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_free_pcpu(struct rt6_info *non_pcpu_rt) 158 { 159 int cpu; 160 161 if (!non_pcpu_rt->rt6i_pcpu) 162 return; 163 164 for_each_possible_cpu(cpu) { 165 struct rt6_info **ppcpu_rt; 166 struct rt6_info *pcpu_rt; 167 168 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 169 pcpu_rt = *ppcpu_rt; 170 if (pcpu_rt) { 171 dst_free(&pcpu_rt->dst); 172 *ppcpu_rt = NULL; 173 } 174 } 175 } 176 177 static void rt6_release(struct rt6_info *rt) 178 { 179 if (atomic_dec_and_test(&rt->rt6i_ref)) { 180 rt6_free_pcpu(rt); 181 dst_free(&rt->dst); 182 } 183 } 184 185 static void fib6_link_table(struct net *net, struct fib6_table *tb) 186 { 187 unsigned int h; 188 189 /* 190 * Initialize table lock at a single place to give lockdep a key, 191 * tables aren't visible prior to being linked to the list. 192 */ 193 rwlock_init(&tb->tb6_lock); 194 195 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 196 197 /* 198 * No protection necessary, this is the only list mutatation 199 * operation, tables never disappear once they exist. 200 */ 201 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 202 } 203 204 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 205 206 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 207 { 208 struct fib6_table *table; 209 210 table = kzalloc(sizeof(*table), GFP_ATOMIC); 211 if (table) { 212 table->tb6_id = id; 213 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 214 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 215 inet_peer_base_init(&table->tb6_peers); 216 } 217 218 return table; 219 } 220 221 struct fib6_table *fib6_new_table(struct net *net, u32 id) 222 { 223 struct fib6_table *tb; 224 225 if (id == 0) 226 id = RT6_TABLE_MAIN; 227 tb = fib6_get_table(net, id); 228 if (tb) 229 return tb; 230 231 tb = fib6_alloc_table(net, id); 232 if (tb) 233 fib6_link_table(net, tb); 234 235 return tb; 236 } 237 238 struct fib6_table *fib6_get_table(struct net *net, u32 id) 239 { 240 struct fib6_table *tb; 241 struct hlist_head *head; 242 unsigned int h; 243 244 if (id == 0) 245 id = RT6_TABLE_MAIN; 246 h = id & (FIB6_TABLE_HASHSZ - 1); 247 rcu_read_lock(); 248 head = &net->ipv6.fib_table_hash[h]; 249 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 250 if (tb->tb6_id == id) { 251 rcu_read_unlock(); 252 return tb; 253 } 254 } 255 rcu_read_unlock(); 256 257 return NULL; 258 } 259 260 static void __net_init fib6_tables_init(struct net *net) 261 { 262 fib6_link_table(net, net->ipv6.fib6_main_tbl); 263 fib6_link_table(net, net->ipv6.fib6_local_tbl); 264 } 265 #else 266 267 struct fib6_table *fib6_new_table(struct net *net, u32 id) 268 { 269 return fib6_get_table(net, id); 270 } 271 272 struct fib6_table *fib6_get_table(struct net *net, u32 id) 273 { 274 return net->ipv6.fib6_main_tbl; 275 } 276 277 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 278 int flags, pol_lookup_t lookup) 279 { 280 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 281 } 282 283 static void __net_init fib6_tables_init(struct net *net) 284 { 285 fib6_link_table(net, net->ipv6.fib6_main_tbl); 286 } 287 288 #endif 289 290 static int fib6_dump_node(struct fib6_walker *w) 291 { 292 int res; 293 struct rt6_info *rt; 294 295 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 296 res = rt6_dump_route(rt, w->args); 297 if (res < 0) { 298 /* Frame is full, suspend walking */ 299 w->leaf = rt; 300 return 1; 301 } 302 } 303 w->leaf = NULL; 304 return 0; 305 } 306 307 static void fib6_dump_end(struct netlink_callback *cb) 308 { 309 struct fib6_walker *w = (void *)cb->args[2]; 310 311 if (w) { 312 if (cb->args[4]) { 313 cb->args[4] = 0; 314 fib6_walker_unlink(w); 315 } 316 cb->args[2] = 0; 317 kfree(w); 318 } 319 cb->done = (void *)cb->args[3]; 320 cb->args[1] = 3; 321 } 322 323 static int fib6_dump_done(struct netlink_callback *cb) 324 { 325 fib6_dump_end(cb); 326 return cb->done ? cb->done(cb) : 0; 327 } 328 329 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 330 struct netlink_callback *cb) 331 { 332 struct fib6_walker *w; 333 int res; 334 335 w = (void *)cb->args[2]; 336 w->root = &table->tb6_root; 337 338 if (cb->args[4] == 0) { 339 w->count = 0; 340 w->skip = 0; 341 342 read_lock_bh(&table->tb6_lock); 343 res = fib6_walk(w); 344 read_unlock_bh(&table->tb6_lock); 345 if (res > 0) { 346 cb->args[4] = 1; 347 cb->args[5] = w->root->fn_sernum; 348 } 349 } else { 350 if (cb->args[5] != w->root->fn_sernum) { 351 /* Begin at the root if the tree changed */ 352 cb->args[5] = w->root->fn_sernum; 353 w->state = FWS_INIT; 354 w->node = w->root; 355 w->skip = w->count; 356 } else 357 w->skip = 0; 358 359 read_lock_bh(&table->tb6_lock); 360 res = fib6_walk_continue(w); 361 read_unlock_bh(&table->tb6_lock); 362 if (res <= 0) { 363 fib6_walker_unlink(w); 364 cb->args[4] = 0; 365 } 366 } 367 368 return res; 369 } 370 371 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 372 { 373 struct net *net = sock_net(skb->sk); 374 unsigned int h, s_h; 375 unsigned int e = 0, s_e; 376 struct rt6_rtnl_dump_arg arg; 377 struct fib6_walker *w; 378 struct fib6_table *tb; 379 struct hlist_head *head; 380 int res = 0; 381 382 s_h = cb->args[0]; 383 s_e = cb->args[1]; 384 385 w = (void *)cb->args[2]; 386 if (!w) { 387 /* New dump: 388 * 389 * 1. hook callback destructor. 390 */ 391 cb->args[3] = (long)cb->done; 392 cb->done = fib6_dump_done; 393 394 /* 395 * 2. allocate and initialize walker. 