Merge branch 'for_rmk' of git://git.mnementh.co.uk/linux-2.6-im
[linux-2.6-block.git] / 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 struct fib6_walker_t fib6_walker_list = {
97         .prev   = &fib6_walker_list,
98         .next   = &fib6_walker_list,
99 };
100
101 #define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next)
102
103 static inline void fib6_walker_link(struct fib6_walker_t *w)
104 {
105         write_lock_bh(&fib6_walker_lock);
106         w->next = fib6_walker_list.next;
107         w->prev = &fib6_walker_list;
108         w->next->prev = w;
109         w->prev->next = w;
110         write_unlock_bh(&fib6_walker_lock);
111 }
112
113 static inline void fib6_walker_unlink(struct fib6_walker_t *w)
114 {
115         write_lock_bh(&fib6_walker_lock);
116         w->next->prev = w->prev;
117         w->prev->next = w->next;
118         w->prev = w->next = w;
119         write_unlock_bh(&fib6_walker_lock);
120 }
121 static __inline__ u32 fib6_new_sernum(void)
122 {
123         u32 n = ++rt_sernum;
124         if ((__s32)n <= 0)
125                 rt_sernum = n = 1;
126         return n;
127 }
128
129 /*
130  *      Auxiliary address test functions for the radix tree.
131  *
132  *      These assume a 32bit processor (although it will work on
133  *      64bit processors)
134  */
135
136 /*
137  *      test bit
138  */
139
140 static __inline__ __be32 addr_bit_set(void *token, int fn_bit)
141 {
142         __be32 *addr = token;
143
144         return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5];
145 }
146
147 static __inline__ struct fib6_node * node_alloc(void)
148 {
149         struct fib6_node *fn;
150
151         fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
152
153         return fn;
154 }
155
156 static __inline__ void node_free(struct fib6_node * fn)
157 {
158         kmem_cache_free(fib6_node_kmem, fn);
159 }
160
161 static __inline__ void rt6_release(struct rt6_info *rt)
162 {
163         if (atomic_dec_and_test(&rt->rt6i_ref))
164                 dst_free(&rt->u.dst);
165 }
166
167 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
168 #define FIB_TABLE_HASHSZ 256
169 #else
170 #define FIB_TABLE_HASHSZ 1
171 #endif
172
173 static void fib6_link_table(struct net *net, struct fib6_table *tb)
174 {
175         unsigned int h;
176
177         /*
178          * Initialize table lock at a single place to give lockdep a key,
179          * tables aren't visible prior to being linked to the list.
180          */
181         rwlock_init(&tb->tb6_lock);
182
183         h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1);
184
185         /*
186          * No protection necessary, this is the only list mutatation
187          * operation, tables never disappear once they exist.
188          */
189         hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
190 }
191
192 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
193
194 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
195 {
196         struct fib6_table *table;
197
198         table = kzalloc(sizeof(*table), GFP_ATOMIC);
199         if (table != NULL) {
200                 table->tb6_id = id;
201                 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
202                 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
203         }
204
205         return table;
206 }
207
208 struct fib6_table *fib6_new_table(struct net *net, u32 id)
209 {
210         struct fib6_table *tb;
211
212         if (id == 0)
213                 id = RT6_TABLE_MAIN;
214         tb = fib6_get_table(net, id);
215         if (tb)
216                 return tb;
217
218         tb = fib6_alloc_table(net, id);
219         if (tb != NULL)
220                 fib6_link_table(net, tb);
221
222         return tb;
223 }
224
225 struct fib6_table *fib6_get_table(struct net *net, u32 id)
226 {
227         struct fib6_table *tb;
228         struct hlist_head *head;
229         struct hlist_node *node;
230         unsigned int h;
231
232         if (id == 0)
233                 id = RT6_TABLE_MAIN;
234         h = id & (FIB_TABLE_HASHSZ - 1);
235         rcu_read_lock();
236         head = &net->ipv6.fib_table_hash[h];
237         hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
238                 if (tb->tb6_id == id) {
239                         rcu_read_unlock();
240                         return tb;
241                 }
242         }
243         rcu_read_unlock();
244
245         return NULL;
246 }
247
248 static void fib6_tables_init(struct net *net)
249 {
250         fib6_link_table(net, net->ipv6.fib6_main_tbl);
251         fib6_link_table(net, net->ipv6.fib6_local_tbl);
252 }
253 #else
254
255 struct fib6_table *fib6_new_table(struct net *net, u32 id)
256 {
257         return fib6_get_table(net, id);
258 }
259
260 struct fib6_table *fib6_get_table(struct net *net, u32 id)
261 {
262           return net->ipv6.fib6_main_tbl;
263 }
264
265 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
266                                    int flags, pol_lookup_t lookup)
