1 files changed, 159 insertions, 94 deletions

diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 602dcf5f9632..3a02ba798e73 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: resolver.c,v 1.218.2.18.4.77.2.3 2008/07/24 05:00:46 jinmei Exp $ */
+/* $Id: resolver.c,v 1.218.2.18.4.85 2008/10/17 22:03:37 jinmei Exp $ */
 
 #include <config.h>
 
@@ -119,6 +119,7 @@ typedef struct query {
 	isc_mem_t *			mctx;
 	dns_dispatchmgr_t *		dispatchmgr;
 	dns_dispatch_t *		dispatch;
+	isc_boolean_t			exclusivesocket;
 	dns_adbaddrinfo_t *		addrinfo;
 	isc_socket_t *			tcpsocket;
 	isc_time_t			start;
@@ -301,7 +302,9 @@ struct dns_resolver {
 	unsigned int			options;
 	dns_dispatchmgr_t *		dispatchmgr;
 	dns_dispatch_t *		dispatchv4;
+	isc_boolean_t			exclusivev4;
 	dns_dispatch_t *		dispatchv6;
+	isc_boolean_t			exclusivev6;
 	unsigned int			nbuckets;
 	fctxbucket_t *			buckets;
 	isc_uint32_t			lame_ttl;
@@ -360,6 +363,8 @@ static isc_result_t ncache_adderesult(dns_message_t *message,
 				      isc_result_t *eresultp);
 static void validated(isc_task_t *task, isc_event_t *event);
 static void maybe_destroy(fetchctx_t *fctx);
+static void add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
+		    isc_result_t reason);
 
 static isc_result_t
 valcreate(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, dns_name_t *name,
@@ -549,6 +554,7 @@ fctx_cancelquery(resquery_t **queryp, dns_dispatchevent_t **deventp,
 	unsigned int factor;
 	dns_adbfind_t *find;
 	dns_adbaddrinfo_t *addrinfo;
+	isc_socket_t *socket;
 
 	query = *queryp;
 	fctx = query->fctx;
@@ -631,35 +637,48 @@ fctx_cancelquery(resquery_t **queryp, dns_dispatchevent_t **deventp,
 							   0, factor);
 	}
 
-	if (query->dispentry != NULL)
-		dns_dispatch_removeresponse(&query->dispentry, deventp);
-
-	ISC_LIST_UNLINK(fctx->queries, query, link);
-
-	if (query->tsig != NULL)
-		isc_buffer_free(&query->tsig);
-
-	if (query->tsigkey != NULL)
-		dns_tsigkey_detach(&query->tsigkey);
-
 	/*
 	 * Check for any outstanding socket events.  If they exist, cancel
 	 * them and let the event handlers finish the cleanup.  The resolver
 	 * only needs to worry about managing the connect and send events;
 	 * the dispatcher manages the recv events.
 	 */
-	if (RESQUERY_CONNECTING(query))
+	if (RESQUERY_CONNECTING(query)) {
 		/*
 		 * Cancel the connect.
 		 */
-		isc_socket_cancel(query->tcpsocket, NULL,
-				  ISC_SOCKCANCEL_CONNECT);
-	else if (RESQUERY_SENDING(query))
+		if (query->tcpsocket != NULL) {
+			isc_socket_cancel(query->tcpsocket, NULL,
+					  ISC_SOCKCANCEL_CONNECT);
+		} else if (query->dispentry != NULL) {
+			INSIST(query->exclusivesocket);
+			socket = dns_dispatch_getentrysocket(query->dispentry);
+			if (socket != NULL)
+				isc_socket_cancel(socket, NULL,
+						  ISC_SOCKCANCEL_CONNECT);
+		}
+	} else if (RESQUERY_SENDING(query)) {
 		/*
 		 * Cancel the pending send.
 		 */
-		isc_socket_cancel(dns_dispatch_getsocket(query->dispatch),
-				  NULL, ISC_SOCKCANCEL_SEND);
+		if (query->exclusivesocket && query->dispentry != NULL)
+			socket = dns_dispatch_getentrysocket(query->dispentry);
+		else
+			socket = dns_dispatch_getsocket(query->dispatch);
+		if (socket != NULL)
+			isc_socket_cancel(socket, NULL, ISC_SOCKCANCEL_SEND);
+	}
+
+	if (query->dispentry != NULL)
+		dns_dispatch_removeresponse(&query->dispentry, deventp);
+
+	ISC_LIST_UNLINK(fctx->queries, query, link);
+
+	if (query->tsig != NULL)
+		isc_buffer_free(&query->tsig);
+
+	if (query->tsigkey != NULL)
+		dns_tsigkey_detach(&query->tsigkey);
 
