1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * ROUTE - implementation of the IP router. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 13 * 14 * Fixes: 15 * Alan Cox : Verify area fixes. 16 * Alan Cox : cli() protects routing changes 17 * Rui Oliveira : ICMP routing table updates 18 * (rco@di.uminho.pt) Routing table insertion and update 19 * Linus Torvalds : Rewrote bits to be sensible 20 * Alan Cox : Added BSD route gw semantics 21 * Alan Cox : Super /proc >4K 22 * Alan Cox : MTU in route table 23 * Alan Cox : MSS actually. Also added the window 24 * clamper. 25 * Sam Lantinga : Fixed route matching in rt_del() 26 * Alan Cox : Routing cache support. 27 * Alan Cox : Removed compatibility cruft. 28 * Alan Cox : RTF_REJECT support. 29 * Alan Cox : TCP irtt support. 30 * Jonathan Naylor : Added Metric support. 31 * Miquel van Smoorenburg : BSD API fixes. 32 * Miquel van Smoorenburg : Metrics. 33 * Alan Cox : Use __u32 properly 34 * Alan Cox : Aligned routing errors more closely with BSD 35 * our system is still very different. 36 * Alan Cox : Faster /proc handling 37 * Alexey Kuznetsov : Massive rework to support tree based routing, 38 * routing caches and better behaviour. 39 * 40 * Olaf Erb : irtt wasn't being copied right. 41 * Bjorn Ekwall : Kerneld route support. 42 * Alan Cox : Multicast fixed (I hope) 43 * Pavel Krauz : Limited broadcast fixed 44 * Mike McLagan : Routing by source 45 * Alexey Kuznetsov : End of old history. Split to fib.c and 46 * route.c and rewritten from scratch. 47 * Andi Kleen : Load-limit warning messages. 48 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 52 * Marc Boucher : routing by fwmark 53 * Robert Olsson : Added rt_cache statistics 54 * Arnaldo C. Melo : Convert proc stuff to seq_file 55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 57 * Ilia Sotnikov : Removed TOS from hash calculations 58 * 59 * This program is free software; you can redistribute it and/or 60 * modify it under the terms of the GNU General Public License 61 * as published by the Free Software Foundation; either version 62 * 2 of the License, or (at your option) any later version. 63 */ 64 65 #include <linux/module.h> 66 #include <asm/uaccess.h> 67 #include <asm/system.h> 68 #include <linux/bitops.h> 69 #include <linux/types.h> 70 #include <linux/kernel.h> 71 #include <linux/mm.h> 72 #include <linux/bootmem.h> 73 #include <linux/string.h> 74 #include <linux/socket.h> 75 #include <linux/sockios.h> 76 #include <linux/errno.h> 77 #include <linux/in.h> 78 #include <linux/inet.h> 79 #include <linux/netdevice.h> 80 #include <linux/proc_fs.h> 81 #include <linux/init.h> 82 #include <linux/workqueue.h> 83 #include <linux/skbuff.h> 84 #include <linux/inetdevice.h> 85 #include <linux/igmp.h> 86 #include <linux/pkt_sched.h> 87 #include <linux/mroute.h> 88 #include <linux/netfilter_ipv4.h> 89 #include <linux/random.h> 90 #include <linux/jhash.h> 91 #include <linux/rcupdate.h> 92 #include <linux/times.h> 93 #include <linux/slab.h> 94 #include <net/dst.h> 95 #include <net/net_namespace.h> 96 #include <net/protocol.h> 97 #include <net/ip.h> 98 #include <net/route.h> 99 #include <net/inetpeer.h> 100 #include <net/sock.h> 101 #include <net/ip_fib.h> 102 #include <net/arp.h> 103 #include <net/tcp.h> 104 #include <net/icmp.h> 105 #include <net/xfrm.h> 106 #include <net/netevent.h> 107 #include <net/rtnetlink.h> 108 #ifdef CONFIG_SYSCTL 109 #include <linux/sysctl.h> 110 #endif 111 #include <net/secure_seq.h> 112 113 #define RT_FL_TOS(oldflp4) \ 114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) 115 116 #define IP_MAX_MTU 0xFFF0 117 118 #define RT_GC_TIMEOUT (300*HZ) 119 120 static int ip_rt_max_size; 121 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 123 static int ip_rt_redirect_number __read_mostly = 9; 124 static int ip_rt_redirect_load __read_mostly = HZ / 50; 125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 126 static int ip_rt_error_cost __read_mostly = HZ; 127 static int ip_rt_error_burst __read_mostly = 5 * HZ; 128 static int ip_rt_gc_elasticity __read_mostly = 8; 129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 131 static int ip_rt_min_advmss __read_mostly = 256; 132 static int rt_chain_length_max __read_mostly = 20; 133 static int redirect_genid; 134 135 /* 136 * Interface to generic destination cache. 137 */ 138 139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 141 static unsigned int ipv4_mtu(const struct dst_entry *dst); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 144 static void ipv4_link_failure(struct sk_buff *skb); 145 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 146 static int rt_garbage_collect(struct dst_ops *ops); 147 148 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 149 int how) 150 { 151 } 152 153 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 154 { 155 struct rtable *rt = (struct rtable *) dst; 156 struct inet_peer *peer; 157 u32 *p = NULL; 158 159 if (!rt->peer) 160 rt_bind_peer(rt, rt->rt_dst, 1); 161 162 peer = rt->peer; 163 if (peer) { 164 u32 *old_p = __DST_METRICS_PTR(old); 165 unsigned long prev, new; 166 167 p = peer->metrics; 168 if (inet_metrics_new(peer)) 169 memcpy(p, old_p, sizeof(u32) * RTAX_MAX); 170 171 new = (unsigned long) p; 172 prev = cmpxchg(&dst->_metrics, old, new); 173 174 if (prev != old) { 175 p = __DST_METRICS_PTR(prev); 176 if (prev & DST_METRICS_READ_ONLY) 177 p = NULL; 178 } else { 179 if (rt->fi) { 180 fib_info_put(rt->fi); 181 rt->fi = NULL; 182 } 183 } 184 } 185 return p; 186 } 187 188 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr); 189 190 static struct dst_ops ipv4_dst_ops = { 191 .family = AF_INET, 192 .protocol = cpu_to_be16(ETH_P_IP), 193 .gc = rt_garbage_collect, 194 .check = ipv4_dst_check, 195 .default_advmss = ipv4_default_advmss, 196 .mtu = ipv4_mtu, 197 .cow_metrics = ipv4_cow_metrics, 198 .destroy = ipv4_dst_destroy, 199 .ifdown = ipv4_dst_ifdown, 200 .negative_advice = ipv4_negative_advice, 201 .link_failure = ipv4_link_failure, 202 .update_pmtu = ip_rt_update_pmtu, 203 .local_out = __ip_local_out, 204 .neigh_lookup = ipv4_neigh_lookup, 205 }; 206 207 #define ECN_OR_COST(class) TC_PRIO_##class 208 209 const __u8 ip_tos2prio[16] = { 210 TC_PRIO_BESTEFFORT, 211 ECN_OR_COST(BESTEFFORT), 212 TC_PRIO_BESTEFFORT, 213 ECN_OR_COST(BESTEFFORT), 214 TC_PRIO_BULK, 215 ECN_OR_COST(BULK), 216 TC_PRIO_BULK, 217 ECN_OR_COST(BULK), 218 TC_PRIO_INTERACTIVE, 219 ECN_OR_COST(INTERACTIVE), 220 TC_PRIO_INTERACTIVE, 221 ECN_OR_COST(INTERACTIVE), 222 TC_PRIO_INTERACTIVE_BULK, 223 ECN_OR_COST(INTERACTIVE_BULK), 224 TC_PRIO_INTERACTIVE_BULK, 225 ECN_OR_COST(INTERACTIVE_BULK) 226 }; 227 228 229 /* 230 * Route cache. 231 */ 232 233 /* The locking scheme is rather straight forward: 234 * 235 * 1) Read-Copy Update protects the buckets of the central route hash. 236 * 2) Only writers remove entries, and they hold the lock 237 * as they look at rtable reference counts. 238 * 3) Only readers acquire references to rtable entries, 239 * they do so with atomic increments and with the 240 * lock held. 241 */ 242 243 struct rt_hash_bucket { 244 struct rtable __rcu *chain; 245 }; 246 247 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ 248 defined(CONFIG_PROVE_LOCKING) 249 /* 250 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks 251 * The size of this table is a power of two and depends on the number of CPUS. 252 * (on lockdep we have a quite big spinlock_t, so keep the size down there) 253 */ 254 #ifdef CONFIG_LOCKDEP 255 # define RT_HASH_LOCK_SZ 256 256 #else 257 # if NR_CPUS >= 32 258 # define RT_HASH_LOCK_SZ 4096 259 # elif NR_CPUS >= 16 260 # define RT_HASH_LOCK_SZ 2048 261 # elif NR_CPUS >= 8 262 # define RT_HASH_LOCK_SZ 1024 263 # elif NR_CPUS >= 4 264 # define RT_HASH_LOCK_SZ 512 265 # else 266 # define RT_HASH_LOCK_SZ 256 267 # endif 268 #endif 269 270 static spinlock_t *rt_hash_locks; 271 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)] 272 273 static __init void rt_hash_lock_init(void) 274 { 275 int i; 276 277 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, 278 GFP_KERNEL); 279 if (!rt_hash_locks) 280 panic("IP: failed to allocate rt_hash_locks\n"); 281 282 for (i = 0; i < RT_HASH_LOCK_SZ; i++) 283 spin_lock_init(&rt_hash_locks[i]); 284 } 285 #else 286 # define rt_hash_lock_addr(slot) NULL 287 288 static inline void rt_hash_lock_init(void) 289 { 290 } 291 #endif 292 293 static struct rt_hash_bucket *rt_hash_table __read_mostly; 294 static unsigned rt_hash_mask __read_mostly; 295 static unsigned int rt_hash_log __read_mostly; 296 297 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 298 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) 299 300 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, 301 int genid) 302 { 303 return jhash_3words((__force u32)daddr, (__force u32)saddr, 304 idx, genid) 305 & rt_hash_mask; 306 } 307 308 static inline int rt_genid(struct net *net) 309 { 310 return atomic_read(&net->ipv4.rt_genid); 311 } 312 313 #ifdef CONFIG_PROC_FS 314 struct rt_cache_iter_state { 315 struct seq_net_private p; 316 int bucket; 317 int genid; 318 }; 319 320 static struct rtable *rt_cache_get_first(struct seq_file *seq) 321 { 322 struct rt_cache_iter_state *st = seq->private; 323 struct rtable *r = NULL; 324 325 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { 326 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain)) 327 continue; 328 rcu_read_lock_bh(); 329 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); 330 while (r) { 331 if (dev_net(r->dst.dev) == seq_file_net(seq) && 332 r->rt_genid == st->genid) 333 return r; 334 r = rcu_dereference_bh(r->dst.rt_next); 335 } 336 rcu_read_unlock_bh(); 337 } 338 return r; 339 } 340 341 static struct rtable *__rt_cache_get_next(struct seq_file *seq, 342 struct rtable *r) 343 { 344 struct rt_cache_iter_state *st = seq->private; 345 346 r = rcu_dereference_bh(r->dst.rt_next); 347 while (!r) { 348 rcu_read_unlock_bh(); 349 do { 350 if (--st->bucket < 0) 351 return NULL; 352 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain)); 353 rcu_read_lock_bh(); 354 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); 355 } 356 return r; 357 } 358 359 static struct rtable *rt_cache_get_next(struct seq_file *seq, 360 struct rtable *r) 361 { 362 struct rt_cache_iter_state *st = seq->private; 363 while ((r = __rt_cache_get_next(seq, r)) != NULL) { 364 if (dev_net(r->dst.dev) != seq_file_net(seq)) 365 continue; 366 if (r->rt_genid == st->genid) 367 break; 368 } 369 return r; 370 } 371 372 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos) 373 { 374 struct rtable *r = rt_cache_get_first(seq); 375 376 if (r) 377 while (pos && (r = rt_cache_get_next(seq, r))) 378 --pos; 379 return pos ? NULL : r; 380 } 381 382 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 383 { 384 struct rt_cache_iter_state *st = seq->private; 385 if (*pos) 386 return rt_cache_get_idx(seq, *pos - 1); 387 st->genid = rt_genid(seq_file_net(seq)); 388 return SEQ_START_TOKEN; 389 } 390 391 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 392 { 393 struct rtable *r; 394 395 if (v == SEQ_START_TOKEN) 396 r = rt_cache_get_first(seq); 397 else 398 r = rt_cache_get_next(seq, v); 399 ++*pos; 400 return r; 401 } 402 403 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 404 { 405 if (v && v != SEQ_START_TOKEN) 406 rcu_read_unlock_bh(); 407 } 408 409 static int rt_cache_seq_show(struct seq_file *seq, void *v) 410 { 411 if (v == SEQ_START_TOKEN) 412 seq_printf(seq, "%-127s\n", 413 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 414 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 415 "HHUptod\tSpecDst"); 416 else { 417 struct rtable *r = v; 418 struct neighbour *n; 419 int len, HHUptod; 420 421 rcu_read_lock(); 422 n = dst_get_neighbour_noref(&r->dst); 423 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0; 424 rcu_read_unlock(); 425 426 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" 427 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", 428 r->dst.dev ? r->dst.dev->name : "*", 429 (__force u32)r->rt_dst, 430 (__force u32)r->rt_gateway, 431 r->rt_flags, atomic_read(&r->dst.