HTTP/3: Return H3_FRAME_UNEXPECTED protocol error for unexpected frames

[JamesNK]

Spec says that Kestrel should return H3_FRAME_UNEXPECTED protocol error for unexpected frames

https://tools.ietf.org/html/draft-ietf-quic-http-33#section-4.1

Currently doing:

aspnetcore/src/Servers/Kestrel/Core/src/Internal/Http3/Http3Stream.cs

Lines 440 to 459 in 45867e0

	private Task ProcessHttp3Stream<TContext>(IHttpApplication<TContext> application, in ReadOnlySequence<byte> payload) where TContext : notnull
	{
	switch (_incomingFrame.Type)
	{
	case Http3FrameType.Data:
	return ProcessDataFrameAsync(payload);
	case Http3FrameType.Headers:
	return ProcessHeadersFrameAsync(application, payload);
	// need to be on control stream
	case Http3FrameType.DuplicatePush:
	case Http3FrameType.PushPromise:
	case Http3FrameType.Settings:
	case Http3FrameType.GoAway:
	case Http3FrameType.CancelPush:
	case Http3FrameType.MaxPushId:
	throw new Http3ConnectionException("HTTP_FRAME_UNEXPECTED");
	default:
	return ProcessUnknownFrameAsync();
	}
	}

Also check other places where Kestrel processes frame types.

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We're moving this issue to the Next sprint planning milestone for future evaluation / consideration. We will evaluate the request when we are planning the work for the next milestone. To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[BrennanConroy]

@wtgodbe Would you be interested in taking this on for preview3?

[wtgodbe]

@wtgodbe Would you be interested in taking this on for preview3?

Yup!

[JamesNK]

Fixed by #29665