 	if (query->dispatch != NULL)
 		dns_dispatch_detach(&query->dispatch);
@@ -824,43 +843,25 @@ fctx_done(fetchctx_t *fctx, isc_result_t result) {
 }
 
 static void
-resquery_senddone(isc_task_t *task, isc_event_t *event) {
+process_sendevent(resquery_t *query, isc_event_t *event) {
 	isc_socketevent_t *sevent = (isc_socketevent_t *)event;
-	resquery_t *query = event->ev_arg;
 	isc_boolean_t retry = ISC_FALSE;
 	isc_result_t result;
 	fetchctx_t *fctx;
 
-	REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);
-
-	QTRACE("senddone");
-
-	/*
-	 * XXXRTH
-	 *
-	 * Currently we don't wait for the senddone event before retrying
-	 * a query.  This means that if we get really behind, we may end
-	 * up doing extra work!
-	 */
-
-	UNUSED(task);
-
-	INSIST(RESQUERY_SENDING(query));
-
-	query->sends--;
 	fctx = query->fctx;
 
 	if (RESQUERY_CANCELED(query)) {
-		if (query->sends == 0) {
+		if (query->sends == 0 && query->connects == 0) {
 			/*
 			 * This query was canceled while the
-			 * isc_socket_sendto() was in progress.
+			 * isc_socket_sendto/connect() was in progress.
 			 */
 			if (query->tcpsocket != NULL)
 				isc_socket_detach(&query->tcpsocket);
 			resquery_destroy(&query);
 		}
-	} else
+	} else {
 		switch (sevent->result) {
 		case ISC_R_SUCCESS:
 			break;
@@ -874,6 +875,7 @@ resquery_senddone(isc_task_t *task, isc_event_t *event) {
 			/*
 			 * No route to remote.
 			 */
+			add_bad(fctx, query->addrinfo, sevent->result);
 			fctx_cancelquery(&query, NULL, NULL, ISC_TRUE);
 			retry = ISC_TRUE;
 			break;
@@ -882,6 +884,7 @@ resquery_senddone(isc_task_t *task, isc_event_t *event) {
 			fctx_cancelquery(&query, NULL, NULL, ISC_FALSE);
 			break;
 		}
+	}
 
 	isc_event_free(&event);
 
@@ -899,6 +902,48 @@ resquery_senddone(isc_task_t *task, isc_event_t *event) {
 	}
 }
 
