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 111 112 #define RT_FL_TOS(oldflp4) \ 113 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))) 114 115 #define IP_MAX_MTU 0xFFF0 116 117 #define RT_GC_TIMEOUT (300*HZ) 118 119 static int ip_rt_max_size; 120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 121 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 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; 133 134 /* 135 * Interface to generic destination cache. 136 */ 137 138 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 140 static unsigned int ipv4_default_mtu(const struct dst_entry *dst); 141 static void ipv4_dst_destroy(struct dst_entry *dst); 142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 143 static void ipv4_link_failure(struct sk_buff *skb); 144 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 145 static int rt_garbage_collect(struct dst_ops *ops); 146 147 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 148 int how) 149 { 150 } 151 152 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 153 { 154 struct rtable *rt = (struct rtable *) dst; 155 struct inet_peer *peer; 156 u32 *p = NULL; 157 158 if (!rt->peer) 159 rt_bind_peer(rt, rt->rt_dst, 1); 160 161 peer = rt->peer; 162 if (peer) { 163 u32 *old_p = __DST_METRICS_PTR(old); 164 unsigned long prev, new; 165 166 p = peer->metrics; 167 if (inet_metrics_new(peer)) 168 memcpy(p, old_p, sizeof(u32) * RTAX_MAX); 169 170 new = (unsigned long) p; 171 prev = cmpxchg(&dst->_metrics, old, new); 172 173 if (prev != old) { 174 p = __DST_METRICS_PTR(prev); 175 if (prev & DST_METRICS_READ_ONLY) 176 p = NULL; 177 } else { 178 if (rt->fi) { 179 fib_info_put(rt->fi); 180 rt->fi = NULL; 181 } 182 } 183 } 184 return p; 185 } 186 187 static struct dst_ops ipv4_dst_ops = { 188 .family = AF_INET, 189 .protocol = cpu_to_be16(ETH_P_IP), 190 .gc = rt_garbage_collect, 191 .check = ipv4_dst_check, 192 .default_advmss = ipv4_default_advmss, 193 .default_mtu = ipv4_default_mtu, 194 .cow_metrics = ipv4_cow_metrics, 195 .destroy = ipv4_dst_destroy, 196 .ifdown = ipv4_dst_ifdown, 197 .negative_advice = ipv4_negative_advice, 198 .link_failure = ipv4_link_failure, 199 .update_pmtu = ip_rt_update_pmtu, 200 .local_out = __ip_local_out, 201 }; 202 203 #define ECN_OR_COST(class) TC_PRIO_##class 204 205 const __u8 ip_tos2prio[16] = { 206 TC_PRIO_BESTEFFORT, 207 ECN_OR_COST(BESTEFFORT), 208 TC_PRIO_BESTEFFORT, 209 ECN_OR_COST(BESTEFFORT), 210 TC_PRIO_BULK, 211 ECN_OR_COST(BULK), 212 TC_PRIO_BULK, 213 ECN_OR_COST(BULK), 214 TC_PRIO_INTERACTIVE, 215 ECN_OR_COST(INTERACTIVE), 216 TC_PRIO_INTERACTIVE, 217 ECN_OR_COST(INTERACTIVE), 218 TC_PRIO_INTERACTIVE_BULK, 219 ECN_OR_COST(INTERACTIVE_BULK), 220 TC_PRIO_INTERACTIVE_BULK, 221 ECN_OR_COST(INTERACTIVE_BULK) 222 }; 223 224 225 /* 226 * Route cache. 227 */ 228 229 /* The locking scheme is rather straight forward: 230 * 231 * 1) Read-Copy Update protects the buckets of the central route hash. 232 * 2) Only writers remove entries, and they hold the lock 233 * as they look at rtable reference counts. 234 * 3) Only readers acquire references to rtable entries, 235 * they do so with atomic increments and with the 236 * lock held. 237 */ 238 239 struct rt_hash_bucket { 240 struct rtable __rcu *chain; 241 }; 242 243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ 244 defined(CONFIG_PROVE_LOCKING) 245 /* 246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks 247 * The size of this table is a power of two and depends on the number of CPUS. 248 * (on lockdep we have a quite big spinlock_t, so keep the size down there) 249 */ 250 #ifdef CONFIG_LOCKDEP 251 # define RT_HASH_LOCK_SZ 256 252 #else 253 # if NR_CPUS >= 32 254 # define RT_HASH_LOCK_SZ 4096 255 # elif NR_CPUS >= 16 256 # define RT_HASH_LOCK_SZ 2048 257 # elif NR_CPUS >= 8 258 # define RT_HASH_LOCK_SZ 1024 259 # elif NR_CPUS >= 4 260 # define RT_HASH_LOCK_SZ 512 261 # else 262 # define RT_HASH_LOCK_SZ 256 263 # endif 264 #endif 265 266 static spinlock_t *rt_hash_locks; 267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)] 268 269 static __init void rt_hash_lock_init(void) 270 { 271 int i; 272 273 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, 274 GFP_KERNEL); 275 if (!rt_hash_locks) 276 panic("IP: failed to allocate rt_hash_locks\n"); 277 278 for (i = 0; i < RT_HASH_LOCK_SZ; i++) 279 spin_lock_init(&rt_hash_locks[i]); 280 } 281 #else 282 # define rt_hash_lock_addr(slot) NULL 283 284 static inline void rt_hash_lock_init(void) 285 { 286 } 287 #endif 288 289 static struct rt_hash_bucket *rt_hash_table __read_mostly; 290 static unsigned rt_hash_mask __read_mostly; 291 static unsigned int rt_hash_log __read_mostly; 292 293 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) 295 296 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, 297 int genid) 298 { 299 return jhash_3words((__force u32)daddr, (__force u32)saddr, 300 idx, genid) 301 & rt_hash_mask; 302 } 303 304 static inline int rt_genid(struct net *net) 305 { 306 return atomic_read(&net->ipv4.rt_genid); 307 } 308 309 #ifdef CONFIG_PROC_FS 310 struct rt_cache_iter_state { 311 struct seq_net_private p; 312 int bucket; 313 int genid; 314 }; 315 316 static struct rtable *rt_cache_get_first(struct seq_file *seq) 317 { 318 struct rt_cache_iter_state *st = seq->private; 319 struct rtable *r = NULL; 320 321 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { 322 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain)) 323 continue; 324 rcu_read_lock_bh(); 325 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); 326 while (r) { 327 if (dev_net(r->dst.dev) == seq_file_net(seq) && 328 r->rt_genid == st->genid) 329 return r; 330 r = rcu_dereference_bh(r->dst.rt_next); 331 } 332 rcu_read_unlock_bh(); 333 } 334 return r; 335 } 336 337 static struct rtable *__rt_cache_get_next(struct seq_file *seq, 338 struct rtable *r) 339 { 340 struct rt_cache_iter_state *st = seq->private; 341 342 r = rcu_dereference_bh(r->dst.rt_next); 343 while (!r) { 344 rcu_read_unlock_bh(); 345 do { 346 if (--st->bucket < 0) 347 return NULL; 348 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain)); 349 rcu_read_lock_bh(); 350 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); 351 } 352 return r; 353 } 354 355 static struct rtable *rt_cache_get_next(struct seq_file *seq, 356 struct rtable *r) 357 { 358 struct rt_cache_iter_state *st = seq->private; 359 while ((r = __rt_cache_get_next(seq, r)) != NULL) { 360 if (dev_net(r->dst.dev) != seq_file_net(seq)) 361 continue; 362 if (r->rt_genid == st->genid) 363 break; 364 } 365 return r; 366 } 367 368 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos) 369 { 370 struct rtable *r = rt_cache_get_first(seq); 371 372 if (r) 373 while (pos && (r = rt_cache_get_next(seq, r))) 374 --pos; 375 return pos ? NULL : r; 376 } 377 378 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 379 { 380 struct rt_cache_iter_state *st = seq->private; 381 if (*pos) 382 return rt_cache_get_idx(seq, *pos - 1); 383 st->genid = rt_genid(seq_file_net(seq)); 384 return SEQ_START_TOKEN; 385 } 386 387 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 388 { 389 struct rtable *r; 390 391 if (v == SEQ_START_TOKEN) 392 r = rt_cache_get_first(seq); 393 else 394 r = rt_cache_get_next(seq, v); 395 ++*pos; 396 return r; 397 } 398 399 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 400 { 401 if (v && v != SEQ_START_TOKEN) 402 rcu_read_unlock_bh(); 403 } 404 405 static int rt_cache_seq_show(struct seq_file *seq, void *v) 406 { 407 if (v == SEQ_START_TOKEN) 408 seq_printf(seq, "%-127s\n", 409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 411 "HHUptod\tSpecDst"); 412 else { 413 struct rtable *r = v; 414 int len; 415 416 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" 417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", 418 r->dst.dev ? r->dst.dev->name : "*", 419 (__force u32)r->rt_dst, 420 (__force u32)r->rt_gateway, 421 r->rt_flags, atomic_read(&r->dst.__refcnt), 422 r->dst.__use, 0, (__force u32)r->rt_src, 423 dst_metric_advmss(&r->dst) + 40, 424 dst_metric(&r->dst, RTAX_WINDOW), 425 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) + 426 dst_metric(&r->dst, RTAX_RTTVAR)), 427 r->rt_key_tos, 428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1, 429 r->dst.hh ? (r->dst.hh->hh_output == 430 dev_queue_xmit) : 0, 431 r->rt_spec_dst, &len); 432 433 seq_printf(seq, "%*s\n", 127 - len, ""); 434 } 435 return 0; 436 } 437 438 static const struct seq_operations rt_cache_seq_ops = { 439 .start = rt_cache_seq_start, 440 .next = rt_cache_seq_next, 441 .stop = rt_cache_seq_stop, 442 .show = rt_cache_seq_show, 443 }; 444 445 static int rt_cache_seq_open(struct inode *inode, struct file *file) 446 { 447 return seq_open_net(inode, file, &rt_cache_seq_ops, 448 sizeof(struct rt_cache_iter_state)); 449 } 450 451 static const struct file_operations rt_cache_seq_fops = { 452 .owner = THIS_MODULE, 453 .open = rt_cache_seq_open, 454 .read = seq_read, 455 .llseek = seq_lseek, 456 .release = seq_release_net, 457 }; 458 459 460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 461 { 462 int cpu; 463 464 if (*pos == 0) 465 return SEQ_START_TOKEN; 466 467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 468 if (!cpu_possible(cpu)) 469 continue; 470 *pos = cpu+1; 471 return &per_cpu(rt_cache_stat, cpu); 472 } 473 return NULL; 474 } 475 476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 477 { 478 int cpu; 479 480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 481 if (!cpu_possible(cpu)) 482 continue; 483 *pos = cpu+1; 484 return &per_cpu(rt_cache_stat, cpu); 485 } 486 return NULL; 487 488 } 489 490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 491 { 492 493 } 494 495 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 496 { 497 struct rt_cache_stat *st = v; 498 499 if (v == SEQ_START_TOKEN) { 500 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"); 501 return 0; 502 } 503 504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 506 dst_entries_get_slow(&ipv4_dst_ops), 507 st->in_hit, 508 st->in_slow_tot, 509 st->in_slow_mc, 510 st->in_no_route, 511 st->in_brd, 512 st->in_martian_dst, 513 st->in_martian_src, 514 515 st->out_hit, 516 st->out_slow_tot, 517 st->out_slow_mc, 518 519 st->gc_total, 520 st->gc_ignored, 521 st->gc_goal_miss, 522 st->gc_dst_overflow, 523 st->in_hlist_search, 524 st->out_hlist_search 525 ); 526 return 0; 527 } 528 529 static const struct seq_operations rt_cpu_seq_ops = { 530 .start = rt_cpu_seq_start, 531 .next = rt_cpu_seq_next, 532 .stop = rt_cpu_seq_stop, 533 .show = rt_cpu_seq_show, 534 }; 535 536 537 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 538 { 539 return seq_open(file, &rt_cpu_seq_ops); 540 } 541 542 static const struct file_operations rt_cpu_seq_fops = { 543 .owner = THIS_MODULE, 544 .open = rt_cpu_seq_open, 545 .read = seq_read, 546 .llseek = seq_lseek, 547 .release = seq_release, 548 }; 549 550 #ifdef CONFIG_IP_ROUTE_CLASSID 551 static int rt_acct_proc_show(struct seq_file *m, void *v) 552 { 553 struct ip_rt_acct *dst, *src; 554 unsigned int i, j; 555 556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 557 if (!dst) 558 return -ENOMEM; 559 560 for_each_possible_cpu(i) { 561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 562 for (j = 0; j < 256; j++) { 563 dst[j].o_bytes += src[j].o_bytes; 564 dst[j].o_packets += src[j].o_packets; 565 dst[j].i_bytes += src[j].i_bytes; 566 dst[j].i_packets += src[j].i_packets; 567 } 568 } 569 570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 571 kfree(dst); 572 return 0; 573 } 574 575 static int rt_acct_proc_open(struct inode *inode, struct file *file) 576 { 577 return single_open(file, rt_acct_proc_show, NULL); 578 } 579 580 static const struct file_operations rt_acct_proc_fops = { 581 .owner = THIS_MODULE, 582 .open = rt_acct_proc_open, 583 .read = seq_read, 584 .llseek = seq_lseek, 585 .release = single_release, 586 }; 587 #endif 588 589 static int __net_init ip_rt_do_proc_init(struct net *net) 590 { 591 struct proc_dir_entry *pde; 592 593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO, 594 &rt_cache_seq_fops); 595 if (!pde) 596 goto err1; 597 598 pde = proc_create("rt_cache", S_IRUGO, 599 net->proc_net_stat, &rt_cpu_seq_fops); 600 if (!pde) 601 goto err2; 602 603 #ifdef CONFIG_IP_ROUTE_CLASSID 604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 605 if (!pde) 606 goto err3; 607 #endif 608 return 0; 609 610 #ifdef CONFIG_IP_ROUTE_CLASSID 611 err3: 612 remove_proc_entry("rt_cache", net->proc_net_stat); 613 #endif 614 err2: 615 remove_proc_entry("rt_cache", net->proc_net); 616 err1: 617 return -ENOMEM; 618 } 619 620 static void __net_exit ip_rt_do_proc_exit(struct net *net) 621 { 622 remove_proc_entry("rt_cache", net->proc_net_stat); 623 remove_proc_entry("rt_cache", net->proc_net); 624 #ifdef CONFIG_IP_ROUTE_CLASSID 625 remove_proc_entry("rt_acct", net->proc_net); 626 #endif 627 } 628 629 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 630 .init = ip_rt_do_proc_init, 631 .exit = ip_rt_do_proc_exit, 632 }; 633 634 static int __init ip_rt_proc_init(void) 635 { 636 return register_pernet_subsys(&ip_rt_proc_ops); 637 } 638 639 #else 640 static inline int ip_rt_proc_init(void) 641 { 642 return 0; 643 } 644 #endif /* CONFIG_PROC_FS */ 645 646 static inline void rt_free(struct rtable *rt) 647 { 648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 649 } 650 651 static inline void rt_drop(struct rtable *rt) 652 { 653 ip_rt_put(rt); 654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 655 } 656 657 static inline int rt_fast_clean(struct rtable *rth) 658 { 659 /* Kill broadcast/multicast entries very aggresively, if they 660 collide in hash table with more useful entries */ 661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) && 662 rt_is_input_route(rth) && rth->dst.rt_next; 663 } 664 665 static inline int rt_valuable(struct rtable *rth) 666 { 667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || 668 (rth->peer && rth->peer->pmtu_expires); 669 } 670 671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2) 672 { 673 unsigned long age; 674 int ret = 0; 675 676 if (atomic_read(&rth->dst.__refcnt)) 677 goto out; 678 679 age = jiffies - rth->dst.lastuse; 680 if ((age <= tmo1 && !rt_fast_clean(rth)) || 681 (age <= tmo2 && rt_valuable(rth))) 682 goto out; 683 ret = 1; 684 out: return ret; 685 } 686 687 /* Bits of score are: 688 * 31: very valuable 689 * 30: not quite useless 690 * 29..0: usage counter 691 */ 692 static inline u32 rt_score(struct rtable *rt) 693 { 694 u32 score = jiffies - rt->dst.lastuse; 695 696 score = ~score & ~(3<<30); 697 698 if (rt_valuable(rt)) 699 score |= (1<<31); 700 701 if (rt_is_output_route(rt) || 702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) 703 score |= (1<<30); 704 705 return score; 706 } 707 708 static inline bool rt_caching(const struct net *net) 709 { 710 return net->ipv4.current_rt_cache_rebuild_count <= 711 net->ipv4.sysctl_rt_cache_rebuild_count; 712 } 713 714 static inline bool compare_hash_inputs(const struct rtable *rt1, 715 const struct rtable *rt2) 716 { 717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | 718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | 719 (rt1->rt_iif ^ rt2->rt_iif)) == 0); 720 } 721 722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2) 723 { 724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | 725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | 726 (rt1->rt_mark ^ rt2->rt_mark) | 727 (rt1->rt_key_tos ^ rt2->rt_key_tos) | 728 (rt1->rt_oif ^ rt2->rt_oif) | 729 (rt1->rt_iif ^ rt2->rt_iif)) == 0; 730 } 731 732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) 733 { 734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev)); 735 } 736 737 static inline int rt_is_expired(struct rtable *rth) 738 { 739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); 740 } 741 742 /* 743 * Perform a full scan of hash table and free all entries. 744 * Can be called by a softirq or a process. 745 * In the later case, we want to be reschedule if necessary 746 */ 747 static void rt_do_flush(struct net *net, int process_context) 748 { 749 unsigned int i; 750 struct rtable *rth, *next; 751 752 for (i = 0; i <= rt_hash_mask; i++) { 753 struct rtable __rcu **pprev; 754 struct rtable *list; 755 756 if (process_context && need_resched()) 757 cond_resched(); 758 rth = rcu_dereference_raw(rt_hash_table[i].chain); 759 if (!rth) 760 continue; 761 762 spin_lock_bh(rt_hash_lock_addr(i)); 763 764 list = NULL; 765 pprev = &rt_hash_table[i].chain; 766 rth = rcu_dereference_protected(*pprev, 767 lockdep_is_held(rt_hash_lock_addr(i))); 768 769 while (rth) { 770 next = rcu_dereference_protected(rth->dst.rt_next, 771 lockdep_is_held(rt_hash_lock_addr(i))); 772 773 if (!net || 774 net_eq(dev_net(rth->dst.dev), net)) { 775 rcu_assign_pointer(*pprev, next); 776 rcu_assign_pointer(rth->dst.rt_next, list); 777 list = rth; 778 } else { 779 pprev = &rth->dst.rt_next; 780 } 781 rth = next; 782 } 783 784 spin_unlock_bh(rt_hash_lock_addr(i)); 785 786 for (; list; list = next) { 787 next = rcu_dereference_protected(list->dst.rt_next, 1); 788 rt_free(list); 789 } 790 } 791 } 792 793 /* 794 * While freeing expired entries, we compute average chain length 795 * and standard deviation, using fixed-point arithmetic. 796 * This to have an estimation of rt_chain_length_max 797 * rt_chain_length_max = max(elasticity, AVG + 4*SD) 798 * We use 3 bits for frational part, and 29 (or 61) for magnitude. 799 */ 800 801 #define FRACT_BITS 3 802 #define ONE (1UL << FRACT_BITS) 803 804 /* 805 * Given a hash chain and an item in this hash chain, 806 * find if a previous entry has the same hash_inputs 807 * (but differs on tos, mark or oif) 808 * Returns 0 if an alias is found. 809 * Returns ONE if rth has no alias before itself. 810 */ 811 static int has_noalias(const struct rtable *head, const struct rtable *rth) 812 { 813 const struct rtable *aux = head; 814 815 while (aux != rth) { 816 if (compare_hash_inputs(aux, rth)) 817 return 0; 818 aux = rcu_dereference_protected(aux->dst.rt_next, 1); 819 } 820 return ONE; 821 } 822 823 /* 824 * Perturbation of rt_genid by a small quantity [1..256] 825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() 826 * many times (2^24) without giving recent rt_genid. 827 * Jenkins hash is strong enough that litle changes of rt_genid are OK. 828 */ 829 static void rt_cache_invalidate(struct net *net) 830 { 831 unsigned char shuffle; 832 833 get_random_bytes(&shuffle, sizeof(shuffle)); 834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid); 835 } 836 837 /* 838 * delay < 0 : invalidate cache (fast : entries will be deleted later) 839 * delay >= 0 : invalidate & flush cache (can be long) 840 */ 841 void rt_cache_flush(struct net *net, int delay) 842 { 843 rt_cache_invalidate(net); 844 if (delay >= 0) 845 rt_do_flush(net, !in_softirq()); 846 } 847 848 /* Flush previous cache invalidated entries from the cache */ 849 void rt_cache_flush_batch(struct net *net) 850 { 851 rt_do_flush(net, !in_softirq()); 852 } 853 854 static void rt_emergency_hash_rebuild(struct net *net) 855 { 856 if (net_ratelimit()) 857 printk(KERN_WARNING "Route hash chain too long!\n"); 858 rt_cache_invalidate(net); 859 } 860 861 /* 862 Short description of GC goals. 863 864 We want to build algorithm, which will keep routing cache 865 at some equilibrium point, when number of aged off entries 866 is kept approximately equal to newly generated ones. 867 868 Current expiration strength is variable "expire". 869 We try to adjust it dynamically, so that if networking 870 is idle expires is large enough to keep enough of warm entries, 871 and when load increases it reduces to limit cache size. 872 */ 873 874 static int rt_garbage_collect(struct dst_ops *ops) 875 { 876 static unsigned long expire = RT_GC_TIMEOUT; 877 static unsigned long last_gc; 878 static int rover; 879 static int equilibrium; 880 struct rtable *rth; 881 struct rtable __rcu **rthp; 882 unsigned long now = jiffies; 883 int goal; 884 int entries = dst_entries_get_fast(&ipv4_dst_ops); 885 886 /* 887 * Garbage collection is pretty expensive, 888 * do not make it too frequently. 889 */ 890 891 RT_CACHE_STAT_INC(gc_total); 892 893 if (now - last_gc < ip_rt_gc_min_interval && 894 entries < ip_rt_max_size) { 895 RT_CACHE_STAT_INC(gc_ignored); 896 goto out; 897 } 898 899 entries = dst_entries_get_slow(&ipv4_dst_ops); 900 /* Calculate number of entries, which we want to expire now. */ 901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log); 902 if (goal <= 0) { 903 if (equilibrium < ipv4_dst_ops.gc_thresh) 904 equilibrium = ipv4_dst_ops.gc_thresh; 905 goal = entries - equilibrium; 906 if (goal > 0) { 907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); 908 goal = entries - equilibrium; 909 } 910 } else { 911 /* We are in dangerous area. Try to reduce cache really 912 * aggressively. 913 */ 914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1); 915 equilibrium = entries - goal; 916 } 917 918 if (now - last_gc >= ip_rt_gc_min_interval) 919 last_gc = now; 920 921 if (goal <= 0) { 922 equilibrium += goal; 923 goto work_done; 924 } 925 926 do { 927 int i, k; 928 929 for (i = rt_hash_mask, k = rover; i >= 0; i--) { 930 unsigned long tmo = expire; 931 932 k = (k + 1) & rt_hash_mask; 933 rthp = &rt_hash_table[k].chain; 934 spin_lock_bh(rt_hash_lock_addr(k)); 935 while ((rth = rcu_dereference_protected(*rthp, 936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) { 937 if (!rt_is_expired(rth) && 938 !rt_may_expire(rth, tmo, expire)) { 939 tmo >>= 1; 940 rthp = &rth->dst.rt_next; 941 continue; 942 } 943 *rthp = rth->dst.rt_next; 944 rt_free(rth); 945 goal--; 946 } 947 spin_unlock_bh(rt_hash_lock_addr(k)); 948 if (goal <= 0) 949 break; 950 } 951 rover = k; 952 953 if (goal <= 0) 954 goto work_done; 955 956 /* Goal is not achieved. We stop process if: 957 958 - if expire reduced to zero. Otherwise, expire is halfed. 