1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux INET6 implementation 4 * Forwarding Information Database 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * 9 * Changes: 10 * Yuji SEKIYA @USAGI: Support default route on router node; 11 * remove ip6_null_entry from the top of 12 * routing table. 13 * Ville Nuorvala: Fixed routing subtrees. 14 */ 15 16 #define pr_fmt(fmt) "IPv6: " fmt 17 18 #include <linux/errno.h> 19 #include <linux/types.h> 20 #include <linux/net.h> 21 #include <linux/route.h> 22 #include <linux/netdevice.h> 23 #include <linux/in6.h> 24 #include <linux/init.h> 25 #include <linux/list.h> 26 #include <linux/slab.h> 27 28 #include <net/ip.h> 29 #include <net/ipv6.h> 30 #include <net/ndisc.h> 31 #include <net/addrconf.h> 32 #include <net/lwtunnel.h> 33 #include <net/fib_notifier.h> 34 35 #include <net/ip6_fib.h> 36 #include <net/ip6_route.h> 37 38 static struct kmem_cache *fib6_node_kmem __read_mostly; 39 40 struct fib6_cleaner { 41 struct fib6_walker w; 42 struct net *net; 43 int (*func)(struct fib6_info *, void *arg); 44 int sernum; 45 void *arg; 46 bool skip_notify; 47 }; 48 49 #ifdef CONFIG_IPV6_SUBTREES 50 #define FWS_INIT FWS_S 51 #else 52 #define FWS_INIT FWS_L 53 #endif 54 55 static struct fib6_info *fib6_find_prefix(struct net *net, 56 struct fib6_table *table, 57 struct fib6_node *fn); 58 static struct fib6_node *fib6_repair_tree(struct net *net, 59 struct fib6_table *table, 60 struct fib6_node *fn); 61 static int fib6_walk(struct net *net, struct fib6_walker *w); 62 static int fib6_walk_continue(struct fib6_walker *w); 63 64 /* 65 * A routing update causes an increase of the serial number on the 66 * affected subtree. This allows for cached routes to be asynchronously 67 * tested when modifications are made to the destination cache as a 68 * result of redirects, path MTU changes, etc. 69 */ 70 71 static void fib6_gc_timer_cb(struct timer_list *t); 72 73 #define FOR_WALKERS(net, w) \ 74 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 75 76 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 77 { 78 write_lock_bh(&net->ipv6.fib6_walker_lock); 79 list_add(&w->lh, &net->ipv6.fib6_walkers); 80 write_unlock_bh(&net->ipv6.fib6_walker_lock); 81 } 82 83 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 84 { 85 write_lock_bh(&net->ipv6.fib6_walker_lock); 86 list_del(&w->lh); 87 write_unlock_bh(&net->ipv6.fib6_walker_lock); 88 } 89 90 static int fib6_new_sernum(struct net *net) 91 { 92 int new, old; 93 94 do { 95 old = atomic_read(&net->ipv6.fib6_sernum); 96 new = old < INT_MAX ? old + 1 : 1; 97 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 98 old, new) != old); 99 return new; 100 } 101 102 enum { 103 FIB6_NO_SERNUM_CHANGE = 0, 104 }; 105 106 void fib6_update_sernum(struct net *net, struct fib6_info *f6i) 107 { 108 struct fib6_node *fn; 109 110 fn = rcu_dereference_protected(f6i->fib6_node, 111 lockdep_is_held(&f6i->fib6_table->tb6_lock)); 112 if (fn) 113 fn->fn_sernum = fib6_new_sernum(net); 114 } 115 116 /* 117 * Auxiliary address test functions for the radix tree. 118 * 119 * These assume a 32bit processor (although it will work on 120 * 64bit processors) 121 */ 122 123 /* 124 * test bit 125 */ 126 #if defined(__LITTLE_ENDIAN) 127 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 128 #else 129 # define BITOP_BE32_SWIZZLE 0 130 #endif 131 132 static __be32 addr_bit_set(const void *token, int fn_bit) 133 { 134 const __be32 *addr = token; 135 /* 136 * Here, 137 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 138 * is optimized version of 139 * htonl(1 << ((~fn_bit)&0x1F)) 140 * See include/asm-generic/bitops/le.h. 141 */ 142 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 143 addr[fn_bit >> 5]; 144 } 145 146 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh) 147 { 148 struct fib6_info *f6i; 149 size_t sz = sizeof(*f6i); 150 151 if (with_fib6_nh) 152 sz += sizeof(struct fib6_nh); 153 154 f6i = kzalloc(sz, gfp_flags); 155 if (!f6i) 156 return NULL; 157 158 /* fib6_siblings is a union with nh_list, so this initializes both */ 159 INIT_LIST_HEAD(&f6i->fib6_siblings); 160 refcount_set(&f6i->fib6_ref, 1); 161 162 return f6i; 163 } 164 165 void fib6_info_destroy_rcu(struct rcu_head *head) 166 { 167 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu); 168 169 WARN_ON(f6i->fib6_node); 170 171 if (f6i->nh) 172 nexthop_put(f6i->nh); 173 else 174 fib6_nh_release(f6i->fib6_nh); 175 176 ip_fib_metrics_put(f6i->fib6_metrics); 177 kfree(f6i); 178 } 179 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); 180 181 static struct fib6_node *node_alloc(struct net *net) 182 { 183 struct fib6_node *fn; 184 185 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 186 if (fn) 187 net->ipv6.rt6_stats->fib_nodes++; 188 189 return fn; 190 } 191 192 static void node_free_immediate(struct net *net, struct fib6_node *fn) 193 { 194 kmem_cache_free(fib6_node_kmem, fn); 195 net->ipv6.rt6_stats->fib_nodes--; 196 } 197 198 static void node_free_rcu(struct rcu_head *head) 199 { 200 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 201 202 kmem_cache_free(fib6_node_kmem, fn); 203 } 204 205 static void node_free(struct net *net, struct fib6_node *fn) 206 { 207 call_rcu(&fn->rcu, node_free_rcu); 208 net->ipv6.rt6_stats->fib_nodes--; 209 } 210 211 static void fib6_free_table(struct fib6_table *table) 212 { 213 inetpeer_invalidate_tree(&table->tb6_peers); 214 kfree(table); 215 } 216 217 static void fib6_link_table(struct net *net, struct fib6_table *tb) 218 { 219 unsigned int h; 220 221 /* 222 * Initialize table lock at a single place to give lockdep a key, 223 * tables aren't visible prior to being linked to the list. 224 */ 225 spin_lock_init(&tb->tb6_lock); 226 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 227 228 /* 229 * No protection necessary, this is the only list mutatation 230 * operation, tables never disappear once they exist. 231 */ 232 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 233 } 234 235 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 236 237 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 238 { 239 struct fib6_table *table; 240 241 table = kzalloc(sizeof(*table), GFP_ATOMIC); 242 if (table) { 243 table->tb6_id = id; 244 rcu_assign_pointer(table->tb6_root.leaf, 245 net->ipv6.fib6_null_entry); 246 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 247 inet_peer_base_init(&table->tb6_peers); 248 } 249 250 return table; 251 } 252 253 struct fib6_table *fib6_new_table(struct net *net, u32 id) 254 { 255 struct fib6_table *tb; 256 257 if (id == 0) 258 id = RT6_TABLE_MAIN; 259 tb = fib6_get_table(net, id); 260 if (tb) 261 return tb; 262 263 tb = fib6_alloc_table(net, id); 264 if (tb) 265 fib6_link_table(net, tb); 266 267 return tb; 268 } 269 EXPORT_SYMBOL_GPL(fib6_new_table); 270 271 struct fib6_table *fib6_get_table(struct net *net, u32 id) 272 { 273 struct fib6_table *tb; 274 struct hlist_head *head; 275 unsigned int h; 276 277 if (id == 0) 278 id = RT6_TABLE_MAIN; 279 h = id & (FIB6_TABLE_HASHSZ - 1); 280 rcu_read_lock(); 281 head = &net->ipv6.fib_table_hash[h]; 282 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 283 if (tb->tb6_id == id) { 284 rcu_read_unlock(); 285 return tb; 286 } 287 } 288 rcu_read_unlock(); 289 290 return NULL; 291 } 292 EXPORT_SYMBOL_GPL(fib6_get_table); 293 294 static void __net_init fib6_tables_init(struct net *net) 295 { 296 fib6_link_table(net, net->ipv6.fib6_main_tbl); 297 fib6_link_table(net, net->ipv6.fib6_local_tbl); 298 } 299 #else 300 301 struct fib6_table *fib6_new_table(struct net *net, u32 id) 302 { 303 return fib6_get_table(net, id); 304 } 305 306 struct fib6_table *fib6_get_table(struct net *net, u32 id) 307 { 308 return net->ipv6.fib6_main_tbl; 309 } 310 311 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 312 const struct sk_buff *skb, 313 int flags, pol_lookup_t lookup) 314 { 315 struct rt6_info *rt; 316 317 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 318 if (rt->dst.error == -EAGAIN) { 319 ip6_rt_put_flags(rt, flags); 320 rt = net->ipv6.ip6_null_entry; 321 if (!