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 struct fib6_cleaner { 50 struct fib6_walker w; 51 struct net *net; 52 int (*func)(struct rt6_info *, void *arg); 53 int sernum; 54 void *arg; 55 }; 56 57 static DEFINE_RWLOCK(fib6_walker_lock); 58 59 #ifdef CONFIG_IPV6_SUBTREES 60 #define FWS_INIT FWS_S 61 #else 62 #define FWS_INIT FWS_L 63 #endif 64 65 static void fib6_prune_clones(struct net *net, struct fib6_node *fn); 66 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 67 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 68 static int fib6_walk(struct fib6_walker *w); 69 static int fib6_walk_continue(struct fib6_walker *w); 70 71 /* 72 * A routing update causes an increase of the serial number on the 73 * affected subtree. This allows for cached routes to be asynchronously 74 * tested when modifications are made to the destination cache as a 75 * result of redirects, path MTU changes, etc. 76 */ 77 78 static void fib6_gc_timer_cb(unsigned long arg); 79 80 static LIST_HEAD(fib6_walkers); 81 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh) 82 83 static void fib6_walker_link(struct fib6_walker *w) 84 { 85 write_lock_bh(&fib6_walker_lock); 86 list_add(&w->lh, &fib6_walkers); 87 write_unlock_bh(&fib6_walker_lock); 88 } 89 90 static void fib6_walker_unlink(struct fib6_walker *w) 91 { 92 write_lock_bh(&fib6_walker_lock); 93 list_del(&w->lh); 94 write_unlock_bh(&fib6_walker_lock); 95 } 96 97 static int fib6_new_sernum(struct net *net) 98 { 99 int new, old; 100 101 do { 102 old = atomic_read(&net->ipv6.fib6_sernum); 103 new = old < INT_MAX ? old + 1 : 1; 104 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 105 old, new) != old); 106 return new; 107 } 108 109 enum { 110 FIB6_NO_SERNUM_CHANGE = 0, 111 }; 112 113 /* 114 * Auxiliary address test functions for the radix tree. 115 * 116 * These assume a 32bit processor (although it will work on 117 * 64bit processors) 118 */ 119 120 /* 121 * test bit 122 */ 123 #if defined(__LITTLE_ENDIAN) 124 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 125 #else 126 # define BITOP_BE32_SWIZZLE 0 127 #endif 128 129 static __be32 addr_bit_set(const void *token, int fn_bit) 130 { 131 const __be32 *addr = token; 132 /* 133 * Here, 134 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 135 * is optimized version of 136 * htonl(1 << ((~fn_bit)&0x1F)) 137 * See include/asm-generic/bitops/le.h. 138 */ 139 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 140 addr[fn_bit >> 5]; 141 } 142 143 static struct fib6_node *node_alloc(void) 144 { 145 struct fib6_node *fn; 146 147 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 148 149 return fn; 150 } 151 152 static void node_free(struct fib6_node *fn) 153 { 154 kmem_cache_free(fib6_node_kmem, fn); 155 } 156 157 static void rt6_release(struct rt6_info *rt) 158 { 159 if (atomic_dec_and_test(&rt->rt6i_ref)) 160 dst_free(&rt->dst); 161 } 162 163 static void fib6_link_table(struct net *net, struct fib6_table *tb) 164 { 165 unsigned int h; 166 167 /* 168 * Initialize table lock at a single place to give lockdep a key, 169 * tables aren't visible prior to being linked to the list. 170 */ 171 rwlock_init(&tb->tb6_lock); 172 173 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 174 175 /* 176 * No protection necessary, this is the only list mutatation 177 * operation, tables never disappear once they exist. 178 */ 179 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 180 } 181 182 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 183 184 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 185 { 186 struct fib6_table *table; 187 188 table = kzalloc(sizeof(*table), GFP_ATOMIC); 189 if (table) { 190 table->tb6_id = id; 191 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 192 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 193 inet_peer_base_init(&table->tb6_peers); 194 } 195 196 return table; 197 } 198 199 struct fib6_table *fib6_new_table(struct net *net, u32 id) 200 { 201 struct fib6_table *tb; 202 203 if (id == 0) 204 id = RT6_TABLE_MAIN; 205 tb = fib6_get_table(net, id); 206 if (tb) 207 return tb; 208 209 tb = fib6_alloc_table(net, id); 210 if (tb) 211 fib6_link_table(net, tb); 212 213 return tb; 214 } 215 216 struct fib6_table *fib6_get_table(struct net *net, u32 id) 217 { 218 struct fib6_table *tb; 219 struct hlist_head *head; 220 unsigned int h; 221 222 if (id == 0) 223 id = RT6_TABLE_MAIN; 224 h = id & (FIB6_TABLE_HASHSZ - 1); 225 rcu_read_lock(); 226 head = &net->ipv6.fib_table_hash[h]; 227 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 228 if (tb->tb6_id == id) { 229 rcu_read_unlock(); 230 return tb; 231 } 232 } 233 rcu_read_unlock(); 234 235 return NULL; 236 } 237 238 static void __net_init fib6_tables_init(struct net *net) 239 { 240 fib6_link_table(net, net->ipv6.fib6_main_tbl); 241 fib6_link_table(net, net->ipv6.fib6_local_tbl); 242 } 243 #else 244 245 struct fib6_table *fib6_new_table(struct net *net, u32 id) 246 { 247 return fib6_get_table(net, id); 248 } 249 250 struct fib6_table *fib6_get_table(struct net *net, u32 id) 251 { 252 return net->ipv6.fib6_main_tbl; 253 } 254 255 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 256 int flags, pol_lookup_t lookup) 257 { 258 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 259 } 260 261 static void __net_init fib6_tables_init(struct net *net) 262 { 263 fib6_link_table(net, net->ipv6.fib6_main_tbl); 264 } 265 266 #endif 267 268 static int fib6_dump_node(struct fib6_walker *w) 269 { 270 int res; 271 struct rt6_info *rt; 272 273 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 274 res = rt6_dump_route(rt, w->args); 275 if (res < 0) { 276 /* Frame is full, suspend walking */ 277 w->leaf = rt; 278 return 1; 279 } 280 WARN_ON(res == 0); 281 } 282 w->leaf = NULL; 283 return 0; 284 } 285 286 static void fib6_dump_end(struct netlink_callback *cb) 287 { 288 struct fib6_walker *w = (void *)cb->args[2]; 289 290 if (w) { 291 if (cb->args[4]) { 292 cb->args[4] = 0; 293 