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, 361 enum fib_event_type event_type, 362 struct fib6_info *rt, 363 struct netlink_ext_ack *extack) 364 { 365 struct fib6_entry_notifier_info info = { 366 .info.extack = extack, 367 .rt = rt, 368 }; 369 370 return call_fib6_notifier(nb, event_type, &info.info); 371 } 372 373 int call_fib6_entry_notifiers(struct net *net, 374 enum fib_event_type event_type, 375 struct fib6_info *rt, 376 struct netlink_ext_ack *extack) 377 { 378 struct fib6_entry_notifier_info info = { 379 .info.extack = extack, 380 .rt = rt, 381 }; 382 383 rt->fib6_table->fib_seq++; 384 return call_fib6_notifiers(net, event_type, &info.info); 385 } 386 387 int call_fib6_multipath_entry_notifiers(struct net *net, 388 enum fib_event_type event_type, 389 struct fib6_info *rt, 390 unsigned int nsiblings, 391 struct netlink_ext_ack *extack) 392 { 393 struct fib6_entry_notifier_info info = { 394 .info.extack = extack, 395 .rt = rt, 396 .nsiblings = nsiblings, 397 }; 398 399 rt->fib6_table->fib_seq++; 400 return call_fib6_notifiers(net, event_type, &info.info); 401 } 402 403 struct fib6_dump_arg { 404 struct net *net; 405 struct notifier_block *nb; 406 struct netlink_ext_ack *extack; 407 }; 408 409 static int fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 410 { 411 if (rt == arg->net->ipv6.fib6_null_entry) 412 return 0; 413 return call_fib6_entry_notifier(arg->nb, FIB_EVENT_ENTRY_ADD, 414 rt, arg->extack); 415 } 416 417 static int fib6_node_dump(struct fib6_walker *w) 418 { 419 struct fib6_info *rt; 420 int err = 0; 421 422 for_each_fib6_walker_rt(w) { 423 err = fib6_rt_dump(rt, w->args); 424 if (err) 425 break; 426 } 427 w->leaf = NULL; 428 return err; 429 } 430 431 static int fib6_table_dump(struct net *net, struct fib6_table *tb, 432 struct fib6_walker *w) 433 { 434 int err; 435 436 w->root = &tb->tb6_root; 437 spin_lock_bh(&tb->tb6_lock); 438 err = fib6_walk(net, w); 439 spin_unlock_bh(&tb->tb6_lock); 440 return err; 441 } 442 443 /* Called with rcu_read_lock() */ 444 int fib6_tables_dump(struct net *net, struct notifier_block *nb, 445 struct netlink_ext_ack *extack) 446 { 447 struct fib6_dump_arg arg; 448 struct fib6_walker *w; 449 unsigned int h; 450 int err = 0; 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 arg.extack = extack; 460 w->args = &arg; 461 462 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 463 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 464 struct fib6_table *tb; 465 466 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 467 err = fib6_table_dump(net, tb, w); 468 if (err < 0) 469 goto out; 470 } 471 } 472 473 out: 474 kfree(w); 475 476 return err; 477 } 478 479 static int fib6_dump_node(struct fib6_walker *w) 480 { 481 int res; 482 struct fib6_info *rt; 483 484 for_each_fib6_walker_rt(w) { 485 res = rt6_dump_route(rt, w->args, w->skip_in_node); 486 if (res >= 0) { 487 /* Frame is full, suspend walking */ 488 w->leaf = rt; 489 490 /* We'll restart from this node, so if some routes were 491 * already dumped, skip them next time. 492 */ 493 w->skip_in_node += res; 494 495 return 1; 496 } 497 w->skip_in_node = 0; 498 499 /* Multipath routes are dumped in one route with the 500 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 501 * last sibling of this route (no need to dump the 502 * sibling routes again) 503 */ 504 if (rt->fib6_nsiblings) 505 rt = list_last_entry(&rt->fib6_siblings, 506 struct fib6_info, 507 fib6_siblings); 508 } 509 w->leaf = NULL; 510 return 0; 511 } 512 513 static void fib6_dump_end(struct netlink_callback *cb) 514 { 515 struct net *net = sock_net(cb->skb->sk); 516 struct fib6_walker *w = (void *)cb->args[2]; 517 518 if (w) { 519 if (cb->args[4]) { 520 cb->args[4] = 0; 521 fib6_walker_unlink(net, w); 522 } 523 cb->args[2] = 0; 524 kfree(w); 525 } 526 cb->done = (void *)cb->args[3]; 527 cb->args[1] = 3; 528 } 529 530 static int fib6_dump_done(struct netlink_callback *cb) 531 { 532 fib6_dump_end(cb); 533 return cb->done ? cb->done(cb) : 0; 534 } 535 536 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 537 struct netlink_callback *cb) 538 { 539 struct net *net = sock_net(skb->sk); 540 struct fib6_walker *w; 541 int res; 542 543 w = (void *)cb->args[2]; 544 w->root = &table->tb6_root; 545 546 if (cb->args[4] == 0) { 547 w->count = 0; 548 w->skip = 0; 549 w->skip_in_node = 0; 550 551 spin_lock_bh(&table->tb6_lock); 552 res = fib6_walk(net, w); 553 spin_unlock_bh(&table->tb6_lock); 554 if (res > 0) { 555 cb->args[4] = 1; 556 cb->args[5] = w->root->fn_sernum; 557 } 558 } else { 559 if (cb->args[5] != w->root->fn_sernum) { 560 /* Begin at the root if the tree changed */ 561 cb->args[5] = w->root->fn_sernum; 562 w->state = FWS_INIT; 563 w->node = w->root; 564 w->skip = w->count; 565 w->skip_in_node = 0; 566 } else 567 w->skip = 0; 568 569 spin_lock_bh(&table->tb6_lock); 570 res = fib6_walk_continue(w); 571 spin_unlock_bh(&table->tb6_lock); 572 if (res <= 0) { 573 fib6_walker_unlink(net, w); 574 cb->args[4] = 0; 575 } 576 } 577 578 return res; 579 } 580 581 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 582 { 583 struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true, 584 .filter.dump_routes = true }; 585 const struct nlmsghdr *nlh = cb->nlh; 586 struct net *net = sock_net(skb->sk); 587 unsigned int h, s_h; 588 unsigned int e = 0, s_e; 589 struct fib6_walker *w; 590 struct fib6_table *tb; 591 struct hlist_head *head; 592 int res = 0; 593 594 if (cb->strict_check) { 595 int err; 596 597 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb); 598 if (err < 0) 599 return err; 600 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 601 struct rtmsg *rtm = nlmsg_data(nlh); 602 603 if (rtm->rtm_flags & RTM_F_PREFIX) 604 arg.filter.flags = RTM_F_PREFIX; 605 } 606 607 w = (void *)cb->args[2]; 608 if (!w) { 609 /* New dump: 610 * 611 * 1. hook callback destructor. 612 */ 613 cb->args[3] = (long)cb->done; 614 cb->done = fib6_dump_done; 615 616 /* 617 * 2. allocate and initialize walker. 618 */ 619 w = kzalloc(sizeof(*w), GFP_ATOMIC); 620 if (!w) 621 return -ENOMEM; 622 w->func = fib6_dump_node; 623 cb->args[2] = (long)w; 624 } 625 626 arg.skb = skb; 627 arg.cb = cb; 628 arg.net = net; 629 w->args = &arg; 630 631 if (arg.filter.table_id) { 632 tb = fib6_get_table(net, arg.filter.table_id); 633 if (!tb) { 634 if (arg.filter.dump_all_families) 635 goto out; 636 637 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist"); 638 return -ENOENT; 639 } 640 641 if (!cb->args[0]) { 642 res = fib6_dump_table(tb, skb, cb); 643 if (!res) 644 cb->args[0] = 1; 645 } 646 goto out; 647 } 648 649 s_h = cb->args[0]; 650 s_e = cb->args[1]; 651 652 rcu_read_lock(); 653 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 654 e = 0; 655 head = &net->ipv6.fib_table_hash[h]; 656 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 657 if (e < s_e) 658 goto next; 659 res = fib6_dump_table(tb, skb, cb); 660 if (res != 0) 661 goto out_unlock; 662 next: 663 e++; 664 } 665 } 666 out_unlock: 667 rcu_read_unlock(); 668 cb->args[1] = e; 669 cb->args[0] = h; 670 out: 671 res = res < 0 ? res : skb->len; 672 if (res <= 0) 673 fib6_dump_end(cb); 674 return res; 675 } 676 677 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 