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 <net/dst.h> 94 #include <net/net_namespace.h> 95 #include <net/protocol.h> 96 #include <net/ip.h> 97 #include <net/route.h> 98 #include <net/inetpeer.h> 99 #include <net/sock.h> 100 #include <net/ip_fib.h> 101 #include <net/arp.h> 102 #include <net/tcp.h> 103 #include <net/icmp.h> 104 #include <net/xfrm.h> 105 #include <net/netevent.h> 106 #include <net/rtnetlink.h> 107 #ifdef CONFIG_SYSCTL 108 #include <linux/sysctl.h> 109 #endif 110 111 #define RT_FL_TOS(oldflp) \ 112 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK))) 113 114 #define IP_MAX_MTU 0xFFF0 115 116 #define RT_GC_TIMEOUT (300*HZ) 117 118 static int ip_rt_max_size; 119 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT; 120 static int ip_rt_gc_interval __read_mostly = 60 * HZ; 121 static int ip_rt_gc_min_interval __read_mostly = HZ / 2; 122 static int ip_rt_redirect_number __read_mostly = 9; 123 static int ip_rt_redirect_load __read_mostly = HZ / 50; 124 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1)); 125 static int ip_rt_error_cost __read_mostly = HZ; 126 static int ip_rt_error_burst __read_mostly = 5 * HZ; 127 static int ip_rt_gc_elasticity __read_mostly = 8; 128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ; 129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20; 130 static int ip_rt_min_advmss __read_mostly = 256; 131 static int ip_rt_secret_interval __read_mostly = 10 * 60 * HZ; 132 static int rt_chain_length_max __read_mostly = 20; 133 134 static struct delayed_work expires_work; 135 static unsigned long expires_ljiffies; 136 137 /* 138 * Interface to generic destination cache. 139 */ 140 141 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie); 142 static void ipv4_dst_destroy(struct dst_entry *dst); 143 static void ipv4_dst_ifdown(struct dst_entry *dst, 144 struct net_device *dev, int how); 145 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst); 146 static void ipv4_link_failure(struct sk_buff *skb); 147 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 148 static int rt_garbage_collect(struct dst_ops *ops); 149 static void rt_emergency_hash_rebuild(struct net *net); 150 151 152 static struct dst_ops ipv4_dst_ops = { 153 .family = AF_INET, 154 .protocol = cpu_to_be16(ETH_P_IP), 155 .gc = rt_garbage_collect, 156 .check = ipv4_dst_check, 157 .destroy = ipv4_dst_destroy, 158 .ifdown = ipv4_dst_ifdown, 159 .negative_advice = ipv4_negative_advice, 160 .link_failure = ipv4_link_failure, 161 .update_pmtu = ip_rt_update_pmtu, 162 .local_out = __ip_local_out, 163 .entries = ATOMIC_INIT(0), 164 }; 165 166 #define ECN_OR_COST(class) TC_PRIO_##class 167 168 const __u8 ip_tos2prio[16] = { 169 TC_PRIO_BESTEFFORT, 170 ECN_OR_COST(FILLER), 171 TC_PRIO_BESTEFFORT, 172 ECN_OR_COST(BESTEFFORT), 173 TC_PRIO_BULK, 174 ECN_OR_COST(BULK), 175 TC_PRIO_BULK, 176 ECN_OR_COST(BULK), 177 TC_PRIO_INTERACTIVE, 178 ECN_OR_COST(INTERACTIVE), 179 TC_PRIO_INTERACTIVE, 180 ECN_OR_COST(INTERACTIVE), 181 TC_PRIO_INTERACTIVE_BULK, 182 ECN_OR_COST(INTERACTIVE_BULK), 183 TC_PRIO_INTERACTIVE_BULK, 184 ECN_OR_COST(INTERACTIVE_BULK) 185 }; 186 187 188 /* 189 * Route cache. 190 */ 191 192 /* The locking scheme is rather straight forward: 193 * 194 * 1) Read-Copy Update protects the buckets of the central route hash. 195 * 2) Only writers remove entries, and they hold the lock 196 * as they look at rtable reference counts. 197 * 3) Only readers acquire references to rtable entries, 198 * they do so with atomic increments and with the 199 * lock held. 200 */ 201 202 struct rt_hash_bucket { 203 struct rtable *chain; 204 }; 205 206 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \ 207 defined(CONFIG_PROVE_LOCKING) 208 /* 209 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks 210 * The size of this table is a power of two and depends on the number of CPUS. 211 * (on lockdep we have a quite big spinlock_t, so keep the size down there) 212 */ 213 #ifdef CONFIG_LOCKDEP 214 # define RT_HASH_LOCK_SZ 256 215 #else 216 # if NR_CPUS >= 32 217 # define RT_HASH_LOCK_SZ 4096 218 # elif NR_CPUS >= 16 219 # define RT_HASH_LOCK_SZ 2048 220 # elif NR_CPUS >= 8 221 # define RT_HASH_LOCK_SZ 1024 222 # elif NR_CPUS >= 4 223 # define RT_HASH_LOCK_SZ 512 224 # else 225 # define RT_HASH_LOCK_SZ 256 226 # endif 227 #endif 228 229 static spinlock_t *rt_hash_locks; 230 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)] 231 232 static __init void rt_hash_lock_init(void) 233 { 234 int i; 235 236 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, 237 GFP_KERNEL); 238 if (!rt_hash_locks) 239 panic("IP: failed to allocate rt_hash_locks\n"); 240 241 for (i = 0; i < RT_HASH_LOCK_SZ; i++) 242 spin_lock_init(&rt_hash_locks[i]); 243 } 244 #else 245 # define rt_hash_lock_addr(slot) NULL 246 247 static inline void rt_hash_lock_init(void) 248 { 249 } 250 #endif 251 252 static struct rt_hash_bucket *rt_hash_table __read_mostly; 253 static unsigned rt_hash_mask __read_mostly; 254 static unsigned int rt_hash_log __read_mostly; 255 256 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); 257 #define RT_CACHE_STAT_INC(field) \ 258 (__raw_get_cpu_var(rt_cache_stat).field++) 259 260 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx, 261 int genid) 262 { 263 return jhash_3words((__force u32)(__be32)(daddr), 264 (__force u32)(__be32)(saddr), 265 idx, genid) 266 & rt_hash_mask; 267 } 268 269 static inline int rt_genid(struct net *net) 270 { 271 return atomic_read(&net->ipv4.rt_genid); 272 } 273 274 #ifdef CONFIG_PROC_FS 275 struct rt_cache_iter_state { 276 struct seq_net_private p; 277 int bucket; 278 int genid; 279 }; 280 281 static struct rtable *rt_cache_get_first(struct seq_file *seq) 282 { 283 struct rt_cache_iter_state *st = seq->private; 284 struct rtable *r = NULL; 285 286 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) { 287 if (!rt_hash_table[st->bucket].chain) 288 continue; 289 rcu_read_lock_bh(); 290 r = rcu_dereference(rt_hash_table[st->bucket].chain); 291 while (r) { 292 if (dev_net(r->u.dst.dev) == seq_file_net(seq) && 293 r->rt_genid == st->genid) 294 return r; 295 r = rcu_dereference(r->u.dst.rt_next); 296 } 297 rcu_read_unlock_bh(); 298 } 299 return r; 300 } 301 302 static struct rtable *__rt_cache_get_next(struct seq_file *seq, 303 struct rtable *r) 304 { 305 struct rt_cache_iter_state *st = seq->private; 306 307 r = r->u.dst.rt_next; 308 while (!r) { 309 rcu_read_unlock_bh(); 310 do { 311 if (--st->bucket < 0) 312 return NULL; 313 } while (!rt_hash_table[st->bucket].chain); 314 rcu_read_lock_bh(); 315 r = rt_hash_table[st->bucket].chain; 316 } 317 return rcu_dereference(r); 318 } 319 320 static struct rtable *rt_cache_get_next(struct seq_file *seq, 321 struct rtable *r) 322 { 323 struct rt_cache_iter_state *st = seq->private; 324 while ((r = __rt_cache_get_next(seq, r)) != NULL) { 325 if (dev_net(r->u.dst.dev) != seq_file_net(seq)) 326 continue; 327 if (r->rt_genid == st->genid) 328 break; 329 } 330 return r; 331 } 332 333 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos) 334 { 335 struct rtable *r = rt_cache_get_first(seq); 336 337 if (r) 338 while (pos && (r = rt_cache_get_next(seq, r))) 339 --pos; 340 return pos ? NULL : r; 341 } 342 343 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) 344 { 345 struct rt_cache_iter_state *st = seq->private; 346 if (*pos) 347 return rt_cache_get_idx(seq, *pos - 1); 348 st->genid = rt_genid(seq_file_net(seq)); 349 return SEQ_START_TOKEN; 350 } 351 352 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos) 353 { 354 struct rtable *r; 355 356 if (v == SEQ_START_TOKEN) 357 r = rt_cache_get_first(seq); 358 else 359 r = rt_cache_get_next(seq, v); 360 ++*pos; 361 return r; 362 } 363 364 static void rt_cache_seq_stop(struct seq_file *seq, void *v) 365 { 366 if (v && v != SEQ_START_TOKEN) 367 rcu_read_unlock_bh(); 368 } 369 370 static int rt_cache_seq_show(struct seq_file *seq, void *v) 371 { 372 if (v == SEQ_START_TOKEN) 373 seq_printf(seq, "%-127s\n", 374 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t" 375 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t" 376 "HHUptod\tSpecDst"); 377 else { 378 struct rtable *r = v; 379 int len; 380 381 seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t" 382 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n", 383 r->u.dst.dev ? r->u.dst.dev->name : "*", 384 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway, 385 r->rt_flags, atomic_read(&r->u.dst.__refcnt), 386 r->u.dst.__use, 0, (unsigned long)r->rt_src, 387 (dst_metric(&r->u.dst, RTAX_ADVMSS) ? 388 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0), 389 dst_metric(&r->u.dst, RTAX_WINDOW), 390 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) + 391 dst_metric(&r->u.dst, RTAX_RTTVAR)), 392 r->fl.fl4_tos, 393 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1, 394 r->u.dst.hh ? (r->u.dst.hh->hh_output == 395 dev_queue_xmit) : 0, 396 r->rt_spec_dst, &len); 397 398 seq_printf(seq, "%*s\n", 127 - len, ""); 399 } 400 return 0; 401 } 402 403 static const struct seq_operations rt_cache_seq_ops = { 404 .start = rt_cache_seq_start, 405 .next = rt_cache_seq_next, 406 .stop = rt_cache_seq_stop, 407 .show = rt_cache_seq_show, 408 }; 409 410 static int rt_cache_seq_open(struct inode *inode, struct file *file) 411 { 412 return seq_open_net(inode, file, &rt_cache_seq_ops, 413 sizeof(struct rt_cache_iter_state)); 414 } 415 416 static const struct file_operations rt_cache_seq_fops = { 417 .owner = THIS_MODULE, 418 .open = rt_cache_seq_open, 419 .read = seq_read, 420 .llseek = seq_lseek, 421 .release = seq_release_net, 422 }; 423 424 425 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos) 426 { 427 int cpu; 428 429 if (*pos == 0) 430 return SEQ_START_TOKEN; 431 432 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) { 433 if (!cpu_possible(cpu)) 434 continue; 435 *pos = cpu+1; 436 return &per_cpu(rt_cache_stat, cpu); 437 } 438 return NULL; 439 } 440 441 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos) 442 { 443 int cpu; 444 445 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) { 446 if (!cpu_possible(cpu)) 447 continue; 448 *pos = cpu+1; 449 return &per_cpu(rt_cache_stat, cpu); 450 } 451 return NULL; 452 453 } 454 455 static void rt_cpu_seq_stop(struct seq_file *seq, void *v) 456 { 457 458 } 459 460 static int rt_cpu_seq_show(struct seq_file *seq, void *v) 461 { 462 struct rt_cache_stat *st = v; 463 464 if (v == SEQ_START_TOKEN) { 465 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"); 466 return 0; 467 } 468 469 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x " 470 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n", 471 atomic_read(&ipv4_dst_ops.entries), 472 st->in_hit, 473 st->in_slow_tot, 474 st->in_slow_mc, 475 st->in_no_route, 476 st->in_brd, 477 st->in_martian_dst, 478 st->in_martian_src, 479 480 st->out_hit, 481 st->out_slow_tot, 482 st->out_slow_mc, 483 484 st->gc_total, 485 st->gc_ignored, 486 st->gc_goal_miss, 487 st->gc_dst_overflow, 488 st->in_hlist_search, 489 st->out_hlist_search 490 ); 491 return 0; 492 } 493 494 static const struct seq_operations rt_cpu_seq_ops = { 495 .start = rt_cpu_seq_start, 496 .next = rt_cpu_seq_next, 497 .stop = rt_cpu_seq_stop, 498 .show = rt_cpu_seq_show, 499 }; 500 501 502 static int rt_cpu_seq_open(struct inode *inode, struct file *file) 503 { 504 return seq_open(file, &rt_cpu_seq_ops); 505 } 506 507 static const struct file_operations rt_cpu_seq_fops = { 508 .owner = THIS_MODULE, 509 .open = rt_cpu_seq_open, 510 .read = seq_read, 511 .llseek = seq_lseek, 512 .release = seq_release, 513 }; 514 