1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * ROUTE - implementation of the IP router. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 13 * 14 * Fixes: 15 * Alan Cox : Verify area fixes. 16 * Alan Cox : cli() protects routing changes 17 * Rui Oliveira : ICMP routing table updates 18 * (rco@di.uminho.pt) Routing table insertion and update 19 * Linus Torvalds : Rewrote bits to be sensible 20 * Alan Cox : Added BSD route gw semantics 21 * Alan Cox : Super /proc >4K 22 * Alan Cox : MTU in route table 23 * Alan Cox : MSS actually. Also added the window 24 * clamper. 25 * Sam Lantinga : Fixed route matching in rt_del() 26 * Alan Cox : Routing cache support. 27 * Alan Cox : Removed compatibility cruft. 28 * Alan Cox : RTF_REJECT support. 29 * Alan Cox : TCP irtt support. 30 * Jonathan Naylor : Added Metric support. 31 * Miquel van Smoorenburg : BSD API fixes. 32 * Miquel van Smoorenburg : Metrics. 33 * Alan Cox : Use __u32 properly 34 * Alan Cox : Aligned routing errors more closely with BSD 35 * our system is still very different. 36 * Alan Cox : Faster /proc handling 37 * Alexey Kuznetsov : Massive rework to support tree based routing, 38 * routing caches and better behaviour. 39 * 40 * Olaf Erb : irtt wasn't being copied right. 41 * Bjorn Ekwall : Kerneld route support. 42 * Alan Cox : Multicast fixed (I hope) 43 * Pavel Krauz : Limited broadcast fixed 44 * Mike McLagan : Routing by source 45 * Alexey Kuznetsov : End of old history. Split to fib.c and 46 * route.c and rewritten from scratch. 47 * Andi Kleen : Load-limit warning messages. 48 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 52 * Marc Boucher : routing by fwmark 53 * Robert Olsson : Added rt_cache statistics 54 * Arnaldo C. Melo : Convert proc stuff to seq_file 55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 57 * Ilia Sotnikov : Removed TOS from hash calculations 58 * 59 * This program is free software; you can redistribute it and/or 60 * modify it under the terms of the GNU General Public License 61 * as published by the Free Software Foundation; either version 62 * 2 of the License, or (at your option) any later version. 63 */ 64 65 #define pr_fmt(fmt) "IPv4: " fmt 66 67 #include <linux/module.h> 68 #include <linux/uaccess.h> 69 #include <linux/bitops.h> 70 #include <linux/types.h> 71 #include <linux/kernel.h> 72 #include <linux/mm.h> 73 #include <linux/string.h> 74 #include <linux/socket.h> 75 #include <linux/sockios.h> 76 #include <linux/errno.h> 77 #include <linux/in.h> 78 #include <linux/inet.h> 79 #include <linux/netdevice.h> 80 #include <linux/proc_fs.h> 81 #include <linux/init.h> 82 #include <linux/skbuff.h> 83 #include <linux/inetdevice.h> 84 #include <linux/igmp.h> 85 #include <linux/pkt_sched.h> 86 #include <linux/mroute.h> 87 #include <linux/netfilter_ipv4.h> 88 #include <linux/random.h> 89 #include <linux/rcupdate.h> 90 #include <linux/times.h> 91 #include <linux/slab.h> 92 #include <linux/jhash.h> 93 #include <net/dst.h> 94 #include <net/dst_metadata.h> 95 #include <net/net_namespace.h> 96 #include <net/protocol.h> 97 #include <net/ip.h> 98 #include <net/route.h> 99 #include <net/inetpeer.h> 100 #include <net/sock.h> 101 #include <net/ip_fib.h> 102 #include <net/arp.h> 103 #include <net/tcp.h> 104 #include <net/icmp.h> 105 #include <net/xfrm.h> 106 #include <net/lwtunnel.h> 107 #include <net/netevent.h> 108 #include <net/rtnetlink.h> 109 #ifdef CONFIG_SYSCTL 110 #include <linux/sysctl.h> 111 #endif 112 #include <net/secure_seq.h> 113 #include <net/ip_tunnels.h> 114 #include <net/l3mdev.h> 115 116 #include "fib_lookup.h" 117 118 #define RT_FL_TOS(oldflp4) \ 119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 120 121 #define RT_GC_TIMEOUT (300*HZ) 122 123 static int ip_rt_max_size; 124 static int ip_rt_redirect_number __read_mostly = 9; 125 static int ip_rt_redirect_load __read_mostly = HZ / 50; 126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 127 static int ip_rt_error_cost __read_mostly = HZ; 128 static int ip_rt_error_burst __read_mostly = 5 * HZ; 129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 130 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 131 static int ip_rt_min_advmss __read_mostly = 256; 132 133 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 134 135 /* 136 * Interface to generic destination cache. 137 */ 138 139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 141 static unsigned int ipv4_mtu(const struct dst_entry *dst); 142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 143 static void ipv4_link_failure(struct sk_buff *skb); 144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 145 struct sk_buff *skb, u32 mtu); 146 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 147 struct sk_buff *skb); 148 static void ipv4_dst_destroy(struct dst_entry *dst); 149 150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 151 { 152 WARN_ON(1); 153 return NULL; 154 } 155 156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 157 struct sk_buff *skb, 158 const void *daddr); 159 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 160 161 static struct dst_ops ipv4_dst_ops = { 162 .family = AF_INET, 163 .check = ipv4_dst_check, 164 .default_advmss = ipv4_default_advmss, 165 .mtu = ipv4_mtu, 166 .cow_metrics = ipv4_cow_metrics, 167 .destroy = ipv4_dst_destroy, 168 .negative_advice = ipv4_negative_advice, 169 .link_failure = ipv4_link_failure, 170 .update_pmtu = ip_rt_update_pmtu, 171 .redirect = ip_do_redirect, 172 .local_out = __ip_local_out, 173 .neigh_lookup = ipv4_neigh_lookup, 174 .confirm_neigh = ipv4_confirm_neigh, 175 }; 176 177 #define ECN_OR_COST(class) TC_PRIO_##class 178 179 const __u8 ip_tos2prio[16] = { 180 TC_PRIO_BESTEFFORT, 181 ECN_OR_COST(BESTEFFORT), 182 TC_PRIO_BESTEFFORT, 183 ECN_OR_COST(BESTEFFORT), 184 TC_PRIO_BULK, 185 ECN_OR_COST(BULK), 186 TC_PRIO_BULK, 187 ECN_OR_COST(BULK), 188 TC_PRIO_INTERACTIVE, 189 ECN_OR_COST(INTERACTIVE), 190 TC_PRIO_INTERACTIVE, 191 ECN_OR_COST(INTERACTIVE), 192 TC_PRIO_INTERACTIVE_BULK, 193 ECN_OR_COST(INTERACTIVE_BULK), 194 TC_PRIO_INTERACTIVE_BULK, 195 ECN_OR_COST(INTERACTIVE_BULK) 196 }; 197 EXPORT_SYMBOL(ip_tos2prio); 198 199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 200 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 201 202 #ifdef CONFIG_PROC_FS 203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 204 { 205 if (*pos) 206 return NULL; 207 return SEQ_START_TOKEN; 208 } 209 210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 211 { 212 ++*pos; 213 return NULL; 214 } 215 216 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 217 { 218 } 219 220 static int rt_cache_seq_show(struct seq_file *seq, void *v) 221 { 222 if (v == SEQ_START_TOKEN) 223 seq_printf(seq, "%-127s\n", 224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 226 "HHUptod\tSpecDst"); 227 return 0; 228 } 229 230 static const struct seq_operations rt_cache_seq_ops = { 231 .start = rt_cache_seq_start, 232 .next = rt_cache_seq_next, 233 .stop = rt_cache_seq_stop, 234 .show = rt_cache_seq_show, 235 }; 236 237 static int rt_cache_seq_open(struct inode *inode, struct file *file) 238 { 239 return seq_open(file, &rt_cache_seq_ops); 240 } 241 242 static const struct file_operations rt_cache_seq_fops = { 243 .open = rt_cache_seq_open, 244 .read = seq_read, 245 .llseek = seq_lseek, 246 .release = seq_release, 247 }; 248 249 250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 251 { 252 int cpu; 253 254 if (*pos == 0) 255 return SEQ_START_TOKEN; 256 257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 258 if (!cpu_possible(cpu)) 259 continue; 260 *pos = cpu+1; 261 return &per_cpu(rt_cache_stat, cpu); 262 } 263 return NULL; 264 } 265 266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 267 { 268 int cpu; 269 270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 271 if (!cpu_possible(cpu)) 272 continue; 273 *pos = cpu+1; 274 return &per_cpu(rt_cache_stat, cpu); 275 } 276 return NULL; 277 278 } 279 280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 281 { 282 283 } 284 285 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 286 { 287 struct rt_cache_stat *st = v; 288 289 if (v == SEQ_START_TOKEN) { 290 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n"); 291 return 0; 292 } 293 294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 296 dst_entries_get_slow(&ipv4_dst_ops), 297 0, /* st->in_hit */ 298 st->in_slow_tot, 299 st->in_slow_mc, 300 st->in_no_route, 301 st->in_brd, 302 st->in_martian_dst, 303 st->in_martian_src, 304 305 0, /* st->out_hit */ 306 st->out_slow_tot, 307 st->out_slow_mc, 308 309 0, /* st->gc_total */ 310 0, /* st->gc_ignored */ 311 0, /* st->gc_goal_miss */ 312 0, /* st->gc_dst_overflow */ 313 0, /* st->in_hlist_search */ 314 0 /* st->out_hlist_search */ 315 ); 316 return 0; 317 } 318 319 static const struct seq_operations rt_cpu_seq_ops = { 320 .start = rt_cpu_seq_start, 321 .next = rt_cpu_seq_next, 322 .stop = rt_cpu_seq_stop, 323 .show = rt_cpu_seq_show, 324 }; 325 326 327 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 328 { 329 return seq_open(file, &rt_cpu_seq_ops); 330 } 331 332 static const struct file_operations rt_cpu_seq_fops = { 333 .open = rt_cpu_seq_open, 334 .read = seq_read, 335 .llseek = seq_lseek, 336 .release = seq_release, 337 }; 338 339 #ifdef CONFIG_IP_ROUTE_CLASSID 340 static int rt_acct_proc_show(struct seq_file *m, void *v) 341 { 342 struct ip_rt_acct *dst, *src; 343 unsigned int i, j; 344 345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 346 if (!dst) 347 return -ENOMEM; 348 349 for_each_possible_cpu(i) { 350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 351 for (j = 0; j < 256; j++) { 352 dst[j].o_bytes += src[j].o_bytes; 353 dst[j].o_packets += src[j].o_packets; 354 dst[j].i_bytes += src[j].i_bytes; 355 dst[j].i_packets += src[j].i_packets; 356 } 357 } 358 359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 360 kfree(dst); 361 return 0; 362 } 363 #endif 364 365 static int __net_init ip_rt_do_proc_init(struct net *net) 366 { 367 struct proc_dir_entry *pde; 368 369 pde = proc_create("rt_cache", 0444, net->proc_net, 370 &rt_cache_seq_fops); 371 if (!pde) 372 goto err1; 373 374 pde = proc_create("rt_cache", 0444, 375 net->proc_net_stat, &rt_cpu_seq_fops); 376 if (!pde) 377 goto err2; 378 379 #ifdef CONFIG_IP_ROUTE_CLASSID 380 pde = proc_create_single("rt_acct", 0, net->proc_net, 381 rt_acct_proc_show); 382 if (!pde) 383 goto err3; 384 #endif 385 return 0; 386 387 #ifdef CONFIG_IP_ROUTE_CLASSID 388 err3: 389 remove_proc_entry("rt_cache", net->proc_net_stat); 390 #endif 391 err2: 392 remove_proc_entry("rt_cache", net->proc_net); 393 err1: 394 return -ENOMEM; 395 } 396 397 static void __net_exit ip_rt_do_proc_exit(struct net *net) 398 { 399 remove_proc_entry("rt_cache", net->proc_net_stat); 400 remove_proc_entry("rt_cache", net->proc_net); 401 #ifdef CONFIG_IP_ROUTE_CLASSID 402 remove_proc_entry("rt_acct", net->proc_net); 403 #endif 404 } 405 406 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 407 .init = ip_rt_do_proc_init, 408 .exit = ip_rt_do_proc_exit, 409 }; 410 411 static int __init ip_rt_proc_init(void) 412 { 413 return register_pernet_subsys(&ip_rt_proc_ops); 414 } 415 416 #else 417 static inline int ip_rt_proc_init(void) 418 { 419 return 0; 420 } 421 #endif /* CONFIG_PROC_FS */ 422 423 static inline bool rt_is_expired(const struct rtable *rth) 424 { 425 