sysdeps/mach/hurd/sethostid.c

   1 /* Copyright (C) 1993-2024 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 #include <hurd.h>
  20 #include "hurdhost.h"
  21 #include <_itoa.h>
  22
  23 /* Set the current machine's Internet number to ID.
  24    This call is restricted to the super-user.  */
  25 /* XXX should be __sethostid?
  26        isn't hostid supposed to be hardwired and unchangeable? */
  27 int
  28 sethostid (long int id)
  29 {
  30   char buf[8], *bp;
  31   ssize_t n;
  32
  33   /* The hostid is kept in the file /etc/hostid,
  34      eight characters of upper-case hexadecimal.  */
  35
  36   bp = _itoa_word (id, &buf[sizeof buf], 16, 1);
  37   while (bp > buf)
  38     *--bp = '0';
  39
  40   n = _hurd_set_host_config ("/etc/hostid", buf, sizeof buf);
  41   return n < 0 ? -1 : 0;
  42 }