SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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
  14 /*
  15  *      Changes:
  16  *      Yuji SEKIYA @USAGI:     Support default route on router node;
  17  *                              remove ip6_null_entry from the top of
  18  *                              routing table.
  19  *      Ville Nuorvala:         Fixed routing subtrees.
  20  */
  21 #include <linux/errno.h>
  22 #include <linux/types.h>
  23 #include <linux/net.h>
  24 #include <linux/route.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/in6.h>
  27 #include <linux/init.h>
  28 #include <linux/list.h>
  29
  30 #ifdef  CONFIG_PROC_FS
  31 #include <linux/proc_fs.h>
  32 #endif
  33
  34 #include <net/ipv6.h>
  35 #include <net/ndisc.h>
  36 #include <net/addrconf.h>
  37
  38 #include <net/ip6_fib.h>
  39 #include <net/ip6_route.h>
  40
  41 #define RT6_DEBUG 2
  42
  43 #if RT6_DEBUG >= 3
  44 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
  45 #else
  46 #define RT6_TRACE(x...) do { ; } while (0)
  47 #endif
  48
  49 static struct kmem_cache * fib6_node_kmem __read_mostly;
  50
  51 enum fib_walk_state_t
  52 {
  53 #ifdef CONFIG_IPV6_SUBTREES
  54         FWS_S,
  55 #endif
  56         FWS_L,
  57         FWS_R,
  58         FWS_C,
  59         FWS_U
  60 };
  61
  62 struct fib6_cleaner_t
  63 {
  64         struct fib6_walker_t w;
  65         struct net *net;
  66         int (*func)(struct rt6_info *, void *arg);
  67         void *arg;
  68 };
  69
  70 static DEFINE_RWLOCK(fib6_walker_lock);
  71
  72 #ifdef CONFIG_IPV6_SUBTREES
  73 #define FWS_INIT FWS_S
  74 #else
  75 #define FWS_INIT FWS_L
  76 #endif
  77
  78 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
  79                               struct rt6_info *rt);
  80 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
  81 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
  82 static int fib6_walk(struct fib6_walker_t *w);
  83 static int fib6_walk_continue(struct fib6_walker_t *w);
  84
  85 /*
  86  *      A routing update causes an increase of the serial number on the
  87  *      affected subtree. This allows for cached routes to be asynchronously
  88  *      tested when modifications are made to the destination cache as a
  89  *      result of redirects, path MTU changes, etc.
  90  */
  91
  92 static __u32 rt_sernum;
  93
  94 static void fib6_gc_timer_cb(unsigned long arg);
  95
  96 static LIST_HEAD(fib6_walkers);
  97 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
  98
  99 static inline void fib6_walker_link(struct fib6_walker_t *w)
 100 {
 101         write_lock_bh(&fib6_walker_lock);
 102         list_add(&w->lh, &fib6_walkers);
 103         write_unlock_bh(&fib6_walker_lock);
 104 }
 105
 106 static inline void fib6_walker_unlink(struct fib6_walker_t *w)
 107 {
 108         write_lock_bh(&fib6_walker_lock);
 109         list_del(&w->lh);
 110         write_unlock_bh(&fib6_walker_lock);
 111 }
 112 static __inline__ u32 fib6_new_sernum(void)
 113 {
 114         u32 n = ++rt_sernum;
 115         if ((__s32)n <= 0)
 116                 rt_sernum = n = 1;
 117         return n;
 118 }
 119
 120 /*
 121  *      Auxiliary address test functions for the radix tree.
 122  *
 123  *      These assume a 32bit processor (although it will work on
 124  *      64bit processors)
 125  */
 126
 127 /*
 128  *      test bit
 129  */
 130
 131 static __inline__ __be32 addr_bit_set(void *token, int fn_bit)
 132 {
 133         __be32 *addr = token;
 134
 135         return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5];
 136 }
 137
 138 static __inline__ struct fib6_node * node_alloc(void)
 139 {
 140         struct fib6_node *fn;
 141
 142         fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
 143
 144         return fn;
 145 }
 146
 147 static __inline__ void node_free(struct fib6_node * fn)
 148 {
 149         kmem_cache_free(fib6_node_kmem, fn);
 150 }
 151
 152 static __inline__ void rt6_release(struct rt6_info *rt)
 153 {
 154         if (atomic_dec_and_test(&rt->rt6i_ref))
 155                 dst_free(&rt->u.dst);
 156 }
 157
 158 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 159 {
 160         unsigned int h;
 161
 162         /*
 163          * Initialize table lock at a single place to give lockdep a key,
 164          * tables aren't visible prior to being linked to the list.
 165          */
 166         rwlock_init(&tb->tb6_lock);
 167
 168         h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
 169
 170         /*
 171          * No protection necessary, this is the only list mutatation
 172          * operation, tables never disappear once they exist.
