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 static struct kmem_cache *fib6_node_kmem __read_mostly; 42 43 struct fib6_cleaner { 44 struct fib6_walker w; 45 struct net *net; 46 int (*func)(struct fib6_info *, void *arg); 47 int sernum; 48 void *arg; 49 }; 50 51 #ifdef CONFIG_IPV6_SUBTREES 52 #define FWS_INIT FWS_S 53 #else 54 #define FWS_INIT FWS_L 55 #endif 56 57 static struct fib6_info *fib6_find_prefix(struct net *net, 58 struct fib6_table *table, 59 struct fib6_node *fn); 60 static struct fib6_node *fib6_repair_tree(struct net *net, 61 struct fib6_table *table, 62 struct fib6_node *fn); 63 static int fib6_walk(struct net *net, struct fib6_walker *w); 64 static int fib6_walk_continue(struct fib6_walker *w); 65 66 /* 67 * A routing update causes an increase of the serial number on the 68 * affected subtree. This allows for cached routes to be asynchronously 69 * tested when modifications are made to the destination cache as a 70 * result of redirects, path MTU changes, etc. 71 */ 72 73 static void fib6_gc_timer_cb(struct timer_list *t); 74 75 #define FOR_WALKERS(net, w) \ 76 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 77 78 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 79 { 80 write_lock_bh(&net->ipv6.fib6_walker_lock); 81 list_add(&w->lh, &net->ipv6.fib6_walkers); 82 write_unlock_bh(&net->ipv6.fib6_walker_lock); 83 } 84 85 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 86 { 87 write_lock_bh(&net->ipv6.fib6_walker_lock); 88 list_del(&w->lh); 89 write_unlock_bh(&net->ipv6.fib6_walker_lock); 90 } 91 92 static int fib6_new_sernum(struct net *net) 93 { 94 int new, old; 95 96 do { 97 old = atomic_read(&net->ipv6.fib6_sernum); 98 new = old < INT_MAX ? old + 1 : 1; 99 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 100 old, new) != old); 101 return new; 102 } 103 104 enum { 105 FIB6_NO_SERNUM_CHANGE = 0, 106 }; 107 108 void fib6_update_sernum(struct net *net, struct fib6_info *f6i) 109 { 110 struct fib6_node *fn; 111 112 fn = rcu_dereference_protected(f6i->fib6_node, 113 lockdep_is_held(&f6i->fib6_table->tb6_lock)); 114 if (fn) 115 fn->fn_sernum = fib6_new_sernum(net); 116 } 117 118 /* 119 * Auxiliary address test functions for the radix tree. 120 * 121 * These assume a 32bit processor (although it will work on 122 * 64bit processors) 123 */ 124 125 /* 126 * test bit 127 */ 128 #if defined(__LITTLE_ENDIAN) 129 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 130 #else 131 # define BITOP_BE32_SWIZZLE 0 132 #endif 133 134 static __be32 addr_bit_set(const void *token, int fn_bit) 135 { 136 const __be32 *addr = token; 137 /* 138 * Here, 139 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 140 * is optimized version of 141 * htonl(1 << ((~fn_bit)&0x1F)) 142 * See include/asm-generic/bitops/le.h. 143 */ 144 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 145 addr[fn_bit >> 5]; 146 } 147 148 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags) 149 { 150 struct fib6_info *f6i; 151 152 f6i = kzalloc(sizeof(*f6i), gfp_flags); 153 if (!f6i) 154 return NULL; 155 156 f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); 157 if (!f6i->rt6i_pcpu) { 158 kfree(f6i); 159 return NULL; 160 } 161 162 INIT_LIST_HEAD(&f6i->fib6_siblings); 163 f6i->fib6_metrics = (struct dst_metrics *)&dst_default_metrics; 164 165 atomic_inc(&f6i->fib6_ref); 166 167 return f6i; 168 } 169 170 void fib6_info_destroy_rcu(struct rcu_head *head) 171 { 172 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu); 173 struct rt6_exception_bucket *bucket; 174 struct dst_metrics *m; 175 176 WARN_ON(f6i->fib6_node); 177 178 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1); 179 if (bucket) { 180 f6i->rt6i_exception_bucket = NULL; 181 kfree(bucket); 182 } 183 184 if (f6i->rt6i_pcpu) { 185 int cpu; 186 187 for_each_possible_cpu(cpu) { 188 struct rt6_info **ppcpu_rt; 189 struct rt6_info *pcpu_rt; 190 191 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 192 pcpu_rt = *ppcpu_rt; 193 if (pcpu_rt) { 194 dst_dev_put(&pcpu_rt->dst); 195 dst_release(&pcpu_rt->dst); 196 *ppcpu_rt = NULL; 197 } 198 } 199 } 200 201 if (f6i->fib6_nh.nh_dev) 202 dev_put(f6i->fib6_nh.nh_dev); 203 204 m = f6i->fib6_metrics; 205 if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt)) 206 kfree(m); 207 208 kfree(f6i); 209 } 210 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); 211 212 static struct fib6_node *node_alloc(struct net *net) 213 { 214 struct fib6_node *fn; 215 216 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 217 if (fn) 218 net->ipv6.rt6_stats->fib_nodes++; 219 220 return fn; 221 } 222 223 static void node_free_immediate(struct net *net, struct fib6_node *fn) 224 { 225 kmem_cache_free(fib6_node_kmem, fn); 226 net->ipv6.rt6_stats->fib_nodes--; 227 } 228 229 static void node_free_rcu(struct rcu_head *head) 230 { 231 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 232 233 kmem_cache_free(fib6_node_kmem, fn); 234 } 235 236 static void node_free(struct net *net, struct fib6_node *fn) 237 { 238 call_rcu(&fn->rcu, node_free_rcu); 239 net->ipv6.rt6_stats->fib_nodes--; 240 } 241 242 static void fib6_free_table(struct fib6_table *table) 243 { 244 inetpeer_invalidate_tree(&table->tb6_peers); 245 kfree(table); 246 } 247 248 static void fib6_link_table(struct net *net, struct fib6_table *tb) 249 { 250 unsigned int h; 251 252 /* 253 * Initialize table lock at a single place to give lockdep a key, 254 * tables aren't visible prior to being linked to the list. 255 */ 256 spin_lock_init(&tb->tb6_lock); 257 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 258 259 /* 260 * No protection necessary, this is the only list mutatation 261 * operation, tables never disappear once they exist. 262 */ 263 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 264 } 265 266 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 267 268 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 269 { 270 struct fib6_table *table; 271 272 table = kzalloc(sizeof(*table), GFP_ATOMIC); 273 if (table) { 274 table->tb6_id = id; 275 rcu_assign_pointer(table->tb6_root.leaf, 276 net->ipv6.fib6_null_entry); 277 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 278 inet_peer_base_init(&table->tb6_peers); 279 } 280 281 return table; 282 } 283 284 struct fib6_table *fib6_new_table(struct net *net, u32 id) 285 { 286 struct fib6_table *tb; 287 288 if (id == 0) 289 id = RT6_TABLE_MAIN; 290 tb = fib6_get_table(net, id); 291 if (tb) 292 return tb; 293 294 tb = fib6_alloc_table(net, id); 295 if (tb) 296 fib6_link_table(net, tb); 297 298 return tb; 299 } 300 EXPORT_SYMBOL_GPL(fib6_new_table); 301 302 struct fib6_table *fib6_get_table(struct net *net, u32 id) 303 { 304 struct fib6_table *tb; 305 struct hlist_head *head; 306 unsigned int h; 307 308 if (id == 0) 309 id = RT6_TABLE_MAIN; 310 h = id & (FIB6_TABLE_HASHSZ - 1); 311 rcu_read_lock(); 312 head = &net->ipv6.fib_table_hash[h]; 313 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 314 if (tb->tb6_id == id) { 315 rcu_read_unlock(); 316 return tb; 317 } 318 } 319 rcu_read_unlock(); 320 321 return NULL; 322 } 323 EXPORT_SYMBOL_GPL(fib6_get_table); 324 325 static void __net_init fib6_tables_init(struct net *net) 326 { 327 fib6_link_table(net, net->ipv6.fib6_main_tbl); 328 fib6_link_table(net, net->ipv6.fib6_local_tbl); 329 } 330 #else 331 332 struct fib6_table *fib6_new_table(struct net *net, u32 id) 333 { 334 return fib6_get_table(net, id); 335 } 336 337 struct fib6_table *fib6_get_table(struct net *net, u32 id) 338 { 339 return net->ipv6.fib6_main_tbl; 340 } 341 342 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 