2 * Routing Table functions.
3 * Copyright (C) 1998 Kunihiro Ishiguro
5 * This file is part of GNU Zebra.
7 * GNU Zebra is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2, or (at your option) any
12 * GNU Zebra is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Zebra; see the file COPYING. If not, write to the Free
19 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
28 #include "sockunion.h"
30 DEFINE_MTYPE( LIB
, ROUTE_TABLE
, "Route table")
31 DEFINE_MTYPE_STATIC(LIB
, ROUTE_NODE
, "Route node")
33 static void route_node_delete (struct route_node
*);
34 static void route_table_free (struct route_table
*);
38 * route_table_init_with_delegate
41 route_table_init_with_delegate (route_table_delegate_t
*delegate
)
43 struct route_table
*rt
;
45 rt
= XCALLOC (MTYPE_ROUTE_TABLE
, sizeof (struct route_table
));
46 rt
->delegate
= delegate
;
51 route_table_finish (struct route_table
*rt
)
53 route_table_free (rt
);
56 /* Allocate new route node. */
57 static struct route_node
*
58 route_node_new (struct route_table
*table
)
60 return table
->delegate
->create_node (table
->delegate
, table
);
63 /* Allocate new route node with prefix set. */
64 static struct route_node
*
65 route_node_set (struct route_table
*table
, const struct prefix
*prefix
)
67 struct route_node
*node
;
69 node
= route_node_new (table
);
71 prefix_copy (&node
->p
, prefix
);
77 /* Free route node. */
79 route_node_free (struct route_table
*table
, struct route_node
*node
)
81 table
->delegate
->destroy_node (table
->delegate
, table
, node
);
84 /* Free route table. */
86 route_table_free (struct route_table
*rt
)
88 struct route_node
*tmp_node
;
89 struct route_node
*node
;
96 /* Bulk deletion of nodes remaining in this table. This function is not
97 called until workers have completed their dependency on this table.
98 A final route_unlock_node() will not be called for these nodes. */
109 node
= node
->l_right
;
116 tmp_node
->table
->count
--;
117 tmp_node
->lock
= 0; /* to cause assert if unlocked after this */
118 route_node_free (rt
, tmp_node
);
122 if (node
->l_left
== tmp_node
)
125 node
->l_right
= NULL
;
133 assert (rt
->count
== 0);
135 XFREE (MTYPE_ROUTE_TABLE
, rt
);
139 /* Utility mask array. */
140 static const u_char maskbit
[] =
142 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff
145 /* Common prefix route genaration. */
147 route_common (const struct prefix
*n
, const struct prefix
*p
, struct prefix
*new)
153 const u_char
*np
= (const u_char
*)&n
->u
.prefix
;
154 const u_char
*pp
= (const u_char
*)&p
->u
.prefix
;
155 u_char
*newp
= (u_char
*)&new->u
.prefix
;
157 for (i
= 0; i
< p
->prefixlen
/ 8; i
++)
165 new->prefixlen
= i
* 8;
167 if (new->prefixlen
!= p
->prefixlen
)
169 diff
= np
[i
] ^ pp
[i
];
171 while (new->prefixlen
< p
->prefixlen
&& !(mask
& diff
))
176 newp
[i
] = np
[i
] & maskbit
[new->prefixlen
% 8];
181 set_link (struct route_node
*node
, struct route_node
*new)
183 unsigned int bit
= prefix_bit (&new->p
.u
.prefix
, node
->p
.prefixlen
);
185 node
->link
[bit
] = new;
191 route_lock_node (struct route_node
*node
)
199 route_unlock_node (struct route_node
*node
)
201 assert (node
->lock
> 0);
205 route_node_delete (node
);
208 /* Find matched prefix. */
210 route_node_match (const struct route_table
*table
, const struct prefix
*p
)
212 struct route_node
*node
;
213 struct route_node
*matched
;
218 /* Walk down tree. If there is matched route then store it to
