1 files changed, 286 insertions, 0 deletions
diff --git a/src/target/trx_toolkit/trx_sniff.py b/src/target/trx_toolkit/trx_sniff.py
new file mode 100755
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+++ b/src/target/trx_toolkit/trx_sniff.py
@@ -0,0 +1,286 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+# TRX Toolkit
+# Scapy-based TRX interface sniffer
+#
+# (C) 2018 by Vadim Yanitskiy <axilirator@gmail.com>
+#
+# All Rights Reserved
+#
+# 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, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+from copyright import print_copyright
+CR_HOLDERS = [("2018", "Vadim Yanitskiy <axilirator@gmail.com>")]
+
+import signal
+import getopt
+import sys
+
+import scapy.all
+
+from data_dump import DATADumpFile
+from data_msg import *
+
+class Application:
+	# Application variables
+	sniff_interface = "lo"
+	sniff_base_port = 5700
+	print_bursts = False
+	output_file = None
+
+	# Counters
+	cnt_burst_dropped_num = 0
+	cnt_burst_break = None
+	cnt_burst_num = 0
+
+	cnt_frame_break = None
+	cnt_frame_last = None
+	cnt_frame_num = 0
+
+	# Burst direction fliter
+	bf_dir_l12trx = None
+
+	# Timeslot number filter
+	bf_tn_val = None
+
+	# Frame number fliter
+	bf_fn_lt = None
+	bf_fn_gt = None
+
+	# Internal variables
+	lo_trigger = False
+
+	def __init__(self):
+		print_copyright(CR_HOLDERS)
+		self.parse_argv()
+
+		# Open requested capture file
+		if self.output_file is not None:
+			self.ddf = DATADumpFile(self.output_file)
+
+	def run(self):
+		# Compose a packet filter
+		pkt_filter = "udp and (port %d or port %d)" \
+			% (self.sniff_base_port + 2, self.sniff_base_port + 102)
+
+		print("[i] Listening on interface '%s'..." % self.sniff_interface)
+
+		# Start sniffing...
+		scapy.all.sniff(iface = self.sniff_interface, store = 1,
+			filter = pkt_filter, prn = self.pkt_handler)
+
+		# Scapy registers its own signal handler
+		self.shutdown()
+
+	def pkt_handler(self, ether):
+		# Prevent loopback packet duplication
+		if self.sniff_interface == "lo":
+			self.lo_trigger = not self.lo_trigger
+			if not self.lo_trigger:
+				return
+
+		# Extract a TRX payload
+		ip = ether.payload
+		udp = ip.payload
+		trx = udp.payload
+
+		# Convert to bytearray
+		msg_raw = bytearray(str(trx))
+
+		# Determine a burst direction (L1 <-> TRX)
+		l12trx = udp.sport > udp.dport
+
+		# Create an empty DATA message
+		msg = DATAMSG_L12TRX() if l12trx else DATAMSG_TRX2L1()
+
+		# Attempt to parse the payload as a DATA message
+		try:
+			msg.parse_msg(msg_raw)
+		except:
+			print("[!] Failed to parse message, dropping...")
+			self.cnt_burst_dropped_num += 1
+			return
+
+		# Poke burst pass filter
+		rc = self.burst_pass_filter(l12trx, msg.fn, msg.tn)
+		if rc is False:
+			self.cnt_burst_dropped_num += 1
+			return
+
+		# Debug print
+		print("[i] %s burst: %s" \
+			% ("L1 -> TRX" if l12trx else "TRX -> L1", msg.desc_hdr()))
+
+		# Poke message handler
+		self.msg_handle(msg)
+
+		# Poke burst counter
+		rc = self.burst_count(msg.fn, msg.tn)
+		if rc is True:
+			self.shutdown()
+
+	def burst_pass_filter(self, l12trx, fn, tn):
+		# Direction filter
+		if self.bf_dir_l12trx is not None:
+			if l12trx != self.bf_dir_l12trx:
+				return False
+
+		# Timeslot filter
+		if self.bf_tn_val is not None:
+			if tn != self.bf_tn_val:
+				return False
+
+		# Frame number filter
+		if self.bf_fn_lt is not None:
+			if fn > self.bf_fn_lt:
+				return False
+		if self.bf_fn_gt is not None:
+			if fn < self.bf_fn_gt:
+				return False
+
+		# Burst passed ;)
+		return True
+
+	def msg_handle(self, msg):
+		if self.print_bursts:
+			print(msg.burst)
+
+		# Append a new message to the capture
+		if self.output_file is not None:
+			self.ddf.append_msg(msg)
+
+	def burst_count(self, fn, tn):
+		# Update frame counter
+		if self.cnt_frame_last is None:
+			self.cnt_frame_last = fn
+			self.cnt_frame_num += 1
+		else:
+			if fn != self.cnt_frame_last:
+				self.cnt_frame_num += 1
+
+		# Update burst counter
+		self.cnt_burst_num += 1
+
+		# Stop sniffing after N bursts
+		if self.cnt_burst_break is not None:
+			if self.cnt_burst_num == self.cnt_burst_break:
+				print("[i] Collected required amount of bursts")
+				return True
+
+		# Stop sniffing after N frames
+		if self.cnt_frame_break is not None:
+			if self.cnt_frame_num == self.cnt_frame_break:
+				print("[i] Collected required amount of frames")
+				return True
+
+		return False
+
+	def shutdown(self):
+		print("[i] Shutting down...")
