/* Common database routines for nss_db.

   Copyright (C) 2000-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   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, see

   <http://www.gnu.org/licenses/>.  */

#include <errno.h>

#include <fcntl.h>

#include <dlfcn.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/mman.h>

#include <not-cancel.h>

#include "nss_db.h"

/* Open the database stored in FILE.  If succesful, store either a

   pointer to the mapped file or a file handle for the file in H and

   return NSS_STATUS_SUCCESS.  On failure, return the appropriate

   lookup status.  */

enum nss_status

internal_setent (const char *file, struct nss_db_map *mapping)

{

  enum nss_status status = NSS_STATUS_UNAVAIL;

  int fd = __open_nocancel (file, O_RDONLY | O_LARGEFILE | O_CLOEXEC);

  if (fd != -1)

    {

      struct nss_db_header header;

      if (read (fd, &header, sizeof (header)) == sizeof (header))

	{

	  mapping->header = mmap (NULL, header.allocate, PROT_READ,

				  MAP_PRIVATE, fd, 0);

	  mapping->len = header.allocate;

	  if (mapping->header != MAP_FAILED)

	    status = NSS_STATUS_SUCCESS;

	  else if (errno == ENOMEM)

	    status = NSS_STATUS_TRYAGAIN;

	}

      __close_nocancel_nostatus (fd);

    }

  return status;

}

/* Close the database.  */

void

internal_endent (struct nss_db_map *mapping)

{

  munmap (mapping->header, mapping->len);

}