1 /* 2 * Linux INET6 implementation 3 * Forwarding Information Database 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * Changes: 14 * Yuji SEKIYA @USAGI: Support default route on router node; 15 * remove ip6_null_entry from the top of 16 * routing table. 17 * Ville Nuorvala: Fixed routing subtrees. 18 */ 19 20 #define pr_fmt(fmt) "IPv6: " fmt 21 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/net.h> 25 #include <linux/route.h> 26 #include <linux/netdevice.h> 27 #include <linux/in6.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/slab.h> 31 32 #include <net/ip.h> 33 #include <net/ipv6.h> 34 #include <net/ndisc.h> 35 #include <net/addrconf.h> 36 #include <net/lwtunnel.h> 37 #include <net/fib_notifier.h> 38 39 #include <net/ip6_fib.h> 40 #include <net/ip6_route.h> 41 42 static struct kmem_cache *fib6_node_kmem __read_mostly; 43 44 struct fib6_cleaner { 45 struct fib6_walker w; 46 struct net *net; 47 int (*func)(struct fib6_info *, void *arg); 48 int sernum; 49 void *arg; 50 bool skip_notify; 51 }; 52 53 #ifdef CONFIG_IPV6_SUBTREES 54 #define FWS_INIT FWS_S 55 #else 56 #define FWS_INIT FWS_L 57 #endif 58 59 static struct fib6_info *fib6_find_prefix(struct net *net, 60 struct fib6_table *table, 61 struct fib6_node *fn); 62 static struct fib6_node *fib6_repair_tree(struct net *net, 63 struct fib6_table *table, 64 struct fib6_node *fn); 65 static int fib6_walk(struct net *net, struct fib6_walker *w); 66 static int fib6_walk_continue(struct fib6_walker *w); 67 68 /* 69 * A routing update causes an increase of the serial number on the 70 * affected subtree. This allows for cached routes to be asynchronously 71 * tested when modifications are made to the destination cache as a 72 * result of redirects, path MTU changes, etc. 73 */ 74 75 static void fib6_gc_timer_cb(struct timer_list *t); 76 77 #define FOR_WALKERS(net, w) \ 78 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 79 80 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 81 { 82 write_lock_bh(&net->ipv6.fib6_walker_lock); 83 list_add(&w->lh, &net->ipv6.fib6_walkers); 84 write_unlock_bh(&net->ipv6.fib6_walker_lock); 85 } 86 87 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 88 { 89 write_lock_bh(&net->ipv6.fib6_walker_lock); 90 list_del(&w->lh); 91 write_unlock_bh(&net->ipv6.fib6_walker_lock); 92 } 93 94 static int fib6_new_sernum(struct net *net) 95 { 96 int new, old; 97 98 do { 99 old = atomic_read(&net->ipv6.fib6_sernum); 100 new = old < INT_MAX ? old + 1 : 1; 101 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 102 old, new) != old); 103 return new; 104 } 105 106 enum { 107 FIB6_NO_SERNUM_CHANGE = 0, 108 }; 109 110 void fib6_update_sernum(struct net *net, struct fib6_info *f6i) 111 { 112 struct fib6_node *fn; 113 114 fn = rcu_dereference_protected(f6i->fib6_node, 115 lockdep_is_held(&f6i->fib6_table->tb6_lock)); 116 if (fn) 117 fn->fn_sernum = fib6_new_sernum(net); 118 } 119 120 /* 121 * Auxiliary address test functions for the radix tree. 122 * 123 * These assume a 32bit processor (although it will work on 124 * 64bit processors) 125 */ 126 127 /* 128 * test bit 129 */ 130 #if defined(__LITTLE_ENDIAN) 131 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 132 #else 133 # define BITOP_BE32_SWIZZLE 0 134 #endif 135 136 static __be32 addr_bit_set(const void *token, int fn_bit) 137 { 138 const __be32 *addr = token; 139 /* 140 * Here, 141 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 142 * is optimized version of 143 * htonl(1 << ((~fn_bit)&0x1F)) 144 * See include/asm-generic/bitops/le.h. 145 */ 146 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 147 addr[fn_bit >> 5]; 148 } 149 150 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags) 151 { 152 struct fib6_info *f6i; 153 154 f6i = kzalloc(sizeof(*f6i), gfp_flags); 155 if (!f6i) 156 return NULL; 157 158 f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); 159 if (!f6i->rt6i_pcpu) { 160 kfree(f6i); 161 return NULL; 162 } 163 164 INIT_LIST_HEAD(&f6i->fib6_siblings); 165 refcount_set(&f6i->fib6_ref, 1); 166 167 return f6i; 168 } 169 170 void fib6_info_destroy_rcu(struct rcu_head *head) 171 { 172 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu); 173 struct rt6_exception_bucket *bucket; 174 175 WARN_ON(f6i->fib6_node); 176 177 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1); 178 kfree(bucket); 179 180 if (f6i->rt6i_pcpu) { 181 int cpu; 182 183 for_each_possible_cpu(cpu) { 184 struct rt6_info **ppcpu_rt; 185 struct rt6_info *pcpu_rt; 186 187 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 188 pcpu_rt = *ppcpu_rt; 189 if (pcpu_rt) { 190 dst_dev_put(&pcpu_rt->dst); 191 dst_release(&pcpu_rt->dst); 192 *ppcpu_rt = NULL; 193 } 194 } 195 196 free_percpu(f6i->rt6i_pcpu); 197 } 198 199 fib6_nh_release(&f6i->fib6_nh); 200 201 ip_fib_metrics_put(f6i->fib6_metrics); 202 203 kfree(f6i); 204 } 205 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); 206 207 static struct fib6_node *node_alloc(struct net *net) 208 { 209 struct fib6_node *fn; 210 211 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 212 if (fn) 213 net->ipv6.rt6_stats->fib_nodes++; 214 215 return fn; 216 } 217 218 static void node_free_immediate(struct net *net, struct fib6_node *fn) 219 { 220 kmem_cache_free(fib6_node_kmem, fn); 221 net->ipv6.rt6_stats->fib_nodes--; 222 } 223 224 static void node_free_rcu(struct rcu_head *head) 225 { 226 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 227 228 kmem_cache_free(fib6_node_kmem, fn); 229 } 230 231 static void node_free(struct net *net, struct fib6_node *fn) 232 { 233 call_rcu(&fn->rcu, node_free_rcu); 234 net->ipv6.rt6_stats->fib_nodes--; 235 } 236 237 static void fib6_free_table(struct fib6_table *table) 238 { 239 inetpeer_invalidate_tree(&table->tb6_peers); 240 kfree(table); 241 } 242 243 static void fib6_link_table(struct net *net, struct fib6_table *tb) 244 { 245 unsigned int h; 246 247 /* 248 * Initialize table lock at a single place to give lockdep a key, 249 * tables aren't visible prior to being linked to the list. 250 */ 251 spin_lock_init(&tb->tb6_lock); 252 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 253 254 /* 255 * No protection necessary, this is the only list mutatation 256 * operation, tables never disappear once they exist. 257 */ 258 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 259 } 260 261 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 262 263 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 264 { 265 struct fib6_table *table; 266 267 table = kzalloc(sizeof(*table), GFP_ATOMIC); 268 if (table) { 269 table->tb6_id = id; 270 rcu_assign_pointer(table->tb6_root.leaf, 271 net->ipv6.fib6_null_entry); 272 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 273 inet_peer_base_init(&table->tb6_peers); 274 } 275 276 return table; 277 } 278 279 struct fib6_table *fib6_new_table(struct net *net, u32 id) 280 { 281 struct fib6_table *tb; 282 283 if (id == 0) 284 id = RT6_TABLE_MAIN; 285 tb = fib6_get_table(net, id); 286 if (tb) 287 return tb; 288 289 tb = fib6_alloc_table(net, id); 290 if (tb) 291 fib6_link_table(net, tb); 292 293 return tb; 294 } 295 EXPORT_SYMBOL_GPL(fib6_new_table); 296 297 struct fib6_table *fib6_get_table(struct net *net, u32 id) 298 { 299 struct fib6_table *tb; 300 struct hlist_head *head; 301 unsigned int h; 302 303 if (id == 0) 304 id = RT6_TABLE_MAIN; 305 h = id & (FIB6_TABLE_HASHSZ - 1); 306 rcu_read_lock(); 307 head = &net->ipv6.fib_table_hash[h]; 308 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 309 if (tb->tb6_id == id) { 310 rcu_read_unlock(); 311 return tb; 312 } 313 } 314 rcu_read_unlock(); 315 316 return NULL; 317 } 318 EXPORT_SYMBOL_GPL(fib6_get_table); 319 320 static void __net_init fib6_tables_init(struct net *net) 321 { 322 fib6_link_table(net, net->ipv6.fib6_main_tbl); 323 fib6_link_table(net, net->ipv6.fib6_local_tbl); 324 } 325 #else 326 327 struct fib6_table *fib6_new_table(struct net *net, u32 id) 328 { 329 return fib6_get_table(net, id); 330 } 331 332 struct