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 14 /* 15 * Changes: 16 * Yuji SEKIYA @USAGI: Support default route on router node; 17 * remove ip6_null_entry from the top of 18 * routing table. 19 * Ville Nuorvala: Fixed routing subtrees. 20 */ 21 22 #define pr_fmt(fmt) "IPv6: " fmt 23 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/net.h> 27 #include <linux/route.h> 28 #include <linux/netdevice.h> 29 #include <linux/in6.h> 30 #include <linux/init.h> 31 #include <linux/list.h> 32 #include <linux/slab.h> 33 34 #include <net/ipv6.h> 35 #include <net/ndisc.h> 36 #include <net/addrconf.h> 37 38 #include <net/ip6_fib.h> 39 #include <net/ip6_route.h> 40 41 #define RT6_DEBUG 2 42 43 #if RT6_DEBUG >= 3 44 #define RT6_TRACE(x...) pr_debug(x) 45 #else 46 #define RT6_TRACE(x...) do { ; } while (0) 47 #endif 48 49 static struct kmem_cache * fib6_node_kmem __read_mostly; 50 51 enum fib_walk_state_t 52 { 53 #ifdef CONFIG_IPV6_SUBTREES 54 FWS_S, 55 #endif 56 FWS_L, 57 FWS_R, 58 FWS_C, 59 FWS_U 60 }; 61 62 struct fib6_cleaner_t 63 { 64 struct fib6_walker_t w; 65 struct net *net; 66 int (*func)(struct rt6_info *, void *arg); 67 void *arg; 68 }; 69 70 static DEFINE_RWLOCK(fib6_walker_lock); 71 72 #ifdef CONFIG_IPV6_SUBTREES 73 #define FWS_INIT FWS_S 74 #else 75 #define FWS_INIT FWS_L 76 #endif 77 78 static void fib6_prune_clones(struct net *net, struct fib6_node *fn, 79 struct rt6_info *rt); 80 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 81 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 82 static int fib6_walk(struct fib6_walker_t *w); 83 static int fib6_walk_continue(struct fib6_walker_t *w); 84 85 /* 86 * A routing update causes an increase of the serial number on the 87 * affected subtree. This allows for cached routes to be asynchronously 88 * tested when modifications are made to the destination cache as a 89 * result of redirects, path MTU changes, etc. 90 */ 91 92 static __u32 rt_sernum; 93 94 static void fib6_gc_timer_cb(unsigned long arg); 95 96 static LIST_HEAD(fib6_walkers); 97 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh) 98 99 static inline void fib6_walker_link(struct fib6_walker_t *w) 100 { 101 write_lock_bh(&fib6_walker_lock); 102 list_add(&w->lh, &fib6_walkers); 103 write_unlock_bh(&fib6_walker_lock); 104 } 105 106 static inline void fib6_walker_unlink(struct fib6_walker_t *w) 107 { 108 write_lock_bh(&fib6_walker_lock); 109 list_del(&w->lh); 110 write_unlock_bh(&fib6_walker_lock); 111 } 112 static __inline__ u32 fib6_new_sernum(void) 113 { 114 u32 n = ++rt_sernum; 115 if ((__s32)n <= 0) 116 rt_sernum = n = 1; 117 return n; 118 } 119 120 /* 121 * Auxiliary address test functions for the radix tree. 122 * 123 * These assume a 32bit processor (although it will work on 124 * 64bit processors) 125 */ 126 127 /* 128 * test bit 129 */ 130 #if defined(__LITTLE_ENDIAN) 131 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 132 #else 133 # define BITOP_BE32_SWIZZLE 0 134 #endif 135 136 static __inline__ __be32 addr_bit_set(const void *token, int fn_bit) 137 { 138 const __be32 *addr = token; 139 /* 140 * Here, 141 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 142 * is optimized version of 143 * htonl(1 << ((~fn_bit)&0x1F)) 144 * See include/asm-generic/bitops/le.h. 145 */ 146 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 147 addr[fn_bit >> 5]; 148 } 149 150 static __inline__ struct fib6_node * node_alloc(void) 151 { 152 struct fib6_node *fn; 153 154 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 155 156 return fn; 157 } 158 159 static __inline__ void node_free(struct fib6_node * fn) 160 { 161 kmem_cache_free(fib6_node_kmem, fn); 162 } 163 164 static __inline__ void rt6_release(struct rt6_info *rt) 165 { 166 if (atomic_dec_and_test(&rt->rt6i_ref)) 167 dst_free(&rt->dst); 168 } 169 170 static void fib6_link_table(struct net *net, struct fib6_table *tb) 171 { 172 unsigned int h; 173 174 /* 175 * Initialize table lock at a single place to give lockdep a key, 176 * tables aren't visible prior to being linked to the list. 177 */ 178 rwlock_init(&tb->tb6_lock); 179 180 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 181 182 /* 183 * No protection necessary, this is the only list mutatation 184 * operation, tables never disappear once they exist. 185 */ 186 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 187 } 188 189 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 190 191 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 192 { 193 struct fib6_table *table; 194 195 table = kzalloc(sizeof(*table), GFP_ATOMIC); 196 if (table) { 197 table->tb6_id = id; 198 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 199 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 200 inet_peer_base_init(&table->tb6_peers); 201 } 202 203 return table; 204 } 205 206 struct fib6_table *fib6_new_table(struct net *net, u32 id) 207 { 208 struct fib6_table *tb; 209 210 if (id == 0) 211 id = RT6_TABLE_MAIN; 212 tb = fib6_get_table(net, id); 213 if (tb) 214 return tb; 215 216 tb = fib6_alloc_table(net, id); 217 if (tb) 218 fib6_link_table(net, tb); 