From 63dc5d107943ac22b0d5d9b9f758a29612120d63 Mon Sep 17 00:00:00 2001
From: soypat <graded.sp@gmail.com>
Date: Tue, 15 Jul 2025 00:57:24 -0300
Subject: [PATCH] add zero max ports error

---
 internet/definitions.go    | 1 +
 internet/stack-ethernet.go | 2 ++
 internet/stack-ip.go       | 3 +++
 internet/stack-ports.go    | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/internet/definitions.go b/internet/definitions.go
index 99aebc1..da5c8be 100644
--- a/internet/definitions.go
+++ b/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")
diff --git a/internet/stack-ethernet.go b/internet/stack-ethernet.go
index dd77a1c..37d2622 100644
--- a/internet/stack-ethernet.go
+++ b/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{
diff --git a/internet/stack-ip.go b/internet/stack-ip.go
index 8ef4c29..1264042 100644
--- a/internet/stack-ip.go
+++ b/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
diff --git a/internet/stack-ports.go b/internet/stack-ports.go
index 29e3a98..a9087d1 100644
--- a/internet/stack-ports.go
+++ b/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{