1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * ROUTE - implementation of the IP router. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Alan Cox, <gw4pts@gw4pts.ampr.org> 12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 14 * 15 * Fixes: 16 * Alan Cox : Verify area fixes. 17 * Alan Cox : cli() protects routing changes 18 * Rui Oliveira : ICMP routing table updates 19 * (rco@di.uminho.pt) Routing table insertion and update 20 * Linus Torvalds : Rewrote bits to be sensible 21 * Alan Cox : Added BSD route gw semantics 22 * Alan Cox : Super /proc >4K 23 * Alan Cox : MTU in route table 24 * Alan Cox : MSS actually. Also added the window 25 * clamper. 26 * Sam Lantinga : Fixed route matching in rt_del() 27 * Alan Cox : Routing cache support. 28 * Alan Cox : Removed compatibility cruft. 29 * Alan Cox : RTF_REJECT support. 30 * Alan Cox : TCP irtt support. 31 * Jonathan Naylor : Added Metric support. 32 * Miquel van Smoorenburg : BSD API fixes. 33 * Miquel van Smoorenburg : Metrics. 34 * Alan Cox : Use __u32 properly 35 * Alan Cox : Aligned routing errors more closely with BSD 36 * our system is still very different. 37 * Alan Cox : Faster /proc handling 38 * Alexey Kuznetsov : Massive rework to support tree based routing, 39 * routing caches and better behaviour. 40 * 41 * Olaf Erb : irtt wasn't being copied right. 42 * Bjorn Ekwall : Kerneld route support. 43 * Alan Cox : Multicast fixed (I hope) 44 * Pavel Krauz : Limited broadcast fixed 45 * Mike McLagan : Routing by source 46 * Alexey Kuznetsov : End of old history. Split to fib.c and 47 * route.c and rewritten from scratch. 48 * Andi Kleen : Load-limit warning messages. 49 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 53 * Marc Boucher : routing by fwmark 54 * Robert Olsson : Added rt_cache statistics 55 * Arnaldo C. Melo : Convert proc stuff to seq_file 56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 58 * Ilia Sotnikov : Removed TOS from hash calculations 59 */ 60 61 #define pr_fmt(fmt) "IPv4: " fmt 62 63 #include <linux/module.h> 64 #include <linux/uaccess.h> 65 #include <linux/bitops.h> 66 #include <linux/types.h> 67 #include <linux/kernel.h> 68 #include <linux/mm.h> 69 #include <linux/string.h> 70 #include <linux/socket.h> 71 #include <linux/sockios.h> 72 #include <linux/errno.h> 73 #include <linux/in.h> 74 #include <linux/inet.h> 75 #include <linux/netdevice.h> 76 #include <linux/proc_fs.h> 77 #include <linux/init.h> 78 #include <linux/skbuff.h> 79 #include <linux/inetdevice.h> 80 #include <linux/igmp.h> 81 #include <linux/pkt_sched.h> 82 #include <linux/mroute.h> 83 #include <linux/netfilter_ipv4.h> 84 #include <linux/random.h> 85 #include <linux/rcupdate.h> 86 #include <linux/times.h> 87 #include <linux/slab.h> 88 #include <linux/jhash.h> 89 #include <net/dst.h> 90 #include <net/dst_metadata.h> 91 #include <net/net_namespace.h> 92 #include <net/protocol.h> 93 #include <net/ip.h> 94 #include <net/route.h> 95 #include <net/inetpeer.h> 96 #include <net/sock.h> 97 #include <net/ip_fib.h> 98 #include <net/nexthop.h> 99 #include <net/arp.h> 100 #include <net/tcp.h> 101 #include <net/icmp.h> 102 #include <net/xfrm.h> 103 #include <net/lwtunnel.h> 104 #include <net/netevent.h> 105 #include <net/rtnetlink.h> 106 #ifdef CONFIG_SYSCTL 107 #include <linux/sysctl.h> 108 #endif 109 #include <net/secure_seq.h> 110 #include <net/ip_tunnels.h> 111 #include <net/l3mdev.h> 112 113 #include "fib_lookup.h" 114 115 #define RT_FL_TOS(oldflp4) \ 116 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 117 118 #define RT_GC_TIMEOUT (300*HZ) 119 120 static int ip_rt_max_size; 121 static int ip_rt_redirect_number __read_mostly = 9; 122 static int ip_rt_redirect_load __read_mostly = HZ / 50; 123 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 124 static int ip_rt_error_cost __read_mostly = HZ; 125 static int ip_rt_error_burst __read_mostly = 5 * HZ; 126 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 127 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 128 static int ip_rt_min_advmss __read_mostly = 256; 129 130 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 131 132 /* 133 * Interface to generic destination cache. 134 */ 135 136 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 137 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 138 static unsigned int ipv4_mtu(const struct dst_entry *dst); 139 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 140 static void ipv4_link_failure(struct sk_buff *skb); 141 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 142 struct sk_buff *skb, u32 mtu); 143 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, 144 struct sk_buff *skb); 145 static void ipv4_dst_destroy(struct dst_entry *dst); 146 147 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 148 { 149 WARN_ON(1); 150 return NULL; 151 } 152 153 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 154 struct sk_buff *skb, 155 const void *daddr); 156 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr); 157 158 static struct dst_ops ipv4_dst_ops = { 159 .family = AF_INET, 160 .check = ipv4_dst_check, 161 .default_advmss = ipv4_default_advmss, 162 .mtu = ipv4_mtu, 163 .cow_metrics = ipv4_cow_metrics, 164 .destroy = ipv4_dst_destroy, 165 .negative_advice = ipv4_negative_advice, 166 .link_failure = ipv4_link_failure, 167 .update_pmtu = ip_rt_update_pmtu, 168 .redirect = ip_do_redirect, 169 .local_out = __ip_local_out, 170 .neigh_lookup = ipv4_neigh_lookup, 171 .confirm_neigh = ipv4_confirm_neigh, 172 }; 173 174 #define ECN_OR_COST(class) TC_PRIO_##class 175 176 const __u8 ip_tos2prio[16] = { 177 TC_PRIO_BESTEFFORT, 178 ECN_OR_COST(BESTEFFORT), 179 TC_PRIO_BESTEFFORT, 180 ECN_OR_COST(BESTEFFORT), 181 TC_PRIO_BULK, 182 ECN_OR_COST(BULK), 183 TC_PRIO_BULK, 184 ECN_OR_COST(BULK), 185 TC_PRIO_INTERACTIVE, 186 ECN_OR_COST(INTERACTIVE), 187 TC_PRIO_INTERACTIVE, 188 ECN_OR_COST(INTERACTIVE), 189 TC_PRIO_INTERACTIVE_BULK, 190 ECN_OR_COST(INTERACTIVE_BULK), 191 TC_PRIO_INTERACTIVE_BULK, 192 ECN_OR_COST(INTERACTIVE_BULK) 193 }; 194 EXPORT_SYMBOL(ip_tos2prio); 195 196 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 197 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field) 198 199 #ifdef CONFIG_PROC_FS 200 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 201 { 202 if (*pos) 203 return NULL; 204 return SEQ_START_TOKEN; 205 } 206 207 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 208 { 209 ++*pos; 210 return NULL; 211 } 212 213 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 214 { 215 } 216 217 static int rt_cache_seq_show(struct seq_file *seq, void *v) 218 { 219 if (v == SEQ_START_TOKEN) 220 seq_printf(seq, "%-127s\n", 221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 223 "HHUptod\tSpecDst"); 224 return 0; 225 } 226 227 static const struct seq_operations rt_cache_seq_ops = { 228 .start = rt_cache_seq_start, 229 .next = rt_cache_seq_next, 230 .stop = rt_cache_seq_stop, 231 .show = rt_cache_seq_show, 232 }; 233 234 static int rt_cache_seq_open(struct inode *inode, struct file *file) 235 { 236 return seq_open(file, &rt_cache_seq_ops); 237 } 238 239 static const struct file_operations rt_cache_seq_fops = { 240 .open = rt_cache_seq_open, 241 .read = seq_read, 242 .llseek = seq_lseek, 243 .release = seq_release, 244 }; 245 246 247 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 248 { 249 int cpu; 250 251 if (*pos == 0) 252 return SEQ_START_TOKEN; 253 254 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 255 if (!cpu_possible(cpu)) 256 continue; 257 *pos = cpu+1; 258 return &per_cpu(rt_cache_stat, cpu); 259 } 260 return NULL; 261 } 262 263 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 264 { 265 int cpu; 266 267 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 268 if (!cpu_possible(cpu)) 269 continue; 270 *pos = cpu+1; 271 return &per_cpu(rt_cache_stat, cpu); 272 } 273 return NULL; 274 275 } 276 277 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 278 { 279 280 } 281 282 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 283 { 284 struct rt_cache_stat *st = v; 285 286 if (v == SEQ_START_TOKEN) { 287 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"); 288 return 0; 289 } 290 291 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 292 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 293 dst_entries_get_slow(&ipv4_dst_ops), 294 0, /* st->in_hit */ 295 st->in_slow_tot, 296 st->in_slow_mc, 297 st->in_no_route, 298 st->in_brd, 299 st->in_martian_dst, 300 st->in_martian_src, 301 302 0, /* st->out_hit */ 303 st->out_slow_tot, 304 st->out_slow_mc, 305 306 0, /* st->gc_total */ 307 0, /* st->gc_ignored */ 308 0, /* st->gc_goal_miss */ 309 0, /* st->gc_dst_overflow */ 310 0, /* st->in_hlist_search */ 311 0 /* st->out_hlist_search */ 312 ); 313 return 0; 314 } 315 316 static const struct seq_operations rt_cpu_seq_ops = { 317 .start = rt_cpu_seq_start, 318 .next = rt_cpu_seq_next, 319 .stop = rt_cpu_seq_stop, 320 .show = rt_cpu_seq_show, 321 }; 322 323 324 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 325 { 326 return seq_open(file, &rt_cpu_seq_ops); 327 } 328 329 static const struct file_operations rt_cpu_seq_fops = { 330 .open = rt_cpu_seq_open, 331 .read = seq_read, 332 .llseek = seq_lseek, 333 .release = seq_release, 334 }; 335 336 #ifdef CONFIG_IP_ROUTE_CLASSID 337 static int rt_acct_proc_show(struct seq_file *m, void *v) 338 { 339 struct ip_rt_acct *dst, *src; 340 unsigned int i, j; 341 342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 343 if (!dst) 344 return -ENOMEM; 345 346 for_each_possible_cpu(i) { 347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 348 for (j = 0; j < 256; j++) { 349 dst[j].o_bytes += src[j].o_bytes; 350 dst[j].o_packets += src[j].o_packets; 351 dst[j].i_bytes += src[j].i_bytes; 352 dst[j].i_packets += src[j].i_packets; 353 } 354 } 355 356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 357 kfree(dst); 358 return 0; 359 } 360 #endif 361 362 static int __net_init ip_rt_do_proc_init(struct net *net) 363 { 364 struct proc_dir_entry *pde; 365 366 pde = proc_create("rt_cache", 0444, net->proc_net, 367 &rt_cache_seq_fops); 368 if (!pde) 369 goto err1; 370 371 pde = proc_create("rt_cache", 0444, 372 net->proc_net_stat, &rt_cpu_seq_fops); 373 if (!pde) 374 goto err2; 375 376 #ifdef CONFIG_IP_ROUTE_CLASSID 377 pde = proc_create_single("rt_acct", 0, net->proc_net, 378 rt_acct_proc_show); 379 if (!pde) 380 goto err3; 381 #endif 382 return 0; 383 384 #ifdef CONFIG_IP_ROUTE_CLASSID 385 err3: 386 remove_proc_entry("rt_cache", net->proc_net_stat); 387 #endif 388 err2: 389 remove_proc_entry("rt_cache", net->proc_net); 390 err1: 391 return -ENOMEM; 392 } 393 394 static void __net_exit ip_rt_do_proc_exit(struct net *net) 395 { 396 remove_proc_entry("rt_cache", net->proc_net_stat); 397 remove_proc_entry("rt_cache", net->proc_net); 398 #ifdef CONFIG_IP_ROUTE_CLASSID 399 remove_proc_entry("rt_acct", net->proc_net); 400 #endif 401 } 402 403 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 404 .init = ip_rt_do_proc_init, 405 .exit = ip_rt_do_proc_exit, 406 }; 407 408 static int __init ip_rt_proc_init(void) 409 { 410 return register_pernet_subsys(&ip_rt_proc_ops); 411 } 412 413 #else 414 static inline int ip_rt_proc_init(void) 415 { 416 return 0; 417 } 418 #endif /* CONFIG_PROC_FS */ 419 420 static inline bool rt_is_expired(const struct rtable *rth) 421 { 422 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev)); 423 } 424 425 void rt_cache_flush(struct net *net) 426 { 427 rt_genid_bump_ipv4(net); 428 } 429 430 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, 431 