def _processIncomingPacket(self, packet):
'''
Takes a raw packet, checks it and returns the correct packet class
'''
# Check for special bytes n packet that shouldn't be there
if protocol.START_BYTE in packet or protocol.END_BYTE in packet:
raise ParsingException, 'Unescaped bytes found in packet: %s' % protocols.toHex(packet)
# Process escapes
processed = 0
while protocol.ESCAPE_BYTE in packet[processed:]:
i = packet.index(protocol.ESCAPE_BYTE, processed)
processed = i+1
# Convert escaped byte to an integer to XOR, and then convert back to a string
unescaped = chr(ord(packet[i+1]) ^ 0xFF)
if unescaped in protocol.SPECIAL_BYTES:
packet = packet[:i] + unescaped + packet[i+2:]
else:
raise ParsingException, 'Wrongly escaped byte found in packet (%s): %s' % (hex(ord(unescaped)), protocols.toHex(packet))
if not len(packet):
raise IgnorableParsingException, 'Packet is empty'
if len(packet) < 4:
raise ParsingException, 'Packet does not contain required information. Packet content: %s' % protocols.toHex(packet)
# Split up packet
contents = {
'flags': packet[0],
'payload_id': protocols.shortFrom8bit(packet[1:3]),
'payload': packet[3:-1],
'checksum': packet[-1]
}
# Check checksum
gen_checksum = packetlib.getChecksum(packet[:-1])
if contents['checksum'] != gen_checksum:
raise ParsingException, 'Checksum is incorrect! Provided: %d, generated: %d, packet: [%s]' % (ord(contents['checksum']), ord(gen_checksum), protocols.toHex(packet))
# Create response packet object
response = responses.getPacket(contents['payload_id'])
# Populate data
response.parseHeaderFlags(contents['flags'])
response.setPayloadId(contents['payload_id'])
response.parsePayload(contents['payload'])
response.validate()
return response
def _processIncomingPacket(self, packet):
'''
Takes a raw packet, checks it and returns the correct packet class
'''
contents = {}
contents['flags'] = None
contents['payload_id'] = None
contents['payload'] = []
contents['checksum'] = None
index = 1
# Grab flags
contents['flags'] = flags = packet[index]
index += 1
# Grab payload id
contents['payload_id'] = payload_id = protocols.from8bit(packet[index:index+2])
index += 2
# Grab payload
contents['payload'] = payload = packet[index:(len(packet) - 2)]
index += len(payload)
# Grab checksum
contents['checksum'] = checksum = packet[index]
index += 1
# Check checksum
gen_checksum = packetlib.getChecksum(packet[1:index-1])
if checksum != gen_checksum:
raise ParsingException, 'Checksum is incorrect! Provided: %d, generated: %d' % (checksum, gen_checksum)
# Just double check we only have one byte left
if index != (len(packet) - 1):
raise ParsingException, 'Packet incorrectly processed, %d bytes left' % (len(packet) - 1 - index)
# Create response packet object
response = responses.getPacket(payload_id)
# Populate data
response.parseHeaderFlags(contents['flags'])
response.setPayloadId(contents['payload_id'])
response.parsePayload(contents['payload'])
response.validate()
return response
