/* Copyright (C) 1996-2018 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 <libc-lock.h>

#include <shadow.h>

#include <stdio.h>

#include <stdlib.h>

/* A reasonable size for a buffer to start with.  */

#define BUFLEN_SPWD 1024

/* We need to protect the dynamic buffer handling.  */

__libc_lock_define_initialized (static, lock);

libc_freeres_ptr (static char *buffer);

/* Read one shadow entry from the given stream.  */

struct spwd *

fgetspent (FILE *stream)

{

  static size_t buffer_size;

  static struct spwd resbuf;

  fpos_t pos;

  struct spwd *result;

  int save;

  if (fgetpos (stream, &pos) != 0)

    return NULL;

  /* Get lock.  */

  __libc_lock_lock (lock);

  /* Allocate buffer if not yet available.  */

  if (buffer == NULL)

    {

      buffer_size = BUFLEN_SPWD;

      buffer = malloc (buffer_size);

    }

  while (buffer != NULL

	 && (__fgetspent_r (stream, &resbuf, buffer, buffer_size, &result)

	     == ERANGE))

    {

      char *new_buf;

      buffer_size += BUFLEN_SPWD;

      new_buf = realloc (buffer, buffer_size);

      if (new_buf == NULL)

	{

	  /* We are out of memory.  Free the current buffer so that the

	     process gets a chance for a normal termination.  */

	  save = errno;

	  free (buffer);

	  __set_errno (save);

	}

      buffer = new_buf;

      /* Reset the stream.  */

      if (fsetpos (stream, &pos) != 0)

	buffer = NULL;

    }

  if (buffer == NULL)

    result = NULL;

  /* Release lock.  Preserve error value.  */

  save = errno;

  __libc_lock_unlock (lock);

  __set_errno (save);

  return result;

}