#!/usr/bin/env bash

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

function usage() {

        echo

        if [ -n "$1" ];then
           echo -e "Error: $1\n"
        fi
        echo -e ""
        echo -e "\tusage: `basename $0` < dyndns-name>\n"
        exit 1
}


[ $# -eq "0" -o $# -gt "2" ] && usage "wrong number of arguments"

DYNDNS_NAME=$1

_SKIP_IP=false




## - only run ddclient, if it is installed
## -
if [ ! -x "/usr/sbin/ddclient" ]; then
   exit 0
fi


if [ -f "/etc/ddclient.conf" ]; then

   ## - read variable "if" from configurationd file "/etc/ddclient.conf"
   ## -
   eval `sed -n 's/\(if=[^       ,]*\)/\1/p' /etc/ddclient.conf`

   ## - check if interface used by dyndns is present
   ##
   if [ -n "$if" ];then
      for _IFACE in `ifconfig | grep -e"^ppp" | cut -d" " -f1 `; do
         if [ "$_IFACE" = $if ];then
            PPP_IFACE=$_IFACE
            break
         fi
      done

      ## - exit if no connection for dydns interface exists
      ## -
      if [ "X" = "X$PPP_IFACE" ]; then
         echo "No interface for dydns exists. exiting now.."
         exit 0
      fi

   else
      _SKIP_IP=true
   fi
else
   ## - No configuration file found, so do not run
   ## -
   echo "No configuration file \"/etc/ddclient.conf\" found, so do not run"
   exit 0
fi


if ! $_SKIP_IP ; then
   PPP_REMOTE=`ifconfig  $PPP_IFACE 2>/dev/null | grep -e "P-[tz]-P" | cut -d":" -f3 | cut -d " " -f1`
   PPP_LOCAL=`ifconfig  $PPP_IFACE 2>/dev/null | grep -e "P-[tz]-P" | cut -d":" -f2 | cut -d " " -f1`
fi


if [ "X$PPP_REMOTE" != "X" -a "X$PPP_LOCAL" != "X" ] ; then

   if $_SKIP_IP ; then

      # Load defaults
      if [ -f /etc/default/ddclient ]; then
         
         source /etc/default/ddclient
         if [ "$run_daemon" = "true" ]; then
            exit 0
         fi
      fi

      /usr/sbin/ddclient

   else

      DYNDNS_IP=`dig $DYNDNS_NAME +short`
      #echo "$DYNDNS_NAME: $DYNDNS_IP - Local (PPP) IP: $PPP_LOCAL"

      if [ "$DYNDNS_IP" != "$PPP_LOCAL" ] ; then

         ## - Run ddclient with the IP address of the ppp device
         ## -
         echo "try to update ipadress entry at dyndns.org.."
         echo
         /usr/sbin/ddclient -syslog -ip $PPP_LOCAL
      fi

   fi

fi

exit 0;