(flags | RT6_LOOKUP_F_DST_NOREF)) 322 dst_hold(&rt->dst); 323 } 324 325 return &rt->dst; 326 } 327 328 /* called with rcu lock held; no reference taken on fib6_info */ 329 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 330 struct fib6_result *res, int flags) 331 { 332 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, 333 res, flags); 334 } 335 336 static void __net_init fib6_tables_init(struct net *net) 337 { 338 fib6_link_table(net, net->ipv6.fib6_main_tbl); 339 } 340 341 #endif 342 343 unsigned int fib6_tables_seq_read(struct net *net) 344 { 345 unsigned int h, fib_seq = 0; 346 347 rcu_read_lock(); 348 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 349 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 350 struct fib6_table *tb; 351 352 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 353 fib_seq += tb->fib_seq; 354 } 355 rcu_read_unlock(); 356 357 return fib_seq; 358 } 359 360 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 361 enum fib_event_type event_type, 362 struct fib6_info *rt) 363 { 364 struct fib6_entry_notifier_info info = { 365 .rt = rt, 366 }; 367 368 return call_fib6_notifier(nb, net, event_type, &info.info); 369 } 370 371 int call_fib6_entry_notifiers(struct net *net, 372 enum fib_event_type event_type, 373 struct fib6_info *rt, 374 struct netlink_ext_ack *extack) 375 { 376 struct fib6_entry_notifier_info info = { 377 .info.extack = extack, 378 .rt = rt, 379 }; 380 381 rt->fib6_table->fib_seq++; 382 return call_fib6_notifiers(net, event_type, &info.info); 383 } 384 385 int call_fib6_multipath_entry_notifiers(struct net *net, 386 enum fib_event_type event_type, 387 struct fib6_info *rt, 388 unsigned int nsiblings, 389 struct netlink_ext_ack *extack) 390 { 391 struct fib6_entry_notifier_info info = { 392 .info.extack = extack, 393 .rt = rt, 394 .nsiblings = nsiblings, 395 }; 396 397 rt->fib6_table->fib_seq++; 398 return call_fib6_notifiers(net, event_type, &info.info); 399 } 400 401 struct fib6_dump_arg { 402 struct net *net; 403 struct notifier_block *nb; 404 }; 405 406 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 407 { 408 if (rt == arg->net->ipv6.fib6_null_entry) 409 return; 410 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 411 } 412 413 static int fib6_node_dump(struct fib6_walker *w) 414 { 415 struct fib6_info *rt; 416 417 for_each_fib6_walker_rt(w) 418 fib6_rt_dump(rt, w->args); 419 w->leaf = NULL; 420 return 0; 421 } 422 423 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 424 struct fib6_walker *w) 425 { 426 w->root = &tb->tb6_root; 427 spin_lock_bh(&tb->tb6_lock); 428 fib6_walk(net, w); 429 spin_unlock_bh(&tb->tb6_lock); 430 } 431 432 /* Called with rcu_read_lock() */ 433 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 434 { 435 struct fib6_dump_arg arg; 436 struct fib6_walker *w; 437 unsigned int h; 438 439 w = kzalloc(sizeof(*w), GFP_ATOMIC); 440 if (!w) 441 return -ENOMEM; 442 443 w->func = fib6_node_dump; 444 arg.net = net; 445 arg.nb = nb; 446 w->args = &arg; 447 448 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 449 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 450 struct fib6_table *tb; 451 452 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 453 fib6_table_dump(net, tb, w); 454 } 455 456 kfree(w); 457 458 return 0; 459 } 460 461 static int fib6_dump_node(struct fib6_walker *w) 462 { 463 int res; 464 struct fib6_info *rt; 465 466 for_each_fib6_walker_rt(w) { 467 res = rt6_dump_route(rt, w->args, w->skip_in_node); 468 if (res >= 0) { 469 /* Frame is full, suspend walking */ 470 w->leaf = rt; 471 472 /* We'll restart from this node, so if some routes were 473 * already dumped, skip them next time. 474 */ 475 w->skip_in_node += res; 476 477 return 1; 478 } 479 w->skip_in_node = 0; 480 481 /* Multipath routes are dumped in one route with the 482 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 483 * last sibling of this route (no need to dump the 484 * sibling routes again) 485 */ 486 if (rt->fib6_nsiblings) 487 rt = list_last_entry(&rt->fib6_siblings, 488 struct fib6_info, 489 fib6_siblings); 490 } 491 w->leaf = NULL; 492 return 0; 493 } 494 495 static void fib6_dump_end(struct netlink_callback *cb) 496 { 497 struct net *net = sock_net(cb->skb->sk); 498 struct fib6_walker *w = (void *)cb->args[2]; 499 500 if (w) { 501 if (cb->args[4]) { 502 cb->args[4] = 0; 503 fib6_walker_unlink(net, w); 504 } 505 cb->args[2] = 0; 506 kfree(w); 507 } 508 cb->done = (void *)cb->args[3]; 509 cb->args[1] = 3; 510 } 511 512 static int fib6_dump_done(struct netlink_callback *cb) 513 { 514 fib6_dump_end(cb); 515 return cb->done ? cb->done(cb) : 0; 516 } 517 518 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 519 struct netlink_callback *cb) 520 { 521 struct net *net = sock_net(skb->sk); 522 struct fib6_walker *w; 523 int res; 524 525 w = (void *)cb->args[2]; 526 w->root = &table->tb6_root; 527 528 if (cb->args[4] == 0) { 529 w->count = 0; 530 w->skip = 0; 531 w->skip_in_node = 0; 532 533 spin_lock_bh(&table->tb6_lock); 534 res = fib6_walk(net, w); 535 spin_unlock_bh(&table->tb6_lock); 536 if (res > 0) { 537 cb->args[4] = 1; 538 cb->args[5] = w->root->fn_sernum; 539 } 540 } else { 541 if (cb->args[5] != w->root->fn_sernum) { 542 /* Begin at the root if the tree changed */ 543 cb->args[5] = w->root->fn_sernum; 544 w->state = FWS_INIT; 545 w->node = w->root; 546 w->skip = w->count; 547 w->skip_in_node = 0; 548 } else 549 w->skip = 0; 550 551 spin_lock_bh(&table->tb6_lock); 552 res = fib6_walk_continue(w); 553 spin_unlock_bh(&table->tb6_lock); 554 if (res <= 0) { 555 fib6_walker_unlink(net, w); 556 cb->args[4] = 0; 557 } 558 } 559 560 return res; 561 } 562 563 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 564 { 565 struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true, 566 .filter.dump_routes = true }; 567 const struct nlmsghdr *nlh = cb->nlh; 568 struct net *net = sock_net(skb->sk); 569 unsigned int h, s_h; 570 unsigned int e = 0, s_e; 571 struct fib6_walker *w; 572 struct fib6_table *tb; 573 struct hlist_head *head; 574 int res = 0; 575 576 if (cb->strict_check) { 577 int err; 578 579 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb); 580 if (err < 0) 581 return err; 582 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 583 struct rtmsg *rtm = nlmsg_data(nlh); 584 585 if (rtm->rtm_flags & RTM_F_PREFIX) 586 arg.filter.flags = RTM_F_PREFIX; 587 } 588 589 w = (void *)cb->args[2]; 590 if (!w) { 591 /* New dump: 592 * 593 * 1. hook callback destructor. 594 */ 595 cb->args[3] = (long)cb->done; 596 cb->done = fib6_dump_done; 597 598 /* 599 * 2. allocate and initialize walker. 600 */ 601 w = kzalloc(sizeof(*w), GFP_ATOMIC); 602 if (!w) 603 return -ENOMEM; 604 w->func = fib6_dump_node; 605 cb->args[2] = (long)w; 606 } 607 608 arg.skb = skb; 609 arg.cb = cb; 610 arg.net = net; 611 w->args = &arg; 612 613 if (arg.filter.table_id) { 614 tb = fib6_get_table(net, arg.filter.table_id); 615 if (!tb) { 616 if (arg.filter.dump_all_families) 617 goto out; 618 619 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist"); 620 return -ENOENT; 621 } 622 623 if (!cb->args[0]) { 624 res = fib6_dump_table(tb, skb, cb); 625 if (!res) 626 cb->args[0] = 1; 627 } 628 goto out; 629 } 630 631 s_h = cb->args[0]; 632 s_e = cb->args[1]; 633 634 rcu_read_lock(); 635 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 636 e = 0; 637 head = &net->ipv6.fib_table_hash[h]; 638 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 639 if (e < s_e) 640 goto next; 641 res = fib6_dump_table(tb, skb, cb); 642 if (res != 0) 643 goto out_unlock; 644 next: 645 e++; 646 } 647 } 648 out_unlock: 649 rcu_read_unlock(); 650 cb->args[1] = e; 651 cb->args[0] = h; 652 out: 653 res = res < 0 ? res : skb->len; 654 if (res <= 0) 655 fib6_dump_end(cb); 656 return res; 657 } 658 659 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 660 { 661 if (!f6i) 662 return; 663 664 if (f6i->fib6_metrics == &dst_default_metrics) { 665 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 666 667 if (!p) 668 return; 669 670 refcount_set(&p->refcnt, 1); 671 f6i->fib6_metrics = p; 672 } 673 674 f6i->fib6_metrics->metrics[metric - 1] = val; 675 } 676 677 /* 678 * Routing Table 679 * 680 * return the appropriate node for a routing tree "add" operation 681 * by either creating and inserting or by returning an existing 682 * node. 683 */ 684 685 static struct fib6_node *fib6_add_1(struct net *net, 686 struct fib6_table *table, 687 struct fib6_node *root, 688 struct in6_addr *addr, int plen, 689 int offset, int allow_create, 690 int replace_required, 691 struct netlink_ext_ack *extack) 692 { 693 struct fib6_node *fn, *in, *ln; 694 struct fib6_node *pn = NULL; 695 struct rt6key *key; 696 int bit; 697 __be32 dir = 0; 698 699 RT6_TRACE("fib6_add_1\n"); 700 701 /* insert node in tree */ 702 703 fn = root; 704 705 do { 706 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 707 lockdep_is_held(&table->tb6_lock)); 708 key = (struct rt6key *)((u8 *)leaf + offset); 709 710 /* 711 * Prefix match 712 */ 713 if (plen < fn->fn_bit || 714 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 715 if (!allow_create) { 716 if (replace_required) { 717 NL_SET_ERR_MSG(extack, 718 "Can not replace route - no match found"); 719 pr_warn("Can't replace route, no match found\n"); 720 return ERR_PTR(-ENOENT); 721 } 722 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 723 } 724 goto insert_above; 725 } 726 727 /* 728 * Exact match ? 