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 __RCSID("$NetBSD: getusershell.c,v 1.17 1999/01/25 01:09:34 lukem Exp $");
34
35 #include "namespace.h"
36 #include <sys/param.h>
37 #include <sys/file.h>
38
39 #include <ctype.h>
40 #include <errno.h>
41 #include <nsswitch.h>
42 #include <paths.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <stringlist.h>
47 #include <unistd.h>
48
49 #ifdef HESIOD
50 #include <hesiod.h>
51 #endif
52 #ifdef YP
53 #include <rpc/rpc.h>
54 #include <rpcsvc/ypclnt.h>
55 #include <rpcsvc/yp_prot.h>
56 #endif
57 #include "un-namespace.h"
58
59 static const char *const *curshell;
60 static StringList *sl;
61
62 static const char *const *initshells(void);
63
64 /*
65 * Get a list of shells from "shells" nsswitch database
66 */
67 char *
getusershell(void)68 getusershell(void)
69 {
70 char *ret;
71
72 if (curshell == NULL)
73 curshell = initshells();
74 /*LINTED*/
75 ret = (char *)*curshell;
76 if (ret != NULL)
77 curshell++;
78 return (ret);
79 }
80
81 void
endusershell(void)82 endusershell(void)
83 {
84 if (sl) {
85 sl_free(sl, 1);
86 sl = NULL;
87 }
88 curshell = NULL;
89 }
90
91 void
setusershell(void)92 setusershell(void)
93 {
94
95 curshell = initshells();
96 }
97
98
99 static int _local_initshells(void *, void *, va_list);
100
101 /*ARGSUSED*/
102 static int
_local_initshells(void * rv,void * cb_data,va_list ap)103 _local_initshells(void *rv, void *cb_data, va_list ap)
104 {
105 char *sp, *cp;
106 FILE *fp;
107 char line[MAXPATHLEN + 2];
108
109 if (sl)
110 sl_free(sl, 1);
111 sl = sl_init();
112
113 if ((fp = fopen(_PATH_SHELLS, "re")) == NULL)
114 return NS_UNAVAIL;
115
116 while (fgets(line, MAXPATHLEN + 1, fp) != NULL) {
117 cp = line;
118 while (*cp != '#' && *cp != '/' && *cp != '\0')
119 cp++;
120 if (*cp == '#' || *cp == '\0')
121 continue;
122 sp = cp;
123 while (!isspace(*cp) && *cp != '#' && *cp != '\0')
124 cp++;
125 *cp = '\0';
126 sl_add(sl, strdup(sp));
127 }
128 (void)fclose(fp);
129 return NS_SUCCESS;
130 }
131
132 #ifdef HESIOD
133 static int _dns_initshells(void *, void *, va_list);
134
135 /*ARGSUSED*/
136 static int
_dns_initshells(void * rv,void * cb_data,va_list ap)137 _dns_initshells(void *rv, void *cb_data, va_list ap)
138 {
139 char shellname[] = "shells-XXXXX";
140 int hsindex, hpi, r;
141 char **hp;
142 void *context;
143
144 if (sl)
145 sl_free(sl, 1);
146 sl = sl_init();
147 r = NS_UNAVAIL;
148 if (hesiod_init(&context) == -1)
149 return (r);
150
151 for (hsindex = 0; ; hsindex++) {
152 snprintf(shellname, sizeof(shellname)-1, "shells-%d", hsindex);
153 hp = hesiod_resolve(context, shellname, "shells");
154 if (hp == NULL) {
155 if (errno == ENOENT) {
156 if (hsindex == 0)
157 r = NS_NOTFOUND;
158 else
159 r = NS_SUCCESS;
160 }
161 break;
162 } else {
163 for (hpi = 0; hp[hpi]; hpi++)
164 sl_add(sl, hp[hpi]);
165 free(hp);
166 }
167 }
168 hesiod_end(context);
169 return (r);
170 }
171 #endif /* HESIOD */
172
173 #ifdef YP
174 static int _nis_initshells(void *, void *, va_list);
175
176 /*ARGSUSED*/
177 static int
_nis_initshells(void * rv,void * cb_data,va_list ap)178 _nis_initshells(void *rv, void *cb_data, va_list ap)
179 {
180 static char *ypdomain;
181 char *key, *data;
182 char *lastkey;
183 int keylen, datalen;
184 int r;
185
186 if (sl)
187 sl_free(sl, 1);
188 sl = sl_init();
189
190 if (ypdomain == NULL) {
191 switch (yp_get_default_domain(&ypdomain)) {
192 case 0:
193 break;
194 case YPERR_RESRC:
195 return NS_TRYAGAIN;
196 default:
197 return NS_UNAVAIL;
198 }
199 }
200
201 /*
202 * `key' and `data' point to strings dynamically allocated by
203 * the yp_... functions.
204 * `data' is directly put into the stringlist of shells.
205 */
206 key = data = NULL;
207 if (yp_first(ypdomain, "shells", &key, &keylen, &data, &datalen))
208 return NS_UNAVAIL;
209 do {
210 data[datalen] = '\0'; /* clear trailing \n */
211 sl_add(sl, data);
212
213 lastkey = key;
214 r = yp_next(ypdomain, "shells", lastkey, keylen,
215 &key, &keylen, &data, &datalen);
216 free(lastkey);
217 } while (r == 0);
218
219 if (r == YPERR_NOMORE) {
220 /*
221 * `data' and `key' ought to be NULL - do not try to free them.
222 */
223 return NS_SUCCESS;
224 }
225
226 return NS_UNAVAIL;
227 }
228 #endif /* YP */
229
230 static const char *const *
initshells(void)231 initshells(void)
232 {
233 static const ns_dtab dtab[] = {
234 NS_FILES_CB(_local_initshells, NULL)
235 NS_DNS_CB(_dns_initshells, NULL)
236 NS_NIS_CB(_nis_initshells, NULL)
237 { 0 }
238 };
239 if (sl)
240 sl_free(sl, 1);
241 sl = sl_init();
242
243 if (_nsdispatch(NULL, dtab, NSDB_SHELLS, "initshells", __nsdefaultsrc)
244 != NS_SUCCESS) {
245 if (sl)
246 sl_free(sl, 1);
247 sl = sl_init();
248 /*
249 * Local shells should NOT be added here. They should be
250 * added in /etc/shells.
251 */
252 sl_add(sl, strdup(_PATH_BSHELL));
253 sl_add(sl, strdup(_PATH_CSHELL));
254 }
255 sl_add(sl, NULL);
256
257 return (const char *const *)(sl->sl_str);
258 }
259