fib6_walker_unlink(w); 294 } 295 cb->args[2] = 0; 296 kfree(w); 297 } 298 cb->done = (void *)cb->args[3]; 299 cb->args[1] = 3; 300 } 301 302 static int fib6_dump_done(struct netlink_callback *cb) 303 { 304 fib6_dump_end(cb); 305 return cb->done ? cb->done(cb) : 0; 306 } 307 308 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 309 struct netlink_callback *cb) 310 { 311 struct fib6_walker *w; 312 int res; 313 314 w = (void *)cb->args[2]; 315 w->root = &table->tb6_root; 316 317 if (cb->args[4] == 0) { 318 w->count = 0; 319 w->skip = 0; 320 321 read_lock_bh(&table->tb6_lock); 322 res = fib6_walk(w); 323 read_unlock_bh(&table->tb6_lock); 324 if (res > 0) { 325 cb->args[4] = 1; 326 cb->args[5] = w->root->fn_sernum; 327 } 328 } else { 329 if (cb->args[5] != w->root->fn_sernum) { 330 /* Begin at the root if the tree changed */ 331 cb->args[5] = w->root->fn_sernum; 332 w->state = FWS_INIT; 333 w->node = w->root; 334 w->skip = w->count; 335 } else 336 w->skip = 0; 337 338 read_lock_bh(&table->tb6_lock); 339 res = fib6_walk_continue(w); 340 read_unlock_bh(&table->tb6_lock); 341 if (res <= 0) { 342 fib6_walker_unlink(w); 343 cb->args[4] = 0; 344 } 345 } 346 347 return res; 348 } 349 350 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 351 { 352 struct net *net = sock_net(skb->sk); 353 unsigned int h, s_h; 354 unsigned int e = 0, s_e; 355 struct rt6_rtnl_dump_arg arg; 356 struct fib6_walker *w; 357 struct fib6_table *tb; 358 struct hlist_head *head; 359 int res = 0; 360 361 s_h = cb->args[0]; 362 s_e = cb->args[1]; 363 364 w = (void *)cb->args[2]; 365 if (!w) { 366 /* New dump: 367 * 368 * 1. hook callback destructor. 369 */ 370 cb->args[3] = (long)cb->done; 371 cb->done = fib6_dump_done; 372 373 /* 374 * 2. allocate and initialize walker. 375 */ 376 w = kzalloc(sizeof(*w), GFP_ATOMIC); 377 if (!w) 378 return -ENOMEM; 379 w->func = fib6_dump_node; 380 cb->args[2] = (long)w; 381 } 382 383 arg.skb = skb; 384 arg.cb = cb; 385 arg.net = net; 386 w->args = &arg; 387 388 rcu_read_lock(); 389 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 390 e = 0; 391 head = &net->ipv6.fib_table_hash[h]; 392 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 393 if (e < s_e) 394 goto next; 395 res = fib6_dump_table(tb, skb, cb); 396 if (res != 0) 397 goto out; 398 next: 399 e++; 400 } 401 } 402 out: 403 rcu_read_unlock(); 404 cb->args[1] = e; 405 cb->args[0] = h; 406 407 res = res < 0 ? res : skb->len; 408 if (res <= 0) 409 fib6_dump_end(cb); 410 return res; 411 } 412 413 /* 414 * Routing Table 415 * 416 * return the appropriate node for a routing tree "add" operation 417 * by either creating and inserting or by returning an existing 418 * node. 419 */ 420 421 static struct fib6_node *fib6_add_1(struct fib6_node *root, 422 struct in6_addr *addr, int plen, 423 int offset, int allow_create, 424 int replace_required, int sernum) 425 { 426 struct fib6_node *fn, *in, *ln; 427 struct fib6_node *pn = NULL; 428 struct rt6key *key; 429 int bit; 430 __be32 dir = 0; 431 432 RT6_TRACE("fib6_add_1\n"); 433 434 /* insert node in tree */ 435 436 fn = root; 437 438 do { 439 key = (struct rt6key *)((u8 *)fn->leaf + offset); 440 441 /* 442 * Prefix match 443 */ 444 if (plen < fn->fn_bit || 445 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 446 if (!allow_create) { 447 if (replace_required) { 448 pr_warn("Can't replace route, no match found\n"); 449 return ERR_PTR(-ENOENT); 450 } 451 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 452 } 453 goto insert_above; 454 } 455 456 /* 457 * Exact match ? 458 */ 459 460 if (plen == fn->fn_bit) { 461 /* clean up an intermediate node */ 462 if (!(fn->fn_flags & RTN_RTINFO)) { 463 rt6_release(fn->leaf); 464 fn->leaf = NULL; 465 } 466 467 fn->fn_sernum = sernum; 468 469 return fn; 470 } 471 472 /* 473 * We have more bits to go 474 */ 475 476 /* Try to walk down on tree. */ 477 fn->fn_sernum = sernum; 478 dir = addr_bit_set(addr, fn->fn_bit); 479 pn = fn; 480 fn = dir ? fn->right : fn->left; 481 } while (fn); 482 483 if (!allow_create) { 484 /* We should not create new node because 485 * NLM_F_REPLACE was specified without NLM_F_CREATE 486 * I assume it is safe to require NLM_F_CREATE when 487 * REPLACE flag is used! Later we may want to remove the 488 * check for replace_required, because according 489 * to netlink specification, NLM_F_CREATE 490 * MUST be specified if new route is created. 491 * That would keep IPv6 consistent with IPv4 492 */ 493 if (replace_required) { 494 pr_warn("Can't replace route, no match found\n"); 495 return ERR_PTR(-ENOENT); 496 } 497 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 498 } 499 /* 500 * We walked to the bottom of tree. 501 * Create new leaf node without children. 502 */ 503 504 ln = node_alloc(); 505 506 if (!ln) 507 return ERR_PTR(-ENOMEM); 508 ln->fn_bit = plen; 509 510 ln->parent = pn; 511 ln->fn_sernum = sernum; 512 513 if (dir) 514 pn->right = ln; 515 else 516 pn->left = ln; 517 518 return ln; 519 520 521 insert_above: 522 /* 523 * split since we don't have a common prefix anymore or 524 * we have a less significant route. 525 * we've to insert an intermediate node on the list 526 * this new node will point to the one we need to create 527 * and the current 528 */ 529 530 pn = fn->parent; 531 532 /* find 1st bit in difference between the 2 addrs. 