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  $   ˆl–Ãa¾”ji?u@?pÜŠbÑ¿Â„M‰ßÁÀ¿ 8¿    /*
 * 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_CLIENT_H
#define DNS_CLIENT_H 1

/*****
***** Module Info
*****/

/*! \file
 *
 * \brief
 * The DNS client module provides convenient programming interfaces to various
 * DNS services, such as name resolution with or without DNSSEC validation or
 * dynamic DNS update.  This module is primarily expected to be used by other
 * applications than BIND9-related ones that need such advanced DNS features.
 *
 * MP:
 *\li	In the typical usage of this module, application threads will not share
 *	the same data structures created and manipulated in this module.
 *	However, the module still ensures appropriate synchronization of such
 *	data structures.
 *
 * Resources:
 *\li	TBS
 *
 * Security:
 *\li	This module does not handle any low-level data directly, and so no
 *	security issue specific to this module is anticipated.
 */

#include <isc/event.h>
#include <isc/sockaddr.h>

#include <dns/tsig.h>
#include <dns/types.h>

#include <dst/dst.h>

typedef enum {
	updateop_none = 0,
	updateop_add = 1,
	updateop_delete = 2,
	updateop_exist = 3,
	updateop_notexist = 4,
	updateop_max = 5
} dns_client_updateop_t;

ISC_LANG_BEGINDECLS

/***
 *** Types
 ***/

/*%
 * Optional flags for dns_client_create(x).
 */
/*%< Enable caching resolution results (experimental). */
#define DNS_CLIENTCREATEOPT_USECACHE 0x8000

/*%
 * Optional flags for dns_client_(start)resolve.
 */
/*%< Do not return DNSSEC data (e.g. RRSIGS) with response. */
#define DNS_CLIENTRESOPT_NODNSSEC 0x01
/*%< Allow running external context. */
#define DNS_CLIENTRESOPT_RESERVED 0x02
/*%< Don't validate responses. */
#define DNS_CLIENTRESOPT_NOVALIDATE 0x04
/*%< Don't set the CD flag on upstream queries. */
#define DNS_CLIENTRESOPT_NOCDFLAG 0x08
/*%< Use TCP transport. */
#define DNS_CLIENTRESOPT_TCP 0x10

/*%
 * Optional flags for dns_client_(start)request.
 */
/*%< Allow running external context. */
#define DNS_CLIENTREQOPT_RESERVED 0x01
/*%< Use TCP transport. */
#define DNS_CLIENTREQOPT_TCP 0x02

/*%
 * Optional flags for dns_client_(start)update.
 */
/*%< Allow running external context. */
#define DNS_CLIENTUPDOPT_RESERVED 0x01
/*%< Use TCP transport. */
#define DNS_CLIENTUPDOPT_TCP 0x02

/*%
 * View name used in dns_client.
 */
#define DNS_CLIENTVIEW_NAME "_dnsclient"

/*%
 * A dns_clientresevent_t is sent when name resolution performed by a client
 * completes.  'result' stores the result code of the entire resolution
 * procedure.  'vresult' specifically stores the result code of DNSSEC
 * validation if it is performed.  When name resolution successfully completes,
 * 'answerlist' is typically non empty, containing answer names along with
 * RRsets.  It is the receiver's responsibility to free this list by calling
 * dns_client_freeresanswer() before freeing the event structure.
 */
typedef struct dns_clientresevent {
	ISC_EVENT_COMMON(struct dns_clientresevent);
	isc_result_t   result;
	isc_result_t   vresult;
	dns_namelist_t answerlist;
} dns_clientresevent_t; /* too long? */

/*%
 * A dns_clientreqevent_t is sent when a DNS request is completed by a client.
 * 'result' stores the result code of the entire transaction.
 * If the transaction is successfully completed but the response packet cannot
 * be parsed, 'result' will store the result code of dns_message_parse().
 * If the response packet is received, 'rmessage' will contain the response
 * message, whether it is successfully parsed or not.
 */
typedef struct dns_clientreqevent {
	ISC_EVENT_COMMON(struct dns_clientreqevent);
	isc_result_t   result;
	dns_message_t *rmessage;
} dns_clientreqevent_t; /* too long? */

isc_result_t
dns_client_create(isc_mem_t *mctx, isc_