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 bool peer_pmtu_expired(struct inet_peer *peer) 1320 { 1321 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); 1322 1323 return orig && 1324 time_after_eq(jiffies, orig) && 1325 cmpxchg(&peer->pmtu_expires, orig, 0) == orig; 1326 } 1327 1328 static bool peer_pmtu_cleaned(struct inet_peer *peer) 1329 { 1330 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); 1331 1332 return orig && 1333 cmpxchg(&peer->pmtu_expires, orig, 0) == orig; 1334 } 1335 1336 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 1337 { 1338 struct rtable *rt = (struct rtable *)dst; 1339 struct dst_entry *ret = dst; 1340 1341 if (rt) { 1342 if (dst->obsolete > 0) { 1343 ip_rt_put(rt); 1344 ret = NULL; 1345 } else if (rt->rt_flags & RTCF_REDIRECTED) { 1346 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1347 rt->rt_oif, 1348 rt_genid(dev_net(dst->dev))); 1349 rt_del(hash, rt); 1350 ret = NULL; 1351 } else if (rt->peer && peer_pmtu_expired(rt->peer)) { 1352 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig); 1353 } 1354 } 1355 return ret; 1356 } 1357 1358 /* 1359 * Algorithm: 1360 * 1. The first ip_rt_redirect_number redirects are sent 1361 * with exponential backoff, then we stop sending them at all, 1362 * assuming that the host ignores our redirects. 1363 * 2. If we did not see packets requiring redirects 1364 * during ip_rt_redirect_silence, we assume that the host 1365 * forgot redirected route and start to send redirects again. 1366 * 1367 * This algorithm is much cheaper and more intelligent than dumb load limiting 1368 * in icmp.c. 1369 * 1370 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 1371 * and "frag. need" (breaks PMTU discovery) in icmp.c. 1372 */ 1373 1374 void ip_rt_send_redirect(struct sk_buff *skb) 1375 { 1376 struct rtable *rt = skb_rtable(skb); 1377 struct in_device *in_dev; 1378 struct inet_peer *peer; 1379 int log_martians; 1380 1381 rcu_read_lock(); 1382 in_dev = __in_dev_get_rcu(rt->dst.dev); 1383 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 1384 rcu_read_unlock(); 1385 return; 1386 } 1387 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 1388 rcu_read_unlock(); 1389 1390 if (!rt->peer) 1391 rt_bind_peer(rt, rt->rt_dst, 1); 1392 peer = rt->peer; 1393 if (!peer) { 1394 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1395 return; 1396 } 1397 1398 /* No redirected packets during ip_rt_redirect_silence; 1399 * reset the algorithm. 1400 */ 1401 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 1402 peer->rate_tokens = 0; 1403 1404 /* Too many ignored redirects; do not send anything 1405 * set dst.rate_last to the last seen redirected packet. 1406 */ 1407 if (peer->rate_tokens >= ip_rt_redirect_number) { 1408 peer->rate_last = jiffies; 1409 return; 1410 } 1411 1412 /* Check for load limit; set rate_last to the latest sent 1413 * redirect. 1414 */ 1415 if (peer->rate_tokens == 0 || 1416 time_after(jiffies, 1417 (peer->rate_last + 1418 (ip_rt_redirect_load << peer->rate_tokens)))) { 1419 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1420 peer->rate_last = jiffies; 1421 ++peer->rate_tokens; 1422 #ifdef CONFIG_IP_ROUTE_VERBOSE 1423 if (log_martians && 1424 peer->rate_tokens == ip_rt_redirect_number && 1425 net_ratelimit()) 1426 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", 1427 &ip_hdr(skb)->saddr, rt->rt_iif, 1428 &rt->rt_dst, &rt->rt_gateway); 1429 #endif 1430 } 1431 } 1432 1433 static int ip_error(struct sk_buff *skb) 1434 { 1435 struct rtable *rt = skb_rtable(skb); 1436 struct inet_peer *peer; 1437 unsigned long now; 1438 bool send; 1439 int code; 1440 1441 switch (rt->dst.error) { 1442 case EINVAL: 1443 default: 1444 goto out; 1445 case EHOSTUNREACH: 1446 code = ICMP_HOST_UNREACH; 1447 break; 1448 case ENETUNREACH: 1449 code = ICMP_NET_UNREACH; 1450 IP_INC_STATS_BH(dev_net(rt->dst.dev), 1451 IPSTATS_MIB_INNOROUTES); 1452 break; 1453 case EACCES: 1454 code = ICMP_PKT_FILTERED; 1455 break; 1456 } 1457 1458 if (!rt->peer) 1459 rt_bind_peer(rt, rt->rt_dst, 1); 1460 peer = rt->peer; 1461 1462 send = true; 1463 if (peer) { 1464 now = jiffies; 1465 peer->rate_tokens += now - peer->rate_last; 1466 if (peer->rate_tokens > ip_rt_error_burst) 1467 peer->rate_tokens = ip_rt_error_burst; 1468 peer->rate_last = now; 1469 if (peer->rate_tokens >= ip_rt_error_cost) 1470 peer->rate_tokens -= ip_rt_error_cost; 1471 else 1472 send = false; 1473 } 1474 if (send) 1475 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1476 1477 out: kfree_skb(skb); 1478 return 0; 1479 } 1480 1481 /* 1482 * The last two values are not from the RFC but 1483 * are needed for AMPRnet AX.25 paths. 1484 */ 1485 1486 static const unsigned short mtu_plateau[] = 1487 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 }; 1488 1489 static inline unsigned short guess_mtu(unsigned short old_mtu) 1490 { 1491 int i; 1492 1493 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++) 1494 if (old_mtu > mtu_plateau[i]) 1495 return mtu_plateau[i]; 1496 return 68; 1497 } 1498 1499 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, 1500 unsigned short new_mtu, 1501 struct net_device *dev) 1502 { 1503 unsigned short old_mtu = ntohs(iph->tot_len); 1504 unsigned short est_mtu = 0; 1505 struct inet_peer *peer; 1506 1507 peer = inet_getpeer_v4(iph->daddr, 1); 1508 if (peer) { 1509 unsigned short mtu = new_mtu; 1510 1511 if (new_mtu < 68 || new_mtu >= old_mtu) { 1512 /* BSD 4.2 derived systems incorrectly adjust 1513 * tot_len by the IP header length, and report 1514 * a zero MTU in the ICMP message. 1515 */ 1516 if (mtu == 0 && 1517 old_mtu >= 68 + (iph->ihl << 2)) 1518 old_mtu -= iph->ihl << 2; 1519 mtu = guess_mtu(old_mtu); 1520 } 1521 1522 if (mtu < ip_rt_min_pmtu) 1523 mtu = ip_rt_min_pmtu; 1524 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { 1525 unsigned long pmtu_expires; 1526 1527 pmtu_expires = jiffies + ip_rt_mtu_expires; 1528 if (!pmtu_expires) 1529 pmtu_expires = 1UL; 1530 1531 est_mtu = mtu; 1532 peer->pmtu_learned = mtu; 1533 peer->pmtu_expires = pmtu_expires; 1534 } 1535 1536 inet_putpeer(peer); 1537 1538 atomic_inc(&__rt_peer_genid); 1539 } 1540 return est_mtu ? : new_mtu; 1541 } 1542 1543 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) 1544 { 1545 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires); 1546 1547 if (!expires) 1548 return; 1549 if (time_before(jiffies, expires)) { 1550 u32 orig_dst_mtu = dst_mtu(dst); 1551 if (peer->pmtu_learned < orig_dst_mtu) { 1552 if (!peer->pmtu_orig) 1553 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU); 1554 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned); 1555 } 1556 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires) 1557 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig); 1558 } 1559 1560 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 1561 { 1562 struct