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 static int call_fib6_multipath_entry_notifier(struct notifier_block *nb, 374 enum fib_event_type event_type, 375 struct fib6_info *rt, 376 unsigned int nsiblings, 377 struct netlink_ext_ack *extack) 378 { 379 struct fib6_entry_notifier_info info = { 380 .info.extack = extack, 381 .rt = rt, 382 .nsiblings = nsiblings, 383 }; 384 385 return call_fib6_notifier(nb, event_type, &info.info); 386 } 387 388 int call_fib6_entry_notifiers(struct net *net, 389 enum fib_event_type event_type, 390 struct fib6_info *rt, 391 struct netlink_ext_ack *extack) 392 { 393 struct fib6_entry_notifier_info info = { 394 .info.extack = extack, 395 .rt = rt, 396 }; 397 398 rt->fib6_table->fib_seq++; 399 return call_fib6_notifiers(net, event_type, &info.info); 400 } 401 402 int call_fib6_multipath_entry_notifiers(struct net *net, 403 enum fib_event_type event_type, 404 struct fib6_info *rt, 405 unsigned int nsiblings, 406 struct netlink_ext_ack *extack) 407 { 408 struct fib6_entry_notifier_info info = { 409 .info.extack = extack, 410 .rt = rt, 411 .nsiblings = nsiblings, 412 }; 413 414 rt->fib6_table->fib_seq++; 415 return call_fib6_notifiers(net, event_type, &info.info); 416 } 417 418 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt) 419 { 420 struct fib6_entry_notifier_info info = { 421 .rt = rt, 422 .nsiblings = rt->fib6_nsiblings, 423 }; 424 425 rt->fib6_table->fib_seq++; 426 return call_fib6_notifiers(net, FIB_EVENT_ENTRY_REPLACE, &info.info); 427 } 428 429 struct fib6_dump_arg { 430 struct net *net; 431 struct notifier_block *nb; 432 struct netlink_ext_ack *extack; 433 }; 434 435 static int fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 436 { 437 enum fib_event_type fib_event = FIB_EVENT_ENTRY_REPLACE; 438 int err; 439 440 if (!rt || rt == arg->net->ipv6.fib6_null_entry) 441 return 0; 442 443 if (rt->fib6_nsiblings) 444 err = call_fib6_multipath_entry_notifier(arg->nb, fib_event, 445 rt, 446 rt->fib6_nsiblings, 447 arg->extack); 448 else 449 err = call_fib6_entry_notifier(arg->nb, fib_event, rt, 450 arg->extack); 451 452 return err; 453 } 454 455 static int fib6_node_dump(struct fib6_walker *w) 456 { 457 int err; 458 459 err = fib6_rt_dump(w->leaf, w->args); 460 w->leaf = NULL; 461 return err; 462 } 463 464 static int fib6_table_dump(struct net *net, struct fib6_table *tb, 465 struct fib6_walker *w) 466 { 467 int err; 468 469 w->root = &tb->tb6_root; 470 spin_lock_bh(&tb->tb6_lock); 471 err = fib6_walk(net, w); 472 spin_unlock_bh(&tb->tb6_lock); 473 return err; 474 } 475 476 /* Called with rcu_read_lock() */ 477 int fib6_tables_dump(struct net *net, struct notifier_block *nb, 478 struct netlink_ext_ack *extack) 479 { 480 struct fib6_dump_arg arg; 481 struct fib6_walker *w; 482 unsigned int h; 483 int err = 0; 484 485 w = kzalloc(sizeof(*w), GFP_ATOMIC); 486 if (!w) 487 return -ENOMEM; 488 489 w->func = fib6_node_dump; 490 arg.net = net; 491 arg.nb = nb; 492 arg.extack = extack; 493 w->args = &arg; 494 495 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 496 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 497 struct fib6_table *tb; 498 499 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 500 err = fib6_table_dump(net, tb, w); 501 if (err < 0) 502 goto out; 503 } 504 } 505 506 out: 507 kfree(w); 508 509 return err; 510 } 511 512 static int fib6_dump_node(struct fib6_walker *w) 513 { 514 int res; 515 struct fib6_info *rt; 516 517 for_each_fib6_walker_rt(w) { 518 res = rt6_dump_route(rt, w->args, w->skip_in_node); 519 if (res >= 0) { 520 /* Frame is full, suspend walking */ 521 w->leaf = rt; 522 523 /* We'll restart from this node, so if some routes were 524 * already dumped, skip them next time. 525 */ 526 w->skip_in_node += res; 527 528 return 1; 529 } 530 w->skip_in_node = 0; 531 532 /* Multipath routes are dumped in one route with the 533 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 534 * last sibling of this route (no need to dump the 535 * sibling routes again) 536 */ 537 if (rt->fib6_nsiblings) 538 rt = list_last_entry(&rt->fib6_siblings, 539 struct fib6_info, 540 fib6_siblings); 541 } 542 w->leaf = NULL; 543 return 0; 544 } 545 546 static void fib6_dump_end(struct netlink_callback *cb) 547 { 548 struct net *net = sock_net(cb->skb->sk); 549 struct fib6_walker *w = (void *)cb->args[2]; 550 551 if (w) { 552 if (cb->args[4]) { 553 cb->args[4] = 0; 554 fib6_walker_unlink(net, w); 555 } 556 cb->args[2] = 0; 557 kfree(w); 558 } 559 cb->done = (void *)cb->args[3]; 560 cb->args[1] = 3; 561 } 562 563 static int fib6_dump_done(struct netlink_callback *cb) 564 { 565 fib6_dump_end(cb); 566 return cb->done ? cb->done(cb) : 0; 567 } 568 569 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 570 struct netlink_callback *cb) 571 { 572 struct net *net = sock_net(skb->sk); 573 struct fib6_walker *w; 574 int res; 575 576 w = (void *)cb->args[2]; 577 w->root = &table->tb6_root; 578 579 if (cb->args[4] == 0) { 580 w->count = 0; 581 w->skip = 0; 582 w->skip_in_node = 0; 583 584 spin_lock_bh(&table->tb6_lock); 585 res = fib6_walk(net, w); 586 spin_unlock_bh(&table->tb6_lock); 587 if (res > 0) { 588 cb->args[4] = 1; 589 cb->args[5] = w->root->fn_sernum; 590 } 591 } else { 592 if (cb->args[5] != w->root->fn_sernum) { 593 /* Begin at the root if the tree changed */ 594 cb->args[5] = w->root->fn_sernum; 595 w->state = FWS_INIT; 596 w->node = w->root; 597 w->skip = w->count; 598 w->skip_in_node = 0; 599 } else 600 w->skip = 0; 601 602 spin_lock_bh(&table->tb6_lock); 603 res = fib6_walk_continue(w); 604 spin_unlock_bh(&table->tb6_lock); 605 if (res <= 0) { 606 fib6_walker_unlink(net, w); 607 cb->args[4] = 0; 608 } 609 } 610 611 return res; 612 } 613 614 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 615 { 616 struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true, 617 .filter.dump_routes = true }; 618 const struct nlmsghdr *nlh = cb->nlh; 619 struct net *net = sock_net(skb->sk); 620 unsigned int h, s_h; 621 unsigned int e = 0, s_e; 622 struct fib6_walker *w; 623 struct fib6_table *tb; 624 struct hlist_head *head; 625 int res = 0; 626 627 if (cb->strict_check) { 628 int err; 629 630 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb); 631 if (err < 0) 632 return err; 633 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 634 struct rtmsg *rtm = nlmsg_data(nlh); 635 636 if (rtm->rtm_flags & RTM_F_PREFIX) 637 arg.filter.flags = RTM_F_PREFIX; 638 } 639 640 w = (void *)cb->args[2]; 641 if (!w) { 642 /* New dump: 643 * 644 * 1. hook callback destructor. 645 */ 646 cb->args[3] = (long)cb->done; 647 cb->done = fib6_dump_done; 648 649 /* 650 * 2. allocate and initialize walker. 