static void
register_keys(const cfg_obj_t *control, const cfg_obj_t *keylist,
	      controlkeylist_t *keyids, isc_mem_t *mctx, const char *socktext)
{
	controlkey_t *keyid, *next;
	const cfg_obj_t *keydef;
	char secret[1024];
	isc_buffer_t b;
	isc_result_t result;

	/*
	 * Find the keys corresponding to the keyids used by this listener.
	 */
	for (keyid = ISC_LIST_HEAD(*keyids); keyid != NULL; keyid = next) {
		next = ISC_LIST_NEXT(keyid, link);

		result = cfgkeylist_find(keylist, keyid->keyname, &keydef);
		if (result != ISC_R_SUCCESS) {
			cfg_obj_log(control, ns_g_lctx, ISC_LOG_WARNING,
				    "couldn't find key '%s' for use with "
				    "command channel %s",
				    keyid->keyname, socktext);
			ISC_LIST_UNLINK(*keyids, keyid, link);
			free_controlkey(keyid, mctx);
		} else {
			const cfg_obj_t *algobj = NULL;
			const cfg_obj_t *secretobj = NULL;
			const char *algstr = NULL;
			const char *secretstr = NULL;
			unsigned int algtype;

			(void)cfg_map_get(keydef, "algorithm", &algobj);
			(void)cfg_map_get(keydef, "secret", &secretobj);
			INSIST(algobj != NULL && secretobj != NULL);

			algstr = cfg_obj_asstring(algobj);
			secretstr = cfg_obj_asstring(secretobj);

			if (ns_config_getkeyalgorithm2(algstr, NULL,
					&algtype, NULL) != ISC_R_SUCCESS)
			{
				cfg_obj_log(control, ns_g_lctx,
					    ISC_LOG_WARNING,
					    "unsupported algorithm '%s' in "
					    "key '%s' for use with command "
					    "channel %s",
					    algstr, keyid->keyname, socktext);
				ISC_LIST_UNLINK(*keyids, keyid, link);
				free_controlkey(keyid, mctx);
				continue;
			}

			keyid->algorithm = algtype;
			isc_buffer_init(&b, secret, sizeof(secret));
			result = isc_base64_decodestring(secretstr, &b);

			if (result != ISC_R_SUCCESS) {
				cfg_obj_log(keydef, ns_g_lctx, ISC_LOG_WARNING,
					    "secret for key '%s' on "
					    "command channel %s: %s",
					    keyid->keyname, socktext,
					    isc_result_totext(result));
				ISC_LIST_UNLINK(*keyids, keyid, link);
				free_controlkey(keyid, mctx);
				continue;
			}

			keyid->secret.length = isc_buffer_usedlength(&b);
			keyid->secret.base = isc_mem_get(mctx,
							 keyid->secret.length);
			if (keyid->secret.base == NULL) {
				cfg_obj_log(keydef, ns_g_lctx, ISC_LOG_WARNING,
					   "couldn't register key '%s': "
					   "out of memory", keyid->keyname);
				ISC_LIST_UNLINK(*keyids, keyid, link);
				free_controlkey(keyid, mctx);
				break;
			}
			memmove(keyid->secret.base, isc_buffer_base(&b),
				keyid->secret.length);
		}
	}
}

//.........这里部分代码省略.........

    /*
     * In any case, clamp how much we need to how much we can add.
     */
    needed = ISC_MIN (needed, RND_POOLBITS - ent->pool.entropy);

    /*
     * But wait!  If we're not yet initialized, we need at least
     *  THRESHOLD_BITS
     * of randomness.
     */
    if (ent->initialized < THRESHOLD_BITS)
        needed = ISC_MAX (needed, THRESHOLD_BITS - ent->initialized);

    /*
     * Poll each file source to see if we can read anything useful from
     * it.  XXXMLG When where are multiple sources, we should keep a
     * record of which one we last used so we can start from it (or the
     * next one) to avoid letting some sources build up entropy while
     * others are always drained.
     */

    added = 0;
    remaining = needed;
    if (ent->nextsource == NULL)
    {
        ent->nextsource = ISC_LIST_HEAD (ent->sources);
        if (ent->nextsource == NULL)
            return;
    }
    source = ent->nextsource;
  again_file:
    for (nsource = 0; nsource < ent->nsources; nsource++)
    {
        unsigned int got;

        if (remaining == 0)
            break;

        got = 0;

        switch (source->type)
        {
            case ENTROPY_SOURCETYPE_FILE:
                got = get_from_filesource (source, remaining);
                break;

            case ENTROPY_SOURCETYPE_USOCKET:
                got = get_from_usocketsource (source, remaining);
                break;
        }

        added += got;

        remaining -= ISC_MIN (remaining, got);

        source = ISC_LIST_NEXT (source, link);
        if (source == NULL)
            source = ISC_LIST_HEAD (ent->sources);
    }
    ent->nextsource = source;

    if (blocking && remaining != 0)
    {
        int fds;

        fds = wait_for_sources (ent);
        if (fds > 0)
            goto again_file;
    }

    /*
     * Here, if there are bits remaining to be had and we can block,
     * check to see if we have a callback source.  If so, call them.
     */
    source = ISC_LIST_HEAD (ent->sources);
    while ((remaining != 0) && (source != NULL))
    {
        unsigned int got;

        got = 0;

        if (source->type == ENTROPY_SOURCETYPE_CALLBACK)
            got = get_from_callback (source, remaining, blocking);

        added += got;
        remaining -= ISC_MIN (remaining, got);

        if (added >= needed)
            break;

        source = ISC_LIST_NEXT (source, link);
    }

    /*
     * Mark as initialized if we've added enough data.
     */
    if (ent->initialized < THRESHOLD_BITS)
        ent->initialized += added;
}

void
isc_taskmgr_renderxml(isc_taskmgr_t *mgr0, xmlTextWriterPtr writer) {
	isc__taskmgr_t *mgr = (isc__taskmgr_t *)mgr0;
	isc__task_t *task;

	LOCK(&mgr->lock);