rtable *rt = (struct rtable *) dst; 1563 struct inet_peer *peer; 1564 1565 dst_confirm(dst); 1566 1567 if (!rt->peer) 1568 rt_bind_peer(rt, rt->rt_dst, 1); 1569 peer = rt->peer; 1570 if (peer) { 1571 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires); 1572 1573 if (mtu < ip_rt_min_pmtu) 1574 mtu = ip_rt_min_pmtu; 1575 if (!pmtu_expires || mtu < peer->pmtu_learned) { 1576 1577 pmtu_expires = jiffies + ip_rt_mtu_expires; 1578 if (!pmtu_expires) 1579 pmtu_expires = 1UL; 1580 1581 peer->pmtu_learned = mtu; 1582 peer->pmtu_expires = pmtu_expires; 1583 1584 atomic_inc(&__rt_peer_genid); 1585 rt->rt_peer_genid = rt_peer_genid(); 1586 } 1587 check_peer_pmtu(dst, peer); 1588 } 1589 } 1590 1591 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) 1592 { 1593 struct rtable *rt = (struct rtable *) dst; 1594 __be32 orig_gw = rt->rt_gateway; 1595 1596 dst_confirm(&rt->dst); 1597 1598 neigh_release(rt->dst.neighbour); 1599 rt->dst.neighbour = NULL; 1600 1601 rt->rt_gateway = peer->redirect_learned.a4; 1602 if (arp_bind_neighbour(&rt->dst) || 1603 !(rt->dst.neighbour->nud_state & NUD_VALID)) { 1604 if (rt->dst.neighbour) 1605 neigh_event_send(rt->dst.neighbour, NULL); 1606 rt->rt_gateway = orig_gw; 1607 return -EAGAIN; 1608 } else { 1609 rt->rt_flags |= RTCF_REDIRECTED; 1610 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, 1611 rt->dst.neighbour); 1612 } 1613 return 0; 1614 } 1615 1616 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1617 { 1618 struct rtable *rt = (struct rtable *) dst; 1619 1620 if (rt_is_expired(rt)) 1621 return NULL; 1622 if (rt->rt_peer_genid != rt_peer_genid()) { 1623 struct inet_peer *peer; 1624 1625 if (!rt->peer) 1626 rt_bind_peer(rt, rt->rt_dst, 0); 1627 1628 peer = rt->peer; 1629 if (peer) { 1630 check_peer_pmtu(dst, peer); 1631 1632 if (peer->redirect_learned.a4 && 1633 peer->redirect_learned.a4 != rt->rt_gateway) { 1634 if (check_peer_redir(dst, peer)) 1635 return NULL; 1636 } 1637 } 1638 1639 rt->rt_peer_genid = rt_peer_genid(); 1640 } 1641 return dst; 1642 } 1643 1644 static void ipv4_dst_destroy(struct dst_entry *dst) 1645 { 1646 struct rtable *rt = (struct rtable *) dst; 1647 struct inet_peer *peer = rt->peer; 1648 1649 if (rt->fi) { 1650 fib_info_put(rt->fi); 1651 rt->fi = NULL; 1652 } 1653 if (peer) { 1654 rt->peer = NULL; 1655 inet_putpeer(peer); 1656 } 1657 } 1658 1659 1660 static void ipv4_link_failure(struct sk_buff *skb) 1661 { 1662 struct rtable *rt; 1663 1664 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1665 1666 rt = skb_rtable(skb); 1667 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer)) 1668 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); 1669 } 1670 1671 static int ip_rt_bug(struct sk_buff *skb) 1672 { 1673 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n", 1674 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1675 skb->dev ? skb->dev->name : "?"); 1676 kfree_skb(skb); 1677 WARN_ON(1); 1678 return 0; 1679 } 1680 1681 /* 1682 We do not cache source address of outgoing interface, 1683 because it is used only by IP RR, TS and SRR options, 1684 so that it out of fast path. 1685 1686 BTW remember: "addr" is allowed to be not aligned 1687 in IP options! 1688 */ 1689 1690 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1691 { 1692 __be32 src; 1693 1694 if (rt_is_output_route(rt)) 1695 src = ip_hdr(skb)->saddr; 1696 else { 1697 struct fib_result res; 1698 struct flowi4 fl4; 1699 struct iphdr *iph; 1700 1701 iph = ip_hdr(skb); 1702 1703 memset(&fl4, 0, sizeof(fl4)); 1704 fl4.daddr = iph->daddr; 1705 fl4.saddr = iph->saddr; 1706 fl4.flowi4_tos = iph->tos; 1707 fl4.flowi4_oif = rt->dst.dev->ifindex; 1708 fl4.flowi4_iif = skb->dev->ifindex; 1709 fl4.flowi4_mark = skb->mark; 1710 1711 rcu_read_lock(); 1712 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1713 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1714 else 1715 src = inet_select_addr(rt->dst.dev, rt->rt_gateway, 1716 RT_SCOPE_UNIVERSE); 1717 rcu_read_unlock(); 1718 } 1719 memcpy(addr, &src, 4); 1720 } 1721 1722 #ifdef CONFIG_IP_ROUTE_CLASSID 1723 static void set_class_tag(struct rtable *rt, u32 tag) 1724 { 1725 if (!(rt->dst.tclassid & 0xFFFF)) 1726 rt->dst.tclassid |= tag & 0xFFFF; 1727 if (!(rt->dst.tclassid & 0xFFFF0000)) 1728 rt->dst.tclassid |= tag & 0xFFFF0000; 1729 } 1730 #endif 1731 1732 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1733 { 1734 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1735 1736 if (advmss == 0) { 1737 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1738 ip_rt_min_advmss); 1739 if (advmss > 65535 - 40) 1740 advmss = 65535 - 40; 1741 } 1742 return advmss; 1743 } 1744 1745 static unsigned int ipv4_default_mtu(const struct dst_entry *dst) 1746 { 1747 unsigned int mtu = dst->dev->mtu; 1748 1749 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1750 const struct rtable *rt = (const struct rtable *) dst; 1751 1752 if (rt->rt_gateway != rt->rt_dst && mtu > 576) 1753 mtu = 576; 1754 } 1755 1756 if (mtu > IP_MAX_MTU) 1757 mtu = IP_MAX_MTU; 1758 1759 return mtu; 1760 } 1761 1762 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, 1763 struct fib_info *fi) 1764 { 1765 struct inet_peer *peer; 1766 int create = 0; 1767 1768 /* If a peer entry exists for this destination, we must hook 1769 * it up in order to get at cached metrics. 1770 */ 1771 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS)) 1772 create = 1; 1773 1774 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create); 1775 if (peer) { 1776 rt->rt_peer_genid = rt_peer_genid(); 1777 if (inet_metrics_new(peer)) 1778 memcpy(peer->metrics, fi->fib_metrics, 1779 sizeof(u32) * RTAX_MAX); 1780 dst_init_metrics(&rt->dst, peer->metrics, false); 1781 1782 check_peer_pmtu(&rt->dst, peer); 1783 if (peer->redirect_learned.a4 && 1784 peer->redirect_learned.a4 != rt->rt_gateway) { 1785 rt->rt_gateway = peer->redirect_learned.a4; 1786 rt->rt_flags |= RTCF_REDIRECTED; 1787 } 1788 } else { 1789 if (fi->fib_metrics != (u32 *) dst_default_metrics) { 1790 rt->fi = fi; 1791 atomic_inc(&fi->fib_clntref); 1792 } 1793 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1794 } 1795 } 1796 1797 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4, 1798 const struct fib_result *res, 1799 struct fib_info *fi, u16 type, u32 itag) 1800 { 1801 struct dst_entry *dst = &rt->dst; 1802 1803 if (fi) { 1804 if (FIB_RES_GW(*res) && 1805 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 1806 rt->rt_gateway = FIB_RES_GW(*res); 1807 rt_init_metrics(rt, fl4, fi); 1808 #ifdef CONFIG_IP_ROUTE_CLASSID 1809 dst->tclassid = FIB_RES_NH(*res).nh_tclassid; 1810 #endif 1811 } 1812 1813 if (dst_mtu(dst) > IP_MAX_MTU) 1814 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU); 1815 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40) 1816 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40); 1817 1818 #ifdef