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route.c
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linux-6.19.14/net/ipv4/route.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61#define pr_fmt(fmt) "IPv4: " fmt 62 63#include <linux/module.h> 64#include <linux/bitops.h> 65#include <linux/kernel.h> 66#include <linux/mm.h> 67#include <linux/memblock.h> 68#include <linux/socket.h> 69#include <linux/errno.h> 70#include <linux/in.h> 71#include <linux/inet.h> 72#include <linux/netdevice.h> 73#include <linux/proc_fs.h> 74#include <linux/init.h> 75#include <linux/skbuff.h> 76#include <linux/inetdevice.h> 77#include <linux/igmp.h> 78#include <linux/pkt_sched.h> 79#include <linux/mroute.h> 80#include <linux/netfilter_ipv4.h> 81#include <linux/random.h> 82#include <linux/rcupdate.h> 83#include <linux/slab.h> 84#include <linux/jhash.h> 85#include <net/dst.h> 86#include <net/dst_metadata.h> 87#include <net/flow.h> 88#include <net/inet_dscp.h> 89#include <net/net_namespace.h> 90#include <net/ip.h> 91#include <net/route.h> 92#include <net/inetpeer.h> 93#include <net/sock.h> 94#include <net/ip_fib.h> 95#include <net/nexthop.h> 96#include <net/tcp.h> 97#include <net/icmp.h> 98#include <net/xfrm.h> 99#include <net/lwtunnel.h> 100#include <net/netevent.h> 101#include <net/rtnetlink.h> 102#ifdef CONFIG_SYSCTL 103#include <linux/sysctl.h> 104#endif 105#include <net/secure_seq.h> 106#include <net/ip_tunnels.h> 107 108#include "fib_lookup.h" 109 110#define RT_GC_TIMEOUT (300*HZ) 111 112#define DEFAULT_MIN_PMTU (512 + 20 + 20) 113#define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 114#define DEFAULT_MIN_ADVMSS 256 115static int ip_rt_max_size; 116static int ip_rt_redirect_number __read_mostly = 9; 117static int ip_rt_redirect_load __read_mostly = HZ / 50; 118static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 119static int ip_rt_error_cost __read_mostly = HZ; 120static int ip_rt_error_burst __read_mostly = 5 * HZ; 121 122static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 123 124/* 125 * Interface to generic destination cache. 126 */ 127 128INDIRECT_CALLABLE_SCOPE 129struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 130static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 131INDIRECT_CALLABLE_SCOPE 132unsigned int ipv4_mtu(const struct dst_entry *dst); 133static void ipv4_negative_advice(struct sock *sk, 134 struct dst_entry *dst); 135static void ipv4_link_failure(struct sk_buff *skb); 136static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 137 struct sk_buff *skb, u32 mtu, 138 bool confirm_neigh); 139static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 140 struct sk_buff *skb); 141static void ipv4_dst_destroy(struct dst_entry *dst); 142 143static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 144{ 145 WARN_ON(1); 146 return NULL; 147} 148 149static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 150 struct sk_buff *skb, 151 const void *daddr); 152static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 153 154static struct dst_ops ipv4_dst_ops = { 155 .family = AF_INET, 156 .check = ipv4_dst_check, 157 .default_advmss = ipv4_default_advmss, 158 .mtu = ipv4_mtu, 159 .cow_metrics = ipv4_cow_metrics, 160 .destroy = ipv4_dst_destroy, 161 .negative_advice = ipv4_negative_advice, 162 .link_failure = ipv4_link_failure, 163 .update_pmtu = ip_rt_update_pmtu, 164 .redirect = ip_do_redirect, 165 .local_out = __ip_local_out, 166 .neigh_lookup = ipv4_neigh_lookup, 167 .confirm_neigh = ipv4_confirm_neigh, 168}; 169 170#define ECN_OR_COST(class) TC_PRIO_##class 171 172const __u8 ip_tos2prio[16] = { 173 TC_PRIO_BESTEFFORT, 174 ECN_OR_COST(BESTEFFORT), 175 TC_PRIO_BESTEFFORT, 176 ECN_OR_COST(BESTEFFORT), 177 TC_PRIO_BULK, 178 ECN_OR_COST(BULK), 179 TC_PRIO_BULK, 180 ECN_OR_COST(BULK), 181 TC_PRIO_INTERACTIVE, 182 ECN_OR_COST(INTERACTIVE), 183 TC_PRIO_INTERACTIVE, 184 ECN_OR_COST(INTERACTIVE), 185 TC_PRIO_INTERACTIVE_BULK, 186 ECN_OR_COST(INTERACTIVE_BULK), 187 TC_PRIO_INTERACTIVE_BULK, 188 ECN_OR_COST(INTERACTIVE_BULK) 189}; 190EXPORT_SYMBOL(ip_tos2prio); 191 192static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 193#ifndef CONFIG_PREEMPT_RT 194#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 195#else 196#define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) 197#endif 198 199#ifdef CONFIG_PROC_FS 200static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 201{ 202 if (*pos) 203 return NULL; 204 return SEQ_START_TOKEN; 205} 206 207static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 208{ 209 ++*pos; 210 return NULL; 211} 212 213static void rt_cache_seq_stop(struct seq_file *seq, void *v) 214{ 215} 216 217static int rt_cache_seq_show(struct seq_file *seq, void *v) 218{ 219 if (v == SEQ_START_TOKEN) 220 seq_printf(seq, "%-127s\n", 221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 223 "HHUptod\tSpecDst"); 224 return 0; 225} 226 227static const struct seq_operations rt_cache_seq_ops = { 228 .start = rt_cache_seq_start, 229 .next = rt_cache_seq_next, 230 .stop = rt_cache_seq_stop, 231 .show = rt_cache_seq_show, 232}; 233 234static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 235{ 236 int cpu; 237 238 if (*pos == 0) 239 return SEQ_START_TOKEN; 240 241 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 242 if (!cpu_possible(cpu)) 243 continue; 244 *pos = cpu+1; 245 return &per_cpu(rt_cache_stat, cpu); 246 } 247 return NULL; 248} 249 250static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 251{ 252 int cpu; 253 254 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 255 if (!cpu_possible(cpu)) 256 continue; 257 *pos = cpu+1; 258 return &per_cpu(rt_cache_stat, cpu); 259 } 260 (*pos)++; 261 return NULL; 262 263} 264 265static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 266{ 267 268} 269 270static int rt_cpu_seq_show(struct seq_file *seq, void *v) 271{ 272 struct rt_cache_stat *st = v; 273 274 if (v == SEQ_START_TOKEN) { 275 seq_puts(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"); 276 return 0; 277 } 278 279 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 280 "%08x %08x %08x %08x %08x %08x " 281 "%08x %08x %08x %08x\n", 282 dst_entries_get_slow(&ipv4_dst_ops), 283 0, /* st->in_hit */ 284 st->in_slow_tot, 285 st->in_slow_mc, 286 st->in_no_route, 287 st->in_brd, 288 st->in_martian_dst, 289 st->in_martian_src, 290 291 0, /* st->out_hit */ 292 st->out_slow_tot, 293 st->out_slow_mc, 294 295 0, /* st->gc_total */ 296 0, /* st->gc_ignored */ 297 0, /* st->gc_goal_miss */ 298 0, /* st->gc_dst_overflow */ 299 0, /* st->in_hlist_search */ 300 0 /* st->out_hlist_search */ 301 ); 302 return 0; 303} 304 305static const struct seq_operations rt_cpu_seq_ops = { 306 .start = rt_cpu_seq_start, 307 .next = rt_cpu_seq_next, 308 .stop = rt_cpu_seq_stop, 309 .show = rt_cpu_seq_show, 310}; 311 312#ifdef CONFIG_IP_ROUTE_CLASSID 313static int rt_acct_proc_show(struct seq_file *m, void *v) 314{ 315 struct ip_rt_acct *dst, *src; 316 unsigned int i, j; 317 318 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 319 if (!dst) 320 return -ENOMEM; 321 322 for_each_possible_cpu(i) { 323 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 324 for (j = 0; j < 256; j++) { 325 dst[j].o_bytes += src[j].o_bytes; 326 dst[j].o_packets += src[j].o_packets; 327 dst[j].i_bytes += src[j].i_bytes; 328 dst[j].i_packets += src[j].i_packets; 329 } 330 } 331 332 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 333 kfree(dst); 334 return 0; 335} 336#endif 337 338static int __net_init ip_rt_do_proc_init(struct net *net) 339{ 340 struct proc_dir_entry *pde; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 343 &rt_cache_seq_ops); 344 if (!pde) 345 goto err1; 346 347 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 348 &rt_cpu_seq_ops); 349 if (!pde) 350 goto err2; 351 352#ifdef CONFIG_IP_ROUTE_CLASSID 353 pde = proc_create_single("rt_acct", 0, net->proc_net, 354 rt_acct_proc_show); 355 if (!pde) 356 goto err3; 357#endif 358 return 0; 359 360#ifdef CONFIG_IP_ROUTE_CLASSID 361err3: 362 remove_proc_entry("rt_cache", net->proc_net_stat); 363#endif 364err2: 365 remove_proc_entry("rt_cache", net->proc_net); 366err1: 367 return -ENOMEM; 368} 369 370static void __net_exit ip_rt_do_proc_exit(struct net *net) 371{ 372 remove_proc_entry("rt_cache", net->proc_net_stat); 373 remove_proc_entry("rt_cache", net->proc_net); 374#ifdef CONFIG_IP_ROUTE_CLASSID 375 remove_proc_entry("rt_acct", net->proc_net); 376#endif 377} 378 379static struct pernet_operations ip_rt_proc_ops __net_initdata = { 380 .init = ip_rt_do_proc_init, 381 .exit = ip_rt_do_proc_exit, 382}; 383 384static int __init ip_rt_proc_init(void) 385{ 386 return register_pernet_subsys(&ip_rt_proc_ops); 387} 388 389#else 390static inline int ip_rt_proc_init(void) 391{ 392 return 0; 393} 394#endif /* CONFIG_PROC_FS */ 395 396static inline bool rt_is_expired(const struct rtable *rth) 397{ 398 bool res; 399 400 rcu_read_lock(); 401 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev)); 402 rcu_read_unlock(); 403 404 return res; 405} 406 407void rt_cache_flush(struct net *net) 408{ 409 rt_genid_bump_ipv4(net); 410} 411 412static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 413 struct sk_buff *skb, 414 const void *daddr) 415{ 416 const struct rtable *rt = container_of(dst, struct rtable, dst); 417 struct net_device *dev; 418 struct neighbour *n; 419 420 rcu_read_lock(); 421 dev = dst_dev_rcu(dst); 422 if (likely(rt->rt_gw_family == AF_INET)) { 423 n = ip_neigh_gw4(dev, rt->rt_gw4); 424 } else if (rt->rt_gw_family == AF_INET6) { 425 n = ip_neigh_gw6(dev, &rt->rt_gw6); 426 } else { 427 __be32 pkey; 428 429 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 430 n = ip_neigh_gw4(dev, pkey); 431 } 432 433 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 434 n = NULL; 435 436 rcu_read_unlock(); 437 438 return n; 439} 440 441static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 442{ 443 const struct rtable *rt = container_of(dst, struct rtable, dst); 444 struct net_device *dev = dst_dev(dst); 445 const __be32 *pkey = daddr; 446 447 if (rt->rt_gw_family == AF_INET) { 448 pkey = (const __be32 *)&rt->rt_gw4; 449 } else if (rt->rt_gw_family == AF_INET6) { 450 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 451 } else if (!daddr || 452 (rt->rt_flags & 453 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 454 return; 455 } 456 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 457} 458 459/* Hash tables of size 2048..262144 depending on RAM size. 460 * Each bucket uses 8 bytes. 461 */ 462static u32 ip_idents_mask __read_mostly; 463static atomic_t *ip_idents __read_mostly; 464static u32 *ip_tstamps __read_mostly; 465 466/* In order to protect privacy, we add a perturbation to identifiers 467 * if one generator is seldom used. This makes hard for an attacker 468 * to infer how many packets were sent between two points in time. 469 */ 470static u32 ip_idents_reserve(u32 hash, int segs) 471{ 472 u32 bucket, old, now = (u32)jiffies; 473 atomic_t *p_id; 474 u32 *p_tstamp; 475 u32 delta = 0; 476 477 bucket = hash & ip_idents_mask; 478 p_tstamp = ip_tstamps + bucket; 479 p_id = ip_idents + bucket; 480 old = READ_ONCE(*p_tstamp); 481 482 if (old != now && cmpxchg(p_tstamp, old, now) == old) 483 delta = get_random_u32_below(now - old); 484 485 /* If UBSAN reports an error there, please make sure your compiler 486 * supports -fno-strict-overflow before reporting it that was a bug 487 * in UBSAN, and it has been fixed in GCC-8. 488 */ 489 return atomic_add_return(segs + delta, p_id) - segs; 490} 491 492void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 493{ 494 u32 hash, id; 495 496 /* Note the following code is not safe, but this is okay. */ 497 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 498 get_random_bytes(&net->ipv4.ip_id_key, 499 sizeof(net->ipv4.ip_id_key)); 500 501 hash = siphash_3u32((__force u32)iph->daddr, 502 (__force u32)iph->saddr, 503 iph->protocol, 504 &net->ipv4.ip_id_key); 505 id = ip_idents_reserve(hash, segs); 506 iph->id = htons(id); 507} 508EXPORT_SYMBOL(__ip_select_ident); 509 510static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 511 const struct sock *sk, const struct iphdr *iph, 512 int oif, __u8 tos, u8 prot, u32 mark, 513 int flow_flags) 514{ 515 __u8 scope = RT_SCOPE_UNIVERSE; 516 517 if (sk) { 518 oif = sk->sk_bound_dev_if; 519 mark = READ_ONCE(sk->sk_mark); 520 tos = ip_sock_rt_tos(sk); 521 scope = ip_sock_rt_scope(sk); 522 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 523 sk->sk_protocol; 524 } 525 526 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope, 527 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 528 sock_net_uid(net, sk)); 529} 530 531static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 532 const struct sock *sk) 533{ 534 const struct net *net = dev_net(skb->dev); 535 const struct iphdr *iph = ip_hdr(skb); 536 int oif = skb->dev->ifindex; 537 u8 prot = iph->protocol; 538 u32 mark = skb->mark; 539 __u8 tos = iph->tos; 540 541 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 542} 543 544static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 545{ 546 const struct inet_sock *inet = inet_sk(sk); 547 const struct ip_options_rcu *inet_opt; 548 __be32 daddr = inet->inet_daddr; 549 550 rcu_read_lock(); 551 inet_opt = rcu_dereference(inet->inet_opt); 552 if (inet_opt && inet_opt->opt.srr) 553 daddr = inet_opt->opt.faddr; 554 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 555 ip_sock_rt_tos(sk), 556 ip_sock_rt_scope(sk), 557 inet_test_bit(HDRINCL, sk) ? 