219 220 return tb; 221 } 222 223 struct fib6_table *fib6_get_table(struct net *net, u32 id) 224 { 225 struct fib6_table *tb; 226 struct hlist_head *head; 227 struct hlist_node *node; 228 unsigned int h; 229 230 if (id == 0) 231 id = RT6_TABLE_MAIN; 232 h = id & (FIB6_TABLE_HASHSZ - 1); 233 rcu_read_lock(); 234 head = &net->ipv6.fib_table_hash[h]; 235 hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) { 236 if (tb->tb6_id == id) { 237 rcu_read_unlock(); 238 return tb; 239 } 240 } 241 rcu_read_unlock(); 242 243 return NULL; 244 } 245 246 static void __net_init fib6_tables_init(struct net *net) 247 { 248 fib6_link_table(net, net->ipv6.fib6_main_tbl); 249 fib6_link_table(net, net->ipv6.fib6_local_tbl); 250 } 251 #else 252 253 struct fib6_table *fib6_new_table(struct net *net, u32 id) 254 { 255 return fib6_get_table(net, id); 256 } 257 258 struct fib6_table *fib6_get_table(struct net *net, u32 id) 259 { 260 return net->ipv6.fib6_main_tbl; 261 } 262 263 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 264 int flags, pol_lookup_t lookup) 265 { 266 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 267 } 268 269 static void __net_init fib6_tables_init(struct net *net) 270 { 271 fib6_link_table(net, net->ipv6.fib6_main_tbl); 272 } 273 274 #endif 275 276 static int fib6_dump_node(struct fib6_walker_t *w) 277 { 278 int res; 279 struct rt6_info *rt; 280 281 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 282 res = rt6_dump_route(rt, w->args); 283 if (res < 0) { 284 /* Frame is full, suspend walking */ 285 w->leaf = rt; 286 return 1; 287 } 288 WARN_ON(res == 0); 289 } 290 w->leaf = NULL; 291 return 0; 292 } 293 294 static void fib6_dump_end(struct netlink_callback *cb) 295 { 296 struct fib6_walker_t *w = (void*)cb->args[2]; 297 298 if (w) { 299 if (cb->args[4]) { 300 cb->args[4] = 0; 301 fib6_walker_unlink(w); 302 } 303 cb->args[2] = 0; 304 kfree(w); 305 } 306 cb->done = (void*)cb->args[3]; 307 cb->args[1] = 3; 308 } 309 310 static int fib6_dump_done(struct netlink_callback *cb) 311 { 312 fib6_dump_end(cb); 313 return cb->done ? cb->done(cb) : 0; 314 } 315 316 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 317 struct netlink_callback *cb) 318 { 319 struct fib6_walker_t *w; 320 int res; 321 322 w = (void *)cb->args[2]; 323 w->root = &table->tb6_root; 324 325 if (cb->args[4] == 0) { 326 w->count = 0; 327 w->skip = 0; 328 329 read_lock_bh(&table->tb6_lock); 330 res = fib6_walk(w); 331 read_unlock_bh(&table->tb6_lock); 332 if (res > 0) { 333 cb->args[4] = 1; 334 cb->args[5] = w->root->fn_sernum; 335 } 336 } else { 337 if (cb->args[5] != w->root->fn_sernum) { 338 /* Begin at the root if the tree changed */ 339 cb->args[5] = w->root->fn_sernum; 340 w->state = FWS_INIT; 341 w->node = w->root; 342 w->skip = w->count; 343 } else 344 w->skip = 0; 345 346 read_lock_bh(&table->tb6_lock); 347 res = fib6_walk_continue(w); 348 read_unlock_bh(&table->tb6_lock); 349 if (res <= 0) { 350 fib6_walker_unlink(w); 351 cb->args[4] = 0; 352 } 353 } 354 355 return res; 356 } 357 358 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 359 { 360 struct net *net = sock_net(skb->sk); 361 unsigned int h, s_h; 362 unsigned int e = 0, s_e; 363 struct rt6_rtnl_dump_arg arg; 364 struct fib6_walker_t *w; 365 struct fib6_table *tb; 366 struct hlist_node *node; 367 struct hlist_head *head; 368 int res = 0; 369 370 s_h = cb->args[0]; 371 s_e = cb->args[1]; 372 373 w = (void *)cb->args[2]; 374 if (!w) { 375 /* New dump: 376 * 377 * 1. hook callback destructor. 378 */ 379 cb->args[3] = (long)cb->done; 380 cb->done = fib6_dump_done; 381 382 /* 383 * 2. allocate and initialize walker. 384 */ 385 w = kzalloc(sizeof(*w), GFP_ATOMIC); 386 if (!w) 387 return -ENOMEM; 388 w->func = fib6_dump_node; 389 cb->args[2] = (long)w; 390 } 391 392 arg.skb = skb; 393 arg.cb = cb; 394 arg.net = net; 395 w->args = &arg; 396 397 rcu_read_lock(); 398 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 399 e = 0; 400 head = &net->ipv6.fib_table_hash[h]; 401 hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) { 402 if (e < s_e) 403 goto next; 404 res = fib6_dump_table(tb, skb, cb); 405 if (res != 0) 406 goto out; 407 next: 408 e++; 409 } 410 } 411 out: 412 rcu_read_unlock(); 413 cb->args[1] = e; 414 cb->args[0] = h; 415 416 res = res < 0 ? res : skb->len; 417 if (res <= 0) 418 fib6_dump_end(cb); 419 return res; 420 } 421 422 /* 423 * Routing Table 424 * 425 * return the appropriate node for a routing tree "add" operation 426 * by either creating and inserting or by returning an existing 427 * node. 428 */ 429 430 static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr, 431 int addrlen, int plen, 432 int offset, int allow_create, 433 int replace_required) 434 { 435 struct fib6_node *fn, *in, *ln; 436 struct fib6_node *pn = NULL; 437 struct rt6key *key; 438 int bit; 439 __be32 dir = 0; 440 __u32 sernum = fib6_new_sernum(); 441 442 RT6_TRACE("fib6_add_1\n"); 443 444 /* insert node in tree */ 445 446 fn = root; 447 448 do { 449 key = (struct rt6key *)((u8 *)fn->leaf + offset); 450 451 /* 452 * Prefix match 453 */ 454 if (plen < fn->fn_bit || 455 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 456 if (!allow_create) { 457 if (replace_required) { 458 pr_warn("Can't replace route, no match found\n"); 459 return ERR_PTR(-ENOENT); 460 } 461 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 462 } 463 goto insert_above; 464 } 465 466 /* 467 * Exact match ? 