How can i connect to Stun/Turn servers from Ue4

Development Programming & Scripting C++
1

I have noticed that ue4 with pixel streaming uses webrtc .
i was wondering how can i use ue4 webrtc implementation for contacting a Stun/turn server and get my info so i can establish a peer to peer connection?

2

i tried to implement a stun client.



void UMyGameInstance::StunClientConnection()
{            

    ISocketSubsystem* SocketSubsystem = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM);
    //Set Send Buffer Size
    int32 BufferSize = 2 * 1024 * 1024;


     //////////prepare the listener
     ///


         FIPv4Address Addr;
         FIPv4Address::Parse(TEXT("0.0.0.0"), Addr);

         //Create Socket
         FIPv4Endpoint Endpoint(Addr, 3002);

          ListenSocket = FUdpSocketBuilder(TEXT("Udpsocket"))
             .AsReusable()
             .AsNonBlocking()
             .BoundToEndpoint(Endpoint)
             .WithBroadcast()
             .WithReceiveBufferSize(BufferSize)
             ;


         if (ListenSocket == nullptr)
         {
             UE_LOG(LogTemp, Error, TEXT("ListenSocket==nullptr "));
             return;
         }

         FTimespan ThreadWaitTime = FTimespan::FromMilliseconds(100);


         UDPReceiver = new FUdpSocketReceiver(ListenSocket, ThreadWaitTime, TEXT("thread_udp_receiver"));
         UDPReceiver->OnDataReceived().BindUObject(this, &UMyGameInstance::OnDataReceivedDelegate);
         UDPReceiver->Start(); 

    ////prepare the package to send

    FSocket* socketd = FUdpSocketBuilder(TEXT("Udpsocket")).AsReusable().WithBroadcast();

    TSharedRef<FInternetAddr> RemoteAddr = SocketSubsystem->CreateInternetAddr();
    bool bTestLocal = false;

    if(bTestLocal==false)
    {
        FAddressInfoResult GAIResults = SocketSubsystem->GetAddressInfo(ANSI_TO_TCHAR("stun.l.google.com"), nullptr, EAddressInfoFlags::Default, NAME_None);

        ESocketErrors ErrorCode = GAIResults.ReturnCode;
        if (ErrorCode != SE_NO_ERROR)
        {
            switch (ErrorCode)
            {
            case ESocketErrors::SE_HOST_NOT_FOUND:UE_LOG(LogTemp, Error, TEXT("ErrorCode --> SE_HOST_NOT_FOUND ")); break;
            case ESocketErrors::SE_NO_DATA:UE_LOG(LogTemp, Error, TEXT("ErrorCode --> SE_NO_DATA ")); break;
            case ESocketErrors::SE_ETIMEDOUT:UE_LOG(LogTemp, Error, TEXT("ErrorCode --> SE_ETIMEDOUT ")); break;

            }
            UE_LOG(LogTemp, Error, TEXT("RemoteAddr -->  "), *RemoteAddr->ToString(true));
            return;
        }
        if ((GAIResults.Results.Num() == 0))
        {
            UE_LOG(LogTemp, Error, TEXT("GAIResults.Results.Num()==0"));

            return;
        }

        RemoteAddr = (GAIResults.Results[0].Address);
        RemoteAddr->SetPort(19302);
    }else
    {
        bool bValidAddress;

        RemoteAddr->SetIp(TEXT("192.168.0.13"), bValidAddress);
        RemoteAddr->SetPort(3000);

        UE_LOG(LogTemp, Warning, TEXT("bValidAddress %s"), (bValidAddress ? TEXT("True") : TEXT("False")));

    } 
    socketd->SetSendBufferSize(BufferSize, BufferSize);
    socketd->SetReceiveBufferSize(BufferSize, BufferSize); 


    unsigned char bindingReq[20];
    //## first bind 
    *(short*)(&bindingReq[0]) = int16(0x0001);    // stun_method
    *(short*)(&bindingReq[2]) = int16(0x0000);    // msg_length
    *(int*)(&bindingReq[4]) = int32(0x2112A442);// magic cookie

    *(int*)(&bindingReq[8]) = int32(0x63c7117e);   // transacation ID 
    *(int*)(&bindingReq[12]) = int32(0x0714278f);
    *(int*)(&bindingReq[16]) = int32(0x5ded3221);


    int32 BytesSent = 0;  


    socketd->SendTo(bindingReq,sizeof(bindingReq)  , BytesSent ,*RemoteAddr);
    if (BytesSent <= 0)
    {
        const FString Str = "Socket is valid but the receiver received 0 bytes, make sure it is listening properly!";
        UE_LOG(LogTemp, Error, TEXT("%s"), *Str);

        return  ;
    }else
        UE_LOG(LogTemp, Warning, TEXT("Package Sent to %s  with   %d BytesSent"), *RemoteAddr->ToString(true),BytesSent);

}


void UMyGameInstance::OnDataReceivedDelegate(const FArrayReaderPtr& DataPtr, const FIPv4Endpoint& Endpoint)
{
    UE_LOG(LogTemp, Error, TEXT("OnDataReceivedDelegate..."));
    TArray<uint8> Data;
    Data.AddUninitialized(DataPtr->TotalSize());
    DataPtr->Serialize(Data.GetData(), DataPtr->TotalSize());
    UE_LOG(LogTemp, Error, TEXT("OnDataReceivedDelegate..."));
}

when i call it the ue4 log shows

LogTemp: Warning: USMainMenuWidget::OnHostMatchPressed()
LogTemp: Warning: Package Sent to 64.233.186.127:19302  with   20 BytesSent

using wireshark i can see that the packet is send and recived, but the stun server doesnt respond.
if i do the same using nodejs i get the response from the Stun server so i wonder, maybe there is a problem with the packet sent?

3

Did you figure it out?

4

I finally abandon the project