external/bsd/bind/dist/contrib/scripts/nanny.pl

   1 #!/usr/bin/perl
   2 #
   3 # Copyright (C) 2004, 2007, 2012, 2014  Internet Systems Consortium, Inc. ("ISC")
   4 # Copyright (C) 2000, 2001  Internet Software Consortium.
   5 #
   6 # Permission to use, copy, modify, and/or distribute this software for any
   7 # purpose with or without fee is hereby granted, provided that the above
   8 # copyright notice and this permission notice appear in all copies.
   9 #
  10 # THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  11 # REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  12 # AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  13 # INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  14 # LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  15 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  16 # PERFORMANCE OF THIS SOFTWARE.
  17
  18 # Id: nanny.pl,v 1.11 2007/06/19 23:47:07 tbox Exp
  19
  20 # A simple nanny to make sure named stays running.
  21
  22 $pid_file_location = '/var/run/named.pid';
  23 $nameserver_location = 'localhost';
  24 $dig_program = 'dig';
  25 $named_program =  'named';
  26
  27 fork() && exit();
  28
  29 for (;;) {
  30         $pid = 0;
  31         open(FILE, $pid_file_location) || goto restart;
  32         $pid = <FILE>;
  33         close(FILE);
  34         chomp($pid);
  35
  36         $res = kill 0, $pid;
  37
  38         goto restart if ($res == 0);
  39
  40         $dig_command =
  41                "$dig_program +short . \@$nameserver_location > /dev/null";
  42         $return = system($dig_command);
  43         goto restart if ($return == 9);
  44
  45         sleep 30;
  46         next;
  47
  48  restart:
  49         if ($pid != 0) {
  50                 kill 15, $pid;
  51                 sleep 30;
  52         }
  53         system ($named_program);
  54         sleep 120;
  55 }