def find_message(self):
        '''find the next valid message'''
        while True:
            self.msg = self.mlog.recv_match(condition=args.condition)
            if self.msg is not None and self.msg.get_type() != 'BAD_DATA':
                break
            if self.mlog.f.tell() > self.filesize - 10:
                self.paused = True
                break
        self.last_timestamp = getattr(self.msg, '_timestamp')
find the next valid message