fib6_table *fib6_get_table(struct net *net, u32 id) 333 { 334 return net->ipv6.fib6_main_tbl; 335 } 336 337 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 338 const struct sk_buff *skb, 339 int flags, pol_lookup_t lookup) 340 { 341 struct rt6_info *rt; 342 343 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 344 if (rt->dst.error == -EAGAIN) { 345 ip6_rt_put(rt); 346 rt = net->ipv6.ip6_null_entry; 347 dst_hold(&rt->dst); 348 } 349 350 return &rt->dst; 351 } 352 353 /* called with rcu lock held; no reference taken on fib6_info */ 354 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 355 struct fib6_result *res, int flags) 356 { 357 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, 358 res, flags); 359 } 360 361 static void __net_init fib6_tables_init(struct net *net) 362 { 363 fib6_link_table(net, net->ipv6.fib6_main_tbl); 364 } 365 366 #endif 367 368 unsigned int fib6_tables_seq_read(struct net *net) 369 { 370 unsigned int h, fib_seq = 0; 371 372 rcu_read_lock(); 373 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 374 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 375 struct fib6_table *tb; 376 377 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 378 fib_seq += tb->fib_seq; 379 } 380 rcu_read_unlock(); 381 382 return fib_seq; 383 } 384 385 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 386 enum fib_event_type event_type, 387 struct fib6_info *rt) 388 { 389 struct fib6_entry_notifier_info info = { 390 .rt = rt, 391 }; 392 393 return call_fib6_notifier(nb, net, event_type, &info.info); 394 } 395 396 int call_fib6_entry_notifiers(struct net *net, 397 enum fib_event_type event_type, 398 struct fib6_info *rt, 399 struct netlink_ext_ack *extack) 400 { 401 struct fib6_entry_notifier_info info = { 402 .info.extack = extack, 403 .rt = rt, 404 }; 405 406 rt->fib6_table->fib_seq++; 407 return call_fib6_notifiers(net, event_type, &info.info); 408 } 409 410 struct fib6_dump_arg { 411 struct net *net; 412 struct notifier_block *nb; 413 }; 414 415 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 416 { 417 if (rt == arg->net->ipv6.fib6_null_entry) 418 return; 419 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 420 } 421 422 static int fib6_node_dump(struct fib6_walker *w) 423 { 424 struct fib6_info *rt; 425 426 for_each_fib6_walker_rt(w) 427 fib6_rt_dump(rt, w->args); 428 w->leaf = NULL; 429 return 0; 430 } 431 432 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 433 struct fib6_walker *w) 434 { 435 w->root = &tb->tb6_root; 436 spin_lock_bh(&tb->tb6_lock); 437 fib6_walk(net, w); 438 spin_unlock_bh(&tb->tb6_lock); 439 } 440 441 /* Called with rcu_read_lock() */ 442 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 443 { 444 struct fib6_dump_arg arg; 445 struct fib6_walker *w; 446 unsigned int h; 447 448 w = kzalloc(sizeof(*w), GFP_ATOMIC); 449 if (!w) 450 return -ENOMEM; 451 452 w->func = fib6_node_dump; 453 arg.net = net; 454 arg.nb = nb; 455 w->args = &arg; 456 457 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 458 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 459 struct fib6_table *tb; 460 461 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 462 fib6_table_dump(net, tb, w); 463 } 464 465 kfree(w); 466 467 return 0; 468 } 469 470 static int fib6_dump_node(struct fib6_walker *w) 471 { 472 int res; 473 struct fib6_info *rt; 474 475 for_each_fib6_walker_rt(w) { 476 res = rt6_dump_route(rt, w->args); 477 if (res < 0) { 478 /* Frame is full, suspend walking */ 479 w->leaf = rt; 480 return 1; 481 } 482 483 /* Multipath routes are dumped in one route with the 484 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 485 * last sibling of this route (no need to dump the 486 * sibling routes again) 487 */ 488 if (rt->fib6_nsiblings) 489 rt = list_last_entry(&rt->fib6_siblings, 490 struct fib6_info, 491 fib6_siblings); 492 } 493 w->leaf = NULL; 494 return 0; 495 } 496 497 static void fib6_dump_end(struct netlink_callback *cb) 498 { 499 struct net *net = sock_net(cb->skb->sk); 500 struct fib6_walker *w = (void *)cb->args[2]; 501 502 if (w) { 503 if (cb->args[4]) { 504 cb->args[4] = 0; 505 fib6_walker_unlink(net, w); 506 } 507 cb->args[2] = 0; 508 kfree(w); 509 } 510 cb->done = (void *)cb->args[3]; 511 cb->args[1] = 3; 512 } 513 514 static int fib6_dump_done(struct netlink_callback *cb) 515 { 516 fib6_dump_end(cb); 517 return cb->done ? cb->done(cb) : 0; 518 } 519 520 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 521 struct netlink_callback *cb) 522 { 523 struct net *net = sock_net(skb->sk); 524 struct fib6_walker *w; 525 int res; 526 527 w = (void *)cb->args[2]; 528 w->root = &table->tb6_root; 529 530 if (cb->args[4] == 0) { 531 w->count = 0; 532 w->skip = 0; 533 534 spin_lock_bh(&table->tb6_lock); 535 res = fib6_walk(net, w); 536 spin_unlock_bh(&table->tb6_lock); 537 if (res > 0) { 538 cb->args[4] = 1; 539 cb->args[5] = w->root->fn_sernum; 540 } 541 } else { 542 if (cb->args[5] != w->root->fn_sernum) { 543 /* Begin at the root if the tree changed */ 544 cb->args[5] = w->root->fn_sernum; 545 w->state = FWS_INIT; 546 w->node = w->root; 547 w->skip = w->count; 548 } else 549 w->skip = 0; 550 551 spin_lock_bh(&table->tb6_lock); 552 res = fib6_walk_continue(w); 553 spin_unlock_bh(&table->tb6_lock); 554 if (res <= 0) { 555 fib6_walker_unlink(net, w); 556 cb->args[4] = 0; 557 } 558 } 559 560 return res; 561 } 562 563 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 564 { 565 const struct nlmsghdr *nlh = cb->nlh; 566 struct net *net = sock_net(skb->sk); 567 struct rt6_rtnl_dump_arg arg = {}; 568 unsigned int h, s_h; 569 unsigned int e = 0, s_e; 570 struct fib6_walker *w; 571 struct fib6_table *tb; 572 struct hlist_head *head; 573 int res = 0; 574 575 if (cb->strict_check) { 576 int err; 577 578 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb); 579 if (err < 0) 580 return err; 581 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 582 struct rtmsg *rtm = nlmsg_data(nlh); 583 584 arg.filter.flags = rtm->rtm_flags & (RTM_F_PREFIX|RTM_F_CLONED); 585 } 586 587 /* fib entries are never clones */ 588 if (arg.filter.flags & RTM_F_CLONED) 589 goto out; 590 591 w = (void *)cb->args[2]; 592 if (!w) { 593 /* New dump: 594 * 595 * 1. hook callback destructor. 596 */ 597 cb->args[3] = (long)cb->done; 598 cb->done = fib6_dump_done; 599 600 /* 601 * 2. allocate and initialize walker. 602 */ 603 w = kzalloc(sizeof(*w), GFP_ATOMIC); 604 if (!w) 605 return -ENOMEM; 606 w->func = fib6_dump_node; 607 cb->args[2] = (long)w; 608 } 609 610 arg.skb = skb; 611 arg.cb = cb; 612 arg.net = net; 613 w->args = &arg; 614 615 if (arg.filter.table_id) { 616 tb = fib6_get_table(net, arg.filter.table_id); 617 if (!tb) { 618 if (arg.filter.dump_all_families) 619 goto out; 620 621 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist"); 622 return -ENOENT; 623 } 624 625 if (!cb->args[0]) { 626 res = fib6_dump_table(tb, skb, cb); 627 if (!res) 628 cb->args[0] = 1; 629 } 630 goto out; 631 } 632 633 s_h = cb->args[0]; 634 s_e = cb->args[1]; 635 636 rcu_read_lock(); 637 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 638 e = 0; 639 head = &net->ipv6.fib_table_hash[h]; 640 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 641 if (e < s_e) 642 goto next; 643 res = fib6_dump_table(tb, skb, cb); 644 if (res != 0) 645 goto out_unlock; 646 next: 647 e++; 648 } 649 } 650 out_unlock: 651 rcu_read_unlock(); 652 cb->args[1] = e; 653 cb->args[0] = h; 654 out: 655 res = res < 0 ? res : skb->len; 656 if (res <= 0) 657 fib6_dump_end(cb); 658 return res; 659 } 660 661 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 662 { 663 if (!f6i) 664 return; 665 666 if (f6i->fib6_metrics == &dst_default_metrics) { 667 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 668 669 if (!p) 670 return; 671 672 refcount_set(&p->refcnt, 1); 673 f6i->fib6_metrics = p; 674 } 675 676 f6i->fib6_metrics->metrics[metric - 1] = val; 677 } 678 679 /* 680 * Routing Table 681 * 682 * return the appropriate node for a routing