1/* 2 * Linux INET6 implementation 3 * Forwarding Information Database 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * Changes: 14 * Yuji SEKIYA @USAGI: Support default route on router node; 15 * remove ip6_null_entry from the top of 16 * routing table. 17 * Ville Nuorvala: Fixed routing subtrees. 18 */ 19 20#define pr_fmt(fmt) "IPv6: " fmt 21 22#include <linux/errno.h> 23#include <linux/types.h> 24#include <linux/net.h> 25#include <linux/route.h> 26#include <linux/netdevice.h> 27#include <linux/in6.h> 28#include <linux/init.h> 29#include <linux/list.h> 30#include <linux/slab.h> 31 32#include <net/ipv6.h> 33#include <net/ndisc.h> 34#include <net/addrconf.h> 35#include <net/lwtunnel.h> 36 37#include <net/ip6_fib.h> 38#include <net/ip6_route.h> 39 40#define RT6_DEBUG 2 41 42#if RT6_DEBUG >= 3 43#define RT6_TRACE(x...) pr_debug(x) 44#else 45#define RT6_TRACE(x...) do { ; } while (0) 46#endif 47 48static struct kmem_cache *fib6_node_kmem __read_mostly; 49 50struct fib6_cleaner { 51 struct fib6_walker w; 52 struct net *net; 53 int (*func)(struct rt6_info *, void *arg); 54 int sernum; 55 void *arg; 56}; 57 58static DEFINE_RWLOCK(fib6_walker_lock); 59 60#ifdef CONFIG_IPV6_SUBTREES 61#define FWS_INIT FWS_S 62#else 63#define FWS_INIT FWS_L 64#endif 65 66static void fib6_prune_clones(struct net *net, struct fib6_node *fn); 67static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 68static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 69static int fib6_walk(struct fib6_walker *w); 70static int fib6_walk_continue(struct fib6_walker *w); 71 72/* 73 * A routing update causes an increase of the serial number on the 74 * affected subtree. This allows for cached routes to be asynchronously 75 * tested when modifications are made to the destination cache as a 76 * result of redirects, path MTU changes, etc. 77 */ 78 79static void fib6_gc_timer_cb(unsigned long arg); 80 81static LIST_HEAD(fib6_walkers); 82#define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh) 83 84static void fib6_walker_link(struct fib6_walker *w) 85{ 86 write_lock_bh(&fib6_walker_lock); 87 list_add(&w->lh, &fib6_walkers); 88 write_unlock_bh(&fib6_walker_lock); 89} 90 91static void fib6_walker_unlink(struct fib6_walker *w) 92{ 93 write_lock_bh(&fib6_walker_lock); 94 list_del(&w->lh); 95 write_unlock_bh(&fib6_walker_lock); 96} 97 98static int fib6_new_sernum(struct net *net) 99{ 100 int new, old; 101 102 do { 103 old = atomic_read(&net->ipv6.fib6_sernum); 104 new = old < INT_MAX ? old + 1 : 1; 105 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 106 old, new) != old); 107 return new; 108} 109 110enum { 111 FIB6_NO_SERNUM_CHANGE = 0, 112}; 113 114/* 115 * Auxiliary address test functions for the radix tree. 116 * 117 * These assume a 32bit processor (although it will work on 118 * 64bit processors) 119 */ 120 121/* 122 * test bit 123 */ 124#if defined(__LITTLE_ENDIAN) 125# define BITOP_BE32_SWIZZLE (0x1F & ~7) 126#else 127# define BITOP_BE32_SWIZZLE 0 128#endif 129 130static __be32 addr_bit_set(const void *token, int fn_bit) 131{ 132 const __be32 *addr = token; 133 /* 134 * Here, 135 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 136 * is optimized version of 137 * htonl(1 << ((~fn_bit)&0x1F)) 138 * See include/asm-generic/bitops/le.h. 139 */ 140 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 141 addr[fn_bit >> 5]; 142} 143 144static struct fib6_node *node_alloc(void) 145{ 146 struct fib6_node *fn; 147 148 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 149 150 return fn; 151} 152 153static void node_free(struct fib6_node *fn) 154{ 155 kmem_cache_free(fib6_node_kmem, fn); 156} 157 158static void rt6_rcu_free(struct rt6_info *rt) 159{ 160 call_rcu(&rt->dst.rcu_head, dst_rcu_free); 161} 162 163static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) 164{ 165 int cpu; 166 167 if (!non_pcpu_rt->rt6i_pcpu) 168 return; 169 170 for_each_possible_cpu(cpu) { 171 struct rt6_info **ppcpu_rt; 172 struct rt6_info *pcpu_rt; 173 174 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 175 pcpu_rt = *ppcpu_rt; 176 if (pcpu_rt) { 177 rt6_rcu_free(pcpu_rt); 178 *ppcpu_rt = NULL; 179 } 180 } 181 182 non_pcpu_rt->rt6i_pcpu = NULL; 183} 184 185static void rt6_release(struct rt6_info *rt) 186{ 187 if (atomic_dec_and_test(&rt->rt6i_ref)) { 188 rt6_free_pcpu(rt); 189 rt6_rcu_free(rt); 190 } 191} 192 193static void fib6_link_table(struct net *net, struct fib6_table *tb) 194{ 195 unsigned int h; 196 197 /* 198 * Initialize table lock at a single place to give lockdep a key, 199 * tables aren't visible prior to being linked to the list. 200 */ 201 rwlock_init(&tb->tb6_lock); 202 203 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 204 205 /* 206 * No protection necessary, this is the only list mutatation 207 * operation, tables never disappear once they exist. 208 */ 209 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 210} 211 212#ifdef CONFIG_IPV6_MULTIPLE_TABLES 213 214static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 215{ 216 struct fib6_table *table; 217 218 table = kzalloc(sizeof(*table), GFP_ATOMIC); 219 if (table) { 220 table->tb6_id = id; 221 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 222 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 223 inet_peer_base_init(&table->tb6_peers); 224 } 225 226 return table; 227} 228 229struct fib6_table *fib6_new_table(struct net *net, u32 id) 230{ 231 struct fib6_table *tb; 232 233 if (id == 0) 234 id = RT6_TABLE_MAIN; 235 tb = fib6_get_table(net, id); 236 if (tb) 237 return tb; 238 239 tb = fib6_alloc_table(net, id); 240 if (tb) 241 fib6_link_table(net, tb); 242 243 return tb; 244} 245 246struct fib6_table *fib6_get_table(struct net *net, u32 id) 247{ 248 struct fib6_table *tb; 249 struct hlist_head *head; 250 unsigned int h; 251 252 if (id == 0) 253 id = RT6_TABLE_MAIN; 254 h = id & (FIB6_TABLE_HASHSZ - 1); 255 rcu_read_lock(); 256 head = &net->ipv6.fib_table_hash[h]; 257 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 258 if (tb->tb6_id == id) { 259 rcu_read_unlock(); 260 return tb; 261 } 262 } 263 rcu_read_unlock(); 264 265 return NULL; 266} 267EXPORT_SYMBOL_GPL(fib6_get_table); 268 269static void __net_init fib6_tables_init(struct net *net) 270{ 271 fib6_link_table(net, net->ipv6.fib6_main_tbl); 272 fib6_link_table(net, net->ipv6.fib6_local_tbl); 