468 */ 469 470 if (plen == fn->fn_bit) { 471 /* clean up an intermediate node */ 472 if (!(fn->fn_flags & RTN_RTINFO)) { 473 rt6_release(fn->leaf); 474 fn->leaf = NULL; 475 } 476 477 fn->fn_sernum = sernum; 478 479 return fn; 480 } 481 482 /* 483 * We have more bits to go 484 */ 485 486 /* Try to walk down on tree. */ 487 fn->fn_sernum = sernum; 488 dir = addr_bit_set(addr, fn->fn_bit); 489 pn = fn; 490 fn = dir ? fn->right: fn->left; 491 } while (fn); 492 493 if (!allow_create) { 494 /* We should not create new node because 495 * NLM_F_REPLACE was specified without NLM_F_CREATE 496 * I assume it is safe to require NLM_F_CREATE when 497 * REPLACE flag is used! Later we may want to remove the 498 * check for replace_required, because according 499 * to netlink specification, NLM_F_CREATE 500 * MUST be specified if new route is created. 501 * That would keep IPv6 consistent with IPv4 502 */ 503 if (replace_required) { 504 pr_warn("Can't replace route, no match found\n"); 505 return ERR_PTR(-ENOENT); 506 } 507 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 508 } 509 /* 510 * We walked to the bottom of tree. 511 * Create new leaf node without children. 512 */ 513 514 ln = node_alloc(); 515 516 if (!ln) 517 return ERR_PTR(-ENOMEM); 518 ln->fn_bit = plen; 519 520 ln->parent = pn; 521 ln->fn_sernum = sernum; 522 523 if (dir) 524 pn->right = ln; 525 else 526 pn->left = ln; 527 528 return ln; 529 530 531 insert_above: 532 /* 533 * split since we don't have a common prefix anymore or 534 * we have a less significant route. 535 * we've to insert an intermediate node on the list 536 * this new node will point to the one we need to create 537 * and the current 538 */ 539 540 pn = fn->parent; 541 542 /* find 1st bit in difference between the 2 addrs. 543 544 See comment in __ipv6_addr_diff: bit may be an invalid value, 545 but if it is >= plen, the value is ignored in any case. 546 */ 547 548 bit = __ipv6_addr_diff(addr, &key->addr, addrlen); 549 550 /* 551 * (intermediate)[in] 552 * / \ 553 * (new leaf node)[ln] (old node)[fn] 554 */ 555 if (plen > bit) { 556 in = node_alloc(); 557 ln = node_alloc(); 558 559 if (!in || !ln) { 560 if (in) 561 node_free(in); 562 if (ln) 563 node_free(ln); 564 return ERR_PTR(-ENOMEM); 565 } 566 567 /* 568 * new intermediate node. 569 * RTN_RTINFO will 570 * be off since that an address that chooses one of 571 * the branches would not match less specific routes 572 * in the other branch 573 */ 574 575 in->fn_bit = bit; 576 577 in->parent = pn; 578 in->leaf = fn->leaf; 579 atomic_inc(&in->leaf->rt6i_ref); 580 581 in->fn_sernum = sernum; 582 583 /* update parent pointer */ 584 if (dir) 585 pn->right = in; 586 else 587 pn->left = in; 588 589 ln->fn_bit = plen; 590 591 ln->parent = in; 592 fn->parent = in; 593 594 ln->fn_sernum = sernum; 595 596 if (addr_bit_set(addr, bit)) { 597 in->right = ln; 598 in->left = fn; 599 } else { 600 in->left = ln; 601 in->right = fn; 602 } 603 } else { /* plen <= bit */ 604 605 /* 606 * (new leaf node)[ln] 607 * / \ 608 * (old node)[fn] NULL 609 */ 610 611 ln = node_alloc(); 612 613 if (!ln) 614 return ERR_PTR(-ENOMEM); 615 616 ln->fn_bit = plen; 617 618 ln->parent = pn; 619 620 ln->fn_sernum = sernum; 621 622 if (dir) 623 pn->right = ln; 624 else 625 pn->left = ln; 626 627 if (addr_bit_set(&key->addr, plen)) 628 ln->right = fn; 629 else 630 ln->left = fn; 631 632 fn->parent = ln; 633 } 634 return ln; 635 } 636 637 /* 638 * Insert routing information in a node. 639 */ 640 641 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 642 struct nl_info *info) 643 { 644 struct rt6_info *iter = NULL; 645 struct rt6_info **ins; 646 int replace = (info->nlh && 647 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 648 int add = (!info->nlh || 649 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 650 int found = 0; 651 652 ins = &fn->leaf; 653 654 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 655 /* 656 * Search for duplicates 657 */ 658 659 if (iter->rt6i_metric == rt->rt6i_metric) { 660 /* 661 * Same priority level 662 */ 663 if (info->nlh && 664 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 665 return -EEXIST; 666 if (replace) { 667 found++; 668 break; 669 } 670 671 if (iter->dst.dev == rt->dst.dev && 672 iter->rt6i_idev == rt->rt6i_idev && 673 ipv6_addr_equal(&iter->rt6i_gateway, 674 &rt->rt6i_gateway)) { 675 if (!(iter->rt6i_flags & RTF_EXPIRES)) 676 return -EEXIST; 677 if (!