct fib_info *fi = res->fi; 1918 struct fib_nh_exception *fnhe; 1919 struct in_device *in_dev; 1920 u16 type = res->type; 1921 struct rtable *rth; 1922 bool do_cache; 1923 1924 in_dev = __in_dev_get_rcu(dev_out); 1925 if (!in_dev) 1926 return ERR_PTR(-EINVAL); 1927 1928 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1929 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1930 return ERR_PTR(-EINVAL); 1931 1932 if (ipv4_is_lbcast(fl4->daddr)) 1933 type = RTN_BROADCAST; 1934 else if (ipv4_is_multicast(fl4->daddr)) 1935 type = RTN_MULTICAST; 1936 else if (ipv4_is_zeronet(fl4->daddr)) 1937 return ERR_PTR(-EINVAL); 1938 1939 if (dev_out->flags & IFF_LOOPBACK) 1940 flags |= RTCF_LOCAL; 1941 1942 do_cache = true; 1943 if (type == RTN_BROADCAST) { 1944 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1945 fi = NULL; 1946 } else if (type == RTN_MULTICAST) { 1947 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1948 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1949 fl4->flowi4_proto)) 1950 flags &= ~RTCF_LOCAL; 1951 else 1952 do_cache = false; 1953 /* If multicast route do not exist use 1954 * default one, but do not gateway in this case. 1955 * Yes, it is hack. 1956 */ 1957 if (fi && res->prefixlen < 4) 1958 fi = NULL; 1959 } 1960 1961 fnhe = NULL; 1962 do_cache &= fi != NULL; 1963 if (do_cache) { 1964 struct rtable __rcu **prth; 1965 struct fib_nh *nh = &FIB_RES_NH(*res); 1966 1967 fnhe = find_exception(nh, fl4->daddr); 1968 if (fnhe) 1969 prth = &fnhe->fnhe_rth_output; 1970 else { 1971 if (unlikely(fl4->flowi4_flags & 1972 FLOWI_FLAG_KNOWN_NH && 1973 !(nh->nh_gw && 1974 nh->nh_scope == RT_SCOPE_LINK))) { 1975 do_cache = false; 1976 goto add; 1977 } 1978 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 1979 } 1980 rth = rcu_dereference(*prth); 1981 if (rt_cache_valid(rth)) { 1982 dst_hold(&rth->dst); 1983 return rth; 1984 } 1985 } 1986 1987 add: 1988 rth = rt_dst_alloc(dev_out, flags, type, 1989 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1990 IN_DEV_CONF_GET(in_dev, NOXFRM), 1991 do_cache); 1992 if (!rth) 1993 return ERR_PTR(-ENOBUFS); 1994 1995 rth->rt_iif = orig_oif ? : 0; 1996 if (res->table) 1997 rth->rt_table_id = res->table->tb_id; 1998 1999 RT_CACHE_STAT_INC(out_slow_tot); 2000 2001 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2002 if (flags & RTCF_LOCAL && 2003 !(dev_out->flags & IFF_LOOPBACK)) { 2004 rth->dst.output = ip_mc_output; 2005 RT_CACHE_STAT_INC(out_slow_mc); 2006 } 2007 #ifdef CONFIG_IP_MROUTE 2008 if (type == RTN_MULTICAST) { 2009 if (IN_DEV_MFORWARD(in_dev) && 2010 !ipv4_is_local_multicast(fl4->daddr)) { 2011 rth->dst.input = ip_mr_input; 2012 rth->dst.output = ip_mc_output; 2013 } 2014 } 2015 #endif 2016 } 2017 2018 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 2019 if (lwtunnel_output_redirect(rth->dst.lwtstate)) 2020 rth->dst.output = lwtunnel_output; 2021 2022 return rth; 2023 } 2024 2025 /* 2026 * Major route resolver routine. 2027 */ 2028 2029 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 2030 { 2031 struct net_device *dev_out = NULL; 2032 __u8 tos = RT_FL_TOS(fl4); 2033 unsigned int flags = 0; 2034 struct fib_result res; 2035 struct rtable *rth; 2036 int orig_oif; 2037 2038 res.tclassid = 0; 2039 res.fi = NULL; 2040 res.table = NULL; 2041 2042 orig_oif = fl4->flowi4_oif; 2043 2044 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2045 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2046 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2047 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2048 2049 rcu_read_lock(); 2050 if (fl4->saddr) { 2051 rth = ERR_PTR(-EINVAL); 2052 if (ipv4_is_multicast(fl4->saddr) || 2053 ipv4_is_lbcast(fl4->saddr) || 2054 ipv4_is_zeronet(fl4->saddr)) 2055 goto out; 2056 2057 /* I removed check for oif == dev_out->oif here. 2058 It was wrong for two reasons: 2059 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2060 is assigned to multiple interfaces. 