343 const struct sk_buff *skb, 344 int flags, pol_lookup_t lookup) 345 { 346 struct rt6_info *rt; 347 348 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 349 if (rt->dst.error == -EAGAIN) { 350 ip6_rt_put(rt); 351 rt = net->ipv6.ip6_null_entry; 352 dst_hold(&rt->dst); 353 } 354 355 return &rt->dst; 356 } 357 358 /* called with rcu lock held; no reference taken on fib6_info */ 359 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 360 int flags) 361 { 362 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags); 363 } 364 365 static void __net_init fib6_tables_init(struct net *net) 366 { 367 fib6_link_table(net, net->ipv6.fib6_main_tbl); 368 } 369 370 #endif 371 372 unsigned int fib6_tables_seq_read(struct net *net) 373 { 374 unsigned int h, fib_seq = 0; 375 376 rcu_read_lock(); 377 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 378 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 379 struct fib6_table *tb; 380 381 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 382 fib_seq += tb->fib_seq; 383 } 384 rcu_read_unlock(); 385 386 return fib_seq; 387 } 388 389 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 390 enum fib_event_type event_type, 391 struct fib6_info *rt) 392 { 393 struct fib6_entry_notifier_info info = { 394 .rt = rt, 395 }; 396 397 return call_fib6_notifier(nb, net, event_type, &info.info); 398 } 399 400 static int call_fib6_entry_notifiers(struct net *net, 401 enum fib_event_type event_type, 402 struct fib6_info *rt, 403 struct netlink_ext_ack *extack) 404 { 405 struct fib6_entry_notifier_info info = { 406 .info.extack = extack, 407 .rt = rt, 408 }; 409 410 rt->fib6_table->fib_seq++; 411 return call_fib6_notifiers(net, event_type, &info.info); 412 } 413 414 struct fib6_dump_arg { 415 struct net *net; 416 struct notifier_block *nb; 417 }; 418 419 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 420 { 421 if (rt == arg->net->ipv6.fib6_null_entry) 422 return; 423 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 424 } 425 426 static int fib6_node_dump(struct fib6_walker *w) 427 { 428 struct fib6_info *rt; 429 430 for_each_fib6_walker_rt(w) 431 fib6_rt_dump(rt, w->args); 432 w->leaf = NULL; 433 return 0; 434 } 435 436 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 437 struct fib6_walker *w) 438 { 439 w->root = &tb->tb6_root; 440 spin_lock_bh(&tb->tb6_lock); 441 fib6_walk(net, w); 442 spin_unlock_bh(&tb->tb6_lock); 443 } 444 445 /* Called with rcu_read_lock() */ 446 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 447 { 448 struct fib6_dump_arg arg; 449 struct fib6_walker *w; 450 unsigned int h; 451 452 w = kzalloc(sizeof(*w), GFP_ATOMIC); 453 if (!w) 454 return -ENOMEM; 455 456 w->func = fib6_node_dump; 457 arg.net = net; 458 arg.nb = nb; 459 w->args = &arg; 460 461 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 462 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 463 struct fib6_table *tb; 464 465 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 466 fib6_table_dump(net, tb, w); 467 } 468 469 kfree(w); 470 471 return 0; 472 } 473 474 static int fib6_dump_node(struct fib6_walker *w) 475 { 476 int res; 477 struct fib6_info *rt; 478 479 for_each_fib6_walker_rt(w) { 480 res = rt6_dump_route(rt, w->args); 481 if (res < 0) { 482 /* Frame is full, suspend walking */ 483 w->leaf = rt; 484 return 1; 485 } 486 487 /* Multipath routes are dumped in one route with the 488 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 489 * last sibling of this route (no need to dump the 490 * sibling routes again) 491 */ 492 if (rt->fib6_nsiblings) 493 rt = list_last_entry(&rt->fib6_siblings, 494 struct fib6_info, 495 fib6_siblings); 496 } 497 w->leaf = NULL; 498 return 0; 499 } 500 501 static void fib6_dump_end(struct netlink_callback *cb) 502 { 503 struct net *net = sock_net(cb->skb->sk); 504 struct fib6_walker *w = (void *)cb->args[2]; 505 506 if (w) { 507 if (cb->args[4]) { 508 cb->args[4] = 0; 509 fib6_walker_unlink(net, w); 510 } 511 cb->args[2] = 0; 512 kfree(w); 513 } 514 cb->done = (void *)cb->args[3]; 515 cb->args[1] = 3; 516 } 517 518 static int fib6_dump_done(struct netlink_callback *cb) 519 { 520 fib6_dump_end(cb); 521 return cb->done ? cb->done(cb) : 0; 522 } 523 524 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 525 struct netlink_callback *cb) 526 { 527 struct net *net = sock_net(skb->sk); 528 struct fib6_walker *w; 529 int res; 530 531 w = (void *)cb->args[2]; 532 w->root = &table->tb6_root; 533 534 if (cb->args[4] == 0) { 535 w->count = 0; 536 w->skip = 0; 537 538 spin_lock_bh(&table->tb6_lock); 539 res = fib6_walk(net, w); 540 spin_unlock_bh(&table->tb6_lock); 541 if (res > 0) { 542 cb->args[4] = 1; 543 cb->args[5] = w->root->fn_sernum; 544 } 545 } else { 546 if (cb->args[5] != w->root->fn_sernum) { 547 /* Begin at the root if the tree changed */ 548 cb->args[5] = w->root->fn_sernum; 549 w->state = FWS_INIT; 550 w->node = w->root; 551 w->skip = w->count; 552 } else 553 w->skip = 0; 554 555 spin_lock_bh(&table->tb6_lock); 556 res = fib6_walk_continue(w); 557 spin_unlock_bh(&table->tb6_lock); 558 if (res <= 0) { 559 fib6_walker_unlink(net, w); 560 cb->args[4] = 0; 561 } 562 } 563 564 return res; 565 } 566 567 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 568 { 569 struct net *net = sock_net(skb->sk); 570 unsigned int h, s_h; 571 unsigned int e = 0, s_e; 572 struct rt6_rtnl_dump_arg arg; 573 struct fib6_walker *w; 574 struct fib6_table *tb; 575 struct hlist_head *head; 576 int res = 0; 577 578 s_h = cb->args[0]; 579 s_e = cb->args[1]; 580 581 w = (void *)cb->args[2]; 582 if (!w) { 583 /* New dump: 584 * 585 * 1. hook callback destructor. 586 */ 587 cb->args[3] = (long)cb->done; 588 cb->done = fib6_dump_done; 589 590 /* 591 * 2. allocate and initialize walker. 592 */ 593 w = kzalloc(sizeof(*w), GFP_ATOMIC); 594 if (!w) 595 return -ENOMEM; 596 w->func = fib6_dump_node; 597 cb->args[2] = (long)w; 598 } 599 600 arg.skb = skb; 601 arg.cb = cb; 602 arg.net = net; 603 w->args = &arg; 604 605 rcu_read_lock(); 606 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 607 e = 0; 608 head = &net->ipv6.fib_table_hash[h]; 609 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 610 if (e < s_e) 611 goto next; 612 res = fib6_dump_table(tb, skb, cb); 613 if (res != 0) 614 goto out; 615 next: 616 e++; 617 } 618 } 619 out: 620 rcu_read_unlock(); 621 cb->args[1] = e; 622 cb->args[0] = h; 623 624 res = res < 0 ? res : skb->len; 625 if (res <= 0) 626 fib6_dump_end(cb); 627 return res; 628 } 629 630 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 631 { 632 if (!f6i) 633 return; 634 635 if (f6i->fib6_metrics == &dst_default_metrics) { 636 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 637 638 if (!p) 639 return; 640 641 refcount_set(&p->refcnt, 1); 642 f6i->fib6_metrics = p; 643 } 644 645 f6i->fib6_metrics->metrics[metric - 1] = val; 646 } 647 648 /* 649 * Routing Table 650 * 651 * return the appropriate node for a routing tree "add" operation 652 * by either creating and inserting or by returning an existing 653 * node. 654 */ 655 656 static struct fib6_node *fib6_add_1(struct net *net, 657 struct fib6_table *table, 658 struct fib6_node *root, 659 struct in6_addr *addr, int plen, 660 int offset, int allow_create, 661 int replace_required, 662 struct netlink_ext_ack *extack) 663 { 664 struct fib6_node *fn, *in, *ln; 665 struct fib6_node *pn = NULL; 666 struct rt6key *key; 667 int bit; 668 __be32 dir = 0; 669 670 RT6_TRACE("fib6_add_1\n"); 671 672 /* insert node in tree */ 673 674 fn = root; 675 676 do { 677 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 678 lockdep_is_held(&table->tb6_lock)); 679 key = (struct rt6key *)((u8 *)leaf + offset); 680 681 /* 682 * Prefix match 683 */ 684 if (plen < fn->fn_bit || 685 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 686 if (!allow_create) { 687 if (replace_required) { 688 NL_SET_ERR_MSG(extack, 689 "Can not replace route - no match found"); 690 pr_warn("Can't replace route, no match found\n"); 691 return ERR_PTR(-ENOENT); 692 } 693 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 694 } 695 goto insert_above; 696 } 697 698 /* 699 * Exact match ? 