__refcnt), 432 r->dst.__use, 0, (__force u32)r->rt_src, 433 dst_metric_advmss(&r->dst) + 40, 434 dst_metric(&r->dst, RTAX_WINDOW), 435 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) + 436 dst_metric(&r->dst, RTAX_RTTVAR)), 437 r->rt_key_tos, 438 -1, 439 HHUptod, 440 r->rt_spec_dst, &len); 441 442 seq_printf(seq, "%*s\n", 127 - len, ""); 443 } 444 return 0; 445 } 446 447 static const struct seq_operations rt_cache_seq_ops = { 448 .start = rt_cache_seq_start, 449 .next = rt_cache_seq_next, 450 .stop = rt_cache_seq_stop, 451 .show = rt_cache_seq_show, 452 }; 453 454 static int rt_cache_seq_open(struct inode *inode, struct file *file) 455 { 456 return seq_open_net(inode, file, &rt_cache_seq_ops, 457 sizeof(struct rt_cache_iter_state)); 458 } 459 460 static const struct file_operations rt_cache_seq_fops = { 461 .owner = THIS_MODULE, 462 .open = rt_cache_seq_open, 463 .read = seq_read, 464 .llseek = seq_lseek, 465 .release = seq_release_net, 466 }; 467 468 469 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 470 { 471 int cpu; 472 473 if (*pos == 0) 474 return SEQ_START_TOKEN; 475 476 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 477 if (!cpu_possible(cpu)) 478 continue; 479 *pos = cpu+1; 480 return &per_cpu(rt_cache_stat, cpu); 481 } 482 return NULL; 483 } 484 485 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 486 { 487 int cpu; 488 489 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 490 if (!cpu_possible(cpu)) 491 continue; 492 *pos = cpu+1; 493 return &per_cpu(rt_cache_stat, cpu); 494 } 495 return NULL; 496 497 } 498 499 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 500 { 501 502 } 503 504 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 505 { 506 struct rt_cache_stat *st = v; 507 508 if (v == SEQ_START_TOKEN) { 509 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"); 510 return 0; 511 } 512 513 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 514 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 515 dst_entries_get_slow(&ipv4_dst_ops), 516 st->in_hit, 517 st->in_slow_tot, 518 st->in_slow_mc, 519 st->in_no_route, 520 st->in_brd, 521 st->in_martian_dst, 522 st->in_martian_src, 523 524 st->out_hit, 525 st->out_slow_tot, 526 st->out_slow_mc, 527 528 st->gc_total, 529 st->gc_ignored, 530 st->gc_goal_miss, 531 st->gc_dst_overflow, 532 st->in_hlist_search, 533 st->out_hlist_search 534 ); 535 return 0; 536 } 537 538 static const struct seq_operations rt_cpu_seq_ops = { 539 .start = rt_cpu_seq_start, 540 .next = rt_cpu_seq_next, 541 .stop = rt_cpu_seq_stop, 542 .show = rt_cpu_seq_show, 543 }; 544 545 546 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 547 { 548 return seq_open(file, &rt_cpu_seq_ops); 549 } 550 551 static const struct file_operations rt_cpu_seq_fops = { 552 .owner = THIS_MODULE, 553 .open = rt_cpu_seq_open, 554 .read = seq_read, 555 .llseek = seq_lseek, 556 .release = seq_release, 557 }; 558 559 #ifdef CONFIG_IP_ROUTE_CLASSID 560 static int rt_acct_proc_show(struct seq_file *m, void *v) 561 { 562 struct ip_rt_acct *dst, *src; 563 unsigned int i, j; 564 565 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 566 if (!dst) 567 return -ENOMEM; 568 569 for_each_possible_cpu(i) { 570 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 571 for (j = 0; j < 256; j++) { 572 dst[j].o_bytes += src[j].o_bytes; 573 dst[j].o_packets += src[j].o_packets; 574 dst[j].i_bytes += src[j].i_bytes; 575 dst[j].i_packets += src[j].i_packets; 576 } 577 } 578 579 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 580 kfree(dst); 581 return 0; 582 } 583 584 static int rt_acct_proc_open(struct inode *inode, struct file *file) 585 { 586 return single_open(file, rt_acct_proc_show, NULL); 587 } 588 589 static const struct file_operations rt_acct_proc_fops = { 590 .owner = THIS_MODULE, 591 .open = rt_acct_proc_open, 592 .read = seq_read, 593 .llseek = seq_lseek, 594 .release = single_release, 595 }; 596 #endif 597 598 static int __net_init ip_rt_do_proc_init(struct net *net) 599 { 600 struct proc_dir_entry *pde; 601 602 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO, 603 &rt_cache_seq_fops); 604 if (!pde) 605 goto err1; 606 607 pde = proc_create("rt_cache", S_IRUGO, 608 net->proc_net_stat, &rt_cpu_seq_fops); 609 if (!pde) 610 goto err2; 611 612 #ifdef CONFIG_IP_ROUTE_CLASSID 613 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 614 if (!pde) 615 goto err3; 616 #endif 617 return 0; 618 619 #ifdef CONFIG_IP_ROUTE_CLASSID 620 err3: 621 remove_proc_entry("rt_cache", net->proc_net_stat); 622 #endif 623 err2: 624 remove_proc_entry("rt_cache", net->proc_net); 625 err1: 626 return -ENOMEM; 627 } 628 629 static void __net_exit ip_rt_do_proc_exit(struct net *net) 630 { 631 remove_proc_entry("rt_cache", net->proc_net_stat); 632 remove_proc_entry("rt_cache", net->proc_net); 633 #ifdef CONFIG_IP_ROUTE_CLASSID 634 remove_proc_entry("rt_acct", net->proc_net); 635 #endif 636 } 637 638 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 639 .init = ip_rt_do_proc_init, 640 .exit = ip_rt_do_proc_exit, 641 }; 642 643 static int __init ip_rt_proc_init(void) 644 { 645 return register_pernet_subsys(&ip_rt_proc_ops); 646 } 647 648 #else 649 static inline int ip_rt_proc_init(void) 650 { 651 return 0; 652 } 653 #endif /* CONFIG_PROC_FS */ 654 655 static inline void rt_free(struct rtable *rt) 656 { 657 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 658 } 659 660 static inline void rt_drop(struct rtable *rt) 661 { 662 ip_rt_put(rt); 663 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 664 } 665 666 static inline int rt_fast_clean(struct rtable *rth) 667 { 668 /* Kill broadcast/multicast entries very aggresively, if they 669 collide in hash table with more useful entries */ 670 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) && 671 rt_is_input_route(rth) && rth->dst.rt_next; 672 } 673 674 static inline int rt_valuable(struct rtable *rth) 675 { 676 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || 677 (rth->peer && rth->peer->pmtu_expires); 678 } 679 680 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2) 681 { 682 unsigned long age; 683 int ret = 0; 684 685 if (atomic_read(&rth->dst.__refcnt)) 686 goto out; 687 688 age = jiffies - rth->dst.lastuse; 689 if ((age <= tmo1 && !rt_fast_clean(rth)) || 690 (age <= tmo2 && rt_valuable(rth))) 691 goto out; 692 ret = 1; 693 out: return ret; 694 } 695 696 /* Bits of score are: 697 * 31: very valuable 698 * 30: not quite useless 699 * 29..0: usage counter 700 */ 701 static inline u32 rt_score(struct rtable *rt) 702 { 703 u32 score = jiffies - rt->dst.lastuse; 704 705 score = ~score & ~(3<<30); 706 707 if (rt_valuable(rt)) 708 score |= (1<<31); 709 710 if (rt_is_output_route(rt) || 711 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) 712 score |= (1<<30); 713 714 return score; 715 } 716 717 static inline bool rt_caching(const struct net *net) 718 { 719 return net->ipv4.current_rt_cache_rebuild_count <= 720 net->ipv4.sysctl_rt_cache_rebuild_count; 721 } 722 723 static inline bool compare_hash_inputs(const struct rtable *rt1, 724 const struct rtable *rt2) 725 { 726 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | 727 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | 728 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0); 729 } 730 731 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2) 732 { 733 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | 734 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | 735 (rt1->rt_mark ^ rt2->rt_mark) | 736 (rt1->rt_key_tos ^ rt2->rt_key_tos) | 737 (rt1->rt_route_iif ^ rt2->rt_route_iif) | 738 (rt1->rt_oif ^ rt2->rt_oif)) == 0; 739 } 740 741 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) 742 { 743 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev)); 744 } 745 746 static inline int rt_is_expired(struct rtable *rth) 747 { 748 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); 749 } 750 751 /* 752 * Perform a full scan of hash table and free all entries. 753 * Can be called by a softirq or a process. 754 * In the later case, we want to be reschedule if necessary 755 */ 756 static void rt_do_flush(struct net *net, int process_context) 757 { 758 unsigned int i; 759 struct rtable *rth, *next; 760 761 for (i = 0; i <= rt_hash_mask; i++) { 762 struct rtable __rcu **pprev; 763 struct rtable *list; 764 765 if (process_context && need_resched()) 766 cond_resched(); 767 rth = rcu_access_pointer(rt_hash_table[i].chain); 768 if (!rth) 769 continue; 770 771 spin_lock_bh(rt_hash_lock_addr(i)); 772 773 list = NULL; 774 pprev = &rt_hash_table[i].chain; 775 rth = rcu_dereference_protected(*pprev, 776 lockdep_is_held(rt_hash_lock_addr(i))); 777 778 while (rth) { 779 next = rcu_dereference_protected(rth->dst.rt_next, 780 lockdep_is_held(rt_hash_lock_addr(i))); 781 782 if (!net || 783 net_eq(dev_net(rth->dst.dev), net)) { 784 rcu_assign_pointer(*pprev, next); 785 rcu_assign_pointer(rth->dst.rt_next, list); 786 list = rth; 787 } else { 788 pprev = &rth->dst.rt_next; 789 } 790 rth = next; 791 } 792 793 spin_unlock_bh(rt_hash_lock_addr(i)); 794 795 for (; list; list = next) { 796 next = rcu_dereference_protected(list->dst.rt_next, 1); 797 rt_free(list); 798 } 799 } 800 } 801 802 /* 803 * While freeing expired entries, we compute average chain length 804 * and standard deviation, using fixed-point arithmetic. 805 * This to have an estimation of rt_chain_length_max 806 * rt_chain_length_max = max(elasticity, AVG + 4*SD) 807 * We use 3 bits for frational part, and 29 (or 61) for magnitude. 808 */ 809 810 #define FRACT_BITS 3 811 #define ONE (1UL << FRACT_BITS) 812 813 /* 814 * Given a hash chain and an item in this hash chain, 815 * find if a previous entry has the same hash_inputs 816 * (but differs on tos, mark or oif) 817 * Returns 0 if an alias is found. 818 * Returns ONE if rth has no alias before itself. 819 */ 820 static int has_noalias(const struct rtable *head, const struct rtable *rth) 821 { 822 const struct rtable *aux = head; 823 824 while (aux != rth) { 825 if (compare_hash_inputs(aux, rth)) 826 return 0; 827 aux = rcu_dereference_protected(aux->dst.rt_next, 1); 828 } 829 return ONE; 830 } 831 832 /* 833 * Perturbation of rt_genid by a small quantity [1..256] 834 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() 835 * many times (2^24) without giving recent rt_genid. 836 * Jenkins hash is strong enough that litle changes of rt_genid are OK. 837 */ 838 static void rt_cache_invalidate(struct net *net) 839 { 840 unsigned char shuffle; 841 842 get_random_bytes(&shuffle, sizeof(shuffle)); 843 atomic_add(shuffle + 1U, &net->ipv4.rt_genid); 844 redirect_genid++; 845 } 846 847 /* 848 * delay < 0 : invalidate cache (fast : entries will be deleted later) 849 * delay >= 0 : invalidate & flush cache (can be long) 850 */ 851 void rt_cache_flush(struct net *net, int delay) 852 { 853 rt_cache_invalidate(net); 854 if (delay >= 0) 855 rt_do_flush(net, !in_softirq()); 856 } 857 858 /* Flush previous cache invalidated entries from the cache */ 859 void rt_cache_flush_batch(struct net *net) 860 { 861 rt_do_flush(net, !in_softirq()); 862 } 863 864 static void rt_emergency_hash_rebuild(struct net *net) 865 { 866 if (net_ratelimit()) 867 printk(KERN_WARNING "Route hash chain too long!