Phillip/483 ipv6 bug (#491)

* fix 2 bugs in populating transport mode and extractGlue

* push for remote testing

* pr cleanup

* sort imports

---------

Co-authored-by: Zakir Durumeric <zakird@gmail.com>

src/cli/worker_manager.go

@@ -235,6 +235,11 @@ func populateResolverConfig(gc *CLIConf) *zdns.ResolverConfig {
 			log.Fatal("unable to parse blacklist file: ", err)
 		}
 	}
+	// This must occur after setting the DNSConfigFilePath above, so that ZDNS knows where to fetch the DNS Config
+	config, err := populateIPTransportMode(gc, config)
+	if err != nil {
+		log.Fatal("could not populate IP transport mode: ", err)
+	}
 	// This is used in extractAuthorities where we need to know whether to request A or AAAA records to continue iteration
 	// Must be set after populating IPTransportMode
 	if config.IPVersionMode == zdns.IPv4Only {
@@ -250,11 +255,6 @@ func populateResolverConfig(gc *CLIConf) *zdns.ResolverConfig {
 	} else {
 		config.IterationIPPreference = zdns.GetIterationIPPreference(gc.PreferIPv4Iteration, gc.PreferIPv6Iteration)
 	}
-	// This must occur after setting the DNSConfigFilePath above, so that ZDNS knows where to fetch the DNS Config
-	config, err := populateIPTransportMode(gc, config)
-	if err != nil {
-		log.Fatal("could not populate IP transport mode: ", err)
-	}
 	// This must occur after setting IPTransportMode, so that ZDNS knows whether to use IPv4 or IPv6 nameservers
 	config, err = populateNameServers(gc, config)
 	if err != nil {

src/zdns/lookup.go

@@ -913,7 +913,9 @@ func (r *Resolver) cachedLookup(ctx context.Context, q Question, nameServer *Nam
 	if err != nil {
 		return &SingleQueryResult{}, isCached, status, trace, errors.Wrap(err, "could not perform lookup")
 	}
-	r.verboseLog(depth+2, "Results from wire for name: ", q, ", Layer: ", layer, ", Nameserver: ", nameServer, " status: ", status, " , err: ", err, " result: ", *result)
+	if result != nil {
+		r.verboseLog(depth+2, "Results from wire for name: ", q, ", Layer: ", layer, ", Nameserver: ", nameServer, " status: ", status, " , err: ", err, " result: ", *result)
+	}
 
 	if status == StatusNoError && result != nil {
 		if r.shouldValidateDNSSEC {
@@ -1169,12 +1171,18 @@ func wireLookupUDP(ctx context.Context, connInfo *ConnectionInfo, q Question, na
 
 	var r *dns.Msg
 	var err error
+
 	if connInfo.udpConn != nil {
-		dst, _ := net.ResolveUDPAddr("udp", nameServer.String())
+		var dst *net.UDPAddr
+		dst, err = net.ResolveUDPAddr("udp", nameServer.String())
+		if err != nil {
+			return nil, nil, StatusError, errors.Wrapf(err, "could not resolve UDP address %s", nameServer.String())
+		}
 		r, _, err = connInfo.udpClient.ExchangeWithConnToContext(ctx, m, connInfo.udpConn, dst)
 	} else {
 		r, _, err = connInfo.udpClient.ExchangeContext(ctx, m, nameServer.String())
 	}
+
 	if r != nil && (r.Truncated || r.Rcode == dns.RcodeBadTrunc) {
 		return &res, r, StatusTruncated, err
 	}
@@ -1323,16 +1331,13 @@ func (r *Resolver) extractAuthority(ctx context.Context, authority interface{},
 	// that would normally be cache poison. Because it's "ok" and quite common
 	res, status := checkGlue(server, result, r.ipVersionMode, r.iterationIPPreference)
 	if status != StatusNoError {
-		//if ok, _ = nameIsBeneath(server, layer); ok {
-		//	// Glue is optional, so if we don't have it try to lookup the server directly
-		//	// Terminating
-		//	return nil, StatusNoNeededGlue, "", trace
-		//}
 		// Fall through to normal query
 		var q QuestionWithMetadata
 		q.Q.Name = server
 		q.Q.Class = dns.ClassINET
-		if r.ipVersionMode != IPv4Only && r.iterationIPPreference == PreferIPv6 {
+		if r.ipVersionMode == IPv6Only {
+			q.Q.Type = dns.TypeAAAA
+		} else if r.ipVersionMode == IPv4OrIPv6 && r.iterationIPPreference == PreferIPv6 {
 			q.Q.Type = dns.TypeAAAA
 		} else {
 			q.Q.Type = dns.TypeA
@@ -1363,6 +1368,7 @@ func (r *Resolver) extractAuthority(ctx context.Context, authority interface{},
 				parsedIPString := strings.TrimSuffix(innerAns.Answer, ".")
 				ns.IP = net.ParseIP(parsedIPString)
 				ns.PopulateDefaultPort(r.dnsOverTLSEnabled, r.dnsOverHTTPSEnabled)
+				ns.DomainName = server
 				return ns, StatusNoError, layer, trace
 			}
 		}