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 #include <net/lwtunnel.h> 36 37 #include <net/ip6_fib.h> 38 #include <net/ip6_route.h> 39 40 #define RT6_DEBUG 2 41 42 #if RT6_DEBUG >= 3 43 #define RT6_TRACE(x...) pr_debug(x) 44 #else 45 #define RT6_TRACE(x...) do { ; } while (0) 46 #endif 47 48 static struct kmem_cache *fib6_node_kmem __read_mostly; 49 50 struct fib6_cleaner { 51 struct fib6_walker w; 52 struct net *net; 53 int (*func)(struct rt6_info *, void *arg); 54 int sernum; 55 void *arg; 56 }; 57 58 static DEFINE_RWLOCK(fib6_walker_lock); 59 60 #ifdef CONFIG_IPV6_SUBTREES 61 #define FWS_INIT FWS_S 62 #else 63 #define FWS_INIT FWS_L 64 #endif 65 66 static void fib6_prune_clones(struct net *net, struct fib6_node *fn); 67 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 68 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 69 static int fib6_walk(struct fib6_walker *w); 70 static int fib6_walk_continue(struct fib6_walker *w); 71 72 /* 73 * A routing update causes an increase of the serial number on the 74 * affected subtree. This allows for cached routes to be asynchronously 75 * tested when modifications are made to the destination cache as a 76 * result of redirects, path MTU changes, etc. 77 */ 78 79 static void fib6_gc_timer_cb(unsigned long arg); 80 81 static LIST_HEAD(fib6_walkers); 82 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh) 83 84 static void fib6_walker_link(struct fib6_walker *w) 85 { 86 write_lock_bh(&fib6_walker_lock); 87 list_add(&w->lh, &fib6_walkers); 88 write_unlock_bh(&fib6_walker_lock); 89 } 90 91 static void fib6_walker_unlink(struct fib6_walker *w) 92 { 93 write_lock_bh(&fib6_walker_lock); 94 list_del(&w->lh); 95 write_unlock_bh(&fib6_walker_lock); 96 } 97 98 static int fib6_new_sernum(struct net *net) 99 { 100 int new, old; 101 102 do { 103 old = atomic_read(&net->ipv6.fib6_sernum); 104 new = old < INT_MAX ? old + 1 : 1; 105 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 106 old, new) != old); 107 return new; 108 } 109 110 enum { 111 FIB6_NO_SERNUM_CHANGE = 0, 112 }; 113 114 /* 115 * Auxiliary address test functions for the radix tree. 116 * 117 * These assume a 32bit processor (although it will work on 118 * 64bit processors) 119 */ 120 121 /* 122 * test bit 123 */ 124 #if defined(__LITTLE_ENDIAN) 125 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 126 #else 127 # define BITOP_BE32_SWIZZLE 0 128 #endif 129 130 static __be32 addr_bit_set(const void *token, int fn_bit) 131 { 132 const __be32 *addr = token; 133 /* 134 * Here, 135 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 136 * is optimized version of 137 * htonl(1 << ((~fn_bit)&0x1F)) 138 * See include/asm-generic/bitops/le.h. 139 */ 140 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 141 addr[fn_bit >> 5]; 142 } 143 144 static struct fib6_node *node_alloc(void) 145 { 146 struct fib6_node *fn; 147 148 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 149 150 return fn; 151 } 152 153 static void node_free(struct fib6_node *fn) 154 { 155 kmem_cache_free(fib6_node_kmem, fn); 156 } 157 158 static void rt6_rcu_free(struct rt6_info *rt) 159 { 160 call_rcu(&rt->dst.rcu_head, dst_rcu_free); 161 } 162 163 static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) 164 { 165 int cpu; 166 167 if (!non_pcpu_rt->rt6i_pcpu) 168 return; 169 170 for_each_possible_cpu(cpu) { 171 struct rt6_info **ppcpu_rt; 172 struct rt6_info *pcpu_rt; 173 174 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 175 pcpu_rt = *ppcpu_rt; 176 if (pcpu_rt) { 177 rt6_rcu_free(pcpu_rt); 178 *ppcpu_rt = NULL; 179 } 180 } 181 182 non_pcpu_rt->rt6i_pcpu = NULL; 183 } 184 185 static void rt6_release(struct rt6_info *rt) 186 { 187 if (atomic_dec_and_test(&rt->rt6i_ref)) { 188 rt6_free_pcpu(rt); 189 rt6_rcu_free(rt); 190 } 191 } 192 193 static void fib6_link_table(struct net *net, struct fib6_table *tb) 194 { 195 unsigned int h; 196 197 /* 198 * Initialize table lock at a single place to give lockdep a key, 199 * tables aren't visible prior to being linked to the list. 200 */ 201 rwlock_init(&tb->tb6_lock); 202 203 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 204 205 /* 206 * No protection necessary, this is the only list mutatation 207 * operation, tables never disappear once they exist. 208 */ 209 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 210 } 211 212 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 213 214 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 215 { 216 struct fib6_table *table; 217 218 table = kzalloc(sizeof(*table), GFP_ATOMIC); 219 if (table) { 220 table->tb6_id = id; 221 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 222 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 223 inet_peer_base_init(&table->tb6_peers); 224 } 225 226 return table; 227 } 228 229 struct fib6_table *fib6_new_table(struct net *net, u32 id) 230 { 231 struct fib6_table *tb; 232 233 if (id == 0) 234 id = RT6_TABLE_MAIN; 235 tb = fib6_get_table(net, id); 236 if (tb) 237 return tb; 238 239 tb = fib6_alloc_table(net, id); 240 if (tb) 241 fib6_link_table(net, tb); 242 243 return tb; 244 } 245 246 struct fib6_table *fib6_get_table(struct net *net, u32 id) 247 { 248 struct fib6_table *tb; 249 struct hlist_head *head; 250 unsigned int h; 251 252 if (id == 0) 253 id = RT6_TABLE_MAIN; 254 h = id & (FIB6_TABLE_HASHSZ - 1); 255 rcu_read_lock(); 256 head = &net->ipv6.fib_table_hash[h]; 257 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 258 if (tb->tb6_id == id) { 259 rcu_read_unlock(); 260 return tb; 261 } 262 } 263 rcu_read_unlock(); 264 265 return NULL; 266 } 267 268 static void __net_init fib6_tables_init(struct net *net) 269 { 270 fib6_link_table(net, net->ipv6.fib6_main_tbl); 271 fib6_link_table(net, net->ipv6.fib6_local_tbl); 272 } 273 #else 274 275 struct fib6_table *fib6_new_table(struct net *net, u32 id) 276 { 277 return fib6_get_table(net, id); 278 } 279 280 struct fib6_table *fib6_get_table(struct net *net, u32 id) 281 { 282 return net->ipv6.fib6_main_tbl; 283 } 284 285 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 286 int flags, pol_lookup_t lookup) 287 { 288 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 289 } 290 291 static void __net_init fib6_tables_init(struct net *net) 