path: root/nss/nsswitch.c

/* Copyright (C) 1996-1999, 2001-2007, 2009 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <netdb.h>
#include <bits/libc-lock.h>
#include <search.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>

#include <aliases.h>
#include <grp.h>
#include <netinet/ether.h>
#include <pwd.h>
#include <shadow.h>

#if !defined DO_STATIC_NSS || defined SHARED
# include <gnu/lib-names.h>
#endif

#include "nsswitch.h"
#include "../nscd/nscd_proto.h"

/* Prototypes for the local functions.  */
static name_database *nss_parse_file (const char *fname) internal_function;
static name_database_entry *nss_getline (char *line) internal_function;
static service_user *nss_parse_service_list (const char *line)
     internal_function;
static service_library *nss_new_service (name_database *database,
					 const char *name) internal_function;


/* Declare external database variables.  */
#define DEFINE_DATABASE(name)						      \
  extern service_user *__nss_##name##_database attribute_hidden;	      \
  weak_extern (__nss_##name##_database)
#include "databases.def"
#undef DEFINE_DATABASE

/* Structure to map database name to variable.  */
static const struct
{
  const char name[10];
  service_user **dbp;
} databases[] =
{
#define DEFINE_DATABASE(name)						      \
  { #name, &__nss_##name##_database },
#include "databases.def"
#undef DEFINE_DATABASE
};
#define ndatabases (sizeof (databases) / sizeof (databases[0]))


__libc_lock_define_initialized (static, lock)

#if !defined DO_STATIC_NSS || defined SHARED
/* String with revision number of the shared object files.  */
static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
#endif

/* The root of the whole data base.  */
static name_database *service_table;


/* -1 == database not found
    0 == database entry pointer stored */
int
__nss_database_lookup (const char *database, const char *alternate_name,
		       const char *defconfig, service_user **ni)
{
  /* Prevent multiple threads to change the service table.  */
  __libc_lock_lock (lock);

  /* Reconsider database variable in case some other thread called
     `__nss_configure_lookup' while we waited for the lock.  */
  if (*ni != NULL)
    {
      __libc_lock_unlock (lock);
      return 0;
    }

  /* Are we initialized yet?  */
  if (service_table == NULL)