Update udp mux code

iface/bind/udp_mux.go

@@ -223,6 +223,10 @@ func (m *UDPMuxDefault) GetListenAddresses() []net.Addr {
 // GetConn returns a PacketConn given the connection's ufrag and network address
 // creates the connection if an existing one can't be found
 func (m *UDPMuxDefault) GetConn(ufrag string, addr net.Addr) (net.PacketConn, error) {
+	// don't check addr for mux using unspecified address
+	if len(m.localAddrsForUnspecified) == 0 && m.params.UDPConn.LocalAddr().String() != addr.String() {
+		return nil, fmt.Errorf("invalid address %s", addr.String())
+	}
 
 	var isIPv6 bool
 	if udpAddr, _ := addr.(*net.UDPAddr); udpAddr != nil && udpAddr.IP.To4() == nil {
@@ -281,15 +285,7 @@ func (m *UDPMuxDefault) RemoveConnByUfrag(ufrag string) {
 	for _, c := range removedConns {
 		addresses := c.getAddresses()
 		for _, addr := range addresses {
-			if connList, ok := m.addressMap[addr]; ok {
-				var newList []*udpMuxedConn
-				for _, conn := range connList {
-					if conn.params.Key != ufrag {
-						newList = append(newList, conn)
-					}
-				}
-				m.addressMap[addr] = newList
-			}
+			delete(m.addressMap, addr)
 		}
 	}
 }

iface/bind/udp_mux_universal.go

@@ -80,13 +80,13 @@ func (m *UniversalUDPMuxDefault) ReadFromConn(ctx context.Context) {
 			log.Debugf("stopped reading from the UDPConn due to finished context")
 			return
 		default:
-			_, a, err := m.params.UDPConn.ReadFrom(buf)
+			n, a, err := m.params.UDPConn.ReadFrom(buf)
 			if err != nil {
 				log.Errorf("error while reading packet: %s", err)
 				continue
 			}
 			msg := &stun.Message{
-				Raw: buf,
+				Raw: append([]byte{}, buf[:n]...),
 			}
 			err = msg.Decode()
 			if err != nil {