1581947 - Support mDNS hostname obfuscation on Android

Status: RESOLVED FIXED

(Core :: WebRTC: Networking, enhancement, P3)

Description

[Dan Minor [:dminor]]

We need to determine if or when we would like to support mDNS hostname obfuscation on Android. From my initial research, using multicast on Android requires a specific permission (CHANGE_WIFI_MULTICAST_STATE) and according to the documentation can have an impact on battery life [1].

It it looks like mDNS hostname obfuscation is currently disabled for Chrome on Android [2]. I confirmed that with a fresh install of Chrome 77 on my phone. It also looks like Chrome uses the system DNS resolver and on Android it does not support mDNS [3].

[1] https://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock
[2] https://groups.google.com/forum/#!msg/discuss-webrtc/6stQXi72BEU/k3UCPGe1AQAJ
[3] https://bugs.chromium.org/p/chromium/issues/detail?id=405925#c69

Comment 1

[Andrew Aylett]

It looks like mDNS lookups are available on Android 12+ [1] so might this be possible to implement more cleanly now?

[1] https://www.androidpolice.com/android-mdns-local-hostname/ is linked from the Chromium bug tracker link in the description.

Comment 2

[Jim Mathies [:jimm]]

Already have this in our 2026 planning doc. Need to determine the priority here.

Comment 3

[Jim Mathies [:jimm]]

• chrome doesn't support this on android from our understanding.
• we want this, but it's not a slam dunk, in the past the API landscape did not allow us to support this.
• Needs a couple weeks of research and a tech brief.

Comment 4

[Jim Mathies [:jimm]]

This was implemented but the pref was never flipped. We're going to flip the pref in Nightly and do some testing.

Comment 5

[Dan Baker[:dbaker]]

Attachment: Bug 1581947 - Enabling mDNS obfuscate host address by default for all platforms.;r?ng

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d7ebd0a0226e
https://hg.mozilla.org/integration/autoland/rev/4d64ece0c970
Enabling mDNS obfuscate host address by default for all platforms.;r=ng

Comment 7

[amarc]

https://hg.mozilla.org/mozilla-central/rev/4d64ece0c970