adb.c

bind 9.3结合mysql数据库

		goto fail0c;

	result = isc_mutex_init(&adb->reflock);
	if (result != ISC_R_SUCCESS)
		goto fail0d;

	/*
	 * Initialize the bucket locks for names and elements.
	 * May as well initialize the list heads, too.
	 */
	result = isc_mutexblock_init(adb->namelocks, NBUCKETS);
	if (result != ISC_R_SUCCESS)
		goto fail1;
	for (i = 0; i < NBUCKETS; i++) {
		ISC_LIST_INIT(adb->names[i]);
		adb->name_sd[i] = ISC_FALSE;
		adb->name_refcnt[i] = 0;
		adb->irefcnt++;
	}
	for (i = 0; i < NBUCKETS; i++) {
		ISC_LIST_INIT(adb->entries[i]);
		adb->entry_sd[i] = ISC_FALSE;
		adb->entry_refcnt[i] = 0;
		adb->irefcnt++;
	}
	result = isc_mutexblock_init(adb->entrylocks, NBUCKETS);
	if (result != ISC_R_SUCCESS)
		goto fail2;

	/*
	 * Memory pools
	 */
#define MPINIT(t, p, n) do { \
	result = isc_mempool_create(mem, sizeof(t), &(p)); \
	if (result != ISC_R_SUCCESS) \
		goto fail3; \
	isc_mempool_setfreemax((p), FREE_ITEMS); \
	isc_mempool_setfillcount((p), FILL_COUNT); \
	isc_mempool_setname((p), n); \
	isc_mempool_associatelock((p), &adb->mplock); \
} while (0)

	MPINIT(dns_adbname_t, adb->nmp, "adbname");
	MPINIT(dns_adbnamehook_t, adb->nhmp, "adbnamehook");
	MPINIT(dns_adbzoneinfo_t, adb->zimp, "adbzoneinfo");
	MPINIT(dns_adbentry_t, adb->emp, "adbentry");
	MPINIT(dns_adbfind_t, adb->ahmp, "adbfind");
	MPINIT(dns_adbaddrinfo_t, adb->aimp, "adbaddrinfo");
	MPINIT(dns_adbfetch_t, adb->afmp, "adbfetch");

#undef MPINIT

	/*
	 * Allocate a timer and a task for our periodic cleanup.
	 */
	result = isc_task_create(adb->taskmgr, 0, &adb->task);
	if (result != ISC_R_SUCCESS)
		goto fail3;
	isc_task_setname(adb->task, "ADB", adb);
	/*
	 * XXXMLG When this is changed to be a config file option,
	 */
	isc_interval_set(&adb->tick_interval, CLEAN_SECONDS, 0);
	result = isc_timer_create(adb->timermgr, isc_timertype_once,
				  NULL, &adb->tick_interval, adb->task,
				  timer_cleanup, adb, &adb->timer);
	if (result != ISC_R_SUCCESS)
		goto fail3;

	DP(ISC_LOG_DEBUG(5), "cleaning interval for adb: "
	   "%u buckets every %u seconds, %u buckets in system, %u cl.interval",
	   CLEAN_BUCKETS, CLEAN_SECONDS, NBUCKETS, CLEAN_PERIOD);

	/*
	 * Normal return.
	 */
	adb->magic = DNS_ADB_MAGIC;
	*newadb = adb;
	return (ISC_R_SUCCESS);

 fail3:
	if (adb->task != NULL)
		isc_task_detach(&adb->task);
	if (adb->timer != NULL)
		isc_timer_detach(&adb->timer);

	/* clean up entrylocks */
	DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS);

 fail2: /* clean up namelocks */
	DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS);

 fail1: /* clean up only allocated memory */
	if (adb->nmp != NULL)
		isc_mempool_destroy(&adb->nmp);
	if (adb->nhmp != NULL)
		isc_mempool_destroy(&adb->nhmp);
	if (adb->zimp != NULL)
		isc_mempool_destroy(&adb->zimp);
	if (adb->emp != NULL)
		isc_mempool_destroy(&adb->emp);
	if (adb->ahmp != NULL)
		isc_mempool_destroy(&adb->ahmp);
	if (adb->aimp != NULL)
		isc_mempool_destroy(&adb->aimp);
	if (adb->afmp != NULL)
		isc_mempool_destroy(&adb->afmp);

