def handle(self, pkt, raddress, rport):
        """Handle the packet in response to an ACK, which should be a DAT."""
        if isinstance(pkt, TftpPacketDAT):
            return self.handleDat(pkt)

        # Every other packet type is a problem.
        elif isinstance(pkt, TftpPacketACK):
            # Umm, we ACK, you don't.
            self.sendError(TftpErrors.IllegalTftpOp)
            raise TftpException("Received ACK from peer when expecting DAT")

        elif isinstance(pkt, TftpPacketWRQ):
            self.sendError(TftpErrors.IllegalTftpOp)
            raise TftpException("Received WRQ from peer when expecting DAT")

        elif isinstance(pkt, TftpPacketERR):
            self.sendError(TftpErrors.IllegalTftpOp)
            raise TftpException("Received ERR from peer: " + str(pkt))

        else:
            self.sendError(TftpErrors.IllegalTftpOp)
            raise TftpException("Received unknown packet type from peer: " + str(pkt))
Handle the packet in response to an ACK, which should be a DAT.