net/ipv6/ip6_fib.c

   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/ipv6.h>
  33 #include <net/ndisc.h>
  34 #include <net/addrconf.h>
  35 #include <net/lwtunnel.h>
  36
  37 #include <net/ip6_fib.h>
  38 #include <net/ip6_route.h>
  39
  40 #define RT6_DEBUG 2
  41
  42 #if RT6_DEBUG >= 3
  43 #define RT6_TRACE(x...) pr_debug(x)
  44 #else
  45 #define RT6_TRACE(x...) do { ; } while (0)
  46 #endif
  47
  48 static struct kmem_cache *fib6_node_kmem __read_mostly;
  49
  50 struct fib6_cleaner {
  51         struct fib6_walker w;
  52         struct net *net;
  53         int (*func)(struct rt6_info *, void *arg);
  54         int sernum;
  55         void *arg;
  56 };
  57
  58 static DEFINE_RWLOCK(fib6_walker_lock);
  59
  60 #ifdef CONFIG_IPV6_SUBTREES
  61 #define FWS_INIT FWS_S
  62 #else
  63 #define FWS_INIT FWS_L
  64 #endif
  65
  66 static void fib6_prune_clones(struct net *net, struct fib6_node *fn);
  67 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
  68 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
  69 static int fib6_walk(struct fib6_walker *w);
  70 static int fib6_walk_continue(struct fib6_walker *w);
  71
  72 /*
  73  *      A routing update causes an increase of the serial number on the
  74  *      affected subtree. This allows for cached routes to be asynchronously
  75  *      tested when modifications are made to the destination cache as a
  76  *      result of redirects, path MTU changes, etc.
  77  */
  78
  79 static void fib6_gc_timer_cb(unsigned long arg);
  80
  81 static LIST_HEAD(fib6_walkers);
  82 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
  83
  84 static void fib6_walker_link(struct fib6_walker *w)
  85 {
  86         write_lock_bh(&fib6_walker_lock);
  87         list_add(&w->lh, &fib6_walkers);
  88         write_unlock_bh(&fib6_walker_lock);
  89 }
  90
  91 static void fib6_walker_unlink(struct fib6_walker *w)
  92 {
  93         write_lock_bh(&fib6_walker_lock);
  94         list_del(&w->lh);
  95         write_unlock_bh(&fib6_walker_lock);
  96 }
  97
  98 static int fib6_new_sernum(struct net *net)
  99 {
 100         int new, old;
 101
 102         do {
 103                 old = atomic_read(&net->ipv6.fib6_sernum);
 104                 new = old < INT_MAX ? old + 1 : 1;
 105         } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
 106                                 old, new) != old);
 107         return new;
 108 }
 109
 110 enum {
 111         FIB6_NO_SERNUM_CHANGE = 0,
 112 };
 113
 114 /*
 115  *      Auxiliary address test functions for the radix tree.
 116  *
 117  *      These assume a 32bit processor (although it will work on
 118  *      64bit processors)
 119  */
 120
 121 /*
 122  *      test bit
 123  */
 124 #if defined(__LITTLE_ENDIAN)
 125 # define BITOP_BE32_SWIZZLE     (0x1F & ~7)
 126 #else
 127 # define BITOP_BE32_SWIZZLE     0
 128 #endif
 129
 130 static __be32 addr_bit_set(const void *token, int fn_bit)
 131 {
 132         const __be32 *addr = token;
 133         /*
 134          * Here,
 135          *      1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
 136          * is optimized version of
 137          *      htonl(1 << ((~fn_bit)&0x1F))
 138          * See include/asm-generic/bitops/le.h.
 139          */
 140         return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
 141                addr[fn_bit >> 5];
 142 }
 143
 144 static struct fib6_node *node_alloc(void)
 145 {
 146         struct fib6_node *fn;
 147
 148         fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
 149
 150         return fn;
 151 }
 152
 153 static void node_free(struct fib6_node *fn)
 154 {
 155         kmem_cache_free(fib6_node_kmem, fn);
 156 }
 157
 158 static void rt6_rcu_free(struct rt6_info *rt)
 159 {
 160         call_rcu(&rt->dst.rcu_head, dst_rcu_free);
 161 }
 162
 163 static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
 164 {
 165         int cpu;
 166
 167         if (!non_pcpu_rt->rt6i_pcpu)
 168                 return;
 169
 170         for_each_possible_cpu(cpu) {
 171                 struct rt6_info **ppcpu_rt;
 172                 struct rt6_info *pcpu_rt;
 173
 174                 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu);
 175                 pcpu_rt = *ppcpu_rt;
 176                 if (pcpu_rt) {
 177                         rt6_rcu_free(pcpu_rt);
 178                         *ppcpu_rt = NULL;
 179                 }
 180         }
 181
 182         non_pcpu_rt->rt6i_pcpu = NULL;
 183 }
 184
 185 static void rt6_release(struct rt6_info *rt)
 186 {
 187         if (atomic_dec_and_test(&rt->rt6i_ref)) {
 188                 rt6_free_pcpu(rt);
 189                 rt6_rcu_free(rt);
 190         }
 191 }
 192
 193 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 194 {
 195         unsigned int h;
 196
 197         /*
 198          * Initialize table lock at a single place to give lockdep a key,
 199          * tables aren't visible prior to being linked to the list.
 200          */
 201         rwlock_init(&tb->tb6_lock);
 202
 203         h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
 204
 205         /*
 206          * No protection necessary, this is the only list mutatation
 207          * operation, tables never disappear once they exist.
 208          */
 209         hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
 210 }
 211
 212 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 213
 214 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
 215 {
 216         struct fib6_table *table;
 217
 218         table = kzalloc(sizeof(*table), GFP_ATOMIC);
 219         if (table) {
 220                 table->tb6_id = id;
 221                 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
 222                 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
 223                 inet_peer_base_init(&table->tb6_peers);
 224         }
 225
 226         return table;
 227 }
 228
 229 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 230 {
 231         struct fib6_table *tb;
 232
 233         if (id == 0)
 234                 id = RT6_TABLE_MAIN;
 235         tb = fib6_get_table(net, id);
 236         if (tb)
 237                 return tb;
 238
 239         tb = fib6_alloc_table(net, id);
 240         if (tb)
 241                 fib6_link_table(net, tb);
 242
 243         return tb;
 244 }
 245
 246 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 247 {
 248         struct fib6_table *tb;
 249         struct hlist_head *head;
 250         unsigned int h;
 251
 252         if (id == 0)
 253                 id = RT6_TABLE_MAIN;
 254         h = id & (FIB6_TABLE_HASHSZ - 1);
 255         rcu_read_lock();
 256         head = &net->ipv6.fib_table_hash[h];
 257         hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
 258                 if (tb->tb6_id == id) {
 259                         rcu_read_unlock();
 260                         return tb;
 261                 }
 262         }
 263         rcu_read_unlock();
 264
 265         return NULL;
 266 }
 267
 268 static void __net_init fib6_tables_init(struct net *net)
 269 {
 270         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 271         fib6_link_table(net, net->ipv6.fib6_local_tbl);
 272 }
 273 #else
 274
 275 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 276 {
 277         return fib6_get_table(net, id);
 278 }
 279
 280 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 281 {
 282           return net->ipv6.fib6_main_tbl;
 283 }
 284
 285 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
 286                                    int flags, pol_lookup_t lookup)
 287 {
 288         struct rt6_info *rt;
 289
 290         rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
 291         if (rt->rt6i_flags & RTF_REJECT &&
 292             rt->dst.error == -EAGAIN) {
 293                 ip6_rt_put(rt);
 294                 rt = net->ipv6.ip6_null_entry;
 295                 dst_hold(&rt->dst);
 296         }
 297
 298         return &rt->dst;
 299 }
 300
 301 static void __net_init fib6_tables_init(struct net *net)
 302 {
 303         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 304 }
 305
 306 #endif
 307
 308 static int fib6_dump_node(struct fib6_walker *w)
 309 {
 310         int res;
 311         struct rt6_info *rt;
 312
 313         for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
 314                 res = rt6_dump_route(rt, w->args);
 315                 if (res < 0) {
 316                         /* Frame is full, suspend walking */
 317                         w->leaf = rt;
 318                         return 1;
 319                 }
 320         }
