#!/bin/bash
#this script generates two zone files for two locally hosted domains.  
#it requires a valid, funtional account with dyndns.org, or a similar 
#dynamic dns service.  it is designed to allow a host to be its own 
#primary authoritative nameserver on a dynamic ip address.  your dnydns
#hostname must be listed as primary nameserver with your domain registrar.
#please modify the parameters of the zone files, below, to match your 
#local domain name, just as you would a regular zone file.  this script 
#placed in /etc/ppp/ip-up.d for ppp links or /etc/network/if-up.d/ for
#dhcp ethernet connections will allow auto updating of your dns entry.
#enjoy.  released under the GNU General Public Licence

ADDRESS="/var/dns/dns"
NUMBER=`cat /var/dns/dns`
OLD="/var/dns/dnsold"
OLDNUMBER=`cat $OLD`
SN="/var/dns/sn"
SERIAL=`cat $SN`

reset(){
echo "waiting 5 minutes and checking again..." >> /var/log/syslog
sleep 300
getip
}

getip(){
ip address show ppp0 | egrep -m 1 -o '[[:digit:]]+.[[:digit:]]+.[[:digit:]]+[.][[:digit:]]+ ' > /var/dns/dns
echo "ip=`cat /var/dns/dns`" >> /var/log/syslog
compip
}

compip(){

diff  /var/dns/dns /var/dns/dnsold
if [ "$?" = "0" ]; then
	echo "no change" >> /var/log/syslog
	reset
		else echo "address changed" >> /var/log/syslog
		incserial
fi
}

incserial(){

echo "incrementing zone file serial number" >> /var/log/syslog
((SERIAL++))
echo $SERIAL > $SN
writezone
}

writezone(){		

echo "writing new zone file" >> /var/log/syslog
echo '$ORIGIN'" net." > /etc/bind/db.gnuveaun
echo "gnuveau 300 IN SOA gnuveau.net. shogunx.sleekfreak.ath.cx. ( $SERIAL  600 300 600 600 )" >> /etc/bind/db.gnuveaun
echo "	    300       IN 	NS 	sleekfreak.ath.cx." >> /etc/bind/db.gnuveaun
echo "	    300       IN 	NS 	ns6.gandi.net." >> /etc/bind/db.gnuveaun
echo "	    300       IN 	MX 	100 mail.gnuveau.net." >> /etc/bind/db.gnuveaun
echo "	    300       IN 	A 	`cat /var/dns/dns`" >> /etc/bind/db.gnuveaun
echo "      300       IN        AAAA    3ffe:bc0:8000::4795" >> /etc/bind/db.gnuveaun
echo '$ORIGIN'" gnuveau.net." >> /etc/bind/db.gnuveaun
echo "mail 300	IN	A  `cat /var/dns/dns`" >> /etc/bind/db.gnuveaun
echo "www 300	IN	A   `cat /var/dns/dns`" >> /etc/bind/db.gnuveaun
echo "hello 300 IN	AAAA 3ffe:bc0:ce9:1:205:5dff:fe5b:ec0a" >> /etc/bind/db.gnuveaun


echo "new gnuveau.net zone file written" >> /var/log/syslog
writezone2
}

writezone2(){		

echo "writing new zone file" >> /var/log/syslog
echo '$ORIGIN'" com." > /etc/bind/db.gnuveauc
echo "gnuveau 300 IN SOA gnuveau.com. shogunx.sleekfreak.ath.cx. ( $SERIAL  600 300 600 600 )" >> /etc/bind/db.gnuveauc
echo "	    300       IN 	NS 	sleekfreak.ath.cx." >> /etc/bind/db.gnuveauc
echo "	    300       IN 	NS 	ns6.gandi.com." >> /etc/bind/db.gnuveauc
echo "	    300       IN 	MX 	100 mail.gnuveau.com." >> /etc/bind/db.gnuveauc
echo "	    300       IN 	A 	`cat /var/dns/dns`" >> /etc/bind/db.gnuveauc
echo "      300       IN        AAAA    3ffe:bc0:8000::4795" >> /etc/bind/db.gnuveauc
echo '$ORIGIN'" gnuveau.com." >> /etc/bind/db.gnuveauc
echo "mail 300	IN	A  `cat /var/dns/dns`" >> /etc/bind/db.gnuveauc
echo "www 300	IN	A   `cat /var/dns/dns`" >> /etc/bind/db.gnuveauc

echo "new gnuveau.com zone file written" >> /var/log/syslog

bindrestart
}

bindrestart(){

cp /var/dns/dns /var/dns/dnsold
/etc/init.d/bind9 restart
exit
}
sleep 30
getip