1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * ROUTE - implementation of the IP router. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 13 * 14 * Fixes: 15 * Alan Cox : Verify area fixes. 16 * Alan Cox : cli() protects routing changes 17 * Rui Oliveira : ICMP routing table updates 18 * (rco@di.uminho.pt) Routing table insertion and update 19 * Linus Torvalds : Rewrote bits to be sensible 20 * Alan Cox : Added BSD route gw semantics 21 * Alan Cox : Super /proc >4K 22 * Alan Cox : MTU in route table 23 * Alan Cox : MSS actually. Also added the window 24 * clamper. 25 * Sam Lantinga : Fixed route matching in rt_del() 26 * Alan Cox : Routing cache support. 27 * Alan Cox : Removed compatibility cruft. 28 * Alan Cox : RTF_REJECT support. 29 * Alan Cox : TCP irtt support. 30 * Jonathan Naylor : Added Metric support. 31 * Miquel van Smoorenburg : BSD API fixes. 32 * Miquel van Smoorenburg : Metrics. 33 * Alan Cox : Use __u32 properly 34 * Alan Cox : Aligned routing errors more closely with BSD 35 * our system is still very different. 36 * Alan Cox : Faster /proc handling 37 * Alexey Kuznetsov : Massive rework to support tree based routing, 38 * routing caches and better behaviour. 39 * 40 * Olaf Erb : irtt wasn't being copied right. 41 * Bjorn Ekwall : Kerneld route support. 42 * Alan Cox : Multicast fixed (I hope) 43 * Pavel Krauz : Limited broadcast fixed 44 * Mike McLagan : Routing by source 45 * Alexey Kuznetsov : End of old history. Split to fib.c and 46 * route.c and rewritten from scratch. 47 * Andi Kleen : Load-limit warning messages. 48 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 52 * Marc Boucher : routing by fwmark 53 * Robert Olsson : Added rt_cache statistics 54 * Arnaldo C. Melo : Convert proc stuff to seq_file 55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 57 * Ilia Sotnikov : Removed TOS from hash calculations 58 * 59 * This program is free software; you can redistribute it and/or 60 * modify it under the terms of the GNU General Public License 61 * as published by the Free Software Foundation; either version 62 * 2 of the License, or (at your option) any later version. 63 */ 64 65 #define pr_fmt(fmt) "IPv4: " fmt 66 67 #include <linux/module.h> 68 #include <linux/uaccess.h> 69 #include <linux/bitops.h> 70 #include <linux/types.h> 71 #include <linux/kernel.h> 72 #include <linux/mm.h> 73 #include <linux/string.h> 74 #include <linux/socket.h> 75 #include <linux/sockios.h> 76 #include <linux/errno.h> 77 #include <linux/in.h> 78 #include <linux/inet.h> 79 #include <linux/netdevice.h> 80 #include <linux/proc_fs.h> 81 #include <linux/init.h> 82 #include <linux/skbuff.h> 83 #include <linux/inetdevice.h> 84 #include <linux/igmp.h> 85 #include <linux/pkt_sched.h> 86 #include <linux/mroute.h> 87 #include <linux/netfilter_ipv4.h> 88 #include <linux/random.h> 89 #include <linux/rcupdate.h> 90 #include <linux/times.h> 91 #include <linux/slab.h> 92 #include <linux/jhash.h> 93 #include <net/dst.h> 94 #include <net/dst_metadata.h> 95 #include <net/net_namespace.h> 96 #include <net/protocol.h> 97 #include <net/ip.h> 98 #include <net/route.h> 99 #include <net/inetpeer.h> 100 #include <net/sock.h> 101 #include <net/ip_fib.h> 102 #include <net/arp.h> 103 #include <net/tcp.h> 104 #include <net/icmp.h> 105 #include <net/xfrm.h> 106 #include <net/lwtunnel.h> 107 #include <net/netevent.h> 108 #include <net/rtnetlink.h> 109 #ifdef CONFIG_SYSCTL 110 #include <linux/sysctl.h> 111 #endif 112 #include <net/secure_seq.h> 113 #include <net/ip_tunnels.h> 114 #include <net/l3mdev.h> 115 116 #include "fib_lookup.h" 117 118 #define RT_FL_TOS(oldflp4) \ 119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 120 121 #define RT_GC_TIMEOUT (300*HZ) 122 123 static int ip_rt_max_size; 124 static int ip_rt_redirect_number __read_mostly = 9; 125 static int ip_rt_redirect_load __read_mostly = HZ / 50; 126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 127 static int ip_rt_error_cost __read_mostly = HZ; 128 static int ip_rt_error_burst __read_mostly = 5 * HZ; 129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 130 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 131 static int ip_rt_min_advmss __read_mostly = 256; 132 133 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 134 135 /* 136 * Interface to generic destination cache. 137 */ 138 139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 141 static unsigned int ipv4_mtu(const struct dst_entry *dst); 142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 143 static void ipv4_link_failure(struct sk_buff *skb); 144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 145 struct sk_buff *skb, u32 mtu); 146 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 147 struct sk_buff *skb); 148 static void ipv4_dst_destroy(struct dst_entry *dst); 149 150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 151 { 152 WARN_ON(1); 153 return NULL; 154 } 155 156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 157 struct sk_buff *skb, 158 const void *daddr); 159 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 160 161 static struct dst_ops ipv4_dst_ops = { 162 .family = AF_INET, 163 .check = ipv4_dst_check, 164 .default_advmss = ipv4_default_advmss, 165 .mtu = ipv4_mtu, 166 .cow_metrics = ipv4_cow_metrics, 167 .destroy = ipv4_dst_destroy, 168 .negative_advice = ipv4_negative_advice, 169 .link_failure = ipv4_link_failure, 170 .update_pmtu = ip_rt_update_pmtu, 171 .redirect = ip_do_redirect, 172 .local_out = __ip_local_out, 173 .neigh_lookup = ipv4_neigh_lookup, 174 .confirm_neigh = ipv4_confirm_neigh, 175 }; 176 177 #define ECN_OR_COST(class) TC_PRIO_##class 178 179 const __u8 ip_tos2prio[16] = { 180 TC_PRIO_BESTEFFORT, 181 ECN_OR_COST(BESTEFFORT), 182 TC_PRIO_BESTEFFORT, 183 ECN_OR_COST(BESTEFFORT), 184 TC_PRIO_BULK, 185 ECN_OR_COST(BULK), 186 TC_PRIO_BULK, 187 ECN_OR_COST(BULK), 188 TC_PRIO_INTERACTIVE, 189 ECN_OR_COST(INTERACTIVE), 190 TC_PRIO_INTERACTIVE, 191 ECN_OR_COST(INTERACTIVE), 192 TC_PRIO_INTERACTIVE_BULK, 193 ECN_OR_COST(INTERACTIVE_BULK), 194 TC_PRIO_INTERACTIVE_BULK, 195 ECN_OR_COST(INTERACTIVE_BULK) 196 }; 197 EXPORT_SYMBOL(ip_tos2prio); 198 199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 200 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 201 202 #ifdef CONFIG_PROC_FS 203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 204 { 205 if (*pos) 206 return NULL; 207 return SEQ_START_TOKEN; 208 } 209 210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 211 { 212 ++*pos; 213 return NULL; 214 } 215 216 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 217 { 218 } 219 220 static int rt_cache_seq_show(struct seq_file *seq, void *v) 221 { 222 if (v == SEQ_START_TOKEN) 223 seq_printf(seq, "%-127s\n", 224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 226 "HHUptod\tSpecDst"); 227 return 0; 228 } 229 230 static const struct seq_operations rt_cache_seq_ops = { 231 .start = rt_cache_seq_start, 232 .next = rt_cache_seq_next, 233 .stop = rt_cache_seq_stop, 234 .show = rt_cache_seq_show, 235 }; 236 237 static int rt_cache_seq_open(struct inode *inode, struct file *file) 238 { 239 return seq_open(file, &rt_cache_seq_ops); 240 } 241 242 static const struct file_operations rt_cache_seq_fops = { 243 .open = rt_cache_seq_open, 244 .read = seq_read, 245 .llseek = seq_lseek, 246 .release = seq_release, 247 }; 248 249 250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 251 { 252 int cpu; 253 254 if (*pos == 0) 255 return SEQ_START_TOKEN; 256 257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 258 if (!cpu_possible(cpu)) 259 continue; 260 *pos = cpu+1; 261 return &per_cpu(rt_cache_stat, cpu); 262 } 263 return NULL; 264 } 265 266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 267 { 268 int cpu; 269 270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 271 if (!cpu_possible(cpu)) 272 continue; 273 *pos = cpu+1; 274 return &per_cpu(rt_cache_stat, cpu); 275 } 276 return NULL; 277 278 } 279 280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 281 { 282 283 } 284 285 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 286 { 287 struct rt_cache_stat *st = v; 288 289 if (v == SEQ_START_TOKEN) { 290 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 291 return 0; 292 } 293 294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 296 dst_entries_get_slow(&ipv4_dst_ops), 297 0, /* st->in_hit */ 298 st->in_slow_tot, 299 st->in_slow_mc, 300 st->in_no_route, 301 st->in_brd, 302 st->in_martian_dst, 303 st->in_martian_src, 304 305 0, /* st->out_hit */ 306 st->out_slow_tot, 307 st->out_slow_mc, 308 309 0, /* st->gc_total */ 310 0, /* st->gc_ignored */ 311 0, /* st->gc_goal_miss */ 312 0, /* st->gc_dst_overflow */ 313 0, /* st->in_hlist_search */ 314 0 /* st->out_hlist_search */ 315 ); 316 return 0; 317 } 318 319 static const struct seq_operations rt_cpu_seq_ops = { 320 .start = rt_cpu_seq_start, 321 .next = rt_cpu_seq_next, 322 .stop = rt_cpu_seq_stop, 323 .show = rt_cpu_seq_show, 324 }; 325 326 327 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 328 { 329 return seq_open(file, &rt_cpu_seq_ops); 330 } 331 332 static const struct file_operations rt_cpu_seq_fops = { 333 .open = rt_cpu_seq_open, 334 .read = seq_read, 335 .llseek = seq_lseek, 336 .release = seq_release, 337 }; 338 339 #ifdef CONFIG_IP_ROUTE_CLASSID 340 static int rt_acct_proc_show(struct seq_file *m, void *v) 341 { 342 struct ip_rt_acct *dst, *src; 343 unsigned int i, j; 344 345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 346 if (!dst) 347 return -ENOMEM; 348 349 for_each_possible_cpu(i) { 350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 351 for (j = 0; j < 256; j++) { 352 dst[j].o_bytes += src[j].o_bytes; 353 dst[j].o_packets += src[j].o_packets; 354 dst[j].i_bytes += src[j].i_bytes; 355 dst[j].i_packets += src[j].i_packets; 356 } 357 } 358 359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 360 kfree(dst); 361 return 0; 362 } 363 #endif 364 365 static int __net_init ip_rt_do_proc_init(struct net *net) 366 { 367 struct proc_dir_entry *pde; 368 369 pde = proc_create("rt_cache", 0444, net->proc_net, 370 &rt_cache_seq_fops); 371 if (!pde) 372 goto err1; 373 374 pde = proc_create("rt_cache", 0444, 375 net->proc_net_stat, &rt_cpu_seq_fops); 376 if (!pde) 377 goto err2; 378 379 #ifdef CONFIG_IP_ROUTE_CLASSID 380 pde = proc_create_single("rt_acct", 0, net->proc_net, 381 rt_acct_proc_show); 382 if (!pde) 383 goto err3; 384 #endif 385 return 0; 386 387 #ifdef CONFIG_IP_ROUTE_CLASSID 388 err3: 389 remove_proc_entry("rt_cache", net->proc_net_stat); 390 #endif 391 err2: 392 remove_proc_entry("rt_cache", net->proc_net); 393 err1: 394 return -ENOMEM; 395 } 396 397 static void __net_exit ip_rt_do_proc_exit(struct net *net) 398 { 399 remove_proc_entry("rt_cache", net->proc_net_stat); 400 remove_proc_entry("rt_cache", net->proc_net); 401 #ifdef CONFIG_IP_ROUTE_CLASSID 402 remove_proc_entry("rt_acct", net->proc_net); 403 #endif 404 } 405 406 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 407 .init = ip_rt_do_proc_init, 408 .exit = ip_rt_do_proc_exit, 409 }; 410 411 static int __init ip_rt_proc_init(void) 412 { 413 return register_pernet_subsys(&ip_rt_proc_ops); 