 321         w->leaf = NULL;
 322         return 0;
 323 }
 324
 325 static void fib6_dump_end(struct netlink_callback *cb)
 326 {
 327         struct fib6_walker *w = (void *)cb->args[2];
 328
 329         if (w) {
 330                 if (cb->args[4]) {
 331                         cb->args[4] = 0;
 332                         fib6_walker_unlink(w);
 333                 }
 334                 cb->args[2] = 0;
 335                 kfree(w);
 336         }
 337         cb->done = (void *)cb->args[3];
 338         cb->args[1] = 3;
 339 }
 340
 341 static int fib6_dump_done(struct netlink_callback *cb)
 342 {
 343         fib6_dump_end(cb);
 344         return cb->done ? cb->done(cb) : 0;
 345 }
 346
 347 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 348                            struct netlink_callback *cb)
 349 {
 350         struct fib6_walker *w;
 351         int res;
 352
 353         w = (void *)cb->args[2];
 354         w->root = &table->tb6_root;
 355
 356         if (cb->args[4] == 0) {
 357                 w->count = 0;
 358                 w->skip = 0;
 359
 360                 read_lock_bh(&table->tb6_lock);
 361                 res = fib6_walk(w);
 362                 read_unlock_bh(&table->tb6_lock);
 363                 if (res > 0) {
 364                         cb->args[4] = 1;
 365                         cb->args[5] = w->root->fn_sernum;
 366                 }
 367         } else {
 368                 if (cb->args[5] != w->root->fn_sernum) {
 369                         /* Begin at the root if the tree changed */
 370                         cb->args[5] = w->root->fn_sernum;
 371                         w->state = FWS_INIT;
 372                         w->node = w->root;
 373                         w->skip = w->count;
 374                 } else
 375                         w->skip = 0;
 376
 377                 read_lock_bh(&table->tb6_lock);
 378                 res = fib6_walk_continue(w);
 379                 read_unlock_bh(&table->tb6_lock);
 380                 if (res <= 0) {
 381                         fib6_walker_unlink(w);
 382                         cb->args[4] = 0;
 383                 }
 384         }
 385
 386         return res;
 387 }
 388
 389 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 390 {
 391         struct net *net = sock_net(skb->sk);
 392         unsigned int h, s_h;
 393         unsigned int e = 0, s_e;
 394         struct rt6_rtnl_dump_arg arg;
 395         struct fib6_walker *w;
 396         struct fib6_table *tb;
 397         struct hlist_head *head;
 398         int res = 0;
 399
 400         s_h = cb->args[0];
 401         s_e = cb->args[1];
 402
 403         w = (void *)cb->args[2];
 404         if (!w) {
 405                 /* New dump:
 406                  *
 407                  * 1. hook callback destructor.
 408                  */
 409                 cb->args[3] = (long)cb->done;
 410                 cb->done = fib6_dump_done;
 411
 412                 /*
 413                  * 2. allocate and initialize walker.
 414                  */
 415                 w = kzalloc(sizeof(*w), GFP_ATOMIC);
 416                 if (!w)
 417                         return -ENOMEM;
 418                 w->func = fib6_dump_node;
 419                 cb->args[2] = (long)w;
 420         }
 421
 422         arg.skb = skb;
 423         arg.cb = cb;
 424         arg.net = net;
 425         w->args = &arg;
 426
 427         rcu_read_lock();
 428         for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
 429                 e = 0;
 430                 head = &net->ipv6.fib_table_hash[h];
 431                 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
 432                         if (e < s_e)
 433                                 goto next;
 434                         res = fib6_dump_table(tb, skb, cb);
 435                         if (res != 0)
 436                                 goto out;
 437 next:
 438                         e++;
 439                 }
 440         }
 441 out:
 442         rcu_read_unlock();
 443         cb->args[1] = e;
 444         cb->args[0] = h;
 445
 446         res = res < 0 ? res : skb->len;
 447         if (res <= 0)
 448                 fib6_dump_end(cb);
 449         return res;
 450 }
 451
 452 /*
 453  *      Routing Table
 454  *
 455  *      return the appropriate node for a routing tree "add" operation
 456  *      by either creating and inserting or by returning an existing
 457  *      node.
 458  */
 459
 460 static struct fib6_node *fib6_add_1(struct fib6_node *root,
 461                                      struct in6_addr *addr, int plen,
 462                                      int offset, int allow_create,
 463                                      int replace_required, int sernum)
 464 {
 465         struct fib6_node *fn, *in, *ln;
 466         struct fib6_node *pn = NULL;
 467         struct rt6key *key;
 468         int     bit;
 469         __be32  dir = 0;
 470
 471         RT6_TRACE("fib6_add_1\n");
 472
 473         /* insert node in tree */
 474
 475         fn = root;
 476
 477         do {
 478                 key = (struct rt6key *)((u8 *)fn->leaf + offset);
 479
 480                 /*
 481                  *      Prefix match
 482                  */
 483                 if (plen < fn->fn_bit ||
 484                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
 485                         if (!allow_create) {
 486                                 if (replace_required) {
 487                                         pr_warn("Can't replace route, no match found\n");
 488                                         return ERR_PTR(-ENOENT);
 489                                 }
 490                                 pr_warn("NLM_F_CREATE should be set when creating new route\n");
 491                         }
 492                         goto insert_above;
 493                 }
 494
 495                 /*
 496                  *      Exact match ?
 497                  */
 498
 499                 if (plen == fn->fn_bit) {
 500                         /* clean up an intermediate node */
 501                         if (!(fn->fn_flags & RTN_RTINFO)) {
 502                                 rt6_release(fn->leaf);
 503                                 fn->leaf = NULL;
 504                         }
 505
 506                         fn->fn_sernum = sernum;
 507
 508                         return fn;
 509                 }
 510
 511                 /*
 512                  *      We have more bits to go
 513                  */
 514
 515                 /* Try to walk down on tree. */
 516                 fn->fn_sernum = sernum;
 517                 dir = addr_bit_set(addr, fn->fn_bit);
 518                 pn = fn;
 519                 fn = dir ? fn->right : fn->left;
 520         } while (fn);
 521
 522         if (!allow_create) {
 523                 /* We should not create new node because
 524                  * NLM_F_REPLACE was specified without NLM_F_CREATE
 525                  * I assume it is safe to require NLM_F_CREATE when
 526                  * REPLACE flag is used! Later we may want to remove the
 527                  * check for replace_required, because according
 528                  * to netlink specification, NLM_F_CREATE
 529                  * MUST be specified if new route is created.
 530                  * That would keep IPv6 consistent with IPv4
 531                  */
 532                 if (replace_required) {
 533                         pr_warn("Can't replace route, no match found\n");
 534                         return ERR_PTR(-ENOENT);
 535                 }
 536                 pr_warn("NLM_F_CREATE should be set when creating new route\n");
 537         }
 538         /*
 539          *      We walked to the bottom of tree.
 540          *      Create new leaf node without children.
 541          */
 542
 543         ln = node_alloc();
 544
 545         if (!ln)
 546                 return ERR_PTR(-ENOMEM);
 547         ln->fn_bit = plen;
 548
 549         ln->parent = pn;
 550         ln->fn_sernum = sernum;
 551
 552         if (dir)
 553                 pn->right = ln;
 554         else
 555                 pn->left  = ln;
 556
 557         return ln;
 558
 559
 560 insert_above:
 561         /*
 562          * split since we don't have a common prefix anymore or
 563          * we have a less significant route.
 564          * we've to insert an intermediate node on the list
 565          * this new node will point to the one we need to create
 566          * and the current
 567          */
 568
 569         pn = fn->parent;
 570
 571         /* find 1st bit in difference between the 2 addrs.