678 { 679 if (!f6i) 680 return; 681 682 if (f6i->fib6_metrics == &dst_default_metrics) { 683 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 684 685 if (!p) 686 return; 687 688 refcount_set(&p->refcnt, 1); 689 f6i->fib6_metrics = p; 690 } 691 692 f6i->fib6_metrics->metrics[metric - 1] = val; 693 } 694 695 /* 696 * Routing Table 697 * 698 * return the appropriate node for a routing tree "add" operation 699 * by either creating and inserting or by returning an existing 700 * node. 701 */ 702 703 static struct fib6_node *fib6_add_1(struct net *net, 704 struct fib6_table *table, 705 struct fib6_node *root, 706 struct in6_addr *addr, int plen, 707 int offset, int allow_create, 708 int replace_required, 709 struct netlink_ext_ack *extack) 710 { 711 struct fib6_node *fn, *in, *ln; 712 struct fib6_node *pn = NULL; 713 struct rt6key *key; 714 int bit; 715 __be32 dir = 0; 716 717 RT6_TRACE("fib6_add_1\n"); 718 719 /* insert node in tree */ 720 721 fn = root; 722 723 do { 724 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 725 lockdep_is_held(&table->tb6_lock)); 726 key = (struct rt6key *)((u8 *)leaf + offset); 727 728 /* 729 * Prefix match 730 */ 731 if (plen < fn->fn_bit || 732 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 733 if (!allow_create) { 734 if (replace_required) { 735 NL_SET_ERR_MSG(extack, 736 "Can not replace route - no match found"); 737 pr_warn("Can't replace route, no match found\n"); 738 return ERR_PTR(-ENOENT); 739 } 740 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 741 } 742 goto insert_above; 743 } 744 745 /* 746 * Exact match ? 747 */ 748 749 if (plen == fn->fn_bit) { 750 /* clean up an intermediate node */ 751 if (!(fn->fn_flags & RTN_RTINFO)) { 752 RCU_INIT_POINTER(fn->leaf, NULL); 753 fib6_info_release(leaf); 754 /* remove null_entry in the root node */ 755 } else if (fn->fn_flags & RTN_TL_ROOT && 756 rcu_access_pointer(fn->leaf) == 757 net->ipv6.fib6_null_entry) { 758 RCU_INIT_POINTER(fn->leaf, NULL); 759 } 760 761 return fn; 762 } 763 764 /* 765 * We have more bits to go 766 */ 767 768 /* Try to walk down on tree. */ 769 dir = addr_bit_set(addr, fn->fn_bit); 770 pn = fn; 771 fn = dir ? 772 rcu_dereference_protected(fn->right, 773 lockdep_is_held(&table->tb6_lock)) : 774 rcu_dereference_protected(fn->left, 775 lockdep_is_held(&table->tb6_lock)); 776 } while (fn); 777 778 if (!allow_create) { 779 /* We should not create new node because 780 * NLM_F_REPLACE was specified without NLM_F_CREATE 781 * I assume it is safe to require NLM_F_CREATE when 782 * REPLACE flag is used! Later we may want to remove the 783 * check for replace_required, because according 784 * to netlink specification, NLM_F_CREATE 785 * MUST be specified if new route is created. 786 * That would keep IPv6 consistent with IPv4 787 */ 788 if (replace_required) { 789 NL_SET_ERR_MSG(extack, 790 "Can not replace route - no match found"); 791 pr_warn("Can't replace route, no match found\n"); 792 return ERR_PTR(-ENOENT); 793 } 794 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 795 } 796 /* 797 * We walked to the bottom of tree. 798 * Create new leaf node without children. 799 */ 800 801 ln = node_alloc(net); 802 803 if (!ln) 804 return ERR_PTR(-ENOMEM); 805 ln->fn_bit = plen; 806 RCU_INIT_POINTER(ln->parent, pn); 807 808 if (dir) 809 rcu_assign_pointer(pn->right, ln); 810 else 811 rcu_assign_pointer(pn->left, ln); 812 813 return ln; 814 815 816 insert_above: 817 /* 818 * split since we don't have a common prefix anymore or 819 * we have a less significant route. 820 * we've to insert an intermediate node on the list 821 * this new node will point to the one we need to create 822 * and the current 823 */ 824 825 pn = rcu_dereference_protected(fn->parent, 826 lockdep_is_held(&table->tb6_lock)); 827 828 /* find 1st bit in difference between the 2 addrs. 829 830 See comment in __ipv6_addr_diff: bit may be an invalid value, 831 but if it is >= plen, the value is ignored in any case. 832 */ 833 834 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 835 836 /* 837 * (intermediate)[in] 838 * / \ 839 * (new leaf node)[ln] (old node)[fn] 840 */ 841 if (plen > bit) { 842 in = node_alloc(net); 843 ln = node_alloc(net); 844 845 if (!in || !ln) { 846 if (in) 847 node_free_immediate(net, in); 848 if (ln) 849 node_free_immediate(net, ln); 850 return ERR_PTR(-ENOMEM); 851 } 852 853 /* 854 * new intermediate node. 855 * RTN_RTINFO will 856 * be off since that an address that chooses one of 857 * the branches would not match less specific routes 858 * in the other branch 859 */ 860 861 in->fn_bit = bit; 862 863 RCU_INIT_POINTER(in->parent, pn); 864 in->leaf = fn->leaf; 865 fib6_info_hold(rcu_dereference_protected(in->leaf, 866 lockdep_is_held(&table->tb6_lock))); 867 868 /* update parent pointer */ 869 if (dir) 870 rcu_assign_pointer(pn->right, in); 871 else 872 rcu_assign_pointer(pn->left, in); 873 874 ln->fn_bit = plen; 875 876 RCU_INIT_POINTER(ln->parent, in); 877 rcu_assign_pointer(fn->parent, in); 878 879 if (addr_bit_set(addr, bit)) { 880 rcu_assign_pointer(in->right, ln); 881 rcu_assign_pointer(in->left, fn); 882 } else { 883 rcu_assign_pointer(in->left, ln); 884 rcu_assign_pointer(in->right, fn); 885 } 886 } else { /* plen <= bit */ 887 888 /* 889 * (new leaf node)[ln] 890 * / \ 891 * (old node)[fn] NULL 892 */ 893 894 ln = node_alloc(net); 895 896 if (!ln) 897 return ERR_PTR(-ENOMEM); 898 899 ln->fn_bit = plen; 900 901 RCU_INIT_POINTER(ln->parent, pn); 902 903 if (addr_bit_set(&key->addr, plen)) 904 RCU_INIT_POINTER(ln->right, fn); 905 else 906 RCU_INIT_POINTER(ln->left, fn); 907 908 rcu_assign_pointer(fn->parent, ln); 909 910 if (dir) 911 rcu_assign_pointer(pn->right, ln); 912 else 913 rcu_assign_pointer(pn->left, ln); 914 } 915 return ln; 916 } 917 918 static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh, 919 const struct fib6_info *match, 920 const struct fib6_table *table) 921 { 922 int cpu; 923 924 if (!fib6_nh->rt6i_pcpu) 925 return; 926 927 /* release the reference to this fib entry from 928 * all of its cached pcpu routes 929 */ 930 for_each_possible_cpu(cpu) { 931 struct rt6_info **ppcpu_rt; 932 struct rt6_info *pcpu_rt; 933 934 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); 935 pcpu_rt = *ppcpu_rt; 936 937 /* only dropping the 'from' reference if the cached route 938 * is using 'match'. The cached pcpu_rt->from only changes 939 * from a fib6_info to NULL (ip6_dst_destroy); it can never 940 * change from one fib6_info reference to another 941 */ 942 if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) { 943 struct fib6_info *from; 944 945 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 946 fib6_info_release(from); 947 } 948 } 949 } 950 951 struct fib6_nh_pcpu_arg { 952 struct fib6_info *from; 953 const struct fib6_table *table; 954 }; 955 956 static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg) 957 { 958 struct fib6_nh_pcpu_arg *arg = _arg; 959 960 __fib6_drop_pcpu_from(nh, arg->from, arg->table); 961 return 0; 962 } 963 964 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 965 const struct fib6_table *table) 966 { 967 /* Make sure rt6_make_pcpu_route() wont add other percpu routes 968 * while we are cleaning them here. 969 */ 970 f6i->fib6_destroying = 1; 971 mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */ 972 973 if (f6i->nh) { 974 struct fib6_nh_pcpu_arg arg = { 975 .from = f6i, 976 .table = table 977 }; 978 979 nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from, 980 &arg); 981 } else { 982 struct fib6_nh *fib6_nh; 983 984 fib6_nh = f6i->fib6_nh; 985 __fib6_drop_pcpu_from(fib6_nh, f6i, table); 986 } 987 } 988 989 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 990 struct net *net) 991 { 992 struct fib6_table *table = rt->fib6_table; 993 994 fib6_drop_pcpu_from(rt, table); 995 996 if (rt->nh && !list_empty(&rt->nh_list)) 997 list_del_init(&rt->nh_list); 998 999 if (refcount_read(&rt->fib6_ref) != 1) { 1000 /* This route is used as dummy address holder in some split 1001 * nodes. It is not leaked, but it still holds other resources, 1002 * which must be released in time. So, scan ascendant nodes 1003 * and replace dummy references to this route with references 1004 * to still alive ones. 1005 */ 1006 while (fn) { 1007 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 1008 lockdep_is_held(&table->tb6_lock)); 1009 struct fib6_info *new_leaf; 1010 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 1011 new_leaf = fib6_find_prefix(net, table, fn); 1012 fib6_info_hold(new_leaf); 1013 1014 rcu_assign_pointer(fn->leaf, new_leaf); 1015 fib6_info_release(rt); 1016 } 1017 fn = rcu_dereference_protected(fn->parent, 1018 lockdep_is_held(&table->tb6_lock)); 1019 } 1020 } 1021 } 1022 1023 /* 1024 * Insert routing information in a node. 1025 */ 1026 1027 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 1028 struct nl_info *info, 1029 struct netlink_ext_ack *extack) 1030 { 1031 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 1032 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1033 struct fib6_info *iter = NULL; 1034 struct fib6_info __rcu **ins; 1035 struct fib6_info __rcu **fallback_ins = NULL; 1036 int replace = (info->nlh && 1037 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 1038 int add = (!info->nlh || 1039 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 1040 int found = 0; 1041 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 1042 u16 nlflags = NLM_F_EXCL; 1043 int err; 1044 1045 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 1046 nlflags |= NLM_F_APPEND; 1047 1048 ins = &fn->leaf; 1049 1050 for (iter = leaf; iter; 1051 iter = rcu_dereference_protected(iter->fib6_next, 1052 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 1053 /* 1054 * Search for duplicates 1055 */ 1056 1057 if (iter->fib6_metric == rt->fib6_metric) { 1058 /* 1059 * Same priority level 1060 */ 1061 if (info->nlh && 1062 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 1063 return -EEXIST; 1064 1065 nlflags &= ~NLM_F_EXCL; 1066 if (replace) { 1067 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 1068 found++; 1069 break; 1070 } 1071 if (rt_can_ecmp) 1072 fallback_ins = fallback_ins ?: ins; 1073 goto next_iter; 1074 } 1075 1076 if (rt6_duplicate_nexthop(iter, rt)) { 1077 if (rt->fib6_nsiblings) 1078 rt->fib6_nsiblings = 0; 1079 if (!(iter->fib6_flags & RTF_EXPIRES)) 1080 return -EEXIST; 1081 if (!(rt->fib6_flags & RTF_EXPIRES)) 1082 fib6_clean_expires(iter); 1083 else 1084 fib6_set_expires(iter, rt->expires); 1085 1086 if (rt->fib6_pmtu) 1087 fib6_metric_set(iter, RTAX_MTU, 1088 rt->fib6_pmtu); 1089 return -EEXIST; 1090 } 1091 /* If we have the same destination and the same metric, 1092 * but not the same gateway, then the route we try to 1093 * add is sibling to this route, increment our counter 1094 * of siblings, and later we will add our route to the 1095 * list. 1096 * Only static routes (which don't have flag 1097 * RTF_EXPIRES) are used for ECMPv6. 1098 * 1099 * To avoid long list, we only had siblings if the 1100 * route have a gateway. 1101 */ 1102 if (rt_can_ecmp && 1103 rt6_qualify_for_ecmp(iter)) 1104 rt->fib6_nsiblings++; 1105 } 1106 1107 if (iter->fib6_metric > rt->fib6_metric) 1108 break; 1109 1110 next_iter: 1111 ins = &iter->fib6_next; 1112 } 1113 1114 if (fallback_ins && !found) { 1115 /* No ECMP-able route found, replace first non-ECMP one */ 1116 ins = fallback_ins; 1117 iter = rcu_dereference_protected(*ins, 1118 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1119 found++; 1120 } 1121 1122 /* Reset round-robin state, if necessary */ 1123 if (ins == &fn->leaf) 1124 fn->rr_ptr = NULL; 1125 1126 /* Link this route to others same route. */ 1127 if (rt->fib6_nsiblings) { 1128 unsigned int fib6_nsiblings; 1129 struct fib6_info *sibling, *temp_sibling; 1130 1131 /* Find the first route that have the same metric */ 1132 sibling = leaf; 1133 while (sibling) { 1134 if (sibling->fib6_metric == rt->fib6_metric && 1135 rt6_qualify_for_ecmp(sibling)) { 1136 list_add_tail(&rt->fib6_siblings, 1137 &sibling->fib6_siblings); 1138 break; 1139 } 1140 sibling = rcu_dereference_protected(sibling->fib6_next, 1141 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1142 } 1143 /* For each sibling in the list, increment the counter of 1144 * siblings. BUG() if counters does not match, list of siblings 1145 * is broken! 1146 */ 1147 fib6_nsiblings = 0; 1148 list_for_each_entry_safe(sibling, temp_sibling, 1149 &rt->fib6_siblings, fib6_siblings) { 1150 sibling->fib6_nsiblings++; 1151 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1152 fib6_nsiblings++; 1153 } 1154 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1155 rt6_multipath_rebalance(temp_sibling); 1156 } 1157 1158 /* 1159 * insert node 1160 */ 1161 if (!replace) { 1162 if (!add) 1163 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1164 1165 add: 1166 nlflags |= NLM_F_CREATE; 1167 1168 if (!info->skip_notify_kernel) { 1169 err = call_fib6_entry_notifiers(info->nl_net, 1170 FIB_EVENT_ENTRY_ADD, 1171 rt, extack); 1172 if (err) { 1173 struct fib6_info *sibling, *next_sibling; 1174 1175 /* If the route has siblings, then it first 1176 * needs to be unlinked from them. 1177 */ 1178 if (!rt->fib6_nsiblings) 1179 return err; 1180 1181 list_for_each_entry_safe(sibling, next_sibling, 1182 &rt->fib6_siblings, 1183 fib6_siblings) 1184 sibling->fib6_nsiblings--; 1185 rt->fib6_nsiblings = 0; 1186 list_del_init(&rt->fib6_siblings); 1187 rt6_multipath_rebalance(next_sibling); 1188 return err; 1189 } 1190 } 1191 1192 rcu_assign_pointer(rt->fib6_next, iter); 1193 fib6_info_hold(rt); 1194 rcu_assign_pointer(rt->fib6_node, fn); 1195 rcu_assign_pointer(*ins, rt); 1196 if (!info->skip_notify) 1197 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1198 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1199 1200 if (!(fn->fn_flags & RTN_RTINFO)) { 1201 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1202 fn->fn_flags |= RTN_RTINFO; 1203 } 1204 1205 } else { 1206 int nsiblings; 1207 1208 if (!found) { 1209 if (add) 1210 goto add; 1211 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1212 return -ENOENT; 1213 } 1214 1215 if (!info->skip_notify_kernel) { 1216 err = call_fib6_entry_notifiers(info->nl_net, 1217 FIB_EVENT_ENTRY_REPLACE, 1218 rt, extack); 1219 if (err) 1220 return err; 1221 } 1222 1223 fib6_info_hold(rt); 1224 rcu_assign_pointer(rt->fib6_node, fn); 1225 rt->fib6_next = iter->fib6_next; 1226 rcu_assign_pointer(*ins, rt); 1227 if (!info->skip_notify) 1228 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1229 if (!