1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * ROUTE - implementation of the IP router. 7 * 8 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Alan Cox, <gw4pts@gw4pts.ampr.org> 11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi> 12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 13 * 14 * Fixes: 15 * Alan Cox : Verify area fixes. 16 * Alan Cox : cli() protects routing changes 17 * Rui Oliveira : ICMP routing table updates 18 * (rco@di.uminho.pt) Routing table insertion and update 19 * Linus Torvalds : Rewrote bits to be sensible 20 * Alan Cox : Added BSD route gw semantics 21 * Alan Cox : Super /proc >4K 22 * Alan Cox : MTU in route table 23 * Alan Cox : MSS actually. Also added the window 24 * clamper. 25 * Sam Lantinga : Fixed route matching in rt_del() 26 * Alan Cox : Routing cache support. 27 * Alan Cox : Removed compatibility cruft. 28 * Alan Cox : RTF_REJECT support. 29 * Alan Cox : TCP irtt support. 30 * Jonathan Naylor : Added Metric support. 31 * Miquel van Smoorenburg : BSD API fixes. 32 * Miquel van Smoorenburg : Metrics. 33 * Alan Cox : Use __u32 properly 34 * Alan Cox : Aligned routing errors more closely with BSD 35 * our system is still very different. 36 * Alan Cox : Faster /proc handling 37 * Alexey Kuznetsov : Massive rework to support tree based routing, 38 * routing caches and better behaviour. 39 * 40 * Olaf Erb : irtt wasn't being copied right. 41 * Bjorn Ekwall : Kerneld route support. 42 * Alan Cox : Multicast fixed (I hope) 43 * Pavel Krauz : Limited broadcast fixed 44 * Mike McLagan : Routing by source 45 * Alexey Kuznetsov : End of old history. Split to fib.c and 46 * route.c and rewritten from scratch. 47 * Andi Kleen : Load-limit warning messages. 48 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow. 50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow. 51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful. 52 * Marc Boucher : routing by fwmark 53 * Robert Olsson : Added rt_cache statistics 54 * Arnaldo C. Melo : Convert proc stuff to seq_file 55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes. 56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect 57 * Ilia Sotnikov : Removed TOS from hash calculations 58 * 59 * This program is free software; you can redistribute it and/or 60 * modify it under the terms of the GNU General Public License 61 * as published by the Free Software Foundation; either version 62 * 2 of the License, or (at your option) any later version. 63 */ 64 65 #include <linux/module.h> 66 #include <asm/uaccess.h> 67 #include <asm/system.h> 68 #include <linux/bitops.h> 69 #include <linux/types.h> 70 #include <linux/kernel.h> 71 #include <linux/mm.h> 72 #include <linux/bootmem.h> 73 #include <linux/string.h> 74 #include <linux/socket.h> 75 #include <linux/sockios.h> 76 #include <linux/errno.h> 77 #include <linux/in.h> 78 #include <linux/inet.h> 79 #include <linux/netdevice.h> 80 #include <linux/proc_fs.h> 81 #include <linux/init.h> 82 #include <linux/workqueue.h> 83 #include <linux/skbuff.h> 84 #include <linux/inetdevice.h> 85 #include <linux/igmp.h> 86 #include <linux/pkt_sched.h> 87 #include <linux/mroute.h> 88 #include <linux/netfilter_ipv4.h> 89 #include <linux/random.h> 90 #include <linux/jhash.h> 91 #include <linux/rcupdate.h> 92 #include <linux/times.h> 93 #include <linux/slab.h> 94 #include <net/dst.h> 95 #include <net/net_namespace.h> 96 #include <net/protocol.h> 97 #include <net/ip.h> 98 #include <net/route.h> 99 #include <net/inetpeer.h> 100 #include <net/sock.h> 101 #include <net/ip_fib.h> 102 #include <net/arp.h> 103 #include <net/tcp.h> 104 #include <net/icmp.h> 105 #include <net/xfrm.h> 106 #include <net/netevent.h> 107 #include <net/rtnetlink.h> 108 #ifdef CONFIG_SYSCTL 109 #include <linux/sysctl.h> 110 #endif 111 #include <net/atmclip.h> 112 113 #define RT_FL_TOS(oldflp4) \ 114 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))) 115 116 #define IP_MAX_MTU 0xFFF0 117 118 #define RT_GC_TIMEOUT (300*HZ) 119 120 static int ip_rt_max_size; 121 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 122 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 123 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 124 static int ip_rt_redirect_number __read_mostly = 9; 125 static int ip_rt_redirect_load __read_mostly = HZ / 50; 126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 127 static int ip_rt_error_cost __read_mostly = HZ; 128 static int ip_rt_error_burst __read_mostly = 5 * HZ; 129 static int ip_rt_gc_elasticity __read_mostly = 8; 130 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 131 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 132 static int ip_rt_min_advmss __read_mostly = 256; 133 static int rt_chain_length_max __read_mostly = 20; 134 135 /* 136 * Interface to generic destination cache. 137 */ 138 139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst); 141 static unsigned int ipv4_default_mtu(const struct dst_entry *dst); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 144 static void ipv4_link_failure(struct sk_buff *skb); 145 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 146 static int rt_garbage_collect(struct dst_ops *ops); 147 148 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 149 int how) 150 { 151 } 152 153 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old) 154 { 155 struct rtable *rt = (struct rtable *) dst; 156 struct inet_peer *peer; 157 u32 *p = NULL; 158 159 if (!rt->peer) 160 rt_bind_peer(rt, rt->rt_dst, 1); 161 162 peer = rt->peer; 163 if (peer) { 164 u32 *old_p = __DST_METRICS_PTR(old); 165 unsigned long prev, new; 166 167 p = peer->metrics; 168 if (inet_metrics_new(peer)) 169 memcpy(p, old_p, sizeof(u32) * RTAX_MAX); 170 171 new = (unsigned long) p; 172 prev = cmpxchg(&dst->_metrics, old, new); 173 174 if (prev != old) { 175 p = __DST_METRICS_PTR(prev); 176 if (prev & DST_METRICS_READ_ONLY) 177 p = NULL; 178 } else { 179 if (rt->fi) { 180 fib_info_put(rt->fi); 181 rt->fi = NULL; 182 } 183 } 184 } 185 return p; 186 } 187 188 static struct dst_ops ipv4_dst_ops = { 189 .family = AF_INET, 190 .protocol = cpu_to_be16(ETH_P_IP), 191 .gc = rt_garbage_collect, 192 .check = ipv4_dst_check, 193 .default_advmss = ipv4_default_advmss, 194 .default_mtu = ipv4_default_mtu, 195 .cow_metrics = ipv4_cow_metrics, 196 .destroy = ipv4_dst_destroy, 197 .ifdown = ipv4_dst_ifdown, 198 .negative_advice = ipv4_negative_advice, 199 .link_failure = ipv4_link_failure, 200 .update_pmtu = ip_rt_update_pmtu, 201 .local_out = __ip_local_out, 202 }; 203 204 #define ECN_OR_COST(class) TC_PRIO_##class 205 206 const __u8 ip_tos2prio[16] = { 207 TC_PRIO_BESTEFFORT, 208 ECN_OR_COST(BESTEFFORT), 209 TC_PRIO_BESTEFFORT, 210 ECN_OR_COST(BESTEFFORT), 211 TC_PRIO_BULK, 212 ECN_OR_COST(BULK), 213 TC_PRIO_BULK, 214 ECN_OR_COST(BULK), 215 TC_PRIO_INTERACTIVE, 216 ECN_OR_COST(INTERACTIVE), 217 TC_PRIO_INTERACTIVE, 218 ECN_OR_COST(INTERACTIVE), 219 TC_PRIO_INTERACTIVE_BULK, 220 ECN_OR_COST(INTERACTIVE_BULK), 221 TC_PRIO_INTERACTIVE_BULK, 222 ECN_OR_COST(INTERACTIVE_BULK) 223 }; 224 225 226 /* 227 * Route cache. 228 */ 229 230 /* The locking scheme is rather straight forward: 231 * 232 * 1) Read-Copy Update protects the buckets of the central route hash. 233 * 2) Only writers remove entries, and they hold the lock 234 * as they look at rtable reference counts. 235 * 3) Only readers acquire references to rtable entries, 236 * they do so with atomic increments and with the 237 * lock held. 238 */ 239 240 struct rt_hash_bucket { 241 struct rtable __rcu *chain; 242 }; 243 244 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ 245 defined(CONFIG_PROVE_LOCKING) 246 /* 247 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks 248 * The size of this table is a power of two and depends on the number of CPUS. 249 * (on lockdep we have a quite big spinlock_t, so keep the size down there) 250 */ 251 #ifdef CONFIG_LOCKDEP 252 # define RT_HASH_LOCK_SZ 256 253 #else 254 # if NR_CPUS >= 32 255 # define RT_HASH_LOCK_SZ 4096 256 # elif NR_CPUS >= 16 257 # define RT_HASH_LOCK_SZ 2048 258 # elif NR_CPUS >= 8 259 # define RT_HASH_LOCK_SZ 1024 260 # elif NR_CPUS >= 4 261 # define RT_HASH_LOCK_SZ 512 262 # else 263 # define RT_HASH_LOCK_SZ 256 264 # endif 265 #endif 266 267 static spinlock_t *rt_hash_locks; 268 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)] 269 270 static __init void rt_hash_lock_init(void) 271 { 272 int i; 273 274 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, 275 GFP_KERNEL); 276 if (!rt_hash_locks) 277 panic("IP: failed to allocate rt_hash_locks\n"); 278 279 for (i = 0; i < RT_HASH_LOCK_SZ; i++) 280 spin_lock_init(&rt_hash_locks[i]); 281 } 282 #else 283 # define rt_hash_lock_addr(slot) NULL 284 285 static inline void rt_hash_lock_init(void) 286 { 287 } 288 #endif 289 290 static struct rt_hash_bucket *rt_hash_table __read_mostly; 291 static unsigned rt_hash_mask __read_mostly; 292 static unsigned int rt_hash_log __read_mostly; 293 294 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 295 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) 296 297 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, 298 int genid) 299 { 300 return jhash_3words((__force u32)daddr, (__force u32)saddr, 301 idx, genid) 302 & rt_hash_mask; 303 } 304 305 static inline int rt_genid(struct net *net) 306 { 307 return atomic_read(&net->ipv4.rt_genid); 308 } 309 310 #ifdef CONFIG_PROC_FS 311 struct rt_cache_iter_state { 312 struct seq_net_private p; 313 int bucket; 314 int genid; 315 }; 316 317 static struct rtable *rt_cache_get_first(struct seq_file *seq) 318 { 319 struct rt_cache_iter_state *st = seq->private; 320 struct rtable *r = NULL; 321 322 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { 323 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain)) 324 continue; 325 rcu_read_lock_bh(); 326 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); 327 while (r) { 328 if (dev_net(r->dst.dev) == seq_file_net(seq) && 329 r->rt_genid == st->genid) 330 return r; 331 r = rcu_dereference_bh(r->dst.rt_next); 332 } 333 rcu_read_unlock_bh(); 334 } 335 return r; 336 } 337 338 static struct rtable *__rt_cache_get_next(struct seq_file *seq, 339 struct rtable *r) 340 { 341 struct rt_cache_iter_state *st = seq->private; 342 343 r = rcu_dereference_bh(r->dst.rt_next); 344 while (!r) { 345 rcu_read_unlock_bh(); 346 do { 347 if (--st->bucket < 0) 348 return NULL; 349 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain)); 350 rcu_read_lock_bh(); 351 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain); 352 } 353 return r; 354 } 355 356 static struct rtable *rt_cache_get_next(struct seq_file *seq, 357 struct rtable *r) 358 { 359 struct rt_cache_iter_state *st = seq->private; 360 while ((r = __rt_cache_get_next(seq, r)) != NULL) { 361 if (dev_net(r->dst.dev) != seq_file_net(seq)) 362 continue; 363 if (r->rt_genid == st->genid) 364 break; 365 } 366 return r; 367 } 368 369 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos) 370 { 371 struct rtable *r = rt_cache_get_first(seq); 372 373 if (r) 374 while (pos && (r = rt_cache_get_next(seq, r))) 375 --pos; 376 return pos ? NULL : r; 377 } 378 379 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 380 { 381 struct rt_cache_iter_state *st = seq->private; 382 if (*pos) 383 return rt_cache_get_idx(seq, *pos - 1); 384 st->genid = rt_genid(seq_file_net(seq)); 385 return SEQ_START_TOKEN; 386 } 387 388 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 389 { 390 struct rtable *r; 391 392 if (v == SEQ_START_TOKEN) 393 r = rt_cache_get_first(seq); 394 else 395 r = rt_cache_get_next(seq, v); 396 ++*pos; 397 return r; 398 } 399 400 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 401 { 402 if (v && v != SEQ_START_TOKEN) 403 rcu_read_unlock_bh(); 404 } 405 406 static int rt_cache_seq_show(struct seq_file *seq, void *v) 407 { 408 if (v == SEQ_START_TOKEN) 409 seq_printf(seq, "%-127s\n", 410 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 411 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 412 "HHUptod\tSpecDst"); 413 else { 414 struct rtable *r = v; 415 int len; 416 417 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t" 418 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", 419 r->dst.dev ? r->dst.dev->name : "*", 420 (__force u32)r->rt_dst, 421 (__force u32)r->rt_gateway, 422 r->rt_flags, atomic_read(&r->dst.