08ea2de28d63c358eeec0a3b59469914dd3fca4b
[linux-3.10.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                 BUG_TRAP(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         w->args = &arg;
382
383         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
384                 e = 0;
385                 head = &net->ipv6.fib_table_hash[h];
386                 hlist_for_each_entry(tb, node, head, tb6_hlist) {
387                         if (e < s_e)
388                                 goto next;
389                         res = fib6_dump_table(tb, skb, cb);
390                         if (res != 0)
391                                 goto out;
392 next:
393                         e++;
394                 }
395         }
396 out:
397         cb->args[1] = e;
398         cb->args[0] = h;
399
400         res = res < 0 ? res : skb->len;
401         if (res <= 0)
402                 fib6_dump_end(cb);
403         return res;
404 }
405
406 /*
407  *      Routing Table
408  *
409  *      return the appropriate node for a routing tree "add" operation
410  *      by either creating and inserting or by returning an existing
411  *      node.
412  */
413
414 static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
415                                      int addrlen, int plen,
416                                      int offset)
417 {
418         struct fib6_node *fn, *in, *ln;
419         struct fib6_node *pn = NULL;
420         struct rt6key *key;
421         int     bit;
422         __be32  dir = 0;
423         __u32   sernum = fib6_new_sernum();
424
425         RT6_TRACE("fib6_add_1\n");
426
427         /* insert node in tree */
428
429         fn = root;
430
431         do {
432                 key = (struct rt6key *)((u8 *)fn->leaf + offset);
433
434                 /*
435                  *      Prefix match
436                  */
437                 if (plen < fn->fn_bit ||
438                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
439                         goto insert_above;
440
441                 /*
442                  *      Exact match ?
443                  */
444
445                 if (plen == fn->fn_bit) {
446                         /* clean up an intermediate node */
447                         if ((fn->fn_flags & RTN_RTINFO) == 0) {
448                                 rt6_release(fn->leaf);
449                                 fn->leaf = NULL;
450                         }
451
452                         fn->fn_sernum = sernum;
453
454                         return fn;
455                 }
456
457                 /*
458                  *      We have more bits to go
459                  */
460
461                 /* Try to walk down on tree. */
462                 fn->fn_sernum = sernum;
463                 dir = addr_bit_set(addr, fn->fn_bit);
464                 pn = fn;
465                 fn = dir ? fn->right: fn->left;
466         } while (fn);
467
468         /*
469          *      We walked to the bottom of tree.
470          *      Create new leaf node without children.
471          */
472
473         ln = node_alloc();
474
475         if (ln == NULL)
476                 return NULL;
477         ln->fn_bit = plen;
478
479         ln->parent = pn;
480         ln->fn_sernum = sernum;
481
482         if (dir)
483                 pn->right = ln;
484         else
485                 pn->left  = ln;
486
487         return ln;
488
489
490 insert_above:
491         /*
492          * split since we don't have a common prefix anymore or
493          * we have a less significant route.
494          * we've to insert an intermediate node on the list
495          * this new node will point to the one we need to create
496          * and the current
497          */
498
499         pn = fn->parent;
500
501         /* find 1st bit in difference between the 2 addrs.
502
503            See comment in __ipv6_addr_diff: bit may be an invalid value,
504            but if it is >= plen, the value is ignored in any case.
505          */
506
507         bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
508
509         /*
510          *              (intermediate)[in]
511          *                /        \
512          *      (new leaf node)[ln] (old node)[fn]
513          */
514         if (plen > bit) {
515                 in = node_alloc();
516                 ln = node_alloc();
517
518                 if (in == NULL || ln == NULL) {
519                         if (in)
520                                 node_free(in);
521                         if (ln)
522                                 node_free(ln);
523                         return NULL;
524                 }
525
526                 /*
527                  * new intermediate node.