\n"); 868 rt_cache_invalidate(net); 869 } 870 871 /* 872 Short description of GC goals. 873 874 We want to build algorithm, which will keep routing cache 875 at some equilibrium point, when number of aged off entries 876 is kept approximately equal to newly generated ones. 877 878 Current expiration strength is variable "expire". 879 We try to adjust it dynamically, so that if networking 880 is idle expires is large enough to keep enough of warm entries, 881 and when load increases it reduces to limit cache size. 882 */ 883 884 static int rt_garbage_collect(struct dst_ops *ops) 885 { 886 static unsigned long expire = RT_GC_TIMEOUT; 887 static unsigned long last_gc; 888 static int rover; 889 static int equilibrium; 890 struct rtable *rth; 891 struct rtable __rcu **rthp; 892 unsigned long now = jiffies; 893 int goal; 894 int entries = dst_entries_get_fast(&ipv4_dst_ops); 895 896 /* 897 * Garbage collection is pretty expensive, 898 * do not make it too frequently. 899 */ 900 901 RT_CACHE_STAT_INC(gc_total); 902 903 if (now - last_gc < ip_rt_gc_min_interval && 904 entries < ip_rt_max_size) { 905 RT_CACHE_STAT_INC(gc_ignored); 906 goto out; 907 } 908 909 entries = dst_entries_get_slow(&ipv4_dst_ops); 910 /* Calculate number of entries, which we want to expire now. */ 911 goal = entries - (ip_rt_gc_elasticity << rt_hash_log); 912 if (goal <= 0) { 913 if (equilibrium < ipv4_dst_ops.gc_thresh) 914 equilibrium = ipv4_dst_ops.gc_thresh; 915 goal = entries - equilibrium; 916 if (goal > 0) { 917 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); 918 goal = entries - equilibrium; 919 } 920 } else { 921 /* We are in dangerous area. Try to reduce cache really 922 * aggressively. 923 */ 924 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1); 925 equilibrium = entries - goal; 926 } 927 928 if (now - last_gc >= ip_rt_gc_min_interval) 929 last_gc = now; 930 931 if (goal <= 0) { 932 equilibrium += goal; 933 goto work_done; 934 } 935 936 do { 937 int i, k; 938 939 for (i = rt_hash_mask, k = rover; i >= 0; i--) { 940 unsigned long tmo = expire; 941 942 k = (k + 1) & rt_hash_mask; 943 rthp = &rt_hash_table[k].chain; 944 spin_lock_bh(rt_hash_lock_addr(k)); 945 while ((rth = rcu_dereference_protected(*rthp, 946 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) { 947 if (!rt_is_expired(rth) && 948 !rt_may_expire(rth, tmo, expire)) { 949 tmo >>= 1; 950 rthp = &rth->dst.rt_next; 951 continue; 952 } 953 *rthp = rth->dst.rt_next; 954 rt_free(rth); 955 goal--; 956 } 957 spin_unlock_bh(rt_hash_lock_addr(k)); 958 if (goal <= 0) 959 break; 960 } 961 rover = k; 962 963 if (goal <= 0) 964 goto work_done; 965 966 /* Goal is not achieved. We stop process if: 967 968 - if expire reduced to zero. Otherwise, expire is halfed. 969 - if table is not full. 970 - if we are called from interrupt. 971 - jiffies check is just fallback/debug loop breaker. 972 We will not spin here for long time in any case. 973 */ 974 975 RT_CACHE_STAT_INC(gc_goal_miss); 976 977 if (expire == 0) 978 break; 979 980 expire >>= 1; 981 982 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) 983 goto out; 984 } while (!in_softirq() && time_before_eq(jiffies, now)); 985 986 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) 987 goto out; 988 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size) 989 goto out; 990 if (net_ratelimit()) 991 printk(KERN_WARNING "dst cache overflow\n"); 992 RT_CACHE_STAT_INC(gc_dst_overflow); 993 return 1; 994 995 work_done: 996 expire += ip_rt_gc_min_interval; 997 if (expire > ip_rt_gc_timeout || 998 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh || 999 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh) 1000 expire = ip_rt_gc_timeout; 1001 out: return 0; 1002 } 1003 1004 /* 1005 * Returns number of entries in a hash chain that have different hash_inputs 1006 */ 1007 static int slow_chain_length(const struct rtable *head) 1008 { 1009 int length = 0; 1010 const struct rtable *rth = head; 1011 1012 while (rth) { 1013 length += has_noalias(head, rth); 1014 rth = rcu_dereference_protected(rth->dst.rt_next, 1); 1015 } 1016 return length >> FRACT_BITS; 1017 } 1018 1019 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr) 1020 { 1021 static const __be32 inaddr_any = 0; 1022 struct net_device *dev = dst->dev; 1023 const __be32 *pkey = daddr; 1024 struct neighbour *n; 1025 1026 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) 1027 pkey = &inaddr_any; 1028 1029 n = __ipv4_neigh_lookup(&arp_tbl, dev, *(__force u32 *)pkey); 1030 if (n) 1031 return n; 1032 return neigh_create(&arp_tbl, pkey, dev); 1033 } 1034 1035 static int rt_bind_neighbour(struct rtable *rt) 1036 { 1037 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway); 1038 if (IS_ERR(n)) 1039 return PTR_ERR(n); 1040 dst_set_neighbour(&rt->dst, n); 1041 1042 return 0; 1043 } 1044 1045 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt, 1046 struct sk_buff *skb, int ifindex) 1047 { 1048 struct rtable *rth, *cand; 1049 struct rtable __rcu **rthp, **candp; 1050 unsigned long now; 1051 u32 min_score; 1052 int chain_length; 1053 int attempts = !in_softirq(); 1054 1055 restart: 1056 chain_length = 0; 1057 min_score = ~(u32)0; 1058 cand = NULL; 1059 candp = NULL; 1060 now = jiffies; 1061 1062 if (!rt_caching(dev_net(rt->dst.dev))) { 1063 /* 1064 * If we're not caching, just tell the caller we 1065 * were successful and don't touch the route. The 1066 * caller hold the sole reference to the cache entry, and 1067 * it will be released when the caller is done with it. 1068 * If we drop it here, the callers have no way to resolve routes 1069 * when we're not caching. Instead, just point *rp at rt, so 1070 * the caller gets a single use out of the route 1071 * Note that we do rt_free on this new route entry, so that 1072 * once its refcount hits zero, we are still able to reap it 1073 * (Thanks Alexey) 1074 * Note: To avoid expensive rcu stuff for this uncached dst, 1075 * we set DST_NOCACHE so that dst_release() can free dst without 1076 * waiting a grace period. 1077 */ 1078 1079 rt->dst.flags |= DST_NOCACHE; 1080 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { 1081 int err = rt_bind_neighbour(rt); 1082 if (err) { 1083 if (net_ratelimit()) 1084 printk(KERN_WARNING 1085 "Neighbour table failure & not caching routes.\n"); 1086 ip_rt_put(rt); 1087 return ERR_PTR(err); 1088 } 1089 } 1090 1091 goto skip_hashing; 1092 } 1093 1094 rthp = &rt_hash_table[hash].chain; 1095 1096 spin_lock_bh(rt_hash_lock_addr(hash)); 1097 while ((rth = rcu_dereference_protected(*rthp, 1098 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { 1099 if (rt_is_expired(rth)) { 1100 *rthp = rth->dst.rt_next; 1101 rt_free(rth); 1102 continue; 1103 } 1104 if (compare_keys(rth, rt) && compare_netns(rth, rt)) { 1105 /* Put it first */ 1106 *rthp = rth->dst.rt_next; 1107 /* 1108 * Since lookup is lockfree, the deletion 1109 * must be visible to another weakly ordered CPU before 1110 * the insertion at the start of the hash chain. 1111 */ 1112 rcu_assign_pointer(rth->dst.rt_next, 1113 rt_hash_table[hash].chain); 1114 /* 1115 * Since lookup is lockfree, the update writes 1116 * must be ordered for consistency on SMP. 1117 */ 1118 rcu_assign_pointer(rt_hash_table[hash].chain, rth); 1119 1120 dst_use(&rth->dst, now); 1121 spin_unlock_bh(rt_hash_lock_addr(hash)); 1122 1123 rt_drop(rt); 1124 if (skb) 1125 skb_dst_set(skb, &rth->dst); 1126 return rth; 1127 } 1128 1129 if (!atomic_read(&rth->dst.__refcnt)) { 1130 u32 score = rt_score(rth); 1131 1132 if (score <= min_score) { 1133 cand = rth; 1134 candp = rthp; 1135 min_score = score; 1136 } 1137 } 1138 1139 chain_length++; 1140 1141 rthp = &rth->dst.rt_next; 1142 } 1143 1144 if (cand) { 1145 /* ip_rt_gc_elasticity used to be average length of chain 1146 * length, when exceeded gc becomes really aggressive. 1147 * 1148 * The second limit is less certain. At the moment it allows 1149 * only 2 entries per bucket. We will see. 1150 */ 1151 if (chain_length > ip_rt_gc_elasticity) { 1152 *candp = cand->dst.rt_next; 1153 rt_free(cand); 1154 } 1155 } else { 1156 if (chain_length > rt_chain_length_max && 1157 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) { 1158 struct net *net = dev_net(rt->dst.dev); 1159 int num = ++net->ipv4.current_rt_cache_rebuild_count; 1160 if (!rt_caching(net)) { 1161 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n", 1162 rt->dst.dev->name, num); 1163 } 1164 rt_emergency_hash_rebuild(net); 1165 spin_unlock_bh(rt_hash_lock_addr(hash)); 1166 1167 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1168 ifindex, rt_genid(net)); 1169 goto restart; 1170 } 1171 } 1172 1173 /* Try to bind route to arp only if it is output 1174 route or unicast forwarding path. 1175 */ 1176 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { 1177 int err = rt_bind_neighbour(rt); 1178 if (err) { 1179 spin_unlock_bh(rt_hash_lock_addr(hash)); 1180 1181 if (err != -ENOBUFS) { 1182 rt_drop(rt); 1183 return ERR_PTR(err); 1184 } 1185 1186 /* Neighbour tables are full and nothing 1187 can be released. Try to shrink route cache, 1188 it is most likely it holds some neighbour records. 1189 */ 1190 if (attempts-- > 0) { 1191 int saved_elasticity = ip_rt_gc_elasticity; 1192 int saved_int = ip_rt_gc_min_interval; 1193 ip_rt_gc_elasticity = 1; 1194 ip_rt_gc_min_interval = 0; 1195 rt_garbage_collect(&ipv4_dst_ops); 1196 ip_rt_gc_min_interval = saved_int; 1197 ip_rt_gc_elasticity = saved_elasticity; 1198 goto restart; 1199 } 1200 1201 if (net_ratelimit()) 1202 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n"); 1203 rt_drop(rt); 1204 return ERR_PTR(-ENOBUFS); 1205 } 1206 } 1207 1208 rt->dst.rt_next = rt_hash_table[hash].chain; 1209 1210 /* 1211 * Since lookup is lockfree, we must make sure 1212 * previous writes to rt are committed to memory 1213 * before making rt visible to other CPUS. 1214 */ 1215 rcu_assign_pointer(rt_hash_table[hash].chain, rt); 1216 1217 spin_unlock_bh(rt_hash_lock_addr(hash)); 1218 1219 skip_hashing: 1220 if (skb) 1221 skb_dst_set(skb, &rt->dst); 1222 return rt; 1223 } 1224 1225 static atomic_t __rt_peer_genid = ATOMIC_INIT(0); 1226 1227 static u32 rt_peer_genid(void) 1228 { 1229 return atomic_read(&__rt_peer_genid); 1230 } 1231 1232 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create) 1233 { 1234 struct inet_peer *peer; 1235 1236 peer = inet_getpeer_v4(daddr, create); 1237 1238 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL) 1239 inet_putpeer(peer); 1240 else 1241 rt->rt_peer_genid = rt_peer_genid(); 1242 } 1243 1244 /* 1245 * Peer allocation may fail only in serious out-of-memory conditions. However 1246 * we still can generate some output. 