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 <sys/param.h> 42 #include <sys/file.h> 43 44 #include <ctype.h> 45 #include <errno.h> 46 #include <nsswitch.h> 47 #include <paths.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <stringlist.h> 52 #include <unistd.h> 53 54 #ifdef HESIOD 55 #include <hesiod.h> 56 #endif 57 #ifdef YP 58 #include <rpc/rpc.h> 59 #include <rpcsvc/ypclnt.h> 60 #include <rpcsvc/yp_prot.h> 61 #endif 62 63 /* 64 * Local shells should NOT be added here. They should be added in 65 * /etc/shells. 66 */ 67 68 static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL }; 69 static const char *const *curshell; 70 static StringList *sl; 71 72 static const char *const *initshells(void); 73 74 /* 75 * Get a list of shells from "shells" nsswitch database 76 */ 77 char * 78 getusershell(void) 79 { 80 char *ret; 81 82 if (curshell == NULL) 83 curshell = initshells(); 84 /*LINTED*/ 85 ret = (char *)*curshell; 86 if (ret != NULL) 87 curshell++; 88 return (ret); 89 } 90 91 void 92 endusershell(void) 93 { 94 if (sl) { 95 sl_free(sl, 1); 96 sl = NULL; 97 } 98 curshell = NULL; 99 } 100 101 void 102 setusershell(void) 103 { 104 105 curshell = initshells(); 106 } 107 108 109 static int _local_initshells(void *, void *, va_list); 110 111 /*ARGSUSED*/ 112 static int 113 _local_initshells(rv, cb_data, ap) 114 void *rv; 115 void *cb_data; 116 va_list ap; 117 { 118 char *sp, *cp; 119 FILE *fp; 120 char line[MAXPATHLEN + 2]; 121 122 if (sl) 123 sl_free(sl, 1); 124 sl = sl_init(); 125 126 if ((fp = fopen(_PATH_SHELLS, "r")) == NULL) 127 return NS_UNAVAIL; 128 129 sp = cp = line; 130 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { 131 while (*cp != '#' && *cp != '/' && *cp != '\0') 132 cp++; 133 if (*cp == '#' || *cp == '\0') 134 continue; 135 sp = cp; 136 while (!isspace(*cp) && *cp != '#' && *cp != '\0') 137 cp++; 138 *cp++ = '\0'; 139 sl_add(sl, strdup(sp)); 140 } 141 (void)fclose(fp); 142 return NS_SUCCESS; 143 } 144 145 #ifdef HESIOD 146 static int _dns_initshells(void *, void *, va_list); 147 148 /*ARGSUSED*/ 149 static int 150 _dns_initshells(rv, cb_data, ap) 151 void *rv; 152 void *cb_data; 153 va_list ap; 154 { 155 char shellname[] = "shells-XXXXX"; 156 int hsindex, hpi, r; 157 char **hp; 158 void *context; 159 160 if (sl) 161 sl_free(sl, 1); 162 sl = sl_init(); 163 r = NS_UNAVAIL; 164 if (hesiod_init(&context) == -1) 165 return (r); 166 167 for (hsindex = 0; ; hsindex++) { 168 snprintf(shellname, sizeof(shellname)-1, "shells-%d", hsindex); 169 hp = hesiod_resolve(context, shellname, "shells"); 170 if (hp == NULL) { 171 if (errno == ENOENT) { 172 if (hsindex == 0) 173 r = NS_NOTFOUND; 174 else 175 r = NS_SUCCESS; 176 } 177 break; 178 } else { 179 for (hpi = 0; hp[hpi]; hpi++) 180 sl_add(sl, hp[hpi]); 181 free(hp); 182 } 183 } 184 hesiod_end(context); 185 return (r); 186 } 187 #endif /* HESIOD */ 188 189 #ifdef YP 190 static int _nis_initshells(void *, void *, va_list); 191 192 /*ARGSUSED*/ 193 static int 194 _nis_initshells(rv, cb_data, ap) 195 void *rv; 196 void *cb_data; 197 va_list ap; 198 { 199 static char *ypdomain; 200 char *key, *data; 201 char *lastkey; 202 int keylen, datalen; 203 int r; 204 205 if (sl) 206 sl_free(sl, 1); 207 sl = sl_init(); 208 209 if (ypdomain == NULL) { 210 switch (yp_get_default_domain(&ypdomain)) { 211 case 0: 212 break; 213 case YPERR_RESRC: 214 return NS_TRYAGAIN; 215 default: 216 return NS_UNAVAIL; 217 } 218 } 219 220 /* 221 * `key' and `data' point to strings dynamically allocated by 222 * the yp_... functions. 223 * `data' is directly put into the stringlist of shells. 224 */ 225 key = data = NULL; 226 if (yp_first(ypdomain, "shells", &key, &keylen, &data, &datalen)) 227 return NS_UNAVAIL; 228 do { 229 data[datalen] = '\0'; /* clear trailing \n */ 230 sl_add(sl, data); 231 232 lastkey = key; 233 r = yp_next(ypdomain, "shells", lastkey, keylen, 234 &key, &keylen, &data, &datalen); 235 free(lastkey); 236 } while (r == 0); 237 238 if (r == YPERR_NOMORE) { 239 /* 240 * `data' and `key' ought to be NULL - do not try to free them. 241 */ 242 return NS_SUCCESS; 243 } 244 245 return NS_UNAVAIL; 246 } 247 #endif /* YP */ 248 249 static const char *const * 250 initshells() 251 { 252 static const ns_dtab dtab[] = { 253 NS_FILES_CB(_local_initshells, NULL) 254 NS_DNS_CB(_dns_initshells, NULL) 255 NS_NIS_CB(_nis_initshells, NULL) 256 { 0 } 257 }; 258 if (sl) 259 sl_free(sl, 1); 260 sl = sl_init(); 261 262 if (nsdispatch(NULL, dtab, NSDB_SHELLS, "initshells", __nsdefaultsrc) 263 != NS_SUCCESS) { 264 if (sl) 265 sl_free(sl, 1); 266 sl = NULL; 267 return (okshells); 268 } 269 sl_add(sl, NULL); 270 271 return (const char *const *)(sl->sl_str); 272 } 273