__refcnt), 423 r->dst.__use, 0, (__force u32)r->rt_src, 424 dst_metric_advmss(&r->dst) + 40, 425 dst_metric(&r->dst, RTAX_WINDOW), 426 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) + 427 dst_metric(&r->dst, RTAX_RTTVAR)), 428 r->rt_key_tos, 429 -1, 430 (r->dst.neighbour ? 431 (r->dst.neighbour->hh.hh_output == 432 dev_queue_xmit) : 0), 433 r->rt_spec_dst, &len); 434 435 seq_printf(seq, "%*s\n", 127 - len, ""); 436 } 437 return 0; 438 } 439 440 static const struct seq_operations rt_cache_seq_ops = { 441 .start = rt_cache_seq_start, 442 .next = rt_cache_seq_next, 443 .stop = rt_cache_seq_stop, 444 .show = rt_cache_seq_show, 445 }; 446 447 static int rt_cache_seq_open(struct inode *inode, struct file *file) 448 { 449 return seq_open_net(inode, file, &rt_cache_seq_ops, 450 sizeof(struct rt_cache_iter_state)); 451 } 452 453 static const struct file_operations rt_cache_seq_fops = { 454 .owner = THIS_MODULE, 455 .open = rt_cache_seq_open, 456 .read = seq_read, 457 .llseek = seq_lseek, 458 .release = seq_release_net, 459 }; 460 461 462 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 463 { 464 int cpu; 465 466 if (*pos == 0) 467 return SEQ_START_TOKEN; 468 469 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 470 if (!cpu_possible(cpu)) 471 continue; 472 *pos = cpu+1; 473 return &per_cpu(rt_cache_stat, cpu); 474 } 475 return NULL; 476 } 477 478 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 479 { 480 int cpu; 481 482 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 483 if (!cpu_possible(cpu)) 484 continue; 485 *pos = cpu+1; 486 return &per_cpu(rt_cache_stat, cpu); 487 } 488 return NULL; 489 490 } 491 492 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 493 { 494 495 } 496 497 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 498 { 499 struct rt_cache_stat *st = v; 500 501 if (v == SEQ_START_TOKEN) { 502 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"); 503 return 0; 504 } 505 506 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 507 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 508 dst_entries_get_slow(&ipv4_dst_ops), 509 st->in_hit, 510 st->in_slow_tot, 511 st->in_slow_mc, 512 st->in_no_route, 513 st->in_brd, 514 st->in_martian_dst, 515 st->in_martian_src, 516 517 st->out_hit, 518 st->out_slow_tot, 519 st->out_slow_mc, 520 521 st->gc_total, 522 st->gc_ignored, 523 st->gc_goal_miss, 524 st->gc_dst_overflow, 525 st->in_hlist_search, 526 st->out_hlist_search 527 ); 528 return 0; 529 } 530 531 static const struct seq_operations rt_cpu_seq_ops = { 532 .start = rt_cpu_seq_start, 533 .next = rt_cpu_seq_next, 534 .stop = rt_cpu_seq_stop, 535 .show = rt_cpu_seq_show, 536 }; 537 538 539 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 540 { 541 return seq_open(file, &rt_cpu_seq_ops); 542 } 543 544 static const struct file_operations rt_cpu_seq_fops = { 545 .owner = THIS_MODULE, 546 .open = rt_cpu_seq_open, 547 .read = seq_read, 548 .llseek = seq_lseek, 549 .release = seq_release, 550 }; 551 552 #ifdef CONFIG_IP_ROUTE_CLASSID 553 static int rt_acct_proc_show(struct seq_file *m, void *v) 554 { 555 struct ip_rt_acct *dst, *src; 556 unsigned int i, j; 557 558 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL); 559 if (!dst) 560 return -ENOMEM; 561 562 for_each_possible_cpu(i) { 563 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i); 564 for (j = 0; j < 256; j++) { 565 dst[j].o_bytes += src[j].o_bytes; 566 dst[j].o_packets += src[j].o_packets; 567 dst[j].i_bytes += src[j].i_bytes; 568 dst[j].i_packets += src[j].i_packets; 569 } 570 } 571 572 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct)); 573 kfree(dst); 574 return 0; 575 } 576 577 static int rt_acct_proc_open(struct inode *inode, struct file *file) 578 { 579 return single_open(file, rt_acct_proc_show, NULL); 580 } 581 582 static const struct file_operations rt_acct_proc_fops = { 583 .owner = THIS_MODULE, 584 .open = rt_acct_proc_open, 585 .read = seq_read, 586 .llseek = seq_lseek, 587 .release = single_release, 588 }; 589 #endif 590 591 static int __net_init ip_rt_do_proc_init(struct net *net) 592 { 593 struct proc_dir_entry *pde; 594 595 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO, 596 &rt_cache_seq_fops); 597 if (!pde) 598 goto err1; 599 600 pde = proc_create("rt_cache", S_IRUGO, 601 net->proc_net_stat, &rt_cpu_seq_fops); 602 if (!pde) 603 goto err2; 604 605 #ifdef CONFIG_IP_ROUTE_CLASSID 606 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops); 607 if (!pde) 608 goto err3; 609 #endif 610 return 0; 611 612 #ifdef CONFIG_IP_ROUTE_CLASSID 613 err3: 614 remove_proc_entry("rt_cache", net->proc_net_stat); 615 #endif 616 err2: 617 remove_proc_entry("rt_cache", net->proc_net); 618 err1: 619 return -ENOMEM; 620 } 621 622 static void __net_exit ip_rt_do_proc_exit(struct net *net) 623 { 624 remove_proc_entry("rt_cache", net->proc_net_stat); 625 remove_proc_entry("rt_cache", net->proc_net); 626 #ifdef CONFIG_IP_ROUTE_CLASSID 627 remove_proc_entry("rt_acct", net->proc_net); 628 #endif 629 } 630 631 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 632 .init = ip_rt_do_proc_init, 633 .exit = ip_rt_do_proc_exit, 634 }; 635 636 static int __init ip_rt_proc_init(void) 637 { 638 return register_pernet_subsys(&ip_rt_proc_ops); 639 } 640 641 #else 642 static inline int ip_rt_proc_init(void) 643 { 644 return 0; 645 } 646 #endif /* CONFIG_PROC_FS */ 647 648 static inline void rt_free(struct rtable *rt) 649 { 650 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 651 } 652 653 static inline void rt_drop(struct rtable *rt) 654 { 655 ip_rt_put(rt); 656 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free); 657 } 658 659 static inline int rt_fast_clean(struct rtable *rth) 660 { 661 /* Kill broadcast/multicast entries very aggresively, if they 662 collide in hash table with more useful entries */ 663 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) && 664 rt_is_input_route(rth) && rth->dst.rt_next; 665 } 666 667 static inline int rt_valuable(struct rtable *rth) 668 { 669 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || 670 (rth->peer && rth->peer->pmtu_expires); 671 } 672 673 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2) 674 { 675 unsigned long age; 676 int ret = 0; 677 678 if (atomic_read(&rth->dst.__refcnt)) 679 goto out; 680 681 age = jiffies - rth->dst.lastuse; 682 if ((age <= tmo1 && !rt_fast_clean(rth)) || 683 (age <= tmo2 && rt_valuable(rth))) 684 goto out; 685 ret = 1; 686 out: return ret; 687 } 688 689 /* Bits of score are: 690 * 31: very valuable 691 * 30: not quite useless 692 * 29..0: usage counter 693 */ 694 static inline u32 rt_score(struct rtable *rt) 695 { 696 u32 score = jiffies - rt->dst.lastuse; 697 698 score = ~score & ~(3<<30); 699 700 if (rt_valuable(rt)) 701 score |= (1<<31); 702 703 if (rt_is_output_route(rt) || 704 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) 705 score |= (1<<30); 706 707 return score; 708 } 709 710 static inline bool rt_caching(const struct net *net) 711 { 712 return net->ipv4.current_rt_cache_rebuild_count <= 713 net->ipv4.sysctl_rt_cache_rebuild_count; 714 } 715 716 static inline bool compare_hash_inputs(const struct rtable *rt1, 717 const struct rtable *rt2) 718 { 719 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | 720 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | 721 (rt1->rt_iif ^ rt2->rt_iif)) == 0); 722 } 723 724 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2) 725 { 726 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) | 727 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) | 728 (rt1->rt_mark ^ rt2->rt_mark) | 729 (rt1->rt_key_tos ^ rt2->rt_key_tos) | 730 (rt1->rt_oif ^ rt2->rt_oif) | 731 (rt1->rt_iif ^ rt2->rt_iif)) == 0; 732 } 733 734 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) 735 { 736 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev)); 737 } 738 739 static inline int rt_is_expired(struct rtable *rth) 740 { 741 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); 742 } 743 744 /* 745 * Perform a full scan of hash table and free all entries. 746 * Can be called by a softirq or a process. 747 * In the later case, we want to be reschedule if necessary 748 */ 749 static void rt_do_flush(struct net *net, int process_context) 750 { 751 unsigned int i; 752 struct rtable *rth, *next; 753 754 for (i = 0; i <= rt_hash_mask; i++) { 755 struct rtable __rcu **pprev; 756 struct rtable *list; 757 758 if (process_context && need_resched()) 759 cond_resched(); 760 rth = rcu_dereference_raw(rt_hash_table[i].chain); 761 if (!rth) 762 continue; 763 764 spin_lock_bh(rt_hash_lock_addr(i)); 765 766 list = NULL; 767 pprev = &rt_hash_table[i].chain; 768 rth = rcu_dereference_protected(*pprev, 769 lockdep_is_held(rt_hash_lock_addr(i))); 770 771 while (rth) { 772 next = rcu_dereference_protected(rth->dst.rt_next, 773 lockdep_is_held(rt_hash_lock_addr(i))); 774 775 if (!net || 776 net_eq(dev_net(rth->dst.dev), net)) { 777 rcu_assign_pointer(*pprev, next); 778 rcu_assign_pointer(rth->dst.rt_next, list); 779 list = rth; 780 } else { 781 pprev = &rth->dst.rt_next; 782 } 783 rth = next; 784 } 785 786 spin_unlock_bh(rt_hash_lock_addr(i)); 787 788 for (; list; list = next) { 789 next = rcu_dereference_protected(list->dst.rt_next, 1); 790 rt_free(list); 791 } 792 } 793 } 794 795 /* 796 * While freeing expired entries, we compute average chain length 797 * and standard deviation, using fixed-point arithmetic. 798 * This to have an estimation of rt_chain_length_max 799 * rt_chain_length_max = max(elasticity, AVG + 4*SD) 800 * We use 3 bits for frational part, and 29 (or 61) for magnitude. 801 */ 802 803 #define FRACT_BITS 3 804 #define ONE (1UL << FRACT_BITS) 805 806 /* 807 * Given a hash chain and an item in this hash chain, 808 * find if a previous entry has the same hash_inputs 809 * (but differs on tos, mark or oif) 810 * Returns 0 if an alias is found. 811 * Returns ONE if rth has no alias before itself. 812 */ 813 static int has_noalias(const struct rtable *head, const struct rtable *rth) 814 { 815 const struct rtable *aux = head; 816 817 while (aux != rth) { 818 if (compare_hash_inputs(aux, rth)) 819 return 0; 820 aux = rcu_dereference_protected(aux->dst.rt_next, 1); 821 } 822 return ONE; 823 } 824 825 /* 826 * Perturbation of rt_genid by a small quantity [1..256] 827 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() 828 * many times (2^24) without giving recent rt_genid. 