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 } 281 w->leaf = NULL; 282 return 0; 283 } 284 285 static void fib6_dump_end(struct netlink_callback *cb) 286 { 287 struct fib6_walker *w = (void *)cb->args[2]; 288 289 if (w) { 290 if (cb->args[4]) { 291 cb->args[4] = 0; 292 fib6_walker_unlink(w); 293 } 294 cb->args[2] = 0; 295 kfree(w); 296 } 297 cb->done = (void *)cb->args[3]; 298 cb->args[1] = 3; 299 } 300 301 static int fib6_dump_done(struct netlink_callback *cb) 302 { 303 fib6_dump_end(cb); 304 return cb->done ? cb->done(cb) : 0; 305 } 306 307 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 308 struct netlink_callback *cb) 309 { 310 struct fib6_walker *w; 311 int res; 312 313 w = (void *)cb->args[2]; 314 w->root = &table->tb6_root; 315 316 if (cb->args[4] == 0) { 317 w->count = 0; 318 w->skip = 0; 319 320 read_lock_bh(&table->tb6_lock); 321 res = fib6_walk(w); 322 read_unlock_bh(&table->tb6_lock); 323 if (res > 0) { 324 cb->args[4] = 1; 325 cb->args[5] = w->root->fn_sernum; 326 } 327 } else { 328 if (cb->args[5] != w->root->fn_sernum) { 329 /* Begin at the root if the tree changed */ 330 cb->args[5] = w->root->fn_sernum; 331 w->state = FWS_INIT; 332 w->node = w->root; 333 w->skip = w->count; 334 } else 335 w->skip = 0; 336 337 read_lock_bh(&table->tb6_lock); 338 res = fib6_walk_continue(w); 339 read_unlock_bh(&table->tb6_lock); 340 if (res <= 0) { 341 fib6_walker_unlink(w); 342 cb->args[4] = 0; 343 } 344 } 345 346 return res; 347 } 348 349 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 350 { 351 struct net *net = sock_net(skb->sk); 352 unsigned int h, s_h; 353 unsigned int e = 0, s_e; 354 struct rt6_rtnl_dump_arg arg; 355 struct fib6_walker *w; 356 struct fib6_table *tb; 357 struct hlist_head *head; 358 int res = 0; 359 360 s_h = cb->args[0]; 361 s_e = cb->args[1]; 362 363 w = (void *)cb->args[2]; 364 if (!w) { 365 /* New dump: 366 * 367 * 1. hook callback destructor. 368 */ 369 cb->args[3] = (long)cb->done; 370 cb->done = fib6_dump_done; 371 372 /* 373 * 2. allocate and initialize walker. 374 */ 375 w = kzalloc(sizeof(*w), GFP_ATOMIC); 376 if (!w) 377 return -ENOMEM; 378 w->func = fib6_dump_node; 379 cb->args[2] = (long)w; 380 } 381 382 arg.skb = skb; 383 arg.cb = cb; 384 arg.net = net; 385 w->args = &arg; 386 387 rcu_read_lock(); 388 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 389 e = 0; 390 head = &net->ipv6.fib_table_hash[h]; 391 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 392 if (e < s_e) 393 goto next; 394 res = fib6_dump_table(tb, skb, cb); 395 if (res != 0) 396 goto out; 397 next: 398 e++; 399 } 400 } 401 out: 402 rcu_read_unlock(); 403 cb->args[1] = e; 404 cb->args[0] = h; 405 406 res = res < 0 ? res : skb->len; 407 if (res <= 0) 408 fib6_dump_end(cb); 409 return res; 410 } 411 412 /* 413 * Routing Table 414 * 415 * return the appropriate node for a routing tree "add" operation 416 * by either creating and inserting or by returning an existing 417 * node. 418 */ 419 420 static struct fib6_node *fib6_add_1(struct fib6_node *root, 421 struct in6_addr *addr, int plen, 422 int offset, int allow_create, 423 int replace_required, int sernum) 424 { 425 struct fib6_node *fn, *in, *ln; 426 struct fib6_node *pn = NULL; 427 struct rt6key *key; 428 int bit; 429 __be32 dir = 0; 430 431 RT6_TRACE("fib6_add_1\n"); 432 433 /* insert node in tree */ 434 435 fn = root; 436 437 do { 438 key = (struct rt6key *)((u8 *)fn->leaf + offset); 439 440 /* 441 * Prefix match 442 */ 443 if (plen < fn->fn_bit || 444 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 445 if (!allow_create) { 446 if (replace_required) { 447 pr_warn("Can't replace route, no match found\n"); 448 return ERR_PTR(-ENOENT); 449 } 450 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 451 } 452 goto insert_above; 453 } 454 455 /* 456 * Exact match ? 457 */ 458 459 if (plen == fn->fn_bit) { 460 /* clean up an intermediate node */ 461 if (!(fn->fn_flags & RTN_RTINFO)) { 462 rt6_release(fn->leaf); 463 fn->leaf = NULL; 464 } 465 466 fn->fn_sernum = sernum; 467 468 return fn; 469 } 470 471 /* 472 * We have more bits to go 473 */ 474 475 /* Try to walk down on tree. */ 476 fn->fn_sernum = sernum; 477 dir = addr_bit_set(addr, fn->fn_bit); 478 pn = fn; 479 fn = dir ? fn->right : fn->left; 480 } while (fn); 481 482 if (!allow_create) { 483 /* We should not create new node because 484 * NLM_F_REPLACE was specified without NLM_F_CREATE 485 * I assume it is safe to require NLM_F_CREATE when 486 * REPLACE flag is used! Later we may want to remove the 487 * check for replace_required, because according 488 * to netlink specification, NLM_F_CREATE 489 * MUST be specified if new route is created. 490 * That would keep IPv6 consistent with IPv4 491 */ 492 if (replace_required) { 493 pr_warn("Can't replace route, no match found\n"); 494 return ERR_PTR(-ENOENT); 495 } 496 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 497 } 498 /* 499 * We walked to the bottom of tree. 500 * Create new leaf node without children. 501 */ 502 503 ln = node_alloc(); 504 505 if (!ln) 506 return ERR_PTR(-ENOMEM); 507 ln->fn_bit = plen; 508 509 ln->parent = pn; 510 ln->fn_sernum = sernum; 511 512 if (dir) 513 pn->right = ln; 514 else 515 pn->left = ln; 516 517 return ln; 518 519 520 insert_above: 521 /* 522 * split since we don't have a common prefix anymore or 523 * we have a less significant route. 