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 } 1934 mhash = flow_hash_from_keys(&hash_keys); 1935 1936 if (multipath_hash) 1937 mhash = jhash_2words(mhash, multipath_hash, 0); 1938 1939 return mhash >> 1; 1940 } 1941 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 1942 1943 static int ip_mkroute_input(struct sk_buff *skb, 1944 struct fib_result *res, 1945 struct in_device *in_dev, 1946 __be32 daddr, __be32 saddr, u32 tos, 1947 struct flow_keys *hkeys) 1948 { 1949 #ifdef CONFIG_IP_ROUTE_MULTIPATH 1950 if (res->fi && fib_info_num_path(res->fi) > 1) { 1951 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys); 1952 1953 fib_select_multipath(res, h); 1954 } 1955 #endif 1956 1957 /* create a routing cache entry */ 1958 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); 1959 } 1960 1961 /* 1962 * NOTE. We drop all the packets that has local source 1963 * addresses, because every properly looped back packet 1964 * must have correct destination already attached by output routine. 1965 * 1966 * Such approach solves two big problems: 1967 * 1. Not simplex devices are handled properly. 1968 * 2. IP spoofing attempts are filtered with 100% of guarantee. 1969 * called with rcu_read_lock() 1970 */ 1971 1972 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1973 u8 tos, struct net_device *dev, 1974 struct fib_result *res) 1975 { 1976 struct in_device *in_dev = __in_dev_get_rcu(dev); 1977 struct flow_keys *flkeys = NULL, _flkeys; 1978 struct net *net = dev_net(dev); 1979 struct ip_tunnel_info *tun_info; 1980 int err = -EINVAL; 1981 unsigned int flags = 0; 1982 u32 itag = 0; 1983 struct rtable *rth; 1984 struct flowi4 fl4; 1985 bool do_cache = true; 1986 1987 /* IP on this device is disabled. */ 1988 1989 if (!in_dev) 1990 goto out; 1991 1992 /* Check for the most weird martians, which can be not detected 1993 by fib_lookup. 1994 */ 1995 1996 tun_info = skb_tunnel_info(skb); 1997 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1998 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id; 1999 else 2000 fl4.flowi4_tun_key.tun_id = 0; 2001 skb_dst_drop(skb); 2002 2003 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) 2004 goto martian_source; 2005 2006 res->fi = NULL; 2007 res->table = NULL; 2008 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2009 goto brd_input; 2010 2011 /* Accept zero addresses only to limited broadcast; 2012 * I even do not know to fix it or not. Waiting for complains :-) 2013 */ 2014 if (ipv4_is_zeronet(saddr)) 2015 goto martian_source; 2016 2017 if (ipv4_is_zeronet(daddr)) 2018 goto martian_destination; 2019 2020 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), 2021 * and call it once if daddr or/and saddr are loopback addresses 2022 */ 2023 if (ipv4_is_loopback(daddr)) { 2024 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2025 goto martian_destination; 2026 } else if (ipv4_is_loopback(saddr)) { 2027 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) 2028 goto martian_source; 2029 } 2030 2031 /* 2032 * Now we are ready to route packet. 2033 */ 2034 fl4.flowi4_oif = 0; 2035 fl4.flowi4_iif = dev->ifindex; 2036 fl4.flowi4_mark = skb->mark; 2037 fl4.flowi4_tos = tos; 2038 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2039 fl4.flowi4_flags = 0; 2040 fl4.daddr = daddr; 2041 fl4.saddr = saddr; 2042 fl4.flowi4_uid = sock_net_uid(net, NULL); 2043 2044 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { 2045 flkeys = &_flkeys; 2046 } else { 2047 fl4.flowi4_proto = 0; 2048 fl4.fl4_sport = 0; 2049 fl4.fl4_dport = 0; 2050 } 2051 2052 err = fib_lookup(net, &fl4, res, 0); 2053 if (err != 0) { 2054 if (!IN_DEV_FORWARD(in_dev)) 2055 err = -EHOSTUNREACH; 2056 goto no_route; 2057 } 2058 2059 if (res->type == RTN_BROADCAST) { 2060 if (IN_DEV_BFORWARD(in_dev)) 2061 goto make_route; 2062 /* not do cache if bc_forwarding is enabled */ 2063 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING)) 2064 do_cache = false; 2065 goto brd_input; 2066 } 2067 2068 if (res->type == RTN_LOCAL) { 2069 err = fib_validate_source(skb, saddr, daddr, tos, 2070 0, dev, in_dev, &itag); 2071 if (err < 0) 2072 goto martian_source; 2073 goto local_input; 2074 } 2075 2076 if (!IN_DEV_FORWARD(in_dev)) { 2077 err = -EHOSTUNREACH; 2078 goto no_route; 2079 } 2080 if (res->type != RTN_UNICAST) 2081 goto martian_destination; 2082 2083 make_route: 2084 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys); 2085 out: return err; 2086 2087 brd_input: 2088 if (skb->protocol != htons(ETH_P_IP)) 2089 goto e_inval; 2090 2091 if (!ipv4_is_zeronet(saddr)) { 2092 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, 2093 in_dev, &itag); 2094 if (err < 0) 2095 goto martian_source; 2096 } 2097 flags |= RTCF_BROADCAST; 2098 res->type = RTN_BROADCAST; 2099 RT_CACHE_STAT_INC(in_brd); 2100 2101 local_input: 2102 do_cache &= res->fi && !itag; 2103 if (do_cache) { 2104 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2105 2106 rth = rcu_dereference(nhc->nhc_rth_input); 2107 if (rt_cache_valid(rth)) { 2108 skb_dst_set_noref(skb, &rth->dst); 2109 err = 0; 2110 goto out; 2111 } 2112 } 2113 2114 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev, 2115 flags | RTCF_LOCAL, res->type, 2116 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache); 2117 if (!rth) 2118 goto e_nobufs; 2119 2120 rth->dst.output= ip_rt_bug; 2121 #ifdef CONFIG_IP_ROUTE_CLASSID 2122 rth->dst.tclassid = itag; 2123 #endif 2124 rth->rt_is_input = 1; 2125 2126 RT_CACHE_STAT_INC(in_slow_tot); 2127 if (res->type == RTN_UNREACHABLE) { 2128 rth->dst.input= ip_error; 2129 rth->dst.error= -err; 2130 rth->rt_flags &= ~RTCF_LOCAL; 2131 } 2132 2133 if (do_cache) { 2134 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2135 2136 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate); 2137 if (lwtunnel_input_redirect(rth->dst.lwtstate)) { 2138 WARN_ON(rth->dst.input == lwtunnel_input); 2139 rth->dst.lwtstate->orig_input = rth->dst.input; 2140 rth->dst.input = lwtunnel_input; 2141 } 2142 2143 if (unlikely(!rt_cache_route(nhc, rth))) 2144 rt_add_uncached_list(rth); 2145 } 2146 skb_dst_set(skb, &rth->dst); 2147 err = 0; 2148 goto out; 2149 2150 no_route: 2151 RT_CACHE_STAT_INC(in_no_route); 2152 res->type = RTN_UNREACHABLE; 2153 res->fi = NULL; 2154 res->table = NULL; 2155 goto local_input; 2156 2157 /* 2158 * Do not cache martian addresses: they should be logged (RFC1812) 2159 */ 2160 martian_destination: 2161 RT_CACHE_STAT_INC(in_martian_dst); 2162 #ifdef CONFIG_IP_ROUTE_VERBOSE 2163 if (IN_DEV_LOG_MARTIANS(in_dev)) 2164 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n", 2165 &daddr, &saddr, dev->name); 2166 #endif 2167 2168 e_inval: 2169 err = -EINVAL; 2170 goto out; 2171 2172 e_nobufs: 2173 err = -ENOBUFS; 2174 goto out; 2175 2176 martian_source: 2177 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2178 goto out; 2179 } 2180 2181 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2182 u8 tos, struct net_device *dev) 2183 { 2184 struct fib_result res; 2185 int err; 2186 2187 tos &= IPTOS_RT_MASK; 2188 rcu_read_lock(); 2189 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res); 2190 rcu_read_unlock(); 2191 2192 return err; 2193 } 2194 EXPORT_SYMBOL(ip_route_input_noref); 2195 2196 /* called with rcu_read_lock held */ 2197 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2198 u8 tos, struct net_device *dev, struct fib_result *res) 2199 { 2200 /* Multicast recognition logic is moved from route cache to here. 2201 The problem was that too many Ethernet cards have broken/missing 2202 hardware multicast filters :-( As result the host on multicasting 2203 network acquires a lot of useless route cache entries, sort of 2204 SDR messages from all the world. Now we try to get rid of them. 2205 Really, provided software IP multicast filter is organized 2206 reasonably (at least, hashed), it does not result in a slowdown 2207 comparing with route cache reject entries. 2208 Note, that multicast routers are not affected, because 2209 route cache entry is created eventually. 2210 */ 2211 if (ipv4_is_multicast(daddr)) { 2212 struct in_device *in_dev = __in_dev_get_rcu(dev); 2213 int our = 0; 2214 int err = -EINVAL; 2215 2216 if (!in_dev) 2217 return err; 2218 our = ip_check_mc_rcu(in_dev, daddr, saddr, 2219 ip_hdr(skb)->protocol); 2220 2221 /* check l3 master if no match yet */ 2222 if (!our && netif_is_l3_slave(dev)) { 2223 struct in_device *l3_in_dev; 2224 2225 l3_in_dev = __in_dev_get_rcu(skb->dev); 2226 if (l3_in_dev) 2227 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr, 2228 ip_hdr(skb)->protocol); 2229 } 2230 2231 if (our 2232 #ifdef CONFIG_IP_MROUTE 2233 || 2234 (!ipv4_is_local_multicast(daddr) && 2235 IN_DEV_MFORWARD(in_dev)) 2236 #endif 2237 ) { 2238 err = ip_route_input_mc(skb, daddr, saddr, 2239 tos, dev, our); 2240 } 2241 return err; 2242 } 2243 2244 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res); 2245 } 2246 2247 /* called with rcu_read_lock() */ 2248 static struct rtable *__mkroute_output(const struct fib_result *res, 2249 const struct flowi4 *fl4, int orig_oif, 2250 struct net_device *dev_out, 2251 unsigned int flags) 2252 { 2253 struct fib_info *fi = res->fi; 2254 struct fib_nh_exception *fnhe; 2255 struct in_device *in_dev; 2256 u16 type = res->type; 2257 struct rtable *rth; 2258 bool do_cache; 2259 2260 in_dev = __in_dev_get_rcu(dev_out); 2261 if (!in_dev) 2262 return ERR_PTR(-EINVAL); 2263 2264 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) 2265 if (ipv4_is_loopback(fl4->saddr) && 2266 !