diff --git a/tunnel/tcp.go b/tunnel/tcp.go
index a1f7aff..e0c03b1 100755
--- a/tunnel/tcp.go
+++ b/tunnel/tcp.go
@@ -3,7 +3,6 @@ package tunnel
 import (
 	"io"
 	"net"
-	"strconv"
 	"sync"
 	"time"
 
@@ -45,10 +44,7 @@ func handleTCP(localConn core.TCPConn) {
 		metadata.MidIP = dialerAddr.IP
 		metadata.MidPort = uint16(dialerAddr.Port)
 	} else { /* fallback */
-		ip, p, _ := net.SplitHostPort(targetConn.LocalAddr().String())
-		port, _ := strconv.ParseUint(p, 10, 16)
-		metadata.MidIP = net.ParseIP(ip)
-		metadata.MidPort = uint16(port)
+		metadata.MidIP, metadata.MidPort = parseAddr(targetConn.LocalAddr().String())
 	}
 
 	targetConn = newTCPTracker(targetConn, metadata)
diff --git a/tunnel/tunnel.go b/tunnel/tunnel.go
index cb3e389..1402066 100755
--- a/tunnel/tunnel.go
+++ b/tunnel/tunnel.go
@@ -39,13 +39,6 @@ func AddPacket(packet core.UDPPacket) {
 	}
 }
 
-func max(a, b int) int {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 func process() {
 	for i := 0; i < _numUDPWorkers; i++ {
 		queue := _udpQueue
diff --git a/tunnel/udp.go b/tunnel/udp.go
index f9bac4d..03b3e76 100755
--- a/tunnel/udp.go
+++ b/tunnel/udp.go
@@ -4,7 +4,6 @@ import (
 	"errors"
 	"net"
 	"os"
-	"strconv"
 	"time"
 
 	"github.com/xjasonlyu/tun2socks/common/pool"
@@ -88,10 +87,7 @@ func handleUDP(packet core.UDPPacket) {
 			metadata.MidIP = dialerAddr.IP
 			metadata.MidPort = uint16(dialerAddr.Port)
 		} else { /* fallback */
-			ip, p, _ := net.SplitHostPort(pc.LocalAddr().String())
-			port, _ := strconv.ParseUint(p, 10, 16)
-			metadata.MidIP = net.ParseIP(ip)
-			metadata.MidPort = uint16(port)
+			metadata.MidIP, metadata.MidPort = parseAddr(pc.LocalAddr().String())
 		}
 
 		pc = newUDPTracker(pc, metadata)
diff --git a/tunnel/util.go b/tunnel/util.go
new file mode 100644
index 0000000..c7b7f7c
--- /dev/null
+++ b/tunnel/util.go
@@ -0,0 +1,20 @@
+package tunnel
+
+import (
+	"net"
+	"strconv"
+)
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+// parseAddr parses address to IP and port.
+func parseAddr(addr string) (net.IP, uint16) {
+	host, portStr, _ := net.SplitHostPort(addr)
+	portInt, _ := strconv.ParseUint(portStr, 10, 16)
+	return net.ParseIP(host), uint16(portInt)
+}