959 - if table is not full. 960 - if we are called from interrupt. 961 - jiffies check is just fallback/debug loop breaker. 962 We will not spin here for long time in any case. 963 */ 964 965 RT_CACHE_STAT_INC(gc_goal_miss); 966 967 if (expire == 0) 968 break; 969 970 expire >>= 1; 971 972 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) 973 goto out; 974 } while (!in_softirq() && time_before_eq(jiffies, now)); 975 976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) 977 goto out; 978 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size) 979 goto out; 980 if (net_ratelimit()) 981 printk(KERN_WARNING "dst cache overflow\n"); 982 RT_CACHE_STAT_INC(gc_dst_overflow); 983 return 1; 984 985 work_done: 986 expire += ip_rt_gc_min_interval; 987 if (expire > ip_rt_gc_timeout || 988 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh || 989 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh) 990 expire = ip_rt_gc_timeout; 991 out: return 0; 992 } 993 994 /* 995 * Returns number of entries in a hash chain that have different hash_inputs 996 */ 997 static int slow_chain_length(const struct rtable *head) 998 { 999 int length = 0; 1000 const struct rtable *rth = head; 1001 1002 while (rth) { 1003 length += has_noalias(head, rth); 1004 rth = rcu_dereference_protected(rth->dst.rt_next, 1); 1005 } 1006 return length >> FRACT_BITS; 1007 } 1008 1009 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt, 1010 struct sk_buff *skb, int ifindex) 1011 { 1012 struct rtable *rth, *cand; 1013 struct rtable __rcu **rthp, **candp; 1014 unsigned long now; 1015 u32 min_score; 1016 int chain_length; 1017 int attempts = !in_softirq(); 1018 1019 restart: 1020 chain_length = 0; 1021 min_score = ~(u32)0; 1022 cand = NULL; 1023 candp = NULL; 1024 now = jiffies; 1025 1026 if (!rt_caching(dev_net(rt->dst.dev))) { 1027 /* 1028 * If we're not caching, just tell the caller we 1029 * were successful and don't touch the route. The 1030 * caller hold the sole reference to the cache entry, and 1031 * it will be released when the caller is done with it. 1032 * If we drop it here, the callers have no way to resolve routes 1033 * when we're not caching. Instead, just point *rp at rt, so 1034 * the caller gets a single use out of the route 1035 * Note that we do rt_free on this new route entry, so that 1036 * once its refcount hits zero, we are still able to reap it 1037 * (Thanks Alexey) 1038 * Note: To avoid expensive rcu stuff for this uncached dst, 1039 * we set DST_NOCACHE so that dst_release() can free dst without 1040 * waiting a grace period. 1041 */ 1042 1043 rt->dst.flags |= DST_NOCACHE; 1044 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { 1045 int err = arp_bind_neighbour(&rt->dst); 1046 if (err) { 1047 if (net_ratelimit()) 1048 printk(KERN_WARNING 1049 "Neighbour table failure & not caching routes.\n"); 1050 ip_rt_put(rt); 1051 return ERR_PTR(err); 1052 } 1053 } 1054 1055 goto skip_hashing; 1056 } 1057 1058 rthp = &rt_hash_table[hash].chain; 1059 1060 spin_lock_bh(rt_hash_lock_addr(hash)); 1061 while ((rth = rcu_dereference_protected(*rthp, 1062 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { 1063 if (rt_is_expired(rth)) { 1064 *rthp = rth->dst.rt_next; 1065 rt_free(rth); 1066 continue; 1067 } 1068 if (compare_keys(rth, rt) && compare_netns(rth, rt)) { 1069 /* Put it first */ 1070 *rthp = rth->dst.rt_next; 1071 /* 1072 * Since lookup is lockfree, the deletion 1073 * must be visible to another weakly ordered CPU before 1074 * the insertion at the start of the hash chain. 1075 */ 1076 rcu_assign_pointer(rth->dst.rt_next, 1077 rt_hash_table[hash].chain); 1078 /* 1079 * Since lookup is lockfree, the update writes 1080 * must be ordered for consistency on SMP. 1081 */ 1082 rcu_assign_pointer(rt_hash_table[hash].chain, rth); 1083 1084 dst_use(&rth->dst, now); 1085 spin_unlock_bh(rt_hash_lock_addr(hash)); 1086 1087 rt_drop(rt); 1088 if (skb) 1089 skb_dst_set(skb, &rth->dst); 1090 return rth; 1091 } 1092 1093 if (!atomic_read(&rth->dst.__refcnt)) { 1094 u32 score = rt_score(rth); 1095 1096 if (score <= min_score) { 1097 cand = rth; 1098 candp = rthp; 1099 min_score = score; 1100 } 1101 } 1102 1103 chain_length++; 1104 1105 rthp = &rth->dst.rt_next; 1106 } 1107 1108 if (cand) { 1109 /* ip_rt_gc_elasticity used to be average length of chain 1110 * length, when exceeded gc becomes really aggressive. 1111 * 1112 * The second limit is less certain. At the moment it allows 1113 * only 2 entries per bucket. We will see. 1114 */ 1115 if (chain_length > ip_rt_gc_elasticity) { 1116 *candp = cand->dst.rt_next; 1117 rt_free(cand); 1118 } 1119 } else { 1120 if (chain_length > rt_chain_length_max && 1121 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) { 1122 struct net *net = dev_net(rt->dst.dev); 1123 int num = ++net->ipv4.current_rt_cache_rebuild_count; 1124 if (!rt_caching(net)) { 1125 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n", 1126 rt->dst.dev->name, num); 1127 } 1128 rt_emergency_hash_rebuild(net); 1129 spin_unlock_bh(rt_hash_lock_addr(hash)); 1130 1131 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1132 ifindex, rt_genid(net)); 1133 goto restart; 1134 } 1135 } 1136 1137 /* Try to bind route to arp only if it is output 1138 route or unicast forwarding path. 1139 */ 1140 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { 1141 int err = arp_bind_neighbour(&rt->dst); 1142 if (err) { 1143 spin_unlock_bh(rt_hash_lock_addr(hash)); 1144 1145 if (err != -ENOBUFS) { 1146 rt_drop(rt); 1147 return ERR_PTR(err); 1148 } 1149 1150 /* Neighbour tables are full and nothing 1151 can be released. Try to shrink route cache, 1152 it is most likely it holds some neighbour records. 1153 */ 1154 if (attempts-- > 0) { 1155 int saved_elasticity = ip_rt_gc_elasticity; 1156 int saved_int = ip_rt_gc_min_interval; 1157 ip_rt_gc_elasticity = 1; 1158 ip_rt_gc_min_interval = 0; 1159 rt_garbage_collect(&ipv4_dst_ops); 1160 ip_rt_gc_min_interval = saved_int; 1161 ip_rt_gc_elasticity = saved_elasticity; 1162 goto restart; 1163 } 1164 1165 if (net_ratelimit()) 1166 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n"); 1167 rt_drop(rt); 1168 return ERR_PTR(-ENOBUFS); 1169 } 1170 } 1171 1172 rt->dst.rt_next = rt_hash_table[hash].chain; 1173 1174 /* 1175 * Since lookup is lockfree, we must make sure 1176 * previous writes to rt are committed to memory 1177 * before making rt visible to other CPUS. 1178 */ 1179 rcu_assign_pointer(rt_hash_table[hash].chain, rt); 1180 1181 spin_unlock_bh(rt_hash_lock_addr(hash)); 1182 1183 skip_hashing: 1184 if (skb) 1185 skb_dst_set(skb, &rt->dst); 1186 return rt; 1187 } 1188 1189 static atomic_t __rt_peer_genid = ATOMIC_INIT(0); 1190 1191 static u32 rt_peer_genid(void) 1192 { 1193 return atomic_read(&__rt_peer_genid); 1194 } 1195 1196 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create) 1197 { 1198 struct inet_peer *peer; 1199 1200 peer = inet_getpeer_v4(daddr, create); 1201 1202 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL) 1203 inet_putpeer(peer); 1204 else 1205 rt->rt_peer_genid = rt_peer_genid(); 1206 } 1207 1208 /* 1209 * Peer allocation may fail only in serious out-of-memory conditions. However 1210 * we still can generate some output. 1211 * Random ID selection looks a bit dangerous because we have no chances to 1212 * select ID being unique in a reasonable period of time. 1213 * But broken packet identifier may be better than no packet at all. 1214 */ 1215 static void ip_select_fb_ident(struct iphdr *iph) 1216 { 1217 static DEFINE_SPINLOCK(ip_fb_id_lock); 1218 static u32 ip_fallback_id; 1219 u32 salt; 1220 1221 spin_lock_bh(&ip_fb_id_lock); 1222 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); 1223 iph->id = htons(salt & 0xFFFF); 1224 ip_fallback_id = salt; 1225 spin_unlock_bh(&ip_fb_id_lock); 1226 } 1227 1228 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) 1229 { 1230 struct rtable *rt = (struct rtable *) dst; 1231 1232 if (rt) { 1233 if (rt->peer == NULL) 1234 rt_bind_peer(rt, rt->rt_dst, 1); 1235 1236 /* If peer is attached to destination, it is never detached, 1237 so that we need not to grab a lock to dereference it. 1238 */ 1239 if (rt->peer) { 1240 iph->id = htons(inet_getid(rt->peer, more)); 1241 return; 1242 } 1243 } else 1244 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", 1245 __builtin_return_address(0)); 1246 1247 ip_select_fb_ident(iph); 1248 } 1249 EXPORT_SYMBOL(__ip_select_ident); 1250 1251 static void rt_del(unsigned hash, struct rtable *rt) 1252 { 1253 struct rtable __rcu **rthp; 1254 struct rtable *aux; 1255 1256 rthp = &rt_hash_table[hash].chain; 1257 spin_lock_bh(rt_hash_lock_addr(hash)); 1258 ip_rt_put(rt); 1259 while ((aux = rcu_dereference_protected(*rthp, 1260 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { 1261 if (aux == rt || rt_is_expired(aux)) { 1262 *rthp = aux->dst.rt_next; 1263 rt_free(aux); 1264 continue; 1265 } 1266 rthp = &aux->dst.rt_next; 1267 } 1268 spin_unlock_bh(rt_hash_lock_addr(hash)); 1269 } 1270 1271 /* called in rcu_read_lock() section */ 1272 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 1273 __be32 saddr, struct net_device *dev) 1274 { 1275 struct in_device *in_dev = __in_dev_get_rcu(dev); 1276 struct inet_peer *peer; 1277 struct net *net; 1278 1279 if (!in_dev) 1280 return; 1281 1282 net = dev_net(dev); 1283 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 1284 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 1285 ipv4_is_zeronet(new_gw)) 1286 goto reject_redirect; 1287 1288 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 1289 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 1290 goto reject_redirect; 1291 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 1292 goto reject_redirect; 1293 } else { 1294 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 1295 goto reject_redirect; 1296 } 1297 1298 peer = inet_getpeer_v4(daddr, 1); 1299 if (peer) { 1300 peer->redirect_learned.a4 = new_gw; 1301 1302 inet_putpeer(peer); 1303 1304 atomic_inc(&__rt_peer_genid); 1305 } 1306 return; 1307 1308 reject_redirect: 1309 #ifdef CONFIG_IP_ROUTE_VERBOSE 1310 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 1311 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n" 1312 " Advised path = %pI4 -> %pI4\n", 1313 &old_gw, dev->name, &new_gw, 1314 &saddr, &daddr); 1315 #endif 1316 ; 1317 } 1318 1319 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 1320 { 1321 struct rtable *rt = (struct rtable *)dst; 1322 struct dst_entry *ret = dst; 1323 1324 if (rt) { 1325 if (dst->obsolete > 0) { 1326 ip_rt_put(rt); 1327 ret = NULL; 1328 } else if (rt->rt_flags & RTCF_REDIRECTED) { 1329 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1330 rt->rt_oif, 1331 rt_genid(dev_net(dst->dev))); 1332 rt_del(hash, rt); 1333 ret = NULL; 1334 } else if (rt->peer && 1335 rt->peer->pmtu_expires && 1336 time_after_eq(jiffies, rt->peer->pmtu_expires)) { 1337 unsigned long orig = rt->peer->pmtu_expires; 1338 1339 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig) 1340 dst_metric_set(dst, RTAX_MTU, 1341 rt->peer->pmtu_orig); 1342 } 1343 } 1344 return ret; 1345 } 1346 1347 /* 1348 * Algorithm: 1349 * 1. The first ip_rt_redirect_number redirects are sent 1350 * with exponential backoff, then we stop sending them at all, 1351 * assuming that the host ignores our redirects. 