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 #include <linux/slab.h>
  30
  31 #ifdef  CONFIG_PROC_FS
  32 #include <linux/proc_fs.h>
  33 #endif
  34
  35 #include <net/ipv6.h>
  36 #include <net/ndisc.h>
  37 #include <net/addrconf.h>
  38
  39 #include <net/ip6_fib.h>
  40 #include <net/ip6_route.h>
  41
  42 #define RT6_DEBUG 2
  43
  44 #if RT6_DEBUG >= 3
  45 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
  46 #else
  47 #define RT6_TRACE(x...) do { ; } while (0)
  48 #endif
  49
  50 static struct kmem_cache * fib6_node_kmem __read_mostly;
  51
  52 enum fib_walk_state_t
  53 {
  54 #ifdef CONFIG_IPV6_SUBTREES
  55         FWS_S,
  56 #endif
  57         FWS_L,
  58         FWS_R,
  59         FWS_C,
  60         FWS_U
  61 };
  62
  63 struct fib6_cleaner_t
  64 {
  65         struct fib6_walker_t w;
  66         struct net *net;
  67         int (*func)(struct rt6_info *, void *arg);
  68         void *arg;
  69 };
  70
  71 static DEFINE_RWLOCK(fib6_walker_lock);
  72
  73 #ifdef CONFIG_IPV6_SUBTREES
  74 #define FWS_INIT FWS_S
  75 #else
  76 #define FWS_INIT FWS_L
  77 #endif
  78
  79 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
  80                               struct rt6_info *rt);
  81 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
  82 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
  83 static int fib6_walk(struct fib6_walker_t *w);
  84 static int fib6_walk_continue(struct fib6_walker_t *w);
  85
  86 /*
  87  *      A routing update causes an increase of the serial number on the
  88  *      affected subtree. This allows for cached routes to be asynchronously
  89  *      tested when modifications are made to the destination cache as a
  90  *      result of redirects, path MTU changes, etc.
  91  */
  92
  93 static __u32 rt_sernum;
  94
  95 static void fib6_gc_timer_cb(unsigned long arg);
  96
  97 static LIST_HEAD(fib6_walkers);
  98 #define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
  99
 100 static inline void fib6_walker_link(struct fib6_walker_t *w)
 101 {
 102         write_lock_bh(&fib6_walker_lock);
 103         list_add(&w->lh, &fib6_walkers);
 104         write_unlock_bh(&fib6_walker_lock);
 105 }
 106
 107 static inline void fib6_walker_unlink(struct fib6_walker_t *w)
 108 {
 109         write_lock_bh(&fib6_walker_lock);
 110         list_del(&w->lh);
 111         write_unlock_bh(&fib6_walker_lock);
 112 }
 113 static __inline__ u32 fib6_new_sernum(void)
 114 {
 115         u32 n = ++rt_sernum;
 116         if ((__s32)n <= 0)
 117                 rt_sernum = n = 1;
 118         return n;
 119 }
 120
 121 /*
 122  *      Auxiliary address test functions for the radix tree.
 123  *
 124  *      These assume a 32bit processor (although it will work on
 125  *      64bit processors)
 126  */
 127
 128 /*
 129  *      test bit
 130  */
 131 #if defined(__LITTLE_ENDIAN)
 132 # define BITOP_BE32_SWIZZLE     (0x1F & ~7)
 133 #else
 134 # define BITOP_BE32_SWIZZLE     0
 135 #endif
 136
 137 static __inline__ __be32 addr_bit_set(void *token, int fn_bit)
 138 {
 139         __be32 *addr = token;
 140         /*
 141          * Here,
 142          *      1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
 143          * is optimized version of
 144          *      htonl(1 << ((~fn_bit)&0x1F))
 145          * See include/asm-generic/bitops/le.h.
 146          */
 147         return (1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & addr[fn_bit >> 5];
 148 }
 149
 150 static __inline__ struct fib6_node * node_alloc(void)
 151 {
 152         struct fib6_node *fn;
 153
 154         fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
 155
 156         return fn;
 157 }
 158
 159 static __inline__ void node_free(struct fib6_node * fn)
 160 {
 161         kmem_cache_free(fib6_node_kmem, fn);
 162 }
 163
 164 static __inline__ void rt6_release(struct rt6_info *rt)
 165 {
 166         if (atomic_dec_and_test(&rt->rt6i_ref))
 167                 dst_free(&rt->u.dst);
 168 }
 169
 170 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 171 {
 172         unsigned int h;
 173
 174         /*
 175          * Initialize table lock at a single place to give lockdep a key,
 176          * tables aren't visible prior to being linked to the list.
 177          */
 178         rwlock_init(&tb->tb6_lock);
 179
 180         h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
 181
 182         /*
 183          * No protection necessary, this is the only list mutatation
 184          * operation, tables never disappear once they exist.
