1 /* 2 * Linux INET6 implementation 3 * Forwarding Information Database 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * Changes: 14 * Yuji SEKIYA @USAGI: Support default route on router node; 15 * remove ip6_null_entry from the top of 16 * routing table. 17 * Ville Nuorvala: Fixed routing subtrees. 18 */ 19 20 #define pr_fmt(fmt) "IPv6: " fmt 21 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/net.h> 25 #include <linux/route.h> 26 #include <linux/netdevice.h> 27 #include <linux/in6.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/slab.h> 31 32 #include <net/ipv6.h> 33 #include <net/ndisc.h> 34 #include <net/addrconf.h> 35 36 #include <net/ip6_fib.h> 37 #include <net/ip6_route.h> 38 39 #define RT6_DEBUG 2 40 41 #if RT6_DEBUG >= 3 42 #define RT6_TRACE(x...) pr_debug(x) 43 #else 44 #define RT6_TRACE(x...) do { ; } while (0) 45 #endif 46 47 static struct kmem_cache *fib6_node_kmem __read_mostly; 48 49 struct fib6_cleaner { 50 struct fib6_walker w; 51 struct net *net; 52 int (*func)(struct rt6_info *, void *arg); 53 int sernum; 54 void *arg; 55 }; 56 57 static DEFINE_RWLOCK(fib6_walker_lock); 58 59 #ifdef CONFIG_IPV6_SUBTREES 60 #define FWS_INIT FWS_S 61 #else 62 #define FWS_INIT FWS_L 63 #endif 64 65 static void fib6_prune_clones(struct net *net, struct fib6_node *fn); 66 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 67 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 68 static int fib6_walk(struct fib6_walker *w); 69 static int fib6_walk_continue(struct fib6_walker *w); 70 71 /* 72 * A routing update causes an increase of the serial number on the 73 * affected subtree. This allows for cached routes to be asynchronously 74 * tested when modifications are made to the destination cache as a 75 * result of redirects, path MTU changes, etc. 76 */ 77 78 static void fib6_gc_timer_cb(unsigned long arg); 79 80 static LIST_HEAD(fib6_walkers); 81 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh) 82 83 static void fib6_walker_link(struct fib6_walker *w) 84 { 85 write_lock_bh(&fib6_walker_lock); 86 list_add(&w->lh, &fib6_walkers); 87 write_unlock_bh(&fib6_walker_lock); 88 } 89 90 static void fib6_walker_unlink(struct fib6_walker *w) 91 { 92 write_lock_bh(&fib6_walker_lock); 93 list_del(&w->lh); 94 write_unlock_bh(&fib6_walker_lock); 95 } 96 97 static int fib6_new_sernum(struct net *net) 98 { 99 int new, old; 100 101 do { 102 old = atomic_read(&net->ipv6.fib6_sernum); 103 new = old < INT_MAX ? old + 1 : 1; 104 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 105 old, new) != old); 106 return new; 107 } 108 109 enum { 110 FIB6_NO_SERNUM_CHANGE = 0, 111 }; 112 113 /* 114 * Auxiliary address test functions for the radix tree. 115 * 116 * These assume a 32bit processor (although it will work on 117 * 64bit processors) 118 */ 119 120 /* 121 * test bit 122 */ 123 #if defined(__LITTLE_ENDIAN) 124 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 125 #else 126 # define BITOP_BE32_SWIZZLE 0 127 #endif 128 129 static __be32 addr_bit_set(const void *token, int fn_bit) 130 { 131 const __be32 *addr = token; 132 /* 133 * Here, 134 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 135 * is optimized version of 136 * htonl(1 << ((~fn_bit)&0x1F)) 137 * See include/asm-generic/bitops/le.h. 138 */ 139 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 140 addr[fn_bit >> 5]; 141 } 142 143 static struct fib6_node *node_alloc(void) 144 { 145 struct fib6_node *fn; 146 147 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 148 149 return fn; 150 } 151 152 static void node_free(struct fib6_node *fn) 153 { 154 kmem_cache_free(fib6_node_kmem, fn); 155 } 156 157 static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) 158 { 159 int cpu; 160 161 if (!non_pcpu_rt->rt6i_pcpu) 162 return; 163 164 for_each_possible_cpu(cpu) { 165 struct rt6_info **ppcpu_rt; 166 struct rt6_info *pcpu_rt; 167 168 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 169 pcpu_rt = *ppcpu_rt; 170 if (pcpu_rt) { 171 dst_free(&pcpu_rt->dst); 172 *ppcpu_rt = NULL; 173 } 174 } 175 176 non_pcpu_rt->rt6i_pcpu = NULL; 177 } 178 179 static void rt6_release(struct rt6_info *rt) 180 { 181 if (atomic_dec_and_test(&rt->rt6i_ref)) { 182 rt6_free_pcpu(rt); 183 dst_free(&rt->dst); 184 } 185 } 186 187 static void fib6_link_table(struct net *net, struct fib6_table *tb) 188 { 189 unsigned int h; 190 191 /* 192 * Initialize table lock at a single place to give lockdep a key, 193 * tables aren't visible prior to being linked to the list. 194 */ 195 rwlock_init(&tb->tb6_lock); 196 197 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 198 199 /* 200 * No protection necessary, this is the only list mutatation 201 * operation, tables never disappear once they exist. 202 */ 203 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 204 } 205 206 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 207 208 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 209 { 210 struct fib6_table *table; 211 212 table = kzalloc(sizeof(*table), GFP_ATOMIC); 213 if (table) { 214 table->tb6_id = id; 215 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 216 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 217 inet_peer_base_init(&table->tb6_peers); 218 } 219 220 return table; 221 } 222 223 struct fib6_table *fib6_new_table(struct net *net, u32 id) 224 { 225 struct fib6_table *tb; 226 227 if (id == 0) 228 id = RT6_TABLE_MAIN; 229 tb = fib6_get_table(net, id); 230 if (tb) 231 return tb; 232 233 tb = fib6_alloc_table(net, id); 234 if (tb) 235 fib6_link_table(net, tb); 236 237 return tb; 238 } 239 240 struct fib6_table *fib6_get_table(struct net *net, u32 id) 241 { 242 struct fib6_table *tb; 243 struct hlist_head *head; 244 unsigned int h; 245 246 if (id == 0) 247 id = RT6_TABLE_MAIN; 248 h = id & (FIB6_TABLE_HASHSZ - 1); 249 rcu_read_lock(); 250 head = &net->ipv6.fib_table_hash[h]; 251 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 252 if (tb->tb6_id == id) { 253 rcu_read_unlock(); 254 return tb; 255 } 256 } 257 rcu_read_unlock(); 258 259 return NULL; 260 } 261 262 static void __net_init fib6_tables_init(struct net *net) 263 { 264 fib6_link_table(net, net->ipv6.fib6_main_tbl); 265 fib6_link_table(net, net->ipv6.fib6_local_tbl); 266 } 267 #else 268 269 struct fib6_table *fib6_new_table(struct net *net, u32 id) 270 { 271 return fib6_get_table(net, id); 272 } 273 274 struct fib6_table *fib6_get_table(struct net *net, u32 id) 275 { 276 return net->ipv6.fib6_main_tbl; 277 } 278 279 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 280 int flags, pol_lookup_t lookup) 281 { 282 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 283 } 284 285 static void __net_init fib6_tables_init(struct net *net) 286 { 287 fib6_link_table(net, net->ipv6.fib6_main_tbl); 288 } 289 290 #endif 291 292 static int fib6_dump_node(struct fib6_walker *w) 293 { 294 int res; 295 struct rt6_info *rt; 296 297 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 298 res = rt6_dump_route(rt, w->args); 299 if (res < 0) { 300 /* Frame is full, suspend walking */ 301 w->leaf = rt; 302 return 1; 303 } 304 } 305 w->leaf = NULL; 306 return 0; 307 } 308 309 static void fib6_dump_end(struct netlink_callback *cb) 310 { 311 struct fib6_walker *w = (void *)cb->args[2]; 312 313 if (w) { 314 if (cb->args[4]) { 315 cb->args[4] = 0; 316 fib6_walker_unlink(w); 317 } 318 cb->args[2] = 0; 319 kfree(w); 320 } 321 cb->done = (void *)cb->args[3]; 322 cb->args[1] = 3; 323 } 324 325 static int fib6_dump_done(struct netlink_callback *cb) 326 { 327 fib6_dump_end(cb); 328 return cb->done ? cb->done(cb) : 0; 329 } 330 331 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 332 struct netlink_callback *cb) 333 { 334 struct fib6_walker *w; 335 int res; 336 337 w = (void *)cb->args[2]; 338 w->root = &table->tb6_root; 339 340 if (cb->args[4] == 0) { 341 w->count = 0; 342 w->skip = 0; 343 344 read_lock_bh(&table->tb6_lock); 345 res = fib6_walk(w); 346 read_unlock_bh(&table->tb6_lock); 347 if (res > 0) { 348 cb->args[4] = 1; 349 cb->args[5] = w->root->fn_sernum; 350 } 351 } else { 352 if (cb->args[5] != w->root->fn_sernum) { 353 /* Begin at the root if the tree changed */ 354 cb->args[5] = w->root->fn_sernum; 355 w->state = FWS_INIT; 356 w->node = w->root; 357 w->skip = w->count; 358 } else 359 w->skip = 0; 360 361 read_lock_bh(&table->tb6_lock); 362 res = fib6_walk_continue(w); 363 read_unlock_bh(&table->tb6_lock); 364 if (res <= 0) { 365 fib6_walker_unlink(w); 366 cb->args[4] = 0; 367 } 368 } 369 370 return res; 371 } 372 373 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 374 { 375 struct net *net = sock_net(skb->sk); 376 unsigned int h, s_h; 377 unsigned int e = 0, s_e; 378 struct rt6_rtnl_dump_arg arg; 379 struct fib6_walker *w; 380 struct fib6_table *tb; 381 struct hlist_head *head; 382 int res = 0; 383 384 s_h = cb->args[0]; 385 s_e = cb->args[1]; 386 387 w = (void *)cb->args[2]; 388 if (!w) { 389 /* New dump: 390 * 391 * 1. hook callback destructor. 392 */ 393 cb->args[3] = (long)cb->done; 394 cb->done = fib6_dump_done; 395 396 /* 397 * 2. allocate and initialize walker. 398 */ 399 w = kzalloc(sizeof(*w), GFP_ATOMIC); 400 if (!w) 401 return -ENOMEM; 402 w->func = fib6_dump_node; 403 cb->args[2] = (long)w; 404 } 405 406 arg.skb = skb; 407 arg.cb = cb; 408 arg.net = net; 409 w->args = &arg; 410 411 rcu_read_lock(); 412 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 413 e = 0; 414 head = &net->ipv6.fib_table_hash[h]; 415 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 416 if (e < s_e) 417 goto next; 418 res = fib6_dump_table(tb, skb, cb); 419 if (res != 0) 420 goto out; 421 next: 422 e++; 423 } 424 } 425 out: 426 rcu_read_unlock(); 427 cb->args[1] = e; 428 cb->args[0] = h; 429 430 res = res < 0 ? res : skb->len; 431 if (res <= 0) 432 fib6_dump_end(cb); 433 return res; 434 } 435 436 /* 437 * Routing Table 438 * 439 * return the appropriate node for a routing tree "add" operation 440 * by either creating and inserting or by returning an existing 441 * node. 442 */ 443 444 static struct fib6_node *fib6_add_1(struct fib6_node *root, 445 struct in6_addr *addr, int plen, 446 int offset, int allow_create, 447 int replace_required, int sernum) 448 { 449 struct fib6_node *fn, *in, *ln; 450 struct fib6_node *pn = NULL; 451 struct rt6key *key; 452 int bit; 453 __be32 dir = 0; 454 455 RT6_TRACE("fib6_add_1\n"); 456 457 /* insert node in tree */ 458 459 fn = root; 460 461 do { 462 key = (struct rt6key *)((u8 *)fn->leaf + offset); 463 464 /* 465 * Prefix match 466 */ 467 if (plen < fn->fn_bit || 468 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 469 if (!allow_create) { 470 if (replace_required) { 471 pr_warn("Can't replace route, no match found\n"); 472 return ERR_PTR(-ENOENT); 473 } 474 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 475 } 476 goto insert_above; 477 } 478 479 /* 480 * Exact match ? 481 */ 482 483 if (plen == fn->fn_bit) { 484 /* clean up an intermediate node */ 485 if (!(fn->fn_flags & RTN_RTINFO)) { 486 rt6_release(fn->leaf); 487 fn->leaf = NULL; 488 } 489 490 fn->fn_sernum = sernum; 491 492 return fn; 493 } 494 495 /* 496 * We have more bits to go 497 */ 498 499 /* Try to walk down on tree. */ 500 fn->fn_sernum = sernum; 501 dir = addr_bit_set(addr, fn->fn_bit); 502 pn = fn; 503 fn = dir ? fn->right : fn->left; 504 } while (fn); 505 506 if (!allow_create) { 507 /* We should not create new node because 508 * NLM_F_REPLACE was specified without NLM_F_CREATE 509 * I assume it is safe to require NLM_F_CREATE when 510 * REPLACE flag is used! Later we may want to remove the 511 * check for replace_required, because according 512 * to netlink specification, NLM_F_CREATE 513 * MUST be specified if new route is created. 514 * That would keep IPv6 consistent with IPv4 515 */ 516 if (replace_required) { 517 pr_warn("Can't replace route, no match found\n"); 518 return ERR_PTR(-ENOENT); 519 } 520 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 521 } 522 /* 523 * We walked to the bottom of tree. 524 * Create new leaf node without children. 525 */ 526 527 ln = node_alloc(); 528 529 if (!ln) 530 return ERR_PTR(-ENOMEM); 531 ln->fn_bit = plen; 532 533 ln->parent = pn; 534 ln->fn_sernum = sernum; 535 536 if (dir) 537 pn->right = ln; 538 else 539 pn->left = ln; 540 541 return ln; 542 543 544 insert_above: 545 /* 546 * split since we don't have a common prefix anymore or 547 * we have a less significant route. 548 * we've to insert an intermediate node on the list 549 * this new node will point to the one we need to create 550 * and the current 551 */ 552 553 pn = fn->parent; 554 555 /* find 1st bit in difference between the 2 addrs. 