515 #ifdef CONFIG_NET_CLS_ROUTE 516 static int ip_rt_acct_read(char *buffer, char **start, off_t offset, 517 int length, int *eof, void *data) 518 { 519 unsigned int i; 520 521 if ((offset & 3) || (length & 3)) 522 return -EIO; 523 524 if (offset >= sizeof(struct ip_rt_acct) * 256) { 525 *eof = 1; 526 return 0; 527 } 528 529 if (offset + length >= sizeof(struct ip_rt_acct) * 256) { 530 length = sizeof(struct ip_rt_acct) * 256 - offset; 531 *eof = 1; 532 } 533 534 offset /= sizeof(u32); 535 536 if (length > 0) { 537 u32 *dst = (u32 *) buffer; 538 539 *start = buffer; 540 memset(dst, 0, length); 541 542 for_each_possible_cpu(i) { 543 unsigned int j; 544 u32 *src; 545 546 src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset; 547 for (j = 0; j < length/4; j++) 548 dst[j] += src[j]; 549 } 550 } 551 return length; 552 } 553 #endif 554 555 static int __net_init ip_rt_do_proc_init(struct net *net) 556 { 557 struct proc_dir_entry *pde; 558 559 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO, 560 &rt_cache_seq_fops); 561 if (!pde) 562 goto err1; 563 564 pde = proc_create("rt_cache", S_IRUGO, 565 net->proc_net_stat, &rt_cpu_seq_fops); 566 if (!pde) 567 goto err2; 568 569 #ifdef CONFIG_NET_CLS_ROUTE 570 pde = create_proc_read_entry("rt_acct", 0, net->proc_net, 571 ip_rt_acct_read, NULL); 572 if (!pde) 573 goto err3; 574 #endif 575 return 0; 576 577 #ifdef CONFIG_NET_CLS_ROUTE 578 err3: 579 remove_proc_entry("rt_cache", net->proc_net_stat); 580 #endif 581 err2: 582 remove_proc_entry("rt_cache", net->proc_net); 583 err1: 584 return -ENOMEM; 585 } 586 587 static void __net_exit ip_rt_do_proc_exit(struct net *net) 588 { 589 remove_proc_entry("rt_cache", net->proc_net_stat); 590 remove_proc_entry("rt_cache", net->proc_net); 591 remove_proc_entry("rt_acct", net->proc_net); 592 } 593 594 static struct pernet_operations ip_rt_proc_ops __net_initdata = { 595 .init = ip_rt_do_proc_init, 596 .exit = ip_rt_do_proc_exit, 597 }; 598 599 static int __init ip_rt_proc_init(void) 600 { 601 return register_pernet_subsys(&ip_rt_proc_ops); 602 } 603 604 #else 605 static inline int ip_rt_proc_init(void) 606 { 607 return 0; 608 } 609 #endif /* CONFIG_PROC_FS */ 610 611 static inline void rt_free(struct rtable *rt) 612 { 613 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free); 614 } 615 616 static inline void rt_drop(struct rtable *rt) 617 { 618 ip_rt_put(rt); 619 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free); 620 } 621 622 static inline int rt_fast_clean(struct rtable *rth) 623 { 624 /* Kill broadcast/multicast entries very aggresively, if they 625 collide in hash table with more useful entries */ 626 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) && 627 rth->fl.iif && rth->u.dst.rt_next; 628 } 629 630 static inline int rt_valuable(struct rtable *rth) 631 { 632 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) || 633 rth->u.dst.expires; 634 } 635 636 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2) 637 { 638 unsigned long age; 639 int ret = 0; 640 641 if (atomic_read(&rth->u.dst.__refcnt)) 642 goto out; 643 644 ret = 1; 645 if (rth->u.dst.expires && 646 time_after_eq(jiffies, rth->u.dst.expires)) 647 goto out; 648 649 age = jiffies - rth->u.dst.lastuse; 650 ret = 0; 651 if ((age <= tmo1 && !rt_fast_clean(rth)) || 652 (age <= tmo2 && rt_valuable(rth))) 653 goto out; 654 ret = 1; 655 out: return ret; 656 } 657 658 /* Bits of score are: 659 * 31: very valuable 660 * 30: not quite useless 661 * 29..0: usage counter 662 */ 663 static inline u32 rt_score(struct rtable *rt) 664 { 665 u32 score = jiffies - rt->u.dst.lastuse; 666 667 score = ~score & ~(3<<30); 668 669 if (rt_valuable(rt)) 670 score |= (1<<31); 671 672 if (!rt->fl.iif || 673 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL))) 674 score |= (1<<30); 675 676 return score; 677 } 678 679 static inline bool rt_caching(const struct net *net) 680 { 681 return net->ipv4.current_rt_cache_rebuild_count <= 682 net->ipv4.sysctl_rt_cache_rebuild_count; 683 } 684 685 static inline bool compare_hash_inputs(const struct flowi *fl1, 686 const struct flowi *fl2) 687 { 688 return (__force u32)(((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) | 689 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr) | 690 (fl1->iif ^ fl2->iif)) == 0); 691 } 692 693 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2) 694 { 695 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) | 696 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) | 697 (fl1->mark ^ fl2->mark) | 698 (*(u16 *)&fl1->nl_u.ip4_u.tos ^ 699 *(u16 *)&fl2->nl_u.ip4_u.tos) | 700 (fl1->oif ^ fl2->oif) | 701 (fl1->iif ^ fl2->iif)) == 0; 702 } 703 704 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2) 705 { 706 return dev_net(rt1->u.dst.dev) == dev_net(rt2->u.dst.dev); 707 } 708 709 static inline int rt_is_expired(struct rtable *rth) 710 { 711 return rth->rt_genid != rt_genid(dev_net(rth->u.dst.dev)); 712 } 713 714 /* 715 * Perform a full scan of hash table and free all entries. 716 * Can be called by a softirq or a process. 717 * In the later case, we want to be reschedule if necessary 718 */ 719 static void rt_do_flush(int process_context) 720 { 721 unsigned int i; 722 struct rtable *rth, *next; 723 struct rtable * tail; 724 725 for (i = 0; i <= rt_hash_mask; i++) { 726 if (process_context && need_resched()) 727 cond_resched(); 728 rth = rt_hash_table[i].chain; 729 if (!rth) 730 continue; 731 732 spin_lock_bh(rt_hash_lock_addr(i)); 733 #ifdef CONFIG_NET_NS 734 { 735 struct rtable ** prev, * p; 736 737 rth = rt_hash_table[i].chain; 738 739 /* defer releasing the head of the list after spin_unlock */ 740 for (tail = rth; tail; tail = tail->u.dst.rt_next) 741 if (!rt_is_expired(tail)) 742 break; 743 if (rth != tail) 744 rt_hash_table[i].chain = tail; 745 746 /* call rt_free on entries after the tail requiring flush */ 747 prev = &rt_hash_table[i].chain; 748 for (p = *prev; p; p = next) { 749 next = p->u.dst.rt_next; 750 if (!rt_is_expired(p)) { 751 prev = &p->u.dst.rt_next; 752 } else { 753 *prev = next; 754 rt_free(p); 755 } 756 } 757 } 758 #else 759 rth = rt_hash_table[i].chain; 760 rt_hash_table[i].chain = NULL; 761 tail = NULL; 762 #endif 763 spin_unlock_bh(rt_hash_lock_addr(i)); 764 765 for (; rth != tail; rth = next) { 766 next = rth->u.dst.rt_next; 767 rt_free(rth); 768 } 769 } 770 } 771 772 /* 773 * While freeing expired entries, we compute average chain length 774 * and standard deviation, using fixed-point arithmetic. 775 * This to have an estimation of rt_chain_length_max 776 * rt_chain_length_max = max(elasticity, AVG + 4*SD) 777 * We use 3 bits for frational part, and 29 (or 61) for magnitude. 778 */ 779 780 #define FRACT_BITS 3 781 #define ONE (1UL << FRACT_BITS) 782 783 static void rt_check_expire(void) 784 { 785 static unsigned int rover; 786 unsigned int i = rover, goal; 787 struct rtable *rth, *aux, **rthp; 788 unsigned long samples = 0; 789 unsigned long sum = 0, sum2 = 0; 790 unsigned long delta; 791 u64 mult; 792 793 delta = jiffies - expires_ljiffies; 794 expires_ljiffies = jiffies; 795 mult = ((u64)delta) << rt_hash_log; 796 if (ip_rt_gc_timeout > 1) 797 do_div(mult, ip_rt_gc_timeout); 798 goal = (unsigned int)mult; 799 if (goal > rt_hash_mask) 800 goal = rt_hash_mask + 1; 801 for (; goal > 0; goal--) { 802 unsigned long tmo = ip_rt_gc_timeout; 803 unsigned long length; 804 805 i = (i + 1) & rt_hash_mask; 806 rthp = &rt_hash_table[i].chain; 807 808 if (need_resched()) 809 cond_resched(); 810 811 samples++; 812 813 if (*rthp == NULL) 814 continue; 815 length = 0; 816 spin_lock_bh(rt_hash_lock_addr(i)); 817 while ((rth = *rthp) != NULL) { 818 prefetch(rth->u.dst.rt_next); 819 if (rt_is_expired(rth)) { 820 *rthp = rth->u.dst.rt_next; 821 rt_free(rth); 822 continue; 823 } 824 if (rth->u.dst.expires) { 825 /* Entry is expired even if it is in use */ 826 if (time_before_eq(jiffies, rth->u.dst.expires)) { 827 nofree: 828 tmo >>= 1; 829 rthp = &rth->u.dst.rt_next; 830 /* 831 * We only count entries on 832 * a chain with equal hash inputs once 833 * so that entries for different QOS 834 * levels, and other non-hash input 835 * attributes don't unfairly skew 836 * the length computation 837 */ 838 for (aux = rt_hash_table[i].chain;;) { 839 if (aux == rth) { 840 length += ONE; 841 break; 842 } 843 if (compare_hash_inputs(&aux->fl, &rth->fl)) 844 break; 845 aux = aux->u.dst.rt_next; 846 } 847 continue; 848 } 849 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) 850 goto nofree; 851 852 /* Cleanup aged off entries. */ 853 *rthp = rth->u.dst.rt_next; 854 rt_free(rth); 855 } 856 spin_unlock_bh(rt_hash_lock_addr(i)); 857 sum += length; 858 sum2 += length*length; 859 } 860 if (samples) { 861 unsigned long avg = sum / samples; 862 unsigned long sd = int_sqrt(sum2 / samples - avg*avg); 863 rt_chain_length_max = max_t(unsigned long, 864 ip_rt_gc_elasticity, 865 (avg + 4*sd) >> FRACT_BITS); 866 } 867 rover = i; 868 } 869 870 /* 871 * rt_worker_func() is run in process context. 872 * we call rt_check_expire() to scan part of the hash table 873 */ 874 static void rt_worker_func(struct work_struct *work) 875 { 876 rt_check_expire(); 877 schedule_delayed_work(&expires_work, ip_rt_gc_interval); 878 } 879 880 /* 881 * Pertubation of rt_genid by a small quantity [1..256] 882 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() 883 * many times (2^24) without giving recent rt_genid. 884 * Jenkins hash is strong enough that litle changes of rt_genid are OK. 885 */ 886 static void rt_cache_invalidate(struct net *net) 887 { 888 unsigned char shuffle; 889 890 get_random_bytes(&shuffle, sizeof(shuffle)); 891 atomic_add(shuffle + 1U, &net->ipv4.rt_genid); 892 } 893 894 /* 895 * delay < 0 : invalidate cache (fast : entries will be deleted later) 896 * delay >= 0 : invalidate & flush cache (can be long) 897 */ 898 void rt_cache_flush(struct net *net, int delay) 899 { 900 rt_cache_invalidate(net); 901 if (delay >= 0) 902 rt_do_flush(!in_softirq()); 903 } 904 905 /* 906 * We change rt_genid and let gc do the cleanup 907 */ 908 static void rt_secret_rebuild(unsigned long __net) 909 { 910 struct net *net = (struct net *)__net; 911 rt_cache_invalidate(net); 912 mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval); 913 } 914 915 static void rt_secret_rebuild_oneshot(struct net *net) 916 { 917 del_timer_sync(&net->ipv4.rt_secret_timer); 918 rt_cache_invalidate(net); 919 if (ip_rt_secret_interval) { 920 net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval; 921 add_timer(&net->ipv4.rt_secret_timer); 922 } 923 } 924 925 static void rt_emergency_hash_rebuild(struct net *net) 926 { 927 if (net_ratelimit()) { 928 printk(KERN_WARNING "Route hash chain too long!\n"); 929 printk(KERN_WARNING "Adjust your secret_interval!\n"); 930 } 931 932 rt_secret_rebuild_oneshot(net); 933 } 934 935 /* 936 Short description of GC goals. 937 938 We want to build algorithm, which will keep routing cache 939 at some equilibrium point, when number of aged off entries 940 is kept approximately equal to newly generated ones. 941 942 Current expiration strength is variable "expire". 943 We try to adjust it dynamically, so that if networking 944 is idle expires is large enough to keep enough of warm entries, 945 and when load increases it reduces to limit cache size. 946 */ 947 948 static int rt_garbage_collect(struct dst_ops *ops) 949 { 950 static unsigned long expire = RT_GC_TIMEOUT; 951 static unsigned long last_gc; 952 static int rover; 953 static int equilibrium; 954 struct rtable *rth, **rthp; 955 unsigned long now = jiffies; 956 int goal; 957 958 /* 959 * Garbage collection is pretty expensive, 960 * do not make it too frequently. 