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 bool nopolicy, bool noxfrm, bool will_cache) 1442 { 1443 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1444 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | 1445 (nopolicy ? DST_NOPOLICY : 0) | 1446 (noxfrm ? DST_NOXFRM : 0)); 1447 } 1448 1449 /* called in rcu_read_lock() section */ 1450 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1451 u8 tos, struct net_device *dev, int our) 1452 { 1453 struct rtable *rth; 1454 struct in_device *in_dev = __in_dev_get_rcu(dev); 1455 u32 itag = 0; 1456 int err; 1457 1458 /* Primary sanity checks. */ 1459 1460 if (!in_dev) 1461 return -EINVAL; 1462 1463 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1464 skb->protocol != htons(ETH_P_IP)) 1465 goto e_inval; 1466 1467 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1468 if (ipv4_is_loopback(saddr)) 1469 goto e_inval; 1470 1471 if (ipv4_is_zeronet(saddr)) { 1472 if (!ipv4_is_local_multicast(daddr)) 1473 goto e_inval; 1474 } else { 1475 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1476 in_dev, &itag); 1477 if (err < 0) 1478 goto e_err; 1479 } 1480 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, 1481 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1482 if (!rth) 1483 goto e_nobufs; 1484 1485 #ifdef CONFIG_IP_ROUTE_CLASSID 1486 rth->dst.tclassid = itag; 1487 #endif 1488 rth->dst.output = ip_rt_bug; 1489 1490 rth->rt_genid = rt_genid_ipv4(dev_net(dev)); 1491 rth->rt_flags = RTCF_MULTICAST; 1492 rth->rt_type = RTN_MULTICAST; 1493 rth->rt_is_input= 1; 1494 rth->rt_iif = 0; 1495 rth->rt_pmtu = 0; 1496 rth->rt_gateway = 0; 1497 rth->rt_uses_gateway = 0; 1498 INIT_LIST_HEAD(&rth->rt_uncached); 1499 if (our) { 1500 rth->dst.input= ip_local_deliver; 1501 rth->rt_flags |= RTCF_LOCAL; 1502 } 1503 1504 #ifdef CONFIG_IP_MROUTE 1505 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1506 rth->dst.input = ip_mr_input; 1507 #endif 1508 RT_CACHE_STAT_INC(in_slow_mc); 1509 1510 skb_dst_set(skb, &rth->dst); 1511 return 0; 1512 1513 e_nobufs: 1514 return -ENOBUFS; 1515 e_inval: 1516 return -EINVAL; 1517 e_err: 1518 return err; 1519 } 1520 1521 1522 static void ip_handle_martian_source(struct net_device *dev, 1523 struct in_device *in_dev, 1524 struct sk_buff *skb, 1525 __be32 daddr, 1526 __be32 saddr) 1527 { 1528 RT_CACHE_STAT_INC(in_martian_src); 1529 #ifdef CONFIG_IP_ROUTE_VERBOSE 1530 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1531 /* 1532 * RFC1812 recommendation, if source is martian, 1533 * the only hint is MAC header. 1534 */ 1535 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1536 &daddr, &saddr, dev->name); 1537 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1538 print_hex_dump(KERN_WARNING, "ll header: ", 1539 DUMP_PREFIX_OFFSET, 16, 1, 1540 skb_mac_header(skb), 1541 dev->hard_header_len, true); 1542 } 1543 } 1544 #endif 1545 } 1546 1547 /* called in rcu_read_lock() section */ 1548 static int __mkroute_input(struct sk_buff *skb, 1549 const struct fib_result *res, 1550 struct in_device *in_dev, 1551 __be32 daddr, __be32 saddr, u32 tos) 1552 { 1553 struct fib_nh_exception *fnhe; 1554 struct rtable *rth; 1555 int err; 1556 struct in_device *out_dev; 1557 bool do_cache; 1558 u32 itag = 0; 1559 1560 /* get a working reference to the output device */ 1561 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1562 if (!out_dev) { 1563 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1564 return -EINVAL; 1565 } 1566 1567 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1568 in_dev->dev, in_dev, &itag); 1569 if (err < 0) { 1570 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1571 saddr); 1572 1573 goto cleanup; 1574 } 1575 1576 do_cache = res->fi && !itag; 1577 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1578 skb->protocol == htons(ETH_P_IP) && 1579 (IN_DEV_SHARED_MEDIA(out_dev) || 1580 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1581 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1582 1583 if (skb->protocol != htons(ETH_P_IP)) { 1584 /* Not IP (i.e. ARP). Do not create route, if it is 1585 * invalid for proxy arp. DNAT routes are always valid. 