	/*
	 * Write out the thread-model, and some details about each depending
	 * on which type is enabled.
	 */
	xmlTextWriterStartElement(writer, ISC_XMLCHAR "thread-model");
#ifdef ISC_PLATFORM_USETHREADS
	xmlTextWriterStartElement(writer, ISC_XMLCHAR "type");
	xmlTextWriterWriteString(writer, ISC_XMLCHAR "threaded");
	xmlTextWriterEndElement(writer); /* type */

	xmlTextWriterStartElement(writer, ISC_XMLCHAR "worker-threads");
	xmlTextWriterWriteFormatString(writer, "%d", mgr->workers);
	xmlTextWriterEndElement(writer); /* worker-threads */
#else /* ISC_PLATFORM_USETHREADS */
	xmlTextWriterStartElement(writer, ISC_XMLCHAR "type");
	xmlTextWriterWriteString(writer, ISC_XMLCHAR "non-threaded");
	xmlTextWriterEndElement(writer); /* type */

	xmlTextWriterStartElement(writer, ISC_XMLCHAR "references");
	xmlTextWriterWriteFormatString(writer, "%d", mgr->refs);
	xmlTextWriterEndElement(writer); /* references */
#endif /* ISC_PLATFORM_USETHREADS */

	xmlTextWriterStartElement(writer, ISC_XMLCHAR "default-quantum");
	xmlTextWriterWriteFormatString(writer, "%d", mgr->default_quantum);
	xmlTextWriterEndElement(writer); /* default-quantum */

	xmlTextWriterStartElement(writer, ISC_XMLCHAR "tasks-running");
	xmlTextWriterWriteFormatString(writer, "%d", mgr->tasks_running);
	xmlTextWriterEndElement(writer); /* tasks-running */

	xmlTextWriterEndElement(writer); /* thread-model */

	xmlTextWriterStartElement(writer, ISC_XMLCHAR "tasks");
	task = ISC_LIST_HEAD(mgr->tasks);
	while (task != NULL) {
		LOCK(&task->lock);
		xmlTextWriterStartElement(writer, ISC_XMLCHAR "task");

		if (task->name[0] != 0) {
			xmlTextWriterStartElement(writer, ISC_XMLCHAR "name");
			xmlTextWriterWriteFormatString(writer, "%s",
						       task->name);
			xmlTextWriterEndElement(writer); /* name */
		}

		xmlTextWriterStartElement(writer, ISC_XMLCHAR "references");
		xmlTextWriterWriteFormatString(writer, "%d", task->references);
		xmlTextWriterEndElement(writer); /* references */

		xmlTextWriterStartElement(writer, ISC_XMLCHAR "id");
		xmlTextWriterWriteFormatString(writer, "%p", task);
		xmlTextWriterEndElement(writer); /* id */

		xmlTextWriterStartElement(writer, ISC_XMLCHAR "state");
		xmlTextWriterWriteFormatString(writer, "%s",
					       statenames[task->state]);
		xmlTextWriterEndElement(writer); /* state */

		xmlTextWriterStartElement(writer, ISC_XMLCHAR "quantum");
		xmlTextWriterWriteFormatString(writer, "%d", task->quantum);
		xmlTextWriterEndElement(writer); /* quantum */

		xmlTextWriterEndElement(writer);

		UNLOCK(&task->lock);
		task = ISC_LIST_NEXT(task, link);
	}
	xmlTextWriterEndElement(writer); /* tasks */

	UNLOCK(&mgr->lock);
}

isc_result_t
dns_diff_print(dns_diff_t *diff, FILE *file) {
	isc_result_t result;
	dns_difftuple_t *t;
	char *mem = NULL;
	unsigned int size = 2048;
	const char *op = NULL;

	REQUIRE(DNS_DIFF_VALID(diff));

	mem = isc_mem_get(diff->mctx, size);
	if (mem == NULL)
		return (ISC_R_NOMEMORY);

	for (t = ISC_LIST_HEAD(diff->tuples); t != NULL;
	     t = ISC_LIST_NEXT(t, link))
	{
		isc_buffer_t buf;
		isc_region_t r;

		dns_rdatalist_t rdl;
		dns_rdataset_t rds;
		dns_rdata_t rd = DNS_RDATA_INIT;

		result = diff_tuple_tordataset(t, &rd, &rdl, &rds);
		if (result != ISC_R_SUCCESS) {
			UNEXPECTED_ERROR(__FILE__, __LINE__,
					 "diff_tuple_tordataset failed: %s",
					 dns_result_totext(result));
			result =  ISC_R_UNEXPECTED;
			goto cleanup;
		}
 again:
		isc_buffer_init(&buf, mem, size);
		result = dns_rdataset_totext(&rds, &t->name,
					     ISC_FALSE, ISC_FALSE, &buf);

		if (result == ISC_R_NOSPACE) {
			isc_mem_put(diff->mctx, mem, size);
			size += 1024;
			mem = isc_mem_get(diff->mctx, size);
			if (mem == NULL) {
				result = ISC_R_NOMEMORY;
				goto cleanup;
			}
			goto again;
		}

		if (result != ISC_R_SUCCESS)
			goto cleanup;
		/*
		 * Get rid of final newline.
		 */
		INSIST(buf.used >= 1 &&
		       ((char *) buf.base)[buf.used-1] == '\n');
		buf.used--;

		isc_buffer_usedregion(&buf, &r);
		switch (t->op) {
		case DNS_DIFFOP_EXISTS: op = "exists"; break;
		case DNS_DIFFOP_ADD: op = "add"; break;
		case DNS_DIFFOP_DEL: op = "del"; break;
		case DNS_DIFFOP_ADDRESIGN: op = "add re-sign"; break;
		case DNS_DIFFOP_DELRESIGN: op = "del re-sign"; break;
		}
		if (file != NULL)
			fprintf(file, "%s %.*s\n", op, (int) r.length,
				(char *) r.base);
		else
			isc_log_write(DIFF_COMMON_LOGARGS, ISC_LOG_DEBUG(7),
				      "%s %.*s", op, (int) r.length,
				      (char *) r.base);
	}
	result = ISC_R_SUCCESS;
 cleanup:
	if (mem != NULL)
		isc_mem_put(diff->mctx, mem, size);
	return (result);
}

ISC_APPFUNC_SCOPE isc_result_t
isc__app_ctxrun(isc_appctx_t *ctx0) {
	isc__appctx_t *ctx = (isc__appctx_t *)ctx0;
	int result;
	isc_event_t *event, *next_event;
	isc_task_t *task;
	sigset_t sset;
	char strbuf[ISC_STRERRORSIZE];
#ifdef HAVE_SIGWAIT
	int sig;
#endif

	REQUIRE(VALID_APPCTX(ctx));

#ifdef HAVE_LINUXTHREADS
	REQUIRE(main_thread == pthread_self());
#endif

	LOCK(&ctx->lock);

	if (!ctx->running) {
		ctx->running = ISC_TRUE;

