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