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 426 } 427 428 void rt_cache_flush(struct net *net) 429 { 430 rt_genid_bump_ipv4(net); 431 } 432 433 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 434 struct sk_buff *skb, 435 const void *daddr) 436 { 437 const struct rtable *rt = container_of(dst, struct rtable, dst); 438 struct net_device *dev = dst->dev; 439 struct neighbour *n; 440 441 rcu_read_lock_bh(); 442 443 if (likely(rt->rt_gw_family == AF_INET)) { 444 n = ip_neigh_gw4(dev, rt->rt_gw4); 445 } else if (rt->rt_gw_family == AF_INET6) { 446 n = ip_neigh_gw6(dev, &rt->rt_gw6); 447 } else { 448 __be32 pkey; 449 450 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 451 n = ip_neigh_gw4(dev, pkey); 452 } 453 454 if (n && !refcount_inc_not_zero(&n->refcnt)) 455 n = NULL; 456 457 rcu_read_unlock_bh(); 458 459 return n; 460 } 461 462 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 463 { 464 const struct rtable *rt = container_of(dst, struct rtable, dst); 465 struct net_device *dev = dst->dev; 466 const __be32 *pkey = daddr; 467 468 if (rt->rt_gw_family == AF_INET) { 469 pkey = (const __be32 *)&rt->rt_gw4; 470 } else if (rt->rt_gw_family == AF_INET6) { 471 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 472 } else if (!daddr || 473 (rt->rt_flags & 474 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 475 return; 476 } 477 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 478 } 479 480 #define IP_IDENTS_SZ 2048u 481 482 static atomic_t *ip_idents __read_mostly; 483 static u32 *ip_tstamps __read_mostly; 484 485 /* In order to protect privacy, we add a perturbation to identifiers 486 * if one generator is seldom used. This makes hard for an attacker 487 * to infer how many packets were sent between two points in time. 488 */ 489 u32 ip_idents_reserve(u32 hash, int segs) 490 { 491 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; 492 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; 493 u32 old = READ_ONCE(*p_tstamp); 494 u32 now = (u32)jiffies; 495 u32 new, delta = 0; 496 497 if (old != now && cmpxchg(p_tstamp, old, now) == old) 498 delta = prandom_u32_max(now - old); 499 500 /* Do not use atomic_add_return() as it makes UBSAN unhappy */ 501 do { 502 old = (u32)atomic_read(p_id); 503 new = old + delta + segs; 504 } while (atomic_cmpxchg(p_id, old, new) != old); 505 506 return new - segs; 507 } 508 EXPORT_SYMBOL(ip_idents_reserve); 509 510 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 511 { 512 u32 hash, id; 513 514 /* Note the following code is not safe, but this is okay. */ 515 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 516 get_random_bytes(&net->ipv4.ip_id_key, 517 sizeof(net->ipv4.ip_id_key)); 518 519 hash = siphash_3u32((__force u32)iph->daddr, 520 (__force u32)iph->saddr, 521 iph->protocol, 522 &net->ipv4.ip_id_key); 523 id = ip_idents_reserve(hash, segs); 524 iph->id = htons(id); 525 } 526 EXPORT_SYMBOL(__ip_select_ident); 527 528 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 529 const struct sock *sk, 530 const struct iphdr *iph, 531 int oif, u8 tos, 532 u8 prot, u32 mark, int flow_flags) 533 { 534 if (sk) { 535 const struct inet_sock *inet = inet_sk(sk); 536 537 oif = sk->sk_bound_dev_if; 538 mark = sk->sk_mark; 539 tos = RT_CONN_FLAGS(sk); 540 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 541 } 542 flowi4_init_output(fl4, oif, mark, tos, 543 RT_SCOPE_UNIVERSE, prot, 544 flow_flags, 545 iph->daddr, iph->saddr, 0, 0, 546 sock_net_uid(net, sk)); 547 } 548 549 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 550 const struct sock *sk) 551 { 552 const struct net *net = dev_net(skb->dev); 553 const struct iphdr *iph = ip_hdr(skb); 554 int oif = skb->dev->ifindex; 555 u8 tos = RT_TOS(iph->tos); 556 u8 prot = iph->protocol; 557 u32 mark = skb->mark; 558 559 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 560 } 561 562 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 563 { 564 const struct inet_sock *inet = inet_sk(sk); 565 const struct ip_options_rcu *inet_opt; 566 __be32 daddr = inet->inet_daddr; 567 568 rcu_read_lock(); 569 inet_opt = rcu_dereference(inet->inet_opt); 570 if (inet_opt && inet_opt->opt.srr) 571 daddr = inet_opt->opt.faddr; 572 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 573 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 574 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 575 inet_sk_flowi_flags(sk), 576 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 577 rcu_read_unlock(); 578 } 579 580 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 581 const struct sk_buff *skb) 582 { 583 if (skb) 584 build_skb_flow_key(fl4, skb, sk); 585 else 586 build_sk_flow_key(fl4, sk); 587 } 588 589 static DEFINE_SPINLOCK(fnhe_lock); 590 591 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 592 { 593 struct rtable *rt; 594 595 rt = rcu_dereference(fnhe->fnhe_rth_input); 596 if (rt) { 597 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 598 dst_dev_put(&rt->dst); 599 dst_release(&rt->dst); 600 } 601 rt = rcu_dereference(fnhe->fnhe_rth_output); 602 if (rt) { 603 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 604 dst_dev_put(&rt->dst); 605 dst_release(&rt->dst); 606 } 607 } 608 609 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 610 { 611 struct fib_nh_exception *fnhe, *oldest; 612 613 oldest = rcu_dereference(hash->chain); 614 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 615 fnhe = rcu_dereference(fnhe->fnhe_next)) { 616 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 617 oldest = fnhe; 618 } 619 fnhe_flush_routes(oldest); 620 return oldest; 621 } 622 623 static inline u32 fnhe_hashfun(__be32 daddr) 624 { 625 static u32 fnhe_hashrnd __read_mostly; 626 u32 hval; 627 628 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 629 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 630 return hash_32(hval, FNHE_HASH_SHIFT); 631 } 632 633 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 634 { 635 rt->rt_pmtu = fnhe->fnhe_pmtu; 636 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 637 rt->dst.expires = fnhe->fnhe_expires; 638 639 if (fnhe->fnhe_gw) { 640 rt->rt_flags |= RTCF_REDIRECTED; 641 rt->rt_gw_family = AF_INET; 642 rt->rt_gw4 = fnhe->fnhe_gw; 643 } 644 } 645 646 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, 647 u32 pmtu, bool lock, unsigned long expires) 648 { 649 struct fnhe_hash_bucket *hash; 650 struct fib_nh_exception *fnhe; 651 struct rtable *rt; 652 u32 genid, hval; 653 unsigned int i; 654 int depth; 655 656 genid = fnhe_genid(dev_net(nh->fib_nh_dev)); 657 hval = fnhe_hashfun(daddr); 658 659 spin_lock_bh(&fnhe_lock); 660 661 hash = rcu_dereference(nh->nh_exceptions); 662 if (!hash) { 663 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 664 if (!hash) 665 goto out_unlock; 666 rcu_assign_pointer(nh->nh_exceptions, hash); 667 } 668 669 hash += hval; 670 671 depth = 0; 672 for (fnhe = rcu_dereference(hash->chain); fnhe; 673 fnhe = rcu_dereference(fnhe->fnhe_next)) { 674 if (fnhe->fnhe_daddr == daddr) 675 break; 676 depth++; 677 } 678 679 if (fnhe) { 680 if (fnhe->fnhe_genid != genid) 681 fnhe->fnhe_genid = genid; 682 if (gw) 683 fnhe->fnhe_gw = gw; 684 if (pmtu) { 685 fnhe->fnhe_pmtu = pmtu; 686 fnhe->fnhe_mtu_locked = lock; 687 } 688 fnhe->fnhe_expires = max(1UL, expires); 689 /* Update all cached dsts too */ 690 rt = rcu_dereference(fnhe->fnhe_rth_input); 691 if (rt) 692 fill_route_from_fnhe(rt, fnhe); 693 rt = rcu_dereference(fnhe->fnhe_rth_output); 694 if (rt) 695 fill_route_from_fnhe(rt, fnhe); 696 } else { 697 if (depth > FNHE_RECLAIM_DEPTH) 698 fnhe = fnhe_oldest(hash); 699 else { 700 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 701 if (!fnhe) 702 goto out_unlock; 703 704 fnhe->fnhe_next = hash->chain; 705 rcu_assign_pointer(hash->chain, fnhe); 706 } 707 fnhe->fnhe_genid = genid; 708 fnhe->fnhe_daddr = daddr; 709 fnhe->fnhe_gw = gw; 710 fnhe->fnhe_pmtu = pmtu; 711 fnhe->fnhe_mtu_locked = lock; 712 fnhe->fnhe_expires = max(1UL, expires); 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(nh->nh_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 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i); 725 rt = rcu_dereference(*prt); 726 if (rt) 727 rt->dst.obsolete = DST_OBSOLETE_KILL; 728 } 729 } 730 731 fnhe->fnhe_stamp = jiffies; 732 733 out_unlock: 734 spin_unlock_bh(&fnhe_lock); 735 } 736 737 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 738 bool kill_route) 739 { 740 __be32 new_gw = icmp_hdr(skb)->un.gateway; 741 __be32 old_gw = ip_hdr(skb)->saddr; 742 struct net_device *dev = skb->dev; 743 struct in_device *in_dev; 744 struct fib_result res; 745 struct neighbour *n; 746 struct net *net; 747 748 switch (icmp_hdr(skb)->code & 7) { 749 case ICMP_REDIR_NET: 750 case ICMP_REDIR_NETTOS: 751 case ICMP_REDIR_HOST: 752 case ICMP_REDIR_HOSTTOS: 753 break; 754 755 default: 756 return; 757 } 758 759 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 760 return; 761 762 in_dev = __in_dev_get_rcu(dev); 763 if (!in_dev) 764 return; 765 766 net = dev_net(dev); 767 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 768 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 769 ipv4_is_zeronet(new_gw)) 770 goto reject_redirect; 771 772 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 773 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 774 goto reject_redirect; 775 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 776 goto reject_redirect; 777 } else { 778 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 779 goto reject_redirect; 780 } 781 782 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 783 if (!n) 784 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 785 if (!IS_ERR(n)) { 786 if (!(n->nud_state & NUD_VALID)) { 787 neigh_event_send(n, NULL); 788 } else { 789 if (fib_lookup(net, fl4, &res, 0) == 0) { 790 struct fib_nh_common *nhc = FIB_RES_NHC(res); 791 struct fib_nh *nh; 792 793 nh = container_of(nhc, struct fib_nh, nh_common); 794 update_or_create_fnhe(nh, fl4->daddr, new_gw, 795 0, false, 796 jiffies + ip_rt_gc_timeout); 797 } 798 if (kill_route) 799 rt->dst.obsolete = DST_OBSOLETE_KILL; 800 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 801 } 802 neigh_release(n); 803 } 804 return; 805 806 reject_redirect: 807 #ifdef CONFIG_IP_ROUTE_VERBOSE 808 if (IN_DEV_LOG_MARTIANS(in_dev)) { 809 const struct iphdr *iph = (const struct iphdr *) skb->data; 810 __be32 daddr = iph->daddr; 811 __be32 saddr = iph->saddr; 812 813 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 814 " Advised path = %pI4 -> %pI4\n", 815 &old_gw, dev->name, &new_gw, 816 &saddr, &daddr); 817 } 818 #endif 819 ; 820 } 821 822 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 823 { 824 struct rtable *rt; 825 struct flowi4 fl4; 826 const struct iphdr *iph = (const struct iphdr *) skb->data; 827 struct net *net = dev_net(skb->dev); 828 int oif = skb->dev->ifindex; 829 u8 tos = RT_TOS(iph->tos); 830 u8 prot = iph->protocol; 831 u32 mark = skb->mark; 832 833 rt = (struct rtable *) dst; 834 835 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 836 __ip_do_redirect(rt, skb, &fl4, true); 837 } 838 839 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 840 { 841 struct rtable *rt = (struct rtable *)dst; 842 struct dst_entry *ret = dst; 843 844 if (rt) { 845 if (dst->obsolete > 0) { 846 ip_rt_put(rt); 847 ret = NULL; 848 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 849 rt->dst.expires) { 850 ip_rt_put(rt); 851 ret = NULL; 852 } 853 } 854 return ret; 855 } 856 857 /* 858 * Algorithm: 859 * 1. The first ip_rt_redirect_number redirects are sent 860 * with exponential backoff, then we stop sending them at all, 861 * assuming that the host ignores our redirects. 