[PATCH] drivers/char/vc_screen.c: proper prototypes
[linux-block.git] / net / ipv6 / ip6_fib.c
CommitLineData
1da177e4
LT
1/*
2 * Linux INET6 implementation
3 * Forwarding Information Database
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * $Id: ip6_fib.c,v 1.25 2001/10/31 21:55:55 davem Exp $
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 */
15
16/*
17 * Changes:
18 * Yuji SEKIYA @USAGI: Support default route on router node;
19 * remove ip6_null_entry from the top of
20 * routing table.
c0bece9f 21 * Ville Nuorvala: Fixed routing subtrees.
1da177e4 22 */
1da177e4
LT
23#include <linux/errno.h>
24#include <linux/types.h>
25#include <linux/net.h>
26#include <linux/route.h>
27#include <linux/netdevice.h>
28#include <linux/in6.h>
29#include <linux/init.h>
c71099ac 30#include <linux/list.h>
1da177e4
LT
31
32#ifdef CONFIG_PROC_FS
33#include <linux/proc_fs.h>
34#endif
35
36#include <net/ipv6.h>
37#include <net/ndisc.h>
38#include <net/addrconf.h>
39
40#include <net/ip6_fib.h>
41#include <net/ip6_route.h>
42
43#define RT6_DEBUG 2
44
45#if RT6_DEBUG >= 3
46#define RT6_TRACE(x...) printk(KERN_DEBUG x)
47#else
48#define RT6_TRACE(x...) do { ; } while (0)
49#endif
50
51struct rt6_statistics rt6_stats;
52
e18b890b 53static struct kmem_cache * fib6_node_kmem __read_mostly;
1da177e4
LT
54
55enum fib_walk_state_t
56{
57#ifdef CONFIG_IPV6_SUBTREES
58 FWS_S,
59#endif
60 FWS_L,
61 FWS_R,
62 FWS_C,
63 FWS_U
64};
65
66struct fib6_cleaner_t
67{
68 struct fib6_walker_t w;
69 int (*func)(struct rt6_info *, void *arg);
70 void *arg;
71};
72
90d41122 73static DEFINE_RWLOCK(fib6_walker_lock);
1da177e4
LT
74
75#ifdef CONFIG_IPV6_SUBTREES
76#define FWS_INIT FWS_S
1da177e4
LT
77#else
78#define FWS_INIT FWS_L
1da177e4
LT
79#endif
80
81static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt);
66729e18 82static struct rt6_info * fib6_find_prefix(struct fib6_node *fn);
1da177e4 83static struct fib6_node * fib6_repair_tree(struct fib6_node *fn);
90d41122
AB
84static int fib6_walk(struct fib6_walker_t *w);
85static int fib6_walk_continue(struct fib6_walker_t *w);
1da177e4
LT
86
87/*
88 * A routing update causes an increase of the serial number on the
89 * affected subtree. This allows for cached routes to be asynchronously
90 * tested when modifications are made to the destination cache as a
91 * result of redirects, path MTU changes, etc.
92 */
93
94static __u32 rt_sernum;
95
8d06afab 96static DEFINE_TIMER(ip6_fib_timer, fib6_run_gc, 0, 0);
1da177e4 97
90d41122 98static struct fib6_walker_t fib6_walker_list = {
1da177e4
LT
99 .prev = &fib6_walker_list,
100 .next = &fib6_walker_list,
101};
102
103#define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next)
104
90d41122
AB
105static inline void fib6_walker_link(struct fib6_walker_t *w)
106{
107 write_lock_bh(&fib6_walker_lock);
108 w->next = fib6_walker_list.next;
109 w->prev = &fib6_walker_list;
110 w->next->prev = w;
111 w->prev->next = w;
112 write_unlock_bh(&fib6_walker_lock);
113}
114
115static inline void fib6_walker_unlink(struct fib6_walker_t *w)
116{
117 write_lock_bh(&fib6_walker_lock);
118 w->next->prev = w->prev;
119 w->prev->next = w->next;
120 w->prev = w->next = w;
121 write_unlock_bh(&fib6_walker_lock);
122}
1da177e4
LT
123static __inline__ u32 fib6_new_sernum(void)
124{
125 u32 n = ++rt_sernum;
126 if ((__s32)n <= 0)
127 rt_sernum = n = 1;
128 return n;
129}
130
131/*
132 * Auxiliary address test functions for the radix tree.
133 *
134 * These assume a 32bit processor (although it will work on
135 * 64bit processors)
136 */
137
138/*
139 * test bit
140 */
141
e69a4adc 142static __inline__ __be32 addr_bit_set(void *token, int fn_bit)
1da177e4 143{
e69a4adc 144 __be32 *addr = token;
1da177e4
LT
145
146 return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5];
147}
148
1da177e4
LT
149static __inline__ struct fib6_node * node_alloc(void)
150{
151 struct fib6_node *fn;
152
54e6ecb2 153 if ((fn = kmem_cache_alloc(fib6_node_kmem, GFP_ATOMIC)) != NULL)
1da177e4
LT
154 memset(fn, 0, sizeof(struct fib6_node));
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->u.dst);
168}
169
c71099ac
TG
170static struct fib6_table fib6_main_tbl = {
171 .tb6_id = RT6_TABLE_MAIN,
c71099ac
TG
172 .tb6_root = {
173 .leaf = &ip6_null_entry,
174 .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO,
175 },
176};
177
178#ifdef CONFIG_IPV6_MULTIPLE_TABLES
1b43af54
PM
179#define FIB_TABLE_HASHSZ 256
180#else
181#define FIB_TABLE_HASHSZ 1
182#endif
183static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];
184
185static void fib6_link_table(struct fib6_table *tb)
186{
187 unsigned int h;
188
375216ad
TG
189 /*
190 * Initialize table lock at a single place to give lockdep a key,
191 * tables aren't visible prior to being linked to the list.