		/*
		 * Post any on-run events (in FIFO order).
		 */
		for (event = ISC_LIST_HEAD(ctx->on_run);
		     event != NULL;
		     event = next_event) {
			next_event = ISC_LIST_NEXT(event, ev_link);
			ISC_LIST_UNLINK(ctx->on_run, event, ev_link);
			task = event->ev_sender;
			event->ev_sender = NULL;
			isc_task_sendanddetach(&task, &event);
		}

	}

	UNLOCK(&ctx->lock);

#ifndef HAVE_SIGWAIT
	/*
	 * Catch SIGHUP.
	 *
	 * We do this here to ensure that the signal handler is installed
	 * (i.e. that it wasn't a "one-shot" handler).
	 */
	if (ctx == &isc_g_appctx) {
		result = handle_signal(SIGHUP, reload_action);
		if (result != ISC_R_SUCCESS)
			return (ISC_R_SUCCESS);
	}
#endif

	/*
	 * When we are using multiple contexts, we don't rely on signals.
	 */
	if (ctx == &isc_g_appctx) {

	/*
	 * There is no danger if isc_app_shutdown() is called before we wait
	 * for signals.  Signals are blocked, so any such signal will simply
	 * be made pending and we will get it when we call sigwait().
	 */

	while (!ctx->want_shutdown) {
#ifdef HAVE_SIGWAIT
		/*
		 * Wait for SIGHUP, SIGINT, or SIGTERM.
		 */
		if (sigemptyset(&sset) != 0 ||
		    sigaddset(&sset, SIGHUP) != 0 ||
		    sigaddset(&sset, SIGINT) != 0 ||
		    sigaddset(&sset, SIGTERM) != 0) {
			isc__strerror(errno, strbuf, sizeof(strbuf));
			UNEXPECTED_ERROR(__FILE__, __LINE__,
					 "isc_app_run() sigsetops: %s", strbuf);
			return (ISC_R_UNEXPECTED);
		}

#ifndef HAVE_UNIXWARE_SIGWAIT
		result = sigwait(&sset, &sig);
		if (result == 0) {
			if (sig == SIGINT || sig == SIGTERM)
				ctx->want_shutdown = ISC_TRUE;
			else if (sig == SIGHUP)
				ctx->want_reload = ISC_TRUE;
		}

#else /* Using UnixWare sigwait semantics. */
		sig = sigwait(&sset);
		if (sig >= 0) {
			if (sig == SIGINT || sig == SIGTERM)
				ctx->want_shutdown = ISC_TRUE;
			else if (sig == SIGHUP)
				ctx->want_reload = ISC_TRUE;
		}

#endif /* HAVE_UNIXWARE_SIGWAIT */
#else  /* Don't have sigwait(). */
//.........这里部分代码省略.........

isc_result_t
ns_stats_dump(ns_server_t *server, FILE *fp) {
	isc_stdtime_t now;
	isc_result_t result;
	dns_view_t *view;
	dns_zone_t *zone, *next;
	stats_dumparg_t dumparg;
	isc_uint64_t nsstat_values[dns_nsstatscounter_max];
	isc_uint64_t resstat_values[dns_resstatscounter_max];
	isc_uint64_t zonestat_values[dns_zonestatscounter_max];
	isc_uint64_t sockstat_values[isc_sockstatscounter_max];

	RUNTIME_CHECK(isc_once_do(&once, init_desc) == ISC_R_SUCCESS);

	/* Set common fields */
	dumparg.type = statsformat_file;
	dumparg.arg = fp;

	isc_stdtime_get(&now);
	fprintf(fp, "+++ Statistics Dump +++ (%lu)\n", (unsigned long)now);

	fprintf(fp, "++ Incoming Requests ++\n");
	dns_opcodestats_dump(server->opcodestats, opcodestat_dump, &dumparg, 0);

	fprintf(fp, "++ Incoming Queries ++\n");
	dns_rdatatypestats_dump(server->rcvquerystats, rdtypestat_dump,
				&dumparg, 0);

	fprintf(fp, "++ Outgoing Queries ++\n");
	for (view = ISC_LIST_HEAD(server->viewlist);
	     view != NULL;
	     view = ISC_LIST_NEXT(view, link)) {
		if (view->resquerystats == NULL)
			continue;
		if (strcmp(view->name, "_default") == 0)
			fprintf(fp, "[View: default]\n");
		else
			fprintf(fp, "[View: %s]\n", view->name);
		dns_rdatatypestats_dump(view->resquerystats, rdtypestat_dump,
					&dumparg, 0);
	}

	fprintf(fp, "++ Name Server Statistics ++\n");
	(void) dump_counters(server->nsstats, statsformat_file, fp, NULL,
			     nsstats_desc, dns_nsstatscounter_max,
			     nsstats_index, nsstat_values, 0);

	fprintf(fp, "++ Zone Maintenance Statistics ++\n");
	(void) dump_counters(server->zonestats, statsformat_file, fp, NULL,
			     zonestats_desc, dns_zonestatscounter_max,
			     zonestats_index, zonestat_values, 0);

	fprintf(fp, "++ Resolver Statistics ++\n");
	fprintf(fp, "[Common]\n");
	(void) dump_counters(server->resolverstats, statsformat_file, fp, NULL,
			     resstats_desc, dns_resstatscounter_max,
			     resstats_index, resstat_values, 0);
	for (view = ISC_LIST_HEAD(server->viewlist);
	     view != NULL;
	     view = ISC_LIST_NEXT(view, link)) {
		if (view->resstats == NULL)
			continue;
		if (strcmp(view->name, "_default") == 0)
			fprintf(fp, "[View: default]\n");
		else
			fprintf(fp, "[View: %s]\n", view->name);
		(void) dump_counters(view->resstats, statsformat_file, fp, NULL,
				     resstats_desc, dns_resstatscounter_max,
				     resstats_index, resstat_values, 0);
	}

	fprintf(fp, "++ Cache DB RRsets ++\n");
	for (view = ISC_LIST_HEAD(server->viewlist);
	     view != NULL;
	     view = ISC_LIST_NEXT(view, link)) {
		dns_stats_t *cachestats;

		cachestats = dns_db_getrrsetstats(view->cachedb);
		if (cachestats == NULL)
			continue;
		if (strcmp(view->name, "_default") == 0)
			fprintf(fp, "[View: default]\n");
		else
			fprintf(fp, "[View: %s (Cache: %s)]\n", view->name,
				dns_cache_getname(view->cache));
		if (dns_view_iscacheshared(view)) {
			/*
			 * Avoid dumping redundant statistics when the cache is
			 * shared.
			 */
			continue;
		}
		dns_rdatasetstats_dump(cachestats, rdatasetstats_dump, &dumparg,
				       0);
	}

	fprintf(fp, "++ Socket I/O Statistics ++\n");
	(void) dump_counters(server->sockstats, statsformat_file, fp, NULL,
			     sockstats_desc, isc_sockstatscounter_max,
			     sockstats_index, sockstat_values, 0);
//.........这里部分代码省略.........

