xref: /netbsd-src/lib/libc/gen/getgrouplist.c (revision 1f2744e6e4915c9da2a3f980279398c4cf7d5e6d)
1 /*	$NetBSD: getgrouplist.c,v 1.4 1995/02/25 13:41:09 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1991, 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)getgrouplist.c	8.1 (Berkeley) 6/4/93";
39 #else
40 static char rcsid[] = "$NetBSD: getgrouplist.c,v 1.4 1995/02/25 13:41:09 cgd Exp $";
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 /*
45  * get credential
46  */
47 #include <sys/types.h>
48 #include <string.h>
49 #include <grp.h>
50 
51 int
52 getgrouplist(uname, agroup, groups, grpcnt)
53 	const char *uname;
54 	int agroup;
55 	register int *groups;
56 	int *grpcnt;
57 {
58 	register struct group *grp;
59 	register struct passwd *pw;
60 	register int i, ngroups;
61 	int ret, maxgroups;
62 
63 	ret = 0;
64 	ngroups = 0;
65 	maxgroups = *grpcnt;
66 	/*
67 	 * When installing primary group, duplicate it;
68 	 * the first element of groups is the effective gid
69 	 * and will be overwritten when a setgid file is executed.
70 	 */
71 	groups[ngroups++] = agroup;
72 	if (maxgroups > 1)
73 		groups[ngroups++] = agroup;
74 	/*
75 	 * Scan the group file to find additional groups.
76 	 */
77 	setgrent();
78 	while (grp = getgrent()) {
79 		if (grp->gr_gid == agroup)
80 			continue;
81 		for (i = 0; grp->gr_mem[i]; i++) {
82 			if (!strcmp(grp->gr_mem[i], uname)) {
83 				if (ngroups >= maxgroups) {
84 					ret = -1;
85 					goto out;
86 				}
87 				groups[ngroups++] = grp->gr_gid;
88 				break;
89 			}
90 		}
91 	}
92 out:
93 	endgrent();
94 	*grpcnt = ngroups;
95 	return (ret);
96 }
97