+static void
+resquery_udpconnected(isc_task_t *task, isc_event_t *event) {
+	resquery_t *query = event->ev_arg;
+
+	REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
+
+	QTRACE("udpconnected");
+
+	UNUSED(task);
+
+	INSIST(RESQUERY_CONNECTING(query));
+
+	query->connects--;
+
+	process_sendevent(query, event);
+}
+
+static void
+resquery_senddone(isc_task_t *task, isc_event_t *event) {
+	resquery_t *query = event->ev_arg;
+
+	REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);
+
+	QTRACE("senddone");
+
+	/*
+	 * XXXRTH
+	 *
+	 * Currently we don't wait for the senddone event before retrying
+	 * a query.  This means that if we get really behind, we may end
+	 * up doing extra work!
+	 */
+
+	UNUSED(task);
+
+	INSIST(RESQUERY_SENDING(query));
+
+	query->sends--;
+
+	process_sendevent(query, event);
+}
+
 static inline isc_result_t
 fctx_addopt(dns_message_t *message, dns_resolver_t *res) {
 	dns_rdataset_t *rdataset;
@@ -1029,6 +1074,7 @@ fctx_query(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
 	 */
 	query->dispatchmgr = res->dispatchmgr;
 	query->dispatch = NULL;
+	query->exclusivesocket = ISC_FALSE;
 	query->tcpsocket = NULL;
 	if ((query->options & DNS_FETCHOPT_TCP) != 0) {
 		isc_sockaddr_t addr;
@@ -1070,50 +1116,21 @@ fctx_query(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo,
 		 * A dispatch will be created once the connect succeeds.
 		 */
 	} else {
-		isc_sockaddr_t localaddr;
-		unsigned int attrs, attrmask;
-		dns_dispatch_t *disp_base;
-
-		attrs = 0;
-		attrs |= DNS_DISPATCHATTR_UDP;
-		attrs |= DNS_DISPATCHATTR_RANDOMPORT;
-
-		attrmask = 0;
-		attrmask |= DNS_DISPATCHATTR_UDP;
-		attrmask |= DNS_DISPATCHATTR_TCP;
-		attrmask |= DNS_DISPATCHATTR_IPV4;
-		attrmask |= DNS_DISPATCHATTR_IPV6;
-
 		switch (isc_sockaddr_pf(&addrinfo->sockaddr)) {
-		case AF_INET:
-			disp_base = res->dispatchv4;
-			attrs |= DNS_DISPATCHATTR_IPV4;
+		case PF_INET:
+			dns_dispatch_attach(res->dispatchv4,
+					    &query->dispatch);
+			query->exclusivesocket = res->exclusivev4;
 			break;
-		case AF_INET6:
-			disp_base = res->dispatchv6;
-			attrs |= DNS_DISPATCHATTR_IPV6;
+		case PF_INET6:
+			dns_dispatch_attach(res->dispatchv6,
+					    &query->dispatch);
+			query->exclusivesocket = res->exclusivev6;
 			break;
 		default:
 			result = ISC_R_NOTIMPLEMENTED;
 			goto cleanup_query;
 		}
-
-		result = dns_dispatch_getlocaladdress(disp_base, &localaddr);
-		if (result != ISC_R_SUCCESS)
-			goto cleanup_query;
-		if (isc_sockaddr_getport(&localaddr) == 0) {
-			result = dns_dispatch_getudp(res->dispatchmgr,
-						     res->socketmgr,
-						     res->taskmgr,
-						     &localaddr,
-						     4096, 1000, 32768,
-						     16411, 16433,
-						     attrs, attrmask,
-						     &query->dispatch);
-			if (result != ISC_R_SUCCESS)
-				goto cleanup_query;
-		} else
-			dns_dispatch_attach(disp_base, &query->dispatch);
 		/*
 		 * We should always have a valid dispatcher here.  If we
 		 * don't support a protocol family, then its dispatcher
@@ -1224,13 +1241,14 @@ resquery_send(resquery_t *query) {
 	/*
 	 * Get a query id from the dispatch.
 	 */
-	result = dns_dispatch_addresponse(query->dispatch,
-					  &query->addrinfo->sockaddr,
-					  task,
-					  resquery_response,
-					  query,
-					  &query->id,
-					  &query->dispentry);
+	result = dns_dispatch_addresponse2(query->dispatch,
+					   &query->addrinfo->sockaddr,
+					   task,
+					   resquery_response,
+					   query,
+					   &query->id,
+					   &query->dispentry,
+					   res->socketmgr);
 	if (result != ISC_R_SUCCESS)
 		goto cleanup_temps;
 
@@ -1412,12 +1430,24 @@ resquery_send(resquery_t *query) {
 	 */
 	dns_message_reset(fctx->qmessage, DNS_MESSAGE_INTENTRENDER);
 
-	socket = dns_dispatch_getsocket(query->dispatch);
+	if (query->exclusivesocket)
+		socket = dns_dispatch_getentrysocket(query->dispentry);
+	else
+		socket = dns_dispatch_getsocket(query->dispatch);
 	/*
 	 * Send the query!
 	 */
-	if ((query->options & DNS_FETCHOPT_TCP) == 0)
+	if ((query->options & DNS_FETCHOPT_TCP) == 0) {
 		address = &query->addrinfo->sockaddr;
+		if (query->exclusivesocket) {
+			result = isc_socket_connect(socket, address, task,
+						    resquery_udpconnected,
+						    query);
+			if (result != ISC_R_SUCCESS)
+				goto cleanup_message;
+			query->connects++;
+		}
+	}
 	isc_buffer_usedregion(buffer, &r);
 
 	/*
@@ -1740,7 +1770,7 @@ add_bad(fetchctx_t *fctx, dns_adbaddrinfo_t *addrinfo, isc_result_t reason) {
 		return;
 
 	if (reason == DNS_R_UNEXPECTEDRCODE &&
-	    fctx->rmessage->opcode == dns_rcode_servfail &&
+	    fctx->rmessage->rcode == dns_rcode_servfail &&
 	    ISFORWARDER(addrinfo))
 		return;
 
