1 /* 2 * Linux INET6 implementation 3 * Forwarding Information Database 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * Changes: 14 * Yuji SEKIYA @USAGI: Support default route on router node; 15 * remove ip6_null_entry from the top of 16 * routing table. 17 * Ville Nuorvala: Fixed routing subtrees. 18 */ 19 20 #define pr_fmt(fmt) "IPv6: " fmt 21 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/net.h> 25 #include <linux/route.h> 26 #include <linux/netdevice.h> 27 #include <linux/in6.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/slab.h> 31 32 #include <net/ipv6.h> 33 #include <net/ndisc.h> 34 #include <net/addrconf.h> 35 36 #include <net/ip6_fib.h> 37 #include <net/ip6_route.h> 38 39 #define RT6_DEBUG 2 40 41 #if RT6_DEBUG >= 3 42 #define RT6_TRACE(x...) pr_debug(x) 43 #else 44 #define RT6_TRACE(x...) do { ; } while (0) 45 #endif 46 47 static struct kmem_cache *fib6_node_kmem __read_mostly; 48 49 enum fib_walk_state_t { 50 #ifdef CONFIG_IPV6_SUBTREES 51 FWS_S, 52 #endif 53 FWS_L, 54 FWS_R, 55 FWS_C, 56 FWS_U 57 }; 58 59 struct fib6_cleaner_t { 60 struct fib6_walker_t w; 61 struct net *net; 62 int (*func)(struct rt6_info *, void *arg); 63 void *arg; 64 }; 65 66 static DEFINE_RWLOCK(fib6_walker_lock); 67 68 #ifdef CONFIG_IPV6_SUBTREES 69 #define FWS_INIT FWS_S 70 #else 71 #define FWS_INIT FWS_L 72 #endif 73 74 static void fib6_prune_clones(struct net *net, struct fib6_node *fn, 75 struct rt6_info *rt); 76 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 77 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 78 static int fib6_walk(struct fib6_walker_t *w); 79 static int fib6_walk_continue(struct fib6_walker_t *w); 80 81 /* 82 * A routing update causes an increase of the serial number on the 83 * affected subtree. This allows for cached routes to be asynchronously 84 * tested when modifications are made to the destination cache as a 85 * result of redirects, path MTU changes, etc. 86 */ 87 88 static __u32 rt_sernum; 89 90 static void fib6_gc_timer_cb(unsigned long arg); 91 92 static LIST_HEAD(fib6_walkers); 93 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh) 94 95 static inline void fib6_walker_link(struct fib6_walker_t *w) 96 { 97 write_lock_bh(&fib6_walker_lock); 98 list_add(&w->lh, &fib6_walkers); 99 write_unlock_bh(&fib6_walker_lock); 100 } 101 102 static inline void fib6_walker_unlink(struct fib6_walker_t *w) 103 { 104 write_lock_bh(&fib6_walker_lock); 105 list_del(&w->lh); 106 write_unlock_bh(&fib6_walker_lock); 107 } 108 static __inline__ u32 fib6_new_sernum(void) 109 { 110 u32 n = ++rt_sernum; 111 if ((__s32)n <= 0) 112 rt_sernum = n = 1; 113 return n; 114 } 115 116 /* 117 * Auxiliary address test functions for the radix tree. 118 * 119 * These assume a 32bit processor (although it will work on 120 * 64bit processors) 121 */ 122 123 /* 124 * test bit 125 */ 126 #if defined(__LITTLE_ENDIAN) 127 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 128 #else 129 # define BITOP_BE32_SWIZZLE 0 130 #endif 131 132 static __inline__ __be32 addr_bit_set(const void *token, int fn_bit) 133 { 134 const __be32 *addr = token; 135 /* 136 * Here, 137 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 138 * is optimized version of 139 * htonl(1 << ((~fn_bit)&0x1F)) 140 * See include/asm-generic/bitops/le.h. 141 */ 142 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 143 addr[fn_bit >> 5]; 144 } 145 146 static __inline__ struct fib6_node *node_alloc(void) 147 { 148 struct fib6_node *fn; 149 150 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 151 152 return fn; 153 } 154 155 static __inline__ void node_free(struct fib6_node *fn) 156 { 157 kmem_cache_free(fib6_node_kmem, fn); 158 } 159 160 static __inline__ void rt6_release(struct rt6_info *rt) 161 { 162 if (atomic_dec_and_test(&rt->rt6i_ref)) 163 dst_free(&rt->dst); 164 } 165 166 static void fib6_link_table(struct net *net, struct fib6_table *tb) 167 { 168 unsigned int h; 169 170 /* 171 * Initialize table lock at a single place to give lockdep a key, 172 * tables aren't visible prior to being linked to the list. 173 */ 174 rwlock_init(&tb->tb6_lock); 175 176 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 177 178 /* 179 * No protection necessary, this is the only list mutatation 180 * operation, tables never disappear once they exist. 181 */ 182 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 183 } 184 185 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 186 187 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 188 { 189 struct fib6_table *table; 190 191 table = kzalloc(sizeof(*table), GFP_ATOMIC); 192 if (table) { 193 table->tb6_id = id; 194 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 195 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 196 inet_peer_base_init(&table->tb6_peers); 197 } 198 199 return table; 200 } 201 202 struct fib6_table *fib6_new_table(struct net *net, u32 id) 203 { 204 struct fib6_table *tb; 205 206 if (id == 0) 207 id = RT6_TABLE_MAIN; 208 tb = fib6_get_table(net, id); 209 if (tb) 210 return tb; 211 212 tb = fib6_alloc_table(net, id); 213 if (tb) 214 fib6_link_table(net, tb); 215 216 return tb; 217 } 218 219 struct fib6_table *fib6_get_table(struct net *net, u32 id) 220 { 221 struct fib6_table *tb; 222 struct hlist_head *head; 223 unsigned int h; 224 225 if (id == 0) 226 id = RT6_TABLE_MAIN; 227 h = id & (FIB6_TABLE_HASHSZ - 1); 228 rcu_read_lock(); 229 head = &net->ipv6.fib_table_hash[h]; 230 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 231 if (tb->tb6_id == id) { 232 rcu_read_unlock(); 233 return tb; 234 } 235 } 236 rcu_read_unlock(); 237 238 return NULL; 239 } 240 241 static void __net_init fib6_tables_init(struct net *net) 242 { 243 fib6_link_table(net, net->ipv6.fib6_main_tbl); 244 fib6_link_table(net, net->ipv6.fib6_local_tbl); 245 } 246 #else 247 248 struct fib6_table *fib6_new_table(struct net *net, u32 id) 249 { 250 return fib6_get_table(net, id); 251 } 252 253 struct fib6_table *fib6_get_table(struct net *net, u32 id) 254 { 255 return net->ipv6.fib6_main_tbl; 256 } 257 258 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 259 int flags, pol_lookup_t lookup) 260 { 261 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 262 } 263 264 static void __net_init fib6_tables_init(struct net *net) 265 { 266 fib6_link_table(net, net->ipv6.fib6_main_tbl); 267 } 268 269 #endif 270 271 static int fib6_dump_node(struct fib6_walker_t *w) 272 { 273 int res; 274 struct rt6_info *rt; 275 276 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 277 res = rt6_dump_route(rt, w->args); 278 if (res < 0) { 279 /* Frame is full, suspend walking */ 280 w->leaf = rt; 281 return 1; 282 } 283 WARN_ON(res == 0); 284 } 285 w->leaf = NULL; 286 return 0; 287 } 288 289 static void fib6_dump_end(struct netlink_callback *cb) 290 { 291 struct fib6_walker_t *w = (void *)cb->args[2]; 292 293 if (w) { 294 if (cb->args[4]) { 295 cb->args[4] = 0; 296 fib6_walker_unlink(w); 297 } 298 cb->args[2] = 0; 299 kfree(w); 300 } 301 cb->done = (void *)cb->args[3]; 302 cb->args[1] = 3; 303 } 304 305 static int fib6_dump_done(struct netlink_callback *cb) 306 { 307 fib6_dump_end(cb); 308 return cb->done ? cb->done(cb) : 0; 309 } 310 311 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 312 struct netlink_callback *cb) 313 { 314 struct fib6_walker_t *w; 315 int res; 316 317 w = (void *)cb->args[2]; 318 w->root = &table->tb6_root; 319 320 if (cb->args[4] == 0) { 321 w->count = 0; 322 w->skip = 0; 323 324 read_lock_bh(&table->tb6_lock); 325 res = fib6_walk(w); 326 read_unlock_bh(&table->tb6_lock); 327 if (res > 0) { 328 cb->args[4] = 1; 329 cb->args[5] = w->root->fn_sernum; 330 } 331 } else { 332 if (cb->args[5] != w->root->fn_sernum) { 333 /* Begin at the root if the tree changed */ 334 cb->args[5] = w->root->fn_sernum; 335 w->state = FWS_INIT; 336 w->node = w->root; 337 w->skip = w->count; 338 } else 339 w->skip = 0; 340 341 read_lock_bh(&table->tb6_lock); 342 res = fib6_walk_continue(w); 343 read_unlock_bh(&table->tb6_lock); 344 if (res <= 0) { 345 fib6_walker_unlink(w); 346 cb->args[4] = 0; 347 } 348 } 349 350 return res; 351 } 352 353 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 354 { 355 struct net *net = sock_net(skb->sk); 356 unsigned int h, s_h; 357 unsigned int e = 0, s_e; 358 struct rt6_rtnl_dump_arg arg; 359 struct fib6_walker_t *w; 360 struct fib6_table *tb; 361 struct hlist_head *head; 362 int res = 0; 363 364 s_h = cb->args[0]; 365 s_e = cb->args[1]; 366 367 w = (void *)cb->args[2]; 368 if (!w) { 369 /* New dump: 370 * 371 * 1. hook callback destructor. 372 */ 373 cb->args[3] = (long)cb->done; 374 cb->done = fib6_dump_done; 375 376 /* 377 * 2. allocate and initialize walker. 378 */ 379 w = kzalloc(sizeof(*w), GFP_ATOMIC); 380 if (!w) 381 return -ENOMEM; 382 w->func = fib6_dump_node; 383 cb->args[2] = (long)w; 384 } 385 386 arg.skb = skb; 387 arg.cb = cb; 388 arg.net = net; 389 w->args = &arg; 390 391 rcu_read_lock(); 392 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 393 e = 0; 394 head = &net->ipv6.fib_table_hash[h]; 395 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 396 if (e < s_e) 397 goto next; 398 res = fib6_dump_table(tb, skb, cb); 399 if (res != 0) 400 goto out; 401 next: 402 e++; 403 } 404 } 405 out: 406 rcu_read_unlock(); 407 cb->args[1] = e; 408 cb->args[0] = h; 409 410 res = res < 0 ? res : skb->len; 411 if (res <= 0) 412 fib6_dump_end(cb); 413 return res; 414 } 415 416 /* 417 * Routing Table 418 * 419 * return the appropriate node for a routing tree "add" operation 420 * by either creating and inserting or by returning an existing 421 * node. 422 */ 423 424 static struct fib6_node *fib6_add_1(struct fib6_node *root, 425 struct in6_addr *addr, int plen, 426 int offset, int allow_create, 427 int replace_required) 428 { 429 struct fib6_node *fn, *in, *ln; 430 struct fib6_node *pn = NULL; 431 struct rt6key *key; 432 int bit; 433 __be32 dir = 0; 434 __u32 sernum = fib6_new_sernum(); 435 436 RT6_TRACE("fib6_add_1\n"); 437 438 /* insert node in tree */ 439 440 fn = root; 441 442 do { 443 key = (struct rt6key *)((u8 *)fn->leaf + offset); 444 445 /* 446 * Prefix match 447 */ 448 if (plen < fn->fn_bit || 449 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 450 if (!allow_create) { 451 if (replace_required) { 452 pr_warn("Can't replace route, no match found\n"); 453 return ERR_PTR(-ENOENT); 454 } 455 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 456 } 457 goto insert_above; 458 } 459 460 /* 461 * Exact match ? 462 */ 463 464 if (plen == fn->fn_bit) { 465 /* clean up an intermediate node */ 466 if (!(fn->fn_flags & RTN_RTINFO)) { 467 rt6_release(fn->leaf); 468 fn->leaf = NULL; 469 } 470 471 fn->fn_sernum = sernum; 472 473 return fn; 474 } 475 476 /* 477 * We have more bits to go 478 */ 479 480 /* Try to walk down on tree. */ 481 fn->fn_sernum = sernum; 482 dir = addr_bit_set(addr, fn->fn_bit); 483 pn = fn; 484 fn = dir ? fn->right : fn->left; 485 } while (fn); 486 487 if (!allow_create) { 488 /* We should not create new node because 489 * NLM_F_REPLACE was specified without NLM_F_CREATE 490 * I assume it is safe to require NLM_F_CREATE when 491 * REPLACE flag is used! Later we may want to remove the 492 * check for replace_required, because according 493 * to netlink specification, NLM_F_CREATE 494 * MUST be specified if new route is created. 495 * That would keep IPv6 consistent with IPv4 496 */ 497 if (replace_required) { 498 pr_warn("Can't replace route, no match found\n"); 499 return ERR_PTR(-ENOENT); 500 } 501 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 502 } 503 /* 504 * We walked to the bottom of tree. 505 * Create new leaf node without children. 506 */ 507 508 ln = node_alloc(); 509 510 if (!ln) 511 return ERR_PTR(-ENOMEM); 512 ln->fn_bit = plen; 513 514 ln->parent = pn; 515 ln->fn_sernum = sernum; 516 517 if (dir) 518 pn->right = ln; 519 else 520 pn->left = ln; 521 522 return ln; 523 524 525 insert_above: 526 /* 527 * split since we don't have a common prefix anymore or 528 * we have a less significant route. 