528                  * RTN_RTINFO will
529                  * be off since that an address that chooses one of
530                  * the branches would not match less specific routes
531                  * in the other branch
532                  */
533
534                 in->fn_bit = bit;
535
536                 in->parent = pn;
537                 in->leaf = fn->leaf;
538                 atomic_inc(&in->leaf->rt6i_ref);
539
540                 in->fn_sernum = sernum;
541
542                 /* update parent pointer */
543                 if (dir)
544                         pn->right = in;
545                 else
546                         pn->left  = in;
547
548                 ln->fn_bit = plen;
549
550                 ln->parent = in;
551                 fn->parent = in;
552
553                 ln->fn_sernum = sernum;
554
555                 if (addr_bit_set(addr, bit)) {
556                         in->right = ln;
557                         in->left  = fn;
558                 } else {
559                         in->left  = ln;
560                         in->right = fn;
561                 }
562         } else { /* plen <= bit */
563
564                 /*
565                  *              (new leaf node)[ln]
566                  *                /        \
567                  *           (old node)[fn] NULL
568                  */
569
570                 ln = node_alloc();
571
572                 if (ln == NULL)
573                         return NULL;
574
575                 ln->fn_bit = plen;
576
577                 ln->parent = pn;
578
579                 ln->fn_sernum = sernum;
580
581                 if (dir)
582                         pn->right = ln;
583                 else
584                         pn->left  = ln;
585
586                 if (addr_bit_set(&key->addr, plen))
587                         ln->right = fn;
588                 else
589                         ln->left  = fn;
590
591                 fn->parent = ln;
592         }
593         return ln;
594 }
595
596 /*
597  *      Insert routing information in a node.
598  */
599
600 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
601                             struct nl_info *info)
602 {
603         struct rt6_info *iter = NULL;
604         struct rt6_info **ins;
605
606         ins = &fn->leaf;
607
608         for (iter = fn->leaf; iter; iter=iter->u.dst.rt6_next) {
609                 /*
610                  *      Search for duplicates
611                  */
612
613                 if (iter->rt6i_metric == rt->rt6i_metric) {
614                         /*
615                          *      Same priority level
616                          */
617
618                         if (iter->rt6i_dev == rt->rt6i_dev &&
619                             iter->rt6i_idev == rt->rt6i_idev &&
620                             ipv6_addr_equal(&iter->rt6i_gateway,
621                                             &rt->rt6i_gateway)) {
622                                 if (!(iter->rt6i_flags&RTF_EXPIRES))
623                                         return -EEXIST;
624                                 iter->rt6i_expires = rt->rt6i_expires;
625                                 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
626                                         iter->rt6i_flags &= ~RTF_EXPIRES;
627                                         iter->rt6i_expires = 0;
628                                 }
629                                 return -EEXIST;
630                         }
631                 }
632
633                 if (iter->rt6i_metric > rt->rt6i_metric)
634                         break;
635
636                 ins = &iter->u.dst.rt6_next;
637         }
638
639         /* Reset round-robin state, if necessary */
640         if (ins == &fn->leaf)
641                 fn->rr_ptr = NULL;
642
643         /*
644          *      insert node
645          */
646
647         rt->u.dst.rt6_next = iter;
648         *ins = rt;
649         rt->rt6i_node = fn;
650         atomic_inc(&rt->rt6i_ref);
651         inet6_rt_notify(RTM_NEWROUTE, rt, info);
652         info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
653
654         if ((fn->fn_flags & RTN_RTINFO) == 0) {
655                 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
656                 fn->fn_flags |= RTN_RTINFO;
657         }
658
659         return 0;
660 }
661
662 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
663 {
664         if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
665             (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
666                 mod_timer(&net->ipv6.ip6_fib_timer,
667                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
668 }
669
670 void fib6_force_start_gc(struct net *net)
671 {
672         if (!timer_pending(&net->ipv6.ip6_fib_timer))
673                 mod_timer(&net->ipv6.ip6_fib_timer,
674                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
675 }
676
677 /*
678  *      Add routing information to the routing tree.
679  *      <destination addr>/<source addr>
680  *      with source addr info in sub-trees
681  */
682
683 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
684 {
685         struct fib6_node *fn, *pn = NULL;
686         int err = -ENOMEM;
687
688         fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
689                         rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
690
691         if (fn == NULL)
692                 goto out;
693
694         pn = fn;
695
696 #ifdef CONFIG_IPV6_SUBTREES
697         if (rt->rt6i_src.plen) {
698                 struct fib6_node *sn;
699
700                 if (fn->subtree == NULL) {
701                         struct fib6_node *sfn;
702
703                         /*
704                          * Create subtree.