292 { 293 fib6_link_table(net, net->ipv6.fib6_main_tbl); 294 } 295 296 #endif 297 298 static int fib6_dump_node(struct fib6_walker *w) 299 { 300 int res; 301 struct rt6_info *rt; 302 303 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 304 res = rt6_dump_route(rt, w->args); 305 if (res < 0) { 306 /* Frame is full, suspend walking */ 307 w->leaf = rt; 308 return 1; 309 } 310 } 311 w->leaf = NULL; 312 return 0; 313 } 314 315 static void fib6_dump_end(struct netlink_callback *cb) 316 { 317 struct fib6_walker *w = (void *)cb->args[2]; 318 319 if (w) { 320 if (cb->args[4]) { 321 cb->args[4] = 0; 322 fib6_walker_unlink(w); 323 } 324 cb->args[2] = 0; 325 kfree(w); 326 } 327 cb->done = (void *)cb->args[3]; 328 cb->args[1] = 3; 329 } 330 331 static int fib6_dump_done(struct netlink_callback *cb) 332 { 333 fib6_dump_end(cb); 334 return cb->done ? cb->done(cb) : 0; 335 } 336 337 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 338 struct netlink_callback *cb) 339 { 340 struct fib6_walker *w; 341 int res; 342 343 w = (void *)cb->args[2]; 344 w->root = &table->tb6_root; 345 346 if (cb->args[4] == 0) { 347 w->count = 0; 348 w->skip = 0; 349 350 read_lock_bh(&table->tb6_lock); 351 res = fib6_walk(w); 352 read_unlock_bh(&table->tb6_lock); 353 if (res > 0) { 354 cb->args[4] = 1; 355 cb->args[5] = w->root->fn_sernum; 356 } 357 } else { 358 if (cb->args[5] != w->root->fn_sernum) { 359 /* Begin at the root if the tree changed */ 360 cb->args[5] = w->root->fn_sernum; 361 w->state = FWS_INIT; 362 w->node = w->root; 363 w->skip = w->count; 364 } else 365 w->skip = 0; 366 367 read_lock_bh(&table->tb6_lock); 368 res = fib6_walk_continue(w); 369 read_unlock_bh(&table->tb6_lock); 370 if (res <= 0) { 371 fib6_walker_unlink(w); 372 cb->args[4] = 0; 373 } 374 } 375 376 return res; 377 } 378 379 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 380 { 381 struct net *net = sock_net(skb->sk); 382 unsigned int h, s_h; 383 unsigned int e = 0, s_e; 384 struct rt6_rtnl_dump_arg arg; 385 struct fib6_walker *w; 386 struct fib6_table *tb; 387 struct hlist_head *head; 388 int res = 0; 389 390 s_h = cb->args[0]; 391 s_e = cb->args[1]; 392 393 w = (void *)cb->args[2]; 394 if (!w) { 395 /* New dump: 396 * 397 * 1. hook callback destructor. 398 */ 399 cb->args[3] = (long)cb->done; 400 cb->done = fib6_dump_done; 401 402 /* 403 * 2. allocate and initialize walker. 404 */ 405 w = kzalloc(sizeof(*w), GFP_ATOMIC); 406 if (!w) 407 return -ENOMEM; 408 w->func = fib6_dump_node; 409 cb->args[2] = (long)w; 410 } 411 412 arg.skb = skb; 413 arg.cb = cb; 414 arg.net = net; 415 w->args = &arg; 416 417 rcu_read_lock(); 418 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 419 e = 0; 420 head = &net->ipv6.fib_table_hash[h]; 421 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 422 if (e < s_e) 423 goto next; 424 res = fib6_dump_table(tb, skb, cb); 425 if (res != 0) 426 goto out; 427 next: 428 e++; 429 } 430 } 431 out: 432 rcu_read_unlock(); 433 cb->args[1] = e; 434 cb->args[0] = h; 435 436 res = res < 0 ? res : skb->len; 437 if (res <= 0) 438 fib6_dump_end(cb); 439 return res; 440 } 441 442 /* 443 * Routing Table 444 * 445 * return the appropriate node for a routing tree "add" operation 446 * by either creating and inserting or by returning an existing 447 * node. 448 */ 449 450 static struct fib6_node *fib6_add_1(struct fib6_node *root, 451 struct in6_addr *addr, int plen, 452 int offset, int allow_create, 453 int replace_required, int sernum) 454 { 455 struct fib6_node *fn, *in, *ln; 456 struct fib6_node *pn = NULL; 457 struct rt6key *key; 458 int bit; 459 __be32 dir = 0; 460 461 RT6_TRACE("fib6_add_1\n"); 462 463 /* insert node in tree */ 464 465 fn = root; 466 467 do { 468 key = (struct rt6key *)((u8 *)fn->leaf + offset); 469 470 /* 471 * Prefix match 472 */ 473 if (plen < fn->fn_bit || 474 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 475 if (!allow_create) { 476 if (replace_required) { 477 pr_warn("Can't replace route, no match found\n"); 478 return ERR_PTR(-ENOENT); 479 } 480 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 481 } 482 goto insert_above; 483 } 484 485 /* 486 * Exact match ? 487 */ 488 489 if (plen == fn->fn_bit) { 490 /* clean up an intermediate node */ 491 if (!(fn->fn_flags & RTN_RTINFO)) { 492 rt6_release(fn->leaf); 493 fn->leaf = NULL; 494 } 495 496 fn->fn_sernum = sernum; 497 498 return fn; 499 } 500 501 /* 502 * We have more bits to go 503 */ 504 505 /* Try to walk down on tree. */ 506 fn->fn_sernum = sernum; 507 dir = addr_bit_set(addr, fn->fn_bit); 508 pn = fn; 509 fn = dir ? fn->right : fn->left; 510 } while (fn); 511 512 if (!allow_create) { 513 /* We should not create new node because 514 * NLM_F_REPLACE was specified without NLM_F_CREATE 515 * I assume it is safe to require NLM_F_CREATE when 516 * REPLACE flag is used! Later we may want to remove the 517 * check for replace_required, because according 518 * to netlink specification, NLM_F_CREATE 519 * MUST be specified if new route is created. 520 * That would keep IPv6 consistent with IPv4 521 */ 522 if (replace_required) { 523 pr_warn("Can't replace route, no match found\n"); 524 return ERR_PTR(-ENOENT); 525 } 526 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 527 } 528 /* 529 * We walked to the bottom of tree. 530 * Create new leaf node without children. 531 */ 532 533 ln = node_alloc(); 534 535 if (!ln) 536 return ERR_PTR(-ENOMEM); 537 ln->fn_bit = plen; 538 539 ln->parent = pn; 540 ln->fn_sernum = sernum; 541 542 if (dir) 543 pn->right = ln; 544 else 545 pn->left = ln; 546 547 return ln; 548 549 550 insert_above: 551 /* 552 * split since we don't have a common prefix anymore or 553 * we have a less significant route. 554 * we've to insert an intermediate node on the list 555 * this new node will point to the one we need to create 556 * and the current 557 */ 558 559 pn = fn->parent; 560 561 /* find 1st bit in difference between the 2 addrs. 