529 * we've to insert an intermediate node on the list 530 * this new node will point to the one we need to create 531 * and the current 532 */ 533 534 pn = fn->parent; 535 536 /* find 1st bit in difference between the 2 addrs. 537 538 See comment in __ipv6_addr_diff: bit may be an invalid value, 539 but if it is >= plen, the value is ignored in any case. 540 */ 541 542 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 543 544 /* 545 * (intermediate)[in] 546 * / \ 547 * (new leaf node)[ln] (old node)[fn] 548 */ 549 if (plen > bit) { 550 in = node_alloc(); 551 ln = node_alloc(); 552 553 if (!in || !ln) { 554 if (in) 555 node_free(in); 556 if (ln) 557 node_free(ln); 558 return ERR_PTR(-ENOMEM); 559 } 560 561 /* 562 * new intermediate node. 563 * RTN_RTINFO will 564 * be off since that an address that chooses one of 565 * the branches would not match less specific routes 566 * in the other branch 567 */ 568 569 in->fn_bit = bit; 570 571 in->parent = pn; 572 in->leaf = fn->leaf; 573 atomic_inc(&in->leaf->rt6i_ref); 574 575 in->fn_sernum = sernum; 576 577 /* update parent pointer */ 578 if (dir) 579 pn->right = in; 580 else 581 pn->left = in; 582 583 ln->fn_bit = plen; 584 585 ln->parent = in; 586 fn->parent = in; 587 588 ln->fn_sernum = sernum; 589 590 if (addr_bit_set(addr, bit)) { 591 in->right = ln; 592 in->left = fn; 593 } else { 594 in->left = ln; 595 in->right = fn; 596 } 597 } else { /* plen <= bit */ 598 599 /* 600 * (new leaf node)[ln] 601 * / \ 602 * (old node)[fn] NULL 603 */ 604 605 ln = node_alloc(); 606 607 if (!ln) 608 return ERR_PTR(-ENOMEM); 609 610 ln->fn_bit = plen; 611 612 ln->parent = pn; 613 614 ln->fn_sernum = sernum; 615 616 if (dir) 617 pn->right = ln; 618 else 619 pn->left = ln; 620 621 if (addr_bit_set(&key->addr, plen)) 622 ln->right = fn; 623 else 624 ln->left = fn; 625 626 fn->parent = ln; 627 } 628 return ln; 629 } 630 631 static inline bool rt6_qualify_for_ecmp(struct rt6_info *rt) 632 { 633 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 634 RTF_GATEWAY; 635 } 636 637 static int fib6_commit_metrics(struct dst_entry *dst, 638 struct nlattr *mx, int mx_len) 639 { 640 struct nlattr *nla; 641 int remaining; 642 u32 *mp; 643 644 if (dst->flags & DST_HOST) { 645 mp = dst_metrics_write_ptr(dst); 646 } else { 647 mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL); 648 if (!mp) 649 return -ENOMEM; 650 dst_init_metrics(dst, mp, 0); 651 } 652 653 nla_for_each_attr(nla, mx, mx_len, remaining) { 654 int type = nla_type(nla); 655 656 if (type) { 657 if (type > RTAX_MAX) 658 return -EINVAL; 659 660 mp[type - 1] = nla_get_u32(nla); 661 } 662 } 663 return 0; 664 } 665 666 /* 667 * Insert routing information in a node. 668 */ 669 670 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 671 struct nl_info *info, struct nlattr *mx, int mx_len) 672 { 673 struct rt6_info *iter = NULL; 674 struct rt6_info **ins; 675 int replace = (info->nlh && 676 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 677 int add = (!info->nlh || 678 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 679 int found = 0; 680 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 681 int err; 682 683 ins = &fn->leaf; 684 685 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 686 /* 687 * Search for duplicates 688 */ 689 690 if (iter->rt6i_metric == rt->rt6i_metric) { 691 /* 692 * Same priority level 693 */ 694 if (info->nlh && 695 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 696 return -EEXIST; 697 if (replace) { 698 found++; 699 break; 700 } 701 702 if (iter->dst.dev == rt->dst.dev && 703 iter->rt6i_idev == rt->rt6i_idev && 704 ipv6_addr_equal(&iter->rt6i_gateway, 705 &rt->rt6i_gateway)) { 706 if (rt->rt6i_nsiblings) 707 rt->rt6i_nsiblings = 0; 708 if (!(iter->rt6i_flags & RTF_EXPIRES)) 709 return -EEXIST; 710 if (!(rt->rt6i_flags & RTF_EXPIRES)) 711 rt6_clean_expires(iter); 712 else 713 rt6_set_expires(iter, rt->dst.expires); 714 return -EEXIST; 715 } 716 /* If we have the same destination and the same metric, 717 * but not the same gateway, then the route we try to 718 * add is sibling to this route, increment our counter 719 * of siblings, and later we will add our route to the 720 * list. 721 * Only static routes (which don't have flag 722 * RTF_EXPIRES) are used for ECMPv6. 723 * 724 * To avoid long list, we only had siblings if the 725 * route have a gateway. 726 */ 727 if (rt_can_ecmp && 728 rt6_qualify_for_ecmp(iter)) 729 rt->rt6i_nsiblings++; 730 } 731 732 if (iter->rt6i_metric > rt->rt6i_metric) 733 break; 734 735 ins = &iter->dst.rt6_next; 736 } 737 738 /* Reset round-robin state, if necessary */ 739 if (ins == &fn->leaf) 740 fn->rr_ptr = NULL; 741 742 /* Link this route to others same route. */ 743 if (rt->rt6i_nsiblings) { 744 unsigned int rt6i_nsiblings; 745 struct rt6_info *sibling, *temp_sibling; 746 747 /* Find the first route that have the same metric */ 748 sibling = fn->leaf; 749 while (sibling) { 750 if (sibling->rt6i_metric == rt->rt6i_metric && 751 rt6_qualify_for_ecmp(sibling)) { 752 list_add_tail(&rt->rt6i_siblings, 753 &sibling->rt6i_siblings); 754 break; 755 } 756 sibling = sibling->dst.rt6_next; 757 } 758 /* For each sibling in the list, increment the counter of 759 * siblings. BUG() if counters does not match, list of siblings 760 * is broken! 761 */ 762 rt6i_nsiblings = 0; 763 list_for_each_entry_safe(sibling, temp_sibling, 764 &rt->rt6i_siblings, rt6i_siblings) { 765 sibling->rt6i_nsiblings++; 766 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 767 rt6i_nsiblings++; 768 } 769 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 770 } 771 772 /* 773 * insert node 774 */ 775 if (!replace) { 776 if (!add) 777 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 778 779 add: 780 if (mx) { 781 err = fib6_commit_metrics(&rt->dst, mx, mx_len); 782 if (err) 783 return err; 784 } 785 rt->dst.rt6_next = iter; 786 *ins = rt; 787 rt->rt6i_node = fn; 788 atomic_inc(&rt->rt6i_ref); 789 inet6_rt_notify(RTM_NEWROUTE, rt, info); 790 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 791 792 if (!