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/inet_dscp.h> 88 #include <net/net_namespace.h> 89 #include <net/ip.h> 90 #include <net/route.h> 91 #include <net/inetpeer.h> 92 #include <net/sock.h> 93 #include <net/ip_fib.h> 94 #include <net/nexthop.h> 95 #include <net/tcp.h> 96 #include <net/icmp.h> 97 #include <net/xfrm.h> 98 #include <net/lwtunnel.h> 99 #include <net/netevent.h> 100 #include <net/rtnetlink.h> 101 #ifdef CONFIG_SYSCTL 102 #include <linux/sysctl.h> 103 #endif 104 #include <net/secure_seq.h> 105 #include <net/ip_tunnels.h> 106 107 #include "fib_lookup.h" 108 109 #define RT_GC_TIMEOUT (300*HZ) 110 111 #define DEFAULT_MIN_PMTU (512 + 20 + 20) 112 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ) 113 #define DEFAULT_MIN_ADVMSS 256 114 static int ip_rt_max_size; 115 static int ip_rt_redirect_number __read_mostly = 9; 116 static int ip_rt_redirect_load __read_mostly = HZ / 50; 117 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 118 static int ip_rt_error_cost __read_mostly = HZ; 119 static int ip_rt_error_burst __read_mostly = 5 * HZ; 120 121 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 122 123 /* 124 * Interface to generic destination cache. 125 */ 126 127 INDIRECT_CALLABLE_SCOPE 128 struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 129 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 130 INDIRECT_CALLABLE_SCOPE 131 unsigned int ipv4_mtu(const struct dst_entry *dst); 132 static void ipv4_negative_advice(struct sock *sk, 133 struct dst_entry *dst); 134 static void ipv4_link_failure(struct sk_buff *skb); 135 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 136 struct sk_buff *skb, u32 mtu, 137 bool confirm_neigh); 138 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 139 struct sk_buff *skb); 140 static void ipv4_dst_destroy(struct dst_entry *dst); 141 142 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 143 { 144 WARN_ON(1); 145 return NULL; 146 } 147 148 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 149 struct sk_buff *skb, 150 const void *daddr); 151 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 152 153 static struct dst_ops ipv4_dst_ops = { 154 .family = AF_INET, 155 .check = ipv4_dst_check, 156 .default_advmss = ipv4_default_advmss, 157 .mtu = ipv4_mtu, 158 .cow_metrics = ipv4_cow_metrics, 159 .destroy = ipv4_dst_destroy, 160 .negative_advice = ipv4_negative_advice, 161 .link_failure = ipv4_link_failure, 162 .update_pmtu = ip_rt_update_pmtu, 163 .redirect = ip_do_redirect, 164 .local_out = __ip_local_out, 165 .neigh_lookup = ipv4_neigh_lookup, 166 .confirm_neigh = ipv4_confirm_neigh, 167 }; 168 169 #define ECN_OR_COST(class) TC_PRIO_##class 170 171 const __u8 ip_tos2prio[16] = { 172 TC_PRIO_BESTEFFORT, 173 ECN_OR_COST(BESTEFFORT), 174 TC_PRIO_BESTEFFORT, 175 ECN_OR_COST(BESTEFFORT), 176 TC_PRIO_BULK, 177 ECN_OR_COST(BULK), 178 TC_PRIO_BULK, 179 ECN_OR_COST(BULK), 180 TC_PRIO_INTERACTIVE, 181 ECN_OR_COST(INTERACTIVE), 182 TC_PRIO_INTERACTIVE, 183 ECN_OR_COST(INTERACTIVE), 184 TC_PRIO_INTERACTIVE_BULK, 185 ECN_OR_COST(INTERACTIVE_BULK), 186 TC_PRIO_INTERACTIVE_BULK, 187 ECN_OR_COST(INTERACTIVE_BULK) 188 }; 189 EXPORT_SYMBOL(ip_tos2prio); 190 191 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 192 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 193 194 #ifdef CONFIG_PROC_FS 195 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 196 { 197 if (*pos) 198 return NULL; 199 return SEQ_START_TOKEN; 200 } 201 202 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 203 { 204 ++*pos; 205 return NULL; 206 } 207 208 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 209 { 210 } 211 212 static int rt_cache_seq_show(struct seq_file *seq, void *v) 213 { 214 if (v == SEQ_START_TOKEN) 215 seq_printf(seq, "%-127s\n", 216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 218 "HHUptod\tSpecDst"); 219 return 0; 220 } 221 222 static const struct seq_operations rt_cache_seq_ops = { 223 .start = rt_cache_seq_start, 224 .next = rt_cache_seq_next, 225 .stop = rt_cache_seq_stop, 226 .show = rt_cache_seq_show, 227 }; 228 229 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 230 { 231 int cpu; 232 233 if (*pos == 0) 234 return SEQ_START_TOKEN; 235 236 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 237 if (!cpu_possible(cpu)) 238 continue; 239 *pos = cpu+1; 240 return &per_cpu(rt_cache_stat, cpu); 241 } 242 return NULL; 243 } 244 245 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 246 { 247 int cpu; 248 249 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 250 if (!cpu_possible(cpu)) 251 continue; 252 *pos = cpu+1; 253 return &per_cpu(rt_cache_stat, cpu); 254 } 255 (*pos)++; 256 return NULL; 257 258 } 259 260 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 261 { 262 263 } 264 265 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 266 { 267 struct rt_cache_stat *st = v; 268 269 if (v == SEQ_START_TOKEN) { 270 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"); 271 return 0; 272 } 273 274 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 275 "%08x %08x %08x %08x %08x %08x " 276 "%08x %08x %08x %08x\n", 277 dst_entries_get_slow(&ipv4_dst_ops), 278 0, /* st->in_hit */ 279 st->in_slow_tot, 280 st->in_slow_mc, 281 st->in_no_route, 282 st->in_brd, 283 st->in_martian_dst, 284 st->in_martian_src, 285 286 0, /* st->out_hit */ 287 st->out_slow_tot, 288 st->out_slow_mc, 289 290 0, /* st->gc_total */ 291 0, /* st->gc_ignored */ 292 0, /* st->gc_goal_miss */ 293 0, /* st->gc_dst_overflow */ 294 0, /* st->in_hlist_search */ 295 0 /* st->out_hlist_search */ 296 ); 297 return 0; 298 } 299 300 static const struct seq_operations rt_cpu_seq_ops = { 301 .start = rt_cpu_seq_start, 302 .next = rt_cpu_seq_next, 303 .stop = rt_cpu_seq_stop, 304 .show = rt_cpu_seq_show, 305 }; 306 307 #ifdef CONFIG_IP_ROUTE_CLASSID 308 static int rt_acct_proc_show(struct seq_file *m, void *v) 309 { 310 struct ip_rt_acct *dst, *src; 311 unsigned int i, j; 312 313 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 314 if (!dst) 315 return -ENOMEM; 316 317 for_each_possible_cpu(i) { 318 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 319 for (j = 0; j < 256; j++) { 320 dst[j].o_bytes += src[j].o_bytes; 321 dst[j].o_packets += src[j].o_packets; 322 dst[j].i_bytes += src[j].i_bytes; 323 dst[j].i_packets += src[j].i_packets; 324 } 325 } 326 327 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 328 kfree(dst); 329 return 0; 330 } 331 #endif 332 333 static int __net_init ip_rt_do_proc_init(struct net *net) 334 { 335 struct proc_dir_entry *pde; 336 337 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 338 &rt_cache_seq_ops); 339 if (!pde) 340 goto err1; 341 342 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 343 &rt_cpu_seq_ops); 344 if (!pde) 345 goto err2; 346 347 #ifdef CONFIG_IP_ROUTE_CLASSID 348 pde = proc_create_single("rt_acct", 0, net->proc_net, 349 rt_acct_proc_show); 350 if (!pde) 351 goto err3; 352 #endif 353 return 0; 354 355 #ifdef CONFIG_IP_ROUTE_CLASSID 356 err3: 357 remove_proc_entry("rt_cache", net->proc_net_stat); 358 #endif 359 err2: 360 remove_proc_entry("rt_cache", net->proc_net); 361 err1: 362 return -ENOMEM; 363 } 364 365 static void __net_exit ip_rt_do_proc_exit(struct net *net) 366 { 367 remove_proc_entry("rt_cache", net->proc_net_stat); 368 remove_proc_entry("rt_cache", net->proc_net); 369 #ifdef CONFIG_IP_ROUTE_CLASSID 370 remove_proc_entry("rt_acct", net->proc_net); 371 #endif 372 } 373 374 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 375 .init = ip_rt_do_proc_init, 376 .exit = ip_rt_do_proc_exit, 377 }; 378 379 static int __init ip_rt_proc_init(void) 380 { 381 return register_pernet_subsys(&ip_rt_proc_ops); 382 } 383 384 #else 385 static inline int ip_rt_proc_init(void) 386 { 387 return 0; 388 } 389 #endif /* CONFIG_PROC_FS */ 390 391 static inline bool rt_is_expired(const struct rtable *rth) 392 { 393 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 394 } 395 396 void rt_cache_flush(struct net *net) 397 { 398 rt_genid_bump_ipv4(net); 399 } 400 401 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 402 struct sk_buff *skb, 403 const void *daddr) 404 { 405 const struct rtable *rt = container_of(dst, struct rtable, dst); 406 struct net_device *dev = dst->dev; 407 struct neighbour *n; 408 409 rcu_read_lock(); 410 411 if (likely(rt->rt_gw_family == AF_INET)) { 412 n = ip_neigh_gw4(dev, rt->rt_gw4); 413 } else if (rt->rt_gw_family == AF_INET6) { 414 n = ip_neigh_gw6(dev, &rt->rt_gw6); 415 } else { 416 __be32 pkey; 417 418 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 419 n = ip_neigh_gw4(dev, pkey); 420 } 421 422 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 423 n = NULL; 424 425 rcu_read_unlock(); 426 427 return n; 428 } 429 430 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 431 { 432 const struct rtable *rt = container_of(dst, struct rtable, dst); 433 struct net_device *dev = dst->dev; 434 const __be32 *pkey = daddr; 435 436 if (rt->rt_gw_family == AF_INET) { 437 pkey = (const __be32 *)&rt->rt_gw4; 438 } else if (rt->rt_gw_family == AF_INET6) { 439 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 440 } else if (!daddr || 441 (rt->rt_flags & 442 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 443 return; 444 } 445 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 446 } 447 448 /* Hash tables of size 2048..262144 depending on RAM size. 449 * Each bucket uses 8 bytes. 450 */ 451 static u32 ip_idents_mask __read_mostly; 452 static atomic_t *ip_idents __read_mostly; 453 static u32 *ip_tstamps __read_mostly; 454 455 /* In order to protect privacy, we add a perturbation to identifiers 456 * if one generator is seldom used. This makes hard for an attacker 457 * to infer how many packets were sent between two points in time. 458 */ 459 static u32 ip_idents_reserve(u32 hash, int segs) 460 { 461 u32 bucket, old, now = (u32)jiffies; 462 atomic_t *p_id; 463 u32 *p_tstamp; 464 u32 delta = 0; 465 466 bucket = hash & ip_idents_mask; 467 p_tstamp = ip_tstamps + bucket; 468 p_id = ip_idents + bucket; 469 old = READ_ONCE(*p_tstamp); 470 471 if (old != now && cmpxchg(p_tstamp, old, now) == old) 472 delta = get_random_u32_below(now - old); 473 474 /* If UBSAN reports an error there, please make sure your compiler 475 * supports -fno-strict-overflow before reporting it that was a bug 476 * in UBSAN, and it has been fixed in GCC-8. 477 */ 478 return atomic_add_return(segs + delta, p_id) - segs; 479 } 480 481 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 482 { 483 u32 hash, id; 484 485 /* Note the following code is not safe, but this is okay. */ 486 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 487 get_random_bytes(&net->ipv4.ip_id_key, 488 sizeof(net->ipv4.ip_id_key)); 489 490 hash = siphash_3u32((__force u32)iph->daddr, 491 (__force u32)iph->saddr, 492 iph->protocol, 493 &net->ipv4.ip_id_key); 494 id = ip_idents_reserve(hash, segs); 495 iph->id = htons(id); 496 } 497 EXPORT_SYMBOL(__ip_select_ident); 498 499 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 500 const struct sock *sk, const struct iphdr *iph, 501 int oif, __u8 tos, u8 prot, u32 mark, 502 int flow_flags) 503 { 504 __u8 scope = RT_SCOPE_UNIVERSE; 505 506 if (sk) { 507 oif = sk->sk_bound_dev_if; 508 mark = READ_ONCE(sk->sk_mark); 509 tos = ip_sock_rt_tos(sk); 510 scope = ip_sock_rt_scope(sk); 511 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 512 sk->sk_protocol; 513 } 514 515 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope, 516 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 517 sock_net_uid(net, sk)); 518 } 519 520 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 521 const struct sock *sk) 522 { 523 const struct net *net = dev_net(skb->dev); 524 const struct iphdr *iph = ip_hdr(skb); 525 int oif = skb->dev->ifindex; 526 u8 prot = iph->protocol; 527 u32 mark = skb->mark; 528 __u8 tos = iph->tos; 529 530 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 531 } 532 533 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 534 { 535 const struct inet_sock *inet = inet_sk(sk); 536 const struct ip_options_rcu *inet_opt; 537 __be32 daddr = inet->inet_daddr; 538 539 rcu_read_lock(); 540 inet_opt = rcu_dereference(inet->inet_opt); 541 if (inet_opt && inet_opt->opt.srr) 542 daddr = inet_opt->opt.faddr; 543 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 544 ip_sock_rt_tos(sk), 545 ip_sock_rt_scope(sk), 546 inet_test_bit(HDRINCL, sk) ? 