public static bool TryParse(ReadableBuffer payload, out WebSocketCloseResult result, out ushort?actualCloseCode)
{
if (payload.Length == 0)
{
// Empty payload is OK
actualCloseCode = null;
result = new WebSocketCloseResult(WebSocketCloseStatus.Empty, string.Empty);
return(true);
}
else if (payload.Length < 2)
{
actualCloseCode = null;
result = default(WebSocketCloseResult);
return(false);
}
else
{
var status = payload.ReadBigEndian <ushort>();
actualCloseCode = status;
var description = string.Empty;
payload = payload.Slice(2);
if (payload.Length > 0)
{
description = payload.GetUtf8String();
}
result = new WebSocketCloseResult((WebSocketCloseStatus)status, description);
return(true);
}
}
private async Task <WebSocketCloseResult> CloseFromProtocolError(CancellationToken cancellationToken, int payloadLen, ReadableBuffer payload, string reason, WebSocketCloseStatus statusCode = WebSocketCloseStatus.ProtocolError)
{
// Non-continuation non-control message during fragmented message
if (payloadLen > 0)
{
_inbound.Advance(payload.End);
}
var closeResult = new WebSocketCloseResult(
statusCode,
reason);
await CloseAsync(closeResult, cancellationToken);
Dispose();
return(closeResult);
}
private WebSocketCloseResult HandleCloseFrame(ReadableBuffer payload, WebSocketFrame frame, out ushort?actualStatusCode)
{
// Update state
if (State == WebSocketConnectionState.CloseSent)
{
State = WebSocketConnectionState.Closed;
}
else
{
State = WebSocketConnectionState.CloseReceived;
}
// Process the close frame
WebSocketCloseResult closeResult;
if (!WebSocketCloseResult.TryParse(frame.Payload, out closeResult, out actualStatusCode))
{
closeResult = WebSocketCloseResult.Empty;
}
return(closeResult);
}
/// <summary>
/// Sends a Close frame to the other party. This does not guarantee that the client will send a responding close frame.
/// </summary>
/// <remarks>
/// If the other party does not respond with a close frame, the connection will remain open and the <see cref="Task{WebSocketCloseResult}"/>
/// will remain active. Call the <see cref="IDisposable.Dispose"/> method on this instance to forcibly terminate the connection.
/// </remarks>
/// <param name="result">A <see cref="WebSocketCloseResult"/> with the payload for the close frame</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> that indicates when/if the send is cancelled.</param>
/// <returns>A <see cref="Task"/> that completes when the close frame has been sent</returns>
public async Task CloseAsync(WebSocketCloseResult result, CancellationToken cancellationToken)
{
if (State == WebSocketConnectionState.Closed)
{
throw new ObjectDisposedException(nameof(WebSocketConnection));
}
else if (State == WebSocketConnectionState.Created)
{
throw new InvalidOperationException("Cannot send close frame when the connection hasn't been started");
}
else if (State == WebSocketConnectionState.CloseSent)
{
throw new InvalidOperationException("Cannot send multiple close frames");
}
var payloadSize = result.GetSize();
await SendCoreAsync(
fin : true,
opcode : WebSocketOpcode.Close,
payloadAllocLength : payloadSize,
payloadLength : payloadSize,
payloadWriter : CloseResultPayloadWriter,
payload : result,
cancellationToken : cancellationToken);
_timerCts.Cancel();
_pinger?.Dispose();
if (State == WebSocketConnectionState.CloseReceived)
{
State = WebSocketConnectionState.Closed;
}
else
{
State = WebSocketConnectionState.CloseSent;
}
}
private static void CloseResultPayloadWriter(WritableBuffer output, Span <byte> maskingKey, int payloadLength, WebSocketCloseResult result)
{
// Write the close payload out
var payload = output.Memory.Slice(0, payloadLength).Span;
result.WriteTo(ref output);
if (maskingKey.Length > 0)
{
MaskingUtilities.ApplyMask(payload, maskingKey);
}
}
/// <summary> /// Sends a Close frame to the other party. This does not guarantee that the client will send a responding close frame. /// </summary> /// <param name="result">A <see cref="WebSocketCloseResult"/> with the payload for the close frame.</param> /// <returns>A <see cref="Task"/> that completes when the close frame has been sent</returns> public static Task CloseAsync(this IWebSocketConnection self, WebSocketCloseResult result) => self.CloseAsync(result, CancellationToken.None);