556 557 See comment in __ipv6_addr_diff: bit may be an invalid value, 558 but if it is >= plen, the value is ignored in any case. 559 */ 560 561 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 562 563 /* 564 * (intermediate)[in] 565 * / \ 566 * (new leaf node)[ln] (old node)[fn] 567 */ 568 if (plen > bit) { 569 in = node_alloc(); 570 ln = node_alloc(); 571 572 if (!in || !ln) { 573 if (in) 574 node_free(in); 575 if (ln) 576 node_free(ln); 577 return ERR_PTR(-ENOMEM); 578 } 579 580 /* 581 * new intermediate node. 582 * RTN_RTINFO will 583 * be off since that an address that chooses one of 584 * the branches would not match less specific routes 585 * in the other branch 586 */ 587 588 in->fn_bit = bit; 589 590 in->parent = pn; 591 in->leaf = fn->leaf; 592 atomic_inc(&in->leaf->rt6i_ref); 593 594 in->fn_sernum = sernum; 595 596 /* update parent pointer */ 597 if (dir) 598 pn->right = in; 599 else 600 pn->left = in; 601 602 ln->fn_bit = plen; 603 604 ln->parent = in; 605 fn->parent = in; 606 607 ln->fn_sernum = sernum; 608 609 if (addr_bit_set(addr, bit)) { 610 in->right = ln; 611 in->left = fn; 612 } else { 613 in->left = ln; 614 in->right = fn; 615 } 616 } else { /* plen <= bit */ 617 618 /* 619 * (new leaf node)[ln] 620 * / \ 621 * (old node)[fn] NULL 622 */ 623 624 ln = node_alloc(); 625 626 if (!ln) 627 return ERR_PTR(-ENOMEM); 628 629 ln->fn_bit = plen; 630 631 ln->parent = pn; 632 633 ln->fn_sernum = sernum; 634 635 if (dir) 636 pn->right = ln; 637 else 638 pn->left = ln; 639 640 if (addr_bit_set(&key->addr, plen)) 641 ln->right = fn; 642 else 643 ln->left = fn; 644 645 fn->parent = ln; 646 } 647 return ln; 648 } 649 650 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 651 { 652 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 653 RTF_GATEWAY; 654 } 655 656 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 657 { 658 int i; 659 660 for (i = 0; i < RTAX_MAX; i++) { 661 if (test_bit(i, mxc->mx_valid)) 662 mp[i] = mxc->mx[i]; 663 } 664 } 665 666 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 667 { 668 if (!mxc->mx) 669 return 0; 670 671 if (dst->flags & DST_HOST) { 672 u32 *mp = dst_metrics_write_ptr(dst); 673 674 if (unlikely(!mp)) 675 return -ENOMEM; 676 677 fib6_copy_metrics(mp, mxc); 678 } else { 679 dst_init_metrics(dst, mxc->mx, false); 680 681 /* We've stolen mx now. */ 682 mxc->mx = NULL; 683 } 684 685 return 0; 686 } 687 688 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 689 struct net *net) 690 { 691 if (atomic_read(&rt->rt6i_ref) != 1) { 692 /* This route is used as dummy address holder in some split 693 * nodes. It is not leaked, but it still holds other resources, 694 * which must be released in time. So, scan ascendant nodes 695 * and replace dummy references to this route with references 696 * to still alive ones. 697 */ 698 while (fn) { 699 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 700 fn->leaf = fib6_find_prefix(net, fn); 701 atomic_inc(&fn->leaf->rt6i_ref); 702 rt6_release(rt); 703 } 704 fn = fn->parent; 705 } 706 /* No more references are possible at this point. */ 707 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 708 } 709 } 710 711 /* 712 * Insert routing information in a node. 713 */ 714 715 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 716 struct nl_info *info, struct mx6_config *mxc) 717 { 718 struct rt6_info *iter = NULL; 719 struct rt6_info **ins; 720 struct rt6_info **fallback_ins = NULL; 721 int replace = (info->nlh && 722 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 723 int add = (!info->nlh || 724 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 725 int found = 0; 726 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 727 int err; 728 729 ins = &fn->leaf; 730 731 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 732 /* 733 * Search for duplicates 734 */ 735 736 if (iter->rt6i_metric == rt->rt6i_metric) { 737 /* 738 * Same priority level 739 */ 740 if (info->nlh && 741 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 742 return -EEXIST; 743 if (replace) { 744 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 745 found++; 746 break; 747 } 748 if (rt_can_ecmp) 749 fallback_ins = fallback_ins ?: ins; 750 goto next_iter; 751 } 752 753 if (iter->dst.dev == rt->dst.dev && 754 iter->rt6i_idev == rt->rt6i_idev && 755 ipv6_addr_equal(&iter->rt6i_gateway, 756 &rt->rt6i_gateway)) { 757 if (rt->rt6i_nsiblings) 758 rt->rt6i_nsiblings = 0; 759 if (!(iter->rt6i_flags & RTF_EXPIRES)) 760 return -EEXIST; 761 if (!(rt->rt6i_flags & RTF_EXPIRES)) 762 rt6_clean_expires(iter); 763 else 764 rt6_set_expires(iter, rt->dst.expires); 765 iter->rt6i_pmtu = rt->rt6i_pmtu; 766 return -EEXIST; 767 } 768 /* If we have the same destination and the same metric, 769 * but not the same gateway, then the route we try to 770 * add is sibling to this route, increment our counter 771 * of siblings, and later we will add our route to the 772 * list. 773 * Only static routes (which don't have flag 774 * RTF_EXPIRES) are used for ECMPv6. 775 * 776 * To avoid long list, we only had siblings if the 777 * route have a gateway. 778 */ 779 if (rt_can_ecmp && 780 rt6_qualify_for_ecmp(iter)) 781 rt->rt6i_nsiblings++; 782 } 783 784 if (iter->rt6i_metric > rt->rt6i_metric) 785 break; 786 787 next_iter: 788 ins = &iter->dst.rt6_next; 789 } 790 791 if (fallback_ins && !found) { 792 /* No ECMP-able route found, replace first non-ECMP one */ 793 ins = fallback_ins; 794 iter = *ins; 795 found++; 796 } 797 798 /* Reset round-robin state, if necessary */ 799 if (ins == &fn->leaf) 800 fn->rr_ptr = NULL; 801 802 /* Link this route to others same route. */ 803 if (rt->rt6i_nsiblings) { 804 unsigned int rt6i_nsiblings; 805 struct rt6_info *sibling, *temp_sibling; 806 807 /* Find the first route that have the same metric */ 808 sibling = fn->leaf; 809 while (sibling) { 810 if (sibling->rt6i_metric == rt->rt6i_metric && 811 rt6_qualify_for_ecmp(sibling)) { 812 list_add_tail(&rt->rt6i_siblings, 813 &sibling->rt6i_siblings); 814 break; 815 } 816 sibling = sibling->dst.rt6_next; 817 } 818 /* For each sibling in the list, increment the counter of 819 * siblings. BUG() if counters does not match, list of siblings 820 * is broken! 