radix.c revision df925e6c66d45d960fbac0383169763967d2111c
/*
* Copyright (C) 2007-2009, 2011, 2012 Internet Systems Consortium, Inc. ("ISC")
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id$ */
/*
* This source was adapted from MRT's RCS Ids:
* Id: radix.c,v 1.10.2.1 1999/11/29 05:16:24 masaki Exp
* Id: prefix.c,v 1.37.2.9 2000/03/10 02:53:19 labovit Exp
*/
#include <config.h>
#include <isc/mem.h>
#include <isc/types.h>
#include <isc/util.h>
#include <isc/radix.h>
static isc_result_t
_new_prefix(isc_mem_t *mctx, isc_prefix_t **target, int family,
void *dest, int bitlen);
static void
_deref_prefix(isc_prefix_t *prefix);
static isc_result_t
_ref_prefix(isc_mem_t *mctx, isc_prefix_t **target, isc_prefix_t *prefix);
static int
_comp_with_mask(void *addr, void *dest, u_int mask);
static void
_clear_radix(isc_radix_tree_t *radix, isc_radix_destroyfunc_t func);
static isc_result_t
_new_prefix(isc_mem_t *mctx, isc_prefix_t **target, int family, void *dest,
int bitlen)
{
isc_prefix_t *prefix;
REQUIRE(target != NULL);
if (family != AF_INET6 && family != AF_INET && family != AF_UNSPEC)
return (ISC_R_NOTIMPLEMENTED);
prefix = isc_mem_get(mctx, sizeof(isc_prefix_t));
if (prefix == NULL)
return (ISC_R_NOMEMORY);
if (family == AF_INET6) {
prefix->bitlen = (bitlen >= 0) ? bitlen : 128;
memcpy(&prefix->add.sin6, dest, 16);
} else {
/* AF_UNSPEC is "any" or "none"--treat it as AF_INET */
prefix->bitlen = (bitlen >= 0) ? bitlen : 32;
memcpy(&prefix->add.sin, dest, 4);
}
prefix->family = family;
prefix->mctx = NULL;
isc_mem_attach(mctx, &prefix->mctx);
isc_refcount_init(&prefix->refcount, 1);
*target = prefix;
return (ISC_R_SUCCESS);
}
static void
_deref_prefix(isc_prefix_t *prefix) {
int refs;
if (prefix == NULL)
return;
isc_refcount_decrement(&prefix->refcount, &refs);
if (refs <= 0) {
isc_refcount_destroy(&prefix->refcount);
isc_mem_putanddetach(&prefix->mctx, prefix,
sizeof(isc_prefix_t));
}
}
static isc_result_t
_ref_prefix(isc_mem_t *mctx, isc_prefix_t **target, isc_prefix_t *prefix) {
INSIST(prefix != NULL);
INSIST((prefix->family == AF_INET && prefix->bitlen <= 32) ||
(prefix->family == AF_INET6 && prefix->bitlen <= 128) ||
(prefix->family == AF_UNSPEC && prefix->bitlen == 0));
REQUIRE(target != NULL && *target == NULL);
/*
* If this prefix is a static allocation, copy it into new memory.
* (Note, the refcount still has to be destroyed by the calling
* routine.)
