use the connection ID from the preferred_address transport parameter

conn_id_manager.go

@@ -53,6 +53,10 @@ func newConnIDManager(
 	}
 }
 
+func (h *connIDManager) AddFromPreferredAddress(connID protocol.ConnectionID, resetToken *[16]byte) error {
+	return h.addConnectionID(1, connID, resetToken)
+}
+
 func (h *connIDManager) Add(f *wire.NewConnectionIDFrame) error {
 	if err := h.add(f); err != nil {
 		return err
@@ -64,7 +68,7 @@ func (h *connIDManager) Add(f *wire.NewConnectionIDFrame) error {
 }
 
 func (h *connIDManager) add(f *wire.NewConnectionIDFrame) error {
-	// If the NEW_CONNECTION_ID frame is reordered, such that its sequenece number
+	// If the NEW_CONNECTION_ID frame is reordered, such that its sequence number
 	// was already retired, send the RETIRE_CONNECTION_ID frame immediately.
 	if f.SequenceNumber < h.highestRetired {
 		h.queueControlFrame(&wire.RetireConnectionIDFrame{
@@ -94,34 +98,8 @@ func (h *connIDManager) add(f *wire.NewConnectionIDFrame) error {
 		return nil
 	}
 
-	// insert a new element at the end
+	if err := h.addConnectionID(f.SequenceNumber, f.ConnectionID, &f.StatelessResetToken); err != nil {
-	if h.queue.Len() == 0 || h.queue.Back().Value.SequenceNumber < f.SequenceNumber {
+		return err
-		h.queue.PushBack(utils.NewConnectionID{
-			SequenceNumber:      f.SequenceNumber,
-			ConnectionID:        f.ConnectionID,
-			StatelessResetToken: &f.StatelessResetToken,
-		})
-	} else {
-		// insert a new element somewhere in the middle
-		for el := h.queue.Front(); el != nil; el = el.Next() {
-			if el.Value.SequenceNumber == f.SequenceNumber {
-				if !el.Value.ConnectionID.Equal(f.ConnectionID) {
-					return fmt.Errorf("received conflicting connection IDs for sequence number %d", f.SequenceNumber)
-				}
-				if *el.Value.StatelessResetToken != f.StatelessResetToken {
-					return fmt.Errorf("received conflicting stateless reset tokens for sequence number %d", f.SequenceNumber)
-				}
-				break
-			}
-			if el.Value.SequenceNumber > f.SequenceNumber {
-				h.queue.InsertBefore(utils.NewConnectionID{
-					SequenceNumber:      f.SequenceNumber,
-					ConnectionID:        f.ConnectionID,
-					StatelessResetToken: &f.StatelessResetToken,
-				}, el)
-				break
-			}
-		}
 	}
 
 	// Retire the active connection ID, if necessary.
@@ -132,6 +110,39 @@ func (h *connIDManager) add(f *wire.NewConnectionIDFrame) error {
 	return nil
 }
 
+func (h *connIDManager) addConnectionID(seq uint64, connID protocol.ConnectionID, resetToken *[16]byte) error {
+	// insert a new element at the end
+	if h.queue.Len() == 0 || h.queue.Back().Value.SequenceNumber < seq {
+		h.queue.PushBack(utils.NewConnectionID{
+			SequenceNumber:      seq,
+			ConnectionID:        connID,
+			StatelessResetToken: resetToken,
+		})
+		return nil
+	}
+	// insert a new element somewhere in the middle
+	for el := h.queue.Front(); el != nil; el = el.Next() {
+		if el.Value.SequenceNumber == seq {
+			if !el.Value.ConnectionID.Equal(connID) {
+				return fmt.Errorf("received conflicting connection IDs for sequence number %d", seq)
+			}
+			if *el.Value.StatelessResetToken != *resetToken {
+				return fmt.Errorf("received conflicting stateless reset tokens for sequence number %d", seq)
+			}
+			break
+		}
+		if el.Value.SequenceNumber > seq {
+			h.queue.InsertBefore(utils.NewConnectionID{
+				SequenceNumber:      seq,
+				ConnectionID:        connID,
+				StatelessResetToken: resetToken,
+			}, el)
+			break
+		}
+	}
+	return nil
+}
+
 func (h *connIDManager) updateConnectionID() {
 	h.queueControlFrame(&wire.RetireConnectionIDFrame{
 		SequenceNumber: h.activeSequenceNumber,

conn_id_manager_test.go

@@ -80,13 +80,18 @@ var _ = Describe("Connection ID Manager", func() {
 	})
 