1586 * 1587 * Proxy arp feature have been extended to allow, ARP 1588 * replies back to the same interface, to support 1589 * Private VLAN switch technologies. See arp.c. 1590 */ 1591 if (out_dev == in_dev && 1592 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1593 err = -EINVAL; 1594 goto cleanup; 1595 } 1596 } 1597 1598 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1599 if (do_cache) { 1600 if (fnhe) 1601 rth = rcu_dereference(fnhe->fnhe_rth_input); 1602 else 1603 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1604 1605 if (rt_cache_valid(rth)) { 1606 skb_dst_set_noref(skb, &rth->dst); 1607 goto out; 1608 } 1609 } 1610 1611 rth = rt_dst_alloc(out_dev->dev, 1612 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1613 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1614 if (!rth) { 1615 err = -ENOBUFS; 1616 goto cleanup; 1617 } 1618 1619 rth->rt_genid = rt_genid_ipv4(dev_net(rth->dst.dev)); 1620 rth->rt_flags = 0; 1621 rth->rt_type = res->type; 1622 rth->rt_is_input = 1; 1623 rth->rt_iif = 0; 1624 rth->rt_pmtu = 0; 1625 rth->rt_gateway = 0; 1626 rth->rt_uses_gateway = 0; 1627 INIT_LIST_HEAD(&rth->rt_uncached); 1628 RT_CACHE_STAT_INC(in_slow_tot); 1629 1630 rth->dst.input = ip_forward; 1631 rth->dst.output = ip_output; 1632 1633 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag); 1634 if (lwtunnel_output_redirect(rth->dst.lwtstate)) { 1635 rth->dst.lwtstate->orig_output = rth->dst.output; 1636 rth->dst.output = lwtunnel_output; 1637 } 1638 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 1639 rth->dst.lwtstate->orig_input = rth->dst.input; 1640 rth->dst.input = lwtunnel_input; 1641 } 1642 skb_dst_set(skb, &rth->dst); 1643 out: 1644 err = 0; 1645 cleanup: 1646 return err; 1647 } 1648 1649 static int ip_mkroute_input(struct sk_buff *skb, 1650 struct fib_result *res, 1651 const struct flowi4 *fl4, 1652 struct in_device *in_dev, 1653 __be32 daddr, __be32 saddr, u32 tos) 1654 { 1655 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1656 if (res->fi && res->fi->fib_nhs > 1) 1657 fib_select_multipath(res); 1658 #endif 1659 1660 /* create a routing cache entry */ 1661 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1662 } 1663 1664 /* 1665 * NOTE. We drop all the packets that has local source 1666 * addresses, because every properly looped back packet 1667 * must have correct destination already attached by output routine. 1668 * 1669 * Such approach solves two big problems: 1670 * 1. Not simplex devices are handled properly. 1671 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1672 * called with rcu_read_lock() 1673 */ 1674 1675 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1676 u8 tos, struct net_device *dev) 1677 { 1678 struct fib_result res; 1679 struct in_device *in_dev = __in_dev_get_rcu(dev); 1680 struct ip_tunnel_info *tun_info; 1681 struct flowi4 fl4; 1682 unsigned int flags = 0; 1683 u32 itag = 0; 1684 struct rtable *rth; 1685 int err = -EINVAL; 1686 struct net *net = dev_net(dev); 1687 bool do_cache; 1688 1689 /* IP on this device is disabled. */ 1690 1691 if (!in_dev) 1692 goto out; 1693 1694 /* Check for the most weird martians, which can be not detected 1695 by fib_lookup. 1696 */ 1697 1698 tun_info = skb_tunnel_info(skb); 1699 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1700 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1701 else 1702 fl4.flowi4_tun_key.tun_id = 0; 1703 skb_dst_drop(skb); 1704 1705 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1706 goto martian_source; 1707 1708 res.fi = NULL; 1709 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1710 goto brd_input; 1711 1712 /* Accept zero addresses only to limited broadcast; 1713 * I even do not know to fix it or not. Waiting for complains :-) 1714 */ 1715 if (ipv4_is_zeronet(saddr)) 1716 goto martian_source; 1717 1718 if (ipv4_is_zeronet(daddr)) 1719 goto martian_destination; 1720 1721 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1722 * and call it once if daddr or/and saddr are loopback addresses 1723 */ 1724 if (ipv4_is_loopback(daddr)) { 1725 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1726 goto martian_destination; 1727 } else if (ipv4_is_loopback(saddr)) { 1728 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1729 goto martian_source; 1730 } 1731 1732 /* 1733 * Now we are ready to route packet. 1734 */ 1735 fl4.flowi4_oif = 0; 1736 fl4.flowi4_iif = vrf_master_ifindex_rcu(dev) ? : dev->ifindex; 1737 fl4.flowi4_mark = skb->mark; 1738 fl4.flowi4_tos = tos; 1739 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1740 fl4.flowi4_flags = 0; 1741 fl4.daddr = daddr; 1742 fl4.saddr = saddr; 1743 err = fib_lookup(net, &fl4, &res, 0); 1744 if (err != 0) { 1745 if (!IN_DEV_FORWARD(in_dev)) 1746 err = -EHOSTUNREACH; 1747 goto no_route; 1748 } 1749 1750 if (res.type == RTN_BROADCAST) 1751 goto brd_input; 1752 1753 if (res.type == RTN_LOCAL) { 1754 err = fib_validate_source(skb, saddr, daddr, tos, 1755 0, dev, in_dev, &itag); 1756 if (err < 0) 1757 goto martian_source_keep_err; 1758 goto local_input; 1759 } 1760 1761 if (!IN_DEV_FORWARD(in_dev)) { 1762 err = -EHOSTUNREACH; 1763 goto no_route; 1764 } 1765 if (res.type != RTN_UNICAST) 1766 goto martian_destination; 1767 1768 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 1769 out: return err; 1770 1771 brd_input: 1772 if (skb->protocol != htons(ETH_P_IP)) 1773 goto e_inval; 