821 */ 822 rt6i_nsiblings = 0; 823 list_for_each_entry_safe(sibling, temp_sibling, 824 &rt->rt6i_siblings, rt6i_siblings) { 825 sibling->rt6i_nsiblings++; 826 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 827 rt6i_nsiblings++; 828 } 829 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 830 } 831 832 /* 833 * insert node 834 */ 835 if (!replace) { 836 if (!add) 837 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 838 839 add: 840 err = fib6_commit_metrics(&rt->dst, mxc); 841 if (err) 842 return err; 843 844 rt->dst.rt6_next = iter; 845 *ins = rt; 846 rt->rt6i_node = fn; 847 atomic_inc(&rt->rt6i_ref); 848 inet6_rt_notify(RTM_NEWROUTE, rt, info); 849 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 850 851 if (!(fn->fn_flags & RTN_RTINFO)) { 852 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 853 fn->fn_flags |= RTN_RTINFO; 854 } 855 856 } else { 857 int nsiblings; 858 859 if (!found) { 860 if (add) 861 goto add; 862 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 863 return -ENOENT; 864 } 865 866 err = fib6_commit_metrics(&rt->dst, mxc); 867 if (err) 868 return err; 869 870 *ins = rt; 871 rt->rt6i_node = fn; 872 rt->dst.rt6_next = iter->dst.rt6_next; 873 atomic_inc(&rt->rt6i_ref); 874 inet6_rt_notify(RTM_NEWROUTE, rt, info); 875 if (!(fn->fn_flags & RTN_RTINFO)) { 876 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 877 fn->fn_flags |= RTN_RTINFO; 878 } 879 nsiblings = iter->rt6i_nsiblings; 880 fib6_purge_rt(iter, fn, info->nl_net); 881 rt6_release(iter); 882 883 if (nsiblings) { 884 /* Replacing an ECMP route, remove all siblings */ 885 ins = &rt->dst.rt6_next; 886 iter = *ins; 887 while (iter) { 888 if (rt6_qualify_for_ecmp(iter)) { 889 *ins = iter->dst.rt6_next; 890 fib6_purge_rt(iter, fn, info->nl_net); 891 rt6_release(iter); 892 nsiblings--; 893 } else { 894 ins = &iter->dst.rt6_next; 895 } 896 iter = *ins; 897 } 898 WARN_ON(nsiblings != 0); 899 } 900 } 901 902 return 0; 903 } 904 905 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 906 { 907 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 908 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 909 mod_timer(&net->ipv6.ip6_fib_timer, 910 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 911 } 912 913 void fib6_force_start_gc(struct net *net) 914 { 915 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 916 mod_timer(&net->ipv6.ip6_fib_timer, 917 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 918 } 919 920 /* 921 * Add routing information to the routing tree. 922 * <destination addr>/<source addr> 923 * with source addr info in sub-trees 924 */ 925 926 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 927 struct nl_info *info, struct mx6_config *mxc) 928 { 929 struct fib6_node *fn, *pn = NULL; 930 int err = -ENOMEM; 931 int allow_create = 1; 932 int replace_required = 0; 933 int sernum = fib6_new_sernum(info->nl_net); 934 935 if (info->nlh) { 936 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 937 allow_create = 0; 938 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 939 replace_required = 1; 940 } 941 if (!allow_create && !replace_required) 942 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 943 944 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 945 offsetof(struct rt6_info, rt6i_dst), allow_create, 946 replace_required, sernum); 947 if (IS_ERR(fn)) { 948 err = PTR_ERR(fn); 949 fn = NULL; 950 goto out; 951 } 952 953 pn = fn; 954 955 #ifdef CONFIG_IPV6_SUBTREES 956 if (rt->rt6i_src.plen) { 957 struct fib6_node *sn; 958 959 if (!fn->subtree) { 960 struct fib6_node *sfn; 961 962 /* 963 * Create subtree. 964 * 965 * fn[main tree] 966 * | 967 * sfn[subtree root] 968 * \ 969 * sn[new leaf node] 970 */ 971 972 /* Create subtree root node */ 973 sfn = node_alloc(); 974 if (!sfn) 975 goto st_failure; 976 977 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 978 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 979 sfn->fn_flags = RTN_ROOT; 980 sfn->fn_sernum = sernum; 981 982 /* Now add the first leaf node to new subtree */ 983 984 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 985 rt->rt6i_src.plen, 986 offsetof(struct rt6_info, rt6i_src), 987 allow_create, replace_required, sernum); 988 989 if (IS_ERR(sn)) { 990 /* If it is failed, discard just allocated 991 root, and then (in st_failure) stale node 992 in main tree. 993 */ 994 node_free(sfn); 995 err = PTR_ERR(sn); 996 goto st_failure; 997 } 998 999 /* Now link new subtree to main tree */ 1000 sfn->parent = fn; 1001 fn->subtree = sfn; 1002 } else { 1003 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 1004 rt->rt6i_src.plen, 1005 offsetof(struct rt6_info, rt6i_src), 1006 allow_create, replace_required, sernum); 1007 1008 if (IS_ERR(sn)) { 1009 err = PTR_ERR(sn); 1010 goto st_failure; 1011 } 1012 } 1013 1014 if (!fn->leaf) { 1015 fn->leaf = rt; 1016 atomic_inc(&rt->rt6i_ref); 1017 } 1018 fn = sn; 1019 } 1020 #endif 1021 1022 err = fib6_add_rt2node(fn, rt, info, mxc); 1023 if (!err) { 1024 fib6_start_gc(info->nl_net, rt); 1025 if (!(rt->rt6i_flags & RTF_CACHE)) 1026 fib6_prune_clones(info->nl_net, pn); 1027 } 1028 1029 out: 1030 if (err) { 1031 #ifdef CONFIG_IPV6_SUBTREES 1032 /* 1033 * If fib6_add_1 has cleared the old leaf pointer in the 1034 * super-tree leaf node we have to find a new one for it. 1035 */ 1036 if (pn != fn && pn->leaf == rt) { 1037 pn->leaf = NULL; 1038 atomic_dec(&rt->rt6i_ref); 1039 } 1040 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 1041 pn->leaf = fib6_find_prefix(info->nl_net, pn); 1042 #if RT6_DEBUG >= 2 1043 if (!pn->leaf) { 1044 WARN_ON(pn->leaf == NULL); 1045 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 1046 } 1047 #endif 1048 atomic_inc(&pn->leaf->rt6i_ref); 1049 } 1050 #endif 1051 dst_free(&rt->dst); 1052 } 1053 return err; 1054 1055 #ifdef CONFIG_IPV6_SUBTREES 1056 /* Subtree creation failed, probably main tree node 1057 is orphan. If it is, shoot it. 1058 */ 1059 st_failure: 1060 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1061 fib6_repair_tree(info->nl_net, fn); 1062 dst_free(&rt->dst); 1063 return err; 1064 #endif 1065 } 1066 1067 /* 1068 * Routing tree lookup 1069 * 1070 */ 1071 1072 struct lookup_args { 1073 int offset; /* key offset on