651 */ 652 w = kzalloc(sizeof(*w), GFP_ATOMIC); 653 if (!w) 654 return -ENOMEM; 655 w->func = fib6_dump_node; 656 cb->args[2] = (long)w; 657 } 658 659 arg.skb = skb; 660 arg.cb = cb; 661 arg.net = net; 662 w->args = &arg; 663 664 if (arg.filter.table_id) { 665 tb = fib6_get_table(net, arg.filter.table_id); 666 if (!tb) { 667 if (arg.filter.dump_all_families) 668 goto out; 669 670 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist"); 671 return -ENOENT; 672 } 673 674 if (!cb->args[0]) { 675 res = fib6_dump_table(tb, skb, cb); 676 if (!res) 677 cb->args[0] = 1; 678 } 679 goto out; 680 } 681 682 s_h = cb->args[0]; 683 s_e = cb->args[1]; 684 685 rcu_read_lock(); 686 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 687 e = 0; 688 head = &net->ipv6.fib_table_hash[h]; 689 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 690 if (e < s_e) 691 goto next; 692 res = fib6_dump_table(tb, skb, cb); 693 if (res != 0) 694 goto out_unlock; 695 next: 696 e++; 697 } 698 } 699 out_unlock: 700 rcu_read_unlock(); 701 cb->args[1] = e; 702 cb->args[0] = h; 703 out: 704 res = res < 0 ? res : skb->len; 705 if (res <= 0) 706 fib6_dump_end(cb); 707 return res; 708 } 709 710 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 711 { 712 if (!f6i) 713 return; 714 715 if (f6i->fib6_metrics == &dst_default_metrics) { 716 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 717 718 if (!p) 719 return; 720 721 refcount_set(&p->refcnt, 1); 722 f6i->fib6_metrics = p; 723 } 724 725 f6i->fib6_metrics->metrics[metric - 1] = val; 726 } 727 728 /* 729 * Routing Table 730 * 731 * return the appropriate node for a routing tree "add" operation 732 * by either creating and inserting or by returning an existing 733 * node. 734 */ 735 736 static struct fib6_node *fib6_add_1(struct net *net, 737 struct fib6_table *table, 738 struct fib6_node *root, 739 struct in6_addr *addr, int plen, 740 int offset, int allow_create, 741 int replace_required, 742 struct netlink_ext_ack *extack) 743 { 744 struct fib6_node *fn, *in, *ln; 745 struct fib6_node *pn = NULL; 746 struct rt6key *key; 747 int bit; 748 __be32 dir = 0; 749 750 RT6_TRACE("fib6_add_1\n"); 751 752 /* insert node in tree */ 753 754 fn = root; 755 756 do { 757 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 758 lockdep_is_held(&table->tb6_lock)); 759 key = (struct rt6key *)((u8 *)leaf + offset); 760 761 /* 762 * Prefix match 763 */ 764 if (plen < fn->fn_bit || 765 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 766 if (!allow_create) { 767 if (replace_required) { 768 NL_SET_ERR_MSG(extack, 769 "Can not replace route - no match found"); 770 pr_warn("Can't replace route, no match found\n"); 771 return ERR_PTR(-ENOENT); 772 } 773 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 774 } 775 goto insert_above; 776 } 777 778 /* 779 * Exact match ? 780 */ 781 782 if (plen == fn->fn_bit) { 783 /* clean up an intermediate node */ 784 if (!(fn->fn_flags & RTN_RTINFO)) { 785 RCU_INIT_POINTER(fn->leaf, NULL); 786 fib6_info_release(leaf); 787 /* remove null_entry in the root node */ 788 } else if (fn->fn_flags & RTN_TL_ROOT && 789 rcu_access_pointer(fn->leaf) == 790 net->ipv6.fib6_null_entry) { 791 RCU_INIT_POINTER(fn->leaf, NULL); 792 } 793 794 return fn; 795 } 796 797 /* 798 * We have more bits to go 799 */ 800 801 /* Try to walk down on tree. */ 802 dir = addr_bit_set(addr, fn->fn_bit); 803 pn = fn; 804 fn = dir ? 805 rcu_dereference_protected(fn->right, 806 lockdep_is_held(&table->tb6_lock)) : 807 rcu_dereference_protected(fn->left, 808 lockdep_is_held(&table->tb6_lock)); 809 } while (fn); 810 811 if (!allow_create) { 812 /* We should not create new node because 813 * NLM_F_REPLACE was specified without NLM_F_CREATE 814 * I assume it is safe to require NLM_F_CREATE when 815 * REPLACE flag is used! Later we may want to remove the 816 * check for replace_required, because according 817 * to netlink specification, NLM_F_CREATE 818 * MUST be specified if new route is created. 819 * That would keep IPv6 consistent with IPv4 820 */ 821 if (replace_required) { 822 NL_SET_ERR_MSG(extack, 823 "Can not replace route - no match found"); 824 pr_warn("Can't replace route, no match found\n"); 825 return ERR_PTR(-ENOENT); 826 } 827 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 828 } 829 /* 830 * We walked to the bottom of tree. 831 * Create new leaf node without children. 832 */ 833 834 ln = node_alloc(net); 835 836 if (!ln) 837 return ERR_PTR(-ENOMEM); 838 ln->fn_bit = plen; 839 RCU_INIT_POINTER(ln->parent, pn); 840 841 if (dir) 842 rcu_assign_pointer(pn->right, ln); 843 else 844 rcu_assign_pointer(pn->left, ln); 845 846 return ln; 847 848 849 insert_above: 850 /* 851 * split since we don't have a common prefix anymore or 852 * we have a less significant route. 853 * we've to insert an intermediate node on the list 854 * this new node will point to the one we need to create 855 * and the current 856 */ 857 858 pn = rcu_dereference_protected(fn->parent, 859 lockdep_is_held(&table->tb6_lock)); 860 861 /* find 1st bit in difference between the 2 addrs. 862 863 See comment in __ipv6_addr_diff: bit may be an invalid value, 864 but if it is >= plen, the value is ignored in any case. 865 */ 866 867 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 868 869 /* 870 * (intermediate)[in] 871 * / \ 872 * (new leaf node)[ln] (old node)[fn] 873 */ 874 if (plen > bit) { 875 in = node_alloc(net); 876 ln = node_alloc(net); 877 878 if (!in || !ln) { 879 if (in) 880 node_free_immediate(net, in); 881 if (ln) 882 node_free_immediate(net, ln); 883 return ERR_PTR(-ENOMEM); 884 } 885 886 /* 887 * new intermediate node. 888 * RTN_RTINFO will 889 * be off since that an address that chooses one of 890 * the branches would not match less specific routes 891 * in the other branch 892 */ 893 894 in->fn_bit = bit; 895 896 RCU_INIT_POINTER(in->parent, pn); 897 in->leaf = fn->leaf; 898 fib6_info_hold(rcu_dereference_protected(in->leaf, 899 lockdep_is_held(&table->tb6_lock))); 900 901 /* update parent pointer */ 902 if (dir) 903 rcu_assign_pointer(pn->right, in); 904 else 905 rcu_assign_pointer(pn->left, in); 906 907 ln->fn_bit = plen; 908 909 RCU_INIT_POINTER(ln->parent, in); 910 rcu_assign_pointer(fn->parent, in); 911 912 if (addr_bit_set(addr, bit)) { 913 rcu_assign_pointer(in->right, ln); 914 rcu_assign_pointer(in->left, fn); 915 } else { 916 rcu_assign_pointer(in->left, ln); 917 rcu_assign_pointer(in->right, fn); 918 } 919 } else { /* plen <= bit */ 920 921 /* 922 * (new leaf node)[ln] 923 * / \ 924 * (old node)[fn] NULL 925 */ 926 927 ln = node_alloc(net); 928 929 if (!ln) 930 return ERR_PTR(-ENOMEM); 931 932 ln->fn_bit = plen; 933 934 RCU_INIT_POINTER(ln->parent, pn); 935 936 if (addr_bit_set(&key->addr, plen)) 937 RCU_INIT_POINTER(ln->right, fn); 938 else 939 RCU_INIT_POINTER(ln->left, fn); 940 941 rcu_assign_pointer(fn->parent, ln); 942 943 if (dir) 944 rcu_assign_pointer(pn->right, ln); 945 else 946 rcu_assign_pointer(pn->left, ln); 947 } 948 return ln; 949 } 950 951 static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh, 952 const struct fib6_info *match, 953 const struct fib6_table *table) 954 { 955 int cpu; 956 957 if (!fib6_nh->rt6i_pcpu) 958 return; 959 960 /* release the reference to this fib entry from 961 * all of its cached pcpu routes 962 */ 963 for_each_possible_cpu(cpu) { 964 struct rt6_info **ppcpu_rt; 965 struct rt6_info *pcpu_rt; 966 967 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); 968 pcpu_rt = *ppcpu_rt; 969 970 /* only dropping the 'from' reference if the cached route 971 * is using 'match'. The cached pcpu_rt->from only changes 972 * from a fib6_info to NULL (ip6_dst_destroy); it can never 973 * change from one fib6_info reference to another 974 */ 975 if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) { 976 struct fib6_info *from; 977 978 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 979 fib6_info_release(from); 980 } 981 } 982 } 983 984 struct fib6_nh_pcpu_arg { 985 struct fib6_info *from; 986 const struct fib6_table *table; 987 }; 988 989 static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg) 990 { 991 struct fib6_nh_pcpu_arg *arg = _arg; 992 993 __fib6_drop_pcpu_from(nh, arg->from, arg->table); 994 return 0; 995 } 996 997 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 998 const struct fib6_table *table) 