Merge pull request #766 from jgfrm/nissue25

Add support for extended attributes (e.g. ACL)

Closes #766

src/restic/archiver/archiver.go

@@ -385,7 +385,7 @@ func (arch *Archiver) dirWorker(wg *sync.WaitGroup, p *restic.Progress, done <-c
 			node := &restic.Node{}
 
 			if dir.Path() != "" && dir.Info() != nil {
-				n, err := restic.NodeFromFileInfo(dir.Path(), dir.Info())
+				n, err := restic.NodeFromFileInfo(dir.Fullpath(), dir.Info())
 				if err != nil {
 					n.Error = err.Error()
 					dir.Result() <- n

src/restic/fuse/dir.go

@@ -177,3 +177,21 @@ func (d *dir) Lookup(ctx context.Context, name string) (fs.Node, error) {
 		return nil, fuse.ENOENT
 	}
 }
+
+func (d *dir) Listxattr(ctx context.Context, req *fuse.ListxattrRequest, resp *fuse.ListxattrResponse) error {
+	debug.Log("Listxattr(%v, %v)", d.node.Name, req.Size)
+	for _, attr := range d.node.ExtendedAttributes {
+		resp.Append(attr.Name)
+	}
+	return nil
+}
+
+func (d *dir) Getxattr(ctx context.Context, req *fuse.GetxattrRequest, resp *fuse.GetxattrResponse) error {
+	debug.Log("Getxattr(%v, %v, %v)", d.node.Name, req.Name, req.Size)
+	attrval := d.node.GetExtendedAttribute(req.Name)
+	if attrval != nil {
+		resp.Xattr = attrval
+		return nil
+	}
+	return fuse.ErrNoXattr
+}

src/restic/fuse/file.go

@@ -164,3 +164,21 @@ func (f *file) Release(ctx context.Context, req *fuse.ReleaseRequest) error {
 	}
 	return nil
 }
+
+func (f *file) Listxattr(ctx context.Context, req *fuse.ListxattrRequest, resp *fuse.ListxattrResponse) error {
+	debug.Log("Listxattr(%v, %v)", f.node.Name, req.Size)
+	for _, attr := range f.node.ExtendedAttributes {
+		resp.Append(attr.Name)
+	}
+	return nil
+}
+
+func (f *file) Getxattr(ctx context.Context, req *fuse.GetxattrRequest, resp *fuse.GetxattrResponse) error {
+	debug.Log("Getxattr(%v, %v, %v)", f.node.Name, req.Name, req.Size)
+	attrval := f.node.GetExtendedAttribute(req.Name)
+	if attrval != nil {
+		resp.Xattr = attrval
+		return nil
+	}
+	return fuse.ErrNoXattr
+}

src/restic/node.go

@@ -12,31 +12,38 @@ import (
 
 	"restic/errors"
 
-	"runtime"
-
+	"bytes"
 	"restic/debug"
 	"restic/fs"
+	"runtime"
 )
 
+// ExtendedAttribute is a tuple storing the xattr name and value.
+type ExtendedAttribute struct {
+	Name  string `json:"name"`
+	Value []byte `json:"value"`
+}
+
 // Node is a file, directory or other item in a backup.
 type Node struct {
-	Name       string      `json:"name"`
-	Type       string      `json:"type"`
-	Mode       os.FileMode `json:"mode,omitempty"`
-	ModTime    time.Time   `json:"mtime,omitempty"`
-	AccessTime time.Time   `json:"atime,omitempty"`
-	ChangeTime time.Time   `json:"ctime,omitempty"`
-	UID        uint32      `json:"uid"`
-	GID        uint32      `json:"gid"`
-	User       string      `json:"user,omitempty"`
-	Group      string      `json:"group,omitempty"`
-	Inode      uint64      `json:"inode,omitempty"`
-	Size       uint64      `json:"size,omitempty"`
-	Links      uint64      `json:"links,omitempty"`
-	LinkTarget string      `json:"linktarget,omitempty"`
-	Device     uint64      `json:"device,omitempty"`
-	Content    IDs         `json:"content"`
-	Subtree    *ID         `json:"subtree,omitempty"`
+	Name               string              `json:"name"`
+	Type               string              `json:"type"`
+	Mode               os.FileMode         `json:"mode,omitempty"`
+	ModTime            time.Time           `json:"mtime,omitempty"`
+	AccessTime         time.Time           `json:"atime,omitempty"`
+	ChangeTime         time.Time           `json:"ctime,omitempty"`
+	UID                uint32              `json:"uid"`
+	GID                uint32              `json:"gid"`
+	User               string              `json:"user,omitempty"`
+	Group              string              `json:"group,omitempty"`
+	Inode              uint64              `json:"inode,omitempty"`
+	Size               uint64              `json:"size,omitempty"`
+	Links              uint64              `json:"links,omitempty"`
+	LinkTarget         string              `json:"linktarget,omitempty"`
+	ExtendedAttributes []ExtendedAttribute `json:"extended_attributes,omitempty"`
+	Device             uint64              `json:"device,omitempty"`
+	Content            IDs                 `json:"content"`
+	Subtree            *ID                 `json:"subtree,omitempty"`
 