729 */ 730 731 if (plen == fn->fn_bit) { 732 /* clean up an intermediate node */ 733 if (!(fn->fn_flags & RTN_RTINFO)) { 734 RCU_INIT_POINTER(fn->leaf, NULL); 735 fib6_info_release(leaf); 736 /* remove null_entry in the root node */ 737 } else if (fn->fn_flags & RTN_TL_ROOT && 738 rcu_access_pointer(fn->leaf) == 739 net->ipv6.fib6_null_entry) { 740 RCU_INIT_POINTER(fn->leaf, NULL); 741 } 742 743 return fn; 744 } 745 746 /* 747 * We have more bits to go 748 */ 749 750 /* Try to walk down on tree. */ 751 dir = addr_bit_set(addr, fn->fn_bit); 752 pn = fn; 753 fn = dir ? 754 rcu_dereference_protected(fn->right, 755 lockdep_is_held(&table->tb6_lock)) : 756 rcu_dereference_protected(fn->left, 757 lockdep_is_held(&table->tb6_lock)); 758 } while (fn); 759 760 if (!allow_create) { 761 /* We should not create new node because 762 * NLM_F_REPLACE was specified without NLM_F_CREATE 763 * I assume it is safe to require NLM_F_CREATE when 764 * REPLACE flag is used! Later we may want to remove the 765 * check for replace_required, because according 766 * to netlink specification, NLM_F_CREATE 767 * MUST be specified if new route is created. 768 * That would keep IPv6 consistent with IPv4 769 */ 770 if (replace_required) { 771 NL_SET_ERR_MSG(extack, 772 "Can not replace route - no match found"); 773 pr_warn("Can't replace route, no match found\n"); 774 return ERR_PTR(-ENOENT); 775 } 776 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 777 } 778 /* 779 * We walked to the bottom of tree. 780 * Create new leaf node without children. 781 */ 782 783 ln = node_alloc(net); 784 785 if (!ln) 786 return ERR_PTR(-ENOMEM); 787 ln->fn_bit = plen; 788 RCU_INIT_POINTER(ln->parent, pn); 789 790 if (dir) 791 rcu_assign_pointer(pn->right, ln); 792 else 793 rcu_assign_pointer(pn->left, ln); 794 795 return ln; 796 797 798 insert_above: 799 /* 800 * split since we don't have a common prefix anymore or 801 * we have a less significant route. 802 * we've to insert an intermediate node on the list 803 * this new node will point to the one we need to create 804 * and the current 805 */ 806 807 pn = rcu_dereference_protected(fn->parent, 808 lockdep_is_held(&table->tb6_lock)); 809 810 /* find 1st bit in difference between the 2 addrs. 811 812 See comment in __ipv6_addr_diff: bit may be an invalid value, 813 but if it is >= plen, the value is ignored in any case. 814 */ 815 816 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 817 818 /* 819 * (intermediate)[in] 820 * / \ 821 * (new leaf node)[ln] (old node)[fn] 822 */ 823 if (plen > bit) { 824 in = node_alloc(net); 825 ln = node_alloc(net); 826 827 if (!in || !ln) { 828 if (in) 829 node_free_immediate(net, in); 830 if (ln) 831 node_free_immediate(net, ln); 832 return ERR_PTR(-ENOMEM); 833 } 834 835 /* 836 * new intermediate node. 837 * RTN_RTINFO will 838 * be off since that an address that chooses one of 839 * the branches would not match less specific routes 840 * in the other branch 841 */ 842 843 in->fn_bit = bit; 844 845 RCU_INIT_POINTER(in->parent, pn); 846 in->leaf = fn->leaf; 847 fib6_info_hold(rcu_dereference_protected(in->leaf, 848 lockdep_is_held(&table->tb6_lock))); 849 850 /* update parent pointer */ 851 if (dir) 852 rcu_assign_pointer(pn->right, in); 853 else 854 rcu_assign_pointer(pn->left, in); 855 856 ln->fn_bit = plen; 857 858 RCU_INIT_POINTER(ln->parent, in); 859 rcu_assign_pointer(fn->parent, in); 860 861 if (addr_bit_set(addr, bit)) { 862 rcu_assign_pointer(in->right, ln); 863 rcu_assign_pointer(in->left, fn); 864 } else { 865 rcu_assign_pointer(in->left, ln); 866 rcu_assign_pointer(in->right, fn); 867 } 868 } else { /* plen <= bit */ 869 870 /* 871 * (new leaf node)[ln] 872 * / \ 873 * (old node)[fn] NULL 874 */ 875 876 ln = node_alloc(net); 877 878 if (!ln) 879 return ERR_PTR(-ENOMEM); 880 881 ln->fn_bit = plen; 882 883 RCU_INIT_POINTER(ln->parent, pn); 884 885 if (addr_bit_set(&key->addr, plen)) 886 RCU_INIT_POINTER(ln->right, fn); 887 else 888 RCU_INIT_POINTER(ln->left, fn); 889 890 rcu_assign_pointer(fn->parent, ln); 891 892 if (dir) 893 rcu_assign_pointer(pn->right, ln); 894 else 895 rcu_assign_pointer(pn->left, ln); 896 } 897 return ln; 898 } 899 900 static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh, 901 const struct fib6_info *match, 902 const struct fib6_table *table) 903 { 904 int cpu; 905 906 if (!fib6_nh->rt6i_pcpu) 907 return; 908 909 /* release the reference to this fib entry from 910 * all of its cached pcpu routes 911 */ 912 for_each_possible_cpu(cpu) { 913 struct rt6_info **ppcpu_rt; 914 struct rt6_info *pcpu_rt; 915 916 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); 917 pcpu_rt = *ppcpu_rt; 918 919 /* only dropping the 'from' reference if the cached route 920 * is using 'match'. The cached pcpu_rt->from only changes 921 * from a fib6_info to NULL (ip6_dst_destroy); it can never 922 * change from one fib6_info reference to another 923 */ 924 if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) { 925 struct fib6_info *from; 926 927 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 928 fib6_info_release(from); 929 } 930 } 931 } 932 933 struct fib6_nh_pcpu_arg { 934 struct fib6_info *from; 935 const struct fib6_table *table; 936 }; 937 938 static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg) 939 { 940 struct fib6_nh_pcpu_arg *arg = _arg; 941 942 __fib6_drop_pcpu_from(nh, arg->from, arg->table); 943 return 0; 944 } 945 946 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 947 const struct fib6_table *table) 948 { 949 /* Make sure rt6_make_pcpu_route() wont add other percpu routes 950 * while we are cleaning them here. 951 */ 952 f6i->fib6_destroying = 1; 953 mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */ 954 955 if (f6i->nh) { 956 struct fib6_nh_pcpu_arg arg = { 957 .from = f6i, 958 .table = table 959 }; 960 961 nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from, 962 &arg); 963 } else { 964 struct fib6_nh *fib6_nh; 965 966 fib6_nh = f6i->fib6_nh; 967 __fib6_drop_pcpu_from(fib6_nh, f6i, table); 968 } 969 } 970 971 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 972 struct net *net) 973 { 974 struct fib6_table *table = rt->fib6_table; 975 976 fib6_drop_pcpu_from(rt, table); 977 978 if (rt->nh && !list_empty(&rt->nh_list)) 979 list_del_init(&rt->nh_list); 980 981 if (refcount_read(&rt->fib6_ref) != 1) { 982 /* This route is used as dummy address holder in some split 983 * nodes. It is not leaked, but it still holds other resources, 984 * which must be released in time. So, scan ascendant nodes 985 * and replace dummy references to this route with references 986 * to still alive ones. 987 */ 988 while (fn) { 989 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 990 lockdep_is_held(&table->tb6_lock)); 991 struct fib6_info *new_leaf; 992 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 993 new_leaf = fib6_find_prefix(net, table, fn); 994 fib6_info_hold(new_leaf); 995 996 rcu_assign_pointer(fn->leaf, new_leaf); 997 fib6_info_release(rt); 998 } 999 fn = rcu_dereference_protected(fn->parent, 1000 lockdep_is_held(&table->tb6_lock)); 1001 } 1002 } 1003 } 1004 1005 /* 1006 * Insert routing information in a node. 1007 */ 1008 1009 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 1010 struct nl_info *info, 1011 struct netlink_ext_ack *extack) 1012 { 1013 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 