396 */ 397 w = kzalloc(sizeof(*w), GFP_ATOMIC); 398 if (!w) 399 return -ENOMEM; 400 w->func = fib6_dump_node; 401 cb->args[2] = (long)w; 402 } 403 404 arg.skb = skb; 405 arg.cb = cb; 406 arg.net = net; 407 w->args = &arg; 408 409 rcu_read_lock(); 410 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 411 e = 0; 412 head = &net->ipv6.fib_table_hash[h]; 413 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 414 if (e < s_e) 415 goto next; 416 res = fib6_dump_table(tb, skb, cb); 417 if (res != 0) 418 goto out; 419 next: 420 e++; 421 } 422 } 423 out: 424 rcu_read_unlock(); 425 cb->args[1] = e; 426 cb->args[0] = h; 427 428 res = res < 0 ? res : skb->len; 429 if (res <= 0) 430 fib6_dump_end(cb); 431 return res; 432 } 433 434 /* 435 * Routing Table 436 * 437 * return the appropriate node for a routing tree "add" operation 438 * by either creating and inserting or by returning an existing 439 * node. 440 */ 441 442 static struct fib6_node *fib6_add_1(struct fib6_node *root, 443 struct in6_addr *addr, int plen, 444 int offset, int allow_create, 445 int replace_required, int sernum) 446 { 447 struct fib6_node *fn, *in, *ln; 448 struct fib6_node *pn = NULL; 449 struct rt6key *key; 450 int bit; 451 __be32 dir = 0; 452 453 RT6_TRACE("fib6_add_1\n"); 454 455 /* insert node in tree */ 456 457 fn = root; 458 459 do { 460 key = (struct rt6key *)((u8 *)fn->leaf + offset); 461 462 /* 463 * Prefix match 464 */ 465 if (plen < fn->fn_bit || 466 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 467 if (!allow_create) { 468 if (replace_required) { 469 pr_warn("Can't replace route, no match found\n"); 470 return ERR_PTR(-ENOENT); 471 } 472 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 473 } 474 goto insert_above; 475 } 476 477 /* 478 * Exact match ? 479 */ 480 481 if (plen == fn->fn_bit) { 482 /* clean up an intermediate node */ 483 if (!(fn->fn_flags & RTN_RTINFO)) { 484 rt6_release(fn->leaf); 485 fn->leaf = NULL; 486 } 487 488 fn->fn_sernum = sernum; 489 490 return fn; 491 } 492 493 /* 494 * We have more bits to go 495 */ 496 497 /* Try to walk down on tree. */ 498 fn->fn_sernum = sernum; 499 dir = addr_bit_set(addr, fn->fn_bit); 500 pn = fn; 501 fn = dir ? fn->right : fn->left; 502 } while (fn); 503 504 if (!allow_create) { 505 /* We should not create new node because 506 * NLM_F_REPLACE was specified without NLM_F_CREATE 507 * I assume it is safe to require NLM_F_CREATE when 508 * REPLACE flag is used! Later we may want to remove the 509 * check for replace_required, because according 510 * to netlink specification, NLM_F_CREATE 511 * MUST be specified if new route is created. 512 * That would keep IPv6 consistent with IPv4 513 */ 514 if (replace_required) { 515 pr_warn("Can't replace route, no match found\n"); 516 return ERR_PTR(-ENOENT); 517 } 518 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 519 } 520 /* 521 * We walked to the bottom of tree. 522 * Create new leaf node without children. 523 */ 524 525 ln = node_alloc(); 526 527 if (!ln) 528 return ERR_PTR(-ENOMEM); 529 ln->fn_bit = plen; 530 531 ln->parent = pn; 532 ln->fn_sernum = sernum; 533 534 if (dir) 535 pn->right = ln; 536 else 537 pn->left = ln; 538 539 return ln; 540 541 542 insert_above: 543 /* 544 * split since we don't have a common prefix anymore or 545 * we have a less significant route. 546 * we've to insert an intermediate node on the list 547 * this new node will point to the one we need to create 548 * and the current 549 */ 550 551 pn = fn->parent; 552 553 /* find 1st bit in difference between the 2 addrs. 554 555 See comment in __ipv6_addr_diff: bit may be an invalid value, 556 but if it is >= plen, the value is ignored in any case. 557 */ 558 559 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 560 561 /* 562 * (intermediate)[in] 563 * / \ 564 * (new leaf node)[ln] (old node)[fn] 565 */ 566 if (plen > bit) { 567 in = node_alloc(); 568 ln = node_alloc(); 569 570 if (!in || !ln) { 571 if (in) 572 node_free(in); 573 if (ln) 574 node_free(ln); 575 return ERR_PTR(-ENOMEM); 576 } 577 578 /* 579 * new intermediate node. 580 * RTN_RTINFO will 581 * be off since that an address that chooses one of 582 * the branches would not match less specific routes 583 * in the other branch 584 */ 585 586 in->fn_bit = bit; 587 588 in->parent = pn; 589 in->leaf = fn->leaf; 590 atomic_inc(&in->leaf->rt6i_ref); 591 592 in->fn_sernum = sernum; 593 594 /* update parent pointer */ 595 if (dir) 596 pn->right = in; 597 else 598 pn->left = in; 599 600 ln->fn_bit = plen; 601 602 ln->parent = in; 603 fn->parent = in; 604 605 ln->fn_sernum = sernum; 606 607 if (addr_bit_set(addr, bit)) { 608 in->right = ln; 609 in->left = fn; 610 } else { 611 in->left = ln; 612 in->right = fn; 613 } 614 } else { /* plen <= bit */ 615 616 /* 617 * (new leaf node)[ln] 618 * / \ 619 * (old node)[fn] NULL 620 */ 621 622 ln = node_alloc(); 623 624 if (!ln) 625 return ERR_PTR(-ENOMEM); 626 627 ln->fn_bit = plen; 628 629 ln->parent = pn; 630 631 ln->fn_sernum = sernum; 632 633 if (dir) 634 pn->right = ln; 635 else 636 pn->left = ln; 637 638 if (addr_bit_set(&key->addr, plen)) 639 ln->right = fn; 640 else 641 ln->left = fn; 642 643 fn->parent = ln; 644 } 645 return ln; 646 } 647 648 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 649 { 650 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 651 RTF_GATEWAY; 652 } 653 654 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 655 { 656 int i; 657 658 for (i = 0; i < RTAX_MAX; i++) { 659 if (test_bit(i, mxc->mx_valid)) 660 mp[i] = mxc->mx[i]; 661 } 662 } 663 664 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 665 { 666 if (!mxc->mx) 667 return 0; 668 669 if (dst->flags & DST_HOST) { 670 u32 *mp = dst_metrics_write_ptr(dst); 671 672 if (unlikely(!mp)) 673 return -ENOMEM; 674 675 fib6_copy_metrics(mp, mxc); 676 } else { 677 dst_init_metrics(dst, mxc->mx, false); 678 679 /* We've stolen mx now. */ 680 mxc->mx = NULL; 681 } 682 683 return 0; 684 } 685 686 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 687 struct net *net) 688 { 689 if (atomic_read(&rt->rt6i_ref) != 1) { 690 /* This route is used as dummy address holder in some split 691 * nodes. It is not leaked, but it still