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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)getusershell.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 /* $NetBSD: getusershell.c,v 1.17 1999/01/25 01:09:34 lukem Exp $ */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include "namespace.h" 42 #include <sys/param.h> 43 #include <sys/file.h> 44 45 #include <ctype.h> 46 #include <errno.h> 47 #include <nsswitch.h> 48 #include <paths.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <stringlist.h> 53 #include <unistd.h> 54 55 #ifdef HESIOD 56 #include <hesiod.h> 57 #endif 58 #ifdef YP 59 #include <rpc/rpc.h> 60 #include <rpcsvc/ypclnt.h> 61 #include <rpcsvc/yp_prot.h> 62 #endif 63 #include "un-namespace.h" 64 65 /* 66 * Local shells should NOT be added here. They should be added in 67 * /etc/shells. 68 */ 69 70 static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL }; 71 static const char *const *curshell; 72 static StringList *sl; 73 74 static const char *const *initshells(void); 75 76 /* 77 * Get a list of shells from "shells" nsswitch database 78 */ 79 char * 80 getusershell(void) 81 { 82 char *ret; 83 84 if (curshell == NULL) 85 curshell = initshells(); 86 /*LINTED*/ 87 ret = (char *)*curshell; 88 if (ret != NULL) 89 curshell++; 90 return (ret); 91 } 92 93 void 94 endusershell(void) 95 { 96 if (sl) { 97 sl_free(sl, 1); 98 sl = NULL; 99 } 100 curshell = NULL; 101 } 102 103 void 104 setusershell(void) 105 { 106 107 curshell = initshells(); 108 } 109 110 111 static int _local_initshells(void *, void *, va_list); 112 113 /*ARGSUSED*/ 114 static int 115 _local_initshells(rv, cb_data, ap) 116 void *rv; 117 void *cb_data; 118 va_list ap; 119 { 120 char *sp, *cp; 121 FILE *fp; 122 char line[MAXPATHLEN + 2]; 123 124 if (sl) 125 sl_free(sl, 1); 126 sl = sl_init(); 127 128 if ((fp = fopen(_PATH_SHELLS, "r")) == NULL) 129 return NS_UNAVAIL; 130 131 sp = cp = line; 132 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { 133 while (*cp != '#' && *cp != '/' && *cp != '\0') 134 cp++; 135 if (*cp == '#' || *cp == '\0') 136 continue; 137 sp = cp; 138 while (!isspace(*cp) && *cp != '#' && *cp != '\0') 139 cp++; 140 *cp++ = '\0'; 141 sl_add(sl, strdup(sp)); 142 } 143 (void)fclose(fp); 144 return NS_SUCCESS; 145 } 146 147 #ifdef HESIOD 148 static int _dns_initshells(void *, void *, va_list); 149 150 /*ARGSUSED*/ 151 static int 152 _dns_initshells(rv, cb_data, ap) 153 void *rv; 154 void *cb_data; 155 va_list ap; 156 { 157 char shellname[] = "shells-XXXXX"; 158 int hsindex, hpi, r; 159 char **hp; 160 void *context; 161 162 if (sl) 163 sl_free(sl, 1); 164 sl = sl_init(); 165 r = NS_UNAVAIL; 166 if (hesiod_init(&context) == -1) 167 return (r); 168 169 for (hsindex = 0; ; hsindex++) { 170 snprintf(shellname, sizeof(shellname)-1, "shells-%d", hsindex); 171 hp = hesiod_resolve(context, shellname, "shells"); 172 if (hp == NULL) { 173 if (errno == ENOENT) { 174 if (hsindex == 0) 175 r = NS_NOTFOUND; 176 else 177 r = NS_SUCCESS; 178 } 179 break; 180 } else { 181 for (hpi = 0; hp[hpi]; hpi++) 182 sl_add(sl, hp[hpi]); 183 free(hp); 184 } 185 } 186 hesiod_end(context); 187 return (r); 188 } 189 #endif /* HESIOD */ 190 191 #ifdef YP 192 static int _nis_initshells(void *, void *, va_list); 193 194 /*ARGSUSED*/ 195 static int 196 _nis_initshells(rv, cb_data, ap) 197 void *rv; 198 void *cb_data; 199 va_list ap; 200 { 201 static char *ypdomain; 202 char *key, *data; 203 char *lastkey; 204 int keylen, datalen; 205 int r; 206 207 if (sl) 208 sl_free(sl, 1); 209 sl = sl_init(); 210 211 if (ypdomain == NULL) { 212 switch (yp_get_default_domain(&ypdomain)) { 213 case 0: 214 break; 215 case YPERR_RESRC: 216 return NS_TRYAGAIN; 217 default: 218 return NS_UNAVAIL; 219 } 220 } 221 222 /* 223 * `key' and `data' point to strings dynamically allocated by 224 * the yp_... functions. 225 * `data' is directly put into the stringlist of shells. 226 */ 227 key = data = NULL; 228 if (yp_first(ypdomain, "shells", &key, &keylen, &data, &datalen)) 229 return NS_UNAVAIL; 230 do { 231 data[datalen] = '\0'; /* clear trailing \n */ 232 sl_add(sl, data); 233 234 lastkey = key; 235 r = yp_next(ypdomain, "shells", lastkey, keylen, 236 &key, &keylen, &data, &datalen); 237 free(lastkey); 238 } while (r == 0); 239 240 if (r == YPERR_NOMORE) { 241 /* 242 * `data' and `key' ought to be NULL - do not try to free them. 243 */ 244 return NS_SUCCESS; 245 } 246 247 return NS_UNAVAIL; 248 } 249 #endif /* YP */ 250 251 static const char *const * 252 initshells() 253 { 254 static const ns_dtab dtab[] = { 255 NS_FILES_CB(_local_initshells, NULL) 256 NS_DNS_CB(_dns_initshells, NULL) 257 NS_NIS_CB(_nis_initshells, NULL) 258 { 0 } 259 }; 260 if (sl) 261 sl_free(sl, 1); 262 sl = sl_init(); 263 264 if (_nsdispatch(NULL, dtab, NSDB_SHELLS, "initshells", __nsdefaultsrc) 265 != NS_SUCCESS) { 266 if (sl) 267 sl_free(sl, 1); 268 sl = NULL; 269 return (okshells); 270 } 271 sl_add(sl, NULL); 272 273 return (const char *const *)(sl->sl_str); 274 } 275