#! /bin/sh
# iproute2 version, default updown script
#
# Copyright (C) 2003-2004 Nigel Metheringham
# Copyright (C) 2002-2007 Michael Richardson <mcr@xelerance.com>
# Copyright (C) 2003-2013 Tuomo Soini <tis@foobar.fi>
# Copyright (C) 2008 Paul Wouters <paul@xelerance.com>
#
# 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 Libreswan 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
# Libreswan use yours instead of this default one.

test ${IPSEC_INIT_SCRIPT_DEBUG} && set -v -x

LC_ALL=C
export LC_ALL

# things that this script gets (from ipsec_pluto(8) man page)
#
#
#	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 communications
#		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_CONN_POLICY
#		the policy of the connection, as in:
#		RSASIG+ENCRYPT+TUNNEL+PFS+DONTREKEY+OPPORTUNISTIC
#		+failureDROP+lKOD+rKOD
#
#	PLUTO_NEXT_HOP
#		is the next hop to which packets bound for the peer
#		must be sent.
#
#	PLUTO_INTERFACE
#		is the name of the ipsec interface to be used.
#
#	PLUTO_ME
#		is the IP address of our host.
#
#	PLUTO_METRIC
#		is the metric to set for the route
#
#	PLUTO_MTU
#		is the mtu to set for the route
#
#	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_CLIENT_NET
#		is the IP address of our client net.  If the client
#		is just the host, this will be the  host's  own	 IP
#		address.
#
#	PLUTO_MY_CLIENT_MASK
#		is  the	 mask for our client net.  If the client is
#		just the host, this will be 255.255.255.255.
#
#	PLUTO_MY_SOURCEIP
#		if non-empty, then the source address for the route will be
#		set to this IP address.
#
#	PLUTO_MY_PROTOCOL
#		is the protocol	 for this  connection.	Useful	for
#		firewalling.
#
#	PLUTO_MY_PORT
#		is the port. Useful for firewalling.
#
#	PLUTO_PEER
#		is the IP address of our peer.
#
#	PLUTO_PEER_CLIENT
#		is the IP address / count of the peer's client subnet.
#		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_CLIENT_NET
#		is the IP address of the peer's client net.  If the
#		client is just the peer, this will  be	the  peer's
#		own IP address.
#
#	PLUTO_PEER_CLIENT_MASK
#		is  the	 mask  for  the	 peer's client net.  If the
#		client	 is   just   the   peer,   this	  will	 be
#		255.255.255.255.
#
#	PLUTO_PEER_PROTOCOL
#		is  the	 protocol  set	for  remote  end  with port
#		selector.
#
#	PLUTO_PEER_PORT
#		is the peer's port. Useful for firewalling.
#
#	PLUTO_CONNECTION_TYPE
#
#	PLUTO_CONN_ADDRFAMILY
#		is the family type, "ipv4" or "ipv6"
#
#	PLUTO_STACK
#		IPsec stack used by pluto (eg protostack= values)
#
#	PLUTO_NM_CONFIGURED
#		is NetworkManager used for resolv.conf update
#
#	PLUTO_SAREF_TRACKING
#		If we need to manipulate any iptables for SAref tracking
#
#       PLUTO_SA_REQID
#               When using KAME or XFRM/NETKEY, the IPsec SA reqid value

# for debugging of the script
#exec >/tmp/_updown.m$$
#exec 2>&1
#set -x

# Import default _updown configs from the @FINALSYSCONFDIR@/[sysconfig|default]pluto_updown file
#
# Two variables can be set in this file:
#
#	DEFAULTSOURCE
#		is the default value for PLUTO_MY_SOURCEIP
#
#	IPROUTEARGS
#		is the extra argument list for ip route command
#
#	IPRULEARGS
#		is the extra argument list for ip rule command
#

# rpm based systems
if [ -f @FINALSYSCONFDIR@/sysconfig/pluto_updown ]; then
    . @FINALSYSCONFDIR@/sysconfig/pluto_updown
# deb based systems
elif [ -f @FINALSYSCONFDIR@/default/pluto_updown ]; then
    . @FINALSYSCONFDIR@/default/pluto_updown
fi