267 {
268         return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl, flags);
269 }
270
271 static void fib6_tables_init(struct net *net)
272 {
273         fib6_link_table(net, net->ipv6.fib6_main_tbl);
274 }
275
276 #endif
277
278 static int fib6_dump_node(struct fib6_walker_t *w)
279 {
280         int res;
281         struct rt6_info *rt;
282
283         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
284                 res = rt6_dump_route(rt, w->args);
285                 if (res < 0) {
286                         /* Frame is full, suspend walking */
287                         w->leaf = rt;
288                         return 1;
289                 }
290                 WARN_ON(res == 0);
291         }
292         w->leaf = NULL;
293         return 0;
294 }
295
296 static void fib6_dump_end(struct netlink_callback *cb)
297 {
298         struct fib6_walker_t *w = (void*)cb->args[2];
299
300         if (w) {
301                 cb->args[2] = 0;
302                 kfree(w);
303         }
304         cb->done = (void*)cb->args[3];
305         cb->args[1] = 3;
306 }
307
308 static int fib6_dump_done(struct netlink_callback *cb)
309 {
310         fib6_dump_end(cb);
311         return cb->done ? cb->done(cb) : 0;
312 }
313
314 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
315                            struct netlink_callback *cb)
316 {
317         struct fib6_walker_t *w;
318         int res;
319
320         w = (void *)cb->args[2];
321         w->root = &table->tb6_root;
322
323         if (cb->args[4] == 0) {
324                 read_lock_bh(&table->tb6_lock);
325                 res = fib6_walk(w);
326                 read_unlock_bh(&table->tb6_lock);
327                 if (res > 0)
328                         cb->args[4] = 1;
329         } else {
330                 read_lock_bh(&table->tb6_lock);
331                 res = fib6_walk_continue(w);
332                 read_unlock_bh(&table->tb6_lock);
333                 if (res != 0) {
334                         if (res < 0)
335                                 fib6_walker_unlink(w);
336                         goto end;
337                 }
338                 fib6_walker_unlink(w);
339                 cb->args[4] = 0;
340         }
341 end:
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 < FIB_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 = w->func(w);
1259                                 if (err)
1260                                         return err;
1261                                 continue;
1262                         }
1263                         w->state = FWS_U;
1264                 case FWS_U:
1265                         if (fn == w->root)
1266                                 return 0;
1267                         pn = fn->parent;
1268                         w->node = pn;
1269 #ifdef CONFIG_IPV6_SUBTREES
1270                         if (FIB6_SUBTREE(pn) == fn) {
1271                                 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1272                                 w->state = FWS_L;
1273                                 continue;
1274                         }
1275 #endif
1276                         if (pn->left == fn) {
1277                                 w->state = FWS_R;
1278                                 continue;
1279                         }
1280                         if (pn->right == fn) {
1281                                 w->state = FWS_C;
1282                                 w->leaf = w->node->leaf;
1283                                 continue;
1284                         }
1285 #if RT6_DEBUG >= 2
1286                         WARN_ON(1);
1287 #endif
1288                 }
1289         }
1290 }
1291
1292 static int fib6_walk(struct fib6_walker_t *w)
1293 {
1294         int res;
1295
1296         w->state = FWS_INIT;
1297         w->node = w->root;
1298
1299         fib6_walker_link(w);
1300         res = fib6_walk_continue(w);
1301         if (res <= 0)
1302                 fib6_walker_unlink(w);
1303         return res;
1304 }
1305
1306 static int fib6_clean_node(struct fib6_walker_t *w)
1307 {
1308         int res;
1309         struct rt6_info *rt;
1310         struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1311         struct nl_info info = {
1312                 .nl_net = c->net,
1313         };
1314
1315         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
1316                 res = c->func(rt, c->arg);
1317                 if (res < 0) {
1318                         w->leaf = rt;
1319                         res = fib6_del(rt, &info);
1320                         if (res) {
1321 #if RT6_DEBUG >= 2
1322                                 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1323 #endif
1324                                 continue;
1325                         }
1326                         return 0;
1327                 }
1328                 WARN_ON(res != 0);
1329         }
1330         w->leaf = rt;
1331         return 0;
1332 }
1333
1334 /*
1335  *      Convenient frontend to tree walker.