961 */ 962 963 RT_CACHE_STAT_INC(gc_total); 964 965 if (now - last_gc < ip_rt_gc_min_interval && 966 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) { 967 RT_CACHE_STAT_INC(gc_ignored); 968 goto out; 969 } 970 971 /* Calculate number of entries, which we want to expire now. */ 972 goal = atomic_read(&ipv4_dst_ops.entries) - 973 (ip_rt_gc_elasticity << rt_hash_log); 974 if (goal <= 0) { 975 if (equilibrium < ipv4_dst_ops.gc_thresh) 976 equilibrium = ipv4_dst_ops.gc_thresh; 977 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium; 978 if (goal > 0) { 979 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1); 980 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium; 981 } 982 } else { 983 /* We are in dangerous area. Try to reduce cache really 984 * aggressively. 985 */ 986 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1); 987 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal; 988 } 989 990 if (now - last_gc >= ip_rt_gc_min_interval) 991 last_gc = now; 992 993 if (goal <= 0) { 994 equilibrium += goal; 995 goto work_done; 996 } 997 998 do { 999 int i, k; 1000 1001 for (i = rt_hash_mask, k = rover; i >= 0; i--) { 1002 unsigned long tmo = expire; 1003 1004 k = (k + 1) & rt_hash_mask; 1005 rthp = &rt_hash_table[k].chain; 1006 spin_lock_bh(rt_hash_lock_addr(k)); 1007 while ((rth = *rthp) != NULL) { 1008 if (!rt_is_expired(rth) && 1009 !rt_may_expire(rth, tmo, expire)) { 1010 tmo >>= 1; 1011 rthp = &rth->u.dst.rt_next; 1012 continue; 1013 } 1014 *rthp = rth->u.dst.rt_next; 1015 rt_free(rth); 1016 goal--; 1017 } 1018 spin_unlock_bh(rt_hash_lock_addr(k)); 1019 if (goal <= 0) 1020 break; 1021 } 1022 rover = k; 1023 1024 if (goal <= 0) 1025 goto work_done; 1026 1027 /* Goal is not achieved. We stop process if: 1028 1029 - if expire reduced to zero. Otherwise, expire is halfed. 1030 - if table is not full. 1031 - if we are called from interrupt. 1032 - jiffies check is just fallback/debug loop breaker. 1033 We will not spin here for long time in any case. 1034 */ 1035 1036 RT_CACHE_STAT_INC(gc_goal_miss); 1037 1038 if (expire == 0) 1039 break; 1040 1041 expire >>= 1; 1042 #if RT_CACHE_DEBUG >= 2 1043 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire, 1044 atomic_read(&ipv4_dst_ops.entries), goal, i); 1045 #endif 1046 1047 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) 1048 goto out; 1049 } while (!in_softirq() && time_before_eq(jiffies, now)); 1050 1051 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) 1052 goto out; 1053 if (net_ratelimit()) 1054 printk(KERN_WARNING "dst cache overflow\n"); 1055 RT_CACHE_STAT_INC(gc_dst_overflow); 1056 return 1; 1057 1058 work_done: 1059 expire += ip_rt_gc_min_interval; 1060 if (expire > ip_rt_gc_timeout || 1061 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh) 1062 expire = ip_rt_gc_timeout; 1063 #if RT_CACHE_DEBUG >= 2 1064 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire, 1065 atomic_read(&ipv4_dst_ops.entries), goal, rover); 1066 #endif 1067 out: return 0; 1068 } 1069 1070 static int rt_intern_hash(unsigned hash, struct rtable *rt, 1071 struct rtable **rp, struct sk_buff *skb) 1072 { 1073 struct rtable *rth, **rthp; 1074 unsigned long now; 1075 struct rtable *cand, **candp; 1076 u32 min_score; 1077 int chain_length; 1078 int attempts = !in_softirq(); 1079 1080 restart: 1081 chain_length = 0; 1082 min_score = ~(u32)0; 1083 cand = NULL; 1084 candp = NULL; 1085 now = jiffies; 1086 1087 if (!rt_caching(dev_net(rt->u.dst.dev))) { 1088 /* 1089 * If we're not caching, just tell the caller we 1090 * were successful and don't touch the route. The 1091 * caller hold the sole reference to the cache entry, and 1092 * it will be released when the caller is done with it. 1093 * If we drop it here, the callers have no way to resolve routes 1094 * when we're not caching. Instead, just point *rp at rt, so 1095 * the caller gets a single use out of the route 1096 * Note that we do rt_free on this new route entry, so that 1097 * once its refcount hits zero, we are still able to reap it 1098 * (Thanks Alexey) 1099 * Note also the rt_free uses call_rcu. We don't actually 1100 * need rcu protection here, this is just our path to get 1101 * on the route gc list. 1102 */ 1103 1104 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) { 1105 int err = arp_bind_neighbour(&rt->u.dst); 1106 if (err) { 1107 if (net_ratelimit()) 1108 printk(KERN_WARNING 1109 "Neighbour table failure & not caching routes.\n"); 1110 rt_drop(rt); 1111 return err; 1112 } 1113 } 1114 1115 rt_free(rt); 1116 goto skip_hashing; 1117 } 1118 1119 rthp = &rt_hash_table[hash].chain; 1120 1121 spin_lock_bh(rt_hash_lock_addr(hash)); 1122 while ((rth = *rthp) != NULL) { 1123 if (rt_is_expired(rth)) { 1124 *rthp = rth->u.dst.rt_next; 1125 rt_free(rth); 1126 continue; 1127 } 1128 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) { 1129 /* Put it first */ 1130 *rthp = rth->u.dst.rt_next; 1131 /* 1132 * Since lookup is lockfree, the deletion 1133 * must be visible to another weakly ordered CPU before 1134 * the insertion at the start of the hash chain. 1135 */ 1136 rcu_assign_pointer(rth->u.dst.rt_next, 1137 rt_hash_table[hash].chain); 1138 /* 1139 * Since lookup is lockfree, the update writes 1140 * must be ordered for consistency on SMP. 1141 */ 1142 rcu_assign_pointer(rt_hash_table[hash].chain, rth); 1143 1144 dst_use(&rth->u.dst, now); 1145 spin_unlock_bh(rt_hash_lock_addr(hash)); 1146 1147 rt_drop(rt); 1148 if (rp) 1149 *rp = rth; 1150 else 1151 skb_dst_set(skb, &rth->u.dst); 1152 return 0; 1153 } 1154 1155 if (!atomic_read(&rth->u.dst.__refcnt)) { 1156 u32 score = rt_score(rth); 1157 1158 if (score <= min_score) { 1159 cand = rth; 1160 candp = rthp; 1161 min_score = score; 1162 } 1163 } 1164 1165 chain_length++; 1166 1167 rthp = &rth->u.dst.rt_next; 1168 } 1169 1170 if (cand) { 1171 /* ip_rt_gc_elasticity used to be average length of chain 1172 * length, when exceeded gc becomes really aggressive. 1173 * 1174 * The second limit is less certain. At the moment it allows 1175 * only 2 entries per bucket. We will see. 1176 */ 1177 if (chain_length > ip_rt_gc_elasticity) { 1178 *candp = cand->u.dst.rt_next; 1179 rt_free(cand); 1180 } 1181 } else { 1182 if (chain_length > rt_chain_length_max) { 1183 struct net *net = dev_net(rt->u.dst.dev); 1184 int num = ++net->ipv4.current_rt_cache_rebuild_count; 1185 if (!rt_caching(dev_net(rt->u.dst.dev))) { 1186 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n", 1187 rt->u.dst.dev->name, num); 1188 } 1189 rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev)); 1190 } 1191 } 1192 1193 /* Try to bind route to arp only if it is output 1194 route or unicast forwarding path. 1195 */ 1196 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) { 1197 int err = arp_bind_neighbour(&rt->u.dst); 1198 if (err) { 1199 spin_unlock_bh(rt_hash_lock_addr(hash)); 1200 1201 if (err != -ENOBUFS) { 1202 rt_drop(rt); 1203 return err; 1204 } 1205 1206 /* Neighbour tables are full and nothing 1207 can be released. Try to shrink route cache, 1208 it is most likely it holds some neighbour records. 1209 */ 1210 if (attempts-- > 0) { 1211 int saved_elasticity = ip_rt_gc_elasticity; 1212 int saved_int = ip_rt_gc_min_interval; 1213 ip_rt_gc_elasticity = 1; 1214 ip_rt_gc_min_interval = 0; 1215 rt_garbage_collect(&ipv4_dst_ops); 1216 ip_rt_gc_min_interval = saved_int; 1217 ip_rt_gc_elasticity = saved_elasticity; 1218 goto restart; 1219 } 1220 1221 if (net_ratelimit()) 1222 printk(KERN_WARNING "Neighbour table overflow.\n"); 1223 rt_drop(rt); 1224 return -ENOBUFS; 1225 } 1226 } 1227 1228 rt->u.dst.rt_next = rt_hash_table[hash].chain; 1229 1230 #if RT_CACHE_DEBUG >= 2 1231 if (rt->u.dst.rt_next) { 1232 struct rtable *trt; 1233 printk(KERN_DEBUG "rt_cache @%02x: %pI4", 1234 hash, &rt->rt_dst); 1235 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next) 1236 printk(" . %pI4", &trt->rt_dst); 1237 printk("\n"); 1238 } 1239 #endif 1240 /* 1241 * Since lookup is lockfree, we must make sure 1242 * previous writes to rt are comitted to memory 1243 * before making rt visible to other CPUS. 1244 */ 1245 rcu_assign_pointer(rt_hash_table[hash].chain, rt); 1246 1247 spin_unlock_bh(rt_hash_lock_addr(hash)); 1248 1249 skip_hashing: 1250 if (rp) 1251 *rp = rt; 1252 else 1253 skb_dst_set(skb, &rt->u.dst); 1254 return 0; 1255 } 1256 1257 void rt_bind_peer(struct rtable *rt, int create) 1258 { 1259 static DEFINE_SPINLOCK(rt_peer_lock); 1260 struct inet_peer *peer; 1261 1262 peer = inet_getpeer(rt->rt_dst, create); 1263 1264 spin_lock_bh(&rt_peer_lock); 1265 if (rt->peer == NULL) { 1266 rt->peer = peer; 1267 peer = NULL; 1268 } 1269 spin_unlock_bh(&rt_peer_lock); 1270 if (peer) 1271 inet_putpeer(peer); 1272 } 1273 1274 /* 1275 * Peer allocation may fail only in serious out-of-memory conditions. However 1276 * we still can generate some output. 1277 * Random ID selection looks a bit dangerous because we have no chances to 1278 * select ID being unique in a reasonable period of time. 1279 * But broken packet identifier may be better than no packet at all. 1280 */ 1281 static void ip_select_fb_ident(struct iphdr *iph) 1282 { 1283 static DEFINE_SPINLOCK(ip_fb_id_lock); 1284 static u32 ip_fallback_id; 1285 u32 salt; 1286 1287 spin_lock_bh(&ip_fb_id_lock); 1288 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr); 1289 iph->id = htons(salt & 0xFFFF); 1290 ip_fallback_id = salt; 1291 spin_unlock_bh(&ip_fb_id_lock); 1292 } 1293 1294 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more) 1295 { 1296 struct rtable *rt = (struct rtable *) dst; 1297 1298 if (rt) { 1299 if (rt->peer == NULL) 1300 rt_bind_peer(rt, 1); 1301 1302 /* If peer is attached to destination, it is never detached, 1303 so that we need not to grab a lock to dereference it. 1304 */ 1305 if (rt->peer) { 1306 iph->id = htons(inet_getid(rt->peer, more)); 1307 return; 1308 } 1309 } else 1310 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", 1311 __builtin_return_address(0)); 1312 1313 ip_select_fb_ident(iph); 1314 } 1315 1316 static void rt_del(unsigned hash, struct rtable *rt) 1317 { 1318 struct rtable **rthp, *aux; 1319 1320 rthp = &rt_hash_table[hash].chain; 1321 spin_lock_bh(rt_hash_lock_addr(hash)); 1322 ip_rt_put(rt); 1323 while ((aux = *rthp) != NULL) { 1324 if (aux == rt || rt_is_expired(aux)) { 1325 *rthp = aux->u.dst.rt_next; 1326 rt_free(aux); 1327 continue; 1328 } 1329 rthp = &aux->u.dst.rt_next; 1330 } 1331 spin_unlock_bh(rt_hash_lock_addr(hash)); 1332 } 1333 1334 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, 1335 __be32 saddr, struct net_device *dev) 1336 { 1337 int i, k; 1338 struct in_device *in_dev = in_dev_get(dev); 1339 struct rtable *rth, **rthp; 1340 __be32 skeys[2] = { saddr, 0 }; 1341 int ikeys[2] = { dev->ifindex, 0 }; 1342 struct netevent_redirect netevent; 1343 struct net *net; 1344 1345 if (!in_dev) 1346 return; 1347 1348 net = dev_net(dev); 1349 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) 1350 || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) 1351 || ipv4_is_zeronet(new_gw)) 1352 goto reject_redirect; 1353 1354 if (!rt_caching(net)) 1355 goto reject_redirect; 1356 1357 if (!IN_DEV_SHARED_MEDIA(in_dev)) { 1358 if (!inet_addr_onlink(in_dev, new_gw, old_gw)) 1359 goto reject_redirect; 1360 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev)) 1361 goto reject_redirect; 1362 } else { 1363 if (inet_addr_type(net, new_gw) != RTN_UNICAST) 1364 goto reject_redirect; 1365 } 1366 1367 for (i = 0; i < 2; i++) { 1368 for (k = 0; k < 2; k++) { 1369 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k], 1370 rt_genid(net)); 1371 1372 rthp=&rt_hash_table[hash].chain; 1373 1374 rcu_read_lock(); 1375 while ((rth = rcu_dereference(*rthp)) != NULL) { 1376 struct rtable *rt; 1377 1378 if (rth->fl.fl4_dst != daddr || 1379 rth->fl.fl4_src != skeys[i] || 1380 rth->fl.oif != ikeys[k] || 1381 rth->fl.iif != 0 || 1382 rt_is_expired(rth) || 1383 !net_eq(dev_net(rth->u.dst.dev), net)) { 1384 rthp = &rth->u.dst.rt_next; 1385 continue; 1386 } 1387 1388 if (rth->rt_dst != daddr || 1389 rth->rt_src != saddr || 1390 rth->u.dst.error || 1391 rth->rt_gateway != old_gw || 1392 rth->u.dst.dev != dev) 1393 break; 1394 1395 dst_hold(&rth->u.dst); 1396 rcu_read_unlock(); 1397 1398 rt = dst_alloc(&ipv4_dst_ops); 1399 if (rt == NULL) { 1400 ip_rt_put(rth); 1401 in_dev_put(in_dev); 1402 return; 1403 } 1404 1405 /* Copy all the information. */ 1406 *rt = *rth; 1407 rt->u.dst.