nss/XXX-lookup.c

   1 /* Copyright (C) 1996, 1997, 1999, 2000, 2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include "nsswitch.h"
  21
  22 /*******************************************************************\
  23 |* Here we assume one symbol to be defined:                        *|
  24 |*                                                                 *|
  25 |* DATABASE_NAME - name of the database the function accesses      *|
  26 |*                 (e.g., hosts, services, ...)                    *|
  27 |*                                                                 *|
  28 |* One additional symbol may optionally be defined:                *|
  29 |*                                                                 *|
  30 |* ALTERNATE_NAME - name of another service which is examined in   *|
  31 |*                  case DATABASE_NAME is not found                *|
  32 |*                                                                 *|
  33 |* DEFAULT_CONFIG - string for default conf (e.g. "dns files")     *|
  34 |*                                                                 *|
  35 \*******************************************************************/
  36
  37 #define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup)
  38 #define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  39 #define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  40
  41 #define DATABASE_NAME_SYMBOL CONCAT3_1 (__nss_, DATABASE_NAME, _database)
  42 #define DATABASE_NAME_STRING STRINGIFY1 (DATABASE_NAME)
  43 #define STRINGIFY1(Name) STRINGIFY2 (Name)
  44 #define STRINGIFY2(Name) #Name
  45
  46 #ifdef ALTERNATE_NAME
  47 #define ALTERNATE_NAME_STRING STRINGIFY1 (ALTERNATE_NAME)
  48 #else
  49 #define ALTERNATE_NAME_STRING NULL
  50 #endif
  51
  52 #ifndef DEFAULT_CONFIG
  53 #define DEFAULT_CONFIG NULL
  54 #endif
  55
  56 service_user *DATABASE_NAME_SYMBOL attribute_hidden;
  57
  58 extern int DB_LOOKUP_FCT (service_user **ni, const char *fct_name,
  59                           void **fctp) internal_function;
  60 libc_hidden_proto (DB_LOOKUP_FCT)
  61
  62 int
  63 internal_function
  64 DB_LOOKUP_FCT (service_user **ni, const char *fct_name, void **fctp)
  65 {
  66   if (DATABASE_NAME_SYMBOL == NULL
  67       && __nss_database_lookup (DATABASE_NAME_STRING, ALTERNATE_NAME_STRING,
  68                                 DEFAULT_CONFIG, &DATABASE_NAME_SYMBOL) < 0)
  69     return -1;
  70
  71   *ni = DATABASE_NAME_SYMBOL;
  72
  73   return __nss_lookup (ni, fct_name, fctp);
  74 }
  75 libc_hidden_def (DB_LOOKUP_FCT)