mobile: prevent WebRTC call failure/hanging when webview "failed" state happens before 30 sec timeout (#1866)

* mobile: do not end calls

* better way of continue connection and end with timeout

* making data classes instead of classes for making logs informative

* refactor

* update webrtc package version

* refactor

* fix

* clear conneciton timeout on disconnection

* refactor

* v0.2.1

---------

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

apps/android/app/src/main/assets/www/call.js

@@ -22,6 +22,7 @@ var TransformOperation;
     TransformOperation["Decrypt"] = "decrypt";
 })(TransformOperation || (TransformOperation = {}));
 let activeCall;
+let answerTimeout = 30000;
 const processCommand = (function () {
     const defaultIceServers = [
         { urls: ["stun:stun.simplex.im:443"] },
@@ -100,9 +101,16 @@ const processCommand = (function () {
         const iceCandidates = getIceCandidates(pc, config);
         const call = { connection: pc, iceCandidates, localMedia: mediaType, localCamera, localStream, remoteStream, aesKey, useWorker };
         await setupMediaStreams(call);
+        let connectionTimeout = setTimeout(connectionHandler, answerTimeout);
         pc.addEventListener("connectionstatechange", connectionStateChange);
         return call;
         async function connectionStateChange() {
+            // "failed" means the second party did not answer in time (15 sec timeout in Chrome WebView)
+            // See https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/p2p/base/p2p_constants.cc;l=70)
+            if (pc.connectionState !== "failed")
+                connectionHandler();
+        }
+        async function connectionHandler() {
             sendMessageToNative({
                 resp: {
                     type: "connection",
@@ -115,6 +123,7 @@ const processCommand = (function () {
                 },
             });
             if (pc.connectionState == "disconnected" || pc.connectionState == "failed") {
+                clearConnectionTimeout();
                 pc.removeEventListener("connectionstatechange", connectionStateChange);
                 if (activeCall) {
                     setTimeout(() => sendMessageToNative({ resp: { type: "ended" } }), 0);
@@ -122,6 +131,7 @@ const processCommand = (function () {
                 endCall();
             }
             else if (pc.connectionState == "connected") {
+                clearConnectionTimeout();
                 const stats = (await pc.getStats());
                 for (const stat of stats.values()) {
                     const { type, state } = stat;
@@ -141,6 +151,12 @@ const processCommand = (function () {
                 }
             }
         }
+        function clearConnectionTimeout() {
+            if (connectionTimeout) {
+                clearTimeout(connectionTimeout);
+                connectionTimeout = undefined;
+            }
+        }
     }
     function serialize(x) {
         return LZString.compressToBase64(JSON.stringify(x));

apps/android/app/src/main/java/chat/simplex/app/views/call/WebRTC.kt

@@ -62,39 +62,39 @@ enum class CallState {
   }
 }
 
-@Serializable class WVAPICall(val corrId: Int? = null, val command: WCallCommand)
+@Serializable data class WVAPICall(val corrId: Int? = null, val command: WCallCommand)
-@Serializable class WVAPIMessage(val corrId: Int? = null, val resp: WCallResponse, val command: WCallCommand? = null)
+@Serializable data class WVAPIMessage(val corrId: Int? = null, val resp: WCallResponse, val command: WCallCommand? = null)
 
