#
# $Id: pf.conf.39.dmz,v 1.4 2006/05/05 09:13:26 raptor Exp $
#
# pf.conf.39.dmz - Sample PF/NAT ruleset for OpenBSD 3.9
# Copyright (c) 2006 Marco Ivaldi <raptor@0xdeadbeef.info>
#
# The pf(4) packet filter modifies, drops or passes packets according to
# rules or definitions specified in pf.conf(5). This is a sample ruleset
# for the configuration of a basic OpenBSD 3.9 stateful packet filter.
#
# This ruleset is meant to work on a stateful firewall with a bridged DMZ 
# network configured on the third NIC. To create and activate a bridge
# between the external and the dmz interface, use the following commands:
#
# $ ifconfig dc0 up
# $ ifconfig dc2 up
# $ ifconfig bridge0 create
# $ brconfig add dc0 add dc2 up
#
# For further information, see bridge(4), brconfig(8), and bridgename.if(5).
#
# Tested on OpenBSD 3.9 with 3 NICs, change it to fit your configuration.
#

###############################################################################
# Macros
#
# User-defined variables may be defined and used later, simplifying the
# configuration file. Macros must be defined before they are referenced.
#

# available interfaces
ext_if=		"dc0"
int_if=		"dc1"
dmz_if=		"dc2"

# list of networks
ext_net=	"x.x.x.0/24"
int_net=	"192.168.0.0/24"

# list of hosts
fw_ext=		"x.x.x.x"
mail_dmz=	"x.x.x.2"
web_dmz=	"x.x.x.3"

###############################################################################
# Tables
#
# Tables provide a mechanism for increasing the performance and flexibility
# of rules with large numbers of source or destination addresses.
#

table 		<private> const { 127/8, 10/8, 172.16/12, 192.168/16 }
table 		<authpf_users> persist

###############################################################################
# Options
#
# Options tune the behaviour of the packet filtering engine.
#

set 		optimization normal
set 		block-policy drop
set		skip on lo0

###############################################################################
# Traffic Normalization
#
# Traffic normalization protects internal machines against inconsistencies
# in Internet protocols and implementations.
#

scrub 		in
#scrub 		out

###############################################################################
# Translation
#
# Translation rules specify how addresses are to be mapped or redirected to
# other addresses.
#

# ftp-proxy anchors
nat-anchor 	"ftp-proxy/*"
rdr-anchor 	"ftp-proxy/*"

# ip masquerading
nat 		on $ext_if inet from $int_net -> $fw_ext

# ftp-proxy
rdr pass	on $int_if inet proto tcp to port 21 -> 127.0.0.1 port 8021

# reverse ftp-proxy (/usr/sbin/ftp-proxy -R x.x.x.3 -p 8022)
#rdr pass	on $ext_if inet proto tcp to port 21 -> 127.0.0.1 port 8022

###############################################################################
# Packet Filtering
#
# Stateful and stateless packet filtering provides rule-based blocking or
# passing of packets.
#

# ftp-proxy anchor
anchor		"ftp-proxy/*"

# default policy
block 		in log
block 		out

# trusted interfaces
pass 		in quick on $int_if inet
pass 		out quick on $int_if inet

# dmz interface
pass		in quick on $dmz_if inet
#pass		out quick on $dmz_if route-to lo0 inet proto tcp to port 8022
pass		out quick on $dmz_if inet

# egress filtering
block		out quick on $ext_if inet from !$ext_net

# anti-spoofing
block 		drop in quick on $ext_if inet from <private>

# outbound traffic (fw + int_net)
pass		out on $ext_if inet proto { icmp, udp, tcp } from $fw_ext \
		keep state
# outbound traffic (dmz)
pass		out on $ext_if inet proto { udp, tcp } from !$fw_ext \
		to port 53 keep state

# inbound traffic (fw)
pass 		in on $ext_if inet proto tcp to $fw_ext \
		port 2222 flags S/SA keep state
# inbound traffic (mail)
pass		in on $ext_if inet proto tcp to $mail_dmz \
		port { 25, 53, 110 } flags S/SA keep state
pass		in on $ext_if inet proto udp to $mail_dmz port 53 keep state
# inbound traffic (web)
pass		in on $ext_if inet proto tcp to $web_dmz \
		port { 21, 53, 80, 443 } flags S/SA keep state
pass		in on $ext_if inet proto udp to $web_dmz port 53 keep state
# remote administration (authpf)
pass		in on $ext_if inet proto tcp from <authpf_users> \
		to { $mail_dmz, $web_dmz } port 22 flags S/SA keep state