dev_pypacker.py 文件源码

def get_os_mtu(self, iface=None):
        """Get MTU value in host OS.

        Args:
            iface(str):  Interface for getting MTU in host OS

        Returns:
            int: Original MTU value

        Examples::

            env.tg[1].get_os_mtu(iface=ports[('tg1', 'sw1')][1])

        """
        try:
            soc = socket.socket(socket.AF_PACKET, socket.SOCK_RAW)
            ifr = struct.pack('16sH', iface.encode("utf-8"), 0)
            mtu = struct.unpack('16sH', ioctl(soc, self.SIOCGIFMTU, ifr))[1]
        except Exception as err:
            raise PypackerException("ERROR: Getting MTU failed; {}".format(err))

        return mtu