558 IPPROTO_RAW : sk->sk_protocol, 559 inet_sk_flowi_flags(sk), 560 daddr, inet->inet_saddr, 0, 0, 561 sk_uid(sk)); 562 rcu_read_unlock(); 563} 564 565static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 566 const struct sk_buff *skb) 567{ 568 if (skb) 569 build_skb_flow_key(fl4, skb, sk); 570 else 571 build_sk_flow_key(fl4, sk); 572} 573 574static DEFINE_SPINLOCK(fnhe_lock); 575 576static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 577{ 578 struct rtable *rt; 579 580 rt = rcu_dereference(fnhe->fnhe_rth_input); 581 if (rt) { 582 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 583 dst_dev_put(&rt->dst); 584 dst_release(&rt->dst); 585 } 586 rt = rcu_dereference(fnhe->fnhe_rth_output); 587 if (rt) { 588 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 589 dst_dev_put(&rt->dst); 590 dst_release(&rt->dst); 591 } 592} 593 594static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 595{ 596 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 597 struct fib_nh_exception *fnhe, *oldest = NULL; 598 599 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 600 fnhe = rcu_dereference_protected(*fnhe_p, 601 lockdep_is_held(&fnhe_lock)); 602 if (!fnhe) 603 break; 604 if (!oldest || 605 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 606 oldest = fnhe; 607 oldest_p = fnhe_p; 608 } 609 } 610 611 /* Clear oldest->fnhe_daddr to prevent this fnhe from being 612 * rebound with new dsts in rt_bind_exception(). 613 */ 614 oldest->fnhe_daddr = 0; 615 fnhe_flush_routes(oldest); 616 *oldest_p = oldest->fnhe_next; 617 kfree_rcu(oldest, rcu); 618} 619 620static u32 fnhe_hashfun(__be32 daddr) 621{ 622 static siphash_aligned_key_t fnhe_hash_key; 623 u64 hval; 624 625 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 626 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 627 return hash_64(hval, FNHE_HASH_SHIFT); 628} 629 630static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 631{ 632 rt->rt_pmtu = fnhe->fnhe_pmtu; 633 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 634 rt->dst.expires = fnhe->fnhe_expires; 635 636 if (fnhe->fnhe_gw) { 637 rt->rt_flags |= RTCF_REDIRECTED; 638 rt->rt_uses_gateway = 1; 639 rt->rt_gw_family = AF_INET; 640 rt->rt_gw4 = fnhe->fnhe_gw; 641 } 642} 643 644static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 645 __be32 gw, u32 pmtu, bool lock, 646 unsigned long expires) 647{ 648 struct fnhe_hash_bucket *hash; 649 struct fib_nh_exception *fnhe; 650 struct rtable *rt; 651 u32 genid, hval; 652 unsigned int i; 653 int depth; 654 655 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 656 hval = fnhe_hashfun(daddr); 657 658 spin_lock_bh(&fnhe_lock); 659 660 hash = rcu_dereference(nhc->nhc_exceptions); 661 if (!hash) { 662 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 663 if (!hash) 664 goto out_unlock; 665 rcu_assign_pointer(nhc->nhc_exceptions, hash); 666 } 667 668 hash += hval; 669 670 depth = 0; 671 for (fnhe = rcu_dereference(hash->chain); fnhe; 672 fnhe = rcu_dereference(fnhe->fnhe_next)) { 673 if (fnhe->fnhe_daddr == daddr) 674 break; 675 depth++; 676 } 677 678 if (fnhe) { 679 if (fnhe->fnhe_genid != genid) 680 fnhe->fnhe_genid = genid; 681 if (gw) 682 fnhe->fnhe_gw = gw; 683 if (pmtu) { 684 fnhe->fnhe_pmtu = pmtu; 685 fnhe->fnhe_mtu_locked = lock; 686 } 687 fnhe->fnhe_expires = max(1UL, expires); 688 /* Update all cached dsts too */ 689 rt = rcu_dereference(fnhe->fnhe_rth_input); 690 if (rt) 691 fill_route_from_fnhe(rt, fnhe); 692 rt = rcu_dereference(fnhe->fnhe_rth_output); 693 if (rt) 694 fill_route_from_fnhe(rt, fnhe); 695 } else { 696 /* Randomize max depth to avoid some side channels attacks. */ 697 int max_depth = FNHE_RECLAIM_DEPTH + 698 get_random_u32_below(FNHE_RECLAIM_DEPTH); 699 700 while (depth > max_depth) { 701 fnhe_remove_oldest(hash); 702 depth--; 703 } 704 705 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 706 if (!fnhe) 707 goto out_unlock; 708 709 fnhe->fnhe_next = hash->chain; 710 711 fnhe->fnhe_genid = genid; 712 fnhe->fnhe_daddr = daddr; 713 fnhe->fnhe_gw = gw; 714 fnhe->fnhe_pmtu = pmtu; 715 fnhe->fnhe_mtu_locked = lock; 716 fnhe->fnhe_expires = max(1UL, expires); 717 718 rcu_assign_pointer(hash->chain, fnhe); 719 720 /* Exception created; mark the cached routes for the nexthop 721 * stale, so anyone caching it rechecks if this exception 722 * applies to them. 723 */ 724 rt = rcu_dereference(nhc->nhc_rth_input); 725 if (rt) 726 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 727 728 for_each_possible_cpu(i) { 729 struct rtable __rcu **prt; 730 731 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 732 rt = rcu_dereference(*prt); 733 if (rt) 734 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 735 } 736 } 737 738 fnhe->fnhe_stamp = jiffies; 739 740out_unlock: 741 spin_unlock_bh(&fnhe_lock); 742} 743 744static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 745 bool kill_route) 746{ 747 __be32 new_gw = icmp_hdr(skb)->un.gateway; 748 __be32 old_gw = ip_hdr(skb)->saddr; 749 struct net_device *dev = skb->dev; 750 struct in_device *in_dev; 751 struct fib_result res; 752 struct neighbour *n; 753 struct net *net; 754 755 switch (icmp_hdr(skb)->code & 7) { 756 case ICMP_REDIR_NET: 757 case ICMP_REDIR_NETTOS: 758 case ICMP_REDIR_HOST: 759 case ICMP_REDIR_HOSTTOS: 760 break; 761 762 default: 763 return; 764 } 765 766 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 767 return; 768 769 in_dev = __in_dev_get_rcu(dev); 770 if (!in_dev) 771 return; 772 773 net = dev_net(dev); 774 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 775 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 776 ipv4_is_zeronet(new_gw)) 777 goto reject_redirect; 778 779 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 780 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 781 goto reject_redirect; 782 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 783 goto reject_redirect; 784 } else { 785 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 786 goto reject_redirect; 787 } 788 789 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 790 if (!n) 791 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 792 if (!IS_ERR(n)) { 793 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 794 neigh_event_send(n, NULL); 795 } else { 796 if (fib_lookup(net, fl4, &res, 0) == 0) { 797 struct fib_nh_common *nhc; 798 799 fib_select_path(net, &res, fl4, skb); 800 nhc = FIB_RES_NHC(res); 801 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 802 0, false, 803 jiffies + ip_rt_gc_timeout); 804 } 805 if (kill_route) 806 WRITE_ONCE(rt->dst.obsolete, DST_OBSOLETE_KILL); 807 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 808 } 809 neigh_release(n); 810 } 811 return; 812 813reject_redirect: 814#ifdef CONFIG_IP_ROUTE_VERBOSE 815 if (IN_DEV_LOG_MARTIANS(in_dev)) { 816 const struct iphdr *iph = (const struct iphdr *) skb->data; 817 __be32 daddr = iph->daddr; 818 __be32 saddr = iph->saddr; 819 820 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 821 " Advised path = %pI4 -> %pI4\n", 822 &old_gw, dev->name, &new_gw, 823 &saddr, &daddr); 824 } 825#endif 826 ; 827} 828 829static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 830{ 831 struct rtable *rt; 832 struct flowi4 fl4; 833 const struct iphdr *iph = (const struct iphdr *) skb->data; 834 struct net *net = dev_net(skb->dev); 835 int oif = skb->dev->ifindex; 836 u8 prot = iph->protocol; 837 u32 mark = skb->mark; 838 __u8 tos = iph->tos; 839 840 rt = dst_rtable(dst); 841 842 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 843 __ip_do_redirect(rt, skb, &fl4, true); 844} 845 846static void ipv4_negative_advice(struct sock *sk, 847 struct dst_entry *dst) 848{ 849 struct rtable *rt = dst_rtable(dst); 850 851 if ((READ_ONCE(dst->obsolete) > 0) || 852 (rt->rt_flags & RTCF_REDIRECTED) || 853 READ_ONCE(rt->dst.expires)) 854 sk_dst_reset(sk); 855} 856 857/* 858 * Algorithm: 859 * 1. The first ip_rt_redirect_number redirects are sent 860 * with exponential backoff, then we stop sending them at all, 861 * assuming that the host ignores our redirects. 862 * 2. If we did not see packets requiring redirects 863 * during ip_rt_redirect_silence, we assume that the host 864 * forgot redirected route and start to send redirects again. 865 * 866 * This algorithm is much cheaper and more intelligent than dumb load limiting 867 * in icmp.c. 868 * 869 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 870 * and "frag. need" (breaks PMTU discovery) in icmp.c. 871 */ 872 873void ip_rt_send_redirect(struct sk_buff *skb) 874{ 875 struct rtable *rt = skb_rtable(skb); 876 struct in_device *in_dev; 877 struct inet_peer *peer; 878 struct net *net; 879 int log_martians; 880 int vif; 881 882 rcu_read_lock(); 883 in_dev = __in_dev_get_rcu(rt->dst.dev); 884 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 885 rcu_read_unlock(); 886 return; 887 } 888 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 889 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 890 891 net = dev_net(rt->dst.dev); 892 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 893 if (!peer) { 894 rcu_read_unlock(); 895 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 896 rt_nexthop(rt, ip_hdr(skb)->daddr)); 897 return; 898 } 899 900 /* No redirected packets during ip_rt_redirect_silence; 901 * reset the algorithm. 902 */ 903 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 904 peer->rate_tokens = 0; 905 peer->n_redirects = 0; 906 } 907 908 /* Too many ignored redirects; do not send anything 909 * set dst.rate_last to the last seen redirected packet. 910 */ 911 if (peer->n_redirects >= ip_rt_redirect_number) { 912 peer->rate_last = jiffies; 913 goto out_unlock; 914 } 915 916 /* Check for load limit; set rate_last to the latest sent 917 * redirect. 918 */ 919 if (peer->n_redirects == 0 || 920 time_after(jiffies, 921 (peer->rate_last + 922 (ip_rt_redirect_load << peer->n_redirects)))) { 923 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 924 925 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 926 peer->rate_last = jiffies; 927 ++peer->n_redirects; 928 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 929 peer->n_redirects == ip_rt_redirect_number) 930 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 931 &ip_hdr(skb)->saddr, inet_iif(skb), 932 &ip_hdr(skb)->daddr, &gw); 933 } 934out_unlock: 935 rcu_read_unlock(); 936} 937 938static int ip_error(struct sk_buff *skb) 939{ 940 struct rtable *rt = skb_rtable(skb); 941 struct net_device *dev = skb->dev; 942 struct in_device *in_dev; 943 struct inet_peer *peer; 944 unsigned long now; 945 struct net *net; 946 SKB_DR(reason); 947 bool send; 948 int code; 949 950 if (netif_is_l3_master(skb->dev)) { 951 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 952 if (!dev) 953 goto out; 954 } 955 956 in_dev = __in_dev_get_rcu(dev); 957 958 /* IP on this device is disabled. */ 959 if (!in_dev) 960 goto out; 961 962 net = dev_net(rt->dst.dev); 963 if (!IN_DEV_FORWARD(in_dev)) { 964 switch (rt->dst.error) { 965 case EHOSTUNREACH: 966 SKB_DR_SET(reason, IP_INADDRERRORS); 967 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 968 break; 969 970 case ENETUNREACH: 971 SKB_DR_SET(reason, IP_INNOROUTES); 972 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 973 break; 974 } 975 goto out; 976 } 977 978 switch (rt->dst.error) { 979 case EINVAL: 980 default: 981 goto out; 982 case EHOSTUNREACH: 983 code = ICMP_HOST_UNREACH; 984 break; 985 case ENETUNREACH: 986 code = ICMP_NET_UNREACH; 987 SKB_DR_SET(reason, IP_INNOROUTES); 988 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 989 break; 990 case EACCES: 991 code = ICMP_PKT_FILTERED; 992 break; 993 } 994 995 rcu_read_lock(); 996 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 997 l3mdev_master_ifindex_rcu(skb->dev)); 998 send = true; 999 if (peer) { 1000 now = jiffies; 1001 peer->rate_tokens += now - peer->rate_last; 1002 if (peer->rate_tokens > ip_rt_error_burst) 1003 peer->rate_tokens = ip_rt_error_burst; 1004 peer->rate_last = now; 1005 if (peer->rate_tokens >= ip_rt_error_cost) 1006 peer->rate_tokens -= ip_rt_error_cost; 1007 else 1008 send = false; 1009 } 1010 rcu_read_unlock(); 1011 1012 if (send) 1013 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1014 1015out: kfree_skb_reason(skb, reason); 1016 return 0; 1017} 1018 1019static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1020{ 1021 struct dst_entry *dst = &rt->dst; 1022 struct fib_result res; 1023 bool lock = false; 1024 struct net *net; 1025 u32 old_mtu; 1026 1027 if (ip_mtu_locked(dst)) 1028 return; 1029 1030 old_mtu = ipv4_mtu(dst); 1031 if (old_mtu < mtu) 1032 return; 1033 1034 rcu_read_lock(); 1035 net = dst_dev_net_rcu(dst); 