static isc_result_t
diff_apply(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver,
	   isc_boolean_t warn)
{
	dns_difftuple_t *t;
	dns_dbnode_t *node = NULL;
	isc_result_t result;
	char namebuf[DNS_NAME_FORMATSIZE];
	char typebuf[DNS_RDATATYPE_FORMATSIZE];
	char classbuf[DNS_RDATACLASS_FORMATSIZE];

	REQUIRE(DNS_DIFF_VALID(diff));
	REQUIRE(DNS_DB_VALID(db));

	t = ISC_LIST_HEAD(diff->tuples);
	while (t != NULL) {
		dns_name_t *name;

		INSIST(node == NULL);
		name = &t->name;
		/*
		 * Find the node.
		 * We create the node if it does not exist.
		 * This will cause an empty node to be created if the diff
		 * contains a deletion of an RR at a nonexistent name,
		 * but such diffs should never be created in the first
		 * place.
		 */

		while (t != NULL && dns_name_equal(&t->name, name)) {
			dns_rdatatype_t type, covers;
			dns_diffop_t op;
			dns_rdatalist_t rdl;
			dns_rdataset_t rds;
			dns_rdataset_t ardataset;
			dns_rdataset_t *modified = NULL;

			op = t->op;
			type = t->rdata.type;
			covers = rdata_covers(&t->rdata);

			/*
			 * Collect a contiguous set of updates with
			 * the same operation (add/delete) and RR type
			 * into a single rdatalist so that the
			 * database rrset merging/subtraction code
			 * can work more efficiently than if each
			 * RR were merged into / subtracted from
			 * the database separately.
			 *
			 * This is done by linking rdata structures from the
			 * diff into "rdatalist".  This uses the rdata link
			 * field, not the diff link field, so the structure
			 * of the diff itself is not affected.
			 */

			rdl.type = type;
			rdl.covers = covers;
			rdl.rdclass = t->rdata.rdclass;
			rdl.ttl = t->ttl;
			ISC_LIST_INIT(rdl.rdata);
			ISC_LINK_INIT(&rdl, link);

			node = NULL;
			if (type != dns_rdatatype_nsec3 &&
			    covers != dns_rdatatype_nsec3)
				CHECK(dns_db_findnode(db, name, ISC_TRUE,
						      &node));
			else
				CHECK(dns_db_findnsec3node(db, name, ISC_TRUE,
							   &node));

			while (t != NULL &&
			       dns_name_equal(&t->name, name) &&
			       t->op == op &&
			       t->rdata.type == type &&
			       rdata_covers(&t->rdata) == covers)
			{
				dns_name_format(name, namebuf, sizeof(namebuf));
				dns_rdatatype_format(t->rdata.type, typebuf,
						     sizeof(typebuf));
				dns_rdataclass_format(t->rdata.rdclass,
						      classbuf,
						      sizeof(classbuf));
				if (t->ttl != rdl.ttl && warn)
					isc_log_write(DIFF_COMMON_LOGARGS,
						ISC_LOG_WARNING,
						"'%s/%s/%s': TTL differs in "
						"rdataset, adjusting "
						"%lu -> %lu",
						namebuf, typebuf, classbuf,
						(unsigned long) t->ttl,
						(unsigned long) rdl.ttl);
				ISC_LIST_APPEND(rdl.rdata, &t->rdata, link);
				t = ISC_LIST_NEXT(t, link);
			}

			/*
			 * Convert the rdatalist into a rdataset.
			 */
//.........这里部分代码省略.........

static void
resolve_ns(isc_task_t *task, isc_event_t *event) {
	struct probe_trans *trans = event->ev_arg;
	dns_clientresevent_t *rev = (dns_clientresevent_t *)event;
	dns_name_t *name;
	dns_rdataset_t *rdataset;
	isc_result_t result = ISC_R_SUCCESS;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	struct probe_ns *pns;

	REQUIRE(task == probe_task);
	REQUIRE(trans->inuse == ISC_TRUE);
	INSIST(outstanding_probes > 0);

	for (name = ISC_LIST_HEAD(rev->answerlist); name != NULL;
	     name = ISC_LIST_NEXT(name, link)) {
		for (rdataset = ISC_LIST_HEAD(name->list);
		     rdataset != NULL;
		     rdataset = ISC_LIST_NEXT(rdataset, link)) {
			(void)print_rdataset(rdataset, name);

			if (rdataset->type != dns_rdatatype_ns)
				continue;

			for (result = dns_rdataset_first(rdataset);
			     result == ISC_R_SUCCESS;
			     result = dns_rdataset_next(rdataset)) {
				dns_rdata_ns_t ns;

				dns_rdataset_current(rdataset, &rdata);
				/*
				 * Extract the name from the NS record.
				 */
				result = dns_rdata_tostruct(&rdata, &ns, NULL);
				if (result != ISC_R_SUCCESS)
					continue;

				pns = isc_mem_get(mctx, sizeof(*pns));
				if (pns == NULL) {
					fprintf(stderr,
						"resolve_ns: mem_get failed");
					result = ISC_R_NOMEMORY;
					POST(result);
					/*
					 * XXX: should we continue with the
					 * available servers anyway?
					 */
					goto cleanup;
				}

				dns_fixedname_init(&pns->fixedname);
				pns->name =
					dns_fixedname_name(&pns->fixedname);
				ISC_LINK_INIT(pns, link);
				ISC_LIST_APPEND(trans->nslist, pns, link);
				ISC_LIST_INIT(pns->servers);

				dns_name_copy(&ns.name, pns->name, NULL);
				dns_rdata_reset(&rdata);
				dns_rdata_freestruct(&ns);
			}
		}
	}

 cleanup:
	dns_client_freeresanswer(client, &rev->answerlist);
	dns_client_destroyrestrans(&trans->resid);
	isc_event_free(&event);