414 } 415 416 #else 417 static inline int ip_rt_proc_init(void) 418 { 419 return 0; 420 } 421 #endif /* CONFIG_PROC_FS */ 422 423 static inline bool rt_is_expired(const struct rtable *rth) 424 { 425 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 426 } 427 428 void rt_cache_flush(struct net *net) 429 { 430 rt_genid_bump_ipv4(net); 431 } 432 433 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 434 struct sk_buff *skb, 435 const void *daddr) 436 { 437 struct net_device *dev = dst->dev; 438 const __be32 *pkey = daddr; 439 const struct rtable *rt; 440 struct neighbour *n; 441 442 rt = (const struct rtable *) dst; 443 if (rt->rt_gateway) 444 pkey = (const __be32 *) &rt->rt_gateway; 445 else if (skb) 446 pkey = &ip_hdr(skb)->daddr; 447 448 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey); 449 if (n) 450 return n; 451 return neigh_create(&arp_tbl, pkey, dev); 452 } 453 454 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 455 { 456 struct net_device *dev = dst->dev; 457 const __be32 *pkey = daddr; 458 const struct rtable *rt; 459 460 rt = (const struct rtable *)dst; 461 if (rt->rt_gateway) 462 pkey = (const __be32 *)&rt->rt_gateway; 463 else if (!daddr || 464 (rt->rt_flags & 465 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) 466 return; 467 468 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 469 } 470 471 #define IP_IDENTS_SZ 2048u 472 473 static atomic_t *ip_idents __read_mostly; 474 static u32 *ip_tstamps __read_mostly; 475 476 /* In order to protect privacy, we add a perturbation to identifiers 477 * if one generator is seldom used. This makes hard for an attacker 478 * to infer how many packets were sent between two points in time. 479 */ 480 u32 ip_idents_reserve(u32 hash, int segs) 481 { 482 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; 483 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; 484 u32 old = READ_ONCE(*p_tstamp); 485 u32 now = (u32)jiffies; 486 u32 new, delta = 0; 487 488 if (old != now && cmpxchg(p_tstamp, old, now) == old) 489 delta = prandom_u32_max(now - old); 490 491 /* Do not use atomic_add_return() as it makes UBSAN unhappy */ 492 do { 493 old = (u32)atomic_read(p_id); 494 new = old + delta + segs; 495 } while (atomic_cmpxchg(p_id, old, new) != old); 496 497 return new - segs; 498 } 499 EXPORT_SYMBOL(ip_idents_reserve); 500 501 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 502 { 503 static u32 ip_idents_hashrnd __read_mostly; 504 u32 hash, id; 505 506 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd)); 507 508 hash = jhash_3words((__force u32)iph->daddr, 509 (__force u32)iph->saddr, 510 iph->protocol ^ net_hash_mix(net), 511 ip_idents_hashrnd); 512 id = ip_idents_reserve(hash, segs); 513 iph->id = htons(id); 514 } 515 EXPORT_SYMBOL(__ip_select_ident); 516 517 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 518 const struct sock *sk, 519 const struct iphdr *iph, 520 int oif, u8 tos, 521 u8 prot, u32 mark, int flow_flags) 522 { 523 if (sk) { 524 const struct inet_sock *inet = inet_sk(sk); 525 526 oif = sk->sk_bound_dev_if; 527 mark = sk->sk_mark; 528 tos = RT_CONN_FLAGS(sk); 529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 530 } 531 flowi4_init_output(fl4, oif, mark, tos, 532 RT_SCOPE_UNIVERSE, prot, 533 flow_flags, 534 iph->daddr, iph->saddr, 0, 0, 535 sock_net_uid(net, sk)); 536 } 537 538 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 539 const struct sock *sk) 540 { 541 const struct net *net = dev_net(skb->dev); 542 const struct iphdr *iph = ip_hdr(skb); 543 int oif = skb->dev->ifindex; 544 u8 tos = RT_TOS(iph->tos); 545 u8 prot = iph->protocol; 546 u32 mark = skb->mark; 547 548 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 549 } 550 551 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 552 { 553 const struct inet_sock *inet = inet_sk(sk); 554 const struct ip_options_rcu *inet_opt; 555 __be32 daddr = inet->inet_daddr; 556 557 rcu_read_lock(); 558 inet_opt = rcu_dereference(inet->inet_opt); 559 if (inet_opt && inet_opt->opt.srr) 560 daddr = inet_opt->opt.faddr; 561 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 562 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 563 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 564 inet_sk_flowi_flags(sk), 565 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 566 rcu_read_unlock(); 567 } 568 569 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 570 const struct sk_buff *skb) 571 { 572 if (skb) 573 build_skb_flow_key(fl4, skb, sk); 574 else 575 build_sk_flow_key(fl4, sk); 576 } 577 578 static DEFINE_SPINLOCK(fnhe_lock); 579 580 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 581 { 582 struct rtable *rt; 583 584 rt = rcu_dereference(fnhe->fnhe_rth_input); 585 if (rt) { 586 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 587 dst_dev_put(&rt->dst); 588 dst_release(&rt->dst); 589 } 590 rt = rcu_dereference(fnhe->fnhe_rth_output); 591 if (rt) { 592 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 593 dst_dev_put(&rt->dst); 594 dst_release(&rt->dst); 595 } 596 } 597 598 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 599 { 600 struct fib_nh_exception *fnhe, *oldest; 601 602 oldest = rcu_dereference(hash->chain); 603 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 604 fnhe = rcu_dereference(fnhe->fnhe_next)) { 605 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 606 oldest = fnhe; 607 } 608 fnhe_flush_routes(oldest); 609 return oldest; 610 } 611 612 static inline u32 fnhe_hashfun(__be32 daddr) 613 { 614 static u32 fnhe_hashrnd __read_mostly; 615 u32 hval; 616 617 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 618 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 619 return hash_32(hval, FNHE_HASH_SHIFT); 620 } 621 622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 623 { 624 rt->rt_pmtu = fnhe->fnhe_pmtu; 625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 626 rt->dst.expires = fnhe->fnhe_expires; 627 628 if (fnhe->fnhe_gw) { 629 rt->rt_flags |= RTCF_REDIRECTED; 630 rt->rt_gateway = fnhe->fnhe_gw; 631 rt->rt_uses_gateway = 1; 632 } 633 } 634 635 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 636 u32 pmtu, bool lock, unsigned long expires) 637 { 638 struct fnhe_hash_bucket *hash; 639 struct fib_nh_exception *fnhe; 640 struct rtable *rt; 641 u32 genid, hval; 642 unsigned int i; 643 int depth; 644 645 genid = fnhe_genid(dev_net(nh->nh_dev)); 646 hval = fnhe_hashfun(daddr); 647 648 spin_lock_bh(&fnhe_lock); 649 650 hash = rcu_dereference(nh->nh_exceptions); 651 if (!hash) { 652 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 653 if (!hash) 654 goto out_unlock; 655 rcu_assign_pointer(nh->nh_exceptions, hash); 656 } 657 658 hash += hval; 659 660 depth = 0; 661 for (fnhe = rcu_dereference(hash->chain); fnhe; 662 fnhe = rcu_dereference(fnhe->fnhe_next)) { 663 if (fnhe->fnhe_daddr == daddr) 664 break; 665 depth++; 666 } 667 668 if (fnhe) { 669 if (fnhe->fnhe_genid != genid) 670 fnhe->fnhe_genid = genid; 671 if (gw) 672 fnhe->fnhe_gw = gw; 673 if (pmtu) { 674 fnhe->fnhe_pmtu = pmtu; 675 fnhe->fnhe_mtu_locked = lock; 676 } 677 fnhe->fnhe_expires = max(1UL, expires); 678 /* Update all cached dsts too */ 679 rt = rcu_dereference(fnhe->fnhe_rth_input); 680 if (rt) 681 fill_route_from_fnhe(rt, fnhe); 682 rt = rcu_dereference(fnhe->fnhe_rth_output); 683 if (rt) 684 fill_route_from_fnhe(rt, fnhe); 685 } else { 686 if (depth > FNHE_RECLAIM_DEPTH) 687 fnhe = fnhe_oldest(hash); 688 else { 689 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 690 if (!fnhe) 691 goto out_unlock; 692 693 fnhe->fnhe_next = hash->chain; 694 rcu_assign_pointer(hash->chain, fnhe); 695 } 696 fnhe->fnhe_genid = genid; 697 fnhe->fnhe_daddr = daddr; 698 fnhe->fnhe_gw = gw; 699 fnhe->fnhe_pmtu = pmtu; 700 fnhe->fnhe_mtu_locked = lock; 701 fnhe->fnhe_expires = max(1UL, expires); 702 703 /* Exception created; mark the cached routes for the nexthop 704 * stale, so anyone caching it rechecks if this exception 705 * applies to them. 706 */ 707 rt = rcu_dereference(nh->nh_rth_input); 708 if (rt) 709 rt->dst.obsolete = DST_OBSOLETE_KILL; 710 711 for_each_possible_cpu(i) { 712 struct rtable __rcu **prt; 713 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 714 rt = rcu_dereference(*prt); 715 if (rt) 716 rt->dst.obsolete = DST_OBSOLETE_KILL; 717 } 718 } 719 720 fnhe->fnhe_stamp = jiffies; 721 722 out_unlock: 723 spin_unlock_bh(&fnhe_lock); 724 } 725 726 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 727 bool kill_route) 728 { 729 __be32 new_gw = icmp_hdr(skb)->un.gateway; 730 __be32 old_gw = ip_hdr(skb)->saddr; 731 struct net_device *dev = skb->dev; 732 struct in_device *in_dev; 733 struct fib_result res; 734 struct neighbour *n; 735 struct net *net; 736 737 switch (icmp_hdr(skb)->code & 7) { 738 case ICMP_REDIR_NET: 739 case ICMP_REDIR_NETTOS: 740 case ICMP_REDIR_HOST: 741 case ICMP_REDIR_HOSTTOS: 742 break; 743 744 default: 745 return; 746 } 747 748 if (rt->rt_gateway != old_gw) 749 return; 750 751 in_dev = __in_dev_get_rcu(dev); 752 if (!in_dev) 753 return; 754 755 net = dev_net(dev); 756 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 757 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 758 ipv4_is_zeronet(new_gw)) 759 goto reject_redirect; 760 761 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 762 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 763 goto reject_redirect; 764 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 765 goto reject_redirect; 766 } else { 767 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 768 goto reject_redirect; 769 } 770 771 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 772 if (!n) 773 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 774 if (!IS_ERR(n)) { 775 if (!(n->nud_state & NUD_VALID)) { 776 neigh_event_send(n, NULL); 777 } else { 778 if (fib_lookup(net, fl4, &res, 0) == 0) { 779 struct fib_nh *nh = &FIB_RES_NH(res); 780 781 update_or_create_fnhe(nh, fl4->daddr, new_gw, 782 0, false, 783 jiffies + ip_rt_gc_timeout); 784 } 785 if (kill_route) 786 rt->dst.obsolete = DST_OBSOLETE_KILL; 787 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 788 } 789 neigh_release(n); 790 } 791 return; 792 793 reject_redirect: 794 #ifdef CONFIG_IP_ROUTE_VERBOSE 795 if (IN_DEV_LOG_MARTIANS(in_dev)) { 796 const struct iphdr *iph = (const struct iphdr *) skb->data; 797 __be32 daddr = iph->daddr; 798 __be32 saddr = iph->saddr; 799 800 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 801 " Advised path = %pI4 -> %pI4\n", 802 &old_gw, dev->name, &new_gw, 803 &saddr, &daddr); 804 } 805 #endif 806 ; 807 } 808 809 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 810 { 811 struct rtable *rt; 812 struct flowi4 fl4; 813 const struct iphdr *iph = (const struct iphdr *) skb->data; 814 struct net *net = dev_net(skb->dev); 815 int oif = skb->dev->ifindex; 816 u8 tos = RT_TOS(iph->tos); 817 u8 prot = iph->protocol; 818 u32 mark = skb->mark; 819 820 rt = (struct rtable *) dst; 821 822 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 823 __ip_do_redirect(rt, skb, &fl4, true); 824 } 825 826 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 827 { 828 struct rtable *rt = (struct rtable *)dst; 829 struct dst_entry *ret = dst; 830 831 if (rt) { 832 if (dst->obsolete > 0) { 833 ip_rt_put(rt); 834 ret = NULL; 835 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 836 rt->dst.expires) { 837 ip_rt_put(rt); 838 ret = NULL; 839 } 840 } 841 return ret; 842 } 843 844 /* 845 * Algorithm: 846 * 1. The first ip_rt_redirect_number redirects are sent 847 * with exponential backoff, then we stop sending them at all, 848 * assuming that the host ignores our redirects. 