#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2012  IPFire Network Development Team                         #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

function policy_add_zone() {
	local zone=${1}
	assert isset zone

	log DEBUG "Creating firewall policy for zone '${zone}'."

	local chain="ZONE_${zone}"
	chain=${chain^^}

	# Create filter chain.
	iptables_chain_create ${chain}
	iptables -A INPUT   -i ${zone} -j ${chain}
	iptables -A FORWARD -i ${zone} -j ${chain}
	iptables -A FORWARD -o ${zone} -j ${chain}
	iptables -A OUTPUT  -o ${zone} -j ${chain}

	# Leave some space for own rules right at the beginning
	# to make it possible to overwrite _everything_.
	iptables_chain_create ${chain}_CUSTOM
	iptables -A ${chain} -j ${chain}_CUSTOM

	# Intrusion Prevention System
	iptables_chain_create ${chain}_IPS
	iptables -A ${chain} -i ${zone} -j ${chain}_IPS

	# Port forwarding chain.
	iptables_chain_create ${chain}_PORTFW
	iptables -A ${chain} -i ${zone} -j ${chain}_PORTFW

	# Outgoing firewall
	iptables_chain_create ${chain}_OUTFW
	iptables -A ${chain} -o ${zone} -j ${chain}_OUTFW

	# Policy rules
	iptables_chain_create ${chain}_POLICY
	iptables -A ${chain} -j ${chain}_POLICY

	# Create mangle chain.
	iptables_chain_create -t mangle ${chain}
	iptables -t mangle -A PREROUTING  -i ${zone} -j ${chain}
	iptables -t mangle -A POSTROUTING -o ${zone} -j ${chain}

	# Quality of Service
	iptables_chain_create -t mangle ${chain}_QOS_INC
	iptables -t mangle -A ${chain} -i ${zone} -j ${chain}_QOS_INC
	iptables_chain_create -t mangle ${chain}_QOS_OUT
	iptables -t mangle -A ${chain} -o ${zone} -j ${chain}_QOS_OUT

	# Create NAT chain.
	iptables_chain_create -t nat ${chain}
	iptables -t nat -A PREROUTING  -i ${zone} -j ${chain}
	iptables -t nat -A POSTROUTING -o ${zone} -j ${chain}

	# Network Address Translation
	iptables_chain_create -t nat ${chain}_NAT
	iptables -t nat -A ${chain} -i ${zone} -j ${chain}_NAT

	# Portforwarding
	iptables_chain_create -t nat ${chain}_PORTFW
	iptables -t nat -A ${chain} -i ${zone} -j ${chain}_PORTFW

	# UPNP
	iptables_chain_create -t nat ${chain}_UPNP
	iptables -t nat -A ${chain} -j ${chain}_UPNP

	# After the chains that are always available have been
	# created, we will add a custom policy to every single
	# zone.

	# Local zones are currently allowed to access everything.
	if zone_is_local ${zone}; then
		policy_allow_all ${zone} ${chain}

	# Uplink connections are not.
	else
		: # XXX TODO
	fi
}

function policy_add_localhost() {
	log DEBUG "Creating firewall policy for localhost..."

	# Accept everything on lo
	iptables -A INPUT  -i lo -j ACCEPT
	iptables -A OUTPUT -o lo -j ACCEPT
}

function policy_allow_all() {
	local zone=${1}
	assert isset zone

	local chain=${2}
	assert isset chain

	# Just accept everything.
	iptables -A ${chain}_POLICY -j ACCEPT
}