999 { 1000 /* Make sure rt6_make_pcpu_route() wont add other percpu routes 1001 * while we are cleaning them here. 1002 */ 1003 f6i->fib6_destroying = 1; 1004 mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */ 1005 1006 if (f6i->nh) { 1007 struct fib6_nh_pcpu_arg arg = { 1008 .from = f6i, 1009 .table = table 1010 }; 1011 1012 nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from, 1013 &arg); 1014 } else { 1015 struct fib6_nh *fib6_nh; 1016 1017 fib6_nh = f6i->fib6_nh; 1018 __fib6_drop_pcpu_from(fib6_nh, f6i, table); 1019 } 1020 } 1021 1022 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 1023 struct net *net) 1024 { 1025 struct fib6_table *table = rt->fib6_table; 1026 1027 fib6_drop_pcpu_from(rt, table); 1028 1029 if (rt->nh && !list_empty(&rt->nh_list)) 1030 list_del_init(&rt->nh_list); 1031 1032 if (refcount_read(&rt->fib6_ref) != 1) { 1033 /* This route is used as dummy address holder in some split 1034 * nodes. It is not leaked, but it still holds other resources, 1035 * which must be released in time. So, scan ascendant nodes 1036 * and replace dummy references to this route with references 1037 * to still alive ones. 1038 */ 1039 while (fn) { 1040 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 1041 lockdep_is_held(&table->tb6_lock)); 1042 struct fib6_info *new_leaf; 1043 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 1044 new_leaf = fib6_find_prefix(net, table, fn); 1045 fib6_info_hold(new_leaf); 1046 1047 rcu_assign_pointer(fn->leaf, new_leaf); 1048 fib6_info_release(rt); 1049 } 1050 fn = rcu_dereference_protected(fn->parent, 1051 lockdep_is_held(&table->tb6_lock)); 1052 } 1053 } 1054 } 1055 1056 /* 1057 * Insert routing information in a node. 1058 */ 1059 1060 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 1061 struct nl_info *info, 1062 struct netlink_ext_ack *extack) 1063 { 1064 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 1065 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1066 struct fib6_info *iter = NULL; 1067 struct fib6_info __rcu **ins; 1068 struct fib6_info __rcu **fallback_ins = NULL; 1069 int replace = (info->nlh && 1070 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 1071 int add = (!info->nlh || 1072 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 1073 int found = 0; 1074 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 1075 bool notify_sibling_rt = false; 1076 u16 nlflags = NLM_F_EXCL; 1077 int err; 1078 1079 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 1080 nlflags |= NLM_F_APPEND; 1081 1082 ins = &fn->leaf; 1083 1084 for (iter = leaf; iter; 1085 iter = rcu_dereference_protected(iter->fib6_next, 1086 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 1087 /* 1088 * Search for duplicates 1089 */ 1090 1091 if (iter->fib6_metric == rt->fib6_metric) { 1092 /* 1093 * Same priority level 1094 */ 1095 if (info->nlh && 1096 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 1097 return -EEXIST; 1098 1099 nlflags &= ~NLM_F_EXCL; 1100 if (replace) { 1101 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 1102 found++; 1103 break; 1104 } 1105 if (rt_can_ecmp) 1106 fallback_ins = fallback_ins ?: ins; 1107 goto next_iter; 1108 } 1109 1110 if (rt6_duplicate_nexthop(iter, rt)) { 1111 if (rt->fib6_nsiblings) 1112 rt->fib6_nsiblings = 0; 1113 if (!(iter->fib6_flags & RTF_EXPIRES)) 1114 return -EEXIST; 1115 if (!(rt->fib6_flags & RTF_EXPIRES)) 1116 fib6_clean_expires(iter); 1117 else 1118 fib6_set_expires(iter, rt->expires); 1119 1120 if (rt->fib6_pmtu) 1121 fib6_metric_set(iter, RTAX_MTU, 1122 rt->fib6_pmtu); 1123 return -EEXIST; 1124 } 1125 /* If we have the same destination and the same metric, 1126 * but not the same gateway, then the route we try to 1127 * add is sibling to this route, increment our counter 1128 * of siblings, and later we will add our route to the 1129 * list. 1130 * Only static routes (which don't have flag 1131 * RTF_EXPIRES) are used for ECMPv6. 1132 * 1133 * To avoid long list, we only had siblings if the 1134 * route have a gateway. 1135 */ 1136 if (rt_can_ecmp && 1137 rt6_qualify_for_ecmp(iter)) 1138 rt->fib6_nsiblings++; 1139 } 1140 1141 if (iter->fib6_metric > rt->fib6_metric) 1142 break; 1143 1144 next_iter: 1145 ins = &iter->fib6_next; 1146 } 1147 1148 if (fallback_ins && !found) { 1149 /* No ECMP-able route found, replace first non-ECMP one */ 1150 ins = fallback_ins; 1151 iter = rcu_dereference_protected(*ins, 1152 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1153 found++; 1154 } 1155 1156 /* Reset round-robin state, if necessary */ 1157 if (ins == &fn->leaf) 1158 fn->rr_ptr = NULL; 1159 1160 /* Link this route to others same route. */ 1161 if (rt->fib6_nsiblings) { 1162 unsigned int fib6_nsiblings; 1163 struct fib6_info *sibling, *temp_sibling; 1164 1165 /* Find the first route that have the same metric */ 1166 sibling = leaf; 1167 notify_sibling_rt = true; 1168 while (sibling) { 1169 if (sibling->fib6_metric == rt->fib6_metric && 1170 rt6_qualify_for_ecmp(sibling)) { 1171 list_add_tail(&rt->fib6_siblings, 1172 &sibling->fib6_siblings); 1173 break; 1174 } 1175 sibling = rcu_dereference_protected(sibling->fib6_next, 1176 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1177 notify_sibling_rt = false; 1178 } 1179 /* For each sibling in the list, increment the counter of 1180 * siblings. BUG() if counters does not match, list of siblings 1181 * is broken! 1182 */ 1183 fib6_nsiblings = 0; 1184 list_for_each_entry_safe(sibling, temp_sibling, 1185 &rt->fib6_siblings, fib6_siblings) { 1186 sibling->fib6_nsiblings++; 1187 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1188 fib6_nsiblings++; 1189 } 1190 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1191 rt6_multipath_rebalance(temp_sibling); 1192 } 1193 1194 /* 1195 * insert node 1196 */ 1197 if (!replace) { 1198 if (!add) 1199 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1200 1201 add: 1202 nlflags |= NLM_F_CREATE; 1203 1204 /* The route should only be notified if it is the first 1205 * route in the node or if it is added as a sibling 1206 * route to the first route in the node. 1207 */ 1208 if (!info->skip_notify_kernel && 1209 (notify_sibling_rt || ins == &fn->leaf)) { 1210 enum fib_event_type fib_event; 1211 1212 if (notify_sibling_rt) 1213 fib_event = FIB_EVENT_ENTRY_APPEND; 1214 else 1215 fib_event = FIB_EVENT_ENTRY_REPLACE; 1216 err = call_fib6_entry_notifiers(info->nl_net, 1217 fib_event, rt, 1218 extack); 1219 if (err) { 1220 struct fib6_info *sibling, *next_sibling; 1221 1222 /* If the route has siblings, then it first 1223 * needs to be unlinked from them. 1224 */ 1225 if (!rt->fib6_nsiblings) 1226 return err; 1227 1228 list_for_each_entry_safe(sibling, next_sibling, 1229 &rt->fib6_siblings, 1230 fib6_siblings) 1231 sibling->fib6_nsiblings--; 1232 rt->fib6_nsiblings = 0; 1233 list_del_init(&rt->fib6_siblings); 1234 rt6_multipath_rebalance(next_sibling); 1235 return err; 1236 } 1237 } 1238 1239 rcu_assign_pointer(rt->fib6_next, iter); 1240 fib6_info_hold(rt); 1241 rcu_assign_pointer(rt->fib6_node, fn); 1242 rcu_assign_pointer(*ins, rt); 1243 if (!info->skip_notify) 1244 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1245 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1246 1247 if (!