862 * 2. If we did not see packets requiring redirects 863 * during ip_rt_redirect_silence, we assume that the host 864 * forgot redirected route and start to send redirects again. 865 * 866 * This algorithm is much cheaper and more intelligent than dumb load limiting 867 * in icmp.c. 868 * 869 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 870 * and "frag. need" (breaks PMTU discovery) in icmp.c. 871 */ 872 873 void ip_rt_send_redirect(struct sk_buff *skb) 874 { 875 struct rtable *rt = skb_rtable(skb); 876 struct in_device *in_dev; 877 struct inet_peer *peer; 878 struct net *net; 879 int log_martians; 880 int vif; 881 882 rcu_read_lock(); 883 in_dev = __in_dev_get_rcu(rt->dst.dev); 884 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 885 rcu_read_unlock(); 886 return; 887 } 888 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 889 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 890 rcu_read_unlock(); 891 892 net = dev_net(rt->dst.dev); 893 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 894 if (!peer) { 895 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 896 rt_nexthop(rt, ip_hdr(skb)->daddr)); 897 return; 898 } 899 900 /* No redirected packets during ip_rt_redirect_silence; 901 * reset the algorithm. 902 */ 903 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 904 peer->rate_tokens = 0; 905 peer->n_redirects = 0; 906 } 907 908 /* Too many ignored redirects; do not send anything 909 * set dst.rate_last to the last seen redirected packet. 910 */ 911 if (peer->n_redirects >= ip_rt_redirect_number) { 912 peer->rate_last = jiffies; 913 goto out_put_peer; 914 } 915 916 /* Check for load limit; set rate_last to the latest sent 917 * redirect. 918 */ 919 if (peer->rate_tokens == 0 || 920 time_after(jiffies, 921 (peer->rate_last + 922 (ip_rt_redirect_load << peer->rate_tokens)))) { 923 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 924 925 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 926 peer->rate_last = jiffies; 927 ++peer->rate_tokens; 928 ++peer->n_redirects; 929 #ifdef CONFIG_IP_ROUTE_VERBOSE 930 if (log_martians && 931 peer->rate_tokens == ip_rt_redirect_number) 932 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 933 &ip_hdr(skb)->saddr, inet_iif(skb), 934 &ip_hdr(skb)->daddr, &gw); 935 #endif 936 } 937 out_put_peer: 938 inet_putpeer(peer); 939 } 940 941 static int ip_error(struct sk_buff *skb) 942 { 943 struct rtable *rt = skb_rtable(skb); 944 struct net_device *dev = skb->dev; 945 struct in_device *in_dev; 946 struct inet_peer *peer; 947 unsigned long now; 948 struct net *net; 949 bool send; 950 int code; 951 952 if (netif_is_l3_master(skb->dev)) { 953 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 954 if (!dev) 955 goto out; 956 } 957 958 in_dev = __in_dev_get_rcu(dev); 959 960 /* IP on this device is disabled. */ 961 if (!in_dev) 962 goto out; 963 964 net = dev_net(rt->dst.dev); 965 if (!IN_DEV_FORWARD(in_dev)) { 966 switch (rt->dst.error) { 967 case EHOSTUNREACH: 968 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 969 break; 970 971 case ENETUNREACH: 972 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 973 break; 974 } 975 goto out; 976 } 977 978 switch (rt->dst.error) { 979 case EINVAL: 980 default: 981 goto out; 982 case EHOSTUNREACH: 983 code = ICMP_HOST_UNREACH; 984 break; 985 case ENETUNREACH: 986 code = ICMP_NET_UNREACH; 987 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 988 break; 989 case EACCES: 990 code = ICMP_PKT_FILTERED; 991 break; 992 } 993 994 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 995 l3mdev_master_ifindex(skb->dev), 1); 996 997 send = true; 998 if (peer) { 999 now = jiffies; 1000 peer->rate_tokens += now - peer->rate_last; 1001 if (peer->rate_tokens > ip_rt_error_burst) 1002 peer->rate_tokens = ip_rt_error_burst; 1003 peer->rate_last = now; 1004 if (peer->rate_tokens >= ip_rt_error_cost) 1005 peer->rate_tokens -= ip_rt_error_cost; 1006 else 1007 send = false; 1008 inet_putpeer(peer); 1009 } 1010 if (send) 1011 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1012 1013 out: kfree_skb(skb); 1014 return 0; 1015 } 1016 1017 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1018 { 1019 struct dst_entry *dst = &rt->dst; 1020 u32 old_mtu = ipv4_mtu(dst); 1021 struct fib_result res; 1022 bool lock = false; 1023 1024 if (ip_mtu_locked(dst)) 1025 return; 1026 1027 if (old_mtu < mtu) 1028 return; 1029 1030 if (mtu < ip_rt_min_pmtu) { 1031 lock = true; 1032 mtu = min(old_mtu, ip_rt_min_pmtu); 1033 } 1034 1035 if (rt->rt_pmtu == mtu && !lock && 1036 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 1037 return; 1038 1039 rcu_read_lock(); 1040 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) { 1041 struct fib_nh_common *nhc = FIB_RES_NHC(res); 1042 struct fib_nh *nh; 1043 1044 nh = container_of(nhc, struct fib_nh, nh_common); 1045 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock, 1046 jiffies + ip_rt_mtu_expires); 1047 } 1048 rcu_read_unlock(); 1049 } 1050 1051 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1052 struct sk_buff *skb, u32 mtu) 1053 { 1054 struct rtable *rt = (struct rtable *) dst; 1055 struct flowi4 fl4; 1056 1057 ip_rt_build_flow_key(&fl4, sk, skb); 1058 __ip_rt_update_pmtu(rt, &fl4, mtu); 1059 } 1060 1061 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1062 int oif, u8 protocol) 1063 { 1064 const struct iphdr *iph = (const struct iphdr *) skb->data; 1065 struct flowi4 fl4; 1066 struct rtable *rt; 1067 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1068 1069 __build_flow_key(net, &fl4, NULL, iph, oif, 1070 RT_TOS(iph->tos), protocol, mark, 0); 1071 rt = __ip_route_output_key(net, &fl4); 1072 if (!IS_ERR(rt)) { 1073 __ip_rt_update_pmtu(rt, &fl4, mtu); 1074 ip_rt_put(rt); 1075 } 1076 } 1077 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1078 1079 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1080 { 1081 const struct iphdr *iph = (const struct iphdr *) skb->data; 1082 struct flowi4 fl4; 1083 struct rtable *rt; 1084 1085 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1086 1087 if (!fl4.flowi4_mark) 1088 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1089 1090 rt = __ip_route_output_key(sock_net(sk), &fl4); 1091 if (!IS_ERR(rt)) { 1092 __ip_rt_update_pmtu(rt, &fl4, mtu); 1093 ip_rt_put(rt); 1094 } 1095 } 1096 1097 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 struct dst_entry *odst = NULL; 1103 bool new = false; 1104 struct net *net = sock_net(sk); 1105 1106 bh_lock_sock(sk); 1107 1108 if (!ip_sk_accept_pmtu(sk)) 1109 goto out; 1110 1111 odst = sk_dst_get(sk); 1112 1113 if (sock_owned_by_user(sk) || !odst) { 1114 __ipv4_sk_update_pmtu(skb, sk, mtu); 1115 goto out; 1116 } 1117 1118 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1119 1120 rt = (struct rtable *)odst; 1121 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1122 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1123 if (IS_ERR(rt)) 1124 goto out; 1125 1126 new = true; 1127 } 1128 1129 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu); 1130 1131 if (!dst_check(&rt->dst, 0)) { 1132 if (new) 1133 dst_release(&rt->dst); 1134 1135 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1136 if (IS_ERR(rt)) 1137 goto out; 1138 1139 new = true; 1140 } 1141 1142 if (new) 1143 sk_dst_set(sk, &rt->dst); 1144 1145 out: 1146 bh_unlock_sock(sk); 1147 dst_release(odst); 1148 } 1149 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1150 1151 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1152 int oif, u8 protocol) 1153 { 1154 const struct iphdr *iph = (const struct iphdr *) skb->data; 1155 struct flowi4 fl4; 1156 struct rtable *rt; 1157 1158 __build_flow_key(net, &fl4, NULL, iph, oif, 1159 RT_TOS(iph->tos), protocol, 0, 0); 1160 rt = __ip_route_output_key(net, &fl4); 1161 if (!IS_ERR(rt)) { 1162 __ip_do_redirect(rt, skb, &fl4, false); 1163 ip_rt_put(rt); 1164 } 1165 } 1166 EXPORT_SYMBOL_GPL(ipv4_redirect); 1167 1168 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1169 { 1170 const struct iphdr *iph = (const struct iphdr *) skb->data; 1171 struct flowi4 fl4; 1172 struct rtable *rt; 1173 struct net *net = sock_net(sk); 1174 1175 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1176 rt = __ip_route_output_key(net, &fl4); 1177 if (!IS_ERR(rt)) { 1178 __ip_do_redirect(rt, skb, &fl4, false); 1179 ip_rt_put(rt); 1180 } 1181 } 1182 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1183 1184 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1185 { 1186 struct rtable *rt = (struct rtable *) dst; 1187 1188 /* All IPV4 dsts are created with ->obsolete set to the value 1189 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1190 * into this function always. 1191 * 1192 * When a PMTU/redirect information update invalidates a route, 1193 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1194 * DST_OBSOLETE_DEAD. 1195 */ 1196 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1197 return NULL; 1198 return dst; 1199 } 1200 1201 static void ipv4_link_failure(struct sk_buff *skb) 1202 { 1203 struct rtable *rt; 1204 1205 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1206 1207 rt = skb_rtable(skb); 1208 if (rt) 1209 dst_set_expires(&rt->dst, 0); 1210 } 1211 1212 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1213 { 1214 pr_debug("%s: %pI4 -> %pI4, %s\n", 1215 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1216 skb->dev ? skb->dev->name : "?"); 1217 kfree_skb(skb); 1218 WARN_ON(1); 1219 return 0; 1220 } 1221 1222 /* 1223 We do not cache source address of outgoing interface, 1224 because it is used only by IP RR, TS and SRR options, 1225 so that it out of fast path. 1226 1227 BTW remember: "addr" is allowed to be not aligned 1228 in IP options! 1229 */ 1230 1231 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1232 { 1233 __be32 src; 1234 1235 if (rt_is_output_route(rt)) 1236 src = ip_hdr(skb)->saddr; 1237 else { 1238 struct fib_result res; 1239 struct iphdr *iph = ip_hdr(skb); 1240 struct flowi4 fl4 = { 1241 .daddr = iph->daddr, 1242 .saddr = iph->saddr, 1243 .flowi4_tos = RT_TOS(iph->tos), 1244 .flowi4_oif = rt->dst.dev->ifindex, 1245 .flowi4_iif = skb->dev->ifindex, 1246 .flowi4_mark = skb->mark, 1247 }; 1248 1249 rcu_read_lock(); 1250 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1251 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1252 else 1253 src = inet_select_addr(rt->dst.dev, 1254 rt_nexthop(rt, iph->daddr), 1255 RT_SCOPE_UNIVERSE); 1256 rcu_read_unlock(); 1257 } 1258 memcpy(addr, &src, 4); 1259 } 1260 1261 #ifdef CONFIG_IP_ROUTE_CLASSID 1262 static void set_class_tag(struct rtable *rt, u32 tag) 1263 { 1264 if (!(rt->dst.tclassid & 0xFFFF)) 1265 rt->dst.tclassid |= tag & 0xFFFF; 1266 if (!(rt->dst.tclassid & 0xFFFF0000)) 1267 rt->dst.tclassid |= tag & 0xFFFF0000; 1268 } 1269 #endif 1270 1271 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1272 { 1273 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1274 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1275 ip_rt_min_advmss); 1276 1277 return min(advmss, IPV4_MAX_PMTU - header_size); 1278 } 1279 1280 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1281 { 1282 const struct rtable *rt = (const struct rtable *) dst; 1283 unsigned int mtu = rt->rt_pmtu; 1284 1285 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1286 mtu = dst_metric_raw(dst, RTAX_MTU); 1287 1288 if (mtu) 1289 return mtu; 1290 1291 mtu = READ_ONCE(dst->dev->mtu); 1292 1293 if (unlikely(ip_mtu_locked(dst))) { 1294 if (rt->rt_gw_family && mtu > 576) 1295 mtu = 576; 1296 } 1297 1298 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1299 1300 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1301 } 1302 1303 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr) 1304 { 1305 struct fnhe_hash_bucket *hash; 1306 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1307 u32 hval = fnhe_hashfun(daddr); 1308 1309 spin_lock_bh(&fnhe_lock); 1310 1311 hash = rcu_dereference_protected(nh->nh_exceptions, 1312 lockdep_is_held(&fnhe_lock)); 1313 hash += hval; 1314 1315 fnhe_p = &hash->chain; 1316 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1317 while (fnhe) { 1318 if (fnhe->fnhe_daddr == daddr) { 1319 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1320 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1321 /* set fnhe_daddr to 0 to ensure it won't bind with 1322 * new dsts in rt_bind_exception(). 1323 */ 1324 fnhe->fnhe_daddr = 0; 1325 fnhe_flush_routes(fnhe); 1326 kfree_rcu(fnhe, rcu); 1327 break; 1328 } 1329 fnhe_p = &fnhe->fnhe_next; 1330 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1331 lockdep_is_held(&fnhe_lock)); 1332 } 1333 1334 spin_unlock_bh(&fnhe_lock); 1335 } 1336 1337 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) 1338 { 1339 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions); 1340 struct fib_nh_exception *fnhe; 1341 u32 hval; 1342 1343 if (!hash) 1344 return NULL; 1345 1346 hval = fnhe_hashfun(daddr); 1347 1348 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1349 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1350 if (fnhe->fnhe_daddr == daddr) { 1351 if (fnhe->fnhe_expires && 1352 time_after(jiffies, fnhe->fnhe_expires)) { 1353 ip_del_fnhe(nh, daddr); 1354 break; 1355 } 1356 return fnhe; 1357 } 1358 } 1359 return NULL; 1360 } 1361 1362 /* MTU selection: 1363 * 1. mtu on route is locked - use it 1364 * 2. mtu from nexthop exception 1365 * 3. mtu from egress device 1366 */ 1367 1368 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1369 { 1370 struct fib_nh_common *nhc = res->nhc; 1371 struct net_device *dev = nhc->nhc_dev; 1372 struct fib_info *fi = res->fi; 1373 u32 mtu = 0; 1374 1375 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1376 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1377 mtu = fi->fib_mtu; 1378 1379 if (likely(!mtu)) { 1380 struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common); 1381 struct fib_nh_exception *fnhe; 1382 1383 fnhe = find_exception(nh, daddr); 1384 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1385 mtu = fnhe->fnhe_pmtu; 1386 } 1387 1388 if (likely(!mtu)) 1389 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1390 1391 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1392 } 1393 1394 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1395 __be32 daddr, const bool do_cache) 1396 { 1397 bool ret = false; 1398 1399 spin_lock_bh(&fnhe_lock); 1400 1401 if (daddr == fnhe->fnhe_daddr) { 1402 struct rtable __rcu **porig; 1403 struct rtable *orig; 1404 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1405 1406 if (rt_is_input_route(rt)) 1407 porig = &fnhe->fnhe_rth_input; 1408 else 1409 porig = &fnhe->fnhe_rth_output; 1410 orig = rcu_dereference(*porig); 1411 1412 if (fnhe->fnhe_genid != genid) { 1413 fnhe->fnhe_genid = genid; 1414 fnhe->fnhe_gw = 0; 1415 fnhe->fnhe_pmtu = 0; 1416 fnhe->fnhe_expires = 0; 1417 fnhe->fnhe_mtu_locked = false; 1418 fnhe_flush_routes(fnhe); 1419 orig = NULL; 1420 } 1421 fill_route_from_fnhe(rt, fnhe); 1422 if (!rt->rt_gw4) { 1423 rt->rt_gw4 = daddr; 1424 rt->rt_gw_family = AF_INET; 1425 } 1426 1427 if (do_cache) { 1428 dst_hold(&rt->dst); 1429 rcu_assign_pointer(*porig, rt); 1430 if (orig) { 1431 dst_dev_put(&orig->dst); 1432 dst_release(&orig->dst); 1433 } 1434 ret = true; 1435 } 1436 1437 fnhe->fnhe_stamp = jiffies; 1438 } 1439 spin_unlock_bh(&fnhe_lock); 1440 1441 return ret; 1442 } 1443 1444 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) 1445 { 1446 struct rtable *orig, *prev, **p; 1447 bool ret = true; 1448 1449 if (rt_is_input_route(rt)) { 1450 p = (struct rtable **)&nh->nh_rth_input; 1451 } else { 1452 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output); 1453 } 1454 orig = *p; 1455 1456 /* hold dst before doing cmpxchg() to avoid race condition 1457 * on this dst 1458 */ 1459 dst_hold(&rt->dst); 1460 prev = cmpxchg(p, orig, rt); 1461 if (prev == orig) { 1462 if (orig) { 1463 dst_dev_put(&orig->dst); 1464 dst_release(&orig->dst); 1465 } 1466 } else { 1467 dst_release(&rt->dst); 1468 ret = false; 1469 } 1470 1471 return ret; 1472 } 1473 1474 struct uncached_list { 1475 spinlock_t lock; 1476 struct list_head head; 1477 }; 1478 1479 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1480 1481 void rt_add_uncached_list(struct rtable *rt) 1482 { 1483 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1484 1485 rt->rt_uncached_list = ul; 1486 1487 spin_lock_bh(&ul->lock); 1488 list_add_tail(&rt->rt_uncached, &ul->head); 1489 spin_unlock_bh(&ul->lock); 1490 } 1491 1492 void rt_del_uncached_list(struct rtable *rt) 1493 { 1494 if (!list_empty(&rt->rt_uncached)) { 1495 struct uncached_list *ul = rt->rt_uncached_list; 1496 1497 spin_lock_bh(&ul->lock); 1498 list_del(&rt->rt_uncached); 1499 spin_unlock_bh(&ul->lock); 1500 } 1501 } 1502 1503 static void ipv4_dst_destroy(struct dst_entry *dst) 1504 { 1505 struct rtable *rt = (struct rtable *)dst; 1506 1507 ip_dst_metrics_put(dst); 1508 rt_del_uncached_list(rt); 1509 } 1510 1511 void rt_flush_dev(struct net_device *dev) 1512 { 1513 struct net *net = dev_net(dev); 1514 struct rtable *rt; 1515 int cpu; 1516 1517 for_each_possible_cpu(cpu) { 1518 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1519 1520 spin_lock_bh(&ul->lock); 1521 list_for_each_entry(rt, &ul->head, rt_uncached) { 1522 if (rt->dst.dev != dev) 1523 continue; 1524 rt->dst.dev = net->loopback_dev; 1525 dev_hold(rt->dst.dev); 1526 dev_put(dev); 1527 } 1528 spin_unlock_bh(&ul->lock); 1529 } 1530 } 1531 1532 static bool rt_cache_valid(const struct rtable *rt) 1533 { 1534 return rt && 1535 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1536 !rt_is_expired(rt); 1537 } 1538 1539 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1540 const struct fib_result *res, 1541 struct fib_nh_exception *fnhe, 1542 struct fib_info *fi, u16 type, u32 itag, 1543 const bool do_cache) 1544 { 1545 bool cached = false; 1546 1547 if (fi) { 1548 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1549 struct fib_nh *nh; 1550 1551 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1552 rt->rt_gw_family = nhc->nhc_gw_family; 1553 /* only INET and INET6 are supported */ 1554 if (likely(nhc->nhc_gw_family == AF_INET)) 1555 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1556 else 1557 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1558 } 1559 1560 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1561 1562 nh = container_of(nhc, struct fib_nh, nh_common); 1563 #ifdef CONFIG_IP_ROUTE_CLASSID 1564 rt->dst.tclassid = nh->nh_tclassid; 1565 #endif 1566 rt->dst.lwtstate = lwtstate_get(nh->fib_nh_lws); 1567 if (unlikely(fnhe)) 1568 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1569 else if (do_cache) 1570 cached = rt_cache_route(nh, rt); 1571 if (unlikely(!cached)) { 1572 /* Routes we intend to cache in nexthop exception or 1573 * FIB nexthop have the DST_NOCACHE bit clear. 1574 * However, if we are unsuccessful at storing this 1575 * route into the cache we really need to set it. 1576 */ 1577 if (!rt->rt_gw4) { 1578 rt->rt_gw_family = AF_INET; 1579 rt->rt_gw4 = daddr; 1580 } 1581 rt_add_uncached_list(rt); 1582 } 1583 } else 1584 rt_add_uncached_list(rt); 1585 1586 #ifdef CONFIG_IP_ROUTE_CLASSID 1587 #ifdef CONFIG_IP_MULTIPLE_TABLES 1588 set_class_tag(rt, res->tclassid); 1589 #endif 1590 set_class_tag(rt, itag); 1591 #endif 1592 } 1593 1594 struct rtable *rt_dst_alloc(struct net_device *dev, 1595 unsigned int flags, u16 type, 1596 bool nopolicy, bool noxfrm, bool will_cache) 1597 { 1598 struct rtable *rt; 1599 1600 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1601 (will_cache ? 0 : DST_HOST) | 1602 (nopolicy ? DST_NOPOLICY : 0) | 1603 (noxfrm ? DST_NOXFRM : 0)); 1604 1605 if (rt) { 1606 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1607 rt->rt_flags = flags; 1608 rt->rt_type = type; 1609 rt->rt_is_input = 0; 1610 rt->rt_iif = 0; 1611 rt->rt_pmtu = 0; 1612 rt->rt_mtu_locked = 0; 1613 rt->rt_gw_family = 0; 1614 rt->rt_gw4 = 0; 1615 INIT_LIST_HEAD(&rt->rt_uncached); 1616 1617 rt->dst.output = ip_output; 1618 if (flags & RTCF_LOCAL) 1619 rt->dst.input = ip_local_deliver; 1620 } 1621 1622 return rt; 1623 } 1624 EXPORT_SYMBOL(rt_dst_alloc); 1625 1626 /* called in rcu_read_lock() section */ 1627 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1628 u8 tos, struct net_device *dev, 1629 struct in_device *in_dev, u32 *itag) 1630 { 1631 int err; 1632 1633 /* Primary sanity checks. */ 1634 if (!in_dev) 1635 return -EINVAL; 1636 1637 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1638 skb->protocol != htons(ETH_P_IP)) 1639 return -EINVAL; 1640 1641 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1642 return -EINVAL; 1643 1644 if (ipv4_is_zeronet(saddr)) { 1645 if (!ipv4_is_local_multicast(daddr) && 1646 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1647 return -EINVAL; 1648 } else { 1649 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1650 in_dev, itag); 1651 if (err < 0) 1652 return err; 1653 } 1654 return 0; 1655 } 1656 1657 /* called in rcu_read_lock() section */ 1658 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1659 u8 tos, struct net_device *dev, int our) 1660 { 1661 struct in_device *in_dev = __in_dev_get_rcu(dev); 1662 unsigned int flags = RTCF_MULTICAST; 1663 struct rtable *rth; 1664 u32 itag = 0; 1665 int err; 1666 1667 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1668 if (err) 1669 return err; 1670 1671 if (our) 1672 flags |= RTCF_LOCAL; 1673 1674 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1675 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1676 if (!rth) 1677 return -ENOBUFS; 1678 1679 #ifdef CONFIG_IP_ROUTE_CLASSID 1680 rth->dst.tclassid = itag; 1681 #endif 1682 rth->dst.output = ip_rt_bug; 1683 rth->rt_is_input= 1; 1684 1685 #ifdef CONFIG_IP_MROUTE 1686 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1687 rth->dst.input = ip_mr_input; 1688 #endif 1689 RT_CACHE_STAT_INC(in_slow_mc); 1690 1691 skb_dst_set(skb, &rth->dst); 1692 return 0; 1693 } 1694 1695 1696 static void ip_handle_martian_source(struct net_device *dev, 1697 struct in_device *in_dev, 1698 struct sk_buff *skb, 1699 __be32 daddr, 1700 __be32 saddr) 1701 { 1702 RT_CACHE_STAT_INC(in_martian_src); 1703 #ifdef CONFIG_IP_ROUTE_VERBOSE 1704 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1705 /* 1706 * RFC1812 recommendation, if source is martian, 1707 * the only hint is MAC header. 1708 */ 1709 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1710 &daddr, &saddr, dev->name); 1711 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1712 print_hex_dump(KERN_WARNING, "ll header: ", 1713 DUMP_PREFIX_OFFSET, 16, 1, 1714 skb_mac_header(skb), 1715 dev->hard_header_len, false); 1716 } 1717 } 1718 #endif 1719 } 1720 1721 /* called in rcu_read_lock() section */ 1722 static int __mkroute_input(struct sk_buff *skb, 1723 const struct fib_result *res, 1724 struct in_device *in_dev, 1725 __be32 daddr, __be32 saddr, u32 tos) 1726 { 1727 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1728 struct net_device *dev = nhc->nhc_dev; 1729 struct fib_nh_exception *fnhe; 1730 struct rtable *rth; 1731 struct fib_nh *nh; 1732 int err; 1733 struct in_device *out_dev; 1734 bool do_cache; 1735 u32 itag = 0; 1736 1737 /* get a working reference to the output device */ 1738 out_dev = __in_dev_get_rcu(dev); 1739 if (!out_dev) { 1740 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1741 return -EINVAL; 1742 } 1743 1744 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1745 in_dev->dev, in_dev, &itag); 1746 if (err < 0) { 1747 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1748 saddr); 1749 1750 goto cleanup; 1751 } 1752 1753 do_cache = res->fi && !itag; 1754 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1755 skb->protocol == htons(ETH_P_IP)) { 1756 __be32 gw; 1757 1758 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1759 if (IN_DEV_SHARED_MEDIA(out_dev) || 1760 inet_addr_onlink(out_dev, saddr, gw)) 1761 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1762 } 1763 1764 if (skb->protocol != htons(ETH_P_IP)) { 1765 /* Not IP (i.e. ARP). Do not create route, if it is 1766 * invalid for proxy arp. DNAT routes are always valid. 1767 * 1768 * Proxy arp feature have been extended to allow, ARP 1769 * replies back to the same interface, to support 1770 * Private VLAN switch technologies. See arp.c. 1771 */ 1772 if (out_dev == in_dev && 1773 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1774 err = -EINVAL; 1775 goto cleanup; 1776 } 1777 } 1778 1779 nh = container_of(nhc, struct fib_nh, nh_common); 1780 fnhe = find_exception(nh, daddr); 1781 if (do_cache) { 1782 if (fnhe) 1783 rth = rcu_dereference(fnhe->fnhe_rth_input); 1784 else 1785 rth = rcu_dereference(nh->nh_rth_input); 1786 if (rt_cache_valid(rth)) { 1787 skb_dst_set_noref(skb, &rth->dst); 1788 goto out; 1789 } 1790 } 1791 1792 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1793 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1794 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1795 if (!rth) { 1796 err = -ENOBUFS; 1797 goto cleanup; 1798 } 1799 1800 rth->rt_is_input = 1; 1801 RT_CACHE_STAT_INC(in_slow_tot); 1802 1803 rth->dst.input = ip_forward; 1804 1805 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1806 do_cache); 1807 lwtunnel_set_redirect(&rth->dst); 1808 skb_dst_set(skb, &rth->dst); 1809 out: 1810 err = 0; 1811 cleanup: 1812 return err; 1813 } 1814 1815 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1816 /* To make ICMP packets follow the right flow, the multipath hash is 1817 * calculated from the inner IP addresses. 1818 */ 1819 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1820 struct flow_keys *hash_keys) 1821 { 1822 const struct iphdr *outer_iph = ip_hdr(skb); 1823 const struct iphdr *key_iph = outer_iph; 1824 const struct iphdr *inner_iph; 1825 const struct icmphdr *icmph; 1826 struct iphdr _inner_iph; 1827 struct icmphdr _icmph; 1828 1829 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1830 goto out; 1831 1832 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1833 goto out; 1834 1835 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1836 &_icmph); 1837 if (!icmph) 1838 goto out; 1839 1840 if (icmph->type != ICMP_DEST_UNREACH && 1841 icmph->type != ICMP_REDIRECT && 1842 icmph->type != ICMP_TIME_EXCEEDED && 1843 icmph->type != ICMP_PARAMETERPROB) 1844 goto out; 1845 1846 inner_iph = skb_header_pointer(skb, 1847 outer_iph->ihl * 4 + sizeof(_icmph), 1848 sizeof(_inner_iph), &_inner_iph); 1849 if (!inner_iph) 1850 goto out; 1851 1852 key_iph = inner_iph; 1853 out: 1854 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1855 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1856 } 1857 1858 /* if skb is set it will be used and fl4 can be NULL */ 1859 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 1860 const struct sk_buff *skb, struct flow_keys *flkeys) 1861 { 1862 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 1863 struct flow_keys hash_keys; 1864 u32 mhash; 1865 1866 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 1867 case 0: 1868 memset(&hash_keys, 0, sizeof(hash_keys)); 1869 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1870 if (skb) { 1871 ip_multipath_l3_keys(skb, &hash_keys); 1872 } else { 1873 hash_keys.addrs.v4addrs.src = fl4->saddr; 1874 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1875 } 1876 break; 1877 case 1: 1878 /* skb is currently provided only when forwarding */ 1879 if (skb) { 1880 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 1881 struct flow_keys keys; 1882 1883 /* short-circuit if we already have L4 hash present */ 1884 if (skb->l4_hash) 1885 return skb_get_hash_raw(skb) >> 1; 1886 1887 memset(&hash_keys, 0, sizeof(hash_keys)); 1888 1889 if (!flkeys) { 1890 skb_flow_dissect_flow_keys(skb, &keys, flag); 1891 flkeys = &keys; 1892 } 1893 1894 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1895 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 1896 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 1897 hash_keys.ports.src = flkeys->ports.src; 1898 hash_keys.ports.dst = flkeys->ports.dst; 1899 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 1900 } else { 1901 memset(&hash_keys, 0, sizeof(hash_keys)); 1902 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1903 hash_keys.addrs.v4addrs.src = fl4->saddr; 1904 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1905 hash_keys.ports.src = fl4->fl4_sport; 1906 hash_keys.ports.dst = fl4->fl4_dport; 1907 hash_keys.basic.ip_proto = fl4->flowi4_proto; 1908 } 1909 break; 1910 } 1911 mhash = flow_hash_from_keys(&hash_keys); 1912 1913 if (multipath_hash) 1914 mhash = jhash_2words(mhash, multipath_hash, 0); 1915 1916 return mhash >> 1; 1917 } 1918 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1919 1920 static int ip_mkroute_input(struct sk_buff *skb, 1921 struct fib_result *res, 1922 struct in_device *in_dev, 1923 __be32 daddr, __be32 saddr, u32 tos, 1924 struct flow_keys *hkeys) 1925 { 1926 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1927 if (res->fi && res->fi->fib_nhs > 1) { 1928 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1929 1930 fib_select_multipath(res, h); 1931 } 1932 #endif 1933 1934 /* create a routing cache entry */ 1935 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1936 } 1937 1938 /* 1939 * NOTE. We drop all the packets that has local source 1940 * addresses, because every properly looped back packet 1941 * must have correct destination already attached by output routine. 1942 * 1943 * Such approach solves two big problems: 1944 * 1. Not simplex devices are handled properly. 1945 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1946 * called with rcu_read_lock() 1947 */ 1948 1949 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1950 u8 tos, struct net_device *dev, 1951 struct fib_result *res) 1952 { 1953 struct in_device *in_dev = __in_dev_get_rcu(dev); 1954 struct flow_keys *flkeys = NULL, _flkeys; 1955 struct net *net = dev_net(dev); 1956 struct ip_tunnel_info *tun_info; 1957 int err = -EINVAL; 1958 unsigned int flags = 0; 1959 u32 itag = 0; 1960 struct rtable *rth; 1961 struct flowi4 fl4; 1962 bool do_cache; 1963 1964 /* IP on this device is disabled. */ 1965 1966 if (!in_dev) 1967 goto out; 1968 1969 /* Check for the most weird martians, which can be not detected 1970 by fib_lookup. 1971 */ 1972 1973 tun_info = skb_tunnel_info(skb); 1974 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1975 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1976 else 1977 fl4.flowi4_tun_key.tun_id = 0; 1978 skb_dst_drop(skb); 1979 1980 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 1981 goto martian_source; 1982 1983 res->fi = NULL; 1984 res->table = NULL; 1985 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 1986 goto brd_input; 1987 1988 /* Accept zero addresses only to limited broadcast; 1989 * I even do not know to fix it or not. Waiting for complains :-) 1990 */ 1991 if (ipv4_is_zeronet(saddr)) 1992 goto martian_source; 1993 1994 if (ipv4_is_zeronet(daddr)) 1995 goto martian_destination; 1996 1997 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 1998 * and call it once if daddr or/and saddr are loopback addresses 1999 */ 2000 if (ipv4_is_loopback(daddr)) { 2001 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2002 goto martian_destination; 2003 } else if (ipv4_is_loopback(saddr)) { 2004 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2005 goto martian_source; 2006 } 2007 2008 /* 2009 * Now we are ready to route packet. 2010 */ 2011 fl4.flowi4_oif = 0; 2012 fl4.flowi4_iif = dev->ifindex; 2013 fl4.flowi4_mark = skb->mark; 2014 fl4.flowi4_tos = tos; 2015 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2016 fl4.flowi4_flags = 0; 2017 fl4.daddr = daddr; 2018 fl4.saddr = saddr; 2019 fl4.flowi4_uid = sock_net_uid(net, NULL); 2020 2021 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2022 flkeys = &_flkeys; 2023 } else { 2024 fl4.flowi4_proto = 0; 2025 fl4.fl4_sport = 0; 2026 fl4.fl4_dport = 0; 2027 } 2028 2029 err = fib_lookup(net, &fl4, res, 0); 2030 if (err != 0) { 2031 if (!IN_DEV_FORWARD(in_dev)) 2032 err = -EHOSTUNREACH; 2033 goto no_route; 2034 } 2035 2036 if (res->type == RTN_BROADCAST) { 2037 if (IN_DEV_BFORWARD(in_dev)) 2038 goto make_route; 2039 goto brd_input; 2040 } 2041 2042 if (res->type == RTN_LOCAL) { 2043 err = fib_validate_source(skb, saddr, daddr, tos, 2044 0, dev, in_dev, &itag); 2045 if (err < 0) 2046 goto martian_source; 2047 goto local_input; 2048 } 2049 2050 if (!IN_DEV_FORWARD(in_dev)) { 2051 err = -EHOSTUNREACH; 2052 goto no_route; 2053 } 2054 if (res->type != RTN_UNICAST) 2055 goto martian_destination; 2056 2057 make_route: 2058 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2059 out: return err; 2060 2061 brd_input: 2062 if (skb->protocol != htons(ETH_P_IP)) 2063 goto e_inval; 2064 2065 if (!ipv4_is_zeronet(saddr)) { 2066 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2067 in_dev, &itag); 2068 if (err < 0) 2069 goto martian_source; 2070 } 2071 flags |= RTCF_BROADCAST; 2072 res->type = RTN_BROADCAST; 2073 RT_CACHE_STAT_INC(in_brd); 2074 2075 local_input: 2076 do_cache = false; 2077 if (res->fi) { 2078 if (!itag) { 2079 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2080 struct fib_nh *nh; 2081 2082 nh = container_of(nhc, struct fib_nh, nh_common); 2083 rth = rcu_dereference(nh->nh_rth_input); 2084 if (rt_cache_valid(rth)) { 2085 skb_dst_set_noref(skb, &rth->dst); 2086 err = 0; 2087 goto out; 2088 } 2089 do_cache = true; 2090 } 2091 } 2092 2093 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2094 flags | RTCF_LOCAL, res->type, 2095 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2096 if (!rth) 2097 goto e_nobufs; 2098 2099 rth->dst.output= ip_rt_bug; 2100 #ifdef CONFIG_IP_ROUTE_CLASSID 2101 rth->dst.tclassid = itag; 2102 #endif 2103 rth->rt_is_input = 1; 2104 2105 RT_CACHE_STAT_INC(in_slow_tot); 2106 