diff options
Diffstat (limited to 'internal/fusefrontend/fs_dir.go')
| -rw-r--r-- | internal/fusefrontend/fs_dir.go | 343 |
1 files changed, 0 insertions, 343 deletions
diff --git a/internal/fusefrontend/fs_dir.go b/internal/fusefrontend/fs_dir.go deleted file mode 100644 index 0d8adae..0000000 --- a/internal/fusefrontend/fs_dir.go +++ /dev/null @@ -1,343 +0,0 @@ -package fusefrontend - -// Mkdir and Rmdir - -import ( - "fmt" - "io" - "runtime" - "syscall" - - "golang.org/x/sys/unix" - - "github.com/hanwen/go-fuse/v2/fuse" - - "github.com/rfjakob/gocryptfs/internal/configfile" - "github.com/rfjakob/gocryptfs/internal/cryptocore" - "github.com/rfjakob/gocryptfs/internal/nametransform" - "github.com/rfjakob/gocryptfs/internal/syscallcompat" - "github.com/rfjakob/gocryptfs/internal/tlog" -) - -const dsStoreName = ".DS_Store" - -// mkdirWithIv - create a new directory and corresponding diriv file. dirfd -// should be a handle to the parent directory, cName is the name of the new -// directory and mode specifies the access permissions to use. -func (fs *FS) mkdirWithIv(dirfd int, cName string, mode uint32, context *fuse.Context) error { - // Between the creation of the directory and the creation of gocryptfs.diriv - // the directory is inconsistent. Take the lock to prevent other readers - // from seeing it. - fs.dirIVLock.Lock() - defer fs.dirIVLock.Unlock() - err := syscallcompat.MkdiratUser(dirfd, cName, mode, &context.Caller) - if err != nil { - return err - } - dirfd2, err := syscallcompat.Openat(dirfd, cName, syscall.O_DIRECTORY|syscall.O_NOFOLLOW|syscallcompat.O_PATH, 0) - if err == nil { - // Create gocryptfs.diriv - err = nametransform.WriteDirIVAt(dirfd2) - syscall.Close(dirfd2) - } - if err != nil { - // Delete inconsistent directory (missing gocryptfs.diriv!) - err2 := syscallcompat.Unlinkat(dirfd, cName, unix.AT_REMOVEDIR) - if err2 != nil { - tlog.Warn.Printf("mkdirWithIv: rollback failed: %v", err2) - } - } - return err -} - -// Mkdir - FUSE call. Create a directory at "newPath" with permissions "mode". -// -// Symlink-safe through use of Mkdirat(). -func (fs *FS) Mkdir(newPath string, mode uint32, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(newPath) { - return fuse.EPERM - } - dirfd, cName, err := fs.openBackingDir(newPath) - if err != nil { - return fuse.ToStatus(err) - } - defer syscall.Close(dirfd) - // Make sure context is nil if we don't want to preserve the owner - if !fs.args.PreserveOwner { - context = nil - } - if fs.args.PlaintextNames { - err = syscallcompat.MkdiratUser(dirfd, cName, mode, &context.Caller) - return fuse.ToStatus(err) - } - - // We need write and execute permissions to create gocryptfs.diriv. - // Also, we need read permissions to open the directory (to avoid - // race-conditions between getting and setting the mode). - origMode := mode - mode = mode | 0700 - - // Handle long file name - if nametransform.IsLongContent(cName) { - // Create ".name" - err = fs.nameTransform.WriteLongNameAt(dirfd, cName, newPath) - if err != nil { - return fuse.ToStatus(err) - } - - // Create directory - err = fs.mkdirWithIv(dirfd, cName, mode, context) - if err != nil { - nametransform.DeleteLongNameAt(dirfd, cName) - return fuse.ToStatus(err) - } - } else { - err = fs.mkdirWithIv(dirfd, cName, mode, context) - if err != nil { - return fuse.ToStatus(err) - } - } - // Set mode - if origMode != mode { - dirfd2, err := syscallcompat.Openat(dirfd, cName, - syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NOFOLLOW, 0) - if err != nil { - tlog.Warn.Printf("Mkdir %q: Openat failed: %v", cName, err) - return fuse.ToStatus(err) - } - defer syscall.Close(dirfd2) - - var st syscall.Stat_t - err = syscall.Fstat(dirfd2, &st) - if err != nil { - tlog.Warn.Printf("Mkdir %q: Fstat failed: %v", cName, err) - return fuse.ToStatus(err) - } - - // Preserve SGID bit if it was set due to inheritance. - origMode = uint32(st.Mode&^0777) | origMode - err = syscall.Fchmod(dirfd2, origMode) - if err != nil { - tlog.Warn.Printf("Mkdir %q: Fchmod %#o -> %#o failed: %v", cName, mode, origMode, err) - return fuse.ToStatus(err) - } - } - return fuse.OK -} - -// haveDsstore return true if one of the entries in "names" is ".DS_Store". -func haveDsstore(entries []fuse.DirEntry) bool { - for _, e := range entries { - if e.Name == dsStoreName { - return true - } - } - return false -} - -// Rmdir - FUSE call. -// -// Symlink-safe through Unlinkat() + AT_REMOVEDIR. -func (fs *FS) Rmdir(relPath string, context *fuse.Context) (code fuse.Status) { - defer fs.dirCache.Clear() - parentDirFd, cName, err := fs.openBackingDir(relPath) - if err != nil { - return fuse.ToStatus(err) - } - defer syscall.Close(parentDirFd) - if fs.args.PlaintextNames { - // Unlinkat with AT_REMOVEDIR is equivalent to Rmdir - err = unix.Unlinkat(parentDirFd, cName, unix.AT_REMOVEDIR) - return fuse.ToStatus(err) - } - // Unless we are running as root, we need read, write and execute permissions - // to handle gocryptfs.diriv. - permWorkaround := false - var origMode uint32 - if !fs.args.PreserveOwner { - var st unix.Stat_t - err = syscallcompat.Fstatat(parentDirFd, cName, &st, unix.AT_SYMLINK_NOFOLLOW) - if err != nil { - return fuse.ToStatus(err) - } - if st.Mode&0700 != 0700 { - tlog.Debug.Printf("Rmdir: permWorkaround") - permWorkaround = true - // This cast is needed on Darwin, where st.Mode is uint16. - origMode = uint32(st.Mode) - err = syscallcompat.FchmodatNofollow(parentDirFd, cName, origMode|0700) - if err != nil { - tlog.Debug.Printf("Rmdir: permWorkaround: chmod failed: %v", err) - return fuse.ToStatus(err) - } - } - } - dirfd, err := syscallcompat.Openat(parentDirFd, cName, - syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NOFOLLOW, 0) - if err != nil { - tlog.Debug.Printf("Rmdir: Open: %v", err) - return fuse.ToStatus(err) - } - defer syscall.Close(dirfd) - // Undo the chmod if removing the directory failed. This must run before - // closing dirfd, so defer it after (defer is LIFO). - if permWorkaround { - defer func() { - if code != fuse.OK { - err = unix.Fchmod(dirfd, origMode) - if err != nil { - tlog.Warn.Printf("Rmdir: permWorkaround: rollback failed: %v", err) - } - } - }() - } -retry: - // Check directory contents - children, err := syscallcompat.Getdents(dirfd) - if err == io.EOF { - // The directory is empty - tlog.Warn.Printf("Rmdir: %q: %s is missing", cName, nametransform.DirIVFilename) - err = unix.Unlinkat(parentDirFd, cName, unix.AT_REMOVEDIR) - return fuse.ToStatus(err) - } - if err != nil { - tlog.Warn.Printf("Rmdir: Readdirnames: %v", err) - return fuse.ToStatus(err) - } - // MacOS sprinkles .DS_Store files everywhere. This is hard to avoid for - // users, so handle it transparently here. - if runtime.GOOS == "darwin" && len(children) <= 2 && haveDsstore(children) { - err = unix.Unlinkat(dirfd, dsStoreName, 0) - if err != nil { - tlog.Warn.Printf("Rmdir: failed to delete blocking file %q: %v", dsStoreName, err) - return fuse.ToStatus(err) - } - tlog.Warn.Printf("Rmdir: had to delete blocking file %q", dsStoreName) - goto retry - } - // If the directory is not empty besides gocryptfs.diriv, do not even - // attempt the dance around gocryptfs.diriv. - if len(children) > 1 { - return fuse.ToStatus(syscall.ENOTEMPTY) - } - // Move "gocryptfs.diriv" to the parent dir as "gocryptfs.diriv.rmdir.XYZ" - tmpName := fmt.Sprintf("%s.rmdir.