rt6_info */ 1074 const struct in6_addr *addr; /* search key */ 1075 }; 1076 1077 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1078 struct lookup_args *args) 1079 { 1080 struct fib6_node *fn; 1081 __be32 dir; 1082 1083 if (unlikely(args->offset == 0)) 1084 return NULL; 1085 1086 /* 1087 * Descend on a tree 1088 */ 1089 1090 fn = root; 1091 1092 for (;;) { 1093 struct fib6_node *next; 1094 1095 dir = addr_bit_set(args->addr, fn->fn_bit); 1096 1097 next = dir ? fn->right : fn->left; 1098 1099 if (next) { 1100 fn = next; 1101 continue; 1102 } 1103 break; 1104 } 1105 1106 while (fn) { 1107 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1108 struct rt6key *key; 1109 1110 key = (struct rt6key *) ((u8 *) fn->leaf + 1111 args->offset); 1112 1113 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1114 #ifdef CONFIG_IPV6_SUBTREES 1115 if (fn->subtree) { 1116 struct fib6_node *sfn; 1117 sfn = fib6_lookup_1(fn->subtree, 1118 args + 1); 1119 if (!sfn) 1120 goto backtrack; 1121 fn = sfn; 1122 } 1123 #endif 1124 if (fn->fn_flags & RTN_RTINFO) 1125 return fn; 1126 } 1127 } 1128 #ifdef CONFIG_IPV6_SUBTREES 1129 backtrack: 1130 #endif 1131 if (fn->fn_flags & RTN_ROOT) 1132 break; 1133 1134 fn = fn->parent; 1135 } 1136 1137 return NULL; 1138 } 1139 1140 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1141 const struct in6_addr *saddr) 1142 { 1143 struct fib6_node *fn; 1144 struct lookup_args args[] = { 1145 { 1146 .offset = offsetof(struct rt6_info, rt6i_dst), 1147 .addr = daddr, 1148 }, 1149 #ifdef CONFIG_IPV6_SUBTREES 1150 { 1151 .offset = offsetof(struct rt6_info, rt6i_src), 1152 .addr = saddr, 1153 }, 1154 #endif 1155 { 1156 .offset = 0, /* sentinel */ 1157 } 1158 }; 1159 1160 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1161 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1162 fn = root; 1163 1164 return fn; 1165 } 1166 1167 /* 1168 * Get node with specified destination prefix (and source prefix, 1169 * if subtrees are used) 1170 */ 1171 1172 1173 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1174 const struct in6_addr *addr, 1175 int plen, int offset) 1176 { 1177 struct fib6_node *fn; 1178 1179 for (fn = root; fn ; ) { 1180 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1181 1182 /* 1183 * Prefix match 1184 */ 1185 if (plen < fn->fn_bit || 1186 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1187 return NULL; 1188 1189 if (plen == fn->fn_bit) 1190 return fn; 1191 1192 /* 1193 * We have more bits to go 1194 */ 1195 if (addr_bit_set(addr, fn->fn_bit)) 1196 fn = fn->right; 1197 else 1198 fn = fn->left; 1199 } 1200 return NULL; 1201 } 1202 1203 struct fib6_node *fib6_locate(struct fib6_node *root, 1204 const struct in6_addr *daddr, int dst_len, 1205 const struct in6_addr *saddr, int src_len) 1206 { 1207 struct fib6_node *fn; 1208 1209 fn = fib6_locate_1(root, daddr, dst_len, 1210 offsetof(struct rt6_info, rt6i_dst)); 1211 1212 #ifdef CONFIG_IPV6_SUBTREES 1213 if (src_len) { 1214 WARN_ON(saddr == NULL); 1215 if (fn && fn->subtree) 1216 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1217 offsetof(struct rt6_info, rt6i_src)); 1218 } 1219 #endif 1220 1221 if (fn && fn->fn_flags & RTN_RTINFO) 1222 return fn; 1223 1224 return NULL; 1225 } 1226 1227 1228 /* 1229 * Deletion 1230 * 1231 */ 1232 1233 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1234 { 1235 if (fn->fn_flags & RTN_ROOT) 1236 return net->ipv6.ip6_null_entry; 1237 1238 while (fn) { 1239 if (fn->left) 1240 return fn->left->leaf; 1241 if (fn->right) 1242 return fn->right->leaf; 1243 1244 fn = FIB6_SUBTREE(fn); 1245 } 1246 return NULL; 1247 } 1248 1249 /* 1250 * Called to trim the tree of intermediate nodes when possible. "fn" 1251 * is the node we want to try and remove. 1252 */ 1253 1254 static struct fib6_node *fib6_repair_tree(struct net *net, 1255 struct fib6_node *fn) 1256 { 1257 int children; 1258 int nstate; 1259 struct fib6_node *child, *pn; 1260 struct fib6_walker *w; 1261 int iter = 0; 1262 1263 for (;;) { 1264 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1265 iter++; 1266 1267 WARN_ON(fn->fn_flags & RTN_RTINFO); 1268 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1269 WARN_ON(fn->leaf); 1270 1271 children = 0; 1272 child = NULL; 1273 if (fn->right) 1274 child = fn->right, children |= 1; 1275 if (fn->left) 1276 child = fn->left, children |= 2; 1277 1278 if (children == 3 || FIB6_SUBTREE(fn) 1279 #ifdef CONFIG_IPV6_SUBTREES 1280 /* Subtree root (i.e. fn) may have one child */ 1281 || (children && fn->fn_flags & RTN_ROOT) 1282 #endif 1283 ) { 1284 fn->leaf = fib6_find_prefix(net, fn); 1285 #if RT6_DEBUG >= 2 1286 if (!fn->leaf) { 1287 WARN_ON(!fn->leaf); 1288 fn->leaf = net->ipv6.ip6_null_entry; 1289 } 1290 #endif 1291 atomic_inc(&fn->leaf->rt6i_ref); 1292 return fn->parent; 1293 } 1294 1295 pn = fn->parent; 1296 #ifdef CONFIG_IPV6_SUBTREES 1297 if (FIB6_SUBTREE(pn) == fn) { 1298 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1299 FIB6_SUBTREE(pn) = NULL; 1300 nstate = FWS_L; 1301 } else { 1302 WARN_ON(fn->fn_flags & RTN_ROOT); 1303 #endif 1304 if (pn->right == fn) 1305 pn->right = child; 1306 else if (pn->left == fn) 1307 pn->left = child; 1308 #if RT6_DEBUG >= 2 1309 else 1310 WARN_ON(1); 1311 #endif 1312 if (child) 1313 child->parent = pn; 1314 nstate = FWS_R; 1315 #ifdef CONFIG_IPV6_SUBTREES 1316 } 1317 #endif 1318 1319 read_lock(&fib6_walker_lock); 1320 FOR_WALKERS(w) { 1321 if (!child) { 1322 if (w->root == fn) { 1323 w->root = w->node = NULL; 1324 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1325 } else if (w->node == fn) { 1326 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1327 w->node = pn; 1328 w->state = nstate; 1329 } 1330 } else { 1331 if (w->root == fn) { 1332 w->root = child; 1333 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1334 } 1335 if (w->node == fn) { 1336 w->node = child; 1337 if (children&2) { 1338 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1339 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1340 } else { 1341 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1342 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1343 } 1344 } 1345 } 1346 } 1347 read_unlock(&fib6_walker_lock); 1348 1349 node_free(fn); 1350 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1351 