1421842 - Limit the amount of PCs per origin

Status: NEW

(Core :: WebRTC, enhancement, P3)

Description

[Nils Ohlmeier [:drno]]

Apparently there are some service and libraries out there which try to create PeerConnections as if they are free of costs.

This apparently can result in the browser tab crashing, e.g. https://github.com/ipfs/js-ipfs/issues/950

I think we should look into limiting the amount of PeerConnections a given origin is allowed to create to X

And we should also put in a higher limit for the whole browser so that about:webrtc only shows Y (where Y > X) connections to avoid wasting too much memory on lots of old, and probably closed connections.

Note: apparently the RTCPeerConnection constructor right now can not fail https://www.w3.org/TR/webrtc/#constructor

Comment 1

[Nils Ohlmeier [:drno]]

jib what do you think about adding a limit? 
I think we should also open an issue against the spec to allow a browser to reject the creation of yet another PeerConnection with a meaningful error code.

Comment 2

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

There is one. See https://github.com/w3c/webrtc-pc/issues/1670.

A limit makes sense to me, but we should probably track down the crash as well?

Comment 3

[Eric Rescorla (:ekr)]

A few comments:

1. A per-origin limit seems unwise. People will just shard, which is worse.
2. I agree we should not crash. Some method to avoid running out of memory is good, but it should be browser global

Comment 4

[Nils Ohlmeier [:drno]]

(In reply to Eric Rescorla (:ekr) from comment #3)
> 1. A per-origin limit seems unwise. People will just shard, which is worse.
> 2. I agree we should not crash. Some method to avoid running out of memory
> is good, but it should be browser global

Do you think per (second level) domain would be a possible alternative to browser global?

Comment 5

[Eric Rescorla (:ekr)]

No, I think people will cheat.

Comment 6

[Nils Ohlmeier [:drno]]

Browser global has the problem though that a single malicious or stupid page can prevent other legit services in other tabs/windows from working.

Comment 7

[Eric Rescorla (:ekr)]

I think rather than origin you want all the PCs that were started by a given page no matter what origin they came from. And I wouldn't have a limit but rather a warning like the slow script warning.