524 * we've to insert an intermediate node on the list 525 * this new node will point to the one we need to create 526 * and the current 527 */ 528 529 pn = fn->parent; 530 531 /* find 1st bit in difference between the 2 addrs. 532 533 See comment in __ipv6_addr_diff: bit may be an invalid value, 534 but if it is >= plen, the value is ignored in any case. 535 */ 536 537 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 538 539 /* 540 * (intermediate)[in] 541 * / \ 542 * (new leaf node)[ln] (old node)[fn] 543 */ 544 if (plen > bit) { 545 in = node_alloc(); 546 ln = node_alloc(); 547 548 if (!in || !ln) { 549 if (in) 550 node_free(in); 551 if (ln) 552 node_free(ln); 553 return ERR_PTR(-ENOMEM); 554 } 555 556 /* 557 * new intermediate node. 558 * RTN_RTINFO will 559 * be off since that an address that chooses one of 560 * the branches would not match less specific routes 561 * in the other branch 562 */ 563 564 in->fn_bit = bit; 565 566 in->parent = pn; 567 in->leaf = fn->leaf; 568 atomic_inc(&in->leaf->rt6i_ref); 569 570 in->fn_sernum = sernum; 571 572 /* update parent pointer */ 573 if (dir) 574 pn->right = in; 575 else 576 pn->left = in; 577 578 ln->fn_bit = plen; 579 580 ln->parent = in; 581 fn->parent = in; 582 583 ln->fn_sernum = sernum; 584 585 if (addr_bit_set(addr, bit)) { 586 in->right = ln; 587 in->left = fn; 588 } else { 589 in->left = ln; 590 in->right = fn; 591 } 592 } else { /* plen <= bit */ 593 594 /* 595 * (new leaf node)[ln] 596 * / \ 597 * (old node)[fn] NULL 598 */ 599 600 ln = node_alloc(); 601 602 if (!ln) 603 return ERR_PTR(-ENOMEM); 604 605 ln->fn_bit = plen; 606 607 ln->parent = pn; 608 609 ln->fn_sernum = sernum; 610 611 if (dir) 612 pn->right = ln; 613 else 614 pn->left = ln; 615 616 if (addr_bit_set(&key->addr, plen)) 617 ln->right = fn; 618 else 619 ln->left = fn; 620 621 fn->parent = ln; 622 } 623 return ln; 624 } 625 626 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 627 { 628 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 629 RTF_GATEWAY; 630 } 631 632 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 633 { 634 int i; 635 636 for (i = 0; i < RTAX_MAX; i++) { 637 if (test_bit(i, mxc->mx_valid)) 638 mp[i] = mxc->mx[i]; 639 } 640 } 641 642 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 643 { 644 if (!mxc->mx) 645 return 0; 646 647 if (dst->flags & DST_HOST) { 648 u32 *mp = dst_metrics_write_ptr(dst); 649 650 if (unlikely(!mp)) 651 return -ENOMEM; 652 653 fib6_copy_metrics(mp, mxc); 654 } else { 655 dst_init_metrics(dst, mxc->mx, false); 656 657 /* We've stolen mx now. */ 658 mxc->mx = NULL; 659 } 660 661 return 0; 662 } 663 664 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 665 struct net *net) 666 { 667 if (atomic_read(&rt->rt6i_ref) != 1) { 668 /* This route is used as dummy address holder in some split 669 * nodes. It is not leaked, but it still holds other resources, 670 * which must be released in time. So, scan ascendant nodes 671 * and replace dummy references to this route with references 672 * to still alive ones. 673 */ 674 while (fn) { 675 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 676 fn->leaf = fib6_find_prefix(net, fn); 677 atomic_inc(&fn->leaf->rt6i_ref); 678 rt6_release(rt); 679 } 680 fn = fn->parent; 681 } 682 /* No more references are possible at this point. */ 683 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 684 } 685 } 686 687 /* 688 * Insert routing information in a node. 689 */ 690 691 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 692 struct nl_info *info, struct mx6_config *mxc) 693 { 694 struct rt6_info *iter = NULL; 695 struct rt6_info **ins; 696 int replace = (info->nlh && 697 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 698 int add = (!info->nlh || 699 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 700 int found = 0; 701 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 702 int err; 703 704 ins = &fn->leaf; 705 706 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 707 /* 708 * Search for duplicates 709 */ 710 711 if (iter->rt6i_metric == rt->rt6i_metric) { 712 /* 713 * Same priority level 714 */ 715 if (info->nlh && 716 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 717 return -EEXIST; 718 if (replace) { 719 found++; 720 break; 721 } 722 723 if (iter->dst.dev == rt->dst.dev && 724 iter->rt6i_idev == rt->rt6i_idev && 725 ipv6_addr_equal(&iter->rt6i_gateway, 726 &rt->rt6i_gateway)) { 727 if (rt->rt6i_nsiblings) 728 rt->rt6i_nsiblings = 0; 729 if (!(iter->rt6i_flags & RTF_EXPIRES)) 730 return -EEXIST; 731 if (!(rt->rt6i_flags & RTF_EXPIRES)) 732 rt6_clean_expires(iter); 733 else 734 rt6_set_expires(iter, rt->dst.expires); 735 return -EEXIST; 736 } 737 /* If we have the same destination and the same metric, 738 * but not the same gateway, then the route we try to 739 * add is sibling to this route, increment our counter 740 * of siblings, and later we will add our route to the 741 * list. 742 * Only static routes (which don't have flag 743 * RTF_EXPIRES) are used for ECMPv6. 744 * 745 * To avoid long list, we only had siblings if the 746 * route have a gateway. 