700 */ 701 702 if (plen == fn->fn_bit) { 703 /* clean up an intermediate node */ 704 if (!(fn->fn_flags & RTN_RTINFO)) { 705 RCU_INIT_POINTER(fn->leaf, NULL); 706 fib6_info_release(leaf); 707 /* remove null_entry in the root node */ 708 } else if (fn->fn_flags & RTN_TL_ROOT && 709 rcu_access_pointer(fn->leaf) == 710 net->ipv6.fib6_null_entry) { 711 RCU_INIT_POINTER(fn->leaf, NULL); 712 } 713 714 return fn; 715 } 716 717 /* 718 * We have more bits to go 719 */ 720 721 /* Try to walk down on tree. */ 722 dir = addr_bit_set(addr, fn->fn_bit); 723 pn = fn; 724 fn = dir ? 725 rcu_dereference_protected(fn->right, 726 lockdep_is_held(&table->tb6_lock)) : 727 rcu_dereference_protected(fn->left, 728 lockdep_is_held(&table->tb6_lock)); 729 } while (fn); 730 731 if (!allow_create) { 732 /* We should not create new node because 733 * NLM_F_REPLACE was specified without NLM_F_CREATE 734 * I assume it is safe to require NLM_F_CREATE when 735 * REPLACE flag is used! Later we may want to remove the 736 * check for replace_required, because according 737 * to netlink specification, NLM_F_CREATE 738 * MUST be specified if new route is created. 739 * That would keep IPv6 consistent with IPv4 740 */ 741 if (replace_required) { 742 NL_SET_ERR_MSG(extack, 743 "Can not replace route - no match found"); 744 pr_warn("Can't replace route, no match found\n"); 745 return ERR_PTR(-ENOENT); 746 } 747 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 748 } 749 /* 750 * We walked to the bottom of tree. 751 * Create new leaf node without children. 752 */ 753 754 ln = node_alloc(net); 755 756 if (!ln) 757 return ERR_PTR(-ENOMEM); 758 ln->fn_bit = plen; 759 RCU_INIT_POINTER(ln->parent, pn); 760 761 if (dir) 762 rcu_assign_pointer(pn->right, ln); 763 else 764 rcu_assign_pointer(pn->left, ln); 765 766 return ln; 767 768 769 insert_above: 770 /* 771 * split since we don't have a common prefix anymore or 772 * we have a less significant route. 773 * we've to insert an intermediate node on the list 774 * this new node will point to the one we need to create 775 * and the current 776 */ 777 778 pn = rcu_dereference_protected(fn->parent, 779 lockdep_is_held(&table->tb6_lock)); 780 781 /* find 1st bit in difference between the 2 addrs. 782 783 See comment in __ipv6_addr_diff: bit may be an invalid value, 784 but if it is >= plen, the value is ignored in any case. 785 */ 786 787 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 788 789 /* 790 * (intermediate)[in] 791 * / \ 792 * (new leaf node)[ln] (old node)[fn] 793 */ 794 if (plen > bit) { 795 in = node_alloc(net); 796 ln = node_alloc(net); 797 798 if (!in || !ln) { 799 if (in) 800 node_free_immediate(net, in); 801 if (ln) 802 node_free_immediate(net, ln); 803 return ERR_PTR(-ENOMEM); 804 } 805 806 /* 807 * new intermediate node. 808 * RTN_RTINFO will 809 * be off since that an address that chooses one of 810 * the branches would not match less specific routes 811 * in the other branch 812 */ 813 814 in->fn_bit = bit; 815 816 RCU_INIT_POINTER(in->parent, pn); 817 in->leaf = fn->leaf; 818 atomic_inc(&rcu_dereference_protected(in->leaf, 819 lockdep_is_held(&table->tb6_lock))->fib6_ref); 820 821 /* update parent pointer */ 822 if (dir) 823 rcu_assign_pointer(pn->right, in); 824 else 825 rcu_assign_pointer(pn->left, in); 826 827 ln->fn_bit = plen; 828 829 RCU_INIT_POINTER(ln->parent, in); 830 rcu_assign_pointer(fn->parent, in); 831 832 if (addr_bit_set(addr, bit)) { 833 rcu_assign_pointer(in->right, ln); 834 rcu_assign_pointer(in->left, fn); 835 } else { 836 rcu_assign_pointer(in->left, ln); 837 rcu_assign_pointer(in->right, fn); 838 } 839 } else { /* plen <= bit */ 840 841 /* 842 * (new leaf node)[ln] 843 * / \ 844 * (old node)[fn] NULL 845 */ 846 847 ln = node_alloc(net); 848 849 if (!ln) 850 return ERR_PTR(-ENOMEM); 851 852 ln->fn_bit = plen; 853 854 RCU_INIT_POINTER(ln->parent, pn); 855 856 if (addr_bit_set(&key->addr, plen)) 857 RCU_INIT_POINTER(ln->right, fn); 858 else 859 RCU_INIT_POINTER(ln->left, fn); 860 861 rcu_assign_pointer(fn->parent, ln); 862 863 if (dir) 864 rcu_assign_pointer(pn->right, ln); 865 else 866 rcu_assign_pointer(pn->left, ln); 867 } 868 return ln; 869 } 870 871 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 872 const struct fib6_table *table) 873 { 874 int cpu; 875 876 /* release the reference to this fib entry from 877 * all of its cached pcpu routes 878 */ 879 for_each_possible_cpu(cpu) { 880 struct rt6_info **ppcpu_rt; 881 struct rt6_info *pcpu_rt; 882 883 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 884 pcpu_rt = *ppcpu_rt; 885 if (pcpu_rt) { 886 struct fib6_info *from; 887 888 from = rcu_dereference_protected(pcpu_rt->from, 889 lockdep_is_held(&table->tb6_lock)); 890 rcu_assign_pointer(pcpu_rt->from, NULL); 891 fib6_info_release(from); 892 } 893 } 894 } 895 896 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 897 struct net *net) 898 { 899 struct fib6_table *table = rt->fib6_table; 900 901 if (atomic_read(&rt->fib6_ref) != 1) { 902 /* This route is used as dummy address holder in some split 903 * nodes. It is not leaked, but it still holds other resources, 904 * which must be released in time. So, scan ascendant nodes 905 * and replace dummy references to this route with references 906 * to still alive ones. 907 */ 908 while (fn) { 909 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 910 lockdep_is_held(&table->tb6_lock)); 911 struct fib6_info *new_leaf; 912 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 913 new_leaf = fib6_find_prefix(net, table, fn); 914 atomic_inc(&new_leaf->fib6_ref); 915 916 rcu_assign_pointer(fn->leaf, new_leaf); 917 fib6_info_release(rt); 918 } 919 fn = rcu_dereference_protected(fn->parent, 920 lockdep_is_held(&table->tb6_lock)); 921 } 922 923 if (rt->rt6i_pcpu) 924 fib6_drop_pcpu_from(rt, table); 925 } 926 } 927 928 /* 929 * Insert routing information in a node. 930 */ 931 932 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 933 struct nl_info *info, 934 struct netlink_ext_ack *extack) 935 { 936 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 937 lockdep_is_held(&rt->fib6_table->tb6_lock)); 938 enum fib_event_type event = FIB_EVENT_ENTRY_ADD; 939 struct fib6_info *iter = NULL, *match = NULL; 940 struct fib6_info __rcu **ins; 941 int replace = (info->nlh && 942 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 943 int append = (info->nlh && 944 (info->nlh->nlmsg_flags & NLM_F_APPEND)); 945 int add = (!info->nlh || 946 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 947 int found = 0; 948 u16 nlflags = NLM_F_EXCL; 949 int err; 950 951 if (append) 952 nlflags |= NLM_F_APPEND; 953 954 ins = &fn->leaf; 955 956 for (iter = leaf; iter; 957 iter = rcu_dereference_protected(iter->fib6_next, 958 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 959 /* 960 * Search for duplicates 961 */ 962 963 if (iter->fib6_metric == rt->fib6_metric) { 964 /* 965 * Same priority level 966 */ 967 if (info->nlh && 968 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 969 return -EEXIST; 970 971 nlflags &= ~NLM_F_EXCL; 972 if (replace) { 973 found++; 974 break; 975 } 976 977 if (rt6_duplicate_nexthop(iter, rt)) { 978 if (rt->fib6_nsiblings) 979 rt->fib6_nsiblings = 0; 980 if (!