547 IPPROTO_RAW : sk->sk_protocol, 548 inet_sk_flowi_flags(sk), 549 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 550 rcu_read_unlock(); 551 } 552 553 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 554 const struct sk_buff *skb) 555 { 556 if (skb) 557 build_skb_flow_key(fl4, skb, sk); 558 else 559 build_sk_flow_key(fl4, sk); 560 } 561 562 static DEFINE_SPINLOCK(fnhe_lock); 563 564 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 565 { 566 struct rtable *rt; 567 568 rt = rcu_dereference(fnhe->fnhe_rth_input); 569 if (rt) { 570 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 571 dst_dev_put(&rt->dst); 572 dst_release(&rt->dst); 573 } 574 rt = rcu_dereference(fnhe->fnhe_rth_output); 575 if (rt) { 576 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 577 dst_dev_put(&rt->dst); 578 dst_release(&rt->dst); 579 } 580 } 581 582 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 583 { 584 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 585 struct fib_nh_exception *fnhe, *oldest = NULL; 586 587 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 588 fnhe = rcu_dereference_protected(*fnhe_p, 589 lockdep_is_held(&fnhe_lock)); 590 if (!fnhe) 591 break; 592 if (!oldest || 593 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 594 oldest = fnhe; 595 oldest_p = fnhe_p; 596 } 597 } 598 fnhe_flush_routes(oldest); 599 *oldest_p = oldest->fnhe_next; 600 kfree_rcu(oldest, rcu); 601 } 602 603 static u32 fnhe_hashfun(__be32 daddr) 604 { 605 static siphash_aligned_key_t fnhe_hash_key; 606 u64 hval; 607 608 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 609 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 610 return hash_64(hval, FNHE_HASH_SHIFT); 611 } 612 613 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 614 { 615 rt->rt_pmtu = fnhe->fnhe_pmtu; 616 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 617 rt->dst.expires = fnhe->fnhe_expires; 618 619 if (fnhe->fnhe_gw) { 620 rt->rt_flags |= RTCF_REDIRECTED; 621 rt->rt_uses_gateway = 1; 622 rt->rt_gw_family = AF_INET; 623 rt->rt_gw4 = fnhe->fnhe_gw; 624 } 625 } 626 627 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 628 __be32 gw, u32 pmtu, bool lock, 629 unsigned long expires) 630 { 631 struct fnhe_hash_bucket *hash; 632 struct fib_nh_exception *fnhe; 633 struct rtable *rt; 634 u32 genid, hval; 635 unsigned int i; 636 int depth; 637 638 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 639 hval = fnhe_hashfun(daddr); 640 641 spin_lock_bh(&fnhe_lock); 642 643 hash = rcu_dereference(nhc->nhc_exceptions); 644 if (!hash) { 645 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 646 if (!hash) 647 goto out_unlock; 648 rcu_assign_pointer(nhc->nhc_exceptions, hash); 649 } 650 651 hash += hval; 652 653 depth = 0; 654 for (fnhe = rcu_dereference(hash->chain); fnhe; 655 fnhe = rcu_dereference(fnhe->fnhe_next)) { 656 if (fnhe->fnhe_daddr == daddr) 657 break; 658 depth++; 659 } 660 661 if (fnhe) { 662 if (fnhe->fnhe_genid != genid) 663 fnhe->fnhe_genid = genid; 664 if (gw) 665 fnhe->fnhe_gw = gw; 666 if (pmtu) { 667 fnhe->fnhe_pmtu = pmtu; 668 fnhe->fnhe_mtu_locked = lock; 669 } 670 fnhe->fnhe_expires = max(1UL, expires); 671 /* Update all cached dsts too */ 672 rt = rcu_dereference(fnhe->fnhe_rth_input); 673 if (rt) 674 fill_route_from_fnhe(rt, fnhe); 675 rt = rcu_dereference(fnhe->fnhe_rth_output); 676 if (rt) 677 fill_route_from_fnhe(rt, fnhe); 678 } else { 679 /* Randomize max depth to avoid some side channels attacks. */ 680 int max_depth = FNHE_RECLAIM_DEPTH + 681 get_random_u32_below(FNHE_RECLAIM_DEPTH); 682 683 while (depth > max_depth) { 684 fnhe_remove_oldest(hash); 685 depth--; 686 } 687 688 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 689 if (!fnhe) 690 goto out_unlock; 691 692 fnhe->fnhe_next = hash->chain; 693 694 fnhe->fnhe_genid = genid; 695 fnhe->fnhe_daddr = daddr; 696 fnhe->fnhe_gw = gw; 697 fnhe->fnhe_pmtu = pmtu; 698 fnhe->fnhe_mtu_locked = lock; 699 fnhe->fnhe_expires = max(1UL, expires); 700 701 rcu_assign_pointer(hash->chain, fnhe); 702 703 /* Exception created; mark the cached routes for the nexthop 704 * stale, so anyone caching it rechecks if this exception 705 * applies to them. 706 */ 707 rt = rcu_dereference(nhc->nhc_rth_input); 708 if (rt) 709 rt->dst.obsolete = DST_OBSOLETE_KILL; 710 711 for_each_possible_cpu(i) { 712 struct rtable __rcu **prt; 713 714 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 715 rt = rcu_dereference(*prt); 716 if (rt) 717 rt->dst.obsolete = DST_OBSOLETE_KILL; 718 } 719 } 720 721 fnhe->fnhe_stamp = jiffies; 722 723 out_unlock: 724 spin_unlock_bh(&fnhe_lock); 725 } 726 727 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 728 bool kill_route) 729 { 730 __be32 new_gw = icmp_hdr(skb)->un.gateway; 731 __be32 old_gw = ip_hdr(skb)->saddr; 732 struct net_device *dev = skb->dev; 733 struct in_device *in_dev; 734 struct fib_result res; 735 struct neighbour *n; 736 struct net *net; 737 738 switch (icmp_hdr(skb)->code & 7) { 739 case ICMP_REDIR_NET: 740 case ICMP_REDIR_NETTOS: 741 case ICMP_REDIR_HOST: 742 case ICMP_REDIR_HOSTTOS: 743 break; 744 745 default: 746 return; 747 } 748 749 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 750 return; 751 752 in_dev = __in_dev_get_rcu(dev); 753 if (!in_dev) 754 return; 755 756 net = dev_net(dev); 757 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 758 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 759 ipv4_is_zeronet(new_gw)) 760 goto reject_redirect; 761 762 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 763 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 764 goto reject_redirect; 765 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 766 goto reject_redirect; 767 } else { 768 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 769 goto reject_redirect; 770 } 771 772 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 773 if (!n) 774 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 775 if (!IS_ERR(n)) { 776 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 777 neigh_event_send(n, NULL); 778 } else { 779 if (fib_lookup(net, fl4, &res, 0) == 0) { 780 struct fib_nh_common *nhc; 781 782 fib_select_path(net, &res, fl4, skb); 783 nhc = FIB_RES_NHC(res); 784 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 785 0, false, 786 jiffies + ip_rt_gc_timeout); 787 } 788 if (kill_route) 789 rt->dst.obsolete = DST_OBSOLETE_KILL; 790 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 791 } 792 neigh_release(n); 793 } 794 return; 795 796 reject_redirect: 797 #ifdef CONFIG_IP_ROUTE_VERBOSE 798 if (IN_DEV_LOG_MARTIANS(in_dev)) { 799 const struct iphdr *iph = (const struct iphdr *) skb->data; 800 __be32 daddr = iph->daddr; 801 __be32 saddr = iph->saddr; 802 803 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 804 " Advised path = %pI4 -> %pI4\n", 805 &old_gw, dev->name, &new_gw, 806 &saddr, &daddr); 807 } 808 #endif 809 ; 810 } 811 812 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 813 { 814 struct rtable *rt; 815 struct flowi4 fl4; 816 const struct iphdr *iph = (const struct iphdr *) skb->data; 817 struct net *net = dev_net(skb->dev); 818 int oif = skb->dev->ifindex; 819 u8 prot = iph->protocol; 820 u32 mark = skb->mark; 821 __u8 tos = iph->tos; 822 823 rt = dst_rtable(dst); 824 825 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 826 __ip_do_redirect(rt, skb, &fl4, true); 827 } 828 829 static void ipv4_negative_advice(struct sock *sk, 830 struct dst_entry *dst) 831 { 832 struct rtable *rt = dst_rtable(dst); 833 834 if ((dst->obsolete > 0) || 835 (rt->rt_flags & RTCF_REDIRECTED) || 836 rt->dst.expires) 837 sk_dst_reset(sk); 838 } 839 840 /* 841 * Algorithm: 842 * 1. The first ip_rt_redirect_number redirects are sent 843 * with exponential backoff, then we stop sending them at all, 844 * assuming that the host ignores our redirects. 845 * 2. If we did not see packets requiring redirects 846 * during ip_rt_redirect_silence, we assume that the host 847 * forgot redirected route and start to send redirects again. 848 * 849 * This algorithm is much cheaper and more intelligent than dumb load limiting 850 * in icmp.c. 851 * 852 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 853 * and "frag. need" (breaks PMTU discovery) in icmp.c. 854 */ 855 856 void ip_rt_send_redirect(struct sk_buff *skb) 857 { 858 struct rtable *rt = skb_rtable(skb); 859 struct in_device *in_dev; 860 struct inet_peer *peer; 861 struct net *net; 862 int log_martians; 863 int vif; 864 865 rcu_read_lock(); 866 in_dev = __in_dev_get_rcu(rt->dst.dev); 867 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 868 rcu_read_unlock(); 869 return; 870 } 871 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 872 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 873 rcu_read_unlock(); 874 875 net = dev_net(rt->dst.dev); 876 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 877 if (!peer) { 878 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 879 rt_nexthop(rt, ip_hdr(skb)->daddr)); 880 return; 881 } 882 883 /* No redirected packets during ip_rt_redirect_silence; 884 * reset the algorithm. 885 */ 886 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 887 peer->rate_tokens = 0; 888 peer->n_redirects = 0; 889 } 890 891 /* Too many ignored redirects; do not send anything 892 * set dst.rate_last to the last seen redirected packet. 893 */ 894 if (peer->n_redirects >= ip_rt_redirect_number) { 895 peer->rate_last = jiffies; 896 goto out_put_peer; 897 } 898 899 /* Check for load limit; set rate_last to the latest sent 900 * redirect. 901 */ 902 if (peer->n_redirects == 0 || 903 time_after(jiffies, 904 (peer->rate_last + 905 (ip_rt_redirect_load << peer->n_redirects)))) { 906 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 907 908 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 909 peer->rate_last = jiffies; 910 ++peer->n_redirects; 911 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 912 peer->n_redirects == ip_rt_redirect_number) 913 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 914 &ip_hdr(skb)->saddr, inet_iif(skb), 915 &ip_hdr(skb)->daddr, &gw); 916 } 917 out_put_peer: 918 inet_putpeer(peer); 919 } 920 921 static int ip_error(struct sk_buff *skb) 922 { 923 struct rtable *rt = skb_rtable(skb); 924 struct net_device *dev = skb->dev; 925 struct in_device *in_dev; 926 struct inet_peer *peer; 927 unsigned long now; 928 struct net *net; 929 SKB_DR(reason); 930 bool send; 931 int code; 932 933 if (netif_is_l3_master(skb->dev)) { 934 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 935 if (!dev) 936 goto out; 937 } 938 939 in_dev = __in_dev_get_rcu(dev); 940 941 /* IP on this device is disabled. */ 942 if (!in_dev) 943 goto out; 944 945 net = dev_net(rt->dst.dev); 946 if (!IN_DEV_FORWARD(in_dev)) { 947 switch (rt->dst.error) { 948 case EHOSTUNREACH: 949 SKB_DR_SET(reason, IP_INADDRERRORS); 950 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 951 break; 952 953 case ENETUNREACH: 954 SKB_DR_SET(reason, IP_INNOROUTES); 955 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 956 break; 957 } 958 goto out; 959 } 960 961 switch (rt->dst.error) { 962 case EINVAL: 963 default: 964 goto out; 965 case EHOSTUNREACH: 966 code = ICMP_HOST_UNREACH; 967 break; 968 case ENETUNREACH: 969 code = ICMP_NET_UNREACH; 970 SKB_DR_SET(reason, IP_INNOROUTES); 971 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 972 break; 973 case EACCES: 974 code = ICMP_PKT_FILTERED; 975 break; 976 } 977 978 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 979 l3mdev_master_ifindex(skb->dev), 1); 980 981 send = true; 982 if (peer) { 983 now = jiffies; 984 peer->rate_tokens += now - peer->rate_last; 985 if (peer->rate_tokens > ip_rt_error_burst) 986 peer->rate_tokens = ip_rt_error_burst; 987 peer->rate_last = now; 988 if (peer->rate_tokens >= ip_rt_error_cost) 989 peer->rate_tokens -= ip_rt_error_cost; 990 else 991 send = false; 992 inet_putpeer(peer); 993 } 994 if (send) 995 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 996 997 out: kfree_skb_reason(skb, reason); 998 return 0; 999 } 1000 1001 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1002 { 1003 struct dst_entry *dst = &rt->dst; 1004 struct net *net = dev_net(dst->dev); 1005 struct fib_result res; 1006 bool lock = false; 1007 u32 old_mtu; 1008 1009 if (ip_mtu_locked(dst)) 1010 return; 1011 1012 old_mtu = ipv4_mtu(dst); 1013 if (old_mtu < mtu) 1014 return; 1015 1016 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1017 lock = true; 1018 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1019 } 1020 1021 if (rt->rt_pmtu == mtu && !lock && 1022 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1023 return; 1024 1025 rcu_read_lock(); 1026 if (fib_lookup(net, fl4, &res, 0) == 0) { 1027 struct fib_nh_common *nhc; 1028 1029 fib_select_path(net, &res, fl4, NULL); 1030 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1031 if (fib_info_num_path(res.fi) > 1) { 1032 int nhsel; 1033 1034 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1035 nhc = fib_info_nhc(res.fi, nhsel); 1036 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1037 jiffies + net->ipv4.ip_rt_mtu_expires); 1038 } 1039 rcu_read_unlock(); 1040 return; 1041 } 1042 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1043 nhc = FIB_RES_NHC(res); 1044 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1045 jiffies + net->ipv4.ip_rt_mtu_expires); 1046 } 1047 