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_send_dest_unreach(struct sk_buff *skb) 1187 { 1188 struct ip_options opt; 1189 int res; 1190 1191 /* Recompile ip options since IPCB may not be valid anymore. 1192 * Also check we have a reasonable ipv4 header. 1193 */ 1194 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1195 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1196 return; 1197 1198 memset(&opt, 0, sizeof(opt)); 1199 if (ip_hdr(skb)->ihl > 5) { 1200 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1201 return; 1202 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1203 1204 rcu_read_lock(); 1205 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1206 rcu_read_unlock(); 1207 1208 if (res) 1209 return; 1210 } 1211 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1212 } 1213 1214 static void ipv4_link_failure(struct sk_buff *skb) 1215 { 1216 struct rtable *rt; 1217 1218 ipv4_send_dest_unreach(skb); 1219 1220 rt = skb_rtable(skb); 1221 if (rt) 1222 dst_set_expires(&rt->dst, 0); 1223 } 1224 1225 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1226 { 1227 pr_debug("%s: %pI4 -> %pI4, %s\n", 1228 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1229 skb->dev ? skb->dev->name : "?"); 1230 kfree_skb(skb); 1231 WARN_ON(1); 1232 return 0; 1233 } 1234 1235 /* 1236 We do not cache source address of outgoing interface, 1237 because it is used only by IP RR, TS and SRR options, 1238 so that it out of fast path. 1239 1240 BTW remember: "addr" is allowed to be not aligned 1241 in IP options! 1242 */ 1243 1244 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1245 { 1246 __be32 src; 1247 1248 if (rt_is_output_route(rt)) 1249 src = ip_hdr(skb)->saddr; 1250 else { 1251 struct fib_result res; 1252 struct iphdr *iph = ip_hdr(skb); 1253 struct flowi4 fl4 = { 1254 .daddr = iph->daddr, 1255 .saddr = iph->saddr, 1256 .flowi4_tos = RT_TOS(iph->tos), 1257 .flowi4_oif = rt->dst.dev->ifindex, 1258 .flowi4_iif = skb->dev->ifindex, 1259 .flowi4_mark = skb->mark, 1260 }; 1261 1262 rcu_read_lock(); 1263 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1264 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1265 else 1266 src = inet_select_addr(rt->dst.dev, 1267 rt_nexthop(rt, iph->daddr), 1268 RT_SCOPE_UNIVERSE); 1269 rcu_read_unlock(); 1270 } 1271 memcpy(addr, &src, 4); 1272 } 1273 1274 #ifdef CONFIG_IP_ROUTE_CLASSID 1275 static void set_class_tag(struct rtable *rt, u32 tag) 1276 { 1277 if (!(rt->dst.tclassid & 0xFFFF)) 1278 rt->dst.tclassid |= tag & 0xFFFF; 1279 if (!(rt->dst.tclassid & 0xFFFF0000)) 1280 rt->dst.tclassid |= tag & 0xFFFF0000; 1281 } 1282 #endif 1283 1284 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1285 { 1286 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1287 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1288 ip_rt_min_advmss); 1289 1290 return min(advmss, IPV4_MAX_PMTU - header_size); 1291 } 1292 1293 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1294 { 1295 const struct rtable *rt = (const struct rtable *) dst; 1296 unsigned int mtu = rt->rt_pmtu; 1297 1298 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1299 mtu = dst_metric_raw(dst, RTAX_MTU); 1300 1301 if (mtu) 1302 return mtu; 1303 1304 mtu = READ_ONCE(dst->dev->mtu); 1305 1306 if (unlikely(ip_mtu_locked(dst))) { 1307 if (rt->rt_uses_gateway && mtu > 576) 1308 mtu = 576; 1309 } 1310 1311 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1312 1313 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1314 } 1315 1316 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr) 1317 { 1318 struct fnhe_hash_bucket *hash; 1319 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1320 u32 hval = fnhe_hashfun(daddr); 1321 1322 spin_lock_bh(&fnhe_lock); 1323 1324 hash = rcu_dereference_protected(nh->nh_exceptions, 1325 lockdep_is_held(&fnhe_lock)); 1326 hash += hval; 1327 1328 fnhe_p = &hash->chain; 1329 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1330 while (fnhe) { 1331 if (fnhe->fnhe_daddr == daddr) { 1332 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1333 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1334 /* set fnhe_daddr to 0 to ensure it won't bind with 1335 * new dsts in rt_bind_exception(). 1336 */ 1337 fnhe->fnhe_daddr = 0; 1338 fnhe_flush_routes(fnhe); 1339 kfree_rcu(fnhe, rcu); 1340 break; 1341 } 1342 fnhe_p = &fnhe->fnhe_next; 1343 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1344 lockdep_is_held(&fnhe_lock)); 1345 } 1346 1347 spin_unlock_bh(&fnhe_lock); 1348 } 1349 1350 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1351 { 1352 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1353 struct fib_nh_exception *fnhe; 1354 u32 hval; 1355 1356 if (!hash) 1357 return NULL; 1358 1359 hval = fnhe_hashfun(daddr); 1360 1361 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1362 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1363 if (fnhe->fnhe_daddr == daddr) { 1364 if (fnhe->fnhe_expires && 1365 time_after(jiffies, fnhe->fnhe_expires)) { 1366 ip_del_fnhe(nh, daddr); 1367 break; 1368 } 1369 return fnhe; 1370 } 1371 } 1372 return NULL; 1373 } 1374 1375 /* MTU selection: 1376 * 1. mtu on route is locked - use it 1377 * 2. mtu from nexthop exception 1378 * 3. mtu from egress device 1379 */ 1380 1381 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1382 { 1383 struct fib_info *fi = res->fi; 1384 struct fib_nh *nh = &fi->fib_nh[res->nh_sel]; 1385 struct net_device *dev = nh->nh_dev; 1386 u32 mtu = 0; 1387 1388 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1389 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1390 mtu = fi->fib_mtu; 1391 1392 if (likely(!mtu)) { 1393 struct fib_nh_exception *fnhe; 1394 1395 fnhe = find_exception(nh, daddr); 1396 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1397 mtu = fnhe->fnhe_pmtu; 1398 } 1399 1400 if (likely(!mtu)) 1401 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1402 1403 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu); 1404 } 1405 1406 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1407 __be32 daddr, const bool do_cache) 1408 { 1409 bool ret = false; 1410 1411 spin_lock_bh(&fnhe_lock); 1412 1413 if (daddr == fnhe->fnhe_daddr) { 1414 struct rtable __rcu **porig; 1415 struct rtable *orig; 1416 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1417 1418 if (rt_is_input_route(rt)) 1419 porig = &fnhe->fnhe_rth_input; 1420 else 1421 porig = &fnhe->fnhe_rth_output; 1422 orig = rcu_dereference(*porig); 1423 1424 if (fnhe->fnhe_genid != genid) { 1425 fnhe->fnhe_genid = genid; 1426 fnhe->fnhe_gw = 0; 1427 fnhe->fnhe_pmtu = 0; 1428 fnhe->fnhe_expires = 0; 1429 fnhe->fnhe_mtu_locked = false; 1430 fnhe_flush_routes(fnhe); 1431 orig = NULL; 1432 } 1433 fill_route_from_fnhe(rt, fnhe); 1434 if (!rt->rt_gateway) 1435 rt->rt_gateway = daddr; 1436 1437 if (do_cache) { 1438 dst_hold(&rt->dst); 1439 rcu_assign_pointer(*porig, rt); 1440 if (orig) { 1441 dst_dev_put(&orig->dst); 1442 dst_release(&orig->dst); 1443 } 1444 ret = true; 1445 } 1446 1447 fnhe->fnhe_stamp = jiffies; 1448 } 1449 spin_unlock_bh(&fnhe_lock); 1450 1451 return ret; 1452 } 1453 1454 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1455 { 1456 struct rtable *orig, *prev, **p; 1457 bool ret = true; 1458 1459 if (rt_is_input_route(rt)) { 1460 p = (struct rtable **)&nh->nh_rth_input; 1461 } else { 1462 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1463 } 1464 orig = *p; 1465 1466 /* hold dst before doing cmpxchg() to avoid race condition 1467 * on this dst 1468 */ 1469 dst_hold(&rt->dst); 1470 prev = cmpxchg(p, orig, rt); 1471 if (prev == orig) { 1472 if (orig) { 1473 dst_dev_put(&orig->dst); 1474 dst_release(&orig->dst); 1475 } 1476 } else { 1477 dst_release(&rt->dst); 1478 ret = false; 1479 } 1480 1481 return ret; 1482 } 1483 1484 struct uncached_list { 1485 spinlock_t lock; 1486 struct list_head head; 1487 }; 1488 1489 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1490 1491 void rt_add_uncached_list(struct rtable *rt) 1492 { 1493 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1494 1495 rt->rt_uncached_list = ul; 1496 1497 spin_lock_bh(&ul->lock); 1498 list_add_tail(&rt->rt_uncached, &ul->head); 1499 spin_unlock_bh(&ul->lock); 1500 } 1501 1502 void rt_del_uncached_list(struct rtable *rt) 1503 { 1504 if (!list_empty(&rt->rt_uncached)) { 1505 struct uncached_list *ul = rt->rt_uncached_list; 1506 1507 spin_lock_bh(&ul->lock); 1508 list_del(&rt->rt_uncached); 1509 spin_unlock_bh(&ul->lock); 1510 } 1511 } 1512 1513 static void ipv4_dst_destroy(struct dst_entry *dst) 1514 { 1515 struct rtable *rt = (struct rtable *)dst; 1516 1517 ip_dst_metrics_put(dst); 1518 rt_del_uncached_list(rt); 1519 } 1520 1521 void rt_flush_dev(struct net_device *dev) 1522 { 1523 struct net *net = dev_net(dev); 1524 struct rtable *rt; 1525 int cpu; 1526 1527 for_each_possible_cpu(cpu) { 1528 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1529 1530 spin_lock_bh(&ul->lock); 1531 list_for_each_entry(rt, &ul->head, rt_uncached) { 1532 if (rt->dst.dev != dev) 1533 continue; 1534 rt->dst.dev = net->loopback_dev; 1535 dev_hold(rt->dst.dev); 1536 dev_put(dev); 1537 } 1538 spin_unlock_bh(&ul->lock); 1539 } 1540 } 1541 1542 static bool rt_cache_valid(const struct rtable *rt) 1543 { 1544 return rt && 1545 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1546 !rt_is_expired(rt); 1547 } 1548 1549 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1550 const struct fib_result *res, 1551 struct fib_nh_exception *fnhe, 1552 struct fib_info *fi, u16 type, u32 itag, 1553 const bool do_cache) 1554 { 1555 bool cached = false; 1556 1557 if (fi) { 1558 struct fib_nh *nh = &FIB_RES_NH(*res); 1559 1560 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1561 rt->rt_gateway = nh->nh_gw; 1562 rt->rt_uses_gateway = 1; 1563 } 1564 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1565 1566 #ifdef CONFIG_IP_ROUTE_CLASSID 1567 rt->dst.tclassid = nh->nh_tclassid; 1568 #endif 1569 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 1570 if (unlikely(fnhe)) 1571 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1572 else if (do_cache) 1573 cached = rt_cache_route(nh, rt); 1574 if (unlikely(!cached)) { 1575 /* Routes we intend to cache in nexthop exception or 1576 * FIB nexthop have the DST_NOCACHE bit clear. 1577 * However, if we are unsuccessful at storing this 1578 * route into the cache we really need to set it. 1579 */ 1580 if (!rt->rt_gateway) 1581 rt->rt_gateway = daddr; 1582 rt_add_uncached_list(rt); 1583 } 1584 } else 1585 rt_add_uncached_list(rt); 1586 1587 #ifdef CONFIG_IP_ROUTE_CLASSID 1588 #ifdef CONFIG_IP_MULTIPLE_TABLES 1589 set_class_tag(rt, res->tclassid); 1590 #endif 1591 set_class_tag(rt, itag); 1592 #endif 1593 } 1594 1595 struct rtable *rt_dst_alloc(struct net_device *dev, 1596 unsigned int flags, u16 type, 1597 bool nopolicy, bool noxfrm, bool will_cache) 1598 { 1599 struct rtable *rt; 1600 1601 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1602 (will_cache ? 0 : DST_HOST) | 1603 (nopolicy ? DST_NOPOLICY : 0) | 1604 (noxfrm ? DST_NOXFRM : 0)); 1605 1606 if (rt) { 1607 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1608 rt->rt_flags = flags; 1609 rt->rt_type = type; 1610 rt->rt_is_input = 0; 1611 rt->rt_iif = 0; 1612 rt->rt_pmtu = 0; 1613 rt->rt_mtu_locked = 0; 1614 rt->rt_gateway = 0; 1615 rt->rt_uses_gateway = 0; 1616 INIT_LIST_HEAD(&rt->rt_uncached); 1617 1618 rt->dst.output = ip_output; 1619 if (flags & RTCF_LOCAL) 1620 rt->dst.input = ip_local_deliver; 1621 } 1622 1623 return rt; 1624 } 1625 EXPORT_SYMBOL(rt_dst_alloc); 1626 1627 /* called in rcu_read_lock() section */ 1628 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1629 u8 tos, struct net_device *dev, 1630 struct in_device *in_dev, u32 *itag) 1631 { 1632 int err; 1633 1634 /* Primary sanity checks. */ 1635 if (!in_dev) 1636 return -EINVAL; 1637 1638 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1639 skb->protocol != htons(ETH_P_IP)) 1640 return -EINVAL; 1641 1642 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1643 return -EINVAL; 1644 1645 if (ipv4_is_zeronet(saddr)) { 1646 if (!ipv4_is_local_multicast(daddr) && 1647 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1648 return -EINVAL; 1649 } else { 1650 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1651 in_dev, itag); 1652 if (err < 0) 1653 return err; 1654 } 1655 return 0; 1656 } 1657 1658 /* called in rcu_read_lock() section */ 1659 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1660 u8 tos, struct net_device *dev, int our) 1661 { 1662 struct in_device *in_dev = __in_dev_get_rcu(dev); 1663 unsigned int flags = RTCF_MULTICAST; 1664 struct rtable *rth; 1665 u32 itag = 0; 1666 int err; 1667 1668 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1669 if (err) 1670 return err; 1671 1672 if (our) 1673 flags |= RTCF_LOCAL; 1674 1675 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1676 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1677 if (!rth) 1678 return -ENOBUFS; 1679 1680 #ifdef CONFIG_IP_ROUTE_CLASSID 1681 rth->dst.tclassid = itag; 1682 #endif 1683 rth->dst.output = ip_rt_bug; 1684 rth->rt_is_input= 1; 1685 1686 #ifdef CONFIG_IP_MROUTE 1687 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1688 rth->dst.input = ip_mr_input; 1689 #endif 1690 RT_CACHE_STAT_INC(in_slow_mc); 1691 1692 skb_dst_set(skb, &rth->dst); 1693 return 0; 1694 } 1695 1696 1697 static void ip_handle_martian_source(struct net_device *dev, 1698 struct in_device *in_dev, 1699 struct sk_buff *skb, 1700 __be32 daddr, 1701 __be32 saddr) 1702 { 1703 RT_CACHE_STAT_INC(in_martian_src); 1704 #ifdef CONFIG_IP_ROUTE_VERBOSE 1705 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1706 /* 1707 * RFC1812 recommendation, if source is martian, 1708 * the only hint is MAC header. 1709 */ 1710 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1711 &daddr, &saddr, dev->name); 1712 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1713 print_hex_dump(KERN_WARNING, "ll header: ", 1714 DUMP_PREFIX_OFFSET, 16, 1, 1715 skb_mac_header(skb), 1716 dev->hard_header_len, false); 1717 } 1718 } 1719 #endif 1720 } 1721 1722 /* called in rcu_read_lock() section */ 1723 static int __mkroute_input(struct sk_buff *skb, 1724 const struct fib_result *res, 1725 struct in_device *in_dev, 1726 __be32 daddr, __be32 saddr, u32 tos) 1727 { 1728 struct fib_nh_exception *fnhe; 1729 struct rtable *rth; 1730 int err; 1731 struct in_device *out_dev; 1732 bool do_cache; 1733 u32 itag = 0; 1734 1735 /* get a working reference to the output device */ 1736 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1737 if (!out_dev) { 1738 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1739 return -EINVAL; 1740 } 1741 1742 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1743 in_dev->dev, in_dev, &itag); 1744 if (err < 0) { 1745 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1746 saddr); 1747 1748 goto cleanup; 1749 } 1750 1751 do_cache = res->fi && !itag; 1752 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1753 skb->protocol == htons(ETH_P_IP) && 1754 (IN_DEV_SHARED_MEDIA(out_dev) || 1755 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1756 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1757 1758 if (skb->protocol != htons(ETH_P_IP)) { 1759 /* Not IP (i.e. ARP). Do not create route, if it is 1760 * invalid for proxy arp. DNAT routes are always valid. 