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 #include <net/fib_notifier.h> 37 38 #include <net/ip6_fib.h> 39 #include <net/ip6_route.h> 40 41 #define RT6_DEBUG 2 42 43 #if RT6_DEBUG >= 3 44 #define RT6_TRACE(x...) pr_debug(x) 45 #else 46 #define RT6_TRACE(x...) do { ; } while (0) 47 #endif 48 49 static struct kmem_cache *fib6_node_kmem __read_mostly; 50 51 struct fib6_cleaner { 52 struct fib6_walker w; 53 struct net *net; 54 int (*func)(struct rt6_info *, void *arg); 55 int sernum; 56 void *arg; 57 }; 58 59 #ifdef CONFIG_IPV6_SUBTREES 60 #define FWS_INIT FWS_S 61 #else 62 #define FWS_INIT FWS_L 63 #endif 64 65 static void fib6_prune_clones(struct net *net, struct fib6_node *fn); 66 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 67 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 68 static int fib6_walk(struct net *net, struct fib6_walker *w); 69 static int fib6_walk_continue(struct fib6_walker *w); 70 71 /* 72 * A routing update causes an increase of the serial number on the 73 * affected subtree. This allows for cached routes to be asynchronously 74 * tested when modifications are made to the destination cache as a 75 * result of redirects, path MTU changes, etc. 76 */ 77 78 static void fib6_gc_timer_cb(unsigned long arg); 79 80 #define FOR_WALKERS(net, w) \ 81 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 82 83 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 84 { 85 write_lock_bh(&net->ipv6.fib6_walker_lock); 86 list_add(&w->lh, &net->ipv6.fib6_walkers); 87 write_unlock_bh(&net->ipv6.fib6_walker_lock); 88 } 89 90 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 91 { 92 write_lock_bh(&net->ipv6.fib6_walker_lock); 93 list_del(&w->lh); 94 write_unlock_bh(&net->ipv6.fib6_walker_lock); 95 } 96 97 static int fib6_new_sernum(struct net *net) 98 { 99 int new, old; 100 101 do { 102 old = atomic_read(&net->ipv6.fib6_sernum); 103 new = old < INT_MAX ? old + 1 : 1; 104 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 105 old, new) != old); 106 return new; 107 } 108 109 enum { 110 FIB6_NO_SERNUM_CHANGE = 0, 111 }; 112 113 /* 114 * Auxiliary address test functions for the radix tree. 115 * 116 * These assume a 32bit processor (although it will work on 117 * 64bit processors) 118 */ 119 120 /* 121 * test bit 122 */ 123 #if defined(__LITTLE_ENDIAN) 124 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 125 #else 126 # define BITOP_BE32_SWIZZLE 0 127 #endif 128 129 static __be32 addr_bit_set(const void *token, int fn_bit) 130 { 131 const __be32 *addr = token; 132 /* 133 * Here, 134 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 135 * is optimized version of 136 * htonl(1 << ((~fn_bit)&0x1F)) 137 * See include/asm-generic/bitops/le.h. 138 */ 139 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 140 addr[fn_bit >> 5]; 141 } 142 143 static struct fib6_node *node_alloc(void) 144 { 145 struct fib6_node *fn; 146 147 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 148 149 return fn; 150 } 151 152 static void node_free(struct fib6_node *fn) 153 { 154 kmem_cache_free(fib6_node_kmem, fn); 155 } 156 157 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) 158 { 159 int cpu; 160 161 if (!non_pcpu_rt->rt6i_pcpu) 162 return; 163 164 for_each_possible_cpu(cpu) { 165 struct rt6_info **ppcpu_rt; 166 struct rt6_info *pcpu_rt; 167 168 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 169 pcpu_rt = *ppcpu_rt; 170 if (pcpu_rt) { 171 dst_dev_put(&pcpu_rt->dst); 172 dst_release(&pcpu_rt->dst); 173 *ppcpu_rt = NULL; 174 } 175 } 176 177 free_percpu(non_pcpu_rt->rt6i_pcpu); 178 non_pcpu_rt->rt6i_pcpu = NULL; 179 } 180 EXPORT_SYMBOL_GPL(rt6_free_pcpu); 181 182 static void fib6_link_table(struct net *net, struct fib6_table *tb) 183 { 184 unsigned int h; 185 186 /* 187 * Initialize table lock at a single place to give lockdep a key, 188 * tables aren't visible prior to being linked to the list. 189 */ 190 rwlock_init(&tb->tb6_lock); 191 192 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 193 194 /* 195 * No protection necessary, this is the only list mutatation 196 * operation, tables never disappear once they exist. 197 */ 198 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 199 } 200 201 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 202 203 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 204 { 205 struct fib6_table *table; 206 207 table = kzalloc(sizeof(*table), GFP_ATOMIC); 208 if (table) { 209 table->tb6_id = id; 210 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 211 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 212 inet_peer_base_init(&table->tb6_peers); 213 } 214 215 return table; 216 } 217 218 struct fib6_table *fib6_new_table(struct net *net, u32 id) 219 { 220 struct fib6_table *tb; 221 222 if (id == 0) 223 id = RT6_TABLE_MAIN; 224 tb = fib6_get_table(net, id); 225 if (tb) 226 return tb; 227 228 tb = fib6_alloc_table(net, id); 229 if (tb) 230 fib6_link_table(net, tb); 231 232 return tb; 233 } 234 EXPORT_SYMBOL_GPL(fib6_new_table); 235 236 struct fib6_table *fib6_get_table(struct net *net, u32 id) 237 { 238 struct fib6_table *tb; 239 struct hlist_head *head; 240 unsigned int h; 241 242 if (id == 0) 243 id = RT6_TABLE_MAIN; 244 h = id & (FIB6_TABLE_HASHSZ - 1); 245 rcu_read_lock(); 246 head = &net->ipv6.fib_table_hash[h]; 247 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 248 if (tb->tb6_id == id) { 249 rcu_read_unlock(); 250 return tb; 251 } 252 } 253 rcu_read_unlock(); 254 255 return NULL; 256 } 257 EXPORT_SYMBOL_GPL(fib6_get_table); 258 259 static void __net_init fib6_tables_init(struct net *net) 260 { 261 fib6_link_table(net, net->ipv6.fib6_main_tbl); 262 fib6_link_table(net, net->ipv6.fib6_local_tbl); 263 } 264 #else 265 266 struct fib6_table *fib6_new_table(struct net *net, u32 id) 267 { 268 return fib6_get_table(net, id); 269 } 270 271 struct fib6_table *fib6_get_table(struct net *net, u32 id) 272 { 273 return net->ipv6.fib6_main_tbl; 274 } 275 276 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 277 int flags, pol_lookup_t lookup) 278 { 279 struct rt6_info *rt; 280 281 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 282 if (rt->dst.error == -EAGAIN) { 283 ip6_rt_put(rt); 284 rt = net->ipv6.ip6_null_entry; 285 dst_hold(&rt->dst); 286 } 287 288 return &rt->dst; 289 } 290 291 static void __net_init fib6_tables_init(struct net *net) 292 { 293 fib6_link_table(net, net->ipv6.fib6_main_tbl); 294 } 295 296 #endif 297 298 unsigned int fib6_tables_seq_read(struct net *net) 299 { 300 unsigned int h, fib_seq = 0; 301 302 rcu_read_lock(); 303 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 304 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 305 struct fib6_table *tb; 306 307 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 308 read_lock_bh(&tb->tb6_lock); 309 