110 lines
4 KiB
Python
110 lines
4 KiB
Python
#
|
|
# screensaver.py - Screensaver management methods and data
|
|
#
|
|
# Copyright (C) 2014 Red Hat, Inc. 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, see <http://www.gnu.org/licenses/>.
|
|
#
|
|
"""The screensaver inhibition module.
|
|
|
|
The "screensaver" term includes the following effects, none of which we want during installation:
|
|
- locking the screen
|
|
- turning off the screen
|
|
- suspending the system
|
|
|
|
See also the origin bz: https://bugzilla.redhat.com/show_bug.cgi?id=928825
|
|
|
|
We are using the freedesktop D-Bus api for inhibiting the screensaver:
|
|
https://people.freedesktop.org/~hadess/idle-inhibition-spec/re01.html
|
|
|
|
Note this does NOT use the systemd / logind API with similar name and capability!
|
|
|
|
The D-Bus api lives on the session bus. Connections to the session bus must be made with the
|
|
effective UID of the login user, which in live installs is not the UID of anaconda. This means
|
|
we need to call seteuid while creating the proxy and making calls on the bus.
|
|
|
|
Additionally, at the time of writing, creating the proxy actually starts the session bus daemon
|
|
and so creates the bus. Conversely, when the proxy stops existing, the bus goes down.
|
|
|
|
The inhibition is in effect only if all of these conditions are met:
|
|
- The process called Inhibit on the session bus for the correct user.
|
|
- The process exists.
|
|
- The session bus exists.
|
|
- The process did not call UnInhibit on the session bus with the right cookie.
|
|
|
|
Altogether this means that once the proxy is correctly created, we call Inhibit, and then
|
|
the proxy object must exist as long as we want the inhibition to be in effect.
|
|
"""
|
|
import os
|
|
from dasbus.connection import SessionMessageBus
|
|
from dasbus.error import DBusError
|
|
from dasbus.identifier import DBusServiceIdentifier
|
|
from pyanaconda.anaconda_loggers import get_module_logger
|
|
log = get_module_logger(__name__)
|
|
|
|
__all__ = ["inhibit_screensaver", "uninhibit_screensaver"]
|
|
|
|
|
|
session_proxy = None
|
|
inhibit_id = None
|
|
|
|
|
|
class SetEuidFromPkexec():
|
|
"""Context manager to temporarily set euid from env. variable set by consolehelper.
|
|
|
|
Live installs use pkexec to run as root, which sets the original UID in $PKEXEC_UID.
|
|
"""
|
|
def __init__(self):
|
|
self.old_euid = None
|
|
|
|
def __enter__(self):
|
|
if "PKEXEC_UID" in os.environ:
|
|
self.old_euid = os.geteuid()
|
|
new_euid = int(os.environ["PKEXEC_UID"])
|
|
os.seteuid(new_euid)
|
|
return self
|
|
|
|
def __exit__(self, exc_type, exc_value, exc_traceback):
|
|
if self.old_euid is not None:
|
|
os.seteuid(self.old_euid)
|
|
self.old_euid = None
|
|
|
|
|
|
def inhibit_screensaver():
|
|
"""Inhibit the "screensaver" idle timer."""
|
|
log.info("Inhibiting screensaver.")
|
|
global session_proxy
|
|
global inhibit_id
|
|
try:
|
|
with SetEuidFromPkexec():
|
|
SCREENSAVER = DBusServiceIdentifier(
|
|
namespace=("org", "freedesktop", "ScreenSaver"),
|
|
message_bus=SessionMessageBus()
|
|
)
|
|
session_proxy = SCREENSAVER.get_proxy()
|
|
inhibit_id = session_proxy.Inhibit("anaconda", "Installing")
|
|
except DBusError as e:
|
|
log.warning("Unable to inhibit the screensaver: %s", e)
|
|
|
|
|
|
def uninhibit_screensaver():
|
|
"""Re-enable the "screensaver" idle timer."""
|
|
if session_proxy is None or inhibit_id is None:
|
|
return
|
|
log.info("Un-inhibiting screensaver.")
|
|
try:
|
|
with SetEuidFromPkexec():
|
|
session_proxy.UnInhibit(inhibit_id)
|
|
except (DBusError, KeyError) as e:
|
|
log.warning("Unable to uninhibit the screensaver: %s", e)
|