747 */ 748 if (rt_can_ecmp && 749 rt6_qualify_for_ecmp(iter)) 750 rt->rt6i_nsiblings++; 751 } 752 753 if (iter->rt6i_metric > rt->rt6i_metric) 754 break; 755 756 ins = &iter->dst.rt6_next; 757 } 758 759 /* Reset round-robin state, if necessary */ 760 if (ins == &fn->leaf) 761 fn->rr_ptr = NULL; 762 763 /* Link this route to others same route. */ 764 if (rt->rt6i_nsiblings) { 765 unsigned int rt6i_nsiblings; 766 struct rt6_info *sibling, *temp_sibling; 767 768 /* Find the first route that have the same metric */ 769 sibling = fn->leaf; 770 while (sibling) { 771 if (sibling->rt6i_metric == rt->rt6i_metric && 772 rt6_qualify_for_ecmp(sibling)) { 773 list_add_tail(&rt->rt6i_siblings, 774 &sibling->rt6i_siblings); 775 break; 776 } 777 sibling = sibling->dst.rt6_next; 778 } 779 /* For each sibling in the list, increment the counter of 780 * siblings. BUG() if counters does not match, list of siblings 781 * is broken! 782 */ 783 rt6i_nsiblings = 0; 784 list_for_each_entry_safe(sibling, temp_sibling, 785 &rt->rt6i_siblings, rt6i_siblings) { 786 sibling->rt6i_nsiblings++; 787 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 788 rt6i_nsiblings++; 789 } 790 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 791 } 792 793 /* 794 * insert node 795 */ 796 if (!replace) { 797 if (!add) 798 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 799 800 add: 801 err = fib6_commit_metrics(&rt->dst, mxc); 802 if (err) 803 return err; 804 805 rt->dst.rt6_next = iter; 806 *ins = rt; 807 rt->rt6i_node = fn; 808 atomic_inc(&rt->rt6i_ref); 809 inet6_rt_notify(RTM_NEWROUTE, rt, info); 810 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 811 812 if (!(fn->fn_flags & RTN_RTINFO)) { 813 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 814 fn->fn_flags |= RTN_RTINFO; 815 } 816 817 } else { 818 if (!found) { 819 if (add) 820 goto add; 821 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 822 return -ENOENT; 823 } 824 825 err = fib6_commit_metrics(&rt->dst, mxc); 826 if (err) 827 return err; 828 829 *ins = rt; 830 rt->rt6i_node = fn; 831 rt->dst.rt6_next = iter->dst.rt6_next; 832 atomic_inc(&rt->rt6i_ref); 833 inet6_rt_notify(RTM_NEWROUTE, rt, info); 834 if (!(fn->fn_flags & RTN_RTINFO)) { 835 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 836 fn->fn_flags |= RTN_RTINFO; 837 } 838 fib6_purge_rt(iter, fn, info->nl_net); 839 rt6_release(iter); 840 } 841 842 return 0; 843 } 844 845 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 846 { 847 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 848 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 849 mod_timer(&net->ipv6.ip6_fib_timer, 850 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 851 } 852 853 void fib6_force_start_gc(struct net *net) 854 { 855 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 856 mod_timer(&net->ipv6.ip6_fib_timer, 857 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 858 } 859 860 /* 861 * Add routing information to the routing tree. 862 * <destination addr>/<source addr> 863 * with source addr info in sub-trees 864 */ 865 866 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 867 struct nl_info *info, struct mx6_config *mxc) 868 { 869 struct fib6_node *fn, *pn = NULL; 870 int err = -ENOMEM; 871 int allow_create = 1; 872 int replace_required = 0; 873 int sernum = fib6_new_sernum(info->nl_net); 874 875 if (info->nlh) { 876 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 877 allow_create = 0; 878 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 879 replace_required = 1; 880 } 881 if (!allow_create && !replace_required) 882 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 883 884 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 885 offsetof(struct rt6_info, rt6i_dst), allow_create, 886 replace_required, sernum); 887 if (IS_ERR(fn)) { 888 err = PTR_ERR(fn); 889 fn = NULL; 890 goto out; 891 } 892 893 pn = fn; 894 895 #ifdef CONFIG_IPV6_SUBTREES 896 if (rt->rt6i_src.plen) { 897 struct fib6_node *sn; 898 899 if (!fn->subtree) { 900 struct fib6_node *sfn; 901 902 /* 903 * Create subtree. 904 * 905 * fn[main tree] 906 * | 907 * sfn[subtree root] 908 * \ 909 * sn[new leaf node] 910 */ 911 912 /* Create subtree root node */ 913 sfn = node_alloc(); 914 if (!sfn) 915 goto st_failure; 916 917 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 918 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 919 sfn->fn_flags = RTN_ROOT; 920 sfn->fn_sernum = sernum; 921 922 /* Now add the first leaf node to new subtree */ 923 924 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 925 rt->rt6i_src.plen, 926 offsetof(struct rt6_info, rt6i_src), 927 allow_create, replace_required, sernum); 928 929 if (IS_ERR(sn)) { 930 /* If it is failed, discard just allocated 931 root, and then (in st_failure) stale node 932 in main tree. 933 */ 934 node_free(sfn); 935 err = PTR_ERR(sn); 936 goto st_failure; 937 } 938 939 /* Now link new subtree to main tree */ 940 sfn->parent = fn; 941 fn->subtree = sfn; 942 } else { 943 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 944 rt->rt6i_src.plen, 945 offsetof(struct rt6_info, rt6i_src), 946 allow_create, replace_required, sernum); 947 948 if (IS_ERR(sn)) { 949 err = PTR_ERR(sn); 950 goto st_failure; 951 } 952 } 953 954 if (!fn->leaf) { 955 fn->leaf = rt; 956 atomic_inc(&rt->rt6i_ref); 957 } 958 fn = sn; 959 } 960 #endif 961 962 err = fib6_add_rt2node(fn, rt, info, mxc); 963 if (!err) { 964 fib6_start_gc(info->nl_net, rt); 965 if (!