tree "add" operation 683 * by either creating and inserting or by returning an existing 684 * node. 685 */ 686 687 static struct fib6_node *fib6_add_1(struct net *net, 688 struct fib6_table *table, 689 struct fib6_node *root, 690 struct in6_addr *addr, int plen, 691 int offset, int allow_create, 692 int replace_required, 693 struct netlink_ext_ack *extack) 694 { 695 struct fib6_node *fn, *in, *ln; 696 struct fib6_node *pn = NULL; 697 struct rt6key *key; 698 int bit; 699 __be32 dir = 0; 700 701 RT6_TRACE("fib6_add_1\n"); 702 703 /* insert node in tree */ 704 705 fn = root; 706 707 do { 708 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 709 lockdep_is_held(&table->tb6_lock)); 710 key = (struct rt6key *)((u8 *)leaf + offset); 711 712 /* 713 * Prefix match 714 */ 715 if (plen < fn->fn_bit || 716 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 717 if (!allow_create) { 718 if (replace_required) { 719 NL_SET_ERR_MSG(extack, 720 "Can not replace route - no match found"); 721 pr_warn("Can't replace route, no match found\n"); 722 return ERR_PTR(-ENOENT); 723 } 724 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 725 } 726 goto insert_above; 727 } 728 729 /* 730 * Exact match ? 731 */ 732 733 if (plen == fn->fn_bit) { 734 /* clean up an intermediate node */ 735 if (!(fn->fn_flags & RTN_RTINFO)) { 736 RCU_INIT_POINTER(fn->leaf, NULL); 737 fib6_info_release(leaf); 738 /* remove null_entry in the root node */ 739 } else if (fn->fn_flags & RTN_TL_ROOT && 740 rcu_access_pointer(fn->leaf) == 741 net->ipv6.fib6_null_entry) { 742 RCU_INIT_POINTER(fn->leaf, NULL); 743 } 744 745 return fn; 746 } 747 748 /* 749 * We have more bits to go 750 */ 751 752 /* Try to walk down on tree. */ 753 dir = addr_bit_set(addr, fn->fn_bit); 754 pn = fn; 755 fn = dir ? 756 rcu_dereference_protected(fn->right, 757 lockdep_is_held(&table->tb6_lock)) : 758 rcu_dereference_protected(fn->left, 759 lockdep_is_held(&table->tb6_lock)); 760 } while (fn); 761 762 if (!allow_create) { 763 /* We should not create new node because 764 * NLM_F_REPLACE was specified without NLM_F_CREATE 765 * I assume it is safe to require NLM_F_CREATE when 766 * REPLACE flag is used! Later we may want to remove the 767 * check for replace_required, because according 768 * to netlink specification, NLM_F_CREATE 769 * MUST be specified if new route is created. 770 * That would keep IPv6 consistent with IPv4 771 */ 772 if (replace_required) { 773 NL_SET_ERR_MSG(extack, 774 "Can not replace route - no match found"); 775 pr_warn("Can't replace route, no match found\n"); 776 return ERR_PTR(-ENOENT); 777 } 778 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 779 } 780 /* 781 * We walked to the bottom of tree. 782 * Create new leaf node without children. 783 */ 784 785 ln = node_alloc(net); 786 787 if (!ln) 788 return ERR_PTR(-ENOMEM); 789 ln->fn_bit = plen; 790 RCU_INIT_POINTER(ln->parent, pn); 791 792 if (dir) 793 rcu_assign_pointer(pn->right, ln); 794 else 795 rcu_assign_pointer(pn->left, ln); 796 797 return ln; 798 799 800 insert_above: 801 /* 802 * split since we don't have a common prefix anymore or 803 * we have a less significant route. 804 * we've to insert an intermediate node on the list 805 * this new node will point to the one we need to create 806 * and the current 807 */ 808 809 pn = rcu_dereference_protected(fn->parent, 810 lockdep_is_held(&table->tb6_lock)); 811 812 /* find 1st bit in difference between the 2 addrs. 813 814 See comment in __ipv6_addr_diff: bit may be an invalid value, 815 but if it is >= plen, the value is ignored in any case. 816 */ 817 818 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 819 820 /* 821 * (intermediate)[in] 822 * / \ 823 * (new leaf node)[ln] (old node)[fn] 824 */ 825 if (plen > bit) { 826 in = node_alloc(net); 827 ln = node_alloc(net); 828 829 if (!in || !ln) { 830 if (in) 831 node_free_immediate(net, in); 832 if (ln) 833 node_free_immediate(net, ln); 834 return ERR_PTR(-ENOMEM); 835 } 836 837 /* 838 * new intermediate node. 839 * RTN_RTINFO will 840 * be off since that an address that chooses one of 841 * the branches would not match less specific routes 842 * in the other branch 843 */ 844 845 in->fn_bit = bit; 846 847 RCU_INIT_POINTER(in->parent, pn); 848 in->leaf = fn->leaf; 849 fib6_info_hold(rcu_dereference_protected(in->leaf, 850 lockdep_is_held(&table->tb6_lock))); 851 852 /* update parent pointer */ 853 if (dir) 854 rcu_assign_pointer(pn->right, in); 855 else 856 rcu_assign_pointer(pn->left, in); 857 858 ln->fn_bit = plen; 859 860 RCU_INIT_POINTER(ln->parent, in); 861 rcu_assign_pointer(fn->parent, in); 862 863 if (addr_bit_set(addr, bit)) { 864 rcu_assign_pointer(in->right, ln); 865 rcu_assign_pointer(in->left, fn); 866 } else { 867 rcu_assign_pointer(in->left, ln); 868 rcu_assign_pointer(in->right, fn); 869 } 870 } else { /* plen <= bit */ 871 872 /* 873 * (new leaf node)[ln] 874 * / \ 875 * (old node)[fn] NULL 876 */ 877 878 ln = node_alloc(net); 879 880 if (!ln) 881 return ERR_PTR(-ENOMEM); 882 883 ln->fn_bit = plen; 884 885 RCU_INIT_POINTER(ln->parent, pn); 886 887 if (addr_bit_set(&key->addr, plen)) 888 RCU_INIT_POINTER(ln->right, fn); 889 else 890 RCU_INIT_POINTER(ln->left, fn); 891 892 rcu_assign_pointer(fn->parent, ln); 893 894 if (dir) 895 rcu_assign_pointer(pn->right, ln); 896 else 897 rcu_assign_pointer(pn->left, ln); 898 } 899 return ln; 900 } 901 902 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 903 const struct fib6_table *table) 904 { 905 int cpu; 906 907 /* Make sure rt6_make_pcpu_route() wont add other percpu routes 908 * while we are cleaning them here. 909 */ 910 f6i->fib6_destroying = 1; 911 mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */ 912 913 /* release the reference to this fib entry from 914 * all of its cached pcpu routes 915 */ 916 for_each_possible_cpu(cpu) { 917 struct rt6_info **ppcpu_rt; 918 struct rt6_info *pcpu_rt; 919 920 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 921 pcpu_rt = *ppcpu_rt; 922 if (pcpu_rt) { 923 struct fib6_info *from; 924 925 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 926 fib6_info_release(from); 927 } 928 } 929 } 930 931 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 932 struct net *net) 933 { 934 struct fib6_table *table = rt->fib6_table; 935 936 if (rt->rt6i_pcpu) 937 fib6_drop_pcpu_from(rt, table); 938 939 if (refcount_read(&rt->fib6_ref) != 1) { 940 /* This route is used as dummy address holder in some split 941 * nodes. It is not leaked, but it still holds other resources, 942 * which must be released in time. So, scan ascendant nodes 943 * and replace dummy references to this route with references 944 * to still alive ones. 945 */ 946 while (fn) { 947 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 948 lockdep_is_held(&table->tb6_lock)); 949 struct fib6_info *new_leaf; 950 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 951 new_leaf = fib6_find_prefix(net, table, fn); 952 fib6_info_hold(new_leaf); 953 954 rcu_assign_pointer(fn->leaf, new_leaf); 955 fib6_info_release(rt); 956 } 957 fn = rcu_dereference_protected(fn->parent, 958 lockdep_is_held(&table->tb6_lock)); 959 } 960 } 961 } 962 963 /* 964 * Insert routing information in a node. 965 */ 966 967 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 968 struct nl_info *info, 969 struct netlink_ext_ack *extack) 970 { 971 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 972 lockdep_is_held(&rt->fib6_table->tb6_lock)); 973 struct fib6_info *iter = NULL; 974 struct fib6_info __rcu **ins; 975 struct fib6_info __rcu **fallback_ins = NULL; 976 int replace = (info->nlh && 977 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 978 int add = (!info->nlh || 979 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 980 int found = 0; 981 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 982 u16 nlflags = NLM_F_EXCL; 983 int err; 984 985 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 986 nlflags |= NLM_F_APPEND; 987 988 ins = &fn->leaf; 989 990 for (iter = leaf; iter; 991 iter = rcu_dereference_protected(iter->fib6_next, 992 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 993 /* 994 * Search for duplicates 995 */ 996 997 if (iter->fib6_metric == rt->fib6_metric) { 998 /* 999 * Same priority level 1000 */ 1001 if (info->nlh && 1002 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 1003 return -EEXIST; 1004 1005 nlflags &= ~NLM_F_EXCL; 1006 if (replace) { 1007 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 1008 found++; 1009 break; 1010 } 1011 if (rt_can_ecmp) 1012 fallback_ins = fallback_ins ?: ins; 1013 goto next_iter; 1014 } 1015 1016 if (rt6_duplicate_nexthop(iter, rt)) { 1017 if (rt->fib6_nsiblings) 1018 rt->fib6_nsiblings = 0; 1019 if (!