1352 * 2. If we did not see packets requiring redirects 1353 * during ip_rt_redirect_silence, we assume that the host 1354 * forgot redirected route and start to send redirects again. 1355 * 1356 * This algorithm is much cheaper and more intelligent than dumb load limiting 1357 * in icmp.c. 1358 * 1359 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 1360 * and "frag. need" (breaks PMTU discovery) in icmp.c. 1361 */ 1362 1363 void ip_rt_send_redirect(struct sk_buff *skb) 1364 { 1365 struct rtable *rt = skb_rtable(skb); 1366 struct in_device *in_dev; 1367 struct inet_peer *peer; 1368 int log_martians; 1369 1370 rcu_read_lock(); 1371 in_dev = __in_dev_get_rcu(rt->dst.dev); 1372 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 1373 rcu_read_unlock(); 1374 return; 1375 } 1376 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 1377 rcu_read_unlock(); 1378 1379 if (!rt->peer) 1380 rt_bind_peer(rt, rt->rt_dst, 1); 1381 peer = rt->peer; 1382 if (!peer) { 1383 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1384 return; 1385 } 1386 1387 /* No redirected packets during ip_rt_redirect_silence; 1388 * reset the algorithm. 1389 */ 1390 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 1391 peer->rate_tokens = 0; 1392 1393 /* Too many ignored redirects; do not send anything 1394 * set dst.rate_last to the last seen redirected packet. 1395 */ 1396 if (peer->rate_tokens >= ip_rt_redirect_number) { 1397 peer->rate_last = jiffies; 1398 return; 1399 } 1400 1401 /* Check for load limit; set rate_last to the latest sent 1402 * redirect. 1403 */ 1404 if (peer->rate_tokens == 0 || 1405 time_after(jiffies, 1406 (peer->rate_last + 1407 (ip_rt_redirect_load << peer->rate_tokens)))) { 1408 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1409 peer->rate_last = jiffies; 1410 ++peer->rate_tokens; 1411 #ifdef CONFIG_IP_ROUTE_VERBOSE 1412 if (log_martians && 1413 peer->rate_tokens == ip_rt_redirect_number && 1414 net_ratelimit()) 1415 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", 1416 &ip_hdr(skb)->saddr, rt->rt_iif, 1417 &rt->rt_dst, &rt->rt_gateway); 1418 #endif 1419 } 1420 } 1421 1422 static int ip_error(struct sk_buff *skb) 1423 { 1424 struct rtable *rt = skb_rtable(skb); 1425 struct inet_peer *peer; 1426 unsigned long now; 1427 bool send; 1428 int code; 1429 1430 switch (rt->dst.error) { 1431 case EINVAL: 1432 default: 1433 goto out; 1434 case EHOSTUNREACH: 1435 code = ICMP_HOST_UNREACH; 1436 break; 1437 case ENETUNREACH: 1438 code = ICMP_NET_UNREACH; 1439 IP_INC_STATS_BH(dev_net(rt->dst.dev), 1440 IPSTATS_MIB_INNOROUTES); 1441 break; 1442 case EACCES: 1443 code = ICMP_PKT_FILTERED; 1444 break; 1445 } 1446 1447 if (!rt->peer) 1448 rt_bind_peer(rt, rt->rt_dst, 1); 1449 peer = rt->peer; 1450 1451 send = true; 1452 if (peer) { 1453 now = jiffies; 1454 peer->rate_tokens += now - peer->rate_last; 1455 if (peer->rate_tokens > ip_rt_error_burst) 1456 peer->rate_tokens = ip_rt_error_burst; 1457 peer->rate_last = now; 1458 if (peer->rate_tokens >= ip_rt_error_cost) 1459 peer->rate_tokens -= ip_rt_error_cost; 1460 else 1461 send = false; 1462 } 1463 if (send) 1464 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1465 1466 out: kfree_skb(skb); 1467 return 0; 1468 } 1469 1470 /* 1471 * The last two values are not from the RFC but 1472 * are needed for AMPRnet AX.25 paths. 1473 */ 1474 1475 static const unsigned short mtu_plateau[] = 1476 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 }; 1477 1478 static inline unsigned short guess_mtu(unsigned short old_mtu) 1479 { 1480 int i; 1481 1482 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++) 1483 if (old_mtu > mtu_plateau[i]) 1484 return mtu_plateau[i]; 1485 return 68; 1486 } 1487 1488 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, 1489 unsigned short new_mtu, 1490 struct net_device *dev) 1491 { 1492 unsigned short old_mtu = ntohs(iph->tot_len); 1493 unsigned short est_mtu = 0; 1494 struct inet_peer *peer; 1495 1496 peer = inet_getpeer_v4(iph->daddr, 1); 1497 if (peer) { 1498 unsigned short mtu = new_mtu; 1499 1500 if (new_mtu < 68 || new_mtu >= old_mtu) { 1501 /* BSD 4.2 derived systems incorrectly adjust 1502 * tot_len by the IP header length, and report 1503 * a zero MTU in the ICMP message. 1504 */ 1505 if (mtu == 0 && 1506 old_mtu >= 68 + (iph->ihl << 2)) 1507 old_mtu -= iph->ihl << 2; 1508 mtu = guess_mtu(old_mtu); 1509 } 1510 1511 if (mtu < ip_rt_min_pmtu) 1512 mtu = ip_rt_min_pmtu; 1513 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { 1514 unsigned long pmtu_expires; 1515 1516 pmtu_expires = jiffies + ip_rt_mtu_expires; 1517 if (!pmtu_expires) 1518 pmtu_expires = 1UL; 1519 1520 est_mtu = mtu; 1521 peer->pmtu_learned = mtu; 1522 peer->pmtu_expires = pmtu_expires; 1523 } 1524 1525 inet_putpeer(peer); 1526 1527 atomic_inc(&__rt_peer_genid); 1528 } 1529 return est_mtu ? : new_mtu; 1530 } 1531 1532 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) 1533 { 1534 unsigned long expires = peer->pmtu_expires; 1535 1536 if (time_before(jiffies, expires)) { 1537 u32 orig_dst_mtu = dst_mtu(dst); 1538 if (peer->pmtu_learned < orig_dst_mtu) { 1539 if (!peer->pmtu_orig) 1540 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU); 1541 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned); 1542 } 1543 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires) 1544 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig); 1545 } 1546 1547 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 1548 { 1549 struct rtable *rt = (struct rtable *) dst; 1550 struct inet_peer *peer; 1551 1552 dst_confirm(dst); 1553 1554 if (!rt->peer) 1555 rt_bind_peer(rt, rt->rt_dst, 1); 1556 peer = rt->peer; 1557 if (peer) { 1558 if (mtu < ip_rt_min_pmtu) 1559 mtu = ip_rt_min_pmtu; 1560 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { 1561 unsigned long pmtu_expires; 1562 1563 pmtu_expires = jiffies + ip_rt_mtu_expires; 1564 if (!pmtu_expires) 1565 pmtu_expires = 1UL; 1566 1567 peer->pmtu_learned = mtu; 1568 peer->pmtu_expires = pmtu_expires; 1569 1570 atomic_inc(&__rt_peer_genid); 1571 rt->rt_peer_genid = rt_peer_genid(); 1572 } 1573 check_peer_pmtu(dst, peer); 1574 } 1575 } 1576 1577 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) 1578 { 1579 struct rtable *rt = (struct rtable *) dst; 1580 __be32 orig_gw = rt->rt_gateway; 1581 1582 dst_confirm(&rt->dst); 1583 1584 neigh_release(rt->dst.neighbour); 1585 rt->dst.neighbour = NULL; 1586 1587 rt->rt_gateway = peer->redirect_learned.a4; 1588 if (arp_bind_neighbour(&rt->dst) || 1589 !(rt->dst.neighbour->nud_state & NUD_VALID)) { 1590 if (rt->dst.neighbour) 1591 neigh_event_send(rt->dst.neighbour, NULL); 1592 rt->rt_gateway = orig_gw; 1593 return -EAGAIN; 1594 } else { 1595 rt->rt_flags |= RTCF_REDIRECTED; 1596 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, 1597 rt->dst.neighbour); 1598 } 1599 return 0; 1600 } 1601 1602 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1603 { 1604 struct rtable *rt = (struct rtable *) dst; 1605 1606 if (rt_is_expired(rt)) 1607 return NULL; 1608 if (rt->rt_peer_genid != rt_peer_genid()) { 1609 struct inet_peer *peer; 1610 1611 if (!rt->peer) 1612 rt_bind_peer(rt, rt->rt_dst, 0); 1613 1614 peer = rt->peer; 1615 if (peer && peer->pmtu_expires) 1616 check_peer_pmtu(dst, peer); 1617 1618 if (peer && peer->redirect_learned.a4 && 1619 peer->redirect_learned.a4 != rt->rt_gateway) { 1620 if (check_peer_redir(dst, peer)) 1621 return NULL; 1622 } 1623 1624 rt->rt_peer_genid = rt_peer_genid(); 1625 } 1626 return dst; 1627 } 1628 1629 static void ipv4_dst_destroy(struct dst_entry *dst) 1630 { 1631 struct rtable *rt = (struct rtable *) dst; 1632 struct inet_peer *peer = rt->peer; 1633 1634 if (rt->fi) { 1635 fib_info_put(rt->fi); 1636 rt->fi = NULL; 1637 } 1638 if (peer) { 1639 rt->peer = NULL; 1640 inet_putpeer(peer); 1641 } 1642 } 1643 1644 1645 static void ipv4_link_failure(struct sk_buff *skb) 1646 { 1647 struct rtable *rt; 1648 1649 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1650 1651 rt = skb_rtable(skb); 1652 if (rt && 1653 rt->peer && 1654 rt->peer->pmtu_expires) { 1655 unsigned long orig = rt->peer->pmtu_expires; 1656 1657 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig) 1658 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); 1659 } 1660 } 1661 1662 static int ip_rt_bug(struct sk_buff *skb) 1663 { 1664 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n", 1665 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1666 skb->dev ? skb->dev->name : "?"); 1667 kfree_skb(skb); 1668 return 0; 1669 } 1670 1671 /* 1672 We do not cache source address of outgoing interface, 1673 because it is used only by IP RR, TS and SRR options, 1674 so that it out of fast path. 1675 1676 BTW remember: "addr" is allowed to be not aligned 1677 in IP options! 1678 */ 1679 1680 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1681 { 1682 __be32 src; 1683 1684 if (rt_is_output_route(rt)) 1685 src = ip_hdr(skb)->saddr; 1686 else { 1687 struct fib_result res; 1688 struct flowi4 fl4; 1689 struct iphdr *iph; 1690 1691 iph = ip_hdr(skb); 1692 1693 memset(&fl4, 0, sizeof(fl4)); 1694 fl4.daddr = iph->daddr; 1695 fl4.saddr = iph->saddr; 1696 fl4.flowi4_tos = iph->tos; 1697 fl4.flowi4_oif = rt->dst.dev->ifindex; 1698 fl4.flowi4_iif = skb->dev->ifindex; 1699 fl4.flowi4_mark = skb->mark; 1700 1701 rcu_read_lock(); 1702 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1703 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1704 else 1705 src = inet_select_addr(rt->dst.dev, rt->rt_gateway, 1706 RT_SCOPE_UNIVERSE); 1707 rcu_read_unlock(); 1708 } 1709 memcpy(addr, &src, 4); 1710 } 1711 1712 #ifdef CONFIG_IP_ROUTE_CLASSID 1713 static void set_class_tag(struct rtable *rt, u32 tag) 1714 { 1715 if (!(rt->dst.tclassid & 0xFFFF)) 1716 rt->dst.tclassid |= tag & 0xFFFF; 1717 if (!