(dev_out->flags & IFF_LOOPBACK) && 2267 !netif_is_l3_master(dev_out)) 2268 return ERR_PTR(-EINVAL); 2269 2270 if (ipv4_is_lbcast(fl4->daddr)) 2271 type = RTN_BROADCAST; 2272 else if (ipv4_is_multicast(fl4->daddr)) 2273 type = RTN_MULTICAST; 2274 else if (ipv4_is_zeronet(fl4->daddr)) 2275 return ERR_PTR(-EINVAL); 2276 2277 if (dev_out->flags & IFF_LOOPBACK) 2278 flags |= RTCF_LOCAL; 2279 2280 do_cache = true; 2281 if (type == RTN_BROADCAST) { 2282 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2283 fi = NULL; 2284 } else if (type == RTN_MULTICAST) { 2285 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2286 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2287 fl4->flowi4_proto)) 2288 flags &= ~RTCF_LOCAL; 2289 else 2290 do_cache = false; 2291 /* If multicast route do not exist use 2292 * default one, but do not gateway in this case. 2293 * Yes, it is hack. 2294 */ 2295 if (fi && res->prefixlen < 4) 2296 fi = NULL; 2297 } else if ((type == RTN_LOCAL) && (orig_oif != 0) && 2298 (orig_oif != dev_out->ifindex)) { 2299 /* For local routes that require a particular output interface 2300 * we do not want to cache the result. Caching the result 2301 * causes incorrect behaviour when there are multiple source 2302 * addresses on the interface, the end result being that if the 2303 * intended recipient is waiting on that interface for the 2304 * packet he won't receive it because it will be delivered on 2305 * the loopback interface and the IP_PKTINFO ipi_ifindex will 2306 * be set to the loopback interface as well. 2307 */ 2308 do_cache = false; 2309 } 2310 2311 fnhe = NULL; 2312 do_cache &= fi != NULL; 2313 if (fi) { 2314 struct fib_nh_common *nhc = FIB_RES_NHC(*res); 2315 struct rtable __rcu **prth; 2316 2317 fnhe = find_exception(nhc, fl4->daddr); 2318 if (!do_cache) 2319 goto add; 2320 if (fnhe) { 2321 prth = &fnhe->fnhe_rth_output; 2322 } else { 2323 if (unlikely(fl4->flowi4_flags & 2324 FLOWI_FLAG_KNOWN_NH && 2325 !(nhc->nhc_gw_family && 2326 nhc->nhc_scope == RT_SCOPE_LINK))) { 2327 do_cache = false; 2328 goto add; 2329 } 2330 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output); 2331 } 2332 rth = rcu_dereference(*prth); 2333 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst)) 2334 return rth; 2335 } 2336 2337 add: 2338 rth = rt_dst_alloc(dev_out, flags, type, 2339 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2340 IN_DEV_CONF_GET(in_dev, NOXFRM), 2341 do_cache); 2342 if (!rth) 2343 return ERR_PTR(-ENOBUFS); 2344 2345 rth->rt_iif = orig_oif; 2346 2347 RT_CACHE_STAT_INC(out_slow_tot); 2348 2349 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2350 if (flags & RTCF_LOCAL && 2351 !(dev_out->flags & IFF_LOOPBACK)) { 2352 rth->dst.output = ip_mc_output; 2353 RT_CACHE_STAT_INC(out_slow_mc); 2354 } 2355 #ifdef CONFIG_IP_MROUTE 2356 if (type == RTN_MULTICAST) { 2357 if (IN_DEV_MFORWARD(in_dev) && 2358 !ipv4_is_local_multicast(fl4->daddr)) { 2359 rth->dst.input = ip_mr_input; 2360 rth->dst.output = ip_mc_output; 2361 } 2362 } 2363 #endif 2364 } 2365 2366 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache); 2367 lwtunnel_set_redirect(&rth->dst); 2368 2369 return rth; 2370 } 2371 2372 /* 2373 * Major route resolver routine. 2374 */ 2375 2376 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4, 2377 const struct sk_buff *skb) 2378 { 2379 __u8 tos = RT_FL_TOS(fl4); 2380 struct fib_result res = { 2381 .type = RTN_UNSPEC, 2382 .fi = NULL, 2383 .table = NULL, 2384 .tclassid = 0, 2385 }; 2386 struct rtable *rth; 2387 2388 fl4->flowi4_iif = LOOPBACK_IFINDEX; 2389 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2390 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2391 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2392 2393 rcu_read_lock(); 2394 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb); 2395 rcu_read_unlock(); 2396 2397 return rth; 2398 } 2399 EXPORT_SYMBOL_GPL(ip_route_output_key_hash); 2400 2401 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4, 2402 struct fib_result *res, 2403 const struct sk_buff *skb) 2404 { 2405 struct net_device *dev_out = NULL; 2406 int orig_oif = fl4->flowi4_oif; 2407 unsigned int flags = 0; 2408 struct rtable *rth; 2409 int err = -ENETUNREACH; 2410 2411 if (fl4->saddr) { 2412 rth = ERR_PTR(-EINVAL); 2413 if (ipv4_is_multicast(fl4->saddr) || 2414 ipv4_is_lbcast(fl4->saddr) || 2415 ipv4_is_zeronet(fl4->saddr)) 2416 goto out; 2417 2418 /* I removed check for oif == dev_out->oif here. 2419 It was wrong for two reasons: 2420 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2421 is assigned to multiple interfaces. 2422 2. Moreover, we are allowed to send packets with saddr 2423 of another iface. --ANK 2424 */ 2425 2426 if (fl4->flowi4_oif == 0 && 2427 (ipv4_is_multicast(fl4->daddr) || 2428 ipv4_is_lbcast(fl4->daddr))) { 2429 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2430 dev_out = __ip_dev_find(net, fl4->saddr, false); 2431 if (!dev_out) 2432 goto out; 2433 2434 /* Special hack: user can direct multicasts 2435 and limited broadcast via necessary interface 2436 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2437 This hack is not just for fun, it allows 2438 vic,vat and friends to work. 2439 They bind socket to loopback, set ttl to zero 2440 and expect that it will work. 2441 From the viewpoint of routing cache they are broken, 2442 because we are not allowed to build multicast path 2443 with loopback source addr (look, routing cache 2444 cannot know, that ttl is zero, so that packet 2445 will not leave this host and route is valid). 