xref: /freebsd/lib/libc/gen/initgroups.c (revision 4f52dfbb8d6c4d446500c5b097e3806ec219fbd4)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)initgroups.c	8.1 (Berkeley) 6/4/93";
34 #endif
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 
40 #include "namespace.h"
41 #include <err.h>
42 #include "un-namespace.h"
43 #include <errno.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 
48 int
49 initgroups(const char *uname, gid_t agroup)
50 {
51 	int ngroups, ret;
52 	long ngroups_max;
53 	gid_t *groups;
54 
55 	/*
56 	 * Provide space for one group more than possible to allow
57 	 * setgroups to fail and set errno.
58 	 */
59 	ngroups_max = sysconf(_SC_NGROUPS_MAX) + 2;
60 	if ((groups = malloc(sizeof(*groups) * ngroups_max)) == NULL)
61 		return (ENOMEM);
62 
63 	ngroups = (int)ngroups_max;
64 	getgrouplist(uname, agroup, groups, &ngroups);
65 	ret = setgroups(ngroups, groups);
66 	free(groups);
67 	return (ret);
68 }
69