(fn->fn_flags & RTN_RTINFO)) { 1248 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1249 fn->fn_flags |= RTN_RTINFO; 1250 } 1251 1252 } else { 1253 int nsiblings; 1254 1255 if (!found) { 1256 if (add) 1257 goto add; 1258 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1259 return -ENOENT; 1260 } 1261 1262 if (!info->skip_notify_kernel && ins == &fn->leaf) { 1263 err = call_fib6_entry_notifiers(info->nl_net, 1264 FIB_EVENT_ENTRY_REPLACE, 1265 rt, extack); 1266 if (err) 1267 return err; 1268 } 1269 1270 fib6_info_hold(rt); 1271 rcu_assign_pointer(rt->fib6_node, fn); 1272 rt->fib6_next = iter->fib6_next; 1273 rcu_assign_pointer(*ins, rt); 1274 if (!info->skip_notify) 1275 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1276 if (!(fn->fn_flags & RTN_RTINFO)) { 1277 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1278 fn->fn_flags |= RTN_RTINFO; 1279 } 1280 nsiblings = iter->fib6_nsiblings; 1281 iter->fib6_node = NULL; 1282 fib6_purge_rt(iter, fn, info->nl_net); 1283 if (rcu_access_pointer(fn->rr_ptr) == iter) 1284 fn->rr_ptr = NULL; 1285 fib6_info_release(iter); 1286 1287 if (nsiblings) { 1288 /* Replacing an ECMP route, remove all siblings */ 1289 ins = &rt->fib6_next; 1290 iter = rcu_dereference_protected(*ins, 1291 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1292 while (iter) { 1293 if (iter->fib6_metric > rt->fib6_metric) 1294 break; 1295 if (rt6_qualify_for_ecmp(iter)) { 1296 *ins = iter->fib6_next; 1297 iter->fib6_node = NULL; 1298 fib6_purge_rt(iter, fn, info->nl_net); 1299 if (rcu_access_pointer(fn->rr_ptr) == iter) 1300 fn->rr_ptr = NULL; 1301 fib6_info_release(iter); 1302 nsiblings--; 1303 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1304 } else { 1305 ins = &iter->fib6_next; 1306 } 1307 iter = rcu_dereference_protected(*ins, 1308 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1309 } 1310 WARN_ON(nsiblings != 0); 1311 } 1312 } 1313 1314 return 0; 1315 } 1316 1317 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1318 { 1319 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1320 (rt->fib6_flags & RTF_EXPIRES)) 1321 mod_timer(&net->ipv6.ip6_fib_timer, 1322 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1323 } 1324 1325 void fib6_force_start_gc(struct net *net) 1326 { 1327 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1328 mod_timer(&net->ipv6.ip6_fib_timer, 1329 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1330 } 1331 1332 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1333 int sernum) 1334 { 1335 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1336 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1337 1338 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1339 smp_wmb(); 1340 while (fn) { 1341 fn->fn_sernum = sernum; 1342 fn = rcu_dereference_protected(fn->parent, 1343 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1344 } 1345 } 1346 1347 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1348 { 1349 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1350 } 1351 1352 /* allow ipv4 to update sernum via ipv6_stub */ 1353 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i) 1354 { 1355 spin_lock_bh(&f6i->fib6_table->tb6_lock); 1356 fib6_update_sernum_upto_root(net, f6i); 1357 spin_unlock_bh(&f6i->fib6_table->tb6_lock); 1358 } 1359 1360 /* 1361 * Add routing information to the routing tree. 1362 * <destination addr>/<source addr> 1363 * with source addr info in sub-trees 1364 * Need to own table->tb6_lock 1365 */ 1366 1367 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1368 struct nl_info *info, struct netlink_ext_ack *extack) 1369 { 1370 struct fib6_table *table = rt->fib6_table; 1371 struct fib6_node *fn, *pn = NULL; 1372 int err = -ENOMEM; 1373 int allow_create = 1; 1374 int replace_required = 0; 1375 int sernum = fib6_new_sernum(info->nl_net); 1376 1377 if (info->nlh) { 1378 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1379 allow_create = 0; 1380 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1381 replace_required = 1; 1382 } 1383 if (!allow_create && !replace_required) 1384 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1385 1386 fn = fib6_add_1(info->nl_net, table, root, 1387 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1388 offsetof(struct fib6_info, fib6_dst), allow_create, 1389 replace_required, extack); 1390 if (IS_ERR(fn)) { 1391 err = PTR_ERR(fn); 1392 fn = NULL; 1393 goto out; 1394 } 1395 1396 pn = fn; 1397 1398 #ifdef CONFIG_IPV6_SUBTREES 1399 if (rt->fib6_src.plen) { 1400 struct fib6_node *sn; 1401 1402 if (!rcu_access_pointer(fn->subtree)) { 1403 struct fib6_node *sfn; 1404 1405 /* 1406 * Create subtree. 1407 * 1408 * fn[main tree] 1409 * | 1410 * sfn[subtree root] 1411 * \ 1412 * sn[new leaf node] 1413 */ 1414 1415 /* Create subtree root node */ 1416 sfn = node_alloc(info->nl_net); 1417 if (!sfn) 1418 goto failure; 1419 1420 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry); 1421 rcu_assign_pointer(sfn->leaf, 1422 info->nl_net->ipv6.fib6_null_entry); 1423 sfn->fn_flags = RTN_ROOT; 1424 1425 /* Now add the first leaf node to new subtree */ 1426 1427 sn = fib6_add_1(info->nl_net, table, sfn, 1428 &rt->fib6_src.addr, rt->fib6_src.plen, 1429 offsetof(struct fib6_info, fib6_src), 1430 allow_create, replace_required, extack); 1431 1432 if (IS_ERR(sn)) { 1433 /* If it is failed, discard just allocated 1434 root, and then (in failure) stale node 1435 in main tree. 1436 */ 1437 node_free_immediate(info->nl_net, sfn); 1438 err = PTR_ERR(sn); 1439 goto failure; 1440 } 1441 1442 /* Now link new subtree to main tree */ 1443 rcu_assign_pointer(sfn->parent, fn); 1444 rcu_assign_pointer(fn->subtree, sfn); 1445 } else { 1446 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1447 &rt->fib6_src.addr, rt->fib6_src.plen, 1448 offsetof(struct fib6_info, fib6_src), 1449 allow_create, replace_required, extack); 1450 1451 if (IS_ERR(sn)) { 1452 err = PTR_ERR(sn); 1453 goto failure; 1454 } 1455 } 1456 1457 if (!rcu_access_pointer(fn->leaf)) { 1458 if (fn->fn_flags & RTN_TL_ROOT) { 1459 /* put back null_entry for root node */ 1460 rcu_assign_pointer(fn->leaf, 1461 info->nl_net->ipv6.fib6_null_entry); 1462 } else { 1463 fib6_info_hold(rt); 1464 rcu_assign_pointer(fn->leaf, rt); 1465 } 1466 } 1467 fn = sn; 1468 } 1469 #endif 1470 1471 err = fib6_add_rt2node(fn, rt, info, extack); 1472 if (!err) { 1473 if (rt->nh) 1474 list_add(&rt->nh_list, &rt->nh->f6i_list); 1475 __fib6_update_sernum_upto_root(rt, sernum); 1476 fib6_start_gc(info->nl_net, rt); 1477 } 1478 1479 out: 1480 if (err) { 1481 #ifdef CONFIG_IPV6_SUBTREES 1482 /* 1483 * If fib6_add_1 has cleared the old leaf pointer in the 1484 * super-tree leaf node we have to find a new one for it. 1485 */ 1486 if (pn != fn) { 1487 struct fib6_info *pn_leaf = 1488 rcu_dereference_protected(pn->leaf, 1489 lockdep_is_held(&table->tb6_lock)); 1490 if (pn_leaf == rt) { 1491 pn_leaf = NULL; 1492 RCU_INIT_POINTER(pn->leaf, NULL); 1493 fib6_info_release(rt); 1494 } 1495 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1496 pn_leaf = fib6_find_prefix(info->nl_net, table, 1497 pn); 1498 #if RT6_DEBUG >= 2 1499 if (!pn_leaf) { 1500 WARN_ON(!pn_leaf); 1501 pn_leaf = 1502 info->nl_net->ipv6.fib6_null_entry; 1503 } 1504 #endif 1505 fib6_info_hold(pn_leaf); 1506 rcu_assign_pointer(pn->leaf, pn_leaf); 1507 } 1508 } 1509 #endif 1510 goto failure; 1511 } else if (fib6_requires_src(rt)) { 1512 fib6_routes_require_src_inc(info->nl_net); 1513 } 1514 return err; 1515 1516 failure: 1517 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1518 * 1. fn is an intermediate node and we failed to add the new 1519 * route to it in both subtree creation failure and fib6_add_rt2node() 1520 * failure case. 1521 * 2. fn is the root node in the table and we