xref: /dragonfly/lib/libc/gen/getgrouplist.c (revision 1de703da)
1 /*
2  * Copyright (c) 1991, 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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)getgrouplist.c	8.2 (Berkeley) 12/8/94
34  */
35 
36 /*
37  * get credential
38  */
39 #include <sys/types.h>
40 #include <string.h>
41 #include <grp.h>
42 
43 int
44 getgrouplist(uname, agroup, groups, grpcnt)
45 	const char *uname;
46 	int agroup;
47 	register int *groups;
48 	int *grpcnt;
49 {
50 	register struct group *grp;
51 	register int i, ngroups;
52 	int ret, maxgroups;
53 
54 	ret = 0;
55 	ngroups = 0;
56 	maxgroups = *grpcnt;
57 	/*
58 	 * When installing primary group, duplicate it;
59 	 * the first element of groups is the effective gid
60 	 * and will be overwritten when a setgid file is executed.
61 	 */
62 	groups[ngroups++] = agroup;
63 	if (maxgroups > 1)
64 		groups[ngroups++] = agroup;
65 	/*
66 	 * Scan the group file to find additional groups.
67 	 */
68 	setgrent();
69 	while (grp = getgrent()) {
70 		for (i = 0; i < ngroups; i++) {
71 			if (grp->gr_gid == groups[i])
72 				goto skip;
73 		}
74 		for (i = 0; grp->gr_mem[i]; i++) {
75 			if (!strcmp(grp->gr_mem[i], uname)) {
76 				if (ngroups >= maxgroups) {
77 					ret = -1;
78 					break;
79 				}
80 				groups[ngroups++] = grp->gr_gid;
81 				break;
82 			}
83 		}
84 skip:
85 	}
86 	endgrent();
87 	*grpcnt = ngroups;
88 	return (ret);
89 }
90