533 534 See comment in __ipv6_addr_diff: bit may be an invalid value, 535 but if it is >= plen, the value is ignored in any case. 536 */ 537 538 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 539 540 /* 541 * (intermediate)[in] 542 * / \ 543 * (new leaf node)[ln] (old node)[fn] 544 */ 545 if (plen > bit) { 546 in = node_alloc(); 547 ln = node_alloc(); 548 549 if (!in || !ln) { 550 if (in) 551 node_free(in); 552 if (ln) 553 node_free(ln); 554 return ERR_PTR(-ENOMEM); 555 } 556 557 /* 558 * new intermediate node. 559 * RTN_RTINFO will 560 * be off since that an address that chooses one of 561 * the branches would not match less specific routes 562 * in the other branch 563 */ 564 565 in->fn_bit = bit; 566 567 in->parent = pn; 568 in->leaf = fn->leaf; 569 atomic_inc(&in->leaf->rt6i_ref); 570 571 in->fn_sernum = sernum; 572 573 /* update parent pointer */ 574 if (dir) 575 pn->right = in; 576 else 577 pn->left = in; 578 579 ln->fn_bit = plen; 580 581 ln->parent = in; 582 fn->parent = in; 583 584 ln->fn_sernum = sernum; 585 586 if (addr_bit_set(addr, bit)) { 587 in->right = ln; 588 in->left = fn; 589 } else { 590 in->left = ln; 591 in->right = fn; 592 } 593 } else { /* plen <= bit */ 594 595 /* 596 * (new leaf node)[ln] 597 * / \ 598 * (old node)[fn] NULL 599 */ 600 601 ln = node_alloc(); 602 603 if (!ln) 604 return ERR_PTR(-ENOMEM); 605 606 ln->fn_bit = plen; 607 608 ln->parent = pn; 609 610 ln->fn_sernum = sernum; 611 612 if (dir) 613 pn->right = ln; 614 else 615 pn->left = ln; 616 617 if (addr_bit_set(&key->addr, plen)) 618 ln->right = fn; 619 else 620 ln->left = fn; 621 622 fn->parent = ln; 623 } 624 return ln; 625 } 626 627 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 628 { 629 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 630 RTF_GATEWAY; 631 } 632 633 static int fib6_commit_metrics(struct dst_entry *dst, 634 struct nlattr *mx, int mx_len) 635 { 636 struct nlattr *nla; 637 int remaining; 638 u32 *mp; 639 640 if (dst->flags & DST_HOST) { 641 mp = dst_metrics_write_ptr(dst); 642 } else { 643 mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_ATOMIC); 644 if (!mp) 645 return -ENOMEM; 646 dst_init_metrics(dst, mp, 0); 647 } 648 649 nla_for_each_attr(nla, mx, mx_len, remaining) { 650 int type = nla_type(nla); 651 652 if (type) { 653 if (type > RTAX_MAX) 654 return -EINVAL; 655 656 mp[type - 1] = nla_get_u32(nla); 657 } 658 } 659 return 0; 660 } 661 662 /* 663 * Insert routing information in a node. 664 */ 665 666 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 667 struct nl_info *info, struct nlattr *mx, int mx_len) 668 { 669 struct rt6_info *iter = NULL; 670 struct rt6_info **ins; 671 int replace = (info->nlh && 672 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 673 int add = (!info->nlh || 674 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 675 int found = 0; 676 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 677 int err; 678 679 ins = &fn->leaf; 680 681 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 682 /* 683 * Search for duplicates 684 */ 685 686 if (iter->rt6i_metric == rt->rt6i_metric) { 687 /* 688 * Same priority level 689 */ 690 if (info->nlh && 691 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 692 return -EEXIST; 693 if (replace) { 694 found++; 695 break; 696 } 697 698 if (iter->dst.dev == rt->dst.dev && 699 iter->rt6i_idev == rt->rt6i_idev && 700 ipv6_addr_equal(&iter->rt6i_gateway, 701 &rt->rt6i_gateway)) { 702 if (rt->rt6i_nsiblings) 703 rt->rt6i_nsiblings = 0; 704 if (!(iter->rt6i_flags & RTF_EXPIRES)) 705 return -EEXIST; 706 if (!(rt->rt6i_flags & RTF_EXPIRES)) 707 rt6_clean_expires(iter); 708 else 709 rt6_set_expires(iter, rt->dst.expires); 710 return -EEXIST; 711 } 712 /* If we have the same destination and the same metric, 713 * but not the same gateway, then the route we try to 714 * add is sibling to this route, increment our counter 715 * of siblings, and later we will add our route to the 716 * list. 717 * Only static routes (which don't have flag 718 * RTF_EXPIRES) are used for ECMPv6. 719 * 720 * To avoid long list, we only had siblings if the 721 * route have a gateway. 722 */ 723 if (rt_can_ecmp && 724 rt6_qualify_for_ecmp(iter)) 725 rt->rt6i_nsiblings++; 726 } 727 728 if (iter->rt6i_metric > rt->rt6i_metric) 729 break; 730 731 ins = &iter->dst.rt6_next; 732 } 733 734 /* Reset round-robin state, if necessary */ 735 if (ins == &fn->leaf) 736 fn->rr_ptr = NULL; 737 738 /* Link this route to others same route. */ 739 if (rt->rt6i_nsiblings) { 740 unsigned int rt6i_nsiblings; 741 struct rt6_info *sibling, *temp_sibling; 742 743 /* Find the first route that have the same metric */ 744 sibling = fn->leaf; 745 while (sibling) { 746 if (sibling->rt6i_metric == rt->rt6i_metric && 747 rt6_qualify_for_ecmp(sibling)) { 748 list_add_tail(&rt->rt6i_siblings, 749 &sibling->rt6i_siblings); 750 break; 751 } 752 sibling = sibling->dst.rt6_next; 753 } 754 /* For each sibling in the list, increment the counter of 755 * siblings. BUG() if counters does not match, list of siblings 756 * is broken! 757 */ 758 rt6i_nsiblings = 0; 759 list_for_each_entry_safe(sibling, temp_sibling, 760 &rt->rt6i_siblings, rt6i_siblings) { 761 sibling->rt6i_nsiblings++; 762 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 763 rt6i_nsiblings++; 764 } 765 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 766 } 767 768 /* 769 * insert node 770 */ 771 if (!replace) { 772 if (!add) 773 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 774 775 add: 776 if (mx) { 777 err = fib6_commit_metrics(&rt->dst, mx, mx_len); 778 if (err) 779 return err; 780 } 781 rt->dst.rt6_next = iter; 782 *ins = rt; 783 rt->rt6i_node = fn; 784 atomic_inc(&rt->rt6i_ref); 785 inet6_rt_notify(RTM_NEWROUTE, rt, info); 786 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 787 788 if (!(fn->fn_flags & RTN_RTINFO)) { 789 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 790 fn->fn_flags |= RTN_RTINFO; 791 } 792 793 } else { 794 if (!found) { 795 if (add) 796 goto add; 797 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 798 return -ENOENT; 799 } 800 if (mx) { 801 err = fib6_commit_metrics(&rt->dst, mx, mx_len); 802 if (err) 803 return err; 804 } 805 *ins = rt; 806 rt->rt6i_node = fn; 807 rt->dst.rt6_next = iter->dst.rt6_next; 808 atomic_inc(&rt->rt6i_ref); 809 inet6_rt_notify(RTM_NEWROUTE, rt, info); 810 rt6_release(iter); 811 if (!