2446 Luckily, this hack is good workaround. 2447 */ 2448 2449 fl4->flowi4_oif = dev_out->ifindex; 2450 goto make_route; 2451 } 2452 2453 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2454 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2455 if (!__ip_dev_find(net, fl4->saddr, false)) 2456 goto out; 2457 } 2458 } 2459 2460 2461 if (fl4->flowi4_oif) { 2462 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2463 rth = ERR_PTR(-ENODEV); 2464 if (!dev_out) 2465 goto out; 2466 2467 /* RACE: Check return value of inet_select_addr instead. */ 2468 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2469 rth = ERR_PTR(-ENETUNREACH); 2470 goto out; 2471 } 2472 if (ipv4_is_local_multicast(fl4->daddr) || 2473 ipv4_is_lbcast(fl4->daddr) || 2474 fl4->flowi4_proto == IPPROTO_IGMP) { 2475 if (!fl4->saddr) 2476 fl4->saddr = inet_select_addr(dev_out, 0, 2477 RT_SCOPE_LINK); 2478 goto make_route; 2479 } 2480 if (!fl4->saddr) { 2481 if (ipv4_is_multicast(fl4->daddr)) 2482 fl4->saddr = inet_select_addr(dev_out, 0, 2483 fl4->flowi4_scope); 2484 else if (!fl4->daddr) 2485 fl4->saddr = inet_select_addr(dev_out, 0, 2486 RT_SCOPE_HOST); 2487 } 2488 } 2489 2490 if (!fl4->daddr) { 2491 fl4->daddr = fl4->saddr; 2492 if (!fl4->daddr) 2493 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2494 dev_out = net->loopback_dev; 2495 fl4->flowi4_oif = LOOPBACK_IFINDEX; 2496 res->type = RTN_LOCAL; 2497 flags |= RTCF_LOCAL; 2498 goto make_route; 2499 } 2500 2501 err = fib_lookup(net, fl4, res, 0); 2502 if (err) { 2503 res->fi = NULL; 2504 res->table = NULL; 2505 if (fl4->flowi4_oif && 2506 (ipv4_is_multicast(fl4->daddr) || 2507 !netif_index_is_l3_master(net, fl4->flowi4_oif))) { 2508 /* Apparently, routing tables are wrong. Assume, 2509 that the destination is on link. 2510 2511 WHY? DW. 2512 Because we are allowed to send to iface 2513 even if it has NO routes and NO assigned 2514 addresses. When oif is specified, routing 2515 tables are looked up with only one purpose: 2516 to catch if destination is gatewayed, rather than 2517 direct. Moreover, if MSG_DONTROUTE is set, 2518 we send packet, ignoring both routing tables 2519 and ifaddr state. --ANK 2520 2521 2522 We could make it even if oif is unknown, 2523 likely IPv6, but we do not. 2524 */ 2525 2526 if (fl4->saddr == 0) 2527 fl4->saddr = inet_select_addr(dev_out, 0, 2528 RT_SCOPE_LINK); 2529 res->type = RTN_UNICAST; 2530 goto make_route; 2531 } 2532 rth = ERR_PTR(err); 2533 goto out; 2534 } 2535 2536 if (res->type == RTN_LOCAL) { 2537 if (!fl4->saddr) { 2538 if (res->fi->fib_prefsrc) 2539 fl4->saddr = res->fi->fib_prefsrc; 2540 else 2541 fl4->saddr = fl4->daddr; 2542 } 2543 2544 /* L3 master device is the loopback for that domain */ 2545 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? : 2546 net->loopback_dev; 2547 2548 /* make sure orig_oif points to fib result device even 2549 * though packet rx/tx happens over loopback or l3mdev 2550 */ 2551 orig_oif = FIB_RES_OIF(*res); 2552 2553 fl4->flowi4_oif = dev_out->ifindex; 2554 flags |= RTCF_LOCAL; 2555 goto make_route; 2556 } 2557 2558 fib_select_path(net, res, fl4, skb); 2559 2560 dev_out = FIB_RES_DEV(*res); 2561 fl4->flowi4_oif = dev_out->ifindex; 2562 2563 2564 make_route: 2565 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags); 2566 2567 out: 2568 return rth; 2569 } 2570 2571 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2572 { 2573 return NULL; 2574 } 2575 2576 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2577 { 2578 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2579 2580 return mtu ? : dst->dev->mtu; 2581 } 2582 2583 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 2584 struct sk_buff *skb, u32 mtu) 2585 { 2586 } 2587 2588 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 2589 struct sk_buff *skb) 2590 { 2591 } 2592 2593 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2594 unsigned long old) 2595 { 2596 return NULL; 2597 } 2598 2599 static struct dst_ops ipv4_dst_blackhole_ops = { 2600 .family = AF_INET, 2601 .check = ipv4_blackhole_dst_check, 2602 .mtu = ipv4_blackhole_mtu, 2603 .default_advmss = ipv4_default_advmss, 2604 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2605 .redirect = ipv4_rt_blackhole_redirect, 2606 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2607 .neigh_lookup = ipv4_neigh_lookup, 2608 }; 2609 2610 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2611 { 2612 struct rtable *ort = (struct rtable *) dst_orig; 2613 struct rtable *rt; 2614 2615 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0); 2616 if (rt) { 2617 struct dst_entry *new = &rt->dst; 2618 2619 new->__use = 1; 2620 new->input = dst_discard; 2621 new->output = dst_discard_out; 2622 2623 new->dev = net->loopback_dev; 2624 if (new->dev) 2625 