(fn->fn_flags & RTN_RTINFO)) { 793 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 794 fn->fn_flags |= RTN_RTINFO; 795 } 796 797 } else { 798 if (!found) { 799 if (add) 800 goto add; 801 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 802 return -ENOENT; 803 } 804 if (mx) { 805 err = fib6_commit_metrics(&rt->dst, mx, mx_len); 806 if (err) 807 return err; 808 } 809 *ins = rt; 810 rt->rt6i_node = fn; 811 rt->dst.rt6_next = iter->dst.rt6_next; 812 atomic_inc(&rt->rt6i_ref); 813 inet6_rt_notify(RTM_NEWROUTE, rt, info); 814 rt6_release(iter); 815 if (!(fn->fn_flags & RTN_RTINFO)) { 816 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 817 fn->fn_flags |= RTN_RTINFO; 818 } 819 } 820 821 return 0; 822 } 823 824 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt) 825 { 826 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 827 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 828 mod_timer(&net->ipv6.ip6_fib_timer, 829 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 830 } 831 832 void fib6_force_start_gc(struct net *net) 833 { 834 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 835 mod_timer(&net->ipv6.ip6_fib_timer, 836 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 837 } 838 839 /* 840 * Add routing information to the routing tree. 841 * <destination addr>/<source addr> 842 * with source addr info in sub-trees 843 */ 844 845 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info, 846 struct nlattr *mx, int mx_len) 847 { 848 struct fib6_node *fn, *pn = NULL; 849 int err = -ENOMEM; 850 int allow_create = 1; 851 int replace_required = 0; 852 853 if (info->nlh) { 854 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 855 allow_create = 0; 856 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 857 replace_required = 1; 858 } 859 if (!allow_create && !replace_required) 860 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 861 862 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 863 offsetof(struct rt6_info, rt6i_dst), allow_create, 864 replace_required); 865 if (IS_ERR(fn)) { 866 err = PTR_ERR(fn); 867 fn = NULL; 868 goto out; 869 } 870 871 pn = fn; 872 873 #ifdef CONFIG_IPV6_SUBTREES 874 if (rt->rt6i_src.plen) { 875 struct fib6_node *sn; 876 877 if (!fn->subtree) { 878 struct fib6_node *sfn; 879 880 /* 881 * Create subtree. 882 * 883 * fn[main tree] 884 * | 885 * sfn[subtree root] 886 * \ 887 * sn[new leaf node] 888 */ 889 890 /* Create subtree root node */ 891 sfn = node_alloc(); 892 if (!sfn) 893 goto st_failure; 894 895 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 896 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 897 sfn->fn_flags = RTN_ROOT; 898 sfn->fn_sernum = fib6_new_sernum(); 899 900 /* Now add the first leaf node to new subtree */ 901 902 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 903 rt->rt6i_src.plen, 904 offsetof(struct rt6_info, rt6i_src), 905 allow_create, replace_required); 906 907 if (IS_ERR(sn)) { 908 /* If it is failed, discard just allocated 909 root, and then (in st_failure) stale node 910 in main tree. 911 */ 912 node_free(sfn); 913 err = PTR_ERR(sn); 914 goto st_failure; 915 } 916 917 /* Now link new subtree to main tree */ 918 sfn->parent = fn; 919 fn->subtree = sfn; 920 } else { 921 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 922 rt->rt6i_src.plen, 923 offsetof(struct rt6_info, rt6i_src), 924 allow_create, replace_required); 925 926 if (IS_ERR(sn)) { 927 err = PTR_ERR(sn); 928 goto st_failure; 929 } 930 } 931 932 if (!fn->leaf) { 933 fn->leaf = rt; 934 atomic_inc(&rt->rt6i_ref); 935 } 936 fn = sn; 937 } 938 #endif 939 940 err = fib6_add_rt2node(fn, rt, info, mx, mx_len); 941 if (!err) { 942 fib6_start_gc(info->nl_net, rt); 943 if (!(rt->rt6i_flags & RTF_CACHE)) 944 fib6_prune_clones(info->nl_net, pn, rt); 945 } 946 947 out: 948 if (err) { 949 #ifdef CONFIG_IPV6_SUBTREES 950 /* 951 * If fib6_add_1 has cleared the old leaf pointer in the 952 * super-tree leaf node we have to find a new one for it. 953 */ 954 if (pn != fn && pn->leaf == rt) { 955 pn->leaf = NULL; 956 atomic_dec(&rt->rt6i_ref); 957 } 958 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 959 pn->leaf = fib6_find_prefix(info->nl_net, pn); 960 #if RT6_DEBUG >= 2 961 if (!pn->leaf) { 962 WARN_ON(pn->leaf == NULL); 963 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 964 } 965 #endif 966 atomic_inc(&pn->leaf->rt6i_ref); 967 } 968 #endif 969 dst_free(&rt->dst); 970 } 971 return err; 972 973 #ifdef CONFIG_IPV6_SUBTREES 974 /* Subtree creation failed, probably main tree node 975 is orphan. If it is, shoot it. 976 */ 977 st_failure: 978 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 979 fib6_repair_tree(info->nl_net, fn); 980 dst_free(&rt->dst); 981 return err; 982 #endif 983 } 984 985 /* 986 * Routing tree lookup 987 * 988 */ 989 990 struct lookup_args { 991 int offset; /* key offset on rt6_info */ 992 const struct in6_addr *addr; /* search key */ 993 }; 994 995 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 996 struct lookup_args *args) 997 { 998 struct fib6_node *fn; 999 __be32 dir; 1000 1001 if (unlikely(args->offset == 0)) 1002 return NULL; 1003 1004 /* 1005 * Descend on a tree 1006 */ 1007 1008 fn = root; 1009 1010 for (;;) { 1011 struct fib6_node *next; 1012 1013 dir = addr_bit_set(args->addr, fn->fn_bit); 1014 1015 next = dir ? fn->right : fn->left; 1016 1017 if (next) { 1018 fn = next; 1019 continue; 1020 } 1021 break; 1022 } 1023 1024 while (fn) { 1025 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1026 struct rt6key *key; 1027 1028 key = (struct rt6key *) ((u8 *) fn->leaf + 1029 args->offset); 1030 1031 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1032 #ifdef CONFIG_IPV6_SUBTREES 1033 if (fn->subtree) { 1034 struct fib6_node *sfn; 1035 sfn = fib6_lookup_1(fn->subtree, 1036 args + 1); 1037 if (!sfn) 1038 goto backtrack; 1039 fn = sfn; 1040 } 1041 #endif 1042 if (fn->fn_flags & RTN_RTINFO) 1043 return fn; 1044 } 1045 } 1046 #ifdef CONFIG_IPV6_SUBTREES 1047 backtrack: 1048 #endif 1049 if (fn->fn_flags & RTN_ROOT) 1050 break; 1051 1052 fn = fn->parent; 1053 } 1054 1055 return NULL; 1056 } 1057 1058 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1059 const struct in6_addr *saddr) 1060 { 1061 struct fib6_node *fn; 1062 struct lookup_args args[] = { 1063 { 1064 .offset = offsetof(struct rt6_info, rt6i_dst), 1065 .addr = daddr, 1066 }, 1067 #ifdef CONFIG_IPV6_SUBTREES 1068 { 1069 .offset = offsetof(struct rt6_info, rt6i_src), 1070 .addr = saddr, 1071 }, 1072 #endif 1073 { 1074 .offset = 0, /* sentinel */ 1075 } 1076 }; 1077 1078 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1079 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1080 fn = root; 1081 1082 return fn; 1083 } 1084 1085 /* 1086 * Get node with specified destination prefix (and source prefix, 1087 * if subtrees are used) 1088 */ 1089 1090 1091 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1092 const struct in6_addr *addr, 1093 int plen, int offset) 1094 { 1095 struct fib6_node *fn; 1096 1097 for (fn = root; fn ; ) { 1098 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1099 1100 /* 1101 * Prefix match 1102 */ 1103 if (plen < fn->fn_bit || 1104 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1105 return NULL; 1106 1107 if (plen == fn->fn_bit) 1108 return fn; 1109 1110 /* 1111 * We have more bits to go 1112 */ 1113 if (addr_bit_set(addr, fn->fn_bit)) 1114 fn = fn->right; 1115 else 1116 fn = fn->left; 1117 } 1118 return NULL; 1119 } 1120 1121 struct fib6_node *fib6_locate(struct fib6_node *root, 1122 const struct in6_addr *daddr, int dst_len, 1123 const struct in6_addr *saddr, int src_len) 1124 { 1125 struct fib6_node *fn; 1126 1127 fn = fib6_locate_1(root, daddr, dst_len, 1128 offsetof(struct rt6_info, rt6i_dst)); 1129 1130 #ifdef CONFIG_IPV6_SUBTREES 1131 if (src_len) { 1132 WARN_ON(saddr == NULL); 1133 if (fn && fn->subtree) 1134 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1135 offsetof(struct rt6_info, rt6i_src)); 1136 } 1137 #endif 1138 1139 if (fn && fn->fn_flags & RTN_RTINFO) 1140 return fn; 1141 1142 return NULL; 1143 } 1144 1145 1146 /* 1147 * Deletion 1148 * 1149 */ 1150 1151 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1152 { 1153 if (fn->fn_flags & RTN_ROOT) 1154 return net->ipv6.ip6_null_entry; 1155 1156 while (fn) { 1157 if (fn->left) 1158 return fn->left->leaf; 1159 if (fn->right) 1160 return fn->right->leaf; 1161 1162 fn = FIB6_SUBTREE(fn); 1163 } 1164 return NULL; 1165 } 1166 1167 /* 1168 * Called to trim the tree of intermediate nodes when possible. "fn" 1169 * is the node we want to try and remove. 1170 */ 1171 1172 static struct fib6_node *fib6_repair_tree(struct net *net, 1173 struct fib6_node *fn) 1174 { 1175 int children; 1176 int nstate; 1177 struct fib6_node *child, *pn; 1178 struct fib6_walker_t *w; 1179 int iter = 0; 1180 1181 for (;;) { 1182 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1183 iter++; 1184 1185 WARN_ON(fn->fn_flags & RTN_RTINFO); 1186 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1187 WARN_ON(fn->leaf != NULL); 1188 1189 children = 0; 1190 child = NULL; 1191 if (fn->right) 1192 child = fn->right, children |= 1; 1193 if (fn->left) 1194 child = fn->left, children |= 2; 1195 1196 if (children == 3 || FIB6_SUBTREE(fn) 1197 #ifdef CONFIG_IPV6_SUBTREES 1198 /* Subtree root (i.e. fn) may have one child */ 1199 || (children && fn->fn_flags & RTN_ROOT) 1200 #endif 1201 ) { 1202 fn->leaf = fib6_find_prefix(net, fn); 1203 #if RT6_DEBUG >= 2 1204 if (!fn->leaf) { 1205 WARN_ON(!fn->leaf); 1206 fn->leaf = net->ipv6.ip6_null_entry; 1207 } 1208 #endif 1209 atomic_inc(&fn->leaf->rt6i_ref); 1210 return fn->parent; 1211 } 1212 1213 pn = fn->parent; 1214 #ifdef CONFIG_IPV6_SUBTREES 1215 if (FIB6_SUBTREE(pn) == fn) { 1216 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1217 FIB6_SUBTREE(pn) = NULL; 1218 nstate = FWS_L; 1219 } else { 1220 WARN_ON(fn->fn_flags & RTN_ROOT); 1221 #endif 1222 if (pn->right == fn) 1223 pn->right = child; 1224 else if (pn->left == fn) 1225 pn->left = child; 1226 #if RT6_DEBUG >= 2 1227 else 1228 WARN_ON(1); 1229 #endif 1230 if (child) 1231 child->parent = pn; 1232 nstate = FWS_R; 1233 #ifdef CONFIG_IPV6_SUBTREES 1234 } 1235 #endif 1236 1237 read_lock(&fib6_walker_lock); 1238 FOR_WALKERS(w) { 1239 if (!child) { 1240 if (w->root == fn) { 1241 w->root = w->node = NULL; 1242 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1243 } else if (w->node == fn) { 1244 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1245 w->node = pn; 1246 w->state = nstate; 1247 } 1248 } else { 1249 if (w->root == fn) { 1250 w->root = child; 1251 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1252 } 1253 if (w->node == fn) { 1254 w->node = child; 1255 if (children&2) { 1256 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1257 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1258 } else { 1259 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1260 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1261 } 1262 } 1263 } 1264 } 1265 read_unlock(&fib6_walker_lock); 1266 1267 node_free(fn); 1268 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1269 return pn; 1270 1271 rt6_release(pn->leaf); 1272 pn->leaf = NULL; 1273 fn = pn; 1274 } 1275 } 1276 1277 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1278 struct nl_info *info) 1279 { 1280 struct fib6_walker_t *w; 1281 struct rt6_info *rt = *rtp; 1282 struct net *net = info->nl_net; 1283 1284 RT6_TRACE("fib6_del_route\n"); 1285 1286 /* Unlink it */ 1287 *rtp = rt->dst.rt6_next; 1288 rt->rt6i_node = NULL; 1289 net->ipv6.rt6_stats->fib_rt_entries--; 1290 net->ipv6.rt6_stats->fib_discarded_routes++; 1291 1292 /* Reset round-robin state, if necessary */ 1293 if (fn->rr_ptr == rt) 1294 fn->rr_ptr = NULL; 1295 1296 /* Remove this entry from other siblings */ 1297 if (rt->rt6i_nsiblings) { 1298 struct rt6_info *sibling, *next_sibling; 1299 