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 #ifndef CONFIG_PREEMPT_RT 193 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 194 #else 195 #define RT_CACHE_STAT_INC(field) this_cpu_inc(rt_cache_stat.field) 196 #endif 197 198 #ifdef CONFIG_PROC_FS 199 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 200 { 201 if (*pos) 202 return NULL; 203 return SEQ_START_TOKEN; 204 } 205 206 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 207 { 208 ++*pos; 209 return NULL; 210 } 211 212 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 213 { 214 } 215 216 static int rt_cache_seq_show(struct seq_file *seq, void *v) 217 { 218 if (v == SEQ_START_TOKEN) 219 seq_printf(seq, "%-127s\n", 220 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 221 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 222 "HHUptod\tSpecDst"); 223 return 0; 224 } 225 226 static const struct seq_operations rt_cache_seq_ops = { 227 .start = rt_cache_seq_start, 228 .next = rt_cache_seq_next, 229 .stop = rt_cache_seq_stop, 230 .show = rt_cache_seq_show, 231 }; 232 233 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 234 { 235 int cpu; 236 237 if (*pos == 0) 238 return SEQ_START_TOKEN; 239 240 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 241 if (!cpu_possible(cpu)) 242 continue; 243 *pos = cpu+1; 244 return &per_cpu(rt_cache_stat, cpu); 245 } 246 return NULL; 247 } 248 249 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 250 { 251 int cpu; 252 253 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 254 if (!cpu_possible(cpu)) 255 continue; 256 *pos = cpu+1; 257 return &per_cpu(rt_cache_stat, cpu); 258 } 259 (*pos)++; 260 return NULL; 261 262 } 263 264 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 265 { 266 267 } 268 269 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 270 { 271 struct rt_cache_stat *st = v; 272 273 if (v == SEQ_START_TOKEN) { 274 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"); 275 return 0; 276 } 277 278 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x " 279 "%08x %08x %08x %08x %08x %08x " 280 "%08x %08x %08x %08x\n", 281 dst_entries_get_slow(&ipv4_dst_ops), 282 0, /* st->in_hit */ 283 st->in_slow_tot, 284 st->in_slow_mc, 285 st->in_no_route, 286 st->in_brd, 287 st->in_martian_dst, 288 st->in_martian_src, 289 290 0, /* st->out_hit */ 291 st->out_slow_tot, 292 st->out_slow_mc, 293 294 0, /* st->gc_total */ 295 0, /* st->gc_ignored */ 296 0, /* st->gc_goal_miss */ 297 0, /* st->gc_dst_overflow */ 298 0, /* st->in_hlist_search */ 299 0 /* st->out_hlist_search */ 300 ); 301 return 0; 302 } 303 304 static const struct seq_operations rt_cpu_seq_ops = { 305 .start = rt_cpu_seq_start, 306 .next = rt_cpu_seq_next, 307 .stop = rt_cpu_seq_stop, 308 .show = rt_cpu_seq_show, 309 }; 310 311 #ifdef CONFIG_IP_ROUTE_CLASSID 312 static int rt_acct_proc_show(struct seq_file *m, void *v) 313 { 314 struct ip_rt_acct *dst, *src; 315 unsigned int i, j; 316 317 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 318 if (!dst) 319 return -ENOMEM; 320 321 for_each_possible_cpu(i) { 322 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 323 for (j = 0; j < 256; j++) { 324 dst[j].o_bytes += src[j].o_bytes; 325 dst[j].o_packets += src[j].o_packets; 326 dst[j].i_bytes += src[j].i_bytes; 327 dst[j].i_packets += src[j].i_packets; 328 } 329 } 330 331 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 332 kfree(dst); 333 return 0; 334 } 335 #endif 336 337 static int __net_init ip_rt_do_proc_init(struct net *net) 338 { 339 struct proc_dir_entry *pde; 340 341 pde = proc_create_seq("rt_cache", 0444, net->proc_net, 342 &rt_cache_seq_ops); 343 if (!pde) 344 goto err1; 345 346 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat, 347 &rt_cpu_seq_ops); 348 if (!pde) 349 goto err2; 350 351 #ifdef CONFIG_IP_ROUTE_CLASSID 352 pde = proc_create_single("rt_acct", 0, net->proc_net, 353 rt_acct_proc_show); 354 if (!pde) 355 goto err3; 356 #endif 357 return 0; 358 359 #ifdef CONFIG_IP_ROUTE_CLASSID 360 err3: 361 remove_proc_entry("rt_cache", net->proc_net_stat); 362 #endif 363 err2: 364 remove_proc_entry("rt_cache", net->proc_net); 365 err1: 366 return -ENOMEM; 367 } 368 369 static void __net_exit ip_rt_do_proc_exit(struct net *net) 370 { 371 remove_proc_entry("rt_cache", net->proc_net_stat); 372 remove_proc_entry("rt_cache", net->proc_net); 373 #ifdef CONFIG_IP_ROUTE_CLASSID 374 remove_proc_entry("rt_acct", net->proc_net); 375 #endif 376 } 377 378 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 379 .init = ip_rt_do_proc_init, 380 .exit = ip_rt_do_proc_exit, 381 }; 382 383 static int __init ip_rt_proc_init(void) 384 { 385 return register_pernet_subsys(&ip_rt_proc_ops); 386 } 387 388 #else 389 static inline int ip_rt_proc_init(void) 390 { 391 return 0; 392 } 393 #endif /* CONFIG_PROC_FS */ 394 395 static inline bool rt_is_expired(const struct rtable *rth) 396 { 397 bool res; 398 399 rcu_read_lock(); 400 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev)); 401 rcu_read_unlock(); 402 403 return res; 404 } 405 406 void rt_cache_flush(struct net *net) 407 { 408 rt_genid_bump_ipv4(net); 409 } 410 411 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 412 struct sk_buff *skb, 413 const void *daddr) 414 { 415 const struct rtable *rt = container_of(dst, struct rtable, dst); 416 struct net_device *dev = dst->dev; 417 struct neighbour *n; 418 419 rcu_read_lock(); 420 421 if (likely(rt->rt_gw_family == AF_INET)) { 422 n = ip_neigh_gw4(dev, rt->rt_gw4); 423 } else if (rt->rt_gw_family == AF_INET6) { 424 n = ip_neigh_gw6(dev, &rt->rt_gw6); 425 } else { 426 __be32 pkey; 427 428 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 429 n = ip_neigh_gw4(dev, pkey); 430 } 431 432 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt)) 433 n = NULL; 434 435 rcu_read_unlock(); 436 437 return n; 438 } 439 440 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 441 { 442 const struct rtable *rt = container_of(dst, struct rtable, dst); 443 struct net_device *dev = dst->dev; 444 const __be32 *pkey = daddr; 445 446 if (rt->rt_gw_family == AF_INET) { 447 pkey = (const __be32 *)&rt->rt_gw4; 448 } else if (rt->rt_gw_family == AF_INET6) { 449 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 450 } else if (!daddr || 451 (rt->rt_flags & 452 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 453 return; 454 } 455 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 456 } 457 458 /* Hash tables of size 2048..262144 depending on RAM size. 459 * Each bucket uses 8 bytes. 460 */ 461 static u32 ip_idents_mask __read_mostly; 462 static atomic_t *ip_idents __read_mostly; 463 static u32 *ip_tstamps __read_mostly; 464 465 /* In order to protect privacy, we add a perturbation to identifiers 466 * if one generator is seldom used. This makes hard for an attacker 467 * to infer how many packets were sent between two points in time. 468 */ 469 static u32 ip_idents_reserve(u32 hash, int segs) 470 { 471 u32 bucket, old, now = (u32)jiffies; 472 atomic_t *p_id; 473 u32 *p_tstamp; 474 u32 delta = 0; 475 476 bucket = hash & ip_idents_mask; 477 p_tstamp = ip_tstamps + bucket; 478 p_id = ip_idents + bucket; 479 old = READ_ONCE(*p_tstamp); 480 481 if (old != now && cmpxchg(p_tstamp, old, now) == old) 482 delta = get_random_u32_below(now - old); 483 484 /* If UBSAN reports an error there, please make sure your compiler 485 * supports -fno-strict-overflow before reporting it that was a bug 486 * in UBSAN, and it has been fixed in GCC-8. 487 */ 488 return atomic_add_return(segs + delta, p_id) - segs; 489 } 490 491 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 492 { 493 u32 hash, id; 494 495 /* Note the following code is not safe, but this is okay. */ 496 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 497 get_random_bytes(&net->ipv4.ip_id_key, 498 sizeof(net->ipv4.ip_id_key)); 499 500 hash = siphash_3u32((__force u32)iph->daddr, 501 (__force u32)iph->saddr, 502 iph->protocol, 503 &net->ipv4.ip_id_key); 504 id = ip_idents_reserve(hash, segs); 505 iph->id = htons(id); 506 } 507 EXPORT_SYMBOL(__ip_select_ident); 508 509 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 510 const struct sock *sk, const struct iphdr *iph, 511 int oif, __u8 tos, u8 prot, u32 mark, 512 int flow_flags) 513 { 514 __u8 scope = RT_SCOPE_UNIVERSE; 515 516 if (sk) { 517 oif = sk->sk_bound_dev_if; 518 mark = READ_ONCE(sk->sk_mark); 519 tos = ip_sock_rt_tos(sk); 520 scope = ip_sock_rt_scope(sk); 521 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW : 522 sk->sk_protocol; 523 } 524 525 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope, 526 prot, flow_flags, iph->daddr, iph->saddr, 0, 0, 527 sock_net_uid(net, sk)); 528 } 529 530 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 531 const struct sock *sk) 532 { 533 const struct net *net = dev_net(skb->dev); 534 const struct iphdr *iph = ip_hdr(skb); 535 int oif = skb->dev->ifindex; 536 u8 prot = iph->protocol; 537 u32 mark = skb->mark; 538 __u8 tos = iph->tos; 539 540 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 541 } 542 543 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 544 { 545 const struct inet_sock *inet = inet_sk(sk); 546 const struct ip_options_rcu *inet_opt; 547 __be32 daddr = inet->inet_daddr; 548 549 rcu_read_lock(); 550 inet_opt = rcu_dereference(inet->inet_opt); 551 if (inet_opt && inet_opt->opt.srr) 552 daddr = inet_opt->opt.faddr; 553 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), 554 ip_sock_rt_tos(sk), 555 ip_sock_rt_scope(sk), 556 inet_test_bit(HDRINCL, sk) ? 557 IPPROTO_RAW : sk->sk_protocol, 558 inet_sk_flowi_flags(sk), 559 daddr, inet->inet_saddr, 0, 0, 560 sk_uid(sk)); 561 rcu_read_unlock(); 562 } 563 564 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 565 const struct sk_buff *skb) 566 { 567 if (skb) 568 build_skb_flow_key(fl4, skb, sk); 569 else 570 build_sk_flow_key(fl4, sk); 571 } 572 573 static DEFINE_SPINLOCK(fnhe_lock); 574 575 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 576 { 577 struct rtable *rt; 578 579 rt = rcu_dereference(fnhe->fnhe_rth_input); 580 if (rt) { 581 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 582 dst_dev_put(&rt->dst); 583 dst_release(&rt->dst); 584 } 585 rt = rcu_dereference(fnhe->fnhe_rth_output); 586 if (rt) { 587 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 588 dst_dev_put(&rt->dst); 589 dst_release(&rt->dst); 590 } 591 } 592 593 static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash) 594 { 595 struct fib_nh_exception __rcu **fnhe_p, **oldest_p; 596 struct fib_nh_exception *fnhe, *oldest = NULL; 597 598 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) { 599 fnhe = rcu_dereference_protected(*fnhe_p, 600 lockdep_is_held(&fnhe_lock)); 601 if (!fnhe) 602 break; 603 if (!oldest || 604 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) { 605 oldest = fnhe; 606 oldest_p = fnhe_p; 607 } 608 } 609 fnhe_flush_routes(oldest); 610 *oldest_p = oldest->fnhe_next; 611 kfree_rcu(oldest, rcu); 612 } 613 614 static u32 fnhe_hashfun(__be32 daddr) 615 { 616 static siphash_aligned_key_t fnhe_hash_key; 617 u64 hval; 618 619 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key)); 620 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key); 621 return hash_64(hval, FNHE_HASH_SHIFT); 622 } 623 624 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 625 { 626 rt->rt_pmtu = fnhe->fnhe_pmtu; 627 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 628 rt->dst.expires = fnhe->fnhe_expires; 629 630 if (fnhe->fnhe_gw) { 631 rt->rt_flags |= RTCF_REDIRECTED; 632 rt->rt_uses_gateway = 1; 633 rt->rt_gw_family = AF_INET; 634 rt->rt_gw4 = fnhe->fnhe_gw; 635 } 636 } 637 638 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 639 __be32 gw, u32 pmtu, bool lock, 640 unsigned long expires) 641 { 642 struct fnhe_hash_bucket *hash; 643 struct fib_nh_exception *fnhe; 644 struct rtable *rt; 645 u32 genid, hval; 646 unsigned int i; 647 int depth; 648 649 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 650 hval = fnhe_hashfun(daddr); 651 652 spin_lock_bh(&fnhe_lock); 653 654 hash = rcu_dereference(nhc->nhc_exceptions); 655 if (!hash) { 656 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 657 if (!hash) 658 goto out_unlock; 659 rcu_assign_pointer(nhc->nhc_exceptions, hash); 660 } 661 662 hash += hval; 663 664 depth = 0; 665 for (fnhe = rcu_dereference(hash->chain); fnhe; 666 fnhe = rcu_dereference(fnhe->fnhe_next)) { 667 if (fnhe->fnhe_daddr == daddr) 668 break; 669 depth++; 670 } 671 672 if (fnhe) { 673 if (fnhe->fnhe_genid != genid) 674 fnhe->fnhe_genid = genid; 675 if (gw) 676 fnhe->fnhe_gw = gw; 677 if (pmtu) { 678 fnhe->fnhe_pmtu = pmtu; 679 fnhe->fnhe_mtu_locked = lock; 680 } 681 fnhe->fnhe_expires = max(1UL, expires); 682 /* Update all cached dsts too */ 683 rt = rcu_dereference(fnhe->fnhe_rth_input); 684 if (rt) 685 fill_route_from_fnhe(rt, fnhe); 686 rt = rcu_dereference(fnhe->fnhe_rth_output); 687 if (rt) 688 fill_route_from_fnhe(rt, fnhe); 689 } else { 690 /* Randomize max depth to avoid some side channels attacks. */ 691 int max_depth = FNHE_RECLAIM_DEPTH + 692 get_random_u32_below(FNHE_RECLAIM_DEPTH); 693 694 while (depth > max_depth) { 695 fnhe_remove_oldest(hash); 696 depth--; 697 } 698 699 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 700 if (!fnhe) 701 goto out_unlock; 702 703 fnhe->fnhe_next = hash->chain; 704 705 fnhe->fnhe_genid = genid; 706 fnhe->fnhe_daddr = daddr; 707 fnhe->fnhe_gw = gw; 708 fnhe->fnhe_pmtu = pmtu; 709 fnhe->fnhe_mtu_locked = lock; 710 fnhe->fnhe_expires = max(1UL, expires); 711 712 rcu_assign_pointer(hash->chain, fnhe); 713 714 /* Exception created; mark the cached routes for the nexthop 715 * stale, so anyone caching it rechecks if this exception 716 * applies to them. 717 */ 718 rt = rcu_dereference(nhc->nhc_rth_input); 719 if (rt) 720 rt->dst.obsolete = DST_OBSOLETE_KILL; 721 722 for_each_possible_cpu(i) { 723 struct rtable __rcu **prt; 724 725 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 726 rt = rcu_dereference(*prt); 727 if (rt) 728 rt->dst.obsolete = DST_OBSOLETE_KILL; 729 } 730 } 731 732 fnhe->fnhe_stamp = jiffies; 733 734 out_unlock: 735 spin_unlock_bh(&fnhe_lock); 736 } 737 738 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 739 bool kill_route) 740 { 741 __be32 new_gw = icmp_hdr(skb)->un.gateway; 742 __be32 old_gw = ip_hdr(skb)->saddr; 743 struct net_device *dev = skb->dev; 744 struct in_device *in_dev; 745 struct fib_result res; 746 struct neighbour *n; 747 struct net *net; 748 749 switch (icmp_hdr(skb)->code & 7) { 750 case ICMP_REDIR_NET: 751 case ICMP_REDIR_NETTOS: 752 case ICMP_REDIR_HOST: 753 case ICMP_REDIR_HOSTTOS: 754 break; 755 756 default: 757 return; 758 } 759 760 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 761 return; 762 763 in_dev = __in_dev_get_rcu(dev); 764 if (!in_dev) 765 return; 766 767 net = dev_net(dev); 768 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 769 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 770 ipv4_is_zeronet(new_gw)) 771 goto reject_redirect; 772 773 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 774 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 775 goto reject_redirect; 776 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 777 goto reject_redirect; 778 } else { 779 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 780 goto reject_redirect; 781 } 782 783 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw); 784 if (!n) 785 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 786 if (!IS_ERR(n)) { 787 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) { 788 neigh_event_send(n, NULL); 789 } else { 790 if (fib_lookup(net, fl4, &res, 0) == 0) { 791 struct fib_nh_common *nhc; 792 793 fib_select_path(net, &res, fl4, skb); 794 nhc = FIB_RES_NHC(res); 795 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 796 0, false, 797 jiffies + ip_rt_gc_timeout); 798 } 799 if (kill_route) 800 rt->dst.obsolete = DST_OBSOLETE_KILL; 801 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 802 } 803 neigh_release(n); 804 } 805 return; 806 807 reject_redirect: 808 #ifdef CONFIG_IP_ROUTE_VERBOSE 809 if (IN_DEV_LOG_MARTIANS(in_dev)) { 810 const struct iphdr *iph = (const struct iphdr *) skb->data; 811 __be32 daddr = iph->daddr; 812 __be32 saddr = iph->saddr; 813 814 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 815 " Advised path = %pI4 -> %pI4\n", 816 &old_gw, dev->name, &new_gw, 817 &saddr, &daddr); 818 } 819 #endif 820 ; 821 } 822 823 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 824 { 825 struct rtable *rt; 826 struct flowi4 fl4; 827 const struct iphdr *iph = (const struct iphdr *) skb->data; 828 struct net *net = dev_net(skb->dev); 829 int oif = skb->dev->ifindex; 830 u8 prot = iph->protocol; 831 u32 mark = skb->mark; 832 __u8 tos = iph->tos; 833 834 rt = dst_rtable(dst); 835 836 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 837 __ip_do_redirect(rt, skb, &fl4, true); 838 } 839 840 static void ipv4_negative_advice(struct sock *sk, 841 struct dst_entry *dst) 842 { 843 struct rtable *rt = dst_rtable(dst); 844 845 if ((dst->obsolete > 0) || 846 (rt->rt_flags & RTCF_REDIRECTED) || 847 rt->dst.expires) 848 sk_dst_reset(sk); 849 } 850 851 /* 852 * Algorithm: 853 * 1. The first ip_rt_redirect_number redirects are sent 854 * with exponential backoff, then we stop sending them at all, 855 * assuming that the host ignores our redirects. 856 * 2. If we did not see packets requiring redirects 857 * during ip_rt_redirect_silence, we assume that the host 858 * forgot redirected route and start to send redirects again. 859 * 860 * This algorithm is much cheaper and more intelligent than dumb load limiting 861 * in icmp.c. 862 * 863 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 864 * and "frag. need" (breaks PMTU discovery) in icmp.c. 865 */ 866 867 void ip_rt_send_redirect(struct sk_buff *skb) 868 { 869 struct rtable *rt = skb_rtable(skb); 870 struct in_device *in_dev; 871 struct inet_peer *peer; 872 struct net *net; 873 int log_martians; 874 int vif; 875 876 rcu_read_lock(); 877 in_dev = __in_dev_get_rcu(rt->dst.dev); 878 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 879 rcu_read_unlock(); 880 return; 881 } 882 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 883 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 884 885 net = dev_net(rt->dst.dev); 886 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif); 887 if (!peer) { 888 rcu_read_unlock(); 889 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 890 rt_nexthop(rt, ip_hdr(skb)->daddr)); 891 return; 892 } 893 894 /* No redirected packets during ip_rt_redirect_silence; 895 * reset the algorithm. 896 */ 897 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 898 peer->rate_tokens = 0; 899 peer->n_redirects = 0; 900 } 901 902 /* Too many ignored redirects; do not send anything 903 * set dst.rate_last to the last seen redirected packet. 904 */ 905 if (peer->n_redirects >= ip_rt_redirect_number) { 906 peer->rate_last = jiffies; 907 goto out_unlock; 908 } 909 910 /* Check for load limit; set rate_last to the latest sent 911 * redirect. 912 */ 913 if (peer->n_redirects == 0 || 914 time_after(jiffies, 915 (peer->rate_last + 916 (ip_rt_redirect_load << peer->n_redirects)))) { 917 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 918 919 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 920 peer->rate_last = jiffies; 921 ++peer->n_redirects; 922 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians && 923 peer->n_redirects == ip_rt_redirect_number) 924 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 925 &ip_hdr(skb)->saddr, inet_iif(skb), 926 &ip_hdr(skb)->daddr, &gw); 927 } 928 out_unlock: 929 rcu_read_unlock(); 930 } 931 932 static int ip_error(struct sk_buff *skb) 933 { 934 struct rtable *rt = skb_rtable(skb); 935 struct net_device *dev = skb->dev; 936 struct in_device *in_dev; 937 struct inet_peer *peer; 938 unsigned long now; 939 struct net *net; 940 SKB_DR(reason); 941 bool send; 942 int code; 943 944 if (netif_is_l3_master(skb->dev)) { 945 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 946 if (!dev) 947 goto out; 948 } 949 950 in_dev = __in_dev_get_rcu(dev); 951 952 /* IP on this device is disabled. */ 953 if (!in_dev) 954 goto out; 955 956 net = dev_net(rt->dst.dev); 957 if (!IN_DEV_FORWARD(in_dev)) { 958 switch (rt->dst.error) { 959 case EHOSTUNREACH: 960 SKB_DR_SET(reason, IP_INADDRERRORS); 961 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 962 break; 963 964 case ENETUNREACH: 965 SKB_DR_SET(reason, IP_INNOROUTES); 966 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 967 break; 968 } 969 goto out; 970 } 971 972 switch (rt->dst.error) { 973 case EINVAL: 974 default: 975 goto out; 976 case EHOSTUNREACH: 977 code = ICMP_HOST_UNREACH; 978 break; 979 case ENETUNREACH: 980 code = ICMP_NET_UNREACH; 981 SKB_DR_SET(reason, IP_INNOROUTES); 982 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 983 break; 984 case EACCES: 985 code = ICMP_PKT_FILTERED; 986 break; 987 } 988 989 rcu_read_lock(); 990 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 991 l3mdev_master_ifindex_rcu(skb->dev)); 992 send = true; 993 if (peer) { 994 now = jiffies; 995 peer->rate_tokens += now - peer->rate_last; 996 if (peer->rate_tokens > ip_rt_error_burst) 997 peer->rate_tokens = ip_rt_error_burst; 998 peer->rate_last = now; 999 if (peer->rate_tokens >= ip_rt_error_cost) 1000 peer->rate_tokens -= ip_rt_error_cost; 1001 else 1002 send = false; 1003 } 1004 rcu_read_unlock(); 1005 1006 if (send) 1007 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1008 1009 out: kfree_skb_reason(skb, reason); 1010 return 0; 1011 } 1012 1013 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1014 { 1015 struct dst_entry *dst = &rt->dst; 1016 struct fib_result res; 1017 bool lock = false; 1018 struct net *net; 1019 u32 old_mtu; 1020 1021 if (ip_mtu_locked(dst)) 1022 return; 1023 1024 old_mtu = ipv4_mtu(dst); 1025 if (old_mtu < mtu) 1026 return; 1027 1028 rcu_read_lock(); 1029 net = dev_net_rcu(dst->dev); 1030 if (mtu < net->ipv4.ip_rt_min_pmtu) { 1031 lock = true; 1032 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu); 1033 } 1034 1035 if (rt->rt_pmtu == mtu && !lock && 1036 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2)) 1037 goto out; 1038 1039 if (fib_lookup(net, fl4, &res, 0) == 0) { 1040 struct fib_nh_common *nhc; 1041 1042 fib_select_path(net, &res, fl4, NULL); 1043 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1044 if (fib_info_num_path(res.fi) > 1) { 1045 int nhsel; 1046 1047 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) { 1048 nhc = fib_info_nhc(res.fi, nhsel); 1049 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1050 jiffies + net->ipv4.ip_rt_mtu_expires); 1051 } 1052 goto out; 1053 } 1054 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1055 nhc = FIB_RES_NHC(res); 1056 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1057 jiffies + net->ipv4.ip_rt_mtu_expires); 1058 } 1059 out: 1060 rcu_read_unlock(); 1061 } 1062 1063 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1064 struct sk_buff *skb, u32 mtu, 1065 bool confirm_neigh) 1066 { 1067 struct rtable *rt = dst_rtable(dst); 1068 struct flowi4 fl4; 1069 1070 ip_rt_build_flow_key(&fl4, sk, skb); 1071 1072 /* Don't make lookup fail for bridged encapsulations */ 1073 if (skb && netif_is_any_bridge_port(skb->dev)) 1074 fl4.flowi4_oif = 0; 1075 1076 __ip_rt_update_pmtu(rt, &fl4, mtu); 1077 } 1078 1079 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1080 int oif, u8 protocol) 1081 { 1082 const struct iphdr *iph = (const struct iphdr *)skb->data; 1083 struct flowi4 fl4; 1084 struct rtable *rt; 1085 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1086 1087 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark, 1088 0); 1089 rt = __ip_route_output_key(net, &fl4); 1090 if (!IS_ERR(rt)) { 1091 __ip_rt_update_pmtu(rt, &fl4, mtu); 1092 ip_rt_put(rt); 1093 } 1094 } 1095 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1096 1097 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1098 { 1099 const struct iphdr *iph = (const struct iphdr *)skb->data; 1100 struct flowi4 fl4; 1101 struct rtable *rt; 1102 1103 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1104 1105 if (!fl4.flowi4_mark) 1106 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1107 1108 rt = __ip_route_output_key(sock_net(sk), &fl4); 1109 if (!IS_ERR(rt)) { 1110 __ip_rt_update_pmtu(rt, &fl4, mtu); 1111 ip_rt_put(rt); 1112 } 1113 } 1114 1115 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1116 { 1117 const struct iphdr *iph = (const struct iphdr *)skb->data; 1118 struct flowi4 fl4; 1119 struct rtable *rt; 1120 struct dst_entry *odst = NULL; 1121 bool new = false; 1122 struct net *net = sock_net(sk); 1123 1124 bh_lock_sock(sk); 1125 1126 if (!ip_sk_accept_pmtu(sk)) 1127 goto out; 1128 1129 odst = sk_dst_get(sk); 1130 1131 if (sock_owned_by_user(sk) || !odst) { 1132 __ipv4_sk_update_pmtu(skb, sk, mtu); 1133 goto out; 1134 } 1135 1136 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1137 1138 rt = dst_rtable(odst); 1139 if (odst->obsolete && !odst->ops->check(odst, 0)) { 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 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu); 1148 1149 if (!dst_check(&rt->dst, 0)) { 1150 if (new) 1151 dst_release(&rt->dst); 1152 1153 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1154 if (IS_ERR(rt)) 1155 goto out; 1156 1157 new = true; 1158 } 1159 1160 if (new) 1161 sk_dst_set(sk, &rt->dst); 1162 1163 out: 1164 bh_unlock_sock(sk); 1165 dst_release(odst); 1166 } 1167 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1168 1169 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1170 int oif, u8 protocol) 1171 { 1172 const struct iphdr *iph = (const struct iphdr *)skb->data; 1173 struct flowi4 fl4; 1174 struct rtable *rt; 1175 1176 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0); 1177 rt = __ip_route_output_key(net, &fl4); 1178 if (!IS_ERR(rt)) { 1179 __ip_do_redirect(rt, skb, &fl4, false); 1180 ip_rt_put(rt); 1181 } 1182 } 1183 EXPORT_SYMBOL_GPL(ipv4_redirect); 1184 1185 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1186 { 1187 const struct iphdr *iph = (const struct iphdr *)skb->data; 1188 struct flowi4 fl4; 1189 struct rtable *rt; 1190 struct net *net = sock_net(sk); 1191 1192 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1193 rt = __ip_route_output_key(net, &fl4); 1194 if (!IS_ERR(rt)) { 1195 __ip_do_redirect(rt, skb, &fl4, false); 1196 ip_rt_put(rt); 1197 } 1198 } 1199 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1200 1201 INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst, 1202 u32 cookie) 1203 { 1204 struct rtable *rt = dst_rtable(dst); 1205 1206 /* All IPV4 dsts are created with ->obsolete set to the value 1207 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1208 * into this function always. 