input-remapper/keymapper/permissions.py
2021-02-22 19:48:20 +01:00

112 lines
3.2 KiB
Python

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# key-mapper - GUI for device specific keyboard mappings
# Copyright (C) 2021 sezanzeb <proxima@sezanzeb.de>
#
# This file is part of key-mapper.
#
# key-mapper 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.
#
# key-mapper 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 key-mapper. If not, see <https://www.gnu.org/licenses/>.
"""To check if access to devices in /dev is possible."""
import grp
import glob
import getpass
import subprocess
import os
from keymapper.logger import logger
from keymapper.paths import USER
from keymapper.daemon import is_service_running
def check_group(group):
"""Check if the required group is active and log if not."""
try:
in_group = USER in grp.getgrnam(group).gr_mem
except KeyError:
# group doesn't exist. Ignore
return None
# check if files exist with that group in /dev. Even if plugdev
# exists, that doesn't mean that it is needed.
used_groups = [os.stat(path).st_gid for path in glob.glob('/dev/input/*')]
if grp.getgrnam(group).gr_gid not in used_groups:
return None
if not in_group:
msg = (
'Some devices may not be accessible without being in the '
f'"{group}" user group.'
)
logger.warning(msg)
return msg
try:
groups = subprocess.check_output('groups').decode().split()
group_active = group in groups
except FileNotFoundError:
# groups command missing. Idk if any distro doesn't have it
# but if so, cover the case.
return None
if in_group and not group_active:
msg = (
f'You are in the "{group}" group, but your session is not yet '
'using it. Some devices may not be accessible. Please log out and '
'back in or restart'
)
logger.warning(msg)
return msg
return None
def check_injection_rights():
"""Check if the user may write into /dev/uinput."""
if not os.access('/dev/uinput', os.W_OK):
msg = (
'Rights to write to /dev/uinput are missing, keycodes cannot '
'be injected.'
)
logger.error(msg)
return msg
return None
def can_read_devices():
"""Get a list of problems before key-mapper can be used properly."""
if getpass.getuser() == 'root':
return []
input_check = check_group('input')
plugdev_check = check_group('plugdev')
# ubuntu. funnily, individual devices in /dev/input/ have write permitted.
if not is_service_running():
can_write = check_injection_rights()
else:
can_write = None
ret = [
check for check
in [can_write, input_check, plugdev_check]
if check is not None
]
return ret