pybatmesh/naxalnet/scripts.py

# This file is part of naxalnet.
# Copyright (C) 2021 The naxalnet Authors

# 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 3 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/>.

"""
scripts.py
----------

The functions in this file is used for reading configs, args
and doing the things this program is supposed to do.
This file is named scripts.py because the original developer
of this program could not think of a better name that suits this file.
If you want to hack naxalnet, this is the right place to start.
When run from the commandline, the function main() is called.
"""

import sys
import time
from pathlib import Path
from dasbus.error import DBusError
from systemd.daemon import notify
from naxalnet import __version__
from naxalnet.default import REPORT_BUG_INFO, MESH_GLOB, TMP_NET_GLOB
from naxalnet.log import logger
from naxalnet.iwd import Adapter, Device, IWD
from naxalnet.config import args
from naxalnet.daemon import Daemon
from naxalnet.network import NetworkD

# List of wireless devices used as part of the mesh.
# Used to poweroff devices during cleanup.
# Though used as a variable, thi e name is
# capitalised to shut up pylint and co.
USED_DEVICES = []


def get_sorted_glob(directory: str, glob: str) -> list:
    """return sorted list of filenames matching glob"""
    path = Path(directory)
    glob_list = path.glob(glob)
    sorted_list = []
    for i in glob_list:
        # g is a list of PosixPath objects.
        # So we add their absolute path as str.
        sorted_list.append(str(i))
    # sorted_list is not sorted, so we sort them here
    sorted_list.sort()
    return sorted_list


def any_interface_is_routable():
    """returns true if any of the interfaces is routable"""
    networkd = NetworkD(runtime_dir=args.networkd_runtime_dir)

    # First, add the temporary configs to networkd.
    for i in get_sorted_glob(args.networkd_config_dir, TMP_NET_GLOB):
        logger.debug("Adding temporary config %s", i)
        networkd.add_config(i)
    # Then, wait for some time to setup the network
    time.sleep(10)
    routable = networkd.is_routable()
    networkd.remove_all_configs()

    return routable


def setup_mesh(gateway_mode: str = "off"):
    """
    configure networkd to setup the mesh

    gateway_mode can be client, server, or off
    """
    try:
        notify("STATUS=Configuring the network...")
        logger.info("Copying network config files")

        networkd = NetworkD(runtime_dir=args.networkd_runtime_dir)
        networkd.set_vars(
            batdev=args.batman_device,
            bridgedev=args.bridge_device,
            gateway_mode=gateway_mode,
        )

        # Fix for issue #19
        networkd.disable_config("80-wifi-adhoc.network")

        for i in get_sorted_glob(args.networkd_config_dir, MESH_GLOB):
            logger.debug("Adding network config %s", i)
            networkd.add_config(i)
    except PermissionError:
        logger.exception("A PermissionError occured while copying files")
        logger.error(REPORT_BUG_INFO)
        sys.exit(3)
    except:
        logger.exception("An unknown error occured while copying files")
        logger.error(REPORT_BUG_INFO)
        sys.exit(3)


def setup_devices():
    """
    Setup wifi interfaces using iwd
    This function should be called every time an interface
    is connected or removed.
    """
    try:
        notify("STATUS=Setting up mesh...")
        iwd = IWD()
        devices = iwd.get_devices()
        adhoc_devices = []
        ap_devices = []

        global USED_DEVICES
        USED_DEVICES = []

        # Find devices supporting ad-hoc and ap
        for i in devices:
            # For each device, check if its adapter supports
            # ad-hoc or ap. Many adapters will support both,
            # so we will prioritise ad-hoc over ap.
            device = Device(i)
            logger.debug("Found device %s", device.name)
            adapter = Adapter(device.adapter)
            if adapter.supports_mode("ad-hoc"):
                logger.debug("The device %s can be used for ad-hoc", device.name)
                adhoc_devices.append(i)
            if adapter.supports_mode("ap"):
                logger.debug("The device %s can be used for ap", device.name)
                ap_devices.append(i)

        if len(adhoc_devices) != 0:
            # Start ad-hoc on first device supporting ad-hoc
            adhoc_device = Device(adhoc_devices.pop())
            # The same device is likely to have ap support too.
            # But we can't start ad-hoc and ap on the same interface.
            # So we will remove adhoc_device from ap_devices if it exists there
            if adhoc_device.name in ap_devices:
                ap_devices.remove(adhoc_device.name)