rcu_read_unlock(); 1048 } 1049 1050 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1051 struct sk_buff *skb, u32 mtu, 1052 bool confirm_neigh) 1053 { 1054 struct rtable *rt = dst_rtable(dst); 1055 struct flowi4 fl4; 1056 1057 ip_rt_build_flow_key(&fl4, sk, skb); 1058 1059 /* Don't make lookup fail for bridged encapsulations */ 1060 if (skb && netif_is_any_bridge_port(skb->dev)) 1061 fl4.flowi4_oif = 0; 1062 1063 __ip_rt_update_pmtu(rt, &fl4, mtu); 1064 } 1065 1066 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1067 int oif, u8 protocol) 1068 { 1069 const struct iphdr *iph = (const struct iphdr *)skb->data; 1070 struct flowi4 fl4; 1071 struct rtable *rt; 1072 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1073 1074 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1075 0); 1076 rt = __ip_route_output_key(net, &fl4); 1077 if (!IS_ERR(rt)) { 1078 __ip_rt_update_pmtu(rt, &fl4, mtu); 1079 ip_rt_put(rt); 1080 } 1081 } 1082 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1083 1084 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1085 { 1086 const struct iphdr *iph = (const struct iphdr *)skb->data; 1087 struct flowi4 fl4; 1088 struct rtable *rt; 1089 1090 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1091 1092 if (!fl4.flowi4_mark) 1093 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1094 1095 rt = __ip_route_output_key(sock_net(sk), &fl4); 1096 if (!IS_ERR(rt)) { 1097 __ip_rt_update_pmtu(rt, &fl4, mtu); 1098 ip_rt_put(rt); 1099 } 1100 } 1101 1102 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1103 { 1104 const struct iphdr *iph = (const struct iphdr *)skb->data; 1105 struct flowi4 fl4; 1106 struct rtable *rt; 1107 struct dst_entry *odst = NULL; 1108 bool new = false; 1109 struct net *net = sock_net(sk); 1110 1111 bh_lock_sock(sk); 1112 1113 if (!ip_sk_accept_pmtu(sk)) 1114 goto out; 1115 1116 odst = sk_dst_get(sk); 1117 1118 if (sock_owned_by_user(sk) || !odst) { 1119 __ipv4_sk_update_pmtu(skb, sk, mtu); 1120 goto out; 1121 } 1122 1123 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1124 1125 rt = dst_rtable(odst); 1126 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1127 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1128 if (IS_ERR(rt)) 1129 goto out; 1130 1131 new = true; 1132 } 1133 1134 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1135 1136 if (!dst_check(&rt->dst, 0)) { 1137 if (new) 1138 dst_release(&rt->dst); 1139 1140 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1141 if (IS_ERR(rt)) 1142 goto out; 1143 1144 new = true; 1145 } 1146 1147 if (new) 1148 sk_dst_set(sk, &rt->dst); 1149 1150 out: 1151 bh_unlock_sock(sk); 1152 dst_release(odst); 1153 } 1154 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1155 1156 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1157 int oif, u8 protocol) 1158 { 1159 const struct iphdr *iph = (const struct iphdr *)skb->data; 1160 struct flowi4 fl4; 1161 struct rtable *rt; 1162 1163 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1164 rt = __ip_route_output_key(net, &fl4); 1165 if (!IS_ERR(rt)) { 1166 __ip_do_redirect(rt, skb, &fl4, false); 1167 ip_rt_put(rt); 1168 } 1169 } 1170 EXPORT_SYMBOL_GPL(ipv4_redirect); 1171 1172 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1173 { 1174 const struct iphdr *iph = (const struct iphdr *)skb->data; 1175 struct flowi4 fl4; 1176 struct rtable *rt; 1177 struct net *net = sock_net(sk); 1178 1179 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1180 rt = __ip_route_output_key(net, &fl4); 1181 if (!IS_ERR(rt)) { 1182 __ip_do_redirect(rt, skb, &fl4, false); 1183 ip_rt_put(rt); 1184 } 1185 } 1186 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1187 1188 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1189 u32 cookie) 1190 { 1191 struct rtable *rt = dst_rtable(dst); 1192 1193 /* All IPV4 dsts are created with ->obsolete set to the value 1194 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1195 * into this function always. 1196 * 1197 * When a PMTU/redirect information update invalidates a route, 1198 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1199 * DST_OBSOLETE_DEAD. 1200 */ 1201 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1202 return NULL; 1203 return dst; 1204 } 1205 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1206 1207 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1208 { 1209 struct net_device *dev; 1210 struct ip_options opt; 1211 int res; 1212 1213 /* Recompile ip options since IPCB may not be valid anymore. 1214 * Also check we have a reasonable ipv4 header. 1215 */ 1216 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1217 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1218 return; 1219 1220 memset(&opt, 0, sizeof(opt)); 1221 if (ip_hdr(skb)->ihl > 5) { 1222 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1223 return; 1224 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1225 1226 rcu_read_lock(); 1227 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1228 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); 1229 rcu_read_unlock(); 1230 1231 if (res) 1232 return; 1233 } 1234 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1235 } 1236 1237 static void ipv4_link_failure(struct sk_buff *skb) 1238 { 1239 struct rtable *rt; 1240 1241 ipv4_send_dest_unreach(skb); 1242 1243 rt = skb_rtable(skb); 1244 if (rt) 1245 dst_set_expires(&rt->dst, 0); 1246 } 1247 1248 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1249 { 1250 pr_debug("%s: %pI4 -> %pI4, %s\n", 1251 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1252 skb->dev ? skb->dev->name : "?"); 1253 kfree_skb(skb); 1254 WARN_ON(1); 1255 return 0; 1256 } 1257 1258 /* 1259 * We do not cache source address of outgoing interface, 1260 * because it is used only by IP RR, TS and SRR options, 1261 * so that it out of fast path. 1262 * 1263 * BTW remember: "addr" is allowed to be not aligned 1264 * in IP options! 1265 */ 1266 1267 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1268 { 1269 __be32 src; 1270 1271 if (rt_is_output_route(rt)) 1272 src = ip_hdr(skb)->saddr; 1273 else { 1274 struct fib_result res; 1275 struct iphdr *iph = ip_hdr(skb); 1276 struct flowi4 fl4 = { 1277 .daddr = iph->daddr, 1278 .saddr = iph->saddr, 1279 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)), 1280 .flowi4_oif = rt->dst.dev->ifindex, 1281 .flowi4_iif = skb->dev->ifindex, 1282 .flowi4_mark = skb->mark, 1283 }; 1284 1285 rcu_read_lock(); 1286 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1287 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1288 else 1289 src = inet_select_addr(rt->dst.dev, 1290 rt_nexthop(rt, iph->daddr), 1291 RT_SCOPE_UNIVERSE); 1292 rcu_read_unlock(); 1293 } 1294 memcpy(addr, &src, 4); 1295 } 1296 1297 #ifdef CONFIG_IP_ROUTE_CLASSID 1298 static void set_class_tag(struct rtable *rt, u32 tag) 1299 { 1300 if (!(rt->dst.tclassid & 0xFFFF)) 1301 rt->dst.tclassid |= tag & 0xFFFF; 1302 if (!(rt->dst.tclassid & 0xFFFF0000)) 1303 rt->dst.tclassid |= tag & 0xFFFF0000; 1304 } 1305 #endif 1306 1307 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1308 { 1309 struct net *net = dev_net(dst->dev); 1310 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1311 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1312 net->ipv4.ip_rt_min_advmss); 1313 1314 return min(advmss, IPV4_MAX_PMTU - header_size); 1315 } 1316 1317 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1318 { 1319 return ip_dst_mtu_maybe_forward(dst, false); 1320 } 1321 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1322 1323 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1324 { 1325 struct fnhe_hash_bucket *hash; 1326 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1327 u32 hval = fnhe_hashfun(daddr); 1328 1329 spin_lock_bh(&fnhe_lock); 1330 1331 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1332 lockdep_is_held(&fnhe_lock)); 1333 hash += hval; 1334 1335 fnhe_p = &hash->chain; 1336 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1337 while (fnhe) { 1338 if (fnhe->fnhe_daddr == daddr) { 1339 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1340 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1341 /* set fnhe_daddr to 0 to ensure it won't bind with 1342 * new dsts in rt_bind_exception(). 1343 */ 1344 fnhe->fnhe_daddr = 0; 1345 fnhe_flush_routes(fnhe); 1346 kfree_rcu(fnhe, rcu); 1347 break; 1348 } 1349 fnhe_p = &fnhe->fnhe_next; 1350 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1351 lockdep_is_held(&fnhe_lock)); 1352 } 1353 1354 spin_unlock_bh(&fnhe_lock); 1355 } 1356 1357 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1358 __be32 daddr) 1359 { 1360 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1361 struct fib_nh_exception *fnhe; 1362 u32 hval; 1363 1364 if (!hash) 1365 return NULL; 1366 1367 hval = fnhe_hashfun(daddr); 1368 1369 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1370 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1371 if (fnhe->fnhe_daddr == daddr) { 1372 if (fnhe->fnhe_expires && 1373 time_after(jiffies, fnhe->fnhe_expires)) { 1374 ip_del_fnhe(nhc, daddr); 1375 break; 1376 } 1377 return fnhe; 1378 } 1379 } 1380 return NULL; 1381 } 1382 1383 /* MTU selection: 1384 * 1. mtu on route is locked - use it 1385 * 2. mtu from nexthop exception 1386 * 3. mtu from egress device 1387 */ 1388 1389 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1390 { 1391 struct fib_nh_common *nhc = res->nhc; 1392 struct net_device *dev = nhc->nhc_dev; 1393 struct fib_info *fi = res->fi; 1394 u32 mtu = 0; 1395 1396 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1397 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1398 mtu = fi->fib_mtu; 1399 1400 if (likely(!mtu)) { 1401 struct fib_nh_exception *fnhe; 1402 1403 fnhe = find_exception(nhc, daddr); 1404 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1405 mtu = fnhe->fnhe_pmtu; 1406 } 1407 1408 if (likely(!mtu)) 1409 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1410 1411 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1412 } 1413 1414 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1415 __be32 daddr, const bool do_cache) 1416 { 1417 bool ret = false; 1418 1419 spin_lock_bh(&fnhe_lock); 1420 1421 if (daddr == fnhe->fnhe_daddr) { 1422 struct rtable __rcu **porig; 1423 struct rtable *orig; 1424 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1425 1426 if (rt_is_input_route(rt)) 1427 porig = &fnhe->fnhe_rth_input; 1428 else 1429 porig = &fnhe->fnhe_rth_output; 1430 orig = rcu_dereference(*porig); 1431 1432 if (fnhe->fnhe_genid != genid) { 1433 fnhe->fnhe_genid = genid; 1434 fnhe->fnhe_gw = 0; 1435 fnhe->fnhe_pmtu = 0; 1436 fnhe->fnhe_expires = 0; 1437 fnhe->fnhe_mtu_locked = false; 1438 fnhe_flush_routes(fnhe); 1439 orig = NULL; 1440 } 1441 fill_route_from_fnhe(rt, fnhe); 1442 if (!rt->rt_gw4) { 1443 rt->rt_gw4 = daddr; 1444 rt->rt_gw_family = AF_INET; 1445 } 1446 1447 if (do_cache) { 1448 dst_hold(&rt->dst); 1449 rcu_assign_pointer(*porig, rt); 1450 if (orig) { 1451 dst_dev_put(&orig->dst); 1452 dst_release(&orig->dst); 1453 } 1454 ret = true; 1455 } 1456 1457 fnhe->fnhe_stamp = jiffies; 1458 } 1459 spin_unlock_bh(&fnhe_lock); 1460 1461 return ret; 1462 } 1463 1464 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1465 { 1466 struct rtable *orig, *prev, **p; 1467 bool ret = true; 1468 1469 if (rt_is_input_route(rt)) { 1470 p = (struct rtable **)&nhc->nhc_rth_input; 1471 } else { 1472 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1473 } 1474 orig = *p; 1475 1476 /* hold dst before doing cmpxchg() to avoid race condition 1477 * on this dst 1478 */ 1479 dst_hold(&rt->dst); 1480 prev = cmpxchg(p, orig, rt); 1481 if (prev == orig) { 1482 if (orig) { 1483 rt_add_uncached_list(orig); 1484 dst_release(&orig->dst); 1485 } 1486 } else { 1487 dst_release(&rt->dst); 1488 ret = false; 1489 } 1490 1491 return ret; 1492 } 1493 1494 struct uncached_list { 1495 spinlock_t lock; 1496 struct list_head head; 1497 }; 1498 1499 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1500 1501 void rt_add_uncached_list(struct rtable *rt) 1502 { 1503 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1504 1505 rt->dst.rt_uncached_list = ul; 1506 1507 spin_lock_bh(&ul->lock); 1508 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1509 spin_unlock_bh(&ul->lock); 1510 } 1511 1512 void rt_del_uncached_list(struct rtable *rt) 1513 { 1514 if (!list_empty(&rt->dst.rt_uncached)) { 1515 struct uncached_list *ul = rt->dst.rt_uncached_list; 1516 1517 spin_lock_bh(&ul->lock); 1518 list_del_init(&rt->dst.rt_uncached); 1519 spin_unlock_bh(&ul->lock); 1520 } 1521 } 1522 1523 static void ipv4_dst_destroy(struct dst_entry *dst) 1524 { 1525 ip_dst_metrics_put(dst); 1526 rt_del_uncached_list(dst_rtable(dst)); 1527 } 1528 1529 void rt_flush_dev(struct net_device *dev) 1530 { 1531 struct rtable *rt, *safe; 1532 int cpu; 1533 1534 for_each_possible_cpu(cpu) { 1535 