}

// Interfaces returns a list of the system's network interfaces.
func Interfaces() ([]Interface, error) {
	ift, err := interfaceTable(0)
	if err != nil {
		return nil, &OpError{Op: "route", Net: "ip+net", Source: nil, Addr: nil, Err: err}
	}
	if len(ift) != 0 {
		zoneCache.update(ift, false)
	}
	return ift, nil
}

// InterfaceAddrs returns a list of the system's unicast interface
// addresses.
//

}

// LoopbackInterface returns an available logical network interface
// for loopback test.
func LoopbackInterface() (*net.Interface, error) {
	ift, err := net.Interfaces()
	if err != nil {
		return nil, errNoAvailableInterface
	}
	for _, ifi := range ift {
		if ifi.Flags&net.FlagLoopback != 0 && ifi.Flags&net.FlagUp != 0 {
			return &ifi, nil
		}
	}
	return nil, errNoAvailableInterface
}