(iter->fib6_flags & RTF_EXPIRES)) 981 return -EEXIST; 982 if (!(rt->fib6_flags & RTF_EXPIRES)) 983 fib6_clean_expires(iter); 984 else 985 fib6_set_expires(iter, rt->expires); 986 fib6_metric_set(iter, RTAX_MTU, rt->fib6_pmtu); 987 return -EEXIST; 988 } 989 990 /* first route that matches */ 991 if (!match) 992 match = iter; 993 } 994 995 if (iter->fib6_metric > rt->fib6_metric) 996 break; 997 998 ins = &iter->fib6_next; 999 } 1000 1001 /* Reset round-robin state, if necessary */ 1002 if (ins == &fn->leaf) 1003 fn->rr_ptr = NULL; 1004 1005 /* Link this route to others same route. */ 1006 if (append && match) { 1007 struct fib6_info *sibling, *temp_sibling; 1008 1009 if (rt->fib6_flags & RTF_REJECT) { 1010 NL_SET_ERR_MSG(extack, 1011 "Can not append a REJECT route"); 1012 return -EINVAL; 1013 } else if (match->fib6_flags & RTF_REJECT) { 1014 NL_SET_ERR_MSG(extack, 1015 "Can not append to a REJECT route"); 1016 return -EINVAL; 1017 } 1018 event = FIB_EVENT_ENTRY_APPEND; 1019 rt->fib6_nsiblings = match->fib6_nsiblings; 1020 list_add_tail(&rt->fib6_siblings, &match->fib6_siblings); 1021 match->fib6_nsiblings++; 1022 1023 /* For each sibling in the list, increment the counter of 1024 * siblings. BUG() if counters does not match, list of siblings 1025 * is broken! 1026 */ 1027 list_for_each_entry_safe(sibling, temp_sibling, 1028 &match->fib6_siblings, fib6_siblings) { 1029 sibling->fib6_nsiblings++; 1030 BUG_ON(sibling->fib6_nsiblings != match->fib6_nsiblings); 1031 } 1032 1033 rt6_multipath_rebalance(match); 1034 } 1035 1036 /* 1037 * insert node 1038 */ 1039 if (!replace) { 1040 if (!add) 1041 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1042 1043 add: 1044 nlflags |= NLM_F_CREATE; 1045 1046 err = call_fib6_entry_notifiers(info->nl_net, event, rt, 1047 extack); 1048 if (err) 1049 return err; 1050 1051 rcu_assign_pointer(rt->fib6_next, iter); 1052 atomic_inc(&rt->fib6_ref); 1053 rcu_assign_pointer(rt->fib6_node, fn); 1054 rcu_assign_pointer(*ins, rt); 1055 if (!info->skip_notify) 1056 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1057 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1058 1059 if (!(fn->fn_flags & RTN_RTINFO)) { 1060 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1061 fn->fn_flags |= RTN_RTINFO; 1062 } 1063 1064 } else { 1065 struct fib6_info *tmp; 1066 1067 if (!found) { 1068 if (add) 1069 goto add; 1070 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1071 return -ENOENT; 1072 } 1073 1074 err = call_fib6_entry_notifiers(info->nl_net, 1075 FIB_EVENT_ENTRY_REPLACE, 1076 rt, extack); 1077 if (err) 1078 return err; 1079 1080 /* if route being replaced has siblings, set tmp to 1081 * last one, otherwise tmp is current route. this is 1082 * used to set fib6_next for new route 1083 */ 1084 if (iter->fib6_nsiblings) 1085 tmp = list_last_entry(&iter->fib6_siblings, 1086 struct fib6_info, 1087 fib6_siblings); 1088 else 1089 tmp = iter; 1090 1091 /* insert new route */ 1092 atomic_inc(&rt->fib6_ref); 1093 rcu_assign_pointer(rt->fib6_node, fn); 1094 rt->fib6_next = tmp->fib6_next; 1095 rcu_assign_pointer(*ins, rt); 1096 1097 if (!info->skip_notify) 1098 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1099 if (!(fn->fn_flags & RTN_RTINFO)) { 1100 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1101 fn->fn_flags |= RTN_RTINFO; 1102 } 1103 1104 /* delete old route */ 1105 rt = iter; 1106 1107 if (rt->fib6_nsiblings) { 1108 struct fib6_info *tmp; 1109 1110 /* Replacing an ECMP route, remove all siblings */ 1111 list_for_each_entry_safe(iter, tmp, &rt->fib6_siblings, 1112 fib6_siblings) { 1113 iter->fib6_node = NULL; 1114 fib6_purge_rt(iter, fn, info->nl_net); 1115 if (rcu_access_pointer(fn->rr_ptr) == iter) 1116 fn->rr_ptr = NULL; 1117 fib6_info_release(iter); 1118 1119 rt->fib6_nsiblings--; 1120 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1121 } 1122 } 1123 1124 WARN_ON(rt->fib6_nsiblings != 0); 1125 1126 rt->fib6_node = NULL; 1127 fib6_purge_rt(rt, fn, info->nl_net); 1128 if (rcu_access_pointer(fn->rr_ptr) == rt) 1129 fn->rr_ptr = NULL; 1130 fib6_info_release(rt); 1131 } 1132 1133 return 0; 1134 } 1135 1136 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1137 { 1138 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1139 (rt->fib6_flags & RTF_EXPIRES)) 1140 mod_timer(&net->ipv6.ip6_fib_timer, 1141 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1142 } 1143 1144 void fib6_force_start_gc(struct net *net) 1145 { 1146 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1147 mod_timer(&net->ipv6.ip6_fib_timer, 1148 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1149 } 1150 1151 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1152 int sernum) 1153 { 1154 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1155 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1156 1157 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1158 smp_wmb(); 1159 while (fn) { 1160 fn->fn_sernum = sernum; 1161 fn = rcu_dereference_protected(fn->parent, 1162 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1163 } 1164 } 1165 1166 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1167 { 1168 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1169 } 1170 1171 /* 1172 * Add routing information to the routing tree. 1173 * <destination addr>/<source addr> 1174 * with source addr info in sub-trees 1175 * Need to own table->tb6_lock 1176 */ 1177 1178 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1179 struct nl_info *info, struct netlink_ext_ack *extack) 1180 { 1181 struct fib6_table *table = rt->fib6_table; 1182 struct fib6_node *fn, *pn = NULL; 1183 int err = -ENOMEM; 1184 int allow_create = 1; 1185 int replace_required = 0; 1186 int sernum = fib6_new_sernum(info->nl_net); 1187 1188 if (info->nlh) { 1189 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1190 allow_create = 0; 1191 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1192 replace_required = 1; 1193 } 1194 if (!allow_create && !replace_required) 1195 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1196 1197 fn = fib6_add_1(info->nl_net, table, root, 1198 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1199 offsetof(struct fib6_info, fib6_dst), allow_create, 1200 replace_required, extack); 1201 if (IS_ERR(fn)) { 1202 err = PTR_ERR(fn); 1203 fn = NULL; 1204 goto out; 1205 } 1206 1207 pn = fn; 1208 1209 #ifdef CONFIG_IPV6_SUBTREES 1210 if (rt->fib6_src.plen) { 1211 struct fib6_node *sn; 1212 1213 if (!rcu_access_pointer(fn->subtree)) { 1214 struct fib6_node *sfn; 1215 1216 /* 1217 * Create subtree. 