            # Turn on adapter if it is off
            # See issue #9
            adhoc_adapter = Adapter(adhoc_device.adapter)
            if not adhoc_adapter.is_powered_on():
                logger.debug("Adapter %s is off. Turning on", adhoc_adapter.name)
                adhoc_adapter.power_on()

            logger.info("Starting mesh on %s", adhoc_device.name)
            adhoc_device.start_adhoc_open(args.adhoc_name)
            USED_DEVICES.append(adhoc_device.name)

            # Start Access point if ap_device is not empty,
            # ie, we have more devices
            if len(ap_devices) != 0:
                ap_device = Device(ap_devices.pop())
                logger.info("Starting WiFi Access Point on %s", ap_device.name)
                logger.info("Use naxalnet --print-wifi to get password")
                # Turn on adapter if it is off
                # See issue #9
                ap_adapter = Adapter(ap_device.adapter)
                if not ap_adapter.is_powered_on():
                    logger.debug("Adapter %s is off. Turning on", ap_adapter.name)
                    ap_adapter.power_on()
                ap_device.start_ap(args.ap_ssid, args.ap_passwd)
                USED_DEVICES.append(ap_device.name)
            else:
                logger.warning("Not setting up WiFi AP.")
        else:
            logger.warning(
                "No device found to setup mesh. Make sure a WiFi adapter is connected"
            )

    except DBusError:
        logger.exception("Error while communicating with iwd")
        logger.error(REPORT_BUG_INFO)
        sys.exit(4)
    except:
        logger.exception("An unknown error occured while setting up the mesh")
        logger.error(REPORT_BUG_INFO)
        sys.exit(4)


def cleanup():
    """
    Remove all network config, poweroff used wireless devices and
    exit with 0.
    """
    networkd = NetworkD(runtime_dir=args.networkd_runtime_dir)
    logger.info("Exiting gracefully")
    networkd.remove_all_configs()
    for i in USED_DEVICES:
        device = Device(i)
        device.set_mode("station")
        device.power_off()
    networkd.delete_interface(args.batman_device)
    networkd.delete_interface(args.bridge_device)


def print_wifi():
    """
    Prints the name and password of the adhoc, and ap
    from the arguments
    """
    print("Mesh name:", args.adhoc_name)
    print("SSID:", args.ap_ssid)
    print("Password:", args.ap_passwd)


def print_version():
    """Just does what the name suggests"""
    print(__version__)


def main():
    """
    This is where the magic happens!
    This function is run every time you
    execute naxalnet from the commandline
    """

    if args.print_wifi:
        print_wifi()
        sys.exit(0)
    elif args.version:
        print_version()
        sys.exit(0)

    # Notify systemd that naxalnet is ready.
    # see man:sd_notify(3)
    notify("READY=1")

    if args.gateway_mode == "auto":
        logger.info("Checking for internet connection")
        notify("STATUS=Checking for internet")
        # If any interface is routable, set gateway mode to server
        if any_interface_is_routable():
            gateway_mode = "server"
        else:
            gateway_mode = "client"
        logger.info("gateway_mode set to %s", gateway_mode)
    elif args.gateway_mode in ["server", "client", "off"]:
        gateway_mode = args.gateway_mode
    else:
        logger.error("gateway-mode has an illegal value")
        sys.exit(5)

    try:
        setup_devices()
        setup_mesh()

        # Start the daemon so that setup_devices() is called every
        # time a device is connected or removed.
        daemon = Daemon()
        daemon.add_callback(setup_devices)

        notify("STATUS=Waiting for changes")
        daemon.start()
    # systemd uses SIGINT to kill this program
    except KeyboardInterrupt:
        cleanup()