1: /* Copyright (C) 1996, 2001, 2004, 2006, 2007 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3: 
    4:    The GNU C Library is free software; you can redistribute it and/or
    5:    modify it under the terms of the GNU Lesser General Public
    6:    License as published by the Free Software Foundation; either
    7:    version 2.1 of the License, or (at your option) any later version.
    8: 
    9:    The GNU C Library is distributed in the hope that it will be useful,
   10:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   11:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   12:    Lesser General Public License for more details.
   13: 
   14:    You should have received a copy of the GNU Lesser General Public
   15:    License along with the GNU C Library; if not, write to the Free
   16:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   17:    02111-1307 USA.  */
   18: 
   19: #include <ctype.h>
   20: #include <errno.h>
   21: #include <stdio.h>
   22: #include <stdio_ext.h>
   23: #include <stdlib.h>
   24: #include <string.h>
   25: #include <bits/libc-lock.h>
   26: 
   27: #include <libnsl.h>
   28: 
   29: 
   30: /* Path of the file.  */
   31: static const char default_nss[] = "/etc/default/nss";
   32: 
   33: /* Flags once read from the file.  */
   34: static int default_nss_flags;
   35: 
   36: /* Code to make sure we call 'init' once.  */
   37: __libc_once_define (static, once);
   38: 
   39: /* Table of the recognized variables.  */
   40: static const struct
   41: {
   42:   char name[23];
   43:   unsigned int len;
   44:   int flag;
   45: } vars[] =
   46:   {
   47: #define STRNLEN(s) s, sizeof (s) - 1
   48:     { STRNLEN ("NETID_AUTHORITATIVE"), NSS_FLAG_NETID_AUTHORITATIVE },
   49:     { STRNLEN ("SERVICES_AUTHORITATIVE"), NSS_FLAG_SERVICES_AUTHORITATIVE },
   50:     { STRNLEN ("SETENT_BATCH_READ"), NSS_FLAG_SETENT_BATCH_READ }
   51:   };
   52: #define nvars (sizeof (vars) / sizeof (vars[0]))
   53: 
   54: 
   55: static void
   56: init (void)
   57: {
   58:   int saved_errno = errno;
   59:   FILE *fp = fopen (default_nss, "rc");
   60:   if (fp != NULL)
   61:     {
   62:       char *line = NULL;
   63:       size_t linelen = 0;
   64: 
   65:       __fsetlocking (fp, FSETLOCKING_BYCALLER);
   66: 
   67:       while (!feof_unlocked (fp))
   68:         {
   69:           ssize_t n = getline (&line, &linelen, fp);
   70:           if (n <= 0)
   71:             break;
   72: 
   73:           /* Recognize only
   74: 
   75:                <THE-VARIABLE> = TRUE
   76: 
   77:              with arbitrary white spaces.  */
   78:           char *cp = line;
   79:           while (isspace (*cp))
   80:             ++cp;
   81: 
   82:           /* Recognize comment lines.  */
   83:           if (*cp == '#')
   84:             continue;
   85: 
   86:           int idx;
   87:           for (idx = 0; idx < nvars; ++idx)
   88:             if (strncmp (cp, vars[idx].name, vars[idx].len) == 0)
   89:               break;
   90:           if (idx == nvars)
   91:             continue;
   92: 
   93:           cp += vars[idx].len;
   94:           while (isspace (*cp))
   95:             ++cp;
   96:           if (*cp++ != '=')
   97:             continue;
   98:           while (isspace (*cp))
   99:             ++cp;
  100: 
  101:           if (strncmp (cp, "TRUE", 4) != 0)
  102:             continue;
  103:           cp += 4;
  104: 
  105:           while (isspace (*cp))
  106:             ++cp;
  107: 
  108:           if (*cp == '\0')
  109:             default_nss_flags |= vars[idx].flag;
  110:         }
  111: 
  112:       free (line);
  113: 
  114:       fclose (fp);
  115:     }
  116:   __set_errno (saved_errno);
  117: }
  118: 
  119: 
  120: int
  121: _nsl_default_nss (void)
  122: {
  123:   /* If we have not yet read the file yet do it now.  */
  124:   __libc_once (once, init);
  125: 
  126:   return default_nss_flags;
  127: }