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1/*
2 * Linux INET6 implementation
3 * Forwarding Information Database
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14/*
15 * Changes:
16 * Yuji SEKIYA @USAGI: Support default route on router node;
17 * remove ip6_null_entry from the top of
18 * routing table.
19 * Ville Nuorvala: Fixed routing subtrees.
20 */
21#include <linux/errno.h>
22#include <linux/types.h>
23#include <linux/net.h>
24#include <linux/route.h>
25#include <linux/netdevice.h>
26#include <linux/in6.h>
27#include <linux/init.h>
28#include <linux/list.h>
29#include <linux/slab.h>
30
31#ifdef CONFIG_PROC_FS
32#include <linux/proc_fs.h>
33#endif
34
35#include <net/ipv6.h>
36#include <net/ndisc.h>
37#include <net/addrconf.h>
38
39#include <net/ip6_fib.h>
40#include <net/ip6_route.h>
41
42#define RT6_DEBUG 2
43
44#if RT6_DEBUG >= 3
45#define RT6_TRACE(x...) printk(KERN_DEBUG x)
46#else
47#define RT6_TRACE(x...) do { ; } while (0)
48#endif
49
50static struct kmem_cache * fib6_node_kmem __read_mostly;
51
52enum fib_walk_state_t
53{
54#ifdef CONFIG_IPV6_SUBTREES
55 FWS_S,
56#endif
57 FWS_L,
58 FWS_R,
59 FWS_C,
60 FWS_U
61};
62
63struct fib6_cleaner_t
64{
65 struct fib6_walker_t w;
66 struct net *net;
67 int (*func)(struct rt6_info *, void *arg);
68 void *arg;
69};
70
71static DEFINE_RWLOCK(fib6_walker_lock);
72
73#ifdef CONFIG_IPV6_SUBTREES
74#define FWS_INIT FWS_S
75#else
76#define FWS_INIT FWS_L
77#endif
78
79static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
80 struct rt6_info *rt);
81static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
82static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
83static int fib6_walk(struct fib6_walker_t *w);
84static int fib6_walk_continue(struct fib6_walker_t *w);
85
86/*
87 * A routing update causes an increase of the serial number on the
88 * affected subtree. This allows for cached routes to be asynchronously
89 * tested when modifications are made to the destination cache as a
90 * result of redirects, path MTU changes, etc.
91 */
92
93static __u32 rt_sernum;
94
95static void fib6_gc_timer_cb(unsigned long arg);
96
97static LIST_HEAD(fib6_walkers);
98#define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
99
100static inline void fib6_walker_link(struct fib6_walker_t *w)
101{
102 write_lock_bh(&fib6_walker_lock);
103 list_add(&w->lh, &fib6_walkers);
104 write_unlock_bh(&fib6_walker_lock);
105}
106
107static inline void fib6_walker_unlink(struct fib6_walker_t *w)
108{
109 write_lock_bh(&fib6_walker_lock);
110 list_del(&w->lh);
111 write_unlock_bh(&fib6_walker_lock);
112}
113static __inline__ u32 fib6_new_sernum(void)
114{
115 u32 n = ++rt_sernum;
116 if ((__s32)n <= 0)
117 rt_sernum = n = 1;
118 return n;
119}
120
121/*
122 * Auxiliary address test functions for the radix tree.
123 *
124 * These assume a 32bit processor (although it will work on
125 * 64bit processors)
126 */
127
128/*
129 * test bit
130 */
131#if defined(__LITTLE_ENDIAN)
132# define BITOP_BE32_SWIZZLE (0x1F & ~7)
133#else
134# define BITOP_BE32_SWIZZLE 0
135#endif
136
137static __inline__ __be32 addr_bit_set(const void *token, int fn_bit)
138{
139 const __be32 *addr = token;
140 /*
141 * Here,
142 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
143 * is optimized version of
144 * htonl(1 << ((~fn_bit)&0x1F))
145 * See include/asm-generic/bitops/le.h.
146 */
147 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
148 addr[fn_bit >> 5];
149}
150
151static __inline__ struct fib6_node * node_alloc(void)
152{
153 struct fib6_node *fn;
154
155 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
156
157 return fn;
158}
159
160static __inline__ void node_free(struct fib6_node * fn)
161{
162 kmem_cache_free(fib6_node_kmem, fn);
163}
164
165static __inline__ void rt6_release(struct rt6_info *rt)
166{
167 if (atomic_dec_and_test(&rt->rt6i_ref))
168 dst_free(&rt->dst);
169}
170
171static void fib6_link_table(struct net *net, struct fib6_table *tb)
172{
173 unsigned int h;
174
175 /*
176 * Initialize table lock at a single place to give lockdep a key,
177 * tables aren't visible prior to being linked to the list.
178 */
179 rwlock_init(&tb->tb6_lock);
180
181 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
182
183 /*
184 * No protection necessary, this is the only list mutatation
185 * operation, tables never disappear once they exist.
186 */
187 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
188}
189
190#ifdef CONFIG_IPV6_MULTIPLE_TABLES
191
192static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
193{
194 struct fib6_table *table;
195
196 table = kzalloc(sizeof(*table), GFP_ATOMIC);
197 if (table != NULL) {
198 table->tb6_id = id;
199 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
200 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
201 }
202
203 return table;
204}
205
206struct fib6_table *fib6_new_table(struct net *net, u32 id)
207{
208 struct fib6_table *tb;
209
210 if (id == 0)
211 id = RT6_TABLE_MAIN;
212 tb = fib6_get_table(net, id);
213 if (tb)
214 return tb;
215
216 tb = fib6_alloc_table(net, id);
217 if (tb != NULL)
218 fib6_link_table(net, tb);
219
220 return tb;
221}
222
223struct fib6_table *fib6_get_table(struct net *net, u32 id)
224{
225 struct fib6_table *tb;
226 struct hlist_head *head;
227 struct hlist_node *node;
228 unsigned int h;
229
230 if (id == 0)
231 id = RT6_TABLE_MAIN;
232 h = id & (FIB6_TABLE_HASHSZ - 1);
233 rcu_read_lock();
234 head = &net->ipv6.fib_table_hash[h];
235 hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
236 if (tb->tb6_id == id) {
237 rcu_read_unlock();
238 return tb;
239 }
240 }
241 rcu_read_unlock();
242
243 return NULL;
244}
245
246static void __net_init fib6_tables_init(struct net *net)
247{
248 fib6_link_table(net, net->ipv6.fib6_main_tbl);
249 fib6_link_table(net, net->ipv6.fib6_local_tbl);
250}
251#else
252
253struct fib6_table *fib6_new_table(struct net *net, u32 id)
254{
255 return fib6_get_table(net, id);
256}
257
258struct fib6_table *fib6_get_table(struct net *net, u32 id)
259{
260 return net->ipv6.fib6_main_tbl;
261}
262
263struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
264 int flags, pol_lookup_t lookup)
265{
266 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
267}
268
269static void __net_init fib6_tables_init(struct net *net)
270{
271 fib6_link_table(net, net->ipv6.fib6_main_tbl);
272}
273
274#endif
275
276static int fib6_dump_node(struct fib6_walker_t *w)
277{
278 int res;
279 struct rt6_info *rt;
280
281 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
282 res = rt6_dump_route(rt, w->args);
283 if (res < 0) {
284 /* Frame is full, suspend walking */
285 w->leaf = rt;
286 return 1;
287 }
288 WARN_ON(res == 0);
289 }
290 w->leaf = NULL;
291 return 0;
292}
293
294static void fib6_dump_end(struct netlink_callback *cb)
295{
296 struct fib6_walker_t *w = (void*)cb->args[2];
297
298 if (w) {
299 if (cb->args[4]) {
300 cb->args[4] = 0;
301 fib6_walker_unlink(w);
302 }
303 cb->args[2] = 0;
304 kfree(w);
305 }
306 cb->done = (void*)cb->args[3];
307 cb->args[1] = 3;
308}
309
310static int fib6_dump_done(struct netlink_callback *cb)
311{
312 fib6_dump_end(cb);
313 return cb->done ? cb->done(cb) : 0;
314}
315
316static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
317 struct netlink_callback *cb)
318{
319 struct fib6_walker_t *w;
320 int res;
321
322 w = (void *)cb->args[2];
323 w->root = &table->tb6_root;
324
325 if (cb->args[4] == 0) {
326 w->count = 0;
327 w->skip = 0;
328
329 read_lock_bh(&table->tb6_lock);
330 res = fib6_walk(w);
331 read_unlock_bh(&table->tb6_lock);
332 if (res > 0) {
333 cb->args[4] = 1;
334 cb->args[5] = w->root->fn_sernum;
335 }
336 } else {
337 if (cb->args[5] != w->root->fn_sernum) {
338 /* Begin at the root if the tree changed */
339 cb->args[5] = w->root->fn_sernum;
340 w->state = FWS_INIT;
341 w->node = w->root;
342 w->skip = w->count;
343 } else
344 w->skip = 0;
345
346 read_lock_bh(&table->tb6_lock);
347 res = fib6_walk_continue(w);
348 read_unlock_bh(&table->tb6_lock);
349 if (res <= 0) {
350 fib6_walker_unlink(w);
351 cb->args[4] = 0;
352 }
353 }
354
355 return res;
356}
357
358static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
359{
360 struct net *net = sock_net(skb->sk);
361 unsigned int h, s_h;
362 unsigned int e = 0, s_e;
363 struct rt6_rtnl_dump_arg arg;
364 struct fib6_walker_t *w;
365 struct fib6_table *tb;
366 struct hlist_node *node;
367 struct hlist_head *head;
368 int res = 0;
369
370 s_h = cb->args[0];
371 s_e = cb->args[1];
372
373 w = (void *)cb->args[2];
374 if (w == NULL) {
375 /* New dump:
376 *
377 * 1. hook callback destructor.
378 */
379 cb->args[3] = (long)cb->done;
380 cb->done = fib6_dump_done;
381
382 /*
383 * 2. allocate and initialize walker.
384 */
385 w = kzalloc(sizeof(*w), GFP_ATOMIC);
386 if (w == NULL)
387 return -ENOMEM;
388 w->func = fib6_dump_node;
389 cb->args[2] = (long)w;
390 }
391
392 arg.skb = skb;
393 arg.cb = cb;
394 arg.net = net;
395 w->args = &arg;
396
397 rcu_read_lock();
398 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
399 e = 0;
400 head = &net->ipv6.fib_table_hash[h];
401 hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
402 if (e < s_e)
403 goto next;
404 res = fib6_dump_table(tb, skb, cb);
405 if (res != 0)
406 goto out;
407next:
408 e++;
409 }
410 }
411out:
412 rcu_read_unlock();
413 cb->args[1] = e;
414 cb->args[0] = h;
415
416 res = res < 0 ? res : skb->len;
417 if (res <= 0)
418 fib6_dump_end(cb);
419 return res;
420}
421
422/*
423 * Routing Table
424 *
425 * return the appropriate node for a routing tree "add" operation
426 * by either creating and inserting or by returning an existing
427 * node.
