TUN-4597: Add a QUIC server skeleton

- Added a QUIC server to accept streams
- Unit test for this server also tests ALPN
- Temporary echo capability for HTTP ConnectionType

vendor/github.com/lucas-clemente/quic-go/framer.go

@@ -0,0 +1,171 @@
+package quic
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/lucas-clemente/quic-go/internal/ackhandler"
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/wire"
+	"github.com/lucas-clemente/quic-go/quicvarint"
+)
+
+type framer interface {
+	HasData() bool
+
+	QueueControlFrame(wire.Frame)
+	AppendControlFrames([]ackhandler.Frame, protocol.ByteCount) ([]ackhandler.Frame, protocol.ByteCount)
+
+	AddActiveStream(protocol.StreamID)
+	AppendStreamFrames([]ackhandler.Frame, protocol.ByteCount) ([]ackhandler.Frame, protocol.ByteCount)
+
+	Handle0RTTRejection() error
+}
+
+type framerI struct {
+	mutex sync.Mutex
+
+	streamGetter streamGetter
+	version      protocol.VersionNumber
+
+	activeStreams map[protocol.StreamID]struct{}
+	streamQueue   []protocol.StreamID
+
+	controlFrameMutex sync.Mutex
+	controlFrames     []wire.Frame
+}
+
+var _ framer = &framerI{}
+
+func newFramer(
+	streamGetter streamGetter,
+	v protocol.VersionNumber,
+) framer {
+	return &framerI{
+		streamGetter:  streamGetter,
+		activeStreams: make(map[protocol.StreamID]struct{}),
+		version:       v,
+	}
+}
+
+func (f *framerI) HasData() bool {
+	f.mutex.Lock()
+	hasData := len(f.streamQueue) > 0
+	f.mutex.Unlock()
+	if hasData {
+		return true
+	}
+	f.controlFrameMutex.Lock()
+	hasData = len(f.controlFrames) > 0
+	f.controlFrameMutex.Unlock()
+	return hasData
+}
+
+func (f *framerI) QueueControlFrame(frame wire.Frame) {
+	f.controlFrameMutex.Lock()
+	f.controlFrames = append(f.controlFrames, frame)
+	f.controlFrameMutex.Unlock()
+}
+
+func (f *framerI) AppendControlFrames(frames []ackhandler.Frame, maxLen protocol.ByteCount) ([]ackhandler.Frame, protocol.ByteCount) {
+	var length protocol.ByteCount
+	f.controlFrameMutex.Lock()
+	for len(f.controlFrames) > 0 {
+		frame := f.controlFrames[len(f.controlFrames)-1]
+		frameLen := frame.Length(f.version)
+		if length+frameLen > maxLen {
+			break
+		}
+		frames = append(frames, ackhandler.Frame{Frame: frame})
+		length += frameLen
+		f.controlFrames = f.controlFrames[:len(f.controlFrames)-1]
+	}
+	f.controlFrameMutex.Unlock()
+	return frames, length
+}
+
+func (f *framerI) AddActiveStream(id protocol.StreamID) {
+	f.mutex.Lock()
+	if _, ok := f.activeStreams[id]; !ok {
+		f.streamQueue = append(f.streamQueue, id)
+		f.activeStreams[id] = struct{}{}
+	}
+	f.mutex.Unlock()
+}
+
+func (f *framerI) AppendStreamFrames(frames []ackhandler.Frame, maxLen protocol.ByteCount) ([]ackhandler.Frame, protocol.ByteCount) {
+	var length protocol.ByteCount
+	var lastFrame *ackhandler.Frame
+	f.mutex.Lock()
+	// pop STREAM frames, until less than MinStreamFrameSize bytes are left in the packet
+	numActiveStreams := len(f.streamQueue)
+	for i := 0; i < numActiveStreams; i++ {
+		if protocol.MinStreamFrameSize+length > maxLen {
+			break
+		}
+		id := f.streamQueue[0]
+		f.streamQueue = f.streamQueue[1:]
+		// This should never return an error. Better check it anyway.
+		// The stream will only be in the streamQueue, if it enqueued itself there.
+		str, err := f.streamGetter.GetOrOpenSendStream(id)
+		// The stream can be nil if it completed after it said it had data.
+		if str == nil || err != nil {
+			delete(f.activeStreams, id)
+			continue
+		}
+		remainingLen := maxLen - length
+		// For the last STREAM frame, we'll remove the DataLen field later.
+		// Therefore, we can pretend to have more bytes available when popping
+		// the STREAM frame (which will always have the DataLen set).
+		remainingLen += quicvarint.Len(uint64(remainingLen))
+		frame, hasMoreData := str.popStreamFrame(remainingLen)
+		if hasMoreData { // put the stream back in the queue (at the end)
+			f.streamQueue = append(f.streamQueue, id)
+		} else { // no more data to send. Stream is not active any more
+			delete(f.activeStreams, id)
+		}
+		// The frame can be nil
+		// * if the receiveStream was canceled after it said it had data
+		// * the remaining size doesn't allow us to add another STREAM frame
+		if frame == nil {
+			continue
+		}
+		frames = append(frames, *frame)
+		length += frame.Length(f.version)
+		lastFrame = frame
+	}
+	f.mutex.Unlock()
+	if lastFrame != nil {
+		lastFrameLen := lastFrame.Length(f.version)
+		// account for the smaller size of the last STREAM frame
+		lastFrame.Frame.(*wire.StreamFrame).DataLenPresent = false
+		length += lastFrame.Length(f.version) - lastFrameLen
+	}
+	return frames, length
+}
+
+func (f *framerI) Handle0RTTRejection() error {
+	f.mutex.Lock()
+	defer f.mutex.Unlock()
+
+	f.controlFrameMutex.Lock()
+	f.streamQueue = f.streamQueue[:0]
+	for id := range f.activeStreams {
+		delete(f.activeStreams, id)
+	}
+	var j int
+	for i, frame := range f.controlFrames {
+		switch frame.(type) {
+		case *wire.MaxDataFrame, *wire.MaxStreamDataFrame, *wire.MaxStreamsFrame:
+			return errors.New("didn't expect MAX_DATA / MAX_STREAM_DATA / MAX_STREAMS frame to be sent in 0-RTT")
+		case *wire.DataBlockedFrame, *wire.StreamDataBlockedFrame, *wire.StreamsBlockedFrame:
+			continue
+		default:
+			f.controlFrames[j] = f.controlFrames[i]
+			j++
+		}
+	}
+	f.controlFrames = f.controlFrames[:j]
+	f.controlFrameMutex.Unlock()
+	return nil
+}