829 * Jenkins hash is strong enough that litle changes of rt_genid are OK. 830 */ 831 static void rt_cache_invalidate(struct net *net) 832 { 833 unsigned char shuffle; 834 835 get_random_bytes(&shuffle, sizeof(shuffle)); 836 atomic_add(shuffle + 1U, &net->ipv4.rt_genid); 837 } 838 839 /* 840 * delay < 0 : invalidate cache (fast : entries will be deleted later) 841 * delay >= 0 : invalidate & flush cache (can be long) 842 */ 843 void rt_cache_flush(struct net *net, int delay) 844 { 845 rt_cache_invalidate(net); 846 if (delay >= 0) 847 rt_do_flush(net, !in_softirq()); 848 } 849 850 /* Flush previous cache invalidated entries from the cache */ 851 void rt_cache_flush_batch(struct net *net) 852 { 853 rt_do_flush(net, !in_softirq()); 854 } 855 856 static void rt_emergency_hash_rebuild(struct net *net) 857 { 858 if (net_ratelimit()) 859 printk(KERN_WARNING "Route hash chain too long!\n"); 860 rt_cache_invalidate(net); 861 } 862 863 /* 864 Short description of GC goals. 865 866 We want to build algorithm, which will keep routing cache 867 at some equilibrium point, when number of aged off entries 868 is kept approximately equal to newly generated ones. 869 870 Current expiration strength is variable "expire". 871 We try to adjust it dynamically, so that if networking 872 is idle expires is large enough to keep enough of warm entries, 873 and when load increases it reduces to limit cache size. 874 */ 875 876 static int rt_garbage_collect(struct dst_ops *ops) 877 { 878 static unsigned long expire = RT_GC_TIMEOUT; 879 static unsigned long last_gc; 880 static int rover; 881 static int equilibrium; 882 struct rtable *rth; 883 struct rtable __rcu **rthp; 884 unsigned long now = jiffies; 885 int goal; 886 int entries = dst_entries_get_fast(&ipv4_dst_ops); 887 888 /* 889 * Garbage collection is pretty expensive, 890 * do not make it too frequently. 891 */ 892 893 RT_CACHE_STAT_INC(gc_total); 894 895 if (now - last_gc < ip_rt_gc_min_interval && 896 entries < ip_rt_max_size) { 897 RT_CACHE_STAT_INC(gc_ignored); 898 goto out; 899 } 900 901 entries = dst_entries_get_slow(&ipv4_dst_ops); 902 /* Calculate number of entries, which we want to expire now. */ 903 goal = entries - (ip_rt_gc_elasticity << rt_hash_log); 904 if (goal <= 0) { 905 if (equilibrium < ipv4_dst_ops.gc_thresh) 906 equilibrium = ipv4_dst_ops.gc_thresh; 907 goal = entries - equilibrium; 908 if (goal > 0) { 909 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); 910 goal = entries - equilibrium; 911 } 912 } else { 913 /* We are in dangerous area. Try to reduce cache really 914 * aggressively. 915 */ 916 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1); 917 equilibrium = entries - goal; 918 } 919 920 if (now - last_gc >= ip_rt_gc_min_interval) 921 last_gc = now; 922 923 if (goal <= 0) { 924 equilibrium += goal; 925 goto work_done; 926 } 927 928 do { 929 int i, k; 930 931 for (i = rt_hash_mask, k = rover; i >= 0; i--) { 932 unsigned long tmo = expire; 933 934 k = (k + 1) & rt_hash_mask; 935 rthp = &rt_hash_table[k].chain; 936 spin_lock_bh(rt_hash_lock_addr(k)); 937 while ((rth = rcu_dereference_protected(*rthp, 938 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) { 939 if (!rt_is_expired(rth) && 940 !rt_may_expire(rth, tmo, expire)) { 941 tmo >>= 1; 942 rthp = &rth->dst.rt_next; 943 continue; 944 } 945 *rthp = rth->dst.rt_next; 946 rt_free(rth); 947 goal--; 948 } 949 spin_unlock_bh(rt_hash_lock_addr(k)); 950 if (goal <= 0) 951 break; 952 } 953 rover = k; 954 955 if (goal <= 0) 956 goto work_done; 957 958 /* Goal is not achieved. We stop process if: 959 960 - if expire reduced to zero. Otherwise, expire is halfed. 961 - if table is not full. 962 - if we are called from interrupt. 963 - jiffies check is just fallback/debug loop breaker. 964 We will not spin here for long time in any case. 965 */ 966 967 RT_CACHE_STAT_INC(gc_goal_miss); 968 969 if (expire == 0) 970 break; 971 972 expire >>= 1; 973 974 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) 975 goto out; 976 } while (!in_softirq() && time_before_eq(jiffies, now)); 977 978 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size) 979 goto out; 980 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size) 981 goto out; 982 if (net_ratelimit()) 983 printk(KERN_WARNING "dst cache overflow\n"); 984 RT_CACHE_STAT_INC(gc_dst_overflow); 985 return 1; 986 987 work_done: 988 expire += ip_rt_gc_min_interval; 989 if (expire > ip_rt_gc_timeout || 990 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh || 991 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh) 992 expire = ip_rt_gc_timeout; 993 out: return 0; 994 } 995 996 /* 997 * Returns number of entries in a hash chain that have different hash_inputs 998 */ 999 static int slow_chain_length(const struct rtable *head) 1000 { 1001 int length = 0; 1002 const struct rtable *rth = head; 1003 1004 while (rth) { 1005 length += has_noalias(head, rth); 1006 rth = rcu_dereference_protected(rth->dst.rt_next, 1); 1007 } 1008 return length >> FRACT_BITS; 1009 } 1010 1011 static int rt_bind_neighbour(struct rtable *rt) 1012 { 1013 static const __be32 inaddr_any = 0; 1014 struct net_device *dev = rt->dst.dev; 1015 struct neigh_table *tbl = &arp_tbl; 1016 const __be32 *nexthop; 1017 struct neighbour *n; 1018 1019 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1020 if (dev->type == ARPHRD_ATM) 1021 tbl = clip_tbl_hook; 1022 #endif 1023 nexthop = &rt->rt_gateway; 1024 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) 1025 nexthop = &inaddr_any; 1026 n = ipv4_neigh_lookup(tbl, dev, nexthop); 1027 if (IS_ERR(n)) 1028 return PTR_ERR(n); 1029 rt->dst.neighbour = n; 1030 1031 return 0; 1032 } 1033 1034 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt, 1035 struct sk_buff *skb, int ifindex) 1036 { 1037 struct rtable *rth, *cand; 1038 struct rtable __rcu **rthp, **candp; 1039 unsigned long now; 1040 u32 min_score; 1041 int chain_length; 1042 int attempts = !in_softirq(); 1043 1044 restart: 1045 chain_length = 0; 1046 min_score = ~(u32)0; 1047 cand = NULL; 1048 candp = NULL; 1049 now = jiffies; 1050 1051 if (!rt_caching(dev_net(rt->dst.dev))) { 1052 /* 1053 * If we're not caching, just tell the caller we 1054 * were successful and don't touch the route. The 1055 * caller hold the sole reference to the cache entry, and 1056 * it will be released when the caller is done with it. 1057 * If we drop it here, the callers have no way to resolve routes 1058 * when we're not caching. Instead, just point *rp at rt, so 1059 * the caller gets a single use out of the route 1060 * Note that we do rt_free on this new route entry, so that 1061 * once its refcount hits zero, we are still able to reap it 1062 * (Thanks Alexey) 1063 * Note: To avoid expensive rcu stuff for this uncached dst, 1064 * we set DST_NOCACHE so that dst_release() can free dst without 1065 * waiting a grace period. 1066 */ 1067 1068 rt->dst.flags |= DST_NOCACHE; 1069 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { 1070 int err = rt_bind_neighbour(rt); 1071 if (err) { 1072 if (net_ratelimit()) 1073 printk(KERN_WARNING 1074 "Neighbour table failure & not caching routes.\n"); 1075 ip_rt_put(rt); 1076 return ERR_PTR(err); 1077 } 1078 } 1079 1080 goto skip_hashing; 1081 } 1082 1083 rthp = &rt_hash_table[hash].chain; 1084 1085 spin_lock_bh(rt_hash_lock_addr(hash)); 1086 while ((rth = rcu_dereference_protected(*rthp, 1087 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { 1088 if (rt_is_expired(rth)) { 1089 *rthp = rth->dst.rt_next; 1090 rt_free(rth); 1091 continue; 1092 } 1093 if (compare_keys(rth, rt) && compare_netns(rth, rt)) { 1094 /* Put it first */ 1095 *rthp = rth->dst.rt_next; 1096 /* 1097 * Since lookup is lockfree, the deletion 1098 * must be visible to another weakly ordered CPU before 1099 * the insertion at the start of the hash chain. 1100 */ 1101 rcu_assign_pointer(rth->dst.rt_next, 1102 rt_hash_table[hash].chain); 1103 /* 1104 * Since lookup is lockfree, the update writes 1105 * must be ordered for consistency on SMP. 1106 */ 1107 rcu_assign_pointer(rt_hash_table[hash].chain, rth); 1108 1109 dst_use(&rth->dst, now); 1110 spin_unlock_bh(rt_hash_lock_addr(hash)); 1111 1112 rt_drop(rt); 1113 if (skb) 1114 skb_dst_set(skb, &rth->dst); 1115 return rth; 1116 } 1117 1118 if (!atomic_read(&rth->dst.__refcnt)) { 1119 u32 score = rt_score(rth); 1120 1121 if (score <= min_score) { 1122 cand = rth; 1123 candp = rthp; 1124 min_score = score; 1125 } 1126 } 1127 1128 chain_length++; 1129 1130 rthp = &rth->dst.rt_next; 1131 } 1132 1133 if (cand) { 1134 /* ip_rt_gc_elasticity used to be average length of chain 1135 * length, when exceeded gc becomes really aggressive. 1136 * 1137 * The second limit is less certain. At the moment it allows 1138 * only 2 entries per bucket. We will see. 1139 */ 1140 if (chain_length > ip_rt_gc_elasticity) { 1141 *candp = cand->dst.rt_next; 1142 rt_free(cand); 1143 } 1144 } else { 1145 if (chain_length > rt_chain_length_max && 1146 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) { 1147 struct net *net = dev_net(rt->dst.dev); 1148 int num = ++net->ipv4.current_rt_cache_rebuild_count; 1149 if (!rt_caching(net)) { 1150 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n", 1151 rt->dst.dev->name, num); 1152 } 1153 rt_emergency_hash_rebuild(net); 1154 spin_unlock_bh(rt_hash_lock_addr(hash)); 1155 1156 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1157 ifindex, rt_genid(net)); 1158 goto restart; 1159 } 1160 } 1161 1162 /* Try to bind route to arp only if it is output 1163 route or unicast forwarding path. 1164 */ 1165 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) { 1166 int err = rt_bind_neighbour(rt); 1167 if (err) { 1168 spin_unlock_bh(rt_hash_lock_addr(hash)); 1169 1170 if (err != -ENOBUFS) { 1171 rt_drop(rt); 1172 return ERR_PTR(err); 1173 } 1174 1175 /* Neighbour tables are full and nothing 1176 can be released. Try to shrink route cache, 1177 it is most likely it holds some neighbour records. 1178 */ 1179 if (attempts-- > 0) { 1180 int saved_elasticity = ip_rt_gc_elasticity; 1181 int saved_int = ip_rt_gc_min_interval; 1182 ip_rt_gc_elasticity = 1; 1183 ip_rt_gc_min_interval = 0; 1184 rt_garbage_collect(&ipv4_dst_ops); 1185 ip_rt_gc_min_interval = saved_int; 1186 ip_rt_gc_elasticity = saved_elasticity; 1187 goto restart; 1188 } 1189 1190 if (net_ratelimit()) 1191 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n"); 1192 rt_drop(rt); 1193 return ERR_PTR(-ENOBUFS); 1194 } 1195 } 1196 1197 rt->dst.rt_next = rt_hash_table[hash].chain; 1198 1199 /* 1200 * Since lookup is lockfree, we must make sure 1201 * previous writes to rt are committed to memory 1202 * before making rt visible to other CPUS. 1203 */ 1204 rcu_assign_pointer(rt_hash_table[hash].chain, rt); 1205 1206 spin_unlock_bh(rt_hash_lock_addr(hash)); 1207 1208 skip_hashing: 1209 if (skb) 1210 skb_dst_set(skb, &rt->dst); 1211 return rt; 1212 } 1213 1214 static atomic_t __rt_peer_genid = ATOMIC_INIT(0); 1215 1216 static u32 rt_peer_genid(void) 1217 { 1218 return atomic_read(&__rt_peer_genid); 1219 } 1220 1221 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create) 1222 { 1223 struct inet_peer *peer; 1224 1225 peer = inet_getpeer_v4(daddr, create); 1226 1227 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL) 1228 inet_putpeer(peer); 1229 else 1230 rt->rt_peer_genid = rt_peer_genid(); 1231 } 1232 1233 /* 1234 * Peer allocation may fail only in serious out-of-memory conditions. However 1235 * we still can generate some output. 