(rt->dst.tclassid & 0xFFFF0000)) 1718 rt->dst.tclassid |= tag & 0xFFFF0000; 1719 } 1720 #endif 1721 1722 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1723 { 1724 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1725 1726 if (advmss == 0) { 1727 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1728 ip_rt_min_advmss); 1729 if (advmss > 65535 - 40) 1730 advmss = 65535 - 40; 1731 } 1732 return advmss; 1733 } 1734 1735 static unsigned int ipv4_default_mtu(const struct dst_entry *dst) 1736 { 1737 unsigned int mtu = dst->dev->mtu; 1738 1739 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1740 const struct rtable *rt = (const struct rtable *) dst; 1741 1742 if (rt->rt_gateway != rt->rt_dst && mtu > 576) 1743 mtu = 576; 1744 } 1745 1746 if (mtu > IP_MAX_MTU) 1747 mtu = IP_MAX_MTU; 1748 1749 return mtu; 1750 } 1751 1752 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, 1753 struct fib_info *fi) 1754 { 1755 struct inet_peer *peer; 1756 int create = 0; 1757 1758 /* If a peer entry exists for this destination, we must hook 1759 * it up in order to get at cached metrics. 1760 */ 1761 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS)) 1762 create = 1; 1763 1764 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create); 1765 if (peer) { 1766 rt->rt_peer_genid = rt_peer_genid(); 1767 if (inet_metrics_new(peer)) 1768 memcpy(peer->metrics, fi->fib_metrics, 1769 sizeof(u32) * RTAX_MAX); 1770 dst_init_metrics(&rt->dst, peer->metrics, false); 1771 1772 if (peer->pmtu_expires) 1773 check_peer_pmtu(&rt->dst, peer); 1774 if (peer->redirect_learned.a4 && 1775 peer->redirect_learned.a4 != rt->rt_gateway) { 1776 rt->rt_gateway = peer->redirect_learned.a4; 1777 rt->rt_flags |= RTCF_REDIRECTED; 1778 } 1779 } else { 1780 if (fi->fib_metrics != (u32 *) dst_default_metrics) { 1781 rt->fi = fi; 1782 atomic_inc(&fi->fib_clntref); 1783 } 1784 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1785 } 1786 } 1787 1788 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4, 1789 const struct fib_result *res, 1790 struct fib_info *fi, u16 type, u32 itag) 1791 { 1792 struct dst_entry *dst = &rt->dst; 1793 1794 if (fi) { 1795 if (FIB_RES_GW(*res) && 1796 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 1797 rt->rt_gateway = FIB_RES_GW(*res); 1798 rt_init_metrics(rt, fl4, fi); 1799 #ifdef CONFIG_IP_ROUTE_CLASSID 1800 dst->tclassid = FIB_RES_NH(*res).nh_tclassid; 1801 #endif 1802 } 1803 1804 if (dst_mtu(dst) > IP_MAX_MTU) 1805 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU); 1806 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40) 1807 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40); 1808 1809 #ifdef CONFIG_IP_ROUTE_CLASSID 1810 #ifdef CONFIG_IP_MULTIPLE_TABLES 1811 set_class_tag(rt, fib_rules_tclass(res)); 1812 #endif 1813 set_class_tag(rt, itag); 1814 #endif 1815 } 1816 1817 static struct rtable *rt_dst_alloc(struct net_device *dev, 1818 bool nopolicy, bool noxfrm) 1819 { 1820 return dst_alloc(&ipv4_dst_ops, dev, 1, -1, 1821 DST_HOST | 1822 (nopolicy ? DST_NOPOLICY : 0) | 1823 (noxfrm ? DST_NOXFRM : 0)); 1824 } 1825 1826 /* called in rcu_read_lock() section */ 1827 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1828 u8 tos, struct net_device *dev, int our) 1829 { 1830 unsigned int hash; 1831 struct rtable *rth; 1832 __be32 spec_dst; 1833 struct in_device *in_dev = __in_dev_get_rcu(dev); 1834 u32 itag = 0; 1835 int err; 1836 1837 /* Primary sanity checks. */ 1838 1839 if (in_dev == NULL) 1840 return -EINVAL; 1841 1842 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1843 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP)) 1844 goto e_inval; 1845 1846 if (ipv4_is_zeronet(saddr)) { 1847 if (!ipv4_is_local_multicast(daddr)) 1848 goto e_inval; 1849 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 1850 } else { 1851 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 1852 &itag); 1853 if (err < 0) 1854 goto e_err; 1855 } 1856 rth = rt_dst_alloc(init_net.loopback_dev, 1857 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 1858 if (!rth) 1859 goto e_nobufs; 1860 1861 #ifdef CONFIG_IP_ROUTE_CLASSID 1862 rth->dst.tclassid = itag; 1863 #endif 1864 rth->dst.output = ip_rt_bug; 1865 1866 rth->rt_key_dst = daddr; 1867 rth->rt_key_src = saddr; 1868 rth->rt_genid = rt_genid(dev_net(dev)); 1869 rth->rt_flags = RTCF_MULTICAST; 1870 rth->rt_type = RTN_MULTICAST; 1871 rth->rt_key_tos = tos; 1872 rth->rt_dst = daddr; 1873 rth->rt_src = saddr; 1874 rth->rt_route_iif = dev->ifindex; 1875 rth->rt_iif = dev->ifindex; 1876 rth->rt_oif = 0; 1877 rth->rt_mark = skb->mark; 1878 rth->rt_gateway = daddr; 1879 rth->rt_spec_dst= spec_dst; 1880 rth->rt_peer_genid = 0; 1881 rth->peer = NULL; 1882 rth->fi = NULL; 1883 if (our) { 1884 rth->dst.input= ip_local_deliver; 1885 rth->rt_flags |= RTCF_LOCAL; 1886 } 1887 1888 #ifdef CONFIG_IP_MROUTE 1889 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1890 rth->dst.input = ip_mr_input; 1891 #endif 1892 RT_CACHE_STAT_INC(in_slow_mc); 1893 1894 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); 1895 rth = rt_intern_hash(hash, rth, skb, dev->ifindex); 1896 err = 0; 1897 if (IS_ERR(rth)) 1898 err = PTR_ERR(rth); 1899 1900 e_nobufs: 1901 return -ENOBUFS; 1902 e_inval: 1903 return -EINVAL; 1904 e_err: 1905 return err; 1906 } 1907 1908 1909 static void ip_handle_martian_source(struct net_device *dev, 1910 struct in_device *in_dev, 1911 struct sk_buff *skb, 1912 __be32 daddr, 1913 __be32 saddr) 1914 { 1915 RT_CACHE_STAT_INC(in_martian_src); 1916 #ifdef CONFIG_IP_ROUTE_VERBOSE 1917 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1918 /* 1919 * RFC1812 recommendation, if source is martian, 1920 * the only hint is MAC header. 1921 */ 1922 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n", 1923 &daddr, &saddr, dev->name); 1924 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1925 int i; 1926 const unsigned char *p = skb_mac_header(skb); 1927 printk(KERN_WARNING "ll header: "); 1928 for (i = 0; i < dev->hard_header_len; i++, p++) { 1929 printk("%02x", *p); 1930 if (i < (dev->hard_header_len - 1)) 1931 printk(":"); 1932 } 1933 printk("\n"); 1934 } 1935 } 1936 #endif 1937 } 1938 1939 /* called in rcu_read_lock() section */ 1940 static int __mkroute_input(struct sk_buff *skb, 1941 const struct fib_result *res, 1942 struct in_device *in_dev, 1943 __be32 daddr, __be32 saddr, u32 tos, 1944 struct rtable **result) 1945 { 1946 struct rtable *rth; 1947 int err; 1948 struct in_device *out_dev; 1949 unsigned int flags = 0; 1950 __be32 spec_dst; 1951 u32 itag; 1952 1953 /* get a working reference to the output device */ 1954 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1955 if (out_dev == NULL) { 1956 if (net_ratelimit()) 1957 printk(KERN_CRIT "Bug in ip_route_input" \ 1958 "_slow(). Please, report\n"); 1959 return -EINVAL; 1960 } 1961 1962 1963 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1964 in_dev->dev, &spec_dst, &itag); 1965 if (err < 0) { 1966 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1967 saddr); 1968 1969 goto cleanup; 1970 } 1971 1972 if (err) 1973 flags |= RTCF_DIRECTSRC; 1974 1975 if (out_dev == in_dev && err && 1976 (IN_DEV_SHARED_MEDIA(out_dev) || 1977 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1978 flags |= RTCF_DOREDIRECT; 1979 1980 if (skb->protocol != htons(ETH_P_IP)) { 1981 /* Not IP (i.e. ARP). Do not create route, if it is 1982 * invalid for proxy arp. DNAT routes are always valid. 1983 * 1984 * Proxy arp feature have been extended to allow, ARP 1985 * replies back to the same interface, to support 1986 * Private VLAN switch technologies. See arp.c. 1987 */ 1988 if (out_dev == in_dev && 1989 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1990 err = -EINVAL; 1991 goto cleanup; 1992 } 1993 } 1994 1995 rth = rt_dst_alloc(out_dev->dev, 1996 IN_DEV_CONF_GET(in_dev, NOPOLICY), 1997 IN_DEV_CONF_GET(out_dev, NOXFRM)); 1998 if (!rth) { 1999 err = -ENOBUFS; 2000 goto cleanup; 2001 } 2002 2003 rth->rt_key_dst = daddr; 2004 rth->rt_key_src = saddr; 2005 rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); 2006 rth->rt_flags = flags; 2007 rth->rt_type = res->type; 2008 rth->rt_key_tos = tos; 2009 rth->rt_dst = daddr; 2010 rth->rt_src = saddr; 2011 rth->rt_route_iif = in_dev->dev->ifindex; 2012 rth->rt_iif = in_dev->dev->ifindex; 2013 rth->rt_oif = 0; 2014 rth->rt_mark = skb->mark; 2015 rth->rt_gateway = daddr; 2016 rth->rt_spec_dst= spec_dst; 2017 rth->rt_peer_genid = 0; 2018 rth->peer = NULL; 2019 rth->fi = NULL; 2020 2021 rth->dst.input = ip_forward; 2022 rth->dst.output = ip_output; 2023 2024 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag); 2025 2026 *result = rth; 2027 err = 0; 2028 cleanup: 2029 return err; 2030 } 2031 2032 static int ip_mkroute_input(struct sk_buff *skb, 2033 struct fib_result *res, 2034 const struct flowi4 *fl4, 2035 struct in_device *in_dev, 2036 __be32 daddr, __be32 saddr, u32 tos) 2037 { 2038 struct rtable* rth = NULL; 2039 int err; 2040 unsigned hash; 2041 2042 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2043 if (res->fi && res->fi->fib_nhs > 1) 2044 fib_select_multipath(res); 2045 #endif 2046 2047 /* create a routing cache entry */ 2048 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); 2049 if (err) 2050 return err; 2051 2052 /* put it into the cache */ 2053 hash = rt_hash(daddr, saddr, fl4->flowi4_iif, 2054 rt_genid(dev_net(rth->dst.dev))); 2055 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif); 2056 if (IS_ERR(rth)) 2057 return PTR_ERR(rth); 2058 return 0; 2059 } 2060 2061 /* 2062 * NOTE. We drop all the packets that has local source 2063 * addresses, because every properly looped back packet 2064 * must have correct destination already attached by output routine. 2065 * 2066 * Such approach solves two big problems: 2067 * 1. Not simplex devices are handled properly. 2068 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2069 * called with rcu_read_lock() 2070 */ 2071 2072 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2073 u8 tos, struct net_device *dev) 2074 { 2075 struct fib_result res; 2076 struct in_device *in_dev = __in_dev_get_rcu(dev); 2077 struct flowi4 fl4; 2078 unsigned flags = 0; 2079 u32 itag = 0; 2080 struct rtable * rth; 2081 unsigned hash; 2082 __be32 spec_dst; 2083 int err = -EINVAL; 2084 struct net * net = dev_net(dev); 2085 2086 /* IP on this device is disabled. */ 2087 2088 if (!in_dev) 2089 goto out; 2090 2091 /* Check for the most weird martians, which can be not detected 2092 by fib_lookup. 2093 */ 2094 2095 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 2096 ipv4_is_loopback(saddr)) 2097 goto martian_source; 2098 2099 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2100 goto brd_input; 2101 2102 /* Accept zero addresses only to limited broadcast; 2103 * I even do not know to fix it or not. Waiting for complains :-) 2104 */ 2105 if (ipv4_is_zeronet(saddr)) 2106 goto martian_source; 2107 2108 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr)) 2109 goto martian_destination; 2110 2111 /* 2112 * Now we are ready to route packet. 