/* Copyright (C) 1992-2018 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 <sys/socket.h>

#include <sys/stat.h>

#include <unistd.h>

#include <fcntl.h>

#include <fcntl-internal.h>

#include <hurd.h>

/* Create a one-way communication channel (pipe).

   Actually the channel is two-way on the Hurd.

   If successful, two file descriptors are stored in FDS;

   bytes written on FDS[1] can be read from FDS[0].

   Apply FLAGS to the new file descriptors.

   Returns 0 if successful, -1 if not.  */

int

__pipe2 (int fds[2], int flags)

{

  int save_errno = errno;

  int result;

  if (flags & ~(O_CLOEXEC | O_NONBLOCK))

    return __hurd_fail (EINVAL);

  flags = o_to_sock_flags (flags);

  /* The magic S_IFIFO protocol tells the pflocal server to create

     sockets which report themselves as FIFOs, as POSIX requires for

     pipes.  */

  result = __socketpair (PF_LOCAL, SOCK_STREAM | flags, S_IFIFO, fds);

  if (result == -1 && errno == EPROTONOSUPPORT)

    {

      /* We contacted an "old" pflocal server that doesn't support the

         magic S_IFIFO protocol.

	 FIXME: Remove this junk somewhere in the future.  */

      __set_errno (save_errno);

      return __socketpair (PF_LOCAL, SOCK_STREAM | flags, 0, fds);

    }

  return result;

}

weak_alias (__pipe2, pipe2)