1209 * 1210 * When a PMTU/redirect information update invalidates a route, 1211 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1212 * DST_OBSOLETE_DEAD. 1213 */ 1214 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1215 return NULL; 1216 return dst; 1217 } 1218 EXPORT_INDIRECT_CALLABLE(ipv4_dst_check); 1219 1220 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1221 { 1222 struct net_device *dev; 1223 struct ip_options opt; 1224 int res; 1225 1226 /* Recompile ip options since IPCB may not be valid anymore. 1227 * Also check we have a reasonable ipv4 header. 1228 */ 1229 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1230 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1231 return; 1232 1233 memset(&opt, 0, sizeof(opt)); 1234 if (ip_hdr(skb)->ihl > 5) { 1235 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1236 return; 1237 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1238 1239 rcu_read_lock(); 1240 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev; 1241 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL); 1242 rcu_read_unlock(); 1243 1244 if (res) 1245 return; 1246 } 1247 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1248 } 1249 1250 static void ipv4_link_failure(struct sk_buff *skb) 1251 { 1252 struct rtable *rt; 1253 1254 ipv4_send_dest_unreach(skb); 1255 1256 rt = skb_rtable(skb); 1257 if (rt) 1258 dst_set_expires(&rt->dst, 0); 1259 } 1260 1261 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1262 { 1263 pr_debug("%s: %pI4 -> %pI4, %s\n", 1264 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1265 skb->dev ? skb->dev->name : "?"); 1266 kfree_skb(skb); 1267 WARN_ON(1); 1268 return 0; 1269 } 1270 1271 /* 1272 * We do not cache source address of outgoing interface, 1273 * because it is used only by IP RR, TS and SRR options, 1274 * so that it out of fast path. 1275 * 1276 * BTW remember: "addr" is allowed to be not aligned 1277 * in IP options! 1278 */ 1279 1280 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1281 { 1282 __be32 src; 1283 1284 if (rt_is_output_route(rt)) 1285 src = ip_hdr(skb)->saddr; 1286 else { 1287 struct fib_result res; 1288 struct iphdr *iph = ip_hdr(skb); 1289 struct flowi4 fl4 = { 1290 .daddr = iph->daddr, 1291 .saddr = iph->saddr, 1292 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)), 1293 .flowi4_oif = rt->dst.dev->ifindex, 1294 .flowi4_iif = skb->dev->ifindex, 1295 .flowi4_mark = skb->mark, 1296 }; 1297 1298 rcu_read_lock(); 1299 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1300 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1301 else 1302 src = inet_select_addr(rt->dst.dev, 1303 rt_nexthop(rt, iph->daddr), 1304 RT_SCOPE_UNIVERSE); 1305 rcu_read_unlock(); 1306 } 1307 memcpy(addr, &src, 4); 1308 } 1309 1310 #ifdef CONFIG_IP_ROUTE_CLASSID 1311 static void set_class_tag(struct rtable *rt, u32 tag) 1312 { 1313 if (!(rt->dst.tclassid & 0xFFFF)) 1314 rt->dst.tclassid |= tag & 0xFFFF; 1315 if (!(rt->dst.tclassid & 0xFFFF0000)) 1316 rt->dst.tclassid |= tag & 0xFFFF0000; 1317 } 1318 #endif 1319 1320 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1321 { 1322 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1323 unsigned int advmss; 1324 struct net *net; 1325 1326 rcu_read_lock(); 1327 net = dev_net_rcu(dst->dev); 1328 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1329 net->ipv4.ip_rt_min_advmss); 1330 rcu_read_unlock(); 1331 1332 return min(advmss, IPV4_MAX_PMTU - header_size); 1333 } 1334 1335 INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) 1336 { 1337 return ip_dst_mtu_maybe_forward(dst, false); 1338 } 1339 EXPORT_INDIRECT_CALLABLE(ipv4_mtu); 1340 1341 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1342 { 1343 struct fnhe_hash_bucket *hash; 1344 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1345 u32 hval = fnhe_hashfun(daddr); 1346 1347 spin_lock_bh(&fnhe_lock); 1348 1349 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1350 lockdep_is_held(&fnhe_lock)); 1351 hash += hval; 1352 1353 fnhe_p = &hash->chain; 1354 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1355 while (fnhe) { 1356 if (fnhe->fnhe_daddr == daddr) { 1357 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1358 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1359 /* set fnhe_daddr to 0 to ensure it won't bind with 1360 * new dsts in rt_bind_exception(). 1361 */ 1362 fnhe->fnhe_daddr = 0; 1363 fnhe_flush_routes(fnhe); 1364 kfree_rcu(fnhe, rcu); 1365 break; 1366 } 1367 fnhe_p = &fnhe->fnhe_next; 1368 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1369 lockdep_is_held(&fnhe_lock)); 1370 } 1371 1372 spin_unlock_bh(&fnhe_lock); 1373 } 1374 1375 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1376 __be32 daddr) 1377 { 1378 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1379 struct fib_nh_exception *fnhe; 1380 u32 hval; 1381 1382 if (!hash) 1383 return NULL; 1384 1385 hval = fnhe_hashfun(daddr); 1386 1387 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1388 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1389 if (fnhe->fnhe_daddr == daddr) { 1390 if (fnhe->fnhe_expires && 1391 time_after(jiffies, fnhe->fnhe_expires)) { 1392 ip_del_fnhe(nhc, daddr); 1393 break; 1394 } 1395 return fnhe; 1396 } 1397 } 1398 return NULL; 1399 } 1400 1401 /* MTU selection: 1402 * 1. mtu on route is locked - use it 1403 * 2. mtu from nexthop exception 1404 * 3. mtu from egress device 1405 */ 1406 1407 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1408 { 1409 struct fib_nh_common *nhc = res->nhc; 1410 struct net_device *dev = nhc->nhc_dev; 1411 struct fib_info *fi = res->fi; 1412 u32 mtu = 0; 1413 1414 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) || 1415 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1416 mtu = fi->fib_mtu; 1417 1418 if (likely(!mtu)) { 1419 struct fib_nh_exception *fnhe; 1420 1421 fnhe = find_exception(nhc, daddr); 1422 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1423 mtu = fnhe->fnhe_pmtu; 1424 } 1425 1426 if (likely(!mtu)) 1427 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1428 1429 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1430 } 1431 1432 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1433 __be32 daddr, const bool do_cache) 1434 { 1435 bool ret = false; 1436 1437 spin_lock_bh(&fnhe_lock); 1438 1439 if (daddr == fnhe->fnhe_daddr) { 1440 struct rtable __rcu **porig; 1441 struct rtable *orig; 1442 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1443 1444 if (rt_is_input_route(rt)) 1445 porig = &fnhe->fnhe_rth_input; 1446 else 1447 porig = &fnhe->fnhe_rth_output; 1448 orig = rcu_dereference(*porig); 1449 1450 if (fnhe->fnhe_genid != genid) { 1451 fnhe->fnhe_genid = genid; 1452 fnhe->fnhe_gw = 0; 1453 fnhe->fnhe_pmtu = 0; 1454 fnhe->fnhe_expires = 0; 1455 fnhe->fnhe_mtu_locked = false; 1456 fnhe_flush_routes(fnhe); 1457 orig = NULL; 1458 } 1459 fill_route_from_fnhe(rt, fnhe); 1460 if (!rt->rt_gw4) { 1461 rt->rt_gw4 = daddr; 1462 rt->rt_gw_family = AF_INET; 1463 } 1464 1465 if (do_cache) { 1466 dst_hold(&rt->dst); 1467 rcu_assign_pointer(*porig, rt); 1468 if (orig) { 1469 dst_dev_put(&orig->dst); 1470 dst_release(&orig->dst); 1471 } 1472 ret = true; 1473 } 1474 1475 fnhe->fnhe_stamp = jiffies; 1476 } 1477 spin_unlock_bh(&fnhe_lock); 1478 1479 return ret; 1480 } 1481 1482 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1483 { 1484 struct rtable *orig, *prev, **p; 1485 bool ret = true; 1486 1487 if (rt_is_input_route(rt)) { 1488 p = (struct rtable **)&nhc->nhc_rth_input; 1489 } else { 1490 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1491 } 1492 orig = *p; 1493 1494 /* hold dst before doing cmpxchg() to avoid race condition 1495 * on this dst 1496 */ 1497 dst_hold(&rt->dst); 1498 prev = cmpxchg(p, orig, rt); 1499 if (prev == orig) { 1500 if (orig) { 1501 rt_add_uncached_list(orig); 1502 dst_release(&orig->dst); 1503 } 1504 } else { 1505 dst_release(&rt->dst); 1506 ret = false; 1507 } 1508 1509 return ret; 1510 } 1511 1512 struct uncached_list { 1513 spinlock_t lock; 1514 struct list_head head; 1515 }; 1516 1517 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1518 1519 void rt_add_uncached_list(struct rtable *rt) 1520 { 1521 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1522 1523 rt->dst.rt_uncached_list = ul; 1524 1525 spin_lock_bh(&ul->lock); 1526 list_add_tail(&rt->dst.rt_uncached, &ul->head); 1527 spin_unlock_bh(&ul->lock); 1528 } 1529 1530 void rt_del_uncached_list(struct rtable *rt) 1531 { 1532 if (!list_empty(&rt->dst.rt_uncached)) { 1533 struct uncached_list *ul = rt->dst.rt_uncached_list; 1534 1535 spin_lock_bh(&ul->lock); 1536 list_del_init(&rt->dst.rt_uncached); 1537 spin_unlock_bh(&ul->lock); 1538 } 1539 } 1540 1541 static void ipv4_dst_destroy(struct dst_entry *dst) 1542 { 1543 ip_dst_metrics_put(dst); 1544 rt_del_uncached_list(dst_rtable(dst)); 1545 } 1546 1547 void rt_flush_dev(struct net_device *dev) 1548 { 1549 struct rtable *rt, *safe; 1550 int cpu; 1551 1552 for_each_possible_cpu(cpu) { 1553 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1554 1555 if (list_empty(&ul->head)) 1556 continue; 1557 1558 spin_lock_bh(&ul->lock); 1559 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 1560 if (rt->dst.dev != dev) 1561 continue; 1562 rt->dst.dev = blackhole_netdev; 1563 netdev_ref_replace(dev, blackhole_netdev, 1564 &rt->dst.dev_tracker, GFP_ATOMIC); 1565 list_del_init(&rt->dst.rt_uncached); 1566 } 1567 spin_unlock_bh(&ul->lock); 1568 } 1569 } 1570 1571 static bool rt_cache_valid(const struct rtable *rt) 1572 { 1573 return rt && 1574 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1575 !rt_is_expired(rt); 1576 } 1577 1578 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1579 const struct fib_result *res, 1580 struct fib_nh_exception *fnhe, 1581 struct fib_info *fi, u16 type, u32 itag, 1582 const bool do_cache) 1583 { 1584 bool cached = false; 1585 1586 if (fi) { 1587 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1588 1589 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1590 rt->rt_uses_gateway = 1; 1591 rt->rt_gw_family = nhc->nhc_gw_family; 1592 /* only INET and INET6 are supported */ 1593 if (likely(nhc->nhc_gw_family == AF_INET)) 1594 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1595 else 1596 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1597 } 1598 1599 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1600 1601 #ifdef CONFIG_IP_ROUTE_CLASSID 1602 if (nhc->nhc_family == AF_INET) { 1603 struct fib_nh *nh; 1604 1605 nh = container_of(nhc, struct fib_nh, nh_common); 1606 rt->dst.tclassid = nh->nh_tclassid; 1607 } 1608 #endif 1609 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1610 if (unlikely(fnhe)) 1611 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1612 else if (do_cache) 1613 cached = rt_cache_route(nhc, rt); 1614 if (unlikely(!cached)) { 1615 /* Routes we intend to cache in nexthop exception or 1616 * FIB nexthop have the DST_NOCACHE bit clear. 