	if (!ISC_LIST_EMPTY(trans->nslist)) {
		/* Go get addresses of NSes */
		trans->current_ns = ISC_LIST_HEAD(trans->nslist);
		result = fetch_nsaddress(trans);
	} else
		result = ISC_R_FAILURE;

	if (result == ISC_R_SUCCESS)
		return;

	reset_probe(trans);
}

static isc_result_t
do_scan(ns_interfacemgr_t *mgr, ns_listenlist_t *ext_listen,
	isc_boolean_t verbose)
{
	isc_interfaceiter_t *iter = NULL;
	isc_boolean_t scan_ipv4 = ISC_FALSE;
	isc_boolean_t scan_ipv6 = ISC_FALSE;
	isc_boolean_t adjusting = ISC_FALSE;
	isc_boolean_t ipv6only = ISC_TRUE;
	isc_boolean_t ipv6pktinfo = ISC_TRUE;
	isc_result_t result;
	isc_netaddr_t zero_address, zero_address6;
	ns_listenelt_t *le;
	isc_sockaddr_t listen_addr;
	ns_interface_t *ifp;
	isc_boolean_t log_explicit = ISC_FALSE;
	isc_boolean_t dolistenon;

	if (ext_listen != NULL)
		adjusting = ISC_TRUE;

	if (isc_net_probeipv6() == ISC_R_SUCCESS)
		scan_ipv6 = ISC_TRUE;
#ifdef WANT_IPV6
	else
		isc_log_write(IFMGR_COMMON_LOGARGS,
			      verbose ? ISC_LOG_INFO : ISC_LOG_DEBUG(1),
			      "no IPv6 interfaces found");
#endif

	if (isc_net_probeipv4() == ISC_R_SUCCESS)
		scan_ipv4 = ISC_TRUE;
	else
		isc_log_write(IFMGR_COMMON_LOGARGS,
			      verbose ? ISC_LOG_INFO : ISC_LOG_DEBUG(1),
			      "no IPv4 interfaces found");

	/*
	 * A special, but typical case; listen-on-v6 { any; }.
	 * When we can make the socket IPv6-only, open a single wildcard
	 * socket for IPv6 communication.  Otherwise, make separate socket
	 * for each IPv6 address in order to avoid accepting IPv4 packets
	 * as the form of mapped addresses unintentionally unless explicitly
	 * allowed.
	 */
#ifndef ISC_ALLOW_MAPPED
	if (scan_ipv6 == ISC_TRUE &&
	    isc_net_probe_ipv6only() != ISC_R_SUCCESS) {
		ipv6only = ISC_FALSE;
		log_explicit = ISC_TRUE;
	}
#endif
	if (scan_ipv6 == ISC_TRUE &&
	    isc_net_probe_ipv6pktinfo() != ISC_R_SUCCESS) {
		ipv6pktinfo = ISC_FALSE;
		log_explicit = ISC_TRUE;
	}
	if (scan_ipv6 == ISC_TRUE && ipv6only && ipv6pktinfo) {
		for (le = ISC_LIST_HEAD(mgr->listenon6->elts);
		     le != NULL;
		     le = ISC_LIST_NEXT(le, link)) {
			struct in6_addr in6a;

			if (!listenon_is_ip6_any(le))
				continue;

			in6a = in6addr_any;
			isc_sockaddr_fromin6(&listen_addr, &in6a, le->port);

			ifp = find_matching_interface(mgr, &listen_addr);
			if (ifp != NULL) {
				ifp->generation = mgr->generation;
			} else {
				isc_log_write(IFMGR_COMMON_LOGARGS,
					      ISC_LOG_INFO,
					      "listening on IPv6 "
					      "interfaces, port %u",
					      le->port);
				result = ns_interface_setup(mgr, &listen_addr,
							    "<any>", &ifp,
							    ISC_TRUE);
				if (result == ISC_R_SUCCESS)
					ifp->flags |= NS_INTERFACEFLAG_ANYADDR;
				else
					isc_log_write(IFMGR_COMMON_LOGARGS,
						      ISC_LOG_ERROR,
						      "listening on all IPv6 "
						      "interfaces failed");
				/* Continue. */
			}
		}
	}

	isc_netaddr_any(&zero_address);
	isc_netaddr_any6(&zero_address6);

	result = isc_interfaceiter_create(mgr->mctx, &iter);
	if (result != ISC_R_SUCCESS)
		return (result);

//.........这里部分代码省略.........

static void
request_done(isc_task_t *task, isc_event_t *event) {
	struct probe_trans *trans = event->ev_arg;
	dns_clientreqevent_t *rev = (dns_clientreqevent_t *)event;
	dns_message_t *rmessage;
	struct probe_ns *pns;
	struct server *server;
	isc_result_t result;
	query_result_t *resultp;
	dns_name_t *name;
	dns_rdataset_t *rdataset;
	dns_rdatatype_t type;

	REQUIRE(task == probe_task);
	REQUIRE(trans != NULL && trans->inuse == ISC_TRUE);
	rmessage = rev->rmessage;
	REQUIRE(rmessage == trans->rmessage);
	INSIST(outstanding_probes > 0);

	server = trans->current_ns->current_server;
	INSIST(server != NULL);

	if (server->result_a == none) {
		type = dns_rdatatype_a;
		resultp = &server->result_a;
	} else {
		resultp = &server->result_aaaa;
		type = dns_rdatatype_aaaa;
	}

	if (rev->result == ISC_R_SUCCESS) {
		if ((rmessage->flags & DNS_MESSAGEFLAG_AA) == 0)
			*resultp = lame;
		else if (rmessage->rcode == dns_rcode_nxdomain)
			*resultp = nxdomain;
		else if (rmessage->rcode != dns_rcode_noerror)
			*resultp = othererr;
		else if (rmessage->counts[DNS_SECTION_ANSWER] == 0) {
			/* no error but empty answer */
			*resultp = notype;
		} else {
			result = dns_message_firstname(rmessage,
						       DNS_SECTION_ANSWER);
			while (result == ISC_R_SUCCESS) {
				name = NULL;
				dns_message_currentname(rmessage,
							DNS_SECTION_ANSWER,
							&name);
				for (rdataset = ISC_LIST_HEAD(name->list);
				     rdataset != NULL;
				     rdataset = ISC_LIST_NEXT(rdataset,
							      link)) {
					(void)print_rdataset(rdataset, name);

					if (rdataset->type ==
					    dns_rdatatype_cname ||
					    rdataset->type ==
					    dns_rdatatype_dname) {
						/* Should chase the chain? */
						*resultp = exist;
						goto found;
					} else if (rdataset->type == type) {
						*resultp = exist;
						goto found;
					}
				}
				result = dns_message_nextname(rmessage,
							      DNS_SECTION_ANSWER);
			}