*/
if (isc_refcount_current(&prefix->refcount) == 0) {
isc_result_t ret;
ret = _new_prefix(mctx, target, prefix->family,
&prefix->add, prefix->bitlen);
return (ret);
}
isc_refcount_increment(&prefix->refcount, NULL);
*target = prefix;
return (ISC_R_SUCCESS);
}
static int
_comp_with_mask(void *addr, void *dest, u_int mask) {
/* Mask length of zero matches everything */
if (mask == 0)
return (1);
if (memcmp(addr, dest, mask / 8) == 0) {
int n = mask / 8;
int m = ((~0) << (8 - (mask % 8)));
if ((mask % 8) == 0 ||
(((u_char *)addr)[n] & m) == (((u_char *)dest)[n] & m))
return (1);
}
return (0);
}
isc_result_t
isc_radix_create(isc_mem_t *mctx, isc_radix_tree_t **target, int maxbits) {
isc_radix_tree_t *radix;
REQUIRE(target != NULL && *target == NULL);
radix = isc_mem_get(mctx, sizeof(isc_radix_tree_t));
if (radix == NULL)
return (ISC_R_NOMEMORY);
radix->mctx = NULL;
isc_mem_attach(mctx, &radix->mctx);
radix->maxbits = maxbits;
radix->head = NULL;
radix->num_active_node = 0;
radix->num_added_node = 0;
RUNTIME_CHECK(maxbits <= RADIX_MAXBITS); /* XXX */
radix->magic = RADIX_TREE_MAGIC;
*target = radix;
return (ISC_R_SUCCESS);
}
/*
* if func is supplied, it will be called as func(node->data)
* before deleting the node
*/
static void
_clear_radix(isc_radix_tree_t *radix, isc_radix_destroyfunc_t func) {
REQUIRE(radix != NULL);
if (radix->head != NULL) {
isc_radix_node_t *Xstack[RADIX_MAXBITS+1];
isc_radix_node_t **Xsp = Xstack;
isc_radix_node_t *Xrn = radix->head;
while (Xrn != NULL) {
isc_radix_node_t *l = Xrn->l;
isc_radix_node_t *r = Xrn->r;
if (Xrn->prefix != NULL) {
_deref_prefix(Xrn->prefix);
if (func != NULL && (Xrn->data[0] != NULL ||
Xrn->data[1] != NULL))
func(Xrn->data);
} else {
INSIST(Xrn->data[0] == NULL &&
Xrn->data[1] == NULL);
}
isc_mem_put(radix->mctx, Xrn, sizeof(*Xrn));
radix->num_active_node--;
if (l != NULL) {
if (r != NULL) {
*Xsp++ = r;
}
Xrn = l;
} else if (r != NULL) {
Xrn = r;
} else if (Xsp != Xstack) {
Xrn = *(--Xsp);
} else {
Xrn = NULL;
}
}
}
RUNTIME_CHECK(radix->num_active_node == 0);
}
void
isc_radix_destroy(isc_radix_tree_t *radix, isc_radix_destroyfunc_t func) {
REQUIRE(radix != NULL);
_clear_radix(radix, func);
isc_mem_putanddetach(&radix->mctx, radix, sizeof(*radix));
}
/*
* func will be called as func(node->prefix, node->data)
*/
void
isc_radix_process(isc_radix_tree_t *radix, isc_radix_processfunc_t func) {
isc_radix_node_t *node;
REQUIRE(func != NULL);
RADIX_WALK(radix->head, node) {
func(node->prefix, node->data);
} RADIX_WALK_END;
}
isc_result_t
isc_radix_search(isc_radix_tree_t *radix, isc_radix_node_t **target,
isc_prefix_t *prefix)
{
isc_radix_node_t *node;
isc_radix_node_t *stack[RADIX_MAXBITS + 1];
u_char *addr;
isc_uint32_t bitlen;
int tfamily = -1;
int cnt = 0;
REQUIRE(radix != NULL);
REQUIRE(prefix != NULL);
REQUIRE(target != NULL && *target == NULL);
RUNTIME_CHECK(prefix->bitlen <= radix->maxbits);
*target = NULL;
if (radix->head == NULL) {
return (ISC_R_NOTFOUND);
}
node = radix->head;
addr = isc_prefix_touchar(prefix);
bitlen = prefix->bitlen;
while (node->bit < bitlen) {
if (node->prefix)
stack[cnt++] = node;
if (BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
node = node->r;