1036 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1037 lock = true; 1038 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1039 } 1040 1041 if (rt->rt_pmtu == mtu && !lock && 1042 time_before(jiffies, READ_ONCE(dst->expires) - 1043 net->ipv4.ip_rt_mtu_expires / 2)) 1044 goto out; 1045 1046 if (fib_lookup(net, fl4, &res, 0) == 0) { 1047 struct fib_nh_common *nhc; 1048 1049 fib_select_path(net, &res, fl4, NULL); 1050#ifdef CONFIG_IP_ROUTE_MULTIPATH 1051 if (fib_info_num_path(res.fi) > 1) { 1052 int nhsel; 1053 1054 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1055 nhc = fib_info_nhc(res.fi, nhsel); 1056 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1057 jiffies + net->ipv4.ip_rt_mtu_expires); 1058 } 1059 goto out; 1060 } 1061#endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1062 nhc = FIB_RES_NHC(res); 1063 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1064 jiffies + net->ipv4.ip_rt_mtu_expires); 1065 } 1066out: 1067 rcu_read_unlock(); 1068} 1069 1070static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1071 struct sk_buff *skb, u32 mtu, 1072 bool confirm_neigh) 1073{ 1074 struct rtable *rt = dst_rtable(dst); 1075 struct flowi4 fl4; 1076 1077 ip_rt_build_flow_key(&fl4, sk, skb); 1078 1079 /* Don't make lookup fail for bridged encapsulations */ 1080 if (skb && netif_is_any_bridge_port(skb->dev)) 1081 fl4.flowi4_oif = 0; 1082 1083 __ip_rt_update_pmtu(rt, &fl4, mtu); 1084} 1085 1086void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1087 int oif, u8 protocol) 1088{ 1089 const struct iphdr *iph = (const struct iphdr *)skb->data; 1090 struct flowi4 fl4; 1091 struct rtable *rt; 1092 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1093 1094 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1095 0); 1096 rt = __ip_route_output_key(net, &fl4); 1097 if (!IS_ERR(rt)) { 1098 __ip_rt_update_pmtu(rt, &fl4, mtu); 1099 ip_rt_put(rt); 1100 } 1101} 1102EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1103 1104static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1105{ 1106 const struct iphdr *iph = (const struct iphdr *)skb->data; 1107 struct flowi4 fl4; 1108 struct rtable *rt; 1109 1110 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1111 1112 if (!fl4.flowi4_mark) 1113 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1114 1115 rt = __ip_route_output_key(sock_net(sk), &fl4); 1116 if (!IS_ERR(rt)) { 1117 __ip_rt_update_pmtu(rt, &fl4, mtu); 1118 ip_rt_put(rt); 1119 } 1120} 1121 1122void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1123{ 1124 const struct iphdr *iph = (const struct iphdr *)skb->data; 1125 struct flowi4 fl4; 1126 struct rtable *rt; 1127 struct dst_entry *odst = NULL; 1128 bool new = false; 1129 struct net *net = sock_net(sk); 1130 1131 bh_lock_sock(sk); 1132 1133 if (!ip_sk_accept_pmtu(sk)) 1134 goto out; 1135 1136 odst = sk_dst_get(sk); 1137 1138 if (sock_owned_by_user(sk) || !odst) { 1139 __ipv4_sk_update_pmtu(skb, sk, mtu); 1140 goto out; 1141 } 1142 1143 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1144 1145 rt = dst_rtable(odst); 1146 if (READ_ONCE(odst->obsolete) && !odst->ops->check(odst, 0)) { 1147 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1148 if (IS_ERR(rt)) 1149 goto out; 1150 1151 new = true; 1152 } 1153 1154 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1155 1156 if (!dst_check(&rt->dst, 0)) { 1157 if (new) 1158 dst_release(&rt->dst); 1159 1160 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1161 if (IS_ERR(rt)) 1162 goto out; 1163 1164 new = true; 1165 } 1166 1167 if (new) 1168 sk_dst_set(sk, &rt->dst); 1169 1170out: 1171 bh_unlock_sock(sk); 1172 dst_release(odst); 1173} 1174EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1175 1176void ipv4_redirect(struct sk_buff *skb, struct net *net, 1177 int oif, u8 protocol) 1178{ 1179 const struct iphdr *iph = (const struct iphdr *)skb->data; 1180 struct flowi4 fl4; 1181 struct rtable *rt; 1182 1183 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1184 rt = __ip_route_output_key(net, &fl4); 1185 if (!IS_ERR(rt)) { 1186 __ip_do_redirect(rt, skb, &fl4, false); 1187 ip_rt_put(rt); 1188 } 1189} 1190EXPORT_SYMBOL_GPL(ipv4_redirect); 1191 1192void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1193{ 1194 const struct iphdr *iph = (const struct iphdr *)skb->data; 1195 struct flowi4 fl4; 1196 struct rtable *rt; 1197 struct net *net = sock_net(sk); 1198 1199 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1200 rt = __ip_route_output_key(net, &fl4); 1201 if (!IS_ERR(rt)) { 1202 __ip_do_redirect(rt, skb, &fl4, false); 1203 ip_rt_put(rt); 1204 } 1205} 1206EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1207 1208INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1209 u32 cookie) 1210{ 1211 struct rtable *rt = dst_rtable(dst); 1212 1213 /* All IPV4 dsts are created with ->obsolete set to the value 1214 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1215 * into this function always. 1216 * 1217 * When a PMTU/redirect information update invalidates a route, 1218 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1219 * DST_OBSOLETE_DEAD. 1220 */ 1221 if (READ_ONCE(dst->obsolete) != DST_OBSOLETE_FORCE_CHK || 1222 rt_is_expired(rt)) 1223 return NULL; 1224 return dst; 1225} 1226EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1227 1228static void ipv4_send_dest_unreach(struct sk_buff *skb) 1229{ 1230 struct inet_skb_parm parm; 1231 struct net_device *dev; 1232 int res; 1233 1234 /* Recompile ip options since IPCB may not be valid anymore. 1235 * Also check we have a reasonable ipv4 header. 1236 */ 1237 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1238 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1239 return; 1240 1241 memset(&parm, 0, sizeof(parm)); 1242 if (ip_hdr(skb)->ihl > 5) { 1243 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1244 return; 1245 parm.opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1246 1247 rcu_read_lock(); 1248 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1249 res = __ip_options_compile(dev_net(dev), &parm.opt, skb, NULL); 1250 rcu_read_unlock(); 1251 1252 if (res) 1253 return; 1254 } 1255 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &parm); 1256} 1257 1258static void ipv4_link_failure(struct sk_buff *skb) 1259{ 1260 struct rtable *rt; 1261 1262 ipv4_send_dest_unreach(skb); 1263 1264 rt = skb_rtable(skb); 1265 if (rt) 1266 dst_set_expires(&rt->dst, 0); 1267} 1268 1269static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1270{ 1271 pr_debug("%s: %pI4 -> %pI4, %s\n", 1272 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1273 skb->dev ? skb->dev->name : "?"); 1274 kfree_skb(skb); 1275 WARN_ON(1); 1276 return 0; 1277} 1278 1279/* 1280 * We do not cache source address of outgoing interface, 1281 * because it is used only by IP RR, TS and SRR options, 1282 * so that it out of fast path. 1283 * 1284 * BTW remember: "addr" is allowed to be not aligned 1285 * in IP options! 1286 */ 1287 1288void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1289{ 1290 __be32 src; 1291 1292 if (rt_is_output_route(rt)) 1293 src = ip_hdr(skb)->saddr; 1294 else { 1295 struct fib_result res; 1296 struct iphdr *iph = ip_hdr(skb); 1297 struct flowi4 fl4 = { 1298 .daddr = iph->daddr, 1299 .saddr = iph->saddr, 1300 .flowi4_dscp = ip4h_dscp(iph), 1301 .flowi4_oif = rt->dst.dev->ifindex, 1302 .flowi4_iif = skb->dev->ifindex, 1303 .flowi4_mark = skb->mark, 1304 }; 1305 1306 rcu_read_lock(); 1307 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1308 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1309 else 1310 src = inet_select_addr(rt->dst.dev, 1311 rt_nexthop(rt, iph->daddr), 1312 RT_SCOPE_UNIVERSE); 1313 rcu_read_unlock(); 1314 } 1315 memcpy(addr, &src, 4); 1316} 1317 1318#ifdef CONFIG_IP_ROUTE_CLASSID 1319static void set_class_tag(struct rtable *rt, u32 tag) 1320{ 1321 if (!(rt->dst.tclassid & 0xFFFF)) 1322 rt->dst.tclassid |= tag & 0xFFFF; 1323 if (!(rt->dst.tclassid & 0xFFFF0000)) 1324 rt->dst.tclassid |= tag & 0xFFFF0000; 1325} 1326#endif 1327 1328static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1329{ 1330 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1331 unsigned int advmss; 1332 struct net *net; 1333 1334 rcu_read_lock(); 1335 net = dst_dev_net_rcu(dst); 1336 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1337 net->ipv4.ip_rt_min_advmss); 1338 rcu_read_unlock(); 1339 1340 return min(advmss, IPV4_MAX_PMTU - header_size); 1341} 1342 1343INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1344{ 1345 return ip_dst_mtu_maybe_forward(dst, false); 1346} 1347EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1348 1349static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1350{ 1351 struct fnhe_hash_bucket *hash; 1352 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1353 u32 hval = fnhe_hashfun(daddr); 1354 1355 spin_lock_bh(&fnhe_lock); 1356 1357 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1358 lockdep_is_held(&fnhe_lock)); 1359 hash += hval; 1360 1361 fnhe_p = &hash->chain; 1362 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1363 while (fnhe) { 1364 if (fnhe->fnhe_daddr == daddr) { 1365 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1366 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1367 /* set fnhe_daddr to 0 to ensure it won't bind with 1368 * new dsts in rt_bind_exception(). 1369 */ 1370 fnhe->fnhe_daddr = 0; 1371 fnhe_flush_routes(fnhe); 1372 kfree_rcu(fnhe, rcu); 1373 break; 1374 } 1375 fnhe_p = &fnhe->fnhe_next; 1376 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1377 lockdep_is_held(&fnhe_lock)); 1378 } 1379 1380 spin_unlock_bh(&fnhe_lock); 1381} 1382 1383static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1384 __be32 daddr) 1385{ 1386 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1387 struct fib_nh_exception *fnhe; 1388 u32 hval; 1389 1390 if (!hash) 1391 return NULL; 1392 1393 hval = fnhe_hashfun(daddr); 1394 1395 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1396 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1397 if (fnhe->fnhe_daddr == daddr) { 1398 if (fnhe->fnhe_expires && 1399 time_after(jiffies, fnhe->fnhe_expires)) { 1400 ip_del_fnhe(nhc, daddr); 1401 break; 1402 } 1403 return fnhe; 1404 } 1405 } 1406 return NULL; 1407} 1408 1409/* MTU selection: 1410 * 1. mtu on route is locked - use it 1411 * 2. mtu from nexthop exception 1412 * 3. mtu from egress device 1413 */ 1414 1415u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1416{ 1417 struct fib_nh_common *nhc = res->nhc; 1418 struct net_device *dev = nhc->nhc_dev; 1419 struct fib_info *fi = res->fi; 1420 u32 mtu = 0; 1421 1422 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1423 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1424 mtu = fi->fib_mtu; 1425 1426 if (likely(!mtu)) { 1427 struct fib_nh_exception *fnhe; 1428 1429 fnhe = find_exception(nhc, daddr); 1430 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1431 mtu = fnhe->fnhe_pmtu; 1432 } 1433 1434 if (likely(!mtu)) 1435 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1436 1437 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1438} 1439 1440static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1441 __be32 daddr, const bool do_cache) 1442{ 1443 bool ret = false; 1444 1445 spin_lock_bh(&fnhe_lock); 1446 1447 if (daddr == fnhe->fnhe_daddr) { 1448 struct rtable __rcu **porig; 1449 struct rtable *orig; 1450 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1451 1452 if (rt_is_input_route(rt)) 1453 porig = &fnhe->fnhe_rth_input; 1454 else 1455 porig = &fnhe->fnhe_rth_output; 1456 orig = rcu_dereference(*porig); 1457 1458 if (fnhe->fnhe_genid != genid) { 1459 fnhe->fnhe_genid = genid; 1460 fnhe->fnhe_gw = 0; 1461 fnhe->fnhe_pmtu = 0; 1462 fnhe->fnhe_expires = 0; 1463 fnhe->fnhe_mtu_locked = false; 1464 fnhe_flush_routes(fnhe); 1465 orig = NULL; 1466 } 1467 fill_route_from_fnhe(rt, fnhe); 1468 if (!rt->rt_gw4) { 1469 rt->rt_gw4 = daddr; 1470 rt->rt_gw_family = AF_INET; 1471 } 1472 1473 if (do_cache) { 1474 dst_hold(&rt->dst); 1475 rcu_assign_pointer(*porig, rt); 1476 if (orig) { 1477 dst_dev_put(&orig->dst); 1478 dst_release(&orig->dst); 1479 } 1480 ret = true; 1481 } 1482 1483 fnhe->fnhe_stamp = jiffies; 1484 } 1485 spin_unlock_bh(&fnhe_lock); 1486 1487 return ret; 1488} 1489 1490static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1491{ 1492 struct rtable *orig, *prev, **p; 1493 bool ret = true; 1494 1495 if (rt_is_input_route(rt)) { 1496 p = (struct rtable **)&nhc->nhc_rth_input; 1497 } else { 1498 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1499 } 1500 orig = *p; 1501 1502 /* hold dst before doing cmpxchg() to avoid race condition 1503 * on this dst 1504 */ 1505 dst_hold(&rt->dst); 1506 prev = cmpxchg(p, orig, rt); 1507 if (prev == orig) { 1508 if (orig) { 1509 rt_add_uncached_list(orig); 1510 dst_release(&orig->dst); 1511 } 1512 } else { 1513 dst_release(&rt->dst); 1514 ret = false; 1515 } 1516 1517 return ret; 1518} 1519 1520struct uncached_list { 1521 spinlock_t lock; 1522 struct list_head head; 1523}; 1524 1525static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1526 