dev_hold(new->dev); 2626 2627 rt->rt_is_input = ort->rt_is_input; 2628 rt->rt_iif = ort->rt_iif; 2629 rt->rt_pmtu = ort->rt_pmtu; 2630 rt->rt_mtu_locked = ort->rt_mtu_locked; 2631 2632 rt->rt_genid = rt_genid_ipv4(net); 2633 rt->rt_flags = ort->rt_flags; 2634 rt->rt_type = ort->rt_type; 2635 rt->rt_gw_family = ort->rt_gw_family; 2636 if (rt->rt_gw_family == AF_INET) 2637 rt->rt_gw4 = ort->rt_gw4; 2638 else if (rt->rt_gw_family == AF_INET6) 2639 rt->rt_gw6 = ort->rt_gw6; 2640 2641 INIT_LIST_HEAD(&rt->rt_uncached); 2642 } 2643 2644 dst_release(dst_orig); 2645 2646 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2647 } 2648 2649 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2650 const struct sock *sk) 2651 { 2652 struct rtable *rt = __ip_route_output_key(net, flp4); 2653 2654 if (IS_ERR(rt)) 2655 return rt; 2656 2657 if (flp4->flowi4_proto) 2658 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst, 2659 flowi4_to_flowi(flp4), 2660 sk, 0); 2661 2662 return rt; 2663 } 2664 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2665 2666 /* called with rcu_read_lock held */ 2667 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, 2668 struct rtable *rt, u32 table_id, struct flowi4 *fl4, 2669 struct sk_buff *skb, u32 portid, u32 seq) 2670 { 2671 struct rtmsg *r; 2672 struct nlmsghdr *nlh; 2673 unsigned long expires = 0; 2674 u32 error; 2675 u32 metrics[RTAX_MAX]; 2676 2677 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0); 2678 if (!nlh) 2679 return -EMSGSIZE; 2680 2681 r = nlmsg_data(nlh); 2682 r->rtm_family = AF_INET; 2683 r->rtm_dst_len = 32; 2684 r->rtm_src_len = 0; 2685 r->rtm_tos = fl4->flowi4_tos; 2686 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT; 2687 if (nla_put_u32(skb, RTA_TABLE, table_id)) 2688 goto nla_put_failure; 2689 r->rtm_type = rt->rt_type; 2690 r->rtm_scope = RT_SCOPE_UNIVERSE; 2691 r->rtm_protocol = RTPROT_UNSPEC; 2692 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2693 if (rt->rt_flags & RTCF_NOTIFY) 2694 r->rtm_flags |= RTM_F_NOTIFY; 2695 if (IPCB(skb)->flags & IPSKB_DOREDIRECT) 2696 r->rtm_flags |= RTCF_DOREDIRECT; 2697 2698 if (nla_put_in_addr(skb, RTA_DST, dst)) 2699 goto nla_put_failure; 2700 if (src) { 2701 r->rtm_src_len = 32; 2702 if (nla_put_in_addr(skb, RTA_SRC, src)) 2703 goto nla_put_failure; 2704 } 2705 if (rt->dst.dev && 2706 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 2707 goto nla_put_failure; 2708 #ifdef CONFIG_IP_ROUTE_CLASSID 2709 if (rt->dst.tclassid && 2710 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid)) 2711 goto nla_put_failure; 2712 #endif 2713 if (!rt_is_input_route(rt) && 2714 fl4->saddr != src) { 2715 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr)) 2716 goto nla_put_failure; 2717 } 2718 if (rt->rt_gw_family == AF_INET && 2719 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) { 2720 goto nla_put_failure; 2721 } else if (rt->rt_gw_family == AF_INET6) { 2722 int alen = sizeof(struct in6_addr); 2723 struct nlattr *nla; 2724 struct rtvia *via; 2725 2726 nla = nla_reserve(skb, RTA_VIA, alen + 2); 2727 if (!nla) 2728 goto nla_put_failure; 2729 2730 via = nla_data(nla); 2731 via->rtvia_family = AF_INET6; 2732 memcpy(via->rtvia_addr, &rt->rt_gw6, alen); 2733 } 2734 2735 expires = rt->dst.expires; 2736 if (expires) { 2737 unsigned long now = jiffies; 2738 2739 if (time_before(now, expires)) 2740 expires -= now; 2741 else 2742 expires = 0; 2743 } 2744 2745 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 2746 if (rt->rt_pmtu && expires) 2747 metrics[RTAX_MTU - 1] = rt->rt_pmtu; 2748 if (rt->rt_mtu_locked && expires) 2749 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU); 2750 if (rtnetlink_put_metrics(skb, metrics) < 0) 2751 goto nla_put_failure; 2752 2753 if (fl4->flowi4_mark && 2754 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark)) 2755 goto nla_put_failure; 2756 2757 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) && 2758 nla_put_u32(skb, RTA_UID, 2759 from_kuid_munged(current_user_ns(), fl4->flowi4_uid))) 2760 goto nla_put_failure; 2761 2762 error = rt->dst.error; 2763 2764 if (rt_is_input_route(rt)) { 2765 #ifdef CONFIG_IP_MROUTE 2766 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2767 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2768 int err = ipmr_get_route(net, skb, 2769 fl4->saddr, fl4->daddr, 2770 r, portid); 2771 2772 if (err <= 0) { 2773 if (err == 0) 2774 return 0; 2775 goto nla_put_failure; 2776 } 2777 } else 2778 #endif 2779 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif)) 2780 goto nla_put_failure; 2781 } 2782 2783 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0) 2784 goto nla_put_failure; 2785 2786 nlmsg_end(skb, nlh); 2787 return 0; 2788 2789 nla_put_failure: 2790 nlmsg_cancel(skb, nlh); 2791 return -EMSGSIZE; 2792 } 2793 2794 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst, 2795 u8 ip_proto, __be16 sport, 2796 __be16 dport) 2797 { 2798 struct sk_buff *skb; 2799 struct iphdr *iph; 2800 2801 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2802 if (!skb) 2803 return NULL; 2804 2805 /* Reserve room for dummy headers, this skb can pass 2806 * through good chunk of routing engine. 