[client] Destory WG interface on down timeout (#2435)

wait on engine down to not only wait for the interface to be down but completely removed. If the waiting loop reaches the timeout we will trigger an interface destroy. On the up command, it now waits until the engine is fully running before sending the response to the CLI. Includes a small refactor of probes to comply with sonar rules about parameter count in the function call

iface/iface.go

@@ -124,7 +124,23 @@ func (w *WGIface) RemoveAllowedIP(peerKey string, allowedIP string) error {
 func (w *WGIface) Close() error {
 	w.mu.Lock()
 	defer w.mu.Unlock()
-	return w.tun.Close()
+
+	err := w.tun.Close()
+	if err != nil {
+		return fmt.Errorf("failed to close wireguard interface %s: %w", w.Name(), err)
+	}
+
+	err = w.waitUntilRemoved()
+	if err != nil {
+		log.Warnf("failed to remove WireGuard interface %s: %v", w.Name(), err)
+		err = w.Destroy()
+		if err != nil {
+			return fmt.Errorf("failed to remove WireGuard interface %s: %w", w.Name(), err)
+		}
+		log.Infof("interface %s successfully removed", w.Name())
+	}
+
+	return nil
 }
 
 // SetFilter sets packet filters for the userspace implementation
@@ -163,3 +179,30 @@ func (w *WGIface) GetDevice() *DeviceWrapper {
 func (w *WGIface) GetStats(peerKey string) (WGStats, error) {
 	return w.configurer.getStats(peerKey)
 }
+
+func (w *WGIface) waitUntilRemoved() error {
+	maxWaitTime := 5 * time.Second
+	timeout := time.NewTimer(maxWaitTime)
+	defer timeout.Stop()
+
+	for {
+		iface, err := net.InterfaceByName(w.Name())
+		if err != nil {
+			if _, ok := err.(*net.OpError); ok {
+				log.Infof("interface %s has been removed", w.Name())
+				return nil
+			}
+			log.Debugf("failed to get interface by name %s: %v", w.Name(), err)
+		} else if iface == nil {
+			log.Infof("interface %s has been removed", w.Name())
+			return nil
+		}
+
+		select {
+		case <-timeout.C:
+			return fmt.Errorf("timeout when waiting for interface %s to be removed", w.Name())
+		default:
+			time.Sleep(100 * time.Millisecond)
+		}
+	}
+}

iface/iface_destroy_bsd.go

@@ -0,0 +1,17 @@
+//go:build darwin || dragonfly || freebsd || netbsd || openbsd
+
+package iface
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+func (w *WGIface) Destroy() error {
+	out, err := exec.Command("ifconfig", w.Name(), "destroy").CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to remove interface %s: %w - %s", w.Name(), err, out)
+	}
+
+	return nil
+}

iface/iface_destroy_linux.go

@@ -0,0 +1,22 @@
+//go:build linux && !android
+
+package iface
+
+import (
+	"fmt"
+
+	"github.com/vishvananda/netlink"
+)
+
+func (w *WGIface) Destroy() error {
+	link, err := netlink.LinkByName(w.Name())
+	if err != nil {
+		return fmt.Errorf("failed to get link by name %s: %w", w.Name(), err)
+	}
+
+	if err := netlink.LinkDel(link); err != nil {
+		return fmt.Errorf("failed to delete link %s: %w", w.Name(), err)
+	}
+
+	return nil
+}

iface/iface_destroy_mobile.go

@@ -0,0 +1,9 @@
+//go:build android || (ios && !darwin)
+
+package iface
+
+import "errors"
+
+func (w *WGIface) Destroy() error {
+	return errors.New("not supported on mobile")
+}

iface/iface_destroy_windows.go

@@ -0,0 +1,32 @@
+//go:build windows
+
+package iface
+
+import (
+	"fmt"
+	"os/exec"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func (w *WGIface) Destroy() error {
+	netshCmd := GetSystem32Command("netsh")
+	out, err := exec.Command(netshCmd, "interface", "set", "interface", w.Name(), "admin=disable").CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to remove interface %s: %w - %s", w.Name(), err, out)
+	}
+	return nil
+}
+
+// GetSystem32Command checks if a command can be found in the system path and returns it. In case it can't find it
+// in the path it will return the full path of a command assuming C:\windows\system32 as the base path.
+func GetSystem32Command(command string) string {
+	_, err := exec.LookPath(command)
+	if err == nil {
+		return command
+	}
+
+	log.Tracef("Command %s not found in PATH, using C:\\windows\\system32\\%s.exe path", command, command)
+
+	return "C:\\windows\\system32\\" + command + ".exe"
+}

iface/tun_darwin.go

@@ -3,6 +3,7 @@
 package iface
 
 import (
+	"fmt"
 	"os/exec"
 