			/*
			 * Something unexpected happened: the response
			 * contained a non-empty authoritative answer, but we
			 * could not find an expected result.
			 */
			*resultp = unexpected;
		}
	} else if (rev->result == DNS_R_RECOVERABLE ||
		   rev->result == DNS_R_BADLABELTYPE) {
		/* Broken response.  Try identifying known cases. */
		*resultp = brokenanswer;

		if (rmessage->counts[DNS_SECTION_ANSWER] > 0) {
			result = dns_message_firstname(rmessage,
						       DNS_SECTION_ANSWER);
			while (result == ISC_R_SUCCESS) {
				/*
				 * Check to see if the response has multiple
				 * CNAME RRs.  Update the result code if so.
				 */
				name = NULL;
				dns_message_currentname(rmessage,
							DNS_SECTION_ANSWER,
							&name);
				for (rdataset = ISC_LIST_HEAD(name->list);
				     rdataset != NULL;
				     rdataset = ISC_LIST_NEXT(rdataset,
							      link)) {
					if (rdataset->type ==
					    dns_rdatatype_cname &&
//.........这里部分代码省略.........

static void
resolve_nsaddress(isc_task_t *task, isc_event_t *event) {
	struct probe_trans *trans = event->ev_arg;
	dns_clientresevent_t *rev = (dns_clientresevent_t *)event;
	dns_name_t *name;
	dns_rdataset_t *rdataset;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	struct probe_ns *pns = trans->current_ns;
	isc_result_t result;

	REQUIRE(task == probe_task);
	REQUIRE(trans->inuse == ISC_TRUE);
	REQUIRE(pns != NULL);
	INSIST(outstanding_probes > 0);

	for (name = ISC_LIST_HEAD(rev->answerlist); name != NULL;
	     name = ISC_LIST_NEXT(name, link)) {
		for (rdataset = ISC_LIST_HEAD(name->list);
		     rdataset != NULL;
		     rdataset = ISC_LIST_NEXT(rdataset, link)) {
			(void)print_rdataset(rdataset, name);

			if (rdataset->type != dns_rdatatype_a)
				continue;

			for (result = dns_rdataset_first(rdataset);
			     result == ISC_R_SUCCESS;
			     result = dns_rdataset_next(rdataset)) {
				dns_rdata_in_a_t rdata_a;
				struct server *server;

				dns_rdataset_current(rdataset, &rdata);
				result = dns_rdata_tostruct(&rdata, &rdata_a,
							    NULL);
				if (result != ISC_R_SUCCESS)
					continue;

				server = isc_mem_get(mctx, sizeof(*server));
				if (server == NULL) {
					fprintf(stderr, "resolve_nsaddress: "
						"mem_get failed");
					result = ISC_R_NOMEMORY;
					POST(result);
					goto cleanup;
				}
				isc_sockaddr_fromin(&server->address,
						    &rdata_a.in_addr, 53);
				ISC_LINK_INIT(server, link);
				server->result_a = none;
				server->result_aaaa = none;
				ISC_LIST_APPEND(pns->servers, server, link);
			}
		}
	}

 cleanup:
	dns_client_freeresanswer(client, &rev->answerlist);
	dns_client_destroyrestrans(&trans->resid);
	isc_event_free(&event);

 next_ns:
	trans->current_ns = ISC_LIST_NEXT(pns, link);
	if (trans->current_ns == NULL) {
		trans->current_ns = ISC_LIST_HEAD(trans->nslist);
		dns_fixedname_invalidate(&trans->fixedname);
		trans->qname = NULL;
		result = set_nextqname(trans);
		if (result == ISC_R_SUCCESS)
			 result = probe_name(trans, dns_rdatatype_a);
	} else {
		result = fetch_nsaddress(trans);
		if (result != ISC_R_SUCCESS)
			goto next_ns; /* XXX: this is unlikely to succeed */
	}

	if (result != ISC_R_SUCCESS)
		reset_probe(trans);
}

isc_result_t
res_nupdate(res_state statp, ns_updrec *rrecp_in) {
	ns_updrec *rrecp;
	double answer[PACKETSZ / sizeof (double)];
	double packet[2*PACKETSZ / sizeof (double)];
	struct zonegrp *zptr, tgrp;
	int nzones = 0, nscount = 0;
	unsigned n;
	unsigned rval;
	struct sockaddr_in nsaddrs[MAXNS];
	ns_tsig_key *key;
	void *zcookie = 0;
	void *zcookp = &zcookie;
	isc_result_t rcode;

      again:
	/* Make sure all the updates are in the same zone, and find out
	   what zone they are in. */
	zptr = NULL;
	for (rrecp = rrecp_in; rrecp; rrecp = ISC_LIST_NEXT(rrecp, r_link)) {
		/* Find the origin for it if there is one. */
		tgrp.z_class = rrecp->r_class;
		rcode = res_findzonecut(statp, rrecp->r_dname, tgrp.z_class,
					RES_EXHAUSTIVE,
					tgrp.z_origin,
					sizeof tgrp.z_origin,
					tgrp.z_nsaddrs, MAXNS, &tgrp.z_nscount,
					zcookp);
		if (rcode != ISC_R_SUCCESS)
			goto done;
		if (tgrp.z_nscount <= 0) {
			rcode = ISC_R_NOTZONE;
			goto done;
		}
		/* Make a group for it if there isn't one. */
		if (zptr == NULL) {
			zptr = malloc(sizeof *zptr);
			if (zptr == NULL) {
				rcode = ISC_R_NOMEMORY;
				goto done;
			}
			*zptr = tgrp;
			zptr->z_flags = 0;
			ISC_LIST_INIT(zptr->z_rrlist);
		} else if (ns_samename(tgrp.z_origin, zptr->z_origin) == 0 ||
			   tgrp.z_class != zptr->z_class) {
			/* Some of the records are in different zones. */
			rcode = ISC_R_CROSSZONE;
			goto done;
		}
		/* Thread this rrecp onto the zone group. */
		ISC_LIST_APPEND(zptr->z_rrlist, rrecp, r_glink);
	}