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1536 1537 if (list_empty(&ul->head)) 1538 continue; 1539 1540 spin_lock_bh(&ul->lock); 1541 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1542 if (rt->dst.dev != dev) 1543 continue; 1544 rt->dst.dev = blackhole_netdev; 1545 netdev_ref_replace(dev, blackhole_netdev, 1546 &rt->dst.dev_tracker, GFP_ATOMIC); 1547 list_del_init(&rt->dst.rt_uncached); 1548 } 1549 spin_unlock_bh(&ul->lock); 1550 } 1551 } 1552 1553 static bool rt_cache_valid(const struct rtable *rt) 1554 { 1555 return rt && 1556 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1557 !rt_is_expired(rt); 1558 } 1559 1560 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1561 const struct fib_result *res, 1562 struct fib_nh_exception *fnhe, 1563 struct fib_info *fi, u16 type, u32 itag, 1564 const bool do_cache) 1565 { 1566 bool cached = false; 1567 1568 if (fi) { 1569 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1570 1571 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1572 rt->rt_uses_gateway = 1; 1573 rt->rt_gw_family = nhc->nhc_gw_family; 1574 /* only INET and INET6 are supported */ 1575 if (likely(nhc->nhc_gw_family == AF_INET)) 1576 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1577 else 1578 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1579 } 1580 1581 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1582 1583 #ifdef CONFIG_IP_ROUTE_CLASSID 1584 if (nhc->nhc_family == AF_INET) { 1585 struct fib_nh *nh; 1586 1587 nh = container_of(nhc, struct fib_nh, nh_common); 1588 rt->dst.tclassid = nh->nh_tclassid; 1589 } 1590 #endif 1591 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1592 if (unlikely(fnhe)) 1593 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1594 else if (do_cache) 1595 cached = rt_cache_route(nhc, rt); 1596 if (unlikely(!cached)) { 1597 /* Routes we intend to cache in nexthop exception or 1598 * FIB nexthop have the DST_NOCACHE bit clear. 1599 * However, if we are unsuccessful at storing this 1600 * route into the cache we really need to set it. 1601 */ 1602 if (!rt->rt_gw4) { 1603 rt->rt_gw_family = AF_INET; 1604 rt->rt_gw4 = daddr; 1605 } 1606 rt_add_uncached_list(rt); 1607 } 1608 } else 1609 rt_add_uncached_list(rt); 1610 1611 #ifdef CONFIG_IP_ROUTE_CLASSID 1612 #ifdef CONFIG_IP_MULTIPLE_TABLES 1613 set_class_tag(rt, res->tclassid); 1614 #endif 1615 set_class_tag(rt, itag); 1616 #endif 1617 } 1618 1619 struct rtable *rt_dst_alloc(struct net_device *dev, 1620 unsigned int flags, u16 type, 1621 bool noxfrm) 1622 { 1623 struct rtable *rt; 1624 1625 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1626 (noxfrm ? DST_NOXFRM : 0)); 1627 1628 if (rt) { 1629 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1630 rt->rt_flags = flags; 1631 rt->rt_type = type; 1632 rt->rt_is_input = 0; 1633 rt->rt_iif = 0; 1634 rt->rt_pmtu = 0; 1635 rt->rt_mtu_locked = 0; 1636 rt->rt_uses_gateway = 0; 1637 rt->rt_gw_family = 0; 1638 rt->rt_gw4 = 0; 1639 1640 rt->dst.output = ip_output; 1641 if (flags & RTCF_LOCAL) 1642 rt->dst.input = ip_local_deliver; 1643 } 1644 1645 return rt; 1646 } 1647 EXPORT_SYMBOL(rt_dst_alloc); 1648 1649 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1650 { 1651 struct rtable *new_rt; 1652 1653 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1654 rt->dst.flags); 1655 1656 if (new_rt) { 1657 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1658 new_rt->rt_flags = rt->rt_flags; 1659 new_rt->rt_type = rt->rt_type; 1660 new_rt->rt_is_input = rt->rt_is_input; 1661 new_rt->rt_iif = rt->rt_iif; 1662 new_rt->rt_pmtu = rt->rt_pmtu; 1663 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1664 new_rt->rt_gw_family = rt->rt_gw_family; 1665 if (rt->rt_gw_family == AF_INET) 1666 new_rt->rt_gw4 = rt->rt_gw4; 1667 else if (rt->rt_gw_family == AF_INET6) 1668 new_rt->rt_gw6 = rt->rt_gw6; 1669 1670 new_rt->dst.input = rt->dst.input; 1671 new_rt->dst.output = rt->dst.output; 1672 new_rt->dst.error = rt->dst.error; 1673 new_rt->dst.lastuse = jiffies; 1674 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1675 } 1676 return new_rt; 1677 } 1678 EXPORT_SYMBOL(rt_dst_clone); 1679 1680 /* called in rcu_read_lock() section */ 1681 enum skb_drop_reason 1682 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1683 dscp_t dscp, struct net_device *dev, 1684 struct in_device *in_dev, u32 *itag) 1685 { 1686 enum skb_drop_reason reason; 1687 1688 /* Primary sanity checks. */ 1689 if (!in_dev) 1690 return SKB_DROP_REASON_NOT_SPECIFIED; 1691 1692 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1693 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1694 1695 if (skb->protocol != htons(ETH_P_IP)) 1696 return SKB_DROP_REASON_INVALID_PROTO; 1697 1698 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1699 return SKB_DROP_REASON_IP_LOCALNET; 1700 1701 if (ipv4_is_zeronet(saddr)) { 1702 if (!ipv4_is_local_multicast(daddr) && 1703 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1704 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1705 } else { 1706 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1707 dev, in_dev, itag); 1708 if (reason) 1709 return reason; 1710 } 1711 return SKB_NOT_DROPPED_YET; 1712 } 1713 1714 /* called in rcu_read_lock() section */ 1715 static enum skb_drop_reason 1716 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1717 dscp_t dscp, struct net_device *dev, int our) 1718 { 1719 struct in_device *in_dev = __in_dev_get_rcu(dev); 1720 unsigned int flags = RTCF_MULTICAST; 1721 enum skb_drop_reason reason; 1722 struct rtable *rth; 1723 u32 itag = 0; 1724 1725 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1726 &itag); 1727 if (reason) 1728 return reason; 1729 1730 if (our) 1731 flags |= RTCF_LOCAL; 1732 1733 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1734 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1735 1736 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1737 false); 1738 if (!rth) 1739 return SKB_DROP_REASON_NOMEM; 1740 1741 #ifdef CONFIG_IP_ROUTE_CLASSID 1742 rth->dst.tclassid = itag; 1743 #endif 1744 rth->dst.output = ip_rt_bug; 1745 rth->rt_is_input= 1; 1746 1747 #ifdef CONFIG_IP_MROUTE 1748 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1749 rth->dst.input = ip_mr_input; 1750 #endif 1751 RT_CACHE_STAT_INC(in_slow_mc); 1752 1753 skb_dst_drop(skb); 1754 skb_dst_set(skb, &rth->dst); 1755 return SKB_NOT_DROPPED_YET; 1756 } 1757 1758 1759 static void ip_handle_martian_source(struct net_device *dev, 1760 struct in_device *in_dev, 1761 struct sk_buff *skb, 1762 __be32 daddr, 1763 __be32 saddr) 1764 { 1765 RT_CACHE_STAT_INC(in_martian_src); 1766 #ifdef CONFIG_IP_ROUTE_VERBOSE 1767 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1768 /* 1769 * RFC1812 recommendation, if source is martian, 1770 * the only hint is MAC header. 1771 */ 1772 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1773 &daddr, &saddr, dev->name); 1774 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1775 print_hex_dump(KERN_WARNING, "ll header: ", 1776 DUMP_PREFIX_OFFSET, 16, 1, 1777 skb_mac_header(skb), 1778 dev->hard_header_len, false); 1779 } 1780 } 1781 #endif 1782 } 1783 1784 /* called in rcu_read_lock() section */ 1785 static enum skb_drop_reason 1786 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1787 struct in_device *in_dev, __be32 daddr, 1788 __be32 saddr, dscp_t dscp) 1789 { 1790 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1791 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1792 struct net_device *dev = nhc->nhc_dev; 1793 struct fib_nh_exception *fnhe; 1794 struct rtable *rth; 1795 int err; 1796 struct in_device *out_dev; 1797 bool do_cache; 1798 u32 itag = 0; 1799 1800 /* get a working reference to the output device */ 1801 out_dev = __in_dev_get_rcu(dev); 1802 if (!out_dev) { 1803 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1804 return reason; 1805 } 1806 1807 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1808 in_dev->dev, in_dev, &itag); 1809 if (err < 0) { 1810 reason = -err; 1811 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1812 saddr); 1813 1814 goto cleanup; 1815 } 1816 1817 do_cache = res->fi && !itag; 1818 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1819 skb->protocol == htons(ETH_P_IP)) { 1820 __be32 gw; 1821 1822 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1823 if (IN_DEV_SHARED_MEDIA(out_dev) || 1824 inet_addr_onlink(out_dev, saddr, gw)) 1825 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1826 } 1827 1828 if (skb->protocol != htons(ETH_P_IP)) { 1829 /* Not IP (i.e. ARP). Do not create route, if it is 1830 * invalid for proxy arp. DNAT routes are always valid. 1831 * 1832 * Proxy arp feature have been extended to allow, ARP 1833 * replies back to the same interface, to support 1834 * Private VLAN switch technologies. See arp.c. 1835 */ 1836 if (out_dev == in_dev && 1837 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1838 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1839 goto cleanup; 1840 } 1841 } 1842 1843 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1844 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1845 1846 fnhe = find_exception(nhc, daddr); 1847 if (do_cache) { 1848 if (fnhe) 1849 rth = rcu_dereference(fnhe->fnhe_rth_input); 1850 else 1851 rth = rcu_dereference(nhc->nhc_rth_input); 1852 if (rt_cache_valid(rth)) { 1853 skb_dst_set_noref(skb, &rth->dst); 1854 goto out; 1855 } 1856 } 1857 1858 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1859 IN_DEV_ORCONF(out_dev, NOXFRM)); 1860 if (!rth) { 1861 reason = SKB_DROP_REASON_NOMEM; 1862 goto cleanup; 1863 } 1864 1865 rth->rt_is_input = 1; 1866 RT_CACHE_STAT_INC(in_slow_tot); 1867 1868 rth->dst.input = ip_forward; 1869 1870 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1871 do_cache); 1872 lwtunnel_set_redirect(&rth->dst); 1873 skb_dst_set(skb, &rth->dst); 1874 out: 1875 reason = SKB_NOT_DROPPED_YET; 1876 cleanup: 1877 return reason; 1878 } 1879 1880 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1881 /* To make ICMP packets follow the right flow, the multipath hash is 1882 * calculated from the inner IP addresses. 1883 */ 1884 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1885 struct flow_keys *hash_keys) 1886 { 1887 const struct iphdr *outer_iph = ip_hdr(skb); 1888 const struct iphdr *key_iph = outer_iph; 1889 const struct iphdr *inner_iph; 1890 const struct icmphdr *icmph; 1891 struct iphdr _inner_iph; 1892 struct icmphdr _icmph; 1893 1894 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1895 goto out; 1896 1897 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1898 goto out; 1899 1900 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1901 &_icmph); 1902 if (!icmph) 1903 goto out; 1904 1905 if (!icmp_is_err(icmph->type)) 1906 goto out; 1907 1908 inner_iph = skb_header_pointer(skb, 1909 outer_iph->ihl * 4 + sizeof(_icmph), 1910 sizeof(_inner_iph), &_inner_iph); 1911 if (!inner_iph) 1912 goto out; 1913 1914 key_iph = inner_iph; 1915 out: 1916 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1917 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1918 } 1919 1920 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1921 const struct sk_buff *skb, 1922 bool *p_has_inner) 1923 { 1924 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1925 struct flow_keys keys, hash_keys; 1926 1927 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1928 return 0; 1929 1930 memset(&hash_keys, 0, sizeof(hash_keys)); 1931 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1932 1933 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1934 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1935 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1936 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1937 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1938 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1939 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1940 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1941 hash_keys.ports.src = keys.ports.src; 1942 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1943 hash_keys.ports.dst = keys.ports.dst; 1944 1945 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1946 return fib_multipath_hash_from_keys(net, &hash_keys); 1947 } 1948 1949 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1950 const struct sk_buff *skb, 1951 bool has_inner) 1952 { 1953 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1954 struct flow_keys keys, hash_keys; 1955 1956 /* We assume the packet carries an encapsulation, but if none was 1957 * encountered during dissection of the outer flow, then there is no 1958 * point in calling the flow dissector again. 