849 * 2. If we did not see packets requiring redirects 850 * during ip_rt_redirect_silence, we assume that the host 851 * forgot redirected route and start to send redirects again. 852 * 853 * This algorithm is much cheaper and more intelligent than dumb load limiting 854 * in icmp.c. 855 * 856 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 857 * and "frag. need" (breaks PMTU discovery) in icmp.c. 858 */ 859 860 void ip_rt_send_redirect(struct sk_buff *skb) 861 { 862 struct rtable *rt = skb_rtable(skb); 863 struct in_device *in_dev; 864 struct inet_peer *peer; 865 struct net *net; 866 int log_martians; 867 int vif; 868 869 rcu_read_lock(); 870 in_dev = __in_dev_get_rcu(rt->dst.dev); 871 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 872 rcu_read_unlock(); 873 return; 874 } 875 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 876 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 877 rcu_read_unlock(); 878 879 net = dev_net(rt->dst.dev); 880 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 881 if (!peer) { 882 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 883 rt_nexthop(rt, ip_hdr(skb)->daddr)); 884 return; 885 } 886 887 /* No redirected packets during ip_rt_redirect_silence; 888 * reset the algorithm. 889 */ 890 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 891 peer->rate_tokens = 0; 892 peer->n_redirects = 0; 893 } 894 895 /* Too many ignored redirects; do not send anything 896 * set dst.rate_last to the last seen redirected packet. 897 */ 898 if (peer->n_redirects >= ip_rt_redirect_number) { 899 peer->rate_last = jiffies; 900 goto out_put_peer; 901 } 902 903 /* Check for load limit; set rate_last to the latest sent 904 * redirect. 905 */ 906 if (peer->rate_tokens == 0 || 907 time_after(jiffies, 908 (peer->rate_last + 909 (ip_rt_redirect_load << peer->rate_tokens)))) { 910 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 911 912 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 913 peer->rate_last = jiffies; 914 ++peer->rate_tokens; 915 ++peer->n_redirects; 916 #ifdef CONFIG_IP_ROUTE_VERBOSE 917 if (log_martians && 918 peer->rate_tokens == ip_rt_redirect_number) 919 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 920 &ip_hdr(skb)->saddr, inet_iif(skb), 921 &ip_hdr(skb)->daddr, &gw); 922 #endif 923 } 924 out_put_peer: 925 inet_putpeer(peer); 926 } 927 928 static int ip_error(struct sk_buff *skb) 929 { 930 struct rtable *rt = skb_rtable(skb); 931 struct net_device *dev = skb->dev; 932 struct in_device *in_dev; 933 struct inet_peer *peer; 934 unsigned long now; 935 struct net *net; 936 bool send; 937 int code; 938 939 if (netif_is_l3_master(skb->dev)) { 940 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 941 if (!dev) 942 goto out; 943 } 944 945 in_dev = __in_dev_get_rcu(dev); 946 947 /* IP on this device is disabled. */ 948 if (!in_dev) 949 goto out; 950 951 net = dev_net(rt->dst.dev); 952 if (!IN_DEV_FORWARD(in_dev)) { 953 switch (rt->dst.error) { 954 case EHOSTUNREACH: 955 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 956 break; 957 958 case ENETUNREACH: 959 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 960 break; 961 } 962 goto out; 963 } 964 965 switch (rt->dst.error) { 966 case EINVAL: 967 default: 968 goto out; 969 case EHOSTUNREACH: 970 code = ICMP_HOST_UNREACH; 971 break; 972 case ENETUNREACH: 973 code = ICMP_NET_UNREACH; 974 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 975 break; 976 case EACCES: 977 code = ICMP_PKT_FILTERED; 978 break; 979 } 980 981 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 982 l3mdev_master_ifindex(skb->dev), 1); 983 984 send = true; 985 if (peer) { 986 now = jiffies; 987 peer->rate_tokens += now - peer->rate_last; 988 if (peer->rate_tokens > ip_rt_error_burst) 989 peer->rate_tokens = ip_rt_error_burst; 990 peer->rate_last = now; 991 if (peer->rate_tokens >= ip_rt_error_cost) 992 peer->rate_tokens -= ip_rt_error_cost; 993 else 994 send = false; 995 inet_putpeer(peer); 996 } 997 if (send) 998 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 999 1000 out: kfree_skb(skb); 1001 return 0; 1002 } 1003 1004 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1005 { 1006 struct dst_entry *dst = &rt->dst; 1007 u32 old_mtu = ipv4_mtu(dst); 1008 struct fib_result res; 1009 bool lock = false; 1010 1011 if (ip_mtu_locked(dst)) 1012 return; 1013 1014 if (old_mtu < mtu) 1015 return; 1016 1017 if (mtu < ip_rt_min_pmtu) { 1018 lock = true; 1019 mtu = min(old_mtu, ip_rt_min_pmtu); 1020 } 1021 1022 if (rt->rt_pmtu == mtu && !lock && 1023 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 1024 return; 1025 1026 rcu_read_lock(); 1027 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) { 1028 struct fib_nh *nh = &FIB_RES_NH(res); 1029 1030 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock, 1031 jiffies + ip_rt_mtu_expires); 1032 } 1033 rcu_read_unlock(); 1034 } 1035 1036 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1037 struct sk_buff *skb, u32 mtu) 1038 { 1039 struct rtable *rt = (struct rtable *) dst; 1040 struct flowi4 fl4; 1041 1042 ip_rt_build_flow_key(&fl4, sk, skb); 1043 __ip_rt_update_pmtu(rt, &fl4, mtu); 1044 } 1045 1046 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1047 int oif, u8 protocol) 1048 { 1049 const struct iphdr *iph = (const struct iphdr *) skb->data; 1050 struct flowi4 fl4; 1051 struct rtable *rt; 1052 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1053 1054 __build_flow_key(net, &fl4, NULL, iph, oif, 1055 RT_TOS(iph->tos), protocol, mark, 0); 1056 rt = __ip_route_output_key(net, &fl4); 1057 if (!IS_ERR(rt)) { 1058 __ip_rt_update_pmtu(rt, &fl4, mtu); 1059 ip_rt_put(rt); 1060 } 1061 } 1062 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1063 1064 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1065 { 1066 const struct iphdr *iph = (const struct iphdr *) skb->data; 1067 struct flowi4 fl4; 1068 struct rtable *rt; 1069 1070 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1071 1072 if (!fl4.flowi4_mark) 1073 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1074 1075 rt = __ip_route_output_key(sock_net(sk), &fl4); 1076 if (!IS_ERR(rt)) { 1077 __ip_rt_update_pmtu(rt, &fl4, mtu); 1078 ip_rt_put(rt); 1079 } 1080 } 1081 1082 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1083 { 1084 const struct iphdr *iph = (const struct iphdr *) skb->data; 1085 struct flowi4 fl4; 1086 struct rtable *rt; 1087 struct dst_entry *odst = NULL; 1088 bool new = false; 1089 struct net *net = sock_net(sk); 1090 1091 bh_lock_sock(sk); 1092 1093 if (!ip_sk_accept_pmtu(sk)) 1094 goto out; 1095 1096 odst = sk_dst_get(sk); 1097 1098 if (sock_owned_by_user(sk) || !odst) { 1099 __ipv4_sk_update_pmtu(skb, sk, mtu); 1100 goto out; 1101 } 1102 1103 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1104 1105 rt = (struct rtable *)odst; 1106 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1107 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1108 if (IS_ERR(rt)) 1109 goto out; 1110 1111 new = true; 1112 } 1113 1114 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu); 1115 1116 if (!dst_check(&rt->dst, 0)) { 1117 if (new) 1118 dst_release(&rt->dst); 1119 1120 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1121 if (IS_ERR(rt)) 1122 goto out; 1123 1124 new = true; 1125 } 1126 1127 if (new) 1128 sk_dst_set(sk, &rt->dst); 1129 1130 out: 1131 bh_unlock_sock(sk); 1132 dst_release(odst); 1133 } 1134 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1135 1136 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1137 int oif, u8 protocol) 1138 { 1139 const struct iphdr *iph = (const struct iphdr *) skb->data; 1140 struct flowi4 fl4; 1141 struct rtable *rt; 1142 1143 __build_flow_key(net, &fl4, NULL, iph, oif, 1144 RT_TOS(iph->tos), protocol, 0, 0); 1145 rt = __ip_route_output_key(net, &fl4); 1146 if (!IS_ERR(rt)) { 1147 __ip_do_redirect(rt, skb, &fl4, false); 1148 ip_rt_put(rt); 1149 } 1150 } 1151 EXPORT_SYMBOL_GPL(ipv4_redirect); 1152 1153 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1154 { 1155 const struct iphdr *iph = (const struct iphdr *) skb->data; 1156 struct flowi4 fl4; 1157 struct rtable *rt; 1158 struct net *net = sock_net(sk); 1159 1160 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1161 rt = __ip_route_output_key(net, &fl4); 1162 if (!IS_ERR(rt)) { 1163 __ip_do_redirect(rt, skb, &fl4, false); 1164 ip_rt_put(rt); 1165 } 1166 } 1167 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1168 1169 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1170 { 1171 struct rtable *rt = (struct rtable *) dst; 1172 1173 /* All IPV4 dsts are created with ->obsolete set to the value 1174 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1175 * into this function always. 1176 * 1177 * When a PMTU/redirect information update invalidates a route, 1178 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1179 * DST_OBSOLETE_DEAD by dst_free(). 1180 */ 1181 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1182 return NULL; 1183 return dst; 1184 } 1185 1186 static void ipv4_link_failure(struct sk_buff *skb) 1187 { 1188 struct rtable *rt; 1189 1190 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1191 1192 rt = skb_rtable(skb); 1193 if (rt) 1194 dst_set_expires(&rt->dst, 0); 1195 } 1196 1197 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1198 { 1199 pr_debug("%s: %pI4 -> %pI4, %s\n", 1200 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1201 skb->dev ? skb->dev->name : "?"); 1202 kfree_skb(skb); 1203 WARN_ON(1); 1204 return 0; 1205 } 1206 1207 /* 1208 We do not cache source address of outgoing interface, 1209 because it is used only by IP RR, TS and SRR options, 1210 so that it out of fast path. 1211 1212 BTW remember: "addr" is allowed to be not aligned 1213 in IP options! 1214 */ 1215 1216 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1217 { 1218 __be32 src; 1219 1220 if (rt_is_output_route(rt)) 1221 src = ip_hdr(skb)->saddr; 1222 else { 1223 struct fib_result res; 1224 struct iphdr *iph = ip_hdr(skb); 1225 struct flowi4 fl4 = { 1226 .daddr = iph->daddr, 1227 .saddr = iph->saddr, 1228 .flowi4_tos = RT_TOS(iph->tos), 1229 .flowi4_oif = rt->dst.dev->ifindex, 1230 .flowi4_iif = skb->dev->ifindex, 1231 .flowi4_mark = skb->mark, 1232 }; 1233 1234 rcu_read_lock(); 1235 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1236 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1237 else 1238 src = inet_select_addr(rt->dst.dev, 1239 rt_nexthop(rt, iph->daddr), 1240 RT_SCOPE_UNIVERSE); 1241 rcu_read_unlock(); 1242 } 1243 memcpy(addr, &src, 4); 1244 } 1245 1246 #ifdef CONFIG_IP_ROUTE_CLASSID 1247 static void set_class_tag(struct rtable *rt, u32 tag) 1248 { 1249 if (!