1761 * 1762 * Proxy arp feature have been extended to allow, ARP 1763 * replies back to the same interface, to support 1764 * Private VLAN switch technologies. See arp.c. 1765 */ 1766 if (out_dev == in_dev && 1767 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1768 err = -EINVAL; 1769 goto cleanup; 1770 } 1771 } 1772 1773 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1774 if (do_cache) { 1775 if (fnhe) 1776 rth = rcu_dereference(fnhe->fnhe_rth_input); 1777 else 1778 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1779 if (rt_cache_valid(rth)) { 1780 skb_dst_set_noref(skb, &rth->dst); 1781 goto out; 1782 } 1783 } 1784 1785 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1786 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1787 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1788 if (!rth) { 1789 err = -ENOBUFS; 1790 goto cleanup; 1791 } 1792 1793 rth->rt_is_input = 1; 1794 RT_CACHE_STAT_INC(in_slow_tot); 1795 1796 rth->dst.input = ip_forward; 1797 1798 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1799 do_cache); 1800 lwtunnel_set_redirect(&rth->dst); 1801 skb_dst_set(skb, &rth->dst); 1802 out: 1803 err = 0; 1804 cleanup: 1805 return err; 1806 } 1807 1808 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1809 /* To make ICMP packets follow the right flow, the multipath hash is 1810 * calculated from the inner IP addresses. 1811 */ 1812 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1813 struct flow_keys *hash_keys) 1814 { 1815 const struct iphdr *outer_iph = ip_hdr(skb); 1816 const struct iphdr *key_iph = outer_iph; 1817 const struct iphdr *inner_iph; 1818 const struct icmphdr *icmph; 1819 struct iphdr _inner_iph; 1820 struct icmphdr _icmph; 1821 1822 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1823 goto out; 1824 1825 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1826 goto out; 1827 1828 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1829 &_icmph); 1830 if (!icmph) 1831 goto out; 1832 1833 if (icmph->type != ICMP_DEST_UNREACH && 1834 icmph->type != ICMP_REDIRECT && 1835 icmph->type != ICMP_TIME_EXCEEDED && 1836 icmph->type != ICMP_PARAMETERPROB) 1837 goto out; 1838 1839 inner_iph = skb_header_pointer(skb, 1840 outer_iph->ihl * 4 + sizeof(_icmph), 1841 sizeof(_inner_iph), &_inner_iph); 1842 if (!inner_iph) 1843 goto out; 1844 1845 key_iph = inner_iph; 1846 out: 1847 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1848 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1849 } 1850 1851 /* if skb is set it will be used and fl4 can be NULL */ 1852 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 1853 const struct sk_buff *skb, struct flow_keys *flkeys) 1854 { 1855 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 1856 struct flow_keys hash_keys; 1857 u32 mhash; 1858 1859 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 1860 case 0: 1861 memset(&hash_keys, 0, sizeof(hash_keys)); 1862 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1863 if (skb) { 1864 ip_multipath_l3_keys(skb, &hash_keys); 1865 } else { 1866 hash_keys.addrs.v4addrs.src = fl4->saddr; 1867 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1868 } 1869 break; 1870 case 1: 1871 /* skb is currently provided only when forwarding */ 1872 if (skb) { 1873 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 1874 struct flow_keys keys; 1875 1876 /* short-circuit if we already have L4 hash present */ 1877 if (skb->l4_hash) 1878 return skb_get_hash_raw(skb) >> 1; 1879 1880 memset(&hash_keys, 0, sizeof(hash_keys)); 1881 1882 if (!flkeys) { 1883 skb_flow_dissect_flow_keys(skb, &keys, flag); 1884 flkeys = &keys; 1885 } 1886 1887 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1888 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 1889 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 1890 hash_keys.ports.src = flkeys->ports.src; 1891 hash_keys.ports.dst = flkeys->ports.dst; 1892 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 1893 } else { 1894 memset(&hash_keys, 0, sizeof(hash_keys)); 1895 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1896 hash_keys.addrs.v4addrs.src = fl4->saddr; 1897 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1898 hash_keys.ports.src = fl4->fl4_sport; 1899 hash_keys.ports.dst = fl4->fl4_dport; 1900 hash_keys.basic.ip_proto = fl4->flowi4_proto; 1901 } 1902 break; 1903 } 1904 mhash = flow_hash_from_keys(&hash_keys); 1905 1906 if (multipath_hash) 1907 mhash = jhash_2words(mhash, multipath_hash, 0); 1908 1909 return mhash >> 1; 1910 } 1911 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1912 1913 static int ip_mkroute_input(struct sk_buff *skb, 1914 struct fib_result *res, 1915 struct in_device *in_dev, 1916 __be32 daddr, __be32 saddr, u32 tos, 1917 struct flow_keys *hkeys) 1918 { 1919 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1920 if (res->fi && res->fi->fib_nhs > 1) { 1921 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1922 1923 fib_select_multipath(res, h); 1924 } 1925 #endif 1926 1927 /* create a routing cache entry */ 1928 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1929 } 1930 1931 /* 1932 * NOTE. We drop all the packets that has local source 1933 * addresses, because every properly looped back packet 1934 * must have correct destination already attached by output routine. 1935 * 1936 * Such approach solves two big problems: 1937 * 1. Not simplex devices are handled properly. 1938 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1939 * called with rcu_read_lock() 1940 */ 1941 1942 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1943 u8 tos, struct net_device *dev, 1944 struct fib_result *res) 1945 { 1946 struct in_device *in_dev = __in_dev_get_rcu(dev); 1947 struct flow_keys *flkeys = NULL, _flkeys; 1948 struct net *net = dev_net(dev); 1949 struct ip_tunnel_info *tun_info; 1950 int err = -EINVAL; 1951 unsigned int flags = 0; 1952 u32 itag = 0; 1953 struct rtable *rth; 1954 struct flowi4 fl4; 1955 bool do_cache; 1956 1957 /* IP on this device is disabled. */ 1958 1959 if (!in_dev) 1960 goto out; 1961 1962 /* Check for the most weird martians, which can be not detected 1963 by fib_lookup. 