diff --git a/common/net/addr.go b/common/net/addr.go
new file mode 100644
index 0000000..bf379d1
--- /dev/null
+++ b/common/net/addr.go
@@ -0,0 +1,84 @@
+package net
+
+import (
+	"fmt"
+	"net"
+)
+
+func ParseInterfaceAddr(ifceName, network string) (ifce string, addr []net.Addr, err error) {
+	if ifceName == "" {
+		addr = append(addr, nil)
+		return
+	}
+
+	ip := net.ParseIP(ifceName)
+	if ip == nil {
+		var ife *net.Interface
+		ife, err = net.InterfaceByName(ifceName)
+		if err != nil {
+			return
+		}
+		var addrs []net.Addr
+		addrs, err = ife.Addrs()
+		if err != nil {
+			return
+		}
+		if len(addrs) == 0 {
+			err = fmt.Errorf("addr not found for interface %s", ifceName)
+			return
+		}
+		ifce = ifceName
+		for _, addr_ := range addrs {
+			if ipNet, ok := addr_.(*net.IPNet); ok {
+				addr = append(addr, ipToAddr(ipNet.IP, network))
+			}
+		}
+	} else {
+		ifce, err = findInterfaceByIP(ip)
+		if err != nil {
+			return
+		}
+		addr = []net.Addr{ipToAddr(ip, network)}
+	}
+
+	return
+}
+
+func ipToAddr(ip net.IP, network string) (addr net.Addr) {
+	port := 0
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		addr = &net.TCPAddr{IP: ip, Port: port}
+		return
+	case "udp", "udp4", "udp6":
+		addr = &net.UDPAddr{IP: ip, Port: port}
+		return
+	default:
+		addr = &net.IPAddr{IP: ip}
+		return
+	}
+}
+
+func findInterfaceByIP(ip net.IP) (string, error) {
+	ifces, err := net.Interfaces()
+	if err != nil {
+		return "", err
+	}
+	for _, ifce := range ifces {
+		addrs, _ := ifce.Addrs()
+		if len(addrs) == 0 {
+			continue
+		}
+		for _, addr := range addrs {
+			ipAddr, _ := addr.(*net.IPNet)
+			if ipAddr == nil {
+				continue
+			}
+			// logger.Default().Infof("%s-%s", ipAddr, ip)
+			if ipAddr.IP.Equal(ip) {
+				return ifce.Name, nil
+			}
+		}
+	}
+	return "", nil
+}
diff --git a/common/net/dialer/dialer.go b/common/net/dialer/dialer.go
index 0a85e32..36fe0c7 100644
--- a/common/net/dialer/dialer.go
+++ b/common/net/dialer/dialer.go
@@ -8,6 +8,7 @@ import (
 	"syscall"
 	"time"
 
+	xnet "github.com/go-gost/core/common/net"
 	"github.com/go-gost/core/logger"
 )
 