(iter->fib6_flags & RTF_EXPIRES)) 1020 return -EEXIST; 1021 if (!(rt->fib6_flags & RTF_EXPIRES)) 1022 fib6_clean_expires(iter); 1023 else 1024 fib6_set_expires(iter, rt->expires); 1025 1026 if (rt->fib6_pmtu) 1027 fib6_metric_set(iter, RTAX_MTU, 1028 rt->fib6_pmtu); 1029 return -EEXIST; 1030 } 1031 /* If we have the same destination and the same metric, 1032 * but not the same gateway, then the route we try to 1033 * add is sibling to this route, increment our counter 1034 * of siblings, and later we will add our route to the 1035 * list. 1036 * Only static routes (which don't have flag 1037 * RTF_EXPIRES) are used for ECMPv6. 1038 * 1039 * To avoid long list, we only had siblings if the 1040 * route have a gateway. 1041 */ 1042 if (rt_can_ecmp && 1043 rt6_qualify_for_ecmp(iter)) 1044 rt->fib6_nsiblings++; 1045 } 1046 1047 if (iter->fib6_metric > rt->fib6_metric) 1048 break; 1049 1050 next_iter: 1051 ins = &iter->fib6_next; 1052 } 1053 1054 if (fallback_ins && !found) { 1055 /* No ECMP-able route found, replace first non-ECMP one */ 1056 ins = fallback_ins; 1057 iter = rcu_dereference_protected(*ins, 1058 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1059 found++; 1060 } 1061 1062 /* Reset round-robin state, if necessary */ 1063 if (ins == &fn->leaf) 1064 fn->rr_ptr = NULL; 1065 1066 /* Link this route to others same route. */ 1067 if (rt->fib6_nsiblings) { 1068 unsigned int fib6_nsiblings; 1069 struct fib6_info *sibling, *temp_sibling; 1070 1071 /* Find the first route that have the same metric */ 1072 sibling = leaf; 1073 while (sibling) { 1074 if (sibling->fib6_metric == rt->fib6_metric && 1075 rt6_qualify_for_ecmp(sibling)) { 1076 list_add_tail(&rt->fib6_siblings, 1077 &sibling->fib6_siblings); 1078 break; 1079 } 1080 sibling = rcu_dereference_protected(sibling->fib6_next, 1081 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1082 } 1083 /* For each sibling in the list, increment the counter of 1084 * siblings. BUG() if counters does not match, list of siblings 1085 * is broken! 1086 */ 1087 fib6_nsiblings = 0; 1088 list_for_each_entry_safe(sibling, temp_sibling, 1089 &rt->fib6_siblings, fib6_siblings) { 1090 sibling->fib6_nsiblings++; 1091 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1092 fib6_nsiblings++; 1093 } 1094 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1095 rt6_multipath_rebalance(temp_sibling); 1096 } 1097 1098 /* 1099 * insert node 1100 */ 1101 if (!replace) { 1102 if (!add) 1103 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1104 1105 add: 1106 nlflags |= NLM_F_CREATE; 1107 1108 err = call_fib6_entry_notifiers(info->nl_net, 1109 FIB_EVENT_ENTRY_ADD, 1110 rt, extack); 1111 if (err) 1112 return err; 1113 1114 rcu_assign_pointer(rt->fib6_next, iter); 1115 fib6_info_hold(rt); 1116 rcu_assign_pointer(rt->fib6_node, fn); 1117 rcu_assign_pointer(*ins, rt); 1118 if (!info->skip_notify) 1119 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1120 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1121 1122 if (!(fn->fn_flags & RTN_RTINFO)) { 1123 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1124 fn->fn_flags |= RTN_RTINFO; 1125 } 1126 1127 } else { 1128 int nsiblings; 1129 1130 if (!found) { 1131 if (add) 1132 goto add; 1133 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1134 return -ENOENT; 1135 } 1136 1137 err = call_fib6_entry_notifiers(info->nl_net, 1138 FIB_EVENT_ENTRY_REPLACE, 1139 rt, extack); 1140 if (err) 1141 return err; 1142 1143 fib6_info_hold(rt); 1144 rcu_assign_pointer(rt->fib6_node, fn); 1145 rt->fib6_next = iter->fib6_next; 1146 rcu_assign_pointer(*ins, rt); 1147 if (!info->skip_notify) 1148 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1149 if (!(fn->fn_flags & RTN_RTINFO)) { 1150 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1151 fn->fn_flags |= RTN_RTINFO; 1152 } 1153 nsiblings = iter->fib6_nsiblings; 1154 iter->fib6_node = NULL; 1155 fib6_purge_rt(iter, fn, info->nl_net); 1156 if (rcu_access_pointer(fn->rr_ptr) == iter) 1157 fn->rr_ptr = NULL; 1158 fib6_info_release(iter); 1159 1160 if (nsiblings) { 1161 /* Replacing an ECMP route, remove all siblings */ 1162 ins = &rt->fib6_next; 1163 iter = rcu_dereference_protected(*ins, 1164 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1165 while (iter) { 1166 if (iter->fib6_metric > rt->fib6_metric) 1167 break; 1168 if (rt6_qualify_for_ecmp(iter)) { 1169 *ins = iter->fib6_next; 1170 iter->fib6_node = NULL; 1171 fib6_purge_rt(iter, fn, info->nl_net); 1172 if (rcu_access_pointer(fn->rr_ptr) == iter) 1173 fn->rr_ptr = NULL; 1174 fib6_info_release(iter); 1175 nsiblings--; 1176 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1177 } else { 1178 ins = &iter->fib6_next; 1179 } 1180 iter = rcu_dereference_protected(*ins, 1181 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1182 } 1183 WARN_ON(nsiblings != 0); 1184 } 1185 } 1186 1187 return 0; 1188 } 1189 1190 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1191 { 1192 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1193 (rt->fib6_flags & RTF_EXPIRES)) 1194 mod_timer(&net->ipv6.ip6_fib_timer, 1195 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1196 } 1197 1198 void fib6_force_start_gc(struct net *net) 1199 { 1200 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1201 mod_timer(&net->ipv6.ip6_fib_timer, 1202 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1203 } 1204 1205 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1206 int sernum) 1207 { 1208 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1209 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1210 1211 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1212 smp_wmb(); 1213 while (fn) { 1214 fn->fn_sernum = sernum; 1215 fn = rcu_dereference_protected(fn->parent, 1216 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1217 } 1218 } 1219 1220 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1221 { 1222 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1223 } 1224 1225 /* allow ipv4 to update sernum via ipv6_stub */ 1226 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i) 1227 { 1228 spin_lock_bh(&f6i->fib6_table->tb6_lock); 1229 fib6_update_sernum_upto_root(net, f6i); 1230 spin_unlock_bh(&f6i->fib6_table->tb6_lock); 1231 } 1232 1233 /* 1234 * Add routing information to the routing tree. 1235 * <destination addr>/<source addr> 1236 * with source addr info in sub-trees 1237 * Need to own table->tb6_lock 1238 */ 1239 1240 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1241 struct nl_info *info, struct netlink_ext_ack *extack) 1242 { 1243 struct fib6_table *table = rt->fib6_table; 1244 struct fib6_node *fn, *pn = NULL; 1245 int err = -ENOMEM; 1246 int allow_create = 1; 1247 int replace_required = 0; 1248 int sernum = fib6_new_sernum(info->nl_net); 1249 1250 if (info->nlh) { 1251 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1252 allow_create = 0; 1253 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1254 replace_required = 1; 1255 } 1256 if (!allow_create && !replace_required) 1257 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1258 1259 fn = fib6_add_1(info->nl_net, table, root, 1260 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1261 offsetof(struct fib6_info, fib6_dst), allow_create, 1262 replace_required, extack); 1263 if (IS_ERR(fn)) { 1264 err = PTR_ERR(fn); 1265 fn = NULL; 1266 goto out; 1267 } 1268 1269 pn = fn; 1270 1271 #ifdef CONFIG_IPV6_SUBTREES 1272 if (rt->fib6_src.plen) { 1273 struct fib6_node *sn; 1274 1275 if (!rcu_access_pointer(fn->subtree)) { 1276 struct fib6_node *sfn; 1277 1278 /* 1279 * Create subtree. 