/* Make a link between file names relative to open directories.  Hurd version.   Copyright (C) 2006 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, write to the Free   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA   02111-1307 USA.  */#include <errno.h>#include <fcntl.h>#include <stddef.h>#include <unistd.h>#include <hurd.h>#include <hurd/fd.h>/* Make a link to FROM relative to FROMFD called TO relative to TOFD.  */intlinkat (fromfd, from, tofd, to, flags)     int fromfd;     const char *from;     int tofd;     const char *to;     int flags;{  error_t err;  file_t oldfile, linknode, todir;  char *toname;  oldfile = __file_name_lookup_at (fromfd, flags, from, 0, 0);  if (oldfile == MACH_PORT_NULL)    return -1;  /* The file_getlinknode RPC returns the port that should be passed to     the receiving filesystem (the one containing TODIR) in dir_link.  */  err = __file_getlinknode (oldfile, &linknode);  __mach_port_deallocate (__mach_task_self (), oldfile);  if (err)    return __hurd_fail (err);  todir = __file_name_split_at (tofd, to, &toname);  if (todir != MACH_PORT_NULL)    {      err = __dir_link (todir, linknode, toname, 1);      __mach_port_deallocate (__mach_task_self (), todir);    }  __mach_port_deallocate (__mach_task_self (), linknode);  if (todir == MACH_PORT_NULL)    return -1;  if (err)    return __hurd_fail (err);  return 0;}