nss/XXX-lookup.c

   1 /* Copyright (C) 1996-2019 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "nsswitch.h"
  20
  21 /*******************************************************************\
  22 |* Here we assume one symbol to be defined:                        *|
  23 |*                                                                 *|
  24 |* DATABASE_NAME - name of the database the function accesses      *|
  25 |*                 (e.g., hosts, services, ...)                    *|
  26 |*                                                                 *|
  27 |* One additional symbol may optionally be defined:                *|
  28 |*                                                                 *|
  29 |* ALTERNATE_NAME - name of another service which is examined in   *|
  30 |*                  case DATABASE_NAME is not found                *|
  31 |*                                                                 *|
  32 |* DEFAULT_CONFIG - string for default conf (e.g. "dns files")     *|
  33 |*                                                                 *|
  34 \*******************************************************************/
  35
  36 #define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup2)
  37 #define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  38 #define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  39
  40 #define DATABASE_NAME_SYMBOL CONCAT3_1 (__nss_, DATABASE_NAME, _database)
  41 #define DATABASE_NAME_STRING STRINGIFY1 (DATABASE_NAME)
  42 #define STRINGIFY1(Name) STRINGIFY2 (Name)
  43 #define STRINGIFY2(Name) #Name
  44
  45 #ifdef ALTERNATE_NAME
  46 #define ALTERNATE_NAME_STRING STRINGIFY1 (ALTERNATE_NAME)
  47 #else
  48 #define ALTERNATE_NAME_STRING NULL
  49 #endif
  50
  51 #ifndef DEFAULT_CONFIG
  52 #define DEFAULT_CONFIG NULL
  53 #endif
  54
  55 int
  56 DB_LOOKUP_FCT (service_user **ni, const char *fct_name, const char *fct2_name,
  57                void **fctp)
  58 {
  59   if (DATABASE_NAME_SYMBOL == NULL
  60       && __nss_database_lookup2 (DATABASE_NAME_STRING, ALTERNATE_NAME_STRING,
  61                                  DEFAULT_CONFIG, &DATABASE_NAME_SYMBOL) < 0)
  62     return -1;
  63
  64   *ni = DATABASE_NAME_SYMBOL;
  65
  66   return __nss_lookup (ni, fct_name, fct2_name, fctp);
  67 }
  68 libc_hidden_def (DB_LOOKUP_FCT)