else
node = node->l;
if (node == NULL)
break;
}
if (node && node->prefix)
stack[cnt++] = node;
while (cnt-- > 0) {
node = stack[cnt];
if (_comp_with_mask(isc_prefix_tochar(node->prefix),
isc_prefix_tochar(prefix),
node->prefix->bitlen)) {
if (node->node_num[ISC_IS6(prefix->family)] != -1 &&
((*target == NULL) ||
(*target)->node_num[ISC_IS6(tfamily)] >
node->node_num[ISC_IS6(prefix->family)])) {
*target = node;
tfamily = prefix->family;
}
}
}
if (*target == NULL) {
return (ISC_R_NOTFOUND);
} else {
return (ISC_R_SUCCESS);
}
}
isc_result_t
isc_radix_insert(isc_radix_tree_t *radix, isc_radix_node_t **target,
isc_radix_node_t *source, isc_prefix_t *prefix)
{
isc_radix_node_t *node, *new_node, *parent, *glue = NULL;
u_char *addr, *test_addr;
isc_uint32_t bitlen, fam, check_bit, differ_bit;
isc_uint32_t i, j, r;
isc_result_t result;
REQUIRE(radix != NULL);
REQUIRE(target != NULL && *target == NULL);
REQUIRE(prefix != NULL || (source != NULL && source->prefix != NULL));
RUNTIME_CHECK(prefix == NULL || prefix->bitlen <= radix->maxbits);
if (prefix == NULL)
prefix = source->prefix;
INSIST(prefix != NULL);
bitlen = prefix->bitlen;
fam = prefix->family;
if (radix->head == NULL) {
node = isc_mem_get(radix->mctx, sizeof(isc_radix_node_t));
if (node == NULL)
return (ISC_R_NOMEMORY);
node->bit = bitlen;
node->node_num[0] = node->node_num[1] = -1;
node->prefix = NULL;
result = _ref_prefix(radix->mctx, &node->prefix, prefix);
if (result != ISC_R_SUCCESS) {
isc_mem_put(radix->mctx, node,
sizeof(isc_radix_node_t));
return (result);
}
node->parent = NULL;
node->l = node->r = NULL;
if (source != NULL) {
/*
* If source is non-NULL, then we're merging in a
* node from an existing radix tree. To keep
* the node_num values consistent, the calling
* function will add the total number of nodes
* added to num_added_node at the end of
* the merge operation--we don't do it here.
*/
if (source->node_num[0] != -1)
node->node_num[0] = radix->num_added_node +
source->node_num[0];
if (source->node_num[1] != -1)
node->node_num[1] = radix->num_added_node +
source->node_num[1];
node->data[0] = source->data[0];
node->data[1] = source->data[1];
} else {
if (fam == AF_UNSPEC) {
/* "any" or "none" */
node->node_num[0] = node->node_num[1] =
++radix->num_added_node;
} else {
node->node_num[ISC_IS6(fam)] =
++radix->num_added_node;
}
node->data[0] = NULL;
node->data[1] = NULL;
}
radix->head = node;
radix->num_active_node++;
*target = node;
return (ISC_R_SUCCESS);
}
addr = isc_prefix_touchar(prefix);
node = radix->head;
while (node->bit < bitlen || node->prefix == NULL) {
if (node->bit < radix->maxbits &&
BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
{
if (node->r == NULL)
break;
node = node->r;
} else {
if (node->l == NULL)
break;
node = node->l;
}
INSIST(node != NULL);
}
INSIST(node->prefix != NULL);
test_addr = isc_prefix_touchar(node->prefix);
/* Find the first bit different. */
check_bit = (node->bit < bitlen) ? node->bit : bitlen;
differ_bit = 0;
for (i = 0; i*8 < check_bit; i++) {
if ((r = (addr[i] ^ test_addr[i])) == 0) {
differ_bit = (i + 1) * 8;
continue;
}
/* I know the better way, but for now. */
for (j = 0; j < 8; j++) {
if (BIT_TEST (r, (0x80 >> j)))