fib_seq += tb->fib_seq; 310 read_unlock_bh(&tb->tb6_lock); 311 } 312 } 313 rcu_read_unlock(); 314 315 return fib_seq; 316 } 317 318 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 319 enum fib_event_type event_type, 320 struct rt6_info *rt) 321 { 322 struct fib6_entry_notifier_info info = { 323 .rt = rt, 324 }; 325 326 return call_fib6_notifier(nb, net, event_type, &info.info); 327 } 328 329 static int call_fib6_entry_notifiers(struct net *net, 330 enum fib_event_type event_type, 331 struct rt6_info *rt) 332 { 333 struct fib6_entry_notifier_info info = { 334 .rt = rt, 335 }; 336 337 rt->rt6i_table->fib_seq++; 338 return call_fib6_notifiers(net, event_type, &info.info); 339 } 340 341 struct fib6_dump_arg { 342 struct net *net; 343 struct notifier_block *nb; 344 }; 345 346 static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg) 347 { 348 if (rt == arg->net->ipv6.ip6_null_entry) 349 return; 350 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 351 } 352 353 static int fib6_node_dump(struct fib6_walker *w) 354 { 355 struct rt6_info *rt; 356 357 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) 358 fib6_rt_dump(rt, w->args); 359 w->leaf = NULL; 360 return 0; 361 } 362 363 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 364 struct fib6_walker *w) 365 { 366 w->root = &tb->tb6_root; 367 read_lock_bh(&tb->tb6_lock); 368 fib6_walk(net, w); 369 read_unlock_bh(&tb->tb6_lock); 370 } 371 372 /* Called with rcu_read_lock() */ 373 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 374 { 375 struct fib6_dump_arg arg; 376 struct fib6_walker *w; 377 unsigned int h; 378 379 w = kzalloc(sizeof(*w), GFP_ATOMIC); 380 if (!w) 381 return -ENOMEM; 382 383 w->func = fib6_node_dump; 384 arg.net = net; 385 arg.nb = nb; 386 w->args = &arg; 387 388 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 389 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 390 struct fib6_table *tb; 391 392 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 393 fib6_table_dump(net, tb, w); 394 } 395 396 kfree(w); 397 398 return 0; 399 } 400 401 static int fib6_dump_node(struct fib6_walker *w) 402 { 403 int res; 404 struct rt6_info *rt; 405 406 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 407 res = rt6_dump_route(rt, w->args); 408 if (res < 0) { 409 /* Frame is full, suspend walking */ 410 w->leaf = rt; 411 return 1; 412 } 413 414 /* Multipath routes are dumped in one route with the 415 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 416 * last sibling of this route (no need to dump the 417 * sibling routes again) 418 */ 419 if (rt->rt6i_nsiblings) 420 rt = list_last_entry(&rt->rt6i_siblings, 421 struct rt6_info, 422 rt6i_siblings); 423 } 424 w->leaf = NULL; 425 return 0; 426 } 427 428 static void fib6_dump_end(struct netlink_callback *cb) 429 { 430 struct net *net = sock_net(cb->skb->sk); 431 struct fib6_walker *w = (void *)cb->args[2]; 432 433 if (w) { 434 if (cb->args[4]) { 435 cb->args[4] = 0; 436 fib6_walker_unlink(net, w); 437 } 438 cb->args[2] = 0; 439 kfree(w); 440 } 441 cb->done = (void *)cb->args[3]; 442 cb->args[1] = 3; 443 } 444 445 static int fib6_dump_done(struct netlink_callback *cb) 446 { 447 fib6_dump_end(cb); 448 return cb->done ? cb->done(cb) : 0; 449 } 450 451 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 452 struct netlink_callback *cb) 453 { 454 struct net *net = sock_net(skb->sk); 455 struct fib6_walker *w; 456 int res; 457 458 w = (void *)cb->args[2]; 459 w->root = &table->tb6_root; 460 461 if (cb->args[4] == 0) { 462 w->count = 0; 463 w->skip = 0; 464 465 read_lock_bh(&table->tb6_lock); 466 res = fib6_walk(net, w); 467 read_unlock_bh(&table->tb6_lock); 468 if (res > 0) { 469 cb->args[4] = 1; 470 cb->args[5] = w->root->fn_sernum; 471 } 472 } else { 473 if (cb->args[5] != w->root->fn_sernum) { 474 /* Begin at the root if the tree changed */ 475 cb->args[5] = w->root->fn_sernum; 476 w->state = FWS_INIT; 477 w->node = w->root; 478 w->skip = w->count; 479 } else 480 w->skip = 0; 481 482 read_lock_bh(&table->tb6_lock); 483 res = fib6_walk_continue(w); 484 read_unlock_bh(&table->tb6_lock); 485 if (res <= 0) { 486 fib6_walker_unlink(net, w); 487 cb->args[4] = 0; 488 } 489 } 490 491 return res; 492 } 493 494 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 495 { 496 struct net *net = sock_net(skb->sk); 497 unsigned int h, s_h; 498 unsigned int e = 0, s_e; 499 struct rt6_rtnl_dump_arg arg; 500 struct fib6_walker *w; 501 struct fib6_table *tb; 502 struct hlist_head *head; 503 int res = 0; 504 505 s_h = cb->args[0]; 506 s_e = cb->args[1]; 507 508 w = (void *)cb->args[2]; 509 if (!w) { 510 /* New dump: 511 * 512 * 1. hook callback destructor. 513 */ 514 cb->args[3] = (long)cb->done; 515 cb->done = fib6_dump_done; 516 517 /* 518 * 2. allocate and initialize walker. 519 */ 520 w = kzalloc(sizeof(*w), GFP_ATOMIC); 521 if (!w) 522 return -ENOMEM; 523 w->func = fib6_dump_node; 524 cb->args[2] = (long)w; 525 } 526 527 arg.skb = skb; 528 arg.cb = cb; 529 arg.net = net; 530 w->args = &arg; 531 532 rcu_read_lock(); 533 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 534 e = 0; 535 head = &net->ipv6.fib_table_hash[h]; 536 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 537 if (e < s_e) 538 goto next; 539 res = fib6_dump_table(tb, skb, cb); 540 if (res != 0) 541 goto out; 542 next: 543 e++; 544 } 545 } 546 out: 547 rcu_read_unlock(); 548 cb->args[1] = e; 549 cb->args[0] = h; 550 551 res = res < 0 ? res : skb->len; 552 if (res <= 0) 553 fib6_dump_end(cb); 554 return res; 555 } 556 557 /* 558 * Routing Table 559 * 560 * return the appropriate node for a routing tree "add" operation 561 * by either creating and inserting or by returning an existing 562 * node. 563 */ 564 565 static struct fib6_node *fib6_add_1(struct fib6_node *root, 566 struct in6_addr *addr, int plen, 567 int offset, int allow_create, 568 int replace_required, int sernum, 569 struct netlink_ext_ack *extack) 570 { 571 struct fib6_node *fn, *in, *ln; 572 struct fib6_node *pn = NULL; 573 struct rt6key *key; 574 int bit; 575 __be32 dir = 0; 576 577 RT6_TRACE("fib6_add_1\n"); 578 579 /* insert node in tree */ 580 581 fn = root; 582 583 do { 584 key = (struct rt6key *)((u8 *)fn->leaf + offset); 585 586 /* 587 * Prefix match 588 */ 589 if (plen < fn->fn_bit || 590 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 591 if (!allow_create) { 592 if (replace_required) { 593 NL_SET_ERR_MSG(extack, 594 "Can not replace route - no match found"); 595 pr_warn("Can't replace route, no match found\n"); 596 return ERR_PTR(-ENOENT); 597 } 598 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 599 } 600 goto insert_above; 601 } 602 603 /* 604 * Exact match ? 605 */ 606 607 if (plen == fn->fn_bit) { 608 /* clean up an intermediate node */ 609 if (!