db.h

非常好的dns解析软件

/*
 * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  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: db.h,v 1.76.18.7 2005/10/13 02:12:25 marka Exp $ */

#ifndef DNS_DB_H
#define DNS_DB_H 1

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

/*! \file
 * \brief
 * The DNS DB interface allows named rdatasets to be stored and retrieved.
 *
 * The dns_db_t type is like a "virtual class".  To actually use
 * DBs, an implementation of the class is required.
 *
 * XXX more XXX
 *
 * MP:
 * \li	The module ensures appropriate synchronization of data structures it
 *	creates and manipulates.
 *
 * Reliability:
 * \li	No anticipated impact.
 *
 * Resources:
 * \li	TBS
 *
 * Security:
 * \li	No anticipated impact.
 *
 * Standards:
 * \li	None.
 */

/*****
 ***** Imports
 *****/

#include <isc/lang.h>
#include <isc/magic.h>
#include <isc/ondestroy.h>
#include <isc/stdtime.h>

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

ISC_LANG_BEGINDECLS

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

typedef struct dns_dbmethods {
	void		(*attach)(dns_db_t *source, dns_db_t **targetp);
	void		(*detach)(dns_db_t **dbp);
	isc_result_t	(*beginload)(dns_db_t *db, dns_addrdatasetfunc_t *addp,
				     dns_dbload_t **dbloadp);
	isc_result_t	(*endload)(dns_db_t *db, dns_dbload_t **dbloadp);
	isc_result_t	(*dump)(dns_db_t *db, dns_dbversion_t *version,
				const char *filename,
				dns_masterformat_t masterformat);
	void		(*currentversion)(dns_db_t *db,
					  dns_dbversion_t **versionp);
	isc_result_t	(*newversion)(dns_db_t *db,
				      dns_dbversion_t **versionp);
	void		(*attachversion)(dns_db_t *db, dns_dbversion_t *source,
					 dns_dbversion_t **targetp);
	void		(*closeversion)(dns_db_t *db,
					dns_dbversion_t **versionp,
					isc_boolean_t commit);
	isc_result_t	(*findnode)(dns_db_t *db, dns_name_t *name,
				    isc_boolean_t create,
				    dns_dbnode_t **nodep);
	isc_result_t	(*find)(dns_db_t *db, dns_name_t *name,
				dns_dbversion_t *version,
				dns_rdatatype_t type, unsigned int options,
				isc_stdtime_t now,
				dns_dbnode_t **nodep, dns_name_t *foundname,
				dns_rdataset_t *rdataset,
				dns_rdataset_t *sigrdataset);
	isc_result_t	(*findzonecut)(dns_db_t *db, dns_name_t *name,
				       unsigned int options, isc_stdtime_t now,
				       dns_dbnode_t **nodep,
				       dns_name_t *foundname,
				       dns_rdataset_t *rdataset,
				       dns_rdataset_t *sigrdataset);
	void		(*attachnode)(dns_db_t *db,
				      dns_dbnode_t *source,
				      dns_dbnode_t **targetp);
	void		(*detachnode)(dns_db_t *db,
				      dns_dbnode_t **targetp);
	isc_result_t	(*expirenode)(dns_db_t *db, dns_dbnode_t *node,
				      isc_stdtime_t now);
	void		(*printnode)(dns_db_t *db, dns_dbnode_t *node,
				     FILE *out);
	isc_result_t 	(*createiterator)(dns_db_t *db,
					  isc_boolean_t relative_names,
					  dns_dbiterator_t **iteratorp);
	isc_result_t	(*findrdataset)(dns_db_t *db, dns_dbnode_t *node,
					dns_dbversion_t *version,
					dns_rdatatype_t type,
					dns_rdatatype_t covers,
					isc_stdtime_t now,
					dns_rdataset_t *rdataset,
					dns_rdataset_t *sigrdataset);
	isc_result_t	(*allrdatasets)(dns_db_t *db, dns_dbnode_t *node,
					dns_dbversion_t *version,
					isc_stdtime_t now,
					dns_rdatasetiter_t **iteratorp);
	isc_result_t	(*addrdataset)(dns_db_t *db, dns_dbnode_t *node,
				       dns_dbversion_t *version,
				       isc_stdtime_t now,
				       dns_rdataset_t *rdataset,
				       unsigned int options,
				       dns_rdataset_t *addedrdataset);
	isc_result_t	(*subtractrdataset)(dns_db_t *db, dns_dbnode_t *node,
					    dns_dbversion_t *version,
					    dns_rdataset_t *rdataset,
					    unsigned int options,
					    dns_rdataset_t *newrdataset);
	isc_result_t	(*deleterdataset)(dns_db_t *db, dns_dbnode_t *node,
					  dns_dbversion_t *version,
					  dns_rdatatype_t type,
					  dns_rdatatype_t covers);
	isc_boolean_t	(*issecure)(dns_db_t *db);
	unsigned int	(*nodecount)(dns_db_t *db);
	isc_boolean_t	(*ispersistent)(dns_db_t *db);
	void		(*overmem)(dns_db_t *db, isc_boolean_t overmem);
	void		(*settask)(dns_db_t *db, isc_task_t *);
	isc_result_t	(*getoriginnode)(dns_db_t *db, dns_dbnode_t **nodep);
} dns_dbmethods_t;