 185          */
 186         hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
 187 }
 188
 189 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 190
 191 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
 192 {
 193         struct fib6_table *table;
 194
 195         table = kzalloc(sizeof(*table), GFP_ATOMIC);
 196         if (table != NULL) {
 197                 table->tb6_id = id;
 198                 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
 199                 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
 200         }
 201
 202         return table;
 203 }
 204
 205 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 206 {
 207         struct fib6_table *tb;
 208
 209         if (id == 0)
 210                 id = RT6_TABLE_MAIN;
 211         tb = fib6_get_table(net, id);
 212         if (tb)
 213                 return tb;
 214
 215         tb = fib6_alloc_table(net, id);
 216         if (tb != NULL)
 217                 fib6_link_table(net, tb);
 218
 219         return tb;
 220 }
 221
 222 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 223 {
 224         struct fib6_table *tb;
 225         struct hlist_head *head;
 226         struct hlist_node *node;
 227         unsigned int h;
 228
 229         if (id == 0)
 230                 id = RT6_TABLE_MAIN;
 231         h = id & (FIB6_TABLE_HASHSZ - 1);
 232         rcu_read_lock();
 233         head = &net->ipv6.fib_table_hash[h];
 234         hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
 235                 if (tb->tb6_id == id) {
 236                         rcu_read_unlock();
 237                         return tb;
 238                 }
 239         }
 240         rcu_read_unlock();
 241
 242         return NULL;
 243 }
 244
 245 static void __net_init fib6_tables_init(struct net *net)
 246 {
 247         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 248         fib6_link_table(net, net->ipv6.fib6_local_tbl);
 249 }
 250 #else
 251
 252 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 253 {
 254         return fib6_get_table(net, id);
 255 }
 256
 257 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 258 {
 259           return net->ipv6.fib6_main_tbl;
 260 }
 261
 262 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
 263                                    int flags, pol_lookup_t lookup)
 264 {
 265         return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl, flags);
 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 }
 272
 273 #endif
 274
 275 static int fib6_dump_node(struct fib6_walker_t *w)
 276 {
 277         int res;
 278         struct rt6_info *rt;
 279
 280         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
 281                 res = rt6_dump_route(rt, w->args);
 282                 if (res < 0) {
 283                         /* Frame is full, suspend walking */
 284                         w->leaf = rt;
 285                         return 1;
 286                 }
 287                 WARN_ON(res == 0);
 288         }
 289         w->leaf = NULL;
 290         return 0;
 291 }
 292
 293 static void fib6_dump_end(struct netlink_callback *cb)
 294 {
 295         struct fib6_walker_t *w = (void*)cb->args[2];
 296
 297         if (w) {
 298                 if (cb->args[4]) {
 299                         cb->args[4] = 0;
 300                         fib6_walker_unlink(w);
 301                 }
 302                 cb->args[2] = 0;
 303                 kfree(w);
 304         }
 305         cb->done = (void*)cb->args[3];
 306         cb->args[1] = 3;
 307 }
 308
 309 static int fib6_dump_done(struct netlink_callback *cb)
 310 {
 311         fib6_dump_end(cb);
 312         return cb->done ? cb->done(cb) : 0;
 313 }
 314
 315 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 316                            struct netlink_callback *cb)
 317 {
 318         struct fib6_walker_t *w;
 319         int res;
 320
 321         w = (void *)cb->args[2];
 322         w->root = &table->tb6_root;
 323
 324         if (cb->args[4] == 0) {
 325                 w->count = 0;
 326                 w->skip = 0;
 327
 328                 read_lock_bh(&table->tb6_lock);
 329                 res = fib6_walk(w);
 330                 read_unlock_bh(&table->tb6_lock);
 331                 if (res > 0) {
 332                         cb->args[4] = 1;
 333                         cb->args[5] = w->root->fn_sernum;
 334                 }
 335         } else {
 336                 if (cb->args[5] != w->root->fn_sernum) {
 337                         /* Begin at the root if the tree changed */
 338                         cb->args[5] = w->root->fn_sernum;
 339                         w->state = FWS_INIT;
 340                         w->node = w->root;
 341                         w->skip = w->count;
 342                 } else
 343                         w->skip = 0;
 344
 345                 read_lock_bh(&table->tb6_lock);
 346                 res = fib6_walk_continue(w);
 347                 read_unlock_bh(&table->tb6_lock);
 348                 if (res <= 0) {
 349                         fib6_walker_unlink(w);
 350                         cb->args[4] = 0;
 351                 }
 352         }
 353
 354         return res;
 355 }
 356
 357 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 358 {
 359         struct net *net = sock_net(skb->sk);
 360         unsigned int h, s_h;
 361         unsigned int e = 0, s_e;
 362         struct rt6_rtnl_dump_arg arg;
 363         struct fib6_walker_t *w;
 364         struct fib6_table *tb;
 365         struct hlist_node *node;
 366         struct hlist_head *head;
 367         int res = 0;
 368
 369         s_h = cb->args[0];
 370         s_e = cb->args[1];
 371
 372         w = (void *)cb->args[2];
 373         if (w == NULL) {
 374                 /* New dump:
 375                  *
 376                  * 1. hook callback destructor.
 377                  */
 378                 cb->args[3] = (long)cb->done;
 379                 cb->done = fib6_dump_done;
 380
 381                 /*
 382                  * 2. allocate and initialize walker.
 383                  */
 384                 w = kzalloc(sizeof(*w), GFP_ATOMIC);
 385                 if (w == NULL)
 386                         return -ENOMEM;
 387                 w->func = fib6_dump_node;
 388                 cb->args[2] = (long)w;
 389         }
 390
 391         arg.skb = skb;
 392         arg.cb = cb;
 393         arg.net = net;
 394         w->args = &arg;
 395
 396         for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
 397                 e = 0;
 398                 head = &net->ipv6.fib_table_hash[h];
 399                 hlist_for_each_entry(tb, node, head, tb6_hlist) {
 400                         if (e < s_e)
 401                                 goto next;
 402                         res = fib6_dump_table(tb, skb, cb);
 403                         if (res != 0)
 404                                 goto out;
 405 next:
 406                         e++;
 407                 }
 408         }
 409 out:
 410         cb->args[1] = e;
 411         cb->args[0] = h;
 412
 413         res = res < 0 ? res : skb->len;
 414         if (res <= 0)
 415                 fib6_dump_end(cb);
 416         return res;
 417 }
 418
 419 /*
 420  *      Routing Table
 421  *
 422  *      return the appropriate node for a routing tree "add" operation
 423  *      by either creating and inserting or by returning an existing
 424  *      node.