1014 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1015 struct fib6_info *iter = NULL; 1016 struct fib6_info __rcu **ins; 1017 struct fib6_info __rcu **fallback_ins = NULL; 1018 int replace = (info->nlh && 1019 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 1020 int add = (!info->nlh || 1021 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 1022 int found = 0; 1023 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 1024 u16 nlflags = NLM_F_EXCL; 1025 int err; 1026 1027 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 1028 nlflags |= NLM_F_APPEND; 1029 1030 ins = &fn->leaf; 1031 1032 for (iter = leaf; iter; 1033 iter = rcu_dereference_protected(iter->fib6_next, 1034 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 1035 /* 1036 * Search for duplicates 1037 */ 1038 1039 if (iter->fib6_metric == rt->fib6_metric) { 1040 /* 1041 * Same priority level 1042 */ 1043 if (info->nlh && 1044 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 1045 return -EEXIST; 1046 1047 nlflags &= ~NLM_F_EXCL; 1048 if (replace) { 1049 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 1050 found++; 1051 break; 1052 } 1053 if (rt_can_ecmp) 1054 fallback_ins = fallback_ins ?: ins; 1055 goto next_iter; 1056 } 1057 1058 if (rt6_duplicate_nexthop(iter, rt)) { 1059 if (rt->fib6_nsiblings) 1060 rt->fib6_nsiblings = 0; 1061 if (!(iter->fib6_flags & RTF_EXPIRES)) 1062 return -EEXIST; 1063 if (!(rt->fib6_flags & RTF_EXPIRES)) 1064 fib6_clean_expires(iter); 1065 else 1066 fib6_set_expires(iter, rt->expires); 1067 1068 if (rt->fib6_pmtu) 1069 fib6_metric_set(iter, RTAX_MTU, 1070 rt->fib6_pmtu); 1071 return -EEXIST; 1072 } 1073 /* If we have the same destination and the same metric, 1074 * but not the same gateway, then the route we try to 1075 * add is sibling to this route, increment our counter 1076 * of siblings, and later we will add our route to the 1077 * list. 1078 * Only static routes (which don't have flag 1079 * RTF_EXPIRES) are used for ECMPv6. 1080 * 1081 * To avoid long list, we only had siblings if the 1082 * route have a gateway. 1083 */ 1084 if (rt_can_ecmp && 1085 rt6_qualify_for_ecmp(iter)) 1086 rt->fib6_nsiblings++; 1087 } 1088 1089 if (iter->fib6_metric > rt->fib6_metric) 1090 break; 1091 1092 next_iter: 1093 ins = &iter->fib6_next; 1094 } 1095 1096 if (fallback_ins && !found) { 1097 /* No ECMP-able route found, replace first non-ECMP one */ 1098 ins = fallback_ins; 1099 iter = rcu_dereference_protected(*ins, 1100 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1101 found++; 1102 } 1103 1104 /* Reset round-robin state, if necessary */ 1105 if (ins == &fn->leaf) 1106 fn->rr_ptr = NULL; 1107 1108 /* Link this route to others same route. */ 1109 if (rt->fib6_nsiblings) { 1110 unsigned int fib6_nsiblings; 1111 struct fib6_info *sibling, *temp_sibling; 1112 1113 /* Find the first route that have the same metric */ 1114 sibling = leaf; 1115 while (sibling) { 1116 if (sibling->fib6_metric == rt->fib6_metric && 1117 rt6_qualify_for_ecmp(sibling)) { 1118 list_add_tail(&rt->fib6_siblings, 1119 &sibling->fib6_siblings); 1120 break; 1121 } 1122 sibling = rcu_dereference_protected(sibling->fib6_next, 1123 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1124 } 1125 /* For each sibling in the list, increment the counter of 1126 * siblings. BUG() if counters does not match, list of siblings 1127 * is broken! 1128 */ 1129 fib6_nsiblings = 0; 1130 list_for_each_entry_safe(sibling, temp_sibling, 1131 &rt->fib6_siblings, fib6_siblings) { 1132 sibling->fib6_nsiblings++; 1133 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1134 fib6_nsiblings++; 1135 } 1136 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1137 rt6_multipath_rebalance(temp_sibling); 1138 } 1139 1140 /* 1141 * insert node 1142 */ 1143 if (!replace) { 1144 if (!add) 1145 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1146 1147 add: 1148 nlflags |= NLM_F_CREATE; 1149 1150 if (!info->skip_notify_kernel) { 1151 err = call_fib6_entry_notifiers(info->nl_net, 1152 FIB_EVENT_ENTRY_ADD, 1153 rt, extack); 1154 if (err) { 1155 struct fib6_info *sibling, *next_sibling; 1156 1157 /* If the route has siblings, then it first 1158 * needs to be unlinked from them. 1159 */ 1160 if (!rt->fib6_nsiblings) 1161 return err; 1162 1163 list_for_each_entry_safe(sibling, next_sibling, 1164 &rt->fib6_siblings, 1165 fib6_siblings) 1166 sibling->fib6_nsiblings--; 1167 rt->fib6_nsiblings = 0; 1168 list_del_init(&rt->fib6_siblings); 1169 rt6_multipath_rebalance(next_sibling); 1170 return err; 1171 } 1172 } 1173 1174 rcu_assign_pointer(rt->fib6_next, iter); 1175 fib6_info_hold(rt); 1176 rcu_assign_pointer(rt->fib6_node, fn); 1177 rcu_assign_pointer(*ins, rt); 1178 if (!info->skip_notify) 1179 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1180 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1181 1182 if (!(fn->fn_flags & RTN_RTINFO)) { 1183 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1184 fn->fn_flags |= RTN_RTINFO; 1185 } 1186 1187 } else { 1188 int nsiblings; 1189 1190 if (!found) { 1191 if (add) 1192 goto add; 1193 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1194 return -ENOENT; 1195 } 1196 1197 if (!info->skip_notify_kernel) { 1198 err = call_fib6_entry_notifiers(info->nl_net, 1199 FIB_EVENT_ENTRY_REPLACE, 1200 rt, extack); 1201 if (err) 1202 return err; 1203 } 1204 1205 fib6_info_hold(rt); 1206 rcu_assign_pointer(rt->fib6_node, fn); 1207 rt->fib6_next = iter->fib6_next; 1208 rcu_assign_pointer(*ins, rt); 1209 if (!info->skip_notify) 1210 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1211 if (!(fn->fn_flags & RTN_RTINFO)) { 1212 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1213 fn->fn_flags |= RTN_RTINFO; 1214 } 1215 nsiblings = iter->fib6_nsiblings; 1216 iter->fib6_node = NULL; 1217 fib6_purge_rt(iter, fn, info->nl_net); 1218 if (rcu_access_pointer(fn->rr_ptr) == iter) 1219 fn->rr_ptr = NULL; 1220 fib6_info_release(iter); 1221 1222 if (nsiblings) { 1223 /* Replacing an ECMP route, remove all siblings */ 1224 ins = &rt->fib6_next; 1225 iter = rcu_dereference_protected(*ins, 1226 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1227 while (iter) { 1228 if (iter->fib6_metric > rt->fib6_metric) 1229 break; 1230 if (rt6_qualify_for_ecmp(iter)) { 1231 *ins = iter->fib6_next; 1232 iter->fib6_node = NULL; 1233 fib6_purge_rt(iter, fn, info->nl_net); 1234 if (rcu_access_pointer(fn->rr_ptr) == iter) 1235 fn->rr_ptr = NULL; 1236 fib6_info_release(iter); 1237 nsiblings--; 1238 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1239 } else { 1240 ins = &iter->fib6_next; 1241 } 1242 iter = rcu_dereference_protected(*ins, 1243 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1244 } 1245 WARN_ON(nsiblings != 0); 1246 } 1247 } 1248 1249 return 0; 1250 } 1251 1252 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1253 { 1254 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1255 (rt->fib6_flags & RTF_EXPIRES)) 1256 mod_timer(&net->ipv6.ip6_fib_timer, 1257 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1258 } 1259 1260 void fib6_force_start_gc(struct net *net) 1261 { 1262 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1263 mod_timer(&net->ipv6.ip6_fib_timer, 1264 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1265 } 1266 1267 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1268 int sernum) 1269 { 1270 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1271 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1272 1273 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1274 smp_wmb(); 1275 while (fn) { 1276 fn->fn_sernum = sernum; 1277 fn = rcu_dereference_protected(fn->parent, 1278 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1279 } 1280 } 1281 1282 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1283 { 1284 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1285 } 1286 1287 /* allow ipv4 to update sernum via ipv6_stub */ 1288 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i) 1289 { 1290 spin_lock_bh(&f6i->fib6_table->tb6_lock); 1291 fib6_update_sernum_upto_root(net, f6i); 1292 spin_unlock_bh(&f6i->fib6_table->tb6_lock); 1293 } 1294 1295 /* 1296 * Add routing information to the routing tree. 1297 * <destination addr>/<source addr> 1298 * with source addr info in sub-trees 1299 * Need to own table->tb6_lock 1300 */ 1301 1302 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1303 struct nl_info *info, struct netlink_ext_ack *extack) 1304 { 1305 struct fib6_table *table = rt->fib6_table; 1306 struct fib6_node *fn, *pn = NULL; 1307 int err = -ENOMEM; 1308 int allow_create = 1; 1309 int replace_required = 0; 1310 int sernum = fib6_new_sernum(info->nl_net); 1311 1312 if (info->nlh) { 1313 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1314 allow_create = 0; 1315 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1316 replace_required = 1; 1317 } 1318 if (!allow_create && !replace_required) 1319 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1320 1321 fn = fib6_add_1(info->nl_net, table, root, 1322 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1323 offsetof(struct fib6_info, fib6_dst), allow_create, 1324 replace_required, extack); 1325 if (IS_ERR(fn)) { 1326 err = PTR_ERR(fn); 1327 fn = NULL; 1328 goto out; 1329 } 1330 1331 pn = fn; 1332 1333 #ifdef CONFIG_IPV6_SUBTREES 1334 if (rt->fib6_src.plen) { 1335 struct fib6_node *sn; 1336 1337 if (!rcu_access_pointer(fn->subtree)) { 1338 struct fib6_node *sfn; 1339 1340 /* 1341 * Create subtree. 