	/* Construct zone section and prepend it. */
	rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
			     zptr->z_class, ns_t_soa, 0);
	if (rrecp == NULL) {
		rcode = ISC_R_UNEXPECTED;
		goto done;
	}
	ISC_LIST_PREPEND(zptr->z_rrlist, rrecp, r_glink);
	zptr->z_flags |= ZG_F_ZONESECTADDED;

	/* Marshall the update message. */
	n = sizeof packet;
	rcode = res_nmkupdate(statp,
			      ISC_LIST_HEAD(zptr->z_rrlist), packet, &n);
	if (rcode != ISC_R_SUCCESS)
		goto done;

	/* Temporarily replace the resolver's nameserver set. */
	nscount = nscopy(nsaddrs, statp->nsaddr_list, statp->nscount);
	statp->nscount = nsprom(statp->nsaddr_list,
				zptr->z_nsaddrs, zptr->z_nscount);

	/* Send the update and remember the result. */
	key = (ns_tsig_key *)0;
	rcode = find_tsig_key (&key, zptr->z_origin, zcookie);
	if (rcode == ISC_R_SUCCESS) {
		rcode = res_nsendsigned(statp, packet, n, key,
					answer, sizeof answer, &rval);
		tkey_free (&key);
	} else if (rcode == ISC_R_NOTFOUND || rcode == ISC_R_KEY_UNKNOWN) {
		rcode = res_nsend(statp, packet, n,
				  answer, sizeof answer, &rval);
	}
	if (rcode != ISC_R_SUCCESS)
		goto undone;

	rcode = ns_rcode_to_isc (((HEADER *)answer)->rcode);
	if (zcookie && rcode == ISC_R_BADSIG) {
		repudiate_zone (&zcookie);
	}

 undone:
	/* Restore resolver's nameserver set. */
	statp->nscount = nscopy(statp->nsaddr_list, nsaddrs, nscount);
	nscount = 0;
 done:
//.........这里部分代码省略.........

isc_result_t
dns_ncache_addoptout(dns_message_t *message, dns_db_t *cache,
		     dns_dbnode_t *node, dns_rdatatype_t covers,
		     isc_stdtime_t now, dns_ttl_t maxttl,
		     isc_boolean_t optout, dns_rdataset_t *addedrdataset)
{
	isc_result_t result;
	isc_buffer_t buffer;
	isc_region_t r;
	dns_rdataset_t *rdataset;
	dns_rdatatype_t type;
	dns_name_t *name;
	dns_ttl_t ttl;
	dns_trust_t trust;
	dns_rdata_t rdata[DNS_NCACHE_RDATA];
	dns_rdataset_t ncrdataset;
	dns_rdatalist_t ncrdatalist;
	unsigned char data[4096];
	unsigned int next = 0;

	/*
	 * Convert the authority data from 'message' into a negative cache
	 * rdataset, and store it in 'cache' at 'node'.
	 */

	REQUIRE(message != NULL);

	/*
	 * We assume that all data in the authority section has been
	 * validated by the caller.
	 */

	/*
	 * Initialize the list.
	 */
	ncrdatalist.rdclass = dns_db_class(cache);
	ncrdatalist.type = 0;
	ncrdatalist.covers = covers;
	ncrdatalist.ttl = maxttl;
	ISC_LIST_INIT(ncrdatalist.rdata);
	ISC_LINK_INIT(&ncrdatalist, link);

	/*
	 * Build an ncache rdatas into buffer.
	 */
	ttl = maxttl;
	trust = 0xffff;
	isc_buffer_init(&buffer, data, sizeof(data));
	if (message->counts[DNS_SECTION_AUTHORITY])
		result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
	else
		result = ISC_R_NOMORE;
	while (result == ISC_R_SUCCESS) {
		name = NULL;
		dns_message_currentname(message, DNS_SECTION_AUTHORITY,
					&name);
		if ((name->attributes & DNS_NAMEATTR_NCACHE) != 0) {
			for (rdataset = ISC_LIST_HEAD(name->list);
			     rdataset != NULL;
			     rdataset = ISC_LIST_NEXT(rdataset, link)) {
				if ((rdataset->attributes &
				     DNS_RDATASETATTR_NCACHE) == 0)
					continue;
				type = rdataset->type;
				if (type == dns_rdatatype_rrsig)
					type = rdataset->covers;
				if (type == dns_rdatatype_soa ||
				    type == dns_rdatatype_nsec ||
				    type == dns_rdatatype_nsec3) {
					if (ttl > rdataset->ttl)
						ttl = rdataset->ttl;
					if (trust > rdataset->trust)
						trust = rdataset->trust;
					/*
					 * Copy the owner name to the buffer.
					 */
					dns_name_toregion(name, &r);
					result = isc_buffer_copyregion(&buffer,
								       &r);
					if (result != ISC_R_SUCCESS)
						return (result);
					/*
					 * Copy the type to the buffer.
					 */
					isc_buffer_availableregion(&buffer,
								   &r);
					if (r.length < 3)
						return (ISC_R_NOSPACE);
					isc_buffer_putuint16(&buffer,
							     rdataset->type);
					isc_buffer_putuint8(&buffer,
					       (unsigned char)rdataset->trust);
					/*
					 * Copy the rdataset into the buffer.
					 */
					result = copy_rdataset(rdataset,
							       &buffer);
					if (result != ISC_R_SUCCESS)
						return (result);

//.........这里部分代码省略.........

static void
update_listener(ns_controls_t *cp, controllistener_t **listenerp,
		const cfg_obj_t *control, const cfg_obj_t *config,
		isc_sockaddr_t *addr, cfg_aclconfctx_t *aclconfctx,
		const char *socktext, isc_sockettype_t type)
{
	controllistener_t *listener;
	const cfg_obj_t *allow;
	const cfg_obj_t *global_keylist = NULL;
	const cfg_obj_t *control_keylist = NULL;
	dns_acl_t *new_acl = NULL;
	controlkeylist_t keys;
	isc_result_t result = ISC_R_SUCCESS;

	for (listener = ISC_LIST_HEAD(cp->listeners);
	     listener != NULL;
	     listener = ISC_LIST_NEXT(listener, link))
		if (isc_sockaddr_equal(addr, &listener->address))
			break;

	if (listener == NULL) {
		*listenerp = NULL;
		return;
	}

	/*
	 * There is already a listener for this sockaddr.
	 * Update the access list and key information.
	 *
	 * First try to deal with the key situation.  There are a few
	 * possibilities:
	 *  (a)	It had an explicit keylist and still has an explicit keylist.
	 *  (b)	It had an automagic key and now has an explicit keylist.
	 *  (c)	It had an explicit keylist and now needs an automagic key.
	 *  (d) It has an automagic key and still needs the automagic key.
	 *
	 * (c) and (d) are the annoying ones.  The caller needs to know
	 * that it should use the automagic configuration for key information
	 * in place of the named.conf configuration.
	 *
	 * XXXDCL There is one other hazard that has not been dealt with,
	 * the problem that if a key change is being caused by a control
	 * channel reload, then the response will be with the new key
	 * and not able to be decrypted by the client.
	 */
	if (control != NULL)
		get_key_info(config, control, &global_keylist,
			     &control_keylist);

	if (control_keylist != NULL) {
		INSIST(global_keylist != NULL);