(rt->rt6i_flags & RTF_CACHE)) 966 fib6_prune_clones(info->nl_net, pn); 967 } 968 969 out: 970 if (err) { 971 #ifdef CONFIG_IPV6_SUBTREES 972 /* 973 * If fib6_add_1 has cleared the old leaf pointer in the 974 * super-tree leaf node we have to find a new one for it. 975 */ 976 if (pn != fn && pn->leaf == rt) { 977 pn->leaf = NULL; 978 atomic_dec(&rt->rt6i_ref); 979 } 980 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 981 pn->leaf = fib6_find_prefix(info->nl_net, pn); 982 #if RT6_DEBUG >= 2 983 if (!pn->leaf) { 984 WARN_ON(pn->leaf == NULL); 985 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 986 } 987 #endif 988 atomic_inc(&pn->leaf->rt6i_ref); 989 } 990 #endif 991 dst_free(&rt->dst); 992 } 993 return err; 994 995 #ifdef CONFIG_IPV6_SUBTREES 996 /* Subtree creation failed, probably main tree node 997 is orphan. If it is, shoot it. 998 */ 999 st_failure: 1000 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1001 fib6_repair_tree(info->nl_net, fn); 1002 dst_free(&rt->dst); 1003 return err; 1004 #endif 1005 } 1006 1007 /* 1008 * Routing tree lookup 1009 * 1010 */ 1011 1012 struct lookup_args { 1013 int offset; /* key offset on rt6_info */ 1014 const struct in6_addr *addr; /* search key */ 1015 }; 1016 1017 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1018 struct lookup_args *args) 1019 { 1020 struct fib6_node *fn; 1021 __be32 dir; 1022 1023 if (unlikely(args->offset == 0)) 1024 return NULL; 1025 1026 /* 1027 * Descend on a tree 1028 */ 1029 1030 fn = root; 1031 1032 for (;;) { 1033 struct fib6_node *next; 1034 1035 dir = addr_bit_set(args->addr, fn->fn_bit); 1036 1037 next = dir ? fn->right : fn->left; 1038 1039 if (next) { 1040 fn = next; 1041 continue; 1042 } 1043 break; 1044 } 1045 1046 while (fn) { 1047 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1048 struct rt6key *key; 1049 1050 key = (struct rt6key *) ((u8 *) fn->leaf + 1051 args->offset); 1052 1053 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1054 #ifdef CONFIG_IPV6_SUBTREES 1055 if (fn->subtree) { 1056 struct fib6_node *sfn; 1057 sfn = fib6_lookup_1(fn->subtree, 1058 args + 1); 1059 if (!sfn) 1060 goto backtrack; 1061 fn = sfn; 1062 } 1063 #endif 1064 if (fn->fn_flags & RTN_RTINFO) 1065 return fn; 1066 } 1067 } 1068 #ifdef CONFIG_IPV6_SUBTREES 1069 backtrack: 1070 #endif 1071 if (fn->fn_flags & RTN_ROOT) 1072 break; 1073 1074 fn = fn->parent; 1075 } 1076 1077 return NULL; 1078 } 1079 1080 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1081 const struct in6_addr *saddr) 1082 { 1083 struct fib6_node *fn; 1084 struct lookup_args args[] = { 1085 { 1086 .offset = offsetof(struct rt6_info, rt6i_dst), 1087 .addr = daddr, 1088 }, 1089 #ifdef CONFIG_IPV6_SUBTREES 1090 { 1091 .offset = offsetof(struct rt6_info, rt6i_src), 1092 .addr = saddr, 1093 }, 1094 #endif 1095 { 1096 .offset = 0, /* sentinel */ 1097 } 1098 }; 1099 1100 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1101 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1102 fn = root; 1103 1104 return fn; 1105 } 1106 1107 /* 1108 * Get node with specified destination prefix (and source prefix, 1109 * if subtrees are used) 1110 */ 1111 1112 1113 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1114 const struct in6_addr *addr, 1115 int plen, int offset) 1116 { 1117 struct fib6_node *fn; 1118 1119 for (fn = root; fn ; ) { 1120 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1121 1122 /* 1123 * Prefix match 1124 */ 1125 if (plen < fn->fn_bit || 1126 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1127 return NULL; 1128 1129 if (plen == fn->fn_bit) 1130 return fn; 1131 1132 /* 1133 * We have more bits to go 1134 */ 1135 if (addr_bit_set(addr, fn->fn_bit)) 1136 fn = fn->right; 1137 else 1138 fn = fn->left; 1139 } 1140 return NULL; 1141 } 1142 1143 struct fib6_node *fib6_locate(struct fib6_node *root, 1144 const struct in6_addr *daddr, int dst_len, 1145 const struct in6_addr *saddr, int src_len) 1146 { 1147 struct fib6_node *fn; 1148 1149 fn = fib6_locate_1(root, daddr, dst_len, 1150 offsetof(struct rt6_info, rt6i_dst)); 1151 1152 #ifdef CONFIG_IPV6_SUBTREES 1153 if (src_len) { 1154 WARN_ON(saddr == NULL); 1155 if (fn && fn->subtree) 1156 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1157 offsetof(struct rt6_info, rt6i_src)); 1158 } 1159 #endif 1160 1161 if (fn && fn->fn_flags & RTN_RTINFO) 1162 return fn; 1163 1164 return NULL; 1165 } 1166 1167 1168 /* 1169 * Deletion 1170 * 1171 */ 1172 1173 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1174 { 1175 if (fn->fn_flags & RTN_ROOT) 1176 return net->ipv6.ip6_null_entry; 1177 1178 while (fn) { 1179 if (fn->left) 1180 return fn->left->leaf; 1181 if (fn->right) 1182 return fn->right->leaf; 1183 1184 fn = FIB6_SUBTREE(fn); 1185 } 1186 return NULL; 1187 } 1188 1189 /* 1190 * Called to trim the tree of intermediate nodes when possible. "fn" 1191 * is the node we want to try and remove. 