34 lines
1.0 KiB
Python
34 lines
1.0 KiB
Python
from TftpShared import *
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from TftpPacketTypes import *
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class TftpPacketFactory(object):
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"""This class generates TftpPacket objects."""
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def __init__(self):
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self.classes = {
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1: TftpPacketRRQ,
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2: TftpPacketWRQ,
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3: TftpPacketDAT,
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4: TftpPacketACK,
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5: TftpPacketERR,
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6: TftpPacketOACK
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}
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def create(self, opcode):
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tftpassert(self.classes.has_key(opcode),
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"Unsupported opcode: %d" % opcode)
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packet = self.classes[opcode]()
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logger.debug("packet is %s" % packet)
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return packet
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def parse(self, buffer):
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"""This method is used to parse an existing datagram into its
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corresponding TftpPacket object."""
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logger.debug("parsing a %d byte packet" % len(buffer))
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(opcode,) = struct.unpack("!H", buffer[:2])
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logger.debug("opcode is %d" % opcode)
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packet = self.create(opcode)
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packet.buffer = buffer
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return packet.decode()
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