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 struct fib6_info *iter = NULL; 939 struct fib6_info __rcu **ins; 940 struct fib6_info __rcu **fallback_ins = NULL; 941 int replace = (info->nlh && 942 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 943 int add = (!info->nlh || 944 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 945 int found = 0; 946 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 947 u16 nlflags = NLM_F_EXCL; 948 int err; 949 950 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 951 nlflags |= NLM_F_APPEND; 952 953 ins = &fn->leaf; 954 955 for (iter = leaf; iter; 956 iter = rcu_dereference_protected(iter->fib6_next, 957 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 958 /* 959 * Search for duplicates 960 */ 961 962 if (iter->fib6_metric == rt->fib6_metric) { 963 /* 964 * Same priority level 965 */ 966 if (info->nlh && 967 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 968 return -EEXIST; 969 970 nlflags &= ~NLM_F_EXCL; 971 if (replace) { 972 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 973 found++; 974 break; 975 } 976 if (rt_can_ecmp) 977 fallback_ins = fallback_ins ?: ins; 978 goto next_iter; 979 } 980 981 if (rt6_duplicate_nexthop(iter, rt)) { 982 if (rt->fib6_nsiblings) 983 rt->fib6_nsiblings = 0; 984 if (!(iter->fib6_flags & RTF_EXPIRES)) 985 return -EEXIST; 986 if (!(rt->fib6_flags & RTF_EXPIRES)) 987 fib6_clean_expires(iter); 988 else 989 fib6_set_expires(iter, rt->expires); 990 fib6_metric_set(iter, RTAX_MTU, rt->fib6_pmtu); 991 return -EEXIST; 992 } 993 /* If we have the same destination and the same metric, 994 * but not the same gateway, then the route we try to 995 * add is sibling to this route, increment our counter 996 * of siblings, and later we will add our route to the 997 * list. 998 * Only static routes (which don't have flag 999 * RTF_EXPIRES) are used for ECMPv6. 1000 * 1001 * To avoid long list, we only had siblings if the 1002 * route have a gateway. 1003 */ 1004 if (rt_can_ecmp && 1005 rt6_qualify_for_ecmp(iter)) 1006 rt->fib6_nsiblings++; 1007 } 1008 1009 if (iter->fib6_metric > rt->fib6_metric) 1010 break; 1011 1012 next_iter: 1013 ins = &iter->fib6_next; 1014 } 1015 1016 if (fallback_ins && !found) { 1017 /* No ECMP-able route found, replace first non-ECMP one */ 1018 ins = fallback_ins; 1019 iter = rcu_dereference_protected(*ins, 1020 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1021 found++; 1022 } 1023 1024 /* Reset round-robin state, if necessary */ 1025 if (ins == &fn->leaf) 1026 fn->rr_ptr = NULL; 1027 1028 /* Link this route to others same route. */ 1029 if (rt->fib6_nsiblings) { 1030 unsigned int fib6_nsiblings; 1031 struct fib6_info *sibling, *temp_sibling; 1032 1033 /* Find the first route that have the same metric */ 1034 sibling = leaf; 1035 while (sibling) { 1036 if (sibling->fib6_metric == rt->fib6_metric && 1037 rt6_qualify_for_ecmp(sibling)) { 1038 list_add_tail(&rt->fib6_siblings, 1039 &sibling->fib6_siblings); 1040 break; 1041 } 1042 sibling = rcu_dereference_protected(sibling->fib6_next, 1043 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1044 } 1045 /* For each sibling in the list, increment the counter of 1046 * siblings. BUG() if counters does not match, list of siblings 1047 * is broken! 1048 */ 1049 fib6_nsiblings = 0; 1050 list_for_each_entry_safe(sibling, temp_sibling, 1051 &rt->fib6_siblings, fib6_siblings) { 1052 sibling->fib6_nsiblings++; 1053 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1054 fib6_nsiblings++; 1055 } 1056 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1057 rt6_multipath_rebalance(temp_sibling); 1058 } 1059 1060 /* 1061 * insert node 1062 */ 1063 if (!replace) { 1064 if (!add) 1065 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1066 1067 add: 1068 nlflags |= NLM_F_CREATE; 1069 1070 err = call_fib6_entry_notifiers(info->nl_net, 1071 FIB_EVENT_ENTRY_ADD, 1072 rt, extack); 1073 if (err) 1074 return err; 1075 1076 rcu_assign_pointer(rt->fib6_next, iter); 1077 atomic_inc(&rt->fib6_ref); 1078 rcu_assign_pointer(rt->fib6_node, fn); 1079 rcu_assign_pointer(*ins, rt); 1080 if (!info->skip_notify) 1081 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1082 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1083 1084 if (!(fn->fn_flags & RTN_RTINFO)) { 1085 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1086 fn->fn_flags |= RTN_RTINFO; 1087 } 1088 1089 } else { 1090 int nsiblings; 1091 1092 if (!found) { 1093 if (add) 1094 goto add; 1095 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1096 return -ENOENT; 1097 } 1098 1099 err = call_fib6_entry_notifiers(info->nl_net, 1100 FIB_EVENT_ENTRY_REPLACE, 1101 rt, extack); 1102 if (err) 1103 return err; 1104 1105 atomic_inc(&rt->fib6_ref); 1106 rcu_assign_pointer(rt->fib6_node, fn); 1107 rt->fib6_next = iter->fib6_next; 1108 rcu_assign_pointer(*ins, rt); 1109 if (!info->skip_notify) 1110 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1111 if (!