/* Change a port cell to a directory in an open file descriptor.

   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 <errno.h>

#include <unistd.h>

#include <hurd.h>

#include <hurd/port.h>

#include <hurd/fd.h>

#include <fcntl.h>

int

_hurd_change_directory_port_from_fd (struct hurd_port *portcell, int fd)

{

  int ret;

  struct hurd_fd *d = _hurd_fd_get (fd);

  if (!d)

    return __hurd_fail (EBADF);

  HURD_CRITICAL_BEGIN;

  ret = HURD_PORT_USE (&d->port,

		       ({

			 int ret;

			 /* We look up "." to force ENOTDIR if it's not a

			    directory and EACCES if we don't have search

			    permission.  */

			 file_t dir = __file_name_lookup_under (port, ".",

								O_NOTRANS, 0);

			 if (dir == MACH_PORT_NULL)

			   ret = -1;

			 else

			   {

			     _hurd_port_set (portcell, dir);

			     ret = 0;

			   }

			 ret;

		       }));

  HURD_CRITICAL_END;

  return ret;

}