CONFIG_IP_ROUTE_CLASSID 1819 #ifdef CONFIG_IP_MULTIPLE_TABLES 1820 set_class_tag(rt, fib_rules_tclass(res)); 1821 #endif 1822 set_class_tag(rt, itag); 1823 #endif 1824 } 1825 1826 static struct rtable *rt_dst_alloc(struct net_device *dev, 1827 bool nopolicy, bool noxfrm) 1828 { 1829 return dst_alloc(&ipv4_dst_ops, dev, 1, -1, 1830 DST_HOST | 1831 (nopolicy ? DST_NOPOLICY : 0) | 1832 (noxfrm ? DST_NOXFRM : 0)); 1833 } 1834 1835 /* called in rcu_read_lock() section */ 1836 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1837 u8 tos, struct net_device *dev, int our) 1838 { 1839 unsigned int hash; 1840 struct rtable *rth; 1841 __be32 spec_dst; 1842 struct in_device *in_dev = __in_dev_get_rcu(dev); 1843 u32 itag = 0; 1844 int err; 1845 1846 /* Primary sanity checks. */ 1847 1848 if (in_dev == NULL) 1849 return -EINVAL; 1850 1851 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1852 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP)) 1853 goto e_inval; 1854 1855 if (ipv4_is_zeronet(saddr)) { 1856 if (!ipv4_is_local_multicast(daddr)) 1857 goto e_inval; 1858 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 1859 } else { 1860 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 1861 &itag); 1862 if (err < 0) 1863 goto e_err; 1864 } 1865 rth = rt_dst_alloc(init_net.loopback_dev, 1866 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 1867 if (!rth) 1868 goto e_nobufs; 1869 1870 #ifdef CONFIG_IP_ROUTE_CLASSID 1871 rth->dst.tclassid = itag; 1872 #endif 1873 rth->dst.output = ip_rt_bug; 1874 1875 rth->rt_key_dst = daddr; 1876 rth->rt_key_src = saddr; 1877 rth->rt_genid = rt_genid(dev_net(dev)); 1878 rth->rt_flags = RTCF_MULTICAST; 1879 rth->rt_type = RTN_MULTICAST; 1880 rth->rt_key_tos = tos; 1881 rth->rt_dst = daddr; 1882 rth->rt_src = saddr; 1883 rth->rt_route_iif = dev->ifindex; 1884 rth->rt_iif = dev->ifindex; 1885 rth->rt_oif = 0; 1886 rth->rt_mark = skb->mark; 1887 rth->rt_gateway = daddr; 1888 rth->rt_spec_dst= spec_dst; 1889 rth->rt_peer_genid = 0; 1890 rth->peer = NULL; 1891 rth->fi = NULL; 1892 if (our) { 1893 rth->dst.input= ip_local_deliver; 1894 rth->rt_flags |= RTCF_LOCAL; 1895 } 1896 1897 #ifdef CONFIG_IP_MROUTE 1898 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1899 rth->dst.input = ip_mr_input; 1900 #endif 1901 RT_CACHE_STAT_INC(in_slow_mc); 1902 1903 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); 1904 rth = rt_intern_hash(hash, rth, skb, dev->ifindex); 1905 return IS_ERR(rth) ? PTR_ERR(rth) : 0; 1906 1907 e_nobufs: 1908 return -ENOBUFS; 1909 e_inval: 1910 return -EINVAL; 1911 e_err: 1912 return err; 1913 } 1914 1915 1916 static void ip_handle_martian_source(struct net_device *dev, 1917 struct in_device *in_dev, 1918 struct sk_buff *skb, 1919 __be32 daddr, 1920 __be32 saddr) 1921 { 1922 RT_CACHE_STAT_INC(in_martian_src); 1923 #ifdef CONFIG_IP_ROUTE_VERBOSE 1924 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1925 /* 1926 * RFC1812 recommendation, if source is martian, 1927 * the only hint is MAC header. 1928 */ 1929 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n", 1930 &daddr, &saddr, dev->name); 1931 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1932 int i; 1933 const unsigned char *p = skb_mac_header(skb); 1934 printk(KERN_WARNING "ll header: "); 1935 for (i = 0; i < dev->hard_header_len; i++, p++) { 1936 printk("%02x", *p); 1937 if (i < (dev->hard_header_len - 1)) 1938 printk(":"); 1939 } 1940 printk("\n"); 1941 } 1942 } 1943 #endif 1944 } 1945 1946 /* called in rcu_read_lock() section */ 1947 static int __mkroute_input(struct sk_buff *skb, 1948 const struct fib_result *res, 1949 struct in_device *in_dev, 1950 __be32 daddr, __be32 saddr, u32 tos, 1951 struct rtable **result) 1952 { 1953 struct rtable *rth; 1954 int err; 1955 struct in_device *out_dev; 1956 unsigned int flags = 0; 1957 __be32 spec_dst; 1958 u32 itag; 1959 1960 /* get a working reference to the output device */ 1961 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1962 if (out_dev == NULL) { 1963 if (net_ratelimit()) 1964 printk(KERN_CRIT "Bug in ip_route_input" \ 1965 "_slow(). Please, report\n"); 1966 return -EINVAL; 1967 } 1968 1969 1970 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1971 in_dev->dev, &spec_dst, &itag); 1972 if (err < 0) { 1973 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1974 saddr); 1975 1976 goto cleanup; 1977 } 1978 1979 if (err) 1980 flags |= RTCF_DIRECTSRC; 1981 1982 if (out_dev == in_dev && err && 1983 (IN_DEV_SHARED_MEDIA(out_dev) || 1984 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1985 flags |= RTCF_DOREDIRECT; 1986 1987 if (skb->protocol != htons(ETH_P_IP)) { 1988 /* Not IP (i.e. ARP). Do not create route, if it is 1989 * invalid for proxy arp. DNAT routes are always valid. 1990 * 1991 * Proxy arp feature have been extended to allow, ARP 1992 * replies back to the same interface, to support 1993 * Private VLAN switch technologies. See arp.c. 1994 */ 1995 if (out_dev == in_dev && 1996 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 1997 err = -EINVAL; 1998 goto cleanup; 1999 } 2000 } 2001 2002 rth = rt_dst_alloc(out_dev->dev, 2003 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2004 IN_DEV_CONF_GET(out_dev, NOXFRM)); 2005 if (!rth) { 2006 err = -ENOBUFS; 2007 goto cleanup; 2008 } 2009 2010 rth->rt_key_dst = daddr; 2011 rth->rt_key_src = saddr; 2012 rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); 2013 rth->rt_flags = flags; 2014 rth->rt_type = res->type; 2015 rth->rt_key_tos = tos; 2016 rth->rt_dst = daddr; 2017 rth->rt_src = saddr; 2018 rth->rt_route_iif = in_dev->dev->ifindex; 2019 rth->rt_iif = in_dev->dev->ifindex; 2020 rth->rt_oif = 0; 2021 rth->rt_mark = skb->mark; 2022 rth->rt_gateway = daddr; 2023 rth->rt_spec_dst= spec_dst; 2024 rth->rt_peer_genid = 0; 2025 rth->peer = NULL; 2026 rth->fi = NULL; 2027 2028 rth->dst.input = ip_forward; 2029 rth->dst.output = ip_output; 2030 2031 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag); 2032 2033 *result = rth; 2034 err = 0; 2035 cleanup: 2036 return err; 2037 } 2038 2039 static int ip_mkroute_input(struct sk_buff *skb, 2040 struct fib_result *res, 2041 const struct flowi4 *fl4, 2042 struct in_device *in_dev, 2043 __be32 daddr, __be32 saddr, u32 tos) 2044 { 2045 struct rtable* rth = NULL; 2046 int err; 2047 unsigned hash; 2048 2049 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2050 if (res->fi && res->fi->fib_nhs > 1) 2051 fib_select_multipath(res); 2052 #endif 2053 2054 /* create a routing cache entry */ 2055 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); 2056 if (err) 2057 return err; 2058 2059 /* put it into the cache */ 2060 hash = rt_hash(daddr, saddr, fl4->flowi4_iif, 2061 rt_genid(dev_net(rth->dst.dev))); 2062 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif); 2063 if (IS_ERR(rth)) 2064 return PTR_ERR(rth); 2065 return 0; 2066 } 2067 2068 /* 2069 * NOTE. We drop all the packets that has local source 2070 * addresses, because every properly looped back packet 2071 * must have correct destination already attached by output routine. 