struct sk_buff *skb, 432 const void *daddr) 433 { 434 const struct rtable *rt = container_of(dst, struct rtable, dst); 435 struct net_device *dev = dst->dev; 436 struct neighbour *n; 437 438 rcu_read_lock_bh(); 439 440 if (likely(rt->rt_gw_family == AF_INET)) { 441 n = ip_neigh_gw4(dev, rt->rt_gw4); 442 } else if (rt->rt_gw_family == AF_INET6) { 443 n = ip_neigh_gw6(dev, &rt->rt_gw6); 444 } else { 445 __be32 pkey; 446 447 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr); 448 n = ip_neigh_gw4(dev, pkey); 449 } 450 451 if (n && !refcount_inc_not_zero(&n->refcnt)) 452 n = NULL; 453 454 rcu_read_unlock_bh(); 455 456 return n; 457 } 458 459 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr) 460 { 461 const struct rtable *rt = container_of(dst, struct rtable, dst); 462 struct net_device *dev = dst->dev; 463 const __be32 *pkey = daddr; 464 465 if (rt->rt_gw_family == AF_INET) { 466 pkey = (const __be32 *)&rt->rt_gw4; 467 } else if (rt->rt_gw_family == AF_INET6) { 468 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6); 469 } else if (!daddr || 470 (rt->rt_flags & 471 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) { 472 return; 473 } 474 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey); 475 } 476 477 #define IP_IDENTS_SZ 2048u 478 479 static atomic_t *ip_idents __read_mostly; 480 static u32 *ip_tstamps __read_mostly; 481 482 /* In order to protect privacy, we add a perturbation to identifiers 483 * if one generator is seldom used. This makes hard for an attacker 484 * to infer how many packets were sent between two points in time. 485 */ 486 u32 ip_idents_reserve(u32 hash, int segs) 487 { 488 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ; 489 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ; 490 u32 old = READ_ONCE(*p_tstamp); 491 u32 now = (u32)jiffies; 492 u32 new, delta = 0; 493 494 if (old != now && cmpxchg(p_tstamp, old, now) == old) 495 delta = prandom_u32_max(now - old); 496 497 /* Do not use atomic_add_return() as it makes UBSAN unhappy */ 498 do { 499 old = (u32)atomic_read(p_id); 500 new = old + delta + segs; 501 } while (atomic_cmpxchg(p_id, old, new) != old); 502 503 return new - segs; 504 } 505 EXPORT_SYMBOL(ip_idents_reserve); 506 507 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs) 508 { 509 u32 hash, id; 510 511 /* Note the following code is not safe, but this is okay. */ 512 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) 513 get_random_bytes(&net->ipv4.ip_id_key, 514 sizeof(net->ipv4.ip_id_key)); 515 516 hash = siphash_3u32((__force u32)iph->daddr, 517 (__force u32)iph->saddr, 518 iph->protocol, 519 &net->ipv4.ip_id_key); 520 id = ip_idents_reserve(hash, segs); 521 iph->id = htons(id); 522 } 523 EXPORT_SYMBOL(__ip_select_ident); 524 525 static void __build_flow_key(const struct net *net, struct flowi4 *fl4, 526 const struct sock *sk, 527 const struct iphdr *iph, 528 int oif, u8 tos, 529 u8 prot, u32 mark, int flow_flags) 530 { 531 if (sk) { 532 const struct inet_sock *inet = inet_sk(sk); 533 534 oif = sk->sk_bound_dev_if; 535 mark = sk->sk_mark; 536 tos = RT_CONN_FLAGS(sk); 537 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol; 538 } 539 flowi4_init_output(fl4, oif, mark, tos, 540 RT_SCOPE_UNIVERSE, prot, 541 flow_flags, 542 iph->daddr, iph->saddr, 0, 0, 543 sock_net_uid(net, sk)); 544 } 545 546 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb, 547 const struct sock *sk) 548 { 549 const struct net *net = dev_net(skb->dev); 550 const struct iphdr *iph = ip_hdr(skb); 551 int oif = skb->dev->ifindex; 552 u8 tos = RT_TOS(iph->tos); 553 u8 prot = iph->protocol; 554 u32 mark = skb->mark; 555 556 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0); 557 } 558 559 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk) 560 { 561 const struct inet_sock *inet = inet_sk(sk); 562 const struct ip_options_rcu *inet_opt; 563 __be32 daddr = inet->inet_daddr; 564 565 rcu_read_lock(); 566 inet_opt = rcu_dereference(inet->inet_opt); 567 if (inet_opt && inet_opt->opt.srr) 568 daddr = inet_opt->opt.faddr; 569 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark, 570 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 571 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol, 572 inet_sk_flowi_flags(sk), 573 daddr, inet->inet_saddr, 0, 0, sk->sk_uid); 574 rcu_read_unlock(); 575 } 576 577 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, 578 const struct sk_buff *skb) 579 { 580 if (skb) 581 build_skb_flow_key(fl4, skb, sk); 582 else 583 build_sk_flow_key(fl4, sk); 584 } 585 586 static DEFINE_SPINLOCK(fnhe_lock); 587 588 static void fnhe_flush_routes(struct fib_nh_exception *fnhe) 589 { 590 struct rtable *rt; 591 592 rt = rcu_dereference(fnhe->fnhe_rth_input); 593 if (rt) { 594 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL); 595 dst_dev_put(&rt->dst); 596 dst_release(&rt->dst); 597 } 598 rt = rcu_dereference(fnhe->fnhe_rth_output); 599 if (rt) { 600 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL); 601 dst_dev_put(&rt->dst); 602 dst_release(&rt->dst); 603 } 604 } 605 606 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) 607 { 608 struct fib_nh_exception *fnhe, *oldest; 609 610 oldest = rcu_dereference(hash->chain); 611 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; 612 fnhe = rcu_dereference(fnhe->fnhe_next)) { 613 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) 614 oldest = fnhe; 615 } 616 fnhe_flush_routes(oldest); 617 return oldest; 618 } 619 620 static inline u32 fnhe_hashfun(__be32 daddr) 621 { 622 static u32 fnhe_hashrnd __read_mostly; 623 u32 hval; 624 625 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd)); 626 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd); 627 return hash_32(hval, FNHE_HASH_SHIFT); 628 } 629 630 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe) 631 { 632 rt->rt_pmtu = fnhe->fnhe_pmtu; 633 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked; 634 rt->dst.expires = fnhe->fnhe_expires; 635 636 if (fnhe->fnhe_gw) { 637 rt->rt_flags |= RTCF_REDIRECTED; 638 rt->rt_gw_family = AF_INET; 639 rt->rt_gw4 = fnhe->fnhe_gw; 640 } 641 } 642 643 static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr, 644 __be32 gw, u32 pmtu, bool lock, 645 unsigned long expires) 646 { 647 struct fnhe_hash_bucket *hash; 648 struct fib_nh_exception *fnhe; 649 struct rtable *rt; 650 u32 genid, hval; 651 unsigned int i; 652 int depth; 653 654 genid = fnhe_genid(dev_net(nhc->nhc_dev)); 655 hval = fnhe_hashfun(daddr); 656 657 spin_lock_bh(&fnhe_lock); 658 659 hash = rcu_dereference(nhc->nhc_exceptions); 660 if (!hash) { 661 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC); 662 if (!hash) 663 goto out_unlock; 664 rcu_assign_pointer(nhc->nhc_exceptions, hash); 665 } 666 667 hash += hval; 668 669 depth = 0; 670 for (fnhe = rcu_dereference(hash->chain); fnhe; 671 fnhe = rcu_dereference(fnhe->fnhe_next)) { 672 if (fnhe->fnhe_daddr == daddr) 673 break; 674 depth++; 675 } 676 677 if (fnhe) { 678 if (fnhe->fnhe_genid != genid) 679 fnhe->fnhe_genid = genid; 680 if (gw) 681 fnhe->fnhe_gw = gw; 682 if (pmtu) { 683 fnhe->fnhe_pmtu = pmtu; 684 fnhe->fnhe_mtu_locked = lock; 685 } 686 fnhe->fnhe_expires = max(1UL, expires); 687 /* Update all cached dsts too */ 688 rt = rcu_dereference(fnhe->fnhe_rth_input); 689 if (rt) 690 fill_route_from_fnhe(rt, fnhe); 691 rt = rcu_dereference(fnhe->fnhe_rth_output); 692 if (rt) 693 fill_route_from_fnhe(rt, fnhe); 694 } else { 695 if (depth > FNHE_RECLAIM_DEPTH) 696 fnhe = fnhe_oldest(hash); 697 else { 698 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC); 699 if (!fnhe) 700 goto out_unlock; 701 702 fnhe->fnhe_next = hash->chain; 703 rcu_assign_pointer(hash->chain, fnhe); 704 } 705 fnhe->fnhe_genid = genid; 706 fnhe->fnhe_daddr = daddr; 707 fnhe->fnhe_gw = gw; 708 fnhe->fnhe_pmtu = pmtu; 709 fnhe->fnhe_mtu_locked = lock; 710 fnhe->fnhe_expires = max(1UL, expires); 711 712 /* Exception created; mark the cached routes for the nexthop 713 * stale, so anyone caching it rechecks if this exception 714 * applies to them. 715 */ 716 rt = rcu_dereference(nhc->nhc_rth_input); 717 if (rt) 718 rt->dst.obsolete = DST_OBSOLETE_KILL; 719 720 for_each_possible_cpu(i) { 721 struct rtable __rcu **prt; 722 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i); 723 rt = rcu_dereference(*prt); 724 if (rt) 725 rt->dst.obsolete = DST_OBSOLETE_KILL; 726 } 727 } 728 729 fnhe->fnhe_stamp = jiffies; 730 731 out_unlock: 732 spin_unlock_bh(&fnhe_lock); 733 } 734 735 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4, 736 bool kill_route) 737 { 738 __be32 new_gw = icmp_hdr(skb)->un.gateway; 739 __be32 old_gw = ip_hdr(skb)->saddr; 740 struct net_device *dev = skb->dev; 741 struct in_device *in_dev; 742 struct fib_result res; 743 struct neighbour *n; 744 struct net *net; 745 746 switch (icmp_hdr(skb)->code & 7) { 747 case ICMP_REDIR_NET: 748 case ICMP_REDIR_NETTOS: 749 case ICMP_REDIR_HOST: 750 case ICMP_REDIR_HOSTTOS: 751 break; 752 753 default: 754 return; 755 } 756 757 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw) 758 return; 759 760 in_dev = __in_dev_get_rcu(dev); 761 if (!in_dev) 762 return; 763 764 net = dev_net(dev); 765 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 766 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 767 ipv4_is_zeronet(new_gw)) 768 goto reject_redirect; 769 770 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 771 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 772 goto reject_redirect; 773 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 774 goto reject_redirect; 775 } else { 776 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 777 goto reject_redirect; 778 } 779 780 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw); 781 if (!n) 782 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev); 783 if (!IS_ERR(n)) { 784 if (!(n->nud_state & NUD_VALID)) { 785 neigh_event_send(n, NULL); 786 } else { 787 if (fib_lookup(net, fl4, &res, 0) == 0) { 788 struct fib_nh_common *nhc = FIB_RES_NHC(res); 789 790 update_or_create_fnhe(nhc, fl4->daddr, new_gw, 791 0, false, 792 jiffies + ip_rt_gc_timeout); 793 } 794 if (kill_route) 795 rt->dst.obsolete = DST_OBSOLETE_KILL; 796 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 797 } 798 neigh_release(n); 799 } 800 return; 801 802 reject_redirect: 803 #ifdef CONFIG_IP_ROUTE_VERBOSE 804 if (IN_DEV_LOG_MARTIANS(in_dev)) { 805 const struct iphdr *iph = (const struct iphdr *) skb->data; 806 __be32 daddr = iph->daddr; 807 __be32 saddr = iph->saddr; 808 809 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n" 810 " Advised path = %pI4 -> %pI4\n", 811 &old_gw, dev->name, &new_gw, 812 &saddr, &daddr); 813 } 814 #endif 815 ; 816 } 817 818 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 819 { 820 struct rtable *rt; 821 struct flowi4 fl4; 822 const struct iphdr *iph = (const struct iphdr *) skb->data; 823 struct net *net = dev_net(skb->dev); 824 int oif = skb->dev->ifindex; 825 u8 tos = RT_TOS(iph->tos); 826 u8 prot = iph->protocol; 827 u32 mark = skb->mark; 828 829 rt = (struct rtable *) dst; 830 831 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0); 832 __ip_do_redirect(rt, skb, &fl4, true); 833 } 834 835 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 836 { 837 struct rtable *rt = (struct rtable *)dst; 838 struct dst_entry *ret = dst; 839 840 if (rt) { 841 if (dst->obsolete > 0) { 842 ip_rt_put(rt); 843 ret = NULL; 844 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 845 rt->dst.expires) { 846 ip_rt_put(rt); 847 ret = NULL; 848 } 849 } 850 return ret; 851 } 852 853 /* 854 * Algorithm: 855 * 1. The first ip_rt_redirect_number redirects are sent 856 * with exponential backoff, then we stop sending them at all, 857 * assuming that the host ignores our redirects. 