192 */
193 rwlock_init(&tb->tb6_lock);
194
1b43af54
PM
195 h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1);
196
197 /*
198 * No protection necessary, this is the only list mutatation
199 * operation, tables never disappear once they exist.
200 */
201 hlist_add_head_rcu(&tb->tb6_hlist, &fib_table_hash[h]);
202}
c71099ac 203
1b43af54 204#ifdef CONFIG_IPV6_MULTIPLE_TABLES
101367c2
TG
205static struct fib6_table fib6_local_tbl = {
206 .tb6_id = RT6_TABLE_LOCAL,
101367c2
TG
207 .tb6_root = {
208 .leaf = &ip6_null_entry,
209 .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO,
210 },
211};
212
c71099ac
TG
213static struct fib6_table *fib6_alloc_table(u32 id)
214{
215 struct fib6_table *table;
216
217 table = kzalloc(sizeof(*table), GFP_ATOMIC);
218 if (table != NULL) {
219 table->tb6_id = id;
c71099ac
TG
220 table->tb6_root.leaf = &ip6_null_entry;
221 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
222 }
223
224 return table;
225}
226
c71099ac
TG
227struct fib6_table *fib6_new_table(u32 id)
228{
229 struct fib6_table *tb;
230
231 if (id == 0)
232 id = RT6_TABLE_MAIN;
233 tb = fib6_get_table(id);
234 if (tb)
235 return tb;
236
237 tb = fib6_alloc_table(id);
238 if (tb != NULL)
239 fib6_link_table(tb);
240
241 return tb;
242}
243
244struct fib6_table *fib6_get_table(u32 id)
245{
246 struct fib6_table *tb;
247 struct hlist_node *node;
248 unsigned int h;
249
250 if (id == 0)
251 id = RT6_TABLE_MAIN;
252 h = id & (FIB_TABLE_HASHSZ - 1);
253 rcu_read_lock();
254 hlist_for_each_entry_rcu(tb, node, &fib_table_hash[h], tb6_hlist) {
255 if (tb->tb6_id == id) {
256 rcu_read_unlock();
257 return tb;
258 }
259 }
260 rcu_read_unlock();
261
262 return NULL;
263}
264
c71099ac
TG
265static void __init fib6_tables_init(void)
266{
267 fib6_link_table(&fib6_main_tbl);
101367c2 268 fib6_link_table(&fib6_local_tbl);
c71099ac
TG
269}
270
271#else
272
273struct fib6_table *fib6_new_table(u32 id)
274{
275 return fib6_get_table(id);
276}
277
278struct fib6_table *fib6_get_table(u32 id)
279{
280 return &fib6_main_tbl;
281}
282
283struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
284 pol_lookup_t lookup)
285{
286 return (struct dst_entry *) lookup(&fib6_main_tbl, fl, flags);
287}
288
289static void __init fib6_tables_init(void)
290{
1b43af54 291 fib6_link_table(&fib6_main_tbl);
c71099ac
TG
292}
293
294#endif
295
1b43af54
PM
296static int fib6_dump_node(struct fib6_walker_t *w)
297{
298 int res;
299 struct rt6_info *rt;
300
301 for (rt = w->leaf; rt; rt = rt->u.next) {
302 res = rt6_dump_route(rt, w->args);
303 if (res < 0) {
304 /* Frame is full, suspend walking */
305 w->leaf = rt;
306 return 1;
307 }
308 BUG_TRAP(res!=0);
309 }
310 w->leaf = NULL;
311 return 0;
312}
313
314static void fib6_dump_end(struct netlink_callback *cb)
315{
316 struct fib6_walker_t *w = (void*)cb->args[2];
317
318 if (w) {
319 cb->args[2] = 0;
320 kfree(w);
321 }
322 cb->done = (void*)cb->args[3];
323 cb->args[1] = 3;
324}
325
326static int fib6_dump_done(struct netlink_callback *cb)
327{
328 fib6_dump_end(cb);
329 return cb->done ? cb->done(cb) : 0;
330}
331
332static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
333 struct netlink_callback *cb)
334{
335 struct fib6_walker_t *w;
336 int res;
337
338 w = (void *)cb->args[2];
339 w->root = &table->tb6_root;
340
341 if (cb->args[4] == 0) {
342 read_lock_bh(&table->tb6_lock);
343 res = fib6_walk(w);
344 read_unlock_bh(&table->tb6_lock);
345 if (res > 0)
346 cb->args[4] = 1;
347 } else {
348 read_lock_bh(&table->tb6_lock);
349 res = fib6_walk_continue(w);
350 read_unlock_bh(&table->tb6_lock);
351 if (res != 0) {
352 if (res < 0)
353 fib6_walker_unlink(w);
354 goto end;
355 }
356 fib6_walker_unlink(w);
357 cb->args[4] = 0;
358 }
359end:
360 return res;
361}
362
363int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
364{
365 unsigned int h, s_h;
366 unsigned int e = 0, s_e;
367 struct rt6_rtnl_dump_arg arg;
368 struct fib6_walker_t *w;
369 struct fib6_table *tb;
370 struct hlist_node *node;
371 int res = 0;
372
373 s_h = cb->args[0];
374 s_e = cb->args[1];
375
376 w = (void *)cb->args[2];
377 if (w == NULL) {
378 /* New dump:
379 *
380 * 1. hook callback destructor.