2072 * 2073 * Such approach solves two big problems: 2074 * 1. Not simplex devices are handled properly. 2075 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2076 * called with rcu_read_lock() 2077 */ 2078 2079 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2080 u8 tos, struct net_device *dev) 2081 { 2082 struct fib_result res; 2083 struct in_device *in_dev = __in_dev_get_rcu(dev); 2084 struct flowi4 fl4; 2085 unsigned flags = 0; 2086 u32 itag = 0; 2087 struct rtable * rth; 2088 unsigned hash; 2089 __be32 spec_dst; 2090 int err = -EINVAL; 2091 struct net * net = dev_net(dev); 2092 2093 /* IP on this device is disabled. */ 2094 2095 if (!in_dev) 2096 goto out; 2097 2098 /* Check for the most weird martians, which can be not detected 2099 by fib_lookup. 2100 */ 2101 2102 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 2103 ipv4_is_loopback(saddr)) 2104 goto martian_source; 2105 2106 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2107 goto brd_input; 2108 2109 /* Accept zero addresses only to limited broadcast; 2110 * I even do not know to fix it or not. Waiting for complains :-) 2111 */ 2112 if (ipv4_is_zeronet(saddr)) 2113 goto martian_source; 2114 2115 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr)) 2116 goto martian_destination; 2117 2118 /* 2119 * Now we are ready to route packet. 2120 */ 2121 fl4.flowi4_oif = 0; 2122 fl4.flowi4_iif = dev->ifindex; 2123 fl4.flowi4_mark = skb->mark; 2124 fl4.flowi4_tos = tos; 2125 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2126 fl4.daddr = daddr; 2127 fl4.saddr = saddr; 2128 err = fib_lookup(net, &fl4, &res); 2129 if (err != 0) { 2130 if (!IN_DEV_FORWARD(in_dev)) 2131 goto e_hostunreach; 2132 goto no_route; 2133 } 2134 2135 RT_CACHE_STAT_INC(in_slow_tot); 2136 2137 if (res.type == RTN_BROADCAST) 2138 goto brd_input; 2139 2140 if (res.type == RTN_LOCAL) { 2141 err = fib_validate_source(skb, saddr, daddr, tos, 2142 net->loopback_dev->ifindex, 2143 dev, &spec_dst, &itag); 2144 if (err < 0) 2145 goto martian_source_keep_err; 2146 if (err) 2147 flags |= RTCF_DIRECTSRC; 2148 spec_dst = daddr; 2149 goto local_input; 2150 } 2151 2152 if (!IN_DEV_FORWARD(in_dev)) 2153 goto e_hostunreach; 2154 if (res.type != RTN_UNICAST) 2155 goto martian_destination; 2156 2157 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 2158 out: return err; 2159 2160 brd_input: 2161 if (skb->protocol != htons(ETH_P_IP)) 2162 goto e_inval; 2163 2164 if (ipv4_is_zeronet(saddr)) 2165 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 2166 else { 2167 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 2168 &itag); 2169 if (err < 0) 2170 goto martian_source_keep_err; 2171 if (err) 2172 flags |= RTCF_DIRECTSRC; 2173 } 2174 flags |= RTCF_BROADCAST; 2175 res.type = RTN_BROADCAST; 2176 RT_CACHE_STAT_INC(in_brd); 2177 2178 local_input: 2179 rth = rt_dst_alloc(net->loopback_dev, 2180 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 2181 if (!rth) 2182 goto e_nobufs; 2183 2184 rth->dst.input= ip_local_deliver; 2185 rth->dst.output= ip_rt_bug; 2186 #ifdef CONFIG_IP_ROUTE_CLASSID 2187 rth->dst.tclassid = itag; 2188 #endif 2189 2190 rth->rt_key_dst = daddr; 2191 rth->rt_key_src = saddr; 2192 rth->rt_genid = rt_genid(net); 2193 rth->rt_flags = flags|RTCF_LOCAL; 2194 rth->rt_type = res.type; 2195 rth->rt_key_tos = tos; 2196 rth->rt_dst = daddr; 2197 rth->rt_src = saddr; 2198 #ifdef CONFIG_IP_ROUTE_CLASSID 2199 rth->dst.tclassid = itag; 2200 #endif 2201 rth->rt_route_iif = dev->ifindex; 2202 rth->rt_iif = dev->ifindex; 2203 rth->rt_oif = 0; 2204 rth->rt_mark = skb->mark; 2205 rth->rt_gateway = daddr; 2206 rth->rt_spec_dst= spec_dst; 2207 rth->rt_peer_genid = 0; 2208 rth->peer = NULL; 2209 rth->fi = NULL; 2210 if (res.type == RTN_UNREACHABLE) { 2211 rth->dst.input= ip_error; 2212 rth->dst.error= -err; 2213 rth->rt_flags &= ~RTCF_LOCAL; 2214 } 2215 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net)); 2216 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif); 2217 err = 0; 2218 if (IS_ERR(rth)) 2219 err = PTR_ERR(rth); 2220 goto out; 2221 2222 no_route: 2223 RT_CACHE_STAT_INC(in_no_route); 2224 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 2225 res.type = RTN_UNREACHABLE; 2226 if (err == -ESRCH) 2227 err = -ENETUNREACH; 2228 goto local_input; 2229 2230 /* 2231 * Do not cache martian addresses: they should be logged (RFC1812) 2232 */ 2233 martian_destination: 2234 RT_CACHE_STAT_INC(in_martian_dst); 2235 #ifdef CONFIG_IP_ROUTE_VERBOSE 2236 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 2237 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n", 2238 &daddr, &saddr, dev->name); 2239 #endif 2240 2241 e_hostunreach: 2242 err = -EHOSTUNREACH; 2243 goto out; 2244 2245 e_inval: 2246 err = -EINVAL; 2247 goto out; 2248 2249 e_nobufs: 2250 err = -ENOBUFS; 2251 goto out; 2252 2253 martian_source: 2254 err = -EINVAL; 2255 martian_source_keep_err: 2256 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2257 goto out; 2258 } 2259 2260 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2261 u8 tos, struct net_device *dev, bool noref) 2262 { 2263 struct rtable * rth; 2264 unsigned hash; 2265 int iif = dev->ifindex; 2266 struct net *net; 2267 int res; 2268 2269 net = dev_net(dev); 2270 2271 rcu_read_lock(); 2272 2273 if (!rt_caching(net)) 2274 goto skip_cache; 2275 2276 tos &= IPTOS_RT_MASK; 2277 hash = rt_hash(daddr, saddr, iif, rt_genid(net)); 2278 2279 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 2280 rth = rcu_dereference(rth->dst.rt_next)) { 2281 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) | 2282 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) | 2283 (rth->rt_iif ^ iif) | 2284 rth->rt_oif | 2285 (rth->rt_key_tos ^ tos)) == 0 && 2286 rth->rt_mark == skb->mark && 2287 net_eq(dev_net(rth->dst.dev), net) && 2288 !rt_is_expired(rth)) { 2289 if (noref) { 2290 dst_use_noref(&rth->dst, jiffies); 2291 skb_dst_set_noref(skb, &rth->dst); 2292 } else { 2293 dst_use(&rth->dst, jiffies); 2294 skb_dst_set(skb, &rth->dst); 2295 } 2296 RT_CACHE_STAT_INC(in_hit); 2297 rcu_read_unlock(); 2298 return 0; 2299 } 2300 RT_CACHE_STAT_INC(in_hlist_search); 2301 } 2302 2303 skip_cache: 2304 /* Multicast recognition logic is moved from route cache to here. 2305 The problem was that too many Ethernet cards have broken/missing 2306 hardware multicast filters :-( As result the host on multicasting 2307 network acquires a lot of useless route cache entries, sort of 2308 SDR messages from all the world. Now we try to get rid of them. 2309 Really, provided software IP multicast filter is organized 2310 reasonably (at least, hashed), it does not result in a slowdown 2311 comparing with route cache reject entries. 