428 */
429
430static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
431 int addrlen, int plen,
432 int offset)
433{
434 struct fib6_node *fn, *in, *ln;
435 struct fib6_node *pn = NULL;
436 struct rt6key *key;
437 int bit;
438 __be32 dir = 0;
439 __u32 sernum = fib6_new_sernum();
440
441 RT6_TRACE("fib6_add_1\n");
442
443 /* insert node in tree */
444
445 fn = root;
446
447 do {
448 key = (struct rt6key *)((u8 *)fn->leaf + offset);
449
450 /*
451 * Prefix match
452 */
453 if (plen < fn->fn_bit ||
454 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
455 goto insert_above;
456
457 /*
458 * Exact match ?
459 */
460
461 if (plen == fn->fn_bit) {
462 /* clean up an intermediate node */
463 if ((fn->fn_flags & RTN_RTINFO) == 0) {
464 rt6_release(fn->leaf);
465 fn->leaf = NULL;
466 }
467
468 fn->fn_sernum = sernum;
469
470 return fn;
471 }
472
473 /*
474 * We have more bits to go
475 */
476
477 /* Try to walk down on tree. */
478 fn->fn_sernum = sernum;
479 dir = addr_bit_set(addr, fn->fn_bit);
480 pn = fn;
481 fn = dir ? fn->right: fn->left;
482 } while (fn);
483
484 /*
485 * We walked to the bottom of tree.
486 * Create new leaf node without children.
487 */
488
489 ln = node_alloc();
490
491 if (ln == NULL)
492 return NULL;
493 ln->fn_bit = plen;
494
495 ln->parent = pn;
496 ln->fn_sernum = sernum;
497
498 if (dir)
499 pn->right = ln;
500 else
501 pn->left = ln;
502
503 return ln;
504
505
506insert_above:
507 /*
508 * split since we don't have a common prefix anymore or
509 * we have a less significant route.
510 * we've to insert an intermediate node on the list
511 * this new node will point to the one we need to create
512 * and the current
513 */
514
515 pn = fn->parent;
516
517 /* find 1st bit in difference between the 2 addrs.
518
519 See comment in __ipv6_addr_diff: bit may be an invalid value,
520 but if it is >= plen, the value is ignored in any case.
521 */
522
523 bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
524
525 /*
526 * (intermediate)[in]
527 * / \
528 * (new leaf node)[ln] (old node)[fn]
529 */
530 if (plen > bit) {
531 in = node_alloc();
532 ln = node_alloc();
533
534 if (in == NULL || ln == NULL) {
535 if (in)
536 node_free(in);
537 if (ln)
538 node_free(ln);
539 return NULL;
540 }
541
542 /*
543 * new intermediate node.
544 * RTN_RTINFO will
545 * be off since that an address that chooses one of
546 * the branches would not match less specific routes
547 * in the other branch
548 */
549
550 in->fn_bit = bit;
551
552 in->parent = pn;
553 in->leaf = fn->leaf;
554 atomic_inc(&in->leaf->rt6i_ref);
555
556 in->fn_sernum = sernum;
557
558 /* update parent pointer */
559 if (dir)
560 pn->right = in;
561 else
562 pn->left = in;
563
564 ln->fn_bit = plen;
565
566 ln->parent = in;
567 fn->parent = in;
568
569 ln->fn_sernum = sernum;
570
571 if (addr_bit_set(addr, bit)) {
572 in->right = ln;
573 in->left = fn;
574 } else {
575 in->left = ln;
576 in->right = fn;
577 }
578 } else { /* plen <= bit */
579
580 /*
581 * (new leaf node)[ln]
582 * / \
583 * (old node)[fn] NULL
584 */
585
586 ln = node_alloc();
587
588 if (ln == NULL)
589 return NULL;
590
591 ln->fn_bit = plen;
592
593 ln->parent = pn;
594
595 ln->fn_sernum = sernum;
596
597 if (dir)
598 pn->right = ln;
599 else
600 pn->left = ln;
601
602 if (addr_bit_set(&key->addr, plen))
603 ln->right = fn;
604 else
605 ln->left = fn;
606
607 fn->parent = ln;
608 }
609 return ln;
610}
611
612/*
613 * Insert routing information in a node.
614 */
615
616static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
617 struct nl_info *info)
618{
619 struct rt6_info *iter = NULL;
620 struct rt6_info **ins;
621
622 ins = &fn->leaf;
623
624 for (iter = fn->leaf; iter; iter=iter->dst.rt6_next) {
625 /*
626 * Search for duplicates
627 */
628
629 if (iter->rt6i_metric == rt->rt6i_metric) {
630 /*
631 * Same priority level
632 */
633
634 if (iter->rt6i_dev == rt->rt6i_dev &&
635 iter->rt6i_idev == rt->rt6i_idev &&
636 ipv6_addr_equal(&iter->rt6i_gateway,
637 &rt->rt6i_gateway)) {
638 if (!(iter->rt6i_flags&RTF_EXPIRES))
639 return -EEXIST;
640 iter->rt6i_expires = rt->rt6i_expires;
641 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
642 iter->rt6i_flags &= ~RTF_EXPIRES;
643 iter->rt6i_expires = 0;
644 }
645 return -EEXIST;
646 }
647 }
648
649 if (iter->rt6i_metric > rt->rt6i_metric)
650 break;
651
652 ins = &iter->dst.rt6_next;
653 }
654
655 /* Reset round-robin state, if necessary */
656 if (ins == &fn->leaf)
657 fn->rr_ptr = NULL;
658
659 /*
660 * insert node
661 */
662
663 rt->dst.rt6_next = iter;
664 *ins = rt;
665 rt->rt6i_node = fn;
666 atomic_inc(&rt->rt6i_ref);
667 inet6_rt_notify(RTM_NEWROUTE, rt, info);
668 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
669
670 if ((fn->fn_flags & RTN_RTINFO) == 0) {
671 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
672 fn->fn_flags |= RTN_RTINFO;
673 }
674
675 return 0;
676}
677
678static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
679{
680 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
681 (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
682 mod_timer(&net->ipv6.ip6_fib_timer,
683 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
684}
685
686void fib6_force_start_gc(struct net *net)
687{
688 if (!timer_pending(&net->ipv6.ip6_fib_timer))
689 mod_timer(&net->ipv6.ip6_fib_timer,
690 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
691}
692
693/*
694 * Add routing information to the routing tree.
695 * <destination addr>/<source addr>
696 * with source addr info in sub-trees
697 */
698
699int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
700{
701 struct fib6_node *fn, *pn = NULL;
702 int err = -ENOMEM;
703
704 fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
705 rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
706
707 if (fn == NULL)
708 goto out;
709
710 pn = fn;
711
712#ifdef CONFIG_IPV6_SUBTREES
713 if (rt->rt6i_src.plen) {
714 struct fib6_node *sn;
715
716 if (fn->subtree == NULL) {
717 struct fib6_node *sfn;
718
719 /*
720 * Create subtree.
721 *
722 * fn[main tree]
723 * |
724 * sfn[subtree root]
725 * \
726 * sn[new leaf node]
727 */
728
729 /* Create subtree root node */
730 sfn = node_alloc();
731 if (sfn == NULL)
732 goto st_failure;
733
734 sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
735 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
736 sfn->fn_flags = RTN_ROOT;
737 sfn->fn_sernum = fib6_new_sernum();
738
739 /* Now add the first leaf node to new subtree */
740
741 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
742 sizeof(struct in6_addr), rt->rt6i_src.plen,
743 offsetof(struct rt6_info, rt6i_src));
744
745 if (sn == NULL) {
746 /* If it is failed, discard just allocated
747 root, and then (in st_failure) stale node
748 in main tree.
749 */
750 node_free(sfn);
751 goto st_failure;
752 }
753
754 /* Now link new subtree to main tree */
755 sfn->parent = fn;
756 fn->subtree = sfn;
757 } else {
758 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
759 sizeof(struct in6_addr), rt->rt6i_src.plen,
760 offsetof(struct rt6_info, rt6i_src));
761
762 if (sn == NULL)
763 goto st_failure;
764 }
765
766 if (fn->leaf == NULL) {
767 fn->leaf = rt;
768 atomic_inc(&rt->rt6i_ref);
769 }
770 fn = sn;
771 }
772#endif
773
774 err = fib6_add_rt2node(fn, rt, info);
775
776 if (err == 0) {
777 fib6_start_gc(info->nl_net, rt);
778 if (!(rt->rt6i_flags&RTF_CACHE))
779 fib6_prune_clones(info->nl_net, pn, rt);
780 }
781
782out:
783 if (err) {
784#ifdef CONFIG_IPV6_SUBTREES
785 /*
786 * If fib6_add_1 has cleared the old leaf pointer in the
787 * super-tree leaf node we have to find a new one for it.
788 */
789 if (pn != fn && pn->leaf == rt) {
790 pn->leaf = NULL;
791 atomic_dec(&rt->rt6i_ref);
792 }
793 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
794 pn->leaf = fib6_find_prefix(info->nl_net, pn);
795#if RT6_DEBUG >= 2
796 if (!pn->leaf) {
797 WARN_ON(pn->leaf == NULL);
798 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
799 }
800#endif
801 atomic_inc(&pn->leaf->rt6i_ref);
802 }
803#endif
804 dst_free(&rt->dst);
805 }
806 return err;
807
808#ifdef CONFIG_IPV6_SUBTREES
809 /* Subtree creation failed, probably main tree node
810 is orphan. If it is, shoot it.