 	Error string `json:"error,omitempty"`
 
@@ -96,6 +103,16 @@ func nodeTypeFromFileInfo(fi os.FileInfo) string {
 	return ""
 }
 
+// GetExtendedAttribute gets the extended attribute.
+func (node Node) GetExtendedAttribute(a string) []byte {
+	for _, attr := range node.ExtendedAttributes {
+		if attr.Name == a {
+			return attr.Value
+		}
+	}
+	return nil
+}
+
 // CreateAt creates the node at the given path and restores all the meta data.
 func (node *Node) CreateAt(path string, repo Repository, idx *HardlinkIndex) error {
 	debug.Log("create node %v at %v", node.Name, path)
@@ -162,6 +179,22 @@ func (node Node) restoreMetadata(path string) error {
 		}
 	}
 
+	err = node.restoreExtendedAttributes(path)
+	if err != nil {
+		debug.Log("error restoring extended attributes for %v: %v", path, err)
+		return err
+	}
+
+	return nil
+}
+
+func (node Node) restoreExtendedAttributes(path string) error {
+	for _, attr := range node.ExtendedAttributes {
+		err := Setxattr(path, attr.Name, attr.Value)
+		if err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
@@ -350,6 +383,9 @@ func (node Node) Equals(other Node) bool {
 	if !node.sameContent(other) {
 		return false
 	}
+	if !node.sameExtendedAttributes(other) {
+		return false
+	}
 	if node.Subtree != nil {
 		if other.Subtree == nil {
 			return false
@@ -388,6 +424,51 @@ func (node Node) sameContent(other Node) bool {
 			return false
 		}
 	}
+	return true
+}
+
+func (node Node) sameExtendedAttributes(other Node) bool {
+	if len(node.ExtendedAttributes) != len(other.ExtendedAttributes) {
+		return false
+	}
+
+	// build a set of all attributes that node has
+	type mapvalue struct {
+		value   []byte
+		present bool
+	}
+	attributes := make(map[string]mapvalue)
+	for _, attr := range node.ExtendedAttributes {
+		attributes[attr.Name] = mapvalue{value: attr.Value}
+	}
+
+	for _, attr := range other.ExtendedAttributes {
+		v, ok := attributes[attr.Name]
+		if !ok {
+			// extended attribute is not set for node
+			debug.Log("other node has attribute %v, which is not present in node", attr.Name)
+			return false
+
+		}
+
+		if !bytes.Equal(v.value, attr.Value) {
+			// attribute has different value
+			debug.Log("attribute %v has different value", attr.Name)
+			return false
+		}
+
+		// remember that this attribute is present in other.
+		v.present = true
+		attributes[attr.Name] = v
+	}
+
+	// check for attributes that are not present in other
+	for name, v := range attributes {
+		if !v.present {
+			debug.Log("attribute %v not present in other node", name)
+			return false
+		}
+	}
 
 	return true
 }
@@ -497,6 +578,9 @@ func (node *Node) fillExtra(path string, fi os.FileInfo) error {
 		node.LinkTarget, err = fs.Readlink(path)
 		node.Links = uint64(stat.nlink())
 		err = errors.Wrap(err, "Readlink")
+		if err != nil {
+			return err
+		}
 	case "dev":
 		node.Device = uint64(stat.rdev())
 		node.Links = uint64(stat.nlink())
@@ -506,9 +590,32 @@ func (node *Node) fillExtra(path string, fi os.FileInfo) error {
 	case "fifo":
 	case "socket":
 	default:
-		err = errors.Errorf("invalid node type %q", node.Type)
+		return errors.Errorf("invalid node type %q", node.Type)
 	}
 
