/* Copyright (C) 1991,92,93,94,95,97,99,2001 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 <string.h>#include <unistd.h>#include <hurd.h>#include <hurd/port.h>/* Make PATH be the root directory (the starting point for absolute   paths).  Note that while on traditional UNIX systems this call is   restricted to the super-user, it isn't on the Hurd.  */intchroot (const char *path){  const char *lookup;  size_t len;  file_t dir, root;  error_t err;  /* Append trailing "/." to directory name to force ENOTDIR if it's not a     directory and EACCES if we don't have search permission.  */  len = strlen (path);  if (len >= 2 && path[len - 2] == '/' && path[len - 1] == '.')    lookup = path;  else    {      char *n = alloca (len + 3);      memcpy (n, path, len);      n[len] = '/';      n[len + 1] = '.';      n[len + 2] = '\0';      lookup = n;    }  dir = __file_name_lookup (lookup, 0, 0);  if (dir == MACH_PORT_NULL)    return -1;  /* Prevent going through DIR's ..  */  err = __file_reparent (dir, MACH_PORT_NULL, &root);  __mach_port_deallocate (__mach_task_self (), dir);  if (err)    return __hurd_fail (err);  _hurd_port_set (&_hurd_ports[INIT_PORT_CRDIR], root);  return 0;}