first cut at implementing TURN

src/matrix/Session.js

@@ -513,6 +513,7 @@ export class Session {
             // TODO: what can we do if this throws?
             await txn.complete();
         }
+        await this._updateTurnServers();
         // enable session backup, this requests the latest backup version
         if (!this._keyBackup.get()) {
             if (dehydratedDevice) {
@@ -559,6 +560,18 @@ export class Session {
         }
     }
 
+    async _updateTurnServers() {
+        const turnServersData = await this._hsApi.getTurnServers().response();
+        this._callHandler.setTurnServers({
+            urls: turnServerData.uris,
+            username: turnServerData.username,
+            credential: turnServerData.password,
+        });
+        if (turnServersData.ttl > 0) {
+            setTimeout(this._updateTurnServers, turnServersData.ttl * 1000);
+        }
+    }
+
     async _getPendingEventsByRoom(txn) {
         const pendingEvents = await txn.pendingEvents.getAll();
         return pendingEvents.reduce((groups, pe) => {

src/matrix/calls/CallHandler.ts

@@ -75,6 +75,12 @@ export class CallHandler implements RoomStateHandler {
         this._loadCallEntries(callEntries, txn);
     }
 
+    async setTurnServers(turnServers: RTCIceServer) {
+        this.options.turnServers = turnServers;
+        this.groupCallOptions.turnServers = turnServers;
+        // TODO: we should update any ongoing peerconnections if the TURN server details have changed
+    }
+
     private async _getLoadTxn(): Promise<Transaction> {
         const names = this.options.storage.storeNames;
         const txn = await this.options.storage.readTxn([

src/matrix/net/HomeServerApi.ts

@@ -309,6 +309,10 @@ export class HomeServerApi {
     setAccountData(ownUserId: string, type: string, content: Record<string, any>, options?: BaseRequestOptions): IHomeServerRequest {
         return this._put(`/user/${encodeURIComponent(ownUserId)}/account_data/${encodeURIComponent(type)}`, {}, content, options);
     }
+
+    getTurnServer(options?: BaseRequestOptions): IHomeServerRequest {
+        return this._get(`/voip/turnServer`, undefined, undefined, options);
+    }
 }
 
 import {Request as MockRequest} from "../../mocks/Request.js";