1280 * 1281 * fn[main tree] 1282 * | 1283 * sfn[subtree root] 1284 * \ 1285 * sn[new leaf node] 1286 */ 1287 1288 /* Create subtree root node */ 1289 sfn = node_alloc(info->nl_net); 1290 if (!sfn) 1291 goto failure; 1292 1293 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry); 1294 rcu_assign_pointer(sfn->leaf, 1295 info->nl_net->ipv6.fib6_null_entry); 1296 sfn->fn_flags = RTN_ROOT; 1297 1298 /* Now add the first leaf node to new subtree */ 1299 1300 sn = fib6_add_1(info->nl_net, table, sfn, 1301 &rt->fib6_src.addr, rt->fib6_src.plen, 1302 offsetof(struct fib6_info, fib6_src), 1303 allow_create, replace_required, extack); 1304 1305 if (IS_ERR(sn)) { 1306 /* If it is failed, discard just allocated 1307 root, and then (in failure) stale node 1308 in main tree. 1309 */ 1310 node_free_immediate(info->nl_net, sfn); 1311 err = PTR_ERR(sn); 1312 goto failure; 1313 } 1314 1315 /* Now link new subtree to main tree */ 1316 rcu_assign_pointer(sfn->parent, fn); 1317 rcu_assign_pointer(fn->subtree, sfn); 1318 } else { 1319 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1320 &rt->fib6_src.addr, rt->fib6_src.plen, 1321 offsetof(struct fib6_info, fib6_src), 1322 allow_create, replace_required, extack); 1323 1324 if (IS_ERR(sn)) { 1325 err = PTR_ERR(sn); 1326 goto failure; 1327 } 1328 } 1329 1330 if (!rcu_access_pointer(fn->leaf)) { 1331 if (fn->fn_flags & RTN_TL_ROOT) { 1332 /* put back null_entry for root node */ 1333 rcu_assign_pointer(fn->leaf, 1334 info->nl_net->ipv6.fib6_null_entry); 1335 } else { 1336 fib6_info_hold(rt); 1337 rcu_assign_pointer(fn->leaf, rt); 1338 } 1339 } 1340 fn = sn; 1341 } 1342 #endif 1343 1344 err = fib6_add_rt2node(fn, rt, info, extack); 1345 if (!err) { 1346 __fib6_update_sernum_upto_root(rt, sernum); 1347 fib6_start_gc(info->nl_net, rt); 1348 } 1349 1350 out: 1351 if (err) { 1352 #ifdef CONFIG_IPV6_SUBTREES 1353 /* 1354 * If fib6_add_1 has cleared the old leaf pointer in the 1355 * super-tree leaf node we have to find a new one for it. 1356 */ 1357 if (pn != fn) { 1358 struct fib6_info *pn_leaf = 1359 rcu_dereference_protected(pn->leaf, 1360 lockdep_is_held(&table->tb6_lock)); 1361 if (pn_leaf == rt) { 1362 pn_leaf = NULL; 1363 RCU_INIT_POINTER(pn->leaf, NULL); 1364 fib6_info_release(rt); 1365 } 1366 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1367 pn_leaf = fib6_find_prefix(info->nl_net, table, 1368 pn); 1369 #if RT6_DEBUG >= 2 1370 if (!pn_leaf) { 1371 WARN_ON(!pn_leaf); 1372 pn_leaf = 1373 info->nl_net->ipv6.fib6_null_entry; 1374 } 1375 #endif 1376 fib6_info_hold(pn_leaf); 1377 rcu_assign_pointer(pn->leaf, pn_leaf); 1378 } 1379 } 1380 #endif 1381 goto failure; 1382 } 1383 return err; 1384 1385 failure: 1386 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1387 * 1. fn is an intermediate node and we failed to add the new 1388 * route to it in both subtree creation failure and fib6_add_rt2node() 1389 * failure case. 1390 * 2. fn is the root node in the table and we fail to add the first 1391 * default route to it. 1392 */ 1393 if (fn && 1394 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1395 (fn->fn_flags & RTN_TL_ROOT && 1396 !rcu_access_pointer(fn->leaf)))) 1397 fib6_repair_tree(info->nl_net, table, fn); 1398 return err; 1399 } 1400 1401 /* 1402 * Routing tree lookup 1403 * 1404 */ 1405 1406 struct lookup_args { 1407 int offset; /* key offset on fib6_info */ 1408 const struct in6_addr *addr; /* search key */ 1409 }; 1410 1411 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1412 struct lookup_args *args) 1413 { 1414 struct fib6_node *fn; 1415 __be32 dir; 1416 1417 if (unlikely(args->offset == 0)) 1418 return NULL; 1419 1420 /* 1421 * Descend on a tree 1422 */ 1423 1424 fn = root; 1425 1426 for (;;) { 1427 struct fib6_node *next; 1428 1429 dir = addr_bit_set(args->addr, fn->fn_bit); 1430 1431 next = dir ? rcu_dereference(fn->right) : 1432 rcu_dereference(fn->left); 1433 1434 if (next) { 1435 fn = next; 1436 continue; 1437 } 1438 break; 1439 } 1440 1441 while (fn) { 1442 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1443 1444 if (subtree || fn->fn_flags & RTN_RTINFO) { 1445 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1446 struct rt6key *key; 1447 1448 if (!leaf) 1449 goto backtrack; 1450 1451 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1452 1453 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1454 #ifdef CONFIG_IPV6_SUBTREES 1455 if (subtree) { 1456 struct fib6_node *sfn; 1457 sfn = fib6_node_lookup_1(subtree, 1458 args + 1); 1459 if (!sfn) 1460 goto backtrack; 1461 fn = sfn; 1462 } 1463 #endif 1464 if (fn->fn_flags & RTN_RTINFO) 1465 return fn; 1466 } 1467 } 1468 backtrack: 1469 if (fn->fn_flags & RTN_ROOT) 1470 break; 1471 1472 fn = rcu_dereference(fn->parent); 1473 } 1474 1475 return NULL; 1476 } 1477 1478 /* called with rcu_read_lock() held 1479 */ 1480 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1481 const struct in6_addr *daddr, 1482 const struct in6_addr *saddr) 1483 { 1484 struct fib6_node *fn; 1485 struct lookup_args args[] = { 1486 { 1487 .offset = offsetof(struct fib6_info, fib6_dst), 1488 .addr = daddr, 1489 }, 1490 #ifdef CONFIG_IPV6_SUBTREES 1491 { 1492 .offset = offsetof(struct fib6_info, fib6_src), 1493 .addr = saddr, 1494 }, 1495 #endif 1496 { 1497 .offset = 0, /* sentinel */ 1498 } 1499 }; 1500 1501 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1502 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1503 fn = root; 1504 1505 return fn; 1506 } 1507 1508 /* 1509 * Get node with specified destination prefix (and source prefix, 1510 * if subtrees are used) 1511 * exact_match == true means we try to find fn with exact match of 1512 * the passed in prefix addr 1513 * exact_match == false means we try to find fn with longest prefix 1514 * match of the passed in prefix addr. This is useful for finding fn 1515 * for cached route as it will be stored in the exception table under 1516 * the node with longest prefix length. 1517 */ 1518 1519 1520 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1521 const struct in6_addr *addr, 1522 int plen, int offset, 1523 bool exact_match) 1524 { 1525 struct fib6_node *fn, *prev = NULL; 1526 1527 for (fn = root; fn ; ) { 1528 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1529 struct rt6key *key; 1530 1531 /* This node is being deleted */ 1532 if (!leaf) { 1533 if (plen <= fn->fn_bit) 1534 goto out; 1535 else 1536 goto next; 1537 } 1538 1539 key = (struct rt6key *)((u8 *)leaf + offset); 1540 1541 /* 1542 * Prefix match 1543 */ 1544 if (plen < fn->fn_bit || 1545 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1546 goto out; 1547 1548 if (plen == fn->fn_bit) 1549 return fn; 1550 1551 prev = fn; 1552 1553 next: 1554 /* 1555 * We have more bits to go 1556 */ 1557 if (addr_bit_set(addr, fn->fn_bit)) 1558 fn = rcu_dereference(fn->right); 1559 else 1560 fn = rcu_dereference(fn->left); 1561 } 1562 out: 1563 if (exact_match) 1564 return NULL; 1565 else 1566 return prev; 1567 } 1568 1569 struct fib6_node *fib6_locate(struct fib6_node *root, 1570 const struct in6_addr *daddr, int dst_len, 1571 const struct in6_addr *saddr, int src_len, 1572 bool exact_match) 1573 { 1574 struct fib6_node *fn; 1575 1576 fn = fib6_locate_1(root, daddr, dst_len, 1577 offsetof(struct fib6_info, fib6_dst), 1578 exact_match); 1579 1580 #ifdef CONFIG_IPV6_SUBTREES 1581 if (src_len) { 1582 WARN_ON(saddr == NULL); 1583 if (fn) { 1584 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1585 1586 if (subtree) { 1587 fn = fib6_locate_1(subtree, saddr, src_len, 1588 offsetof(struct fib6_info, fib6_src), 1589 exact_match); 1590 } 1591 } 1592 } 1593 #endif 1594 1595 if (fn && fn->fn_flags & RTN_RTINFO) 1596 return fn; 1597 1598 return NULL; 1599 } 1600 1601 1602 /* 1603 * Deletion 1604 * 1605 */ 1606 1607 static struct fib6_info *fib6_find_prefix(struct net *net, 1608 struct fib6_table *table, 1609 struct fib6_node *fn) 1610 { 1611 struct fib6_node *child_left, *child_right; 1612 1613 if (fn->fn_flags & RTN_ROOT) 1614 return net->ipv6.fib6_null_entry; 1615 1616 while (fn) { 1617 child_left = rcu_dereference_protected(fn->left, 1618 lockdep_is_held(&table->tb6_lock)); 1619 child_right = rcu_dereference_protected(fn->right, 1620 lockdep_is_held(&table->tb6_lock)); 1621 if (child_left) 1622 return rcu_dereference_protected(child_left->leaf, 1623 lockdep_is_held(&table->tb6_lock)); 1624 if (child_right) 1625 return rcu_dereference_protected(child_right->leaf, 1626 lockdep_is_held(&table->tb6_lock)); 1627 1628 fn = FIB6_SUBTREE(fn); 1629 } 1630 return NULL; 1631 } 1632 1633 /* 1634 * Called to trim the tree of intermediate nodes when possible. "fn" 1635 * is the node we want to try and remove. 