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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pre_dissect(self, s):
 """ We need to parse the padding and type as soon as possible, """

        if len(s) < 1:
            raise Exception("Invalid InnerPlaintext (too short).")

        tmp_len = len(s) - 1
        if s[-1] != b"\x00":
            msg_len = tmp_len
        else:
            n = 1
            while s[-n] != b"\x00" and n < tmp_len:
                n += 1
            msg_len = tmp_len - n
        self.fields_desc[0].length_from = lambda pkt: msg_len

        self.type = struct.unpack("B", s[msg_len:msg_len + 1])[0]

        return s