1  /* Copyright (C) 1999-2023 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     <https://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  }