xref: /titanic_41/usr/src/lib/libc/port/gen/initgroups.c (revision 7b9b3bf3fd4f7bfad91fce91e3e9fba62ac85c77)
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  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*	Copyright (c) 1988 AT&T	*/
29 /*	  All Rights Reserved  	*/
30 
31 
32 #pragma weak initgroups = _initgroups
33 
34 #include "synonyms.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 */
43 extern int _getgroupsbymember(const char *, gid_t[], int, int);
44 
45 int
46 initgroups(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