1192 */ 1193 1194 static struct fib6_node *fib6_repair_tree(struct net *net, 1195 struct fib6_node *fn) 1196 { 1197 int children; 1198 int nstate; 1199 struct fib6_node *child, *pn; 1200 struct fib6_walker *w; 1201 int iter = 0; 1202 1203 for (;;) { 1204 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1205 iter++; 1206 1207 WARN_ON(fn->fn_flags & RTN_RTINFO); 1208 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1209 WARN_ON(fn->leaf != NULL); 1210 1211 children = 0; 1212 child = NULL; 1213 if (fn->right) 1214 child = fn->right, children |= 1; 1215 if (fn->left) 1216 child = fn->left, children |= 2; 1217 1218 if (children == 3 || FIB6_SUBTREE(fn) 1219 #ifdef CONFIG_IPV6_SUBTREES 1220 /* Subtree root (i.e. fn) may have one child */ 1221 || (children && fn->fn_flags & RTN_ROOT) 1222 #endif 1223 ) { 1224 fn->leaf = fib6_find_prefix(net, fn); 1225 #if RT6_DEBUG >= 2 1226 if (!fn->leaf) { 1227 WARN_ON(!fn->leaf); 1228 fn->leaf = net->ipv6.ip6_null_entry; 1229 } 1230 #endif 1231 atomic_inc(&fn->leaf->rt6i_ref); 1232 return fn->parent; 1233 } 1234 1235 pn = fn->parent; 1236 #ifdef CONFIG_IPV6_SUBTREES 1237 if (FIB6_SUBTREE(pn) == fn) { 1238 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1239 FIB6_SUBTREE(pn) = NULL; 1240 nstate = FWS_L; 1241 } else { 1242 WARN_ON(fn->fn_flags & RTN_ROOT); 1243 #endif 1244 if (pn->right == fn) 1245 pn->right = child; 1246 else if (pn->left == fn) 1247 pn->left = child; 1248 #if RT6_DEBUG >= 2 1249 else 1250 WARN_ON(1); 1251 #endif 1252 if (child) 1253 child->parent = pn; 1254 nstate = FWS_R; 1255 #ifdef CONFIG_IPV6_SUBTREES 1256 } 1257 #endif 1258 1259 read_lock(&fib6_walker_lock); 1260 FOR_WALKERS(w) { 1261 if (!child) { 1262 if (w->root == fn) { 1263 w->root = w->node = NULL; 1264 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1265 } else if (w->node == fn) { 1266 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1267 w->node = pn; 1268 w->state = nstate; 1269 } 1270 } else { 1271 if (w->root == fn) { 1272 w->root = child; 1273 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1274 } 1275 if (w->node == fn) { 1276 w->node = child; 1277 if (children&2) { 1278 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1279 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1280 } else { 1281 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1282 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1283 } 1284 } 1285 } 1286 } 1287 read_unlock(&fib6_walker_lock); 1288 1289 node_free(fn); 1290 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1291 return pn; 1292 1293 rt6_release(pn->leaf); 1294 pn->leaf = NULL; 1295 fn = pn; 1296 } 1297 } 1298 1299 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1300 struct nl_info *info) 1301 { 1302 struct fib6_walker *w; 1303 struct rt6_info *rt = *rtp; 1304 struct net *net = info->nl_net; 1305 1306 RT6_TRACE("fib6_del_route\n"); 1307 1308 /* Unlink it */ 1309 *rtp = rt->dst.rt6_next; 1310 rt->rt6i_node = NULL; 1311 net->ipv6.rt6_stats->fib_rt_entries--; 1312 net->ipv6.rt6_stats->fib_discarded_routes++; 1313 1314 /* Reset round-robin state, if necessary */ 1315 if (fn->rr_ptr == rt) 1316 fn->rr_ptr = NULL; 1317 1318 /* Remove this entry from other siblings */ 1319 if (rt->rt6i_nsiblings) { 1320 struct rt6_info *sibling, *next_sibling; 1321 1322 list_for_each_entry_safe(sibling, next_sibling, 1323 &rt->rt6i_siblings, rt6i_siblings) 1324 sibling->rt6i_nsiblings--; 1325 rt->rt6i_nsiblings = 0; 1326 list_del_init(&rt->rt6i_siblings); 1327 } 1328 1329 /* Adjust walkers */ 1330 read_lock(&fib6_walker_lock); 1331 FOR_WALKERS(w) { 1332 if (w->state == FWS_C && w->leaf == rt) { 1333 RT6_TRACE("walker %p adjusted by delroute\n", w); 1334 w->leaf = rt->dst.rt6_next; 1335 if (!w->leaf) 1336 w->state = FWS_U; 1337 } 1338 } 1339 read_unlock(&fib6_walker_lock); 1340 1341 rt->dst.rt6_next = NULL; 1342 1343 /* If it was last route, expunge its radix tree node */ 1344 if (!fn->leaf) { 1345 fn->fn_flags &= ~RTN_RTINFO; 1346 net->ipv6.rt6_stats->fib_route_nodes--; 1347 fn = fib6_repair_tree(net, fn); 1348 } 1349 1350 fib6_purge_rt(rt, fn, net); 1351 1352 inet6_rt_notify(RTM_DELROUTE, rt, info); 1353 rt6_release(rt); 1354 } 1355 1356 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1357 { 1358 struct net *net = info->nl_net; 1359 struct fib6_node *fn = rt->rt6i_node; 1360 struct rt6_info **rtp; 1361 1362 #if RT6_DEBUG >= 2 1363 if (rt->dst.obsolete > 0) { 1364 WARN_ON(fn != NULL); 1365 return -ENOENT; 1366 } 1367 #endif 1368 if (!fn || rt == net->ipv6.ip6_null_entry) 1369 return -ENOENT; 1370 1371 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1372 1373 if (!(rt->rt6i_flags & RTF_CACHE)) { 1374 struct fib6_node *pn = fn; 1375 #ifdef CONFIG_IPV6_SUBTREES 1376 /* clones of this route might be in another subtree */ 1377 if (rt->rt6i_src.plen) { 1378 while (!(pn->fn_flags & RTN_ROOT)) 1379 pn = pn->parent; 1380 pn = pn->parent; 1381 } 1382 #endif 1383 fib6_prune_clones(info->nl_net, pn); 1384 } 1385 1386 /* 1387 * Walk the leaf entries looking for ourself 1388 */ 1389 1390 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1391 if (*rtp == rt) { 1392 fib6_del_route(fn, rtp, info); 1393 return 0; 1394 } 1395 } 1396 return -ENOENT; 1397 } 1398 1399 /* 1400 * Tree traversal function. 1401 * 1402 * Certainly, it is not interrupt safe. 1403 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1404 * It means, that we can modify tree during walking 1405 * and use this function for garbage collection, clone pruning, 1406 * cleaning tree when a device goes down etc. etc. 1407 * 1408 * It guarantees that every node will be traversed, 1409 * and that it will be traversed only once. 1410 * 1411 * Callback function w->func may return: 1412 * 0 -> continue walking. 