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 <linux/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 #endif 112 #include <net/secure_seq.h> 113 #include <net/ip_tunnels.h> 114 #include <net/l3mdev.h> 115 116 #include "fib_lookup.h" 117 118 #define RT_FL_TOS(oldflp4) \ 119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 120 121 #define RT_GC_TIMEOUT (300*HZ) 122 123 static int ip_rt_max_size; 124 static int ip_rt_redirect_number __read_mostly = 9; 125 static int ip_rt_redirect_load __read_mostly = HZ / 50; 126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 127 static int ip_rt_error_cost __read_mostly = HZ; 128 static int ip_rt_error_burst __read_mostly = 5 * HZ; 129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 130 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 131 static int ip_rt_min_advmss __read_mostly = 256; 132 133 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 134 135 /* 136 * Interface to generic destination cache. 137 */ 138 139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 141 static unsigned int ipv4_mtu(const struct dst_entry *dst); 142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 143 static void ipv4_link_failure(struct sk_buff *skb); 144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 145 struct sk_buff *skb, u32 mtu); 146 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 147 struct sk_buff *skb); 148 static void ipv4_dst_destroy(struct dst_entry *dst); 149 150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 151 { 152 WARN_ON(1); 153 return NULL; 154 } 155 156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 157 struct sk_buff *skb, 158 const void *daddr); 159 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 160 161 static struct dst_ops ipv4_dst_ops = { 162 .family = AF_INET, 163 .check = ipv4_dst_check, 164 .default_advmss = ipv4_default_advmss, 165 .mtu = ipv4_mtu, 166 .cow_metrics = ipv4_cow_metrics, 167 .destroy = ipv4_dst_destroy, 168 .negative_advice = ipv4_negative_advice, 169 .link_failure = ipv4_link_failure, 170 .update_pmtu = ip_rt_update_pmtu, 171 .redirect = ip_do_redirect, 172 .local_out = __ip_local_out, 173 .neigh_lookup = ipv4_neigh_lookup, 174 .confirm_neigh = ipv4_confirm_neigh, 175 }; 176 177 #define ECN_OR_COST(class) TC_PRIO_##class 178 179 const __u8 ip_tos2prio[16] = { 180 TC_PRIO_BESTEFFORT, 181 ECN_OR_COST(BESTEFFORT), 182 TC_PRIO_BESTEFFORT, 183 ECN_OR_COST(BESTEFFORT), 184 TC_PRIO_BULK, 185 ECN_OR_COST(BULK), 186 TC_PRIO_BULK, 187 ECN_OR_COST(BULK), 188 TC_PRIO_INTERACTIVE, 189 ECN_OR_COST(INTERACTIVE), 190 TC_PRIO_INTERACTIVE, 191 ECN_OR_COST(INTERACTIVE), 192 TC_PRIO_INTERACTIVE_BULK, 193 ECN_OR_COST(INTERACTIVE_BULK), 194 TC_PRIO_INTERACTIVE_BULK, 195 ECN_OR_COST(INTERACTIVE_BULK) 196 }; 197 EXPORT_SYMBOL(ip_tos2prio); 198 199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 200 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 201 202 #ifdef CONFIG_PROC_FS 203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 204 { 205 if (*pos) 206 return NULL; 207 return SEQ_START_TOKEN; 208 } 209 210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 211 { 212 ++*pos; 213 return NULL; 214 } 215 216 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 217 { 218 } 219 220 static int rt_cache_seq_show(struct seq_file *seq, void *v) 221 { 222 if (v == SEQ_START_TOKEN) 223 seq_printf(seq, "%-127s\n", 224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 226 "HHUptod\tSpecDst"); 227 return 0; 228 } 229 230 static const struct seq_operations rt_cache_seq_ops = { 231 .start = rt_cache_seq_start, 232 .next = rt_cache_seq_next, 233 .stop = rt_cache_seq_stop, 234 .show = rt_cache_seq_show, 235 }; 236 237 static int rt_cache_seq_open(struct inode *inode, struct file *file) 238 { 239 return seq_open(file, &rt_cache_seq_ops); 240 } 241 242 static const struct file_operations rt_cache_seq_fops = { 243 .open = rt_cache_seq_open, 244 .read = seq_read, 245 .llseek = seq_lseek, 246 .release = seq_release, 247 }; 248 249 250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 251 { 252 int cpu; 253 254 if (*pos == 0) 255 return SEQ_START_TOKEN; 256 257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 258 if (!cpu_possible(cpu)) 259 continue; 260 *pos = cpu+1; 261 return &per_cpu(rt_cache_stat, cpu); 262 } 263 return NULL; 264 } 265 266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 267 { 268 int cpu; 269 270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 271 if (!cpu_possible(cpu)) 272 continue; 273 *pos = cpu+1; 274 return &per_cpu(rt_cache_stat, cpu); 275 } 276 return NULL; 277 278 } 279 280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 281 { 282 283 } 284 285 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 286 { 287 struct rt_cache_stat *st = v; 288 289 if (v == SEQ_START_TOKEN) { 290 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 291 return 0; 292 } 293 294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 296 dst_entries_get_slow(&ipv4_dst_ops), 297 0, /* st->in_hit */ 298 st->in_slow_tot, 299 st->in_slow_mc, 300 st->in_no_route, 301 st->in_brd, 302 st->in_martian_dst, 303 st->in_martian_src, 304 305 0, /* st->out_hit */ 306 st->out_slow_tot, 307 st->out_slow_mc, 308 309 0, /* st->gc_total */ 310 0, /* st->gc_ignored */ 311 0, /* st->gc_goal_miss */ 312 0, /* st->gc_dst_overflow */ 313 0, /* st->in_hlist_search */ 314 0 /* st->out_hlist_search */ 315 ); 316 return 0; 317 } 318 319 static const struct seq_operations rt_cpu_seq_ops = { 320 .start = rt_cpu_seq_start, 321 .next = rt_cpu_seq_next, 322 .stop = rt_cpu_seq_stop, 323 .show = rt_cpu_seq_show, 324 }; 325 326 327 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 328 { 329 return seq_open(file, &rt_cpu_seq_ops); 330 } 331 332 static const struct file_operations rt_cpu_seq_fops = { 333 .open = rt_cpu_seq_open, 334 .read = seq_read, 335 .llseek = seq_lseek, 336 .release = seq_release, 337 }; 338 339 #ifdef CONFIG_IP_ROUTE_CLASSID 340 static int rt_acct_proc_show(struct seq_file *m, void *v) 341 { 342 struct ip_rt_acct *dst, *src; 343 unsigned int i, j; 344 345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 346 if (!dst) 347 return -ENOMEM; 348 349 for_each_possible_cpu(i) { 350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 351 for (j = 0; j < 256; j++) { 352 dst[j].o_bytes += src[j].o_bytes; 353 dst[j].o_packets += src[j].o_packets; 354 dst[j].i_bytes += src[j].i_bytes; 355 dst[j].i_packets += src[j].i_packets; 356 } 357 } 358 359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 360 kfree(dst); 361 return 0; 362 } 363 #endif 364 365 static int __net_init ip_rt_do_proc_init(struct net *net) 366 { 367 struct proc_dir_entry *pde; 368 369 pde = proc_create("rt_cache", 0444, net->proc_net, 370 &rt_cache_seq_fops); 371 if (!pde) 372 goto err1; 373 374 pde = proc_create("rt_cache", 0444, 375 net->proc_net_stat, &rt_cpu_seq_fops); 376 if (!pde) 377 goto err2; 378 379 #ifdef CONFIG_IP_ROUTE_CLASSID 380 pde = proc_create_single("rt_acct", 0, net->proc_net, 381 rt_acct_proc_show); 382 if (!pde) 383 goto err3; 384 #endif 385 return 0; 386 387 #ifdef CONFIG_IP_ROUTE_CLASSID 388 err3: 389 remove_proc_entry("rt_cache", net->proc_net_stat); 390 #endif 391 err2: 392 remove_proc_entry("rt_cache", net->proc_net); 393 err1: 394 return -ENOMEM; 395 } 396 397 static void __net_exit ip_rt_do_proc_exit(struct net *net) 398 { 399 remove_proc_entry("rt_cache", net->proc_net_stat); 400 remove_proc_entry("rt_cache", net->proc_net); 401 #ifdef CONFIG_IP_ROUTE_CLASSID 402 remove_proc_entry("rt_acct", net->proc_net); 403 #endif 404 } 405 406 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 407 .init = ip_rt_do_proc_init, 408 .exit = ip_rt_do_proc_exit, 409 }; 410 411 static int __init ip_rt_proc_init(void) 412 { 413 return register_pernet_subsys(&ip_rt_proc_ops); 414 } 415 416 #else 417 static inline int ip_rt_proc_init(void) 418 { 419 return 0; 420 } 421 #endif /* CONFIG_PROC_FS */ 422 423 static inline bool rt_is_expired(const struct rtable *rth) 424 { 425 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 426 } 427 428 void rt_cache_flush(struct net *net) 429 { 430 rt_genid_bump_ipv4(net); 431 } 432 433 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 434 struct sk_buff *skb, 435 const void *daddr) 436 { 437 struct net_device *dev = dst->dev; 438 const __be32 *pkey = daddr; 439 const struct rtable *rt; 440 struct neighbour *n; 441 442 rt = (const struct rtable *) dst; 443 if (rt->rt_gateway) 444 pkey = (const __be32 *) &rt->rt_gateway; 445 else if (skb) 446 pkey = &ip_hdr(skb)->daddr; 447 448 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 449 if (n) 450 return n; 451 return neigh_create(&arp_tbl, pkey, dev); 452 } 453 454 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 455 { 456 struct net_device *dev = dst->dev; 457 const __be32 *pkey = daddr; 458 const struct rtable *rt; 459 460 rt = (const struct rtable *)dst; 461 if (rt->rt_gateway) 462 pkey = (const __be32 *)&rt->rt_gateway; 463 else if (!daddr || 464 (rt->rt_flags & 465 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) 466 return; 467 468 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 469 } 470 471 #define IP_IDENTS_SZ 2048u 472 473 static atomic_t *ip_idents __read_mostly; 474 static u32 *ip_tstamps __read_mostly; 475 476 /* In order to protect privacy, we add a perturbation to identifiers 477 * if one generator is seldom used. This makes hard for an attacker 478 * to infer how many packets were sent between two points in time. 479 */ 480 u32 ip_idents_reserve(u32 hash, int segs) 481 { 482 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; 483 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; 484 u32 old = READ_ONCE(*p_tstamp); 485 u32 now = (u32)jiffies; 486 u32 new, delta = 0; 487 488 if (old != now && cmpxchg(p_tstamp, old, now) == old) 489 delta = prandom_u32_max(now - old); 490 491 /* Do not use atomic_add_return() as it makes UBSAN unhappy */ 492 do { 493 old = (u32)atomic_read(p_id); 494 new = old + delta + segs; 495 } while (atomic_cmpxchg(p_id, old, new) != old); 496 497 return new - segs; 498 } 499 EXPORT_SYMBOL(ip_idents_reserve); 500 501 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 502 { 503 static u32 ip_idents_hashrnd __read_mostly; 504 u32 hash, id; 505 506 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); 507 508 hash = jhash_3words((__force u32)iph->daddr, 509 (__force u32)iph->saddr, 510 iph->protocol ^ net_hash_mix(net), 511 ip_idents_hashrnd); 512 id = ip_idents_reserve(hash, segs); 513 iph->id = htons(id); 514 } 515 EXPORT_SYMBOL(__ip_select_ident); 516 517 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 518 const struct sock *sk, 519 const struct iphdr *iph, 520 int oif, u8 tos, 521 u8 prot, u32 mark, int flow_flags) 522 { 523 if (sk) { 524 const struct