705                          *
706                          *              fn[main tree]
707                          *              |
708                          *              sfn[subtree root]
709                          *                 \
710                          *                  sn[new leaf node]
711                          */
712
713                         /* Create subtree root node */
714                         sfn = node_alloc();
715                         if (sfn == NULL)
716                                 goto st_failure;
717
718                         sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
719                         atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
720                         sfn->fn_flags = RTN_ROOT;
721                         sfn->fn_sernum = fib6_new_sernum();
722
723                         /* Now add the first leaf node to new subtree */
724
725                         sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
726                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
727                                         offsetof(struct rt6_info, rt6i_src));
728
729                         if (sn == NULL) {
730                                 /* If it is failed, discard just allocated
731                                    root, and then (in st_failure) stale node
732                                    in main tree.
733                                  */
734                                 node_free(sfn);
735                                 goto st_failure;
736                         }
737
738                         /* Now link new subtree to main tree */
739                         sfn->parent = fn;
740                         fn->subtree = sfn;
741                 } else {
742                         sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
743                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
744                                         offsetof(struct rt6_info, rt6i_src));
745
746                         if (sn == NULL)
747                                 goto st_failure;
748                 }
749
750                 if (fn->leaf == NULL) {
751                         fn->leaf = rt;
752                         atomic_inc(&rt->rt6i_ref);
753                 }
754                 fn = sn;
755         }
756 #endif
757
758         err = fib6_add_rt2node(fn, rt, info);
759
760         if (err == 0) {
761                 fib6_start_gc(info->nl_net, rt);
762                 if (!(rt->rt6i_flags&RTF_CACHE))
763                         fib6_prune_clones(info->nl_net, pn, rt);
764         }
765
766 out:
767         if (err) {
768 #ifdef CONFIG_IPV6_SUBTREES
769                 /*
770                  * If fib6_add_1 has cleared the old leaf pointer in the
771                  * super-tree leaf node we have to find a new one for it.
772                  */
773                 if (pn != fn && pn->leaf == rt) {
774                         pn->leaf = NULL;
775                         atomic_dec(&rt->rt6i_ref);
776                 }
777                 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
778                         pn->leaf = fib6_find_prefix(info->nl_net, pn);
779 #if RT6_DEBUG >= 2
780                         if (!pn->leaf) {
781                                 BUG_TRAP(pn->leaf != NULL);
782                                 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
783                         }
784 #endif
785                         atomic_inc(&pn->leaf->rt6i_ref);
786                 }
787 #endif
788                 dst_free(&rt->u.dst);
789         }
790         return err;
791
792 #ifdef CONFIG_IPV6_SUBTREES
793         /* Subtree creation failed, probably main tree node
794            is orphan. If it is, shoot it.
795          */
796 st_failure:
797         if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
798                 fib6_repair_tree(info->nl_net, fn);
799         dst_free(&rt->u.dst);
800         return err;
801 #endif
802 }
803
804 /*
805  *      Routing tree lookup
806  *
807  */
808
809 struct lookup_args {
810         int             offset;         /* key offset on rt6_info       */
811         struct in6_addr *addr;          /* search key                   */
812 };
813
814 static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
815                                         struct lookup_args *args)
816 {
817         struct fib6_node *fn;
818         __be32 dir;
819
820         if (unlikely(args->offset == 0))
821                 return NULL;
822
823         /*
824          *      Descend on a tree
825          */
826
827         fn = root;
828
829         for (;;) {
830                 struct fib6_node *next;
831
832                 dir = addr_bit_set(args->addr, fn->fn_bit);
833
834                 next = dir ? fn->right : fn->left;
835
836                 if (next) {
837                         fn = next;
838                         continue;
839                 }
840
841                 break;
842         }
843
844         while(fn) {
845                 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
846                         struct rt6key *key;
847
848                         key = (struct rt6key *) ((u8 *) fn->leaf +