858 * 2. If we did not see packets requiring redirects 859 * during ip_rt_redirect_silence, we assume that the host 860 * forgot redirected route and start to send redirects again. 861 * 862 * This algorithm is much cheaper and more intelligent than dumb load limiting 863 * in icmp.c. 864 * 865 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 866 * and "frag. need" (breaks PMTU discovery) in icmp.c. 867 */ 868 869 void ip_rt_send_redirect(struct sk_buff *skb) 870 { 871 struct rtable *rt = skb_rtable(skb); 872 struct in_device *in_dev; 873 struct inet_peer *peer; 874 struct net *net; 875 int log_martians; 876 int vif; 877 878 rcu_read_lock(); 879 in_dev = __in_dev_get_rcu(rt->dst.dev); 880 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 881 rcu_read_unlock(); 882 return; 883 } 884 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 885 vif = l3mdev_master_ifindex_rcu(rt->dst.dev); 886 rcu_read_unlock(); 887 888 net = dev_net(rt->dst.dev); 889 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1); 890 if (!peer) { 891 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, 892 rt_nexthop(rt, ip_hdr(skb)->daddr)); 893 return; 894 } 895 896 /* No redirected packets during ip_rt_redirect_silence; 897 * reset the algorithm. 898 */ 899 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) { 900 peer->rate_tokens = 0; 901 peer->n_redirects = 0; 902 } 903 904 /* Too many ignored redirects; do not send anything 905 * set dst.rate_last to the last seen redirected packet. 906 */ 907 if (peer->n_redirects >= ip_rt_redirect_number) { 908 peer->rate_last = jiffies; 909 goto out_put_peer; 910 } 911 912 /* Check for load limit; set rate_last to the latest sent 913 * redirect. 914 */ 915 if (peer->rate_tokens == 0 || 916 time_after(jiffies, 917 (peer->rate_last + 918 (ip_rt_redirect_load << peer->rate_tokens)))) { 919 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr); 920 921 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw); 922 peer->rate_last = jiffies; 923 ++peer->rate_tokens; 924 ++peer->n_redirects; 925 #ifdef CONFIG_IP_ROUTE_VERBOSE 926 if (log_martians && 927 peer->rate_tokens == ip_rt_redirect_number) 928 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n", 929 &ip_hdr(skb)->saddr, inet_iif(skb), 930 &ip_hdr(skb)->daddr, &gw); 931 #endif 932 } 933 out_put_peer: 934 inet_putpeer(peer); 935 } 936 937 static int ip_error(struct sk_buff *skb) 938 { 939 struct rtable *rt = skb_rtable(skb); 940 struct net_device *dev = skb->dev; 941 struct in_device *in_dev; 942 struct inet_peer *peer; 943 unsigned long now; 944 struct net *net; 945 bool send; 946 int code; 947 948 if (netif_is_l3_master(skb->dev)) { 949 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 950 if (!dev) 951 goto out; 952 } 953 954 in_dev = __in_dev_get_rcu(dev); 955 956 /* IP on this device is disabled. */ 957 if (!in_dev) 958 goto out; 959 960 net = dev_net(rt->dst.dev); 961 if (!IN_DEV_FORWARD(in_dev)) { 962 switch (rt->dst.error) { 963 case EHOSTUNREACH: 964 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS); 965 break; 966 967 case ENETUNREACH: 968 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 969 break; 970 } 971 goto out; 972 } 973 974 switch (rt->dst.error) { 975 case EINVAL: 976 default: 977 goto out; 978 case EHOSTUNREACH: 979 code = ICMP_HOST_UNREACH; 980 break; 981 case ENETUNREACH: 982 code = ICMP_NET_UNREACH; 983 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES); 984 break; 985 case EACCES: 986 code = ICMP_PKT_FILTERED; 987 break; 988 } 989 990 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 991 l3mdev_master_ifindex(skb->dev), 1); 992 993 send = true; 994 if (peer) { 995 now = jiffies; 996 peer->rate_tokens += now - peer->rate_last; 997 if (peer->rate_tokens > ip_rt_error_burst) 998 peer->rate_tokens = ip_rt_error_burst; 999 peer->rate_last = now; 1000 if (peer->rate_tokens >= ip_rt_error_cost) 1001 peer->rate_tokens -= ip_rt_error_cost; 1002 else 1003 send = false; 1004 inet_putpeer(peer); 1005 } 1006 if (send) 1007 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1008 1009 out: kfree_skb(skb); 1010 return 0; 1011 } 1012 1013 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) 1014 { 1015 struct dst_entry *dst = &rt->dst; 1016 u32 old_mtu = ipv4_mtu(dst); 1017 struct fib_result res; 1018 bool lock = false; 1019 1020 if (ip_mtu_locked(dst)) 1021 return; 1022 1023 if (old_mtu < mtu) 1024 return; 1025 1026 if (mtu < ip_rt_min_pmtu) { 1027 lock = true; 1028 mtu = min(old_mtu, ip_rt_min_pmtu); 1029 } 1030 1031 if (rt->rt_pmtu == mtu && !lock && 1032 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2)) 1033 return; 1034 1035 rcu_read_lock(); 1036 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) { 1037 struct fib_nh_common *nhc = FIB_RES_NHC(res); 1038 1039 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock, 1040 jiffies + ip_rt_mtu_expires); 1041 } 1042 rcu_read_unlock(); 1043 } 1044 1045 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1046 struct sk_buff *skb, u32 mtu) 1047 { 1048 struct rtable *rt = (struct rtable *) dst; 1049 struct flowi4 fl4; 1050 1051 ip_rt_build_flow_key(&fl4, sk, skb); 1052 __ip_rt_update_pmtu(rt, &fl4, mtu); 1053 } 1054 1055 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 1056 int oif, u8 protocol) 1057 { 1058 const struct iphdr *iph = (const struct iphdr *) skb->data; 1059 struct flowi4 fl4; 1060 struct rtable *rt; 1061 u32 mark = IP4_REPLY_MARK(net, skb->mark); 1062 1063 __build_flow_key(net, &fl4, NULL, iph, oif, 1064 RT_TOS(iph->tos), protocol, mark, 0); 1065 rt = __ip_route_output_key(net, &fl4); 1066 if (!IS_ERR(rt)) { 1067 __ip_rt_update_pmtu(rt, &fl4, mtu); 1068 ip_rt_put(rt); 1069 } 1070 } 1071 EXPORT_SYMBOL_GPL(ipv4_update_pmtu); 1072 1073 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1074 { 1075 const struct iphdr *iph = (const struct iphdr *) skb->data; 1076 struct flowi4 fl4; 1077 struct rtable *rt; 1078 1079 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0); 1080 1081 if (!fl4.flowi4_mark) 1082 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark); 1083 1084 rt = __ip_route_output_key(sock_net(sk), &fl4); 1085 if (!IS_ERR(rt)) { 1086 __ip_rt_update_pmtu(rt, &fl4, mtu); 1087 ip_rt_put(rt); 1088 } 1089 } 1090 1091 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) 1092 { 1093 const struct iphdr *iph = (const struct iphdr *) skb->data; 1094 struct flowi4 fl4; 1095 struct rtable *rt; 1096 struct dst_entry *odst = NULL; 1097 bool new = false; 1098 struct net *net = sock_net(sk); 1099 1100 bh_lock_sock(sk); 1101 1102 if (!ip_sk_accept_pmtu(sk)) 1103 goto out; 1104 1105 odst = sk_dst_get(sk); 1106 1107 if (sock_owned_by_user(sk) || !odst) { 1108 __ipv4_sk_update_pmtu(skb, sk, mtu); 1109 goto out; 1110 } 1111 1112 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1113 1114 rt = (struct rtable *)odst; 1115 if (odst->obsolete && !odst->ops->check(odst, 0)) { 1116 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1117 if (IS_ERR(rt)) 1118 goto out; 1119 1120 new = true; 1121 } 1122 1123 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu); 1124 1125 if (!dst_check(&rt->dst, 0)) { 1126 if (new) 1127 dst_release(&rt->dst); 1128 1129 rt = ip_route_output_flow(sock_net(sk), &fl4, sk); 1130 if (IS_ERR(rt)) 1131 goto out; 1132 1133 new = true; 1134 } 1135 1136 if (new) 1137 sk_dst_set(sk, &rt->dst); 1138 1139 out: 1140 bh_unlock_sock(sk); 1141 dst_release(odst); 1142 } 1143 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); 1144 1145 void ipv4_redirect(struct sk_buff *skb, struct net *net, 1146 int oif, u8 protocol) 1147 { 1148 const struct iphdr *iph = (const struct iphdr *) skb->data; 1149 struct flowi4 fl4; 1150 struct rtable *rt; 1151 1152 __build_flow_key(net, &fl4, NULL, iph, oif, 1153 RT_TOS(iph->tos), protocol, 0, 0); 1154 rt = __ip_route_output_key(net, &fl4); 1155 if (!IS_ERR(rt)) { 1156 __ip_do_redirect(rt, skb, &fl4, false); 1157 ip_rt_put(rt); 1158 } 1159 } 1160 EXPORT_SYMBOL_GPL(ipv4_redirect); 1161 1162 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk) 1163 { 1164 const struct iphdr *iph = (const struct iphdr *) skb->data; 1165 struct flowi4 fl4; 1166 struct rtable *rt; 1167 struct net *net = sock_net(sk); 1168 1169 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0); 1170 rt = __ip_route_output_key(net, &fl4); 1171 if (!IS_ERR(rt)) { 1172 __ip_do_redirect(rt, skb, &fl4, false); 1173 ip_rt_put(rt); 1174 } 1175 } 1176 EXPORT_SYMBOL_GPL(ipv4_sk_redirect); 1177 1178 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1179 { 1180 struct rtable *rt = (struct rtable *) dst; 1181 1182 /* All IPV4 dsts are created with ->obsolete set to the value 1183 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1184 * into this function always. 1185 * 1186 * When a PMTU/redirect information update invalidates a route, 1187 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or 1188 * DST_OBSOLETE_DEAD. 1189 */ 1190 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt)) 1191 return NULL; 1192 return dst; 1193 } 1194 1195 static void ipv4_send_dest_unreach(struct sk_buff *skb) 1196 { 1197 struct ip_options opt; 1198 int res; 1199 1200 /* Recompile ip options since IPCB may not be valid anymore. 1201 * Also check we have a reasonable ipv4 header. 1202 */ 1203 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) || 1204 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5) 1205 return; 1206 1207 memset(&opt, 0, sizeof(opt)); 1208 if (ip_hdr(skb)->ihl > 5) { 1209 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4)) 1210 return; 1211 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr); 1212 1213 rcu_read_lock(); 1214 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL); 1215 rcu_read_unlock(); 1216 1217 if (res) 1218 return; 1219 } 1220 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt); 1221 } 1222 1223 static void ipv4_link_failure(struct sk_buff *skb) 1224 { 1225 struct rtable *rt; 1226 1227 ipv4_send_dest_unreach(skb); 1228 1229 rt = skb_rtable(skb); 1230 if (rt) 1231 dst_set_expires(&rt->dst, 0); 1232 } 1233 1234 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb) 1235 { 1236 pr_debug("%s: %pI4 -> %pI4, %s\n", 1237 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1238 skb->dev ? skb->dev->name : "?"); 1239 kfree_skb(skb); 1240 WARN_ON(1); 1241 return 0; 1242 } 1243 1244 /* 1245 We do not cache source address of outgoing interface, 1246 because it is used only by IP RR, TS and SRR options, 1247 so that it out of fast path. 1248 1249 BTW remember: "addr" is allowed to be not aligned 1250 in IP options! 1251 */ 1252 1253 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1254 { 1255 __be32 src; 1256 1257 if (rt_is_output_route(rt)) 1258 src = ip_hdr(skb)->saddr; 1259 else { 1260 struct fib_result res; 1261 struct iphdr *iph = ip_hdr(skb); 1262 struct flowi4 fl4 = { 1263 .daddr = iph->daddr, 1264 .saddr = iph->saddr, 1265 .flowi4_tos = RT_TOS(iph->tos), 1266 .flowi4_oif = rt->dst.dev->ifindex, 1267 .flowi4_iif = skb->dev->ifindex, 1268 .flowi4_mark = skb->mark, 1269 }; 1270 1271 rcu_read_lock(); 1272 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0) 1273 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res); 1274 else 1275 src = inet_select_addr(rt->dst.dev, 1276 rt_nexthop(rt, iph->daddr), 1277 RT_SCOPE_UNIVERSE); 1278 rcu_read_unlock(); 1279 } 1280 memcpy(addr, &src, 4); 1281 } 1282 1283 #ifdef CONFIG_IP_ROUTE_CLASSID 1284 static void set_class_tag(struct rtable *rt, u32 tag) 1285 { 1286 if (!