holds other resources, 692 * which must be released in time. So, scan ascendant nodes 693 * and replace dummy references to this route with references 694 * to still alive ones. 695 */ 696 while (fn) { 697 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 698 fn->leaf = fib6_find_prefix(net, fn); 699 atomic_inc(&fn->leaf->rt6i_ref); 700 rt6_release(rt); 701 } 702 fn = fn->parent; 703 } 704 /* No more references are possible at this point. */ 705 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 706 } 707 } 708 709 /* 710 * Insert routing information in a node. 711 */ 712 713 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 714 struct nl_info *info, struct mx6_config *mxc) 715 { 716 struct rt6_info *iter = NULL; 717 struct rt6_info **ins; 718 struct rt6_info **fallback_ins = NULL; 719 int replace = (info->nlh && 720 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 721 int add = (!info->nlh || 722 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 723 int found = 0; 724 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 725 int err; 726 727 ins = &fn->leaf; 728 729 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 730 /* 731 * Search for duplicates 732 */ 733 734 if (iter->rt6i_metric == rt->rt6i_metric) { 735 /* 736 * Same priority level 737 */ 738 if (info->nlh && 739 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 740 return -EEXIST; 741 if (replace) { 742 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 743 found++; 744 break; 745 } 746 if (rt_can_ecmp) 747 fallback_ins = fallback_ins ?: ins; 748 goto next_iter; 749 } 750 751 if (iter->dst.dev == rt->dst.dev && 752 iter->rt6i_idev == rt->rt6i_idev && 753 ipv6_addr_equal(&iter->rt6i_gateway, 754 &rt->rt6i_gateway)) { 755 if (rt->rt6i_nsiblings) 756 rt->rt6i_nsiblings = 0; 757 if (!(iter->rt6i_flags & RTF_EXPIRES)) 758 return -EEXIST; 759 if (!(rt->rt6i_flags & RTF_EXPIRES)) 760 rt6_clean_expires(iter); 761 else 762 rt6_set_expires(iter, rt->dst.expires); 763 iter->rt6i_pmtu = rt->rt6i_pmtu; 764 return -EEXIST; 765 } 766 /* If we have the same destination and the same metric, 767 * but not the same gateway, then the route we try to 768 * add is sibling to this route, increment our counter 769 * of siblings, and later we will add our route to the 770 * list. 771 * Only static routes (which don't have flag 772 * RTF_EXPIRES) are used for ECMPv6. 773 * 774 * To avoid long list, we only had siblings if the 775 * route have a gateway. 776 */ 777 if (rt_can_ecmp && 778 rt6_qualify_for_ecmp(iter)) 779 rt->rt6i_nsiblings++; 780 } 781 782 if (iter->rt6i_metric > rt->rt6i_metric) 783 break; 784 785 next_iter: 786 ins = &iter->dst.rt6_next; 787 } 788 789 if (fallback_ins && !found) { 790 /* No ECMP-able route found, replace first non-ECMP one */ 791 ins = fallback_ins; 792 iter = *ins; 793 found++; 794 } 795 796 /* Reset round-robin state, if necessary */ 797 if (ins == &fn->leaf) 798 fn->rr_ptr = NULL; 799 800 /* Link this route to others same route. */ 801 if (rt->rt6i_nsiblings) { 802 unsigned int rt6i_nsiblings; 803 struct rt6_info *sibling, *temp_sibling; 804 805 /* Find the first route that have the same metric */ 806 sibling = fn->leaf; 807 while (sibling) { 808 if (sibling->rt6i_metric == rt->rt6i_metric && 809 rt6_qualify_for_ecmp(sibling)) { 810 list_add_tail(&rt->rt6i_siblings, 811 &sibling->rt6i_siblings); 812 break; 813 } 814 sibling = sibling->dst.rt6_next; 815 } 816 /* For each sibling in the list, increment the counter of 817 * siblings. BUG() if counters does not match, list of siblings 818 * is broken! 819 */ 820 rt6i_nsiblings = 0; 821 list_for_each_entry_safe(sibling, temp_sibling, 822 &rt->rt6i_siblings, rt6i_siblings) { 823 sibling->rt6i_nsiblings++; 824 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 825 rt6i_nsiblings++; 826 } 827 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 828 } 829 830 /* 831 * insert node 832 */ 833 if (!replace) { 834 if (!add) 835 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 836 837 add: 838 err = fib6_commit_metrics(&rt->dst, mxc); 839 if (err) 840 return err; 841 842 rt->dst.rt6_next = iter; 843 *ins = rt; 844 rt->rt6i_node = fn; 845 atomic_inc(&rt->rt6i_ref); 846 inet6_rt_notify(RTM_NEWROUTE, rt, info); 847 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 848 849 if (!(fn->fn_flags & RTN_RTINFO)) { 850 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 851 fn->fn_flags |= RTN_RTINFO; 852 } 853 854 } else { 855 int nsiblings; 856 857 if (!found) { 858 if (add) 859 goto add; 860 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 861 return -ENOENT; 862 } 863 864 err = fib6_commit_metrics(&rt->dst, mxc); 865 if (err) 866 return err; 867 868 *ins = rt; 869 rt->rt6i_node = fn; 870 rt->dst.rt6_next = iter->dst.rt6_next; 871 atomic_inc(&rt->rt6i_ref); 872 inet6_rt_notify(RTM_NEWROUTE, rt, info); 873 if (!(fn->fn_flags & RTN_RTINFO)) { 874 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 875 fn->fn_flags |= RTN_RTINFO; 876 } 877 nsiblings = iter->rt6i_nsiblings; 878 fib6_purge_rt(iter, fn, info->nl_net); 879 rt6_release(iter); 880 881 if (nsiblings) { 882 /* Replacing an ECMP route, remove all siblings */ 883 ins = &rt->dst.rt6_next; 884 iter = *ins; 885 while (iter) { 886 if (rt6_qualify_for_ecmp(iter)) { 887 *ins = iter->dst.rt6_next; 888 fib6_purge_rt(iter, fn, info->nl_net); 889 rt6_release(iter); 890 nsiblings--; 891 } else { 892 ins = &iter->dst.rt6_next; 893 } 894 iter = *ins; 895 } 896 WARN_ON(nsiblings != 0); 897 } 898 } 899 900 return 0; 901 } 902 903 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 904 { 905 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 906 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 907 mod_timer(&net->ipv6.ip6_fib_timer, 908 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 909 } 