231 lines
7.0 KiB
Go
231 lines
7.0 KiB
Go
package pathfs_frontend
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import (
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"fmt"
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"os"
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"path/filepath"
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"time"
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"github.com/hanwen/go-fuse/fuse"
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"github.com/hanwen/go-fuse/fuse/nodefs"
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"github.com/hanwen/go-fuse/fuse/pathfs"
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"github.com/rfjakob/gocryptfs/cryptfs"
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)
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type FS struct {
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*cryptfs.CryptFS
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pathfs.FileSystem // loopbackFileSystem
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backing string // Backing directory
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}
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// Encrypted FUSE overlay filesystem
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func NewFS(key []byte, backing string, useOpenssl bool, plaintextNames bool) *FS {
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return &FS{
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CryptFS: cryptfs.NewCryptFS(key, useOpenssl, plaintextNames),
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FileSystem: pathfs.NewLoopbackFileSystem(backing),
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backing: backing,
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}
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}
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// GetPath - get the absolute path of the backing file
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func (fs *FS) GetPath(relPath string) string {
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return filepath.Join(fs.backing, fs.EncryptPath(relPath))
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}
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func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) {
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cryptfs.Debug.Printf("FS.GetAttr('%s')\n", name)
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if fs.CryptFS.IsFiltered(name) {
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return nil, fuse.EPERM
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}
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cName := fs.EncryptPath(name)
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a, status := fs.FileSystem.GetAttr(cName, context)
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if a == nil {
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cryptfs.Debug.Printf("FS.GetAttr failed: %s\n", status.String())
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return a, status
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}
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if a.IsRegular() {
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a.Size = fs.CipherSizeToPlainSize(a.Size)
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} else if a.IsSymlink() {
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target, _ := fs.Readlink(name, context)
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a.Size = uint64(len(target))
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}
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return a, status
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}
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func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) {
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cryptfs.Debug.Printf("OpenDir(%s)\n", dirName)
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cipherEntries, status := fs.FileSystem.OpenDir(fs.EncryptPath(dirName), context)
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var plain []fuse.DirEntry
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if cipherEntries != nil {
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for i := range cipherEntries {
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cName := cipherEntries[i].Name
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if dirName == "" && cName == cryptfs.ConfDefaultName {
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// silently ignore "gocryptfs.conf" in the top level dir
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continue
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}
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name, err := fs.DecryptPath(cName)
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if err != nil {
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fmt.Printf("Invalid name \"%s\" in dir \"%s\": %s\n", cName, name, err)
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continue
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}
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cipherEntries[i].Name = name
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plain = append(plain, cipherEntries[i])
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}
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}
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return plain, status
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}
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// We always need read access to do read-modify-write cycles
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func (fs *FS) mangleOpenFlags(flags uint32) (newFlags int, writeOnly bool) {
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newFlags = int(flags)
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if newFlags&os.O_WRONLY > 0 {
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writeOnly = true
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newFlags = newFlags ^ os.O_WRONLY | os.O_RDWR
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}
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// We also cannot open the file in append mode, we need to seek back for RMW
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newFlags = newFlags &^ os.O_APPEND
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return newFlags, writeOnly
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}
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func (fs *FS) Open(path string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) {
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cryptfs.Debug.Printf("Open(%s)\n", path)
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if fs.CryptFS.IsFiltered(path){
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return nil, fuse.EPERM
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}
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iflags, writeOnly := fs.mangleOpenFlags(flags)
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f, err := os.OpenFile(fs.GetPath(path), iflags, 0666)
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if err != nil {
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return nil, fuse.ToStatus(err)
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}
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return NewFile(f, writeOnly, fs.CryptFS), fuse.OK
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}
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func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Context) (fuseFile nodefs.File, code fuse.Status) {
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if fs.CryptFS.IsFiltered(path){
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return nil, fuse.EPERM
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}
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iflags, writeOnly := fs.mangleOpenFlags(flags)
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f, err := os.OpenFile(fs.GetPath(path), iflags|os.O_CREATE, os.FileMode(mode))
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if err != nil {
