Files
simtrace-analyser/simtrace_analyser/capture.py
T
catarrh 903ead9791 GSMTAP: --gsmtap-bind to listen beyond loopback (containers)
A container's 127.0.0.1 is its own loopback, so a GSMTAP feed sent to the
container's bridge address never reached the listener: it was hard-bound to
127.0.0.1.

- `simtrace-analyser-server --gsmtap-bind ADDR` (default 127.0.0.1) is passed
  through GsmtapListener to GsmtapReceiver (whose bind_ip already existed),
  including the receiver re-created by a start() after close.  The startup
  banner prints the effective bind address next to the port.
- READMEs (EN/RU) document the option, naming the container case.
- tests: the listener forwards the address on construction and on start(),
  binds 0.0.0.0, and keeps the loopback default.

Verified end-to-end: with --gsmtap-bind 0.0.0.0 the socket listens on
0.0.0.0:14732 and an ATR + APDU sent to 127.0.0.1:14732 landed in the capture
session (2 messages); without the flag it listens on 127.0.0.1.
557 Python + 80 Node tests.
2026-10-26 14:45:58 +03:00

249 lines
8.2 KiB
Python

"""Capture backends: GSMTAP listener and direct SIMtrace2 sniffer."""
import struct
import sys
import threading
import time
import traceback
from simtrace2_pysniff.gsmtap import (GsmtapReceiver, GSMTAP_SIM_ATR,
GSMTAP_SIM_PPS_REQ, GSMTAP_SIM_PPS_RSP,
GSMTAP_SIM_RST_EVENT, GSMTAP_SIM_VCC_EVENT)
from .decode import looks_like_apdu
def _ts():
"""Local-time stamp for server-side capture log lines."""
return time.strftime('%Y-%m-%d %H:%M:%S')
def _log(msg):
print(f'[{_ts()}] {msg}', file=sys.stderr)
def gsmtap_msg_type(sub_type):
"""Map a GSMTAP-SIM sub_type to a stored message type.
PPS request/response (0x02/0x03, standard GSMTAP) become 'pps'; custom
sigrok-iso7816-stream line events (0x10/0x11) become 'rst'/'vcc';
everything else defaults to 'tpdu'.
"""
return {
GSMTAP_SIM_ATR: 'atr',
GSMTAP_SIM_PPS_REQ: 'pps',
GSMTAP_SIM_PPS_RSP: 'pps',
GSMTAP_SIM_RST_EVENT: 'rst',
GSMTAP_SIM_VCC_EVENT: 'vcc',
}.get(sub_type, 'tpdu')
class GsmtapListener:
def __init__(self, bind_port=4729, bind_ip='127.0.0.1'):
self._bind_port = bind_port
self._bind_ip = bind_ip
self._receiver = GsmtapReceiver(bind_ip=bind_ip, bind_port=bind_port)
self._running = False
self._dropped = 0
def start(self):
if getattr(self._receiver, '_closed', False):
self._receiver = GsmtapReceiver(bind_ip=self._bind_ip,
bind_port=self._bind_port)
self._running = True
self._dropped = 0
def stop(self):
self._running = False
self._receiver.close()
@property
def dropped(self):
return self._dropped
def iter_messages(self):
while self._running:
try:
sub_type, data, flags = self._receiver.read_packet()
except (ValueError, struct.error) as e:
# A malformed or non-SIM GSMTAP datagram (a different
# GSMTAP packet type, a truncated frame, …) must not kill
# the whole capture — drop it and keep listening.
self._dropped += 1
if self._dropped <= 1 or self._dropped % 100 == 0:
_log(f'GSMTAP: dropped packet ({self._dropped}): {e}')
continue
if sub_type is None:
continue
yield gsmtap_msg_type(sub_type), data, flags
class DirectSniffer:
def __init__(self):
from simtrace2_pysniff.device import SniffSession
self._session = SniffSession(
reconnect=True,
reconnect_delay_min=1.0,
reconnect_delay_max=10.0,
inactivity_timeout=0.0,
)
self._running = False
@property
def connected(self):
"""True while the USB sniffer device is open."""
return self._session.connected
def start(self):
self._running = True
def stop(self):
self._running = False
self._session.close()
def iter_messages(self):
from simtrace2_pysniff.device import DeviceDisconnected
try:
for msg in self._session.iter_messages():
if not self._running:
break