849                                                  args->offset);
850
851                         if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
852 #ifdef CONFIG_IPV6_SUBTREES
853                                 if (fn->subtree)
854                                         fn = fib6_lookup_1(fn->subtree, args + 1);
855 #endif
856                                 if (!fn || fn->fn_flags & RTN_RTINFO)
857                                         return fn;
858                         }
859                 }
860
861                 if (fn->fn_flags & RTN_ROOT)
862                         break;
863
864                 fn = fn->parent;
865         }
866
867         return NULL;
868 }
869
870 struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr,
871                                struct in6_addr *saddr)
872 {
873         struct fib6_node *fn;
874         struct lookup_args args[] = {
875                 {
876                         .offset = offsetof(struct rt6_info, rt6i_dst),
877                         .addr = daddr,
878                 },
879 #ifdef CONFIG_IPV6_SUBTREES
880                 {
881                         .offset = offsetof(struct rt6_info, rt6i_src),
882                         .addr = saddr,
883                 },
884 #endif
885                 {
886                         .offset = 0,    /* sentinel */
887                 }
888         };
889
890         fn = fib6_lookup_1(root, daddr ? args : args + 1);
891
892         if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
893                 fn = root;
894
895         return fn;
896 }
897
898 /*
899  *      Get node with specified destination prefix (and source prefix,
900  *      if subtrees are used)
901  */
902
903
904 static struct fib6_node * fib6_locate_1(struct fib6_node *root,
905                                         struct in6_addr *addr,
906                                         int plen, int offset)
907 {
908         struct fib6_node *fn;
909
910         for (fn = root; fn ; ) {
911                 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
912
913                 /*
914                  *      Prefix match
915                  */
916                 if (plen < fn->fn_bit ||
917                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
918                         return NULL;
919
920                 if (plen == fn->fn_bit)
921                         return fn;
922
923                 /*
924                  *      We have more bits to go
925                  */
926                 if (addr_bit_set(addr, fn->fn_bit))
927                         fn = fn->right;
928                 else
929                         fn = fn->left;
930         }
931         return NULL;
932 }
933
934 struct fib6_node * fib6_locate(struct fib6_node *root,
935                                struct in6_addr *daddr, int dst_len,
936                                struct in6_addr *saddr, int src_len)
937 {
938         struct fib6_node *fn;
939
940         fn = fib6_locate_1(root, daddr, dst_len,
941                            offsetof(struct rt6_info, rt6i_dst));
942
943 #ifdef CONFIG_IPV6_SUBTREES
944         if (src_len) {
945                 BUG_TRAP(saddr!=NULL);
946                 if (fn && fn->subtree)
947                         fn = fib6_locate_1(fn->subtree, saddr, src_len,
948                                            offsetof(struct rt6_info, rt6i_src));
949         }
950 #endif
951
952         if (fn && fn->fn_flags&RTN_RTINFO)
953                 return fn;
954
955         return NULL;
956 }
957
958
959 /*
960  *      Deletion
961  *
962  */
963
964 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
965 {
966         if (fn->fn_flags&RTN_ROOT)
967                 return net->ipv6.ip6_null_entry;
968
969         while(fn) {
970                 if(fn->left)
971                         return fn->left->leaf;
972
973                 if(fn->right)
974                         return fn->right->leaf;
975
976                 fn = FIB6_SUBTREE(fn);
977         }
978         return NULL;
979 }
980
981 /*
982  *      Called to trim the tree of intermediate nodes when possible. "fn"
983  *      is the node we want to try and remove.
984  */
985
986 static struct fib6_node *fib6_repair_tree(struct net *net,
987                                            struct fib6_node *fn)
988 {
989         int children;
990         int nstate;
991         struct fib6_node *child, *pn;
992         struct fib6_walker_t *w;
993         int iter = 0;
994
995         for (;;) {
996                 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
997                 iter++;
998
999                 BUG_TRAP(!(fn->fn_flags&RTN_RTINFO));
1000                 BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT));
1001                 BUG_TRAP(fn->leaf==NULL);
1002
1003                 children = 0;
1004                 child = NULL;
1005                 if (fn->right) child = fn->right, children |= 1;
1006                 if (fn->left) child = fn->left, children |= 2;
1007
1008                 if (children == 3 || FIB6_SUBTREE(fn)
1009 #ifdef CONFIG_IPV6_SUBTREES
1010                     /* Subtree root (i.e. fn) may have one child */
1011                     || (children && fn->fn_flags&RTN_ROOT)
1012 #endif
1013                     ) {
1014                         fn->leaf = fib6_find_prefix(net, fn);
1015 #if RT6_DEBUG >= 2
1016                         if (fn->leaf==NULL) {
1017                                 BUG_TRAP(fn->leaf);
1018                                 fn->leaf = net->ipv6.ip6_null_entry;
1019                         }
1020 #endif
1021                         atomic_inc(&fn->leaf->rt6i_ref);
1022                         return fn->parent;
1023                 }
1024
1025                 pn = fn->parent;
1026 #ifdef CONFIG_IPV6_SUBTREES
1027                 if (FIB6_SUBTREE(pn) == fn) {
1028                         BUG_TRAP(fn->fn_flags&RTN_ROOT);
1029                         FIB6_SUBTREE(pn) = NULL;
1030                         nstate = FWS_L;
1031                 } else {
1032                         BUG_TRAP(!(fn->fn_flags&RTN_ROOT));
1033 #endif
1034                         if (pn->right == fn) pn->right = child;
1035                         else if (pn->left == fn) pn->left = child;
1036 #if RT6_DEBUG >= 2
1037                         else BUG_TRAP(0);
1038 #endif
1039                         if (child)
1040                                 child->parent = pn;
1041                         nstate = FWS_R;
1042 #ifdef CONFIG_IPV6_SUBTREES
1043                 }
1044 #endif
1045
1046                 read_lock(&fib6_walker_lock);
1047                 FOR_WALKERS(w) {
1048                         if (child == NULL) {
1049                                 if (w->root == fn) {
1050                                         w->root = w->node = NULL;
1051                                         RT6_TRACE("W %p adjusted by delroot 1\n", w);
1052                                 } else if (w->node == fn) {
1053                                         RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1054                                         w->node = pn;
1055                                         w->state = nstate;
1056                                 }
1057                         } else {
1058                                 if (w->root == fn) {
1059                                         w->root = child;
1060                                         RT6_TRACE("W %p adjusted by delroot 2\n", w);
1061                                 }
1062                                 if (w->node == fn) {
1063                                         w->node = child;
1064                                         if (children&2) {
1065                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1066                                                 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1067                                         } else {
1068                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1069                                                 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1070                                         }
1071                                 }
1072                         }
1073                 }
1074                 read_unlock(&fib6_walker_lock);
1075
1076                 node_free(fn);
1077                 if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn))
1078                         return pn;
1079
1080                 rt6_release(pn->leaf);
1081                 pn->leaf = NULL;
1082                 fn = pn;
1083         }
1084 }
1085
1086 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1087                            struct nl_info *info)
1088 {
1089         struct fib6_walker_t *w;
1090         struct rt6_info *rt = *rtp;
1091         struct net *net = info->nl_net;
1092
1093         RT6_TRACE("fib6_del_route\n");
1094
1095         /* Unlink it */
1096         *rtp = rt->u.dst.rt6_next;
1097         rt->rt6i_node = NULL;
1098         net->ipv6.rt6_stats->fib_rt_entries--;
1099         net->ipv6.rt6_stats->fib_discarded_routes++;
1100
1101         /* Reset round-robin state, if necessary */
1102         if (fn->rr_ptr == rt)
1103                 fn->rr_ptr = NULL;
1104
1105         /* Adjust walkers */
1106         read_lock(&fib6_walker_lock);
1107         FOR_WALKERS(w) {
1108                 if (w->state == FWS_C && w->leaf == rt) {
1109                         RT6_TRACE("walker %p adjusted by delroute\n", w);
1110                         w->leaf = rt->u.dst.rt6_next;
1111                         if (w->leaf == NULL)
1112                                 w->state = FWS_U;
1113                 }
1114         }
1115         read_unlock(&fib6_walker_lock);
1116
1117         rt->u.dst.rt6_next = NULL;
1118
1119         /* If it was last route, expunge its radix tree node */
1120         if (fn->leaf == NULL) {
1121                 fn->fn_flags &= ~RTN_RTINFO;
1122                 net->ipv6.rt6_stats->fib_route_nodes--;
1123                 fn = fib6_repair_tree(net, fn);
1124         }
1125
1126         if (atomic_read(&rt->rt6i_ref) != 1) {
1127                 /* This route is used as dummy address holder in some split
1128                  * nodes. It is not leaked, but it still holds other resources,
1129                  * which must be released in time. So, scan ascendant nodes
1130                  * and replace dummy references to this route with references
1131                  * to still alive ones.
