Firejail is a SUID sandbox program that reduces the risk of security breaches by restricting the running environment of untrusted applications using Linux namespaces, seccomp-bpf and Linux capabilities. It allows a process and all its descendants to have their own private view of the globally shared kernel resources, such as the network stack, process table, mount table. Firejail can work in a SELinux or AppArmor environment, and it is integrated with Linux Control Groups.

When using Firejail's desktop integration features, all supported applications will run fully sandboxed. Opening hyperlinks from within another sandboxed application can become tedious. Until this functionality is natively supported, it is recommended to copy-paste hyperlinks from sandbox to sandbox (see e.g. #2228 and #2047). Work is underway to implement this via the newly introduced D-Bus filtering, but that's not in any firejail release yet.

The scripts in this repository implement a more user-friendly - still fully secure - way to relay certain traffic between firejailed applications. There is no D-Bus functionality involved, so the current profiles should work. The basic idea is to pass hyperlink data between sandboxes indirectly. Relying on a simple shell script, a URL is temporarily stored in the filesystem in a pre-determined location (which needs read-write access in the originating profile). A companion shell script uses inotifywait to pick up the URL from outside the sandbox and relays it to a fully firejailed handler application of choice.

Only 2 extra handlers are available:

• a BitTorrent handler that relays URL's from inside a sandboxed web browser to a configurable, fully sandboxed bittorrent application (defaults to local transmission-daemon)
• a Youtube handler that relays URL's from inside a sandboxed web browser to a configurable, fully sandboxed media player (defaults to mpv)

Both can be installed seperately, and the common settings file needs to be installed only once. There are no plans to support other firejail handlers in this repository. As such it is more a Proof-Of-Concept than a fully developed application. The rationale is quite simple, so users can copy/paste the scripts and edit them for a specific use-case.

For the Youtube handler your web browser will need an add-on like Greasemonkey, Tampermonkey or Violentmonkey, plus a user.js script to rewrite URL's on-the-fly into the supported fjyt protocol. An example fjyt.user.js is supplied, but might need additional editing.

Arch Linux users can install from the AUR: firejail-handler-extra.

On other distributions you'll need the following dependencies:

* firejail
* inotify-tools
* xdg-utils

* a firejail supported bittorrent application
* a firejail supported media player
* a firejail supported web browser

Clone the source code from the Git repository and install manually:

$ git clone https://github.com/glitsj16/firejail-handler-extra.git
$ cd firejail-handler-extra
$ sudo install -Dm755 ./firejail-handler-bittorrent /usr/bin/firejail-handler-bittorrent
$ sudo install -Dm755 ./firejail-handler-bittorrent-ctl /usr/bin/firejail-handler-bittorrent-ctl
$ sudo install -Dm644 ./firejail-handler-bittorrent.desktop /usr/share/applications/firejail-handler-bittorrent.desktop
$ sudo install -Dm644 ./firejail-handler-bittorrent-ctl.desktop /etc/xdg/autostart/firejail-handler-bittorrent-ctl.desktop
$ sudo install -Dm644 ./firejail-handler-settings-extra.inc /etc/firejail/firejail-handler-settings-extra.inc
$ sudo install -Dm755 ./firejail-handler-youtube /usr/bin/firejail-handler-youtube
$ sudo install -Dm755 ./firejail-handler-youtube-ctl /usr/bin/firejail-handler-youtube-ctl
$ sudo install -Dm644 ./firejail-handler-youtube.desktop /usr/share/applications/firejail-handler-youtube.desktop
$ sudo install -Dm644 ./firejail-handler-youtube-ctl.desktop /etc/xdg/autostart/firejail-handler-youtube-ctl.desktop

The scripts will look for user-provided settings in ~/.config/firejail/firejail-handler-settings-extra.inc first. If that file does not exist it will try /etc/firejail/firejail-handler-settings-extra.inc. Finally, if none of these locations exist, hard-coded defaults will be used.

• Enable the custom MimeType handlers and configure your web browser(s) accordingly.
• If the relevant firejail profile has the private-bin option, you will have to make sure to add everything that's needed for the handler script(s) to work inside the sandbox. The easiest way to achieve this is by creating a ~/.config/firejail/foo.local override and take care of the additional private-bin commands there.
• Re-login to autostart the inotifywait script(s) via the relevant XDG desktop file(s) or start things manually by other means.