@@ -2026,6 +2056,13 @@ fctx_getaddresses(fetchctx_t *fctx) {
 	}
 
 	while (sa != NULL) {
+		if ((isc_sockaddr_pf(sa) == AF_INET &&
+			 fctx->res->dispatchv4 == NULL) ||
+		    (isc_sockaddr_pf(sa) == AF_INET6 &&
+			fctx->res->dispatchv6 == NULL)) {
+				sa = ISC_LIST_NEXT(sa, link);
+				continue;
+		}
 		ai = NULL;
 		result = dns_adb_findaddrinfo(fctx->adb,
 					      sa, &ai, 0);  /* XXXMLG */
@@ -5315,6 +5352,19 @@ resquery_response(isc_task_t *task, isc_event_t *event) {
 			 * There's no hope for this query.
 			 */
 			keep_trying = ISC_TRUE;
+
+			/*
+			 * If this is a network error on an exclusive query
+			 * socket, mark the server as bad so that we won't try
+			 * it for this fetch again.
+			 */
+			if (query->exclusivesocket &&
+			    (devent->result == ISC_R_HOSTUNREACH ||
+			     devent->result == ISC_R_NETUNREACH ||
+			     devent->result == ISC_R_CONNREFUSED ||
+			     devent->result == ISC_R_CANCELED)) {
+				    broken_server = devent->result;
+			}
 		}
 		goto done;
 	}
@@ -5465,12 +5515,17 @@ resquery_response(isc_task_t *task, isc_event_t *event) {
 	 */
 	if (message->rcode != dns_rcode_noerror &&
 	    message->rcode != dns_rcode_nxdomain) {
-		if ((message->rcode == dns_rcode_formerr ||
-		     message->rcode == dns_rcode_notimp ||
-		     message->rcode == dns_rcode_servfail) &&
+		if (((message->rcode == dns_rcode_formerr ||
+		     message->rcode == dns_rcode_notimp) ||
+		    (message->rcode == dns_rcode_servfail &&
+		     dns_message_getopt(message) == NULL)) &&
 		    (query->options & DNS_FETCHOPT_NOEDNS0) == 0) {
 			/*
 			 * It's very likely they don't like EDNS0.
+			 * If the response code is SERVFAIL, also check if the
+			 * response contains an OPT RR and don't cache the
+			 * failure since it can be returned for various other
+			 * reasons.
 			 *
 			 * XXXRTH  We should check if the question
 			 *	   we're asking requires EDNS0, and
@@ -5936,6 +5991,7 @@ dns_resolver_create(dns_view_t *view,
 	isc_result_t result = ISC_R_SUCCESS;
 	unsigned int i, buckets_created = 0;
 	char name[16];
+	unsigned dispattr;
 
 	/*
 	 * Create a resolver.
@@ -5991,11 +6047,20 @@ dns_resolver_create(dns_view_t *view,
 	}
 
 	res->dispatchv4 = NULL;
-	if (dispatchv4 != NULL)
+	if (dispatchv4 != NULL) {
 		dns_dispatch_attach(dispatchv4, &res->dispatchv4);
+		dispattr = dns_dispatch_getattributes(dispatchv4);
+		res->exclusivev4 =
+			ISC_TF((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0);
+	}
+
 	res->dispatchv6 = NULL;
-	if (dispatchv6 != NULL)
+	if (dispatchv6 != NULL) {
 		dns_dispatch_attach(dispatchv6, &res->dispatchv6);
+		dispattr = dns_dispatch_getattributes(dispatchv6);
+		res->exclusivev6 =
+			ISC_TF((dispattr & DNS_DISPATCHATTR_EXCLUSIVE) != 0);
+	}
 
 	res->references = 1;
 	res->exiting = ISC_FALSE;
@@ -6253,12 +6318,12 @@ dns_resolver_shutdown(dns_resolver_t *res) {
 			     fctx != NULL;
 			     fctx = ISC_LIST_NEXT(fctx, link))
 				fctx_shutdown(fctx);
-			if (res->dispatchv4 != NULL) {
+			if (res->dispatchv4 != NULL && !res->exclusivev4) {
 				sock = dns_dispatch_getsocket(res->dispatchv4);
 				isc_socket_cancel(sock, res->buckets[i].task,
 						  ISC_SOCKCANCEL_ALL);
 			}
-			if (res->dispatchv6 != NULL) {
+			if (res->dispatchv6 != NULL && !res->exclusivev6) {
 				sock = dns_dispatch_getsocket(res->dispatchv6);
 				isc_socket_cancel(sock, res->buckets[i].task,
 						  ISC_SOCKCANCEL_ALL);