1342 * 1343 * fn[main tree] 1344 * | 1345 * sfn[subtree root] 1346 * \ 1347 * sn[new leaf node] 1348 */ 1349 1350 /* Create subtree root node */ 1351 sfn = node_alloc(info->nl_net); 1352 if (!sfn) 1353 goto failure; 1354 1355 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry); 1356 rcu_assign_pointer(sfn->leaf, 1357 info->nl_net->ipv6.fib6_null_entry); 1358 sfn->fn_flags = RTN_ROOT; 1359 1360 /* Now add the first leaf node to new subtree */ 1361 1362 sn = fib6_add_1(info->nl_net, table, sfn, 1363 &rt->fib6_src.addr, rt->fib6_src.plen, 1364 offsetof(struct fib6_info, fib6_src), 1365 allow_create, replace_required, extack); 1366 1367 if (IS_ERR(sn)) { 1368 /* If it is failed, discard just allocated 1369 root, and then (in failure) stale node 1370 in main tree. 1371 */ 1372 node_free_immediate(info->nl_net, sfn); 1373 err = PTR_ERR(sn); 1374 goto failure; 1375 } 1376 1377 /* Now link new subtree to main tree */ 1378 rcu_assign_pointer(sfn->parent, fn); 1379 rcu_assign_pointer(fn->subtree, sfn); 1380 } else { 1381 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1382 &rt->fib6_src.addr, rt->fib6_src.plen, 1383 offsetof(struct fib6_info, fib6_src), 1384 allow_create, replace_required, extack); 1385 1386 if (IS_ERR(sn)) { 1387 err = PTR_ERR(sn); 1388 goto failure; 1389 } 1390 } 1391 1392 if (!rcu_access_pointer(fn->leaf)) { 1393 if (fn->fn_flags & RTN_TL_ROOT) { 1394 /* put back null_entry for root node */ 1395 rcu_assign_pointer(fn->leaf, 1396 info->nl_net->ipv6.fib6_null_entry); 1397 } else { 1398 fib6_info_hold(rt); 1399 rcu_assign_pointer(fn->leaf, rt); 1400 } 1401 } 1402 fn = sn; 1403 } 1404 #endif 1405 1406 err = fib6_add_rt2node(fn, rt, info, extack); 1407 if (!err) { 1408 if (rt->nh) 1409 list_add(&rt->nh_list, &rt->nh->f6i_list); 1410 __fib6_update_sernum_upto_root(rt, sernum); 1411 fib6_start_gc(info->nl_net, rt); 1412 } 1413 1414 out: 1415 if (err) { 1416 #ifdef CONFIG_IPV6_SUBTREES 1417 /* 1418 * If fib6_add_1 has cleared the old leaf pointer in the 1419 * super-tree leaf node we have to find a new one for it. 1420 */ 1421 if (pn != fn) { 1422 struct fib6_info *pn_leaf = 1423 rcu_dereference_protected(pn->leaf, 1424 lockdep_is_held(&table->tb6_lock)); 1425 if (pn_leaf == rt) { 1426 pn_leaf = NULL; 1427 RCU_INIT_POINTER(pn->leaf, NULL); 1428 fib6_info_release(rt); 1429 } 1430 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1431 pn_leaf = fib6_find_prefix(info->nl_net, table, 1432 pn); 1433 #if RT6_DEBUG >= 2 1434 if (!pn_leaf) { 1435 WARN_ON(!pn_leaf); 1436 pn_leaf = 1437 info->nl_net->ipv6.fib6_null_entry; 1438 } 1439 #endif 1440 fib6_info_hold(pn_leaf); 1441 rcu_assign_pointer(pn->leaf, pn_leaf); 1442 } 1443 } 1444 #endif 1445 goto failure; 1446 } 1447 return err; 1448 1449 failure: 1450 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1451 * 1. fn is an intermediate node and we failed to add the new 1452 * route to it in both subtree creation failure and fib6_add_rt2node() 1453 * failure case. 1454 * 2. fn is the root node in the table and we fail to add the first 1455 * default route to it. 1456 */ 1457 if (fn && 1458 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1459 (fn->fn_flags & RTN_TL_ROOT && 1460 !rcu_access_pointer(fn->leaf)))) 1461 fib6_repair_tree(info->nl_net, table, fn); 1462 return err; 1463 } 1464 1465 /* 1466 * Routing tree lookup 1467 * 1468 */ 1469 1470 struct lookup_args { 1471 int offset; /* key offset on fib6_info */ 1472 const struct in6_addr *addr; /* search key */ 1473 }; 1474 1475 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1476 struct lookup_args *args) 1477 { 1478 struct fib6_node *fn; 1479 __be32 dir; 1480 1481 if (unlikely(args->offset == 0)) 1482 return NULL; 1483 1484 /* 1485 * Descend on a tree 1486 */ 1487 1488 fn = root; 1489 1490 for (;;) { 1491 struct fib6_node *next; 1492 1493 dir = addr_bit_set(args->addr, fn->fn_bit); 1494 1495 next = dir ? rcu_dereference(fn->right) : 1496 rcu_dereference(fn->left); 1497 1498 if (next) { 1499 fn = next; 1500 continue; 1501 } 1502 break; 1503 } 1504 1505 while (fn) { 1506 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1507 1508 if (subtree || fn->fn_flags & RTN_RTINFO) { 1509 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1510 struct rt6key *key; 1511 1512 if (!leaf) 1513 goto backtrack; 1514 1515 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1516 1517 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1518 #ifdef CONFIG_IPV6_SUBTREES 1519 if (subtree) { 1520 struct fib6_node *sfn; 1521 sfn = fib6_node_lookup_1(subtree, 1522 args + 1); 1523 if (!sfn) 1524 goto backtrack; 1525 fn = sfn; 1526 } 1527 #endif 1528 if (fn->fn_flags & RTN_RTINFO) 1529 return fn; 1530 } 1531 } 1532 backtrack: 1533 if (fn->fn_flags & RTN_ROOT) 1534 break; 1535 1536 fn = rcu_dereference(fn->parent); 1537 } 1538 1539 return NULL; 1540 } 1541 1542 /* called with rcu_read_lock() held 1543 */ 1544 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1545 const struct in6_addr *daddr, 1546 const struct in6_addr *saddr) 1547 { 1548 struct fib6_node *fn; 1549 struct lookup_args args[] = { 1550 { 1551 .offset = offsetof(struct fib6_info, fib6_dst), 1552 .addr = daddr, 1553 }, 1554 #ifdef CONFIG_IPV6_SUBTREES 1555 { 1556 .offset = offsetof(struct fib6_info, fib6_src), 1557 .addr = saddr, 1558 }, 1559 #endif 1560 { 1561 .offset = 0, /* sentinel */ 1562 } 1563 }; 1564 1565 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1566 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1567 fn = root; 1568 1569 return fn; 1570 } 1571 1572 /* 1573 * Get node with specified destination prefix (and source prefix, 1574 * if subtrees are used) 1575 * exact_match == true means we try to find fn with exact match of 1576 * the passed in prefix addr 1577 * exact_match == false means we try to find fn with longest prefix 1578 * match of the passed in prefix addr. This is useful for finding fn 1579 * for cached route as it will be stored in the exception table under 1580 * the node with longest prefix length. 