import subprocess from pathlib import Path from iottb.definitions import * from iottb.models.capture_metadata_model import CaptureMetadata from iottb.models.device_metadata_model import DeviceMetadata, dir_contains_device_metadata from iottb.utils.capture_utils import get_capture_src_folder, make_capture_src_folder def setup_capture_parser(subparsers): parser = subparsers.add_parser('sniff', help='Sniff packets with tcpdump') # metadata args parser.add_argument("-a", "--ip-address", help="IP address of the device to sniff", dest="device_ip") # tcpdump args parser.add_argument("device-root", help="Root folder for device to sniff", dest="device_folder", type=Path, required=True, default=Path.cwd()) parser.add_argument("-s", "--safe", help="Ensure correct device root folder before sniffing", action="store_true") parser.add_argument("--app", help="Application name to sniff", dest="app_name", default=None) parser_sniff_tcpdump = parser.add_argument_group('tcpdump arguments') parser_sniff_tcpdump.add_argument("-i", "--interface", help="Interface to capture on.", dest="capture_interface", required=True) parser_sniff_tcpdump.add_argument("-I", "--monitor-mode", help="Put interface into monitor mode", action="store_true") parser_sniff_tcpdump.add_argument("-n", help="Deactivate name resolution. True by default.", action="store_true", dest="no_name_resolution") parser_sniff_tcpdump.add_argument("-#", "--number", help="Print packet number at beginning of line. True by default.", action="store_true") parser_sniff_tcpdump.add_argument("-e", help="Print link layer headers. True by default.", action="store_true", dest="print_link_layer") parser_sniff_tcpdump.add_argument("-t", action="count", default=0, help="Please see tcpdump manual for details. Unused by default.") cap_size_group = parser.add_mutually_exclusive_group(required=False) cap_size_group.add_argument("-c", "--count", type=int, help="Number of packets to capture.", default=1000) cap_size_group.add_argument("--mins", type=int, help="Time in minutes to capture.", default=1) parser.set_defaults(func=handle_capture) def cwd_is_device_root_dir() -> bool: device_metadata_file = Path.cwd() / DEVICE_METADATA_FILE return device_metadata_file.is_file() def start_guided_device_root_dir_setup(): assert False, "Not implemented" def handle_metadata(): assert not cwd_is_device_root_dir() print(f"Unable to find {DEVICE_METADATA_FILE} in current working directory") print("You need to setup a device root directory before using this command") response = input("Would you like to be guided through the setup? [y/n]") if response.lower() == "y": start_guided_device_root_dir_setup() else: print("'iottb init-device-root --help' for more information.") exit(ReturnCodes.ABORTED) # device_id = handle_capture_metadata() return ReturnCodes.SUCCESS def get_device_metadata_from_file(device_metadata_filename: Path) -> str: assert device_metadata_filename.is_file(), f"Device metadata file '{device_metadata_filename} does not exist" device_metadata = DeviceMetadata.load_from_json(device_metadata_filename) return device_metadata def run_tcpdump(cmd): # TODO: Maybe specify files for stout and stderr try: p = subprocess.run(cmd, capture_output=True, text=True, check=True) if p.returncode != 0: print(p.stderr) else: print(p.stdout) except KeyboardInterrupt: pass def handle_capture(args): assert args.device_root is not None, f"Device root directory is required" assert dir_contains_device_metadata(args.device_root) # get device metadata if args.safe and not dir_contains_device_metadata(args.device_root): print(f"Supplied folder contains no device metadata. " f"Please setup a device root directory before using this command") exit(ReturnCodes.ABORTED) elif dir_contains_device_metadata(args.device_root): device_metadata_filename = args.device_root / DEVICE_METADATA_FILE device_data = DeviceMetadata.load_from_json(device_metadata_filename) else: name = input("Please enter a device name: ") args.device_root.mkdir(parents=True, exist_ok=True) device_data = DeviceMetadata(name, args.device_root) # start constructing environment for capture capture_dir = get_capture_src_folder(args.device_root) make_capture_src_folder(capture_dir) capture_metadata = CaptureMetadata(device_data, capture_dir) capture_metadata.set_interface(args.capture_interface) cmd = ['sudo', 'tcpdump', '-i', args.capture_interface] cmd = build_tcpdump_args(args, cmd, capture_metadata) capture_metadata.set_tcpdump_command(cmd) print('Executing: ' + ' '.join(cmd)) # run capture try: start_time = datetime.now().strftime('%H:%M:%S') run_tcpdump(cmd) stop_time = datetime.now().strftime('%H:%M:%S') capture_metadata.set_start_time(start_time) capture_metadata.set_stop_time(stop_time) except KeyboardInterrupt: print("Received keyboard interrupt.") exit(ReturnCodes.ABORTED) except subprocess.CalledProcessError as e: print(f"Failed to capture packet: {e}") exit(ReturnCodes.FAILURE) except Exception as e: print(f"Failed to capture packet: {e}") exit(ReturnCodes.FAILURE) return ReturnCodes.SUCCESS def build_tcpdump_args(args, cmd, capture_metadata: CaptureMetadata): if args.monitor_mode: cmd.append('-I') if args.no_name_resolution: cmd.append('-n') if args.number: cmd.append('-#') if args.print_link_layer: cmd.append('-e') if args.count: cmd.append('-c') cmd.append(str(args.count)) elif args.mins: assert False, "Unimplemented option" if args.app_name is not None: capture_metadata.set_app_name(args.app_name) capture_metadata.build_capture_file_name() cmd.append('-w') cmd.append(capture_metadata.get_capfile_name()) if args.safe: cmd.append(f'host {args.device_ip}') # if not specified, filter 'any' implied by tcpdump capture_metadata.set_device_ip_address(args.device_ip) return cmd # def capture_file_cmd(args, cmd, capture_dir, capture_metadata: CaptureMetadata): # capture_file_prefix = capture_metadata.get_device_metadata().get_device_short_name() # if args.app_name is not None: # capture_file_prefix = args.app_name # capture_metadata.set_app(args.app_name) # capfile_name = capture_file_prefix + "_" + str(capture_metadata.get_capture_id()) + ".pcap" # capture_metadata.set_capture_file(capfile_name) # capfile_abs_path = capture_dir / capfile_name # capture_metadata.set_capture_file(capfile_name) # cmd.append('-w') # cmd.append(str(capfile_abs_path))