1413 * positive value -> walking is suspended (used by tree dumps, 1414 * and probably by gc, if it will be split to several slices) 1415 * negative value -> terminate walking. 1416 * 1417 * The function itself returns: 1418 * 0 -> walk is complete. 1419 * >0 -> walk is incomplete (i.e. suspended) 1420 * <0 -> walk is terminated by an error. 1421 */ 1422 1423 static int fib6_walk_continue(struct fib6_walker *w) 1424 { 1425 struct fib6_node *fn, *pn; 1426 1427 for (;;) { 1428 fn = w->node; 1429 if (!fn) 1430 return 0; 1431 1432 if (w->prune && fn != w->root && 1433 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1434 w->state = FWS_C; 1435 w->leaf = fn->leaf; 1436 } 1437 switch (w->state) { 1438 #ifdef CONFIG_IPV6_SUBTREES 1439 case FWS_S: 1440 if (FIB6_SUBTREE(fn)) { 1441 w->node = FIB6_SUBTREE(fn); 1442 continue; 1443 } 1444 w->state = FWS_L; 1445 #endif 1446 case FWS_L: 1447 if (fn->left) { 1448 w->node = fn->left; 1449 w->state = FWS_INIT; 1450 continue; 1451 } 1452 w->state = FWS_R; 1453 case FWS_R: 1454 if (fn->right) { 1455 w->node = fn->right; 1456 w->state = FWS_INIT; 1457 continue; 1458 } 1459 w->state = FWS_C; 1460 w->leaf = fn->leaf; 1461 case FWS_C: 1462 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1463 int err; 1464 1465 if (w->skip) { 1466 w->skip--; 1467 goto skip; 1468 } 1469 1470 err = w->func(w); 1471 if (err) 1472 return err; 1473 1474 w->count++; 1475 continue; 1476 } 1477 skip: 1478 w->state = FWS_U; 1479 case FWS_U: 1480 if (fn == w->root) 1481 return 0; 1482 pn = fn->parent; 1483 w->node = pn; 1484 #ifdef CONFIG_IPV6_SUBTREES 1485 if (FIB6_SUBTREE(pn) == fn) { 1486 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1487 w->state = FWS_L; 1488 continue; 1489 } 1490 #endif 1491 if (pn->left == fn) { 1492 w->state = FWS_R; 1493 continue; 1494 } 1495 if (pn->right == fn) { 1496 w->state = FWS_C; 1497 w->leaf = w->node->leaf; 1498 continue; 1499 } 1500 #if RT6_DEBUG >= 2 1501 WARN_ON(1); 1502 #endif 1503 } 1504 } 1505 } 1506 1507 static int fib6_walk(struct fib6_walker *w) 1508 { 1509 int res; 1510 1511 w->state = FWS_INIT; 1512 w->node = w->root; 1513 1514 fib6_walker_link(w); 1515 res = fib6_walk_continue(w); 1516 if (res <= 0) 1517 fib6_walker_unlink(w); 1518 return res; 1519 } 1520 1521 static int fib6_clean_node(struct fib6_walker *w) 1522 { 1523 int res; 1524 struct rt6_info *rt; 1525 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1526 struct nl_info info = { 1527 .nl_net = c->net, 1528 }; 1529 1530 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1531 w->node->fn_sernum != c->sernum) 1532 w->node->fn_sernum = c->sernum; 1533 1534 if (!c->func) { 1535 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1536 w->leaf = NULL; 1537 return 0; 1538 } 1539 1540 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1541 res = c->func(rt, c->arg); 1542 if (res < 0) { 1543 w->leaf = rt; 1544 res = fib6_del(rt, &info); 1545 if (res) { 1546 #if RT6_DEBUG >= 2 1547 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1548 __func__, rt, rt->rt6i_node, res); 1549 #endif 1550 continue; 1551 } 1552 return 0; 1553 } 1554 WARN_ON(res != 0); 1555 } 1556 w->leaf = rt; 1557 return 0; 1558 } 1559 1560 /* 1561 * Convenient frontend to tree walker. 1562 * 1563 * func is called on each route. 1564 * It may return -1 -> delete this route. 1565 * 0 -> continue walking 1566 * 1567 * prune==1 -> only immediate children of node (certainly, 1568 * ignoring pure split nodes) will be scanned. 1569 */ 1570 1571 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1572 int (*func)(struct rt6_info *, void *arg), 1573 bool prune, int sernum, void *arg) 1574 { 1575 struct fib6_cleaner c; 1576 1577 c.w.root = root; 1578 c.w.func = fib6_clean_node; 1579 c.w.prune = prune; 1580 c.w.count = 0; 1581 c.w.skip = 0; 1582 c.func = func; 1583 c.sernum = sernum; 1584 c.arg = arg; 1585 c.net = net; 1586 1587 fib6_walk(&c.w); 1588 } 1589 1590 static void __fib6_clean_all(struct net *net, 1591 int (*func)(struct rt6_info *, void *), 1592 int sernum, void *arg) 1593 { 1594 struct fib6_table *table; 1595 struct hlist_head *head; 1596 unsigned int h; 1597 1598 rcu_read_lock(); 1599 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1600 head = &net->ipv6.fib_table_hash[h]; 1601 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1602 write_lock_bh(&table->tb6_lock); 1603 fib6_clean_tree(net, &table->tb6_root, 1604 func, false, sernum, arg); 1605 write_unlock_bh(&table->tb6_lock); 1606 } 1607 } 1608 rcu_read_unlock(); 1609 } 1610 1611 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1612 void *arg) 1613 { 1614 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1615 } 1616 1617 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1618 { 1619 if (rt->rt6i_flags & RTF_CACHE) { 1620 RT6_TRACE("pruning clone %p\n", rt); 1621 return -1; 1622 } 1623 1624 return 0; 1625 } 1626 1627 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1628 { 1629 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1630 FIB6_NO_SERNUM_CHANGE, NULL); 1631 } 1632 1633 