876c155efb
These tests check that the built `pam_malcontent.so` module can be loaded using `dlopen()` and that it exports the right symbol. This should mean that PAM can load it and use it. Unfortunately, we can’t actually run the module, since PAM hard-codes its configuration path as being in `/etc`, and there seems to be no way to override that to load a dummy configuration from a test directory. So the only way to test the PAM module is to use a file system bind mount to fake `/etc` (which requires privileges); or to actually install it on your system and integrate it into your real PAM configuration. Neither of those are acceptable for a unit test. It might be possible to re-execute a test under `bwrap` (if installed) to achieve this, bind mounting a dummy `/etc/pam.d/dummy` service file into the subprocess’ mount namespace, and otherwise bind mounting `/` to `/`. It would need a mock malcontent D-Bus API to talk to. Something to experiment with another time. (See `_pam_init_handlers()` in https://github.com/linux-pam/linux-pam/blob/master/libpam/pam_handlers.c for details of how PAM modules are loaded.) Signed-off-by: Philip Withnall <withnall@endlessm.com> |
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|---|---|---|
| accounts-service | ||
| libmalcontent | ||
| malcontent-client | ||
| pam | ||
| po | ||
| subprojects | ||
| tools | ||
| .gitlab-ci.yml | ||
| .gitmodules | ||
| COPYING | ||
| NEWS | ||
| README.md | ||
| malcontent.doap | ||
| meson.build | ||
| meson_options.txt | ||
| template.test.in | ||
README.md
malcontent
malcontent implements support for restricting the type of content accessible to non-administrator accounts on a Linux system. Typically, when this is used, a non-administrator account will be for a child using the system; and the administrator accounts will be for the parents; and the content being filtered will be apps which are not suitable for the child to use, due to (for example) being too violent.
It provides an
accounts-service
vendor extension for storing an app filter to
restrict the child’s access to certain applications; and a simple library for
accessing and applying the app filter. This results in the policy being stored
in /var/lib/AccountsService/users/${user}, which is a key file readable and
writable only by the accounts-service daemon. Access to the data is mediated
through accounts-service’s D-Bus interface, which libmalcontent is a client
library for.
All the library APIs are currently unstable and are likely to change wildly.
Two kinds of policy are currently supported:
- A filter specifying whether installed applications are allowed to be run; this is typically set up to restrict access to a limited set of already-installed applications — but it can be set up to only allow access to a fixed list of applications and deny access to all others. Applications which are not currently installed are not subject to this filter.
- A set of mappings from OARS categories to
the maximum ratings for those categories which are permissible for a user to
install apps with. For example, a mapping of
violence-realistic=mildwould prevent any applications containing more than ‘mild’ violence from being installed. Applications which are already installed are not subject to this filter.
Additional policies may be added in future, such as filtering by content type or limiting the amount of time a user is allowed to use the system for.
Any application or service which provides the user with access to content which should be parentally filtered is responsible for querying the user’s parental controls filter and refusing to provide the content if not permitted by the filter. This could mean refusing to launch a flatpak app, hiding a search result in gnome-shell, or hiding an app in gnome-software because of its high OARS rating.
A sufficiently technically advanced user may always work around these parental controls. malcontent is not a mandatory access control (MAC) system like AppArmor or SELinux. However, its correct use by applications should provide enough of an obstacle to prevent users easily or accidentally having access to content which they shouldn’t.
Example usage
malcontent ships a malcontent-client application which can be used to get and
set parental controls policies for users.
$ # This sets the parental controls policy for user ‘philip’ to allow no \\
installation of apps with anything more than ‘none’ for realistic violence, \\
and to blacklist running the org.freedesktop.Bustle flatpak:
$ malcontent-client set philip \\
violence-realistic=none \\
app/org.freedesktop.Bustle/x86_64/stable
App filter for user 1000 set
With that policy in place, other applications which are aware of malcontent will apply the policy:
$ flatpak run org.freedesktop.Bustle
error: Running app/org.freedesktop.Bustle/x86_64/stable is not allowed by the policy set by your administrator
Dependencies
- accounts-service
- dbus-daemon
- gio-2.0 ≥ 2.60
- gio-unix-2.0 ≥ 2.60
- glib-2.0 ≥ 2.60
- gobject-2.0 ≥ 2.60
- polkit-gobject-1
Licensing
All code in this project is licensed under LGPL-2.1+. See COPYING for more details.
Bugs
Bug reports and patches should be filed in GitLab.