/// <summary>
/// Reads the server's control stream.
/// </summary>
private async Task ProcessServerControlStreamAsync(QuicStream stream, ArrayBuffer buffer)
{
(Http3FrameType? frameType, long payloadLength) = await ReadFrameEnvelopeAsync().ConfigureAwait(false);
if (frameType == null)
{
// Connection closed prematurely, expected SETTINGS frame.
throw new Http3ConnectionException(Http3ErrorCode.ClosedCriticalStream);
}
if (frameType != Http3FrameType.Settings)
{
// Expected SETTINGS as first frame of control stream.
throw new Http3ConnectionException(Http3ErrorCode.MissingSettings);
}
await ProcessSettingsFrameAsync(payloadLength).ConfigureAwait(false);
while (true)
{
(frameType, payloadLength) = await ReadFrameEnvelopeAsync().ConfigureAwait(false);
switch (frameType)
{
case Http3FrameType.GoAway:
await ProcessGoAwayFameAsync(payloadLength).ConfigureAwait(false);
break;
case Http3FrameType.Settings:
// Only a single SETTINGS frame is supported.
throw new Http3ConnectionException(Http3ErrorCode.UnexpectedFrame);
case Http3FrameType.Headers:
case Http3FrameType.Data:
case Http3FrameType.MaxPushId:
case Http3FrameType.DuplicatePush:
// Servers should not send these frames to a control stream.
throw new Http3ConnectionException(Http3ErrorCode.UnexpectedFrame);
case Http3FrameType.PushPromise:
case Http3FrameType.CancelPush:
// Because we haven't sent any MAX_PUSH_ID frame, it is invalid to receive any push-related frames as they will all reference a too-large ID.
throw new Http3ConnectionException(Http3ErrorCode.IdError);
case null:
// End of stream reached. If we're shutting down, stop looping. Otherwise, this is an error (this stream should not be closed for life of connection).
bool shuttingDown;
lock (SyncObj)
{
shuttingDown = ShuttingDown;
}
if (!shuttingDown)
{
throw new Http3ConnectionException(Http3ErrorCode.ClosedCriticalStream);
}
return;
default:
await SkipUnknownPayloadAsync(frameType.GetValueOrDefault(), payloadLength).ConfigureAwait(false);
break;
}
}
async ValueTask <(Http3FrameType?frameType, long payloadLength)> ReadFrameEnvelopeAsync()
{
long frameType, payloadLength;
int bytesRead;
while (!Http3Frame.TryReadIntegerPair(buffer.ActiveSpan, out frameType, out payloadLength, out bytesRead))
{
buffer.EnsureAvailableSpace(VariableLengthIntegerHelper.MaximumEncodedLength * 2);
bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else if (buffer.ActiveLength == 0)
{
// End of stream.
return(null, 0);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
buffer.Discard(bytesRead);
return((Http3FrameType)frameType, payloadLength);
}
async ValueTask ProcessSettingsFrameAsync(long settingsPayloadLength)
{
if (settingsPayloadLength > MaximumSettingsPayloadLength)
{
if (NetEventSource.Log.IsEnabled())
{
Trace($"Received SETTINGS frame with {settingsPayloadLength} byte payload exceeding the {MaximumSettingsPayloadLength} byte maximum.");
}
throw new Http3ConnectionException(Http3ErrorCode.ExcessiveLoad);
}
while (settingsPayloadLength != 0)
{
long settingId, settingValue;
int bytesRead;
while (!Http3Frame.TryReadIntegerPair(buffer.ActiveSpan, out settingId, out settingValue, out bytesRead))
{
buffer.EnsureAvailableSpace(VariableLengthIntegerHelper.MaximumEncodedLength * 2);
bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
settingsPayloadLength -= bytesRead;
// Only support this single setting. Skip others.
if (settingId == (long)Http3SettingType.MaxHeaderListSize)
{
_maximumHeadersLength = (int)Math.Min(settingValue, int.MaxValue);
}
}
}
async ValueTask ProcessGoAwayFameAsync(long goawayPayloadLength)
{
long lastStreamId;
int bytesRead;
while (!VariableLengthIntegerHelper.TryRead(buffer.AvailableSpan, out lastStreamId, out bytesRead))
{
buffer.EnsureAvailableSpace(VariableLengthIntegerHelper.MaximumEncodedLength);
bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
buffer.Discard(bytesRead);
if (bytesRead != goawayPayloadLength)
{
// Frame contains unknown extra data after the integer.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
OnServerGoAway(lastStreamId);
}
async ValueTask SkipUnknownPayloadAsync(Http3FrameType frameType, long payloadLength)
{
if (payloadLength > MaximumUnknownFramePayloadLength)
{
Trace($"Received unknown frame type 0x{(long)frameType:x} with {payloadLength} byte payload exceeding the {MaximumUnknownFramePayloadLength} byte maximum.");
throw new Http3ConnectionException(Http3ErrorCode.ExcessiveLoad);
}
while (payloadLength != 0)
{
if (buffer.ActiveLength == 0)
{
int bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
long readLength = Math.Min(payloadLength, buffer.ActiveLength);
buffer.Discard((int)readLength);
payloadLength -= readLength;
}
}
}
/// <summary>
/// Reads the server's control stream.