__use = 1; 1408 atomic_set(&rt->u.dst.__refcnt, 1); 1409 rt->u.dst.child = NULL; 1410 if (rt->u.dst.dev) 1411 dev_hold(rt->u.dst.dev); 1412 if (rt->idev) 1413 in_dev_hold(rt->idev); 1414 rt->u.dst.obsolete = 0; 1415 rt->u.dst.lastuse = jiffies; 1416 rt->u.dst.path = &rt->u.dst; 1417 rt->u.dst.neighbour = NULL; 1418 rt->u.dst.hh = NULL; 1419 #ifdef CONFIG_XFRM 1420 rt->u.dst.xfrm = NULL; 1421 #endif 1422 rt->rt_genid = rt_genid(net); 1423 rt->rt_flags |= RTCF_REDIRECTED; 1424 1425 /* Gateway is different ... */ 1426 rt->rt_gateway = new_gw; 1427 1428 /* Redirect received -> path was valid */ 1429 dst_confirm(&rth->u.dst); 1430 1431 if (rt->peer) 1432 atomic_inc(&rt->peer->refcnt); 1433 1434 if (arp_bind_neighbour(&rt->u.dst) || 1435 !(rt->u.dst.neighbour->nud_state & 1436 NUD_VALID)) { 1437 if (rt->u.dst.neighbour) 1438 neigh_event_send(rt->u.dst.neighbour, NULL); 1439 ip_rt_put(rth); 1440 rt_drop(rt); 1441 goto do_next; 1442 } 1443 1444 netevent.old = &rth->u.dst; 1445 netevent.new = &rt->u.dst; 1446 call_netevent_notifiers(NETEVENT_REDIRECT, 1447 &netevent); 1448 1449 rt_del(hash, rth); 1450 if (!rt_intern_hash(hash, rt, &rt, NULL)) 1451 ip_rt_put(rt); 1452 goto do_next; 1453 } 1454 rcu_read_unlock(); 1455 do_next: 1456 ; 1457 } 1458 } 1459 in_dev_put(in_dev); 1460 return; 1461 1462 reject_redirect: 1463 #ifdef CONFIG_IP_ROUTE_VERBOSE 1464 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 1465 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n" 1466 " Advised path = %pI4 -> %pI4\n", 1467 &old_gw, dev->name, &new_gw, 1468 &saddr, &daddr); 1469 #endif 1470 in_dev_put(in_dev); 1471 } 1472 1473 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) 1474 { 1475 struct rtable *rt = (struct rtable *)dst; 1476 struct dst_entry *ret = dst; 1477 1478 if (rt) { 1479 if (dst->obsolete) { 1480 ip_rt_put(rt); 1481 ret = NULL; 1482 } else if ((rt->rt_flags & RTCF_REDIRECTED) || 1483 rt->u.dst.expires) { 1484 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src, 1485 rt->fl.oif, 1486 rt_genid(dev_net(dst->dev))); 1487 #if RT_CACHE_DEBUG >= 1 1488 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n", 1489 &rt->rt_dst, rt->fl.fl4_tos); 1490 #endif 1491 rt_del(hash, rt); 1492 ret = NULL; 1493 } 1494 } 1495 return ret; 1496 } 1497 1498 /* 1499 * Algorithm: 1500 * 1. The first ip_rt_redirect_number redirects are sent 1501 * with exponential backoff, then we stop sending them at all, 1502 * assuming that the host ignores our redirects. 1503 * 2. If we did not see packets requiring redirects 1504 * during ip_rt_redirect_silence, we assume that the host 1505 * forgot redirected route and start to send redirects again. 1506 * 1507 * This algorithm is much cheaper and more intelligent than dumb load limiting 1508 * in icmp.c. 1509 * 1510 * NOTE. Do not forget to inhibit load limiting for redirects (redundant) 1511 * and "frag. need" (breaks PMTU discovery) in icmp.c. 1512 */ 1513 1514 void ip_rt_send_redirect(struct sk_buff *skb) 1515 { 1516 struct rtable *rt = skb_rtable(skb); 1517 struct in_device *in_dev; 1518 int log_martians; 1519 1520 rcu_read_lock(); 1521 in_dev = __in_dev_get_rcu(rt->u.dst.dev); 1522 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) { 1523 rcu_read_unlock(); 1524 return; 1525 } 1526 log_martians = IN_DEV_LOG_MARTIANS(in_dev); 1527 rcu_read_unlock(); 1528 1529 /* No redirected packets during ip_rt_redirect_silence; 1530 * reset the algorithm. 1531 */ 1532 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence)) 1533 rt->u.dst.rate_tokens = 0; 1534 1535 /* Too many ignored redirects; do not send anything 1536 * set u.dst.rate_last to the last seen redirected packet. 1537 */ 1538 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) { 1539 rt->u.dst.rate_last = jiffies; 1540 return; 1541 } 1542 1543 /* Check for load limit; set rate_last to the latest sent 1544 * redirect. 1545 */ 1546 if (rt->u.dst.rate_tokens == 0 || 1547 time_after(jiffies, 1548 (rt->u.dst.rate_last + 1549 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) { 1550 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway); 1551 rt->u.dst.rate_last = jiffies; 1552 ++rt->u.dst.rate_tokens; 1553 #ifdef CONFIG_IP_ROUTE_VERBOSE 1554 if (log_martians && 1555 rt->u.dst.rate_tokens == ip_rt_redirect_number && 1556 net_ratelimit()) 1557 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n", 1558 &rt->rt_src, rt->rt_iif, 1559 &rt->rt_dst, &rt->rt_gateway); 1560 #endif 1561 } 1562 } 1563 1564 static int ip_error(struct sk_buff *skb) 1565 { 1566 struct rtable *rt = skb_rtable(skb); 1567 unsigned long now; 1568 int code; 1569 1570 switch (rt->u.dst.error) { 1571 case EINVAL: 1572 default: 1573 goto out; 1574 case EHOSTUNREACH: 1575 code = ICMP_HOST_UNREACH; 1576 break; 1577 case ENETUNREACH: 1578 code = ICMP_NET_UNREACH; 1579 IP_INC_STATS_BH(dev_net(rt->u.dst.dev), 1580 IPSTATS_MIB_INNOROUTES); 1581 break; 1582 case EACCES: 1583 code = ICMP_PKT_FILTERED; 1584 break; 1585 } 1586 1587 now = jiffies; 1588 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last; 1589 if (rt->u.dst.rate_tokens > ip_rt_error_burst) 1590 rt->u.dst.rate_tokens = ip_rt_error_burst; 1591 rt->u.dst.rate_last = now; 1592 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) { 1593 rt->u.dst.rate_tokens -= ip_rt_error_cost; 1594 icmp_send(skb, ICMP_DEST_UNREACH, code, 0); 1595 } 1596 1597 out: kfree_skb(skb); 1598 return 0; 1599 } 1600 1601 /* 1602 * The last two values are not from the RFC but 1603 * are needed for AMPRnet AX.25 paths. 1604 */ 1605 1606 static const unsigned short mtu_plateau[] = 1607 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 }; 1608 1609 static inline unsigned short guess_mtu(unsigned short old_mtu) 1610 { 1611 int i; 1612 1613 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++) 1614 if (old_mtu > mtu_plateau[i]) 1615 return mtu_plateau[i]; 1616 return 68; 1617 } 1618 1619 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph, 1620 unsigned short new_mtu, 1621 struct net_device *dev) 1622 { 1623 int i, k; 1624 unsigned short old_mtu = ntohs(iph->tot_len); 1625 struct rtable *rth; 1626 int ikeys[2] = { dev->ifindex, 0 }; 1627 __be32 skeys[2] = { iph->saddr, 0, }; 1628 __be32 daddr = iph->daddr; 1629 unsigned short est_mtu = 0; 1630 1631 if (ipv4_config.no_pmtu_disc) 1632 return 0; 1633 1634 for (k = 0; k < 2; k++) { 1635 for (i = 0; i < 2; i++) { 1636 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k], 1637 rt_genid(net)); 1638 1639 rcu_read_lock(); 1640 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 1641 rth = rcu_dereference(rth->u.dst.rt_next)) { 1642 unsigned short mtu = new_mtu; 1643 1644 if (rth->fl.fl4_dst != daddr || 1645 rth->fl.fl4_src != skeys[i] || 1646 rth->rt_dst != daddr || 1647 rth->rt_src != iph->saddr || 1648 rth->fl.oif != ikeys[k] || 1649 rth->fl.iif != 0 || 1650 dst_metric_locked(&rth->u.dst, RTAX_MTU) || 1651 !net_eq(dev_net(rth->u.dst.dev), net) || 1652 rt_is_expired(rth)) 1653 continue; 1654 1655 if (new_mtu < 68 || new_mtu >= old_mtu) { 1656 1657 /* BSD 4.2 compatibility hack :-( */ 1658 if (mtu == 0 && 1659 old_mtu >= dst_mtu(&rth->u.dst) && 1660 old_mtu >= 68 + (iph->ihl << 2)) 1661 old_mtu -= iph->ihl << 2; 1662 1663 mtu = guess_mtu(old_mtu); 1664 } 1665 if (mtu <= dst_mtu(&rth->u.dst)) { 1666 if (mtu < dst_mtu(&rth->u.dst)) { 1667 dst_confirm(&rth->u.dst); 1668 if (mtu < ip_rt_min_pmtu) { 1669 mtu = ip_rt_min_pmtu; 1670 rth->u.dst.metrics[RTAX_LOCK-1] |= 1671 (1 << RTAX_MTU); 1672 } 1673 rth->u.dst.metrics[RTAX_MTU-1] = mtu; 1674 dst_set_expires(&rth->u.dst, 1675 ip_rt_mtu_expires); 1676 } 1677 est_mtu = mtu; 1678 } 1679 } 1680 rcu_read_unlock(); 1681 } 1682 } 1683 return est_mtu ? : new_mtu; 1684 } 1685 1686 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 1687 { 1688 if (dst_mtu(dst) > mtu && mtu >= 68 && 1689 !(dst_metric_locked(dst, RTAX_MTU))) { 1690 if (mtu < ip_rt_min_pmtu) { 1691 mtu = ip_rt_min_pmtu; 1692 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU); 1693 } 1694 dst->metrics[RTAX_MTU-1] = mtu; 1695 dst_set_expires(dst, ip_rt_mtu_expires); 1696 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst); 1697 } 1698 } 1699 1700 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) 1701 { 1702 return NULL; 1703 } 1704 1705 static void ipv4_dst_destroy(struct dst_entry *dst) 1706 { 1707 struct rtable *rt = (struct rtable *) dst; 1708 struct inet_peer *peer = rt->peer; 1709 struct in_device *idev = rt->idev; 1710 1711 if (peer) { 1712 rt->peer = NULL; 1713 inet_putpeer(peer); 1714 } 1715 1716 if (idev) { 1717 rt->idev = NULL; 1718 in_dev_put(idev); 1719 } 1720 } 1721 1722 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 1723 int how) 1724 { 1725 struct rtable *rt = (struct rtable *) dst; 1726 struct in_device *idev = rt->idev; 1727 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) { 1728 struct in_device *loopback_idev = 1729 in_dev_get(dev_net(dev)->loopback_dev); 1730 if (loopback_idev) { 1731 rt->idev = loopback_idev; 1732 in_dev_put(idev); 1733 } 1734 } 1735 } 1736 1737 static void ipv4_link_failure(struct sk_buff *skb) 1738 { 1739 struct rtable *rt; 1740 1741 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); 1742 1743 rt = skb_rtable(skb); 1744 if (rt) 1745 dst_set_expires(&rt->u.dst, 0); 1746 } 1747 1748 static int ip_rt_bug(struct sk_buff *skb) 1749 { 1750 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n", 1751 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, 1752 skb->dev ? skb->dev->name : "?"); 1753 kfree_skb(skb); 1754 return 0; 1755 } 1756 1757 /* 1758 We do not cache source address of outgoing interface, 1759 because it is used only by IP RR, TS and SRR options, 1760 so that it out of fast path. 1761 1762 BTW remember: "addr" is allowed to be not aligned 1763 in IP options! 1764 */ 1765 1766 void ip_rt_get_source(u8 *addr, struct rtable *rt) 1767 { 1768 __be32 src; 1769 struct fib_result res; 1770 1771 if (rt->fl.iif == 0) 1772 src = rt->rt_src; 1773 else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) { 1774 src = FIB_RES_PREFSRC(res); 1775 fib_res_put(&res); 1776 } else 1777 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway, 1778 RT_SCOPE_UNIVERSE); 1779 memcpy(addr, &src, 4); 1780 } 1781 1782 #ifdef CONFIG_NET_CLS_ROUTE 1783 static void set_class_tag(struct rtable *rt, u32 tag) 1784 { 1785 if (!(rt->u.dst.tclassid & 0xFFFF)) 1786 rt->u.dst.tclassid |= tag & 0xFFFF; 1787 if (!