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 along
18 * with this program; see the file COPYING; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 #define FRR_COMPILING_TABLE_C
29 #include "sockunion.h"
30 #include "libfrr_trace.h"
32 DEFINE_MTYPE_STATIC(LIB
, ROUTE_TABLE
, "Route table");
33 DEFINE_MTYPE(LIB
, ROUTE_NODE
, "Route node");
35 static void route_table_free(struct route_table
*);
37 static int route_table_hash_cmp(const struct route_node
*a
,
38 const struct route_node
*b
)
40 return prefix_cmp(&a
->p
, &b
->p
);
43 DECLARE_HASH(rn_hash_node
, struct route_node
, nodehash
, route_table_hash_cmp
,
46 * route_table_init_with_delegate
49 route_table_init_with_delegate(route_table_delegate_t
*delegate
)
51 struct route_table
*rt
;
53 rt
= XCALLOC(MTYPE_ROUTE_TABLE
, sizeof(struct route_table
));
54 rt
->delegate
= delegate
;
55 rn_hash_node_init(&rt
->hash
);
59 void route_table_finish(struct route_table
*rt
)
64 /* Allocate new route node. */
65 static struct route_node
*route_node_new(struct route_table
*table
)
67 return table
->delegate
->create_node(table
->delegate
, table
);
70 /* Allocate new route node with prefix set. */
71 static struct route_node
*route_node_set(struct route_table
*table
,
72 const struct prefix
*prefix
)
74 struct route_node
*node
;
76 node
= route_node_new(table
);
78 prefix_copy(&node
->p
, prefix
);
81 rn_hash_node_add(&node
->table
->hash
, node
);
86 /* Free route node. */
87 static void route_node_free(struct route_table
*table
, struct route_node
*node
)
90 table
->cleanup(table
, node
);
91 table
->delegate
->destroy_node(table
->delegate
, table
, node
);
94 /* Free route table. */
95 static void route_table_free(struct route_table
*rt
)
97 struct route_node
*tmp_node
;
98 struct route_node
*node
;
105 /* Bulk deletion of nodes remaining in this table. This function is not
106 called until workers have completed their dependency on this table.
107 A final route_unlock_node() will not be called for these nodes. */
115 node
= node
->l_right
;
122 tmp_node
->table
->count
--;
124 0; /* to cause assert if unlocked after this */
125 rn_hash_node_del(&rt
->hash
, tmp_node
);
126 route_node_free(rt
, tmp_node
);
129 if (node
->l_left
== tmp_node
)
132 node
->l_right
= NULL
;
138 assert(rt
->count
== 0);
140 rn_hash_node_fini(&rt
->hash
);
141 XFREE(MTYPE_ROUTE_TABLE
, rt
);
145 /* Utility mask array. */
146 static const uint8_t maskbit
[] = {0x00, 0x80, 0xc0, 0xe0, 0xf0,
147 0xf8, 0xfc, 0xfe, 0xff};
149 /* Common prefix route genaration. */
150 static void route_common(const struct prefix
*n
, const struct prefix
*p
,
160 if (n
->family
== AF_FLOWSPEC
)
161 return prefix_copy(new, p
);
162 np
= (const uint8_t *)&n
->u
.prefix
;
163 pp
= (const uint8_t *)&p
->u
.prefix
;
165 newp
= &new->u
.prefix
;
167 for (i
= 0; i
< p
->prefixlen
/ 8; i
++) {
174 new->prefixlen
= i
* 8;
176 if (new->prefixlen
!= p
->prefixlen
) {
177 diff
= np
[i
] ^ pp
[i
];
179 while (new->prefixlen
< p
->prefixlen
&& !(mask
& diff
)) {
183 newp
[i
] = np
[i
] & maskbit
[new->prefixlen
% 8];
187 static void set_link(struct route_node
*node
, struct route_node
*new)
189 unsigned int bit
= prefix_bit(&new->p
.u
.prefix
, node
->p
.prefixlen
);
191 node
->link
[bit
] = new;
195 /* Find matched prefix. */
196 struct route_node
*route_node_match(struct route_table
*table
,
197 union prefixconstptr pu
)
199 const struct prefix
*p
= pu
.p
;
200 struct route_node
*node
;
201 struct route_node
*matched
;
206 /* Walk down tree. If there is matched route then store it to
