Files
smartdns/src/lib/radix.c
2019-12-15 01:27:44 +08:00

677 lines
16 KiB
C

/*
* Copyright (c) 1999-2000
*
* The Regents of the University of Michigan ("The Regents") and
* Merit Network, Inc. All rights reserved. Redistribution and use
* in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of
* this software must display the following acknowledgement:
*
* This product includes software developed by the University of
* Michigan, Merit Network, Inc., and their contributors.
*
* 4. Neither the name of the University, Merit Network, nor the
* names of their contributors may be used to endorse or
* promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL TH E REGENTS
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HO WEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Portions Copyright (c) 2004,2005 Damien Miller <djm@mindrot.org>
*
* Permission to use, copy, modify, and 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "radix.h"
/* $Id: radix.c,v 1.17 2007/10/24 06:04:31 djm Exp $ */
/*
* Originally from MRT include/defs.h
* $MRTId: defs.h,v 1.1.1.1 2000/08/14 18:46:10 labovit Exp $
*/
#define BIT_TEST(f, b) ((f) & (b))
/*
* Originally from MRT include/mrt.h
* $MRTId: mrt.h,v 1.1.1.1 2000/08/14 18:46:10 labovit Exp $
*/
#define prefix_tochar(prefix) ((char *)&(prefix)->add)
#define prefix_touchar(prefix) ((unsigned char *)&(prefix)->add)
/*
* Originally from MRT lib/mrt/prefix.c
* $MRTId: prefix.c,v 1.1.1.1 2000/08/14 18:46:11 labovit Exp $
*/
static int
comp_with_mask(unsigned char *addr, unsigned char *dest, unsigned int mask)
{
if (memcmp(addr, dest, mask / 8) == 0) {
unsigned int n = mask / 8;
unsigned int m = ((~0) << (8 - (mask % 8)));
if (mask % 8 == 0 || (addr[n] & m) == (dest[n] & m))
return (1);
}
return (0);
}
static prefix_t
*New_Prefix2(int family, void *dest, int bitlen, prefix_t *prefix)
{
int dynamic_allocated = 0;
int default_bitlen = 32;
if (family == AF_INET6) {
default_bitlen = 128;
if (prefix == NULL) {
if ((prefix = malloc(sizeof(*prefix))) == NULL)
return (NULL);
memset(prefix, '\0', sizeof(*prefix));
dynamic_allocated++;
}
memcpy(&prefix->add.sin6, dest, 16);
} else if (family == AF_INET) {
if (prefix == NULL) {
if ((prefix = malloc(sizeof(*prefix))) == NULL)
return (NULL);
memset(prefix, '\0', sizeof(*prefix));
dynamic_allocated++;
}
memcpy(&prefix->add.sin, dest, 4);
} else
return (NULL);
prefix->bitlen = (bitlen >= 0) ? bitlen : default_bitlen;
prefix->family = family;
prefix->ref_count = 0;
if (dynamic_allocated)
prefix->ref_count++;
return (prefix);
}
static prefix_t
*Ref_Prefix(prefix_t *prefix)
{
if (prefix == NULL)
return (NULL);
if (prefix->ref_count == 0) {
/* make a copy in case of a static prefix */
return (New_Prefix2(prefix->family, &prefix->add,
prefix->bitlen, NULL));
}
prefix->ref_count++;
return (prefix);
}
void
Deref_Prefix(prefix_t *prefix)
{
if (prefix == NULL)
return;
prefix->ref_count--;
if (prefix->ref_count <= 0) {
free(prefix);
return;
}
}
/*
* Originally from MRT lib/radix/radix.c
* $MRTId: radix.c,v 1.1.1.1 2000/08/14 18:46:13 labovit Exp $
*/
/* these routines support continuous mask only */
radix_tree_t
*New_Radix(void)
{
radix_tree_t *radix;
if ((radix = malloc(sizeof(*radix))) == NULL)
return (NULL);
memset(radix, '\0', sizeof(*radix));
radix->maxbits = 128;
radix->head = NULL;
radix->num_active_node = 0;
return (radix);
}
/*
* if func is supplied, it will be called as func(node->data)
* before deleting the node
*/
static void
Clear_Radix(radix_tree_t *radix, rdx_cb_t func, void *cbctx)
{
if (radix->head) {
radix_node_t *Xstack[RADIX_MAXBITS + 1];
radix_node_t **Xsp = Xstack;
radix_node_t *Xrn = radix->head;
while (Xrn) {
radix_node_t *l = Xrn->l;
radix_node_t *r = Xrn->r;
if (Xrn->prefix) {
Deref_Prefix(Xrn->prefix);
if (Xrn->data && func)
func(Xrn, cbctx);
}
free(Xrn);
radix->num_active_node--;
if (l) {
if (r)
*Xsp++ = r;
Xrn = l;
} else if (r) {
Xrn = r;
} else if (Xsp != Xstack) {
Xrn = *(--Xsp);
} else {
Xrn = (radix_node_t *) 0;
}
}
}
}
void
Destroy_Radix(radix_tree_t *radix, rdx_cb_t func, void *cbctx)
{
if (radix == NULL) {
return;
}
Clear_Radix(radix, func, cbctx);