1964 */ 1965 1966 tun_info = skb_tunnel_info(skb); 1967 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1968 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1969 else 1970 fl4.flowi4_tun_key.tun_id = 0; 1971 skb_dst_drop(skb); 1972 1973 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1974 goto martian_source; 1975 1976 res->fi = NULL; 1977 res->table = NULL; 1978 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1979 goto brd_input; 1980 1981 /* Accept zero addresses only to limited broadcast; 1982 * I even do not know to fix it or not. Waiting for complains :-) 1983 */ 1984 if (ipv4_is_zeronet(saddr)) 1985 goto martian_source; 1986 1987 if (ipv4_is_zeronet(daddr)) 1988 goto martian_destination; 1989 1990 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1991 * and call it once if daddr or/and saddr are loopback addresses 1992 */ 1993 if (ipv4_is_loopback(daddr)) { 1994 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1995 goto martian_destination; 1996 } else if (ipv4_is_loopback(saddr)) { 1997 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1998 goto martian_source; 1999 } 2000 2001 /* 2002 * Now we are ready to route packet. 2003 */ 2004 fl4.flowi4_oif = 0; 2005 fl4.flowi4_iif = dev->ifindex; 2006 fl4.flowi4_mark = skb->mark; 2007 fl4.flowi4_tos = tos; 2008 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2009 fl4.flowi4_flags = 0; 2010 fl4.daddr = daddr; 2011 fl4.saddr = saddr; 2012 fl4.flowi4_uid = sock_net_uid(net, NULL); 2013 2014 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2015 flkeys = &_flkeys; 2016 } else { 2017 fl4.flowi4_proto = 0; 2018 fl4.fl4_sport = 0; 2019 fl4.fl4_dport = 0; 2020 } 2021 2022 err = fib_lookup(net, &fl4, res, 0); 2023 if (err != 0) { 2024 if (!IN_DEV_FORWARD(in_dev)) 2025 err = -EHOSTUNREACH; 2026 goto no_route; 2027 } 2028 2029 if (res->type == RTN_BROADCAST) { 2030 if (IN_DEV_BFORWARD(in_dev)) 2031 goto make_route; 2032 goto brd_input; 2033 } 2034 2035 if (res->type == RTN_LOCAL) { 2036 err = fib_validate_source(skb, saddr, daddr, tos, 2037 0, dev, in_dev, &itag); 2038 if (err < 0) 2039 goto martian_source; 2040 goto local_input; 2041 } 2042 2043 if (!IN_DEV_FORWARD(in_dev)) { 2044 err = -EHOSTUNREACH; 2045 goto no_route; 2046 } 2047 if (res->type != RTN_UNICAST) 2048 goto martian_destination; 2049 2050 make_route: 2051 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2052 out: return err; 2053 2054 brd_input: 2055 if (skb->protocol != htons(ETH_P_IP)) 2056 goto e_inval; 2057 2058 if (!ipv4_is_zeronet(saddr)) { 2059 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2060 in_dev, &itag); 2061 if (err < 0) 2062 goto martian_source; 2063 } 2064 flags |= RTCF_BROADCAST; 2065 res->type = RTN_BROADCAST; 2066 RT_CACHE_STAT_INC(in_brd); 2067 2068 local_input: 2069 do_cache = false; 2070 if (res->fi) { 2071 if (!itag) { 2072 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 2073 if (rt_cache_valid(rth)) { 2074 skb_dst_set_noref(skb, &rth->dst); 2075 err = 0; 2076 goto out; 2077 } 2078 do_cache = true; 2079 } 2080 } 2081 2082 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2083 flags | RTCF_LOCAL, res->type, 2084 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2085 if (!rth) 2086 goto e_nobufs; 2087 2088 rth->dst.output= ip_rt_bug; 2089 #ifdef CONFIG_IP_ROUTE_CLASSID 2090 rth->dst.tclassid = itag; 2091 #endif 2092 rth->rt_is_input = 1; 2093 2094 RT_CACHE_STAT_INC(in_slow_tot); 2095 if (res->type == RTN_UNREACHABLE) { 2096 rth->dst.input= ip_error; 2097 rth->dst.error= -err; 2098 rth->rt_flags &= ~RTCF_LOCAL; 2099 } 2100 2101 if (do_cache) { 2102 struct fib_nh *nh = &FIB_RES_NH(*res); 2103 2104 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 2105 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2106 WARN_ON(rth->dst.input == lwtunnel_input); 2107 rth->dst.lwtstate->orig_input = rth->dst.input; 2108 rth->dst.input = lwtunnel_input; 2109 } 2110 2111 if (unlikely(!rt_cache_route(nh, rth))) 2112 rt_add_uncached_list(rth); 2113 } 2114 skb_dst_set(skb, &rth->dst); 2115 err = 0; 2116 goto out; 2117 2118 no_route: 2119 RT_CACHE_STAT_INC(in_no_route); 2120 res->type = RTN_UNREACHABLE; 2121 res->fi = NULL; 2122 res->table = NULL; 2123 goto local_input; 2124 2125 /* 2126 * Do not cache martian addresses: they should be logged (RFC1812) 2127 */ 2128 martian_destination: 2129 RT_CACHE_STAT_INC(in_martian_dst); 2130 #ifdef CONFIG_IP_ROUTE_VERBOSE 2131 if (IN_DEV_LOG_MARTIANS(in_dev)) 2132 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2133 &daddr, &saddr, dev->name); 2134 #endif 2135 2136 e_inval: 2137 err = -EINVAL; 2138 goto out; 2139 2140 e_nobufs: 2141 err = -ENOBUFS; 2142 goto out; 2143 2144 martian_source: 2145 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2146 goto out; 2147 } 2148 2149 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2150 u8 tos, struct net_device *dev) 2151 { 2152 struct fib_result res; 2153 int err; 2154 2155 tos &= IPTOS_RT_MASK; 2156 rcu_read_lock(); 2157 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2158 rcu_read_unlock(); 2159 2160 return err; 2161 } 2162 EXPORT_SYMBOL(ip_route_input_noref); 2163 2164 /* called with rcu_read_lock held */ 2165 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2166 u8 tos, struct net_device *dev, struct fib_result *res) 2167 { 2168 /* Multicast recognition logic is moved from route cache to here. 2169 The problem was that too many Ethernet cards have broken/missing 2170 hardware multicast filters :-( As result the host on multicasting 2171 network acquires a lot of useless route cache entries, sort of 2172 SDR messages from all the world. Now we try to get rid of them. 2173 Really, provided software IP multicast filter is organized 2174 reasonably (at least, hashed), it does not result in a slowdown 2175 comparing with route cache reject entries. 2176 Note, that multicast routers are not affected, because 2177 route cache entry is created eventually. 2178 */ 2179 if (ipv4_is_multicast(daddr)) { 2180 struct in_device *in_dev = __in_dev_get_rcu(dev); 2181 int our = 0; 2182 int err = -EINVAL; 2183 2184 if (!in_dev) 2185 return err; 2186 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2187 ip_hdr(skb)->protocol); 2188 2189 /* check l3 master if no match yet */ 2190 if (!our && netif_is_l3_slave(dev)) { 2191 struct in_device *l3_in_dev; 2192 2193 l3_in_dev = __in_dev_get_rcu(skb->dev); 2194 if (l3_in_dev) 2195 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2196 ip_hdr(skb)->protocol); 2197 } 2198 2199 if (our 2200 #ifdef CONFIG_IP_MROUTE 2201 || 2202 (!ipv4_is_local_multicast(daddr) && 2203 IN_DEV_MFORWARD(in_dev)) 2204 #endif 2205 ) { 2206 err = ip_route_input_mc(skb, daddr, saddr, 2207 tos, dev, our); 2208 } 2209 return err; 2210 } 2211 2212 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2213 } 2214 2215 /* called with rcu_read_lock() */ 2216 static struct rtable *__mkroute_output(const struct fib_result *res, 2217 const struct flowi4 *fl4, int orig_oif, 2218 struct net_device *dev_out, 2219 unsigned int flags) 2220 { 2221 struct fib_info *fi = res->fi; 2222 struct fib_nh_exception *fnhe; 2223 struct in_device *in_dev; 2224 u16 type = res->type; 2225 struct rtable *rth; 2226 bool do_cache; 2227 2228 in_dev = __in_dev_get_rcu(dev_out); 2229 if (!in_dev) 2230 return ERR_PTR(-EINVAL); 2231 2232 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2233 if (ipv4_is_loopback(fl4->saddr) && 2234 !