Bind implementation (#779)

This PR adds supports for the WireGuard userspace implementation
using Bind interface from wireguard-go. 
The newly introduced ICEBind struct implements Bind with UDPMux-based
structs from pion/ice to handle hole punching using ICE.
The core implementation was taken from StdBind of wireguard-go.

The result is a single WireGuard port that is used for host and server reflexive candidates. 
Relay candidates are still handled separately and will be integrated in the following PRs.

ICEBind checks the incoming packets for being STUN or WireGuard ones
and routes them to UDPMux (to handle hole punching) or to WireGuard  respectively.

iface/tun_unix.go

@@ -6,10 +6,13 @@ import (
 	"net"
 	"os"
 
-	log "github.com/sirupsen/logrus"
-	"golang.zx2c4.com/wireguard/conn"
-	"golang.zx2c4.com/wireguard/device"
+	"github.com/pion/transport/v2"
 	"golang.zx2c4.com/wireguard/ipc"
+
+	"github.com/netbirdio/netbird/iface/bind"
+
+	log "github.com/sirupsen/logrus"
+	"golang.zx2c4.com/wireguard/device"
 	"golang.zx2c4.com/wireguard/tun"
 )
 
@@ -18,13 +21,18 @@ type tunDevice struct {
 	address      WGAddress
 	mtu          int
 	netInterface NetInterface
+	iceBind      *bind.ICEBind
+	uapi         net.Listener
+	close        chan struct{}
 }
 
-func newTunDevice(name string, address WGAddress, mtu int) *tunDevice {
+func newTunDevice(name string, address WGAddress, mtu int, transportNet transport.Net) *tunDevice {
 	return &tunDevice{
 		name:    name,
 		address: address,
 		mtu:     mtu,
+		iceBind: bind.NewICEBind(transportNet),
+		close:   make(chan struct{}),
 	}
 }
 
@@ -42,23 +50,38 @@ func (c *tunDevice) DeviceName() string {
 }
 
 func (c *tunDevice) Close() error {
-	if c.netInterface == nil {
-		return nil
+
+	select {
+	case c.close <- struct{}{}:
+	default:
 	}
-	err := c.netInterface.Close()
-	if err != nil {
-		return err
+
+	var err1, err2, err3 error
+	if c.netInterface != nil {
+		err1 = c.netInterface.Close()
+	}
+
+	if c.uapi != nil {
+		err2 = c.uapi.Close()
 	}
 
 	sockPath := "/var/run/wireguard/" + c.name + ".sock"
 	if _, statErr := os.Stat(sockPath); statErr == nil {
 		statErr = os.Remove(sockPath)
 		if statErr != nil {
-			return statErr
+			err3 = statErr
 		}
 	}
 
-	return nil
+	if err1 != nil {
+		return err1
+	}
+
+	if err2 != nil {
+		return err2
+	}
+
+	return err3
 }
 
 // createWithUserspace Creates a new Wireguard interface, using wireguard-go userspace implementation
@@ -69,26 +92,36 @@ func (c *tunDevice) createWithUserspace() (NetInterface, error) {
 	}
 
 	// We need to create a wireguard-go device and listen to configuration requests
-	tunDevice := device.NewDevice(tunIface, conn.NewDefaultBind(), device.NewLogger(device.LogLevelSilent, "[wiretrustee] "))
-	err = tunDevice.Up()
+	tunDev := device.NewDevice(tunIface, c.iceBind, device.NewLogger(device.LogLevelSilent, "[netbird] "))
+	err = tunDev.Up()
 	if err != nil {
-		return tunIface, err
+		_ = tunIface.Close()
+		return nil, err
 	}
 
-	// todo: after this line in case of error close the tunSock
-	uapi, err := c.getUAPI(c.name)
+	c.uapi, err = c.getUAPI(c.name)
 	if err != nil {
-		return tunIface, err
+		_ = tunIface.Close()
+		return nil, err
 	}
 
 	go func() {
 		for {
-			uapiConn, uapiErr := uapi.Accept()
+			select {
+			case <-c.close:
+				log.Debugf("exit uapi.Accept()")
+				return
+			default:
+			}
+			uapiConn, uapiErr := c.uapi.Accept()
 			if uapiErr != nil {
 				log.Traceln("uapi Accept failed with error: ", uapiErr)
 				continue
 			}
-			go tunDevice.IpcHandle(uapiConn)
+			go func() {
+				tunDev.IpcHandle(uapiConn)
+				log.Debugf("exit tunDevice.IpcHandle")
+			}()
 		}
 	}()