(fn->fn_flags & RTN_RTINFO)) { 1112 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1113 fn->fn_flags |= RTN_RTINFO; 1114 } 1115 nsiblings = iter->fib6_nsiblings; 1116 iter->fib6_node = NULL; 1117 fib6_purge_rt(iter, fn, info->nl_net); 1118 if (rcu_access_pointer(fn->rr_ptr) == iter) 1119 fn->rr_ptr = NULL; 1120 fib6_info_release(iter); 1121 1122 if (nsiblings) { 1123 /* Replacing an ECMP route, remove all siblings */ 1124 ins = &rt->fib6_next; 1125 iter = rcu_dereference_protected(*ins, 1126 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1127 while (iter) { 1128 if (iter->fib6_metric > rt->fib6_metric) 1129 break; 1130 if (rt6_qualify_for_ecmp(iter)) { 1131 *ins = iter->fib6_next; 1132 iter->fib6_node = NULL; 1133 fib6_purge_rt(iter, fn, info->nl_net); 1134 if (rcu_access_pointer(fn->rr_ptr) == iter) 1135 fn->rr_ptr = NULL; 1136 fib6_info_release(iter); 1137 nsiblings--; 1138 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1139 } else { 1140 ins = &iter->fib6_next; 1141 } 1142 iter = rcu_dereference_protected(*ins, 1143 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1144 } 1145 WARN_ON(nsiblings != 0); 1146 } 1147 } 1148 1149 return 0; 1150 } 1151 1152 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1153 { 1154 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1155 (rt->fib6_flags & RTF_EXPIRES)) 1156 mod_timer(&net->ipv6.ip6_fib_timer, 1157 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1158 } 1159 1160 void fib6_force_start_gc(struct net *net) 1161 { 1162 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1163 mod_timer(&net->ipv6.ip6_fib_timer, 1164 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1165 } 1166 1167 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1168 int sernum) 1169 { 1170 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1171 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1172 1173 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1174 smp_wmb(); 1175 while (fn) { 1176 fn->fn_sernum = sernum; 1177 fn = rcu_dereference_protected(fn->parent, 1178 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1179 } 1180 } 1181 1182 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1183 { 1184 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1185 } 1186 1187 /* 1188 * Add routing information to the routing tree. 1189 * <destination addr>/<source addr> 1190 * with source addr info in sub-trees 1191 * Need to own table->tb6_lock 1192 */ 1193 1194 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1195 struct nl_info *info, struct netlink_ext_ack *extack) 1196 { 1197 struct fib6_table *table = rt->fib6_table; 1198 struct fib6_node *fn, *pn = NULL; 1199 int err = -ENOMEM; 1200 int allow_create = 1; 1201 int replace_required = 0; 1202 int sernum = fib6_new_sernum(info->nl_net); 1203 1204 if (info->nlh) { 1205 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1206 allow_create = 0; 1207 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1208 replace_required = 1; 1209 } 1210 if (!allow_create && !replace_required) 1211 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1212 1213 fn = fib6_add_1(info->nl_net, table, root, 1214 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1215 offsetof(struct fib6_info, fib6_dst), allow_create, 1216 replace_required, extack); 1217 if (IS_ERR(fn)) { 1218 err = PTR_ERR(fn); 1219 fn = NULL; 1220 goto out; 1221 } 1222 1223 pn = fn; 1224 1225 #ifdef CONFIG_IPV6_SUBTREES 1226 if (rt->fib6_src.plen) { 1227 struct fib6_node *sn; 1228 1229 if (!rcu_access_pointer(fn->subtree)) { 1230 struct fib6_node *sfn; 1231 1232 /* 1233 * Create subtree. 1234 * 1235 * fn[main tree] 1236 * | 1237 * sfn[subtree root] 1238 * \ 1239 * sn[new leaf node] 1240 */ 1241 1242 /* Create subtree root node */ 1243 sfn = node_alloc(info->nl_net); 1244 if (!sfn) 1245 goto failure; 1246 1247 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref); 1248 rcu_assign_pointer(sfn->leaf, 1249 info->nl_net->ipv6.fib6_null_entry); 1250 sfn->fn_flags = RTN_ROOT; 1251 1252 /* Now add the first leaf node to new subtree */ 1253 1254 sn = fib6_add_1(info->nl_net, table, sfn, 1255 &rt->fib6_src.addr, rt->fib6_src.plen, 1256 offsetof(struct fib6_info, fib6_src), 1257 allow_create, replace_required, extack); 1258 1259 if (IS_ERR(sn)) { 1260 /* If it is failed, discard just allocated 1261 root, and then (in failure) stale node 1262 in main tree. 1263 */ 1264 node_free_immediate(info->nl_net, sfn); 1265 err = PTR_ERR(sn); 1266 goto failure; 1267 } 1268 1269 /* Now link new subtree to main tree */ 1270 rcu_assign_pointer(sfn->parent, fn); 1271 rcu_assign_pointer(fn->subtree, sfn); 1272 } else { 1273 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1274 &rt->fib6_src.addr, rt->fib6_src.plen, 1275 offsetof(struct fib6_info, fib6_src), 1276 allow_create, replace_required, extack); 1277 1278 if (IS_ERR(sn)) { 1279 err = PTR_ERR(sn); 1280 goto failure; 1281 } 1282 } 1283 1284 if (!rcu_access_pointer(fn->leaf)) { 1285 if (fn->fn_flags & RTN_TL_ROOT) { 1286 /* put back null_entry for root node */ 1287 rcu_assign_pointer(fn->leaf, 1288 info->nl_net->ipv6.fib6_null_entry); 1289 } else { 1290 atomic_inc(&rt->fib6_ref); 1291 rcu_assign_pointer(fn->leaf, rt); 1292 } 1293 } 1294 fn = sn; 1295 } 1296 #endif 1297 1298 err = fib6_add_rt2node(fn, rt, info, extack); 1299 if (!err) { 1300 __fib6_update_sernum_upto_root(rt, sernum); 1301 fib6_start_gc(info->nl_net, rt); 1302 } 1303 1304 out: 1305 if (err) { 1306 #ifdef CONFIG_IPV6_SUBTREES 1307 /* 1308 * If fib6_add_1 has cleared the old leaf pointer in the 1309 * super-tree leaf node we have to find a new one for it. 1310 */ 1311 if (pn != fn) { 1312 struct fib6_info *pn_leaf = 1313 rcu_dereference_protected(pn->leaf, 1314 lockdep_is_held(&table->tb6_lock)); 1315 if (pn_leaf == rt) { 1316 pn_leaf = NULL; 1317 RCU_INIT_POINTER(pn->leaf, NULL); 1318 fib6_info_release(rt); 1319 } 1320 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1321 pn_leaf = fib6_find_prefix(info->nl_net, table, 1322 pn); 1323 #if RT6_DEBUG >= 2 1324 if (!pn_leaf) { 1325 WARN_ON(!pn_leaf); 1326 pn_leaf = 1327 info->nl_net->ipv6.fib6_null_entry; 1328 } 1329 #endif 1330 fib6_info_hold(pn_leaf); 1331 rcu_assign_pointer(pn->leaf, pn_leaf); 1332 } 1333 } 1334 #endif 1335 goto failure; 1336 } 1337 return err; 1338 1339 failure: 1340 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1341 * 1. fn is an intermediate node and we failed to add the new 1342 * route to it in both subtree creation failure and fib6_add_rt2node() 1343 * failure case. 1344 * 2. fn is the root node in the table and we fail to add the first 1345 * default route to it. 1346 */ 1347 if (fn && 1348 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1349 (fn->fn_flags & RTN_TL_ROOT && 1350 !rcu_access_pointer(fn->leaf)))) 1351 fib6_repair_tree(info->nl_net, table, fn); 1352 return err; 1353 } 1354 1355 /* 1356 * Routing tree lookup 1357 * 1358 */ 1359 1360 struct lookup_args { 1361 int offset; /* key offset on fib6_info */ 1362 const struct in6_addr *addr; /* search key */ 1363 }; 1364 1365 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1366 struct lookup_args *args) 1367 { 1368 struct fib6_node *fn; 1369 __be32 dir; 1370 1371 if (unlikely(args->offset == 0)) 1372 return NULL; 1373 1374 /* 1375 * Descend on a tree 1376 */ 1377 1378 fn = root; 1379 1380 for (;;) { 1381 struct fib6_node *next; 1382 1383 dir = addr_bit_set(args->addr, fn->fn_bit); 1384 1385 next = dir ? rcu_dereference(fn->right) : 1386 rcu_dereference(fn->left); 1387 1388 if (next) { 1389 fn = next; 1390 continue; 1391 } 1392 break; 1393 } 1394 1395 while (fn) { 1396 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1397 1398 if (subtree || fn->fn_flags & RTN_RTINFO) { 1399 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1400 struct rt6key *key; 1401 1402 if (!leaf) 1403 goto backtrack; 1404 1405 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1406 1407 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1408 #ifdef CONFIG_IPV6_SUBTREES 1409 if (subtree) { 1410 struct fib6_node *sfn; 1411 sfn = fib6_node_lookup_1(subtree, 1412 args + 1); 1413 if (!sfn) 1414 goto backtrack; 1415 fn = sfn; 1416 } 1417 #endif 1418 if (fn->fn_flags & RTN_RTINFO) 1419 return fn; 1420 } 1421 } 1422 backtrack: 1423 if (fn->fn_flags & RTN_ROOT) 1424 break; 1425 1426 fn = rcu_dereference(fn->parent); 1427 } 1428 1429 return NULL; 1430 } 1431 1432 /* called with rcu_read_lock() held 1433 */ 1434 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1435 const struct in6_addr *daddr, 1436 const struct in6_addr *saddr) 1437 { 1438 struct fib6_node *fn; 1439 struct lookup_args args[] = { 1440 { 1441 .offset = offsetof(struct fib6_info, fib6_dst), 1442 .addr = daddr, 1443 }, 1444 #ifdef CONFIG_IPV6_SUBTREES 1445 { 1446 .offset = offsetof(struct fib6_info, fib6_src), 1447 .addr = saddr, 1448 }, 1449 #endif 1450 { 1451 .offset = 0, /* sentinel */ 1452 } 1453 }; 1454 1455 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1456 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1457 fn = root; 1458 1459 return fn; 1460 } 1461 1462 /* 1463 * Get node with specified destination prefix (and source prefix, 1464 * if subtrees are used) 1465 * exact_match == true means we try to find fn with exact match of 1466 * the passed in prefix addr 1467 * exact_match == false means we try to find fn with longest prefix 1468 * match of the passed in prefix addr. This is useful for finding fn 1469 * for cached route as it will be stored in the exception table under 1470 * the node with longest prefix length. 