/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* 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.
*/
#ifndef DNS_ACL_H
#define DNS_ACL_H 1
/*****
***** Module Info
*****/
/*! \file dns/acl.h
* \brief
* Address match list handling.
*/
/***
*** Imports
***/
#include <stdbool.h>
#include <isc/lang.h>
#include <isc/magic.h>
#include <isc/netaddr.h>
#include <isc/refcount.h>
#include <dns/geoip.h>
#include <dns/iptable.h>
#include <dns/name.h>
#include <dns/types.h>
/***
*** Types
***/
typedef enum {
dns_aclelementtype_ipprefix,
dns_aclelementtype_keyname,
dns_aclelementtype_nestedacl,
dns_aclelementtype_localhost,
dns_aclelementtype_localnets,
#if defined(HAVE_GEOIP2)
dns_aclelementtype_geoip,
#endif /* HAVE_GEOIP2 */
dns_aclelementtype_any
} dns_aclelementtype_t;
typedef struct dns_aclipprefix dns_aclipprefix_t;
struct dns_aclipprefix {
isc_netaddr_t address; /* IP4/IP6 */
unsigned int prefixlen;
};
struct dns_aclelement {
dns_aclelementtype_t type;
bool negative;
dns_name_t keyname;
#if defined(HAVE_GEOIP2)
dns_geoip_elem_t geoip_elem;
#endif /* HAVE_GEOIP2 */
dns_acl_t *nestedacl;
int node_num;
};
#define dns_acl_node_count(acl) acl->iptable->radix->num_added_node
struct dns_acl {
unsigned int magic;
isc_mem_t *mctx;
isc_refcount_t refcount;
dns_iptable_t *iptable;
dns_aclelement_t *elements;
bool has_negatives;
unsigned int alloc; /*%< Elements allocated */
unsigned int length; /*%< Elements initialized */
char *name; /*%< Temporary use only */
ISC_LINK(dns_acl_t) nextincache; /*%< Ditto */
};
struct dns_aclenv {
dns_acl_t *localhost;
dns_acl_t *localnets;
bool match_mapped;
#if defined(HAVE_GEOIP2)
dns_geoip_databases_t *geoip;
#endif /* HAVE_GEOIP2 */
};
#define DNS_ACL_MAGIC ISC_MAGIC('D', 'a', 'c', 'l')
#define DNS_ACL_VALID(a) ISC_MAGIC_VALID(a, DNS_ACL_MAGIC)
/***
*** Functions
***/
ISC_LANG_BEGINDECLS
isc_result_t
dns_acl_create(isc_mem_t *mctx, int n, dns_acl_t **target);
/*%<
* Create a new ACL, including an IP table and an array with room
* for 'n' ACL elements. The elements are uninitialized and the
* length is 0.
*/
isc_result_t
dns_acl_any(isc_mem_t *mctx, dns_acl_t **target);
/*%<
* Create a new ACL that matches everything.
*/
isc_result_t
dns_acl_none(isc_mem_t *mctx, dns_acl_t **target);
/*%<
* Create a new ACL that matches nothing.
*/
bool
dns_acl_isany(dns_acl_t *acl);
/*%<
* Test whether ACL is set to "{ any; }"
*/
bool
dns_acl_isnone(dns_acl_t *acl);
/*%<
* Test whether ACL is set to "{ none; }"
*/
isc_result_t
dns_acl_merge(dns_acl_t *dest, dns_acl_t *source, bool pos);
/*%<
* Merge the contents of one ACL into another. Call dns_iptable_merge()
* for the IP tables, then concatenate the element arrays.
*
* If pos is set to false, then the nested ACL is to be negated. This
* means reverse the sense of each *positive* element or IP table node,
* but leave negatives alone, so as to prevent a double-negative causing
* an unexpected positive match in the parent ACL.
*/
void
dns_acl_attach(dns_acl_t *source, dns_acl_t **target);
/*%<
* Attach to acl 'source'.
*
* Requires:
*\li 'source' to be a valid acl.
*\li 'target' to be non NULL and '*target' to be NULL.
*/
void
dns_acl_detach(dns_acl_t **aclp);
/*%<
* Detach the acl. On final detach the acl must not be linked on any
* list.
*
* Requires:
*\li '*aclp' to be a valid acl.
*
* Insists:
*\li '*aclp' is not linked on final detach.
*/
bool
dns_acl_isinsecure(const dns_acl_t *a);
/*%<
* Return #true iff the acl 'a' is considered insecure, that is,
* if it contains IP addresses other than those of the local host.
* This is intended for applications such as printing warning
* messages for suspect ACLs; it is not intended for making access
* control decisions. We make no guarantee that an ACL for which
* this function returns #false is safe.
*/
bool
dns_acl_allowed(isc_netaddr_t *addr, const dns_name_t *signer, dns_acl_t *acl,
dns_aclenv_t *aclenv);
/*%<
* Return #true iff the 'addr', 'signer', or ECS values are
* permitted by 'acl' in environment 'aclenv'.
*/
isc_result_t
dns_aclenv_init(isc_mem_t *mctx, dns_aclenv_t *env);
/*%<
* Initialize ACL environment, setting up localhost and localnets ACLs
*/
void
dns_aclenv_copy(dns_aclenv_t *t, dns_aclenv_t *s);
void
dns_aclenv_destroy(dns_aclenv_t *env);
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,
const dns_aclelement_t **matchelt);
/*%<
* General, low-level ACL matching. This is expected to
* be useful even for weird stuff like the topology and sortlist statements.
*
* Match the address 'reqaddr', and optionally the key name 'reqsigner',
* against 'acl'. 'reqsigner' may be NULL.
*
* If there is a match, '*match' will be set to an integer whose absolute
* value corresponds to the order in which the matching value was inserted
* into the ACL. For a positive match, this value will be positive; for a
* negative match, it will be negative.
*
* If there is no match, *match will be set to zero.
*
* If there is a match in the element list (either positive or negative)
* and 'matchelt' is non-NULL, *matchelt will be pointed to the matching
* element.
*
* 'env' points to the current ACL environment, including the
* current values of localhost and localnets and (if applicable)
* the GeoIP context.
*
* Returns:
*\li #ISC_R_SUCCESS Always succeeds.
*/
bool
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);
/*%<
* Like dns_acl_match, but matches against the single ACL element 'e'
* rather than a complete ACL, and returns true iff it matched.
*
* To determine whether the match was positive or negative, the
* caller should examine e->negative. Since the element 'e' may be
* a reference to a named ACL or a nested ACL, a matching element
* returned through 'matchelt' is not necessarily 'e' itself.
*/
ISC_LANG_ENDDECLS
#endif /* DNS_ACL_H */