 572
 573            See comment in __ipv6_addr_diff: bit may be an invalid value,
 574            but if it is >= plen, the value is ignored in any case.
 575          */
 576
 577         bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
 578
 579         /*
 580          *              (intermediate)[in]
 581          *                /        \
 582          *      (new leaf node)[ln] (old node)[fn]
 583          */
 584         if (plen > bit) {
 585                 in = node_alloc();
 586                 ln = node_alloc();
 587
 588                 if (!in || !ln) {
 589                         if (in)
 590                                 node_free(in);
 591                         if (ln)
 592                                 node_free(ln);
 593                         return ERR_PTR(-ENOMEM);
 594                 }
 595
 596                 /*
 597                  * new intermediate node.
 598                  * RTN_RTINFO will
 599                  * be off since that an address that chooses one of
 600                  * the branches would not match less specific routes
 601                  * in the other branch
 602                  */
 603
 604                 in->fn_bit = bit;
 605
 606                 in->parent = pn;
 607                 in->leaf = fn->leaf;
 608                 atomic_inc(&in->leaf->rt6i_ref);
 609
 610                 in->fn_sernum = sernum;
 611
 612                 /* update parent pointer */
 613                 if (dir)
 614                         pn->right = in;
 615                 else
 616                         pn->left  = in;
 617
 618                 ln->fn_bit = plen;
 619
 620                 ln->parent = in;
 621                 fn->parent = in;
 622
 623                 ln->fn_sernum = sernum;
 624
 625                 if (addr_bit_set(addr, bit)) {
 626                         in->right = ln;
 627                         in->left  = fn;
 628                 } else {
 629                         in->left  = ln;
 630                         in->right = fn;
 631                 }
 632         } else { /* plen <= bit */
 633
 634                 /*
 635                  *              (new leaf node)[ln]
 636                  *                /        \
 637                  *           (old node)[fn] NULL
 638                  */
 639
 640                 ln = node_alloc();
 641
 642                 if (!ln)
 643                         return ERR_PTR(-ENOMEM);
 644
 645                 ln->fn_bit = plen;
 646
 647                 ln->parent = pn;
 648
 649                 ln->fn_sernum = sernum;
 650
 651                 if (dir)
 652                         pn->right = ln;
 653                 else
 654                         pn->left  = ln;
 655
 656                 if (addr_bit_set(&key->addr, plen))
 657                         ln->right = fn;
 658                 else
 659                         ln->left  = fn;
 660
 661                 fn->parent = ln;
 662         }
 663         return ln;
 664 }
 665
 666 static bool rt6_qualify_for_ecmp(struct rt6_info *rt)
 667 {
 668         return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
 669                RTF_GATEWAY;
 670 }
 671
 672 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
 673 {
 674         int i;
 675
 676         for (i = 0; i < RTAX_MAX; i++) {
 677                 if (test_bit(i, mxc->mx_valid))
 678                         mp[i] = mxc->mx[i];
 679         }
 680 }
 681
 682 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
 683 {
 684         if (!mxc->mx)
 685                 return 0;
 686
 687         if (dst->flags & DST_HOST) {
 688                 u32 *mp = dst_metrics_write_ptr(dst);
 689
 690                 if (unlikely(!mp))
 691                         return -ENOMEM;
 692
 693                 fib6_copy_metrics(mp, mxc);
 694         } else {
 695                 dst_init_metrics(dst, mxc->mx, false);
 696
 697                 /* We've stolen mx now. */
 698                 mxc->mx = NULL;
 699         }
 700
 701         return 0;
 702 }
 703
 704 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
 705                           struct net *net)
 706 {
 707         if (atomic_read(&rt->rt6i_ref) != 1) {
 708                 /* This route is used as dummy address holder in some split
 709                  * nodes. It is not leaked, but it still holds other resources,
 710                  * which must be released in time. So, scan ascendant nodes
 711                  * and replace dummy references to this route with references
 712                  * to still alive ones.
 713                  */
 714                 while (fn) {
 715                         if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
 716                                 fn->leaf = fib6_find_prefix(net, fn);
 717                                 atomic_inc(&fn->leaf->rt6i_ref);
 718                                 rt6_release(rt);
 719                         }
 720                         fn = fn->parent;
 721                 }
 722                 /* No more references are possible at this point. */
 723                 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
 724         }
 725 }
 726
 727 /*
 728  *      Insert routing information in a node.
 729  */
 730
 731 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 732                             struct nl_info *info, struct mx6_config *mxc)
 733 {
 734         struct rt6_info *iter = NULL;
 735         struct rt6_info **ins;
 736         struct rt6_info **fallback_ins = NULL;
 737         int replace = (info->nlh &&
 738                        (info->nlh->nlmsg_flags & NLM_F_REPLACE));
 739         int add = (!info->nlh ||
 740                    (info->nlh->nlmsg_flags & NLM_F_CREATE));
 741         int found = 0;
 742         bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
 743         int err;
 744
 745         ins = &fn->leaf;
 746
 747         for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
 748                 /*
 749                  *      Search for duplicates
 750                  */
 751
 752                 if (iter->rt6i_metric == rt->rt6i_metric) {
 753                         /*
 754                          *      Same priority level
 755                          */
 756                         if (info->nlh &&
 757                             (info->nlh->nlmsg_flags & NLM_F_EXCL))
 758                                 return -EEXIST;
 759                         if (replace) {
 760                                 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
 761                                         found++;
 762                                         break;
 763                                 }
 764                                 if (rt_can_ecmp)
 765                                         fallback_ins = fallback_ins ?: ins;
 766                                 goto next_iter;
 767                         }
 768
 769                         if (iter->dst.dev == rt->dst.dev &&
 770                             iter->rt6i_idev == rt->rt6i_idev &&
 771                             ipv6_addr_equal(&iter->rt6i_gateway,
 772                                             &rt->rt6i_gateway)) {
 773                                 if (rt->rt6i_nsiblings)
 774                                         rt->rt6i_nsiblings = 0;
 775                                 if (!(iter->rt6i_flags & RTF_EXPIRES))
 776                                         return -EEXIST;
 777                                 if (!(rt->rt6i_flags & RTF_EXPIRES))
 778                                         rt6_clean_expires(iter);
 779                                 else
 780                                         rt6_set_expires(iter, rt->dst.expires);
 781                                 iter->rt6i_pmtu = rt->rt6i_pmtu;
 782                                 return -EEXIST;
 783                         }
 784                         /* If we have the same destination and the same metric,
 785                          * but not the same gateway, then the route we try to
 786                          * add is sibling to this route, increment our counter
 787                          * of siblings, and later we will add our route to the
 788                          * list.
 789                          * Only static routes (which don't have flag
 790                          * RTF_EXPIRES) are used for ECMPv6.
 791                          *
 792                          * To avoid long list, we only had siblings if the
 793                          * route have a gateway.
 794                          */
 795                         if (rt_can_ecmp &&
 796                             rt6_qualify_for_ecmp(iter))
 797                                 rt->rt6i_nsiblings++;
 798                 }
 799
 800                 if (iter->rt6i_metric > rt->rt6i_metric)
 801                         break;
 802
 803 next_iter:
 804                 ins = &iter->dst.rt6_next;
 805         }
 806
 807         if (fallback_ins && !found) {
 808                 /* No ECMP-able route found, replace first non-ECMP one */
 809                 ins = fallback_ins;
 810                 iter = *ins;
 811                 found++;
 812         }
 813
 814         /* Reset round-robin state, if necessary */
 815         if (ins == &fn->leaf)
 816                 fn->rr_ptr = NULL;
 817
 818         /* Link this route to others same route. */
 819         if (rt->rt6i_nsiblings) {
 820                 unsigned int rt6i_nsiblings;
 821                 struct rt6_info *sibling, *temp_sibling;
 822
 823                 /* Find the first route that have the same metric */
 824                 sibling = fn->leaf;
 825                 while (sibling) {
 826                         if (sibling->rt6i_metric == rt->rt6i_metric &&
 827                             rt6_qualify_for_ecmp(sibling)) {
 828                                 list_add_tail(&rt->rt6i_siblings,
 829                                               &sibling->rt6i_siblings);
 830                                 break;
 831                         }
 832                         sibling = sibling->dst.rt6_next;
 833                 }
 834                 /* For each sibling in the list, increment the counter of
 835                  * siblings. BUG() if counters does not match, list of siblings
 836                  * is broken!