1236 * Random ID selection looks a bit dangerous because we have no chances to 1237 * select ID being unique in a reasonable period of time. 1238 * But broken packet identifier may be better than no packet at all. 1239 */ 1240 static void ip_select_fb_ident(struct iphdr *iph) 1241 { 1242 static DEFINE_SPINLOCK(ip_fb_id_lock); 1243 static u32 ip_fallback_id; 1244 u32 salt; 1245 1246 spin_lock_bh(&ip_fb_id_lock); 1247 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); 1248 iph->id = htons(salt & 0xFFFF); 1249 ip_fallback_id = salt; 1250 spin_unlock_bh(&ip_fb_id_lock); 1251 } 1252 1253 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) 1254 { 1255 struct rtable *rt = (struct rtable *) dst; 1256 1257 if (rt) { 1258 if (rt->peer == NULL) 1259 rt_bind_peer(rt, rt->rt_dst, 1); 1260 1261 /* If peer is attached to destination, it is never detached, 1262 so that we need not to grab a lock to dereference it. 1263 */ 1264 if (rt->peer) { 1265 iph->id = htons(inet_getid(rt->peer, more)); 1266 return; 1267 } 1268 } else 1269 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", 1270 __builtin_return_address(0)); 1271 1272 ip_select_fb_ident(iph); 1273 } 1274 EXPORT_SYMBOL(__ip_select_ident); 1275 1276 static void rt_del(unsigned hash, struct rtable *rt) 1277 { 1278 struct rtable __rcu **rthp; 1279 struct rtable *aux; 1280 1281 rthp = &rt_hash_table[hash].chain; 1282 spin_lock_bh(rt_hash_lock_addr(hash)); 1283 ip_rt_put(rt); 1284 while ((aux = rcu_dereference_protected(*rthp, 1285 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) { 1286 if (aux == rt || rt_is_expired(aux)) { 1287 *rthp = aux->dst.rt_next; 1288 rt_free(aux); 1289 continue; 1290 } 1291 rthp = &aux->dst.rt_next; 1292 } 1293 spin_unlock_bh(rt_hash_lock_addr(hash)); 1294 } 1295 1296 /* called in rcu_read_lock() section */ 1297 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 1298 __be32 saddr, struct net_device *dev) 1299 { 1300 struct in_device *in_dev = __in_dev_get_rcu(dev); 1301 struct inet_peer *peer; 1302 struct net *net; 1303 1304 if (!in_dev) 1305 return; 1306 1307 net = dev_net(dev); 1308 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) || 1309 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) || 1310 ipv4_is_zeronet(new_gw)) 1311 goto reject_redirect; 1312 1313 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 1314 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 1315 goto reject_redirect; 1316 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 1317 goto reject_redirect; 1318 } else { 1319 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 1320 goto reject_redirect; 1321 } 1322 1323 peer = inet_getpeer_v4(daddr, 1); 1324 if (peer) { 1325 peer->redirect_learned.a4 = new_gw; 1326 1327 inet_putpeer(peer); 1328 1329 atomic_inc(&__rt_peer_genid); 1330 } 1331 return; 1332 1333 reject_redirect: 1334 #ifdef CONFIG_IP_ROUTE_VERBOSE 1335 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 1336 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n" 1337 " Advised path = %pI4 -> %pI4\n", 1338 &old_gw, dev->name, &new_gw, 1339 &saddr, &daddr); 1340 #endif 1341 ; 1342 } 1343 1344 static bool peer_pmtu_expired(struct inet_peer *peer) 1345 { 1346 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); 1347 1348 return orig && 1349 time_after_eq(jiffies, orig) && 1350 cmpxchg(&peer->pmtu_expires, orig, 0) == orig; 1351 } 1352 1353 static bool peer_pmtu_cleaned(struct inet_peer *peer) 1354 { 1355 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires); 1356 1357 return orig && 1358 cmpxchg(&peer->pmtu_expires, orig, 0) == orig; 1359 } 1360 1361 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 1362 { 1363 struct rtable *rt = (struct rtable *)dst; 1364 struct dst_entry *ret = dst; 1365 1366 if (rt) { 1367 if (dst->obsolete > 0) { 1368 ip_rt_put(rt); 1369 ret = NULL; 1370 } else if (rt->rt_flags & RTCF_REDIRECTED) { 1371 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src, 1372 rt->rt_oif, 1373 rt_genid(dev_net(dst->dev))); 1374 rt_del(hash, rt); 1375 ret = NULL; 1376 } else if (rt->peer && peer_pmtu_expired(rt->peer)) { 1377 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig); 1378 } 1379 } 1380 return ret; 1381 } 1382 1383 /* 1384 * Algorithm: 1385 * 1. The first ip_rt_redirect_number redirects are sent 1386 * with exponential backoff, then we stop sending them at all, 1387 * assuming that the host ignores our redirects. 1388 * 2. If we did not see packets requiring redirects 1389 * during ip_rt_redirect_silence, we assume that the host 1390 * forgot redirected route and start to send redirects again. 1391 * 1392 * This algorithm is much cheaper and more intelligent than dumb load limiting 1393 * in icmp.c. 1394 * 1395 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 1396 * and "frag. need" (breaks PMTU discovery) in icmp.c. 1397 */ 1398 1399 void ip_rt_send_redirect(struct sk_buff *skb) 1400 { 1401 struct rtable *rt = skb_rtable(skb); 1402 struct in_device *in_dev; 1403 struct inet_peer *peer; 1404 int log_martians; 1405 1406 rcu_read_lock(); 1407 in_dev = __in_dev_get_rcu(rt->dst.dev); 1408 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 1409 rcu_read_unlock(); 1410 return; 1411 } 1412 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 1413 rcu_read_unlock(); 1414 1415 if (!rt->peer) 1416 rt_bind_peer(rt, rt->rt_dst, 1); 1417 peer = rt->peer; 1418 if (!peer) { 1419 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1420 return; 1421 } 1422 1423 /* No redirected packets during ip_rt_redirect_silence; 1424 * reset the algorithm. 1425 */ 1426 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) 1427 peer->rate_tokens = 0; 1428 1429 /* Too many ignored redirects; do not send anything 1430 * set dst.rate_last to the last seen redirected packet. 1431 */ 1432 if (peer->rate_tokens >= ip_rt_redirect_number) { 1433 peer->rate_last = jiffies; 1434 return; 1435 } 1436 1437 /* Check for load limit; set rate_last to the latest sent 1438 * redirect. 1439 */ 1440 if (peer->rate_tokens == 0 || 1441 time_after(jiffies, 1442 (peer->rate_last + 1443 (ip_rt_redirect_load << peer->rate_tokens)))) { 1444 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1445 peer->rate_last = jiffies; 1446 ++peer->rate_tokens; 1447 #ifdef CONFIG_IP_ROUTE_VERBOSE 1448 if (log_martians && 1449 peer->rate_tokens == ip_rt_redirect_number && 1450 net_ratelimit()) 1451 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", 1452 &ip_hdr(skb)->saddr, rt->rt_iif, 1453 &rt->rt_dst, &rt->rt_gateway); 1454 #endif 1455 } 1456 } 1457 1458 static int ip_error(struct sk_buff *skb) 1459 { 1460 struct rtable *rt = skb_rtable(skb); 1461 struct inet_peer *peer; 1462 unsigned long now; 1463 bool send; 1464 int code; 1465 1466 switch (rt->dst.error) { 1467 case EINVAL: 1468 default: 1469 goto out; 1470 case EHOSTUNREACH: 1471 code = ICMP_HOST_UNREACH; 1472 break; 1473 case ENETUNREACH: 1474 code = ICMP_NET_UNREACH; 1475 IP_INC_STATS_BH(dev_net(rt->dst.dev), 1476 IPSTATS_MIB_INNOROUTES); 1477 break; 1478 case EACCES: 1479 code = ICMP_PKT_FILTERED; 1480 break; 1481 } 1482 1483 if (!rt->peer) 1484 rt_bind_peer(rt, rt->rt_dst, 1); 1485 peer = rt->peer; 1486 1487 send = true; 1488 if (peer) { 1489 now = jiffies; 1490 peer->rate_tokens += now - peer->rate_last; 1491 if (peer->rate_tokens > ip_rt_error_burst) 1492 peer->rate_tokens = ip_rt_error_burst; 1493 peer->rate_last = now; 1494 if (peer->rate_tokens >= ip_rt_error_cost) 1495 peer->rate_tokens -= ip_rt_error_cost; 1496 else 1497 send = false; 1498 } 1499 if (send) 1500 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1501 1502 out: kfree_skb(skb); 1503 return 0; 1504 } 1505 1506 /* 1507 * The last two values are not from the RFC but 1508 * are needed for AMPRnet AX.25 paths. 1509 */ 1510 1511 static const unsigned short mtu_plateau[] = 1512 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 }; 1513 1514 static inline unsigned short guess_mtu(unsigned short old_mtu) 1515 { 1516 int i; 1517 1518 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++) 1519 if (old_mtu > mtu_plateau[i]) 1520 return mtu_plateau[i]; 1521 return 68; 1522 } 1523 1524 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, 1525 unsigned short new_mtu, 1526 struct net_device *dev) 1527 { 1528 unsigned short old_mtu = ntohs(iph->tot_len); 1529 unsigned short est_mtu = 0; 1530 struct inet_peer *peer; 1531 1532 peer = inet_getpeer_v4(iph->daddr, 1); 1533 if (peer) { 1534 unsigned short mtu = new_mtu; 1535 1536 if (new_mtu < 68 || new_mtu >= old_mtu) { 1537 /* BSD 4.2 derived systems incorrectly adjust 1538 * tot_len by the IP header length, and report 1539 * a zero MTU in the ICMP message. 1540 */ 1541 if (mtu == 0 && 1542 old_mtu >= 68 + (iph->ihl << 2)) 1543 old_mtu -= iph->ihl << 2; 1544 mtu = guess_mtu(old_mtu); 1545 } 1546 1547 if (mtu < ip_rt_min_pmtu) 1548 mtu = ip_rt_min_pmtu; 1549 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) { 1550 unsigned long pmtu_expires; 1551 1552 pmtu_expires = jiffies + ip_rt_mtu_expires; 1553 if (!pmtu_expires) 1554 pmtu_expires = 1UL; 1555 1556 est_mtu = mtu; 1557 peer->pmtu_learned = mtu; 1558 peer->pmtu_expires = pmtu_expires; 1559 } 1560 1561 inet_putpeer(peer); 1562 1563 atomic_inc(&__rt_peer_genid); 1564 } 1565 return est_mtu ? : new_mtu; 1566 } 1567 1568 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer) 1569 { 1570 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires); 1571 1572 if (!expires) 1573 return; 1574 if (time_before(jiffies, expires)) { 1575 u32 orig_dst_mtu = dst_mtu(dst); 1576 if (peer->pmtu_learned < orig_dst_mtu) { 1577 if (!peer->pmtu_orig) 1578 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU); 1579 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned); 1580 } 1581 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires) 1582 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig); 1583 } 1584 1585 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 1586 { 1587 struct rtable *rt = (struct rtable *) dst; 1588 struct inet_peer *peer; 1589 1590 dst_confirm(dst); 1591 1592 if (!rt->peer) 1593 rt_bind_peer(rt, rt->rt_dst, 1); 1594 peer = rt->peer; 1595 if (peer) { 1596 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires); 1597 1598 if (mtu < ip_rt_min_pmtu) 1599 mtu = ip_rt_min_pmtu; 1600 if (!pmtu_expires || mtu < peer->pmtu_learned) { 1601 1602 pmtu_expires = jiffies + ip_rt_mtu_expires; 1603 if (!pmtu_expires) 1604 pmtu_expires = 1UL; 1605 1606 peer->pmtu_learned = mtu; 1607 peer->pmtu_expires = pmtu_expires; 1608 1609 atomic_inc(&__rt_peer_genid); 1610 rt->rt_peer_genid = rt_peer_genid(); 1611 } 1612 check_peer_pmtu(dst, peer); 1613 } 1614 } 1615 1616 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer) 1617 { 1618 struct rtable *rt = (struct rtable *) dst; 1619 __be32 orig_gw = rt->rt_gateway; 1620 1621 dst_confirm(&rt->dst); 1622 1623 neigh_release(rt->dst.neighbour); 1624 rt->dst.neighbour = NULL; 1625 1626 rt->rt_gateway = peer->redirect_learned.a4; 1627 if (rt_bind_neighbour(rt) || 1628 !