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return nil, fuse.ToStatus(err)
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}
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return NewFile(f, writeOnly, fs.CryptFS), fuse.OK
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}
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func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(path){
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return fuse.EPERM
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}
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return fs.FileSystem.Chmod(fs.EncryptPath(path), mode, context)
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}
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func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(path){
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return fuse.EPERM
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}
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return fs.FileSystem.Chown(fs.EncryptPath(path), uid, gid, context)
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}
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func (fs *FS) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(name){
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return fuse.EPERM
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}
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return fs.FileSystem.Mknod(fs.EncryptPath(name), mode, dev, context)
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}
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func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code fuse.Status) {
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cryptfs.Warn.Printf("Truncate of a closed file is not supported, returning ENOSYS\n")
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return fuse.ENOSYS
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}
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func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(path){
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return fuse.EPERM
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}
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return fs.FileSystem.Utimens(fs.EncryptPath(path), Atime, Mtime, context)
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}
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func (fs *FS) Readlink(name string, context *fuse.Context) (out string, status fuse.Status) {
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dst, status := fs.FileSystem.Readlink(fs.EncryptPath(name), context)
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if status != fuse.OK {
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return "", status
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}
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dstPlain, err := fs.DecryptPath(dst)
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if err != nil {
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cryptfs.Warn.Printf("Failed decrypting symlink: %s\n", err.Error())
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return "", fuse.EIO
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}
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return dstPlain, status
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}
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func (fs *FS) Mkdir(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(path){
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return fuse.EPERM
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}
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return fs.FileSystem.Mkdir(fs.EncryptPath(path), mode, context)
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}
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func (fs *FS) Unlink(name string, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(name){
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return fuse.EPERM
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}
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cName := fs.EncryptPath(name)
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code = fs.FileSystem.Unlink(cName, context)
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if code != fuse.OK {
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cryptfs.Warn.Printf("Unlink failed on %s [%s], code=%s\n", name, cName, code.String())
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}
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return code
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}
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func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
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return fs.FileSystem.Rmdir(fs.EncryptPath(name), context)
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}
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func (fs *FS) Symlink(pointedTo string, linkName string, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(linkName){
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return fuse.EPERM
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}
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// TODO symlink encryption
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cryptfs.Debug.Printf("Symlink(\"%s\", \"%s\")\n", pointedTo, linkName)
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return fs.FileSystem.Symlink(fs.EncryptPath(pointedTo), fs.EncryptPath(linkName), context)
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}
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func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(newPath){
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return fuse.EPERM
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}
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return fs.FileSystem.Rename(fs.EncryptPath(oldPath), fs.EncryptPath(newPath), context)
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}
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func (fs *FS) Link(orig string, newName string, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(newName){
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return fuse.EPERM
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}
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return fs.FileSystem.Link(fs.EncryptPath(orig), fs.EncryptPath(newName), context)
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}
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func (fs *FS) Access(name string, mode uint32, context *fuse.Context) (code fuse.Status) {
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if fs.CryptFS.IsFiltered(name){
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return fuse.EPERM
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}
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return fs.FileSystem.Access(fs.EncryptPath(name), mode, context)
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}
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func (fs *FS) GetXAttr(name string, attr string, context *fuse.Context) ([]byte, fuse.Status) {
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return nil, fuse.ENOSYS
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}
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func (fs *FS) SetXAttr(name string, attr string, data []byte, flags int, context *fuse.Context) fuse.Status {
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return fuse.ENOSYS
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}
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func (fs *FS) ListXAttr(name string, context *fuse.Context) ([]string, fuse.Status) {
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return nil, fuse.ENOSYS
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}
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func (fs *FS) RemoveXAttr(name string, attr string, context *fuse.Context) fuse.Status {
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return fuse.ENOSYS
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}
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