 837                  */
 838                 rt6i_nsiblings = 0;
 839                 list_for_each_entry_safe(sibling, temp_sibling,
 840                                          &rt->rt6i_siblings, rt6i_siblings) {
 841                         sibling->rt6i_nsiblings++;
 842                         BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
 843                         rt6i_nsiblings++;
 844                 }
 845                 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
 846         }
 847
 848         /*
 849          *      insert node
 850          */
 851         if (!replace) {
 852                 if (!add)
 853                         pr_warn("NLM_F_CREATE should be set when creating new route\n");
 854
 855 add:
 856                 err = fib6_commit_metrics(&rt->dst, mxc);
 857                 if (err)
 858                         return err;
 859
 860                 rt->dst.rt6_next = iter;
 861                 *ins = rt;
 862                 rt->rt6i_node = fn;
 863                 atomic_inc(&rt->rt6i_ref);
 864                 inet6_rt_notify(RTM_NEWROUTE, rt, info, 0);
 865                 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
 866
 867                 if (!(fn->fn_flags & RTN_RTINFO)) {
 868                         info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
 869                         fn->fn_flags |= RTN_RTINFO;
 870                 }
 871
 872         } else {
 873                 int nsiblings;
 874
 875                 if (!found) {
 876                         if (add)
 877                                 goto add;
 878                         pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
 879                         return -ENOENT;
 880                 }
 881
 882                 err = fib6_commit_metrics(&rt->dst, mxc);
 883                 if (err)
 884                         return err;
 885
 886                 *ins = rt;
 887                 rt->rt6i_node = fn;
 888                 rt->dst.rt6_next = iter->dst.rt6_next;
 889                 atomic_inc(&rt->rt6i_ref);
 890                 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
 891                 if (!(fn->fn_flags & RTN_RTINFO)) {
 892                         info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
 893                         fn->fn_flags |= RTN_RTINFO;
 894                 }
 895                 nsiblings = iter->rt6i_nsiblings;
 896                 fib6_purge_rt(iter, fn, info->nl_net);
 897                 rt6_release(iter);
 898
 899                 if (nsiblings) {
 900                         /* Replacing an ECMP route, remove all siblings */
 901                         ins = &rt->dst.rt6_next;
 902                         iter = *ins;
 903                         while (iter) {
 904                                 if (rt6_qualify_for_ecmp(iter)) {
 905                                         *ins = iter->dst.rt6_next;
 906                                         fib6_purge_rt(iter, fn, info->nl_net);
 907                                         rt6_release(iter);
 908                                         nsiblings--;
 909                                 } else {
 910                                         ins = &iter->dst.rt6_next;
 911                                 }
 912                                 iter = *ins;
 913                         }
 914                         WARN_ON(nsiblings != 0);
 915                 }
 916         }
 917
 918         return 0;
 919 }
 920
 921 static void fib6_start_gc(struct net *net, struct rt6_info *rt)
 922 {
 923         if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
 924             (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
 925                 mod_timer(&net->ipv6.ip6_fib_timer,
 926                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 927 }
 928
 929 void fib6_force_start_gc(struct net *net)
 930 {
 931         if (!timer_pending(&net->ipv6.ip6_fib_timer))
 932                 mod_timer(&net->ipv6.ip6_fib_timer,
 933                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 934 }
 935
 936 /*
 937  *      Add routing information to the routing tree.
 938  *      <destination addr>/<source addr>
 939  *      with source addr info in sub-trees
 940  */
 941
 942 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
 943              struct nl_info *info, struct mx6_config *mxc)
 944 {
 945         struct fib6_node *fn, *pn = NULL;
 946         int err = -ENOMEM;
 947         int allow_create = 1;
 948         int replace_required = 0;
 949         int sernum = fib6_new_sernum(info->nl_net);
 950
 951         if (WARN_ON_ONCE((rt->dst.flags & DST_NOCACHE) &&
 952                          !atomic_read(&rt->dst.__refcnt)))
 953                 return -EINVAL;
 954
 955         if (info->nlh) {
 956                 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
 957                         allow_create = 0;
 958                 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
 959                         replace_required = 1;
 960         }
 961         if (!allow_create && !replace_required)
 962                 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
 963
 964         fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 965                         offsetof(struct rt6_info, rt6i_dst), allow_create,
 966                         replace_required, sernum);
 967         if (IS_ERR(fn)) {
 968                 err = PTR_ERR(fn);
 969                 fn = NULL;
 970                 goto out;
 971         }
 972
 973         pn = fn;
 974
 975 #ifdef CONFIG_IPV6_SUBTREES
 976         if (rt->rt6i_src.plen) {
 977                 struct fib6_node *sn;
 978
 979                 if (!fn->subtree) {
 980                         struct fib6_node *sfn;
 981
 982                         /*
 983                          * Create subtree.
 984                          *
 985                          *              fn[main tree]
 986                          *              |
 987                          *              sfn[subtree root]
 988                          *                 \
 989                          *                  sn[new leaf node]
 990                          */
 991
 992                         /* Create subtree root node */
 993                         sfn = node_alloc();
 994                         if (!sfn)
 995                                 goto st_failure;
 996
 997                         sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
 998                         atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
 999                         sfn->fn_flags = RTN_ROOT;
1000                         sfn->fn_sernum = sernum;
1001
1002                         /* Now add the first leaf node to new subtree */
1003
1004                         sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
1005                                         rt->rt6i_src.plen,
1006                                         offsetof(struct rt6_info, rt6i_src),
1007                                         allow_create, replace_required, sernum);
1008
1009                         if (IS_ERR(sn)) {
1010                                 /* If it is failed, discard just allocated
1011                                    root, and then (in st_failure) stale node
1012                                    in main tree.
1013                                  */
1014                                 node_free(sfn);
1015                                 err = PTR_ERR(sn);
1016                                 goto st_failure;
1017                         }
1018
1019                         /* Now link new subtree to main tree */
1020                         sfn->parent = fn;
1021                         fn->subtree = sfn;
1022                 } else {
1023                         sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
1024                                         rt->rt6i_src.plen,
1025                                         offsetof(struct rt6_info, rt6i_src),
1026                                         allow_create, replace_required, sernum);
1027
1028                         if (IS_ERR(sn)) {
1029                                 err = PTR_ERR(sn);
1030                                 goto st_failure;
1031                         }
1032                 }
1033
1034                 if (!fn->leaf) {
1035                         fn->leaf = rt;
1036                         atomic_inc(&rt->rt6i_ref);
1037                 }
1038                 fn = sn;
1039         }
1040 #endif
1041
1042         err = fib6_add_rt2node(fn, rt, info, mxc);
1043         if (!err) {
1044                 fib6_start_gc(info->nl_net, rt);
1045                 if (!(rt->rt6i_flags & RTF_CACHE))
1046                         fib6_prune_clones(info->nl_net, pn);
1047                 rt->dst.flags &= ~DST_NOCACHE;
1048         }
1049
1050 out:
1051         if (err) {
1052 #ifdef CONFIG_IPV6_SUBTREES
1053                 /*
1054                  * If fib6_add_1 has cleared the old leaf pointer in the
1055                  * super-tree leaf node we have to find a new one for it.