(fn->fn_flags & RTN_RTINFO)) { 610 rt6_release(fn->leaf); 611 fn->leaf = NULL; 612 } 613 614 fn->fn_sernum = sernum; 615 616 return fn; 617 } 618 619 /* 620 * We have more bits to go 621 */ 622 623 /* Try to walk down on tree. */ 624 fn->fn_sernum = sernum; 625 dir = addr_bit_set(addr, fn->fn_bit); 626 pn = fn; 627 fn = dir ? fn->right : fn->left; 628 } while (fn); 629 630 if (!allow_create) { 631 /* We should not create new node because 632 * NLM_F_REPLACE was specified without NLM_F_CREATE 633 * I assume it is safe to require NLM_F_CREATE when 634 * REPLACE flag is used! Later we may want to remove the 635 * check for replace_required, because according 636 * to netlink specification, NLM_F_CREATE 637 * MUST be specified if new route is created. 638 * That would keep IPv6 consistent with IPv4 639 */ 640 if (replace_required) { 641 NL_SET_ERR_MSG(extack, 642 "Can not replace route - no match found"); 643 pr_warn("Can't replace route, no match found\n"); 644 return ERR_PTR(-ENOENT); 645 } 646 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 647 } 648 /* 649 * We walked to the bottom of tree. 650 * Create new leaf node without children. 651 */ 652 653 ln = node_alloc(); 654 655 if (!ln) 656 return ERR_PTR(-ENOMEM); 657 ln->fn_bit = plen; 658 659 ln->parent = pn; 660 ln->fn_sernum = sernum; 661 662 if (dir) 663 pn->right = ln; 664 else 665 pn->left = ln; 666 667 return ln; 668 669 670 insert_above: 671 /* 672 * split since we don't have a common prefix anymore or 673 * we have a less significant route. 674 * we've to insert an intermediate node on the list 675 * this new node will point to the one we need to create 676 * and the current 677 */ 678 679 pn = fn->parent; 680 681 /* find 1st bit in difference between the 2 addrs. 682 683 See comment in __ipv6_addr_diff: bit may be an invalid value, 684 but if it is >= plen, the value is ignored in any case. 685 */ 686 687 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 688 689 /* 690 * (intermediate)[in] 691 * / \ 692 * (new leaf node)[ln] (old node)[fn] 693 */ 694 if (plen > bit) { 695 in = node_alloc(); 696 ln = node_alloc(); 697 698 if (!in || !ln) { 699 if (in) 700 node_free(in); 701 if (ln) 702 node_free(ln); 703 return ERR_PTR(-ENOMEM); 704 } 705 706 /* 707 * new intermediate node. 708 * RTN_RTINFO will 709 * be off since that an address that chooses one of 710 * the branches would not match less specific routes 711 * in the other branch 712 */ 713 714 in->fn_bit = bit; 715 716 in->parent = pn; 717 in->leaf = fn->leaf; 718 atomic_inc(&in->leaf->rt6i_ref); 719 720 in->fn_sernum = sernum; 721 722 /* update parent pointer */ 723 if (dir) 724 pn->right = in; 725 else 726 pn->left = in; 727 728 ln->fn_bit = plen; 729 730 ln->parent = in; 731 fn->parent = in; 732 733 ln->fn_sernum = sernum; 734 735 if (addr_bit_set(addr, bit)) { 736 in->right = ln; 737 in->left = fn; 738 } else { 739 in->left = ln; 740 in->right = fn; 741 } 742 } else { /* plen <= bit */ 743 744 /* 745 * (new leaf node)[ln] 746 * / \ 747 * (old node)[fn] NULL 748 */ 749 750 ln = node_alloc(); 751 752 if (!ln) 753 return ERR_PTR(-ENOMEM); 754 755 ln->fn_bit = plen; 756 757 ln->parent = pn; 758 759 ln->fn_sernum = sernum; 760 761 if (dir) 762 pn->right = ln; 763 else 764 pn->left = ln; 765 766 if (addr_bit_set(&key->addr, plen)) 767 ln->right = fn; 768 else 769 ln->left = fn; 770 771 fn->parent = ln; 772 } 773 return ln; 774 } 775 776 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 777 { 778 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 779 RTF_GATEWAY; 780 } 781 782 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 783 { 784 int i; 785 786 for (i = 0; i < RTAX_MAX; i++) { 787 if (test_bit(i, mxc->mx_valid)) 788 mp[i] = mxc->mx[i]; 789 } 790 } 791 792 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 793 { 794 if (!mxc->mx) 795 return 0; 796 797 if (dst->flags & DST_HOST) { 798 u32 *mp = dst_metrics_write_ptr(dst); 799 800 if (unlikely(!mp)) 801 return -ENOMEM; 802 803 fib6_copy_metrics(mp, mxc); 804 } else { 805 dst_init_metrics(dst, mxc->mx, false); 806 807 /* We've stolen mx now. */ 808 mxc->mx = NULL; 809 } 810 811 return 0; 812 } 813 814 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 815 struct net *net) 816 { 817 if (atomic_read(&rt->rt6i_ref) != 1) { 818 /* This route is used as dummy address holder in some split 819 * nodes. It is not leaked, but it still holds other resources, 820 * which must be released in time. So, scan ascendant nodes 821 * and replace dummy references to this route with references 822 * to still alive ones. 823 */ 824 while (fn) { 825 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 826 fn->leaf = fib6_find_prefix(net, fn); 827 atomic_inc(&fn->leaf->rt6i_ref); 828 rt6_release(rt); 829 } 830 fn = fn->parent; 831 } 832 } 833 } 834 835 /* 836 * Insert routing information in a node. 837 */ 838 839 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 840 struct nl_info *info, struct mx6_config *mxc) 841 { 842 struct rt6_info *iter = NULL; 843 struct rt6_info **ins; 844 struct rt6_info **fallback_ins = NULL; 845 int replace = (info->nlh && 846 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 847 int add = (!info->nlh || 848 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 849 int found = 0; 850 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 851 u16 nlflags = NLM_F_EXCL; 852 int err; 853 854 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 855 nlflags |= NLM_F_APPEND; 856 857 ins = &fn->leaf; 858 859 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 860 /* 861 * Search for duplicates 862 */ 863 864 if (iter->rt6i_metric == rt->rt6i_metric) { 865 /* 866 * Same priority level 867 */ 868 if (info->nlh && 869 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 870 return -EEXIST; 871 872 nlflags &= ~NLM_F_EXCL; 873 if (replace) { 874 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 875 found++; 876 break; 877 } 878 if (rt_can_ecmp) 879 fallback_ins = fallback_ins ?: ins; 880 goto next_iter; 881 } 882 883 if (rt6_duplicate_nexthop(iter, rt)) { 884 if (rt->rt6i_nsiblings) 885 rt->rt6i_nsiblings = 0; 886 if (!(iter->rt6i_flags & RTF_EXPIRES)) 887 return -EEXIST; 888 if (!(rt->rt6i_flags & RTF_EXPIRES)) 889 rt6_clean_expires(iter); 890 else 891 rt6_set_expires(iter, rt->dst.expires); 892 iter->rt6i_pmtu = rt->rt6i_pmtu; 893 return -EEXIST; 894 } 895 /* If we have the same destination and the same metric, 896 * but not the same gateway, then the route we try to 897 * add is sibling to this route, increment our counter 898 * of siblings, and later we will add our route to the 899 * list. 900 * Only static routes (which don't have flag 901 * RTF_EXPIRES) are used for ECMPv6. 902 * 903 * To avoid long list, we only had siblings if the 904 * route have a gateway. 