6rd net module

ip6rd.sh (text/plain), 3.47 KB, created by Christopher Byrne on 2011-11-28 09:15:37 UTC

_config_vars="$_config_vars link prefix ipv4mask suffix relay"

ip6rd_inet_atoi()
{
        local IFS="${IFS}." ipi=0 j=3
        for i in $1 ; do
               ipi=$(( ipi | i << 8*j-- ))
        done
        echo ${ipi}
}

ip6rd_inet_itoa()
{
        local ipi=$1
        for i in 0 1 2 3; do
                if [ $i != 3 ] ; then
                        printf "%d." $(( (ipi & ~((1<<24)-1)) >> 24 ))
                        ipi=$(( (ipi & ((1<<24)-1)) << 8))
                else
                        printf "%d\n" $(( (ipi & ~((1<<24)-1)) >> 24 ))
                fi
        done
}

ip6rd_inet_get_network()
{
	echo ip6rd_inet_itoa $(( ($(ip6rd_inet_atoi $1) & ((1<<32-$2)-1))  << $2 ))
}

ip6rd_inet_is_private_network()
{
	if [ "$(ip6rd_inet_get_network $1 24)" = "192.168.0.0" ]\
	  || [ "$(ip6rd_inet_get_network $1 8)" = "10.0.0.0" ]\
 	  || [ "$(ip6rd_inet_get_network $1 12)" = "172.16.0.0" ]\
          || [ "$(ip6rd_inet_get_network $1 16)" = "169.254.0.0" ]
	then
		return 0;
	fi
	return 1;
}

ip6rd_prefix_shave_bits()
{
	local ipi=
 	ipi=$((  ($(ip6rd_inet_atoi $1) & (1<<(32-$2))-1) << $2))
	if [ $2 -le 16 ]
	then
		printf "%04x:%0$(( (16-$2>>2)+(($2%4)?1:0) ))x" \
		$((ipi >> 16)) $((ipi & (1<<(16-$2))-1))
	elif [ $2 -lt 32 ]
	then
        	printf "%0$(( (32-$2>>2)+(($2%4)?1:0) ))x" \
        	$((ipi >> 16))
        fi	
}

ip6rd_depend()
{
	after interface
	after dhcp
}

ip6rd_start()
{
        case "${MODULES}" in
                *" ifconfig "*)
			eerror "ifconfig is not supported for 6rd"
			eerror "Please emerge sys-apps/iproute2"
			return 1
	esac

	if [ "${IFACE}" == "sit0" ]; then
		error "sit0 cannot be a 6rd tunnel. Please choose another name"
		return 1
	fi

	local host= prefix= suffix= addr= iface=${IFACE} new= localip= relay= ipv4mask=

	eval host=\$link_${IFVAR}
	eval prefix=\${prefix_${IFVAR}}
	eval ipv4mask=\${ipv4mask_${IFVAR}:0}
	eval suffix=\${suffix_${IFVAR}:-1}
	eval relay=\${relay_${IFVAR}}

	if [ -z "${host}" ]; then
		eerror "link_${IFVAR} not set"
		return 1
	fi

	if [ -z "${relay}" ]; then
		# TODO: support getting 6rd parameters vis DHCP (option 212)
		eerror "relay_${IFVAR} not set"
		return 1
	fi

	IFACE=${host}
	addrs=$(_get_inet_addresses)
	IFACE=${iface}
	if [ -z "${addrs}" ]; then
		eerror "${host} is not configured with an IPv4 address"
		return 1
	fi

	for addr in ${addrs}; do
		local ip="${addr%/*}" subnet=${addr#*/}

		# We don't work on private IPv4 addresses
		if ip6rd_inet_is_private_network ${ip}
		then
			continue
		fi

		veinfo "IPv4 address on ${host}: ${ip}/${subnet}"
		local ip6= ip6_prefix="${prefix%::/*}" ip6_subnet="${prefix#*/}"
		ip6_subnet=$((ip6_subnet + (32-ipv4mask)))
		eval ip6="$(printf "${ip6_prefix}:%s::%s" \
		$(ip6rd_prefix_shave_bits  ${ip} ${ipv4mask}) ${suffix})"
		veinfo "Derived IPv6 address: ${ip6}"

		# Now apply our IPv6 address to our config
		new="${new}${new:+ }${ip6}/${ip6_subnet}"

		if [ -n "${localip}" ]; then
			localip="any"
		else
			localip="${ip}"
		fi
	done

	if [ -z "${new}" ]; then
		eerror "No global IPv4 addresses found on interface ${host}"
		return 1
	fi

	ebegin "Creating 6rd tunnel on ${IFACE}"
	_tunnel add 6rd mode sit local "${localip}" ttl 255
	_tunnel 6rd dev "${IFACE}" 6rd-prefix ${prefix}
	eend $? || return 1
	_up

	# Now apply our config
	eval config_${config_index}=\'"${new}"\'
	: $(( config_index -= 1 ))

	# Add a route for us, ensuring we don't delete anything else
	local routes="$(_get_array "routes_${IFVAR}")
2003::/3 via ::${relay} metric 2147483647"
	eval routes_${IFVAR}=\$routes
}