internal: export BPFMapCreate syscall wrapper

internal/syscall.go

@@ -178,3 +178,38 @@ func BPFObjGetInfoByFD(fd *FD, info unsafe.Pointer, size uintptr) error {
 	}
 	return nil
 }
+
+// BPFObjName is a null-terminated string made up of
+// 'A-Za-z0-9_' characters.
+type BPFObjName [unix.BPF_OBJ_NAME_LEN]byte
+
+// NewBPFObjName truncates the result if it is too long.
+func NewBPFObjName(name string) BPFObjName {
+	var result BPFObjName
+	copy(result[:unix.BPF_OBJ_NAME_LEN-1], name)
+	return result
+}
+
+type BPFMapCreateAttr struct {
+	MapType        uint32
+	KeySize        uint32
+	ValueSize      uint32
+	MaxEntries     uint32
+	Flags          uint32
+	InnerMapFd     uint32     // since 4.12 56f668dfe00d
+	NumaNode       uint32     // since 4.14 96eabe7a40aa
+	MapName        BPFObjName // since 4.15 ad5b177bd73f
+	MapIfIndex     uint32
+	BTFFd          uint32
+	BTFKeyTypeID   uint32
+	BTFValueTypeID uint32
+}
+
+func BPFMapCreate(attr *BPFMapCreateAttr) (*FD, error) {
+	fd, err := BPF(BPF_MAP_CREATE, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
+	if err != nil {
+		return nil, err
+	}
+
+	return NewFD(uint32(fd)), nil
+}

internal/syscall_test.go

@@ -0,0 +1,17 @@
+package internal
+
+import (
+	"testing"
+
+	"github.com/cilium/ebpf/internal/unix"
+)
+
+func TestObjName(t *testing.T) {
+	name := NewBPFObjName("more_than_16_characters_long")
+	if name[len(name)-1] != 0 {
+		t.Error("NewBPFObjName doesn't null terminate")
+	}
+	if len(name) != unix.BPF_OBJ_NAME_LEN {
+		t.Errorf("Name is %d instead of %d bytes long", len(name), unix.BPF_OBJ_NAME_LEN)
+	}
+}

map.go

@@ -317,25 +317,25 @@ func createMap(spec *MapSpec, inner *internal.FD, opts MapOptions, handles *hand
 		}
 	}
 
-	attr := bpfMapCreateAttr{
-		mapType:    spec.Type,
-		keySize:    spec.KeySize,
-		valueSize:  spec.ValueSize,
-		maxEntries: spec.MaxEntries,
-		flags:      spec.Flags,
-		numaNode:   spec.NumaNode,
+	attr := internal.BPFMapCreateAttr{
+		MapType:    uint32(spec.Type),
+		KeySize:    spec.KeySize,
+		ValueSize:  spec.ValueSize,
+		MaxEntries: spec.MaxEntries,
+		Flags:      spec.Flags,
+		NumaNode:   spec.NumaNode,
 	}
 
 	if inner != nil {
 		var err error
-		attr.innerMapFd, err = inner.Value()
+		attr.InnerMapFd, err = inner.Value()
 		if err != nil {
 			return nil, fmt.Errorf("map create: %w", err)
 		}
 	}
 
 	if haveObjName() == nil {
-		attr.mapName = newBPFObjName(spec.Name)
+		attr.MapName = internal.NewBPFObjName(spec.Name)
 	}
 
 	var btfDisabled bool
@@ -347,13 +347,13 @@ func createMap(spec *MapSpec, inner *internal.FD, opts MapOptions, handles *hand
 		}
 
 		if handle != nil {
-			attr.btfFd = uint32(handle.FD())
-			attr.btfKeyTypeID = btf.MapKey(spec.BTF).ID()
-			attr.btfValueTypeID = btf.MapValue(spec.BTF).ID()
+			attr.BTFFd = uint32(handle.FD())
+			attr.BTFKeyTypeID = uint32(btf.MapKey(spec.BTF).ID())
+			attr.BTFValueTypeID = uint32(btf.MapValue(spec.BTF).ID())
 		}
 	}
 
-	fd, err := bpfMapCreate(&attr)
+	fd, err := internal.BPFMapCreate(&attr)
 	if err != nil {
 		if errors.Is(err, unix.EPERM) {
 			return nil, fmt.Errorf("map create: RLIMIT_MEMLOCK may be too low: %w", err)

prog.go

@@ -175,7 +175,7 @@ func newProgramWithOptions(spec *ProgramSpec, opts ProgramOptions, handles *hand
 	}
 
 	if haveObjName() == nil {
-		attr.progName = newBPFObjName(spec.Name)
+		attr.progName = internal.NewBPFObjName(spec.Name)
 	}
 
 	var err error

syscalls.go

@@ -13,17 +13,6 @@ import (
 // Generic errors returned by BPF syscalls.
 var ErrNotExist = errors.New("requested object does not exist")
 
