#!/usr/bin/bash

#***************************************************************************
# Copyright Ralf Senderek, Ireland 2014-2015. (http://senderek.ie)
#
# This file is part of the CRYPTO BONE
# File     : firewall
# Version  : 1.5 (external cryptobone)
# License  : BSD
# Date     : Wednesday, 1 March 2023
# Contact  : Please send enquiries and bug-reports to innovation@senderek.ie
#
# Copyright (c) 2015-2023
#	Ralf Senderek, Ireland.  All rights reserved. (https://senderek.ie)
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#	   This product includes software developed by Ralf Senderek.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND  ANY EXPRESS OR 
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE  IMPLIED WARRANTIES 
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
# POSSIBILITY OF SUCH DAMAGE.
##############################################################################



# My LAN
IFACE=$(echo $(arp -n| sed -n '2p') | cut -f5 -d" ")
ME="1.2.3.4"
if /sbin/ifconfig $IFACE > /dev/null
then
     ME=$(echo $(/sbin/ifconfig $IFACE | /usr/bin/grep "inet ") | /usr/bin/cut -f2 -d" ")
fi


###############################################################################

echo
echo "FIREWALL-Script for EXTERNAL CRYPTO BONE   version 1.5 - March 2023 at $ME"
echo "Interface: $IFACE"
echo

## DISABLE IP Forwarding ##
/bin/echo 0 > /proc/sys/net/ipv4/ip_forward
		 
if test  $# -eq 1
then
    case $1 in 
        red)     echo -n -e "\033[40;31;1mRED\033[0m"
	         echo "     Restrict the IP transport rigorously"
		 
                 # DEFAULT-POLICIES
                 /sbin/iptables -P FORWARD DROP
                 /sbin/iptables -P INPUT DROP
                 /sbin/iptables -P OUTPUT DROP
		 
		 # Clear all rules
		 /sbin/iptables -F FORWARD
		 /sbin/iptables -F INPUT
		 /sbin/iptables -F OUTPUT
                 
		 # allow all established and related connections
                 /sbin/iptables -A INPUT   -m state --state ESTABLISHED,RELATED   -j ACCEPT
                 /sbin/iptables -A OUTPUT  -m state --state ESTABLISHED,RELATED   -j ACCEPT


		 #
                 # RULES FOR THE LAN 
		 #


                 # allow ping 
		 /sbin/iptables -A INPUT   -p ICMP -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p ICMP -j ACCEPT
                 
		 # allow ssh (in-bound to port 22)
		 /sbin/iptables -A INPUT  -p tcp  --dport 22  -j ACCEPT
		 /sbin/iptables -A OUTPUT -p tcp  --sport 22  -j ACCEPT
		 # allow ssh (out-bound to port 22)
		 /sbin/iptables -A INPUT  -p tcp  --sport 22  -j ACCEPT
		 /sbin/iptables -A OUTPUT -p tcp  --dport 22  -j ACCEPT
                 
		 # allow DNS 
		 /sbin/iptables -A INPUT  -p udp   --sport 53  -j ACCEPT
		 /sbin/iptables -A OUTPUT -p udp   --dport 53  -j ACCEPT
                 
                 # allow  BOOTP
		 /sbin/iptables -A INPUT   -p udp  --dport 67  -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p udp  --sport 67  -j ACCEPT
		 /sbin/iptables -A INPUT   -p udp  --dport 68  -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p udp  --sport 68  -j ACCEPT
                 
		 # allow outgoing SMTP 
		 /sbin/iptables -A INPUT  -p tcp  --sport 25  -j ACCEPT
		 /sbin/iptables -A OUTPUT -p tcp  --dport 25  -j ACCEPT
		 /sbin/iptables -A INPUT  -p tcp  --sport 587  -j ACCEPT
		 /sbin/iptables -A OUTPUT -p tcp  --dport 587  -j ACCEPT
		 
		 # allow  POP3
		 /sbin/iptables -A INPUT   -p tcp  --sport 110  -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p tcp  --dport 110  -j ACCEPT
		 /sbin/iptables -A INPUT   -p tcp  --sport 995  -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p tcp  --dport 995  -j ACCEPT
                 
		 # allow  IMAP
		 /sbin/iptables -A INPUT   -p tcp  --sport 143  -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p tcp  --dport 143  -j ACCEPT
		 /sbin/iptables -A INPUT   -p tcp  --sport 993  -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p tcp  --dport 993  -j ACCEPT
                 
                 
		 # allow  NTP
		 /sbin/iptables -A INPUT   -p tcp  --dport 123 -j ACCEPT
		 /sbin/iptables -A OUTPUT  -p tcp  --sport 123 -j ACCEPT
                 
		 ;;

	green)   echo -e "\033[40;32;1mGREEN\033[0m" 
	         echo "Allow everything, shut down firewall protection completely."

                 # DEFAULT-POLICIES
                 /sbin/iptables -P FORWARD ACCEPT
                 /sbin/iptables -P INPUT ACCEPT 
                 /sbin/iptables -P OUTPUT ACCEPT
		 
		 # Clear all rules
		 /sbin/iptables -F FORWARD
		 /sbin/iptables -F INPUT
		 /sbin/iptables -F OUTPUT
                 
		 /sbin/iptables -A INPUT  -p all  -j LOG
		 /sbin/iptables -A OUTPUT -p all  -j LOG
                 
	         ;;
	"status") echo -e "\033[40;34;1mSTATUS:\033[0m"
	          echo
	          /sbin/iptables -L -v
	          ;;

        *)        echo "unknown option: $1"		 
                  echo "\nusage : firewall [red | green | status]"
    esac	

else
    echo "usage : firewall [red | green | status]"

fi


###############################################################