lib/libc/gen/getusershell.c

   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 *
  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
  87 endusershell(void)
  88 {
  89         if (sl) {
  90                 sl_free(sl, 1);
  91                 sl = NULL;
  92         }
  93         curshell = NULL;
  94 }
  95
  96 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
 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
 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
 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 *
 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 }