(rt->u.dst.tclassid & 0xFFFF0000)) 1788 rt->u.dst.tclassid |= tag & 0xFFFF0000; 1789 } 1790 #endif 1791 1792 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag) 1793 { 1794 struct fib_info *fi = res->fi; 1795 1796 if (fi) { 1797 if (FIB_RES_GW(*res) && 1798 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) 1799 rt->rt_gateway = FIB_RES_GW(*res); 1800 memcpy(rt->u.dst.metrics, fi->fib_metrics, 1801 sizeof(rt->u.dst.metrics)); 1802 if (fi->fib_mtu == 0) { 1803 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu; 1804 if (dst_metric_locked(&rt->u.dst, RTAX_MTU) && 1805 rt->rt_gateway != rt->rt_dst && 1806 rt->u.dst.dev->mtu > 576) 1807 rt->u.dst.metrics[RTAX_MTU-1] = 576; 1808 } 1809 #ifdef CONFIG_NET_CLS_ROUTE 1810 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid; 1811 #endif 1812 } else 1813 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu; 1814 1815 if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0) 1816 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl; 1817 if (dst_mtu(&rt->u.dst) > IP_MAX_MTU) 1818 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU; 1819 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0) 1820 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40, 1821 ip_rt_min_advmss); 1822 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) > 65535 - 40) 1823 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40; 1824 1825 #ifdef CONFIG_NET_CLS_ROUTE 1826 #ifdef CONFIG_IP_MULTIPLE_TABLES 1827 set_class_tag(rt, fib_rules_tclass(res)); 1828 #endif 1829 set_class_tag(rt, itag); 1830 #endif 1831 rt->rt_type = res->type; 1832 } 1833 1834 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, 1835 u8 tos, struct net_device *dev, int our) 1836 { 1837 unsigned hash; 1838 struct rtable *rth; 1839 __be32 spec_dst; 1840 struct in_device *in_dev = in_dev_get(dev); 1841 u32 itag = 0; 1842 1843 /* Primary sanity checks. */ 1844 1845 if (in_dev == NULL) 1846 return -EINVAL; 1847 1848 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 1849 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP)) 1850 goto e_inval; 1851 1852 if (ipv4_is_zeronet(saddr)) { 1853 if (!ipv4_is_local_multicast(daddr)) 1854 goto e_inval; 1855 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 1856 } else if (fib_validate_source(saddr, 0, tos, 0, 1857 dev, &spec_dst, &itag) < 0) 1858 goto e_inval; 1859 1860 rth = dst_alloc(&ipv4_dst_ops); 1861 if (!rth) 1862 goto e_nobufs; 1863 1864 rth->u.dst.output= ip_rt_bug; 1865 1866 atomic_set(&rth->u.dst.__refcnt, 1); 1867 rth->u.dst.flags= DST_HOST; 1868 if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) 1869 rth->u.dst.flags |= DST_NOPOLICY; 1870 rth->fl.fl4_dst = daddr; 1871 rth->rt_dst = daddr; 1872 rth->fl.fl4_tos = tos; 1873 rth->fl.mark = skb->mark; 1874 rth->fl.fl4_src = saddr; 1875 rth->rt_src = saddr; 1876 #ifdef CONFIG_NET_CLS_ROUTE 1877 rth->u.dst.tclassid = itag; 1878 #endif 1879 rth->rt_iif = 1880 rth->fl.iif = dev->ifindex; 1881 rth->u.dst.dev = init_net.loopback_dev; 1882 dev_hold(rth->u.dst.dev); 1883 rth->idev = in_dev_get(rth->u.dst.dev); 1884 rth->fl.oif = 0; 1885 rth->rt_gateway = daddr; 1886 rth->rt_spec_dst= spec_dst; 1887 rth->rt_genid = rt_genid(dev_net(dev)); 1888 rth->rt_flags = RTCF_MULTICAST; 1889 rth->rt_type = RTN_MULTICAST; 1890 if (our) { 1891 rth->u.dst.input= ip_local_deliver; 1892 rth->rt_flags |= RTCF_LOCAL; 1893 } 1894 1895 #ifdef CONFIG_IP_MROUTE 1896 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev)) 1897 rth->u.dst.input = ip_mr_input; 1898 #endif 1899 RT_CACHE_STAT_INC(in_slow_mc); 1900 1901 in_dev_put(in_dev); 1902 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev))); 1903 return rt_intern_hash(hash, rth, NULL, skb); 1904 1905 e_nobufs: 1906 in_dev_put(in_dev); 1907 return -ENOBUFS; 1908 1909 e_inval: 1910 in_dev_put(in_dev); 1911 return -EINVAL; 1912 } 1913 1914 1915 static void ip_handle_martian_source(struct net_device *dev, 1916 struct in_device *in_dev, 1917 struct sk_buff *skb, 1918 __be32 daddr, 1919 __be32 saddr) 1920 { 1921 RT_CACHE_STAT_INC(in_martian_src); 1922 #ifdef CONFIG_IP_ROUTE_VERBOSE 1923 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) { 1924 /* 1925 * RFC1812 recommendation, if source is martian, 1926 * the only hint is MAC header. 1927 */ 1928 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n", 1929 &daddr, &saddr, dev->name); 1930 if (dev->hard_header_len && skb_mac_header_was_set(skb)) { 1931 int i; 1932 const unsigned char *p = skb_mac_header(skb); 1933 printk(KERN_WARNING "ll header: "); 1934 for (i = 0; i < dev->hard_header_len; i++, p++) { 1935 printk("%02x", *p); 1936 if (i < (dev->hard_header_len - 1)) 1937 printk(":"); 1938 } 1939 printk("\n"); 1940 } 1941 } 1942 #endif 1943 } 1944 1945 static int __mkroute_input(struct sk_buff *skb, 1946 struct fib_result *res, 1947 struct in_device *in_dev, 1948 __be32 daddr, __be32 saddr, u32 tos, 1949 struct rtable **result) 1950 { 1951 1952 struct rtable *rth; 1953 int err; 1954 struct in_device *out_dev; 1955 unsigned flags = 0; 1956 __be32 spec_dst; 1957 u32 itag; 1958 1959 /* get a working reference to the output device */ 1960 out_dev = in_dev_get(FIB_RES_DEV(*res)); 1961 if (out_dev == NULL) { 1962 if (net_ratelimit()) 1963 printk(KERN_CRIT "Bug in ip_route_input" \ 1964 "_slow(). Please, report\n"); 1965 return -EINVAL; 1966 } 1967 1968 1969 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res), 1970 in_dev->dev, &spec_dst, &itag); 1971 if (err < 0) { 1972 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr, 1973 saddr); 1974 1975 err = -EINVAL; 1976 goto cleanup; 1977 } 1978 1979 if (err) 1980 flags |= RTCF_DIRECTSRC; 1981 1982 if (out_dev == in_dev && err && 1983 (IN_DEV_SHARED_MEDIA(out_dev) || 1984 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) 1985 flags |= RTCF_DOREDIRECT; 1986 1987 if (skb->protocol != htons(ETH_P_IP)) { 1988 /* Not IP (i.e. ARP). Do not create route, if it is 1989 * invalid for proxy arp. DNAT routes are always valid. 1990 */ 1991 if (out_dev == in_dev) { 1992 err = -EINVAL; 1993 goto cleanup; 1994 } 1995 } 1996 1997 1998 rth = dst_alloc(&ipv4_dst_ops); 1999 if (!rth) { 2000 err = -ENOBUFS; 2001 goto cleanup; 2002 } 2003 2004 atomic_set(&rth->u.dst.__refcnt, 1); 2005 rth->u.dst.flags= DST_HOST; 2006 if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) 2007 rth->u.dst.flags |= DST_NOPOLICY; 2008 if (IN_DEV_CONF_GET(out_dev, NOXFRM)) 2009 rth->u.dst.flags |= DST_NOXFRM; 2010 rth->fl.fl4_dst = daddr; 2011 rth->rt_dst = daddr; 2012 rth->fl.fl4_tos = tos; 2013 rth->fl.mark = skb->mark; 2014 rth->fl.fl4_src = saddr; 2015 rth->rt_src = saddr; 2016 rth->rt_gateway = daddr; 2017 rth->rt_iif = 2018 rth->fl.iif = in_dev->dev->ifindex; 2019 rth->u.dst.dev = (out_dev)->dev; 2020 dev_hold(rth->u.dst.dev); 2021 rth->idev = in_dev_get(rth->u.dst.dev); 2022 rth->fl.oif = 0; 2023 rth->rt_spec_dst= spec_dst; 2024 2025 rth->u.dst.input = ip_forward; 2026 rth->u.dst.output = ip_output; 2027 rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev)); 2028 2029 rt_set_nexthop(rth, res, itag); 2030 2031 rth->rt_flags = flags; 2032 2033 *result = rth; 2034 err = 0; 2035 cleanup: 2036 /* release the working reference to the output device */ 2037 in_dev_put(out_dev); 2038 return err; 2039 } 2040 2041 static int ip_mkroute_input(struct sk_buff *skb, 2042 struct fib_result *res, 2043 const struct flowi *fl, 2044 struct in_device *in_dev, 2045 __be32 daddr, __be32 saddr, u32 tos) 2046 { 2047 struct rtable* rth = NULL; 2048 int err; 2049 unsigned hash; 2050 2051 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2052 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0) 2053 fib_select_multipath(fl, res); 2054 #endif 2055 2056 /* create a routing cache entry */ 2057 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); 2058 if (err) 2059 return err; 2060 2061 /* put it into the cache */ 2062 hash = rt_hash(daddr, saddr, fl->iif, 2063 rt_genid(dev_net(rth->u.dst.dev))); 2064 return rt_intern_hash(hash, rth, NULL, skb); 2065 } 2066 2067 /* 2068 * NOTE. We drop all the packets that has local source 2069 * addresses, because every properly looped back packet 2070 * must have correct destination already attached by output routine. 2071 * 2072 * Such approach solves two big problems: 2073 * 1. Not simplex devices are handled properly. 2074 * 2. IP spoofing attempts are filtered with 100% of guarantee. 2075 */ 2076 2077 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2078 u8 tos, struct net_device *dev) 2079 { 2080 struct fib_result res; 2081 struct in_device *in_dev = in_dev_get(dev); 2082 struct flowi fl = { .nl_u = { .ip4_u = 2083 { .daddr = daddr, 2084 .saddr = saddr, 2085 .tos = tos, 2086 .scope = RT_SCOPE_UNIVERSE, 2087 } }, 2088 .mark = skb->mark, 2089 .iif = dev->ifindex }; 2090 unsigned flags = 0; 2091 u32 itag = 0; 2092 struct rtable * rth; 2093 unsigned hash; 2094 __be32 spec_dst; 2095 int err = -EINVAL; 2096 int free_res = 0; 2097 struct net * net = dev_net(dev); 2098 2099 /* IP on this device is disabled. */ 2100 2101 if (!in_dev) 2102 goto out; 2103 2104 /* Check for the most weird martians, which can be not detected 2105 by fib_lookup. 2106 */ 2107 2108 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) || 2109 ipv4_is_loopback(saddr)) 2110 goto martian_source; 2111 2112 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0)) 2113 goto brd_input; 2114 2115 /* Accept zero addresses only to limited broadcast; 2116 * I even do not know to fix it or not. Waiting for complains :-) 2117 */ 2118 if (ipv4_is_zeronet(saddr)) 2119 goto martian_source; 2120 2121 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) || 2122 ipv4_is_loopback(daddr)) 2123 goto martian_destination; 2124 2125 /* 2126 * Now we are ready to route packet. 2127 */ 2128 if ((err = fib_lookup(net, &fl, &res)) != 0) { 2129 if (!IN_DEV_FORWARD(in_dev)) 2130 goto e_hostunreach; 2131 goto no_route; 2132 } 2133 free_res = 1; 2134 2135 RT_CACHE_STAT_INC(in_slow_tot); 2136 2137 if (res.type == RTN_BROADCAST) 2138 goto brd_input; 2139 2140 if (res.type == RTN_LOCAL) { 2141 int result; 2142 result = fib_validate_source(saddr, daddr, tos, 2143 net->loopback_dev->ifindex, 2144 dev, &spec_dst, &itag); 2145 if (result < 0) 2146 goto martian_source; 2147 if (result) 2148 flags |= RTCF_DIRECTSRC; 2149 spec_dst = daddr; 2150 goto local_input; 2151 } 2152 2153 if (!IN_DEV_FORWARD(in_dev)) 2154 goto e_hostunreach; 2155 if (res.type != RTN_UNICAST) 2156 goto martian_destination; 2157 2158 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos); 2159 done: 2160 in_dev_put(in_dev); 2161 if (free_res) 2162 fib_res_put(&res); 2163 out: return err; 2164 2165 brd_input: 2166 if (skb->protocol != htons(ETH_P_IP)) 2167 goto e_inval; 2168 2169 if (ipv4_is_zeronet(saddr)) 2170 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK); 2171 else { 2172 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst, 2173 &itag); 2174 if (err < 0) 2175 goto martian_source; 2176 if (err) 2177 flags |= RTCF_DIRECTSRC; 2178 } 2179 flags |= RTCF_BROADCAST; 2180 res.type = RTN_BROADCAST; 2181 RT_CACHE_STAT_INC(in_brd); 2182 2183 local_input: 2184 rth = dst_alloc(&ipv4_dst_ops); 2185 if (!rth) 2186 goto e_nobufs; 2187 2188 rth->u.dst.output= ip_rt_bug; 2189 rth->rt_genid = rt_genid(net); 2190 2191 atomic_set(&rth->u.dst.