381 */
382 cb->args[3] = (long)cb->done;
383 cb->done = fib6_dump_done;
384
385 /*
386 * 2. allocate and initialize walker.
387 */
388 w = kzalloc(sizeof(*w), GFP_ATOMIC);
389 if (w == NULL)
390 return -ENOMEM;
391 w->func = fib6_dump_node;
392 cb->args[2] = (long)w;
393 }
394
395 arg.skb = skb;
396 arg.cb = cb;
397 w->args = &arg;
398
399 for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
400 e = 0;
401 hlist_for_each_entry(tb, node, &fib_table_hash[h], 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 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}
1da177e4
LT
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)
432{
433 struct fib6_node *fn, *in, *ln;
434 struct fib6_node *pn = NULL;
435 struct rt6key *key;
436 int bit;
e69a4adc 437 __be32 dir = 0;
1da177e4
LT
438 __u32 sernum = fib6_new_sernum();
439
440 RT6_TRACE("fib6_add_1\n");
441
442 /* insert node in tree */
443
444 fn = root;
445
446 do {
447 key = (struct rt6key *)((u8 *)fn->leaf + offset);
448
449 /*
450 * Prefix match
451 */
452 if (plen < fn->fn_bit ||
453 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
454 goto insert_above;
455
456 /*
457 * Exact match ?
458 */
459
460 if (plen == fn->fn_bit) {
461 /* clean up an intermediate node */
462 if ((fn->fn_flags & RTN_RTINFO) == 0) {
463 rt6_release(fn->leaf);
464 fn->leaf = NULL;
465 }
466
467 fn->fn_sernum = sernum;
468
469 return fn;
470 }
471
472 /*
473 * We have more bits to go
474 */
475
476 /* Try to walk down on tree. */
477 fn->fn_sernum = sernum;
478 dir = addr_bit_set(addr, fn->fn_bit);
479 pn = fn;
480 fn = dir ? fn->right: fn->left;
481 } while (fn);
482
483 /*
484 * We walked to the bottom of tree.
485 * Create new leaf node without children.
486 */
487
488 ln = node_alloc();
489
490 if (ln == NULL)
491 return NULL;
492 ln->fn_bit = plen;
493
494 ln->parent = pn;
495 ln->fn_sernum = sernum;
496
497 if (dir)
498 pn->right = ln;
499 else
500 pn->left = ln;
501
502 return ln;
503
504
505insert_above:
506 /*
507 * split since we don't have a common prefix anymore or
508 * we have a less significant route.
509 * we've to insert an intermediate node on the list
510 * this new node will point to the one we need to create
511 * and the current
512 */
513
514 pn = fn->parent;
515
516 /* find 1st bit in difference between the 2 addrs.
517
971f359d 518 See comment in __ipv6_addr_diff: bit may be an invalid value,
1da177e4
LT
519 but if it is >= plen, the value is ignored in any case.
520 */
521
971f359d 522 bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
1da177e4
LT
523
524 /*
525 * (intermediate)[in]
526 * / \
527 * (new leaf node)[ln] (old node)[fn]
528 */
529 if (plen > bit) {
530 in = node_alloc();
531 ln = node_alloc();
532
533 if (in == NULL || ln == NULL) {
534 if (in)
535 node_free(in);
536 if (ln)
537 node_free(ln);
538 return NULL;
539 }
540
541 /*
542 * new intermediate node.
543 * RTN_RTINFO will
544 * be off since that an address that chooses one of
545 * the branches would not match less specific routes
546 * in the other branch
547 */
548
549 in->fn_bit = bit;
550
551 in->parent = pn;
552 in->leaf = fn->leaf;
553 atomic_inc(&in->leaf->rt6i_ref);
554
555 in->fn_sernum = sernum;
556
557 /* update parent pointer */
558 if (dir)
559 pn->right = in;
560 else
561 pn->left = in;
562
563 ln->fn_bit = plen;
564
565 ln->parent = in;
566 fn->parent = in;
567
568 ln->fn_sernum = sernum;
569
570 if (addr_bit_set(addr, bit)) {
571 in->right = ln;
572 in->left = fn;
573 } else {
574 in->left = ln;
575 in->right = fn;
576 }
577 } else { /* plen <= bit */
578
579 /*
580 * (new leaf node)[ln]
581 * / \
582 * (old node)[fn] NULL
583 */
584
585 ln = node_alloc();
586
587 if (ln == NULL)
588 return NULL;
589
590 ln->fn_bit = plen;
591
592 ln->parent = pn;
593
594 ln->fn_sernum = sernum;
595
596 if (dir)
597 pn->right = ln;
598 else
599 pn->left = ln;
600
601 if (addr_bit_set(&key->addr, plen))
602 ln->right = fn;
603 else
604 ln->left = fn;
605
606 fn->parent = ln;
607 }
608 return ln;
609}
610
611/*
612 * Insert routing information in a node.