typedef isc_result_t
(*dns_dbcreatefunc_t)(isc_mem_t *mctx, dns_name_t *name,
		      dns_dbtype_t type, dns_rdataclass_t rdclass,
		      unsigned int argc, char *argv[], void *driverarg,
		      dns_db_t **dbp);
					
#define DNS_DB_MAGIC		ISC_MAGIC('D','N','S','D')
#define DNS_DB_VALID(db)	ISC_MAGIC_VALID(db, DNS_DB_MAGIC)

/*%
 * This structure is actually just the common prefix of a DNS db
 * implementation's version of a dns_db_t.
 * \brief
 * Direct use of this structure by clients is forbidden.  DB implementations
 * may change the structure.  'magic' must be DNS_DB_MAGIC for any of the
 * dns_db_ routines to work.  DB implementations must maintain all DB
 * invariants.
 */
struct dns_db {
	unsigned int			magic;
	unsigned int			impmagic;
	dns_dbmethods_t *		methods;
	isc_uint16_t			attributes;
	dns_rdataclass_t		rdclass;
	dns_name_t			origin;
	isc_ondestroy_t			ondest;
	isc_mem_t *			mctx;
};

#define DNS_DBATTR_CACHE		0x01
#define DNS_DBATTR_STUB			0x02

/*@{*/
/*%
 * Options that can be specified for dns_db_find().
 */
#define DNS_DBFIND_GLUEOK		0x01
#define DNS_DBFIND_VALIDATEGLUE		0x02
#define DNS_DBFIND_NOWILD		0x04
#define DNS_DBFIND_PENDINGOK		0x08
#define DNS_DBFIND_NOEXACT		0x10
#define DNS_DBFIND_FORCENSEC		0x20
#define DNS_DBFIND_COVERINGNSEC		0x40
/*@}*/

/*@{*/
/*%
 * Options that can be specified for dns_db_addrdataset().
 */
#define DNS_DBADD_MERGE			0x01
#define DNS_DBADD_FORCE			0x02
#define DNS_DBADD_EXACT			0x04
#define DNS_DBADD_EXACTTTL		0x08
/*@}*/

/*%
 * Options that can be specified for dns_db_subtractrdataset().
 */
#define DNS_DBSUB_EXACT			0x01

/*****
 ***** Methods
 *****/

/***
 *** Basic DB Methods
 ***/

isc_result_t
dns_db_create(isc_mem_t *mctx, const char *db_type, dns_name_t *origin,
	      dns_dbtype_t type, dns_rdataclass_t rdclass,
	      unsigned int argc, char *argv[], dns_db_t **dbp);
/*%<
 * Create a new database using implementation 'db_type'.
 *
 * Notes:
 * \li	All names in the database must be subdomains of 'origin' and in class
 *	'rdclass'.  The database makes its own copy of the origin, so the
 *	caller may do whatever they like with 'origin' and its storage once the
 *	call returns.
 *
 * \li	DB implementation-specific parameters are passed using argc and argv.
 *
 * Requires:
 *
 * \li	dbp != NULL and *dbp == NULL
 *
 * \li	'origin' is a valid absolute domain name.
 *
 * \li	mctx is a valid memory context
 *
 * Ensures:
 *
 * \li	A copy of 'origin' has been made for the databases use, and the
 *	caller is free to do whatever they want with the name and storage
 *	associated with 'origin'.
 *
 * Returns:
 *
 * \li	#ISC_R_SUCCESS
 * \li	#ISC_R_NOMEMORY
 * \li	#ISC_R_NOTFOUND				db_type not found
 *
 * \li	Many other errors are possible, depending on what db_type was
 *	specified.
 */

