CODEWITHSUNDEEP
c#.netwebsocketreal-timeclientwebsocket
ggeorge
ggeorge

Reputation: 1630

Receiving messages using ClientWebSocket Class throws exception: The WebSocket received a frame with one or more reserved bits set

I 'd like to make a websocket client to connect to a third-party web socket server.

I am using ClientWebSocket Class:

public WSClientService(ClientWebSocket client, ILogger<WSClientService> logger)
{
    _client = client;
    _logger = logger;
}

For receiving messages i use this method:

public async Task GetMessagesAsync()
{
    while (_client.State == WebSocketState.Open)
    {
        var chunkSize = 1024 * 4;
        var buffer = new ArraySegment<byte>(new byte[chunkSize]);

        do
        {
            WebSocketReceiveResult result;
            using var ms = new MemoryStream();
            try
            {
                do
                {
                    //here throws exception
                    result = await _client.ReceiveAsync(buffer, CancellationToken.None);
                    ms.Write(buffer.Array, buffer.Offset, result.Count);
                } while (!result.EndOfMessage);

                if (result.MessageType == WebSocketMessageType.Close)
                {
                    break;
                }

                ms.Seek(0, SeekOrigin.Begin);
                using var reader = new StreamReader(ms, Encoding.UTF8);
                var message = await reader.ReadToEndAsync();
                _logger.LogInformation(message);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.Message);
            }

        } while (_client.State != WebSocketState.Aborted);                
    }
}

But for some messages i get this exception message : The WebSocket received a frame with one or more reserved bits set I noticed that this occurs probably by some compression because i can receive small messages. The exception thrown when calling this result = await _client.ReceiveAsync(buffer, CancellationToken.None);

Does anybody knows how to solve this problem?

Upvotes: 0

Views: 1343

Answers (1)

ggeorge
ggeorge

Reputation: 1630

The solution came with .net 6 release. Well the problem occured because there was no way to add compression in built-in ClientWebSocket in .net 5 and back (Except if someone would create an extension method for compression). Now with .net 6 there is a new option named DangerousDeflateOptions. This adds the corresponding header as well.

_ws.Options.DangerousDeflateOptions = new WebSocketDeflateOptions
{
    ServerContextTakeover = false,
    ClientMaxWindowBits = 15 // this is the default value
};

await _ws.ConnectAsync(new Uri(_url), token).ConfigureAwait(false);

Upvotes: 0

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