+
+		# Print statistics
+		print("[i] %u bursts handled, %u dropped" \
+			% (self.cnt_burst_num, self.cnt_burst_dropped_num))
+
+		# Exit
+		sys.exit(0)
+
+	def print_help(self, msg = None):
+		s  = " Usage: " + sys.argv[0] + " [options]\n\n" \
+			 " Some help...\n" \
+			 "  -h --help              this text\n\n"
+
+		s += " Sniffing options\n" \
+			 "  -i --sniff-interface   Set network interface (default '%s')\n"  \
+			 "  -p --sniff-base-port   Set base port number (default %d)\n\n"
+
+		s += " Processing (no processing by default)\n" \
+			 "  -o --output-file       Write bursts to file\n"          \
+			 "  -v --print-bits        Print burst bits to stdout\n\n"  \
+
+		s += " Count limitations (disabled by default)\n" \
+			 "  --frame-count   NUM    Stop after sniffing NUM frames\n"  \
+			 "  --burst-count   NUM    Stop after sniffing NUM bursts\n\n"
+
+		s += " Filtering (disabled by default)\n" \
+			 "  --direction     DIR    Burst direction: L12TRX or TRX2L1\n"  \
+			 "  --timeslot      NUM    TDMA timeslot number [0..7]\n"        \
+			 "  --frame-num-lt  NUM    TDMA frame number lower than NUM\n"   \
+			 "  --burst-num-gt  NUM    TDMA frame number greater than NUM\n"
+
+		print(s % (self.sniff_interface, self.sniff_base_port))
+
+		if msg is not None:
+			print(msg)
+
+	def parse_argv(self):
+		try:
+			opts, args = getopt.getopt(sys.argv[1:],
+				"i:p:o:v:h", ["help", "sniff-interface=", "sniff-base-port=",
+					"frame-count=", "burst-count=", "direction=",
+					"timeslot=", "frame-num-lt=", "frame-num-gt=",
+					"output-file=", "print-bits"])
+		except getopt.GetoptError as err:
+			self.print_help("[!] " + str(err))
+			sys.exit(2)
+
+		for o, v in opts:
+			if o in ("-h", "--help"):
+				self.print_help()
+				sys.exit(2)
+
+			elif o in ("-i", "--sniff-interface"):
+				self.sniff_interface = v
+			elif o in ("-p", "--sniff-base-port"):
+				self.sniff_base_port = int(v)
+
+			elif o in ("-o", "--output-file"):
+				self.output_file = v
+			elif o in ("-v", "--print-bits"):
+				self.print_bursts = True
+
+			# Break counters
+			elif o == "--frame-count":
+				self.cnt_frame_break = int(v)
+			elif o == "--burst-count":
+				self.cnt_burst_break = int(v)
+
+			# Direction filter
+			elif o == "--direction":
+				if v == "L12TRX":
+					self.bf_dir_l12trx = True
+				elif v == "TRX2L1":
+					self.bf_dir_l12trx = False
+				else:
+					self.print_help("[!] Wrong direction argument")
+					sys.exit(2)
+
+			# Timeslot pass filter
+			elif o == "--timeslot":
+				self.bf_tn_val = int(v)
+				if self.bf_tn_val < 0 or self.bf_tn_val > 7:
+					self.print_help("[!] Wrong timeslot value")
+					sys.exit(2)
+
+			# Frame number pass filter
+			elif o == "--frame-num-lt":
+				self.bf_fn_lt = int(v)
+			elif o == "--frame-num-gt":
+				self.bf_fn_gt = int(v)
+
+if __name__ == '__main__':
+	app = Application()
+	app.run()