1527void rt_add_uncached_list(struct rtable *rt) 1528{ 1529 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1530 1531 rt->dst.rt_uncached_list = ul; 1532 1533 spin_lock_bh(&ul->lock); 1534 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1535 spin_unlock_bh(&ul->lock); 1536} 1537 1538void rt_del_uncached_list(struct rtable *rt) 1539{ 1540 struct uncached_list *ul = rt->dst.rt_uncached_list; 1541 1542 if (ul) { 1543 spin_lock_bh(&ul->lock); 1544 list_del_init(&rt->dst.rt_uncached); 1545 spin_unlock_bh(&ul->lock); 1546 } 1547} 1548 1549static void ipv4_dst_destroy(struct dst_entry *dst) 1550{ 1551 ip_dst_metrics_put(dst); 1552 rt_del_uncached_list(dst_rtable(dst)); 1553} 1554 1555void rt_flush_dev(struct net_device *dev) 1556{ 1557 struct rtable *rt, *safe; 1558 int cpu; 1559 1560 for_each_possible_cpu(cpu) { 1561 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1562 1563 if (list_empty(&ul->head)) 1564 continue; 1565 1566 spin_lock_bh(&ul->lock); 1567 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1568 if (rt->dst.dev != dev) 1569 continue; 1570 rt->dst.dev = blackhole_netdev; 1571 netdev_ref_replace(dev, blackhole_netdev, 1572 &rt->dst.dev_tracker, GFP_ATOMIC); 1573 list_del_init(&rt->dst.rt_uncached); 1574 } 1575 spin_unlock_bh(&ul->lock); 1576 } 1577} 1578 1579static bool rt_cache_valid(const struct rtable *rt) 1580{ 1581 return rt && 1582 READ_ONCE(rt->dst.obsolete) == DST_OBSOLETE_FORCE_CHK && 1583 !rt_is_expired(rt); 1584} 1585 1586static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1587 const struct fib_result *res, 1588 struct fib_nh_exception *fnhe, 1589 struct fib_info *fi, u16 type, u32 itag, 1590 const bool do_cache) 1591{ 1592 bool cached = false; 1593 1594 if (fi) { 1595 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1596 1597 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1598 rt->rt_uses_gateway = 1; 1599 rt->rt_gw_family = nhc->nhc_gw_family; 1600 /* only INET and INET6 are supported */ 1601 if (likely(nhc->nhc_gw_family == AF_INET)) 1602 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1603 else 1604 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1605 } 1606 1607 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1608 1609#ifdef CONFIG_IP_ROUTE_CLASSID 1610 if (nhc->nhc_family == AF_INET) { 1611 struct fib_nh *nh; 1612 1613 nh = container_of(nhc, struct fib_nh, nh_common); 1614 rt->dst.tclassid = nh->nh_tclassid; 1615 } 1616#endif 1617 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1618 if (unlikely(fnhe)) 1619 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1620 else if (do_cache) 1621 cached = rt_cache_route(nhc, rt); 1622 if (unlikely(!cached)) { 1623 /* Routes we intend to cache in nexthop exception or 1624 * FIB nexthop have the DST_NOCACHE bit clear. 1625 * However, if we are unsuccessful at storing this 1626 * route into the cache we really need to set it. 1627 */ 1628 if (!rt->rt_gw4) { 1629 rt->rt_gw_family = AF_INET; 1630 rt->rt_gw4 = daddr; 1631 } 1632 rt_add_uncached_list(rt); 1633 } 1634 } else 1635 rt_add_uncached_list(rt); 1636 1637#ifdef CONFIG_IP_ROUTE_CLASSID 1638#ifdef CONFIG_IP_MULTIPLE_TABLES 1639 set_class_tag(rt, res->tclassid); 1640#endif 1641 set_class_tag(rt, itag); 1642#endif 1643} 1644 1645struct rtable *rt_dst_alloc(struct net_device *dev, 1646 unsigned int flags, u16 type, 1647 bool noxfrm) 1648{ 1649 struct rtable *rt; 1650 1651 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1652 (noxfrm ? DST_NOXFRM : 0)); 1653 1654 if (rt) { 1655 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1656 rt->rt_flags = flags; 1657 rt->rt_type = type; 1658 rt->rt_is_input = 0; 1659 rt->rt_iif = 0; 1660 rt->rt_pmtu = 0; 1661 rt->rt_mtu_locked = 0; 1662 rt->rt_uses_gateway = 0; 1663 rt->rt_gw_family = 0; 1664 rt->rt_gw4 = 0; 1665 1666 rt->dst.output = ip_output; 1667 if (flags & RTCF_LOCAL) 1668 rt->dst.input = ip_local_deliver; 1669 } 1670 1671 return rt; 1672} 1673EXPORT_SYMBOL(rt_dst_alloc); 1674 1675struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1676{ 1677 struct rtable *new_rt; 1678 1679 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1680 rt->dst.flags); 1681 1682 if (new_rt) { 1683 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1684 new_rt->rt_flags = rt->rt_flags; 1685 new_rt->rt_type = rt->rt_type; 1686 new_rt->rt_is_input = rt->rt_is_input; 1687 new_rt->rt_iif = rt->rt_iif; 1688 new_rt->rt_pmtu = rt->rt_pmtu; 1689 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1690 new_rt->rt_gw_family = rt->rt_gw_family; 1691 if (rt->rt_gw_family == AF_INET) 1692 new_rt->rt_gw4 = rt->rt_gw4; 1693 else if (rt->rt_gw_family == AF_INET6) 1694 new_rt->rt_gw6 = rt->rt_gw6; 1695 1696 new_rt->dst.input = READ_ONCE(rt->dst.input); 1697 new_rt->dst.output = READ_ONCE(rt->dst.output); 1698 new_rt->dst.error = rt->dst.error; 1699 new_rt->dst.lastuse = jiffies; 1700 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1701 } 1702 return new_rt; 1703} 1704EXPORT_SYMBOL(rt_dst_clone); 1705 1706/* called in rcu_read_lock() section */ 1707enum skb_drop_reason 1708ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1709 dscp_t dscp, struct net_device *dev, 1710 struct in_device *in_dev, u32 *itag) 1711{ 1712 enum skb_drop_reason reason; 1713 1714 /* Primary sanity checks. */ 1715 if (!in_dev) 1716 return SKB_DROP_REASON_NOT_SPECIFIED; 1717 1718 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1719 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1720 1721 if (skb->protocol != htons(ETH_P_IP)) 1722 return SKB_DROP_REASON_INVALID_PROTO; 1723 1724 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1725 return SKB_DROP_REASON_IP_LOCALNET; 1726 1727 if (ipv4_is_zeronet(saddr)) { 1728 if (!ipv4_is_local_multicast(daddr) && 1729 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1730 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1731 } else { 1732 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1733 dev, in_dev, itag); 1734 if (reason) 1735 return reason; 1736 } 1737 return SKB_NOT_DROPPED_YET; 1738} 1739 1740/* called in rcu_read_lock() section */ 1741static enum skb_drop_reason 1742ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1743 dscp_t dscp, struct net_device *dev, int our) 1744{ 1745 struct in_device *in_dev = __in_dev_get_rcu(dev); 1746 unsigned int flags = RTCF_MULTICAST; 1747 enum skb_drop_reason reason; 1748 struct rtable *rth; 1749 u32 itag = 0; 1750 1751 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1752 &itag); 1753 if (reason) 1754 return reason; 1755 1756 if (our) 1757 flags |= RTCF_LOCAL; 1758 1759 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1760 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1761 1762 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1763 false); 1764 if (!rth) 1765 return SKB_DROP_REASON_NOMEM; 1766 1767#ifdef CONFIG_IP_ROUTE_CLASSID 1768 rth->dst.tclassid = itag; 1769#endif 1770 rth->dst.output = ip_rt_bug; 1771 rth->rt_is_input= 1; 1772 1773#ifdef CONFIG_IP_MROUTE 1774 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1775 rth->dst.input = ip_mr_input; 1776#endif 1777 RT_CACHE_STAT_INC(in_slow_mc); 1778 1779 skb_dst_drop(skb); 1780 skb_dst_set(skb, &rth->dst); 1781 return SKB_NOT_DROPPED_YET; 1782} 1783 1784 1785static void ip_handle_martian_source(struct net_device *dev, 1786 struct in_device *in_dev, 1787 struct sk_buff *skb, 1788 __be32 daddr, 1789 __be32 saddr) 1790{ 1791 RT_CACHE_STAT_INC(in_martian_src); 1792#ifdef CONFIG_IP_ROUTE_VERBOSE 1793 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1794 /* 1795 * RFC1812 recommendation, if source is martian, 1796 * the only hint is MAC header. 1797 */ 1798 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1799 &daddr, &saddr, dev->name); 1800 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1801 print_hex_dump(KERN_WARNING, "ll header: ", 1802 DUMP_PREFIX_OFFSET, 16, 1, 1803 skb_mac_header(skb), 1804 dev->hard_header_len, false); 1805 } 1806 } 1807#endif 1808} 1809 1810/* called in rcu_read_lock() section */ 1811static enum skb_drop_reason 1812__mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1813 struct in_device *in_dev, __be32 daddr, 1814 __be32 saddr, dscp_t dscp) 1815{ 1816 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1817 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1818 struct net_device *dev = nhc->nhc_dev; 1819 struct fib_nh_exception *fnhe; 1820 struct rtable *rth; 1821 int err; 1822 struct in_device *out_dev; 1823 bool do_cache; 1824 u32 itag = 0; 1825 1826 /* get a working reference to the output device */ 1827 out_dev = __in_dev_get_rcu(dev); 1828 if (!out_dev) { 1829 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1830 return reason; 1831 } 1832 1833 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1834 in_dev->dev, in_dev, &itag); 1835 if (err < 0) { 1836 reason = -err; 1837 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1838 saddr); 1839 1840 goto cleanup; 1841 } 1842 1843 do_cache = res->fi && !itag; 1844 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1845 skb->protocol == htons(ETH_P_IP)) { 1846 __be32 gw; 1847 1848 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1849 if (IN_DEV_SHARED_MEDIA(out_dev) || 1850 inet_addr_onlink(out_dev, saddr, gw)) 1851 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1852 } 1853 1854 if (skb->protocol != htons(ETH_P_IP)) { 1855 /* Not IP (i.e. ARP). Do not create route, if it is 1856 * invalid for proxy arp. DNAT routes are always valid. 1857 * 1858 * Proxy arp feature have been extended to allow, ARP 1859 * replies back to the same interface, to support 1860 * Private VLAN switch technologies. See arp.c. 1861 */ 1862 if (out_dev == in_dev && 1863 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1864 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1865 goto cleanup; 1866 } 1867 } 1868 1869 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1870 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1871 1872 fnhe = find_exception(nhc, daddr); 1873 if (do_cache) { 1874 if (fnhe) 1875 rth = rcu_dereference(fnhe->fnhe_rth_input); 1876 else 1877 rth = rcu_dereference(nhc->nhc_rth_input); 1878 if (rt_cache_valid(rth)) { 1879 skb_dst_set_noref(skb, &rth->dst); 1880 goto out; 1881 } 1882 } 1883 1884 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1885 IN_DEV_ORCONF(out_dev, NOXFRM)); 1886 if (!rth) { 1887 reason = SKB_DROP_REASON_NOMEM; 1888 goto cleanup; 1889 } 1890 1891 rth->rt_is_input = 1; 1892 RT_CACHE_STAT_INC(in_slow_tot); 1893 1894 rth->dst.input = ip_forward; 1895 1896 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1897 do_cache); 1898 lwtunnel_set_redirect(&rth->dst); 1899 skb_dst_set(skb, &rth->dst); 1900out: 1901 reason = SKB_NOT_DROPPED_YET; 1902cleanup: 1903 return reason; 1904} 1905 1906#ifdef CONFIG_IP_ROUTE_MULTIPATH 1907/* To make ICMP packets follow the right flow, the multipath hash is 1908 * calculated from the inner IP addresses. 1909 */ 1910static void ip_multipath_l3_keys(const struct sk_buff *skb, 1911 struct flow_keys *hash_keys) 1912{ 1913 const struct iphdr *outer_iph = ip_hdr(skb); 1914 const struct iphdr *key_iph = outer_iph; 1915 const struct iphdr *inner_iph; 1916 const struct icmphdr *icmph; 1917 struct iphdr _inner_iph; 1918 struct icmphdr _icmph; 1919 1920 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1921 goto out; 1922 1923 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1924 goto out; 1925 1926 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1927 &_icmph); 1928 if (!icmph) 1929 goto out; 1930 1931 if (!icmp_is_err(icmph->type)) 1932 goto out; 1933 1934 inner_iph = skb_header_pointer(skb, 1935 outer_iph->ihl * 4 + sizeof(_icmph), 1936 sizeof(_inner_iph), &_inner_iph); 1937 if (!inner_iph) 1938 goto out; 1939 1940 key_iph = inner_iph; 1941out: 1942 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1943 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1944} 1945 1946static u32 fib_multipath_custom_hash_outer(const struct net *net, 1947 const struct sk_buff *skb, 1948 bool *p_has_inner) 1949{ 1950 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1951 struct flow_keys keys, hash_keys; 1952 1953 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1954 return 0; 1955 1956 memset(&hash_keys, 0, sizeof(hash_keys)); 1957 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1958 1959 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1960 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1961 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1962 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1963 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1964 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1965 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1966 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1967 hash_keys.ports.src = keys.ports.src; 1968 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1969 hash_keys.ports.dst = keys.ports.dst; 1970 1971 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1972 return fib_multipath_hash_from_keys(net, &hash_keys); 1973} 1974 1975static u32 fib_multipath_custom_hash_inner(const struct net *net, 1976 const struct sk_buff *skb, 1977 bool has_inner) 1978{ 1979 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1980 struct flow_keys keys, hash_keys; 1981 1982 /* We assume the packet carries an encapsulation, but if none was 1983 * encountered during dissection of the outer flow, then there is no 1984 * point in calling the flow dissector again. 