208 while (node
&& node
->p
.prefixlen
<= p
->prefixlen
209 && prefix_match(&node
->p
, p
)) {
213 if (node
->p
.prefixlen
== p
->prefixlen
)
216 node
= node
->link
[prefix_bit(&p
->u
.prefix
, node
->p
.prefixlen
)];
219 /* If matched route found, return it. */
221 return route_lock_node(matched
);
226 struct route_node
*route_node_match_ipv4(struct route_table
*table
,
227 const struct in_addr
*addr
)
229 struct prefix_ipv4 p
;
231 memset(&p
, 0, sizeof(p
));
233 p
.prefixlen
= IPV4_MAX_BITLEN
;
236 return route_node_match(table
, (struct prefix
*)&p
);
239 struct route_node
*route_node_match_ipv6(struct route_table
*table
,
240 const struct in6_addr
*addr
)
242 struct prefix_ipv6 p
;
244 memset(&p
, 0, sizeof(p
));
246 p
.prefixlen
= IPV6_MAX_BITLEN
;
249 return route_node_match(table
, &p
);
252 /* Lookup same prefix node. Return NULL when we can't find route. */
253 struct route_node
*route_node_lookup(struct route_table
*table
,
254 union prefixconstptr pu
)
256 struct route_node rn
, *node
;
257 prefix_copy(&rn
.p
, pu
.p
);
260 node
= rn_hash_node_find(&table
->hash
, &rn
);
261 return (node
&& node
->info
) ? route_lock_node(node
) : NULL
;
264 /* Lookup same prefix node. Return NULL when we can't find route. */
265 struct route_node
*route_node_lookup_maynull(struct route_table
*table
,
266 union prefixconstptr pu
)
268 struct route_node rn
, *node
;
269 prefix_copy(&rn
.p
, pu
.p
);
272 node
= rn_hash_node_find(&table
->hash
, &rn
);
273 return node
? route_lock_node(node
) : NULL
;
276 /* Add node to routing table. */
277 struct route_node
*route_node_get(struct route_table
*table
,
278 union prefixconstptr pu
)
280 if (frrtrace_enabled(frr_libfrr
, route_node_get
)) {
281 char buf
[PREFIX2STR_BUFFER
];
282 prefix2str(pu
, buf
, sizeof(buf
));
283 frrtrace(2, frr_libfrr
, route_node_get
, table
, buf
);
286 struct route_node search
;
287 struct prefix
*p
= &search
.p
;
289 prefix_copy(p
, pu
.p
);
292 struct route_node
*new;
293 struct route_node
*node
;
294 struct route_node
*match
;
295 uint16_t prefixlen
= p
->prefixlen
;
296 const uint8_t *prefix
= &p
->u
.prefix
;
298 node
= rn_hash_node_find(&table
->hash
, &search
);
299 if (node
&& node
->info
)
300 return route_lock_node(node
);
304 while (node
&& node
->p
.prefixlen
<= prefixlen
305 && prefix_match(&node
->p
, p
)) {
306 if (node
->p
.prefixlen
== prefixlen
)
307 return route_lock_node(node
);
310 node
= node
->link
[prefix_bit(prefix
, node
->p
.prefixlen
)];
314 new = route_node_set(table
, p
);
316 set_link(match
, new);
320 new = route_node_new(table
);
321 route_common(&node
->p
, p
, &new->p
);
322 new->p
.family
= p
->family
;
325 rn_hash_node_add(&table
->hash
, new);
328 set_link(match
, new);
332 if (new->p
.prefixlen
!= p
->prefixlen
) {
334 new = route_node_set(table
, p
);
335 set_link(match
, new);
340 route_lock_node(new);
345 /* Delete node from the routing table. */
346 void route_node_delete(struct route_node
*node
)
348 struct route_node
*child
;
349 struct route_node
*parent
;
351 assert(node
->lock
== 0);
352 assert(node
->info
== NULL
);
354 if (node
->l_left
&& node
->l_right
)
358 child
= node
->l_left
;
360 child
= node
->l_right
;
362 parent
= node
->parent
;
365 child
->parent
= parent
;
368 if (parent
->l_left
== node
)
369 parent
->l_left
= child
;
371 parent
->l_right
= child
;
373 node
->table
->top
= child
;
375 node
->table
->count
--;
377 rn_hash_node_del(&node
->table
->hash
, node
);
379 /* WARNING: FRAGILE CODE!