	DESTROYLOCK(&adb->reflock);
 fail0d:
	DESTROYLOCK(&adb->mplock);
 fail0c:
	DESTROYLOCK(&adb->lock);
 fail0b:
	isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));

	return (result);
}

void
dns_adb_attach(dns_adb_t *adb, dns_adb_t **adbx) {

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(adbx != NULL && *adbx == NULL);

	inc_adb_erefcnt(adb);
	*adbx = adb;
}

void
dns_adb_detach(dns_adb_t **adbx) {
	dns_adb_t *adb;
	isc_boolean_t need_exit_check;

	REQUIRE(adbx != NULL && DNS_ADB_VALID(*adbx));

	adb = *adbx;
	*adbx = NULL;

	INSIST(adb->erefcnt > 0);

	LOCK(&adb->reflock);
	adb->erefcnt--;
	need_exit_check = ISC_TF(adb->erefcnt == 0 && adb->irefcnt == 0);
	UNLOCK(&adb->reflock);

	if (need_exit_check) {
		LOCK(&adb->lock);
		INSIST(adb->shutting_down);
		check_exit(adb);
		UNLOCK(&adb->lock);
	}
}

void
dns_adb_whenshutdown(dns_adb_t *adb, isc_task_t *task, isc_event_t **eventp) {
	isc_task_t *clone;
	isc_event_t *event;
	isc_boolean_t zeroirefcnt = ISC_FALSE;

	/*
	 * Send '*eventp' to 'task' when 'adb' has shutdown.
	 */

	REQUIRE(DNS_ADB_VALID(adb));
	REQUIRE(eventp != NULL);

	event = *eventp;
	*eventp = NULL;

	LOCK(&adb->lock);

	LOCK(&adb->reflock);
	zeroirefcnt = ISC_TF(adb->irefcnt == 0);

	if (adb->shutting_down && zeroirefcnt &&
	    isc_mempool_getallocated(adb->ahmp) == 0) {
		/*
		 * We're already shutdown.  Send the event.
		 */
		event->ev_sender = adb;
		isc_task_send(task, &event);
	} else {
		clone = NULL;
		isc_task_attach(task, &clone);
		event->ev_sender = clone;
		ISC_LIST_APPEND(adb->whenshutdown, event, ev_link);
	}

	UNLOCK(&adb->reflock);
	UNLOCK(&adb->lock);
}

void
dns_adb_shutdown(dns_adb_t *adb) {
	isc_boolean_t need_check_exit;

	/*
	 * Shutdown 'adb'.
	 */

	LOCK(&adb->lock);

	if (!adb->shutting_down) {
		adb->shutting_down = ISC_TRUE;
		isc_mem_setwater(adb->mctx, water, adb, 0, 0);
		need_check_exit = shutdown_names(adb);
		if (!need_check_exit)
			need_check_exit = shutdown_entries(adb);
		if (need_check_exit)
			check_exit(adb);
	}

	UNLOCK(&adb->lock);
}

isc_result_t
dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
		   void *arg, dns_name_t *name, dns_name_t *zone,
		   unsigned int options, isc_stdtime_t now, dns_name_t *target,
		   in_port_t port, dns_adbfind_t **findp)
{
	dns_adbfind_t *find;
	dns_adbname_t *adbname;
	int bucket;
	isc_boolean_t want_event, start_at_zone, alias, have_address;
	isc_result_t result;
	unsigned int wanted_addresses;
	unsigned int wanted_fetches;
	unsigned int query_pending;

	REQUIRE(DNS_ADB_VALID(adb));
	if (task != NULL) {
		REQUIRE(action != NULL);
	}
	REQUIRE(name != NULL);
	REQUIRE(zone != NULL);
	REQUIRE(findp != NULL && *findp == NULL);
	REQUIRE(target == NULL || dns_name_hasbuffer(target));

	REQUIRE((options & DNS_ADBFIND_ADDRESSMASK) != 0);

	result = ISC_R_UNEXPECTED;
	wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK);
	wanted_fetches = 0;
	query_pending = 0;
	want_event = ISC_FALSE;
	start_at_zone = ISC_FALSE;
	alias = ISC_FALSE;

	if (now == 0)
		isc_stdtime_get(&now);

	/*
	 * XXXMLG  Move this comment somewhere else!
	 *
	 * Look up the name in our internal database.
	 *
	 * Possibilities:  Note that these are not always exclusive.
	 *
	 *	No name found.  In this case, allocate a new name header and
	 *	an initial namehook or two.  If any of these allocations
	 *	fail, clean up and return ISC_R_NOMEMORY.
	 *
	 *	Name found, valid addresses present.  Allocate one addrinfo
	 *	structure for each found and append it to the linked list
	 *	of addresses for this header.
	 *
	 *	Name found, queries pending.  In this case, if a task was
	 *	passed in, allocate a job id, attach it to the name's job
	 *	list and remember to tell the caller that there will be
	 *	more info coming later.
	 */

	find = new_adbfind(adb);
	if (find == NULL)
		return (ISC_R_NOMEMORY);

	find->port = port;

	/*
	 * Remember what types of addresses we are interested in.
	 */
	find->options = options;
	find->flags |= wanted_addresses;
	if (FIND_WANTEVENT(find)) {
		REQUIRE(task != NULL);
	}

	/*
	 * Try to see if we know anything about this name at all.
	 */
	bucket = DNS_ADB_INVALIDBUCKET;
	adbname = find_name_and_lock(adb, name, find->options, &bucket);
	if (adb->name_sd[bucket]) {
		DP(DEF_LEVEL,
		   "dns_adb_createfind: returning ISC_R_SHUTTINGDOWN");
		RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE);
		result = ISC_R_SHUTTINGDOWN;
		goto out;
	}

	/*
	 * Nothing found.  Allocate a new adbname structure for this name.
	 */
	if (adbname == NULL) {
		adbname = new_adbname(adb, name);
		if (adbname == NULL) {
			RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE);
			result = ISC_R_NOMEMORY;
			goto out;
		}
		link_name(adb, bucket, adbname);
		if (FIND_HINTOK(find))
			adbname->flags |= NAME_HINT_OK;
		if (FIND_GLUEOK(find))
			adbname->flags |= NAME_GLUE_OK;
		if (FIND_STARTATZONE(find))
			adbname->flags |= NAME_STARTATZONE;
	}

	/*
	 * Expire old entries, etc.
	 */
	RUNTIME_CHECK(check_expire_namehooks(adbname, now, adb->overmem) ==
		      ISC_FALSE);

	/*
	 * Do we know that the name is an alias?
	 */
	if (!EXPIRE_OK(adbname->expire_target, now)) {
		/*
		 * Yes, it is.
		 */
		DP(DEF_LEVEL,
		   "dns_adb_createfind: name %p is an alias (cached)",
		   adbname);
		alias = ISC_TRUE;
		goto post_copy;
	}

	/*
	 * Try to populate the name from the database and/or
	 * start fetches.  First try looking for an A record
	 * in the database.
	 */
	if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now)
	    && WANT_INET(wanted_addresses)) {
		result = dbfind_name(adbname, now, dns_rdatatype_a);
		if (result == ISC_R_SUCCESS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: found A for name %p in db",
			   adbname);
			goto v6;
		}

		/*
		 * Did we get a CNAME or DNAME?
		 */
		if (result == DNS_R_ALIAS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: name %p is an alias",
			   adbname);
			alias = ISC_TRUE;
			goto post_copy;
		}