220 while (node
&& node
->p
.prefixlen
<= p
->prefixlen
&&
221 prefix_match (&node
->p
, p
))
226 if (node
->p
.prefixlen
== p
->prefixlen
)
229 node
= node
->link
[prefix_bit(&p
->u
.prefix
, node
->p
.prefixlen
)];
232 /* If matched route found, return it. */
234 return route_lock_node (matched
);
240 route_node_match_ipv4 (const struct route_table
*table
,
241 const struct in_addr
*addr
)
243 struct prefix_ipv4 p
;
245 memset (&p
, 0, sizeof (struct prefix_ipv4
));
247 p
.prefixlen
= IPV4_MAX_PREFIXLEN
;
250 return route_node_match (table
, (struct prefix
*) &p
);
254 route_node_match_ipv6 (const struct route_table
*table
,
255 const struct in6_addr
*addr
)
257 struct prefix_ipv6 p
;
259 memset (&p
, 0, sizeof (struct prefix_ipv6
));
261 p
.prefixlen
= IPV6_MAX_PREFIXLEN
;
264 return route_node_match (table
, (struct prefix
*) &p
);
267 /* Lookup same prefix node. Return NULL when we can't find route. */
269 route_node_lookup (const struct route_table
*table
, const struct prefix
*p
)
271 struct route_node
*node
;
272 u_char prefixlen
= p
->prefixlen
;
273 const u_char
*prefix
= &p
->u
.prefix
;
277 while (node
&& node
->p
.prefixlen
<= prefixlen
&&
278 prefix_match (&node
->p
, p
))
280 if (node
->p
.prefixlen
== prefixlen
)
281 return node
->info
? route_lock_node (node
) : NULL
;
283 node
= node
->link
[prefix_bit(prefix
, node
->p
.prefixlen
)];
289 /* Add node to routing table. */
291 route_node_get (struct route_table
*const table
, const struct prefix
*p
)
293 struct route_node
*new;
294 struct route_node
*node
;
295 struct route_node
*match
;
296 u_char prefixlen
= p
->prefixlen
;
297 const u_char
*prefix
= &p
->u
.prefix
;
301 while (node
&& node
->p
.prefixlen
<= prefixlen
&&
302 prefix_match (&node
->p
, p
))
304 if (node
->p
.prefixlen
== prefixlen
)
305 return route_lock_node (node
);
308 node
= node
->link
[prefix_bit(prefix
, node
->p
.prefixlen
)];
313 new = route_node_set (table
, p
);
315 set_link (match
, new);
321 new = route_node_new (table
);
322 route_common (&node
->p
, p
, &new->p
);
323 new->p
.family
= p
->family
;
325 set_link (new, node
);
328 set_link (match
, new);
332 if (new->p
.prefixlen
!= p
->prefixlen
)
335 new = route_node_set (table
, p
);
336 set_link (match
, new);
341 route_lock_node (new);
346 /* Delete node from the routing table. */
348 route_node_delete (struct route_node
*node
)
350 struct route_node
*child
;
351 struct route_node
*parent
;
353 assert (node
->lock
== 0);
354 assert (node
->info
== NULL
);
356 if (node
->l_left
&& node
->l_right
)
360 child
= node
->l_left
;
362 child
= node
->l_right
;
364 parent
= node
->parent
;
367 child
->parent
= parent
;
371 if (parent
->l_left
== node
)
372 parent
->l_left
= child
;
374 parent
->l_right
= child
;
377 node
->table
->top
= child
;
379 node
->table
->count
--;
381 route_node_free (node
->table
, node
);
383 /* If parent node is stub then delete it also. */
384 if (parent
&& parent
->lock
== 0)
385 route_node_delete (parent
);
388 /* Get fist node and lock it. This function is useful when one want
389 to lookup all the node exist in the routing table. */
391 route_top (struct route_table
*table
)
393 /* If there is no node in the routing table return NULL. */
394 if (table
->top
== NULL
)
397 /* Lock the top node and return it. */
398 route_lock_node (table
->top
);
402 /* Unlock current node and lock next node then return it. */
404 route_next (struct route_node
*node
)
406 struct route_node
