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/*
* Copyright (C) 2004-2006 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1999-2002 Internet Software Consortium.
*
* 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 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: acl.c,v 1.25.18.5 2006/03/02 00:37:21 marka Exp $ */
/*! \file */
#include <config.h>
#include <isc/mem.h>
#include <isc/string.h>
#include <isc/util.h>
#include <dns/acl.h>
isc_result_t
dns_acl_create(isc_mem_t *mctx, int n, dns_acl_t **target) {
isc_result_t result;
dns_acl_t *acl;
/*
* Work around silly limitation of isc_mem_get().
*/
if (n == 0)
n = 1;
acl = isc_mem_get(mctx, sizeof(*acl));
if (acl == NULL)
return (ISC_R_NOMEMORY);
acl->mctx = mctx;
acl->name = NULL;
result = isc_refcount_init(&acl->refcount, 1);
if (result != ISC_R_SUCCESS) {
isc_mem_put(mctx, acl, sizeof(*acl));
return (result);
}
acl->elements = NULL;
acl->alloc = 0;
acl->length = 0;
ISC_LINK_INIT(acl, nextincache);
/*
* Must set magic early because we use dns_acl_detach() to clean up.
*/
acl->magic = DNS_ACL_MAGIC;
acl->elements = isc_mem_get(mctx, n * sizeof(dns_aclelement_t));
if (acl->elements == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup;
}
acl->alloc = n;
memset(acl->elements, 0, n * sizeof(dns_aclelement_t));
*target = acl;
return (ISC_R_SUCCESS);
cleanup:
dns_acl_detach(&acl);
return (result);
}
isc_result_t
dns_acl_appendelement(dns_acl_t *acl, const dns_aclelement_t *elt) {
if (acl->length + 1 > acl->alloc) {
/*
* Resize the ACL.
*/
unsigned int newalloc;
void *newmem;
newalloc = acl->alloc * 2;
if (newalloc < 4)
newalloc = 4;
newmem = isc_mem_get(acl->mctx,
newalloc * sizeof(dns_aclelement_t));
if (newmem == NULL)
return (ISC_R_NOMEMORY);
memcpy(newmem, acl->elements,
acl->length * sizeof(dns_aclelement_t));
isc_mem_put(acl->mctx, acl->elements,
acl->alloc * sizeof(dns_aclelement_t));
acl->elements = newmem;
acl->alloc = newalloc;
}
/*
* Append the new element.
*/
acl->elements[acl->length++] = *elt;
return (ISC_R_SUCCESS);
}
static isc_result_t
dns_acl_anyornone(isc_mem_t *mctx, isc_boolean_t neg, dns_acl_t **target) {
isc_result_t result;
dns_acl_t *acl = NULL;
result = dns_acl_create(mctx, 1, &acl);
if (result != ISC_R_SUCCESS)
return (result);
acl->elements[0].negative = neg;
acl->elements[0].type = dns_aclelementtype_any;
acl->length = 1;
*target = acl;
return (result);
}
isc_result_t
dns_acl_any(isc_mem_t *mctx, dns_acl_t **target) {
return (dns_acl_anyornone(mctx, ISC_FALSE, target));
}
isc_result_t
dns_acl_none(isc_mem_t *mctx, dns_acl_t **target) {
return (dns_acl_anyornone(mctx, ISC_TRUE, target));
}
isc_result_t
dns_acl_match(const isc_netaddr_t *reqaddr,
const dns_name_t *reqsigner,
const dns_acl_t *acl,
const dns_aclenv_t *env,
int *match,
dns_aclelement_t const**matchelt)
{
unsigned int i;
REQUIRE(reqaddr != NULL);
REQUIRE(matchelt == NULL || *matchelt == NULL);
for (i = 0; i < acl->length; i++) {
dns_aclelement_t *e = &acl->elements[i];
if (dns_aclelement_match(reqaddr, reqsigner,
e, env, matchelt)) {
*match = e->negative ? -((int)i+1) : ((int)i+1);
return (ISC_R_SUCCESS);
}
}
/* No match. */