2061 2. Moreover, we are allowed to send packets with saddr 2062 of another iface. --ANK 2063 */ 2064 2065 if (fl4->flowi4_oif == 0 && 2066 (ipv4_is_multicast(fl4->daddr) || 2067 ipv4_is_lbcast(fl4->daddr))) { 2068 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2069 dev_out = __ip_dev_find(net, fl4->saddr, false); 2070 if (!dev_out) 2071 goto out; 2072 2073 /* Special hack: user can direct multicasts 2074 and limited broadcast via necessary interface 2075 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2076 This hack is not just for fun, it allows 2077 vic,vat and friends to work. 2078 They bind socket to loopback, set ttl to zero 2079 and expect that it will work. 2080 From the viewpoint of routing cache they are broken, 2081 because we are not allowed to build multicast path 2082 with loopback source addr (look, routing cache 2083 cannot know, that ttl is zero, so that packet 2084 will not leave this host and route is valid). 2085 Luckily, this hack is good workaround. 2086 */ 2087 2088 fl4->flowi4_oif = dev_out->ifindex; 2089 goto make_route; 2090 } 2091 2092 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2093 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2094 if (!__ip_dev_find(net, fl4->saddr, false)) 2095 goto out; 2096 } 2097 } 2098 2099 2100 if (fl4->flowi4_oif) { 2101 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2102 rth = ERR_PTR(-ENODEV); 2103 if (!dev_out) 2104 goto out; 2105 2106 /* RACE: Check return value of inet_select_addr instead. */ 2107 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2108 rth = ERR_PTR(-ENETUNREACH); 2109 goto out; 2110 } 2111 if (ipv4_is_local_multicast(fl4->daddr) || 2112 ipv4_is_lbcast(fl4->daddr) || 2113 fl4->flowi4_proto == IPPROTO_IGMP) { 2114 if (!fl4->saddr) 2115 fl4->saddr = inet_select_addr(dev_out, 0, 2116 RT_SCOPE_LINK); 2117 goto make_route; 2118 } 2119 if (!fl4->saddr) { 2120 if (ipv4_is_multicast(fl4->daddr)) 2121 fl4->saddr = inet_select_addr(dev_out, 0, 2122 fl4->flowi4_scope); 2123 else if (!fl4->daddr) 2124 fl4->saddr = inet_select_addr(dev_out, 0, 2125 RT_SCOPE_HOST); 2126 } 2127 if (netif_is_vrf(dev_out) && 2128 !(fl4->flowi4_flags & FLOWI_FLAG_VRFSRC)) { 2129 rth = vrf_dev_get_rth(dev_out); 2130 goto out; 2131 } 2132 } 2133 2134 if (!fl4->daddr) { 2135 fl4->daddr = fl4->saddr; 2136 if (!fl4->daddr) 2137 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2138 dev_out = net->loopback_dev; 2139 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2140 res.type = RTN_LOCAL; 2141 flags |= RTCF_LOCAL; 2142 goto make_route; 2143 } 2144 2145 if (fib_lookup(net, fl4, &res, 0)) { 2146 res.fi = NULL; 2147 res.table = NULL; 2148 if (fl4->flowi4_oif) { 2149 /* Apparently, routing tables are wrong. Assume, 2150 that the destination is on link. 2151 2152 WHY? DW. 2153 Because we are allowed to send to iface 2154 even if it has NO routes and NO assigned 2155 addresses. When oif is specified, routing 2156 tables are looked up with only one purpose: 2157 to catch if destination is gatewayed, rather