(rt->rt6i_flags & RTF_EXPIRES)) 678 rt6_clean_expires(iter); 679 else 680 rt6_set_expires(iter, rt->dst.expires); 681 return -EEXIST; 682 } 683 } 684 685 if (iter->rt6i_metric > rt->rt6i_metric) 686 break; 687 688 ins = &iter->dst.rt6_next; 689 } 690 691 /* Reset round-robin state, if necessary */ 692 if (ins == &fn->leaf) 693 fn->rr_ptr = NULL; 694 695 /* 696 * insert node 697 */ 698 if (!replace) { 699 if (!add) 700 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 701 702 add: 703 rt->dst.rt6_next = iter; 704 *ins = rt; 705 rt->rt6i_node = fn; 706 atomic_inc(&rt->rt6i_ref); 707 inet6_rt_notify(RTM_NEWROUTE, rt, info); 708 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 709 710 if (!(fn->fn_flags & RTN_RTINFO)) { 711 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 712 fn->fn_flags |= RTN_RTINFO; 713 } 714 715 } else { 716 if (!found) { 717 if (add) 718 goto add; 719 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 720 return -ENOENT; 721 } 722 *ins = rt; 723 rt->rt6i_node = fn; 724 rt->dst.rt6_next = iter->dst.rt6_next; 725 atomic_inc(&rt->rt6i_ref); 726 inet6_rt_notify(RTM_NEWROUTE, rt, info); 727 rt6_release(iter); 728 if (!(fn->fn_flags & RTN_RTINFO)) { 729 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 730 fn->fn_flags |= RTN_RTINFO; 731 } 732 } 733 734 return 0; 735 } 736 737 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt) 738 { 739 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 740 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 741 mod_timer(&net->ipv6.ip6_fib_timer, 742 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 743 } 744 745 void fib6_force_start_gc(struct net *net) 746 { 747 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 748 mod_timer(&net->ipv6.ip6_fib_timer, 749 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 750 } 751 752 /* 753 * Add routing information to the routing tree. 754 * <destination addr>/<source addr> 755 * with source addr info in sub-trees 756 */ 757 758 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info) 759 { 760 struct fib6_node *fn, *pn = NULL; 761 int err = -ENOMEM; 762 int allow_create = 1; 763 int replace_required = 0; 764 765 if (info->nlh) { 766 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 767 allow_create = 0; 768 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 769 replace_required = 1; 770 } 771 if (!allow_create && !replace_required) 772 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 773 774 fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr), 775 rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst), 776 allow_create, replace_required); 777 778 if (IS_ERR(fn)) { 779 err = PTR_ERR(fn); 780 goto out; 781 } 782 783 pn = fn; 784 785 #ifdef CONFIG_IPV6_SUBTREES 786 if (rt->rt6i_src.plen) { 787 struct fib6_node *sn; 788 789 if (!fn->subtree) { 790 struct fib6_node *sfn; 791 792 /* 793 * Create subtree. 794 * 795 * fn[main tree] 796 * | 797 * sfn[subtree root] 798 * \ 799 * sn[new leaf node] 800 */ 801 802 /* Create subtree root node */ 803 sfn = node_alloc(); 804 if (!sfn) 805 goto st_failure; 806 807 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 808 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 809 sfn->fn_flags = RTN_ROOT; 810 sfn->fn_sernum = fib6_new_sernum(); 811 812 /* Now add the first leaf node to new subtree */ 813 814 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 815 sizeof(struct in6_addr), rt->rt6i_src.plen, 816 offsetof(struct rt6_info, rt6i_src), 817 allow_create, replace_required); 818 819 if (IS_ERR(sn)) { 820 /* If it is failed, discard just allocated 821 root, and then (in st_failure) stale node 822 in main tree. 823 */ 824 node_free(sfn); 825 err = PTR_ERR(sn); 826 goto st_failure; 827 } 828 829 /* Now link new subtree to main tree */ 830 sfn->parent = fn; 831 fn->subtree = sfn; 832 } else { 833 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 834 sizeof(struct in6_addr), rt->rt6i_src.plen, 835 offsetof(struct rt6_info, rt6i_src), 836 allow_create, replace_required); 837 838 if (IS_ERR(sn)) { 839 err = PTR_ERR(sn); 840 goto st_failure; 841 } 842 } 843 844 if (!fn->leaf) { 845 fn->leaf = rt; 846 atomic_inc(&rt->rt6i_ref); 847 } 848 fn = sn; 849 } 850 #endif 851 852 err = fib6_add_rt2node(fn, rt, info); 853 if (!err) { 854 fib6_start_gc(info->nl_net, rt); 855 if (!(rt->rt6i_flags & RTF_CACHE)) 856 fib6_prune_clones(info->nl_net, pn, rt); 857 } 858 859 out: 860 if (err) { 861 #ifdef CONFIG_IPV6_SUBTREES 862 /* 863 * If fib6_add_1 has cleared the old leaf pointer in the 864 * super-tree leaf node we have to find a new one for it. 865 */ 866 if (pn != fn && pn->leaf == rt) { 867 pn->leaf = NULL; 868 atomic_dec(&rt->rt6i_ref); 869 } 870 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 871 pn->leaf = fib6_find_prefix(info->nl_net, pn); 872 #if RT6_DEBUG >= 2 873 if (!pn->leaf) { 874 WARN_ON(pn->leaf == NULL); 875 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 876 } 877 #endif 878 atomic_inc(&pn->leaf->rt6i_ref); 879 } 880 #endif 881 dst_free(&rt->dst); 882 } 883 return err; 884 885 #ifdef CONFIG_IPV6_SUBTREES 886 /* Subtree creation failed, probably main tree node 887 is orphan. If it is, shoot it. 888 */ 889 st_failure: 890 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 891 fib6_repair_tree(info->nl_net, fn); 892 dst_free(&rt->dst); 893 return err; 894 #endif 895 } 896 897 /* 898 * Routing tree lookup 