LIBRESWAN_RESOLV_CONF=@FINALVARDIR@/run/pluto/libreswan-resolv-conf-backup
ORIG_RESOLV_CONF=@FINALSYSCONFDIR@/resolv.conf

use_comment=true

# check parameter(s)
case "${1}:$*" in
    ':')
	# no parameters
	;;
    custom:*)
	# custom parameters (see above CAUTION comment)
	;;
    *)
	echo "${0}: unknown parameters \"$*\"" >&2
	exit 2
	;;
esac

# function to see if iptables has an IPSEC chain already, and if not,
# it will create one and insert it into the OUTPUT and FORWARD chains.
checkipsec() {
    if [ -z "${PLUTO_SAREF_TRACKING}" -o "${PLUTO_SAREF_TRACKING}" = "no" ]; then
	echo "SAref table initialisation left to third party"
    elif [ -z "${PLUTO_CONN_ADDRFAMILY}" -o "${PLUTO_CONN_ADDRFAMILY}" = "ipv6" ]; then
	echo "SAref not activated for IPv6"
    else
	# make sure we have an IPSEC chain
	if ! ( iptables -n -t mangle -L IPSEC >/dev/null 2>&1); then
	    iptables -t mangle -N IPSEC
	fi
	if ! ( ip6tables -n -t mangle -L IPSEC >/dev/null 2>&1); then
	    ip6tables -t mangle -N IPSEC
	fi

	# we also need to have a NEW_IPSEC_CONN chain
	if ! ( iptables -n -t mangle -L NEW_IPSEC_CONN >/dev/null 2>&1); then
	    iptables -t mangle -N NEW_IPSEC_CONN
	fi
	if ! ( ip6tables -n -t mangle -L NEW_IPSEC_CONN >/dev/null 2>&1); then
	    ip6tables -t mangle -N NEW_IPSEC_CONN
	fi

	# initialize the IPSEC chain if needed
	if [ "${PLUTO_SAREF_TRACKING}" = "conntrack" ]; then
	    if [ "$(iptables -n -t mangle -L IPSEC | wc -l )" != 6 ]; then
		iptables -t mangle -F IPSEC
		iptables -t mangle -A IPSEC -j CONNMARK --restore-mark
		iptables -t mangle -A IPSEC -m mark --mark 0x80000000/0x80000000 -j RETURN
		iptables -t mangle -A IPSEC -j NEW_IPSEC_CONN
		iptables -t mangle -A IPSEC -j CONNMARK --save-mark
	    fi
	    if [ "$(ip6tables -n -t mangle -L IPSEC | wc -l )" != 6 ]; then
		ip6tables -t mangle -F IPSEC
		ip6tables -t mangle -A IPSEC -j CONNMARK --restore-mark
		ip6tables -t mangle -A IPSEC -m mark --mark 0x80000000/0x80000000 -j RETURN
		ip6tables -t mangle -A IPSEC -j NEW_IPSEC_CONN
		ip6tables -t mangle -A IPSEC -j CONNMARK --save-mark
	    fi
	else
	    if [ "$(iptables -n -t mangle -L IPSEC | wc -l )" != 3 ]; then
		iptables -t mangle -F IPSEC
		iptables -t mangle -A IPSEC -j NEW_IPSEC_CONN
	    fi
	    if [ "$(ip6tables -n -t mangle -L IPSEC | wc -l )" != 3 ]; then
		ip6tables -t mangle -F IPSEC
		ip6tables -t mangle -A IPSEC -j NEW_IPSEC_CONN
	    fi
	fi