2312 Note, that multicast routers are not affected, because 2313 route cache entry is created eventually. 2314 */ 2315 if (ipv4_is_multicast(daddr)) { 2316 struct in_device *in_dev = __in_dev_get_rcu(dev); 2317 2318 if (in_dev) { 2319 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 2320 ip_hdr(skb)->protocol); 2321 if (our 2322 #ifdef CONFIG_IP_MROUTE 2323 || 2324 (!ipv4_is_local_multicast(daddr) && 2325 IN_DEV_MFORWARD(in_dev)) 2326 #endif 2327 ) { 2328 int res = ip_route_input_mc(skb, daddr, saddr, 2329 tos, dev, our); 2330 rcu_read_unlock(); 2331 return res; 2332 } 2333 } 2334 rcu_read_unlock(); 2335 return -EINVAL; 2336 } 2337 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 2338 rcu_read_unlock(); 2339 return res; 2340 } 2341 EXPORT_SYMBOL(ip_route_input_common); 2342 2343 /* called with rcu_read_lock() */ 2344 static struct rtable *__mkroute_output(const struct fib_result *res, 2345 const struct flowi4 *fl4, 2346 __be32 orig_daddr, __be32 orig_saddr, 2347 int orig_oif, struct net_device *dev_out, 2348 unsigned int flags) 2349 { 2350 struct fib_info *fi = res->fi; 2351 u32 tos = RT_FL_TOS(fl4); 2352 struct in_device *in_dev; 2353 u16 type = res->type; 2354 struct rtable *rth; 2355 2356 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 2357 return ERR_PTR(-EINVAL); 2358 2359 if (ipv4_is_lbcast(fl4->daddr)) 2360 type = RTN_BROADCAST; 2361 else if (ipv4_is_multicast(fl4->daddr)) 2362 type = RTN_MULTICAST; 2363 else if (ipv4_is_zeronet(fl4->daddr)) 2364 return ERR_PTR(-EINVAL); 2365 2366 if (dev_out->flags & IFF_LOOPBACK) 2367 flags |= RTCF_LOCAL; 2368 2369 in_dev = __in_dev_get_rcu(dev_out); 2370 if (!in_dev) 2371 return ERR_PTR(-EINVAL); 2372 2373 if (type == RTN_BROADCAST) { 2374 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2375 fi = NULL; 2376 } else if (type == RTN_MULTICAST) { 2377 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2378 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2379 fl4->flowi4_proto)) 2380 flags &= ~RTCF_LOCAL; 2381 /* If multicast route do not exist use 2382 * default one, but do not gateway in this case. 2383 * Yes, it is hack. 2384 */ 2385 if (fi && res->prefixlen < 4) 2386 fi = NULL; 2387 } 2388 2389 rth = rt_dst_alloc(dev_out, 2390 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2391 IN_DEV_CONF_GET(in_dev, NOXFRM)); 2392 if (!rth) 2393 return ERR_PTR(-ENOBUFS); 2394 2395 rth->dst.output = ip_output; 2396 2397 rth->rt_key_dst = orig_daddr; 2398 rth->rt_key_src = orig_saddr; 2399 rth->rt_genid = rt_genid(dev_net(dev_out)); 2400 rth->rt_flags = flags; 2401 rth->rt_type = type; 2402 rth->rt_key_tos = tos; 2403 rth->rt_dst = fl4->daddr; 2404 rth->rt_src = fl4->saddr; 2405 rth->rt_route_iif = 0; 2406 rth->rt_iif = orig_oif ? : dev_out->ifindex; 2407 rth->rt_oif = orig_oif; 2408 rth->rt_mark = fl4->flowi4_mark; 2409 rth->rt_gateway = fl4->daddr; 2410 rth->rt_spec_dst= fl4->saddr; 2411 rth->rt_peer_genid = 0; 2412 rth->peer = NULL; 2413 rth->fi = NULL; 2414 2415 RT_CACHE_STAT_INC(out_slow_tot); 2416 2417 if (flags & RTCF_LOCAL) { 2418 rth->dst.input = ip_local_deliver; 2419 rth->rt_spec_dst = fl4->daddr; 2420 } 2421 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2422 rth->rt_spec_dst = fl4->saddr; 2423 if (flags & RTCF_LOCAL && 2424 !(dev_out->flags & IFF_LOOPBACK)) { 2425 rth->dst.output = ip_mc_output; 2426 RT_CACHE_STAT_INC(out_slow_mc); 2427 } 2428 #ifdef CONFIG_IP_MROUTE 2429 if (type == RTN_MULTICAST) { 2430 if (IN_DEV_MFORWARD(in_dev) && 2431 !ipv4_is_local_multicast(fl4->daddr)) { 2432 rth->dst.input = ip_mr_input; 2433 rth->dst.output = ip_mc_output; 2434 } 2435 } 2436 #endif 2437 } 2438 2439 rt_set_nexthop(rth, fl4, res, fi, type, 0); 2440 2441 return rth; 2442 } 2443 2444 /* 2445 * Major route resolver routine. 2446 * called with rcu_read_lock(); 2447 */ 2448 2449 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) 2450 { 2451 struct net_device *dev_out = NULL; 2452 u32 tos = RT_FL_TOS(fl4); 2453 unsigned int flags = 0; 2454 struct fib_result res; 2455 struct rtable *rth; 2456 __be32 orig_daddr; 2457 __be32 orig_saddr; 2458 int orig_oif; 2459 2460 res.fi = NULL; 2461 #ifdef CONFIG_IP_MULTIPLE_TABLES 2462 res.r = NULL; 2463 #endif 2464 2465 orig_daddr = fl4->daddr; 2466 orig_saddr = fl4->saddr; 2467 orig_oif = fl4->flowi4_oif; 2468 2469 fl4->flowi4_iif = net->loopback_dev->ifindex; 2470 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2471 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2472 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2473 2474 rcu_read_lock(); 2475 if (fl4->saddr) { 2476 rth = ERR_PTR(-EINVAL); 2477 if (ipv4_is_multicast(fl4->saddr) || 2478 ipv4_is_lbcast(fl4->saddr) || 2479 ipv4_is_zeronet(fl4->saddr)) 2480 goto out; 2481 2482 /* I removed check for oif == dev_out->oif here. 2483 It was wrong for two reasons: 2484 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2485 is assigned to multiple interfaces. 2486 2. Moreover, we are allowed to send packets with saddr 2487 of another iface. --ANK 2488 */ 2489 2490 if (fl4->flowi4_oif == 0 && 2491 (ipv4_is_multicast(fl4->daddr) || 2492 ipv4_is_lbcast(fl4->daddr))) { 2493 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2494 dev_out = __ip_dev_find(net, fl4->saddr, false); 2495 if (dev_out == NULL) 2496 goto out; 2497 2498 /* Special hack: user can direct multicasts 2499 and limited broadcast via necessary interface 2500 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2501 This hack is not just for fun, it allows 2502 vic,vat and friends to work. 2503 They bind socket to loopback, set ttl to zero 2504 and expect that it will work. 2505 From the viewpoint of routing cache they are broken, 2506 because we are not allowed to build multicast path 2507 with loopback source addr (look, routing cache 2508 cannot know, that ttl is zero, so that packet 2509 will not leave this host and route is valid). 2510 Luckily, this hack is good workaround. 2511 */ 2512 2513 fl4->flowi4_oif = dev_out->ifindex; 2514 goto make_route; 2515 } 2516 2517 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2518 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2519 if (!