return pn; 1352 1353 rt6_release(pn->leaf); 1354 pn->leaf = NULL; 1355 fn = pn; 1356 } 1357 } 1358 1359 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1360 struct nl_info *info) 1361 { 1362 struct fib6_walker *w; 1363 struct rt6_info *rt = *rtp; 1364 struct net *net = info->nl_net; 1365 1366 RT6_TRACE("fib6_del_route\n"); 1367 1368 /* Unlink it */ 1369 *rtp = rt->dst.rt6_next; 1370 rt->rt6i_node = NULL; 1371 net->ipv6.rt6_stats->fib_rt_entries--; 1372 net->ipv6.rt6_stats->fib_discarded_routes++; 1373 1374 /* Reset round-robin state, if necessary */ 1375 if (fn->rr_ptr == rt) 1376 fn->rr_ptr = NULL; 1377 1378 /* Remove this entry from other siblings */ 1379 if (rt->rt6i_nsiblings) { 1380 struct rt6_info *sibling, *next_sibling; 1381 1382 list_for_each_entry_safe(sibling, next_sibling, 1383 &rt->rt6i_siblings, rt6i_siblings) 1384 sibling->rt6i_nsiblings--; 1385 rt->rt6i_nsiblings = 0; 1386 list_del_init(&rt->rt6i_siblings); 1387 } 1388 1389 /* Adjust walkers */ 1390 read_lock(&fib6_walker_lock); 1391 FOR_WALKERS(w) { 1392 if (w->state == FWS_C && w->leaf == rt) { 1393 RT6_TRACE("walker %p adjusted by delroute\n", w); 1394 w->leaf = rt->dst.rt6_next; 1395 if (!w->leaf) 1396 w->state = FWS_U; 1397 } 1398 } 1399 read_unlock(&fib6_walker_lock); 1400 1401 rt->dst.rt6_next = NULL; 1402 1403 /* If it was last route, expunge its radix tree node */ 1404 if (!fn->leaf) { 1405 fn->fn_flags &= ~RTN_RTINFO; 1406 net->ipv6.rt6_stats->fib_route_nodes--; 1407 fn = fib6_repair_tree(net, fn); 1408 } 1409 1410 fib6_purge_rt(rt, fn, net); 1411 1412 inet6_rt_notify(RTM_DELROUTE, rt, info); 1413 rt6_release(rt); 1414 } 1415 1416 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1417 { 1418 struct net *net = info->nl_net; 1419 struct fib6_node *fn = rt->rt6i_node; 1420 struct rt6_info **rtp; 1421 1422 #if RT6_DEBUG >= 2 1423 if (rt->dst.obsolete > 0) { 1424 WARN_ON(fn); 1425 return -ENOENT; 1426 } 1427 #endif 1428 if (!fn || rt == net->ipv6.ip6_null_entry) 1429 return -ENOENT; 1430 1431 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1432 1433 if (!(rt->rt6i_flags & RTF_CACHE)) { 1434 struct fib6_node *pn = fn; 1435 #ifdef CONFIG_IPV6_SUBTREES 1436 /* clones of this route might be in another subtree */ 1437 if (rt->rt6i_src.plen) { 1438 while (!(pn->fn_flags & RTN_ROOT)) 1439 pn = pn->parent; 1440 pn = pn->parent; 1441 } 1442 #endif 1443 fib6_prune_clones(info->nl_net, pn); 1444 } 1445 1446 /* 1447 * Walk the leaf entries looking for ourself 1448 */ 1449 1450 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1451 if (*rtp == rt) { 1452 fib6_del_route(fn, rtp, info); 1453 return 0; 1454 } 1455 } 1456 return -ENOENT; 1457 } 1458 1459 /* 1460 * Tree traversal function. 1461 * 1462 * Certainly, it is not interrupt safe. 1463 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1464 * It means, that we can modify tree during walking 1465 * and use this function for garbage collection, clone pruning, 1466 * cleaning tree when a device goes down etc. etc. 1467 * 1468 * It guarantees that every node will be traversed, 1469 * and that it will be traversed only once. 1470 * 1471 * Callback function w->func may return: 1472 * 0 -> continue walking. 1473 * positive value -> walking is suspended (used by tree dumps, 1474 * and probably by gc, if it will be split to several slices) 1475 * negative value -> terminate walking. 1476 * 1477 * The function itself returns: 1478 * 0 -> walk is complete. 1479 * >0 -> walk is incomplete (i.e. suspended) 1480 * <0 -> walk is terminated by an error. 1481 */ 1482 1483 static int fib6_walk_continue(struct fib6_walker *w) 1484 { 1485 struct fib6_node *fn, *pn; 1486 1487 for (;;) { 1488 fn = w->node; 1489 if (!fn) 1490 return 0; 1491 1492 if (w->prune && fn != w->root && 1493 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1494 w->state = FWS_C; 1495 w->leaf = fn->leaf; 1496 } 1497 switch (w->state) { 1498 #ifdef CONFIG_IPV6_SUBTREES 1499 case FWS_S: 1500 if (FIB6_SUBTREE(fn)) { 1501 w->node = FIB6_SUBTREE(fn); 1502 continue; 1503 } 1504 w->state = FWS_L; 1505 #endif 1506 case FWS_L: 1507 if (fn->left) { 1508 w->node = fn->left; 1509 w->state = FWS_INIT; 1510 continue; 1511 } 1512 w->state = FWS_R; 1513 case FWS_R: 1514 if (fn->right) { 1515 w->node = fn->right; 1516 w->state = FWS_INIT; 1517 continue; 1518 } 1519 w->state = FWS_C; 1520 w->leaf = fn->leaf; 1521 case FWS_C: 1522 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1523 int err; 1524 1525 if (w->skip) { 1526 w->skip--; 1527 goto skip; 1528 } 1529 1530 err = w->func(w); 1531 if (err) 1532 return err; 1533 1534 w->count++; 1535 continue; 1536 } 1537 skip: 1538 w->state = FWS_U; 1539 case FWS_U: 1540 if (fn == w->root) 1541 return 0; 1542 pn = fn->parent; 1543 w->node = pn; 1544 #ifdef CONFIG_IPV6_SUBTREES 1545 if (FIB6_SUBTREE(pn) == fn) { 1546 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1547 w->state = FWS_L; 1548 continue; 1549 } 1550 #endif 1551 if (pn->left == fn) { 1552 w->state = FWS_R; 1553 continue; 1554 } 1555 if (pn->right == fn) { 1556 w->state = FWS_C; 1557 w->leaf = w->node->leaf; 1558 continue; 1559 } 1560 #if RT6_DEBUG >= 2 1561 WARN_ON(1); 1562 #endif 1563 } 1564 } 1565 } 1566 1567 static int fib6_walk(struct fib6_walker *w) 1568 { 1569 int res; 1570 1571 w->state = FWS_INIT; 1572 w->node = w->root; 1573 1574 fib6_walker_link(w); 1575 res = fib6_walk_continue(w); 1576 if (res <= 0) 1577 fib6_walker_unlink(w); 1578 return res; 1579 } 1580 1581 static int fib6_clean_node(struct fib6_walker *w) 1582 { 1583 int res; 1584 struct rt6_info *rt; 1585 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1586 struct nl_info info = { 1587 .nl_net = c->net, 1588 }; 1589 1590 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1591 w->node->fn_sernum != c->sernum) 1592 w->node->fn_sernum = c->sernum; 1593 1594 if (!c->func) { 1595 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1596 w->leaf = NULL; 1597 return 0; 1598 } 1599 1600 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1601 res = c->func(rt, c->arg); 1602 if (res < 0) { 1603 w->leaf = rt; 1604 res = fib6_del(rt, &info); 1605 if (res) { 1606 #if RT6_DEBUG >= 2 1607 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1608 __func__, rt, rt->rt6i_node, res); 1609 #endif 1610 continue; 1611 } 1612 return 0; 1613 } 1614 WARN_ON(res != 0); 1615 } 1616 w->leaf = rt; 1617 return 0; 1618 } 1619 1620 /* 1621 * Convenient frontend to tree walker. 