sisyphus: check base names for filepath separators

Fixes #2.

dir.go

@@ -6,6 +6,8 @@ package sisyphus
 
 import (
 	"os"
+	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 
@@ -34,14 +36,27 @@ var (
 )
 
 // NewDir returns a new Dir with the given name and file mode.
-func NewDir(name string, mode os.FileMode) *Dir {
+func NewDir(name string, mode os.FileMode) (*Dir, error) {
+	if name != "/" && strings.Contains(name, string(filepath.Separator)) {
+		return nil, ErrBadName
+	}
 	return &Dir{
 		name: name,
 		attr: attr{
 			mode: os.ModeDir | mode&^(os.ModeSymlink|os.ModeNamedPipe|os.ModeSocket),
 		},
 		files: make(map[string]Node),
+	}, nil
+}
+
+// MustNewDir returns a new Dir with the given name and file mode. It
+// will panic if name contains a filepath separator unless name is "/".
+func MustNewDir(name string, mode os.FileMode) *Dir {
+	d, err := NewDir(name, mode)
+	if err != nil {
+		panic(err)
 	}
+	return d
 }
 
 // Own sets the uid and gid of the directory.

fs.go

@@ -49,7 +49,7 @@ var nofs *FileSystem
 func NewFileSystem(mode os.FileMode, clock func() time.Time) *FileSystem {
 	var fs FileSystem
 	fs.now = clock
-	fs.root = NewDir("/", mode)
+	fs.root, _ = NewDir("/", mode)
 	fs.root.SetSys(&fs)
 	return &fs
 }

ro_node.go

@@ -7,6 +7,8 @@ package sisyphus
 import (
 	"io"
 	"os"
+	"path/filepath"
+	"strings"
 	"sync"
 	"syscall"
 	"time"
@@ -45,14 +47,27 @@ var (
 )
 
 // NewRO returns a new RO file with the given name and file mode.
-func NewRO(name string, mode os.FileMode, dev Reader) *RO {
+func NewRO(name string, mode os.FileMode, dev Reader) (*RO, error) {
+	if strings.Contains(name, string(filepath.Separator)) {
+		return nil, ErrBadName
+	}
 	return &RO{
 		name: name,
 		attr: attr{
 			mode: mode &^ (os.ModeDir | 0222),
 		},
 		dev: dev,
+	}, nil
+}
+
+// MustNewRO returns a new RO with the given name and file mode. It
+// will panic if name contains a filepath separator.
+func MustNewRO(name string, mode os.FileMode, dev Reader) *RO {
+	ro, err := NewRO(name, mode, dev)
+	if err != nil {
+		panic(err)
 	}
+	return ro
 }
 
 // Own sets the uid and gid of the file.

rw_node.go

@@ -7,6 +7,8 @@ package sisyphus
 import (
 	"io"
 	"os"
+	"path/filepath"
+	"strings"
 	"sync"
 	"syscall"
 	"time"
@@ -50,14 +52,27 @@ var (
 )
 
 // NewRW returns a new RW file with the given name and file mode.
-func NewRW(name string, mode os.FileMode, dev ReadWriter) *RW {
+func NewRW(name string, mode os.FileMode, dev ReadWriter) (*RW, error) {
+	if strings.Contains(name, string(filepath.Separator)) {
+		return nil, ErrBadName
+	}
 	return &RW{
 		name: name,
 		attr: attr{
 			mode: mode &^ os.ModeDir,
 		},
 		dev: dev,
+	}, nil
+}
+
+// MustNewRW returns a new RW with the given name and file mode. It
+// will panic if name contains a filepath separator.
+func MustNewRW(name string, mode os.FileMode, dev ReadWriter) *RW {
+	rw, err := NewRW(name, mode, dev)
+	if err != nil {
+		panic(err)
 	}
+	return rw
 }
 
 // Own sets the uid and gid of the file.

sisyphus.go

@@ -6,6 +6,7 @@
 package sisyphus
 
 import (
+	"errors"
 	"io"
 	"os"
 	"sync"
@@ -16,6 +17,10 @@ import (
 	"bazil.org/fuse/fs"
 )
 
+// ErrBadName is returned when a new Node is created with a base name
+// that contains a filepath separator.
+var ErrBadName = errors.New("sisyphus: base contains filepath separator")
+
 // server is a FUSE server for a FileSystem.
 type server struct {
 	mnt  string

sisyphus_test.go

@@ -38,10 +38,10 @@ func init() {
 }
 
 var (
-	d  = NewDir
-	ro = NewRO
-	rw = NewRW
-	wo = NewWO
+	d  = MustNewDir
+	ro = MustNewRO
+	rw = MustNewRW
+	wo = MustNewWO
 )
 
 func sysfs(t *testing.T, comm chan string) *FileSystem {

wo_node.go

@@ -7,6 +7,8 @@ package sisyphus
 import (
 	"io"
 	"os"
+	"path/filepath"
+	"strings"
 	"sync"
 	"syscall"
 	"time"
@@ -48,14 +50,27 @@ var (
 )
 
 // NewWO returns a new WO file with the given name and file mode.
-func NewWO(name string, mode os.FileMode, dev Writer) *WO {
+func NewWO(name string, mode os.FileMode, dev Writer) (*WO, error) {
+	if strings.Contains(name, string(filepath.Separator)) {
+		return nil, ErrBadName
+	}
 	return &WO{
 		name: name,
 		attr: attr{
 			mode: mode &^ (os.ModeDir | 0444),
 		},
 		dev: dev,
+	}, nil
+}
+
+// MustNewWO returns a new RO with the given name and file mode. It
+// will panic if name contains a filepath separator.
+func MustNewWO(name string, mode os.FileMode, dev Writer) *WO {
+	wo, err := NewWO(name, mode, dev)
+	if err != nil {
+		panic(err)
 	}
+	return wo
 }
 
 // Own sets the uid and gid of the file.