2069057 - Add an engine setting to disable network requests made outside the Gecko network stack

Status: NEW

(Firefox for Android :: Privacy, task)

Description

[Andrew Creskey [:acreskey]]

Fenix warms up app-link DNS via InetAddress.getByName() before Gecko starts (see bug 2067891),
which resolves the host through the OS resolver and bypasses any proxy configured in Gecko.
Embedders like Tor Browser need a Settings flag to opt out of this and any future out-of-stack request as it can be a serious privacy leak.

See discussion in https://phabricator.services.mozilla.com/D322414

Comment 1

[Andrew Creskey [:acreskey]]

Would need someone with more Geckoview/Fenix experience, but I believe that we could implement this similar to other settings, e.g.

Declare
https://searchfox.org/firefox-main/rev/de4a22953e43a1579c62276e0b396cce92d359d5/mobile/android/android-components/components/concept/engine/src/main/java/mozilla/components/concept/engine/Settings.kt#144

Init
https://searchfox.org/firefox-main/rev/de4a22953e43a1579c62276e0b396cce92d359d5/mobile/android/android-components/components/concept/engine/src/main/java/mozilla/components/concept/engine/Settings.kt#314

etc.