(rt->dst.tclassid & 0xFFFF)) 1250 rt->dst.tclassid |= tag & 0xFFFF; 1251 if (!(rt->dst.tclassid & 0xFFFF0000)) 1252 rt->dst.tclassid |= tag & 0xFFFF0000; 1253 } 1254 #endif 1255 1256 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1257 { 1258 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1259 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1260 ip_rt_min_advmss); 1261 1262 return min(advmss, IPV4_MAX_PMTU - header_size); 1263 } 1264 1265 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1266 { 1267 const struct rtable *rt = (const struct rtable *) dst; 1268 unsigned int mtu = rt->rt_pmtu; 1269 1270 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1271 mtu = dst_metric_raw(dst, RTAX_MTU); 1272 1273 if (mtu) 1274 return mtu; 1275 1276 mtu = READ_ONCE(dst->dev->mtu); 1277 1278 if (unlikely(ip_mtu_locked(dst))) { 1279 if (rt->rt_uses_gateway && mtu > 576) 1280 mtu = 576; 1281 } 1282 1283 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1284 1285 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1286 } 1287 1288 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr) 1289 { 1290 struct fnhe_hash_bucket *hash; 1291 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1292 u32 hval = fnhe_hashfun(daddr); 1293 1294 spin_lock_bh(&fnhe_lock); 1295 1296 hash = rcu_dereference_protected(nh->nh_exceptions, 1297 lockdep_is_held(&fnhe_lock)); 1298 hash += hval; 1299 1300 fnhe_p = &hash->chain; 1301 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1302 while (fnhe) { 1303 if (fnhe->fnhe_daddr == daddr) { 1304 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1305 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1306 fnhe_flush_routes(fnhe); 1307 kfree_rcu(fnhe, rcu); 1308 break; 1309 } 1310 fnhe_p = &fnhe->fnhe_next; 1311 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1312 lockdep_is_held(&fnhe_lock)); 1313 } 1314 1315 spin_unlock_bh(&fnhe_lock); 1316 } 1317 1318 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1319 { 1320 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1321 struct fib_nh_exception *fnhe; 1322 u32 hval; 1323 1324 if (!hash) 1325 return NULL; 1326 1327 hval = fnhe_hashfun(daddr); 1328 1329 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1330 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1331 if (fnhe->fnhe_daddr == daddr) { 1332 if (fnhe->fnhe_expires && 1333 time_after(jiffies, fnhe->fnhe_expires)) { 1334 ip_del_fnhe(nh, daddr); 1335 break; 1336 } 1337 return fnhe; 1338 } 1339 } 1340 return NULL; 1341 } 1342 1343 /* MTU selection: 1344 * 1. mtu on route is locked - use it 1345 * 2. mtu from nexthop exception 1346 * 3. mtu from egress device 1347 */ 1348 1349 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1350 { 1351 struct fib_info *fi = res->fi; 1352 struct fib_nh *nh = &fi->fib_nh[res->nh_sel]; 1353 struct net_device *dev = nh->nh_dev; 1354 u32 mtu = 0; 1355 1356 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1357 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1358 mtu = fi->fib_mtu; 1359 1360 if (likely(!mtu)) { 1361 struct fib_nh_exception *fnhe; 1362 1363 fnhe = find_exception(nh, daddr); 1364 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1365 mtu = fnhe->fnhe_pmtu; 1366 } 1367 1368 if (likely(!mtu)) 1369 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1370 1371 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu); 1372 } 1373 1374 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1375 __be32 daddr, const bool do_cache) 1376 { 1377 bool ret = false; 1378 1379 spin_lock_bh(&fnhe_lock); 1380 1381 if (daddr == fnhe->fnhe_daddr) { 1382 struct rtable __rcu **porig; 1383 struct rtable *orig; 1384 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1385 1386 if (rt_is_input_route(rt)) 1387 porig = &fnhe->fnhe_rth_input; 1388 else 1389 porig = &fnhe->fnhe_rth_output; 1390 orig = rcu_dereference(*porig); 1391 1392 if (fnhe->fnhe_genid != genid) { 1393 fnhe->fnhe_genid = genid; 1394 fnhe->fnhe_gw = 0; 1395 fnhe->fnhe_pmtu = 0; 1396 fnhe->fnhe_expires = 0; 1397 fnhe->fnhe_mtu_locked = false; 1398 fnhe_flush_routes(fnhe); 1399 orig = NULL; 1400 } 1401 fill_route_from_fnhe(rt, fnhe); 1402 if (!rt->rt_gateway) 1403 rt->rt_gateway = daddr; 1404 1405 if (do_cache) { 1406 dst_hold(&rt->dst); 1407 rcu_assign_pointer(*porig, rt); 1408 if (orig) { 1409 dst_dev_put(&orig->dst); 1410 dst_release(&orig->dst); 1411 } 1412 ret = true; 1413 } 1414 1415 fnhe->fnhe_stamp = jiffies; 1416 } 1417 spin_unlock_bh(&fnhe_lock); 1418 1419 return ret; 1420 } 1421 1422 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1423 { 1424 struct rtable *orig, *prev, **p; 1425 bool ret = true; 1426 1427 if (rt_is_input_route(rt)) { 1428 p = (struct rtable **)&nh->nh_rth_input; 1429 } else { 1430 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1431 } 1432 orig = *p; 1433 1434 /* hold dst before doing cmpxchg() to avoid race condition 1435 * on this dst 1436 */ 1437 dst_hold(&rt->dst); 1438 prev = cmpxchg(p, orig, rt); 1439 if (prev == orig) { 1440 if (orig) { 1441 dst_dev_put(&orig->dst); 1442 dst_release(&orig->dst); 1443 } 1444 } else { 1445 dst_release(&rt->dst); 1446 ret = false; 1447 } 1448 1449 return ret; 1450 } 1451 1452 struct uncached_list { 1453 spinlock_t lock; 1454 struct list_head head; 1455 }; 1456 1457 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1458 1459 void rt_add_uncached_list(struct rtable *rt) 1460 { 1461 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1462 1463 rt->rt_uncached_list = ul; 1464 1465 spin_lock_bh(&ul->lock); 1466 list_add_tail(&rt->rt_uncached, &ul->head); 1467 spin_unlock_bh(&ul->lock); 1468 } 1469 1470 void rt_del_uncached_list(struct rtable *rt) 1471 { 1472 if (!list_empty(&rt->rt_uncached)) { 1473 struct uncached_list *ul = rt->rt_uncached_list; 1474 1475 spin_lock_bh(&ul->lock); 1476 list_del(&rt->rt_uncached); 1477 spin_unlock_bh(&ul->lock); 1478 } 1479 } 1480 1481 static void ipv4_dst_destroy(struct dst_entry *dst) 1482 { 1483 struct rtable *rt = (struct rtable *)dst; 1484 1485 ip_dst_metrics_put(dst); 1486 rt_del_uncached_list(rt); 1487 } 1488 1489 void rt_flush_dev(struct net_device *dev) 1490 { 1491 struct net *net = dev_net(dev); 1492 struct rtable *rt; 1493 int cpu; 1494 1495 for_each_possible_cpu(cpu) { 1496 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1497 1498 spin_lock_bh(&ul->lock); 1499 list_for_each_entry(rt, &ul->head, rt_uncached) { 1500 if (rt->dst.dev != dev) 1501 continue; 1502 rt->dst.dev = net->loopback_dev; 1503 dev_hold(rt->dst.dev); 1504 dev_put(dev); 1505 } 1506 spin_unlock_bh(&ul->lock); 1507 } 1508 } 1509 1510 static bool rt_cache_valid(const struct rtable *rt) 1511 { 1512 return rt && 1513 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1514 !rt_is_expired(rt); 1515 } 1516 1517 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1518 const struct fib_result *res, 1519 struct fib_nh_exception *fnhe, 1520 struct fib_info *fi, u16 type, u32 itag, 1521 const bool do_cache) 1522 { 1523 bool cached = false; 1524 1525 if (fi) { 1526 struct fib_nh *nh = &FIB_RES_NH(*res); 1527 1528 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) { 1529 rt->rt_gateway = nh->nh_gw; 1530 rt->rt_uses_gateway = 1; 1531 } 1532 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1533 1534 #ifdef CONFIG_IP_ROUTE_CLASSID 1535 rt->dst.tclassid = nh->nh_tclassid; 1536 #endif 1537 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 1538 if (unlikely(fnhe)) 1539 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1540 else if (do_cache) 1541 cached = rt_cache_route(nh, rt); 1542 if (unlikely(!cached)) { 1543 /* Routes we intend to cache in nexthop exception or 1544 * FIB nexthop have the DST_NOCACHE bit clear. 1545 * However, if we are unsuccessful at storing this 1546 * route into the cache we really need to set it. 1547 */ 1548 if (!rt->rt_gateway) 1549 rt->rt_gateway = daddr; 1550 rt_add_uncached_list(rt); 1551 } 1552 } else 1553 rt_add_uncached_list(rt); 1554 1555 #ifdef CONFIG_IP_ROUTE_CLASSID 1556 #ifdef CONFIG_IP_MULTIPLE_TABLES 1557 set_class_tag(rt, res->tclassid); 1558 #endif 1559 set_class_tag(rt, itag); 1560 #endif 1561 } 1562 1563 struct rtable *rt_dst_alloc(struct net_device *dev, 1564 unsigned int flags, u16 type, 1565 bool nopolicy, bool noxfrm, bool will_cache) 1566 { 1567 struct rtable *rt; 1568 1569 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1570 (will_cache ? 0 : DST_HOST) | 1571 (nopolicy ? DST_NOPOLICY : 0) | 1572 (noxfrm ? DST_NOXFRM : 0)); 1573 1574 if (rt) { 1575 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1576 rt->rt_flags = flags; 1577 rt->rt_type = type; 1578 rt->rt_is_input = 0; 1579 rt->rt_iif = 0; 1580 rt->rt_pmtu = 0; 1581 rt->rt_mtu_locked = 0; 1582 rt->rt_gateway = 0; 1583 rt->rt_uses_gateway = 0; 1584 INIT_LIST_HEAD(&rt->rt_uncached); 1585 1586 rt->dst.output = ip_output; 1587 if (flags & RTCF_LOCAL) 1588 rt->dst.input = ip_local_deliver; 1589 } 1590 1591 return rt; 1592 } 1593 EXPORT_SYMBOL(rt_dst_alloc); 1594 1595 /* called in rcu_read_lock() section */ 1596 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1597 u8 tos, struct net_device *dev, 1598 struct in_device *in_dev, u32 *itag) 1599 { 1600 int err; 1601 1602 /* Primary sanity checks. */ 1603 if (!in_dev) 1604 return -EINVAL; 1605 1606 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1607 skb->protocol != htons(ETH_P_IP)) 1608 return -EINVAL; 1609 1610 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1611 return -EINVAL; 1612 1613 if (ipv4_is_zeronet(saddr)) { 1614 if (!ipv4_is_local_multicast(daddr) && 1615 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1616 return -EINVAL; 1617 } else { 1618 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1619 in_dev, itag); 1620 if (err < 0) 1621 return err; 1622 } 1623 return 0; 1624 } 1625 1626 /* called in rcu_read_lock() section */ 1627 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1628 u8 tos, struct net_device *dev, int our) 1629 { 1630 struct in_device *in_dev = __in_dev_get_rcu(dev); 1631 unsigned int flags = RTCF_MULTICAST; 1632 struct rtable *rth; 1633 u32 itag = 0; 1634 int err; 1635 1636 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1637 if (err) 1638 return err; 1639 1640 if (our) 1641 flags |= RTCF_LOCAL; 1642 1643 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1644 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1645 if (!rth) 1646 return -ENOBUFS; 1647 1648 #ifdef CONFIG_IP_ROUTE_CLASSID 1649 rth->dst.tclassid = itag; 1650 #endif 1651 rth->dst.output = ip_rt_bug; 1652 rth->rt_is_input= 1; 1653 1654 #ifdef CONFIG_IP_MROUTE 1655 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1656 rth->dst.input = ip_mr_input; 1657 #endif 1658 RT_CACHE_STAT_INC(in_slow_mc); 1659 1660 skb_dst_set(skb, &rth->dst); 1661 return 0; 1662 } 1663 1664 1665 static void ip_handle_martian_source(struct net_device *dev, 1666 struct in_device *in_dev, 1667 struct sk_buff *skb, 1668 __be32 daddr, 1669 __be32 saddr) 1670 { 1671 RT_CACHE_STAT_INC(in_martian_src); 1672 #ifdef CONFIG_IP_ROUTE_VERBOSE 1673 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1674 /* 1675 * RFC1812 recommendation, if source is martian, 1676 * the only hint is MAC header. 