1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1988 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32#pragma weak _initgroups = initgroups
33
34#include "lint.h"
35#include <stdlib.h>
36#include <errno.h>
37#include <grp.h>
38#include <sys/types.h>
39#include <sys/param.h>
40#include <unistd.h>
41
42/* Private interface to the groups code in getgrnam.c */
43extern int _getgroupsbymember(const char *, gid_t[], int, int);
44
45int
46initgroups(const char *uname, gid_t agroup)
47{
48	gid_t *groups;
49	long ngroups_max;
50	int ngroups;
51	int errsave, retsave;
52
53	if ((ngroups_max = sysconf(_SC_NGROUPS_MAX)) < 0) {
54		/* ==== Hope sysconf() set errno to something sensible */
55		return (-1);
56	}
57	/*
58	 * ngroups_max is the maximum number of supplemental groups per
59	 * process. if no supplemental groups are allowed, we're done.
60	 */
61	if (ngroups_max == 0)
62		return (0);
63
64	if ((groups = (gid_t *)calloc(ngroups_max, sizeof (gid_t))) == 0) {
65		errno = ENOMEM;
66		return (-1);
67	}
68	groups[0] = agroup;
69
70	ngroups = _getgroupsbymember(uname, groups, (int)ngroups_max,
71	    (agroup <= MAXUID) ? 1 : 0);
72	if (ngroups < 0) {
73		/* XXX -- man page does not define a value for errno in */
74		/* this case.  Should be looked into sometime.	*/
75		free(groups);
76		return (-1);
77	}
78
79	retsave = setgroups(ngroups, groups);
80	errsave = errno;
81
82	free(groups);
83
84	errno = errsave;
85	return (retsave);
86}
87