1617 * However, if we are unsuccessful at storing this 1618 * route into the cache we really need to set it. 1619 */ 1620 if (!rt->rt_gw4) { 1621 rt->rt_gw_family = AF_INET; 1622 rt->rt_gw4 = daddr; 1623 } 1624 rt_add_uncached_list(rt); 1625 } 1626 } else 1627 rt_add_uncached_list(rt); 1628 1629 #ifdef CONFIG_IP_ROUTE_CLASSID 1630 #ifdef CONFIG_IP_MULTIPLE_TABLES 1631 set_class_tag(rt, res->tclassid); 1632 #endif 1633 set_class_tag(rt, itag); 1634 #endif 1635 } 1636 1637 struct rtable *rt_dst_alloc(struct net_device *dev, 1638 unsigned int flags, u16 type, 1639 bool noxfrm) 1640 { 1641 struct rtable *rt; 1642 1643 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1644 (noxfrm ? DST_NOXFRM : 0)); 1645 1646 if (rt) { 1647 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1648 rt->rt_flags = flags; 1649 rt->rt_type = type; 1650 rt->rt_is_input = 0; 1651 rt->rt_iif = 0; 1652 rt->rt_pmtu = 0; 1653 rt->rt_mtu_locked = 0; 1654 rt->rt_uses_gateway = 0; 1655 rt->rt_gw_family = 0; 1656 rt->rt_gw4 = 0; 1657 1658 rt->dst.output = ip_output; 1659 if (flags & RTCF_LOCAL) 1660 rt->dst.input = ip_local_deliver; 1661 } 1662 1663 return rt; 1664 } 1665 EXPORT_SYMBOL(rt_dst_alloc); 1666 1667 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt) 1668 { 1669 struct rtable *new_rt; 1670 1671 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK, 1672 rt->dst.flags); 1673 1674 if (new_rt) { 1675 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1676 new_rt->rt_flags = rt->rt_flags; 1677 new_rt->rt_type = rt->rt_type; 1678 new_rt->rt_is_input = rt->rt_is_input; 1679 new_rt->rt_iif = rt->rt_iif; 1680 new_rt->rt_pmtu = rt->rt_pmtu; 1681 new_rt->rt_mtu_locked = rt->rt_mtu_locked; 1682 new_rt->rt_gw_family = rt->rt_gw_family; 1683 if (rt->rt_gw_family == AF_INET) 1684 new_rt->rt_gw4 = rt->rt_gw4; 1685 else if (rt->rt_gw_family == AF_INET6) 1686 new_rt->rt_gw6 = rt->rt_gw6; 1687 1688 new_rt->dst.input = rt->dst.input; 1689 new_rt->dst.output = rt->dst.output; 1690 new_rt->dst.error = rt->dst.error; 1691 new_rt->dst.lastuse = jiffies; 1692 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate); 1693 } 1694 return new_rt; 1695 } 1696 EXPORT_SYMBOL(rt_dst_clone); 1697 1698 /* called in rcu_read_lock() section */ 1699 enum skb_drop_reason 1700 ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1701 dscp_t dscp, struct net_device *dev, 1702 struct in_device *in_dev, u32 *itag) 1703 { 1704 enum skb_drop_reason reason; 1705 1706 /* Primary sanity checks. */ 1707 if (!in_dev) 1708 return SKB_DROP_REASON_NOT_SPECIFIED; 1709 1710 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1711 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1712 1713 if (skb->protocol != htons(ETH_P_IP)) 1714 return SKB_DROP_REASON_INVALID_PROTO; 1715 1716 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1717 return SKB_DROP_REASON_IP_LOCALNET; 1718 1719 if (ipv4_is_zeronet(saddr)) { 1720 if (!ipv4_is_local_multicast(daddr) && 1721 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1722 return SKB_DROP_REASON_IP_INVALID_SOURCE; 1723 } else { 1724 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 1725 dev, in_dev, itag); 1726 if (reason) 1727 return reason; 1728 } 1729 return SKB_NOT_DROPPED_YET; 1730 } 1731 1732 /* called in rcu_read_lock() section */ 1733 static enum skb_drop_reason 1734 ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1735 dscp_t dscp, struct net_device *dev, int our) 1736 { 1737 struct in_device *in_dev = __in_dev_get_rcu(dev); 1738 unsigned int flags = RTCF_MULTICAST; 1739 enum skb_drop_reason reason; 1740 struct rtable *rth; 1741 u32 itag = 0; 1742 1743 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev, 1744 &itag); 1745 if (reason) 1746 return reason; 1747 1748 if (our) 1749 flags |= RTCF_LOCAL; 1750 1751 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1752 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1753 1754 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1755 false); 1756 if (!rth) 1757 return SKB_DROP_REASON_NOMEM; 1758 1759 #ifdef CONFIG_IP_ROUTE_CLASSID 1760 rth->dst.tclassid = itag; 1761 #endif 1762 rth->dst.output = ip_rt_bug; 1763 rth->rt_is_input= 1; 1764 1765 #ifdef CONFIG_IP_MROUTE 1766 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1767 rth->dst.input = ip_mr_input; 1768 #endif 1769 RT_CACHE_STAT_INC(in_slow_mc); 1770 1771 skb_dst_drop(skb); 1772 skb_dst_set(skb, &rth->dst); 1773 return SKB_NOT_DROPPED_YET; 1774 } 1775 1776 1777 static void ip_handle_martian_source(struct net_device *dev, 1778 struct in_device *in_dev, 1779 struct sk_buff *skb, 1780 __be32 daddr, 1781 __be32 saddr) 1782 { 1783 RT_CACHE_STAT_INC(in_martian_src); 1784 #ifdef CONFIG_IP_ROUTE_VERBOSE 1785 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1786 /* 1787 * RFC1812 recommendation, if source is martian, 1788 * the only hint is MAC header. 1789 */ 1790 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1791 &daddr, &saddr, dev->name); 1792 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1793 print_hex_dump(KERN_WARNING, "ll header: ", 1794 DUMP_PREFIX_OFFSET, 16, 1, 1795 skb_mac_header(skb), 1796 dev->hard_header_len, false); 1797 } 1798 } 1799 #endif 1800 } 1801 1802 /* called in rcu_read_lock() section */ 1803 static enum skb_drop_reason 1804 __mkroute_input(struct sk_buff *skb, const struct fib_result *res, 1805 struct in_device *in_dev, __be32 daddr, 1806 __be32 saddr, dscp_t dscp) 1807 { 1808 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 1809 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1810 struct net_device *dev = nhc->nhc_dev; 1811 struct fib_nh_exception *fnhe; 1812 struct rtable *rth; 1813 int err; 1814 struct in_device *out_dev; 1815 bool do_cache; 1816 u32 itag = 0; 1817 1818 /* get a working reference to the output device */ 1819 out_dev = __in_dev_get_rcu(dev); 1820 if (!out_dev) { 1821 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1822 return reason; 1823 } 1824 1825 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res), 1826 in_dev->dev, in_dev, &itag); 1827 if (err < 0) { 1828 reason = -err; 1829 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1830 saddr); 1831 1832 goto cleanup; 1833 } 1834 1835 do_cache = res->fi && !itag; 1836 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1837 skb->protocol == htons(ETH_P_IP)) { 1838 __be32 gw; 1839 1840 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1841 if (IN_DEV_SHARED_MEDIA(out_dev) || 1842 inet_addr_onlink(out_dev, saddr, gw)) 1843 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1844 } 1845 1846 if (skb->protocol != htons(ETH_P_IP)) { 1847 /* Not IP (i.e. ARP). Do not create route, if it is 1848 * invalid for proxy arp. DNAT routes are always valid. 1849 * 1850 * Proxy arp feature have been extended to allow, ARP 1851 * replies back to the same interface, to support 1852 * Private VLAN switch technologies. See arp.c. 1853 */ 1854 if (out_dev == in_dev && 1855 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1856 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE; 1857 goto cleanup; 1858 } 1859 } 1860 1861 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 1862 IPCB(skb)->flags |= IPSKB_NOPOLICY; 1863 1864 fnhe = find_exception(nhc, daddr); 1865 if (do_cache) { 1866 if (fnhe) 1867 rth = rcu_dereference(fnhe->fnhe_rth_input); 1868 else 1869 rth = rcu_dereference(nhc->nhc_rth_input); 1870 if (rt_cache_valid(rth)) { 1871 skb_dst_set_noref(skb, &rth->dst); 1872 goto out; 1873 } 1874 } 1875 1876 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1877 IN_DEV_ORCONF(out_dev, NOXFRM)); 1878 if (!rth) { 1879 reason = SKB_DROP_REASON_NOMEM; 1880 goto cleanup; 1881 } 1882 1883 rth->rt_is_input = 1; 1884 RT_CACHE_STAT_INC(in_slow_tot); 1885 1886 rth->dst.input = ip_forward; 1887 1888 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1889 do_cache); 1890 lwtunnel_set_redirect(&rth->dst); 1891 skb_dst_set(skb, &rth->dst); 1892 out: 1893 reason = SKB_NOT_DROPPED_YET; 1894 cleanup: 1895 return reason; 1896 } 1897 1898 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1899 /* To make ICMP packets follow the right flow, the multipath hash is 1900 * calculated from the inner IP addresses. 1901 */ 1902 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1903 struct flow_keys *hash_keys) 1904 { 1905 const struct iphdr *outer_iph = ip_hdr(skb); 1906 const struct iphdr *key_iph = outer_iph; 1907 const struct iphdr *inner_iph; 1908 const struct icmphdr *icmph; 1909 struct iphdr _inner_iph; 1910 struct icmphdr _icmph; 1911 1912 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1913 goto out; 1914 1915 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1916 goto out; 1917 1918 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1919 &_icmph); 1920 if (!icmph) 1921 goto out; 1922 1923 if (!icmp_is_err(icmph->type)) 1924 goto out; 1925 1926 inner_iph = skb_header_pointer(skb, 1927 outer_iph->ihl * 4 + sizeof(_icmph), 1928 sizeof(_inner_iph), &_inner_iph); 1929 if (!inner_iph) 1930 goto out; 1931 1932 key_iph = inner_iph; 1933 out: 1934 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1935 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1936 } 1937 1938 static u32 fib_multipath_custom_hash_outer(const struct net *net, 1939 const struct sk_buff *skb, 1940 bool *p_has_inner) 1941 { 1942 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1943 struct flow_keys keys, hash_keys; 1944 1945 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 1946 return 0; 1947 1948 memset(&hash_keys, 0, sizeof(hash_keys)); 1949 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1950 1951 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1952 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 1953 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1954 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 1955 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1956 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 1957 hash_keys.basic.ip_proto = keys.basic.ip_proto; 1958 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 1959 hash_keys.ports.src = keys.ports.src; 1960 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 1961 hash_keys.ports.dst = keys.ports.dst; 1962 1963 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 1964 return fib_multipath_hash_from_keys(net, &hash_keys); 1965 } 1966 1967 static u32 fib_multipath_custom_hash_inner(const struct net *net, 1968 const struct sk_buff *skb, 1969 bool has_inner) 1970 { 1971 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 1972 struct flow_keys keys, hash_keys; 1973 1974 /* We assume the packet carries an encapsulation, but if none was 1975 * encountered during dissection of the outer flow, then there is no 1976 * point in calling the flow dissector again. 