fail to add the first 1522 * default route to it. 1523 */ 1524 if (fn && 1525 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1526 (fn->fn_flags & RTN_TL_ROOT && 1527 !rcu_access_pointer(fn->leaf)))) 1528 fib6_repair_tree(info->nl_net, table, fn); 1529 return err; 1530 } 1531 1532 /* 1533 * Routing tree lookup 1534 * 1535 */ 1536 1537 struct lookup_args { 1538 int offset; /* key offset on fib6_info */ 1539 const struct in6_addr *addr; /* search key */ 1540 }; 1541 1542 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1543 struct lookup_args *args) 1544 { 1545 struct fib6_node *fn; 1546 __be32 dir; 1547 1548 if (unlikely(args->offset == 0)) 1549 return NULL; 1550 1551 /* 1552 * Descend on a tree 1553 */ 1554 1555 fn = root; 1556 1557 for (;;) { 1558 struct fib6_node *next; 1559 1560 dir = addr_bit_set(args->addr, fn->fn_bit); 1561 1562 next = dir ? rcu_dereference(fn->right) : 1563 rcu_dereference(fn->left); 1564 1565 if (next) { 1566 fn = next; 1567 continue; 1568 } 1569 break; 1570 } 1571 1572 while (fn) { 1573 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1574 1575 if (subtree || fn->fn_flags & RTN_RTINFO) { 1576 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1577 struct rt6key *key; 1578 1579 if (!leaf) 1580 goto backtrack; 1581 1582 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1583 1584 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1585 #ifdef CONFIG_IPV6_SUBTREES 1586 if (subtree) { 1587 struct fib6_node *sfn; 1588 sfn = fib6_node_lookup_1(subtree, 1589 args + 1); 1590 if (!sfn) 1591 goto backtrack; 1592 fn = sfn; 1593 } 1594 #endif 1595 if (fn->fn_flags & RTN_RTINFO) 1596 return fn; 1597 } 1598 } 1599 backtrack: 1600 if (fn->fn_flags & RTN_ROOT) 1601 break; 1602 1603 fn = rcu_dereference(fn->parent); 1604 } 1605 1606 return NULL; 1607 } 1608 1609 /* called with rcu_read_lock() held 1610 */ 1611 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1612 const struct in6_addr *daddr, 1613 const struct in6_addr *saddr) 1614 { 1615 struct fib6_node *fn; 1616 struct lookup_args args[] = { 1617 { 1618 .offset = offsetof(struct fib6_info, fib6_dst), 1619 .addr = daddr, 1620 }, 1621 #ifdef CONFIG_IPV6_SUBTREES 1622 { 1623 .offset = offsetof(struct fib6_info, fib6_src), 1624 .addr = saddr, 1625 }, 1626 #endif 1627 { 1628 .offset = 0, /* sentinel */ 1629 } 1630 }; 1631 1632 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1633 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1634 fn = root; 1635 1636 return fn; 1637 } 1638 1639 /* 1640 * Get node with specified destination prefix (and source prefix, 1641 * if subtrees are used) 1642 * exact_match == true means we try to find fn with exact match of 1643 * the passed in prefix addr 1644 * exact_match == false means we try to find fn with longest prefix 1645 * match of the passed in prefix addr. This is useful for finding fn 1646 * for cached route as it will be stored in the exception table under 1647 * the node with longest prefix length. 1648 */ 1649 1650 1651 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1652 const struct in6_addr *addr, 1653 int plen, int offset, 1654 bool exact_match) 1655 { 1656 struct fib6_node *fn, *prev = NULL; 1657 1658 for (fn = root; fn ; ) { 1659 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1660 struct rt6key *key; 1661 1662 /* This node is being deleted */ 1663 if (!leaf) { 1664 if (plen <= fn->fn_bit) 1665 goto out; 1666 else 1667 goto next; 1668 } 1669 1670 key = (struct rt6key *)((u8 *)leaf + offset); 1671 1672 /* 1673 * Prefix match 1674 */ 1675 if (plen < fn->fn_bit || 1676 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1677 goto out; 1678 1679 if (plen == fn->fn_bit) 1680 return fn; 1681 1682 if (fn->fn_flags & RTN_RTINFO) 1683 prev = fn; 1684 1685 next: 1686 /* 1687 * We have more bits to go 1688 */ 1689 if (addr_bit_set(addr, fn->fn_bit)) 1690 fn = rcu_dereference(fn->right); 1691 else 1692 fn = rcu_dereference(fn->left); 1693 } 1694 out: 1695 if (exact_match) 1696 return NULL; 1697 else 1698 return prev; 1699 } 1700 1701 struct fib6_node *fib6_locate(struct fib6_node *root, 1702 const struct in6_addr *daddr, int dst_len, 1703 const struct in6_addr *saddr, int src_len, 1704 bool exact_match) 1705 { 1706 struct fib6_node *fn; 1707 1708 fn = fib6_locate_1(root, daddr, dst_len, 1709 offsetof(struct fib6_info, fib6_dst), 1710 exact_match); 1711 1712 #ifdef CONFIG_IPV6_SUBTREES 1713 if (src_len) { 1714 WARN_ON(saddr == NULL); 1715 if (fn) { 1716 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1717 1718 if (subtree) { 1719 fn = fib6_locate_1(subtree, saddr, src_len, 1720 offsetof(struct fib6_info, fib6_src), 1721 exact_match); 1722 } 1723 } 1724 } 1725 #endif 1726 1727 if (fn && fn->fn_flags & RTN_RTINFO) 1728 return fn; 1729 1730 return NULL; 1731 } 1732 1733 1734 /* 1735 * Deletion 1736 * 1737 */ 1738 1739 static struct fib6_info *fib6_find_prefix(struct net *net, 1740 struct fib6_table *table, 1741 struct fib6_node *fn) 1742 { 1743 struct fib6_node *child_left, *child_right; 1744 1745 if (fn->fn_flags & RTN_ROOT) 1746 return net->ipv6.fib6_null_entry; 1747 1748 while (fn) { 1749 child_left = rcu_dereference_protected(fn->left, 1750 lockdep_is_held(&table->tb6_lock)); 1751 child_right = rcu_dereference_protected(fn->right, 1752 lockdep_is_held(&table->tb6_lock)); 1753 if (child_left) 1754 return rcu_dereference_protected(child_left->leaf, 1755 lockdep_is_held(&table->tb6_lock)); 1756 if (child_right) 1757 return rcu_dereference_protected(child_right->leaf, 1758 lockdep_is_held(&table->tb6_lock)); 1759 1760 fn = FIB6_SUBTREE(fn); 1761 } 1762 return NULL; 1763 } 1764 1765 /* 1766 * Called to trim the tree of intermediate nodes when possible. "fn" 1767 * is the node we want to try and remove. 1768 * Need to own table->tb6_lock 1769 */ 1770 1771 static struct fib6_node *fib6_repair_tree(struct net *net, 1772 struct fib6_table *table, 1773 struct fib6_node *fn) 1774 { 1775 int children; 1776 int nstate; 1777 struct fib6_node *child; 1778 struct fib6_walker *w; 1779 int iter = 0; 1780 1781 /* Set fn->leaf to null_entry for root node. */ 1782 if (fn->fn_flags & RTN_TL_ROOT) { 1783 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1784 return fn; 1785 } 1786 1787 for (;;) { 1788 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1789 lockdep_is_held(&table->tb6_lock)); 1790 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1791 lockdep_is_held(&table->tb6_lock)); 1792 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1793 lockdep_is_held(&table->tb6_lock)); 1794 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1795 lockdep_is_held(&table->tb6_lock)); 1796 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1797 lockdep_is_held(&table->tb6_lock)); 1798 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1799 lockdep_is_held(&table->tb6_lock)); 1800 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1801 lockdep_is_held(&table->tb6_lock)); 1802 struct fib6_info *new_fn_leaf; 1803 1804 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1805 iter++; 1806 1807 WARN_ON(fn->fn_flags & RTN_RTINFO); 1808 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1809 WARN_ON(fn_leaf); 1810 1811 children = 0; 1812 child = NULL; 1813 if (fn_r) 1814 child = fn_r, children |= 1; 1815 if (fn_l) 1816 child = fn_l, children |= 2; 1817 1818 if (children == 3 || FIB6_SUBTREE(fn) 1819 #ifdef CONFIG_IPV6_SUBTREES 1820 /* Subtree root (i.e. fn) may have one child */ 1821 || (children && fn->fn_flags & RTN_ROOT) 1822 #endif 