remove NodeARP in favor of arp.Handler; fix bug in IP stack node handling; use registerNode where applicable

examples/bridge/main.go

@@ -224,7 +224,7 @@ func run() (err error) {
 type Stack struct {
 	link    internet.StackEthernet
 	ip      internet.StackIP
-	arp     internet.NodeARP
+	arp     arp.Handler
 	udps    internet.StackPorts
 	dhcp    dhcpv4.Client
 	dns     dns.Client
@@ -427,7 +427,7 @@ func (s *Stack) ResultResolveHardwareAddress6(ip netip.Addr) (hw [6]byte, err er
 	if err != nil {
 		return hw, err
 	} else if len(hwslice) != 6 {
-		panic("unreachable slice hw leng")
+		panic("unreachable slice hw length")
 	}
 	return [6]byte(hwslice), nil
 }

examples/stack/main.go

@@ -181,7 +181,7 @@ type Stack struct {
 	ethernet internet.StackEthernet
 	ip       internet.StackIP
 	tcpports internet.StackPorts
-	arp      internet.NodeARP
+	arp      arp.Handler
 }
 
 func (stack *Stack) Reset(ourMAC, gwMAC [6]byte, ip netip.Addr, mtu int) (err error) {

examples/stackbasic/main.go

@@ -195,7 +195,7 @@ func NewEthernetTCPStack(ourMAC, gwMAC [6]byte, ip netip.AddrPort, mtu uint16, s
 	if err != nil {
 		return nil, nil, err
 	}
-	err = ipStack.RegisterTCPConn(&conn)
+	err = ipStack.Register(&conn)
 	if err != nil {
 		return nil, nil, err
 	}

internet/definitions.go

@@ -75,12 +75,12 @@ func handleNodeError(nodesPtr *[]node, nodeIdx int, err error) (discarded bool)
 	return discarded
 }
 
-func checkNode(node *node) (discard bool) {
-	return node.demux == nil || node.connID != nil && node.currConnID != *node.connID
+func (node *node) IsInvalid() bool {
+	return node.demux == nil || node.encapsulate == nil || (node.connID != nil && node.currConnID != *node.connID)
 }
 
 func checkNodeErr(node *node, err error) (discard bool) {
-	return checkNode(node) || (err != nil && err == net.ErrClosed)
+	return node.IsInvalid() || (err != nil && err == net.ErrClosed)
 }
 
 func nodeFromStackNode(s StackNode, port uint16, protocol uint64) node {
@@ -116,7 +116,7 @@ func getEncapsulateNode(nodes *[]node, carrierData []byte, frameOffset int) (nod
 	destroyed := false
 	for i := range *nodes {
 		node := &(*nodes)[i]
-		if checkNode(node) {
+		if node.IsInvalid() {
 			destroyed = true
 			node.destroy()
 			continue
@@ -153,7 +153,7 @@ func getNodeByProto(nodes []node, protocol uint16) int {
 func nodesCompact(nodes []node) []node {
 	nilOff := 0
 	for i := 0; i < len(nodes); i++ {
-		if !checkNode(&nodes[i]) {
+		if !nodes[i].IsInvalid() {
 			nodes[nilOff] = nodes[i]
 			nilOff++
 		}

internet/stack-ethernet.go

@@ -69,12 +69,11 @@ func (ls *StackEthernet) Register(h StackNode) error {
 			return errProtoRegistered
 		}
 	}
-	ls.handlers = append(ls.handlers, node{
+	return registerNode(&ls.handlers, node{
 		demux:       h.Demux,
 		encapsulate: h.Encapsulate,
 		proto:       eproto,
 	})
-	return nil
 }
 
 func (ls *StackEthernet) Demux(carrierData []byte, frameOffset int) (err error) {

internet/stack-ip.go

@@ -200,25 +200,19 @@ func (sb *StackIP) Register(h StackNode) error {
 	if proto > 255 {
 		return errInvalidProto
 	}
-	sb.handlers = append(sb.handlers, node{
+	connID := h.ConnectionID()
+	var currConnID uint64
+	if connID != nil {
+		currConnID = *connID
+	}
+	return registerNode(&sb.handlers, node{
 		demux:       h.Demux,
 		encapsulate: h.Encapsulate,
 		proto:       uint16(proto),
+		port:        h.LocalPort(),
+		currConnID:  currConnID,
+		connID:      connID,
 	})
-	return nil
-}
-
-func (sb *StackIP) RegisterTCPConn(conn *tcp.Conn) error {
-	if conn.LocalPort() == 0 {
-		return errZeroPort
-	}
-	sb.handlers = append(sb.handlers, node{
-		demux:       conn.Demux,
-		encapsulate: conn.Encapsulate,
-		proto:       uint16(lneto.IPProtoTCP),
-		port:        conn.LocalPort(),
-	})
-	return nil
 }
 
 type logger struct {

internet/stack-ports.go

@@ -50,6 +50,9 @@ func (ps *StackPorts) Encapsulate(b []byte, offset int) (n int, err error) {
 	}
 	var i int
 	for i = 0; i < len(ps.handlers); i++ {
+		if ps.handlers[i].IsInvalid() {
+			continue
+		}
 		n, err = ps.handlers[i].encapsulate(b, offset)
 		if err != nil || n > 0 {
 			if ps.handleResult(i, n, err) {

internet/stack-udpport.go

@@ -29,7 +29,7 @@ func (sudp *StackUDPPort) LocalPort() uint16 { return sudp.h.port }
 func (sudp *StackUDPPort) ConnectionID() *uint64 { return sudp.h.connID }
 
 func (sudp *StackUDPPort) Demux(carrierData []byte, frameOffset int) error {
-	if checkNode(&sudp.h) {
+	if sudp.h.IsInvalid() {
 		sudp.h.destroy()
 		return net.ErrClosed
 	}
@@ -62,7 +62,7 @@ func (sudp *StackUDPPort) Demux(carrierData []byte, frameOffset int) error {
 }
 
 func (sudp *StackUDPPort) Encapsulate(carrierData []byte, frameOffset int) (int, error) {
-	if checkNode(&sudp.h) {
+	if sudp.h.IsInvalid() {
 		sudp.h.destroy()
 		return 0, net.ErrClosed
 	}

internet/stackbasic_test.go

@@ -86,12 +86,13 @@ func setupClientServerEstablished(t *testing.T, rng *rand.Rand, client, server *
 }
 
 func setupClientServer(t *testing.T, rng *rand.Rand, client, server *StackIP, connClient, connServer *tcp.Conn) {
+	const maxNodes = 1
 	bufsize := 2048
 	// Ensure buffer sizes are OK with reused buffers.
 	svip := netip.AddrPortFrom(netip.AddrFrom4([4]byte{192, 168, 1, 0}), 80)
 	clip := netip.AddrPortFrom(netip.AddrFrom4([4]byte{192, 168, 1, 1}), 1337)
-	server.SetAddr(svip.Addr())
-	client.SetAddr(clip.Addr())
+	server.Reset(svip.Addr(), maxNodes)
+	client.Reset(clip.Addr(), maxNodes)
 
 	err := connServer.Configure(&tcp.ConnConfig{
 		RxBuf:             make([]byte, bufsize),
@@ -121,11 +122,11 @@ func setupClientServer(t *testing.T, rng *rand.Rand, client, server *StackIP, co
 		t.Fatal(err)
 	}
 
-	err = server.RegisterTCPConn(connServer)
+	err = server.Register(connServer)
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = client.RegisterTCPConn(connClient)
+	err = client.Register(connClient)
 	if err != nil {
 		t.Fatal(err)
 	}