libmalcontent implements parental controls support which can be used by applications to filter or limit the access of child accounts to inappropriate content.
Go to file
Philip Withnall cd36d90091 malcontent-control: Drop ‘Restrict Application Installation for Others’
This simplifies the UI, as nobody really understood the difference
between ‘Restrict Application Installation’ and ‘Restrict Application
Installation for Others’. Now there’s just a ‘Restrict Application
Installation’ checkbox, which controls application installation in the
home and system flatpak repos.

The underlying app-filter representation in libmalcontent still supports
restricting installation to them separately, but the UI will always set
them to the same value.

There is a suggestion that we may want to support user repos again in
future iff the user has added a remote to their user repo. However,
figuring that out for other users (which is what the admin would have to
do when setting this all up) starts to get tricky with permissions for
reading other users’ home directories. Skip that for the moment — we can
reconsider adding that option in future if someone argues a case for it.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Fixes: #30
2020-11-15 17:31:21 +00:00
.gitlab-ci ci: Use pre-built Docker images for CI builds 2020-07-21 11:58:51 +01:00
accounts-service Add option to tweak privileged group in polkit rules 2020-06-18 03:35:36 +07:00
build-aux build: Only update post-install caches when they exist 2020-04-05 10:52:05 +02:00
help malcontent-control: Drop ‘Restrict Application Installation for Others’ 2020-11-15 17:31:21 +00:00
libmalcontent libmalcontent: Add mct_app_filter_equal() comparison method 2020-11-03 17:49:00 +00:00
libmalcontent-ui malcontent-control: Drop ‘Restrict Application Installation for Others’ 2020-11-15 17:31:21 +00:00
malcontent-client malcontent-client: Add newer subcommands and examples to man page 2020-10-27 18:26:51 +00:00
malcontent-control malcontent-control: Drop ‘Restrict Application Installation for Others’ 2020-11-15 17:31:21 +00:00
pam tests: Respect pamlibdir in installed tests 2020-04-28 13:57:29 +01:00
po Update Polish translation 2020-10-25 09:26:13 +01:00
subprojects subprojects: Limit depth when cloning 2020-07-21 12:43:24 +01:00
tools build: Port meson-make-symlink script to Python 2019-12-02 22:57:13 +08:00
.gitlab-ci.yml ci: Use pre-built Docker images for CI builds 2020-07-21 11:58:51 +01:00
COPYING Initial commit of README and COPYING 2018-09-24 15:35:58 +01:00
COPYING-DOCS help: Add a basic user manual for malcontent-control 2020-04-03 15:08:47 +01:00
NEWS 0.9.0 2020-09-03 12:03:51 +01:00
README.md tree-wide: Replace usages of whitelist/blacklist 2020-06-09 15:35:21 -07:00
malcontent.doap docs: Port README to Markdown and update a few references 2019-02-26 17:48:03 +00:00
meson.build build: Bump version for new release series 2020-10-20 12:41:05 +01:00
meson_options.txt Add option to tweak privileged group in polkit rules 2020-06-18 03:35:36 +07:00
template.test.in libeos-parental-controls: Add placeholder unit tests 2018-10-06 00:48:36 +01:00

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 childs access to certain applications; a simple library for accessing and applying the app filter; and a UI program (malcontent-control) for viewing and changing the parental controls settings on users.

The parental controls policy is 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-services 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=mild would 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 users 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 shouldnt.

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 blocklist 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

Development

When developing malcontent, you should be able to run an uninstalled version of malcontent-client or malcontent-control, as long as the polkit files from accounts-service/ and malcontent-control/org.freedesktop.MalcontentControl.policy.in have been installed system-wide (typically under /usr/share/polkit-1) where your system copy of polkitd can find them.

Dependencies

  • accounts-service
  • appstream-glib
  • dbus-daemon
  • flatpak
  • gio-2.0 ≥ 2.60
  • gio-unix-2.0 ≥ 2.60
  • glib-2.0 ≥ 2.60
  • gobject-2.0 ≥ 2.60
  • gtk+-3.0
  • polkit-gobject-1

Licensing

All code in the libraries in this project is licensed under LGPL-2.1+. Code in the malcontent-control application is licensed under GPL-2.0+. See COPYING and the copyright headers in individual files for more details.

Bugs

Bug reports and patches should be filed in GitLab.