nss/XXX-lookup.c

   1 /* Copyright (C) 1996-2022 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, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <assert.h>
  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. "files dns")     *|
  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_ID CONCAT2_1 (nss_database_, DATABASE_NAME)
  41 #define CONCAT2_1(Pre, Name) CONCAT2_2 (Pre, Name)
  42 #define CONCAT2_2(Pre, Name) Pre##Name
  43
  44 #define DATABASE_NAME_SYMBOL CONCAT3_1 (__nss_, DATABASE_NAME, _database)
  45 #define DATABASE_NAME_STRING STRINGIFY1 (DATABASE_NAME)
  46 #define STRINGIFY1(Name) STRINGIFY2 (Name)
  47 #define STRINGIFY2(Name) #Name
  48
  49 int
  50 DB_LOOKUP_FCT (nss_action_list *ni, const char *fct_name, const char *fct2_name,
  51                void **fctp)
  52 {
  53   if (! __nss_database_get (DATABASE_NAME_ID, &DATABASE_NAME_SYMBOL))
  54     return -1;
  55
  56   *ni = DATABASE_NAME_SYMBOL;
  57
  58   /* We want to know about it if we've somehow got a NULL action list;
  59    in the past, we had bad state if seccomp interfered with setup. */
  60   assert(*ni != NULL);
  61
  62   return __nss_lookup (ni, fct_name, fct2_name, fctp);
  63 }
  64 libc_hidden_def (DB_LOOKUP_FCT)