Add class ID parsing to parseU32Data

This patch adds a new switch case that handles the class ID attribute of
the U32 filter data listed by FilterList. Without this case block the
class ID of the U32 filter is always set to zero. The new test
conditions are added to TestFilterAddDel and TestFilterU32BpfAddDel in
filter_test.go as well.

Signed-off-by: Taku Fukushima <taku@soracom.jp>

filter_linux.go

@@ -443,6 +443,8 @@ func parseU32Data(filter Filter, data []syscall.NetlinkRouteAttr) (bool, error)
 					u32.RedirIndex = int(action.Ifindex)
 				}
 			}
+		case nl.TCA_U32_CLASSID:
+			u32.ClassId = native.Uint32(datum.Value)
 		}
 	}
 	return detailed, nil

filter_test.go

@@ -51,6 +51,7 @@ func TestFilterAddDel(t *testing.T) {
 	if !ok {
 		t.Fatal("Qdisc is the wrong type")
 	}
+	classId := MakeHandle(1, 1)
 	filter := &U32{
 		FilterAttrs: FilterAttrs{
 			LinkIndex: link.Attrs().Index,
@@ -59,6 +60,7 @@ func TestFilterAddDel(t *testing.T) {
 			Protocol:  syscall.ETH_P_IP,
 		},
 		RedirIndex: redir.Attrs().Index,
+		ClassId:    classId,
 	}
 	if err := FilterAdd(filter); err != nil {
 		t.Fatal(err)
@@ -70,6 +72,13 @@ func TestFilterAddDel(t *testing.T) {
 	if len(filters) != 1 {
 		t.Fatal("Failed to add filter")
 	}
+	u32, ok := filters[0].(*U32)
+	if !ok {
+		t.Fatal("Filter is the wrong type")
+	}
+	if u32.ClassId != classId {
+		t.Fatalf("ClassId of the filter is the wrong value")
+	}
 	if err := FilterDel(filter); err != nil {
 		t.Fatal(err)
 	}
@@ -296,6 +305,7 @@ func TestFilterU32BpfAddDel(t *testing.T) {
 	if err != nil {
 		t.Skipf("Loading bpf program failed: %s", err)
 	}
+	classId := MakeHandle(1, 1)
 	filter := &U32{
 		FilterAttrs: FilterAttrs{
 			LinkIndex: link.Attrs().Index,
@@ -303,7 +313,7 @@ func TestFilterU32BpfAddDel(t *testing.T) {
 			Priority:  1,
 			Protocol:  syscall.ETH_P_ALL,
 		},
-		ClassId: MakeHandle(1, 1),
+		ClassId: classId,
 		Actions: []Action{
 			&BpfAction{Fd: fd, Name: "simple"},
 			&MirredAction{
@@ -335,6 +345,9 @@ func TestFilterU32BpfAddDel(t *testing.T) {
 	if len(u32.Actions) != 2 {
 		t.Fatalf("Too few Actions in filter")
 	}
+	if u32.ClassId != classId {
+		t.Fatalf("ClassId of the filter is the wrong value")
+	}
 	bpfAction, ok := u32.Actions[0].(*BpfAction)
 	if !ok {
 		t.Fatal("Action[0] is the wrong type")