905 */ 906 if (rt_can_ecmp && 907 rt6_qualify_for_ecmp(iter)) 908 rt->rt6i_nsiblings++; 909 } 910 911 if (iter->rt6i_metric > rt->rt6i_metric) 912 break; 913 914 next_iter: 915 ins = &iter->dst.rt6_next; 916 } 917 918 if (fallback_ins && !found) { 919 /* No ECMP-able route found, replace first non-ECMP one */ 920 ins = fallback_ins; 921 iter = *ins; 922 found++; 923 } 924 925 /* Reset round-robin state, if necessary */ 926 if (ins == &fn->leaf) 927 fn->rr_ptr = NULL; 928 929 /* Link this route to others same route. */ 930 if (rt->rt6i_nsiblings) { 931 unsigned int rt6i_nsiblings; 932 struct rt6_info *sibling, *temp_sibling; 933 934 /* Find the first route that have the same metric */ 935 sibling = fn->leaf; 936 while (sibling) { 937 if (sibling->rt6i_metric == rt->rt6i_metric && 938 rt6_qualify_for_ecmp(sibling)) { 939 list_add_tail(&rt->rt6i_siblings, 940 &sibling->rt6i_siblings); 941 break; 942 } 943 sibling = sibling->dst.rt6_next; 944 } 945 /* For each sibling in the list, increment the counter of 946 * siblings. BUG() if counters does not match, list of siblings 947 * is broken! 948 */ 949 rt6i_nsiblings = 0; 950 list_for_each_entry_safe(sibling, temp_sibling, 951 &rt->rt6i_siblings, rt6i_siblings) { 952 sibling->rt6i_nsiblings++; 953 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 954 rt6i_nsiblings++; 955 } 956 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 957 } 958 959 /* 960 * insert node 961 */ 962 if (!replace) { 963 if (!add) 964 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 965 966 add: 967 nlflags |= NLM_F_CREATE; 968 err = fib6_commit_metrics(&rt->dst, mxc); 969 if (err) 970 return err; 971 972 rt->dst.rt6_next = iter; 973 *ins = rt; 974 rt->rt6i_node = fn; 975 atomic_inc(&rt->rt6i_ref); 976 call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_ADD, 977 rt); 978 if (!info->skip_notify) 979 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 980 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 981 982 if (!(fn->fn_flags & RTN_RTINFO)) { 983 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 984 fn->fn_flags |= RTN_RTINFO; 985 } 986 987 } else { 988 int nsiblings; 989 990 if (!found) { 991 if (add) 992 goto add; 993 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 994 return -ENOENT; 995 } 996 997 err = fib6_commit_metrics(&rt->dst, mxc); 998 if (err) 999 return err; 1000 1001 *ins = rt; 1002 rt->rt6i_node = fn; 1003 rt->dst.rt6_next = iter->dst.rt6_next; 1004 atomic_inc(&rt->rt6i_ref); 1005 call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_REPLACE, 1006 rt); 1007 if (!info->skip_notify) 1008 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1009 if (!(fn->fn_flags & RTN_RTINFO)) { 1010 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1011 fn->fn_flags |= RTN_RTINFO; 1012 } 1013 nsiblings = iter->rt6i_nsiblings; 1014 iter->rt6i_node = NULL; 1015 fib6_purge_rt(iter, fn, info->nl_net); 1016 if (fn->rr_ptr == iter) 1017 fn->rr_ptr = NULL; 1018 rt6_release(iter); 1019 1020 if (nsiblings) { 1021 /* Replacing an ECMP route, remove all siblings */ 1022 ins = &rt->dst.rt6_next; 1023 iter = *ins; 1024 while (iter) { 1025 if (iter->rt6i_metric > rt->rt6i_metric) 1026 break; 1027 if (rt6_qualify_for_ecmp(iter)) { 1028 *ins = iter->dst.rt6_next; 1029 iter->rt6i_node = NULL; 1030 fib6_purge_rt(iter, fn, info->nl_net); 1031 if (fn->rr_ptr == iter) 1032 fn->rr_ptr = NULL; 1033 rt6_release(iter); 1034 nsiblings--; 1035 } else { 1036 ins = &iter->dst.rt6_next; 1037 } 1038 iter = *ins; 1039 } 1040 WARN_ON(nsiblings != 0); 1041 } 1042 } 1043 1044 return 0; 1045 } 1046 1047 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 1048 { 1049 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1050 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 1051 mod_timer(&net->ipv6.ip6_fib_timer, 1052 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1053 } 1054 1055 void fib6_force_start_gc(struct net *net) 1056 { 1057 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1058 mod_timer(&net->ipv6.ip6_fib_timer, 1059 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1060 } 1061 1062 /* 1063 * Add routing information to the routing tree. 1064 * <destination addr>/<source addr> 1065 * with source addr info in sub-trees 1066 */ 1067 1068 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 1069 struct nl_info *info, struct mx6_config *mxc, 1070 struct netlink_ext_ack *extack) 1071 { 1072 struct fib6_node *fn, *pn = NULL; 1073 int err = -ENOMEM; 1074 int allow_create = 1; 1075 int replace_required = 0; 1076 int sernum = fib6_new_sernum(info->nl_net); 1077 1078 if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt))) 1079 return -EINVAL; 1080 1081 if (info->nlh) { 1082 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1083 allow_create = 0; 1084 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1085 replace_required = 1; 1086 } 1087 if (!allow_create && !replace_required) 1088 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1089 1090 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 1091 offsetof(struct rt6_info, rt6i_dst), allow_create, 1092 replace_required, sernum, extack); 1093 if (IS_ERR(fn)) { 1094 err = PTR_ERR(fn); 1095 fn = NULL; 1096 goto out; 1097 } 1098 1099 pn = fn; 1100 1101 #ifdef CONFIG_IPV6_SUBTREES 1102 if (rt->rt6i_src.plen) { 1103 struct fib6_node *sn; 1104 1105 if (!fn->subtree) { 1106 struct fib6_node *sfn; 1107 1108 /* 1109 * Create subtree. 1110 * 1111 * fn[main tree] 1112 * | 1113 * sfn[subtree root] 1114 * \ 1115 * sn[new leaf node] 1116 */ 1117 1118 /* Create subtree root node */ 1119 sfn = node_alloc(); 1120 if (!sfn) 1121 goto failure; 1122 1123 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 1124 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 1125 sfn->fn_flags = RTN_ROOT; 1126 sfn->fn_sernum = sernum; 1127 1128 /* Now add the first leaf node to new subtree */ 1129 1130 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 1131 rt->rt6i_src.plen, 1132 offsetof(struct rt6_info, rt6i_src), 1133 allow_create, replace_required, sernum, 1134 extack); 1135 1136 if (IS_ERR(sn)) { 1137 /* If it is failed, discard just allocated 1138 root, and then (in failure) stale node 1139 in main tree. 1140 */ 1141 node_free(sfn); 1142 err = PTR_ERR(sn); 1143 goto failure; 1144 } 1145 1146 /* Now link new subtree to main tree */ 1147 sfn->parent = fn; 1148 fn->subtree = sfn; 1149 } else { 1150 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 1151 rt->rt6i_src.plen, 1152 offsetof(struct rt6_info, rt6i_src), 1153 allow_create, replace_required, sernum, 1154 extack); 1155 1156 if (IS_ERR(sn)) { 1157 err = PTR_ERR(sn); 1158 goto failure; 1159 } 1160 } 1161 1162 if (!fn->leaf) { 1163 fn->leaf = rt; 1164 atomic_inc(&rt->rt6i_ref); 1165 } 1166 fn = sn; 1167 } 1168 #endif 1169 1170 err = fib6_add_rt2node(fn, rt, info, mxc); 1171 if (!err) { 1172 fib6_start_gc(info->nl_net, rt); 1173 if (!