273} 274#else 275 276struct fib6_table *fib6_new_table(struct net *net, u32 id) 277{ 278 return fib6_get_table(net, id); 279} 280 281struct fib6_table *fib6_get_table(struct net *net, u32 id) 282{ 283 return net->ipv6.fib6_main_tbl; 284} 285 286struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 287 int flags, pol_lookup_t lookup) 288{ 289 struct rt6_info *rt; 290 291 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 292 if (rt->rt6i_flags & RTF_REJECT && 293 rt->dst.error == -EAGAIN) { 294 ip6_rt_put(rt); 295 rt = net->ipv6.ip6_null_entry; 296 dst_hold(&rt->dst); 297 } 298 299 return &rt->dst; 300} 301 302static void __net_init fib6_tables_init(struct net *net) 303{ 304 fib6_link_table(net, net->ipv6.fib6_main_tbl); 305} 306 307#endif 308 309static int fib6_dump_node(struct fib6_walker *w) 310{ 311 int res; 312 struct rt6_info *rt; 313 314 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 315 res = rt6_dump_route(rt, w->args); 316 if (res < 0) { 317 /* Frame is full, suspend walking */ 318 w->leaf = rt; 319 return 1; 320 } 321 } 322 w->leaf = NULL; 323 return 0; 324} 325 326static void fib6_dump_end(struct netlink_callback *cb) 327{ 328 struct fib6_walker *w = (void *)cb->args[2]; 329 330 if (w) { 331 if (cb->args[4]) { 332 cb->args[4] = 0; 333 fib6_walker_unlink(w); 334 } 335 cb->args[2] = 0; 336 kfree(w); 337 } 338 cb->done = (void *)cb->args[3]; 339 cb->args[1] = 3; 340} 341 342static int fib6_dump_done(struct netlink_callback *cb) 343{ 344 fib6_dump_end(cb); 345 return cb->done ? cb->done(cb) : 0; 346} 347 348static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 349 struct netlink_callback *cb) 350{ 351 struct fib6_walker *w; 352 int res; 353 354 w = (void *)cb->args[2]; 355 w->root = &table->tb6_root; 356 357 if (cb->args[4] == 0) { 358 w->count = 0; 359 w->skip = 0; 360 361 read_lock_bh(&table->tb6_lock); 362 res = fib6_walk(w); 363 read_unlock_bh(&table->tb6_lock); 364 if (res > 0) { 365 cb->args[4] = 1; 366 cb->args[5] = w->root->fn_sernum; 367 } 368 } else { 369 if (cb->args[5] != w->root->fn_sernum) { 370 /* Begin at the root if the tree changed */ 371 cb->args[5] = w->root->fn_sernum; 372 w->state = FWS_INIT; 373 w->node = w->root; 374 w->skip = w->count; 375 } else 376 w->skip = 0; 377 378 read_lock_bh(&table->tb6_lock); 379 res = fib6_walk_continue(w); 380 read_unlock_bh(&table->tb6_lock); 381 if (res <= 0) { 382 fib6_walker_unlink(w); 383 cb->args[4] = 0; 384 } 385 } 386 387 return res; 388} 389 390static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 391{ 392 struct net *net = sock_net(skb->sk); 393 unsigned int h, s_h; 394 unsigned int e = 0, s_e; 395 struct rt6_rtnl_dump_arg arg; 396 struct fib6_walker *w; 397 struct fib6_table *tb; 398 struct hlist_head *head; 399 int res = 0; 400 401 s_h = cb->args[0]; 402 s_e = cb->args[1]; 403 404 w = (void *)cb->args[2]; 405 if (!w) { 406 /* New dump: 407 * 408 * 1. hook callback destructor. 409 */ 410 cb->args[3] = (long)cb->done; 411 cb->done = fib6_dump_done; 412 413 /* 414 * 2. allocate and initialize walker. 415 */ 416 w = kzalloc(sizeof(*w), GFP_ATOMIC); 417 if (!w) 418 return -ENOMEM; 419 w->func = fib6_dump_node; 420 cb->args[2] = (long)w; 421 } 422 423 arg.skb = skb; 424 arg.cb = cb; 425 arg.net = net; 426 w->args = &arg; 427 428 rcu_read_lock(); 429 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 430 e = 0; 431 head = &net->ipv6.fib_table_hash[h]; 432 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 433 if (e < s_e) 434 goto next; 435 res = fib6_dump_table(tb, skb, cb); 436 if (res != 0) 437 goto out; 438next: 439 e++; 440 } 441 } 442out: 443 rcu_read_unlock(); 444 cb->args[1] = e; 445 cb->args[0] = h; 446 447 res = res < 0 ? res : skb->len; 448 if (res <= 0) 449 fib6_dump_end(cb); 450 return res; 451} 452 453/* 454 * Routing Table 455 * 456 * return the appropriate node for a routing tree "add" operation 457 * by either creating and inserting or by returning an existing 458 * node. 459 */ 460 461static struct fib6_node *fib6_add_1(struct fib6_node *root, 462 struct in6_addr *addr, int plen, 463 int offset, int allow_create, 464 int replace_required, int sernum) 465{ 466 struct fib6_node *fn, *in, *ln; 467 struct fib6_node *pn = NULL; 468 struct rt6key *key; 469 int bit; 470 __be32 dir = 0; 471 472 RT6_TRACE("fib6_add_1\n"); 473 474 /* insert node in tree */ 475 476 fn = root; 477 478 do { 479 key = (struct rt6key *)((u8 *)fn->leaf + offset); 480 481 /* 482 * Prefix match 483 */ 484 if (plen < fn->fn_bit || 485 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 486 if (!allow_create) { 487 if (replace_required) { 488 pr_warn("Can't replace route, no match found\n"); 489 return ERR_PTR(-ENOENT); 490 } 491 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 492 } 493 goto insert_above; 494 } 495 496 /* 497 * Exact match ? 498 */ 499 500 if (plen == fn->fn_bit) { 501 /* clean up an intermediate node */ 502 if (!(fn->fn_flags & RTN_RTINFO)) { 503 rt6_release(fn->leaf); 504 fn->leaf = NULL; 505 } 506 507 fn->fn_sernum = sernum; 508 509 return fn; 510 } 511 512 /* 513 * We have more bits to go 514 */ 515 516 /* Try to walk down on tree. */ 517 fn->fn_sernum = sernum; 518 dir = addr_bit_set(addr, fn->fn_bit); 519 pn = fn; 520 fn = dir ? fn->right : fn->left; 521 } while (fn); 522 523 if (!allow_create) { 524 /* We should not create new node because 525 * NLM_F_REPLACE was specified without NLM_F_CREATE 526 * I assume it is safe to require NLM_F_CREATE when 527 * REPLACE flag is used! Later we may want to remove the 528 * check for replace_required, because according 529 * to netlink specification, NLM_F_CREATE 530 * MUST be specified if new route is created. 531 * That would keep IPv6 consistent with IPv4 532 */ 533 if (replace_required) { 534 pr_warn("Can't replace route, no match found\n"); 535 return ERR_PTR(-ENOENT); 536 } 537 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 538 } 539 /* 540 * We walked to the bottom of tree. 541 * Create new leaf node without children. 542 */ 543 544 ln = node_alloc(); 545 546 if (!ln) 547 return ERR_PTR(-ENOMEM); 548 ln->fn_bit = plen; 549 550 ln->parent = pn; 551 ln->fn_sernum = sernum; 552 553 if (dir) 554 pn->right = ln; 555 else 556 pn->left = ln; 557 558 return ln; 559 560 561insert_above: 562 /* 563 * split since we don't have a common prefix anymore or 564 * we have a less significant route. 