		/*
		 * If the name doesn't exist at all, don't bother with
		 * v6 queries; they won't work.
		 *
		 * If the name does exist but we didn't get our data, go
		 * ahead and try AAAA.
		 *
		 * If the result is neither of these, try a fetch for A.
		 */
		if (NXDOMAIN_RESULT(result))
			goto fetch;
		else if (NXRRSET_RESULT(result))
			goto v6;

		if (!NAME_FETCH_V4(adbname))
			wanted_fetches |= DNS_ADBFIND_INET;
	}

 v6:
	if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now)
	    && WANT_INET6(wanted_addresses)) {
		result = dbfind_name(adbname, now, dns_rdatatype_aaaa);
		if (result == ISC_R_SUCCESS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: found AAAA for name %p",
			   adbname);
			goto fetch;
		}

		/*
		 * Did we get a CNAME or DNAME?
		 */
		if (result == DNS_R_ALIAS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: name %p is an alias",
			   adbname);
			alias = ISC_TRUE;
			goto post_copy;
		}

		/*
		 * Listen to negative cache hints, and don't start
		 * another query.
		 */
		if (NCACHE_RESULT(result) || AUTH_NX(result))
			goto fetch;

		if (!NAME_FETCH_V6(adbname))
			wanted_fetches |= DNS_ADBFIND_INET6;
	}

 fetch:
	if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) ||
	    (WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname)))
		have_address = ISC_TRUE;
	else
		have_address = ISC_FALSE;
	if (wanted_fetches != 0 &&
	    ! (FIND_AVOIDFETCHES(find) && have_address)) {
		/*
		 * We're missing at least one address family.  Either the
		 * caller hasn't instructed us to avoid fetches, or we don't
		 * know anything about any of the address families that would
		 * be acceptable so we have to launch fetches.
		 */

		if (FIND_STARTATZONE(find))
			start_at_zone = ISC_TRUE;

		/*
		 * Start V4.
		 */
		if (WANT_INET(wanted_fetches) &&
		    fetch_name(adbname, start_at_zone,
			       dns_rdatatype_a) == ISC_R_SUCCESS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: started A fetch for name %p",
			   adbname);
		}

		/*
		 * Start V6.
		 */
		if (WANT_INET6(wanted_fetches) &&
		    fetch_name(adbname, start_at_zone,
			       dns_rdatatype_aaaa) == ISC_R_SUCCESS) {
			DP(DEF_LEVEL,
			   "dns_adb_createfind: "
			   "started AAAA fetch for name %p",
			   adbname);
		}
	}

	/*
	 * Run through the name and copy out the bits we are
	 * interested in.
	 */
	copy_namehook_lists(adb, find, zone, adbname, now);

 post_copy:
	if (NAME_FETCH_V4(adbname))
		query_pending |= DNS_ADBFIND_INET;
	if (NAME_FETCH_V6(adbname))
		query_pending |= DNS_ADBFIND_INET6;

	/*
	 * Attach to the name's query list if there are queries
	 * already running, and we have been asked to.
	 */
	want_event = ISC_TRUE;
	if (!FIND_WANTEVENT(find))
		want_event = ISC_FALSE;
	if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find))
		want_event = ISC_FALSE;
	if ((wanted_addresses & query_pending) == 0)
		want_event = ISC_FALSE;
	if (alias)
		want_event = ISC_FALSE;
	if (want_event) {
		find->adbname = adbname;
		find->name_bucket = bucket;
		ISC_LIST_APPEND(adbname->finds, find, plink);
		find->query_pending = (query_pending & wanted_addresses);
		find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
		find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK);
		DP(DEF_LEVEL, "createfind: attaching find %p to adbname %p",
		   find, adbname);
	} else {
		/*
		 * Remove the flag so the caller knows there will never
		 * be an event, and set internal flags to fake that
		 * the event was sent and freed, so dns_adb_destroyfind() will
		 * do the right thing.
		 */
		find->query_pending = (query_pending & wanted_addresses);
		find->options &= ~DNS_ADBFIND_WANTEVENT;
		find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED);
		find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
	}

	find->partial_result |= (adbname->partial_result & wanted_addresses);
	i