2807 */ 2808 skb_reset_mac_header(skb); 2809 skb_reset_network_header(skb); 2810 skb->protocol = htons(ETH_P_IP); 2811 iph = skb_put(skb, sizeof(struct iphdr)); 2812 iph->protocol = ip_proto; 2813 iph->saddr = src; 2814 iph->daddr = dst; 2815 iph->version = 0x4; 2816 iph->frag_off = 0; 2817 iph->ihl = 0x5; 2818 skb_set_transport_header(skb, skb->len); 2819 2820 switch (iph->protocol) { 2821 case IPPROTO_UDP: { 2822 struct udphdr *udph; 2823 2824 udph = skb_put_zero(skb, sizeof(struct udphdr)); 2825 udph->source = sport; 2826 udph->dest = dport; 2827 udph->len = sizeof(struct udphdr); 2828 udph->check = 0; 2829 break; 2830 } 2831 case IPPROTO_TCP: { 2832 struct tcphdr *tcph; 2833 2834 tcph = skb_put_zero(skb, sizeof(struct tcphdr)); 2835 tcph->source = sport; 2836 tcph->dest = dport; 2837 tcph->doff = sizeof(struct tcphdr) / 4; 2838 tcph->rst = 1; 2839 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr), 2840 src, dst, 0); 2841 break; 2842 } 2843 case IPPROTO_ICMP: { 2844 struct icmphdr *icmph; 2845 2846 icmph = skb_put_zero(skb, sizeof(struct icmphdr)); 2847 icmph->type = ICMP_ECHO; 2848 icmph->code = 0; 2849 } 2850 } 2851 2852 return skb; 2853 } 2854 2855 static int inet_rtm_valid_getroute_req(struct sk_buff *skb, 2856 const struct nlmsghdr *nlh, 2857 struct nlattr **tb, 2858 struct netlink_ext_ack *extack) 2859 { 2860 struct rtmsg *rtm; 2861 int i, err; 2862 2863 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 2864 NL_SET_ERR_MSG(extack, 2865 "ipv4: Invalid header for route get request"); 2866 return -EINVAL; 2867 } 2868 2869 if (!netlink_strict_get_check(skb)) 2870 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 2871 rtm_ipv4_policy, extack); 2872 2873 rtm = nlmsg_data(nlh); 2874 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) || 2875 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) || 2876 rtm->rtm_table || rtm->rtm_protocol || 2877 rtm->rtm_scope || rtm->rtm_type) { 2878 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request"); 2879 return -EINVAL; 2880 } 2881 2882 if (rtm->rtm_flags & ~(RTM_F_NOTIFY | 2883 RTM_F_LOOKUP_TABLE | 2884 RTM_F_FIB_MATCH)) { 2885 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request"); 2886 return -EINVAL; 2887 } 2888 2889 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 2890 rtm_ipv4_policy, extack); 2891 if (err) 2892 return err; 2893 2894 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 2895 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 2896 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4"); 2897 return -EINVAL; 2898 } 2899 2900 for (i = 0; i <= RTA_MAX; i++) { 2901 if (!tb[i]) 2902 continue; 2903 2904 switch (i) { 2905 case RTA_IIF: 2906 case RTA_OIF: 2907 case RTA_SRC: 2908 case RTA_DST: 2909 case RTA_IP_PROTO: 2910 case RTA_SPORT: 2911 case RTA_DPORT: 2912 case RTA_MARK: 2913 case RTA_UID: 2914 break; 2915 default: 2916 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request"); 2917 return -EINVAL; 2918 } 2919 } 2920 2921 return 0; 2922 } 2923 2924 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 2925 struct netlink_ext_ack *extack) 2926 { 2927 struct net *net = sock_net(in_skb->sk); 2928 struct nlattr *tb[RTA_MAX+1]; 2929 u32 table_id = RT_TABLE_MAIN; 2930 __be16 sport = 0, dport = 0; 2931 struct fib_result res = {}; 2932 u8 ip_proto = IPPROTO_UDP; 2933 struct rtable *rt = NULL; 2934 struct sk_buff *skb; 2935 struct rtmsg *rtm; 2936 struct flowi4 fl4 = {}; 2937 __be32 dst = 0; 2938 __be32 src = 0; 2939 kuid_t uid; 2940 u32 iif; 2941 int err; 2942 int mark; 2943 2944 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 2945 if (err < 0) 2946 return err; 2947 2948 rtm = nlmsg_data(nlh); 2949 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0; 2950 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0; 2951 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2952 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2953 if (tb[RTA_UID]) 2954 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID])); 2955 else 2956 uid = (iif ? INVALID_UID : current_uid()); 2957 2958 if (tb[RTA_IP_PROTO]) { 2959 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 2960 &ip_proto, AF_INET, extack); 2961 if (err) 2962 return err; 2963 } 2964 2965 if (tb[RTA_SPORT]) 2966 sport = nla_get_be16(tb[RTA_SPORT]); 2967 2968 if (tb[RTA_DPORT]) 2969 dport = nla_get_be16(tb[RTA_DPORT]); 2970 2971 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport); 2972 if (!skb) 2973 return -ENOBUFS; 2974 2975 fl4.daddr = dst; 2976 fl4.saddr = src; 2977 fl4.flowi4_tos = rtm->rtm_tos; 2978 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0; 2979 fl4.flowi4_mark = mark; 2980 fl4.flowi4_uid = uid; 2981 if (sport) 2982 fl4.fl4_sport = sport; 2983 if (dport) 2984 fl4.fl4_dport = dport; 2985 fl4.flowi4_proto = ip_proto; 2986 2987 rcu_read_lock(); 2988 2989 if (iif) { 2990 struct net_device *dev; 2991 2992 dev = dev_get_by_index_rcu(net, iif); 2993 if (!dev) { 2994 err = -ENODEV; 2995 goto errout_rcu; 2996 } 2997 2998 fl4.flowi4_iif = iif; /* for rt_fill_info */ 2999 skb->dev = dev; 3000 skb->mark = mark; 3001 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, 3002 dev, &res); 3003 3004 rt = skb_rtable(skb); 3005 if (err == 0 && rt->dst.error) 3006 err = -rt->dst.error; 3007 } else { 3008 fl4.flowi4_iif = LOOPBACK_IFINDEX; 3009 skb->dev = net->loopback_dev; 3010 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); 3011 err = 0; 3012 if (IS_ERR(rt)) 3013 err = PTR_ERR(rt); 3014 else 3015 skb_dst_set(skb, &rt->dst); 3016 } 3017 3018 if (err) 3019 goto errout_rcu; 3020 3021 if (rtm->rtm_flags & RTM_F_NOTIFY) 3022 rt->rt_flags |= RTCF_NOTIFY; 3023 3024 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE) 3025 table_id = res.table ? res.table->tb_id : 0; 3026 3027 /* reset skb for netlink reply msg */ 3028 skb_trim(skb, 0); 3029 skb_reset_network_header(skb); 3030 skb_reset_transport_header(skb); 3031 skb_reset_mac_header(skb); 3032 3033 if (rtm->rtm_flags & RTM_F_FIB_MATCH) { 3034 if (!res.fi) { 3035 err = fib_props[res.type].error; 3036 if (!err) 3037 err = -EHOSTUNREACH; 3038 goto errout_rcu; 3039 } 3040 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid, 3041 nlh->nlmsg_seq, RTM_NEWROUTE, table_id, 3042 rt->rt_type, res.prefix, res.prefixlen, 3043 fl4.flowi4_tos, res.fi, 0); 3044 } else { 3045 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb, 3046 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); 3047 } 3048 if (err < 0) 3049 goto errout_rcu; 3050 3051 rcu_read_unlock(); 3052 3053 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3054 3055 errout_free: 3056 return err; 3057 errout_rcu: 3058 rcu_read_unlock(); 3059 kfree_skb(skb); 3060 goto errout_free; 3061 } 3062 3063 void ip_rt_multicast_event(struct in_device *in_dev) 3064 { 3065 rt_cache_flush(dev_net(in_dev->dev)); 3066 } 3067 3068 #ifdef CONFIG_SYSCTL 3069 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 3070 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 3071 static int ip_rt_gc_elasticity __read_mostly = 8; 3072 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU; 3073 3074 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write, 3075 void __user *buffer, 3076 size_t *lenp, loff_t *ppos) 3077 { 3078 struct net *net = (struct net *)__ctl->extra1; 3079 3080 if (write) { 3081 rt_cache_flush(net); 3082 fnhe_genid_bump(net); 3083 return 0; 3084 } 3085 3086 return -EINVAL; 3087 } 3088 3089 static struct ctl_table ipv4_route_table[] = { 3090 { 3091 .procname = "gc_thresh", 3092 .data = &ipv4_dst_ops.gc_thresh, 3093 .maxlen = sizeof(int), 3094 .mode = 0644, 3095 .proc_handler = proc_dointvec, 3096 }, 3097 { 3098 .procname = "max_size", 3099 .data = &ip_rt_max_size, 3100 .maxlen = sizeof(int), 3101 .mode = 0644, 3102 .proc_handler = proc_dointvec, 3103 }, 3104 { 3105 /* Deprecated. Use gc_min_interval_ms */ 3106 3107 .procname = "gc_min_interval", 3108 .data = &ip_rt_gc_min_interval, 3109 .maxlen = sizeof(int), 3110 .mode = 0644, 3111 .proc_handler = proc_dointvec_jiffies, 3112 }, 3113 { 3114 .procname = "gc_min_interval_ms", 3115 .data = &ip_rt_gc_min_interval, 3116 .maxlen = sizeof(int), 3117 .mode = 0644, 3118 .proc_handler = proc_dointvec_ms_jiffies, 3119 }, 3120 { 3121 .procname = "gc_timeout", 3122 .data = &ip_rt_gc_timeout, 3123 .maxlen = sizeof(int), 3124 .mode = 0644, 3125 .proc_handler = proc_dointvec_jiffies, 3126 }, 3127 { 3128 .procname = "gc_interval", 3129 .data = &ip_rt_gc_interval, 3130 .maxlen = sizeof(int), 3131 .mode = 0644, 3132 .proc_handler = proc_dointvec_jiffies, 3133 }, 3134 { 3135 .procname = "redirect_load", 3136 .data = &ip_rt_redirect_load, 3137 .maxlen = sizeof(int), 3138 .mode = 0644, 3139 .proc_handler = proc_dointvec, 3140 }, 3141 { 3142 .procname = "redirect_number", 3143 .data = &ip_rt_redirect_number, 3144 .maxlen = sizeof(int), 3145 .mode = 0644, 3146 .proc_handler = proc_dointvec, 3147 }, 3148 { 3149 .procname = "redirect_silence", 3150 .data = &ip_rt_redirect_silence, 3151 .maxlen = sizeof(int), 3152 .mode = 0644, 3153 .proc_handler = proc_dointvec, 3154 }, 3155 { 3156 .procname = "error_cost", 3157 .data = &ip_rt_error_cost, 3158 .maxlen = sizeof(int), 3159 .mode = 0644, 3160 .proc_handler = proc_dointvec, 3161 }, 3162 { 3163 .procname = "error_burst", 3164 .data = &ip_rt_error_burst, 3165 .maxlen = sizeof(int), 3166 .mode = 0644, 3167 .proc_handler = proc_dointvec, 3168 }, 3169 { 3170 .procname = "gc_elasticity", 3171 .data = &ip_rt_gc_elasticity, 3172 .maxlen = sizeof(int), 3173 .mode = 0644, 3174 .proc_handler = proc_dointvec, 3175 }, 3176 { 3177 .procname = "mtu_expires", 3178 .data = &ip_rt_mtu_expires, 3179 .maxlen = sizeof(int), 3180 .mode = 0644, 3181 .proc_handler = proc_dointvec_jiffies, 