1985 */ 1986 if (!has_inner) 1987 return 0; 1988 1989 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1990 return 0; 1991 1992 memset(&hash_keys, 0, sizeof(hash_keys)); 1993 skb_flow_dissect_flow_keys(skb, &keys, 0); 1994 1995 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1996 return 0; 1997 1998 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1999 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2000 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2001 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2002 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2003 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2004 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2005 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2006 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2007 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2008 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2009 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2010 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2011 hash_keys.tags.flow_label = keys.tags.flow_label; 2012 } 2013 2014 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2015 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2016 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2017 hash_keys.ports.src = keys.ports.src; 2018 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2019 hash_keys.ports.dst = keys.ports.dst; 2020 2021 return fib_multipath_hash_from_keys(net, &hash_keys); 2022} 2023 2024static u32 fib_multipath_custom_hash_skb(const struct net *net, 2025 const struct sk_buff *skb) 2026{ 2027 u32 mhash, mhash_inner; 2028 bool has_inner = true; 2029 2030 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2031 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2032 2033 return jhash_2words(mhash, mhash_inner, 0); 2034} 2035 2036static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2037 const struct flowi4 *fl4) 2038{ 2039 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2040 struct flow_keys hash_keys; 2041 2042 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2043 return 0; 2044 2045 memset(&hash_keys, 0, sizeof(hash_keys)); 2046 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2047 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2048 hash_keys.addrs.v4addrs.src = fl4->saddr; 2049 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2050 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2051 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2052 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2053 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2054 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2055 hash_keys.ports.src = (__force __be16)get_random_u16(); 2056 else 2057 hash_keys.ports.src = fl4->fl4_sport; 2058 } 2059 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2060 hash_keys.ports.dst = fl4->fl4_dport; 2061 2062 return fib_multipath_hash_from_keys(net, &hash_keys); 2063} 2064 2065/* if skb is set it will be used and fl4 can be NULL */ 2066int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2067 const struct sk_buff *skb, struct flow_keys *flkeys) 2068{ 2069 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2070 struct flow_keys hash_keys; 2071 u32 mhash = 0; 2072 2073 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2074 case 0: 2075 memset(&hash_keys, 0, sizeof(hash_keys)); 2076 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2077 if (skb) { 2078 ip_multipath_l3_keys(skb, &hash_keys); 2079 } else { 2080 hash_keys.addrs.v4addrs.src = fl4->saddr; 2081 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2082 } 2083 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2084 break; 2085 case 1: 2086 /* skb is currently provided only when forwarding */ 2087 if (skb) { 2088 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2089 struct flow_keys keys; 2090 2091 /* short-circuit if we already have L4 hash present */ 2092 if (skb->l4_hash) 2093 return skb_get_hash_raw(skb) >> 1; 2094 2095 memset(&hash_keys, 0, sizeof(hash_keys)); 2096 2097 if (!flkeys) { 2098 skb_flow_dissect_flow_keys(skb, &keys, flag); 2099 flkeys = &keys; 2100 } 2101 2102 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2103 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2104 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2105 hash_keys.ports.src = flkeys->ports.src; 2106 hash_keys.ports.dst = flkeys->ports.dst; 2107 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2108 } else { 2109 memset(&hash_keys, 0, sizeof(hash_keys)); 2110 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2111 hash_keys.addrs.v4addrs.src = fl4->saddr; 2112 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2113 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2114 hash_keys.ports.src = (__force __be16)get_random_u16(); 2115 else 2116 hash_keys.ports.src = fl4->fl4_sport; 2117 hash_keys.ports.dst = fl4->fl4_dport; 2118 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2119 } 2120 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2121 break; 2122 case 2: 2123 memset(&hash_keys, 0, sizeof(hash_keys)); 2124 /* skb is currently provided only when forwarding */ 2125 if (skb) { 2126 struct flow_keys keys; 2127 2128 skb_flow_dissect_flow_keys(skb, &keys, 0); 2129 /* Inner can be v4 or v6 */ 2130 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2131 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2132 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2133 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2134 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2135 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2136 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2137 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2138 hash_keys.tags.flow_label = keys.tags.flow_label; 2139 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2140 } else { 2141 /* Same as case 0 */ 2142 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2143 ip_multipath_l3_keys(skb, &hash_keys); 2144 } 2145 } else { 2146 /* Same as case 0 */ 2147 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2148 hash_keys.addrs.v4addrs.src = fl4->saddr; 2149 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2150 } 2151 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2152 break; 2153 case 3: 2154 if (skb) 2155 mhash = fib_multipath_custom_hash_skb(net, skb); 2156 else 2157 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2158 break; 2159 } 2160 2161 if (multipath_hash) 2162 mhash = jhash_2words(mhash, multipath_hash, 0); 2163 2164 return mhash >> 1; 2165} 2166#endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2167 2168static enum skb_drop_reason 2169ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2170 struct in_device *in_dev, __be32 daddr, 2171 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2172{ 2173#ifdef CONFIG_IP_ROUTE_MULTIPATH 2174 if (res->fi && fib_info_num_path(res->fi) > 1) { 2175 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2176 2177 fib_select_multipath(res, h, NULL); 2178 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2179 } 2180#endif 2181 2182 /* create a routing cache entry */ 2183 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2184} 2185 2186/* Implements all the saddr-related checks as ip_route_input_slow(), 2187 * assuming daddr is valid and the destination is not a local broadcast one. 2188 * Uses the provided hint instead of performing a route lookup. 2189 */ 2190enum skb_drop_reason 2191ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2192 dscp_t dscp, struct net_device *dev, 2193 const struct sk_buff *hint) 2194{ 2195 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2196 struct in_device *in_dev = __in_dev_get_rcu(dev); 2197 struct rtable *rt = skb_rtable(hint); 2198 struct net *net = dev_net(dev); 2199 u32 tag = 0; 2200 2201 if (!in_dev) 2202 return reason; 2203 2204 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2205 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2206 goto martian_source; 2207 } 2208 2209 if (ipv4_is_zeronet(saddr)) { 2210 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2211 goto martian_source; 2212 } 2213 2214 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2215 reason = SKB_DROP_REASON_IP_LOCALNET; 2216 goto martian_source; 2217 } 2218 2219 if (!(rt->rt_flags & RTCF_LOCAL)) 2220 goto skip_validate_source; 2221 2222 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2223 in_dev, &tag); 2224 if (reason) 2225 goto martian_source; 2226 2227skip_validate_source: 2228 skb_dst_copy(skb, hint); 2229 return SKB_NOT_DROPPED_YET; 2230 2231martian_source: 2232 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2233 return reason; 2234} 2235 2236/* get device for dst_alloc with local routes */ 2237static struct net_device *ip_rt_get_dev(struct net *net, 2238 const struct fib_result *res) 2239{ 2240 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2241 struct net_device *dev = NULL; 2242 2243 if (nhc) 2244 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2245 2246 return dev ? : net->loopback_dev; 2247} 2248 2249/* 2250 * NOTE. We drop all the packets that has local source 2251 * addresses, because every properly looped back packet 2252 * must have correct destination already attached by output routine. 2253 * Changes in the enforced policies must be applied also to 2254 * ip_route_use_hint(). 2255 * 2256 * Such approach solves two big problems: 2257 * 1. Not simplex devices are handled properly. 2258 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2259 * called with rcu_read_lock() 2260 */ 2261 2262static enum skb_drop_reason 2263ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2264 dscp_t dscp, struct net_device *dev, 2265 struct fib_result *res) 2266{ 2267 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2268 struct in_device *in_dev = __in_dev_get_rcu(dev); 2269 struct flow_keys *flkeys = NULL, _flkeys; 2270 struct net *net = dev_net(dev); 2271 struct ip_tunnel_info *tun_info; 2272 int err = -EINVAL; 2273 unsigned int flags = 0; 2274 u32 itag = 0; 2275 struct rtable *rth; 2276 struct flowi4 fl4; 2277 bool do_cache = true; 2278 2279 /* IP on this device is disabled. */ 2280 2281 if (!in_dev) 2282 goto out; 2283 2284 /* Check for the most weird martians, which can be not detected 2285 * by fib_lookup. 2286 */ 2287 2288 tun_info = skb_tunnel_info(skb); 2289 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2290 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2291 else 2292 fl4.flowi4_tun_key.tun_id = 0; 2293 skb_dst_drop(skb); 2294 2295 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2296 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2297 goto martian_source; 2298 } 2299 2300 res->fi = NULL; 2301 res->table = NULL; 2302 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2303 goto brd_input; 2304 2305 /* Accept zero addresses only to limited broadcast; 2306 * I even do not know to fix it or not. Waiting for complains :-) 2307 */ 2308 if (ipv4_is_zeronet(saddr)) { 2309 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2310 goto martian_source; 2311 } 2312 2313 if (ipv4_is_zeronet(daddr)) { 2314 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2315 goto martian_destination; 2316 } 2317 2318 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2319 * and call it once if daddr or/and saddr are loopback addresses 2320 */ 2321 if (ipv4_is_loopback(daddr)) { 2322 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2323 reason = SKB_DROP_REASON_IP_LOCALNET; 2324 goto martian_destination; 2325 } 2326 } else if (ipv4_is_loopback(saddr)) { 2327 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2328 reason = SKB_DROP_REASON_IP_LOCALNET; 2329 goto martian_source; 2330 } 2331 } 2332 2333 /* 2334 * Now we are ready to route packet. 