1622 * 1623 * func is called on each route. 1624 * It may return -1 -> delete this route. 1625 * 0 -> continue walking 1626 * 1627 * prune==1 -> only immediate children of node (certainly, 1628 * ignoring pure split nodes) will be scanned. 1629 */ 1630 1631 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1632 int (*func)(struct rt6_info *, void *arg), 1633 bool prune, int sernum, void *arg) 1634 { 1635 struct fib6_cleaner c; 1636 1637 c.w.root = root; 1638 c.w.func = fib6_clean_node; 1639 c.w.prune = prune; 1640 c.w.count = 0; 1641 c.w.skip = 0; 1642 c.func = func; 1643 c.sernum = sernum; 1644 c.arg = arg; 1645 c.net = net; 1646 1647 fib6_walk(&c.w); 1648 } 1649 1650 static void __fib6_clean_all(struct net *net, 1651 int (*func)(struct rt6_info *, void *), 1652 int sernum, void *arg) 1653 { 1654 struct fib6_table *table; 1655 struct hlist_head *head; 1656 unsigned int h; 1657 1658 rcu_read_lock(); 1659 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1660 head = &net->ipv6.fib_table_hash[h]; 1661 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1662 write_lock_bh(&table->tb6_lock); 1663 fib6_clean_tree(net, &table->tb6_root, 1664 func, false, sernum, arg); 1665 write_unlock_bh(&table->tb6_lock); 1666 } 1667 } 1668 rcu_read_unlock(); 1669 } 1670 1671 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1672 void *arg) 1673 { 1674 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1675 } 1676 1677 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1678 { 1679 if (rt->rt6i_flags & RTF_CACHE) { 1680 RT6_TRACE("pruning clone %p\n", rt); 1681 return -1; 1682 } 1683 1684 return 0; 1685 } 1686 1687 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1688 { 1689 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1690 FIB6_NO_SERNUM_CHANGE, NULL); 1691 } 1692 1693 static void fib6_flush_trees(struct net *net) 1694 { 1695 int new_sernum = fib6_new_sernum(net); 1696 1697 __fib6_clean_all(net, NULL, new_sernum, NULL); 1698 } 1699 1700 /* 1701 * Garbage collection 1702 */ 1703 1704 static struct fib6_gc_args 1705 { 1706 int timeout; 1707 int more; 1708 } gc_args; 1709 1710 static int fib6_age(struct rt6_info *rt, void *arg) 1711 { 1712 unsigned long now = jiffies; 1713 1714 /* 1715 * check addrconf expiration here. 1716 * Routes are expired even if they are in use. 1717 * 1718 * Also age clones. Note, that clones are aged out 1719 * only if they are not in use now. 1720 */ 1721 1722 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1723 if (time_after(now, rt->dst.expires)) { 1724 RT6_TRACE("expiring %p\n", rt); 1725 return -1; 1726 } 1727 gc_args.more++; 1728 } else if (rt->rt6i_flags & RTF_CACHE) { 1729 if (atomic_read(&rt->dst.__refcnt) == 0 && 1730 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1731 RT6_TRACE("aging clone %p\n", rt); 1732 return -1; 1733 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1734 struct neighbour *neigh; 1735 __u8 neigh_flags = 0; 1736 1737 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1738 if (neigh) { 1739 neigh_flags = neigh->flags; 1740 neigh_release(neigh); 1741 } 1742 if (!(neigh_flags & NTF_ROUTER)) { 1743 RT6_TRACE("purging route %p via non-router but gateway\n", 1744 rt); 1745 return -1; 1746 } 1747 } 1748 gc_args.more++; 1749 } 1750 1751 return 0; 1752 } 1753 1754 static DEFINE_SPINLOCK(fib6_gc_lock); 1755 1756 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1757 { 1758 unsigned long now; 1759 1760 if (force) { 1761 spin_lock_bh(&fib6_gc_lock); 1762 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1763 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1764 return; 1765 } 1766 gc_args.timeout = expires ? (int)expires : 1767 net->ipv6.sysctl.ip6_rt_gc_interval; 1768 1769 gc_args.more = icmp6_dst_gc(); 1770 1771 fib6_clean_all(net, fib6_age, NULL); 1772 now = jiffies; 1773 net->ipv6.ip6_rt_last_gc = now; 1774 1775 if (gc_args.more) 1776 mod_timer(&net->ipv6.ip6_fib_timer, 1777 round_jiffies(now 1778 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1779 else 1780 del_timer(&net->ipv6.ip6_fib_timer); 1781 spin_unlock_bh(&fib6_gc_lock); 1782 } 1783 1784 static void fib6_gc_timer_cb(unsigned long arg) 1785 { 1786 fib6_run_gc(0, (struct net *)arg, true); 1787 } 1788 1789 static int __net_init fib6_net_init(struct net *net) 1790 { 1791 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1792 1793 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1794 1795 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1796 if (!net->ipv6.rt6_stats) 1797 goto out_timer; 1798 1799 /* Avoid false sharing : Use at least a full cache line */ 1800 size = max_t(size_t, size, L1_CACHE_BYTES); 1801 1802 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1803 if (!net->ipv6.fib_table_hash) 1804 goto out_rt6_stats; 1805 1806 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1807 GFP_KERNEL); 1808 if (!net->ipv6.fib6_main_tbl) 1809 goto out_fib_table_hash; 1810 1811 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1812 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1813 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1814 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1815 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1816 1817 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1818 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1819 GFP_KERNEL); 1820 if (!net->ipv6.fib6_local_tbl) 1821 goto out_fib6_main_tbl; 1822 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1823 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1824 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1825 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1826 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1827 #endif 1828 fib6_tables_init(net); 1829 1830 return 0; 1831 1832 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1833 out_fib6_main_tbl: 1834 kfree(net->ipv6.fib6_main_tbl); 1835 #endif 1836 out_fib_table_hash: 1837 kfree(net->ipv6.fib_table_hash); 1838 out_rt6_stats: 1839 kfree(net->ipv6.rt6_stats); 1840 out_timer: 1841 return -ENOMEM; 1842 } 1843 1844 static void