613 */
614
615static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
86872cb5 616 struct nl_info *info)
1da177e4
LT
617{
618 struct rt6_info *iter = NULL;
619 struct rt6_info **ins;
620
621 ins = &fn->leaf;
622
623 if (fn->fn_flags&RTN_TL_ROOT &&
624 fn->leaf == &ip6_null_entry &&
625 !(rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ){
626 fn->leaf = rt;
627 rt->u.next = NULL;
628 goto out;
629 }
630
631 for (iter = fn->leaf; iter; iter=iter->u.next) {
632 /*
633 * Search for duplicates
634 */
635
636 if (iter->rt6i_metric == rt->rt6i_metric) {
637 /*
638 * Same priority level
639 */
640
641 if (iter->rt6i_dev == rt->rt6i_dev &&
642 iter->rt6i_idev == rt->rt6i_idev &&
643 ipv6_addr_equal(&iter->rt6i_gateway,
644 &rt->rt6i_gateway)) {
645 if (!(iter->rt6i_flags&RTF_EXPIRES))
646 return -EEXIST;
647 iter->rt6i_expires = rt->rt6i_expires;
648 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
649 iter->rt6i_flags &= ~RTF_EXPIRES;
650 iter->rt6i_expires = 0;
651 }
652 return -EEXIST;
653 }
654 }
655
656 if (iter->rt6i_metric > rt->rt6i_metric)
657 break;
658
659 ins = &iter->u.next;
660 }
661
662 /*
663 * insert node
664 */
665
666out:
667 rt->u.next = iter;
668 *ins = rt;
669 rt->rt6i_node = fn;
670 atomic_inc(&rt->rt6i_ref);
86872cb5 671 inet6_rt_notify(RTM_NEWROUTE, rt, info);
1da177e4
LT
672 rt6_stats.fib_rt_entries++;
673
674 if ((fn->fn_flags & RTN_RTINFO) == 0) {
675 rt6_stats.fib_route_nodes++;
676 fn->fn_flags |= RTN_RTINFO;
677 }
678
679 return 0;
680}
681
682static __inline__ void fib6_start_gc(struct rt6_info *rt)
683{
684 if (ip6_fib_timer.expires == 0 &&
685 (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
686 mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval);
687}
688
689void fib6_force_start_gc(void)
690{
691 if (ip6_fib_timer.expires == 0)
692 mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval);
693}
694
695/*
696 * Add routing information to the routing tree.
697 * <destination addr>/<source addr>
698 * with source addr info in sub-trees
699 */
700
86872cb5 701int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
1da177e4 702{
66729e18 703 struct fib6_node *fn, *pn = NULL;
1da177e4
LT
704 int err = -ENOMEM;
705
706 fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
707 rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
708
709 if (fn == NULL)
710 goto out;
711
66729e18
YH
712 pn = fn;
713
1da177e4
LT
714#ifdef CONFIG_IPV6_SUBTREES
715 if (rt->rt6i_src.plen) {
716 struct fib6_node *sn;
717
718 if (fn->subtree == NULL) {
719 struct fib6_node *sfn;
720
721 /*
722 * Create subtree.
723 *
724 * fn[main tree]
725 * |
726 * sfn[subtree root]
727 * \
728 * sn[new leaf node]
729 */
730
731 /* Create subtree root node */
732 sfn = node_alloc();
733 if (sfn == NULL)
734 goto st_failure;
735
736 sfn->leaf = &ip6_null_entry;
737 atomic_inc(&ip6_null_entry.rt6i_ref);
738 sfn->fn_flags = RTN_ROOT;
739 sfn->fn_sernum = fib6_new_sernum();
740
741 /* Now add the first leaf node to new subtree */
742
743 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
744 sizeof(struct in6_addr), rt->rt6i_src.plen,
745 offsetof(struct rt6_info, rt6i_src));
746
747 if (sn == NULL) {
748 /* If it is failed, discard just allocated
749 root, and then (in st_failure) stale node
750 in main tree.
751 */
752 node_free(sfn);
753 goto st_failure;
754 }
755
756 /* Now link new subtree to main tree */
757 sfn->parent = fn;
758 fn->subtree = sfn;
1da177e4
LT
759 } else {
760 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
761 sizeof(struct in6_addr), rt->rt6i_src.plen,
762 offsetof(struct rt6_info, rt6i_src));
763
764 if (sn == NULL)
765 goto st_failure;
766 }
767
66729e18
YH
768 if (fn->leaf == NULL) {
769 fn->leaf = rt;
770 atomic_inc(&rt->rt6i_ref);
771 }
1da177e4
LT
772 fn = sn;
773 }
774#endif
775
86872cb5 776 err = fib6_add_rt2node(fn, rt, info);
1da177e4
LT
777
778 if (err == 0) {
779 fib6_start_gc(rt);
780 if (!(rt->rt6i_flags&RTF_CACHE))
2285adc1 781 fib6_prune_clones(pn, rt);
1da177e4
LT
782 }
783
784out:
66729e18
YH
785 if (err) {
786#ifdef CONFIG_IPV6_SUBTREES
787 /*
788 * If fib6_add_1 has cleared the old leaf pointer in the
789 * super-tree leaf node we have to find a new one for it.
