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Dbus

All dbus rules are labelled under the name of the given profiles that provide dbus data. If the profiles were going to change (a renaming, an architectural change), the dbus rules need to be updated accordingly.

Default system, session and accessibility bus access are provided with the abstraction:

  • abstractions/bus-system
  • abstractions/bus-session
  • abstractions/bus-accessibility

Dbus Abstractions

Access to common dbus interface is done using the abstractions under abstractions/bus/. They are kept minimal on purpose. The goal is not to give full talk access an interface but to provide a read-only like view of it. It may be required to have a look at the dbus interface documentation to check what method can be safely allowed.

For more access, simply use the dbus: talk directive.

Dbus Directive

We use a special directive to generate (when running make) more advanced dbus access.

Directive format

# dbus: ( own | talk ) bus=( system | session ) name=AARE [label=AARE] [interface=AARE] [path=AARE]

The directive format is on purpose very similar to apparmor dbus rules. However, there are some restrictions:

  • bus and name are mandatory and will break the build if ignored.
  • For the talk sub directive, profile name under a label is also mandatory
  • interface can optionally be given when it is different to the dbus path.
  • path can optionally be given when it is different to the dbus name.
  • It is still a comment: the rule must not end with a comma, multiline directive is not supported.

Example:

Allow owning a dbus interface:

apparmor.d/groups/network/NetworkManager

# dbus: own bus=system name=org.freedesktop.NetworkManager

Allow talking to a dbus interface on a given profile

apparmor.d/groups/gnome/gdm

# dbus: talk bus=system name=org.freedesktop.login1 label=systemd-logind