#!/bin/bash

echo Flush existing rules
iptables -F
iptables -F -t nat
iptables -F -t mangle
iptables -F -t filter
echo Delete all
iptables -X


if [ "$1" == "-d" ]; then
	echo Input -d open all traffic
	iptables -P INPUT ACCEPT
	iptables -P FORWARD ACCEPT
	exit 0
else 
	echo "Standard Firewall, -d to open all"
fi
ifx=( $(/sbin/ifconfig -s -a | tail -n +2 | cut -f1 -d' ' | grep -v lo) )
for i in ${!ifx[@]}; do
	ipx[$i]="$(/sbin/ifconfig ${ifx[$i]} | grep -m1 -o -P '(?<=inet ).*(?= netmask)')"
	if [ "${ipx[$i]}" == "" ]; then 
		ipx[$i]="----------"
	fi
	printf "%s:\t%s\n" "${ifx[$i]}" "${ipx[$i]}"
done

echo Set Variables
HOST=$(hostname)
SSHPORT=$(cat /etc/ssh/sshd_config | grep Port | grep -v "#" | cut -f2 -d' ')
printf "Local IP: $LOCALIP\nInterface: $NETIF\n"

echo Make Rules


echo Allen verkehr blockieren 
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT 

for i in ${!ifx[@]}; do
	LOCALIP="${ipx[$i]}"
	NETIF="${ifx[$i]}"
	echo "Established Connections for $NETIF"
	iptables -A INPUT -i $NETIF -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
	iptables -A OUTPUT -o $NETIF -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
	echo "DHCP for $NETIF"
	iptables -A OUTPUT -o $NETIF -p udp --dport 67 --sport 68 -m state --state NEW,ESTABLISHED -j ACCEPT
	iptables -A INPUT -i $NETIF -p udp --sport 67 --dport 68 -m state --state RELATED,ESTABLISHED -j ACCEPT
	echo "reject connections from predator IP going over $NETIF"
	iptables -A OUTPUT ! --src $LOCALIP -o $NETIF -j REJECT
	if [ "${HOST}" == "serverhost" ]; then
		echo Incoming https
		iptables -A INPUT -i $NETIF -p tcp --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
		iptables -A OUTPUT -o $NETIF -p tcp --sport 443 -m state --state ESTABLISHED -j ACCEPT
	fi
	echo "Incoming SSH P3032 for $NETIF"
	iptables -A INPUT -i $NETIF -p tcp -m state --state NEW -m tcp --dport $SSHPORT -j ACCEPT
	iptables -A OUTPUT -o $NETIF -p tcp --sport $SSHPORT -m state --state ESTABLISHED -j ACCEPT
	echo "Ping Reply for $NETIF"
	iptables -A INPUT -i $NETIF -p icmp --icmp-type echo-request -j ACCEPT
	iptables -A OUTPUT -o $NETIF -p icmp --icmp-type echo-reply -j ACCEPT
done
echo loopback
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT

echo Logging
iptables -N LOGGING
iptables -A INPUT -j LOGGING
iptables -A LOGGING -m limit --limit 2/min -j LOG --log-prefix "IPTables Packet Dropped: " --log-level 7
iptables -A LOGGING -j DROP

#echo Outgoing https
#iptables -A OUTPUT -o $NETIF -p tcp --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
#iptables -A INPUT -i $NETIF -p tcp --sport 443 -m state --state ESTABLISHED -j ACCEPT

#echo torrents
#iptables -A OUTPUT -o $NETIF -p udp -m state --state NEW,ESTABLISHED -j ACCEPT
#iptables -A INPUT -i $NETIF -p tcp --sport 6890:6999 -m state --state NEW,ESTABLISHED -j ACCEPT
#iptables -A INPUT -i $NETIF -p udp --sport 6890:6999 -m state --state NEW,ESTABLISHED -j ACCEPT

#echo Outgoing SSH p1160
#iptables -A INPUT -i $NETIF -p tcp --sport 1160 -m state --state ESTABLISHED -j ACCEPT
#iptables -A OUTPUT -o $NETIF -p tcp --dport 1160 -m state --state NEW,ESTABLISHED -j ACCEPT

#echo Ping Request
#iptables -A OUTPUT -o $NETIF -p icmp --icmp-type echo-request -j ACCEPT
#iptables -A INPUT -i $NETIF -p icmp --icmp-type echo-reply -j ACCEPT

#echo Incoming SSH p22
#iptables -A INPUT -i $NETIF -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT
#iptables -A OUTPUT -o $NETIF -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT

#echo Outgoing SSH p22
#iptables -A INPUT -i $NETIF -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
#iptables -A OUTPUT -o $NETIF -p tcp --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT

#echo outgouing http
#iptables -A OUTPUT -o $NETIF -p tcp --dport 80 -m state --state NEW -j ACCEPT
#iptables -A INPUT -i $NETIF -p tcp --sport 80 -m state --state RELATED,ESTABLISHED -j ACCEPT

#echo incoming http
#iptables -A INPUT -i $NETIF -p tcp --dport 80 -m state --state RELATED,ESTABLISHED -j DROP
#iptables -A OUTPUT -o $NETIF -p tcp --sport 80 -m state --state NEW -j DROP

#echo DNS
#iptables -A OUTPUT -o $NETIF -p tcp --dport 53 -m state --state NEW -j ACCEPT
#iptables -A OUTPUT -o $NETIF -p udp --dport 53 -m state --state NEW -j ACCEPT
#iptables -A INPUT -i $NETIF -p tcp --sport 53 -m state --state NEW -j ACCEPT
#iptables -A INPUT -i $NETIF -p udp --sport 53 -m state --state NEW -j ACCEPT