/* Copyright (C) 1999-2018 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 <stdio.h>

#include <sys/socket.h>

#include <libc-lock.h>

/* Return a socket of any type.  The socket can be used in subsequent

   ioctl calls to talk to the kernel.  */

int

__opensock (void)

{

  /* Cache the last AF that worked, to avoid many redundant calls to

     socket().  */

  static int sock_af = -1;

  int fd = -1;

  __libc_lock_define_initialized (static, lock);

  if (sock_af != -1)

    {

      fd = __socket (sock_af, SOCK_DGRAM, 0);

      if (fd != -1)

        return fd;

    }

  __libc_lock_lock (lock);

  if (sock_af != -1)

    fd = __socket (sock_af, SOCK_DGRAM, 0);

  if (fd == -1)

    {

#ifdef AF_INET

      fd = __socket (sock_af = AF_INET, SOCK_DGRAM, 0);

#endif

#ifdef AF_INET6

      if (fd < 0)

	fd = __socket (sock_af = AF_INET6, SOCK_DGRAM, 0);

#endif

#ifdef AF_IPX

      if (fd < 0)

	fd = __socket (sock_af = AF_IPX, SOCK_DGRAM, 0);

#endif

#ifdef AF_AX25

      if (fd < 0)

	fd = __socket (sock_af = AF_AX25, SOCK_DGRAM, 0);

#endif

#ifdef AF_APPLETALK

      if (fd < 0)

	fd = __socket (sock_af = AF_APPLETALK, SOCK_DGRAM, 0);

#endif

    }

  __libc_lock_unlock (lock);

  return fd;

}