view.c

bind 9.3结合mysql数据库

/*
 * Copyright (C) 2004  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.c,v 1.103.2.5.2.14 2004/03/10 02:55:58 marka Exp $ */

#include <config.h>

#include <isc/hash.h>
#include <isc/task.h>
#include <isc/string.h>		/* Required for HP/UX (and others?) */
#include <isc/util.h>

#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/cache.h>
#include <dns/db.h>
#include <dns/events.h>
#include <dns/forward.h>
#include <dns/keytable.h>
#include <dns/master.h>
#include <dns/masterdump.h>
#include <dns/order.h>
#include <dns/peer.h>
#include <dns/rdataset.h>
#include <dns/request.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/tsig.h>
#include <dns/zone.h>
#include <dns/zt.h>

#define RESSHUTDOWN(v)	(((v)->attributes & DNS_VIEWATTR_RESSHUTDOWN) != 0)
#define ADBSHUTDOWN(v)	(((v)->attributes & DNS_VIEWATTR_ADBSHUTDOWN) != 0)
#define REQSHUTDOWN(v)	(((v)->attributes & DNS_VIEWATTR_REQSHUTDOWN) != 0)

#define DNS_VIEW_DELONLYHASH 111

static void resolver_shutdown(isc_task_t *task, isc_event_t *event);
static void adb_shutdown(isc_task_t *task, isc_event_t *event);
static void req_shutdown(isc_task_t *task, isc_event_t *event);

isc_result_t
dns_view_create(isc_mem_t *mctx, dns_rdataclass_t rdclass,
		const char *name, dns_view_t **viewp)
{
	dns_view_t *view;
	isc_result_t result;

	/*
	 * Create a view.
	 */

	REQUIRE(name != NULL);
	REQUIRE(viewp != NULL && *viewp == NULL);

	view = isc_mem_get(mctx, sizeof(*view));
	if (view == NULL)
		return (ISC_R_NOMEMORY);
	view->name = isc_mem_strdup(mctx, name);
	if (view->name == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup_view;
	}
	result = isc_mutex_init(&view->lock);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_mutex_init() failed: %s",
				 isc_result_totext(result));
		result = ISC_R_UNEXPECTED;
		goto cleanup_name;
	}
	view->zonetable = NULL;
	result = dns_zt_create(mctx, rdclass, &view->zonetable);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "dns_zt_create() failed: %s",
				 isc_result_totext(result));
		result = ISC_R_UNEXPECTED;
		goto cleanup_mutex;
	}
	view->secroots = NULL;
	result = dns_keytable_create(mctx, &view->secroots);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "dns_keytable_create() failed: %s",
				 isc_result_totext(result));
		result = ISC_R_UNEXPECTED;
		goto cleanup_zt;
	}
	view->trustedkeys = NULL;
	result = dns_keytable_create(mctx, &view->trustedkeys);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "dns_keytable_create() failed: %s",
				 isc_result_totext(result));
		result = ISC_R_UNEXPECTED;
		goto cleanup_secroots;
	}
	view->fwdtable = NULL;
	result = dns_fwdtable_create(mctx, &view->fwdtable);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "dns_fwdtable_create() failed: %s",
				 isc_result_totext(result));
		result = ISC_R_UNEXPECTED;
		goto cleanup_trustedkeys;
	}

	view->cache = NULL;
	view->cachedb = NULL;
	view->hints = NULL;
	view->resolver = NULL;
	view->adb = NULL;
	view->requestmgr = NULL;
	view->mctx = mctx;
	view->rdclass = rdclass;
	view->frozen = ISC_FALSE;
	view->task = NULL;
	isc_refcount_init(&view->references, 1);
	view->weakrefs = 0;
	view->attributes = (DNS_VIEWATTR_RESSHUTDOWN|DNS_VIEWATTR_ADBSHUTDOWN|
			    DNS_VIEWATTR_REQSHUTDOWN);
	view->statickeys = NULL;
	view->dynamickeys = NULL;
	view->matchclients = NULL;
	view->matchdestinations = NULL;
	view->matchrecursiveonly = ISC_FALSE;
	result = dns_tsigkeyring_create(view->mctx, &view->dynamickeys);
	if (result != ISC_R_SUCCESS)
		goto cleanup_fwdtable;
	view->peers = NULL;
	view->order = NULL;
	view->delonly = NULL;
	view->rootdelonly = ISC_FALSE;
	view->rootexclude = NULL;