	# next, setup routing rules and tables:
	# we pick table 50, cause proto50=ESP
	if ! ( ip rule show | grep -qF 'from all fwmark 0x80000000/0x80000000 lookup 50' ); then
	    # note "fwmarkmask" is an (obsolete) Libreswan patch to "ip" command.
	    # note2: iproute2-2.6.22-070710 supports mask via /mask notation instead
	    # ip rule add fwmark 0x80000000 fwmarkmask 0x80000000 table 50
	    ip rule add from all fwmark 0x80000000/0x80000000 lookup 50
	    # This rule makes sure that packets originating from mast0 (ones that came
	    # out of a tunnel) go directly to the main table.  This makes sure that
	    # rp_filter can find the right reverse path route.
	    ip rule add from all iif ${PLUTO_INTERFACE} lookup main
	fi

	# the default route goes over the mast interface
	if ! ( ip route show table 50 | grep -qF "default dev ${PLUTO_INTERFACE}" ); then
	    ip route add default dev ${PLUTO_INTERFACE} table 50
	fi

	# now look for -j IPSEC in OUTPUT chains.
	if ! (iptables -n -t mangle -L OUTPUT | grep -q '^IPSEC'); then
	    iptables -t mangle -I OUTPUT 1 -j IPSEC
	    iptables -t mangle -I OUTPUT 1 -p udp --sport 500 -j ACCEPT
	    iptables -t mangle -I OUTPUT 1 -p udp --dport 500 -j ACCEPT
	    iptables -t mangle -I OUTPUT 1 -p udp --sport 4500 -j ACCEPT
	    iptables -t mangle -I OUTPUT 1 -p udp --dport 4500 -j ACCEPT
	fi
	if ! (ip6tables -n -t mangle -L OUTPUT | grep -q '^IPSEC'); then
	    ip6tables -t mangle -I OUTPUT 1 -j IPSEC
	    ip6tables -t mangle -I OUTPUT 1 -p udp --sport 500 -j ACCEPT
	    ip6tables -t mangle -I OUTPUT 1 -p udp --dport 500 -j ACCEPT
	    ip6tables -t mangle -I OUTPUT 1 -p udp --sport 4500 -j ACCEPT
	    ip6tables -t mangle -I OUTPUT 1 -p udp --dport 4500 -j ACCEPT
	fi

	# now look for -j IPSEC in PREROUTING chains.
	if ! (iptables -n -t mangle -L PREROUTING | grep -q '^IPSEC'); then
	    iptables -t mangle -I PREROUTING 1 -j IPSEC
	fi
	if ! (ip6tables -n -t mangle -L PREROUTING | grep -q '^IPSEC'); then
	    ip6tables -t mangle -I PREROUTING 1 -j IPSEC
	fi

	if [ -w /proc/sys/net/ipv4/conf/${PLUTO_INTERFACE}/src_valid_mark ]; then
	    # finally make sure that the top bit of source vmark for mast0 is set
	    vmark=$(cat /proc/sys/net/ipv4/conf/${PLUTO_INTERFACE}/src_valid_mark)
	    vmark=$(( ${vmark} | 0x80000000 ))
	    echo "${vmark}" > /proc/sys/net/ipv4/conf/${PLUTO_INTERFACE}/src_valid_mark
	else
	    # In case that we don't have the means to get rp_filter to cooperate
	    # with KLIPS nfmark based routing scheme, we disable rp_filter.
	    for n in /proc/sys/net/ipv4/conf/*/rp_filter; do
		echo 0 > ${n}
	    done
	fi
    fi
}

# utility functions for route manipulation

# called to add appropriate "erout'ing"
uproute() {
	checkipsec
	doipsecrule add
	ip route flush cache
}

# called to remove any routing
downroute() {
	checkipsec
	doipsecrule delete
	ip route flush cache
}

# called XXXX
uprule() {
    doipsecrule delete
    doipsecrule add
    ip route flush cache
}

# called XXXX
downrule() {
    doipsecrule delete
}

updateresolvconf() {
	if [ -z "${PLUTO_PEER_DNS_INFO}" -o -z "${PLUTO_PEER_DOMAIN_INFO}" ]; then
		return 0
	fi