2113 */ 2114 fl4.flowi4_oif = 0; 2115 fl4.flowi4_iif = dev->ifindex; 2116 fl4.flowi4_mark = skb->mark; 2117 fl4.flowi4_tos = tos; 2118 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2119 fl4.daddr = daddr; 2120 fl4.saddr = saddr; 2121 err = fib_lookup(net, &fl4, &res); 2122 if (err != 0) { 2123 if (!IN_DEV_FORWARD(in_dev)) 2124 goto e_hostunreach; 2125 goto no_route; 2126 } 2127 2128 RT_CACHE_STAT_INC(in_slow_tot); 2129 2130 if (res.type == RTN_BROADCAST) 2131 goto brd_input; 2132 2133 if (res.type == RTN_LOCAL) { 2134 err = fib_validate_source(skb, saddr, daddr, tos, 2135 net->loopback_dev->ifindex, 2136 dev, &spec_dst, &itag); 2137 if (err < 0) 2138 goto martian_source_keep_err; 2139 if (err) 2140 flags |= RTCF_DIRECTSRC; 2141 spec_dst = daddr; 2142 goto local_input; 2143 } 2144 2145 if (!IN_DEV_FORWARD(in_dev)) 2146 goto e_hostunreach; 2147 if (res.type != RTN_UNICAST) 2148 goto martian_destination; 2149 2150 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 2151 out: return err; 2152 2153 brd_input: 2154 if (skb->protocol != htons(ETH_P_IP)) 2155 goto e_inval; 2156 2157 if (ipv4_is_zeronet(saddr)) 2158 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 2159 else { 2160 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 2161 &itag); 2162 if (err < 0) 2163 goto martian_source_keep_err; 2164 if (err) 2165 flags |= RTCF_DIRECTSRC; 2166 } 2167 flags |= RTCF_BROADCAST; 2168 res.type = RTN_BROADCAST; 2169 RT_CACHE_STAT_INC(in_brd); 2170 2171 local_input: 2172 rth = rt_dst_alloc(net->loopback_dev, 2173 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 2174 if (!rth) 2175 goto e_nobufs; 2176 2177 rth->dst.input= ip_local_deliver; 2178 rth->dst.output= ip_rt_bug; 2179 #ifdef CONFIG_IP_ROUTE_CLASSID 2180 rth->dst.tclassid = itag; 2181 #endif 2182 2183 rth->rt_key_dst = daddr; 2184 rth->rt_key_src = saddr; 2185 rth->rt_genid = rt_genid(net); 2186 rth->rt_flags = flags|RTCF_LOCAL; 2187 rth->rt_type = res.type; 2188 rth->rt_key_tos = tos; 2189 rth->rt_dst = daddr; 2190 rth->rt_src = saddr; 2191 #ifdef CONFIG_IP_ROUTE_CLASSID 2192 rth->dst.tclassid = itag; 2193 #endif 2194 rth->rt_route_iif = dev->ifindex; 2195 rth->rt_iif = dev->ifindex; 2196 rth->rt_oif = 0; 2197 rth->rt_mark = skb->mark; 2198 rth->rt_gateway = daddr; 2199 rth->rt_spec_dst= spec_dst; 2200 rth->rt_peer_genid = 0; 2201 rth->peer = NULL; 2202 rth->fi = NULL; 2203 if (res.type == RTN_UNREACHABLE) { 2204 rth->dst.input= ip_error; 2205 rth->dst.error= -err; 2206 rth->rt_flags &= ~RTCF_LOCAL; 2207 } 2208 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net)); 2209 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif); 2210 err = 0; 2211 if (IS_ERR(rth)) 2212 err = PTR_ERR(rth); 2213 goto out; 2214 2215 no_route: 2216 RT_CACHE_STAT_INC(in_no_route); 2217 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 2218 res.type = RTN_UNREACHABLE; 2219 if (err == -ESRCH) 2220 err = -ENETUNREACH; 2221 goto local_input; 2222 2223 /* 2224 * Do not cache martian addresses: they should be logged (RFC1812) 2225 */ 2226 martian_destination: 2227 RT_CACHE_STAT_INC(in_martian_dst); 2228 #ifdef CONFIG_IP_ROUTE_VERBOSE 2229 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 2230 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n", 2231 &daddr, &saddr, dev->name); 2232 #endif 2233 2234 e_hostunreach: 2235 err = -EHOSTUNREACH; 2236 goto out; 2237 2238 e_inval: 2239 err = -EINVAL; 2240 goto out; 2241 2242 e_nobufs: 2243 err = -ENOBUFS; 2244 goto out; 2245 2246 martian_source: 2247 err = -EINVAL; 2248 martian_source_keep_err: 2249 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2250 goto out; 2251 } 2252 2253 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2254 u8 tos, struct net_device *dev, bool noref) 2255 { 2256 struct rtable * rth; 2257 unsigned hash; 2258 int iif = dev->ifindex; 2259 struct net *net; 2260 int res; 2261 2262 net = dev_net(dev); 2263 2264 rcu_read_lock(); 2265 2266 if (!rt_caching(net)) 2267 goto skip_cache; 2268 2269 tos &= IPTOS_RT_MASK; 2270 hash = rt_hash(daddr, saddr, iif, rt_genid(net)); 2271 2272 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 2273 rth = rcu_dereference(rth->dst.rt_next)) { 2274 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) | 2275 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) | 2276 (rth->rt_iif ^ iif) | 2277 rth->rt_oif | 2278 (rth->rt_key_tos ^ tos)) == 0 && 2279 rth->rt_mark == skb->mark && 2280 net_eq(dev_net(rth->dst.dev), net) && 2281 !rt_is_expired(rth)) { 2282 if (noref) { 2283 dst_use_noref(&rth->dst, jiffies); 2284 skb_dst_set_noref(skb, &rth->dst); 2285 } else { 2286 dst_use(&rth->dst, jiffies); 2287 skb_dst_set(skb, &rth->dst); 2288 } 2289 RT_CACHE_STAT_INC(in_hit); 2290 rcu_read_unlock(); 2291 return 0; 2292 } 2293 RT_CACHE_STAT_INC(in_hlist_search); 2294 } 2295 2296 skip_cache: 2297 /* Multicast recognition logic is moved from route cache to here. 2298 The problem was that too many Ethernet cards have broken/missing 2299 hardware multicast filters :-( As result the host on multicasting 2300 network acquires a lot of useless route cache entries, sort of 2301 SDR messages from all the world. Now we try to get rid of them. 2302 Really, provided software IP multicast filter is organized 2303 reasonably (at least, hashed), it does not result in a slowdown 2304 comparing with route cache reject entries. 2305 Note, that multicast routers are not affected, because 2306 route cache entry is created eventually. 2307 */ 2308 if (ipv4_is_multicast(daddr)) { 2309 struct in_device *in_dev = __in_dev_get_rcu(dev); 2310 2311 if (in_dev) { 2312 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 2313 ip_hdr(skb)->protocol); 2314 if (our 2315 #ifdef CONFIG_IP_MROUTE 2316 || 2317 (!ipv4_is_local_multicast(daddr) && 2318 IN_DEV_MFORWARD(in_dev)) 2319 #endif 2320 ) { 2321 int res = ip_route_input_mc(skb, daddr, saddr, 2322 tos, dev, our); 2323 rcu_read_unlock(); 2324 return res; 2325 } 2326 } 2327 rcu_read_unlock(); 2328 return -EINVAL; 2329 } 2330 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 2331 rcu_read_unlock(); 2332 return res; 2333 } 2334 EXPORT_SYMBOL(ip_route_input_common); 2335 2336 /* called with rcu_read_lock() */ 2337 static struct rtable *__mkroute_output(const struct fib_result *res, 2338 const struct flowi4 *fl4, 2339 __be32 orig_daddr, __be32 orig_saddr, 2340 int orig_oif, struct net_device *dev_out, 2341 unsigned int flags) 2342 { 2343 struct fib_info *fi = res->fi; 2344 u32 tos = RT_FL_TOS(fl4); 2345 struct in_device *in_dev; 2346 u16 type = res->type; 2347 struct rtable *rth; 2348 2349 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 2350 return ERR_PTR(-EINVAL); 2351 2352 if (ipv4_is_lbcast(fl4->daddr)) 2353 type = RTN_BROADCAST; 2354 else if (ipv4_is_multicast(fl4->daddr)) 2355 type = RTN_MULTICAST; 2356 else if (ipv4_is_zeronet(fl4->daddr)) 2357 return ERR_PTR(-EINVAL); 2358 2359 if (dev_out->flags & IFF_LOOPBACK) 2360 flags |= RTCF_LOCAL; 2361 2362 in_dev = __in_dev_get_rcu(dev_out); 2363 if (!in_dev) 2364 return ERR_PTR(-EINVAL); 2365 2366 if (type == RTN_BROADCAST) { 2367 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2368 fi = NULL; 2369 } else if (type == RTN_MULTICAST) { 2370 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2371 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2372 fl4->flowi4_proto)) 2373 flags &= ~RTCF_LOCAL; 2374 /* If multicast route do not exist use 2375 * default one, but do not gateway in this case. 2376 * Yes, it is hack. 2377 */ 2378 if (fi && res->prefixlen < 4) 2379 fi = NULL; 2380 } 2381 2382 rth = rt_dst_alloc(dev_out, 2383 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2384 IN_DEV_CONF_GET(in_dev, NOXFRM)); 2385 if (!rth) 2386 return ERR_PTR(-ENOBUFS); 2387 2388 rth->dst.output = ip_output; 2389 2390 rth->rt_key_dst = orig_daddr; 2391 rth->rt_key_src = orig_saddr; 2392 rth->rt_genid = rt_genid(dev_net(dev_out)); 2393 rth->rt_flags = flags; 2394 rth->rt_type = type; 2395 rth->rt_key_tos = tos; 2396 rth->rt_dst = fl4->daddr; 2397 rth->rt_src = fl4->saddr; 2398 rth->rt_route_iif = 0; 2399 rth->rt_iif = orig_oif ? : dev_out->ifindex; 2400 rth->rt_oif = orig_oif; 2401 rth->rt_mark = fl4->flowi4_mark; 2402 rth->rt_gateway = fl4->daddr; 2403 rth->rt_spec_dst= fl4->saddr; 2404 rth->rt_peer_genid = 0; 2405 rth->peer = NULL; 2406 rth->fi = NULL; 2407 2408 RT_CACHE_STAT_INC(out_slow_tot); 2409 2410 if (flags & RTCF_LOCAL) { 2411 rth->dst.input = ip_local_deliver; 2412 rth->rt_spec_dst = fl4->daddr; 2413 } 2414 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2415 rth->rt_spec_dst = fl4->saddr; 2416 if (flags & RTCF_LOCAL && 2417 !(dev_out->flags & IFF_LOOPBACK)) { 2418 rth->dst.output = ip_mc_output; 2419 RT_CACHE_STAT_INC(out_slow_mc); 2420 } 2421 #ifdef CONFIG_IP_MROUTE 2422 if (type == RTN_MULTICAST) { 2423 if (IN_DEV_MFORWARD(in_dev) && 2424 !ipv4_is_local_multicast(fl4->daddr)) { 2425 rth->dst.input = ip_mr_input; 2426 rth->dst.output = ip_mc_output; 2427 } 2428 } 2429 #endif 2430 } 2431 2432 rt_set_nexthop(rth, fl4, res, fi, type, 0); 2433 2434 return rth; 2435 } 2436 2437 /* 2438 * Major route resolver routine. 2439 * called with rcu_read_lock(); 2440 */ 2441 2442 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) 2443 { 2444 struct net_device *dev_out = NULL; 2445 u32 tos = RT_FL_TOS(fl4); 2446 unsigned int flags = 0; 2447 struct fib_result res; 2448 struct rtable *rth; 2449 __be32 orig_daddr; 2450 __be32 orig_saddr; 2451 int orig_oif; 2452 2453 res.fi = NULL; 2454 #ifdef CONFIG_IP_MULTIPLE_TABLES 2455 res.r = NULL; 2456 #endif 2457 2458 orig_daddr = fl4->daddr; 2459 orig_saddr = fl4->saddr; 2460 orig_oif = fl4->flowi4_oif; 2461 2462 fl4->flowi4_iif = net->loopback_dev->ifindex; 2463 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2464 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2465 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2466 2467 rcu_read_lock(); 2468 if (fl4->saddr) { 2469 rth = ERR_PTR(-EINVAL); 2470 if (ipv4_is_multicast(fl4->saddr) || 2471 ipv4_is_lbcast(fl4->saddr) || 2472 ipv4_is_zeronet(fl4->saddr)) 2473 goto out; 2474 2475 /* I removed check for oif == dev_out->oif here. 2476 It was wrong for two reasons: 2477 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2478 is assigned to multiple interfaces. 2479 2. Moreover, we are allowed to send packets with saddr 2480 of another iface. --ANK 2481 */ 2482 2483 if (fl4->flowi4_oif == 0 && 2484 (ipv4_is_multicast(fl4->daddr) || 2485 ipv4_is_lbcast(fl4->daddr))) { 2486 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2487 dev_out = __ip_dev_find(net, fl4->saddr, false); 2488 if (dev_out == NULL) 2489 goto out; 2490 2491 /* Special hack: user can direct multicasts 2492 and limited broadcast via necessary interface 2493 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2494 This hack is not just for fun, it allows 2495 vic,vat and friends to work. 2496 They bind socket to loopback, set ttl to zero 2497 and expect that it will work. 2498 From the viewpoint of routing cache they are broken, 2499 because we are not allowed to build multicast path 2500 with loopback source addr (look, routing cache 2501 cannot know, that ttl is zero, so that packet 2502 will not leave this host and route is valid). 