(rt->dst.tclassid & 0xFFFF)) 1287 rt->dst.tclassid |= tag & 0xFFFF; 1288 if (!(rt->dst.tclassid & 0xFFFF0000)) 1289 rt->dst.tclassid |= tag & 0xFFFF0000; 1290 } 1291 #endif 1292 1293 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1294 { 1295 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); 1296 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, 1297 ip_rt_min_advmss); 1298 1299 return min(advmss, IPV4_MAX_PMTU - header_size); 1300 } 1301 1302 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1303 { 1304 const struct rtable *rt = (const struct rtable *) dst; 1305 unsigned int mtu = rt->rt_pmtu; 1306 1307 if (!mtu || time_after_eq(jiffies, rt->dst.expires)) 1308 mtu = dst_metric_raw(dst, RTAX_MTU); 1309 1310 if (mtu) 1311 return mtu; 1312 1313 mtu = READ_ONCE(dst->dev->mtu); 1314 1315 if (unlikely(ip_mtu_locked(dst))) { 1316 if (rt->rt_gw_family && mtu > 576) 1317 mtu = 576; 1318 } 1319 1320 mtu = min_t(unsigned int, mtu, IP_MAX_MTU); 1321 1322 return mtu - lwtunnel_headroom(dst->lwtstate, mtu); 1323 } 1324 1325 static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr) 1326 { 1327 struct fnhe_hash_bucket *hash; 1328 struct fib_nh_exception *fnhe, __rcu **fnhe_p; 1329 u32 hval = fnhe_hashfun(daddr); 1330 1331 spin_lock_bh(&fnhe_lock); 1332 1333 hash = rcu_dereference_protected(nhc->nhc_exceptions, 1334 lockdep_is_held(&fnhe_lock)); 1335 hash += hval; 1336 1337 fnhe_p = &hash->chain; 1338 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock)); 1339 while (fnhe) { 1340 if (fnhe->fnhe_daddr == daddr) { 1341 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected( 1342 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock))); 1343 /* set fnhe_daddr to 0 to ensure it won't bind with 1344 * new dsts in rt_bind_exception(). 1345 */ 1346 fnhe->fnhe_daddr = 0; 1347 fnhe_flush_routes(fnhe); 1348 kfree_rcu(fnhe, rcu); 1349 break; 1350 } 1351 fnhe_p = &fnhe->fnhe_next; 1352 fnhe = rcu_dereference_protected(fnhe->fnhe_next, 1353 lockdep_is_held(&fnhe_lock)); 1354 } 1355 1356 spin_unlock_bh(&fnhe_lock); 1357 } 1358 1359 static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc, 1360 __be32 daddr) 1361 { 1362 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions); 1363 struct fib_nh_exception *fnhe; 1364 u32 hval; 1365 1366 if (!hash) 1367 return NULL; 1368 1369 hval = fnhe_hashfun(daddr); 1370 1371 for (fnhe = rcu_dereference(hash[hval].chain); fnhe; 1372 fnhe = rcu_dereference(fnhe->fnhe_next)) { 1373 if (fnhe->fnhe_daddr == daddr) { 1374 if (fnhe->fnhe_expires && 1375 time_after(jiffies, fnhe->fnhe_expires)) { 1376 ip_del_fnhe(nhc, daddr); 1377 break; 1378 } 1379 return fnhe; 1380 } 1381 } 1382 return NULL; 1383 } 1384 1385 /* MTU selection: 1386 * 1. mtu on route is locked - use it 1387 * 2. mtu from nexthop exception 1388 * 3. mtu from egress device 1389 */ 1390 1391 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr) 1392 { 1393 struct fib_nh_common *nhc = res->nhc; 1394 struct net_device *dev = nhc->nhc_dev; 1395 struct fib_info *fi = res->fi; 1396 u32 mtu = 0; 1397 1398 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu || 1399 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU)) 1400 mtu = fi->fib_mtu; 1401 1402 if (likely(!mtu)) { 1403 struct fib_nh_exception *fnhe; 1404 1405 fnhe = find_exception(nhc, daddr); 1406 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires)) 1407 mtu = fnhe->fnhe_pmtu; 1408 } 1409 1410 if (likely(!mtu)) 1411 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU); 1412 1413 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu); 1414 } 1415 1416 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, 1417 __be32 daddr, const bool do_cache) 1418 { 1419 bool ret = false; 1420 1421 spin_lock_bh(&fnhe_lock); 1422 1423 if (daddr == fnhe->fnhe_daddr) { 1424 struct rtable __rcu **porig; 1425 struct rtable *orig; 1426 int genid = fnhe_genid(dev_net(rt->dst.dev)); 1427 1428 if (rt_is_input_route(rt)) 1429 porig = &fnhe->fnhe_rth_input; 1430 else 1431 porig = &fnhe->fnhe_rth_output; 1432 orig = rcu_dereference(*porig); 1433 1434 if (fnhe->fnhe_genid != genid) { 1435 fnhe->fnhe_genid = genid; 1436 fnhe->fnhe_gw = 0; 1437 fnhe->fnhe_pmtu = 0; 1438 fnhe->fnhe_expires = 0; 1439 fnhe->fnhe_mtu_locked = false; 1440 fnhe_flush_routes(fnhe); 1441 orig = NULL; 1442 } 1443 fill_route_from_fnhe(rt, fnhe); 1444 if (!rt->rt_gw4) { 1445 rt->rt_gw4 = daddr; 1446 rt->rt_gw_family = AF_INET; 1447 } 1448 1449 if (do_cache) { 1450 dst_hold(&rt->dst); 1451 rcu_assign_pointer(*porig, rt); 1452 if (orig) { 1453 dst_dev_put(&orig->dst); 1454 dst_release(&orig->dst); 1455 } 1456 ret = true; 1457 } 1458 1459 fnhe->fnhe_stamp = jiffies; 1460 } 1461 spin_unlock_bh(&fnhe_lock); 1462 1463 return ret; 1464 } 1465 1466 static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 1467 { 1468 struct rtable *orig, *prev, **p; 1469 bool ret = true; 1470 1471 if (rt_is_input_route(rt)) { 1472 p = (struct rtable **)&nhc->nhc_rth_input; 1473 } else { 1474 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 1475 } 1476 orig = *p; 1477 1478 /* hold dst before doing cmpxchg() to avoid race condition 1479 * on this dst 1480 */ 1481 dst_hold(&rt->dst); 1482 prev = cmpxchg(p, orig, rt); 1483 if (prev == orig) { 1484 if (orig) { 1485 dst_dev_put(&orig->dst); 1486 dst_release(&orig->dst); 1487 } 1488 } else { 1489 dst_release(&rt->dst); 1490 ret = false; 1491 } 1492 1493 return ret; 1494 } 1495 1496 struct uncached_list { 1497 spinlock_t lock; 1498 struct list_head head; 1499 }; 1500 1501 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list); 1502 1503 void rt_add_uncached_list(struct rtable *rt) 1504 { 1505 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list); 1506 1507 rt->rt_uncached_list = ul; 1508 1509 spin_lock_bh(&ul->lock); 1510 list_add_tail(&rt->rt_uncached, &ul->head); 1511 spin_unlock_bh(&ul->lock); 1512 } 1513 1514 void rt_del_uncached_list(struct rtable *rt) 1515 { 1516 if (!list_empty(&rt->rt_uncached)) { 1517 struct uncached_list *ul = rt->rt_uncached_list; 1518 1519 spin_lock_bh(&ul->lock); 1520 list_del(&rt->rt_uncached); 1521 spin_unlock_bh(&ul->lock); 1522 } 1523 } 1524 1525 static void ipv4_dst_destroy(struct dst_entry *dst) 1526 { 1527 struct rtable *rt = (struct rtable *)dst; 1528 1529 ip_dst_metrics_put(dst); 1530 rt_del_uncached_list(rt); 1531 } 1532 1533 void rt_flush_dev(struct net_device *dev) 1534 { 1535 struct net *net = dev_net(dev); 1536 struct rtable *rt; 1537 int cpu; 1538 1539 for_each_possible_cpu(cpu) { 1540 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 1541 1542 spin_lock_bh(&ul->lock); 1543 list_for_each_entry(rt, &ul->head, rt_uncached) { 1544 if (rt->dst.dev != dev) 1545 continue; 1546 rt->dst.dev = net->loopback_dev; 1547 dev_hold(rt->dst.dev); 1548 dev_put(dev); 1549 } 1550 spin_unlock_bh(&ul->lock); 1551 } 1552 } 1553 1554 static bool rt_cache_valid(const struct rtable *rt) 1555 { 1556 return rt && 1557 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1558 !rt_is_expired(rt); 1559 } 1560 1561 static void rt_set_nexthop(struct rtable *rt, __be32 daddr, 1562 const struct fib_result *res, 1563 struct fib_nh_exception *fnhe, 1564 struct fib_info *fi, u16 type, u32 itag, 1565 const bool do_cache) 1566 { 1567 bool cached = false; 1568 1569 if (fi) { 1570 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1571 1572 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) { 1573 rt->rt_gw_family = nhc->nhc_gw_family; 1574 /* only INET and INET6 are supported */ 1575 if (likely(nhc->nhc_gw_family == AF_INET)) 1576 rt->rt_gw4 = nhc->nhc_gw.ipv4; 1577 else 1578 rt->rt_gw6 = nhc->nhc_gw.ipv6; 1579 } 1580 1581 ip_dst_init_metrics(&rt->dst, fi->fib_metrics); 1582 1583 #ifdef CONFIG_IP_ROUTE_CLASSID 1584 if (nhc->nhc_family == AF_INET) { 1585 struct fib_nh *nh; 1586 1587 nh = container_of(nhc, struct fib_nh, nh_common); 1588 rt->dst.tclassid = nh->nh_tclassid; 1589 } 1590 #endif 1591 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 1592 if (unlikely(fnhe)) 1593 cached = rt_bind_exception(rt, fnhe, daddr, do_cache); 1594 else if (do_cache) 1595 cached = rt_cache_route(nhc, rt); 1596 if (unlikely(!cached)) { 1597 /* Routes we intend to cache in nexthop exception or 1598 * FIB nexthop have the DST_NOCACHE bit clear. 1599 * However, if we are unsuccessful at storing this 1600 * route into the cache we really need to set it. 1601 */ 1602 if (!rt->rt_gw4) { 1603 rt->rt_gw_family = AF_INET; 1604 rt->rt_gw4 = daddr; 1605 } 1606 rt_add_uncached_list(rt); 1607 } 1608 } else 1609 rt_add_uncached_list(rt); 1610 1611 #ifdef CONFIG_IP_ROUTE_CLASSID 1612 #ifdef CONFIG_IP_MULTIPLE_TABLES 1613 set_class_tag(rt, res->tclassid); 1614 #endif 1615 set_class_tag(rt, itag); 1616 #endif 1617 } 1618 1619 struct rtable *rt_dst_alloc(struct net_device *dev, 1620 unsigned int flags, u16 type, 1621 bool nopolicy, bool noxfrm, bool will_cache) 1622 { 1623 struct rtable *rt; 1624 1625 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, 1626 (will_cache ? 0 : DST_HOST) | 1627 (nopolicy ? DST_NOPOLICY : 0) | 1628 (noxfrm ? DST_NOXFRM : 0)); 1629 1630 if (rt) { 1631 rt->rt_genid = rt_genid_ipv4(dev_net(dev)); 1632 rt->rt_flags = flags; 1633 rt->rt_type = type; 1634 rt->rt_is_input = 0; 1635 rt->rt_iif = 0; 1636 rt->rt_pmtu = 0; 1637 rt->rt_mtu_locked = 0; 1638 rt->rt_gw_family = 0; 1639 rt->rt_gw4 = 0; 1640 INIT_LIST_HEAD(&rt->rt_uncached); 1641 1642 rt->dst.output = ip_output; 1643 if (flags & RTCF_LOCAL) 1644 rt->dst.input = ip_local_deliver; 1645 } 1646 1647 return rt; 1648 } 1649 EXPORT_SYMBOL(rt_dst_alloc); 1650 1651 /* called in rcu_read_lock() section */ 1652 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1653 u8 tos, struct net_device *dev, 1654 struct in_device *in_dev, u32 *itag) 1655 { 1656 int err; 1657 1658 /* Primary sanity checks. */ 1659 if (!in_dev) 1660 return -EINVAL; 1661 1662 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1663 skb->protocol != htons(ETH_P_IP)) 1664 return -EINVAL; 1665 1666 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) 1667 return -EINVAL; 1668 1669 if (ipv4_is_zeronet(saddr)) { 1670 if (!ipv4_is_local_multicast(daddr) && 1671 ip_hdr(skb)->protocol != IPPROTO_IGMP) 1672 return -EINVAL; 1673 } else { 1674 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 1675 in_dev, itag); 1676 if (err < 0) 1677 return err; 1678 } 1679 return 0; 1680 } 1681 1682 /* called in rcu_read_lock() section */ 1683 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1684 u8 tos, struct net_device *dev, int our) 1685 { 1686 struct in_device *in_dev = __in_dev_get_rcu(dev); 1687 unsigned int flags = RTCF_MULTICAST; 1688 struct rtable *rth; 1689 u32 itag = 0; 1690 int err; 1691 1692 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag); 1693 if (err) 1694 return err; 1695 1696 if (our) 1697 flags |= RTCF_LOCAL; 1698 1699 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST, 1700 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false); 1701 if (!rth) 1702 return -ENOBUFS; 1703 1704 #ifdef CONFIG_IP_ROUTE_CLASSID 1705 rth->dst.tclassid = itag; 1706 #endif 1707 rth->dst.output = ip_rt_bug; 1708 rth->rt_is_input= 1; 1709 1710 #ifdef CONFIG_IP_MROUTE 1711 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1712 rth->dst.input = ip_mr_input; 1713 #endif 1714 RT_CACHE_STAT_INC(in_slow_mc); 1715 1716 skb_dst_set(skb, &rth->dst); 1717 return 0; 1718 } 1719 1720 1721 static void ip_handle_martian_source(struct net_device *dev, 1722 struct in_device *in_dev, 1723 struct sk_buff *skb, 1724 __be32 daddr, 1725 __be32 saddr) 1726 { 1727 RT_CACHE_STAT_INC(in_martian_src); 1728 #ifdef CONFIG_IP_ROUTE_VERBOSE 1729 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1730 /* 1731 * RFC1812 recommendation, if source is martian, 1732 * the only hint is MAC header. 