#!/bin/bash
#

## Firewall Script
#  01-07-26  by Erik Wegner
#  domain-up <Interface> <Network>
#

INT=$1  # Interface
NET=$2  # Network

if test -z $1 || test -z $2 ; then
	echo "domain-up <Interface> <Network>"
	echo "e.g.: domain-up eth0 192.168.4.0/255.255.255.0"
	exit 2
fi

# Pfad zu IPTables
if test -z $IPTABLES ; then
	IPTABLES=/usr/sbin/iptables
fi

## Ports
#  Nicht-privilegierte = 1024-65535
P_HIGH=1024:65535
P_DOMAIN=53

echo -e "\n#DNS Server $NET [$P_HIGH] <-> $INT [$P_DOMAIN]"

# UDP-Verbindungen
echo "$IPTABLES -A INPUT -i $INT -p UDP \\
	-s $NET --sport $P_HIGH \\
	--dport $P_DOMAIN -j ACCEPT"

echo "$IPTABLES -A OUTPUT -o $INT -p UDP \\
	--sport $P_DOMAIN \\
	--dport $P_HIGH -d $NET -j ACCEPT"

# TCP-Verbindungen
echo -e "\n$IPTABLES -A INPUT -i $INT -p TCP \\
	-s $NET --sport $P_HIGH \\
	--dport $P_DOMAIN -j ACCEPT"

echo "$IPTABLES -A OUTPUT -o $INT -p TCP \\
	--sport $P_DOMAIN \\
	--dport $P_HIGH -d $NET -j ACCEPT"