562 563 See comment in __ipv6_addr_diff: bit may be an invalid value, 564 but if it is >= plen, the value is ignored in any case. 565 */ 566 567 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 568 569 /* 570 * (intermediate)[in] 571 * / \ 572 * (new leaf node)[ln] (old node)[fn] 573 */ 574 if (plen > bit) { 575 in = node_alloc(); 576 ln = node_alloc(); 577 578 if (!in || !ln) { 579 if (in) 580 node_free(in); 581 if (ln) 582 node_free(ln); 583 return ERR_PTR(-ENOMEM); 584 } 585 586 /* 587 * new intermediate node. 588 * RTN_RTINFO will 589 * be off since that an address that chooses one of 590 * the branches would not match less specific routes 591 * in the other branch 592 */ 593 594 in->fn_bit = bit; 595 596 in->parent = pn; 597 in->leaf = fn->leaf; 598 atomic_inc(&in->leaf->rt6i_ref); 599 600 in->fn_sernum = sernum; 601 602 /* update parent pointer */ 603 if (dir) 604 pn->right = in; 605 else 606 pn->left = in; 607 608 ln->fn_bit = plen; 609 610 ln->parent = in; 611 fn->parent = in; 612 613 ln->fn_sernum = sernum; 614 615 if (addr_bit_set(addr, bit)) { 616 in->right = ln; 617 in->left = fn; 618 } else { 619 in->left = ln; 620 in->right = fn; 621 } 622 } else { /* plen <= bit */ 623 624 /* 625 * (new leaf node)[ln] 626 * / \ 627 * (old node)[fn] NULL 628 */ 629 630 ln = node_alloc(); 631 632 if (!ln) 633 return ERR_PTR(-ENOMEM); 634 635 ln->fn_bit = plen; 636 637 ln->parent = pn; 638 639 ln->fn_sernum = sernum; 640 641 if (dir) 642 pn->right = ln; 643 else 644 pn->left = ln; 645 646 if (addr_bit_set(&key->addr, plen)) 647 ln->right = fn; 648 else 649 ln->left = fn; 650 651 fn->parent = ln; 652 } 653 return ln; 654 } 655 656 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 657 { 658 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 659 RTF_GATEWAY; 660 } 661 662 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 663 { 664 int i; 665 666 for (i = 0; i < RTAX_MAX; i++) { 667 if (test_bit(i, mxc->mx_valid)) 668 mp[i] = mxc->mx[i]; 669 } 670 } 671 672 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 673 { 674 if (!mxc->mx) 675 return 0; 676 677 if (dst->flags & DST_HOST) { 678 u32 *mp = dst_metrics_write_ptr(dst); 679 680 if (unlikely(!mp)) 681 return -ENOMEM; 682 683 fib6_copy_metrics(mp, mxc); 684 } else { 685 dst_init_metrics(dst, mxc->mx, false); 686 687 /* We've stolen mx now. */ 688 mxc->mx = NULL; 689 } 690 691 return 0; 692 } 693 694 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 695 struct net *net) 696 { 697 if (atomic_read(&rt->rt6i_ref) != 1) { 698 /* This route is used as dummy address holder in some split 699 * nodes. It is not leaked, but it still holds other resources, 700 * which must be released in time. So, scan ascendant nodes 701 * and replace dummy references to this route with references 702 * to still alive ones. 703 */ 704 while (fn) { 705 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 706 fn->leaf = fib6_find_prefix(net, fn); 707 atomic_inc(&fn->leaf->rt6i_ref); 708 rt6_release(rt); 709 } 710 fn = fn->parent; 711 } 712 /* No more references are possible at this point. */ 713 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 714 } 715 } 716 717 /* 718 * Insert routing information in a node. 719 */ 720 721 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 722 struct nl_info *info, struct mx6_config *mxc) 723 { 724 struct rt6_info *iter = NULL; 725 struct rt6_info **ins; 726 struct rt6_info **fallback_ins = NULL; 727 int replace = (info->nlh && 728 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 729 int add = (!info->nlh || 730 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 731 int found = 0; 732 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 733 int err; 734 735 ins = &fn->leaf; 736 737 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 738 /* 739 * Search for duplicates 740 */ 741 742 if (iter->rt6i_metric == rt->rt6i_metric) { 743 /* 744 * Same priority level 745 */ 746 if (info->nlh && 747 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 748 return -EEXIST; 749 if (replace) { 750 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 751 found++; 752 break; 753 } 754 if (rt_can_ecmp) 755 fallback_ins = fallback_ins ?: ins; 756 goto next_iter; 757 } 758 759 if (iter->dst.dev == rt->dst.dev && 760 iter->rt6i_idev == rt->rt6i_idev && 761 ipv6_addr_equal(&iter->rt6i_gateway, 762 &rt->rt6i_gateway)) { 763 if (rt->rt6i_nsiblings) 764 rt->rt6i_nsiblings = 0; 765 if (!(iter->rt6i_flags & RTF_EXPIRES)) 766 return -EEXIST; 767 if (!(rt->rt6i_flags & RTF_EXPIRES)) 768 rt6_clean_expires(iter); 769 else 770 rt6_set_expires(iter, rt->dst.expires); 771 iter->rt6i_pmtu = rt->rt6i_pmtu; 772 return -EEXIST; 773 } 774 /* If we have the same destination and the same metric, 775 * but not the same gateway, then the route we try to 776 * add is sibling to this route, increment our counter 777 * of siblings, and later we will add our route to the 778 * list. 779 * Only static routes (which don't have flag 780 * RTF_EXPIRES) are used for ECMPv6. 781 * 782 * To avoid long list, we only had siblings if the 783 * route have a gateway. 784 */ 785 if (rt_can_ecmp && 786 rt6_qualify_for_ecmp(iter)) 787 rt->rt6i_nsiblings++; 788 } 789 790 if (iter->rt6i_metric > rt->rt6i_metric) 791 break; 792 793 next_iter: 794 ins = &iter->dst.rt6_next; 795 } 796 797 if (fallback_ins && !found) { 798 /* No ECMP-able route found, replace first non-ECMP one */ 799 ins = fallback_ins; 800 iter = *ins; 801 found++; 802 } 803 804 /* Reset round-robin state, if necessary */ 805 if (ins == &fn->leaf) 806 fn->rr_ptr = NULL; 807 808 /* Link this route to others same route. */ 809 if (rt->rt6i_nsiblings) { 810 unsigned int rt6i_nsiblings; 811 struct rt6_info *sibling, *temp_sibling; 812 813 /* Find the first route that have the same metric */ 814 sibling = fn->leaf; 815 while (sibling) { 816 if (sibling->rt6i_metric == rt->rt6i_metric && 817 rt6_qualify_for_ecmp(sibling)) { 818 list_add_tail(&rt->rt6i_siblings, 819 &sibling->rt6i_siblings); 820 break; 821 } 822 sibling = sibling->dst.rt6_next; 823 } 824 /* For each sibling in the list, increment the counter of 825 * siblings. BUG() if counters does not match, list of siblings 826 * is broken! 