fib6_net_exit(struct net *net) 1845 { 1846 rt6_ifdown(net, NULL); 1847 del_timer_sync(&net->ipv6.ip6_fib_timer); 1848 1849 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1850 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1851 kfree(net->ipv6.fib6_local_tbl); 1852 #endif 1853 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1854 kfree(net->ipv6.fib6_main_tbl); 1855 kfree(net->ipv6.fib_table_hash); 1856 kfree(net->ipv6.rt6_stats); 1857 } 1858 1859 static struct pernet_operations fib6_net_ops = { 1860 .init = fib6_net_init, 1861 .exit = fib6_net_exit, 1862 }; 1863 1864 int __init fib6_init(void) 1865 { 1866 int ret = -ENOMEM; 1867 1868 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1869 sizeof(struct fib6_node), 1870 0, SLAB_HWCACHE_ALIGN, 1871 NULL); 1872 if (!fib6_node_kmem) 1873 goto out; 1874 1875 ret = register_pernet_subsys(&fib6_net_ops); 1876 if (ret) 1877 goto out_kmem_cache_create; 1878 1879 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1880 NULL); 1881 if (ret) 1882 goto out_unregister_subsys; 1883 1884 __fib6_flush_trees = fib6_flush_trees; 1885 out: 1886 return ret; 1887 1888 out_unregister_subsys: 1889 unregister_pernet_subsys(&fib6_net_ops); 1890 out_kmem_cache_create: 1891 kmem_cache_destroy(fib6_node_kmem); 1892 goto out; 1893 } 1894 1895 void fib6_gc_cleanup(void) 1896 { 1897 unregister_pernet_subsys(&fib6_net_ops); 1898 kmem_cache_destroy(fib6_node_kmem); 1899 } 1900 1901 #ifdef CONFIG_PROC_FS 1902 1903 struct ipv6_route_iter { 1904 struct seq_net_private p; 1905 struct fib6_walker w; 1906 loff_t skip; 1907 struct fib6_table *tbl; 1908 int sernum; 1909 }; 1910 1911 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1912 { 1913 struct rt6_info *rt = v; 1914 struct ipv6_route_iter *iter = seq->private; 1915 1916 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1917 1918 #ifdef CONFIG_IPV6_SUBTREES 1919 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1920 #else 1921 seq_puts(seq, "00000000000000000000000000000000 00 "); 1922 #endif 1923 if (rt->rt6i_flags & RTF_GATEWAY) 1924 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1925 else 1926 seq_puts(seq, "00000000000000000000000000000000"); 1927 1928 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1929 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1930 rt->dst.__use, rt->rt6i_flags, 1931 rt->dst.dev ? rt->dst.dev->name : ""); 1932 iter->w.leaf = NULL; 1933 return 0; 1934 } 1935 1936 static int ipv6_route_yield(struct fib6_walker *w) 1937 { 1938 struct ipv6_route_iter *iter = w->args; 1939 1940 if (!iter->skip) 1941 return 1; 1942 1943 do { 1944 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1945 iter->skip--; 1946 if (!iter->skip && iter->w.leaf) 1947 return 1; 1948 } while (iter->w.leaf); 1949 1950 return 0; 1951 } 1952 1953 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1954 { 1955 memset(&iter->w, 0, sizeof(iter->w)); 1956 iter->w.func = ipv6_route_yield; 1957 iter->w.root = &iter->tbl->tb6_root; 1958 iter->w.state = FWS_INIT; 1959 iter->w.node = iter->w.root; 1960 iter->w.args = iter; 1961 iter->sernum = iter->w.root->fn_sernum; 1962 INIT_LIST_HEAD(&iter->w.lh); 1963 fib6_walker_link(&iter->w); 1964 } 1965 1966 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1967 struct net *net) 1968 { 1969 unsigned int h; 1970 struct hlist_node *node; 1971 1972 if (tbl) { 1973 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1974 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1975 } else { 1976 h = 0; 1977 node = NULL; 1978 } 1979 1980 while (!node && h < FIB6_TABLE_HASHSZ) { 1981 node = rcu_dereference_bh( 1982 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 1983 } 1984 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 1985 } 1986 1987 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 1988 { 1989 if (iter->sernum != iter->w.root->fn_sernum) { 1990 iter->sernum = iter->w.root->fn_sernum; 1991 iter->w.state = FWS_INIT; 1992 iter->w.node = iter->w.root; 1993 WARN_ON(iter->w.skip); 1994 iter->w.skip = iter->w.count; 1995 } 1996 } 1997 1998 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1999 { 2000 int r; 2001 struct rt6_info *n; 2002 struct net *net = seq_file_net(seq); 2003 struct ipv6_route_iter *iter = seq->private; 2004 2005 if (!v) 2006 goto iter_table; 2007 2008 n = ((struct rt6_info *)v)->dst.rt6_next; 2009 if (n) { 2010 ++*pos; 2011 return n; 2012 } 2013 2014 iter_table: 2015 ipv6_route_check_sernum(iter); 2016 read_lock(&iter->tbl->tb6_lock); 2017 r = fib6_walk_continue(&iter->w); 2018 read_unlock(&iter->tbl->tb6_lock); 2019 if (r > 0) { 2020 if (v) 2021 ++*pos; 2022 return iter->w.leaf; 2023 } else if (r < 0) { 2024 fib6_walker_unlink(&iter->w); 2025 return NULL; 2026 } 2027 fib6_walker_unlink(&iter->w); 2028 2029 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2030 if (!iter->tbl) 2031 return NULL; 2032 2033 ipv6_route_seq_setup_walk(iter); 2034 goto iter_table; 2035 } 2036 2037 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2038 __acquires(RCU_BH) 2039 { 2040 struct net *net = seq_file_net(seq); 2041 struct ipv6_route_iter *iter = seq->private; 2042 2043 rcu_read_lock_bh(); 2044 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2045 iter->skip = *pos; 2046 2047 if (iter->tbl) { 2048 ipv6_route_seq_setup_walk(iter); 2049 return ipv6_route_seq_next(seq, NULL, pos); 2050 } else { 2051 return NULL; 2052 } 2053 } 2054 2055 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2056 { 2057 struct fib6_walker *w = &iter->w; 2058 return w->node && !(w->state == FWS_U && w->node == w->root); 2059 } 2060 2061 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2062 __releases(RCU_BH) 2063 { 2064 struct ipv6_route_iter *iter = seq->private; 2065 2066 if (ipv6_route_iter_active(iter)) 2067 fib6_walker_unlink(&iter->w); 2068 2069 rcu_read_unlock_bh(); 2070 } 2071 2072 static const struct seq_operations ipv6_route_seq_ops = { 2073 .start = ipv6_route_seq_start, 2074 .next = ipv6_route_seq_next, 2075 .stop = ipv6_route_seq_stop, 2076 .show = ipv6_route_seq_show 2077 }; 2078 2079 int ipv6_route_open(struct inode *inode, struct file *file) 2080 { 2081 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2082 sizeof(struct ipv6_route_iter)); 2083 } 2084 2085 #endif /* CONFIG_PROC_FS */ 2086