1774 1775 if (!ipv4_is_zeronet(saddr)) { 1776 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1777 in_dev, &itag); 1778 if (err < 0) 1779 goto martian_source_keep_err; 1780 } 1781 flags |= RTCF_BROADCAST; 1782 res.type = RTN_BROADCAST; 1783 RT_CACHE_STAT_INC(in_brd); 1784 1785 local_input: 1786 do_cache = false; 1787 if (res.fi) { 1788 if (!itag) { 1789 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); 1790 if (rt_cache_valid(rth)) { 1791 skb_dst_set_noref(skb, &rth->dst); 1792 err = 0; 1793 goto out; 1794 } 1795 do_cache = true; 1796 } 1797 } 1798 1799 rth = rt_dst_alloc(net->loopback_dev, 1800 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 1801 if (!rth) 1802 goto e_nobufs; 1803 1804 rth->dst.input= ip_local_deliver; 1805 rth->dst.output= ip_rt_bug; 1806 #ifdef CONFIG_IP_ROUTE_CLASSID 1807 rth->dst.tclassid = itag; 1808 #endif 1809 1810 rth->rt_genid = rt_genid_ipv4(net); 1811 rth->rt_flags = flags|RTCF_LOCAL; 1812 rth->rt_type = res.type; 1813 rth->rt_is_input = 1; 1814 rth->rt_iif = 0; 1815 rth->rt_pmtu = 0; 1816 rth->rt_gateway = 0; 1817 rth->rt_uses_gateway = 0; 1818 INIT_LIST_HEAD(&rth->rt_uncached); 1819 1820 RT_CACHE_STAT_INC(in_slow_tot); 1821 if (res.type == RTN_UNREACHABLE) { 1822 rth->dst.input= ip_error; 1823 rth->dst.error= -err; 1824 rth->rt_flags &= ~RTCF_LOCAL; 1825 } 1826 if (do_cache) { 1827 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) { 1828 rth->dst.flags |= DST_NOCACHE; 1829 rt_add_uncached_list(rth); 1830 } 1831 } 1832 skb_dst_set(skb, &rth->dst); 1833 err = 0; 1834 goto out; 1835 1836 no_route: 1837 RT_CACHE_STAT_INC(in_no_route); 1838 res.type = RTN_UNREACHABLE; 1839 res.fi = NULL; 1840 goto local_input; 1841 1842 /* 1843 * Do not cache martian addresses: they should be logged (RFC1812) 1844 */ 1845 martian_destination: 1846 RT_CACHE_STAT_INC(in_martian_dst); 1847 #ifdef CONFIG_IP_ROUTE_VERBOSE 1848 if (IN_DEV_LOG_MARTIANS(in_dev)) 1849 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 1850 &daddr, &saddr, dev->name); 1851 #endif 1852 1853 e_inval: 1854 err = -EINVAL; 1855 goto out; 1856 1857 e_nobufs: 1858 err = -ENOBUFS; 1859 goto out; 1860 1861 martian_source: 1862 err = -EINVAL; 1863 martian_source_keep_err: 1864 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 1865 goto out; 1866 } 1867 1868 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1869 u8 tos, struct net_device *dev) 1870 { 1871 int res; 1872 1873 rcu_read_lock(); 1874 1875 /* Multicast recognition logic is moved from route cache to here. 1876 The problem was that too many Ethernet cards have broken/missing 1877 hardware multicast filters :-( As result the host on multicasting 1878 network acquires a lot of useless route cache entries, sort of 1879 SDR messages from all the world. Now we try to get rid of them. 1880 Really, provided software IP multicast filter is organized 1881 reasonably (at least, hashed), it does not result in a slowdown 1882 comparing with route cache reject entries. 1883 Note, that multicast routers are not affected, because 1884 route cache entry is created eventually. 1885 */ 1886 if (ipv4_is_multicast(daddr)) { 1887 struct in_device *in_dev = __in_dev_get_rcu(dev); 1888 1889 if (in_dev) { 1890 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 1891 ip_hdr(skb)->protocol); 1892 if (our 1893 #ifdef CONFIG_IP_MROUTE 1894 || 1895 (!ipv4_is_local_multicast(daddr) && 1896 IN_DEV_MFORWARD(in_dev)) 1897 #endif 1898 ) { 1899 int res = ip_route_input_mc(skb, daddr, saddr, 1900 tos, dev, our); 1901 rcu_read_unlock(); 1902 return res; 1903 } 1904 } 1905 rcu_read_unlock(); 1906 return -EINVAL; 1907 } 1908 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 1909 rcu_read_unlock(); 1910 return res; 1911 } 1912 EXPORT_SYMBOL(ip_route_input_noref); 1913 1914 /* called with rcu_read_lock() */ 1915 static struct rtable *__mkroute_output(const struct fib_result *res, 1916 const struct flowi4 *fl4, int orig_oif, 1917 struct net_device *dev_out, 1918 unsigned int flags) 1919 { 1920 struct fib_info *fi = res->fi; 1921 struct fib_nh_exception *fnhe; 1922 struct in_device *in_dev; 1923 u16 type = res->type; 1924 struct rtable *rth; 1925 bool do_cache; 1926 1927 in_dev = __in_dev_get_rcu(dev_out); 1928 if (!in_dev) 1929 return ERR_PTR(-EINVAL); 1930 1931 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 1932 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 1933 return ERR_PTR(-EINVAL); 1934 1935 if (ipv4_is_lbcast(fl4->daddr)) 1936 type = RTN_BROADCAST; 1937 else if (ipv4_is_multicast(fl4->daddr)) 1938 type = RTN_MULTICAST; 1939 else if (ipv4_is_zeronet(fl4->daddr)) 1940 return ERR_PTR(-EINVAL); 1941 1942 if (dev_out->flags & IFF_LOOPBACK) 1943 flags |= RTCF_LOCAL; 1944 1945 do_cache = true; 1946 if (type == RTN_BROADCAST) { 1947 flags |= RTCF_BROADCAST | RTCF_LOCAL; 1948 fi = NULL; 1949 } else if (type == RTN_MULTICAST) { 1950 flags |= RTCF_MULTICAST | RTCF_LOCAL; 1951 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 1952 fl4->flowi4_proto)) 1953 flags &= ~RTCF_LOCAL; 1954 else 1955 do_cache = false; 1956 /* If multicast route do not exist use 1957 * default one, but do not gateway in this case. 1958 * Yes, it is hack. 1959 */ 1960 if (fi && res->prefixlen < 4) 1961 fi = NULL; 1962 } 1963 1964 fnhe = NULL; 1965 do_cache &= fi != NULL; 1966 if (do_cache) { 1967 struct rtable __rcu **prth; 1968 struct fib_nh *nh = &FIB_RES_NH(*res); 1969 1970 fnhe = find_exception(nh, fl4->daddr); 1971 if (fnhe) 1972 prth = &fnhe->fnhe_rth_output; 1973 else { 1974 if (unlikely(fl4->flowi4_flags & 1975 FLOWI_FLAG_KNOWN_NH && 1976 !(nh->nh_gw && 1977 nh->nh_scope == RT_SCOPE_LINK))) { 1978 do_cache = false; 1979 goto add; 1980 } 1981 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 1982 } 1983 rth = rcu_dereference(*prth); 1984 if (rt_cache_valid(rth)) { 1985 dst_hold(&rth->dst); 1986 return rth; 1987 } 1988 } 1989 1990 add: 1991 rth = rt_dst_alloc(dev_out, 1992 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1993 IN_DEV_CONF_GET(in_dev, NOXFRM), 1994 do_cache); 1995 if (!rth) 1996 return ERR_PTR(-ENOBUFS); 1997 1998 rth->dst.output = ip_output; 1999 2000 rth->rt_genid = rt_genid_ipv4(dev_net(dev_out)); 2001 rth->rt_flags = flags; 2002 rth->rt_type = type; 2003 rth->rt_is_input = 0; 2004 rth->rt_iif = orig_oif ? : 0; 2005 rth->rt_pmtu = 0; 2006 rth->rt_gateway = 0; 2007 rth->rt_uses_gateway = 0; 2008 INIT_LIST_HEAD(&rth->rt_uncached); 2009 RT_CACHE_STAT_INC(out_slow_tot); 2010 2011 if (flags & RTCF_LOCAL) 2012 rth->dst.input = ip_local_deliver; 2013 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2014 if (flags & RTCF_LOCAL && 2015 !(dev_out->flags & IFF_LOOPBACK)) { 2016 rth->dst.output = ip_mc_output; 2017 RT_CACHE_STAT_INC(out_slow_mc); 2018 } 2019 #ifdef CONFIG_IP_MROUTE 2020 if (type == RTN_MULTICAST) { 2021 if (IN_DEV_MFORWARD(in_dev) && 2022 !ipv4_is_local_multicast(fl4->daddr)) { 2023 rth->dst.input = ip_mr_input; 2024 rth->dst.output = ip_mc_output; 2025 } 2026 } 2027 #endif 2028 } 2029 2030 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0); 2031 if (lwtunnel_output_redirect(rth->dst.lwtstate)) 2032 rth->dst.output = lwtunnel_output; 2033 2034 return rth; 2035 } 2036 2037 /* 2038 * Major route resolver routine. 2039 */ 2040 2041 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) 2042 { 2043 struct net_device *dev_out = NULL; 2044 __u8 tos = RT_FL_TOS(fl4); 2045 unsigned int flags = 0; 2046 struct fib_result res; 2047 struct rtable *rth; 2048 int orig_oif; 2049 int err = -ENETUNREACH; 2050 2051 res.tclassid = 0; 2052 res.fi = NULL; 2053 res.table = NULL; 2054 2055 orig_oif = fl4->flowi4_oif; 2056 2057 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2058 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2059 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2060 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2061 2062 rcu_read_lock(); 2063 if (fl4->saddr) { 2064 rth = ERR_PTR(-EINVAL); 2065 if (ipv4_is_multicast(fl4->saddr) || 2066 ipv4_is_lbcast(fl4->saddr) || 2067 ipv4_is_zeronet(fl4->saddr)) 2068 goto out; 2069 2070 /* I removed check for oif == dev_out->oif here. 2071 It was wrong for two reasons: 2072 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2073 is assigned to multiple interfaces. 2074 2. Moreover, we are allowed to send packets with saddr 2075 of another iface. --ANK 2076 */ 2077 2078 if (fl4->flowi4_oif == 0 && 2079 (ipv4_is_multicast(fl4->daddr) || 2080 ipv4_is_lbcast(fl4->daddr))) { 2081 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2082 dev_out = __ip_dev_find(net, fl4->saddr, false); 2083 if (!dev_out) 2084 goto out; 2085 2086 /* Special hack: user can direct multicasts 2087 and limited broadcast via necessary interface 2088 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2089 This hack is not just for fun, it allows 2090 vic,vat and friends to work. 2091 They bind socket to loopback, set ttl to zero 2092 and expect that it will work. 2093 From the viewpoint of routing cache they are broken, 2094 because we are not allowed to build multicast path 2095 with loopback source addr (look, routing cache 2096 cannot know, that ttl is zero, so that packet 2097 will not leave this host and route is valid). 2098 Luckily, this hack is good workaround. 2099 */ 2100 2101 fl4->flowi4_oif = dev_out->ifindex; 2102 goto make_route; 2103 } 2104 2105 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2106 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2107 if (!