910 911 void fib6_force_start_gc(struct net *net) 912 { 913 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 914 mod_timer(&net->ipv6.ip6_fib_timer, 915 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 916 } 917 918 /* 919 * Add routing information to the routing tree. 920 * <destination addr>/<source addr> 921 * with source addr info in sub-trees 922 */ 923 924 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 925 struct nl_info *info, struct mx6_config *mxc) 926 { 927 struct fib6_node *fn, *pn = NULL; 928 int err = -ENOMEM; 929 int allow_create = 1; 930 int replace_required = 0; 931 int sernum = fib6_new_sernum(info->nl_net); 932 933 if (info->nlh) { 934 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 935 allow_create = 0; 936 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 937 replace_required = 1; 938 } 939 if (!allow_create && !replace_required) 940 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 941 942 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 943 offsetof(struct rt6_info, rt6i_dst), allow_create, 944 replace_required, sernum); 945 if (IS_ERR(fn)) { 946 err = PTR_ERR(fn); 947 fn = NULL; 948 goto out; 949 } 950 951 pn = fn; 952 953 #ifdef CONFIG_IPV6_SUBTREES 954 if (rt->rt6i_src.plen) { 955 struct fib6_node *sn; 956 957 if (!fn->subtree) { 958 struct fib6_node *sfn; 959 960 /* 961 * Create subtree. 962 * 963 * fn[main tree] 964 * | 965 * sfn[subtree root] 966 * \ 967 * sn[new leaf node] 968 */ 969 970 /* Create subtree root node */ 971 sfn = node_alloc(); 972 if (!sfn) 973 goto st_failure; 974 975 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 976 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 977 sfn->fn_flags = RTN_ROOT; 978 sfn->fn_sernum = sernum; 979 980 /* Now add the first leaf node to new subtree */ 981 982 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 983 rt->rt6i_src.plen, 984 offsetof(struct rt6_info, rt6i_src), 985 allow_create, replace_required, sernum); 986 987 if (IS_ERR(sn)) { 988 /* If it is failed, discard just allocated 989 root, and then (in st_failure) stale node 990 in main tree. 991 */ 992 node_free(sfn); 993 err = PTR_ERR(sn); 994 goto st_failure; 995 } 996 997 /* Now link new subtree to main tree */ 998 sfn->parent = fn; 999 fn->subtree = sfn; 1000 } else { 1001 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 1002 rt->rt6i_src.plen, 1003 offsetof(struct rt6_info, rt6i_src), 1004 allow_create, replace_required, sernum); 1005 1006 if (IS_ERR(sn)) { 1007 err = PTR_ERR(sn); 1008 goto st_failure; 1009 } 1010 } 1011 1012 if (!fn->leaf) { 1013 fn->leaf = rt; 1014 atomic_inc(&rt->rt6i_ref); 1015 } 1016 fn = sn; 1017 } 1018 #endif 1019 1020 err = fib6_add_rt2node(fn, rt, info, mxc); 1021 if (!err) { 1022 fib6_start_gc(info->nl_net, rt); 1023 if (!(rt->rt6i_flags & RTF_CACHE)) 1024 fib6_prune_clones(info->nl_net, pn); 1025 } 1026 1027 out: 1028 if (err) { 1029 #ifdef CONFIG_IPV6_SUBTREES 1030 /* 1031 * If fib6_add_1 has cleared the old leaf pointer in the 1032 * super-tree leaf node we have to find a new one for it. 1033 */ 1034 if (pn != fn && pn->leaf == rt) { 1035 pn->leaf = NULL; 1036 atomic_dec(&rt->rt6i_ref); 1037 } 1038 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 1039 pn->leaf = fib6_find_prefix(info->nl_net, pn); 1040 #if RT6_DEBUG >= 2 1041 if (!pn->leaf) { 1042 WARN_ON(pn->leaf == NULL); 1043 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 1044 } 1045 #endif 1046 atomic_inc(&pn->leaf->rt6i_ref); 1047 } 1048 #endif 1049 dst_free(&rt->dst); 1050 } 1051 return err; 1052 1053 #ifdef CONFIG_IPV6_SUBTREES 1054 /* Subtree creation failed, probably main tree node 1055 is orphan. If it is, shoot it. 1056 */ 1057 st_failure: 1058 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1059 fib6_repair_tree(info->nl_net, fn); 1060 dst_free(&rt->dst); 1061 return err; 1062 #endif 1063 } 1064 1065 /* 1066 * Routing tree lookup 1067 * 1068 */ 1069 1070 struct lookup_args { 1071 int offset; /* key offset on rt6_info */ 1072 const struct in6_addr *addr; /* search key */ 1073 }; 1074 1075 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1076 struct lookup_args *args) 1077 { 1078 struct fib6_node *fn; 1079 __be32 dir; 1080 1081 if (unlikely(args->offset == 0)) 1082 return NULL; 1083 1084 /* 1085 * Descend on a tree 1086 */ 1087 1088 fn = root; 1089 1090 for (;;) { 1091 struct fib6_node *next; 1092 1093 dir = addr_bit_set(args->addr, fn->fn_bit); 1094 1095 next = dir ? fn->right : fn->left; 1096 1097 if (next) { 1098 fn = next; 1099 continue; 1100 } 1101 break; 1102 } 1103 1104 while (fn) { 1105 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1106 struct rt6key *key; 1107 1108 key = (struct rt6key *) ((u8 *) fn->leaf + 1109 args->offset); 1110 1111 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1112 #ifdef CONFIG_IPV6_SUBTREES 1113 if (fn->subtree) { 1114 struct fib6_node *sfn; 1115 sfn = fib6_lookup_1(fn->subtree, 1116 args + 1); 1117 if (!sfn) 1118 goto backtrack; 1119 fn = sfn; 1120 } 1121 #endif 1122 if (fn->fn_flags & RTN_RTINFO) 1123 return fn; 1124 } 1125 } 1126 #ifdef CONFIG_IPV6_SUBTREES 1127 backtrack: 1128 #endif 1129 if (fn->fn_flags & RTN_ROOT) 1130 break; 1131 1132 fn = fn->parent; 1133 } 1134 1135 return NULL; 1136 } 1137 1138 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1139 const struct in6_addr *saddr) 1140 { 1141 struct fib6_node *fn; 1142 struct lookup_args args[] = { 1143 { 1144 .offset = offsetof(struct rt6_info, rt6i_dst), 1145 .addr = daddr, 1146 }, 1147 #ifdef CONFIG_IPV6_SUBTREES 1148 { 1149 .offset = offsetof(struct rt6_info, rt6i_src), 1150 .addr = saddr, 1151 }, 1152 #endif 1153 { 1154 .offset = 0, /* sentinel */ 1155 } 1156 }; 1157 1158 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1159 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1160 