1218 * 1219 * fn[main tree] 1220 * | 1221 * sfn[subtree root] 1222 * \ 1223 * sn[new leaf node] 1224 */ 1225 1226 /* Create subtree root node */ 1227 sfn = node_alloc(info->nl_net); 1228 if (!sfn) 1229 goto failure; 1230 1231 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref); 1232 rcu_assign_pointer(sfn->leaf, 1233 info->nl_net->ipv6.fib6_null_entry); 1234 sfn->fn_flags = RTN_ROOT; 1235 1236 /* Now add the first leaf node to new subtree */ 1237 1238 sn = fib6_add_1(info->nl_net, table, sfn, 1239 &rt->fib6_src.addr, rt->fib6_src.plen, 1240 offsetof(struct fib6_info, fib6_src), 1241 allow_create, replace_required, extack); 1242 1243 if (IS_ERR(sn)) { 1244 /* If it is failed, discard just allocated 1245 root, and then (in failure) stale node 1246 in main tree. 1247 */ 1248 node_free_immediate(info->nl_net, sfn); 1249 err = PTR_ERR(sn); 1250 goto failure; 1251 } 1252 1253 /* Now link new subtree to main tree */ 1254 rcu_assign_pointer(sfn->parent, fn); 1255 rcu_assign_pointer(fn->subtree, sfn); 1256 } else { 1257 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1258 &rt->fib6_src.addr, rt->fib6_src.plen, 1259 offsetof(struct fib6_info, fib6_src), 1260 allow_create, replace_required, extack); 1261 1262 if (IS_ERR(sn)) { 1263 err = PTR_ERR(sn); 1264 goto failure; 1265 } 1266 } 1267 1268 if (!rcu_access_pointer(fn->leaf)) { 1269 if (fn->fn_flags & RTN_TL_ROOT) { 1270 /* put back null_entry for root node */ 1271 rcu_assign_pointer(fn->leaf, 1272 info->nl_net->ipv6.fib6_null_entry); 1273 } else { 1274 atomic_inc(&rt->fib6_ref); 1275 rcu_assign_pointer(fn->leaf, rt); 1276 } 1277 } 1278 fn = sn; 1279 } 1280 #endif 1281 1282 err = fib6_add_rt2node(fn, rt, info, extack); 1283 if (!err) { 1284 __fib6_update_sernum_upto_root(rt, sernum); 1285 fib6_start_gc(info->nl_net, rt); 1286 } 1287 1288 out: 1289 if (err) { 1290 #ifdef CONFIG_IPV6_SUBTREES 1291 /* 1292 * If fib6_add_1 has cleared the old leaf pointer in the 1293 * super-tree leaf node we have to find a new one for it. 1294 */ 1295 if (pn != fn) { 1296 struct fib6_info *pn_leaf = 1297 rcu_dereference_protected(pn->leaf, 1298 lockdep_is_held(&table->tb6_lock)); 1299 if (pn_leaf == rt) { 1300 pn_leaf = NULL; 1301 RCU_INIT_POINTER(pn->leaf, NULL); 1302 fib6_info_release(rt); 1303 } 1304 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1305 pn_leaf = fib6_find_prefix(info->nl_net, table, 1306 pn); 1307 #if RT6_DEBUG >= 2 1308 if (!pn_leaf) { 1309 WARN_ON(!pn_leaf); 1310 pn_leaf = 1311 info->nl_net->ipv6.fib6_null_entry; 1312 } 1313 #endif 1314 fib6_info_hold(pn_leaf); 1315 rcu_assign_pointer(pn->leaf, pn_leaf); 1316 } 1317 } 1318 #endif 1319 goto failure; 1320 } 1321 return err; 1322 1323 failure: 1324 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1325 * 1. fn is an intermediate node and we failed to add the new 1326 * route to it in both subtree creation failure and fib6_add_rt2node() 1327 * failure case. 1328 * 2. fn is the root node in the table and we fail to add the first 1329 * default route to it. 1330 */ 1331 if (fn && 1332 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1333 (fn->fn_flags & RTN_TL_ROOT && 1334 !rcu_access_pointer(fn->leaf)))) 1335 fib6_repair_tree(info->nl_net, table, fn); 1336 return err; 1337 } 1338 1339 /* 1340 * Routing tree lookup 1341 * 1342 */ 1343 1344 struct lookup_args { 1345 int offset; /* key offset on fib6_info */ 1346 const struct in6_addr *addr; /* search key */ 1347 }; 1348 1349 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1350 struct lookup_args *args) 1351 { 1352 struct fib6_node *fn; 1353 __be32 dir; 1354 1355 if (unlikely(args->offset == 0)) 1356 return NULL; 1357 1358 /* 1359 * Descend on a tree 1360 */ 1361 1362 fn = root; 1363 1364 for (;;) { 1365 struct fib6_node *next; 1366 1367 dir = addr_bit_set(args->addr, fn->fn_bit); 1368 1369 next = dir ? rcu_dereference(fn->right) : 1370 rcu_dereference(fn->left); 1371 1372 if (next) { 1373 fn = next; 1374 continue; 1375 } 1376 break; 1377 } 1378 1379 while (fn) { 1380 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1381 1382 if (subtree || fn->fn_flags & RTN_RTINFO) { 1383 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1384 struct rt6key *key; 1385 1386 if (!leaf) 1387 goto backtrack; 1388 1389 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1390 1391 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1392 #ifdef CONFIG_IPV6_SUBTREES 1393 if (subtree) { 1394 struct fib6_node *sfn; 1395 sfn = fib6_node_lookup_1(subtree, 1396 args + 1); 1397 if (!sfn) 1398 goto backtrack; 1399 fn = sfn; 1400 } 1401 #endif 1402 if (fn->fn_flags & RTN_RTINFO) 1403 return fn; 1404 } 1405 } 1406 backtrack: 1407 if (fn->fn_flags & RTN_ROOT) 1408 break; 1409 1410 fn = rcu_dereference(fn->parent); 1411 } 1412 1413 return NULL; 1414 } 1415 1416 /* called with rcu_read_lock() held 1417 */ 1418 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1419 const struct in6_addr *daddr, 1420 const struct in6_addr *saddr) 1421 { 1422 struct fib6_node *fn; 1423 struct lookup_args args[] = { 1424 { 1425 .offset = offsetof(struct fib6_info, fib6_dst), 1426 .addr = daddr, 1427 }, 1428 #ifdef CONFIG_IPV6_SUBTREES 1429 { 1430 .offset = offsetof(struct fib6_info, fib6_src), 1431 .addr = saddr, 1432 }, 1433 #endif 1434 { 1435 .offset = 0, /* sentinel */ 1436 } 1437 }; 1438 1439 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1440 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1441 fn = root; 1442 1443 return fn; 1444 } 1445 1446 /* 1447 * Get node with specified destination prefix (and source prefix, 1448 * if subtrees are used) 1449 * exact_match == true means we try to find fn with exact match of 1450 * the passed in prefix addr 1451 * exact_match == false means we try to find fn with longest prefix 1452 * match of the passed in prefix addr. This is useful for finding fn 1453 * for cached route as it will be stored in the exception table under 1454 * the node with longest prefix length. 1455 */ 1456 1457 1458 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1459 const struct in6_addr *addr, 1460 int plen, int offset, 1461 bool exact_match) 1462 { 1463 struct fib6_node *fn, *prev = NULL; 1464 1465 for (fn = root; fn ; ) { 1466 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1467 struct rt6key *key; 1468 1469 /* This node is being deleted */ 1470 if (!leaf) { 1471 if (plen <= fn->fn_bit) 1472 goto out; 1473 else 1474 goto next; 1475 } 1476 1477 key = (struct rt6key *)((u8 *)leaf + offset); 1478 1479 /* 1480 * Prefix match 1481 */ 1482 if (plen < fn->fn_bit || 1483 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1484 goto out; 1485 1486 if (plen == fn->fn_bit) 1487 return fn; 1488 1489 prev = fn; 1490 1491 next: 1492 /* 1493 * We have more bits to go 1494 */ 1495 if (addr_bit_set(addr, fn->fn_bit)) 1496 fn = rcu_dereference(fn->right); 1497 else 1498 fn = rcu_dereference(fn->left); 1499 } 1500 out: 1501 if (exact_match) 1502 return NULL; 1503 else 1504 return prev; 1505 } 1506 1507 struct fib6_node *fib6_locate(struct fib6_node *root, 1508 const struct in6_addr *daddr, int dst_len, 1509 const struct in6_addr *saddr, int src_len, 1510 bool exact_match) 1511 { 1512 struct fib6_node *fn; 1513 1514 fn = fib6_locate_1(root, daddr, dst_len, 1515 offsetof(struct fib6_info, fib6_dst), 1516 exact_match); 1517 1518 #ifdef CONFIG_IPV6_SUBTREES 1519 if (src_len) { 1520 WARN_ON(saddr == NULL); 1521 if (fn) { 1522 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1523 1524 if (subtree) { 1525 fn = fib6_locate_1(subtree, saddr, src_len, 1526 offsetof(struct fib6_info, fib6_src), 1527 exact_match); 1528 } 1529 } 1530 } 1531 #endif 1532 1533 if (fn && fn->fn_flags & RTN_RTINFO) 1534 return fn; 1535 1536 return NULL; 1537 } 1538 1539 1540 /* 1541 * Deletion 1542 * 1543 */ 1544 1545 static struct fib6_info *fib6_find_prefix(struct net *net, 1546 struct fib6_table *table, 1547 struct fib6_node *fn) 1548 { 1549 struct fib6_node *child_left, *child_right; 1550 1551 if (fn->fn_flags & RTN_ROOT) 1552 return net->ipv6.fib6_null_entry; 1553 1554 while (fn) { 1555 child_left = rcu_dereference_protected(fn->left, 1556 lockdep_is_held(&table->tb6_lock)); 1557 child_right = rcu_dereference_protected(fn->right, 1558 lockdep_is_held(&table->tb6_lock)); 1559 if (child_left) 1560 return rcu_dereference_protected(child_left->leaf, 1561 lockdep_is_held(&table->tb6_lock)); 1562 if (child_right) 1563 return rcu_dereference_protected(child_right->leaf, 1564 lockdep_is_held(&table->tb6_lock)); 1565 1566 fn = FIB6_SUBTREE(fn); 1567 } 1568 return NULL; 1569 } 1570 1571 /* 1572 * Called to trim the tree of intermediate nodes when possible. "fn" 1573 * is the node we want to try and remove. 