1300 list_for_each_entry_safe(sibling, next_sibling, 1301 &rt->rt6i_siblings, rt6i_siblings) 1302 sibling->rt6i_nsiblings--; 1303 rt->rt6i_nsiblings = 0; 1304 list_del_init(&rt->rt6i_siblings); 1305 } 1306 1307 /* Adjust walkers */ 1308 read_lock(&fib6_walker_lock); 1309 FOR_WALKERS(w) { 1310 if (w->state == FWS_C && w->leaf == rt) { 1311 RT6_TRACE("walker %p adjusted by delroute\n", w); 1312 w->leaf = rt->dst.rt6_next; 1313 if (!w->leaf) 1314 w->state = FWS_U; 1315 } 1316 } 1317 read_unlock(&fib6_walker_lock); 1318 1319 rt->dst.rt6_next = NULL; 1320 1321 /* If it was last route, expunge its radix tree node */ 1322 if (!fn->leaf) { 1323 fn->fn_flags &= ~RTN_RTINFO; 1324 net->ipv6.rt6_stats->fib_route_nodes--; 1325 fn = fib6_repair_tree(net, fn); 1326 } 1327 1328 if (atomic_read(&rt->rt6i_ref) != 1) { 1329 /* This route is used as dummy address holder in some split 1330 * nodes. It is not leaked, but it still holds other resources, 1331 * which must be released in time. So, scan ascendant nodes 1332 * and replace dummy references to this route with references 1333 * to still alive ones. 1334 */ 1335 while (fn) { 1336 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 1337 fn->leaf = fib6_find_prefix(net, fn); 1338 atomic_inc(&fn->leaf->rt6i_ref); 1339 rt6_release(rt); 1340 } 1341 fn = fn->parent; 1342 } 1343 /* No more references are possible at this point. */ 1344 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 1345 } 1346 1347 inet6_rt_notify(RTM_DELROUTE, rt, info); 1348 rt6_release(rt); 1349 } 1350 1351 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1352 { 1353 struct net *net = info->nl_net; 1354 struct fib6_node *fn = rt->rt6i_node; 1355 struct rt6_info **rtp; 1356 1357 #if RT6_DEBUG >= 2 1358 if (rt->dst.obsolete > 0) { 1359 WARN_ON(fn != NULL); 1360 return -ENOENT; 1361 } 1362 #endif 1363 if (!fn || rt == net->ipv6.ip6_null_entry) 1364 return -ENOENT; 1365 1366 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1367 1368 if (!(rt->rt6i_flags & RTF_CACHE)) { 1369 struct fib6_node *pn = fn; 1370 #ifdef CONFIG_IPV6_SUBTREES 1371 /* clones of this route might be in another subtree */ 1372 if (rt->rt6i_src.plen) { 1373 while (!(pn->fn_flags & RTN_ROOT)) 1374 pn = pn->parent; 1375 pn = pn->parent; 1376 } 1377 #endif 1378 fib6_prune_clones(info->nl_net, pn, rt); 1379 } 1380 1381 /* 1382 * Walk the leaf entries looking for ourself 1383 */ 1384 1385 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1386 if (*rtp == rt) { 1387 fib6_del_route(fn, rtp, info); 1388 return 0; 1389 } 1390 } 1391 return -ENOENT; 1392 } 1393 1394 /* 1395 * Tree traversal function. 1396 * 1397 * Certainly, it is not interrupt safe. 1398 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1399 * It means, that we can modify tree during walking 1400 * and use this function for garbage collection, clone pruning, 1401 * cleaning tree when a device goes down etc. etc. 1402 * 1403 * It guarantees that every node will be traversed, 1404 * and that it will be traversed only once. 1405 * 1406 * Callback function w->func may return: 1407 * 0 -> continue walking. 1408 * positive value -> walking is suspended (used by tree dumps, 1409 * and probably by gc, if it will be split to several slices) 1410 * negative value -> terminate walking. 1411 * 1412 * The function itself returns: 1413 * 0 -> walk is complete. 1414 * >0 -> walk is incomplete (i.e. suspended) 1415 * <0 -> walk is terminated by an error. 1416 */ 1417 1418 static int fib6_walk_continue(struct fib6_walker_t *w) 1419 { 1420 struct fib6_node *fn, *pn; 1421 1422 for (;;) { 1423 fn = w->node; 1424 if (!fn) 1425 return 0; 1426 1427 if (w->prune && fn != w->root && 1428 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1429 w->state = FWS_C; 1430 w->leaf = fn->leaf; 1431 } 1432 switch (w->state) { 1433 #ifdef CONFIG_IPV6_SUBTREES 1434 case FWS_S: 1435 if (FIB6_SUBTREE(fn)) { 1436 w->node = FIB6_SUBTREE(fn); 1437 continue; 1438 } 1439 w->state = FWS_L; 1440 #endif 1441 case FWS_L: 1442 if (fn->left) { 1443 w->node = fn->left; 1444 w->state = FWS_INIT; 1445 continue; 1446 } 1447 w->state = FWS_R; 1448 case FWS_R: 1449 if (fn->right) { 1450 w->node = fn->right; 1451 w->state = FWS_INIT; 1452 continue; 1453 } 1454 w->state = FWS_C; 1455 w->leaf = fn->leaf; 1456 case FWS_C: 1457 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1458 int err; 1459 1460 if (w->skip) { 1461 w->skip--; 1462 goto skip; 1463 } 1464 1465 err = w->func(w); 1466 if (err) 1467 return err; 1468 1469 w->count++; 1470 continue; 1471 } 1472 skip: 1473 w->state = FWS_U; 1474 case FWS_U: 1475 if (fn == w->root) 1476 return 0; 1477 pn = fn->parent; 1478 w->node = pn; 1479 #ifdef CONFIG_IPV6_SUBTREES 1480 if (FIB6_SUBTREE(pn) == fn) { 1481 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1482 w->state = FWS_L; 1483 continue; 1484 } 1485 #endif 1486 if (pn->left == fn) { 1487 w->state = FWS_R; 1488 continue; 1489 } 1490 if (pn->right == fn) { 1491 w->state = FWS_C; 1492 w->leaf = w->node->leaf; 1493 continue; 1494 } 1495 #if RT6_DEBUG >= 2 1496 WARN_ON(1); 1497 #endif 1498 } 1499 } 1500 } 1501 1502 static int fib6_walk(struct fib6_walker_t *w) 1503 { 1504 int res; 1505 1506 w->state = FWS_INIT; 1507 w->node = w->root; 1508 1509 fib6_walker_link(w); 1510 res = fib6_walk_continue(w); 1511 if (res <= 0) 1512 fib6_walker_unlink(w); 1513 return res; 1514 } 1515 1516 static int fib6_clean_node(struct fib6_walker_t *w) 1517 { 1518 int res; 1519 struct rt6_info *rt; 1520 struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w); 1521 struct nl_info info = { 1522 .nl_net = c->net, 1523 }; 1524 1525 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1526 res = c->func(rt, c->arg); 1527 if (res < 0) { 1528 w->leaf = rt; 1529 res = fib6_del(rt, &info); 1530 if (res) { 1531 #if RT6_DEBUG >= 2 1532 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1533 __func__, rt, rt->rt6i_node, res); 1534 #endif 1535 continue; 1536 } 1537 return 0; 1538 } 1539 WARN_ON(res != 0); 1540 } 1541 w->leaf = rt; 1542 return 0; 1543 } 1544 1545 /* 1546 * Convenient frontend to tree walker. 