1581 */ 1582 1583 1584 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1585 const struct in6_addr *addr, 1586 int plen, int offset, 1587 bool exact_match) 1588 { 1589 struct fib6_node *fn, *prev = NULL; 1590 1591 for (fn = root; fn ; ) { 1592 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1593 struct rt6key *key; 1594 1595 /* This node is being deleted */ 1596 if (!leaf) { 1597 if (plen <= fn->fn_bit) 1598 goto out; 1599 else 1600 goto next; 1601 } 1602 1603 key = (struct rt6key *)((u8 *)leaf + offset); 1604 1605 /* 1606 * Prefix match 1607 */ 1608 if (plen < fn->fn_bit || 1609 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1610 goto out; 1611 1612 if (plen == fn->fn_bit) 1613 return fn; 1614 1615 if (fn->fn_flags & RTN_RTINFO) 1616 prev = fn; 1617 1618 next: 1619 /* 1620 * We have more bits to go 1621 */ 1622 if (addr_bit_set(addr, fn->fn_bit)) 1623 fn = rcu_dereference(fn->right); 1624 else 1625 fn = rcu_dereference(fn->left); 1626 } 1627 out: 1628 if (exact_match) 1629 return NULL; 1630 else 1631 return prev; 1632 } 1633 1634 struct fib6_node *fib6_locate(struct fib6_node *root, 1635 const struct in6_addr *daddr, int dst_len, 1636 const struct in6_addr *saddr, int src_len, 1637 bool exact_match) 1638 { 1639 struct fib6_node *fn; 1640 1641 fn = fib6_locate_1(root, daddr, dst_len, 1642 offsetof(struct fib6_info, fib6_dst), 1643 exact_match); 1644 1645 #ifdef CONFIG_IPV6_SUBTREES 1646 if (src_len) { 1647 WARN_ON(saddr == NULL); 1648 if (fn) { 1649 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1650 1651 if (subtree) { 1652 fn = fib6_locate_1(subtree, saddr, src_len, 1653 offsetof(struct fib6_info, fib6_src), 1654 exact_match); 1655 } 1656 } 1657 } 1658 #endif 1659 1660 if (fn && fn->fn_flags & RTN_RTINFO) 1661 return fn; 1662 1663 return NULL; 1664 } 1665 1666 1667 /* 1668 * Deletion 1669 * 1670 */ 1671 1672 static struct fib6_info *fib6_find_prefix(struct net *net, 1673 struct fib6_table *table, 1674 struct fib6_node *fn) 1675 { 1676 struct fib6_node *child_left, *child_right; 1677 1678 if (fn->fn_flags & RTN_ROOT) 1679 return net->ipv6.fib6_null_entry; 1680 1681 while (fn) { 1682 child_left = rcu_dereference_protected(fn->left, 1683 lockdep_is_held(&table->tb6_lock)); 1684 child_right = rcu_dereference_protected(fn->right, 1685 lockdep_is_held(&table->tb6_lock)); 1686 if (child_left) 1687 return rcu_dereference_protected(child_left->leaf, 1688 lockdep_is_held(&table->tb6_lock)); 1689 if (child_right) 1690 return rcu_dereference_protected(child_right->leaf, 1691 lockdep_is_held(&table->tb6_lock)); 1692 1693 fn = FIB6_SUBTREE(fn); 1694 } 1695 return NULL; 1696 } 1697 1698 /* 1699 * Called to trim the tree of intermediate nodes when possible. "fn" 1700 * is the node we want to try and remove. 1701 * Need to own table->tb6_lock 1702 */ 1703 1704 static struct fib6_node *fib6_repair_tree(struct net *net, 1705 struct fib6_table *table, 1706 struct fib6_node *fn) 1707 { 1708 int children; 1709 int nstate; 1710 struct fib6_node *child; 1711 struct fib6_walker *w; 1712 int iter = 0; 1713 1714 /* Set fn->leaf to null_entry for root node. */ 1715 if (fn->fn_flags & RTN_TL_ROOT) { 1716 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1717 return fn; 1718 } 1719 1720 for (;;) { 1721 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1722 lockdep_is_held(&table->tb6_lock)); 1723 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1724 lockdep_is_held(&table->tb6_lock)); 1725 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1726 lockdep_is_held(&table->tb6_lock)); 1727 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1728 lockdep_is_held(&table->tb6_lock)); 1729 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1730 lockdep_is_held(&table->tb6_lock)); 1731 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1732 lockdep_is_held(&table->tb6_lock)); 1733 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1734 lockdep_is_held(&table->tb6_lock)); 1735 struct fib6_info *new_fn_leaf; 1736 1737 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1738 iter++; 1739 1740 WARN_ON(fn->fn_flags & RTN_RTINFO); 1741 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1742 WARN_ON(fn_leaf); 1743 1744 children = 0; 1745 child = NULL; 1746 if (fn_r) 1747 child = fn_r, children |= 1; 1748 if (fn_l) 1749 child = fn_l, children |= 2; 1750 1751 if (children == 3 || FIB6_SUBTREE(fn) 1752 #ifdef CONFIG_IPV6_SUBTREES 1753 /* Subtree root (i.e. fn) may have one child */ 1754 || (children && fn->fn_flags & RTN_ROOT) 1755 #endif 1756 ) { 1757 new_fn_leaf = fib6_find_prefix(net, table, fn); 1758 #if RT6_DEBUG >= 2 1759 if (!new_fn_leaf) { 1760 WARN_ON(!new_fn_leaf); 1761 new_fn_leaf = net->ipv6.fib6_null_entry; 1762 } 1763 #endif 1764 fib6_info_hold(new_fn_leaf); 1765 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1766 return pn; 1767 } 1768 1769 #ifdef CONFIG_IPV6_SUBTREES 1770 if (FIB6_SUBTREE(pn) == fn) { 1771 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1772 RCU_INIT_POINTER(pn->subtree, NULL); 1773 nstate = FWS_L; 1774 } else { 1775 WARN_ON(fn->fn_flags & RTN_ROOT); 1776 #endif 1777 if (pn_r == fn) 1778 rcu_assign_pointer(pn->right, child); 1779 else if (pn_l == fn) 1780 rcu_assign_pointer(pn->left, child); 1781 #if RT6_DEBUG >= 2 1782 else 1783 WARN_ON(1); 1784 #endif 1785 if (child) 1786 rcu_assign_pointer(child->parent, pn); 1787 nstate = FWS_R; 1788 #ifdef CONFIG_IPV6_SUBTREES 1789 } 1790 #endif 1791 1792 read_lock(&net->ipv6.fib6_walker_lock); 1793 FOR_WALKERS(net, w) { 1794 if (!child) { 1795 if (w->node == fn) { 1796 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1797 w->node = pn; 1798 w->state = nstate; 1799 } 1800 } else { 1801 if (w->node == fn) { 1802 w->node = child; 1803 if (children&2) { 1804 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1805 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1806 } else { 1807 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1808 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1809 } 1810 } 1811 } 1812 } 1813 read_unlock(&net->ipv6.fib6_walker_lock); 1814 1815 node_free(net, fn); 1816 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1817 return pn; 1818 1819 RCU_INIT_POINTER(pn->leaf, NULL); 1820 fib6_info_release(pn_leaf); 1821 fn = pn; 1822 } 1823 } 1824 1825 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1826 struct fib6_info __rcu **rtp, struct nl_info *info) 1827 { 1828 struct fib6_walker *w; 1829 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1830 lockdep_is_held(&table->tb6_lock)); 1831 struct net *net = info->nl_net; 1832 1833 RT6_TRACE("fib6_del_route\n"); 1834 1835 /* Unlink it */ 1836 *rtp = rt->fib6_next; 1837 rt->fib6_node = NULL; 1838 net->ipv6.rt6_stats->fib_rt_entries--; 1839 net->ipv6.rt6_stats->fib_discarded_routes++; 1840 1841 /* Flush all cached dst in exception table */ 1842 rt6_flush_exceptions(rt); 1843 1844 /* Reset round-robin state, if necessary */ 1845 if (rcu_access_pointer(fn->rr_ptr) == rt) 1846 fn->rr_ptr = NULL; 1847 1848 /* Remove this entry from other siblings */ 1849 if (rt->fib6_nsiblings) { 1850 struct fib6_info *sibling, *next_sibling; 1851 1852 list_for_each_entry_safe(sibling, next_sibling, 1853 &rt->fib6_siblings, fib6_siblings) 1854 sibling->fib6_nsiblings--; 1855 rt->fib6_nsiblings = 0; 1856 list_del_init(&rt->fib6_siblings); 1857 rt6_multipath_rebalance(next_sibling); 1858 } 1859 1860 /* Adjust walkers */ 1861 read_lock(&net->ipv6.fib6_walker_lock); 1862 FOR_WALKERS(net, w) { 1863 if (w->state == FWS_C && w->leaf == rt) { 1864 RT6_TRACE("walker %p adjusted by delroute\n", w); 1865 w->leaf = rcu_dereference_protected(rt->fib6_next, 1866 lockdep_is_held(&table->tb6_lock)); 1867 if (!w->leaf) 1868 w->state = FWS_U; 1869 } 1870 } 1871 read_unlock(&net->ipv6.fib6_walker_lock); 1872 1873 /* If it was last route, call fib6_repair_tree() to: 1874 * 1. For root node, put back null_entry as how the table was created. 1875 * 2. For other nodes, expunge its radix tree node. 1876 */ 1877 if (!rcu_access_pointer(fn->leaf)) { 1878 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1879 fn->fn_flags &= ~RTN_RTINFO; 1880 net->ipv6.rt6_stats->fib_route_nodes--; 1881 } 1882 fn = fib6_repair_tree(net, table, fn); 1883 } 1884 1885 fib6_purge_rt(rt, fn, net); 1886 1887 if (!info->skip_notify_kernel) 1888 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1889 if (!info->skip_notify) 1890 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1891 1892 fib6_info_release(rt); 1893 } 1894 1895 /* Need to own table->tb6_lock */ 1896 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1897 { 1898 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1899 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1900 struct fib6_table *table = rt->fib6_table; 1901 struct net *net = info->nl_net; 1902 struct fib6_info __rcu **rtp; 1903 struct fib6_info __rcu **rtp_next; 1904 1905 if (!fn || rt == net->ipv6.fib6_null_entry) 1906 return -ENOENT; 1907 1908 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1909 1910 /* 1911 * Walk the leaf entries looking for ourself 1912 */ 1913 1914 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1915 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1916 lockdep_is_held(&table->tb6_lock)); 1917 if (rt == cur) { 1918 fib6_del_route(table, fn, rtp, info); 1919 return 0; 1920 } 1921 rtp_next = &cur->fib6_next; 1922 } 1923 return -ENOENT; 1924 } 1925 1926 /* 1927 * Tree traversal function. 