lib/shells.c

   1 /*
   2  * SPDX-License-Identifier: GPL-2.0-or-later
   3  */
   4 #include <sys/syslog.h>
   5 #if defined (HAVE_LIBECONF) && defined (USE_VENDORDIR)
   6 #include <libeconf.h>
   7 #endif
   8
   9 #include "closestream.h"
  10 #include "shells.h"
  11
  12 /*
  13  *  is_known_shell() -- if the given shell appears in /etc/shells
  14  *  or vendor defined files.
  15  *  Return 1 if found and return 0 if not found.
  16  */
  17 extern int is_known_shell(const char *shell_name)
  18 {
  19         int ret = 0;
  20
  21 #if defined (HAVE_LIBECONF) && defined (USE_VENDORDIR)
  22         size_t size = 0;
  23         econf_err error;
  24         char **keys = NULL;
  25         econf_file *key_file = NULL;
  26
  27         error = econf_readDirs(&key_file,
  28                                _PATH_VENDORDIR,
  29                                "/etc",
  30                                "shells",
  31                                NULL,
  32                                "", /* key only */
  33                                "#" /* comment */);
  34         if (error) {
  35                 syslog(LOG_ALERT,
  36                        _("Cannot parse shells files: %s"),
  37                        econf_errString(error));
  38                 exit(EXIT_FAILURE);
  39         }
  40
  41         error = econf_getKeys(key_file, NULL, &size, &keys);
  42         if (error) {
  43                 syslog(LOG_ALERT,
  44                        _("Cannot evaluate entries in shells files: %s"),
  45                        econf_errString(error));
  46                 econf_free(key_file);
  47                 exit(EXIT_FAILURE);
  48         }
  49
  50         for (size_t i = 0; i < size; i++) {
  51                 if (strcmp(keys[i], shell_name) == 0) {
  52                         ret = 1;
  53                         break;
  54                 }
  55         }
  56         econf_free(keys);
  57         econf_free(key_file);
  58 #else
  59         char *s;
  60
  61         if (!shell_name)
  62                 return 0;
  63
  64         setusershell();
  65         while ((s = getusershell())) {
  66                 if (*s != '#' && strcmp(shell_name, s) == 0) {
  67                         ret = 1;
  68                         break;
  69                 }
  70         }
  71         endusershell();
  72 #endif
  73         return ret;
  74 }
  75