1132                  */
1133                 while (fn) {
1134                         if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
1135                                 fn->leaf = fib6_find_prefix(net, fn);
1136                                 atomic_inc(&fn->leaf->rt6i_ref);
1137                                 rt6_release(rt);
1138                         }
1139                         fn = fn->parent;
1140                 }
1141                 /* No more references are possible at this point. */
1142                 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1143         }
1144
1145         inet6_rt_notify(RTM_DELROUTE, rt, info);
1146         rt6_release(rt);
1147 }
1148
1149 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1150 {
1151         struct net *net = info->nl_net;
1152         struct fib6_node *fn = rt->rt6i_node;
1153         struct rt6_info **rtp;
1154
1155 #if RT6_DEBUG >= 2
1156         if (rt->u.dst.obsolete>0) {
1157                 BUG_TRAP(fn==NULL);
1158                 return -ENOENT;
1159         }
1160 #endif
1161         if (fn == NULL || rt == net->ipv6.ip6_null_entry)
1162                 return -ENOENT;
1163
1164         BUG_TRAP(fn->fn_flags&RTN_RTINFO);
1165
1166         if (!(rt->rt6i_flags&RTF_CACHE)) {
1167                 struct fib6_node *pn = fn;
1168 #ifdef CONFIG_IPV6_SUBTREES
1169                 /* clones of this route might be in another subtree */
1170                 if (rt->rt6i_src.plen) {
1171                         while (!(pn->fn_flags&RTN_ROOT))
1172                                 pn = pn->parent;
1173                         pn = pn->parent;
1174                 }
1175 #endif
1176                 fib6_prune_clones(info->nl_net, pn, rt);
1177         }
1178
1179         /*
1180          *      Walk the leaf entries looking for ourself
1181          */
1182
1183         for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.dst.rt6_next) {
1184                 if (*rtp == rt) {
1185                         fib6_del_route(fn, rtp, info);
1186                         return 0;
1187                 }
1188         }
1189         return -ENOENT;
1190 }
1191
1192 /*
1193  *      Tree traversal function.
1194  *
1195  *      Certainly, it is not interrupt safe.
1196  *      However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1197  *      It means, that we can modify tree during walking
1198  *      and use this function for garbage collection, clone pruning,
1199  *      cleaning tree when a device goes down etc. etc.
1200  *
1201  *      It guarantees that every node will be traversed,
1202  *      and that it will be traversed only once.
1203  *
1204  *      Callback function w->func may return:
1205  *      0 -> continue walking.
1206  *      positive value -> walking is suspended (used by tree dumps,
1207  *      and probably by gc, if it will be split to several slices)
1208  *      negative value -> terminate walking.
1209  *
1210  *      The function itself returns:
1211  *      0   -> walk is complete.
1212  *      >0  -> walk is incomplete (i.e. suspended)
1213  *      <0  -> walk is terminated by an error.
1214  */
1215
1216 static int fib6_walk_continue(struct fib6_walker_t *w)
1217 {
1218         struct fib6_node *fn, *pn;
1219
1220         for (;;) {
1221                 fn = w->node;
1222                 if (fn == NULL)
1223                         return 0;
1224
1225                 if (w->prune && fn != w->root &&
1226                     fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1227                         w->state = FWS_C;
1228                         w->leaf = fn->leaf;
1229                 }
1230                 switch (w->state) {
1231 #ifdef CONFIG_IPV6_SUBTREES
1232                 case FWS_S:
1233                         if (FIB6_SUBTREE(fn)) {
1234                                 w->node = FIB6_SUBTREE(fn);
1235                                 continue;
1236                         }
1237                         w->state = FWS_L;
1238 #endif
1239                 case FWS_L:
1240                         if (fn->left) {
1241                                 w->node = fn->left;
1242                                 w->state = FWS_INIT;
1243                                 continue;
1244                         }
1245                         w->state = FWS_R;
1246                 case FWS_R:
1247                         if (fn->right) {
1248                                 w->node = fn->right;
1249                                 w->state = FWS_INIT;
1250                                 continue;
1251                         }
1252                         w->state = FWS_C;
1253                         w->leaf = fn->leaf;
1254                 case FWS_C:
1255                         if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1256                                 int err = w->func(w);
1257                                 if (err)
1258                                         return err;
1259                                 continue;
1260                         }
1261                         w->state = FWS_U;
