'parse the NetBIOS Session Service header [2]'

def parseNetBIOSSessionService(self, data):

    if (len(data) < 4):
        raise InsufficientData
    msgtype = struct.unpack('B', data[0])[0]
    (arg1, arg2, arg3) = struct.unpack('3B', data[1:4])
    mlength = (((arg1 * 512) + (arg2 * 256)) + arg3)
    smbdata = data[4:]
    return (msgtype, mlength, smbdata)
