#!/bin/sh
#
# ip-up.ipv6to4
#
#
# Taken from:
# (P) & (C) 2000-2005 by Peter Bieringer <pb@bieringer.de>
#
#  You will find more information on the initscripts-ipv6 homepage at
#   http://www.deepspace6.net/projects/initscripts-ipv6.html
#
# Version: 2005-09-22
#
# Calling parameters:
#  $1: interface name
#
# Called (mostly) by /etc/ppp/ip-up.local
#  like: /etc/ppp/ip-up.ipv6to4 $1 >>/var/log/ppp-ipv6to4.log 2>&1
#
# Note: this script will *kill* older still existing 6to4 tunnels regardless
#        whether they were set before by another device
#
# Uses following information from /etc/sysconfig/network-scripts/ifcfg-$1:
#  IPV6TO4INIT=yes|no: controls configuration
#  IPV6TO4_IPV4ADDR=<IPv4 address>: special local address for 6to4 tunneling (only needed behind a NAT gateway)
#  IPV6TO4_RELAY=<IPv4 address>: remote 6to4 relay router address (default: 192.88.99.1)
#  IPV6TO4_MTU=<MTU for IPv6>: controls IPv6 MTU for the 6to4 link (optional, default is MTU of interface - 20)
#  IPV6TO4_ROUTING="<device>-<suffix>/<prefix length> ...": information to setup additional interfaces
#    Example: IPV6TO4_ROUTING="eth0-:f101::1/64 eth1-:f102::1/64"
#
#  IPV6_CONTROL_RADVD=yes|no: controls radvd triggering
#  IPV6_RADVD_PIDFILE=<file>: PID file of radvd for sending signals, default is "/var/run/radvd/radvd.pid"
#  IPV6_RADVD_TRIGGER_ACTION=startstop|reload|restart|SIGHUP: how to trigger radvd (optional, default is SIGHUP)
#
# Requirements
#  radvd-0.6.2p3 or newer supporting option "Base6to4Interface"
#


if [ -z "$1" ]; then
	echo $"Argument 1 is empty but should contain interface name - skip IPv6to4 initialization"
	exit 1
fi

# Get global network configuration
. /etc/sysconfig/network

# Source IPv4 helper functions
cd /etc/sysconfig/network-scripts
. ./network-functions

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

# IPv6 don't need aliases anymore, config is skipped
REALDEVICE=$(echo ${DEVICE} | sed 's/:.*//g')
[ "$DEVICE" != "$REALDEVICE" ] && exit 0

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

. /etc/sysconfig/network-scripts/network-functions-ipv6


# Run basic IPv6 test (and make sure the ipv6 module will be loaded), if not ok, skip IPv6 initialization
ipv6_test || exit 1

# Setup of 6to4, if configured
valid6to4config="yes"
if [ "$IPV6TO4INIT" = "yes" ]; then
	if [ -n "$IPV6TO4_IPV4ADDR" ]; then
		# Take 6to4-dedicated configured IPv4 address from config file (precedence 1)
		ipv4addr="$IPV6TO4_IPV4ADDR"
        else
		# Get IPv4 address from interface (precedence 2)
		ipv4addr="$(ipv6_get_ipv4addr_of_device $DEVICE)"
		if [ -z "$ipv4addr" ]; then
                	# Take configured IPv4 address of interface from config file (precedence 3)
                	ipv4addr="$IPADDR"
            	fi
        fi
        if [ -n "$ipv4addr" ]; then
		# Test for non-global IPv4 address
		if ! ipv6_test_ipv4_addr_global_usable $ipv4addr; then
                	echo $"Given IPv4 address '$ipv4addr' is not globally usable"
			valid6to4config="no"
		fi
	else
		echo $"IPv6to4 configuration needs an IPv4 address on related interface or otherwise specified"
		valid6to4config="no"
	fi
	if [ -z "$IPV6TO4_RELAY" ]; then
		IPV6TO4_RELAY="192.88.99.1"
       	fi