*match = 0;
return (ISC_R_SUCCESS);
}
isc_result_t
dns_acl_elementmatch(const dns_acl_t *acl,
const dns_aclelement_t *elt,
const dns_aclelement_t **matchelt)
{
unsigned int i;
REQUIRE(elt != NULL);
REQUIRE(matchelt == NULL || *matchelt == NULL);
for (i = 0; i < acl->length; i++) {
dns_aclelement_t *e = &acl->elements[i];
if (dns_aclelement_equal(e, elt) == ISC_TRUE) {
if (matchelt != NULL)
*matchelt = e;
return (ISC_R_SUCCESS);
}
}
return (ISC_R_NOTFOUND);
}
isc_boolean_t
dns_aclelement_match(const isc_netaddr_t *reqaddr,
const dns_name_t *reqsigner,
const dns_aclelement_t *e,
const dns_aclenv_t *env,
const dns_aclelement_t **matchelt)
{
dns_acl_t *inner = NULL;
const isc_netaddr_t *addr;
isc_netaddr_t v4addr;
int indirectmatch;
isc_result_t result;
switch (e->type) {
case dns_aclelementtype_ipprefix:
if (env == NULL ||
env->match_mapped == ISC_FALSE ||
reqaddr->family != AF_INET6 ||
!IN6_IS_ADDR_V4MAPPED(&reqaddr->type.in6))
addr = reqaddr;
else {
isc_netaddr_fromv4mapped(&v4addr, reqaddr);
addr = &v4addr;
}
if (isc_netaddr_eqprefix(addr,
&e->u.ip_prefix.address,
e->u.ip_prefix.prefixlen))
goto matched;
break;
case dns_aclelementtype_keyname:
if (reqsigner != NULL &&
dns_name_equal(reqsigner, &e->u.keyname))
goto matched;
break;
case dns_aclelementtype_nestedacl:
inner = e->u.nestedacl;
nested:
result = dns_acl_match(reqaddr, reqsigner,
inner,
env,
&indirectmatch, matchelt);
INSIST(result == ISC_R_SUCCESS);
/*
* Treat negative matches in indirect ACLs as
* "no match".
* That way, a negated indirect ACL will never become
* a surprise positive match through double negation.
* XXXDCL this should be documented.
*/
if (indirectmatch > 0)
goto matchelt_set;
/*
* A negative indirect match may have set *matchelt,
* but we don't want it set when we return.
*/
if (matchelt != NULL)
*matchelt = NULL;
break;
case dns_aclelementtype_any:
matched:
if (matchelt != NULL)
*matchelt = e;
matchelt_set:
return (ISC_TRUE);
case dns_aclelementtype_localhost:
if (env != NULL && env->localhost != NULL) {
inner = env->localhost;
goto nested;
} else {
break;
}
case dns_aclelementtype_localnets:
if (env != NULL && env->localnets != NULL) {
inner = env->localnets;
goto nested;
} else {
break;
}
default:
INSIST(0);
break;
}
return (ISC_FALSE);
}
void
dns_acl_attach(dns_acl_t *source, dns_acl_t **target) {
REQUIRE(DNS_ACL_VALID(source));
isc_refcount_increment(&source->refcount, NULL);
*target = source;
}
static void
destroy(dns_acl_t *dacl) {
unsigned int i;
for (i = 0; i < dacl->length; i++) {
dns_aclelement_t *de = &dacl->elements[i];
switch (de->type) {
case dns_aclelementtype_keyname:
dns_name_free(&de->u.keyname, dacl->mctx);
break;
case dns_aclelementtype_nestedacl:
dns_acl_detach(&de->u.nestedacl);
break;
default:
break;
}
}
if (dacl->elements != NULL)
isc_mem_put(dacl->mctx, dacl->elements,
dacl->alloc * sizeof(dns_aclelement_t));
if (dacl->name != NULL)
isc_mem_free(dacl->mctx, dacl->name);
isc_refcount_destroy(&dacl->refcount);
dacl->magic = 0;
isc_mem_put(dacl->mctx, dacl, sizeof(*dacl));
}
void
dns_acl_detach(dns_acl_t **aclp) {
dns_acl_t *acl = *aclp;
unsigned int refs;
REQUIRE(DNS_ACL_VALID(acl));