 	"github.com/pion/transport/v3"
@@ -41,7 +42,7 @@ func newTunDevice(name string, address WGAddress, port int, key string, mtu int,
 func (t *tunDevice) Create() (wgConfigurer, error) {
 	tunDevice, err := tun.CreateTUN(t.name, t.mtu)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
 	t.wrapper = newDeviceWrapper(tunDevice)
 
@@ -55,7 +56,7 @@ func (t *tunDevice) Create() (wgConfigurer, error) {
 	err = t.assignAddr()
 	if err != nil {
 		t.device.Close()
-		return nil, err
+		return nil, fmt.Errorf("error assigning ip: %s", err)
 	}
 
 	t.configurer = newWGUSPConfigurer(t.device, t.name)
@@ -63,7 +64,7 @@ func (t *tunDevice) Create() (wgConfigurer, error) {
 	if err != nil {
 		t.device.Close()
 		t.configurer.close()
-		return nil, err
+		return nil, fmt.Errorf("error configuring interface: %s", err)
 	}
 	return t.configurer, nil
 }

iface/tun_kernel_unix.go

@@ -70,7 +70,7 @@ func (t *tunKernelDevice) Create() (wgConfigurer, error) {
 	configurer := newWGConfigurer(t.name)
 
 	if err := configurer.configureInterface(t.key, t.wgPort); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error configuring interface: %s", err)
 	}
 
 	return configurer, nil

iface/tun_netstack.go

@@ -47,7 +47,7 @@ func (t *tunNetstackDevice) Create() (wgConfigurer, error) {
 	t.nsTun = netstack.NewNetStackTun(t.listenAddress, t.address.IP.String(), t.mtu)
 	tunIface, err := t.nsTun.Create()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
 	t.wrapper = newDeviceWrapper(tunIface)
 
@@ -61,7 +61,7 @@ func (t *tunNetstackDevice) Create() (wgConfigurer, error) {
 	err = t.configurer.configureInterface(t.key, t.port)
 	if err != nil {
 		_ = tunIface.Close()
-		return nil, err
+		return nil, fmt.Errorf("error configuring interface: %s", err)
 	}
 
 	log.Debugf("device has been created: %s", t.name)

iface/tun_usp_unix.go

@@ -48,8 +48,8 @@ func (t *tunUSPDevice) Create() (wgConfigurer, error) {
 	log.Info("create tun interface")
 	tunIface, err := tun.CreateTUN(t.name, t.mtu)
 	if err != nil {
-		log.Debugf("failed to create tun unterface (%s, %d): %s", t.name, t.mtu, err)
-		return nil, err
+		log.Debugf("failed to create tun interface (%s, %d): %s", t.name, t.mtu, err)
+		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
 	t.wrapper = newDeviceWrapper(tunIface)
 
@@ -63,7 +63,7 @@ func (t *tunUSPDevice) Create() (wgConfigurer, error) {
 	err = t.assignAddr()
 	if err != nil {
 		t.device.Close()
-		return nil, err
+		return nil, fmt.Errorf("error assigning ip: %s", err)
 	}
 
 	t.configurer = newWGUSPConfigurer(t.device, t.name)
@@ -71,7 +71,7 @@ func (t *tunUSPDevice) Create() (wgConfigurer, error) {
 	if err != nil {
 		t.device.Close()
 		t.configurer.close()
-		return nil, err
+		return nil, fmt.Errorf("error configuring interface: %s", err)
 	}
 	return t.configurer, nil
 }

iface/tun_windows.go

@@ -59,7 +59,7 @@ func (t *tunDevice) Create() (wgConfigurer, error) {
 	log.Info("create tun interface")
 	tunDevice, err := tun.CreateTUNWithRequestedGUID(t.name, &guid, t.mtu)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error creating tun device: %s", err)
 	}
 	t.nativeTunDevice = tunDevice.(*tun.NativeTun)
 	t.wrapper = newDeviceWrapper(tunDevice)
@@ -89,7 +89,7 @@ func (t *tunDevice) Create() (wgConfigurer, error) {
 	err = t.assignAddr()
 	if err != nil {
 		t.device.Close()
-		return nil, err
+		return nil, fmt.Errorf("error assigning ip: %s", err)
 	}
 
 	t.configurer = newWGUSPConfigurer(t.device, t.name)
@@ -97,7 +97,7 @@ func (t *tunDevice) Create() (wgConfigurer, error) {
 	if err != nil {
 		t.device.Close()
 		t.configurer.close()
-		return nil, err
+		return nil, fmt.Errorf("error configuring interface: %s", err)
 	}
 	return t.configurer, nil
 }