2335 */ 2336 fl4.flowi4_l3mdev = 0; 2337 fl4.flowi4_oif = 0; 2338 fl4.flowi4_iif = dev->ifindex; 2339 fl4.flowi4_mark = skb->mark; 2340 fl4.flowi4_dscp = dscp; 2341 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2342 fl4.flowi4_flags = 0; 2343 fl4.daddr = daddr; 2344 fl4.saddr = saddr; 2345 fl4.flowi4_uid = sock_net_uid(net, NULL); 2346 fl4.flowi4_multipath_hash = 0; 2347 2348 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2349 flkeys = &_flkeys; 2350 } else { 2351 fl4.flowi4_proto = 0; 2352 fl4.fl4_sport = 0; 2353 fl4.fl4_dport = 0; 2354 } 2355 2356 err = fib_lookup(net, &fl4, res, 0); 2357 if (err != 0) { 2358 if (!IN_DEV_FORWARD(in_dev)) 2359 err = -EHOSTUNREACH; 2360 goto no_route; 2361 } 2362 2363 if (res->type == RTN_BROADCAST) { 2364 if (IN_DEV_BFORWARD(in_dev)) 2365 goto make_route; 2366 /* not do cache if bc_forwarding is enabled */ 2367 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2368 do_cache = false; 2369 goto brd_input; 2370 } 2371 2372 err = -EINVAL; 2373 if (res->type == RTN_LOCAL) { 2374 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2375 0, dev, in_dev, &itag); 2376 if (reason) 2377 goto martian_source; 2378 goto local_input; 2379 } 2380 2381 if (!IN_DEV_FORWARD(in_dev)) { 2382 err = -EHOSTUNREACH; 2383 goto no_route; 2384 } 2385 if (res->type != RTN_UNICAST) { 2386 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2387 goto martian_destination; 2388 } 2389 2390make_route: 2391 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2392 flkeys); 2393 2394out: 2395 return reason; 2396 2397brd_input: 2398 if (skb->protocol != htons(ETH_P_IP)) { 2399 reason = SKB_DROP_REASON_INVALID_PROTO; 2400 goto out; 2401 } 2402 2403 if (!ipv4_is_zeronet(saddr)) { 2404 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2405 dev, in_dev, &itag); 2406 if (reason) 2407 goto martian_source; 2408 } 2409 flags |= RTCF_BROADCAST; 2410 res->type = RTN_BROADCAST; 2411 RT_CACHE_STAT_INC(in_brd); 2412 2413local_input: 2414 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2415 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2416 2417 do_cache &= res->fi && !itag; 2418 if (do_cache) { 2419 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2420 2421 rth = rcu_dereference(nhc->nhc_rth_input); 2422 if (rt_cache_valid(rth)) { 2423 skb_dst_set_noref(skb, &rth->dst); 2424 reason = SKB_NOT_DROPPED_YET; 2425 goto out; 2426 } 2427 } 2428 2429 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2430 flags | RTCF_LOCAL, res->type, false); 2431 if (!rth) 2432 goto e_nobufs; 2433 2434 rth->dst.output= ip_rt_bug; 2435#ifdef CONFIG_IP_ROUTE_CLASSID 2436 rth->dst.tclassid = itag; 2437#endif 2438 rth->rt_is_input = 1; 2439 2440 RT_CACHE_STAT_INC(in_slow_tot); 2441 if (res->type == RTN_UNREACHABLE) { 2442 rth->dst.input= ip_error; 2443 rth->dst.error= -err; 2444 rth->rt_flags &= ~RTCF_LOCAL; 2445 } 2446 2447 if (do_cache) { 2448 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2449 2450 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2451 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2452 WARN_ON(rth->dst.input == lwtunnel_input); 2453 rth->dst.lwtstate->orig_input = rth->dst.input; 2454 rth->dst.input = lwtunnel_input; 2455 } 2456 2457 if (unlikely(!rt_cache_route(nhc, rth))) 2458 rt_add_uncached_list(rth); 2459 } 2460 skb_dst_set(skb, &rth->dst); 2461 reason = SKB_NOT_DROPPED_YET; 2462 goto out; 2463 2464no_route: 2465 RT_CACHE_STAT_INC(in_no_route); 2466 res->type = RTN_UNREACHABLE; 2467 res->fi = NULL; 2468 res->table = NULL; 2469 goto local_input; 2470 2471 /* 2472 * Do not cache martian addresses: they should be logged (RFC1812) 2473 */ 2474martian_destination: 2475 RT_CACHE_STAT_INC(in_martian_dst); 2476#ifdef CONFIG_IP_ROUTE_VERBOSE 2477 if (IN_DEV_LOG_MARTIANS(in_dev)) 2478 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2479 &daddr, &saddr, dev->name); 2480#endif 2481 goto out; 2482 2483e_nobufs: 2484 reason = SKB_DROP_REASON_NOMEM; 2485 goto out; 2486 2487martian_source: 2488 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2489 goto out; 2490} 2491 2492/* called with rcu_read_lock held */ 2493static enum skb_drop_reason 2494ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2495 dscp_t dscp, struct net_device *dev, 2496 struct fib_result *res) 2497{ 2498 /* Multicast recognition logic is moved from route cache to here. 2499 * The problem was that too many Ethernet cards have broken/missing 2500 * hardware multicast filters :-( As result the host on multicasting 2501 * network acquires a lot of useless route cache entries, sort of 2502 * SDR messages from all the world. Now we try to get rid of them. 2503 * Really, provided software IP multicast filter is organized 2504 * reasonably (at least, hashed), it does not result in a slowdown 2505 * comparing with route cache reject entries. 2506 * Note, that multicast routers are not affected, because 2507 * route cache entry is created eventually. 2508 */ 2509 if (ipv4_is_multicast(daddr)) { 2510 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2511 struct in_device *in_dev = __in_dev_get_rcu(dev); 2512 int our = 0; 2513 2514 if (!in_dev) 2515 return reason; 2516 2517 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2518 ip_hdr(skb)->protocol); 2519 2520 /* check l3 master if no match yet */ 2521 if (!our && netif_is_l3_slave(dev)) { 2522 struct in_device *l3_in_dev; 2523 2524 l3_in_dev = __in_dev_get_rcu(skb->dev); 2525 if (l3_in_dev) 2526 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2527 ip_hdr(skb)->protocol); 2528 } 2529 2530 if (our 2531#ifdef CONFIG_IP_MROUTE 2532 || 2533 (!ipv4_is_local_multicast(daddr) && 2534 IN_DEV_MFORWARD(in_dev)) 2535#endif 2536 ) { 2537 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2538 dev, our); 2539 } 2540 return reason; 2541 } 2542 2543 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2544} 2545 2546enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2547 __be32 saddr, dscp_t dscp, 2548 struct net_device *dev) 2549{ 2550 enum skb_drop_reason reason; 2551 struct fib_result res; 2552 2553 rcu_read_lock(); 2554 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2555 rcu_read_unlock(); 2556 2557 return reason; 2558} 2559EXPORT_SYMBOL(ip_route_input_noref); 2560 2561/* called with rcu_read_lock() */ 2562static struct rtable *__mkroute_output(const struct fib_result *res, 2563 const struct flowi4 *fl4, int orig_oif, 2564 struct net_device *dev_out, 2565 unsigned int flags) 2566{ 2567 struct fib_info *fi = res->fi; 2568 struct fib_nh_exception *fnhe; 2569 struct in_device *in_dev; 2570 u16 type = res->type; 2571 struct rtable *rth; 2572 bool do_cache; 2573 2574 in_dev = __in_dev_get_rcu(dev_out); 2575 if (!in_dev) 2576 return ERR_PTR(-EINVAL); 2577 2578 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2579 if (ipv4_is_loopback(fl4->saddr) && 2580 !(dev_out->flags & IFF_LOOPBACK) && 2581 !netif_is_l3_master(dev_out)) 2582 return ERR_PTR(-EINVAL); 2583 2584 if (ipv4_is_lbcast(fl4->daddr)) { 2585 type = RTN_BROADCAST; 2586 2587 /* reset fi to prevent gateway resolution */ 2588 fi = NULL; 2589 } else if (ipv4_is_multicast(fl4->daddr)) { 2590 type = RTN_MULTICAST; 2591 } else if (ipv4_is_zeronet(fl4->daddr)) { 2592 return ERR_PTR(-EINVAL); 2593 } 2594 2595 if (dev_out->flags & IFF_LOOPBACK) 2596 flags |= RTCF_LOCAL; 2597 2598 do_cache = true; 2599 if (type == RTN_BROADCAST) { 2600 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2601 } else if (type == RTN_MULTICAST) { 2602 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2603 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2604 fl4->flowi4_proto)) 2605 flags &= ~RTCF_LOCAL; 2606 else 2607 do_cache = false; 2608 /* If multicast route do not exist use 2609 * default one, but do not gateway in this case. 2610 * Yes, it is hack. 2611 */ 2612 if (fi && res->prefixlen < 4) 2613 fi = NULL; 2614 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2615 (orig_oif != dev_out->ifindex)) { 2616 /* For local routes that require a particular output interface 2617 * we do not want to cache the result. Caching the result 2618 * causes incorrect behaviour when there are multiple source 2619 * addresses on the interface, the end result being that if the 2620 * intended recipient is waiting on that interface for the 2621 * packet he won't receive it because it will be delivered on 2622 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2623 * be set to the loopback interface as well. 2624 */ 2625 do_cache = false; 2626 } 2627 2628 fnhe = NULL; 2629 do_cache &= fi != NULL; 2630 if (fi) { 2631 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2632 struct rtable __rcu **prth; 2633 2634 fnhe = find_exception(nhc, fl4->daddr); 2635 if (!do_cache) 2636 goto add; 2637 if (fnhe) { 2638 prth = &fnhe->fnhe_rth_output; 2639 } else { 2640 if (unlikely(fl4->flowi4_flags & 2641 FLOWI_FLAG_KNOWN_NH && 2642 !(nhc->nhc_gw_family && 2643 nhc->nhc_scope == RT_SCOPE_LINK))) { 2644 do_cache = false; 2645 goto add; 2646 } 2647 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2648 } 2649 rth = rcu_dereference(*prth); 2650 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2651 return rth; 2652 } 2653 2654add: 2655 rth = rt_dst_alloc(dev_out, flags, type, 2656 IN_DEV_ORCONF(in_dev, NOXFRM)); 2657 if (!rth) 2658 return ERR_PTR(-ENOBUFS); 2659 2660 rth->rt_iif = orig_oif; 2661 2662 RT_CACHE_STAT_INC(out_slow_tot); 2663 2664 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2665 if (flags & RTCF_LOCAL && 2666 !(dev_out->flags & IFF_LOOPBACK)) { 2667 rth->dst.output = ip_mc_output; 2668 RT_CACHE_STAT_INC(out_slow_mc); 2669 } 2670#ifdef CONFIG_IP_MROUTE 2671 if (type == RTN_MULTICAST) { 2672 if (IN_DEV_MFORWARD(in_dev) && 2673 !ipv4_is_local_multicast(fl4->daddr)) { 2674 rth->dst.input = ip_mr_input; 2675 rth->dst.output = ip_mr_output; 2676 } 2677 } 2678#endif 2679 } 2680 2681 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2682 lwtunnel_set_redirect(&rth->dst); 2683 2684 return rth; 2685} 2686 2687/* 2688 * Major route resolver routine. 2689 */ 2690 2691struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2692 const struct sk_buff *skb) 2693{ 2694 struct fib_result res = { 2695 .type = RTN_UNSPEC, 2696 .fi = NULL, 2697 .table = NULL, 2698 .tclassid = 0, 2699 }; 2700 struct rtable *rth; 2701 2702 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2703 2704 rcu_read_lock(); 2705 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2706 rcu_read_unlock(); 2707 2708 return rth; 2709} 2710EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2711 2712struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2713 struct fib_result *res, 2714 const struct sk_buff *skb) 2715{ 2716 struct net_device *dev_out = NULL; 2717 int orig_oif = fl4->flowi4_oif; 2718 unsigned int flags = 0; 2719 struct rtable *rth; 2720 int err; 2721 2722 if (fl4->saddr) { 2723 if (ipv4_is_multicast(fl4->saddr) || 2724 ipv4_is_lbcast(fl4->saddr)) { 2725 rth = ERR_PTR(-EINVAL); 2726 goto out; 2727 } 2728 2729 rth = ERR_PTR(-ENETUNREACH); 2730 2731 /* I removed check for oif == dev_out->oif here. 2732 * It was wrong for two reasons: 2733 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2734 * is assigned to multiple interfaces. 2735 * 2. Moreover, we are allowed to send packets with saddr 2736 * of another iface. --ANK 2737 */ 2738 2739 if (fl4->flowi4_oif == 0 && 2740 (ipv4_is_multicast(fl4->daddr) || 2741 ipv4_is_lbcast(fl4->daddr))) { 2742 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2743 dev_out = __ip_dev_find(net, fl4->saddr, false); 2744 if (!dev_out) 2745 goto out; 2746 2747 /* Special hack: user can direct multicasts 2748 * and limited broadcast via necessary interface 2749 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2750 * This hack is not just for fun, it allows 2751 * vic,vat and friends to work. 2752 * They bind socket to loopback, set ttl to zero 2753 * and expect that it will work. 2754 * From the viewpoint of routing cache they are broken, 2755 * because we are not allowed to build multicast path 2756 * with loopback source addr (look, routing cache 2757 * cannot know, that ttl is zero, so that packet 2758 * will not leave this host and route is valid). 2759 * Luckily, this hack is good workaround. 2760 */ 2761 2762 fl4->flowi4_oif = dev_out->ifindex; 2763 goto make_route; 2764 } 2765 2766 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2767 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2768 if (!