1247 * Random ID selection looks a bit dangerous because we have no chances to 1248 * select ID being unique in a reasonable period of time. 1249 * But broken packet identifier may be better than no packet at all. 1250 */ 1251 static void ip_select_fb_ident(struct iphdr *iph) 1252 { 1253 static DEFINE_SPINLOCK(ip_fb_id_lock); 1254 static u32 ip_fallback_id; 1255 u32 salt; 1256 1257 spin_lock_bh(&ip_fb_id_lock); 1258 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); 1259 iph->id = htons(salt & 0xFFFF); 1260 ip_fallback_id = salt; 1261 spin_unlock_bh(&ip_fb_id_lock); 1262 } 1263 1264 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) 1265 { 1266 struct rtable *rt = (struct rtable *) dst; 1267 1268 if (rt) { 1269 if (rt->peer == NULL) 1270 rt_bind_peer(rt, rt->rt_dst, 1); 1271 1272 /* If peer is attached to destination, it is never detached, 1273 so that we need not to grab a lock to dereference it. 1274 */ 1275 if (rt->peer) { 1276 iph->id = htons(inet_getid(rt->peer, more)); 1277 return; 1278 } 1279 } else 1280 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", 1281 __builtin_return_address(0)); 1282 1283 ip_select_fb_ident(iph); 1284 } 1285 EXPORT_SYMBOL(__ip_select_ident); 1286 1287 static void rt_del(unsigned hash, struct rtable *rt) 1288 { 1289 struct rtable __rcu **rthp; 1290 struct rtable *aux; 1291 1292 rthp = &rt_hash_table[hash].chain; 1293 spin_lock_bh(rt_hash_lock_addr(hash)); 1294 ip_rt_put(rt); 1295 while ((aux = rcu_dereference_protected(*rthp, 1296 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { 1297 if (aux == rt || rt_is_expired(aux)) { 1298 *rthp = aux->dst.rt_next; 1299 rt_free(aux); 1300 continue; 1301 } 1302 rthp = &aux->dst.rt_next; 1303 } 1304 spin_unlock_bh(rt_hash_lock_addr(hash)); 1305 } 1306 1307 static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) 1308 { 1309 struct rtable *rt = (struct rtable *) dst; 1310 __be32 orig_gw = rt->rt_gateway; 1311 struct neighbour *n, *old_n; 1312 1313 dst_confirm(&rt->dst); 1314 1315 rt->rt_gateway = peer->redirect_learned.a4; 1316 1317 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway); 1318 if (IS_ERR(n)) { 1319 rt->rt_gateway = orig_gw; 1320 return; 1321 } 1322 old_n = xchg(&rt->dst._neighbour, n); 1323 if (old_n) 1324 neigh_release(old_n); 1325 if (!(n->nud_state & NUD_VALID)) { 1326 neigh_event_send(n, NULL); 1327 } else { 1328 rt->rt_flags |= RTCF_REDIRECTED; 1329 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n); 1330 } 1331 } 1332 1333 /* called in rcu_read_lock() section */ 1334 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 1335 __be32 saddr, struct net_device *dev) 1336 { 1337 int s, i; 1338 struct in_device *in_dev = __in_dev_get_rcu(dev); 1339 __be32 skeys[2] = { saddr, 0 }; 1340 int ikeys[2] = { dev->ifindex, 0 }; 1341 struct inet_peer *peer; 1342 struct net *net; 1343 1344 if (!in_dev) 1345 return; 1346 1347 net = dev_net(dev); 1348 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 1349 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 1350 ipv4_is_zeronet(new_gw)) 1351 goto reject_redirect; 1352 1353 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 1354 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 1355 goto reject_redirect; 1356 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 1357 goto reject_redirect; 1358 } else { 1359 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 1360 goto reject_redirect; 1361 } 1362 1363 for (s = 0; s < 2; s++) { 1364 for (i = 0; i < 2; i++) { 1365 unsigned int hash; 1366 struct rtable __rcu **rthp; 1367 struct rtable *rt; 1368 1369 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net)); 1370 1371 rthp = &rt_hash_table[hash].chain; 1372 1373 while ((rt = rcu_dereference(*rthp)) != NULL) { 1374 rthp = &rt->dst.rt_next; 1375 1376 if (rt->rt_key_dst != daddr || 1377 rt->rt_key_src != skeys[s] || 1378 rt->rt_oif != ikeys[i] || 1379 rt_is_input_route(rt) || 1380 rt_is_expired(rt) || 1381 !net_eq(dev_net(rt->dst.dev), net) || 1382 rt->dst.error || 1383 rt->dst.dev != dev || 1384 rt->rt_gateway != old_gw) 1385 continue; 1386 1387 if (!rt->peer) 1388 rt_bind_peer(rt, rt->rt_dst, 1); 1389 1390 peer = rt->peer; 1391 if (peer) { 1392 if (peer->redirect_learned.a4 != new_gw || 1393 peer->redirect_genid != redirect_genid) { 1394 peer->redirect_learned.a4 = new_gw; 1395 peer->redirect_genid = redirect_genid; 1396 atomic_inc(&__rt_peer_genid); 1397 } 1398 check_peer_redir(&rt->dst, peer); 1399 } 1400 } 1401 } 1402 } 1403 return; 1404 1405 reject_redirect: 1406 #ifdef CONFIG_IP_ROUTE_VERBOSE 1407 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 1408 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n" 1409 " Advised path = %pI4 -> %pI4\n", 1410 &old_gw, dev->name, &new_gw, 1411 &saddr, &daddr); 1412 #endif 1413 ; 1414 } 1415 1416 static bool peer_pmtu_expired(struct inet_peer *peer) 1417 { 1418 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); 1419 1420 return orig && 1421 time_after_eq(jiffies, orig) && 1422 cmpxchg(&peer->pmtu_expires, orig, 0) == orig; 1423 } 1424 1425 static bool peer_pmtu_cleaned(struct inet_peer *peer) 1426 { 1427 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); 1428 1429 return orig && 1430 cmpxchg(&peer->pmtu_expires, orig, 0) == orig; 1431 } 1432 1433 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 1434 { 1435 struct rtable *rt = (struct rtable *)dst; 1436 struct dst_entry *ret = dst; 1437 1438 if (rt) { 1439 if (dst->obsolete > 0) { 1440 ip_rt_put(rt); 1441 ret = NULL; 1442 } else if (rt->rt_flags & RTCF_REDIRECTED) { 1443 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1444 rt->rt_oif, 1445 rt_genid(dev_net(dst->dev))); 1446 rt_del(hash, rt); 1447 ret = NULL; 1448 } else if (rt->peer && peer_pmtu_expired(rt->peer)) { 1449 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig); 1450 } 1451 } 1452 return ret; 1453 } 1454 1455 /* 1456 * Algorithm: 1457 * 1. The first ip_rt_redirect_number redirects are sent 1458 * with exponential backoff, then we stop sending them at all, 1459 * assuming that the host ignores our redirects. 1460 * 2. If we did not see packets requiring redirects 1461 * during ip_rt_redirect_silence, we assume that the host 1462 * forgot redirected route and start to send redirects again. 1463 * 1464 * This algorithm is much cheaper and more intelligent than dumb load limiting 1465 * in icmp.c. 1466 * 1467 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 1468 * and "frag. need" (breaks PMTU discovery) in icmp.c. 1469 */ 1470 1471 void ip_rt_send_redirect(struct sk_buff *skb) 1472 { 1473 struct rtable *rt = skb_rtable(skb); 1474 struct in_device *in_dev; 1475 struct inet_peer *peer; 1476 int log_martians; 1477 1478 rcu_read_lock(); 1479 in_dev = __in_dev_get_rcu(rt->dst.dev); 1480 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 1481 rcu_read_unlock(); 1482 return; 1483 } 1484 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 1485 rcu_read_unlock(); 1486 1487 if (!rt->peer) 1488 rt_bind_peer(rt, rt->rt_dst, 1); 1489 peer = rt->peer; 1490 if (!peer) { 1491 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1492 return; 1493 } 1494 1495 /* No redirected packets during ip_rt_redirect_silence; 1496 * reset the algorithm. 1497 */ 1498 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 1499 peer->rate_tokens = 0; 1500 1501 /* Too many ignored redirects; do not send anything 1502 * set dst.rate_last to the last seen redirected packet. 1503 */ 1504 if (peer->rate_tokens >= ip_rt_redirect_number) { 1505 peer->rate_last = jiffies; 1506 return; 1507 } 1508 1509 /* Check for load limit; set rate_last to the latest sent 1510 * redirect. 1511 */ 1512 if (peer->rate_tokens == 0 || 1513 time_after(jiffies, 1514 (peer->rate_last + 1515 (ip_rt_redirect_load << peer->rate_tokens)))) { 1516 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1517 peer->rate_last = jiffies; 1518 ++peer->rate_tokens; 1519 #ifdef CONFIG_IP_ROUTE_VERBOSE 1520 if (log_martians && 1521 peer->rate_tokens == ip_rt_redirect_number && 1522 net_ratelimit()) 1523 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", 1524 &ip_hdr(skb)->saddr, rt->rt_iif, 1525 &rt->rt_dst, &rt->rt_gateway); 1526 #endif 1527 } 1528 } 1529 1530 static int ip_error(struct sk_buff *skb) 1531 { 1532 struct rtable *rt = skb_rtable(skb); 1533 struct inet_peer *peer; 1534 unsigned long now; 1535 bool send; 1536 int code; 1537 1538 switch (rt->dst.error) { 1539 case EINVAL: 1540 default: 1541 goto out; 1542 case EHOSTUNREACH: 1543 code = ICMP_HOST_UNREACH; 1544 break; 1545 case ENETUNREACH: 1546 code = ICMP_NET_UNREACH; 1547 IP_INC_STATS_BH(dev_net(rt->dst.dev), 1548 IPSTATS_MIB_INNOROUTES); 1549 break; 1550 case EACCES: 1551 code = ICMP_PKT_FILTERED; 1552 break; 1553 } 1554 1555 if (!rt->peer) 1556 rt_bind_peer(rt, rt->rt_dst, 1); 1557 peer = rt->peer; 1558 1559 send = true; 1560 if (peer) { 1561 now = jiffies; 1562 peer->rate_tokens += now - peer->rate_last; 1563 if (peer->rate_tokens > ip_rt_error_burst) 1564 peer->rate_tokens = ip_rt_error_burst; 1565 peer->rate_last = now; 1566 if (peer->rate_tokens >= ip_rt_error_cost) 1567 peer->rate_tokens -= ip_rt_error_cost; 1568 else 1569 send = false; 1570 } 1571 if (send) 1572 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1573 1574 out: kfree_skb(skb); 1575 return 0; 1576 } 1577 1578 /* 1579 * The last two values are not from the RFC but 1580 * are needed for AMPRnet AX.25 paths. 1581 */ 1582 1583 static const unsigned short mtu_plateau[] = 1584 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 }; 1585 1586 static inline unsigned short guess_mtu(unsigned short old_mtu) 1587 { 1588 int i; 1589 1590 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++) 1591 if (old_mtu > mtu_plateau[i]) 1592 return mtu_plateau[i]; 1593 return 68; 1594 } 1595 1596 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, 1597 unsigned short new_mtu, 1598 struct net_device *dev) 1599 { 1600 unsigned short old_mtu = ntohs(iph->tot_len); 1601 unsigned short est_mtu = 0; 1602 struct inet_peer *peer; 1603 1604 peer = inet_getpeer_v4(iph->daddr, 1); 1605 if (peer) { 1606 unsigned short mtu = new_mtu; 1607 1608 if (new_mtu < 68 || new_mtu >= old_mtu) { 1609 /* BSD 4.2 derived systems incorrectly adjust 1610 * tot_len by the IP header length, and report 1611 * a zero MTU in the ICMP message. 1612 */ 1613 if (mtu == 0 && 1614 old_mtu >= 68 + (iph->ihl << 2)) 1615 old_mtu -= iph->ihl << 2; 1616 mtu = guess_mtu(old_mtu); 1617 } 1618 1619 if (mtu < ip_rt_min_pmtu) 1620 mtu = ip_rt_min_pmtu; 1621 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { 1622 unsigned long pmtu_expires; 1623 1624 pmtu_expires = jiffies + ip_rt_mtu_expires; 1625 if (!pmtu_expires) 1626 pmtu_expires = 1UL; 1627 1628 est_mtu = mtu; 1629 peer->pmtu_learned = mtu; 1630 peer->pmtu_expires = pmtu_expires; 1631 atomic_inc(&__rt_peer_genid); 1632 } 1633 1634 inet_putpeer(peer); 1635 } 1636 return est_mtu ? : new_mtu; 1637 } 1638 1639 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) 1640 { 1641 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires); 1642 1643 if (!expires) 1644 return; 1645 if (time_before(jiffies, expires)) { 1646 u32 orig_dst_mtu = dst_mtu(dst); 1647 if (peer->pmtu_learned < orig_dst_mtu) { 1648 if (!peer->pmtu_orig) 1649 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU); 1650 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned); 1651 } 1652 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires) 1653 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig); 1654 } 1655 1656 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 1657 { 1658 struct rtable *rt = (struct rtable *) dst; 1659 struct inet_peer *peer; 1660 1661 dst_confirm(dst); 1662 1663 if (!rt->peer) 1664 rt_bind_peer(rt, rt->rt_dst, 1); 1665 peer = rt->peer; 1666 if (peer) { 1667 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires); 1668 1669 if (mtu < ip_rt_min_pmtu) 1670 mtu = ip_rt_min_pmtu; 1671 if (!pmtu_expires || mtu < peer->pmtu_learned) { 1672 1673 pmtu_expires = jiffies + ip_rt_mtu_expires; 1674 if (!pmtu_expires) 1675 pmtu_expires = 1UL; 1676 1677 peer->pmtu_learned = mtu; 1678 peer->pmtu_expires = pmtu_expires; 1679 1680 atomic_inc(&__rt_peer_genid); 1681 rt->rt_peer_genid = rt_peer_genid(); 1682 } 1683 check_peer_pmtu(dst, peer); 1684 } 1685 } 1686 1687 1688 static void ipv4_validate_peer(struct rtable *rt) 1689 { 1690 if (rt->rt_peer_genid != rt_peer_genid()) { 1691 struct inet_peer *peer; 1692 1693 if (!rt->peer) 1694 rt_bind_peer(rt, rt->rt_dst, 0); 1695 1696 peer = rt->peer; 1697 if (peer) { 1698 check_peer_pmtu(&rt->dst, peer); 1699 1700 if (peer->redirect_genid != redirect_genid) 1701 peer->redirect_learned.a4 = 0; 1702 if (peer->redirect_learned.a4 && 1703 peer->redirect_learned.a4 != rt->rt_gateway) 1704 check_peer_redir(&rt->dst, peer); 1705 } 1706 1707 rt->rt_peer_genid = rt_peer_genid(); 1708 } 1709 } 1710 1711 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1712 { 1713 struct rtable *rt = (struct rtable *) dst; 1714 1715 if (rt_is_expired(rt)) 1716 return NULL; 1717 ipv4_validate_peer(rt); 1718 return dst; 1719 } 1720 1721 static void ipv4_dst_destroy(struct dst_entry *dst) 1722 { 1723 struct rtable *rt = (struct rtable *) dst; 1724 struct inet_peer *peer = rt->peer; 1725 1726 if (rt->fi) { 1727 fib_info_put(rt->fi); 1728 rt->fi = NULL; 1729 } 1730 if (peer) { 1731 rt->peer = NULL; 1732 inet_putpeer(peer); 1733 } 1734 } 1735 1736 1737 static void ipv4_link_failure(struct sk_buff *skb) 1738 { 1739 struct rtable *rt; 1740 1741 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1742 1743 rt = skb_rtable(skb); 1744 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer)) 1745 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); 1746 } 1747 1748 static int ip_rt_bug(struct sk_buff *skb) 1749 { 1750 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n", 1751 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1752 skb->dev ? skb->dev->name : "?"); 1753 kfree_skb(skb); 1754 WARN_ON(1); 1755 return 0; 1756 } 1757 1758 /* 1759 We do not cache source address of outgoing interface, 1760 because it is used only by IP RR, TS and SRR options, 1761 so that it out of fast path. 1762 1763 BTW remember: "addr" is allowed to be not aligned 1764 in IP options! 