@@ -28,6 +29,58 @@ type NetDialer struct {
 	deadline  time.Time
 }
 
+func (d *NetDialer) Dial(ctx context.Context, network, addr string) (conn net.Conn, err error) {
+	if d == nil {
+		d = DefaultNetDialer
+	}
+	if d.Timeout <= 0 {
+		d.Timeout = DefaultTimeout
+	}
+
+	if d.DialFunc != nil {
+		return d.DialFunc(ctx, network, addr)
+	}
+
+	log := d.Logger
+	if log == nil {
+		log = logger.Default()
+	}
+
+	ifces := strings.Split(d.Interface, ",")
+	d.deadline = time.Now().Add(d.Timeout)
+	for _, ifce := range ifces {
+		strict := strings.HasSuffix(ifce, "!")
+		ifce = strings.TrimSuffix(ifce, "!")
+		var ifceName string
+		var ifAddrs []net.Addr
+		ifceName, ifAddrs, err = xnet.ParseInterfaceAddr(ifce, network)
+		if err != nil && strict {
+			return
+		}
+
+		for _, ifAddr := range ifAddrs {
+			conn, err = d.dialOnce(ctx, network, addr, ifceName, ifAddr, log)
+			if err == nil {
+				return
+			}
+
+			log.Debugf("dial %s %v@%s failed: %s", network, ifAddr, ifceName, err)
+
+			if strict &&
+				!strings.Contains(err.Error(), "no suitable address found") &&
+				!strings.Contains(err.Error(), "mismatched local address type") {
+				return
+			}
+
+			if time.Until(d.deadline) < 0 {
+				return
+			}
+		}
+	}
+
+	return
+}
+
 func (d *NetDialer) dialOnce(ctx context.Context, network, addr, ifceName string, ifAddr net.Addr, log logger.Logger) (net.Conn, error) {
 	if ifceName != "" {
 		log.Debugf("interface: %s %v/%s", ifceName, ifAddr, network)
@@ -91,133 +144,3 @@ func (d *NetDialer) dialOnce(ctx context.Context, network, addr, ifceName string
 	}
 	return netd.DialContext(ctx, network, addr)
 }
-
-func (d *NetDialer) Dial(ctx context.Context, network, addr string) (conn net.Conn, err error) {
-	if d == nil {
-		d = DefaultNetDialer
-	}
-	if d.Timeout <= 0 {
-		d.Timeout = DefaultTimeout
-	}
-
-	if d.DialFunc != nil {
-		return d.DialFunc(ctx, network, addr)
-	}
-
-	log := d.Logger
-	if log == nil {
-		log = logger.Default()
-	}
-
-	ifces := strings.Split(d.Interface, ",")
-	d.deadline = time.Now().Add(d.Timeout)
-	for _, ifce := range ifces {
-		strict := strings.HasSuffix(ifce, "!")
-		ifce = strings.TrimSuffix(ifce, "!")
-		var ifceName string
-		var ifAddrs []net.Addr
-		ifceName, ifAddrs, err = parseInterfaceAddr(ifce, network)
-		if err != nil && strict {
-			return
-		}
-
-		for _, ifAddr := range ifAddrs {
-			conn, err = d.dialOnce(ctx, network, addr, ifceName, ifAddr, log)
-			if err == nil {
-				return
-			}
-
-			log.Debugf("dial %s %v@%s failed: %s", network, ifAddr, ifceName, err)
-
-			if strict &&
-				!strings.Contains(err.Error(), "no suitable address found") &&
-				!strings.Contains(err.Error(), "mismatched local address type") {
-				return
-			}
-
-			if time.Until(d.deadline) < 0 {
-				return
-			}
-		}
-	}
-
-	return
-}
-
-func ipToAddr(ip net.IP, network string) (addr net.Addr) {
-	port := 0
-	switch network {
-	case "tcp", "tcp4", "tcp6":
-		addr = &net.TCPAddr{IP: ip, Port: port}
-		return
-	case "udp", "udp4", "udp6":
-		addr = &net.UDPAddr{IP: ip, Port: port}
-		return
-	default:
-		addr = &net.IPAddr{IP: ip}
-		return
-	}
-}
-
-func parseInterfaceAddr(ifceName, network string) (ifce string, addr []net.Addr, err error) {
-	if ifceName == "" {
-		addr = append(addr, nil)
-		return
-	}
-
-	ip := net.ParseIP(ifceName)
-	if ip == nil {
-		var ife *net.Interface
-		ife, err = net.InterfaceByName(ifceName)
-		if err != nil {
-			return
-		}
-		var addrs []net.Addr
-		addrs, err = ife.Addrs()
-		if err != nil {
-			return
-		}
-		if len(addrs) == 0 {
-			err = fmt.Errorf("addr not found for interface %s", ifceName)
-			return
-		}
-		ifce = ifceName
-		for _, addr_ := range addrs {
-			if ipNet, ok := addr_.(*net.IPNet); ok {
-				addr = append(addr, ipToAddr(ipNet.IP, network))
-			}
-		}
-	} else {
-		ifce, err = findInterfaceByIP(ip)
-		if err != nil {
-			return
-		}
-		addr = []net.Addr{ipToAddr(ip, network)}
-	}
-
-	return
-}
-
-func findInterfaceByIP(ip net.IP) (string, error) {
-	ifces, err := net.Interfaces()
-	if err != nil {
-		return "", err
-	}
-	for _, ifce := range ifces {
-		addrs, _ := ifce.Addrs()
-		if len(addrs) == 0 {
-			continue
-		}
-		for _, addr := range addrs {
-			ipAddr, _ := addr.(*net.IPNet)
-			if ipAddr == nil {
-				continue
-			}
-			// logger.Default().Infof("%s-%s", ipAddr, ip)
-			if ipAddr.IP.Equal(ip) {
-				return ifce.Name, nil
-			}
-		}
-	}
-	return "", nil
-}