From 34b21a25987656136097262877e2b05595b9ae25 Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Tue, 22 Mar 2022 18:22:18 +0100
Subject: [PATCH] Add preference forceRelay.

This may be useful to get around network blocks in some cases.
---
 static/galene.js   | 18 ++++++++++++++++++
 static/protocol.js | 26 ++++++++++++++++++++++++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/static/galene.js b/static/galene.js
index 560cb74..5e56d8e 100644
--- a/static/galene.js
+++ b/static/galene.js
@@ -47,6 +47,7 @@ let token = null;
  * @property {string} [filter]
  * @property {boolean} [preprocessing]
  * @property {boolean} [hqaudio]
+ * @property {boolean} [forceRelay]
  */
 
 /** @type{settings} */
@@ -324,6 +325,22 @@ async function gotConnected(username) {
     }
 }
 
+/**
+ * @this {ServerConnection}
+ * @param {boolean} up
+ */
+function onPeerConnection(up) {
+    if(!getSettings().forceRelay)
+        return null;
+    let old = this.rtcConfiguration;
+    /** @type {RTCConfiguration} */
+    let conf = {};
+    for(let key in old)
+        conf[key] = old[key];
+    conf.iceTransportPolicy = 'relay';
+    return conf;
+}
+
 /**
  * @this {ServerConnection}
  * @param {number} code
@@ -3827,6 +3844,7 @@ async function serverConnect() {
         serverConnection.close();
     serverConnection = new ServerConnection();
     serverConnection.onconnected = gotConnected;
+    serverConnection.onpeerconnection = onPeerConnection;
     serverConnection.onclose = gotClose;
     serverConnection.ondownstream = gotDownStream;
     serverConnection.onuser = gotUser;
diff --git a/static/protocol.js b/static/protocol.js
index bd11f8e..ff4f127 100644
--- a/static/protocol.js
+++ b/static/protocol.js
@@ -151,6 +151,14 @@ function ServerConnection() {
      * @type{(this: ServerConnection, code: number, reason: string) => void}
      */
     this.onclose = null;
+    /**
+     * onpeerconnection is called before we establish a new peer connection.
+     * It may either return null, or a new RTCConfiguration that overrides
+     * the value obtained from the server.
+     *
+     * @type{(this: ServerConnection, up: boolean) => RTCConfiguration}
+     */
+    this.onpeerconnection = null;
     /**
      * onuser is called whenever a user in the group changes.  The users
      * array has already been updated.
@@ -512,6 +520,19 @@ ServerConnection.prototype.findByLocalId = function(localId) {
     return null;
 }
 
+/**
+ * @param {boolean} up
+ * @returns {RTCConfiguration}
+ */
+ServerConnection.prototype.getRTCConfiguration = function(up) {
+    if(this.onpeerconnection) {
+        let conf = this.onpeerconnection.call(this, up);
+        if(conf !== null)
+            return conf;
+    }
+    return this.rtcConfiguration;
+}
+
 /**
  * newUpStream requests the creation of a new up stream.
  *
@@ -529,7 +550,8 @@ ServerConnection.prototype.newUpStream = function(localId) {
     if(typeof RTCPeerConnection === 'undefined')
         throw new Error("This browser doesn't support WebRTC");
 
-    let pc = new RTCPeerConnection(sc.rtcConfiguration);
+
+    let pc = new RTCPeerConnection(sc.getRTCConfiguration(true));
     if(!pc)
         throw new Error("Couldn't create peer connection");
 
@@ -685,7 +707,7 @@ ServerConnection.prototype.gotOffer = async function(id, label, source, username
     if(!c) {
         let pc;
         try {
-            pc = new RTCPeerConnection(sc.rtcConfiguration);
+            pc = new RTCPeerConnection(sc.getRTCConfiguration(false));
         } catch(e) {
             console.error(e);
             sc.send({