1636 * Need to own table->tb6_lock 1637 */ 1638 1639 static struct fib6_node *fib6_repair_tree(struct net *net, 1640 struct fib6_table *table, 1641 struct fib6_node *fn) 1642 { 1643 int children; 1644 int nstate; 1645 struct fib6_node *child; 1646 struct fib6_walker *w; 1647 int iter = 0; 1648 1649 /* Set fn->leaf to null_entry for root node. */ 1650 if (fn->fn_flags & RTN_TL_ROOT) { 1651 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1652 return fn; 1653 } 1654 1655 for (;;) { 1656 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1657 lockdep_is_held(&table->tb6_lock)); 1658 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1659 lockdep_is_held(&table->tb6_lock)); 1660 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1661 lockdep_is_held(&table->tb6_lock)); 1662 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1663 lockdep_is_held(&table->tb6_lock)); 1664 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1665 lockdep_is_held(&table->tb6_lock)); 1666 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1667 lockdep_is_held(&table->tb6_lock)); 1668 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1669 lockdep_is_held(&table->tb6_lock)); 1670 struct fib6_info *new_fn_leaf; 1671 1672 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1673 iter++; 1674 1675 WARN_ON(fn->fn_flags & RTN_RTINFO); 1676 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1677 WARN_ON(fn_leaf); 1678 1679 children = 0; 1680 child = NULL; 1681 if (fn_r) 1682 child = fn_r, children |= 1; 1683 if (fn_l) 1684 child = fn_l, children |= 2; 1685 1686 if (children == 3 || FIB6_SUBTREE(fn) 1687 #ifdef CONFIG_IPV6_SUBTREES 1688 /* Subtree root (i.e. fn) may have one child */ 1689 || (children && fn->fn_flags & RTN_ROOT) 1690 #endif 1691 ) { 1692 new_fn_leaf = fib6_find_prefix(net, table, fn); 1693 #if RT6_DEBUG >= 2 1694 if (!new_fn_leaf) { 1695 WARN_ON(!new_fn_leaf); 1696 new_fn_leaf = net->ipv6.fib6_null_entry; 1697 } 1698 #endif 1699 fib6_info_hold(new_fn_leaf); 1700 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1701 return pn; 1702 } 1703 1704 #ifdef CONFIG_IPV6_SUBTREES 1705 if (FIB6_SUBTREE(pn) == fn) { 1706 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1707 RCU_INIT_POINTER(pn->subtree, NULL); 1708 nstate = FWS_L; 1709 } else { 1710 WARN_ON(fn->fn_flags & RTN_ROOT); 1711 #endif 1712 if (pn_r == fn) 1713 rcu_assign_pointer(pn->right, child); 1714 else if (pn_l == fn) 1715 rcu_assign_pointer(pn->left, child); 1716 #if RT6_DEBUG >= 2 1717 else 1718 WARN_ON(1); 1719 #endif 1720 if (child) 1721 rcu_assign_pointer(child->parent, pn); 1722 nstate = FWS_R; 1723 #ifdef CONFIG_IPV6_SUBTREES 1724 } 1725 #endif 1726 1727 read_lock(&net->ipv6.fib6_walker_lock); 1728 FOR_WALKERS(net, w) { 1729 if (!child) { 1730 if (w->node == fn) { 1731 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1732 w->node = pn; 1733 w->state = nstate; 1734 } 1735 } else { 1736 if (w->node == fn) { 1737 w->node = child; 1738 if (children&2) { 1739 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1740 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1741 } else { 1742 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1743 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1744 } 1745 } 1746 } 1747 } 1748 read_unlock(&net->ipv6.fib6_walker_lock); 1749 1750 node_free(net, fn); 1751 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1752 return pn; 1753 1754 RCU_INIT_POINTER(pn->leaf, NULL); 1755 fib6_info_release(pn_leaf); 1756 fn = pn; 1757 } 1758 } 1759 1760 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1761 struct fib6_info __rcu **rtp, struct nl_info *info) 1762 { 1763 struct fib6_walker *w; 1764 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1765 lockdep_is_held(&table->tb6_lock)); 1766 struct net *net = info->nl_net; 1767 1768 RT6_TRACE("fib6_del_route\n"); 1769 1770 /* Unlink it */ 1771 *rtp = rt->fib6_next; 1772 rt->fib6_node = NULL; 1773 net->ipv6.rt6_stats->fib_rt_entries--; 1774 net->ipv6.rt6_stats->fib_discarded_routes++; 1775 1776 /* Flush all cached dst in exception table */ 1777 rt6_flush_exceptions(rt); 1778 1779 /* Reset round-robin state, if necessary */ 1780 if (rcu_access_pointer(fn->rr_ptr) == rt) 1781 fn->rr_ptr = NULL; 1782 1783 /* Remove this entry from other siblings */ 1784 if (rt->fib6_nsiblings) { 1785 struct fib6_info *sibling, *next_sibling; 1786 1787 list_for_each_entry_safe(sibling, next_sibling, 1788 &rt->fib6_siblings, fib6_siblings) 1789 sibling->fib6_nsiblings--; 1790 rt->fib6_nsiblings = 0; 1791 list_del_init(&rt->fib6_siblings); 1792 rt6_multipath_rebalance(next_sibling); 1793 } 1794 1795 /* Adjust walkers */ 1796 read_lock(&net->ipv6.fib6_walker_lock); 1797 FOR_WALKERS(net, w) { 1798 if (w->state == FWS_C && w->leaf == rt) { 1799 RT6_TRACE("walker %p adjusted by delroute\n", w); 1800 w->leaf = rcu_dereference_protected(rt->fib6_next, 1801 lockdep_is_held(&table->tb6_lock)); 1802 if (!w->leaf) 1803 w->state = FWS_U; 1804 } 1805 } 1806 read_unlock(&net->ipv6.fib6_walker_lock); 1807 1808 /* If it was last route, call fib6_repair_tree() to: 1809 * 1. For root node, put back null_entry as how the table was created. 1810 * 2. For other nodes, expunge its radix tree node. 1811 */ 1812 if (!rcu_access_pointer(fn->leaf)) { 1813 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1814 fn->fn_flags &= ~RTN_RTINFO; 1815 net->ipv6.rt6_stats->fib_route_nodes--; 1816 } 1817 fn = fib6_repair_tree(net, table, fn); 1818 } 1819 1820 fib6_purge_rt(rt, fn, net); 1821 1822 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1823 if (!info->skip_notify) 1824 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1825 fib6_info_release(rt); 1826 } 1827 1828 /* Need to own table->tb6_lock */ 1829 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1830 { 1831 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1832 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1833 struct fib6_table *table = rt->fib6_table; 1834 struct net *net = info->nl_net; 1835 struct fib6_info __rcu **rtp; 1836 struct fib6_info __rcu **rtp_next; 1837 1838 if (!fn || rt == net->ipv6.fib6_null_entry) 1839 return -ENOENT; 1840 1841 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1842 1843 /* 1844 * Walk the leaf entries looking for ourself 1845 */ 1846 1847 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1848 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1849 lockdep_is_held(&table->tb6_lock)); 1850 if (rt == cur) { 1851 fib6_del_route(table, fn, rtp, info); 1852 return 0; 1853 } 1854 rtp_next = &cur->fib6_next; 1855 } 1856 return -ENOENT; 1857 } 1858 1859 /* 1860 * Tree traversal function. 1861 * 1862 * Certainly, it is not interrupt safe. 1863 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1864 * It means, that we can modify tree during walking 1865 * and use this function for garbage collection, clone pruning, 1866 * cleaning tree when a device goes down etc. etc. 1867 * 1868 * It guarantees that every node will be traversed, 1869 * and that it will be traversed only once. 1870 * 1871 * Callback function w->func may return: 1872 * 0 -> continue walking. 