inet_sock *inet = inet_sk(sk); 525 526 oif = sk->sk_bound_dev_if; 527 mark = sk->sk_mark; 528 tos = RT_CONN_FLAGS(sk); 529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 530 } 531 flowi4_init_output(fl4, oif, mark, tos, 532 RT_SCOPE_UNIVERSE, prot, 533 flow_flags, 534 iph->daddr, iph->saddr, 0, 0, 535 sock_net_uid(net, sk)); 536 } 537 538 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 539 const struct sock *sk) 540 { 541 const struct net *net = dev_net(skb->dev); 542 const struct iphdr *iph = ip_hdr(skb); 543 int oif = skb->dev->ifindex; 544 u8 tos = RT_TOS(iph->tos); 545 u8 prot = iph->protocol; 546 u32 mark = skb->mark; 547 548 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 549 } 550 551 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 552 { 553 const struct inet_sock *inet = inet_sk(sk); 554 const struct ip_options_rcu *inet_opt; 555 __be32 daddr = inet->inet_daddr; 556 557 rcu_read_lock(); 558 inet_opt = rcu_dereference(inet->inet_opt); 559 if (inet_opt && inet_opt->opt.srr) 560 daddr = inet_opt->opt.faddr; 561 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 562 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 563 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 564 inet_sk_flowi_flags(sk), 565 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 566 rcu_read_unlock(); 567 } 568 569 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 570 const struct sk_buff *skb) 571 { 572 if (skb) 573 build_skb_flow_key(fl4, skb, sk); 574 else 575 build_sk_flow_key(fl4, sk); 576 } 577 578 static DEFINE_SPINLOCK(fnhe_lock); 579 580 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 581 { 582 struct rtable *rt; 583 584 rt = rcu_dereference(fnhe->fnhe_rth_input); 585 if (rt) { 586 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 587 dst_dev_put(&rt->dst); 588 dst_release(&rt->dst); 589 } 590 rt = rcu_dereference(fnhe->fnhe_rth_output); 591 if (rt) { 592 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 593 dst_dev_put(&rt->dst); 594 dst_release(&rt->dst); 595 } 596 } 597 598 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 599 { 600 struct fib_nh_exception *fnhe, *oldest; 601 602 oldest = rcu_dereference(hash->chain); 603 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 604 fnhe = rcu_dereference(fnhe->fnhe_next)) { 605 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 606 oldest = fnhe; 607 } 608 fnhe_flush_routes(oldest); 609 return oldest; 610 } 611 612 static inline u32 fnhe_hashfun(__be32 daddr) 613 { 614 static u32 fnhe_hashrnd __read_mostly; 615 u32 hval; 616 617 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 618 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 619 return hash_32(hval, FNHE_HASH_SHIFT); 620 } 621 622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 623 { 624 rt->rt_pmtu = fnhe->fnhe_pmtu; 625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 626 rt->dst.expires = fnhe->fnhe_expires; 627 628 if (fnhe->fnhe_gw) { 629 rt->rt_flags |= RTCF_REDIRECTED; 630 rt->rt_gateway = fnhe->fnhe_gw; 631 rt->rt_uses_gateway = 1; 632 } 633 } 634 635 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 636 u32 pmtu, bool lock, unsigned long expires) 637 { 638 struct fnhe_hash_bucket *hash; 639 struct fib_nh_exception *fnhe; 640 struct rtable *rt; 641 u32 genid, hval; 642 unsigned int i; 643 int depth; 644 645 genid = fnhe_genid(dev_net(nh->nh_dev)); 646 hval = fnhe_hashfun(daddr); 647 648 spin_lock_bh(&fnhe_lock); 649 650 hash = rcu_dereference(nh->nh_exceptions); 651 if (!hash) { 652 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 653 if (!hash) 654 goto out_unlock; 655 rcu_assign_pointer(nh->nh_exceptions, hash); 656 } 657 658 hash += hval; 659 660 depth = 0; 661 for (fnhe = rcu_dereference(hash->chain); fnhe; 662 fnhe = rcu_dereference(fnhe->fnhe_next)) { 663 if (fnhe->fnhe_daddr == daddr) 664 break; 665 depth++; 666 } 667 668 if (fnhe) { 669 if (fnhe->fnhe_genid != genid) 670 fnhe->fnhe_genid = genid; 671 if (gw) 672 fnhe->fnhe_gw = gw; 673 if (pmtu) { 674 fnhe->fnhe_pmtu = pmtu; 675 fnhe->fnhe_mtu_locked = lock; 676 } 677 fnhe->fnhe_expires = max(1UL, expires); 678 /* Update all cached dsts too */ 679 rt = rcu_dereference(fnhe->fnhe_rth_input); 680 if (rt) 681 fill_route_from_fnhe(rt, fnhe); 682 rt = rcu_dereference(fnhe->fnhe_rth_output); 683 if (rt) 684 fill_route_from_fnhe(rt, fnhe); 685 } else { 686 if (depth > FNHE_RECLAIM_DEPTH) 687 fnhe = fnhe_oldest(hash); 688 else { 689 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 690 if (!fnhe) 691 goto out_unlock; 692 693 fnhe->fnhe_next = hash->chain; 694 rcu_assign_pointer(hash->chain, fnhe); 695 } 696 fnhe->fnhe_genid = genid; 697 fnhe->fnhe_daddr = daddr; 698 fnhe->fnhe_gw = gw; 699 fnhe->fnhe_pmtu = pmtu; 700 fnhe->fnhe_mtu_locked = lock; 701 fnhe->fnhe_expires = max(1UL, expires); 702 703 /* Exception created; mark the cached routes for the nexthop 704 * stale, so anyone caching it rechecks if this exception 705 * applies to them. 706 */ 707 rt = rcu_dereference(nh->nh_rth_input); 708 if (rt) 709 rt->dst.obsolete = DST_OBSOLETE_KILL; 710 711 for_each_possible_cpu(i) { 712 struct rtable __rcu **prt; 713 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 714 rt = rcu_dereference(*prt); 715 if (rt) 716 rt->dst.obsolete = DST_OBSOLETE_KILL; 717 } 718 } 719 720 fnhe->fnhe_stamp = jiffies; 721 722 out_unlock: 723 spin_unlock_bh(&fnhe_lock); 724 } 725 726 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 727 bool kill_route) 728 { 729 __be32 new_gw = icmp_hdr(skb)->un.gateway; 730 __be32 old_gw = ip_hdr(skb)->saddr; 731 struct net_device *dev = skb->dev; 732 struct in_device *in_dev; 733 struct fib_result res; 734 struct neighbour *n; 735 struct net *net; 736 737 switch (icmp_hdr(skb)->code & 7) { 738 case ICMP_REDIR_NET: 739 case ICMP_REDIR_NETTOS: 740 case ICMP_REDIR_HOST: 741 case ICMP_REDIR_HOSTTOS: 742 break; 743 744 default: 745 return; 746 } 747 748 if (rt->rt_gateway != old_gw) 749 return; 750 751 in_dev = __in_dev_get_rcu(dev); 752 if (!in_dev) 753 return; 754 755 net = dev_net(dev); 756 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 757 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 758 ipv4_is_zeronet(new_gw)) 759 goto reject_redirect; 760 761 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 762 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 763 goto reject_redirect; 764 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 765 goto reject_redirect; 766 } else { 767 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 768 goto reject_redirect; 769 } 770 771 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 772 if (!n) 773 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 774 if (!IS_ERR(n)) { 775 if (!(n->nud_state & NUD_VALID)) { 776 neigh_event_send(n, NULL); 777 } else { 778 if (fib_lookup(net, fl4, &res, 0) == 0) { 779 struct fib_nh *nh = &FIB_RES_NH(res); 780 781 update_or_create_fnhe(nh, fl4->daddr, new_gw, 782 0, false, 783 jiffies + ip_rt_gc_timeout); 784 } 785 if (kill_route) 786 rt->dst.obsolete = DST_OBSOLETE_KILL; 787 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 788 } 789 neigh_release(n); 790 } 791 return; 792 793 reject_redirect: 794 #ifdef CONFIG_IP_ROUTE_VERBOSE 795 if (IN_DEV_LOG_MARTIANS(in_dev)) { 796 const struct iphdr *iph = (const struct iphdr *) skb->data; 797 __be32 daddr = iph->daddr; 798 __be32 saddr = iph->saddr; 799 800 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 801 " Advised path = %pI4 -> %pI4\n", 802 &old_gw, dev->name, &new_gw, 803 &saddr, &daddr); 804 } 805 #endif 806 ; 807 } 808 809 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 810 { 811 struct rtable *rt; 812 struct flowi4 fl4; 813 const struct iphdr *iph = (const struct iphdr *) skb->data; 814 struct net *net = dev_net(skb->dev); 815 int oif = skb->dev->ifindex; 816 u8 tos = RT_TOS(iph->tos); 817 u8 prot = iph->protocol; 818 u32 mark = skb->mark; 819 820 rt = (struct rtable *) dst; 821 822 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 823 __ip_do_redirect(rt, skb, &fl4, true); 824 } 825 826 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 827 { 828 struct rtable *rt = (struct rtable *)dst; 829 struct dst_entry *ret = dst; 830 831 if (rt) { 832 if (dst->obsolete > 0) { 833 ip_rt_put(rt); 834 ret = NULL; 835 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 836 rt->dst.expires) { 837 ip_rt_put(rt); 838 ret = NULL; 839 } 840 } 841 return ret; 842 } 843 844 /* 845 * Algorithm: 846 * 1. The first ip_rt_redirect_number redirects are sent 847 * with exponential backoff, then we stop sending them at all, 848 * assuming that the host ignores our redirects. 849 * 2. If we did not see packets requiring redirects 850 * during ip_rt_redirect_silence, we assume that the host 851 * forgot redirected route and start to send redirects again. 852 * 853 * This algorithm is much cheaper and more intelligent than dumb load limiting 854 * in icmp.c. 855 * 856 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 857 * and "frag. need" (breaks PMTU discovery) in icmp.c. 858 */ 859 860 void ip_rt_send_redirect(struct sk_buff *skb) 861 { 862 struct rtable *rt = skb_rtable(skb); 863 struct in_device *in_dev; 864 struct inet_peer *peer; 865 struct net *net; 866 int log_martians; 867 int vif; 868 869 rcu_read_lock(); 870 in_dev = __in_dev_get_rcu(rt->dst.dev); 871 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 872 rcu_read_unlock(); 873 return; 874 } 875 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 876 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 877 rcu_read_unlock(); 878 879 net = dev_net(rt->dst.dev); 880 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 881 if (!peer) { 882 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 883 rt_nexthop(rt, ip_hdr(skb)->daddr)); 884 return; 885 } 886 887 /* No redirected packets during ip_rt_redirect_silence; 888 * reset the algorithm. 889 */ 890 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 891 peer->rate_tokens = 0; 892 peer->n_redirects = 0; 893 } 894 895 /* Too many ignored redirects; do not send anything 896 * set dst.rate_last to the last seen redirected packet. 897 */ 898 if (peer->n_redirects >= ip_rt_redirect_number) { 899 peer->rate_last = jiffies; 900 goto out_put_peer; 901 } 902 903 /* Check for load limit; set rate_last to the latest sent 904 * redirect. 905 */ 906 if (peer->rate_tokens == 0 || 907 time_after(jiffies, 908 (peer->rate_last + 909 (ip_rt_redirect_load << peer->rate_tokens)))) { 910 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 911 912 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 913 peer->rate_last = jiffies; 914 ++peer->rate_tokens; 915 ++peer->n_redirects; 916 #ifdef CONFIG_IP_ROUTE_VERBOSE 917 if (log_martians && 918 peer->rate_tokens == ip_rt_redirect_number) 919 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 920 &ip_hdr(skb)->saddr, inet_iif(skb), 921 &ip_hdr(skb)->daddr, &gw); 922 #endif 923 } 924 out_put_peer: 925 inet_putpeer(peer); 926 } 927 928 static int ip_error(struct sk_buff *skb) 929 { 930 struct rtable *rt = skb_rtable(skb); 931 struct net_device *dev = skb->dev; 932 struct in_device *in_dev; 933 struct inet_peer *peer; 934 unsigned long now; 935 struct net *net; 936 bool send; 937 int code; 938 939 if (netif_is_l3_master(skb->dev)) { 940 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 941 if (!dev) 942 goto out; 943 } 944 945 in_dev = __in_dev_get_rcu(dev); 946 947 /* IP on this device is disabled. */ 948 if (!in_dev) 949 goto out; 950 951 net = dev_net(rt->dst.dev); 952 if (!IN_DEV_FORWARD(in_dev)) { 953 switch (rt->dst.error) { 954 case EHOSTUNREACH: 955 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 956 break; 957 958 case ENETUNREACH: 959 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 960 break; 961 } 962 goto out; 963 } 964 965 switch (rt->dst.error) { 966 case EINVAL: 967 default: 968 goto out; 969 case EHOSTUNREACH: 970 code = ICMP_HOST_UNREACH; 971 break; 972 case ENETUNREACH: 973 code = ICMP_NET_UNREACH; 974 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 975 break; 976 case EACCES: 977 code = ICMP_PKT_FILTERED; 978 break; 979 } 980 981 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 982 l3mdev_master_ifindex(skb->dev), 1); 983 984 send = true; 985 if (peer) { 986 now = jiffies; 987 peer->rate_tokens += now - peer->rate_last; 988 if (peer->rate_tokens > ip_rt_error_burst) 989 peer->rate_tokens = ip_rt_error_burst; 990 peer->rate_last = now; 991 if (peer->rate_tokens >= ip_rt_error_cost) 992 peer->rate_tokens -= ip_rt_error_cost; 993 else 994 send = false; 995 inet_putpeer(peer); 996 } 997 if (send) 998 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 999 1000 out: kfree_skb(skb); 1001 return 0; 1002 } 1003 1004 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1005 { 1006 struct dst_entry *dst = &rt->dst; 1007 u32 old_mtu = ipv4_mtu(dst); 1008 struct fib_result res; 1009 bool lock = false; 1010 1011 if (ip_mtu_locked(dst)) 1012 return; 1013 1014 if (old_mtu < mtu) 1015 return; 1016 1017 if (mtu < ip_rt_min_pmtu) { 1018 lock = true; 1019 mtu = min(old_mtu, ip_rt_min_pmtu); 1020 } 1021 1022 if (rt->rt_pmtu == mtu && !lock && 1023 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 1024 return; 1025 1026 rcu_read_lock(); 1027 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) { 1028 struct fib_nh *nh = &FIB_RES_NH(res); 1029 1030 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock, 1031 jiffies + ip_rt_mtu_expires); 1032 } 1033 rcu_read_unlock(); 1034 } 1035 1036 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1037 struct sk_buff *skb, u32 mtu) 1038 { 1039 struct rtable *rt = (struct rtable *) dst; 1040 struct flowi4 fl4; 1041 1042 ip_rt_build_flow_key(&fl4, sk, skb); 1043 __ip_rt_update_pmtu(rt, &fl4, mtu); 1044 } 1045 1046 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1047 int oif, u8 protocol) 1048 { 1049 const struct iphdr *iph = (const struct iphdr *) skb->data; 1050 struct flowi4 fl4; 1051 struct rtable *rt; 1052 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1053 1054 __build_flow_key(net, &fl4, NULL, iph, oif, 1055 RT_TOS(iph->tos), protocol, mark, 0); 1056 rt = __ip_route_output_key(net, &fl4); 1057 if (!IS_ERR(rt)) { 1058 __ip_rt_update_pmtu(rt, &fl4, mtu); 1059 ip_rt_put(rt); 1060 } 1061 } 1062 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1063 1064 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1065 { 1066 const struct iphdr *iph = (const struct iphdr *) skb->data; 1067 struct flowi4 fl4; 1068 struct rtable *rt; 1069 1070 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1071 1072 if (!fl4.flowi4_mark) 1073 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1074 1075 rt = __ip_route_output_key(sock_net(sk), &fl4); 1076 if (!IS_ERR(rt)) { 1077 __ip_rt_update_pmtu(rt, &fl4, mtu); 1078 ip_rt_put(rt); 1079 } 1080 } 1081 1082 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1083 { 1084 const struct iphdr *iph = (const struct iphdr *) skb->data; 1085 struct flowi4 fl4; 1086 struct rtable *rt; 1087 struct dst_entry *odst = NULL; 1088 bool new = false; 1089 struct net *net = sock_net(sk); 1090 1091 bh_lock_sock(sk); 1092 1093 if (!ip_sk_accept_pmtu(sk)) 1094 goto out; 1095 1096 odst = sk_dst_get(sk); 1097 1098 if (sock_owned_by_user(sk) || !odst) { 1099 __ipv4_sk_update_pmtu(skb, sk, mtu); 1100 goto out; 1101 } 1102 1103 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1104 1105 rt = (struct rtable *)odst; 1106 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1107 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1108 if (IS_ERR(rt)) 1109 goto out; 1110 1111 new = true; 1112 } 1113 1114 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu); 1115 1116 if (!dst_check(&rt->dst, 0)) { 1117 if (new) 1118 dst_release(&rt->dst); 1119 1120 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1121 if (IS_ERR(rt)) 1122 goto out; 1123 1124 new = true; 1125 } 1126 1127 if (new) 1128 sk_dst_set(sk, &rt->dst); 1129 1130 out: 1131 bh_unlock_sock(sk); 1132 dst_release(odst); 1133 } 1134 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1135 1136 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1137 int oif, u8 protocol) 1138 { 1139 const struct iphdr *iph = (const struct iphdr *) skb->data; 1140 struct flowi4 fl4; 1141 struct rtable *rt; 1142 1143 __build_flow_key(net, &fl4, NULL, iph, oif, 1144 RT_TOS(iph->tos), protocol, 0, 0); 1145 rt = __ip_route_output_key(net, &fl4); 1146 if (!IS_ERR(rt)) { 1147 __ip_do_redirect(rt, skb, &fl4, false); 1148 ip_rt_put(rt); 1149 } 1150 } 1151 EXPORT_SYMBOL_GPL(ipv4_redirect); 1152 1153 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1154 { 1155 const struct iphdr *iph = (const struct iphdr *) skb->data; 1156 struct flowi4 fl4; 1157 struct rtable *rt; 1158 struct net *net = sock_net(sk); 1159 1160 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1161 rt = __ip_route_output_key(net, &fl4); 1162 if (!IS_ERR(rt)) { 1163 __ip_do_redirect(rt, skb, &fl4, false); 1164 ip_rt_put(rt); 1165 } 1166 } 1167 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1168 1169 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1170 { 1171 struct rtable *rt = (struct rtable *) dst; 1172 1173 /* All IPV4 dsts are created with ->obsolete set to the value 1174 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1175 * into this function always. 1176 * 1177 * When a PMTU/redirect information update invalidates a route, 1178 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1179 * DST_OBSOLETE_DEAD by dst_free(). 1180 */ 1181 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1182 return NULL; 1183 return dst; 1184 } 1185 1186 static void ipv4_link_failure(struct sk_buff *skb) 1187 { 1188 struct ip_options opt; 1189 struct rtable *rt; 1190 int res; 1191 1192 /* Recompile ip options since IPCB may not be valid anymore. 1193 */ 1194 memset(&opt, 0, sizeof(opt)); 1195 opt.optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr); 1196 1197 rcu_read_lock(); 1198 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1199 rcu_read_unlock(); 1200 1201 if (res) 1202 return; 1203 1204 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1205 1206 rt = skb_rtable(skb); 1207 if (rt) 1208 dst_set_expires(&rt->dst, 0); 1209 } 1210 1211 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1212 { 1213 pr_debug("%s: %pI4 -> %pI4, %s\n", 1214 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1215 skb->dev ? skb->dev->name : "?"); 1216 kfree_skb(skb); 1217 WARN_ON(1); 1218 return 0; 1219 } 1220 1221 /* 1222 We do not cache source address of outgoing interface, 1223 because it is used only by IP RR, TS and SRR options, 1224 so that it out of fast path. 1225 1226 BTW remember: "addr" is allowed to be not aligned 1227 in IP options! 1228 */ 1229 1230 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1231 { 1232 __be32 src; 1233 1234 if (rt_is_output_route(rt)) 1235 src = ip_hdr(skb)->saddr; 1236 else { 1237 struct fib_result res; 1238 struct iphdr *iph = ip_hdr(skb); 1239 struct flowi4 fl4 = { 1240 .daddr = iph->daddr, 1241 .saddr = iph->saddr, 1242 .flowi4_tos = RT_TOS(iph->tos), 1243 .flowi4_oif = rt->dst.dev->ifindex, 1244 .flowi4_iif = skb->dev->ifindex, 1245 .flowi4_mark = skb->mark, 1246 }; 1247 1248 rcu_read_lock(); 1249 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1250 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1251 else 1252 src = inet_select_addr(rt->dst.dev, 1253 rt_nexthop(rt, iph->daddr), 1254 RT_SCOPE_UNIVERSE); 1255 rcu_read_unlock(); 1256 } 1257 memcpy(addr, &src, 4); 1258 } 1259 1260 #ifdef CONFIG_IP_ROUTE_CLASSID 1261 static void set_class_tag(struct rtable *rt, u32 tag) 1262 { 1263 if (!(rt->dst.tclassid & 0xFFFF)) 1264 rt->dst.tclassid |= tag & 0xFFFF; 1265 if (!(rt->dst.tclassid & 0xFFFF0000)) 1266 rt->dst.tclassid |= tag & 0xFFFF0000; 1267 } 1268 #endif 1269 1270 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1271 { 1272 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1273 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1274 ip_rt_min_advmss); 1275 1276 return min(advmss, IPV4_MAX_PMTU - header_size); 1277 } 1278 1279 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1280 { 1281 const struct rtable *rt = (const struct rtable *) dst; 1282 unsigned int mtu = rt->rt_pmtu; 1283 1284 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1285 mtu = dst_metric_raw(dst, RTAX_MTU); 1286 1287 if (mtu) 1288 return mtu; 1289 1290 mtu = READ_ONCE(dst->dev->mtu); 1291 1292 if (unlikely(ip_mtu_locked(dst))) { 1293 if (rt->rt_uses_gateway && mtu > 576) 1294 mtu = 576; 1295 } 1296 1297 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1298 1299 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1300 } 1301 1302 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr) 1303 { 1304 struct fnhe_hash_bucket *hash; 1305 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1306 u32 hval = fnhe_hashfun(daddr); 1307 1308 spin_lock_bh(&fnhe_lock); 1309 1310 hash = rcu_dereference_protected(nh->nh_exceptions, 1311 lockdep_is_held(&fnhe_lock)); 1312 hash += hval; 1313 1314 fnhe_p = &hash->chain; 1315 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1316 while (fnhe) { 1317 if (fnhe->fnhe_daddr == daddr) { 1318 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1319 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1320 /* set fnhe_daddr to 0 to ensure it won't bind with 1321 * new dsts in rt_bind_exception(). 1322 */ 1323 fnhe->fnhe_daddr = 0; 1324 fnhe_flush_routes(fnhe); 1325 kfree_rcu(fnhe, rcu); 1326 break; 1327 } 1328 fnhe_p = &fnhe->fnhe_next; 1329 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1330 lockdep_is_held(&fnhe_lock)); 1331 } 1332 1333 spin_unlock_bh(&fnhe_lock); 1334 } 1335 1336 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1337 { 1338 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1339 struct fib_nh_exception *fnhe; 1340 u32 hval; 1341 1342 if (!hash) 1343 return NULL; 1344 1345 hval = fnhe_hashfun(daddr); 1346 1347 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1348 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1349 if (fnhe->fnhe_daddr == daddr) { 1350 if (fnhe->fnhe_expires && 1351 time_after(jiffies, fnhe->fnhe_expires)) { 1352 ip_del_fnhe(nh, daddr); 1353 break; 1354 } 1355 return fnhe; 1356 } 1357 } 1358 return NULL; 1359 } 1360 1361 /* MTU selection: 1362 * 1. mtu on route is locked - use it 1363 * 2. mtu from nexthop exception 1364 * 3. mtu from egress device 1365 */ 1366 1367 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1368 { 1369 struct fib_info *fi = res->fi; 1370 struct fib_nh *nh = &fi->fib_nh[res->nh_sel]; 1371 struct net_device *dev = nh->nh_dev; 1372 u32 mtu = 0; 1373 1374 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1375 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1376 mtu = fi->fib_mtu; 1377 1378 if (likely(!mtu)) { 1379 struct fib_nh_exception *fnhe; 1380 1381 fnhe = find_exception(nh, daddr); 1382 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1383 mtu = fnhe->fnhe_pmtu; 1384 } 1385 1386 if (likely(!mtu)) 1387 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1388 1389 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu); 1390 } 1391 1392 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1393 __be32 daddr, const bool do_cache) 1394 { 1395 bool ret = false; 1396 1397 spin_lock_bh(&fnhe_lock); 1398 1399 if (daddr == fnhe->fnhe_daddr) { 1400 struct rtable __rcu **porig; 1401 struct rtable *orig; 1402 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1403 1404 if (rt_is_input_route(rt)) 1405 porig = &fnhe->fnhe_rth_input; 1406 else 1407 porig = &fnhe->fnhe_rth_output; 1408 orig = rcu_dereference(*porig); 1409 1410 if (fnhe->fnhe_genid != genid) { 1411 fnhe->fnhe_genid = genid; 1412 fnhe->fnhe_gw = 0; 1413 fnhe->fnhe_pmtu = 0; 1414 fnhe->fnhe_expires = 0; 1415 fnhe->fnhe_mtu_locked = false; 1416 fnhe_flush_routes(fnhe); 1417 orig = NULL; 1418 } 1419 fill_route_from_fnhe(rt, fnhe); 1420 if (!rt->rt_gateway) 1421 rt->rt_gateway = daddr; 1422 1423 if (do_cache) { 1424 dst_hold(&rt->dst); 1425 rcu_assign_pointer(*porig, rt); 1426 if (orig) { 1427 dst_dev_put(&orig->dst); 1428 dst_release(&orig->dst); 1429 } 1430 ret = true; 1431 } 1432 1433 fnhe->fnhe_stamp = jiffies; 1434 } 1435 spin_unlock_bh(&fnhe_lock); 1436 1437 return ret; 1438 } 1439 1440 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1441 { 1442 struct rtable *orig, *prev, **p; 1443 bool ret = true; 1444 1445 if (rt_is_input_route(rt)) { 1446 p = (struct rtable **)&nh->nh_rth_input; 1447 } else { 1448 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1449 } 1450 orig = *p; 1451 1452 /* hold dst before doing cmpxchg() to avoid race condition 1453 * on this dst 1454 */ 1455 dst_hold(&rt->dst); 1456 prev = cmpxchg(p, orig, rt); 1457 if (prev == orig) { 1458 if (orig) { 1459 dst_dev_put(&orig->dst); 1460 dst_release(&orig->dst); 1461 } 1462 } else { 1463 dst_release(&rt->dst); 1464 ret = false; 1465 } 1466 1467 return ret; 1468 } 1469 1470 struct uncached_list { 1471 spinlock_t lock; 1472 struct list_head head; 1473 }; 1474 1475 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1476 1477 void rt_add_uncached_list(struct rtable *rt) 1478 { 1479 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1480 1481 rt->rt_uncached_list = ul; 1482 1483 spin_lock_bh(&ul->lock); 1484 list_add_tail(&rt->rt_uncached, &ul->head); 1485 spin_unlock_bh(&ul->lock); 1486 } 1487 1488 void rt_del_uncached_list(struct rtable *rt) 1489 { 1490 if (!list_empty(&rt->rt_uncached)) { 1491 struct uncached_list *ul = rt->rt_uncached_list; 1492 1493 spin_lock_bh(&ul->lock); 1494 list_del(&rt->rt_uncached); 1495 spin_unlock_bh(&ul->lock); 1496 } 1497 } 1498 1499 static void ipv4_dst_destroy(struct dst_entry *dst) 1500 { 1501 struct rtable *rt = (struct rtable *)dst; 1502 1503 ip_dst_metrics_put(dst); 1504 rt_del_uncached_list(rt); 1505 } 1506 1507 void rt_flush_dev(struct net_device *dev) 1508 { 1509 struct net *net = dev_net(dev); 1510 struct rtable *rt; 1511 int cpu; 1512 1513 for_each_possible_cpu(cpu) { 1514 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1515 1516 spin_lock_bh(&ul->lock); 1517 list_for_each_entry(rt, &ul->head, rt_uncached) { 1518 if (rt->dst.dev != dev) 1519 continue; 1520 rt->dst.dev = net->loopback_dev; 1521 dev_hold(rt->dst.dev); 1522 dev_put(dev); 1523 } 1524 spin_unlock_bh(&ul->lock); 1525 } 1526 } 1527 1528 static bool rt_cache_valid(const struct rtable *rt) 1529 { 1530 return rt && 1531 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1532 !rt_is_expired(rt); 1533 } 1534 1535 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1536 const struct fib_result *res, 1537 struct fib_nh_exception *fnhe, 1538 struct fib_info *fi, u16 type, u32 itag, 1539 const bool do_cache) 1540 { 1541 bool cached = false; 1542 1543 if (fi) { 1544 struct fib_nh *nh = &FIB_RES_NH(*res); 1545 1546 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1547 rt->rt_gateway = nh->nh_gw; 1548 rt->rt_uses_gateway = 1; 1549 } 1550 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1551 1552 #ifdef CONFIG_IP_ROUTE_CLASSID 1553 rt->dst.tclassid = nh->nh_tclassid; 1554 #endif 1555 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 1556 if (unlikely(fnhe)) 1557 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1558 else if (do_cache) 1559 cached = rt_cache_route(nh, rt); 1560 if (unlikely(!cached)) { 1561 /* Routes we intend to cache in nexthop exception or 1562 * FIB nexthop have the DST_NOCACHE bit clear. 1563 * However, if we are unsuccessful at storing this 1564 * route into the cache we really need to set it. 1565 */ 1566 if (!rt->rt_gateway) 1567 rt->rt_gateway = daddr; 1568 rt_add_uncached_list(rt); 1569 } 1570 } else 1571 rt_add_uncached_list(rt); 1572 1573 #ifdef CONFIG_IP_ROUTE_CLASSID 1574 #ifdef CONFIG_IP_MULTIPLE_TABLES 1575 set_class_tag(rt, res->tclassid); 1576 #endif 1577 set_class_tag(rt, itag); 1578 #endif 1579 } 1580 1581 struct rtable *rt_dst_alloc(struct net_device *dev, 1582 unsigned int flags, u16 type, 1583 bool nopolicy, bool noxfrm, bool will_cache) 1584 { 1585 struct rtable *rt; 1586 1587 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1588 (will_cache ? 0 : DST_HOST) | 1589 (nopolicy ? DST_NOPOLICY : 0) | 1590 (noxfrm ? DST_NOXFRM : 0)); 1591 1592 if (rt) { 1593 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1594 rt->rt_flags = flags; 1595 rt->rt_type = type; 1596 rt->rt_is_input = 0; 1597 rt->rt_iif = 0; 1598 rt->rt_pmtu = 0; 1599 rt->rt_mtu_locked = 0; 1600 rt->rt_gateway = 0; 1601 rt->rt_uses_gateway = 0; 1602 INIT_LIST_HEAD(&rt->rt_uncached); 1603 1604 rt->dst.output = ip_output; 1605 if (flags & RTCF_LOCAL) 1606 rt->dst.input = ip_local_deliver; 1607 } 1608 1609 return rt; 1610 } 1611 EXPORT_SYMBOL(rt_dst_alloc); 1612 1613 /* called in rcu_read_lock() section */ 1614 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1615 u8 tos, struct net_device *dev, 1616 struct in_device *in_dev, u32 *itag) 1617 { 1618 int err; 1619 1620 /* Primary sanity checks. */ 1621 if (!in_dev) 1622 return -EINVAL; 1623 1624 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1625 skb->protocol != htons(ETH_P_IP)) 1626 return -EINVAL; 1627 1628 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1629 return -EINVAL; 1630 1631 if (ipv4_is_zeronet(saddr)) { 1632 if (!ipv4_is_local_multicast(daddr) && 1633 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1634 return -EINVAL; 1635 } else { 1636 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1637 in_dev, itag); 1638 if (err < 0) 1639 return err; 1640 } 1641 return 0; 1642 } 1643 1644 /* called in rcu_read_lock() section */ 1645 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1646 u8 tos, struct net_device *dev, int our) 1647 { 1648 struct in_device *in_dev = __in_dev_get_rcu(dev); 1649 unsigned int flags = RTCF_MULTICAST; 1650 struct rtable *rth; 1651 u32 itag = 0; 1652 int err; 1653 1654 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1655 if (err) 1656 return err; 1657 1658 if (our) 1659 flags |= RTCF_LOCAL; 1660 1661 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1662 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1663 if (!rth) 1664 return -ENOBUFS; 1665 1666 #ifdef CONFIG_IP_ROUTE_CLASSID 1667 rth->dst.tclassid = itag; 1668 #endif 1669 rth->dst.output = ip_rt_bug; 1670 rth->rt_is_input= 1; 1671 1672 #ifdef CONFIG_IP_MROUTE 1673 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1674 rth->dst.input = ip_mr_input; 1675 #endif 1676 RT_CACHE_STAT_INC(in_slow_mc); 1677 1678 skb_dst_set(skb, &rth->dst); 1679 return 0; 1680 } 1681 1682 1683 static void ip_handle_martian_source(struct net_device *dev, 1684 struct in_device *in_dev, 1685 struct sk_buff *skb, 1686 __be32 daddr, 1687 __be32 saddr) 1688 { 1689 RT_CACHE_STAT_INC(in_martian_src); 1690 #ifdef CONFIG_IP_ROUTE_VERBOSE 1691 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1692 /* 1693 * RFC1812 recommendation, if source is martian, 1694 * the only hint is MAC header. 1695 */ 1696 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1697 &daddr, &saddr, dev->name); 1698 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1699 print_hex_dump(KERN_WARNING, "ll header: ", 1700 DUMP_PREFIX_OFFSET, 16, 1, 1701 skb_mac_header(skb), 1702 dev->hard_header_len, false); 1703 } 1704 } 1705 #endif 1706 } 1707 1708 /* called in rcu_read_lock() section */ 1709 static int __mkroute_input(struct sk_buff *skb, 1710 const struct fib_result *res, 1711 struct in_device *in_dev, 1712 __be32 daddr, __be32 saddr, u32 tos) 1713 { 1714 struct fib_nh_exception *fnhe; 1715 struct rtable *rth; 1716 int err; 1717 struct in_device *out_dev; 1718 bool do_cache; 1719 u32 itag = 0; 1720 1721 /* get a working reference to the output device */ 1722 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1723 if (!out_dev) { 1724 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1725 return -EINVAL; 1726 } 1727 1728 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1729 in_dev->dev, in_dev, &itag); 1730 if (err < 0) { 1731 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1732 saddr); 1733 1734 goto cleanup; 1735 } 1736 1737 do_cache = res->fi && !itag; 1738 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1739 skb->protocol == htons(ETH_P_IP) && 1740 (IN_DEV_SHARED_MEDIA(out_dev) || 1741 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1742 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1743 1744 if (skb->protocol != htons(ETH_P_IP)) { 1745 /* Not IP (i.e. ARP). Do not create route, if it is 1746 * invalid for proxy arp. DNAT routes are always valid. 