#!/bin/bash

################################ User Configuration Options ##########################
####### enter your user name
dyuser=test
####### enter your password
passwd=test
###### enter your hosts fully qualified domain name
fqdn=test1.customtest.dyndns.org
###### enter the system type - either custom, dyndns, or statdns
sys=custom
####### enter the polling frequency in seconds (remember < 5 minute updates is considered abuse - if you jump networks very frequently do not set below 5 min)
freq=325
####### enter the directory to put the temp and log files (you must have rights to log to this location)
logs=/usr/local/var/
####### enter the type of address you want to monitor - either internet or local
montype=local

################ return code parsing function ###############################
chkretcode ()
{
if [ "$status" = badauth ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Bad Authentication Credentials >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = badsys ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Bad System Paramater >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = badagent ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" User Agent Blocked >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = numhost ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Too many hosts >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = dnserr ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" DNS error encountered >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = 911 ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dyndns.org is experiencing critical problems >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = nohost ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" No such host in system >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = notfqdn ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Invalid host name format >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = !yours ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Not your host >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = abuse ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" System blocked due to abuse >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting >> "$logs"dyndns.log
exit
elif [ "$status" = good ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS Updated to Address "$current" >> "$logs"dyndns.log
echo "$current" > "$logs""$fqdn"
echo `date +%s` > "$logs""$fqdn""_time"
elif [ "$status" = nochg ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS has no change from Address "$current" >> "$logs"dyndns.log
echo "$current" > "$logs""$fqdn"
echo `date +%s` > "$logs""$fqdn""_time"
elif [ ! -n "$status" ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS service unavailable will try again in "$freq" >> "$logs"dyndns.log
elif [ "$status" = wait ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS service wants said wait will try again in "$freq" >> "$logs"dyndns.log
fi
}

################### Start-UP ########################
mkdir "$logs" 2> /dev/null
echo `date +%Y%m%d%H%M%S` "$fqdn" script starting >> "$logs"dyndns.log
echo "" > "$logs""$fqdn"
touch "$logs""$fqdn""_time"
l1=t
while [ "$l1" = t ]; do
l7=t
while [ "$l7" = t ]; do
if [ "$montype" = local ]; then
current=$(ipconfig getifaddr $(route get default 2> /dev/null |grep 'interface:' |awk '{print $2}') 2> /dev/null)
elif [ "$montype" = internet ]; then
current=$(curl -s http://adbas.net/cgi-bin/ip 2> /dev/null)
else
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting due to inappropriate address type entry >> "$logs"dyndns.log
exit
fi
if [ ! -n "$current" ]; then
sleep 180
else 
l7=f
fi
done
dns=`host "$fqdn" |awk '{print $4}'`
echo `date +%Y%m%d%H%M%S` "$fqdn" Checking address >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" current address is "$current" >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" DNS record points to address "$dns" >> "$logs"dyndns.log
if [ "$dns" = "$current" ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS does not require a change for Address "$current" >> "$logs"dyndns.log
echo "$current" > "$logs""$fqdn"
fi
lastip=`cat "$logs""$fqdn"`
if [ "$lastip" != "$current" ]; then
if [ "$dns" != "$current" ]; then

################### Initital Service Validation  and perform synchronization update ###############################
response=$(curl -s -k https://"$dyuser":"$passwd"@members.dyndns.org/nic/update?system="$sys"'&'hostname="$fqdn"'&'myip="$current" 2> /dev/null)
status=`echo "$response" | awk '{print $1}'`
ipad=`echo "$response" | awk '{print $2}'`
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS responded with the return code "$status" >> "$logs"dyndns.log
chkretcode
echo "$ipad" > "$logs""$fqdn"
fi
if [ "$dns" = "$lastip" ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS does not require a change for Address "$current" >> "$logs"dyndns.log
fi
fi
sleep "$freq"
l1=f
done

################### Continue Validating Service  perform synchronization updates ###############################
while [ "$l1" = f ]; do
l7=t
while [ "$l7" = t ]; do
if [ "$montype" = local ]; then
current=$(ipconfig getifaddr $(route get default 2> /dev/null |grep 'interface:' |awk '{print $2}') 2> /dev/null)
elif [ "$montype" = internet ]; then   
current=$(curl -s http://adbas.net/cgi-bin/ip 2> /dev/null)
else
echo `date +%Y%m%d%H%M%S` "$fqdn" script exiting due to inappropriate address type entry >> "$logs"dyndns.log
exit
fi
if [ ! -n "$current" ]; then
sleep 160
else      
l7=f
fi  
done
echo `date +%Y%m%d%H%M%S` "$fqdn" Checking address >> "$logs"dyndns.log
echo `date +%Y%m%d%H%M%S` "$fqdn" current address is "$current" >> "$logs"dyndns.log
lastip=`cat "$logs""$fqdn"`
if [ "$current" = "$lastip" ]; then
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS does not require a change from Address "$current" >> "$logs"dyndns.log
fi
if [ "$current" != "$lastip" ]; then
response=$(curl -s -k https://"$dyuser":"$passwd"@members.dyndns.org/nic/update?system="$sys"'&'hostname="$fqdn"'&'myip="$current" 2> /dev/null)
status=`echo "$response" | awk '{print $1}'`
ipad=`echo "$response" | awk '{print $2}'`
echo `date +%Y%m%d%H%M%S` "$fqdn" Dynamic DNS responded with the return code "$status" >> "$logs"dyndns.log
chkretcode
fi
sleep "$freq"
dat1=`date +%s`
dat2=`cat "$logs""$fqdn""_time"`
dat3=$((dat1-dat2))
if [ "$dat3" -gt 2332800 ]; then
echo 123 > "$logs""$fqdn""_time"
fi
done