__ip_dev_find(net, fl4->saddr, false)) 2769 goto out; 2770 } 2771 } 2772 2773 2774 if (fl4->flowi4_oif) { 2775 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2776 rth = ERR_PTR(-ENODEV); 2777 if (!dev_out) 2778 goto out; 2779 2780 /* RACE: Check return value of inet_select_addr instead. */ 2781 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2782 rth = ERR_PTR(-ENETUNREACH); 2783 goto out; 2784 } 2785 if (ipv4_is_local_multicast(fl4->daddr) || 2786 ipv4_is_lbcast(fl4->daddr) || 2787 fl4->flowi4_proto == IPPROTO_IGMP) { 2788 if (!fl4->saddr) 2789 fl4->saddr = inet_select_addr(dev_out, 0, 2790 RT_SCOPE_LINK); 2791 goto make_route; 2792 } 2793 if (!fl4->saddr) { 2794 if (ipv4_is_multicast(fl4->daddr)) 2795 fl4->saddr = inet_select_addr(dev_out, 0, 2796 fl4->flowi4_scope); 2797 else if (!fl4->daddr) 2798 fl4->saddr = inet_select_addr(dev_out, 0, 2799 RT_SCOPE_HOST); 2800 } 2801 } 2802 2803 if (!fl4->daddr) { 2804 fl4->daddr = fl4->saddr; 2805 if (!fl4->daddr) 2806 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2807 dev_out = net->loopback_dev; 2808 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2809 res->type = RTN_LOCAL; 2810 flags |= RTCF_LOCAL; 2811 goto make_route; 2812 } 2813 2814 err = fib_lookup(net, fl4, res, 0); 2815 if (err) { 2816 res->fi = NULL; 2817 res->table = NULL; 2818 if (fl4->flowi4_oif && 2819 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2820 /* Apparently, routing tables are wrong. Assume, 2821 * that the destination is on link. 2822 * 2823 * WHY? DW. 2824 * Because we are allowed to send to iface 2825 * even if it has NO routes and NO assigned 2826 * addresses. When oif is specified, routing 2827 * tables are looked up with only one purpose: 2828 * to catch if destination is gatewayed, rather than 2829 * direct. Moreover, if MSG_DONTROUTE is set, 2830 * we send packet, ignoring both routing tables 2831 * and ifaddr state. --ANK 2832 * 2833 * 2834 * We could make it even if oif is unknown, 2835 * likely IPv6, but we do not. 2836 */ 2837 2838 if (fl4->saddr == 0) 2839 fl4->saddr = inet_select_addr(dev_out, 0, 2840 RT_SCOPE_LINK); 2841 res->type = RTN_UNICAST; 2842 goto make_route; 2843 } 2844 rth = ERR_PTR(err); 2845 goto out; 2846 } 2847 2848 if (res->type == RTN_LOCAL) { 2849 if (!fl4->saddr) { 2850 if (res->fi->fib_prefsrc) 2851 fl4->saddr = res->fi->fib_prefsrc; 2852 else 2853 fl4->saddr = fl4->daddr; 2854 } 2855 2856 /* L3 master device is the loopback for that domain */ 2857 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2858 net->loopback_dev; 2859 2860 /* make sure orig_oif points to fib result device even 2861 * though packet rx/tx happens over loopback or l3mdev 2862 */ 2863 orig_oif = FIB_RES_OIF(*res); 2864 2865 fl4->flowi4_oif = dev_out->ifindex; 2866 flags |= RTCF_LOCAL; 2867 goto make_route; 2868 } 2869 2870 fib_select_path(net, res, fl4, skb); 2871 2872 dev_out = FIB_RES_DEV(*res); 2873 2874make_route: 2875 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2876 2877out: 2878 return rth; 2879} 2880 2881static struct dst_ops ipv4_dst_blackhole_ops = { 2882 .family = AF_INET, 2883 .default_advmss = ipv4_default_advmss, 2884 .neigh_lookup = ipv4_neigh_lookup, 2885 .check = dst_blackhole_check, 2886 .cow_metrics = dst_blackhole_cow_metrics, 2887 .update_pmtu = dst_blackhole_update_pmtu, 2888 .redirect = dst_blackhole_redirect, 2889 .mtu = dst_blackhole_mtu, 2890}; 2891 2892struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2893{ 2894 struct rtable *ort = dst_rtable(dst_orig); 2895 struct rtable *rt; 2896 2897 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2898 if (rt) { 2899 struct dst_entry *new = &rt->dst; 2900 2901 new->__use = 1; 2902 new->input = dst_discard; 2903 new->output = dst_discard_out; 2904 2905 new->dev = net->loopback_dev; 2906 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2907 2908 rt->rt_is_input = ort->rt_is_input; 2909 rt->rt_iif = ort->rt_iif; 2910 rt->rt_pmtu = ort->rt_pmtu; 2911 rt->rt_mtu_locked = ort->rt_mtu_locked; 2912 2913 rt->rt_genid = rt_genid_ipv4(net); 2914 rt->rt_flags = ort->rt_flags; 2915 rt->rt_type = ort->rt_type; 2916 rt->rt_uses_gateway = ort->rt_uses_gateway; 2917 rt->rt_gw_family = ort->rt_gw_family; 2918 if (rt->rt_gw_family == AF_INET) 2919 rt->rt_gw4 = ort->rt_gw4; 2920 else if (rt->rt_gw_family == AF_INET6) 2921 rt->rt_gw6 = ort->rt_gw6; 2922 } 2923 2924 dst_release(dst_orig); 2925 2926 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2927} 2928 2929struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2930 const struct sock *sk) 2931{ 2932 struct rtable *rt = __ip_route_output_key(net, flp4); 2933 2934 if (IS_ERR(rt)) 2935 return rt; 2936 2937 if (flp4->flowi4_proto) { 2938 flp4->flowi4_oif = rt->dst.dev->ifindex; 2939 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2940 flowi4_to_flowi(flp4), 2941 sk, 0)); 2942 } 2943 2944 return rt; 2945} 2946EXPORT_SYMBOL_GPL(ip_route_output_flow); 2947 2948/* called with rcu_read_lock held */ 2949static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2950 struct rtable *rt, u32 table_id, dscp_t dscp, 2951 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2952 u32 seq, unsigned int flags) 2953{ 2954 struct rtmsg *r; 2955 struct nlmsghdr *nlh; 2956 unsigned long expires = 0; 2957 u32 error; 2958 u32 metrics[RTAX_MAX]; 2959 2960 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2961 if (!nlh) 2962 return -EMSGSIZE; 2963 2964 r = nlmsg_data(nlh); 2965 r->rtm_family = AF_INET; 2966 r->rtm_dst_len = 32; 2967 r->rtm_src_len = 0; 2968 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2969 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2970 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2971 goto nla_put_failure; 2972 r->rtm_type = rt->rt_type; 2973 r->rtm_scope = RT_SCOPE_UNIVERSE; 2974 r->rtm_protocol = RTPROT_UNSPEC; 2975 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2976 if (rt->rt_flags & RTCF_NOTIFY) 2977 r->rtm_flags |= RTM_F_NOTIFY; 2978 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2979 r->rtm_flags |= RTCF_DOREDIRECT; 2980 2981 if (nla_put_in_addr(skb, RTA_DST, dst)) 2982 goto nla_put_failure; 2983 if (src) { 2984 r->rtm_src_len = 32; 2985 if (nla_put_in_addr(skb, RTA_SRC, src)) 2986 goto nla_put_failure; 2987 } 2988 if (rt->dst.dev && 2989 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2990 goto nla_put_failure; 2991 if (lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2992 goto nla_put_failure; 2993#ifdef CONFIG_IP_ROUTE_CLASSID 2994 if (rt->dst.tclassid && 2995 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2996 goto nla_put_failure; 2997#endif 2998 if (fl4 && !rt_is_input_route(rt) && 2999 fl4->saddr != src) { 3000 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 3001 goto nla_put_failure; 3002 } 3003 if (rt->rt_uses_gateway) { 3004 if (rt->rt_gw_family == AF_INET && 3005 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 3006 goto nla_put_failure; 3007 } else if (rt->rt_gw_family == AF_INET6) { 3008 int alen = sizeof(struct in6_addr); 3009 struct nlattr *nla; 3010 struct rtvia *via; 3011 3012 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3013 if (!nla) 3014 goto nla_put_failure; 3015 3016 via = nla_data(nla); 3017 via->rtvia_family = AF_INET6; 3018 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3019 } 3020 } 3021 3022 expires = READ_ONCE(rt->dst.expires); 3023 if (expires) { 3024 unsigned long now = jiffies; 3025 3026 if (time_before(now, expires)) 3027 expires -= now; 3028 else 3029 expires = 0; 3030 } 3031 3032 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3033 if (rt->rt_pmtu && expires) 3034 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3035 if (rt->rt_mtu_locked && expires) 3036 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3037 if (rtnetlink_put_metrics(skb, metrics) < 0) 3038 goto nla_put_failure; 3039 3040 if (fl4) { 3041 if (fl4->flowi4_mark && 3042 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3043 goto nla_put_failure; 3044 3045 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3046 nla_put_u32(skb, RTA_UID, 3047 from_kuid_munged(current_user_ns(), 3048 fl4->flowi4_uid))) 3049 goto nla_put_failure; 3050 3051 if (rt_is_input_route(rt)) { 3052#ifdef CONFIG_IP_MROUTE 3053 if (ipv4_is_multicast(dst) && 3054 !ipv4_is_local_multicast(dst) && 3055 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3056 int err = ipmr_get_route(net, skb, 3057 fl4->saddr, fl4->daddr, 3058 r, portid); 3059 3060 if (err <= 0) { 3061 if (err == 0) 3062 return 0; 3063 goto nla_put_failure; 3064 } 3065 } else 3066#endif 3067 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3068 goto nla_put_failure; 3069 } 3070 } 3071 3072 error = rt->dst.error; 3073 3074 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3075 goto nla_put_failure; 3076 3077 nlmsg_end(skb, nlh); 3078 return 0; 3079 3080nla_put_failure: 3081 nlmsg_cancel(skb, nlh); 3082 return -EMSGSIZE; 3083} 3084 3085static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3086 struct netlink_callback *cb, u32 table_id, 3087 struct fnhe_hash_bucket *bucket, int genid, 3088 int *fa_index, int fa_start, unsigned int flags) 3089{ 3090 int i; 3091 3092 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3093 struct fib_nh_exception *fnhe; 3094 3095 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3096 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3097 struct rtable *rt; 3098 int err; 3099 3100 if (*fa_index < fa_start) 3101 goto next; 3102 3103 if (fnhe->fnhe_genid != genid) 3104 goto next; 3105 3106 if (fnhe->fnhe_expires && 3107 time_after(jiffies, fnhe->fnhe_expires)) 3108 goto next; 3109 3110 rt = rcu_dereference(fnhe->fnhe_rth_input); 3111 if (!rt) 3112 rt = rcu_dereference(fnhe->fnhe_rth_output); 3113 if (!rt) 3114 goto next; 3115 3116 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3117 table_id, 0, NULL, skb, 3118 NETLINK_CB(cb->skb).portid, 3119 cb->nlh->nlmsg_seq, flags); 3120 if (err) 3121 return err; 3122next: 3123 (*fa_index)++; 3124 } 3125 } 3126 3127 return 0; 3128} 3129 3130int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3131 u32 table_id, struct fib_info *fi, 3132 int *fa_index, int fa_start, unsigned int flags) 3133{ 3134 struct net *net = sock_net(cb->skb->sk); 3135 int nhsel, genid = fnhe_genid(net); 3136 3137 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3138 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3139 struct fnhe_hash_bucket *bucket; 3140 int err; 3141 3142 if (nhc->nhc_flags & RTNH_F_DEAD) 3143 continue; 3144 3145 rcu_read_lock(); 3146 bucket = rcu_dereference(nhc->nhc_exceptions); 3147 err = 0; 3148 if (bucket) 3149 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3150 genid, fa_index, fa_start, 3151 flags); 3152 rcu_read_unlock(); 3153 if (err) 3154 return err; 3155 } 3156 3157 return 0; 3158} 3159 3160static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3161 u8 ip_proto, __be16 sport, 3162 __be16 dport) 3163{ 3164 struct sk_buff *skb; 3165 struct iphdr *iph; 3166 3167 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3168 if (!skb) 3169 return NULL; 3170 3171 /* Reserve room for dummy headers, this skb can pass 3172 * through good chunk of routing engine. 3173 */ 3174 skb_reset_mac_header(skb); 3175 skb_reset_network_header(skb); 3176 skb->protocol = htons(ETH_P_IP); 3177 iph = skb_put(skb, sizeof(struct iphdr)); 3178 iph->protocol = ip_proto; 3179 iph->saddr = src; 3180 iph->daddr = dst; 3181 iph->version = 0x4; 3182 iph->frag_off = 0; 3183 iph->ihl = 0x5; 3184 skb_set_transport_header(skb, skb->len); 3185 3186 switch (iph->protocol) { 3187 case IPPROTO_UDP: { 3188 struct udphdr *udph; 3189 3190 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3191 udph->source = sport; 3192 udph->dest = dport; 3193 udph->len = htons(sizeof(struct udphdr)); 3194 udph->check = 0; 3195 break; 3196 } 3197 case IPPROTO_TCP: { 3198 struct tcphdr *tcph; 3199 3200 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3201 tcph->source = sport; 3202 tcph->dest = dport; 3203 tcph->doff = sizeof(struct tcphdr) / 4; 3204 tcph->rst = 1; 3205 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3206 src, dst, 0); 3207 break; 3208 } 3209 case IPPROTO_ICMP: { 3210 struct icmphdr *icmph; 3211 3212 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3213 icmph->type = ICMP_ECHO; 3214 icmph->code = 0; 3215 } 3216 } 3217 3218 return skb; 3219} 3220 3221static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3222 const struct nlmsghdr *nlh, 3223 struct nlattr **tb, 3224 struct netlink_ext_ack *extack) 3225{ 3226 struct rtmsg *rtm; 3227 int i, err; 3228 3229 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3230 if (!rtm) { 3231 NL_SET_ERR_MSG(extack, 3232 "ipv4: Invalid header for route get request"); 3233 return -EINVAL; 3234 } 3235 3236 if (!netlink_strict_get_check(skb)) 3237 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3238 rtm_ipv4_policy, extack); 3239 3240 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3241 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3242 rtm->rtm_table || rtm->rtm_protocol || 3243 rtm->rtm_scope || rtm->rtm_type) { 3244 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3245 return -EINVAL; 3246 } 3247 3248 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3249 RTM_F_LOOKUP_TABLE | 3250 RTM_F_FIB_MATCH)) { 3251 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3252 return -EINVAL; 3253 } 3254 3255 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3256 rtm_ipv4_policy, extack); 3257 if (err) 3258 return err; 3259 3260 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3261 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3262 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3263 return -EINVAL; 3264 } 3265 3266 for (i = 0; i <= RTA_MAX; i++) { 3267 if (!tb[i]) 3268 continue; 3269 3270 switch (i) { 3271 case RTA_IIF: 3272 case RTA_OIF: 3273 case RTA_SRC: 3274 case RTA_DST: 3275 case RTA_IP_PROTO: 3276 case RTA_SPORT: 3277 case RTA_DPORT: 3278 case RTA_MARK: 3279 case RTA_UID: 3280 break; 3281 default: 3282 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3283 return -EINVAL; 3284 } 3285 } 3286 3287 return 0; 3288} 3289 3290static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3291 struct netlink_ext_ack *extack) 3292{ 3293 struct net *net = sock_net(in_skb->sk); 3294 struct nlattr *tb[RTA_MAX+1]; 3295 u32 table_id = RT_TABLE_MAIN; 3296 __be16 sport = 0, dport = 0; 3297 struct fib_result res = {}; 3298 u8 ip_proto = IPPROTO_UDP; 3299 struct rtable *rt = NULL; 3300 struct sk_buff *skb; 3301 struct rtmsg *rtm; 3302 struct flowi4 fl4 = {}; 3303 __be32 dst = 0; 3304 __be32 