1/* $OpenBSD: groupaccess.c,v 1.13 2008/07/04 03:44:59 djm 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#include <string.h>
35
36#include "xmalloc.h"
37#include "groupaccess.h"
38#include "match.h"
39#include "log.h"
40
41static int ngroups;
42static char **groups_byname;
43
44/*
45 * Initialize group access list for user with primary (base) and
46 * supplementary groups.  Return the number of groups in the list.
47 */
48int
49ga_init(const char *user, gid_t base)
50{
51#ifdef ANDROID
52	return 0;
53#else
54	gid_t *groups_bygid;
55	int i, j;
56	struct group *gr;
57
58	if (ngroups > 0)
59		ga_free();
60
61	ngroups = NGROUPS_MAX;
62#if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
63	ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
64#endif
65
66	groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
67	groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
68
69	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
70		logit("getgrouplist: groups list too small");
71	for (i = 0, j = 0; i < ngroups; i++)
72		if ((gr = getgrgid(groups_bygid[i])) != NULL)
73			groups_byname[j++] = xstrdup(gr->gr_name);
74	xfree(groups_bygid);
75	return (ngroups = j);
76#endif
77}
78
79/*
80 * Return 1 if one of user's groups is contained in groups.
81 * Return 0 otherwise.  Use match_pattern() for string comparison.
82 */
83int
84ga_match(char * const *groups, int n)
85{
86	int i, j;
87
88	for (i = 0; i < ngroups; i++)
89		for (j = 0; j < n; j++)
90			if (match_pattern(groups_byname[i], groups[j]))
91				return 1;
92	return 0;
93}
94
95/*
96 * Return 1 if one of user's groups matches group_pattern list.
97 * Return 0 on negated or no match.
98 */
99int
100ga_match_pattern_list(const char *group_pattern)
101{
102	int i, found = 0;
103	size_t len = strlen(group_pattern);
104
105	for (i = 0; i < ngroups; i++) {
106		switch (match_pattern_list(groups_byname[i],
107		    group_pattern, len, 0)) {
108		case -1:
109			return 0;	/* Negated match wins */
110		case 0:
111			continue;
112		case 1:
113			found = 1;
114		}
115	}
116	return found;
117}
118
119/*
120 * Free memory allocated for group access list.
121 */
122void
123ga_free(void)
124{
125	int i;
126
127	if (ngroups > 0) {
128		for (i = 0; i < ngroups; i++)
129			xfree(groups_byname[i]);
130		ngroups = 0;
131		xfree(groups_byname);
132	}
133}
134