 425  */
 426
 427 static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
 428                                      int addrlen, int plen,
 429                                      int offset)
 430 {
 431         struct fib6_node *fn, *in, *ln;
 432         struct fib6_node *pn = NULL;
 433         struct rt6key *key;
 434         int     bit;
 435         __be32  dir = 0;
 436         __u32   sernum = fib6_new_sernum();
 437
 438         RT6_TRACE("fib6_add_1\n");
 439
 440         /* insert node in tree */
 441
 442         fn = root;
 443
 444         do {
 445                 key = (struct rt6key *)((u8 *)fn->leaf + offset);
 446
 447                 /*
 448                  *      Prefix match
 449                  */
 450                 if (plen < fn->fn_bit ||
 451                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 452                         goto insert_above;
 453
 454                 /*
 455                  *      Exact match ?
 456                  */
 457
 458                 if (plen == fn->fn_bit) {
 459                         /* clean up an intermediate node */
 460                         if ((fn->fn_flags & RTN_RTINFO) == 0) {
 461                                 rt6_release(fn->leaf);
 462                                 fn->leaf = NULL;
 463                         }
 464
 465                         fn->fn_sernum = sernum;
 466
 467                         return fn;
 468                 }
 469
 470                 /*
 471                  *      We have more bits to go
 472                  */
 473
 474                 /* Try to walk down on tree. */
 475                 fn->fn_sernum = sernum;
 476                 dir = addr_bit_set(addr, fn->fn_bit);
 477                 pn = fn;
 478                 fn = dir ? fn->right: fn->left;
 479         } while (fn);
 480
 481         /*
 482          *      We walked to the bottom of tree.
 483          *      Create new leaf node without children.
 484          */
 485
 486         ln = node_alloc();
 487
 488         if (ln == NULL)
 489                 return NULL;
 490         ln->fn_bit = plen;
 491
 492         ln->parent = pn;
 493         ln->fn_sernum = sernum;
 494
 495         if (dir)
 496                 pn->right = ln;
 497         else
 498                 pn->left  = ln;
 499
 500         return ln;
 501
 502
 503 insert_above:
 504         /*
 505          * split since we don't have a common prefix anymore or
 506          * we have a less significant route.
 507          * we've to insert an intermediate node on the list
 508          * this new node will point to the one we need to create
 509          * and the current
 510          */
 511
 512         pn = fn->parent;
 513
 514         /* find 1st bit in difference between the 2 addrs.
 515
 516            See comment in __ipv6_addr_diff: bit may be an invalid value,
 517            but if it is >= plen, the value is ignored in any case.
 518          */
 519
 520         bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
 521
 522         /*
 523          *              (intermediate)[in]
 524          *                /        \
 525          *      (new leaf node)[ln] (old node)[fn]
 526          */
 527         if (plen > bit) {
 528                 in = node_alloc();
 529                 ln = node_alloc();
 530
 531                 if (in == NULL || ln == NULL) {
 532                         if (in)
 533                                 node_free(in);
 534                         if (ln)
 535                                 node_free(ln);
 536                         return NULL;
 537                 }
 538
 539                 /*
 540                  * new intermediate node.
 541                  * RTN_RTINFO will
 542                  * be off since that an address that chooses one of
 543                  * the branches would not match less specific routes
 544                  * in the other branch
 545                  */
 546
 547                 in->fn_bit = bit;
 548
 549                 in->parent = pn;
 550                 in->leaf = fn->leaf;
 551                 atomic_inc(&in->leaf->rt6i_ref);
 552
 553                 in->fn_sernum = sernum;
 554
 555                 /* update parent pointer */
 556                 if (dir)
 557                         pn->right = in;
 558                 else
 559                         pn->left  = in;
 560
 561                 ln->fn_bit = plen;
 562
 563                 ln->parent = in;
 564                 fn->parent = in;
 565
 566                 ln->fn_sernum = sernum;
 567
 568                 if (addr_bit_set(addr, bit)) {
 569                         in->right = ln;
 570                         in->left  = fn;
 571                 } else {
 572                         in->left  = ln;
 573                         in->right = fn;
 574                 }
 575         } else { /* plen <= bit */
 576
 577                 /*
 578                  *              (new leaf node)[ln]
 579                  *                /        \
 580                  *           (old node)[fn] NULL
 581                  */
 582
 583                 ln = node_alloc();
 584
 585                 if (ln == NULL)
 586                         return NULL;
 587
 588                 ln->fn_bit = plen;
 589
 590                 ln->parent = pn;
 591
 592                 ln->fn_sernum = sernum;
 593
 594                 if (dir)
 595                         pn->right = ln;
 596                 else
 597                         pn->left  = ln;
 598
 599                 if (addr_bit_set(&key->addr, plen))
 600                         ln->right = fn;
 601                 else
 602                         ln->left  = fn;
 603
 604                 fn->parent = ln;
 605         }
 606         return ln;
 607 }
 608
 609 /*
 610  *      Insert routing information in a node.
