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