src = 0; 3305 dscp_t dscp; 3306 kuid_t uid; 3307 u32 iif; 3308 int err; 3309 int mark; 3310 3311 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3312 if (err < 0) 3313 return err; 3314 3315 rtm = nlmsg_data(nlh); 3316 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3317 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3318 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3319 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3320 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3321 if (tb[RTA_UID]) 3322 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3323 else 3324 uid = (iif ? INVALID_UID : current_uid()); 3325 3326 if (tb[RTA_IP_PROTO]) { 3327 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3328 &ip_proto, AF_INET, extack); 3329 if (err) 3330 return err; 3331 } 3332 3333 if (tb[RTA_SPORT]) 3334 sport = nla_get_be16(tb[RTA_SPORT]); 3335 3336 if (tb[RTA_DPORT]) 3337 dport = nla_get_be16(tb[RTA_DPORT]); 3338 3339 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3340 if (!skb) 3341 return -ENOBUFS; 3342 3343 fl4.daddr = dst; 3344 fl4.saddr = src; 3345 fl4.flowi4_dscp = dscp; 3346 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3347 fl4.flowi4_mark = mark; 3348 fl4.flowi4_uid = uid; 3349 if (sport) 3350 fl4.fl4_sport = sport; 3351 if (dport) 3352 fl4.fl4_dport = dport; 3353 fl4.flowi4_proto = ip_proto; 3354 3355 rcu_read_lock(); 3356 3357 if (iif) { 3358 struct net_device *dev; 3359 3360 dev = dev_get_by_index_rcu(net, iif); 3361 if (!dev) { 3362 err = -ENODEV; 3363 goto errout_rcu; 3364 } 3365 3366 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3367 skb->dev = dev; 3368 skb->mark = mark; 3369 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3370 &res) ? -EINVAL : 0; 3371 3372 rt = skb_rtable(skb); 3373 if (err == 0 && rt->dst.error) 3374 err = -rt->dst.error; 3375 } else { 3376 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3377 skb->dev = net->loopback_dev; 3378 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3379 err = 0; 3380 if (IS_ERR(rt)) 3381 err = PTR_ERR(rt); 3382 else 3383 skb_dst_set(skb, &rt->dst); 3384 } 3385 3386 if (err) 3387 goto errout_rcu; 3388 3389 if (rtm->rtm_flags & RTM_F_NOTIFY) 3390 rt->rt_flags |= RTCF_NOTIFY; 3391 3392 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3393 table_id = res.table ? res.table->tb_id : 0; 3394 3395 /* reset skb for netlink reply msg */ 3396 skb_trim(skb, 0); 3397 skb_reset_network_header(skb); 3398 skb_reset_transport_header(skb); 3399 skb_reset_mac_header(skb); 3400 3401 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3402 struct fib_rt_info fri; 3403 3404 if (!res.fi) { 3405 err = fib_props[res.type].error; 3406 if (!err) 3407 err = -EHOSTUNREACH; 3408 goto errout_rcu; 3409 } 3410 fri.fi = res.fi; 3411 fri.tb_id = table_id; 3412 fri.dst = res.prefix; 3413 fri.dst_len = res.prefixlen; 3414 fri.dscp = res.dscp; 3415 fri.type = rt->rt_type; 3416 fri.offload = 0; 3417 fri.trap = 0; 3418 fri.offload_failed = 0; 3419 if (res.fa_head) { 3420 struct fib_alias *fa; 3421 3422 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3423 u8 slen = 32 - fri.dst_len; 3424 3425 if (fa->fa_slen == slen && 3426 fa->tb_id == fri.tb_id && 3427 fa->fa_dscp == fri.dscp && 3428 fa->fa_info == res.fi && 3429 fa->fa_type == fri.type) { 3430 fri.offload = READ_ONCE(fa->offload); 3431 fri.trap = READ_ONCE(fa->trap); 3432 fri.offload_failed = 3433 READ_ONCE(fa->offload_failed); 3434 break; 3435 } 3436 } 3437 } 3438 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3439 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3440 } else { 3441 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3442 skb, NETLINK_CB(in_skb).portid, 3443 nlh->nlmsg_seq, 0); 3444 } 3445 if (err < 0) 3446 goto errout_rcu; 3447 3448 rcu_read_unlock(); 3449 3450 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3451 3452errout_free: 3453 return err; 3454errout_rcu: 3455 rcu_read_unlock(); 3456 kfree_skb(skb); 3457 goto errout_free; 3458} 3459 3460void ip_rt_multicast_event(struct in_device *in_dev) 3461{ 3462 rt_cache_flush(dev_net(in_dev->dev)); 3463} 3464 3465#ifdef CONFIG_SYSCTL 3466static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3467static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3468static int ip_rt_gc_elasticity __read_mostly = 8; 3469static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3470 3471static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3472 void *buffer, size_t *lenp, loff_t *ppos) 3473{ 3474 struct net *net = (struct net *)__ctl->extra1; 3475 3476 if (write) { 3477 rt_cache_flush(net); 3478 fnhe_genid_bump(net); 3479 return 0; 3480 } 3481 3482 return -EINVAL; 3483} 3484 3485static struct ctl_table ipv4_route_table[] = { 3486 { 3487 .procname = "gc_thresh", 3488 .data = &ipv4_dst_ops.gc_thresh, 3489 .maxlen = sizeof(int), 3490 .mode = 0644, 3491 .proc_handler = proc_dointvec, 3492 }, 3493 { 3494 .procname = "max_size", 3495 .data = &ip_rt_max_size, 3496 .maxlen = sizeof(int), 3497 .mode = 0644, 3498 .proc_handler = proc_dointvec, 3499 }, 3500 { 3501 /* Deprecated. Use gc_min_interval_ms */ 3502 3503 .procname = "gc_min_interval", 3504 .data = &ip_rt_gc_min_interval, 3505 .maxlen = sizeof(int), 3506 .mode = 0644, 3507 .proc_handler = proc_dointvec_jiffies, 3508 }, 3509 { 3510 .procname = "gc_min_interval_ms", 3511 .data = &ip_rt_gc_min_interval, 3512 .maxlen = sizeof(int), 3513 .mode = 0644, 3514 .proc_handler = proc_dointvec_ms_jiffies, 3515 }, 3516 { 3517 .procname = "gc_timeout", 3518 .data = &ip_rt_gc_timeout, 3519 .maxlen = sizeof(int), 3520 .mode = 0644, 3521 .proc_handler = proc_dointvec_jiffies, 3522 }, 3523 { 3524 .procname = "gc_interval", 3525 .data = &ip_rt_gc_interval, 3526 .maxlen = sizeof(int), 3527 .mode = 0644, 3528 .proc_handler = proc_dointvec_jiffies, 3529 }, 3530 { 3531 .procname = "redirect_load", 3532 .data = &ip_rt_redirect_load, 3533 .maxlen = sizeof(int), 3534 .mode = 0644, 3535 .proc_handler = proc_dointvec, 3536 }, 3537 { 3538 .procname = "redirect_number", 3539 .data = &ip_rt_redirect_number, 3540 .maxlen = sizeof(int), 3541 .mode = 0644, 3542 .proc_handler = proc_dointvec, 3543 }, 3544 { 3545 .procname = "redirect_silence", 3546 .data = &ip_rt_redirect_silence, 3547 .maxlen = sizeof(int), 3548 .mode = 0644, 3549 .proc_handler = proc_dointvec, 3550 }, 3551 { 3552 .procname = "error_cost", 3553 .data = &ip_rt_error_cost, 3554 .maxlen = sizeof(int), 3555 .mode = 0644, 3556 .proc_handler = proc_dointvec, 3557 }, 3558 { 3559 .procname = "error_burst", 3560 .data = &ip_rt_error_burst, 3561 .maxlen = sizeof(int), 3562 .mode = 0644, 3563 .proc_handler = proc_dointvec, 3564 }, 3565 { 3566 .procname = "gc_elasticity", 3567 .data = &ip_rt_gc_elasticity, 3568 .maxlen = sizeof(int), 3569 .mode = 0644, 3570 .proc_handler = proc_dointvec, 3571 }, 3572}; 3573 3574static const char ipv4_route_flush_procname[] = "flush"; 3575 3576static struct ctl_table ipv4_route_netns_table[] = { 3577 { 3578 .procname = ipv4_route_flush_procname, 3579 .maxlen = sizeof(int), 3580 .mode = 0200, 3581 .proc_handler = ipv4_sysctl_rtcache_flush, 3582 }, 3583 { 3584 .procname = "min_pmtu", 3585 .data = &init_net.ipv4.ip_rt_min_pmtu, 3586 .maxlen = sizeof(int), 3587 .mode = 0644, 3588 .proc_handler = proc_dointvec_minmax, 3589 .extra1 = &ip_min_valid_pmtu, 3590 }, 3591 { 3592 .procname = "mtu_expires", 3593 .data = &init_net.ipv4.ip_rt_mtu_expires, 3594 .maxlen = sizeof(int), 3595 .mode = 0644, 3596 .proc_handler = proc_dointvec_jiffies, 3597 }, 3598 { 3599 .procname = "min_adv_mss", 3600 .data = &init_net.ipv4.ip_rt_min_advmss, 3601 .maxlen = sizeof(int), 3602 .mode = 0644, 3603 .proc_handler = proc_dointvec, 3604 }, 3605}; 3606 3607static __net_init int sysctl_route_net_init(struct net *net) 3608{ 3609 struct ctl_table *tbl; 3610 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3611 3612 tbl = ipv4_route_netns_table; 3613 if (!net_eq(net, &init_net)) { 3614 int i; 3615 3616 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3617 if (!tbl) 3618 goto err_dup; 3619 3620 /* Don't export non-whitelisted sysctls to unprivileged users */ 3621 if (net->user_ns != &init_user_ns) { 3622 if (tbl[0].procname != ipv4_route_flush_procname) 3623 table_size = 0; 3624 } 3625 3626 /* Update the variables to point into the current struct net 3627 * except for the first element flush 3628 */ 3629 for (i = 1; i < table_size; i++) 3630 tbl[i].data += (void *)net - (void *)&init_net; 3631 } 3632 tbl[0].extra1 = net; 3633 3634 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3635 tbl, table_size); 3636 if (!net->ipv4.route_hdr) 3637 goto err_reg; 3638 return 0; 3639 3640err_reg: 3641 if (tbl != ipv4_route_netns_table) 3642 kfree(tbl); 3643err_dup: 3644 return -ENOMEM; 3645} 3646 3647static __net_exit void sysctl_route_net_exit(struct net *net) 3648{ 3649 const struct ctl_table *tbl; 3650 3651 tbl = net->ipv4.route_hdr->ctl_table_arg; 3652 unregister_net_sysctl_table(net->ipv4.route_hdr); 3653 BUG_ON(tbl == ipv4_route_netns_table); 3654 kfree(tbl); 3655} 3656 3657static __net_initdata struct pernet_operations sysctl_route_ops = { 3658 .init = sysctl_route_net_init, 3659 .exit = sysctl_route_net_exit, 3660}; 3661#endif 3662 3663static __net_init int netns_ip_rt_init(struct net *net) 3664{ 3665 /* Set default value for namespaceified sysctls */ 3666 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3667 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3668 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3669 return 0; 3670} 3671 3672static struct pernet_operations __net_initdata ip_rt_ops = { 3673 .init = netns_ip_rt_init, 3674}; 3675 3676static __net_init int rt_genid_init(struct net *net) 3677{ 3678 atomic_set(&net->ipv4.rt_genid, 0); 3679 atomic_set(&net->fnhe_genid, 0); 3680 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3681 return 0; 3682} 3683 3684static __net_initdata struct pernet_operations rt_genid_ops = { 3685 .init = rt_genid_init, 3686}; 3687 3688static int __net_init ipv4_inetpeer_init(struct net *net) 3689{ 3690 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3691 3692 if (!bp) 3693 return -ENOMEM; 3694 inet_peer_base_init(bp); 3695 net->ipv4.peers = bp; 3696 return 0; 3697} 3698 3699static void __net_exit ipv4_inetpeer_exit(struct net *net) 3700{ 3701 struct inet_peer_base *bp = net->ipv4.peers; 3702 3703 net->ipv4.peers = NULL; 3704 inetpeer_invalidate_tree(bp); 3705 kfree(bp); 3706} 3707 3708static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3709 .init = ipv4_inetpeer_init, 3710 .exit = ipv4_inetpeer_exit, 3711}; 3712 3713#ifdef CONFIG_IP_ROUTE_CLASSID 3714struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3715#endif /* CONFIG_IP_ROUTE_CLASSID */ 3716 3717static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3718 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3719 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3720}; 3721 3722int __init ip_rt_init(void) 3723{ 3724 void *idents_hash; 3725 int cpu; 3726 3727 /* For modern hosts, this will use 2 MB of memory */ 3728 idents_hash = alloc_large_system_hash("IP idents", 3729 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3730 0, 3731 16, /* one bucket per 64 KB */ 3732 HASH_ZERO, 3733 NULL, 3734 &ip_idents_mask, 3735 2048, 3736 256*1024); 3737 3738 ip_idents = idents_hash; 3739 3740 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3741 3742 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3743 3744 for_each_possible_cpu(cpu) { 3745 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3746 3747 INIT_LIST_HEAD(&ul->head); 3748 spin_lock_init(&ul->lock); 3749 } 3750#ifdef CONFIG_IP_ROUTE_CLASSID 3751 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3752 if (!ip_rt_acct) 3753 panic("IP: failed to allocate ip_rt_acct\n"); 3754#endif 3755 3756 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3757 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3758 3759 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3760 3761 if (dst_entries_init(&ipv4_dst_ops) < 0) 3762 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3763 3764 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3765 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3766 3767 ipv4_dst_ops.gc_thresh = ~0; 3768 ip_rt_max_size = INT_MAX; 3769 3770 devinet_init(); 3771 ip_fib_init(); 3772 3773 if (ip_rt_proc_init()) 3774 pr_err("Unable to create route proc files\n"); 3775#ifdef CONFIG_XFRM 3776 xfrm_init(); 3777 xfrm4_init(); 3778#endif 3779 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3780 3781#ifdef CONFIG_SYSCTL 3782 register_pernet_subsys(&sysctl_route_ops); 3783#endif 3784 register_pernet_subsys(&ip_rt_ops); 3785 register_pernet_subsys(&rt_genid_ops); 3786 register_pernet_subsys(&ipv4_inetpeer_ops); 3787 return 0; 3788} 3789 3790#ifdef CONFIG_SYSCTL 3791/* 3792 * We really need to sanitize the damn ipv4 init order, then all 3793 * this nonsense will go away. 3794 */ 3795void __init ip_static_sysctl_init(void) 3796{ 3797 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3798} 3799#endif
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