(rt->rt6i_flags & RTF_CACHE)) 1174 fib6_prune_clones(info->nl_net, pn); 1175 } 1176 1177 out: 1178 if (err) { 1179 #ifdef CONFIG_IPV6_SUBTREES 1180 /* 1181 * If fib6_add_1 has cleared the old leaf pointer in the 1182 * super-tree leaf node we have to find a new one for it. 1183 */ 1184 if (pn != fn && pn->leaf == rt) { 1185 pn->leaf = NULL; 1186 atomic_dec(&rt->rt6i_ref); 1187 } 1188 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 1189 pn->leaf = fib6_find_prefix(info->nl_net, pn); 1190 #if RT6_DEBUG >= 2 1191 if (!pn->leaf) { 1192 WARN_ON(pn->leaf == NULL); 1193 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 1194 } 1195 #endif 1196 atomic_inc(&pn->leaf->rt6i_ref); 1197 } 1198 #endif 1199 goto failure; 1200 } 1201 return err; 1202 1203 failure: 1204 /* fn->leaf could be NULL if fn is an intermediate node and we 1205 * failed to add the new route to it in both subtree creation 1206 * failure and fib6_add_rt2node() failure case. 1207 * In both cases, fib6_repair_tree() should be called to fix 1208 * fn->leaf. 1209 */ 1210 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1211 fib6_repair_tree(info->nl_net, fn); 1212 /* Always release dst as dst->__refcnt is guaranteed 1213 * to be taken before entering this function 1214 */ 1215 dst_release_immediate(&rt->dst); 1216 return err; 1217 } 1218 1219 /* 1220 * Routing tree lookup 1221 * 1222 */ 1223 1224 struct lookup_args { 1225 int offset; /* key offset on rt6_info */ 1226 const struct in6_addr *addr; /* search key */ 1227 }; 1228 1229 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1230 struct lookup_args *args) 1231 { 1232 struct fib6_node *fn; 1233 __be32 dir; 1234 1235 if (unlikely(args->offset == 0)) 1236 return NULL; 1237 1238 /* 1239 * Descend on a tree 1240 */ 1241 1242 fn = root; 1243 1244 for (;;) { 1245 struct fib6_node *next; 1246 1247 dir = addr_bit_set(args->addr, fn->fn_bit); 1248 1249 next = dir ? fn->right : fn->left; 1250 1251 if (next) { 1252 fn = next; 1253 continue; 1254 } 1255 break; 1256 } 1257 1258 while (fn) { 1259 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1260 struct rt6key *key; 1261 1262 key = (struct rt6key *) ((u8 *) fn->leaf + 1263 args->offset); 1264 1265 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1266 #ifdef CONFIG_IPV6_SUBTREES 1267 if (fn->subtree) { 1268 struct fib6_node *sfn; 1269 sfn = fib6_lookup_1(fn->subtree, 1270 args + 1); 1271 if (!sfn) 1272 goto backtrack; 1273 fn = sfn; 1274 } 1275 #endif 1276 if (fn->fn_flags & RTN_RTINFO) 1277 return fn; 1278 } 1279 } 1280 #ifdef CONFIG_IPV6_SUBTREES 1281 backtrack: 1282 #endif 1283 if (fn->fn_flags & RTN_ROOT) 1284 break; 1285 1286 fn = fn->parent; 1287 } 1288 1289 return NULL; 1290 } 1291 1292 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1293 const struct in6_addr *saddr) 1294 { 1295 struct fib6_node *fn; 1296 struct lookup_args args[] = { 1297 { 1298 .offset = offsetof(struct rt6_info, rt6i_dst), 1299 .addr = daddr, 1300 }, 1301 #ifdef CONFIG_IPV6_SUBTREES 1302 { 1303 .offset = offsetof(struct rt6_info, rt6i_src), 1304 .addr = saddr, 1305 }, 1306 #endif 1307 { 1308 .offset = 0, /* sentinel */ 1309 } 1310 }; 1311 1312 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1313 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1314 fn = root; 1315 1316 return fn; 1317 } 1318 1319 /* 1320 * Get node with specified destination prefix (and source prefix, 1321 * if subtrees are used) 1322 */ 1323 1324 1325 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1326 const struct in6_addr *addr, 1327 int plen, int offset) 1328 { 1329 struct fib6_node *fn; 1330 1331 for (fn = root; fn ; ) { 1332 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1333 1334 /* 1335 * Prefix match 1336 */ 1337 if (plen < fn->fn_bit || 1338 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1339 return NULL; 1340 1341 if (plen == fn->fn_bit) 1342 return fn; 1343 1344 /* 1345 * We have more bits to go 1346 */ 1347 if (addr_bit_set(addr, fn->fn_bit)) 1348 fn = fn->right; 1349 else 1350 fn = fn->left; 1351 } 1352 return NULL; 1353 } 1354 1355 struct fib6_node *fib6_locate(struct fib6_node *root, 1356 const struct in6_addr *daddr, int dst_len, 1357 const struct in6_addr *saddr, int src_len) 1358 { 1359 struct fib6_node *fn; 1360 1361 fn = fib6_locate_1(root, daddr, dst_len, 1362 offsetof(struct rt6_info, rt6i_dst)); 1363 1364 #ifdef CONFIG_IPV6_SUBTREES 1365 if (src_len) { 1366 WARN_ON(saddr == NULL); 1367 if (fn && fn->subtree) 1368 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1369 offsetof(struct rt6_info, rt6i_src)); 1370 } 1371 #endif 1372 1373 if (fn && fn->fn_flags & RTN_RTINFO) 1374 return fn; 1375 1376 return NULL; 1377 } 1378 1379 1380 /* 1381 * Deletion 1382 * 1383 */ 1384 1385 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1386 { 1387 if (fn->fn_flags & RTN_ROOT) 1388 return net->ipv6.ip6_null_entry; 1389 1390 while (fn) { 1391 if (fn->left) 1392 return fn->left->leaf; 1393 if (fn->right) 1394 return fn->right->leaf; 1395 1396 fn = FIB6_SUBTREE(fn); 1397 } 1398 return NULL; 1399 } 1400 1401 /* 1402 * Called to trim the tree of intermediate nodes when possible. "fn" 1403 * is the node we want to try and remove. 1404 */ 1405 1406 static struct fib6_node *fib6_repair_tree(struct net *net, 1407 struct fib6_node *fn) 1408 { 1409 int children; 1410 int nstate; 1411 struct fib6_node *child, *pn; 1412 struct fib6_walker *w; 1413 int iter = 0; 1414 1415 for (;;) { 1416 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1417 iter++; 1418 1419 WARN_ON(fn->fn_flags & RTN_RTINFO); 1420 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1421 WARN_ON(fn->leaf); 1422 1423 children = 0; 1424 child = NULL; 1425 if (fn->right) 1426 child = fn->right, children |= 1; 1427 if (fn->left) 1428 child = fn->left, children |= 2; 1429 1430 if (children == 3 || FIB6_SUBTREE(fn) 1431 #ifdef CONFIG_IPV6_SUBTREES 1432 /* Subtree root (i.e. fn) may have one child */ 1433 || (children && fn->fn_flags & RTN_ROOT) 1434 #endif 1435 ) { 1436 fn->leaf = fib6_find_prefix(net, fn); 1437 #if RT6_DEBUG >= 2 1438 if (!fn->leaf) { 1439 WARN_ON(!fn->leaf); 1440 fn->leaf = net->ipv6.ip6_null_entry; 1441 } 1442 #endif 1443 atomic_inc(&fn->leaf->rt6i_ref); 1444 return fn->parent; 1445 } 1446 1447 pn = fn->parent; 1448 #ifdef CONFIG_IPV6_SUBTREES 1449 if (FIB6_SUBTREE(pn) == fn) { 1450 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1451 FIB6_SUBTREE(pn) = NULL; 1452 nstate = FWS_L; 1453 } else { 1454 WARN_ON(fn->fn_flags & RTN_ROOT); 1455 #endif 1456 if (pn->right == fn) 1457 pn->right = child; 1458 else if (pn->left == fn) 1459 pn->left = child; 1460 #if RT6_DEBUG >= 2 1461 else 1462 WARN_ON(1); 1463 #endif 1464 if (child) 1465 child->parent = pn; 1466 nstate = FWS_R; 