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/*
* Copyright (c) 2001 Sendmail, Inc. and its suppliers.
* All rights reserved.
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the sendmail distribution.
*
*/
/*
** This program checks to see if your version of setgid works.
** Compile it, make it set-group-ID guest, and run it as yourself (NOT as
** root and not as member of the group guest).
**
** Compilation is trivial -- just "cc t_setgid.c". Make it set-group-ID,
** guest and then execute it as a non-root user.
*/
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#ifndef lint
static char id[] = "@(#)$Id: t_setgid.c,v 1.6 2001/09/23 03:35:41 ca Exp $";
#endif /* ! lint */
static void
printgids(str, r, e)
char *str;
gid_t r, e;
{
printf("%s (should be %d/%d): r/egid=%d/%d\n", str, (int) r, (int) e,
(int) getgid(), (int) getegid());
}
int
main(argc, argv)
int argc;
char **argv;
{
int fail = 0;
int res;
gid_t realgid = getgid();
gid_t effgid = getegid();
printgids("initial gids", realgid, effgid);
if (effgid == realgid)
{
printf("SETUP ERROR: re-run set-group-ID guest\n");
exit(1);
}
#if SM_CONF_SETREGID
res = setregid(effgid, effgid);
#else /* SM_CONF_SETREGID */
res = setgid(effgid);
#endif /* SM_CONF_SETREGID */
printf("setgid(%d)=%d %s\n", (int) effgid, res,
res < 0 ? "failure" : "ok");
#if SM_CONF_SETREGID
printgids("after setregid()", effgid, effgid);
#else /* SM_CONF_SETREGID */
printgids("after setgid()", effgid, effgid);
#endif /* SM_CONF_SETREGID */
if (getegid() != effgid)
{
fail++;
printf("MAYDAY! Wrong effective gid\n");
}
if (getgid() != effgid)
{
fail++;
printf("MAYDAY! Wrong real gid\n");
}
/* do activity here */
if (setgid(0) == 0)
{
fail++;
printf("MAYDAY! setgid(0) succeeded (should have failed)\n");
}
else
{
printf("setgid(0) failed (this is correct)\n");
}
printgids("after setgid(0)", effgid, effgid);
if (getegid() != effgid)
{
fail++;
printf("MAYDAY! Wrong effective gid\n");
}
if (getgid() != effgid)
{
fail++;
printf("MAYDAY! Wrong real gid\n");
}
printf("\n");
if (fail > 0)
{
printf("\nThis system cannot use %s to set the real gid to the effective gid\nand clear the saved gid.\n",
#if SM_CONF_SETREGID
"setregid"
#else /* SM_CONF_SETREGID */
"setgid"
#endif /* SM_CONF_SETREGID */
);
exit(1);
}
printf("\nIt is possible to use setgid on this system\n");
exit(0);
}
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