#!/bin/sh
#
# Update the nameserver cache information file once per month.
# This is run automatically by a cron entry.
#
# Original by Al Longyear
# Updated for BIND 8 by Nicolai Langfeldt
# Miscelanious error-conditions reported by David A. Ranch
# Ping test suggested by Martin Foster
# named up-test suggested by Erik Bryer.
#
(
 echo "To: hostmaster <hostmaster>"
 echo "From: system <root>"

 # Is named up? Check the status of named.
 case `rndc status 2>&1` in
    *refused*)
        echo "named is DOWN. db.root was NOT updated"
        echo
        exit 0
        ;;
 esac

 PATH=/sbin:/usr/sbin:/bin:/usr/bin:
 export PATH
 # NOTE: /var/named must be writable only by trusted users or this 
 #script 
 # will cause root compromise/denial of service opportunities.
 cd /etc/bind 2>/dev/null || {
    echo "Subject: Cannot cd to /etc/bind, error $?"
    echo
    echo "The subject says it all"
    exit 1
 }

 # Are we online?  Ping a server at your ISP
 case `ping -qnc 1 212.100.160.51 2>&1` in
   *'100% packet loss'*)
        echo "Subject: db.root NOT updated.  The network is DOWN."
        echo
        echo "The subject says it all"
        exit 1
        ;;
 esac

 dig @e.root-servers.net . ns >db.root.new 2> errors

 case `cat db.root.new` in
   *NOERROR*)
        # It worked
        :;;
   *)
        echo "Subject: The db.root file update has FAILED."
        echo
        echo "The db.root update has failed"
        echo "This is the dig output reported:"
        echo
        cat db.root.new errors
        exit 1
        ;;
 esac

 echo "Subject: The root.hints file has been updated"
 echo
 echo "The root.hints file has been updated to contain the following information:"
 echo
 cat db.root.new

 chown root.root db.root.new
 chmod 444 db.root.new
 rm -f db.root.old errors
 mv db.root db.root.old
 mv db.root.new db.root
 /etc/init.d/bind9 restart
 echo
 echo "The nameserver has been restarted to ensure that the update is complete."
 echo "The previous root.hints file is now called /etc/bind/db.root.old.") 2>&1 | /usr/lib/sendmail -t
exit 0