-// bpfObjName is a null-terminated string made up of
-// 'A-Za-z0-9_' characters.
-type bpfObjName [unix.BPF_OBJ_NAME_LEN]byte
-
-// newBPFObjName truncates the result if it is too long.
-func newBPFObjName(name string) bpfObjName {
-	var result bpfObjName
-	copy(result[:unix.BPF_OBJ_NAME_LEN-1], name)
-	return result
-}
-
 // invalidBPFObjNameChar returns true if char may not appear in
 // a BPF object name.
 func invalidBPFObjNameChar(char rune) bool {
@@ -45,21 +34,6 @@ func invalidBPFObjNameChar(char rune) bool {
 	}
 }
 
-type bpfMapCreateAttr struct {
-	mapType        MapType
-	keySize        uint32
-	valueSize      uint32
-	maxEntries     uint32
-	flags          uint32
-	innerMapFd     uint32     // since 4.12 56f668dfe00d
-	numaNode       uint32     // since 4.14 96eabe7a40aa
-	mapName        bpfObjName // since 4.15 ad5b177bd73f
-	mapIfIndex     uint32
-	btfFd          uint32
-	btfKeyTypeID   btf.TypeID
-	btfValueTypeID btf.TypeID
-}
-
 type bpfMapOpAttr struct {
 	mapFd   uint32
 	padding uint32
@@ -86,10 +60,10 @@ type bpfMapInfo struct {
 	value_size                uint32
 	max_entries               uint32
 	map_flags                 uint32
-	name                      bpfObjName // since 4.15 ad5b177bd73f
-	ifindex                   uint32     // since 4.16 52775b33bb50
-	btf_vmlinux_value_type_id uint32     // since 5.6  85d33df357b6
-	netns_dev                 uint64     // since 4.16 52775b33bb50
+	name                      internal.BPFObjName // since 4.15 ad5b177bd73f
+	ifindex                   uint32              // since 4.16 52775b33bb50
+	btf_vmlinux_value_type_id uint32              // since 5.6  85d33df357b6
+	netns_dev                 uint64              // since 4.16 52775b33bb50
 	netns_ino                 uint64
 	btf_id                    uint32 // since 4.18 78958fca7ead
 	btf_key_type_id           uint32 // since 4.18 9b2cf328b2ec
@@ -104,11 +78,11 @@ type bpfProgLoadAttr struct {
 	logLevel           uint32
 	logSize            uint32
 	logBuf             internal.Pointer
-	kernelVersion      uint32     // since 4.1  2541517c32be
-	progFlags          uint32     // since 4.11 e07b98d9bffe
-	progName           bpfObjName // since 4.15 067cae47771c
-	progIfIndex        uint32     // since 4.15 1f6f4cb7ba21
-	expectedAttachType AttachType // since 4.17 5e43f899b03a
+	kernelVersion      uint32              // since 4.1  2541517c32be
+	progFlags          uint32              // since 4.11 e07b98d9bffe
+	progName           internal.BPFObjName // since 4.15 067cae47771c
+	progIfIndex        uint32              // since 4.15 1f6f4cb7ba21
+	expectedAttachType AttachType          // since 4.17 5e43f899b03a
 	progBTFFd          uint32
 	funcInfoRecSize    uint32
 	funcInfo           internal.Pointer
@@ -132,7 +106,7 @@ type bpfProgInfo struct {
 	created_by_uid           uint32
 	nr_map_ids               uint32
 	map_ids                  internal.Pointer
-	name                     bpfObjName // since 4.15 067cae47771c
+	name                     internal.BPFObjName // since 4.15 067cae47771c
 	ifindex                  uint32
 	gpl_compatible           uint32
 	netns_dev                uint64
@@ -205,23 +179,14 @@ func bpfProgTestRun(attr *bpfProgTestRunAttr) error {
 	return err
 }
 