break;
}
/* Must be found. */
INSIST(j < 8);
differ_bit = i * 8 + j;
break;
}
if (differ_bit > check_bit)
differ_bit = check_bit;
parent = node->parent;
while (parent != NULL && parent->bit >= differ_bit) {
node = parent;
parent = node->parent;
}
if (differ_bit == bitlen && node->bit == bitlen) {
if (node->prefix != NULL) {
/* Set node_num only if it hasn't been set before */
if (source != NULL) {
/* Merging node */
if (node->node_num[0] == -1 &&
source->node_num[0] != -1) {
node->node_num[0] =
radix->num_added_node +
source->node_num[0];
node->data[0] = source->data[0];
}
if (node->node_num[1] == -1 &&
source->node_num[0] != -1) {
node->node_num[1] =
radix->num_added_node +
source->node_num[1];
node->data[1] = source->data[1];
}
} else {
if (fam == AF_UNSPEC) {
/* "any" or "none" */
int next = radix->num_added_node + 1;
if (node->node_num[0] == -1) {
node->node_num[0] = next;
radix->num_added_node = next;
}
if (node->node_num[1] == -1) {
node->node_num[1] = next;
radix->num_added_node = next;
}
} else {
if (node->node_num[ISC_IS6(fam)] == -1)
node->node_num[ISC_IS6(fam)]
= ++radix->num_added_node;
}
}
*target = node;
return (ISC_R_SUCCESS);
} else {
result = _ref_prefix(radix->mctx,
&node->prefix, prefix);
if (result != ISC_R_SUCCESS)
return (result);
}
INSIST(node->data[0] == NULL && node->node_num[0] == -1 &&
node->data[1] == NULL && node->node_num[1] == -1);
if (source != NULL) {
/* Merging node */
if (source->node_num[0] != -1) {
node->node_num[0] = radix->num_added_node +
source->node_num[0];
node->data[0] = source->data[0];
}
if (source->node_num[1] != -1) {
node->node_num[1] = radix->num_added_node +
source->node_num[1];
node->data[1] = source->data[1];
}
} else {
if (fam == AF_UNSPEC) {
/* "any" or "none" */
node->node_num[0] = node->node_num[1] =
++radix->num_added_node;
} else {
node->node_num[ISC_IS6(fam)] =
++radix->num_added_node;
}
}
*target = node;
return (ISC_R_SUCCESS);
}
new_node = isc_mem_get(radix->mctx, sizeof(isc_radix_node_t));
if (new_node == NULL)
return (ISC_R_NOMEMORY);
if (node->bit != differ_bit && bitlen != differ_bit) {
glue = isc_mem_get(radix->mctx, sizeof(isc_radix_node_t));
if (glue == NULL) {
isc_mem_put(radix->mctx, new_node,
sizeof(isc_radix_node_t));
return (ISC_R_NOMEMORY);
}
}
new_node->bit = bitlen;
new_node->prefix = NULL;
result = _ref_prefix(radix->mctx, &new_node->prefix, prefix);
if (result != ISC_R_SUCCESS) {
isc_mem_put(radix->mctx, new_node, sizeof(isc_radix_node_t));
if (glue != NULL)
isc_mem_put(radix->mctx, glue,
sizeof(isc_radix_node_t));
return (result);
}
new_node->parent = NULL;
new_node->l = new_node->r = NULL;
new_node->node_num[0] = new_node->node_num[1] = -1;
radix->num_active_node++;
if (source != NULL) {
/* Merging node */
if (source->node_num[0] != -1)
new_node->node_num[0] = radix->num_added_node +
source->node_num[0];
if (source->node_num[1] != -1)
new_node->node_num[1] = radix->num_added_node +
source->node_num[1];
new_node->data[0] = source->data[0];
new_node->data[1] = source->data[1];
} else {
if (fam == AF_UNSPEC) {
/* "any" or "none" */
new_node->node_num[0] = new_node->node_num[1] =
++radix->num_added_node;
} else {
new_node->node_num[ISC_IS6(fam)] =