565 * we've to insert an intermediate node on the list 566 * this new node will point to the one we need to create 567 * and the current 568 */ 569 570 pn = fn->parent; 571 572 /* find 1st bit in difference between the 2 addrs. 573 574 See comment in __ipv6_addr_diff: bit may be an invalid value, 575 but if it is >= plen, the value is ignored in any case. 576 */ 577 578 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 579 580 /* 581 * (intermediate)[in] 582 * / \ 583 * (new leaf node)[ln] (old node)[fn] 584 */ 585 if (plen > bit) { 586 in = node_alloc(); 587 ln = node_alloc(); 588 589 if (!in || !ln) { 590 if (in) 591 node_free(in); 592 if (ln) 593 node_free(ln); 594 return ERR_PTR(-ENOMEM); 595 } 596 597 /* 598 * new intermediate node. 599 * RTN_RTINFO will 600 * be off since that an address that chooses one of 601 * the branches would not match less specific routes 602 * in the other branch 603 */ 604 605 in->fn_bit = bit; 606 607 in->parent = pn; 608 in->leaf = fn->leaf; 609 atomic_inc(&in->leaf->rt6i_ref); 610 611 in->fn_sernum = sernum; 612 613 /* update parent pointer */ 614 if (dir) 615 pn->right = in; 616 else 617 pn->left = in; 618 619 ln->fn_bit = plen; 620 621 ln->parent = in; 622 fn->parent = in; 623 624 ln->fn_sernum = sernum; 625 626 if (addr_bit_set(addr, bit)) { 627 in->right = ln; 628 in->left = fn; 629 } else { 630 in->left = ln; 631 in->right = fn; 632 } 633 } else { /* plen <= bit */ 634 635 /* 636 * (new leaf node)[ln] 637 * / \ 638 * (old node)[fn] NULL 639 */ 640 641 ln = node_alloc(); 642 643 if (!ln) 644 return ERR_PTR(-ENOMEM); 645 646 ln->fn_bit = plen; 647 648 ln->parent = pn; 649 650 ln->fn_sernum = sernum; 651 652 if (dir) 653 pn->right = ln; 654 else 655 pn->left = ln; 656 657 if (addr_bit_set(&key->addr, plen)) 658 ln->right = fn; 659 else 660 ln->left = fn; 661 662 fn->parent = ln; 663 } 664 return ln; 665} 666 667static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 668{ 669 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 670 RTF_GATEWAY; 671} 672 673static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 674{ 675 int i; 676 677 for (i = 0; i < RTAX_MAX; i++) { 678 if (test_bit(i, mxc->mx_valid)) 679 mp[i] = mxc->mx[i]; 680 } 681} 682 683static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 684{ 685 if (!mxc->mx) 686 return 0; 687 688 if (dst->flags & DST_HOST) { 689 u32 *mp = dst_metrics_write_ptr(dst); 690 691 if (unlikely(!mp)) 692 return -ENOMEM; 693 694 fib6_copy_metrics(mp, mxc); 695 } else { 696 dst_init_metrics(dst, mxc->mx, false); 697 698 /* We've stolen mx now. */ 699 mxc->mx = NULL; 700 } 701 702 return 0; 703} 704 705static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 706 struct net *net) 707{ 708 if (atomic_read(&rt->rt6i_ref) != 1) { 709 /* This route is used as dummy address holder in some split 710 * nodes. It is not leaked, but it still holds other resources, 711 * which must be released in time. So, scan ascendant nodes 712 * and replace dummy references to this route with references 713 * to still alive ones. 714 */ 715 while (fn) { 716 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 717 fn->leaf = fib6_find_prefix(net, fn); 718 atomic_inc(&fn->leaf->rt6i_ref); 719 rt6_release(rt); 720 } 721 fn = fn->parent; 722 } 723 /* No more references are possible at this point. */ 724 BUG_ON(atomic_read(&rt->rt6i_ref) != 1); 725 } 726} 727 728/* 729 * Insert routing information in a node. 730 */ 731 732static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 733 struct nl_info *info, struct mx6_config *mxc) 734{ 735 struct rt6_info *iter = NULL; 736 struct rt6_info **ins; 737 struct rt6_info **fallback_ins = NULL; 738 int replace = (info->nlh && 739 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 740 int add = (!info->nlh || 741 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 742 int found = 0; 743 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 744 int err; 745 746 ins = &fn->leaf; 747 748 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 749 /* 750 * Search for duplicates 751 */ 752 753 if (iter->rt6i_metric == rt->rt6i_metric) { 754 /* 755 * Same priority level 756 */ 757 if (info->nlh && 758 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 759 return -EEXIST; 760 if (replace) { 761 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 762 found++; 763 break; 764 } 765 if (rt_can_ecmp) 766 fallback_ins = fallback_ins ?: ins; 767 goto next_iter; 768 } 769 770 if (iter->dst.dev == rt->dst.dev && 771 iter->rt6i_idev == rt->rt6i_idev && 772 ipv6_addr_equal(&iter->rt6i_gateway, 773 &rt->rt6i_gateway)) { 774 if (rt->rt6i_nsiblings) 775 rt->rt6i_nsiblings = 0; 776 if (!(iter->rt6i_flags & RTF_EXPIRES)) 777 return -EEXIST; 778 if (!(rt->rt6i_flags & RTF_EXPIRES)) 779 rt6_clean_expires(iter); 780 else 781 rt6_set_expires(iter, rt->dst.expires); 782 iter->rt6i_pmtu = rt->rt6i_pmtu; 783 return -EEXIST; 784 } 785 /* If we have the same destination and the same metric, 786 * but not the same gateway, then the route we try to 787 * add is sibling to this route, increment our counter 788 * of siblings, and later we will add our route to the 789 * list. 790 * Only static routes (which don't have flag 791 * RTF_EXPIRES) are used for ECMPv6. 792 * 793 * To avoid long list, we only had siblings if the 794 * route have a gateway. 795 */ 796 if (rt_can_ecmp && 797 rt6_qualify_for_ecmp(iter)) 798 rt->rt6i_nsiblings++; 799 } 800 801 if (iter->rt6i_metric > rt->rt6i_metric) 802 break; 803 804next_iter: 805 ins = &iter->dst.rt6_next; 806 } 807 808 if (fallback_ins && !found) { 809 /* No ECMP-able route found, replace first non-ECMP one */ 810 ins = fallback_ins; 811 iter = *ins; 812 found++; 813 } 814 815 /* Reset round-robin state, if necessary */ 816 if (ins == &fn->leaf) 817 fn->rr_ptr = NULL; 818 819 /* Link this route to others same route. */ 820 if (rt->rt6i_nsiblings) { 821 unsigned int rt6i_nsiblings; 822 struct rt6_info *sibling, *temp_sibling; 823 824 /* Find the first route that have the same metric */ 825 sibling = fn->leaf; 826 while (sibling) { 827 if (sibling->rt6i_metric == rt->rt6i_metric && 828 rt6_qualify_for_ecmp(sibling)) { 829 list_add_tail(&rt->rt6i_siblings, 830 &sibling->rt6i_siblings); 831 break; 832 } 833 sibling = sibling->dst.rt6_next; 834 } 835 /* For each sibling in the list, increment the counter of 836 * siblings. BUG() if counters does not match, list of siblings 837 * is broken! 