1/* $OpenBSD: groupaccess.c,v 1.17 2019/03/06 22:14:23 dtucker 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 <sys/types.h>
27
28#include <grp.h>
29#include <unistd.h>
30#include <stdarg.h>
31#include <stdlib.h>
32#include <string.h>
33#include <limits.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[NGROUPS_MAX + 1];	/* +1 for base/primary group */
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[NGROUPS_MAX + 1];
51	int i, j;
52	struct group *gr;
53
54	if (ngroups > 0)
55		ga_free();
56
57	ngroups = sizeof(groups_bygid) / sizeof(gid_t);
58	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
59		logit("getgrouplist: groups list too small");
60	for (i = 0, j = 0; i < ngroups; i++)
61		if ((gr = getgrgid(groups_bygid[i])) != NULL)
62			groups_byname[j++] = xstrdup(gr->gr_name);
63	return (ngroups = j);
64}
65
66/*
67 * Return 1 if one of user's groups is contained in groups.
68 * Return 0 otherwise.  Use match_pattern() for string comparison.
69 */
70int
71ga_match(char * const *groups, int n)
72{
73	int i, j;
74
75	for (i = 0; i < ngroups; i++)
76		for (j = 0; j < n; j++)
77			if (match_pattern(groups_byname[i], groups[j]))
78				return 1;
79	return 0;
80}
81
82/*
83 * Return 1 if one of user's groups matches group_pattern list.
84 * Return 0 on negated or no match.
85 */
86int
87ga_match_pattern_list(const char *group_pattern)
88{
89	int i, found = 0;
90
91	for (i = 0; i < ngroups; i++) {
92		switch (match_usergroup_pattern_list(groups_byname[i],
93		    group_pattern)) {
94		case -1:
95			return 0;	/* Negated match wins */
96		case 0:
97			continue;
98		case 1:
99			found = 1;
100		}
101	}
102	return found;
103}
104
105/*
106 * Free memory allocated for group access list.
107 */
108void
109ga_free(void)
110{
111	int i;
112
113	if (ngroups > 0) {
114		for (i = 0; i < ngroups; i++)
115			free(groups_byname[i]);
116		ngroups = 0;
117	}
118}
119