1977 */ 1978 if (!has_inner) 1979 return 0; 1980 1981 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 1982 return 0; 1983 1984 memset(&hash_keys, 0, sizeof(hash_keys)); 1985 skb_flow_dissect_flow_keys(skb, &keys, 0); 1986 1987 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 1988 return 0; 1989 1990 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 1991 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1992 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1993 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1994 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 1995 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1996 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 1997 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1998 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 1999 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2000 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2001 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2002 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2003 hash_keys.tags.flow_label = keys.tags.flow_label; 2004 } 2005 2006 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2007 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2008 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2009 hash_keys.ports.src = keys.ports.src; 2010 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2011 hash_keys.ports.dst = keys.ports.dst; 2012 2013 return fib_multipath_hash_from_keys(net, &hash_keys); 2014 } 2015 2016 static u32 fib_multipath_custom_hash_skb(const struct net *net, 2017 const struct sk_buff *skb) 2018 { 2019 u32 mhash, mhash_inner; 2020 bool has_inner = true; 2021 2022 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner); 2023 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner); 2024 2025 return jhash_2words(mhash, mhash_inner, 0); 2026 } 2027 2028 static u32 fib_multipath_custom_hash_fl4(const struct net *net, 2029 const struct flowi4 *fl4) 2030 { 2031 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); 2032 struct flow_keys hash_keys; 2033 2034 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2035 return 0; 2036 2037 memset(&hash_keys, 0, sizeof(hash_keys)); 2038 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2039 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2040 hash_keys.addrs.v4addrs.src = fl4->saddr; 2041 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2042 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2043 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2044 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2045 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) { 2046 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2047 hash_keys.ports.src = (__force __be16)get_random_u16(); 2048 else 2049 hash_keys.ports.src = fl4->fl4_sport; 2050 } 2051 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2052 hash_keys.ports.dst = fl4->fl4_dport; 2053 2054 return fib_multipath_hash_from_keys(net, &hash_keys); 2055 } 2056 2057 /* if skb is set it will be used and fl4 can be NULL */ 2058 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 2059 const struct sk_buff *skb, struct flow_keys *flkeys) 2060 { 2061 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 2062 struct flow_keys hash_keys; 2063 u32 mhash = 0; 2064 2065 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) { 2066 case 0: 2067 memset(&hash_keys, 0, sizeof(hash_keys)); 2068 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2069 if (skb) { 2070 ip_multipath_l3_keys(skb, &hash_keys); 2071 } else { 2072 hash_keys.addrs.v4addrs.src = fl4->saddr; 2073 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2074 } 2075 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2076 break; 2077 case 1: 2078 /* skb is currently provided only when forwarding */ 2079 if (skb) { 2080 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2081 struct flow_keys keys; 2082 2083 /* short-circuit if we already have L4 hash present */ 2084 if (skb->l4_hash) 2085 return skb_get_hash_raw(skb) >> 1; 2086 2087 memset(&hash_keys, 0, sizeof(hash_keys)); 2088 2089 if (!flkeys) { 2090 skb_flow_dissect_flow_keys(skb, &keys, flag); 2091 flkeys = &keys; 2092 } 2093 2094 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2095 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2096 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2097 hash_keys.ports.src = flkeys->ports.src; 2098 hash_keys.ports.dst = flkeys->ports.dst; 2099 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2100 } else { 2101 memset(&hash_keys, 0, sizeof(hash_keys)); 2102 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2103 hash_keys.addrs.v4addrs.src = fl4->saddr; 2104 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2105 if (fl4->flowi4_flags & FLOWI_FLAG_ANY_SPORT) 2106 hash_keys.ports.src = (__force __be16)get_random_u16(); 2107 else 2108 hash_keys.ports.src = fl4->fl4_sport; 2109 hash_keys.ports.dst = fl4->fl4_dport; 2110 hash_keys.basic.ip_proto = fl4->flowi4_proto; 2111 } 2112 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2113 break; 2114 case 2: 2115 memset(&hash_keys, 0, sizeof(hash_keys)); 2116 /* skb is currently provided only when forwarding */ 2117 if (skb) { 2118 struct flow_keys keys; 2119 2120 skb_flow_dissect_flow_keys(skb, &keys, 0); 2121 /* Inner can be v4 or v6 */ 2122 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2123 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2124 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2125 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2126 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2127 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2128 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2129 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2130 hash_keys.tags.flow_label = keys.tags.flow_label; 2131 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2132 } else { 2133 /* Same as case 0 */ 2134 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2135 ip_multipath_l3_keys(skb, &hash_keys); 2136 } 2137 } else { 2138 /* Same as case 0 */ 2139 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2140 hash_keys.addrs.v4addrs.src = fl4->saddr; 2141 hash_keys.addrs.v4addrs.dst = fl4->daddr; 2142 } 2143 mhash = fib_multipath_hash_from_keys(net, &hash_keys); 2144 break; 2145 case 3: 2146 if (skb) 2147 mhash = fib_multipath_custom_hash_skb(net, skb); 2148 else 2149 mhash = fib_multipath_custom_hash_fl4(net, fl4); 2150 break; 2151 } 2152 2153 if (multipath_hash) 2154 mhash = jhash_2words(mhash, multipath_hash, 0); 2155 2156 return mhash >> 1; 2157 } 2158 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 2159 2160 static enum skb_drop_reason 2161 ip_mkroute_input(struct sk_buff *skb, struct fib_result *res, 2162 struct in_device *in_dev, __be32 daddr, 2163 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys) 2164 { 2165 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2166 if (res->fi && fib_info_num_path(res->fi) > 1) { 2167 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 2168 2169 fib_select_multipath(res, h, NULL); 2170 IPCB(skb)->flags |= IPSKB_MULTIPATH; 2171 } 2172 #endif 2173 2174 /* create a routing cache entry */ 2175 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp); 2176 } 2177 2178 /* Implements all the saddr-related checks as ip_route_input_slow(), 2179 * assuming daddr is valid and the destination is not a local broadcast one. 2180 * Uses the provided hint instead of performing a route lookup. 2181 */ 2182 enum skb_drop_reason 2183 ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2184 dscp_t dscp, struct net_device *dev, 2185 const struct sk_buff *hint) 2186 { 2187 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2188 struct in_device *in_dev = __in_dev_get_rcu(dev); 2189 struct rtable *rt = skb_rtable(hint); 2190 struct net *net = dev_net(dev); 2191 u32 tag = 0; 2192 2193 if (!in_dev) 2194 return reason; 2195 2196 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2197 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2198 goto martian_source; 2199 } 2200 2201 if (ipv4_is_zeronet(saddr)) { 2202 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2203 goto martian_source; 2204 } 2205 2206 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2207 reason = SKB_DROP_REASON_IP_LOCALNET; 2208 goto martian_source; 2209 } 2210 2211 if (rt->rt_type != RTN_LOCAL) 2212 goto skip_validate_source; 2213 2214 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev, 2215 in_dev, &tag); 2216 if (reason) 2217 goto martian_source; 2218 2219 skip_validate_source: 2220 skb_dst_copy(skb, hint); 2221 return SKB_NOT_DROPPED_YET; 2222 2223 martian_source: 2224 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2225 return reason; 2226 } 2227 2228 /* get device for dst_alloc with local routes */ 2229 static struct net_device *ip_rt_get_dev(struct net *net, 2230 const struct fib_result *res) 2231 { 2232 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL; 2233 struct net_device *dev = NULL; 2234 2235 if (nhc) 2236 dev = l3mdev_master_dev_rcu(nhc->nhc_dev); 2237 2238 return dev ? : net->loopback_dev; 2239 } 2240 2241 /* 2242 * NOTE. We drop all the packets that has local source 2243 * addresses, because every properly looped back packet 2244 * must have correct destination already attached by output routine. 2245 * Changes in the enforced policies must be applied also to 2246 * ip_route_use_hint(). 2247 * 2248 * Such approach solves two big problems: 2249 * 1. Not simplex devices are handled properly. 2250 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2251 * called with rcu_read_lock() 2252 */ 2253 2254 static enum skb_drop_reason 2255 ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2256 dscp_t dscp, struct net_device *dev, 2257 struct fib_result *res) 2258 { 2259 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2260 struct in_device *in_dev = __in_dev_get_rcu(dev); 2261 struct flow_keys *flkeys = NULL, _flkeys; 2262 struct net *net = dev_net(dev); 2263 struct ip_tunnel_info *tun_info; 2264 int err = -EINVAL; 2265 unsigned int flags = 0; 2266 u32 itag = 0; 2267 struct rtable *rth; 2268 struct flowi4 fl4; 2269 bool do_cache = true; 2270 2271 /* IP on this device is disabled. */ 2272 2273 if (!in_dev) 2274 goto out; 2275 2276 /* Check for the most weird martians, which can be not detected 2277 * by fib_lookup. 2278 */ 2279 2280 tun_info = skb_tunnel_info(skb); 2281 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2282 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2283 else 2284 fl4.flowi4_tun_key.tun_id = 0; 2285 skb_dst_drop(skb); 2286 2287 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) { 2288 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2289 goto martian_source; 2290 } 2291 2292 res->fi = NULL; 2293 res->table = NULL; 2294 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2295 goto brd_input; 2296 2297 /* Accept zero addresses only to limited broadcast; 2298 * I even do not know to fix it or not. Waiting for complains :-) 2299 */ 2300 if (ipv4_is_zeronet(saddr)) { 2301 reason = SKB_DROP_REASON_IP_INVALID_SOURCE; 2302 goto martian_source; 2303 } 2304 2305 if (ipv4_is_zeronet(daddr)) { 2306 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2307 goto martian_destination; 2308 } 2309 2310 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2311 * and call it once if daddr or/and saddr are loopback addresses 2312 */ 2313 if (ipv4_is_loopback(daddr)) { 2314 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2315 reason = SKB_DROP_REASON_IP_LOCALNET; 2316 goto martian_destination; 2317 } 2318 } else if (ipv4_is_loopback(saddr)) { 2319 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) { 2320 reason = SKB_DROP_REASON_IP_LOCALNET; 2321 goto martian_source; 2322 } 2323 } 2324 2325 /* 2326 * Now we are ready to route packet. 2327 */ 2328 fl4.flowi4_l3mdev = 0; 2329 fl4.flowi4_oif = 0; 2330 fl4.flowi4_iif = dev->ifindex; 2331 fl4.flowi4_mark = skb->mark; 2332 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp); 2333 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2334 fl4.flowi4_flags = 0; 2335 fl4.daddr = daddr; 2336 fl4.saddr = saddr; 2337 fl4.flowi4_uid = sock_net_uid(net, NULL); 2338 fl4.flowi4_multipath_hash = 0; 2339 2340 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2341 flkeys = &_flkeys; 2342 } else { 2343 fl4.flowi4_proto = 0; 2344 fl4.fl4_sport = 0; 2345 fl4.fl4_dport = 0; 2346 } 2347 2348 err = fib_lookup(net, &fl4, res, 0); 2349 if (err != 0) { 2350 if (!IN_DEV_FORWARD(in_dev)) 2351 err = -EHOSTUNREACH; 2352 goto no_route; 2353 } 2354 2355 if (res->type == RTN_BROADCAST) { 2356 if (IN_DEV_BFORWARD(in_dev)) 2357 goto make_route; 2358 /* not do cache if bc_forwarding is enabled */ 2359 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING)) 2360 do_cache = false; 2361 goto brd_input; 2362 } 2363 2364 err = -EINVAL; 2365 if (res->type == RTN_LOCAL) { 2366 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 2367 0, dev, in_dev, &itag); 2368 if (reason) 2369 goto martian_source; 2370 goto local_input; 2371 } 2372 2373 if (!IN_DEV_FORWARD(in_dev)) { 2374 err = -EHOSTUNREACH; 2375 goto no_route; 2376 } 2377 if (res->type != RTN_UNICAST) { 2378 reason = SKB_DROP_REASON_IP_INVALID_DEST; 2379 goto martian_destination; 2380 } 2381 2382 make_route: 2383 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp, 2384 flkeys); 2385 2386 out: 2387 return reason; 2388 2389 brd_input: 2390 if (skb->protocol != htons(ETH_P_IP)) { 2391 reason = SKB_DROP_REASON_INVALID_PROTO; 2392 goto out; 2393 } 2394 2395 if (!ipv4_is_zeronet(saddr)) { 2396 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0, 2397 dev, in_dev, &itag); 2398 if (reason) 2399 goto martian_source; 2400 } 2401 flags |= RTCF_BROADCAST; 2402 res->type = RTN_BROADCAST; 2403 RT_CACHE_STAT_INC(in_brd); 2404 2405 local_input: 2406 if (IN_DEV_ORCONF(in_dev, NOPOLICY)) 2407 IPCB(skb)->flags |= IPSKB_NOPOLICY; 2408 2409 do_cache &= res->fi && !itag; 2410 if (do_cache) { 2411 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2412 2413 rth = rcu_dereference(nhc->nhc_rth_input); 2414 if (rt_cache_valid(rth)) { 2415 skb_dst_set_noref(skb, &rth->dst); 2416 reason = SKB_NOT_DROPPED_YET; 2417 goto out; 2418 } 2419 } 2420 2421 rth = rt_dst_alloc(ip_rt_get_dev(net, res), 2422 