1733 */ 1734 pr_warn("martian source %pI4 from %pI4, on dev %s\n", 1735 &daddr, &saddr, dev->name); 1736 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1737 print_hex_dump(KERN_WARNING, "ll header: ", 1738 DUMP_PREFIX_OFFSET, 16, 1, 1739 skb_mac_header(skb), 1740 dev->hard_header_len, false); 1741 } 1742 } 1743 #endif 1744 } 1745 1746 /* called in rcu_read_lock() section */ 1747 static int __mkroute_input(struct sk_buff *skb, 1748 const struct fib_result *res, 1749 struct in_device *in_dev, 1750 __be32 daddr, __be32 saddr, u32 tos) 1751 { 1752 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 1753 struct net_device *dev = nhc->nhc_dev; 1754 struct fib_nh_exception *fnhe; 1755 struct rtable *rth; 1756 int err; 1757 struct in_device *out_dev; 1758 bool do_cache; 1759 u32 itag = 0; 1760 1761 /* get a working reference to the output device */ 1762 out_dev = __in_dev_get_rcu(dev); 1763 if (!out_dev) { 1764 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n"); 1765 return -EINVAL; 1766 } 1767 1768 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1769 in_dev->dev, in_dev, &itag); 1770 if (err < 0) { 1771 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1772 saddr); 1773 1774 goto cleanup; 1775 } 1776 1777 do_cache = res->fi && !itag; 1778 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) && 1779 skb->protocol == htons(ETH_P_IP)) { 1780 __be32 gw; 1781 1782 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0; 1783 if (IN_DEV_SHARED_MEDIA(out_dev) || 1784 inet_addr_onlink(out_dev, saddr, gw)) 1785 IPCB(skb)->flags |= IPSKB_DOREDIRECT; 1786 } 1787 1788 if (skb->protocol != htons(ETH_P_IP)) { 1789 /* Not IP (i.e. ARP). Do not create route, if it is 1790 * invalid for proxy arp. DNAT routes are always valid. 1791 * 1792 * Proxy arp feature have been extended to allow, ARP 1793 * replies back to the same interface, to support 1794 * Private VLAN switch technologies. See arp.c. 1795 */ 1796 if (out_dev == in_dev && 1797 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1798 err = -EINVAL; 1799 goto cleanup; 1800 } 1801 } 1802 1803 fnhe = find_exception(nhc, daddr); 1804 if (do_cache) { 1805 if (fnhe) 1806 rth = rcu_dereference(fnhe->fnhe_rth_input); 1807 else 1808 rth = rcu_dereference(nhc->nhc_rth_input); 1809 if (rt_cache_valid(rth)) { 1810 skb_dst_set_noref(skb, &rth->dst); 1811 goto out; 1812 } 1813 } 1814 1815 rth = rt_dst_alloc(out_dev->dev, 0, res->type, 1816 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1817 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache); 1818 if (!rth) { 1819 err = -ENOBUFS; 1820 goto cleanup; 1821 } 1822 1823 rth->rt_is_input = 1; 1824 RT_CACHE_STAT_INC(in_slow_tot); 1825 1826 rth->dst.input = ip_forward; 1827 1828 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag, 1829 do_cache); 1830 lwtunnel_set_redirect(&rth->dst); 1831 skb_dst_set(skb, &rth->dst); 1832 out: 1833 err = 0; 1834 cleanup: 1835 return err; 1836 } 1837 1838 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1839 /* To make ICMP packets follow the right flow, the multipath hash is 1840 * calculated from the inner IP addresses. 1841 */ 1842 static void ip_multipath_l3_keys(const struct sk_buff *skb, 1843 struct flow_keys *hash_keys) 1844 { 1845 const struct iphdr *outer_iph = ip_hdr(skb); 1846 const struct iphdr *key_iph = outer_iph; 1847 const struct iphdr *inner_iph; 1848 const struct icmphdr *icmph; 1849 struct iphdr _inner_iph; 1850 struct icmphdr _icmph; 1851 1852 if (likely(outer_iph->protocol != IPPROTO_ICMP)) 1853 goto out; 1854 1855 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0)) 1856 goto out; 1857 1858 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph), 1859 &_icmph); 1860 if (!icmph) 1861 goto out; 1862 1863 if (icmph->type != ICMP_DEST_UNREACH && 1864 icmph->type != ICMP_REDIRECT && 1865 icmph->type != ICMP_TIME_EXCEEDED && 1866 icmph->type != ICMP_PARAMETERPROB) 1867 goto out; 1868 1869 inner_iph = skb_header_pointer(skb, 1870 outer_iph->ihl * 4 + sizeof(_icmph), 1871 sizeof(_inner_iph), &_inner_iph); 1872 if (!inner_iph) 1873 goto out; 1874 1875 key_iph = inner_iph; 1876 out: 1877 hash_keys->addrs.v4addrs.src = key_iph->saddr; 1878 hash_keys->addrs.v4addrs.dst = key_iph->daddr; 1879 } 1880 1881 /* if skb is set it will be used and fl4 can be NULL */ 1882 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 1883 const struct sk_buff *skb, struct flow_keys *flkeys) 1884 { 1885 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0; 1886 struct flow_keys hash_keys; 1887 u32 mhash; 1888 1889 switch (net->ipv4.sysctl_fib_multipath_hash_policy) { 1890 case 0: 1891 memset(&hash_keys, 0, sizeof(hash_keys)); 1892 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1893 if (skb) { 1894 ip_multipath_l3_keys(skb, &hash_keys); 1895 } else { 1896 hash_keys.addrs.v4addrs.src = fl4->saddr; 1897 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1898 } 1899 break; 1900 case 1: 1901 /* skb is currently provided only when forwarding */ 1902 if (skb) { 1903 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 1904 struct flow_keys keys; 1905 1906 /* short-circuit if we already have L4 hash present */ 1907 if (skb->l4_hash) 1908 return skb_get_hash_raw(skb) >> 1; 1909 1910 memset(&hash_keys, 0, sizeof(hash_keys)); 1911 1912 if (!flkeys) { 1913 skb_flow_dissect_flow_keys(skb, &keys, flag); 1914 flkeys = &keys; 1915 } 1916 1917 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1918 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 1919 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 1920 hash_keys.ports.src = flkeys->ports.src; 1921 hash_keys.ports.dst = flkeys->ports.dst; 1922 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 1923 } else { 1924 memset(&hash_keys, 0, sizeof(hash_keys)); 1925 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1926 hash_keys.addrs.v4addrs.src = fl4->saddr; 1927 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1928 hash_keys.ports.src = fl4->fl4_sport; 1929 hash_keys.ports.dst = fl4->fl4_dport; 1930 hash_keys.basic.ip_proto = fl4->flowi4_proto; 1931 } 1932 break; 1933 case 2: 1934 memset(&hash_keys, 0, sizeof(hash_keys)); 1935 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1936 /* skb is currently provided only when forwarding */ 1937 if (skb) { 1938 struct flow_keys keys; 1939 1940 skb_flow_dissect_flow_keys(skb, &keys, 0); 1941 1942 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 1943 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 1944 } else { 1945 /* Same as case 0 */ 1946 hash_keys.addrs.v4addrs.src = fl4->saddr; 1947 hash_keys.addrs.v4addrs.dst = fl4->daddr; 1948 } 1949 break; 1950 } 1951 mhash = flow_hash_from_keys(&hash_keys); 1952 1953 if (multipath_hash) 1954 mhash = jhash_2words(mhash, multipath_hash, 0); 1955 1956 return mhash >> 1; 1957 } 1958 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1959 1960 static int ip_mkroute_input(struct sk_buff *skb, 1961 struct fib_result *res, 1962 struct in_device *in_dev, 1963 __be32 daddr, __be32 saddr, u32 tos, 1964 struct flow_keys *hkeys) 1965 { 1966 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1967 if (res->fi && fib_info_num_path(res->fi) > 1) { 1968 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1969 1970 fib_select_multipath(res, h); 1971 } 1972 #endif 1973 1974 /* create a routing cache entry */ 1975 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1976 } 1977 1978 /* 1979 * NOTE. We drop all the packets that has local source 1980 * addresses, because every properly looped back packet 1981 * must have correct destination already attached by output routine. 1982 * 1983 * Such approach solves two big problems: 1984 * 1. Not simplex devices are handled properly. 1985 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1986 * called with rcu_read_lock() 1987 */ 1988 1989 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1990 u8 tos, struct net_device *dev, 1991 struct fib_result *res) 1992 { 1993 struct in_device *in_dev = __in_dev_get_rcu(dev); 1994 struct flow_keys *flkeys = NULL, _flkeys; 1995 struct net *net = dev_net(dev); 1996 struct ip_tunnel_info *tun_info; 1997 int err = -EINVAL; 1998 unsigned int flags = 0; 1999 u32 itag = 0; 2000 struct rtable *rth; 2001 struct flowi4 fl4; 2002 bool do_cache = true; 2003 2004 /* IP on this device is disabled. */ 2005 2006 if (!in_dev) 2007 goto out; 2008 2009 /* Check for the most weird martians, which can be not detected 2010 by fib_lookup. 2011 */ 2012 2013 tun_info = skb_tunnel_info(skb); 2014 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2015 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 2016 else 2017 fl4.flowi4_tun_key.tun_id = 0; 2018 skb_dst_drop(skb); 2019 2020 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2021 goto martian_source; 2022 2023 res->fi = NULL; 2024 res->table = NULL; 2025 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2026 goto brd_input; 2027 2028 /* Accept zero addresses only to limited broadcast; 2029 * I even do not know to fix it or not. Waiting for complains :-) 2030 */ 2031 if (ipv4_is_zeronet(saddr)) 2032 goto martian_source; 2033 2034 if (ipv4_is_zeronet(daddr)) 2035 goto martian_destination; 2036 2037 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2038 * and call it once if daddr or/and saddr are loopback addresses 2039 */ 2040 if (ipv4_is_loopback(daddr)) { 2041 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2042 goto martian_destination; 2043 } else if (ipv4_is_loopback(saddr)) { 2044 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2045 goto martian_source; 2046 } 2047 2048 /* 2049 * Now we are ready to route packet. 