xref: /freebsd/lib/libc/gen/initgroups.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)initgroups.c	8.1 (Berkeley) 6/4/93";
32 #endif
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 
38 #include "namespace.h"
39 #include <err.h>
40 #include "un-namespace.h"
41 #include <errno.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 
46 int
47 initgroups(const char *uname, gid_t agroup)
48 {
49 	int ngroups, ret;
50 	long ngroups_max;
51 	gid_t *groups;
52 
53 	/*
54 	 * Provide space for one group more than possible to allow
55 	 * setgroups to fail and set errno.
56 	 */
57 	ngroups_max = sysconf(_SC_NGROUPS_MAX) + 2;
58 	if ((groups = malloc(sizeof(*groups) * ngroups_max)) == NULL)
59 		return (ENOMEM);
60 
61 	ngroups = (int)ngroups_max;
62 	getgrouplist(uname, agroup, groups, &ngroups);
63 	ret = setgroups(ngroups, groups);
64 	free(groups);
65 	return (ret);
66 }
67