(dev_out->flags & IFF_LOOPBACK) && 2235 !netif_is_l3_master(dev_out)) 2236 return ERR_PTR(-EINVAL); 2237 2238 if (ipv4_is_lbcast(fl4->daddr)) 2239 type = RTN_BROADCAST; 2240 else if (ipv4_is_multicast(fl4->daddr)) 2241 type = RTN_MULTICAST; 2242 else if (ipv4_is_zeronet(fl4->daddr)) 2243 return ERR_PTR(-EINVAL); 2244 2245 if (dev_out->flags & IFF_LOOPBACK) 2246 flags |= RTCF_LOCAL; 2247 2248 do_cache = true; 2249 if (type == RTN_BROADCAST) { 2250 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2251 fi = NULL; 2252 } else if (type == RTN_MULTICAST) { 2253 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2254 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2255 fl4->flowi4_proto)) 2256 flags &= ~RTCF_LOCAL; 2257 else 2258 do_cache = false; 2259 /* If multicast route do not exist use 2260 * default one, but do not gateway in this case. 2261 * Yes, it is hack. 2262 */ 2263 if (fi && res->prefixlen < 4) 2264 fi = NULL; 2265 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2266 (orig_oif != dev_out->ifindex)) { 2267 /* For local routes that require a particular output interface 2268 * we do not want to cache the result. Caching the result 2269 * causes incorrect behaviour when there are multiple source 2270 * addresses on the interface, the end result being that if the 2271 * intended recipient is waiting on that interface for the 2272 * packet he won't receive it because it will be delivered on 2273 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2274 * be set to the loopback interface as well. 2275 */ 2276 do_cache = false; 2277 } 2278 2279 fnhe = NULL; 2280 do_cache &= fi != NULL; 2281 if (fi) { 2282 struct rtable __rcu **prth; 2283 struct fib_nh *nh = &FIB_RES_NH(*res); 2284 2285 fnhe = find_exception(nh, fl4->daddr); 2286 if (!do_cache) 2287 goto add; 2288 if (fnhe) { 2289 prth = &fnhe->fnhe_rth_output; 2290 } else { 2291 if (unlikely(fl4->flowi4_flags & 2292 FLOWI_FLAG_KNOWN_NH && 2293 !(nh->nh_gw && 2294 nh->nh_scope == RT_SCOPE_LINK))) { 2295 do_cache = false; 2296 goto add; 2297 } 2298 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 2299 } 2300 rth = rcu_dereference(*prth); 2301 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2302 return rth; 2303 } 2304 2305 add: 2306 rth = rt_dst_alloc(dev_out, flags, type, 2307 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2308 IN_DEV_CONF_GET(in_dev, NOXFRM), 2309 do_cache); 2310 if (!rth) 2311 return ERR_PTR(-ENOBUFS); 2312 2313 rth->rt_iif = orig_oif; 2314 2315 RT_CACHE_STAT_INC(out_slow_tot); 2316 2317 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2318 if (flags & RTCF_LOCAL && 2319 !(dev_out->flags & IFF_LOOPBACK)) { 2320 rth->dst.output = ip_mc_output; 2321 RT_CACHE_STAT_INC(out_slow_mc); 2322 } 2323 #ifdef CONFIG_IP_MROUTE 2324 if (type == RTN_MULTICAST) { 2325 if (IN_DEV_MFORWARD(in_dev) && 2326 !ipv4_is_local_multicast(fl4->daddr)) { 2327 rth->dst.input = ip_mr_input; 2328 rth->dst.output = ip_mc_output; 2329 } 2330 } 2331 #endif 2332 } 2333 2334 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2335 lwtunnel_set_redirect(&rth->dst); 2336 2337 return rth; 2338 } 2339 2340 /* 2341 * Major route resolver routine. 2342 */ 2343 2344 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2345 const struct sk_buff *skb) 2346 { 2347 __u8 tos = RT_FL_TOS(fl4); 2348 struct fib_result res = { 2349 .type = RTN_UNSPEC, 2350 .fi = NULL, 2351 .table = NULL, 2352 .tclassid = 0, 2353 }; 2354 struct rtable *rth; 2355 2356 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2357 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2358 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2359 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2360 2361 rcu_read_lock(); 2362 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2363 rcu_read_unlock(); 2364 2365 return rth; 2366 } 2367 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2368 2369 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2370 struct fib_result *res, 2371 const struct sk_buff *skb) 2372 { 2373 struct net_device *dev_out = NULL; 2374 int orig_oif = fl4->flowi4_oif; 2375 unsigned int flags = 0; 2376 struct rtable *rth; 2377 int err = -ENETUNREACH; 2378 2379 if (fl4->saddr) { 2380 rth = ERR_PTR(-EINVAL); 2381 if (ipv4_is_multicast(fl4->saddr) || 2382 ipv4_is_lbcast(fl4->saddr) || 2383 ipv4_is_zeronet(fl4->saddr)) 2384 goto out; 2385 2386 /* I removed check for oif == dev_out->oif here. 2387 It was wrong for two reasons: 2388 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2389 is assigned to multiple interfaces. 2390 2. Moreover, we are allowed to send packets with saddr 2391 of another iface. --ANK 2392 */ 2393 2394 if (fl4->flowi4_oif == 0 && 2395 (ipv4_is_multicast(fl4->daddr) || 2396 ipv4_is_lbcast(fl4->daddr))) { 2397 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2398 dev_out = __ip_dev_find(net, fl4->saddr, false); 2399 if (!dev_out) 2400 goto out; 2401 2402 /* Special hack: user can direct multicasts 2403 and limited broadcast via necessary interface 2404 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2405 This hack is not just for fun, it allows 2406 vic,vat and friends to work. 2407 They bind socket to loopback, set ttl to zero 2408 and expect that it will work. 2409 From the viewpoint of routing cache they are broken, 2410 because we are not allowed to build multicast path 2411 with loopback source addr (look, routing cache 2412 cannot know, that ttl is zero, so that packet 2413 will not leave this host and route is valid). 2414 Luckily, this hack is good workaround. 2415 */ 2416 2417 fl4->flowi4_oif = dev_out->ifindex; 2418 goto make_route; 2419 } 2420 2421 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2422 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2423 if (!__ip_dev_find(net, fl4->saddr, false)) 2424 goto out; 2425 } 2426 } 2427 2428 2429 if (fl4->flowi4_oif) { 2430 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2431 rth = ERR_PTR(-ENODEV); 2432 if (!dev_out) 2433 goto out; 2434 2435 /* RACE: Check return value of inet_select_addr instead. */ 2436 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2437 rth = ERR_PTR(-ENETUNREACH); 2438 goto out; 2439 } 2440 if (ipv4_is_local_multicast(fl4->daddr) || 2441 ipv4_is_lbcast(fl4->daddr) || 2442 fl4->flowi4_proto == IPPROTO_IGMP) { 2443 if (!fl4->saddr) 2444 fl4->saddr = inet_select_addr(dev_out, 0, 2445 RT_SCOPE_LINK); 2446 goto make_route; 2447 } 2448 if (!fl4->saddr) { 2449 if (ipv4_is_multicast(fl4->daddr)) 2450 fl4->saddr = inet_select_addr(dev_out, 0, 2451 fl4->flowi4_scope); 2452 else if (!fl4->daddr) 2453 fl4->saddr = inet_select_addr(dev_out, 0, 2454 RT_SCOPE_HOST); 2455 } 2456 } 2457 2458 if (!fl4->daddr) { 2459 fl4->daddr = fl4->saddr; 2460 if (!fl4->daddr) 2461 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2462 dev_out = net->loopback_dev; 2463 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2464 res->type = RTN_LOCAL; 2465 flags |= RTCF_LOCAL; 2466 goto make_route; 2467 } 2468 2469 err = fib_lookup(net, fl4, res, 0); 2470 if (err) { 2471 res->fi = NULL; 2472 res->table = NULL; 2473 if (fl4->flowi4_oif && 2474 (ipv4_is_multicast(fl4->daddr) || 2475 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2476 /* Apparently, routing tables are wrong. Assume, 2477 that the destination is on link. 2478 2479 WHY? DW. 2480 Because we are allowed to send to iface 2481 even if it has NO routes and NO assigned 2482 addresses. When oif is specified, routing 2483 tables are looked up with only one purpose: 2484 to catch if destination is gatewayed, rather than 2485 direct. Moreover, if