view.h

非常好的dns解析软件

/*
 * Copyright (C) 2004-2006  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: view.h,v 1.91.18.9 2006/03/09 23:38:21 marka Exp $ */

#ifndef DNS_VIEW_H
#define DNS_VIEW_H 1

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

/*! \file
 * \brief
 * DNS View
 *
 * A "view" is a DNS namespace, together with an optional resolver and a
 * forwarding policy.  A "DNS namespace" is a (possibly empty) set of
 * authoritative zones together with an optional cache and optional
 * "hints" information.
 *
 * Views start out "unfrozen".  In this state, core attributes like
 * the cache, set of zones, and forwarding policy may be set.  While
 * "unfrozen", the caller (e.g. nameserver configuration loading
 * code), must ensure exclusive access to the view.  When the view is
 * "frozen", the core attributes become immutable, and the view module
 * will ensure synchronization.  Freezing allows the view's core attributes
 * to be accessed without locking.
 *
 * MP:
 *\li	Before the view is frozen, the caller must ensure synchronization.
 *
 *\li	After the view is frozen, the module guarantees appropriate
 *	synchronization of any data structures it creates and manipulates.
 *
 * Reliability:
 *\li	No anticipated impact.
 *
 * Resources:
 *\li	TBS
 *
 * Security:
 *\li	No anticipated impact.
 *
 * Standards:
 *\li	None.
 */

#include <stdio.h>

#include <isc/lang.h>
#include <isc/magic.h>
#include <isc/event.h>
#include <isc/mutex.h>
#include <isc/net.h>
#include <isc/refcount.h>
#include <isc/rwlock.h>
#include <isc/stdtime.h>

#include <dns/acl.h>
#include <dns/fixedname.h>
#include <dns/types.h>

ISC_LANG_BEGINDECLS

struct dns_view {
	/* Unlocked. */
	unsigned int			magic;
	isc_mem_t *			mctx;
	dns_rdataclass_t		rdclass;
	char *				name;
	dns_zt_t *			zonetable;
	dns_dlzdb_t *			dlzdatabase;
	dns_resolver_t *		resolver;
	dns_adb_t *			adb;
	dns_requestmgr_t *		requestmgr;
	dns_acache_t *			acache;
	dns_cache_t *			cache;
	dns_db_t *			cachedb;
	dns_db_t *			hints;
	dns_keytable_t *		secroots;
	dns_keytable_t *		trustedkeys;
	isc_mutex_t			lock;
	isc_boolean_t			frozen;
	isc_task_t *			task;
	isc_event_t			resevent;
	isc_event_t			adbevent;
	isc_event_t			reqevent;
	/* Configurable data. */
	dns_tsig_keyring_t *		statickeys;
	dns_tsig_keyring_t *		dynamickeys;
	dns_peerlist_t *		peers;
	dns_order_t *			order;
	dns_fwdtable_t *		fwdtable;
	isc_boolean_t			recursion;
	isc_boolean_t			auth_nxdomain;
	isc_boolean_t			additionalfromcache;
	isc_boolean_t			additionalfromauth;
	isc_boolean_t			minimalresponses;
	isc_boolean_t			enablednssec;
	isc_boolean_t			enablevalidation;
	isc_boolean_t			acceptexpired;
	dns_transfer_format_t		transfer_format;
	dns_acl_t *			queryacl;
	dns_acl_t *			recursionacl;
	dns_acl_t *			sortlist;
	isc_boolean_t			requestixfr;
	isc_boolean_t			provideixfr;
	dns_ttl_t			maxcachettl;
	dns_ttl_t			maxncachettl;
	in_port_t			dstport;
	dns_aclenv_t			aclenv;
	dns_rdatatype_t			preferred_glue;
	isc_boolean_t			flush;
	dns_namelist_t *		delonly;
	isc_boolean_t			rootdelonly;
	dns_namelist_t *		rootexclude;
	isc_boolean_t			checknames;
	dns_name_t *			dlv;
	dns_fixedname_t			dlv_fixed;
	isc_uint16_t			maxudp;

	/*
	 * Configurable data for server use only,
	 * locked by server configuration lock.
	 */
	dns_acl_t *			matchclients;
	dns_acl_t *			matchdestinations;
	isc_boolean_t			matchrecursiveonly;

	/* Locked by themselves. */
	isc_refcount_t			references;

	/* Locked by lock. */
	unsigned int			weakrefs;
	unsigned int			attributes;
	/* Under owner's locking control. */
	ISC_LINK(struct dns_view)	link;
};

#define DNS_VIEW_MAGIC			ISC_MAGIC('V','i','e','w')
#define DNS_VIEW_VALID(view)		ISC_MAGIC_VALID(view, DNS_VIEW_MAGIC)

#define DNS_VIEWATTR_RESSHUTDOWN	0x01
#define DNS_VIEWATTR_ADBSHUTDOWN	0x02
#define DNS_VIEWATTR_REQSHUTDOWN	0x04

isc_result_t
dns_view_create(isc_mem_t *mctx, dns_rdataclass_t rdclass,
		const char *name, dns_view_t **viewp);
/*%<
 * Create a view.
 *
 * Notes:
 *
 *\li	The newly created view has no cache, no resolver, and an empty
 *	zone table.  The view is not frozen.
 *
 * Requires:
 *
 *\li	'mctx' is a valid memory context.
 *
 *\li	'rdclass' is a valid class.
 *
 *\li	'name' is a valid C string.
 *
 *\li	viewp != NULL && *viewp == NULL
 *
 * Returns:
 *
 *\li	#ISC_R_SUCCESS
 *\li	#ISC_R_NOMEMORY
 *
 *\li	Other errors are possible.
 */