if (res->type == RTN_UNREACHABLE) { 2107 rth->dst.input= ip_error; 2108 rth->dst.error= -err; 2109 rth->rt_flags &= ~RTCF_LOCAL; 2110 } 2111 2112 if (do_cache) { 2113 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2114 struct fib_nh *nh; 2115 2116 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2117 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2118 WARN_ON(rth->dst.input == lwtunnel_input); 2119 rth->dst.lwtstate->orig_input = rth->dst.input; 2120 rth->dst.input = lwtunnel_input; 2121 } 2122 2123 nh = container_of(nhc, struct fib_nh, nh_common); 2124 if (unlikely(!rt_cache_route(nh, rth))) 2125 rt_add_uncached_list(rth); 2126 } 2127 skb_dst_set(skb, &rth->dst); 2128 err = 0; 2129 goto out; 2130 2131 no_route: 2132 RT_CACHE_STAT_INC(in_no_route); 2133 res->type = RTN_UNREACHABLE; 2134 res->fi = NULL; 2135 res->table = NULL; 2136 goto local_input; 2137 2138 /* 2139 * Do not cache martian addresses: they should be logged (RFC1812) 2140 */ 2141 martian_destination: 2142 RT_CACHE_STAT_INC(in_martian_dst); 2143 #ifdef CONFIG_IP_ROUTE_VERBOSE 2144 if (IN_DEV_LOG_MARTIANS(in_dev)) 2145 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2146 &daddr, &saddr, dev->name); 2147 #endif 2148 2149 e_inval: 2150 err = -EINVAL; 2151 goto out; 2152 2153 e_nobufs: 2154 err = -ENOBUFS; 2155 goto out; 2156 2157 martian_source: 2158 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2159 goto out; 2160 } 2161 2162 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2163 u8 tos, struct net_device *dev) 2164 { 2165 struct fib_result res; 2166 int err; 2167 2168 tos &= IPTOS_RT_MASK; 2169 rcu_read_lock(); 2170 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2171 rcu_read_unlock(); 2172 2173 return err; 2174 } 2175 EXPORT_SYMBOL(ip_route_input_noref); 2176 2177 /* called with rcu_read_lock held */ 2178 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2179 u8 tos, struct net_device *dev, struct fib_result *res) 2180 { 2181 /* Multicast recognition logic is moved from route cache to here. 2182 The problem was that too many Ethernet cards have broken/missing 2183 hardware multicast filters :-( As result the host on multicasting 2184 network acquires a lot of useless route cache entries, sort of 2185 SDR messages from all the world. Now we try to get rid of them. 2186 Really, provided software IP multicast filter is organized 2187 reasonably (at least, hashed), it does not result in a slowdown 2188 comparing with route cache reject entries. 2189 Note, that multicast routers are not affected, because 2190 route cache entry is created eventually. 2191 */ 2192 if (ipv4_is_multicast(daddr)) { 2193 struct in_device *in_dev = __in_dev_get_rcu(dev); 2194 int our = 0; 2195 int err = -EINVAL; 2196 2197 if (!in_dev) 2198 return err; 2199 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2200 ip_hdr(skb)->protocol); 2201 2202 /* check l3 master if no match yet */ 2203 if (!our && netif_is_l3_slave(dev)) { 2204 struct in_device *l3_in_dev; 2205 2206 l3_in_dev = __in_dev_get_rcu(skb->dev); 2207 if (l3_in_dev) 2208 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2209 ip_hdr(skb)->protocol); 2210 } 2211 2212 if (our 2213 #ifdef CONFIG_IP_MROUTE 2214 || 2215 (!ipv4_is_local_multicast(daddr) && 2216 IN_DEV_MFORWARD(in_dev)) 2217 #endif 2218 ) { 2219 err = ip_route_input_mc(skb, daddr, saddr, 2220 tos, dev, our); 2221 } 2222 return err; 2223 } 2224 2225 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2226 } 2227 2228 /* called with rcu_read_lock() */ 2229 static struct rtable *__mkroute_output(const struct fib_result *res, 2230 const struct flowi4 *fl4, int orig_oif, 2231 struct net_device *dev_out, 2232 unsigned int flags) 2233 { 2234 struct fib_info *fi = res->fi; 2235 struct fib_nh_exception *fnhe; 2236 struct in_device *in_dev; 2237 u16 type = res->type; 2238 struct rtable *rth; 2239 bool do_cache; 2240 2241 in_dev = __in_dev_get_rcu(dev_out); 2242 if (!in_dev) 2243 return ERR_PTR(-EINVAL); 2244 2245 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2246 if (ipv4_is_loopback(fl4->saddr) && 2247 !(dev_out->flags & IFF_LOOPBACK) && 2248 !netif_is_l3_master(dev_out)) 2249 return ERR_PTR(-EINVAL); 2250 2251 if (ipv4_is_lbcast(fl4->daddr)) 2252 type = RTN_BROADCAST; 2253 else if (ipv4_is_multicast(fl4->daddr)) 2254 type = RTN_MULTICAST; 2255 else if (ipv4_is_zeronet(fl4->daddr)) 2256 return ERR_PTR(-EINVAL); 2257 2258 if (dev_out->flags & IFF_LOOPBACK) 2259 flags |= RTCF_LOCAL; 2260 2261 do_cache = true; 2262 if (type == RTN_BROADCAST) { 2263 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2264 fi = NULL; 2265 } else if (type == RTN_MULTICAST) { 2266 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2267 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2268 fl4->flowi4_proto)) 2269 flags &= ~RTCF_LOCAL; 2270 else 2271 do_cache = false; 2272 /* If multicast route do not exist use 2273 * default one, but do not gateway in this case. 2274 * Yes, it is hack. 2275 */ 2276 if (fi && res->prefixlen < 4) 2277 fi = NULL; 2278 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2279 (orig_oif != dev_out->ifindex)) { 2280 /* For local routes that require a particular output interface 2281 * we do not want to cache the result. Caching the result 2282 * causes incorrect behaviour when there are multiple source 2283 * addresses on the interface, the end result being that if the 2284 * intended recipient is waiting on that interface for the 2285 * packet he won't receive it because it will be delivered on 2286 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2287 * be set to the loopback interface as well. 2288 */ 2289 do_cache = false; 2290 } 2291 2292 fnhe = NULL; 2293 do_cache &= fi != NULL; 2294 if (fi) { 2295 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2296 struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common); 2297 struct rtable __rcu **prth; 2298 2299 fnhe = find_exception(nh, fl4->daddr); 2300 if (!do_cache) 2301 goto add; 2302 if (fnhe) { 2303 prth = &fnhe->fnhe_rth_output; 2304 } else { 2305 if (unlikely(fl4->flowi4_flags & 2306 FLOWI_FLAG_KNOWN_NH && 2307 !(nhc->nhc_gw_family && 2308 nhc->nhc_scope == RT_SCOPE_LINK))) { 2309 do_cache = false; 2310 goto add; 2311 } 2312 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output); 2313 } 2314 rth = rcu_dereference(*prth); 2315 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2316 return rth; 2317 } 2318 2319 add: 2320 rth = rt_dst_alloc(dev_out, flags, type, 2321 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2322 IN_DEV_CONF_GET(in_dev, NOXFRM), 2323 do_cache); 2324 if (!rth) 2325 return ERR_PTR(-ENOBUFS); 2326 2327 rth->rt_iif = orig_oif; 2328 2329 RT_CACHE_STAT_INC(out_slow_tot); 2330 2331 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2332 if (flags & RTCF_LOCAL && 2333 !(dev_out->flags & IFF_LOOPBACK)) { 2334 rth->dst.output = ip_mc_output; 2335 RT_CACHE_STAT_INC(out_slow_mc); 2336 } 2337 #ifdef CONFIG_IP_MROUTE 2338 if (type == RTN_MULTICAST) { 2339 if (IN_DEV_MFORWARD(in_dev) && 2340 !ipv4_is_local_multicast(fl4->daddr)) { 2341 rth->dst.input = ip_mr_input; 2342 rth->dst.output = ip_mc_output; 2343 } 2344 } 2345 #endif 2346 } 2347 2348 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2349 lwtunnel_set_redirect(&rth->dst); 2350 2351 return rth; 2352 } 2353 2354 /* 2355 * Major route resolver routine. 2356 */ 2357 2358 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2359 const struct sk_buff *skb) 2360 { 2361 __u8 tos = RT_FL_TOS(fl4); 2362 struct fib_result res = { 2363 .type = RTN_UNSPEC, 2364 .fi = NULL, 2365 .table = NULL, 2366 .tclassid = 0, 2367 }; 2368 struct rtable *rth; 2369 2370 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2371 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2372 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2373 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2374 2375 rcu_read_lock(); 2376 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2377 rcu_read_unlock(); 2378 2379 return rth; 2380 } 2381 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2382 2383 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2384 struct fib_result *res, 2385 const struct sk_buff *skb) 2386 { 2387 struct net_device *dev_out = NULL; 2388 int orig_oif = fl4->flowi4_oif; 2389 unsigned int flags = 0; 2390 struct rtable *rth; 2391 int err = -ENETUNREACH; 2392 2393 if (fl4->saddr) { 2394 rth = ERR_PTR(-EINVAL); 2395 if (ipv4_is_multicast(fl4->saddr) || 2396 ipv4_is_lbcast(fl4->saddr) || 2397 ipv4_is_zeronet(fl4->saddr)) 2398 goto out; 2399 2400 /* I removed check for oif == dev_out->oif here. 2401 It was wrong for two reasons: 2402 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2403 is assigned to multiple interfaces. 2404 2. Moreover, we are allowed to send packets with saddr 2405 of another iface. --ANK 2406 */ 2407 2408 if (fl4->flowi4_oif == 0 && 2409 (ipv4_is_multicast(fl4->daddr) || 2410 ipv4_is_lbcast(fl4->daddr))) { 2411 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2412 dev_out = __ip_dev_find(net, fl4->saddr, false); 2413 if (!dev_out) 2414 goto out; 2415 2416 /* Special hack: user can direct multicasts 2417 and limited broadcast via necessary interface 2418 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2419 This hack is not just for fun, it allows 2420 vic,vat and friends to work. 2421 They bind socket to loopback, set ttl to zero 2422 and expect that it will work. 2423 From the viewpoint of routing cache they are broken, 2424 because we are not allowed to build multicast path 2425 with loopback source addr (look, routing cache 2426 cannot know, that ttl is zero, so that packet 2427 will not leave this host and route is valid). 2428 Luckily, this hack is good workaround. 2429 */ 2430 2431 fl4->flowi4_oif = dev_out->ifindex; 2432 goto make_route; 2433 } 2434 2435 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2436 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2437 if (!