 611  */
 612
 613 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 614                             struct nl_info *info)
 615 {
 616         struct rt6_info *iter = NULL;
 617         struct rt6_info **ins;
 618
 619         ins = &fn->leaf;
 620
 621         for (iter = fn->leaf; iter; iter=iter->u.dst.rt6_next) {
 622                 /*
 623                  *      Search for duplicates
 624                  */
 625
 626                 if (iter->rt6i_metric == rt->rt6i_metric) {
 627                         /*
 628                          *      Same priority level
 629                          */
 630
 631                         if (iter->rt6i_dev == rt->rt6i_dev &&
 632                             iter->rt6i_idev == rt->rt6i_idev &&
 633                             ipv6_addr_equal(&iter->rt6i_gateway,
 634                                             &rt->rt6i_gateway)) {
 635                                 if (!(iter->rt6i_flags&RTF_EXPIRES))
 636                                         return -EEXIST;
 637                                 iter->rt6i_expires = rt->rt6i_expires;
 638                                 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
 639                                         iter->rt6i_flags &= ~RTF_EXPIRES;
 640                                         iter->rt6i_expires = 0;
 641                                 }
 642                                 return -EEXIST;
 643                         }
 644                 }
 645
 646                 if (iter->rt6i_metric > rt->rt6i_metric)
 647                         break;
 648
 649                 ins = &iter->u.dst.rt6_next;
 650         }
 651
 652         /* Reset round-robin state, if necessary */
 653         if (ins == &fn->leaf)
 654                 fn->rr_ptr = NULL;
 655
 656         /*
 657          *      insert node
 658          */
 659
 660         rt->u.dst.rt6_next = iter;
 661         *ins = rt;
 662         rt->rt6i_node = fn;
 663         atomic_inc(&rt->rt6i_ref);
 664         inet6_rt_notify(RTM_NEWROUTE, rt, info);
 665         info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
 666
 667         if ((fn->fn_flags & RTN_RTINFO) == 0) {
 668                 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
 669                 fn->fn_flags |= RTN_RTINFO;
 670         }
 671
 672         return 0;
 673 }
 674
 675 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
 676 {
 677         if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
 678             (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
 679                 mod_timer(&net->ipv6.ip6_fib_timer,
 680                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 681 }
 682
 683 void fib6_force_start_gc(struct net *net)
 684 {
 685         if (!timer_pending(&net->ipv6.ip6_fib_timer))
 686                 mod_timer(&net->ipv6.ip6_fib_timer,
 687                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 688 }
 689
 690 /*
 691  *      Add routing information to the routing tree.
 692  *      <destination addr>/<source addr>
 693  *      with source addr info in sub-trees
 694  */
 695
 696 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
 697 {
 698         struct fib6_node *fn, *pn = NULL;
 699         int err = -ENOMEM;
 700
 701         fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
 702                         rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
 703
 704         if (fn == NULL)
 705                 goto out;
 706
 707         pn = fn;
 708
 709 #ifdef CONFIG_IPV6_SUBTREES
 710         if (rt->rt6i_src.plen) {
 711                 struct fib6_node *sn;
 712
 713                 if (fn->subtree == NULL) {
 714                         struct fib6_node *sfn;
 715
 716                         /*
 717                          * Create subtree.
 718                          *
 719                          *              fn[main tree]
 720                          *              |
 721                          *              sfn[subtree root]
 722                          *                 \
 723                          *                  sn[new leaf node]
 724                          */
 725
 726                         /* Create subtree root node */
 727                         sfn = node_alloc();
 728                         if (sfn == NULL)
 729                                 goto st_failure;
 730
 731                         sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
 732                         atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
 733                         sfn->fn_flags = RTN_ROOT;
 734                         sfn->fn_sernum = fib6_new_sernum();
 735
 736                         /* Now add the first leaf node to new subtree */
 737
 738                         sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
 739                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
 740                                         offsetof(struct rt6_info, rt6i_src));
 741
 742                         if (sn == NULL) {
 743                                 /* If it is failed, discard just allocated
 744                                    root, and then (in st_failure) stale node
 745                                    in main tree.
 746                                  */
 747                                 node_free(sfn);
 748                                 goto st_failure;
 749                         }
 750
 751                         /* Now link new subtree to main tree */
 752                         sfn->parent = fn;
 753                         fn->subtree = sfn;
 754                 } else {
 755                         sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
 756                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
 757                                         offsetof(struct rt6_info, rt6i_src));
 758
 759                         if (sn == NULL)
 760                                 goto st_failure;
 761                 }
 762
 763                 if (fn->leaf == NULL) {
 764                         fn->leaf = rt;
 765                         atomic_inc(&rt->rt6i_ref);
 766                 }
 767                 fn = sn;
 768         }
 769 #endif
 770
 771         err = fib6_add_rt2node(fn, rt, info);
 772
 773         if (err == 0) {
 774                 fib6_start_gc(info->nl_net, rt);
 775                 if (!(rt->rt6i_flags&RTF_CACHE))
 776                         fib6_prune_clones(info->nl_net, pn, rt);
 777         }
 778
 779 out:
 780         if (err) {
 781 #ifdef CONFIG_IPV6_SUBTREES
 782                 /*
 783                  * If fib6_add_1 has cleared the old leaf pointer in the
 784                  * super-tree leaf node we have to find a new one for it.
 785                  */
 786                 if (pn != fn && pn->leaf == rt) {
 787                         pn->leaf = NULL;
 788                         atomic_dec(&rt->rt6i_ref);
 789                 }
 790                 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
 791                         pn->leaf = fib6_find_prefix(info->nl_net, pn);
 792 #if RT6_DEBUG >= 2
 793                         if (!pn->leaf) {
 794                                 WARN_ON(pn->leaf == NULL);
 795                                 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
 796                         }
 797 #endif
 798                         atomic_inc(&pn->leaf->rt6i_ref);
 799                 }
 800 #endif
 801                 dst_free(&rt->u.dst);
 802         }
 803         return err;
 804
 805 #ifdef CONFIG_IPV6_SUBTREES
 806         /* Subtree creation failed, probably main tree node
 807            is orphan. If it is, shoot it.