 173          */
 174         hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
 175 }
 176
 177 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 178
 179 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
 180 {
 181         struct fib6_table *table;
 182
 183         table = kzalloc(sizeof(*table), GFP_ATOMIC);
 184         if (table != NULL) {
 185                 table->tb6_id = id;
 186                 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
 187                 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
 188         }
 189
 190         return table;
 191 }
 192
 193 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 194 {
 195         struct fib6_table *tb;
 196
 197         if (id == 0)
 198                 id = RT6_TABLE_MAIN;
 199         tb = fib6_get_table(net, id);
 200         if (tb)
 201                 return tb;
 202
 203         tb = fib6_alloc_table(net, id);
 204         if (tb != NULL)
 205                 fib6_link_table(net, tb);
 206
 207         return tb;
 208 }
 209
 210 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 211 {
 212         struct fib6_table *tb;
 213         struct hlist_head *head;
 214         struct hlist_node *node;
 215         unsigned int h;
 216
 217         if (id == 0)
 218                 id = RT6_TABLE_MAIN;
 219         h = id & (FIB6_TABLE_HASHSZ - 1);
 220         rcu_read_lock();
 221         head = &net->ipv6.fib_table_hash[h];
 222         hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
 223                 if (tb->tb6_id == id) {
 224                         rcu_read_unlock();
 225                         return tb;
 226                 }
 227         }
 228         rcu_read_unlock();
 229
 230         return NULL;
 231 }
 232
 233 static void __net_init fib6_tables_init(struct net *net)
 234 {
 235         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 236         fib6_link_table(net, net->ipv6.fib6_local_tbl);
 237 }
 238 #else
 239
 240 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 241 {
 242         return fib6_get_table(net, id);
 243 }
 244
 245 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 246 {
 247           return net->ipv6.fib6_main_tbl;
 248 }
 249
 250 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
 251                                    int flags, pol_lookup_t lookup)
 252 {
 253         return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl, flags);
 254 }
 255
 256 static void __net_init fib6_tables_init(struct net *net)
 257 {
 258         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 259 }
 260
 261 #endif
 262
 263 static int fib6_dump_node(struct fib6_walker_t *w)
 264 {
 265         int res;
 266         struct rt6_info *rt;
 267
 268         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
 269                 res = rt6_dump_route(rt, w->args);
 270                 if (res < 0) {
 271                         /* Frame is full, suspend walking */
 272                         w->leaf = rt;
 273                         return 1;
 274                 }
 275                 WARN_ON(res == 0);
 276         }
 277         w->leaf = NULL;
 278         return 0;
 279 }
 280
 281 static void fib6_dump_end(struct netlink_callback *cb)
 282 {
 283         struct fib6_walker_t *w = (void*)cb->args[2];
 284
 285         if (w) {
 286                 if (cb->args[4]) {
 287                         cb->args[4] = 0;
 288                         fib6_walker_unlink(w);
 289                 }
 290                 cb->args[2] = 0;
 291                 kfree(w);
 292         }
 293         cb->done = (void*)cb->args[3];
 294         cb->args[1] = 3;
 295 }
 296
 297 static int fib6_dump_done(struct netlink_callback *cb)
 298 {
 299         fib6_dump_end(cb);
 300         return cb->done ? cb->done(cb) : 0;
 301 }
 302
 303 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 304                            struct netlink_callback *cb)
 305 {
 306         struct fib6_walker_t *w;
 307         int res;
 308
 309         w = (void *)cb->args[2];
 310         w->root = &table->tb6_root;
 311
 312         if (cb->args[4] == 0) {
 313                 w->count = 0;
 314                 w->skip = 0;
 315
 316                 read_lock_bh(&table->tb6_lock);
 317                 res = fib6_walk(w);
 318                 read_unlock_bh(&table->tb6_lock);
 319                 if (res > 0) {
 320                         cb->args[4] = 1;
 321                         cb->args[5] = w->root->fn_sernum;
 322                 }
 323         } else {
 324                 if (cb->args[5] != w->root->fn_sernum) {
 325                         /* Begin at the root if the tree changed */
 326                         cb->args[5] = w->root->fn_sernum;
 327                         w->state = FWS_INIT;
 328                         w->node = w->root;
 329                         w->skip = w->count;
 330                 } else
 331                         w->skip = 0;
 332
 333                 read_lock_bh(&table->tb6_lock);
 334                 res = fib6_walk_continue(w);
 335                 read_unlock_bh(&table->tb6_lock);
 336                 if (res <= 0) {
 337                         fib6_walker_unlink(w);
 338                         cb->args[4] = 0;
 339                 }
 340         }
 341
 342         return res;
 343 }
 344
 345 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 346 {
 347         struct net *net = sock_net(skb->sk);
 348         unsigned int h, s_h;
 349         unsigned int e = 0, s_e;
 350         struct rt6_rtnl_dump_arg arg;
 351         struct fib6_walker_t *w;
 352         struct fib6_table *tb;
 353         struct hlist_node *node;
 354         struct hlist_head *head;
 355         int res = 0;
 356
 357         s_h = cb->args[0];
 358         s_e = cb->args[1];
 359
 360         w = (void *)cb->args[2];
 361         if (w == NULL) {
 362                 /* New dump:
 363                  *
 364                  * 1. hook callback destructor.
 365                  */
 366                 cb->args[3] = (long)cb->done;
 367                 cb->done = fib6_dump_done;
 368
 369                 /*
 370                  * 2. allocate and initialize walker.
 371                  */
 372                 w = kzalloc(sizeof(*w), GFP_ATOMIC);
 373                 if (w == NULL)
 374                         return -ENOMEM;
 375                 w->func = fib6_dump_node;
 376                 cb->args[2] = (long)w;
 377         }
 378
 379         arg.skb = skb;
 380         arg.cb = cb;
 381         arg.net = net;
 382         w->args = &arg;
 383
 384         for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
 385                 e = 0;
 386                 head = &net->ipv6.fib_table_hash[h];
 387                 hlist_for_each_entry(tb, node, head, tb6_hlist) {
 388                         if (e < s_e)
 389                                 goto next;
 390                         res = fib6_dump_table(tb, skb, cb);
 391                         if (res != 0)
 392                                 goto out;
 393 next:
 394                         e++;
 395                 }
 396         }
 397 out:
 398         cb->args[1] = e;
 399         cb->args[0] = h;
 400
 401         res = res < 0 ? res : skb->len;
 402         if (res <= 0)
 403                 fib6_dump_end(cb);
 404         return res;
 405 }
 406
 407 /*
 408  *      Routing Table
 409  *
 410  *      return the appropriate node for a routing tree "add" operation
 411  *      by either creating and inserting or by returning an existing
 412  *      node.