1959 */ 1960 if (!has_inner) 1961 return 0; 1962 1963 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1964 return 0; 1965 1966 memset(&hash_keys, 0, sizeof(hash_keys)); 1967 skb_flow_dissect_flow_keys(skb, &keys, 0); 1968 1969 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1970 return 0; 1971 1972 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1973 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1974 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1975 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1976 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1977 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1978 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1979 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1980 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1981 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 1982 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1983 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 1984 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 1985 hash_keys.tags.flow_label = keys.tags.flow_label; 1986 } 1987 1988 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 1989 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1990 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 1991 hash_keys.ports.src = keys.ports.src; 1992 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 1993 hash_keys.ports.dst = keys.ports.dst; 1994 1995 return fib_multipath_hash_from_keys(net, &hash_keys); 1996 } 1997 1998 static u32 fib_multipath_custom_hash_skb(const struct net *net, 1999 const struct sk_buff *skb) 2000 { 2001 u32 mhash, mhash_inner; 2002 bool has_inner = true; 2003 2004 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2005 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2006 2007 return jhash_2words(mhash, mhash_inner, 0); 2008 } 2009 2010 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2011 const struct flowi4 *fl4) 2012 { 2013 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2014 struct flow_keys hash_keys; 2015 2016 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2017 return 0; 2018 2019 memset(&hash_keys, 0, sizeof(hash_keys)); 2020 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2021 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2022 hash_keys.addrs.v4addrs.src = fl4->saddr; 2023 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2024 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2025 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2026 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2027 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2028 hash_keys.ports.src = fl4->fl4_sport; 2029 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2030 hash_keys.ports.dst = fl4->fl4_dport; 2031 2032 return fib_multipath_hash_from_keys(net, &hash_keys); 2033 } 2034 2035 /* if skb is set it will be used and fl4 can be NULL */ 2036 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2037 const struct sk_buff *skb, struct flow_keys *flkeys) 2038 { 2039 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2040 struct flow_keys hash_keys; 2041 u32 mhash = 0; 2042 2043 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2044 case 0: 2045 memset(&hash_keys, 0, sizeof(hash_keys)); 2046 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2047 if (skb) { 2048 ip_multipath_l3_keys(skb, &hash_keys); 2049 } else { 2050 hash_keys.addrs.v4addrs.src = fl4->saddr; 2051 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2052 } 2053 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2054 break; 2055 case 1: 2056 /* skb is currently provided only when forwarding */ 2057 if (skb) { 2058 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2059 struct flow_keys keys; 2060 2061 /* short-circuit if we already have L4 hash present */ 2062 if (skb->l4_hash) 2063 return skb_get_hash_raw(skb) >> 1; 2064 2065 memset(&hash_keys, 0, sizeof(hash_keys)); 2066 2067 if (!flkeys) { 2068 skb_flow_dissect_flow_keys(skb, &keys, flag); 2069 flkeys = &keys; 2070 } 2071 2072 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2073 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2074 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2075 hash_keys.ports.src = flkeys->ports.src; 2076 hash_keys.ports.dst = flkeys->ports.dst; 2077 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2078 } else { 2079 memset(&hash_keys, 0, sizeof(hash_keys)); 2080 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2081 hash_keys.addrs.v4addrs.src = fl4->saddr; 2082 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2083 hash_keys.ports.src = fl4->fl4_sport; 2084 hash_keys.ports.dst = fl4->fl4_dport; 2085 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2086 } 2087 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2088 break; 2089 case 2: 2090 memset(&hash_keys, 0, sizeof(hash_keys)); 2091 /* skb is currently provided only when forwarding */ 2092 if (skb) { 2093 struct flow_keys keys; 2094 2095 skb_flow_dissect_flow_keys(skb, &keys, 0); 2096 /* Inner can be v4 or v6 */ 2097 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2098 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2099 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2100 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2101 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2102 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2103 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2104 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2105 hash_keys.tags.flow_label = keys.tags.flow_label; 2106 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2107 } else { 2108 /* Same as case 0 */ 2109 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2110 ip_multipath_l3_keys(skb, &hash_keys); 2111 } 2112 } else { 2113 /* Same as case 0 */ 2114 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2115 hash_keys.addrs.v4addrs.src = fl4->saddr; 2116 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2117 } 2118 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2119 break; 2120 case 3: 2121 if (skb) 2122 mhash = fib_multipath_custom_hash_skb(net, skb); 2123 else 2124 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2125 break; 2126 } 2127 2128 if (multipath_hash) 2129 mhash = jhash_2words(mhash, multipath_hash, 0); 2130 2131 return mhash >> 1; 2132 } 2133 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2134 2135 static enum skb_drop_reason 2136 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2137 struct in_device *in_dev, __be32 daddr, 2138 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2139 { 2140 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2141 if (res->fi && fib_info_num_path(res->fi) > 1) { 2142 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2143 2144 fib_select_multipath(res, h); 2145 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2146 } 2147 #endif 2148 2149 /* create a routing cache entry */ 2150 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2151 } 2152 2153 /* Implements all the saddr-related checks as ip_route_input_slow(), 2154 * assuming daddr is valid and the destination is not a local broadcast one. 2155 * Uses the provided hint instead of performing a route lookup. 2156 */ 2157 enum skb_drop_reason 2158 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2159 dscp_t dscp, struct net_device *dev, 2160 const struct sk_buff *hint) 2161 { 2162 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2163 struct in_device *in_dev = __in_dev_get_rcu(dev); 2164 struct rtable *rt = skb_rtable(hint); 2165 struct net *net = dev_net(dev); 2166 u32 tag = 0; 2167 2168 if (!in_dev) 2169 return reason; 2170 2171 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2172 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2173 goto martian_source; 2174 } 2175 2176 if (ipv4_is_zeronet(saddr)) { 2177 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2178 goto martian_source; 2179 } 2180 2181 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2182 reason = SKB_DROP_REASON_IP_LOCALNET; 2183 goto martian_source; 2184 } 2185 2186 if (rt->rt_type != RTN_LOCAL) 2187 goto skip_validate_source; 2188 2189 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2190 in_dev, &tag); 2191 if (reason) 2192 goto martian_source; 2193 2194 skip_validate_source: 2195 skb_dst_copy(skb, hint); 2196 return SKB_NOT_DROPPED_YET; 2197 2198 martian_source: 2199 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2200 return reason; 2201 } 2202 2203 /* get device for dst_alloc with local routes */ 2204 static struct net_device *ip_rt_get_dev(struct net *net, 2205 const struct fib_result *res) 2206 { 2207 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2208 struct net_device *dev = NULL; 2209 2210 if (nhc) 2211 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2212 2213 return dev ? : net->loopback_dev; 2214 } 2215 2216 /* 2217 * NOTE. We drop all the packets that has local source 2218 * addresses, because every properly looped back packet 2219 * must have correct destination already attached by output routine. 2220 * Changes in the enforced policies must be applied also to 2221 * ip_route_use_hint(). 2222 * 2223 * Such approach solves two big problems: 2224 * 1. Not simplex devices are handled properly. 2225 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2226 * called with rcu_read_lock() 2227 */ 2228 2229 static enum skb_drop_reason 2230 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2231 dscp_t dscp, struct net_device *dev, 2232 struct fib_result *res) 2233 { 2234 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2235 struct in_device *in_dev = __in_dev_get_rcu(dev); 2236 struct flow_keys *flkeys = NULL, _flkeys; 2237 struct net *net = dev_net(dev); 2238 struct ip_tunnel_info *tun_info; 2239 int err = -EINVAL; 2240 unsigned int flags = 0; 2241 u32 itag = 0; 2242 struct rtable *rth; 2243 struct flowi4 fl4; 2244 bool do_cache = true; 2245 2246 /* IP on this device is disabled. */ 2247 2248 if (!in_dev) 2249 goto out; 2250 2251 /* Check for the most weird martians, which can be not detected 2252 * by fib_lookup. 2253 */ 2254 2255 tun_info = skb_tunnel_info(skb); 2256 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2257 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2258 else 2259 fl4.flowi4_tun_key.tun_id = 0; 2260 skb_dst_drop(skb); 2261 2262 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2263 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2264 goto martian_source; 2265 } 2266 2267 res->fi = NULL; 2268 res->table = NULL; 2269 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2270 goto brd_input; 2271 2272 /* Accept zero addresses only to limited broadcast; 2273 * I even do not know to fix it or not. Waiting for complains :-) 2274 */ 2275 if (ipv4_is_zeronet(saddr)) { 2276 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2277 goto martian_source; 2278 } 2279 2280 if (ipv4_is_zeronet(daddr)) { 2281 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2282 goto martian_destination; 2283 } 2284 2285 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2286 * and call it once if daddr or/and saddr are loopback addresses 2287 */ 2288 if (ipv4_is_loopback(daddr)) { 2289 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2290 reason = SKB_DROP_REASON_IP_LOCALNET; 2291 goto martian_destination; 2292 } 2293 } else if (ipv4_is_loopback(saddr)) { 2294 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2295 reason = SKB_DROP_REASON_IP_LOCALNET; 2296 goto martian_source; 2297 } 2298 } 2299 2300 /* 2301 * Now we are ready to route packet. 