public async Task WriteAsync(ArraySegment <byte> buffer, bool endOfStream = false)
{
var removeStream = false;
await writeMutex.WaitAsync();
try
{
lock (stateMutex)
{
// Check the current stream state
if (state == StreamState.Reset)
{
throw new StreamResetException();
}
else if (state != StreamState.Open && state != StreamState.HalfClosedRemote)
{
throw new Exception("Attempt to write data in invalid stream state");
}
else if (state == StreamState.Open && endOfStream)
{
state = StreamState.HalfClosedLocal;
}
else if (state == StreamState.HalfClosedRemote && endOfStream)
{
state = StreamState.Closed;
removeStream = true;
}
// Besides state check also check if headers have already been sent
// StreamState.Open could mean we only have received them
if (!this.headersSent)
{
throw new Exception("Attempted to write data before headers");
}
// Remark: There's no need to check whether trailers have already
// been sent as writing trailers will (half)close the stream,
// which is checked for
dataSent = true; // Set a flag do disallow following headers
}
// Remark:
// As we hold the writeMutex nobody can close the stream or send trailers
// in between.
// The only thing that may happen is that the stream get's reset in between,
// which would be reported through the ConnectionWriter to us
var fh = new FrameHeader {
StreamId = this.Id,
Type = FrameType.Data,
Flags = endOfStream ? ((byte)DataFrameFlags.EndOfStream) : (byte)0,
};
var res = await connection.writer.WriteData(fh, buffer);
if (res == ConnectionWriter.WriteResult.StreamResetError)
{
throw new StreamResetException();
}
else if (res != ConnectionWriter.WriteResult.Success)
{
throw new Exception("Can not write to stream"); // TODO: Improve me
}
}
finally
{
writeMutex.Release();
if (removeStream)
{
connection.UnregisterStream(this);
}
}
}
/// <summary>
/// Reads and decodes a header block which consists of a single HEADER
/// frame and 0 or more CONTINUATION frames.
/// </summary>
/// <param name="firstHeader">
/// The frame header of the HEADER frame which indicates that headers
/// must be read.
/// </param>
public async ValueTask <Result> ReadHeaders(
FrameHeader firstHeader,
Func <int, byte[]> ensureBuffer)
{
// Check maximum frame size
if (firstHeader.Length > maxFrameSize)
{
return(new Result
{
Error = new Http2Error
{
StreamId = 0,
Code = ErrorCode.FrameSizeError,
Message = "Maximum frame size exceeded",
},
});
}
PriorityData?prioData = null;
var allowedHeadersSize = maxHeaderFieldsSize;
var headers = new List <HeaderField>();
var initialFlags = firstHeader.Flags;
var f = (HeadersFrameFlags)firstHeader.Flags;
var isEndOfStream = f.HasFlag(HeadersFrameFlags.EndOfStream);
var isEndOfHeaders = f.HasFlag(HeadersFrameFlags.EndOfHeaders);
var isPadded = f.HasFlag(HeadersFrameFlags.Padded);
var hasPriority = f.HasFlag(HeadersFrameFlags.Priority);
// Do a first check whether frame is big enough for the given flags
var minLength = 0;
if (isPadded)
{
minLength += 1;
}
if (hasPriority)
{
minLength += 5;
}
if (firstHeader.Length < minLength)
{
return(new Result
{
Error = new Http2Error
{
StreamId = 0,
Code = ErrorCode.ProtocolError,
Message = "Invalid frame content size",
},
});
}
// Get a buffer for the initial frame
// TODO: We now always read the initial frame at once, but we could
// split it up into multiple smaller reads if the receive buffer is
// smaller. The code needs to be slightly adapted for this.
