#!/bin/sh
#
# ifdown-ipv6
#
#
# Taken from:
# (P) & (C) 2000-2001 by Peter Bieringer <pb@bieringer.de>
#
# RHL integration assistance by Pekka Savola <pekkas@netcore.fi>
#
# Version 2001-07-15
#
# Uses following information from /etc/sysconfig/network:
#  NETWORKING_IPV6=yes|no: controls IPv6 initialization (global setting)
#
# Uses following information from /etc/sysconfig/network-scripts/ifcfg-$1:
#  IPV6INIT=yes|no: controls IPv6 configuration for this interface
#
# Optional for 6to4 tunneling:
#  IPV6TO4_RELAY=<ipv4address>: IPv4 address of the remote 6to4 relay
#  IPV6TO4_ROUTING="eth0-:f101::0/64 eth1-:f102::0/64": information to setup local subnetting
#  IPV6TO4_CONTROL_RADVD=yes|no: controls radvd triggering [optional]
#  IPV6TO4_RADVD_PIDFILE=file: PID file of radvd for sending signals, default is "/var/run/radvd/radvd.pid" [optional]
#
#  Requirements for 6to4 if using radvd:
#   radvd-0.6.2p3 or newer supporting option "Base6to4Interface"
#


. /etc/sysconfig/network 

cd /etc/sysconfig/network-scripts
. network-functions 

CONFIG=$1
[ -f "$CONFIG" ] || CONFIG=ifcfg-$CONFIG
source_config                                                                   

# Test whether IPv6 should be configured, else stop
[ "${NETWORKING_IPV6}" = "yes" ] || exit 0

if [ ! -f /etc/sysconfig/network-scripts/network-functions-ipv6 ]; then
	exit 1
fi

# Source IPv6 helper functions
. /etc/sysconfig/network-scripts/network-functions-ipv6

# IPv6 test, no module loaded, exit if system is not IPv6-ready
test_ipv6 testonly || exit 0


# Switch some sysctls to secure mode
sysctl -w net.ipv6.conf.$DEVICE.forwarding=0 >/dev/null
sysctl -w net.ipv6.conf.$DEVICE.accept_ra=0 >/dev/null
sysctl -w net.ipv6.conf.$DEVICE.accept_redirects=0 >/dev/null

# Shutdown of 6to4, if configured
valid6to4config="yes"
if [ -z "$IPV6TO4_RELAY" ]; then
	valid6to4config="no"
fi
if [ "$valid6to4config" = "yes" ]; then
	if [ "$IPV6TO4_CONTROL_RADVD" = "yes" ]; then
		# stop RADVD from distributing no longer usable 6to4 prefixes
		if [ -z "$IPV6TO4_RADVD_PIDFILE" ]; then
			IPV6TO4_RADVD_PIDFILE="/var/run/radvd/radvd.pid"
		fi
		# Send SIGHUP to radvd
		if [ -f "$IPV6TO4_RADVD_PIDFILE" ]; then
			pid="`cat $IPV6TO4_RADVD_PIDFILE`"
			if [ ! -z "$pid" ]; then
				#  still waiting for feature enabling: stopping distribution of prefixes in RADVD....
				# kill -SOMETHING $pid
				false
			else
				false
			fi
		fi
	fi

	if [ ! -z "$IPV6TO4_ROUTING" ]; then
		# Delete routes to local networks
		for devsuf in $IPV6TO4_ROUTING; do
			dev="`echo $devsuf | awk -F- '{ print $1 }'`"
			ifdown_ipv6_route_all $dev ::
		done
	fi

	# Detect type of address, whether it is IPv4 or IPv6
	if testipv6_valid $IPV6TO4_RELAY; then
		relay6to4type="ipv6"
	fi

	# Delete all static IPv6to4 routes
	if [ "$relay6to4type" = "ipv6" ]; then	
		ifdown_ipv6_route_all sit0 $IPV6TO4_RELAY
	else
		ifdown_ipv6_route_all sit0 ::$IPV6TO4_RELAY
	fi

	# Delete old 6to4 routes, even if IPV6TO4_RELAY was changed
	if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
		grep -w "^sit0" /etc/sysconfig/static-routes-ipv6 | while read device network dummy; do
			if [ "$EXISTS_ipv6calc" = "yes" ]; then
				# Convert given network to compressed one
				network="`ipv6calc  --addr_to_compressed $network`"
			fi
			LC_ALL=C route -A inet6 | grep "^$network" | while read destination nexthop flags metric ref use iface dummy; do
				if ! [ "$device" = "$iface" -a "$network" = "$destination" ]; then
					continue
				fi
				# Look for routes to a compatible IPv4 address, delete them
				if echo $nexthop | egrep -q '^::[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'; then
					ifdown_ipv6_route $destination $nexthop $iface
				fi
				# Look for routes to a IPv6to4 address, delete them
				if echo $nexthop | egrep -q '^2002::'; then
					ifdown_ipv6_route $destination $nexthop $iface
				fi
			done
		done
	fi

	# Delete 6to4 route
	ifdown_ipv6_route 2002::/16 :: sit0

	# Delete all configured 6to4 address
	ifdown_ipv6to4_all sit0 
fi

# Delete all current configured IPv6 addresses on this interface 
ifdown_ipv6_real_all $DEVICE