void
dns_view_attach(dns_view_t *source, dns_view_t **targetp);
/*%<
 * Attach '*targetp' to 'source'.
 *
 * Requires:
 *
 *\li	'source' is a valid, frozen view.
 *
 *\li	'targetp' points to a NULL dns_view_t *.
 *
 * Ensures:
 *
 *\li	*targetp is attached to source.
 *
 *\li	While *targetp is attached, the view will not shut down.
 */

void
dns_view_detach(dns_view_t **viewp);
/*%<
 * Detach '*viewp' from its view.
 *
 * Requires:
 *
 *\li	'viewp' points to a valid dns_view_t *
 *
 * Ensures:
 *
 *\li	*viewp is NULL.
 */

void
dns_view_flushanddetach(dns_view_t **viewp);
/*%<
 * Detach '*viewp' from its view.  If this was the last reference
 * uncommited changed in zones will be flushed to disk.
 *
 * Requires:
 *
 *\li	'viewp' points to a valid dns_view_t *
 *
 * Ensures:
 *
 *\li	*viewp is NULL.
 */

void
dns_view_weakattach(dns_view_t *source, dns_view_t **targetp);
/*%<
 * Weakly attach '*targetp' to 'source'.
 *
 * Requires:
 *
 *\li	'source' is a valid, frozen view.
 *
 *\li	'targetp' points to a NULL dns_view_t *.
 *
 * Ensures:
 *
 *\li	*targetp is attached to source.
 *
 * \li	While *targetp is attached, the view will not be freed.
 */

void
dns_view_weakdetach(dns_view_t **targetp);
/*%<
 * Detach '*viewp' from its view.
 *
 * Requires:
 *
 *\li	'viewp' points to a valid dns_view_t *.
 *
 * Ensures:
 *
 *\li	*viewp is NULL.
 */

isc_result_t
dns_view_createresolver(dns_view_t *view,
			isc_taskmgr_t *taskmgr, unsigned int ntasks,
			isc_socketmgr_t *socketmgr,
			isc_timermgr_t *timermgr,
			unsigned int options,
			dns_dispatchmgr_t *dispatchmgr,
			dns_dispatch_t *dispatchv4,
			dns_dispatch_t *dispatchv6);
/*%<
 * Create a resolver and address database for the view.
 *
 * Requires:
 *
 *\li	'view' is a valid, unfrozen view.
 *
 *\li	'view' does not have a resolver already.
 *
 *\li	The requirements of dns_resolver_create() apply to 'taskmgr',
 *	'ntasks', 'socketmgr', 'timermgr', 'options', 'dispatchv4', and
 *	'dispatchv6'.
 *
 * Returns:
 *
 *\li   	#ISC_R_SUCCESS
 *
 *\li	Any error that dns_resolver_create() can return.
 */

void
dns_view_setcache(dns_view_t *view, dns_cache_t *cache);
/*%<
 * Set the view's cache database.
 *
 * Requires:
 *
 *\li	'view' is a valid, unfrozen view.
 *
 *\li	'cache' is a valid cache.
 *
 * Ensures:
 *
 * \li    	The cache of 'view' is 'cached.
 *
 *\li	If this is not the first call to dns_view_setcache() for this
 *	view, then previously set cache is detached.
 */

void
dns_view_sethints(dns_view_t *view, dns_db_t *hints);
/*%<
 * Set the view's hints database.
 *
 * Requires:
 *
 *\li	'view' is a valid, unfrozen view, whose hints database has not been
 *	set.
 *
 *\li	'hints' is a valid zone database.
 *
 * Ensures:
 *
 * \li    	The hints database of 'view' is 'hints'.
 */

void
dns_view_setkeyring(dns_view_t *view, dns_tsig_keyring_t *ring);
/*%<
 * Set the view's static TSIG keys
 *
 * Requires:
 *
 *   \li   'view' is a valid, unfrozen view, whose static TSIG keyring has not
 *	been set.
 *
 *\li      'ring' is a valid TSIG keyring
 *
 * Ensures:
 *
 *\li      The static TSIG keyring of 'view' is 'ring'.
 */

void
dns_view_setdstport(dns_view_t *view, in_port_t dstport);
/*%<
 * Set the view's destination port.  This is the port to
 * which outgoing queries are sent.  The default is 53,
 * the standard DNS port.
 *
 * Requires:
 *
 *\li      'view' is a valid view.
 *
 *\li      'dstport' is a valid TCP/UDP port number.
 *
 * Ensures:
 *\li	External name servers will be assumed to be listning
 *	on 'dstport'.  For servers whose address has already
 *	obtained obtained at the time of the call, the view may
 *	continue to use the previously set port until the address
 *	times out from the view's address database.
 */


isc_result_t
dns_view_addzone(dns_view_t *view, dns_zone_t *zone);
/*%<
 * Add zone 'zone' to 'view'.
 *
 * Requires:
 *
 *\li	'view' is a valid, unfrozen view.
 *
 *\li	'zone' is a valid zone.
 */

void
dns_view_freeze(dns_view_t *view);
/*%<
 * Freeze view.
 *
 * Requires:
 *
 *\li	'view' is a valid, unfrozen view.
 *
 * Ensures:
 *
 *\li	'view' is frozen.
 */

isc_result_t
dns_view_find(dns_view_t *view, dns_name_t *name, dns_rdatatype_t type,
	      isc_stdtime_t now, unsigned int options, isc_boolean_t use_hints,
	      dns_db_t **dbp, dns_dbnode_t **nodep, dns_name_t *foundname,