811 */
812st_failure:
813 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
814 fib6_repair_tree(info->nl_net, fn);
815 dst_free(&rt->dst);
816 return err;
817#endif
818}
819
820/*
821 * Routing tree lookup
822 *
823 */
824
825struct lookup_args {
826 int offset; /* key offset on rt6_info */
827 const struct in6_addr *addr; /* search key */
828};
829
830static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
831 struct lookup_args *args)
832{
833 struct fib6_node *fn;
834 __be32 dir;
835
836 if (unlikely(args->offset == 0))
837 return NULL;
838
839 /*
840 * Descend on a tree
841 */
842
843 fn = root;
844
845 for (;;) {
846 struct fib6_node *next;
847
848 dir = addr_bit_set(args->addr, fn->fn_bit);
849
850 next = dir ? fn->right : fn->left;
851
852 if (next) {
853 fn = next;
854 continue;
855 }
856
857 break;
858 }
859
860 while(fn) {
861 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
862 struct rt6key *key;
863
864 key = (struct rt6key *) ((u8 *) fn->leaf +
865 args->offset);
866
867 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
868#ifdef CONFIG_IPV6_SUBTREES
869 if (fn->subtree)
870 fn = fib6_lookup_1(fn->subtree, args + 1);
871#endif
872 if (!fn || fn->fn_flags & RTN_RTINFO)
873 return fn;
874 }
875 }
876
877 if (fn->fn_flags & RTN_ROOT)
878 break;
879
880 fn = fn->parent;
881 }
882
883 return NULL;
884}
885
886struct fib6_node * fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
887 const struct in6_addr *saddr)
888{
889 struct fib6_node *fn;
890 struct lookup_args args[] = {
891 {
892 .offset = offsetof(struct rt6_info, rt6i_dst),
893 .addr = daddr,
894 },
895#ifdef CONFIG_IPV6_SUBTREES
896 {
897 .offset = offsetof(struct rt6_info, rt6i_src),
898 .addr = saddr,
899 },
900#endif
901 {
902 .offset = 0, /* sentinel */
903 }
904 };
905
906 fn = fib6_lookup_1(root, daddr ? args : args + 1);
907
908 if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
909 fn = root;
910
911 return fn;
912}
913
914/*
915 * Get node with specified destination prefix (and source prefix,
916 * if subtrees are used)
917 */
918
919
920static struct fib6_node * fib6_locate_1(struct fib6_node *root,
921 const struct in6_addr *addr,
922 int plen, int offset)
923{
924 struct fib6_node *fn;
925
926 for (fn = root; fn ; ) {
927 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
928
929 /*
930 * Prefix match
931 */
932 if (plen < fn->fn_bit ||
933 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
934 return NULL;
935
936 if (plen == fn->fn_bit)
937 return fn;
938
939 /*
940 * We have more bits to go
941 */
942 if (addr_bit_set(addr, fn->fn_bit))
943 fn = fn->right;
944 else
945 fn = fn->left;
946 }
947 return NULL;
948}
949
950struct fib6_node * fib6_locate(struct fib6_node *root,
951 const struct in6_addr *daddr, int dst_len,
952 const struct in6_addr *saddr, int src_len)
953{
954 struct fib6_node *fn;
955
956 fn = fib6_locate_1(root, daddr, dst_len,
957 offsetof(struct rt6_info, rt6i_dst));
958
959#ifdef CONFIG_IPV6_SUBTREES
960 if (src_len) {
961 WARN_ON(saddr == NULL);
962 if (fn && fn->subtree)
963 fn = fib6_locate_1(fn->subtree, saddr, src_len,
964 offsetof(struct rt6_info, rt6i_src));
965 }
966#endif
967
968 if (fn && fn->fn_flags&RTN_RTINFO)
969 return fn;
970
971 return NULL;
972}
973
974
975/*
976 * Deletion
977 *
978 */
979
980static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
981{
982 if (fn->fn_flags&RTN_ROOT)
983 return net->ipv6.ip6_null_entry;
984
985 while(fn) {
986 if(fn->left)
987 return fn->left->leaf;
988
989 if(fn->right)
990 return fn->right->leaf;
991
992 fn = FIB6_SUBTREE(fn);
993 }
994 return NULL;
995}
996
997/*
998 * Called to trim the tree of intermediate nodes when possible. "fn"
999 * is the node we want to try and remove.
1000 */
1001
1002static struct fib6_node *fib6_repair_tree(struct net *net,
1003 struct fib6_node *fn)
1004{
1005 int children;
1006 int nstate;
1007 struct fib6_node *child, *pn;
1008 struct fib6_walker_t *w;
1009 int iter = 0;
1010
1011 for (;;) {
1012 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1013 iter++;
1014
1015 WARN_ON(fn->fn_flags & RTN_RTINFO);
1016 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1017 WARN_ON(fn->leaf != NULL);
1018
1019 children = 0;
1020 child = NULL;
1021 if (fn->right) child = fn->right, children |= 1;
1022 if (fn->left) child = fn->left, children |= 2;
1023
1024 if (children == 3 || FIB6_SUBTREE(fn)
1025#ifdef CONFIG_IPV6_SUBTREES
1026 /* Subtree root (i.e. fn) may have one child */
1027 || (children && fn->fn_flags&RTN_ROOT)
1028#endif
1029 ) {
1030 fn->leaf = fib6_find_prefix(net, fn);
1031#if RT6_DEBUG >= 2
1032 if (fn->leaf==NULL) {
1033 WARN_ON(!fn->leaf);
1034 fn->leaf = net->ipv6.ip6_null_entry;
1035 }
1036#endif
1037 atomic_inc(&fn->leaf->rt6i_ref);
1038 return fn->parent;
1039 }
1040
1041 pn = fn->parent;
1042#ifdef CONFIG_IPV6_SUBTREES
1043 if (FIB6_SUBTREE(pn) == fn) {
1044 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1045 FIB6_SUBTREE(pn) = NULL;
1046 nstate = FWS_L;
1047 } else {
1048 WARN_ON(fn->fn_flags & RTN_ROOT);
1049#endif
1050 if (pn->right == fn) pn->right = child;
1051 else if (pn->left == fn) pn->left = child;
1052#if RT6_DEBUG >= 2
1053 else
1054 WARN_ON(1);
1055#endif
1056 if (child)
1057 child->parent = pn;
1058 nstate = FWS_R;
1059#ifdef CONFIG_IPV6_SUBTREES
1060 }
1061#endif
1062
1063 read_lock(&fib6_walker_lock);
1064 FOR_WALKERS(w) {
1065 if (child == NULL) {
1066 if (w->root == fn) {
1067 w->root = w->node = NULL;
1068 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1069 } else if (w->node == fn) {
1070 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1071 w->node = pn;
1072 w->state = nstate;
1073 }
1074 } else {
1075 if (w->root == fn) {
1076 w->root = child;
1077 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1078 }
1079 if (w->node == fn) {
1080 w->node = child;
1081 if (children&2) {
1082 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1083 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1084 } else {
1085 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1086 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1087 }
1088 }
1089 }
1090 }
1091 read_unlock(&fib6_walker_lock);
1092
1093 node_free(fn);
1094 if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn))
1095 return pn;
1096
1097 rt6_release(pn->leaf);
1098 pn->leaf = NULL;
1099 fn = pn;
1100 }
1101}
1102
1103static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1104 struct nl_info *info)
1105{
1106 struct fib6_walker_t *w;
1107 struct rt6_info *rt = *rtp;
1108 struct net *net = info->nl_net;
1109
1110 RT6_TRACE("fib6_del_route\n");
1111
1112 /* Unlink it */
1113 *rtp = rt->dst.rt6_next;
1114 rt->rt6i_node = NULL;
1115 net->ipv6.rt6_stats->fib_rt_entries--;
1116 net->ipv6.rt6_stats->fib_discarded_routes++;
1117
1118 /* Reset round-robin state, if necessary */
1119 if (fn->rr_ptr == rt)
1120 fn->rr_ptr = NULL;
1121
1122 /* Adjust walkers */
1123 read_lock(&fib6_walker_lock);
1124 FOR_WALKERS(w) {
1125 if (w->state == FWS_C && w->leaf == rt) {
1126 RT6_TRACE("walker %p adjusted by delroute\n", w);
1127 w->leaf = rt->dst.rt6_next;
1128 if (w->leaf == NULL)
1129 w->state = FWS_U;
1130 }
1131 }
1132 read_unlock(&fib6_walker_lock);
1133
1134 rt->dst.rt6_next = NULL;
1135
1136 /* If it was last route, expunge its radix tree node */
1137 if (fn->leaf == NULL) {
1138 fn->fn_flags &= ~RTN_RTINFO;
1139 net->ipv6.rt6_stats->fib_route_nodes--;
1140 fn = fib6_repair_tree(net, fn);
1141 }
1142
1143 if (atomic_read(&rt->rt6i_ref) != 1) {
1144 /* This route is used as dummy address holder in some split
1145 * nodes. It is not leaked, but it still holds other resources,
1146 * which must be released in time. So, scan ascendant nodes
1147 * and replace dummy references to this route with references
1148 * to still alive ones.
1149 */
1150 while (fn) {
1151 if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
1152 fn->leaf = fib6_find_prefix(net, fn);
1153 atomic_inc(&fn->leaf->rt6i_ref);
1154 rt6_release(rt);
1155 }
1156 fn = fn->parent;
1157 }
1158 /* No more references are possible at this point. */
1159 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1160 }
1161
1162 inet6_rt_notify(RTM_DELROUTE, rt, info);
1163 rt6_release(rt);
1164}
1165
1166int fib6_del(struct rt6_info *rt, struct nl_info *info)
1167{
1168 struct net *net = info->nl_net;
1169 struct fib6_node *fn = rt->rt6i_node;
1170 struct rt6_info **rtp;
1171
1172#if RT6_DEBUG >= 2
1173 if (rt->dst.obsolete>0) {
1174 WARN_ON(fn != NULL);
1175 return -ENOENT;
1176 }
1177#endif
1178 if (fn == NULL || rt == net->ipv6.ip6_null_entry)
1179 return -ENOENT;
1180
1181 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1182
1183 if (!(rt->rt6i_flags&RTF_CACHE)) {
1184 struct fib6_node *pn = fn;
1185#ifdef CONFIG_IPV6_SUBTREES
1186 /* clones of this route might be in another subtree */
1187 if (rt->rt6i_src.plen) {
1188 while (!(pn->fn_flags&RTN_ROOT))
1189 pn = pn->parent;
1190 pn = pn->parent;
1191 }
1192#endif
1193 fib6_prune_clones(info->nl_net, pn, rt);
1194 }
1195
1196 /*
1197 * Walk the leaf entries looking for ourself
1198 */
1199
1200 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1201 if (*rtp == rt) {
1202 fib6_del_route(fn, rtp, info);
1203 return 0;
1204 }
1205 }
1206 return -ENOENT;
1207}
1208
1209/*
1210 * Tree traversal function.
1211 *
1212 * Certainly, it is not interrupt safe.
1213 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1214 * It means, that we can modify tree during walking
1215 * and use this function for garbage collection, clone pruning,
1216 * cleaning tree when a device goes down etc. etc.
1217 *
1218 * It guarantees that every node will be traversed,
1219 * and that it will be traversed only once.
1220 *
1221 * Callback function w->func may return:
1222 * 0 -> continue walking.
1223 * positive value -> walking is suspended (used by tree dumps,
1224 * and probably by gc, if it will be split to several slices)
1225 * negative value -> terminate walking.
1226 *
1227 * The function itself returns:
1228 * 0 -> walk is complete.
1229 * >0 -> walk is incomplete (i.e. suspended)
1230 * <0 -> walk is terminated by an error.
