From 889ae900814aac1c17c38a76882b1aafa5744be6 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Tue, 8 Sep 2015 00:54:24 +0200 Subject: Add pathfs frontend (uses go-fuse instead of bazil-fuse), part I Currently fails main_test.go, will be fixed in part II --- pathfs_frontend/fs.go | 166 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) create mode 100644 pathfs_frontend/fs.go (limited to 'pathfs_frontend/fs.go') diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go new file mode 100644 index 0000000..2f73462 --- /dev/null +++ b/pathfs_frontend/fs.go @@ -0,0 +1,166 @@ +package pathfs_frontend + +import ( + "os" + "path/filepath" + "time" + "fmt" + + "github.com/hanwen/go-fuse/fuse" + "github.com/hanwen/go-fuse/fuse/nodefs" + "github.com/hanwen/go-fuse/fuse/pathfs" + "github.com/rfjakob/gocryptfs/cryptfs" +) + +type FS struct { + *cryptfs.CryptFS + pathfs.FileSystem // loopbackFileSystem + backing string // Backing directory +} + +// Encrypted FUSE overlay filesystem +func NewFS(key [16]byte, backing string, useOpenssl bool) *FS { + return &FS{ + CryptFS: cryptfs.NewCryptFS(key, useOpenssl), + FileSystem: pathfs.NewLoopbackFileSystem(backing), + backing: backing, + + } +} + +// GetPath - get the absolute path of the backing file +func (fs *FS) GetPath(relPath string) string { + return filepath.Join(fs.backing, fs.EncryptPath(relPath)) +} + +func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) { + a, status := fs.FileSystem.GetAttr(fs.EncryptPath(name), context) + if a == nil { + return a, status + } + + a.Size = fs.PlainSize(a.Size) + return a, status +} + +func (fs *FS) OpenDir(name string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) { + cipherEntries, status := fs.FileSystem.OpenDir(fs.EncryptPath(name), context); + var plain []fuse.DirEntry + var skipped int + if cipherEntries != nil { + for i := range cipherEntries { + n, err := fs.DecryptPath(cipherEntries[i].Name) + if err != nil { + fmt.Printf("Skipping invalid filename \"%s\": %s\n", cipherEntries[i].Name, err) + skipped++ + continue + } + cipherEntries[i].Name = n + plain = append(plain, cipherEntries[i]) + } + } + return plain, status +} + +// We always need read access to do read-modify-write cycles +func (fs *FS) mangleOpenFlags(flags uint32) (newFlags int, writeOnly bool) { + newFlags = int(flags) + if newFlags & os.O_WRONLY > 0 { + writeOnly = true + newFlags = newFlags ^ os.O_WRONLY | os.O_RDWR + } + // We also cannot open the file in append mode, we need to seek back for RMW + newFlags = newFlags &^ os.O_APPEND + + return newFlags, writeOnly +} + +func (fs *FS) Open(name string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) { + cryptfs.Debug.Printf("Open(%s)\n", name) + + iflags, writeOnly := fs.mangleOpenFlags(flags) + f, err := os.OpenFile(fs.GetPath(name), iflags, 0666) + if err != nil { + return nil, fuse.ToStatus(err) + } + + return NewFile(f, writeOnly, fs.CryptFS), fuse.OK +} + +func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Context) (fuseFile nodefs.File, code fuse.Status) { + iflags, writeOnly := fs.mangleOpenFlags(flags) + f, err := os.OpenFile(fs.GetPath(path), iflags|os.O_CREATE, os.FileMode(mode)) + if err != nil { + return nil, fuse.ToStatus(err) + } + return NewFile(f, writeOnly, fs.CryptFS), fuse.OK +} + +func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Chmod(fs.EncryptPath(path), mode, context) +} + +func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Chmod(fs.EncryptPath(path), gid, context) +} + +func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Truncate(fs.EncryptPath(path), offset, context) +} + +func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Utimens(fs.EncryptPath(path), Atime, Mtime, context) +} + +func (fs *FS) Readlink(name string, context *fuse.Context) (out string, code fuse.Status) { + return fs.FileSystem.Readlink(fs.EncryptPath(name), context) +} + +func (fs *FS) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Mknod(fs.EncryptPath(name), mode, dev, context) +} + +func (fs *FS) Mkdir(path string, mode uint32, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Mkdir(fs.EncryptPath(path), mode, context) +} + +func (fs *FS) Unlink(name string, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Unlink(fs.EncryptPath(name), context) +} + +func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Rmdir(fs.EncryptPath(name), context) +} + +func (fs *FS) Symlink(pointedTo string, linkName string, context *fuse.Context) (code fuse.Status) { + // TODO symlink encryption + return fs.FileSystem.Symlink(fs.EncryptPath(pointedTo), fs.EncryptPath(linkName), context) +} + +func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (codee fuse.Status) { + return fs.FileSystem.Rename(fs.EncryptPath(oldPath), fs.EncryptPath(newPath), context) +} + +func (fs *FS) Link(orig string, newName string, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Link(fs.EncryptPath(orig), fs.EncryptPath(newName), context) +} + +func (fs *FS) Access(name string, mode uint32, context *fuse.Context) (code fuse.Status) { + return fs.FileSystem.Access(fs.EncryptPath(name), mode, context) +} + +func (fs *FS) GetXAttr(name string, attr string, context *fuse.Context) ([]byte, fuse.Status) { + return nil, fuse.ENOSYS +} + +func (fs *FS) SetXAttr(name string, attr string, data []byte, flags int, context *fuse.Context) fuse.Status { + return fuse.ENOSYS +} + +func (fs *FS) ListXAttr(name string, context *fuse.Context) ([]string, fuse.Status) { + return nil, fuse.ENOSYS +} + +func (fs *FS) RemoveXAttr(name string, attr string, context *fuse.Context) fuse.Status { + return fuse.ENOSYS +} -- cgit v1.2.3