899 * 900 */ 901 902 struct lookup_args { 903 int offset; /* key offset on rt6_info */ 904 const struct in6_addr *addr; /* search key */ 905 }; 906 907 static struct fib6_node * fib6_lookup_1(struct fib6_node *root, 908 struct lookup_args *args) 909 { 910 struct fib6_node *fn; 911 __be32 dir; 912 913 if (unlikely(args->offset == 0)) 914 return NULL; 915 916 /* 917 * Descend on a tree 918 */ 919 920 fn = root; 921 922 for (;;) { 923 struct fib6_node *next; 924 925 dir = addr_bit_set(args->addr, fn->fn_bit); 926 927 next = dir ? fn->right : fn->left; 928 929 if (next) { 930 fn = next; 931 continue; 932 } 933 break; 934 } 935 936 while (fn) { 937 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 938 struct rt6key *key; 939 940 key = (struct rt6key *) ((u8 *) fn->leaf + 941 args->offset); 942 943 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 944 #ifdef CONFIG_IPV6_SUBTREES 945 if (fn->subtree) 946 fn = fib6_lookup_1(fn->subtree, args + 1); 947 #endif 948 if (!fn || fn->fn_flags & RTN_RTINFO) 949 return fn; 950 } 951 } 952 953 if (fn->fn_flags & RTN_ROOT) 954 break; 955 956 fn = fn->parent; 957 } 958 959 return NULL; 960 } 961 962 struct fib6_node * fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 963 const struct in6_addr *saddr) 964 { 965 struct fib6_node *fn; 966 struct lookup_args args[] = { 967 { 968 .offset = offsetof(struct rt6_info, rt6i_dst), 969 .addr = daddr, 970 }, 971 #ifdef CONFIG_IPV6_SUBTREES 972 { 973 .offset = offsetof(struct rt6_info, rt6i_src), 974 .addr = saddr, 975 }, 976 #endif 977 { 978 .offset = 0, /* sentinel */ 979 } 980 }; 981 982 fn = fib6_lookup_1(root, daddr ? args : args + 1); 983 if (!fn || fn->fn_flags & RTN_TL_ROOT) 984 fn = root; 985 986 return fn; 987 } 988 989 /* 990 * Get node with specified destination prefix (and source prefix, 991 * if subtrees are used) 992 */ 993 994 995 static struct fib6_node * fib6_locate_1(struct fib6_node *root, 996 const struct in6_addr *addr, 997 int plen, int offset) 998 { 999 struct fib6_node *fn; 1000 1001 for (fn = root; fn ; ) { 1002 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1003 1004 /* 1005 * Prefix match 1006 */ 1007 if (plen < fn->fn_bit || 1008 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1009 return NULL; 1010 1011 if (plen == fn->fn_bit) 1012 return fn; 1013 1014 /* 1015 * We have more bits to go 1016 */ 1017 if (addr_bit_set(addr, fn->fn_bit)) 1018 fn = fn->right; 1019 else 1020 fn = fn->left; 1021 } 1022 return NULL; 1023 } 1024 1025 struct fib6_node * fib6_locate(struct fib6_node *root, 1026 const struct in6_addr *daddr, int dst_len, 1027 const struct in6_addr *saddr, int src_len) 1028 { 1029 struct fib6_node *fn; 1030 1031 fn = fib6_locate_1(root, daddr, dst_len, 1032 offsetof(struct rt6_info, rt6i_dst)); 1033 1034 #ifdef CONFIG_IPV6_SUBTREES 1035 if (src_len) { 1036 WARN_ON(saddr == NULL); 1037 if (fn && fn->subtree) 1038 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1039 offsetof(struct rt6_info, rt6i_src)); 1040 } 1041 #endif 1042 1043 if (fn && fn->fn_flags & RTN_RTINFO) 1044 return fn; 1045 1046 return NULL; 1047 } 1048 1049 1050 /* 1051 * Deletion 1052 * 1053 */ 1054 1055 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1056 { 1057 if (fn->fn_flags & RTN_ROOT) 1058 return net->ipv6.ip6_null_entry; 1059 1060 while (fn) { 1061 if (fn->left) 1062 return fn->left->leaf; 1063 if (fn->right) 1064 return fn->right->leaf; 1065 1066 fn = FIB6_SUBTREE(fn); 1067 } 1068 return NULL; 1069 } 1070 1071 /* 1072 * Called to trim the tree of intermediate nodes when possible. "fn" 1073 * is the node we want to try and remove. 1074 */ 1075 1076 static struct fib6_node *fib6_repair_tree(struct net *net, 1077 struct fib6_node *fn) 1078 { 1079 int children; 1080 int nstate; 1081 struct fib6_node *child, *pn; 1082 struct fib6_walker_t *w; 1083 int iter = 0; 1084 1085 for (;;) { 1086 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1087 iter++; 1088 1089 WARN_ON(fn->fn_flags & RTN_RTINFO); 1090 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1091 WARN_ON(fn->leaf != NULL); 1092 1093 children = 0; 1094 child = NULL; 1095 if (fn->right) child = fn->right, children |= 1; 1096 if (fn->left) child = fn->left, children |= 2; 1097 1098 if (children == 3 || FIB6_SUBTREE(fn) 1099 #ifdef CONFIG_IPV6_SUBTREES 1100 /* Subtree root (i.e. fn) may have one child */ 1101 || (children && fn->fn_flags & RTN_ROOT) 1102 #endif 1103 ) { 1104 fn->leaf = fib6_find_prefix(net, fn); 1105 #if RT6_DEBUG >= 2 1106 if (!fn->leaf) { 1107 WARN_ON(!fn->leaf); 1108 fn->leaf = net->ipv6.ip6_null_entry; 1109 } 1110 #endif 1111 atomic_inc(&fn->leaf->rt6i_ref); 1112 return fn->parent; 1113 } 1114 1115 pn = fn->parent; 1116 #ifdef CONFIG_IPV6_SUBTREES 1117 if (FIB6_SUBTREE(pn) == fn) { 1118 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1119 FIB6_SUBTREE(pn) = NULL; 1120 nstate = FWS_L; 1121 } else { 1122 WARN_ON(fn->fn_flags & RTN_ROOT); 1123 #endif 1124 if (pn->right == fn) pn->right = child; 1125 else if (pn->left == fn) pn->left = child; 1126 #if RT6_DEBUG >= 2 1127 else 1128 WARN_ON(1); 1129 #endif 