free(radix);
}
/*
* if func is supplied, it will be called as func(node->prefix, node->data)
*/
void
radix_process(radix_tree_t *radix, rdx_cb_t func, void *cbctx)
{
radix_node_t *node;
RADIX_WALK(radix->head, node) {
func(node, cbctx);
} RADIX_WALK_END;
}
radix_node_t
*radix_search_exact(radix_tree_t *radix, prefix_t *prefix)
{
radix_node_t *node;
unsigned char *addr;
unsigned int bitlen;
if (radix->head == NULL)
return (NULL);
node = radix->head;
addr = prefix_touchar(prefix);
bitlen = prefix->bitlen;
while (node->bit < bitlen) {
if (BIT_TEST(addr[node->bit >> 3], 0x80 >> (node->bit & 0x07)))
node = node->r;
else
node = node->l;
if (node == NULL)
return (NULL);
}
if (node->bit > bitlen || node->prefix == NULL)
return (NULL);
if (comp_with_mask(prefix_touchar(node->prefix),
prefix_touchar(prefix), bitlen))
return (node);
return (NULL);
}
/* if inclusive != 0, "best" may be the given prefix itself */
static radix_node_t
*radix_search_best2(radix_tree_t *radix, prefix_t *prefix, int inclusive)
{
radix_node_t *node;
radix_node_t *stack[RADIX_MAXBITS + 1] = {0};
unsigned char *addr;
unsigned int bitlen;
int cnt = 0;
if (radix->head == NULL)
return (NULL);
node = radix->head;
addr = 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 (inclusive && node && node->prefix)
stack[cnt++] = node;
if (cnt <= 0)
return (NULL);
while (--cnt >= 0) {
node = stack[cnt];
if (comp_with_mask(prefix_touchar(node->prefix),
prefix_touchar(prefix), node->prefix->bitlen))
return (node);
}
return (NULL);
}
radix_node_t
*radix_search_best(radix_tree_t *radix, prefix_t *prefix)
{
return (radix_search_best2(radix, prefix, 1));
}
radix_node_t
*radix_lookup(radix_tree_t *radix, prefix_t *prefix)
{
radix_node_t *node, *new_node, *parent, *glue;
unsigned char *addr, *test_addr;
unsigned int bitlen, check_bit, differ_bit;
unsigned int i, j, r;
if (radix->head == NULL) {
if ((node = malloc(sizeof(*node))) == NULL)
return (NULL);
memset(node, '\0', sizeof(*node));
node->bit = prefix->bitlen;
node->prefix = Ref_Prefix(prefix);
node->parent = NULL;
node->l = node->r = NULL;
node->data = NULL;
radix->head = node;
radix->num_active_node++;
return (node);
}
addr = prefix_touchar(prefix);
bitlen = prefix->bitlen;
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;
}
}
test_addr = 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 */
differ_bit = i * 8 + j;
break;
}
if (differ_bit > check_bit)
differ_bit = check_bit;
parent = node->parent;
while (parent && parent->bit >= differ_bit) {
node = parent;
parent = node->parent;
}
if (differ_bit == bitlen && node->bit == bitlen) {
if (node->prefix == NULL)
node->prefix = Ref_Prefix(prefix);
return (node);
}
if ((new_node = malloc(sizeof(*new_node))) == NULL)
return (NULL);
memset(new_node, '\0', sizeof(*new_node));
new_node->bit = prefix->bitlen;
new_node->prefix = Ref_Prefix(prefix);
new_node->parent = NULL;
new_node->l = new_node->r = NULL;
new_node->data = NULL;
radix->num_active_node++;
if (node->bit == differ_bit) {
new_node->parent = node;
if (node->bit < radix->maxbits && BIT_TEST(addr[node->bit >> 3],
0x80 >> (node->bit & 0x07)))
node->r = new_node;
else
node->l = new_node;
return (new_node);
}
if (bitlen == differ_bit) {
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)
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 {
if ((glue = malloc(sizeof(*glue))) == NULL)
return (NULL);
memset(glue, '\0', sizeof(*glue));
glue->bit = differ_bit;
glue->prefix = NULL;
glue->parent = node->parent;
glue->data = NULL;
radix->num_active_node++;
if (differ_bit < radix->maxbits &&
BIT_TEST(addr[differ_bit >> 3],
0x80 >> (differ_bit & 0x07))) {
glue->r = new_node;
glue->l = node;
} else {
glue->r = node;
glue->l = new_node;
}
new_node->parent = glue;
if (node->parent == NULL)
radix->head = glue;
else if (node->parent->r == node)
node->parent->r = glue;
else
node->parent->l = glue;
node->parent = glue;
}
return (new_node);
}
void
radix_remove(radix_tree_t *radix, radix_node_t *node)
{
radix_node_t *parent, *child;
if (node->r && node->l) {
/*
* this might be a placeholder node -- have to check and make
* sure there is a prefix aossciated with it !