1574 * Need to own table->tb6_lock 1575 */ 1576 1577 static struct fib6_node *fib6_repair_tree(struct net *net, 1578 struct fib6_table *table, 1579 struct fib6_node *fn) 1580 { 1581 int children; 1582 int nstate; 1583 struct fib6_node *child; 1584 struct fib6_walker *w; 1585 int iter = 0; 1586 1587 /* Set fn->leaf to null_entry for root node. */ 1588 if (fn->fn_flags & RTN_TL_ROOT) { 1589 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1590 return fn; 1591 } 1592 1593 for (;;) { 1594 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1595 lockdep_is_held(&table->tb6_lock)); 1596 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1597 lockdep_is_held(&table->tb6_lock)); 1598 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1599 lockdep_is_held(&table->tb6_lock)); 1600 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1601 lockdep_is_held(&table->tb6_lock)); 1602 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1603 lockdep_is_held(&table->tb6_lock)); 1604 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1605 lockdep_is_held(&table->tb6_lock)); 1606 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1607 lockdep_is_held(&table->tb6_lock)); 1608 struct fib6_info *new_fn_leaf; 1609 1610 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1611 iter++; 1612 1613 WARN_ON(fn->fn_flags & RTN_RTINFO); 1614 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1615 WARN_ON(fn_leaf); 1616 1617 children = 0; 1618 child = NULL; 1619 if (fn_r) 1620 child = fn_r, children |= 1; 1621 if (fn_l) 1622 child = fn_l, children |= 2; 1623 1624 if (children == 3 || FIB6_SUBTREE(fn) 1625 #ifdef CONFIG_IPV6_SUBTREES 1626 /* Subtree root (i.e. fn) may have one child */ 1627 || (children && fn->fn_flags & RTN_ROOT) 1628 #endif 1629 ) { 1630 new_fn_leaf = fib6_find_prefix(net, table, fn); 1631 #if RT6_DEBUG >= 2 1632 if (!new_fn_leaf) { 1633 WARN_ON(!new_fn_leaf); 1634 new_fn_leaf = net->ipv6.fib6_null_entry; 1635 } 1636 #endif 1637 fib6_info_hold(new_fn_leaf); 1638 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1639 return pn; 1640 } 1641 1642 #ifdef CONFIG_IPV6_SUBTREES 1643 if (FIB6_SUBTREE(pn) == fn) { 1644 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1645 RCU_INIT_POINTER(pn->subtree, NULL); 1646 nstate = FWS_L; 1647 } else { 1648 WARN_ON(fn->fn_flags & RTN_ROOT); 1649 #endif 1650 if (pn_r == fn) 1651 rcu_assign_pointer(pn->right, child); 1652 else if (pn_l == fn) 1653 rcu_assign_pointer(pn->left, child); 1654 #if RT6_DEBUG >= 2 1655 else 1656 WARN_ON(1); 1657 #endif 1658 if (child) 1659 rcu_assign_pointer(child->parent, pn); 1660 nstate = FWS_R; 1661 #ifdef CONFIG_IPV6_SUBTREES 1662 } 1663 #endif 1664 1665 read_lock(&net->ipv6.fib6_walker_lock); 1666 FOR_WALKERS(net, w) { 1667 if (!child) { 1668 if (w->node == fn) { 1669 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1670 w->node = pn; 1671 w->state = nstate; 1672 } 1673 } else { 1674 if (w->node == fn) { 1675 w->node = child; 1676 if (children&2) { 1677 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1678 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1679 } else { 1680 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1681 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1682 } 1683 } 1684 } 1685 } 1686 read_unlock(&net->ipv6.fib6_walker_lock); 1687 1688 node_free(net, fn); 1689 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1690 return pn; 1691 1692 RCU_INIT_POINTER(pn->leaf, NULL); 1693 fib6_info_release(pn_leaf); 1694 fn = pn; 1695 } 1696 } 1697 1698 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1699 struct fib6_info __rcu **rtp, struct nl_info *info) 1700 { 1701 struct fib6_walker *w; 1702 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1703 lockdep_is_held(&table->tb6_lock)); 1704 struct net *net = info->nl_net; 1705 1706 RT6_TRACE("fib6_del_route\n"); 1707 1708 /* Unlink it */ 1709 *rtp = rt->fib6_next; 1710 rt->fib6_node = NULL; 1711 net->ipv6.rt6_stats->fib_rt_entries--; 1712 net->ipv6.rt6_stats->fib_discarded_routes++; 1713 1714 /* Flush all cached dst in exception table */ 1715 rt6_flush_exceptions(rt); 1716 1717 /* Reset round-robin state, if necessary */ 1718 if (rcu_access_pointer(fn->rr_ptr) == rt) 1719 fn->rr_ptr = NULL; 1720 1721 /* Remove this entry from other siblings */ 1722 if (rt->fib6_nsiblings) { 1723 struct fib6_info *sibling, *next_sibling; 1724 1725 list_for_each_entry_safe(sibling, next_sibling, 1726 &rt->fib6_siblings, fib6_siblings) 1727 sibling->fib6_nsiblings--; 1728 rt->fib6_nsiblings = 0; 1729 list_del_init(&rt->fib6_siblings); 1730 rt6_multipath_rebalance(next_sibling); 1731 } 1732 1733 /* Adjust walkers */ 1734 read_lock(&net->ipv6.fib6_walker_lock); 1735 FOR_WALKERS(net, w) { 1736 if (w->state == FWS_C && w->leaf == rt) { 1737 RT6_TRACE("walker %p adjusted by delroute\n", w); 1738 w->leaf = rcu_dereference_protected(rt->fib6_next, 1739 lockdep_is_held(&table->tb6_lock)); 1740 if (!w->leaf) 1741 w->state = FWS_U; 1742 } 1743 } 1744 read_unlock(&net->ipv6.fib6_walker_lock); 1745 1746 /* If it was last route, call fib6_repair_tree() to: 1747 * 1. For root node, put back null_entry as how the table was created. 1748 * 2. For other nodes, expunge its radix tree node. 1749 */ 1750 if (!rcu_access_pointer(fn->leaf)) { 1751 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1752 fn->fn_flags &= ~RTN_RTINFO; 1753 net->ipv6.rt6_stats->fib_route_nodes--; 1754 } 1755 fn = fib6_repair_tree(net, table, fn); 1756 } 1757 1758 fib6_purge_rt(rt, fn, net); 1759 1760 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1761 if (!info->skip_notify) 1762 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1763 fib6_info_release(rt); 1764 } 1765 1766 /* Need to own table->tb6_lock */ 1767 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1768 { 1769 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1770 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1771 struct fib6_table *table = rt->fib6_table; 1772 struct net *net = info->nl_net; 1773 struct fib6_info __rcu **rtp; 1774 struct fib6_info __rcu **rtp_next; 1775 1776 if (!fn || rt == net->ipv6.fib6_null_entry) 1777 return -ENOENT; 1778 1779 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1780 1781 /* 1782 * Walk the leaf entries looking for ourself 1783 */ 1784 1785 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1786 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1787 lockdep_is_held(&table->tb6_lock)); 1788 if (rt == cur) { 1789 fib6_del_route(table, fn, rtp, info); 1790 return 0; 1791 } 1792 rtp_next = &cur->fib6_next; 1793 } 1794 return -ENOENT; 1795 } 1796 1797 /* 1798 * Tree traversal function. 1799 * 1800 * Certainly, it is not interrupt safe. 1801 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1802 * It means, that we can modify tree during walking 1803 * and use this function for garbage collection, clone pruning, 1804 * cleaning tree when a device goes down etc. etc. 1805 * 1806 * It guarantees that every node will be traversed, 1807 * and that it will be traversed only once. 1808 * 1809 * Callback function w->func may return: 1810 * 0 -> continue walking. 1811 * positive value -> walking is suspended (used by tree dumps, 1812 * and probably by gc, if it will be split to several slices) 1813 * negative value -> terminate walking. 1814 * 1815 * The function itself returns: 1816 * 0 -> walk is complete. 