fusefrontend: move openBackingDir into its own file

This function is in all fastpaths, will get a cache, and needs
its own file.
renamed:    internal/fusefrontend/names.go -> internal/fusefrontend/openbackingdir.go
renamed:    internal/fusefrontend/names_test.go -> internal/fusefrontend/openbackingdir_test.go

1 files changed, 0 insertions, 85 deletions

diff --git a/internal/fusefrontend/names.go b/internal/fusefrontend/names.go
deleted file mode 100644
index 63f2e84..0000000
--- a/internal/fusefrontend/names.go
+++ /dev/null
@@ -1,85 +0,0 @@
-package fusefrontend
-
-// This file forwards file encryption operations to cryptfs
-
-import (
-	"path/filepath"
-	"strings"
-	"syscall"
-
-	"github.com/rfjakob/gocryptfs/internal/configfile"
-	"github.com/rfjakob/gocryptfs/internal/nametransform"
-	"github.com/rfjakob/gocryptfs/internal/syscallcompat"
-	"github.com/rfjakob/gocryptfs/internal/tlog"
-)
-
-// isFiltered - check if plaintext "path" should be forbidden
-//
-// Prevents name clashes with internal files when file names are not encrypted
-func (fs *FS) isFiltered(path string) bool {
-	if !fs.args.PlaintextNames {
-		return false
-	}
-	// gocryptfs.conf in the root directory is forbidden
-	if path == configfile.ConfDefaultName {
-		tlog.Info.Printf("The name /%s is reserved when -plaintextnames is used\n",
-			configfile.ConfDefaultName)
-		return true
-	}
-	// Note: gocryptfs.diriv is NOT forbidden because diriv and plaintextnames
-	// are exclusive
-	return false
-}
-
-// openBackingDir opens the parent ciphertext directory of plaintext path
-// "relPath" and returns the dirfd and the encrypted basename.
-//
-// The caller should then use Openat(dirfd, cName, ...) and friends.
-// For convenience, if relPath is "", cName is going to be ".".
-//
-// openBackingDir is secure against symlink races by using Openat and
-// ReadDirIVAt.
-func (fs *FS) openBackingDir(relPath string) (dirfd int, cName string, err error) {
-	// With PlaintextNames, we don't need to read DirIVs. Easy.
-	if fs.args.PlaintextNames {
-		dir := nametransform.Dir(relPath)
-		dirfd, err = syscallcompat.OpenDirNofollow(fs.args.Cipherdir, dir)
-		if err != nil {
-			return -1, "", err
-		}
-		// If relPath is empty, cName is ".".
-		cName = filepath.Base(relPath)
-		return dirfd, cName, nil
-	}
-	// Open cipherdir (following symlinks)
-	dirfd, err = syscall.Open(fs.args.Cipherdir, syscall.O_RDONLY|syscall.O_DIRECTORY|syscallcompat.O_PATH, 0)
-	if err != nil {
-		return -1, "", err
-	}
-	// If relPath is empty, cName is ".".
-	if relPath == "" {
-		return dirfd, ".", nil
-	}
-	// Walk the directory tree
-	parts := strings.Split(relPath, "/")
-	for i, name := range parts {
-		iv, err := nametransform.ReadDirIVAt(dirfd)
-		if err != nil {
-			syscall.Close(dirfd)
-			return -1, "", err
-		}
-		cName = fs.nameTransform.EncryptAndHashName(name, iv)
-		// Last part? We are done.
-		if i == len(parts)-1 {
-			break
-		}
-		// Not the last part? Descend into next directory.
-		dirfd2, err := syscallcompat.Openat(dirfd, cName, syscall.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_DIRECTORY|syscallcompat.O_PATH, 0)
-		syscall.Close(dirfd)
-		if err != nil {
-			return -1, "", err
-		}
-		dirfd = dirfd2
-	}
-	return dirfd, cName, nil
-}