380 * route_node_free may have the side effect of free'ing the entire
382 * this is permitted only if table->count got decremented to zero above,
383 * because in that case parent will also be NULL, so that we won't try
385 * delete a now-stale parent below.
387 * cf. srcdest_srcnode_destroy() in zebra/zebra_rib.c */
389 route_node_free(node
->table
, node
);
391 /* If parent node is stub then delete it also. */
392 if (parent
&& parent
->lock
== 0)
393 route_node_delete(parent
);
396 /* Get first node and lock it. This function is useful when one wants
397 to lookup all the node exist in the routing table. */
398 struct route_node
*route_top(struct route_table
*table
)
400 /* If there is no node in the routing table return NULL. */
401 if (table
->top
== NULL
)
404 /* Lock the top node and return it. */
405 route_lock_node(table
->top
);
409 /* Unlock current node and lock next node then return it. */
410 struct route_node
*route_next(struct route_node
*node
)
412 struct route_node
*next
;
413 struct route_node
*start
;
415 /* Node may be deleted from route_unlock_node so we have to preserve
416 next node's pointer. */
420 route_lock_node(next
);
421 route_unlock_node(node
);
425 next
= node
->l_right
;
426 route_lock_node(next
);
427 route_unlock_node(node
);
432 while (node
->parent
) {
433 if (node
->parent
->l_left
== node
&& node
->parent
->l_right
) {
434 next
= node
->parent
->l_right
;
435 route_lock_node(next
);
436 route_unlock_node(start
);
441 route_unlock_node(start
);
445 /* Unlock current node and lock next node until limit. */
446 struct route_node
*route_next_until(struct route_node
*node
,
447 const struct route_node
*limit
)
449 struct route_node
*next
;
450 struct route_node
*start
;
452 /* Node may be deleted from route_unlock_node so we have to preserve
453 next node's pointer. */
457 route_lock_node(next
);
458 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
) {
470 if (node
->parent
->l_left
== node
&& node
->parent
->l_right
) {
471 next
= node
->parent
->l_right
;
472 route_lock_node(next
);
473 route_unlock_node(start
);
478 route_unlock_node(start
);
482 unsigned long route_table_count(struct route_table
*table
)
490 * Default function for creating a route node.
492 struct route_node
*route_node_create(route_table_delegate_t
*delegate
,
493 struct route_table
*table
)
495 struct route_node
*node
;
496 node
= XCALLOC(MTYPE_ROUTE_NODE
, sizeof(struct route_node
));
503 * Default function for destroying a route node.
505 void route_node_destroy(route_table_delegate_t
*delegate
,
506 struct route_table
*table
, struct route_node
*node
)
508 XFREE(MTYPE_ROUTE_NODE
, node
);
514 static route_table_delegate_t default_delegate
= {
515 .create_node
= route_node_create
,
516 .destroy_node
= route_node_destroy
};
518 route_table_delegate_t
*route_table_get_default_delegate(void)
520 return &default_delegate
;
526 struct route_table
*route_table_init(void)
528 return route_table_init_with_delegate(&default_delegate
);
532 * route_table_prefix_iter_cmp
534 * Compare two prefixes according to the order in which they appear in
535 * an iteration over a tree.
537 * @return -1 if p1 occurs before p2 (p1 < p2)
538 * 0 if the prefixes are identical (p1 == p2)
539 * +1 if p1 occurs after p2 (p1 > p2)
541 int route_table_prefix_iter_cmp(const struct prefix
*p1
,
542 const struct prefix
*p2
)
544 struct prefix common_space
;
545 struct prefix
*common
= &common_space
;
547 if (p1
->prefixlen
<= p2
->prefixlen
) {
548 if (prefix_match(p1
, p2
)) {
551 * p1 contains p2, or is equal to it.
553 return (p1
->prefixlen
== p2
->prefixlen
) ? 0 : -1;
558 * Check if p2 contains p1.
560 if (prefix_match(p2
, p1
))
564 route_common(p1
, p2
, common
);
565 assert(common
->prefixlen
< p1
->prefixlen
);
566 assert(common
->prefixlen
< p2
->prefixlen
);
569 * Both prefixes are longer than the common prefix.
571 * We need to check the bit after the common prefixlen to determine
572 * which one comes later.
574 if (prefix_bit(&p1
->u
.prefix
, common
->prefixlen
)) {
577 * We branch to the right to get to p1 from the common prefix.