static void fib6_flush_trees(struct net *net) 1634 { 1635 int new_sernum = fib6_new_sernum(net); 1636 1637 __fib6_clean_all(net, NULL, new_sernum, NULL); 1638 } 1639 1640 /* 1641 * Garbage collection 1642 */ 1643 1644 static struct fib6_gc_args 1645 { 1646 int timeout; 1647 int more; 1648 } gc_args; 1649 1650 static int fib6_age(struct rt6_info *rt, void *arg) 1651 { 1652 unsigned long now = jiffies; 1653 1654 /* 1655 * check addrconf expiration here. 1656 * Routes are expired even if they are in use. 1657 * 1658 * Also age clones. Note, that clones are aged out 1659 * only if they are not in use now. 1660 */ 1661 1662 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1663 if (time_after(now, rt->dst.expires)) { 1664 RT6_TRACE("expiring %p\n", rt); 1665 return -1; 1666 } 1667 gc_args.more++; 1668 } else if (rt->rt6i_flags & RTF_CACHE) { 1669 if (atomic_read(&rt->dst.__refcnt) == 0 && 1670 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1671 RT6_TRACE("aging clone %p\n", rt); 1672 return -1; 1673 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1674 struct neighbour *neigh; 1675 __u8 neigh_flags = 0; 1676 1677 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1678 if (neigh) { 1679 neigh_flags = neigh->flags; 1680 neigh_release(neigh); 1681 } 1682 if (!(neigh_flags & NTF_ROUTER)) { 1683 RT6_TRACE("purging route %p via non-router but gateway\n", 1684 rt); 1685 return -1; 1686 } 1687 } 1688 gc_args.more++; 1689 } 1690 1691 return 0; 1692 } 1693 1694 static DEFINE_SPINLOCK(fib6_gc_lock); 1695 1696 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1697 { 1698 unsigned long now; 1699 1700 if (force) { 1701 spin_lock_bh(&fib6_gc_lock); 1702 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1703 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1704 return; 1705 } 1706 gc_args.timeout = expires ? (int)expires : 1707 net->ipv6.sysctl.ip6_rt_gc_interval; 1708 1709 gc_args.more = icmp6_dst_gc(); 1710 1711 fib6_clean_all(net, fib6_age, NULL); 1712 now = jiffies; 1713 net->ipv6.ip6_rt_last_gc = now; 1714 1715 if (gc_args.more) 1716 mod_timer(&net->ipv6.ip6_fib_timer, 1717 round_jiffies(now 1718 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1719 else 1720 del_timer(&net->ipv6.ip6_fib_timer); 1721 spin_unlock_bh(&fib6_gc_lock); 1722 } 1723 1724 static void fib6_gc_timer_cb(unsigned long arg) 1725 { 1726 fib6_run_gc(0, (struct net *)arg, true); 1727 } 1728 1729 static int __net_init fib6_net_init(struct net *net) 1730 { 1731 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1732 1733 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1734 1735 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1736 if (!net->ipv6.rt6_stats) 1737 goto out_timer; 1738 1739 /* Avoid false sharing : Use at least a full cache line */ 1740 size = max_t(size_t, size, L1_CACHE_BYTES); 1741 1742 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1743 if (!net->ipv6.fib_table_hash) 1744 goto out_rt6_stats; 1745 1746 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1747 GFP_KERNEL); 1748 if (!net->ipv6.fib6_main_tbl) 1749 goto out_fib_table_hash; 1750 1751 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1752 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1753 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1754 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1755 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1756 1757 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1758 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1759 GFP_KERNEL); 1760 if (!net->ipv6.fib6_local_tbl) 1761 goto out_fib6_main_tbl; 1762 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1763 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1764 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1765 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1766 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1767 #endif 1768 fib6_tables_init(net); 1769 1770 return 0; 1771 1772 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1773 out_fib6_main_tbl: 1774 kfree(net->ipv6.fib6_main_tbl); 1775 #endif 1776 out_fib_table_hash: 1777 kfree(net->ipv6.fib_table_hash); 1778 out_rt6_stats: 1779 kfree(net->ipv6.rt6_stats); 1780 out_timer: 1781 return -ENOMEM; 1782 } 1783 1784 static void fib6_net_exit(struct net *net) 1785 { 1786 rt6_ifdown(net, NULL); 1787 del_timer_sync(&net->ipv6.ip6_fib_timer); 1788 1789 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1790 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1791 kfree(net->ipv6.fib6_local_tbl); 1792 #endif 1793 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1794 kfree(net->ipv6.fib6_main_tbl); 1795 kfree(net->ipv6.fib_table_hash); 1796 kfree(net->ipv6.rt6_stats); 1797 } 1798 1799 static struct pernet_operations fib6_net_ops = { 1800 .init = fib6_net_init, 1801 .exit = fib6_net_exit, 1802 }; 1803 1804 int __init fib6_init(void) 1805 { 1806 int ret = -ENOMEM; 1807 1808 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1809 sizeof(struct fib6_node), 1810 0, SLAB_HWCACHE_ALIGN, 1811 NULL); 1812 if (!fib6_node_kmem) 1813 goto out; 1814 1815 ret = register_pernet_subsys(&fib6_net_ops); 1816 if (ret) 1817 goto out_kmem_cache_create; 1818 1819 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1820 