1747 * 1748 * Proxy arp feature have been extended to allow, ARP 1749 * replies back to the same interface, to support 1750 * Private VLAN switch technologies. See arp.c. 1751 */ 1752 if (out_dev == in_dev && 1753 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1754 err = -EINVAL; 1755 goto cleanup; 1756 } 1757 } 1758 1759 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1760 if (do_cache) { 1761 if (fnhe) 1762 rth = rcu_dereference(fnhe->fnhe_rth_input); 1763 else 1764 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1765 if (rt_cache_valid(rth)) { 1766 skb_dst_set_noref(skb, &rth->dst); 1767 goto out; 1768 } 1769 } 1770 1771 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1772 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1773 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1774 if (!rth) { 1775 err = -ENOBUFS; 1776 goto cleanup; 1777 } 1778 1779 rth->rt_is_input = 1; 1780 RT_CACHE_STAT_INC(in_slow_tot); 1781 1782 rth->dst.input = ip_forward; 1783 1784 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1785 do_cache); 1786 lwtunnel_set_redirect(&rth->dst); 1787 skb_dst_set(skb, &rth->dst); 1788 out: 1789 err = 0; 1790 cleanup: 1791 return err; 1792 } 1793 1794 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1795 /* To make ICMP packets follow the right flow, the multipath hash is 1796 * calculated from the inner IP addresses. 1797 */ 1798 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1799 struct flow_keys *hash_keys) 1800 { 1801 const struct iphdr *outer_iph = ip_hdr(skb); 1802 const struct iphdr *key_iph = outer_iph; 1803 const struct iphdr *inner_iph; 1804 const struct icmphdr *icmph; 1805 struct iphdr _inner_iph; 1806 struct icmphdr _icmph; 1807 1808 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1809 goto out; 1810 1811 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1812 goto out; 1813 1814 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1815 &_icmph); 1816 if (!icmph) 1817 goto out; 1818 1819 if (icmph->type != ICMP_DEST_UNREACH && 1820 icmph->type != ICMP_REDIRECT && 1821 icmph->type != ICMP_TIME_EXCEEDED && 1822 icmph->type != ICMP_PARAMETERPROB) 1823 goto out; 1824 1825 inner_iph = skb_header_pointer(skb, 1826 outer_iph->ihl * 4 + sizeof(_icmph), 1827 sizeof(_inner_iph), &_inner_iph); 1828 if (!inner_iph) 1829 goto out; 1830 1831 key_iph = inner_iph; 1832 out: 1833 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1834 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1835 } 1836 1837 /* if skb is set it will be used and fl4 can be NULL */ 1838 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 1839 const struct sk_buff *skb, struct flow_keys *flkeys) 1840 { 1841 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 1842 struct flow_keys hash_keys; 1843 u32 mhash; 1844 1845 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 1846 case 0: 1847 memset(&hash_keys, 0, sizeof(hash_keys)); 1848 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1849 if (skb) { 1850 ip_multipath_l3_keys(skb, &hash_keys); 1851 } else { 1852 hash_keys.addrs.v4addrs.src = fl4->saddr; 1853 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1854 } 1855 break; 1856 case 1: 1857 /* skb is currently provided only when forwarding */ 1858 if (skb) { 1859 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 1860 struct flow_keys keys; 1861 1862 /* short-circuit if we already have L4 hash present */ 1863 if (skb->l4_hash) 1864 return skb_get_hash_raw(skb) >> 1; 1865 1866 memset(&hash_keys, 0, sizeof(hash_keys)); 1867 1868 if (!flkeys) { 1869 skb_flow_dissect_flow_keys(skb, &keys, flag); 1870 flkeys = &keys; 1871 } 1872 1873 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1874 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 1875 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 1876 hash_keys.ports.src = flkeys->ports.src; 1877 hash_keys.ports.dst = flkeys->ports.dst; 1878 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 1879 } else { 1880 memset(&hash_keys, 0, sizeof(hash_keys)); 1881 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1882 hash_keys.addrs.v4addrs.src = fl4->saddr; 1883 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1884 hash_keys.ports.src = fl4->fl4_sport; 1885 hash_keys.ports.dst = fl4->fl4_dport; 1886 hash_keys.basic.ip_proto = fl4->flowi4_proto; 1887 } 1888 break; 1889 } 1890 mhash = flow_hash_from_keys(&hash_keys); 1891 1892 if (multipath_hash) 1893 mhash = jhash_2words(mhash, multipath_hash, 0); 1894 1895 return mhash >> 1; 1896 } 1897 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1898 1899 static int ip_mkroute_input(struct sk_buff *skb, 1900 struct fib_result *res, 1901 struct in_device *in_dev, 1902 __be32 daddr, __be32 saddr, u32 tos, 1903 struct flow_keys *hkeys) 1904 { 1905 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1906 if (res->fi && res->fi->fib_nhs > 1) { 1907 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1908 1909 fib_select_multipath(res, h); 1910 } 1911 #endif 1912 1913 /* create a routing cache entry */ 1914 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1915 } 1916 1917 /* 1918 * NOTE. We drop all the packets that has local source 1919 * addresses, because every properly looped back packet 1920 * must have correct destination already attached by output routine. 1921 * 1922 * Such approach solves two big problems: 1923 * 1. Not simplex devices are handled properly. 1924 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1925 * called with rcu_read_lock() 1926 */ 1927 1928 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1929 u8 tos, struct net_device *dev, 1930 struct fib_result *res) 1931 { 1932 struct in_device *in_dev = __in_dev_get_rcu(dev); 1933 struct flow_keys *flkeys = NULL, _flkeys; 1934 struct net *net = dev_net(dev); 1935 struct ip_tunnel_info *tun_info; 1936 int err = -EINVAL; 1937 unsigned int flags = 0; 1938 u32 itag = 0; 1939 struct rtable *rth; 1940 struct flowi4 fl4; 1941 bool do_cache; 1942 1943 /* IP on this device is disabled. */ 1944 1945 if (!in_dev) 1946 goto out; 1947 1948 /* Check for the most weird martians, which can be not detected 1949 by fib_lookup. 1950 */ 1951 1952 tun_info = skb_tunnel_info(skb); 1953 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1954 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1955 else 1956 fl4.flowi4_tun_key.tun_id = 0; 1957 skb_dst_drop(skb); 1958 1959 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1960 goto martian_source; 1961 1962 res->fi = NULL; 1963 res->table = NULL; 1964 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1965 goto brd_input; 1966 1967 /* Accept zero addresses only to limited broadcast; 1968 * I even do not know to fix it or not. Waiting for complains :-) 1969 */ 1970 if (ipv4_is_zeronet(saddr)) 1971 goto martian_source; 1972 1973 if (ipv4_is_zeronet(daddr)) 1974 goto martian_destination; 1975 1976 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1977 * and call it once if daddr or/and saddr are loopback addresses 1978 */ 1979 if (ipv4_is_loopback(daddr)) { 1980 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1981 goto martian_destination; 1982 } else if (ipv4_is_loopback(saddr)) { 1983 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1984 goto martian_source; 1985 } 1986 1987 /* 1988 * Now we are ready to route packet. 1989 */ 1990 fl4.flowi4_oif = 0; 1991 fl4.flowi4_iif = dev->ifindex; 1992 fl4.flowi4_mark = skb->mark; 1993 fl4.flowi4_tos = tos; 1994 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1995 fl4.flowi4_flags = 0; 1996 fl4.daddr = daddr; 1997 fl4.saddr = saddr; 1998 fl4.flowi4_uid = sock_net_uid(net, NULL); 1999 2000 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2001 flkeys = &_flkeys; 2002 } else { 2003 fl4.flowi4_proto = 0; 2004 fl4.fl4_sport = 0; 2005 fl4.fl4_dport = 0; 2006 } 2007 2008 err = fib_lookup(net, &fl4, res, 0); 2009 if (err != 0) { 2010 if (!IN_DEV_FORWARD(in_dev)) 2011 err = -EHOSTUNREACH; 2012 goto no_route; 2013 } 2014 2015 if (res->type == RTN_BROADCAST) { 2016 if (IN_DEV_BFORWARD(in_dev)) 2017 goto make_route; 2018 goto brd_input; 2019 } 2020 2021 if (res->type == RTN_LOCAL) { 2022 err = fib_validate_source(skb, saddr, daddr, tos, 2023 0, dev, in_dev, &itag); 2024 if (err < 0) 2025 goto martian_source; 2026 goto local_input; 2027 } 2028 2029 if (!IN_DEV_FORWARD(in_dev)) { 2030 err = -EHOSTUNREACH; 2031 goto no_route; 2032 } 2033 if (res->type != RTN_UNICAST) 2034 goto martian_destination; 2035 2036 make_route: 2037 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2038 out: return err; 2039 2040 brd_input: 2041 if (skb->protocol != htons(ETH_P_IP)) 2042 goto e_inval; 2043 2044 if (!ipv4_is_zeronet(saddr)) { 2045 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2046 in_dev, &itag); 2047 if (err < 0) 2048 goto martian_source; 2049 } 2050 flags |= RTCF_BROADCAST; 2051 res->type = RTN_BROADCAST; 2052 RT_CACHE_STAT_INC(in_brd); 2053 2054 local_input: 2055 do_cache = false; 2056 if (res->fi) { 2057 if (!itag) { 2058 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 2059 if (rt_cache_valid(rth)) { 2060 skb_dst_set_noref(skb, &rth->dst); 2061 err = 0; 2062 goto out; 2063 } 2064 do_cache = true; 2065 } 2066 } 2067 2068 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2069 flags | RTCF_LOCAL, res->type, 2070 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2071 if (!rth) 2072 goto e_nobufs; 2073 2074 rth->dst.output= ip_rt_bug; 2075 #ifdef CONFIG_IP_ROUTE_CLASSID 2076 rth->dst.tclassid = itag; 2077 #endif 2078 rth->rt_is_input = 1; 2079 2080 RT_CACHE_STAT_INC(in_slow_tot); 2081 if (res->type == RTN_UNREACHABLE) { 2082 rth->dst.input= ip_error; 2083 rth->dst.error= -err; 2084 rth->rt_flags &= ~RTCF_LOCAL; 2085 } 2086 2087 if (do_cache) { 2088 struct fib_nh *nh = &FIB_RES_NH(*res); 2089 2090 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 2091 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2092 WARN_ON(rth->dst.input == lwtunnel_input); 2093 rth->dst.lwtstate->orig_input = rth->dst.input; 2094 rth->dst.input = lwtunnel_input; 2095 } 2096 2097 if (unlikely(!rt_cache_route(nh, rth))) 2098 rt_add_uncached_list(rth); 2099 } 2100 skb_dst_set(skb, &rth->dst); 2101 err = 0; 2102 goto out; 2103 2104 no_route: 2105 RT_CACHE_STAT_INC(in_no_route); 2106 res->type = RTN_UNREACHABLE; 2107 res->fi = NULL; 2108 res->table = NULL; 2109 goto local_input; 2110 2111 /* 2112 * Do not cache martian addresses: they should be logged (RFC1812) 2113 */ 2114 martian_destination: 2115 RT_CACHE_STAT_INC(in_martian_dst); 2116 #ifdef CONFIG_IP_ROUTE_VERBOSE 2117 if (IN_DEV_LOG_MARTIANS(in_dev)) 2118 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2119 &daddr, &saddr, dev->name); 2120 #endif 2121 2122 e_inval: 2123 err = -EINVAL; 2124 goto out; 2125 2126 e_nobufs: 2127 err = -ENOBUFS; 2128 goto out; 2129 2130 martian_source: 2131 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2132 goto out; 2133 } 2134 2135 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2136 u8 tos, struct net_device *dev) 2137 { 2138 struct fib_result res; 2139 int err; 2140 2141 tos &= IPTOS_RT_MASK; 2142 rcu_read_lock(); 2143 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2144 rcu_read_unlock(); 2145 2146 return err; 2147 } 2148 EXPORT_SYMBOL(ip_route_input_noref); 2149 2150 /* called with rcu_read_lock held */ 2151 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2152 u8 tos, struct net_device *dev, struct fib_result *res) 2153 { 2154 /* Multicast recognition logic is moved from route cache to here. 2155 The problem was that too many Ethernet cards have broken/missing 2156 hardware multicast filters :-( As result the host on multicasting 2157 network acquires a lot of useless route cache entries, sort of 2158 SDR messages from all the world. Now we try to get rid of them. 2159 Really, provided software IP multicast filter is organized 2160 reasonably (at least, hashed), it does not result in a slowdown 2161 comparing with route cache reject entries. 