groupaccess.c revision 162852 
1/* $OpenBSD: groupaccess.c,v 1.12 2006/08/03 03:34:42 deraadt Exp $ */
2/*
3 * Copyright (c) 2001 Kevin Steves.  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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27
28#include <sys/types.h>
29#include <sys/param.h>
30
31#include <grp.h>
32#include <unistd.h>
33#include <stdarg.h>
34
35#include "xmalloc.h"
36#include "groupaccess.h"
37#include "match.h"
38#include "log.h"
39
40static int ngroups;
41static char **groups_byname;
42
43/*
44 * Initialize group access list for user with primary (base) and
45 * supplementary groups.  Return the number of groups in the list.
46 */
47int
48ga_init(const char *user, gid_t base)
49{
50	gid_t *groups_bygid;
51	int i, j;
52	struct group *gr;
53
54	if (ngroups > 0)
55		ga_free();
56
57	ngroups = NGROUPS_MAX;
58#if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
59	ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
60#endif
61
62	groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
63	groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
64
65	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
66		logit("getgrouplist: groups list too small");
67	for (i = 0, j = 0; i < ngroups; i++)
68		if ((gr = getgrgid(groups_bygid[i])) != NULL)
69			groups_byname[j++] = xstrdup(gr->gr_name);
70	xfree(groups_bygid);
71	return (ngroups = j);
72}
73
74/*
75 * Return 1 if one of user's groups is contained in groups.
76 * Return 0 otherwise.  Use match_pattern() for string comparison.
77 */
78int
79ga_match(char * const *groups, int n)
80{
81	int i, j;
82
83	for (i = 0; i < ngroups; i++)
84		for (j = 0; j < n; j++)
85			if (match_pattern(groups_byname[i], groups[j]))
86				return 1;
87	return 0;
88}
89
90/*
91 * Free memory allocated for group access list.
92 */
93void
94ga_free(void)
95{
96	int i;
97
98	if (ngroups > 0) {
99		for (i = 0; i < ngroups; i++)
100			xfree(groups_byname[i]);
101		ngroups = 0;
102		xfree(groups_byname);
103	}
104}
105