827 */ 828 rt6i_nsiblings = 0; 829 list_for_each_entry_safe(sibling, temp_sibling, 830 &rt->rt6i_siblings, rt6i_siblings) { 831 sibling->rt6i_nsiblings++; 832 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 833 rt6i_nsiblings++; 834 } 835 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 836 } 837 838 /* 839 * insert node 840 */ 841 if (!replace) { 842 if (!add) 843 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 844 845 add: 846 err = fib6_commit_metrics(&rt->dst, mxc); 847 if (err) 848 return err; 849 850 rt->dst.rt6_next = iter; 851 *ins = rt; 852 rt->rt6i_node = fn; 853 atomic_inc(&rt->rt6i_ref); 854 inet6_rt_notify(RTM_NEWROUTE, rt, info, 0); 855 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 856 857 if (!(fn->fn_flags & RTN_RTINFO)) { 858 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 859 fn->fn_flags |= RTN_RTINFO; 860 } 861 862 } else { 863 int nsiblings; 864 865 if (!found) { 866 if (add) 867 goto add; 868 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 869 return -ENOENT; 870 } 871 872 err = fib6_commit_metrics(&rt->dst, mxc); 873 if (err) 874 return err; 875 876 *ins = rt; 877 rt->rt6i_node = fn; 878 rt->dst.rt6_next = iter->dst.rt6_next; 879 atomic_inc(&rt->rt6i_ref); 880 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 881 if (!(fn->fn_flags & RTN_RTINFO)) { 882 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 883 fn->fn_flags |= RTN_RTINFO; 884 } 885 nsiblings = iter->rt6i_nsiblings; 886 fib6_purge_rt(iter, fn, info->nl_net); 887 rt6_release(iter); 888 889 if (nsiblings) { 890 /* Replacing an ECMP route, remove all siblings */ 891 ins = &rt->dst.rt6_next; 892 iter = *ins; 893 while (iter) { 894 if (rt6_qualify_for_ecmp(iter)) { 895 *ins = iter->dst.rt6_next; 896 fib6_purge_rt(iter, fn, info->nl_net); 897 rt6_release(iter); 898 nsiblings--; 899 } else { 900 ins = &iter->dst.rt6_next; 901 } 902 iter = *ins; 903 } 904 WARN_ON(nsiblings != 0); 905 } 906 } 907 908 return 0; 909 } 910 911 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 912 { 913 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 914 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 915 mod_timer(&net->ipv6.ip6_fib_timer, 916 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 917 } 918 919 void fib6_force_start_gc(struct net *net) 920 { 921 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 922 mod_timer(&net->ipv6.ip6_fib_timer, 923 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 924 } 925 926 /* 927 * Add routing information to the routing tree. 928 * <destination addr>/<source addr> 929 * with source addr info in sub-trees 930 */ 931 932 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 933 struct nl_info *info, struct mx6_config *mxc) 934 { 935 struct fib6_node *fn, *pn = NULL; 936 int err = -ENOMEM; 937 int allow_create = 1; 938 int replace_required = 0; 939 int sernum = fib6_new_sernum(info->nl_net); 940 941 if (WARN_ON_ONCE((rt->dst.flags & DST_NOCACHE) && 942 !atomic_read(&rt->dst.__refcnt))) 943 return -EINVAL; 944 945 if (info->nlh) { 946 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 947 allow_create = 0; 948 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 949 replace_required = 1; 950 } 951 if (!allow_create && !replace_required) 952 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 953 954 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 955 offsetof(struct rt6_info, rt6i_dst), allow_create, 956 replace_required, sernum); 957 if (IS_ERR(fn)) { 958 err = PTR_ERR(fn); 959 fn = NULL; 960 goto out; 961 } 962 963 pn = fn; 964 965 #ifdef CONFIG_IPV6_SUBTREES 966 if (rt->rt6i_src.plen) { 967 struct fib6_node *sn; 968 969 if (!fn->subtree) { 970 struct fib6_node *sfn; 971 972 /* 973 * Create subtree. 974 * 975 * fn[main tree] 976 * | 977 * sfn[subtree root] 978 * \ 979 * sn[new leaf node] 980 */ 981 982 /* Create subtree root node */ 983 sfn = node_alloc(); 984 if (!sfn) 985 goto st_failure; 986 987 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 988 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 989 sfn->fn_flags = RTN_ROOT; 990 sfn->fn_sernum = sernum; 991 992 /* Now add the first leaf node to new subtree */ 993 994 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 995 rt->rt6i_src.plen, 996 offsetof(struct rt6_info, rt6i_src), 997 allow_create, replace_required, sernum); 998 999 if (IS_ERR(sn)) { 1000 /* If it is failed, discard just allocated 1001 root, and then (in st_failure) stale node 1002 in main tree. 1003 */ 1004 node_free(sfn); 1005 err = PTR_ERR(sn); 1006 goto st_failure; 1007 } 1008 1009 /* Now link new subtree to main tree */ 1010 sfn->parent = fn; 1011 fn->subtree = sfn; 1012 } else { 1013 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 1014 rt->rt6i_src.plen, 1015 offsetof(struct rt6_info, rt6i_src), 1016 allow_create, replace_required, sernum); 1017 1018 if (IS_ERR(sn)) { 1019 err = PTR_ERR(sn); 1020 goto st_failure; 1021 } 1022 } 1023 1024 if (!fn->leaf) { 1025 fn->leaf = rt; 1026 atomic_inc(&rt->rt6i_ref); 1027 } 1028 fn = sn; 1029 } 1030 #endif 1031 1032 err = fib6_add_rt2node(fn, rt, info, mxc); 1033 if (!err) { 1034 fib6_start_gc(info->nl_net, rt); 1035 if (!(rt->rt6i_flags & RTF_CACHE)) 1036 fib6_prune_clones(info->nl_net, pn); 1037 rt->dst.flags &= ~DST_NOCACHE; 1038 } 1039 1040 out: 1041 if (err) { 1042 #ifdef CONFIG_IPV6_SUBTREES 1043 /* 1044 * If fib6_add_1 has cleared the old leaf pointer in the 1045 * super-tree leaf node we have to find a new one for it. 1046 */ 1047 if (pn != fn && pn->leaf == rt) { 1048 pn->leaf = NULL; 1049 atomic_dec(&rt->rt6i_ref); 1050 } 1051 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 1052 pn->leaf = fib6_find_prefix(info->nl_net, pn); 1053 #if RT6_DEBUG >= 2 1054 if (!pn->leaf) { 1055 WARN_ON(pn->leaf == NULL); 1056 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 1057 } 1058 #endif 1059 atomic_inc(&pn->leaf->rt6i_ref); 1060 } 1061 #endif 1062 if (!(rt->dst.flags & DST_NOCACHE)) 1063 dst_free(&rt->dst); 1064 } 1065 return err; 1066 1067 #ifdef CONFIG_IPV6_SUBTREES 1068 /* Subtree creation failed, probably main tree node 1069 is orphan. If it is, shoot it. 1070 */ 1071 st_failure: 1072 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1073 fib6_repair_tree(info->nl_net, fn); 1074 if (!