838 */ 839 rt6i_nsiblings = 0; 840 list_for_each_entry_safe(sibling, temp_sibling, 841 &rt->rt6i_siblings, rt6i_siblings) { 842 sibling->rt6i_nsiblings++; 843 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 844 rt6i_nsiblings++; 845 } 846 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 847 } 848 849 /* 850 * insert node 851 */ 852 if (!replace) { 853 if (!add) 854 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 855 856add: 857 err = fib6_commit_metrics(&rt->dst, mxc); 858 if (err) 859 return err; 860 861 rt->dst.rt6_next = iter; 862 *ins = rt; 863 rt->rt6i_node = fn; 864 atomic_inc(&rt->rt6i_ref); 865 inet6_rt_notify(RTM_NEWROUTE, rt, info, 0); 866 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 867 868 if (!(fn->fn_flags & RTN_RTINFO)) { 869 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 870 fn->fn_flags |= RTN_RTINFO; 871 } 872 873 } else { 874 int nsiblings; 875 876 if (!found) { 877 if (add) 878 goto add; 879 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 880 return -ENOENT; 881 } 882 883 err = fib6_commit_metrics(&rt->dst, mxc); 884 if (err) 885 return err; 886 887 *ins = rt; 888 rt->rt6i_node = fn; 889 rt->dst.rt6_next = iter->dst.rt6_next; 890 atomic_inc(&rt->rt6i_ref); 891 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 892 if (!(fn->fn_flags & RTN_RTINFO)) { 893 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 894 fn->fn_flags |= RTN_RTINFO; 895 } 896 nsiblings = iter->rt6i_nsiblings; 897 fib6_purge_rt(iter, fn, info->nl_net); 898 rt6_release(iter); 899 900 if (nsiblings) { 901 /* Replacing an ECMP route, remove all siblings */ 902 ins = &rt->dst.rt6_next; 903 iter = *ins; 904 while (iter) { 905 if (rt6_qualify_for_ecmp(iter)) { 906 *ins = iter->dst.rt6_next; 907 fib6_purge_rt(iter, fn, info->nl_net); 908 rt6_release(iter); 909 nsiblings--; 910 } else { 911 ins = &iter->dst.rt6_next; 912 } 913 iter = *ins; 914 } 915 WARN_ON(nsiblings != 0); 916 } 917 } 918 919 return 0; 920} 921 922static void fib6_start_gc(struct net *net, struct rt6_info *rt) 923{ 924 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 925 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 926 mod_timer(&net->ipv6.ip6_fib_timer, 927 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 928} 929 930void fib6_force_start_gc(struct net *net) 931{ 932 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 933 mod_timer(&net->ipv6.ip6_fib_timer, 934 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 935} 936 937/* 938 * Add routing information to the routing tree. 939 * <destination addr>/<source addr> 940 * with source addr info in sub-trees 941 */ 942 943int fib6_add(struct fib6_node *root, struct rt6_info *rt, 944 struct nl_info *info, struct mx6_config *mxc) 945{ 946 struct fib6_node *fn, *pn = NULL; 947 int err = -ENOMEM; 948 int allow_create = 1; 949 int replace_required = 0; 950 int sernum = fib6_new_sernum(info->nl_net); 951 952 if (WARN_ON_ONCE((rt->dst.flags & DST_NOCACHE) && 953 !atomic_read(&rt->dst.__refcnt))) 954 return -EINVAL; 955 956 if (info->nlh) { 957 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 958 allow_create = 0; 959 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 960 replace_required = 1; 961 } 962 if (!allow_create && !replace_required) 963 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 964 965 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 966 offsetof(struct rt6_info, rt6i_dst), allow_create, 967 replace_required, sernum); 968 if (IS_ERR(fn)) { 969 err = PTR_ERR(fn); 970 fn = NULL; 971 goto out; 972 } 973 974 pn = fn; 975 976#ifdef CONFIG_IPV6_SUBTREES 977 if (rt->rt6i_src.plen) { 978 struct fib6_node *sn; 979 980 if (!fn->subtree) { 981 struct fib6_node *sfn; 982 983 /* 984 * Create subtree. 985 * 986 * fn[main tree] 987 * | 988 * sfn[subtree root] 989 * \ 990 * sn[new leaf node] 991 */ 992 993 /* Create subtree root node */ 994 sfn = node_alloc(); 995 if (!sfn) 996 goto st_failure; 997 998 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 999 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 1000 sfn->fn_flags = RTN_ROOT; 1001 sfn->fn_sernum = sernum; 1002 1003 /* Now add the first leaf node to new subtree */ 1004 1005 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 1006 rt->rt6i_src.plen, 1007 offsetof(struct rt6_info, rt6i_src), 1008 allow_create, replace_required, sernum); 1009 1010 if (IS_ERR(sn)) { 1011 /* If it is failed, discard just allocated 1012 root, and then (in st_failure) stale node 1013 in main tree. 1014 */ 1015 node_free(sfn); 1016 err = PTR_ERR(sn); 1017 goto st_failure; 1018 } 1019 1020 /* Now link new subtree to main tree */ 1021 sfn->parent = fn; 1022 fn->subtree = sfn; 1023 } else { 1024 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 1025 rt->rt6i_src.plen, 1026 offsetof(struct rt6_info, rt6i_src), 1027 allow_create, replace_required, sernum); 1028 1029 if (IS_ERR(sn)) { 1030 err = PTR_ERR(sn); 1031 goto st_failure; 1032 } 1033 } 1034 1035 if (!fn->leaf) { 1036 fn->leaf = rt; 1037 atomic_inc(&rt->rt6i_ref); 1038 } 1039 fn = sn; 1040 } 1041#endif 1042 1043 err = fib6_add_rt2node(fn, rt, info, mxc); 1044 if (!err) { 1045 fib6_start_gc(info->nl_net, rt); 1046 if (!(rt->rt6i_flags & RTF_CACHE)) 1047 fib6_prune_clones(info->nl_net, pn); 1048 rt->dst.flags &= ~DST_NOCACHE; 1049 } 1050 1051out: 1052 if (err) { 1053#ifdef CONFIG_IPV6_SUBTREES 1054 /* 1055 * If fib6_add_1 has cleared the old leaf pointer in the 1056 * super-tree leaf node we have to find a new one for it. 1057 */ 1058 if (pn != fn && pn->leaf == rt) { 1059 pn->leaf = NULL; 1060 atomic_dec(&rt->rt6i_ref); 1061 } 1062 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 1063 pn->leaf = fib6_find_prefix(info->nl_net, pn); 1064#if RT6_DEBUG >= 2 1065 if (!pn->leaf) { 1066 WARN_ON(pn->leaf == NULL); 1067 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 1068 } 1069#endif 1070 atomic_inc(&pn->leaf->rt6i_ref); 1071 } 1072#endif 1073 if (!(rt->dst.flags & DST_NOCACHE)) 1074 dst_free(&rt->dst); 1075 } 1076 return err; 1077 1078#ifdef CONFIG_IPV6_SUBTREES 1079 /* Subtree creation failed, probably main tree node 1080 is orphan. If it is, shoot it. 1081 */ 1082st_failure: 1083 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1084 fib6_repair_tree(info->nl_net, fn); 1085 if (!