rename vtun to tungo

internal/net/dialer/dialer.go

@@ -98,7 +98,7 @@ func (d *Dialer) Dial(ctx context.Context, network, addr string) (conn net.Conn,
 				return
 			}
 
-			log.Debugf("dial %s %v@%s failed: %s", network, ifAddr, ifceName, err)
+			log.Debugf("dial %s/%s via interface %s@%v failed: %s", addr, network, ifceName, ifAddr, err)
 
 			if strict &&
 				!strings.Contains(err.Error(), "no suitable address found") &&
@@ -113,7 +113,7 @@ func (d *Dialer) Dial(ctx context.Context, network, addr string) (conn net.Conn,
 
 func (d *Dialer) 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)
+		log.Debugf("dial %s/%s via interface %s@%s", addr, network, ifceName, ifAddr)
 	}
 
 	switch network {
@@ -135,7 +135,7 @@ func (d *Dialer) dialOnce(ctx context.Context, network, addr, ifceName string, i
 			}
 			err = sc.Control(func(fd uintptr) {
 				if ifceName != "" {
-					if err := bindDevice(fd, ifceName); err != nil {
+					if err := bindDevice(network, fd, ifceName); err != nil {
 						log.Warnf("bind device: %v", err)
 					}
 				}
@@ -159,7 +159,7 @@ func (d *Dialer) dialOnce(ctx context.Context, network, addr, ifceName string, i
 		Control: func(network, address string, c syscall.RawConn) error {
 			return c.Control(func(fd uintptr) {
 				if ifceName != "" {
-					if err := bindDevice(fd, ifceName); err != nil {
+					if err := bindDevice(network, fd, ifceName); err != nil {
 						log.Warnf("bind device: %v", err)
 					}
 				}

internal/net/dialer/dialer_darwin.go

@@ -0,0 +1,32 @@
+package dialer
+
+import (
+	"net"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+func bindDevice(network string, fd uintptr, ifceName string) error {
+	if ifceName == "" {
+		return nil
+	}
+
+	ifce, err := net.InterfaceByName(ifceName)
+	if err == nil {
+		return err
+	}
+
+	switch network {
+	case "tcp", "tcp4", "udp4":
+		return unix.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_BOUND_IF, ifce.Index)
+	case "tcp6", "udp6":
+		return unix.SetsockoptInt(int(fd), syscall.IPPROTO_IPV6, syscall.IPV6_BOUND_IF, ifce.Index)
+	}
+
+	return nil
+}
+
+func setMark(fd uintptr, mark int) error {
+	return nil
+}

internal/net/dialer/dialer_linux.go

@@ -4,7 +4,7 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func bindDevice(fd uintptr, ifceName string) error {
+func bindDevice(network string, fd uintptr, ifceName string) error {
 	if ifceName == "" {
 		return nil
 	}

internal/net/dialer/dialer_other.go

@@ -1,8 +1,8 @@
-//go:build !linux
+//go:build !linux && !windows && !darwin
 
 package dialer
 
-func bindDevice(fd uintptr, ifceName string) error {
+func bindDevice(network string, fd uintptr, ifceName string) error {
 	return nil
 }
 

internal/net/dialer/dialer_windows.go

@@ -0,0 +1,51 @@
+package dialer
+
+import (
+	"encoding/binary"
+	"net"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+const (
+	IP_UNICAST_IF   = 31
+	IPV6_UNICAST_IF = 31
+)
+
+func bindDevice(network string, fd uintptr, ifceName string) error {
+	if ifceName == "" {
+		return nil
+	}
+
+	ifce, err := net.InterfaceByName(ifceName)
+	if err == nil {
+		return err
+	}
+
+	switch network {
+	case "tcp", "tcp4", "udp4":
+		return bindSocketToInterface4(windows.Handle(fd), uint32(ifce.Index))
+	case "tcp6", "udp6":
+		return bindSocketToInterface6(windows.Handle(fd), uint32(ifce.Index))
+	}
+
+	return nil
+}
+
+func setMark(fd uintptr, mark int) error {
+	return nil
+}
+
+func bindSocketToInterface4(handle windows.Handle, index uint32) error {
+	// For IPv4, this parameter must be an interface index in network byte order.
+	// Ref: https://learn.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options
+	var bytes [4]byte
+	binary.BigEndian.PutUint32(bytes[:], index)
+	index = *(*uint32)(unsafe.Pointer(&bytes[0]))
+	return windows.SetsockoptInt(handle, windows.IPPROTO_IP, IP_UNICAST_IF, int(index))
+}
+
+func bindSocketToInterface6(handle windows.Handle, index uint32) error {
+	return windows.SetsockoptInt(handle, windows.IPPROTO_IPV6, IPV6_UNICAST_IF, int(index))
+}