1130 if (child) 1131 child->parent = pn; 1132 nstate = FWS_R; 1133 #ifdef CONFIG_IPV6_SUBTREES 1134 } 1135 #endif 1136 1137 read_lock(&fib6_walker_lock); 1138 FOR_WALKERS(w) { 1139 if (!child) { 1140 if (w->root == fn) { 1141 w->root = w->node = NULL; 1142 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1143 } else if (w->node == fn) { 1144 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1145 w->node = pn; 1146 w->state = nstate; 1147 } 1148 } else { 1149 if (w->root == fn) { 1150 w->root = child; 1151 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1152 } 1153 if (w->node == fn) { 1154 w->node = child; 1155 if (children&2) { 1156 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1157 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT; 1158 } else { 1159 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1160 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT; 1161 } 1162 } 1163 } 1164 } 1165 read_unlock(&fib6_walker_lock); 1166 1167 node_free(fn); 1168 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1169 return pn; 1170 1171 rt6_release(pn->leaf); 1172 pn->leaf = NULL; 1173 fn = pn; 1174 } 1175 } 1176 1177 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1178 struct nl_info *info) 1179 { 1180 struct fib6_walker_t *w; 1181 struct rt6_info *rt = *rtp; 1182 struct net *net = info->nl_net; 1183 1184 RT6_TRACE("fib6_del_route\n"); 1185 1186 /* Unlink it */ 1187 *rtp = rt->dst.rt6_next; 1188 rt->rt6i_node = NULL; 1189 net->ipv6.rt6_stats->fib_rt_entries--; 1190 net->ipv6.rt6_stats->fib_discarded_routes++; 1191 1192 /* Reset round-robin state, if necessary */ 1193 if (fn->rr_ptr == rt) 1194 fn->rr_ptr = NULL; 1195 1196 /* Adjust walkers */ 1197 read_lock(&fib6_walker_lock); 1198 FOR_WALKERS(w) { 1199 if (w->state == FWS_C && w->leaf == rt) { 1200 RT6_TRACE("walker %p adjusted by delroute\n", w); 1201 w->leaf = rt->dst.rt6_next; 1202 if (!w->leaf) 1203 w->state = FWS_U; 1204 } 1205 } 1206 read_unlock(&fib6_walker_lock); 1207 1208 rt->dst.rt6_next = NULL; 1209 1210 /* If it was last route, expunge its radix tree node */ 1211 if (!fn->leaf) { 1212 fn->fn_flags &= ~RTN_RTINFO; 1213 net->ipv6.rt6_stats->fib_route_nodes--; 1214 fn = fib6_repair_tree(net, fn); 1215 } 1216 1217 if (atomic_read(&rt->rt6i_ref) != 1) { 1218 /* This route is used as dummy address holder in some split 1219 * nodes. It is not leaked, but it still holds other resources, 1220 * which must be released in time. So, scan ascendant nodes 1221 * and replace dummy references to this route with references 1222 * to still alive ones. 1223 */ 1224 while (fn) { 1225 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 1226 fn->leaf = fib6_find_prefix(net, fn); 1227 atomic_inc(&fn->leaf->rt6i_ref); 1228 rt6_release(rt); 1229 } 1230 fn = fn->parent; 1231 } 1232 /* No more references are possible at this point. */ 1233 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 1234 } 1235 1236 inet6_rt_notify(RTM_DELROUTE, rt, info); 1237 rt6_release(rt); 1238 } 1239 1240 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1241 { 1242 struct net *net = info->nl_net; 1243 struct fib6_node *fn = rt->rt6i_node; 1244 struct rt6_info **rtp; 1245 1246 #if RT6_DEBUG >= 2 1247 if (rt->dst.obsolete>0) { 1248 WARN_ON(fn != NULL); 1249 return -ENOENT; 1250 } 1251 #endif 1252 if (!fn || rt == net->ipv6.ip6_null_entry) 1253 return -ENOENT; 1254 1255 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1256 1257 if (!(rt->rt6i_flags & RTF_CACHE)) { 1258 struct fib6_node *pn = fn; 1259 #ifdef CONFIG_IPV6_SUBTREES 1260 /* clones of this route might be in another subtree */ 1261 if (rt->rt6i_src.plen) { 1262 while (!(pn->fn_flags & RTN_ROOT)) 1263 pn = pn->parent; 1264 pn = pn->parent; 1265 } 1266 #endif 1267 fib6_prune_clones(info->nl_net, pn, rt); 1268 } 1269 1270 /* 1271 * Walk the leaf entries looking for ourself 1272 */ 1273 1274 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1275 if (*rtp == rt) { 1276 fib6_del_route(fn, rtp, info); 1277 return 0; 1278 } 1279 } 1280 return -ENOENT; 1281 } 1282 1283 /* 1284 * Tree traversal function. 1285 * 1286 * Certainly, it is not interrupt safe. 1287 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1288 * It means, that we can modify tree during walking 1289 * and use this function for garbage collection, clone pruning, 1290 * cleaning tree when a device goes down etc. etc. 1291 * 1292 * It guarantees that every node will be traversed, 1293 * and that it will be traversed only once. 1294 * 1295 * Callback function w->func may return: 1296 * 0 -> continue walking. 1297 * positive value -> walking is suspended (used by tree dumps, 1298 * and probably by gc, if it will be split to several slices) 1299 * negative value -> terminate walking. 1300 * 1301 * The function itself returns: 1302 * 0 -> walk is complete. 1303 * >0 -> walk is incomplete (i.e. suspended) 1304 * <0 -> walk is terminated by an error. 