 413  */
 414
 415 static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
 416                                      int addrlen, int plen,
 417                                      int offset)
 418 {
 419         struct fib6_node *fn, *in, *ln;
 420         struct fib6_node *pn = NULL;
 421         struct rt6key *key;
 422         int     bit;
 423         __be32  dir = 0;
 424         __u32   sernum = fib6_new_sernum();
 425
 426         RT6_TRACE("fib6_add_1\n");
 427
 428         /* insert node in tree */
 429
 430         fn = root;
 431
 432         do {
 433                 key = (struct rt6key *)((u8 *)fn->leaf + offset);
 434
 435                 /*
 436                  *      Prefix match
 437                  */
 438                 if (plen < fn->fn_bit ||
 439                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 440                         goto insert_above;
 441
 442                 /*
 443                  *      Exact match ?
 444                  */
 445
 446                 if (plen == fn->fn_bit) {
 447                         /* clean up an intermediate node */
 448                         if ((fn->fn_flags & RTN_RTINFO) == 0) {
 449                                 rt6_release(fn->leaf);
 450                                 fn->leaf = NULL;
 451                         }
 452
 453                         fn->fn_sernum = sernum;
 454
 455                         return fn;
 456                 }
 457
 458                 /*
 459                  *      We have more bits to go
 460                  */
 461
 462                 /* Try to walk down on tree. */
 463                 fn->fn_sernum = sernum;
 464                 dir = addr_bit_set(addr, fn->fn_bit);
 465                 pn = fn;
 466                 fn = dir ? fn->right: fn->left;
 467         } while (fn);
 468
 469         /*
 470          *      We walked to the bottom of tree.
 471          *      Create new leaf node without children.
 472          */
 473
 474         ln = node_alloc();
 475
 476         if (ln == NULL)
 477                 return NULL;
 478         ln->fn_bit = plen;
 479
 480         ln->parent = pn;
 481         ln->fn_sernum = sernum;
 482
 483         if (dir)
 484                 pn->right = ln;
 485         else
 486                 pn->left  = ln;
 487
 488         return ln;
 489
 490
 491 insert_above:
 492         /*
 493          * split since we don't have a common prefix anymore or
 494          * we have a less significant route.
 495          * we've to insert an intermediate node on the list
 496          * this new node will point to the one we need to create
 497          * and the current
 498          */
 499
 500         pn = fn->parent;
 501
 502         /* find 1st bit in difference between the 2 addrs.
 503
 504            See comment in __ipv6_addr_diff: bit may be an invalid value,
 505            but if it is >= plen, the value is ignored in any case.
 506          */
 507
 508         bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
 509
 510         /*
 511          *              (intermediate)[in]
 512          *                /        \
 513          *      (new leaf node)[ln] (old node)[fn]
 514          */
 515         if (plen > bit) {
 516                 in = node_alloc();
 517                 ln = node_alloc();
 518
 519                 if (in == NULL || ln == NULL) {
 520                         if (in)
 521                                 node_free(in);
 522                         if (ln)
 523                                 node_free(ln);
 524                         return NULL;
 525                 }
 526
 527                 /*
 528                  * new intermediate node.
 529                  * RTN_RTINFO will
 530                  * be off since that an address that chooses one of
 531                  * the branches would not match less specific routes
 532                  * in the other branch
 533                  */
 534
 535                 in->fn_bit = bit;
 536
 537                 in->parent = pn;
 538                 in->leaf = fn->leaf;
 539                 atomic_inc(&in->leaf->rt6i_ref);
 540
 541                 in->fn_sernum = sernum;
 542
 543                 /* update parent pointer */
 544                 if (dir)
 545                         pn->right = in;
 546                 else
 547                         pn->left  = in;
 548
 549                 ln->fn_bit = plen;
 550
 551                 ln->parent = in;
 552                 fn->parent = in;
 553
 554                 ln->fn_sernum = sernum;
 555
 556                 if (addr_bit_set(addr, bit)) {
 557                         in->right = ln;
 558                         in->left  = fn;
 559                 } else {
 560                         in->left  = ln;
 561                         in->right = fn;
 562                 }
 563         } else { /* plen <= bit */
 564
 565                 /*
 566                  *              (new leaf node)[ln]
 567                  *                /        \
 568                  *           (old node)[fn] NULL
 569                  */
 570
 571                 ln = node_alloc();
 572
 573                 if (ln == NULL)
 574                         return NULL;
 575
 576                 ln->fn_bit = plen;
 577
 578                 ln->parent = pn;
 579
 580                 ln->fn_sernum = sernum;
 581
 582                 if (dir)
 583                         pn->right = ln;
 584                 else
 585                         pn->left  = ln;
 586
 587                 if (addr_bit_set(&key->addr, plen))
 588                         ln->right = fn;
 589                 else
 590                         ln->left  = fn;
 591
 592                 fn->parent = ln;
 593         }
 594         return ln;
 595 }
 596
 597 /*
 598  *      Insert routing information in a node.
 599  */
 600
 601 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 602                             struct nl_info *info)
 603 {
 604         struct rt6_info *iter = NULL;
 605         struct rt6_info **ins;
 606
 607         ins = &fn->leaf;
 608
 609         for (iter = fn->leaf; iter; iter=iter->u.dst.rt6_next) {
 610                 /*
 611                  *      Search for duplicates
 612                  */
 613
 614                 if (iter->rt6i_metric == rt->rt6i_metric) {
 615                         /*
 616                          *      Same priority level
 617                          */
 618
 619                         if (iter->rt6i_dev == rt->rt6i_dev &&
 620                             iter->rt6i_idev == rt->rt6i_idev &&
 621                             ipv6_addr_equal(&iter->rt6i_gateway,
 622                                             &rt->rt6i_gateway)) {
 623                                 if (!(iter->rt6i_flags&RTF_EXPIRES))
 624                                         return -EEXIST;
 625                                 iter->rt6i_expires = rt->rt6i_expires;
 626                                 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
 627                                         iter->rt6i_flags &= ~RTF_EXPIRES;
 628                                         iter->rt6i_expires = 0;
 629                                 }
 630                                 return -EEXIST;
 631                         }
 632                 }
 633
 634                 if (iter->rt6i_metric > rt->rt6i_metric)
 635                         break;
 636
 637                 ins = &iter->u.dst.rt6_next;
 638         }
 639
 640         /* Reset round-robin state, if necessary */
 641         if (ins == &fn->leaf)
 642                 fn->rr_ptr = NULL;
 643
 644         /*
 645          *      insert node
 646          */
 647
 648         rt->u.dst.rt6_next = iter;
 649         *ins = rt;
 650         rt->rt6i_node = fn;
 651         atomic_inc(&rt->rt6i_ref);
 652         inet6_rt_notify(RTM_NEWROUTE, rt, info);
 653         info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
 654
 655         if ((fn->fn_flags & RTN_RTINFO) == 0) {
 656                 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
 657                 fn->fn_flags |= RTN_RTINFO;
 658         }
 659
 660         return 0;
 661 }
 662
 663 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
 664 {
 665         if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
 666             (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
 667                 mod_timer(&net->ipv6.ip6_fib_timer,
 668                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 669 }
 670
 671 void fib6_force_start_gc(struct net *net)
 672 {
 673         if (!timer_pending(&net->ipv6.ip6_fib_timer))
 674                 mod_timer(&net->ipv6.ip6_fib_timer,
 675                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 676 }
 677
 678 /*
 679  *      Add routing information to the routing tree.
 680  *      <destination addr>/<source addr>
 681  *      with source addr info in sub-trees
 682  */
 683
 684 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
 685 {
 686         struct fib6_node *fn, *pn = NULL;
 687         int err = -ENOMEM;
 688
 689         fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
 690                         rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
 691
 692         if (fn == NULL)
 693                 goto out;
 694
 695         pn = fn;
 696
 697 #ifdef CONFIG_IPV6_SUBTREES
 698         if (rt->rt6i_src.plen) {
 699                 struct fib6_node *sn;
 700
 701                 if (fn->subtree == NULL) {
 702                         struct fib6_node *sfn;
 703
 704                         /*
 705                          * Create subtree.
 706                          *
 707                          *              fn[main tree]
 708                          *              |
 709                          *              sfn[subtree root]
 710                          *                 \
 711                          *                  sn[new leaf node]
 712                          */
 713
 714                         /* Create subtree root node */
 715                         sfn = node_alloc();
 716                         if (sfn == NULL)
 717                                 goto st_failure;
 718
 719                         sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
 720                         atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
 721                         sfn->fn_flags = RTN_ROOT;
 722                         sfn->fn_sernum = fib6_new_sernum();
 723
 724                         /* Now add the first leaf node to new subtree */
 725
 726                         sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
 727                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
 728                                         offsetof(struct rt6_info, rt6i_src));
 729
 730                         if (sn == NULL) {
 731                                 /* If it is failed, discard just allocated
 732                                    root, and then (in st_failure) stale node
 733                                    in main tree.
 734                                  */
 735                                 node_free(sfn);
 736                                 goto st_failure;
 737                         }
 738
 739                         /* Now link new subtree to main tree */
 740                         sfn->parent = fn;
 741                         fn->subtree = sfn;
 742                 } else {
 743                         sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
 744                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
 745                                         offsetof(struct rt6_info, rt6i_src));
 746
 747                         if (sn == NULL)
 748                                 goto st_failure;
 749                 }
 750
 751                 if (fn->leaf == NULL) {
 752                         fn->leaf = rt;
 753                         atomic_inc(&rt->rt6i_ref);
 754                 }
 755                 fn = sn;
 756         }
 757 #endif
 758
 759         err = fib6_add_rt2node(fn, rt, info);
 760
 761         if (err == 0) {
 762                 fib6_start_gc(info->nl_net, rt);
 763                 if (!(rt->rt6i_flags&RTF_CACHE))
 764                         fib6_prune_clones(info->nl_net, pn, rt);
 765         }
 766
 767 out:
 768         if (err) {
 769 #ifdef CONFIG_IPV6_SUBTREES
 770                 /*
 771                  * If fib6_add_1 has cleared the old leaf pointer in the
 772                  * super-tree leaf node we have to find a new one for it.
 773                  */
 774                 if (pn != fn && pn->leaf == rt) {
 775                         pn->leaf = NULL;
 776                         atomic_dec(&rt->rt6i_ref);
 777                 }
 778                 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
 779                         pn->leaf = fib6_find_prefix(info->nl_net, pn);
 780 #if RT6_DEBUG >= 2
 781                         if (!pn->leaf) {
 782                                 WARN_ON(pn->leaf == NULL);
 783                                 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
 784                         }
 785 #endif
 786                         atomic_inc(&pn->leaf->rt6i_ref);
 787                 }
 788 #endif
 789                 dst_free(&rt->u.dst);
 790         }
 791         return err;
 792
 793 #ifdef CONFIG_IPV6_SUBTREES
 794         /* Subtree creation failed, probably main tree node
 795            is orphan. If it is, shoot it.
