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