#!/bin/sh
# Send mail if new IP comes in.

# based on WANIPCheck
# Checks your WAN IP-Address at a given interval and emails you the new IP-Address if changed
#
# Orig Created by CYBERDE for DD-WRT users ;) 
# --> http://www.dd-wrt.com/phpBB2/viewtopic.php?t=16041
# mod by Henning Mersch <mail@henning-mersch.de>

# Some settings
MAIL_BINARY=/jffs/bin/sendmail
MAIL_SERVER=SOMEMAILSERVER.TLD
MAIL_TO=SEND_TO_ADDR
MAIL_FROM=SEND_FROM_ADDR
MAIL_SUBJECT="New IP Notification"


# Function for sending the log to an email address
sendemail() {
   # Create the email message
   echo "Subject: $MAIL_SUBJECT"              > /tmp/mailnotification
   echo "WAN IP-Address has changed to: $1"  >> /tmp/mailnotification
   echo "Previous known WAN IP-Address: $2"  >> /tmp/mailnotification

   # Send the email message
   logger "$0: Sending email to $MAIL_TO"
   cat /tmp/mailnotification | $MAIL_BINARY -s$MAIL_SERVER -f$MAIL_FROM $MAIL_TO

   # Cleanup email message
   rm /tmp/mailnotification
}

# Does the nvram var wan_ipaddr_last exist?
if ! nvram show | grep -q wan_ipaddr_last; then
   nvram set wan_ipaddr_last=`nvram get wan_ipaddr`
   nvram commit
fi

# The "main" loop
CURR_WAN_IPADDR=`nvram get wan_ipaddr`
LAST_WAN_IPADDR=`nvram get wan_ipaddr_last`

# Send mail
sendemail $CURR_WAN_IPADDR $LAST_WAN_IPADDR

# Update the nvram variable to the current IP-Address
nvram set wan_ipaddr_last=$CURR_WAN_IPADDR
nvram commit