1467 #ifdef CONFIG_IPV6_SUBTREES 1468 } 1469 #endif 1470 1471 read_lock(&net->ipv6.fib6_walker_lock); 1472 FOR_WALKERS(net, w) { 1473 if (!child) { 1474 if (w->root == fn) { 1475 w->root = w->node = NULL; 1476 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1477 } else if (w->node == fn) { 1478 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1479 w->node = pn; 1480 w->state = nstate; 1481 } 1482 } else { 1483 if (w->root == fn) { 1484 w->root = child; 1485 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1486 } 1487 if (w->node == fn) { 1488 w->node = child; 1489 if (children&2) { 1490 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1491 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1492 } else { 1493 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1494 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1495 } 1496 } 1497 } 1498 } 1499 read_unlock(&net->ipv6.fib6_walker_lock); 1500 1501 node_free(fn); 1502 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1503 return pn; 1504 1505 rt6_release(pn->leaf); 1506 pn->leaf = NULL; 1507 fn = pn; 1508 } 1509 } 1510 1511 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1512 struct nl_info *info) 1513 { 1514 struct fib6_walker *w; 1515 struct rt6_info *rt = *rtp; 1516 struct net *net = info->nl_net; 1517 1518 RT6_TRACE("fib6_del_route\n"); 1519 1520 /* Unlink it */ 1521 *rtp = rt->dst.rt6_next; 1522 rt->rt6i_node = NULL; 1523 net->ipv6.rt6_stats->fib_rt_entries--; 1524 net->ipv6.rt6_stats->fib_discarded_routes++; 1525 1526 /* Reset round-robin state, if necessary */ 1527 if (fn->rr_ptr == rt) 1528 fn->rr_ptr = NULL; 1529 1530 /* Remove this entry from other siblings */ 1531 if (rt->rt6i_nsiblings) { 1532 struct rt6_info *sibling, *next_sibling; 1533 1534 list_for_each_entry_safe(sibling, next_sibling, 1535 &rt->rt6i_siblings, rt6i_siblings) 1536 sibling->rt6i_nsiblings--; 1537 rt->rt6i_nsiblings = 0; 1538 list_del_init(&rt->rt6i_siblings); 1539 } 1540 1541 /* Adjust walkers */ 1542 read_lock(&net->ipv6.fib6_walker_lock); 1543 FOR_WALKERS(net, w) { 1544 if (w->state == FWS_C && w->leaf == rt) { 1545 RT6_TRACE("walker %p adjusted by delroute\n", w); 1546 w->leaf = rt->dst.rt6_next; 1547 if (!w->leaf) 1548 w->state = FWS_U; 1549 } 1550 } 1551 read_unlock(&net->ipv6.fib6_walker_lock); 1552 1553 rt->dst.rt6_next = NULL; 1554 1555 /* If it was last route, expunge its radix tree node */ 1556 if (!fn->leaf) { 1557 fn->fn_flags &= ~RTN_RTINFO; 1558 net->ipv6.rt6_stats->fib_route_nodes--; 1559 fn = fib6_repair_tree(net, fn); 1560 } 1561 1562 fib6_purge_rt(rt, fn, net); 1563 1564 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt); 1565 if (!info->skip_notify) 1566 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1567 rt6_release(rt); 1568 } 1569 1570 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1571 { 1572 struct net *net = info->nl_net; 1573 struct fib6_node *fn = rt->rt6i_node; 1574 struct rt6_info **rtp; 1575 1576 #if RT6_DEBUG >= 2 1577 if (rt->dst.obsolete > 0) { 1578 WARN_ON(fn); 1579 return -ENOENT; 1580 } 1581 #endif 1582 if (!fn || rt == net->ipv6.ip6_null_entry) 1583 return -ENOENT; 1584 1585 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1586 1587 if (!(rt->rt6i_flags & RTF_CACHE)) { 1588 struct fib6_node *pn = fn; 1589 #ifdef CONFIG_IPV6_SUBTREES 1590 /* clones of this route might be in another subtree */ 1591 if (rt->rt6i_src.plen) { 1592 while (!(pn->fn_flags & RTN_ROOT)) 1593 pn = pn->parent; 1594 pn = pn->parent; 1595 } 1596 #endif 1597 fib6_prune_clones(info->nl_net, pn); 1598 } 1599 1600 /* 1601 * Walk the leaf entries looking for ourself 1602 */ 1603 1604 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1605 if (*rtp == rt) { 1606 fib6_del_route(fn, rtp, info); 1607 return 0; 1608 } 1609 } 1610 return -ENOENT; 1611 } 1612 1613 /* 1614 * Tree traversal function. 1615 * 1616 * Certainly, it is not interrupt safe. 1617 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1618 * It means, that we can modify tree during walking 1619 * and use this function for garbage collection, clone pruning, 1620 * cleaning tree when a device goes down etc. etc. 1621 * 1622 * It guarantees that every node will be traversed, 1623 * and that it will be traversed only once. 1624 * 1625 * Callback function w->func may return: 1626 * 0 -> continue walking. 1627 * positive value -> walking is suspended (used by tree dumps, 1628 * and probably by gc, if it will be split to several slices) 1629 * negative value -> terminate walking. 1630 * 1631 * The function itself returns: 1632 * 0 -> walk is complete. 1633 * >0 -> walk is incomplete (i.e. suspended) 1634 * <0 -> walk is terminated by an error. 1635 */ 1636 1637 static int fib6_walk_continue(struct fib6_walker *w) 1638 { 1639 struct fib6_node *fn, *pn; 1640 1641 for (;;) { 1642 fn = w->node; 1643 if (!fn) 1644 return 0; 1645 1646 if (w->prune && fn != w->root && 1647 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1648 w->state = FWS_C; 1649 w->leaf = fn->leaf; 1650 } 1651 switch (w->state) { 1652 #ifdef CONFIG_IPV6_SUBTREES 1653 case FWS_S: 1654 if (FIB6_SUBTREE(fn)) { 1655 w->node = FIB6_SUBTREE(fn); 1656 continue; 1657 } 1658 w->state = FWS_L; 1659 #endif 1660 case FWS_L: 1661 if (fn->left) { 1662 w->node = fn->left; 1663 w->state = FWS_INIT; 1664 continue; 1665 } 1666 w->state = FWS_R; 1667 case FWS_R: 1668 if (fn->right) { 1669 w->node = fn->right; 1670 w->state = FWS_INIT; 1671 continue; 1672 } 1673 w->state = FWS_C; 1674 w->leaf = fn->leaf; 1675 case FWS_C: 1676 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1677 int err; 1678 1679 if (w->skip) { 1680 w->skip--; 1681 goto skip; 1682 } 1683 1684 err = w->func(w); 1685 if (err) 1686 return err; 1687 1688 w->count++; 1689 continue; 1690 } 1691 skip: 1692 w->state = FWS_U; 1693 case FWS_U: 1694 if (fn == w->root) 1695 return 0; 1696 pn = fn->parent; 1697 w->node = pn; 1698 #ifdef CONFIG_IPV6_SUBTREES 1699 if (FIB6_SUBTREE(pn) == fn) { 1700 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1701 w->state = FWS_L; 1702 continue; 1703 } 1704 #endif 1705 if (pn->left == fn) { 1706 w->state = FWS_R; 1707 continue; 1708 } 1709 if (pn->right == fn) { 1710 w->state = FWS_C; 1711 w->leaf = w->node->leaf; 1712 continue; 1713 } 1714 #if RT6_DEBUG >= 2 1715 WARN_ON(1); 1716 #endif 1717 } 1718 } 1719 } 1720 1721 static int fib6_walk(struct net *net, struct fib6_walker *w) 1722 { 1723 int res; 1724 1725 w->state = FWS_INIT; 1726 w->node = w->root; 1727 1728 fib6_walker_link(net, w); 1729 res = fib6_walk_continue(w); 1730 if (res <= 0) 1731 fib6_walker_unlink(net, w); 1732 return res; 1733 } 1734 1735 static int fib6_clean_node(struct fib6_walker *w) 1736 { 1737 int res; 1738 struct rt6_info *rt; 1739 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1740 struct nl_info info = { 1741 .nl_net = c->net, 1742 }; 1743 1744 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1745 w->node->fn_sernum != c->sernum) 1746 w->node->fn_sernum = c->sernum; 1747 1748 if (!c->func) { 1749 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1750 w->leaf = NULL; 1751 return 0; 1752 } 1753 1754 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1755 res = c->func(rt, c->arg); 1756 if (res < 0) { 1757 w->leaf = rt; 1758 res = fib6_del(rt, &info); 1759 if (res) { 1760 #if RT6_DEBUG >= 2 1761 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1762 __func__, rt, rt->rt6i_node, res); 1763 #endif 1764 continue; 1765 } 1766 return 0; 1767 } 1768 WARN_ON(res != 0); 1769 } 1770 w->leaf = rt; 1771 return 0; 1772 } 1773 1774 /* 1775 * Convenient frontend to tree walker. 