 @Serializable
 sealed class WCallCommand {
   @Serializable @SerialName("capabilities") object Capabilities: WCallCommand()
-  @Serializable @SerialName("start") class Start(val media: CallMediaType, val aesKey: String? = null, val iceServers: List<RTCIceServer>? = null, val relay: Boolean? = null): WCallCommand()
+  @Serializable @SerialName("start") data class Start(val media: CallMediaType, val aesKey: String? = null, val iceServers: List<RTCIceServer>? = null, val relay: Boolean? = null): WCallCommand()
-  @Serializable @SerialName("offer") class Offer(val offer: String, val iceCandidates: String, val media: CallMediaType, val aesKey: String? = null, val iceServers: List<RTCIceServer>? = null, val relay: Boolean? = null): WCallCommand()
+  @Serializable @SerialName("offer") data class Offer(val offer: String, val iceCandidates: String, val media: CallMediaType, val aesKey: String? = null, val iceServers: List<RTCIceServer>? = null, val relay: Boolean? = null): WCallCommand()
-  @Serializable @SerialName("answer") class Answer (val answer: String, val iceCandidates: String): WCallCommand()
+  @Serializable @SerialName("answer") data class Answer (val answer: String, val iceCandidates: String): WCallCommand()
-  @Serializable @SerialName("ice") class Ice(val iceCandidates: String): WCallCommand()
+  @Serializable @SerialName("ice") data class Ice(val iceCandidates: String): WCallCommand()
-  @Serializable @SerialName("media") class Media(val media: CallMediaType, val enable: Boolean): WCallCommand()
+  @Serializable @SerialName("media") data class Media(val media: CallMediaType, val enable: Boolean): WCallCommand()
-  @Serializable @SerialName("camera") class Camera(val camera: VideoCamera): WCallCommand()
+  @Serializable @SerialName("camera") data class Camera(val camera: VideoCamera): WCallCommand()
   @Serializable @SerialName("end") object End: WCallCommand()
 }
 
 @Serializable
 sealed class WCallResponse {
-  @Serializable @SerialName("capabilities") class Capabilities(val capabilities: CallCapabilities): WCallResponse()
+  @Serializable @SerialName("capabilities") data class Capabilities(val capabilities: CallCapabilities): WCallResponse()
-  @Serializable @SerialName("offer") class Offer(val offer: String, val iceCandidates: String, val capabilities: CallCapabilities): WCallResponse()
+  @Serializable @SerialName("offer") data class Offer(val offer: String, val iceCandidates: String, val capabilities: CallCapabilities): WCallResponse()
-  @Serializable @SerialName("answer") class Answer(val answer: String, val iceCandidates: String): WCallResponse()
+  @Serializable @SerialName("answer") data class Answer(val answer: String, val iceCandidates: String): WCallResponse()
-  @Serializable @SerialName("ice") class Ice(val iceCandidates: String): WCallResponse()
+  @Serializable @SerialName("ice") data class Ice(val iceCandidates: String): WCallResponse()
-  @Serializable @SerialName("connection") class Connection(val state: ConnectionState): WCallResponse()
+  @Serializable @SerialName("connection") data class Connection(val state: ConnectionState): WCallResponse()
-  @Serializable @SerialName("connected") class Connected(val connectionInfo: ConnectionInfo): WCallResponse()
+  @Serializable @SerialName("connected") data class Connected(val connectionInfo: ConnectionInfo): WCallResponse()
   @Serializable @SerialName("ended") object Ended: WCallResponse()
   @Serializable @SerialName("ok") object Ok: WCallResponse()
-  @Serializable @SerialName("error") class Error(val message: String): WCallResponse()
+  @Serializable @SerialName("error") data class Error(val message: String): WCallResponse()
 }
 