 796          */
 797 st_failure:
 798         if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
 799                 fib6_repair_tree(info->nl_net, fn);
 800         dst_free(&rt->u.dst);
 801         return err;
 802 #endif
 803 }
 804
 805 /*
 806  *      Routing tree lookup
 807  *
 808  */
 809
 810 struct lookup_args {
 811         int             offset;         /* key offset on rt6_info       */
 812         struct in6_addr *addr;          /* search key                   */
 813 };
 814
 815 static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
 816                                         struct lookup_args *args)
 817 {
 818         struct fib6_node *fn;
 819         __be32 dir;
 820
 821         if (unlikely(args->offset == 0))
 822                 return NULL;
 823
 824         /*
 825          *      Descend on a tree
 826          */
 827
 828         fn = root;
 829
 830         for (;;) {
 831                 struct fib6_node *next;
 832
 833                 dir = addr_bit_set(args->addr, fn->fn_bit);
 834
 835                 next = dir ? fn->right : fn->left;
 836
 837                 if (next) {
 838                         fn = next;
 839                         continue;
 840                 }
 841
 842                 break;
 843         }
 844
 845         while(fn) {
 846                 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
 847                         struct rt6key *key;
 848
 849                         key = (struct rt6key *) ((u8 *) fn->leaf +
 850                                                  args->offset);
 851
 852                         if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
 853 #ifdef CONFIG_IPV6_SUBTREES
 854                                 if (fn->subtree)
 855                                         fn = fib6_lookup_1(fn->subtree, args + 1);
 856 #endif
 857                                 if (!fn || fn->fn_flags & RTN_RTINFO)
 858                                         return fn;
 859                         }
 860                 }
 861
 862                 if (fn->fn_flags & RTN_ROOT)
 863                         break;
 864
 865                 fn = fn->parent;
 866         }
 867
 868         return NULL;
 869 }
 870
 871 struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr,
 872                                struct in6_addr *saddr)
 873 {
 874         struct fib6_node *fn;
 875         struct lookup_args args[] = {
 876                 {
 877                         .offset = offsetof(struct rt6_info, rt6i_dst),
 878                         .addr = daddr,
 879                 },
 880 #ifdef CONFIG_IPV6_SUBTREES
 881                 {
 882                         .offset = offsetof(struct rt6_info, rt6i_src),
 883                         .addr = saddr,
 884                 },
 885 #endif
 886                 {
 887                         .offset = 0,    /* sentinel */
 888                 }
 889         };
 890
 891         fn = fib6_lookup_1(root, daddr ? args : args + 1);
 892
 893         if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
 894                 fn = root;
 895
 896         return fn;
 897 }
 898
 899 /*
 900  *      Get node with specified destination prefix (and source prefix,
 901  *      if subtrees are used)
 902  */
 903
 904
 905 static struct fib6_node * fib6_locate_1(struct fib6_node *root,
 906                                         struct in6_addr *addr,
 907                                         int plen, int offset)
 908 {
 909         struct fib6_node *fn;
 910
 911         for (fn = root; fn ; ) {
 912                 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
 913
 914                 /*
 915                  *      Prefix match
 916                  */
 917                 if (plen < fn->fn_bit ||
 918                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 919                         return NULL;
 920
 921                 if (plen == fn->fn_bit)
 922                         return fn;
 923
 924                 /*
 925                  *      We have more bits to go
 926                  */
 927                 if (addr_bit_set(addr, fn->fn_bit))
 928                         fn = fn->right;
 929                 else
 930                         fn = fn->left;
 931         }
 932         return NULL;
 933 }
 934
 935 struct fib6_node * fib6_locate(struct fib6_node *root,
 936                                struct in6_addr *daddr, int dst_len,
 937                                struct in6_addr *saddr, int src_len)
 938 {
 939         struct fib6_node *fn;
 940
 941         fn = fib6_locate_1(root, daddr, dst_len,
 942                            offsetof(struct rt6_info, rt6i_dst));
 943
 944 #ifdef CONFIG_IPV6_SUBTREES
 945         if (src_len) {
 946                 WARN_ON(saddr == NULL);
 947                 if (fn && fn->subtree)
 948                         fn = fib6_locate_1(fn->subtree, saddr, src_len,
 949                                            offsetof(struct rt6_info, rt6i_src));
 950         }
 951 #endif
 952
 953         if (fn && fn->fn_flags&RTN_RTINFO)
 954                 return fn;
 955
 956         return NULL;
 957 }
 958
 959
 960 /*
 961  *      Deletion
 962  *
 963  */
 964
 965 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
 966 {
 967         if (fn->fn_flags&RTN_ROOT)
 968                 return net->ipv6.ip6_null_entry;
 969
 970         while(fn) {
 971                 if(fn->left)
 972                         return fn->left->leaf;
 973
 974                 if(fn->right)
 975                         return fn->right->leaf;
 976
 977                 fn = FIB6_SUBTREE(fn);
 978         }
 979         return NULL;
 980 }
 981
 982 /*
 983  *      Called to trim the tree of intermediate nodes when possible. "fn"
 984  *      is the node we want to try and remove.
