More review feedback.

nameserver/dns.go

@@ -70,14 +70,18 @@ func (d *DNSServer) listen(address string) error {
 	if err != nil {
 		return err
 	}
-	udpServer := &dns.Server{PacketConn: udpListener, Handler: d.createHandler(d.udpClient, minUDPSize)}
+	udpMux := dns.NewServeMux()
+	d.createHandler(d.udpClient, minUDPSize, udpMux)
+	udpServer := &dns.Server{PacketConn: udpListener, Handler: udpMux}
 
 	tcpListener, err := net.Listen("tcp", address)
 	if err != nil {
 		udpServer.Shutdown()
 		return err
 	}
-	tcpServer := &dns.Server{Listener: tcpListener, Handler: d.createHandler(d.tcpClient, -1)}
+	tcpMux := dns.NewServeMux()
+	d.createHandler(d.tcpClient, -1, tcpMux)
+	tcpServer := &dns.Server{Listener: tcpListener, Handler: tcpMux}
 
 	d.servers = []*dns.Server{udpServer, tcpServer}
 	return nil
@@ -114,21 +118,19 @@ func (d *DNSServer) errorResponse(r *dns.Msg, code int, w dns.ResponseWriter) {
 
 type handler struct {
 	*DNSServer
-	*dns.ServeMux
 	maxResponseSize int
 	client          *dns.Client
 }
 
-func (d *DNSServer) createHandler(client *dns.Client, defaultMaxResponseSize int) *handler {
+func (d *DNSServer) createHandler(client *dns.Client, defaultMaxResponseSize int, mux *dns.ServeMux) *handler {
 	h := &handler{
-		ServeMux:        dns.NewServeMux(),
 		DNSServer:       d,
 		maxResponseSize: defaultMaxResponseSize,
 		client:          client,
 	}
-	h.HandleFunc(d.domain, h.handleLocal)
-	h.HandleFunc(reverseDNSdomain, h.handleReverse)
-	h.HandleFunc(topDomain, h.handleRecursive)
+	mux.HandleFunc(d.domain, h.handleLocal)
+	mux.HandleFunc(reverseDNSdomain, h.handleReverse)
+	mux.HandleFunc(topDomain, h.handleRecursive)
 	return h
 }