2302 */ 2303 fl4.flowi4_l3mdev = 0; 2304 fl4.flowi4_oif = 0; 2305 fl4.flowi4_iif = dev->ifindex; 2306 fl4.flowi4_mark = skb->mark; 2307 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp); 2308 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2309 fl4.flowi4_flags = 0; 2310 fl4.daddr = daddr; 2311 fl4.saddr = saddr; 2312 fl4.flowi4_uid = sock_net_uid(net, NULL); 2313 fl4.flowi4_multipath_hash = 0; 2314 2315 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2316 flkeys = &_flkeys; 2317 } else { 2318 fl4.flowi4_proto = 0; 2319 fl4.fl4_sport = 0; 2320 fl4.fl4_dport = 0; 2321 } 2322 2323 err = fib_lookup(net, &fl4, res, 0); 2324 if (err != 0) { 2325 if (!IN_DEV_FORWARD(in_dev)) 2326 err = -EHOSTUNREACH; 2327 goto no_route; 2328 } 2329 2330 if (res->type == RTN_BROADCAST) { 2331 if (IN_DEV_BFORWARD(in_dev)) 2332 goto make_route; 2333 /* not do cache if bc_forwarding is enabled */ 2334 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2335 do_cache = false; 2336 goto brd_input; 2337 } 2338 2339 err = -EINVAL; 2340 if (res->type == RTN_LOCAL) { 2341 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2342 0, dev, in_dev, &itag); 2343 if (reason) 2344 goto martian_source; 2345 goto local_input; 2346 } 2347 2348 if (!IN_DEV_FORWARD(in_dev)) { 2349 err = -EHOSTUNREACH; 2350 goto no_route; 2351 } 2352 if (res->type != RTN_UNICAST) { 2353 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2354 goto martian_destination; 2355 } 2356 2357 make_route: 2358 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2359 flkeys); 2360 2361 out: 2362 return reason; 2363 2364 brd_input: 2365 if (skb->protocol != htons(ETH_P_IP)) { 2366 reason = SKB_DROP_REASON_INVALID_PROTO; 2367 goto out; 2368 } 2369 2370 if (!ipv4_is_zeronet(saddr)) { 2371 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2372 dev, in_dev, &itag); 2373 if (reason) 2374 goto martian_source; 2375 } 2376 flags |= RTCF_BROADCAST; 2377 res->type = RTN_BROADCAST; 2378 RT_CACHE_STAT_INC(in_brd); 2379 2380 local_input: 2381 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2382 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2383 2384 do_cache &= res->fi && !itag; 2385 if (do_cache) { 2386 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2387 2388 rth = rcu_dereference(nhc->nhc_rth_input); 2389 if (rt_cache_valid(rth)) { 2390 skb_dst_set_noref(skb, &rth->dst); 2391 reason = SKB_NOT_DROPPED_YET; 2392 goto out; 2393 } 2394 } 2395 2396 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2397 flags | RTCF_LOCAL, res->type, false); 2398 if (!rth) 2399 goto e_nobufs; 2400 2401 rth->dst.output= ip_rt_bug; 2402 #ifdef CONFIG_IP_ROUTE_CLASSID 2403 rth->dst.tclassid = itag; 2404 #endif 2405 rth->rt_is_input = 1; 2406 2407 RT_CACHE_STAT_INC(in_slow_tot); 2408 if (res->type == RTN_UNREACHABLE) { 2409 rth->dst.input= ip_error; 2410 rth->dst.error= -err; 2411 rth->rt_flags &= ~RTCF_LOCAL; 2412 } 2413 2414 if (do_cache) { 2415 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2416 2417 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2418 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2419 WARN_ON(rth->dst.input == lwtunnel_input); 2420 rth->dst.lwtstate->orig_input = rth->dst.input; 2421 rth->dst.input = lwtunnel_input; 2422 } 2423 2424 if (unlikely(!rt_cache_route(nhc, rth))) 2425 rt_add_uncached_list(rth); 2426 } 2427 skb_dst_set(skb, &rth->dst); 2428 reason = SKB_NOT_DROPPED_YET; 2429 goto out; 2430 2431 no_route: 2432 RT_CACHE_STAT_INC(in_no_route); 2433 res->type = RTN_UNREACHABLE; 2434 res->fi = NULL; 2435 res->table = NULL; 2436 goto local_input; 2437 2438 /* 2439 * Do not cache martian addresses: they should be logged (RFC1812) 2440 */ 2441 martian_destination: 2442 RT_CACHE_STAT_INC(in_martian_dst); 2443 #ifdef CONFIG_IP_ROUTE_VERBOSE 2444 if (IN_DEV_LOG_MARTIANS(in_dev)) 2445 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2446 &daddr, &saddr, dev->name); 2447 #endif 2448 goto out; 2449 2450 e_nobufs: 2451 reason = SKB_DROP_REASON_NOMEM; 2452 goto out; 2453 2454 martian_source: 2455 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2456 goto out; 2457 } 2458 2459 /* called with rcu_read_lock held */ 2460 static enum skb_drop_reason 2461 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2462 dscp_t dscp, struct net_device *dev, 2463 struct fib_result *res) 2464 { 2465 /* Multicast recognition logic is moved from route cache to here. 2466 * The problem was that too many Ethernet cards have broken/missing 2467 * hardware multicast filters :-( As result the host on multicasting 2468 * network acquires a lot of useless route cache entries, sort of 2469 * SDR messages from all the world. Now we try to get rid of them. 2470 * Really, provided software IP multicast filter is organized 2471 * reasonably (at least, hashed), it does not result in a slowdown 2472 * comparing with route cache reject entries. 2473 * Note, that multicast routers are not affected, because 2474 * route cache entry is created eventually. 2475 */ 2476 if (ipv4_is_multicast(daddr)) { 2477 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2478 struct in_device *in_dev = __in_dev_get_rcu(dev); 2479 int our = 0; 2480 2481 if (!in_dev) 2482 return reason; 2483 2484 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2485 ip_hdr(skb)->protocol); 2486 2487 /* check l3 master if no match yet */ 2488 if (!our && netif_is_l3_slave(dev)) { 2489 struct in_device *l3_in_dev; 2490 2491 l3_in_dev = __in_dev_get_rcu(skb->dev); 2492 if (l3_in_dev) 2493 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2494 ip_hdr(skb)->protocol); 2495 } 2496 2497 if (our 2498 #ifdef CONFIG_IP_MROUTE 2499 || 2500 (!ipv4_is_local_multicast(daddr) && 2501 IN_DEV_MFORWARD(in_dev)) 2502 #endif 2503 ) { 2504 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2505 dev, our); 2506 } 2507 return reason; 2508 } 2509 2510 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2511 } 2512 2513 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2514 __be32 saddr, dscp_t dscp, 2515 struct net_device *dev) 2516 { 2517 enum skb_drop_reason reason; 2518 struct fib_result res; 2519 2520 rcu_read_lock(); 2521 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2522 rcu_read_unlock(); 2523 2524 return reason; 2525 } 2526 EXPORT_SYMBOL(ip_route_input_noref); 2527 2528 /* called with rcu_read_lock() */ 2529 static struct rtable *__mkroute_output(const struct fib_result *res, 2530 const struct flowi4 *fl4, int orig_oif, 2531 struct net_device *dev_out, 2532 unsigned int flags) 2533 { 2534 struct fib_info *fi = res->fi; 2535 struct fib_nh_exception *fnhe; 2536 struct in_device *in_dev; 2537 u16 type = res->type; 2538 struct rtable *rth; 2539 bool do_cache; 2540 2541 in_dev = __in_dev_get_rcu(dev_out); 2542 if (!in_dev) 2543 return ERR_PTR(-EINVAL); 2544 2545 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2546 if (ipv4_is_loopback(fl4->saddr) && 2547 !(dev_out->flags & IFF_LOOPBACK) && 2548 !netif_is_l3_master(dev_out)) 2549 return ERR_PTR(-EINVAL); 2550 2551 if (ipv4_is_lbcast(fl4->daddr)) 2552 type = RTN_BROADCAST; 2553 else if (ipv4_is_multicast(fl4->daddr)) 2554 type = RTN_MULTICAST; 2555 else if (ipv4_is_zeronet(fl4->daddr)) 2556 return ERR_PTR(-EINVAL); 2557 2558 if (dev_out->flags & IFF_LOOPBACK) 2559 flags |= RTCF_LOCAL; 2560 2561 do_cache = true; 2562 if (type == RTN_BROADCAST) { 2563 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2564 fi = NULL; 2565 } else if (type == RTN_MULTICAST) { 2566 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2567 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2568 fl4->flowi4_proto)) 2569 flags &= ~RTCF_LOCAL; 2570 else 2571 do_cache = false; 2572 /* If multicast route do not exist use 2573 * default one, but do not gateway in this case. 2574 * Yes, it is hack. 2575 */ 2576 if (fi && res->prefixlen < 4) 2577 fi = NULL; 2578 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2579 (orig_oif != dev_out->ifindex)) { 2580 /* For local routes that require a particular output interface 2581 * we do not want to cache the result. Caching the result 2582 * causes incorrect behaviour when there are multiple source 2583 * addresses on the interface, the end result being that if the 2584 * intended recipient is waiting on that interface for the 2585 * packet he won't receive it because it will be delivered on 2586 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2587 * be set to the loopback interface as well. 2588 */ 2589 do_cache = false; 2590 } 2591 2592 fnhe = NULL; 2593 do_cache &= fi != NULL; 2594 if (fi) { 2595 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2596 struct rtable __rcu **prth; 2597 2598 fnhe = find_exception(nhc, fl4->daddr); 2599 if (!do_cache) 2600 goto add; 2601 if (fnhe) { 2602 prth = &fnhe->fnhe_rth_output; 2603 } else { 2604 if (unlikely(fl4->flowi4_flags & 2605 FLOWI_FLAG_KNOWN_NH && 2606 !(nhc->nhc_gw_family && 2607 nhc->nhc_scope == RT_SCOPE_LINK))) { 2608 do_cache = false; 2609 goto add; 2610 } 2611 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2612 } 2613 rth = rcu_dereference(*prth); 2614 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2615 return rth; 2616 } 2617 2618 add: 2619 rth = rt_dst_alloc(dev_out, flags, type, 2620 IN_DEV_ORCONF(in_dev, NOXFRM)); 2621 if (!rth) 2622 return ERR_PTR(-ENOBUFS); 2623 2624 rth->rt_iif = orig_oif; 2625 2626 RT_CACHE_STAT_INC(out_slow_tot); 2627 2628 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2629 if (flags & RTCF_LOCAL && 2630 !(dev_out->flags & IFF_LOOPBACK)) { 2631 rth->dst.output = ip_mc_output; 2632 RT_CACHE_STAT_INC(out_slow_mc); 2633 } 2634 #ifdef CONFIG_IP_MROUTE 2635 if (type == RTN_MULTICAST) { 2636 if (IN_DEV_MFORWARD(in_dev) && 2637 !ipv4_is_local_multicast(fl4->daddr)) { 2638 rth->dst.input = ip_mr_input; 2639 rth->dst.output = ip_mc_output; 2640 } 2641 } 2642 #endif 2643 } 2644 2645 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2646 lwtunnel_set_redirect(&rth->dst); 2647 2648 return rth; 2649 } 2650 2651 /* 2652 * Major route resolver routine. 2653 */ 2654 2655 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2656 const struct sk_buff *skb) 2657 { 2658 struct fib_result res = { 2659 .type = RTN_UNSPEC, 2660 .fi = NULL, 2661 .table = NULL, 2662 .tclassid = 0, 2663 }; 2664 struct rtable *rth; 2665 2666 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2667 fl4->flowi4_tos &= INET_DSCP_MASK; 2668 2669 rcu_read_lock(); 2670 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2671 rcu_read_unlock(); 2672 2673 return rth; 2674 } 2675 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2676 2677 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2678 struct fib_result *res, 2679 const struct sk_buff *skb) 2680 { 2681 struct net_device *dev_out = NULL; 2682 int orig_oif = fl4->flowi4_oif; 2683 unsigned int flags = 0; 2684 struct rtable *rth; 2685 int err; 2686 2687 if (fl4->saddr) { 2688 if (ipv4_is_multicast(fl4->saddr) || 2689 ipv4_is_lbcast(fl4->saddr) || 2690 ipv4_is_zeronet(fl4->saddr)) { 2691 rth = ERR_PTR(-EINVAL); 2692 goto out; 2693 } 2694 2695 rth = ERR_PTR(-ENETUNREACH); 2696 2697 /* I removed check for oif == dev_out->oif here. 2698 * It was wrong for two reasons: 2699 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2700 * is assigned to multiple interfaces. 2701 * 2. Moreover, we are allowed to send packets with saddr 2702 * of another iface. --ANK 2703 */ 2704 2705 if (fl4->flowi4_oif == 0 && 2706 (ipv4_is_multicast(fl4->daddr) || 2707 ipv4_is_lbcast(fl4->daddr))) { 2708 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2709 dev_out = __ip_dev_find(net, fl4->saddr, false); 2710 if (!dev_out) 2711 goto out; 2712 2713 /* Special hack: user can direct multicasts 2714 * and limited broadcast via necessary interface 2715 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2716 * This hack is not just for fun, it allows 2717 * vic,vat and friends to work. 2718 * They bind socket to loopback, set ttl to zero 2719 * and expect that it will work. 2720 * From the viewpoint of routing cache they are broken, 2721 * because we are not allowed to build multicast path 2722 * with loopback source addr (look, routing cache 2723 * cannot know, that ttl is zero, so that packet 2724 * will not leave this host and route is valid). 2725 * Luckily, this hack is good workaround. 2726 */ 2727 2728 fl4->flowi4_oif = dev_out->ifindex; 2729 goto make_route; 2730 } 2731 2732 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2733 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2734 if (!