579 assert(!prefix_bit(&p2
->u
.prefix
, common
->prefixlen
));
584 * We branch to the right to get to p2 from the common prefix.
586 assert(prefix_bit(&p2
->u
.prefix
, common
->prefixlen
));
591 * route_get_subtree_next
593 * Helper function that returns the first node that follows the nodes
594 * in the sub-tree under 'node' in iteration order.
596 static struct route_node
*route_get_subtree_next(struct route_node
*node
)
598 while (node
->parent
) {
599 if (node
->parent
->l_left
== node
&& node
->parent
->l_right
)
600 return node
->parent
->l_right
;
609 * route_table_get_next_internal
611 * Helper function to find the node that occurs after the given prefix in
612 * order of iteration.
614 * @see route_table_get_next
616 static struct route_node
*
617 route_table_get_next_internal(struct route_table
*table
,
618 const struct prefix
*p
)
620 struct route_node
*node
, *tmp_node
;
628 if (node
->p
.prefixlen
< p
->prefixlen
)
629 match
= prefix_match(&node
->p
, p
);
631 match
= prefix_match(p
, &node
->p
);
634 if (node
->p
.prefixlen
== p
->prefixlen
) {
637 * The prefix p exists in the tree, just return
641 route_lock_node(node
);
642 node
= route_next(node
);
644 route_unlock_node(node
);
649 if (node
->p
.prefixlen
> p
->prefixlen
) {
652 * Node is in the subtree of p, and hence
659 * p is in the sub-tree under node.
661 tmp_node
= node
->link
[prefix_bit(&p
->u
.prefix
,
670 * There are no nodes in the direction where p should
672 * node has a right child, then it must be greater than
676 return node
->l_right
;
679 * No more children to follow, go upwards looking for
683 return route_get_subtree_next(node
);
687 * Neither node prefix nor 'p' contains the other.
689 cmp
= route_table_prefix_iter_cmp(&node
->p
, p
);
693 * Node follows p in iteration order. Return it.
701 * Node and the subtree under it come before prefix p in
702 * iteration order. Prefix p and its sub-tree are not present in
703 * the tree. Go upwards and find the first node that follows the
704 * subtree. That node will also succeed p.
706 return route_get_subtree_next(node
);
713 * route_table_get_next
715 * Find the node that occurs after the given prefix in order of
718 struct route_node
*route_table_get_next(struct route_table
*table
,
719 union prefixconstptr pu
)
721 const struct prefix
*p
= pu
.p
;
722 struct route_node
*node
;
724 node
= route_table_get_next_internal(table
, p
);
726 assert(route_table_prefix_iter_cmp(&node
->p
, p
) > 0);
727 route_lock_node(node
);
733 * route_table_iter_init
735 void route_table_iter_init(route_table_iter_t
*iter
, struct route_table
*table
)
737 memset(iter
, 0, sizeof(*iter
));
738 iter
->state
= RT_ITER_STATE_INIT
;
743 * route_table_iter_pause
745 * Pause an iteration over the table. This allows the iteration to be
746 * resumed point after arbitrary additions/deletions from the table.
747 * An iteration can be resumed by just calling route_table_iter_next()
750 void route_table_iter_pause(route_table_iter_t
*iter
)
752 switch (iter
->state
) {
754 case RT_ITER_STATE_INIT
:
755 case RT_ITER_STATE_PAUSED
:
756 case RT_ITER_STATE_DONE
:
759 case RT_ITER_STATE_ITERATING
:
762 * Save the prefix that we are currently at. The next call to
763 * route_table_iter_next() will return the node after this
767 prefix_copy(&iter
->pause_prefix
, &iter
->current
->p
);
768 route_unlock_node(iter
->current
);
769 iter
->current
= NULL
;
770 iter
->state
= RT_ITER_STATE_PAUSED
;
779 * route_table_iter_cleanup
781 * Release any resources held by the iterator.
783 void route_table_iter_cleanup(route_table_iter_t
*iter
)
785 if (iter
->state
== RT_ITER_STATE_ITERATING
) {
786 route_unlock_node(iter
->current
);
787 iter
->current
= NULL
;
789 assert(!iter
->current
);
792 * Set the state to RT_ITER_STATE_DONE to make any
793 * route_table_iter_next() calls on this iterator return NULL.
795 iter
->state
= RT_ITER_STATE_DONE
;