2503 Luckily, this hack is good workaround. 2504 */ 2505 2506 fl4->flowi4_oif = dev_out->ifindex; 2507 goto make_route; 2508 } 2509 2510 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2511 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2512 if (!__ip_dev_find(net, fl4->saddr, false)) 2513 goto out; 2514 } 2515 } 2516 2517 2518 if (fl4->flowi4_oif) { 2519 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2520 rth = ERR_PTR(-ENODEV); 2521 if (dev_out == NULL) 2522 goto out; 2523 2524 /* RACE: Check return value of inet_select_addr instead. */ 2525 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2526 rth = ERR_PTR(-ENETUNREACH); 2527 goto out; 2528 } 2529 if (ipv4_is_local_multicast(fl4->daddr) || 2530 ipv4_is_lbcast(fl4->daddr)) { 2531 if (!fl4->saddr) 2532 fl4->saddr = inet_select_addr(dev_out, 0, 2533 RT_SCOPE_LINK); 2534 goto make_route; 2535 } 2536 if (fl4->saddr) { 2537 if (ipv4_is_multicast(fl4->daddr)) 2538 fl4->saddr = inet_select_addr(dev_out, 0, 2539 fl4->flowi4_scope); 2540 else if (!fl4->daddr) 2541 fl4->saddr = inet_select_addr(dev_out, 0, 2542 RT_SCOPE_HOST); 2543 } 2544 } 2545 2546 if (!fl4->daddr) { 2547 fl4->daddr = fl4->saddr; 2548 if (!fl4->daddr) 2549 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2550 dev_out = net->loopback_dev; 2551 fl4->flowi4_oif = net->loopback_dev->ifindex; 2552 res.type = RTN_LOCAL; 2553 flags |= RTCF_LOCAL; 2554 goto make_route; 2555 } 2556 2557 if (fib_lookup(net, fl4, &res)) { 2558 res.fi = NULL; 2559 if (fl4->flowi4_oif) { 2560 /* Apparently, routing tables are wrong. Assume, 2561 that the destination is on link. 2562 2563 WHY? DW. 2564 Because we are allowed to send to iface 2565 even if it has NO routes and NO assigned 2566 addresses. When oif is specified, routing 2567 tables are looked up with only one purpose: 2568 to catch if destination is gatewayed, rather than 2569 direct. Moreover, if MSG_DONTROUTE is set, 2570 we send packet, ignoring both routing tables 2571 and ifaddr state. --ANK 2572 2573 2574 We could make it even if oif is unknown, 2575 likely IPv6, but we do not. 2576 */ 2577 2578 if (fl4->saddr == 0) 2579 fl4->saddr = inet_select_addr(dev_out, 0, 2580 RT_SCOPE_LINK); 2581 res.type = RTN_UNICAST; 2582 goto make_route; 2583 } 2584 rth = ERR_PTR(-ENETUNREACH); 2585 goto out; 2586 } 2587 2588 if (res.type == RTN_LOCAL) { 2589 if (!fl4->saddr) { 2590 if (res.fi->fib_prefsrc) 2591 fl4->saddr = res.fi->fib_prefsrc; 2592 else 2593 fl4->saddr = fl4->daddr; 2594 } 2595 dev_out = net->loopback_dev; 2596 fl4->flowi4_oif = dev_out->ifindex; 2597 res.fi = NULL; 2598 flags |= RTCF_LOCAL; 2599 goto make_route; 2600 } 2601 2602 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2603 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2604 fib_select_multipath(&res); 2605 else 2606 #endif 2607 if (!res.prefixlen && 2608 res.table->tb_num_default > 1 && 2609 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2610 fib_select_default(&res); 2611 2612 if (!fl4->saddr) 2613 fl4->saddr = FIB_RES_PREFSRC(net, res); 2614 2615 dev_out = FIB_RES_DEV(res); 2616 fl4->flowi4_oif = dev_out->ifindex; 2617 2618 2619 make_route: 2620 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif, 2621 dev_out, flags); 2622 if (!IS_ERR(rth)) { 2623 unsigned int hash; 2624 2625 hash = rt_hash(orig_daddr, orig_saddr, orig_oif, 2626 rt_genid(dev_net(dev_out))); 2627 rth = rt_intern_hash(hash, rth, NULL, orig_oif); 2628 } 2629 2630 out: 2631 rcu_read_unlock(); 2632 return rth; 2633 } 2634 2635 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) 2636 { 2637 struct rtable *rth; 2638 unsigned int hash; 2639 2640 if (!rt_caching(net)) 2641 goto slow_output; 2642 2643 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net)); 2644 2645 rcu_read_lock_bh(); 2646 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; 2647 rth = rcu_dereference_bh(rth->dst.rt_next)) { 2648 if (rth->rt_key_dst == flp4->daddr && 2649 rth->rt_key_src == flp4->saddr && 2650 rt_is_output_route(rth) && 2651 rth->rt_oif == flp4->flowi4_oif && 2652 rth->rt_mark == flp4->flowi4_mark && 2653 !((rth->rt_key_tos ^ flp4->flowi4_tos) & 2654 (IPTOS_RT_MASK | RTO_ONLINK)) && 2655 net_eq(dev_net(rth->dst.dev), net) && 2656 !rt_is_expired(rth)) { 2657 dst_use(&rth->dst, jiffies); 2658 RT_CACHE_STAT_INC(out_hit); 2659 rcu_read_unlock_bh(); 2660 if (!flp4->saddr) 2661 flp4->saddr = rth->rt_src; 2662 if (!flp4->daddr) 2663 flp4->daddr = rth->rt_dst; 2664 return rth; 2665 } 2666 RT_CACHE_STAT_INC(out_hlist_search); 2667 } 2668 rcu_read_unlock_bh(); 2669 2670 slow_output: 2671 return ip_route_output_slow(net, flp4); 2672 } 2673 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2674 2675 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2676 { 2677 return NULL; 2678 } 2679 2680 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst) 2681 { 2682 return 0; 2683 } 2684 2685 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) 2686 { 2687 } 2688 2689 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2690 unsigned long old) 2691 { 2692 return NULL; 2693 } 2694 2695 static struct dst_ops ipv4_dst_blackhole_ops = { 2696 .family = AF_INET, 2697 .protocol = cpu_to_be16(ETH_P_IP), 2698 .destroy = ipv4_dst_destroy, 2699 .check = ipv4_blackhole_dst_check, 2700 .default_mtu = ipv4_blackhole_default_mtu, 2701 .default_advmss = ipv4_default_advmss, 2702 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2703 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2704 }; 2705 2706 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2707 { 2708 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0); 2709 struct rtable *ort = (struct rtable *) dst_orig; 2710 2711 if (rt) { 2712 struct dst_entry *new = &rt->dst; 2713 2714 new->__use = 1; 2715 new->input = dst_discard; 2716 new->output = dst_discard; 2717 dst_copy_metrics(new, &ort->dst); 2718 2719 new->dev = ort->dst.dev; 2720 if (new->dev) 2721 dev_hold(new->dev); 2722 2723 rt->rt_key_dst = ort->rt_key_dst; 2724 rt->rt_key_src = ort->rt_key_src; 2725 rt->rt_key_tos = ort->rt_key_tos; 2726 rt->rt_route_iif = ort->rt_route_iif; 2727 rt->rt_iif = ort->rt_iif; 2728 rt->rt_oif = ort->rt_oif; 2729 rt->rt_mark = ort->rt_mark; 2730 2731 rt->rt_genid = rt_genid(net); 2732 rt->rt_flags = ort->rt_flags; 2733 rt->rt_type = ort->rt_type; 2734 rt->rt_dst = ort->rt_dst; 2735 rt->rt_src = ort->rt_src; 2736 rt->rt_gateway = ort->rt_gateway; 2737 rt->rt_spec_dst = ort->rt_spec_dst; 2738 rt->peer = ort->peer; 2739 if (rt->peer) 2740 atomic_inc(&rt->peer->refcnt); 2741 rt->fi = ort->fi; 2742 if (rt->fi) 2743 atomic_inc(&rt->fi->fib_clntref); 2744 2745 dst_free(new); 2746 } 2747 2748 dst_release(dst_orig); 2749 2750 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2751 } 2752 2753 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2754 struct sock *sk) 2755 { 2756 struct rtable *rt = __ip_route_output_key(net, flp4); 2757 2758 if (IS_ERR(rt)) 2759 return rt; 2760 2761 if (flp4->flowi4_proto) 2762 rt = (struct rtable *) xfrm_lookup(net, &rt->dst, 2763 flowi4_to_flowi(flp4), 2764 sk, 0); 2765 2766 return rt; 2767 } 2768 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2769 2770 static int rt_fill_info(struct net *net, 2771 struct sk_buff *skb, u32 pid, u32 seq, int event, 2772 int nowait, unsigned int flags) 2773 { 2774 struct rtable *rt = skb_rtable(skb); 2775 struct rtmsg *r; 2776 struct nlmsghdr *nlh; 2777 long expires; 2778 u32 id = 0, ts = 0, tsage = 0, error; 2779 2780 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); 2781 if (nlh == NULL) 2782 return -EMSGSIZE; 2783 2784 r = nlmsg_data(nlh); 2785 r->rtm_family = AF_INET; 2786 r->rtm_dst_len = 32; 2787 r->rtm_src_len = 0; 2788 r->rtm_tos = rt->rt_key_tos; 2789 r->rtm_table = RT_TABLE_MAIN; 2790 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN); 2791 r->rtm_type = rt->rt_type; 2792 r->rtm_scope = RT_SCOPE_UNIVERSE; 2793 r->rtm_protocol = RTPROT_UNSPEC; 2794 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2795 if (rt->rt_flags & RTCF_NOTIFY) 2796 r->rtm_flags |= RTM_F_NOTIFY; 2797 2798 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst); 2799 2800 if (rt->rt_key_src) { 2801 r->rtm_src_len = 32; 2802 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src); 2803 } 2804 if (rt->dst.dev) 2805 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex); 2806 #ifdef CONFIG_IP_ROUTE_CLASSID 2807 if (rt->dst.tclassid) 2808 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid); 2809 #endif 2810 if (rt_is_input_route(rt)) 2811 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); 2812 else if (rt->rt_src != rt->rt_key_src) 2813 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src); 2814 2815 if (rt->rt_dst != rt->rt_gateway) 2816 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway); 2817 2818 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 2819 goto nla_put_failure; 2820 2821 if (rt->rt_mark) 2822 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark); 2823 2824 error = rt->dst.error; 2825 expires = (rt->peer && rt->peer->pmtu_expires) ? 2826 rt->peer->pmtu_expires - jiffies : 0; 2827 if (rt->peer) { 2828 inet_peer_refcheck(rt->peer); 2829 id = atomic_read(&rt->peer->ip_id_count) & 0xffff; 2830 if (rt->peer->tcp_ts_stamp) { 2831 ts = rt->peer->tcp_ts; 2832 tsage = get_seconds() - rt->peer->tcp_ts_stamp; 2833 } 2834 } 2835 2836 if (rt_is_input_route(rt)) { 2837 #ifdef CONFIG_IP_MROUTE 2838 __be32 dst = rt->rt_dst; 2839 2840 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2841 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2842 int err = ipmr_get_route(net, skb, 2843 rt->rt_src, rt->rt_dst, 2844 r, nowait); 2845 if (err <= 0) { 2846 if (!nowait) { 2847 if (err == 0) 2848 return 0; 2849 goto nla_put_failure; 2850 } else { 2851 if (err == -EMSGSIZE) 2852 goto nla_put_failure; 2853 error = err; 2854 } 2855 } 2856 } else 2857 #endif 2858 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif); 2859 } 2860 2861 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage, 2862 expires, error) < 0) 2863 goto nla_put_failure; 2864 2865 return nlmsg_end(skb, nlh); 2866 2867 nla_put_failure: 2868 nlmsg_cancel(skb, nlh); 2869 return -EMSGSIZE; 2870 } 2871 2872 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2873 { 2874 struct net *net = sock_net(in_skb->sk); 2875 struct rtmsg *rtm; 2876 struct nlattr *tb[RTA_MAX+1]; 2877 struct rtable *rt = NULL; 2878 __be32 dst = 0; 2879 __be32 src = 0; 2880 u32 iif; 2881 int err; 2882 int mark; 2883 struct sk_buff *skb; 2884 2885 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2886 if (err < 0) 2887 goto errout; 2888 2889 rtm = nlmsg_data(nlh); 2890 2891 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2892 if (skb == NULL) { 2893 err = -ENOBUFS; 2894 goto errout; 2895 } 2896 2897 /* Reserve room for dummy headers, this skb can pass 2898 through good chunk of routing engine. 