 985  */
 986
 987 static struct fib6_node *fib6_repair_tree(struct net *net,
 988                                            struct fib6_node *fn)
 989 {
 990         int children;
 991         int nstate;
 992         struct fib6_node *child, *pn;
 993         struct fib6_walker_t *w;
 994         int iter = 0;
 995
 996         for (;;) {
 997                 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
 998                 iter++;
 999
1000                 WARN_ON(fn->fn_flags & RTN_RTINFO);
1001                 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1002                 WARN_ON(fn->leaf != NULL);
1003
1004                 children = 0;
1005                 child = NULL;
1006                 if (fn->right) child = fn->right, children |= 1;
1007                 if (fn->left) child = fn->left, children |= 2;
1008
1009                 if (children == 3 || FIB6_SUBTREE(fn)
1010 #ifdef CONFIG_IPV6_SUBTREES
1011                     /* Subtree root (i.e. fn) may have one child */
1012                     || (children && fn->fn_flags&RTN_ROOT)
1013 #endif
1014                     ) {
1015                         fn->leaf = fib6_find_prefix(net, fn);
1016 #if RT6_DEBUG >= 2
1017                         if (fn->leaf==NULL) {
1018                                 WARN_ON(!fn->leaf);
1019                                 fn->leaf = net->ipv6.ip6_null_entry;
1020                         }
1021 #endif
1022                         atomic_inc(&fn->leaf->rt6i_ref);
1023                         return fn->parent;
1024                 }
1025
1026                 pn = fn->parent;
1027 #ifdef CONFIG_IPV6_SUBTREES
1028                 if (FIB6_SUBTREE(pn) == fn) {
1029                         WARN_ON(!(fn->fn_flags & RTN_ROOT));
1030                         FIB6_SUBTREE(pn) = NULL;
1031                         nstate = FWS_L;
1032                 } else {
1033                         WARN_ON(fn->fn_flags & RTN_ROOT);
1034 #endif
1035                         if (pn->right == fn) pn->right = child;
1036                         else if (pn->left == fn) pn->left = child;
1037 #if RT6_DEBUG >= 2
1038                         else
1039                                 WARN_ON(1);
1040 #endif
1041                         if (child)
1042                                 child->parent = pn;
1043                         nstate = FWS_R;
1044 #ifdef CONFIG_IPV6_SUBTREES
1045                 }
1046 #endif
1047
1048                 read_lock(&fib6_walker_lock);
1049                 FOR_WALKERS(w) {
1050                         if (child == NULL) {
1051                                 if (w->root == fn) {
1052                                         w->root = w->node = NULL;
1053                                         RT6_TRACE("W %p adjusted by delroot 1\n", w);
1054                                 } else if (w->node == fn) {
1055                                         RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1056                                         w->node = pn;
1057                                         w->state = nstate;
1058                                 }
1059                         } else {
1060                                 if (w->root == fn) {
1061                                         w->root = child;
1062                                         RT6_TRACE("W %p adjusted by delroot 2\n", w);
1063                                 }
1064                                 if (w->node == fn) {
1065                                         w->node = child;
1066                                         if (children&2) {
1067                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1068                                                 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1069                                         } else {
1070                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1071                                                 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1072                                         }
1073                                 }
1074                         }
1075                 }
1076                 read_unlock(&fib6_walker_lock);
1077
1078                 node_free(fn);
1079                 if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn))
1080                         return pn;
1081
1082                 rt6_release(pn->leaf);
1083                 pn->leaf = NULL;
1084                 fn = pn;
1085         }
1086 }
1087
1088 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1089                            struct nl_info *info)
1090 {
1091         struct fib6_walker_t *w;
1092         struct rt6_info *rt = *rtp;
1093         struct net *net = info->nl_net;
1094
1095         RT6_TRACE("fib6_del_route\n");
1096
1097         /* Unlink it */
1098         *rtp = rt->u.dst.rt6_next;
1099         rt->rt6i_node = NULL;
1100         net->ipv6.rt6_stats->fib_rt_entries--;
1101         net->ipv6.rt6_stats->fib_discarded_routes++;
1102
1103         /* Reset round-robin state, if necessary */
1104         if (fn->rr_ptr == rt)
1105                 fn->rr_ptr = NULL;
1106
1107         /* Adjust walkers */
1108         read_lock(&fib6_walker_lock);
1109         FOR_WALKERS(w) {
1110                 if (w->state == FWS_C && w->leaf == rt) {
1111                         RT6_TRACE("walker %p adjusted by delroute\n", w);
1112                         w->leaf = rt->u.dst.rt6_next;
1113                         if (w->leaf == NULL)
1114                                 w->state = FWS_U;
1115                 }
1116         }
1117         read_unlock(&fib6_walker_lock);
1118
1119         rt->u.dst.rt6_next = NULL;
1120
1121         /* If it was last route, expunge its radix tree node */
1122         if (fn->leaf == NULL) {
1123                 fn->fn_flags &= ~RTN_RTINFO;
1124                 net->ipv6.rt6_stats->fib_route_nodes--;
1125                 fn = fib6_repair_tree(net, fn);
1126         }
1127
1128         if (atomic_read(&rt->rt6i_ref) != 1) {
1129                 /* This route is used as dummy address holder in some split
1130                  * nodes. It is not leaked, but it still holds other resources,
1131                  * which must be released in time. So, scan ascendant nodes
1132                  * and replace dummy references to this route with references
1133                  * to still alive ones.
1134                  */
1135                 while (fn) {
1136                         if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
1137                                 fn->leaf = fib6_find_prefix(net, fn);
1138                                 atomic_inc(&fn->leaf->rt6i_ref);
1139                                 rt6_release(rt);
1140                         }
1141                         fn = fn->parent;
1142                 }
1143                 /* No more references are possible at this point. */
1144                 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1145         }
1146
1147         inet6_rt_notify(RTM_DELROUTE, rt, info);
1148         rt6_release(rt);
1149 }
1150
1151 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1152 {
1153         struct net *net = info->nl_net;
1154         struct fib6_node *fn = rt->rt6i_node;
1155         struct rt6_info **rtp;
1156
1157 #if RT6_DEBUG >= 2
1158         if (rt->u.dst.obsolete>0) {
1159                 WARN_ON(fn != NULL);
1160                 return -ENOENT;
1161         }
1162 #endif
1163         if (fn == NULL || rt == net->ipv6.ip6_null_entry)
1164                 return -ENOENT;
1165
1166         WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1167
1168         if (!(rt->rt6i_flags&RTF_CACHE)) {
1169                 struct fib6_node *pn = fn;
1170 #ifdef CONFIG_IPV6_SUBTREES
1171                 /* clones of this route might be in another subtree */
1172                 if (rt->rt6i_src.plen) {
1173                         while (!(pn->fn_flags&RTN_ROOT))
1174                                 pn = pn->parent;
1175                         pn = pn->parent;
1176                 }
1177 #endif
1178                 fib6_prune_clones(info->nl_net, pn, rt);
1179         }
1180
1181         /*
1182          *      Walk the leaf entries looking for ourself
1183          */
1184
1185         for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.dst.rt6_next) {
1186                 if (*rtp == rt) {
1187                         fib6_del_route(fn, rtp, info);
1188                         return 0;
1189                 }
1190         }
1191         return -ENOENT;
1192 }
1193
1194 /*
1195  *      Tree traversal function.
1196  *
1197  *      Certainly, it is not interrupt safe.
