make interface config more modular

1 files changed, 41 insertions, 16 deletions

diff --git a/tuntap/tuntap.go b/tuntap/tuntap.go
index fd3b4ae..19b9bf8 100644
--- a/tuntap/tuntap.go
+++ b/tuntap/tuntap.go
@@ -53,30 +53,45 @@ const (
 type Device struct {
 	iface  *extlib.Interface
 	iftype extlib.DevKind
+	nl     netlink.Link
 }
 
 func (dev *Device) Name() string {
 	return dev.iface.Name()
 }
 
-func (dev *Device) Configure(addr net.IPNet) error {
+func (dev *Device) AddAddress(addr net.IPNet) error {
 	// TODO: this only works on linux...
-	ln, err := netlink.LinkByName(dev.iface.Name())
-	if err != nil {
-		return fmt.Errorf("netlink(open netlink by name) failed: %v", err)
-	}
-	if err = netlink.AddrAdd(ln, &netlink.Addr{IPNet: &addr}); err != nil {
+	if err := netlink.AddrAdd(dev.nl, &netlink.Addr{IPNet: &addr}); err != nil {
 		return fmt.Errorf("netlink(addr add) failed: %v", err)
 	}
-	if err = netlink.LinkSetMTU(ln, 1400); err != nil { // TODO: hardcoded value
+	return nil
+}
+
+func (dev *Device) SetMTU(mtu int) error {
+	// TODO: this only works on linux...
+	if err := netlink.LinkSetMTU(dev.nl, mtu); err != nil {
 		return fmt.Errorf("netlink(link set mtu) failed: %v", err)
 	}
-	if err = netlink.LinkSetUp(ln); err != nil {
+	return nil
+}
+
+func (dev *Device) Up() error {
+	// TODO: this only works on linux...
+	if err := netlink.LinkSetUp(dev.nl); err != nil {
 		return fmt.Errorf("netlink(link set up) failed: %v", err)
 	}
 	return nil
 }
 
+func (dev *Device) Down() error {
+	// TODO: this only works on linux...
+	if err := netlink.LinkSetDown(dev.nl); err != nil {
+		return fmt.Errorf("netlink(link set down) failed: %v", err)
+	}
+	return nil
+}
+
 func (dev *Device) RunPostUp(script string) error {
 	ctx, cancel := context.WithTimeout(context.Background(), PostUpScriptTimeout)
 	defer cancel()
@@ -119,19 +134,29 @@ func NewTapDevice(name string) (dev *Device, err error) {
 func NewDevice(iftype, name string) (dev *Device, err error) {
 	if iftype == "" {
 		if strings.HasPrefix(name, "tun") {
-			return NewTunDevice(name)
-		}
-		if strings.HasPrefix(name, "tap") {
-			return NewTapDevice(name)
+			iftype = "tun"
+		} else if strings.HasPrefix(name, "tap") {
+			iftype = "tap"
+		} else {
+			return nil, fmt.Errorf("no device type is set and the given interface name(%s) doesn't start with 'tun' or 'tap'", name)
 		}
-		return nil, fmt.Errorf("no device type is set and the given interface name(%s) doesn't start with 'tun' or 'tap'", name)
 	}
 
 	switch strings.ToLower(iftype) {
 	case "tun":
-		return NewTunDevice(name)
+		dev, err = NewTunDevice(name)
 	case "tap":
-		return NewTapDevice(name)
+		dev, err = NewTapDevice(name)
+	default:
+		return nil, fmt.Errorf("invalid interface type: %s", iftype)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: this only works on linux...
+	if dev.nl, err = netlink.LinkByName(dev.iface.Name()); err != nil {
+		return nil, fmt.Errorf("netlink(open netlink by name) failed: %v", err)
 	}
-	return nil, fmt.Errorf("invalid interface type: %s", iftype)
+	return dev, nil
 }