catarrh
73b0277ef7
Python-based SIMtrace2 sniffer — drop-in replacement for simtrace2-sniff. Single dependency (pyusb), auto-reconnect, GSMTAP/PCAP output, library API. Modules: protocol.py — SIMtrace2 USB sniffing protocol parser device.py — USB discovery + SniffSession with exponential backoff reconnect gsmtap.py — GSMTAP UDP sender for Wireshark pcap.py — PCAP file writer (LINKTYPE_GSMTAP) dump.py — hex dump formatters + file output __main__.py — CLI entry point Startup script sniff-start.sh handles udev permission checks and shows install instructions. udev rule uses TAG+=uaccess (systemd-logind ACL).
62 lines
1.7 KiB
Python
62 lines
1.7 KiB
Python
"""GSMTAP UDP sender for Wireshark integration.
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GSMTAP header format (big-endian, 16 bytes). Based on libosmocore's gsmtap.h.
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"""
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import struct
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import socket
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GSMTAP_VERSION = 0x02
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GSMTAP_HDR_LEN = 4 # in 32-bit words (16 bytes)
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GSMTAP_TYPE_SIM = 0x07
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GSMTAP_SIM_ATR = 0x01
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GSMTAP_SIM_APDU = 0x02
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GSMTAP_UDP_PORT = 4729
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_GSMTAP_HDR_FMT = '!BBBBHBBIBBBB' # 16 bytes, big-endian
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_GSMTAP_HDR_SIZE = struct.calcsize(_GSMTAP_HDR_FMT)
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def build_gsmtap_packet(sub_type, data, slot_nr=0):
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"""Build a GSMTAP packet as bytes.
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Returns *gsmtap_hdr* + *data* as a single bytes object.
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"""
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hdr = struct.pack(
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_GSMTAP_HDR_FMT,
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GSMTAP_VERSION, # version
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GSMTAP_HDR_LEN, # hdr_len (in 32-bit words)
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GSMTAP_TYPE_SIM, # type
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0, # timeslot
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0, # arfcn
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0, # noise_db
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0, # signal_db
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0, # frame_number
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sub_type, # sub_type
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0, # antenna_nr
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slot_nr, # sub_slot
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0, # res
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)
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return hdr + data
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class GsmtapSender:
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"""Send ATR/APDU data as GSMTAP UDP packets."""
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def __init__(self, host='127.0.0.1', port=GSMTAP_UDP_PORT):
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self._addr = (host, port)
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self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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def send_atr(self, data, slot_nr=0):
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packet = build_gsmtap_packet(GSMTAP_SIM_ATR, data, slot_nr)
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self._sock.sendto(packet, self._addr)
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def send_apdu(self, data, slot_nr=0):
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packet = build_gsmtap_packet(GSMTAP_SIM_APDU, data, slot_nr)
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self._sock.sendto(packet, self._addr)
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def close(self):
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self._sock.close()
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