fn = root; 1161 1162 return fn; 1163 } 1164 1165 /* 1166 * Get node with specified destination prefix (and source prefix, 1167 * if subtrees are used) 1168 */ 1169 1170 1171 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1172 const struct in6_addr *addr, 1173 int plen, int offset) 1174 { 1175 struct fib6_node *fn; 1176 1177 for (fn = root; fn ; ) { 1178 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1179 1180 /* 1181 * Prefix match 1182 */ 1183 if (plen < fn->fn_bit || 1184 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1185 return NULL; 1186 1187 if (plen == fn->fn_bit) 1188 return fn; 1189 1190 /* 1191 * We have more bits to go 1192 */ 1193 if (addr_bit_set(addr, fn->fn_bit)) 1194 fn = fn->right; 1195 else 1196 fn = fn->left; 1197 } 1198 return NULL; 1199 } 1200 1201 struct fib6_node *fib6_locate(struct fib6_node *root, 1202 const struct in6_addr *daddr, int dst_len, 1203 const struct in6_addr *saddr, int src_len) 1204 { 1205 struct fib6_node *fn; 1206 1207 fn = fib6_locate_1(root, daddr, dst_len, 1208 offsetof(struct rt6_info, rt6i_dst)); 1209 1210 #ifdef CONFIG_IPV6_SUBTREES 1211 if (src_len) { 1212 WARN_ON(saddr == NULL); 1213 if (fn && fn->subtree) 1214 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1215 offsetof(struct rt6_info, rt6i_src)); 1216 } 1217 #endif 1218 1219 if (fn && fn->fn_flags & RTN_RTINFO) 1220 return fn; 1221 1222 return NULL; 1223 } 1224 1225 1226 /* 1227 * Deletion 1228 * 1229 */ 1230 1231 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1232 { 1233 if (fn->fn_flags & RTN_ROOT) 1234 return net->ipv6.ip6_null_entry; 1235 1236 while (fn) { 1237 if (fn->left) 1238 return fn->left->leaf; 1239 if (fn->right) 1240 return fn->right->leaf; 1241 1242 fn = FIB6_SUBTREE(fn); 1243 } 1244 return NULL; 1245 } 1246 1247 /* 1248 * Called to trim the tree of intermediate nodes when possible. "fn" 1249 * is the node we want to try and remove. 1250 */ 1251 1252 static struct fib6_node *fib6_repair_tree(struct net *net, 1253 struct fib6_node *fn) 1254 { 1255 int children; 1256 int nstate; 1257 struct fib6_node *child, *pn; 1258 struct fib6_walker *w; 1259 int iter = 0; 1260 1261 for (;;) { 1262 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1263 iter++; 1264 1265 WARN_ON(fn->fn_flags & RTN_RTINFO); 1266 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1267 WARN_ON(fn->leaf); 1268 1269 children = 0; 1270 child = NULL; 1271 if (fn->right) 1272 child = fn->right, children |= 1; 1273 if (fn->left) 1274 child = fn->left, children |= 2; 1275 1276 if (children == 3 || FIB6_SUBTREE(fn) 1277 #ifdef CONFIG_IPV6_SUBTREES 1278 /* Subtree root (i.e. fn) may have one child */ 1279 || (children && fn->fn_flags & RTN_ROOT) 1280 #endif 1281 ) { 1282 fn->leaf = fib6_find_prefix(net, fn); 1283 #if RT6_DEBUG >= 2 1284 if (!fn->leaf) { 1285 WARN_ON(!fn->leaf); 1286 fn->leaf = net->ipv6.ip6_null_entry; 1287 } 1288 #endif 1289 atomic_inc(&fn->leaf->rt6i_ref); 1290 return fn->parent; 1291 } 1292 1293 pn = fn->parent; 1294 #ifdef CONFIG_IPV6_SUBTREES 1295 if (FIB6_SUBTREE(pn) == fn) { 1296 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1297 FIB6_SUBTREE(pn) = NULL; 1298 nstate = FWS_L; 1299 } else { 1300 WARN_ON(fn->fn_flags & RTN_ROOT); 1301 #endif 1302 if (pn->right == fn) 1303 pn->right = child; 1304 else if (pn->left == fn) 1305 pn->left = child; 1306 #if RT6_DEBUG >= 2 1307 else 1308 WARN_ON(1); 1309 #endif 1310 if (child) 1311 child->parent = pn; 1312 nstate = FWS_R; 1313 #ifdef CONFIG_IPV6_SUBTREES 1314 } 1315 #endif 1316 1317 read_lock(&fib6_walker_lock); 1318 FOR_WALKERS(w) { 1319 if (!child) { 1320 if (w->root == fn) { 1321 w->root = w->node = NULL; 1322 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1323 } else if (w->node == fn) { 1324 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1325 w->node = pn; 1326 w->state = nstate; 1327 } 1328 } else { 1329 if (w->root == fn) { 1330 w->root = child; 1331 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1332 } 1333 if (w->node == fn) { 1334 w->node = child; 1335 if (children&2) { 1336 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1337 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1338 } else { 1339 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1340 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1341 } 1342 } 1343 } 1344 } 1345 read_unlock(&fib6_walker_lock); 1346 1347 node_free(fn); 1348 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1349 return pn; 1350 1351 rt6_release(pn->leaf); 1352 pn->leaf = NULL; 1353 fn = pn; 1354 } 1355 } 1356 1357 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1358 struct nl_info *info) 1359 { 1360 struct fib6_walker *w; 1361 struct rt6_info *rt = *rtp; 1362 struct net *net = info->nl_net; 1363 1364 RT6_TRACE("fib6_del_route\n"); 1365 1366 /* Unlink it */ 1367 *rtp = rt->dst.rt6_next; 1368 rt->rt6i_node = NULL; 1369 net->ipv6.rt6_stats->fib_rt_entries--; 1370 net->ipv6.rt6_stats->fib_discarded_routes++; 1371 1372 /* Reset round-robin state, if necessary */ 1373 if (fn->rr_ptr == rt) 1374 fn->rr_ptr = NULL; 1375 1376 /* Remove this entry from other siblings */ 1377 if (rt->rt6i_nsiblings) { 1378 struct rt6_info *sibling, *next_sibling; 1379 1380 list_for_each_entry_safe(sibling, next_sibling, 1381 &rt->rt6i_siblings, rt6i_siblings) 1382 sibling->rt6i_nsiblings--; 1383 rt->rt6i_nsiblings = 0; 1384 list_del_init(&rt->rt6i_siblings); 1385 } 1386 1387 /* Adjust walkers */ 1388 read_lock(&fib6_walker_lock); 1389 FOR_WALKERS(w) { 1390 if (w->state == FWS_C && w->leaf == rt) { 1391 RT6_TRACE("walker %p adjusted by delroute\n", w); 1392 w->leaf = rt->dst.rt6_next; 1393 if (!w->leaf) 1394 w->state = FWS_U; 1395 } 1396 } 1397 read_unlock(&fib6_walker_lock); 1398 1399 rt->dst.rt6_next = NULL; 1400 1401 /* If it was last route, expunge its radix tree node */ 1402 if (!fn->leaf) { 1403 fn->fn_flags &= ~RTN_RTINFO; 1404 net->ipv6.rt6_stats->fib_route_nodes--; 1405 fn = fib6_repair_tree(net, fn); 1406 } 1407 1408 fib6_purge_rt(rt, fn, net); 1409 1410 inet6_rt_notify(RTM_DELROUTE, rt, info); 1411 rt6_release(rt); 1412 } 1413 1414 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1415 { 1416 struct net *net = info->nl_net; 1417 struct fib6_node *fn = rt->rt6i_node; 1418 struct rt6_info **rtp; 1419 1420 #if RT6_DEBUG >= 2 1421 if (rt->dst.obsolete > 0) { 1422 WARN_ON(fn); 1423 return -ENOENT; 1424 } 1425 #endif 1426 if (!fn || rt == net->ipv6.ip6_null_entry) 1427 return -ENOENT; 1428 1429 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1430 1431 if (!