	/*
	 * Initialize configuration data with default values.
	 */
	view->recursion = ISC_TRUE;
	view->auth_nxdomain = ISC_FALSE; /* Was true in BIND 8 */
	view->additionalfromcache = ISC_TRUE;
	view->additionalfromauth = ISC_TRUE;
	view->enablednssec = ISC_TRUE;
	view->minimalresponses = ISC_FALSE;
	view->transfer_format = dns_one_answer;
	view->queryacl = NULL;
	view->recursionacl = NULL;
	view->sortlist = NULL;
	view->requestixfr = ISC_TRUE;
	view->provideixfr = ISC_TRUE;
	view->maxcachettl = 7 * 24 * 3600;
	view->maxncachettl = 3 * 3600;
	view->dstport = 53;
	view->preferred_glue = 0;
	view->flush = ISC_FALSE;
	view->dlv = NULL;
	dns_fixedname_init(&view->dlv_fixed);

	result = dns_order_create(view->mctx, &view->order);
	if (result != ISC_R_SUCCESS)
		goto cleanup_dynkeys;

	result = dns_peerlist_new(view->mctx, &view->peers);
	if (result != ISC_R_SUCCESS)
		goto cleanup_order;

	result = dns_aclenv_init(view->mctx, &view->aclenv);
	if (result != ISC_R_SUCCESS)
		goto cleanup_peerlist;

	ISC_LINK_INIT(view, link);
	ISC_EVENT_INIT(&view->resevent, sizeof(view->resevent), 0, NULL,
		       DNS_EVENT_VIEWRESSHUTDOWN, resolver_shutdown,
		       view, NULL, NULL, NULL);
	ISC_EVENT_INIT(&view->adbevent, sizeof(view->adbevent), 0, NULL,
		       DNS_EVENT_VIEWADBSHUTDOWN, adb_shutdown,
		       view, NULL, NULL, NULL);
	ISC_EVENT_INIT(&view->reqevent, sizeof(view->reqevent), 0, NULL,
		       DNS_EVENT_VIEWREQSHUTDOWN, req_shutdown,
		       view, NULL, NULL, NULL);
	view->magic = DNS_VIEW_MAGIC;

	*viewp = view;

	return (ISC_R_SUCCESS);

 cleanup_peerlist:
	dns_peerlist_detach(&view->peers);

 cleanup_order:
	dns_order_detach(&view->order);

 cleanup_dynkeys:
	dns_tsigkeyring_destroy(&view->dynamickeys);

 cleanup_fwdtable:
	dns_fwdtable_destroy(&view->fwdtable);

 cleanup_trustedkeys:
	dns_keytable_detach(&view->trustedkeys);

 cleanup_secroots:
	dns_keytable_detach(&view->secroots);

 cleanup_zt:
	dns_zt_detach(&view->zonetable);

 cleanup_mutex:
	DESTROYLOCK(&view->lock);

 cleanup_name:
	isc_mem_free(mctx, view->name);

 cleanup_view:
	isc_mem_put(mctx, view, sizeof(*view));

	return (result);
}

static inline void
destroy(dns_view_t *view) {
	REQUIRE(!ISC_LINK_LINKED(view, link));
	REQUIRE(isc_refcount_current(&view->references) == 0);
	REQUIRE(view->weakrefs == 0);
	REQUIRE(RESSHUTDOWN(view));
	REQUIRE(ADBSHUTDOWN(view));
	REQUIRE(REQSHUTDOWN(view));

	if (view->order != NULL)
		dns_order_detach(&view->order);
	if (view->peers != NULL)
		dns_peerlist_detach(&view->peers);
	if (view->dynamickeys != NULL)
		dns_tsigkeyring_destroy(&view->dynamickeys);
	if (view->statickeys != NULL)
		dns_tsigkeyring_destroy(&view->statickeys);
	if (view->adb != NULL)
		dns_adb_detach(&view->adb);
	if (view->resolver != NULL)
		dns_resolver_detach(&view->resolver);
	if (view->requestmgr != NULL)
		dns_requestmgr_detach(&view->requestmgr);
	if (view->task != NULL)
		isc_task_detach(&view->task);
	if (view->hints != NULL)
		dns_db_detach(&view->hints);
	if (view->cachedb != NULL)
		dns_db_detach(&view->cachedb);
	if (view->cache != NULL)
		dns_cache_detach(&view->cache);
	if (view->matchclients != NULL)
		dns_acl_detach(&view->matchclients);
	if (view->matchdestinations != NULL)
		dns_acl_detach(&view->matchdestinations);
	if (view->queryacl != NULL)
		dns_acl_detach(&view->queryacl);
	if (view->recursionacl != NULL)
		dns_acl_detach(&view->recursionacl);
	if (view->sortlist != NULL)
		dns_acl_detach(&view->sortlist);
	if (view->delonly != NULL) {
		dns_name_t *name;
		int i;

		for (i = 0; i < DNS_VIEW_DELONLYHASH; i++) {
			name = ISC_LIST_HEAD(view->delonly[i]);
			while (name != NULL) {
				ISC_LIST_UNLINK(view->delonly[i], name, link);
				dns_name_free(name, view->mctx);
				isc_mem_put(view->mctx, name, sizeof(*name));
				name = ISC_LIST_HEAD(view->delonly[i]);
			}
		}
		isc_mem_put(view->mctx, view->delonly, sizeof(dns_namelist_t) *
			    DNS_VIEW_DELONLYHASH);
		view->delonly = NULL;
	}
	if (view->rootexclude != NULL) {
		dns_name_t *name;
		int i;