1928 * 1929 * Certainly, it is not interrupt safe. 1930 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1931 * It means, that we can modify tree during walking 1932 * and use this function for garbage collection, clone pruning, 1933 * cleaning tree when a device goes down etc. etc. 1934 * 1935 * It guarantees that every node will be traversed, 1936 * and that it will be traversed only once. 1937 * 1938 * Callback function w->func may return: 1939 * 0 -> continue walking. 1940 * positive value -> walking is suspended (used by tree dumps, 1941 * and probably by gc, if it will be split to several slices) 1942 * negative value -> terminate walking. 1943 * 1944 * The function itself returns: 1945 * 0 -> walk is complete. 1946 * >0 -> walk is incomplete (i.e. suspended) 1947 * <0 -> walk is terminated by an error. 1948 * 1949 * This function is called with tb6_lock held. 1950 */ 1951 1952 static int fib6_walk_continue(struct fib6_walker *w) 1953 { 1954 struct fib6_node *fn, *pn, *left, *right; 1955 1956 /* w->root should always be table->tb6_root */ 1957 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1958 1959 for (;;) { 1960 fn = w->node; 1961 if (!fn) 1962 return 0; 1963 1964 switch (w->state) { 1965 #ifdef CONFIG_IPV6_SUBTREES 1966 case FWS_S: 1967 if (FIB6_SUBTREE(fn)) { 1968 w->node = FIB6_SUBTREE(fn); 1969 continue; 1970 } 1971 w->state = FWS_L; 1972 #endif 1973 /* fall through */ 1974 case FWS_L: 1975 left = rcu_dereference_protected(fn->left, 1); 1976 if (left) { 1977 w->node = left; 1978 w->state = FWS_INIT; 1979 continue; 1980 } 1981 w->state = FWS_R; 1982 /* fall through */ 1983 case FWS_R: 1984 right = rcu_dereference_protected(fn->right, 1); 1985 if (right) { 1986 w->node = right; 1987 w->state = FWS_INIT; 1988 continue; 1989 } 1990 w->state = FWS_C; 1991 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1992 /* fall through */ 1993 case FWS_C: 1994 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1995 int err; 1996 1997 if (w->skip) { 1998 w->skip--; 1999 goto skip; 2000 } 2001 2002 err = w->func(w); 2003 if (err) 2004 return err; 2005 2006 w->count++; 2007 continue; 2008 } 2009 skip: 2010 w->state = FWS_U; 2011 /* fall through */ 2012 case FWS_U: 2013 if (fn == w->root) 2014 return 0; 2015 pn = rcu_dereference_protected(fn->parent, 1); 2016 left = rcu_dereference_protected(pn->left, 1); 2017 right = rcu_dereference_protected(pn->right, 1); 2018 w->node = pn; 2019 #ifdef CONFIG_IPV6_SUBTREES 2020 if (FIB6_SUBTREE(pn) == fn) { 2021 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 2022 w->state = FWS_L; 2023 continue; 2024 } 2025 #endif 2026 if (left == fn) { 2027 w->state = FWS_R; 2028 continue; 2029 } 2030 if (right == fn) { 2031 w->state = FWS_C; 2032 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 2033 continue; 2034 } 2035 #if RT6_DEBUG >= 2 2036 WARN_ON(1); 2037 #endif 2038 } 2039 } 2040 } 2041 2042 static int fib6_walk(struct net *net, struct fib6_walker *w) 2043 { 2044 int res; 2045 2046 w->state = FWS_INIT; 2047 w->node = w->root; 2048 2049 fib6_walker_link(net, w); 2050 res = fib6_walk_continue(w); 2051 if (res <= 0) 2052 fib6_walker_unlink(net, w); 2053 return res; 2054 } 2055 2056 static int fib6_clean_node(struct fib6_walker *w) 2057 { 2058 int res; 2059 struct fib6_info *rt; 2060 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 2061 struct nl_info info = { 2062 .nl_net = c->net, 2063 .skip_notify = c->skip_notify, 2064 }; 2065 2066 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 2067 w->node->fn_sernum != c->sernum) 2068 w->node->fn_sernum = c->sernum; 2069 2070 if (!c->func) { 2071 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 2072 w->leaf = NULL; 2073 return 0; 2074 } 2075 2076 for_each_fib6_walker_rt(w) { 2077 res = c->func(rt, c->arg); 2078 if (res == -1) { 2079 w->leaf = rt; 2080 res = fib6_del(rt, &info); 2081 if (res) { 2082 #if RT6_DEBUG >= 2 2083 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 2084 __func__, rt, 2085 rcu_access_pointer(rt->fib6_node), 2086 res); 2087 #endif 2088 continue; 2089 } 2090 return 0; 2091 } else if (res == -2) { 2092 if (WARN_ON(!rt->fib6_nsiblings)) 2093 continue; 2094 rt = list_last_entry(&rt->fib6_siblings, 2095 struct fib6_info, fib6_siblings); 2096 continue; 2097 } 2098 WARN_ON(res != 0); 2099 } 2100 w->leaf = rt; 2101 return 0; 2102 } 2103 2104 /* 2105 * Convenient frontend to tree walker. 2106 * 2107 * func is called on each route. 2108 * It may return -2 -> skip multipath route. 2109 * -1 -> delete this route. 2110 * 0 -> continue walking 2111 */ 2112 2113 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2114 int (*func)(struct fib6_info *, void *arg), 2115 int sernum, void *arg, bool skip_notify) 2116 { 2117 struct fib6_cleaner c; 2118 2119 c.w.root = root; 2120 c.w.func = fib6_clean_node; 2121 c.w.count = 0; 2122 c.w.skip = 0; 2123 c.w.skip_in_node = 0; 2124 c.func = func; 2125 c.sernum = sernum; 2126 c.arg = arg; 2127 c.net = net; 2128 c.skip_notify = skip_notify; 2129 2130 fib6_walk(net, &c.w); 2131 } 2132 2133 static void __fib6_clean_all(struct net *net, 2134 int (*func)(struct fib6_info *, void *), 2135 int sernum, void *arg, bool skip_notify) 2136 { 2137 struct fib6_table *table; 2138 struct hlist_head *head; 2139 unsigned int h; 2140 2141 rcu_read_lock(); 2142 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2143 head = &net->ipv6.fib_table_hash[h]; 2144 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2145 spin_lock_bh(&table->tb6_lock); 2146 fib6_clean_tree(net, &table->tb6_root, 2147 func, sernum, arg, skip_notify); 2148 spin_unlock_bh(&table->tb6_lock); 2149 } 2150 } 2151 rcu_read_unlock(); 2152 } 2153 2154 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2155 void *arg) 2156 { 2157 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false); 2158 } 2159 2160 void fib6_clean_all_skip_notify(struct net *net, 2161 int (*func)(struct fib6_info *, void *), 2162 void *arg) 2163 { 2164 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true); 2165 } 2166 2167 static void fib6_flush_trees(struct net *net) 2168 { 2169 int new_sernum = fib6_new_sernum(net); 2170 2171 __fib6_clean_all(net, NULL, new_sernum, NULL, false); 2172 } 2173 2174 /* 2175 * Garbage collection 2176 */ 2177 2178 static int fib6_age(struct fib6_info *rt, void *arg) 2179 { 2180 struct fib6_gc_args *gc_args = arg; 2181 unsigned long now = jiffies; 2182 2183 /* 2184 * check addrconf expiration here. 2185 * Routes are expired even if they are in use. 2186 */ 2187 2188 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2189 if (time_after(now, rt->expires)) { 2190 RT6_TRACE("expiring %p\n", rt); 2191 return -1; 2192 } 2193 gc_args->more++; 2194 } 2195 2196 /* Also age clones in the exception table. 2197 * Note, that clones are aged out 2198 * only if they are not in use now. 2199 */ 2200 rt6_age_exceptions(rt, gc_args, now); 2201 2202 return 0; 2203 } 2204 2205 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2206 { 2207 struct fib6_gc_args gc_args; 2208 unsigned long now; 2209 2210 if (force) { 2211 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2212 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2213 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2214 return; 2215 } 2216 gc_args.timeout = expires ? (int)expires : 2217 net->ipv6.sysctl.ip6_rt_gc_interval; 2218 gc_args.more = 0; 2219 2220 fib6_clean_all(net, fib6_age, &gc_args); 2221 now = jiffies; 2222 net->ipv6.ip6_rt_last_gc = now; 2223 2224 if (gc_args.more) 2225 mod_timer(&net->ipv6.ip6_fib_timer, 2226 round_jiffies(now 2227 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2228 else 2229 del_timer(&net->ipv6.ip6_fib_timer); 2230 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2231 } 2232 2233 static void fib6_gc_timer_cb(struct timer_list *t) 2234 { 2235 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2236 2237 fib6_run_gc(0, arg, true); 2238 } 2239 2240 static int __net_init fib6_net_init(struct net *net) 2241 { 2242 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2243 int err; 2244 2245 err = fib6_notifier_init(net); 2246 if (err) 2247 return err; 2248 2249 spin_lock_init(&net->ipv6.fib6_gc_lock); 2250 rwlock_init(&net->ipv6.fib6_walker_lock); 