 808          */
 809 st_failure:
 810         if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
 811                 fib6_repair_tree(info->nl_net, fn);
 812         dst_free(&rt->u.dst);
 813         return err;
 814 #endif
 815 }
 816
 817 /*
 818  *      Routing tree lookup
 819  *
 820  */
 821
 822 struct lookup_args {
 823         int             offset;         /* key offset on rt6_info       */
 824         struct in6_addr *addr;          /* search key                   */
 825 };
 826
 827 static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
 828                                         struct lookup_args *args)
 829 {
 830         struct fib6_node *fn;
 831         __be32 dir;
 832
 833         if (unlikely(args->offset == 0))
 834                 return NULL;
 835
 836         /*
 837          *      Descend on a tree
 838          */
 839
 840         fn = root;
 841
 842         for (;;) {
 843                 struct fib6_node *next;
 844
 845                 dir = addr_bit_set(args->addr, fn->fn_bit);
 846
 847                 next = dir ? fn->right : fn->left;
 848
 849                 if (next) {
 850                         fn = next;
 851                         continue;
 852                 }
 853
 854                 break;
 855         }
 856
 857         while(fn) {
 858                 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
 859                         struct rt6key *key;
 860
 861                         key = (struct rt6key *) ((u8 *) fn->leaf +
 862                                                  args->offset);
 863
 864                         if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
 865 #ifdef CONFIG_IPV6_SUBTREES
 866                                 if (fn->subtree)
 867                                         fn = fib6_lookup_1(fn->subtree, args + 1);
 868 #endif
 869                                 if (!fn || fn->fn_flags & RTN_RTINFO)
 870                                         return fn;
 871                         }
 872                 }
 873
 874                 if (fn->fn_flags & RTN_ROOT)
 875                         break;
 876
 877                 fn = fn->parent;
 878         }
 879
 880         return NULL;
 881 }
 882
 883 struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr,
 884                                struct in6_addr *saddr)
 885 {
 886         struct fib6_node *fn;
 887         struct lookup_args args[] = {
 888                 {
 889                         .offset = offsetof(struct rt6_info, rt6i_dst),
 890                         .addr = daddr,
 891                 },
 892 #ifdef CONFIG_IPV6_SUBTREES
 893                 {
 894                         .offset = offsetof(struct rt6_info, rt6i_src),
 895                         .addr = saddr,
 896                 },
 897 #endif
 898                 {
 899                         .offset = 0,    /* sentinel */
 900                 }
 901         };
 902
 903         fn = fib6_lookup_1(root, daddr ? args : args + 1);
 904
 905         if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
 906                 fn = root;
 907
 908         return fn;
 909 }
 910
 911 /*
 912  *      Get node with specified destination prefix (and source prefix,
 913  *      if subtrees are used)
 914  */
 915
 916
 917 static struct fib6_node * fib6_locate_1(struct fib6_node *root,
 918                                         struct in6_addr *addr,
 919                                         int plen, int offset)
 920 {
 921         struct fib6_node *fn;
 922
 923         for (fn = root; fn ; ) {
 924                 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
 925
 926                 /*
 927                  *      Prefix match
 928                  */
 929                 if (plen < fn->fn_bit ||
 930                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 931                         return NULL;
 932
 933                 if (plen == fn->fn_bit)
 934                         return fn;
 935
 936                 /*
 937                  *      We have more bits to go
 938                  */
 939                 if (addr_bit_set(addr, fn->fn_bit))
 940                         fn = fn->right;
 941                 else
 942                         fn = fn->left;
 943         }
 944         return NULL;
 945 }
 946
 947 struct fib6_node * fib6_locate(struct fib6_node *root,
 948                                struct in6_addr *daddr, int dst_len,
 949                                struct in6_addr *saddr, int src_len)
 950 {
 951         struct fib6_node *fn;
 952
 953         fn = fib6_locate_1(root, daddr, dst_len,
 954                            offsetof(struct rt6_info, rt6i_dst));
 955
 956 #ifdef CONFIG_IPV6_SUBTREES
 957         if (src_len) {
 958                 WARN_ON(saddr == NULL);
 959                 if (fn && fn->subtree)
 960                         fn = fib6_locate_1(fn->subtree, saddr, src_len,
 961                                            offsetof(struct rt6_info, rt6i_src));
 962         }
 963 #endif
 964
 965         if (fn && fn->fn_flags&RTN_RTINFO)
 966                 return fn;
 967
 968         return NULL;
 969 }
 970
 971
 972 /*
 973  *      Deletion
 974  *
 975  */
 976
 977 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
 978 {
 979         if (fn->fn_flags&RTN_ROOT)
 980                 return net->ipv6.ip6_null_entry;
 981
 982         while(fn) {
 983                 if(fn->left)
 984                         return fn->left->leaf;
 985
 986                 if(fn->right)
 987                         return fn->right->leaf;
 988
 989                 fn = FIB6_SUBTREE(fn);
 990         }
 991         return NULL;
 992 }
 993
 994 /*
 995  *      Called to trim the tree of intermediate nodes when possible. "fn"
 996  *      is the node we want to try and remove.