2050 */ 2051 fl4.flowi4_oif = 0; 2052 fl4.flowi4_iif = dev->ifindex; 2053 fl4.flowi4_mark = skb->mark; 2054 fl4.flowi4_tos = tos; 2055 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2056 fl4.flowi4_flags = 0; 2057 fl4.daddr = daddr; 2058 fl4.saddr = saddr; 2059 fl4.flowi4_uid = sock_net_uid(net, NULL); 2060 2061 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2062 flkeys = &_flkeys; 2063 } else { 2064 fl4.flowi4_proto = 0; 2065 fl4.fl4_sport = 0; 2066 fl4.fl4_dport = 0; 2067 } 2068 2069 err = fib_lookup(net, &fl4, res, 0); 2070 if (err != 0) { 2071 if (!IN_DEV_FORWARD(in_dev)) 2072 err = -EHOSTUNREACH; 2073 goto no_route; 2074 } 2075 2076 if (res->type == RTN_BROADCAST) { 2077 if (IN_DEV_BFORWARD(in_dev)) 2078 goto make_route; 2079 /* not do cache if bc_forwarding is enabled */ 2080 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2081 do_cache = false; 2082 goto brd_input; 2083 } 2084 2085 if (res->type == RTN_LOCAL) { 2086 err = fib_validate_source(skb, saddr, daddr, tos, 2087 0, dev, in_dev, &itag); 2088 if (err < 0) 2089 goto martian_source; 2090 goto local_input; 2091 } 2092 2093 if (!IN_DEV_FORWARD(in_dev)) { 2094 err = -EHOSTUNREACH; 2095 goto no_route; 2096 } 2097 if (res->type != RTN_UNICAST) 2098 goto martian_destination; 2099 2100 make_route: 2101 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2102 out: return err; 2103 2104 brd_input: 2105 if (skb->protocol != htons(ETH_P_IP)) 2106 goto e_inval; 2107 2108 if (!ipv4_is_zeronet(saddr)) { 2109 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2110 in_dev, &itag); 2111 if (err < 0) 2112 goto martian_source; 2113 } 2114 flags |= RTCF_BROADCAST; 2115 res->type = RTN_BROADCAST; 2116 RT_CACHE_STAT_INC(in_brd); 2117 2118 local_input: 2119 do_cache &= res->fi && !itag; 2120 if (do_cache) { 2121 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2122 2123 rth = rcu_dereference(nhc->nhc_rth_input); 2124 if (rt_cache_valid(rth)) { 2125 skb_dst_set_noref(skb, &rth->dst); 2126 err = 0; 2127 goto out; 2128 } 2129 } 2130 2131 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2132 flags | RTCF_LOCAL, res->type, 2133 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2134 if (!rth) 2135 goto e_nobufs; 2136 2137 rth->dst.output= ip_rt_bug; 2138 #ifdef CONFIG_IP_ROUTE_CLASSID 2139 rth->dst.tclassid = itag; 2140 #endif 2141 rth->rt_is_input = 1; 2142 2143 RT_CACHE_STAT_INC(in_slow_tot); 2144 if (res->type == RTN_UNREACHABLE) { 2145 rth->dst.input= ip_error; 2146 rth->dst.error= -err; 2147 rth->rt_flags &= ~RTCF_LOCAL; 2148 } 2149 2150 if (do_cache) { 2151 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2152 2153 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2154 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2155 WARN_ON(rth->dst.input == lwtunnel_input); 2156 rth->dst.lwtstate->orig_input = rth->dst.input; 2157 rth->dst.input = lwtunnel_input; 2158 } 2159 2160 if (unlikely(!rt_cache_route(nhc, rth))) 2161 rt_add_uncached_list(rth); 2162 } 2163 skb_dst_set(skb, &rth->dst); 2164 err = 0; 2165 goto out; 2166 2167 no_route: 2168 RT_CACHE_STAT_INC(in_no_route); 2169 res->type = RTN_UNREACHABLE; 2170 res->fi = NULL; 2171 res->table = NULL; 2172 goto local_input; 2173 2174 /* 2175 * Do not cache martian addresses: they should be logged (RFC1812) 2176 */ 2177 martian_destination: 2178 RT_CACHE_STAT_INC(in_martian_dst); 2179 #ifdef CONFIG_IP_ROUTE_VERBOSE 2180 if (IN_DEV_LOG_MARTIANS(in_dev)) 2181 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2182 &daddr, &saddr, dev->name); 2183 #endif 2184 2185 e_inval: 2186 err = -EINVAL; 2187 goto out; 2188 2189 e_nobufs: 2190 err = -ENOBUFS; 2191 goto out; 2192 2193 martian_source: 2194 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2195 goto out; 2196 } 2197 2198 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2199 u8 tos, struct net_device *dev) 2200 { 2201 struct fib_result res; 2202 int err; 2203 2204 tos &= IPTOS_RT_MASK; 2205 rcu_read_lock(); 2206 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2207 rcu_read_unlock(); 2208 2209 return err; 2210 } 2211 EXPORT_SYMBOL(ip_route_input_noref); 2212 2213 /* called with rcu_read_lock held */ 2214 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2215 u8 tos, struct net_device *dev, struct fib_result *res) 2216 { 2217 /* Multicast recognition logic is moved from route cache to here. 2218 The problem was that too many Ethernet cards have broken/missing 2219 hardware multicast filters :-( As result the host on multicasting 2220 network acquires a lot of useless route cache entries, sort of 2221 SDR messages from all the world. Now we try to get rid of them. 2222 Really, provided software IP multicast filter is organized 2223 reasonably (at least, hashed), it does not result in a slowdown 2224 comparing with route cache reject entries. 2225 Note, that multicast routers are not affected, because 2226 route cache entry is created eventually. 2227 */ 2228 if (ipv4_is_multicast(daddr)) { 2229 struct in_device *in_dev = __in_dev_get_rcu(dev); 2230 int our = 0; 2231 int err = -EINVAL; 2232 2233 if (!in_dev) 2234 return err; 2235 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2236 ip_hdr(skb)->protocol); 2237 2238 /* check l3 master if no match yet */ 2239 if (!our && netif_is_l3_slave(dev)) { 2240 struct in_device *l3_in_dev; 2241 2242 l3_in_dev = __in_dev_get_rcu(skb->dev); 2243 if (l3_in_dev) 2244 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2245 ip_hdr(skb)->protocol); 2246 } 2247 2248 if (our 2249 #ifdef CONFIG_IP_MROUTE 2250 || 2251 (!ipv4_is_local_multicast(daddr) && 2252 IN_DEV_MFORWARD(in_dev)) 2253 #endif 2254 ) { 2255 err = ip_route_input_mc(skb, daddr, saddr, 2256 tos, dev, our); 2257 } 2258 return err; 2259 } 2260 2261 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2262 } 2263 2264 /* called with rcu_read_lock() */ 2265 static struct rtable *__mkroute_output(const struct fib_result *res, 2266 const struct flowi4 *fl4, int orig_oif, 2267 struct net_device *dev_out, 2268 unsigned int flags) 2269 { 2270 struct fib_info *fi = res->fi; 2271 struct fib_nh_exception *fnhe; 2272 struct in_device *in_dev; 2273 u16 type = res->type; 2274 struct rtable *rth; 2275 bool do_cache; 2276 2277 in_dev = __in_dev_get_rcu(dev_out); 2278 if (!in_dev) 2279 return ERR_PTR(-EINVAL); 2280 2281 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2282 if (ipv4_is_loopback(fl4->saddr) && 2283 !(dev_out->flags & IFF_LOOPBACK) && 2284 !netif_is_l3_master(dev_out)) 2285 return ERR_PTR(-EINVAL); 2286 2287 if (ipv4_is_lbcast(fl4->daddr)) 2288 type = RTN_BROADCAST; 2289 else if (ipv4_is_multicast(fl4->daddr)) 2290 type = RTN_MULTICAST; 2291 else if (ipv4_is_zeronet(fl4->daddr)) 2292 return ERR_PTR(-EINVAL); 2293 2294 if (dev_out->flags & IFF_LOOPBACK) 2295 flags |= RTCF_LOCAL; 2296 2297 do_cache = true; 2298 if (type == RTN_BROADCAST) { 2299 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2300 fi = NULL; 2301 } else if (type == RTN_MULTICAST) { 2302 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2303 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2304 fl4->flowi4_proto)) 2305 flags &= ~RTCF_LOCAL; 2306 else 2307 do_cache = false; 2308 /* If multicast route do not exist use 2309 * default one, but do not gateway in this case. 2310 * Yes, it is hack. 2311 */ 2312 if (fi && res->prefixlen < 4) 2313 fi = NULL; 2314 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2315 (orig_oif != dev_out->ifindex)) { 2316 /* For local routes that require a particular output interface 2317 * we do not want to cache the result. Caching the result 2318 * causes incorrect behaviour when there are multiple source 2319 * addresses on the interface, the end result being that if the 2320 * intended recipient is waiting on that interface for the 2321 * packet he won't receive it because it will be delivered on 2322 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2323 * be set to the loopback interface as well. 2324 */ 2325 do_cache = false; 2326 } 2327 2328 fnhe = NULL; 2329 do_cache &= fi != NULL; 2330 if (fi) { 2331 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2332 struct rtable __rcu **prth; 2333 2334 fnhe = find_exception(nhc, fl4->daddr); 2335 if (!do_cache) 2336 goto add; 2337 if (fnhe) { 2338 prth = &fnhe->fnhe_rth_output; 2339 } else { 2340 if (unlikely(fl4->flowi4_flags & 2341 FLOWI_FLAG_KNOWN_NH && 2342 !(nhc->nhc_gw_family && 2343 nhc->nhc_scope == RT_SCOPE_LINK))) { 2344 do_cache = false; 2345 goto add; 2346 } 2347 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2348 } 2349 rth = rcu_dereference(*prth); 2350 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2351 return rth; 2352 } 2353 2354 add: 2355 rth = rt_dst_alloc(dev_out, flags, type, 2356 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2357 IN_DEV_CONF_GET(in_dev, NOXFRM), 2358 do_cache); 2359 if (!rth) 2360 return ERR_PTR(-ENOBUFS); 2361 2362 rth->rt_iif = orig_oif; 2363 2364 RT_CACHE_STAT_INC(out_slow_tot); 2365 2366 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2367 if (flags & RTCF_LOCAL && 2368 !(dev_out->flags & IFF_LOOPBACK)) { 2369 rth->dst.output = ip_mc_output; 2370 RT_CACHE_STAT_INC(out_slow_mc); 2371 } 2372 #ifdef CONFIG_IP_MROUTE 2373 if (type == RTN_MULTICAST) { 2374 if (IN_DEV_MFORWARD(in_dev) && 2375 !ipv4_is_local_multicast(fl4->daddr)) { 2376 rth->dst.input = ip_mr_input; 2377 rth->dst.output = ip_mc_output; 2378 } 2379 } 2380 #endif 2381 } 2382 2383 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2384 lwtunnel_set_redirect(&rth->dst); 2385 2386 return rth; 2387 } 2388 2389 /* 2390 * Major route resolver routine. 2391 */ 2392 2393 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2394 const struct sk_buff *skb) 2395 { 2396 __u8 tos = RT_FL_TOS(fl4); 2397 struct fib_result res = { 2398 .type = RTN_UNSPEC, 2399 .fi = NULL, 2400 .table = NULL, 2401 .tclassid = 0, 2402 }; 2403 struct rtable *rth; 2404 2405 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2406 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2407 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2408 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2409 2410 rcu_read_lock(); 2411 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2412 rcu_read_unlock(); 2413 2414 return rth; 2415 } 2416 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2417 2418 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2419 struct fib_result *res, 2420 const struct sk_buff *skb) 2421 { 2422 struct net_device *dev_out = NULL; 2423 int orig_oif = fl4->flowi4_oif; 2424 unsigned int flags = 0; 2425 struct rtable *rth; 2426 int err = -ENETUNREACH; 2427 2428 if (fl4->saddr) { 2429 rth = ERR_PTR(-EINVAL); 2430 if (ipv4_is_multicast(fl4->saddr) || 2431 ipv4_is_lbcast(fl4->saddr) || 2432 ipv4_is_zeronet(fl4->saddr)) 2433 goto out; 2434 2435 /* I removed check for oif == dev_out->oif here. 2436 It was wrong for two reasons: 2437 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2438 is assigned to multiple interfaces. 2439 2. Moreover, we are allowed to send packets with saddr 2440 of another iface. --ANK 2441 */ 2442 2443 if (fl4->flowi4_oif == 0 && 2444 (ipv4_is_multicast(fl4->daddr) || 2445 ipv4_is_lbcast(fl4->daddr))) { 2446 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2447 dev_out = __ip_dev_find(net, fl4->saddr, false); 2448 if (!dev_out) 2449 goto out; 2450 2451 /* Special hack: user can direct multicasts 2452 and limited broadcast via necessary interface 2453 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2454 This hack is not just for fun, it allows 2455 vic,vat and friends to work. 2456 They bind socket to loopback, set ttl to zero 2457 and expect that it will work. 2458 From the viewpoint of routing cache they are broken, 2459 because we are not allowed to build multicast path 2460 with loopback source addr (look, routing cache 2461 cannot know, that ttl is zero, so that packet 2462 will not leave this host and route is valid). 2463 Luckily, this hack is good workaround. 2464 */ 2465 2466 fl4->flowi4_oif = dev_out->ifindex; 2467 goto make_route; 2468 } 2469 2470 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2471 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2472 if (!