1677 */ 1678 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1679 &daddr, &saddr, dev->name); 1680 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1681 print_hex_dump(KERN_WARNING, "ll header: ", 1682 DUMP_PREFIX_OFFSET, 16, 1, 1683 skb_mac_header(skb), 1684 dev->hard_header_len, false); 1685 } 1686 } 1687 #endif 1688 } 1689 1690 /* called in rcu_read_lock() section */ 1691 static int __mkroute_input(struct sk_buff *skb, 1692 const struct fib_result *res, 1693 struct in_device *in_dev, 1694 __be32 daddr, __be32 saddr, u32 tos) 1695 { 1696 struct fib_nh_exception *fnhe; 1697 struct rtable *rth; 1698 int err; 1699 struct in_device *out_dev; 1700 bool do_cache; 1701 u32 itag = 0; 1702 1703 /* get a working reference to the output device */ 1704 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1705 if (!out_dev) { 1706 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1707 return -EINVAL; 1708 } 1709 1710 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1711 in_dev->dev, in_dev, &itag); 1712 if (err < 0) { 1713 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1714 saddr); 1715 1716 goto cleanup; 1717 } 1718 1719 do_cache = res->fi && !itag; 1720 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1721 skb->protocol == htons(ETH_P_IP) && 1722 (IN_DEV_SHARED_MEDIA(out_dev) || 1723 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1724 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1725 1726 if (skb->protocol != htons(ETH_P_IP)) { 1727 /* Not IP (i.e. ARP). Do not create route, if it is 1728 * invalid for proxy arp. DNAT routes are always valid. 1729 * 1730 * Proxy arp feature have been extended to allow, ARP 1731 * replies back to the same interface, to support 1732 * Private VLAN switch technologies. See arp.c. 1733 */ 1734 if (out_dev == in_dev && 1735 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1736 err = -EINVAL; 1737 goto cleanup; 1738 } 1739 } 1740 1741 fnhe = find_exception(&FIB_RES_NH(*res), daddr); 1742 if (do_cache) { 1743 if (fnhe) 1744 rth = rcu_dereference(fnhe->fnhe_rth_input); 1745 else 1746 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 1747 if (rt_cache_valid(rth)) { 1748 skb_dst_set_noref(skb, &rth->dst); 1749 goto out; 1750 } 1751 } 1752 1753 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1754 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1755 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1756 if (!rth) { 1757 err = -ENOBUFS; 1758 goto cleanup; 1759 } 1760 1761 rth->rt_is_input = 1; 1762 RT_CACHE_STAT_INC(in_slow_tot); 1763 1764 rth->dst.input = ip_forward; 1765 1766 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1767 do_cache); 1768 lwtunnel_set_redirect(&rth->dst); 1769 skb_dst_set(skb, &rth->dst); 1770 out: 1771 err = 0; 1772 cleanup: 1773 return err; 1774 } 1775 1776 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1777 /* To make ICMP packets follow the right flow, the multipath hash is 1778 * calculated from the inner IP addresses. 1779 */ 1780 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1781 struct flow_keys *hash_keys) 1782 { 1783 const struct iphdr *outer_iph = ip_hdr(skb); 1784 const struct iphdr *key_iph = outer_iph; 1785 const struct iphdr *inner_iph; 1786 const struct icmphdr *icmph; 1787 struct iphdr _inner_iph; 1788 struct icmphdr _icmph; 1789 1790 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1791 goto out; 1792 1793 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1794 goto out; 1795 1796 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1797 &_icmph); 1798 if (!icmph) 1799 goto out; 1800 1801 if (icmph->type != ICMP_DEST_UNREACH && 1802 icmph->type != ICMP_REDIRECT && 1803 icmph->type != ICMP_TIME_EXCEEDED && 1804 icmph->type != ICMP_PARAMETERPROB) 1805 goto out; 1806 1807 inner_iph = skb_header_pointer(skb, 1808 outer_iph->ihl * 4 + sizeof(_icmph), 1809 sizeof(_inner_iph), &_inner_iph); 1810 if (!inner_iph) 1811 goto out; 1812 1813 key_iph = inner_iph; 1814 out: 1815 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1816 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1817 } 1818 1819 /* if skb is set it will be used and fl4 can be NULL */ 1820 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 1821 const struct sk_buff *skb, struct flow_keys *flkeys) 1822 { 1823 struct flow_keys hash_keys; 1824 u32 mhash; 1825 1826 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 1827 case 0: 1828 memset(&hash_keys, 0, sizeof(hash_keys)); 1829 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1830 if (skb) { 1831 ip_multipath_l3_keys(skb, &hash_keys); 1832 } else { 1833 hash_keys.addrs.v4addrs.src = fl4->saddr; 1834 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1835 } 1836 break; 1837 case 1: 1838 /* skb is currently provided only when forwarding */ 1839 if (skb) { 1840 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 1841 struct flow_keys keys; 1842 1843 /* short-circuit if we already have L4 hash present */ 1844 if (skb->l4_hash) 1845 return skb_get_hash_raw(skb) >> 1; 1846 1847 memset(&hash_keys, 0, sizeof(hash_keys)); 1848 1849 if (!flkeys) { 1850 skb_flow_dissect_flow_keys(skb, &keys, flag); 1851 flkeys = &keys; 1852 } 1853 1854 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1855 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 1856 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 1857 hash_keys.ports.src = flkeys->ports.src; 1858 hash_keys.ports.dst = flkeys->ports.dst; 1859 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 1860 } else { 1861 memset(&hash_keys, 0, sizeof(hash_keys)); 1862 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1863 hash_keys.addrs.v4addrs.src = fl4->saddr; 1864 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1865 hash_keys.ports.src = fl4->fl4_sport; 1866 hash_keys.ports.dst = fl4->fl4_dport; 1867 hash_keys.basic.ip_proto = fl4->flowi4_proto; 1868 } 1869 break; 1870 } 1871 mhash = flow_hash_from_keys(&hash_keys); 1872 1873 return mhash >> 1; 1874 } 1875 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1876 1877 static int ip_mkroute_input(struct sk_buff *skb, 1878 struct fib_result *res, 1879 struct in_device *in_dev, 1880 __be32 daddr, __be32 saddr, u32 tos, 1881 struct flow_keys *hkeys) 1882 { 1883 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1884 if (res->fi && res->fi->fib_nhs > 1) { 1885 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1886 1887 fib_select_multipath(res, h); 1888 } 1889 #endif 1890 1891 /* create a routing cache entry */ 1892 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1893 } 1894 1895 /* 1896 * NOTE. We drop all the packets that has local source 1897 * addresses, because every properly looped back packet 1898 * must have correct destination already attached by output routine. 1899 * 1900 * Such approach solves two big problems: 1901 * 1. Not simplex devices are handled properly. 1902 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1903 * called with rcu_read_lock() 1904 */ 1905 1906 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1907 u8 tos, struct net_device *dev, 1908 struct fib_result *res) 1909 { 1910 struct in_device *in_dev = __in_dev_get_rcu(dev); 1911 struct flow_keys *flkeys = NULL, _flkeys; 1912 struct net *net = dev_net(dev); 1913 struct ip_tunnel_info *tun_info; 1914 int err = -EINVAL; 1915 unsigned int flags = 0; 1916 u32 itag = 0; 1917 struct rtable *rth; 1918 struct flowi4 fl4; 1919 bool do_cache; 1920 1921 /* IP on this device is disabled. */ 1922 1923 if (!in_dev) 1924 goto out; 1925 1926 /* Check for the most weird martians, which can be not detected 1927 by fib_lookup. 1928 */ 1929 1930 tun_info = skb_tunnel_info(skb); 1931 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1932 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1933 else 1934 fl4.flowi4_tun_key.tun_id = 0; 1935 skb_dst_drop(skb); 1936 1937 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1938 goto martian_source; 1939 1940 res->fi = NULL; 1941 res->table = NULL; 1942 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1943 goto brd_input; 1944 1945 /* Accept zero addresses only to limited broadcast; 1946 * I even do not know to fix it or not. Waiting for complains :-) 1947 */ 1948 if (ipv4_is_zeronet(saddr)) 1949 goto martian_source; 1950 1951 if (ipv4_is_zeronet(daddr)) 1952 goto martian_destination; 1953 1954 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1955 * and call it once if daddr or/and saddr are loopback addresses 1956 */ 1957 if (ipv4_is_loopback(daddr)) { 1958 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1959 goto martian_destination; 1960 } else if (ipv4_is_loopback(saddr)) { 1961 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 1962 goto martian_source; 1963 } 1964 1965 /* 1966 * Now we are ready to route packet. 1967 */ 1968 fl4.flowi4_oif = 0; 1969 fl4.flowi4_iif = dev->ifindex; 1970 fl4.flowi4_mark = skb->mark; 1971 fl4.flowi4_tos = tos; 1972 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 1973 fl4.flowi4_flags = 0; 1974 fl4.daddr = daddr; 1975 fl4.saddr = saddr; 1976 fl4.flowi4_uid = sock_net_uid(net, NULL); 1977 1978 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 1979 flkeys = &_flkeys; 1980 } else { 1981 fl4.flowi4_proto = 0; 1982 fl4.fl4_sport = 0; 1983 fl4.fl4_dport = 0; 1984 } 1985 1986 err = fib_lookup(net, &fl4, res, 0); 1987 if (err != 0) { 1988 if (!IN_DEV_FORWARD(in_dev)) 1989 err = -EHOSTUNREACH; 1990 goto no_route; 1991 } 1992 1993 if (res->type == RTN_BROADCAST) { 1994 if (IN_DEV_BFORWARD(in_dev)) 1995 goto make_route; 1996 goto brd_input; 1997 } 1998 1999 if (res->type == RTN_LOCAL) { 2000 err = fib_validate_source(skb, saddr, daddr, tos, 2001 0, dev, in_dev, &itag); 2002 if (err < 0) 2003 goto martian_source; 2004 goto local_input; 2005 } 2006 2007 if (!IN_DEV_FORWARD(in_dev)) { 2008 err = -EHOSTUNREACH; 2009 goto no_route; 2010 } 2011 if (res->type != RTN_UNICAST) 2012 goto martian_destination; 2013 2014 make_route: 2015 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2016 out: return err; 2017 2018 brd_input: 2019 if (skb->protocol != htons(ETH_P_IP)) 2020 goto e_inval; 2021 2022 if (!ipv4_is_zeronet(saddr)) { 2023 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2024 in_dev, &itag); 2025 if (err < 0) 2026 goto martian_source; 2027 } 2028 flags |= RTCF_BROADCAST; 2029 res->type = RTN_BROADCAST; 2030 RT_CACHE_STAT_INC(in_brd); 2031 2032 local_input: 2033 do_cache = false; 2034 if (res->fi) { 2035 if (!itag) { 2036 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); 2037 if (rt_cache_valid(rth)) { 2038 skb_dst_set_noref(skb, &rth->dst); 2039 err = 0; 2040 goto out; 2041 } 2042 do_cache = true; 2043 } 2044 } 2045 2046 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2047 flags | RTCF_LOCAL, res->type, 2048 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2049 if (!rth) 2050 goto e_nobufs; 2051 2052 rth->dst.output= ip_rt_bug; 2053 #ifdef CONFIG_IP_ROUTE_CLASSID 2054 rth->dst.tclassid = itag; 2055 #endif 2056 rth->rt_is_input = 1; 2057 2058 RT_CACHE_STAT_INC(in_slow_tot); 2059 if (res->type == RTN_UNREACHABLE) { 2060 