1 /*
2  * Copyright (c) Wipro Technologies Ltd, 2002.  All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * You should have received a copy of the GNU General Public License along
13  * with this program; if not, write the Free Software Foundation, Inc.,
14  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
15  *
16  */
17 
18 /*
19  * Description: This is a setuid to root program invoked by a non-root
20  *              process to validate the mount flag MS_NOSUID.
21  *
22  *              This function exit with 0 or 1 depending upon the
23  *              success/failure of setuid(2) system call.
24  */
25 
26 #include <stdio.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <stdlib.h>
30 #include <stdlib.h>
31 #include <errno.h>
32 
33 /* Save the effective and real UIDs. */
34 
35 static uid_t ruid;
36 
37 /* Restore the effective UID to its original value. */
38 
39 int do_setuid(void)
40 {
41 	int status;
42 
43 	status = setreuid(ruid, 0);
44 	if (status < 0) {
45 		return 1;
46 	} else {
47 		return 0;
48 	}
49 	return 0;
50 }
51 
52 /* Main program. */
53 
54 int main(void)
55 {
56 	int exit_status;
57 
58 	/* Save the real and effective user IDs.  */
59 	ruid = getuid();
60 	exit_status = do_setuid();
61 
62 	exit(exit_status);
63 }
64