1198  *      However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1199  *      It means, that we can modify tree during walking
1200  *      and use this function for garbage collection, clone pruning,
1201  *      cleaning tree when a device goes down etc. etc.
1202  *
1203  *      It guarantees that every node will be traversed,
1204  *      and that it will be traversed only once.
1205  *
1206  *      Callback function w->func may return:
1207  *      0 -> continue walking.
1208  *      positive value -> walking is suspended (used by tree dumps,
1209  *      and probably by gc, if it will be split to several slices)
1210  *      negative value -> terminate walking.
1211  *
1212  *      The function itself returns:
1213  *      0   -> walk is complete.
1214  *      >0  -> walk is incomplete (i.e. suspended)
1215  *      <0  -> walk is terminated by an error.
1216  */
1217
1218 static int fib6_walk_continue(struct fib6_walker_t *w)
1219 {
1220         struct fib6_node *fn, *pn;
1221
1222         for (;;) {
1223                 fn = w->node;
1224                 if (fn == NULL)
1225                         return 0;
1226
1227                 if (w->prune && fn != w->root &&
1228                     fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1229                         w->state = FWS_C;
1230                         w->leaf = fn->leaf;
1231                 }
1232                 switch (w->state) {
1233 #ifdef CONFIG_IPV6_SUBTREES
1234                 case FWS_S:
1235                         if (FIB6_SUBTREE(fn)) {
1236                                 w->node = FIB6_SUBTREE(fn);
1237                                 continue;
1238                         }
1239                         w->state = FWS_L;
1240 #endif
1241                 case FWS_L:
1242                         if (fn->left) {
1243                                 w->node = fn->left;
1244                                 w->state = FWS_INIT;
1245                                 continue;
1246                         }
1247                         w->state = FWS_R;
1248                 case FWS_R:
1249                         if (fn->right) {
1250                                 w->node = fn->right;
1251                                 w->state = FWS_INIT;
1252                                 continue;
1253                         }
1254                         w->state = FWS_C;
1255                         w->leaf = fn->leaf;
1256                 case FWS_C:
1257                         if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1258                                 int err;
1259
1260                                 if (w->count < w->skip) {
1261                                         w->count++;
1262                                         continue;
1263                                 }
1264
1265                                 err = w->func(w);
1266                                 if (err)
1267                                         return err;
1268
1269                                 w->count++;
1270                                 continue;
1271                         }
1272                         w->state = FWS_U;
1273                 case FWS_U:
1274                         if (fn == w->root)
1275                                 return 0;
1276                         pn = fn->parent;
1277                         w->node = pn;
1278 #ifdef CONFIG_IPV6_SUBTREES
1279                         if (FIB6_SUBTREE(pn) == fn) {
1280                                 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1281                                 w->state = FWS_L;
1282                                 continue;
1283                         }
1284 #endif
1285                         if (pn->left == fn) {
1286                                 w->state = FWS_R;
1287                                 continue;
1288                         }
1289                         if (pn->right == fn) {
1290                                 w->state = FWS_C;
1291                                 w->leaf = w->node->leaf;
1292                                 continue;
1293                         }
1294 #if RT6_DEBUG >= 2
1295                         WARN_ON(1);
1296 #endif
1297                 }
1298         }
1299 }
1300
1301 static int fib6_walk(struct fib6_walker_t *w)
1302 {
1303         int res;
1304
1305         w->state = FWS_INIT;
1306         w->node = w->root;
1307
1308         fib6_walker_link(w);
1309         res = fib6_walk_continue(w);
1310         if (res <= 0)
1311                 fib6_walker_unlink(w);
1312         return res;
1313 }
1314
1315 static int fib6_clean_node(struct fib6_walker_t *w)
1316 {
1317         int res;
1318         struct rt6_info *rt;
1319         struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1320         struct nl_info info = {
1321                 .nl_net = c->net,
1322         };
1323
1324         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
1325                 res = c->func(rt, c->arg);
1326                 if (res < 0) {
1327                         w->leaf = rt;
1328                         res = fib6_del(rt, &info);
1329                         if (res) {
1330 #if RT6_DEBUG >= 2
1331                                 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1332 #endif
1333                                 continue;
1334                         }
1335                         return 0;
1336                 }
1337                 WARN_ON(res != 0);
1338         }
1339         w->leaf = rt;
1340         return 0;
1341 }
1342
1343 /*
1344  *      Convenient frontend to tree walker.
1345  *
1346  *      func is called on each route.
1347  *              It may return -1 -> delete this route.
1348  *                            0  -> continue walking
1349  *
1350  *      prune==1 -> only immediate children of node (certainly,
1351  *      ignoring pure split nodes) will be scanned.
1352  */
1353
1354 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1355                             int (*func)(struct rt6_info *, void *arg),
1356                             int prune, void *arg)
1357 {
1358         struct fib6_cleaner_t c;
1359
1360         c.w.root = root;
1361         c.w.func = fib6_clean_node;
1362         c.w.prune = prune;
1363         c.w.count = 0;
1364         c.w.skip = 0;
1365         c.func = func;
1366         c.arg = arg;
1367         c.net = net;
1368
1369         fib6_walk(&c.w);
1370 }
1371
1372 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1373                     int prune, void *arg)
1374 {
1375         struct fib6_table *table;
1376         struct hlist_node *node;
1377         struct hlist_head *head;
1378         unsigned int h;
1379
1380         rcu_read_lock();
1381         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1382                 head = &net->ipv6.fib_table_hash[h];
1383                 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1384                         write_lock_bh(&table->tb6_lock);
1385                         fib6_clean_tree(net, &table->tb6_root,
1386                                         func, prune, arg);
1387                         write_unlock_bh(&table->tb6_lock);
1388                 }
1389         }
1390         rcu_read_unlock();
1391 }
1392
1393 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1394 {
1395         if (rt->rt6i_flags & RTF_CACHE) {
1396                 RT6_TRACE("pruning clone %p\n", rt);
1397                 return -1;
1398         }
1399
1400         return 0;
1401 }
1402
1403 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1404                               struct rt6_info *rt)
1405 {
1406         fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1407 }
1408
1409 /*
1410  *      Garbage collection
1411  */
1412
1413 static struct fib6_gc_args
1414 {
1415         int                     timeout;
1416         int                     more;
1417 } gc_args;
1418
1419 static int fib6_age(struct rt6_info *rt, void *arg)
1420 {
1421         unsigned long now = jiffies;
1422
1423         /*
1424          *      check addrconf expiration here.
