Add proper EOF return from route group's Read

pkg/router/route_group.go

@@ -152,11 +152,19 @@ func (rg *RouteGroup) Read(p []byte) (n int, err error) {
 	}
 	rg.mu.Unlock()
 
-	var data []byte
+	var (
+		data []byte
+		ok   bool
+	)
 	select {
 	case <-rg.readDeadline.Wait():
 		return 0, timeoutError{}
-	case data = <-rg.readCh:
+	case data, ok = <-rg.readCh:
+	}
+
+	if !ok {
+		// route group got closed
+		return 0, io.EOF
 	}
 
 	rg.mu.Lock()

pkg/router/router.go

@@ -368,12 +368,9 @@ func (r *router) handleDataPacket(ctx context.Context, packet routing.Packet) er
 	r.logger.Infof("Got new remote packet with route ID %d. Using rule: %s", packet.RouteID(), rule)
 	r.logger.Infof("Packet contents (len = %d): %v", len(packet.Payload()), packet.Payload())
 
-	if rg.isClosed() {
-		return io.ErrClosedPipe
-	}
-
-	rg.mu.Lock()
-	defer rg.mu.Unlock()
+	// TODO: test that it's not needed indeed
+	/*rg.mu.Lock()
+	defer rg.mu.Unlock()*/
 
 	select {
 	case <-rg.done:
@@ -425,12 +422,12 @@ func (r *router) handleClosePacket(ctx context.Context, packet routing.Packet) e
 	r.logger.Infof("Got new remote close packet with route ID %d. Using rule: %s", packet.RouteID(), rule)
 	r.logger.Infof("Packet contents (len = %d): %v", len(packet.Payload()), packet.Payload())
 
+	closeCode := routing.CloseCode(packet.Payload()[0])
+
 	if rg.isClosed() {
 		return io.ErrClosedPipe
 	}
 
-	closeCode := routing.CloseCode(packet.Payload()[0])
-
 	if err := rg.handleClosePacket(closeCode); err != nil {
 		return fmt.Errorf("error handling close packet with code %d by route group with descriptor %s: %w",
 			closeCode, &desc, err)