1547 * 1548 * func is called on each route. 1549 * It may return -1 -> delete this route. 1550 * 0 -> continue walking 1551 * 1552 * prune==1 -> only immediate children of node (certainly, 1553 * ignoring pure split nodes) will be scanned. 1554 */ 1555 1556 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1557 int (*func)(struct rt6_info *, void *arg), 1558 int prune, void *arg) 1559 { 1560 struct fib6_cleaner_t c; 1561 1562 c.w.root = root; 1563 c.w.func = fib6_clean_node; 1564 c.w.prune = prune; 1565 c.w.count = 0; 1566 c.w.skip = 0; 1567 c.func = func; 1568 c.arg = arg; 1569 c.net = net; 1570 1571 fib6_walk(&c.w); 1572 } 1573 1574 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 1575 void *arg) 1576 { 1577 struct fib6_table *table; 1578 struct hlist_head *head; 1579 unsigned int h; 1580 1581 rcu_read_lock(); 1582 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1583 head = &net->ipv6.fib_table_hash[h]; 1584 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1585 write_lock_bh(&table->tb6_lock); 1586 fib6_clean_tree(net, &table->tb6_root, 1587 func, 0, arg); 1588 write_unlock_bh(&table->tb6_lock); 1589 } 1590 } 1591 rcu_read_unlock(); 1592 } 1593 1594 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1595 { 1596 if (rt->rt6i_flags & RTF_CACHE) { 1597 RT6_TRACE("pruning clone %p\n", rt); 1598 return -1; 1599 } 1600 1601 return 0; 1602 } 1603 1604 static void fib6_prune_clones(struct net *net, struct fib6_node *fn, 1605 struct rt6_info *rt) 1606 { 1607 fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt); 1608 } 1609 1610 /* 1611 * Garbage collection 1612 */ 1613 1614 static struct fib6_gc_args 1615 { 1616 int timeout; 1617 int more; 1618 } gc_args; 1619 1620 static int fib6_age(struct rt6_info *rt, void *arg) 1621 { 1622 unsigned long now = jiffies; 1623 1624 /* 1625 * check addrconf expiration here. 1626 * Routes are expired even if they are in use. 1627 * 1628 * Also age clones. Note, that clones are aged out 1629 * only if they are not in use now. 1630 */ 1631 1632 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1633 if (time_after(now, rt->dst.expires)) { 1634 RT6_TRACE("expiring %p\n", rt); 1635 return -1; 1636 } 1637 gc_args.more++; 1638 } else if (rt->rt6i_flags & RTF_CACHE) { 1639 if (atomic_read(&rt->dst.__refcnt) == 0 && 1640 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1641 RT6_TRACE("aging clone %p\n", rt); 1642 return -1; 1643 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1644 struct neighbour *neigh; 1645 __u8 neigh_flags = 0; 1646 1647 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1648 if (neigh) { 1649 neigh_flags = neigh->flags; 1650 neigh_release(neigh); 1651 } 1652 if (!(neigh_flags & NTF_ROUTER)) { 1653 RT6_TRACE("purging route %p via non-router but gateway\n", 1654 rt); 1655 return -1; 1656 } 1657 } 1658 gc_args.more++; 1659 } 1660 1661 return 0; 1662 } 1663 1664 static DEFINE_SPINLOCK(fib6_gc_lock); 1665 1666 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1667 { 1668 unsigned long now; 1669 1670 if (force) { 1671 spin_lock_bh(&fib6_gc_lock); 1672 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1673 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1674 return; 1675 } 1676 gc_args.timeout = expires ? (int)expires : 1677 net->ipv6.sysctl.ip6_rt_gc_interval; 1678 1679 gc_args.more = icmp6_dst_gc(); 1680 1681 fib6_clean_all(net, fib6_age, NULL); 1682 now = jiffies; 1683 net->ipv6.ip6_rt_last_gc = now; 1684 1685 if (gc_args.more) 1686 mod_timer(&net->ipv6.ip6_fib_timer, 1687 round_jiffies(now 1688 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1689 else 1690 del_timer(&net->ipv6.ip6_fib_timer); 1691 spin_unlock_bh(&fib6_gc_lock); 1692 } 1693 1694 static void fib6_gc_timer_cb(unsigned long arg) 1695 { 1696 fib6_run_gc(0, (struct net *)arg, true); 1697 } 1698 1699 static int __net_init fib6_net_init(struct net *net) 1700 { 1701 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1702 1703 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1704 1705 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1706 if (!net->ipv6.rt6_stats) 1707 goto out_timer; 1708 1709 /* Avoid false sharing : Use at least a full cache line */ 1710 size = max_t(size_t, size, L1_CACHE_BYTES); 1711 1712 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1713 if (!net->ipv6.fib_table_hash) 1714 goto out_rt6_stats; 1715 1716 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1717 GFP_KERNEL); 1718 if (!net->ipv6.fib6_main_tbl) 1719 goto out_fib_table_hash; 1720 1721 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1722 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1723 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1724 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1725 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1726 1727 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1728 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1729 GFP_KERNEL); 1730 if (!net->ipv6.fib6_local_tbl) 1731 goto out_fib6_main_tbl; 1732 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1733 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1734 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1735 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1736 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1737 #endif 1738 fib6_tables_init(net); 1739 1740 return 0; 1741 1742 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1743 out_fib6_main_tbl: 1744 kfree(net->ipv6.fib6_main_tbl); 1745 #endif 1746 out_fib_table_hash: 1747 kfree(net->ipv6.fib_table_hash); 1748 out_rt6_stats: 1749 kfree(net->ipv6.rt6_stats); 1750 out_timer: 1751 return -ENOMEM; 1752 } 1753 1754 static void fib6_net_exit(struct net *net) 1755 { 1756 rt6_ifdown(net, NULL); 1757 del_timer_sync(&net->ipv6.ip6_fib_timer); 1758 1759 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1760 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1761 