sigrok-iso7816-stream sets GSMTAP_FLAG_BAD_FCS (0x01) in the GSMTAP header `res` byte on desynced TPDUs (mis-framed exchanges kept for forensics). Propagate that flag through the whole pipeline so such packets are explicitly surfaced instead of decoding as garbage: - gsmtap.py: GSMTAP_FLAG_BAD_FCS const; GsmtapReceiver.read_packet() now returns (sub_type, data, flags) from the res byte. - server/capture.py: GsmtapListener forwards the flags to the DB. - pcap.py: _parse_gsmtap_hdr/_scan_gsmtap/extract_gsmtap and parse_pcap/parse_pcapng now yield a (ts, type, payload, flags) tuple, so the flag survives a PCAP/PCAPNG round-trip. - server/server.py: PCAP import stores the flags. - server/decode.py: gsmtap_flag_names() maps bit 0x01 to 'bad FCS (desynced)'; merged into decoded errors for tpdu/atr/pps and rst/vcc, so the frontend ⚠ badge + Errors row flag the entry. User-visible: desynced TPDUs show a ⚠ "bad FCS (desynced)" marker in the trace and detail views. Tests: +4 (decode BAD_FCS markers, PCAP flag round-trip); existing tests updated for the new tuple arities. Version 1.22.0, SW cache simtrace-analyser-v32.
147 lines
4.1 KiB
Python
147 lines
4.1 KiB
Python
"""Capture backends: GSMTAP listener and direct SIMtrace2 sniffer."""
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import time
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import threading
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from ..gsmtap import (GsmtapReceiver, GSMTAP_SIM_ATR,
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GSMTAP_SIM_RST_EVENT, GSMTAP_SIM_VCC_EVENT)
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def gsmtap_msg_type(sub_type):
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"""Map a GSMTAP-SIM sub_type to a stored message type.
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Custom sigrok-iso7816-stream line events (0x10/0x11) become 'rst'/'vcc';
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everything except ATR defaults to 'tpdu'.
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"""
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return {
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GSMTAP_SIM_ATR: 'atr',
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GSMTAP_SIM_RST_EVENT: 'rst',
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GSMTAP_SIM_VCC_EVENT: 'vcc',
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}.get(sub_type, 'tpdu')
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class GsmtapListener:
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def __init__(self, bind_port=4729):
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self._receiver = GsmtapReceiver(bind_port=bind_port)
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self._running = False
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def start(self):
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self._running = True
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def stop(self):
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self._running = False
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self._receiver.close()
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def iter_messages(self):
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while self._running:
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sub_type, data, flags = self._receiver.read_packet()
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if sub_type is None:
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continue
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yield gsmtap_msg_type(sub_type), data, flags
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class DirectSniffer:
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def __init__(self):
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from ..device import SniffSession
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self._session = SniffSession(
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reconnect=True,
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reconnect_delay_min=1.0,
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reconnect_delay_max=10.0,
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inactivity_timeout=0.0,
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)
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self._running = False
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@property
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def connected(self):
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"""True while the USB sniffer device is open."""
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return self._session.connected
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def start(self):
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self._running = True
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def stop(self):
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self._running = False
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self._session.close()
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def iter_messages(self):
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from ..device import DeviceDisconnected
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try:
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for msg in self._session.iter_messages():
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if not self._running:
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break
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yield msg.type, msg.data, msg.flags
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except DeviceDisconnected:
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return
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class CaptureManager:
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def __init__(self, backend, db):
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self._backend = backend
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self._db = db
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self._session_id = None
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self._thread = None
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self._start_time = 0.0
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self._latest_msg_id = 0
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@property
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def active(self):
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return self._session_id is not None
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@property
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def session_id(self):
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return self._session_id
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@property
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def start_time(self):
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return self._start_time
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@property
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def latest_msg_id(self):
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return self._latest_msg_id
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@property
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def device_connected(self):
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"""True while the capture device is connected, or None when the
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backend has no device concept (gsmtap)."""
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if isinstance(self._backend, DirectSniffer):
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return self._backend.connected
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return None
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def start_session(self):
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if self._session_id is not None:
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self.stop_session()
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mode = 'gsmtap' if isinstance(self._backend, GsmtapListener) else 'direct'
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self._session_id = self._db.create_session(mode)
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self._start_time = time.monotonic()
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self._latest_msg_id = 0
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self._backend.start()
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self._thread = threading.Thread(target=self._capture_loop, daemon=True)
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self._thread.start()
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return self._session_id
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def stop_session(self):
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if self._session_id is None:
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return None
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self._backend.stop()
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if self._thread is not None:
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self._thread.join(timeout=2.0)
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sid = self._session_id
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self._session_id = None
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self._start_time = 0.0
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if self._db.count_messages(sid) == 0:
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self._db.delete_session(sid)
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return None
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self._db.close_session(sid)
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return sid
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def _capture_loop(self):
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for msg_type, data, flags in self._backend.iter_messages():
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if self._session_id is None:
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break
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elapsed = round(time.monotonic() - self._start_time, 3)
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mid = self._db.insert_message(self._session_id, elapsed, msg_type, data, flags)
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self._latest_msg_id = mid
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