3182 }, 3183 { 3184 .procname = "min_pmtu", 3185 .data = &ip_rt_min_pmtu, 3186 .maxlen = sizeof(int), 3187 .mode = 0644, 3188 .proc_handler = proc_dointvec_minmax, 3189 .extra1 = &ip_min_valid_pmtu, 3190 }, 3191 { 3192 .procname = "min_adv_mss", 3193 .data = &ip_rt_min_advmss, 3194 .maxlen = sizeof(int), 3195 .mode = 0644, 3196 .proc_handler = proc_dointvec, 3197 }, 3198 { } 3199 }; 3200 3201 static struct ctl_table ipv4_route_flush_table[] = { 3202 { 3203 .procname = "flush", 3204 .maxlen = sizeof(int), 3205 .mode = 0200, 3206 .proc_handler = ipv4_sysctl_rtcache_flush, 3207 }, 3208 { }, 3209 }; 3210 3211 static __net_init int sysctl_route_net_init(struct net *net) 3212 { 3213 struct ctl_table *tbl; 3214 3215 tbl = ipv4_route_flush_table; 3216 if (!net_eq(net, &init_net)) { 3217 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3218 if (!tbl) 3219 goto err_dup; 3220 3221 /* Don't export sysctls to unprivileged users */ 3222 if (net->user_ns != &init_user_ns) 3223 tbl[0].procname = NULL; 3224 } 3225 tbl[0].extra1 = net; 3226 3227 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl); 3228 if (!net->ipv4.route_hdr) 3229 goto err_reg; 3230 return 0; 3231 3232 err_reg: 3233 if (tbl != ipv4_route_flush_table) 3234 kfree(tbl); 3235 err_dup: 3236 return -ENOMEM; 3237 } 3238 3239 static __net_exit void sysctl_route_net_exit(struct net *net) 3240 { 3241 struct ctl_table *tbl; 3242 3243 tbl = net->ipv4.route_hdr->ctl_table_arg; 3244 unregister_net_sysctl_table(net->ipv4.route_hdr); 3245 BUG_ON(tbl == ipv4_route_flush_table); 3246 kfree(tbl); 3247 } 3248 3249 static __net_initdata struct pernet_operations sysctl_route_ops = { 3250 .init = sysctl_route_net_init, 3251 .exit = sysctl_route_net_exit, 3252 }; 3253 #endif 3254 3255 static __net_init int rt_genid_init(struct net *net) 3256 { 3257 atomic_set(&net->ipv4.rt_genid, 0); 3258 atomic_set(&net->fnhe_genid, 0); 3259 atomic_set(&net->ipv4.dev_addr_genid, get_random_int()); 3260 return 0; 3261 } 3262 3263 static __net_initdata struct pernet_operations rt_genid_ops = { 3264 .init = rt_genid_init, 3265 }; 3266 3267 static int __net_init ipv4_inetpeer_init(struct net *net) 3268 { 3269 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3270 3271 if (!bp) 3272 return -ENOMEM; 3273 inet_peer_base_init(bp); 3274 net->ipv4.peers = bp; 3275 return 0; 3276 } 3277 3278 static void __net_exit ipv4_inetpeer_exit(struct net *net) 3279 { 3280 struct inet_peer_base *bp = net->ipv4.peers; 3281 3282 net->ipv4.peers = NULL; 3283 inetpeer_invalidate_tree(bp); 3284 kfree(bp); 3285 } 3286 3287 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = { 3288 .init = ipv4_inetpeer_init, 3289 .exit = ipv4_inetpeer_exit, 3290 }; 3291 3292 #ifdef CONFIG_IP_ROUTE_CLASSID 3293 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3294 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3295 3296 int __init ip_rt_init(void) 3297 { 3298 int cpu; 3299 3300 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents), 3301 GFP_KERNEL); 3302 if (!ip_idents) 3303 panic("IP: failed to allocate ip_idents\n"); 3304 3305 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents)); 3306 3307 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL); 3308 if (!ip_tstamps) 3309 panic("IP: failed to allocate ip_tstamps\n"); 3310 3311 for_each_possible_cpu(cpu) { 3312 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu); 3313 3314 INIT_LIST_HEAD(&ul->head); 3315 spin_lock_init(&ul->lock); 3316 } 3317 #ifdef CONFIG_IP_ROUTE_CLASSID 3318 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3319 if (!ip_rt_acct) 3320 panic("IP: failed to allocate ip_rt_acct\n"); 3321 #endif 3322 3323 ipv4_dst_ops.kmem_cachep = 3324 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3325 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3326 3327 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3328 3329 if (dst_entries_init(&ipv4_dst_ops) < 0) 3330 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3331 3332 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3333 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3334 3335 ipv4_dst_ops.gc_thresh = ~0; 3336 ip_rt_max_size = INT_MAX; 3337 3338 devinet_init(); 3339 ip_fib_init(); 3340 3341 if (ip_rt_proc_init()) 3342 pr_err("Unable to create route proc files\n"); 3343 #ifdef CONFIG_XFRM 3344 xfrm_init(); 3345 xfrm4_init(); 3346 #endif 3347 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, 3348 RTNL_FLAG_DOIT_UNLOCKED); 3349 3350 #ifdef CONFIG_SYSCTL 3351 register_pernet_subsys(&sysctl_route_ops); 3352 #endif 3353 register_pernet_subsys(&rt_genid_ops); 3354 register_pernet_subsys(&ipv4_inetpeer_ops); 3355 return 0; 3356 } 3357 3358 #ifdef CONFIG_SYSCTL 3359 /* 3360 * We really need to sanitize the damn ipv4 init order, then all 3361 * this nonsense will go away. 3362 */ 3363 void __init ip_static_sysctl_init(void) 3364 { 3365 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table); 3366 } 3367 #endif 3368