(rt->rt6i_flags & RTF_CACHE)) { 1432 struct fib6_node *pn = fn; 1433 #ifdef CONFIG_IPV6_SUBTREES 1434 /* clones of this route might be in another subtree */ 1435 if (rt->rt6i_src.plen) { 1436 while (!(pn->fn_flags & RTN_ROOT)) 1437 pn = pn->parent; 1438 pn = pn->parent; 1439 } 1440 #endif 1441 fib6_prune_clones(info->nl_net, pn); 1442 } 1443 1444 /* 1445 * Walk the leaf entries looking for ourself 1446 */ 1447 1448 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1449 if (*rtp == rt) { 1450 fib6_del_route(fn, rtp, info); 1451 return 0; 1452 } 1453 } 1454 return -ENOENT; 1455 } 1456 1457 /* 1458 * Tree traversal function. 1459 * 1460 * Certainly, it is not interrupt safe. 1461 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1462 * It means, that we can modify tree during walking 1463 * and use this function for garbage collection, clone pruning, 1464 * cleaning tree when a device goes down etc. etc. 1465 * 1466 * It guarantees that every node will be traversed, 1467 * and that it will be traversed only once. 1468 * 1469 * Callback function w->func may return: 1470 * 0 -> continue walking. 1471 * positive value -> walking is suspended (used by tree dumps, 1472 * and probably by gc, if it will be split to several slices) 1473 * negative value -> terminate walking. 1474 * 1475 * The function itself returns: 1476 * 0 -> walk is complete. 1477 * >0 -> walk is incomplete (i.e. suspended) 1478 * <0 -> walk is terminated by an error. 1479 */ 1480 1481 static int fib6_walk_continue(struct fib6_walker *w) 1482 { 1483 struct fib6_node *fn, *pn; 1484 1485 for (;;) { 1486 fn = w->node; 1487 if (!fn) 1488 return 0; 1489 1490 if (w->prune && fn != w->root && 1491 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1492 w->state = FWS_C; 1493 w->leaf = fn->leaf; 1494 } 1495 switch (w->state) { 1496 #ifdef CONFIG_IPV6_SUBTREES 1497 case FWS_S: 1498 if (FIB6_SUBTREE(fn)) { 1499 w->node = FIB6_SUBTREE(fn); 1500 continue; 1501 } 1502 w->state = FWS_L; 1503 #endif 1504 case FWS_L: 1505 if (fn->left) { 1506 w->node = fn->left; 1507 w->state = FWS_INIT; 1508 continue; 1509 } 1510 w->state = FWS_R; 1511 case FWS_R: 1512 if (fn->right) { 1513 w->node = fn->right; 1514 w->state = FWS_INIT; 1515 continue; 1516 } 1517 w->state = FWS_C; 1518 w->leaf = fn->leaf; 1519 case FWS_C: 1520 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1521 int err; 1522 1523 if (w->skip) { 1524 w->skip--; 1525 goto skip; 1526 } 1527 1528 err = w->func(w); 1529 if (err) 1530 return err; 1531 1532 w->count++; 1533 continue; 1534 } 1535 skip: 1536 w->state = FWS_U; 1537 case FWS_U: 1538 if (fn == w->root) 1539 return 0; 1540 pn = fn->parent; 1541 w->node = pn; 1542 #ifdef CONFIG_IPV6_SUBTREES 1543 if (FIB6_SUBTREE(pn) == fn) { 1544 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1545 w->state = FWS_L; 1546 continue; 1547 } 1548 #endif 1549 if (pn->left == fn) { 1550 w->state = FWS_R; 1551 continue; 1552 } 1553 if (pn->right == fn) { 1554 w->state = FWS_C; 1555 w->leaf = w->node->leaf; 1556 continue; 1557 } 1558 #if RT6_DEBUG >= 2 1559 WARN_ON(1); 1560 #endif 1561 } 1562 } 1563 } 1564 1565 static int fib6_walk(struct fib6_walker *w) 1566 { 1567 int res; 1568 1569 w->state = FWS_INIT; 1570 w->node = w->root; 1571 1572 fib6_walker_link(w); 1573 res = fib6_walk_continue(w); 1574 if (res <= 0) 1575 fib6_walker_unlink(w); 1576 return res; 1577 } 1578 1579 static int fib6_clean_node(struct fib6_walker *w) 1580 { 1581 int res; 1582 struct rt6_info *rt; 1583 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1584 struct nl_info info = { 1585 .nl_net = c->net, 1586 }; 1587 1588 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1589 w->node->fn_sernum != c->sernum) 1590 w->node->fn_sernum = c->sernum; 1591 1592 if (!c->func) { 1593 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1594 w->leaf = NULL; 1595 return 0; 1596 } 1597 1598 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1599 res = c->func(rt, c->arg); 1600 if (res < 0) { 1601 w->leaf = rt; 1602 res = fib6_del(rt, &info); 1603 if (res) { 1604 #if RT6_DEBUG >= 2 1605 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1606 __func__, rt, rt->rt6i_node, res); 1607 #endif 1608 continue; 1609 } 1610 return 0; 1611 } 1612 WARN_ON(res != 0); 1613 } 1614 w->leaf = rt; 1615 return 0; 1616 } 1617 1618 /* 1619 * Convenient frontend to tree walker. 1620 * 1621 * func is called on each route. 1622 * It may return -1 -> delete this route. 1623 * 0 -> continue walking 1624 * 1625 * prune==1 -> only immediate children of node (certainly, 1626 * ignoring pure split nodes) will be scanned. 