-@Serializable class WebRTCCallOffer(val callType: CallType, val rtcSession: WebRTCSession)
+@Serializable data class WebRTCCallOffer(val callType: CallType, val rtcSession: WebRTCSession)
-@Serializable class WebRTCSession(val rtcSession: String, val rtcIceCandidates: String)
+@Serializable data class WebRTCSession(val rtcSession: String, val rtcIceCandidates: String)
-@Serializable class WebRTCExtraInfo(val rtcIceCandidates: String)
+@Serializable data class WebRTCExtraInfo(val rtcIceCandidates: String)
-@Serializable class CallType(val media: CallMediaType, val capabilities: CallCapabilities)
+@Serializable data class CallType(val media: CallMediaType, val capabilities: CallCapabilities)
-@Serializable class RcvCallInvitation(val user: User, val contact: Contact, val callType: CallType, val sharedKey: String? = null, val callTs: Instant) {
+@Serializable data class RcvCallInvitation(val user: User, val contact: Contact, val callType: CallType, val sharedKey: String? = null, val callTs: Instant) {
   val callTypeText: String get() = generalGetString(when(callType.media) {
     CallMediaType.Video -> if (sharedKey == null) R.string.video_call_no_encryption else R.string.encrypted_video_call
     CallMediaType.Audio -> if (sharedKey == null) R.string.audio_call_no_encryption else R.string.encrypted_audio_call
@@ -104,8 +104,8 @@ sealed class WCallResponse {
     CallMediaType.Audio -> R.string.incoming_audio_call
   })
 }
-@Serializable class CallCapabilities(val encryption: Boolean)
+@Serializable data class CallCapabilities(val encryption: Boolean)
-@Serializable class ConnectionInfo(private val localCandidate: RTCIceCandidate?, private val remoteCandidate: RTCIceCandidate?) {
+@Serializable data class ConnectionInfo(private val localCandidate: RTCIceCandidate?, private val remoteCandidate: RTCIceCandidate?) {
   val text: String @Composable get() = when {
     localCandidate?.candidateType == RTCIceCandidateType.Host && remoteCandidate?.candidateType == RTCIceCandidateType.Host ->
       stringResource(R.string.call_connection_peer_to_peer)
@@ -116,7 +116,7 @@ sealed class WCallResponse {
   }
 }
 // https://developer.mozilla.org/en-US/docs/Web/API/RTCIceCandidate
-@Serializable class RTCIceCandidate(val candidateType: RTCIceCandidateType?)
+@Serializable data class RTCIceCandidate(val candidateType: RTCIceCandidateType?)
 // https://developer.mozilla.org/en-US/docs/Web/API/RTCIceServer
 @Serializable data class RTCIceServer(val urls: List<String>, val username: String? = null, val credential: String? = null)
 
@@ -151,7 +151,7 @@ enum class VideoCamera {
 }
 
 @Serializable
-class ConnectionState(
+data class ConnectionState(
   val connectionState: String,
   val iceConnectionState: String,
   val iceGatheringState: String,

packages/simplex-chat-webrtc/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@simplex-chat/webrtc",
-  "version": "0.1.1",
+  "version": "0.2.1",
   "description": "WebRTC call in browser and webview for SimpleX Chat clients",
   "main": "dist/call.js",
   "types": "dist/call.d.ts",

packages/simplex-chat-webrtc/src/call.ts

@@ -191,6 +191,7 @@ interface Call {
 }
 
 let activeCall: Call | undefined
+let answerTimeout = 30_000
 
 const processCommand = (function () {
   type RTCRtpSenderWithEncryption = RTCRtpSender & {
@@ -294,10 +295,17 @@ const processCommand = (function () {
     const iceCandidates = getIceCandidates(pc, config)
     const call = {connection: pc, iceCandidates, localMedia: mediaType, localCamera, localStream, remoteStream, aesKey, useWorker}
     await setupMediaStreams(call)
+    let connectionTimeout: number | undefined = setTimeout(connectionHandler, answerTimeout)
     pc.addEventListener("connectionstatechange", connectionStateChange)
     return call
 
     async function connectionStateChange() {
+      // "failed" means the second party did not answer in time (15 sec timeout in Chrome WebView)
+      // See https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/p2p/base/p2p_constants.cc;l=70)
+      if (pc.connectionState !== "failed") connectionHandler()
+    }
+
+    async function connectionHandler() {
       sendMessageToNative({
         resp: {
           type: "connection",
@@ -310,12 +318,14 @@ const processCommand = (function () {
         },
       })
       if (pc.connectionState == "disconnected" || pc.connectionState == "failed") {
+        clearConnectionTimeout()
         pc.removeEventListener("connectionstatechange", connectionStateChange)
         if (activeCall) {
           setTimeout(() => sendMessageToNative({resp: {type: "ended"}}), 0)
         }
         endCall()
       } else if (pc.connectionState == "connected") {
+        clearConnectionTimeout()
         const stats = (await pc.getStats()) as Map<string, any>
         for (const stat of stats.values()) {
           const {type, state} = stat
@@ -335,6 +345,13 @@ const processCommand = (function () {
         }
       }
     }
+
+    function clearConnectionTimeout() {
+      if (connectionTimeout) {
+        clearTimeout(connectionTimeout)
+        connectionTimeout = undefined
+      }
+    }
   }
 
   function serialize<T>(x: T): string {