 997  */
 998
 999 static struct fib6_node *fib6_repair_tree(struct net *net,
1000                                            struct fib6_node *fn)
1001 {
1002         int children;
1003         int nstate;
1004         struct fib6_node *child, *pn;
1005         struct fib6_walker_t *w;
1006         int iter = 0;
1007
1008         for (;;) {
1009                 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1010                 iter++;
1011
1012                 WARN_ON(fn->fn_flags & RTN_RTINFO);
1013                 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1014                 WARN_ON(fn->leaf != NULL);
1015
1016                 children = 0;
1017                 child = NULL;
1018                 if (fn->right) child = fn->right, children |= 1;
1019                 if (fn->left) child = fn->left, children |= 2;
1020
1021                 if (children == 3 || FIB6_SUBTREE(fn)
1022 #ifdef CONFIG_IPV6_SUBTREES
1023                     /* Subtree root (i.e. fn) may have one child */
1024                     || (children && fn->fn_flags&RTN_ROOT)
1025 #endif
1026                     ) {
1027                         fn->leaf = fib6_find_prefix(net, fn);
1028 #if RT6_DEBUG >= 2
1029                         if (fn->leaf==NULL) {
1030                                 WARN_ON(!fn->leaf);
1031                                 fn->leaf = net->ipv6.ip6_null_entry;
1032                         }
1033 #endif
1034                         atomic_inc(&fn->leaf->rt6i_ref);
1035                         return fn->parent;
1036                 }
1037
1038                 pn = fn->parent;
1039 #ifdef CONFIG_IPV6_SUBTREES
1040                 if (FIB6_SUBTREE(pn) == fn) {
1041                         WARN_ON(!(fn->fn_flags & RTN_ROOT));
1042                         FIB6_SUBTREE(pn) = NULL;
1043                         nstate = FWS_L;
1044                 } else {
1045                         WARN_ON(fn->fn_flags & RTN_ROOT);
1046 #endif
1047                         if (pn->right == fn) pn->right = child;
1048                         else if (pn->left == fn) pn->left = child;
1049 #if RT6_DEBUG >= 2
1050                         else
1051                                 WARN_ON(1);
1052 #endif
1053                         if (child)
1054                                 child->parent = pn;
1055                         nstate = FWS_R;
1056 #ifdef CONFIG_IPV6_SUBTREES
1057                 }
1058 #endif
1059
1060                 read_lock(&fib6_walker_lock);
1061                 FOR_WALKERS(w) {
1062                         if (child == NULL) {
1063                                 if (w->root == fn) {
1064                                         w->root = w->node = NULL;
1065                                         RT6_TRACE("W %p adjusted by delroot 1\n", w);
1066                                 } else if (w->node == fn) {
1067                                         RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1068                                         w->node = pn;
1069                                         w->state = nstate;
1070                                 }
1071                         } else {
1072                                 if (w->root == fn) {
1073                                         w->root = child;
1074                                         RT6_TRACE("W %p adjusted by delroot 2\n", w);
1075                                 }
1076                                 if (w->node == fn) {
1077                                         w->node = child;
1078                                         if (children&2) {
1079                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1080                                                 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1081                                         } else {
1082                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1083                                                 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1084                                         }
1085                                 }
1086                         }
1087                 }
1088                 read_unlock(&fib6_walker_lock);
1089
1090                 node_free(fn);
1091                 if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn))
1092                         return pn;
1093
1094                 rt6_release(pn->leaf);
1095                 pn->leaf = NULL;
1096                 fn = pn;
1097         }
1098 }
1099
1100 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1101                            struct nl_info *info)
1102 {
1103         struct fib6_walker_t *w;
1104         struct rt6_info *rt = *rtp;
1105         struct net *net = info->nl_net;
1106
1107         RT6_TRACE("fib6_del_route\n");
1108
1109         /* Unlink it */
1110         *rtp = rt->u.dst.rt6_next;
1111         rt->rt6i_node = NULL;
1112         net->ipv6.rt6_stats->fib_rt_entries--;
1113         net->ipv6.rt6_stats->fib_discarded_routes++;
1114
1115         /* Reset round-robin state, if necessary */
1116         if (fn->rr_ptr == rt)
1117                 fn->rr_ptr = NULL;
1118
1119         /* Adjust walkers */
1120         read_lock(&fib6_walker_lock);
1121         FOR_WALKERS(w) {
1122                 if (w->state == FWS_C && w->leaf == rt) {
1123                         RT6_TRACE("walker %p adjusted by delroute\n", w);
1124                         w->leaf = rt->u.dst.rt6_next;
1125                         if (w->leaf == NULL)
1126                                 w->state = FWS_U;
1127                 }
1128         }
1129         read_unlock(&fib6_walker_lock);
1130
1131         rt->u.dst.rt6_next = NULL;
1132
1133         /* If it was last route, expunge its radix tree node */
1134         if (fn->leaf == NULL) {
1135                 fn->fn_flags &= ~RTN_RTINFO;
1136                 net->ipv6.rt6_stats->fib_route_nodes--;
1137                 fn = fib6_repair_tree(net, fn);
1138         }
1139
1140         if (atomic_read(&rt->rt6i_ref) != 1) {
1141                 /* This route is used as dummy address holder in some split
1142                  * nodes. It is not leaked, but it still holds other resources,
1143                  * which must be released in time. So, scan ascendant nodes
1144                  * and replace dummy references to this route with references
1145                  * to still alive ones.
1146                  */
1147                 while (fn) {
1148                         if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
1149                                 fn->leaf = fib6_find_prefix(net, fn);
1150                                 atomic_inc(&fn->leaf->rt6i_ref);
1151                                 rt6_release(rt);
1152                         }
1153                         fn = fn->parent;
1154                 }
1155                 /* No more references are possible at this point. */
1156                 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1157         }
1158
1159         inet6_rt_notify(RTM_DELROUTE, rt, info);
1160         rt6_release(rt);
1161 }
1162
1163 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1164 {
1165         struct net *net = info->nl_net;
1166         struct fib6_node *fn = rt->rt6i_node;
1167         struct rt6_info **rtp;
1168
1169 #if RT6_DEBUG >= 2
1170         if (rt->u.dst.obsolete>0) {
1171                 WARN_ON(fn != NULL);
1172                 return -ENOENT;
1173         }
1174 #endif
1175         if (fn == NULL || rt == net->ipv6.ip6_null_entry)
1176                 return -ENOENT;
1177
1178         WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1179
1180         if (!(rt->rt6i_flags&RTF_CACHE)) {
1181                 struct fib6_node *pn = fn;
1182 #ifdef CONFIG_IPV6_SUBTREES
1183                 /* clones of this route might be in another subtree */
1184                 if (rt->rt6i_src.plen) {
1185                         while (!(pn->fn_flags&RTN_ROOT))
1186                                 pn = pn->parent;
1187                         pn = pn->parent;
1188                 }
1189 #endif
1190                 fib6_prune_clones(info->nl_net, pn, rt);
1191         }
1192
1193         /*
1194          *      Walk the leaf entries looking for ourself
1195          */
1196
1197         for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.dst.rt6_next) {
1198                 if (*rtp == rt) {
1199                         fib6_del_route(fn, rtp, info);
1200                         return 0;
1201                 }
1202         }
1203         return -ENOENT;
1204 }
1205
1206 /*
1207  *      Tree traversal function.
1208  *
1209  *      Certainly, it is not interrupt safe.
