continue reworking StackNode implementations

arp/handler.go

@@ -9,6 +9,7 @@ import (
 )
 
 type Handler struct {
+	connID       uint64
 	ourHWAddr    []byte
 	ourProtoAddr []byte
 	htype        uint16
@@ -26,22 +27,31 @@ type HandlerConfig struct {
 	ProtocolType ethernet.Type
 }
 
-func NewHandler(cfg HandlerConfig) (*Handler, error) {
+func (c *Handler) Reset(cfg HandlerConfig) error {
 	if len(cfg.HardwareAddr) == 0 || len(cfg.HardwareAddr) > 255 ||
 		len(cfg.ProtocolAddr) == 0 || len(cfg.ProtocolAddr) > 255 {
-		return nil, errors.New("invalid Handler address config")
+		return errors.New("invalid Handler address config")
 	} else if cfg.MaxQueries <= 0 || cfg.MaxPending <= 0 {
-		return nil, errors.New("invalid Handler query or pending config")
+		return errors.New("invalid Handler query or pending config")
 	}
-	h := &Handler{
-		pending:      make([][sizeHeaderv6]byte, 0, cfg.MaxPending),
+	*c = Handler{
+		connID:       c.connID + 1,
+		ourHWAddr:    c.ourHWAddr[:0],
+		ourProtoAddr: c.ourProtoAddr[:0],
 		htype:        cfg.HardwareType,
 		protoType:    cfg.ProtocolType,
-		ourHWAddr:    cfg.HardwareAddr,
-		ourProtoAddr: cfg.ProtocolAddr,
-		queries:      make([]queryResult, 0, cfg.MaxQueries),
+		pending:      c.pending[:0],
+		queries:      c.queries[:0],
 	}
-	return h, nil
+	c.ourHWAddr = append(c.ourHWAddr, cfg.HardwareAddr...)
+	c.ourProtoAddr = append(c.ourProtoAddr, cfg.ProtocolAddr...)
+	if cap(c.pending) < cfg.MaxPending {
+		c.pending = make([][52]byte, cfg.MaxPending)[:0]
+	}
+	if cap(c.queries) < cfg.MaxQueries {
+		c.queries = make([]queryResult, cfg.MaxQueries)[:0]
+	}
+	return nil
 }
 
 type queryResult struct {
@@ -50,8 +60,8 @@ type queryResult struct {
 	querysent bool
 }
 
-// ResetState drops pending queries and incoming requests.
-func (c *Handler) ResetState() {
+// AbortPending drops pending queries and incoming requests.
+func (c *Handler) AbortPending() {
 	c.pending = c.pending[:0]
 	c.queries = c.queries[:0]
 }
@@ -60,6 +70,10 @@ func (c *Handler) expectSize() int {
 	return sizeHeader + 2*len(c.ourHWAddr) + 2*len(c.ourProtoAddr)
 }
 
+func (c *Handler) ConnectionID() *uint64 {
+	return &c.connID
+}
+
 func (c *Handler) QueryResult(protoAddr []byte) (hwAddr []byte, err error) {
 	for i := range c.queries {
 		if bytes.Equal(protoAddr, c.queries[i].protoaddr) {

arp/handler_test.go

@@ -5,11 +5,13 @@ import (
 	"log"
 	"testing"
 
+	"github.com/soypat/lneto"
 	"github.com/soypat/lneto/ethernet"
 )
 
 func TestHandler(t *testing.T) {
-	c1, err := NewHandler(HandlerConfig{
+	var c1, c2 Handler
+	err := c1.Reset(HandlerConfig{
 		HardwareAddr: []byte{0xde, 0xad, 0xbe, 0xef, 0x00, 0x00},
 		ProtocolAddr: []byte{192, 168, 1, 1},
 		MaxQueries:   1,
@@ -20,7 +22,7 @@ func TestHandler(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	c2, err := NewHandler(HandlerConfig{
+	err = c2.Reset(HandlerConfig{
 		HardwareAddr: []byte{0xc0, 0xff, 0xee, 0xc0, 0xff, 0xee},
 		ProtocolAddr: []byte{192, 168, 1, 2},
 		MaxQueries:   1,
@@ -58,6 +60,7 @@ func TestHandler(t *testing.T) {
 	} else if n == 0 {
 		t.Fatal("expected send of data after first query")
 	}
+	validateARP(t, buf[:])
 	err = c2.Recv(buf[:n]) // Receive request.
 	if err != nil {
 		t.Fatal(err)
@@ -69,6 +72,7 @@ func TestHandler(t *testing.T) {
 	} else if n == 0 {
 		t.Fatal("got no response to request")
 	}
+	validateARP(t, buf[:])
 	n, err = c2.Send(discard[:]) // Double tap check, should send nothing.
 	if err != nil {
 		t.Fatal("double tap send error:", err)
@@ -99,3 +103,19 @@ func TestHandler(t *testing.T) {
 		t.Fatal("expected no data")
 	}
 }
+
+func validateARP(t *testing.T, buf []byte) {
+	t.Helper()
+	afrm, err := NewFrame(buf)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	var vld lneto.Validator
+	afrm.ValidateSize(&vld)
+	if vld.HasError() {
+		t.Errorf("invalid arp: %s", vld.Err())
+	} else if err := vld.Err(); err != nil {
+		panic("unreachable: " + err.Error())
+	}
+}