1231 */
1232
1233static int fib6_walk_continue(struct fib6_walker_t *w)
1234{
1235 struct fib6_node *fn, *pn;
1236
1237 for (;;) {
1238 fn = w->node;
1239 if (fn == NULL)
1240 return 0;
1241
1242 if (w->prune && fn != w->root &&
1243 fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1244 w->state = FWS_C;
1245 w->leaf = fn->leaf;
1246 }
1247 switch (w->state) {
1248#ifdef CONFIG_IPV6_SUBTREES
1249 case FWS_S:
1250 if (FIB6_SUBTREE(fn)) {
1251 w->node = FIB6_SUBTREE(fn);
1252 continue;
1253 }
1254 w->state = FWS_L;
1255#endif
1256 case FWS_L:
1257 if (fn->left) {
1258 w->node = fn->left;
1259 w->state = FWS_INIT;
1260 continue;
1261 }
1262 w->state = FWS_R;
1263 case FWS_R:
1264 if (fn->right) {
1265 w->node = fn->right;
1266 w->state = FWS_INIT;
1267 continue;
1268 }
1269 w->state = FWS_C;
1270 w->leaf = fn->leaf;
1271 case FWS_C:
1272 if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1273 int err;
1274
1275 if (w->count < w->skip) {
1276 w->count++;
1277 continue;
1278 }
1279
1280 err = w->func(w);
1281 if (err)
1282 return err;
1283
1284 w->count++;
1285 continue;
1286 }
1287 w->state = FWS_U;
1288 case FWS_U:
1289 if (fn == w->root)
1290 return 0;
1291 pn = fn->parent;
1292 w->node = pn;
1293#ifdef CONFIG_IPV6_SUBTREES
1294 if (FIB6_SUBTREE(pn) == fn) {
1295 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1296 w->state = FWS_L;
1297 continue;
1298 }
1299#endif
1300 if (pn->left == fn) {
1301 w->state = FWS_R;
1302 continue;
1303 }
1304 if (pn->right == fn) {
1305 w->state = FWS_C;
1306 w->leaf = w->node->leaf;
1307 continue;
1308 }
1309#if RT6_DEBUG >= 2
1310 WARN_ON(1);
1311#endif
1312 }
1313 }
1314}
1315
1316static int fib6_walk(struct fib6_walker_t *w)
1317{
1318 int res;
1319
1320 w->state = FWS_INIT;
1321 w->node = w->root;
1322
1323 fib6_walker_link(w);
1324 res = fib6_walk_continue(w);
1325 if (res <= 0)
1326 fib6_walker_unlink(w);
1327 return res;
1328}
1329
1330static int fib6_clean_node(struct fib6_walker_t *w)
1331{
1332 int res;
1333 struct rt6_info *rt;
1334 struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1335 struct nl_info info = {
1336 .nl_net = c->net,
1337 };
1338
1339 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1340 res = c->func(rt, c->arg);
1341 if (res < 0) {
1342 w->leaf = rt;
1343 res = fib6_del(rt, &info);
1344 if (res) {
1345#if RT6_DEBUG >= 2
1346 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1347#endif
1348 continue;
1349 }
1350 return 0;
1351 }
1352 WARN_ON(res != 0);
1353 }
1354 w->leaf = rt;
1355 return 0;
1356}
1357
1358/*
1359 * Convenient frontend to tree walker.
1360 *
1361 * func is called on each route.
1362 * It may return -1 -> delete this route.
1363 * 0 -> continue walking
1364 *
1365 * prune==1 -> only immediate children of node (certainly,
1366 * ignoring pure split nodes) will be scanned.
1367 */
1368
1369static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1370 int (*func)(struct rt6_info *, void *arg),
1371 int prune, void *arg)
1372{
1373 struct fib6_cleaner_t c;
1374
1375 c.w.root = root;
1376 c.w.func = fib6_clean_node;
1377 c.w.prune = prune;
1378 c.w.count = 0;
1379 c.w.skip = 0;
1380 c.func = func;
1381 c.arg = arg;
1382 c.net = net;
1383
1384 fib6_walk(&c.w);
1385}
1386
1387void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1388 int prune, void *arg)
1389{
1390 struct fib6_table *table;
1391 struct hlist_node *node;
1392 struct hlist_head *head;
1393 unsigned int h;
1394
1395 rcu_read_lock();
1396 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1397 head = &net->ipv6.fib_table_hash[h];
1398 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1399 write_lock_bh(&table->tb6_lock);
1400 fib6_clean_tree(net, &table->tb6_root,
1401 func, prune, arg);
1402 write_unlock_bh(&table->tb6_lock);
1403 }
1404 }
1405 rcu_read_unlock();
1406}
1407
1408static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1409{
1410 if (rt->rt6i_flags & RTF_CACHE) {
1411 RT6_TRACE("pruning clone %p\n", rt);
1412 return -1;
1413 }
1414
1415 return 0;
1416}
1417
1418static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1419 struct rt6_info *rt)
1420{
1421 fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1422}
1423
1424/*
1425 * Garbage collection
1426 */
1427
1428static struct fib6_gc_args
1429{
1430 int timeout;
1431 int more;
1432} gc_args;
1433
1434static int fib6_age(struct rt6_info *rt, void *arg)
1435{
1436 unsigned long now = jiffies;
1437
1438 /*
1439 * check addrconf expiration here.
1440 * Routes are expired even if they are in use.
1441 *
1442 * Also age clones. Note, that clones are aged out
1443 * only if they are not in use now.
1444 */
1445
1446 if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1447 if (time_after(now, rt->rt6i_expires)) {
1448 RT6_TRACE("expiring %p\n", rt);
1449 return -1;
1450 }
1451 gc_args.more++;
1452 } else if (rt->rt6i_flags & RTF_CACHE) {
1453 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1454 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1455 RT6_TRACE("aging clone %p\n", rt);
1456 return -1;
1457 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1458 (!(dst_get_neighbour_raw(&rt->dst)->flags & NTF_ROUTER))) {
1459 RT6_TRACE("purging route %p via non-router but gateway\n",
1460 rt);
1461 return -1;
1462 }
1463 gc_args.more++;
1464 }
1465
1466 return 0;
1467}
1468
1469static DEFINE_SPINLOCK(fib6_gc_lock);
1470
1471void fib6_run_gc(unsigned long expires, struct net *net)
1472{
1473 if (expires != ~0UL) {
1474 spin_lock_bh(&fib6_gc_lock);
1475 gc_args.timeout = expires ? (int)expires :
1476 net->ipv6.sysctl.ip6_rt_gc_interval;
1477 } else {
1478 if (!spin_trylock_bh(&fib6_gc_lock)) {
1479 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1480 return;
1481 }
1482 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1483 }
1484
1485 gc_args.more = icmp6_dst_gc();
1486
1487 fib6_clean_all(net, fib6_age, 0, NULL);
1488
1489 if (gc_args.more)
1490 mod_timer(&net->ipv6.ip6_fib_timer,
1491 round_jiffies(jiffies
1492 + net->ipv6.sysctl.ip6_rt_gc_interval));
1493 else
1494 del_timer(&net->ipv6.ip6_fib_timer);
1495 spin_unlock_bh(&fib6_gc_lock);
1496}
1497
1498static void fib6_gc_timer_cb(unsigned long arg)
1499{
1500 fib6_run_gc(0, (struct net *)arg);
1501}
1502
1503static int __net_init fib6_net_init(struct net *net)
1504{
1505 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1506
1507 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1508
1509 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1510 if (!net->ipv6.rt6_stats)
1511 goto out_timer;
1512
1513 /* Avoid false sharing : Use at least a full cache line */
1514 size = max_t(size_t, size, L1_CACHE_BYTES);
1515
1516 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1517 if (!net->ipv6.fib_table_hash)
1518 goto out_rt6_stats;
1519
1520 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1521 GFP_KERNEL);
1522 if (!net->ipv6.fib6_main_tbl)
1523 goto out_fib_table_hash;
1524
1525 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1526 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1527 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1528 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1529
1530#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1531 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1532 GFP_KERNEL);
1533 if (!net->ipv6.fib6_local_tbl)
1534 goto out_fib6_main_tbl;
1535 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1536 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1537 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1538 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1539#endif
1540 fib6_tables_init(net);
1541
1542 return 0;
1543
1544#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1545out_fib6_main_tbl:
1546 kfree(net->ipv6.fib6_main_tbl);
1547#endif
1548out_fib_table_hash:
1549 kfree(net->ipv6.fib_table_hash);
1550out_rt6_stats:
1551 kfree(net->ipv6.rt6_stats);
1552out_timer:
1553 return -ENOMEM;
1554 }
1555
1556static void fib6_net_exit(struct net *net)
1557{
1558 rt6_ifdown(net, NULL);
1559 del_timer_sync(&net->ipv6.ip6_fib_timer);
1560
1561#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1562 kfree(net->ipv6.fib6_local_tbl);
1563#endif
1564 kfree(net->ipv6.fib6_main_tbl);
1565 kfree(net->ipv6.fib_table_hash);
1566 kfree(net->ipv6.rt6_stats);
1567}
1568
1569static struct pernet_operations fib6_net_ops = {
1570 .init = fib6_net_init,
1571 .exit = fib6_net_exit,
1572};
1573
1574int __init fib6_init(void)
1575{
1576 int ret = -ENOMEM;
1577
1578 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1579 sizeof(struct fib6_node),
1580 0, SLAB_HWCACHE_ALIGN,
1581 NULL);
1582 if (!fib6_node_kmem)
1583 goto out;
1584
1585 ret = register_pernet_subsys(&fib6_net_ops);
1586 if (ret)
1587 goto out_kmem_cache_create;
1588
1589 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1590 NULL);
1591 if (ret)
1592 goto out_unregister_subsys;
1593out:
1594 return ret;
1595
1596out_unregister_subsys:
1597 unregister_pernet_subsys(&fib6_net_ops);
1598out_kmem_cache_create:
1599 kmem_cache_destroy(fib6_node_kmem);
1600 goto out;
1601}
1602
1603void fib6_gc_cleanup(void)
1604{
1605 unregister_pernet_subsys(&fib6_net_ops);
1606 kmem_cache_destroy(fib6_node_kmem);
1607}
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
22#define pr_fmt(fmt) "IPv6: " fmt
23
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/net.h>
27#include <linux/route.h>
28#include <linux/netdevice.h>
29#include <linux/in6.h>
30#include <linux/init.h>
31#include <linux/list.h>
32#include <linux/slab.h>
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...) pr_debug(x)
45#else
46#define RT6_TRACE(x...) do { ; } while (0)
47#endif
48
49static struct kmem_cache * fib6_node_kmem __read_mostly;
50
51enum 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
62struct 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
70static 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
78static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
79 struct rt6_info *rt);
80static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
81static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
82static int fib6_walk(struct fib6_walker_t *w);
83static 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
92static __u32 rt_sernum;
93
94static void fib6_gc_timer_cb(unsigned long arg);
95
96static LIST_HEAD(fib6_walkers);
97#define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
98
99static inline void fib6_walker_link(struct fib6_walker_t *w)
100{
101 write_lock_bh(&fib6_walker_lock);
102 list_add(&w->lh, &fib6_walkers);
103 write_unlock_bh(&fib6_walker_lock);
104}
105
106static inline void fib6_walker_unlink(struct fib6_walker_t *w)
107{
108 write_lock_bh(&fib6_walker_lock);
109 list_del(&w->lh);
110 write_unlock_bh(&fib6_walker_lock);
111}
112static __inline__ u32 fib6_new_sernum(void)
113{
114 u32 n = ++rt_sernum;
115 if ((__s32)n <= 0)
116 rt_sernum = n = 1;
117 return n;
118}
119
120/*
121 * Auxiliary address test functions for the radix tree.
122 *
123 * These assume a 32bit processor (although it will work on
124 * 64bit processors)
125 */
126
127/*
128 * test bit
129 */
130#if defined(__LITTLE_ENDIAN)
131# define BITOP_BE32_SWIZZLE (0x1F & ~7)
132#else
133# define BITOP_BE32_SWIZZLE 0
134#endif
135
136static __inline__ __be32 addr_bit_set(const void *token, int fn_bit)
137{
138 const __be32 *addr = token;
139 /*
140 * Here,
141 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
142 * is optimized version of
143 * htonl(1 << ((~fn_bit)&0x1F))
144 * See include/asm-generic/bitops/le.h.
145 */
146 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
147 addr[fn_bit >> 5];
148}
149
150static __inline__ struct fib6_node * node_alloc(void)
151{
152 struct fib6_node *fn;
153
154 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
155
156 return fn;
157}
158
159static __inline__ void node_free(struct fib6_node * fn)
160{
161 kmem_cache_free(fib6_node_kmem, fn);
162}
163
164static __inline__ void rt6_release(struct rt6_info *rt)
165{
166 if (atomic_dec_and_test(&rt->rt6i_ref))
167 dst_free(&rt->dst);
168}
169
170static void fib6_link_table(struct net *net, struct fib6_table *tb)
171{
172 unsigned int h;
173
174 /*
175 * Initialize table lock at a single place to give lockdep a key,
176 * tables aren't visible prior to being linked to the list.
177 */
178 rwlock_init(&tb->tb6_lock);
179
180 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
181
182 /*
183 * No protection necessary, this is the only list mutatation
184 * operation, tables never disappear once they exist.
185 */
186 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
187}
188
189#ifdef CONFIG_IPV6_MULTIPLE_TABLES
190
191static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
192{
193 struct fib6_table *table;
194
195 table = kzalloc(sizeof(*table), GFP_ATOMIC);
196 if (table) {
197 table->tb6_id = id;
198 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
199 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
200 }
201
202 return table;
203}
204
205struct fib6_table *fib6_new_table(struct net *net, u32 id)
206{
207 struct fib6_table *tb;
208
209 if (id == 0)
210 id = RT6_TABLE_MAIN;
211 tb = fib6_get_table(net, id);
212 if (tb)
213 return tb;
214
215 tb = fib6_alloc_table(net, id);
216 if (tb)
217 fib6_link_table(net, tb);
218
219 return tb;
220}
221
222struct fib6_table *fib6_get_table(struct net *net, u32 id)
223{
224 struct fib6_table *tb;
225 struct hlist_head *head;
226 struct hlist_node *node;
227 unsigned int h;
228
229 if (id == 0)
230 id = RT6_TABLE_MAIN;
231 h = id & (FIB6_TABLE_HASHSZ - 1);
232 rcu_read_lock();
233 head = &net->ipv6.fib_table_hash[h];
234 hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
235 if (tb->tb6_id == id) {
236 rcu_read_unlock();
237 return tb;
238 }
239 }
240 rcu_read_unlock();
241
242 return NULL;
243}
244
245static void __net_init fib6_tables_init(struct net *net)
246{
247 fib6_link_table(net, net->ipv6.fib6_main_tbl);
248 fib6_link_table(net, net->ipv6.fib6_local_tbl);
249}
250#else
251
252struct fib6_table *fib6_new_table(struct net *net, u32 id)
253{
254 return fib6_get_table(net, id);
255}
256
257struct fib6_table *fib6_get_table(struct net *net, u32 id)
258{
259 return net->ipv6.fib6_main_tbl;
260}
261
262struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
263 int flags, pol_lookup_t lookup)
264{
265 return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
266}
267
268static void __net_init fib6_tables_init(struct net *net)
269{
270 fib6_link_table(net, net->ipv6.fib6_main_tbl);
271}
272
273#endif
274
275static int fib6_dump_node(struct fib6_walker_t *w)
276{
277 int res;
278 struct rt6_info *rt;
279
280 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
281 res = rt6_dump_route(rt, w->args);
282 if (res < 0) {
283 /* Frame is full, suspend walking */
284 w->leaf = rt;
285 return 1;
286 }
287 WARN_ON(res == 0);
288 }
289 w->leaf = NULL;
290 return 0;
291}
292
293static void fib6_dump_end(struct netlink_callback *cb)
294{
295 struct fib6_walker_t *w = (void*)cb->args[2];
296
297 if (w) {
298 if (cb->args[4]) {
299 cb->args[4] = 0;
300 fib6_walker_unlink(w);
301 }
302 cb->args[2] = 0;
303 kfree(w);
304 }
305 cb->done = (void*)cb->args[3];
306 cb->args[1] = 3;
307}
308
309static int fib6_dump_done(struct netlink_callback *cb)
310{
311 fib6_dump_end(cb);
312 return cb->done ? cb->done(cb) : 0;
313}
314
315static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
316 struct netlink_callback *cb)
317{
318 struct fib6_walker_t *w;
319 int res;
320
321 w = (void *)cb->args[2];
322 w->root = &table->tb6_root;
323
324 if (cb->args[4] == 0) {
325 w->count = 0;
326 w->skip = 0;
327
328 read_lock_bh(&table->tb6_lock);
329 res = fib6_walk(w);
330 read_unlock_bh(&table->tb6_lock);
331 if (res > 0) {
332 cb->args[4] = 1;
333 cb->args[5] = w->root->fn_sernum;
334 }
335 } else {
336 if (cb->args[5] != w->root->fn_sernum) {
337 /* Begin at the root if the tree changed */
338 cb->args[5] = w->root->fn_sernum;
339 w->state = FWS_INIT;
340 w->node = w->root;
341 w->skip = w->count;
342 } else
343 w->skip = 0;
344
345 read_lock_bh(&table->tb6_lock);
346 res = fib6_walk_continue(w);
347 read_unlock_bh(&table->tb6_lock);
348 if (res <= 0) {
349 fib6_walker_unlink(w);
350 cb->args[4] = 0;
351 }
352 }
353
354 return res;
355}
356
357static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
358{
359 struct net *net = sock_net(skb->sk);
360 unsigned int h, s_h;
361 unsigned int e = 0, s_e;
362 struct rt6_rtnl_dump_arg arg;
363 struct fib6_walker_t *w;
364 struct fib6_table *tb;
365 struct hlist_node *node;
366 struct hlist_head *head;
367 int res = 0;
368
369 s_h = cb->args[0];
370 s_e = cb->args[1];
371
372 w = (void *)cb->args[2];
373 if (!w) {
374 /* New dump:
375 *
376 * 1. hook callback destructor.
377 */
378 cb->args[3] = (long)cb->done;
379 cb->done = fib6_dump_done;
380
381 /*
382 * 2. allocate and initialize walker.
383 */
384 w = kzalloc(sizeof(*w), GFP_ATOMIC);
385 if (!w)
386 return -ENOMEM;
387 w->func = fib6_dump_node;
388 cb->args[2] = (long)w;
389 }
390
391 arg.skb = skb;
392 arg.cb = cb;
393 arg.net = net;
394 w->args = &arg;
395
396 rcu_read_lock();
397 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
398 e = 0;
399 head = &net->ipv6.fib_table_hash[h];
400 hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
401 if (e < s_e)
402 goto next;
403 res = fib6_dump_table(tb, skb, cb);
404 if (res != 0)
405 goto out;
406next:
407 e++;
408 }
409 }
410out:
411 rcu_read_unlock();
412 cb->args[1] = e;
413 cb->args[0] = h;
414
415 res = res < 0 ? res : skb->len;
416 if (res <= 0)
417 fib6_dump_end(cb);
418 return res;
419}
420
421/*
422 * Routing Table
423 *
424 * return the appropriate node for a routing tree "add" operation
425 * by either creating and inserting or by returning an existing
426 * node.
427 */
428
429static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
430 int addrlen, int plen,
431 int offset, int allow_create,
432 int replace_required)
433{
434 struct fib6_node *fn, *in, *ln;
435 struct fib6_node *pn = NULL;
436 struct rt6key *key;
437 int bit;
438 __be32 dir = 0;
439 __u32 sernum = fib6_new_sernum();
440
441 RT6_TRACE("fib6_add_1\n");
442
443 /* insert node in tree */
444
445 fn = root;
446
447 do {
448 key = (struct rt6key *)((u8 *)fn->leaf + offset);
449
450 /*
451 * Prefix match
452 */
453 if (plen < fn->fn_bit ||
454 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
455 if (!allow_create) {
456 if (replace_required) {
457 pr_warn("Can't replace route, no match found\n");
458 return ERR_PTR(-ENOENT);
459 }
460 pr_warn("NLM_F_CREATE should be set when creating new route\n");
461 }
462 goto insert_above;
463 }
464
465 /*
466 * Exact match ?
467 */
468
469 if (plen == fn->fn_bit) {
470 /* clean up an intermediate node */
471 if (!(fn->fn_flags & RTN_RTINFO)) {
472 rt6_release(fn->leaf);
473 fn->leaf = NULL;
474 }
475
476 fn->fn_sernum = sernum;
477
478 return fn;
479 }
480
481 /*
482 * We have more bits to go
483 */
484
485 /* Try to walk down on tree. */
486 fn->fn_sernum = sernum;
487 dir = addr_bit_set(addr, fn->fn_bit);
488 pn = fn;
489 fn = dir ? fn->right: fn->left;
490 } while (fn);
491
492 if (!allow_create) {
493 /* We should not create new node because
494 * NLM_F_REPLACE was specified without NLM_F_CREATE
495 * I assume it is safe to require NLM_F_CREATE when
496 * REPLACE flag is used! Later we may want to remove the
497 * check for replace_required, because according
498 * to netlink specification, NLM_F_CREATE
499 * MUST be specified if new route is created.
500 * That would keep IPv6 consistent with IPv4
501 */
502 if (replace_required) {
503 pr_warn("Can't replace route, no match found\n");
504 return ERR_PTR(-ENOENT);
505 }
506 pr_warn("NLM_F_CREATE should be set when creating new route\n");
507 }
508 /*
509 * We walked to the bottom of tree.
510 * Create new leaf node without children.
511 */
512
513 ln = node_alloc();
514
515 if (!ln)
516 return NULL;
517 ln->fn_bit = plen;
518
519 ln->parent = pn;
520 ln->fn_sernum = sernum;
521
522 if (dir)
523 pn->right = ln;
524 else
525 pn->left = ln;
526
527 return ln;
528
529
530insert_above:
531 /*
532 * split since we don't have a common prefix anymore or
533 * we have a less significant route.
534 * we've to insert an intermediate node on the list
535 * this new node will point to the one we need to create
536 * and the current
537 */
538
539 pn = fn->parent;
540
541 /* find 1st bit in difference between the 2 addrs.
542
543 See comment in __ipv6_addr_diff: bit may be an invalid value,
544 but if it is >= plen, the value is ignored in any case.
545 */
546
547 bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
548
549 /*
550 * (intermediate)[in]
551 * / \
552 * (new leaf node)[ln] (old node)[fn]
553 */
554 if (plen > bit) {
555 in = node_alloc();
556 ln = node_alloc();
557
558 if (!in || !ln) {
559 if (in)
560 node_free(in);
561 if (ln)
562 node_free(ln);
563 return NULL;
564 }
565
566 /*
567 * new intermediate node.
568 * RTN_RTINFO will
569 * be off since that an address that chooses one of
570 * the branches would not match less specific routes
571 * in the other branch
572 */
573
574 in->fn_bit = bit;
575
576 in->parent = pn;
577 in->leaf = fn->leaf;
578 atomic_inc(&in->leaf->rt6i_ref);
579
580 in->fn_sernum = sernum;
581
582 /* update parent pointer */
583 if (dir)
584 pn->right = in;
585 else
586 pn->left = in;
587
588 ln->fn_bit = plen;
589
590 ln->parent = in;
591 fn->parent = in;
592
593 ln->fn_sernum = sernum;
594
595 if (addr_bit_set(addr, bit)) {
596 in->right = ln;
597 in->left = fn;
598 } else {
599 in->left = ln;
600 in->right = fn;
601 }
602 } else { /* plen <= bit */
603
604 /*
605 * (new leaf node)[ln]
606 * / \
607 * (old node)[fn] NULL
608 */
609
610 ln = node_alloc();
611
612 if (!ln)
613 return NULL;
614
615 ln->fn_bit = plen;
616
617 ln->parent = pn;
618
619 ln->fn_sernum = sernum;
620
621 if (dir)
622 pn->right = ln;
623 else
624 pn->left = ln;
625
626 if (addr_bit_set(&key->addr, plen))
627 ln->right = fn;
628 else
629 ln->left = fn;
630
631 fn->parent = ln;
632 }
633 return ln;
634}
635
636/*
637 * Insert routing information in a node.
638 */
639
640static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
641 struct nl_info *info)
642{
643 struct rt6_info *iter = NULL;
644 struct rt6_info **ins;
645 int replace = (info->nlh &&
646 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
647 int add = (!info->nlh ||
648 (info->nlh->nlmsg_flags & NLM_F_CREATE));
649 int found = 0;
650
651 ins = &fn->leaf;
652
653 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
654 /*
655 * Search for duplicates
656 */
657
658 if (iter->rt6i_metric == rt->rt6i_metric) {
659 /*
660 * Same priority level
661 */
662 if (info->nlh &&
663 (info->nlh->nlmsg_flags & NLM_F_EXCL))
664 return -EEXIST;
665 if (replace) {
666 found++;
667 break;
668 }
669
670 if (iter->dst.dev == rt->dst.dev &&
671 iter->rt6i_idev == rt->rt6i_idev &&
672 ipv6_addr_equal(&iter->rt6i_gateway,
673 &rt->rt6i_gateway)) {
674 if (!(iter->rt6i_flags & RTF_EXPIRES))
675 return -EEXIST;
676 if (!(rt->rt6i_flags & RTF_EXPIRES))
677 rt6_clean_expires(iter);
678 else
679 rt6_set_expires(iter, rt->dst.expires);
680 return -EEXIST;
681 }
682 }
683
684 if (iter->rt6i_metric > rt->rt6i_metric)
685 break;
686
687 ins = &iter->dst.rt6_next;
688 }
689
690 /* Reset round-robin state, if necessary */
691 if (ins == &fn->leaf)
692 fn->rr_ptr = NULL;
693
694 /*
695 * insert node
696 */
697 if (!replace) {
698 if (!add)
699 pr_warn("NLM_F_CREATE should be set when creating new route\n");
700
701add:
702 rt->dst.rt6_next = iter;
703 *ins = rt;
704 rt->rt6i_node = fn;
705 atomic_inc(&rt->rt6i_ref);
706 inet6_rt_notify(RTM_NEWROUTE, rt, info);
707 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
708
709 if (!(fn->fn_flags & RTN_RTINFO)) {
710 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
711 fn->fn_flags |= RTN_RTINFO;
712 }
713
714 } else {
715 if (!found) {
716 if (add)
717 goto add;
718 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
719 return -ENOENT;
720 }
721 *ins = rt;
722 rt->rt6i_node = fn;
723 rt->dst.rt6_next = iter->dst.rt6_next;
724 atomic_inc(&rt->rt6i_ref);
725 inet6_rt_notify(RTM_NEWROUTE, rt, info);
726 rt6_release(iter);
727 if (!(fn->fn_flags & RTN_RTINFO)) {
728 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
729 fn->fn_flags |= RTN_RTINFO;
730 }
731 }
732
733 return 0;
734}
735
736static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
737{
738 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
739 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
740 mod_timer(&net->ipv6.ip6_fib_timer,
741 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
742}
743
744void fib6_force_start_gc(struct net *net)
745{
746 if (!timer_pending(&net->ipv6.ip6_fib_timer))
747 mod_timer(&net->ipv6.ip6_fib_timer,
748 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
749}
750
751/*
752 * Add routing information to the routing tree.
753 * <destination addr>/<source addr>
754 * with source addr info in sub-trees
755 */
756
757int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
758{
759 struct fib6_node *fn, *pn = NULL;
760 int err = -ENOMEM;
761 int allow_create = 1;
762 int replace_required = 0;
763
764 if (info->nlh) {
765 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
766 allow_create = 0;
767 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
768 replace_required = 1;
769 }
770 if (!allow_create && !replace_required)
771 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
772
773 fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
774 rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst),
775 allow_create, replace_required);
776
777 if (IS_ERR(fn)) {
778 err = PTR_ERR(fn);
779 fn = NULL;
780 }
781
782 if (!fn)
783 goto out;
784
785 pn = fn;
786
787#ifdef CONFIG_IPV6_SUBTREES
788 if (rt->rt6i_src.plen) {
789 struct fib6_node *sn;
790
791 if (!fn->subtree) {
792 struct fib6_node *sfn;
793
794 /*
795 * Create subtree.
796 *
797 * fn[main tree]
798 * |
799 * sfn[subtree root]
800 * \
801 * sn[new leaf node]
802 */
803
804 /* Create subtree root node */
805 sfn = node_alloc();
806 if (!sfn)
807 goto st_failure;
808
809 sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
810 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
811 sfn->fn_flags = RTN_ROOT;
812 sfn->fn_sernum = fib6_new_sernum();
813
814 /* Now add the first leaf node to new subtree */
815
816 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
817 sizeof(struct in6_addr), rt->rt6i_src.plen,
818 offsetof(struct rt6_info, rt6i_src),
819 allow_create, replace_required);
820
821 if (!sn) {
822 /* If it is failed, discard just allocated
823 root, and then (in st_failure) stale node
824 in main tree.
825 */
826 node_free(sfn);
827 goto st_failure;
828 }
829
830 /* Now link new subtree to main tree */
831 sfn->parent = fn;
832 fn->subtree = sfn;
833 } else {
834 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
835 sizeof(struct in6_addr), rt->rt6i_src.plen,
836 offsetof(struct rt6_info, rt6i_src),
837 allow_create, replace_required);
838
839 if (IS_ERR(sn)) {
840 err = PTR_ERR(sn);
841 sn = NULL;
842 }
843 if (!sn)
844 goto st_failure;
845 }
846
847 if (!fn->leaf) {
848 fn->leaf = rt;
849 atomic_inc(&rt->rt6i_ref);
850 }
851 fn = sn;
852 }
853#endif
854
855 err = fib6_add_rt2node(fn, rt, info);
856 if (!err) {
857 fib6_start_gc(info->nl_net, rt);
858 if (!(rt->rt6i_flags & RTF_CACHE))
859 fib6_prune_clones(info->nl_net, pn, rt);
860 }
861
862out:
863 if (err) {
864#ifdef CONFIG_IPV6_SUBTREES
865 /*
866 * If fib6_add_1 has cleared the old leaf pointer in the
867 * super-tree leaf node we have to find a new one for it.
868 */
869 if (pn != fn && pn->leaf == rt) {
870 pn->leaf = NULL;
871 atomic_dec(&rt->rt6i_ref);
872 }
873 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
874 pn->leaf = fib6_find_prefix(info->nl_net, pn);
875#if RT6_DEBUG >= 2
876 if (!pn->leaf) {
877 WARN_ON(pn->leaf == NULL);
878 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
879 }
880#endif
881 atomic_inc(&pn->leaf->rt6i_ref);
882 }
883#endif
884 dst_free(&rt->dst);
885 }
886 return err;
887
888#ifdef CONFIG_IPV6_SUBTREES
889 /* Subtree creation failed, probably main tree node
890 is orphan. If it is, shoot it.
891 */
892st_failure:
893 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
894 fib6_repair_tree(info->nl_net, fn);
895 dst_free(&rt->dst);
896 return err;
897#endif
898}
899
900/*
901 * Routing tree lookup
902 *
903 */
904
905struct lookup_args {
906 int offset; /* key offset on rt6_info */
907 const struct in6_addr *addr; /* search key */
908};
909
910static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
911 struct lookup_args *args)
912{
913 struct fib6_node *fn;
914 __be32 dir;
915
916 if (unlikely(args->offset == 0))
917 return NULL;
918
919 /*
920 * Descend on a tree
921 */
922
923 fn = root;
924
925 for (;;) {
926 struct fib6_node *next;
927
928 dir = addr_bit_set(args->addr, fn->fn_bit);
929
930 next = dir ? fn->right : fn->left;
931
932 if (next) {
933 fn = next;
934 continue;
935 }
936 break;
937 }
938
939 while (fn) {
940 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
941 struct rt6key *key;
942
943 key = (struct rt6key *) ((u8 *) fn->leaf +
944 args->offset);
945
946 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
947#ifdef CONFIG_IPV6_SUBTREES
948 if (fn->subtree)
949 fn = fib6_lookup_1(fn->subtree, args + 1);
950#endif
951 if (!fn || fn->fn_flags & RTN_RTINFO)
952 return fn;
953 }
954 }
955
956 if (fn->fn_flags & RTN_ROOT)
957 break;
958
959 fn = fn->parent;
960 }
961
962 return NULL;
963}
964
965struct fib6_node * fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
966 const struct in6_addr *saddr)
967{
968 struct fib6_node *fn;
969 struct lookup_args args[] = {
970 {
971 .offset = offsetof(struct rt6_info, rt6i_dst),
972 .addr = daddr,
973 },
974#ifdef CONFIG_IPV6_SUBTREES
975 {
976 .offset = offsetof(struct rt6_info, rt6i_src),
977 .addr = saddr,
978 },
979#endif
980 {
981 .offset = 0, /* sentinel */
982 }
983 };
984
985 fn = fib6_lookup_1(root, daddr ? args : args + 1);
986 if (!fn || fn->fn_flags & RTN_TL_ROOT)
987 fn = root;
988
989 return fn;
990}
991
992/*
993 * Get node with specified destination prefix (and source prefix,
994 * if subtrees are used)
995 */
996
997
998static struct fib6_node * fib6_locate_1(struct fib6_node *root,
999 const struct in6_addr *addr,
1000 int plen, int offset)
1001{
1002 struct fib6_node *fn;
1003
1004 for (fn = root; fn ; ) {
1005 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
1006
1007 /*
1008 * Prefix match
1009 */
1010 if (plen < fn->fn_bit ||
1011 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1012 return NULL;
1013
1014 if (plen == fn->fn_bit)
1015 return fn;
1016
1017 /*
1018 * We have more bits to go
1019 */
1020 if (addr_bit_set(addr, fn->fn_bit))
1021 fn = fn->right;
1022 else
1023 fn = fn->left;
1024 }
1025 return NULL;
1026}
1027
1028struct fib6_node * fib6_locate(struct fib6_node *root,
1029 const struct in6_addr *daddr, int dst_len,
1030 const struct in6_addr *saddr, int src_len)
1031{
1032 struct fib6_node *fn;
1033
1034 fn = fib6_locate_1(root, daddr, dst_len,
1035 offsetof(struct rt6_info, rt6i_dst));
1036
1037#ifdef CONFIG_IPV6_SUBTREES
1038 if (src_len) {
1039 WARN_ON(saddr == NULL);
1040 if (fn && fn->subtree)
1041 fn = fib6_locate_1(fn->subtree, saddr, src_len,
1042 offsetof(struct rt6_info, rt6i_src));
1043 }
1044#endif
1045
1046 if (fn && fn->fn_flags & RTN_RTINFO)
1047 return fn;
1048
1049 return NULL;
1050}
1051
1052
1053/*
1054 * Deletion
1055 *
1056 */
1057
1058static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
1059{
1060 if (fn->fn_flags & RTN_ROOT)
1061 return net->ipv6.ip6_null_entry;
1062
1063 while (fn) {
1064 if (fn->left)
1065 return fn->left->leaf;
1066 if (fn->right)
1067 return fn->right->leaf;
1068
1069 fn = FIB6_SUBTREE(fn);
1070 }
1071 return NULL;
1072}
1073
1074/*
1075 * Called to trim the tree of intermediate nodes when possible. "fn"
1076 * is the node we want to try and remove.
1077 */
1078
1079static struct fib6_node *fib6_repair_tree(struct net *net,
1080 struct fib6_node *fn)
1081{
1082 int children;
1083 int nstate;
1084 struct fib6_node *child, *pn;
1085 struct fib6_walker_t *w;
1086 int iter = 0;
1087
1088 for (;;) {
1089 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1090 iter++;
1091
1092 WARN_ON(fn->fn_flags & RTN_RTINFO);
1093 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1094 WARN_ON(fn->leaf != NULL);
1095
1096 children = 0;
1097 child = NULL;
1098 if (fn->right) child = fn->right, children |= 1;
1099 if (fn->left) child = fn->left, children |= 2;
1100
1101 if (children == 3 || FIB6_SUBTREE(fn)
1102#ifdef CONFIG_IPV6_SUBTREES
1103 /* Subtree root (i.e. fn) may have one child */
1104 || (children && fn->fn_flags & RTN_ROOT)
1105#endif
1106 ) {
1107 fn->leaf = fib6_find_prefix(net, fn);
1108#if RT6_DEBUG >= 2
1109 if (!fn->leaf) {
1110 WARN_ON(!fn->leaf);
1111 fn->leaf = net->ipv6.ip6_null_entry;
1112 }
1113#endif
1114 atomic_inc(&fn->leaf->rt6i_ref);
1115 return fn->parent;
1116 }
1117
1118 pn = fn->parent;
1119#ifdef CONFIG_IPV6_SUBTREES
1120 if (FIB6_SUBTREE(pn) == fn) {
1121 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1122 FIB6_SUBTREE(pn) = NULL;
1123 nstate = FWS_L;
1124 } else {
1125 WARN_ON(fn->fn_flags & RTN_ROOT);
1126#endif
1127 if (pn->right == fn) pn->right = child;
1128 else if (pn->left == fn) pn->left = child;
1129#if RT6_DEBUG >= 2
1130 else
1131 WARN_ON(1);
1132#endif
1133 if (child)
1134 child->parent = pn;
1135 nstate = FWS_R;
1136#ifdef CONFIG_IPV6_SUBTREES
1137 }
1138#endif
1139
1140 read_lock(&fib6_walker_lock);
1141 FOR_WALKERS(w) {
1142 if (!child) {
1143 if (w->root == fn) {
1144 w->root = w->node = NULL;
1145 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1146 } else if (w->node == fn) {
1147 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1148 w->node = pn;
1149 w->state = nstate;
1150 }
1151 } else {
1152 if (w->root == fn) {
1153 w->root = child;
1154 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1155 }
1156 if (w->node == fn) {
1157 w->node = child;
1158 if (children&2) {
1159 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1160 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1161 } else {
1162 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1163 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1164 }
1165 }
1166 }
1167 }
1168 read_unlock(&fib6_walker_lock);
1169
1170 node_free(fn);
1171 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1172 return pn;
1173
1174 rt6_release(pn->leaf);
1175 pn->leaf = NULL;
1176 fn = pn;
1177 }
1178}
1179
1180static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1181 struct nl_info *info)
1182{
1183 struct fib6_walker_t *w;
1184 struct rt6_info *rt = *rtp;
1185 struct net *net = info->nl_net;
1186
1187 RT6_TRACE("fib6_del_route\n");
1188
1189 /* Unlink it */
1190 *rtp = rt->dst.rt6_next;
1191 rt->rt6i_node = NULL;
1192 net->ipv6.rt6_stats->fib_rt_entries--;
1193 net->ipv6.rt6_stats->fib_discarded_routes++;
1194
1195 /* Reset round-robin state, if necessary */
1196 if (fn->rr_ptr == rt)
1197 fn->rr_ptr = NULL;
1198
1199 /* Adjust walkers */
1200 read_lock(&fib6_walker_lock);
1201 FOR_WALKERS(w) {
1202 if (w->state == FWS_C && w->leaf == rt) {
1203 RT6_TRACE("walker %p adjusted by delroute\n", w);
1204 w->leaf = rt->dst.rt6_next;
1205 if (!w->leaf)
1206 w->state = FWS_U;
1207 }
1208 }
1209 read_unlock(&fib6_walker_lock);
1210
1211 rt->dst.rt6_next = NULL;
1212
1213 /* If it was last route, expunge its radix tree node */
1214 if (!fn->leaf) {
1215 fn->fn_flags &= ~RTN_RTINFO;
1216 net->ipv6.rt6_stats->fib_route_nodes--;
1217 fn = fib6_repair_tree(net, fn);
1218 }
1219
1220 if (atomic_read(&rt->rt6i_ref) != 1) {
1221 /* This route is used as dummy address holder in some split
1222 * nodes. It is not leaked, but it still holds other resources,
1223 * which must be released in time. So, scan ascendant nodes
1224 * and replace dummy references to this route with references
1225 * to still alive ones.
1226 */
1227 while (fn) {
1228 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
1229 fn->leaf = fib6_find_prefix(net, fn);
1230 atomic_inc(&fn->leaf->rt6i_ref);
1231 rt6_release(rt);
1232 }
1233 fn = fn->parent;
1234 }
1235 /* No more references are possible at this point. */
1236 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1237 }
1238
1239 inet6_rt_notify(RTM_DELROUTE, rt, info);
1240 rt6_release(rt);
1241}
1242
1243int fib6_del(struct rt6_info *rt, struct nl_info *info)
1244{
1245 struct net *net = info->nl_net;
1246 struct fib6_node *fn = rt->rt6i_node;
1247 struct rt6_info **rtp;
1248
1249#if RT6_DEBUG >= 2
1250 if (rt->dst.obsolete>0) {
1251 WARN_ON(fn != NULL);
1252 return -ENOENT;
1253 }
1254#endif
1255 if (!fn || rt == net->ipv6.ip6_null_entry)
1256 return -ENOENT;
1257
1258 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1259
1260 if (!(rt->rt6i_flags & RTF_CACHE)) {
1261 struct fib6_node *pn = fn;
1262#ifdef CONFIG_IPV6_SUBTREES
1263 /* clones of this route might be in another subtree */
1264 if (rt->rt6i_src.plen) {
1265 while (!(pn->fn_flags & RTN_ROOT))
1266 pn = pn->parent;
1267 pn = pn->parent;
1268 }
1269#endif
1270 fib6_prune_clones(info->nl_net, pn, rt);
1271 }
1272
1273 /*
1274 * Walk the leaf entries looking for ourself
1275 */
1276
1277 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
1278 if (*rtp == rt) {
1279 fib6_del_route(fn, rtp, info);
1280 return 0;
1281 }
1282 }
1283 return -ENOENT;
1284}
1285
1286/*
1287 * Tree traversal function.
1288 *
1289 * Certainly, it is not interrupt safe.
1290 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1291 * It means, that we can modify tree during walking
1292 * and use this function for garbage collection, clone pruning,
1293 * cleaning tree when a device goes down etc. etc.
1294 *
1295 * It guarantees that every node will be traversed,
1296 * and that it will be traversed only once.
1297 *
1298 * Callback function w->func may return:
1299 * 0 -> continue walking.
1300 * positive value -> walking is suspended (used by tree dumps,
1301 * and probably by gc, if it will be split to several slices)
1302 * negative value -> terminate walking.
1303 *
1304 * The function itself returns:
1305 * 0 -> walk is complete.
1306 * >0 -> walk is incomplete (i.e. suspended)
1307 * <0 -> walk is terminated by an error.