2162 Note, that multicast routers are not affected, because 2163 route cache entry is created eventually. 2164 */ 2165 if (ipv4_is_multicast(daddr)) { 2166 struct in_device *in_dev = __in_dev_get_rcu(dev); 2167 int our = 0; 2168 int err = -EINVAL; 2169 2170 if (!in_dev) 2171 return err; 2172 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2173 ip_hdr(skb)->protocol); 2174 2175 /* check l3 master if no match yet */ 2176 if (!our && netif_is_l3_slave(dev)) { 2177 struct in_device *l3_in_dev; 2178 2179 l3_in_dev = __in_dev_get_rcu(skb->dev); 2180 if (l3_in_dev) 2181 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2182 ip_hdr(skb)->protocol); 2183 } 2184 2185 if (our 2186 #ifdef CONFIG_IP_MROUTE 2187 || 2188 (!ipv4_is_local_multicast(daddr) && 2189 IN_DEV_MFORWARD(in_dev)) 2190 #endif 2191 ) { 2192 err = ip_route_input_mc(skb, daddr, saddr, 2193 tos, dev, our); 2194 } 2195 return err; 2196 } 2197 2198 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2199 } 2200 2201 /* called with rcu_read_lock() */ 2202 static struct rtable *__mkroute_output(const struct fib_result *res, 2203 const struct flowi4 *fl4, int orig_oif, 2204 struct net_device *dev_out, 2205 unsigned int flags) 2206 { 2207 struct fib_info *fi = res->fi; 2208 struct fib_nh_exception *fnhe; 2209 struct in_device *in_dev; 2210 u16 type = res->type; 2211 struct rtable *rth; 2212 bool do_cache; 2213 2214 in_dev = __in_dev_get_rcu(dev_out); 2215 if (!in_dev) 2216 return ERR_PTR(-EINVAL); 2217 2218 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2219 if (ipv4_is_loopback(fl4->saddr) && 2220 !(dev_out->flags & IFF_LOOPBACK) && 2221 !netif_is_l3_master(dev_out)) 2222 return ERR_PTR(-EINVAL); 2223 2224 if (ipv4_is_lbcast(fl4->daddr)) 2225 type = RTN_BROADCAST; 2226 else if (ipv4_is_multicast(fl4->daddr)) 2227 type = RTN_MULTICAST; 2228 else if (ipv4_is_zeronet(fl4->daddr)) 2229 return ERR_PTR(-EINVAL); 2230 2231 if (dev_out->flags & IFF_LOOPBACK) 2232 flags |= RTCF_LOCAL; 2233 2234 do_cache = true; 2235 if (type == RTN_BROADCAST) { 2236 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2237 fi = NULL; 2238 } else if (type == RTN_MULTICAST) { 2239 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2240 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2241 fl4->flowi4_proto)) 2242 flags &= ~RTCF_LOCAL; 2243 else 2244 do_cache = false; 2245 /* If multicast route do not exist use 2246 * default one, but do not gateway in this case. 2247 * Yes, it is hack. 2248 */ 2249 if (fi && res->prefixlen < 4) 2250 fi = NULL; 2251 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2252 (orig_oif != dev_out->ifindex)) { 2253 /* For local routes that require a particular output interface 2254 * we do not want to cache the result. Caching the result 2255 * causes incorrect behaviour when there are multiple source 2256 * addresses on the interface, the end result being that if the 2257 * intended recipient is waiting on that interface for the 2258 * packet he won't receive it because it will be delivered on 2259 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2260 * be set to the loopback interface as well. 2261 */ 2262 do_cache = false; 2263 } 2264 2265 fnhe = NULL; 2266 do_cache &= fi != NULL; 2267 if (fi) { 2268 struct rtable __rcu **prth; 2269 struct fib_nh *nh = &FIB_RES_NH(*res); 2270 2271 fnhe = find_exception(nh, fl4->daddr); 2272 if (!do_cache) 2273 goto add; 2274 if (fnhe) { 2275 prth = &fnhe->fnhe_rth_output; 2276 } else { 2277 if (unlikely(fl4->flowi4_flags & 2278 FLOWI_FLAG_KNOWN_NH && 2279 !(nh->nh_gw && 2280 nh->nh_scope == RT_SCOPE_LINK))) { 2281 do_cache = false; 2282 goto add; 2283 } 2284 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 2285 } 2286 rth = rcu_dereference(*prth); 2287 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2288 return rth; 2289 } 2290 2291 add: 2292 rth = rt_dst_alloc(dev_out, flags, type, 2293 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2294 IN_DEV_CONF_GET(in_dev, NOXFRM), 2295 do_cache); 2296 if (!rth) 2297 return ERR_PTR(-ENOBUFS); 2298 2299 rth->rt_iif = orig_oif; 2300 2301 RT_CACHE_STAT_INC(out_slow_tot); 2302 2303 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2304 if (flags & RTCF_LOCAL && 2305 !(dev_out->flags & IFF_LOOPBACK)) { 2306 rth->dst.output = ip_mc_output; 2307 RT_CACHE_STAT_INC(out_slow_mc); 2308 } 2309 #ifdef CONFIG_IP_MROUTE 2310 if (type == RTN_MULTICAST) { 2311 if (IN_DEV_MFORWARD(in_dev) && 2312 !ipv4_is_local_multicast(fl4->daddr)) { 2313 rth->dst.input = ip_mr_input; 2314 rth->dst.output = ip_mc_output; 2315 } 2316 } 2317 #endif 2318 } 2319 2320 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2321 lwtunnel_set_redirect(&rth->dst); 2322 2323 return rth; 2324 } 2325 2326 /* 2327 * Major route resolver routine. 2328 */ 2329 2330 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2331 const struct sk_buff *skb) 2332 { 2333 __u8 tos = RT_FL_TOS(fl4); 2334 struct fib_result res = { 2335 .type = RTN_UNSPEC, 2336 .fi = NULL, 2337 .table = NULL, 2338 .tclassid = 0, 2339 }; 2340 struct rtable *rth; 2341 2342 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2343 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2344 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2345 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2346 2347 rcu_read_lock(); 2348 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2349 rcu_read_unlock(); 2350 2351 return rth; 2352 } 2353 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2354 2355 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2356 struct fib_result *res, 2357 const struct sk_buff *skb) 2358 { 2359 struct net_device *dev_out = NULL; 2360 int orig_oif = fl4->flowi4_oif; 2361 unsigned int flags = 0; 2362 struct rtable *rth; 2363 int err = -ENETUNREACH; 2364 2365 if (fl4->saddr) { 2366 rth = ERR_PTR(-EINVAL); 2367 if (ipv4_is_multicast(fl4->saddr) || 2368 ipv4_is_lbcast(fl4->saddr) || 2369 ipv4_is_zeronet(fl4->saddr)) 2370 goto out; 2371 2372 /* I removed check for oif == dev_out->oif here. 2373 It was wrong for two reasons: 2374 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2375 is assigned to multiple interfaces. 2376 2. Moreover, we are allowed to send packets with saddr 2377 of another iface. --ANK 2378 */ 2379 2380 if (fl4->flowi4_oif == 0 && 2381 (ipv4_is_multicast(fl4->daddr) || 2382 ipv4_is_lbcast(fl4->daddr))) { 2383 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2384 dev_out = __ip_dev_find(net, fl4->saddr, false); 2385 if (!dev_out) 2386 goto out; 2387 2388 /* Special hack: user can direct multicasts 2389 and limited broadcast via necessary interface 2390 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2391 This hack is not just for fun, it allows 2392 vic,vat and friends to work. 2393 They bind socket to loopback, set ttl to zero 2394 and expect that it will work. 2395 From the viewpoint of routing cache they are broken, 2396 because we are not allowed to build multicast path 2397 with loopback source addr (look, routing cache 2398 cannot know, that ttl is zero, so that packet 2399 will not leave this host and route is valid). 2400 Luckily, this hack is good workaround. 2401 */ 2402 2403 fl4->flowi4_oif = dev_out->ifindex; 2404 goto make_route; 2405 } 2406 2407 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2408 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2409 if (!__ip_dev_find(net, fl4->saddr, false)) 2410 goto out; 2411 } 2412 } 2413 2414 2415 if (fl4->flowi4_oif) { 2416 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2417 rth = ERR_PTR(-ENODEV); 2418 if (!dev_out) 2419 goto out; 2420 2421 /* RACE: Check return value of inet_select_addr instead. */ 2422 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2423 rth = ERR_PTR(-ENETUNREACH); 2424 goto out; 2425 } 2426 if (ipv4_is_local_multicast(fl4->daddr) || 2427 ipv4_is_lbcast(fl4->daddr) || 2428 fl4->flowi4_proto == IPPROTO_IGMP) { 2429 if (!fl4->saddr) 2430 fl4->saddr = inet_select_addr(dev_out, 0, 2431 RT_SCOPE_LINK); 2432 goto make_route; 2433 } 2434 if (!fl4->saddr) { 2435 if (ipv4_is_multicast(fl4->daddr)) 2436 fl4->saddr = inet_select_addr(dev_out, 0, 2437 fl4->flowi4_scope); 2438 else if (!fl4->daddr) 2439 fl4->saddr = inet_select_addr(dev_out, 0, 2440 RT_SCOPE_HOST); 2441 } 2442 } 2443 2444 if (!fl4->daddr) { 2445 fl4->daddr = fl4->saddr; 2446 if (!fl4->daddr) 2447 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2448 dev_out = net->loopback_dev; 2449 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2450 res->type = RTN_LOCAL; 2451 flags |= RTCF_LOCAL; 2452 goto make_route; 2453 } 2454 2455 err = fib_lookup(net, fl4, res, 0); 2456 if (err) { 2457 res->fi = NULL; 2458 res->table = NULL; 2459 if (fl4->flowi4_oif && 2460 (ipv4_is_multicast(fl4->daddr) || 2461 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2462 /* Apparently, routing tables are wrong. Assume, 2463 that the destination is on link. 2464 2465 WHY? DW. 2466 Because we are allowed to send to iface 2467 even if it has NO routes and NO assigned 2468 addresses. When oif is specified, routing 2469 tables are looked up with only one purpose: 2470 to catch if destination is gatewayed, rather than 2471 direct. Moreover, if MSG_DONTROUTE is set, 2472 we send packet, ignoring both routing tables 2473 and ifaddr state. --ANK 2474 2475 2476 We could make it even if oif is unknown, 2477 likely IPv6, but we do not. 2478 */ 2479 2480 if (fl4->saddr == 0) 2481 fl4->saddr = inet_select_addr(dev_out, 0, 2482 RT_SCOPE_LINK); 2483 