1471 */ 1472 1473 1474 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1475 const struct in6_addr *addr, 1476 int plen, int offset, 1477 bool exact_match) 1478 { 1479 struct fib6_node *fn, *prev = NULL; 1480 1481 for (fn = root; fn ; ) { 1482 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1483 struct rt6key *key; 1484 1485 /* This node is being deleted */ 1486 if (!leaf) { 1487 if (plen <= fn->fn_bit) 1488 goto out; 1489 else 1490 goto next; 1491 } 1492 1493 key = (struct rt6key *)((u8 *)leaf + offset); 1494 1495 /* 1496 * Prefix match 1497 */ 1498 if (plen < fn->fn_bit || 1499 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1500 goto out; 1501 1502 if (plen == fn->fn_bit) 1503 return fn; 1504 1505 prev = fn; 1506 1507 next: 1508 /* 1509 * We have more bits to go 1510 */ 1511 if (addr_bit_set(addr, fn->fn_bit)) 1512 fn = rcu_dereference(fn->right); 1513 else 1514 fn = rcu_dereference(fn->left); 1515 } 1516 out: 1517 if (exact_match) 1518 return NULL; 1519 else 1520 return prev; 1521 } 1522 1523 struct fib6_node *fib6_locate(struct fib6_node *root, 1524 const struct in6_addr *daddr, int dst_len, 1525 const struct in6_addr *saddr, int src_len, 1526 bool exact_match) 1527 { 1528 struct fib6_node *fn; 1529 1530 fn = fib6_locate_1(root, daddr, dst_len, 1531 offsetof(struct fib6_info, fib6_dst), 1532 exact_match); 1533 1534 #ifdef CONFIG_IPV6_SUBTREES 1535 if (src_len) { 1536 WARN_ON(saddr == NULL); 1537 if (fn) { 1538 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1539 1540 if (subtree) { 1541 fn = fib6_locate_1(subtree, saddr, src_len, 1542 offsetof(struct fib6_info, fib6_src), 1543 exact_match); 1544 } 1545 } 1546 } 1547 #endif 1548 1549 if (fn && fn->fn_flags & RTN_RTINFO) 1550 return fn; 1551 1552 return NULL; 1553 } 1554 1555 1556 /* 1557 * Deletion 1558 * 1559 */ 1560 1561 static struct fib6_info *fib6_find_prefix(struct net *net, 1562 struct fib6_table *table, 1563 struct fib6_node *fn) 1564 { 1565 struct fib6_node *child_left, *child_right; 1566 1567 if (fn->fn_flags & RTN_ROOT) 1568 return net->ipv6.fib6_null_entry; 1569 1570 while (fn) { 1571 child_left = rcu_dereference_protected(fn->left, 1572 lockdep_is_held(&table->tb6_lock)); 1573 child_right = rcu_dereference_protected(fn->right, 1574 lockdep_is_held(&table->tb6_lock)); 1575 if (child_left) 1576 return rcu_dereference_protected(child_left->leaf, 1577 lockdep_is_held(&table->tb6_lock)); 1578 if (child_right) 1579 return rcu_dereference_protected(child_right->leaf, 1580 lockdep_is_held(&table->tb6_lock)); 1581 1582 fn = FIB6_SUBTREE(fn); 1583 } 1584 return NULL; 1585 } 1586 1587 /* 1588 * Called to trim the tree of intermediate nodes when possible. "fn" 1589 * is the node we want to try and remove. 1590 * Need to own table->tb6_lock 1591 */ 1592 1593 static struct fib6_node *fib6_repair_tree(struct net *net, 1594 struct fib6_table *table, 1595 struct fib6_node *fn) 1596 { 1597 int children; 1598 int nstate; 1599 struct fib6_node *child; 1600 struct fib6_walker *w; 1601 int iter = 0; 1602 1603 /* Set fn->leaf to null_entry for root node. */ 1604 if (fn->fn_flags & RTN_TL_ROOT) { 1605 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1606 return fn; 1607 } 1608 1609 for (;;) { 1610 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1611 lockdep_is_held(&table->tb6_lock)); 1612 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1613 lockdep_is_held(&table->tb6_lock)); 1614 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1615 lockdep_is_held(&table->tb6_lock)); 1616 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1617 lockdep_is_held(&table->tb6_lock)); 1618 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1619 lockdep_is_held(&table->tb6_lock)); 1620 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1621 lockdep_is_held(&table->tb6_lock)); 1622 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1623 lockdep_is_held(&table->tb6_lock)); 1624 struct fib6_info *new_fn_leaf; 1625 1626 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1627 iter++; 1628 1629 WARN_ON(fn->fn_flags & RTN_RTINFO); 1630 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1631 WARN_ON(fn_leaf); 1632 1633 children = 0; 1634 child = NULL; 1635 if (fn_r) 1636 child = fn_r, children |= 1; 1637 if (fn_l) 1638 child = fn_l, children |= 2; 1639 1640 if (children == 3 || FIB6_SUBTREE(fn) 1641 #ifdef CONFIG_IPV6_SUBTREES 1642 /* Subtree root (i.e. fn) may have one child */ 1643 || (children && fn->fn_flags & RTN_ROOT) 1644 #endif 1645 ) { 1646 new_fn_leaf = fib6_find_prefix(net, table, fn); 1647 #if RT6_DEBUG >= 2 1648 if (!new_fn_leaf) { 1649 WARN_ON(!new_fn_leaf); 1650 new_fn_leaf = net->ipv6.fib6_null_entry; 1651 } 1652 #endif 1653 fib6_info_hold(new_fn_leaf); 1654 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1655 return pn; 1656 } 1657 1658 #ifdef CONFIG_IPV6_SUBTREES 1659 if (FIB6_SUBTREE(pn) == fn) { 1660 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1661 RCU_INIT_POINTER(pn->subtree, NULL); 1662 nstate = FWS_L; 1663 } else { 1664 WARN_ON(fn->fn_flags & RTN_ROOT); 1665 #endif 1666 if (pn_r == fn) 1667 rcu_assign_pointer(pn->right, child); 1668 else if (pn_l == fn) 1669 rcu_assign_pointer(pn->left, child); 1670 #if RT6_DEBUG >= 2 1671 else 1672 WARN_ON(1); 1673 #endif 1674 if (child) 1675 rcu_assign_pointer(child->parent, pn); 1676 nstate = FWS_R; 1677 #ifdef CONFIG_IPV6_SUBTREES 1678 } 