than 2158 direct. Moreover, if MSG_DONTROUTE is set, 2159 we send packet, ignoring both routing tables 2160 and ifaddr state. --ANK 2161 2162 2163 We could make it even if oif is unknown, 2164 likely IPv6, but we do not. 2165 */ 2166 2167 if (fl4->saddr == 0) 2168 fl4->saddr = inet_select_addr(dev_out, 0, 2169 RT_SCOPE_LINK); 2170 res.type = RTN_UNICAST; 2171 goto make_route; 2172 } 2173 rth = ERR_PTR(-ENETUNREACH); 2174 goto out; 2175 } 2176 2177 if (res.type == RTN_LOCAL) { 2178 if (!fl4->saddr) { 2179 if (res.fi->fib_prefsrc) 2180 fl4->saddr = res.fi->fib_prefsrc; 2181 else 2182 fl4->saddr = fl4->daddr; 2183 } 2184 dev_out = net->loopback_dev; 2185 fl4->flowi4_oif = dev_out->ifindex; 2186 flags |= RTCF_LOCAL; 2187 goto make_route; 2188 } 2189 2190 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2191 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2192 fib_select_multipath(&res); 2193 else 2194 #endif 2195 if (!res.prefixlen && 2196 res.table->tb_num_default > 1 && 2197 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2198 fib_select_default(fl4, &res); 2199 2200 if (!fl4->saddr) 2201 fl4->saddr = FIB_RES_PREFSRC(net, res); 2202 2203 dev_out = FIB_RES_DEV(res); 2204 fl4->flowi4_oif = dev_out->ifindex; 2205 2206 2207 make_route: 2208 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2209 2210 out: 2211 rcu_read_unlock(); 2212 return rth; 2213 } 2214 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2215 2216 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2217 { 2218 return NULL; 2219 } 2220 2221 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2222 { 2223 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2224 2225 return mtu ? : dst->dev->mtu; 2226 } 2227 2228 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2229 struct sk_buff *skb, u32 mtu) 2230 { 2231 } 2232 2233 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2234 struct sk_buff *skb) 2235 { 2236 } 2237 2238 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2239 unsigned long old) 2240 { 2241 return NULL; 2242 } 2243 2244 static struct dst_ops ipv4_dst_blackhole_ops = { 2245 .family = AF_INET, 2246 .check = ipv4_blackhole_dst_check, 2247 .mtu = ipv4_blackhole_mtu, 2248 .default_advmss = ipv4_default_advmss, 2249 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2250 .redirect = ipv4_rt_blackhole_redirect, 2251 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2252 .neigh_lookup = ipv4_neigh_lookup, 2253 }; 2254 2255 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2256 { 2257 struct rtable *ort = (struct rtable *) dst_orig; 2258 struct rtable *rt; 2259 2260 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2261 if (rt) { 2262 struct dst_entry *new = &rt->dst; 2263 2264 new->__use = 1; 2265 new->input = dst_discard; 2266 new->output = dst_discard_sk; 2267 2268 new->dev = ort->dst.dev; 2269 if (new->dev) 2270 dev_hold(new->dev); 2271 2272 rt->rt_is_input = ort->rt_is_input; 2273 rt->rt_iif = ort->rt_iif; 2274 rt->rt_pmtu = ort->rt_pmtu; 2275 2276 rt->rt_genid = rt_genid_ipv4(net); 2277 rt->rt_flags = ort->rt_flags; 2278 rt->rt_type = ort->rt_type; 2279 rt->rt_gateway = ort->rt_gateway; 2280 rt->rt_uses_gateway = ort->rt_uses_gateway; 2281 2282 INIT_LIST_HEAD(&rt->rt_uncached); 2283 dst_free(new); 2284 } 2285 2286 dst_release(dst_orig); 2287 2288 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2289 } 2290 2291 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2292 struct sock *sk) 2293 { 2294 struct rtable *rt = __ip_route_output_key(net, flp4); 2295 2296 if (IS_ERR(rt)) 2297 return rt; 2298 2299 if (flp4->flowi4_proto) 2300 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2301 flowi4_to_flowi(flp4), 2302 sk, 0); 2303 2304 return rt; 2305 } 2306 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2307 2308 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id, 2309 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2310 u32 seq, int event, int nowait, unsigned int flags) 2311 { 2312 struct rtable *rt = skb_rtable(skb); 2313 struct rtmsg *r; 2314 struct nlmsghdr *nlh; 2315 unsigned long expires = 0; 2316 u32 error; 2317 u32 metrics[RTAX_MAX]; 2318 2319 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2320 if (!nlh) 2321 return -EMSGSIZE; 2322 2323 r = nlmsg_data(nlh); 2324 r->rtm_family = AF_INET; 2325 r->rtm_dst_len = 32; 2326 r->rtm_src_len = 0; 2327 r->rtm_tos = fl4->flowi4_tos; 2328 r->rtm_table = table_id; 2329 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2330 goto nla_put_failure; 2331 r->rtm_type = rt->rt_type; 2332 r->rtm_scope = RT_SCOPE_UNIVERSE; 2333 r->rtm_protocol = RTPROT_UNSPEC; 2334 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2335 if (rt->rt_flags & RTCF_NOTIFY) 2336 r->rtm_flags |= RTM_F_NOTIFY; 2337 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2338 r->rtm_flags |= RTCF_DOREDIRECT; 2339 2340 if (nla_put_in_addr(skb, RTA_DST, dst)) 2341 goto nla_put_failure; 2342 if (src) { 2343 r->rtm_src_len = 32; 2344 if (nla_put_in_addr(skb, RTA_SRC, src)) 2345 goto nla_put_failure; 2346 } 2347 if (rt->dst.dev && 2348 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2349 goto nla_put_failure; 2350 #ifdef CONFIG_IP_ROUTE_CLASSID 2351 if (rt->dst.tclassid && 2352 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2353 goto nla_put_failure; 2354 #endif 2355 if (!rt_is_input_route(rt) && 2356 fl4->saddr != src) { 2357 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2358 goto nla_put_failure; 2359 } 2360 if (rt->rt_uses_gateway && 2361 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2362 goto nla_put_failure; 2363 2364 expires = rt->dst.expires; 2365 if (expires) { 2366 unsigned long now = jiffies; 2367 2368 if (time_before(now, expires)) 2369 expires -= now; 2370 else 2371 expires = 0; 2372 } 2373 2374 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2375 if (rt->rt_pmtu && expires) 2376 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2377 if (rtnetlink_put_metrics(skb, metrics) < 0) 2378 goto nla_put_failure; 2379 2380 if (fl4->flowi4_mark && 2381 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2382 goto nla_put_failure; 2383 2384 error = rt->dst.error; 2385 2386 if (rt_is_input_route(rt)) { 2387 #ifdef CONFIG_IP_MROUTE 2388 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2389 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2390 int err = ipmr_get_route(net, skb, 2391 fl4->saddr, fl4->daddr, 2392 r, nowait); 2393 if (err <= 0) { 2394 if (!nowait) { 2395 if (err == 0) 2396 return 0; 2397 goto nla_put_failure; 2398 } else { 2399 if (err == -EMSGSIZE) 2400 goto nla_put_failure; 2401 error = err; 2402 } 2403 } 2404 } else 2405 #endif 2406 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) 2407 goto nla_put_failure; 2408 } 2409 2410 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2411 goto nla_put_failure; 2412 2413 nlmsg_end(skb, nlh); 2414 return 0; 2415 2416 nla_put_failure: 2417 nlmsg_cancel(skb, nlh); 2418 return -EMSGSIZE; 2419 } 2420 2421 