1817 * >0 -> walk is incomplete (i.e. suspended) 1818 * <0 -> walk is terminated by an error. 1819 * 1820 * This function is called with tb6_lock held. 1821 */ 1822 1823 static int fib6_walk_continue(struct fib6_walker *w) 1824 { 1825 struct fib6_node *fn, *pn, *left, *right; 1826 1827 /* w->root should always be table->tb6_root */ 1828 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1829 1830 for (;;) { 1831 fn = w->node; 1832 if (!fn) 1833 return 0; 1834 1835 switch (w->state) { 1836 #ifdef CONFIG_IPV6_SUBTREES 1837 case FWS_S: 1838 if (FIB6_SUBTREE(fn)) { 1839 w->node = FIB6_SUBTREE(fn); 1840 continue; 1841 } 1842 w->state = FWS_L; 1843 #endif 1844 /* fall through */ 1845 case FWS_L: 1846 left = rcu_dereference_protected(fn->left, 1); 1847 if (left) { 1848 w->node = left; 1849 w->state = FWS_INIT; 1850 continue; 1851 } 1852 w->state = FWS_R; 1853 /* fall through */ 1854 case FWS_R: 1855 right = rcu_dereference_protected(fn->right, 1); 1856 if (right) { 1857 w->node = right; 1858 w->state = FWS_INIT; 1859 continue; 1860 } 1861 w->state = FWS_C; 1862 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1863 /* fall through */ 1864 case FWS_C: 1865 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1866 int err; 1867 1868 if (w->skip) { 1869 w->skip--; 1870 goto skip; 1871 } 1872 1873 err = w->func(w); 1874 if (err) 1875 return err; 1876 1877 w->count++; 1878 continue; 1879 } 1880 skip: 1881 w->state = FWS_U; 1882 /* fall through */ 1883 case FWS_U: 1884 if (fn == w->root) 1885 return 0; 1886 pn = rcu_dereference_protected(fn->parent, 1); 1887 left = rcu_dereference_protected(pn->left, 1); 1888 right = rcu_dereference_protected(pn->right, 1); 1889 w->node = pn; 1890 #ifdef CONFIG_IPV6_SUBTREES 1891 if (FIB6_SUBTREE(pn) == fn) { 1892 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1893 w->state = FWS_L; 1894 continue; 1895 } 1896 #endif 1897 if (left == fn) { 1898 w->state = FWS_R; 1899 continue; 1900 } 1901 if (right == fn) { 1902 w->state = FWS_C; 1903 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1904 continue; 1905 } 1906 #if RT6_DEBUG >= 2 1907 WARN_ON(1); 1908 #endif 1909 } 1910 } 1911 } 1912 1913 static int fib6_walk(struct net *net, struct fib6_walker *w) 1914 { 1915 int res; 1916 1917 w->state = FWS_INIT; 1918 w->node = w->root; 1919 1920 fib6_walker_link(net, w); 1921 res = fib6_walk_continue(w); 1922 if (res <= 0) 1923 fib6_walker_unlink(net, w); 1924 return res; 1925 } 1926 1927 static int fib6_clean_node(struct fib6_walker *w) 1928 { 1929 int res; 1930 struct fib6_info *rt; 1931 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1932 struct nl_info info = { 1933 .nl_net = c->net, 1934 }; 1935 1936 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1937 w->node->fn_sernum != c->sernum) 1938 w->node->fn_sernum = c->sernum; 1939 1940 if (!c->func) { 1941 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1942 w->leaf = NULL; 1943 return 0; 1944 } 1945 1946 for_each_fib6_walker_rt(w) { 1947 res = c->func(rt, c->arg); 1948 if (res == -1) { 1949 w->leaf = rt; 1950 res = fib6_del(rt, &info); 1951 if (res) { 1952 #if RT6_DEBUG >= 2 1953 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1954 __func__, rt, 1955 rcu_access_pointer(rt->fib6_node), 1956 res); 1957 #endif 1958 continue; 1959 } 1960 return 0; 1961 } else if (res == -2) { 1962 if (WARN_ON(!rt->fib6_nsiblings)) 1963 continue; 1964 rt = list_last_entry(&rt->fib6_siblings, 1965 struct fib6_info, fib6_siblings); 1966 continue; 1967 } 1968 WARN_ON(res != 0); 1969 } 1970 w->leaf = rt; 1971 return 0; 1972 } 1973 1974 /* 1975 * Convenient frontend to tree walker. 1976 * 1977 * func is called on each route. 1978 * It may return -2 -> skip multipath route. 1979 * -1 -> delete this route. 1980 * 0 -> continue walking 1981 */ 1982 1983 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1984 int (*func)(struct fib6_info *, void *arg), 1985 int sernum, void *arg) 1986 { 1987 struct fib6_cleaner c; 1988 1989 c.w.root = root; 1990 c.w.func = fib6_clean_node; 1991 c.w.count = 0; 1992 c.w.skip = 0; 1993 c.func = func; 1994 c.sernum = sernum; 1995 c.arg = arg; 1996 c.net = net; 1997 1998 fib6_walk(net, &c.w); 1999 } 2000 2001 static void __fib6_clean_all(struct net *net, 2002 int (*func)(struct fib6_info *, void *), 2003 int sernum, void *arg) 2004 { 2005 struct fib6_table *table; 2006 struct hlist_head *head; 2007 unsigned int h; 2008 2009 rcu_read_lock(); 2010 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2011 head = &net->ipv6.fib_table_hash[h]; 2012 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2013 spin_lock_bh(&table->tb6_lock); 2014 fib6_clean_tree(net, &table->tb6_root, 2015 func, sernum, arg); 2016 spin_unlock_bh(&table->tb6_lock); 2017 } 2018 } 2019 rcu_read_unlock(); 2020 } 2021 2022 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2023 void *arg) 2024 { 2025 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 2026 } 2027 2028 static void fib6_flush_trees(struct net *net) 2029 { 2030 int new_sernum = fib6_new_sernum(net); 2031 2032 __fib6_clean_all(net, NULL, new_sernum, NULL); 2033 } 2034 2035 /* 2036 * Garbage collection 2037 */ 2038 2039 static int fib6_age(struct fib6_info *rt, void *arg) 2040 { 2041 struct fib6_gc_args *gc_args = arg; 2042 unsigned long now = jiffies; 2043 2044 /* 2045 * check addrconf expiration here. 2046 * Routes are expired even if they are in use. 2047 */ 2048 2049 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2050 if (time_after(now, rt->expires)) { 2051 RT6_TRACE("expiring %p\n", rt); 2052 return -1; 2053 } 2054 gc_args->more++; 2055 } 2056 2057 /* Also age clones in the exception table. 2058 * Note, that clones are aged out 2059 * only if they are not in use now. 2060 */ 2061 rt6_age_exceptions(rt, gc_args, now); 2062 2063 return 0; 2064 } 2065 2066 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2067 { 2068 struct fib6_gc_args gc_args; 2069 unsigned long now; 2070 2071 if (force) { 2072 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2073 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2074 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2075 return; 2076 } 2077 gc_args.timeout = expires ? (int)expires : 2078 net->ipv6.sysctl.ip6_rt_gc_interval; 2079 gc_args.more = 0; 2080 2081 fib6_clean_all(net, fib6_age, &gc_args); 2082 now = jiffies; 2083 net->ipv6.ip6_rt_last_gc = now; 2084 2085 if (gc_args.more) 2086 mod_timer(&net->ipv6.ip6_fib_timer, 2087 round_jiffies(now 2088 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2089 else 2090 del_timer(&net->ipv6.ip6_fib_timer); 2091 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2092 } 2093 2094 static void fib6_gc_timer_cb(struct timer_list *t) 2095 { 2096 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2097 2098 fib6_run_gc(0, arg, true); 2099 } 2100 2101 static int __net_init fib6_net_init(struct net *net) 2102 { 2103 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2104 int err; 2105 2106 err = fib6_notifier_init(net); 2107 if (err) 2108 return err; 2109 2110 spin_lock_init(&net->ipv6.fib6_gc_lock); 2111 rwlock_init(&net->ipv6.fib6_walker_lock); 2112 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2113 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2114 2115 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2116 if (!net->ipv6.rt6_stats) 2117 goto out_timer; 2118 2119 /* Avoid false sharing : Use at least a full cache line */ 2120 size = max_t(size_t, size, L1_CACHE_BYTES); 2121 2122 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2123 if (!net->ipv6.fib_table_hash) 2124 goto out_rt6_stats; 2125 2126 