1823 ) { 1824 new_fn_leaf = fib6_find_prefix(net, table, fn); 1825 #if RT6_DEBUG >= 2 1826 if (!new_fn_leaf) { 1827 WARN_ON(!new_fn_leaf); 1828 new_fn_leaf = net->ipv6.fib6_null_entry; 1829 } 1830 #endif 1831 fib6_info_hold(new_fn_leaf); 1832 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1833 return pn; 1834 } 1835 1836 #ifdef CONFIG_IPV6_SUBTREES 1837 if (FIB6_SUBTREE(pn) == fn) { 1838 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1839 RCU_INIT_POINTER(pn->subtree, NULL); 1840 nstate = FWS_L; 1841 } else { 1842 WARN_ON(fn->fn_flags & RTN_ROOT); 1843 #endif 1844 if (pn_r == fn) 1845 rcu_assign_pointer(pn->right, child); 1846 else if (pn_l == fn) 1847 rcu_assign_pointer(pn->left, child); 1848 #if RT6_DEBUG >= 2 1849 else 1850 WARN_ON(1); 1851 #endif 1852 if (child) 1853 rcu_assign_pointer(child->parent, pn); 1854 nstate = FWS_R; 1855 #ifdef CONFIG_IPV6_SUBTREES 1856 } 1857 #endif 1858 1859 read_lock(&net->ipv6.fib6_walker_lock); 1860 FOR_WALKERS(net, w) { 1861 if (!child) { 1862 if (w->node == fn) { 1863 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1864 w->node = pn; 1865 w->state = nstate; 1866 } 1867 } else { 1868 if (w->node == fn) { 1869 w->node = child; 1870 if (children&2) { 1871 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1872 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1873 } else { 1874 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1875 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1876 } 1877 } 1878 } 1879 } 1880 read_unlock(&net->ipv6.fib6_walker_lock); 1881 1882 node_free(net, fn); 1883 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1884 return pn; 1885 1886 RCU_INIT_POINTER(pn->leaf, NULL); 1887 fib6_info_release(pn_leaf); 1888 fn = pn; 1889 } 1890 } 1891 1892 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1893 struct fib6_info __rcu **rtp, struct nl_info *info) 1894 { 1895 struct fib6_info *leaf, *replace_rt = NULL; 1896 struct fib6_walker *w; 1897 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1898 lockdep_is_held(&table->tb6_lock)); 1899 struct net *net = info->nl_net; 1900 bool notify_del = false; 1901 1902 RT6_TRACE("fib6_del_route\n"); 1903 1904 /* If the deleted route is the first in the node and it is not part of 1905 * a multipath route, then we need to replace it with the next route 1906 * in the node, if exists. 1907 */ 1908 leaf = rcu_dereference_protected(fn->leaf, 1909 lockdep_is_held(&table->tb6_lock)); 1910 if (leaf == rt && !rt->fib6_nsiblings) { 1911 if (rcu_access_pointer(rt->fib6_next)) 1912 replace_rt = rcu_dereference_protected(rt->fib6_next, 1913 lockdep_is_held(&table->tb6_lock)); 1914 else 1915 notify_del = true; 1916 } 1917 1918 /* Unlink it */ 1919 *rtp = rt->fib6_next; 1920 rt->fib6_node = NULL; 1921 net->ipv6.rt6_stats->fib_rt_entries--; 1922 net->ipv6.rt6_stats->fib_discarded_routes++; 1923 1924 /* Flush all cached dst in exception table */ 1925 rt6_flush_exceptions(rt); 1926 1927 /* Reset round-robin state, if necessary */ 1928 if (rcu_access_pointer(fn->rr_ptr) == rt) 1929 fn->rr_ptr = NULL; 1930 1931 /* Remove this entry from other siblings */ 1932 if (rt->fib6_nsiblings) { 1933 struct fib6_info *sibling, *next_sibling; 1934 1935 /* The route is deleted from a multipath route. If this 1936 * multipath route is the first route in the node, then we need 1937 * to emit a delete notification. Otherwise, we need to skip 1938 * the notification. 1939 */ 1940 if (rt->fib6_metric == leaf->fib6_metric && 1941 rt6_qualify_for_ecmp(leaf)) 1942 notify_del = true; 1943 list_for_each_entry_safe(sibling, next_sibling, 1944 &rt->fib6_siblings, fib6_siblings) 1945 sibling->fib6_nsiblings--; 1946 rt->fib6_nsiblings = 0; 1947 list_del_init(&rt->fib6_siblings); 1948 rt6_multipath_rebalance(next_sibling); 1949 } 1950 1951 /* Adjust walkers */ 1952 read_lock(&net->ipv6.fib6_walker_lock); 1953 FOR_WALKERS(net, w) { 1954 if (w->state == FWS_C && w->leaf == rt) { 1955 RT6_TRACE("walker %p adjusted by delroute\n", w); 1956 w->leaf = rcu_dereference_protected(rt->fib6_next, 1957 lockdep_is_held(&table->tb6_lock)); 1958 if (!w->leaf) 1959 w->state = FWS_U; 1960 } 1961 } 1962 read_unlock(&net->ipv6.fib6_walker_lock); 1963 1964 /* If it was last route, call fib6_repair_tree() to: 1965 * 1. For root node, put back null_entry as how the table was created. 1966 * 2. For other nodes, expunge its radix tree node. 1967 */ 1968 if (!rcu_access_pointer(fn->leaf)) { 1969 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1970 fn->fn_flags &= ~RTN_RTINFO; 1971 net->ipv6.rt6_stats->fib_route_nodes--; 1972 } 1973 fn = fib6_repair_tree(net, table, fn); 1974 } 1975 1976 fib6_purge_rt(rt, fn, net); 1977 1978 if (!info->skip_notify_kernel) { 1979 if (notify_del) 1980 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, 1981 rt, NULL); 1982 else if (replace_rt) 1983 call_fib6_entry_notifiers_replace(net, replace_rt); 1984 } 1985 if (!info->skip_notify) 1986 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1987 1988 fib6_info_release(rt); 1989 } 1990 1991 /* Need to own table->tb6_lock */ 1992 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1993 { 1994 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1995 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1996 struct fib6_table *table = rt->fib6_table; 1997 struct net *net = info->nl_net; 1998 struct fib6_info __rcu **rtp; 1999 struct fib6_info __rcu **rtp_next; 2000 2001 if (!fn || rt == net->ipv6.fib6_null_entry) 2002 return -ENOENT; 2003 2004 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 2005 2006 /* 2007 * Walk the leaf entries looking for ourself 2008 */ 2009 2010 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 2011 struct fib6_info *cur = rcu_dereference_protected(*rtp, 2012 lockdep_is_held(&table->tb6_lock)); 2013 if (rt == cur) { 2014 if (fib6_requires_src(cur)) 2015 fib6_routes_require_src_dec(info->nl_net); 2016 fib6_del_route(table, fn, rtp, info); 2017 return 0; 2018 } 2019 rtp_next = &cur->fib6_next; 2020 } 2021 return -ENOENT; 2022 } 2023 2024 /* 2025 * Tree traversal function. 2026 * 2027 * Certainly, it is not interrupt safe. 2028 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 2029 * It means, that we can modify tree during walking 2030 * and use this function for garbage collection, clone pruning, 2031 * cleaning tree when a device goes down etc. etc. 2032 * 2033 * It guarantees that every node will be traversed, 2034 * and that it will be traversed only once. 2035 * 2036 * Callback function w->func may return: 2037 * 0 -> continue walking. 2038 * positive value -> walking is suspended (used by tree dumps, 2039 * and probably by gc, if it will be split to several slices) 2040 * negative value -> terminate walking. 2041 * 2042 * The function itself returns: 2043 * 0 -> walk is complete. 2044 * >0 -> walk is incomplete (i.e. suspended) 2045 * <0 -> walk is terminated by an error. 