__ip_dev_find(net, fl4->saddr, false)) 2473 goto out; 2474 } 2475 } 2476 2477 2478 if (fl4->flowi4_oif) { 2479 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2480 rth = ERR_PTR(-ENODEV); 2481 if (!dev_out) 2482 goto out; 2483 2484 /* RACE: Check return value of inet_select_addr instead. */ 2485 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2486 rth = ERR_PTR(-ENETUNREACH); 2487 goto out; 2488 } 2489 if (ipv4_is_local_multicast(fl4->daddr) || 2490 ipv4_is_lbcast(fl4->daddr) || 2491 fl4->flowi4_proto == IPPROTO_IGMP) { 2492 if (!fl4->saddr) 2493 fl4->saddr = inet_select_addr(dev_out, 0, 2494 RT_SCOPE_LINK); 2495 goto make_route; 2496 } 2497 if (!fl4->saddr) { 2498 if (ipv4_is_multicast(fl4->daddr)) 2499 fl4->saddr = inet_select_addr(dev_out, 0, 2500 fl4->flowi4_scope); 2501 else if (!fl4->daddr) 2502 fl4->saddr = inet_select_addr(dev_out, 0, 2503 RT_SCOPE_HOST); 2504 } 2505 } 2506 2507 if (!fl4->daddr) { 2508 fl4->daddr = fl4->saddr; 2509 if (!fl4->daddr) 2510 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2511 dev_out = net->loopback_dev; 2512 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2513 res->type = RTN_LOCAL; 2514 flags |= RTCF_LOCAL; 2515 goto make_route; 2516 } 2517 2518 err = fib_lookup(net, fl4, res, 0); 2519 if (err) { 2520 res->fi = NULL; 2521 res->table = NULL; 2522 if (fl4->flowi4_oif && 2523 (ipv4_is_multicast(fl4->daddr) || 2524 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2525 /* Apparently, routing tables are wrong. Assume, 2526 that the destination is on link. 2527 2528 WHY? DW. 2529 Because we are allowed to send to iface 2530 even if it has NO routes and NO assigned 2531 addresses. When oif is specified, routing 2532 tables are looked up with only one purpose: 2533 to catch if destination is gatewayed, rather than 2534 direct. Moreover, if MSG_DONTROUTE is set, 2535 we send packet, ignoring both routing tables 2536 and ifaddr state. --ANK 2537 2538 2539 We could make it even if oif is unknown, 2540 likely IPv6, but we do not. 2541 */ 2542 2543 if (fl4->saddr == 0) 2544 fl4->saddr = inet_select_addr(dev_out, 0, 2545 RT_SCOPE_LINK); 2546 res->type = RTN_UNICAST; 2547 goto make_route; 2548 } 2549 rth = ERR_PTR(err); 2550 goto out; 2551 } 2552 2553 if (res->type == RTN_LOCAL) { 2554 if (!fl4->saddr) { 2555 if (res->fi->fib_prefsrc) 2556 fl4->saddr = res->fi->fib_prefsrc; 2557 else 2558 fl4->saddr = fl4->daddr; 2559 } 2560 2561 /* L3 master device is the loopback for that domain */ 2562 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2563 net->loopback_dev; 2564 2565 /* make sure orig_oif points to fib result device even 2566 * though packet rx/tx happens over loopback or l3mdev 2567 */ 2568 orig_oif = FIB_RES_OIF(*res); 2569 2570 fl4->flowi4_oif = dev_out->ifindex; 2571 flags |= RTCF_LOCAL; 2572 goto make_route; 2573 } 2574 2575 fib_select_path(net, res, fl4, skb); 2576 2577 dev_out = FIB_RES_DEV(*res); 2578 fl4->flowi4_oif = dev_out->ifindex; 2579 2580 2581 make_route: 2582 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2583 2584 out: 2585 return rth; 2586 } 2587 2588 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2589 { 2590 return NULL; 2591 } 2592 2593 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2594 { 2595 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2596 2597 return mtu ? : dst->dev->mtu; 2598 } 2599 2600 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2601 struct sk_buff *skb, u32 mtu) 2602 { 2603 } 2604 2605 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2606 struct sk_buff *skb) 2607 { 2608 } 2609 2610 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2611 unsigned long old) 2612 { 2613 return NULL; 2614 } 2615 2616 static struct dst_ops ipv4_dst_blackhole_ops = { 2617 .family = AF_INET, 2618 .check = ipv4_blackhole_dst_check, 2619 .mtu = ipv4_blackhole_mtu, 2620 .default_advmss = ipv4_default_advmss, 2621 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2622 .redirect = ipv4_rt_blackhole_redirect, 2623 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2624 .neigh_lookup = ipv4_neigh_lookup, 2625 }; 2626 2627 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2628 { 2629 struct rtable *ort = (struct rtable *) dst_orig; 2630 struct rtable *rt; 2631 2632 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2633 if (rt) { 2634 struct dst_entry *new = &rt->dst; 2635 2636 new->__use = 1; 2637 new->input = dst_discard; 2638 new->output = dst_discard_out; 2639 2640 new->dev = net->loopback_dev; 2641 if (new->dev) 2642 dev_hold(new->dev); 2643 2644 rt->rt_is_input = ort->rt_is_input; 2645 rt->rt_iif = ort->rt_iif; 2646 rt->rt_pmtu = ort->rt_pmtu; 2647 rt->rt_mtu_locked = ort->rt_mtu_locked; 2648 2649 rt->rt_genid = rt_genid_ipv4(net); 2650 rt->rt_flags = ort->rt_flags; 2651 rt->rt_type = ort->rt_type; 2652 rt->rt_gw_family = ort->rt_gw_family; 2653 if (rt->rt_gw_family == AF_INET) 2654 rt->rt_gw4 = ort->rt_gw4; 2655 else if (rt->rt_gw_family == AF_INET6) 2656 rt->rt_gw6 = ort->rt_gw6; 2657 2658 INIT_LIST_HEAD(&rt->rt_uncached); 2659 } 2660 2661 dst_release(dst_orig); 2662 2663 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2664 } 2665 2666 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2667 const struct sock *sk) 2668 { 2669 struct rtable *rt = __ip_route_output_key(net, flp4); 2670 2671 if (IS_ERR(rt)) 2672 return rt; 2673 2674 if (flp4->flowi4_proto) 2675 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2676 flowi4_to_flowi(flp4), 2677 sk, 0); 2678 2679 return rt; 2680 } 2681 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2682 2683 /* called with rcu_read_lock held */ 2684 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2685 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2686 struct sk_buff *skb, u32 portid, u32 seq) 2687 { 2688 struct rtmsg *r; 2689 struct nlmsghdr *nlh; 2690 unsigned long expires = 0; 2691 u32 error; 2692 u32 metrics[RTAX_MAX]; 2693 2694 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2695 if (!nlh) 2696 return -EMSGSIZE; 2697 2698 r = nlmsg_data(nlh); 2699 r->rtm_family = AF_INET; 2700 r->rtm_dst_len = 32; 2701 r->rtm_src_len = 0; 2702 r->rtm_tos = fl4->flowi4_tos; 2703 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2704 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2705 goto nla_put_failure; 2706 r->rtm_type = rt->rt_type; 2707 r->rtm_scope = RT_SCOPE_UNIVERSE; 2708 r->rtm_protocol = RTPROT_UNSPEC; 2709 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2710 if (rt->rt_flags & RTCF_NOTIFY) 2711 r->rtm_flags |= RTM_F_NOTIFY; 2712 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2713 r->rtm_flags |= RTCF_DOREDIRECT; 2714 2715 if (nla_put_in_addr(skb, RTA_DST, dst)) 2716 goto nla_put_failure; 2717 if (src) { 2718 r->rtm_src_len = 32; 2719 if (nla_put_in_addr(skb, RTA_SRC, src)) 2720 goto nla_put_failure; 2721 } 2722 if (rt->dst.dev && 2723 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2724 goto nla_put_failure; 2725 #ifdef CONFIG_IP_ROUTE_CLASSID 2726 if (rt->dst.tclassid && 2727 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2728 goto nla_put_failure; 2729 #endif 2730 if (!rt_is_input_route(rt) && 2731 fl4->saddr != src) { 2732 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2733 goto nla_put_failure; 2734 } 2735 if (rt->rt_gw_family == AF_INET && 2736 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2737 goto nla_put_failure; 2738 } else if (rt->rt_gw_family == AF_INET6) { 2739 int alen = sizeof(struct in6_addr); 2740 struct nlattr *nla; 2741 struct rtvia *via; 2742 2743 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2744 if (!nla) 2745 goto nla_put_failure; 2746 2747 via = nla_data(nla); 2748 via->rtvia_family = AF_INET6; 2749 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2750 } 2751 2752 expires = rt->dst.expires; 2753 if (expires) { 2754 unsigned long now = jiffies; 2755 2756 if (time_before(now, expires)) 2757 expires -= now; 2758 else 2759 expires = 0; 2760 } 2761 2762 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2763 if (rt->rt_pmtu && expires) 2764 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2765 if (rt->rt_mtu_locked && expires) 2766 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2767 if (rtnetlink_put_metrics(skb, metrics) < 0) 2768 goto nla_put_failure; 2769 2770 if (fl4->flowi4_mark && 2771 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2772 goto nla_put_failure; 2773 2774 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2775 nla_put_u32(skb, RTA_UID, 2776 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2777 goto nla_put_failure; 2778 2779 error = rt->dst.error; 2780 2781 if (rt_is_input_route(rt)) { 2782 #ifdef CONFIG_IP_MROUTE 2783 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2784 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2785 int err = ipmr_get_route(net, skb, 2786 fl4->saddr, fl4->daddr, 2787 r, portid); 2788 2789 if (err <= 0) { 2790 if (err == 0) 2791 return 0; 2792 goto nla_put_failure; 2793 } 2794 } else 2795 #endif 2796 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2797 goto nla_put_failure; 2798 } 2799 2800 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2801 goto nla_put_failure; 2802 2803 nlmsg_end(skb, nlh); 2804 return 0; 2805 2806 nla_put_failure: 2807 nlmsg_cancel(skb, nlh); 2808 return -EMSGSIZE; 2809 } 2810 2811 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2812 u8 ip_proto, __be16 sport, 2813 __be16 dport) 2814 { 2815 struct sk_buff *skb; 2816 struct iphdr *iph; 2817 2818 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2819 if (!skb) 2820 return NULL; 2821 2822 /* Reserve room for dummy headers, this skb can pass 2823 * through good chunk of routing engine. 2824 */ 2825 skb_reset_mac_header(skb); 2826 skb_reset_network_header(skb); 2827 skb->protocol = htons(ETH_P_IP); 2828 iph = skb_put(skb, sizeof(struct iphdr)); 2829 iph->protocol = ip_proto; 2830 iph->saddr = src; 2831 iph->daddr = dst; 2832 iph->version = 0x4; 2833 iph->frag_off = 0; 2834 iph->ihl = 0x5; 2835 skb_set_transport_header(skb, skb->len); 2836 2837 switch (iph->protocol) { 2838 case IPPROTO_UDP: { 2839 struct udphdr *udph; 2840 2841 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2842 udph->source = sport; 2843 udph->dest = dport; 2844 udph->len = sizeof(struct udphdr); 2845 udph->check = 0; 2846 break; 2847 } 2848 case IPPROTO_TCP: { 2849 struct tcphdr *tcph; 2850 2851 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2852 tcph->source = sport; 2853 tcph->dest = dport; 2854 tcph->doff = sizeof(struct tcphdr) / 4; 2855 tcph->rst = 1; 2856 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2857 src, dst, 0); 2858 break; 2859 } 2860 case IPPROTO_ICMP: { 2861 struct icmphdr *icmph; 2862 2863 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2864 icmph->type = ICMP_ECHO; 2865 icmph->code = 0; 2866 } 2867 } 2868 2869 return skb; 2870 } 2871 2872 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 2873 const struct nlmsghdr *nlh, 2874 struct nlattr **tb, 2875 struct netlink_ext_ack *extack) 2876 { 2877 struct rtmsg *rtm; 2878 int i, err; 2879 2880 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 2881 NL_SET_ERR_MSG(extack, 2882 "ipv4: Invalid header for route get request"); 2883 return -EINVAL; 2884 } 2885 2886 if (!netlink_strict_get_check(skb)) 2887 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 2888 rtm_ipv4_policy, extack); 2889 2890 rtm = nlmsg_data(nlh); 2891 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 2892 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 2893 rtm->rtm_table || rtm->rtm_protocol || 2894 rtm->rtm_scope || rtm->rtm_type) { 2895 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 2896 return -EINVAL; 2897 } 2898 2899 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 2900 RTM_F_LOOKUP_TABLE | 2901 RTM_F_FIB_MATCH)) { 2902 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 2903 return -EINVAL; 2904 } 2905 2906 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 2907 rtm_ipv4_policy, extack); 2908 if (err) 2909 return err; 2910 2911 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 2912 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 2913 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 2914 return -EINVAL; 2915 } 2916 2917 for (i = 0; i <= RTA_MAX; i++) { 2918 if (!tb[i]) 2919 continue; 2920 2921 switch (i) { 2922 case RTA_IIF: 2923 case RTA_OIF: 2924 case RTA_SRC: 2925 case RTA_DST: 2926 case RTA_IP_PROTO: 2927 case RTA_SPORT: 2928 case RTA_DPORT: 2929 case RTA_MARK: 2930 case RTA_UID: 2931 break; 2932 default: 2933 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 2934 return -EINVAL; 2935 } 2936 } 2937 2938 return 0; 2939 } 2940 2941 