	# Check/generate relay address
	ipv6to4_relay="$(ipv6_create_6to4_relay_address $IPV6TO4_RELAY)"
	if [ $? -ne 0 ]; then
		valid6to4config="no"
	fi

	if [ "$valid6to4config" = "yes" ]; then
		# Delete routes to local networks
       		for devsuf in $IPV6TO4_ROUTING; do
			dev="$(echo $devsuf | awk -F- '{ print $1 }')"
			ipv6_cleanup_6to4_device $dev
		done

		# Cleanup all old data (needed, if "ip-down.ipv6to4" wasn't executed), delete all configured 6to4 address
		ipv6_cleanup_6to4_tunnels tun6to4

		# Get MTU of master device
		ipv4mtu="$(ipv6_exec_ip link show dev $DEVICE | grep -w "mtu" | awk '{ print $5 }')"
		if [ -n "$ipv4mtu" ]; then
			# IPv6 tunnel MTU is IPv4 MTU minus 20 for IPv4 header
			tunnelmtu=$[ $ipv4mtu - 20 ]
		fi

		if [ -n "$IPV6TO4_MTU" ]; then
			if [ $IPV6TO4_MTU -gt $tunnelmtu ]; then
				echo $"Warning: configured MTU '$IPV6TO4_MTU' for 6to4 exceeds maximum limit of '$tunnelmtu', ignored"
			else
				tunnelmtu=$IPV6TO4_MTU
			fi
		fi

		# Setup new data
		ipv6_add_6to4_tunnel tun6to4 $ipv4addr "" $tunnelmtu || exit 1

		# Add route to for compatible addresses (removed later again)
		ipv6_add_route "::/96" "::" tun6to4

		# Add default route, if device matches
		if [ "$IPV6_DEFAULTDEV" = "tun6to4" ]; then
			if [ -n "$IPV6_DEFAULTGW" ]; then
				echo $"Warning: interface 'tun6to4' does not support 'IPV6_DEFAULTGW', ignored"
			fi
			ipv6_set_default_route $ipv6to4_relay tun6to4
		fi

		# Add static routes
		if [ -f /etc/sysconfig/static-routes-ipv6 ]; then
			LC_ALL=C grep -w "^tun6to4" /etc/sysconfig/static-routes-ipv6 | while read device network gateway; do
				if [ -z "$network" ]; then
					continue
				fi
				if [ -z "$gateway" ]; then
					gateway="$ipv6to4_relay"
				fi
				ipv6_add_route $network $gateway tun6to4
			done
		fi

                # Setup additional static IPv6 routes (newer config style)
		if [ -f "/etc/sysconfig/network-scripts/route6-tun6to4" ]; then
			cat "/etc/sysconfig/network-scripts/route6-tun6to4" | sed 's/#.*//g' | grep -v '^[[:space:]]*$' | while read line; do
				if echo "$line" | grep -vq 'via'; then
					# Add gateway if missing
					line="$line via $ipv6to4_relay"
				fi
				ipv6_exec_ip -6 route add $line
			done
                fi

		# Cleanup autmatically generated autotunnel (not needed for 6to4)
		/sbin/ip -6 route del ::/96 dev tun6to4
		/sbin/ip -6 addr del tun6to4 "::$ipv4addr/128" dev tun6to4

	        if [ "$IPV6_CONTROL_RADVD" = "yes" ]; then
                        # Control running radvd
			ipv6_trigger_radvd up "$IPV6_RADVD_TRIGGER_ACTION" $IPV6_RADVD_PIDFILE

			if [ -n "$IPV6TO4_ROUTING" ]; then
				# Generate 6to4 address
				ipv6to4prefix="$(ipv6_create_6to4_prefix $ipv4addr)"
				if [ -n "$ipv6to4prefix" ]; then
					# Add IPv6 address to interface (required interface route will be set automatically)
					for devsuf in $IPV6TO4_ROUTING; do
						dev="$(echo $devsuf | awk -F- '{ print $1 }')"
						suf="$(echo $devsuf | awk -F- '{ print $2 }')"
						ipv6_add_addr_on_device ${dev} ${ipv6to4prefix}${suf}
					done
				else
					echo $"Error occured while calculating the IPv6to4 prefix"
				fi
			else
				echo $"radvd control enabled, but config is not complete"
			fi
		fi
	fi
fi