flags | RTCF_LOCAL, res->type, false); 2423 if (!rth) 2424 goto e_nobufs; 2425 2426 rth->dst.output= ip_rt_bug; 2427 #ifdef CONFIG_IP_ROUTE_CLASSID 2428 rth->dst.tclassid = itag; 2429 #endif 2430 rth->rt_is_input = 1; 2431 2432 RT_CACHE_STAT_INC(in_slow_tot); 2433 if (res->type == RTN_UNREACHABLE) { 2434 rth->dst.input= ip_error; 2435 rth->dst.error= -err; 2436 rth->rt_flags &= ~RTCF_LOCAL; 2437 } 2438 2439 if (do_cache) { 2440 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2441 2442 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2443 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2444 WARN_ON(rth->dst.input == lwtunnel_input); 2445 rth->dst.lwtstate->orig_input = rth->dst.input; 2446 rth->dst.input = lwtunnel_input; 2447 } 2448 2449 if (unlikely(!rt_cache_route(nhc, rth))) 2450 rt_add_uncached_list(rth); 2451 } 2452 skb_dst_set(skb, &rth->dst); 2453 reason = SKB_NOT_DROPPED_YET; 2454 goto out; 2455 2456 no_route: 2457 RT_CACHE_STAT_INC(in_no_route); 2458 res->type = RTN_UNREACHABLE; 2459 res->fi = NULL; 2460 res->table = NULL; 2461 goto local_input; 2462 2463 /* 2464 * Do not cache martian addresses: they should be logged (RFC1812) 2465 */ 2466 martian_destination: 2467 RT_CACHE_STAT_INC(in_martian_dst); 2468 #ifdef CONFIG_IP_ROUTE_VERBOSE 2469 if (IN_DEV_LOG_MARTIANS(in_dev)) 2470 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2471 &daddr, &saddr, dev->name); 2472 #endif 2473 goto out; 2474 2475 e_nobufs: 2476 reason = SKB_DROP_REASON_NOMEM; 2477 goto out; 2478 2479 martian_source: 2480 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2481 goto out; 2482 } 2483 2484 /* called with rcu_read_lock held */ 2485 static enum skb_drop_reason 2486 ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2487 dscp_t dscp, struct net_device *dev, 2488 struct fib_result *res) 2489 { 2490 /* Multicast recognition logic is moved from route cache to here. 2491 * The problem was that too many Ethernet cards have broken/missing 2492 * hardware multicast filters :-( As result the host on multicasting 2493 * network acquires a lot of useless route cache entries, sort of 2494 * SDR messages from all the world. Now we try to get rid of them. 2495 * Really, provided software IP multicast filter is organized 2496 * reasonably (at least, hashed), it does not result in a slowdown 2497 * comparing with route cache reject entries. 2498 * Note, that multicast routers are not affected, because 2499 * route cache entry is created eventually. 2500 */ 2501 if (ipv4_is_multicast(daddr)) { 2502 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; 2503 struct in_device *in_dev = __in_dev_get_rcu(dev); 2504 int our = 0; 2505 2506 if (!in_dev) 2507 return reason; 2508 2509 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2510 ip_hdr(skb)->protocol); 2511 2512 /* check l3 master if no match yet */ 2513 if (!our && netif_is_l3_slave(dev)) { 2514 struct in_device *l3_in_dev; 2515 2516 l3_in_dev = __in_dev_get_rcu(skb->dev); 2517 if (l3_in_dev) 2518 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2519 ip_hdr(skb)->protocol); 2520 } 2521 2522 if (our 2523 #ifdef CONFIG_IP_MROUTE 2524 || 2525 (!ipv4_is_local_multicast(daddr) && 2526 IN_DEV_MFORWARD(in_dev)) 2527 #endif 2528 ) { 2529 reason = ip_route_input_mc(skb, daddr, saddr, dscp, 2530 dev, our); 2531 } 2532 return reason; 2533 } 2534 2535 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res); 2536 } 2537 2538 enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr, 2539 __be32 saddr, dscp_t dscp, 2540 struct net_device *dev) 2541 { 2542 enum skb_drop_reason reason; 2543 struct fib_result res; 2544 2545 rcu_read_lock(); 2546 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res); 2547 rcu_read_unlock(); 2548 2549 return reason; 2550 } 2551 EXPORT_SYMBOL(ip_route_input_noref); 2552 2553 /* called with rcu_read_lock() */ 2554 static struct rtable *__mkroute_output(const struct fib_result *res, 2555 const struct flowi4 *fl4, int orig_oif, 2556 struct net_device *dev_out, 2557 unsigned int flags) 2558 { 2559 struct fib_info *fi = res->fi; 2560 struct fib_nh_exception *fnhe; 2561 struct in_device *in_dev; 2562 u16 type = res->type; 2563 struct rtable *rth; 2564 bool do_cache; 2565 2566 in_dev = __in_dev_get_rcu(dev_out); 2567 if (!in_dev) 2568 return ERR_PTR(-EINVAL); 2569 2570 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2571 if (ipv4_is_loopback(fl4->saddr) && 2572 !(dev_out->flags & IFF_LOOPBACK) && 2573 !netif_is_l3_master(dev_out)) 2574 return ERR_PTR(-EINVAL); 2575 2576 if (ipv4_is_lbcast(fl4->daddr)) 2577 type = RTN_BROADCAST; 2578 else if (ipv4_is_multicast(fl4->daddr)) 2579 type = RTN_MULTICAST; 2580 else if (ipv4_is_zeronet(fl4->daddr)) 2581 return ERR_PTR(-EINVAL); 2582 2583 if (dev_out->flags & IFF_LOOPBACK) 2584 flags |= RTCF_LOCAL; 2585 2586 do_cache = true; 2587 if (type == RTN_BROADCAST) { 2588 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2589 fi = NULL; 2590 } else if (type == RTN_MULTICAST) { 2591 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2592 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2593 fl4->flowi4_proto)) 2594 flags &= ~RTCF_LOCAL; 2595 else 2596 do_cache = false; 2597 /* If multicast route do not exist use 2598 * default one, but do not gateway in this case. 2599 * Yes, it is hack. 2600 */ 2601 if (fi && res->prefixlen < 4) 2602 fi = NULL; 2603 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2604 (orig_oif != dev_out->ifindex)) { 2605 /* For local routes that require a particular output interface 2606 * we do not want to cache the result. Caching the result 2607 * causes incorrect behaviour when there are multiple source 2608 * addresses on the interface, the end result being that if the 2609 * intended recipient is waiting on that interface for the 2610 * packet he won't receive it because it will be delivered on 2611 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2612 * be set to the loopback interface as well. 2613 */ 2614 do_cache = false; 2615 } 2616 2617 fnhe = NULL; 2618 do_cache &= fi != NULL; 2619 if (fi) { 2620 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2621 struct rtable __rcu **prth; 2622 2623 fnhe = find_exception(nhc, fl4->daddr); 2624 if (!do_cache) 2625 goto add; 2626 if (fnhe) { 2627 prth = &fnhe->fnhe_rth_output; 2628 } else { 2629 if (unlikely(fl4->flowi4_flags & 2630 FLOWI_FLAG_KNOWN_NH && 2631 !(nhc->nhc_gw_family && 2632 nhc->nhc_scope == RT_SCOPE_LINK))) { 2633 do_cache = false; 2634 goto add; 2635 } 2636 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2637 } 2638 rth = rcu_dereference(*prth); 2639 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2640 return rth; 2641 } 2642 2643 add: 2644 rth = rt_dst_alloc(dev_out, flags, type, 2645 IN_DEV_ORCONF(in_dev, NOXFRM)); 2646 if (!rth) 2647 return ERR_PTR(-ENOBUFS); 2648 2649 rth->rt_iif = orig_oif; 2650 2651 RT_CACHE_STAT_INC(out_slow_tot); 2652 2653 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2654 if (flags & RTCF_LOCAL && 2655 !(dev_out->flags & IFF_LOOPBACK)) { 2656 rth->dst.output = ip_mc_output; 2657 RT_CACHE_STAT_INC(out_slow_mc); 2658 } 2659 #ifdef CONFIG_IP_MROUTE 2660 if (type == RTN_MULTICAST) { 2661 if (IN_DEV_MFORWARD(in_dev) && 2662 !ipv4_is_local_multicast(fl4->daddr)) { 2663 rth->dst.input = ip_mr_input; 2664 rth->dst.output = ip_mr_output; 2665 } 2666 } 2667 #endif 2668 } 2669 2670 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2671 lwtunnel_set_redirect(&rth->dst); 2672 2673 return rth; 2674 } 2675 2676 /* 2677 * Major route resolver routine. 2678 */ 2679 2680 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2681 const struct sk_buff *skb) 2682 { 2683 struct fib_result res = { 2684 .type = RTN_UNSPEC, 2685 .fi = NULL, 2686 .table = NULL, 2687 .tclassid = 0, 2688 }; 2689 struct rtable *rth; 2690 2691 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2692 fl4->flowi4_tos &= INET_DSCP_MASK; 2693 2694 rcu_read_lock(); 2695 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2696 rcu_read_unlock(); 2697 2698 return rth; 2699 } 2700 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2701 2702 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2703 struct fib_result *res, 2704 const struct sk_buff *skb) 2705 { 2706 struct net_device *dev_out = NULL; 2707 int orig_oif = fl4->flowi4_oif; 2708 unsigned int flags = 0; 2709 struct rtable *rth; 2710 int err; 2711 2712 if (fl4->saddr) { 2713 if (ipv4_is_multicast(fl4->saddr) || 2714 ipv4_is_lbcast(fl4->saddr)) { 2715 rth = ERR_PTR(-EINVAL); 2716 goto out; 2717 } 2718 2719 rth = ERR_PTR(-ENETUNREACH); 2720 2721 /* I removed check for oif == dev_out->oif here. 2722 * It was wrong for two reasons: 2723 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2724 * is assigned to multiple interfaces. 2725 * 2. Moreover, we are allowed to send packets with saddr 2726 * of another iface. --ANK 2727 */ 2728 2729 if (fl4->flowi4_oif == 0 && 2730 (ipv4_is_multicast(fl4->daddr) || 2731 ipv4_is_lbcast(fl4->daddr))) { 2732 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2733 dev_out = __ip_dev_find(net, fl4->saddr, false); 2734 if (!dev_out) 2735 goto out; 2736 2737 /* Special hack: user can direct multicasts 2738 * and limited broadcast via necessary interface 2739 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2740 * This hack is not just for fun, it allows 2741 * vic,vat and friends to work. 2742 * They bind socket to loopback, set ttl to zero 2743 * and expect that it will work. 2744 * From the viewpoint of routing cache they are broken, 2745 * because we are not allowed to build multicast path 2746 * with loopback source addr (look, routing cache 2747 * cannot know, that ttl is zero, so that packet 2748 * will not leave this host and route is valid). 2749 * Luckily, this hack is good workaround. 2750 */ 2751 2752 fl4->flowi4_oif = dev_out->ifindex; 2753 goto make_route; 2754 } 2755 2756 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2757 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2758 if (!__ip_dev_find(net, fl4->saddr, false)) 2759 goto out; 2760 } 2761 } 2762 2763 2764 if (fl4->flowi4_oif) { 2765 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2766 rth = ERR_PTR(-ENODEV); 2767 if (!dev_out) 2768 goto out; 2769 2770 /* RACE: Check return value of inet_select_addr instead. */ 2771 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2772 rth = ERR_PTR(-ENETUNREACH); 2773 goto out; 2774 } 2775 if (ipv4_is_local_multicast(fl4->daddr) || 2776 ipv4_is_lbcast(fl4->daddr) || 2777 fl4->flowi4_proto == IPPROTO_IGMP) { 2778 if (!fl4->saddr) 2779 fl4->saddr = inet_select_addr(dev_out, 0, 2780 RT_SCOPE_LINK); 2781 goto make_route; 2782 } 2783 if (!fl4->saddr) { 2784 if (ipv4_is_multicast(fl4->daddr)) 2785 fl4->saddr = inet_select_addr(dev_out, 0, 2786 fl4->flowi4_scope); 2787 else if (!fl4->daddr) 2788 fl4->saddr = inet_select_addr(dev_out, 0, 2789 RT_SCOPE_HOST); 2790 } 2791 } 2792 2793 if (!fl4->daddr) { 2794 fl4->daddr = fl4->saddr; 2795 if (!fl4->daddr) 2796 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2797 dev_out = net->loopback_dev; 2798 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2799 res->type = RTN_LOCAL; 2800 flags |= RTCF_LOCAL; 2801 goto make_route; 2802 } 2803 2804 err = fib_lookup(net, fl4, res, 0); 2805 if (err) { 2806 res->fi = NULL; 2807 res->table = NULL; 2808 if (fl4->flowi4_oif && 2809 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) { 2810 /* Apparently, routing tables are wrong. Assume, 2811 * that the destination is on link. 2812 * 2813 * WHY? DW. 2814 * Because we are allowed to send to iface 2815 * even if it has NO routes and NO assigned 2816 * addresses. When oif is specified, routing 2817 * tables are looked up with only one purpose: 2818 * to catch if destination is gatewayed, rather than 2819 * direct. Moreover, if MSG_DONTROUTE is set, 2820 * we send packet, ignoring both routing tables 2821 * and ifaddr state. --ANK 2822 * 2823 * 2824 * We could make it even if oif is unknown, 2825 * likely IPv6, but we do not. 2826 */ 2827 2828 if (fl4->saddr == 0) 2829 fl4->saddr = inet_select_addr(dev_out, 0, 2830 RT_SCOPE_LINK); 2831 res->type = RTN_UNICAST; 2832 goto make_route; 2833 } 2834 rth = ERR_PTR(err); 2835 goto out; 2836 } 2837 2838 if (res->type == RTN_LOCAL) { 2839 if (!fl4->saddr) { 2840 if (res->fi->fib_prefsrc) 2841 fl4->saddr = res->fi->fib_prefsrc; 2842 else 2843 fl4->saddr = fl4->daddr; 2844 } 2845 2846 /* L3 master device is the loopback for that domain */ 2847 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2848 net->loopback_dev; 2849 2850 /* make sure orig_oif points to fib