feat: GetMapsIdsByName

Allow a user to get a list of maps Ids filtered by map name.

libbpfgo.go

@@ -393,31 +393,36 @@ func (m *Module) InitGlobalVariable(name string, value interface{}) error {
 	return err
 }
 
-// GetMapsByName retrieves BPF maps with the specified name.
-func GetMapsByName(name string) []*BPFMapLow {
-	bpfMaps := []*BPFMapLow{}
+// GetMapsIdsByName searches for maps with a given name.
+// It returns a slice of unsigned 32-bit integers representing the IDs of matching maps.
+func GetMapsIdsByName(name string) []uint32 {
+	bpfMapsIds := []uint32{}
 
 	startId := C.uint(0)
 	nextId := C.uint(0)
 
 	for {
 		err := C.bpf_map_get_next_id(startId, &nextId)
 		if err != 0 {
-			return bpfMaps
+			return bpfMapsIds
 		}
 
 		startId = nextId + 1
 
 		bpfMapLow, errMap := GetMapByID(uint32(nextId))
 		if errMap != nil {
-			return bpfMaps
+			return bpfMapsIds
+		}
+
+		if err := syscall.Close(bpfMapLow.FileDescriptor()); err != nil {
+			return bpfMapsIds
 		}
 
 		if bpfMapLow.Name() != name {
 			continue
 		}
 
-		bpfMaps = append(bpfMaps, bpfMapLow)
+		bpfMapsIds = append(bpfMapsIds, bpfMapLow.info.ID)
 	}
 }
 

selftest/map-get-maps-by-name/main.go

@@ -10,6 +10,8 @@ import (
 	bpf "github.com/aquasecurity/libbpfgo"
 )
 
+const BPFMapName = "test"
+
 func main() {
 	bpfModule, err := bpf.NewModuleFromFile("main.bpf.o")
 	if err != nil {
@@ -20,16 +22,23 @@ func main() {
 
 	bpfModule.BPFLoadObject()
 
-	testMaps := bpf.GetMapsByName("test")
-	if len(testMaps) == 0 {
-		fmt.Fprintln(os.Stderr, fmt.Errorf("no maps found"))
+	mapsIdS := bpf.GetMapsIdsByName(BPFMapName)
+	if len(mapsIdS) == 0 {
+		fmt.Fprintln(os.Stderr, fmt.Errorf("no maps found for the %s map", BPFMapName))
+		os.Exit(-1)
+	}
+
+	bpfMapId := mapsIdS[0]
+
+	bpfMap, err := bpf.GetMapByID(bpfMapId)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, fmt.Errorf("the %s map with %d id not found: %w", BPFMapName, bpfMapId, err))
 		os.Exit(-1)
 	}
 
-	testMap := testMaps[0]
 	key1 := uint32(0)
 	value1 := uint32(55)
-	if err := testMap.Update(unsafe.Pointer(&key1), unsafe.Pointer(&value1)); err != nil {
+	if err := bpfMap.Update(unsafe.Pointer(&key1), unsafe.Pointer(&value1)); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(-1)
 	}