#!/bin/sh
# updown script setting inbound marks on ESP traffic in the mangle chain
#
# Copyright (C) 2003-2004 Nigel Meteringham
# Copyright (C) 2003-2004 Tuomo Soini
# Copyright (C) 2002-2004 Michael Richardson
# Copyright (C) 2005-2010 Andreas Steffen <andreas.steffen@strongswan.org>
#
# 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 2 of the License, or (at your
# option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
#
# 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.

# CAUTION:  Installing a new version of strongSwan will install a new
# copy of this script, wiping out any custom changes you make.  If
# you need changes, make a copy of this under another name, and customize
# that, and use the (left/right)updown parameters in ipsec.conf to make
# strongSwan use yours instead of this default one.

#      PLUTO_VERSION
#              indicates  what  version of this interface is being
#              used.  This document describes version  1.1.   This
#              is upwardly compatible with version 1.0.
#
#       PLUTO_VERB
#              specifies the name of the operation to be performed
#              (prepare-host, prepare-client, up-host, up-client,
#              down-host, or down-client).  If the address family
#              for security gateway to security gateway communica-
#              tions is IPv6, then a suffix of -v6 is added to the
#              verb.
#
#       PLUTO_CONNECTION
#              is the name of the  connection  for  which  we  are
#              routing.
#
#       PLUTO_INTERFACE
#              is the name of the ipsec interface to be used.
#
#       PLUTO_REQID
#              is the reqid of the AH|ESP policy
#
#       PLUTO_PROTO
#              is the negotiated IPsec protocol, ah|esp
#
#       PLUTO_IPCOMP
#              is not empty if IPComp was negotiated
#
#       PLUTO_UNIQUEID
#              is the unique identifier of the associated IKE_SA
#
#       PLUTO_ME
#              is the IP address of our host.
#
#       PLUTO_MY_ID
#              is the ID of our host.
#
#       PLUTO_MY_CLIENT
#              is the IP address / count of our client subnet.  If
#              the  client  is  just  the  host,  this will be the
#              host's own IP address / max (where max  is  32  for
#              IPv4 and 128 for IPv6).
#
#       PLUTO_MY_SOURCEIP
#       PLUTO_MY_SOURCEIP4_$i
#       PLUTO_MY_SOURCEIP6_$i
#              contains IPv4/IPv6 virtual IP received from a responder,
#              $i enumerates from 1 to the number of IP per address family.
#              PLUTO_MY_SOURCEIP is a legacy variable and equal to the first
#              virtual IP, IPv4 or IPv6.
#
#       PLUTO_MY_PROTOCOL
#              is the IP protocol that will be transported.
#
#       PLUTO_MY_PORT
#              is  the  UDP/TCP  port  to  which  the IPsec SA  is
#              restricted on our side.  For ICMP/ICMPv6 this contains the
#              message type, and PLUTO_PEER_PORT the message code.
#
#       PLUTO_PEER
#              is the IP address of our peer.
#
#       PLUTO_PEER_ID
#              is the ID of our peer.
#
#       PLUTO_PEER_CLIENT
#              is the IP address / count of the peer's client sub-
#              net.   If the client is just the peer, this will be
#              the peer's own IP address / max (where  max  is  32
#              for IPv4 and 128 for IPv6).
#
#       PLUTO_PEER_SOURCEIP
#       PLUTO_PEER_SOURCEIP4_$i
#       PLUTO_PEER_SOURCEIP6_$i
#              contains IPv4/IPv6 virtual IP sent to an initiator,
#              $i enumerates from 1 to the number of IP per address family.
#              PLUTO_PEER_SOURCEIP is a legacy variable and equal to the first
#              virtual IP, IPv4 or IPv6.
#
#       PLUTO_PEER_PROTOCOL
#              is the IP protocol that will be transported.
#
#       PLUTO_PEER_PORT
#              is  the  UDP/TCP  port  to  which  the IPsec SA  is
#              restricted on the peer side.  For ICMP/ICMPv6 this contains the
#              message code, and PLUTO_MY_PORT the message type.
#
#       PLUTO_XAUTH_ID
#              is an optional user ID employed by the XAUTH protocol
#
#       PLUTO_MARK_IN
#              is an optional XFRM mark set on the inbound IPsec SA
#
#       PLUTO_MARK_OUT
#              is an optional XFRM mark set on the outbound IPsec SA
#
#       PLUTO_IF_ID_IN
#              is an optional XFRM interface ID set on the inbound IPsec SA
#
#       PLUTO_IF_ID_OUT
#              is an optional XFRM interface ID set on the outbound IPsec SA
#
#       PLUTO_UDP_ENC
#              contains the remote UDP port in the case of ESP_IN_UDP
#              encapsulation
#
#       PLUTO_DNS4_$i
#       PLUTO_DNS6_$i
#              contains IPv4/IPv6 DNS server attribute received from a
#              responder, $i enumerates from 1 to the number of servers per
#              address family.
#

