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import time |
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from queue import Queue |
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from struct import unpack, error |
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from threading import Thread, Event |
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from libAnt.drivers.driver import Driver |
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from libAnt.loggers.logger import Logger |
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class PcapDriver(Driver): |
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def __init__(self, pcap : str, logger: Logger = None): |
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super().__init__(logger=logger) |
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self._isopen = False |
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self._pcap = pcap |
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self._buffer = Queue() |
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self._loop = None |
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class PcapLoop(Thread): |
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def __init__(self, pcap, buffer: Queue): |
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super().__init__() |
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self._stopper = Event() |
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self._pcap = pcap |
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self._buffer = buffer |
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def stop(self) -> None: |
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self._stopper.set() |
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def run(self) -> None: |
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self._pcapfile = open(self._pcap, 'rb') |
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# move file pointer to first packet header |
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global_header_length = 24 |
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self._pcapfile.seek(global_header_length, 0) |
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first_ts = 0 |
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start_time = time.time() |
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while not self._stopper.is_set(): |
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try: |
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ts_sec, = unpack('i', self._pcapfile.read(4)) |
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except error: |
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break |
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ts_usec = unpack('i', self._pcapfile.read(4))[0] / 1000000 |
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if first_ts is 0: |
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first_ts = ts_sec + ts_usec |
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ts = ts_sec + ts_usec |
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send_time = ts - first_ts |
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elapsed_time = time.time() - start_time |
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if send_time > (elapsed_time): |
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sleep_time = send_time - elapsed_time |
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time.sleep(sleep_time) |
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packet_length = unpack('i', self._pcapfile.read(4))[0] |
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self._pcapfile.seek(4, 1) |
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for i in range(packet_length): |
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self._buffer.put(self._pcapfile.read(1)) |
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self._pcapfile.close() |
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def _isOpen(self) -> bool: |
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return self._isopen |
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def _open(self) -> None: |
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self._isopen = True |
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self._loop = self.PcapLoop(self._pcap, self._buffer) |
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self._loop.start() |
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def _close(self) -> None: |
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self._isopen = False |
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if self._loop is not None: |
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if self._loop.is_alive(): |
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self._loop.stop() |
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self._loop.join() |
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self._loop = None |
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def _read(self, count: int, timeout=None) -> bytes: |
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result = bytearray() |
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while len(result) < count: |
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result += self._buffer.get(block=True, timeout=timeout) |
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return bytes(result) |
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def _write(self, data: bytes) -> None: |
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pass |
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