1627 */ 1628 1629 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1630 int (*func)(struct rt6_info *, void *arg), 1631 bool prune, int sernum, void *arg) 1632 { 1633 struct fib6_cleaner c; 1634 1635 c.w.root = root; 1636 c.w.func = fib6_clean_node; 1637 c.w.prune = prune; 1638 c.w.count = 0; 1639 c.w.skip = 0; 1640 c.func = func; 1641 c.sernum = sernum; 1642 c.arg = arg; 1643 c.net = net; 1644 1645 fib6_walk(&c.w); 1646 } 1647 1648 static void __fib6_clean_all(struct net *net, 1649 int (*func)(struct rt6_info *, void *), 1650 int sernum, void *arg) 1651 { 1652 struct fib6_table *table; 1653 struct hlist_head *head; 1654 unsigned int h; 1655 1656 rcu_read_lock(); 1657 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1658 head = &net->ipv6.fib_table_hash[h]; 1659 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1660 write_lock_bh(&table->tb6_lock); 1661 fib6_clean_tree(net, &table->tb6_root, 1662 func, false, sernum, arg); 1663 write_unlock_bh(&table->tb6_lock); 1664 } 1665 } 1666 rcu_read_unlock(); 1667 } 1668 1669 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1670 void *arg) 1671 { 1672 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1673 } 1674 1675 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1676 { 1677 if (rt->rt6i_flags & RTF_CACHE) { 1678 RT6_TRACE("pruning clone %p\n", rt); 1679 return -1; 1680 } 1681 1682 return 0; 1683 } 1684 1685 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1686 { 1687 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1688 FIB6_NO_SERNUM_CHANGE, NULL); 1689 } 1690 1691 static void fib6_flush_trees(struct net *net) 1692 { 1693 int new_sernum = fib6_new_sernum(net); 1694 1695 __fib6_clean_all(net, NULL, new_sernum, NULL); 1696 } 1697 1698 /* 1699 * Garbage collection 1700 */ 1701 1702 static struct fib6_gc_args 1703 { 1704 int timeout; 1705 int more; 1706 } gc_args; 1707 1708 static int fib6_age(struct rt6_info *rt, void *arg) 1709 { 1710 unsigned long now = jiffies; 1711 1712 /* 1713 * check addrconf expiration here. 1714 * Routes are expired even if they are in use. 1715 * 1716 * Also age clones. Note, that clones are aged out 1717 * only if they are not in use now. 1718 */ 1719 1720 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1721 if (time_after(now, rt->dst.expires)) { 1722 RT6_TRACE("expiring %p\n", rt); 1723 return -1; 1724 } 1725 gc_args.more++; 1726 } else if (rt->rt6i_flags & RTF_CACHE) { 1727 if (atomic_read(&rt->dst.__refcnt) == 0 && 1728 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1729 RT6_TRACE("aging clone %p\n", rt); 1730 return -1; 1731 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1732 struct neighbour *neigh; 1733 __u8 neigh_flags = 0; 1734 1735 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1736 if (neigh) { 1737 neigh_flags = neigh->flags; 1738 neigh_release(neigh); 1739 } 1740 if (!(neigh_flags & NTF_ROUTER)) { 1741 RT6_TRACE("purging route %p via non-router but gateway\n", 1742 rt); 1743 return -1; 1744 } 1745 } 1746 gc_args.more++; 1747 } 1748 1749 return 0; 1750 } 1751 1752 static DEFINE_SPINLOCK(fib6_gc_lock); 1753 1754 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1755 { 1756 unsigned long now; 1757 1758 if (force) { 1759 spin_lock_bh(&fib6_gc_lock); 1760 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1761 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1762 return; 1763 } 1764 gc_args.timeout = expires ? (int)expires : 1765 net->ipv6.sysctl.ip6_rt_gc_interval; 1766 1767 gc_args.more = icmp6_dst_gc(); 1768 1769 fib6_clean_all(net, fib6_age, NULL); 1770 now = jiffies; 1771 net->ipv6.ip6_rt_last_gc = now; 1772 1773 if (gc_args.more) 1774 mod_timer(&net->ipv6.ip6_fib_timer, 1775 round_jiffies(now 1776 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1777 else 1778 del_timer(&net->ipv6.ip6_fib_timer); 1779 spin_unlock_bh(&fib6_gc_lock); 1780 } 1781 1782 static void fib6_gc_timer_cb(unsigned long arg) 1783 { 1784 fib6_run_gc(0, (struct net *)arg, true); 1785 } 1786 1787 static int __net_init fib6_net_init(struct net *net) 1788 { 1789 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1790 1791 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1792 1793 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1794 if (!net->ipv6.rt6_stats) 1795 goto out_timer; 1796 1797 /* Avoid false sharing : Use at least a full cache line */ 1798 size = max_t(size_t, size, L1_CACHE_BYTES); 1799 1800 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1801 if (!net->ipv6.fib_table_hash) 1802 goto out_rt6_stats; 1803 1804 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1805 GFP_KERNEL); 1806 if (!net->ipv6.fib6_main_tbl) 1807 goto out_fib_table_hash; 1808 1809 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1810 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1811 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1812 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1813 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1814 1815 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1816 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1817 GFP_KERNEL); 1818 if (!net->ipv6.fib6_local_tbl) 1819 goto out_fib6_main_tbl; 1820 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1821 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1822 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1823 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1824 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1825 #endif 1826 fib6_tables_init(net); 1827 1828 return 0; 1829 1830 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1831 out_fib6_main_tbl: 1832 kfree(net->ipv6.fib6_main_tbl); 1833 #endif 1834 out_fib_table_hash: 1835 kfree(net->ipv6.fib_table_hash); 1836 out_rt6_stats: 1837 kfree(net->ipv6.rt6_stats); 1838 out_timer: 1839 return -ENOMEM; 1840 } 1841 1842 static void fib6_net_exit(struct net *net) 1843 { 1844 rt6_ifdown(net, NULL); 1845 del_timer_sync(&net->ipv6.ip6_fib_timer); 1846 1847 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1848 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1849 kfree(net->ipv6.fib6_local_tbl); 1850 #endif 1851 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1852 kfree(net->ipv6.fib6_main_tbl); 1853 kfree(net->ipv6.fib_table_hash); 1854 kfree(net->ipv6.rt6_stats); 1855 } 1856 