feat: allow passing a function for rtcConfiguration (#2590)

In order to allow refreshing STUN/TURN credentials between dials,
allow passing a function that returns rtc config.

Fixes #2554

packages/transport-webrtc/src/private-to-private/transport.ts

@@ -19,7 +19,7 @@ export const SIGNALING_PROTO_ID = '/webrtc-signaling/0.0.1'
 const INBOUND_CONNECTION_TIMEOUT = 30 * 1000
 
 export interface WebRTCTransportInit {
-  rtcConfiguration?: RTCConfiguration
+  rtcConfiguration?: RTCConfiguration | (() => RTCConfiguration | Promise<RTCConfiguration>)
   dataChannel?: DataChannelOptions
 
   /**
@@ -134,7 +134,7 @@ export class WebRTCTransport implements Transport, Startable {
     this.log.trace('dialing address: %a', ma)
 
     const { remoteAddress, peerConnection, muxerFactory } = await initiateConnection({
-      rtcConfiguration: this.init.rtcConfiguration,
+      rtcConfiguration: typeof this.init.rtcConfiguration === 'function' ? await this.init.rtcConfiguration() : this.init.rtcConfiguration,
       dataChannel: this.init.dataChannel,
       multiaddr: ma,
       dataChannelOptions: this.init.dataChannel,
@@ -166,7 +166,7 @@ export class WebRTCTransport implements Transport, Startable {
 
   async _onProtocol ({ connection, stream }: IncomingStreamData): Promise<void> {
     const signal = AbortSignal.timeout(this.init.inboundConnectionTimeout ?? INBOUND_CONNECTION_TIMEOUT)
-    const peerConnection = new RTCPeerConnection(this.init.rtcConfiguration)
+    const peerConnection = new RTCPeerConnection(typeof this.init.rtcConfiguration === 'function' ? await this.init.rtcConfiguration() : this.init.rtcConfiguration)
     const muxerFactory = new DataChannelMuxerFactory(this.components, {
       peerConnection,
       dataChannelOptions: this.init.dataChannel

packages/transport-webrtc/src/private-to-public/transport.ts

@@ -52,6 +52,7 @@ export interface WebRTCMetrics {
 }
 
 export interface WebRTCTransportDirectInit {
+  rtcConfiguration?: RTCConfiguration | (() => RTCConfiguration | Promise<RTCConfiguration>)
   dataChannel?: DataChannelOptions
 }
 
@@ -137,7 +138,10 @@ export class WebRTCDirectTransport implements Transport {
       hash: sdp.toSupportedHashFunction(remoteCerthash.name)
     } as any)
 
-    const peerConnection = new RTCPeerConnection({ certificates: [certificate] })
+    const peerConnection = new RTCPeerConnection({
+      ...(typeof this.init.rtcConfiguration === 'function' ? await this.init.rtcConfiguration() : this.init.rtcConfiguration ?? {}),
+      certificates: [certificate]
+    })
 
     try {
       // create data channel for running the noise handshake. Once the data channel is opened,