UDP sockets don't bind to the right interface

[bemasc]

The freedom UDP socket API allows the caller to bind to a particular interface, identified by its IP address. Unfortunately, the Firefox implementation ignores this and effectively just binds to 0.0.0.0.

[trevj]

Some more info...

Here's the call to bind the socket: https://github.com/freedomjs/freedom-for-firefox/blob/master/providers/core.udpsocket.js#L13

We should be able to use initWithAddress to specify a particular interface, although I wasn't able to quickly figure out how to pass a NetAddr argument:

• https://dxr.mozilla.org/mozilla-central/source/netwerk/base/nsIUDPSocket.idl#61
• https://dxr.mozilla.org/mozilla-central/source/netwerk/base/nsUDPSocket.cpp#762

[bemasc]

Unfortunately, initWithAddress is marked [noscript], so we can't use it from JS. The best option I could see for now is to set the aLoopbackOnly argument to true if the user asks to bind to localhost.

I filed a mozilla bug to complain about this: https://bugzilla.mozilla.org/show_bug.cgi?id=1178427

[trevj]

That's unfortunate but thanks for following up on this!

Does this affect our ability to run holographic ICE on Firefox?

[bemasc]

I suspect this will prevent us from doing IPv6 in Firefox. That's the only major issue I foresee.