1210  *      However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1211  *      It means, that we can modify tree during walking
1212  *      and use this function for garbage collection, clone pruning,
1213  *      cleaning tree when a device goes down etc. etc.
1214  *
1215  *      It guarantees that every node will be traversed,
1216  *      and that it will be traversed only once.
1217  *
1218  *      Callback function w->func may return:
1219  *      0 -> continue walking.
1220  *      positive value -> walking is suspended (used by tree dumps,
1221  *      and probably by gc, if it will be split to several slices)
1222  *      negative value -> terminate walking.
1223  *
1224  *      The function itself returns:
1225  *      0   -> walk is complete.
1226  *      >0  -> walk is incomplete (i.e. suspended)
1227  *      <0  -> walk is terminated by an error.
1228  */
1229
1230 static int fib6_walk_continue(struct fib6_walker_t *w)
1231 {
1232         struct fib6_node *fn, *pn;
1233
1234         for (;;) {
1235                 fn = w->node;
1236                 if (fn == NULL)
1237                         return 0;
1238
1239                 if (w->prune && fn != w->root &&
1240                     fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1241                         w->state = FWS_C;
1242                         w->leaf = fn->leaf;
1243                 }
1244                 switch (w->state) {
1245 #ifdef CONFIG_IPV6_SUBTREES
1246                 case FWS_S:
1247                         if (FIB6_SUBTREE(fn)) {
1248                                 w->node = FIB6_SUBTREE(fn);
1249                                 continue;
1250                         }
1251                         w->state = FWS_L;
1252 #endif
1253                 case FWS_L:
1254                         if (fn->left) {
1255                                 w->node = fn->left;
1256                                 w->state = FWS_INIT;
1257                                 continue;
1258                         }
1259                         w->state = FWS_R;
1260                 case FWS_R:
1261                         if (fn->right) {
1262                                 w->node = fn->right;
1263                                 w->state = FWS_INIT;
1264                                 continue;
1265                         }
1266                         w->state = FWS_C;
1267                         w->leaf = fn->leaf;
1268                 case FWS_C:
1269                         if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1270                                 int err;
1271
1272                                 if (w->count < w->skip) {
1273                                         w->count++;
1274                                         continue;
1275                                 }
1276
1277                                 err = w->func(w);
1278                                 if (err)
1279                                         return err;
1280
1281                                 w->count++;
1282                                 continue;
1283                         }
1284                         w->state = FWS_U;
1285                 case FWS_U:
1286                         if (fn == w->root)
1287                                 return 0;
1288                         pn = fn->parent;
1289                         w->node = pn;
1290 #ifdef CONFIG_IPV6_SUBTREES
1291                         if (FIB6_SUBTREE(pn) == fn) {
1292                                 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1293                                 w->state = FWS_L;
1294                                 continue;
1295                         }
1296 #endif
1297                         if (pn->left == fn) {
1298                                 w->state = FWS_R;
1299                                 continue;
1300                         }
1301                         if (pn->right == fn) {
1302                                 w->state = FWS_C;
1303                                 w->leaf = w->node->leaf;
1304                                 continue;
1305                         }
1306 #if RT6_DEBUG >= 2
1307                         WARN_ON(1);
1308 #endif
1309                 }
1310         }
1311 }
1312
1313 static int fib6_walk(struct fib6_walker_t *w)
1314 {
1315         int res;
1316
1317         w->state = FWS_INIT;
1318         w->node = w->root;
1319
1320         fib6_walker_link(w);
1321         res = fib6_walk_continue(w);
1322         if (res <= 0)
1323                 fib6_walker_unlink(w);
1324         return res;
1325 }
1326
1327 static int fib6_clean_node(struct fib6_walker_t *w)
1328 {
1329         int res;
1330         struct rt6_info *rt;
1331         struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1332         struct nl_info info = {
1333                 .nl_net = c->net,
1334         };
1335
1336         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
1337                 res = c->func(rt, c->arg);
1338                 if (res < 0) {
1339                         w->leaf = rt;
1340                         res = fib6_del(rt, &info);
1341                         if (res) {
1342 #if RT6_DEBUG >= 2
1343                                 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1344 #endif
1345                                 continue;
1346                         }
1347                         return 0;
1348                 }
1349                 WARN_ON(res != 0);
1350         }
1351         w->leaf = rt;
1352         return 0;
1353 }
1354
1355 /*
1356  *      Convenient frontend to tree walker.
1357  *
1358  *      func is called on each route.
1359  *              It may return -1 -> delete this route.
1360  *                            0  -> continue walking
1361  *
1362  *      prune==1 -> only immediate children of node (certainly,
1363  *      ignoring pure split nodes) will be scanned.
1364  */
1365
1366 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1367                             int (*func)(struct rt6_info *, void *arg),
1368                             int prune, void *arg)
1369 {
1370         struct fib6_cleaner_t c;
1371
1372         c.w.root = root;
1373         c.w.func = fib6_clean_node;
1374         c.w.prune = prune;
1375         c.w.count = 0;
1376         c.w.skip = 0;
1377         c.func = func;
1378         c.arg = arg;
1379         c.net = net;
1380
1381         fib6_walk(&c.w);
1382 }
1383
1384 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1385                     int prune, void *arg)
1386 {
1387         struct fib6_table *table;
1388         struct hlist_node *node;
1389         struct hlist_head *head;
1390         unsigned int h;
1391
1392         rcu_read_lock();
1393         for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1394                 head = &net->ipv6.fib_table_hash[h];
1395                 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1396                         write_lock_bh(&table->tb6_lock);
1397                         fib6_clean_tree(net, &table->tb6_root,
1398                                         func, prune, arg);
1399                         write_unlock_bh(&table->tb6_lock);
1400                 }
1401         }
1402         rcu_read_unlock();
1403 }
1404
1405 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1406 {
1407         if (rt->rt6i_flags & RTF_CACHE) {
1408                 RT6_TRACE("pruning clone %p\n", rt);
1409                 return -1;
1410         }
1411
1412         return 0;
1413 }
1414
1415 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1416                               struct rt6_info *rt)
1417 {
1418         fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1419 }
1420
1421 /*
1422  *      Garbage collection
1423  */
1424
1425 static struct fib6_gc_args
1426 {
1427         int                     timeout;
1428         int                     more;
1429 } gc_args;
1430
1431 static int fib6_age(struct rt6_info *rt, void *arg)
1432 {
1433         unsigned long now = jiffies;
1434
1435         /*
1436          *      check addrconf expiration here.
