#!/bin/sh

PATH=$PATH:/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/sbin:/usr/local/bin
# We need to ping someone to see if it's up
# We could try someone like Google who is likely to be up ...
# HOST_TO_TEST=www.google.com
# Or we could test our PPP peer (which seems like a better idea). If you have more than one PPP
# connection, this will find the first which ifconfig reports.
HOST_TO_TEST=`ifconfig -a|grep "inet addr"|grep "P-t-P" |head -1|cut -d":" -f3-|awk '{ print $1 }'`


# How often do we do the test? If we test more often, we will find
# the failure sooner. If we test too often, we'll be wasting CPU time
# and bandwidth. 120 = 2 minutes
TEST_FREQ=120
TEST_FREQ=20



# NUM_FAIL - how many times can it fail before restarting?
NUM_FAIL=2


################ function definitions ###################

ppp_test()
{
  ping -w 10 -c1 ${HOST_TO_TEST} > /dev/null 2>&1
  return $?
}

ppp_start()
{
  echo "Starting PPPd"
  pppd call adsl
  sleep 30
  HOST_TO_TEST=`ifconfig -a|grep "inet addr"|grep "P-t-P" |cut -d":" -f3-|awk '{ print $1 }'`
}

ppp_kill()
{
  pid=`pidof pppd`
  while [ ! -z $pid ]; do
    pid=`pidof pppd`
    kill -9 $pid
    sleep 2
  done
}

ppp_check()
{
  ppp_test
  if [ "$?" -ne "0" ]; then
    if [ "$1" -ge "$NUM_FAIL" ]; then
      echo "PPP Connection Down... restarting"
      ppp_kill
      sleep 20
      ppp_start 
    else
      echo "PPP Connection down? (Test $1 of $NUM_FAIL)"
      NF=`expr $1 + 1`
      sleep 20
      ppp_check $NF
    fi
  fi
}

########### starts here ##############

if [ "$1" == "stop" ]; then
  echo "Shutting down PPPd"
  ppp_kill
  exit 0
fi

# We assume that the firmware is loaded.
# It needs to be loaded exactly once but there doesn't
# seem to be a way of testing if it has already been loaded.
# So this script assumes that the firmware is loaded, and
# that pppd is probably running.
# Or you can uncomment this line and make sure it points to your firmware:
# /usr/local/sbin/modem_run -m -f /etc/ppp/mgmt.o

while :
do
  ppp_check 1
  sleep $TEST_FREQ
done