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