# define a minimum PATH environment in case it is not set
PATH="/sbin:/bin:/usr/sbin:/usr/bin:/usr/sbin:/usr/local/sbin"
export PATH

# check parameter(s)
case "$1:$*" in
':')			# no parameters
	;;
iptables:iptables)	# due to (left/right)firewall; for default script only
	;;
custom:*)		# custom parameters (see above CAUTION comment)
	;;
*)	echo "$0: unknown parameters \`$*'" >&2
	exit 2
	;;
esac

# define NETMAP
SAME_NET=$PLUTO_PEER_CLIENT
IN_NET=$PLUTO_MY_CLIENT
OUT_NET="10.8.0.0/14"

# define internal interface
INT_INTERFACE="eth1"

# is there an outbound mark to be set?
if [ -n "$PLUTO_MARK_OUT" ]
then
	SET_MARK_OUT="-i $INT_INTERFACE -s $SAME_NET -d $OUT_NET -j MARK --set-mark $PLUTO_MARK_OUT"
fi

# resolve octal escape sequences
PLUTO_MY_ID=`printf "$PLUTO_MY_ID"`
PLUTO_PEER_ID=`printf "$PLUTO_PEER_ID"`

case "$PLUTO_VERB:$1" in
up-client:)
	# connection to my client subnet coming up
	# If you are doing a custom version, firewall commands go here.
	if [ -n "$PLUTO_MARK_IN" ]
	then
	    iptables -t nat -A PREROUTING -i $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_IN \
		     -d $IN_NET -j NETMAP --to $SAME_NET
	    iptables -I FORWARD 1 -i $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_IN -j ACCEPT
	    iptables -t nat -A POSTROUTING -o $INT_INTERFACE -m mark --mark $PLUTO_MARK_IN \
	             -s $SAME_NET -j NETMAP --to $OUT_NET
	fi
	if [ -n "$PLUTO_MARK_OUT" ]
	then
	    iptables -t mangle -A PREROUTING $SET_MARK_OUT
	    iptables -t nat -A PREROUTING -i $INT_INTERFACE -m mark --mark $PLUTO_MARK_OUT \
	             -d $OUT_NET -j NETMAP --to $SAME_NET
	    iptables -I FORWARD 1 -o $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_OUT -j ACCEPT
	    iptables -t nat -A POSTROUTING -o $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_OUT \
	             -s $SAME_NET -j NETMAP --to $IN_NET
	fi
	;;
down-client:)
	# connection to my client subnet going down
	# If you are doing a custom version, firewall commands go here.
	if [ -n "$PLUTO_MARK_IN" ]
	then
	    iptables -t nat -D PREROUTING -i $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_IN \
	             -d $IN_NET -j NETMAP --to $SAME_NET
	    iptables -D FORWARD -i $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_IN -j ACCEPT
	    iptables -t nat -D POSTROUTING -o eth1 -m mark --mark $PLUTO_MARK_IN \
	             -s $SAME_NET -j NETMAP --to $OUT_NET
	fi
	if [ -n "$PLUTO_MARK_OUT" ]
	then
	    iptables -t mangle -D PREROUTING $SET_MARK_OUT
	    iptables -t nat -D PREROUTING -i $INT_INTERFACE -m mark --mark $PLUTO_MARK_OUT \
	             -d $OUT_NET -j NETMAP --to $SAME_NET
	    iptables -D FORWARD -o $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_OUT -j ACCEPT
	    iptables -t nat -D POSTROUTING -o $PLUTO_INTERFACE -m mark --mark $PLUTO_MARK_OUT \
	             -s $SAME_NET -j NETMAP --to $IN_NET
	fi
	;;
*)	echo "$0: unknown verb \`$PLUTO_VERB' or parameter \`$1'" >&2
	exit 1
	;;
esac