*next
;
407 struct route_node
*start
;
409 /* Node may be deleted from route_unlock_node so we have to preserve
410 next node's pointer. */
415 route_lock_node (next
);
416 route_unlock_node (node
);
421 next
= node
->l_right
;
422 route_lock_node (next
);
423 route_unlock_node (node
);
430 if (node
->parent
->l_left
== node
&& node
->parent
->l_right
)
432 next
= node
->parent
->l_right
;
433 route_lock_node (next
);
434 route_unlock_node (start
);
439 route_unlock_node (start
);
443 /* Unlock current node and lock next node until limit. */
445 route_next_until (struct route_node
*node
, struct route_node
*limit
)
447 struct route_node
*next
;
448 struct route_node
*start
;
450 /* Node may be deleted from route_unlock_node so we have to preserve
451 next node's pointer. */
456 route_lock_node (next
);
457 route_unlock_node (node
);
462 next
= node
->l_right
;
463 route_lock_node (next
);
464 route_unlock_node (node
);
469 while (node
->parent
&& node
!= limit
)
471 if (node
->parent
->l_left
== node
&& node
->parent
->l_right
)
473 next
= node
->parent
->l_right
;
474 route_lock_node (next
);
475 route_unlock_node (start
);
480 route_unlock_node (start
);
485 route_table_count (const struct route_table
*table
)
493 * Default function for creating a route node.
496 route_node_create (route_table_delegate_t
*delegate
,
497 struct route_table
*table
)
499 struct route_node
*node
;
500 node
= XCALLOC (MTYPE_ROUTE_NODE
, sizeof (struct route_node
));
507 * Default function for destroying a route node.
510 route_node_destroy (route_table_delegate_t
*delegate
,
511 struct route_table
*table
, struct route_node
*node
)
513 XFREE (MTYPE_ROUTE_NODE
, node
);
519 static route_table_delegate_t default_delegate
= {
520 .create_node
= route_node_create
,
521 .destroy_node
= route_node_destroy
524 route_table_delegate_t
*
525 route_table_get_default_delegate(void)
527 return &default_delegate
;
534 route_table_init (void)
536 return route_table_init_with_delegate (&default_delegate
);
540 * route_table_prefix_iter_cmp
542 * Compare two prefixes according to the order in which they appear in
543 * an iteration over a tree.
545 * @return -1 if p1 occurs before p2 (p1 < p2)
546 * 0 if the prefixes are identical (p1 == p2)
547 * +1 if p1 occurs after p2 (p1 > p2)
550 route_table_prefix_iter_cmp (struct prefix
*p1
, struct prefix
*p2
)
552 struct prefix common_space
;
553 struct prefix
*common
= &common_space
;
555 if (p1
->prefixlen
<= p2
->prefixlen
)
557 if (prefix_match (p1
, p2
))
561 * p1 contains p2, or is equal to it.
563 return (p1
->prefixlen
== p2
->prefixlen
) ? 0 : -1;
570 * Check if p2 contains p1.
572 if (prefix_match (p2
, p1
))
576 route_common (p1
, p2
, common
);
577 assert (common
->prefixlen
< p1
->prefixlen
);
578 assert (common
->prefixlen
< p2
->prefixlen
);
581 * Both prefixes are longer than the common prefix.
583 * We need to check the bit after the common prefixlen to determine
584 * which one comes later.
586 if (prefix_bit (&p1
->u
.prefix
, common
->prefixlen
))
590 * We branch to the right to get to p1 from the common prefix.
592 assert (!prefix_bit (&p2
->u
.prefix
, common
->prefixlen
));
597 * We branch to the right to get to p2 from the common prefix.
599 assert (prefix_bit (&p2
->u
.prefix
, common
->prefixlen
));
604 * route_get_subtree_next
606 * Helper function that returns the first node that follows the nodes
607 * in the sub-tree under 'node' in iteration order.