1765 */ 1766 1767 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1768 { 1769 __be32 src; 1770 1771 if (rt_is_output_route(rt)) 1772 src = ip_hdr(skb)->saddr; 1773 else { 1774 struct fib_result res; 1775 struct flowi4 fl4; 1776 struct iphdr *iph; 1777 1778 iph = ip_hdr(skb); 1779 1780 memset(&fl4, 0, sizeof(fl4)); 1781 fl4.daddr = iph->daddr; 1782 fl4.saddr = iph->saddr; 1783 fl4.flowi4_tos = RT_TOS(iph->tos); 1784 fl4.flowi4_oif = rt->dst.dev->ifindex; 1785 fl4.flowi4_iif = skb->dev->ifindex; 1786 fl4.flowi4_mark = skb->mark; 1787 1788 rcu_read_lock(); 1789 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1790 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1791 else 1792 src = inet_select_addr(rt->dst.dev, rt->rt_gateway, 1793 RT_SCOPE_UNIVERSE); 1794 rcu_read_unlock(); 1795 } 1796 memcpy(addr, &src, 4); 1797 } 1798 1799 #ifdef CONFIG_IP_ROUTE_CLASSID 1800 static void set_class_tag(struct rtable *rt, u32 tag) 1801 { 1802 if (!(rt->dst.tclassid & 0xFFFF)) 1803 rt->dst.tclassid |= tag & 0xFFFF; 1804 if (!(rt->dst.tclassid & 0xFFFF0000)) 1805 rt->dst.tclassid |= tag & 0xFFFF0000; 1806 } 1807 #endif 1808 1809 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1810 { 1811 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1812 1813 if (advmss == 0) { 1814 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1815 ip_rt_min_advmss); 1816 if (advmss > 65535 - 40) 1817 advmss = 65535 - 40; 1818 } 1819 return advmss; 1820 } 1821 1822 static unsigned int ipv4_mtu(const struct dst_entry *dst) 1823 { 1824 const struct rtable *rt = (const struct rtable *) dst; 1825 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 1826 1827 if (mtu && rt_is_output_route(rt)) 1828 return mtu; 1829 1830 mtu = dst->dev->mtu; 1831 1832 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1833 1834 if (rt->rt_gateway != rt->rt_dst && mtu > 576) 1835 mtu = 576; 1836 } 1837 1838 if (mtu > IP_MAX_MTU) 1839 mtu = IP_MAX_MTU; 1840 1841 return mtu; 1842 } 1843 1844 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, 1845 struct fib_info *fi) 1846 { 1847 struct inet_peer *peer; 1848 int create = 0; 1849 1850 /* If a peer entry exists for this destination, we must hook 1851 * it up in order to get at cached metrics. 1852 */ 1853 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS)) 1854 create = 1; 1855 1856 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create); 1857 if (peer) { 1858 rt->rt_peer_genid = rt_peer_genid(); 1859 if (inet_metrics_new(peer)) 1860 memcpy(peer->metrics, fi->fib_metrics, 1861 sizeof(u32) * RTAX_MAX); 1862 dst_init_metrics(&rt->dst, peer->metrics, false); 1863 1864 check_peer_pmtu(&rt->dst, peer); 1865 if (peer->redirect_genid != redirect_genid) 1866 peer->redirect_learned.a4 = 0; 1867 if (peer->redirect_learned.a4 && 1868 peer->redirect_learned.a4 != rt->rt_gateway) { 1869 rt->rt_gateway = peer->redirect_learned.a4; 1870 rt->rt_flags |= RTCF_REDIRECTED; 1871 } 1872 } else { 1873 if (fi->fib_metrics != (u32 *) dst_default_metrics) { 1874 rt->fi = fi; 1875 atomic_inc(&fi->fib_clntref); 1876 } 1877 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1878 } 1879 } 1880 1881 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4, 1882 const struct fib_result *res, 1883 struct fib_info *fi, u16 type, u32 itag) 1884 { 1885 struct dst_entry *dst = &rt->dst; 1886 1887 if (fi) { 1888 if (FIB_RES_GW(*res) && 1889 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 1890 rt->rt_gateway = FIB_RES_GW(*res); 1891 rt_init_metrics(rt, fl4, fi); 1892 #ifdef CONFIG_IP_ROUTE_CLASSID 1893 dst->tclassid = FIB_RES_NH(*res).nh_tclassid; 1894 #endif 1895 } 1896 1897 if (dst_mtu(dst) > IP_MAX_MTU) 1898 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU); 1899 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40) 1900 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40); 1901 1902 #ifdef CONFIG_IP_ROUTE_CLASSID 1903 #ifdef CONFIG_IP_MULTIPLE_TABLES 1904 set_class_tag(rt, fib_rules_tclass(res)); 1905 #endif 1906 set_class_tag(rt, itag); 1907 #endif 1908 } 1909 1910 static struct rtable *rt_dst_alloc(struct net_device *dev, 1911 bool nopolicy, bool noxfrm) 1912 { 1913 return dst_alloc(&ipv4_dst_ops, dev, 1, -1, 1914 DST_HOST | 1915 (nopolicy ? DST_NOPOLICY : 0) | 1916 (noxfrm ? DST_NOXFRM : 0)); 1917 } 1918 1919 /* called in rcu_read_lock() section */ 1920 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1921 u8 tos, struct net_device *dev, int our) 1922 { 1923 unsigned int hash; 1924 struct rtable *rth; 1925 __be32 spec_dst; 1926 struct in_device *in_dev = __in_dev_get_rcu(dev); 1927 u32 itag = 0; 1928 int err; 1929 1930 /* Primary sanity checks. */ 1931 1932 if (in_dev == NULL) 1933 return -EINVAL; 1934 1935 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1936 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP)) 1937 goto e_inval; 1938 1939 if (ipv4_is_zeronet(saddr)) { 1940 if (!ipv4_is_local_multicast(daddr)) 1941 goto e_inval; 1942 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 1943 } else { 1944 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 1945 &itag); 1946 if (err < 0) 1947 goto e_err; 1948 } 1949 rth = rt_dst_alloc(init_net.loopback_dev, 1950 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 1951 if (!rth) 1952 goto e_nobufs; 1953 1954 #ifdef CONFIG_IP_ROUTE_CLASSID 1955 rth->dst.tclassid = itag; 1956 #endif 1957 rth->dst.output = ip_rt_bug; 1958 1959 rth->rt_key_dst = daddr; 1960 rth->rt_key_src = saddr; 1961 rth->rt_genid = rt_genid(dev_net(dev)); 1962 rth->rt_flags = RTCF_MULTICAST; 1963 rth->rt_type = RTN_MULTICAST; 1964 rth->rt_key_tos = tos; 1965 rth->rt_dst = daddr; 1966 rth->rt_src = saddr; 1967 rth->rt_route_iif = dev->ifindex; 1968 rth->rt_iif = dev->ifindex; 1969 rth->rt_oif = 0; 1970 rth->rt_mark = skb->mark; 1971 rth->rt_gateway = daddr; 1972 rth->rt_spec_dst= spec_dst; 1973 rth->rt_peer_genid = 0; 1974 rth->peer = NULL; 1975 rth->fi = NULL; 1976 if (our) { 1977 rth->dst.input= ip_local_deliver; 1978 rth->rt_flags |= RTCF_LOCAL; 1979 } 1980 1981 #ifdef CONFIG_IP_MROUTE 1982 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1983 rth->dst.input = ip_mr_input; 1984 #endif 1985 RT_CACHE_STAT_INC(in_slow_mc); 1986 1987 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); 1988 rth = rt_intern_hash(hash, rth, skb, dev->ifindex); 1989 return IS_ERR(rth) ? PTR_ERR(rth) : 0; 1990 1991 e_nobufs: 1992 return -ENOBUFS; 1993 e_inval: 1994 return -EINVAL; 1995 e_err: 1996 return err; 1997 } 1998 1999 2000 static void ip_handle_martian_source(struct net_device *dev, 2001 struct in_device *in_dev, 2002 struct sk_buff *skb, 2003 __be32 daddr, 2004 __be32 saddr) 2005 { 2006 RT_CACHE_STAT_INC(in_martian_src); 2007 #ifdef CONFIG_IP_ROUTE_VERBOSE 2008 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 2009 /* 2010 * RFC1812 recommendation, if source is martian, 2011 * the only hint is MAC header. 2012 */ 2013 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n", 2014 &daddr, &saddr, dev->name); 2015 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 2016 int i; 2017 const unsigned char *p = skb_mac_header(skb); 2018 printk(KERN_WARNING "ll header: "); 2019 for (i = 0; i < dev->hard_header_len; i++, p++) { 2020 printk("%02x", *p); 2021 if (i < (dev->hard_header_len - 1)) 2022 printk(":"); 2023 } 2024 printk("\n"); 2025 } 2026 } 2027 #endif 2028 } 2029 2030 /* called in rcu_read_lock() section */ 2031 static int __mkroute_input(struct sk_buff *skb, 2032 const struct fib_result *res, 2033 struct in_device *in_dev, 2034 __be32 daddr, __be32 saddr, u32 tos, 2035 struct rtable **result) 2036 { 2037 struct rtable *rth; 2038 int err; 2039 struct in_device *out_dev; 2040 unsigned int flags = 0; 2041 __be32 spec_dst; 2042 u32 itag; 2043 2044 /* get a working reference to the output device */ 2045 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 2046 if (out_dev == NULL) { 2047 if (net_ratelimit()) 2048 printk(KERN_CRIT "Bug in ip_route_input" \ 2049 "_slow(). Please, report\n"); 2050 return -EINVAL; 2051 } 2052 2053 2054 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 2055 in_dev->dev, &spec_dst, &itag); 2056 if (err < 0) { 2057 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 2058 saddr); 2059 2060 goto cleanup; 2061 } 2062 2063 if (err) 2064 flags |= RTCF_DIRECTSRC; 2065 2066 if (out_dev == in_dev && err && 2067 (IN_DEV_SHARED_MEDIA(out_dev) || 2068 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 2069 flags |= RTCF_DOREDIRECT; 2070 2071 if (skb->protocol != htons(ETH_P_IP)) { 2072 /* Not IP (i.e. ARP). Do not create route, if it is 2073 * invalid for proxy arp. DNAT routes are always valid. 2074 * 2075 * Proxy arp feature have been extended to allow, ARP 2076 * replies back to the same interface, to support 2077 * Private VLAN switch technologies. See arp.c. 2078 */ 2079 if (out_dev == in_dev && 2080 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 2081 err = -EINVAL; 2082 goto cleanup; 2083 } 2084 } 2085 2086 rth = rt_dst_alloc(out_dev->dev, 2087 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2088 IN_DEV_CONF_GET(out_dev, NOXFRM)); 2089 if (!rth) { 2090 err = -ENOBUFS; 2091 goto cleanup; 2092 } 2093 2094 rth->rt_key_dst = daddr; 2095 rth->rt_key_src = saddr; 2096 rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); 2097 rth->rt_flags = flags; 2098 rth->rt_type = res->type; 2099 rth->rt_key_tos = tos; 2100 rth->rt_dst = daddr; 2101 rth->rt_src = saddr; 2102 rth->rt_route_iif = in_dev->dev->ifindex; 2103 rth->rt_iif = in_dev->dev->ifindex; 2104 rth->rt_oif = 0; 2105 rth->rt_mark = skb->mark; 2106 rth->rt_gateway = daddr; 2107 rth->rt_spec_dst= spec_dst; 2108 rth->rt_peer_genid = 0; 2109 rth->peer = NULL; 2110 rth->fi = NULL; 2111 2112 rth->dst.input = ip_forward; 2113 rth->dst.output = ip_output; 2114 2115 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag); 2116 2117 *result = rth; 2118 err = 0; 2119 cleanup: 2120 return err; 2121 } 2122 2123 static int ip_mkroute_input(struct sk_buff *skb, 2124 struct fib_result *res, 2125 const struct flowi4 *fl4, 2126 struct in_device *in_dev, 2127 __be32 daddr, __be32 saddr, u32 tos) 2128 { 2129 struct rtable* rth = NULL; 2130 int err; 2131 unsigned hash; 2132 2133 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2134 if (res->fi && res->fi->fib_nhs > 1) 2135 fib_select_multipath(res); 2136 #endif 2137 2138 /* create a routing cache entry */ 2139 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); 2140 if (err) 2141 return err; 2142 2143 /* put it into the cache */ 2144 hash = rt_hash(daddr, saddr, fl4->flowi4_iif, 2145 rt_genid(dev_net(rth->dst.dev))); 2146 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif); 2147 if (IS_ERR(rth)) 2148 return PTR_ERR(rth); 2149 return 0; 2150 } 2151 2152 /* 2153 * NOTE. We drop all the packets that has local source 2154 * addresses, because every properly looped back packet 2155 * must have correct destination already attached by output routine. 