Socat Manager

socat-manager.sh

#!/bin/bash
# SOCAT Port Forwarder Management Script
# Created By Dimas Restu Hidayanto (dimas.restu@student.upi.edu)

IS_NUMBER='^[0-9]+$'

if [ $UID != 0 ]; then
  echo "Administrator Previlege Needed. Please Run This Program As An Administrator/Root User!"
  exit 1
fi

SOCAT_EXIST=$(which socat | wc -l)
if [ $SOCAT_EXIST -eq 0 ]; then
  echo "Please Install Socat (socat) Command First!"
  exit 1
fi

if [ -z $1 ]; then
  echo "Operation Not Found"
  echo "Available Operations:"
  echo "- add <external_port> <destination_ip> <destination_port>"
  echo "- remove <external_port> <destination_ip> <destination_port>"
  echo "- reload"
  exit 0
fi

case $1 in
  "add")
    if [ -z $2 ]; then
      echo "Please Specifiy External Port"
      exit 1
    else
      if ! [[ $2 =~ $IS_NUMBER ]]; then
        echo "External Port Must Be in Number Format!"
        exit 1
      fi

      if [[ -f /etc/socat-iface.list ]]; then
        SOCAT_EXTERNAL_PORT_EXIST_IN_LIST=$(cat /etc/socat-iface.list | awk -F' ' '{print $1}' | grep "$2" | wc -l)
        if [[ $SOCAT_EXTERNAL_PORT_EXIST_IN_LIST -gt 0 ]]; then
          echo "External Port Already Exsist in Socat Interface, Please Use Another Port!"
          exit 1
        fi
      fi
    fi

    if [ -z $3 ]; then
      echo "Please Specifiy Destination IP"
      exit 1
    fi

    if [ -z $4 ]; then
      echo "Please Specifiy Destination Port"
      exit 1
    else
      if ! [[ $4 =~ $IS_NUMBER ]]; then
        echo "Destination Port Must Be in Number Format!"
        exit 1
      fi
    fi

    echo "Exposing Port to External Port"
    socat TCP-LISTEN:$2,fork TCP:$3:$4 >> /dev/null 2>&1 &

    echo "Adding to Socat Interface List"
    echo "$2 $3 $4" >> /etc/socat-iface.list

    ;;
  "remove")
    if [ -z $2 ]; then
      echo "Please Specifiy External Port"
      exit 1
    else
      if ! [[ $2 =~ $IS_NUMBER ]]; then
        echo "External Port Must Be in Number Format!"
        exit 1
      fi
    fi

    if [ -z $3 ]; then
      echo "Please Specifiy Destination IP"
      exit 1
    fi

    if [ -z $4 ]; then
      echo "Please Specifiy Destination Port"
      exit 1
    else
      if ! [[ $4 =~ $IS_NUMBER ]]; then
        echo "Destination Port Must Be in Number Format!"
        exit 1
      fi
    fi

    if [[ -f /etc/socat-iface.list ]]; then
      SOCAT_IFACE_EXIST_IN_LIST=$(cat /etc/socat-iface.list | grep "$2 $3 $4" | wc -l)
      if [[ $SOCAT_IFACE_EXIST_IN_LIST -eq 0 ]]; then
        echo "Socat Interface Doesn't Exist, Please Re-Check Your Input First!"
        exit 1
      fi

      echo "Stoping Spesified Socat Process"
      SOCAT_PID=$(ps -ef | grep "socat TCP-LISTEN:$2,fork TCP:$3:$4" | head -n 1 | awk -F' ' '{print $2}')
      kill -9 $SOCAT_PID

      echo "Removing From Socat Interface List"
      sed -i -e "/$2 $3 $4/d" /etc/socat-iface.list
    fi

    ;;
  "reload")
    echo "Stoping All Exsisting Socat Process"
    killall socat
    sleep 1

    if [[ -f /etc/socat-iface.list ]]; then
      IFS=$'\n'

      echo "Re-Exposing All Port to External Port"
      for SOCAT_IFACE in $(cat /etc/socat-iface.list)
      do
        SOCAT_EXTERNAL_PORT=$(echo "$SOCAT_IFACE" | awk -F' ' '{print $1}')
        SOCAT_DESTINATION_IP=$(echo "$SOCAT_IFACE" | awk -F' ' '{print $2}')
        SOCAT_DESTINATION_PORT=$(echo "$SOCAT_IFACE" | awk -F' ' '{print $3}')

        socat TCP-LISTEN:$SOCAT_EXTERNAL_PORT,fork TCP:$SOCAT_DESTINATION_IP:$SOCAT_DESTINATION_PORT >> /dev/null 2>&1 &
      done
    fi

    ;;
  *)
    echo "Operation Not Valid"
    echo "Available Operations:"
    echo "- add <external_port> <destination_ip> <destination_port>"
    echo "- remove <external_port> <destination_ip> <destination_port>"
    echo "- reload"
    exit 0

    ;;
esac

exit 0