__ip_dev_find(net, fl4->saddr, false)) 2735 goto out; 2736 } 2737 } 2738 2739 2740 if (fl4->flowi4_oif) { 2741 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2742 rth = ERR_PTR(-ENODEV); 2743 if (!dev_out) 2744 goto out; 2745 2746 /* RACE: Check return value of inet_select_addr instead. */ 2747 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2748 rth = ERR_PTR(-ENETUNREACH); 2749 goto out; 2750 } 2751 if (ipv4_is_local_multicast(fl4->daddr) || 2752 ipv4_is_lbcast(fl4->daddr) || 2753 fl4->flowi4_proto == IPPROTO_IGMP) { 2754 if (!fl4->saddr) 2755 fl4->saddr = inet_select_addr(dev_out, 0, 2756 RT_SCOPE_LINK); 2757 goto make_route; 2758 } 2759 if (!fl4->saddr) { 2760 if (ipv4_is_multicast(fl4->daddr)) 2761 fl4->saddr = inet_select_addr(dev_out, 0, 2762 fl4->flowi4_scope); 2763 else if (!fl4->daddr) 2764 fl4->saddr = inet_select_addr(dev_out, 0, 2765 RT_SCOPE_HOST); 2766 } 2767 } 2768 2769 if (!fl4->daddr) { 2770 fl4->daddr = fl4->saddr; 2771 if (!fl4->daddr) 2772 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2773 dev_out = net->loopback_dev; 2774 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2775 res->type = RTN_LOCAL; 2776 flags |= RTCF_LOCAL; 2777 goto make_route; 2778 } 2779 2780 err = fib_lookup(net, fl4, res, 0); 2781 if (err) { 2782 res->fi = NULL; 2783 res->table = NULL; 2784 if (fl4->flowi4_oif && 2785 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2786 /* Apparently, routing tables are wrong. Assume, 2787 * that the destination is on link. 2788 * 2789 * WHY? DW. 2790 * Because we are allowed to send to iface 2791 * even if it has NO routes and NO assigned 2792 * addresses. When oif is specified, routing 2793 * tables are looked up with only one purpose: 2794 * to catch if destination is gatewayed, rather than 2795 * direct. Moreover, if MSG_DONTROUTE is set, 2796 * we send packet, ignoring both routing tables 2797 * and ifaddr state. --ANK 2798 * 2799 * 2800 * We could make it even if oif is unknown, 2801 * likely IPv6, but we do not. 2802 */ 2803 2804 if (fl4->saddr == 0) 2805 fl4->saddr = inet_select_addr(dev_out, 0, 2806 RT_SCOPE_LINK); 2807 res->type = RTN_UNICAST; 2808 goto make_route; 2809 } 2810 rth = ERR_PTR(err); 2811 goto out; 2812 } 2813 2814 if (res->type == RTN_LOCAL) { 2815 if (!fl4->saddr) { 2816 if (res->fi->fib_prefsrc) 2817 fl4->saddr = res->fi->fib_prefsrc; 2818 else 2819 fl4->saddr = fl4->daddr; 2820 } 2821 2822 /* L3 master device is the loopback for that domain */ 2823 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2824 net->loopback_dev; 2825 2826 /* make sure orig_oif points to fib result device even 2827 * though packet rx/tx happens over loopback or l3mdev 2828 */ 2829 orig_oif = FIB_RES_OIF(*res); 2830 2831 fl4->flowi4_oif = dev_out->ifindex; 2832 flags |= RTCF_LOCAL; 2833 goto make_route; 2834 } 2835 2836 fib_select_path(net, res, fl4, skb); 2837 2838 dev_out = FIB_RES_DEV(*res); 2839 2840 make_route: 2841 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2842 2843 out: 2844 return rth; 2845 } 2846 2847 static struct dst_ops ipv4_dst_blackhole_ops = { 2848 .family = AF_INET, 2849 .default_advmss = ipv4_default_advmss, 2850 .neigh_lookup = ipv4_neigh_lookup, 2851 .check = dst_blackhole_check, 2852 .cow_metrics = dst_blackhole_cow_metrics, 2853 .update_pmtu = dst_blackhole_update_pmtu, 2854 .redirect = dst_blackhole_redirect, 2855 .mtu = dst_blackhole_mtu, 2856 }; 2857 2858 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2859 { 2860 struct rtable *ort = dst_rtable(dst_orig); 2861 struct rtable *rt; 2862 2863 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2864 if (rt) { 2865 struct dst_entry *new = &rt->dst; 2866 2867 new->__use = 1; 2868 new->input = dst_discard; 2869 new->output = dst_discard_out; 2870 2871 new->dev = net->loopback_dev; 2872 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2873 2874 rt->rt_is_input = ort->rt_is_input; 2875 rt->rt_iif = ort->rt_iif; 2876 rt->rt_pmtu = ort->rt_pmtu; 2877 rt->rt_mtu_locked = ort->rt_mtu_locked; 2878 2879 rt->rt_genid = rt_genid_ipv4(net); 2880 rt->rt_flags = ort->rt_flags; 2881 rt->rt_type = ort->rt_type; 2882 rt->rt_uses_gateway = ort->rt_uses_gateway; 2883 rt->rt_gw_family = ort->rt_gw_family; 2884 if (rt->rt_gw_family == AF_INET) 2885 rt->rt_gw4 = ort->rt_gw4; 2886 else if (rt->rt_gw_family == AF_INET6) 2887 rt->rt_gw6 = ort->rt_gw6; 2888 } 2889 2890 dst_release(dst_orig); 2891 2892 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2893 } 2894 2895 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2896 const struct sock *sk) 2897 { 2898 struct rtable *rt = __ip_route_output_key(net, flp4); 2899 2900 if (IS_ERR(rt)) 2901 return rt; 2902 2903 if (flp4->flowi4_proto) { 2904 flp4->flowi4_oif = rt->dst.dev->ifindex; 2905 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2906 flowi4_to_flowi(flp4), 2907 sk, 0)); 2908 } 2909 2910 return rt; 2911 } 2912 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2913 2914 /* called with rcu_read_lock held */ 2915 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2916 struct rtable *rt, u32 table_id, dscp_t dscp, 2917 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2918 u32 seq, unsigned int flags) 2919 { 2920 struct rtmsg *r; 2921 struct nlmsghdr *nlh; 2922 unsigned long expires = 0; 2923 u32 error; 2924 u32 metrics[RTAX_MAX]; 2925 2926 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2927 if (!nlh) 2928 return -EMSGSIZE; 2929 2930 r = nlmsg_data(nlh); 2931 r->rtm_family = AF_INET; 2932 r->rtm_dst_len = 32; 2933 r->rtm_src_len = 0; 2934 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2935 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2936 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2937 goto nla_put_failure; 2938 r->rtm_type = rt->rt_type; 2939 r->rtm_scope = RT_SCOPE_UNIVERSE; 2940 r->rtm_protocol = RTPROT_UNSPEC; 2941 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2942 if (rt->rt_flags & RTCF_NOTIFY) 2943 r->rtm_flags |= RTM_F_NOTIFY; 2944 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2945 r->rtm_flags |= RTCF_DOREDIRECT; 2946 2947 if (nla_put_in_addr(skb, RTA_DST, dst)) 2948 goto nla_put_failure; 2949 if (src) { 2950 r->rtm_src_len = 32; 2951 if (nla_put_in_addr(skb, RTA_SRC, src)) 2952 goto nla_put_failure; 2953 } 2954 if (rt->dst.dev && 2955 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2956 goto nla_put_failure; 2957 if (rt->dst.lwtstate && 2958 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2959 goto nla_put_failure; 2960 #ifdef CONFIG_IP_ROUTE_CLASSID 2961 if (rt->dst.tclassid && 2962 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2963 goto nla_put_failure; 2964 #endif 2965 if (fl4 && !rt_is_input_route(rt) && 2966 fl4->saddr != src) { 2967 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2968 goto nla_put_failure; 2969 } 2970 if (rt->rt_uses_gateway) { 2971 if (rt->rt_gw_family == AF_INET && 2972 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2973 goto nla_put_failure; 2974 } else if (rt->rt_gw_family == AF_INET6) { 2975 int alen = sizeof(struct in6_addr); 2976 struct nlattr *nla; 2977 struct rtvia *via; 2978 2979 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2980 if (!nla) 2981 goto nla_put_failure; 2982 2983 via = nla_data(nla); 2984 via->rtvia_family = AF_INET6; 2985 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2986 } 2987 } 2988 2989 expires = rt->dst.expires; 2990 if (expires) { 2991 unsigned long now = jiffies; 2992 2993 if (time_before(now, expires)) 2994 expires -= now; 2995 else 2996 expires = 0; 2997 } 2998 2999 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3000 if (rt->rt_pmtu && expires) 3001 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3002 if (rt->rt_mtu_locked && expires) 3003 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3004 if (rtnetlink_put_metrics(skb, metrics) < 0) 3005 goto nla_put_failure; 3006 3007 if (fl4) { 3008 if (fl4->flowi4_mark && 3009 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3010 goto nla_put_failure; 3011 3012 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3013 nla_put_u32(skb, RTA_UID, 3014 from_kuid_munged(current_user_ns(), 3015 fl4->flowi4_uid))) 3016 goto nla_put_failure; 3017 3018 if (rt_is_input_route(rt)) { 3019 #ifdef CONFIG_IP_MROUTE 3020 if (ipv4_is_multicast(dst) && 3021 !ipv4_is_local_multicast(dst) && 3022 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3023 int err = ipmr_get_route(net, skb, 3024 fl4->saddr, fl4->daddr, 3025 r, portid); 3026 3027 if (err <= 0) { 3028 if (err == 0) 3029 return 0; 3030 goto nla_put_failure; 3031 } 3032 } else 3033 #endif 3034 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3035 goto nla_put_failure; 3036 } 3037 } 3038 3039 error = rt->dst.error; 3040 3041 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3042 goto nla_put_failure; 3043 3044 nlmsg_end(skb, nlh); 3045 return 0; 3046 3047 nla_put_failure: 3048 nlmsg_cancel(skb, nlh); 3049 return -EMSGSIZE; 3050 } 3051 3052 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3053 struct netlink_callback *cb, u32 table_id, 3054 struct fnhe_hash_bucket *bucket, int genid, 3055 int *fa_index, int fa_start, unsigned int flags) 3056 { 3057 int i; 3058 3059 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3060 struct fib_nh_exception *fnhe; 3061 3062 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3063 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3064 struct rtable *rt; 3065 int err; 3066 3067 if (*fa_index < fa_start) 3068 goto next; 3069 3070 if (fnhe->fnhe_genid != genid) 3071 goto next; 3072 3073 if (fnhe->fnhe_expires && 3074 time_after(jiffies, fnhe->fnhe_expires)) 3075 goto next; 3076 3077 rt = rcu_dereference(fnhe->fnhe_rth_input); 3078 if (!rt) 3079 rt = rcu_dereference(fnhe->fnhe_rth_output); 3080 if (!rt) 3081 goto next; 3082 3083 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3084 table_id, 0, NULL, skb, 3085 NETLINK_CB(cb->skb).portid, 3086 cb->nlh->nlmsg_seq, flags); 3087 if (err) 3088 return err; 3089 next: 3090 (*fa_index)++; 3091 } 3092 } 3093 3094 return 0; 3095 } 3096 3097 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3098 u32 table_id, struct fib_info *fi, 3099 int *fa_index, int fa_start, unsigned int flags) 3100 { 3101 struct net *net = sock_net(cb->skb->sk); 3102 int nhsel, genid = fnhe_genid(net); 3103 3104 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3105 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3106 struct fnhe_hash_bucket *bucket; 3107 int err; 3108 3109 if (nhc->nhc_flags & RTNH_F_DEAD) 3110 continue; 3111 3112 rcu_read_lock(); 3113 bucket = rcu_dereference(nhc->nhc_exceptions); 3114 err = 0; 3115 if (bucket) 3116 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3117 genid, fa_index, fa_start, 3118 flags); 3119 rcu_read_unlock(); 3120 if (err) 3121 return err; 3122 } 3123 3124 return 0; 3125 } 3126 3127 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3128 u8 ip_proto, __be16 sport, 3129 __be16 dport) 3130 { 3131 struct sk_buff *skb; 3132 struct iphdr *iph; 3133 3134 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3135 if (!skb) 3136 return NULL; 3137 3138 /* Reserve room for dummy headers, this skb can pass 3139 * through good chunk of routing engine. 3140 */ 3141 skb_reset_mac_header(skb); 3142 skb_reset_network_header(skb); 3143 skb->protocol = htons(ETH_P_IP); 3144 iph = skb_put(skb, sizeof(struct iphdr)); 3145 iph->protocol = ip_proto; 3146 iph->saddr = src; 3147 iph->daddr = dst; 3148 iph->version = 0x4; 3149 iph->frag_off = 0; 3150 iph->ihl = 0x5; 3151 skb_set_transport_header(skb, skb->len); 3152 3153 switch (iph->protocol) { 3154 case IPPROTO_UDP: { 3155 struct udphdr *udph; 3156 3157 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3158 udph->source = sport; 3159 udph->dest = dport; 3160 udph->len = htons(sizeof(struct udphdr)); 3161 udph->check = 0; 3162 break; 3163 } 3164 case IPPROTO_TCP: { 3165 struct tcphdr *tcph; 3166 3167 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3168 tcph->source = sport; 3169 tcph->dest = dport; 3170 tcph->doff = sizeof(struct tcphdr) / 4; 3171 tcph->rst = 1; 3172 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3173 src, dst, 0); 3174 break; 3175 } 3176 case IPPROTO_ICMP: { 3177 struct icmphdr *icmph; 3178 3179 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3180 icmph->type = ICMP_ECHO; 3181 icmph->code = 0; 3182 } 3183 } 3184 3185 return skb; 3186 } 3187 3188 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3189 const struct nlmsghdr *nlh, 3190 struct nlattr **tb, 3191 struct netlink_ext_ack *extack) 3192 { 3193 struct rtmsg *rtm; 3194 int i, err; 3195 3196 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 3197 NL_SET_ERR_MSG(extack, 3198 "ipv4: Invalid header for route get request"); 3199 return -EINVAL; 3200 } 3201 3202 if (!netlink_strict_get_check(skb)) 3203 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3204 rtm_ipv4_policy, extack); 3205 3206 rtm = nlmsg_data(nlh); 3207 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3208 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3209 rtm->rtm_table || rtm->rtm_protocol || 3210 rtm->rtm_scope || rtm->rtm_type) { 3211 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3212 return -EINVAL; 3213 } 3214 3215 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3216 RTM_F_LOOKUP_TABLE | 3217 RTM_F_FIB_MATCH)) { 3218 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3219 return -EINVAL; 3220 } 3221 3222 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3223 rtm_ipv4_policy, extack); 3224 if (err) 3225 return err; 3226 3227 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3228 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3229 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3230 return -EINVAL; 3231 } 3232 3233 for (i = 0; i <= RTA_MAX; i++) { 3234 if (!tb[i]) 3235 continue; 3236 3237 switch (i) { 3238 case RTA_IIF: 3239 case RTA_OIF: 3240 case RTA_SRC: 3241 case RTA_DST: 3242 case RTA_IP_PROTO: 3243 case RTA_SPORT: 3244 case RTA_DPORT: 3245 case RTA_MARK: 3246 case RTA_UID: 3247 break; 3248 default: 3249 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3250 return -EINVAL; 3251 } 3252 } 3253 3254 return 0; 3255 } 3256 3257 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3258 struct netlink_ext_ack *extack) 3259 { 3260 struct net *net = sock_net(in_skb->sk); 3261 struct nlattr *tb[RTA_MAX+1]; 3262 u32 table_id = RT_TABLE_MAIN; 3263 __be16 sport = 0, dport = 0; 3264 struct fib_result res = {}; 3265 u8 ip_proto = IPPROTO_UDP; 3266 struct rtable *rt = NULL; 3267 struct sk_buff *skb; 3268 struct rtmsg *rtm; 3269 struct flowi4 fl4 = {}; 3270 __be32 dst = 0; 3271 __be32 src = 0; 3272 kuid_t uid; 3273 u32 iif; 3274 int err; 3275 int mark; 3276 3277 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3278 if (err < 0) 3279 return err; 3280 3281 