1679 #endif 1680 1681 read_lock(&net->ipv6.fib6_walker_lock); 1682 FOR_WALKERS(net, w) { 1683 if (!child) { 1684 if (w->node == fn) { 1685 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1686 w->node = pn; 1687 w->state = nstate; 1688 } 1689 } else { 1690 if (w->node == fn) { 1691 w->node = child; 1692 if (children&2) { 1693 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1694 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1695 } else { 1696 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1697 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1698 } 1699 } 1700 } 1701 } 1702 read_unlock(&net->ipv6.fib6_walker_lock); 1703 1704 node_free(net, fn); 1705 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1706 return pn; 1707 1708 RCU_INIT_POINTER(pn->leaf, NULL); 1709 fib6_info_release(pn_leaf); 1710 fn = pn; 1711 } 1712 } 1713 1714 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1715 struct fib6_info __rcu **rtp, struct nl_info *info) 1716 { 1717 struct fib6_walker *w; 1718 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1719 lockdep_is_held(&table->tb6_lock)); 1720 struct net *net = info->nl_net; 1721 1722 RT6_TRACE("fib6_del_route\n"); 1723 1724 /* Unlink it */ 1725 *rtp = rt->fib6_next; 1726 rt->fib6_node = NULL; 1727 net->ipv6.rt6_stats->fib_rt_entries--; 1728 net->ipv6.rt6_stats->fib_discarded_routes++; 1729 1730 /* Flush all cached dst in exception table */ 1731 rt6_flush_exceptions(rt); 1732 1733 /* Reset round-robin state, if necessary */ 1734 if (rcu_access_pointer(fn->rr_ptr) == rt) 1735 fn->rr_ptr = NULL; 1736 1737 /* Remove this entry from other siblings */ 1738 if (rt->fib6_nsiblings) { 1739 struct fib6_info *sibling, *next_sibling; 1740 1741 list_for_each_entry_safe(sibling, next_sibling, 1742 &rt->fib6_siblings, fib6_siblings) 1743 sibling->fib6_nsiblings--; 1744 rt->fib6_nsiblings = 0; 1745 list_del_init(&rt->fib6_siblings); 1746 rt6_multipath_rebalance(next_sibling); 1747 } 1748 1749 /* Adjust walkers */ 1750 read_lock(&net->ipv6.fib6_walker_lock); 1751 FOR_WALKERS(net, w) { 1752 if (w->state == FWS_C && w->leaf == rt) { 1753 RT6_TRACE("walker %p adjusted by delroute\n", w); 1754 w->leaf = rcu_dereference_protected(rt->fib6_next, 1755 lockdep_is_held(&table->tb6_lock)); 1756 if (!w->leaf) 1757 w->state = FWS_U; 1758 } 1759 } 1760 read_unlock(&net->ipv6.fib6_walker_lock); 1761 1762 /* If it was last route, call fib6_repair_tree() to: 1763 * 1. For root node, put back null_entry as how the table was created. 1764 * 2. For other nodes, expunge its radix tree node. 1765 */ 1766 if (!rcu_access_pointer(fn->leaf)) { 1767 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1768 fn->fn_flags &= ~RTN_RTINFO; 1769 net->ipv6.rt6_stats->fib_route_nodes--; 1770 } 1771 fn = fib6_repair_tree(net, table, fn); 1772 } 1773 1774 fib6_purge_rt(rt, fn, net); 1775 1776 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1777 if (!info->skip_notify) 1778 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1779 fib6_info_release(rt); 1780 } 1781 1782 /* Need to own table->tb6_lock */ 1783 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1784 { 1785 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1786 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1787 struct fib6_table *table = rt->fib6_table; 1788 struct net *net = info->nl_net; 1789 struct fib6_info __rcu **rtp; 1790 struct fib6_info __rcu **rtp_next; 1791 1792 if (!fn || rt == net->ipv6.fib6_null_entry) 1793 return -ENOENT; 1794 1795 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1796 1797 /* 1798 * Walk the leaf entries looking for ourself 1799 */ 1800 1801 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1802 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1803 lockdep_is_held(&table->tb6_lock)); 1804 if (rt == cur) { 1805 fib6_del_route(table, fn, rtp, info); 1806 return 0; 1807 } 1808 rtp_next = &cur->fib6_next; 1809 } 1810 return -ENOENT; 1811 } 1812 1813 /* 1814 * Tree traversal function. 1815 * 1816 * Certainly, it is not interrupt safe. 1817 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1818 * It means, that we can modify tree during walking 1819 * and use this function for garbage collection, clone pruning, 1820 * cleaning tree when a device goes down etc. etc. 1821 * 1822 * It guarantees that every node will be traversed, 1823 * and that it will be traversed only once. 1824 * 1825 * Callback function w->func may return: 1826 * 0 -> continue walking. 1827 * positive value -> walking is suspended (used by tree dumps, 1828 * and probably by gc, if it will be split to several slices) 1829 * negative value -> terminate walking. 1830 * 1831 * The function itself returns: 1832 * 0 -> walk is complete. 1833 * >0 -> walk is incomplete (i.e. suspended) 1834 * <0 -> walk is terminated by an error. 1835 * 1836 * This function is called with tb6_lock held. 1837 */ 1838 1839 static int fib6_walk_continue(struct fib6_walker *w) 1840 { 1841 struct fib6_node *fn, *pn, *left, *right; 1842 1843 /* w->root should always be table->tb6_root */ 1844 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1845 1846 for (;;) { 1847 fn = w->node; 1848 if (!fn) 1849 return 0; 1850 1851 switch (w->state) { 1852 #ifdef CONFIG_IPV6_SUBTREES 1853 case FWS_S: 1854 if (FIB6_SUBTREE(fn)) { 1855 w->node = FIB6_SUBTREE(fn); 1856 continue; 1857 } 1858 w->state = FWS_L; 1859 #endif 1860 /* fall through */ 1861 case FWS_L: 1862 left = rcu_dereference_protected(fn->left, 1); 1863 if (left) { 1864 w->node = left; 1865 w->state = FWS_INIT; 1866 continue; 1867 } 1868 w->state = FWS_R; 1869 /* fall through */ 1870 case FWS_R: 1871 right = rcu_dereference_protected(fn->right, 1); 1872 if (right) { 1873 w->node = right; 1874 w->state = FWS_INIT; 1875 continue; 1876 } 1877 w->state = FWS_C; 1878 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1879 /* fall through */ 1880 case FWS_C: 1881 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1882 int err; 1883 1884 if (w->skip) { 1885 w->skip--; 1886 goto skip; 1887 } 1888 1889 err = w->func(w); 1890 if (err) 1891 return err; 1892 1893 w->count++; 1894 continue; 1895 } 1896 skip: 1897 w->state = FWS_U; 1898 /* fall through */ 1899 case FWS_U: 1900 if (fn == w->root) 1901 return 0; 1902 pn = rcu_dereference_protected(fn->parent, 1); 1903 left = rcu_dereference_protected(pn->left, 1); 1904 right = rcu_dereference_protected(pn->right, 1); 1905 w->node = pn; 1906 #ifdef CONFIG_IPV6_SUBTREES 1907 if (FIB6_SUBTREE(pn) == fn) { 1908 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1909 w->state = FWS_L; 1910 continue; 1911 } 1912 #endif 1913 if (left == fn) { 1914 w->state = FWS_R; 1915 continue; 1916 } 1917 if (right == fn) { 1918 w->state = FWS_C; 1919 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1920 continue; 1921 } 1922 #if RT6_DEBUG >= 2 1923 WARN_ON(1); 1924 #endif 1925 } 1926 } 1927 } 1928 1929 static int fib6_walk(struct net *net, struct fib6_walker *w) 1930 { 1931 int res; 1932 1933 w->state = FWS_INIT; 1934 w->node = w->root; 1935 1936 fib6_walker_link(net, w); 1937 res = fib6_walk_continue(w); 1938 if (res <= 0) 1939 fib6_walker_unlink(net, w); 1940 return res; 1941 } 1942 1943 static int fib6_clean_node(struct fib6_walker *w) 1944 { 1945 int res; 1946 struct fib6_info *rt; 1947 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1948 struct nl_info info = { 1949 .nl_net = c->net, 1950 }; 1951 1952 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1953 w->node->fn_sernum != c->sernum) 1954 w->node->fn_sernum = c->sernum; 1955 1956 if (!c->func) { 1957 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1958 w->leaf = NULL; 1959 return 0; 1960 } 1961 1962 for_each_fib6_walker_rt(w) { 1963 res = c->func(rt, c->arg); 1964 if (res == -1) { 1965 w->leaf = rt; 1966 res = fib6_del(rt, &info); 1967 if (res) { 1968 #if RT6_DEBUG >= 2 1969 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1970 __func__, rt, 1971 rcu_access_pointer(rt->fib6_node), 1972 res); 1973 #endif 1974 continue; 1975 } 1976 return 0; 1977 } else if (res == -2) { 1978 if (WARN_ON(!rt->fib6_nsiblings)) 1979 continue; 1980 rt = list_last_entry(&rt->fib6_siblings, 1981 struct fib6_info, fib6_siblings); 1982 continue; 1983 } 1984 WARN_ON(res != 0); 1985 } 1986 w->leaf = rt; 1987 return 0; 1988 } 1989 1990 /* 1991 * Convenient frontend to tree walker. 1992 * 1993 * func is called on each route. 1994 * It may return -2 -> skip multipath route. 1995 * -1 -> delete this route. 1996 * 0 -> continue walking 1997 */ 1998 1999 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2000 int (*func)(struct fib6_info *, void *arg), 2001 int sernum, void *arg) 2002 { 2003 struct fib6_cleaner c; 2004 2005 c.w.root = root; 2006 c.w.func = fib6_clean_node; 2007 c.w.count = 0; 2008 c.w.skip = 0; 2009 c.func = func; 2010 c.sernum = sernum; 2011 c.arg = arg; 2012 c.net = net; 2013 2014 fib6_walk(net, &c.w); 2015 } 2016 2017 static void __fib6_clean_all(struct net *net, 2018 int (*func)(struct fib6_info *, void *), 2019 int sernum, void *arg) 2020 { 2021 struct fib6_table *table; 2022 struct hlist_head *head; 2023 unsigned int h; 2024 2025 rcu_read_lock(); 2026 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2027 head = &net->ipv6.fib_table_hash[h]; 2028 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2029 spin_lock_bh(&table->tb6_lock); 2030 fib6_clean_tree(net, &table->tb6_root, 2031 func, sernum, arg); 2032 spin_unlock_bh(&table->tb6_lock); 2033 } 2034 } 2035 rcu_read_unlock(); 2036 } 2037 2038 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2039 void *arg) 2040 { 2041 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 2042 } 2043 2044 static void fib6_flush_trees(struct net *net) 2045 { 2046 int new_sernum = fib6_new_sernum(net); 2047 2048 __fib6_clean_all(net, NULL, new_sernum, NULL); 2049 } 2050 2051 /* 2052 * Garbage collection 2053 */ 2054 2055 static int fib6_age(struct fib6_info *rt, void *arg) 2056 { 2057 struct fib6_gc_args *gc_args = arg; 2058 unsigned long now = jiffies; 2059 2060 /* 2061 * check addrconf expiration here. 2062 * Routes are expired even if they are in use. 2063 */ 2064 2065 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2066 if (time_after(now, rt->expires)) { 2067 RT6_TRACE("expiring %p\n", rt); 2068 return -1; 2069 } 2070 gc_args->more++; 2071 } 2072 2073 /* Also age clones in the exception table. 