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 2422 { 2423 struct net *net = sock_net(in_skb->sk); 2424 struct rtmsg *rtm; 2425 struct nlattr *tb[RTA_MAX+1]; 2426 struct rtable *rt = NULL; 2427 struct flowi4 fl4; 2428 __be32 dst = 0; 2429 __be32 src = 0; 2430 u32 iif; 2431 int err; 2432 int mark; 2433 struct sk_buff *skb; 2434 u32 table_id = RT_TABLE_MAIN; 2435 2436 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2437 if (err < 0) 2438 goto errout; 2439 2440 rtm = nlmsg_data(nlh); 2441 2442 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2443 if (!skb) { 2444 err = -ENOBUFS; 2445 goto errout; 2446 } 2447 2448 /* Reserve room for dummy headers, this skb can pass 2449 through good chunk of routing engine. 2450 */ 2451 skb_reset_mac_header(skb); 2452 skb_reset_network_header(skb); 2453 2454 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2455 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2456 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2457 2458 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2459 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2460 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2461 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2462 2463 memset(&fl4, 0, sizeof(fl4)); 2464 fl4.daddr = dst; 2465 fl4.saddr = src; 2466 fl4.flowi4_tos = rtm->rtm_tos; 2467 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2468 fl4.flowi4_mark = mark; 2469 2470 if (iif) { 2471 struct net_device *dev; 2472 2473 dev = __dev_get_by_index(net, iif); 2474 if (!dev) { 2475 err = -ENODEV; 2476 goto errout_free; 2477 } 2478 2479 skb->protocol = htons(ETH_P_IP); 2480 skb->dev = dev; 2481 skb->mark = mark; 2482 local_bh_disable(); 2483 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2484 local_bh_enable(); 2485 2486 rt = skb_rtable(skb); 2487 if (err == 0 && rt->dst.error) 2488 err = -rt->dst.error; 2489 } else { 2490 rt = ip_route_output_key(net, &fl4); 2491 2492 err = 0; 2493 if (IS_ERR(rt)) 2494 err = PTR_ERR(rt); 2495 } 2496 2497 if (err) 2498 goto errout_free; 2499 2500 skb_dst_set(skb, &rt->dst); 2501 if (rtm->rtm_flags & RTM_F_NOTIFY) 2502 rt->rt_flags |= RTCF_NOTIFY; 2503 2504 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 2505 table_id = rt->rt_table_id; 2506 2507 err = rt_fill_info(net, dst, src, table_id, &fl4, skb, 2508 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2509 RTM_NEWROUTE, 0, 0); 2510 if (err < 0) 2511 goto errout_free; 2512 2513 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2514 errout: 2515 return err; 2516 2517 errout_free: 2518 kfree_skb(skb); 2519 goto errout; 2520 } 2521 2522 void ip_rt_multicast_event(struct in_device *in_dev) 2523 { 2524 rt_cache_flush(dev_net(in_dev->dev)); 2525 } 2526 2527 #ifdef CONFIG_SYSCTL 2528 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2529 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2530 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2531 static int ip_rt_gc_elasticity __read_mostly = 8; 2532 2533 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2534 void __user *buffer, 2535 size_t *lenp, loff_t *ppos) 2536 { 2537 struct net *net = (struct net *)__ctl->extra1; 2538 2539 if (write) { 2540 rt_cache_flush(net); 2541 fnhe_genid_bump(net); 2542 return 0; 2543 } 2544 2545 return -EINVAL; 2546 } 2547 2548 static struct ctl_table ipv4_route_table[] = { 2549 { 2550 .procname = "gc_thresh", 2551 .data = &ipv4_dst_ops.gc_thresh, 2552 .maxlen = sizeof(int), 2553 .mode = 0644, 2554 .proc_handler = proc_dointvec, 2555 }, 2556 { 2557 .procname = "max_size", 2558 .data = &ip_rt_max_size, 2559 .maxlen = sizeof(int), 2560 .mode = 0644, 2561 .proc_handler = proc_dointvec, 2562 }, 2563 { 2564 /* Deprecated. Use gc_min_interval_ms */ 2565 2566 .procname = "gc_min_interval", 2567 .data = &ip_rt_gc_min_interval, 2568 .maxlen = sizeof(int), 2569 .mode = 0644, 2570 .proc_handler = proc_dointvec_jiffies, 2571 }, 2572 { 2573 .procname = "gc_min_interval_ms", 2574 .data = &ip_rt_gc_min_interval, 2575 .maxlen = sizeof(int), 2576 .mode = 0644, 2577 .proc_handler = proc_dointvec_ms_jiffies, 2578 }, 2579 { 2580 .procname = "gc_timeout", 2581 .data = &ip_rt_gc_timeout, 2582 .maxlen = sizeof(int), 2583 .mode = 0644, 2584 .proc_handler = proc_dointvec_jiffies, 2585 }, 2586 { 2587 .procname = "gc_interval", 2588 .data = &ip_rt_gc_interval, 2589 .maxlen = sizeof(int), 2590 .mode = 0644, 2591 .proc_handler = proc_dointvec_jiffies, 2592 }, 2593 { 2594 .procname = "redirect_load", 2595 .data = &ip_rt_redirect_load, 2596 .maxlen = sizeof(int), 2597 .mode = 0644, 2598 .proc_handler = proc_dointvec, 2599 }, 2600 { 2601 .procname = "redirect_number", 2602 .data = &ip_rt_redirect_number, 2603 .maxlen = sizeof(int), 2604 .mode = 0644, 2605 .proc_handler = proc_dointvec, 2606 }, 2607 { 2608 .procname = "redirect_silence", 2609 .data = &ip_rt_redirect_silence, 2610 .maxlen = sizeof(int), 2611 .mode = 0644, 2612 .proc_handler = proc_dointvec, 2613 }, 2614 { 2615 .procname = "error_cost", 2616 .data = &ip_rt_error_cost, 2617 .maxlen = sizeof(int), 2618 .mode = 0644, 2619 .proc_handler = proc_dointvec, 2620 }, 2621 { 2622 .procname = "error_burst", 2623 .data = &ip_rt_error_burst, 2624 .maxlen = sizeof(int), 2625 .mode = 0644, 2626 .proc_handler = proc_dointvec, 2627 }, 2628 { 2629 .procname = "gc_elasticity", 2630 .data = &ip_rt_gc_elasticity, 2631 .maxlen = sizeof(int), 2632 .mode = 0644, 2633 .proc_handler = proc_dointvec, 2634 }, 2635 { 2636 .procname = "mtu_expires", 2637 .data = &ip_rt_mtu_expires, 2638 .maxlen = sizeof(int), 2639 .mode = 0644, 2640 .proc_handler = proc_dointvec_jiffies, 2641 }, 2642 { 2643 .procname = "min_pmtu", 2644 .data = &ip_rt_min_pmtu, 2645 .maxlen = sizeof(int), 2646 .mode = 0644, 2647 .proc_handler = proc_dointvec, 2648 }, 2649 { 2650 .procname = "min_adv_mss", 2651 .data = &ip_rt_min_advmss, 2652 .maxlen = sizeof(int), 2653 .mode = 0644, 2654 .proc_handler = proc_dointvec, 2655 }, 2656 { } 2657 }; 2658 2659 static struct ctl_table ipv4_route_flush_table[] = { 2660 { 2661 .procname = "flush", 2662 .maxlen = sizeof(int), 2663 .mode = 0200, 2664 .proc_handler = ipv4_sysctl_rtcache_flush, 2665 }, 2666 { }, 2667 }; 2668 2669 static __net_init int sysctl_route_net_init(struct net *net) 2670 { 2671 struct ctl_table *tbl; 2672 2673 tbl = ipv4_route_flush_table; 2674 if (!net_eq(net, &init_net)) { 2675 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2676 if (!tbl) 2677 goto err_dup; 2678 2679 /* Don't export sysctls to unprivileged users */ 2680 if (net->user_ns != &init_user_ns) 2681 tbl[0].procname = NULL; 2682 } 2683 tbl[0].extra1 = net; 2684 2685 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2686 if (!net->ipv4.route_hdr) 2687 goto err_reg; 2688 return 0; 2689 2690 err_reg: 2691 if (tbl != ipv4_route_flush_table) 2692 kfree(tbl); 2693 err_dup: 2694 return -ENOMEM; 2695 } 2696 2697 static __net_exit void sysctl_route_net_exit(struct net *net) 2698 { 2699 struct ctl_table *tbl; 2700 2701 tbl = net->ipv4.route_hdr->ctl_table_arg; 2702 unregister_net_sysctl_table(net->ipv4.route_hdr); 2703 BUG_ON(tbl == ipv4_route_flush_table); 2704 kfree(tbl); 2705 } 2706 2707 static __net_initdata struct pernet_operations sysctl_route_ops = { 2708 .init = sysctl_route_net_init, 2709 .exit = sysctl_route_net_exit, 2710 }; 2711 #endif 2712 2713 static __net_init int rt_genid_init(struct net *net) 2714 { 2715 atomic_set(&net->ipv4.rt_genid, 0); 2716 atomic_set(&net->fnhe_genid, 0); 2717 get_random_bytes(&net->ipv4.dev_addr_genid, 2718 sizeof(net->ipv4.dev_addr_genid)); 2719 return 0; 2720 } 2721 2722 static __net_initdata struct pernet_operations rt_genid_ops = { 2723 .init = rt_genid_init, 2724 }; 2725 2726 static int __net_init ipv4_inetpeer_init(struct net *net) 2727 { 2728 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2729 2730 if (!bp) 2731 return -ENOMEM; 2732 inet_peer_base_init(bp); 2733 net->ipv4.peers = bp; 2734 return 0; 2735 } 2736 2737 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2738 { 2739 struct inet_peer_base *bp = net->ipv4.peers; 2740 2741 net->ipv4.peers = NULL; 2742 inetpeer_invalidate_tree(bp); 2743 kfree(bp); 2744 } 2745 2746 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2747 .init = ipv4_inetpeer_init, 2748 .exit = ipv4_inetpeer_exit, 2749 }; 2750 2751 #ifdef CONFIG_IP_ROUTE_CLASSID 2752 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2753 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2754 2755 int __init ip_rt_init(void) 2756 { 2757 int rc = 0; 2758 int cpu; 2759 2760 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); 2761 if (!ip_idents) 2762 panic("IP: failed to allocate ip_idents\n"); 2763 2764 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 2765 2766 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 2767 if (!ip_tstamps) 2768 panic("IP: failed to allocate ip_tstamps\n"); 2769 2770 for_each_possible_cpu(cpu) { 2771 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 2772 2773 INIT_LIST_HEAD(&ul->head); 2774 spin_lock_init(&ul->lock); 2775 } 2776 #ifdef CONFIG_IP_ROUTE_CLASSID 2777 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2778 if (!ip_rt_acct) 2779 panic("IP: failed to allocate ip_rt_acct\n"); 2780 #endif 2781 2782 ipv4_dst_ops.kmem_cachep = 2783 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2784 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2785 2786 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2787 2788 if (dst_entries_init(&ipv4_dst_ops) < 0) 2789 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2790 2791 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2792 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2793 2794 ipv4_dst_ops.gc_thresh = ~0; 2795 ip_rt_max_size = INT_MAX; 2796 2797 devinet_init(); 2798 ip_fib_init(); 2799 2800 if (ip_rt_proc_init()) 2801 pr_err("Unable to create route proc files\n"); 2802 #ifdef CONFIG_XFRM 2803 xfrm_init(); 2804 xfrm4_init(); 2805 #endif 2806 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2807 2808 #ifdef CONFIG_SYSCTL 2809 register_pernet_subsys(&sysctl_route_ops); 2810 #endif 2811 register_pernet_subsys(&rt_genid_ops); 2812 register_pernet_subsys(&ipv4_inetpeer_ops); 2813 return rc; 2814 } 2815 2816 #ifdef CONFIG_SYSCTL 2817 /* 2818 * We really need to sanitize the damn ipv4 init order, then all 2819 * this nonsense will go away. 2820 */ 2821 void __init ip_static_sysctl_init(void) 2822 { 2823 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2824 } 2825 #endif 2826