790 */
791 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
792 pn->leaf = fib6_find_prefix(pn);
793#if RT6_DEBUG >= 2
794 if (!pn->leaf) {
795 BUG_TRAP(pn->leaf != NULL);
796 pn->leaf = &ip6_null_entry;
797 }
798#endif
799 atomic_inc(&pn->leaf->rt6i_ref);
800 }
801#endif
1da177e4 802 dst_free(&rt->u.dst);
66729e18 803 }
1da177e4
LT
804 return err;
805
806#ifdef CONFIG_IPV6_SUBTREES
807 /* Subtree creation failed, probably main tree node
808 is orphan. If it is, shoot it.
809 */
810st_failure:
811 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
812 fib6_repair_tree(fn);
813 dst_free(&rt->u.dst);
814 return err;
815#endif
816}
817
818/*
819 * Routing tree lookup
820 *
821 */
822
823struct lookup_args {
824 int offset; /* key offset on rt6_info */
825 struct in6_addr *addr; /* search key */
826};
827
828static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
829 struct lookup_args *args)
830{
831 struct fib6_node *fn;
e69a4adc 832 __be32 dir;
1da177e4 833
825e288e
YH
834 if (unlikely(args->offset == 0))
835 return NULL;
836
1da177e4
LT
837 /*
838 * Descend on a tree
839 */
840
841 fn = root;
842
843 for (;;) {
844 struct fib6_node *next;
845
846 dir = addr_bit_set(args->addr, fn->fn_bit);
847
848 next = dir ? fn->right : fn->left;
849
850 if (next) {
851 fn = next;
852 continue;
853 }
854
855 break;
856 }
857
3fc5e044 858 while(fn) {
7fc33165 859 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
1da177e4
LT
860 struct rt6key *key;
861
862 key = (struct rt6key *) ((u8 *) fn->leaf +
863 args->offset);
864
3fc5e044
YH
865 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
866#ifdef CONFIG_IPV6_SUBTREES
867 if (fn->subtree)
868 fn = fib6_lookup_1(fn->subtree, args + 1);
869#endif
870 if (!fn || fn->fn_flags & RTN_RTINFO)
871 return fn;
872 }
1da177e4
LT
873 }
874
3fc5e044
YH
875 if (fn->fn_flags & RTN_ROOT)
876 break;
877
1da177e4
LT
878 fn = fn->parent;
879 }
880
881 return NULL;
882}
883
884struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr,
885 struct in6_addr *saddr)
886{
1da177e4 887 struct fib6_node *fn;
825e288e
YH
888 struct lookup_args args[] = {
889 {
890 .offset = offsetof(struct rt6_info, rt6i_dst),
891 .addr = daddr,
892 },
1da177e4 893#ifdef CONFIG_IPV6_SUBTREES
825e288e
YH
894 {
895 .offset = offsetof(struct rt6_info, rt6i_src),
896 .addr = saddr,
897 },
1da177e4 898#endif
825e288e
YH
899 {
900 .offset = 0, /* sentinel */
901 }
902 };
1da177e4 903
fefc2a6c 904 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1da177e4
LT
905
906 if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
907 fn = root;
908
909 return fn;
910}
911
912/*
913 * Get node with specified destination prefix (and source prefix,
914 * if subtrees are used)
915 */
916
917
918static struct fib6_node * fib6_locate_1(struct fib6_node *root,
919 struct in6_addr *addr,
920 int plen, int offset)
921{
922 struct fib6_node *fn;
923
924 for (fn = root; fn ; ) {
925 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
926
927 /*
928 * Prefix match
929 */
930 if (plen < fn->fn_bit ||
931 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
932 return NULL;
933
934 if (plen == fn->fn_bit)
935 return fn;
936
937 /*
938 * We have more bits to go
939 */
940 if (addr_bit_set(addr, fn->fn_bit))
941 fn = fn->right;
942 else
943 fn = fn->left;
944 }
945 return NULL;
946}
947
948struct fib6_node * fib6_locate(struct fib6_node *root,
949 struct in6_addr *daddr, int dst_len,
950 struct in6_addr *saddr, int src_len)
951{
952 struct fib6_node *fn;
953
954 fn = fib6_locate_1(root, daddr, dst_len,
955 offsetof(struct rt6_info, rt6i_dst));
956
957#ifdef CONFIG_IPV6_SUBTREES
958 if (src_len) {
959 BUG_TRAP(saddr!=NULL);
3fc5e044
YH
960 if (fn && fn->subtree)
961 fn = fib6_locate_1(fn->subtree, saddr, src_len,
1da177e4
LT
962 offsetof(struct rt6_info, rt6i_src));
963 }
964#endif
965
966 if (fn && fn->fn_flags&RTN_RTINFO)
967 return fn;
968
969 return NULL;
970}
971
972
973/*
974 * Deletion
975 *
976 */
977
978static struct rt6_info * fib6_find_prefix(struct fib6_node *fn)
979{
980 if (fn->fn_flags&RTN_ROOT)
981 return &ip6_null_entry;
982
983 while(fn) {
984 if(fn->left)
985 return fn->left->leaf;
986
987 if(fn->right)
988 return fn->right->leaf;
989
7fc33165 990 fn = FIB6_SUBTREE(fn);
1da177e4
LT
991 }
992 return NULL;
993}
994
995/*
996 * Called to trim the tree of intermediate nodes when possible. "fn"
997 * is the node we want to try and remove.