rth->dst.input= ip_error; 2061 rth->dst.error= -err; 2062 rth->rt_flags &= ~RTCF_LOCAL; 2063 } 2064 2065 if (do_cache) { 2066 struct fib_nh *nh = &FIB_RES_NH(*res); 2067 2068 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate); 2069 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2070 WARN_ON(rth->dst.input == lwtunnel_input); 2071 rth->dst.lwtstate->orig_input = rth->dst.input; 2072 rth->dst.input = lwtunnel_input; 2073 } 2074 2075 if (unlikely(!rt_cache_route(nh, rth))) 2076 rt_add_uncached_list(rth); 2077 } 2078 skb_dst_set(skb, &rth->dst); 2079 err = 0; 2080 goto out; 2081 2082 no_route: 2083 RT_CACHE_STAT_INC(in_no_route); 2084 res->type = RTN_UNREACHABLE; 2085 res->fi = NULL; 2086 res->table = NULL; 2087 goto local_input; 2088 2089 /* 2090 * Do not cache martian addresses: they should be logged (RFC1812) 2091 */ 2092 martian_destination: 2093 RT_CACHE_STAT_INC(in_martian_dst); 2094 #ifdef CONFIG_IP_ROUTE_VERBOSE 2095 if (IN_DEV_LOG_MARTIANS(in_dev)) 2096 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2097 &daddr, &saddr, dev->name); 2098 #endif 2099 2100 e_inval: 2101 err = -EINVAL; 2102 goto out; 2103 2104 e_nobufs: 2105 err = -ENOBUFS; 2106 goto out; 2107 2108 martian_source: 2109 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2110 goto out; 2111 } 2112 2113 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2114 u8 tos, struct net_device *dev) 2115 { 2116 struct fib_result res; 2117 int err; 2118 2119 tos &= IPTOS_RT_MASK; 2120 rcu_read_lock(); 2121 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2122 rcu_read_unlock(); 2123 2124 return err; 2125 } 2126 EXPORT_SYMBOL(ip_route_input_noref); 2127 2128 /* called with rcu_read_lock held */ 2129 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2130 u8 tos, struct net_device *dev, struct fib_result *res) 2131 { 2132 /* Multicast recognition logic is moved from route cache to here. 2133 The problem was that too many Ethernet cards have broken/missing 2134 hardware multicast filters :-( As result the host on multicasting 2135 network acquires a lot of useless route cache entries, sort of 2136 SDR messages from all the world. Now we try to get rid of them. 2137 Really, provided software IP multicast filter is organized 2138 reasonably (at least, hashed), it does not result in a slowdown 2139 comparing with route cache reject entries. 2140 Note, that multicast routers are not affected, because 2141 route cache entry is created eventually. 2142 */ 2143 if (ipv4_is_multicast(daddr)) { 2144 struct in_device *in_dev = __in_dev_get_rcu(dev); 2145 int our = 0; 2146 int err = -EINVAL; 2147 2148 if (in_dev) 2149 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2150 ip_hdr(skb)->protocol); 2151 2152 /* check l3 master if no match yet */ 2153 if ((!in_dev || !our) && netif_is_l3_slave(dev)) { 2154 struct in_device *l3_in_dev; 2155 2156 l3_in_dev = __in_dev_get_rcu(skb->dev); 2157 if (l3_in_dev) 2158 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2159 ip_hdr(skb)->protocol); 2160 } 2161 2162 if (our 2163 #ifdef CONFIG_IP_MROUTE 2164 || 2165 (!ipv4_is_local_multicast(daddr) && 2166 IN_DEV_MFORWARD(in_dev)) 2167 #endif 2168 ) { 2169 err = ip_route_input_mc(skb, daddr, saddr, 2170 tos, dev, our); 2171 } 2172 return err; 2173 } 2174 2175 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2176 } 2177 2178 /* called with rcu_read_lock() */ 2179 static struct rtable *__mkroute_output(const struct fib_result *res, 2180 const struct flowi4 *fl4, int orig_oif, 2181 struct net_device *dev_out, 2182 unsigned int flags) 2183 { 2184 struct fib_info *fi = res->fi; 2185 struct fib_nh_exception *fnhe; 2186 struct in_device *in_dev; 2187 u16 type = res->type; 2188 struct rtable *rth; 2189 bool do_cache; 2190 2191 in_dev = __in_dev_get_rcu(dev_out); 2192 if (!in_dev) 2193 return ERR_PTR(-EINVAL); 2194 2195 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2196 if (ipv4_is_loopback(fl4->saddr) && 2197 !(dev_out->flags & IFF_LOOPBACK) && 2198 !netif_is_l3_master(dev_out)) 2199 return ERR_PTR(-EINVAL); 2200 2201 if (ipv4_is_lbcast(fl4->daddr)) 2202 type = RTN_BROADCAST; 2203 else if (ipv4_is_multicast(fl4->daddr)) 2204 type = RTN_MULTICAST; 2205 else if (ipv4_is_zeronet(fl4->daddr)) 2206 return ERR_PTR(-EINVAL); 2207 2208 if (dev_out->flags & IFF_LOOPBACK) 2209 flags |= RTCF_LOCAL; 2210 2211 do_cache = true; 2212 if (type == RTN_BROADCAST) { 2213 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2214 fi = NULL; 2215 } else if (type == RTN_MULTICAST) { 2216 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2217 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2218 fl4->flowi4_proto)) 2219 flags &= ~RTCF_LOCAL; 2220 else 2221 do_cache = false; 2222 /* If multicast route do not exist use 2223 * default one, but do not gateway in this case. 2224 * Yes, it is hack. 2225 */ 2226 if (fi && res->prefixlen < 4) 2227 fi = NULL; 2228 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2229 (orig_oif != dev_out->ifindex)) { 2230 /* For local routes that require a particular output interface 2231 * we do not want to cache the result. Caching the result 2232 * causes incorrect behaviour when there are multiple source 2233 * addresses on the interface, the end result being that if the 2234 * intended recipient is waiting on that interface for the 2235 * packet he won't receive it because it will be delivered on 2236 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2237 * be set to the loopback interface as well. 2238 */ 2239 do_cache = false; 2240 } 2241 2242 fnhe = NULL; 2243 do_cache &= fi != NULL; 2244 if (fi) { 2245 struct rtable __rcu **prth; 2246 struct fib_nh *nh = &FIB_RES_NH(*res); 2247 2248 fnhe = find_exception(nh, fl4->daddr); 2249 if (!do_cache) 2250 goto add; 2251 if (fnhe) { 2252 prth = &fnhe->fnhe_rth_output; 2253 } else { 2254 if (unlikely(fl4->flowi4_flags & 2255 FLOWI_FLAG_KNOWN_NH && 2256 !(nh->nh_gw && 2257 nh->nh_scope == RT_SCOPE_LINK))) { 2258 do_cache = false; 2259 goto add; 2260 } 2261 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 2262 } 2263 rth = rcu_dereference(*prth); 2264 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2265 return rth; 2266 } 2267 2268 add: 2269 rth = rt_dst_alloc(dev_out, flags, type, 2270 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2271 IN_DEV_CONF_GET(in_dev, NOXFRM), 2272 do_cache); 2273 if (!rth) 2274 return ERR_PTR(-ENOBUFS); 2275 2276 rth->rt_iif = orig_oif; 2277 2278 RT_CACHE_STAT_INC(out_slow_tot); 2279 2280 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2281 if (flags & RTCF_LOCAL && 2282 !(dev_out->flags & IFF_LOOPBACK)) { 2283 rth->dst.output = ip_mc_output; 2284 RT_CACHE_STAT_INC(out_slow_mc); 2285 } 2286 #ifdef CONFIG_IP_MROUTE 2287 if (type == RTN_MULTICAST) { 2288 if (IN_DEV_MFORWARD(in_dev) && 2289 !ipv4_is_local_multicast(fl4->daddr)) { 2290 rth->dst.input = ip_mr_input; 2291 rth->dst.output = ip_mc_output; 2292 } 2293 } 2294 #endif 2295 } 2296 2297 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2298 lwtunnel_set_redirect(&rth->dst); 2299 2300 return rth; 2301 } 2302 2303 /* 2304 * Major route resolver routine. 2305 */ 2306 2307 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2308 const struct sk_buff *skb) 2309 { 2310 __u8 tos = RT_FL_TOS(fl4); 2311 struct fib_result res = { 2312 .type = RTN_UNSPEC, 2313 .fi = NULL, 2314 .table = NULL, 2315 .tclassid = 0, 2316 }; 2317 struct rtable *rth; 2318 2319 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2320 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2321 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2322 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2323 2324 rcu_read_lock(); 2325 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2326 rcu_read_unlock(); 2327 2328 return rth; 2329 } 2330 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2331 2332 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2333 struct fib_result *res, 2334 const struct sk_buff *skb) 2335 { 2336 struct net_device *dev_out = NULL; 2337 int orig_oif = fl4->flowi4_oif; 2338 unsigned int flags = 0; 2339 struct rtable *rth; 2340 int err = -ENETUNREACH; 2341 2342 if (fl4->saddr) { 2343 rth = ERR_PTR(-EINVAL); 2344 if (ipv4_is_multicast(fl4->saddr) || 2345 ipv4_is_lbcast(fl4->saddr) || 2346 ipv4_is_zeronet(fl4->saddr)) 2347 goto out; 2348 2349 /* I removed check for oif == dev_out->oif here. 2350 It was wrong for two reasons: 2351 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2352 is assigned to multiple interfaces. 2353 2. Moreover, we are allowed to send packets with saddr 2354 of another iface. --ANK 2355 */ 2356 2357 if (fl4->flowi4_oif == 0 && 2358 (ipv4_is_multicast(fl4->daddr) || 2359 ipv4_is_lbcast(fl4->daddr))) { 2360 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2361 dev_out = __ip_dev_find(net, fl4->saddr, false); 2362 if (!dev_out) 2363 goto out; 2364 2365 /* Special hack: user can direct multicasts 2366 and limited broadcast via necessary interface 2367 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2368 This hack is not just for fun, it allows 2369 vic,vat and friends to work. 2370 They bind socket to loopback, set ttl to zero 2371 and expect that it will work. 2372 From the viewpoint of routing cache they are broken, 2373 because we are not allowed to build multicast path 2374 with loopback source addr (look, routing cache 2375 cannot know, that ttl is zero, so that packet 2376 will not leave this host and route is valid). 2377 Luckily, this hack is good workaround. 2378 */ 2379 2380 fl4->flowi4_oif = dev_out->ifindex; 2381 goto make_route; 2382 } 2383 2384 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2385 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2386 if (!