void
dns_db_attach(dns_db_t *source, dns_db_t **targetp);
/*%<
 * Attach *targetp to source.
 *
 * Requires:
 *
 * \li	'source' is a valid database.
 *
 * \li	'targetp' points to a NULL dns_db_t *.
 *
 * Ensures:
 *
 * \li	*targetp is attached to source.
 */

void
dns_db_detach(dns_db_t **dbp);
/*%<
 * Detach *dbp from its database.
 *
 * Requires:
 *
 * \li	'dbp' points to a valid database.
 *
 * Ensures:
 *
 * \li	*dbp is NULL.
 *
 * \li	If '*dbp' is the last reference to the database,
 *		all resources used by the database will be freed
 */

isc_result_t
dns_db_ondestroy(dns_db_t *db, isc_task_t *task, isc_event_t **eventp);
/*%<
 * Causes 'eventp' to be sent to be sent to 'task' when the database is
 * destroyed.
 *
 * Note; ownership of the eventp is taken from the caller (and *eventp is
 * set to NULL). The sender field of the event is set to 'db' before it is
 * sent to the task.
 */

isc_boolean_t
dns_db_iscache(dns_db_t *db);
/*%<
 * Does 'db' have cache semantics?
 *
 * Requires:
 *
 * \li	'db' is a valid database.
 *
 * Returns:
 * \li	#ISC_TRUE	'db' has cache semantics
 * \li	#ISC_FALSE	otherwise
 */

isc_boolean_t
dns_db_iszone(dns_db_t *db);
/*%<
 * Does 'db' have zone semantics?
 *
 * Requires:
 *
 * \li	'db' is a valid database.
 *
 * Returns:
 * \li	#ISC_TRUE	'db' has zone semantics
 * \li	#ISC_FALSE	otherwise
 */

isc_boolean_t
dns_db_isstub(dns_db_t *db);
/*%<
 * Does 'db' have stub semantics?
 *
 * Requires:
 *
 * \li	'db' is a valid database.
 *
 * Returns:
 * \li	#ISC_TRUE	'db' has zone semantics
 * \li	#ISC_FALSE	otherwise
 */

isc_boolean_t
dns_db_issecure(dns_db_t *db);
/*%<
 * Is 'db' secure?
 *
 * Requires:
 *
 * \li	'db' is a valid database with zone semantics.
 *
 * Returns:
 * \li	#ISC_TRUE	'db' is secure.
 * \li	#ISC_FALSE	'db' is not secure.
 */

dns_name_t *
dns_db_origin(dns_db_t *db);
/*%<
 * The origin of the database.
 *
 * Note: caller must not try to change this name.
 *
 * Requires:
 *
 * \li	'db' is a valid database.
 *
 * Returns:
 *
 * \li	The origin of the database.
 */

dns_rdataclass_t
dns_db_class(dns_db_t *db);
/*%<
 * The class of the database.
 *
 * Requires:
 *
 * \li	'db' is a valid database.
 *
 * Returns:
 *
 * \li	The class of the database.
 */

isc_result_t
dns_db_beginload(dns_db_t *db, dns_addrdatasetfunc_t *addp,
		 dns_dbload_t **dbloadp);
/*%<
 * Begin loading 'db'.
 *
 * Requires:
 *
 * \li	'db' is a valid database.
 *
 * \li	This is the first attempt to load 'db'.
 *
 * \li	addp != NULL && *addp == NULL
 *
 * \li	dbloadp != NULL && *dbloadp == NULL
 *
 * Ensures:
 *
 * \li	On success, *addp will be a valid dns_addrdatasetfunc_t suitable
 *	for loading 'db'.  *dbloadp will be a valid DB load context which
 *	should be used as 'arg' when *addp is called.
 *
 * Returns:
 *
 * \li	#ISC_R_SUCCESS
 * \li	#ISC_R_NOMEMORY
 *
 * \li	Other results are possible, depending upon the database
 *	implementation used, syntax errors in the master file, etc.
 */

isc_result_t
dns_db_endload(dns_db_t *db, dns_dbload_t **dbloadp);
/*%<
 * Finish loading 'db'.
 *
 * Requires:
 *
 * \li	'db' is a valid database that is being loaded.
 *
 * \li	dbloadp != NULL and *dbloadp is a valid database load context.
 *
 * Ensures:
 *
 * \li	*dbloadp == NULL
 *
 * Returns: