add stackbasic test

internal/ltesto/httptap.go

@@ -5,12 +5,10 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"log"
 	"log/slog"
 	"net/http"
 	"net/netip"
 	"net/url"
-	"time"
 
 	"github.com/soypat/lneto/internal"
 )
@@ -73,35 +71,6 @@ func (h *HTTPTapClient) Write(b []byte) (int, error) {
 
 func (h *HTTPTapClient) Close() error { return nil }
 
-func (h *HTTPTapClient) HandleTap(buf []byte) (HandleTapResult, error) {
-	nread, err := tap.Read(buf[:])
-	if err != nil {
-		slogger.error("tap-err", slog.String("err", err.Error()))
-		log.Fatal(err)
-	} else if nread > 0 {
-		err = lStack.RecvEth(buf[:nread])
-		if err != nil {
-			slogger.error("recv", slog.String("err", err.Error()), slog.Int("plen", nread))
-		} else {
-			slogger.info("recv", slog.Int("plen", nread))
-		}
-	}
-	nw, err := lStack.HandleEth(buf[:])
-	if err != nil {
-		slogger.error("handle", slog.String("err", err.Error()))
-	} else if nw > 0 {
-		_, err = tap.Write(buf[:nw])
-		if err != nil {
-			log.Fatal(err)
-		} else {
-			slogger.info("write", slog.Int("plen", nw))
-		}
-	}
-	if nread == 0 && nw == 0 {
-		time.Sleep(5 * time.Millisecond)
-	}
-}
-
 type HTTPTapServer struct {
 	router    *http.ServeMux
 	stack     stack

internet/basicstack.go

@@ -38,7 +38,8 @@ func (sb *StackBasic) Recv(frame []byte) error {
 	if err != nil {
 		return err
 	}
-	if *ifrm.DestinationAddr() != sb.ip {
+	dst := ifrm.DestinationAddr()
+	if *dst != sb.ip {
 		return errors.New("packet not for us")
 	}
 	sb.validator.ResetErr()

internet/stackbasic_test.go

@@ -0,0 +1,71 @@
+package internet
+
+import (
+	"math/rand"
+	"net/netip"
+	"testing"
+)
+
+func TestBasicStack(t *testing.T) {
+	rng := rand.New(rand.NewSource(1))
+	var sbCl, sbSv StackBasic
+	var connCl, connSv TCPConn
+	setupClientServer(t, rng, &sbCl, &sbSv, &connCl, &connSv)
+	var buf [2048]byte
+	n, err := sbCl.Handle(buf[:])
+	if err != nil {
+		t.Fatal(err)
+	} else if n == 0 {
+		t.Fatal("expected data exchange")
+	}
+	err = sbSv.Recv(buf[:n])
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func setupClientServer(t *testing.T, rng *rand.Rand, client, server *StackBasic, connClient, connServer *TCPConn) {
+	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())
+
+	err := connServer.Configure(&TCPConnConfig{
+		RxBuf:             make([]byte, bufsize),
+		TxBuf:             make([]byte, bufsize),
+		TxPacketQueueSize: 3,
+		Logger:            nil,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = connClient.Configure(&TCPConnConfig{
+		RxBuf:             make([]byte, bufsize),
+		TxBuf:             make([]byte, bufsize),
+		TxPacketQueueSize: 3,
+		Logger:            nil,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = connServer.OpenListen(svip.Port(), 200)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = connClient.OpenActive(svip, clip.Port(), 100)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = server.RegisterTCPConn(connServer)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = client.RegisterTCPConn(connClient)
+	if err != nil {
+		t.Fatal(err)
+	}
+}

internet/tcpconn.go

@@ -116,7 +116,10 @@ func (conn *TCPConn) HandleIP(buf []byte, off int) (n int, err error) {
 	if err != nil {
 		return 0, err
 	}
-	copy(raddr, conn.remoteAddr)
+	err = setDstAddr(buf[:off], conn.remoteAddr)
+	if err != nil {
+		return 0, err
+	}
 	return n, nil
 }
 
@@ -145,6 +148,31 @@ func getIPAddr(buf []byte) (addr []byte, err error) {
 	return addr, err
 }
 
+func setDstAddr(buf []byte, addr []byte) (err error) {
+	var dstaddr []byte
+	switch buf[0] >> 4 {
+	case 4:
+		ifrm4, err := ipv4.NewFrame(buf)
+		if err != nil {
+			return err
+		}
+		dstaddr = ifrm4.DestinationAddr()[:]
+	case 6:
+		ifrm6, err := ipv6.NewFrame(buf)
+		if err != nil {
+			return err
+		}
+		dstaddr = ifrm6.DestinationAddr()[:]
+	default:
+		err = errors.New("unsupported IP version")
+	}
+	if err == nil && len(dstaddr) != len(addr) {
+		return errors.New("invalid ip version to setDstAddr")
+	}
+	copy(dstaddr, addr)
+	return nil
+}
+
 func (conn *TCPConn) isRaddrSet() bool {
 	return len(conn.remoteAddr) != 0
 }