%d", nametransform.DirIVFilename, cryptocore.RandUint64()) - tlog.Debug.Printf("Rmdir: Renaming %s to %s", nametransform.DirIVFilename, tmpName) - // The directory is in an inconsistent state between rename and rmdir. - // Protect against concurrent readers. - fs.dirIVLock.Lock() - defer fs.dirIVLock.Unlock() - err = syscallcompat.Renameat(dirfd, nametransform.DirIVFilename, - parentDirFd, tmpName) - if err != nil { - tlog.Warn.Printf("Rmdir: Renaming %s to %s failed: %v", - nametransform.DirIVFilename, tmpName, err) - return fuse.ToStatus(err) - } - // Actual Rmdir - err = syscallcompat.Unlinkat(parentDirFd, cName, unix.AT_REMOVEDIR) - if err != nil { - // This can happen if another file in the directory was created in the - // meantime, undo the rename - err2 := syscallcompat.Renameat(parentDirFd, tmpName, - dirfd, nametransform.DirIVFilename) - if err2 != nil { - tlog.Warn.Printf("Rmdir: Rename rollback failed: %v", err2) - } - return fuse.ToStatus(err) - } - // Delete "gocryptfs.diriv.rmdir.XYZ" - err = syscallcompat.Unlinkat(parentDirFd, tmpName, 0) - if err != nil { - tlog.Warn.Printf("Rmdir: Could not clean up %s: %v", tmpName, err) - } - // Delete .name file - if nametransform.IsLongContent(cName) { - nametransform.DeleteLongNameAt(parentDirFd, cName) - } - return fuse.OK -} - -// OpenDir - FUSE call -// -// This function is symlink-safe through use of openBackingDir() and -// ReadDirIVAt(). -func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) { - tlog.Debug.Printf("OpenDir(%s)", dirName) - parentDirFd, cDirName, err := fs.openBackingDir(dirName) - if err != nil { - return nil, fuse.ToStatus(err) - } - defer syscall.Close(parentDirFd) - // Read ciphertext directory - var cipherEntries []fuse.DirEntry - var status fuse.Status - fd, err := syscallcompat.Openat(parentDirFd, cDirName, syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NOFOLLOW, 0) - if err != nil { - return nil, fuse.ToStatus(err) - } - defer syscall.Close(fd) - cipherEntries, err = syscallcompat.Getdents(fd) - if err != nil { - return nil, fuse.ToStatus(err) - } - // Get DirIV (stays nil if PlaintextNames is used) - var cachedIV []byte - if !fs.args.PlaintextNames { - // Read the DirIV from disk - cachedIV, err = nametransform.ReadDirIVAt(fd) - if err != nil { - tlog.Warn.Printf("OpenDir %q: could not read %s: %v", cDirName, nametransform.DirIVFilename, err) - return nil, fuse.EIO - } - } - // Decrypted directory entries - var plain []fuse.DirEntry - // Filter and decrypt filenames - for i := range cipherEntries { - cName := cipherEntries[i].Name - if dirName == "" && cName == configfile.ConfDefaultName { - // silently ignore "gocryptfs.conf" in the top level dir - continue - } - if fs.args.PlaintextNames { - plain = append(plain, cipherEntries[i]) - continue - } - if cName == nametransform.DirIVFilename { - // silently ignore "gocryptfs.diriv" everywhere if dirIV is enabled - continue - } - // Handle long file name - isLong := nametransform.LongNameNone - if fs.args.LongNames { - isLong = nametransform.NameType(cName) - } - if isLong == nametransform.LongNameContent { - cNameLong, err := nametransform.ReadLongNameAt(fd, cName) - if err != nil { - tlog.Warn.Printf("OpenDir %q: invalid entry %q: Could not read .name: %v", - cDirName, cName, err) - fs.reportMitigatedCorruption(cName) - continue - } - cName = cNameLong - } else if isLong == nametransform.LongNameFilename { - // ignore "gocryptfs.longname.*.name" - continue - } - name, err := fs.nameTransform.DecryptName(cName, cachedIV) - if err != nil { - tlog.Warn.Printf("OpenDir %q: invalid entry %q: %v", - cDirName, cName, err) - fs.reportMitigatedCorruption(cName) - continue - } - // Override the ciphertext name with the plaintext name but reuse the rest - // of the structure - cipherEntries[i].Name = name - plain = append(plain, cipherEntries[i]) - } - - return plain, status -} |