/// </summary>
private async Task ProcessServerControlStreamAsync(QuicStream stream, ArrayBuffer buffer)
{
using (buffer)
{
// Read the first frame of the control stream. Per spec:
// A SETTINGS frame MUST be sent as the first frame of each control stream.
(Http3FrameType? frameType, long payloadLength) = await ReadFrameEnvelopeAsync().ConfigureAwait(false);
if (frameType == null)
{
// Connection closed prematurely, expected SETTINGS frame.
throw new Http3ConnectionException(Http3ErrorCode.ClosedCriticalStream);
}
if (frameType != Http3FrameType.Settings)
{
throw new Http3ConnectionException(Http3ErrorCode.MissingSettings);
}
await ProcessSettingsFrameAsync(payloadLength).ConfigureAwait(false);
// Read subsequent frames.
while (true)
{
(frameType, payloadLength) = await ReadFrameEnvelopeAsync().ConfigureAwait(false);
switch (frameType)
{
case Http3FrameType.GoAway:
await ProcessGoAwayFameAsync(payloadLength).ConfigureAwait(false);
break;
case Http3FrameType.Settings:
// If an endpoint receives a second SETTINGS frame on the control stream, the endpoint MUST respond with a connection error of type H3_FRAME_UNEXPECTED.
throw new Http3ConnectionException(Http3ErrorCode.UnexpectedFrame);
case Http3FrameType.Headers:
case Http3FrameType.Data:
case Http3FrameType.MaxPushId:
case Http3FrameType.DuplicatePush:
// Servers should not send these frames to a control stream.
throw new Http3ConnectionException(Http3ErrorCode.UnexpectedFrame);
case Http3FrameType.PushPromise:
case Http3FrameType.CancelPush:
// Because we haven't sent any MAX_PUSH_ID frame, it is invalid to receive any push-related frames as they will all reference a too-large ID.
throw new Http3ConnectionException(Http3ErrorCode.IdError);
case null:
// End of stream reached. If we're shutting down, stop looping. Otherwise, this is an error (this stream should not be closed for life of connection).
bool shuttingDown;
lock (SyncObj)
{
shuttingDown = ShuttingDown;
}
if (!shuttingDown)
{
throw new Http3ConnectionException(Http3ErrorCode.ClosedCriticalStream);
}
return;
default:
await SkipUnknownPayloadAsync(frameType.GetValueOrDefault(), payloadLength).ConfigureAwait(false);
break;
}
}
}
async ValueTask <(Http3FrameType?frameType, long payloadLength)> ReadFrameEnvelopeAsync()
{
long frameType, payloadLength;
int bytesRead;
while (!Http3Frame.TryReadIntegerPair(buffer.ActiveSpan, out frameType, out payloadLength, out bytesRead))
{
buffer.EnsureAvailableSpace(VariableLengthIntegerHelper.MaximumEncodedLength * 2);
bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else if (buffer.ActiveLength == 0)
{
// End of stream.
return(null, 0);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
buffer.Discard(bytesRead);
return((Http3FrameType)frameType, payloadLength);
}
async ValueTask ProcessSettingsFrameAsync(long settingsPayloadLength)
{
while (settingsPayloadLength != 0)
{
long settingId, settingValue;
int bytesRead;
while (!Http3Frame.TryReadIntegerPair(buffer.ActiveSpan, out settingId, out settingValue, out bytesRead))
{
buffer.EnsureAvailableSpace(VariableLengthIntegerHelper.MaximumEncodedLength * 2);
bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
settingsPayloadLength -= bytesRead;
if (settingsPayloadLength < 0)
{
// An integer was encoded past the payload length.
// A frame payload that contains additional bytes after the identified fields or a frame payload that terminates before the end of the identified fields MUST be treated as a connection error of type H3_FRAME_ERROR.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
buffer.Discard(bytesRead);
// Only support this single setting. Skip others.
if (settingId == (long)Http3SettingType.MaxHeaderListSize)
{
_maximumHeadersLength = (int)Math.Min(settingValue, int.MaxValue);
}
}
}
async ValueTask ProcessGoAwayFameAsync(long goawayPayloadLength)
{
long lastStreamId;
int bytesRead;
while (!VariableLengthIntegerHelper.TryRead(buffer.AvailableSpan, out lastStreamId, out bytesRead))
{
buffer.EnsureAvailableSpace(VariableLengthIntegerHelper.MaximumEncodedLength);
bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
buffer.Discard(bytesRead);
if (bytesRead != goawayPayloadLength)
{
// Frame contains unknown extra data after the integer.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
OnServerGoAway(lastStreamId);
}
async ValueTask SkipUnknownPayloadAsync(Http3FrameType frameType, long payloadLength)
{
while (payloadLength != 0)
{
if (buffer.ActiveLength == 0)
{
int bytesRead = await stream.ReadAsync(buffer.AvailableMemory, CancellationToken.None).ConfigureAwait(false);
if (bytesRead != 0)
{
buffer.Commit(bytesRead);
}
else
{
// Our buffer has partial frame data in it but not enough to complete the read: bail out.
throw new Http3ConnectionException(Http3ErrorCode.FrameError);
}
}
long readLength = Math.Min(payloadLength, buffer.ActiveLength);
buffer.Discard((int)readLength);
payloadLength -= readLength;
}
}
}