1776 * 1777 * func is called on each route. 1778 * It may return -1 -> delete this route. 1779 * 0 -> continue walking 1780 * 1781 * prune==1 -> only immediate children of node (certainly, 1782 * ignoring pure split nodes) will be scanned. 1783 */ 1784 1785 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1786 int (*func)(struct rt6_info *, void *arg), 1787 bool prune, int sernum, void *arg) 1788 { 1789 struct fib6_cleaner c; 1790 1791 c.w.root = root; 1792 c.w.func = fib6_clean_node; 1793 c.w.prune = prune; 1794 c.w.count = 0; 1795 c.w.skip = 0; 1796 c.func = func; 1797 c.sernum = sernum; 1798 c.arg = arg; 1799 c.net = net; 1800 1801 fib6_walk(net, &c.w); 1802 } 1803 1804 static void __fib6_clean_all(struct net *net, 1805 int (*func)(struct rt6_info *, void *), 1806 int sernum, void *arg) 1807 { 1808 struct fib6_table *table; 1809 struct hlist_head *head; 1810 unsigned int h; 1811 1812 rcu_read_lock(); 1813 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1814 head = &net->ipv6.fib_table_hash[h]; 1815 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1816 write_lock_bh(&table->tb6_lock); 1817 fib6_clean_tree(net, &table->tb6_root, 1818 func, false, sernum, arg); 1819 write_unlock_bh(&table->tb6_lock); 1820 } 1821 } 1822 rcu_read_unlock(); 1823 } 1824 1825 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1826 void *arg) 1827 { 1828 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1829 } 1830 1831 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1832 { 1833 if (rt->rt6i_flags & RTF_CACHE) { 1834 RT6_TRACE("pruning clone %p\n", rt); 1835 return -1; 1836 } 1837 1838 return 0; 1839 } 1840 1841 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1842 { 1843 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1844 FIB6_NO_SERNUM_CHANGE, NULL); 1845 } 1846 1847 static void fib6_flush_trees(struct net *net) 1848 { 1849 int new_sernum = fib6_new_sernum(net); 1850 1851 __fib6_clean_all(net, NULL, new_sernum, NULL); 1852 } 1853 1854 /* 1855 * Garbage collection 1856 */ 1857 1858 struct fib6_gc_args 1859 { 1860 int timeout; 1861 int more; 1862 }; 1863 1864 static int fib6_age(struct rt6_info *rt, void *arg) 1865 { 1866 struct fib6_gc_args *gc_args = arg; 1867 unsigned long now = jiffies; 1868 1869 /* 1870 * check addrconf expiration here. 1871 * Routes are expired even if they are in use. 1872 * 1873 * Also age clones. Note, that clones are aged out 1874 * only if they are not in use now. 1875 */ 1876 1877 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1878 if (time_after(now, rt->dst.expires)) { 1879 RT6_TRACE("expiring %p\n", rt); 1880 return -1; 1881 } 1882 gc_args->more++; 1883 } else if (rt->rt6i_flags & RTF_CACHE) { 1884 if (atomic_read(&rt->dst.__refcnt) == 1 && 1885 time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) { 1886 RT6_TRACE("aging clone %p\n", rt); 1887 return -1; 1888 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1889 struct neighbour *neigh; 1890 __u8 neigh_flags = 0; 1891 1892 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1893 if (neigh) { 1894 neigh_flags = neigh->flags; 1895 neigh_release(neigh); 1896 } 1897 if (!(neigh_flags & NTF_ROUTER)) { 1898 RT6_TRACE("purging route %p via non-router but gateway\n", 1899 rt); 1900 return -1; 1901 } 1902 } 1903 gc_args->more++; 1904 } 1905 1906 return 0; 1907 } 1908 1909 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1910 { 1911 struct fib6_gc_args gc_args; 1912 unsigned long now; 1913 1914 if (force) { 1915 spin_lock_bh(&net->ipv6.fib6_gc_lock); 1916 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 1917 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1918 return; 1919 } 1920 gc_args.timeout = expires ? (int)expires : 1921 net->ipv6.sysctl.ip6_rt_gc_interval; 1922 gc_args.more = 0; 1923 1924 fib6_clean_all(net, fib6_age, &gc_args); 1925 now = jiffies; 1926 net->ipv6.ip6_rt_last_gc = now; 1927 1928 if (gc_args.more) 1929 mod_timer(&net->ipv6.ip6_fib_timer, 1930 round_jiffies(now 1931 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1932 else 1933 del_timer(&net->ipv6.ip6_fib_timer); 1934 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 1935 } 1936 1937 static void fib6_gc_timer_cb(unsigned long arg) 1938 { 1939 fib6_run_gc(0, (struct net *)arg, true); 1940 } 1941 1942 static int __net_init fib6_net_init(struct net *net) 1943 { 1944 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1945 int err; 1946 1947 err = fib6_notifier_init(net); 1948 if (err) 1949 return err; 1950 1951 spin_lock_init(&net->ipv6.fib6_gc_lock); 1952 rwlock_init(&net->ipv6.fib6_walker_lock); 1953 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 1954 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1955 1956 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1957 if (!net->ipv6.rt6_stats) 1958 goto out_timer; 1959 1960 /* Avoid false sharing : Use at least a full cache line */ 1961 size = max_t(size_t, size, L1_CACHE_BYTES); 1962 1963 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1964 if (!net->ipv6.fib_table_hash) 1965 goto out_rt6_stats; 1966 1967 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1968 GFP_KERNEL); 1969 if (!net->ipv6.fib6_main_tbl) 1970 goto out_fib_table_hash; 1971 1972 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1973 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1974 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1975 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1976 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 1977 1978 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1979 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 1980 GFP_KERNEL); 1981 if (!net->ipv6.fib6_local_tbl) 1982 goto out_fib6_main_tbl; 1983 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 1984 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1985 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 1986 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1987 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 1988 #endif 