__ip_dev_find(net, fl4->saddr, false)) 2108 goto out; 2109 } 2110 } 2111 2112 2113 if (fl4->flowi4_oif) { 2114 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2115 rth = ERR_PTR(-ENODEV); 2116 if (!dev_out) 2117 goto out; 2118 2119 /* RACE: Check return value of inet_select_addr instead. */ 2120 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2121 rth = ERR_PTR(-ENETUNREACH); 2122 goto out; 2123 } 2124 if (ipv4_is_local_multicast(fl4->daddr) || 2125 ipv4_is_lbcast(fl4->daddr) || 2126 fl4->flowi4_proto == IPPROTO_IGMP) { 2127 if (!fl4->saddr) 2128 fl4->saddr = inet_select_addr(dev_out, 0, 2129 RT_SCOPE_LINK); 2130 goto make_route; 2131 } 2132 if (!fl4->saddr) { 2133 if (ipv4_is_multicast(fl4->daddr)) 2134 fl4->saddr = inet_select_addr(dev_out, 0, 2135 fl4->flowi4_scope); 2136 else if (!fl4->daddr) 2137 fl4->saddr = inet_select_addr(dev_out, 0, 2138 RT_SCOPE_HOST); 2139 } 2140 if (netif_is_vrf(dev_out) && 2141 !(fl4->flowi4_flags & FLOWI_FLAG_VRFSRC)) { 2142 rth = vrf_dev_get_rth(dev_out); 2143 goto out; 2144 } 2145 } 2146 2147 if (!fl4->daddr) { 2148 fl4->daddr = fl4->saddr; 2149 if (!fl4->daddr) 2150 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2151 dev_out = net->loopback_dev; 2152 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2153 res.type = RTN_LOCAL; 2154 flags |= RTCF_LOCAL; 2155 goto make_route; 2156 } 2157 2158 err = fib_lookup(net, fl4, &res, 0); 2159 if (err) { 2160 res.fi = NULL; 2161 res.table = NULL; 2162 if (fl4->flowi4_oif) { 2163 /* Apparently, routing tables are wrong. Assume, 2164 that the destination is on link. 2165 2166 WHY? DW. 2167 Because we are allowed to send to iface 2168 even if it has NO routes and NO assigned 2169 addresses. When oif is specified, routing 2170 tables are looked up with only one purpose: 2171 to catch if destination is gatewayed, rather than 2172 direct. Moreover, if MSG_DONTROUTE is set, 2173 we send packet, ignoring both routing tables 2174 and ifaddr state. --ANK 2175 2176 2177 We could make it even if oif is unknown, 2178 likely IPv6, but we do not. 2179 */ 2180 2181 if (fl4->saddr == 0) 2182 fl4->saddr = inet_select_addr(dev_out, 0, 2183 RT_SCOPE_LINK); 2184 res.type = RTN_UNICAST; 2185 goto make_route; 2186 } 2187 rth = ERR_PTR(err); 2188 goto out; 2189 } 2190 2191 if (res.type == RTN_LOCAL) { 2192 if (!fl4->saddr) { 2193 if (res.fi->fib_prefsrc) 2194 fl4->saddr = res.fi->fib_prefsrc; 2195 else 2196 fl4->saddr = fl4->daddr; 2197 } 2198 dev_out = net->loopback_dev; 2199 fl4->flowi4_oif = dev_out->ifindex; 2200 flags |= RTCF_LOCAL; 2201 goto make_route; 2202 } 2203 2204 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2205 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2206 fib_select_multipath(&res); 2207 else 2208 #endif 2209 if (!res.prefixlen && 2210 res.table->tb_num_default > 1 && 2211 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2212 fib_select_default(fl4, &res); 2213 2214 if (!fl4->saddr) 2215 fl4->saddr = FIB_RES_PREFSRC(net, res); 2216 2217 dev_out = FIB_RES_DEV(res); 2218 fl4->flowi4_oif = dev_out->ifindex; 2219 2220 2221 make_route: 2222 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags); 2223 2224 out: 2225 rcu_read_unlock(); 2226 return rth; 2227 } 2228 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2229 2230 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2231 { 2232 return NULL; 2233 } 2234 2235 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2236 { 2237 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2238 2239 return mtu ? : dst->dev->mtu; 2240 } 2241 2242 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2243 struct sk_buff *skb, u32 mtu) 2244 { 2245 } 2246 2247 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2248 struct sk_buff *skb) 2249 { 2250 } 2251 2252 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2253 unsigned long old) 2254 { 2255 return NULL; 2256 } 2257 2258 static struct dst_ops ipv4_dst_blackhole_ops = { 2259 .family = AF_INET, 2260 .check = ipv4_blackhole_dst_check, 2261 .mtu = ipv4_blackhole_mtu, 2262 .default_advmss = ipv4_default_advmss, 2263 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2264 .redirect = ipv4_rt_blackhole_redirect, 2265 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2266 .neigh_lookup = ipv4_neigh_lookup, 2267 }; 2268 2269 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2270 { 2271 struct rtable *ort = (struct rtable *) dst_orig; 2272 struct rtable *rt; 2273 2274 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0); 2275 if (rt) { 2276 struct dst_entry *new = &rt->dst; 2277 2278 new->__use = 1; 2279 new->input = dst_discard; 2280 new->output = dst_discard_sk; 2281 2282 new->dev = ort->dst.dev; 2283 if (new->dev) 2284 dev_hold(new->dev); 2285 2286 rt->rt_is_input = ort->rt_is_input; 2287 rt->rt_iif = ort->rt_iif; 2288 rt->rt_pmtu = ort->rt_pmtu; 2289 2290 