2074 * Note, that clones are aged out 2075 * only if they are not in use now. 2076 */ 2077 rt6_age_exceptions(rt, gc_args, now); 2078 2079 return 0; 2080 } 2081 2082 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2083 { 2084 struct fib6_gc_args gc_args; 2085 unsigned long now; 2086 2087 if (force) { 2088 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2089 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2090 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2091 return; 2092 } 2093 gc_args.timeout = expires ? (int)expires : 2094 net->ipv6.sysctl.ip6_rt_gc_interval; 2095 gc_args.more = 0; 2096 2097 fib6_clean_all(net, fib6_age, &gc_args); 2098 now = jiffies; 2099 net->ipv6.ip6_rt_last_gc = now; 2100 2101 if (gc_args.more) 2102 mod_timer(&net->ipv6.ip6_fib_timer, 2103 round_jiffies(now 2104 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2105 else 2106 del_timer(&net->ipv6.ip6_fib_timer); 2107 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2108 } 2109 2110 static void fib6_gc_timer_cb(struct timer_list *t) 2111 { 2112 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2113 2114 fib6_run_gc(0, arg, true); 2115 } 2116 2117 static int __net_init fib6_net_init(struct net *net) 2118 { 2119 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2120 int err; 2121 2122 err = fib6_notifier_init(net); 2123 if (err) 2124 return err; 2125 2126 spin_lock_init(&net->ipv6.fib6_gc_lock); 2127 rwlock_init(&net->ipv6.fib6_walker_lock); 2128 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2129 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2130 2131 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2132 if (!net->ipv6.rt6_stats) 2133 goto out_timer; 2134 2135 /* Avoid false sharing : Use at least a full cache line */ 2136 size = max_t(size_t, size, L1_CACHE_BYTES); 2137 2138 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2139 if (!net->ipv6.fib_table_hash) 2140 goto out_rt6_stats; 2141 2142 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2143 GFP_KERNEL); 2144 if (!net->ipv6.fib6_main_tbl) 2145 goto out_fib_table_hash; 2146 2147 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2148 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2149 net->ipv6.fib6_null_entry); 2150 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2151 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2152 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2153 2154 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2155 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2156 GFP_KERNEL); 2157 if (!net->ipv6.fib6_local_tbl) 2158 goto out_fib6_main_tbl; 2159 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2160 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2161 net->ipv6.fib6_null_entry); 2162 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2163 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2164 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2165 #endif 2166 fib6_tables_init(net); 2167 2168 return 0; 2169 2170 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2171 out_fib6_main_tbl: 2172 kfree(net->ipv6.fib6_main_tbl); 2173 #endif 2174 out_fib_table_hash: 2175 kfree(net->ipv6.fib_table_hash); 2176 out_rt6_stats: 2177 kfree(net->ipv6.rt6_stats); 2178 out_timer: 2179 fib6_notifier_exit(net); 2180 return -ENOMEM; 2181 } 2182 2183 static void fib6_net_exit(struct net *net) 2184 { 2185 unsigned int i; 2186 2187 del_timer_sync(&net->ipv6.ip6_fib_timer); 2188 2189 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2190 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2191 struct hlist_node *tmp; 2192 struct fib6_table *tb; 2193 2194 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2195 hlist_del(&tb->tb6_hlist); 2196 fib6_free_table(tb); 2197 } 2198 } 2199 2200 kfree(net->ipv6.fib_table_hash); 2201 kfree(net->ipv6.rt6_stats); 2202 fib6_notifier_exit(net); 2203 } 2204 2205 static struct pernet_operations fib6_net_ops = { 2206 .init = fib6_net_init, 2207 .exit = fib6_net_exit, 2208 }; 2209 2210 int __init fib6_init(void) 2211 { 2212 int ret = -ENOMEM; 2213 2214 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2215 sizeof(struct fib6_node), 2216 0, SLAB_HWCACHE_ALIGN, 2217 NULL); 2218 if (!fib6_node_kmem) 2219 goto out; 2220 2221 ret = register_pernet_subsys(&fib6_net_ops); 2222 if (ret) 2223 goto out_kmem_cache_create; 2224 2225 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2226 inet6_dump_fib, 0); 2227 if (ret) 2228 goto out_unregister_subsys; 2229 2230 __fib6_flush_trees = fib6_flush_trees; 2231 out: 2232 return ret; 2233 2234 