(rt->dst.neighbour->nud_state & NUD_VALID)) { 1629 if (rt->dst.neighbour) 1630 neigh_event_send(rt->dst.neighbour, NULL); 1631 rt->rt_gateway = orig_gw; 1632 return -EAGAIN; 1633 } else { 1634 rt->rt_flags |= RTCF_REDIRECTED; 1635 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, 1636 rt->dst.neighbour); 1637 } 1638 return 0; 1639 } 1640 1641 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1642 { 1643 struct rtable *rt = (struct rtable *) dst; 1644 1645 if (rt_is_expired(rt)) 1646 return NULL; 1647 if (rt->rt_peer_genid != rt_peer_genid()) { 1648 struct inet_peer *peer; 1649 1650 if (!rt->peer) 1651 rt_bind_peer(rt, rt->rt_dst, 0); 1652 1653 peer = rt->peer; 1654 if (peer) { 1655 check_peer_pmtu(dst, peer); 1656 1657 if (peer->redirect_learned.a4 && 1658 peer->redirect_learned.a4 != rt->rt_gateway) { 1659 if (check_peer_redir(dst, peer)) 1660 return NULL; 1661 } 1662 } 1663 1664 rt->rt_peer_genid = rt_peer_genid(); 1665 } 1666 return dst; 1667 } 1668 1669 static void ipv4_dst_destroy(struct dst_entry *dst) 1670 { 1671 struct rtable *rt = (struct rtable *) dst; 1672 struct inet_peer *peer = rt->peer; 1673 1674 if (rt->fi) { 1675 fib_info_put(rt->fi); 1676 rt->fi = NULL; 1677 } 1678 if (peer) { 1679 rt->peer = NULL; 1680 inet_putpeer(peer); 1681 } 1682 } 1683 1684 1685 static void ipv4_link_failure(struct sk_buff *skb) 1686 { 1687 struct rtable *rt; 1688 1689 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1690 1691 rt = skb_rtable(skb); 1692 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer)) 1693 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig); 1694 } 1695 1696 static int ip_rt_bug(struct sk_buff *skb) 1697 { 1698 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n", 1699 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1700 skb->dev ? skb->dev->name : "?"); 1701 kfree_skb(skb); 1702 WARN_ON(1); 1703 return 0; 1704 } 1705 1706 /* 1707 We do not cache source address of outgoing interface, 1708 because it is used only by IP RR, TS and SRR options, 1709 so that it out of fast path. 1710 1711 BTW remember: "addr" is allowed to be not aligned 1712 in IP options! 1713 */ 1714 1715 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt) 1716 { 1717 __be32 src; 1718 1719 if (rt_is_output_route(rt)) 1720 src = ip_hdr(skb)->saddr; 1721 else { 1722 struct fib_result res; 1723 struct flowi4 fl4; 1724 struct iphdr *iph; 1725 1726 iph = ip_hdr(skb); 1727 1728 memset(&fl4, 0, sizeof(fl4)); 1729 fl4.daddr = iph->daddr; 1730 fl4.saddr = iph->saddr; 1731 fl4.flowi4_tos = iph->tos; 1732 fl4.flowi4_oif = rt->dst.dev->ifindex; 1733 fl4.flowi4_iif = skb->dev->ifindex; 1734 fl4.flowi4_mark = skb->mark; 1735 1736 rcu_read_lock(); 1737 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0) 1738 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res); 1739 else 1740 src = inet_select_addr(rt->dst.dev, rt->rt_gateway, 1741 RT_SCOPE_UNIVERSE); 1742 rcu_read_unlock(); 1743 } 1744 memcpy(addr, &src, 4); 1745 } 1746 1747 #ifdef CONFIG_IP_ROUTE_CLASSID 1748 static void set_class_tag(struct rtable *rt, u32 tag) 1749 { 1750 if (!(rt->dst.tclassid & 0xFFFF)) 1751 rt->dst.tclassid |= tag & 0xFFFF; 1752 if (!(rt->dst.tclassid & 0xFFFF0000)) 1753 rt->dst.tclassid |= tag & 0xFFFF0000; 1754 } 1755 #endif 1756 1757 static unsigned int ipv4_default_advmss(const struct dst_entry *dst) 1758 { 1759 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS); 1760 1761 if (advmss == 0) { 1762 advmss = max_t(unsigned int, dst->dev->mtu - 40, 1763 ip_rt_min_advmss); 1764 if (advmss > 65535 - 40) 1765 advmss = 65535 - 40; 1766 } 1767 return advmss; 1768 } 1769 1770 static unsigned int ipv4_default_mtu(const struct dst_entry *dst) 1771 { 1772 unsigned int mtu = dst->dev->mtu; 1773 1774 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) { 1775 const struct rtable *rt = (const struct rtable *) dst; 1776 1777 if (rt->rt_gateway != rt->rt_dst && mtu > 576) 1778 mtu = 576; 1779 } 1780 1781 if (mtu > IP_MAX_MTU) 1782 mtu = IP_MAX_MTU; 1783 1784 return mtu; 1785 } 1786 1787 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4, 1788 struct fib_info *fi) 1789 { 1790 struct inet_peer *peer; 1791 int create = 0; 1792 1793 /* If a peer entry exists for this destination, we must hook 1794 * it up in order to get at cached metrics. 1795 */ 1796 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS)) 1797 create = 1; 1798 1799 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create); 1800 if (peer) { 1801 rt->rt_peer_genid = rt_peer_genid(); 1802 if (inet_metrics_new(peer)) 1803 memcpy(peer->metrics, fi->fib_metrics, 1804 sizeof(u32) * RTAX_MAX); 1805 dst_init_metrics(&rt->dst, peer->metrics, false); 1806 1807 check_peer_pmtu(&rt->dst, peer); 1808 if (peer->redirect_learned.a4 && 1809 peer->redirect_learned.a4 != rt->rt_gateway) { 1810 rt->rt_gateway = peer->redirect_learned.a4; 1811 rt->rt_flags |= RTCF_REDIRECTED; 1812 } 1813 } else { 1814 if (fi->fib_metrics != (u32 *) dst_default_metrics) { 1815 rt->fi = fi; 1816 atomic_inc(&fi->fib_clntref); 1817 } 1818 dst_init_metrics(&rt->dst, fi->fib_metrics, true); 1819 } 1820 } 1821 1822 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4, 1823 const struct fib_result *res, 1824 struct fib_info *fi, u16 type, u32 itag) 1825 { 1826 struct dst_entry *dst = &rt->dst; 1827 1828 if (fi) { 1829 if (FIB_RES_GW(*res) && 1830 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 1831 rt->rt_gateway = FIB_RES_GW(*res); 1832 rt_init_metrics(rt, fl4, fi); 1833 #ifdef CONFIG_IP_ROUTE_CLASSID 1834 dst->tclassid = FIB_RES_NH(*res).nh_tclassid; 1835 #endif 1836 } 1837 1838 if (dst_mtu(dst) > IP_MAX_MTU) 1839 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU); 1840 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40) 1841 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40); 1842 1843 #ifdef CONFIG_IP_ROUTE_CLASSID 1844 #ifdef CONFIG_IP_MULTIPLE_TABLES 1845 set_class_tag(rt, fib_rules_tclass(res)); 1846 #endif 1847 set_class_tag(rt, itag); 1848 #endif 1849 } 1850 1851 static struct rtable *rt_dst_alloc(struct net_device *dev, 1852 bool nopolicy, bool noxfrm) 1853 { 1854 return dst_alloc(&ipv4_dst_ops, dev, 1, -1, 1855 DST_HOST | 1856 (nopolicy ? DST_NOPOLICY : 0) | 1857 (noxfrm ? DST_NOXFRM : 0)); 1858 } 1859 1860 /* called in rcu_read_lock() section */ 1861 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1862 u8 tos, struct net_device *dev, int our) 1863 { 1864 unsigned int hash; 1865 struct rtable *rth; 1866 __be32 spec_dst; 1867 struct in_device *in_dev = __in_dev_get_rcu(dev); 1868 u32 itag = 0; 1869 int err; 1870 1871 /* Primary sanity checks. */ 1872 1873 if (in_dev == NULL) 1874 return -EINVAL; 1875 1876 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1877 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP)) 1878 goto e_inval; 1879 1880 if (ipv4_is_zeronet(saddr)) { 1881 if (!ipv4_is_local_multicast(daddr)) 1882 goto e_inval; 1883 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 1884 } else { 1885 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 1886 &itag); 1887 if (err < 0) 1888 goto e_err; 1889 } 1890 rth = rt_dst_alloc(init_net.loopback_dev, 1891 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 1892 if (!rth) 1893 goto e_nobufs; 1894 1895 #ifdef CONFIG_IP_ROUTE_CLASSID 1896 rth->dst.tclassid = itag; 1897 #endif 1898 rth->dst.output = ip_rt_bug; 1899 1900 rth->rt_key_dst = daddr; 1901 rth->rt_key_src = saddr; 1902 rth->rt_genid = rt_genid(dev_net(dev)); 1903 rth->rt_flags = RTCF_MULTICAST; 1904 rth->rt_type = RTN_MULTICAST; 1905 rth->rt_key_tos = tos; 1906 rth->rt_dst = daddr; 1907 rth->rt_src = saddr; 1908 rth->rt_route_iif = dev->ifindex; 1909 rth->rt_iif = dev->ifindex; 1910 rth->rt_oif = 0; 1911 rth->rt_mark = skb->mark; 1912 rth->rt_gateway = daddr; 1913 rth->rt_spec_dst= spec_dst; 1914 rth->rt_peer_genid = 0; 1915 rth->peer = NULL; 1916 rth->fi = NULL; 1917 if (our) { 1918 rth->dst.input= ip_local_deliver; 1919 rth->rt_flags |= RTCF_LOCAL; 1920 } 1921 1922 #ifdef CONFIG_IP_MROUTE 1923 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1924 rth->dst.input = ip_mr_input; 1925 #endif 1926 RT_CACHE_STAT_INC(in_slow_mc); 1927 1928 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); 1929 rth = rt_intern_hash(hash, rth, skb, dev->ifindex); 1930 return IS_ERR(rth) ? PTR_ERR(rth) : 0; 1931 1932 e_nobufs: 1933 return -ENOBUFS; 1934 e_inval: 1935 return -EINVAL; 1936 e_err: 1937 return err; 1938 } 1939 1940 1941 static void ip_handle_martian_source(struct net_device *dev, 1942 struct in_device *in_dev, 1943 struct sk_buff *skb, 1944 __be32 daddr, 1945 __be32 saddr) 1946 { 1947 RT_CACHE_STAT_INC(in_martian_src); 1948 #ifdef CONFIG_IP_ROUTE_VERBOSE 1949 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1950 /* 1951 * RFC1812 recommendation, if source is martian, 1952 * the only hint is MAC header. 1953 */ 1954 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n", 1955 &daddr, &saddr, dev->name); 1956 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1957 int i; 1958 const unsigned char *p = skb_mac_header(skb); 1959 printk(KERN_WARNING "ll header: "); 1960 for (i = 0; i < dev->hard_header_len; i++, p++) { 1961 printk("%02x", *p); 1962 if (i < (dev->hard_header_len - 1)) 1963 printk(":"); 1964 } 1965 printk("\n"); 1966 } 1967 } 1968 #endif 1969 } 1970 1971 /* called in rcu_read_lock() section */ 1972 static int __mkroute_input(struct sk_buff *skb, 1973 const struct fib_result *res, 1974 struct in_device *in_dev, 1975 __be32 daddr, __be32 saddr, u32 tos, 1976 struct rtable **result) 1977 { 1978 struct rtable *rth; 1979 int err; 1980 struct in_device *out_dev; 1981 unsigned int flags = 0; 1982 __be32 spec_dst; 1983 u32 itag; 1984 1985 /* get a working reference to the output device */ 1986 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); 1987 if (out_dev == NULL) { 1988 if (net_ratelimit()) 1989 printk(KERN_CRIT "Bug in ip_route_input" \ 1990 "_slow(). Please, report\n"); 1991 return -EINVAL; 1992 } 1993 1994 1995 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res), 1996 in_dev->dev, &spec_dst, &itag); 1997 if (err < 0) { 1998 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1999 saddr); 2000 2001 goto cleanup; 2002 } 2003 2004 if (err) 2005 flags |= RTCF_DIRECTSRC; 2006 2007 if (out_dev == in_dev && err && 2008 (IN_DEV_SHARED_MEDIA(out_dev) || 2009 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 2010 flags |= RTCF_DOREDIRECT; 2011 2012 if (skb->protocol != htons(ETH_P_IP)) { 2013 /* Not IP (i.e. ARP). Do not create route, if it is 2014 * invalid for proxy arp. DNAT routes are always valid. 2015 * 2016 * Proxy arp feature have been extended to allow, ARP 2017 * replies back to the same interface, to support 2018 * Private VLAN switch technologies. See arp.c. 2019 */ 2020 if (out_dev == in_dev && 2021 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 2022 err = -EINVAL; 2023 goto cleanup; 2024 } 2025 } 2026 2027 rth = rt_dst_alloc(out_dev->dev, 2028 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2029 IN_DEV_CONF_GET(out_dev, NOXFRM)); 2030 if (!rth) { 2031 err = -ENOBUFS; 2032 goto cleanup; 2033 } 2034 2035 rth->rt_key_dst = daddr; 2036 rth->rt_key_src = saddr; 2037 rth->rt_genid = rt_genid(dev_net(rth->dst.dev)); 2038 rth->rt_flags = flags; 2039 rth->rt_type = res->type; 2040 rth->rt_key_tos = tos; 2041 rth->rt_dst = daddr; 2042 rth->rt_src = saddr; 2043 rth->rt_route_iif = in_dev->dev->ifindex; 2044 rth->rt_iif = in_dev->dev->ifindex; 2045 rth->rt_oif = 0; 2046 rth->rt_mark = skb->mark; 2047 rth->rt_gateway = daddr; 2048 rth->rt_spec_dst= spec_dst; 2049 rth->rt_peer_genid = 0; 2050 rth->peer = NULL; 2051 rth->fi = NULL; 2052 2053 rth->dst.input = ip_forward; 2054 rth->dst.output = ip_output; 2055 2056 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag); 2057 2058 *result = rth; 2059 err = 0; 2060 cleanup: 2061 return err; 2062 } 2063 2064 static int ip_mkroute_input(struct sk_buff *skb, 2065 struct fib_result *res, 2066 const struct flowi4 *fl4, 2067 struct in_device *in_dev, 2068 __be32 daddr, __be32 saddr, u32 tos) 2069 { 2070 struct rtable* rth = NULL; 2071 int err; 2072 unsigned hash; 2073 2074 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2075 if (res->fi && res->fi->fib_nhs > 1) 2076 fib_select_multipath(res); 2077 #endif 2078 2079 /* create a routing cache entry */ 2080 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); 2081 if (err) 2082 return err; 2083 2084 /* put it into the cache */ 2085 hash = rt_hash(daddr, saddr, fl4->flowi4_iif, 2086 rt_genid(dev_net(rth->dst.dev))); 2087 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif); 2088 if (IS_ERR(rth)) 2089 return PTR_ERR(rth); 2090 return 0; 2091 } 2092 2093 /* 2094 * NOTE. We drop all the packets that has local source 2095 * addresses, because every properly looped back packet 2096 * must have correct destination already attached by output routine. 