		for (i = 0; i < DNS_VIEW_DELONLYHASH; i++) {
			name = ISC_LIST_HEAD(view->rootexclude[i]);
			while (name != NULL) {
				ISC_LIST_UNLINK(view->rootexclude[i],
					 	name, link);
				dns_name_free(name, view->mctx);
				isc_mem_put(view->mctx, name, sizeof(*name));
				name = ISC_LIST_HEAD(view->rootexclude[i]);
			}
		}
		isc_mem_put(view->mctx, view->rootexclude,
			    sizeof(dns_namelist_t) * DNS_VIEW_DELONLYHASH);
		view->rootexclude = NULL;
	}
	dns_keytable_detach(&view->trustedkeys);
	dns_keytable_detach(&view->secroots);
	dns_fwdtable_destroy(&view->fwdtable);
	dns_aclenv_destroy(&view->aclenv);
	DESTROYLOCK(&view->lock);
	isc_refcount_destroy(&view->references);
	isc_mem_free(view->mctx, view->name);
	isc_mem_put(view->mctx, view, sizeof(*view));
}

/*
 * Return true iff 'view' may be freed.
 * The caller must be holding the view lock.
 */
static isc_boolean_t
all_done(dns_view_t *view) {

	if (isc_refcount_current(&view->references) == 0 &&
	    view->weakrefs == 0 &&
	    RESSHUTDOWN(view) && ADBSHUTDOWN(view) && REQSHUTDOWN(view))
		return (ISC_TRUE);

	return (ISC_FALSE);
}

void
dns_view_attach(dns_view_t *source, dns_view_t **targetp) {

	REQUIRE(DNS_VIEW_VALID(source));
	REQUIRE(targetp != NULL && *targetp == NULL);

	isc_refcount_increment(&source->references, NULL);

	*targetp = source;
}

static void
view_flushanddetach(dns_view_t **viewp, isc_boolean_t flush) {
	dns_view_t *view;
	unsigned int refs;
	isc_boolean_t done = ISC_FALSE;

	REQUIRE(viewp != NULL);
	view = *viewp;
	REQUIRE(DNS_VIEW_VALID(view));

	if (flush)
		view->flush = ISC_TRUE;
	isc_refcount_decrement(&view->references, &refs);
	if (refs == 0) {
		LOCK(&view->lock);
		if (!RESSHUTDOWN(view))
			dns_resolver_shutdown(view->resolver);
		if (!ADBSHUTDOWN(view))
			dns_adb_shutdown(view->adb);
		if (!REQSHUTDOWN(view))
			dns_requestmgr_shutdown(view->requestmgr);
		if (view->flush)
			dns_zt_flushanddetach(&view->zonetable);
		else
			dns_zt_detach(&view->zonetable);
		done = all_done(view);
		UNLOCK(&view->lock);
	}

	*viewp = NULL;

	if (done)
		destroy(view);
}

void
dns_view_flushanddetach(dns_view_t **viewp) {
	view_flushanddetach(viewp, ISC_TRUE);
}

void
dns_view_detach(dns_view_t **viewp) {
	view_flushanddetach(viewp, ISC_FALSE);
}

static isc_result_t
dialup(dns_zone_t *zone, void *dummy) {
	UNUSED(dummy);
	dns_zone_dialup(zone);
	return (ISC_R_SUCCESS);
}

void
dns_view_dialup(dns_view_t *view) {
	REQUIRE(DNS_VIEW_VALID(view));
	(void)dns_zt_apply(view->zonetable, ISC_FALSE, dialup, NULL);
}

void
dns_view_weakattach(dns_view_t *source, dns_view_t **targetp) {

	REQUIRE(DNS_VIEW_VALID(source));
	REQUIRE(targetp != NULL && *targetp == NULL);

	LOCK(&source->lock);
	source->weakrefs++;
	UNLOCK(&source->lock);

	*targetp = source;
}

void
dns_view_weakdetach(dns_view_t **viewp) {
	dns_view_t *view;
	isc_boolean_t done = ISC_FALSE;

	REQUIRE(viewp != NULL);
	view = *viewp;
	REQUIRE(DNS_VIEW_VALID(view));

	LOCK(&view->lock);

	INSIST(view->weakrefs > 0);
	view->weakrefs--;
	done = all_done(view);

	UNLOCK(&view->lock);

	*viewp = NULL;

	if (done)
		destroy(view);
}

static void
resolver_shutdown(isc_task_t *task, isc_event_t *event) {
	dns_view_t *view = event->ev_arg;
	isc_boolean_t done;