998 */
999
1000static struct fib6_node * fib6_repair_tree(struct fib6_node *fn)
1001{
1002 int children;
1003 int nstate;
1004 struct fib6_node *child, *pn;
1005 struct fib6_walker_t *w;
1006 int iter = 0;
1007
1008 for (;;) {
1009 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1010 iter++;
1011
1012 BUG_TRAP(!(fn->fn_flags&RTN_RTINFO));
1013 BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT));
1014 BUG_TRAP(fn->leaf==NULL);
1015
1016 children = 0;
1017 child = NULL;
1018 if (fn->right) child = fn->right, children |= 1;
1019 if (fn->left) child = fn->left, children |= 2;
1020
7fc33165 1021 if (children == 3 || FIB6_SUBTREE(fn)
1da177e4
LT
1022#ifdef CONFIG_IPV6_SUBTREES
1023 /* Subtree root (i.e. fn) may have one child */
1024 || (children && fn->fn_flags&RTN_ROOT)
1025#endif
1026 ) {
1027 fn->leaf = fib6_find_prefix(fn);
1028#if RT6_DEBUG >= 2
1029 if (fn->leaf==NULL) {
1030 BUG_TRAP(fn->leaf);
1031 fn->leaf = &ip6_null_entry;
1032 }
1033#endif
1034 atomic_inc(&fn->leaf->rt6i_ref);
1035 return fn->parent;
1036 }
1037
1038 pn = fn->parent;
1039#ifdef CONFIG_IPV6_SUBTREES
7fc33165 1040 if (FIB6_SUBTREE(pn) == fn) {
1da177e4 1041 BUG_TRAP(fn->fn_flags&RTN_ROOT);
7fc33165 1042 FIB6_SUBTREE(pn) = NULL;
1da177e4
LT
1043 nstate = FWS_L;
1044 } else {
1045 BUG_TRAP(!(fn->fn_flags&RTN_ROOT));
1046#endif
1047 if (pn->right == fn) pn->right = child;
1048 else if (pn->left == fn) pn->left = child;
1049#if RT6_DEBUG >= 2
1050 else BUG_TRAP(0);
1051#endif
1052 if (child)
1053 child->parent = pn;
1054 nstate = FWS_R;
1055#ifdef CONFIG_IPV6_SUBTREES
1056 }
1057#endif
1058
1059 read_lock(&fib6_walker_lock);
1060 FOR_WALKERS(w) {
1061 if (child == NULL) {
1062 if (w->root == fn) {
1063 w->root = w->node = NULL;
1064 RT6_TRACE("W %p adjusted by delroot 1\n", w);
1065 } else if (w->node == fn) {
1066 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1067 w->node = pn;
1068 w->state = nstate;
1069 }
1070 } else {
1071 if (w->root == fn) {
1072 w->root = child;
1073 RT6_TRACE("W %p adjusted by delroot 2\n", w);
1074 }
1075 if (w->node == fn) {
1076 w->node = child;
1077 if (children&2) {
1078 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1079 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1080 } else {
1081 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1082 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1083 }
1084 }
1085 }
1086 }
1087 read_unlock(&fib6_walker_lock);
1088
1089 node_free(fn);
7fc33165 1090 if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn))
1da177e4
LT
1091 return pn;
1092
1093 rt6_release(pn->leaf);
1094 pn->leaf = NULL;
1095 fn = pn;
1096 }
1097}
1098
1099static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
86872cb5 1100 struct nl_info *info)
1da177e4
LT
1101{
1102 struct fib6_walker_t *w;
1103 struct rt6_info *rt = *rtp;
1104
1105 RT6_TRACE("fib6_del_route\n");
1106
1107 /* Unlink it */
1108 *rtp = rt->u.next;
1109 rt->rt6i_node = NULL;
1110 rt6_stats.fib_rt_entries--;
1111 rt6_stats.fib_discarded_routes++;
1112
1113 /* Adjust walkers */
1114 read_lock(&fib6_walker_lock);
1115 FOR_WALKERS(w) {
1116 if (w->state == FWS_C && w->leaf == rt) {
1117 RT6_TRACE("walker %p adjusted by delroute\n", w);
1118 w->leaf = rt->u.next;
1119 if (w->leaf == NULL)
1120 w->state = FWS_U;
1121 }
1122 }
1123 read_unlock(&fib6_walker_lock);
1124
1125 rt->u.next = NULL;
1126
1127 if (fn->leaf == NULL && fn->fn_flags&RTN_TL_ROOT)
1128 fn->leaf = &ip6_null_entry;
1129
1130 /* If it was last route, expunge its radix tree node */
1131 if (fn->leaf == NULL) {
1132 fn->fn_flags &= ~RTN_RTINFO;
1133 rt6_stats.fib_route_nodes--;
1134 fn = fib6_repair_tree(fn);
1135 }
1136
1137 if (atomic_read(&rt->rt6i_ref) != 1) {
1138 /* This route is used as dummy address holder in some split
1139 * nodes. It is not leaked, but it still holds other resources,
1140 * which must be released in time. So, scan ascendant nodes
1141 * and replace dummy references to this route with references
1142 * to still alive ones.
1143 */
1144 while (fn) {
1145 if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
1146 fn->leaf = fib6_find_prefix(fn);
1147 atomic_inc(&fn->leaf->rt6i_ref);
1148 rt6_release(rt);
1149 }
1150 fn = fn->parent;
1151 }
1152 /* No more references are possible at this point. */
1153 if (atomic_read(&rt->rt6i_ref) != 1) BUG();
1154 }
1155
86872cb5 1156 inet6_rt_notify(RTM_DELROUTE, rt, info);
1da177e4
LT
1157 rt6_release(rt);
1158}
1159
86872cb5 1160int fib6_del(struct rt6_info *rt, struct nl_info *info)
1da177e4
LT
1161{
1162 struct fib6_node *fn = rt->rt6i_node;
1163 struct rt6_info **rtp;
1164
1165#if RT6_DEBUG >= 2
1166 if (rt->u.dst.obsolete>0) {
1167 BUG_TRAP(fn==NULL);
1168 return -ENOENT;
1169 }
1170#endif
1171 if (fn == NULL || rt == &ip6_null_entry)
1172 return -ENOENT;
1173
1174 BUG_TRAP(fn->fn_flags&RTN_RTINFO);
1175
150730d5
YH
1176 if (!(rt->rt6i_flags&RTF_CACHE)) {
1177 struct fib6_node *pn = fn;
1178#ifdef CONFIG_IPV6_SUBTREES
1179 /* clones of this route might be in another subtree */
1180 if (rt->rt6i_src.plen) {
1181 while (!(pn->fn_flags&RTN_ROOT))
1182 pn = pn->parent;
1183 pn = pn->parent;
1184 }
1185#endif
1186 fib6_prune_clones(pn, rt);
1187 }
1da177e4
LT
1188
1189 /*
1190 * Walk the leaf entries looking for ourself
1191 */
1192
1193 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.next) {
1194 if (*rtp == rt) {
86872cb5 1195 fib6_del_route(fn, rtp, info);
1da177e4
LT
1196 return 0;
1197 }
1198 }
1199 return -ENOENT;
1200}
1201
1202/*
1203 * Tree traversal function.
1204 *
1205 * Certainly, it is not interrupt safe.
1206 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1207 * It means, that we can modify tree during walking
1208 * and use this function for garbage collection, clone pruning,
1209 * cleaning tree when a device goes down etc. etc.
1210 *
1211 * It guarantees that every node will be traversed,
1212 * and that it will be traversed only once.
1213 *
1214 * Callback function w->func may return:
1215 * 0 -> continue walking.
1216 * positive value -> walking is suspended (used by tree dumps,
1217 * and probably by gc, if it will be split to several slices)
1218 * negative value -> terminate walking.
1219 *
1220 * The function itself returns:
1221 * 0 -> walk is complete.
1222 * >0 -> walk is incomplete (i.e. suspended)
1223 * <0 -> walk is terminated by an error.
1224 */
1225
90d41122 1226static int fib6_walk_continue(struct fib6_walker_t *w)
1da177e4
LT
1227{
1228 struct fib6_node *fn, *pn;
1229
1230 for (;;) {
1231 fn = w->node;
1232 if (fn == NULL)
1233 return 0;
1234
1235 if (w->prune && fn != w->root &&
1236 fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1237 w->state = FWS_C;
1238 w->leaf = fn->leaf;
1239 }
1240 switch (w->state) {
1241#ifdef CONFIG_IPV6_SUBTREES
1242 case FWS_S:
7fc33165
YH
1243 if (FIB6_SUBTREE(fn)) {
1244 w->node = FIB6_SUBTREE(fn);
1da177e4
LT
1245 continue;
1246 }
1247 w->state = FWS_L;
1248#endif
1249 case FWS_L:
1250 if (fn->left) {
1251 w->node = fn->left;
1252 w->state = FWS_INIT;
1253 continue;
1254 }
1255 w->state = FWS_R;
1256 case FWS_R:
1257 if (fn->right) {
1258 w->node = fn->right;
1259 w->state = FWS_INIT;
1260 continue;
1261 }
1262 w->state = FWS_C;
1263 w->leaf = fn->leaf;
1264 case FWS_C:
1265 if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1266 int err = w->func(w);
1267 if (err)
1268 return err;
1269 continue;
1270 }
1271 w->state = FWS_U;
1272 case FWS_U:
1273 if (fn == w->root)
1274 return 0;
1275 pn = fn->parent;
1276 w->node = pn;
1277#ifdef CONFIG_IPV6_SUBTREES
7fc33165 1278 if (FIB6_SUBTREE(pn) == fn) {
1da177e4
LT
1279 BUG_TRAP(fn->fn_flags&RTN_ROOT);
1280 w->state = FWS_L;
1281 continue;
1282 }
1283#endif
1284 if (pn->left == fn) {
1285 w->state = FWS_R;
1286 continue;
1287 }
1288 if (pn->right == fn) {
1289 w->state = FWS_C;
1290 w->leaf = w->node->leaf;
1291 continue;
1292 }
1293#if RT6_DEBUG >= 2
1294 BUG_TRAP(0);
1295#endif
1296 }
1297 }
1298}
1299
90d41122 1300static int fib6_walk(struct fib6_walker_t *w)
1da177e4
LT
1301{
1302 int res;
1303
1304 w->state = FWS_INIT;
1305 w->node = w->root;
1306
1307 fib6_walker_link(w);
1308 res = fib6_walk_continue(w);
1309 if (res <= 0)
1310 fib6_walker_unlink(w);
1311 return res;
1312}
1313
1314static int fib6_clean_node(struct fib6_walker_t *w)
1315{
1316 int res;
1317 struct rt6_info *rt;
1318 struct fib6_cleaner_t *c = (struct fib6_cleaner_t*)w;
1319
1320 for (rt = w->leaf; rt; rt = rt->u.next) {
1321 res = c->func(rt, c->arg);
1322 if (res < 0) {
1323 w->leaf = rt;
86872cb5 1324 res = fib6_del(rt, NULL);
1da177e4
LT
1325 if (res) {
1326#if RT6_DEBUG >= 2
1327 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1328#endif
1329 continue;
1330 }
1331 return 0;
1332 }
1333 BUG_TRAP(res==0);
1334 }
1335 w->leaf = rt;
1336 return 0;
1337}
1338
1339/*
1340 * Convenient frontend to tree walker.