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2942 struct netlink_ext_ack *extack) 2943 { 2944 struct net *net = sock_net(in_skb->sk); 2945 struct nlattr *tb[RTA_MAX+1]; 2946 u32 table_id = RT_TABLE_MAIN; 2947 __be16 sport = 0, dport = 0; 2948 struct fib_result res = {}; 2949 u8 ip_proto = IPPROTO_UDP; 2950 struct rtable *rt = NULL; 2951 struct sk_buff *skb; 2952 struct rtmsg *rtm; 2953 struct flowi4 fl4 = {}; 2954 __be32 dst = 0; 2955 __be32 src = 0; 2956 kuid_t uid; 2957 u32 iif; 2958 int err; 2959 int mark; 2960 2961 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 2962 if (err < 0) 2963 return err; 2964 2965 rtm = nlmsg_data(nlh); 2966 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2967 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2968 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2969 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2970 if (tb[RTA_UID]) 2971 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2972 else 2973 uid = (iif ? INVALID_UID : current_uid()); 2974 2975 if (tb[RTA_IP_PROTO]) { 2976 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2977 &ip_proto, AF_INET, extack); 2978 if (err) 2979 return err; 2980 } 2981 2982 if (tb[RTA_SPORT]) 2983 sport = nla_get_be16(tb[RTA_SPORT]); 2984 2985 if (tb[RTA_DPORT]) 2986 dport = nla_get_be16(tb[RTA_DPORT]); 2987 2988 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2989 if (!skb) 2990 return -ENOBUFS; 2991 2992 fl4.daddr = dst; 2993 fl4.saddr = src; 2994 fl4.flowi4_tos = rtm->rtm_tos; 2995 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2996 fl4.flowi4_mark = mark; 2997 fl4.flowi4_uid = uid; 2998 if (sport) 2999 fl4.fl4_sport = sport; 3000 if (dport) 3001 fl4.fl4_dport = dport; 3002 fl4.flowi4_proto = ip_proto; 3003 3004 rcu_read_lock(); 3005 3006 if (iif) { 3007 struct net_device *dev; 3008 3009 dev = dev_get_by_index_rcu(net, iif); 3010 if (!dev) { 3011 err = -ENODEV; 3012 goto errout_rcu; 3013 } 3014 3015 fl4.flowi4_iif = iif; /* for rt_fill_info */ 3016 skb->dev = dev; 3017 skb->mark = mark; 3018 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 3019 dev, &res); 3020 3021 rt = skb_rtable(skb); 3022 if (err == 0 && rt->dst.error) 3023 err = -rt->dst.error; 3024 } else { 3025 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3026 skb->dev = net->loopback_dev; 3027 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3028 err = 0; 3029 if (IS_ERR(rt)) 3030 err = PTR_ERR(rt); 3031 else 3032 skb_dst_set(skb, &rt->dst); 3033 } 3034 3035 if (err) 3036 goto errout_rcu; 3037 3038 if (rtm->rtm_flags & RTM_F_NOTIFY) 3039 rt->rt_flags |= RTCF_NOTIFY; 3040 3041 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3042 table_id = res.table ? res.table->tb_id : 0; 3043 3044 /* reset skb for netlink reply msg */ 3045 skb_trim(skb, 0); 3046 skb_reset_network_header(skb); 3047 skb_reset_transport_header(skb); 3048 skb_reset_mac_header(skb); 3049 3050 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3051 if (!res.fi) { 3052 err = fib_props[res.type].error; 3053 if (!err) 3054 err = -EHOSTUNREACH; 3055 goto errout_rcu; 3056 } 3057 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3058 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 3059 rt->rt_type, res.prefix, res.prefixlen, 3060 fl4.flowi4_tos, res.fi, 0); 3061 } else { 3062 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3063 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 3064 } 3065 if (err < 0) 3066 goto errout_rcu; 3067 3068 rcu_read_unlock(); 3069 3070 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3071 3072 errout_free: 3073 return err; 3074 errout_rcu: 3075 rcu_read_unlock(); 3076 kfree_skb(skb); 3077 goto errout_free; 3078 } 3079 3080 void ip_rt_multicast_event(struct in_device *in_dev) 3081 { 3082 rt_cache_flush(dev_net(in_dev->dev)); 3083 } 3084 3085 #ifdef CONFIG_SYSCTL 3086 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3087 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3088 static int ip_rt_gc_elasticity __read_mostly = 8; 3089 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3090 3091 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3092 void __user *buffer, 3093 size_t *lenp, loff_t *ppos) 3094 { 3095 struct net *net = (struct net *)__ctl->extra1; 3096 3097 if (write) { 3098 rt_cache_flush(net); 3099 fnhe_genid_bump(net); 3100 return 0; 3101 } 3102 3103 return -EINVAL; 3104 } 3105 3106 static struct ctl_table ipv4_route_table[] = { 3107 { 3108 .procname = "gc_thresh", 3109 .data = &ipv4_dst_ops.gc_thresh, 3110 .maxlen = sizeof(int), 3111 .mode = 0644, 3112 .proc_handler = proc_dointvec, 3113 }, 3114 { 3115 .procname = "max_size", 3116 .data = &ip_rt_max_size, 3117 .maxlen = sizeof(int), 3118 .mode = 0644, 3119 .proc_handler = proc_dointvec, 3120 }, 3121 { 3122 /* Deprecated. Use gc_min_interval_ms */ 3123 3124 .procname = "gc_min_interval", 3125 .data = &ip_rt_gc_min_interval, 3126 .maxlen = sizeof(int), 3127 .mode = 0644, 3128 .proc_handler = proc_dointvec_jiffies, 3129 }, 3130 { 3131 .procname = "gc_min_interval_ms", 3132 .data = &ip_rt_gc_min_interval, 3133 .maxlen = sizeof(int), 3134 .mode = 0644, 3135 .proc_handler = proc_dointvec_ms_jiffies, 3136 }, 3137 { 3138 .procname = "gc_timeout", 3139 .data = &ip_rt_gc_timeout, 3140 .maxlen = sizeof(int), 3141 .mode = 0644, 3142 .proc_handler = proc_dointvec_jiffies, 3143 }, 3144 { 3145 .procname = "gc_interval", 3146 .data = &ip_rt_gc_interval, 3147 .maxlen = sizeof(int), 3148 .mode = 0644, 3149 .proc_handler = proc_dointvec_jiffies, 3150 }, 3151 { 3152 .procname = "redirect_load", 3153 .data = &ip_rt_redirect_load, 3154 .maxlen = sizeof(int), 3155 .mode = 0644, 3156 .proc_handler = proc_dointvec, 3157 }, 3158 { 3159 .procname = "redirect_number", 3160 .data = &ip_rt_redirect_number, 3161 .maxlen = sizeof(int), 3162 .mode = 0644, 3163 .proc_handler = proc_dointvec, 3164 }, 3165 { 3166 .procname = "redirect_silence", 3167 .data = &ip_rt_redirect_silence, 3168 .maxlen = sizeof(int), 3169 .mode = 0644, 3170 .proc_handler = proc_dointvec, 3171 }, 3172 { 3173 .procname = "error_cost", 3174 .data = &ip_rt_error_cost, 3175 .maxlen = sizeof(int), 3176 .mode = 0644, 3177 .proc_handler = proc_dointvec, 3178 }, 3179 { 3180 .procname = "error_burst", 3181 .data = &ip_rt_error_burst, 3182 .maxlen = sizeof(int), 3183 .mode = 0644, 3184 .proc_handler = proc_dointvec, 3185 }, 3186 { 3187 .procname = "gc_elasticity", 3188 .data = &ip_rt_gc_elasticity, 3189 .maxlen = sizeof(int), 3190 .mode = 0644, 3191 .proc_handler = proc_dointvec, 3192 }, 3193 { 3194 .procname = "mtu_expires", 3195 .data = &ip_rt_mtu_expires, 3196 .maxlen = sizeof(int), 3197 .mode = 0644, 3198 .proc_handler = proc_dointvec_jiffies, 3199 }, 3200 { 3201 .procname = "min_pmtu", 3202 .data = &ip_rt_min_pmtu, 3203 .maxlen = sizeof(int), 3204 .mode = 0644, 3205 .proc_handler = proc_dointvec_minmax, 3206 .extra1 = &ip_min_valid_pmtu, 3207 }, 3208 { 3209 .procname = "min_adv_mss", 3210 .data = &ip_rt_min_advmss, 3211 .maxlen = sizeof(int), 3212 .mode = 0644, 3213 .proc_handler = proc_dointvec, 3214 }, 3215 { } 3216 }; 3217 3218 static struct ctl_table ipv4_route_flush_table[] = { 3219 { 3220 .procname = "flush", 3221 .maxlen = sizeof(int), 3222 .mode = 0200, 3223 .proc_handler = ipv4_sysctl_rtcache_flush, 3224 }, 3225 { }, 3226 }; 3227 3228 static __net_init int sysctl_route_net_init(struct net *net) 3229 { 3230 struct ctl_table *tbl; 3231 3232 tbl = ipv4_route_flush_table; 3233 if (!net_eq(net, &init_net)) { 3234 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3235 if (!tbl) 3236 goto err_dup; 3237 3238 /* Don't export sysctls to unprivileged users */ 3239 if (net->user_ns != &init_user_ns) 3240 tbl[0].procname = NULL; 3241 } 3242 tbl[0].extra1 = net; 3243 3244 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3245 if (!net->ipv4.route_hdr) 3246 goto err_reg; 3247 return 0; 3248 3249 err_reg: 3250 if (tbl != ipv4_route_flush_table) 3251 kfree(tbl); 3252 err_dup: 3253 return -ENOMEM; 3254 } 3255 3256 static __net_exit void sysctl_route_net_exit(struct net *net) 3257 { 3258 struct ctl_table *tbl; 3259 3260 tbl = net->ipv4.route_hdr->ctl_table_arg; 3261 unregister_net_sysctl_table(net->ipv4.route_hdr); 3262 BUG_ON(tbl == ipv4_route_flush_table); 3263 kfree(tbl); 3264 } 3265 3266 static __net_initdata struct pernet_operations sysctl_route_ops = { 3267 .init = sysctl_route_net_init, 3268 .exit = sysctl_route_net_exit, 3269 }; 3270 #endif 3271 3272 static __net_init int rt_genid_init(struct net *net) 3273 { 3274 atomic_set(&net->ipv4.rt_genid, 0); 3275 atomic_set(&net->fnhe_genid, 0); 3276 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3277 return 0; 3278 } 3279 3280 static __net_initdata struct pernet_operations rt_genid_ops = { 3281 .init = rt_genid_init, 3282 }; 3283 3284 static int __net_init ipv4_inetpeer_init(struct net *net) 3285 { 3286 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3287 3288 if (!bp) 3289 return -ENOMEM; 3290 inet_peer_base_init(bp); 3291 net->ipv4.peers = bp; 3292 return 0; 3293 } 3294 3295 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3296 { 3297 struct inet_peer_base *bp = net->ipv4.peers; 3298 3299 net->ipv4.peers = NULL; 3300 inetpeer_invalidate_tree(bp); 3301 kfree(bp); 3302 } 3303 3304 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3305 .init = ipv4_inetpeer_init, 3306 .exit = ipv4_inetpeer_exit, 3307 }; 3308 3309 #ifdef CONFIG_IP_ROUTE_CLASSID 3310 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3311 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3312 3313 int __init ip_rt_init(void) 3314 { 3315 int cpu; 3316 3317 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3318 GFP_KERNEL); 3319 if (!ip_idents) 3320 panic("IP: failed to allocate ip_idents\n"); 3321 3322 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3323 3324 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3325 if (!ip_tstamps) 3326 panic("IP: failed to allocate ip_tstamps\n"); 3327 3328 for_each_possible_cpu(cpu) { 3329 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3330 3331 INIT_LIST_HEAD(&ul->head); 3332 spin_lock_init(&ul->lock); 3333 } 3334 #ifdef CONFIG_IP_ROUTE_CLASSID 3335 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3336 if (!ip_rt_acct) 3337 panic("IP: failed to allocate ip_rt_acct\n"); 3338 #endif 3339 3340 ipv4_dst_ops.kmem_cachep = 3341 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3342 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3343 3344 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3345 3346 if (dst_entries_init(&ipv4_dst_ops) < 0) 3347 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3348 3349 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3350 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3351 3352 ipv4_dst_ops.gc_thresh = ~0; 3353 ip_rt_max_size = INT_MAX; 3354 3355 devinet_init(); 3356 ip_fib_init(); 3357 3358 if (ip_rt_proc_init()) 3359 pr_err("Unable to create route proc files\n"); 3360 #ifdef CONFIG_XFRM 3361 xfrm_init(); 3362 xfrm4_init(); 3363 #endif 3364 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3365 RTNL_FLAG_DOIT_UNLOCKED); 3366 3367 #ifdef CONFIG_SYSCTL 3368 register_pernet_subsys(&sysctl_route_ops); 3369 #endif 3370 register_pernet_subsys(&rt_genid_ops); 3371 register_pernet_subsys(&ipv4_inetpeer_ops); 3372 return 0; 3373 } 3374 3375 #ifdef CONFIG_SYSCTL 3376 /* 3377 * We really need to sanitize the damn ipv4 init order, then all 3378 * this nonsense will go away. 3379 */ 3380 void __init ip_static_sysctl_init(void) 3381 { 3382 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3383 } 3384 #endif 3385