#!/bin/sh
# Script to set up one of the nodes as a NAT gateway for all other nodes.
# This is used to ensure that all nodes in the cluster can still originate
# traffic to the external network even if there are no public addresses
# available.
#

. $CTDB_BASE/functions
loadconfig ctdb

[ -z "$NATGW_PUBLIC_IFACE" ] && exit 0

cmd="$1"
shift
PATH=/usr/bin:/bin:/usr/sbin:/sbin:$PATH

delete_all() {
	ip addr add $NATGW_PUBLIC_IP dev $NATGW_PUBLIC_IFACE >/dev/null 2>/dev/null
	ip addr del $NATGW_PUBLIC_IP_HOST dev $NATGW_PRIVATE_IFACE >/dev/null 2>/dev/null
	ip route del 0.0.0.0/0 metric 10 >/dev/null 2>/dev/null

	# Delete the masquerading setup from a previous iteration where we
	# were the NAT-GW
	iptables -D POSTROUTING -t nat -s $NATGW_PRIVATE_NETWORK -d ! $NATGW_PRIVATE_NETWORK -j MASQUERADE >/dev/null 2>/dev/null

	ip addr del $NATGW_PUBLIC_IP dev $NATGW_PUBLIC_IFACE >/dev/null 2>/dev/null
}

case $cmd in 
     recovered)
	MYPNN=`ctdb pnn | cut -d: -f2`

	# Find the first connected node
	FIRST=`ctdb status -Y | grep ":0:$" | head -1`
	FIRSTNODE=`echo $FIRST | cut -d: -f2`
	FIRSTIP=`echo $FIRST | cut -d: -f3`
	NATGW_PUBLIC_IP_HOST=`echo $NATGW_PUBLIC_IP | sed -e "s/\/.*/\/32/"`

	delete_all

	if [ "$FIRSTNODE" == "$MYPNN" ]; then
		# This is the first node, set it up as the NAT GW
		echo 1 >/proc/sys/net/ipv4/ip_forward
		iptables -A POSTROUTING -t nat -s $NATGW_PRIVATE_NETWORK -d ! $NATGW_PRIVATE_NETWORK -j MASQUERADE
		ip addr add $NATGW_PUBLIC_IP dev $NATGW_PUBLIC_IFACE
		ip route add 0.0.0.0/0 via $NATGW_DEFAULT_GATEWAY >/dev/null 2>/dev/null
	else
		# This is not the NAT-GW
		# Assign the public ip to the private interface and make
		# sure we dont respond to ARPs.
		# We do this so that the ip address will exist on a
		# non-loopback interface so that samba may send it along in the
		# KDC requests.
		ip addr add $NATGW_PUBLIC_IP_HOST dev $NATGW_PRIVATE_IFACE
		ip route add 0.0.0.0/0 via $FIRSTIP metric 10
	fi
	;;

     shutdown)
	delete_all
	;;

esac

exit 0