byte[] buffer = ensureBuffer(firstHeader.Length);
// Read the content of the initial frame
await reader.ReadAll(new ArraySegment <byte>(buffer, 0, firstHeader.Length));
var offset = 0;
var padLen = 0;
if (isPadded)
{
// Extract padding Length
padLen = buffer[0];
offset++;
}
if (hasPriority)
{
// Extract priority
prioData = PriorityData.DecodeFrom(
new ArraySegment <byte>(buffer, offset, 5));
offset += 5;
}
var contentLen = firstHeader.Length - offset - padLen;
if (contentLen < 0)
{
return(new Result
{
Error = new Http2Error
{
StreamId = 0,
Code = ErrorCode.ProtocolError,
Message = "Invalid frame content size",
},
});
}
// Allow table updates at the start of header header block
// This will be reset once the first header was decoded and will
// persist also during the continuation frame
hpackDecoder.AllowTableSizeUpdates = true;
// Decode headers from the first header block
var decodeResult = hpackDecoder.DecodeHeaderBlockFragment(
new ArraySegment <byte>(buffer, offset, contentLen),
allowedHeadersSize,
headers);
var err = DecodeResultToError(decodeResult);
if (err != null)
{
return(new Result {
Error = err
});
}
allowedHeadersSize -= decodeResult.HeaderFieldsSize;
while (!isEndOfHeaders)
{
// Read the next frame header
// This must be a continuation frame
// Remark: No need for ensureBuffer, since the buffer is
// guaranteed to be larger than the first frameheader buffer
var contHeader = await FrameHeader.ReceiveAsync(reader, buffer);
if (logger != null && logger.IsEnabled(LogLevel.Trace))
{
logger.LogTrace("recv " + FramePrinter.PrintFrameHeader(contHeader));
}
if (contHeader.Type != FrameType.Continuation ||
contHeader.StreamId != firstHeader.StreamId ||
contHeader.Length > maxFrameSize ||
contHeader.Length == 0)
{
return(new Result
{
Error = new Http2Error
{
StreamId = 0,
Code = ErrorCode.ProtocolError,
Message = "Invalid continuation frame",
},
});
}
var contFlags = ((ContinuationFrameFlags)contHeader.Flags);
isEndOfHeaders = contFlags.HasFlag(ContinuationFrameFlags.EndOfHeaders);
// Read the HeaderBlockFragment of the continuation frame
// TODO: We now always read the frame at once, but we could
// split it up into multiple smaller reads if the receive buffer
// is smaller. The code needs to be slightly adapted for this.
buffer = ensureBuffer(contHeader.Length);
await reader.ReadAll(new ArraySegment <byte>(buffer, 0, contHeader.Length));
offset = 0;
contentLen = contHeader.Length;
// Decode headers from continuation fragment
decodeResult = hpackDecoder.DecodeHeaderBlockFragment(
new ArraySegment <byte>(buffer, offset, contentLen),
allowedHeadersSize,
headers);
var err2 = DecodeResultToError(decodeResult);
if (err2 != null)
{
return(new Result {
Error = err2
});
}
allowedHeadersSize -= decodeResult.HeaderFieldsSize;
}
// Check if decoder is initial state, which means a complete header
// block was received
if (!hpackDecoder.HasInitialState)
{
return(new Result
{
Error = new Http2Error
{
Code = ErrorCode.CompressionError,
StreamId = 0u,
Message = "Received incomplete header block",
},
});
}
return(new Result
{
Error = null,
HeaderData = new CompleteHeadersFrameData
{
StreamId = firstHeader.StreamId,
Headers = headers,
Priority = prioData,
EndOfStream = isEndOfStream,
},
});
}
internal ValueTask <ConnectionWriter.WriteResult> Reset(
ErrorCode errorCode, bool fromRemote)
{
ValueTask <ConnectionWriter.WriteResult> writeResetTask =
new ValueTask <ConnectionWriter.WriteResult>(
ConnectionWriter.WriteResult.Success);
lock (stateMutex)
{
if (state == StreamState.Reset || state == StreamState.Closed)
{
// Already reset or fully closed
return(writeResetTask);
}
state = StreamState.Reset;
// Free the receive queue
var head = receiveQueueHead;
receiveQueueHead = null;
FreeReceiveQueue(head);
}
if (connection.logger != null)
{
connection.logger.LogTrace(
"Resetted stream {0} with error code {1}",
Id, errorCode);
}
// Remark: Even if we are here in IDLE state we need to send the
// RESET frame. The reason for this is that if we receive a header
// for a new stream which is invalid a StreamImpl instance will be
// created and put into IDLE state. The header processing will fail
// and Reset will get called. As the remote thinks we are in Open
// state we must send a RST_STREAM.
if (!fromRemote)
{
// Send a reset frame with the given error code
var fh = new FrameHeader
{
StreamId = this.Id,
Type = FrameType.ResetStream,
Flags = 0,
};
var resetData = new ResetFrameData
{
ErrorCode = errorCode
};
writeResetTask = connection.writer.WriteResetStream(fh, resetData);
}
else
{
// If we don't send a notification we still have to unregister
// from the writer in order to cancel pending writes
connection.writer.RemoveStream(this.Id);
}
// Unregister from the connection
// If this has happened from the remote side the connection will
// already have performed this
if (!fromRemote)
{
this.connection.UnregisterStream(this);
}
// Unblock all waiters
readDataPossible.Set();
readTrailersPossible.Set();
readHeadersPossible.Set();
return(writeResetTask);
}