1308 */
1309
1310static int fib6_walk_continue(struct fib6_walker_t *w)
1311{
1312 struct fib6_node *fn, *pn;
1313
1314 for (;;) {
1315 fn = w->node;
1316 if (!fn)
1317 return 0;
1318
1319 if (w->prune && fn != w->root &&
1320 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
1321 w->state = FWS_C;
1322 w->leaf = fn->leaf;
1323 }
1324 switch (w->state) {
1325#ifdef CONFIG_IPV6_SUBTREES
1326 case FWS_S:
1327 if (FIB6_SUBTREE(fn)) {
1328 w->node = FIB6_SUBTREE(fn);
1329 continue;
1330 }
1331 w->state = FWS_L;
1332#endif
1333 case FWS_L:
1334 if (fn->left) {
1335 w->node = fn->left;
1336 w->state = FWS_INIT;
1337 continue;
1338 }
1339 w->state = FWS_R;
1340 case FWS_R:
1341 if (fn->right) {
1342 w->node = fn->right;
1343 w->state = FWS_INIT;
1344 continue;
1345 }
1346 w->state = FWS_C;
1347 w->leaf = fn->leaf;
1348 case FWS_C:
1349 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1350 int err;
1351
1352 if (w->skip) {
1353 w->skip--;
1354 continue;
1355 }
1356
1357 err = w->func(w);
1358 if (err)
1359 return err;
1360
1361 w->count++;
1362 continue;
1363 }
1364 w->state = FWS_U;
1365 case FWS_U:
1366 if (fn == w->root)
1367 return 0;
1368 pn = fn->parent;
1369 w->node = pn;
1370#ifdef CONFIG_IPV6_SUBTREES
1371 if (FIB6_SUBTREE(pn) == fn) {
1372 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1373 w->state = FWS_L;
1374 continue;
1375 }
1376#endif
1377 if (pn->left == fn) {
1378 w->state = FWS_R;
1379 continue;
1380 }
1381 if (pn->right == fn) {
1382 w->state = FWS_C;
1383 w->leaf = w->node->leaf;
1384 continue;
1385 }
1386#if RT6_DEBUG >= 2
1387 WARN_ON(1);
1388#endif
1389 }
1390 }
1391}
1392
1393static int fib6_walk(struct fib6_walker_t *w)
1394{
1395 int res;
1396
1397 w->state = FWS_INIT;
1398 w->node = w->root;
1399
1400 fib6_walker_link(w);
1401 res = fib6_walk_continue(w);
1402 if (res <= 0)
1403 fib6_walker_unlink(w);
1404 return res;
1405}
1406
1407static int fib6_clean_node(struct fib6_walker_t *w)
1408{
1409 int res;
1410 struct rt6_info *rt;
1411 struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1412 struct nl_info info = {
1413 .nl_net = c->net,
1414 };
1415
1416 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
1417 res = c->func(rt, c->arg);
1418 if (res < 0) {
1419 w->leaf = rt;
1420 res = fib6_del(rt, &info);
1421 if (res) {
1422#if RT6_DEBUG >= 2
1423 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1424 __func__, rt, rt->rt6i_node, res);
1425#endif
1426 continue;
1427 }
1428 return 0;
1429 }
1430 WARN_ON(res != 0);
1431 }
1432 w->leaf = rt;
1433 return 0;
1434}
1435
1436/*
1437 * Convenient frontend to tree walker.
1438 *
1439 * func is called on each route.
1440 * It may return -1 -> delete this route.
1441 * 0 -> continue walking
1442 *
1443 * prune==1 -> only immediate children of node (certainly,
1444 * ignoring pure split nodes) will be scanned.
1445 */
1446
1447static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1448 int (*func)(struct rt6_info *, void *arg),
1449 int prune, void *arg)
1450{
1451 struct fib6_cleaner_t c;
1452
1453 c.w.root = root;
1454 c.w.func = fib6_clean_node;
1455 c.w.prune = prune;
1456 c.w.count = 0;
1457 c.w.skip = 0;
1458 c.func = func;
1459 c.arg = arg;
1460 c.net = net;
1461
1462 fib6_walk(&c.w);
1463}
1464
1465void fib6_clean_all_ro(struct net *net, int (*func)(struct rt6_info *, void *arg),
1466 int prune, void *arg)
1467{
1468 struct fib6_table *table;
1469 struct hlist_node *node;
1470 struct hlist_head *head;
1471 unsigned int h;
1472
1473 rcu_read_lock();
1474 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1475 head = &net->ipv6.fib_table_hash[h];
1476 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1477 read_lock_bh(&table->tb6_lock);
1478 fib6_clean_tree(net, &table->tb6_root,
1479 func, prune, arg);
1480 read_unlock_bh(&table->tb6_lock);
1481 }
1482 }
1483 rcu_read_unlock();
1484}
1485void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1486 int prune, void *arg)
1487{
1488 struct fib6_table *table;
1489 struct hlist_node *node;
1490 struct hlist_head *head;
1491 unsigned int h;
1492
1493 rcu_read_lock();
1494 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1495 head = &net->ipv6.fib_table_hash[h];
1496 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1497 write_lock_bh(&table->tb6_lock);
1498 fib6_clean_tree(net, &table->tb6_root,
1499 func, prune, arg);
1500 write_unlock_bh(&table->tb6_lock);
1501 }
1502 }
1503 rcu_read_unlock();
1504}
1505
1506static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1507{
1508 if (rt->rt6i_flags & RTF_CACHE) {
1509 RT6_TRACE("pruning clone %p\n", rt);
1510 return -1;
1511 }
1512
1513 return 0;
1514}
1515
1516static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1517 struct rt6_info *rt)
1518{
1519 fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1520}
1521
1522/*
1523 * Garbage collection
1524 */
1525
1526static struct fib6_gc_args
1527{
1528 int timeout;
1529 int more;
1530} gc_args;
1531
1532static int fib6_age(struct rt6_info *rt, void *arg)
1533{
1534 unsigned long now = jiffies;
1535
1536 /*
1537 * check addrconf expiration here.
1538 * Routes are expired even if they are in use.
1539 *
1540 * Also age clones. Note, that clones are aged out
1541 * only if they are not in use now.
1542 */
1543
1544 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
1545 if (time_after(now, rt->dst.expires)) {
1546 RT6_TRACE("expiring %p\n", rt);
1547 return -1;
1548 }
1549 gc_args.more++;
1550 } else if (rt->rt6i_flags & RTF_CACHE) {
1551 if (atomic_read(&rt->dst.__refcnt) == 0 &&
1552 time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
1553 RT6_TRACE("aging clone %p\n", rt);
1554 return -1;
1555 } else if (rt->rt6i_flags & RTF_GATEWAY) {
1556 struct neighbour *neigh;
1557 __u8 neigh_flags = 0;
1558
1559 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
1560 if (neigh) {
1561 neigh_flags = neigh->flags;
1562 neigh_release(neigh);
1563 }
1564 if (!(neigh_flags & NTF_ROUTER)) {
1565 RT6_TRACE("purging route %p via non-router but gateway\n",
1566 rt);
1567 return -1;
1568 }
1569 }
1570 gc_args.more++;
1571 }
1572
1573 return 0;
1574}
1575
1576static DEFINE_SPINLOCK(fib6_gc_lock);
1577
1578void fib6_run_gc(unsigned long expires, struct net *net)
1579{
1580 if (expires != ~0UL) {
1581 spin_lock_bh(&fib6_gc_lock);
1582 gc_args.timeout = expires ? (int)expires :
1583 net->ipv6.sysctl.ip6_rt_gc_interval;
1584 } else {
1585 if (!spin_trylock_bh(&fib6_gc_lock)) {
1586 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1587 return;
1588 }
1589 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1590 }
1591
1592 gc_args.more = icmp6_dst_gc();
1593
1594 fib6_clean_all(net, fib6_age, 0, NULL);
1595
1596 if (gc_args.more)
1597 mod_timer(&net->ipv6.ip6_fib_timer,
1598 round_jiffies(jiffies
1599 + net->ipv6.sysctl.ip6_rt_gc_interval));
1600 else
1601 del_timer(&net->ipv6.ip6_fib_timer);
1602 spin_unlock_bh(&fib6_gc_lock);
1603}
1604
1605static void fib6_gc_timer_cb(unsigned long arg)
1606{
1607 fib6_run_gc(0, (struct net *)arg);
1608}
1609
1610static int __net_init fib6_net_init(struct net *net)
1611{
1612 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
1613
1614 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1615
1616 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1617 if (!net->ipv6.rt6_stats)
1618 goto out_timer;
1619
1620 /* Avoid false sharing : Use at least a full cache line */
1621 size = max_t(size_t, size, L1_CACHE_BYTES);
1622
1623 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
1624 if (!net->ipv6.fib_table_hash)
1625 goto out_rt6_stats;
1626
1627 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1628 GFP_KERNEL);
1629 if (!net->ipv6.fib6_main_tbl)
1630 goto out_fib_table_hash;
1631
1632 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1633 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1634 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1635 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1636
1637#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1638 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1639 GFP_KERNEL);
1640 if (!net->ipv6.fib6_local_tbl)
1641 goto out_fib6_main_tbl;
1642 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1643 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1644 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1645 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1646#endif
1647 fib6_tables_init(net);
1648
1649 return 0;
1650
1651#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1652out_fib6_main_tbl:
1653 kfree(net->ipv6.fib6_main_tbl);
1654#endif
1655out_fib_table_hash:
1656 kfree(net->ipv6.fib_table_hash);
1657out_rt6_stats:
1658 kfree(net->ipv6.rt6_stats);
1659out_timer:
1660 return -ENOMEM;
1661 }
1662
1663static void fib6_net_exit(struct net *net)
1664{
1665 rt6_ifdown(net, NULL);
1666 del_timer_sync(&net->ipv6.ip6_fib_timer);
1667
1668#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1669 kfree(net->ipv6.fib6_local_tbl);
1670#endif
1671 kfree(net->ipv6.fib6_main_tbl);
1672 kfree(net->ipv6.fib_table_hash);
1673 kfree(net->ipv6.rt6_stats);
1674}
1675
1676static struct pernet_operations fib6_net_ops = {
1677 .init = fib6_net_init,
1678 .exit = fib6_net_exit,
1679};
1680
1681int __init fib6_init(void)
1682{
1683 int ret = -ENOMEM;
1684
1685 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1686 sizeof(struct fib6_node),
1687 0, SLAB_HWCACHE_ALIGN,
1688 NULL);
1689 if (!fib6_node_kmem)
1690 goto out;
1691
1692 ret = register_pernet_subsys(&fib6_net_ops);
1693 if (ret)
1694 goto out_kmem_cache_create;
1695
1696 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
1697 NULL);
1698 if (ret)
1699 goto out_unregister_subsys;
1700out:
1701 return ret;
1702
1703out_unregister_subsys:
1704 unregister_pernet_subsys(&fib6_net_ops);
1705out_kmem_cache_create:
1706 kmem_cache_destroy(fib6_node_kmem);
1707 goto out;
1708}
1709
1710void fib6_gc_cleanup(void)
1711{
1712 unregister_pernet_subsys(&fib6_net_ops);
1713 kmem_cache_destroy(fib6_node_kmem);
1714}