1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1985, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __SCCSID("@(#)getusershell.c 8.1 (Berkeley) 6/4/93");
34 __RCSID("$NetBSD: getusershell.c,v 1.17 1999/01/25 01:09:34 lukem Exp $");
35 __FBSDID("$FreeBSD$");
36
37 #include "namespace.h"
38 #include <sys/param.h>
39 #include <sys/file.h>
40
41 #include <ctype.h>
42 #include <errno.h>
43 #include <nsswitch.h>
44 #include <paths.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <stringlist.h>
49 #include <unistd.h>
50
51 #ifdef HESIOD
52 #include <hesiod.h>
53 #endif
54 #ifdef YP
55 #include <rpc/rpc.h>
56 #include <rpcsvc/ypclnt.h>
57 #include <rpcsvc/yp_prot.h>
58 #endif
59 #include "un-namespace.h"
60
61 static const char *const *curshell;
62 static StringList *sl;
63
64 static const char *const *initshells(void);
65
66 /*
67 * Get a list of shells from "shells" nsswitch database
68 */
69 char *
getusershell(void)70 getusershell(void)
71 {
72 char *ret;
73
74 if (curshell == NULL)
75 curshell = initshells();
76 /*LINTED*/
77 ret = (char *)*curshell;
78 if (ret != NULL)
79 curshell++;
80 return (ret);
81 }
82
83 void
endusershell(void)84 endusershell(void)
85 {
86 if (sl) {
87 sl_free(sl, 1);
88 sl = NULL;
89 }
90 curshell = NULL;
91 }
92
93 void
setusershell(void)94 setusershell(void)
95 {
96
97 curshell = initshells();
98 }
99
100
101 static int _local_initshells(void *, void *, va_list);
102
103 /*ARGSUSED*/
104 static int
_local_initshells(void * rv,void * cb_data,va_list ap)105 _local_initshells(void *rv, void *cb_data, va_list ap)
106 {
107 char *sp, *cp;
108 FILE *fp;
109 char line[MAXPATHLEN + 2];
110
111 if (sl)
112 sl_free(sl, 1);
113 sl = sl_init();
114
115 if ((fp = fopen(_PATH_SHELLS, "re")) == NULL)
116 return NS_UNAVAIL;
117
118 while (fgets(line, MAXPATHLEN + 1, fp) != NULL) {
119 cp = line;
120 while (*cp != '#' && *cp != '/' && *cp != '\0')
121 cp++;
122 if (*cp == '#' || *cp == '\0')
123 continue;
124 sp = cp;
125 while (!isspace(*cp) && *cp != '#' && *cp != '\0')
126 cp++;
127 *cp = '\0';
128 sl_add(sl, strdup(sp));
129 }
130 (void)fclose(fp);
131 return NS_SUCCESS;
132 }
133
134 #ifdef HESIOD
135 static int _dns_initshells(void *, void *, va_list);
136
137 /*ARGSUSED*/
138 static int
_dns_initshells(void * rv,void * cb_data,va_list ap)139 _dns_initshells(void *rv, void *cb_data, va_list ap)
140 {
141 char shellname[] = "shells-XXXXX";
142 int hsindex, hpi, r;
143 char **hp;
144 void *context;
145
146 if (sl)
147 sl_free(sl, 1);
148 sl = sl_init();
149 r = NS_UNAVAIL;
150 if (hesiod_init(&context) == -1)
151 return (r);
152
153 for (hsindex = 0; ; hsindex++) {
154 snprintf(shellname, sizeof(shellname)-1, "shells-%d", hsindex);
155 hp = hesiod_resolve(context, shellname, "shells");
156 if (hp == NULL) {
157 if (errno == ENOENT) {
158 if (hsindex == 0)
159 r = NS_NOTFOUND;
160 else
161 r = NS_SUCCESS;
162 }
163 break;
164 } else {
165 for (hpi = 0; hp[hpi]; hpi++)
166 sl_add(sl, hp[hpi]);
167 free(hp);
168 }
169 }
170 hesiod_end(context);
171 return (r);
172 }
173 #endif /* HESIOD */
174
175 #ifdef YP
176 static int _nis_initshells(void *, void *, va_list);
177
178 /*ARGSUSED*/
179 static int
_nis_initshells(void * rv,void * cb_data,va_list ap)180 _nis_initshells(void *rv, void *cb_data, va_list ap)
181 {
182 static char *ypdomain;
183 char *key, *data;
184 char *lastkey;
185 int keylen, datalen;
186 int r;
187
188 if (sl)
189 sl_free(sl, 1);
190 sl = sl_init();
191
192 if (ypdomain == NULL) {
193 switch (yp_get_default_domain(&ypdomain)) {
194 case 0:
195 break;
196 case YPERR_RESRC:
197 return NS_TRYAGAIN;
198 default:
199 return NS_UNAVAIL;
200 }
201 }
202
203 /*
204 * `key' and `data' point to strings dynamically allocated by
205 * the yp_... functions.
206 * `data' is directly put into the stringlist of shells.
207 */
208 key = data = NULL;
209 if (yp_first(ypdomain, "shells", &key, &keylen, &data, &datalen))
210 return NS_UNAVAIL;
211 do {
212 data[datalen] = '\0'; /* clear trailing \n */
213 sl_add(sl, data);
214
215 lastkey = key;
216 r = yp_next(ypdomain, "shells", lastkey, keylen,
217 &key, &keylen, &data, &datalen);
218 free(lastkey);
219 } while (r == 0);
220
221 if (r == YPERR_NOMORE) {
222 /*
223 * `data' and `key' ought to be NULL - do not try to free them.
224 */
225 return NS_SUCCESS;
226 }
227
228 return NS_UNAVAIL;
229 }
230 #endif /* YP */
231
232 static const char *const *
initshells(void)233 initshells(void)
234 {
235 static const ns_dtab dtab[] = {
236 NS_FILES_CB(_local_initshells, NULL)
237 NS_DNS_CB(_dns_initshells, NULL)
238 NS_NIS_CB(_nis_initshells, NULL)
239 { 0 }
240 };
241 if (sl)
242 sl_free(sl, 1);
243 sl = sl_init();
244
245 if (_nsdispatch(NULL, dtab, NSDB_SHELLS, "initshells", __nsdefaultsrc)
246 != NS_SUCCESS) {
247 if (sl)
248 sl_free(sl, 1);
249 sl = sl_init();
250 /*
251 * Local shells should NOT be added here. They should be
252 * added in /etc/shells.
253 */
254 sl_add(sl, strdup(_PATH_BSHELL));
255 sl_add(sl, strdup(_PATH_CSHELL));
256 }
257 sl_add(sl, NULL);
258
259 return (const char *const *)(sl->sl_str);
260 }
261