1873 * positive value -> walking is suspended (used by tree dumps, 1874 * and probably by gc, if it will be split to several slices) 1875 * negative value -> terminate walking. 1876 * 1877 * The function itself returns: 1878 * 0 -> walk is complete. 1879 * >0 -> walk is incomplete (i.e. suspended) 1880 * <0 -> walk is terminated by an error. 1881 * 1882 * This function is called with tb6_lock held. 1883 */ 1884 1885 static int fib6_walk_continue(struct fib6_walker *w) 1886 { 1887 struct fib6_node *fn, *pn, *left, *right; 1888 1889 /* w->root should always be table->tb6_root */ 1890 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1891 1892 for (;;) { 1893 fn = w->node; 1894 if (!fn) 1895 return 0; 1896 1897 switch (w->state) { 1898 #ifdef CONFIG_IPV6_SUBTREES 1899 case FWS_S: 1900 if (FIB6_SUBTREE(fn)) { 1901 w->node = FIB6_SUBTREE(fn); 1902 continue; 1903 } 1904 w->state = FWS_L; 1905 #endif 1906 /* fall through */ 1907 case FWS_L: 1908 left = rcu_dereference_protected(fn->left, 1); 1909 if (left) { 1910 w->node = left; 1911 w->state = FWS_INIT; 1912 continue; 1913 } 1914 w->state = FWS_R; 1915 /* fall through */ 1916 case FWS_R: 1917 right = rcu_dereference_protected(fn->right, 1); 1918 if (right) { 1919 w->node = right; 1920 w->state = FWS_INIT; 1921 continue; 1922 } 1923 w->state = FWS_C; 1924 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1925 /* fall through */ 1926 case FWS_C: 1927 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1928 int err; 1929 1930 if (w->skip) { 1931 w->skip--; 1932 goto skip; 1933 } 1934 1935 err = w->func(w); 1936 if (err) 1937 return err; 1938 1939 w->count++; 1940 continue; 1941 } 1942 skip: 1943 w->state = FWS_U; 1944 /* fall through */ 1945 case FWS_U: 1946 if (fn == w->root) 1947 return 0; 1948 pn = rcu_dereference_protected(fn->parent, 1); 1949 left = rcu_dereference_protected(pn->left, 1); 1950 right = rcu_dereference_protected(pn->right, 1); 1951 w->node = pn; 1952 #ifdef CONFIG_IPV6_SUBTREES 1953 if (FIB6_SUBTREE(pn) == fn) { 1954 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1955 w->state = FWS_L; 1956 continue; 1957 } 1958 #endif 1959 if (left == fn) { 1960 w->state = FWS_R; 1961 continue; 1962 } 1963 if (right == fn) { 1964 w->state = FWS_C; 1965 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1966 continue; 1967 } 1968 #if RT6_DEBUG >= 2 1969 WARN_ON(1); 1970 #endif 1971 } 1972 } 1973 } 1974 1975 static int fib6_walk(struct net *net, struct fib6_walker *w) 1976 { 1977 int res; 1978 1979 w->state = FWS_INIT; 1980 w->node = w->root; 1981 1982 fib6_walker_link(net, w); 1983 res = fib6_walk_continue(w); 1984 if (res <= 0) 1985 fib6_walker_unlink(net, w); 1986 return res; 1987 } 1988 1989 static int fib6_clean_node(struct fib6_walker *w) 1990 { 1991 int res; 1992 struct fib6_info *rt; 1993 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1994 struct nl_info info = { 1995 .nl_net = c->net, 1996 .skip_notify = c->skip_notify, 1997 }; 1998 1999 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 2000 w->node->fn_sernum != c->sernum) 2001 w->node->fn_sernum = c->sernum; 2002 2003 if (!c->func) { 2004 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 2005 w->leaf = NULL; 2006 return 0; 2007 } 2008 2009 for_each_fib6_walker_rt(w) { 2010 res = c->func(rt, c->arg); 2011 if (res == -1) { 2012 w->leaf = rt; 2013 res = fib6_del(rt, &info); 2014 if (res) { 2015 #if RT6_DEBUG >= 2 2016 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 2017 __func__, rt, 2018 rcu_access_pointer(rt->fib6_node), 2019 res); 2020 #endif 2021 continue; 2022 } 2023 return 0; 2024 } else if (res == -2) { 2025 if (WARN_ON(!rt->fib6_nsiblings)) 2026 continue; 2027 rt = list_last_entry(&rt->fib6_siblings, 2028 struct fib6_info, fib6_siblings); 2029 continue; 2030 } 2031 WARN_ON(res != 0); 2032 } 2033 w->leaf = rt; 2034 return 0; 2035 } 2036 2037 /* 2038 * Convenient frontend to tree walker. 2039 * 2040 * func is called on each route. 2041 * It may return -2 -> skip multipath route. 2042 * -1 -> delete this route. 2043 * 0 -> continue walking 2044 */ 2045 2046 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2047 int (*func)(struct fib6_info *, void *arg), 2048 int sernum, void *arg, bool skip_notify) 2049 { 2050 struct fib6_cleaner c; 2051 2052 c.w.root = root; 2053 c.w.func = fib6_clean_node; 2054 c.w.count = 0; 2055 c.w.skip = 0; 2056 c.func = func; 2057 c.sernum = sernum; 2058 c.arg = arg; 2059 c.net = net; 2060 c.skip_notify = skip_notify; 2061 2062 fib6_walk(net, &c.w); 2063 } 2064 2065 static void __fib6_clean_all(struct net *net, 2066 int (*func)(struct fib6_info *, void *), 2067 int sernum, void *arg, bool skip_notify) 2068 { 2069 struct fib6_table *table; 2070 struct hlist_head *head; 2071 unsigned int h; 2072 2073 rcu_read_lock(); 2074 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2075 head = &net->ipv6.fib_table_hash[h]; 2076 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2077 spin_lock_bh(&table->tb6_lock); 2078 fib6_clean_tree(net, &table->tb6_root, 2079 func, sernum, arg, skip_notify); 2080 spin_unlock_bh(&table->tb6_lock); 2081 } 2082 } 2083 rcu_read_unlock(); 2084 } 2085 2086 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2087 void *arg) 2088 { 2089 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false); 2090 } 2091 2092 void fib6_clean_all_skip_notify(struct net *net, 2093 int (*func)(struct fib6_info *, void *), 2094 void *arg) 2095 { 2096 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true); 2097 } 2098 2099 static void fib6_flush_trees(struct net *net) 2100 { 2101 int new_sernum = fib6_new_sernum(net); 2102 2103 __fib6_clean_all(net, NULL, new_sernum, NULL, false); 2104 } 2105 2106 /* 2107 * Garbage collection 2108 */ 2109 2110 static int fib6_age(struct fib6_info *rt, void *arg) 2111 { 2112 struct fib6_gc_args *gc_args = arg; 2113 unsigned long now = jiffies; 2114 2115 /* 2116 * check addrconf expiration here. 2117 * Routes are expired even if they are in use. 2118 */ 2119 2120 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2121 if (time_after(now, rt->expires)) { 2122 RT6_TRACE("expiring %p\n", rt); 2123 return -1; 2124 } 2125 gc_args->more++; 2126 } 2127 2128 /* Also age clones in the exception table. 2129 * Note, that clones are aged out 2130 * only if they are not in use now. 2131 */ 2132 rt6_age_exceptions(rt, gc_args, now); 2133 2134 return 0; 2135 } 2136 2137 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2138 { 2139 struct fib6_gc_args gc_args; 2140 unsigned long now; 2141 2142 if (force) { 2143 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2144 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2145 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2146 return; 2147 } 2148 gc_args.timeout = expires ? (int)expires : 2149 net->ipv6.sysctl.ip6_rt_gc_interval; 2150 gc_args.more = 0; 2151 2152 fib6_clean_all(net, fib6_age, &gc_args); 2153 now = jiffies; 2154 net->ipv6.ip6_rt_last_gc = now; 2155 2156 if (gc_args.more) 2157 mod_timer(&net->ipv6.ip6_fib_timer, 2158 round_jiffies(now 2159 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2160 else 2161 del_timer(&net->ipv6.ip6_fib_timer); 2162 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2163 } 2164 2165 static void fib6_gc_timer_cb(struct timer_list *t) 2166 { 2167 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2168 2169 fib6_run_gc(0, arg, true); 2170 } 2171 2172 static int __net_init fib6_net_init(struct net *net) 2173 { 2174 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2175 int err; 2176 2177 err = fib6_notifier_init(net); 2178 if (err) 2179 return err; 2180 2181 spin_lock_init(&net->ipv6.fib6_gc_lock); 2182 rwlock_init(&net->ipv6.fib6_walker_lock); 2183 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2184 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2185 2186 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2187 