(fn->fn_flags & RTN_RTINFO)) { 812 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 813 fn->fn_flags |= RTN_RTINFO; 814 } 815 } 816 817 return 0; 818 } 819 820 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 821 { 822 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 823 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 824 mod_timer(&net->ipv6.ip6_fib_timer, 825 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 826 } 827 828 void fib6_force_start_gc(struct net *net) 829 { 830 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 831 mod_timer(&net->ipv6.ip6_fib_timer, 832 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 833 } 834 835 /* 836 * Add routing information to the routing tree. 837 * <destination addr>/<source addr> 838 * with source addr info in sub-trees 839 */ 840 841 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info, 842 struct nlattr *mx, int mx_len) 843 { 844 struct fib6_node *fn, *pn = NULL; 845 int err = -ENOMEM; 846 int allow_create = 1; 847 int replace_required = 0; 848 int sernum = fib6_new_sernum(info->nl_net); 849 850 if (info->nlh) { 851 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 852 allow_create = 0; 853 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 854 replace_required = 1; 855 } 856 if (!allow_create && !replace_required) 857 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 858 859 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 860 offsetof(struct rt6_info, rt6i_dst), allow_create, 861 replace_required, sernum); 862 if (IS_ERR(fn)) { 863 err = PTR_ERR(fn); 864 fn = NULL; 865 goto out; 866 } 867 868 pn = fn; 869 870 #ifdef CONFIG_IPV6_SUBTREES 871 if (rt->rt6i_src.plen) { 872 struct fib6_node *sn; 873 874 if (!fn->subtree) { 875 struct fib6_node *sfn; 876 877 /* 878 * Create subtree. 879 * 880 * fn[main tree] 881 * | 882 * sfn[subtree root] 883 * \ 884 * sn[new leaf node] 885 */ 886 887 /* Create subtree root node */ 888 sfn = node_alloc(); 889 if (!sfn) 890 goto st_failure; 891 892 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 893 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 894 sfn->fn_flags = RTN_ROOT; 895 sfn->fn_sernum = sernum; 896 897 /* Now add the first leaf node to new subtree */ 898 899 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 900 rt->rt6i_src.plen, 901 offsetof(struct rt6_info, rt6i_src), 902 allow_create, replace_required, sernum); 903 904 if (IS_ERR(sn)) { 905 /* If it is failed, discard just allocated 906 root, and then (in st_failure) stale node 907 in main tree. 908 */ 909 node_free(sfn); 910 err = PTR_ERR(sn); 911 goto st_failure; 912 } 913 914 /* Now link new subtree to main tree */ 915 sfn->parent = fn; 916 fn->subtree = sfn; 917 } else { 918 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 919 rt->rt6i_src.plen, 920 offsetof(struct rt6_info, rt6i_src), 921 allow_create, replace_required, sernum); 922 923 if (IS_ERR(sn)) { 924 err = PTR_ERR(sn); 925 goto st_failure; 926 } 927 } 928 929 if (!fn->leaf) { 930 fn->leaf = rt; 931 atomic_inc(&rt->rt6i_ref); 932 } 933 fn = sn; 934 } 935 #endif 936 937 err = fib6_add_rt2node(fn, rt, info, mx, mx_len); 938 if (!err) { 939 fib6_start_gc(info->nl_net, rt); 940 if (!(rt->rt6i_flags & RTF_CACHE)) 941 fib6_prune_clones(info->nl_net, pn); 942 } 943 944 out: 945 if (err) { 946 #ifdef CONFIG_IPV6_SUBTREES 947 /* 948 * If fib6_add_1 has cleared the old leaf pointer in the 949 * super-tree leaf node we have to find a new one for it. 950 */ 951 if (pn != fn && pn->leaf == rt) { 952 pn->leaf = NULL; 953 atomic_dec(&rt->rt6i_ref); 954 } 955 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 956 pn->leaf = fib6_find_prefix(info->nl_net, pn); 957 #if RT6_DEBUG >= 2 958 if (!pn->leaf) { 959 WARN_ON(pn->leaf == NULL); 960 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 961 } 962 #endif 963 atomic_inc(&pn->leaf->rt6i_ref); 964 } 965 #endif 966 dst_free(&rt->dst); 967 } 968 return err; 969 970 #ifdef CONFIG_IPV6_SUBTREES 971 /* Subtree creation failed, probably main tree node 972 is orphan. If it is, shoot it. 973 */ 974 st_failure: 975 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 976 fib6_repair_tree(info->nl_net, fn); 977 dst_free(&rt->dst); 978 return err; 979 #endif 980 } 981 982 /* 983 * Routing tree lookup 984 * 985 */ 986 987 struct lookup_args { 988 int offset; /* key offset on rt6_info */ 989 const struct in6_addr *addr; /* search key */ 990 }; 991 992 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 993 struct lookup_args *args) 994 { 995 struct fib6_node *fn; 996 __be32 dir; 997 998 if (unlikely(args->offset == 0)) 999 return NULL; 1000 1001 /* 1002 * Descend on a tree 1003 */ 1004 1005 fn = root; 1006 1007 for (;;) { 1008 struct fib6_node *next; 1009 1010 dir = addr_bit_set(args->addr, fn->fn_bit); 1011 1012 next = dir ? fn->right : fn->left; 1013 1014 if (next) { 1015 fn = next; 1016 continue; 1017 } 1018 break; 1019 } 1020 1021 while (fn) { 1022 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1023 struct rt6key *key; 1024 1025 key = (struct rt6key *) ((u8 *) fn->leaf + 1026 args->offset); 1027 1028 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1029 #ifdef CONFIG_IPV6_SUBTREES 1030 if (fn->subtree) { 1031 struct fib6_node *sfn; 1032 sfn = fib6_lookup_1(fn->subtree, 1033 args + 1); 1034 if (!sfn) 1035 goto backtrack; 1036 fn = sfn; 1037 } 1038 #endif 1039 if (fn->fn_flags & RTN_RTINFO) 1040 return fn; 1041 } 1042 } 1043 #ifdef CONFIG_IPV6_SUBTREES 1044 backtrack: 1045 #endif 1046 if (fn->fn_flags & RTN_ROOT) 1047 break; 1048 1049 fn = fn->parent; 1050 } 1051 1052 return NULL; 1053 } 1054 1055 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1056 const struct in6_addr *saddr) 1057 { 1058 struct fib6_node *fn; 1059 struct lookup_args args[] = { 1060 { 1061 .offset = offsetof(struct rt6_info, rt6i_dst), 1062 .addr = daddr, 1063 }, 1064 #ifdef CONFIG_IPV6_SUBTREES 1065 { 1066 .offset = offsetof(struct rt6_info, rt6i_src), 1067 .addr = saddr, 1068 }, 1069 #endif 1070 { 1071 .offset = 0, /* sentinel */ 1072 } 1073 }; 1074 1075 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1076 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1077 fn = root; 1078 