(rt->dst.flags & DST_NOCACHE)) 1075 dst_free(&rt->dst); 1076 return err; 1077 #endif 1078 } 1079 1080 /* 1081 * Routing tree lookup 1082 * 1083 */ 1084 1085 struct lookup_args { 1086 int offset; /* key offset on rt6_info */ 1087 const struct in6_addr *addr; /* search key */ 1088 }; 1089 1090 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1091 struct lookup_args *args) 1092 { 1093 struct fib6_node *fn; 1094 __be32 dir; 1095 1096 if (unlikely(args->offset == 0)) 1097 return NULL; 1098 1099 /* 1100 * Descend on a tree 1101 */ 1102 1103 fn = root; 1104 1105 for (;;) { 1106 struct fib6_node *next; 1107 1108 dir = addr_bit_set(args->addr, fn->fn_bit); 1109 1110 next = dir ? fn->right : fn->left; 1111 1112 if (next) { 1113 fn = next; 1114 continue; 1115 } 1116 break; 1117 } 1118 1119 while (fn) { 1120 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1121 struct rt6key *key; 1122 1123 key = (struct rt6key *) ((u8 *) fn->leaf + 1124 args->offset); 1125 1126 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1127 #ifdef CONFIG_IPV6_SUBTREES 1128 if (fn->subtree) { 1129 struct fib6_node *sfn; 1130 sfn = fib6_lookup_1(fn->subtree, 1131 args + 1); 1132 if (!sfn) 1133 goto backtrack; 1134 fn = sfn; 1135 } 1136 #endif 1137 if (fn->fn_flags & RTN_RTINFO) 1138 return fn; 1139 } 1140 } 1141 #ifdef CONFIG_IPV6_SUBTREES 1142 backtrack: 1143 #endif 1144 if (fn->fn_flags & RTN_ROOT) 1145 break; 1146 1147 fn = fn->parent; 1148 } 1149 1150 return NULL; 1151 } 1152 1153 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1154 const struct in6_addr *saddr) 1155 { 1156 struct fib6_node *fn; 1157 struct lookup_args args[] = { 1158 { 1159 .offset = offsetof(struct rt6_info, rt6i_dst), 1160 .addr = daddr, 1161 }, 1162 #ifdef CONFIG_IPV6_SUBTREES 1163 { 1164 .offset = offsetof(struct rt6_info, rt6i_src), 1165 .addr = saddr, 1166 }, 1167 #endif 1168 { 1169 .offset = 0, /* sentinel */ 1170 } 1171 }; 1172 1173 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1174 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1175 fn = root; 1176 1177 return fn; 1178 } 1179 1180 /* 1181 * Get node with specified destination prefix (and source prefix, 1182 * if subtrees are used) 1183 */ 1184 1185 1186 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1187 const struct in6_addr *addr, 1188 int plen, int offset) 1189 { 1190 struct fib6_node *fn; 1191 1192 for (fn = root; fn ; ) { 1193 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1194 1195 /* 1196 * Prefix match 1197 */ 1198 if (plen < fn->fn_bit || 1199 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1200 return NULL; 1201 1202 if (plen == fn->fn_bit) 1203 return fn; 1204 1205 /* 1206 * We have more bits to go 1207 */ 1208 if (addr_bit_set(addr, fn->fn_bit)) 1209 fn = fn->right; 1210 else 1211 fn = fn->left; 1212 } 1213 return NULL; 1214 } 1215 1216 struct fib6_node *fib6_locate(struct fib6_node *root, 1217 const struct in6_addr *daddr, int dst_len, 1218 const struct in6_addr *saddr, int src_len) 1219 { 1220 struct fib6_node *fn; 1221 1222 fn = fib6_locate_1(root, daddr, dst_len, 1223 offsetof(struct rt6_info, rt6i_dst)); 1224 1225 #ifdef CONFIG_IPV6_SUBTREES 1226 if (src_len) { 1227 WARN_ON(saddr == NULL); 1228 if (fn && fn->subtree) 1229 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1230 offsetof(struct rt6_info, rt6i_src)); 1231 } 1232 #endif 1233 1234 if (fn && fn->fn_flags & RTN_RTINFO) 1235 return fn; 1236 1237 return NULL; 1238 } 1239 1240 1241 /* 1242 * Deletion 1243 * 1244 */ 1245 1246 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1247 { 1248 if (fn->fn_flags & RTN_ROOT) 1249 return net->ipv6.ip6_null_entry; 1250 1251 while (fn) { 1252 if (fn->left) 1253 return fn->left->leaf; 1254 if (fn->right) 1255 return fn->right->leaf; 1256 1257 fn = FIB6_SUBTREE(fn); 1258 } 1259 return NULL; 1260 } 1261 1262 /* 1263 * Called to trim the tree of intermediate nodes when possible. "fn" 1264 * is the node we want to try and remove. 1265 */ 1266 1267 static struct fib6_node *fib6_repair_tree(struct net *net, 1268 struct fib6_node *fn) 1269 { 1270 int children; 1271 int nstate; 1272 struct fib6_node *child, *pn; 1273 struct fib6_walker *w; 1274 int iter = 0; 1275 1276 for (;;) { 1277 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1278 iter++; 1279 1280 WARN_ON(fn->fn_flags & RTN_RTINFO); 1281 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1282 WARN_ON(fn->leaf); 1283 1284 children = 0; 1285 child = NULL; 1286 if (fn->right) 1287 child = fn->right, children |= 1; 1288 if (fn->left) 1289 child = fn->left, children |= 2; 1290 1291 if (children == 3 || FIB6_SUBTREE(fn) 1292 #ifdef CONFIG_IPV6_SUBTREES 1293 /* Subtree root (i.e. fn) may have one child */ 1294 || (children && fn->fn_flags & RTN_ROOT) 1295 #endif 1296 ) { 1297 fn->leaf = fib6_find_prefix(net, fn); 1298 #if RT6_DEBUG >= 2 1299 if (!fn->leaf) { 1300 WARN_ON(!fn->leaf); 1301 fn->leaf = net->ipv6.ip6_null_entry; 1302 } 1303 #endif 1304 atomic_inc(&fn->leaf->rt6i_ref); 1305 return fn->parent; 1306 } 1307 1308 pn = fn->parent; 1309 #ifdef CONFIG_IPV6_SUBTREES 1310 if (FIB6_SUBTREE(pn) == fn) { 1311 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1312 FIB6_SUBTREE(pn) = NULL; 1313 nstate = FWS_L; 1314 } else { 1315 WARN_ON(fn->fn_flags & RTN_ROOT); 1316 #endif 1317 if (pn->right == fn) 1318 pn->right = child; 1319 else if (pn->left == fn) 1320 pn->left = child; 1321 #if RT6_DEBUG >= 2 1322 else 1323 WARN_ON(1); 1324 #endif 1325 if (child) 1326 child->parent = pn; 1327 nstate = FWS_R; 1328 #ifdef CONFIG_IPV6_SUBTREES 1329 } 1330 #endif 1331 1332 read_lock(&fib6_walker_lock); 1333 FOR_WALKERS(w) { 1334 if (!child) { 1335 if (w->root == fn) { 1336 w->root = w->node = NULL; 1337 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1338 } else if (w->node == fn) { 1339 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1340 w->node = pn; 1341 w->state = nstate; 1342 } 1343 } else { 1344 if (w->root == fn) { 1345 w->root = child; 1346 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1347 } 1348 if (w->node == fn) { 1349 w->node = child; 1350 if (children&2) { 1351 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1352 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1353 } else { 1354 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1355 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1356 } 1357 } 1358 } 1359 } 1360 read_unlock(&fib6_walker_lock); 1361 1362 node_free(fn); 1363 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1364 return pn; 1365 1366 rt6_release(pn->leaf); 1367 pn->leaf = NULL; 