1425          *      Routes are expired even if they are in use.
1426          *
1427          *      Also age clones. Note, that clones are aged out
1428          *      only if they are not in use now.
1429          */
1430
1431         if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1432                 if (time_after(now, rt->rt6i_expires)) {
1433                         RT6_TRACE("expiring %p\n", rt);
1434                         return -1;
1435                 }
1436                 gc_args.more++;
1437         } else if (rt->rt6i_flags & RTF_CACHE) {
1438                 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1439                     time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1440                         RT6_TRACE("aging clone %p\n", rt);
1441                         return -1;
1442                 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1443                            (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1444                         RT6_TRACE("purging route %p via non-router but gateway\n",
1445                                   rt);
1446                         return -1;
1447                 }
1448                 gc_args.more++;
1449         }
1450
1451         return 0;
1452 }
1453
1454 static DEFINE_SPINLOCK(fib6_gc_lock);
1455
1456 void fib6_run_gc(unsigned long expires, struct net *net)
1457 {
1458         if (expires != ~0UL) {
1459                 spin_lock_bh(&fib6_gc_lock);
1460                 gc_args.timeout = expires ? (int)expires :
1461                         net->ipv6.sysctl.ip6_rt_gc_interval;
1462         } else {
1463                 if (!spin_trylock_bh(&fib6_gc_lock)) {
1464                         mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1465                         return;
1466                 }
1467                 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1468         }
1469
1470         gc_args.more = icmp6_dst_gc();
1471
1472         fib6_clean_all(net, fib6_age, 0, NULL);
1473
1474         if (gc_args.more)
1475                 mod_timer(&net->ipv6.ip6_fib_timer,
1476                           round_jiffies(jiffies
1477                                         + net->ipv6.sysctl.ip6_rt_gc_interval));
1478         else
1479                 del_timer(&net->ipv6.ip6_fib_timer);
1480         spin_unlock_bh(&fib6_gc_lock);
1481 }
1482
1483 static void fib6_gc_timer_cb(unsigned long arg)
1484 {
1485         fib6_run_gc(0, (struct net *)arg);
1486 }
1487
1488 static int __net_init fib6_net_init(struct net *net)
1489 {
1490         setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1491
1492         net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1493         if (!net->ipv6.rt6_stats)
1494                 goto out_timer;
1495
1496         net->ipv6.fib_table_hash = kcalloc(FIB6_TABLE_HASHSZ,
1497                                            sizeof(*net->ipv6.fib_table_hash),
1498                                            GFP_KERNEL);
1499         if (!net->ipv6.fib_table_hash)
1500                 goto out_rt6_stats;
1501
1502         net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1503                                           GFP_KERNEL);
1504         if (!net->ipv6.fib6_main_tbl)
1505                 goto out_fib_table_hash;
1506
1507         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1508         net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1509         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1510                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1511
1512 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1513         net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1514                                            GFP_KERNEL);
1515         if (!net->ipv6.fib6_local_tbl)
1516                 goto out_fib6_main_tbl;
1517         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1518         net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1519         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1520                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1521 #endif
1522         fib6_tables_init(net);
1523
1524         return 0;
1525
1526 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1527 out_fib6_main_tbl:
1528         kfree(net->ipv6.fib6_main_tbl);
1529 #endif
1530 out_fib_table_hash:
1531         kfree(net->ipv6.fib_table_hash);
1532 out_rt6_stats:
1533         kfree(net->ipv6.rt6_stats);
1534 out_timer:
1535         return -ENOMEM;
1536  }
1537
1538 static void fib6_net_exit(struct net *net)
1539 {
1540         rt6_ifdown(net, NULL);
1541         del_timer_sync(&net->ipv6.ip6_fib_timer);
1542
1543 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1544         kfree(net->ipv6.fib6_local_tbl);
1545 #endif
1546         kfree(net->ipv6.fib6_main_tbl);
1547         kfree(net->ipv6.fib_table_hash);
1548         kfree(net->ipv6.rt6_stats);
1549 }
1550
1551 static struct pernet_operations fib6_net_ops = {
1552         .init = fib6_net_init,
1553         .exit = fib6_net_exit,
1554 };
1555
1556 int __init fib6_init(void)
1557 {
1558         int ret = -ENOMEM;
1559
1560         fib6_node_kmem = kmem_cache_create("fib6_nodes",
1561                                            sizeof(struct fib6_node),
1562                                            0, SLAB_HWCACHE_ALIGN,
1563                                            NULL);
1564         if (!fib6_node_kmem)
1565                 goto out;
1566
1567         ret = register_pernet_subsys(&fib6_net_ops);
1568         if (ret)
1569                 goto out_kmem_cache_create;
1570
1571         ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib);
1572         if (ret)
1573                 goto out_unregister_subsys;
1574 out:
1575         return ret;
1576
1577 out_unregister_subsys:
1578         unregister_pernet_subsys(&fib6_net_ops);
1579 out_kmem_cache_create:
1580         kmem_cache_destroy(fib6_node_kmem);
1581         goto out;
1582 }
1583
1584 void fib6_gc_cleanup(void)
1585 {
1586         unregister_pernet_subsys(&fib6_net_ops);
1587         kmem_cache_destroy(fib6_node_kmem);
1588 }