rtm = nlmsg_data(nlh); 3282 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3283 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3284 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3285 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3286 if (tb[RTA_UID]) 3287 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3288 else 3289 uid = (iif ? INVALID_UID : current_uid()); 3290 3291 if (tb[RTA_IP_PROTO]) { 3292 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3293 &ip_proto, AF_INET, extack); 3294 if (err) 3295 return err; 3296 } 3297 3298 if (tb[RTA_SPORT]) 3299 sport = nla_get_be16(tb[RTA_SPORT]); 3300 3301 if (tb[RTA_DPORT]) 3302 dport = nla_get_be16(tb[RTA_DPORT]); 3303 3304 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3305 if (!skb) 3306 return -ENOBUFS; 3307 3308 fl4.daddr = dst; 3309 fl4.saddr = src; 3310 fl4.flowi4_tos = rtm->rtm_tos & INET_DSCP_MASK; 3311 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3312 fl4.flowi4_mark = mark; 3313 fl4.flowi4_uid = uid; 3314 if (sport) 3315 fl4.fl4_sport = sport; 3316 if (dport) 3317 fl4.fl4_dport = dport; 3318 fl4.flowi4_proto = ip_proto; 3319 3320 rcu_read_lock(); 3321 3322 if (iif) { 3323 struct net_device *dev; 3324 3325 dev = dev_get_by_index_rcu(net, iif); 3326 if (!dev) { 3327 err = -ENODEV; 3328 goto errout_rcu; 3329 } 3330 3331 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3332 skb->dev = dev; 3333 skb->mark = mark; 3334 err = ip_route_input_rcu(skb, dst, src, 3335 inet_dsfield_to_dscp(rtm->rtm_tos), 3336 dev, &res) ? -EINVAL : 0; 3337 3338 rt = skb_rtable(skb); 3339 if (err == 0 && rt->dst.error) 3340 err = -rt->dst.error; 3341 } else { 3342 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3343 skb->dev = net->loopback_dev; 3344 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3345 err = 0; 3346 if (IS_ERR(rt)) 3347 err = PTR_ERR(rt); 3348 else 3349 skb_dst_set(skb, &rt->dst); 3350 } 3351 3352 if (err) 3353 goto errout_rcu; 3354 3355 if (rtm->rtm_flags & RTM_F_NOTIFY) 3356 rt->rt_flags |= RTCF_NOTIFY; 3357 3358 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3359 table_id = res.table ? res.table->tb_id : 0; 3360 3361 /* reset skb for netlink reply msg */ 3362 skb_trim(skb, 0); 3363 skb_reset_network_header(skb); 3364 skb_reset_transport_header(skb); 3365 skb_reset_mac_header(skb); 3366 3367 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3368 struct fib_rt_info fri; 3369 3370 if (!res.fi) { 3371 err = fib_props[res.type].error; 3372 if (!err) 3373 err = -EHOSTUNREACH; 3374 goto errout_rcu; 3375 } 3376 fri.fi = res.fi; 3377 fri.tb_id = table_id; 3378 fri.dst = res.prefix; 3379 fri.dst_len = res.prefixlen; 3380 fri.dscp = res.dscp; 3381 fri.type = rt->rt_type; 3382 fri.offload = 0; 3383 fri.trap = 0; 3384 fri.offload_failed = 0; 3385 if (res.fa_head) { 3386 struct fib_alias *fa; 3387 3388 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3389 u8 slen = 32 - fri.dst_len; 3390 3391 if (fa->fa_slen == slen && 3392 fa->tb_id == fri.tb_id && 3393 fa->fa_dscp == fri.dscp && 3394 fa->fa_info == res.fi && 3395 fa->fa_type == fri.type) { 3396 fri.offload = READ_ONCE(fa->offload); 3397 fri.trap = READ_ONCE(fa->trap); 3398 fri.offload_failed = 3399 READ_ONCE(fa->offload_failed); 3400 break; 3401 } 3402 } 3403 } 3404 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3405 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3406 } else { 3407 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3408 skb, NETLINK_CB(in_skb).portid, 3409 nlh->nlmsg_seq, 0); 3410 } 3411 if (err < 0) 3412 goto errout_rcu; 3413 3414 rcu_read_unlock(); 3415 3416 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3417 3418 errout_free: 3419 return err; 3420 errout_rcu: 3421 rcu_read_unlock(); 3422 kfree_skb(skb); 3423 goto errout_free; 3424 } 3425 3426 void ip_rt_multicast_event(struct in_device *in_dev) 3427 { 3428 rt_cache_flush(dev_net(in_dev->dev)); 3429 } 3430 3431 #ifdef CONFIG_SYSCTL 3432 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3433 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3434 static int ip_rt_gc_elasticity __read_mostly = 8; 3435 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3436 3437 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3438 void *buffer, size_t *lenp, loff_t *ppos) 3439 { 3440 struct net *net = (struct net *)__ctl->extra1; 3441 3442 if (write) { 3443 rt_cache_flush(net); 3444 fnhe_genid_bump(net); 3445 return 0; 3446 } 3447 3448 return -EINVAL; 3449 } 3450 3451 static struct ctl_table ipv4_route_table[] = { 3452 { 3453 .procname = "gc_thresh", 3454 .data = &ipv4_dst_ops.gc_thresh, 3455 .maxlen = sizeof(int), 3456 .mode = 0644, 3457 .proc_handler = proc_dointvec, 3458 }, 3459 { 3460 .procname = "max_size", 3461 .data = &ip_rt_max_size, 3462 .maxlen = sizeof(int), 3463 .mode = 0644, 3464 .proc_handler = proc_dointvec, 3465 }, 3466 { 3467 /* Deprecated. Use gc_min_interval_ms */ 3468 3469 .procname = "gc_min_interval", 3470 .data = &ip_rt_gc_min_interval, 3471 .maxlen = sizeof(int), 3472 .mode = 0644, 3473 .proc_handler = proc_dointvec_jiffies, 3474 }, 3475 { 3476 .procname = "gc_min_interval_ms", 3477 .data = &ip_rt_gc_min_interval, 3478 .maxlen = sizeof(int), 3479 .mode = 0644, 3480 .proc_handler = proc_dointvec_ms_jiffies, 3481 }, 3482 { 3483 .procname = "gc_timeout", 3484 .data = &ip_rt_gc_timeout, 3485 .maxlen = sizeof(int), 3486 .mode = 0644, 3487 .proc_handler = proc_dointvec_jiffies, 3488 }, 3489 { 3490 .procname = "gc_interval", 3491 .data = &ip_rt_gc_interval, 3492 .maxlen = sizeof(int), 3493 .mode = 0644, 3494 .proc_handler = proc_dointvec_jiffies, 3495 }, 3496 { 3497 .procname = "redirect_load", 3498 .data = &ip_rt_redirect_load, 3499 .maxlen = sizeof(int), 3500 .mode = 0644, 3501 .proc_handler = proc_dointvec, 3502 }, 3503 { 3504 .procname = "redirect_number", 3505 .data = &ip_rt_redirect_number, 3506 .maxlen = sizeof(int), 3507 .mode = 0644, 3508 .proc_handler = proc_dointvec, 3509 }, 3510 { 3511 .procname = "redirect_silence", 3512 .data = &ip_rt_redirect_silence, 3513 .maxlen = sizeof(int), 3514 .mode = 0644, 3515 .proc_handler = proc_dointvec, 3516 }, 3517 { 3518 .procname = "error_cost", 3519 .data = &ip_rt_error_cost, 3520 .maxlen = sizeof(int), 3521 .mode = 0644, 3522 .proc_handler = proc_dointvec, 3523 }, 3524 { 3525 .procname = "error_burst", 3526 .data = &ip_rt_error_burst, 3527 .maxlen = sizeof(int), 3528 .mode = 0644, 3529 .proc_handler = proc_dointvec, 3530 }, 3531 { 3532 .procname = "gc_elasticity", 3533 .data = &ip_rt_gc_elasticity, 3534 .maxlen = sizeof(int), 3535 .mode = 0644, 3536 .proc_handler = proc_dointvec, 3537 }, 3538 }; 3539 3540 static const char ipv4_route_flush_procname[] = "flush"; 3541 3542 static struct ctl_table ipv4_route_netns_table[] = { 3543 { 3544 .procname = ipv4_route_flush_procname, 3545 .maxlen = sizeof(int), 3546 .mode = 0200, 3547 .proc_handler = ipv4_sysctl_rtcache_flush, 3548 }, 3549 { 3550 .procname = "min_pmtu", 3551 .data = &init_net.ipv4.ip_rt_min_pmtu, 3552 .maxlen = sizeof(int), 3553 .mode = 0644, 3554 .proc_handler = proc_dointvec_minmax, 3555 .extra1 = &ip_min_valid_pmtu, 3556 }, 3557 { 3558 .procname = "mtu_expires", 3559 .data = &init_net.ipv4.ip_rt_mtu_expires, 3560 .maxlen = sizeof(int), 3561 .mode = 0644, 3562 .proc_handler = proc_dointvec_jiffies, 3563 }, 3564 { 3565 .procname = "min_adv_mss", 3566 .data = &init_net.ipv4.ip_rt_min_advmss, 3567 .maxlen = sizeof(int), 3568 .mode = 0644, 3569 .proc_handler = proc_dointvec, 3570 }, 3571 }; 3572 3573 static __net_init int sysctl_route_net_init(struct net *net) 3574 { 3575 struct ctl_table *tbl; 3576 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3577 3578 tbl = ipv4_route_netns_table; 3579 if (!net_eq(net, &init_net)) { 3580 int i; 3581 3582 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3583 if (!tbl) 3584 goto err_dup; 3585 3586 /* Don't export non-whitelisted sysctls to unprivileged users */ 3587 if (net->user_ns != &init_user_ns) { 3588 if (tbl[0].procname != ipv4_route_flush_procname) 3589 table_size = 0; 3590 } 3591 3592 /* Update the variables to point into the current struct net 3593 * except for the first element flush 3594 */ 3595 for (i = 1; i < table_size; i++) 3596 tbl[i].data += (void *)net - (void *)&init_net; 3597 } 3598 tbl[0].extra1 = net; 3599 3600 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3601 tbl, table_size); 3602 if (!net->ipv4.route_hdr) 3603 goto err_reg; 3604 return 0; 3605 3606 err_reg: 3607 if (tbl != ipv4_route_netns_table) 3608 kfree(tbl); 3609 err_dup: 3610 return -ENOMEM; 3611 } 3612 3613 static __net_exit void sysctl_route_net_exit(struct net *net) 3614 { 3615 const struct ctl_table *tbl; 3616 3617 tbl = net->ipv4.route_hdr->ctl_table_arg; 3618 unregister_net_sysctl_table(net->ipv4.route_hdr); 3619 BUG_ON(tbl == ipv4_route_netns_table); 3620 kfree(tbl); 3621 } 3622 3623 static __net_initdata struct pernet_operations sysctl_route_ops = { 3624 .init = sysctl_route_net_init, 3625 .exit = sysctl_route_net_exit, 3626 }; 3627 #endif 3628 3629 static __net_init int netns_ip_rt_init(struct net *net) 3630 { 3631 /* Set default value for namespaceified sysctls */ 3632 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3633 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3634 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3635 return 0; 3636 } 3637 3638 static struct pernet_operations __net_initdata ip_rt_ops = { 3639 .init = netns_ip_rt_init, 3640 }; 3641 3642 static __net_init int rt_genid_init(struct net *net) 3643 { 3644 atomic_set(&net->ipv4.rt_genid, 0); 3645 atomic_set(&net->fnhe_genid, 0); 3646 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3647 return 0; 3648 } 3649 3650 static __net_initdata struct pernet_operations rt_genid_ops = { 3651 .init = rt_genid_init, 3652 }; 3653 3654 static int __net_init ipv4_inetpeer_init(struct net *net) 3655 { 3656 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3657 3658 if (!bp) 3659 return -ENOMEM; 3660 inet_peer_base_init(bp); 3661 net->ipv4.peers = bp; 3662 return 0; 3663 } 3664 3665 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3666 { 3667 struct inet_peer_base *bp = net->ipv4.peers; 3668 3669 net->ipv4.peers = NULL; 3670 inetpeer_invalidate_tree(bp); 3671 kfree(bp); 3672 } 3673 3674 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3675 .init = ipv4_inetpeer_init, 3676 .exit = ipv4_inetpeer_exit, 3677 }; 3678 3679 #ifdef CONFIG_IP_ROUTE_CLASSID 3680 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3681 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3682 3683 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3684 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3685 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3686 }; 3687 3688 int __init ip_rt_init(void) 3689 { 3690 void *idents_hash; 3691 int cpu; 3692 3693 /* For modern hosts, this will use 2 MB of memory */ 3694 idents_hash = alloc_large_system_hash("IP idents", 3695 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3696 0, 3697 16, /* one bucket per 64 KB */ 3698 HASH_ZERO, 3699 NULL, 3700 &ip_idents_mask, 3701 2048, 3702 256*1024); 3703 3704 ip_idents = idents_hash; 3705 3706 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3707 3708 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3709 3710 for_each_possible_cpu(cpu) { 3711 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3712 3713 INIT_LIST_HEAD(&ul->head); 3714 spin_lock_init(&ul->lock); 3715 } 3716 #ifdef CONFIG_IP_ROUTE_CLASSID 3717 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3718 if (!ip_rt_acct) 3719 panic("IP: failed to allocate ip_rt_acct\n"); 3720 #endif 3721 3722 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3723 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3724 3725 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3726 3727 if (dst_entries_init(&ipv4_dst_ops) < 0) 3728 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3729 3730 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3731 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3732 3733 ipv4_dst_ops.gc_thresh = ~0; 3734 ip_rt_max_size = INT_MAX; 3735 3736 devinet_init(); 3737 ip_fib_init(); 3738 3739 if (ip_rt_proc_init()) 3740 pr_err("Unable to create route proc files\n"); 3741 #ifdef CONFIG_XFRM 3742 xfrm_init(); 3743 xfrm4_init(); 3744 #endif 3745 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3746 3747 #ifdef CONFIG_SYSCTL 3748 register_pernet_subsys(&sysctl_route_ops); 3749 #endif 3750 register_pernet_subsys(&ip_rt_ops); 3751 register_pernet_subsys(&rt_genid_ops); 3752 register_pernet_subsys(&ipv4_inetpeer_ops); 3753 return 0; 3754 } 3755 3756 #ifdef CONFIG_SYSCTL 3757 /* 3758 * We really need to sanitize the damn ipv4 init order, then all 3759 * this nonsense will go away. 3760 */ 3761 void __init ip_static_sysctl_init(void) 3762 { 3763 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3764 } 3765 #endif 3766