1079 return fn; 1080 } 1081 1082 /* 1083 * Get node with specified destination prefix (and source prefix, 1084 * if subtrees are used) 1085 */ 1086 1087 1088 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1089 const struct in6_addr *addr, 1090 int plen, int offset) 1091 { 1092 struct fib6_node *fn; 1093 1094 for (fn = root; fn ; ) { 1095 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1096 1097 /* 1098 * Prefix match 1099 */ 1100 if (plen < fn->fn_bit || 1101 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1102 return NULL; 1103 1104 if (plen == fn->fn_bit) 1105 return fn; 1106 1107 /* 1108 * We have more bits to go 1109 */ 1110 if (addr_bit_set(addr, fn->fn_bit)) 1111 fn = fn->right; 1112 else 1113 fn = fn->left; 1114 } 1115 return NULL; 1116 } 1117 1118 struct fib6_node *fib6_locate(struct fib6_node *root, 1119 const struct in6_addr *daddr, int dst_len, 1120 const struct in6_addr *saddr, int src_len) 1121 { 1122 struct fib6_node *fn; 1123 1124 fn = fib6_locate_1(root, daddr, dst_len, 1125 offsetof(struct rt6_info, rt6i_dst)); 1126 1127 #ifdef CONFIG_IPV6_SUBTREES 1128 if (src_len) { 1129 WARN_ON(saddr == NULL); 1130 if (fn && fn->subtree) 1131 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1132 offsetof(struct rt6_info, rt6i_src)); 1133 } 1134 #endif 1135 1136 if (fn && fn->fn_flags & RTN_RTINFO) 1137 return fn; 1138 1139 return NULL; 1140 } 1141 1142 1143 /* 1144 * Deletion 1145 * 1146 */ 1147 1148 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1149 { 1150 if (fn->fn_flags & RTN_ROOT) 1151 return net->ipv6.ip6_null_entry; 1152 1153 while (fn) { 1154 if (fn->left) 1155 return fn->left->leaf; 1156 if (fn->right) 1157 return fn->right->leaf; 1158 1159 fn = FIB6_SUBTREE(fn); 1160 } 1161 return NULL; 1162 } 1163 1164 /* 1165 * Called to trim the tree of intermediate nodes when possible. "fn" 1166 * is the node we want to try and remove. 1167 */ 1168 1169 static struct fib6_node *fib6_repair_tree(struct net *net, 1170 struct fib6_node *fn) 1171 { 1172 int children; 1173 int nstate; 1174 struct fib6_node *child, *pn; 1175 struct fib6_walker *w; 1176 int iter = 0; 1177 1178 for (;;) { 1179 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1180 iter++; 1181 1182 WARN_ON(fn->fn_flags & RTN_RTINFO); 1183 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1184 WARN_ON(fn->leaf != NULL); 1185 1186 children = 0; 1187 child = NULL; 1188 if (fn->right) 1189 child = fn->right, children |= 1; 1190 if (fn->left) 1191 child = fn->left, children |= 2; 1192 1193 if (children == 3 || FIB6_SUBTREE(fn) 1194 #ifdef CONFIG_IPV6_SUBTREES 1195 /* Subtree root (i.e. fn) may have one child */ 1196 || (children && fn->fn_flags & RTN_ROOT) 1197 #endif 1198 ) { 1199 fn->leaf = fib6_find_prefix(net, fn); 1200 #if RT6_DEBUG >= 2 1201 if (!fn->leaf) { 1202 WARN_ON(!fn->leaf); 1203 fn->leaf = net->ipv6.ip6_null_entry; 1204 } 1205 #endif 1206 atomic_inc(&fn->leaf->rt6i_ref); 1207 return fn->parent; 1208 } 1209 1210 pn = fn->parent; 1211 #ifdef CONFIG_IPV6_SUBTREES 1212 if (FIB6_SUBTREE(pn) == fn) { 1213 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1214 FIB6_SUBTREE(pn) = NULL; 1215 nstate = FWS_L; 1216 } else { 1217 WARN_ON(fn->fn_flags & RTN_ROOT); 1218 #endif 1219 if (pn->right == fn) 1220 pn->right = child; 1221 else if (pn->left == fn) 1222 pn->left = child; 1223 #if RT6_DEBUG >= 2 1224 else 1225 WARN_ON(1); 1226 #endif 1227 if (child) 1228 child->parent = pn; 1229 nstate = FWS_R; 1230 #ifdef CONFIG_IPV6_SUBTREES 1231 } 1232 #endif 1233 1234 read_lock(&fib6_walker_lock); 1235 FOR_WALKERS(w) { 1236 if (!child) { 1237 if (w->root == fn) { 1238 w->root = w->node = NULL; 1239 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1240 } else if (w->node == fn) { 1241 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1242 w->node = pn; 1243 w->state = nstate; 1244 } 1245 } else { 1246 if (w->root == fn) { 1247 w->root = child; 1248 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1249 } 1250 if (w->node == fn) { 1251 w->node = child; 1252 if (children&2) { 1253 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1254 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1255 } else { 1256 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1257 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1258 } 1259 } 1260 } 1261 } 1262 read_unlock(&fib6_walker_lock); 1263 1264 node_free(fn); 1265 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1266 return pn; 1267 1268 rt6_release(pn->leaf); 1269 pn->leaf = NULL; 1270 fn = pn; 1271 } 1272 } 1273 1274 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1275 struct nl_info *info) 1276 { 1277 struct fib6_walker *w; 1278 struct rt6_info *rt = *rtp; 1279 struct net *net = info->nl_net; 1280 1281 RT6_TRACE("fib6_del_route\n"); 1282 1283 /* Unlink it */ 1284 *rtp = rt->dst.rt6_next; 1285 rt->rt6i_node = NULL; 1286 net->ipv6.rt6_stats->fib_rt_entries--; 1287 net->ipv6.rt6_stats->fib_discarded_routes++; 1288 1289 /* Reset round-robin state, if necessary */ 1290 if (fn->rr_ptr == rt) 1291 fn->rr_ptr = NULL; 1292 1293 /* Remove this entry from other siblings */ 1294 if (rt->rt6i_nsiblings) { 1295 struct rt6_info *sibling, *next_sibling; 1296 1297 list_for_each_entry_safe(sibling, next_sibling, 1298 &rt->rt6i_siblings, rt6i_siblings) 1299 sibling->rt6i_nsiblings--; 1300 rt->rt6i_nsiblings = 0; 1301 list_del_init(&rt->rt6i_siblings); 1302 } 1303 1304 /* Adjust walkers */ 1305 read_lock(&fib6_walker_lock); 1306 FOR_WALKERS(w) { 1307 if (w->state == FWS_C && w->leaf == rt) { 1308 RT6_TRACE("walker %p adjusted by delroute\n", w); 1309 w->leaf = rt->dst.rt6_next; 1310 if (!w->leaf) 1311 w->state = FWS_U; 1312 } 1313 } 1314 read_unlock(&fib6_walker_lock); 1315 1316 rt->dst.rt6_next = NULL; 1317 1318 /* If it was last route, expunge its radix tree node */ 1319 if (!fn->leaf) { 1320 fn->fn_flags &= ~RTN_RTINFO; 1321 net->ipv6.rt6_stats->fib_route_nodes--; 1322 fn = fib6_repair_tree(net, fn); 1323 } 1324 1325 if (atomic_read(&rt->rt6i_ref) != 1) { 1326 /* This route is used as dummy address holder in some split 1327 * nodes. It is not leaked, but it still holds other resources, 1328 * which must be released in time. So, scan ascendant nodes 1329 * and replace dummy references to this route with references 1330 * to still alive ones. 1331 */ 1332 while (fn) { 1333 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 1334 fn->leaf = fib6_find_prefix(net, fn); 1335 atomic_inc(&fn->leaf->rt6i_ref); 1336 rt6_release(rt); 1337 } 1338 fn = fn->parent; 1339 } 1340 /* No more references are possible at this point. */ 1341 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 1342 } 1343 1344 inet6_rt_notify(RTM_DELROUTE, rt, info); 1345 rt6_release(rt); 1346 } 1347 1348 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1349 { 1350 struct net *net = info->nl_net; 1351 struct fib6_node *fn = rt->rt6i_node; 1352 struct rt6_info **rtp; 1353 1354 #if RT6_DEBUG >= 2 1355 if (rt->dst.obsolete > 0) { 1356 WARN_ON(fn != NULL); 1357 return -ENOENT; 1358 } 1359 #endif 1360 if (!fn || rt == net->ipv6.ip6_null_entry) 1361 return -ENOENT; 1362 1363 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1364 1365 if (!(rt->rt6i_flags & RTF_CACHE)) { 1366 struct fib6_node *pn = fn; 1367 #ifdef CONFIG_IPV6_SUBTREES 1368 /* clones of this route might be in another subtree */ 1369 if (rt->rt6i_src.plen) { 1370 while (!(pn->fn_flags & RTN_ROOT)) 1371 pn = pn->parent; 1372 pn = pn->parent; 1373 } 1374 #endif 1375 fib6_prune_clones(info->nl_net, pn); 1376 } 1377 1378 /* 1379 * Walk the leaf entries looking for ourself 1380 */ 1381 1382 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1383 if (*rtp == rt) { 1384 fib6_del_route(fn, rtp, info); 1385 return 0; 1386 } 1387 } 1388 return -ENOENT; 1389 } 1390 1391 /* 1392 * Tree traversal function. 1393 * 1394 * Certainly, it is not interrupt safe. 1395 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1396 * It means, that we can modify tree during walking 1397 * and use this function for garbage collection, clone pruning, 1398 * cleaning tree when a device goes down etc. etc. 1399 * 1400 * It guarantees that every node will be traversed, 1401 * and that it will be traversed only once. 1402 * 1403 * Callback function w->func may return: 1404 * 0 -> continue walking. 1405 * positive value -> walking is suspended (used by tree dumps, 1406 * and probably by gc, if it will be split to several slices) 1407 * negative value -> terminate walking. 1408 * 1409 * The function itself returns: 1410 * 0 -> walk is complete. 1411 * >0 -> walk is incomplete (i.e. suspended) 1412 * <0 -> walk is terminated by an error. 1413 */ 1414 1415 static int fib6_walk_continue(struct fib6_walker *w) 1416 { 1417 struct fib6_node *fn, *pn; 1418 1419 for (;;) { 1420 fn = w->node; 1421 if (!fn) 1422 return 0; 1423 1424 if (w->prune && fn != w->root && 1425 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1426 w->state = FWS_C; 1427 w->leaf = fn->leaf; 1428 } 1429 switch (w->state) { 1430 #ifdef CONFIG_IPV6_SUBTREES 1431 case FWS_S: 1432 if (FIB6_SUBTREE(fn)) { 1433 w->node = FIB6_SUBTREE(fn); 1434 continue; 1435 } 1436 w->state = FWS_L; 1437 #endif 1438 case FWS_L: 1439 if (fn->left) { 1440 w->node = fn->left; 1441 w->state = FWS_INIT; 1442 continue; 1443 } 1444 w->state = FWS_R; 1445 case FWS_R: 1446 if (fn->right) { 1447 w->node = fn->right; 1448 w->state = FWS_INIT; 1449 continue; 1450 } 1451 w->state = FWS_C; 1452 w->leaf = fn->leaf; 1453 case FWS_C: 1454 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1455 int err; 1456 1457 if (w->skip) { 1458 w->skip--; 1459 goto skip; 1460 } 1461 1462 err = w->func(w); 1463 if (err) 1464 return err; 1465 1466 w->count++; 1467 continue; 1468 } 1469 skip: 1470 w->state = FWS_U; 1471 case FWS_U: 1472 if (fn == w->root) 1473 return 0; 1474 pn = fn->parent; 1475 w->node = pn; 1476 #ifdef CONFIG_IPV6_SUBTREES 1477 if (FIB6_SUBTREE(pn) == fn) { 1478 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1479 w->state = FWS_L; 1480 continue; 1481 } 1482 #endif 1483 if (pn->left == fn) { 1484 w->state = FWS_R; 1485 continue; 1486 } 1487 if (pn->right == fn) { 1488 w->state = FWS_C; 1489 w->leaf = w->node->leaf; 1490 continue; 1491 } 1492 #if RT6_DEBUG >= 2 1493 WARN_ON(1); 1494 #endif 1495 } 1496 } 1497 } 1498 1499 static int fib6_walk(struct fib6_walker *w) 1500 { 1501 int res; 1502 1503 w->state = FWS_INIT; 1504 w->node = w->root; 1505 1506 fib6_walker_link(w); 1507 res = fib6_walk_continue(w); 1508 if (res <= 0) 1509 fib6_walker_unlink(w); 1510 return res; 1511 } 1512 1513 static int fib6_clean_node(struct fib6_walker *w) 1514 { 1515 int res; 1516 struct rt6_info *rt; 1517 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1518 struct nl_info info = { 1519 .nl_net = c->net, 1520 }; 1521 1522 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1523 w->node->fn_sernum != c->sernum) 1524 w->node->fn_sernum = c->sernum; 1525 1526 if (!c->func) { 1527 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1528 w->leaf = NULL; 1529 return 0; 1530 } 1531 1532 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1533 res = c->func(rt, c->arg); 1534 if (res < 0) { 1535 w->leaf = rt; 1536 res = fib6_del(rt, &info); 1537 if (res) { 1538 #if RT6_DEBUG >= 2 1539 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1540 __func__, rt, rt->rt6i_node, res); 1541 #endif 1542 continue; 1543 } 1544 return 0; 1545 } 1546 WARN_ON(res != 0); 1547 } 1548 w->leaf = rt; 1549 return 0; 1550 } 1551 1552 /* 1553 * Convenient frontend to tree walker. 1554 * 1555 * func is called on each route. 1556 * It may return -1 -> delete this route. 1557 * 0 -> continue walking 1558 * 1559 * prune==1 -> only immediate children of node (certainly, 1560 * ignoring pure split nodes) will be scanned. 