(fn->fn_flags & RTN_RTINFO)) { 1230 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1231 fn->fn_flags |= RTN_RTINFO; 1232 } 1233 nsiblings = iter->fib6_nsiblings; 1234 iter->fib6_node = NULL; 1235 fib6_purge_rt(iter, fn, info->nl_net); 1236 if (rcu_access_pointer(fn->rr_ptr) == iter) 1237 fn->rr_ptr = NULL; 1238 fib6_info_release(iter); 1239 1240 if (nsiblings) { 1241 /* Replacing an ECMP route, remove all siblings */ 1242 ins = &rt->fib6_next; 1243 iter = rcu_dereference_protected(*ins, 1244 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1245 while (iter) { 1246 if (iter->fib6_metric > rt->fib6_metric) 1247 break; 1248 if (rt6_qualify_for_ecmp(iter)) { 1249 *ins = iter->fib6_next; 1250 iter->fib6_node = NULL; 1251 fib6_purge_rt(iter, fn, info->nl_net); 1252 if (rcu_access_pointer(fn->rr_ptr) == iter) 1253 fn->rr_ptr = NULL; 1254 fib6_info_release(iter); 1255 nsiblings--; 1256 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1257 } else { 1258 ins = &iter->fib6_next; 1259 } 1260 iter = rcu_dereference_protected(*ins, 1261 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1262 } 1263 WARN_ON(nsiblings != 0); 1264 } 1265 } 1266 1267 return 0; 1268 } 1269 1270 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1271 { 1272 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1273 (rt->fib6_flags & RTF_EXPIRES)) 1274 mod_timer(&net->ipv6.ip6_fib_timer, 1275 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1276 } 1277 1278 void fib6_force_start_gc(struct net *net) 1279 { 1280 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1281 mod_timer(&net->ipv6.ip6_fib_timer, 1282 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1283 } 1284 1285 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1286 int sernum) 1287 { 1288 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1289 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1290 1291 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1292 smp_wmb(); 1293 while (fn) { 1294 fn->fn_sernum = sernum; 1295 fn = rcu_dereference_protected(fn->parent, 1296 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1297 } 1298 } 1299 1300 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1301 { 1302 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1303 } 1304 1305 /* allow ipv4 to update sernum via ipv6_stub */ 1306 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i) 1307 { 1308 spin_lock_bh(&f6i->fib6_table->tb6_lock); 1309 fib6_update_sernum_upto_root(net, f6i); 1310 spin_unlock_bh(&f6i->fib6_table->tb6_lock); 1311 } 1312 1313 /* 1314 * Add routing information to the routing tree. 1315 * <destination addr>/<source addr> 1316 * with source addr info in sub-trees 1317 * Need to own table->tb6_lock 1318 */ 1319 1320 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1321 struct nl_info *info, struct netlink_ext_ack *extack) 1322 { 1323 struct fib6_table *table = rt->fib6_table; 1324 struct fib6_node *fn, *pn = NULL; 1325 int err = -ENOMEM; 1326 int allow_create = 1; 1327 int replace_required = 0; 1328 int sernum = fib6_new_sernum(info->nl_net); 1329 1330 if (info->nlh) { 1331 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1332 allow_create = 0; 1333 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1334 replace_required = 1; 1335 } 1336 if (!allow_create && !replace_required) 1337 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1338 1339 fn = fib6_add_1(info->nl_net, table, root, 1340 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1341 offsetof(struct fib6_info, fib6_dst), allow_create, 1342 replace_required, extack); 1343 if (IS_ERR(fn)) { 1344 err = PTR_ERR(fn); 1345 fn = NULL; 1346 goto out; 1347 } 1348 1349 pn = fn; 1350 1351 #ifdef CONFIG_IPV6_SUBTREES 1352 if (rt->fib6_src.plen) { 1353 struct fib6_node *sn; 1354 1355 if (!rcu_access_pointer(fn->subtree)) { 1356 struct fib6_node *sfn; 1357 1358 /* 1359 * Create subtree. 1360 * 1361 * fn[main tree] 1362 * | 1363 * sfn[subtree root] 1364 * \ 1365 * sn[new leaf node] 1366 */ 1367 1368 /* Create subtree root node */ 1369 sfn = node_alloc(info->nl_net); 1370 if (!sfn) 1371 goto failure; 1372 1373 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry); 1374 rcu_assign_pointer(sfn->leaf, 1375 info->nl_net->ipv6.fib6_null_entry); 1376 sfn->fn_flags = RTN_ROOT; 1377 1378 /* Now add the first leaf node to new subtree */ 1379 1380 sn = fib6_add_1(info->nl_net, table, sfn, 1381 &rt->fib6_src.addr, rt->fib6_src.plen, 1382 offsetof(struct fib6_info, fib6_src), 1383 allow_create, replace_required, extack); 1384 1385 if (IS_ERR(sn)) { 1386 /* If it is failed, discard just allocated 1387 root, and then (in failure) stale node 1388 in main tree. 1389 */ 1390 node_free_immediate(info->nl_net, sfn); 1391 err = PTR_ERR(sn); 1392 goto failure; 1393 } 1394 1395 /* Now link new subtree to main tree */ 1396 rcu_assign_pointer(sfn->parent, fn); 1397 rcu_assign_pointer(fn->subtree, sfn); 1398 } else { 1399 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1400 &rt->fib6_src.addr, rt->fib6_src.plen, 1401 offsetof(struct fib6_info, fib6_src), 1402 allow_create, replace_required, extack); 1403 1404 if (IS_ERR(sn)) { 1405 err = PTR_ERR(sn); 1406 goto failure; 1407 } 1408 } 1409 1410 if (!rcu_access_pointer(fn->leaf)) { 1411 if (fn->fn_flags & RTN_TL_ROOT) { 1412 /* put back null_entry for root node */ 1413 rcu_assign_pointer(fn->leaf, 1414 info->nl_net->ipv6.fib6_null_entry); 1415 } else { 1416 fib6_info_hold(rt); 1417 rcu_assign_pointer(fn->leaf, rt); 1418 } 1419 } 1420 fn = sn; 1421 } 1422 #endif 1423 1424 err = fib6_add_rt2node(fn, rt, info, extack); 1425 if (!err) { 1426 if (rt->nh) 1427 list_add(&rt->nh_list, &rt->nh->f6i_list); 1428 __fib6_update_sernum_upto_root(rt, sernum); 1429 fib6_start_gc(info->nl_net, rt); 1430 } 1431 1432 out: 1433 if (err) { 1434 #ifdef CONFIG_IPV6_SUBTREES 1435 /* 1436 * If fib6_add_1 has cleared the old leaf pointer in the 1437 * super-tree leaf node we have to find a new one for it. 1438 */ 1439 if (pn != fn) { 1440 struct fib6_info *pn_leaf = 1441 rcu_dereference_protected(pn->leaf, 1442 lockdep_is_held(&table->tb6_lock)); 1443 if (pn_leaf == rt) { 1444 pn_leaf = NULL; 1445 RCU_INIT_POINTER(pn->leaf, NULL); 1446 fib6_info_release(rt); 1447 } 1448 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1449 pn_leaf = fib6_find_prefix(info->nl_net, table, 1450 pn); 1451 #if RT6_DEBUG >= 2 1452 if (!pn_leaf) { 1453 WARN_ON(!pn_leaf); 1454 pn_leaf = 1455 info->nl_net->ipv6.fib6_null_entry; 1456 } 1457 #endif 1458 fib6_info_hold(pn_leaf); 1459 rcu_assign_pointer(pn->leaf, pn_leaf); 1460 } 1461 } 1462 #endif 1463 goto failure; 1464 } 1465 return err; 1466 1467 failure: 1468 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1469 * 1. fn is an intermediate node and we failed to add the new 1470 * route to it in both subtree creation failure and fib6_add_rt2node() 1471 * failure case. 1472 * 2. fn is the root node in the table and we fail to add the first 1473 * default route to it. 1474 */ 1475 if (fn && 1476 