1368 fn = pn; 1369 } 1370 } 1371 1372 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1373 struct nl_info *info) 1374 { 1375 struct fib6_walker *w; 1376 struct rt6_info *rt = *rtp; 1377 struct net *net = info->nl_net; 1378 1379 RT6_TRACE("fib6_del_route\n"); 1380 1381 /* Unlink it */ 1382 *rtp = rt->dst.rt6_next; 1383 rt->rt6i_node = NULL; 1384 net->ipv6.rt6_stats->fib_rt_entries--; 1385 net->ipv6.rt6_stats->fib_discarded_routes++; 1386 1387 /* Reset round-robin state, if necessary */ 1388 if (fn->rr_ptr == rt) 1389 fn->rr_ptr = NULL; 1390 1391 /* Remove this entry from other siblings */ 1392 if (rt->rt6i_nsiblings) { 1393 struct rt6_info *sibling, *next_sibling; 1394 1395 list_for_each_entry_safe(sibling, next_sibling, 1396 &rt->rt6i_siblings, rt6i_siblings) 1397 sibling->rt6i_nsiblings--; 1398 rt->rt6i_nsiblings = 0; 1399 list_del_init(&rt->rt6i_siblings); 1400 } 1401 1402 /* Adjust walkers */ 1403 read_lock(&fib6_walker_lock); 1404 FOR_WALKERS(w) { 1405 if (w->state == FWS_C && w->leaf == rt) { 1406 RT6_TRACE("walker %p adjusted by delroute\n", w); 1407 w->leaf = rt->dst.rt6_next; 1408 if (!w->leaf) 1409 w->state = FWS_U; 1410 } 1411 } 1412 read_unlock(&fib6_walker_lock); 1413 1414 rt->dst.rt6_next = NULL; 1415 1416 /* If it was last route, expunge its radix tree node */ 1417 if (!fn->leaf) { 1418 fn->fn_flags &= ~RTN_RTINFO; 1419 net->ipv6.rt6_stats->fib_route_nodes--; 1420 fn = fib6_repair_tree(net, fn); 1421 } 1422 1423 fib6_purge_rt(rt, fn, net); 1424 1425 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1426 rt6_release(rt); 1427 } 1428 1429 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1430 { 1431 struct net *net = info->nl_net; 1432 struct fib6_node *fn = rt->rt6i_node; 1433 struct rt6_info **rtp; 1434 1435 #if RT6_DEBUG >= 2 1436 if (rt->dst.obsolete > 0) { 1437 WARN_ON(fn); 1438 return -ENOENT; 1439 } 1440 #endif 1441 if (!fn || rt == net->ipv6.ip6_null_entry) 1442 return -ENOENT; 1443 1444 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1445 1446 if (!(rt->rt6i_flags & RTF_CACHE)) { 1447 struct fib6_node *pn = fn; 1448 #ifdef CONFIG_IPV6_SUBTREES 1449 /* clones of this route might be in another subtree */ 1450 if (rt->rt6i_src.plen) { 1451 while (!(pn->fn_flags & RTN_ROOT)) 1452 pn = pn->parent; 1453 pn = pn->parent; 1454 } 1455 #endif 1456 fib6_prune_clones(info->nl_net, pn); 1457 } 1458 1459 /* 1460 * Walk the leaf entries looking for ourself 1461 */ 1462 1463 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1464 if (*rtp == rt) { 1465 fib6_del_route(fn, rtp, info); 1466 return 0; 1467 } 1468 } 1469 return -ENOENT; 1470 } 1471 1472 /* 1473 * Tree traversal function. 1474 * 1475 * Certainly, it is not interrupt safe. 1476 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1477 * It means, that we can modify tree during walking 1478 * and use this function for garbage collection, clone pruning, 1479 * cleaning tree when a device goes down etc. etc. 1480 * 1481 * It guarantees that every node will be traversed, 1482 * and that it will be traversed only once. 1483 * 1484 * Callback function w->func may return: 1485 * 0 -> continue walking. 1486 * positive value -> walking is suspended (used by tree dumps, 1487 * and probably by gc, if it will be split to several slices) 1488 * negative value -> terminate walking. 1489 * 1490 * The function itself returns: 1491 * 0 -> walk is complete. 1492 * >0 -> walk is incomplete (i.e. suspended) 1493 * <0 -> walk is terminated by an error. 1494 */ 1495 1496 static int fib6_walk_continue(struct fib6_walker *w) 1497 { 1498 struct fib6_node *fn, *pn; 1499 1500 for (;;) { 1501 fn = w->node; 1502 if (!fn) 1503 return 0; 1504 1505 if (w->prune && fn != w->root && 1506 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1507 w->state = FWS_C; 1508 w->leaf = fn->leaf; 1509 } 1510 switch (w->state) { 1511 #ifdef CONFIG_IPV6_SUBTREES 1512 case FWS_S: 1513 if (FIB6_SUBTREE(fn)) { 1514 w->node = FIB6_SUBTREE(fn); 1515 continue; 1516 } 1517 w->state = FWS_L; 1518 #endif 1519 case FWS_L: 1520 if (fn->left) { 1521 w->node = fn->left; 1522 w->state = FWS_INIT; 1523 continue; 1524 } 1525 w->state = FWS_R; 1526 case FWS_R: 1527 if (fn->right) { 1528 w->node = fn->right; 1529 w->state = FWS_INIT; 1530 continue; 1531 } 1532 w->state = FWS_C; 1533 w->leaf = fn->leaf; 1534 case FWS_C: 1535 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1536 int err; 1537 1538 if (w->skip) { 1539 w->skip--; 1540 goto skip; 1541 } 1542 1543 err = w->func(w); 1544 if (err) 1545 return err; 1546 1547 w->count++; 1548 continue; 1549 } 1550 skip: 1551 w->state = FWS_U; 1552 case FWS_U: 1553 if (fn == w->root) 1554 return 0; 1555 pn = fn->parent; 1556 w->node = pn; 1557 #ifdef CONFIG_IPV6_SUBTREES 1558 if (FIB6_SUBTREE(pn) == fn) { 1559 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1560 w->state = FWS_L; 1561 continue; 1562 } 1563 #endif 1564 if (pn->left == fn) { 1565 w->state = FWS_R; 1566 continue; 1567 } 1568 if (pn->right == fn) { 1569 w->state = FWS_C; 1570 w->leaf = w->node->leaf; 1571 continue; 1572 } 1573 #if RT6_DEBUG >= 2 1574 WARN_ON(1); 1575 #endif 1576 } 1577 } 1578 } 1579 1580 static int fib6_walk(struct fib6_walker *w) 1581 { 1582 int res; 1583 1584 w->state = FWS_INIT; 1585 w->node = w->root; 1586 1587 fib6_walker_link(w); 1588 res = fib6_walk_continue(w); 1589 if (res <= 0) 1590 fib6_walker_unlink(w); 1591 return res; 1592 } 1593 1594 static int fib6_clean_node(struct fib6_walker *w) 1595 { 1596 int res; 1597 struct rt6_info *rt; 1598 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1599 struct nl_info info = { 1600 .nl_net = c->net, 1601 }; 1602 1603 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1604 w->node->fn_sernum != c->sernum) 1605 w->node->fn_sernum = c->sernum; 1606 1607 if (!c->func) { 1608 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1609 w->leaf = NULL; 1610 return 0; 1611 } 1612 1613 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1614 res = c->func(rt, c->arg); 1615 if (res < 0) { 1616 w->leaf = rt; 1617 res = fib6_del(rt, &info); 1618 if (res) { 1619 #if RT6_DEBUG >= 2 1620 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1621 __func__, rt, rt->rt6i_node, res); 1622 #endif 1623 continue; 1624 } 1625 return 0; 1626 } 1627 WARN_ON(res != 0); 1628 } 1629 w->leaf = rt; 1630 return 0; 1631 } 1632 1633 /* 1634 * Convenient frontend to tree walker. 