609 static struct route_node
*
610 route_get_subtree_next (struct route_node
*node
)
614 if (node
->parent
->l_left
== node
&& node
->parent
->l_right
)
615 return node
->parent
->l_right
;
624 * route_table_get_next_internal
626 * Helper function to find the node that occurs after the given prefix in
627 * order of iteration.
629 * @see route_table_get_next
631 static struct route_node
*
632 route_table_get_next_internal (const struct route_table
*table
,
635 struct route_node
*node
, *tmp_node
;
644 if (node
->p
.prefixlen
< p
->prefixlen
)
645 match
= prefix_match (&node
->p
, p
);
647 match
= prefix_match (p
, &node
->p
);
651 if (node
->p
.prefixlen
== p
->prefixlen
)
655 * The prefix p exists in the tree, just return the next
658 route_lock_node (node
);
659 node
= route_next (node
);
661 route_unlock_node (node
);
666 if (node
->p
.prefixlen
> p
->prefixlen
)
670 * Node is in the subtree of p, and hence greater than p.
676 * p is in the sub-tree under node.
678 tmp_node
= node
->link
[prefix_bit (&p
->u
.prefix
, node
->p
.prefixlen
)];
687 * There are no nodes in the direction where p should be. If
688 * node has a right child, then it must be greater than p.
691 return node
->l_right
;
694 * No more children to follow, go upwards looking for the next
697 return route_get_subtree_next (node
);
701 * Neither node prefix nor 'p' contains the other.
703 cmp
= route_table_prefix_iter_cmp (&node
->p
, p
);
708 * Node follows p in iteration order. Return it.
716 * Node and the subtree under it come before prefix p in
717 * iteration order. Prefix p and its sub-tree are not present in
718 * the tree. Go upwards and find the first node that follows the
719 * subtree. That node will also succeed p.
721 return route_get_subtree_next (node
);
728 * route_table_get_next
730 * Find the node that occurs after the given prefix in order of
734 route_table_get_next (const struct route_table
*table
, struct prefix
*p
)
736 struct route_node
*node
;
738 node
= route_table_get_next_internal (table
, p
);
741 assert (route_table_prefix_iter_cmp (&node
->p
, p
) > 0);
742 route_lock_node (node
);
748 * route_table_iter_init
751 route_table_iter_init (route_table_iter_t
* iter
, struct route_table
*table
)
753 memset (iter
, 0, sizeof (*iter
));
754 iter
->state
= RT_ITER_STATE_INIT
;
759 * route_table_iter_pause
761 * Pause an iteration over the table. This allows the iteration to be
762 * resumed point after arbitrary additions/deletions from the table.
763 * An iteration can be resumed by just calling route_table_iter_next()
767 route_table_iter_pause (route_table_iter_t
* iter
)
772 case RT_ITER_STATE_INIT
:
773 case RT_ITER_STATE_PAUSED
:
774 case RT_ITER_STATE_DONE
:
777 case RT_ITER_STATE_ITERATING
:
780 * Save the prefix that we are currently at. The next call to
781 * route_table_iter_next() will return the node after this prefix
784 prefix_copy (&iter
->pause_prefix
, &iter
->current
->p
);
785 route_unlock_node (iter
->current
);
786 iter
->current
= NULL
;
787 iter
->state
= RT_ITER_STATE_PAUSED
;
797 * route_table_iter_cleanup
799 * Release any resources held by the iterator.
802 route_table_iter_cleanup (route_table_iter_t
* iter
)
804 if (iter
->state
== RT_ITER_STATE_ITERATING
)
806 route_unlock_node (iter
->current
);
807 iter
->current
= NULL
;
809 assert (!iter
->current
);
812 * Set the state to RT_ITER_STATE_DONE to make any
813 * route_table_iter_next() calls on this iterator return NULL.
815 iter
->state
= RT_ITER_STATE_DONE
;