out_unregister_subsys: 2235 unregister_pernet_subsys(&fib6_net_ops); 2236 out_kmem_cache_create: 2237 kmem_cache_destroy(fib6_node_kmem); 2238 goto out; 2239 } 2240 2241 void fib6_gc_cleanup(void) 2242 { 2243 unregister_pernet_subsys(&fib6_net_ops); 2244 kmem_cache_destroy(fib6_node_kmem); 2245 } 2246 2247 #ifdef CONFIG_PROC_FS 2248 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2249 { 2250 struct fib6_info *rt = v; 2251 struct ipv6_route_iter *iter = seq->private; 2252 const struct net_device *dev; 2253 2254 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2255 2256 #ifdef CONFIG_IPV6_SUBTREES 2257 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2258 #else 2259 seq_puts(seq, "00000000000000000000000000000000 00 "); 2260 #endif 2261 if (rt->fib6_flags & RTF_GATEWAY) 2262 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw); 2263 else 2264 seq_puts(seq, "00000000000000000000000000000000"); 2265 2266 dev = rt->fib6_nh.nh_dev; 2267 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2268 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0, 2269 rt->fib6_flags, dev ? dev->name : ""); 2270 iter->w.leaf = NULL; 2271 return 0; 2272 } 2273 2274 static int ipv6_route_yield(struct fib6_walker *w) 2275 { 2276 struct ipv6_route_iter *iter = w->args; 2277 2278 if (!iter->skip) 2279 return 1; 2280 2281 do { 2282 iter->w.leaf = rcu_dereference_protected( 2283 iter->w.leaf->fib6_next, 2284 lockdep_is_held(&iter->tbl->tb6_lock)); 2285 iter->skip--; 2286 if (!iter->skip && iter->w.leaf) 2287 return 1; 2288 } while (iter->w.leaf); 2289 2290 return 0; 2291 } 2292 2293 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2294 struct net *net) 2295 { 2296 memset(&iter->w, 0, sizeof(iter->w)); 2297 iter->w.func = ipv6_route_yield; 2298 iter->w.root = &iter->tbl->tb6_root; 2299 iter->w.state = FWS_INIT; 2300 iter->w.node = iter->w.root; 2301 iter->w.args = iter; 2302 iter->sernum = iter->w.root->fn_sernum; 2303 INIT_LIST_HEAD(&iter->w.lh); 2304 fib6_walker_link(net, &iter->w); 2305 } 2306 2307 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2308 struct net *net) 2309 { 2310 unsigned int h; 2311 struct hlist_node *node; 2312 2313 if (tbl) { 2314 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2315 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2316 } else { 2317 h = 0; 2318 node = NULL; 2319 } 2320 2321 while (!node && h < FIB6_TABLE_HASHSZ) { 2322 node = rcu_dereference_bh( 2323 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2324 } 2325 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2326 } 2327 2328 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2329 { 2330 if (iter->sernum != iter->w.root->fn_sernum) { 2331 iter->sernum = iter->w.root->fn_sernum; 2332 iter->w.state = FWS_INIT; 2333 iter->w.node = iter->w.root; 2334 WARN_ON(iter->w.skip); 2335 iter->w.skip = iter->w.count; 2336 } 2337 } 2338 2339 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2340 { 2341 int r; 2342 struct fib6_info *n; 2343 struct net *net = seq_file_net(seq); 2344 struct ipv6_route_iter *iter = seq->private; 2345 2346 if (!v) 2347 goto iter_table; 2348 2349 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2350 if (n) { 2351 ++*pos; 2352 return n; 2353 } 2354 2355 iter_table: 2356 ipv6_route_check_sernum(iter); 2357 spin_lock_bh(&iter->tbl->tb6_lock); 2358 r = fib6_walk_continue(&iter->w); 2359 spin_unlock_bh(&iter->tbl->tb6_lock); 2360 if (r > 0) { 2361 if (v) 2362 ++*pos; 2363 return iter->w.leaf; 2364 } else if (r < 0) { 2365 fib6_walker_unlink(net, &iter->w); 2366 return NULL; 2367 } 2368 fib6_walker_unlink(net, &iter->w); 2369 2370 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2371 if (!iter->tbl) 2372 return NULL; 2373 2374 ipv6_route_seq_setup_walk(iter, net); 2375 goto iter_table; 2376 } 2377 2378 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2379 __acquires(RCU_BH) 2380 { 2381 struct net *net = seq_file_net(seq); 2382 struct ipv6_route_iter *iter = seq->private; 2383 2384 rcu_read_lock_bh(); 2385 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2386 iter->skip = *pos; 2387 2388 if (iter->tbl) { 2389 ipv6_route_seq_setup_walk(iter, net); 2390 return ipv6_route_seq_next(seq, NULL, pos); 2391 } else { 2392 return NULL; 2393 } 2394 } 2395 2396 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2397 { 2398 struct fib6_walker *w = &iter->w; 2399 return w->node && !(w->state == FWS_U && w->node == w->root); 2400 } 2401 2402 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2403 __releases(RCU_BH) 2404 { 2405 struct net *net = seq_file_net(seq); 2406 struct ipv6_route_iter *iter = seq->private; 2407 2408 if (ipv6_route_iter_active(iter)) 2409 fib6_walker_unlink(net, &iter->w); 2410 2411 rcu_read_unlock_bh(); 2412 } 2413 2414 const struct seq_operations ipv6_route_seq_ops = { 2415 .start = ipv6_route_seq_start, 2416 .next = ipv6_route_seq_next, 2417 .stop = ipv6_route_seq_stop, 2418 .show = ipv6_route_seq_show 2419 }; 2420 #endif /* CONFIG_PROC_FS */ 2421