result device even 2851 * though packet rx/tx happens over loopback or l3mdev 2852 */ 2853 orig_oif = FIB_RES_OIF(*res); 2854 2855 fl4->flowi4_oif = dev_out->ifindex; 2856 flags |= RTCF_LOCAL; 2857 goto make_route; 2858 } 2859 2860 fib_select_path(net, res, fl4, skb); 2861 2862 dev_out = FIB_RES_DEV(*res); 2863 2864 make_route: 2865 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2866 2867 out: 2868 return rth; 2869 } 2870 2871 static struct dst_ops ipv4_dst_blackhole_ops = { 2872 .family = AF_INET, 2873 .default_advmss = ipv4_default_advmss, 2874 .neigh_lookup = ipv4_neigh_lookup, 2875 .check = dst_blackhole_check, 2876 .cow_metrics = dst_blackhole_cow_metrics, 2877 .update_pmtu = dst_blackhole_update_pmtu, 2878 .redirect = dst_blackhole_redirect, 2879 .mtu = dst_blackhole_mtu, 2880 }; 2881 2882 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2883 { 2884 struct rtable *ort = dst_rtable(dst_orig); 2885 struct rtable *rt; 2886 2887 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0); 2888 if (rt) { 2889 struct dst_entry *new = &rt->dst; 2890 2891 new->__use = 1; 2892 new->input = dst_discard; 2893 new->output = dst_discard_out; 2894 2895 new->dev = net->loopback_dev; 2896 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC); 2897 2898 rt->rt_is_input = ort->rt_is_input; 2899 rt->rt_iif = ort->rt_iif; 2900 rt->rt_pmtu = ort->rt_pmtu; 2901 rt->rt_mtu_locked = ort->rt_mtu_locked; 2902 2903 rt->rt_genid = rt_genid_ipv4(net); 2904 rt->rt_flags = ort->rt_flags; 2905 rt->rt_type = ort->rt_type; 2906 rt->rt_uses_gateway = ort->rt_uses_gateway; 2907 rt->rt_gw_family = ort->rt_gw_family; 2908 if (rt->rt_gw_family == AF_INET) 2909 rt->rt_gw4 = ort->rt_gw4; 2910 else if (rt->rt_gw_family == AF_INET6) 2911 rt->rt_gw6 = ort->rt_gw6; 2912 } 2913 2914 dst_release(dst_orig); 2915 2916 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2917 } 2918 2919 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2920 const struct sock *sk) 2921 { 2922 struct rtable *rt = __ip_route_output_key(net, flp4); 2923 2924 if (IS_ERR(rt)) 2925 return rt; 2926 2927 if (flp4->flowi4_proto) { 2928 flp4->flowi4_oif = rt->dst.dev->ifindex; 2929 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst, 2930 flowi4_to_flowi(flp4), 2931 sk, 0)); 2932 } 2933 2934 return rt; 2935 } 2936 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2937 2938 /* called with rcu_read_lock held */ 2939 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2940 struct rtable *rt, u32 table_id, dscp_t dscp, 2941 struct flowi4 *fl4, struct sk_buff *skb, u32 portid, 2942 u32 seq, unsigned int flags) 2943 { 2944 struct rtmsg *r; 2945 struct nlmsghdr *nlh; 2946 unsigned long expires = 0; 2947 u32 error; 2948 u32 metrics[RTAX_MAX]; 2949 2950 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags); 2951 if (!nlh) 2952 return -EMSGSIZE; 2953 2954 r = nlmsg_data(nlh); 2955 r->rtm_family = AF_INET; 2956 r->rtm_dst_len = 32; 2957 r->rtm_src_len = 0; 2958 r->rtm_tos = inet_dscp_to_dsfield(dscp); 2959 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2960 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2961 goto nla_put_failure; 2962 r->rtm_type = rt->rt_type; 2963 r->rtm_scope = RT_SCOPE_UNIVERSE; 2964 r->rtm_protocol = RTPROT_UNSPEC; 2965 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2966 if (rt->rt_flags & RTCF_NOTIFY) 2967 r->rtm_flags |= RTM_F_NOTIFY; 2968 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2969 r->rtm_flags |= RTCF_DOREDIRECT; 2970 2971 if (nla_put_in_addr(skb, RTA_DST, dst)) 2972 goto nla_put_failure; 2973 if (src) { 2974 r->rtm_src_len = 32; 2975 if (nla_put_in_addr(skb, RTA_SRC, src)) 2976 goto nla_put_failure; 2977 } 2978 if (rt->dst.dev && 2979 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2980 goto nla_put_failure; 2981 if (lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 2982 goto nla_put_failure; 2983 #ifdef CONFIG_IP_ROUTE_CLASSID 2984 if (rt->dst.tclassid && 2985 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2986 goto nla_put_failure; 2987 #endif 2988 if (fl4 && !rt_is_input_route(rt) && 2989 fl4->saddr != src) { 2990 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2991 goto nla_put_failure; 2992 } 2993 if (rt->rt_uses_gateway) { 2994 if (rt->rt_gw_family == AF_INET && 2995 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2996 goto nla_put_failure; 2997 } else if (rt->rt_gw_family == AF_INET6) { 2998 int alen = sizeof(struct in6_addr); 2999 struct nlattr *nla; 3000 struct rtvia *via; 3001 3002 nla = nla_reserve(skb, RTA_VIA, alen + 2); 3003 if (!nla) 3004 goto nla_put_failure; 3005 3006 via = nla_data(nla); 3007 via->rtvia_family = AF_INET6; 3008 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 3009 } 3010 } 3011 3012 expires = rt->dst.expires; 3013 if (expires) { 3014 unsigned long now = jiffies; 3015 3016 if (time_before(now, expires)) 3017 expires -= now; 3018 else 3019 expires = 0; 3020 } 3021 3022 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3023 if (rt->rt_pmtu && expires) 3024 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 3025 if (rt->rt_mtu_locked && expires) 3026 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 3027 if (rtnetlink_put_metrics(skb, metrics) < 0) 3028 goto nla_put_failure; 3029 3030 if (fl4) { 3031 if (fl4->flowi4_mark && 3032 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 3033 goto nla_put_failure; 3034 3035 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 3036 nla_put_u32(skb, RTA_UID, 3037 from_kuid_munged(current_user_ns(), 3038 fl4->flowi4_uid))) 3039 goto nla_put_failure; 3040 3041 if (rt_is_input_route(rt)) { 3042 #ifdef CONFIG_IP_MROUTE 3043 if (ipv4_is_multicast(dst) && 3044 !ipv4_is_local_multicast(dst) && 3045 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) { 3046 int err = ipmr_get_route(net, skb, 3047 fl4->saddr, fl4->daddr, 3048 r, portid); 3049 3050 if (err <= 0) { 3051 if (err == 0) 3052 return 0; 3053 goto nla_put_failure; 3054 } 3055 } else 3056 #endif 3057 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 3058 goto nla_put_failure; 3059 } 3060 } 3061 3062 error = rt->dst.error; 3063 3064 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 3065 goto nla_put_failure; 3066 3067 nlmsg_end(skb, nlh); 3068 return 0; 3069 3070 nla_put_failure: 3071 nlmsg_cancel(skb, nlh); 3072 return -EMSGSIZE; 3073 } 3074 3075 static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb, 3076 struct netlink_callback *cb, u32 table_id, 3077 struct fnhe_hash_bucket *bucket, int genid, 3078 int *fa_index, int fa_start, unsigned int flags) 3079 { 3080 int i; 3081 3082 for (i = 0; i < FNHE_HASH_SIZE; i++) { 3083 struct fib_nh_exception *fnhe; 3084 3085 for (fnhe = rcu_dereference(bucket[i].chain); fnhe; 3086 fnhe = rcu_dereference(fnhe->fnhe_next)) { 3087 struct rtable *rt; 3088 int err; 3089 3090 if (*fa_index < fa_start) 3091 goto next; 3092 3093 if (fnhe->fnhe_genid != genid) 3094 goto next; 3095 3096 if (fnhe->fnhe_expires && 3097 time_after(jiffies, fnhe->fnhe_expires)) 3098 goto next; 3099 3100 rt = rcu_dereference(fnhe->fnhe_rth_input); 3101 if (!rt) 3102 rt = rcu_dereference(fnhe->fnhe_rth_output); 3103 if (!rt) 3104 goto next; 3105 3106 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt, 3107 table_id, 0, NULL, skb, 3108 NETLINK_CB(cb->skb).portid, 3109 cb->nlh->nlmsg_seq, flags); 3110 if (err) 3111 return err; 3112 next: 3113 (*fa_index)++; 3114 } 3115 } 3116 3117 return 0; 3118 } 3119 3120 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, 3121 u32 table_id, struct fib_info *fi, 3122 int *fa_index, int fa_start, unsigned int flags) 3123 { 3124 struct net *net = sock_net(cb->skb->sk); 3125 int nhsel, genid = fnhe_genid(net); 3126 3127 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 3128 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel); 3129 struct fnhe_hash_bucket *bucket; 3130 int err; 3131 3132 if (nhc->nhc_flags & RTNH_F_DEAD) 3133 continue; 3134 3135 rcu_read_lock(); 3136 bucket = rcu_dereference(nhc->nhc_exceptions); 3137 err = 0; 3138 if (bucket) 3139 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket, 3140 genid, fa_index, fa_start, 3141 flags); 3142 rcu_read_unlock(); 3143 if (err) 3144 return err; 3145 } 3146 3147 return 0; 3148 } 3149 3150 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 3151 u8 ip_proto, __be16 sport, 3152 __be16 dport) 3153 { 3154 struct sk_buff *skb; 3155 struct iphdr *iph; 3156 3157 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3158 if (!skb) 3159 return NULL; 3160 3161 /* Reserve room for dummy headers, this skb can pass 3162 * through good chunk of routing engine. 3163 */ 3164 skb_reset_mac_header(skb); 3165 skb_reset_network_header(skb); 3166 skb->protocol = htons(ETH_P_IP); 3167 iph = skb_put(skb, sizeof(struct iphdr)); 3168 iph->protocol = ip_proto; 3169 iph->saddr = src; 3170 iph->daddr = dst; 3171 iph->version = 0x4; 3172 iph->frag_off = 0; 3173 iph->ihl = 0x5; 3174 skb_set_transport_header(skb, skb->len); 3175 3176 switch (iph->protocol) { 3177 case IPPROTO_UDP: { 3178 struct udphdr *udph; 3179 3180 udph = skb_put_zero(skb, sizeof(struct udphdr)); 3181 udph->source = sport; 3182 udph->dest = dport; 3183 udph->len = htons(sizeof(struct udphdr)); 3184 udph->check = 0; 3185 break; 3186 } 3187 case IPPROTO_TCP: { 3188 struct tcphdr *tcph; 3189 3190 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 3191 tcph->source = sport; 3192 tcph->dest = dport; 3193 tcph->doff = sizeof(struct tcphdr) / 4; 3194 tcph->rst = 1; 3195 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 3196 src, dst, 0); 3197 break; 3198 } 3199 case IPPROTO_ICMP: { 3200 struct icmphdr *icmph; 3201 3202 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 3203 icmph->type = ICMP_ECHO; 3204 icmph->code = 0; 3205 } 3206 } 3207 3208 return skb; 3209 } 3210 3211 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 3212 const struct nlmsghdr *nlh, 3213 struct nlattr **tb, 3214 struct netlink_ext_ack *extack) 3215 { 3216 struct rtmsg *rtm; 3217 int i, err; 3218 3219 rtm = nlmsg_payload(nlh, sizeof(*rtm)); 3220 if (!rtm) { 3221 NL_SET_ERR_MSG(extack, 3222 "ipv4: Invalid header for route get request"); 3223 return -EINVAL; 3224 } 3225 3226 if (!netlink_strict_get_check(skb)) 3227 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 3228 rtm_ipv4_policy, extack); 3229 3230 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 3231 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 3232 rtm->rtm_table || rtm->rtm_protocol || 3233 rtm->rtm_scope || rtm->rtm_type) { 3234 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 3235 return -EINVAL; 3236 } 3237 3238 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 3239 RTM_F_LOOKUP_TABLE | 3240 RTM_F_FIB_MATCH)) { 3241 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 3242 return -EINVAL; 3243 } 3244 3245 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 3246 rtm_ipv4_policy, extack); 3247 if (err) 3248 return err; 3249 3250 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 3251 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 3252 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 3253 return -EINVAL; 3254 } 3255 3256 for (i = 0; i <= RTA_MAX; i++) { 3257 if (!tb[i]) 3258 continue; 3259 3260 switch (i) { 3261 case RTA_IIF: 3262 case RTA_OIF: 3263 case RTA_SRC: 3264 case RTA_DST: 3265 case RTA_IP_PROTO: 3266 case RTA_SPORT: 3267 case RTA_DPORT: 3268 case RTA_MARK: 3269 case RTA_UID: 3270 break; 3271 default: 3272 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 3273 return -EINVAL; 3274 } 3275 } 3276 3277 return 0; 3278 } 3279 3280 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 3281 struct netlink_ext_ack *extack) 3282 { 3283 struct net *net = sock_net(in_skb->sk); 3284 struct nlattr *tb[RTA_MAX+1]; 3285 u32 table_id = RT_TABLE_MAIN; 3286 __be16 sport = 0, dport = 0; 3287 struct fib_result res = {}; 3288 u8 ip_proto = IPPROTO_UDP; 3289 struct rtable *rt = NULL; 3290 struct sk_buff *skb; 3291 struct rtmsg *rtm; 3292 struct flowi4 fl4 = {}; 3293 __be32 dst = 0; 3294 __be32 src = 0; 3295 dscp_t dscp; 3296 kuid_t uid; 3297 u32 iif; 3298 int err; 3299 int mark; 3300 3301 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 3302 if (err < 0) 3303 return err; 3304 3305 rtm = nlmsg_data(nlh); 3306 src = nla_get_in_addr_default(tb[RTA_SRC], 0); 3307 dst = nla_get_in_addr_default(tb[RTA_DST], 0); 3308 iif = nla_get_u32_default(tb[RTA_IIF], 0); 3309 mark = nla_get_u32_default(tb[RTA_MARK], 0); 3310 dscp = inet_dsfield_to_dscp(rtm->rtm_tos); 3311 if (tb[RTA_UID]) 3312 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 3313 else 3314 