openrc/init.d/ipfw.in

#!@PREFIX@/sbin/runscript
# Copyright 2007-2009 Roy Marples <roy@marples.name>
# All rights reserved. Released under the 2-clause BSD license.

# This is based on /etc/rc.firewall and /etc/rc.firewall6 from FreeBSD

ipfw_ip_in=${ipfw_ip_in-any}
ipfw_ports_in=${ipfw_ports_in-auth ssh}
ipfw_ports_nolog=${ipfw_ports_nolog-135-139,445 1026,1027 1433,1434}

opts="panic showstatus"

depend() {
	before net
	provide firewall
	keyword nojail
}

ipfw() {
	/sbin/ipfw -f -q "$@"
}

have_ip6() {
	sysctl net.ipv6 2>/dev/null
}

init() {
	# Load the kernel module
	if ! sysctl net.inet.ip.fw.enable=1 >/dev/null 2>&1; then
		if ! kldload ipfw; then
			eend 1 "Unable to load firewall module"
			return 1
		fi
	fi

	# Now all rules and give a good base
	ipfw flush

	ipfw add pass all from any to any via lo0
	ipfw add deny all from any to 127.0.0.0/8
	ipfw add deny ip from 127.0.0.0/8 to any

	if have_ip6; then 
		ipfw add pass ip6 from any to any via lo0
		ipfw add deny ip6 from any to ::1
		ipfw add deny ip6 from ::1 to any
	
		ipfw add pass ip6 from :: to ff02::/16 proto ipv6-icmp
		ipfw add pass ip6 from fe80::/10 to fe80::/10 proto ipv6-icmp
		ipfw add pass ip6 from fe80::/10 to ff02::/16 proto ipv6-icmp
	fi
}

start() {
	local i= p= log=
	ebegin "Starting firewall rules"
	if ! init; then
		eend 1 "Failed to flush firewall ruleset"
		return 1
	fi

	# Use a statefull firewall
	ipfw add check-state
	ipfw add pass tcp from me to any established

	# Allow any connection out, adding state for each.
	ipfw add pass tcp  from me  to any setup keep-state
	ipfw add pass udp  from me  to any       keep-state
	ipfw add pass icmp from me  to any       keep-state

	if have_ip6; then
		ipfw add pass tcp  from me6 to any setup keep-state
		ipfw add pass udp  from me6 to any       keep-state
		ipfw add pass icmp from me6 to any       keep-state
	fi

	# Allow DHCP.
	ipfw add pass udp  from 0.0.0.0 68 to 255.255.255.255 67 out
	ipfw add pass udp  from any 67     to me 68 in
	ipfw add pass udp  from any 67     to 255.255.255.255 68 in
	# Some servers will ping the IP while trying to decide if it's 
	# still in use.
	ipfw add pass icmp from any to any icmptype 8

	# Allow "mandatory" ICMP in.
	ipfw add pass icmp from any to any icmptype 3,4,11

	if have_ip6; then
		# Allow ICMPv6 destination unreach
		ipfw add pass ip6 from any to any icmp6types 1 proto ipv6-icmp
	
		# Allow NS/NA/toobig (don't filter it out)
		ipfw add pass ip6 from any to any icmp6types 2,135,136 proto ipv6-icmp
	fi
	
	# Add permits for this workstations published services below
	# Only IPs and nets in firewall_allowservices is allowed in.
	for i in $ipfw_ip_in; do
		for p in $ipfw_ports_in; do
			ipfw add pass tcp from $i to me $p
		done
	done

	# Allow all connections from trusted IPs.
	# Playing with the content of firewall_trusted could seriously
	# degrade the level of protection provided by the firewall.
	for i in $ipfw_ip_trust; do
		ipfw add pass ip from $i to me
	done
	
	ipfw add 65000 count ip from any to any

	# Drop packets to ports where we don't want logging
	for p in $ipfw_ports_nolog; do
		ipfw add deny { tcp or udp } from any to any $p in
	done

	# Broadcasts and muticasts
	ipfw add deny ip from any to 255.255.255.255
	ipfw add deny ip from any to 224.0.0.0/24 

	# Noise from routers
	ipfw add deny udp from any to any 520 in

	# Noise from webbrowsing.
	# The statefull filter is a bit agressive, and will cause some
	# connection teardowns to be logged.
	ipfw add deny tcp from any 80,443 to any 1024-65535 in

	# Deny and (if wanted) log the rest unconditionally.
	if yesno ${ipfw_log_deny:-no}; then
		log=log
		sysctl net.inet.ip.fw.verbose=1 >/dev/null
	fi
	ipfw add deny $log ip from any to any

	eend 0
}

stop() {
	ebegin "Stopping firewall rules"
	# We don't unload the kernel module as that action
	# can cause memory leaks as of FreeBSD 6.x
	sysctl net.inet.ip.fw.enable=0 >/dev/null
	eend $?
}

panic() {
	ebegin "Stopping firewall rules - hard"
	if ! init; then
		eend 1 "Failed to flush firewall ruleset"
		return 1
	fi
	eend 0
}

showstatus() {
	ipfw show
}