1561 */ 1562 1563 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1564 int (*func)(struct rt6_info *, void *arg), 1565 bool prune, int sernum, void *arg) 1566 { 1567 struct fib6_cleaner c; 1568 1569 c.w.root = root; 1570 c.w.func = fib6_clean_node; 1571 c.w.prune = prune; 1572 c.w.count = 0; 1573 c.w.skip = 0; 1574 c.func = func; 1575 c.sernum = sernum; 1576 c.arg = arg; 1577 c.net = net; 1578 1579 fib6_walk(&c.w); 1580 } 1581 1582 static void __fib6_clean_all(struct net *net, 1583 int (*func)(struct rt6_info *, void *), 1584 int sernum, void *arg) 1585 { 1586 struct fib6_table *table; 1587 struct hlist_head *head; 1588 unsigned int h; 1589 1590 rcu_read_lock(); 1591 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1592 head = &net->ipv6.fib_table_hash[h]; 1593 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1594 write_lock_bh(&table->tb6_lock); 1595 fib6_clean_tree(net, &table->tb6_root, 1596 func, false, sernum, arg); 1597 write_unlock_bh(&table->tb6_lock); 1598 } 1599 } 1600 rcu_read_unlock(); 1601 } 1602 1603 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1604 void *arg) 1605 { 1606 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1607 } 1608 1609 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1610 { 1611 if (rt->rt6i_flags & RTF_CACHE) { 1612 RT6_TRACE("pruning clone %p\n", rt); 1613 return -1; 1614 } 1615 1616 return 0; 1617 } 1618 1619 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1620 { 1621 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1622 FIB6_NO_SERNUM_CHANGE, NULL); 1623 } 1624 1625 static void fib6_flush_trees(struct net *net) 1626 { 1627 int new_sernum = fib6_new_sernum(net); 1628 1629 __fib6_clean_all(net, NULL, new_sernum, NULL); 1630 } 1631 1632 /* 1633 * Garbage collection 1634 */ 1635 1636 static struct fib6_gc_args 1637 { 1638 int timeout; 1639 int more; 1640 } gc_args; 1641 1642 static int fib6_age(struct rt6_info *rt, void *arg) 1643 { 1644 unsigned long now = jiffies; 1645 1646 /* 1647 * check addrconf expiration here. 1648 * Routes are expired even if they are in use. 1649 * 1650 * Also age clones. Note, that clones are aged out 1651 * only if they are not in use now. 1652 */ 1653 1654 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1655 if (time_after(now, rt->dst.expires)) { 1656 RT6_TRACE("expiring %p\n", rt); 1657 return -1; 1658 } 1659 gc_args.more++; 1660 } else if (rt->rt6i_flags & RTF_CACHE) { 1661 if (atomic_read(&rt->dst.__refcnt) == 0 && 1662 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1663 RT6_TRACE("aging clone %p\n", rt); 1664 return -1; 1665 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1666 struct neighbour *neigh; 1667 __u8 neigh_flags = 0; 1668 1669 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1670 if (neigh) { 1671 neigh_flags = neigh->flags; 1672 neigh_release(neigh); 1673 } 1674 if (!(neigh_flags & NTF_ROUTER)) { 1675 RT6_TRACE("purging route %p via non-router but gateway\n", 1676 rt); 1677 return -1; 1678 } 1679 } 1680 gc_args.more++; 1681 } 1682 1683 return 0; 1684 } 1685 1686 static DEFINE_SPINLOCK(fib6_gc_lock); 1687 1688 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1689 { 1690 unsigned long now; 1691 1692 if (force) { 1693 spin_lock_bh(&fib6_gc_lock); 1694 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1695 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1696 return; 1697 } 1698 gc_args.timeout = expires ? (int)expires : 1699 net->ipv6.sysctl.ip6_rt_gc_interval; 1700 1701 gc_args.more = icmp6_dst_gc(); 1702 1703 fib6_clean_all(net, fib6_age, NULL); 1704 now = jiffies; 1705 net->ipv6.ip6_rt_last_gc = now; 1706 1707 if (gc_args.more) 1708 mod_timer(&net->ipv6.ip6_fib_timer, 1709 round_jiffies(now 1710 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1711 else 1712 del_timer(&net->ipv6.ip6_fib_timer); 1713 spin_unlock_bh(&fib6_gc_lock); 1714 } 1715 1716 static void fib6_gc_timer_cb(unsigned long arg) 1717 { 1718 fib6_run_gc(0, (struct net *)arg, true); 1719 } 1720 1721 static int __net_init fib6_net_init(struct net *net) 1722 { 1723 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1724 1725 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1726 1727 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1728 if (!net->ipv6.rt6_stats) 1729 goto out_timer; 1730 1731 /* Avoid false sharing : Use at least a full cache line */ 1732 size = max_t(size_t, size, L1_CACHE_BYTES); 1733 1734 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1735 if (!net->ipv6.fib_table_hash) 1736 goto out_rt6_stats; 1737 1738 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1739 GFP_KERNEL); 1740 if (!net->ipv6.fib6_main_tbl) 1741 goto out_fib_table_hash; 1742 1743 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1744 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1745 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1746 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1747 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1748 1749 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1750 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1751 GFP_KERNEL); 1752 if (!net->ipv6.fib6_local_tbl) 1753 goto out_fib6_main_tbl; 1754 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1755 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1756 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1757 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1758 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1759 #endif 1760 fib6_tables_init(net); 1761 1762 return 0; 1763 1764 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1765 out_fib6_main_tbl: 1766 kfree(net->ipv6.fib6_main_tbl); 1767 #endif 1768 out_fib_table_hash: 1769 kfree(net->ipv6.fib_table_hash); 1770 out_rt6_stats: 1771 kfree(net->ipv6.rt6_stats); 1772 out_timer: 1773 return -ENOMEM; 1774 } 1775 1776 static void fib6_net_exit(struct net *net) 1777 { 1778 rt6_ifdown(net, NULL); 1779 del_timer_sync(&net->ipv6.ip6_fib_timer); 1780 1781 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1782 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1783 kfree(net->ipv6.fib6_local_tbl); 1784 #endif 1785 