*/
if (node->prefix != NULL)
Deref_Prefix(node->prefix);
node->prefix = NULL;
/* Also I needed to clear data pointer -- masaki */
node->data = NULL;
return;
}
if (node->r == NULL && node->l == NULL) {
parent = node->parent;
Deref_Prefix(node->prefix);
free(node);
radix->num_active_node--;
if (parent == NULL) {
radix->head = NULL;
return;
}
if (parent->r == node) {
parent->r = NULL;
child = parent->l;
} else {
parent->l = NULL;
child = parent->r;
}
if (parent->prefix)
return;
/* we need to remove parent too */
if (parent->parent == NULL)
radix->head = child;
else if (parent->parent->r == parent)
parent->parent->r = child;
else
parent->parent->l = child;
child->parent = parent->parent;
free(parent);
radix->num_active_node--;
return;
}
if (node->r)
child = node->r;
else
child = node->l;
parent = node->parent;
child->parent = parent;
Deref_Prefix(node->prefix);
free(node);
radix->num_active_node--;
if (parent == NULL) {
radix->head = child;
return;
}
if (parent->r == node)
parent->r = child;
else
parent->l = child;
}
/* Local additions */
static void
sanitise_mask(unsigned char *addr, unsigned int masklen, unsigned int maskbits)
{
unsigned int i = masklen / 8;
unsigned int j = masklen % 8;
if (j != 0) {
addr[i] &= (~0) << (8 - j);
i++;
}
for (; i < maskbits / 8; i++)
addr[i] = 0;
}
prefix_t
*prefix_pton(const char *string, long len, prefix_t *prefix, const char **errmsg)
{
char save[256], *cp, *ep;
struct addrinfo hints, *ai;
void *addr;
prefix_t *ret;
size_t slen;
int r;
ret = NULL;
/* Copy the string to parse, because we modify it */
if ((slen = strlen(string) + 1) > sizeof(save)) {
*errmsg = "string too long";
return (NULL);
}
memcpy(save, string, slen);
if ((cp = strchr(save, '/')) != NULL) {
if (len != -1 ) {
*errmsg = "masklen specified twice";
return (NULL);
}
*cp++ = '\0';
len = strtol(cp, &ep, 10);
if (*cp == '\0' || *ep != '\0' || len < 0) {
*errmsg = "could not parse masklen";
return (NULL);
}
/* More checks below */
}
memset(&hints, '\0', sizeof(hints));
hints.ai_flags = AI_NUMERICHOST;
if ((r = getaddrinfo(save, NULL, &hints, &ai)) != 0) {
snprintf(save, sizeof(save), "getaddrinfo: %s:",
gai_strerror(r));
*errmsg = save;
return NULL;
}
if (ai == NULL || ai->ai_addr == NULL) {
*errmsg = "getaddrinfo returned no result";
goto out;
}
switch (ai->ai_addr->sa_family) {
case AF_INET:
if (len == -1)
len = 32;
else if (len < 0 || len > 32)
goto out;
addr = &((struct sockaddr_in *) ai->ai_addr)->sin_addr;
sanitise_mask(addr, len, 32);
break;
case AF_INET6:
if (len == -1)
len = 128;
else if (len < 0 || len > 128)
goto out;
addr = &((struct sockaddr_in6 *) ai->ai_addr)->sin6_addr;
sanitise_mask(addr, len, 128);
break;
default:
goto out;
}
ret = New_Prefix2(ai->ai_addr->sa_family, addr, len, prefix);
if (ret == NULL)
*errmsg = "New_Prefix2 failed";
out:
freeaddrinfo(ai);
return (ret);
}
prefix_t
*prefix_from_blob(unsigned char *blob, int len, int prefixlen, prefix_t *prefix)
{
int family, maxprefix;
switch (len) {
case 4:
/* Assume AF_INET */
family = AF_INET;
maxprefix = 32;
break;
case 16:
/* Assume AF_INET6 */
family = AF_INET6;
maxprefix = 128;
break;
default:
/* Who knows? */
return NULL;
}
if (prefixlen == -1)
prefixlen = maxprefix;
if (prefixlen < 0 || prefixlen > maxprefix)
return NULL;
return (New_Prefix2(family, blob, prefixlen, prefix));
}
const char *
prefix_addr_ntop(prefix_t *prefix, char *buf, size_t len)
{
return (inet_ntop(prefix->family, &prefix->add, buf, len));
}
const char *
prefix_ntop(prefix_t *prefix, char *buf, size_t len)
{
char addrbuf[128];
if (prefix_addr_ntop(prefix, addrbuf, sizeof(addrbuf)) == NULL)
return (NULL);
snprintf(buf, len, "%s/%d", addrbuf, prefix->bitlen);
return (buf);
}