(rt->dst.flags & DST_NOCACHE)) 1086 dst_free(&rt->dst); 1087 return err; 1088#endif 1089} 1090 1091/* 1092 * Routing tree lookup 1093 * 1094 */ 1095 1096struct lookup_args { 1097 int offset; /* key offset on rt6_info */ 1098 const struct in6_addr *addr; /* search key */ 1099}; 1100 1101static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1102 struct lookup_args *args) 1103{ 1104 struct fib6_node *fn; 1105 __be32 dir; 1106 1107 if (unlikely(args->offset == 0)) 1108 return NULL; 1109 1110 /* 1111 * Descend on a tree 1112 */ 1113 1114 fn = root; 1115 1116 for (;;) { 1117 struct fib6_node *next; 1118 1119 dir = addr_bit_set(args->addr, fn->fn_bit); 1120 1121 next = dir ? fn->right : fn->left; 1122 1123 if (next) { 1124 fn = next; 1125 continue; 1126 } 1127 break; 1128 } 1129 1130 while (fn) { 1131 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1132 struct rt6key *key; 1133 1134 key = (struct rt6key *) ((u8 *) fn->leaf + 1135 args->offset); 1136 1137 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1138#ifdef CONFIG_IPV6_SUBTREES 1139 if (fn->subtree) { 1140 struct fib6_node *sfn; 1141 sfn = fib6_lookup_1(fn->subtree, 1142 args + 1); 1143 if (!sfn) 1144 goto backtrack; 1145 fn = sfn; 1146 } 1147#endif 1148 if (fn->fn_flags & RTN_RTINFO) 1149 return fn; 1150 } 1151 } 1152#ifdef CONFIG_IPV6_SUBTREES 1153backtrack: 1154#endif 1155 if (fn->fn_flags & RTN_ROOT) 1156 break; 1157 1158 fn = fn->parent; 1159 } 1160 1161 return NULL; 1162} 1163 1164struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1165 const struct in6_addr *saddr) 1166{ 1167 struct fib6_node *fn; 1168 struct lookup_args args[] = { 1169 { 1170 .offset = offsetof(struct rt6_info, rt6i_dst), 1171 .addr = daddr, 1172 }, 1173#ifdef CONFIG_IPV6_SUBTREES 1174 { 1175 .offset = offsetof(struct rt6_info, rt6i_src), 1176 .addr = saddr, 1177 }, 1178#endif 1179 { 1180 .offset = 0, /* sentinel */ 1181 } 1182 }; 1183 1184 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1185 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1186 fn = root; 1187 1188 return fn; 1189} 1190 1191/* 1192 * Get node with specified destination prefix (and source prefix, 1193 * if subtrees are used) 1194 */ 1195 1196 1197static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1198 const struct in6_addr *addr, 1199 int plen, int offset) 1200{ 1201 struct fib6_node *fn; 1202 1203 for (fn = root; fn ; ) { 1204 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1205 1206 /* 1207 * Prefix match 1208 */ 1209 if (plen < fn->fn_bit || 1210 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1211 return NULL; 1212 1213 if (plen == fn->fn_bit) 1214 return fn; 1215 1216 /* 1217 * We have more bits to go 1218 */ 1219 if (addr_bit_set(addr, fn->fn_bit)) 1220 fn = fn->right; 1221 else 1222 fn = fn->left; 1223 } 1224 return NULL; 1225} 1226 1227struct fib6_node *fib6_locate(struct fib6_node *root, 1228 const struct in6_addr *daddr, int dst_len, 1229 const struct in6_addr *saddr, int src_len) 1230{ 1231 struct fib6_node *fn; 1232 1233 fn = fib6_locate_1(root, daddr, dst_len, 1234 offsetof(struct rt6_info, rt6i_dst)); 1235 1236#ifdef CONFIG_IPV6_SUBTREES 1237 if (src_len) { 1238 WARN_ON(saddr == NULL); 1239 if (fn && fn->subtree) 1240 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1241 offsetof(struct rt6_info, rt6i_src)); 1242 } 1243#endif 1244 1245 if (fn && fn->fn_flags & RTN_RTINFO) 1246 return fn; 1247 1248 return NULL; 1249} 1250 1251 1252/* 1253 * Deletion 1254 * 1255 */ 1256 1257static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1258{ 1259 if (fn->fn_flags & RTN_ROOT) 1260 return net->ipv6.ip6_null_entry; 1261 1262 while (fn) { 1263 if (fn->left) 1264 return fn->left->leaf; 1265 if (fn->right) 1266 return fn->right->leaf; 1267 1268 fn = FIB6_SUBTREE(fn); 1269 } 1270 return NULL; 1271} 1272 1273/* 1274 * Called to trim the tree of intermediate nodes when possible. "fn" 1275 * is the node we want to try and remove. 1276 */ 1277 1278static struct fib6_node *fib6_repair_tree(struct net *net, 1279 struct fib6_node *fn) 1280{ 1281 int children; 1282 int nstate; 1283 struct fib6_node *child, *pn; 1284 struct fib6_walker *w; 1285 int iter = 0; 1286 1287 for (;;) { 1288 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1289 iter++; 1290 1291 WARN_ON(fn->fn_flags & RTN_RTINFO); 1292 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1293 WARN_ON(fn->leaf); 1294 1295 children = 0; 1296 child = NULL; 1297 if (fn->right) 1298 child = fn->right, children |= 1; 1299 if (fn->left) 1300 child = fn->left, children |= 2; 1301 1302 if (children == 3 || FIB6_SUBTREE(fn) 1303#ifdef CONFIG_IPV6_SUBTREES 1304 /* Subtree root (i.e. fn) may have one child */ 1305 || (children && fn->fn_flags & RTN_ROOT) 1306#endif 1307 ) { 1308 fn->leaf = fib6_find_prefix(net, fn); 1309#if RT6_DEBUG >= 2 1310 if (!fn->leaf) { 1311 WARN_ON(!fn->leaf); 1312 fn->leaf = net->ipv6.ip6_null_entry; 1313 } 1314#endif 1315 atomic_inc(&fn->leaf->rt6i_ref); 1316 return fn->parent; 1317 } 1318 1319 pn = fn->parent; 1320#ifdef CONFIG_IPV6_SUBTREES 1321 if (FIB6_SUBTREE(pn) == fn) { 1322 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1323 FIB6_SUBTREE(pn) = NULL; 1324 nstate = FWS_L; 1325 } else { 1326 WARN_ON(fn->fn_flags & RTN_ROOT); 1327#endif 1328 if (pn->right == fn) 1329 pn->right = child; 1330 else if (pn->left == fn) 1331 pn->left = child; 1332#if RT6_DEBUG >= 2 1333 else 1334 WARN_ON(1); 1335#endif 1336 if (child) 1337 child->parent = pn; 1338 nstate = FWS_R; 1339#ifdef CONFIG_IPV6_SUBTREES 1340 } 1341#endif 1342 1343 read_lock(&fib6_walker_lock); 1344 FOR_WALKERS(w) { 1345 if (!child) { 1346 if (w->root == fn) { 1347 w->root = w->node = NULL; 1348 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1349 } else if (w->node == fn) { 1350 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1351 w->node = pn; 1352 w->state = nstate; 1353 } 1354 } else { 1355 if (w->root == fn) { 1356 w->root = child; 1357 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1358 } 1359 if (w->node == fn) { 1360 w->node = child; 1361 if (children&2) { 1362 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1363 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1364 } else { 1365 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1366 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1367 } 1368 } 1369 } 1370 } 1371 read_unlock(&fib6_walker_lock); 1372 1373 node_free(fn); 1374 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1375 return pn; 1376 1377 rt6_release(pn->leaf); 1378 pn->leaf = NULL; 1379 fn = pn; 1380 } 1381} 1382 1383static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1384 struct nl_info *info) 1385{ 1386 struct fib6_walker *w; 1387 struct rt6_info *rt = *rtp; 1388 struct net *net = info->nl_net; 1389 1390 RT6_TRACE("fib6_del_route\n"); 1391 1392 /* Unlink it */ 1393 *rtp = rt->dst.rt6_next; 1394 rt->rt6i_node = NULL; 1395 net->ipv6.rt6_stats->fib_rt_entries--; 1396 net->ipv6.rt6_stats->fib_discarded_routes++; 1397 1398 /* Reset round-robin state, if necessary */ 1399 if (fn->rr_ptr == rt) 1400 fn->rr_ptr = NULL; 1401 1402 /* Remove this entry from other siblings */ 1403 if (rt->rt6i_nsiblings) { 1404 struct rt6_info *sibling, *next_sibling; 1405 1406 list_for_each_entry_safe(sibling, next_sibling, 1407 &rt->rt6i_siblings, rt6i_siblings) 1408 sibling->rt6i_nsiblings--; 1409 rt->rt6i_nsiblings = 0; 1410 list_del_init(&rt->rt6i_siblings); 1411 } 1412 1413 /* Adjust walkers */ 1414 read_lock(&fib6_walker_lock); 1415 FOR_WALKERS(w) { 1416 if (w->state == FWS_C && w->leaf == rt) { 1417 RT6_TRACE("walker %p adjusted by delroute\n", w); 1418 w->leaf = rt->dst.rt6_next; 1419 if (!w->leaf) 1420 w->state = FWS_U; 1421 } 1422 } 1423 read_unlock(&fib6_walker_lock); 1424 1425 rt->dst.rt6_next = NULL; 1426 1427 /* If it was last route, expunge its radix tree node */ 1428 if (!fn->leaf) { 1429 fn->fn_flags &= ~RTN_RTINFO; 1430 net->ipv6.rt6_stats->fib_route_nodes--; 1431 fn = fib6_repair_tree(net, fn); 1432 } 1433 1434 fib6_purge_rt(rt, fn, net); 1435 1436 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1437 rt6_release(rt); 1438} 1439 1440int fib6_del(struct rt6_info *rt, struct nl_info *info) 1441{ 1442 struct net *net = info->nl_net; 1443 struct fib6_node *fn = rt->rt6i_node; 1444 struct rt6_info **rtp; 1445 1446#if RT6_DEBUG >= 2 1447 if (rt->dst.obsolete > 0) { 1448 WARN_ON(fn); 1449 return -ENOENT; 1450 } 1451#endif 1452 if (!fn || rt == net->ipv6.ip6_null_entry) 1453 return -ENOENT; 1454 1455 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1456 1457 if (!(rt->rt6i_flags & RTF_CACHE)) { 1458 struct fib6_node *pn = fn; 1459#ifdef CONFIG_IPV6_SUBTREES 1460 /* clones of this route might be in another subtree */ 1461 if (rt->rt6i_src.plen) { 1462 while (!(pn->fn_flags & RTN_ROOT)) 1463 pn = pn->parent; 1464 pn = pn->parent; 1465 } 1466#endif 1467 fib6_prune_clones(info->nl_net, pn); 1468 } 1469 1470 /* 1471 * Walk the leaf entries looking for ourself 1472 */ 1473 1474 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1475 if (*rtp == rt) { 1476 fib6_del_route(fn, rtp, info); 1477 return 0; 1478 } 1479 } 1480 return -ENOENT; 1481} 1482 1483/* 1484 * Tree traversal function. 1485 * 1486 * Certainly, it is not interrupt safe. 1487 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1488 * It means, that we can modify tree during walking 1489 * and use this function for garbage collection, clone pruning, 1490 * cleaning tree when a device goes down etc. etc. 1491 * 1492 * It guarantees that every node will be traversed, 1493 * and that it will be traversed only once. 1494 * 1495 * Callback function w->func may return: 1496 * 0 -> continue walking. 1497 * positive value -> walking is suspended (used by tree dumps, 1498 * and probably by gc, if it will be split to several slices) 1499 * negative value -> terminate walking. 1500 * 1501 * The function itself returns: 1502 * 0 -> walk is complete. 1503 * >0 -> walk is incomplete (i.e. suspended) 1504 * <0 -> walk is terminated by an error. 1505 */ 1506 1507static int fib6_walk_continue(struct fib6_walker *w) 1508{ 1509 struct fib6_node *fn, *pn; 1510 1511 for (;;) { 1512 fn = w->node; 1513 if (!fn) 1514 return 0; 1515 1516 if (w->prune && fn != w->root && 1517 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1518 w->state = FWS_C; 1519 w->leaf = fn->leaf; 1520 } 1521 switch (w->state) { 1522#ifdef CONFIG_IPV6_SUBTREES 1523 case FWS_S: 1524 if (FIB6_SUBTREE(fn)) { 1525 w->node = FIB6_SUBTREE(fn); 1526 continue; 1527 } 1528 w->state = FWS_L; 1529#endif 1530 case FWS_L: 1531 if (fn->left) { 1532 w->node = fn->left; 1533 w->state = FWS_INIT; 1534 continue; 1535 } 1536 w->state = FWS_R; 1537 case FWS_R: 1538 if (fn->right) { 1539 w->node = fn->right; 1540 w->state = FWS_INIT; 1541 continue; 1542 } 1543 w->state = FWS_C; 1544 w->leaf = fn->leaf; 1545 case FWS_C: 1546 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1547 int err; 1548 1549 if (w->skip) { 1550 w->skip--; 1551 goto skip; 1552 } 1553 1554 err = w->func(w); 1555 if (err) 1556 return err; 1557 1558 w->count++; 1559 continue; 1560 } 1561skip: 1562 w->state = FWS_U; 1563 case FWS_U: 1564 if (fn == w->root) 1565 return 0; 1566 pn = fn->parent; 1567 w->node = pn; 1568#ifdef CONFIG_IPV6_SUBTREES 1569 if (FIB6_SUBTREE(pn) == fn) { 1570 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1571 w->state = FWS_L; 1572 continue; 1573 } 1574#endif 1575 if (pn->left == fn) { 1576 w->state = FWS_R; 1577 continue; 1578 } 1579 if (pn->right == fn) { 1580 w->state = FWS_C; 1581 w->leaf = w->node->leaf; 1582 continue; 1583 } 1584#if RT6_DEBUG >= 2 1585 WARN_ON(1); 1586#endif 1587 } 1588 } 1589} 1590 1591static int fib6_walk(struct fib6_walker *w) 1592{ 1593 int res; 1594 1595 w->state = FWS_INIT; 1596 w->node = w->root; 1597 1598 fib6_walker_link(w); 1599 res = fib6_walk_continue(w); 1600 if (res <= 0) 1601 fib6_walker_unlink(w); 1602 return res; 1603} 1604 1605static int fib6_clean_node(struct fib6_walker *w) 1606{ 1607 int res; 1608 struct rt6_info *rt; 1609 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1610 struct nl_info info = { 1611 .nl_net = c->net, 1612 }; 1613 1614 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1615 w->node->fn_sernum != c->sernum) 1616 w->node->fn_sernum = c->sernum; 1617 1618 if (!c->func) { 1619 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1620 w->leaf = NULL; 1621 return 0; 1622 } 1623 1624 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1625 res = c->func(rt, c->arg); 1626 if (res < 0) { 1627 w->leaf = rt; 1628 res = fib6_del(rt, &info); 1629 if (res) { 1630#if RT6_DEBUG >= 2 1631 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1632 __func__, rt, rt->rt6i_node, res); 1633#endif 1634 continue; 1635 } 1636 return 0; 1637 } 1638 WARN_ON(res != 0); 1639 } 1640 w->leaf = rt; 1641 return 0; 1642} 1643 1644/* 1645 * Convenient frontend to tree walker. 