1 /*
2 * Copyright (c) 1985, 1993
3 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)getusershell.c 8.1 (Berkeley) 6/4/93
30 * $NetBSD: getusershell.c,v 1.17 1999/01/25 01:09:34 lukem Exp $
31 * $FreeBSD: src/lib/libc/gen/getusershell.c,v 1.10 2007/01/09 00:27:54 imp Exp $
32 */
33
34 #include "namespace.h"
35 #include <sys/param.h>
36 #include <sys/file.h>
37
38 #include <ctype.h>
39 #include <errno.h>
40 #include <nsswitch.h>
41 #include <paths.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <stringlist.h>
46 #include <unistd.h>
47
48 #ifdef HESIOD
49 #include <hesiod.h>
50 #endif
51 #ifdef YP
52 #include <rpc/rpc.h>
53 #include <rpcsvc/ypclnt.h>
54 #include <rpcsvc/yp_prot.h>
55 #endif
56 #include "un-namespace.h"
57
58 /*
59 * Local shells should NOT be added here. They should be added in
60 * /etc/shells.
61 */
62
63 static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
64 static const char *const *curshell;
65 static StringList *sl;
66
67 static const char *const *initshells(void);
68
69 /*
70 * Get a list of shells from "shells" nsswitch database
71 */
72 char *
getusershell(void)73 getusershell(void)
74 {
75 char *ret;
76
77 if (curshell == NULL)
78 curshell = initshells();
79 /*LINTED*/
80 ret = (char *)*curshell;
81 if (ret != NULL)
82 curshell++;
83 return (ret);
84 }
85
86 void
endusershell(void)87 endusershell(void)
88 {
89 if (sl) {
90 sl_free(sl, 1);
91 sl = NULL;
92 }
93 curshell = NULL;
94 }
95
96 void
setusershell(void)97 setusershell(void)
98 {
99
100 curshell = initshells();
101 }
102
103
104 static int _local_initshells(void *, void *, va_list);
105
106 /*ARGSUSED*/
107 static int
_local_initshells(void * rv __unused,void * cb_data __unused,va_list ap __unused)108 _local_initshells(void *rv __unused, void *cb_data __unused,
109 va_list ap __unused)
110 {
111 char *sp, *cp;
112 FILE *fp;
113 char line[MAXPATHLEN + 2];
114
115 if (sl)
116 sl_free(sl, 1);
117 sl = sl_init();
118
119 if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
120 return NS_UNAVAIL;
121
122 sp = cp = line;
123 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
124 while (*cp != '#' && *cp != '/' && *cp != '\0')
125 cp++;
126 if (*cp == '#' || *cp == '\0')
127 continue;
128 sp = cp;
129 while (!isspace(*cp) && *cp != '#' && *cp != '\0')
130 cp++;
131 *cp++ = '\0';
132 sl_add(sl, strdup(sp));
133 }
134 fclose(fp);
135 return NS_SUCCESS;
136 }
137
138 #ifdef HESIOD
139 static int _dns_initshells(void *, void *, va_list);
140
141 /*ARGSUSED*/
142 static int
_dns_initshells(void * rv __unused,void * cb_data __unused,va_list ap __unused)143 _dns_initshells(void *rv __unused, void *cb_data __unused, va_list ap __unused)
144 {
145 char shellname[] = "shells-XXXXX";
146 int hsindex, hpi, r;
147 char **hp;
148 void *context;
149
150 if (sl)
151 sl_free(sl, 1);
152 sl = sl_init();
153 r = NS_UNAVAIL;
154 if (hesiod_init(&context) == -1)
155 return (r);
156
157 for (hsindex = 0; ; hsindex++) {
158 snprintf(shellname, sizeof(shellname)-1, "shells-%d", hsindex);
159 hp = hesiod_resolve(context, shellname, "shells");
160 if (hp == NULL) {
161 if (errno == ENOENT) {
162 if (hsindex == 0)
163 r = NS_NOTFOUND;
164 else
165 r = NS_SUCCESS;
166 }
167 break;
168 } else {
169 for (hpi = 0; hp[hpi]; hpi++)
170 sl_add(sl, hp[hpi]);
171 free(hp);
172 }
173 }
174 hesiod_end(context);
175 return (r);
176 }
177 #endif /* HESIOD */
178
179 #ifdef YP
180 static int _nis_initshells(void *, void *, va_list);
181
182 /*ARGSUSED*/
183 static int
_nis_initshells(void * rv __unused,void * cb_data __unused,va_list ap __unused)184 _nis_initshells(void *rv __unused, void *cb_data __unused, va_list ap __unused)
185 {
186 static char *ypdomain;
187 char *key, *data;
188 char *lastkey;
189 int keylen, datalen;
190 int r;
191
192 if (sl)
193 sl_free(sl, 1);
194 sl = sl_init();
195
196 if (ypdomain == NULL) {
197 switch (yp_get_default_domain(&ypdomain)) {
198 case 0:
199 break;
200 case YPERR_RESRC:
201 return NS_TRYAGAIN;
202 default:
203 return NS_UNAVAIL;
204 }
205 }
206
207 /*
208 * `key' and `data' point to strings dynamically allocated by
209 * the yp_... functions.
210 * `data' is directly put into the stringlist of shells.
211 */
212 key = data = NULL;
213 if (yp_first(ypdomain, "shells", &key, &keylen, &data, &datalen))
214 return NS_UNAVAIL;
215 do {
216 data[datalen] = '\0'; /* clear trailing \n */
217 sl_add(sl, data);
218
219 lastkey = key;
220 r = yp_next(ypdomain, "shells", lastkey, keylen,
221 &key, &keylen, &data, &datalen);
222 free(lastkey);
223 } while (r == 0);
224
225 if (r == YPERR_NOMORE) {
226 /*
227 * `data' and `key' ought to be NULL - do not try to free them.
228 */
229 return NS_SUCCESS;
230 }
231
232 return NS_UNAVAIL;
233 }
234 #endif /* YP */
235
236 static const char *const *
initshells(void)237 initshells(void)
238 {
239 static const ns_dtab dtab[] = {
240 NS_FILES_CB(_local_initshells, NULL)
241 NS_DNS_CB(_dns_initshells, NULL)
242 NS_NIS_CB(_nis_initshells, NULL)
243 { 0 }
244 };
245 if (sl)
246 sl_free(sl, 1);
247 sl = sl_init();
248
249 if (_nsdispatch(NULL, dtab, NSDB_SHELLS, "initshells", __nsdefaultsrc)
250 != NS_SUCCESS) {
251 if (sl)
252 sl_free(sl, 1);
253 sl = NULL;
254 return (okshells);
255 }
256 sl_add(sl, NULL);
257
258 return (const char *const *)(sl->sl_str);
259 }
260