hurd/fchroot.c

   1 /* Copyright (C) 1999-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <unistd.h>
  19
  20 #include <hurd.h>
  21 #include <hurd/fd.h>
  22 #include <hurd/port.h>
  23
  24 /* Change the current root directory to FD.  */
  25 int
  26 fchroot (int fd)
  27 {
  28   error_t err;
  29   file_t dir;
  30
  31   err = HURD_DPORT_USE (fd,
  32                         ({
  33                           dir = __file_name_lookup_under (port, ".", 0, 0);
  34                           dir == MACH_PORT_NULL ? errno : 0;
  35                         }));
  36
  37   if (! err)
  38     {
  39       file_t root;
  40
  41       /* Prevent going through DIR's ..  */
  42       err = __file_reparent (dir, MACH_PORT_NULL, &root);
  43       __mach_port_deallocate (__mach_task_self (), dir);
  44       if (! err)
  45         _hurd_port_set (&_hurd_ports[INIT_PORT_CRDIR], root);
  46     }
  47
  48   return err ? __hurd_fail (err) : 0;
  49 }