uid = (iif ? INVALID_UID : current_uid()); 3315 3316 if (tb[RTA_IP_PROTO]) { 3317 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 3318 &ip_proto, AF_INET, extack); 3319 if (err) 3320 return err; 3321 } 3322 3323 if (tb[RTA_SPORT]) 3324 sport = nla_get_be16(tb[RTA_SPORT]); 3325 3326 if (tb[RTA_DPORT]) 3327 dport = nla_get_be16(tb[RTA_DPORT]); 3328 3329 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 3330 if (!skb) 3331 return -ENOBUFS; 3332 3333 fl4.daddr = dst; 3334 fl4.saddr = src; 3335 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp); 3336 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0); 3337 fl4.flowi4_mark = mark; 3338 fl4.flowi4_uid = uid; 3339 if (sport) 3340 fl4.fl4_sport = sport; 3341 if (dport) 3342 fl4.fl4_dport = dport; 3343 fl4.flowi4_proto = ip_proto; 3344 3345 rcu_read_lock(); 3346 3347 if (iif) { 3348 struct net_device *dev; 3349 3350 dev = dev_get_by_index_rcu(net, iif); 3351 if (!dev) { 3352 err = -ENODEV; 3353 goto errout_rcu; 3354 } 3355 3356 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3357 skb->dev = dev; 3358 skb->mark = mark; 3359 err = ip_route_input_rcu(skb, dst, src, dscp, dev, 3360 &res) ? -EINVAL : 0; 3361 3362 rt = skb_rtable(skb); 3363 if (err == 0 && rt->dst.error) 3364 err = -rt->dst.error; 3365 } else { 3366 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3367 skb->dev = net->loopback_dev; 3368 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3369 err = 0; 3370 if (IS_ERR(rt)) 3371 err = PTR_ERR(rt); 3372 else 3373 skb_dst_set(skb, &rt->dst); 3374 } 3375 3376 if (err) 3377 goto errout_rcu; 3378 3379 if (rtm->rtm_flags & RTM_F_NOTIFY) 3380 rt->rt_flags |= RTCF_NOTIFY; 3381 3382 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3383 table_id = res.table ? res.table->tb_id : 0; 3384 3385 /* reset skb for netlink reply msg */ 3386 skb_trim(skb, 0); 3387 skb_reset_network_header(skb); 3388 skb_reset_transport_header(skb); 3389 skb_reset_mac_header(skb); 3390 3391 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3392 struct fib_rt_info fri; 3393 3394 if (!res.fi) { 3395 err = fib_props[res.type].error; 3396 if (!err) 3397 err = -EHOSTUNREACH; 3398 goto errout_rcu; 3399 } 3400 fri.fi = res.fi; 3401 fri.tb_id = table_id; 3402 fri.dst = res.prefix; 3403 fri.dst_len = res.prefixlen; 3404 fri.dscp = res.dscp; 3405 fri.type = rt->rt_type; 3406 fri.offload = 0; 3407 fri.trap = 0; 3408 fri.offload_failed = 0; 3409 if (res.fa_head) { 3410 struct fib_alias *fa; 3411 3412 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) { 3413 u8 slen = 32 - fri.dst_len; 3414 3415 if (fa->fa_slen == slen && 3416 fa->tb_id == fri.tb_id && 3417 fa->fa_dscp == fri.dscp && 3418 fa->fa_info == res.fi && 3419 fa->fa_type == fri.type) { 3420 fri.offload = READ_ONCE(fa->offload); 3421 fri.trap = READ_ONCE(fa->trap); 3422 fri.offload_failed = 3423 READ_ONCE(fa->offload_failed); 3424 break; 3425 } 3426 } 3427 } 3428 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3429 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0); 3430 } else { 3431 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4, 3432 skb, NETLINK_CB(in_skb).portid, 3433 nlh->nlmsg_seq, 0); 3434 } 3435 if (err < 0) 3436 goto errout_rcu; 3437 3438 rcu_read_unlock(); 3439 3440 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3441 3442 errout_free: 3443 return err; 3444 errout_rcu: 3445 rcu_read_unlock(); 3446 kfree_skb(skb); 3447 goto errout_free; 3448 } 3449 3450 void ip_rt_multicast_event(struct in_device *in_dev) 3451 { 3452 rt_cache_flush(dev_net(in_dev->dev)); 3453 } 3454 3455 #ifdef CONFIG_SYSCTL 3456 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3457 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3458 static int ip_rt_gc_elasticity __read_mostly = 8; 3459 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3460 3461 static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write, 3462 void *buffer, size_t *lenp, loff_t *ppos) 3463 { 3464 struct net *net = (struct net *)__ctl->extra1; 3465 3466 if (write) { 3467 rt_cache_flush(net); 3468 fnhe_genid_bump(net); 3469 return 0; 3470 } 3471 3472 return -EINVAL; 3473 } 3474 3475 static struct ctl_table ipv4_route_table[] = { 3476 { 3477 .procname = "gc_thresh", 3478 .data = &ipv4_dst_ops.gc_thresh, 3479 .maxlen = sizeof(int), 3480 .mode = 0644, 3481 .proc_handler = proc_dointvec, 3482 }, 3483 { 3484 .procname = "max_size", 3485 .data = &ip_rt_max_size, 3486 .maxlen = sizeof(int), 3487 .mode = 0644, 3488 .proc_handler = proc_dointvec, 3489 }, 3490 { 3491 /* Deprecated. Use gc_min_interval_ms */ 3492 3493 .procname = "gc_min_interval", 3494 .data = &ip_rt_gc_min_interval, 3495 .maxlen = sizeof(int), 3496 .mode = 0644, 3497 .proc_handler = proc_dointvec_jiffies, 3498 }, 3499 { 3500 .procname = "gc_min_interval_ms", 3501 .data = &ip_rt_gc_min_interval, 3502 .maxlen = sizeof(int), 3503 .mode = 0644, 3504 .proc_handler = proc_dointvec_ms_jiffies, 3505 }, 3506 { 3507 .procname = "gc_timeout", 3508 .data = &ip_rt_gc_timeout, 3509 .maxlen = sizeof(int), 3510 .mode = 0644, 3511 .proc_handler = proc_dointvec_jiffies, 3512 }, 3513 { 3514 .procname = "gc_interval", 3515 .data = &ip_rt_gc_interval, 3516 .maxlen = sizeof(int), 3517 .mode = 0644, 3518 .proc_handler = proc_dointvec_jiffies, 3519 }, 3520 { 3521 .procname = "redirect_load", 3522 .data = &ip_rt_redirect_load, 3523 .maxlen = sizeof(int), 3524 .mode = 0644, 3525 .proc_handler = proc_dointvec, 3526 }, 3527 { 3528 .procname = "redirect_number", 3529 .data = &ip_rt_redirect_number, 3530 .maxlen = sizeof(int), 3531 .mode = 0644, 3532 .proc_handler = proc_dointvec, 3533 }, 3534 { 3535 .procname = "redirect_silence", 3536 .data = &ip_rt_redirect_silence, 3537 .maxlen = sizeof(int), 3538 .mode = 0644, 3539 .proc_handler = proc_dointvec, 3540 }, 3541 { 3542 .procname = "error_cost", 3543 .data = &ip_rt_error_cost, 3544 .maxlen = sizeof(int), 3545 .mode = 0644, 3546 .proc_handler = proc_dointvec, 3547 }, 3548 { 3549 .procname = "error_burst", 3550 .data = &ip_rt_error_burst, 3551 .maxlen = sizeof(int), 3552 .mode = 0644, 3553 .proc_handler = proc_dointvec, 3554 }, 3555 { 3556 .procname = "gc_elasticity", 3557 .data = &ip_rt_gc_elasticity, 3558 .maxlen = sizeof(int), 3559 .mode = 0644, 3560 .proc_handler = proc_dointvec, 3561 }, 3562 }; 3563 3564 static const char ipv4_route_flush_procname[] = "flush"; 3565 3566 static struct ctl_table ipv4_route_netns_table[] = { 3567 { 3568 .procname = ipv4_route_flush_procname, 3569 .maxlen = sizeof(int), 3570 .mode = 0200, 3571 .proc_handler = ipv4_sysctl_rtcache_flush, 3572 }, 3573 { 3574 .procname = "min_pmtu", 3575 .data = &init_net.ipv4.ip_rt_min_pmtu, 3576 .maxlen = sizeof(int), 3577 .mode = 0644, 3578 .proc_handler = proc_dointvec_minmax, 3579 .extra1 = &ip_min_valid_pmtu, 3580 }, 3581 { 3582 .procname = "mtu_expires", 3583 .data = &init_net.ipv4.ip_rt_mtu_expires, 3584 .maxlen = sizeof(int), 3585 .mode = 0644, 3586 .proc_handler = proc_dointvec_jiffies, 3587 }, 3588 { 3589 .procname = "min_adv_mss", 3590 .data = &init_net.ipv4.ip_rt_min_advmss, 3591 .maxlen = sizeof(int), 3592 .mode = 0644, 3593 .proc_handler = proc_dointvec, 3594 }, 3595 }; 3596 3597 static __net_init int sysctl_route_net_init(struct net *net) 3598 { 3599 struct ctl_table *tbl; 3600 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table); 3601 3602 tbl = ipv4_route_netns_table; 3603 if (!net_eq(net, &init_net)) { 3604 int i; 3605 3606 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL); 3607 if (!tbl) 3608 goto err_dup; 3609 3610 /* Don't export non-whitelisted sysctls to unprivileged users */ 3611 if (net->user_ns != &init_user_ns) { 3612 if (tbl[0].procname != ipv4_route_flush_procname) 3613 table_size = 0; 3614 } 3615 3616 /* Update the variables to point into the current struct net 3617 * except for the first element flush 3618 */ 3619 for (i = 1; i < table_size; i++) 3620 tbl[i].data += (void *)net - (void *)&init_net; 3621 } 3622 tbl[0].extra1 = net; 3623 3624 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route", 3625 tbl, table_size); 3626 if (!net->ipv4.route_hdr) 3627 goto err_reg; 3628 return 0; 3629 3630 err_reg: 3631 if (tbl != ipv4_route_netns_table) 3632 kfree(tbl); 3633 err_dup: 3634 return -ENOMEM; 3635 } 3636 3637 static __net_exit void sysctl_route_net_exit(struct net *net) 3638 { 3639 const struct ctl_table *tbl; 3640 3641 tbl = net->ipv4.route_hdr->ctl_table_arg; 3642 unregister_net_sysctl_table(net->ipv4.route_hdr); 3643 BUG_ON(tbl == ipv4_route_netns_table); 3644 kfree(tbl); 3645 } 3646 3647 static __net_initdata struct pernet_operations sysctl_route_ops = { 3648 .init = sysctl_route_net_init, 3649 .exit = sysctl_route_net_exit, 3650 }; 3651 #endif 3652 3653 static __net_init int netns_ip_rt_init(struct net *net) 3654 { 3655 /* Set default value for namespaceified sysctls */ 3656 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU; 3657 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES; 3658 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS; 3659 return 0; 3660 } 3661 3662 static struct pernet_operations __net_initdata ip_rt_ops = { 3663 .init = netns_ip_rt_init, 3664 }; 3665 3666 static __net_init int rt_genid_init(struct net *net) 3667 { 3668 atomic_set(&net->ipv4.rt_genid, 0); 3669 atomic_set(&net->fnhe_genid, 0); 3670 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32()); 3671 return 0; 3672 } 3673 3674 static __net_initdata struct pernet_operations rt_genid_ops = { 3675 .init = rt_genid_init, 3676 }; 3677 3678 static int __net_init ipv4_inetpeer_init(struct net *net) 3679 { 3680 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3681 3682 if (!bp) 3683 return -ENOMEM; 3684 inet_peer_base_init(bp); 3685 net->ipv4.peers = bp; 3686 return 0; 3687 } 3688 3689 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3690 { 3691 struct inet_peer_base *bp = net->ipv4.peers; 3692 3693 net->ipv4.peers = NULL; 3694 inetpeer_invalidate_tree(bp); 3695 kfree(bp); 3696 } 3697 3698 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3699 .init = ipv4_inetpeer_init, 3700 .exit = ipv4_inetpeer_exit, 3701 }; 3702 3703 #ifdef CONFIG_IP_ROUTE_CLASSID 3704 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3705 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3706 3707 static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = { 3708 {.protocol = PF_INET, .msgtype = RTM_GETROUTE, 3709 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED}, 3710 }; 3711 3712 int __init ip_rt_init(void) 3713 { 3714 void *idents_hash; 3715 int cpu; 3716 3717 /* For modern hosts, this will use 2 MB of memory */ 3718 idents_hash = alloc_large_system_hash("IP idents", 3719 sizeof(*ip_idents) + sizeof(*ip_tstamps), 3720 0, 3721 16, /* one bucket per 64 KB */ 3722 HASH_ZERO, 3723 NULL, 3724 &ip_idents_mask, 3725 2048, 3726 256*1024); 3727 3728 ip_idents = idents_hash; 3729 3730 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents)); 3731 3732 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents); 3733 3734 for_each_possible_cpu(cpu) { 3735 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3736 3737 INIT_LIST_HEAD(&ul->head); 3738 spin_lock_init(&ul->lock); 3739 } 3740 #ifdef CONFIG_IP_ROUTE_CLASSID 3741 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3742 if (!ip_rt_acct) 3743 panic("IP: failed to allocate ip_rt_acct\n"); 3744 #endif 3745 3746 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable, 3747 SLAB_HWCACHE_ALIGN | SLAB_PANIC); 3748 3749 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3750 3751 if (dst_entries_init(&ipv4_dst_ops) < 0) 3752 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3753 3754 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3755 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3756 3757 ipv4_dst_ops.gc_thresh = ~0; 3758 ip_rt_max_size = INT_MAX; 3759 3760 devinet_init(); 3761 ip_fib_init(); 3762 3763 if (ip_rt_proc_init()) 3764 pr_err("Unable to create route proc files\n"); 3765 #ifdef CONFIG_XFRM 3766 xfrm_init(); 3767 xfrm4_init(); 3768 #endif 3769 rtnl_register_many(ip_rt_rtnl_msg_handlers); 3770 3771 #ifdef CONFIG_SYSCTL 3772 register_pernet_subsys(&sysctl_route_ops); 3773 #endif 3774 register_pernet_subsys(&ip_rt_ops); 3775 register_pernet_subsys(&rt_genid_ops); 3776 register_pernet_subsys(&ipv4_inetpeer_ops); 3777 return 0; 3778 } 3779 3780 #ifdef CONFIG_SYSCTL 3781 /* 3782 * We really need to sanitize the damn ipv4 init order, then all 3783 * this nonsense will go away. 3784 */ 3785 void __init ip_static_sysctl_init(void) 3786 { 3787 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3788 } 3789 #endif 3790