PSA How to Allow for Screen Sharing in Firefox when Firejail Sandbox is enabled

kagetora13 · July 12, 2022, 7:04pm

When firejail is enabled system wide in Gnome, you will not be able to share your desktop screen via Firefox.

Solution

This can be fixed by allowing the required DBUS message in Linux.

Create a local Firejail Firefox configuration file.

touch ~/.config/firejail/firefox.local

Add the following contents to the firefox.local file:

dbus-user.talk org.freedesktop.portal.Desktop

Use the following Test Page to verify Screen Capture is allowed.

https://mozilla.github.io/webrtc-landing/gum_test.html

Source:

github.com/netblue30/firejail

Screen sharing configuration on wayland

opened 10:26PM - 05 Jan 21 UTC

closed 08:04AM - 10 Feb 21 UTC

albinou

**Bug and expected behavior** - Run firefox with the firefox profile - Open ht…tps://mozilla.github.io/webrtc-landing/gum_test.html - Click on "Screen Capture" - firefox asks for permission to share the screen but nothing is displayed **Solution** This can be fixed by allowing the required DBUS message. This can be done by creating a `~/.config/firejail/firefox.local` file with the following content: ``` dbus-user.talk org.freedesktop.portal.Desktop ``` **There's no bug then?** No indeed, because I am not sure this DBUS message should be allowed by default. I am just wondering if/where this should be documented because it is not specific to firefox. Indeed, the same configuration could be required for other applications (like chromium, zoom, teams, ...). Don't hesitate to ask me to propose a PR, I would be happy to help.

https://wiki.archlinux.org/title/Screen_capture#Via_the_WebRTC_protocol
https://wiki.archlinux.org/title/PipeWire#WebRTC_screen_sharing