1646 * 1647 * func is called on each route. 1648 * It may return -1 -> delete this route. 1649 * 0 -> continue walking 1650 * 1651 * prune==1 -> only immediate children of node (certainly, 1652 * ignoring pure split nodes) will be scanned. 1653 */ 1654 1655static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1656 int (*func)(struct rt6_info *, void *arg), 1657 bool prune, int sernum, void *arg) 1658{ 1659 struct fib6_cleaner c; 1660 1661 c.w.root = root; 1662 c.w.func = fib6_clean_node; 1663 c.w.prune = prune; 1664 c.w.count = 0; 1665 c.w.skip = 0; 1666 c.func = func; 1667 c.sernum = sernum; 1668 c.arg = arg; 1669 c.net = net; 1670 1671 fib6_walk(&c.w); 1672} 1673 1674static void __fib6_clean_all(struct net *net, 1675 int (*func)(struct rt6_info *, void *), 1676 int sernum, void *arg) 1677{ 1678 struct fib6_table *table; 1679 struct hlist_head *head; 1680 unsigned int h; 1681 1682 rcu_read_lock(); 1683 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1684 head = &net->ipv6.fib_table_hash[h]; 1685 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1686 write_lock_bh(&table->tb6_lock); 1687 fib6_clean_tree(net, &table->tb6_root, 1688 func, false, sernum, arg); 1689 write_unlock_bh(&table->tb6_lock); 1690 } 1691 } 1692 rcu_read_unlock(); 1693} 1694 1695void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1696 void *arg) 1697{ 1698 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1699} 1700 1701static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1702{ 1703 if (rt->rt6i_flags & RTF_CACHE) { 1704 RT6_TRACE("pruning clone %p\n", rt); 1705 return -1; 1706 } 1707 1708 return 0; 1709} 1710 1711static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1712{ 1713 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1714 FIB6_NO_SERNUM_CHANGE, NULL); 1715} 1716 1717static void fib6_flush_trees(struct net *net) 1718{ 1719 int new_sernum = fib6_new_sernum(net); 1720 1721 __fib6_clean_all(net, NULL, new_sernum, NULL); 1722} 1723 1724/* 1725 * Garbage collection 1726 */ 1727 1728static struct fib6_gc_args 1729{ 1730 int timeout; 1731 int more; 1732} gc_args; 1733 1734static int fib6_age(struct rt6_info *rt, void *arg) 1735{ 1736 unsigned long now = jiffies; 1737 1738 /* 1739 * check addrconf expiration here. 1740 * Routes are expired even if they are in use. 1741 * 1742 * Also age clones. Note, that clones are aged out 1743 * only if they are not in use now. 1744 */ 1745 1746 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1747 if (time_after(now, rt->dst.expires)) { 1748 RT6_TRACE("expiring %p\n", rt); 1749 return -1; 1750 } 1751 gc_args.more++; 1752 } else if (rt->rt6i_flags & RTF_CACHE) { 1753 if (atomic_read(&rt->dst.__refcnt) == 0 && 1754 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) { 1755 RT6_TRACE("aging clone %p\n", rt); 1756 return -1; 1757 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1758 struct neighbour *neigh; 1759 __u8 neigh_flags = 0; 1760 1761 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1762 if (neigh) { 1763 neigh_flags = neigh->flags; 1764 neigh_release(neigh); 1765 } 1766 if (!(neigh_flags & NTF_ROUTER)) { 1767 RT6_TRACE("purging route %p via non-router but gateway\n", 1768 rt); 1769 return -1; 1770 } 1771 } 1772 gc_args.more++; 1773 } 1774 1775 return 0; 1776} 1777 1778static DEFINE_SPINLOCK(fib6_gc_lock); 1779 1780void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1781{ 1782 unsigned long now; 1783 1784 if (force) { 1785 spin_lock_bh(&fib6_gc_lock); 1786 } else if (!spin_trylock_bh(&fib6_gc_lock)) { 1787 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1788 return; 1789 } 1790 gc_args.timeout = expires ? (int)expires : 1791 net->ipv6.sysctl.ip6_rt_gc_interval; 1792 1793 gc_args.more = icmp6_dst_gc(); 1794 1795 fib6_clean_all(net, fib6_age, NULL); 1796 now = jiffies; 1797 net->ipv6.ip6_rt_last_gc = now; 1798 1799 if (gc_args.more) 1800 mod_timer(&net->ipv6.ip6_fib_timer, 1801 round_jiffies(now 1802 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1803 else 1804 del_timer(&net->ipv6.ip6_fib_timer); 1805 spin_unlock_bh(&fib6_gc_lock); 1806} 1807 1808static void fib6_gc_timer_cb(unsigned long arg) 1809{ 1810 fib6_run_gc(0, (struct net *)arg, true); 1811} 1812 1813static int __net_init fib6_net_init(struct net *net) 1814{ 1815 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1816 1817 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1818 1819 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1820 if (!net->ipv6.rt6_stats) 1821 goto out_timer; 1822 1823 /* Avoid false sharing : Use at least a full cache line */ 1824 size = max_t(size_t, size, L1_CACHE_BYTES); 1825 1826 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1827 if (!net->ipv6.fib_table_hash) 1828 goto out_rt6_stats; 1829 1830 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1831 GFP_KERNEL); 1832 if (!net->ipv6.fib6_main_tbl) 1833 goto out_fib_table_hash; 1834 1835 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1836 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1837 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1838 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1839 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1840 1841#ifdef CONFIG_IPV6_MULTIPLE_TABLES 1842 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1843 GFP_KERNEL); 1844 if (!net->ipv6.fib6_local_tbl) 1845 goto out_fib6_main_tbl; 1846 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1847 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1848 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1849 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1850 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1851#endif 1852 fib6_tables_init(net); 1853 1854 return 0; 1855 1856#ifdef CONFIG_IPV6_MULTIPLE_TABLES 1857out_fib6_main_tbl: 1858 kfree(net->ipv6.fib6_main_tbl); 1859#endif 1860out_fib_table_hash: 1861 kfree(net->ipv6.fib_table_hash); 1862out_rt6_stats: 1863 kfree(net->ipv6.rt6_stats); 