add support for datagrams (#142)

* add support for datagrams

* add a test case

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/quic-go/quic-go v0.43.0
 	github.com/stretchr/testify v1.8.0
 	go.uber.org/mock v0.4.0
+	golang.org/x/exp v0.0.0-20230817173708-d852ddb80c63
 )
 
 require (
@@ -19,7 +20,6 @@ require (
 	github.com/quic-go/qpack v0.4.0 // indirect
 	github.com/rogpeppe/go-internal v1.10.0 // indirect
 	golang.org/x/crypto v0.14.0 // indirect
-	golang.org/x/exp v0.0.0-20230817173708-d852ddb80c63 // indirect
 	golang.org/x/mod v0.12.0 // indirect
 	golang.org/x/net v0.17.0 // indirect
 	golang.org/x/sys v0.15.0 // indirect

session.go

@@ -63,7 +63,7 @@ func (q *acceptQueue[T]) Chan() <-chan struct{} { return q.c }
 type Session struct {
 	sessionID  sessionID
 	qconn      http3.Connection
-	requestStr quic.Stream
+	requestStr http3.Stream
 
 	streamHdr    []byte
 	uniStreamHdr []byte
@@ -82,7 +82,7 @@ type Session struct {
 	streams streamsMap
 }
 
-func newSession(sessionID sessionID, qconn http3.Connection, requestStr quic.Stream) *Session {
+func newSession(sessionID sessionID, qconn http3.Connection, requestStr http3.Stream) *Session {
 	tracingID := qconn.Context().Value(quic.ConnectionTracingKey).(quic.ConnectionTracingID)
 	ctx, ctxCancel := context.WithCancel(context.WithValue(context.Background(), quic.ConnectionTracingKey, tracingID))
 	c := &Session{
@@ -390,6 +390,14 @@ func (s *Session) CloseWithError(code SessionErrorCode, msg string) error {
 	return err
 }
 
+func (s *Session) SendDatagram(b []byte) error {
+	return s.requestStr.SendDatagram(b)
+}
+
+func (s *Session) ReceiveDatagram(ctx context.Context) ([]byte, error) {
+	return s.requestStr.ReceiveDatagram(ctx)
+}
+
 func (s *Session) closeWithError(code SessionErrorCode, msg string) (bool /* first call to close session */, error) {
 	s.closeMx.Lock()
 	defer s.closeMx.Unlock()
@@ -413,6 +421,6 @@ func (s *Session) closeWithError(code SessionErrorCode, msg string) (bool /* fir
 	)
 }
 
-func (c *Session) ConnectionState() quic.ConnectionState {
-	return c.qconn.ConnectionState()
+func (s *Session) ConnectionState() quic.ConnectionState {
+	return s.qconn.ConnectionState()
 }

session_manager.go

@@ -164,7 +164,7 @@ func (m *sessionManager) handleUniStream(str quic.ReceiveStream, sess *session)
 }
 
 // AddSession adds a new WebTransport session.
-func (m *sessionManager) AddSession(qconn http3.Connection, id sessionID, requestStr quic.Stream) *Session {
+func (m *sessionManager) AddSession(qconn http3.Connection, id sessionID, requestStr http3.Stream) *Session {
 	conn := newSession(id, qconn, requestStr)
 	connTracingID := qconn.Context().Value(quic.ConnectionTracingKey).(quic.ConnectionTracingID)
 

session_test.go

@@ -7,20 +7,21 @@ import (
 	"time"
 
 	"github.com/quic-go/quic-go"
+	"github.com/quic-go/quic-go/http3"
 
 	"github.com/stretchr/testify/require"
 	"go.uber.org/mock/gomock"
 )
 
 //go:generate sh -c "go run go.uber.org/mock/mockgen -package webtransport -destination mock_connection_test.go github.com/quic-go/quic-go/http3 Connection && cat mock_connection_test.go | sed s@qerr\\.ApplicationErrorCode@quic.ApplicationErrorCode@g > tmp.go && mv tmp.go mock_connection_test.go && goimports -w mock_connection_test.go"
-//go:generate sh -c "go run go.uber.org/mock/mockgen -package webtransport -destination mock_stream_test.go github.com/quic-go/quic-go Stream && cat mock_stream_test.go | sed s@protocol\\.StreamID@quic.StreamID@g | sed s@qerr\\.StreamErrorCode@quic.StreamErrorCode@g > tmp.go && mv tmp.go mock_stream_test.go && goimports -w mock_stream_test.go"
+//go:generate sh -c "go run go.uber.org/mock/mockgen -package webtransport -destination mock_stream_test.go github.com/quic-go/quic-go/http3 Stream && cat mock_stream_test.go | sed s@protocol\\.StreamID@quic.StreamID@g | sed s@qerr\\.StreamErrorCode@quic.StreamErrorCode@g > tmp.go && mv tmp.go mock_stream_test.go && goimports -w mock_stream_test.go"
 
 type mockRequestStream struct {
 	*MockStream
 	c chan struct{}
 }
 
-func newMockRequestStream(ctrl *gomock.Controller) quic.Stream {
+func newMockRequestStream(ctrl *gomock.Controller) http3.Stream {
 	str := NewMockStream(ctrl)
 	str.EXPECT().Close()
 	str.EXPECT().CancelRead(gomock.Any())

webtransport_test.go

@@ -2,7 +2,6 @@ package webtransport_test
 
 import (
 	"context"
-	"crypto/rand"
 	"crypto/tls"
 	"errors"
 	"fmt"
@@ -15,6 +14,8 @@ import (
 	"testing"
 	"time"
 
+	"golang.org/x/exp/rand"
+
 	"github.com/quic-go/webtransport-go"
 
 	"github.com/quic-go/quic-go"
@@ -595,3 +596,57 @@ func TestWriteCloseRace(t *testing.T) {
 	<-ready
 	close(ch)
 }
+
+func TestDatagrams(t *testing.T) {
+	const num = 100
+	var mx sync.Mutex
+	m := make(map[string]bool, num)
+
+	var counter int
+	done := make(chan struct{})
+	serverErrChan := make(chan error, 1)
+	sess, closeServer := establishSession(t, func(sess *webtransport.Session) {
+		defer close(done)
+		for {
+			b, err := sess.ReceiveDatagram(context.Background())
+			if err != nil {
+				return
+			}
+			mx.Lock()
+			if _, ok := m[string(b)]; !ok {
+				serverErrChan <- errors.New("received unexpected datagram")
+				return
+			}
+			m[string(b)] = true
+			mx.Unlock()
+			counter++
+		}
+	})
+	defer closeServer()
+
+	errChan := make(chan error, 1)
+
+	for i := 0; i < num; i++ {
+		b := make([]byte, 800)
+		rand.Read(b)
+		mx.Lock()
+		m[string(b)] = false
+		mx.Unlock()
+		if err := sess.SendDatagram(b); err != nil {
+			break
+		}
+	}
+	time.Sleep(scaleDuration(10 * time.Millisecond))
+	sess.CloseWithError(0, "")
+	select {
+	case err := <-serverErrChan:
+		t.Fatal(err)
+	case err := <-errChan:
+		t.Fatal(err)
+	case <-done:
+		t.Logf("sent: %d, received: %d", num, counter)
+		require.Greater(t, counter, num*4/5)
+	case <-time.After(5 * time.Second):
+		t.Fatal("timeout")
+	}
+}