1056                  */
1057                 if (pn != fn && pn->leaf == rt) {
1058                         pn->leaf = NULL;
1059                         atomic_dec(&rt->rt6i_ref);
1060                 }
1061                 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
1062                         pn->leaf = fib6_find_prefix(info->nl_net, pn);
1063 #if RT6_DEBUG >= 2
1064                         if (!pn->leaf) {
1065                                 WARN_ON(pn->leaf == NULL);
1066                                 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
1067                         }
1068 #endif
1069                         atomic_inc(&pn->leaf->rt6i_ref);
1070                 }
1071 #endif
1072                 if (!(rt->dst.flags & DST_NOCACHE))
1073                         dst_free(&rt->dst);
1074         }
1075         return err;
1076
1077 #ifdef CONFIG_IPV6_SUBTREES
1078         /* Subtree creation failed, probably main tree node
1079            is orphan. If it is, shoot it.
1080          */
1081 st_failure:
1082         if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
1083                 fib6_repair_tree(info->nl_net, fn);
1084         if (!(rt->dst.flags & DST_NOCACHE))
1085                 dst_free(&rt->dst);
1086         return err;
1087 #endif
1088 }
1089
1090 /*
1091  *      Routing tree lookup
1092  *
1093  */
1094
1095 struct lookup_args {
1096         int                     offset;         /* key offset on rt6_info       */
1097         const struct in6_addr   *addr;          /* search key                   */
1098 };
1099
1100 static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
1101                                        struct lookup_args *args)
1102 {
1103         struct fib6_node *fn;
1104         __be32 dir;
1105
1106         if (unlikely(args->offset == 0))
1107                 return NULL;
1108
1109         /*
1110          *      Descend on a tree
1111          */
1112
1113         fn = root;
1114
1115         for (;;) {
1116                 struct fib6_node *next;
1117
1118                 dir = addr_bit_set(args->addr, fn->fn_bit);
1119
1120                 next = dir ? fn->right : fn->left;
1121
1122                 if (next) {
1123                         fn = next;
1124                         continue;
1125                 }
1126                 break;
1127         }
1128
1129         while (fn) {
1130                 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
1131                         struct rt6key *key;
1132
1133                         key = (struct rt6key *) ((u8 *) fn->leaf +
1134                                                  args->offset);
1135
1136                         if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1137 #ifdef CONFIG_IPV6_SUBTREES
1138                                 if (fn->subtree) {
1139                                         struct fib6_node *sfn;
1140                                         sfn = fib6_lookup_1(fn->subtree,
1141                                                             args + 1);
1142                                         if (!sfn)
1143                                                 goto backtrack;
1144                                         fn = sfn;
1145                                 }
1146 #endif
1147                                 if (fn->fn_flags & RTN_RTINFO)
1148                                         return fn;
1149                         }
1150                 }
1151 #ifdef CONFIG_IPV6_SUBTREES
1152 backtrack:
1153 #endif
1154                 if (fn->fn_flags & RTN_ROOT)
1155                         break;
1156
1157                 fn = fn->parent;
1158         }
1159
1160         return NULL;
1161 }
1162
1163 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1164                               const struct in6_addr *saddr)
1165 {
1166         struct fib6_node *fn;
1167         struct lookup_args args[] = {
1168                 {
1169                         .offset = offsetof(struct rt6_info, rt6i_dst),
1170                         .addr = daddr,
1171                 },
1172 #ifdef CONFIG_IPV6_SUBTREES
1173                 {
1174                         .offset = offsetof(struct rt6_info, rt6i_src),
1175                         .addr = saddr,
1176                 },
1177 #endif
1178                 {
1179                         .offset = 0,    /* sentinel */
1180                 }
1181         };
1182
1183         fn = fib6_lookup_1(root, daddr ? args : args + 1);
1184         if (!fn || fn->fn_flags & RTN_TL_ROOT)
1185                 fn = root;
1186
1187         return fn;
1188 }
1189
1190 /*
1191  *      Get node with specified destination prefix (and source prefix,
1192  *      if subtrees are used)
1193  */
1194
1195
1196 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1197                                        const struct in6_addr *addr,
1198                                        int plen, int offset)
1199 {
1200         struct fib6_node *fn;
1201
1202         for (fn = root; fn ; ) {
1203                 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
1204
1205                 /*
1206                  *      Prefix match
1207                  */
1208                 if (plen < fn->fn_bit ||
1209                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1210                         return NULL;
1211
1212                 if (plen == fn->fn_bit)
1213                         return fn;
1214
1215                 /*
1216                  *      We have more bits to go
1217                  */
1218                 if (addr_bit_set(addr, fn->fn_bit))
1219                         fn = fn->right;
1220                 else
1221                         fn = fn->left;
1222         }
1223         return NULL;
1224 }
1225
1226 struct fib6_node *fib6_locate(struct fib6_node *root,
1227                               const struct in6_addr *daddr, int dst_len,
1228                               const struct in6_addr *saddr, int src_len)
1229 {
1230         struct fib6_node *fn;
1231
1232         fn = fib6_locate_1(root, daddr, dst_len,
1233                            offsetof(struct rt6_info, rt6i_dst));
1234
1235 #ifdef CONFIG_IPV6_SUBTREES
1236         if (src_len) {
1237                 WARN_ON(saddr == NULL);
1238                 if (fn && fn->subtree)
1239                         fn = fib6_locate_1(fn->subtree, saddr, src_len,
1240                                            offsetof(struct rt6_info, rt6i_src));
1241         }
1242 #endif
1243
1244         if (fn && fn->fn_flags & RTN_RTINFO)
1245                 return fn;
1246
1247         return NULL;
1248 }
1249
1250
1251 /*
1252  *      Deletion
1253  *
1254  */
1255
1256 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
1257 {
1258         if (fn->fn_flags & RTN_ROOT)
1259                 return net->ipv6.ip6_null_entry;
1260
1261         while (fn) {
1262                 if (fn->left)
1263                         return fn->left->leaf;
1264                 if (fn->right)
1265                         return fn->right->leaf;
1266
1267                 fn = FIB6_SUBTREE(fn);
1268         }
1269         return NULL;
1270 }
1271
1272 /*
1273  *      Called to trim the tree of intermediate nodes when possible. "fn"
1274  *      is the node we want to try and remove.
