tm2/pkg/p2p: *MultiplexTransport.Listen leaks net.Listener on port integerization error

[odeke-em]

gno/tm2/pkg/p2p/transport.go

Lines 248 to 251 in 2838ad1

	_, p, err := net.SplitHostPort(ln.Addr().String())
	if err != nil {
	return fmt.Errorf("error finding port (after listening on port 0): %w", err)
	}

leaks the allocation listener from

gno/tm2/pkg/p2p/transport.go

Lines 240 to 261 in 2838ad1

	ln, err := net.Listen("tcp", addr.DialString())
	if err != nil {
	return err
	}
	if addr.Port == 0 {
	// net.Listen on port 0 means the kernel will auto-allocate a port
	// - find out which one has been given to us.
	_, p, err := net.SplitHostPort(ln.Addr().String())
	if err != nil {
	return fmt.Errorf("error finding port (after listening on port 0): %w", err)
	}
	pInt, _ := strconv.Atoi(p)
	addr.Port = uint16(pInt)
	}
	mt.netAddr = addr
	mt.listener = ln
	go mt.acceptPeers()
	return nil

Remedy

Please invoke ln.Close() or please use Go's named returns to help you unconditionally errors so

func (mt *MultiplexTransport) Listen(addr NetAddress) (rerr error) { 
 	ln, err := net.Listen("tcp", addr.DialString()) 
 	if err != nil { 
 		return err
        }
        defer func() {
                 if rerr != nil {
                       ln.Close()
                 }
        }()

[kristovatlas]

Thanks for the report, @odeke-em. We're looking into it.