__ip_dev_find(net, fl4->saddr, false)) 2520 goto out; 2521 } 2522 } 2523 2524 2525 if (fl4->flowi4_oif) { 2526 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2527 rth = ERR_PTR(-ENODEV); 2528 if (dev_out == NULL) 2529 goto out; 2530 2531 /* RACE: Check return value of inet_select_addr instead. */ 2532 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2533 rth = ERR_PTR(-ENETUNREACH); 2534 goto out; 2535 } 2536 if (ipv4_is_local_multicast(fl4->daddr) || 2537 ipv4_is_lbcast(fl4->daddr)) { 2538 if (!fl4->saddr) 2539 fl4->saddr = inet_select_addr(dev_out, 0, 2540 RT_SCOPE_LINK); 2541 goto make_route; 2542 } 2543 if (fl4->saddr) { 2544 if (ipv4_is_multicast(fl4->daddr)) 2545 fl4->saddr = inet_select_addr(dev_out, 0, 2546 fl4->flowi4_scope); 2547 else if (!fl4->daddr) 2548 fl4->saddr = inet_select_addr(dev_out, 0, 2549 RT_SCOPE_HOST); 2550 } 2551 } 2552 2553 if (!fl4->daddr) { 2554 fl4->daddr = fl4->saddr; 2555 if (!fl4->daddr) 2556 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2557 dev_out = net->loopback_dev; 2558 fl4->flowi4_oif = net->loopback_dev->ifindex; 2559 res.type = RTN_LOCAL; 2560 flags |= RTCF_LOCAL; 2561 goto make_route; 2562 } 2563 2564 if (fib_lookup(net, fl4, &res)) { 2565 res.fi = NULL; 2566 if (fl4->flowi4_oif) { 2567 /* Apparently, routing tables are wrong. Assume, 2568 that the destination is on link. 2569 2570 WHY? DW. 2571 Because we are allowed to send to iface 2572 even if it has NO routes and NO assigned 2573 addresses. When oif is specified, routing 2574 tables are looked up with only one purpose: 2575 to catch if destination is gatewayed, rather than 2576 direct. Moreover, if MSG_DONTROUTE is set, 2577 we send packet, ignoring both routing tables 2578 and ifaddr state. --ANK 2579 2580 2581 We could make it even if oif is unknown, 2582 likely IPv6, but we do not. 2583 */ 2584 2585 if (fl4->saddr == 0) 2586 fl4->saddr = inet_select_addr(dev_out, 0, 2587 RT_SCOPE_LINK); 2588 res.type = RTN_UNICAST; 2589 goto make_route; 2590 } 2591 rth = ERR_PTR(-ENETUNREACH); 2592 goto out; 2593 } 2594 2595 if (res.type == RTN_LOCAL) { 2596 if (!fl4->saddr) { 2597 if (res.fi->fib_prefsrc) 2598 fl4->saddr = res.fi->fib_prefsrc; 2599 else 2600 fl4->saddr = fl4->daddr; 2601 } 2602 dev_out = net->loopback_dev; 2603 fl4->flowi4_oif = dev_out->ifindex; 2604 res.fi = NULL; 2605 flags |= RTCF_LOCAL; 2606 goto make_route; 2607 } 2608 2609 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2610 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2611 fib_select_multipath(&res); 2612 else 2613 #endif 2614 if (!res.prefixlen && 2615 res.table->tb_num_default > 1 && 2616 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2617 fib_select_default(&res); 2618 2619 if (!fl4->saddr) 2620 fl4->saddr = FIB_RES_PREFSRC(net, res); 2621 2622 dev_out = FIB_RES_DEV(res); 2623 fl4->flowi4_oif = dev_out->ifindex; 2624 2625 2626 make_route: 2627 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif, 2628 dev_out, flags); 2629 if (!IS_ERR(rth)) { 2630 unsigned int hash; 2631 2632 hash = rt_hash(orig_daddr, orig_saddr, orig_oif, 2633 rt_genid(dev_net(dev_out))); 2634 rth = rt_intern_hash(hash, rth, NULL, orig_oif); 2635 } 2636 2637 out: 2638 rcu_read_unlock(); 2639 return rth; 2640 } 2641 2642 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) 2643 { 2644 struct rtable *rth; 2645 unsigned int hash; 2646 2647 if (!rt_caching(net)) 2648 goto slow_output; 2649 2650 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net)); 2651 2652 rcu_read_lock_bh(); 2653 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; 2654 rth = rcu_dereference_bh(rth->dst.rt_next)) { 2655 if (rth->rt_key_dst == flp4->daddr && 2656 rth->rt_key_src == flp4->saddr && 2657 rt_is_output_route(rth) && 2658 rth->rt_oif == flp4->flowi4_oif && 2659 rth->rt_mark == flp4->flowi4_mark && 2660 !((rth->rt_key_tos ^ flp4->flowi4_tos) & 2661 (IPTOS_RT_MASK | RTO_ONLINK)) && 2662 net_eq(dev_net(rth->dst.dev), net) && 2663 !rt_is_expired(rth)) { 2664 dst_use(&rth->dst, jiffies); 2665 RT_CACHE_STAT_INC(out_hit); 2666 rcu_read_unlock_bh(); 2667 if (!flp4->saddr) 2668 flp4->saddr = rth->rt_src; 2669 if (!flp4->daddr) 2670 flp4->daddr = rth->rt_dst; 2671 return rth; 2672 } 2673 RT_CACHE_STAT_INC(out_hlist_search); 2674 } 2675 rcu_read_unlock_bh(); 2676 2677 slow_output: 2678 return ip_route_output_slow(net, flp4); 2679 } 2680 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2681 2682 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2683 { 2684 return NULL; 2685 } 2686 2687 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst) 2688 { 2689 return 0; 2690 } 2691 2692 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) 2693 { 2694 } 2695 2696 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2697 unsigned long old) 2698 { 2699 return NULL; 2700 } 2701 2702 static struct dst_ops ipv4_dst_blackhole_ops = { 2703 .family = AF_INET, 2704 .protocol = cpu_to_be16(ETH_P_IP), 2705 .destroy = ipv4_dst_destroy, 2706 .check = ipv4_blackhole_dst_check, 2707 .default_mtu = ipv4_blackhole_default_mtu, 2708 .default_advmss = ipv4_default_advmss, 2709 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2710 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2711 }; 2712 2713 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2714 { 2715 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0); 2716 struct rtable *ort = (struct rtable *) dst_orig; 2717 2718 if (rt) { 2719 struct dst_entry *new = &rt->dst; 2720 2721 new->__use = 1; 2722 new->input = dst_discard; 2723 new->output = dst_discard; 2724 dst_copy_metrics(new, &ort->dst); 2725 2726 new->dev = ort->dst.dev; 2727 if (new->dev) 2728 dev_hold(new->dev); 2729 2730 rt->rt_key_dst = ort->rt_key_dst; 2731 rt->rt_key_src = ort->rt_key_src; 2732 rt->rt_key_tos = ort->rt_key_tos; 2733 rt->rt_route_iif = ort->rt_route_iif; 2734 rt->rt_iif = ort->rt_iif; 2735 rt->rt_oif = ort->rt_oif; 2736 rt->rt_mark = ort->rt_mark; 2737 2738 rt->rt_genid = rt_genid(net); 2739 rt->rt_flags = ort->rt_flags; 2740 rt->rt_type = ort->rt_type; 2741 rt->rt_dst = ort->rt_dst; 2742 rt->rt_src = ort->rt_src; 2743 rt->rt_gateway = ort->rt_gateway; 2744 rt->rt_spec_dst = ort->rt_spec_dst; 2745 rt->peer = ort->peer; 2746 if (rt->peer) 2747 atomic_inc(&rt->peer->refcnt); 2748 rt->fi = ort->fi; 2749 if (rt->fi) 2750 atomic_inc(&rt->fi->fib_clntref); 2751 2752 dst_free(new); 2753 } 2754 2755 dst_release(dst_orig); 2756 2757 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2758 } 2759 2760 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2761 struct sock *sk) 2762 { 2763 struct rtable *rt = __ip_route_output_key(net, flp4); 2764 2765 if (IS_ERR(rt)) 2766 return rt; 2767 2768 if (flp4->flowi4_proto) 2769 rt = (struct rtable *) xfrm_lookup(net, &rt->dst, 2770 flowi4_to_flowi(flp4), 2771 sk, 0); 2772 2773 return rt; 2774 } 2775 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2776 2777 static int rt_fill_info(struct net *net, 2778 struct sk_buff *skb, u32 pid, u32 seq, int event, 2779 int nowait, unsigned int flags) 2780 { 2781 struct rtable *rt = skb_rtable(skb); 2782 struct rtmsg *r; 2783 struct nlmsghdr *nlh; 2784 long expires = 0; 2785 const struct inet_peer *peer = rt->peer; 2786 u32 id = 0, ts = 0, tsage = 0, error; 2787 2788 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); 2789 if (nlh == NULL) 2790 return -EMSGSIZE; 2791 2792 r = nlmsg_data(nlh); 2793 r->rtm_family = AF_INET; 2794 r->rtm_dst_len = 32; 2795 r->rtm_src_len = 0; 2796 r->rtm_tos = rt->rt_key_tos; 2797 r->rtm_table = RT_TABLE_MAIN; 2798 