rt->rt_genid = rt_genid_ipv4(net); 2291 rt->rt_flags = ort->rt_flags; 2292 rt->rt_type = ort->rt_type; 2293 rt->rt_gateway = ort->rt_gateway; 2294 rt->rt_uses_gateway = ort->rt_uses_gateway; 2295 2296 INIT_LIST_HEAD(&rt->rt_uncached); 2297 dst_free(new); 2298 } 2299 2300 dst_release(dst_orig); 2301 2302 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2303 } 2304 2305 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2306 struct sock *sk) 2307 { 2308 struct rtable *rt = __ip_route_output_key(net, flp4); 2309 2310 if (IS_ERR(rt)) 2311 return rt; 2312 2313 if (flp4->flowi4_proto) 2314 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2315 flowi4_to_flowi(flp4), 2316 sk, 0); 2317 2318 return rt; 2319 } 2320 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2321 2322 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2323 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2324 u32 seq, int event, int nowait, unsigned int flags) 2325 { 2326 struct rtable *rt = skb_rtable(skb); 2327 struct rtmsg *r; 2328 struct nlmsghdr *nlh; 2329 unsigned long expires = 0; 2330 u32 error; 2331 u32 metrics[RTAX_MAX]; 2332 2333 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); 2334 if (!nlh) 2335 return -EMSGSIZE; 2336 2337 r = nlmsg_data(nlh); 2338 r->rtm_family = AF_INET; 2339 r->rtm_dst_len = 32; 2340 r->rtm_src_len = 0; 2341 r->rtm_tos = fl4->flowi4_tos; 2342 r->rtm_table = RT_TABLE_MAIN; 2343 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN)) 2344 goto nla_put_failure; 2345 r->rtm_type = rt->rt_type; 2346 r->rtm_scope = RT_SCOPE_UNIVERSE; 2347 r->rtm_protocol = RTPROT_UNSPEC; 2348 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2349 if (rt->rt_flags & RTCF_NOTIFY) 2350 r->rtm_flags |= RTM_F_NOTIFY; 2351 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2352 r->rtm_flags |= RTCF_DOREDIRECT; 2353 2354 if (nla_put_in_addr(skb, RTA_DST, dst)) 2355 goto nla_put_failure; 2356 if (src) { 2357 r->rtm_src_len = 32; 2358 if (nla_put_in_addr(skb, RTA_SRC, src)) 2359 goto nla_put_failure; 2360 } 2361 if (rt->dst.dev && 2362 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2363 goto nla_put_failure; 2364 #ifdef CONFIG_IP_ROUTE_CLASSID 2365 if (rt->dst.tclassid && 2366 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2367 goto nla_put_failure; 2368 #endif 2369 if (!rt_is_input_route(rt) && 2370 fl4->saddr != src) { 2371 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2372 goto nla_put_failure; 2373 } 2374 if (rt->rt_uses_gateway && 2375 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2376 goto nla_put_failure; 2377 2378 expires = rt->dst.expires; 2379 if (expires) { 2380 unsigned long now = jiffies; 2381 2382 if (time_before(now, expires)) 2383 expires -= now; 2384 else 2385 expires = 0; 2386 } 2387 2388 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2389 if (rt->rt_pmtu && expires) 2390 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2391 if (rtnetlink_put_metrics(skb, metrics) < 0) 2392 goto nla_put_failure; 2393 2394 if (fl4->flowi4_mark && 2395 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2396 goto nla_put_failure; 2397 2398 error = rt->dst.error; 2399 2400 if (rt_is_input_route(rt)) { 2401 #ifdef CONFIG_IP_MROUTE 2402 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2403 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2404 int err = ipmr_get_route(net, skb, 2405 fl4->saddr, fl4->daddr, 2406 r, nowait); 2407 if (err <= 0) { 2408 if (!nowait) { 2409 if (err == 0) 2410 return 0; 2411 goto nla_put_failure; 2412 } else { 2413 if (err == -EMSGSIZE) 2414 goto nla_put_failure; 2415 error = err; 2416 } 2417 } 2418 } else 2419 #endif 2420 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex)) 2421 goto nla_put_failure; 2422 } 2423 2424 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2425 goto nla_put_failure; 2426 2427 nlmsg_end(skb, nlh); 2428 return 0; 2429 2430 nla_put_failure: 2431 nlmsg_cancel(skb, nlh); 2432 return -EMSGSIZE; 2433 } 2434 2435 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 2436 { 2437 struct net *net = sock_net(in_skb->sk); 2438 struct rtmsg *rtm; 2439 struct nlattr *tb[RTA_MAX+1]; 2440 struct rtable *rt = NULL; 2441 struct flowi4 fl4; 2442 __be32 dst = 0; 2443 __be32 src = 0; 2444 u32 iif; 2445 int err; 2446 int mark; 2447 struct sk_buff *skb; 2448 2449 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2450 if (err < 0) 2451 goto errout; 2452 2453 rtm = nlmsg_data(nlh); 2454 2455 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2456 if (!skb) { 2457 err = -ENOBUFS; 2458 goto errout; 2459 } 2460 2461 /* Reserve room for dummy headers, this skb can pass 2462 through good chunk of routing engine. 