refactort: extract method to create Wireguard interface using kernel module

iface/iface.go

@@ -5,5 +5,5 @@ package iface
 // Create Creates a new Wireguard interface, sets a given IP and brings it up.
 // Will reuse an existing one.
 func Create(iface string, address string) error {
-	return CreateInUserspace(iface, address)
+	return CreateWithUserspace(iface, address)
 }

iface/iface_configuration.go

@@ -26,8 +26,8 @@ func ConfigureWithKeyGen(iface string) (*wgtypes.Key, error) {
 	return &key, Configure(iface, key.String())
 }
 
-// CreateInUserspace Creates a new Wireguard interface, using wireguard-go userspace implementation
+// CreateWithUserspace Creates a new Wireguard interface, using wireguard-go userspace implementation
-func CreateInUserspace(iface string, address string) error {
+func CreateWithUserspace(iface string, address string) error {
 	var err error
 	tunIface, err := tun.CreateTUN(iface, defaultMTU)
 	if err != nil {

iface/iface_linux.go

@@ -11,56 +11,62 @@ import (
 func Create(iface string, address string) error {
 
 	if WireguardModExists() {
-		attrs := netlink.NewLinkAttrs()
+		return CreateWithKernel(iface, address)
-		attrs.Name = iface
-
-		link := wgLink{
-			attrs: &attrs,
-		}
-
-		log.Debugf("adding device: %s", iface)
-		err := netlink.LinkAdd(&link)
-		if os.IsExist(err) {
-			log.Infof("interface %s already exists. Will reuse.", iface)
-		} else if err != nil {
-			return err
-		}
-
-		log.Debugf("adding address %s to interface: %s", address, iface)
-		addr, _ := netlink.ParseAddr(address)
-		err = netlink.AddrAdd(&link, addr)
-		if os.IsExist(err) {
-			log.Infof("interface %s already has the address: %s", iface, address)
-		} else if err != nil {
-			return err
-		}
-		err = assignAddr(address, iface)
-		if err != nil {
-			return err
-		}
-
-		// todo do a discovery
-		log.Debugf("setting MTU: %s", iface)
-		err = netlink.LinkSetMTU(&link, defaultMTU)
-		if err != nil {
-			log.Errorf("error setting MTU on interface: %s", iface)
-			return err
-		}
-
-		log.Debugf("bringing up interface: %s", iface)
-		err = netlink.LinkSetUp(&link)
-		if err != nil {
-			log.Errorf("error bringing up interface: %s", iface)
-			return err
-		}
-
-		return nil
 	} else {
-		return CreateInUserspace(iface, address)
+		return CreateWithUserspace(iface, address)
 	}
 
 }
 
+// CreateWithKernel Creates a new Wireguard interface using kernel Wireguard module.
+// Works for Linux and offers much better network performance
+func CreateWithKernel(iface string, address string) error {
+	attrs := netlink.NewLinkAttrs()
+	attrs.Name = iface
+
+	link := wgLink{
+		attrs: &attrs,
+	}
+
+	log.Debugf("adding device: %s", iface)
+	err := netlink.LinkAdd(&link)
+	if os.IsExist(err) {
+		log.Infof("interface %s already exists. Will reuse.", iface)
+	} else if err != nil {
+		return err
+	}
+
+	log.Debugf("adding address %s to interface: %s", address, iface)
+	addr, _ := netlink.ParseAddr(address)
+	err = netlink.AddrAdd(&link, addr)
+	if os.IsExist(err) {
+		log.Infof("interface %s already has the address: %s", iface, address)
+	} else if err != nil {
+		return err
+	}
+	err = assignAddr(address, iface)
+	if err != nil {
+		return err
+	}
+
+	// todo do a discovery
+	log.Debugf("setting MTU: %s", iface)
+	err = netlink.LinkSetMTU(&link, defaultMTU)
+	if err != nil {
+		log.Errorf("error setting MTU on interface: %s", iface)
+		return err
+	}
+
+	log.Debugf("bringing up interface: %s", iface)
+	err = netlink.LinkSetUp(&link)
+	if err != nil {
+		log.Errorf("error bringing up interface: %s", iface)
+		return err
+	}
+
+	return nil
+}
+
 // assignAddr Adds IP address to the tunnel interface
 func assignAddr(address, name string) error {
 	var err error