2156 * 2157 * Such approach solves two big problems: 2158 * 1. Not simplex devices are handled properly. 2159 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2160 * called with rcu_read_lock() 2161 */ 2162 2163 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2164 u8 tos, struct net_device *dev) 2165 { 2166 struct fib_result res; 2167 struct in_device *in_dev = __in_dev_get_rcu(dev); 2168 struct flowi4 fl4; 2169 unsigned flags = 0; 2170 u32 itag = 0; 2171 struct rtable * rth; 2172 unsigned hash; 2173 __be32 spec_dst; 2174 int err = -EINVAL; 2175 struct net * net = dev_net(dev); 2176 2177 /* IP on this device is disabled. */ 2178 2179 if (!in_dev) 2180 goto out; 2181 2182 /* Check for the most weird martians, which can be not detected 2183 by fib_lookup. 2184 */ 2185 2186 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 2187 ipv4_is_loopback(saddr)) 2188 goto martian_source; 2189 2190 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2191 goto brd_input; 2192 2193 /* Accept zero addresses only to limited broadcast; 2194 * I even do not know to fix it or not. Waiting for complains :-) 2195 */ 2196 if (ipv4_is_zeronet(saddr)) 2197 goto martian_source; 2198 2199 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr)) 2200 goto martian_destination; 2201 2202 /* 2203 * Now we are ready to route packet. 2204 */ 2205 fl4.flowi4_oif = 0; 2206 fl4.flowi4_iif = dev->ifindex; 2207 fl4.flowi4_mark = skb->mark; 2208 fl4.flowi4_tos = tos; 2209 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2210 fl4.daddr = daddr; 2211 fl4.saddr = saddr; 2212 err = fib_lookup(net, &fl4, &res); 2213 if (err != 0) { 2214 if (!IN_DEV_FORWARD(in_dev)) 2215 goto e_hostunreach; 2216 goto no_route; 2217 } 2218 2219 RT_CACHE_STAT_INC(in_slow_tot); 2220 2221 if (res.type == RTN_BROADCAST) 2222 goto brd_input; 2223 2224 if (res.type == RTN_LOCAL) { 2225 err = fib_validate_source(skb, saddr, daddr, tos, 2226 net->loopback_dev->ifindex, 2227 dev, &spec_dst, &itag); 2228 if (err < 0) 2229 goto martian_source_keep_err; 2230 if (err) 2231 flags |= RTCF_DIRECTSRC; 2232 spec_dst = daddr; 2233 goto local_input; 2234 } 2235 2236 if (!IN_DEV_FORWARD(in_dev)) 2237 goto e_hostunreach; 2238 if (res.type != RTN_UNICAST) 2239 goto martian_destination; 2240 2241 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 2242 out: return err; 2243 2244 brd_input: 2245 if (skb->protocol != htons(ETH_P_IP)) 2246 goto e_inval; 2247 2248 if (ipv4_is_zeronet(saddr)) 2249 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 2250 else { 2251 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 2252 &itag); 2253 if (err < 0) 2254 goto martian_source_keep_err; 2255 if (err) 2256 flags |= RTCF_DIRECTSRC; 2257 } 2258 flags |= RTCF_BROADCAST; 2259 res.type = RTN_BROADCAST; 2260 RT_CACHE_STAT_INC(in_brd); 2261 2262 local_input: 2263 rth = rt_dst_alloc(net->loopback_dev, 2264 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 2265 if (!rth) 2266 goto e_nobufs; 2267 2268 rth->dst.input= ip_local_deliver; 2269 rth->dst.output= ip_rt_bug; 2270 #ifdef CONFIG_IP_ROUTE_CLASSID 2271 rth->dst.tclassid = itag; 2272 #endif 2273 2274 rth->rt_key_dst = daddr; 2275 rth->rt_key_src = saddr; 2276 rth->rt_genid = rt_genid(net); 2277 rth->rt_flags = flags|RTCF_LOCAL; 2278 rth->rt_type = res.type; 2279 rth->rt_key_tos = tos; 2280 rth->rt_dst = daddr; 2281 rth->rt_src = saddr; 2282 #ifdef CONFIG_IP_ROUTE_CLASSID 2283 rth->dst.tclassid = itag; 2284 #endif 2285 rth->rt_route_iif = dev->ifindex; 2286 rth->rt_iif = dev->ifindex; 2287 rth->rt_oif = 0; 2288 rth->rt_mark = skb->mark; 2289 rth->rt_gateway = daddr; 2290 rth->rt_spec_dst= spec_dst; 2291 rth->rt_peer_genid = 0; 2292 rth->peer = NULL; 2293 rth->fi = NULL; 2294 if (res.type == RTN_UNREACHABLE) { 2295 rth->dst.input= ip_error; 2296 rth->dst.error= -err; 2297 rth->rt_flags &= ~RTCF_LOCAL; 2298 } 2299 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net)); 2300 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif); 2301 err = 0; 2302 if (IS_ERR(rth)) 2303 err = PTR_ERR(rth); 2304 goto out; 2305 2306 no_route: 2307 RT_CACHE_STAT_INC(in_no_route); 2308 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 2309 res.type = RTN_UNREACHABLE; 2310 if (err == -ESRCH) 2311 err = -ENETUNREACH; 2312 goto local_input; 2313 2314 /* 2315 * Do not cache martian addresses: they should be logged (RFC1812) 2316 */ 2317 martian_destination: 2318 RT_CACHE_STAT_INC(in_martian_dst); 2319 #ifdef CONFIG_IP_ROUTE_VERBOSE 2320 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 2321 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n", 2322 &daddr, &saddr, dev->name); 2323 #endif 2324 2325 e_hostunreach: 2326 err = -EHOSTUNREACH; 2327 goto out; 2328 2329 e_inval: 2330 err = -EINVAL; 2331 goto out; 2332 2333 e_nobufs: 2334 err = -ENOBUFS; 2335 goto out; 2336 2337 martian_source: 2338 err = -EINVAL; 2339 martian_source_keep_err: 2340 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2341 goto out; 2342 } 2343 2344 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2345 u8 tos, struct net_device *dev, bool noref) 2346 { 2347 struct rtable * rth; 2348 unsigned hash; 2349 int iif = dev->ifindex; 2350 struct net *net; 2351 int res; 2352 2353 net = dev_net(dev); 2354 2355 rcu_read_lock(); 2356 2357 if (!rt_caching(net)) 2358 goto skip_cache; 2359 2360 tos &= IPTOS_RT_MASK; 2361 hash = rt_hash(daddr, saddr, iif, rt_genid(net)); 2362 2363 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 2364 rth = rcu_dereference(rth->dst.rt_next)) { 2365 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) | 2366 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) | 2367 (rth->rt_route_iif ^ iif) | 2368 (rth->rt_key_tos ^ tos)) == 0 && 2369 rth->rt_mark == skb->mark && 2370 net_eq(dev_net(rth->dst.dev), net) && 2371 !rt_is_expired(rth)) { 2372 ipv4_validate_peer(rth); 2373 if (noref) { 2374 dst_use_noref(&rth->dst, jiffies); 2375 skb_dst_set_noref(skb, &rth->dst); 2376 } else { 2377 dst_use(&rth->dst, jiffies); 2378 skb_dst_set(skb, &rth->dst); 2379 } 2380 RT_CACHE_STAT_INC(in_hit); 2381 rcu_read_unlock(); 2382 return 0; 2383 } 2384 RT_CACHE_STAT_INC(in_hlist_search); 2385 } 2386 2387 skip_cache: 2388 /* Multicast recognition logic is moved from route cache to here. 2389 The problem was that too many Ethernet cards have broken/missing 2390 hardware multicast filters :-( As result the host on multicasting 2391 network acquires a lot of useless route cache entries, sort of 2392 SDR messages from all the world. Now we try to get rid of them. 2393 Really, provided software IP multicast filter is organized 2394 reasonably (at least, hashed), it does not result in a slowdown 2395 comparing with route cache reject entries. 2396 Note, that multicast routers are not affected, because 2397 route cache entry is created eventually. 2398 */ 2399 if (ipv4_is_multicast(daddr)) { 2400 struct in_device *in_dev = __in_dev_get_rcu(dev); 2401 2402 if (in_dev) { 2403 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 2404 ip_hdr(skb)->protocol); 2405 if (our 2406 #ifdef CONFIG_IP_MROUTE 2407 || 2408 (!ipv4_is_local_multicast(daddr) && 2409 IN_DEV_MFORWARD(in_dev)) 2410 #endif 2411 ) { 2412 int res = ip_route_input_mc(skb, daddr, saddr, 2413 tos, dev, our); 2414 rcu_read_unlock(); 2415 return res; 2416 } 2417 } 2418 rcu_read_unlock(); 2419 return -EINVAL; 2420 } 2421 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 2422 rcu_read_unlock(); 2423 return res; 2424 } 2425 EXPORT_SYMBOL(ip_route_input_common); 2426 2427 /* called with rcu_read_lock() */ 2428 static struct rtable *__mkroute_output(const struct fib_result *res, 2429 const struct flowi4 *fl4, 2430 __be32 orig_daddr, __be32 orig_saddr, 2431 int orig_oif, __u8 orig_rtos, 2432 struct net_device *dev_out, 2433 unsigned int flags) 2434 { 2435 struct fib_info *fi = res->fi; 2436 struct in_device *in_dev; 2437 u16 type = res->type; 2438 struct rtable *rth; 2439 2440 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 2441 return ERR_PTR(-EINVAL); 2442 2443 if (ipv4_is_lbcast(fl4->daddr)) 2444 type = RTN_BROADCAST; 2445 else if (ipv4_is_multicast(fl4->daddr)) 2446 type = RTN_MULTICAST; 2447 else if (ipv4_is_zeronet(fl4->daddr)) 2448 return ERR_PTR(-EINVAL); 2449 2450 if (dev_out->flags & IFF_LOOPBACK) 2451 flags |= RTCF_LOCAL; 2452 2453 in_dev = __in_dev_get_rcu(dev_out); 2454 if (!in_dev) 2455 return ERR_PTR(-EINVAL); 2456 2457 if (type == RTN_BROADCAST) { 2458 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2459 fi = NULL; 2460 } else if (type == RTN_MULTICAST) { 2461 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2462 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2463 fl4->flowi4_proto)) 2464 flags &= ~RTCF_LOCAL; 2465 /* If multicast route do not exist use 2466 * default one, but do not gateway in this case. 2467 * Yes, it is hack. 2468 */ 2469 if (fi && res->prefixlen < 4) 2470 fi = NULL; 2471 } 2472 2473 rth = rt_dst_alloc(dev_out, 2474 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2475 IN_DEV_CONF_GET(in_dev, NOXFRM)); 2476 if (!rth) 2477 return ERR_PTR(-ENOBUFS); 2478 2479 rth->dst.output = ip_output; 2480 2481 rth->rt_key_dst = orig_daddr; 2482 rth->rt_key_src = orig_saddr; 2483 rth->rt_genid = rt_genid(dev_net(dev_out)); 2484 rth->rt_flags = flags; 2485 rth->rt_type = type; 2486 rth->rt_key_tos = orig_rtos; 2487 rth->rt_dst = fl4->daddr; 2488 rth->rt_src = fl4->saddr; 2489 rth->rt_route_iif = 0; 2490 rth->rt_iif = orig_oif ? : dev_out->ifindex; 2491 rth->rt_oif = orig_oif; 2492 rth->rt_mark = fl4->flowi4_mark; 2493 rth->rt_gateway = fl4->daddr; 2494 rth->rt_spec_dst= fl4->saddr; 2495 rth->rt_peer_genid = 0; 2496 rth->peer = NULL; 2497 rth->fi = NULL; 2498 2499 RT_CACHE_STAT_INC(out_slow_tot); 2500 2501 if (flags & RTCF_LOCAL) { 2502 rth->dst.input = ip_local_deliver; 2503 rth->rt_spec_dst = fl4->daddr; 2504 } 2505 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2506 rth->rt_spec_dst = fl4->saddr; 2507 if (flags & RTCF_LOCAL && 2508 !(dev_out->flags & IFF_LOOPBACK)) { 2509 rth->dst.output = ip_mc_output; 2510 RT_CACHE_STAT_INC(out_slow_mc); 2511 } 2512 #ifdef CONFIG_IP_MROUTE 2513 if (type == RTN_MULTICAST) { 2514 if (IN_DEV_MFORWARD(in_dev) && 2515 !ipv4_is_local_multicast(fl4->daddr)) { 2516 rth->dst.input = ip_mr_input; 2517 rth->dst.output = ip_mc_output; 2518 } 2519 } 2520 #endif 2521 } 2522 2523 rt_set_nexthop(rth, fl4, res, fi, type, 0); 2524 2525 return rth; 2526 } 2527 2528 /* 2529 * Major route resolver routine. 