yield msg.type, msg.data, msg.flags
except DeviceDisconnected:
return
class CaptureManager:
def __init__(self, backend, db, log_interval=60.0):
self._backend = backend
self._db = db
self._session_id = None
self._thread = None
self._log_thread = None
self._stop_event = threading.Event()
self._start_time = 0.0
self._latest_msg_id = 0
self._msg_count = 0
self._byte_count = 0
self._skipped = 0
self._log_interval = log_interval
@property
def active(self):
return self._session_id is not None
@property
def session_id(self):
return self._session_id
@property
def start_time(self):
return self._start_time
@property
def latest_msg_id(self):
return self._latest_msg_id
@property
def skipped(self):
"""Packets dropped because they were not APDU-shaped."""
return self._skipped
@property
def device_connected(self):
"""True while the capture device is connected, or None when the
backend has no device concept (gsmtap)."""
if isinstance(self._backend, DirectSniffer):
return self._backend.connected
return None
def start_session(self):
if self._session_id is not None:
self.stop_session()
mode = 'gsmtap' if isinstance(self._backend, GsmtapListener) else 'direct'
self._session_id = self._db.create_session(mode)
self._start_time = time.monotonic()
self._latest_msg_id = 0
self._msg_count = 0
self._byte_count = 0
self._skipped = 0
self._backend.start()
self._thread = threading.Thread(target=self._capture_loop, daemon=True)
self._thread.start()
self._stop_event.clear()
_log(f'Capture started (mode={mode}, session={self._session_id})')
self._log_thread = threading.Thread(target=self._log_loop, daemon=True)
self._log_thread.start()
return self._session_id
def stop_session(self):
if self._session_id is None:
return None
self._stop_event.set()
self._backend.stop()
if self._thread is not None:
self._thread.join(timeout=2.0)
if self._log_thread is not None:
self._log_thread.join(timeout=2.0)
sid = self._session_id
self._session_id = None
self._start_time = 0.0
empty = self._db.count_messages(sid) == 0
if empty:
self._db.delete_session(sid)
_log(f'Capture stopped: empty session discarded (session={sid})')
return None
self._db.close_session(sid)
_log(f'Capture stopped: session={sid} messages={self._msg_count} '
f'bytes={self._byte_count} skipped={self._skipped}')
return sid
def _capture_loop(self):
try:
for msg_type, data, flags in self._backend.iter_messages():
if self._session_id is None:
break
if msg_type == 'tpdu' and not looks_like_apdu(data):
# Not APDU-shaped at all: a mis-sampled or character-level
# GSMTAP stream would only pollute the decode.
self._skipped += 1
if self._skipped <= 1 or self._skipped % 100 == 0:
_log(f'Capture: skipped packet {self._skipped} that is '
f'not APDU-shaped — check the sniffer stream')
continue
try:
elapsed = round(time.monotonic() - self._start_time, 3)
mid = self._db.insert_message(
self._session_id, elapsed, msg_type, data, flags)
self._msg_count += 1
self._byte_count += len(data)
self._latest_msg_id = mid
except Exception as e:
_log(f'Capture: insert error, dropping msg: {e}')
continue
except Exception:
# The capture thread died unexpectedly (not a user stop).
sid = self._session_id
_log(f'ERROR: capture thread stopped on error (session={sid}):')
traceback.print_exc()
self._stop_event.set()
if sid is not None:
try:
self._db.close_session(sid)
except Exception:
pass
self._session_id = None
return
def _log_loop(self):
while not self._stop_event.wait(self._log_interval):
if self._session_id is None:
break
dropped = getattr(self._backend, 'dropped', 0)
_log(f'Capture alive: session={self._session_id} '
f'messages={self._msg_count} bytes={self._byte_count} '
f'dropped={dropped} skipped={self._skipped}')