xref: /netbsd-src/lib/libc/gen/initgroups.c (revision f67d02e52c789413ce33ba921e2f6246a18b2df2)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * 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 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 /*static char *sccsid = "from: @(#)initgroups.c	5.7 (Berkeley) 2/23/91";*/
36 static char *rcsid = "$Id: initgroups.c,v 1.4 1994/03/30 03:51:32 cgd Exp $";
37 #endif /* LIBC_SCCS and not lint */
38 
39 /*
40  * initgroups
41  */
42 #include <sys/param.h>
43 #include <stdio.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <grp.h>
47 
48 struct group *getgrent();
49 
50 int
51 initgroups(uname, agroup)
52 	const char *uname;
53 	int agroup;
54 {
55 	gid_t groups[NGROUPS];
56 	int ngroups = 0;
57 	register struct group *grp;
58 	register int i;
59 
60 	/*
61 	 * If installing primary group, duplicate it;
62 	 * the first element of groups is the effective gid
63 	 * and will be overwritten when a setgid file is executed.
64 	 */
65 	if (agroup >= 0) {
66 		groups[ngroups++] = agroup;
67 		groups[ngroups++] = agroup;
68 	}
69 	setgrent();
70 	while (grp = getgrent()) {
71 		if (grp->gr_gid == agroup)
72 			continue;
73 		for (i = 0; grp->gr_mem[i]; i++)
74 			if (!strcmp(grp->gr_mem[i], uname)) {
75 				if (ngroups == NGROUPS) {
76 fprintf(stderr, "initgroups: %s is in too many groups\n", uname);
77 					goto toomany;
78 				}
79 				groups[ngroups++] = grp->gr_gid;
80 			}
81 	}
82 toomany:
83 	endgrent();
84 	if (setgroups(ngroups, groups) < 0) {
85 		perror("setgroups");
86 		return (-1);
87 	}
88 	return (0);
89 }
90