#!/usr/bin/env bash

declare -i val=`cat /proc/sys/net/ipv4/ip_forward`

LOCK_DIR="$(mktemp -d)"

#---------------------------------------
#-----------------------------
# Base Function(s)
#-----------------------------
#---------------------------------------

fatal(){
   echo ""
   if $terminal ; then
      echo -e "   [ \033[31m\033[1mFatal\033[m ] $*"
   else
      echo -e "   [ Fatal ] $*"
   fi
   echo ""
   if $terminal ; then
      echo -e "             \033[1mScript terminated\033[m.."
   else
      echo -e "             Script terminated.."
   fi
   echo ""
   rm -rf $LOCK_DIR
   exit 1
}

error (){
   echo ""
   if $terminal ; then
      echo -e "   [ \033[31m\033[1mError\033[m ] $*"
   else
      echo "   [ Error ] $*"
   fi
   echo ""
}

warn (){
   echo ""
   if $terminal ; then
      echo -e "   [ \033[33m\033[1mWarn\033[m ]  $*"
   else
      echo "   [ Warn ]  $*"
   fi
   echo ""
}

info (){
   echo ""
   if $terminal ; then
      echo -e "   [ \033[32m\033[1mInfo\033[m ]  $*"
   else
      echo "   [ Info ]  $*"
   fi
   echo ""
}

ok (){
   echo ""
   if $terminal ; then
      echo -e "   [ \033[32m\033[1mOk\033[m ]    $*"
   else
      echo "   [ Ok ]    $*"
   fi
   echo ""
}

trim() {
    local var="$*"
    var="${var#"${var%%[![:space:]]*}"}"   # remove leading whitespace characters
    var="${var%"${var##*[![:space:]]}"}"   # remove trailing whitespace characters
    echo -n "$var"
}

#-----------------------------
# Check some prerequisites
#-----------------------------
#---------------------------------------

# - Running in a terminal?
# -
if [[ -t 1 ]] ; then
   terminal=true
   LOGGING=true
else
   terminal=false
   LOGGING=false
fi


if $LOGGING ; then
   echo -e "\n   Check if Forwarding ist activated.."
   echo -e "   ==================================="
fi

if [[ $(cat /proc/sys/net/ipv4/ip_forward) -eq 1 ]]; then
   if $LOGGING ; then
      ok "Forwarding is activated."
   fi
else
   error "Forwarding seems NOT to be activated. Try to activate forwarding nos.."

   echo 1 > /proc/sys/net/ipv4/ip_forward


   if [[ $(cat /proc/sys/net/ipv4/ip_forward) -eq 1 ]]; then
      ok "Forwarding is now activated."
   else
      error "Activating Forwarding failed!"
      exit 1
   fi
fi

VAL=$(cat /proc/sys/net/ipv4/ip_dynaddr)
if [[ "$VAL" -eq 0 ]]; then
   error  "ip_dynaddr: DEAKTIVIERT ($VAL). Try to set value to '3'.."

   echo 3 > /proc/sys/net/ipv4/ip_dynaddr

   VAL=$(cat /proc/sys/net/ipv4/ip_dynaddr)

   if [[ "$VAL" -eq 3 ]]; then

      ok "ip_dynaddr: AKTIV + Verbose Logging ($VAL)"

   else

      error "Seting '/proc/sys/net/ipv4/ip_dynaddr' to '3' failed!"
      exit 1
   fi

elif [[ "$VAL" -eq 1 ]]; then

   if $LOGGING ; then

      ok "ip_dynaddr: AKTIV ($VAL)."

   fi

elif [[ "$VAL" -eq 2 ]]; then

   if $LOGGING ; then

      ok "ip_dynaddr: AKTIV + Verbose Logging ($VAL)"

   fi

elif [[ "$VAL" -eq 3 ]]; then

   if $LOGGING ; then

      ok "ip_dynaddr: AKTIV + Verbose Logging ($VAL)"

   fi

else
   error "ip_dynaddr: UNBEKANNTER WERT ($VAL). Try to set value to '3'.."

   echo 3 > /proc/sys/net/ipv4/ip_dynaddr

   VAL=$(cat /proc/sys/net/ipv4/ip_dynaddr)

   if [[ "$VAL" -eq 3 ]]; then

      ok "ip_dynaddr: AKTIV + Verbose Logging ($VAL)"

   else

      error "Seting '/proc/sys/net/ipv4/ip_dynaddr' to '3' failed!"
      exit 1
   fi

fi


rm -rf $LOCK_DIR
exit 0