MSG_DONTROUTE is set, 2486 we send packet, ignoring both routing tables 2487 and ifaddr state. --ANK 2488 2489 2490 We could make it even if oif is unknown, 2491 likely IPv6, but we do not. 2492 */ 2493 2494 if (fl4->saddr == 0) 2495 fl4->saddr = inet_select_addr(dev_out, 0, 2496 RT_SCOPE_LINK); 2497 res->type = RTN_UNICAST; 2498 goto make_route; 2499 } 2500 rth = ERR_PTR(err); 2501 goto out; 2502 } 2503 2504 if (res->type == RTN_LOCAL) { 2505 if (!fl4->saddr) { 2506 if (res->fi->fib_prefsrc) 2507 fl4->saddr = res->fi->fib_prefsrc; 2508 else 2509 fl4->saddr = fl4->daddr; 2510 } 2511 2512 /* L3 master device is the loopback for that domain */ 2513 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2514 net->loopback_dev; 2515 2516 /* make sure orig_oif points to fib result device even 2517 * though packet rx/tx happens over loopback or l3mdev 2518 */ 2519 orig_oif = FIB_RES_OIF(*res); 2520 2521 fl4->flowi4_oif = dev_out->ifindex; 2522 flags |= RTCF_LOCAL; 2523 goto make_route; 2524 } 2525 2526 fib_select_path(net, res, fl4, skb); 2527 2528 dev_out = FIB_RES_DEV(*res); 2529 fl4->flowi4_oif = dev_out->ifindex; 2530 2531 2532 make_route: 2533 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2534 2535 out: 2536 return rth; 2537 } 2538 2539 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2540 { 2541 return NULL; 2542 } 2543 2544 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2545 { 2546 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2547 2548 return mtu ? : dst->dev->mtu; 2549 } 2550 2551 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2552 struct sk_buff *skb, u32 mtu) 2553 { 2554 } 2555 2556 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2557 struct sk_buff *skb) 2558 { 2559 } 2560 2561 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2562 unsigned long old) 2563 { 2564 return NULL; 2565 } 2566 2567 static struct dst_ops ipv4_dst_blackhole_ops = { 2568 .family = AF_INET, 2569 .check = ipv4_blackhole_dst_check, 2570 .mtu = ipv4_blackhole_mtu, 2571 .default_advmss = ipv4_default_advmss, 2572 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2573 .redirect = ipv4_rt_blackhole_redirect, 2574 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2575 .neigh_lookup = ipv4_neigh_lookup, 2576 }; 2577 2578 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2579 { 2580 struct rtable *ort = (struct rtable *) dst_orig; 2581 struct rtable *rt; 2582 2583 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2584 if (rt) { 2585 struct dst_entry *new = &rt->dst; 2586 2587 new->__use = 1; 2588 new->input = dst_discard; 2589 new->output = dst_discard_out; 2590 2591 new->dev = net->loopback_dev; 2592 if (new->dev) 2593 dev_hold(new->dev); 2594 2595 rt->rt_is_input = ort->rt_is_input; 2596 rt->rt_iif = ort->rt_iif; 2597 rt->rt_pmtu = ort->rt_pmtu; 2598 rt->rt_mtu_locked = ort->rt_mtu_locked; 2599 2600 rt->rt_genid = rt_genid_ipv4(net); 2601 rt->rt_flags = ort->rt_flags; 2602 rt->rt_type = ort->rt_type; 2603 rt->rt_gateway = ort->rt_gateway; 2604 rt->rt_uses_gateway = ort->rt_uses_gateway; 2605 2606 INIT_LIST_HEAD(&rt->rt_uncached); 2607 } 2608 2609 dst_release(dst_orig); 2610 2611 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2612 } 2613 2614 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2615 const struct sock *sk) 2616 { 2617 struct rtable *rt = __ip_route_output_key(net, flp4); 2618 2619 if (IS_ERR(rt)) 2620 return rt; 2621 2622 if (flp4->flowi4_proto) 2623 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2624 flowi4_to_flowi(flp4), 2625 sk, 0); 2626 2627 return rt; 2628 } 2629 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2630 2631 /* called with rcu_read_lock held */ 2632 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2633 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2634 struct sk_buff *skb, u32 portid, u32 seq) 2635 { 2636 struct rtmsg *r; 2637 struct nlmsghdr *nlh; 2638 unsigned long expires = 0; 2639 u32 error; 2640 u32 metrics[RTAX_MAX]; 2641 2642 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2643 if (!nlh) 2644 return -EMSGSIZE; 2645 2646 r = nlmsg_data(nlh); 2647 r->rtm_family = AF_INET; 2648 r->rtm_dst_len = 32; 2649 r->rtm_src_len = 0; 2650 r->rtm_tos = fl4->flowi4_tos; 2651 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2652 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2653 goto nla_put_failure; 2654 r->rtm_type = rt->rt_type; 2655 r->rtm_scope = RT_SCOPE_UNIVERSE; 2656 r->rtm_protocol = RTPROT_UNSPEC; 2657 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2658 if (rt->rt_flags & RTCF_NOTIFY) 2659 r->rtm_flags |= RTM_F_NOTIFY; 2660 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2661 r->rtm_flags |= RTCF_DOREDIRECT; 2662 2663 if (nla_put_in_addr(skb, RTA_DST, dst)) 2664 goto nla_put_failure; 2665 if (src) { 2666 r->rtm_src_len = 32; 2667 if (nla_put_in_addr(skb, RTA_SRC, src)) 2668 goto nla_put_failure; 2669 } 2670 if (rt->dst.dev && 2671 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2672 goto nla_put_failure; 2673 #ifdef CONFIG_IP_ROUTE_CLASSID 2674 if (rt->dst.tclassid && 2675 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2676 goto nla_put_failure; 2677 #endif 2678 if (!rt_is_input_route(rt) && 2679 fl4->saddr != src) { 2680 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2681 goto nla_put_failure; 2682 } 2683 if (rt->rt_uses_gateway && 2684 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2685 goto nla_put_failure; 2686 2687 expires = rt->dst.expires; 2688 if (expires) { 2689 unsigned long now = jiffies; 2690 2691 if (time_before(now, expires)) 2692 expires -= now; 2693 else 2694 expires = 0; 2695 } 2696 2697 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2698 if (rt->rt_pmtu && expires) 2699 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2700 if (rt->rt_mtu_locked && expires) 2701 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2702 if (rtnetlink_put_metrics(skb, metrics) < 0) 2703 goto nla_put_failure; 2704 2705 if (fl4->flowi4_mark && 2706 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2707 goto nla_put_failure; 2708 2709 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2710 nla_put_u32(skb, RTA_UID, 2711 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2712 goto nla_put_failure; 2713 2714 error = rt->dst.error; 2715 2716 if (rt_is_input_route(rt)) { 2717 #ifdef CONFIG_IP_MROUTE 2718 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2719 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2720 int err = ipmr_get_route(net, skb, 2721 fl4->saddr, fl4->daddr, 2722 r, portid); 2723 2724 if (err <= 0) { 2725 if (err == 0) 2726 return 0; 2727 goto nla_put_failure; 2728 } 2729 } else 2730 #endif 2731 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2732 goto nla_put_failure; 2733 } 2734 2735 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2736 goto nla_put_failure; 2737 2738 nlmsg_end(skb, nlh); 2739 return 0; 2740 2741 nla_put_failure: 2742 nlmsg_cancel(skb, nlh); 2743 return -EMSGSIZE; 2744 } 2745 2746 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2747 u8 ip_proto, __be16 sport, 2748 __be16 dport) 2749 { 2750 struct sk_buff *skb; 2751 struct iphdr *iph; 2752 2753 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2754 if (!skb) 2755 return NULL; 2756 2757 /* Reserve room for dummy headers, this skb can pass 2758 * through good chunk of routing engine. 