res->type = RTN_UNICAST; 2484 goto make_route; 2485 } 2486 rth = ERR_PTR(err); 2487 goto out; 2488 } 2489 2490 if (res->type == RTN_LOCAL) { 2491 if (!fl4->saddr) { 2492 if (res->fi->fib_prefsrc) 2493 fl4->saddr = res->fi->fib_prefsrc; 2494 else 2495 fl4->saddr = fl4->daddr; 2496 } 2497 2498 /* L3 master device is the loopback for that domain */ 2499 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2500 net->loopback_dev; 2501 2502 /* make sure orig_oif points to fib result device even 2503 * though packet rx/tx happens over loopback or l3mdev 2504 */ 2505 orig_oif = FIB_RES_OIF(*res); 2506 2507 fl4->flowi4_oif = dev_out->ifindex; 2508 flags |= RTCF_LOCAL; 2509 goto make_route; 2510 } 2511 2512 fib_select_path(net, res, fl4, skb); 2513 2514 dev_out = FIB_RES_DEV(*res); 2515 fl4->flowi4_oif = dev_out->ifindex; 2516 2517 2518 make_route: 2519 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2520 2521 out: 2522 return rth; 2523 } 2524 2525 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2526 { 2527 return NULL; 2528 } 2529 2530 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2531 { 2532 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2533 2534 return mtu ? : dst->dev->mtu; 2535 } 2536 2537 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2538 struct sk_buff *skb, u32 mtu) 2539 { 2540 } 2541 2542 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2543 struct sk_buff *skb) 2544 { 2545 } 2546 2547 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2548 unsigned long old) 2549 { 2550 return NULL; 2551 } 2552 2553 static struct dst_ops ipv4_dst_blackhole_ops = { 2554 .family = AF_INET, 2555 .check = ipv4_blackhole_dst_check, 2556 .mtu = ipv4_blackhole_mtu, 2557 .default_advmss = ipv4_default_advmss, 2558 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2559 .redirect = ipv4_rt_blackhole_redirect, 2560 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2561 .neigh_lookup = ipv4_neigh_lookup, 2562 }; 2563 2564 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2565 { 2566 struct rtable *ort = (struct rtable *) dst_orig; 2567 struct rtable *rt; 2568 2569 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2570 if (rt) { 2571 struct dst_entry *new = &rt->dst; 2572 2573 new->__use = 1; 2574 new->input = dst_discard; 2575 new->output = dst_discard_out; 2576 2577 new->dev = net->loopback_dev; 2578 if (new->dev) 2579 dev_hold(new->dev); 2580 2581 rt->rt_is_input = ort->rt_is_input; 2582 rt->rt_iif = ort->rt_iif; 2583 rt->rt_pmtu = ort->rt_pmtu; 2584 rt->rt_mtu_locked = ort->rt_mtu_locked; 2585 2586 rt->rt_genid = rt_genid_ipv4(net); 2587 rt->rt_flags = ort->rt_flags; 2588 rt->rt_type = ort->rt_type; 2589 rt->rt_gateway = ort->rt_gateway; 2590 rt->rt_uses_gateway = ort->rt_uses_gateway; 2591 2592 INIT_LIST_HEAD(&rt->rt_uncached); 2593 } 2594 2595 dst_release(dst_orig); 2596 2597 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2598 } 2599 2600 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2601 const struct sock *sk) 2602 { 2603 struct rtable *rt = __ip_route_output_key(net, flp4); 2604 2605 if (IS_ERR(rt)) 2606 return rt; 2607 2608 if (flp4->flowi4_proto) 2609 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2610 flowi4_to_flowi(flp4), 2611 sk, 0); 2612 2613 return rt; 2614 } 2615 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2616 2617 /* called with rcu_read_lock held */ 2618 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2619 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2620 struct sk_buff *skb, u32 portid, u32 seq) 2621 { 2622 struct rtmsg *r; 2623 struct nlmsghdr *nlh; 2624 unsigned long expires = 0; 2625 u32 error; 2626 u32 metrics[RTAX_MAX]; 2627 2628 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2629 if (!nlh) 2630 return -EMSGSIZE; 2631 2632 r = nlmsg_data(nlh); 2633 r->rtm_family = AF_INET; 2634 r->rtm_dst_len = 32; 2635 r->rtm_src_len = 0; 2636 r->rtm_tos = fl4->flowi4_tos; 2637 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2638 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2639 goto nla_put_failure; 2640 r->rtm_type = rt->rt_type; 2641 r->rtm_scope = RT_SCOPE_UNIVERSE; 2642 r->rtm_protocol = RTPROT_UNSPEC; 2643 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2644 if (rt->rt_flags & RTCF_NOTIFY) 2645 r->rtm_flags |= RTM_F_NOTIFY; 2646 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2647 r->rtm_flags |= RTCF_DOREDIRECT; 2648 2649 if (nla_put_in_addr(skb, RTA_DST, dst)) 2650 goto nla_put_failure; 2651 if (src) { 2652 r->rtm_src_len = 32; 2653 if (nla_put_in_addr(skb, RTA_SRC, src)) 2654 goto nla_put_failure; 2655 } 2656 if (rt->dst.dev && 2657 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2658 goto nla_put_failure; 2659 #ifdef CONFIG_IP_ROUTE_CLASSID 2660 if (rt->dst.tclassid && 2661 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2662 goto nla_put_failure; 2663 #endif 2664 if (!rt_is_input_route(rt) && 2665 fl4->saddr != src) { 2666 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2667 goto nla_put_failure; 2668 } 2669 if (rt->rt_uses_gateway && 2670 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2671 goto nla_put_failure; 2672 2673 expires = rt->dst.expires; 2674 if (expires) { 2675 unsigned long now = jiffies; 2676 2677 if (time_before(now, expires)) 2678 expires -= now; 2679 else 2680 expires = 0; 2681 } 2682 2683 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2684 if (rt->rt_pmtu && expires) 2685 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2686 if (rt->rt_mtu_locked && expires) 2687 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2688 if (rtnetlink_put_metrics(skb, metrics) < 0) 2689 goto nla_put_failure; 2690 2691 if (fl4->flowi4_mark && 2692 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2693 goto nla_put_failure; 2694 2695 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2696 nla_put_u32(skb, RTA_UID, 2697 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2698 goto nla_put_failure; 2699 2700 error = rt->dst.error; 2701 2702 if (rt_is_input_route(rt)) { 2703 #ifdef CONFIG_IP_MROUTE 2704 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2705 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2706 int err = ipmr_get_route(net, skb, 2707 fl4->saddr, fl4->daddr, 2708 r, portid); 2709 2710 if (err <= 0) { 2711 if (err == 0) 2712 return 0; 2713 goto nla_put_failure; 2714 } 2715 } else 2716 #endif 2717 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2718 goto nla_put_failure; 2719 } 2720 2721 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2722 goto nla_put_failure; 2723 2724 nlmsg_end(skb, nlh); 2725 return 0; 2726 2727 nla_put_failure: 2728 nlmsg_cancel(skb, nlh); 2729 return -EMSGSIZE; 2730 } 2731 2732 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2733 u8 ip_proto, __be16 sport, 2734 __be16 dport) 2735 { 2736 struct sk_buff *skb; 2737 struct iphdr *iph; 2738 2739 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2740 if (!skb) 2741 return NULL; 2742 2743 /* Reserve room for dummy headers, this skb can pass 2744 * through good chunk of routing engine. 2745 */ 2746 skb_reset_mac_header(skb); 2747 skb_reset_network_header(skb); 2748 skb->protocol = htons(ETH_P_IP); 2749 iph = skb_put(skb, sizeof(struct iphdr)); 2750 iph->protocol = ip_proto; 2751 iph->saddr = src; 2752 iph->daddr = dst; 2753 iph->version = 0x4; 2754 iph->frag_off = 0; 2755 iph->ihl = 0x5; 2756 skb_set_transport_header(skb, skb->len); 2757 2758 switch (iph->protocol) { 2759 case IPPROTO_UDP: { 2760 struct udphdr *udph; 2761 2762 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2763 udph->source = sport; 2764 udph->dest = dport; 2765 udph->len = sizeof(struct udphdr); 2766 udph->check = 0; 2767 break; 2768 } 2769 case IPPROTO_TCP: { 2770 struct tcphdr *tcph; 2771 2772 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2773 tcph->source = sport; 2774 tcph->dest = dport; 2775 tcph->doff = sizeof(struct tcphdr) / 4; 2776 tcph->rst = 1; 2777 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2778 src, dst, 0); 2779 break; 2780 } 2781 case IPPROTO_ICMP: { 2782 struct icmphdr *icmph; 2783 2784 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2785 icmph->type = ICMP_ECHO; 2786 icmph->code = 0; 2787 } 2788 } 2789 2790 return skb; 2791 } 2792 2793 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 2794 const struct nlmsghdr *nlh, 2795 struct nlattr **tb, 2796 struct netlink_ext_ack *extack) 2797 { 2798 struct rtmsg *rtm; 2799 int i, err; 2800 2801 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 2802 NL_SET_ERR_MSG(extack, 2803 "ipv4: Invalid header for route get request"); 2804 return -EINVAL; 2805 } 2806 2807 if (!netlink_strict_get_check(skb)) 2808 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, 2809 rtm_ipv4_policy, extack); 2810 2811 rtm = nlmsg_data(nlh); 2812 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 2813 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 2814 rtm->rtm_table || rtm->rtm_protocol || 2815 rtm->rtm_scope || rtm->rtm_type) { 2816 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 2817 return -EINVAL; 2818 } 2819 2820 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 2821 RTM_F_LOOKUP_TABLE | 2822 RTM_F_FIB_MATCH)) { 2823 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 2824 return -EINVAL; 2825 } 2826 2827 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 2828 rtm_ipv4_policy, extack); 2829 if (err) 2830 return err; 2831 2832 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 2833 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 2834 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 2835 return -EINVAL; 2836 } 2837 2838 for (i = 0; i <= RTA_MAX; i++) { 2839 if (!tb[i]) 2840 continue; 2841 2842 switch (i) { 2843 case RTA_IIF: 2844 case RTA_OIF: 2845 case RTA_SRC: 2846 case RTA_DST: 2847 case RTA_IP_PROTO: 2848 case RTA_SPORT: 2849 case RTA_DPORT: 2850 case RTA_MARK: 2851 case RTA_UID: 2852 break; 2853 default: 2854 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 2855 return -EINVAL; 2856 } 2857 } 2858 2859 return 0; 2860 } 2861 2862 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2863 struct netlink_ext_ack *extack) 2864 { 2865 struct net *net = sock_net(in_skb->sk); 2866 struct nlattr *tb[RTA_MAX+1]; 2867 u32 table_id = RT_TABLE_MAIN; 2868 __be16 sport = 0, dport = 0; 2869 struct fib_result res = {}; 2870 u8 ip_proto = IPPROTO_UDP; 2871 struct rtable *rt = NULL; 2872 struct sk_buff *skb; 2873 struct rtmsg *rtm; 2874 struct flowi4 fl4 = {}; 2875 __be32 dst = 0; 2876 __be32 src = 0; 2877 kuid_t uid; 2878 u32 iif; 2879 int err; 2880 int mark; 2881 2882 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 2883 if (err < 0) 2884 return err; 2885 2886 rtm = nlmsg_data(nlh); 2887 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2888 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2889 