@@ -20,6 +20,7 @@ const (

 var (

 	ErrIptablesNotFound = errors.New("Iptables not found")

 	nat                 = []string{"-t", "nat"}

+	supportsXlock       = false

 )

 type Chain struct {

@@ -27,6 +28,10 @@ type Chain struct {

 	Bridge string

 }

+func init() {

+	supportsXlock = exec.Command("iptables", "--wait", "-L", "-n").Run() == nil

+}

+

 func NewChain(name, bridge string) (*Chain, error) {

 	if output, err := Raw("-t", "nat", "-N", name); err != nil {

 		return nil, err

@@ -147,12 +152,19 @@ func Raw(args ...string) ([]byte, error) {

 	if err != nil {

 		return nil, ErrIptablesNotFound

 	}

+

+	if supportsXlock {

+		args = append([]string{"--wait"}, args...)

+	}

+

 	if os.Getenv("DEBUG") != "" {

 		fmt.Printf("[DEBUG] [iptables]: %s, %v\n", path, args)

 	}

-	output, err := exec.Command(path, append([]string{"--wait"}, args...)...).CombinedOutput()

+

+	output, err := exec.Command(path, args...).CombinedOutput()

 	if err != nil {

 		return nil, fmt.Errorf("iptables failed: iptables %v: %s (%s)", strings.Join(args, " "), output, err)

 	}

+

 	return output, err

 }