1336  *
1337  *      func is called on each route.
1338  *              It may return -1 -> delete this route.
1339  *                            0  -> continue walking
1340  *
1341  *      prune==1 -> only immediate children of node (certainly,
1342  *      ignoring pure split nodes) will be scanned.
1343  */
1344
1345 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1346                             int (*func)(struct rt6_info *, void *arg),
1347                             int prune, void *arg)
1348 {
1349         struct fib6_cleaner_t c;
1350
1351         c.w.root = root;
1352         c.w.func = fib6_clean_node;
1353         c.w.prune = prune;
1354         c.func = func;
1355         c.arg = arg;
1356         c.net = net;
1357
1358         fib6_walk(&c.w);
1359 }
1360
1361 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1362                     int prune, void *arg)
1363 {
1364         struct fib6_table *table;
1365         struct hlist_node *node;
1366         struct hlist_head *head;
1367         unsigned int h;
1368
1369         rcu_read_lock();
1370         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
1371                 head = &net->ipv6.fib_table_hash[h];
1372                 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1373                         write_lock_bh(&table->tb6_lock);
1374                         fib6_clean_tree(net, &table->tb6_root,
1375                                         func, prune, arg);
1376                         write_unlock_bh(&table->tb6_lock);
1377                 }
1378         }
1379         rcu_read_unlock();
1380 }
1381
1382 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1383 {
1384         if (rt->rt6i_flags & RTF_CACHE) {
1385                 RT6_TRACE("pruning clone %p\n", rt);
1386                 return -1;
1387         }
1388
1389         return 0;
1390 }
1391
1392 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1393                               struct rt6_info *rt)
1394 {
1395         fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1396 }
1397
1398 /*
1399  *      Garbage collection
1400  */
1401
1402 static struct fib6_gc_args
1403 {
1404         int                     timeout;
1405         int                     more;
1406 } gc_args;
1407
1408 static int fib6_age(struct rt6_info *rt, void *arg)
1409 {
1410         unsigned long now = jiffies;
1411
1412         /*
1413          *      check addrconf expiration here.
1414          *      Routes are expired even if they are in use.
1415          *
1416          *      Also age clones. Note, that clones are aged out
1417          *      only if they are not in use now.