1262                 case FWS_U:
1263                         if (fn == w->root)
1264                                 return 0;
1265                         pn = fn->parent;
1266                         w->node = pn;
1267 #ifdef CONFIG_IPV6_SUBTREES
1268                         if (FIB6_SUBTREE(pn) == fn) {
1269                                 BUG_TRAP(fn->fn_flags&RTN_ROOT);
1270                                 w->state = FWS_L;
1271                                 continue;
1272                         }
1273 #endif
1274                         if (pn->left == fn) {
1275                                 w->state = FWS_R;
1276                                 continue;
1277                         }
1278                         if (pn->right == fn) {
1279                                 w->state = FWS_C;
1280                                 w->leaf = w->node->leaf;
1281                                 continue;
1282                         }
1283 #if RT6_DEBUG >= 2
1284                         BUG_TRAP(0);
1285 #endif
1286                 }
1287         }
1288 }
1289
1290 static int fib6_walk(struct fib6_walker_t *w)
1291 {
1292         int res;
1293
1294         w->state = FWS_INIT;
1295         w->node = w->root;
1296
1297         fib6_walker_link(w);
1298         res = fib6_walk_continue(w);
1299         if (res <= 0)
1300                 fib6_walker_unlink(w);
1301         return res;
1302 }
1303
1304 static int fib6_clean_node(struct fib6_walker_t *w)
1305 {
1306         int res;
1307         struct rt6_info *rt;
1308         struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1309         struct nl_info info = {
1310                 .nl_net = c->net,
1311         };
1312
1313         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
1314                 res = c->func(rt, c->arg);
1315                 if (res < 0) {
1316                         w->leaf = rt;
1317                         res = fib6_del(rt, &info);
1318                         if (res) {
1319 #if RT6_DEBUG >= 2
1320                                 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1321 #endif
1322                                 continue;
1323                         }
1324                         return 0;
1325                 }
1326                 BUG_TRAP(res==0);
1327         }
1328         w->leaf = rt;
1329         return 0;
1330 }
1331
1332 /*
1333  *      Convenient frontend to tree walker.
1334  *
1335  *      func is called on each route.
1336  *              It may return -1 -> delete this route.
1337  *                            0  -> continue walking
1338  *
1339  *      prune==1 -> only immediate children of node (certainly,
1340  *      ignoring pure split nodes) will be scanned.
1341  */
1342
1343 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1344                             int (*func)(struct rt6_info *, void *arg),
1345                             int prune, void *arg)
1346 {
1347         struct fib6_cleaner_t c;
1348
1349         c.w.root = root;
1350         c.w.func = fib6_clean_node;
1351         c.w.prune = prune;
1352         c.func = func;
1353         c.arg = arg;
1354         c.net = net;
1355
1356         fib6_walk(&c.w);
1357 }
1358
1359 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1360                     int prune, void *arg)
1361 {
1362         struct fib6_table *table;
1363         struct hlist_node *node;
1364         struct hlist_head *head;
1365         unsigned int h;
1366
1367         rcu_read_lock();
1368         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
1369                 head = &net->ipv6.fib_table_hash[h];
1370                 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1371                         write_lock_bh(&table->tb6_lock);
1372                         fib6_clean_tree(net, &table->tb6_root,
1373                                         func, prune, arg);
1374                         write_unlock_bh(&table->tb6_lock);
1375                 }
1376         }
1377         rcu_read_unlock();
1378 }
1379
1380 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1381 {
1382         if (rt->rt6i_flags & RTF_CACHE) {
1383                 RT6_TRACE("pruning clone %p\n", rt);
1384                 return -1;
1385         }
1386
1387         return 0;
1388 }
1389
1390 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1391                               struct rt6_info *rt)
1392 {
1393         fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1394 }
1395
1396 /*
1397  *      Garbage collection
1398  */
1399
1400 static struct fib6_gc_args
1401 {
1402         int                     timeout;
1403         int                     more;
1404 } gc_args;
1405
1406 static int fib6_age(struct rt6_info *rt, void *arg)
1407 {
1408         unsigned long now = jiffies;
1409
1410         /*
1411          *      check addrconf expiration here.
1412          *      Routes are expired even if they are in use.
1413          *
1414          *      Also age clones. Note, that clones are aged out
1415          *      only if they are not in use now.
