Files
pysim/pySim/gsmtap.py
Harald Welte a3962b2076 Migrate over to using pyosmocom
We're creating a 'pyosmocom' pypi module which contains a number of core
Osmocom libraries / interfaces that are not specific to SIM card stuff
contained here.

The main modules moved in this initial step are pySim.tlv, pySim.utils
and pySim.construct. utils is split, not all of the contents is
unrelated to SIM Cards.  The other two are moved completely.

Change-Id: I4b63e45bcb0c9ba2424dacf85e0222aee735f411
2024-09-03 21:57:47 +02:00

215 lines
9.5 KiB
Python

# -*- coding: utf-8 -*-
""" Osmocom GSMTAP python implementation.
GSMTAP is a packet format used for conveying a number of different
telecom-related protocol traces over UDP.
"""
#
# Copyright (C) 2022 Harald Welte <laforge@gnumonks.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import socket
from construct import Optional as COptional
from construct import Int8ub, Int8sb, Int32ub, BitStruct, Enum, GreedyBytes, Struct, Switch
from construct import this, PaddedString, Flag, BitsInteger, Bytes
from osmocom.construct import *
# The root definition of GSMTAP can be found at
# https://cgit.osmocom.org/cgit/libosmocore/tree/include/osmocom/core/gsmtap.h
GSMTAP_UDP_PORT = 4729
# GSMTAP_TYPE_*
gsmtap_type_construct = Enum(Int8ub,
gsm_um = 0x01,
gsm_abis = 0x02,
gsm_um_burst = 0x03,
sim = 0x04,
tetra_i1 = 0x05,
tetra_i1_burst = 0x06,
wimax_burst = 0x07,
gprs_gb_llc = 0x08,
gprs_gb_sndcp = 0x09,
gmr1_um = 0x0a,
umts_rlc_mac = 0x0b,
umts_rrc = 0x0c,
lte_rrc = 0x0d,
lte_mac = 0x0e,
lte_mac_framed = 0x0f,
osmocore_log = 0x10,
qc_diag = 0x11,
lte_nas = 0x12,
e1_t1 = 0x13)
# TYPE_UM_BURST
gsmtap_subtype_burst_construct = Enum(Int8ub,
unknown = 0x00,
fcch = 0x01,
partial_sch = 0x02,
sch = 0x03,
cts_sch = 0x04,
compact_sch = 0x05,
normal = 0x06,
dummy = 0x07,
access = 0x08,
none = 0x09)
gsmtap_subtype_wimax_burst_construct = Enum(Int8ub,
cdma_code = 0x10,
fch = 0x11,
ffb = 0x12,
pdu = 0x13,
hack = 0x14,
phy_attributes = 0x15)
# GSMTAP_CHANNEL_*
gsmtap_subtype_um_construct = Enum(Int8ub,
unknown = 0x00,
bcch = 0x01,
ccch = 0x02,
rach = 0x03,
agch = 0x04,
pch = 0x05,
sdcch = 0x06,
sdcch4 = 0x07,
sdcch8 = 0x08,
facch_f = 0x09,
facch_h = 0x0a,
pacch = 0x0b,
cbch52 = 0x0c,
pdtch = 0x0d,
ptcch = 0x0e,
cbch51 = 0x0f,
voice_f = 0x10,
voice_h = 0x11)
# GSMTAP_SIM_*
gsmtap_subtype_sim_construct = Enum(Int8ub,
apdu = 0x00,
atr = 0x01,
pps_req = 0x02,
pps_rsp = 0x03,
tpdu_hdr = 0x04,
tpdu_cmd = 0x05,
tpdu_rsp = 0x06,
tpdu_sw = 0x07)
gsmtap_subtype_tetra_construct = Enum(Int8ub,
bsch = 0x01,
aach = 0x02,
sch_hu = 0x03,
sch_hd = 0x04,
sch_f = 0x05,
bnch = 0x06,
stch = 0x07,
tch_f = 0x08,
dmo_sch_s = 0x09,
dmo_sch_h = 0x0a,
dmo_sch_f = 0x0b,
dmo_stch = 0x0c,
dmo_tch = 0x0d)
gsmtap_subtype_gmr1_construct = Enum(Int8ub,
unknown = 0x00,
bcch = 0x01,
ccch = 0x02,
pch = 0x03,
agch = 0x04,
bach = 0x05,
rach = 0x06,
cbch = 0x07,
sdcch = 0x08,
tachh = 0x09,
gbch = 0x0a,
tch3 = 0x10,
tch6 = 0x14,
tch9 = 0x18)
gsmtap_subtype_e1t1_construct = Enum(Int8ub,
lapd = 0x01,
fr = 0x02,
raw = 0x03,
trau16 = 0x04,
trau8 = 0x05)
gsmtap_arfcn_construct = BitStruct('pcs'/Flag, 'uplink'/Flag, 'arfcn'/BitsInteger(14))
gsmtap_hdr_construct = Struct('version'/Int8ub,
'hdr_len'/Int8ub,
'type'/gsmtap_type_construct,
'timeslot'/Int8ub,
'arfcn'/gsmtap_arfcn_construct,
'signal_dbm'/Int8sb,
'snr_db'/Int8sb,
'frame_nr'/Int32ub,
'sub_type'/Switch(this.type, {
'gsm_um': gsmtap_subtype_um_construct,
'gsm_um_burst': gsmtap_subtype_burst_construct,
'sim': gsmtap_subtype_sim_construct,
'tetra_i1': gsmtap_subtype_tetra_construct,
'tetra_i1_burst': gsmtap_subtype_tetra_construct,
'wimax_burst': gsmtap_subtype_wimax_burst_construct,
'gmr1_um': gsmtap_subtype_gmr1_construct,
'e1_t1': gsmtap_subtype_e1t1_construct,
}),
'antenna_nr'/Int8ub,
'sub_slot'/Int8ub,
'res'/Int8ub,
'body'/GreedyBytes)
osmocore_log_ts_construct = Struct('sec'/Int32ub, 'usec'/Int32ub)
osmocore_log_level_construct = Enum(Int8ub, debug=1, info=3, notice=5, error=7, fatal=8)
gsmtap_osmocore_log_hdr_construct = Struct('ts'/osmocore_log_ts_construct,
'proc_name'/PaddedString(16, 'ascii'),
'pid'/Int32ub,
'level'/osmocore_log_level_construct,
Bytes(3),
'subsys'/PaddedString(16, 'ascii'),
'src_file'/Struct('name'/PaddedString(32, 'ascii'), 'line_nr'/Int32ub))
class GsmtapMessage:
"""Class whose objects represent a single GSMTAP message. Can encode and decode messages."""
def __init__(self, encoded = None):
self.encoded = encoded
self.decoded = None
def decode(self):
self.decoded = parse_construct(gsmtap_hdr_construct, self.encoded)
return self.decoded
def encode(self, decoded):
self.encoded = gsmtap_hdr_construct.build(decoded)
return self.encoded
class GsmtapSource:
def __init__(self, bind_ip:str='127.0.0.1', bind_port:int=4729):
self.bind_ip = bind_ip
self.bind_port = bind_port
self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.sock.bind((self.bind_ip, self.bind_port))
def read_packet(self) -> GsmtapMessage:
data, addr = self.sock.recvfrom(1024)
gsmtap_msg = GsmtapMessage(data)
gsmtap_msg.decode()
if gsmtap_msg.decoded['version'] != 0x02:
raise ValueError('Unknown GSMTAP version 0x%02x' % gsmtap_msg.decoded['version'])
return gsmtap_msg.decoded, addr