2463 */ 2464 skb_reset_mac_header(skb); 2465 skb_reset_network_header(skb); 2466 2467 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2468 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2469 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2470 2471 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2472 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2473 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2474 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2475 2476 memset(&fl4, 0, sizeof(fl4)); 2477 fl4.daddr = dst; 2478 fl4.saddr = src; 2479 fl4.flowi4_tos = rtm->rtm_tos; 2480 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2481 fl4.flowi4_mark = mark; 2482 2483 if (iif) { 2484 struct net_device *dev; 2485 2486 dev = __dev_get_by_index(net, iif); 2487 if (!dev) { 2488 err = -ENODEV; 2489 goto errout_free; 2490 } 2491 2492 skb->protocol = htons(ETH_P_IP); 2493 skb->dev = dev; 2494 skb->mark = mark; 2495 local_bh_disable(); 2496 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2497 local_bh_enable(); 2498 2499 rt = skb_rtable(skb); 2500 if (err == 0 && rt->dst.error) 2501 err = -rt->dst.error; 2502 } else { 2503 rt = ip_route_output_key(net, &fl4); 2504 2505 err = 0; 2506 if (IS_ERR(rt)) 2507 err = PTR_ERR(rt); 2508 } 2509 2510 if (err) 2511 goto errout_free; 2512 2513 skb_dst_set(skb, &rt->dst); 2514 if (rtm->rtm_flags & RTM_F_NOTIFY) 2515 rt->rt_flags |= RTCF_NOTIFY; 2516 2517 err = rt_fill_info(net, dst, src, &fl4, skb, 2518 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, 2519 RTM_NEWROUTE, 0, 0); 2520 if (err < 0) 2521 goto errout_free; 2522 2523 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2524 errout: 2525 return err; 2526 2527 errout_free: 2528 kfree_skb(skb); 2529 goto errout; 2530 } 2531 2532 void ip_rt_multicast_event(struct in_device *in_dev) 2533 { 2534 rt_cache_flush(dev_net(in_dev->dev)); 2535 } 2536 2537 #ifdef CONFIG_SYSCTL 2538 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 2539 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2540 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2541 static int ip_rt_gc_elasticity __read_mostly = 8; 2542 2543 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2544 void __user *buffer, 2545 size_t *lenp, loff_t *ppos) 2546 { 2547 struct net *net = (struct net *)__ctl->extra1; 2548 2549 if (write) { 2550 rt_cache_flush(net); 2551 fnhe_genid_bump(net); 2552 return 0; 2553 } 2554 2555 return -EINVAL; 2556 } 2557 2558 static struct ctl_table ipv4_route_table[] = { 2559 { 2560 .procname = "gc_thresh", 2561 .data = &ipv4_dst_ops.gc_thresh, 2562 .maxlen = sizeof(int), 2563 .mode = 0644, 2564 .proc_handler = proc_dointvec, 2565 }, 2566 { 2567 .procname = "max_size", 2568 .data = &ip_rt_max_size, 2569 .maxlen = sizeof(int), 2570 .mode = 0644, 2571 .proc_handler = proc_dointvec, 2572 }, 2573 { 2574 /* Deprecated. Use gc_min_interval_ms */ 2575 2576 .procname = "gc_min_interval", 2577 .data = &ip_rt_gc_min_interval, 2578 .maxlen = sizeof(int), 2579 .mode = 0644, 2580 .proc_handler = proc_dointvec_jiffies, 2581 }, 2582 { 2583 .procname = "gc_min_interval_ms", 2584 .data = &ip_rt_gc_min_interval, 2585 .maxlen = sizeof(int), 2586 .mode = 0644, 2587 .proc_handler = proc_dointvec_ms_jiffies, 2588 }, 2589 { 2590 .procname = "gc_timeout", 2591 .data = &ip_rt_gc_timeout, 2592 .maxlen = sizeof(int), 2593 .mode = 0644, 2594 .proc_handler = proc_dointvec_jiffies, 2595 }, 2596 { 2597 .procname = "gc_interval", 2598 .data = &ip_rt_gc_interval, 2599 .maxlen = sizeof(int), 2600 .mode = 0644, 2601 .proc_handler = proc_dointvec_jiffies, 2602 }, 2603 { 2604 .procname = "redirect_load", 2605 .data = &ip_rt_redirect_load, 2606 .maxlen = sizeof(int), 2607 .mode = 0644, 2608 .proc_handler = proc_dointvec, 2609 }, 2610 { 2611 .procname = "redirect_number", 2612 .data = &ip_rt_redirect_number, 2613 .maxlen = sizeof(int), 2614 .mode = 0644, 2615 .proc_handler = proc_dointvec, 2616 }, 2617 { 2618 .procname = "redirect_silence", 2619 .data = &ip_rt_redirect_silence, 2620 .maxlen = sizeof(int), 2621 .mode = 0644, 2622 .proc_handler = proc_dointvec, 2623 }, 2624 { 2625 .procname = "error_cost", 2626 .data = &ip_rt_error_cost, 2627 .maxlen = sizeof(int), 2628 .mode = 0644, 2629 .proc_handler = proc_dointvec, 2630 }, 2631 { 2632 .procname = "error_burst", 2633 .data = &ip_rt_error_burst, 2634 .maxlen = sizeof(int), 2635 .mode = 0644, 2636 .proc_handler = proc_dointvec, 2637 }, 2638 { 2639 .procname = "gc_elasticity", 2640 .data = &ip_rt_gc_elasticity, 2641 .maxlen = sizeof(int), 2642 .mode = 0644, 2643 .proc_handler = proc_dointvec, 2644 }, 2645 { 2646 .procname = "mtu_expires", 2647 .data = &ip_rt_mtu_expires, 2648 .maxlen = sizeof(int), 2649 .mode = 0644, 2650 .proc_handler = proc_dointvec_jiffies, 2651 }, 2652 { 2653 .procname = "min_pmtu", 2654 .data = &ip_rt_min_pmtu, 2655 .maxlen = sizeof(int), 