1275  */
1276
1277 static struct fib6_node *fib6_repair_tree(struct net *net,
1278                                            struct fib6_node *fn)
1279 {
1280         int children;
1281         int nstate;
1282         struct fib6_node *child, *pn;
1283         struct fib6_walker *w;
1284         int iter = 0;
1285
1286         for (;;) {
1287                 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1288                 iter++;
1289
1290                 WARN_ON(fn->fn_flags & RTN_RTINFO);
1291                 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1292                 WARN_ON(fn->leaf);
1293
1294                 children = 0;
1295                 child = NULL;
1296                 if (fn->right)
1297                         child = fn->right, children |= 1;
1298                 if (fn->left)
1299                         child = fn->left, children |= 2;
1300
1301                 if (children == 3 || FIB6_SUBTREE(fn)
1302 #ifdef CONFIG_IPV6_SUBTREES
1303                     /* Subtree root (i.e. fn) may have one child */
1304                     || (children && fn->fn_flags & RTN_ROOT)
1305 #endif
1306                     ) {
1307                         fn->leaf = fib6_find_prefix(net, fn);
1308 #if RT6_DEBUG >= 2
1309                         if (!fn->leaf) {
1310                                 WARN_ON(!fn->leaf);
1311                                 fn->leaf = net->ipv6.ip6_null_entry;
1312                         }
1313 #endif
1314                         atomic_inc(&fn->leaf->rt6i_ref);
1315                         return fn->parent;
1316                 }
1317
1318                 pn = fn->parent;
1319 #ifdef CONFIG_IPV6_SUBTREES
1320                 if (FIB6_SUBTREE(pn) == fn) {
1321                         WARN_ON(!(fn->fn_flags & RTN_ROOT));
1322                         FIB6_SUBTREE(pn) = NULL;
1323                         nstate = FWS_L;
1324                 } else {
1325                         WARN_ON(fn->fn_flags & RTN_ROOT);
1326 #endif
1327                         if (pn->right == fn)
1328                                 pn->right = child;
1329                         else if (pn->left == fn)
1330                                 pn->left = child;
1331 #if RT6_DEBUG >= 2
1332                         else
1333                                 WARN_ON(1);
1334 #endif
1335                         if (child)
1336                                 child->parent = pn;
1337                         nstate = FWS_R;
1338 #ifdef CONFIG_IPV6_SUBTREES
1339                 }
1340 #endif
1341
1342                 read_lock(&fib6_walker_lock);
1343                 FOR_WALKERS(w) {
1344                         if (!child) {
1345                                 if (w->root == fn) {
1346                                         w->root = w->node = NULL;
1347                                         RT6_TRACE("W %p adjusted by delroot 1\n", w);
1348                                 } else if (w->node == fn) {
1349                                         RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1350                                         w->node = pn;
1351                                         w->state = nstate;
1352                                 }
1353                         } else {
1354                                 if (w->root == fn) {
1355                                         w->root = child;
1356                                         RT6_TRACE("W %p adjusted by delroot 2\n", w);
1357                                 }
1358                                 if (w->node == fn) {
1359                                         w->node = child;
1360                                         if (children&2) {
1361                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1362                                                 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1363                                         } else {
1364                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1365                                                 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1366                                         }
1367                                 }
1368                         }
1369                 }
1370                 read_unlock(&fib6_walker_lock);
1371
1372                 node_free(fn);
1373                 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1374                         return pn;
1375
1376                 rt6_release(pn->leaf);
1377                 pn->leaf = NULL;
1378                 fn = pn;
1379         }
1380 }
1381
1382 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1383                            struct nl_info *info)
1384 {
1385         struct fib6_walker *w;
1386         struct rt6_info *rt = *rtp;
1387         struct net *net = info->nl_net;
1388
1389         RT6_TRACE("fib6_del_route\n");
1390
1391         /* Unlink it */
1392         *rtp = rt->dst.rt6_next;
1393         rt->rt6i_node = NULL;
1394         net->ipv6.rt6_stats->fib_rt_entries--;
1395         net->ipv6.rt6_stats->fib_discarded_routes++;
1396
1397         /* Reset round-robin state, if necessary */
1398         if (fn->rr_ptr == rt)
1399                 fn->rr_ptr = NULL;
1400
1401         /* Remove this entry from other siblings */
1402         if (rt->rt6i_nsiblings) {
1403                 struct rt6_info *sibling, *next_sibling;
1404
1405                 list_for_each_entry_safe(sibling, next_sibling,
1406                                          &rt->rt6i_siblings, rt6i_siblings)
1407                         sibling->rt6i_nsiblings--;
1408                 rt->rt6i_nsiblings = 0;
1409                 list_del_init(&rt->rt6i_siblings);
1410         }
1411
1412         /* Adjust walkers */
1413         read_lock(&fib6_walker_lock);
1414         FOR_WALKERS(w) {
1415                 if (w->state == FWS_C && w->leaf == rt) {
1416                         RT6_TRACE("walker %p adjusted by delroute\n", w);
1417                         w->leaf = rt->dst.rt6_next;
1418                         if (!w->leaf)
1419                                 w->state = FWS_U;
1420                 }
1421         }
1422         read_unlock(&fib6_walker_lock);
1423
1424         rt->dst.rt6_next = NULL;
1425
1426         /* If it was last route, expunge its radix tree node */
1427         if (!fn->leaf) {
1428                 fn->fn_flags &= ~RTN_RTINFO;
1429                 net->ipv6.rt6_stats->fib_route_nodes--;
1430                 fn = fib6_repair_tree(net, fn);
1431         }
1432
1433         fib6_purge_rt(rt, fn, net);
1434
1435         inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1436         rt6_release(rt);
1437 }
1438
1439 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1440 {
1441         struct net *net = info->nl_net;
1442         struct fib6_node *fn = rt->rt6i_node;
1443         struct rt6_info **rtp;
1444
1445 #if RT6_DEBUG >= 2
1446         if (rt->dst.obsolete > 0) {
1447                 WARN_ON(fn);
1448                 return -ENOENT;
1449         }
1450 #endif
1451         if (!fn || rt == net->ipv6.ip6_null_entry)
1452                 return -ENOENT;
1453
1454         WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1455
1456         if (!(rt->rt6i_flags & RTF_CACHE)) {
1457                 struct fib6_node *pn = fn;
1458 #ifdef CONFIG_IPV6_SUBTREES
1459                 /* clones of this route might be in another subtree */
1460                 if (rt->rt6i_src.plen) {
1461                         while (!(pn->fn_flags & RTN_ROOT))
1462                                 pn = pn->parent;
1463                         pn = pn->parent;
1464                 }
1465 #endif
1466                 fib6_prune_clones(info->nl_net, pn);
1467         }
1468
1469         /*
1470          *      Walk the leaf entries looking for ourself
1471          */
1472
1473         for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1474                 if (*rtp == rt) {
1475                         fib6_del_route(fn, rtp, info);
1476                         return 0;
1477                 }
1478         }
1479         return -ENOENT;
1480 }
1481
1482 /*
1483  *      Tree traversal function.
1484  *
1485  *      Certainly, it is not interrupt safe.
1486  *      However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1487  *      It means, that we can modify tree during walking
1488  *      and use this function for garbage collection, clone pruning,
1489  *      cleaning tree when a device goes down etc. etc.
1490  *
1491  *      It guarantees that every node will be traversed,
1492  *      and that it will be traversed only once.
1493  *
1494  *      Callback function w->func may return:
1495  *      0 -> continue walking.
1496  *      positive value -> walking is suspended (used by tree dumps,
1497  *      and probably by gc, if it will be split to several slices)
1498  *      negative value -> terminate walking.
1499  *
1500  *      The function itself returns:
1501  *      0   -> walk is complete.
1502  *      >0  -> walk is incomplete (i.e. suspended)
1503  *      <0  -> walk is terminated by an error.
1504  */
1505
1506 static int fib6_walk_continue(struct fib6_walker *w)
1507 {
1508         struct fib6_node *fn, *pn;
1509
1510         for (;;) {
1511                 fn = w->node;
1512                 if (!fn)
1513                         return 0;
1514
1515                 if (w->prune && fn != w->root &&
1516                     fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
1517                         w->state = FWS_C;
1518                         w->leaf = fn->leaf;
1519                 }
1520                 switch (w->state) {
1521 #ifdef CONFIG_IPV6_SUBTREES
1522                 case FWS_S:
1523                         if (FIB6_SUBTREE(fn)) {
1524                                 w->node = FIB6_SUBTREE(fn);
1525                                 continue;
1526                         }
1527                         w->state = FWS_L;
1528 #endif
1529                 case FWS_L:
1530                         if (fn->left) {
1531                                 w->node = fn->left;
1532                                 w->state = FWS_INIT;
1533                                 continue;
1534                         }
1535                         w->state = FWS_R;
1536                 case FWS_R:
1537                         if (fn->right) {
1538                                 w->node = fn->right;
1539                                 w->state = FWS_INIT;
1540                                 continue;
1541                         }
1542                         w->state = FWS_C;
1543                         w->leaf = fn->leaf;
1544                 case FWS_C:
1545                         if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1546                                 int err;
1547
1548                                 if (w->skip) {
1549                                         w->skip--;
1550                                         goto skip;
1551                                 }
1552
1553                                 err = w->func(w);
1554                                 if (err)
1555                                         return err;
1556
1557                                 w->count++;
1558                                 continue;
1559                         }
1560 skip:
1561                         w->state = FWS_U;
1562                 case FWS_U:
1563                         if (fn == w->root)
1564                                 return 0;
1565                         pn = fn->parent;
1566                         w->node = pn;
1567 #ifdef CONFIG_IPV6_SUBTREES
1568                         if (FIB6_SUBTREE(pn) == fn) {
1569                                 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1570                                 w->state = FWS_L;
1571                                 continue;
1572                         }
1573 #endif
1574                         if (pn->left == fn) {
1575                                 w->state = FWS_R;
1576                                 continue;
1577                         }
1578                         if (pn->right == fn) {
1579                                 w->state = FWS_C;
1580                                 w->leaf = w->node->leaf;
1581                                 continue;
1582                         }
1583 #if RT6_DEBUG >= 2
1584                         WARN_ON(1);
1585 #endif
1586                 }
1587         }
1588 }
1589
1590 static int fib6_walk(struct fib6_walker *w)
1591 {
1592         int res;
1593
1594         w->state = FWS_INIT;
1595         w->node = w->root;
1596
1597         fib6_walker_link(w);
1598         res = fib6_walk_continue(w);
1599         if (res <= 0)
1600                 fib6_walker_unlink(w);
1601         return res;
1602 }
1603
1604 static int fib6_clean_node(struct fib6_walker *w)
1605 {
1606         int res;
1607         struct rt6_info *rt;
1608         struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1609         struct nl_info info = {
1610                 .nl_net = c->net,
1611         };
1612
1613         if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1614             w->node->fn_sernum != c->sernum)
1615                 w->node->fn_sernum = c->sernum;
1616
1617         if (!c->func) {
1618                 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1619                 w->leaf = NULL;
1620                 return 0;
1621         }
1622
1623         for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1624                 res = c->func(rt, c->arg);
1625                 if (res < 0) {
1626                         w->leaf = rt;
1627                         res = fib6_del(rt, &info);
1628                         if (res) {
1629 #if RT6_DEBUG >= 2
1630                                 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1631                                          __func__, rt, rt->rt6i_node, res);
1632 #endif
1633                                 continue;
1634                         }
1635                         return 0;
1636                 }
1637                 WARN_ON(res != 0);
1638         }
1639         w->leaf = rt;
1640         return 0;
1641 }
1642
1643 /*
1644  *      Convenient frontend to tree walker.