1437          *      Routes are expired even if they are in use.
1438          *
1439          *      Also age clones. Note, that clones are aged out
1440          *      only if they are not in use now.
1441          */
1442
1443         if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1444                 if (time_after(now, rt->rt6i_expires)) {
1445                         RT6_TRACE("expiring %p\n", rt);
1446                         return -1;
1447                 }
1448                 gc_args.more++;
1449         } else if (rt->rt6i_flags & RTF_CACHE) {
1450                 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1451                     time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1452                         RT6_TRACE("aging clone %p\n", rt);
1453                         return -1;
1454                 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1455                            (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1456                         RT6_TRACE("purging route %p via non-router but gateway\n",
1457                                   rt);
1458                         return -1;
1459                 }
1460                 gc_args.more++;
1461         }
1462
1463         return 0;
1464 }
1465
1466 static DEFINE_SPINLOCK(fib6_gc_lock);
1467
1468 void fib6_run_gc(unsigned long expires, struct net *net)
1469 {
1470         if (expires != ~0UL) {
1471                 spin_lock_bh(&fib6_gc_lock);
1472                 gc_args.timeout = expires ? (int)expires :
1473                         net->ipv6.sysctl.ip6_rt_gc_interval;
1474         } else {
1475                 if (!spin_trylock_bh(&fib6_gc_lock)) {
1476                         mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1477                         return;
1478                 }
1479                 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1480         }
1481
1482         gc_args.more = icmp6_dst_gc();
1483
1484         fib6_clean_all(net, fib6_age, 0, NULL);
1485
1486         if (gc_args.more)
1487                 mod_timer(&net->ipv6.ip6_fib_timer,
1488                           round_jiffies(jiffies
1489                                         + net->ipv6.sysctl.ip6_rt_gc_interval));
1490         else
1491                 del_timer(&net->ipv6.ip6_fib_timer);
1492         spin_unlock_bh(&fib6_gc_lock);
1493 }
1494
1495 static void fib6_gc_timer_cb(unsigned long arg)
1496 {
1497         fib6_run_gc(0, (struct net *)arg);
1498 }
1499
1500 static int __net_init fib6_net_init(struct net *net)
1501 {
1502         setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1503
1504         net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1505         if (!net->ipv6.rt6_stats)
1506                 goto out_timer;
1507
1508         net->ipv6.fib_table_hash = kcalloc(FIB6_TABLE_HASHSZ,
1509                                            sizeof(*net->ipv6.fib_table_hash),
1510                                            GFP_KERNEL);
1511         if (!net->ipv6.fib_table_hash)
1512                 goto out_rt6_stats;
1513
1514         net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1515                                           GFP_KERNEL);
1516         if (!net->ipv6.fib6_main_tbl)
1517                 goto out_fib_table_hash;
1518
1519         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1520         net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1521         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1522                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1523
1524 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1525         net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1526                                            GFP_KERNEL);
1527         if (!net->ipv6.fib6_local_tbl)
1528                 goto out_fib6_main_tbl;
1529         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1530         net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1531         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1532                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1533 #endif
1534         fib6_tables_init(net);
1535
1536         return 0;
1537
1538 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1539 out_fib6_main_tbl:
1540         kfree(net->ipv6.fib6_main_tbl);
1541 #endif
1542 out_fib_table_hash:
1543         kfree(net->ipv6.fib_table_hash);
1544 out_rt6_stats:
1545         kfree(net->ipv6.rt6_stats);
1546 out_timer:
1547         return -ENOMEM;
1548  }
1549
1550 static void fib6_net_exit(struct net *net)
1551 {
1552         rt6_ifdown(net, NULL);
1553         del_timer_sync(&net->ipv6.ip6_fib_timer);
1554
1555 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1556         kfree(net->ipv6.fib6_local_tbl);
1557 #endif
1558         kfree(net->ipv6.fib6_main_tbl);
1559         kfree(net->ipv6.fib_table_hash);
1560         kfree(net->ipv6.rt6_stats);
1561 }
1562
1563 static struct pernet_operations fib6_net_ops = {
1564         .init = fib6_net_init,
1565         .exit = fib6_net_exit,
1566 };
1567
1568 int __init fib6_init(void)
1569 {
1570         int ret = -ENOMEM;
1571
1572         fib6_node_kmem = kmem_cache_create("fib6_nodes",
1573                                            sizeof(struct fib6_node),
1574                                            0, SLAB_HWCACHE_ALIGN,
1575                                            NULL);
1576         if (!fib6_node_kmem)
1577                 goto out;
1578
1579         ret = register_pernet_subsys(&fib6_net_ops);
1580         if (ret)
1581                 goto out_kmem_cache_create;
1582
1583         ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib);
1584         if (ret)
1585                 goto out_unregister_subsys;
1586 out:
1587         return ret;
1588
1589 out_unregister_subsys:
1590         unregister_pernet_subsys(&fib6_net_ops);
1591 out_kmem_cache_create:
1592         kmem_cache_destroy(fib6_node_kmem);
1593         goto out;
1594 }
1595
1596 void fib6_gc_cleanup(void)
1597 {
1598         unregister_pernet_subsys(&fib6_net_ops);
1599         kmem_cache_destroy(fib6_node_kmem);
1600 }