1#!/usr/bin/perl 2# 3# Copyright (C) Internet Systems Consortium, Inc. ("ISC") 4# 5# SPDX-License-Identifier: MPL-2.0 6# 7# This Source Code Form is subject to the terms of the Mozilla Public 8# License, v. 2.0. If a copy of the MPL was not distributed with this 9# file, you can obtain one at https://mozilla.org/MPL/2.0/. 10# 11# See the COPYRIGHT file distributed with this work for additional 12# information regarding copyright ownership. 13 14# A simple nanny to make sure named stays running. 15 16$pid_file_location = '/var/run/named.pid'; 17$nameserver_location = 'localhost'; 18$dig_program = 'dig'; 19$named_program = 'named'; 20 21fork() && exit(); 22 23for (;;) { 24 $pid = 0; 25 open(FILE, $pid_file_location) || goto restart; 26 $pid = <FILE>; 27 close(FILE); 28 chomp($pid); 29 30 $res = kill 0, $pid; 31 32 goto restart if ($res == 0); 33 34 $dig_command = 35 "$dig_program +short . \@$nameserver_location > /dev/null"; 36 $return = system($dig_command); 37 goto restart if ($return == 9); 38 39 sleep 30; 40 next; 41 42 restart: 43 if ($pid != 0) { 44 kill 15, $pid; 45 sleep 30; 46 } 47 system ($named_program); 48 sleep 120; 49} 50