add a generic Log() function to the connection tracer

logging/interface.go

@@ -126,4 +126,5 @@ type ConnectionTracer interface {
 	LossTimerCanceled()
 	// Close is called when the connection is closed.
 	Close()
+	Debug(name, msg string)
 }

logging/mock_connection_tracer_test.go

@@ -74,6 +74,18 @@ func (mr *MockConnectionTracerMockRecorder) ClosedConnection(arg0 interface{}) *
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ClosedConnection", reflect.TypeOf((*MockConnectionTracer)(nil).ClosedConnection), arg0)
 }
 
+// Debug mocks base method
+func (m *MockConnectionTracer) Debug(arg0, arg1 string) {
+	m.ctrl.T.Helper()
+	m.ctrl.Call(m, "Debug", arg0, arg1)
+}
+
+// Debug indicates an expected call of Debug
+func (mr *MockConnectionTracerMockRecorder) Debug(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Debug", reflect.TypeOf((*MockConnectionTracer)(nil).Debug), arg0, arg1)
+}
+
 // DroppedEncryptionLevel mocks base method
 func (m *MockConnectionTracer) DroppedEncryptionLevel(arg0 protocol.EncryptionLevel) {
 	m.ctrl.T.Helper()

logging/multiplex.go

@@ -186,6 +186,12 @@ func (m *connTracerMultiplexer) LossTimerCanceled() {
 	}
 }
 
+func (m *connTracerMultiplexer) Debug(name, msg string) {
+	for _, t := range m.tracers {
+		t.Debug(name, msg)
+	}
+}
+
 func (m *connTracerMultiplexer) Close() {
 	for _, t := range m.tracers {
 		t.Close()