1857 static struct pernet_operations fib6_net_ops = { 1858 .init = fib6_net_init, 1859 .exit = fib6_net_exit, 1860 }; 1861 1862 int __init fib6_init(void) 1863 { 1864 int ret = -ENOMEM; 1865 1866 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1867 sizeof(struct fib6_node), 1868 0, SLAB_HWCACHE_ALIGN, 1869 NULL); 1870 if (!fib6_node_kmem) 1871 goto out; 1872 1873 ret = register_pernet_subsys(&fib6_net_ops); 1874 if (ret) 1875 goto out_kmem_cache_create; 1876 1877 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1878 NULL); 1879 if (ret) 1880 goto out_unregister_subsys; 1881 1882 __fib6_flush_trees = fib6_flush_trees; 1883 out: 1884 return ret; 1885 1886 out_unregister_subsys: 1887 unregister_pernet_subsys(&fib6_net_ops); 1888 out_kmem_cache_create: 1889 kmem_cache_destroy(fib6_node_kmem); 1890 goto out; 1891 } 1892 1893 void fib6_gc_cleanup(void) 1894 { 1895 unregister_pernet_subsys(&fib6_net_ops); 1896 kmem_cache_destroy(fib6_node_kmem); 1897 } 1898 1899 #ifdef CONFIG_PROC_FS 1900 1901 struct ipv6_route_iter { 1902 struct seq_net_private p; 1903 struct fib6_walker w; 1904 loff_t skip; 1905 struct fib6_table *tbl; 1906 int sernum; 1907 }; 1908 1909 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1910 { 1911 struct rt6_info *rt = v; 1912 struct ipv6_route_iter *iter = seq->private; 1913 1914 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1915 1916 #ifdef CONFIG_IPV6_SUBTREES 1917 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1918 #else 1919 seq_puts(seq, "00000000000000000000000000000000 00 "); 1920 #endif 1921 if (rt->rt6i_flags & RTF_GATEWAY) 1922 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1923 else 1924 seq_puts(seq, "00000000000000000000000000000000"); 1925 1926 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1927 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1928 rt->dst.__use, rt->rt6i_flags, 1929 rt->dst.dev ? rt->dst.dev->name : ""); 1930 iter->w.leaf = NULL; 1931 return 0; 1932 } 1933 1934 static int ipv6_route_yield(struct fib6_walker *w) 1935 { 1936 struct ipv6_route_iter *iter = w->args; 1937 1938 if (!iter->skip) 1939 return 1; 1940 1941 do { 1942 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1943 iter->skip--; 1944 if (!iter->skip && iter->w.leaf) 1945 return 1; 1946 } while (iter->w.leaf); 1947 1948 return 0; 1949 } 1950 1951 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1952 { 1953 memset(&iter->w, 0, sizeof(iter->w)); 1954 iter->w.func = ipv6_route_yield; 1955 iter->w.root = &iter->tbl->tb6_root; 1956 iter->w.state = FWS_INIT; 1957 iter->w.node = iter->w.root; 1958 iter->w.args = iter; 1959 iter->sernum = iter->w.root->fn_sernum; 1960 INIT_LIST_HEAD(&iter->w.lh); 1961 fib6_walker_link(&iter->w); 1962 } 1963 1964 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1965 struct net *net) 1966 { 1967 unsigned int h; 1968 struct hlist_node *node; 1969 1970 if (tbl) { 1971 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1972 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1973 } else { 1974 h = 0; 1975 node = NULL; 1976 } 1977 1978 while (!node && h < FIB6_TABLE_HASHSZ) { 1979 node = rcu_dereference_bh( 1980 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 1981 } 1982 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 1983 } 1984 1985 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 1986 { 1987 if (iter->sernum != iter->w.root->fn_sernum) { 1988 iter->sernum = iter->w.root->fn_sernum; 1989 iter->w.state = FWS_INIT; 1990 iter->w.node = iter->w.root; 1991 WARN_ON(iter->w.skip); 1992 iter->w.skip = iter->w.count; 1993 } 1994 } 1995 1996 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1997 { 1998 int r; 1999 struct rt6_info *n; 2000 struct net *net = seq_file_net(seq); 2001 struct ipv6_route_iter *iter = seq->private; 2002 2003 if (!v) 2004 goto iter_table; 2005 2006 n = ((struct rt6_info *)v)->dst.rt6_next; 2007 if (n) { 2008 ++*pos; 2009 return n; 2010 } 2011 2012 iter_table: 2013 ipv6_route_check_sernum(iter); 2014 read_lock(&iter->tbl->tb6_lock); 2015 r = fib6_walk_continue(&iter->w); 2016 read_unlock(&iter->tbl->tb6_lock); 2017 if (r > 0) { 2018 if (v) 2019 ++*pos; 2020 return iter->w.leaf; 2021 } else if (r < 0) { 2022 fib6_walker_unlink(&iter->w); 2023 return NULL; 2024 } 2025 fib6_walker_unlink(&iter->w); 2026 2027 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2028 if (!iter->tbl) 2029 return NULL; 2030 2031 ipv6_route_seq_setup_walk(iter); 2032 goto iter_table; 2033 } 2034 2035 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2036 __acquires(RCU_BH) 2037 { 2038 struct net *net = seq_file_net(seq); 2039 struct ipv6_route_iter *iter = seq->private; 2040 2041 rcu_read_lock_bh(); 2042 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2043 iter->skip = *pos; 2044 2045 if (iter->tbl) { 2046 ipv6_route_seq_setup_walk(iter); 2047 return ipv6_route_seq_next(seq, NULL, pos); 2048 } else { 2049 return NULL; 2050 } 2051 } 2052 2053 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2054 { 2055 struct fib6_walker *w = &iter->w; 2056 return w->node && !(w->state == FWS_U && w->node == w->root); 2057 } 2058 2059 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2060 __releases(RCU_BH) 2061 { 2062 struct ipv6_route_iter *iter = seq->private; 2063 2064 if (ipv6_route_iter_active(iter)) 2065 fib6_walker_unlink(&iter->w); 2066 2067 rcu_read_unlock_bh(); 2068 } 2069 2070 static const struct seq_operations ipv6_route_seq_ops = { 2071 .start = ipv6_route_seq_start, 2072 .next = ipv6_route_seq_next, 2073 .stop = ipv6_route_seq_stop, 2074 .show = ipv6_route_seq_show 2075 }; 2076 2077 int ipv6_route_open(struct inode *inode, struct file *file) 2078 { 2079 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2080 sizeof(struct ipv6_route_iter)); 2081 } 2082 2083 #endif /* CONFIG_PROC_FS */ 2084