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2890 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2891 if (tb[RTA_UID]) 2892 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2893 else 2894 uid = (iif ? INVALID_UID : current_uid()); 2895 2896 if (tb[RTA_IP_PROTO]) { 2897 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2898 &ip_proto, AF_INET, extack); 2899 if (err) 2900 return err; 2901 } 2902 2903 if (tb[RTA_SPORT]) 2904 sport = nla_get_be16(tb[RTA_SPORT]); 2905 2906 if (tb[RTA_DPORT]) 2907 dport = nla_get_be16(tb[RTA_DPORT]); 2908 2909 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2910 if (!skb) 2911 return -ENOBUFS; 2912 2913 fl4.daddr = dst; 2914 fl4.saddr = src; 2915 fl4.flowi4_tos = rtm->rtm_tos; 2916 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2917 fl4.flowi4_mark = mark; 2918 fl4.flowi4_uid = uid; 2919 if (sport) 2920 fl4.fl4_sport = sport; 2921 if (dport) 2922 fl4.fl4_dport = dport; 2923 fl4.flowi4_proto = ip_proto; 2924 2925 rcu_read_lock(); 2926 2927 if (iif) { 2928 struct net_device *dev; 2929 2930 dev = dev_get_by_index_rcu(net, iif); 2931 if (!dev) { 2932 err = -ENODEV; 2933 goto errout_rcu; 2934 } 2935 2936 fl4.flowi4_iif = iif; /* for rt_fill_info */ 2937 skb->dev = dev; 2938 skb->mark = mark; 2939 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 2940 dev, &res); 2941 2942 rt = skb_rtable(skb); 2943 if (err == 0 && rt->dst.error) 2944 err = -rt->dst.error; 2945 } else { 2946 fl4.flowi4_iif = LOOPBACK_IFINDEX; 2947 skb->dev = net->loopback_dev; 2948 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 2949 err = 0; 2950 if (IS_ERR(rt)) 2951 err = PTR_ERR(rt); 2952 else 2953 skb_dst_set(skb, &rt->dst); 2954 } 2955 2956 if (err) 2957 goto errout_rcu; 2958 2959 if (rtm->rtm_flags & RTM_F_NOTIFY) 2960 rt->rt_flags |= RTCF_NOTIFY; 2961 2962 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 2963 table_id = res.table ? res.table->tb_id : 0; 2964 2965 /* reset skb for netlink reply msg */ 2966 skb_trim(skb, 0); 2967 skb_reset_network_header(skb); 2968 skb_reset_transport_header(skb); 2969 skb_reset_mac_header(skb); 2970 2971 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2972 if (!res.fi) { 2973 err = fib_props[res.type].error; 2974 if (!err) 2975 err = -EHOSTUNREACH; 2976 goto errout_rcu; 2977 } 2978 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 2979 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 2980 rt->rt_type, res.prefix, res.prefixlen, 2981 fl4.flowi4_tos, res.fi, 0); 2982 } else { 2983 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 2984 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 2985 } 2986 if (err < 0) 2987 goto errout_rcu; 2988 2989 rcu_read_unlock(); 2990 2991 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2992 2993 errout_free: 2994 return err; 2995 errout_rcu: 2996 rcu_read_unlock(); 2997 kfree_skb(skb); 2998 goto errout_free; 2999 } 3000 3001 void ip_rt_multicast_event(struct in_device *in_dev) 3002 { 3003 rt_cache_flush(dev_net(in_dev->dev)); 3004 } 3005 3006 #ifdef CONFIG_SYSCTL 3007 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3008 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3009 static int ip_rt_gc_elasticity __read_mostly = 8; 3010 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3011 3012 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3013 void __user *buffer, 3014 size_t *lenp, loff_t *ppos) 3015 { 3016 struct net *net = (struct net *)__ctl->extra1; 3017 3018 if (write) { 3019 rt_cache_flush(net); 3020 fnhe_genid_bump(net); 3021 return 0; 3022 } 3023 3024 return -EINVAL; 3025 } 3026 3027 static struct ctl_table ipv4_route_table[] = { 3028 { 3029 .procname = "gc_thresh", 3030 .data = &ipv4_dst_ops.gc_thresh, 3031 .maxlen = sizeof(int), 3032 .mode = 0644, 3033 .proc_handler = proc_dointvec, 3034 }, 3035 { 3036 .procname = "max_size", 3037 .data = &ip_rt_max_size, 3038 .maxlen = sizeof(int), 3039 .mode = 0644, 3040 .proc_handler = proc_dointvec, 3041 }, 3042 { 3043 /* Deprecated. Use gc_min_interval_ms */ 3044 3045 .procname = "gc_min_interval", 3046 .data = &ip_rt_gc_min_interval, 3047 .maxlen = sizeof(int), 3048 .mode = 0644, 3049 .proc_handler = proc_dointvec_jiffies, 3050 }, 3051 { 3052 .procname = "gc_min_interval_ms", 3053 .data = &ip_rt_gc_min_interval, 3054 .maxlen = sizeof(int), 3055 .mode = 0644, 3056 .proc_handler = proc_dointvec_ms_jiffies, 3057 }, 3058 { 3059 .procname = "gc_timeout", 3060 .data = &ip_rt_gc_timeout, 3061 .maxlen = sizeof(int), 3062 .mode = 0644, 3063 .proc_handler = proc_dointvec_jiffies, 3064 }, 3065 { 3066 .procname = "gc_interval", 3067 .data = &ip_rt_gc_interval, 3068 .maxlen = sizeof(int), 3069 .mode = 0644, 3070 .proc_handler = proc_dointvec_jiffies, 3071 }, 3072 { 3073 .procname = "redirect_load", 3074 .data = &ip_rt_redirect_load, 3075 .maxlen = sizeof(int), 3076 .mode = 0644, 3077 .proc_handler = proc_dointvec, 3078 }, 3079 { 3080 .procname = "redirect_number", 3081 .data = &ip_rt_redirect_number, 3082 .maxlen = sizeof(int), 3083 .mode = 0644, 3084 .proc_handler = proc_dointvec, 3085 }, 3086 { 3087 .procname = "redirect_silence", 3088 .data = &ip_rt_redirect_silence, 3089 .maxlen = sizeof(int), 3090 .mode = 0644, 3091 .proc_handler = proc_dointvec, 3092 }, 3093 { 3094 .procname = "error_cost", 3095 .data = &ip_rt_error_cost, 3096 .maxlen = sizeof(int), 3097 .mode = 0644, 3098 .proc_handler = proc_dointvec, 3099 }, 3100 { 3101 .procname = "error_burst", 3102 .data = &ip_rt_error_burst, 3103 .maxlen = sizeof(int), 3104 .mode = 0644, 3105 .proc_handler = proc_dointvec, 3106 }, 3107 { 3108 .procname = "gc_elasticity", 3109 .data = &ip_rt_gc_elasticity, 3110 .maxlen = sizeof(int), 3111 .mode = 0644, 3112 .proc_handler = proc_dointvec, 3113 }, 3114 { 3115 .procname = "mtu_expires", 3116 .data = &ip_rt_mtu_expires, 3117 .maxlen = sizeof(int), 3118 .mode = 0644, 3119 .proc_handler = proc_dointvec_jiffies, 3120 }, 3121 { 3122 .procname = "min_pmtu", 3123 .data = &ip_rt_min_pmtu, 3124 .maxlen = sizeof(int), 3125 .mode = 0644, 3126 .proc_handler = proc_dointvec_minmax, 3127 .extra1 = &ip_min_valid_pmtu, 3128 }, 3129 { 3130 .procname = "min_adv_mss", 3131 .data = &ip_rt_min_advmss, 3132 .maxlen = sizeof(int), 3133 .mode = 0644, 3134 .proc_handler = proc_dointvec, 3135 }, 3136 { } 3137 }; 3138 3139 static struct ctl_table ipv4_route_flush_table[] = { 3140 { 3141 .procname = "flush", 3142 .maxlen = sizeof(int), 3143 .mode = 0200, 3144 .proc_handler = ipv4_sysctl_rtcache_flush, 3145 }, 3146 { }, 3147 }; 3148 3149 static __net_init int sysctl_route_net_init(struct net *net) 3150 { 3151 struct ctl_table *tbl; 3152 3153 tbl = ipv4_route_flush_table; 3154 if (!net_eq(net, &init_net)) { 3155 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3156 if (!tbl) 3157 goto err_dup; 3158 3159 /* Don't export sysctls to unprivileged users */ 3160 if (net->user_ns != &init_user_ns) 3161 tbl[0].procname = NULL; 3162 } 3163 tbl[0].extra1 = net; 3164 3165 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3166 if (!net->ipv4.route_hdr) 3167 goto err_reg; 3168 return 0; 3169 3170 err_reg: 3171 if (tbl != ipv4_route_flush_table) 3172 kfree(tbl); 3173 err_dup: 3174 return -ENOMEM; 3175 } 3176 3177 static __net_exit void sysctl_route_net_exit(struct net *net) 3178 { 3179 struct ctl_table *tbl; 3180 3181 tbl = net->ipv4.route_hdr->ctl_table_arg; 3182 unregister_net_sysctl_table(net->ipv4.route_hdr); 3183 BUG_ON(tbl == ipv4_route_flush_table); 3184 kfree(tbl); 3185 } 3186 3187 static __net_initdata struct pernet_operations sysctl_route_ops = { 3188 .init = sysctl_route_net_init, 3189 .exit = sysctl_route_net_exit, 3190 }; 3191 #endif 3192 3193 static __net_init int rt_genid_init(struct net *net) 3194 { 3195 atomic_set(&net->ipv4.rt_genid, 0); 3196 atomic_set(&net->fnhe_genid, 0); 3197 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3198 return 0; 3199 } 3200 3201 static __net_initdata struct pernet_operations rt_genid_ops = { 3202 .init = rt_genid_init, 3203 }; 3204 3205 static int __net_init ipv4_inetpeer_init(struct net *net) 3206 { 3207 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3208 3209 if (!bp) 3210 return -ENOMEM; 3211 inet_peer_base_init(bp); 3212 net->ipv4.peers = bp; 3213 return 0; 3214 } 3215 3216 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3217 { 3218 struct inet_peer_base *bp = net->ipv4.peers; 3219 3220 net->ipv4.peers = NULL; 3221 inetpeer_invalidate_tree(bp); 3222 kfree(bp); 3223 } 3224 3225 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3226 .init = ipv4_inetpeer_init, 3227 .exit = ipv4_inetpeer_exit, 3228 }; 3229 3230 #ifdef CONFIG_IP_ROUTE_CLASSID 3231 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3232 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3233 3234 int __init ip_rt_init(void) 3235 { 3236 int cpu; 3237 3238 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3239 GFP_KERNEL); 3240 if (!ip_idents) 3241 panic("IP: failed to allocate ip_idents\n"); 3242 3243 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3244 3245 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3246 if (!ip_tstamps) 3247 panic("IP: failed to allocate ip_tstamps\n"); 3248 3249 for_each_possible_cpu(cpu) { 3250 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3251 3252 INIT_LIST_HEAD(&ul->head); 3253 spin_lock_init(&ul->lock); 3254 } 3255 #ifdef CONFIG_IP_ROUTE_CLASSID 3256 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3257 if (!ip_rt_acct) 3258 panic("IP: failed to allocate ip_rt_acct\n"); 3259 #endif 3260 3261 ipv4_dst_ops.kmem_cachep = 3262 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3263 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3264 3265 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3266 3267 if (dst_entries_init(&ipv4_dst_ops) < 0) 3268 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3269 3270 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3271 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3272 3273 ipv4_dst_ops.gc_thresh = ~0; 3274 ip_rt_max_size = INT_MAX; 3275 3276 devinet_init(); 3277 ip_fib_init(); 3278 3279 if (ip_rt_proc_init()) 3280 pr_err("Unable to create route proc files\n"); 3281 #ifdef CONFIG_XFRM 3282 xfrm_init(); 3283 xfrm4_init(); 3284 #endif 3285 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3286 RTNL_FLAG_DOIT_UNLOCKED); 3287 3288 #ifdef CONFIG_SYSCTL 3289 register_pernet_subsys(&sysctl_route_ops); 3290 #endif 3291 register_pernet_subsys(&rt_genid_ops); 3292 register_pernet_subsys(&ipv4_inetpeer_ops); 3293 return 0; 3294 } 3295 3296 #ifdef CONFIG_SYSCTL 3297 /* 3298 * We really need to sanitize the damn ipv4 init order, then all 3299 * this nonsense will go away. 3300 */ 3301 void __init ip_static_sysctl_init(void) 3302 { 3303 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3304 } 3305 #endif 3306