func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (nlink uint32, inode uint64, err error) { s, ok := stat.(*syscall.Stat_t) if !ok { err = errors.New("cannot convert stat value to syscall.Stat_t") return } nlink = uint32(s.Nlink) inode = uint64(s.Ino) // Currently go does not fil in the major/minors if s.Mode&syscall.S_IFBLK == syscall.S_IFBLK || s.Mode&syscall.S_IFCHR == syscall.S_IFCHR { hdr.Devmajor = int64(major(uint64(s.Rdev))) hdr.Devminor = int64(minor(uint64(s.Rdev))) } return }
func fakeTar() (io.Reader, error) { uid := os.Getuid() gid := os.Getgid() content := []byte("Hello world!\n") buf := new(bytes.Buffer) tw := tar.NewWriter(buf) for _, name := range []string{"/etc/postgres/postgres.conf", "/etc/passwd", "/var/log/postgres/postgres.conf"} { hdr := new(tar.Header) // Leaving these fields blank requires root privileges hdr.Uid = uid hdr.Gid = gid hdr.Size = int64(len(content)) hdr.Name = name if err := tw.WriteHeader(hdr); err != nil { return nil, err } tw.Write([]byte(content)) } tw.Close() return buf, nil }
func createTarFile(path, extractDir string, hdr *tar.Header, reader io.Reader, Lchown bool) error { // hdr.Mode is in linux format, which we can use for sycalls, // but for os.Foo() calls we need the mode converted to os.FileMode, // so use hdrInfo.Mode() (they differ for e.g. setuid bits) hdrInfo := hdr.FileInfo() switch hdr.Typeflag { case tar.TypeDir: // Create directory unless it exists as a directory already. // In that case we just want to merge the two if fi, err := os.Lstat(path); !(err == nil && fi.IsDir()) { if err := os.Mkdir(path, hdrInfo.Mode()); err != nil { return err } } case tar.TypeReg, tar.TypeRegA: // Source is regular file file, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY, hdrInfo.Mode()) if err != nil { return err } if _, err := io.Copy(file, reader); err != nil { file.Close() return err } file.Close() case tar.TypeBlock, tar.TypeChar, tar.TypeFifo: mode := uint32(hdr.Mode & 07777) switch hdr.Typeflag { case tar.TypeBlock: mode |= syscall.S_IFBLK case tar.TypeChar: mode |= syscall.S_IFCHR case tar.TypeFifo: mode |= syscall.S_IFIFO } if err := syscall.Mknod(path, mode, int(mkdev(hdr.Devmajor, hdr.Devminor))); err != nil { return err } case tar.TypeLink: if err := os.Link(filepath.Join(extractDir, hdr.Linkname), path); err != nil { return err } case tar.TypeSymlink: if err := os.Symlink(hdr.Linkname, path); err != nil { return err } case tar.TypeXGlobalHeader: utils.Debugf("PAX Global Extended Headers found and ignored") return nil default: return fmt.Errorf("Unhandled tar header type %d\n", hdr.Typeflag) } if err := os.Lchown(path, hdr.Uid, hdr.Gid); err != nil && Lchown { return err } for key, value := range hdr.Xattrs { if err := system.Lsetxattr(path, key, []byte(value), 0); err != nil { return err } } // There is no LChmod, so ignore mode for symlink. Also, this // must happen after chown, as that can modify the file mode if hdr.Typeflag != tar.TypeSymlink { if err := os.Chmod(path, hdrInfo.Mode()); err != nil { return err } } ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)} // syscall.UtimesNano doesn't support a NOFOLLOW flag atm, and if hdr.Typeflag != tar.TypeSymlink { if err := system.UtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform { return err } } else { if err := system.LUtimesNano(path, ts); err != nil && err != system.ErrNotSupportedPlatform { return err } } return nil }