init script to automatically start vpnc on TomatoUSB 1.28 Shibby K26RT-N build 101

autostart-vpnc.sh

#!/opt/bin/bash
#
# requires: ipkg install bash procps

SERVICE_NAME=autostart-vpnc.sh
LOGFILE=/opt/var/log/$SERVICE_NAME.log
PACKET_LOGFILE=/var/log/messages

EXTERNAL_IF=vlan2
POLLING_INTERVAL=30

function set_service_pid {
  PID=$(pgrep -o -f $SERVICE_NAME) 
}

function set_vpnc_pid {
  VPNC_PID=$(pgrep -o -f ^vpnc)
}

function traffic_monitor {
  while true; do
    set_vpnc_pid

    if [ -z "$VPNC_PID" ]; then
      logger "$SERVICE_NAME [$$] starting vpnc"
      date >> $LOGFILE
      vpnc >> $LOGFILE

      TUNNEL_DEVICE=$(ifconfig | grep tun | awk '{print $1}')
      TUNNEL_NAT=$(iptables --table nat --list POSTROUTING --verbose | grep $TUNNEL_DEVICE)

      if [ -z "$TUNNEL_NAT" ]; then
        # routing table will be configured by vpnc, add masquerade rule only
        iptables --table nat --append POSTROUTING --out-interface $TUNNEL_DEVICE --jump MASQUERADE
      fi
    else
      while [ -n "$VPNC_PID" ]; do
        # wait for disconnect
        sleep $POLLING_INTERVAL
        set_vpnc_pid
      done

      logger "$SERVICE_NAME [$$] vpnc has stopped"
    fi
  done
}

function start {
  set_service_pid

  if [ "$PID" == "$$" ]; then
    if [ ! -d ${LOGFILE%/*} ]; then
      mkdir -p ${LOGFILE%/*}
    fi
    traffic_monitor &
  else
    echo "$SERVICE_NAME already running at $PID"
  fi
}

function stop {
  set_service_pid

  while [ "$PID" != "$$" ]; do
    kill $PID
    set_service_pid
  done

  set_vpnc_pid

  if [ -n "$VPNC_PID" ]; then
    vpnc-disconnect
  fi
}

function status {
  set_service_pid

  if [ "$PID" != "$$" ]; then
    set_service_pid
    echo "$SERVICE_NAME is running at pid $PID"
  else
    echo "$SERVICE_NAME is not running"
  fi

  set_vpnc_pid

  if [ -n "$VPNC_PID" ]; then
    echo "vpnc is running at pid $VPNC_PID"
  else
    echo "vpnc is not running"
  fi
}

case $1 in
  start)   start ;;
  stop)    stop  ;;
  restart) $0 stop; $0 start ;;
  status)  status ;;
  *)       echo "Usage: $0 {start|stop|status}"
esac