 	It("accepts duplicates", func() {
-		f := &wire.NewConnectionIDFrame{
+		f1 := &wire.NewConnectionIDFrame{
 			SequenceNumber:      1,
 			ConnectionID:        protocol.ConnectionID{1, 2, 3, 4},
 			StatelessResetToken: [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xa, 0xb, 0xc, 0xd, 0xe},
 		}
-		Expect(m.Add(f)).To(Succeed())
+		f2 := &wire.NewConnectionIDFrame{
-		Expect(m.Add(f)).To(Succeed())
+			SequenceNumber:      1,
+			ConnectionID:        protocol.ConnectionID{1, 2, 3, 4},
+			StatelessResetToken: [16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xa, 0xb, 0xc, 0xd, 0xe},
+		}
+		Expect(m.Add(f1)).To(Succeed())
+		Expect(m.Add(f2)).To(Succeed())
 		c1, rt1 := get()
 		Expect(c1).To(Equal(protocol.ConnectionID{1, 2, 3, 4}))
 		Expect(*rt1).To(Equal([16]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xa, 0xb, 0xc, 0xd, 0xe}))

session.go

@@ -1196,7 +1196,7 @@ func (s *session) processTransportParameters(params *handshake.TransportParamete
 	if params.PreferredAddress != nil {
 		s.logger.Debugf("Server sent preferred_address. Retiring the preferred_address connection ID.")
 		// Retire the connection ID.
-		s.framer.QueueControlFrame(&wire.RetireConnectionIDFrame{SequenceNumber: 1})
+		s.connIDManager.AddFromPreferredAddress(params.PreferredAddress.ConnectionID, &params.PreferredAddress.StatelessResetToken)
 	}
 	// On the server side, the early session is ready as soon as we processed
 	// the client's transport parameters.

session_test.go

@@ -1955,20 +1955,26 @@ var _ = Describe("Client Session", func() {
 			Eventually(sess.Context().Done()).Should(BeClosed())
 		})
 
-		It("immediately retires the preferred_address connection ID", func() {
+		It("uses the preferred_address connection ID", func() {
 			params := &handshake.TransportParameters{
 				PreferredAddress: &handshake.PreferredAddress{
-					IPv4:         net.IPv4(127, 0, 0, 1),
+					IPv4:                net.IPv4(127, 0, 0, 1),
-					IPv6:         net.IP{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16},
+					IPv6:                net.IP{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16},
-					ConnectionID: protocol.ConnectionID{1, 2, 3, 4},
+					ConnectionID:        protocol.ConnectionID{1, 2, 3, 4},
+					StatelessResetToken: [16]byte{16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1},
 				},
 			}
 			packer.EXPECT().HandleTransportParameters(gomock.Any())
 			packer.EXPECT().PackCoalescedPacket().MaxTimes(1)
 			sess.processTransportParameters(params)
+			// make sure the connection ID is not retired
 			cf, _ := sess.framer.AppendControlFrames(nil, protocol.MaxByteCount)
-			Expect(cf).To(HaveLen(1))
+			Expect(cf).To(BeEmpty())
-			Expect(cf[0].Frame).To(Equal(&wire.RetireConnectionIDFrame{SequenceNumber: 1}))
+			sessionRunner.EXPECT().AddResetToken([16]byte{16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1}, sess)
+			Expect(sess.connIDManager.Get()).To(Equal(protocol.ConnectionID{1, 2, 3, 4}))
+			// shut down
+			sessionRunner.EXPECT().RemoveResetToken([16]byte{16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1})
+			expectClose()
 		})
 
 		It("uses the minimum of the peers' idle timeouts", func() {