kfree(net->ipv6.fib6_local_tbl); 1762 #endif 1763 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1764 kfree(net->ipv6.fib6_main_tbl); 1765 kfree(net->ipv6.fib_table_hash); 1766 kfree(net->ipv6.rt6_stats); 1767 } 1768 1769 static struct pernet_operations fib6_net_ops = { 1770 .init = fib6_net_init, 1771 .exit = fib6_net_exit, 1772 }; 1773 1774 int __init fib6_init(void) 1775 { 1776 int ret = -ENOMEM; 1777 1778 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1779 sizeof(struct fib6_node), 1780 0, SLAB_HWCACHE_ALIGN, 1781 NULL); 1782 if (!fib6_node_kmem) 1783 goto out; 1784 1785 ret = register_pernet_subsys(&fib6_net_ops); 1786 if (ret) 1787 goto out_kmem_cache_create; 1788 1789 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1790 NULL); 1791 if (ret) 1792 goto out_unregister_subsys; 1793 out: 1794 return ret; 1795 1796 out_unregister_subsys: 1797 unregister_pernet_subsys(&fib6_net_ops); 1798 out_kmem_cache_create: 1799 kmem_cache_destroy(fib6_node_kmem); 1800 goto out; 1801 } 1802 1803 void fib6_gc_cleanup(void) 1804 { 1805 unregister_pernet_subsys(&fib6_net_ops); 1806 kmem_cache_destroy(fib6_node_kmem); 1807 } 1808 1809 #ifdef CONFIG_PROC_FS 1810 1811 struct ipv6_route_iter { 1812 struct seq_net_private p; 1813 struct fib6_walker_t w; 1814 loff_t skip; 1815 struct fib6_table *tbl; 1816 __u32 sernum; 1817 }; 1818 1819 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1820 { 1821 struct rt6_info *rt = v; 1822 struct ipv6_route_iter *iter = seq->private; 1823 1824 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1825 1826 #ifdef CONFIG_IPV6_SUBTREES 1827 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1828 #else 1829 seq_puts(seq, "00000000000000000000000000000000 00 "); 1830 #endif 1831 if (rt->rt6i_flags & RTF_GATEWAY) 1832 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1833 else 1834 seq_puts(seq, "00000000000000000000000000000000"); 1835 1836 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1837 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1838 rt->dst.__use, rt->rt6i_flags, 1839 rt->dst.dev ? rt->dst.dev->name : ""); 1840 iter->w.leaf = NULL; 1841 return 0; 1842 } 1843 1844 static int ipv6_route_yield(struct fib6_walker_t *w) 1845 { 1846 struct ipv6_route_iter *iter = w->args; 1847 1848 if (!iter->skip) 1849 return 1; 1850 1851 do { 1852 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1853 iter->skip--; 1854 if (!iter->skip && iter->w.leaf) 1855 return 1; 1856 } while (iter->w.leaf); 1857 1858 return 0; 1859 } 1860 1861 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1862 { 1863 memset(&iter->w, 0, sizeof(iter->w)); 1864 iter->w.func = ipv6_route_yield; 1865 iter->w.root = &iter->tbl->tb6_root; 1866 iter->w.state = FWS_INIT; 1867 iter->w.node = iter->w.root; 1868 iter->w.args = iter; 1869 iter->sernum = iter->w.root->fn_sernum; 1870 INIT_LIST_HEAD(&iter->w.lh); 1871 fib6_walker_link(&iter->w); 1872 } 1873 1874 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1875 struct net *net) 1876 { 1877 unsigned int h; 1878 struct hlist_node *node; 1879 1880 if (tbl) { 1881 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1882 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1883 } else { 1884 h = 0; 1885 node = NULL; 1886 } 1887 1888 while (!node && h < FIB6_TABLE_HASHSZ) { 1889 node = rcu_dereference_bh( 1890 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 1891 } 1892 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 1893 } 1894 1895 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 1896 { 1897 if (iter->sernum != iter->w.root->fn_sernum) { 1898 iter->sernum = iter->w.root->fn_sernum; 1899 iter->w.state = FWS_INIT; 1900 iter->w.node = iter->w.root; 1901 WARN_ON(iter->w.skip); 1902 iter->w.skip = iter->w.count; 1903 } 1904 } 1905 1906 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1907 { 1908 int r; 1909 struct rt6_info *n; 1910 struct net *net = seq_file_net(seq); 1911 struct ipv6_route_iter *iter = seq->private; 1912 1913 if (!v) 1914 goto iter_table; 1915 1916 n = ((struct rt6_info *)v)->dst.rt6_next; 1917 if (n) { 1918 ++*pos; 1919 return n; 1920 } 1921 1922 iter_table: 1923 ipv6_route_check_sernum(iter); 1924 read_lock(&iter->tbl->tb6_lock); 1925 r = fib6_walk_continue(&iter->w); 1926 read_unlock(&iter->tbl->tb6_lock); 1927 if (r > 0) { 1928 if (v) 1929 ++*pos; 1930 return iter->w.leaf; 1931 } else if (r < 0) { 1932 fib6_walker_unlink(&iter->w); 1933 return NULL; 1934 } 1935 fib6_walker_unlink(&iter->w); 1936 1937 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 1938 if (!iter->tbl) 1939 return NULL; 1940 1941 ipv6_route_seq_setup_walk(iter); 1942 goto iter_table; 1943 } 1944 1945 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 1946 __acquires(RCU_BH) 1947 { 1948 struct net *net = seq_file_net(seq); 1949 struct ipv6_route_iter *iter = seq->private; 1950 1951 rcu_read_lock_bh(); 1952 iter->tbl = ipv6_route_seq_next_table(NULL, net); 1953 iter->skip = *pos; 1954 1955 if (iter->tbl) { 1956 ipv6_route_seq_setup_walk(iter); 1957 return ipv6_route_seq_next(seq, NULL, pos); 1958 } else { 1959 return NULL; 1960 } 1961 } 1962 1963 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 1964 { 1965 struct fib6_walker_t *w = &iter->w; 1966 return w->node && !(w->state == FWS_U && w->node == w->root); 1967 } 1968 1969 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 1970 __releases(RCU_BH) 1971 { 1972 struct ipv6_route_iter *iter = seq->private; 1973 1974 if (ipv6_route_iter_active(iter)) 1975 fib6_walker_unlink(&iter->w); 1976 1977 rcu_read_unlock_bh(); 1978 } 1979 1980 static const struct seq_operations ipv6_route_seq_ops = { 1981 .start = ipv6_route_seq_start, 1982 .next = ipv6_route_seq_next, 1983 .stop = ipv6_route_seq_stop, 1984 .show = ipv6_route_seq_show 1985 }; 1986 1987 int ipv6_route_open(struct inode *inode, struct file *file) 1988 { 1989 return seq_open_net(inode, file, &ipv6_route_seq_ops, 1990 sizeof(struct ipv6_route_iter)); 1991 } 1992 1993 #endif /* CONFIG_PROC_FS */ 1994