1305 */ 1306 1307 static int fib6_walk_continue(struct fib6_walker_t *w) 1308 { 1309 struct fib6_node *fn, *pn; 1310 1311 for (;;) { 1312 fn = w->node; 1313 if (!fn) 1314 return 0; 1315 1316 if (w->prune && fn != w->root && 1317 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1318 w->state = FWS_C; 1319 w->leaf = fn->leaf; 1320 } 1321 switch (w->state) { 1322 #ifdef CONFIG_IPV6_SUBTREES 1323 case FWS_S: 1324 if (FIB6_SUBTREE(fn)) { 1325 w->node = FIB6_SUBTREE(fn); 1326 continue; 1327 } 1328 w->state = FWS_L; 1329 #endif 1330 case FWS_L: 1331 if (fn->left) { 1332 w->node = fn->left; 1333 w->state = FWS_INIT; 1334 continue; 1335 } 1336 w->state = FWS_R; 1337 case FWS_R: 1338 if (fn->right) { 1339 w->node = fn->right; 1340 w->state = FWS_INIT; 1341 continue; 1342 } 1343 w->state = FWS_C; 1344 w->leaf = fn->leaf; 1345 case FWS_C: 1346 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1347 int err; 1348 1349 if (w->skip) { 1350 w->skip--; 1351 continue; 1352 } 1353 1354 err = w->func(w); 1355 if (err) 1356 return err; 1357 1358 w->count++; 1359 continue; 1360 } 1361 w->state = FWS_U; 1362 case FWS_U: 1363 if (fn == w->root) 1364 return 0; 1365 pn = fn->parent; 1366 w->node = pn; 1367 #ifdef CONFIG_IPV6_SUBTREES 1368 if (FIB6_SUBTREE(pn) == fn) { 1369 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1370 w->state = FWS_L; 1371 continue; 1372 } 1373 #endif 1374 if (pn->left == fn) { 1375 w->state = FWS_R; 1376 continue; 1377 } 1378 if (pn->right == fn) { 1379 w->state = FWS_C; 1380 w->leaf = w->node->leaf; 1381 continue; 1382 } 1383 #if RT6_DEBUG >= 2 1384 WARN_ON(1); 1385 #endif 1386 } 1387 } 1388 } 1389 1390 static int fib6_walk(struct fib6_walker_t *w) 1391 { 1392 int res; 1393 1394 w->state = FWS_INIT; 1395 w->node = w->root; 1396 1397 fib6_walker_link(w); 1398 res = fib6_walk_continue(w); 1399 if (res <= 0) 1400 fib6_walker_unlink(w); 1401 return res; 1402 } 1403 1404 static int fib6_clean_node(struct fib6_walker_t *w) 1405 { 1406 int res; 1407 struct rt6_info *rt; 1408 struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w); 1409 struct nl_info info = { 1410 .nl_net = c->net, 1411 }; 1412 1413 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1414 res = c->func(rt, c->arg); 1415 if (res < 0) { 1416 w->leaf = rt; 1417 res = fib6_del(rt, &info); 1418 if (res) { 1419 #if RT6_DEBUG >= 2 1420 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1421 __func__, rt, rt->rt6i_node, res); 1422 #endif 1423 continue; 1424 } 1425 return 0; 1426 } 1427 WARN_ON(res != 0); 1428 } 1429 w->leaf = rt; 1430 return 0; 1431 } 1432 1433 /* 1434 * Convenient frontend to tree walker. 1435 * 1436 * func is called on each route. 1437 * It may return -1 -> delete this route. 1438 * 0 -> continue walking 1439 * 1440 * prune==1 -> only immediate children of node (certainly, 1441 * ignoring pure split nodes) will be scanned. 1442 */ 1443 1444 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1445 int (*func)(struct rt6_info *, void *arg), 1446 int prune, void *arg) 1447 { 1448 struct fib6_cleaner_t c; 1449 1450 c.w.root = root; 1451 c.w.func = fib6_clean_node; 1452 c.w.prune = prune; 1453 c.w.count = 0; 1454 c.w.skip = 0; 1455 c.func = func; 1456 c.arg = arg; 1457 c.net = net; 1458 1459 fib6_walk(&c.w); 1460 } 1461 1462 void fib6_clean_all_ro(struct net *net, int (*func)(struct rt6_info *, void *arg), 1463 int prune, void *arg) 1464 { 1465 struct fib6_table *table; 1466 struct hlist_node *node; 1467 struct hlist_head *head; 1468 unsigned int h; 1469 1470 rcu_read_lock(); 1471 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1472 head = &net->ipv6.fib_table_hash[h]; 1473 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) { 1474 read_lock_bh(&table->tb6_lock); 1475 fib6_clean_tree(net, &table->tb6_root, 1476 func, prune, arg); 1477 read_unlock_bh(&table->tb6_lock); 1478 } 1479 } 1480 rcu_read_unlock(); 1481 } 1482 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 1483 int prune, void *arg) 1484 { 1485 struct fib6_table *table; 1486 struct hlist_node *node; 1487 struct hlist_head *head; 1488 unsigned int h; 1489 1490 rcu_read_lock(); 1491 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1492 head = &net->ipv6.fib_table_hash[h]; 1493 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) { 1494 write_lock_bh(&table->tb6_lock); 1495 fib6_clean_tree(net, &table->tb6_root, 1496 func, prune, arg); 1497 write_unlock_bh(&table->tb6_lock); 1498 } 1499 } 1500 rcu_read_unlock(); 1501 } 1502 1503 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1504 { 1505 if (rt->rt6i_flags & RTF_CACHE) { 1506 RT6_TRACE("pruning clone %p\n", rt); 1507 return -1; 1508 } 1509 1510 return 0; 1511 } 1512 1513 static void fib6_prune_clones(struct net *net, struct fib6_node *fn, 1514 struct rt6_info *rt) 1515 { 1516 fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt); 1517 } 1518 1519 /* 1520 * Garbage collection 1521 */ 1522 1523 static struct fib6_gc_args 1524 { 1525 int timeout; 1526 int more; 1527 } gc_args; 1528 1529 static int fib6_age(struct rt6_info *rt, void *arg) 1530 { 1531 unsigned long now = jiffies; 1532 1533 /* 1534 * check addrconf expiration here. 1535 * Routes are expired even if they are in use. 1536 * 1537 * Also age clones. Note, that clones are aged out 1538 * only if they are not in use now. 1539 */ 1540 1541 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1542 if (time_after(now, rt->dst.expires)) { 1543 RT6_TRACE("expiring %p\n", rt); 1544 return -1; 1545 } 1546 gc_args.more++; 1547 } else if (rt->rt6i_flags & RTF_CACHE) { 1548 if (atomic_read(&rt->dst.