2097 * 2098 * Such approach solves two big problems: 2099 * 1. Not simplex devices are handled properly. 2100 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2101 * called with rcu_read_lock() 2102 */ 2103 2104 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2105 u8 tos, struct net_device *dev) 2106 { 2107 struct fib_result res; 2108 struct in_device *in_dev = __in_dev_get_rcu(dev); 2109 struct flowi4 fl4; 2110 unsigned flags = 0; 2111 u32 itag = 0; 2112 struct rtable * rth; 2113 unsigned hash; 2114 __be32 spec_dst; 2115 int err = -EINVAL; 2116 struct net * net = dev_net(dev); 2117 2118 /* IP on this device is disabled. */ 2119 2120 if (!in_dev) 2121 goto out; 2122 2123 /* Check for the most weird martians, which can be not detected 2124 by fib_lookup. 2125 */ 2126 2127 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 2128 ipv4_is_loopback(saddr)) 2129 goto martian_source; 2130 2131 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) 2132 goto brd_input; 2133 2134 /* Accept zero addresses only to limited broadcast; 2135 * I even do not know to fix it or not. Waiting for complains :-) 2136 */ 2137 if (ipv4_is_zeronet(saddr)) 2138 goto martian_source; 2139 2140 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr)) 2141 goto martian_destination; 2142 2143 /* 2144 * Now we are ready to route packet. 2145 */ 2146 fl4.flowi4_oif = 0; 2147 fl4.flowi4_iif = dev->ifindex; 2148 fl4.flowi4_mark = skb->mark; 2149 fl4.flowi4_tos = tos; 2150 fl4.flowi4_scope = RT_SCOPE_UNIVERSE; 2151 fl4.daddr = daddr; 2152 fl4.saddr = saddr; 2153 err = fib_lookup(net, &fl4, &res); 2154 if (err != 0) { 2155 if (!IN_DEV_FORWARD(in_dev)) 2156 goto e_hostunreach; 2157 goto no_route; 2158 } 2159 2160 RT_CACHE_STAT_INC(in_slow_tot); 2161 2162 if (res.type == RTN_BROADCAST) 2163 goto brd_input; 2164 2165 if (res.type == RTN_LOCAL) { 2166 err = fib_validate_source(skb, saddr, daddr, tos, 2167 net->loopback_dev->ifindex, 2168 dev, &spec_dst, &itag); 2169 if (err < 0) 2170 goto martian_source_keep_err; 2171 if (err) 2172 flags |= RTCF_DIRECTSRC; 2173 spec_dst = daddr; 2174 goto local_input; 2175 } 2176 2177 if (!IN_DEV_FORWARD(in_dev)) 2178 goto e_hostunreach; 2179 if (res.type != RTN_UNICAST) 2180 goto martian_destination; 2181 2182 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos); 2183 out: return err; 2184 2185 brd_input: 2186 if (skb->protocol != htons(ETH_P_IP)) 2187 goto e_inval; 2188 2189 if (ipv4_is_zeronet(saddr)) 2190 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 2191 else { 2192 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst, 2193 &itag); 2194 if (err < 0) 2195 goto martian_source_keep_err; 2196 if (err) 2197 flags |= RTCF_DIRECTSRC; 2198 } 2199 flags |= RTCF_BROADCAST; 2200 res.type = RTN_BROADCAST; 2201 RT_CACHE_STAT_INC(in_brd); 2202 2203 local_input: 2204 rth = rt_dst_alloc(net->loopback_dev, 2205 IN_DEV_CONF_GET(in_dev, NOPOLICY), false); 2206 if (!rth) 2207 goto e_nobufs; 2208 2209 rth->dst.input= ip_local_deliver; 2210 rth->dst.output= ip_rt_bug; 2211 #ifdef CONFIG_IP_ROUTE_CLASSID 2212 rth->dst.tclassid = itag; 2213 #endif 2214 2215 rth->rt_key_dst = daddr; 2216 rth->rt_key_src = saddr; 2217 rth->rt_genid = rt_genid(net); 2218 rth->rt_flags = flags|RTCF_LOCAL; 2219 rth->rt_type = res.type; 2220 rth->rt_key_tos = tos; 2221 rth->rt_dst = daddr; 2222 rth->rt_src = saddr; 2223 #ifdef CONFIG_IP_ROUTE_CLASSID 2224 rth->dst.tclassid = itag; 2225 #endif 2226 rth->rt_route_iif = dev->ifindex; 2227 rth->rt_iif = dev->ifindex; 2228 rth->rt_oif = 0; 2229 rth->rt_mark = skb->mark; 2230 rth->rt_gateway = daddr; 2231 rth->rt_spec_dst= spec_dst; 2232 rth->rt_peer_genid = 0; 2233 rth->peer = NULL; 2234 rth->fi = NULL; 2235 if (res.type == RTN_UNREACHABLE) { 2236 rth->dst.input= ip_error; 2237 rth->dst.error= -err; 2238 rth->rt_flags &= ~RTCF_LOCAL; 2239 } 2240 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net)); 2241 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif); 2242 err = 0; 2243 if (IS_ERR(rth)) 2244 err = PTR_ERR(rth); 2245 goto out; 2246 2247 no_route: 2248 RT_CACHE_STAT_INC(in_no_route); 2249 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 2250 res.type = RTN_UNREACHABLE; 2251 if (err == -ESRCH) 2252 err = -ENETUNREACH; 2253 goto local_input; 2254 2255 /* 2256 * Do not cache martian addresses: they should be logged (RFC1812) 2257 */ 2258 martian_destination: 2259 RT_CACHE_STAT_INC(in_martian_dst); 2260 #ifdef CONFIG_IP_ROUTE_VERBOSE 2261 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 2262 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n", 2263 &daddr, &saddr, dev->name); 2264 #endif 2265 2266 e_hostunreach: 2267 err = -EHOSTUNREACH; 2268 goto out; 2269 2270 e_inval: 2271 err = -EINVAL; 2272 goto out; 2273 2274 e_nobufs: 2275 err = -ENOBUFS; 2276 goto out; 2277 2278 martian_source: 2279 err = -EINVAL; 2280 martian_source_keep_err: 2281 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2282 goto out; 2283 } 2284 2285 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2286 u8 tos, struct net_device *dev, bool noref) 2287 { 2288 struct rtable * rth; 2289 unsigned hash; 2290 int iif = dev->ifindex; 2291 struct net *net; 2292 int res; 2293 2294 net = dev_net(dev); 2295 2296 rcu_read_lock(); 2297 2298 if (!rt_caching(net)) 2299 goto skip_cache; 2300 2301 tos &= IPTOS_RT_MASK; 2302 hash = rt_hash(daddr, saddr, iif, rt_genid(net)); 2303 2304 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 2305 rth = rcu_dereference(rth->dst.rt_next)) { 2306 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) | 2307 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) | 2308 (rth->rt_iif ^ iif) | 2309 rth->rt_oif | 2310 (rth->rt_key_tos ^ tos)) == 0 && 2311 rth->rt_mark == skb->mark && 2312 net_eq(dev_net(rth->dst.dev), net) && 2313 !rt_is_expired(rth)) { 2314 if (noref) { 2315 dst_use_noref(&rth->dst, jiffies); 2316 skb_dst_set_noref(skb, &rth->dst); 2317 } else { 2318 dst_use(&rth->dst, jiffies); 2319 skb_dst_set(skb, &rth->dst); 2320 } 2321 RT_CACHE_STAT_INC(in_hit); 2322 rcu_read_unlock(); 2323 return 0; 2324 } 2325 RT_CACHE_STAT_INC(in_hlist_search); 2326 } 2327 2328 skip_cache: 2329 /* Multicast recognition logic is moved from route cache to here. 2330 The problem was that too many Ethernet cards have broken/missing 2331 hardware multicast filters :-( As result the host on multicasting 2332 network acquires a lot of useless route cache entries, sort of 2333 SDR messages from all the world. Now we try to get rid of them. 2334 Really, provided software IP multicast filter is organized 2335 reasonably (at least, hashed), it does not result in a slowdown 2336 comparing with route cache reject entries. 2337 Note, that multicast routers are not affected, because 2338 route cache entry is created eventually. 2339 */ 2340 if (ipv4_is_multicast(daddr)) { 2341 struct in_device *in_dev = __in_dev_get_rcu(dev); 2342 2343 if (in_dev) { 2344 int our = ip_check_mc_rcu(in_dev, daddr, saddr, 2345 ip_hdr(skb)->protocol); 2346 if (our 2347 #ifdef CONFIG_IP_MROUTE 2348 || 2349 (!ipv4_is_local_multicast(daddr) && 2350 IN_DEV_MFORWARD(in_dev)) 2351 #endif 2352 ) { 2353 int res = ip_route_input_mc(skb, daddr, saddr, 2354 tos, dev, our); 2355 rcu_read_unlock(); 2356 return res; 2357 } 2358 } 2359 rcu_read_unlock(); 2360 return -EINVAL; 2361 } 2362 res = ip_route_input_slow(skb, daddr, saddr, tos, dev); 2363 rcu_read_unlock(); 2364 return res; 2365 } 2366 EXPORT_SYMBOL(ip_route_input_common); 2367 2368 /* called with rcu_read_lock() */ 2369 static struct rtable *__mkroute_output(const struct fib_result *res, 2370 const struct flowi4 *fl4, 2371 __be32 orig_daddr, __be32 orig_saddr, 2372 int orig_oif, struct net_device *dev_out, 2373 unsigned int flags) 2374 { 2375 struct fib_info *fi = res->fi; 2376 u32 tos = RT_FL_TOS(fl4); 2377 struct in_device *in_dev; 2378 u16 type = res->type; 2379 struct rtable *rth; 2380 2381 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK)) 2382 return ERR_PTR(-EINVAL); 2383 2384 if (ipv4_is_lbcast(fl4->daddr)) 2385 type = RTN_BROADCAST; 2386 else if (ipv4_is_multicast(fl4->daddr)) 2387 type = RTN_MULTICAST; 2388 else if (ipv4_is_zeronet(fl4->daddr)) 2389 return ERR_PTR(-EINVAL); 2390 2391 if (dev_out->flags & IFF_LOOPBACK) 2392 flags |= RTCF_LOCAL; 2393 2394 in_dev = __in_dev_get_rcu(dev_out); 2395 if (!in_dev) 2396 return ERR_PTR(-EINVAL); 2397 2398 if (type == RTN_BROADCAST) { 2399 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2400 fi = NULL; 2401 } else if (type == RTN_MULTICAST) { 2402 flags |= RTCF_MULTICAST | RTCF_LOCAL; 2403 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr, 2404 fl4->flowi4_proto)) 2405 flags &= ~RTCF_LOCAL; 2406 /* If multicast route do not exist use 2407 * default one, but do not gateway in this case. 2408 * Yes, it is hack. 2409 */ 2410 if (fi && res->prefixlen < 4) 2411 fi = NULL; 2412 } 2413 2414 rth = rt_dst_alloc(dev_out, 2415 IN_DEV_CONF_GET(in_dev, NOPOLICY), 2416 IN_DEV_CONF_GET(in_dev, NOXFRM)); 2417 if (!rth) 2418 return ERR_PTR(-ENOBUFS); 2419 2420 rth->dst.output = ip_output; 2421 2422 rth->rt_key_dst = orig_daddr; 2423 rth->rt_key_src = orig_saddr; 2424 rth->rt_genid = rt_genid(dev_net(dev_out)); 2425 rth->rt_flags = flags; 2426 rth->rt_type = type; 2427 rth->rt_key_tos = tos; 2428 rth->rt_dst = fl4->daddr; 2429 rth->rt_src = fl4->saddr; 2430 rth->rt_route_iif = 0; 2431 rth->rt_iif = orig_oif ? : dev_out->ifindex; 2432 rth->rt_oif = orig_oif; 2433 rth->rt_mark = fl4->flowi4_mark; 2434 rth->rt_gateway = fl4->daddr; 2435 rth->rt_spec_dst= fl4->saddr; 2436 rth->rt_peer_genid = 0; 2437 rth->peer = NULL; 2438 rth->fi = NULL; 2439 2440 RT_CACHE_STAT_INC(out_slow_tot); 2441 2442 if (flags & RTCF_LOCAL) { 2443 rth->dst.input = ip_local_deliver; 2444 rth->rt_spec_dst = fl4->daddr; 2445 } 2446 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2447 rth->rt_spec_dst = fl4->saddr; 2448 if (flags & RTCF_LOCAL && 2449 !(dev_out->flags & IFF_LOOPBACK)) { 2450 rth->dst.output = ip_mc_output; 2451 RT_CACHE_STAT_INC(out_slow_mc); 2452 } 2453 #ifdef CONFIG_IP_MROUTE 2454 if (type == RTN_MULTICAST) { 2455 if (IN_DEV_MFORWARD(in_dev) && 2456 !ipv4_is_local_multicast(fl4->daddr)) { 2457 rth->dst.input = ip_mr_input; 2458 rth->dst.output = ip_mc_output; 2459 } 2460 } 2461 #endif 2462 } 2463 2464 rt_set_nexthop(rth, fl4, res, fi, type, 0); 2465 2466 return rth; 2467 } 2468 2469 /* 2470 * Major route resolver routine. 2471 * called with rcu_read_lock(); 2472 */ 2473 2474 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4) 2475 { 2476 struct net_device *dev_out = NULL; 2477 u32 tos = RT_FL_TOS(fl4); 2478 unsigned int flags = 0; 2479 struct fib_result res; 2480 struct rtable *rth; 2481 __be32 orig_daddr; 2482 __be32 orig_saddr; 2483 int orig_oif; 2484 2485 res.fi = NULL; 2486 #ifdef CONFIG_IP_MULTIPLE_TABLES 2487 res.r = NULL; 2488 #endif 2489 2490 orig_daddr = fl4->daddr; 2491 orig_saddr = fl4->saddr; 2492 orig_oif = fl4->flowi4_oif; 2493 2494 fl4->flowi4_iif = net->loopback_dev->ifindex; 2495 fl4->flowi4_tos = tos & IPTOS_RT_MASK; 2496 fl4->flowi4_scope = ((tos & RTO_ONLINK) ? 