lib/osutil: Fix TraversesSymlink with symlinked fs root on windows (fixes #4875) (#4886)

This commit is contained in:
Simon Frei 2018-04-17 22:53:06 +02:00 committed by Jakob Borg
parent 17e3608865
commit 1f70f7e37c
2 changed files with 55 additions and 22 deletions

View File

@ -32,29 +32,22 @@ func (e NotADirectoryError) Error() string {
return fmt.Sprintf("not a directory: %s", e.path)
}
// TraversesSymlink returns an error if base and any path component of name up to and
// including filepath.Join(base, name) traverses a symlink.
// Base and name must both be clean and name must be relative to base.
// TraversesSymlink returns an error if any path component of name (including name
// itself) traverses a symlink.
func TraversesSymlink(filesystem fs.Filesystem, name string) error {
base := "."
path := base
info, err := filesystem.Lstat(path)
var err error
name, err = fs.Canonicalize(name)
if err != nil {
return err
}
if !info.IsDir() {
return &NotADirectoryError{
path: base,
}
}
if name == "." {
// The result of calling TraversesSymlink("some/where", filepath.Dir("foo"))
// The result of calling TraversesSymlink(filesystem, filepath.Dir("foo"))
return nil
}
parts := strings.Split(name, string(fs.PathSeparator))
for _, part := range parts {
var path string
for _, part := range strings.Split(name, string(fs.PathSeparator)) {
path = filepath.Join(path, part)
info, err := filesystem.Lstat(path)
if err != nil {
@ -65,12 +58,12 @@ func TraversesSymlink(filesystem fs.Filesystem, name string) error {
}
if info.IsSymlink() {
return &TraversesSymlinkError{
path: strings.TrimPrefix(path, base),
path: path,
}
}
if !info.IsDir() {
return &NotADirectoryError{
path: strings.TrimPrefix(path, base),
path: path,
}
}
}

View File

@ -4,12 +4,13 @@
// 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 osutil_test
import (
"io/ioutil"
"os"
"path/filepath"
"runtime"
"testing"
"github.com/syncthing/syncthing/lib/fs"
@ -17,12 +18,20 @@ import (
)
func TestTraversesSymlink(t *testing.T) {
os.RemoveAll("testdata")
defer os.RemoveAll("testdata")
tmpDir, err := ioutil.TempDir(".", ".test-TraversesSymlink-")
if err != nil {
panic("Failed to create temporary testing dir")
}
defer os.RemoveAll(tmpDir)
fs := fs.NewFilesystem(fs.FilesystemTypeBasic, "testdata")
fs := fs.NewFilesystem(fs.FilesystemTypeBasic, tmpDir)
fs.MkdirAll("a/b/c", 0755)
fs.CreateSymlink("b", "a/l")
if err = osutil.DebugSymlinkForTestsOnly(filepath.Join(fs.URI(), "a", "b"), filepath.Join(fs.URI(), "a", "l")); err != nil {
if runtime.GOOS == "windows" {
t.Skip("Symlinks aren't working")
}
t.Fatal(err)
}
// a/l -> b, so a/l/c should resolve by normal stat
info, err := fs.Lstat("a/l/c")
@ -61,6 +70,37 @@ func TestTraversesSymlink(t *testing.T) {
}
}
func TestIssue4875(t *testing.T) {
tmpDir, err := ioutil.TempDir("", ".test-Issue4875-")
if err != nil {
panic("Failed to create temporary testing dir")
}
defer os.RemoveAll(tmpDir)
testFs := fs.NewFilesystem(fs.FilesystemTypeBasic, tmpDir)
testFs.MkdirAll("a/b/c", 0755)
if err = osutil.DebugSymlinkForTestsOnly(filepath.Join(testFs.URI(), "a", "b"), filepath.Join(testFs.URI(), "a", "l")); err != nil {
if runtime.GOOS == "windows" {
t.Skip("Symlinks aren't working")
}
t.Fatal(err)
}
// a/l -> b, so a/l/c should resolve by normal stat
info, err := testFs.Lstat("a/l/c")
if err != nil {
t.Fatal("unexpected error", err)
}
if !info.IsDir() {
t.Fatal("error in setup, a/l/c should be a directory")
}
testFs = fs.NewFilesystem(fs.FilesystemTypeBasic, filepath.Join(tmpDir, "a/l"))
if err := osutil.TraversesSymlink(testFs, "."); err != nil {
t.Error(`TraversesSymlink on filesystem with symlink at root returned error for ".":`, err)
}
}
var traversesSymlinkResult error
func BenchmarkTraversesSymlink(b *testing.B) {