#!/bin/sh

# Script to poll ADSL at sane intervals and switch to dialup
# service if necessary

# Setup main path
ADSLROOT=/root/adslswitch

# Setup programs
PING=/bin/ping
IFUP=/sbin/ifup
IFDOWN=/sbin/ifdown
KILL=/bin/kill
KILLALL=/usr/bin/killall
PPPD=/usr/sbin/pppd
PIDOF=/sbin/pidof
ADSLSTART=/usr/sbin/adsl-start
ADSLSTOP=/usr/sbin/adsl-stop
SLEEP=/bin/sleep

# Set default wait time between loops
WAITTIME="1m"
# Set Connection up test command
CONNUP="$PING -w 10 -c 2 61.8.0.113"
# Set the "test if adsl is up" command
ADSLUP="$PIDOF pppoe"

# Change to ADSLSwitch root
cd $ADSLROOT

while [ 1 -eq 1 ]
do
  # Loop until otherwise notified
  DATE=`/bin/date`

  # Write timestamp to log
  echo "---- Testing ADSL at $DATE ----" >> adslswitch.log

  # Check if adsl is currently up

  if $ADSLUP && $CONNUP; then
    echo " * ADSL is up and working. Not doing anything..." >> adslswitch.log
    echo "---- Test Completed ---" >> adslswitch.log
    echo "*** SLEEPING FOR $WAITTIME ***" >> adslswitch.log
  else
    # Firstly, kill ADSL connection 
    echo " * ADSL currently not working. Performing test..." >> adslswitch.log
    echo " * Killing current connection..." >> adslswitch.log
    $KILLALL pppd 2>> /dev/null
    $ADSLSTOP 2>> /dev/null
    $KILLALL pppoe 2>> /dev/null
    $KILLALL -9 pppd 2>> /dev/null
    $KILLALL -9 pppoe 2>> /dev/null
    $IFDOWN ppp0 2>> /dev/null 

    # Dial ADSL connection
    echo " * Attempting to reconnect to ADSL..." >> adslswitch.log
    $ADSLSTART 2>> adslswitch.log

    # Ok, nested loop here is messy - I'll neaten it later

    if $CONNUP; then
      echo " * ADSL connection successfully established and working." >> adslswitch.log
      WAITTIME="1m"
      echo "---- ADSL test completed at $DATE ----" >> adslswitch.log
      echo "*** SLEEPING FOR $WAITTIME ***" >> adslswitch.log
    else
      echo " * ADSL connection failing. Attempting backup dialup service." >> adslswitch.log
      echo " * Killing dud ADSL connection (if exists)..." >> adslswitch.log
      $ADSLSTOP 2>> /dev/null
      $KILLALL pppd 2>> /dev/null
      $KILLALL pppoe 2>> /dev/null
      $KILLALL -9 pppd 2>> /dev/null
      $KILLALL -9 pppoe 2>> /dev/null
      $IFDOWN ppp0 2>> /dev/null 
      echo " * Reconnecting to backup dialup service..." >> adslswitch.log
      $PPPD call pi 2>> adslswitch.log
      # Setting waittime to 30 mins for dialup test 
      WAITTIME="30m"
      echo "---- ADSL test completed at $DATE ----" >> adslswitch.log
      echo "*** SLEEPING FOR $WAITTIME ***" >> adslswitch.log
    fi
  fi
  $SLEEP $WAITTIME
done