__refcnt, 1); 2192 rth->u.dst.flags= DST_HOST; 2193 if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) 2194 rth->u.dst.flags |= DST_NOPOLICY; 2195 rth->fl.fl4_dst = daddr; 2196 rth->rt_dst = daddr; 2197 rth->fl.fl4_tos = tos; 2198 rth->fl.mark = skb->mark; 2199 rth->fl.fl4_src = saddr; 2200 rth->rt_src = saddr; 2201 #ifdef CONFIG_NET_CLS_ROUTE 2202 rth->u.dst.tclassid = itag; 2203 #endif 2204 rth->rt_iif = 2205 rth->fl.iif = dev->ifindex; 2206 rth->u.dst.dev = net->loopback_dev; 2207 dev_hold(rth->u.dst.dev); 2208 rth->idev = in_dev_get(rth->u.dst.dev); 2209 rth->rt_gateway = daddr; 2210 rth->rt_spec_dst= spec_dst; 2211 rth->u.dst.input= ip_local_deliver; 2212 rth->rt_flags = flags|RTCF_LOCAL; 2213 if (res.type == RTN_UNREACHABLE) { 2214 rth->u.dst.input= ip_error; 2215 rth->u.dst.error= -err; 2216 rth->rt_flags &= ~RTCF_LOCAL; 2217 } 2218 rth->rt_type = res.type; 2219 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net)); 2220 err = rt_intern_hash(hash, rth, NULL, skb); 2221 goto done; 2222 2223 no_route: 2224 RT_CACHE_STAT_INC(in_no_route); 2225 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); 2226 res.type = RTN_UNREACHABLE; 2227 if (err == -ESRCH) 2228 err = -ENETUNREACH; 2229 goto local_input; 2230 2231 /* 2232 * Do not cache martian addresses: they should be logged (RFC1812) 2233 */ 2234 martian_destination: 2235 RT_CACHE_STAT_INC(in_martian_dst); 2236 #ifdef CONFIG_IP_ROUTE_VERBOSE 2237 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) 2238 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n", 2239 &daddr, &saddr, dev->name); 2240 #endif 2241 2242 e_hostunreach: 2243 err = -EHOSTUNREACH; 2244 goto done; 2245 2246 e_inval: 2247 err = -EINVAL; 2248 goto done; 2249 2250 e_nobufs: 2251 err = -ENOBUFS; 2252 goto done; 2253 2254 martian_source: 2255 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); 2256 goto e_inval; 2257 } 2258 2259 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr, 2260 u8 tos, struct net_device *dev) 2261 { 2262 struct rtable * rth; 2263 unsigned hash; 2264 int iif = dev->ifindex; 2265 struct net *net; 2266 2267 net = dev_net(dev); 2268 2269 if (!rt_caching(net)) 2270 goto skip_cache; 2271 2272 tos &= IPTOS_RT_MASK; 2273 hash = rt_hash(daddr, saddr, iif, rt_genid(net)); 2274 2275 rcu_read_lock(); 2276 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 2277 rth = rcu_dereference(rth->u.dst.rt_next)) { 2278 if (((rth->fl.fl4_dst ^ daddr) | 2279 (rth->fl.fl4_src ^ saddr) | 2280 (rth->fl.iif ^ iif) | 2281 rth->fl.oif | 2282 (rth->fl.fl4_tos ^ tos)) == 0 && 2283 rth->fl.mark == skb->mark && 2284 net_eq(dev_net(rth->u.dst.dev), net) && 2285 !rt_is_expired(rth)) { 2286 dst_use(&rth->u.dst, jiffies); 2287 RT_CACHE_STAT_INC(in_hit); 2288 rcu_read_unlock(); 2289 skb_dst_set(skb, &rth->u.dst); 2290 return 0; 2291 } 2292 RT_CACHE_STAT_INC(in_hlist_search); 2293 } 2294 rcu_read_unlock(); 2295 2296 skip_cache: 2297 /* Multicast recognition logic is moved from route cache to here. 2298 The problem was that too many Ethernet cards have broken/missing 2299 hardware multicast filters :-( As result the host on multicasting 2300 network acquires a lot of useless route cache entries, sort of 2301 SDR messages from all the world. Now we try to get rid of them. 2302 Really, provided software IP multicast filter is organized 2303 reasonably (at least, hashed), it does not result in a slowdown 2304 comparing with route cache reject entries. 2305 Note, that multicast routers are not affected, because 2306 route cache entry is created eventually. 2307 */ 2308 if (ipv4_is_multicast(daddr)) { 2309 struct in_device *in_dev; 2310 2311 rcu_read_lock(); 2312 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) { 2313 int our = ip_check_mc(in_dev, daddr, saddr, 2314 ip_hdr(skb)->protocol); 2315 if (our 2316 #ifdef CONFIG_IP_MROUTE 2317 || (!ipv4_is_local_multicast(daddr) && 2318 IN_DEV_MFORWARD(in_dev)) 2319 #endif 2320 ) { 2321 rcu_read_unlock(); 2322 return ip_route_input_mc(skb, daddr, saddr, 2323 tos, dev, our); 2324 } 2325 } 2326 rcu_read_unlock(); 2327 return -EINVAL; 2328 } 2329 return ip_route_input_slow(skb, daddr, saddr, tos, dev); 2330 } 2331 2332 static int __mkroute_output(struct rtable **result, 2333 struct fib_result *res, 2334 const struct flowi *fl, 2335 const struct flowi *oldflp, 2336 struct net_device *dev_out, 2337 unsigned flags) 2338 { 2339 struct rtable *rth; 2340 struct in_device *in_dev; 2341 u32 tos = RT_FL_TOS(oldflp); 2342 int err = 0; 2343 2344 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK)) 2345 return -EINVAL; 2346 2347 if (fl->fl4_dst == htonl(0xFFFFFFFF)) 2348 res->type = RTN_BROADCAST; 2349 else if (ipv4_is_multicast(fl->fl4_dst)) 2350 res->type = RTN_MULTICAST; 2351 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst)) 2352 return -EINVAL; 2353 2354 if (dev_out->flags & IFF_LOOPBACK) 2355 flags |= RTCF_LOCAL; 2356 2357 /* get work reference to inet device */ 2358 in_dev = in_dev_get(dev_out); 2359 if (!in_dev) 2360 return -EINVAL; 2361 2362 if (res->type == RTN_BROADCAST) { 2363 flags |= RTCF_BROADCAST | RTCF_LOCAL; 2364 if (res->fi) { 2365 fib_info_put(res->fi); 2366 res->fi = NULL; 2367 } 2368 } else if (res->type == RTN_MULTICAST) { 2369 flags |= RTCF_MULTICAST|RTCF_LOCAL; 2370 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src, 2371 oldflp->proto)) 2372 flags &= ~RTCF_LOCAL; 2373 /* If multicast route do not exist use 2374 default one, but do not gateway in this case. 2375 Yes, it is hack. 2376 */ 2377 if (res->fi && res->prefixlen < 4) { 2378 fib_info_put(res->fi); 2379 res->fi = NULL; 2380 } 2381 } 2382 2383 2384 rth = dst_alloc(&ipv4_dst_ops); 2385 if (!rth) { 2386 err = -ENOBUFS; 2387 goto cleanup; 2388 } 2389 2390 atomic_set(&rth->u.dst.__refcnt, 1); 2391 rth->u.dst.flags= DST_HOST; 2392 if (IN_DEV_CONF_GET(in_dev, NOXFRM)) 2393 rth->u.dst.flags |= DST_NOXFRM; 2394 if (IN_DEV_CONF_GET(in_dev, NOPOLICY)) 2395 rth->u.dst.flags |= DST_NOPOLICY; 2396 2397 rth->fl.fl4_dst = oldflp->fl4_dst; 2398 rth->fl.fl4_tos = tos; 2399 rth->fl.fl4_src = oldflp->fl4_src; 2400 rth->fl.oif = oldflp->oif; 2401 rth->fl.mark = oldflp->mark; 2402 rth->rt_dst = fl->fl4_dst; 2403 rth->rt_src = fl->fl4_src; 2404 rth->rt_iif = oldflp->oif ? : dev_out->ifindex; 2405 /* get references to the devices that are to be hold by the routing 2406 cache entry */ 2407 rth->u.dst.dev = dev_out; 2408 dev_hold(dev_out); 2409 rth->idev = in_dev_get(dev_out); 2410 rth->rt_gateway = fl->fl4_dst; 2411 rth->rt_spec_dst= fl->fl4_src; 2412 2413 rth->u.dst.output=ip_output; 2414 rth->rt_genid = rt_genid(dev_net(dev_out)); 2415 2416 RT_CACHE_STAT_INC(out_slow_tot); 2417 2418 if (flags & RTCF_LOCAL) { 2419 rth->u.dst.input = ip_local_deliver; 2420 rth->rt_spec_dst = fl->fl4_dst; 2421 } 2422 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { 2423 rth->rt_spec_dst = fl->fl4_src; 2424 if (flags & RTCF_LOCAL && 2425 !(dev_out->flags & IFF_LOOPBACK)) { 2426 rth->u.dst.output = ip_mc_output; 2427 RT_CACHE_STAT_INC(out_slow_mc); 2428 } 2429 #ifdef CONFIG_IP_MROUTE 2430 if (res->type == RTN_MULTICAST) { 2431 if (IN_DEV_MFORWARD(in_dev) && 2432 !ipv4_is_local_multicast(oldflp->fl4_dst)) { 2433 rth->u.dst.input = ip_mr_input; 2434 rth->u.dst.output = ip_mc_output; 2435 } 2436 } 2437 #endif 2438 } 2439 2440 rt_set_nexthop(rth, res, 0); 2441 2442 rth->rt_flags = flags; 2443 2444 *result = rth; 2445 cleanup: 2446 /* release work reference to inet device */ 2447 in_dev_put(in_dev); 2448 2449 return err; 2450 } 2451 2452 static int ip_mkroute_output(struct rtable **rp, 2453 struct fib_result *res, 2454 const struct flowi *fl, 2455 const struct flowi *oldflp, 2456 struct net_device *dev_out, 2457 unsigned flags) 2458 { 2459 struct rtable *rth = NULL; 2460 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags); 2461 unsigned hash; 2462 if (err == 0) { 2463 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif, 2464 rt_genid(dev_net(dev_out))); 2465 err = rt_intern_hash(hash, rth, rp, NULL); 2466 } 2467 2468 return err; 2469 } 2470 2471 /* 2472 * Major route resolver routine. 2473 */ 2474 2475 static int ip_route_output_slow(struct net *net, struct rtable **rp, 2476 const struct flowi *oldflp) 2477 { 2478 u32 tos = RT_FL_TOS(oldflp); 2479 struct flowi fl = { .nl_u = { .ip4_u = 2480 { .daddr = oldflp->fl4_dst, 2481 .saddr = oldflp->fl4_src, 2482 .tos = tos & IPTOS_RT_MASK, 2483 .scope = ((tos & RTO_ONLINK) ? 2484 RT_SCOPE_LINK : 2485 RT_SCOPE_UNIVERSE), 2486 } }, 2487 .mark = oldflp->mark, 2488 .iif = net->loopback_dev->ifindex, 2489 .oif = oldflp->oif }; 2490 struct fib_result res; 2491 unsigned flags = 0; 2492 struct net_device *dev_out = NULL; 2493 int free_res = 0; 2494 int err; 2495 2496 2497 res.fi = NULL; 2498 #ifdef CONFIG_IP_MULTIPLE_TABLES 2499 res.r = NULL; 2500 #endif 2501 2502 if (oldflp->fl4_src) { 2503 err = -EINVAL; 2504 if (ipv4_is_multicast(oldflp->fl4_src) || 2505 ipv4_is_lbcast(oldflp->fl4_src) || 2506 ipv4_is_zeronet(oldflp->fl4_src)) 2507 goto out; 2508 2509 /* I removed check for oif == dev_out->oif here. 2510 It was wrong for two reasons: 2511 1. ip_dev_find(net, saddr) can return wrong iface, if saddr 2512 is assigned to multiple interfaces. 2513 2. Moreover, we are allowed to send packets with saddr 2514 of another iface. --ANK 2515 */ 2516 2517 if (oldflp->oif == 0 2518 && (ipv4_is_multicast(oldflp->fl4_dst) || 2519 oldflp->fl4_dst == htonl(0xFFFFFFFF))) { 2520 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2521 dev_out = ip_dev_find(net, oldflp->fl4_src); 2522 if (dev_out == NULL) 2523 goto out; 2524 2525 /* Special hack: user can direct multicasts 2526 and limited broadcast via necessary interface 2527 without fiddling with IP_MULTICAST_IF or IP_PKTINFO. 2528 This hack is not just for fun, it allows 2529 vic,vat and friends to work. 2530 They bind socket to loopback, set ttl to zero 2531 and expect that it will work. 2532 From the viewpoint of routing cache they are broken, 2533 because we are not allowed to build multicast path 2534 with loopback source addr (look, routing cache 2535 cannot know, that ttl is zero, so that packet 2536 will not leave this host and route is valid). 2537 Luckily, this hack is good workaround. 2538 */ 2539 2540 fl.oif = dev_out->ifindex; 2541 goto make_route; 2542 } 2543 2544 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) { 2545 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */ 2546 dev_out = ip_dev_find(net, oldflp->fl4_src); 2547 if (dev_out == NULL) 2548 goto out; 2549 dev_put(dev_out); 2550 dev_out = NULL; 2551 } 2552 } 2553 2554 2555 if (oldflp->oif) { 2556 dev_out = dev_get_by_index(net, oldflp->oif); 2557 err = -ENODEV; 2558 if (dev_out == NULL) 2559 goto out; 2560 2561 /* RACE: Check return value of inet_select_addr instead. */ 2562 if (__in_dev_get_rtnl(dev_out) == NULL) { 2563 dev_put(dev_out); 2564 goto out; /* Wrong error code */ 2565 } 2566 2567 if (ipv4_is_local_multicast(oldflp->fl4_dst) || 2568 oldflp->fl4_dst == htonl(0xFFFFFFFF)) { 2569 if (!fl.fl4_src) 2570 fl.fl4_src = inet_select_addr(dev_out, 0, 2571 RT_SCOPE_LINK); 2572 goto make_route; 2573 } 2574 if (!fl.fl4_src) { 2575 if (ipv4_is_multicast(oldflp->fl4_dst)) 2576 fl.fl4_src = inet_select_addr(dev_out, 0, 2577 fl.fl4_scope); 2578 else if (!oldflp->fl4_dst) 2579 fl.fl4_src = inet_select_addr(dev_out, 0, 2580 RT_SCOPE_HOST); 2581 } 2582 } 2583 2584 if (!fl.fl4_dst) { 2585 fl.fl4_dst = fl.fl4_src; 2586 if (!fl.fl4_dst) 2587 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK); 2588 if (dev_out) 2589 dev_put(dev_out); 2590 dev_out = net->loopback_dev; 2591 dev_hold(dev_out); 2592 fl.oif = net->loopback_dev->ifindex; 2593 res.type = RTN_LOCAL; 2594 flags |= RTCF_LOCAL; 2595 goto make_route; 2596 } 2597 2598 if (fib_lookup(net, &fl, &res)) { 2599 res.fi = NULL; 2600 if (oldflp->oif) { 2601 /* Apparently, routing tables are wrong. Assume, 2602 that the destination is on link. 2603 2604 WHY? DW. 2605 Because we are allowed to send to iface 2606 even if it has NO routes and NO assigned 2607 addresses. When oif is specified, routing 2608 tables are looked up with only one purpose: 2609 to catch if destination