2759 */ 2760 skb_reset_mac_header(skb); 2761 skb_reset_network_header(skb); 2762 skb->protocol = htons(ETH_P_IP); 2763 iph = skb_put(skb, sizeof(struct iphdr)); 2764 iph->protocol = ip_proto; 2765 iph->saddr = src; 2766 iph->daddr = dst; 2767 iph->version = 0x4; 2768 iph->frag_off = 0; 2769 iph->ihl = 0x5; 2770 skb_set_transport_header(skb, skb->len); 2771 2772 switch (iph->protocol) { 2773 case IPPROTO_UDP: { 2774 struct udphdr *udph; 2775 2776 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2777 udph->source = sport; 2778 udph->dest = dport; 2779 udph->len = sizeof(struct udphdr); 2780 udph->check = 0; 2781 break; 2782 } 2783 case IPPROTO_TCP: { 2784 struct tcphdr *tcph; 2785 2786 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2787 tcph->source = sport; 2788 tcph->dest = dport; 2789 tcph->doff = sizeof(struct tcphdr) / 4; 2790 tcph->rst = 1; 2791 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2792 src, dst, 0); 2793 break; 2794 } 2795 case IPPROTO_ICMP: { 2796 struct icmphdr *icmph; 2797 2798 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2799 icmph->type = ICMP_ECHO; 2800 icmph->code = 0; 2801 } 2802 } 2803 2804 return skb; 2805 } 2806 2807 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 2808 const struct nlmsghdr *nlh, 2809 struct nlattr **tb, 2810 struct netlink_ext_ack *extack) 2811 { 2812 struct rtmsg *rtm; 2813 int i, err; 2814 2815 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 2816 NL_SET_ERR_MSG(extack, 2817 "ipv4: Invalid header for route get request"); 2818 return -EINVAL; 2819 } 2820 2821 if (!netlink_strict_get_check(skb)) 2822 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, 2823 rtm_ipv4_policy, extack); 2824 2825 rtm = nlmsg_data(nlh); 2826 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 2827 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 2828 rtm->rtm_table || rtm->rtm_protocol || 2829 rtm->rtm_scope || rtm->rtm_type) { 2830 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 2831 return -EINVAL; 2832 } 2833 2834 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 2835 RTM_F_LOOKUP_TABLE | 2836 RTM_F_FIB_MATCH)) { 2837 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 2838 return -EINVAL; 2839 } 2840 2841 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 2842 rtm_ipv4_policy, extack); 2843 if (err) 2844 return err; 2845 2846 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 2847 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 2848 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 2849 return -EINVAL; 2850 } 2851 2852 for (i = 0; i <= RTA_MAX; i++) { 2853 if (!tb[i]) 2854 continue; 2855 2856 switch (i) { 2857 case RTA_IIF: 2858 case RTA_OIF: 2859 case RTA_SRC: 2860 case RTA_DST: 2861 case RTA_IP_PROTO: 2862 case RTA_SPORT: 2863 case RTA_DPORT: 2864 case RTA_MARK: 2865 case RTA_UID: 2866 break; 2867 default: 2868 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 2869 return -EINVAL; 2870 } 2871 } 2872 2873 return 0; 2874 } 2875 2876 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2877 struct netlink_ext_ack *extack) 2878 { 2879 struct net *net = sock_net(in_skb->sk); 2880 struct nlattr *tb[RTA_MAX+1]; 2881 u32 table_id = RT_TABLE_MAIN; 2882 __be16 sport = 0, dport = 0; 2883 struct fib_result res = {}; 2884 u8 ip_proto = IPPROTO_UDP; 2885 struct rtable *rt = NULL; 2886 struct sk_buff *skb; 2887 struct rtmsg *rtm; 2888 struct flowi4 fl4 = {}; 2889 __be32 dst = 0; 2890 __be32 src = 0; 2891 kuid_t uid; 2892 u32 iif; 2893 int err; 2894 int mark; 2895 2896 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 2897 if (err < 0) 2898 return err; 2899 2900 rtm = nlmsg_data(nlh); 2901 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2902 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2903 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2904 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2905 if (tb[RTA_UID]) 2906 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2907 else 2908 uid = (iif ? INVALID_UID : current_uid()); 2909 2910 if (tb[RTA_IP_PROTO]) { 2911 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2912 &ip_proto, AF_INET, extack); 2913 if (err) 2914 return err; 2915 } 2916 2917 if (tb[RTA_SPORT]) 2918 sport = nla_get_be16(tb[RTA_SPORT]); 2919 2920 if (tb[RTA_DPORT]) 2921 dport = nla_get_be16(tb[RTA_DPORT]); 2922 2923 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2924 if (!skb) 2925 return -ENOBUFS; 2926 2927 fl4.daddr = dst; 2928 fl4.saddr = src; 2929 fl4.flowi4_tos = rtm->rtm_tos; 2930 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2931 fl4.flowi4_mark = mark; 2932 fl4.flowi4_uid = uid; 2933 if (sport) 2934 fl4.fl4_sport = sport; 2935 if (dport) 2936 fl4.fl4_dport = dport; 2937 fl4.flowi4_proto = ip_proto; 2938 2939 rcu_read_lock(); 2940 2941 if (iif) { 2942 struct net_device *dev; 2943 2944 dev = dev_get_by_index_rcu(net, iif); 2945 if (!dev) { 2946 err = -ENODEV; 2947 goto errout_rcu; 2948 } 2949 2950 fl4.flowi4_iif = iif; /* for rt_fill_info */ 2951 skb->dev = dev; 2952 skb->mark = mark; 2953 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 2954 dev, &res); 2955 2956 rt = skb_rtable(skb); 2957 if (err == 0 && rt->dst.error) 2958 err = -rt->dst.error; 2959 } else { 2960 fl4.flowi4_iif = LOOPBACK_IFINDEX; 2961 skb->dev = net->loopback_dev; 2962 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 2963 err = 0; 2964 if (IS_ERR(rt)) 2965 err = PTR_ERR(rt); 2966 else 2967 skb_dst_set(skb, &rt->dst); 2968 } 2969 2970 if (err) 2971 goto errout_rcu; 2972 2973 if (rtm->rtm_flags & RTM_F_NOTIFY) 2974 rt->rt_flags |= RTCF_NOTIFY; 2975 2976 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 2977 table_id = res.table ? res.table->tb_id : 0; 2978 2979 /* reset skb for netlink reply msg */ 2980 skb_trim(skb, 0); 2981 skb_reset_network_header(skb); 2982 skb_reset_transport_header(skb); 2983 skb_reset_mac_header(skb); 2984 2985 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2986 if (!res.fi) { 2987 err = fib_props[res.type].error; 2988 if (!err) 2989 err = -EHOSTUNREACH; 2990 goto errout_rcu; 2991 } 2992 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 2993 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 2994 rt->rt_type, res.prefix, res.prefixlen, 2995 fl4.flowi4_tos, res.fi, 0); 2996 } else { 2997 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 2998 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 2999 } 3000 if (err < 0) 3001 goto errout_rcu; 3002 3003 rcu_read_unlock(); 3004 3005 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3006 3007 errout_free: 3008 return err; 3009 errout_rcu: 3010 rcu_read_unlock(); 3011 kfree_skb(skb); 3012 goto errout_free; 3013 } 3014 3015 void ip_rt_multicast_event(struct in_device *in_dev) 3016 { 3017 rt_cache_flush(dev_net(in_dev->dev)); 3018 } 3019 3020 #ifdef CONFIG_SYSCTL 3021 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3022 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3023 static int ip_rt_gc_elasticity __read_mostly = 8; 3024 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3025 3026 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3027 void __user *buffer, 3028 size_t *lenp, loff_t *ppos) 3029 { 3030 struct net *net = (struct net *)__ctl->extra1; 3031 3032 if (write) { 