1635 * 1636 * func is called on each route. 1637 * It may return -1 -> delete this route. 1638 * 0 -> continue walking 1639 * 1640 * prune==1 -> only immediate children of node (certainly, 1641 * ignoring pure split nodes) will be scanned. 1642 */ 1643 1644 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1645 int (*func)(struct rt6_info *, void *arg), 1646 bool prune, int sernum, void *arg) 1647 { 1648 struct fib6_cleaner c; 1649 1650 c.w.root = root; 1651 c.w.func = fib6_clean_node; 1652 c.w.prune = prune; 1653 c.w.count = 0; 1654 c.w.skip = 0; 1655 c.func = func; 1656 c.sernum = sernum; 1657 c.arg = arg; 1658 c.net = net; 1659 1660 fib6_walk(&c.w); 1661 } 1662 1663 static void __fib6_clean_all(struct net *net, 1664 int (*func)(struct rt6_info *, void *), 1665 int sernum, void *arg) 1666 { 1667 struct fib6_table *table; 1668 struct hlist_head *head; 1669 unsigned int h; 1670 1671 rcu_read_lock(); 1672 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1673 head = &net->ipv6.fib_table_hash[h]; 1674 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1675 write_lock_bh(&table->tb6_lock); 1676 fib6_clean_tree(net, &table->tb6_root, 1677 func, false, sernum, arg); 1678 write_unlock_bh(&table->tb6_lock); 1679 } 1680 } 1681 rcu_read_unlock(); 1682 } 1683 1684 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1685 void *arg) 1686 { 1687 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1688 } 1689 1690 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1691 { 1692 if (rt->rt6i_flags & RTF_CACHE) { 1693 RT6_TRACE("pruning clone %p\n", rt); 1694 return -1; 1695 } 1696 1697 return 0; 1698 } 1699 1700 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1701 { 1702 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1703 FIB6_NO_SERNUM_CHANGE, NULL); 1704 } 1705 1706 static void fib6_flush_trees(struct net *net) 1707 { 1708 int new_sernum = fib6_new_sernum(net); 1709 1710 __fib6_clean_all(net, NULL, new_sernum, NULL); 1711 } 1712 1713 /* 1714 * Garbage collection 1715 */ 1716 1717 static struct fib6_gc_args 1718 { 1719 int timeout; 1720 int more; 1721 } gc_args; 1722 1723 static int fib6_age(struct rt6_info *rt, void *arg) 1724 { 1725 unsigned long now = jiffies; 1726 1727 /* 1728 * check addrconf expiration here. 1729 * Routes are expired even if they are in use. 1730 * 1731 * Also age clones. Note, that clones are aged out 1732 * only if they are not in use now. 1733 */ 1734 1735 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1736 if (time_after(now, rt->dst.expires)) { 1737 RT6_TRACE("expiring %p\n", rt); 1738 return -1; 1739 } 1740 gc_args.more++; 1741 } else if (rt->rt6i_flags & RTF_CACHE) { 1742 if (atomic_read(&rt->dst.__refcnt) == 0 && 1743 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1744 RT6_TRACE("aging clone %p\n", rt); 1745 return -1; 1746 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1747 struct neighbour *neigh; 1748 __u8 neigh_flags = 0; 1749 1750 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1751 if (neigh) { 1752 neigh_flags = neigh->flags; 1753 neigh_release(neigh); 1754 } 1755 if (!(neigh_flags & NTF_ROUTER)) { 1756 RT6_TRACE("purging route %p via non-router but gateway\n", 1757 rt); 1758 return -1; 1759 } 1760 } 1761 gc_args.more++; 1762 } 1763 1764 return 0; 1765 } 1766 1767 static DEFINE_SPINLOCK(fib6_gc_lock); 1768 1769 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1770 { 1771 unsigned long now; 1772 1773 if (force) { 1774 spin_lock_bh(&fib6_gc_lock); 1775 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1776 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1777 return; 1778 } 1779 gc_args.timeout = expires ? (int)expires : 1780 net->ipv6.sysctl.ip6_rt_gc_interval; 1781 1782 gc_args.more = icmp6_dst_gc(); 1783 1784 fib6_clean_all(net, fib6_age, NULL); 1785 now = jiffies; 1786 net->ipv6.ip6_rt_last_gc = now; 1787 1788 if (gc_args.more) 1789 mod_timer(&net->ipv6.ip6_fib_timer, 1790 round_jiffies(now 1791 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1792 else 1793 del_timer(&net->ipv6.ip6_fib_timer); 1794 spin_unlock_bh(&fib6_gc_lock); 1795 } 1796 1797 static void fib6_gc_timer_cb(unsigned long arg) 1798 { 1799 fib6_run_gc(0, (struct net *)arg, true); 1800 } 1801 1802 static int __net_init fib6_net_init(struct net *net) 1803 { 1804 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1805 1806 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1807 1808 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1809 if (!net->ipv6.rt6_stats) 1810 goto out_timer; 1811 1812 /* Avoid false sharing : Use at least a full cache line */ 1813 size = max_t(size_t, size, L1_CACHE_BYTES); 1814 1815 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1816 if (!net->ipv6.fib_table_hash) 1817 goto out_rt6_stats; 1818 1819 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1820 GFP_KERNEL); 1821 if (!net->ipv6.fib6_main_tbl) 1822 goto out_fib_table_hash; 1823 1824 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1825 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1826 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1827 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1828 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1829 1830 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1831 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1832 GFP_KERNEL); 1833 if (!net->ipv6.fib6_local_tbl) 1834 goto out_fib6_main_tbl; 1835 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1836 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1837 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1838 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1839 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1840 #endif 1841 fib6_tables_init(net); 1842 1843 return 0; 1844 1845 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1846 out_fib6_main_tbl: 1847 kfree(net->ipv6.fib6_main_tbl); 1848 #endif 1849 out_fib_table_hash: 1850 kfree(net->ipv6.fib_table_hash); 1851 out_rt6_stats: 1852 kfree(net->ipv6.rt6_stats); 1853 out_timer: 1854 return -ENOMEM; 1855 } 1856 1857 static void fib6_net_exit(struct net *net) 1858 { 1859 rt6_ifdown(net, NULL); 1860 del_timer_sync(&net->ipv6.ip6_fib_timer); 1861 1862 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1863 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1864 kfree(net->ipv6.fib6_local_tbl); 1865 #endif 1866 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1867 kfree(net->ipv6.fib6_main_tbl); 1868 kfree(net->ipv6.fib_table_hash); 1869 kfree(net->ipv6.rt6_stats); 1870 } 1871 1872 static struct pernet_operations fib6_net_ops = { 1873 .init = fib6_net_init, 1874 .exit = fib6_net_exit, 1875 }; 1876 1877 int __init fib6_init(void) 1878 { 1879 int ret = -ENOMEM; 1880 1881 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1882 sizeof(struct fib6_node), 1883 0, SLAB_HWCACHE_ALIGN, 1884 NULL); 1885 if (!fib6_node_kmem) 1886 goto out; 1887 1888 ret = register_pernet_subsys(&fib6_net_ops); 1889 if (ret) 1890 goto out_kmem_cache_create; 1891 1892 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1893 NULL); 1894 if (ret) 1895 goto out_unregister_subsys; 1896 1897 __fib6_flush_trees = fib6_flush_trees; 1898 out: 1899 return ret; 1900 1901 out_unregister_subsys: 1902 unregister_pernet_subsys(&fib6_net_ops); 1903 out_kmem_cache_create: 1904 kmem_cache_destroy(fib6_node_kmem); 1905 goto out; 1906 } 1907 1908 void fib6_gc_cleanup(void) 1909 { 1910 unregister_pernet_subsys(&fib6_net_ops); 1911 kmem_cache_destroy(fib6_node_kmem); 1912 } 1913 1914 #ifdef CONFIG_PROC_FS 1915 1916 struct ipv6_route_iter { 1917 struct seq_net_private p; 1918 struct fib6_walker w; 1919 loff_t skip; 1920 struct fib6_table *tbl; 1921 int sernum; 1922 }; 1923 1924 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1925 { 1926 struct rt6_info *rt = v; 1927 struct ipv6_route_iter *iter = seq->private; 1928 1929 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1930 1931 #ifdef CONFIG_IPV6_SUBTREES 1932 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1933 #else 1934 seq_puts(seq, "00000000000000000000000000000000 00 "); 1935 #endif 1936 if (rt->rt6i_flags & RTF_GATEWAY) 1937 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1938 else 1939 seq_puts(seq, "00000000000000000000000000000000"); 1940 1941 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1942 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1943 rt->dst.__use, rt->rt6i_flags, 1944 rt->dst.dev ? rt->dst.dev->name : ""); 1945 iter->w.leaf = NULL; 1946 return 0; 1947 } 1948 1949 static int ipv6_route_yield(struct fib6_walker *w) 1950 { 1951 struct ipv6_route_iter *iter = w->args; 1952 1953 if (!iter->skip) 1954 return 1; 1955 1956 do { 1957 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1958 iter->skip--; 1959 if (!iter->skip && iter->w.leaf) 1960 return 1; 1961 } while (iter->w.leaf); 1962 1963 return 0; 1964 } 1965 1966 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1967 { 1968 memset(&iter->w, 0, sizeof(iter->w)); 1969 iter->w.func = ipv6_route_yield; 1970 iter->w.root = &iter->tbl->tb6_root; 1971 iter->w.state = FWS_INIT; 1972 iter->w.node = iter->w.root; 1973 iter->w.args = iter; 1974 iter->sernum = iter->w.root->fn_sernum; 1975 INIT_LIST_HEAD(&iter->w.lh); 1976 fib6_walker_link(&iter->w); 1977 } 1978 1979 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1980 struct net *net) 1981 { 1982 unsigned int h; 1983 struct hlist_node *node; 1984 1985 if (tbl) { 1986 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1987 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1988 } else { 1989 h = 0; 1990 node = NULL; 1991 } 1992 1993 while (!node && h < FIB6_TABLE_HASHSZ) { 1994 node = rcu_dereference_bh( 1995 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 1996 } 1997 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 1998 } 1999 2000 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2001 { 2002 if (iter->sernum != iter->w.root->fn_sernum) { 2003 iter->sernum = iter->w.root->fn_sernum; 2004 iter->w.state = FWS_INIT; 2005 iter->w.node = iter->w.root; 2006 WARN_ON(iter->w.skip); 2007 iter->w.skip = iter->w.count; 2008 } 2009 } 2010 2011 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2012 { 2013 int r; 2014 struct rt6_info *n; 2015 struct net *net = seq_file_net(seq); 2016 struct ipv6_route_iter *iter = seq->private; 2017 2018 if (!v) 2019 goto iter_table; 2020 2021 n = ((struct rt6_info *)v)->dst.rt6_next; 2022 if (n) { 2023 ++*pos; 2024 return n; 2025 } 2026 2027 iter_table: 2028 ipv6_route_check_sernum(iter); 2029 read_lock(&iter->tbl->tb6_lock); 2030 r = fib6_walk_continue(&iter->w); 2031 read_unlock(&iter->tbl->tb6_lock); 2032 if (r > 0) { 2033 if (v) 2034 ++*pos; 2035 return iter->w.leaf; 2036 } else if (r < 0) { 2037 fib6_walker_unlink(&iter->w); 2038 return NULL; 2039 } 2040 fib6_walker_unlink(&iter->w); 2041 2042 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2043 if (!iter->tbl) 2044 return NULL; 2045 2046 ipv6_route_seq_setup_walk(iter); 2047 goto iter_table; 2048 } 2049 2050 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2051 __acquires(RCU_BH) 2052 { 2053 struct net *net = seq_file_net(seq); 2054 struct ipv6_route_iter *iter = seq->private; 2055 2056 rcu_read_lock_bh(); 2057 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2058 iter->skip = *pos; 2059 2060 if (iter->tbl) { 2061 ipv6_route_seq_setup_walk(iter); 2062 return ipv6_route_seq_next(seq, NULL, pos); 2063 } else { 2064 return NULL; 2065 } 2066 } 2067 2068 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2069 { 2070 struct fib6_walker *w = &iter->w; 2071 return w->node && !(w->state == FWS_U && w->node == w->root); 2072 } 2073 2074 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2075 __releases(RCU_BH) 2076 { 2077 struct ipv6_route_iter *iter = seq->private; 2078 2079 if (ipv6_route_iter_active(iter)) 2080 fib6_walker_unlink(&iter->w); 2081 2082 rcu_read_unlock_bh(); 2083 } 2084 2085 static const struct seq_operations ipv6_route_seq_ops = { 2086 .start = ipv6_route_seq_start, 2087 .next = ipv6_route_seq_next, 2088 .stop = ipv6_route_seq_stop, 2089 .show = ipv6_route_seq_show 2090 }; 2091 2092 int ipv6_route_open(struct inode *inode, struct file *file) 2093 { 2094 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2095 sizeof(struct ipv6_route_iter)); 2096 } 2097 2098 #endif /* CONFIG_PROC_FS */ 2099