		ISC_LIST_INIT(keys);
		result = controlkeylist_fromcfg(control_keylist,
						listener->mctx, &keys);
		if (result == ISC_R_SUCCESS) {
			free_controlkeylist(&listener->keys, listener->mctx);
			listener->keys = keys;
			register_keys(control, global_keylist, &listener->keys,
				      listener->mctx, socktext);
		}
	} else {
		free_controlkeylist(&listener->keys, listener->mctx);
		result = get_rndckey(listener->mctx, &listener->keys);
	}

	if (result != ISC_R_SUCCESS && global_keylist != NULL) {
		/*
		 * This message might be a little misleading since the
		 * "new keys" might in fact be identical to the old ones,
		 * but tracking whether they are identical just for the
		 * sake of avoiding this message would be too much trouble.
		 */
		if (control != NULL)
			cfg_obj_log(control, ns_g_lctx, ISC_LOG_WARNING,
				    "couldn't install new keys for "
				    "command channel %s: %s",
				    socktext, isc_result_totext(result));
		else
			isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
				      NS_LOGMODULE_CONTROL, ISC_LOG_WARNING,
				      "couldn't install new keys for "
				      "command channel %s: %s",
				      socktext, isc_result_totext(result));
	}

	/*
	 * Now, keep the old access list unless a new one can be made.
	 */
	if (control != NULL && type == isc_sockettype_tcp) {
		allow = cfg_tuple_get(control, "allow");
		result = cfg_acl_fromconfig(allow, config, ns_g_lctx,
					    aclconfctx, listener->mctx, 0,
					    &new_acl);
	} else {
		result = dns_acl_any(listener->mctx, &new_acl);
	}

	if (result == ISC_R_SUCCESS) {
		dns_acl_detach(&listener->acl);
//.........这里部分代码省略.........

void
ns_xfr_start(ns_client_t *client, dns_rdatatype_t reqtype) {
	isc_result_t result;
	dns_name_t *question_name;
	dns_rdataset_t *question_rdataset;
	dns_zone_t *zone = NULL;
	dns_db_t *db = NULL;
	dns_dbversion_t *ver = NULL;
	dns_rdataclass_t question_class;
	rrstream_t *soa_stream = NULL;
	rrstream_t *data_stream = NULL;
	rrstream_t *stream = NULL;
	dns_difftuple_t *current_soa_tuple = NULL;
	dns_name_t *soa_name;
	dns_rdataset_t *soa_rdataset;
	dns_rdata_t soa_rdata = DNS_RDATA_INIT;
	isc_boolean_t have_soa = ISC_FALSE;
	const char *mnemonic = NULL;
	isc_mem_t *mctx = client->mctx;
	dns_message_t *request = client->message;
	xfrout_ctx_t *xfr = NULL;
	isc_quota_t *quota = NULL;
	dns_transfer_format_t format = client->view->transfer_format;
	isc_netaddr_t na;
	dns_peer_t *peer = NULL;
	isc_buffer_t *tsigbuf = NULL;
	char *journalfile;
	char msg[NS_CLIENT_ACLMSGSIZE("zone transfer")];
	char keyname[DNS_NAME_FORMATSIZE];
	isc_boolean_t is_poll = ISC_FALSE;
#ifdef DLZ
	isc_boolean_t is_dlz = ISC_FALSE;
#endif

	switch (reqtype) {
	case dns_rdatatype_axfr:
		mnemonic = "AXFR";
		break;
	case dns_rdatatype_ixfr:
		mnemonic = "IXFR";
		break;
	default:
		INSIST(0);
		break;
	}

	ns_client_log(client,
		      DNS_LOGCATEGORY_XFER_OUT, NS_LOGMODULE_XFER_OUT,
		      ISC_LOG_DEBUG(6), "%s request", mnemonic);
	/*
	 * Apply quota.
	 */
	result = isc_quota_attach(&ns_g_server->xfroutquota, &quota);
	if (result != ISC_R_SUCCESS) {
		isc_log_write(XFROUT_COMMON_LOGARGS, ISC_LOG_WARNING,
			      "%s request denied: %s", mnemonic,
			      isc_result_totext(result));
		goto failure;
	}

	/*
	 * Interpret the question section.
	 */
	result = dns_message_firstname(request, DNS_SECTION_QUESTION);
	INSIST(result == ISC_R_SUCCESS);

	/*
	 * The question section must contain exactly one question, and
	 * it must be for AXFR/IXFR as appropriate.
	 */
	question_name = NULL;
	dns_message_currentname(request, DNS_SECTION_QUESTION, &question_name);
	question_rdataset = ISC_LIST_HEAD(question_name->list);
	question_class = question_rdataset->rdclass;
	INSIST(question_rdataset->type == reqtype);
	if (ISC_LIST_NEXT(question_rdataset, link) != NULL)
		FAILC(DNS_R_FORMERR, "multiple questions");
	result = dns_message_nextname(request, DNS_SECTION_QUESTION);
	if (result != ISC_R_NOMORE)
		FAILC(DNS_R_FORMERR, "multiple questions");

	result = dns_zt_find(client->view->zonetable, question_name, 0, NULL,
			     &zone);

	if (result != ISC_R_SUCCESS)
#ifdef DLZ
	{
		/*
		 * Normal zone table does not have a match.  Try the DLZ database
		 */
		if (client->view->dlzdatabase != NULL) {
			result = dns_dlzallowzonexfr(client->view,
						     question_name, &client->peeraddr,
						     &db);

			if (result == ISC_R_NOPERM) {
				char _buf1[DNS_NAME_FORMATSIZE];
				char _buf2[DNS_RDATACLASS_FORMATSIZE];

				result = DNS_R_REFUSED;
//.........这里部分代码省略.........