2497 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); 2498 2499 rcu_read_lock(); 2500 if (fl4->saddr) { 2501 rth = ERR_PTR(-EINVAL); 2502 if (ipv4_is_multicast(fl4->saddr) || 2503 ipv4_is_lbcast(fl4->saddr) || 2504 ipv4_is_zeronet(fl4->saddr)) 2505 goto out; 2506 2507 /* I removed check for oif == dev_out->oif here. 2508 It was wrong for two reasons: 2509 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2510 is assigned to multiple interfaces. 2511 2. Moreover, we are allowed to send packets with saddr 2512 of another iface. --ANK 2513 */ 2514 2515 if (fl4->flowi4_oif == 0 && 2516 (ipv4_is_multicast(fl4->daddr) || 2517 ipv4_is_lbcast(fl4->daddr))) { 2518 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2519 dev_out = __ip_dev_find(net, fl4->saddr, false); 2520 if (dev_out == NULL) 2521 goto out; 2522 2523 /* Special hack: user can direct multicasts 2524 and limited broadcast via necessary interface 2525 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2526 This hack is not just for fun, it allows 2527 vic,vat and friends to work. 2528 They bind socket to loopback, set ttl to zero 2529 and expect that it will work. 2530 From the viewpoint of routing cache they are broken, 2531 because we are not allowed to build multicast path 2532 with loopback source addr (look, routing cache 2533 cannot know, that ttl is zero, so that packet 2534 will not leave this host and route is valid). 2535 Luckily, this hack is good workaround. 2536 */ 2537 2538 fl4->flowi4_oif = dev_out->ifindex; 2539 goto make_route; 2540 } 2541 2542 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) { 2543 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2544 if (!__ip_dev_find(net, fl4->saddr, false)) 2545 goto out; 2546 } 2547 } 2548 2549 2550 if (fl4->flowi4_oif) { 2551 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif); 2552 rth = ERR_PTR(-ENODEV); 2553 if (dev_out == NULL) 2554 goto out; 2555 2556 /* RACE: Check return value of inet_select_addr instead. */ 2557 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) { 2558 rth = ERR_PTR(-ENETUNREACH); 2559 goto out; 2560 } 2561 if (ipv4_is_local_multicast(fl4->daddr) || 2562 ipv4_is_lbcast(fl4->daddr)) { 2563 if (!fl4->saddr) 2564 fl4->saddr = inet_select_addr(dev_out, 0, 2565 RT_SCOPE_LINK); 2566 goto make_route; 2567 } 2568 if (fl4->saddr) { 2569 if (ipv4_is_multicast(fl4->daddr)) 2570 fl4->saddr = inet_select_addr(dev_out, 0, 2571 fl4->flowi4_scope); 2572 else if (!fl4->daddr) 2573 fl4->saddr = inet_select_addr(dev_out, 0, 2574 RT_SCOPE_HOST); 2575 } 2576 } 2577 2578 if (!fl4->daddr) { 2579 fl4->daddr = fl4->saddr; 2580 if (!fl4->daddr) 2581 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); 2582 dev_out = net->loopback_dev; 2583 fl4->flowi4_oif = net->loopback_dev->ifindex; 2584 res.type = RTN_LOCAL; 2585 flags |= RTCF_LOCAL; 2586 goto make_route; 2587 } 2588 2589 if (fib_lookup(net, fl4, &res)) { 2590 res.fi = NULL; 2591 if (fl4->flowi4_oif) { 2592 /* Apparently, routing tables are wrong. Assume, 2593 that the destination is on link. 2594 2595 WHY? DW. 2596 Because we are allowed to send to iface 2597 even if it has NO routes and NO assigned 2598 addresses. When oif is specified, routing 2599 tables are looked up with only one purpose: 2600 to catch if destination is gatewayed, rather than 2601 direct. Moreover, if MSG_DONTROUTE is set, 2602 we send packet, ignoring both routing tables 2603 and ifaddr state. --ANK 2604 2605 2606 We could make it even if oif is unknown, 2607 likely IPv6, but we do not. 2608 */ 2609 2610 if (fl4->saddr == 0) 2611 fl4->saddr = inet_select_addr(dev_out, 0, 2612 RT_SCOPE_LINK); 2613 res.type = RTN_UNICAST; 2614 goto make_route; 2615 } 2616 rth = ERR_PTR(-ENETUNREACH); 2617 goto out; 2618 } 2619 2620 if (res.type == RTN_LOCAL) { 2621 if (!fl4->saddr) { 2622 if (res.fi->fib_prefsrc) 2623 fl4->saddr = res.fi->fib_prefsrc; 2624 else 2625 fl4->saddr = fl4->daddr; 2626 } 2627 dev_out = net->loopback_dev; 2628 fl4->flowi4_oif = dev_out->ifindex; 2629 res.fi = NULL; 2630 flags |= RTCF_LOCAL; 2631 goto make_route; 2632 } 2633 2634 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2635 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0) 2636 fib_select_multipath(&res); 2637 else 2638 #endif 2639 if (!res.prefixlen && 2640 res.table->tb_num_default > 1 && 2641 res.type == RTN_UNICAST && !fl4->flowi4_oif) 2642 fib_select_default(&res); 2643 2644 if (!fl4->saddr) 2645 fl4->saddr = FIB_RES_PREFSRC(net, res); 2646 2647 dev_out = FIB_RES_DEV(res); 2648 fl4->flowi4_oif = dev_out->ifindex; 2649 2650 2651 make_route: 2652 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif, 2653 dev_out, flags); 2654 if (!IS_ERR(rth)) { 2655 unsigned int hash; 2656 2657 hash = rt_hash(orig_daddr, orig_saddr, orig_oif, 2658 rt_genid(dev_net(dev_out))); 2659 rth = rt_intern_hash(hash, rth, NULL, orig_oif); 2660 } 2661 2662 out: 2663 rcu_read_unlock(); 2664 return rth; 2665 } 2666 2667 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4) 2668 { 2669 struct rtable *rth; 2670 unsigned int hash; 2671 2672 if (!rt_caching(net)) 2673 goto slow_output; 2674 2675 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net)); 2676 2677 rcu_read_lock_bh(); 2678 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth; 2679 rth = rcu_dereference_bh(rth->dst.rt_next)) { 2680 if (rth->rt_key_dst == flp4->daddr && 2681 rth->rt_key_src == flp4->saddr && 2682 rt_is_output_route(rth) && 2683 rth->rt_oif == flp4->flowi4_oif && 2684 rth->rt_mark == flp4->flowi4_mark && 2685 !((rth->rt_key_tos ^ flp4->flowi4_tos) & 2686 (IPTOS_RT_MASK | RTO_ONLINK)) && 2687 net_eq(dev_net(rth->dst.dev), net) && 2688 !rt_is_expired(rth)) { 2689 dst_use(&rth->dst, jiffies); 2690 RT_CACHE_STAT_INC(out_hit); 2691 rcu_read_unlock_bh(); 2692 if (!flp4->saddr) 2693 flp4->saddr = rth->rt_src; 2694 if (!flp4->daddr) 2695 flp4->daddr = rth->rt_dst; 2696 return rth; 2697 } 2698 RT_CACHE_STAT_INC(out_hlist_search); 2699 } 2700 rcu_read_unlock_bh(); 2701 2702 slow_output: 2703 return ip_route_output_slow(net, flp4); 2704 } 2705 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2706 2707 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie) 2708 { 2709 return NULL; 2710 } 2711 2712 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst) 2713 { 2714 return 0; 2715 } 2716 2717 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) 2718 { 2719 } 2720 2721 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, 2722 unsigned long old) 2723 { 2724 return NULL; 2725 } 2726 2727 static struct dst_ops ipv4_dst_blackhole_ops = { 2728 .family = AF_INET, 2729 .protocol = cpu_to_be16(ETH_P_IP), 2730 .destroy = ipv4_dst_destroy, 2731 .check = ipv4_blackhole_dst_check, 2732 .default_mtu = ipv4_blackhole_default_mtu, 2733 .default_advmss = ipv4_default_advmss, 2734 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2735 .cow_metrics = ipv4_rt_blackhole_cow_metrics, 2736 }; 2737 2738 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2739 { 2740 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0); 2741 struct rtable *ort = (struct rtable *) dst_orig; 2742 2743 if (rt) { 2744 struct dst_entry *new = &rt->dst; 2745 2746 new->__use = 1; 2747 new->input = dst_discard; 2748 new->output = dst_discard; 2749 dst_copy_metrics(new, &ort->dst); 2750 2751 new->dev = ort->dst.dev; 2752 if (new->dev) 2753 dev_hold(new->dev); 2754 2755 rt->rt_key_dst = ort->rt_key_dst; 2756 rt->rt_key_src = ort->rt_key_src; 2757 rt->rt_key_tos = ort->rt_key_tos; 2758 rt->rt_route_iif = ort->rt_route_iif; 2759 rt->rt_iif = ort->rt_iif; 2760 rt->rt_oif = ort->rt_oif; 2761 rt->rt_mark = ort->rt_mark; 2762 2763 rt->rt_genid = rt_genid(net); 2764 rt->rt_flags = ort->rt_flags; 2765 rt->rt_type = ort->rt_type; 2766 rt->rt_dst = ort->rt_dst; 2767 rt->rt_src = ort->rt_src; 2768 rt->rt_gateway = ort->rt_gateway; 2769 rt->rt_spec_dst = ort->rt_spec_dst; 2770 rt->peer = ort->peer; 2771 if (rt->peer) 2772 atomic_inc(&rt->peer->refcnt); 2773 rt->fi = ort->fi; 2774 if (rt->fi) 2775 atomic_inc(&rt->fi->fib_clntref); 2776 2777 dst_free(new); 2778 } 2779 2780 dst_release(dst_orig); 2781 2782 return rt ? &rt->dst : ERR_PTR(-ENOMEM); 2783 } 2784 2785 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, 2786 struct sock *sk) 2787 { 2788 struct rtable *rt = __ip_route_output_key(net, flp4); 2789 2790 if (IS_ERR(rt)) 2791 return rt; 2792 2793 if (flp4->flowi4_proto) 2794 rt = (struct rtable *) xfrm_lookup(net, &rt->dst, 2795 flowi4_to_flowi(flp4), 2796 sk, 0); 2797 2798 return rt; 2799 } 2800 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2801 2802 static int rt_fill_info(struct net *net, 2803 struct sk_buff *skb, u32 pid, u32 seq, int event, 2804 int nowait, unsigned int flags) 2805 { 2806 struct rtable *rt = skb_rtable(skb); 2807 struct rtmsg *r; 2808 struct nlmsghdr *nlh; 2809 long expires = 0; 2810 const struct inet_peer *peer = rt->peer; 2811 u32 id = 0, ts = 0, tsage = 0, error; 2812 2813 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); 2814 if (nlh == NULL) 2815 return -EMSGSIZE; 2816 2817 r = nlmsg_data(nlh); 2818 r->rtm_family = AF_INET; 2819 r->rtm_dst_len = 32; 2820 r->rtm_src_len = 0; 2821 r->rtm_tos = rt->rt_key_tos; 2822 r->rtm_table = RT_TABLE_MAIN; 2823 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN); 2824 r->rtm_type = rt->rt_type; 2825 r->rtm_scope = RT_SCOPE_UNIVERSE; 2826 r->rtm_protocol = RTPROT_UNSPEC; 2827 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2828 if (rt->rt_flags & RTCF_NOTIFY) 2829 r->rtm_flags |= RTM_F_NOTIFY; 2830 2831 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst); 2832 2833 if (rt->rt_key_src) { 2834 r->rtm_src_len = 32; 2835 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src); 2836 } 2837 if (rt->dst.dev) 2838 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex); 2839 #ifdef CONFIG_IP_ROUTE_CLASSID 2840 if (rt->dst.tclassid) 2841 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid); 2842 #endif 2843 if (rt_is_input_route(rt)) 2844 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); 2845 else if (rt->rt_src != rt->rt_key_src) 2846 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src); 2847 2848 if (rt->rt_dst != rt->rt_gateway) 2849 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway); 2850 2851 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 2852 goto nla_put_failure; 2853 2854 if (rt->rt_mark) 2855 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark); 2856 2857 error = rt->dst.error; 2858 if (peer) { 2859 inet_peer_refcheck(rt->peer); 2860 id = atomic_read(&peer->ip_id_count) & 0xffff; 2861 if (peer->tcp_ts_stamp) { 2862 ts = peer->tcp_ts; 2863 tsage = get_seconds() - peer->tcp_ts_stamp; 2864 } 2865 expires = ACCESS_ONCE(peer->pmtu_expires); 2866 if (expires) 2867 expires -= jiffies; 2868 } 2869 2870 if (rt_is_input_route(rt)) { 2871 #ifdef CONFIG_IP_MROUTE 2872 __be32 dst = rt->rt_dst; 2873 2874 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2875 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2876 int err = ipmr_get_route(net, skb, 2877 rt->rt_src, rt->rt_dst, 2878 r, nowait); 2879 if (err <= 0) { 2880 if (!nowait) { 2881 if (err == 0) 2882 return 0; 2883 goto nla_put_failure; 2884 } else { 2885 if (err == -EMSGSIZE) 2886 goto nla_put_failure; 2887 error = err; 2888 } 2889 } 2890 } else 2891 #endif 2892 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif); 2893 } 2894 2895 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage, 2896 expires, error) < 0) 2897 goto nla_put_failure; 2898 2899 return nlmsg_end(skb, nlh); 2900 2901 nla_put_failure: 2902 nlmsg_cancel(skb, nlh); 2903 return -EMSGSIZE; 2904 } 2905 2906 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2907 { 2908 struct net *net = sock_net(in_skb->sk); 2909 struct rtmsg *rtm; 2910 struct nlattr *tb[RTA_MAX+1]; 2911 struct rtable *rt = NULL; 2912 __be32 dst = 0; 2913 __be32 src = 0; 2914 u32 iif; 2915 int err; 2916 int mark; 2917 struct sk_buff *skb; 2918 2919 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2920 if (err < 0) 2921 goto errout; 2922 2923 rtm = nlmsg_data(nlh); 2924 2925 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2926 if (skb == NULL) { 2927 err = -ENOBUFS; 2928 goto errout; 2929 } 2930 2931 /* Reserve room for dummy headers, this skb can pass 2932 through good chunk of routing engine. 