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1477 (fn->fn_flags & RTN_TL_ROOT && 1478 !rcu_access_pointer(fn->leaf)))) 1479 fib6_repair_tree(info->nl_net, table, fn); 1480 return err; 1481 } 1482 1483 /* 1484 * Routing tree lookup 1485 * 1486 */ 1487 1488 struct lookup_args { 1489 int offset; /* key offset on fib6_info */ 1490 const struct in6_addr *addr; /* search key */ 1491 }; 1492 1493 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1494 struct lookup_args *args) 1495 { 1496 struct fib6_node *fn; 1497 __be32 dir; 1498 1499 if (unlikely(args->offset == 0)) 1500 return NULL; 1501 1502 /* 1503 * Descend on a tree 1504 */ 1505 1506 fn = root; 1507 1508 for (;;) { 1509 struct fib6_node *next; 1510 1511 dir = addr_bit_set(args->addr, fn->fn_bit); 1512 1513 next = dir ? rcu_dereference(fn->right) : 1514 rcu_dereference(fn->left); 1515 1516 if (next) { 1517 fn = next; 1518 continue; 1519 } 1520 break; 1521 } 1522 1523 while (fn) { 1524 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1525 1526 if (subtree || fn->fn_flags & RTN_RTINFO) { 1527 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1528 struct rt6key *key; 1529 1530 if (!leaf) 1531 goto backtrack; 1532 1533 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1534 1535 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1536 #ifdef CONFIG_IPV6_SUBTREES 1537 if (subtree) { 1538 struct fib6_node *sfn; 1539 sfn = fib6_node_lookup_1(subtree, 1540 args + 1); 1541 if (!sfn) 1542 goto backtrack; 1543 fn = sfn; 1544 } 1545 #endif 1546 if (fn->fn_flags & RTN_RTINFO) 1547 return fn; 1548 } 1549 } 1550 backtrack: 1551 if (fn->fn_flags & RTN_ROOT) 1552 break; 1553 1554 fn = rcu_dereference(fn->parent); 1555 } 1556 1557 return NULL; 1558 } 1559 1560 /* called with rcu_read_lock() held 1561 */ 1562 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1563 const struct in6_addr *daddr, 1564 const struct in6_addr *saddr) 1565 { 1566 struct fib6_node *fn; 1567 struct lookup_args args[] = { 1568 { 1569 .offset = offsetof(struct fib6_info, fib6_dst), 1570 .addr = daddr, 1571 }, 1572 #ifdef CONFIG_IPV6_SUBTREES 1573 { 1574 .offset = offsetof(struct fib6_info, fib6_src), 1575 .addr = saddr, 1576 }, 1577 #endif 1578 { 1579 .offset = 0, /* sentinel */ 1580 } 1581 }; 1582 1583 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1584 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1585 fn = root; 1586 1587 return fn; 1588 } 1589 1590 /* 1591 * Get node with specified destination prefix (and source prefix, 1592 * if subtrees are used) 1593 * exact_match == true means we try to find fn with exact match of 1594 * the passed in prefix addr 1595 * exact_match == false means we try to find fn with longest prefix 1596 * match of the passed in prefix addr. This is useful for finding fn 1597 * for cached route as it will be stored in the exception table under 1598 * the node with longest prefix length. 1599 */ 1600 1601 1602 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1603 const struct in6_addr *addr, 1604 int plen, int offset, 1605 bool exact_match) 1606 { 1607 struct fib6_node *fn, *prev = NULL; 1608 1609 for (fn = root; fn ; ) { 1610 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1611 struct rt6key *key; 1612 1613 /* This node is being deleted */ 1614 if (!leaf) { 1615 if (plen <= fn->fn_bit) 1616 goto out; 1617 else 1618 goto next; 1619 } 1620 1621 key = (struct rt6key *)((u8 *)leaf + offset); 1622 1623 /* 1624 * Prefix match 1625 */ 1626 if (plen < fn->fn_bit || 1627 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1628 goto out; 1629 1630 if (plen == fn->fn_bit) 1631 return fn; 1632 1633 if (fn->fn_flags & RTN_RTINFO) 1634 prev = fn; 1635 1636 next: 1637 /* 1638 * We have more bits to go 1639 */ 1640 if (addr_bit_set(addr, fn->fn_bit)) 1641 fn = rcu_dereference(fn->right); 1642 else 1643 fn = rcu_dereference(fn->left); 1644 } 1645 out: 1646 if (exact_match) 1647 return NULL; 1648 else 1649 return prev; 1650 } 1651 1652 struct fib6_node *fib6_locate(struct fib6_node *root, 1653 const struct in6_addr *daddr, int dst_len, 1654 const struct in6_addr *saddr, int src_len, 1655 bool exact_match) 1656 { 1657 struct fib6_node *fn; 1658 1659 fn = fib6_locate_1(root, daddr, dst_len, 1660 offsetof(struct fib6_info, fib6_dst), 1661 exact_match); 1662 1663 #ifdef CONFIG_IPV6_SUBTREES 1664 if (src_len) { 1665 WARN_ON(saddr == NULL); 1666 if (fn) { 1667 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1668 1669 if (subtree) { 1670 fn = fib6_locate_1(subtree, saddr, src_len, 1671 offsetof(struct fib6_info, fib6_src), 1672 exact_match); 1673 } 1674 } 1675 } 1676 #endif 1677 1678 if (fn && fn->fn_flags & RTN_RTINFO) 1679 return fn; 1680 1681 return NULL; 1682 } 1683 1684 1685 /* 1686 * Deletion 1687 * 1688 */ 1689 1690 static struct fib6_info *fib6_find_prefix(struct net *net, 1691 struct fib6_table *table, 1692 struct fib6_node *fn) 1693 { 1694 struct fib6_node *child_left, *child_right; 1695 1696 if (fn->fn_flags & RTN_ROOT) 1697 return net->ipv6.fib6_null_entry; 1698 1699 while (fn) { 1700 child_left = rcu_dereference_protected(fn->left, 1701 lockdep_is_held(&table->tb6_lock)); 1702 child_right = rcu_dereference_protected(fn->right, 1703 lockdep_is_held(&table->tb6_lock)); 1704 if (child_left) 1705 return rcu_dereference_protected(child_left->leaf, 1706 lockdep_is_held(&table->tb6_lock)); 1707 if (child_right) 1708 return rcu_dereference_protected(child_right->leaf, 1709 lockdep_is_held(&table->tb6_lock)); 1710 1711 fn = FIB6_SUBTREE(fn); 1712 } 1713 return NULL; 1714 } 1715 1716 /* 1717 * Called to trim the tree of intermediate nodes when possible. "fn" 1718 * is the node we want to try and remove. 1719 * Need to own table->tb6_lock 1720 */ 1721 1722 static struct fib6_node *fib6_repair_tree(struct net *net, 1723 struct fib6_table *table, 1724 struct fib6_node *fn) 1725 { 1726 int children; 1727 int nstate; 1728 struct fib6_node *child; 1729 struct fib6_walker *w; 1730 int iter = 0; 1731 1732 /* Set fn->leaf to null_entry for root node. */ 1733 if (fn->fn_flags & RTN_TL_ROOT) { 1734 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1735 return fn; 1736 } 1737 1738 for (;;) { 1739 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1740 lockdep_is_held(&table->tb6_lock)); 1741 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1742 lockdep_is_held(&table->tb6_lock)); 1743 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1744 lockdep_is_held(&table->tb6_lock)); 1745 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1746 lockdep_is_held(&table->tb6_lock)); 1747 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1748 lockdep_is_held(&table->tb6_lock)); 1749 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1750 lockdep_is_held(&table->tb6_lock)); 1751 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1752 lockdep_is_held(&table->tb6_lock)); 1753 struct fib6_info *new_fn_leaf; 1754 1755 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1756 iter++; 1757 1758 WARN_ON(fn->fn_flags & RTN_RTINFO); 1759 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1760 WARN_ON(fn_leaf); 1761 1762 children = 0; 1763 child = NULL; 1764 if (fn_r) 1765 child = fn_r, children |= 1; 1766 if (fn_l) 1767 child = fn_l, children |= 2; 1768 1769 if (children == 3 || FIB6_SUBTREE(fn) 1770 #ifdef CONFIG_IPV6_SUBTREES 1771 /* Subtree root (i.e. fn) may have one child */ 1772 || (children && fn->fn_flags & RTN_ROOT) 1773 #endif 1774 ) { 1775 new_fn_leaf = fib6_find_prefix(net, table, fn); 1776 #if RT6_DEBUG >= 2 1777 if (!new_fn_leaf) { 1778 WARN_ON(!new_fn_leaf); 1779 new_fn_leaf = net->ipv6.fib6_null_entry; 1780 } 1781 #endif 1782 fib6_info_hold(new_fn_leaf); 1783 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1784 return pn; 1785 } 1786 1787 #ifdef CONFIG_IPV6_SUBTREES 1788 if (FIB6_SUBTREE(pn) == fn) { 1789 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1790 RCU_INIT_POINTER(pn->subtree, NULL); 1791 nstate = FWS_L; 1792 } else { 1793 WARN_ON(fn->fn_flags & RTN_ROOT); 1794 #endif 1795 if (pn_r == fn) 1796 rcu_assign_pointer(pn->right, child); 1797 else if (pn_l == fn) 1798 rcu_assign_pointer(pn->left, child); 1799 #if RT6_DEBUG >= 2 1800 else 1801 WARN_ON(1); 1802 #endif 1803 if (child) 1804 rcu_assign_pointer(child->parent, pn); 1805 nstate = FWS_R; 1806 #ifdef CONFIG_IPV6_SUBTREES 1807 } 1808 #endif 1809 1810 read_lock(&net->ipv6.fib6_walker_lock); 1811 FOR_WALKERS(net, w) { 1812 if (!child) { 1813 if (w->node == fn) { 1814 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1815 w->node = pn; 1816 w->state = nstate; 1817 } 1818 } else { 1819 if (w->node == fn) { 1820 w->node = child; 1821 if (children&2) { 1822 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1823 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1824 } else { 1825 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1826 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1827 } 1828 } 1829 } 1830 } 1831 read_unlock(&net->ipv6.fib6_walker_lock); 1832 1833 node_free(net, fn); 1834 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1835 return pn; 1836 1837 RCU_INIT_POINTER(pn->leaf, NULL); 1838 fib6_info_release(pn_leaf); 1839 fn = pn; 1840 } 1841 } 1842 1843 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1844 struct fib6_info __rcu **rtp, struct nl_info *info) 1845 { 1846 struct fib6_walker *w; 1847 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1848 lockdep_is_held(&table->tb6_lock)); 1849 struct net *net = info->nl_net; 1850 1851 RT6_TRACE("fib6_del_route\n"); 1852 1853 /* Unlink it */ 1854 *rtp = rt->fib6_next; 1855 rt->fib6_node = NULL; 1856 net->ipv6.rt6_stats->fib_rt_entries--; 1857 net->ipv6.rt6_stats->fib_discarded_routes++; 1858 1859 /* Flush all cached dst in exception table */ 1860 rt6_flush_exceptions(rt); 1861 1862 /* Reset round-robin state, if necessary */ 1863 if (rcu_access_pointer(fn->rr_ptr) == rt) 1864 fn->rr_ptr = NULL; 1865 1866 /* Remove this entry from other siblings */ 1867 if (rt->fib6_nsiblings) { 1868 struct fib6_info *sibling, *next_sibling; 1869 1870 list_for_each_entry_safe(sibling, next_sibling, 1871 &rt->fib6_siblings, fib6_siblings) 1872 sibling->fib6_nsiblings--; 1873 rt->fib6_nsiblings = 0; 1874 list_del_init(&rt->fib6_siblings); 1875 rt6_multipath_rebalance(next_sibling); 1876 } 1877 1878 /* Adjust walkers */ 1879 read_lock(&net->ipv6.fib6_walker_lock); 1880 FOR_WALKERS(net, w) { 1881 if (w->state == FWS_C && w->leaf == rt) { 1882 RT6_TRACE("walker %p adjusted by delroute\n", w); 1883 w->leaf = rcu_dereference_protected(rt->fib6_next, 1884 lockdep_is_held(&table->tb6_lock)); 1885 if (!w->leaf) 1886 w->state = FWS_U; 1887 } 1888 } 1889 read_unlock(&net->ipv6.fib6_walker_lock); 1890 1891 /* If it was last route, call fib6_repair_tree() to: 1892 * 1. For root node, put back null_entry as how the table was created. 1893 * 2. For other nodes, expunge its radix tree node. 1894 */ 1895 if (!rcu_access_pointer(fn->leaf)) { 1896 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1897 fn->fn_flags &= ~RTN_RTINFO; 1898 net->ipv6.rt6_stats->fib_route_nodes--; 1899 } 1900 fn = fib6_repair_tree(net, table, fn); 1901 } 1902 1903 fib6_purge_rt(rt, fn, net); 1904 1905 if (!info->skip_notify_kernel) 1906 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1907 if (!info->skip_notify) 1908 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1909 1910 fib6_info_release(rt); 1911 } 1912 1913 /* Need to own table->tb6_lock */ 1914 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1915 { 1916 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1917 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1918 struct fib6_table *table = rt->fib6_table; 1919 struct net *net = info->nl_net; 1920 struct fib6_info __rcu **rtp; 1921 struct fib6_info __rcu **rtp_next; 1922 1923 if (!fn || rt == net->ipv6.fib6_null_entry) 1924 return -ENOENT; 1925 1926 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1927 1928 /* 1929 * Walk the leaf entries looking for ourself 1930 */ 1931 1932 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1933 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1934 lockdep_is_held(&table->tb6_lock)); 1935 if (rt == cur) { 1936 fib6_del_route(table, fn, rtp, info); 1937 return 0; 1938 } 1939 rtp_next = &cur->fib6_next; 1940 } 1941 return -ENOENT; 1942 } 1943 1944 /* 1945 * Tree traversal function. 1946 * 1947 * Certainly, it is not interrupt safe. 1948 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1949 * It means, that we can modify tree during walking 1950 * and use this function for garbage collection, clone pruning, 1951 * cleaning tree when a device goes down etc. etc. 1952 * 1953 * It guarantees that every node will be traversed, 1954 * and that it will be traversed only once. 1955 * 1956 * Callback function w->func may return: 1957 * 0 -> continue walking. 1958 * positive value -> walking is suspended (used by tree dumps, 1959 * and probably by gc, if it will be split to several slices) 1960 * negative value -> terminate walking. 1961 * 1962 * The function itself returns: 1963 * 0 -> walk is complete. 1964 * >0 -> walk is incomplete (i.e. suspended) 1965 * <0 -> walk is terminated by an error. 1966 * 1967 * This function is called with tb6_lock held. 1968 */ 1969 1970 static int fib6_walk_continue(struct fib6_walker *w) 1971 { 1972 struct fib6_node *fn, *pn, *left, *right; 1973 1974 /* w->root should always be table->tb6_root */ 1975 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1976 1977 for (;;) { 1978 fn = w->node; 1979 if (!fn) 1980 return 0; 1981 1982 switch (w->state) { 1983 #ifdef CONFIG_IPV6_SUBTREES 1984 case FWS_S: 1985 if (FIB6_SUBTREE(fn)) { 1986 w->node = FIB6_SUBTREE(fn); 1987 continue; 1988 } 1989 w->state = FWS_L; 1990 #endif 1991 /* fall through */ 1992 case FWS_L: 1993 left = rcu_dereference_protected(fn->left, 1); 1994 if (left) { 1995 w->node = left; 1996 w->state = FWS_INIT; 1997 continue; 1998 } 1999 w->state = FWS_R; 2000 /* fall through */ 2001 case FWS_R: 2002 right = rcu_dereference_protected(fn->right, 1); 2003 if (right) { 2004 w->node = right; 2005 w->state = FWS_INIT; 2006 continue; 2007 } 2008 w->state = FWS_C; 2009 w->leaf = rcu_dereference_protected(fn->leaf, 1); 2010 /* fall through */ 2011 case FWS_C: 2012 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 2013 int err; 2014 2015 if (w->skip) { 2016 w->skip--; 2017 goto skip; 2018 } 2019 2020 err = w->func(w); 2021 if (err) 2022 return err; 2023 2024 w->count++; 2025 continue; 2026 } 2027 skip: 2028 w->state = FWS_U; 2029 /* fall through */ 2030 case FWS_U: 2031 if (fn == w->root) 2032 return 0; 2033 pn = rcu_dereference_protected(fn->parent, 1); 2034 left = rcu_dereference_protected(pn->left, 1); 2035 right = rcu_dereference_protected(pn->right, 1); 2036 w->node = pn; 2037 #ifdef CONFIG_IPV6_SUBTREES 2038 if (FIB6_SUBTREE(pn) == fn) { 2039 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 2040 w->state = FWS_L; 2041 continue; 2042 } 2043 #endif 2044 if (left == fn) { 2045 w->state = FWS_R; 2046 continue; 2047 } 2048 if (right == fn) { 2049 w->state = FWS_C; 2050 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 2051 continue; 2052 } 2053 #if RT6_DEBUG >= 2 2054 WARN_ON(1); 2055 #endif 2056 } 2057 } 2058 } 2059 2060 static int fib6_walk(struct net *net, struct fib6_walker *w) 2061 { 2062 int res; 2063 2064 w->state = FWS_INIT; 2065 w->node = w->root; 2066 2067 fib6_walker_link(net, w); 2068 res = fib6_walk_continue(w); 2069 if (res <= 0) 2070 fib6_walker_unlink(net, w); 2071 return res; 2072 } 2073 2074 static int fib6_clean_node(struct fib6_walker *w) 2075 { 2076 int res; 2077 struct fib6_info *rt; 2078 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 2079 struct nl_info info = { 2080 .nl_net = c->net, 2081 .skip_notify = c->skip_notify, 2082 }; 2083 2084 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 2085 w->node->fn_sernum != c->sernum) 2086 w->node->fn_sernum = c->sernum; 2087 2088 if (!c->func) { 2089 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 2090 w->leaf = NULL; 2091 return 0; 2092 } 2093 2094 for_each_fib6_walker_rt(w) { 2095 res = c->func(rt, c->arg); 2096 if (res == -1) { 2097 w->leaf = rt; 2098 res = fib6_del(rt, &info); 2099 if (res) { 2100 #if RT6_DEBUG >= 2 2101 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 2102 __func__, rt, 2103 rcu_access_pointer(rt->fib6_node), 2104 res); 2105 #endif 2106 continue; 2107 } 2108 return 0; 2109 } else if (res == -2) { 2110 if (WARN_ON(!rt->fib6_nsiblings)) 2111 continue; 2112 rt = list_last_entry(&rt->fib6_siblings, 2113 struct fib6_info, fib6_siblings); 2114 continue; 2115 } 2116 WARN_ON(res != 0); 2117 } 2118 w->leaf = rt; 2119 return 0; 2120 } 2121 2122 /* 2123 * Convenient frontend to tree walker. 2124 * 2125 * func is called on each route. 2126 * It may return -2 -> skip multipath route. 2127 * -1 -> delete this route. 2128 * 0 -> continue walking 2129 */ 2130 2131 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2132 int (*func)(struct fib6_info *, void *arg), 2133 int sernum, void *arg, bool skip_notify) 2134 { 2135 struct fib6_cleaner c; 2136 2137 c.w.root = root; 2138 c.w.func = fib6_clean_node; 2139 c.w.count = 0; 2140 c.w.skip = 0; 2141 c.w.skip_in_node = 0; 2142 c.func = func; 2143 c.sernum = sernum; 2144 c.arg = arg; 2145 c.net = net; 2146 c.skip_notify = skip_notify; 2147 2148 fib6_walk(net, &c.w); 2149 } 2150 2151 static void __fib6_clean_all(struct net *net, 2152 int (*func)(struct fib6_info *, void *), 2153 int sernum, void *arg, bool skip_notify) 2154 { 2155 struct fib6_table *table; 2156 struct hlist_head *head; 2157 unsigned int h; 2158 2159 rcu_read_lock(); 2160 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2161 head = &net->ipv6.fib_table_hash[h]; 2162 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2163 spin_lock_bh(&table->tb6_lock); 2164 fib6_clean_tree(net, &table->tb6_root, 2165 func, sernum, arg, skip_notify); 2166 spin_unlock_bh(&table->tb6_lock); 2167 } 2168 } 2169 rcu_read_unlock(); 2170 } 2171 2172 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2173 void *arg) 2174 { 2175 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false); 2176 } 2177 2178 void fib6_clean_all_skip_notify(struct net *net, 2179 int (*func)(struct fib6_info *, void *), 2180 void *arg) 2181 { 2182 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true); 2183 } 2184 2185 static void fib6_flush_trees(struct net *net) 2186 { 2187 int new_sernum = fib6_new_sernum(net); 2188 2189 __fib6_clean_all(net, NULL, new_sernum, NULL, false); 2190 } 2191 2192 /* 2193 * Garbage collection 2194 */ 2195 2196 static int fib6_age(struct fib6_info *rt, void *arg) 2197 { 2198 struct fib6_gc_args *gc_args = arg; 2199 unsigned long now = jiffies; 2200 2201 /* 2202 * check addrconf expiration here. 2203 * Routes are expired even if they are in use. 2204 */ 2205 2206 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2207 if (time_after(now, rt->expires)) { 2208 RT6_TRACE("expiring %p\n", rt); 2209 return -1; 2210 } 2211 gc_args->more++; 2212 } 2213 2214 /* Also age clones in the exception table. 2215 * Note, that clones are aged out 2216 * only if they are not in use now. 2217 */ 2218 rt6_age_exceptions(rt, gc_args, now); 2219 2220 return 0; 2221 } 2222 2223 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2224 { 2225 struct fib6_gc_args gc_args; 2226 unsigned long now; 2227 2228 if (force) { 2229 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2230 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2231 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2232 return; 2233 } 2234 gc_args.timeout = expires ? (int)expires : 2235 net->ipv6.sysctl.ip6_rt_gc_interval; 2236 gc_args.more = 0; 2237 2238 fib6_clean_all(net, fib6_age, &gc_args); 2239 now = jiffies; 2240 net->ipv6.ip6_rt_last_gc = now; 2241 2242 if (gc_args.more) 2243 mod_timer(&net->ipv6.ip6_fib_timer, 2244 round_jiffies(now 2245 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2246 else 2247 del_timer(&net->ipv6.ip6_fib_timer); 2248 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2249 } 2250 2251 static void fib6_gc_timer_cb(struct timer_list *t) 2252 { 2253 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2254 2255 fib6_run_gc(0, arg, true); 2256 } 2257 2258 static int __net_init fib6_net_init(struct net *net) 2259 { 2260 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2261 int err; 2262 2263 err = fib6_notifier_init(net); 2264 if (err) 2265 return err; 2266 2267 spin_lock_init(&net->ipv6.fib6_gc_lock); 2268 rwlock_init(&net->ipv6.fib6_walker_lock); 2269 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2270 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2271 2272 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2273 if (!net->ipv6.rt6_stats) 2274 goto out_timer; 2275 2276 /* Avoid false sharing : Use at least a full cache line */ 2277 size = max_t(size_t, size, L1_CACHE_BYTES); 2278 2279 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2280 if (!net->ipv6.fib_table_hash) 2281 goto out_rt6_stats; 2282 2283 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2284 GFP_KERNEL); 2285 if (!net->ipv6.fib6_main_tbl) 2286 goto out_fib_table_hash; 2287 2288 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2289 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2290 net->ipv6.fib6_null_entry); 2291 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2292 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2293 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2294 2295 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2296 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2297 