__ip_dev_find(net, fl4->saddr, false)) 2387 goto out; 2388 } 2389 } 2390 2391 2392 if (fl4->flowi4_oif) { 2393 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2394 rth = ERR_PTR(-ENODEV); 2395 if (!dev_out) 2396 goto out; 2397 2398 /* RACE: Check return value of inet_select_addr instead. */ 2399 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2400 rth = ERR_PTR(-ENETUNREACH); 2401 goto out; 2402 } 2403 if (ipv4_is_local_multicast(fl4->daddr) || 2404 ipv4_is_lbcast(fl4->daddr) || 2405 fl4->flowi4_proto == IPPROTO_IGMP) { 2406 if (!fl4->saddr) 2407 fl4->saddr = inet_select_addr(dev_out, 0, 2408 RT_SCOPE_LINK); 2409 goto make_route; 2410 } 2411 if (!fl4->saddr) { 2412 if (ipv4_is_multicast(fl4->daddr)) 2413 fl4->saddr = inet_select_addr(dev_out, 0, 2414 fl4->flowi4_scope); 2415 else if (!fl4->daddr) 2416 fl4->saddr = inet_select_addr(dev_out, 0, 2417 RT_SCOPE_HOST); 2418 } 2419 } 2420 2421 if (!fl4->daddr) { 2422 fl4->daddr = fl4->saddr; 2423 if (!fl4->daddr) 2424 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2425 dev_out = net->loopback_dev; 2426 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2427 res->type = RTN_LOCAL; 2428 flags |= RTCF_LOCAL; 2429 goto make_route; 2430 } 2431 2432 err = fib_lookup(net, fl4, res, 0); 2433 if (err) { 2434 res->fi = NULL; 2435 res->table = NULL; 2436 if (fl4->flowi4_oif && 2437 (ipv4_is_multicast(fl4->daddr) || 2438 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2439 /* Apparently, routing tables are wrong. Assume, 2440 that the destination is on link. 2441 2442 WHY? DW. 2443 Because we are allowed to send to iface 2444 even if it has NO routes and NO assigned 2445 addresses. When oif is specified, routing 2446 tables are looked up with only one purpose: 2447 to catch if destination is gatewayed, rather than 2448 direct. Moreover, if MSG_DONTROUTE is set, 2449 we send packet, ignoring both routing tables 2450 and ifaddr state. --ANK 2451 2452 2453 We could make it even if oif is unknown, 2454 likely IPv6, but we do not. 2455 */ 2456 2457 if (fl4->saddr == 0) 2458 fl4->saddr = inet_select_addr(dev_out, 0, 2459 RT_SCOPE_LINK); 2460 res->type = RTN_UNICAST; 2461 goto make_route; 2462 } 2463 rth = ERR_PTR(err); 2464 goto out; 2465 } 2466 2467 if (res->type == RTN_LOCAL) { 2468 if (!fl4->saddr) { 2469 if (res->fi->fib_prefsrc) 2470 fl4->saddr = res->fi->fib_prefsrc; 2471 else 2472 fl4->saddr = fl4->daddr; 2473 } 2474 2475 /* L3 master device is the loopback for that domain */ 2476 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2477 net->loopback_dev; 2478 2479 /* make sure orig_oif points to fib result device even 2480 * though packet rx/tx happens over loopback or l3mdev 2481 */ 2482 orig_oif = FIB_RES_OIF(*res); 2483 2484 fl4->flowi4_oif = dev_out->ifindex; 2485 flags |= RTCF_LOCAL; 2486 goto make_route; 2487 } 2488 2489 fib_select_path(net, res, fl4, skb); 2490 2491 dev_out = FIB_RES_DEV(*res); 2492 fl4->flowi4_oif = dev_out->ifindex; 2493 2494 2495 make_route: 2496 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2497 2498 out: 2499 return rth; 2500 } 2501 2502 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2503 { 2504 return NULL; 2505 } 2506 2507 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2508 { 2509 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2510 2511 return mtu ? : dst->dev->mtu; 2512 } 2513 2514 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2515 struct sk_buff *skb, u32 mtu) 2516 { 2517 } 2518 2519 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2520 struct sk_buff *skb) 2521 { 2522 } 2523 2524 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2525 unsigned long old) 2526 { 2527 return NULL; 2528 } 2529 2530 static struct dst_ops ipv4_dst_blackhole_ops = { 2531 .family = AF_INET, 2532 .check = ipv4_blackhole_dst_check, 2533 .mtu = ipv4_blackhole_mtu, 2534 .default_advmss = ipv4_default_advmss, 2535 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2536 .redirect = ipv4_rt_blackhole_redirect, 2537 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2538 .neigh_lookup = ipv4_neigh_lookup, 2539 }; 2540 2541 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2542 { 2543 struct rtable *ort = (struct rtable *) dst_orig; 2544 struct rtable *rt; 2545 2546 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2547 if (rt) { 2548 struct dst_entry *new = &rt->dst; 2549 2550 new->__use = 1; 2551 new->input = dst_discard; 2552 new->output = dst_discard_out; 2553 2554 new->dev = net->loopback_dev; 2555 if (new->dev) 2556 dev_hold(new->dev); 2557 2558 rt->rt_is_input = ort->rt_is_input; 2559 rt->rt_iif = ort->rt_iif; 2560 rt->rt_pmtu = ort->rt_pmtu; 2561 rt->rt_mtu_locked = ort->rt_mtu_locked; 2562 2563 rt->rt_genid = rt_genid_ipv4(net); 2564 rt->rt_flags = ort->rt_flags; 2565 rt->rt_type = ort->rt_type; 2566 rt->rt_gateway = ort->rt_gateway; 2567 rt->rt_uses_gateway = ort->rt_uses_gateway; 2568 2569 INIT_LIST_HEAD(&rt->rt_uncached); 2570 } 2571 2572 dst_release(dst_orig); 2573 2574 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2575 } 2576 2577 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2578 const struct sock *sk) 2579 { 2580 struct rtable *rt = __ip_route_output_key(net, flp4); 2581 2582 if (IS_ERR(rt)) 2583 return rt; 2584 2585 if (flp4->flowi4_proto) 2586 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2587 flowi4_to_flowi(flp4), 2588 sk, 0); 2589 2590 return rt; 2591 } 2592 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2593 2594 /* called with rcu_read_lock held */ 2595 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2596 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2597 struct sk_buff *skb, u32 portid, u32 seq) 2598 { 2599 struct rtmsg *r; 2600 struct nlmsghdr *nlh; 2601 unsigned long expires = 0; 2602 u32 error; 2603 u32 metrics[RTAX_MAX]; 2604 2605 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2606 if (!nlh) 2607 return -EMSGSIZE; 2608 2609 r = nlmsg_data(nlh); 2610 r->rtm_family = AF_INET; 2611 r->rtm_dst_len = 32; 2612 r->rtm_src_len = 0; 2613 r->rtm_tos = fl4->flowi4_tos; 2614 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2615 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2616 goto nla_put_failure; 2617 r->rtm_type = rt->rt_type; 2618 r->rtm_scope = RT_SCOPE_UNIVERSE; 2619 r->rtm_protocol = RTPROT_UNSPEC; 2620 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2621 if (rt->rt_flags & RTCF_NOTIFY) 2622 r->rtm_flags |= RTM_F_NOTIFY; 2623 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2624 r->rtm_flags |= RTCF_DOREDIRECT; 2625 2626 if (nla_put_in_addr(skb, RTA_DST, dst)) 2627 goto nla_put_failure; 2628 if (src) { 2629 r->rtm_src_len = 32; 2630 if (nla_put_in_addr(skb, RTA_SRC, src)) 2631 goto nla_put_failure; 2632 } 2633 if (rt->dst.dev && 2634 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2635 goto nla_put_failure; 2636 #ifdef CONFIG_IP_ROUTE_CLASSID 2637 if (rt->dst.tclassid && 2638 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2639 goto nla_put_failure; 2640 #endif 2641 if (!rt_is_input_route(rt) && 2642 fl4->saddr != src) { 2643 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2644 goto nla_put_failure; 2645 } 2646 if (rt->rt_uses_gateway && 2647 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway)) 2648 goto nla_put_failure; 2649 2650 expires = rt->dst.expires; 2651 if (expires) { 2652 unsigned long now = jiffies; 2653 2654 if (time_before(now, expires)) 2655 expires -= now; 2656 else 2657 expires = 0; 2658 } 2659 2660 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2661 if (rt->rt_pmtu && expires) 2662 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2663 if (rt->rt_mtu_locked && expires) 2664 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2665 if (rtnetlink_put_metrics(skb, metrics) < 0) 2666 goto nla_put_failure; 2667 2668 if (fl4->flowi4_mark && 2669 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2670 goto nla_put_failure; 2671 2672 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2673 nla_put_u32(skb, RTA_UID, 2674 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2675 goto nla_put_failure; 2676 2677 error = rt->dst.error; 2678 2679 if (rt_is_input_route(rt)) { 2680 #ifdef CONFIG_IP_MROUTE 2681 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2682 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2683 int err = ipmr_get_route(net, skb, 2684 fl4->saddr, fl4->daddr, 2685 r, portid); 2686 2687 if (err <= 0) { 2688 if (err == 0) 2689 return 0; 2690 goto nla_put_failure; 2691 } 2692 } else 2693 #endif 2694 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2695 goto nla_put_failure; 2696 } 2697 2698 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2699 goto nla_put_failure; 2700 2701 nlmsg_end(skb, nlh); 2702 return 0; 2703 2704 nla_put_failure: 2705 nlmsg_cancel(skb, nlh); 2706 return -EMSGSIZE; 2707 } 2708 2709 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2710 u8 ip_proto, __be16 sport, 2711 __be16 dport) 2712 { 2713 struct sk_buff *skb; 2714 struct iphdr *iph; 2715 2716 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2717 if (!skb) 2718 return NULL; 2719 2720 /* Reserve room for dummy headers, this skb can pass 2721 * through good chunk of routing engine. 2722 */ 2723 skb_reset_mac_header(skb); 2724 skb_reset_network_header(skb); 2725 skb->protocol = htons(ETH_P_IP); 2726 iph = skb_put(skb, sizeof(struct iphdr)); 2727 iph->protocol = ip_proto; 2728 iph->saddr = src; 2729 iph->daddr = dst; 2730 iph->version = 0x4; 2731 iph->frag_off = 0; 2732 iph->ihl = 0x5; 2733 skb_set_transport_header(skb, skb->len); 2734 2735 switch (iph->protocol) { 2736 case IPPROTO_UDP: { 2737 struct udphdr *udph; 2738 2739 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2740 udph->source = sport; 2741 udph->dest = dport; 2742 udph->len = sizeof(struct udphdr); 2743 udph->check = 0; 2744 break; 2745 } 2746 case IPPROTO_TCP: { 2747 struct tcphdr *tcph; 2748 2749 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2750 tcph->source = sport; 2751 tcph->dest = dport; 2752 tcph->doff = sizeof(struct tcphdr) / 4; 2753 tcph->rst = 1; 2754 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2755 src, dst, 0); 2756 break; 2757 } 2758 case IPPROTO_ICMP: { 2759 struct icmphdr *icmph; 2760 2761 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2762 icmph->type = ICMP_ECHO; 2763 icmph->code = 0; 2764 } 2765 } 2766 2767 return skb; 2768 } 2769 2770 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 2771 const struct nlmsghdr *nlh, 2772 struct nlattr **tb, 2773 struct netlink_ext_ack *extack) 2774 { 2775 struct rtmsg *rtm; 2776 int i, err; 2777 2778 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 2779 NL_SET_ERR_MSG(extack, 2780 "ipv4: Invalid header for route get request"); 2781 return -EINVAL; 2782 } 2783 2784 if (!netlink_strict_get_check(skb)) 2785 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, 2786 rtm_ipv4_policy, extack); 2787 2788 rtm = nlmsg_data(nlh); 2789 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 2790 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 2791 rtm->rtm_table || rtm->rtm_protocol || 2792 rtm->rtm_scope || rtm->rtm_type) { 2793 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 2794 return -EINVAL; 2795 } 2796 2797 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 2798 RTM_F_LOOKUP_TABLE | 2799 RTM_F_FIB_MATCH)) { 2800 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 2801 return -EINVAL; 2802 } 2803 2804 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 2805 rtm_ipv4_policy, extack); 2806 if (err) 2807 return err; 2808 2809 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 2810 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 2811 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 2812 return -EINVAL; 2813 } 2814 2815 for (i = 0; i <= RTA_MAX; i++) { 2816 if (!tb[i]) 2817 continue; 2818 2819 switch (i) { 2820 case RTA_IIF: 2821 case RTA_OIF: 2822 case RTA_SRC: 2823 case RTA_DST: 2824 case RTA_IP_PROTO: 2825 case RTA_SPORT: 2826 case RTA_DPORT: 2827 case RTA_MARK: 2828 case RTA_UID: 2829 break; 2830 default: 2831 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 2832 return -EINVAL; 2833 } 2834 } 2835 2836 return 0; 2837 } 2838 2839 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2840 struct netlink_ext_ack *extack) 2841 { 2842 struct net *net = sock_net(in_skb->sk); 2843 struct nlattr *tb[RTA_MAX+1]; 2844 u32 table_id = RT_TABLE_MAIN; 2845 __be16 sport = 0, dport = 0; 2846 struct fib_result res = {}; 2847 u8 ip_proto = IPPROTO_UDP; 2848 struct rtable *rt = NULL; 2849 struct sk_buff *skb; 2850 struct rtmsg *rtm; 2851 struct flowi4 