92 lines
2.6 KiB
Python
92 lines
2.6 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (C) 2016 Fabio Falcinelli, Maximilian Hils
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import struct
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class Header(object):
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def __init__(self, packet, start=0):
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self._packet = packet # type: "pydivert.Packet"
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self._start = start
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@property
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def raw(self):
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"""
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The raw header, possibly including payload.
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"""
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return self._packet.raw[self._start:]
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@raw.setter
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def raw(self, val):
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if len(val) == len(self.raw):
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self.raw[:] = val
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else:
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self._packet.raw = memoryview(bytearray(
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self._packet.raw[:self._start].tobytes() + val
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))
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self._packet.ip.packet_len = len(self._packet.raw)
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def __setattr__(self, key, value):
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if key in dir(self) or key in {"_packet", "_start"}:
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return super(Header, self).__setattr__(key, value)
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raise AttributeError("AttributeError: '{}' object has no attribute '{}'".format(
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type(self).__name__,
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key
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))
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class PayloadMixin(object):
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@property
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def header_len(self):
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raise NotImplementedError() # pragma: no cover
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@property
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def payload(self):
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"""
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The packet payload data.
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"""
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return self.raw[self.header_len:].tobytes()
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@payload.setter
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def payload(self, val):
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if len(val) == len(self.raw) - self.header_len:
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self.raw[self.header_len:] = val
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else:
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self.raw = self.raw[:self.header_len].tobytes() + val
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class PortMixin(object):
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@property
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def src_port(self):
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"""
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The source port.
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"""
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return struct.unpack_from("!H", self.raw, 0)[0]
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@property
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def dst_port(self):
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"""
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The destination port.
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"""
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return struct.unpack_from("!H", self.raw, 2)[0]
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@src_port.setter
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def src_port(self, val):
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self.raw[0:2] = struct.pack("!H", val)
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@dst_port.setter
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def dst_port(self, val):
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self.raw[2:4] = struct.pack("!H", val)
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