++radix->num_added_node;
}
new_node->data[0] = NULL;
new_node->data[1] = NULL;
}
if (node->bit == differ_bit) {
INSIST(glue == NULL);
new_node->parent = node;
if (node->bit < radix->maxbits &&
BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
{
INSIST(node->r == NULL);
node->r = new_node;
} else {
INSIST(node->l == NULL);
node->l = new_node;
}
*target = new_node;
return (ISC_R_SUCCESS);
}
if (bitlen == differ_bit) {
INSIST(glue == NULL);
if (bitlen < radix->maxbits &&
BIT_TEST(test_addr[bitlen >> 3], 0x80 >> (bitlen & 0x07))) {
new_node->r = node;
} else {
new_node->l = node;
}
new_node->parent = node->parent;
if (node->parent == NULL) {
INSIST(radix->head == node);
radix->head = new_node;
} else if (node->parent->r == node) {
node->parent->r = new_node;
} else {
node->parent->l = new_node;
}
node->parent = new_node;
} else {
INSIST(glue != NULL);
glue->bit = differ_bit;
glue->prefix = NULL;
glue->parent = node->parent;
glue->data[0] = glue->data[1] = NULL;
glue->node_num[0] = glue->node_num[1] = -1;
radix->num_active_node++;
if (differ_bit < radix->maxbits &&
BIT_TEST(addr[differ_bit>>3], 0x80 >> (differ_bit & 07))) {
glue->r = new_node;
glue->l = node;
} else {
glue->r = node;
glue->l = new_node;
}
new_node->parent = glue;
if (node->parent == NULL) {
INSIST(radix->head == node);
radix->head = glue;
} else if (node->parent->r == node) {
node->parent->r = glue;
} else {
node->parent->l = glue;
}
node->parent = glue;
}
*target = new_node;
return (ISC_R_SUCCESS);
}
void
isc_radix_remove(isc_radix_tree_t *radix, isc_radix_node_t *node) {
isc_radix_node_t *parent, *child;
REQUIRE(radix != NULL);
REQUIRE(node != NULL);
if (node->r && node->l) {
/*
* This might be a placeholder node -- have to check and
* make sure there is a prefix associated with it!
*/
if (node->prefix != NULL)
_deref_prefix(node->prefix);
node->prefix = NULL;
node->data[0] = node->data[1] = NULL;
return;
}
if (node->r == NULL && node->l == NULL) {
parent = node->parent;
_deref_prefix(node->prefix);
isc_mem_put(radix->mctx, node, sizeof(*node));
radix->num_active_node--;
if (parent == NULL) {
INSIST(radix->head == node);
radix->head = NULL;
return;
}
if (parent->r == node) {
parent->r = NULL;
child = parent->l;
} else {
INSIST(parent->l == node);
parent->l = NULL;
child = parent->r;
}
if (parent->prefix)
return;
/* We need to remove parent too. */
if (parent->parent == NULL) {
INSIST(radix->head == parent);
radix->head = child;
} else if (parent->parent->r == parent) {
parent->parent->r = child;
} else {
INSIST(parent->parent->l == parent);
parent->parent->l = child;
}
child->parent = parent->parent;
isc_mem_put(radix->mctx, parent, sizeof(*parent));
radix->num_active_node--;
return;
}
if (node->r) {
child = node->r;
} else {
INSIST(node->l != NULL);
child = node->l;
}
parent = node->parent;
child->parent = parent;
_deref_prefix(node->prefix);
isc_mem_put(radix->mctx, node, sizeof(*node));
radix->num_active_node--;
if (parent == NULL) {
INSIST(radix->head == node);
radix->head = child;
return;
}
if (parent->r == node) {
parent->r = child;
} else {
INSIST(parent->l == node);
parent->l = child;
}
}
/*
Local Variables:
c-basic-offset: 4
indent-tabs-mode: t
End:
*/