__refcnt) == 0 && 1549 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1550 RT6_TRACE("aging clone %p\n", rt); 1551 return -1; 1552 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1553 struct neighbour *neigh; 1554 __u8 neigh_flags = 0; 1555 1556 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1557 if (neigh) { 1558 neigh_flags = neigh->flags; 1559 neigh_release(neigh); 1560 } 1561 if (!(neigh_flags & NTF_ROUTER)) { 1562 RT6_TRACE("purging route %p via non-router but gateway\n", 1563 rt); 1564 return -1; 1565 } 1566 } 1567 gc_args.more++; 1568 } 1569 1570 return 0; 1571 } 1572 1573 static DEFINE_SPINLOCK(fib6_gc_lock); 1574 1575 void fib6_run_gc(unsigned long expires, struct net *net) 1576 { 1577 if (expires != ~0UL) { 1578 spin_lock_bh(&fib6_gc_lock); 1579 gc_args.timeout = expires ? (int)expires : 1580 net->ipv6.sysctl.ip6_rt_gc_interval; 1581 } else { 1582 if (!spin_trylock_bh(&fib6_gc_lock)) { 1583 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1584 return; 1585 } 1586 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval; 1587 } 1588 1589 gc_args.more = icmp6_dst_gc(); 1590 1591 fib6_clean_all(net, fib6_age, 0, NULL); 1592 1593 if (gc_args.more) 1594 mod_timer(&net->ipv6.ip6_fib_timer, 1595 round_jiffies(jiffies 1596 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1597 else 1598 del_timer(&net->ipv6.ip6_fib_timer); 1599 spin_unlock_bh(&fib6_gc_lock); 1600 } 1601 1602 static void fib6_gc_timer_cb(unsigned long arg) 1603 { 1604 fib6_run_gc(0, (struct net *)arg); 1605 } 1606 1607 static int __net_init fib6_net_init(struct net *net) 1608 { 1609 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1610 1611 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1612 1613 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1614 if (!net->ipv6.rt6_stats) 1615 goto out_timer; 1616 1617 /* Avoid false sharing : Use at least a full cache line */ 1618 size = max_t(size_t, size, L1_CACHE_BYTES); 1619 1620 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1621 if (!net->ipv6.fib_table_hash) 1622 goto out_rt6_stats; 1623 1624 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1625 GFP_KERNEL); 1626 if (!net->ipv6.fib6_main_tbl) 1627 goto out_fib_table_hash; 1628 1629 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1630 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1631 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1632 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1633 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1634 1635 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1636 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1637 GFP_KERNEL); 1638 if (!net->ipv6.fib6_local_tbl) 1639 goto out_fib6_main_tbl; 1640 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1641 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1642 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1643 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1644 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1645 #endif 1646 fib6_tables_init(net); 1647 1648 return 0; 1649 1650 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1651 out_fib6_main_tbl: 1652 kfree(net->ipv6.fib6_main_tbl); 1653 #endif 1654 out_fib_table_hash: 1655 kfree(net->ipv6.fib_table_hash); 1656 out_rt6_stats: 1657 kfree(net->ipv6.rt6_stats); 1658 out_timer: 1659 return -ENOMEM; 1660 } 1661 1662 static void fib6_net_exit(struct net *net) 1663 { 1664 rt6_ifdown(net, NULL); 1665 del_timer_sync(&net->ipv6.ip6_fib_timer); 1666 1667 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1668 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1669 kfree(net->ipv6.fib6_local_tbl); 1670 #endif 1671 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1672 kfree(net->ipv6.fib6_main_tbl); 1673 kfree(net->ipv6.fib_table_hash); 1674 kfree(net->ipv6.rt6_stats); 1675 } 1676 1677 static struct pernet_operations fib6_net_ops = { 1678 .init = fib6_net_init, 1679 .exit = fib6_net_exit, 1680 }; 1681 1682 int __init fib6_init(void) 1683 { 1684 int ret = -ENOMEM; 1685 1686 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1687 sizeof(struct fib6_node), 1688 0, SLAB_HWCACHE_ALIGN, 1689 NULL); 1690 if (!fib6_node_kmem) 1691 goto out; 1692 1693 ret = register_pernet_subsys(&fib6_net_ops); 1694 if (ret) 1695 goto out_kmem_cache_create; 1696 1697 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1698 NULL); 1699 if (ret) 1700 goto out_unregister_subsys; 1701 out: 1702 return ret; 1703 1704 out_unregister_subsys: 1705 unregister_pernet_subsys(&fib6_net_ops); 1706 out_kmem_cache_create: 1707 kmem_cache_destroy(fib6_node_kmem); 1708 goto out; 1709 } 1710 1711 void fib6_gc_cleanup(void) 1712 { 1713 unregister_pernet_subsys(&fib6_net_ops); 1714 kmem_cache_destroy(fib6_node_kmem); 1715 } 1716