2899 */ 2900 skb_reset_mac_header(skb); 2901 skb_reset_network_header(skb); 2902 2903 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2904 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2905 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2906 2907 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2908 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2909 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2910 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2911 2912 if (iif) { 2913 struct net_device *dev; 2914 2915 dev = __dev_get_by_index(net, iif); 2916 if (dev == NULL) { 2917 err = -ENODEV; 2918 goto errout_free; 2919 } 2920 2921 skb->protocol = htons(ETH_P_IP); 2922 skb->dev = dev; 2923 skb->mark = mark; 2924 local_bh_disable(); 2925 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2926 local_bh_enable(); 2927 2928 rt = skb_rtable(skb); 2929 if (err == 0 && rt->dst.error) 2930 err = -rt->dst.error; 2931 } else { 2932 struct flowi4 fl4 = { 2933 .daddr = dst, 2934 .saddr = src, 2935 .flowi4_tos = rtm->rtm_tos, 2936 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, 2937 .flowi4_mark = mark, 2938 }; 2939 rt = ip_route_output_key(net, &fl4); 2940 2941 err = 0; 2942 if (IS_ERR(rt)) 2943 err = PTR_ERR(rt); 2944 } 2945 2946 if (err) 2947 goto errout_free; 2948 2949 skb_dst_set(skb, &rt->dst); 2950 if (rtm->rtm_flags & RTM_F_NOTIFY) 2951 rt->rt_flags |= RTCF_NOTIFY; 2952 2953 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 2954 RTM_NEWROUTE, 0, 0); 2955 if (err <= 0) 2956 goto errout_free; 2957 2958 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); 2959 errout: 2960 return err; 2961 2962 errout_free: 2963 kfree_skb(skb); 2964 goto errout; 2965 } 2966 2967 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) 2968 { 2969 struct rtable *rt; 2970 int h, s_h; 2971 int idx, s_idx; 2972 struct net *net; 2973 2974 net = sock_net(skb->sk); 2975 2976 s_h = cb->args[0]; 2977 if (s_h < 0) 2978 s_h = 0; 2979 s_idx = idx = cb->args[1]; 2980 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { 2981 if (!rt_hash_table[h].chain) 2982 continue; 2983 rcu_read_lock_bh(); 2984 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; 2985 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) { 2986 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx) 2987 continue; 2988 if (rt_is_expired(rt)) 2989 continue; 2990 skb_dst_set_noref(skb, &rt->dst); 2991 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, 2992 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 2993 1, NLM_F_MULTI) <= 0) { 2994 skb_dst_drop(skb); 2995 rcu_read_unlock_bh(); 2996 goto done; 2997 } 2998 skb_dst_drop(skb); 2999 } 3000 rcu_read_unlock_bh(); 3001 } 3002 3003 done: 3004 cb->args[0] = h; 3005 cb->args[1] = idx; 3006 return skb->len; 3007 } 3008 3009 void ip_rt_multicast_event(struct in_device *in_dev) 3010 { 3011 rt_cache_flush(dev_net(in_dev->dev), 0); 3012 } 3013 3014 #ifdef CONFIG_SYSCTL 3015 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, 3016 void __user *buffer, 3017 size_t *lenp, loff_t *ppos) 3018 { 3019 if (write) { 3020 int flush_delay; 3021 ctl_table ctl; 3022 struct net *net; 3023 3024 memcpy(&ctl, __ctl, sizeof(ctl)); 3025 ctl.data = &flush_delay; 3026 proc_dointvec(&ctl, write, buffer, lenp, ppos); 3027 3028 net = (struct net *)__ctl->extra1; 3029 rt_cache_flush(net, flush_delay); 3030 return 0; 3031 } 3032 3033 return -EINVAL; 3034 } 3035 3036 static ctl_table ipv4_route_table[] = { 3037 { 3038 .procname = "gc_thresh", 3039 .data = &ipv4_dst_ops.gc_thresh, 3040 .maxlen = sizeof(int), 3041 .mode = 0644, 3042 .proc_handler = proc_dointvec, 3043 }, 3044 { 3045 .procname = "max_size", 3046 .data = &ip_rt_max_size, 3047 .maxlen = sizeof(int), 3048 .mode = 0644, 3049 .proc_handler = proc_dointvec, 3050 }, 3051 { 3052 /* Deprecated. Use gc_min_interval_ms */ 3053 3054 .procname = "gc_min_interval", 3055 .data = &ip_rt_gc_min_interval, 3056 .maxlen = sizeof(int), 3057 .mode = 0644, 3058 .proc_handler = proc_dointvec_jiffies, 3059 }, 3060 { 3061 .procname = "gc_min_interval_ms", 3062 .data = &ip_rt_gc_min_interval, 3063 .maxlen = sizeof(int), 3064 .mode = 0644, 3065 .proc_handler = proc_dointvec_ms_jiffies, 3066 }, 3067 { 3068 .procname = "gc_timeout", 3069 .data = &ip_rt_gc_timeout, 3070 .maxlen = sizeof(int), 3071 .mode = 0644, 3072 .proc_handler = proc_dointvec_jiffies, 3073 }, 3074 { 3075 .procname = "gc_interval", 3076 .data = &ip_rt_gc_interval, 3077 .maxlen = sizeof(int), 3078 .mode = 0644, 3079 .proc_handler = proc_dointvec_jiffies, 3080 }, 3081 { 3082 .procname = "redirect_load", 3083 .data = &ip_rt_redirect_load, 3084 .maxlen = sizeof(int), 3085 .mode = 0644, 3086 .proc_handler = proc_dointvec, 3087 }, 3088 { 3089 .procname = "redirect_number", 3090 .data = &ip_rt_redirect_number, 3091 .maxlen = sizeof(int), 3092 .mode = 0644, 3093 .proc_handler = proc_dointvec, 3094 }, 3095 { 3096 .procname = "redirect_silence", 3097 .data = &ip_rt_redirect_silence, 3098 .maxlen = sizeof(int), 3099 .mode = 0644, 3100 .proc_handler = proc_dointvec, 3101 }, 3102 { 3103 .procname = "error_cost", 3104 .data = &ip_rt_error_cost, 3105 .maxlen = sizeof(int), 3106 .mode = 0644, 3107 .proc_handler = proc_dointvec, 3108 }, 3109 { 3110 .procname = "error_burst", 3111 .data = &ip_rt_error_burst, 3112 .maxlen = sizeof(int), 3113 .mode = 0644, 3114 .proc_handler = proc_dointvec, 3115 }, 3116 { 3117 .procname = "gc_elasticity", 3118 .data = &ip_rt_gc_elasticity, 3119 .maxlen = sizeof(int), 3120 .mode = 0644, 3121 .proc_handler = proc_dointvec, 3122 }, 3123 { 3124 .procname = "mtu_expires", 3125 .data = &ip_rt_mtu_expires, 3126 .maxlen = sizeof(int), 3127 .mode = 0644, 3128 .proc_handler = proc_dointvec_jiffies, 3129 }, 3130 { 3131 .procname = "min_pmtu", 3132 .data = &ip_rt_min_pmtu, 3133 .maxlen = sizeof(int), 3134 .mode = 0644, 3135 .proc_handler = proc_dointvec, 3136 }, 3137 { 3138 .procname = "min_adv_mss", 3139 .data = &ip_rt_min_advmss, 3140 .maxlen = sizeof(int), 3141 .mode = 0644, 3142 .proc_handler = proc_dointvec, 3143 }, 3144 { } 3145 }; 3146 3147 static struct ctl_table empty[1]; 3148 3149 static struct ctl_table ipv4_skeleton[] = 3150 { 3151 { .procname = "route", 3152 .mode = 0555, .child = ipv4_route_table}, 3153 { .procname = "neigh", 3154 .mode = 0555, .child = empty}, 3155 { } 3156 }; 3157 3158 static __net_initdata struct ctl_path ipv4_path[] = { 3159 { .procname = "net", }, 3160 { .procname = "ipv4", }, 3161 { }, 3162 }; 3163 3164 static struct ctl_table ipv4_route_flush_table[] = { 3165 { 3166 .procname = "flush", 3167 .maxlen = sizeof(int), 3168 .mode = 0200, 3169 .proc_handler = ipv4_sysctl_rtcache_flush, 3170 }, 3171 { }, 3172 }; 3173 3174 static __net_initdata struct ctl_path ipv4_route_path[] = { 3175 { .procname = "net", }, 3176 { .procname = "ipv4", }, 3177 { .procname = "route", }, 3178 { }, 3179 }; 3180 3181 static __net_init int sysctl_route_net_init(struct net *net) 3182 { 3183 struct ctl_table *tbl; 3184 3185 tbl = ipv4_route_flush_table; 3186 if (!net_eq(net, &init_net)) { 3187 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3188 if (tbl == NULL) 3189 goto err_dup; 3190 } 3191 tbl[0].extra1 = net; 3192 3193 net->ipv4.route_hdr = 3194 register_net_sysctl_table(net, ipv4_route_path, tbl); 3195 if (net->ipv4.route_hdr == NULL) 3196 goto err_reg; 3197 return 0; 3198 3199 err_reg: 3200 if (tbl != ipv4_route_flush_table) 3201 kfree(tbl); 3202 err_dup: 3203 return -ENOMEM; 3204 } 3205 3206 static __net_exit void sysctl_route_net_exit(struct net *net) 3207 { 3208 struct ctl_table *tbl; 3209 3210 tbl = net->ipv4.route_hdr->ctl_table_arg; 3211 unregister_net_sysctl_table(net->ipv4.route_hdr); 3212 BUG_ON(tbl == ipv4_route_flush_table); 3213 kfree(tbl); 3214 } 3215 3216 static __net_initdata struct pernet_operations sysctl_route_ops = { 3217 .init = sysctl_route_net_init, 3218 .exit = sysctl_route_net_exit, 3219 }; 3220 #endif 3221 3222 static __net_init int rt_genid_init(struct net *net) 3223 { 3224 get_random_bytes(&net->ipv4.rt_genid, 3225 sizeof(net->ipv4.rt_genid)); 3226 get_random_bytes(&net->ipv4.dev_addr_genid, 3227 sizeof(net->ipv4.dev_addr_genid)); 3228 return 0; 3229 } 3230 3231 static __net_initdata struct pernet_operations rt_genid_ops = { 3232 .init = rt_genid_init, 3233 }; 3234 3235 3236 #ifdef CONFIG_IP_ROUTE_CLASSID 3237 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3238 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3239 3240 static __initdata unsigned long rhash_entries; 3241 static int __init set_rhash_entries(char *str) 3242 { 3243 if (!str) 3244 return 0; 3245 rhash_entries = simple_strtoul(str, &str, 0); 3246 return 1; 3247 } 3248 __setup("rhash_entries=", set_rhash_entries); 3249 3250 int __init ip_rt_init(void) 3251 { 3252 int rc = 0; 3253 3254 #ifdef CONFIG_IP_ROUTE_CLASSID 3255 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3256 if (!ip_rt_acct) 3257 panic("IP: failed to allocate ip_rt_acct\n"); 3258 #endif 3259 3260 ipv4_dst_ops.kmem_cachep = 3261 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3262 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3263 3264 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3265 3266 if (dst_entries_init(&ipv4_dst_ops) < 0) 3267 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3268 3269 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3270 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3271 3272 rt_hash_table = (struct rt_hash_bucket *) 3273 alloc_large_system_hash("IP route cache", 3274 sizeof(struct rt_hash_bucket), 3275 rhash_entries, 3276 (totalram_pages >= 128 * 1024) ? 3277 15 : 17, 3278 0, 3279 &rt_hash_log, 3280 &rt_hash_mask, 3281 rhash_entries ? 0 : 512 * 1024); 3282 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); 3283 rt_hash_lock_init(); 3284 3285 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); 3286 ip_rt_max_size = (rt_hash_mask + 1) * 16; 3287 3288 devinet_init(); 3289 ip_fib_init(); 3290 3291 if (ip_rt_proc_init()) 3292 printk(KERN_ERR "Unable to create route proc files\n"); 3293 #ifdef CONFIG_XFRM 3294 xfrm_init(); 3295 xfrm4_init(ip_rt_max_size); 3296 #endif 3297 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL); 3298 3299 #ifdef CONFIG_SYSCTL 3300 register_pernet_subsys(&sysctl_route_ops); 3301 #endif 3302 register_pernet_subsys(&rt_genid_ops); 3303 return rc; 3304 } 3305 3306 #ifdef CONFIG_SYSCTL 3307 /* 3308 * We really need to sanitize the damn ipv4 init order, then all 3309 * this nonsense will go away. 3310 */ 3311 void __init ip_static_sysctl_init(void) 3312 { 3313 register_sysctl_paths(ipv4_path, ipv4_skeleton); 3314 } 3315 #endif 3316