1864out_timer: 1865 return -ENOMEM; 1866} 1867 1868static void fib6_net_exit(struct net *net) 1869{ 1870 rt6_ifdown(net, NULL); 1871 del_timer_sync(&net->ipv6.ip6_fib_timer); 1872 1873#ifdef CONFIG_IPV6_MULTIPLE_TABLES 1874 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 1875 kfree(net->ipv6.fib6_local_tbl); 1876#endif 1877 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 1878 kfree(net->ipv6.fib6_main_tbl); 1879 kfree(net->ipv6.fib_table_hash); 1880 kfree(net->ipv6.rt6_stats); 1881} 1882 1883static struct pernet_operations fib6_net_ops = { 1884 .init = fib6_net_init, 1885 .exit = fib6_net_exit, 1886}; 1887 1888int __init fib6_init(void) 1889{ 1890 int ret = -ENOMEM; 1891 1892 fib6_node_kmem = kmem_cache_create("fib6_nodes", 1893 sizeof(struct fib6_node), 1894 0, SLAB_HWCACHE_ALIGN, 1895 NULL); 1896 if (!fib6_node_kmem) 1897 goto out; 1898 1899 ret = register_pernet_subsys(&fib6_net_ops); 1900 if (ret) 1901 goto out_kmem_cache_create; 1902 1903 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 1904 NULL); 1905 if (ret) 1906 goto out_unregister_subsys; 1907 1908 __fib6_flush_trees = fib6_flush_trees; 1909out: 1910 return ret; 1911 1912out_unregister_subsys: 1913 unregister_pernet_subsys(&fib6_net_ops); 1914out_kmem_cache_create: 1915 kmem_cache_destroy(fib6_node_kmem); 1916 goto out; 1917} 1918 1919void fib6_gc_cleanup(void) 1920{ 1921 unregister_pernet_subsys(&fib6_net_ops); 1922 kmem_cache_destroy(fib6_node_kmem); 1923} 1924 1925#ifdef CONFIG_PROC_FS 1926 1927struct ipv6_route_iter { 1928 struct seq_net_private p; 1929 struct fib6_walker w; 1930 loff_t skip; 1931 struct fib6_table *tbl; 1932 int sernum; 1933}; 1934 1935static int ipv6_route_seq_show(struct seq_file *seq, void *v) 1936{ 1937 struct rt6_info *rt = v; 1938 struct ipv6_route_iter *iter = seq->private; 1939 1940 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 1941 1942#ifdef CONFIG_IPV6_SUBTREES 1943 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 1944#else 1945 seq_puts(seq, "00000000000000000000000000000000 00 "); 1946#endif 1947 if (rt->rt6i_flags & RTF_GATEWAY) 1948 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 1949 else 1950 seq_puts(seq, "00000000000000000000000000000000"); 1951 1952 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 1953 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 1954 rt->dst.__use, rt->rt6i_flags, 1955 rt->dst.dev ? rt->dst.dev->name : ""); 1956 iter->w.leaf = NULL; 1957 return 0; 1958} 1959 1960static int ipv6_route_yield(struct fib6_walker *w) 1961{ 1962 struct ipv6_route_iter *iter = w->args; 1963 1964 if (!iter->skip) 1965 return 1; 1966 1967 do { 1968 iter->w.leaf = iter->w.leaf->dst.rt6_next; 1969 iter->skip--; 1970 if (!iter->skip && iter->w.leaf) 1971 return 1; 1972 } while (iter->w.leaf); 1973 1974 return 0; 1975} 1976 1977static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter) 1978{ 1979 memset(&iter->w, 0, sizeof(iter->w)); 1980 iter->w.func = ipv6_route_yield; 1981 iter->w.root = &iter->tbl->tb6_root; 1982 iter->w.state = FWS_INIT; 1983 iter->w.node = iter->w.root; 1984 iter->w.args = iter; 1985 iter->sernum = iter->w.root->fn_sernum; 1986 INIT_LIST_HEAD(&iter->w.lh); 1987 fib6_walker_link(&iter->w); 1988} 1989 1990static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 1991 struct net *net) 1992{ 1993 unsigned int h; 1994 struct hlist_node *node; 1995 1996 if (tbl) { 1997 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 1998 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 1999 } else { 2000 h = 0; 2001 node = NULL; 2002 } 2003 2004 while (!node && h < FIB6_TABLE_HASHSZ) { 2005 node = rcu_dereference_bh( 2006 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2007 } 2008 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2009} 2010 2011static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2012{ 2013 if (iter->sernum != iter->w.root->fn_sernum) { 2014 iter->sernum = iter->w.root->fn_sernum; 2015 iter->w.state = FWS_INIT; 2016 iter->w.node = iter->w.root; 2017 WARN_ON(iter->w.skip); 2018 iter->w.skip = iter->w.count; 2019 } 2020} 2021 2022static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2023{ 2024 int r; 2025 struct rt6_info *n; 2026 struct net *net = seq_file_net(seq); 2027 struct ipv6_route_iter *iter = seq->private; 2028 2029 if (!v) 2030 goto iter_table; 2031 2032 n = ((struct rt6_info *)v)->dst.rt6_next; 2033 if (n) { 2034 ++*pos; 2035 return n; 2036 } 2037 2038iter_table: 2039 ipv6_route_check_sernum(iter); 2040 read_lock(&iter->tbl->tb6_lock); 2041 r = fib6_walk_continue(&iter->w); 2042 read_unlock(&iter->tbl->tb6_lock); 2043 if (r > 0) { 2044 if (v) 2045 ++*pos; 2046 return iter->w.leaf; 2047 } else if (r < 0) { 2048 fib6_walker_unlink(&iter->w); 2049 return NULL; 2050 } 2051 fib6_walker_unlink(&iter->w); 2052 2053 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2054 if (!iter->tbl) 2055 return NULL; 2056 2057 ipv6_route_seq_setup_walk(iter); 2058 goto iter_table; 2059} 2060 2061static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2062 __acquires(RCU_BH) 2063{ 2064 struct net *net = seq_file_net(seq); 2065 struct ipv6_route_iter *iter = seq->private; 2066 2067 rcu_read_lock_bh(); 2068 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2069 iter->skip = *pos; 2070 2071 if (iter->tbl) { 2072 ipv6_route_seq_setup_walk(iter); 2073 return ipv6_route_seq_next(seq, NULL, pos); 2074 } else { 2075 return NULL; 2076 } 2077} 2078 2079static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2080{ 2081 struct fib6_walker *w = &iter->w; 2082 return w->node && !(w->state == FWS_U && w->node == w->root); 2083} 2084 2085static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2086 __releases(RCU_BH) 2087{ 2088 struct ipv6_route_iter *iter = seq->private; 2089 2090 if (ipv6_route_iter_active(iter)) 2091 fib6_walker_unlink(&iter->w); 2092 2093 rcu_read_unlock_bh(); 2094} 2095 2096static const struct seq_operations ipv6_route_seq_ops = { 2097 .start = ipv6_route_seq_start, 2098 .next = ipv6_route_seq_next, 2099 .stop = ipv6_route_seq_stop, 2100 .show = ipv6_route_seq_show 2101}; 2102 2103int ipv6_route_open(struct inode *inode, struct file *file) 2104{ 2105 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2106 sizeof(struct ipv6_route_iter)); 2107} 2108 2109#endif /* CONFIG_PROC_FS */ 2110