1418          */
1419
1420         if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1421                 if (time_after(now, rt->rt6i_expires)) {
1422                         RT6_TRACE("expiring %p\n", rt);
1423                         return -1;
1424                 }
1425                 gc_args.more++;
1426         } else if (rt->rt6i_flags & RTF_CACHE) {
1427                 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1428                     time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1429                         RT6_TRACE("aging clone %p\n", rt);
1430                         return -1;
1431                 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1432                            (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1433                         RT6_TRACE("purging route %p via non-router but gateway\n",
1434                                   rt);
1435                         return -1;
1436                 }
1437                 gc_args.more++;
1438         }
1439
1440         return 0;
1441 }
1442
1443 static DEFINE_SPINLOCK(fib6_gc_lock);
1444
1445 void fib6_run_gc(unsigned long expires, struct net *net)
1446 {
1447         if (expires != ~0UL) {
1448                 spin_lock_bh(&fib6_gc_lock);
1449                 gc_args.timeout = expires ? (int)expires :
1450                         net->ipv6.sysctl.ip6_rt_gc_interval;
1451         } else {
1452                 if (!spin_trylock_bh(&fib6_gc_lock)) {
1453                         mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1454                         return;
1455                 }
1456                 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1457         }
1458
1459         gc_args.more = icmp6_dst_gc();
1460
1461         fib6_clean_all(net, fib6_age, 0, NULL);
1462
1463         if (gc_args.more)
1464                 mod_timer(&net->ipv6.ip6_fib_timer,
1465                           round_jiffies(jiffies
1466                                         + net->ipv6.sysctl.ip6_rt_gc_interval));
1467         else
1468                 del_timer(&net->ipv6.ip6_fib_timer);
1469         spin_unlock_bh(&fib6_gc_lock);
1470 }
1471
1472 static void fib6_gc_timer_cb(unsigned long arg)
1473 {
1474         fib6_run_gc(0, (struct net *)arg);
1475 }
1476
1477 static int fib6_net_init(struct net *net)
1478 {
1479         setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1480
1481         net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1482         if (!net->ipv6.rt6_stats)
1483                 goto out_timer;
1484
1485         net->ipv6.fib_table_hash = kcalloc(FIB_TABLE_HASHSZ,
1486                                            sizeof(*net->ipv6.fib_table_hash),
1487                                            GFP_KERNEL);
1488         if (!net->ipv6.fib_table_hash)
1489                 goto out_rt6_stats;
1490
1491         net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1492                                           GFP_KERNEL);
1493         if (!net->ipv6.fib6_main_tbl)
1494                 goto out_fib_table_hash;
1495
1496         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1497         net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1498         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1499                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1500
1501 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1502         net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1503                                            GFP_KERNEL);
1504         if (!net->ipv6.fib6_local_tbl)
1505                 goto out_fib6_main_tbl;
1506         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1507         net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1508         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1509                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1510 #endif
1511         fib6_tables_init(net);
1512
1513         return 0;
1514
1515 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1516 out_fib6_main_tbl:
1517         kfree(net->ipv6.fib6_main_tbl);
1518 #endif
1519 out_fib_table_hash:
1520         kfree(net->ipv6.fib_table_hash);
1521 out_rt6_stats:
1522         kfree(net->ipv6.rt6_stats);
1523 out_timer:
1524         return -ENOMEM;
1525  }
1526
1527 static void fib6_net_exit(struct net *net)
1528 {
1529         rt6_ifdown(net, NULL);
1530         del_timer_sync(&net->ipv6.ip6_fib_timer);
1531
1532 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1533         kfree(net->ipv6.fib6_local_tbl);
1534 #endif
1535         kfree(net->ipv6.fib6_main_tbl);
1536         kfree(net->ipv6.fib_table_hash);
1537         kfree(net->ipv6.rt6_stats);
1538 }
1539
1540 static struct pernet_operations fib6_net_ops = {
1541         .init = fib6_net_init,
1542         .exit = fib6_net_exit,
1543 };
1544
1545 int __init fib6_init(void)
1546 {
1547         int ret = -ENOMEM;
1548
1549         fib6_node_kmem = kmem_cache_create("fib6_nodes",
1550                                            sizeof(struct fib6_node),
1551                                            0, SLAB_HWCACHE_ALIGN,
1552                                            NULL);
1553         if (!fib6_node_kmem)
1554                 goto out;
1555
1556         ret = register_pernet_subsys(&fib6_net_ops);
1557         if (ret)
1558                 goto out_kmem_cache_create;
1559
1560         ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib);
1561         if (ret)
1562                 goto out_unregister_subsys;
1563 out:
1564         return ret;
1565
1566 out_unregister_subsys:
1567         unregister_pernet_subsys(&fib6_net_ops);
1568 out_kmem_cache_create:
1569         kmem_cache_destroy(fib6_node_kmem);
1570         goto out;
1571 }
1572
1573 void fib6_gc_cleanup(void)
1574 {
1575         unregister_pernet_subsys(&fib6_net_ops);
1576         kmem_cache_destroy(fib6_node_kmem);
1577 }