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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#include <inttypes.h>
#include <stdbool.h>
#include <isc/mem.h>
#include <isc/radix.h>
#include <isc/util.h>
#include <dns/acl.h>
static void
destroy_iptable(dns_iptable_t *dtab);
/*
* Create a new IP table and the underlying radix structure
*/
isc_result_t
dns_iptable_create(isc_mem_t *mctx, dns_iptable_t **target) {
isc_result_t result;
dns_iptable_t *tab;
tab = isc_mem_get(mctx, sizeof(*tab));
tab->mctx = NULL;
isc_mem_attach(mctx, &tab->mctx);
isc_refcount_init(&tab->refcount, 1);
tab->radix = NULL;
tab->magic = DNS_IPTABLE_MAGIC;
result = isc_radix_create(mctx, &tab->radix, RADIX_MAXBITS);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
*target = tab;
return (ISC_R_SUCCESS);
cleanup:
dns_iptable_detach(&tab);
return (result);
}
static bool dns_iptable_neg = false;
static bool dns_iptable_pos = true;
/*
* Add an IP prefix to an existing IP table
*/
isc_result_t
dns_iptable_addprefix(dns_iptable_t *tab, const isc_netaddr_t *addr,
uint16_t bitlen, bool pos) {
isc_result_t result;
isc_prefix_t pfx;
isc_radix_node_t *node = NULL;
int i;
INSIST(DNS_IPTABLE_VALID(tab));
INSIST(tab->radix != NULL);
NETADDR_TO_PREFIX_T(addr, pfx, bitlen);
result = isc_radix_insert(tab->radix, &node, NULL, &pfx);
if (result != ISC_R_SUCCESS) {
isc_refcount_destroy(&pfx.refcount);
return (result);
}
/* If a node already contains data, don't overwrite it */
if (pfx.family == AF_UNSPEC) {
/* "any" or "none" */
INSIST(pfx.bitlen == 0);
for (i = 0; i < RADIX_FAMILIES; i++) {
if (node->data[i] == NULL) {
node->data[i] = pos ? &dns_iptable_pos
: &dns_iptable_neg;
}
}
} else {
/* any other prefix */
int fam = ISC_RADIX_FAMILY(&pfx);
if (node->data[fam] == NULL) {
node->data[fam] = pos ? &dns_iptable_pos
: &dns_iptable_neg;
}
}
isc_refcount_destroy(&pfx.refcount);
return (ISC_R_SUCCESS);
}
/*
* Merge one IP table into another one.
*/
isc_result_t
dns_iptable_merge(dns_iptable_t *tab, dns_iptable_t *source, bool pos) {
isc_result_t result;
isc_radix_node_t *node, *new_node;
int i, max_node = 0;
RADIX_WALK(source->radix->head, node) {
new_node = NULL;
result = isc_radix_insert(tab->radix, &new_node, node, NULL);
if (result != ISC_R_SUCCESS) {
return (result);
}
/*
* If we're negating a nested ACL, then we should
* reverse the sense of every node. However, this
* could lead to a negative node in a nested ACL
* becoming a positive match in the parent, which
* could be a security risk. To prevent this, we
* just leave the negative nodes negative.
*/
for (i = 0; i < RADIX_FAMILIES; i++) {
if (!pos) {
if (node->data[i] && *(bool *)node->data[i]) {
new_node->data[i] = &dns_iptable_neg;
}
}
if (node->node_num[i] > max_node) {
max_node = node->node_num[i];
}
}
}
RADIX_WALK_END;
tab->radix->num_added_node += max_node;
return (ISC_R_SUCCESS);
}
void
dns_iptable_attach(dns_iptable_t *source, dns_iptable_t **target) {
REQUIRE(DNS_IPTABLE_VALID(source));
isc_refcount_increment(&source->refcount);
*target = source;
}
void
dns_iptable_detach(dns_iptable_t **tabp) {
REQUIRE(tabp != NULL && DNS_IPTABLE_VALID(*tabp));
dns_iptable_t *tab = *tabp;
*tabp = NULL;
if (isc_refcount_decrement(&tab->refcount) == 1) {
isc_refcount_destroy(&tab->refcount);
destroy_iptable(tab);
}
}
static void
destroy_iptable(dns_iptable_t *dtab) {
REQUIRE(DNS_IPTABLE_VALID(dtab));
if (dtab->radix != NULL) {
isc_radix_destroy(dtab->radix, NULL);
dtab->radix = NULL;
}
dtab->magic = 0;
isc_mem_putanddetach(&dtab->mctx, dtab, sizeof(*dtab));
}
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