GFP_KERNEL); 2298 if (!net->ipv6.fib6_local_tbl) 2299 goto out_fib6_main_tbl; 2300 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2301 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2302 net->ipv6.fib6_null_entry); 2303 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2304 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2305 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2306 #endif 2307 fib6_tables_init(net); 2308 2309 return 0; 2310 2311 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2312 out_fib6_main_tbl: 2313 kfree(net->ipv6.fib6_main_tbl); 2314 #endif 2315 out_fib_table_hash: 2316 kfree(net->ipv6.fib_table_hash); 2317 out_rt6_stats: 2318 kfree(net->ipv6.rt6_stats); 2319 out_timer: 2320 fib6_notifier_exit(net); 2321 return -ENOMEM; 2322 } 2323 2324 static void fib6_net_exit(struct net *net) 2325 { 2326 unsigned int i; 2327 2328 del_timer_sync(&net->ipv6.ip6_fib_timer); 2329 2330 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2331 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2332 struct hlist_node *tmp; 2333 struct fib6_table *tb; 2334 2335 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2336 hlist_del(&tb->tb6_hlist); 2337 fib6_free_table(tb); 2338 } 2339 } 2340 2341 kfree(net->ipv6.fib_table_hash); 2342 kfree(net->ipv6.rt6_stats); 2343 fib6_notifier_exit(net); 2344 } 2345 2346 static struct pernet_operations fib6_net_ops = { 2347 .init = fib6_net_init, 2348 .exit = fib6_net_exit, 2349 }; 2350 2351 int __init fib6_init(void) 2352 { 2353 int ret = -ENOMEM; 2354 2355 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2356 sizeof(struct fib6_node), 2357 0, SLAB_HWCACHE_ALIGN, 2358 NULL); 2359 if (!fib6_node_kmem) 2360 goto out; 2361 2362 ret = register_pernet_subsys(&fib6_net_ops); 2363 if (ret) 2364 goto out_kmem_cache_create; 2365 2366 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2367 inet6_dump_fib, 0); 2368 if (ret) 2369 goto out_unregister_subsys; 2370 2371 __fib6_flush_trees = fib6_flush_trees; 2372 out: 2373 return ret; 2374 2375 out_unregister_subsys: 2376 unregister_pernet_subsys(&fib6_net_ops); 2377 out_kmem_cache_create: 2378 kmem_cache_destroy(fib6_node_kmem); 2379 goto out; 2380 } 2381 2382 void fib6_gc_cleanup(void) 2383 { 2384 unregister_pernet_subsys(&fib6_net_ops); 2385 kmem_cache_destroy(fib6_node_kmem); 2386 } 2387 2388 #ifdef CONFIG_PROC_FS 2389 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2390 { 2391 struct fib6_info *rt = v; 2392 struct ipv6_route_iter *iter = seq->private; 2393 struct fib6_nh *fib6_nh = rt->fib6_nh; 2394 unsigned int flags = rt->fib6_flags; 2395 const struct net_device *dev; 2396 2397 if (rt->nh) 2398 fib6_nh = nexthop_fib6_nh(rt->nh); 2399 2400 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2401 2402 #ifdef CONFIG_IPV6_SUBTREES 2403 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2404 #else 2405 seq_puts(seq, "00000000000000000000000000000000 00 "); 2406 #endif 2407 if (fib6_nh->fib_nh_gw_family) { 2408 flags |= RTF_GATEWAY; 2409 seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6); 2410 } else { 2411 seq_puts(seq, "00000000000000000000000000000000"); 2412 } 2413 2414 dev = fib6_nh->fib_nh_dev; 2415 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2416 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0, 2417 flags, dev ? dev->name : ""); 2418 iter->w.leaf = NULL; 2419 return 0; 2420 } 2421 2422 static int ipv6_route_yield(struct fib6_walker *w) 2423 { 2424 struct ipv6_route_iter *iter = w->args; 2425 2426 if (!iter->skip) 2427 return 1; 2428 2429 do { 2430 iter->w.leaf = rcu_dereference_protected( 2431 iter->w.leaf->fib6_next, 2432 lockdep_is_held(&iter->tbl->tb6_lock)); 2433 iter->skip--; 2434 if (!iter->skip && iter->w.leaf) 2435 return 1; 2436 } while (iter->w.leaf); 2437 2438 return 0; 2439 } 2440 2441 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2442 struct net *net) 2443 { 2444 memset(&iter->w, 0, sizeof(iter->w)); 2445 iter->w.func = ipv6_route_yield; 2446 iter->w.root = &iter->tbl->tb6_root; 2447 iter->w.state = FWS_INIT; 2448 iter->w.node = iter->w.root; 2449 iter->w.args = iter; 2450 iter->sernum = iter->w.root->fn_sernum; 2451 INIT_LIST_HEAD(&iter->w.lh); 2452 fib6_walker_link(net, &iter->w); 2453 } 2454 2455 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2456 struct net *net) 2457 { 2458 unsigned int h; 2459 struct hlist_node *node; 2460 2461 if (tbl) { 2462 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2463 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2464 } else { 2465 h = 0; 2466 node = NULL; 2467 } 2468 2469 while (!node && h < FIB6_TABLE_HASHSZ) { 2470 node = rcu_dereference_bh( 2471 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2472 } 2473 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2474 } 2475 2476 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2477 { 2478 if (iter->sernum != iter->w.root->fn_sernum) { 2479 iter->sernum = iter->w.root->fn_sernum; 2480 iter->w.state = FWS_INIT; 2481 iter->w.node = iter->w.root; 2482 WARN_ON(iter->w.skip); 2483 iter->w.skip = iter->w.count; 2484 } 2485 } 2486 2487 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2488 { 2489 int r; 2490 struct fib6_info *n; 2491 struct net *net = seq_file_net(seq); 2492 struct ipv6_route_iter *iter = seq->private; 2493 2494 if (!v) 2495 goto iter_table; 2496 2497 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2498 if (n) { 2499 ++*pos; 2500 return n; 2501 } 2502 2503 iter_table: 2504 ipv6_route_check_sernum(iter); 2505 spin_lock_bh(&iter->tbl->tb6_lock); 2506 r = fib6_walk_continue(&iter->w); 2507 spin_unlock_bh(&iter->tbl->tb6_lock); 2508 if (r > 0) { 2509 if (v) 2510 ++*pos; 2511 return iter->w.leaf; 2512 } else if (r < 0) { 2513 fib6_walker_unlink(net, &iter->w); 2514 return NULL; 2515 } 2516 fib6_walker_unlink(net, &iter->w); 2517 2518 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2519 if (!iter->tbl) 2520 return NULL; 2521 2522 ipv6_route_seq_setup_walk(iter, net); 2523 goto iter_table; 2524 } 2525 2526 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2527 __acquires(RCU_BH) 2528 { 2529 struct net *net = seq_file_net(seq); 2530 struct ipv6_route_iter *iter = seq->private; 2531 2532 rcu_read_lock_bh(); 2533 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2534 iter->skip = *pos; 2535 2536 if (iter->tbl) { 2537 ipv6_route_seq_setup_walk(iter, net); 2538 return ipv6_route_seq_next(seq, NULL, pos); 2539 } else { 2540 return NULL; 2541 } 2542 } 2543 2544 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2545 { 2546 struct fib6_walker *w = &iter->w; 2547 return w->node && !(w->state == FWS_U && w->node == w->root); 2548 } 2549 2550 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2551 __releases(RCU_BH) 2552 { 2553 struct net *net = seq_file_net(seq); 2554 struct ipv6_route_iter *iter = seq->private; 2555 2556 if (ipv6_route_iter_active(iter)) 2557 fib6_walker_unlink(net, &iter->w); 2558 2559 rcu_read_unlock_bh(); 2560 } 2561 2562 const struct seq_operations ipv6_route_seq_ops = { 2563 .start = ipv6_route_seq_start, 2564 .next = ipv6_route_seq_next, 2565 .stop = ipv6_route_seq_stop, 2566 .show = ipv6_route_seq_show 2567 }; 2568 #endif /* CONFIG_PROC_FS */ 2569