NULL); 1821 if (ret) 1822 goto out_unregister_subsys; 1823 1824 __fib6_flush_trees = fib6_flush_trees; 1825 out: 1826 return ret; 1827 1828 out_unregister_subsys: 1829 unregister_pernet_subsys(&fib6_net_ops); 1830 out_kmem_cache_create: 1831 kmem_cache_destroy(fib6_node_kmem); 1832 goto out; 1833 } 1834 1835 void fib6_gc_cleanup(void) 1836 { 1837 unregister_pernet_subsys(&fib6_net_ops); 1838 kmem_cache_destroy(fib6_node_kmem); 1839 } 1840 1841 #ifdef CONFIG_PROC_FS 1842 1843 struct ipv6_route_iter { 1844 struct seq_net_private p; 1845 struct fib6_walker w; 1846 loff_t skip; 1847 struct fib6_table *tbl; 1848 int sernum; 1849 }; 1850 1851 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1852 { 1853 struct rt6_info *rt = v; 1854 struct ipv6_route_iter *iter = seq->private; 1855 1856 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1857 1858 #ifdef CONFIG_IPV6_SUBTREES 1859 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1860 #else 1861 seq_puts(seq, "00000000000000000000000000000000 00 "); 1862 #endif 1863 if (rt->rt6i_flags & RTF_GATEWAY) 1864 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1865 else 1866 seq_puts(seq, "00000000000000000000000000000000"); 1867 1868 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1869 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1870 rt->dst.__use, rt->rt6i_flags, 1871 rt->dst.dev ? rt->dst.dev->name : ""); 1872 iter->w.leaf = NULL; 1873 return 0; 1874 } 1875 1876 static int ipv6_route_yield(struct fib6_walker *w) 1877 { 1878 struct ipv6_route_iter *iter = w->args; 1879 1880 if (!iter->skip) 1881 return 1; 1882 1883 do { 1884 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1885 iter->skip--; 1886 if (!iter->skip && iter->w.leaf) 1887 return 1; 1888 } while (iter->w.leaf); 1889 1890 return 0; 1891 } 1892 1893 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1894 { 1895 memset(&iter->w, 0, sizeof(iter->w)); 1896 iter->w.func = ipv6_route_yield; 1897 iter->w.root = &iter->tbl->tb6_root; 1898 iter->w.state = FWS_INIT; 1899 iter->w.node = iter->w.root; 1900 iter->w.args = iter; 1901 iter->sernum = iter->w.root->fn_sernum; 1902 INIT_LIST_HEAD(&iter->w.lh); 1903 fib6_walker_link(&iter->w); 1904 } 1905 1906 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1907 struct net *net) 1908 { 1909 unsigned int h; 1910 struct hlist_node *node; 1911 1912 if (tbl) { 1913 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1914 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1915 } else { 1916 h = 0; 1917 node = NULL; 1918 } 1919 1920 while (!node && h < FIB6_TABLE_HASHSZ) { 1921 node = rcu_dereference_bh( 1922 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 1923 } 1924 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 1925 } 1926 1927 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 1928 { 1929 if (iter->sernum != iter->w.root->fn_sernum) { 1930 iter->sernum = iter->w.root->fn_sernum; 1931 iter->w.state = FWS_INIT; 1932 iter->w.node = iter->w.root; 1933 WARN_ON(iter->w.skip); 1934 iter->w.skip = iter->w.count; 1935 } 1936 } 1937 1938 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1939 { 1940 int r; 1941 struct rt6_info *n; 1942 struct net *net = seq_file_net(seq); 1943 struct ipv6_route_iter *iter = seq->private; 1944 1945 if (!v) 1946 goto iter_table; 1947 1948 n = ((struct rt6_info *)v)->dst.rt6_next; 1949 if (n) { 1950 ++*pos; 1951 return n; 1952 } 1953 1954 iter_table: 1955 ipv6_route_check_sernum(iter); 1956 read_lock(&iter->tbl->tb6_lock); 1957 r = fib6_walk_continue(&iter->w); 1958 read_unlock(&iter->tbl->tb6_lock); 1959 if (r > 0) { 1960 if (v) 1961 ++*pos; 1962 return iter->w.leaf; 1963 } else if (r < 0) { 1964 fib6_walker_unlink(&iter->w); 1965 return NULL; 1966 } 1967 fib6_walker_unlink(&iter->w); 1968 1969 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 1970 if (!iter->tbl) 1971 return NULL; 1972 1973 ipv6_route_seq_setup_walk(iter); 1974 goto iter_table; 1975 } 1976 1977 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 1978 __acquires(RCU_BH) 1979 { 1980 struct net *net = seq_file_net(seq); 1981 struct ipv6_route_iter *iter = seq->private; 1982 1983 rcu_read_lock_bh(); 1984 iter->tbl = ipv6_route_seq_next_table(NULL, net); 1985 iter->skip = *pos; 1986 1987 if (iter->tbl) { 1988 ipv6_route_seq_setup_walk(iter); 1989 return ipv6_route_seq_next(seq, NULL, pos); 1990 } else { 1991 return NULL; 1992 } 1993 } 1994 1995 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 1996 { 1997 struct fib6_walker *w = &iter->w; 1998 return w->node && !(w->state == FWS_U && w->node == w->root); 1999 } 2000 2001 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2002 __releases(RCU_BH) 2003 { 2004 struct ipv6_route_iter *iter = seq->private; 2005 2006 if (ipv6_route_iter_active(iter)) 2007 fib6_walker_unlink(&iter->w); 2008 2009 rcu_read_unlock_bh(); 2010 } 2011 2012 static const struct seq_operations ipv6_route_seq_ops = { 2013 .start = ipv6_route_seq_start, 2014 .next = ipv6_route_seq_next, 2015 .stop = ipv6_route_seq_stop, 2016 .show = ipv6_route_seq_show 2017 }; 2018 2019 int ipv6_route_open(struct inode *inode, struct file *file) 2020 { 2021 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2022 sizeof(struct ipv6_route_iter)); 2023 } 2024 2025 #endif /* CONFIG_PROC_FS */ 2026