2933 */ 2934 skb_reset_mac_header(skb); 2935 skb_reset_network_header(skb); 2936 2937 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2938 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2939 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2940 2941 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2942 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2943 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2944 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0; 2945 2946 if (iif) { 2947 struct net_device *dev; 2948 2949 dev = __dev_get_by_index(net, iif); 2950 if (dev == NULL) { 2951 err = -ENODEV; 2952 goto errout_free; 2953 } 2954 2955 skb->protocol = htons(ETH_P_IP); 2956 skb->dev = dev; 2957 skb->mark = mark; 2958 local_bh_disable(); 2959 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2960 local_bh_enable(); 2961 2962 rt = skb_rtable(skb); 2963 if (err == 0 && rt->dst.error) 2964 err = -rt->dst.error; 2965 } else { 2966 struct flowi4 fl4 = { 2967 .daddr = dst, 2968 .saddr = src, 2969 .flowi4_tos = rtm->rtm_tos, 2970 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, 2971 .flowi4_mark = mark, 2972 }; 2973 rt = ip_route_output_key(net, &fl4); 2974 2975 err = 0; 2976 if (IS_ERR(rt)) 2977 err = PTR_ERR(rt); 2978 } 2979 2980 if (err) 2981 goto errout_free; 2982 2983 skb_dst_set(skb, &rt->dst); 2984 if (rtm->rtm_flags & RTM_F_NOTIFY) 2985 rt->rt_flags |= RTCF_NOTIFY; 2986 2987 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 2988 RTM_NEWROUTE, 0, 0); 2989 if (err <= 0) 2990 goto errout_free; 2991 2992 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); 2993 errout: 2994 return err; 2995 2996 errout_free: 2997 kfree_skb(skb); 2998 goto errout; 2999 } 3000 3001 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) 3002 { 3003 struct rtable *rt; 3004 int h, s_h; 3005 int idx, s_idx; 3006 struct net *net; 3007 3008 net = sock_net(skb->sk); 3009 3010 s_h = cb->args[0]; 3011 if (s_h < 0) 3012 s_h = 0; 3013 s_idx = idx = cb->args[1]; 3014 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { 3015 if (!rt_hash_table[h].chain) 3016 continue; 3017 rcu_read_lock_bh(); 3018 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt; 3019 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) { 3020 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx) 3021 continue; 3022 if (rt_is_expired(rt)) 3023 continue; 3024 skb_dst_set_noref(skb, &rt->dst); 3025 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, 3026 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 3027 1, NLM_F_MULTI) <= 0) { 3028 skb_dst_drop(skb); 3029 rcu_read_unlock_bh(); 3030 goto done; 3031 } 3032 skb_dst_drop(skb); 3033 } 3034 rcu_read_unlock_bh(); 3035 } 3036 3037 done: 3038 cb->args[0] = h; 3039 cb->args[1] = idx; 3040 return skb->len; 3041 } 3042 3043 void ip_rt_multicast_event(struct in_device *in_dev) 3044 { 3045 rt_cache_flush(dev_net(in_dev->dev), 0); 3046 } 3047 3048 #ifdef CONFIG_SYSCTL 3049 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, 3050 void __user *buffer, 3051 size_t *lenp, loff_t *ppos) 3052 { 3053 if (write) { 3054 int flush_delay; 3055 ctl_table ctl; 3056 struct net *net; 3057 3058 memcpy(&ctl, __ctl, sizeof(ctl)); 3059 ctl.data = &flush_delay; 3060 proc_dointvec(&ctl, write, buffer, lenp, ppos); 3061 3062 net = (struct net *)__ctl->extra1; 3063 rt_cache_flush(net, flush_delay); 3064 return 0; 3065 } 3066 3067 return -EINVAL; 3068 } 3069 3070 static ctl_table ipv4_route_table[] = { 3071 { 3072 .procname = "gc_thresh", 3073 .data = &ipv4_dst_ops.gc_thresh, 3074 .maxlen = sizeof(int), 3075 .mode = 0644, 3076 .proc_handler = proc_dointvec, 3077 }, 3078 { 3079 .procname = "max_size", 3080 .data = &ip_rt_max_size, 3081 .maxlen = sizeof(int), 3082 .mode = 0644, 3083 .proc_handler = proc_dointvec, 3084 }, 3085 { 3086 /* Deprecated. Use gc_min_interval_ms */ 3087 3088 .procname = "gc_min_interval", 3089 .data = &ip_rt_gc_min_interval, 3090 .maxlen = sizeof(int), 3091 .mode = 0644, 3092 .proc_handler = proc_dointvec_jiffies, 3093 }, 3094 { 3095 .procname = "gc_min_interval_ms", 3096 .data = &ip_rt_gc_min_interval, 3097 .maxlen = sizeof(int), 3098 .mode = 0644, 3099 .proc_handler = proc_dointvec_ms_jiffies, 3100 }, 3101 { 3102 .procname = "gc_timeout", 3103 .data = &ip_rt_gc_timeout, 3104 .maxlen = sizeof(int), 3105 .mode = 0644, 3106 .proc_handler = proc_dointvec_jiffies, 3107 }, 3108 { 3109 .procname = "gc_interval", 3110 .data = &ip_rt_gc_interval, 3111 .maxlen = sizeof(int), 3112 .mode = 0644, 3113 .proc_handler = proc_dointvec_jiffies, 3114 }, 3115 { 3116 .procname = "redirect_load", 3117 .data = &ip_rt_redirect_load, 3118 .maxlen = sizeof(int), 3119 .mode = 0644, 3120 .proc_handler = proc_dointvec, 3121 }, 3122 { 3123 .procname = "redirect_number", 3124 .data = &ip_rt_redirect_number, 3125 .maxlen = sizeof(int), 3126 .mode = 0644, 3127 .proc_handler = proc_dointvec, 3128 }, 3129 { 3130 .procname = "redirect_silence", 3131 .data = &ip_rt_redirect_silence, 3132 .maxlen = sizeof(int), 3133 .mode = 0644, 3134 .proc_handler = proc_dointvec, 3135 }, 3136 { 3137 .procname = "error_cost", 3138 .data = &ip_rt_error_cost, 3139 .maxlen = sizeof(int), 3140 .mode = 0644, 3141 .proc_handler = proc_dointvec, 3142 }, 3143 { 3144 .procname = "error_burst", 3145 .data = &ip_rt_error_burst, 3146 .maxlen = sizeof(int), 3147 .mode = 0644, 3148 .proc_handler = proc_dointvec, 3149 }, 3150 { 3151 .procname = "gc_elasticity", 3152 .data = &ip_rt_gc_elasticity, 3153 .maxlen = sizeof(int), 3154 .mode = 0644, 3155 .proc_handler = proc_dointvec, 3156 }, 3157 { 3158 .procname = "mtu_expires", 3159 .data = &ip_rt_mtu_expires, 3160 .maxlen = sizeof(int), 3161 .mode = 0644, 3162 .proc_handler = proc_dointvec_jiffies, 3163 }, 3164 { 3165 .procname = "min_pmtu", 3166 .data = &ip_rt_min_pmtu, 3167 .maxlen = sizeof(int), 3168 .mode = 0644, 3169 .proc_handler = proc_dointvec, 3170 }, 3171 { 3172 .procname = "min_adv_mss", 3173 .data = &ip_rt_min_advmss, 3174 .maxlen = sizeof(int), 3175 .mode = 0644, 3176 .proc_handler = proc_dointvec, 3177 }, 3178 { } 3179 }; 3180 3181 static struct ctl_table empty[1]; 3182 3183 static struct ctl_table ipv4_skeleton[] = 3184 { 3185 { .procname = "route", 3186 .mode = 0555, .child = ipv4_route_table}, 3187 { .procname = "neigh", 3188 .mode = 0555, .child = empty}, 3189 { } 3190 }; 3191 3192 static __net_initdata struct ctl_path ipv4_path[] = { 3193 { .procname = "net", }, 3194 { .procname = "ipv4", }, 3195 { }, 3196 }; 3197 3198 static struct ctl_table ipv4_route_flush_table[] = { 3199 { 3200 .procname = "flush", 3201 .maxlen = sizeof(int), 3202 .mode = 0200, 3203 .proc_handler = ipv4_sysctl_rtcache_flush, 3204 }, 3205 { }, 3206 }; 3207 3208 static __net_initdata struct ctl_path ipv4_route_path[] = { 3209 { .procname = "net", }, 3210 { .procname = "ipv4", }, 3211 { .procname = "route", }, 3212 { }, 3213 }; 3214 3215 static __net_init int sysctl_route_net_init(struct net *net) 3216 { 3217 struct ctl_table *tbl; 3218 3219 tbl = ipv4_route_flush_table; 3220 if (!net_eq(net, &init_net)) { 3221 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3222 if (tbl == NULL) 3223 goto err_dup; 3224 } 3225 tbl[0].extra1 = net; 3226 3227 net->ipv4.route_hdr = 3228 register_net_sysctl_table(net, ipv4_route_path, tbl); 3229 if (net->ipv4.route_hdr == NULL) 3230 goto err_reg; 3231 return 0; 3232 3233 err_reg: 3234 if (tbl != ipv4_route_flush_table) 3235 kfree(tbl); 3236 err_dup: 3237 return -ENOMEM; 3238 } 3239 3240 static __net_exit void sysctl_route_net_exit(struct net *net) 3241 { 3242 struct ctl_table *tbl; 3243 3244 tbl = net->ipv4.route_hdr->ctl_table_arg; 3245 unregister_net_sysctl_table(net->ipv4.route_hdr); 3246 BUG_ON(tbl == ipv4_route_flush_table); 3247 kfree(tbl); 3248 } 3249 3250 static __net_initdata struct pernet_operations sysctl_route_ops = { 3251 .init = sysctl_route_net_init, 3252 .exit = sysctl_route_net_exit, 3253 }; 3254 #endif 3255 3256 static __net_init int rt_genid_init(struct net *net) 3257 { 3258 get_random_bytes(&net->ipv4.rt_genid, 3259 sizeof(net->ipv4.rt_genid)); 3260 get_random_bytes(&net->ipv4.dev_addr_genid, 3261 sizeof(net->ipv4.dev_addr_genid)); 3262 return 0; 3263 } 3264 3265 static __net_initdata struct pernet_operations rt_genid_ops = { 3266 .init = rt_genid_init, 3267 }; 3268 3269 3270 #ifdef CONFIG_IP_ROUTE_CLASSID 3271 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly; 3272 #endif /* CONFIG_IP_ROUTE_CLASSID */ 3273 3274 static __initdata unsigned long rhash_entries; 3275 static int __init set_rhash_entries(char *str) 3276 { 3277 if (!str) 3278 return 0; 3279 rhash_entries = simple_strtoul(str, &str, 0); 3280 return 1; 3281 } 3282 __setup("rhash_entries=", set_rhash_entries); 3283 3284 int __init ip_rt_init(void) 3285 { 3286 int rc = 0; 3287 3288 #ifdef CONFIG_IP_ROUTE_CLASSID 3289 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3290 if (!ip_rt_acct) 3291 panic("IP: failed to allocate ip_rt_acct\n"); 3292 #endif 3293 3294 ipv4_dst_ops.kmem_cachep = 3295 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3296 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3297 3298 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3299 3300 if (dst_entries_init(&ipv4_dst_ops) < 0) 3301 panic("IP: failed to allocate ipv4_dst_ops counter\n"); 3302 3303 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0) 3304 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n"); 3305 3306 rt_hash_table = (struct rt_hash_bucket *) 3307 alloc_large_system_hash("IP route cache", 3308 sizeof(struct rt_hash_bucket), 3309 rhash_entries, 3310 (totalram_pages >= 128 * 1024) ? 3311 15 : 17, 3312 0, 3313 &rt_hash_log, 3314 &rt_hash_mask, 3315 rhash_entries ? 0 : 512 * 1024); 3316 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); 3317 rt_hash_lock_init(); 3318 3319 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); 3320 ip_rt_max_size = (rt_hash_mask + 1) * 16; 3321 3322 devinet_init(); 3323 ip_fib_init(); 3324 3325 if (ip_rt_proc_init()) 3326 printk(KERN_ERR "Unable to create route proc files\n"); 3327 #ifdef CONFIG_XFRM 3328 xfrm_init(); 3329 xfrm4_init(ip_rt_max_size); 3330 #endif 3331 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL); 3332 3333 #ifdef CONFIG_SYSCTL 3334 register_pernet_subsys(&sysctl_route_ops); 3335 #endif 3336 register_pernet_subsys(&rt_genid_ops); 3337 return rc; 3338 } 3339 3340 #ifdef CONFIG_SYSCTL 3341 /* 3342 * We really need to sanitize the damn ipv4 init order, then all 3343 * this nonsense will go away. 3344 */ 3345 void __init ip_static_sysctl_init(void) 3346 { 3347 register_sysctl_paths(ipv4_path, ipv4_skeleton); 3348 } 3349 #endif 3350