syncthing/lib/fs/basicfs_unix.go
Jakob Borg 52d80d8144 lib/fs: Improve root check (#6033)
The root check would allow things like c:\foobar\baz if the root was
c:\foo, because string wise that's a prefix. Now it doesn't.
2019-09-29 23:38:11 +08:00

100 lines
2.7 KiB
Go

// Copyright (C) 2016 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
// +build !windows
package fs
import (
"os"
"path/filepath"
"strings"
)
func (BasicFilesystem) SymlinksSupported() bool {
return true
}
func (f *BasicFilesystem) CreateSymlink(target, name string) error {
name, err := f.rooted(name)
if err != nil {
return err
}
return os.Symlink(target, name)
}
func (f *BasicFilesystem) ReadSymlink(name string) (string, error) {
name, err := f.rooted(name)
if err != nil {
return "", err
}
return os.Readlink(name)
}
func (f *BasicFilesystem) mkdirAll(path string, perm os.FileMode) error {
return os.MkdirAll(path, perm)
}
// Unhide is a noop on unix, as unhiding files requires renaming them.
// We still check that the relative path does not try to escape the root
func (f *BasicFilesystem) Unhide(name string) error {
_, err := f.rooted(name)
return err
}
// Hide is a noop on unix, as hiding files requires renaming them.
// We still check that the relative path does not try to escape the root
func (f *BasicFilesystem) Hide(name string) error {
_, err := f.rooted(name)
return err
}
func (f *BasicFilesystem) Roots() ([]string, error) {
return []string{"/"}, nil
}
// unrootedChecked returns the path relative to the folder root (same as
// unrooted) or an error if the given path is not a subpath and handles the
// special case when the given path is the folder root without a trailing
// pathseparator.
func (f *BasicFilesystem) unrootedChecked(absPath string, roots []string) (string, *ErrWatchEventOutsideRoot) {
for _, root := range roots {
// Make sure the root ends with precisely one path separator, to
// ease prefix comparisons.
root := strings.TrimRight(root, string(PathSeparator)) + string(PathSeparator)
if absPath+string(PathSeparator) == root {
return ".", nil
}
if strings.HasPrefix(absPath, root) {
return rel(absPath, root), nil
}
}
return "", f.newErrWatchEventOutsideRoot(absPath, roots)
}
func rel(path, prefix string) string {
return strings.TrimPrefix(strings.TrimPrefix(path, prefix), string(PathSeparator))
}
var evalSymlinks = filepath.EvalSymlinks
// watchPaths adjust the folder root for use with the notify backend and the
// corresponding absolute path to be passed to notify to watch name.
func (f *BasicFilesystem) watchPaths(name string) (string, []string, error) {
root, err := evalSymlinks(f.root)
if err != nil {
return "", nil, err
}
absName, err := rooted(name, root)
if err != nil {
return "", nil, err
}
return filepath.Join(absName, "..."), []string{root}, nil
}