2251 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2252 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2253 2254 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2255 if (!net->ipv6.rt6_stats) 2256 goto out_timer; 2257 2258 /* Avoid false sharing : Use at least a full cache line */ 2259 size = max_t(size_t, size, L1_CACHE_BYTES); 2260 2261 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2262 if (!net->ipv6.fib_table_hash) 2263 goto out_rt6_stats; 2264 2265 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2266 GFP_KERNEL); 2267 if (!net->ipv6.fib6_main_tbl) 2268 goto out_fib_table_hash; 2269 2270 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2271 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2272 net->ipv6.fib6_null_entry); 2273 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2274 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2275 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2276 2277 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2278 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2279 GFP_KERNEL); 2280 if (!net->ipv6.fib6_local_tbl) 2281 goto out_fib6_main_tbl; 2282 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2283 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2284 net->ipv6.fib6_null_entry); 2285 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2286 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2287 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2288 #endif 2289 fib6_tables_init(net); 2290 2291 return 0; 2292 2293 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2294 out_fib6_main_tbl: 2295 kfree(net->ipv6.fib6_main_tbl); 2296 #endif 2297 out_fib_table_hash: 2298 kfree(net->ipv6.fib_table_hash); 2299 out_rt6_stats: 2300 kfree(net->ipv6.rt6_stats); 2301 out_timer: 2302 fib6_notifier_exit(net); 2303 return -ENOMEM; 2304 } 2305 2306 static void fib6_net_exit(struct net *net) 2307 { 2308 unsigned int i; 2309 2310 del_timer_sync(&net->ipv6.ip6_fib_timer); 2311 2312 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2313 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2314 struct hlist_node *tmp; 2315 struct fib6_table *tb; 2316 2317 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2318 hlist_del(&tb->tb6_hlist); 2319 fib6_free_table(tb); 2320 } 2321 } 2322 2323 kfree(net->ipv6.fib_table_hash); 2324 kfree(net->ipv6.rt6_stats); 2325 fib6_notifier_exit(net); 2326 } 2327 2328 static struct pernet_operations fib6_net_ops = { 2329 .init = fib6_net_init, 2330 .exit = fib6_net_exit, 2331 }; 2332 2333 int __init fib6_init(void) 2334 { 2335 int ret = -ENOMEM; 2336 2337 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2338 sizeof(struct fib6_node), 2339 0, SLAB_HWCACHE_ALIGN, 2340 NULL); 2341 if (!fib6_node_kmem) 2342 goto out; 2343 2344 ret = register_pernet_subsys(&fib6_net_ops); 2345 if (ret) 2346 goto out_kmem_cache_create; 2347 2348 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2349 inet6_dump_fib, 0); 2350 if (ret) 2351 goto out_unregister_subsys; 2352 2353 __fib6_flush_trees = fib6_flush_trees; 2354 out: 2355 return ret; 2356 2357 out_unregister_subsys: 2358 unregister_pernet_subsys(&fib6_net_ops); 2359 out_kmem_cache_create: 2360 kmem_cache_destroy(fib6_node_kmem); 2361 goto out; 2362 } 2363 2364 void fib6_gc_cleanup(void) 2365 { 2366 unregister_pernet_subsys(&fib6_net_ops); 2367 kmem_cache_destroy(fib6_node_kmem); 2368 } 2369 2370 #ifdef CONFIG_PROC_FS 2371 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2372 { 2373 struct fib6_info *rt = v; 2374 struct ipv6_route_iter *iter = seq->private; 2375 struct fib6_nh *fib6_nh = rt->fib6_nh; 2376 unsigned int flags = rt->fib6_flags; 2377 const struct net_device *dev; 2378 2379 if (rt->nh) 2380 fib6_nh = nexthop_fib6_nh(rt->nh); 2381 2382 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2383 2384 #ifdef CONFIG_IPV6_SUBTREES 2385 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2386 #else 2387 seq_puts(seq, "00000000000000000000000000000000 00 "); 2388 #endif 2389 if (fib6_nh->fib_nh_gw_family) { 2390 flags |= RTF_GATEWAY; 2391 seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6); 2392 } else { 2393 seq_puts(seq, "00000000000000000000000000000000"); 2394 } 2395 2396 dev = fib6_nh->fib_nh_dev; 2397 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2398 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0, 2399 flags, dev ? dev->name : ""); 2400 iter->w.leaf = NULL; 2401 return 0; 2402 } 2403 2404 static int ipv6_route_yield(struct fib6_walker *w) 2405 { 2406 struct ipv6_route_iter *iter = w->args; 2407 2408 if (!iter->skip) 2409 return 1; 2410 2411 do { 2412 iter->w.leaf = rcu_dereference_protected( 2413 iter->w.leaf->fib6_next, 2414 lockdep_is_held(&iter->tbl->tb6_lock)); 2415 iter->skip--; 2416 if (!iter->skip && iter->w.leaf) 2417 return 1; 2418 } while (iter->w.leaf); 2419 2420 return 0; 2421 } 2422 2423 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2424 struct net *net) 2425 { 2426 memset(&iter->w, 0, sizeof(iter->w)); 2427 iter->w.func = ipv6_route_yield; 2428 iter->w.root = &iter->tbl->tb6_root; 2429 iter->w.state = FWS_INIT; 2430 iter->w.node = iter->w.root; 2431 iter->w.args = iter; 2432 iter->sernum = iter->w.root->fn_sernum; 2433 INIT_LIST_HEAD(&iter->w.lh); 2434 fib6_walker_link(net, &iter->w); 2435 } 2436 2437 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2438 struct net *net) 2439 { 2440 unsigned int h; 2441 struct hlist_node *node; 2442 2443 if (tbl) { 2444 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2445 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2446 } else { 2447 h = 0; 2448 node = NULL; 2449 } 2450 2451 while (!node && h < FIB6_TABLE_HASHSZ) { 2452 node = rcu_dereference_bh( 2453 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2454 } 2455 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2456 } 2457 2458 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2459 { 2460 if (iter->sernum != iter->w.root->fn_sernum) { 2461 iter->sernum = iter->w.root->fn_sernum; 2462 iter->w.state = FWS_INIT; 2463 iter->w.node = iter->w.root; 2464 WARN_ON(iter->w.skip); 2465 iter->w.skip = iter->w.count; 2466 } 2467 } 2468 2469 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2470 { 2471 int r; 2472 struct fib6_info *n; 2473 struct net *net = seq_file_net(seq); 2474 struct ipv6_route_iter *iter = seq->private; 2475 2476 if (!v) 2477 goto iter_table; 2478 2479 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2480 if (n) { 2481 ++*pos; 2482 return n; 2483 } 2484 2485 iter_table: 2486 ipv6_route_check_sernum(iter); 2487 spin_lock_bh(&iter->tbl->tb6_lock); 2488 r = fib6_walk_continue(&iter->w); 2489 spin_unlock_bh(&iter->tbl->tb6_lock); 2490 if (r > 0) { 2491 if (v) 2492 ++*pos; 2493 return iter->w.leaf; 2494 } else if (r < 0) { 2495 fib6_walker_unlink(net, &iter->w); 2496 return NULL; 2497 } 2498 fib6_walker_unlink(net, &iter->w); 2499 2500 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2501 if (!iter->tbl) 2502 return NULL; 2503 2504 ipv6_route_seq_setup_walk(iter, net); 2505 goto iter_table; 2506 } 2507 2508 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2509 __acquires(RCU_BH) 2510 { 2511 struct net *net = seq_file_net(seq); 2512 struct ipv6_route_iter *iter = seq->private; 2513 2514 rcu_read_lock_bh(); 2515 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2516 iter->skip = *pos; 2517 2518 if (iter->tbl) { 2519 ipv6_route_seq_setup_walk(iter, net); 2520 return ipv6_route_seq_next(seq, NULL, pos); 2521 } else { 2522 return NULL; 2523 } 2524 } 2525 2526 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2527 { 2528 struct fib6_walker *w = &iter->w; 2529 return w->node && !(w->state == FWS_U && w->node == w->root); 2530 } 2531 2532 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2533 __releases(RCU_BH) 2534 { 2535 struct net *net = seq_file_net(seq); 2536 struct ipv6_route_iter *iter = seq->private; 2537 2538 if (ipv6_route_iter_active(iter)) 2539 fib6_walker_unlink(net, &iter->w); 2540 2541 rcu_read_unlock_bh(); 2542 } 2543 2544 const struct seq_operations ipv6_route_seq_ops = { 2545 .start = ipv6_route_seq_start, 2546 .next = ipv6_route_seq_next, 2547 .stop = ipv6_route_seq_stop, 2548 .show = ipv6_route_seq_show 2549 }; 2550 #endif /* CONFIG_PROC_FS */ 2551