Internal change.

PiperOrigin-RevId: 361689477

2 files changed, 49 insertions, 4 deletions

diff --git a/runsc/fsgofer/fsgofer.go b/runsc/fsgofer/fsgofer.go
index cfa3796b1..1e80a634d 100644
--- a/runsc/fsgofer/fsgofer.go
+++ b/runsc/fsgofer/fsgofer.go
@@ -66,6 +66,9 @@ type Config struct {
 
 	// HostUDS signals whether the gofer can mount a host's UDS.
 	HostUDS bool
+
+	// enableXattr allows Get/SetXattr for the mounted file systems.
+	EnableXattr bool
 }
 
 type attachPoint struct {
@@ -795,12 +798,22 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
 	return err
 }
 
-func (*localFile) GetXattr(string, uint64) (string, error) {
-	return "", unix.EOPNOTSUPP
+func (l *localFile) GetXattr(name string, size uint64) (string, error) {
+	if !l.attachPoint.conf.EnableXattr {
+		return "", unix.EOPNOTSUPP
+	}
+	buffer := make([]byte, size)
+	if _, err := unix.Fgetxattr(l.file.FD(), name, buffer); err != nil {
+		return "", err
+	}
+	return string(buffer), nil
 }
 
-func (*localFile) SetXattr(string, string, uint32) error {
-	return unix.EOPNOTSUPP
+func (l *localFile) SetXattr(name string, value string, flags uint32) error {
+	if !l.attachPoint.conf.EnableXattr {
+		return unix.EOPNOTSUPP
+	}
+	return unix.Fsetxattr(l.file.FD(), name, []byte(value), int(flags))
 }
 
 func (*localFile) ListXattr(uint64) (map[string]struct{}, error) {
diff --git a/runsc/fsgofer/fsgofer_test.go b/runsc/fsgofer/fsgofer_test.go
index 99ea9bd32..a5f09f88f 100644
--- a/runsc/fsgofer/fsgofer_test.go
+++ b/runsc/fsgofer/fsgofer_test.go
@@ -565,6 +565,38 @@ func TestSetAttrOwner(t *testing.T) {
 	})
 }
 
+func SetGetXattr(l *localFile, name string, value string) error {
+	if err := l.SetXattr(name, value, 0 /* flags */); err != nil {
+		return err
+	}
+	ret, err := l.GetXattr(name, uint64(len(value)))
+	if err != nil {
+		return err
+	}
+	if ret != value {
+		return fmt.Errorf("Got value %s, want %s", ret, value)
+	}
+	return nil
+}
+
+func TestSetGetXattr(t *testing.T) {
+	xattrConfs := []Config{{ROMount: false, EnableXattr: false}, {ROMount: false, EnableXattr: true}}
+	runCustom(t, []uint32{unix.S_IFREG}, xattrConfs, func(t *testing.T, s state) {
+		name := "user.test"
+		value := "tmp"
+		err := SetGetXattr(s.file, name, value)
+		if s.conf.EnableXattr {
+			if err != nil {
+				t.Fatalf("%v: SetGetXattr failed, err: %v", s, err)
+			}
+		} else {
+			if err == nil {
+				t.Fatalf("%v: SetGetXattr should have failed", s)
+			}
+		}
+	})
+}
+
 func TestLink(t *testing.T) {
 	if !specutils.HasCapabilities(capability.CAP_DAC_READ_SEARCH) {
 		t.Skipf("Link test requires CAP_DAC_READ_SEARCH, running as %d", os.Getuid())