__ip_dev_find(net, fl4->saddr, false)) 2438 goto out; 2439 } 2440 } 2441 2442 2443 if (fl4->flowi4_oif) { 2444 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2445 rth = ERR_PTR(-ENODEV); 2446 if (!dev_out) 2447 goto out; 2448 2449 /* RACE: Check return value of inet_select_addr instead. */ 2450 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2451 rth = ERR_PTR(-ENETUNREACH); 2452 goto out; 2453 } 2454 if (ipv4_is_local_multicast(fl4->daddr) || 2455 ipv4_is_lbcast(fl4->daddr) || 2456 fl4->flowi4_proto == IPPROTO_IGMP) { 2457 if (!fl4->saddr) 2458 fl4->saddr = inet_select_addr(dev_out, 0, 2459 RT_SCOPE_LINK); 2460 goto make_route; 2461 } 2462 if (!fl4->saddr) { 2463 if (ipv4_is_multicast(fl4->daddr)) 2464 fl4->saddr = inet_select_addr(dev_out, 0, 2465 fl4->flowi4_scope); 2466 else if (!fl4->daddr) 2467 fl4->saddr = inet_select_addr(dev_out, 0, 2468 RT_SCOPE_HOST); 2469 } 2470 } 2471 2472 if (!fl4->daddr) { 2473 fl4->daddr = fl4->saddr; 2474 if (!fl4->daddr) 2475 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2476 dev_out = net->loopback_dev; 2477 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2478 res->type = RTN_LOCAL; 2479 flags |= RTCF_LOCAL; 2480 goto make_route; 2481 } 2482 2483 err = fib_lookup(net, fl4, res, 0); 2484 if (err) { 2485 res->fi = NULL; 2486 res->table = NULL; 2487 if (fl4->flowi4_oif && 2488 (ipv4_is_multicast(fl4->daddr) || 2489 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2490 /* Apparently, routing tables are wrong. Assume, 2491 that the destination is on link. 2492 2493 WHY? DW. 2494 Because we are allowed to send to iface 2495 even if it has NO routes and NO assigned 2496 addresses. When oif is specified, routing 2497 tables are looked up with only one purpose: 2498 to catch if destination is gatewayed, rather than 2499 direct. Moreover, if MSG_DONTROUTE is set, 2500 we send packet, ignoring both routing tables 2501 and ifaddr state. --ANK 2502 2503 2504 We could make it even if oif is unknown, 2505 likely IPv6, but we do not. 2506 */ 2507 2508 if (fl4->saddr == 0) 2509 fl4->saddr = inet_select_addr(dev_out, 0, 2510 RT_SCOPE_LINK); 2511 res->type = RTN_UNICAST; 2512 goto make_route; 2513 } 2514 rth = ERR_PTR(err); 2515 goto out; 2516 } 2517 2518 if (res->type == RTN_LOCAL) { 2519 if (!fl4->saddr) { 2520 if (res->fi->fib_prefsrc) 2521 fl4->saddr = res->fi->fib_prefsrc; 2522 else 2523 fl4->saddr = fl4->daddr; 2524 } 2525 2526 /* L3 master device is the loopback for that domain */ 2527 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2528 net->loopback_dev; 2529 2530 /* make sure orig_oif points to fib result device even 2531 * though packet rx/tx happens over loopback or l3mdev 2532 */ 2533 orig_oif = FIB_RES_OIF(*res); 2534 2535 fl4->flowi4_oif = dev_out->ifindex; 2536 flags |= RTCF_LOCAL; 2537 goto make_route; 2538 } 2539 2540 fib_select_path(net, res, fl4, skb); 2541 2542 dev_out = FIB_RES_DEV(*res); 2543 fl4->flowi4_oif = dev_out->ifindex; 2544 2545 2546 make_route: 2547 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2548 2549 out: 2550 return rth; 2551 } 2552 2553 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2554 { 2555 return NULL; 2556 } 2557 2558 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2559 { 2560 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2561 2562 return mtu ? : dst->dev->mtu; 2563 } 2564 2565 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2566 struct sk_buff *skb, u32 mtu) 2567 { 2568 } 2569 2570 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2571 struct sk_buff *skb) 2572 { 2573 } 2574 2575 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2576 unsigned long old) 2577 { 2578 return NULL; 2579 } 2580 2581 static struct dst_ops ipv4_dst_blackhole_ops = { 2582 .family = AF_INET, 2583 .check = ipv4_blackhole_dst_check, 2584 .mtu = ipv4_blackhole_mtu, 2585 .default_advmss = ipv4_default_advmss, 2586 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2587 .redirect = ipv4_rt_blackhole_redirect, 2588 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2589 .neigh_lookup = ipv4_neigh_lookup, 2590 }; 2591 2592 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2593 { 2594 struct rtable *ort = (struct rtable *) dst_orig; 2595 struct rtable *rt; 2596 2597 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2598 if (rt) { 2599 struct dst_entry *new = &rt->dst; 2600 2601 new->__use = 1; 2602 new->input = dst_discard; 2603 new->output = dst_discard_out; 2604 2605 new->dev = net->loopback_dev; 2606 if (new->dev) 2607 dev_hold(new->dev); 2608 2609 rt->rt_is_input = ort->rt_is_input; 2610 rt->rt_iif = ort->rt_iif; 2611 rt->rt_pmtu = ort->rt_pmtu; 2612 rt->rt_mtu_locked = ort->rt_mtu_locked; 2613 2614 rt->rt_genid = rt_genid_ipv4(net); 2615 rt->rt_flags = ort->rt_flags; 2616 rt->rt_type = ort->rt_type; 2617 rt->rt_gw_family = ort->rt_gw_family; 2618 if (rt->rt_gw_family == AF_INET) 2619 rt->rt_gw4 = ort->rt_gw4; 2620 else if (rt->rt_gw_family == AF_INET6) 2621 rt->rt_gw6 = ort->rt_gw6; 2622 2623 INIT_LIST_HEAD(&rt->rt_uncached); 2624 } 2625 2626 dst_release(dst_orig); 2627 2628 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2629 } 2630 2631 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2632 const struct sock *sk) 2633 { 2634 struct rtable *rt = __ip_route_output_key(net, flp4); 2635 2636 if (IS_ERR(rt)) 2637 return rt; 2638 2639 if (flp4->flowi4_proto) 2640 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2641 flowi4_to_flowi(flp4), 2642 sk, 0); 2643 2644 return rt; 2645 } 2646 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2647 2648 /* called with rcu_read_lock held */ 2649 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2650 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2651 struct sk_buff *skb, u32 portid, u32 seq) 2652 { 2653 struct rtmsg *r; 2654 struct nlmsghdr *nlh; 2655 unsigned long expires = 0; 2656 u32 error; 2657 u32 metrics[RTAX_MAX]; 2658 2659 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2660 if (!nlh) 2661 return -EMSGSIZE; 2662 2663 r = nlmsg_data(nlh); 2664 r->rtm_family = AF_INET; 2665 r->rtm_dst_len = 32; 2666 r->rtm_src_len = 0; 2667 r->rtm_tos = fl4->flowi4_tos; 2668 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2669 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2670 goto nla_put_failure; 2671 r->rtm_type = rt->rt_type; 2672 r->rtm_scope = RT_SCOPE_UNIVERSE; 2673 r->rtm_protocol = RTPROT_UNSPEC; 2674 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2675 if (rt->rt_flags & RTCF_NOTIFY) 2676 r->rtm_flags |= RTM_F_NOTIFY; 2677 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2678 r->rtm_flags |= RTCF_DOREDIRECT; 2679 2680 if (nla_put_in_addr(skb, RTA_DST, dst)) 2681 goto nla_put_failure; 2682 if (src) { 2683 r->rtm_src_len = 32; 2684 if (nla_put_in_addr(skb, RTA_SRC, src)) 2685 goto nla_put_failure; 2686 } 2687 if (rt->dst.dev && 2688 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2689 goto nla_put_failure; 2690 #ifdef CONFIG_IP_ROUTE_CLASSID 2691 if (rt->dst.tclassid && 2692 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2693 goto nla_put_failure; 2694 #endif 2695 if (!rt_is_input_route(rt) && 2696 fl4->saddr != src) { 2697 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2698 goto nla_put_failure; 2699 } 2700 if (rt->rt_gw_family == AF_INET && 2701 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2702 goto nla_put_failure; 2703 } else if (rt->rt_gw_family == AF_INET6) { 2704 int alen = sizeof(struct in6_addr); 2705 struct nlattr *nla; 2706 struct rtvia *via; 2707 2708 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2709 if (!nla) 2710 goto nla_put_failure; 2711 2712 via = nla_data(nla); 2713 via->rtvia_family = AF_INET6; 2714 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2715 } 2716 2717 expires = rt->dst.expires; 2718 if (expires) { 2719 unsigned long now = jiffies; 2720 2721 if (time_before(now, expires)) 2722 expires -= now; 2723 else 2724 expires = 0; 2725 } 2726 2727 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2728 if (rt->rt_pmtu && expires) 2729 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2730 if (rt->rt_mtu_locked && expires) 2731 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2732 if (rtnetlink_put_metrics(skb, metrics) < 0) 2733 goto nla_put_failure; 2734 2735 if (fl4->flowi4_mark && 2736 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2737 goto nla_put_failure; 2738 2739 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2740 nla_put_u32(skb, RTA_UID, 2741 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2742 goto nla_put_failure; 2743 2744 error = rt->dst.error; 2745 2746 if (rt_is_input_route(rt)) { 2747 #ifdef CONFIG_IP_MROUTE 2748 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2749 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2750 int err = ipmr_get_route(net, skb, 2751 fl4->saddr, fl4->daddr, 2752 r, portid); 2753 2754 if (err <= 0) { 2755 if (err == 0) 2756 return 0; 2757 goto nla_put_failure; 2758 } 2759 } else 2760 #endif 2761 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2762 goto nla_put_failure; 2763 } 2764 2765 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2766 goto nla_put_failure; 2767 2768 nlmsg_end(skb, nlh); 2769 return 0; 2770 2771 nla_put_failure: 2772 nlmsg_cancel(skb, nlh); 2773 return -EMSGSIZE; 2774 } 2775 2776 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2777 u8 ip_proto, __be16 sport, 2778 __be16 dport) 2779 { 2780 struct sk_buff *skb; 2781 struct iphdr *iph; 2782 2783 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2784 if (!skb) 2785 return NULL; 2786 2787 /* Reserve room for dummy headers, this skb can pass 2788 * through good chunk of routing engine. 2789 */ 2790 skb_reset_mac_header(skb); 2791 skb_reset_network_header(skb); 2792 skb->protocol = htons(ETH_P_IP); 2793 iph = skb_put(skb, sizeof(struct iphdr)); 2794 iph->protocol = ip_proto; 2795 iph->saddr = src; 2796 iph->daddr = dst; 2797 iph->version = 0x4; 2798 iph->frag_off = 0; 2799 iph->ihl = 0x5; 2800 skb_set_transport_header(skb, skb->len); 2801 2802 switch (iph->protocol) { 2803 case IPPROTO_UDP: { 2804 struct udphdr *udph; 2805 2806 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2807 udph->source = sport; 2808 udph->dest = dport; 2809 udph->len = sizeof(struct udphdr); 2810 udph->check = 0; 2811 break; 2812 } 2813 case IPPROTO_TCP: { 2814 struct tcphdr *tcph; 2815 2816 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2817 tcph->source = sport; 2818 tcph->dest = dport; 2819 tcph->doff = sizeof(struct tcphdr) / 4; 2820 tcph->rst = 1; 2821 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2822 src, dst, 0); 2823 break; 2824 } 2825 case IPPROTO_ICMP: { 2826 struct icmphdr *icmph; 2827 2828 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2829 icmph->type = ICMP_ECHO; 2830 icmph->code = 0; 2831 } 2832 } 2833 2834 return skb; 2835 } 2836 2837 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 2838 const struct nlmsghdr *nlh, 2839 struct nlattr **tb, 2840 struct netlink_ext_ack *extack) 2841 { 2842 struct rtmsg *rtm; 2843 int i, err; 2844 2845 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 2846 NL_SET_ERR_MSG(extack, 2847 "ipv4: Invalid header for route get request"); 2848 return -EINVAL; 2849 } 2850 2851 if (!netlink_strict_get_check(skb)) 2852 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, 2853 rtm_ipv4_policy, extack); 2854 2855 rtm = nlmsg_data(nlh); 2856 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 2857 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 2858 rtm->rtm_table || rtm->rtm_protocol || 2859 rtm->rtm_scope || rtm->rtm_type) { 2860 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 2861 return -EINVAL; 2862 } 2863 2864 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 2865 RTM_F_LOOKUP_TABLE | 2866 RTM_F_FIB_MATCH)) { 2867 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 2868 return -EINVAL; 2869 } 2870 2871 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 2872 rtm_ipv4_policy, extack); 2873 if (err) 2874 return err; 2875 2876 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 2877 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 2878 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 2879 return -EINVAL; 2880 } 2881 2882 for (i = 0; i <= RTA_MAX; i++) { 2883 if (!tb[i]) 2884 continue; 2885 2886 switch (i) { 2887 case RTA_IIF: 2888 case RTA_OIF: 2889 case RTA_SRC: 2890 case RTA_DST: 2891 case RTA_IP_PROTO: 2892 case RTA_SPORT: 2893 case RTA_DPORT: 2894 case RTA_MARK: 2895 case RTA_UID: 2896 break; 2897 default: 2898 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 2899 return -EINVAL; 2900 } 2901 } 2902 2903 return 0; 2904 } 2905 2906 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2907 struct netlink_ext_ack *extack) 2908 { 2909 struct net *net = sock_net(in_skb->sk); 2910 struct nlattr *tb[RTA_MAX+1]; 2911 u32 table_id = RT_TABLE_MAIN; 2912 __be16 sport = 0, dport = 0; 2913 struct fib_result res = {}; 2914 u8 ip_proto = IPPROTO_UDP; 2915 struct rtable *rt = NULL; 2916 struct sk_buff *skb; 2917 struct rtmsg *rtm; 2918 struct flowi4 fl4 = {}; 2919 __be32 dst = 0; 2920 __be32 src = 0; 2921 kuid_t uid; 2922 u32 iif; 2923 int err; 2924 int mark; 2925 2926 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 2927 if (err < 0) 2928 return err; 2929 2930 rtm = nlmsg_data(nlh); 2931 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2932 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2933 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2934 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2935 if (tb[RTA_UID]) 2936 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2937 else 2938 uid = (iif ? INVALID_UID : current_uid()); 2939 2940 if (tb[RTA_IP_PROTO]) { 2941 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2942 &ip_proto, AF_INET, extack); 2943 if (err) 2944 return err; 2945 } 2946 2947 if (tb[RTA_SPORT]) 2948 sport = nla_get_be16(tb[RTA_SPORT]); 2949 2950 if (tb[RTA_DPORT]) 2951 dport = nla_get_be16(tb[RTA_DPORT]); 2952 2953 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2954 if (!skb) 2955 return -ENOBUFS; 2956 2957 fl4.daddr = dst; 2958 fl4.saddr = src; 2959 fl4.flowi4_tos = rtm->rtm_tos; 2960 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2961 fl4.flowi4_mark = mark; 2962 fl4.flowi4_uid = uid; 2963 if (sport) 2964 fl4.fl4_sport = sport; 2965 if (dport) 2966 fl4.fl4_dport = dport; 2967 fl4.flowi4_proto = ip_proto; 2968 2969 rcu_read_lock(); 2970 2971 if (iif) { 2972 struct net_device *dev; 2973 2974 dev = dev_get_by_index_rcu(net, iif); 2975 if (!dev) { 2976 err = -ENODEV; 2977 goto errout_rcu; 2978 } 2979 2980 fl4.flowi4_iif = iif; /* for rt_fill_info */ 2981 skb->dev = dev; 2982 skb->mark = mark; 2983 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 2984 dev, &res); 2985 2986 rt = skb_rtable(skb); 2987 if (err == 0 && rt->dst.error) 2988 err = -rt->dst.error; 2989 } else { 2990 fl4.flowi4_iif = LOOPBACK_IFINDEX; 2991 skb->dev = net->loopback_dev; 2992 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 2993 err = 0; 2994 if (IS_ERR(rt)) 2995 err = PTR_ERR(rt); 2996 else 2997 skb_dst_set(skb, &rt->dst); 2998 } 2999 3000 if (err) 3001 goto errout_rcu; 3002 3003 if (rtm->rtm_flags & RTM_F_NOTIFY) 3004 rt->rt_flags |= RTCF_NOTIFY; 3005 3006 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3007 table_id = res.table ? res.table->tb_id : 0; 3008 3009 /* reset skb for netlink reply msg */ 3010 skb_trim(skb, 0); 3011 skb_reset_network_header(skb); 3012 skb_reset_transport_header(skb); 3013 skb_reset_mac_header(skb); 3014 3015 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3016 if (!res.fi) { 3017 err = fib_props[res.type].error; 3018 if (!err) 3019 err = -EHOSTUNREACH; 3020 goto errout_rcu; 3021 } 3022 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3023 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 3024 rt->rt_type, res.prefix, res.prefixlen, 3025 fl4.flowi4_tos, res.fi, 0); 3026 } else { 3027 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3028 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 3029 } 3030 if (err < 0) 3031 goto errout_rcu; 3032 3033 rcu_read_unlock(); 3034 3035 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3036 3037 errout_free: 3038 return err; 3039 errout_rcu: 3040 rcu_read_unlock(); 3041 kfree_skb(skb); 3042 goto errout_free; 3043 } 3044 3045 void ip_rt_multicast_event(struct in_device *in_dev) 3046 { 3047 rt_cache_flush(dev_net(in_dev->dev)); 3048 } 3049 3050 #ifdef CONFIG_SYSCTL 3051 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3052 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3053 static int ip_rt_gc_elasticity __read_mostly = 8; 3054 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3055 3056 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3057 void __user *buffer, 3058 size_t *lenp, loff_t *ppos) 3059 { 3060 struct net *net = (struct net *)__ctl->extra1; 3061 3062 if (write) { 3063 rt_cache_flush(net); 3064 fnhe_genid_bump(net); 3065 return 0; 3066 } 3067 3068 return -EINVAL; 3069 } 3070 3071 static struct ctl_table ipv4_route_table[] = { 3072 { 3073 .procname = "gc_thresh", 3074 .data = &ipv4_dst_ops.gc_thresh, 3075 .maxlen = sizeof(int), 3076 .mode = 0644, 3077 .proc_handler = proc_dointvec, 3078 }, 3079 { 3080 .procname = "max_size", 3081 .data = &ip_rt_max_size, 3082 .maxlen = sizeof(int), 3083 .mode = 0644, 3084 .proc_handler = proc_dointvec, 3085 }, 3086 { 3087 /* Deprecated. Use gc_min_interval_ms */ 3088 3089 .procname = "gc_min_interval", 3090 .data = &ip_rt_gc_min_interval, 3091 .maxlen = sizeof(int), 3092 .mode = 0644, 3093 .proc_handler = proc_dointvec_jiffies, 3094 }, 3095 { 3096 .procname = "gc_min_interval_ms", 3097 .data = &ip_rt_gc_min_interval, 3098 .maxlen = sizeof(int), 3099 .mode = 0644, 3100 .proc_handler = proc_dointvec_ms_jiffies, 3101 }, 3102 { 3103 .procname = "gc_timeout", 3104 .data = &ip_rt_gc_timeout, 3105 .maxlen = sizeof(int), 3106 .mode = 0644, 3107 .proc_handler = proc_dointvec_jiffies, 3108 }, 3109 { 3110 .procname = "gc_interval", 3111 .data = &ip_rt_gc_interval, 3112 .maxlen = sizeof(int), 3113 .mode = 0644, 3114 .proc_handler = proc_dointvec_jiffies, 3115 }, 3116 { 3117 .procname = "redirect_load", 3118 .data = &ip_rt_redirect_load, 3119 .maxlen = sizeof(int), 3120 .mode = 0644, 3121 .proc_handler = proc_dointvec, 3122 }, 3123 { 3124 .procname = "redirect_number", 3125 .data = &ip_rt_redirect_number, 3126 .maxlen = sizeof(int), 3127 .mode = 0644, 3128 .proc_handler = proc_dointvec, 3129 }, 3130 { 3131 .procname = "redirect_silence", 3132 .data = &ip_rt_redirect_silence, 3133 .maxlen = sizeof(int), 3134 .mode = 0644, 3135 .proc_handler = proc_dointvec, 3136 }, 3137 { 3138 .procname = "error_cost", 3139 .data = &ip_rt_error_cost, 3140 .maxlen = sizeof(int), 3141 .mode = 0644, 3142 .proc_handler = proc_dointvec, 3143 }, 3144 { 3145 .procname = "error_burst", 3146 .data = &ip_rt_error_burst, 3147 .maxlen = sizeof(int), 3148 .mode = 0644, 3149 .proc_handler = proc_dointvec, 3150 }, 3151 { 3152 .procname = "gc_elasticity", 3153 .data = &ip_rt_gc_elasticity, 3154 .maxlen = sizeof(int), 3155 .mode = 0644, 3156 .proc_handler = proc_dointvec, 3157 }, 3158 { 3159 .procname = "mtu_expires", 3160 .data = &ip_rt_mtu_expires, 3161 .maxlen = sizeof(int), 3162 .mode = 0644, 3163 .proc_handler = proc_dointvec_jiffies, 3164 }, 3165 { 3166 .procname = "min_pmtu", 3167 .data = &ip_rt_min_pmtu, 3168 .maxlen = sizeof(int), 3169 .mode = 0644, 3170 .proc_handler = proc_dointvec_minmax, 3171 .extra1 = &ip_min_valid_pmtu, 3172 }, 3173 { 3174 .procname = "min_adv_mss", 3175 .data = &ip_rt_min_advmss, 3176 .maxlen = sizeof(int), 3177 .mode = 0644, 3178 .proc_handler = proc_dointvec, 3179 }, 3180 { } 3181 }; 3182 3183 static struct ctl_table ipv4_route_flush_table[] = { 3184 { 3185 .procname = "flush", 3186 .maxlen = sizeof(int), 3187 .mode = 0200, 3188 .proc_handler = ipv4_sysctl_rtcache_flush, 3189 }, 3190 { }, 3191 }; 3192 3193 static __net_init int sysctl_route_net_init(struct net *net) 3194 { 3195 struct ctl_table *tbl; 3196 3197 tbl = ipv4_route_flush_table; 3198 if (!net_eq(net, &init_net)) { 3199 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3200 if (!tbl) 3201 goto err_dup; 3202 3203 /* Don't export sysctls to unprivileged users */ 3204 if (net->user_ns != &init_user_ns) 3205 tbl[0].procname = NULL; 3206 } 3207 tbl[0].extra1 = net; 3208 3209 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3210 if (!net->ipv4.route_hdr) 3211 goto err_reg; 3212 return 0; 3213 3214 err_reg: 3215 if (tbl != ipv4_route_flush_table) 3216 kfree(tbl); 3217 err_dup: 3218 return -ENOMEM; 3219 } 3220 3221 static __net_exit void sysctl_route_net_exit(struct net *net) 3222 { 3223 struct ctl_table *tbl; 3224 3225 tbl = net->ipv4.route_hdr->ctl_table_arg; 3226 unregister_net_sysctl_table(net->ipv4.route_hdr); 3227 BUG_ON(tbl == ipv4_route_flush_table); 3228 kfree(tbl); 3229 } 3230 3231 static __net_initdata struct pernet_operations sysctl_route_ops = { 3232 .init = sysctl_route_net_init, 3233 .exit = sysctl_route_net_exit, 3234 }; 3235 #endif 3236 3237 static __net_init int rt_genid_init(struct net *net) 3238 { 3239 atomic_set(&net->ipv4.rt_genid, 0); 3240 atomic_set(&net->fnhe_genid, 0); 3241 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3242 return 0; 3243 } 3244 3245 static __net_initdata struct pernet_operations rt_genid_ops = { 3246 .init = rt_genid_init, 3247 }; 3248 3249 static int __net_init ipv4_inetpeer_init(struct net *net) 3250 { 3251 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3252 3253 if (!bp) 3254 return -ENOMEM; 3255 inet_peer_base_init(bp); 3256 net->ipv4.peers = bp; 3257 return 0; 3258 } 3259 3260 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3261 { 3262 struct inet_peer_base *bp = net->ipv4.peers; 3263 3264 net->ipv4.peers = NULL; 3265 inetpeer_invalidate_tree(bp); 3266 kfree(bp); 3267 } 3268 3269 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3270 .init = ipv4_inetpeer_init, 3271 .exit = ipv4_inetpeer_exit, 3272 }; 3273 3274 #ifdef CONFIG_IP_ROUTE_CLASSID 3275 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3276 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3277 3278 int __init ip_rt_init(void) 3279 { 3280 int cpu; 3281 3282 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3283 GFP_KERNEL); 3284 if (!ip_idents) 3285 panic("IP: failed to allocate ip_idents\n"); 3286 3287 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3288 3289 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3290 if (!ip_tstamps) 3291 panic("IP: failed to allocate ip_tstamps\n"); 3292 3293 for_each_possible_cpu(cpu) { 3294 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3295 3296 INIT_LIST_HEAD(&ul->head); 3297 spin_lock_init(&ul->lock); 3298 } 3299 #ifdef CONFIG_IP_ROUTE_CLASSID 3300 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3301 if (!ip_rt_acct) 3302 panic("IP: failed to allocate ip_rt_acct\n"); 3303 #endif 3304 3305 ipv4_dst_ops.kmem_cachep = 3306 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3307 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3308 3309 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3310 3311 if (dst_entries_init(&ipv4_dst_ops) < 0) 3312 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3313 3314 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3315 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3316 3317 ipv4_dst_ops.gc_thresh = ~0; 3318 ip_rt_max_size = INT_MAX; 3319 3320 devinet_init(); 3321 ip_fib_init(); 3322 3323 if (ip_rt_proc_init()) 3324 pr_err("Unable to create route proc files\n"); 3325 #ifdef CONFIG_XFRM 3326 xfrm_init(); 3327 xfrm4_init(); 3328 #endif 3329 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3330 RTNL_FLAG_DOIT_UNLOCKED); 3331 3332 #ifdef CONFIG_SYSCTL 3333 register_pernet_subsys(&sysctl_route_ops); 3334 #endif 3335 register_pernet_subsys(&rt_genid_ops); 3336 register_pernet_subsys(&ipv4_inetpeer_ops); 3337 return 0; 3338 } 3339 3340 #ifdef CONFIG_SYSCTL 3341 /* 3342 * We really need to sanitize the damn ipv4 init order, then all 3343 * this nonsense will go away. 3344 */ 3345 void __init ip_static_sysctl_init(void) 3346 { 3347 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3348 } 3349 #endif 3350