isc_refcount_decrement(&acl->refcount, &refs);
if (refs == 0)
destroy(acl);
*aclp = NULL;
}
isc_boolean_t
dns_aclelement_equal(const dns_aclelement_t *ea, const dns_aclelement_t *eb) {
if (ea->type != eb->type)
return (ISC_FALSE);
switch (ea->type) {
case dns_aclelementtype_ipprefix:
if (ea->u.ip_prefix.prefixlen !=
eb->u.ip_prefix.prefixlen)
return (ISC_FALSE);
return (isc_netaddr_eqprefix(&ea->u.ip_prefix.address,
&eb->u.ip_prefix.address,
ea->u.ip_prefix.prefixlen));
case dns_aclelementtype_keyname:
return (dns_name_equal(&ea->u.keyname, &eb->u.keyname));
case dns_aclelementtype_nestedacl:
return (dns_acl_equal(ea->u.nestedacl, eb->u.nestedacl));
case dns_aclelementtype_localhost:
case dns_aclelementtype_localnets:
case dns_aclelementtype_any:
return (ISC_TRUE);
default:
INSIST(0);
return (ISC_FALSE);
}
}
isc_boolean_t
dns_acl_equal(const dns_acl_t *a, const dns_acl_t *b) {
unsigned int i;
if (a == b)
return (ISC_TRUE);
if (a->length != b->length)
return (ISC_FALSE);
for (i = 0; i < a->length; i++) {
if (! dns_aclelement_equal(&a->elements[i],
&b->elements[i]))
return (ISC_FALSE);
}
return (ISC_TRUE);
}
static isc_boolean_t
is_loopback(const dns_aclipprefix_t *p) {
switch (p->address.family) {
case AF_INET:
if (p->prefixlen == 32 &&
htonl(p->address.type.in.s_addr) == INADDR_LOOPBACK)
return (ISC_TRUE);
break;
case AF_INET6:
if (p->prefixlen == 128 &&
IN6_IS_ADDR_LOOPBACK(&p->address.type.in6))
return (ISC_TRUE);
break;
default:
break;
}
return (ISC_FALSE);
}
isc_boolean_t
dns_acl_isinsecure(const dns_acl_t *a) {
unsigned int i;
for (i = 0; i < a->length; i++) {
dns_aclelement_t *e = &a->elements[i];
/* A negated match can never be insecure. */
if (e->negative)
continue;
switch (e->type) {
case dns_aclelementtype_ipprefix:
/* The loopback address is considered secure. */
if (! is_loopback(&e->u.ip_prefix))
return (ISC_TRUE);
continue;
case dns_aclelementtype_keyname:
case dns_aclelementtype_localhost:
continue;
case dns_aclelementtype_nestedacl:
if (dns_acl_isinsecure(e->u.nestedacl))
return (ISC_TRUE);
continue;
case dns_aclelementtype_localnets:
case dns_aclelementtype_any:
return (ISC_TRUE);
default:
INSIST(0);
return (ISC_TRUE);
}
}
/* No insecure elements were found. */
return (ISC_FALSE);
}
isc_result_t
dns_aclenv_init(isc_mem_t *mctx, dns_aclenv_t *env) {
isc_result_t result;
env->localhost = NULL;
env->localnets = NULL;
result = dns_acl_create(mctx, 0, &env->localhost);
if (result != ISC_R_SUCCESS)
goto cleanup_nothing;
result = dns_acl_create(mctx, 0, &env->localnets);
if (result != ISC_R_SUCCESS)
goto cleanup_localhost;
env->match_mapped = ISC_FALSE;
return (ISC_R_SUCCESS);
cleanup_localhost:
dns_acl_detach(&env->localhost);
cleanup_nothing:
return (result);
}
void
dns_aclenv_copy(dns_aclenv_t *t, dns_aclenv_t *s) {
dns_acl_detach(&t->localhost);
dns_acl_attach(s->localhost, &t->localhost);
dns_acl_detach(&t->localnets);
dns_acl_attach(s->localnets, &t->localnets);
t->match_mapped = s->match_mapped;
}
void
dns_aclenv_destroy(dns_aclenv_t *env) {
dns_acl_detach(&env->localhost);
dns_acl_detach(&env->localnets);
}
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