1645  *
1646  *      func is called on each route.
1647  *              It may return -1 -> delete this route.
1648  *                            0  -> continue walking
1649  *
1650  *      prune==1 -> only immediate children of node (certainly,
1651  *      ignoring pure split nodes) will be scanned.
1652  */
1653
1654 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1655                             int (*func)(struct rt6_info *, void *arg),
1656                             bool prune, int sernum, void *arg)
1657 {
1658         struct fib6_cleaner c;
1659
1660         c.w.root = root;
1661         c.w.func = fib6_clean_node;
1662         c.w.prune = prune;
1663         c.w.count = 0;
1664         c.w.skip = 0;
1665         c.func = func;
1666         c.sernum = sernum;
1667         c.arg = arg;
1668         c.net = net;
1669
1670         fib6_walk(&c.w);
1671 }
1672
1673 static void __fib6_clean_all(struct net *net,
1674                              int (*func)(struct rt6_info *, void *),
1675                              int sernum, void *arg)
1676 {
1677         struct fib6_table *table;
1678         struct hlist_head *head;
1679         unsigned int h;
1680
1681         rcu_read_lock();
1682         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1683                 head = &net->ipv6.fib_table_hash[h];
1684                 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1685                         write_lock_bh(&table->tb6_lock);
1686                         fib6_clean_tree(net, &table->tb6_root,
1687                                         func, false, sernum, arg);
1688                         write_unlock_bh(&table->tb6_lock);
1689                 }
1690         }
1691         rcu_read_unlock();
1692 }
1693
1694 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
1695                     void *arg)
1696 {
1697         __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
1698 }
1699
1700 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1701 {
1702         if (rt->rt6i_flags & RTF_CACHE) {
1703                 RT6_TRACE("pruning clone %p\n", rt);
1704                 return -1;
1705         }
1706
1707         return 0;
1708 }
1709
1710 static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
1711 {
1712         fib6_clean_tree(net, fn, fib6_prune_clone, true,
1713                         FIB6_NO_SERNUM_CHANGE, NULL);
1714 }
1715
1716 static void fib6_flush_trees(struct net *net)
1717 {
1718         int new_sernum = fib6_new_sernum(net);
1719
1720         __fib6_clean_all(net, NULL, new_sernum, NULL);
1721 }
1722
1723 /*
1724  *      Garbage collection
1725  */
1726
1727 static struct fib6_gc_args
1728 {
1729         int                     timeout;
1730         int                     more;
1731 } gc_args;
1732
1733 static int fib6_age(struct rt6_info *rt, void *arg)
1734 {
1735         unsigned long now = jiffies;
1736
1737         /*
1738          *      check addrconf expiration here.
1739          *      Routes are expired even if they are in use.
1740          *
1741          *      Also age clones. Note, that clones are aged out
1742          *      only if they are not in use now.
1743          */
1744
1745         if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
1746                 if (time_after(now, rt->dst.expires)) {
1747                         RT6_TRACE("expiring %p\n", rt);
1748                         return -1;
1749                 }
1750                 gc_args.more++;
1751         } else if (rt->rt6i_flags & RTF_CACHE) {
1752                 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1753                     time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1754                         RT6_TRACE("aging clone %p\n", rt);
1755                         return -1;
1756                 } else if (rt->rt6i_flags & RTF_GATEWAY) {
1757                         struct neighbour *neigh;
1758                         __u8 neigh_flags = 0;
1759
1760                         neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
1761                         if (neigh) {
1762                                 neigh_flags = neigh->flags;
1763                                 neigh_release(neigh);
1764                         }
1765                         if (!(neigh_flags & NTF_ROUTER)) {
1766                                 RT6_TRACE("purging route %p via non-router but gateway\n",
1767                                           rt);
1768                                 return -1;
1769                         }
1770                 }
1771                 gc_args.more++;
1772         }
1773
1774         return 0;
1775 }
1776
1777 static DEFINE_SPINLOCK(fib6_gc_lock);
1778
1779 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
1780 {
1781         unsigned long now;
1782
1783         if (force) {
1784                 spin_lock_bh(&fib6_gc_lock);
1785         } else if (!spin_trylock_bh(&fib6_gc_lock)) {
1786                 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1787                 return;
1788         }
1789         gc_args.timeout = expires ? (int)expires :
1790                           net->ipv6.sysctl.ip6_rt_gc_interval;
1791
1792         gc_args.more = icmp6_dst_gc();
1793
1794         fib6_clean_all(net, fib6_age, NULL);
1795         now = jiffies;
1796         net->ipv6.ip6_rt_last_gc = now;
1797
1798         if (gc_args.more)
1799                 mod_timer(&net->ipv6.ip6_fib_timer,
1800                           round_jiffies(now
1801                                         + net->ipv6.sysctl.ip6_rt_gc_interval));
1802         else
1803                 del_timer(&net->ipv6.ip6_fib_timer);
1804         spin_unlock_bh(&fib6_gc_lock);
1805 }
1806
1807 static void fib6_gc_timer_cb(unsigned long arg)
1808 {
1809         fib6_run_gc(0, (struct net *)arg, true);
1810 }
1811
1812 static int __net_init fib6_net_init(struct net *net)
1813 {
1814         size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1815
1816         setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1817
1818         net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1819         if (!net->ipv6.rt6_stats)
1820                 goto out_timer;
1821
1822         /* Avoid false sharing : Use at least a full cache line */
1823         size = max_t(size_t, size, L1_CACHE_BYTES);
1824
1825         net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1826         if (!net->ipv6.fib_table_hash)
1827                 goto out_rt6_stats;
1828
1829         net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1830                                           GFP_KERNEL);
1831         if (!net->ipv6.fib6_main_tbl)
1832                 goto out_fib_table_hash;
1833
1834         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1835         net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1836         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1837                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1838         inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
1839
1840 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1841         net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1842                                            GFP_KERNEL);
1843         if (!net->ipv6.fib6_local_tbl)
1844                 goto out_fib6_main_tbl;
1845         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1846         net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1847         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1848                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1849         inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
1850 #endif
1851         fib6_tables_init(net);
1852
1853         return 0;
1854
1855 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1856 out_fib6_main_tbl:
1857         kfree(net->ipv6.fib6_main_tbl);
1858 #endif
1859 out_fib_table_hash:
1860         kfree(net->ipv6.fib_table_hash);
1861 out_rt6_stats:
1862         kfree(net->ipv6.rt6_stats);