	if [ -n "$(pidof unbound)" ]; then
	    echo "updating local nameserver for ${PLUTO_PEER_DOMAIN_INFO} with ${PLUTO_PEER_DNS_INFO}"
	    /usr/sbin/unbound-control forward_add ${PLUTO_PEER_DOMAIN_INFO} ${PLUTO_PEER_DNS_INFO}
	    /usr/sbin/unbound-control flush_zone ${PLUTO_PEER_DOMAIN_INFO}
	    /usr/sbin/unbound-control flush_requestlist
	    return 0
	fi

	if [ -z "${PLUTO_NM_CONFIGURED}" -o "${PLUTO_NM_CONFIGURED}" = 0 ]; then
		echo "updating resolvconf"

		if [ ! -e "${ORIG_RESOLV_CONF}" ]; then
			echo "resolv.conf does not exist, so doing nothing"
			return 1
		fi

		if [ -e "${LIBRESWAN_RESOLV_CONF}" ]; then
			if grep 'Libreswan' ${ORIG_RESOLV_CONF} > /dev/null 2>&1; then
				echo "Current resolv.conf is generated by Libreswan, and backup resolv.conf already exists, so doing nothing"
				return 1
			else
				echo "backup resolv.conf exists, but current resolv.conf is not generated by Libreswan"
			fi
		fi

		rm -f ${LIBRESWAN_RESOLV_CONF}
		cp -- ${ORIG_RESOLV_CONF} ${LIBRESWAN_RESOLV_CONF}

		RESOLVE_CONF="# Generated by Libreswan (IPSec)"

		if [ -n "${PLUTO_PEER_DOMAIN_INFO}" ]; then
			if grep 'domain' ${ORIG_RESOLV_CONF} > /dev/null 2>&1; then
				RESOLVE_CONF="${RESOLVE_CONF}\ndomain ${PLUTO_PEER_DOMAIN_INFO}\nsearch ${PLUTO_PEER_DOMAIN_INFO}"
			else
				RESOLVE_CONF="${RESOLVE_CONF}\nsearch ${PLUTO_PEER_DOMAIN_INFO}"
			fi
		fi

		if [ -n "${PLUTO_PEER_DNS_INFO}" ]; then
			for i in ${PLUTO_PEER_DNS_INFO}; do
				RESOLVE_CONF="${RESOLVE_CONF}\nnameserver $i"
			done
		fi

		ORIG_NAMESERVER=$(grep -m 1 ^nameserver ${ORIG_RESOLV_CONF})
		RESOLVE_CONF="${RESOLVE_CONF}\n${ORIG_NAMESERVER}\n"

		rm -f -- ${ORIG_RESOLV_CONF}
		printf "${RESOLVE_CONF}" > ${ORIG_RESOLV_CONF}
		return $?

	else
		echo "Updating resolv.conf is controlled by Network Manager"
		libreswan_reason=connect
		export libreswan_reason
		export PLUTO_PEER_DOMAIN_INFO
		export PLUTO_PEER_DNS_INFO
		export PLUTO_PEER_BANNER
		export PLUTO_MY_SOURCEIP
		export PLUTO_PEER
		/usr/libexec/nm-libreswan-service-helper
		return 0
	fi
}

restoreresolvconf() {
	if [ -z "${PLUTO_PEER_DNS_INFO}" -o -z "${PLUTO_PEER_DOMAIN_INFO}" ]; then
		return 0
	fi

	if [ -n "$(pidof unbound)" ]; then
		echo "flushing local nameserver of ${PLUTO_PEER_DOMAIN_INFO}"
		/usr/sbin/unbound-control forward_remove ${PLUTO_PEER_DOMAIN_INFO}
		/usr/sbin/unbound-control flush_zone ${PLUTO_PEER_DOMAIN_INFO}
		/usr/sbin/unbound-control flush_requestlist
		return 0
	fi

	if [ -z "${PLUTO_NM_CONFIGURED}" -o "${PLUTO_NM_CONFIGURED}" = 0 ]; then
		echo "restoring resolvconf"
		if [ ! -e "${LIBRESWAN_RESOLV_CONF}" ]; then
			echo "Problem in restoring the resolv.conf, as there is no backup file"
			return 2
		fi