+	if err = node.fillExtendedAttributes(path); err != nil {
+		return err
+	}
+
+	return err
+}
+
+func (node *Node) fillExtendedAttributes(path string) error {
+	if node.Type == "symlink" {
+		return nil
+	}
+	xattrs, err := Listxattr(path)
+	if err == nil {
+		node.ExtendedAttributes = make([]ExtendedAttribute, len(xattrs))
+		for i, attr := range xattrs {
+			attrVal, err := Getxattr(path, attr)
+			if err != nil {
+				return errors.Errorf("can not obtain extended attribute %v for %v:\n", attr, path)
+			}
+			node.ExtendedAttributes[i].Name = attr
+			node.ExtendedAttributes[i].Value = attrVal
+		}
+	}
 	return err
 }
 

src/restic/node_freebsd.go

@@ -9,3 +9,19 @@ func (node Node) restoreSymlinkTimestamps(path string, utimes [2]syscall.Timespe
 func (s statUnix) atim() syscall.Timespec { return s.Atimespec }
 func (s statUnix) mtim() syscall.Timespec { return s.Mtimespec }
 func (s statUnix) ctim() syscall.Timespec { return s.Ctimespec }
+
+// Getxattr retrieves extended attribute data associated with path.
+func Getxattr(path, name string) ([]byte, error) {
+	return nil, nil
+}
+
+// Listxattr retrieves a list of names of extended attributes associated with the
+// given path in the file system.
+func Listxattr(path string) ([]string, error) {
+	return nil, nil
+}
+
+// Setxattr associates name and data together as an attribute of path.
+func Setxattr(path, name string, data []byte) error {
+	return nil
+}

src/restic/node_openbsd.go

@@ -9,3 +9,19 @@ func (node Node) restoreSymlinkTimestamps(path string, utimes [2]syscall.Timespe
 func (s statUnix) atim() syscall.Timespec { return s.Atim }
 func (s statUnix) mtim() syscall.Timespec { return s.Mtim }
 func (s statUnix) ctim() syscall.Timespec { return s.Ctim }
+
+// Getxattr retrieves extended attribute data associated with path.
+func Getxattr(path, name string) ([]byte, error) {
+	return nil, nil
+}
+
+// Listxattr retrieves a list of names of extended attributes associated with the
+// given path in the file system.
+func Listxattr(path string) ([]string, error) {
+	return nil, nil
+}
+
+// Setxattr associates name and data together as an attribute of path.
+func Setxattr(path, name string, data []byte) error {
+	return nil
+}

src/restic/node_windows.go

@@ -22,6 +22,22 @@ func (node Node) restoreSymlinkTimestamps(path string, utimes [2]syscall.Timespe
 	return nil
 }
 
+// Getxattr retrieves extended attribute data associated with path.
+func Getxattr(path, name string) ([]byte, error) {
+	return nil, nil
+}
+
+// Listxattr retrieves a list of names of extended attributes associated with the
+// given path in the file system.
+func Listxattr(path string) ([]string, error) {
+	return nil, nil
+}
+
+// Setxattr associates name and data together as an attribute of path.
+func Setxattr(path, name string, data []byte) error {
+	return nil
+}
+
 type statWin syscall.Win32FileAttributeData
 
 //ToStatT call the Windows system call Win32FileAttributeData.

src/restic/node_xattr.go

@@ -0,0 +1,38 @@
+// +build !openbsd
+// +build !windows
+// +build !freebsd
+
+package restic
+
+import (
+	"github.com/ivaxer/go-xattr"
+	"syscall"
+)
+
+// Getxattr retrieves extended attribute data associated with path.
+func Getxattr(path, name string) ([]byte, error) {
+	b, e := xattr.Get(path, name)
+	if e == syscall.ENOTSUP {
+		return nil, nil
+	}
+	return b, e
+}
+
+// Listxattr retrieves a list of names of extended attributes associated with the
+// given path in the file system.
+func Listxattr(path string) ([]string, error) {
+	s, e := xattr.List(path)
+	if e == syscall.ENOTSUP {
+		return nil, nil
+	}
+	return s, e
+}
+
+// Setxattr associates name and data together as an attribute of path.
+func Setxattr(path, name string, data []byte) error {
+	e := xattr.Set(path, name, data)
+	if e == syscall.ENOTSUP {
+		return nil
+	}
+	return e
+}

src/restic/tree_test.go

@@ -82,7 +82,7 @@ func TestNodeComparison(t *testing.T) {
 	fi, err := os.Lstat("tree_test.go")
 	OK(t, err)
 
-	node, err := restic.NodeFromFileInfo("foo", fi)
+	node, err := restic.NodeFromFileInfo("tree_test.go", fi)
 	OK(t, err)
 
 	n2 := *node

vendor/manifest

@@ -19,6 +19,12 @@
 			"revision": "76626ae9c91c4f2a10f34cad8ce83ea42c93bb75",
 			"branch": "master"
 		},
+		{
+			"importpath": "github.com/ivaxer/go-xattr",
+			"repository": "https://github.com/ivaxer/go-xattr",
+			"revision": "1a541654d8e447148cf23d472c948f9f0078ac50",
+			"branch": "master"
+		},
 		{
 			"importpath": "github.com/kr/fs",
 			"repository": "https://github.com/kr/fs",