is gatewayed, rather than 2610 direct. Moreover, if MSG_DONTROUTE is set, 2611 we send packet, ignoring both routing tables 2612 and ifaddr state. --ANK 2613 2614 2615 We could make it even if oif is unknown, 2616 likely IPv6, but we do not. 2617 */ 2618 2619 if (fl.fl4_src == 0) 2620 fl.fl4_src = inet_select_addr(dev_out, 0, 2621 RT_SCOPE_LINK); 2622 res.type = RTN_UNICAST; 2623 goto make_route; 2624 } 2625 if (dev_out) 2626 dev_put(dev_out); 2627 err = -ENETUNREACH; 2628 goto out; 2629 } 2630 free_res = 1; 2631 2632 if (res.type == RTN_LOCAL) { 2633 if (!fl.fl4_src) 2634 fl.fl4_src = fl.fl4_dst; 2635 if (dev_out) 2636 dev_put(dev_out); 2637 dev_out = net->loopback_dev; 2638 dev_hold(dev_out); 2639 fl.oif = dev_out->ifindex; 2640 if (res.fi) 2641 fib_info_put(res.fi); 2642 res.fi = NULL; 2643 flags |= RTCF_LOCAL; 2644 goto make_route; 2645 } 2646 2647 #ifdef CONFIG_IP_ROUTE_MULTIPATH 2648 if (res.fi->fib_nhs > 1 && fl.oif == 0) 2649 fib_select_multipath(&fl, &res); 2650 else 2651 #endif 2652 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif) 2653 fib_select_default(net, &fl, &res); 2654 2655 if (!fl.fl4_src) 2656 fl.fl4_src = FIB_RES_PREFSRC(res); 2657 2658 if (dev_out) 2659 dev_put(dev_out); 2660 dev_out = FIB_RES_DEV(res); 2661 dev_hold(dev_out); 2662 fl.oif = dev_out->ifindex; 2663 2664 2665 make_route: 2666 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags); 2667 2668 2669 if (free_res) 2670 fib_res_put(&res); 2671 if (dev_out) 2672 dev_put(dev_out); 2673 out: return err; 2674 } 2675 2676 int __ip_route_output_key(struct net *net, struct rtable **rp, 2677 const struct flowi *flp) 2678 { 2679 unsigned hash; 2680 struct rtable *rth; 2681 2682 if (!rt_caching(net)) 2683 goto slow_output; 2684 2685 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net)); 2686 2687 rcu_read_lock_bh(); 2688 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth; 2689 rth = rcu_dereference(rth->u.dst.rt_next)) { 2690 if (rth->fl.fl4_dst == flp->fl4_dst && 2691 rth->fl.fl4_src == flp->fl4_src && 2692 rth->fl.iif == 0 && 2693 rth->fl.oif == flp->oif && 2694 rth->fl.mark == flp->mark && 2695 !((rth->fl.fl4_tos ^ flp->fl4_tos) & 2696 (IPTOS_RT_MASK | RTO_ONLINK)) && 2697 net_eq(dev_net(rth->u.dst.dev), net) && 2698 !rt_is_expired(rth)) { 2699 dst_use(&rth->u.dst, jiffies); 2700 RT_CACHE_STAT_INC(out_hit); 2701 rcu_read_unlock_bh(); 2702 *rp = rth; 2703 return 0; 2704 } 2705 RT_CACHE_STAT_INC(out_hlist_search); 2706 } 2707 rcu_read_unlock_bh(); 2708 2709 slow_output: 2710 return ip_route_output_slow(net, rp, flp); 2711 } 2712 2713 EXPORT_SYMBOL_GPL(__ip_route_output_key); 2714 2715 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) 2716 { 2717 } 2718 2719 static struct dst_ops ipv4_dst_blackhole_ops = { 2720 .family = AF_INET, 2721 .protocol = cpu_to_be16(ETH_P_IP), 2722 .destroy = ipv4_dst_destroy, 2723 .check = ipv4_dst_check, 2724 .update_pmtu = ipv4_rt_blackhole_update_pmtu, 2725 .entries = ATOMIC_INIT(0), 2726 }; 2727 2728 2729 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp) 2730 { 2731 struct rtable *ort = *rp; 2732 struct rtable *rt = (struct rtable *) 2733 dst_alloc(&ipv4_dst_blackhole_ops); 2734 2735 if (rt) { 2736 struct dst_entry *new = &rt->u.dst; 2737 2738 atomic_set(&new->__refcnt, 1); 2739 new->__use = 1; 2740 new->input = dst_discard; 2741 new->output = dst_discard; 2742 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32)); 2743 2744 new->dev = ort->u.dst.dev; 2745 if (new->dev) 2746 dev_hold(new->dev); 2747 2748 rt->fl = ort->fl; 2749 2750 rt->idev = ort->idev; 2751 if (rt->idev) 2752 in_dev_hold(rt->idev); 2753 rt->rt_genid = rt_genid(net); 2754 rt->rt_flags = ort->rt_flags; 2755 rt->rt_type = ort->rt_type; 2756 rt->rt_dst = ort->rt_dst; 2757 rt->rt_src = ort->rt_src; 2758 rt->rt_iif = ort->rt_iif; 2759 rt->rt_gateway = ort->rt_gateway; 2760 rt->rt_spec_dst = ort->rt_spec_dst; 2761 rt->peer = ort->peer; 2762 if (rt->peer) 2763 atomic_inc(&rt->peer->refcnt); 2764 2765 dst_free(new); 2766 } 2767 2768 dst_release(&(*rp)->u.dst); 2769 *rp = rt; 2770 return (rt ? 0 : -ENOMEM); 2771 } 2772 2773 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp, 2774 struct sock *sk, int flags) 2775 { 2776 int err; 2777 2778 if ((err = __ip_route_output_key(net, rp, flp)) != 0) 2779 return err; 2780 2781 if (flp->proto) { 2782 if (!flp->fl4_src) 2783 flp->fl4_src = (*rp)->rt_src; 2784 if (!flp->fl4_dst) 2785 flp->fl4_dst = (*rp)->rt_dst; 2786 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk, 2787 flags ? XFRM_LOOKUP_WAIT : 0); 2788 if (err == -EREMOTE) 2789 err = ipv4_dst_blackhole(net, rp, flp); 2790 2791 return err; 2792 } 2793 2794 return 0; 2795 } 2796 2797 EXPORT_SYMBOL_GPL(ip_route_output_flow); 2798 2799 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp) 2800 { 2801 return ip_route_output_flow(net, rp, flp, NULL, 0); 2802 } 2803 2804 static int rt_fill_info(struct net *net, 2805 struct sk_buff *skb, u32 pid, u32 seq, int event, 2806 int nowait, unsigned int flags) 2807 { 2808 struct rtable *rt = skb_rtable(skb); 2809 struct rtmsg *r; 2810 struct nlmsghdr *nlh; 2811 long expires; 2812 u32 id = 0, ts = 0, tsage = 0, error; 2813 2814 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); 2815 if (nlh == NULL) 2816 return -EMSGSIZE; 2817 2818 r = nlmsg_data(nlh); 2819 r->rtm_family = AF_INET; 2820 r->rtm_dst_len = 32; 2821 r->rtm_src_len = 0; 2822 r->rtm_tos = rt->fl.fl4_tos; 2823 r->rtm_table = RT_TABLE_MAIN; 2824 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN); 2825 r->rtm_type = rt->rt_type; 2826 r->rtm_scope = RT_SCOPE_UNIVERSE; 2827 r->rtm_protocol = RTPROT_UNSPEC; 2828 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED; 2829 if (rt->rt_flags & RTCF_NOTIFY) 2830 r->rtm_flags |= RTM_F_NOTIFY; 2831 2832 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst); 2833 2834 if (rt->fl.fl4_src) { 2835 r->rtm_src_len = 32; 2836 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src); 2837 } 2838 if (rt->u.dst.dev) 2839 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex); 2840 #ifdef CONFIG_NET_CLS_ROUTE 2841 if (rt->u.dst.tclassid) 2842 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid); 2843 #endif 2844 if (rt->fl.iif) 2845 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst); 2846 else if (rt->rt_src != rt->fl.fl4_src) 2847 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src); 2848 2849 if (rt->rt_dst != rt->rt_gateway) 2850 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway); 2851 2852 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0) 2853 goto nla_put_failure; 2854 2855 error = rt->u.dst.error; 2856 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0; 2857 if (rt->peer) { 2858 id = rt->peer->ip_id_count; 2859 if (rt->peer->tcp_ts_stamp) { 2860 ts = rt->peer->tcp_ts; 2861 tsage = get_seconds() - rt->peer->tcp_ts_stamp; 2862 } 2863 } 2864 2865 if (rt->fl.iif) { 2866 #ifdef CONFIG_IP_MROUTE 2867 __be32 dst = rt->rt_dst; 2868 2869 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) && 2870 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) { 2871 int err = ipmr_get_route(net, skb, r, nowait); 2872 if (err <= 0) { 2873 if (!nowait) { 2874 if (err == 0) 2875 return 0; 2876 goto nla_put_failure; 2877 } else { 2878 if (err == -EMSGSIZE) 2879 goto nla_put_failure; 2880 error = err; 2881 } 2882 } 2883 } else 2884 #endif 2885 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif); 2886 } 2887 2888 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage, 2889 expires, error) < 0) 2890 goto nla_put_failure; 2891 2892 return nlmsg_end(skb, nlh); 2893 2894 nla_put_failure: 2895 nlmsg_cancel(skb, nlh); 2896 return -EMSGSIZE; 2897 } 2898 2899 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2900 { 2901 struct net *net = sock_net(in_skb->sk); 2902 struct rtmsg *rtm; 2903 struct nlattr *tb[RTA_MAX+1]; 2904 struct rtable *rt = NULL; 2905 __be32 dst = 0; 2906 __be32 src = 0; 2907 u32 iif; 2908 int err; 2909 struct sk_buff *skb; 2910 2911 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy); 2912 if (err < 0) 2913 goto errout; 2914 2915 rtm = nlmsg_data(nlh); 2916 2917 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2918 if (skb == NULL) { 2919 err = -ENOBUFS; 2920 goto errout; 2921 } 2922 2923 /* Reserve room for dummy headers, this skb can pass 2924 through good chunk of routing engine. 2925 */ 2926 skb_reset_mac_header(skb); 2927 skb_reset_network_header(skb); 2928 2929 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */ 2930 ip_hdr(skb)->protocol = IPPROTO_ICMP; 2931 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr)); 2932 2933 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0; 2934 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0; 2935 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0; 2936 2937 if (iif) { 2938 struct net_device *dev; 2939 2940 dev = __dev_get_by_index(net, iif); 2941 if (dev == NULL) { 2942 err = -ENODEV; 2943 goto errout_free; 2944 } 2945 2946 skb->protocol = htons(ETH_P_IP); 2947 skb->dev = dev; 2948 local_bh_disable(); 2949 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); 2950 local_bh_enable(); 2951 2952 rt = skb_rtable(skb); 2953 if (err == 0 && rt->u.dst.error) 2954 err = -rt->u.dst.error; 2955 } else { 2956 struct flowi fl = { 2957 .nl_u = { 2958 .ip4_u = { 2959 .daddr = dst, 2960 .saddr = src, 2961 .tos = rtm->rtm_tos, 2962 }, 2963 }, 2964 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0, 2965 }; 2966 err = ip_route_output_key(net, &rt, &fl); 2967 } 2968 2969 if (err) 2970 goto errout_free; 2971 2972 skb_dst_set(skb, &rt->u.dst); 2973 if (rtm->rtm_flags & RTM_F_NOTIFY) 2974 rt->rt_flags |= RTCF_NOTIFY; 2975 2976 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 2977 RTM_NEWROUTE, 0, 0); 2978 if (err <= 0) 2979 goto errout_free; 2980 2981 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); 2982 errout: 2983 return err; 2984 2985 errout_free: 2986 kfree_skb(skb); 2987 goto errout; 2988 } 2989 2990 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) 2991 { 2992 struct rtable *rt; 2993 int h, s_h; 2994 int idx, s_idx; 2995 struct net *net; 2996 2997 net = sock_net(skb->sk); 2998 2999 s_h = cb->args[0]; 3000 if (s_h < 0) 3001 s_h = 0; 3002 s_idx = idx = cb->args[1]; 3003 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) { 3004 if (!rt_hash_table[h].chain) 3005 continue; 3006 rcu_read_lock_bh(); 3007 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt; 3008 rt = rcu_dereference(rt->u.dst.rt_next), idx++) { 3009 if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx) 3010 continue; 3011 if (rt_is_expired(rt)) 3012 continue; 3013 skb_dst_set(skb, dst_clone(&rt->u.dst)); 3014 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid, 3015 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 3016 1, NLM_F_MULTI) <= 0) { 3017 skb_dst_drop(skb); 3018 rcu_read_unlock_bh(); 3019 goto done; 3020 } 3021 skb_dst_drop(skb); 3022 } 3023 rcu_read_unlock_bh(); 3024 } 3025 3026 done: 3027 cb->args[0] = h; 3028 cb->args[1] = idx; 3029 return skb->len; 3030 } 3031 3032 void ip_rt_multicast_event(struct in_device *in_dev) 3033 { 3034 rt_cache_flush(dev_net(in_dev->dev), 0); 3035 } 3036 3037 #ifdef CONFIG_SYSCTL 3038 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, 3039 struct file *filp, void __user *buffer, 3040 size_t *lenp, loff_t *ppos) 3041 { 3042 if (write) { 3043 int flush_delay; 3044 ctl_table ctl; 3045 struct net *net; 3046 3047 memcpy(&ctl, __ctl, sizeof(ctl)); 3048 ctl.data = &flush_delay; 3049 proc_dointvec(&ctl, write, filp, buffer, lenp, ppos); 3050 3051 net = (struct net *)__ctl->extra1; 3052 