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2127 GFP_KERNEL); 2128 if (!net->ipv6.fib6_main_tbl) 2129 goto out_fib_table_hash; 2130 2131 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2132 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2133 net->ipv6.fib6_null_entry); 2134 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2135 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2136 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2137 2138 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2139 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2140 GFP_KERNEL); 2141 if (!net->ipv6.fib6_local_tbl) 2142 goto out_fib6_main_tbl; 2143 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2144 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2145 net->ipv6.fib6_null_entry); 2146 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2147 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2148 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2149 #endif 2150 fib6_tables_init(net); 2151 2152 return 0; 2153 2154 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2155 out_fib6_main_tbl: 2156 kfree(net->ipv6.fib6_main_tbl); 2157 #endif 2158 out_fib_table_hash: 2159 kfree(net->ipv6.fib_table_hash); 2160 out_rt6_stats: 2161 kfree(net->ipv6.rt6_stats); 2162 out_timer: 2163 fib6_notifier_exit(net); 2164 return -ENOMEM; 2165 } 2166 2167 static void fib6_net_exit(struct net *net) 2168 { 2169 unsigned int i; 2170 2171 del_timer_sync(&net->ipv6.ip6_fib_timer); 2172 2173 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2174 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2175 struct hlist_node *tmp; 2176 struct fib6_table *tb; 2177 2178 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2179 hlist_del(&tb->tb6_hlist); 2180 fib6_free_table(tb); 2181 } 2182 } 2183 2184 kfree(net->ipv6.fib_table_hash); 2185 kfree(net->ipv6.rt6_stats); 2186 fib6_notifier_exit(net); 2187 } 2188 2189 static struct pernet_operations fib6_net_ops = { 2190 .init = fib6_net_init, 2191 .exit = fib6_net_exit, 2192 }; 2193 2194 int __init fib6_init(void) 2195 { 2196 int ret = -ENOMEM; 2197 2198 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2199 sizeof(struct fib6_node), 2200 0, SLAB_HWCACHE_ALIGN, 2201 NULL); 2202 if (!fib6_node_kmem) 2203 goto out; 2204 2205 ret = register_pernet_subsys(&fib6_net_ops); 2206 if (ret) 2207 goto out_kmem_cache_create; 2208 2209 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2210 inet6_dump_fib, 0); 2211 if (ret) 2212 goto out_unregister_subsys; 2213 2214 __fib6_flush_trees = fib6_flush_trees; 2215 out: 2216 return ret; 2217 2218 out_unregister_subsys: 2219 unregister_pernet_subsys(&fib6_net_ops); 2220 out_kmem_cache_create: 2221 kmem_cache_destroy(fib6_node_kmem); 2222 goto out; 2223 } 2224 2225 void fib6_gc_cleanup(void) 2226 { 2227 unregister_pernet_subsys(&fib6_net_ops); 2228 kmem_cache_destroy(fib6_node_kmem); 2229 } 2230 2231 #ifdef CONFIG_PROC_FS 2232 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2233 { 2234 struct fib6_info *rt = v; 2235 struct ipv6_route_iter *iter = seq->private; 2236 const struct net_device *dev; 2237 2238 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2239 2240 #ifdef CONFIG_IPV6_SUBTREES 2241 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2242 #else 2243 seq_puts(seq, "00000000000000000000000000000000 00 "); 2244 #endif 2245 if (rt->fib6_flags & RTF_GATEWAY) 2246 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw); 2247 else 2248 seq_puts(seq, "00000000000000000000000000000000"); 2249 2250 dev = rt->fib6_nh.nh_dev; 2251 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2252 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0, 2253 rt->fib6_flags, dev ? dev->name : ""); 2254 iter->w.leaf = NULL; 2255 return 0; 2256 } 2257 2258 static int ipv6_route_yield(struct fib6_walker *w) 2259 { 2260 struct ipv6_route_iter *iter = w->args; 2261 2262 if (!iter->skip) 2263 return 1; 2264 2265 do { 2266 iter->w.leaf = rcu_dereference_protected( 2267 iter->w.leaf->fib6_next, 2268 lockdep_is_held(&iter->tbl->tb6_lock)); 2269 iter->skip--; 2270 if (!iter->skip && iter->w.leaf) 2271 return 1; 2272 } while (iter->w.leaf); 2273 2274 return 0; 2275 } 2276 2277 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2278 struct net *net) 2279 { 2280 memset(&iter->w, 0, sizeof(iter->w)); 2281 iter->w.func = ipv6_route_yield; 2282 iter->w.root = &iter->tbl->tb6_root; 2283 iter->w.state = FWS_INIT; 2284 iter->w.node = iter->w.root; 2285 iter->w.args = iter; 2286 iter->sernum = iter->w.root->fn_sernum; 2287 INIT_LIST_HEAD(&iter->w.lh); 2288 fib6_walker_link(net, &iter->w); 2289 } 2290 2291 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2292 struct net *net) 2293 { 2294 unsigned int h; 2295 struct hlist_node *node; 2296 2297 if (tbl) { 2298 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2299 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2300 } else { 2301 h = 0; 2302 node = NULL; 2303 } 2304 2305 while (!node && h < FIB6_TABLE_HASHSZ) { 2306 node = rcu_dereference_bh( 2307 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2308 } 2309 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2310 } 2311 2312 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2313 { 2314 if (iter->sernum != iter->w.root->fn_sernum) { 2315 iter->sernum = iter->w.root->fn_sernum; 2316 iter->w.state = FWS_INIT; 2317 iter->w.node = iter->w.root; 2318 WARN_ON(iter->w.skip); 2319 iter->w.skip = iter->w.count; 2320 } 2321 } 2322 2323 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2324 { 2325 int r; 2326 struct fib6_info *n; 2327 struct net *net = seq_file_net(seq); 2328 struct ipv6_route_iter *iter = seq->private; 2329 2330 if (!v) 2331 goto iter_table; 2332 2333 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2334 if (n) { 2335 ++*pos; 2336 return n; 2337 } 2338 2339 iter_table: 2340 ipv6_route_check_sernum(iter); 2341 spin_lock_bh(&iter->tbl->tb6_lock); 2342 r = fib6_walk_continue(&iter->w); 2343 spin_unlock_bh(&iter->tbl->tb6_lock); 2344 if (r > 0) { 2345 if (v) 2346 ++*pos; 2347 return iter->w.leaf; 2348 } else if (r < 0) { 2349 fib6_walker_unlink(net, &iter->w); 2350 return NULL; 2351 } 2352 fib6_walker_unlink(net, &iter->w); 2353 2354 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2355 if (!iter->tbl) 2356 return NULL; 2357 2358 ipv6_route_seq_setup_walk(iter, net); 2359 goto iter_table; 2360 } 2361 2362 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2363 __acquires(RCU_BH) 2364 { 2365 struct net *net = seq_file_net(seq); 2366 struct ipv6_route_iter *iter = seq->private; 2367 2368 rcu_read_lock_bh(); 2369 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2370 iter->skip = *pos; 2371 2372 if (iter->tbl) { 2373 ipv6_route_seq_setup_walk(iter, net); 2374 return ipv6_route_seq_next(seq, NULL, pos); 2375 } else { 2376 return NULL; 2377 } 2378 } 2379 2380 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2381 { 2382 struct fib6_walker *w = &iter->w; 2383 return w->node && !(w->state == FWS_U && w->node == w->root); 2384 } 2385 2386 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2387 __releases(RCU_BH) 2388 { 2389 struct net *net = seq_file_net(seq); 2390 struct ipv6_route_iter *iter = seq->private; 2391 2392 if (ipv6_route_iter_active(iter)) 2393 fib6_walker_unlink(net, &iter->w); 2394 2395 rcu_read_unlock_bh(); 2396 } 2397 2398 const struct seq_operations ipv6_route_seq_ops = { 2399 .start = ipv6_route_seq_start, 2400 .next = ipv6_route_seq_next, 2401 .stop = ipv6_route_seq_stop, 2402 .show = ipv6_route_seq_show 2403 }; 2404 #endif /* CONFIG_PROC_FS */ 2405