1863 out_timer:
1864         return -ENOMEM;
1865 }
1866
1867 static void fib6_net_exit(struct net *net)
1868 {
1869         rt6_ifdown(net, NULL);
1870         del_timer_sync(&net->ipv6.ip6_fib_timer);
1871
1872 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1873         inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
1874         kfree(net->ipv6.fib6_local_tbl);
1875 #endif
1876         inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
1877         kfree(net->ipv6.fib6_main_tbl);
1878         kfree(net->ipv6.fib_table_hash);
1879         kfree(net->ipv6.rt6_stats);
1880 }
1881
1882 static struct pernet_operations fib6_net_ops = {
1883         .init = fib6_net_init,
1884         .exit = fib6_net_exit,
1885 };
1886
1887 int __init fib6_init(void)
1888 {
1889         int ret = -ENOMEM;
1890
1891         fib6_node_kmem = kmem_cache_create("fib6_nodes",
1892                                            sizeof(struct fib6_node),
1893                                            0, SLAB_HWCACHE_ALIGN,
1894                                            NULL);
1895         if (!fib6_node_kmem)
1896                 goto out;
1897
1898         ret = register_pernet_subsys(&fib6_net_ops);
1899         if (ret)
1900                 goto out_kmem_cache_create;
1901
1902         ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1903                               NULL);
1904         if (ret)
1905                 goto out_unregister_subsys;
1906
1907         __fib6_flush_trees = fib6_flush_trees;
1908 out:
1909         return ret;
1910
1911 out_unregister_subsys:
1912         unregister_pernet_subsys(&fib6_net_ops);
1913 out_kmem_cache_create:
1914         kmem_cache_destroy(fib6_node_kmem);
1915         goto out;
1916 }
1917
1918 void fib6_gc_cleanup(void)
1919 {
1920         unregister_pernet_subsys(&fib6_net_ops);
1921         kmem_cache_destroy(fib6_node_kmem);
1922 }
1923
1924 #ifdef CONFIG_PROC_FS
1925
1926 struct ipv6_route_iter {
1927         struct seq_net_private p;
1928         struct fib6_walker w;
1929         loff_t skip;
1930         struct fib6_table *tbl;
1931         int sernum;
1932 };
1933
1934 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
1935 {
1936         struct rt6_info *rt = v;
1937         struct ipv6_route_iter *iter = seq->private;
1938
1939         seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
1940
1941 #ifdef CONFIG_IPV6_SUBTREES
1942         seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
1943 #else
1944         seq_puts(seq, "00000000000000000000000000000000 00 ");
1945 #endif
1946         if (rt->rt6i_flags & RTF_GATEWAY)
1947                 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
1948         else
1949                 seq_puts(seq, "00000000000000000000000000000000");
1950
1951         seq_printf(seq, " %08x %08x %08x %08x %8s\n",
1952                    rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
1953                    rt->dst.__use, rt->rt6i_flags,
1954                    rt->dst.dev ? rt->dst.dev->name : "");
1955         iter->w.leaf = NULL;
1956         return 0;
1957 }
1958
1959 static int ipv6_route_yield(struct fib6_walker *w)
1960 {
1961         struct ipv6_route_iter *iter = w->args;
1962
1963         if (!iter->skip)
1964                 return 1;
1965
1966         do {
1967                 iter->w.leaf = iter->w.leaf->dst.rt6_next;
1968                 iter->skip--;
1969                 if (!iter->skip && iter->w.leaf)
1970                         return 1;
1971         } while (iter->w.leaf);
1972
1973         return 0;
1974 }
1975
1976 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter)
1977 {
1978         memset(&iter->w, 0, sizeof(iter->w));
1979         iter->w.func = ipv6_route_yield;
1980         iter->w.root = &iter->tbl->tb6_root;
1981         iter->w.state = FWS_INIT;
1982         iter->w.node = iter->w.root;
1983         iter->w.args = iter;
1984         iter->sernum = iter->w.root->fn_sernum;
1985         INIT_LIST_HEAD(&iter->w.lh);
1986         fib6_walker_link(&iter->w);
1987 }
1988
1989 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
1990                                                     struct net *net)
1991 {
1992         unsigned int h;
1993         struct hlist_node *node;
1994
1995         if (tbl) {
1996                 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
1997                 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
1998         } else {
1999                 h = 0;
2000                 node = NULL;
2001         }
2002
2003         while (!node && h < FIB6_TABLE_HASHSZ) {
2004                 node = rcu_dereference_bh(
2005                         hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2006         }
2007         return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2008 }
2009
2010 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2011 {
2012         if (iter->sernum != iter->w.root->fn_sernum) {
2013                 iter->sernum = iter->w.root->fn_sernum;
2014                 iter->w.state = FWS_INIT;
2015                 iter->w.node = iter->w.root;
2016                 WARN_ON(iter->w.skip);
2017                 iter->w.skip = iter->w.count;
2018         }
2019 }
2020
2021 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2022 {
2023         int r;
2024         struct rt6_info *n;
2025         struct net *net = seq_file_net(seq);
2026         struct ipv6_route_iter *iter = seq->private;
2027
2028         if (!v)
2029                 goto iter_table;
2030
2031         n = ((struct rt6_info *)v)->dst.rt6_next;
2032         if (n) {
2033                 ++*pos;
2034                 return n;
2035         }
2036
2037 iter_table:
2038         ipv6_route_check_sernum(iter);
2039         read_lock(&iter->tbl->tb6_lock);
2040         r = fib6_walk_continue(&iter->w);
2041         read_unlock(&iter->tbl->tb6_lock);
2042         if (r > 0) {
2043                 if (v)
2044                         ++*pos;
2045                 return iter->w.leaf;
2046         } else if (r < 0) {
2047                 fib6_walker_unlink(&iter->w);
2048                 return NULL;
2049         }
2050         fib6_walker_unlink(&iter->w);
2051
2052         iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2053         if (!iter->tbl)
2054                 return NULL;
2055
2056         ipv6_route_seq_setup_walk(iter);
2057         goto iter_table;
2058 }
2059
2060 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2061         __acquires(RCU_BH)
2062 {
2063         struct net *net = seq_file_net(seq);
2064         struct ipv6_route_iter *iter = seq->private;
2065
2066         rcu_read_lock_bh();
2067         iter->tbl = ipv6_route_seq_next_table(NULL, net);
2068         iter->skip = *pos;
2069
2070         if (iter->tbl) {
2071                 ipv6_route_seq_setup_walk(iter);
2072                 return ipv6_route_seq_next(seq, NULL, pos);
2073         } else {
2074                 return NULL;
2075         }
2076 }
2077
2078 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2079 {
2080         struct fib6_walker *w = &iter->w;
2081         return w->node && !(w->state == FWS_U && w->node == w->root);
2082 }
2083
2084 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2085         __releases(RCU_BH)
2086 {
2087         struct ipv6_route_iter *iter = seq->private;
2088
2089         if (ipv6_route_iter_active(iter))
2090                 fib6_walker_unlink(&iter->w);
2091
2092         rcu_read_unlock_bh();
2093 }
2094
2095 static const struct seq_operations ipv6_route_seq_ops = {
2096         .start  = ipv6_route_seq_start,
2097         .next   = ipv6_route_seq_next,
2098         .stop   = ipv6_route_seq_stop,
2099         .show   = ipv6_route_seq_show
2100 };
2101
2102 int ipv6_route_open(struct inode *inode, struct file *file)
2103 {
2104         return seq_open_net(inode, file, &ipv6_route_seq_ops,
2105                             sizeof(struct ipv6_route_iter));
2106 }
2107
2108 #endif /* CONFIG_PROC_FS */