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88 lines
2.8 KiB
88 lines
2.8 KiB
"""Tool to convert Envoy tap trace format to PCAP. |
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Uses od and text2pcap (part of Wireshark) utilities to translate the Envoy |
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tap trace proto format to a PCAP file suitable for consuming in Wireshark |
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and other tools in the PCAP ecosystem. The TCP stream in the output PCAP is |
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synthesized based on the known IP/port/timestamps that Envoy produces in its |
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tap files; it is not a literal wire tap. |
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Usage: |
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bazel run @envoy_api_canonical//tools:tap2pcap <tap .pb/.pb_text> <pcap path> |
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Known issues: |
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- IPv6 PCAP generation has malformed TCP packets. This appears to be a text2pcap |
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issue. |
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TODO(htuch): |
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- Figure out IPv6 PCAP issue above, or file a bug once the root cause is clear. |
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""" |
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from __future__ import print_function |
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import datetime |
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import socket |
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import StringIO |
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import subprocess as sp |
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import sys |
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import time |
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from google.protobuf import text_format |
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from envoy.data.tap.v2alpha import wrapper_pb2 |
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def DumpEvent(direction, timestamp, data): |
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dump = StringIO.StringIO() |
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dump.write('%s\n' % direction) |
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# Adjust to local timezone |
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adjusted_dt = timestamp.ToDatetime() - datetime.timedelta(seconds=time.altzone) |
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dump.write('%s\n' % adjusted_dt) |
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od = sp.Popen(['od', '-Ax', '-tx1', '-v'], stdout=sp.PIPE, stdin=sp.PIPE, stderr=sp.PIPE) |
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packet_dump = od.communicate(data)[0] |
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dump.write(packet_dump) |
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return dump.getvalue() |
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def Tap2Pcap(tap_path, pcap_path): |
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wrapper = wrapper_pb2.TraceWrapper() |
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if tap_path.endswith('.pb_text'): |
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with open(tap_path, 'r') as f: |
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text_format.Merge(f.read(), wrapper) |
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else: |
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with open(tap_path, 'r') as f: |
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wrapper.ParseFromString(f.read()) |
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trace = wrapper.socket_buffered_trace |
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local_address = trace.connection.local_address.socket_address.address |
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local_port = trace.connection.local_address.socket_address.port_value |
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remote_address = trace.connection.remote_address.socket_address.address |
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remote_port = trace.connection.remote_address.socket_address.port_value |
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dumps = [] |
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for event in trace.events: |
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if event.HasField('read'): |
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dumps.append(DumpEvent('I', event.timestamp, event.read.data.as_bytes)) |
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elif event.HasField('write'): |
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dumps.append(DumpEvent('O', event.timestamp, event.write.data.as_bytes)) |
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ipv6 = False |
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try: |
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socket.inet_pton(socket.AF_INET6, local_address) |
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ipv6 = True |
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except socket.error: |
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pass |
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text2pcap_args = [ |
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'text2pcap', '-D', '-t', '%Y-%m-%d %H:%M:%S.', '-6' if ipv6 else '-4', |
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'%s,%s' % (remote_address, local_address), '-T', |
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'%d,%d' % (remote_port, local_port), '-', pcap_path |
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] |
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text2pcap = sp.Popen(text2pcap_args, stdout=sp.PIPE, stdin=sp.PIPE) |
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text2pcap.communicate('\n'.join(dumps)) |
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if __name__ == '__main__': |
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if len(sys.argv) != 3: |
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print('Usage: %s <tap .pb/.pb_text> <pcap path>' % sys.argv[0]) |
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sys.exit(1) |
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Tap2Pcap(sys.argv[1], sys.argv[2])
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