if (!net->ipv6.rt6_stats) 2188 goto out_timer; 2189 2190 /* Avoid false sharing : Use at least a full cache line */ 2191 size = max_t(size_t, size, L1_CACHE_BYTES); 2192 2193 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2194 if (!net->ipv6.fib_table_hash) 2195 goto out_rt6_stats; 2196 2197 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2198 GFP_KERNEL); 2199 if (!net->ipv6.fib6_main_tbl) 2200 goto out_fib_table_hash; 2201 2202 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2203 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2204 net->ipv6.fib6_null_entry); 2205 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2206 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2207 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2208 2209 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2210 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2211 GFP_KERNEL); 2212 if (!net->ipv6.fib6_local_tbl) 2213 goto out_fib6_main_tbl; 2214 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2215 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2216 net->ipv6.fib6_null_entry); 2217 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2218 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2219 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2220 #endif 2221 fib6_tables_init(net); 2222 2223 return 0; 2224 2225 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2226 out_fib6_main_tbl: 2227 kfree(net->ipv6.fib6_main_tbl); 2228 #endif 2229 out_fib_table_hash: 2230 kfree(net->ipv6.fib_table_hash); 2231 out_rt6_stats: 2232 kfree(net->ipv6.rt6_stats); 2233 out_timer: 2234 fib6_notifier_exit(net); 2235 return -ENOMEM; 2236 } 2237 2238 static void fib6_net_exit(struct net *net) 2239 { 2240 unsigned int i; 2241 2242 del_timer_sync(&net->ipv6.ip6_fib_timer); 2243 2244 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2245 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2246 struct hlist_node *tmp; 2247 struct fib6_table *tb; 2248 2249 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2250 hlist_del(&tb->tb6_hlist); 2251 fib6_free_table(tb); 2252 } 2253 } 2254 2255 kfree(net->ipv6.fib_table_hash); 2256 kfree(net->ipv6.rt6_stats); 2257 fib6_notifier_exit(net); 2258 } 2259 2260 static struct pernet_operations fib6_net_ops = { 2261 .init = fib6_net_init, 2262 .exit = fib6_net_exit, 2263 }; 2264 2265 int __init fib6_init(void) 2266 { 2267 int ret = -ENOMEM; 2268 2269 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2270 sizeof(struct fib6_node), 2271 0, SLAB_HWCACHE_ALIGN, 2272 NULL); 2273 if (!fib6_node_kmem) 2274 goto out; 2275 2276 ret = register_pernet_subsys(&fib6_net_ops); 2277 if (ret) 2278 goto out_kmem_cache_create; 2279 2280 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2281 inet6_dump_fib, 0); 2282 if (ret) 2283 goto out_unregister_subsys; 2284 2285 __fib6_flush_trees = fib6_flush_trees; 2286 out: 2287 return ret; 2288 2289 out_unregister_subsys: 2290 unregister_pernet_subsys(&fib6_net_ops); 2291 out_kmem_cache_create: 2292 kmem_cache_destroy(fib6_node_kmem); 2293 goto out; 2294 } 2295 2296 void fib6_gc_cleanup(void) 2297 { 2298 unregister_pernet_subsys(&fib6_net_ops); 2299 kmem_cache_destroy(fib6_node_kmem); 2300 } 2301 2302 #ifdef CONFIG_PROC_FS 2303 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2304 { 2305 struct fib6_info *rt = v; 2306 struct ipv6_route_iter *iter = seq->private; 2307 unsigned int flags = rt->fib6_flags; 2308 const struct net_device *dev; 2309 2310 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2311 2312 #ifdef CONFIG_IPV6_SUBTREES 2313 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2314 #else 2315 seq_puts(seq, "00000000000000000000000000000000 00 "); 2316 #endif 2317 if (rt->fib6_nh.fib_nh_gw_family) { 2318 flags |= RTF_GATEWAY; 2319 seq_printf(seq, "%pi6", &rt->fib6_nh.fib_nh_gw6); 2320 } else { 2321 seq_puts(seq, "00000000000000000000000000000000"); 2322 } 2323 2324 dev = rt->fib6_nh.fib_nh_dev; 2325 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2326 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0, 2327 flags, dev ? dev->name : ""); 2328 iter->w.leaf = NULL; 2329 return 0; 2330 } 2331 2332 static int ipv6_route_yield(struct fib6_walker *w) 2333 { 2334 struct ipv6_route_iter *iter = w->args; 2335 2336 if (!iter->skip) 2337 return 1; 2338 2339 do { 2340 iter->w.leaf = rcu_dereference_protected( 2341 iter->w.leaf->fib6_next, 2342 lockdep_is_held(&iter->tbl->tb6_lock)); 2343 iter->skip--; 2344 if (!iter->skip && iter->w.leaf) 2345 return 1; 2346 } while (iter->w.leaf); 2347 2348 return 0; 2349 } 2350 2351 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2352 struct net *net) 2353 { 2354 memset(&iter->w, 0, sizeof(iter->w)); 2355 iter->w.func = ipv6_route_yield; 2356 iter->w.root = &iter->tbl->tb6_root; 2357 iter->w.state = FWS_INIT; 2358 iter->w.node = iter->w.root; 2359 iter->w.args = iter; 2360 iter->sernum = iter->w.root->fn_sernum; 2361 INIT_LIST_HEAD(&iter->w.lh); 2362 fib6_walker_link(net, &iter->w); 2363 } 2364 2365 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2366 struct net *net) 2367 { 2368 unsigned int h; 2369 struct hlist_node *node; 2370 2371 if (tbl) { 2372 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2373 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2374 } else { 2375 h = 0; 2376 node = NULL; 2377 } 2378 2379 while (!node && h < FIB6_TABLE_HASHSZ) { 2380 node = rcu_dereference_bh( 2381 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2382 } 2383 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2384 } 2385 2386 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2387 { 2388 if (iter->sernum != iter->w.root->fn_sernum) { 2389 iter->sernum = iter->w.root->fn_sernum; 2390 iter->w.state = FWS_INIT; 2391 iter->w.node = iter->w.root; 2392 WARN_ON(iter->w.skip); 2393 iter->w.skip = iter->w.count; 2394 } 2395 } 2396 2397 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2398 { 2399 int r; 2400 struct fib6_info *n; 2401 struct net *net = seq_file_net(seq); 2402 struct ipv6_route_iter *iter = seq->private; 2403 2404 if (!v) 2405 goto iter_table; 2406 2407 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2408 if (n) { 2409 ++*pos; 2410 return n; 2411 } 2412 2413 iter_table: 2414 ipv6_route_check_sernum(iter); 2415 spin_lock_bh(&iter->tbl->tb6_lock); 2416 r = fib6_walk_continue(&iter->w); 2417 spin_unlock_bh(&iter->tbl->tb6_lock); 2418 if (r > 0) { 2419 if (v) 2420 ++*pos; 2421 return iter->w.leaf; 2422 } else if (r < 0) { 2423 fib6_walker_unlink(net, &iter->w); 2424 return NULL; 2425 } 2426 fib6_walker_unlink(net, &iter->w); 2427 2428 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2429 if (!iter->tbl) 2430 return NULL; 2431 2432 ipv6_route_seq_setup_walk(iter, net); 2433 goto iter_table; 2434 } 2435 2436 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2437 __acquires(RCU_BH) 2438 { 2439 struct net *net = seq_file_net(seq); 2440 struct ipv6_route_iter *iter = seq->private; 2441 2442 rcu_read_lock_bh(); 2443 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2444 iter->skip = *pos; 2445 2446 if (iter->tbl) { 2447 ipv6_route_seq_setup_walk(iter, net); 2448 return ipv6_route_seq_next(seq, NULL, pos); 2449 } else { 2450 return NULL; 2451 } 2452 } 2453 2454 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2455 { 2456 struct fib6_walker *w = &iter->w; 2457 return w->node && !(w->state == FWS_U && w->node == w->root); 2458 } 2459 2460 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2461 __releases(RCU_BH) 2462 { 2463 struct net *net = seq_file_net(seq); 2464 struct ipv6_route_iter *iter = seq->private; 2465 2466 if (ipv6_route_iter_active(iter)) 2467 fib6_walker_unlink(net, &iter->w); 2468 2469 rcu_read_unlock_bh(); 2470 } 2471 2472 const struct seq_operations ipv6_route_seq_ops = { 2473 .start = ipv6_route_seq_start, 2474 .next = ipv6_route_seq_next, 2475 .stop = ipv6_route_seq_stop, 2476 .show = ipv6_route_seq_show 2477 }; 2478 #endif /* CONFIG_PROC_FS */ 2479