The Bash Script To Configure The Firewall Using IPTABLES

#!/bin/bash

##############################
#########Lin u X u niL########
##############################

echo -e "***********Welcome*************"
#IPTABLE SERVICES PROGRAM BEGINS HERE#
checkstatus()
{
 opt_checkstatus=1
while [ $opt_checkstatus != 7 ]
     do
      clear
 #echo -e "\nChoose the Option Bellow!!!\n
 echo -e "\n\t*****Note: Save your Iptables before stop/Restart the iptables Services*****\n"
 echo -e "   1. Save the iptables\n
  2. Status of Iptables\n
  3. Start iptables Services\n
  4. Stop iptables Services\n
  5. Restart iptable Services\n
  6. Flush iptables (**Use Carefully_it will remove all the rules from iptables**)\n
  7. Go back to Main Menu"
 read opt_checkstatus
 case $opt_checkstatus in
  1) echo -e "*******************************************************\n"
              /etc/init.d/iptables save
     echo -e "\n*******************************************************\n"
   echo -e "Press Enter key to Continue..."
   read temp;;
  2) echo -e "*******************************************************\n"
              /etc/init.d/iptables status
     echo -e "*******************************************************"
                               echo -e "Press Enter key to Continue..."
                                    read temp;;
  3) echo -e "*******************************************************\n" 
              /etc/init.d/iptables start
     echo -e "*******************************************************\n"
                                echo -e "Press Enter key to Continue..."
                                      read temp;;
 
  4) echo -e "*******************************************************\n"
              /etc/init.d/iptables stop
     echo -e "*******************************************************\n"
                               echo -e "Press Enter key to Continue..."
                                    read temp;;
   
            5) echo -e "*******************************************************\n"
                     /etc/init.d/iptables restart
     echo -e "*******************************************************\n"
                               echo -e "Press Enter key to Continue..."
                                    read temp;;
  6) iptables -F
  echo -e "*******************************************************"
  echo -e "All the Rules from the Iptables are Flushed!!!"
  echo -e "*******************************************************\n"
                               echo -e "Press Enter key to Continue..."
                                read temp;;
  7) main;;
  *) echo -e "Wrong Option Selected!!!"
 esac
done
}
###############################BUILD FIREWALL PROGRAM BEGINS FROM HERE###############################
buildfirewall()
{
 ###############Getting the Chain############
 echo -e "Using Which Chain of Filter Table?\n
 1. INPUT
 2. OUTPUT
 3. Forward"
 read opt_ch
 case $opt_ch in
  1) chain="INPUT" ;;
  2) chain="OUTPUT" ;;
  3) chain="FORWARD" ;;
  *) echo -e "Wrong Option Selected!!!"
 esac

 #########Getting Source IP Address##########
 #Label
 
 echo -e "
 1. Firewall using Single Source IP\n
 2. Firewall using Source Subnet\n
 3. Firewall using for All Source Networks\n"
 read opt_ip
 
 case $opt_ip in
  1) echo -e "\nPlease Enter the IP Address of the Source"
  read ip_source ;;
  2) echo -e "\nPlease Enter the Source Subnet (e.g 192.168.10.0/24)"
  read ip_source ;;
  3) ip_source="0/0" ;;
  #4) ip_source = "NULL" ;;
  *) echo -e "Wrong Option Selected"
 esac
 #########Getting Destination IP Address##########
  echo -e "
 1. Firewall using Single Destination IP\n
               2. Firewall using Destination Subnet\n
        3. Firewall using for All Destination Networks\n"

    read opt_ip
             case $opt_ip in
       1) echo -e "\nPlease Enter the IP Address of the Destination"
                    read ip_dest ;;
              2) echo -e "\nPlease Enter the Destination Subnet (e.g 192.168.10.0/24)"
                    read ip_dest ;;
              3) ip_dest="0/0" ;;
       #4) ip_dest = "NULL" ;;
              *) echo -e "Wrong Option Selected"
      esac
      ###############Getting the Protocol#############
      echo -e "
      1. Block All Traffic of TCP
      2. Block Specific TCP Service
      3. Block Specific Port
      4. Using no Protocol"
      read proto_ch
      case $proto_ch in
       1) proto=TCP ;;
       2) echo -e "Enter the TCP Service Name: (CAPITAL LETTERS!!!)"
      read proto ;;
       3) echo -e "Enter the Port Name: (CAPITAL LETTERS!!!)"
      read proto ;;
       4) proto="NULL" ;;
       *) echo -e "Wrong option Selected!!!"
      esac

      #############What to do With Rule#############
      echo -e "What to do with Rule?
      1. Accept the Packet
      2. Reject the Packet
      3. Drop the Packet
      4. Create Log"
      read rule_ch
      case $rule_ch in
       1) rule="ACCEPT" ;;
       2) rule="REJECT" ;;
       3) rule="DROP" ;;
       4) rule="LOG" ;;
      esac
###################Generating the Rule####################
echo -e "\n\tPress Enter key to Generate the Complete Rule!!!"
read temp
echo -e "The Generated Rule is \n"
if [ $proto == "NULL" ]; then
echo -e "\niptables -A $chain -s $ip_source -d $ip_dest -j $rule\n"
gen=1
else
echo -e "\niptables -A $chain -s $ip_source -d $ip_dest -p $proto -j $rule\n"
gen=2
fi
echo -e "\n\tDo you want to Enter the Above rule to the IPTABLES? Yes=1 , No=2"
read yesno
if [ $yesno == 1 ] && [ $gen == 1 ]; then
iptables -A $chain -s $ip_source -d $ip_dest -j $rule
else if [ $yesno == 1 ] && [ $gen == 2 ]; then
iptables -A $chain -s $ip_source -d $ip_dest -p $proto -j $rule        
 
else if [ $yesno == 2 ]; then

main
fi
fi
fi
}
    
main()
{
ROOT_UID=0
if [ $UID == $ROOT_UID ];
then
clear
opt_main=1
while [ $opt_main != 4 ]
do
echo -e "/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\n"
#############Check Whether the iptables installed or not############
echo -e "\t*****Main Menu*****\n
1. Check Iptables Package\n
2. Iptables Services\n
3. Build Your Firewall with Iptables\n
4. Exit"
read opt_main
case $opt_main in
 1) echo -e "******************************"
   rpm -q iptables
    echo -e "******************************" ;;
 2) checkstatus ;;
 3) buildfirewall ;;
 4) exit 0 ;;
 *) echo -e "Wrong option Selected!!!"
esac
done
else
echo -e "You Must be the ROOT to Perfom this Task!!!"
fi
}
main
exit 0