1341 *
1342 * func is called on each route.
1343 * It may return -1 -> delete this route.
1344 * 0 -> continue walking
1345 *
1346 * prune==1 -> only immediate children of node (certainly,
1347 * ignoring pure split nodes) will be scanned.
1348 */
1349
8ce11e6a
AB
1350static void fib6_clean_tree(struct fib6_node *root,
1351 int (*func)(struct rt6_info *, void *arg),
1352 int prune, void *arg)
1da177e4
LT
1353{
1354 struct fib6_cleaner_t c;
1355
1356 c.w.root = root;
1357 c.w.func = fib6_clean_node;
1358 c.w.prune = prune;
1359 c.func = func;
1360 c.arg = arg;
1361
1362 fib6_walk(&c.w);
1363}
1364
c71099ac
TG
1365void fib6_clean_all(int (*func)(struct rt6_info *, void *arg),
1366 int prune, void *arg)
1367{
c71099ac 1368 struct fib6_table *table;
1b43af54
PM
1369 struct hlist_node *node;
1370 unsigned int h;
c71099ac 1371
1b43af54
PM
1372 rcu_read_lock();
1373 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
1374 hlist_for_each_entry_rcu(table, node, &fib_table_hash[h],
1375 tb6_hlist) {
c71099ac
TG
1376 write_lock_bh(&table->tb6_lock);
1377 fib6_clean_tree(&table->tb6_root, func, prune, arg);
1378 write_unlock_bh(&table->tb6_lock);
1379 }
1380 }
1b43af54 1381 rcu_read_unlock();
c71099ac
TG
1382}
1383
1da177e4
LT
1384static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1385{
1386 if (rt->rt6i_flags & RTF_CACHE) {
1387 RT6_TRACE("pruning clone %p\n", rt);
1388 return -1;
1389 }
1390
1391 return 0;
1392}
1393
1394static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt)
1395{
1396 fib6_clean_tree(fn, fib6_prune_clone, 1, rt);
1397}
1398
1399/*
1400 * Garbage collection
1401 */
1402
1403static struct fib6_gc_args
1404{
1405 int timeout;
1406 int more;
1407} gc_args;
1408
1409static int fib6_age(struct rt6_info *rt, void *arg)
1410{
1411 unsigned long now = jiffies;
1412
1413 /*
1414 * check addrconf expiration here.
1415 * Routes are expired even if they are in use.
1416 *
1417 * Also age clones. Note, that clones are aged out
1418 * only if they are not in use now.
1419 */
1420
1421 if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1422 if (time_after(now, rt->rt6i_expires)) {
1423 RT6_TRACE("expiring %p\n", rt);
1da177e4
LT
1424 return -1;
1425 }
1426 gc_args.more++;
1427 } else if (rt->rt6i_flags & RTF_CACHE) {
1428 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1429 time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1430 RT6_TRACE("aging clone %p\n", rt);
1431 return -1;
1432 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1433 (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1434 RT6_TRACE("purging route %p via non-router but gateway\n",
1435 rt);
1436 return -1;
1437 }
1438 gc_args.more++;
1439 }
1440
1441 return 0;
1442}
1443
1444static DEFINE_SPINLOCK(fib6_gc_lock);
1445
1446void fib6_run_gc(unsigned long dummy)
1447{
1448 if (dummy != ~0UL) {
1449 spin_lock_bh(&fib6_gc_lock);
1450 gc_args.timeout = dummy ? (int)dummy : ip6_rt_gc_interval;
1451 } else {
1452 local_bh_disable();
1453 if (!spin_trylock(&fib6_gc_lock)) {
1454 mod_timer(&ip6_fib_timer, jiffies + HZ);
1455 local_bh_enable();
1456 return;
1457 }
1458 gc_args.timeout = ip6_rt_gc_interval;
1459 }
1460 gc_args.more = 0;
1461
1da177e4 1462 ndisc_dst_gc(&gc_args.more);
c71099ac 1463 fib6_clean_all(fib6_age, 0, NULL);
1da177e4
LT
1464
1465 if (gc_args.more)
1466 mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval);
1467 else {
1468 del_timer(&ip6_fib_timer);
1469 ip6_fib_timer.expires = 0;
1470 }
1471 spin_unlock_bh(&fib6_gc_lock);
1472}
1473
1474void __init fib6_init(void)
1475{
1476 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1477 sizeof(struct fib6_node),
e5d679f3 1478 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
1da177e4 1479 NULL, NULL);
c71099ac
TG
1480
1481 fib6_tables_init();
1da177e4
LT
1482}
1483
1484void fib6_gc_cleanup(void)
1485{
1486 del_timer(&ip6_fib_timer);
1487 kmem_cache_destroy(fib6_node_kmem);
1488}