2046 * 2047 * This function is called with tb6_lock held. 2048 */ 2049 2050 static int fib6_walk_continue(struct fib6_walker *w) 2051 { 2052 struct fib6_node *fn, *pn, *left, *right; 2053 2054 /* w->root should always be table->tb6_root */ 2055 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 2056 2057 for (;;) { 2058 fn = w->node; 2059 if (!fn) 2060 return 0; 2061 2062 switch (w->state) { 2063 #ifdef CONFIG_IPV6_SUBTREES 2064 case FWS_S: 2065 if (FIB6_SUBTREE(fn)) { 2066 w->node = FIB6_SUBTREE(fn); 2067 continue; 2068 } 2069 w->state = FWS_L; 2070 #endif 2071 /* fall through */ 2072 case FWS_L: 2073 left = rcu_dereference_protected(fn->left, 1); 2074 if (left) { 2075 w->node = left; 2076 w->state = FWS_INIT; 2077 continue; 2078 } 2079 w->state = FWS_R; 2080 /* fall through */ 2081 case FWS_R: 2082 right = rcu_dereference_protected(fn->right, 1); 2083 if (right) { 2084 w->node = right; 2085 w->state = FWS_INIT; 2086 continue; 2087 } 2088 w->state = FWS_C; 2089 w->leaf = rcu_dereference_protected(fn->leaf, 1); 2090 /* fall through */ 2091 case FWS_C: 2092 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 2093 int err; 2094 2095 if (w->skip) { 2096 w->skip--; 2097 goto skip; 2098 } 2099 2100 err = w->func(w); 2101 if (err) 2102 return err; 2103 2104 w->count++; 2105 continue; 2106 } 2107 skip: 2108 w->state = FWS_U; 2109 /* fall through */ 2110 case FWS_U: 2111 if (fn == w->root) 2112 return 0; 2113 pn = rcu_dereference_protected(fn->parent, 1); 2114 left = rcu_dereference_protected(pn->left, 1); 2115 right = rcu_dereference_protected(pn->right, 1); 2116 w->node = pn; 2117 #ifdef CONFIG_IPV6_SUBTREES 2118 if (FIB6_SUBTREE(pn) == fn) { 2119 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 2120 w->state = FWS_L; 2121 continue; 2122 } 2123 #endif 2124 if (left == fn) { 2125 w->state = FWS_R; 2126 continue; 2127 } 2128 if (right == fn) { 2129 w->state = FWS_C; 2130 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 2131 continue; 2132 } 2133 #if RT6_DEBUG >= 2 2134 WARN_ON(1); 2135 #endif 2136 } 2137 } 2138 } 2139 2140 static int fib6_walk(struct net *net, struct fib6_walker *w) 2141 { 2142 int res; 2143 2144 w->state = FWS_INIT; 2145 w->node = w->root; 2146 2147 fib6_walker_link(net, w); 2148 res = fib6_walk_continue(w); 2149 if (res <= 0) 2150 fib6_walker_unlink(net, w); 2151 return res; 2152 } 2153 2154 static int fib6_clean_node(struct fib6_walker *w) 2155 { 2156 int res; 2157 struct fib6_info *rt; 2158 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 2159 struct nl_info info = { 2160 .nl_net = c->net, 2161 .skip_notify = c->skip_notify, 2162 }; 2163 2164 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 2165 w->node->fn_sernum != c->sernum) 2166 w->node->fn_sernum = c->sernum; 2167 2168 if (!c->func) { 2169 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 2170 w->leaf = NULL; 2171 return 0; 2172 } 2173 2174 for_each_fib6_walker_rt(w) { 2175 res = c->func(rt, c->arg); 2176 if (res == -1) { 2177 w->leaf = rt; 2178 res = fib6_del(rt, &info); 2179 if (res) { 2180 #if RT6_DEBUG >= 2 2181 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 2182 __func__, rt, 2183 rcu_access_pointer(rt->fib6_node), 2184 res); 2185 #endif 2186 continue; 2187 } 2188 return 0; 2189 } else if (res == -2) { 2190 if (WARN_ON(!rt->fib6_nsiblings)) 2191 continue; 2192 rt = list_last_entry(&rt->fib6_siblings, 2193 struct fib6_info, fib6_siblings); 2194 continue; 2195 } 2196 WARN_ON(res != 0); 2197 } 2198 w->leaf = rt; 2199 return 0; 2200 } 2201 2202 /* 2203 * Convenient frontend to tree walker. 2204 * 2205 * func is called on each route. 2206 * It may return -2 -> skip multipath route. 2207 * -1 -> delete this route. 2208 * 0 -> continue walking 2209 */ 2210 2211 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2212 int (*func)(struct fib6_info *, void *arg), 2213 int sernum, void *arg, bool skip_notify) 2214 { 2215 struct fib6_cleaner c; 2216 2217 c.w.root = root; 2218 c.w.func = fib6_clean_node; 2219 c.w.count = 0; 2220 c.w.skip = 0; 2221 c.w.skip_in_node = 0; 2222 c.func = func; 2223 c.sernum = sernum; 2224 c.arg = arg; 2225 c.net = net; 2226 c.skip_notify = skip_notify; 2227 2228 fib6_walk(net, &c.w); 2229 } 2230 2231 static void __fib6_clean_all(struct net *net, 2232 int (*func)(struct fib6_info *, void *), 2233 int sernum, void *arg, bool skip_notify) 2234 { 2235 struct fib6_table *table; 2236 struct hlist_head *head; 2237 unsigned int h; 2238 2239 rcu_read_lock(); 2240 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2241 head = &net->ipv6.fib_table_hash[h]; 2242 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2243 spin_lock_bh(&table->tb6_lock); 2244 fib6_clean_tree(net, &table->tb6_root, 2245 func, sernum, arg, skip_notify); 2246 spin_unlock_bh(&table->tb6_lock); 2247 } 2248 } 2249 rcu_read_unlock(); 2250 } 2251 2252 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2253 void *arg) 2254 { 2255 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false); 2256 } 2257 2258 void fib6_clean_all_skip_notify(struct net *net, 2259 int (*func)(struct fib6_info *, void *), 2260 void *arg) 2261 { 2262 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true); 2263 } 2264 2265 static void fib6_flush_trees(struct net *net) 2266 { 2267 int new_sernum = fib6_new_sernum(net); 2268 2269 __fib6_clean_all(net, NULL, new_sernum, NULL, false); 2270 } 2271 2272 /* 2273 * Garbage collection 2274 */ 2275 2276 static int fib6_age(struct fib6_info *rt, void *arg) 2277 { 2278 struct fib6_gc_args *gc_args = arg; 2279 unsigned long now = jiffies; 2280 2281 /* 2282 * check addrconf expiration here. 2283 * Routes are expired even if they are in use. 2284 */ 2285 2286 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2287 if (time_after(now, rt->expires)) { 2288 RT6_TRACE("expiring %p\n", rt); 2289 return -1; 2290 } 2291 gc_args->more++; 2292 } 2293 2294 /* Also age clones in the exception table. 2295 * Note, that clones are aged out 2296 * only if they are not in use now. 2297 */ 2298 rt6_age_exceptions(rt, gc_args, now); 2299 2300 return 0; 2301 } 2302 2303 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2304 { 2305 struct fib6_gc_args gc_args; 2306 unsigned long now; 2307 2308 if (force) { 2309 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2310 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2311 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2312 return; 2313 } 2314 gc_args.timeout = expires ? (int)expires : 2315 net->ipv6.sysctl.ip6_rt_gc_interval; 2316 gc_args.more = 0; 2317 2318 fib6_clean_all(net, fib6_age, &gc_args); 2319 now = jiffies; 2320 net->ipv6.ip6_rt_last_gc = now; 2321 2322 if (gc_args.more) 2323 mod_timer(&net->ipv6.ip6_fib_timer, 2324 round_jiffies(now 2325 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2326 else 2327 del_timer(&net->ipv6.ip6_fib_timer); 2328 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2329 } 2330 2331 static void fib6_gc_timer_cb(struct timer_list *t) 2332 { 2333 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2334 2335 fib6_run_gc(0, arg, true); 2336 } 2337 2338 static int __net_init fib6_net_init(struct net *net) 2339 { 2340 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2341 int err; 2342 2343 err = fib6_notifier_init(net); 2344 if (err) 2345 return err; 2346 2347 spin_lock_init(&net->ipv6.fib6_gc_lock); 2348 rwlock_init(&net->ipv6.fib6_walker_lock); 2349 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2350 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2351 2352 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2353 if (!net->ipv6.rt6_stats) 2354 goto out_timer; 2355 2356 /* Avoid false sharing : Use at least a full cache line */ 2357 size = max_t(size_t, size, L1_CACHE_BYTES); 2358 2359 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2360 if (!net->ipv6.fib_table_hash) 2361 goto out_rt6_stats; 2362 2363 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2364 GFP_KERNEL); 2365 if (!net->ipv6.fib6_main_tbl) 2366 goto out_fib_table_hash; 2367 2368 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2369 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2370 