2530 * called with rcu_read_lock(); 2531 */ 2532 2533 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) 2534 { 2535 struct net_device *dev_out = NULL; 2536 __u8 tos = RT_FL_TOS(fl4); 2537 unsigned int flags = 0; 2538 struct fib_result res; 2539 struct rtable *rth; 2540 __be32 orig_daddr; 2541 __be32 orig_saddr; 2542 int orig_oif; 2543 2544 res.fi = NULL; 2545 #ifdef CONFIG_IP_MULTIPLE_TABLES 2546 res.r = NULL; 2547 #endif 2548 2549 orig_daddr = fl4->daddr; 2550 orig_saddr = fl4->saddr; 2551 orig_oif = fl4->flowi4_oif; 2552 2553 fl4->flowi4_iif = net->loopback_dev->ifindex; 2554 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2555 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2556 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2557 2558 rcu_read_lock(); 2559 if (fl4->saddr) { 2560 rth = ERR_PTR(-EINVAL); 2561 if (ipv4_is_multicast(fl4->saddr) || 2562 ipv4_is_lbcast(fl4->saddr) || 2563 ipv4_is_zeronet(fl4->saddr)) 2564 goto out; 2565 2566 /* I removed check for oif == dev_out->oif here. 2567 It was wrong for two reasons: 2568 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2569 is assigned to multiple interfaces. 2570 2. Moreover, we are allowed to send packets with saddr 2571 of another iface. --ANK 2572 */ 2573 2574 if (fl4->flowi4_oif == 0 && 2575 (ipv4_is_multicast(fl4->daddr) || 2576 ipv4_is_lbcast(fl4->daddr))) { 2577 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2578 dev_out = __ip_dev_find(net, fl4->saddr, false); 2579 if (dev_out == NULL) 2580 goto out; 2581 2582 /* Special hack: user can direct multicasts 2583 and limited broadcast via necessary interface 2584 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2585 This hack is not just for fun, it allows 2586 vic,vat and friends to work. 2587 They bind socket to loopback, set ttl to zero 2588 and expect that it will work. 2589 From the viewpoint of routing cache they are broken, 2590 because we are not allowed to build multicast path 2591 with loopback source addr (look, routing cache 2592 cannot know, that ttl is zero, so that packet 2593 will not leave this host and route is valid). 2594 Luckily, this hack is good workaround. 2595 */ 2596 2597 fl4->flowi4_oif = dev_out->ifindex; 2598 goto make_route; 2599 } 2600 2601 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2602 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2603 if (!__ip_dev_find(net, fl4->saddr, false)) 2604 goto out; 2605 } 2606 } 2607 2608 2609 if (fl4->flowi4_oif) { 2610 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2611 rth = ERR_PTR(-ENODEV); 2612 if (dev_out == NULL) 2613 goto out; 2614 2615 /* RACE: Check return value of inet_select_addr instead. */ 2616 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2617 rth = ERR_PTR(-ENETUNREACH); 2618 goto out; 2619 } 2620 if (ipv4_is_local_multicast(fl4->daddr) || 2621 ipv4_is_lbcast(fl4->daddr)) { 2622 if (!fl4->saddr) 2623 fl4->saddr = inet_select_addr(dev_out, 0, 2624 RT_SCOPE_LINK); 2625 goto make_route; 2626 } 2627 if (fl4->saddr) { 2628 if (ipv4_is_multicast(fl4->daddr)) 2629 fl4->saddr = inet_select_addr(dev_out, 0, 2630 fl4->flowi4_scope); 2631 else if (!fl4->daddr) 2632 fl4->saddr = inet_select_addr(dev_out, 0, 2633 RT_SCOPE_HOST); 2634 } 2635 } 2636 2637 if (!fl4->daddr) { 2638 fl4->daddr = fl4->saddr; 2639 if (!fl4->daddr) 2640 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2641 dev_out = net->loopback_dev; 2642 fl4->flowi4_oif = net->loopback_dev->ifindex; 2643 res.type = RTN_LOCAL; 2644 flags |= RTCF_LOCAL; 2645 goto make_route; 2646 } 2647 2648 if (fib_lookup(net, fl4, &res)) { 2649 res.fi = NULL; 2650 if (fl4->flowi4_oif) { 2651 /* Apparently, routing tables are wrong. Assume, 2652 that the destination is on link. 2653 2654 WHY? DW. 2655 Because we are allowed to send to iface 2656 even if it has NO routes and NO assigned 2657 addresses. When oif is specified, routing 2658 tables are looked up with only one purpose: 2659 to catch if destination is gatewayed, rather than 2660 direct. Moreover, if MSG_DONTROUTE is set, 2661 we send packet, ignoring both routing tables 2662 and ifaddr state. --ANK 2663 2664 2665 We could make it even if oif is unknown, 2666 likely IPv6, but we do not. 2667 */ 2668 2669 if (fl4->saddr == 0) 2670 fl4->saddr = inet_select_addr(dev_out, 0, 2671 RT_SCOPE_LINK); 2672 res.type = RTN_UNICAST; 2673 goto make_route; 2674 } 2675 rth = ERR_PTR(-ENETUNREACH); 2676 goto out; 2677 } 2678 2679 if (res.type == RTN_LOCAL) { 2680 if (!fl4->saddr) { 2681 if (res.fi->fib_prefsrc) 2682 fl4->saddr = res.fi->fib_prefsrc; 2683 else 2684 fl4->saddr = fl4->daddr; 2685 } 2686 dev_out = net->loopback_dev; 2687 fl4->flowi4_oif = dev_out->ifindex; 2688 res.fi = NULL; 2689 flags |= RTCF_LOCAL; 2690 goto make_route; 2691 } 2692 2693 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2694 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2695 fib_select_multipath(&res); 2696 else 2697 #endif 2698 if (!res.prefixlen && 2699 res.table->tb_num_default > 1 && 2700 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2701 fib_select_default(&res); 2702 2703 if (!fl4->saddr) 2704 fl4->saddr = FIB_RES_PREFSRC(net, res); 2705 2706 dev_out = FIB_RES_DEV(res); 2707 fl4->flowi4_oif = dev_out->ifindex; 2708 2709 2710 make_route: 2711 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif, 2712 tos, dev_out, flags); 2713 if (!IS_ERR(rth)) { 2714 unsigned int hash; 2715 2716 hash = rt_hash(orig_daddr, orig_saddr, orig_oif, 2717 rt_genid(dev_net(dev_out))); 2718 rth = rt_intern_hash(hash, rth, NULL, orig_oif); 2719 } 2720 2721 out: 2722 rcu_read_unlock(); 2723 return rth; 2724 } 2725 2726 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) 2727 { 2728 struct rtable *rth; 2729 unsigned int hash; 2730 2731 if (!rt_caching(net)) 2732 goto slow_output; 2733 2734 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net)); 2735 2736 rcu_read_lock_bh(); 2737 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; 2738 rth = rcu_dereference_bh(rth->dst.rt_next)) { 2739 if (rth->rt_key_dst == flp4->daddr && 2740 rth->rt_key_src == flp4->saddr && 2741 rt_is_output_route(rth) && 2742 rth->rt_oif == flp4->flowi4_oif && 2743 rth->rt_mark == flp4->flowi4_mark && 2744 !((rth->rt_key_tos ^ flp4->flowi4_tos) & 2745 (IPTOS_RT_MASK | RTO_ONLINK)) && 2746 net_eq(dev_net(rth->dst.dev), net) && 2747 !rt_is_expired(rth)) { 2748 ipv4_validate_peer(rth); 2749 dst_use(&rth->dst, jiffies); 2750 RT_CACHE_STAT_INC(out_hit); 2751 rcu_read_unlock_bh(); 2752 if (!flp4->saddr) 2753 flp4->saddr = rth->rt_src; 2754 if (!flp4->daddr) 2755 flp4->daddr = rth->rt_dst; 2756 return rth; 2757 } 2758 RT_CACHE_STAT_INC(out_hlist_search); 2759 } 2760 rcu_read_unlock_bh(); 2761 2762 slow_output: 2763 return ip_route_output_slow(net, flp4); 2764 } 2765 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2766 2767 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2768 { 2769 return NULL; 2770 } 2771 2772 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst) 2773 { 2774 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 2775 2776 return mtu ? : dst->dev->mtu; 2777 } 2778 2779 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) 2780 { 2781 } 2782 2783 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2784 unsigned long old) 2785 { 2786 return NULL; 2787 } 2788 2789 static struct dst_ops ipv4_dst_blackhole_ops = { 2790 .family = AF_INET, 2791 .protocol = cpu_to_be16(ETH_P_IP), 2792 .destroy = ipv4_dst_destroy, 2793 .check = ipv4_blackhole_dst_check, 2794 .mtu = ipv4_blackhole_mtu, 2795 .default_advmss = ipv4_default_advmss, 2796 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2797 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2798 .neigh_lookup = ipv4_neigh_lookup, 2799 }; 2800 2801 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2802 { 2803 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0); 2804 struct rtable *ort = (struct rtable *) dst_orig; 2805 2806 if (rt) { 2807 struct dst_entry *new = &rt->dst; 2808 2809 new->__use = 1; 2810 new->input = dst_discard; 2811 new->output = dst_discard; 2812 dst_copy_metrics(new, &ort->dst); 2813 2814 new->dev = ort->dst.dev; 2815 if (new->dev) 2816 dev_hold(new->dev); 2817 2818 rt->rt_key_dst = ort->rt_key_dst; 2819 rt->rt_key_src = ort->rt_key_src; 2820 rt->rt_key_tos = ort->rt_key_tos; 2821 rt->rt_route_iif = ort->rt_route_iif; 2822 rt->rt_iif = ort->rt_iif; 2823 rt->rt_oif = ort->rt_oif; 2824 rt->rt_mark = ort->rt_mark; 2825 2826 rt->rt_genid = rt_genid(net); 2827 rt->rt_flags = ort->rt_flags; 2828 rt->rt_type = ort->rt_type; 2829 rt->rt_dst = ort->rt_dst; 2830 rt->rt_src = ort->rt_src; 2831 rt->rt_gateway = ort->rt_gateway; 2832 rt->rt_spec_dst = ort->rt_spec_dst; 2833 rt->peer = ort->peer; 2834 if (rt->peer) 2835 atomic_inc(&rt->peer->refcnt); 2836 rt->fi = ort->fi; 2837 if (rt->fi) 2838 atomic_inc(&rt->fi->fib_clntref); 2839 2840 dst_free(new); 2841 } 2842 2843 dst_release(dst_orig); 2844 2845 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2846 } 2847 2848 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2849 struct sock *sk) 2850 { 2851 struct rtable *rt = __ip_route_output_key(net, flp4); 2852 2853 if (IS_ERR(rt)) 2854 return rt; 2855 2856 if (flp4->flowi4_proto) 2857 rt = (struct rtable *) xfrm_lookup(net, &rt->dst, 2858 flowi4_to_flowi(flp4), 2859 sk, 0); 2860 2861 return rt; 2862 } 2863 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2864 2865 static int rt_fill_info(struct net *net, 2866 struct sk_buff *skb, u32 pid, u32 seq, int event, 2867 int nowait, unsigned int flags) 2868 { 2869 struct rtable *rt = skb_rtable(skb); 2870 struct rtmsg *r; 2871 struct nlmsghdr *nlh; 2872 unsigned long expires = 0; 2873 const struct inet_peer *peer = rt->peer; 2874 u32 id = 0, ts = 0, tsage = 0, error; 2875 2876 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); 2877 if (nlh == NULL) 2878 return -EMSGSIZE; 2879 2880 r = nlmsg_data(nlh); 2881 r->rtm_family = AF_INET; 2882 r->rtm_dst_len = 32; 2883 r->rtm_src_len = 0; 2884 r->rtm_tos = rt->rt_key_tos; 2885 r->rtm_table = RT_TABLE_MAIN; 2886 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN); 2887 r->rtm_type = rt->rt_type; 2888 r->rtm_scope = RT_SCOPE_UNIVERSE; 2889 r->rtm_protocol = RTPROT_UNSPEC; 2890 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2891 if (rt->rt_flags & RTCF_NOTIFY) 2892 r->rtm_flags |= RTM_F_NOTIFY; 2893 2894 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst); 2895 2896 if (rt->rt_key_src) { 2897 r->rtm_src_len = 32; 2898 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src); 2899 } 2900 if (rt->dst.dev) 2901 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex); 2902 #ifdef CONFIG_IP_ROUTE_CLASSID 2903 if (rt->dst.tclassid) 2904 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid); 2905 #endif 2906 if (rt_is_input_route(rt)) 2907 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); 2908 else if (rt->rt_src != rt->rt_key_src) 2909 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src); 2910 2911 if (rt->rt_dst != rt->rt_gateway) 2912 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway); 2913 2914 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 2915 goto nla_put_failure; 2916 2917 if (rt->rt_mark) 2918 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark); 2919 2920 error = rt->dst.error; 2921 if (peer) { 2922 inet_peer_refcheck(rt->peer); 2923 id = atomic_read(&peer->ip_id_count) & 0xffff; 2924 if (peer->tcp_ts_stamp) { 2925 ts = peer->tcp_ts; 2926 tsage = get_seconds() - peer->tcp_ts_stamp; 2927 } 2928 expires = ACCESS_ONCE(peer->pmtu_expires); 2929 if (expires) { 2930 if (time_before(jiffies, expires)) 2931 expires -= jiffies; 2932 else 2933 expires = 0; 2934 } 2935 } 2936 2937 if (rt_is_input_route(rt)) { 2938 #ifdef CONFIG_IP_MROUTE 2939 __be32 dst = rt->rt_dst; 2940 2941 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2942 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2943 int err = ipmr_get_route(net, skb, 2944 rt->rt_src, rt->rt_dst, 2945 r, nowait); 2946 if (err <= 0) { 2947 if (!nowait) { 2948 if (err == 0) 2949 return 0; 2950 goto nla_put_failure; 2951 } else { 2952 if (err == -EMSGSIZE) 2953 goto nla_put_failure; 2954 error = err; 2955 } 2956 } 2957 } else 2958 #endif 2959 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif); 2960 } 2961 2962 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage, 2963 expires, error) < 0) 2964 goto nla_put_failure; 2965 2966 return nlmsg_end(skb, nlh); 2967 2968 nla_put_failure: 2969 nlmsg_cancel(skb, nlh); 2970 return -EMSGSIZE; 2971 } 2972 2973 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2974 { 2975 struct net *net = sock_net(in_skb->sk); 2976 struct rtmsg *rtm; 2977 struct nlattr *tb[RTA_MAX+1]; 2978 struct rtable *rt = NULL; 2979 __be32 dst = 0; 2980 __be32 src = 0; 2981 u32 iif; 2982 int err; 2983 int mark; 2984 struct sk_buff *skb; 2985 2986 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2987 if (err < 0) 2988 goto errout; 2989 2990 rtm = nlmsg_data(nlh); 2991 2992 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2993 if (skb == NULL) { 2994 err = -ENOBUFS; 2995 goto errout; 2996 } 2997 2998 /* Reserve room for dummy headers, this skb can pass 2999 through good chunk of routing engine. 