1758306 - Handle <all_urls> used as an API permissions in MV3 properly

Status: NEW

(WebExtensions :: General, enhancement, P2)

Description

[Tomislav Jovanovic :zombie]

Unfortunately, we treat <all_urls> as an API permission as well, and those cases will need special handling for bug 1745818.

Comment 1

[Tomislav Jovanovic :zombie]

It seems we only have a few uses of <all_urls> as an API permission left:

https://searchfox.org/mozilla-central/search?q=all_urlsPermission
https://searchfox.org/mozilla-central/search?q=all_urls&path=components%2Fextensions%2Fschemas

I plan to stop adding it to the api permissions, and instead change the existing checks to origin permissions checks.

Comment 2

[Rob Wu [:robwu]]

Other uses:

• drawWindow method - https://searchfox.org/mozilla-central/rev/0ffae75b690219858e5a45a39f8759a8aee7b9a2/dom/canvas/CanvasUtils.cpp#290
• Reading from canvases - https://searchfox.org/mozilla-central/rev/0ffae75b690219858e5a45a39f8759a8aee7b9a2/dom/html/HTMLCanvasElement.cpp#1166-1167
• Cross-origin info in PerformanceObserver - https://searchfox.org/mozilla-central/rev/0ffae75b690219858e5a45a39f8759a8aee7b9a2/dom/performance/PerformanceResourceTiming.cpp#131-133

I think that it's fine to drop the first and third use of <all_urls>, and at most keep the second for extension documents (not content scripts given the efforts at bug 1578405).

Comment 3

[Shane Caraveo (:mixedpuppy)]

Why is it fine to drop canvas support?

Comment 4

[Rob Wu [:robwu]]

drawWindow is deprecated (bug 1696976) - https://searchfox.org/mozilla-central/rev/dc09246dfbfd8dafeb6d55ebee18a6294d525443/dom/canvas/CanvasRenderingContext2D.cpp#5147-5150

Comment 5

[Rob Wu [:robwu]]

Note: bug 1957794 has an extension that is most likely affected by this.

At install time, we fix up MV2 <all_urls> permissions at https://searchfox.org/mozilla-central/rev/d602f8558872d133dc9240a01cd25d0898c58e5a/toolkit/components/extensions/Extension.sys.mjs#1921-1923

In MV3, we skip that logic at first, but add origins in _setupStartupPermissions at https://searchfox.org/mozilla-central/rev/d602f8558872d133dc9240a01cd25d0898c58e5a/toolkit/components/extensions/Extension.sys.mjs#3965-3979 . Notably, the special <all_urls> check + addition is missing.

When an optional permission is toggled (whether via about:addons UI or the permissions API), it is added/removed via https://searchfox.org/mozilla-central/rev/d602f8558872d133dc9240a01cd25d0898c58e5a/toolkit/components/extensions/ExtensionPermissions.sys.mjs#415-423

Tom, do you still plan to fix this bug as proposed (replacing use of all_urls API permission with a host permission check), or would the simpler approach of adding <all_urls> from _setupStartupPermissions be acceptable in your opinion?