1989 fib6_tables_init(net); 1990 1991 return 0; 1992 1993 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1994 out_fib6_main_tbl: 1995 kfree(net->ipv6.fib6_main_tbl); 1996 #endif 1997 out_fib_table_hash: 1998 kfree(net->ipv6.fib_table_hash); 1999 out_rt6_stats: 2000 kfree(net->ipv6.rt6_stats); 2001 out_timer: 2002 fib6_notifier_exit(net); 2003 return -ENOMEM; 2004 } 2005 2006 static void fib6_net_exit(struct net *net) 2007 { 2008 rt6_ifdown(net, NULL); 2009 del_timer_sync(&net->ipv6.ip6_fib_timer); 2010 2011 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2012 inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers); 2013 kfree(net->ipv6.fib6_local_tbl); 2014 #endif 2015 inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers); 2016 kfree(net->ipv6.fib6_main_tbl); 2017 kfree(net->ipv6.fib_table_hash); 2018 kfree(net->ipv6.rt6_stats); 2019 fib6_notifier_exit(net); 2020 } 2021 2022 static struct pernet_operations fib6_net_ops = { 2023 .init = fib6_net_init, 2024 .exit = fib6_net_exit, 2025 }; 2026 2027 int __init fib6_init(void) 2028 { 2029 int ret = -ENOMEM; 2030 2031 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2032 sizeof(struct fib6_node), 2033 0, SLAB_HWCACHE_ALIGN, 2034 NULL); 2035 if (!fib6_node_kmem) 2036 goto out; 2037 2038 ret = register_pernet_subsys(&fib6_net_ops); 2039 if (ret) 2040 goto out_kmem_cache_create; 2041 2042 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 2043 0); 2044 if (ret) 2045 goto out_unregister_subsys; 2046 2047 __fib6_flush_trees = fib6_flush_trees; 2048 out: 2049 return ret; 2050 2051 out_unregister_subsys: 2052 unregister_pernet_subsys(&fib6_net_ops); 2053 out_kmem_cache_create: 2054 kmem_cache_destroy(fib6_node_kmem); 2055 goto out; 2056 } 2057 2058 void fib6_gc_cleanup(void) 2059 { 2060 unregister_pernet_subsys(&fib6_net_ops); 2061 kmem_cache_destroy(fib6_node_kmem); 2062 } 2063 2064 #ifdef CONFIG_PROC_FS 2065 2066 struct ipv6_route_iter { 2067 struct seq_net_private p; 2068 struct fib6_walker w; 2069 loff_t skip; 2070 struct fib6_table *tbl; 2071 int sernum; 2072 }; 2073 2074 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2075 { 2076 struct rt6_info *rt = v; 2077 struct ipv6_route_iter *iter = seq->private; 2078 2079 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 2080 2081 #ifdef CONFIG_IPV6_SUBTREES 2082 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 2083 #else 2084 seq_puts(seq, "00000000000000000000000000000000 00 "); 2085 #endif 2086 if (rt->rt6i_flags & RTF_GATEWAY) 2087 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 2088 else 2089 seq_puts(seq, "00000000000000000000000000000000"); 2090 2091 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2092 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 2093 rt->dst.__use, rt->rt6i_flags, 2094 rt->dst.dev ? rt->dst.dev->name : ""); 2095 iter->w.leaf = NULL; 2096 return 0; 2097 } 2098 2099 static int ipv6_route_yield(struct fib6_walker *w) 2100 { 2101 struct ipv6_route_iter *iter = w->args; 2102 2103 if (!iter->skip) 2104 return 1; 2105 2106 do { 2107 iter->w.leaf = iter->w.leaf->dst.rt6_next; 2108 iter->skip--; 2109 if (!iter->skip && iter->w.leaf) 2110 return 1; 2111 } while (iter->w.leaf); 2112 2113 return 0; 2114 } 2115 2116 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2117 struct net *net) 2118 { 2119 memset(&iter->w, 0, sizeof(iter->w)); 2120 iter->w.func = ipv6_route_yield; 2121 iter->w.root = &iter->tbl->tb6_root; 2122 iter->w.state = FWS_INIT; 2123 iter->w.node = iter->w.root; 2124 iter->w.args = iter; 2125 iter->sernum = iter->w.root->fn_sernum; 2126 INIT_LIST_HEAD(&iter->w.lh); 2127 fib6_walker_link(net, &iter->w); 2128 } 2129 2130 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2131 struct net *net) 2132 { 2133 unsigned int h; 2134 struct hlist_node *node; 2135 2136 if (tbl) { 2137 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2138 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2139 } else { 2140 h = 0; 2141 node = NULL; 2142 } 2143 2144 while (!node && h < FIB6_TABLE_HASHSZ) { 2145 node = rcu_dereference_bh( 2146 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2147 } 2148 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2149 } 2150 2151 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2152 { 2153 if (iter->sernum != iter->w.root->fn_sernum) { 2154 iter->sernum = iter->w.root->fn_sernum; 2155 iter->w.state = FWS_INIT; 2156 iter->w.node = iter->w.root; 2157 WARN_ON(iter->w.skip); 2158 iter->w.skip = iter->w.count; 2159 } 2160 } 2161 2162 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2163 { 2164 int r; 2165 struct rt6_info *n; 2166 struct net *net = seq_file_net(seq); 2167 struct ipv6_route_iter *iter = seq->private; 2168 2169 if (!v) 2170 goto iter_table; 2171 2172 n = ((struct rt6_info *)v)->dst.rt6_next; 2173 if (n) { 2174 ++*pos; 2175 return n; 2176 } 2177 2178 iter_table: 2179 ipv6_route_check_sernum(iter); 2180 read_lock(&iter->tbl->tb6_lock); 2181 r = fib6_walk_continue(&iter->w); 2182 read_unlock(&iter->tbl->tb6_lock); 2183 if (r > 0) { 2184 if (v) 2185 ++*pos; 2186 return iter->w.leaf; 2187 } else if (r < 0) { 2188 fib6_walker_unlink(net, &iter->w); 2189 return NULL; 2190 } 2191 fib6_walker_unlink(net, &iter->w); 2192 2193 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2194 if (!iter->tbl) 2195 return NULL; 2196 2197 ipv6_route_seq_setup_walk(iter, net); 2198 goto iter_table; 2199 } 2200 2201 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2202 __acquires(RCU_BH) 2203 { 2204 struct net *net = seq_file_net(seq); 2205 struct ipv6_route_iter *iter = seq->private; 2206 2207 rcu_read_lock_bh(); 2208 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2209 iter->skip = *pos; 2210 2211 if (iter->tbl) { 2212 ipv6_route_seq_setup_walk(iter, net); 2213 return ipv6_route_seq_next(seq, NULL, pos); 2214 } else { 2215 return NULL; 2216 } 2217 } 2218 2219 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2220 { 2221 struct fib6_walker *w = &iter->w; 2222 return w->node && !(w->state == FWS_U && w->node == w->root); 2223 } 2224 2225 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2226 __releases(RCU_BH) 2227 { 2228 struct net *net = seq_file_net(seq); 2229 struct ipv6_route_iter *iter = seq->private; 2230 2231 if (ipv6_route_iter_active(iter)) 2232 fib6_walker_unlink(net, &iter->w); 2233 2234 rcu_read_unlock_bh(); 2235 } 2236 2237 static const struct seq_operations ipv6_route_seq_ops = { 2238 .start = ipv6_route_seq_start, 2239 .next = ipv6_route_seq_next, 2240 .stop = ipv6_route_seq_stop, 2241 .show = ipv6_route_seq_show 2242 }; 2243 2244 int ipv6_route_open(struct inode *inode, struct file *file) 2245 { 2246 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2247 sizeof(struct ipv6_route_iter)); 2248 } 2249 2250 #endif /* CONFIG_PROC_FS */ 2251