3000 */ 3001 skb_reset_mac_header(skb); 3002 skb_reset_network_header(skb); 3003 3004 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 3005 ip_hdr(skb)->protocol = IPPROTO_ICMP; 3006 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 3007 3008 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 3009 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 3010 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 3011 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 3012 3013 if (iif) { 3014 struct net_device *dev; 3015 3016 dev = __dev_get_by_index(net, iif); 3017 if (dev == NULL) { 3018 err = -ENODEV; 3019 goto errout_free; 3020 } 3021 3022 skb->protocol = htons(ETH_P_IP); 3023 skb->dev = dev; 3024 skb->mark = mark; 3025 local_bh_disable(); 3026 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 3027 local_bh_enable(); 3028 3029 rt = skb_rtable(skb); 3030 if (err == 0 && rt->dst.error) 3031 err = -rt->dst.error; 3032 } else { 3033 struct flowi4 fl4 = { 3034 .daddr = dst, 3035 .saddr = src, 3036 .flowi4_tos = rtm->rtm_tos, 3037 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, 3038 .flowi4_mark = mark, 3039 }; 3040 rt = ip_route_output_key(net, &fl4); 3041 3042 err = 0; 3043 if (IS_ERR(rt)) 3044 err = PTR_ERR(rt); 3045 } 3046 3047 if (err) 3048 goto errout_free; 3049 3050 skb_dst_set(skb, &rt->dst); 3051 if (rtm->rtm_flags & RTM_F_NOTIFY) 3052 rt->rt_flags |= RTCF_NOTIFY; 3053 3054 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 3055 RTM_NEWROUTE, 0, 0); 3056 if (err <= 0) 3057 goto errout_free; 3058 3059 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); 3060 errout: 3061 return err; 3062 3063 errout_free: 3064 kfree_skb(skb); 3065 goto errout; 3066 } 3067 3068 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) 3069 { 3070 struct rtable *rt; 3071 int h, s_h; 3072 int idx, s_idx; 3073 struct net *net; 3074 3075 net = sock_net(skb->sk); 3076 3077 s_h = cb->args[0]; 3078 if (s_h < 0) 3079 s_h = 0; 3080 s_idx = idx = cb->args[1]; 3081 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { 3082 if (!rt_hash_table[h].chain) 3083 continue; 3084 rcu_read_lock_bh(); 3085 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; 3086 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) { 3087 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx) 3088 continue; 3089 if (rt_is_expired(rt)) 3090 continue; 3091 skb_dst_set_noref(skb, &rt->dst); 3092 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, 3093 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 3094 1, NLM_F_MULTI) <= 0) { 3095 skb_dst_drop(skb); 3096 rcu_read_unlock_bh(); 3097 goto done; 3098 } 3099 skb_dst_drop(skb); 3100 } 3101 rcu_read_unlock_bh(); 3102 } 3103 3104 done: 3105 cb->args[0] = h; 3106 cb->args[1] = idx; 3107 return skb->len; 3108 } 3109 3110 void ip_rt_multicast_event(struct in_device *in_dev) 3111 { 3112 rt_cache_flush(dev_net(in_dev->dev), 0); 3113 } 3114 3115 #ifdef CONFIG_SYSCTL 3116 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, 3117 void __user *buffer, 3118 size_t *lenp, loff_t *ppos) 3119 { 3120 if (write) { 3121 int flush_delay; 3122 ctl_table ctl; 3123 struct net *net; 3124 3125 memcpy(&ctl, __ctl, sizeof(ctl)); 3126 ctl.data = &flush_delay; 3127 proc_dointvec(&ctl, write, buffer, lenp, ppos); 3128 3129 net = (struct net *)__ctl->extra1; 3130 rt_cache_flush(net, flush_delay); 3131 return 0; 3132 } 3133 3134 return -EINVAL; 3135 } 3136 3137 static ctl_table ipv4_route_table[] = { 3138 { 3139 .procname = "gc_thresh", 3140 .data = &ipv4_dst_ops.gc_thresh, 3141 .maxlen = sizeof(int), 3142 .mode = 0644, 3143 .proc_handler = proc_dointvec, 3144 }, 3145 { 3146 .procname = "max_size", 3147 .data = &ip_rt_max_size, 3148 .maxlen = sizeof(int), 3149 .mode = 0644, 3150 .proc_handler = proc_dointvec, 3151 }, 3152 { 3153 /* Deprecated. Use gc_min_interval_ms */ 3154 3155 .procname = "gc_min_interval", 3156 .data = &ip_rt_gc_min_interval, 3157 .maxlen = sizeof(int), 3158 .mode = 0644, 3159 .proc_handler = proc_dointvec_jiffies, 3160 }, 3161 { 3162 .procname = "gc_min_interval_ms", 3163 .data = &ip_rt_gc_min_interval, 3164 .maxlen = sizeof(int), 3165 .mode = 0644, 3166 .proc_handler = proc_dointvec_ms_jiffies, 3167 }, 3168 { 3169 .procname = "gc_timeout", 3170 .data = &ip_rt_gc_timeout, 3171 .maxlen = sizeof(int), 3172 .mode = 0644, 3173 .proc_handler = proc_dointvec_jiffies, 3174 }, 3175 { 3176 .procname = "redirect_load", 3177 .data = &ip_rt_redirect_load, 3178 .maxlen = sizeof(int), 3179 .mode = 0644, 3180 .proc_handler = proc_dointvec, 3181 }, 3182 { 3183 .procname = "redirect_number", 3184 .data = &ip_rt_redirect_number, 3185 .maxlen = sizeof(int), 3186 .mode = 0644, 3187 .proc_handler = proc_dointvec, 3188 }, 3189 { 3190 .procname = "redirect_silence", 3191 .data = &ip_rt_redirect_silence, 3192 .maxlen = sizeof(int), 3193 .mode = 0644, 3194 .proc_handler = proc_dointvec, 3195 }, 3196 { 3197 .procname = "error_cost", 3198 .data = &ip_rt_error_cost, 3199 .maxlen = sizeof(int), 3200 .mode = 0644, 3201 .proc_handler = proc_dointvec, 3202 }, 3203 { 3204 .procname = "error_burst", 3205 .data = &ip_rt_error_burst, 3206 .maxlen = sizeof(int), 3207 .mode = 0644, 3208 .proc_handler = proc_dointvec, 3209 }, 3210 { 3211 .procname = "gc_elasticity", 3212 .data = &ip_rt_gc_elasticity, 3213 .maxlen = sizeof(int), 3214 .mode = 0644, 3215 .proc_handler = proc_dointvec, 3216 }, 3217 { 3218 .procname = "mtu_expires", 3219 .data = &ip_rt_mtu_expires, 3220 .maxlen = sizeof(int), 3221 .mode = 0644, 3222 .proc_handler = proc_dointvec_jiffies, 3223 }, 3224 { 3225 .procname = "min_pmtu", 3226 .data = &ip_rt_min_pmtu, 3227 .maxlen = sizeof(int), 3228 .mode = 0644, 3229 .proc_handler = proc_dointvec, 3230 }, 3231 { 3232 .procname = "min_adv_mss", 3233 .data = &ip_rt_min_advmss, 3234 .maxlen = sizeof(int), 3235 .mode = 0644, 3236 .proc_handler = proc_dointvec, 3237 }, 3238 { } 3239 }; 3240 3241 static struct ctl_table empty[1]; 3242 3243 static struct ctl_table ipv4_skeleton[] = 3244 { 3245 { .procname = "route", 3246 .mode = 0555, .child = ipv4_route_table}, 3247 { .procname = "neigh", 3248 .mode = 0555, .child = empty}, 3249 { } 3250 }; 3251 3252 static __net_initdata struct ctl_path ipv4_path[] = { 3253 { .procname = "net", }, 3254 { .procname = "ipv4", }, 3255 { }, 3256 }; 3257 3258 static struct ctl_table ipv4_route_flush_table[] = { 3259 { 3260 .procname = "flush", 3261 .maxlen = sizeof(int), 3262 .mode = 0200, 3263 .proc_handler = ipv4_sysctl_rtcache_flush, 3264 }, 3265 { }, 3266 }; 3267 3268 static __net_initdata struct ctl_path ipv4_route_path[] = { 3269 { .procname = "net", }, 3270 { .procname = "ipv4", }, 3271 { .procname = "route", }, 3272 { }, 3273 }; 3274 3275 static __net_init int sysctl_route_net_init(struct net *net) 3276 { 3277 struct ctl_table *tbl; 3278 3279 tbl = ipv4_route_flush_table; 3280 if (!net_eq(net, &init_net)) { 3281 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3282 if (tbl == NULL) 3283 goto err_dup; 3284 } 3285 tbl[0].extra1 = net; 3286 3287 net->ipv4.route_hdr = 3288 register_net_sysctl_table(net, ipv4_route_path, tbl); 3289 if (net->ipv4.route_hdr == NULL) 3290 goto err_reg; 3291 return 0; 3292 3293 err_reg: 3294 if (tbl != ipv4_route_flush_table) 3295 kfree(tbl); 3296 err_dup: 3297 return -ENOMEM; 3298 } 3299 3300 static __net_exit void sysctl_route_net_exit(struct net *net) 3301 { 3302 struct ctl_table *tbl; 3303 3304 tbl = net->ipv4.route_hdr->ctl_table_arg; 3305 unregister_net_sysctl_table(net->ipv4.route_hdr); 3306 BUG_ON(tbl == ipv4_route_flush_table); 3307 kfree(tbl); 3308 } 3309 3310 static __net_initdata struct pernet_operations sysctl_route_ops = { 3311 .init = sysctl_route_net_init, 3312 .exit = sysctl_route_net_exit, 3313 }; 3314 #endif 3315 3316 static __net_init int rt_genid_init(struct net *net) 3317 { 3318 get_random_bytes(&net->ipv4.rt_genid, 3319 sizeof(net->ipv4.rt_genid)); 3320 get_random_bytes(&net->ipv4.dev_addr_genid, 3321 sizeof(net->ipv4.dev_addr_genid)); 3322 return 0; 3323 } 3324 3325 static __net_initdata struct pernet_operations rt_genid_ops = { 3326 .init = rt_genid_init, 3327 }; 3328 3329 3330 #ifdef CONFIG_IP_ROUTE_CLASSID 3331 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3332 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3333 3334 static __initdata unsigned long rhash_entries; 3335 static int __init set_rhash_entries(char *str) 3336 { 3337 if (!str) 3338 return 0; 3339 rhash_entries = simple_strtoul(str, &str, 0); 3340 return 1; 3341 } 3342 __setup("rhash_entries=", set_rhash_entries); 3343 3344 int __init ip_rt_init(void) 3345 { 3346 int rc = 0; 3347 3348 #ifdef CONFIG_IP_ROUTE_CLASSID 3349 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3350 if (!ip_rt_acct) 3351 panic("IP: failed to allocate ip_rt_acct\n"); 3352 #endif 3353 3354 ipv4_dst_ops.kmem_cachep = 3355 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3356 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3357 3358 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3359 3360 if (dst_entries_init(&ipv4_dst_ops) < 0) 3361 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3362 3363 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3364 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3365 3366 rt_hash_table = (struct rt_hash_bucket *) 3367 alloc_large_system_hash("IP route cache", 3368 sizeof(struct rt_hash_bucket), 3369 rhash_entries, 3370 (totalram_pages >= 128 * 1024) ? 3371 15 : 17, 3372 0, 3373 &rt_hash_log, 3374 &rt_hash_mask, 3375 rhash_entries ? 0 : 512 * 1024); 3376 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); 3377 rt_hash_lock_init(); 3378 3379 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); 3380 ip_rt_max_size = (rt_hash_mask + 1) * 16; 3381 3382 devinet_init(); 3383 ip_fib_init(); 3384 3385 if (ip_rt_proc_init()) 3386 printk(KERN_ERR "Unable to create route proc files\n"); 3387 #ifdef CONFIG_XFRM 3388 xfrm_init(); 3389 xfrm4_init(ip_rt_max_size); 3390 #endif 3391 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 3392 3393 #ifdef CONFIG_SYSCTL 3394 register_pernet_subsys(&sysctl_route_ops); 3395 #endif 3396 register_pernet_subsys(&rt_genid_ops); 3397 return rc; 3398 } 3399 3400 #ifdef CONFIG_SYSCTL 3401 /* 3402 * We really need to sanitize the damn ipv4 init order, then all 3403 * this nonsense will go away. 3404 */ 3405 void __init ip_static_sysctl_init(void) 3406 { 3407 register_sysctl_paths(ipv4_path, ipv4_skeleton); 3408 } 3409 #endif 3410