fl4 = {}; 2852 __be32 dst = 0; 2853 __be32 src = 0; 2854 kuid_t uid; 2855 u32 iif; 2856 int err; 2857 int mark; 2858 2859 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 2860 if (err < 0) 2861 return err; 2862 2863 rtm = nlmsg_data(nlh); 2864 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2865 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2866 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2867 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2868 if (tb[RTA_UID]) 2869 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2870 else 2871 uid = (iif ? INVALID_UID : current_uid()); 2872 2873 if (tb[RTA_IP_PROTO]) { 2874 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2875 &ip_proto, extack); 2876 if (err) 2877 return err; 2878 } 2879 2880 if (tb[RTA_SPORT]) 2881 sport = nla_get_be16(tb[RTA_SPORT]); 2882 2883 if (tb[RTA_DPORT]) 2884 dport = nla_get_be16(tb[RTA_DPORT]); 2885 2886 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2887 if (!skb) 2888 return -ENOBUFS; 2889 2890 fl4.daddr = dst; 2891 fl4.saddr = src; 2892 fl4.flowi4_tos = rtm->rtm_tos; 2893 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2894 fl4.flowi4_mark = mark; 2895 fl4.flowi4_uid = uid; 2896 if (sport) 2897 fl4.fl4_sport = sport; 2898 if (dport) 2899 fl4.fl4_dport = dport; 2900 fl4.flowi4_proto = ip_proto; 2901 2902 rcu_read_lock(); 2903 2904 if (iif) { 2905 struct net_device *dev; 2906 2907 dev = dev_get_by_index_rcu(net, iif); 2908 if (!dev) { 2909 err = -ENODEV; 2910 goto errout_rcu; 2911 } 2912 2913 fl4.flowi4_iif = iif; /* for rt_fill_info */ 2914 skb->dev = dev; 2915 skb->mark = mark; 2916 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 2917 dev, &res); 2918 2919 rt = skb_rtable(skb); 2920 if (err == 0 && rt->dst.error) 2921 err = -rt->dst.error; 2922 } else { 2923 fl4.flowi4_iif = LOOPBACK_IFINDEX; 2924 skb->dev = net->loopback_dev; 2925 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 2926 err = 0; 2927 if (IS_ERR(rt)) 2928 err = PTR_ERR(rt); 2929 else 2930 skb_dst_set(skb, &rt->dst); 2931 } 2932 2933 if (err) 2934 goto errout_rcu; 2935 2936 if (rtm->rtm_flags & RTM_F_NOTIFY) 2937 rt->rt_flags |= RTCF_NOTIFY; 2938 2939 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 2940 table_id = res.table ? res.table->tb_id : 0; 2941 2942 /* reset skb for netlink reply msg */ 2943 skb_trim(skb, 0); 2944 skb_reset_network_header(skb); 2945 skb_reset_transport_header(skb); 2946 skb_reset_mac_header(skb); 2947 2948 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 2949 if (!res.fi) { 2950 err = fib_props[res.type].error; 2951 if (!err) 2952 err = -EHOSTUNREACH; 2953 goto errout_rcu; 2954 } 2955 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 2956 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 2957 rt->rt_type, res.prefix, res.prefixlen, 2958 fl4.flowi4_tos, res.fi, 0); 2959 } else { 2960 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 2961 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 2962 } 2963 if (err < 0) 2964 goto errout_rcu; 2965 2966 rcu_read_unlock(); 2967 2968 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 2969 2970 errout_free: 2971 return err; 2972 errout_rcu: 2973 rcu_read_unlock(); 2974 kfree_skb(skb); 2975 goto errout_free; 2976 } 2977 2978 void ip_rt_multicast_event(struct in_device *in_dev) 2979 { 2980 rt_cache_flush(dev_net(in_dev->dev)); 2981 } 2982 2983 #ifdef CONFIG_SYSCTL 2984 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 2985 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 2986 static int ip_rt_gc_elasticity __read_mostly = 8; 2987 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 2988 2989 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 2990 void __user *buffer, 2991 size_t *lenp, loff_t *ppos) 2992 { 2993 struct net *net = (struct net *)__ctl->extra1; 2994 2995 if (write) { 2996 rt_cache_flush(net); 2997 fnhe_genid_bump(net); 2998 return 0; 2999 } 3000 3001 return -EINVAL; 3002 } 3003 3004 static struct ctl_table ipv4_route_table[] = { 3005 { 3006 .procname = "gc_thresh", 3007 .data = &ipv4_dst_ops.gc_thresh, 3008 .maxlen = sizeof(int), 3009 .mode = 0644, 3010 .proc_handler = proc_dointvec, 3011 }, 3012 { 3013 .procname = "max_size", 3014 .data = &ip_rt_max_size, 3015 .maxlen = sizeof(int), 3016 .mode = 0644, 3017 .proc_handler = proc_dointvec, 3018 }, 3019 { 3020 /* Deprecated. Use gc_min_interval_ms */ 3021 3022 .procname = "gc_min_interval", 3023 .data = &ip_rt_gc_min_interval, 3024 .maxlen = sizeof(int), 3025 .mode = 0644, 3026 .proc_handler = proc_dointvec_jiffies, 3027 }, 3028 { 3029 .procname = "gc_min_interval_ms", 3030 .data = &ip_rt_gc_min_interval, 3031 .maxlen = sizeof(int), 3032 .mode = 0644, 3033 .proc_handler = proc_dointvec_ms_jiffies, 3034 }, 3035 { 3036 .procname = "gc_timeout", 3037 .data = &ip_rt_gc_timeout, 3038 .maxlen = sizeof(int), 3039 .mode = 0644, 3040 .proc_handler = proc_dointvec_jiffies, 3041 }, 3042 { 3043 .procname = "gc_interval", 3044 .data = &ip_rt_gc_interval, 3045 .maxlen = sizeof(int), 3046 .mode = 0644, 3047 .proc_handler = proc_dointvec_jiffies, 3048 }, 3049 { 3050 .procname = "redirect_load", 3051 .data = &ip_rt_redirect_load, 3052 .maxlen = sizeof(int), 3053 .mode = 0644, 3054 .proc_handler = proc_dointvec, 3055 }, 3056 { 3057 .procname = "redirect_number", 3058 .data = &ip_rt_redirect_number, 3059 .maxlen = sizeof(int), 3060 .mode = 0644, 3061 .proc_handler = proc_dointvec, 3062 }, 3063 { 3064 .procname = "redirect_silence", 3065 .data = &ip_rt_redirect_silence, 3066 .maxlen = sizeof(int), 3067 .mode = 0644, 3068 .proc_handler = proc_dointvec, 3069 }, 3070 { 3071 .procname = "error_cost", 3072 .data = &ip_rt_error_cost, 3073 .maxlen = sizeof(int), 3074 .mode = 0644, 3075 .proc_handler = proc_dointvec, 3076 }, 3077 { 3078 .procname = "error_burst", 3079 .data = &ip_rt_error_burst, 3080 .maxlen = sizeof(int), 3081 .mode = 0644, 3082 .proc_handler = proc_dointvec, 3083 }, 3084 { 3085 .procname = "gc_elasticity", 3086 .data = &ip_rt_gc_elasticity, 3087 .maxlen = sizeof(int), 3088 .mode = 0644, 3089 .proc_handler = proc_dointvec, 3090 }, 3091 { 3092 .procname = "mtu_expires", 3093 .data = &ip_rt_mtu_expires, 3094 .maxlen = sizeof(int), 3095 .mode = 0644, 3096 .proc_handler = proc_dointvec_jiffies, 3097 }, 3098 { 3099 .procname = "min_pmtu", 3100 .data = &ip_rt_min_pmtu, 3101 .maxlen = sizeof(int), 3102 .mode = 0644, 3103 .proc_handler = proc_dointvec_minmax, 3104 .extra1 = &ip_min_valid_pmtu, 3105 }, 3106 { 3107 .procname = "min_adv_mss", 3108 .data = &ip_rt_min_advmss, 3109 .maxlen = sizeof(int), 3110 .mode = 0644, 3111 .proc_handler = proc_dointvec, 3112 }, 3113 { } 3114 }; 3115 3116 static struct ctl_table ipv4_route_flush_table[] = { 3117 { 3118 .procname = "flush", 3119 .maxlen = sizeof(int), 3120 .mode = 0200, 3121 .proc_handler = ipv4_sysctl_rtcache_flush, 3122 }, 3123 { }, 3124 }; 3125 3126 static __net_init int sysctl_route_net_init(struct net *net) 3127 { 3128 struct ctl_table *tbl; 3129 3130 tbl = ipv4_route_flush_table; 3131 if (!net_eq(net, &init_net)) { 3132 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3133 if (!tbl) 3134 goto err_dup; 3135 3136 /* Don't export sysctls to unprivileged users */ 3137 if (net->user_ns != &init_user_ns) 3138 tbl[0].procname = NULL; 3139 } 3140 tbl[0].extra1 = net; 3141 3142 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3143 if (!net->ipv4.route_hdr) 3144 goto err_reg; 3145 return 0; 3146 3147 err_reg: 3148 if (tbl != ipv4_route_flush_table) 3149 kfree(tbl); 3150 err_dup: 3151 return -ENOMEM; 3152 } 3153 3154 static __net_exit void sysctl_route_net_exit(struct net *net) 3155 { 3156 struct ctl_table *tbl; 3157 3158 tbl = net->ipv4.route_hdr->ctl_table_arg; 3159 unregister_net_sysctl_table(net->ipv4.route_hdr); 3160 BUG_ON(tbl == ipv4_route_flush_table); 3161 kfree(tbl); 3162 } 3163 3164 static __net_initdata struct pernet_operations sysctl_route_ops = { 3165 .init = sysctl_route_net_init, 3166 .exit = sysctl_route_net_exit, 3167 }; 3168 #endif 3169 3170 static __net_init int rt_genid_init(struct net *net) 3171 { 3172 atomic_set(&net->ipv4.rt_genid, 0); 3173 atomic_set(&net->fnhe_genid, 0); 3174 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3175 return 0; 3176 } 3177 3178 static __net_initdata struct pernet_operations rt_genid_ops = { 3179 .init = rt_genid_init, 3180 }; 3181 3182 static int __net_init ipv4_inetpeer_init(struct net *net) 3183 { 3184 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3185 3186 if (!bp) 3187 return -ENOMEM; 3188 inet_peer_base_init(bp); 3189 net->ipv4.peers = bp; 3190 return 0; 3191 } 3192 3193 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3194 { 3195 struct inet_peer_base *bp = net->ipv4.peers; 3196 3197 net->ipv4.peers = NULL; 3198 inetpeer_invalidate_tree(bp); 3199 kfree(bp); 3200 } 3201 3202 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3203 .init = ipv4_inetpeer_init, 3204 .exit = ipv4_inetpeer_exit, 3205 }; 3206 3207 #ifdef CONFIG_IP_ROUTE_CLASSID 3208 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3209 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3210 3211 int __init ip_rt_init(void) 3212 { 3213 int cpu; 3214 3215 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3216 GFP_KERNEL); 3217 if (!ip_idents) 3218 panic("IP: failed to allocate ip_idents\n"); 3219 3220 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3221 3222 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3223 if (!ip_tstamps) 3224 panic("IP: failed to allocate ip_tstamps\n"); 3225 3226 for_each_possible_cpu(cpu) { 3227 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3228 3229 INIT_LIST_HEAD(&ul->head); 3230 spin_lock_init(&ul->lock); 3231 } 3232 #ifdef CONFIG_IP_ROUTE_CLASSID 3233 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3234 if (!ip_rt_acct) 3235 panic("IP: failed to allocate ip_rt_acct\n"); 3236 #endif 3237 3238 ipv4_dst_ops.kmem_cachep = 3239 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3240 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3241 3242 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3243 3244 if (dst_entries_init(&ipv4_dst_ops) < 0) 3245 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3246 3247 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3248 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3249 3250 ipv4_dst_ops.gc_thresh = ~0; 3251 ip_rt_max_size = INT_MAX; 3252 3253 devinet_init(); 3254 ip_fib_init(); 3255 3256 if (ip_rt_proc_init()) 3257 pr_err("Unable to create route proc files\n"); 3258 #ifdef CONFIG_XFRM 3259 xfrm_init(); 3260 xfrm4_init(); 3261 #endif 3262 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3263 RTNL_FLAG_DOIT_UNLOCKED); 3264 3265 #ifdef CONFIG_SYSCTL 3266 register_pernet_subsys(&sysctl_route_ops); 3267 #endif 3268 register_pernet_subsys(&rt_genid_ops); 3269 register_pernet_subsys(&ipv4_inetpeer_ops); 3270 return 0; 3271 } 3272 3273 #ifdef CONFIG_SYSCTL 3274 /* 3275 * We really need to sanitize the damn ipv4 init order, then all 3276 * this nonsense will go away. 3277 */ 3278 void __init ip_static_sysctl_init(void) 3279 { 3280 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3281 } 3282 #endif 3283