		if grep 'Libreswan' ${ORIG_RESOLV_CONF} > /dev/null 2>&1; then
			cp -- "${LIBRESWAN_RESOLV_CONF}" ${ORIG_RESOLV_CONF}
		else
			echo "Current resolv.conf is not generated by Libreswan, so doing nothing"
		fi

		rm -f -- "${LIBRESWAN_RESOLV_CONF}"
		return 0
	else
		# Here disconnect signal is sent to NetworkManager
		# whenever an already established connection is being terminated.
		unset libreswan_reason
		unset PLUTO_PEER_DOMAIN_INFO
		unset PLUTO_PEER_DNS_INFO
		unset PLUTO_PEER_BANNER
		unset PLUTO_MY_SOURCEIP
		unset PLUTO_PEER
		echo "Restoring resolv.conf is controlled by Network Manager"
		disconnectNM
	fi
}

disconnectNM() {
    # This will be called whenever a connection fails to establish
    # due to a state (either phase 1, xauth phase, or phase 2) fails.
    # This will send a singal to NetworkManager over dbus so that NM
    # can clear up coonnections.
    libreswan_reason=disconnect
    export libreswan_reason
    echo "sending disconnect signal to NetworkManager"
    /usr/libexec/nm-libreswan-service-helper
    return 0
}

addsource() {
    st=0
    # check if given sourceip is local and add as alias if not
    if ! ip -o route get ${PLUTO_MY_SOURCEIP%/*} | grep -q ^local; then
	it="ip addr add ${PLUTO_MY_SOURCEIP%/*}/32 dev ${PLUTO_INTERFACE%:*}"
	oops="$(eval ${it} 2>&1)"
	st=$?
	if [ -z "${oops}" -a ${st} -ne 0 ]; then
	    oops="silent error, exit status ${st}"
	fi
	case "${oops}" in
	    'RTNETLINK answers: File exists'*)
		# should not happen, but ... ignore if the
		# address was already assigned on interface
		oops=""
		st=0
		;;
	esac
	if [ -n "${oops}" -o ${st} -ne 0 ]; then
	    echo "${0}: addsource \"${it}\" failed (${oops})" >&2
	fi
    fi
    return ${st}
}

# WARNING: changesource might not work as expected with mast
changesource() {
    st=0
    parms="${PLUTO_PEER_CLIENT}"
    parms2="dev ${PLUTO_INTERFACE}"
    parms3="src ${PLUTO_MY_SOURCEIP%/*}"
    if [ -n "${IPROUTETABLE}" ]; then
	parms3="${parms3} table ${IPROUTETABLE}"
    fi
    it="ip route replace ${parms} ${parms2} ${parms3}"
    case "${PLUTO_PEER_CLIENT}" in
 	"0.0.0.0/0"|"::/0")
	    # opportunistic encryption work around
	    it=
 	    ;;
    esac
    oops="$(eval ${it} 2>&1)"
    st=$?
    if [ -z  "${oops}" -a ${st} -ne 0 ]; then
	oops="silent error, exit status ${st}"
    fi
    if [ -n "${oops}" -o ${st} -ne 0 ]; then
	echo "${0}: changesource \"${it}\" failed (${oops})" >&2
    fi
    return ${st}
}

# the purpose of this command is to add an entry to the NEW_IPSEC_CONN chain
# in the iptables system. It grabs the right packets and does a --set-mark
# on them. An advanced routing rule then directs the packets to the
# appropriate device with the right mark.
#
# This is not be done for OE packets --- they are supposed to get a
# new netfilter module instead.
doipsecrule() {
    if [ -z "${PLUTO_SAREF_TRACKING}" -o "${PLUTO_SAREF_TRACKING}" = "no" ]; then
	echo "SAref tracking left to third party"
    elif [ -z "${PLUTO_CONN_ADDRFAMILY}" -o "${PLUTO_CONN_ADDRFAMILY}" = "ipv6" ]; then
	echo "SAref not activated for IPv6"
    else
	saref=${PLUTO_PEER_REF}
	nf_saref=$(printf "0x%x0000" $(( ${saref} | 0x8000 )))

