Disable ICE fallback based on well-known configuration

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/LegacyCallHandler.tsx

@@ -764,7 +764,6 @@ export default class LegacyCallHandler extends EventEmitter {
                 cancelButton: _t("action|ok"),
                 onFinished: (allow) => {
                     SettingsStore.setValue("fallbackICEServerAllowed", null, SettingLevel.DEVICE, allow);
-                    cli.setFallbackICEServerAllowed(!!allow);
                 },
             },
             undefined,

src/components/views/settings/tabs/user/VoiceUserSettingsTab.tsx

@@ -112,10 +112,6 @@ export default class VoiceUserSettingsTab extends React.Component<{}, IState> {
         this.context.setForceTURN(!p2p);
     };
 
-    private changeFallbackICEServerAllowed = (allow: boolean): void => {
-        this.context.setFallbackICEServerAllowed(allow);
-    };
-
     private renderDeviceOptions(devices: Array<MediaDeviceInfo>, category: MediaDeviceKindEnum): Array<JSX.Element> {
         return devices.map((d) => {
             return (
@@ -226,7 +222,7 @@ export default class VoiceUserSettingsTab extends React.Component<{}, IState> {
                                 server: new URL(FALLBACK_ICE_SERVER).pathname,
                             })}
                             level={SettingLevel.DEVICE}
-                            onChange={this.changeFallbackICEServerAllowed}
+                            hideIfCannotSet
                         />
                     </SettingsSubsection>
                 </SettingsSection>

src/settings/Settings.tsx

@@ -37,6 +37,7 @@ import ServerSupportUnstableFeatureController from "./controllers/ServerSupportU
 import { WatchManager } from "./WatchManager";
 import { CustomTheme } from "../theme";
 import AnalyticsController from "./controllers/AnalyticsController";
+import FallbackIceServerController from "./controllers/FallbackIceServerController";
 
 export const defaultWatchManager = new WatchManager();
 
@@ -992,6 +993,7 @@ export const SETTINGS: { [setting: string]: ISetting } = {
         description: _td("settings|voip|enable_fallback_ice_server_description"),
         // This is a tri-state value, where `null` means "prompt the user".
         default: null,
+        controller: new FallbackIceServerController(),
     },
     "showImages": {
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,

src/settings/controllers/FallbackIceServerController.ts

@@ -0,0 +1,52 @@
+/*
+Copyright 2024 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { ClientEvent, IClientWellKnown, MatrixClient } from "matrix-js-sdk/src/matrix";
+
+import { SettingLevel } from "../SettingLevel";
+import SettingsStore from "../SettingsStore.ts";
+import MatrixClientBackedController from "./MatrixClientBackedController.ts";
+
+/**
+ * Settings controller for the fallback ICE server setting.
+ * This setting may be forcibly disabled by well-known value ["io.element.voip"]["disable_fallback_ice"].
+ * This controller will update the MatrixClient's knowledge when the setting is changed.
+ */
+export default class FallbackIceServerController extends MatrixClientBackedController {
+    private disabled = false;
+
+    public constructor() {
+        super();
+    }
+
+    private checkWellKnown = (wellKnown: IClientWellKnown): void => {
+        this.disabled = !!wellKnown["io.element.voip"]?.["disable_fallback_ice"];
+    };
+
+    protected async initMatrixClient(newClient: MatrixClient, oldClient?: MatrixClient): Promise<void> {
+        oldClient?.off(ClientEvent.ClientWellKnown, this.checkWellKnown);
+        newClient.on(ClientEvent.ClientWellKnown, this.checkWellKnown);
+        const wellKnown = newClient.getClientWellKnown();
+        if (wellKnown) this.checkWellKnown(wellKnown);
+    }
+
+    public getValueOverride(): any {
+        if (this.disabled) {
+            return false;
+        }
+
+        return null; // no override
+    }
+
+    public get settingDisabled(): boolean | string {
+        return this.disabled;
+    }
+
+    public onChange(_level: SettingLevel, _roomId: string | null, _newValue: any): void {
+        this.client?.setFallbackICEServerAllowed(!!SettingsStore.getValue("fallbackICEServerAllowed"));
+    }
+}