On Sun, Mar 29, 2015 at 09:50:48PM +0200, Alexander Bluhm wrote:
> Hi,
>
> While doing make makesum in the ports framework, I realized that
> the distinfo file always gets permissions 0600. It uses sort -o
> in a way that the output file will overwrite the input file. In
> this case, sort creates a temp file with 0600 and replaces the
> output file at the end.
>
> I would like semantics where the permissions are preserved. So in
> case of overwriting a file, use the minimum of umask and original
> permissions. While there, prevent overwriting files without write
> access.
>
> comment/ok?
If you call umask(2), it's better to reset it to the old value after
you're done.
But it's likely better to fchmod the file while we have it still open.
-Otto
>
> bluhm
>
> Index: usr.bin/sort/sort.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/usr.bin/sort/sort.c,v
> retrieving revision 1.48
> diff -u -p -r1.48 sort.c
> --- usr.bin/sort/sort.c 20 Mar 2015 23:04:07 -0000 1.48
> +++ usr.bin/sort/sort.c 29 Mar 2015 18:16:19 -0000
> @@ -1194,6 +1194,17 @@ main(int argc, char *argv[])
> }
>
> if (real_outfile) {
> + struct stat sb;
> + mode_t mask;
> +
> + if (stat(real_outfile, &sb) < 0)
> + err(2, "%s", real_outfile);
> + if (access(real_outfile, W_OK) < 0)
> + err(2, "write %s", real_outfile);
> + mask = umask(0);
> + umask(mask);
> + chmod(outfile, sb.st_mode & ~mask & (S_IRWXU|S_IRWXG|S_IRWXO));
> +
> unlink(real_outfile);
> if (rename(outfile, real_outfile) < 0)
> err(2, "%s", real_outfile);
