Dynamic DNS Updater for Hurricane Electric with full v6 support and shit

dyndns.sh

#!/bin/bash

HOSTNAME=...
USERNAME=$HOSTNAME              # Hurricane Electric expects the username to be the hostname
PASSWORD=...
DEVICE=eth0

SAVEFILE=/var/run/ddns-lastip

function update {
	status=$(curl -u $USERNAME:$PASSWORD "http://dyn.dns.he.net/nic/update?hostname=$HOSTNAME&myip=$1&wildcard=NOCHG&mx=NOCHG&backmx=NOCHG")
	result=$(echo $status | awk '{print $1}')
	if [ $result == "good" ]; then
		echo "Successfully updated IP to $1"
		echo $1 > $SAVEFILE
	else
		echo "Updating IP to $1 gave us: $status"
	fi
}

myip=$(ip addr show eth0 | grep inet6 | awk '{print $2}' | cut -d'/' -f1 | head -n 1)


if [ "$(cat $SAVEFILE)" != "$myip" ]; then
	update $myip
fi