-func bpfMapCreate(attr *bpfMapCreateAttr) (*internal.FD, error) {
-	fd, err := internal.BPF(internal.BPF_MAP_CREATE, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
-	if err != nil {
-		return nil, err
-	}
-
-	return internal.NewFD(uint32(fd)), nil
-}
-
 var haveNestedMaps = internal.FeatureTest("nested maps", "4.12", func() error {
-	_, err := bpfMapCreate(&bpfMapCreateAttr{
-		mapType:    ArrayOfMaps,
-		keySize:    4,
-		valueSize:  4,
-		maxEntries: 1,
+	_, err := internal.BPFMapCreate(&internal.BPFMapCreateAttr{
+		MapType:    uint32(ArrayOfMaps),
+		KeySize:    4,
+		ValueSize:  4,
+		MaxEntries: 1,
 		// Invalid file descriptor.
-		innerMapFd: ^uint32(0),
+		InnerMapFd: ^uint32(0),
 	})
 	if errors.Is(err, unix.EINVAL) {
 		return internal.ErrNotSupported
@@ -235,12 +200,12 @@ var haveNestedMaps = internal.FeatureTest("nested maps", "4.12", func() error {
 var haveMapMutabilityModifiers = internal.FeatureTest("read- and write-only maps", "5.2", func() error {
 	// This checks BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG. Since
 	// BPF_MAP_FREEZE appeared in 5.2 as well we don't do a separate check.
-	m, err := bpfMapCreate(&bpfMapCreateAttr{
-		mapType:    Array,
-		keySize:    4,
-		valueSize:  4,
-		maxEntries: 1,
-		flags:      unix.BPF_F_RDONLY_PROG,
+	m, err := internal.BPFMapCreate(&internal.BPFMapCreateAttr{
+		MapType:    uint32(Array),
+		KeySize:    4,
+		ValueSize:  4,
+		MaxEntries: 1,
+		Flags:      unix.BPF_F_RDONLY_PROG,
 	})
 	if err != nil {
 		return internal.ErrNotSupported
@@ -417,15 +382,15 @@ func bpfGetMapInfoByFD(fd *internal.FD) (*bpfMapInfo, error) {
 }
 
 var haveObjName = internal.FeatureTest("object names", "4.15", func() error {
-	attr := bpfMapCreateAttr{
-		mapType:    Array,
-		keySize:    4,
-		valueSize:  4,
-		maxEntries: 1,
-		mapName:    newBPFObjName("feature_test"),
+	attr := internal.BPFMapCreateAttr{
+		MapType:    uint32(Array),
+		KeySize:    4,
+		ValueSize:  4,
+		MaxEntries: 1,
+		MapName:    internal.NewBPFObjName("feature_test"),
 	}
 
-	fd, err := bpfMapCreate(&attr)
+	fd, err := internal.BPFMapCreate(&attr)
 	if err != nil {
 		return internal.ErrNotSupported
 	}
@@ -439,15 +404,15 @@ var objNameAllowsDot = internal.FeatureTest("dot in object names", "5.2", func()
 		return err
 	}
 
-	attr := bpfMapCreateAttr{
-		mapType:    Array,
-		keySize:    4,
-		valueSize:  4,
-		maxEntries: 1,
-		mapName:    newBPFObjName(".test"),
+	attr := internal.BPFMapCreateAttr{
+		MapType:    uint32(Array),
+		KeySize:    4,
+		ValueSize:  4,
+		MaxEntries: 1,
+		MapName:    internal.NewBPFObjName(".test"),
 	}
 
-	fd, err := bpfMapCreate(&attr)
+	fd, err := internal.BPFMapCreate(&attr)
 	if err != nil {
 		return internal.ErrNotSupported
 	}
@@ -458,14 +423,14 @@ var objNameAllowsDot = internal.FeatureTest("dot in object names", "5.2", func()
 
 var haveBatchAPI = internal.FeatureTest("map batch api", "5.6", func() error {
 	var maxEntries uint32 = 2
-	attr := bpfMapCreateAttr{
-		mapType:    Hash,
-		keySize:    4,
-		valueSize:  4,
-		maxEntries: maxEntries,
+	attr := internal.BPFMapCreateAttr{
+		MapType:    uint32(Hash),
+		KeySize:    4,
+		ValueSize:  4,
+		MaxEntries: maxEntries,
 	}
 
-	fd, err := bpfMapCreate(&attr)
+	fd, err := internal.BPFMapCreate(&attr)
 	if err != nil {
 		return internal.ErrNotSupported
 	}

syscalls_test.go

@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	"github.com/cilium/ebpf/internal/testutils"
-	"github.com/cilium/ebpf/internal/unix"
 )
 
 func TestObjNameCharacters(t *testing.T) {
@@ -24,16 +23,6 @@ func TestObjNameCharacters(t *testing.T) {
 	}
 }
 
-func TestObjName(t *testing.T) {
-	name := newBPFObjName("more_than_16_characters_long")
-	if name[len(name)-1] != 0 {
-		t.Error("newBPFObjName doesn't null terminate")
-	}
-	if len(name) != unix.BPF_OBJ_NAME_LEN {
-		t.Errorf("Name is %d instead of %d bytes long", len(name), unix.BPF_OBJ_NAME_LEN)
-	}
-}
-
 func TestHaveBatchAPI(t *testing.T) {
 	testutils.CheckFeatureTest(t, haveBatchAPI)
 }