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1786 kfree(net->ipv6.fib6_main_tbl); 1787 kfree(net->ipv6.fib_table_hash); 1788 kfree(net->ipv6.rt6_stats); 1789 } 1790 1791 static struct pernet_operations fib6_net_ops = { 1792 .init = fib6_net_init, 1793 .exit = fib6_net_exit, 1794 }; 1795 1796 int __init fib6_init(void) 1797 { 1798 int ret = -ENOMEM; 1799 1800 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1801 sizeof(struct fib6_node), 1802 0, SLAB_HWCACHE_ALIGN, 1803 NULL); 1804 if (!fib6_node_kmem) 1805 goto out; 1806 1807 ret = register_pernet_subsys(&fib6_net_ops); 1808 if (ret) 1809 goto out_kmem_cache_create; 1810 1811 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1812 NULL); 1813 if (ret) 1814 goto out_unregister_subsys; 1815 1816 __fib6_flush_trees = fib6_flush_trees; 1817 out: 1818 return ret; 1819 1820 out_unregister_subsys: 1821 unregister_pernet_subsys(&fib6_net_ops); 1822 out_kmem_cache_create: 1823 kmem_cache_destroy(fib6_node_kmem); 1824 goto out; 1825 } 1826 1827 void fib6_gc_cleanup(void) 1828 { 1829 unregister_pernet_subsys(&fib6_net_ops); 1830 kmem_cache_destroy(fib6_node_kmem); 1831 } 1832 1833 #ifdef CONFIG_PROC_FS 1834 1835 struct ipv6_route_iter { 1836 struct seq_net_private p; 1837 struct fib6_walker w; 1838 loff_t skip; 1839 struct fib6_table *tbl; 1840 int sernum; 1841 }; 1842 1843 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1844 { 1845 struct rt6_info *rt = v; 1846 struct ipv6_route_iter *iter = seq->private; 1847 1848 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1849 1850 #ifdef CONFIG_IPV6_SUBTREES 1851 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1852 #else 1853 seq_puts(seq, "00000000000000000000000000000000 00 "); 1854 #endif 1855 if (rt->rt6i_flags & RTF_GATEWAY) 1856 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1857 else 1858 seq_puts(seq, "00000000000000000000000000000000"); 1859 1860 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1861 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1862 rt->dst.__use, rt->rt6i_flags, 1863 rt->dst.dev ? rt->dst.dev->name : ""); 1864 iter->w.leaf = NULL; 1865 return 0; 1866 } 1867 1868 static int ipv6_route_yield(struct fib6_walker *w) 1869 { 1870 struct ipv6_route_iter *iter = w->args; 1871 1872 if (!iter->skip) 1873 return 1; 1874 1875 do { 1876 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1877 iter->skip--; 1878 if (!iter->skip && iter->w.leaf) 1879 return 1; 1880 } while (iter->w.leaf); 1881 1882 return 0; 1883 } 1884 1885 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1886 { 1887 memset(&iter->w, 0, sizeof(iter->w)); 1888 iter->w.func = ipv6_route_yield; 1889 iter->w.root = &iter->tbl->tb6_root; 1890 iter->w.state = FWS_INIT; 1891 iter->w.node = iter->w.root; 1892 iter->w.args = iter; 1893 iter->sernum = iter->w.root->fn_sernum; 1894 INIT_LIST_HEAD(&iter->w.lh); 1895 fib6_walker_link(&iter->w); 1896 } 1897 1898 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1899 struct net *net) 1900 { 1901 unsigned int h; 1902 struct hlist_node *node; 1903 1904 if (tbl) { 1905 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1906 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1907 } else { 1908 h = 0; 1909 node = NULL; 1910 } 1911 1912 while (!node && h < FIB6_TABLE_HASHSZ) { 1913 node = rcu_dereference_bh( 1914 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 1915 } 1916 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 1917 } 1918 1919 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 1920 { 1921 if (iter->sernum != iter->w.root->fn_sernum) { 1922 iter->sernum = iter->w.root->fn_sernum; 1923 iter->w.state = FWS_INIT; 1924 iter->w.node = iter->w.root; 1925 WARN_ON(iter->w.skip); 1926 iter->w.skip = iter->w.count; 1927 } 1928 } 1929 1930 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1931 { 1932 int r; 1933 struct rt6_info *n; 1934 struct net *net = seq_file_net(seq); 1935 struct ipv6_route_iter *iter = seq->private; 1936 1937 if (!v) 1938 goto iter_table; 1939 1940 n = ((struct rt6_info *)v)->dst.rt6_next; 1941 if (n) { 1942 ++*pos; 1943 return n; 1944 } 1945 1946 iter_table: 1947 ipv6_route_check_sernum(iter); 1948 read_lock(&iter->tbl->tb6_lock); 1949 r = fib6_walk_continue(&iter->w); 1950 read_unlock(&iter->tbl->tb6_lock); 1951 if (r > 0) { 1952 if (v) 1953 ++*pos; 1954 return iter->w.leaf; 1955 } else if (r < 0) { 1956 fib6_walker_unlink(&iter->w); 1957 return NULL; 1958 } 1959 fib6_walker_unlink(&iter->w); 1960 1961 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 1962 if (!iter->tbl) 1963 return NULL; 1964 1965 ipv6_route_seq_setup_walk(iter); 1966 goto iter_table; 1967 } 1968 1969 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 1970 __acquires(RCU_BH) 1971 { 1972 struct net *net = seq_file_net(seq); 1973 struct ipv6_route_iter *iter = seq->private; 1974 1975 rcu_read_lock_bh(); 1976 iter->tbl = ipv6_route_seq_next_table(NULL, net); 1977 iter->skip = *pos; 1978 1979 if (iter->tbl) { 1980 ipv6_route_seq_setup_walk(iter); 1981 return ipv6_route_seq_next(seq, NULL, pos); 1982 } else { 1983 return NULL; 1984 } 1985 } 1986 1987 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 1988 { 1989 struct fib6_walker *w = &iter->w; 1990 return w->node && !(w->state == FWS_U && w->node == w->root); 1991 } 1992 1993 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 1994 __releases(RCU_BH) 1995 { 1996 struct ipv6_route_iter *iter = seq->private; 1997 1998 if (ipv6_route_iter_active(iter)) 1999 fib6_walker_unlink(&iter->w); 2000 2001 rcu_read_unlock_bh(); 2002 } 2003 2004 static const struct seq_operations ipv6_route_seq_ops = { 2005 .start = ipv6_route_seq_start, 2006 .next = ipv6_route_seq_next, 2007 .stop = ipv6_route_seq_stop, 2008 .show = ipv6_route_seq_show 2009 }; 2010 2011 int ipv6_route_open(struct inode *inode, struct file *file) 2012 { 2013 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2014 sizeof(struct ipv6_route_iter)); 2015 } 2016 2017 #endif /* CONFIG_PROC_FS */ 2018