1 /* unlinkdir.c - determine (and maybe change) whether we can unlink directories
3 Copyright (C) 2005 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
19 /* Written by Paul Eggert and Jim Meyering. */
25 #include "unlinkdir.h"
32 #if ! UNLINK_CANNOT_UNLINK_DIR
34 /* Return true if we cannot unlink directories, false if we might be
35 able to unlink directories. If possible, tell the kernel we don't
36 want to be able to unlink directories, so that we can return true. */
39 cannot_unlink_dir (void)
41 static bool initialized;
46 # if defined PRIV_EFFECTIVE && defined PRIV_SYS_LINKDIR
47 /* We might be able to unlink directories if we cannot
48 determine our privileges, or if we have the
49 PRIV_SYS_LINKDIR privilege and cannot delete it. */
50 priv_set_t *pset = priv_allocset ();
54 (getppriv (PRIV_EFFECTIVE, pset) == 0
55 && (! priv_ismember (pset, PRIV_SYS_LINKDIR)
56 || (priv_delset (pset, PRIV_SYS_LINKDIR) == 0
57 && setppriv (PRIV_SET, PRIV_EFFECTIVE, pset) == 0)));
61 /* In traditional Unix, only root can unlink directories. */
62 cannot = (geteuid () != 0);