GRPC Data Unmarshalling Error

[aliumujib]

Describe the bug

We're using Livekit in our Android app, calling works well and we're able to create and join rooms. However trying to use the room.localParticipant.publishData mechanism doesn't work. When trying to send the data from the client, it throws the following error which crashes our app:

We also tried moving the publishData call to our backend server, but the app still crashes when the SDK tries to deserialize data received, so RoomEvent.DataReceived is never triggered.

To Reproduce Steps to reproduce the behavior:

1. Connect to a call with mutliple devices

2. Try to send some data through the room.localParticipant.publishData function. In our case, we're trying to publish a small JSON payload that has been serialized to bytes.

   {
   "type": "com.reachout.android.calls.ui.base.CallEventSignal.RequestToSpeak",
   "requesterId": "NTuScSP1S9K8hRS45EhqgQ=="
   }

3. The app crashes with the exception in the screenshot above.

Expected behavior The data should be broadcast to all the participants in the room and be available for deserialization via the RoomEvent.DataReceived event.

Device Info:

• Device: Samsung Flip 3, Nothing Phone 1
• OS: Android 12.
• LiveKit SDK version: 2.1.1

Additional context We use GRPC for all network calls in all the app, the we use the following library versions:

versions.grpc = "1.62.2"

def grpc = [:]
grpc.grpc_okhttp = "$groups.grpc:grpc-okhttp:$versions.grpc"
grpc.grpc_stub = "$groups.grpc:grpc-stub:$versions.grpc"
grpc.grpc_protobuff_lite = "$groups.grpc:grpc-protobuf-lite:1.62.2"
grpc.grpc_kotlin_stub = "$groups.grpc:grpc-kotlin-stub:1.4.1"
grpc.grpc_protobuff_kt_lite = "com.google.protobuf:protobuf-kotlin-lite:4.26.0"
deps.grpc = grpc

Protobuff setup:

protobuf {
    protoc {
        if (project.hasProperty('protoc_platform')) {
            artifact = "com.google.protobuf:protoc:21.0-rc-1:${protoc_platform}"
        } else {
            artifact = "com.google.protobuf:protoc:21.0-rc-1"
        }
    }
    plugins {
        grpc {
            artifact = 'io.grpc:protoc-gen-grpc-java:1.62.2' // CURRENT_GRPC_VERSION
        }
        grpckt {
            artifact = "io.grpc:protoc-gen-grpc-kotlin:1.4.1:jdk8@jar"
        }
    }
    generateProtoTasks {
        all().each { task ->
            task.builtins {
                kotlin { option 'lite' }
                java { option 'lite' }
            }
            task.plugins {
                grpc { // Options added to --grpc_out
                    option 'lite'
                }
                grpckt { // Options added to --grpc_out
                    option 'lite'
                }
            }
        }
    }
}

[davidliu]

The error in the screenshot looks like that's when you receive a message from the server. Do you also have one from when you send? Also text error logs would be appreciated instead of screenshots.

[aliumujib]

Thanks for your response @davidliu It is exactly the same error both ways. Please see the logs below:

java.lang.StringIndexOutOfBoundsException: length=23; index=23
    at java.lang.String.charAt(Native Method)
    at com.google.protobuf.MessageSchema.newSchemaForRawMessageInfo(MessageSchema.java:427)
    at com.google.protobuf.MessageSchema.newSchema(MessageSchema.java:221)
    at com.google.protobuf.ManifestSchemaFactory.newSchema(ManifestSchemaFactory.java:85)
    at com.google.protobuf.ManifestSchemaFactory.createSchema(ManifestSchemaFactory.java:71)
    at com.google.protobuf.Protobuf.schemaFor(Protobuf.java:93)
    at com.google.protobuf.MessageSchema.getMessageFieldSchema(MessageSchema.java:4849)
    at com.google.protobuf.MessageSchema.mergeFromHelper(MessageSchema.java:4241)
    at com.google.protobuf.MessageSchema.mergeFrom(MessageSchema.java:3846)
    at com.google.protobuf.GeneratedMessageLite.parsePartialFrom(GeneratedMessageLite.java:1531)
    at com.google.protobuf.GeneratedMessageLite.parsePartialFrom(GeneratedMessageLite.java:1630)
    at com.google.protobuf.GeneratedMessageLite.parseFrom(GeneratedMessageLite.java:1619)
    at com.google.protobuf.GeneratedMessageLite.parseFrom(GeneratedMessageLite.java:1612)
    at livekit.LivekitModels$DataPacket.parseFrom(LivekitModels.java:9997)
    at io.livekit.android.room.RTCEngine.onMessage(RTCEngine.kt:941)
    at io.livekit.android.room.RTCEngine$DataChannelObserver.onMessage(RTCEngine.kt:969)
#
# Fatal error in: gen/jni_headers/sdk/android/generated_metrics_jni/../../../../../../../../../../../_source/android_prefixed/webrtc/src/sdk/android/src/jni/jni_generator_helper.h, line 95
# last system error: 0
# Check failed: !env->ExceptionCheck()
# 
Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 10647 (signaling_threa), pid 10366 (eachout.android)
Cmdline: chat.reachout.android
pid: 10366, tid: 10647, name: signaling_threa  >>> chat.reachout.android <<<
    #01 pc 000000000042086c  /data/app/~~vTCHnI0ckZx6db5dck92ZA==/chat.reachout.android-BrdnGAC1KTvzZx8YzUU5Gg==/base.apk!libjingle_peerconnection_so.so (offset 0x652e000) (BuildId: 70ca83c0b27c0940)
    #02 pc 0000000000420eb0  /data/app/~~vTCHnI0ckZx6db5dck92ZA==/chat.reachout.android-BrdnGAC1KTvzZx8YzUU5Gg==/base.apk!libjingle_peerconnection_so.so (offset 0x652e000) (BuildId: 70ca83c0b27c0940)
    #03 pc 000000000041019c  /data/app/~~vTCHnI0ckZx6db5dck92ZA==/chat.reachout.android-BrdnGAC1KTvzZx8YzUU5Gg==/base.apk!libjingle_peerconnection_so.so (offset 0x652e000) (BuildId: 70ca83c0b27c0940)
    #04 pc 00000000004100ac  /data/app/~~vTCHnI0ckZx6db5dck92ZA==/chat.reachout.android-BrdnGAC1KTvzZx8YzUU5Gg==/base.apk!libjingle_peerconnection_so.so (offset 0x652e000) (BuildId: 70ca83c0b27c0940)
    #05 pc 00000000008117e4  /data/app/~~vTCHnI0ckZx6db5dck92ZA==/chat.reachout.android-BrdnGAC1KTvzZx8YzUU5Gg==/base.apk!libjingle_peerconnection_so.so (offset 0x652e000) (BuildId: 70ca83c0b27c0940)
    #06 pc 000000000043e014  /data/app/~~vTCHnI0ckZx6db5dck92ZA==/chat.reachout.android-BrdnGAC1KTvzZx8YzUU5Gg==/base.apk!libjingle_peerconnection_so.so (offset 0x652e000) (BuildId: 70ca83c0b27c0940)
    #07 pc 000000000043d454  /data/app/~~v

[aliumujib]

Also we suspect that the error is due to the optional field in this message (we're using GRPC kotlin). I can't find usages of optional fields anywhere else in the models.proto file which might explain why other pieces of functionality works.

[aliumujib]

@davidliu following up.

[davidliu]

Hey, sorry for the delay.

I wonder if it's a compatibility issue here? We're on 3.22.0, and you're using 4.26.0 here. A bump in major version might be the cause here.

GRPC itself seems to not have upgraded to 4.26 either, as noted in https://github.com/grpc/grpc-java/issues/11015

Can you try downgrading to 3.22 (or 3.25.1, which is what grpc uses)?