1416          */
1417
1418         if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1419                 if (time_after(now, rt->rt6i_expires)) {
1420                         RT6_TRACE("expiring %p\n", rt);
1421                         return -1;
1422                 }
1423                 gc_args.more++;
1424         } else if (rt->rt6i_flags & RTF_CACHE) {
1425                 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1426                     time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1427                         RT6_TRACE("aging clone %p\n", rt);
1428                         return -1;
1429                 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1430                            (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1431                         RT6_TRACE("purging route %p via non-router but gateway\n",
1432                                   rt);
1433                         return -1;
1434                 }
1435                 gc_args.more++;
1436         }
1437
1438         return 0;
1439 }
1440
1441 static DEFINE_SPINLOCK(fib6_gc_lock);
1442
1443 void fib6_run_gc(unsigned long expires, struct net *net)
1444 {
1445         if (expires != ~0UL) {
1446                 spin_lock_bh(&fib6_gc_lock);
1447                 gc_args.timeout = expires ? (int)expires :
1448                         net->ipv6.sysctl.ip6_rt_gc_interval;
1449         } else {
1450                 if (!spin_trylock_bh(&fib6_gc_lock)) {
1451                         mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1452                         return;
1453                 }
1454                 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1455         }
1456
1457         gc_args.more = icmp6_dst_gc();
1458
1459         fib6_clean_all(net, fib6_age, 0, NULL);
1460
1461         if (gc_args.more)
1462                 mod_timer(&net->ipv6.ip6_fib_timer,
1463                           round_jiffies(jiffies
1464                                         + net->ipv6.sysctl.ip6_rt_gc_interval));
1465         else
1466                 del_timer(&net->ipv6.ip6_fib_timer);
1467         spin_unlock_bh(&fib6_gc_lock);
1468 }
1469
1470 static void fib6_gc_timer_cb(unsigned long arg)
1471 {
1472         fib6_run_gc(0, (struct net *)arg);
1473 }
1474
1475 static int fib6_net_init(struct net *net)
1476 {
1477         setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1478
1479         net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1480         if (!net->ipv6.rt6_stats)
1481                 goto out_timer;
1482
1483         net->ipv6.fib_table_hash = kcalloc(FIB_TABLE_HASHSZ,
1484                                            sizeof(*net->ipv6.fib_table_hash),
1485                                            GFP_KERNEL);
1486         if (!net->ipv6.fib_table_hash)
1487                 goto out_rt6_stats;
1488
1489         net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1490                                           GFP_KERNEL);
1491         if (!net->ipv6.fib6_main_tbl)
1492                 goto out_fib_table_hash;
1493
1494         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1495         net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1496         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1497                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1498
1499 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1500         net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1501                                            GFP_KERNEL);
1502         if (!net->ipv6.fib6_local_tbl)
1503                 goto out_fib6_main_tbl;
1504         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1505         net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1506         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1507                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1508 #endif
1509         fib6_tables_init(net);
1510
1511         return 0;
1512
1513 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1514 out_fib6_main_tbl:
1515         kfree(net->ipv6.fib6_main_tbl);
1516 #endif
1517 out_fib_table_hash:
1518         kfree(net->ipv6.fib_table_hash);
1519 out_rt6_stats:
1520         kfree(net->ipv6.rt6_stats);
1521 out_timer:
1522         return -ENOMEM;
1523  }
1524
1525 static void fib6_net_exit(struct net *net)
1526 {
1527         rt6_ifdown(net, NULL);
1528         del_timer_sync(&net->ipv6.ip6_fib_timer);
1529
1530 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1531         kfree(net->ipv6.fib6_local_tbl);
1532 #endif
1533         kfree(net->ipv6.fib6_main_tbl);
1534         kfree(net->ipv6.fib_table_hash);
1535         kfree(net->ipv6.rt6_stats);
1536 }
1537
1538 static struct pernet_operations fib6_net_ops = {
1539         .init = fib6_net_init,
1540         .exit = fib6_net_exit,
1541 };
1542
1543 int __init fib6_init(void)
1544 {
1545         int ret = -ENOMEM;
1546
1547         fib6_node_kmem = kmem_cache_create("fib6_nodes",
1548                                            sizeof(struct fib6_node),
1549                                            0, SLAB_HWCACHE_ALIGN,
1550                                            NULL);
1551         if (!fib6_node_kmem)
1552                 goto out;
1553
1554         ret = register_pernet_subsys(&fib6_net_ops);
1555         if (ret)
1556                 goto out_kmem_cache_create;
1557
1558         ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib);
1559         if (ret)
1560                 goto out_unregister_subsys;
1561 out:
1562         return ret;
1563
1564 out_unregister_subsys:
1565         unregister_pernet_subsys(&fib6_net_ops);
1566 out_kmem_cache_create:
1567         kmem_cache_destroy(fib6_node_kmem);
1568         goto out;
1569 }
1570
1571 void fib6_gc_cleanup(void)
1572 {
1573         unregister_pernet_subsys(&fib6_net_ops);
1574         kmem_cache_destroy(fib6_node_kmem);
1575 }