Fix #471

netstack2/tun_close_test.go

@@ -0,0 +1,56 @@
+package netstack2
+
+import (
+	"errors"
+	"net/netip"
+	"os"
+	"testing"
+	"time"
+
+	"gvisor.dev/gvisor/pkg/buffer"
+)
+
+// After Close, packets the stack emits must be dropped rather than blocking
+// the gVisor goroutine or panicking with "send on closed channel", and Read
+// must report os.ErrClosed.
+func TestNetTunCloseUnblocksSendersAndReaders(t *testing.T) {
+	dev, _, err := CreateNetTUN([]netip.Addr{netip.MustParseAddr("100.90.0.1")}, nil, 1280)
+	if err != nil {
+		t.Fatalf("CreateNetTUN: %v", err)
+	}
+	tn := dev.(*netTun)
+
+	readErr := make(chan error, 1)
+	go func() {
+		_, err := tn.Read([][]byte{make([]byte, 1500)}, []int{0}, 0)
+		readErr <- err
+	}()
+
+	if err := tn.Close(); err != nil {
+		t.Fatalf("Close: %v", err)
+	}
+	if err := tn.Close(); err != nil {
+		t.Fatalf("second Close: %v", err)
+	}
+
+	select {
+	case err := <-readErr:
+		if !errors.Is(err, os.ErrClosed) {
+			t.Fatalf("Read after Close: got %v, want os.ErrClosed", err)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("Read did not return after Close")
+	}
+
+	sent := make(chan struct{})
+	go func() {
+		tn.sendIncoming(buffer.NewViewWithData([]byte{0x45}))
+		tn.proxyHandler.QueueICMPReply([]byte{0x45})
+		close(sent)
+	}()
+	select {
+	case <-sent:
+	case <-time.After(5 * time.Second):
+		t.Fatal("sending a packet after Close blocked")
+	}
+}