3033 rt_cache_flush(net); 3034 fnhe_genid_bump(net); 3035 return 0; 3036 } 3037 3038 return -EINVAL; 3039 } 3040 3041 static struct ctl_table ipv4_route_table[] = { 3042 { 3043 .procname = "gc_thresh", 3044 .data = &ipv4_dst_ops.gc_thresh, 3045 .maxlen = sizeof(int), 3046 .mode = 0644, 3047 .proc_handler = proc_dointvec, 3048 }, 3049 { 3050 .procname = "max_size", 3051 .data = &ip_rt_max_size, 3052 .maxlen = sizeof(int), 3053 .mode = 0644, 3054 .proc_handler = proc_dointvec, 3055 }, 3056 { 3057 /* Deprecated. Use gc_min_interval_ms */ 3058 3059 .procname = "gc_min_interval", 3060 .data = &ip_rt_gc_min_interval, 3061 .maxlen = sizeof(int), 3062 .mode = 0644, 3063 .proc_handler = proc_dointvec_jiffies, 3064 }, 3065 { 3066 .procname = "gc_min_interval_ms", 3067 .data = &ip_rt_gc_min_interval, 3068 .maxlen = sizeof(int), 3069 .mode = 0644, 3070 .proc_handler = proc_dointvec_ms_jiffies, 3071 }, 3072 { 3073 .procname = "gc_timeout", 3074 .data = &ip_rt_gc_timeout, 3075 .maxlen = sizeof(int), 3076 .mode = 0644, 3077 .proc_handler = proc_dointvec_jiffies, 3078 }, 3079 { 3080 .procname = "gc_interval", 3081 .data = &ip_rt_gc_interval, 3082 .maxlen = sizeof(int), 3083 .mode = 0644, 3084 .proc_handler = proc_dointvec_jiffies, 3085 }, 3086 { 3087 .procname = "redirect_load", 3088 .data = &ip_rt_redirect_load, 3089 .maxlen = sizeof(int), 3090 .mode = 0644, 3091 .proc_handler = proc_dointvec, 3092 }, 3093 { 3094 .procname = "redirect_number", 3095 .data = &ip_rt_redirect_number, 3096 .maxlen = sizeof(int), 3097 .mode = 0644, 3098 .proc_handler = proc_dointvec, 3099 }, 3100 { 3101 .procname = "redirect_silence", 3102 .data = &ip_rt_redirect_silence, 3103 .maxlen = sizeof(int), 3104 .mode = 0644, 3105 .proc_handler = proc_dointvec, 3106 }, 3107 { 3108 .procname = "error_cost", 3109 .data = &ip_rt_error_cost, 3110 .maxlen = sizeof(int), 3111 .mode = 0644, 3112 .proc_handler = proc_dointvec, 3113 }, 3114 { 3115 .procname = "error_burst", 3116 .data = &ip_rt_error_burst, 3117 .maxlen = sizeof(int), 3118 .mode = 0644, 3119 .proc_handler = proc_dointvec, 3120 }, 3121 { 3122 .procname = "gc_elasticity", 3123 .data = &ip_rt_gc_elasticity, 3124 .maxlen = sizeof(int), 3125 .mode = 0644, 3126 .proc_handler = proc_dointvec, 3127 }, 3128 { 3129 .procname = "mtu_expires", 3130 .data = &ip_rt_mtu_expires, 3131 .maxlen = sizeof(int), 3132 .mode = 0644, 3133 .proc_handler = proc_dointvec_jiffies, 3134 }, 3135 { 3136 .procname = "min_pmtu", 3137 .data = &ip_rt_min_pmtu, 3138 .maxlen = sizeof(int), 3139 .mode = 0644, 3140 .proc_handler = proc_dointvec_minmax, 3141 .extra1 = &ip_min_valid_pmtu, 3142 }, 3143 { 3144 .procname = "min_adv_mss", 3145 .data = &ip_rt_min_advmss, 3146 .maxlen = sizeof(int), 3147 .mode = 0644, 3148 .proc_handler = proc_dointvec, 3149 }, 3150 { } 3151 }; 3152 3153 static struct ctl_table ipv4_route_flush_table[] = { 3154 { 3155 .procname = "flush", 3156 .maxlen = sizeof(int), 3157 .mode = 0200, 3158 .proc_handler = ipv4_sysctl_rtcache_flush, 3159 }, 3160 { }, 3161 }; 3162 3163 static __net_init int sysctl_route_net_init(struct net *net) 3164 { 3165 struct ctl_table *tbl; 3166 3167 tbl = ipv4_route_flush_table; 3168 if (!net_eq(net, &init_net)) { 3169 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3170 if (!tbl) 3171 goto err_dup; 3172 3173 /* Don't export sysctls to unprivileged users */ 3174 if (net->user_ns != &init_user_ns) 3175 tbl[0].procname = NULL; 3176 } 3177 tbl[0].extra1 = net; 3178 3179 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3180 if (!net->ipv4.route_hdr) 3181 goto err_reg; 3182 return 0; 3183 3184 err_reg: 3185 if (tbl != ipv4_route_flush_table) 3186 kfree(tbl); 3187 err_dup: 3188 return -ENOMEM; 3189 } 3190 3191 static __net_exit void sysctl_route_net_exit(struct net *net) 3192 { 3193 struct ctl_table *tbl; 3194 3195 tbl = net->ipv4.route_hdr->ctl_table_arg; 3196 unregister_net_sysctl_table(net->ipv4.route_hdr); 3197 BUG_ON(tbl == ipv4_route_flush_table); 3198 kfree(tbl); 3199 } 3200 3201 static __net_initdata struct pernet_operations sysctl_route_ops = { 3202 .init = sysctl_route_net_init, 3203 .exit = sysctl_route_net_exit, 3204 }; 3205 #endif 3206 3207 static __net_init int rt_genid_init(struct net *net) 3208 { 3209 atomic_set(&net->ipv4.rt_genid, 0); 3210 atomic_set(&net->fnhe_genid, 0); 3211 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3212 return 0; 3213 } 3214 3215 static __net_initdata struct pernet_operations rt_genid_ops = { 3216 .init = rt_genid_init, 3217 }; 3218 3219 static int __net_init ipv4_inetpeer_init(struct net *net) 3220 { 3221 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3222 3223 if (!bp) 3224 return -ENOMEM; 3225 inet_peer_base_init(bp); 3226 net->ipv4.peers = bp; 3227 return 0; 3228 } 3229 3230 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3231 { 3232 struct inet_peer_base *bp = net->ipv4.peers; 3233 3234 net->ipv4.peers = NULL; 3235 inetpeer_invalidate_tree(bp); 3236 kfree(bp); 3237 } 3238 3239 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3240 .init = ipv4_inetpeer_init, 3241 .exit = ipv4_inetpeer_exit, 3242 }; 3243 3244 #ifdef CONFIG_IP_ROUTE_CLASSID 3245 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3246 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3247 3248 int __init ip_rt_init(void) 3249 { 3250 int cpu; 3251 3252 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3253 GFP_KERNEL); 3254 if (!ip_idents) 3255 panic("IP: failed to allocate ip_idents\n"); 3256 3257 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3258 3259 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3260 if (!ip_tstamps) 3261 panic("IP: failed to allocate ip_tstamps\n"); 3262 3263 for_each_possible_cpu(cpu) { 3264 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3265 3266 INIT_LIST_HEAD(&ul->head); 3267 spin_lock_init(&ul->lock); 3268 } 3269 #ifdef CONFIG_IP_ROUTE_CLASSID 3270 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3271 if (!ip_rt_acct) 3272 panic("IP: failed to allocate ip_rt_acct\n"); 3273 #endif 3274 3275 ipv4_dst_ops.kmem_cachep = 3276 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3277 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3278 3279 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3280 3281 if (dst_entries_init(&ipv4_dst_ops) < 0) 3282 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3283 3284 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3285 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3286 3287 ipv4_dst_ops.gc_thresh = ~0; 3288 ip_rt_max_size = INT_MAX; 3289 3290 devinet_init(); 3291 ip_fib_init(); 3292 3293 if (ip_rt_proc_init()) 3294 pr_err("Unable to create route proc files\n"); 3295 #ifdef CONFIG_XFRM 3296 xfrm_init(); 3297 xfrm4_init(); 3298 #endif 3299 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3300 RTNL_FLAG_DOIT_UNLOCKED); 3301 3302 #ifdef CONFIG_SYSCTL 3303 register_pernet_subsys(&sysctl_route_ops); 3304 #endif 3305 register_pernet_subsys(&rt_genid_ops); 3306 register_pernet_subsys(&ipv4_inetpeer_ops); 3307 return 0; 3308 } 3309 3310 #ifdef CONFIG_SYSCTL 3311 /* 3312 * We really need to sanitize the damn ipv4 init order, then all 3313 * this nonsense will go away. 3314 */ 3315 void __init ip_static_sysctl_init(void) 3316 { 3317 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3318 } 3319 #endif 3320