rt_cache_flush(net, flush_delay); 3053 return 0; 3054 } 3055 3056 return -EINVAL; 3057 } 3058 3059 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table, 3060 void __user *oldval, 3061 size_t __user *oldlenp, 3062 void __user *newval, 3063 size_t newlen) 3064 { 3065 int delay; 3066 struct net *net; 3067 if (newlen != sizeof(int)) 3068 return -EINVAL; 3069 if (get_user(delay, (int __user *)newval)) 3070 return -EFAULT; 3071 net = (struct net *)table->extra1; 3072 rt_cache_flush(net, delay); 3073 return 0; 3074 } 3075 3076 static void rt_secret_reschedule(int old) 3077 { 3078 struct net *net; 3079 int new = ip_rt_secret_interval; 3080 int diff = new - old; 3081 3082 if (!diff) 3083 return; 3084 3085 rtnl_lock(); 3086 for_each_net(net) { 3087 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer); 3088 3089 if (!new) 3090 continue; 3091 3092 if (deleted) { 3093 long time = net->ipv4.rt_secret_timer.expires - jiffies; 3094 3095 if (time <= 0 || (time += diff) <= 0) 3096 time = 0; 3097 3098 net->ipv4.rt_secret_timer.expires = time; 3099 } else 3100 net->ipv4.rt_secret_timer.expires = new; 3101 3102 net->ipv4.rt_secret_timer.expires += jiffies; 3103 add_timer(&net->ipv4.rt_secret_timer); 3104 } 3105 rtnl_unlock(); 3106 } 3107 3108 static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write, 3109 struct file *filp, 3110 void __user *buffer, size_t *lenp, 3111 loff_t *ppos) 3112 { 3113 int old = ip_rt_secret_interval; 3114 int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos); 3115 3116 rt_secret_reschedule(old); 3117 3118 return ret; 3119 } 3120 3121 static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table, 3122 void __user *oldval, 3123 size_t __user *oldlenp, 3124 void __user *newval, 3125 size_t newlen) 3126 { 3127 int old = ip_rt_secret_interval; 3128 int ret = sysctl_jiffies(table, oldval, oldlenp, newval, newlen); 3129 3130 rt_secret_reschedule(old); 3131 3132 return ret; 3133 } 3134 3135 static ctl_table ipv4_route_table[] = { 3136 { 3137 .ctl_name = NET_IPV4_ROUTE_GC_THRESH, 3138 .procname = "gc_thresh", 3139 .data = &ipv4_dst_ops.gc_thresh, 3140 .maxlen = sizeof(int), 3141 .mode = 0644, 3142 .proc_handler = proc_dointvec, 3143 }, 3144 { 3145 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE, 3146 .procname = "max_size", 3147 .data = &ip_rt_max_size, 3148 .maxlen = sizeof(int), 3149 .mode = 0644, 3150 .proc_handler = proc_dointvec, 3151 }, 3152 { 3153 /* Deprecated. Use gc_min_interval_ms */ 3154 3155 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL, 3156 .procname = "gc_min_interval", 3157 .data = &ip_rt_gc_min_interval, 3158 .maxlen = sizeof(int), 3159 .mode = 0644, 3160 .proc_handler = proc_dointvec_jiffies, 3161 .strategy = sysctl_jiffies, 3162 }, 3163 { 3164 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS, 3165 .procname = "gc_min_interval_ms", 3166 .data = &ip_rt_gc_min_interval, 3167 .maxlen = sizeof(int), 3168 .mode = 0644, 3169 .proc_handler = proc_dointvec_ms_jiffies, 3170 .strategy = sysctl_ms_jiffies, 3171 }, 3172 { 3173 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT, 3174 .procname = "gc_timeout", 3175 .data = &ip_rt_gc_timeout, 3176 .maxlen = sizeof(int), 3177 .mode = 0644, 3178 .proc_handler = proc_dointvec_jiffies, 3179 .strategy = sysctl_jiffies, 3180 }, 3181 { 3182 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL, 3183 .procname = "gc_interval", 3184 .data = &ip_rt_gc_interval, 3185 .maxlen = sizeof(int), 3186 .mode = 0644, 3187 .proc_handler = proc_dointvec_jiffies, 3188 .strategy = sysctl_jiffies, 3189 }, 3190 { 3191 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD, 3192 .procname = "redirect_load", 3193 .data = &ip_rt_redirect_load, 3194 .maxlen = sizeof(int), 3195 .mode = 0644, 3196 .proc_handler = proc_dointvec, 3197 }, 3198 { 3199 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER, 3200 .procname = "redirect_number", 3201 .data = &ip_rt_redirect_number, 3202 .maxlen = sizeof(int), 3203 .mode = 0644, 3204 .proc_handler = proc_dointvec, 3205 }, 3206 { 3207 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE, 3208 .procname = "redirect_silence", 3209 .data = &ip_rt_redirect_silence, 3210 .maxlen = sizeof(int), 3211 .mode = 0644, 3212 .proc_handler = proc_dointvec, 3213 }, 3214 { 3215 .ctl_name = NET_IPV4_ROUTE_ERROR_COST, 3216 .procname = "error_cost", 3217 .data = &ip_rt_error_cost, 3218 .maxlen = sizeof(int), 3219 .mode = 0644, 3220 .proc_handler = proc_dointvec, 3221 }, 3222 { 3223 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST, 3224 .procname = "error_burst", 3225 .data = &ip_rt_error_burst, 3226 .maxlen = sizeof(int), 3227 .mode = 0644, 3228 .proc_handler = proc_dointvec, 3229 }, 3230 { 3231 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY, 3232 .procname = "gc_elasticity", 3233 .data = &ip_rt_gc_elasticity, 3234 .maxlen = sizeof(int), 3235 .mode = 0644, 3236 .proc_handler = proc_dointvec, 3237 }, 3238 { 3239 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES, 3240 .procname = "mtu_expires", 3241 .data = &ip_rt_mtu_expires, 3242 .maxlen = sizeof(int), 3243 .mode = 0644, 3244 .proc_handler = proc_dointvec_jiffies, 3245 .strategy = sysctl_jiffies, 3246 }, 3247 { 3248 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU, 3249 .procname = "min_pmtu", 3250 .data = &ip_rt_min_pmtu, 3251 .maxlen = sizeof(int), 3252 .mode = 0644, 3253 .proc_handler = proc_dointvec, 3254 }, 3255 { 3256 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS, 3257 .procname = "min_adv_mss", 3258 .data = &ip_rt_min_advmss, 3259 .maxlen = sizeof(int), 3260 .mode = 0644, 3261 .proc_handler = proc_dointvec, 3262 }, 3263 { 3264 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL, 3265 .procname = "secret_interval", 3266 .data = &ip_rt_secret_interval, 3267 .maxlen = sizeof(int), 3268 .mode = 0644, 3269 .proc_handler = ipv4_sysctl_rt_secret_interval, 3270 .strategy = ipv4_sysctl_rt_secret_interval_strategy, 3271 }, 3272 { .ctl_name = 0 } 3273 }; 3274 3275 static struct ctl_table empty[1]; 3276 3277 static struct ctl_table ipv4_skeleton[] = 3278 { 3279 { .procname = "route", .ctl_name = NET_IPV4_ROUTE, 3280 .mode = 0555, .child = ipv4_route_table}, 3281 { .procname = "neigh", .ctl_name = NET_IPV4_NEIGH, 3282 .mode = 0555, .child = empty}, 3283 { } 3284 }; 3285 3286 static __net_initdata struct ctl_path ipv4_path[] = { 3287 { .procname = "net", .ctl_name = CTL_NET, }, 3288 { .procname = "ipv4", .ctl_name = NET_IPV4, }, 3289 { }, 3290 }; 3291 3292 static struct ctl_table ipv4_route_flush_table[] = { 3293 { 3294 .ctl_name = NET_IPV4_ROUTE_FLUSH, 3295 .procname = "flush", 3296 .maxlen = sizeof(int), 3297 .mode = 0200, 3298 .proc_handler = ipv4_sysctl_rtcache_flush, 3299 .strategy = ipv4_sysctl_rtcache_flush_strategy, 3300 }, 3301 { .ctl_name = 0 }, 3302 }; 3303 3304 static __net_initdata struct ctl_path ipv4_route_path[] = { 3305 { .procname = "net", .ctl_name = CTL_NET, }, 3306 { .procname = "ipv4", .ctl_name = NET_IPV4, }, 3307 { .procname = "route", .ctl_name = NET_IPV4_ROUTE, }, 3308 { }, 3309 }; 3310 3311 static __net_init int sysctl_route_net_init(struct net *net) 3312 { 3313 struct ctl_table *tbl; 3314 3315 tbl = ipv4_route_flush_table; 3316 if (net != &init_net) { 3317 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL); 3318 if (tbl == NULL) 3319 goto err_dup; 3320 } 3321 tbl[0].extra1 = net; 3322 3323 net->ipv4.route_hdr = 3324 register_net_sysctl_table(net, ipv4_route_path, tbl); 3325 if (net->ipv4.route_hdr == NULL) 3326 goto err_reg; 3327 return 0; 3328 3329 err_reg: 3330 if (tbl != ipv4_route_flush_table) 3331 kfree(tbl); 3332 err_dup: 3333 return -ENOMEM; 3334 } 3335 3336 static __net_exit void sysctl_route_net_exit(struct net *net) 3337 { 3338 struct ctl_table *tbl; 3339 3340 tbl = net->ipv4.route_hdr->ctl_table_arg; 3341 unregister_net_sysctl_table(net->ipv4.route_hdr); 3342 BUG_ON(tbl == ipv4_route_flush_table); 3343 kfree(tbl); 3344 } 3345 3346 static __net_initdata struct pernet_operations sysctl_route_ops = { 3347 .init = sysctl_route_net_init, 3348 .exit = sysctl_route_net_exit, 3349 }; 3350 #endif 3351 3352 3353 static __net_init int rt_secret_timer_init(struct net *net) 3354 { 3355 atomic_set(&net->ipv4.rt_genid, 3356 (int) ((num_physpages ^ (num_physpages>>8)) ^ 3357 (jiffies ^ (jiffies >> 7)))); 3358 3359 net->ipv4.rt_secret_timer.function = rt_secret_rebuild; 3360 net->ipv4.rt_secret_timer.data = (unsigned long)net; 3361 init_timer_deferrable(&net->ipv4.rt_secret_timer); 3362 3363 if (ip_rt_secret_interval) { 3364 net->ipv4.rt_secret_timer.expires = 3365 jiffies + net_random() % ip_rt_secret_interval + 3366 ip_rt_secret_interval; 3367 add_timer(&net->ipv4.rt_secret_timer); 3368 } 3369 return 0; 3370 } 3371 3372 static __net_exit void rt_secret_timer_exit(struct net *net) 3373 { 3374 del_timer_sync(&net->ipv4.rt_secret_timer); 3375 } 3376 3377 static __net_initdata struct pernet_operations rt_secret_timer_ops = { 3378 .init = rt_secret_timer_init, 3379 .exit = rt_secret_timer_exit, 3380 }; 3381 3382 3383 #ifdef CONFIG_NET_CLS_ROUTE 3384 struct ip_rt_acct *ip_rt_acct __read_mostly; 3385 #endif /* CONFIG_NET_CLS_ROUTE */ 3386 3387 static __initdata unsigned long rhash_entries; 3388 static int __init set_rhash_entries(char *str) 3389 { 3390 if (!str) 3391 return 0; 3392 rhash_entries = simple_strtoul(str, &str, 0); 3393 return 1; 3394 } 3395 __setup("rhash_entries=", set_rhash_entries); 3396 3397 int __init ip_rt_init(void) 3398 { 3399 int rc = 0; 3400 3401 #ifdef CONFIG_NET_CLS_ROUTE 3402 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct)); 3403 if (!ip_rt_acct) 3404 panic("IP: failed to allocate ip_rt_acct\n"); 3405 #endif 3406 3407 ipv4_dst_ops.kmem_cachep = 3408 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0, 3409 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); 3410 3411 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep; 3412 3413 rt_hash_table = (struct rt_hash_bucket *) 3414 alloc_large_system_hash("IP route cache", 3415 sizeof(struct rt_hash_bucket), 3416 rhash_entries, 3417 (num_physpages >= 128 * 1024) ? 3418 15 : 17, 3419 0, 3420 &rt_hash_log, 3421 &rt_hash_mask, 3422 rhash_entries ? 0 : 512 * 1024); 3423 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket)); 3424 rt_hash_lock_init(); 3425 3426 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1); 3427 ip_rt_max_size = (rt_hash_mask + 1) * 16; 3428 3429 devinet_init(); 3430 ip_fib_init(); 3431 3432 /* All the timers, started at system startup tend 3433 to synchronize. Perturb it a bit. 3434 */ 3435 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func); 3436 expires_ljiffies = jiffies; 3437 schedule_delayed_work(&expires_work, 3438 net_random() % ip_rt_gc_interval + ip_rt_gc_interval); 3439 3440 if (register_pernet_subsys(&rt_secret_timer_ops)) 3441 printk(KERN_ERR "Unable to setup rt_secret_timer\n"); 3442 3443 if (ip_rt_proc_init()) 3444 printk(KERN_ERR "Unable to create route proc files\n"); 3445 #ifdef CONFIG_XFRM 3446 xfrm_init(); 3447 xfrm4_init(ip_rt_max_size); 3448 #endif 3449 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL); 3450 3451 #ifdef CONFIG_SYSCTL 3452 register_pernet_subsys(&sysctl_route_ops); 3453 #endif 3454 return rc; 3455 } 3456 3457 #ifdef CONFIG_SYSCTL 3458 /* 3459 * We really need to sanitize the damn ipv4 init order, then all 3460 * this nonsense will go away. 3461 */ 3462 void __init ip_static_sysctl_init(void) 3463 { 3464 register_sysctl_paths(ipv4_path, ipv4_skeleton); 3465 } 3466 #endif 3467 3468 EXPORT_SYMBOL(__ip_select_ident); 3469 EXPORT_SYMBOL(ip_route_input); 3470 EXPORT_SYMBOL(ip_route_output_key); 3471