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN); 2799 r->rtm_type = rt->rt_type; 2800 r->rtm_scope = RT_SCOPE_UNIVERSE; 2801 r->rtm_protocol = RTPROT_UNSPEC; 2802 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2803 if (rt->rt_flags & RTCF_NOTIFY) 2804 r->rtm_flags |= RTM_F_NOTIFY; 2805 2806 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst); 2807 2808 if (rt->rt_key_src) { 2809 r->rtm_src_len = 32; 2810 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src); 2811 } 2812 if (rt->dst.dev) 2813 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex); 2814 #ifdef CONFIG_IP_ROUTE_CLASSID 2815 if (rt->dst.tclassid) 2816 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid); 2817 #endif 2818 if (rt_is_input_route(rt)) 2819 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); 2820 else if (rt->rt_src != rt->rt_key_src) 2821 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src); 2822 2823 if (rt->rt_dst != rt->rt_gateway) 2824 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway); 2825 2826 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 2827 goto nla_put_failure; 2828 2829 if (rt->rt_mark) 2830 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark); 2831 2832 error = rt->dst.error; 2833 if (peer) { 2834 inet_peer_refcheck(rt->peer); 2835 id = atomic_read(&peer->ip_id_count) & 0xffff; 2836 if (peer->tcp_ts_stamp) { 2837 ts = peer->tcp_ts; 2838 tsage = get_seconds() - peer->tcp_ts_stamp; 2839 } 2840 expires = ACCESS_ONCE(peer->pmtu_expires); 2841 if (expires) 2842 expires -= jiffies; 2843 } 2844 2845 if (rt_is_input_route(rt)) { 2846 #ifdef CONFIG_IP_MROUTE 2847 __be32 dst = rt->rt_dst; 2848 2849 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2850 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2851 int err = ipmr_get_route(net, skb, 2852 rt->rt_src, rt->rt_dst, 2853 r, nowait); 2854 if (err <= 0) { 2855 if (!nowait) { 2856 if (err == 0) 2857 return 0; 2858 goto nla_put_failure; 2859 } else { 2860 if (err == -EMSGSIZE) 2861 goto nla_put_failure; 2862 error = err; 2863 } 2864 } 2865 } else 2866 #endif 2867 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif); 2868 } 2869 2870 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage, 2871 expires, error) < 0) 2872 goto nla_put_failure; 2873 2874 return nlmsg_end(skb, nlh); 2875 2876 nla_put_failure: 2877 nlmsg_cancel(skb, nlh); 2878 return -EMSGSIZE; 2879 } 2880 2881 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2882 { 2883 struct net *net = sock_net(in_skb->sk); 2884 struct rtmsg *rtm; 2885 struct nlattr *tb[RTA_MAX+1]; 2886 struct rtable *rt = NULL; 2887 __be32 dst = 0; 2888 __be32 src = 0; 2889 u32 iif; 2890 int err; 2891 int mark; 2892 struct sk_buff *skb; 2893 2894 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2895 if (err < 0) 2896 goto errout; 2897 2898 rtm = nlmsg_data(nlh); 2899 2900 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2901 if (skb == NULL) { 2902 err = -ENOBUFS; 2903 goto errout; 2904 } 2905 2906 /* Reserve room for dummy headers, this skb can pass 2907 through good chunk of routing engine. 2908 */ 2909 skb_reset_mac_header(skb); 2910 skb_reset_network_header(skb); 2911 2912 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2913 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2914 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2915 2916 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2917 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2918 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2919 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2920 2921 if (iif) { 2922 struct net_device *dev; 2923 2924 dev = __dev_get_by_index(net, iif); 2925 if (dev == NULL) { 2926 err = -ENODEV; 2927 goto errout_free; 2928 } 2929 2930 skb->protocol = htons(ETH_P_IP); 2931 skb->dev = dev; 2932 skb->mark = mark; 2933 local_bh_disable(); 2934 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2935 local_bh_enable(); 2936 2937 rt = skb_rtable(skb); 2938 if (err == 0 && rt->dst.error) 2939 err = -rt->dst.error; 2940 } else { 2941 struct flowi4 fl4 = { 2942 .daddr = dst, 2943 .saddr = src, 2944 .flowi4_tos = rtm->rtm_tos, 2945 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, 2946 .flowi4_mark = mark, 2947 }; 2948 rt = ip_route_output_key(net, &fl4); 2949 2950 err = 0; 2951 if (IS_ERR(rt)) 2952 err = PTR_ERR(rt); 2953 } 2954 2955 if (err) 2956 goto errout_free; 2957 2958 skb_dst_set(skb, &rt->dst); 2959 if (rtm->rtm_flags & RTM_F_NOTIFY) 2960 rt->rt_flags |= RTCF_NOTIFY; 2961 2962 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 2963 RTM_NEWROUTE, 0, 0); 2964 if (err <= 0) 2965 goto errout_free; 2966 2967 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); 2968 errout: 2969 return err; 2970 2971 errout_free: 2972 kfree_skb(skb); 2973 goto errout; 2974 } 2975 2976 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) 2977 { 2978 struct rtable *rt; 2979 int h, s_h; 2980 int idx, s_idx; 2981 struct net *net; 2982 2983 net = sock_net(skb->sk); 2984 2985 s_h = cb->args[0]; 2986 if (s_h < 0) 2987 s_h = 0; 2988 s_idx = idx = cb->args[1]; 2989 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { 2990 if (!rt_hash_table[h].chain) 2991 continue; 2992 rcu_read_lock_bh(); 2993 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; 2994 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) { 2995 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx) 2996 continue; 2997 if (rt_is_expired(rt)) 2998 continue; 2999 skb_dst_set_noref(skb, &rt->dst); 3000 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, 3001 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 3002 1, NLM_F_MULTI) <= 0) { 3003 skb_dst_drop(skb); 3004 rcu_read_unlock_bh(); 3005 goto done; 3006 } 3007 skb_dst_drop(skb); 3008 } 3009 rcu_read_unlock_bh(); 3010 } 3011 3012 done: 3013 cb->args[0] = h; 3014 cb->args[1] = idx; 3015 return skb->len; 3016 } 3017 3018 void ip_rt_multicast_event(struct in_device *in_dev) 3019 { 3020 rt_cache_flush(dev_net(in_dev->dev), 0); 3021 } 3022 3023 #ifdef CONFIG_SYSCTL 3024 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, 3025 void __user *buffer, 3026 size_t *lenp, loff_t *ppos) 3027 { 3028 if (write) { 3029 int flush_delay; 3030 ctl_table ctl; 3031 struct net *net; 3032 3033 memcpy(&ctl, __ctl, sizeof(ctl)); 3034 ctl.data = &flush_delay; 3035 proc_dointvec(&ctl, write, buffer, lenp, ppos); 3036 3037 net = (struct net *)__ctl->extra1; 3038 rt_cache_flush(net, flush_delay); 3039 return 0; 3040 } 3041 3042 return -EINVAL; 3043 } 3044 3045 static ctl_table ipv4_route_table[] = { 3046 { 3047 .procname = "gc_thresh", 3048 .data = &ipv4_dst_ops.gc_thresh, 3049 .maxlen = sizeof(int), 3050 .mode = 0644, 3051 .proc_handler = proc_dointvec, 3052 }, 3053 { 3054 .procname = "max_size", 3055 .data = &ip_rt_max_size, 3056 .maxlen = sizeof(int), 3057 .mode = 0644, 3058 .proc_handler = proc_dointvec, 3059 }, 3060 { 3061 /* Deprecated. Use gc_min_interval_ms */ 3062 3063 .procname = "gc_min_interval", 3064 .data = &ip_rt_gc_min_interval, 3065 .maxlen = sizeof(int), 3066 .mode = 0644, 3067 .proc_handler = proc_dointvec_jiffies, 3068 }, 3069 { 3070 .procname = "gc_min_interval_ms", 3071 .data = &ip_rt_gc_min_interval, 3072 .maxlen = sizeof(int), 3073 .mode = 0644, 3074 .proc_handler = proc_dointvec_ms_jiffies, 3075 }, 3076 { 3077 .procname = "gc_timeout", 3078 .data = &ip_rt_gc_timeout, 3079 .maxlen = sizeof(int), 3080 .mode = 0644, 3081 .proc_handler = proc_dointvec_jiffies, 3082 }, 3083 { 3084 .procname = "gc_interval", 3085 .data = &ip_rt_gc_interval, 3086 .maxlen = sizeof(int), 3087 .mode = 0644, 3088 .proc_handler = proc_dointvec_jiffies, 3089 }, 3090 { 3091 .procname = "redirect_load", 3092 .data = &ip_rt_redirect_load, 3093 .maxlen = sizeof(int), 3094 .mode = 0644, 3095 .proc_handler = proc_dointvec, 3096 }, 3097 { 3098 .procname = "redirect_number", 3099 .data = &ip_rt_redirect_number, 3100 .maxlen = sizeof(int), 3101 .mode = 0644, 3102 .proc_handler = proc_dointvec, 3103 }, 3104 { 3105 .procname = "redirect_silence", 3106 .data = &ip_rt_redirect_silence, 3107 .maxlen = sizeof(int), 3108 .mode = 0644, 3109 .proc_handler = proc_dointvec, 3110 }, 3111 { 3112 .procname = "error_cost", 3113 .data = &ip_rt_error_cost, 3114 .maxlen = sizeof(int), 3115 .mode = 0644, 3116 .proc_handler = proc_dointvec, 3117 }, 3118 { 3119 .procname = "error_burst", 3120 .data = &ip_rt_error_burst, 3121 .maxlen = sizeof(int), 3122 .mode = 0644, 3123 .proc_handler = proc_dointvec, 3124 }, 3125 { 3126 .procname = "gc_elasticity", 3127 .data = &ip_rt_gc_elasticity, 3128 .maxlen = sizeof(int), 3129 .mode = 0644, 3130 .proc_handler = proc_dointvec, 3131 }, 3132 { 3133 .procname = "mtu_expires", 3134 .data = &ip_rt_mtu_expires, 3135 .maxlen = sizeof(int), 3136 .mode = 0644, 3137 .proc_handler = proc_dointvec_jiffies, 3138 }, 3139 { 3140 .procname = "min_pmtu", 3141 .data = &ip_rt_min_pmtu, 3142 .maxlen = sizeof(int), 3143 .mode = 0644, 3144 .proc_handler = proc_dointvec, 3145 }, 3146 { 3147 .procname = "min_adv_mss", 3148 .data = &ip_rt_min_advmss, 3149 .maxlen = sizeof(int), 3150 .mode = 0644, 3151 .proc_handler = proc_dointvec, 3152 }, 3153 { } 3154 }; 3155 3156 static struct ctl_table empty[1]; 3157 3158 static struct ctl_table ipv4_skeleton[] = 3159 { 3160 { .procname = "route", 3161 .mode = 0555, .child = ipv4_route_table}, 3162 { .procname = "neigh", 3163 .mode = 0555, .child = empty}, 3164 { } 3165 }; 3166 3167 static __net_initdata struct ctl_path ipv4_path[] = { 3168 { .procname = "net", }, 3169 { .procname = "ipv4", }, 3170 { }, 3171 }; 3172 3173 static struct ctl_table ipv4_route_flush_table[] = { 3174 { 3175 .procname = "flush", 3176 .maxlen = sizeof(int), 3177 .mode = 0200, 3178 .proc_handler = ipv4_sysctl_rtcache_flush, 3179 }, 3180 { }, 3181 }; 3182 3183 static __net_initdata struct ctl_path ipv4_route_path[] = { 3184 { .procname = "net", }, 3185 { .procname = "ipv4", }, 3186 { .procname = "route", }, 3187 { }, 3188 }; 3189 3190 static __net_init int sysctl_route_net_init(struct net *net) 3191 { 3192 struct ctl_table *tbl; 3193 3194 tbl = ipv4_route_flush_table; 3195 if (!net_eq(net, &init_net)) { 3196 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3197 if (tbl == NULL) 3198 goto err_dup; 3199 } 3200 tbl[0].extra1 = net; 3201 3202 net->ipv4.route_hdr = 3203 register_net_sysctl_table(net, ipv4_route_path, tbl); 3204 if (net->ipv4.route_hdr == NULL) 3205 goto err_reg; 3206 return 0; 3207 3208 err_reg: 3209 if (tbl != ipv4_route_flush_table) 3210 kfree(tbl); 3211 err_dup: 3212 return -ENOMEM; 3213 } 3214 3215 static __net_exit void sysctl_route_net_exit(struct net *net) 3216 { 3217 struct ctl_table *tbl; 3218 3219 tbl = net->ipv4.route_hdr->ctl_table_arg; 3220 unregister_net_sysctl_table(net->ipv4.route_hdr); 3221 BUG_ON(tbl == ipv4_route_flush_table); 3222 kfree(tbl); 3223 } 3224 3225 static __net_initdata struct pernet_operations sysctl_route_ops = { 3226 .init = sysctl_route_net_init, 3227 .exit = sysctl_route_net_exit, 3228 }; 3229 #endif 3230 3231 static __net_init int rt_genid_init(struct net *net) 3232 { 3233 get_random_bytes(&net->ipv4.rt_genid, 3234 sizeof(net->ipv4.rt_genid)); 3235 get_random_bytes(&net->ipv4.dev_addr_genid, 3236 sizeof(net->ipv4.dev_addr_genid)); 3237 return 0; 3238 } 3239 3240 static __net_initdata struct pernet_operations rt_genid_ops = { 3241 .init = rt_genid_init, 3242 }; 3243 3244 3245 #ifdef CONFIG_IP_ROUTE_CLASSID 3246 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3247 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3248 3249 static __initdata unsigned long rhash_entries; 3250 static int __init set_rhash_entries(char *str) 3251 { 3252 if (!str) 3253 return 0; 3254 rhash_entries = simple_strtoul(str, &str, 0); 3255 return 1; 3256 } 3257 __setup("rhash_entries=", set_rhash_entries); 3258 3259 int __init ip_rt_init(void) 3260 { 3261 int rc = 0; 3262 3263 #ifdef CONFIG_IP_ROUTE_CLASSID 3264 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3265 if (!ip_rt_acct) 3266 panic("IP: failed to allocate ip_rt_acct\n"); 3267 #endif 3268 3269 ipv4_dst_ops.kmem_cachep = 3270 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3271 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3272 3273 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3274 3275 if (dst_entries_init(&ipv4_dst_ops) < 0) 3276 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3277 3278 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3279 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3280 3281 rt_hash_table = (struct rt_hash_bucket *) 3282 alloc_large_system_hash("IP route cache", 3283 sizeof(struct rt_hash_bucket), 3284 rhash_entries, 3285 (totalram_pages >= 128 * 1024) ? 3286 15 : 17, 3287 0, 3288 &rt_hash_log, 3289 &rt_hash_mask, 3290 rhash_entries ? 0 : 512 * 1024); 3291 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); 3292 rt_hash_lock_init(); 3293 3294 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); 3295 ip_rt_max_size = (rt_hash_mask + 1) * 16; 3296 3297 devinet_init(); 3298 ip_fib_init(); 3299 3300 if (ip_rt_proc_init()) 3301 printk(KERN_ERR "Unable to create route proc files\n"); 3302 #ifdef CONFIG_XFRM 3303 xfrm_init(); 3304 xfrm4_init(ip_rt_max_size); 3305 #endif 3306 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL); 3307 3308 #ifdef CONFIG_SYSCTL 3309 register_pernet_subsys(&sysctl_route_ops); 3310 #endif 3311 register_pernet_subsys(&rt_genid_ops); 3312 return rc; 3313 } 3314 3315 #ifdef CONFIG_SYSCTL 3316 /* 3317 * We really need to sanitize the damn ipv4 init order, then all 3318 * this nonsense will go away. 3319 */ 3320 void __init ip_static_sysctl_init(void) 3321 { 3322 register_sysctl_paths(ipv4_path, ipv4_skeleton); 3323 } 3324 #endif 3325