2656 .mode = 0644, 2657 .proc_handler = proc_dointvec, 2658 }, 2659 { 2660 .procname = "min_adv_mss", 2661 .data = &ip_rt_min_advmss, 2662 .maxlen = sizeof(int), 2663 .mode = 0644, 2664 .proc_handler = proc_dointvec, 2665 }, 2666 { } 2667 }; 2668 2669 static struct ctl_table ipv4_route_flush_table[] = { 2670 { 2671 .procname = "flush", 2672 .maxlen = sizeof(int), 2673 .mode = 0200, 2674 .proc_handler = ipv4_sysctl_rtcache_flush, 2675 }, 2676 { }, 2677 }; 2678 2679 static __net_init int sysctl_route_net_init(struct net *net) 2680 { 2681 struct ctl_table *tbl; 2682 2683 tbl = ipv4_route_flush_table; 2684 if (!net_eq(net, &init_net)) { 2685 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 2686 if (!tbl) 2687 goto err_dup; 2688 2689 /* Don't export sysctls to unprivileged users */ 2690 if (net->user_ns != &init_user_ns) 2691 tbl[0].procname = NULL; 2692 } 2693 tbl[0].extra1 = net; 2694 2695 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 2696 if (!net->ipv4.route_hdr) 2697 goto err_reg; 2698 return 0; 2699 2700 err_reg: 2701 if (tbl != ipv4_route_flush_table) 2702 kfree(tbl); 2703 err_dup: 2704 return -ENOMEM; 2705 } 2706 2707 static __net_exit void sysctl_route_net_exit(struct net *net) 2708 { 2709 struct ctl_table *tbl; 2710 2711 tbl = net->ipv4.route_hdr->ctl_table_arg; 2712 unregister_net_sysctl_table(net->ipv4.route_hdr); 2713 BUG_ON(tbl == ipv4_route_flush_table); 2714 kfree(tbl); 2715 } 2716 2717 static __net_initdata struct pernet_operations sysctl_route_ops = { 2718 .init = sysctl_route_net_init, 2719 .exit = sysctl_route_net_exit, 2720 }; 2721 #endif 2722 2723 static __net_init int rt_genid_init(struct net *net) 2724 { 2725 atomic_set(&net->ipv4.rt_genid, 0); 2726 atomic_set(&net->fnhe_genid, 0); 2727 get_random_bytes(&net->ipv4.dev_addr_genid, 2728 sizeof(net->ipv4.dev_addr_genid)); 2729 return 0; 2730 } 2731 2732 static __net_initdata struct pernet_operations rt_genid_ops = { 2733 .init = rt_genid_init, 2734 }; 2735 2736 static int __net_init ipv4_inetpeer_init(struct net *net) 2737 { 2738 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 2739 2740 if (!bp) 2741 return -ENOMEM; 2742 inet_peer_base_init(bp); 2743 net->ipv4.peers = bp; 2744 return 0; 2745 } 2746 2747 static void __net_exit ipv4_inetpeer_exit(struct net *net) 2748 { 2749 struct inet_peer_base *bp = net->ipv4.peers; 2750 2751 net->ipv4.peers = NULL; 2752 inetpeer_invalidate_tree(bp); 2753 kfree(bp); 2754 } 2755 2756 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 2757 .init = ipv4_inetpeer_init, 2758 .exit = ipv4_inetpeer_exit, 2759 }; 2760 2761 #ifdef CONFIG_IP_ROUTE_CLASSID 2762 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 2763 #endif /* CONFIG_IP_ROUTE_CLASSID */ 2764 2765 int __init ip_rt_init(void) 2766 { 2767 int rc = 0; 2768 int cpu; 2769 2770 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL); 2771 if (!ip_idents) 2772 panic("IP: failed to allocate ip_idents\n"); 2773 2774 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 2775 2776 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 2777 if (!ip_tstamps) 2778 panic("IP: failed to allocate ip_tstamps\n"); 2779 2780 for_each_possible_cpu(cpu) { 2781 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 2782 2783 INIT_LIST_HEAD(&ul->head); 2784 spin_lock_init(&ul->lock); 2785 } 2786 #ifdef CONFIG_IP_ROUTE_CLASSID 2787 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 2788 if (!ip_rt_acct) 2789 panic("IP: failed to allocate ip_rt_acct\n"); 2790 #endif 2791 2792 ipv4_dst_ops.kmem_cachep = 2793 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 2794 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 2795 2796 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 2797 2798 if (dst_entries_init(&ipv4_dst_ops) < 0) 2799 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 2800 2801 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 2802 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 2803 2804 ipv4_dst_ops.gc_thresh = ~0; 2805 ip_rt_max_size = INT_MAX; 2806 2807 devinet_init(); 2808 ip_fib_init(); 2809 2810 if (ip_rt_proc_init()) 2811 pr_err("Unable to create route proc files\n"); 2812 #ifdef CONFIG_XFRM 2813 xfrm_init(); 2814 xfrm4_init(); 2815 #endif 2816 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 2817 2818 #ifdef CONFIG_SYSCTL 2819 register_pernet_subsys(&sysctl_route_ops); 2820 #endif 2821 register_pernet_subsys(&rt_genid_ops); 2822 register_pernet_subsys(&ipv4_inetpeer_ops); 2823 return rc; 2824 } 2825 2826 #ifdef CONFIG_SYSCTL 2827 /* 2828 * We really need to sanitize the damn ipv4 init order, then all 2829 * this nonsense will go away. 2830 */ 2831 void __init ip_static_sysctl_init(void) 2832 { 2833 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 2834 } 2835 #endif 2836