getgrouplist.c revision 1.19 1 /* $NetBSD: getgrouplist.c,v 1.19 2004/09/25 12:27:35 lukem Exp $ */
2
3 /*-
4 * Copyright (c) 2004 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Luke Mewburn.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 /*
40 * Copyright (c) 1991, 1993
41 * The Regents of the University of California. All rights reserved.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. Neither the name of the University nor the names of its contributors
52 * may be used to endorse or promote products derived from this software
53 * without specific prior written permission.
54 *
55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65 * SUCH DAMAGE.
66 */
67
68 #include <sys/cdefs.h>
69 #if defined(LIBC_SCCS) && !defined(lint)
70 #if 0
71 static char sccsid[] = "@(#)getgrouplist.c 8.2 (Berkeley) 12/8/94";
72 #else
73 __RCSID("$NetBSD: getgrouplist.c,v 1.19 2004/09/25 12:27:35 lukem Exp $");
74 #endif
75 #endif /* LIBC_SCCS and not lint */
76
77 /*
78 * calculate group access list
79 */
80
81 #include "namespace.h"
82 #include <sys/param.h>
83
84 #include <assert.h>
85 #include <errno.h>
86 #include <grp.h>
87 #include <nsswitch.h>
88 #include <stdarg.h>
89 #include <stdlib.h>
90 #include <string.h>
91 #include <unistd.h>
92
93 #ifdef HESIOD
94 #include <hesiod.h>
95 #endif
96
97 #ifdef __weak_alias
98 __weak_alias(getgrouplist,_getgrouplist)
99 #endif
100
101 #ifdef HESIOD
102
103 /*ARGSUSED*/
104 static int
105 _nss_dns_getgrouplist(void *retval, void *cb_data, va_list ap)
106 {
107 const char *uname = va_arg(ap, const char *);
108 gid_t agroup = va_arg(ap, gid_t);
109 gid_t *groups = va_arg(ap, gid_t *);
110 int *grpcnt = va_arg(ap, int *);
111
112 unsigned long id;
113 void *context;
114 char **hp, *cp, *ep;
115 int rv, ret, ngroups, maxgroups;
116
117 hp = NULL;
118 rv = NS_NOTFOUND;
119 ret = 0;
120
121 if (hesiod_init(&context) == -1) /* setup hesiod */
122 return NS_UNAVAIL;
123
124 hp = hesiod_resolve(context, uname, "grplist"); /* find grplist */
125 if (hp == NULL) {
126 if (errno != ENOENT)
127 rv = NS_NOTFOUND;
128 goto dnsgrouplist_out;
129 }
130
131 if ((ep = strchr(hp[0], '\n')) != NULL)
132 *ep = '\0'; /* clear trailing \n */
133
134 ret = 0;
135 ngroups = 0;
136 maxgroups = *grpcnt;
137
138 if (ngroups < maxgroups) /* add primary gid */
139 groups[ngroups] = agroup;
140 else
141 ret = -1;
142 ngroups++;
143
144 for (cp = hp[0]; *cp != '\0'; ) { /* parse grplist */
145 if ((cp = strchr(cp, ':')) == NULL) /* skip grpname */
146 break;
147 cp++;
148 id = strtoul(cp, &ep, 10); /* parse gid */
149 if (id > GID_MAX || (*ep != ':' && *ep != '\0')) {
150 rv = NS_UNAVAIL;
151 goto dnsgrouplist_out;
152 }
153 cp = ep;
154 if (*cp == ':')
155 cp++;
156 if (ngroups < maxgroups) /* add this gid */
157 groups[ngroups] = (gid_t)id;
158 else
159 ret = -1;
160 ngroups++;
161 }
162
163 *(int *)retval = ret;
164 *grpcnt = ngroups;
165 rv = NS_SUCCESS;
166
167 dnsgrouplist_out:
168 if (hp)
169 hesiod_free_list(context, hp);
170 hesiod_end(context);
171 return rv;
172 }
173
174 #endif /* HESIOD */
175
176 int
177 getgrouplist(const char *uname, gid_t agroup, gid_t *groups, int *grpcnt)
178 {
179 struct group *grp;
180 int i, ngroups, maxgroups, ret, glretval;
181
182 static const ns_dtab dtab[] = {
183 NS_DNS_CB(_nss_dns_getgrouplist, NULL)
184 { 0 }
185 };
186
187 _DIAGASSERT(uname != NULL);
188 _DIAGASSERT(groups != NULL);
189 _DIAGASSERT(grpcnt != NULL);
190
191 /* first, try source-specific optimized getgrouplist */
192 ret = nsdispatch(&glretval, dtab, NSDB_GROUP, "getgrouplist",
193 __nsdefaultsrc,
194 uname, agroup, groups, grpcnt);
195 if (ret == NS_SUCCESS)
196 return glretval;
197
198 /* fallback to scan the group(5) database */
199 ret = 0;
200 ngroups = 0;
201 maxgroups = *grpcnt;
202
203 /*
204 * install primary group
205 */
206 if (ngroups < maxgroups)
207 groups[ngroups] = agroup;
208 else
209 ret = -1;
210 ngroups++;
211
212 /*
213 * Scan the group file to find additional groups.
214 */
215 setgrent();
216 nextgroup:
217 while ((grp = getgrent()) != NULL) {
218 if (grp->gr_gid == agroup)
219 continue;
220 for (i = 0; grp->gr_mem[i]; i++) {
221 if (strcmp(grp->gr_mem[i], uname) != 0)
222 continue;
223 for (i = 0; i < MIN(ngroups, maxgroups); i++) {
224 if (grp->gr_gid == groups[i])
225 goto nextgroup;
226 }
227 if (ngroups < maxgroups)
228 groups[ngroups] = grp->gr_gid;
229 else
230 ret = -1;
231 ngroups++;
232 break;
233 }
234 }
235 endgrent();
236 *grpcnt = ngroups;
237 return ret;
238 }
239