add zero max ports error

internet/definitions.go

@@ -42,6 +42,7 @@ type node struct {
 }
 
 var (
+	errZeroMaxNodes    = errors.New("zero max ports")
 	errZeroPort        = errors.New("port must be greater than zero")
 	errInvalidProto    = errors.New("invalid protocol")
 	errProtoRegistered = errors.New("protocol already registered")

internet/stack-ethernet.go

@@ -36,6 +36,8 @@ func (ls *StackEthernet) HardwareAddr6() [6]byte {
 func (ls *StackEthernet) Reset6(mac, gateway [6]byte, mtu, maxNodes int) error {
 	if mtu > math.MaxUint16 || mtu < 256 {
 		return errors.New("invalid MTU")
+	} else if maxNodes <= 0 {
+		return errZeroMaxNodes
 	}
 	ls.handlers = slices.Grow(ls.handlers[:0], maxNodes)
 	*ls = StackEthernet{

internet/stack-ip.go

@@ -27,6 +27,9 @@ type StackIP struct {
 }
 
 func (sb *StackIP) Reset(addr netip.Addr, maxNodes int) error {
+	if maxNodes <= 0 {
+		return errZeroMaxNodes
+	}
 	err := sb.SetAddr(addr)
 	if err != nil {
 		return err

internet/stack-ports.go

@@ -27,6 +27,8 @@ func (ps *StackPorts) ResetTCP(maxNodes int) error {
 func (ps *StackPorts) Reset(protocol uint64, dstPortOffset uint16, maxNodes int) error {
 	if protocol > math.MaxUint16 {
 		return errInvalidProto
+	} else if maxNodes <= 0 {
+		return errZeroMaxNodes
 	}
 	ps.handlers = slices.Grow(ps.handlers[:0], maxNodes)
 	*ps = StackPorts{