	srcnet=${PLUTO_MY_CLIENT_NET}/${PLUTO_MY_CLIENT_MASK}
	dstnet=${PLUTO_PEER_CLIENT_NET}/${PLUTO_PEER_CLIENT_MASK}

	#echo SAref: ${saref} '->' ${nf_saref}

	rulespec="--src ${srcnet} --dst ${dstnet} -m mark --mark 0/0x80000000 -j MARK --set-mark ${nf_saref}"
	if ${use_comment}; then
	    # WARNING: you should only edit use_comment while you have no established conns
	    rulespec="${rulespec} -m comment --comment '${PLUTO_CONNECTION}'"
	fi

	case ${1} in
	    add)
		it4="iptables -t mangle -I NEW_IPSEC_CONN 1 ${rulespec}"
		it6="ip6tables -t mangle -I NEW_IPSEC_CONN 1 ${rulespec}"
		;;
	    delete)
		it4="iptables -t mangle -D NEW_IPSEC_CONN ${rulespec}"
		it6="ip6tables -t mangle -D NEW_IPSEC_CONN ${rulespec}"
		;;
	esac

	oops="$(set +x; eval ${it4}; eval ${it6}; 2>&1)"
	st=$?
	if [ -z  "${oops}" -a ${st} -ne 0 ]; then
	    oops="silent error, exit status ${st}"
	fi
	if [ -n "${oops}" -o ${st} -ne 0 ]; then
	    echo "${0}: doipsecrule \"${it4}\" or \"${it6}\" failed (${oops})" >&2
	fi
	return ${st}
    fi
}


# the big choice
case "${PLUTO_VERB}:${1}" in
    spdadd-client:*|spdadd-host:*)
	checkipsec;
	doipsecrule add;;

    spddel-client:*|spddel-host:*)
	checkipsec
	doipsecrule delete;;

    prepare-host:*|prepare-client:*)
	# set up a "%trap" equivalent (we don't know how do this yet!)
	;;

    route-host:*|route-client:*)
	# connection to me or my client subnet being routed
	# setup of %TRAP equivalent
	;;

    unroute-host:*|unroute-client:*)
	# connection to me or my client subnet being unrouted
	# remove %TRAP equivalent
	;;

    up-host:*)
	# If you are doing a custom version, firewall commands go here.
	;;

    down-host:*)
	# If you are doing a custom version, firewall commands go here.
	;;

    up-client:)
	# If you are doing a custom version, firewall commands go here.
	updateresolvconf
	;;
    down-client:)
	# If you are doing a custom version, firewall commands go here.
	restoreresolvconf
	;;
    disconnectNM-host|disconnectNM-client)
	# sending disconnect signal to NM, as something went wrong.
	disconnectNM
	;;
    #
    # IPv6
    #
    prepare-host-v6:*|prepare-client-v6:*)
	;;
    route-host-v6:*|route-client-v6:*)
	# connection to me or my client subnet being routed
	#uproute_v6
	;;
    unroute-host-v6:*|unroute-client-v6:*)
	# connection to me or my client subnet being unrouted
	#downroute_v6
	;;
    up-host-v6:*)
	# connection to me coming up
	# If you are doing a custom version, firewall commands go here.
	;;
    down-host-v6:*)
	# connection to me going down
	# If you are doing a custom version, firewall commands go here.
	;;
    up-client-v6:)
	# connection to my client subnet coming up
	# If you are doing a custom version, firewall commands go here.
	;;
    down-client-v6:)
	# connection to my client subnet going down
	# If you are doing a custom version, firewall commands go here.
	;;
    *)
	echo "${0}: unknown verb \"${PLUTO_VERB}\" or parameter \"${1}\"" >&2
	exit 1
	;;
esac