net->ipv6.fib6_null_entry); 2371 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2372 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2373 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2374 2375 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2376 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2377 GFP_KERNEL); 2378 if (!net->ipv6.fib6_local_tbl) 2379 goto out_fib6_main_tbl; 2380 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2381 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2382 net->ipv6.fib6_null_entry); 2383 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2384 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2385 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2386 #endif 2387 fib6_tables_init(net); 2388 2389 return 0; 2390 2391 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2392 out_fib6_main_tbl: 2393 kfree(net->ipv6.fib6_main_tbl); 2394 #endif 2395 out_fib_table_hash: 2396 kfree(net->ipv6.fib_table_hash); 2397 out_rt6_stats: 2398 kfree(net->ipv6.rt6_stats); 2399 out_timer: 2400 fib6_notifier_exit(net); 2401 return -ENOMEM; 2402 } 2403 2404 static void fib6_net_exit(struct net *net) 2405 { 2406 unsigned int i; 2407 2408 del_timer_sync(&net->ipv6.ip6_fib_timer); 2409 2410 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2411 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2412 struct hlist_node *tmp; 2413 struct fib6_table *tb; 2414 2415 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2416 hlist_del(&tb->tb6_hlist); 2417 fib6_free_table(tb); 2418 } 2419 } 2420 2421 kfree(net->ipv6.fib_table_hash); 2422 kfree(net->ipv6.rt6_stats); 2423 fib6_notifier_exit(net); 2424 } 2425 2426 static struct pernet_operations fib6_net_ops = { 2427 .init = fib6_net_init, 2428 .exit = fib6_net_exit, 2429 }; 2430 2431 int __init fib6_init(void) 2432 { 2433 int ret = -ENOMEM; 2434 2435 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2436 sizeof(struct fib6_node), 2437 0, SLAB_HWCACHE_ALIGN, 2438 NULL); 2439 if (!fib6_node_kmem) 2440 goto out; 2441 2442 ret = register_pernet_subsys(&fib6_net_ops); 2443 if (ret) 2444 goto out_kmem_cache_create; 2445 2446 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2447 inet6_dump_fib, 0); 2448 if (ret) 2449 goto out_unregister_subsys; 2450 2451 __fib6_flush_trees = fib6_flush_trees; 2452 out: 2453 return ret; 2454 2455 out_unregister_subsys: 2456 unregister_pernet_subsys(&fib6_net_ops); 2457 out_kmem_cache_create: 2458 kmem_cache_destroy(fib6_node_kmem); 2459 goto out; 2460 } 2461 2462 void fib6_gc_cleanup(void) 2463 { 2464 unregister_pernet_subsys(&fib6_net_ops); 2465 kmem_cache_destroy(fib6_node_kmem); 2466 } 2467 2468 #ifdef CONFIG_PROC_FS 2469 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2470 { 2471 struct fib6_info *rt = v; 2472 struct ipv6_route_iter *iter = seq->private; 2473 struct fib6_nh *fib6_nh = rt->fib6_nh; 2474 unsigned int flags = rt->fib6_flags; 2475 const struct net_device *dev; 2476 2477 if (rt->nh) 2478 fib6_nh = nexthop_fib6_nh(rt->nh); 2479 2480 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2481 2482 #ifdef CONFIG_IPV6_SUBTREES 2483 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2484 #else 2485 seq_puts(seq, "00000000000000000000000000000000 00 "); 2486 #endif 2487 if (fib6_nh->fib_nh_gw_family) { 2488 flags |= RTF_GATEWAY; 2489 seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6); 2490 } else { 2491 seq_puts(seq, "00000000000000000000000000000000"); 2492 } 2493 2494 dev = fib6_nh->fib_nh_dev; 2495 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2496 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0, 2497 flags, dev ? dev->name : ""); 2498 iter->w.leaf = NULL; 2499 return 0; 2500 } 2501 2502 static int ipv6_route_yield(struct fib6_walker *w) 2503 { 2504 struct ipv6_route_iter *iter = w->args; 2505 2506 if (!iter->skip) 2507 return 1; 2508 2509 do { 2510 iter->w.leaf = rcu_dereference_protected( 2511 iter->w.leaf->fib6_next, 2512 lockdep_is_held(&iter->tbl->tb6_lock)); 2513 iter->skip--; 2514 if (!iter->skip && iter->w.leaf) 2515 return 1; 2516 } while (iter->w.leaf); 2517 2518 return 0; 2519 } 2520 2521 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2522 struct net *net) 2523 { 2524 memset(&iter->w, 0, sizeof(iter->w)); 2525 iter->w.func = ipv6_route_yield; 2526 iter->w.root = &iter->tbl->tb6_root; 2527 iter->w.state = FWS_INIT; 2528 iter->w.node = iter->w.root; 2529 iter->w.args = iter; 2530 iter->sernum = iter->w.root->fn_sernum; 2531 INIT_LIST_HEAD(&iter->w.lh); 2532 fib6_walker_link(net, &iter->w); 2533 } 2534 2535 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2536 struct net *net) 2537 { 2538 unsigned int h; 2539 struct hlist_node *node; 2540 2541 if (tbl) { 2542 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2543 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2544 } else { 2545 h = 0; 2546 node = NULL; 2547 } 2548 2549 while (!node && h < FIB6_TABLE_HASHSZ) { 2550 node = rcu_dereference_bh( 2551 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2552 } 2553 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2554 } 2555 2556 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2557 { 2558 if (iter->sernum != iter->w.root->fn_sernum) { 2559 iter->sernum = iter->w.root->fn_sernum; 2560 iter->w.state = FWS_INIT; 2561 iter->w.node = iter->w.root; 2562 WARN_ON(iter->w.skip); 2563 iter->w.skip = iter->w.count; 2564 } 2565 } 2566 2567 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2568 { 2569 int r; 2570 struct fib6_info *n; 2571 struct net *net = seq_file_net(seq); 2572 struct ipv6_route_iter *iter = seq->private; 2573 2574 ++(*pos); 2575 if (!v) 2576 goto iter_table; 2577 2578 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2579 if (n) 2580 return n; 2581 2582 iter_table: 2583 ipv6_route_check_sernum(iter); 2584 spin_lock_bh(&iter->tbl->tb6_lock); 2585 r = fib6_walk_continue(&iter->w); 2586 spin_unlock_bh(&iter->tbl->tb6_lock); 2587 if (r > 0) { 2588 return iter->w.leaf; 2589 } else if (r < 0) { 2590 fib6_walker_unlink(net, &iter->w); 2591 return NULL; 2592 } 2593 fib6_walker_unlink(net, &iter->w); 2594 2595 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2596 if (!iter->tbl) 2597 return NULL; 2598 2599 ipv6_route_seq_setup_walk(iter, net); 2600 goto iter_table; 2601 } 2602 2603 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2604 __acquires(RCU_BH) 2605 { 2606 struct net *net = seq_file_net(seq); 2607 struct ipv6_route_iter *iter = seq->private; 2608 2609 rcu_read_lock_bh(); 2610 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2611 iter->skip = *pos; 2612 2613 if (iter->tbl) { 2614 ipv6_route_seq_setup_walk(iter, net); 2615 return ipv6_route_seq_next(seq, NULL, pos); 2616 } else { 2617 return NULL; 2618 } 2619 } 2620 2621 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2622 { 2623 struct fib6_walker *w = &iter->w; 2624 return w->node && !(w->state == FWS_U && w->node == w->root); 2625 } 2626 2627 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2628 __releases(RCU_BH) 2629 { 2630 struct net *net = seq_file_net(seq); 2631 struct ipv6_route_iter *iter = seq->private; 2632 2633 if (ipv6_route_iter_active(iter)) 2634 fib6_walker_unlink(net, &iter->w); 2635 2636 rcu_read_unlock_bh(); 2637 } 2638 2639 const struct seq_operations ipv6_route_seq_ops = { 2640 .start = ipv6_route_seq_start, 2641 .next = ipv6_route_seq_next, 2642 .stop = ipv6_route_seq_stop, 2643 .show = ipv6_route_seq_show 2644 }; 2645 #endif /* CONFIG_PROC_FS */ 2646