You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
184 lines
6.5 KiB
184 lines
6.5 KiB
#
|
|
# Copyright (C) 2013 Red Hat, Inc.
|
|
#
|
|
# This copyrighted material is made available to anyone wishing to use,
|
|
# modify, copy, or redistribute it subject to the terms and conditions of
|
|
# the GNU General Public License v.2, or (at your option) any later version.
|
|
# This program is distributed in the hope that it will be useful, but WITHOUT
|
|
# ANY WARRANTY expressed or implied, including the implied warranties 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. Any Red Hat trademarks that are incorporated in the
|
|
# source code or documentation are not subject to the GNU General Public
|
|
# License and may only be used or replicated with the express permission of
|
|
# Red Hat, Inc.
|
|
#
|
|
# Red Hat Author(s): Vratislav Podzimek <vpodzime@redhat.com>
|
|
#
|
|
|
|
"""Module providing thread-safe and mainloop-safe DBus operations."""
|
|
|
|
import gi
|
|
gi.require_version("GLib", "2.0")
|
|
gi.require_version("Gio", "2.0")
|
|
|
|
from gi.repository import GLib, Gio
|
|
|
|
import os
|
|
from pyanaconda.constants import DEFAULT_DBUS_TIMEOUT
|
|
|
|
DBUS_PROPS_IFACE = "org.freedesktop.DBus.Properties"
|
|
|
|
class SafeDBusError(Exception):
|
|
"""Class for exceptions defined in this module."""
|
|
|
|
pass
|
|
|
|
class DBusCallError(SafeDBusError):
|
|
"""Class for the errors related to calling methods over DBus."""
|
|
|
|
pass
|
|
|
|
class DBusPropertyError(DBusCallError):
|
|
"""Class for the errors related to getting property values over DBus."""
|
|
|
|
pass
|
|
|
|
def get_new_system_connection():
|
|
"""Return a new connection to the system bus."""
|
|
|
|
return Gio.DBusConnection.new_for_address_sync(
|
|
Gio.dbus_address_get_for_bus_sync(Gio.BusType.SYSTEM, None),
|
|
Gio.DBusConnectionFlags.AUTHENTICATION_CLIENT|
|
|
Gio.DBusConnectionFlags.MESSAGE_BUS_CONNECTION,
|
|
None, None)
|
|
|
|
def get_new_session_connection():
|
|
"""
|
|
Get a connection handle for the per-user-login-session message bus.
|
|
|
|
!!! RUN THIS EARLY !!! like, before any other threads start. 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 in this method, and doing that after threads have started will
|
|
probably do something weird.
|
|
|
|
Live installs use consolehelper to run as root, which sets the original
|
|
UID in $USERHELPER_UID.
|
|
|
|
:return: the session connection handle
|
|
:rtype: Gio.DBusConnection
|
|
:raise DBusCallError: if some DBus related error appears
|
|
:raise OSError: if unable to set the effective UID
|
|
"""
|
|
|
|
old_euid = None
|
|
if "USERHELPER_UID" in os.environ:
|
|
old_euid = os.geteuid()
|
|
os.seteuid(int(os.environ["USERHELPER_UID"]))
|
|
|
|
try:
|
|
connection = Gio.DBusConnection.new_for_address_sync(
|
|
Gio.dbus_address_get_for_bus_sync(Gio.BusType.SESSION, None),
|
|
Gio.DBusConnectionFlags.AUTHENTICATION_CLIENT|
|
|
Gio.DBusConnectionFlags.MESSAGE_BUS_CONNECTION,
|
|
None, None)
|
|
except GLib.GError as gerr:
|
|
raise DBusCallError("Unable to connect to session bus: %s", gerr)
|
|
finally:
|
|
if old_euid is not None:
|
|
os.seteuid(old_euid)
|
|
|
|
if connection.is_closed():
|
|
raise DBusCallError("Connection is closed")
|
|
|
|
return connection
|
|
|
|
def call_sync(service, obj_path, iface, method, args,
|
|
connection=None):
|
|
"""
|
|
Safely call a given method on a given object of a given service over DBus
|
|
passing given arguments. If a connection is given, it is used, otherwise a
|
|
new connection is established. Safely means that it is a synchronous,
|
|
thread-safe call not using any main loop.
|
|
|
|
:param service: DBus service to use
|
|
:type service: str
|
|
:param obj_path: object path of the object to call method on
|
|
:type obj_path: str
|
|
:param iface: interface to use
|
|
:type iface: str
|
|
:param method: name of the method to call
|
|
:type method: str
|
|
:param args: arguments to pass to the method
|
|
:type args: GVariant
|
|
:param connection: connection to use (if None, a new connection is
|
|
established)
|
|
:type connection: Gio.DBusConnection
|
|
:return: unpacked value returned by the method
|
|
:rtype: tuple with elements that depend on the method
|
|
:raise DBusCallError: if some DBus related error appears
|
|
|
|
"""
|
|
|
|
if not connection:
|
|
try:
|
|
connection = get_new_system_connection()
|
|
except GLib.GError as gerr:
|
|
raise DBusCallError("Unable to connect to system bus: %s", gerr)
|
|
|
|
if connection.is_closed():
|
|
raise DBusCallError("Connection is closed")
|
|
|
|
try:
|
|
ret = connection.call_sync(service, obj_path, iface, method, args,
|
|
None, Gio.DBusCallFlags.NONE,
|
|
DEFAULT_DBUS_TIMEOUT, None)
|
|
except GLib.GError as gerr:
|
|
msg = "Failed to call %s method on %s with %s arguments: %s" % \
|
|
(method, obj_path, args, gerr.message)
|
|
raise DBusCallError(msg)
|
|
|
|
if ret is None:
|
|
msg = "No return from %s method on %s with %s arguments" % \
|
|
(method, obj_path, args)
|
|
raise DBusCallError(msg)
|
|
|
|
return ret.unpack()
|
|
|
|
def get_property_sync(service, obj_path, iface, prop_name,
|
|
connection=None):
|
|
"""
|
|
Get value of a given property of a given object provided by a given service.
|
|
|
|
:param service: DBus service to use
|
|
:type service: str
|
|
:param obj_path: object path
|
|
:type obj_path: str
|
|
:param iface: interface to use
|
|
:type iface: str
|
|
:param prop_name: name of the property
|
|
:type prop_name: str
|
|
:param connection: connection to use (if None, a new connection is
|
|
established)
|
|
:type connection: Gio.DBusConnection
|
|
:return: unpacked value of the property
|
|
:rtype: tuple with elements that depend on the type of the property
|
|
:raise DBusCallError: when the internal dbus_call_safe_sync invocation
|
|
raises an exception
|
|
:raise DBusPropertyError: when the given object doesn't have the given
|
|
property
|
|
|
|
"""
|
|
|
|
args = GLib.Variant('(ss)', (iface, prop_name))
|
|
ret = call_sync(service, obj_path, DBUS_PROPS_IFACE, "Get", args,
|
|
connection)
|
|
if ret is None:
|
|
msg = "No value for the %s object's property %s" % (obj_path, prop_name)
|
|
raise DBusPropertyError(msg)
|
|
|
|
return ret
|