send CONNECTION_CLOSE from the normal run loop

fixes #199

packet_packer.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"sync/atomic"
 
 	"github.com/lucas-clemente/quic-go/frames"
 	"github.com/lucas-clemente/quic-go/handshake"
@@ -20,12 +19,11 @@ type packedPacket struct {
 }
 
 type packetPacker struct {
+	connectionID     protocol.ConnectionID
+	version          protocol.VersionNumber
+	cryptoSetup      *handshake.CryptoSetup
 	lastPacketNumber protocol.PacketNumber
 
-	connectionID protocol.ConnectionID
-	version      protocol.VersionNumber
-	cryptoSetup  *handshake.CryptoSetup
-
 	connectionParametersManager *handshake.ConnectionParametersManager
 
 	streamFramer  *streamFramer
@@ -60,10 +58,8 @@ func (p *packetPacker) packPacket(stopWaitingFrame *frames.StopWaitingFrame, con
 		p.controlFrames = append(p.controlFrames, controlFrames...)
 	}
 
-	currentPacketNumber := protocol.PacketNumber(atomic.AddUint64(
-		(*uint64)(&p.lastPacketNumber),
-		1,
-	))
+	p.lastPacketNumber++
+	currentPacketNumber := p.lastPacketNumber
 
 	// cryptoSetup needs to be locked here, so that the AEADs are not changed between
 	// calling DiversificationNonce() and Seal().

session.go

@@ -68,8 +68,10 @@ type Session struct {
 
 	receivedPackets  chan receivedPacket
 	sendingScheduled chan struct{}
-	closeChan        chan struct{}
-	closed           uint32 // atomic bool
+	// closeChan is used to notify the run loop that it should terminate.
+	// If the value is not nil, the error is sent as a CONNECTION_CLOSE.
+	closeChan chan *qerr.QuicError
+	closed    uint32 // atomic bool
 
 	undecryptablePackets []receivedPacket
 	aeadChanged          chan struct{}
@@ -108,7 +110,7 @@ func newSession(conn connection, v protocol.VersionNumber, connectionID protocol
 		flowControlManager:          flowControlManager,
 		windowUpdateManager:         newWindowUpdateManager(),
 		receivedPackets:             make(chan receivedPacket, protocol.MaxSessionUnprocessedPackets),
-		closeChan:                   make(chan struct{}, 1),
+		closeChan:                   make(chan *qerr.QuicError, 1),
 		sendingScheduled:            make(chan struct{}, 1),
 		connectionParametersManager: connectionParametersManager,
 		undecryptablePackets:        make([]receivedPacket, 0, protocol.MaxUndecryptablePackets),
@@ -143,7 +145,10 @@ func (s *Session) run() {
 	for {
 		// Close immediately if requested
 		select {
-		case <-s.closeChan:
+		case errForConnClose := <-s.closeChan:
+			if errForConnClose != nil {
+				s.sendConnectionClose(errForConnClose)
+			}
 			return
 		default:
 		}
@@ -152,7 +157,10 @@ func (s *Session) run() {
 
 		var err error
 		select {
-		case <-s.closeChan:
+		case errForConnClose := <-s.closeChan:
+			if errForConnClose != nil {
+				s.sendConnectionClose(errForConnClose)
+			}
 			return
 		case <-s.timer.C:
 			s.timerRead = true
@@ -380,7 +388,6 @@ func (s *Session) closeImpl(e error, remoteClose bool) error {
 	if !atomic.CompareAndSwapUint32(&s.closed, 0, 1) {
 		return nil
 	}
-	s.closeChan <- struct{}{}
 
 	if e == nil {
 		e = qerr.PeerGoingAway
@@ -391,14 +398,19 @@ func (s *Session) closeImpl(e error, remoteClose bool) error {
 	s.closeCallback(s.connectionID)
 
 	if remoteClose {
+		// If this is a remote close we don't need to send a CONNECTION_CLOSE
+		s.closeChan <- nil
 		return nil
 	}
 
 	quicErr := qerr.ToQuicError(e)
 	if quicErr.ErrorCode == qerr.DecryptionFailure {
+		// If we send a public reset, don't send a CONNECTION_CLOSE
+		s.closeChan <- nil
 		return s.sendPublicReset(s.lastRcvdPacketNumber)
 	}
-	return s.sendConnectionClose(quicErr)
+	s.closeChan <- quicErr
+	return nil
 }
 
 func (s *Session) closeStreamsWithError(err error) {