Disable ICE fallback based on well-known configuration

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"));
+    }
+}

src/settings/controllers/MatrixClientBackedController.ts

@@ -18,15 +18,15 @@ import SettingController from "./SettingController";
  * This class performs no logic and should be overridden.
  */
 export default abstract class MatrixClientBackedController extends SettingController {
-    private static _matrixClient: MatrixClient;
+    private static _matrixClient?: MatrixClient;
     private static instances: MatrixClientBackedController[] = [];
 
     public static set matrixClient(client: MatrixClient) {
         const oldClient = MatrixClientBackedController._matrixClient;
         MatrixClientBackedController._matrixClient = client;
 
         for (const instance of MatrixClientBackedController.instances) {
-            instance.initMatrixClient(oldClient, client);
+            instance.initMatrixClient(client, oldClient);
         }
     }
 
@@ -36,9 +36,9 @@ export default abstract class MatrixClientBackedController extends SettingContro
         MatrixClientBackedController.instances.push(this);
     }
 
-    public get client(): MatrixClient {
+    public get client(): MatrixClient | undefined {
         return MatrixClientBackedController._matrixClient;
     }
 
-    protected abstract initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient): void;
+    protected abstract initMatrixClient(newClient: MatrixClient, oldClient?: MatrixClient): void;
 }

src/settings/controllers/ServerSupportUnstableFeatureController.ts

@@ -6,8 +6,6 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import { MatrixClient } from "matrix-js-sdk/src/matrix";
-
 import { SettingLevel } from "../SettingLevel";
 import MatrixClientBackedController from "./MatrixClientBackedController";
 import { WatchManager } from "../WatchManager";
@@ -53,9 +51,9 @@ export default class ServerSupportUnstableFeatureController extends MatrixClient
         this.watchers.notifyUpdate(this.settingName, null, level, settingValue);
     }
 
-    protected async initMatrixClient(oldClient: MatrixClient, newClient: MatrixClient): Promise<void> {
+    protected async initMatrixClient(): Promise<void> {
         // Check for stable version support first
-        if (this.stableVersion && (await this.client.isVersionSupported(this.stableVersion))) {
+        if (this.stableVersion && (await this.client!.isVersionSupported(this.stableVersion))) {
             this.disabled = false;
             return;
         }
@@ -66,7 +64,7 @@ export default class ServerSupportUnstableFeatureController extends MatrixClient
         for (const featureGroup of this.unstableFeatureGroups) {
             const featureSupportList = await Promise.all(
                 featureGroup.map(async (feature) => {
-                    const isFeatureSupported = await this.client.doesServerSupportUnstableFeature(feature);
+                    const isFeatureSupported = await this.client!.doesServerSupportUnstableFeature(feature);
                     return isFeatureSupported;
                 }),
             );

test/settings/controllers/FallbackIceServerController-test.ts

@@ -0,0 +1,57 @@
+/*
+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 fetchMockJest from "fetch-mock-jest";
+import { ClientEvent, MatrixClient } from "matrix-js-sdk/src/matrix";
+
+import { SettingLevel } from "../../../src/settings/SettingLevel";
+import FallbackIceServerController from "../../../src/settings/controllers/FallbackIceServerController.ts";
+import MatrixClientBackedController from "../../../src/settings/controllers/MatrixClientBackedController.ts";
+import SettingsStore from "../../../src/settings/SettingsStore.ts";
+
+describe("FallbackIceServerController", () => {
+    beforeEach(() => {
+        fetchMockJest.get("https://matrix.org/_matrix/client/versions", { versions: ["v1.4"] });
+    });
+
+    afterEach(() => {
+        jest.restoreAllMocks();
+    });
+
+    it("should update MatrixClient's state when the setting is updated", async () => {
+        const client = new MatrixClient({
+            baseUrl: "https://matrix.org",
+            userId: "@alice:matrix.org",
+            accessToken: "token",
+        });
+        MatrixClientBackedController.matrixClient = client;
+
+        expect(client.isFallbackICEServerAllowed()).toBeFalsy();
+        await SettingsStore.setValue("fallbackICEServerAllowed", null, SettingLevel.DEVICE, true);
+        expect(client.isFallbackICEServerAllowed()).toBeTruthy();
+    });
+
+    it("should force the setting to be disabled if disable_fallback_ice=true", async () => {
+        const controller = new FallbackIceServerController();
+        const client = new MatrixClient({
+            baseUrl: "https://matrix.org",
+            userId: "@alice:matrix.org",
+            accessToken: "token",
+        });
+        MatrixClientBackedController.matrixClient = client;
+        expect(controller.settingDisabled).toBeFalsy();
+
+        client["clientWellKnown"] = {
+            "io.element.voip": {
+                disable_fallback_ice: true,
+            },
+        };
+        client.emit(ClientEvent.ClientWellKnown, client["clientWellKnown"]);
+
+        expect(controller.settingDisabled).toBeTruthy();
+    });
+});