pfSense

	case "6to4":

		if(does_interface_exist("$realif")) {

			mwexec("/sbin/ifconfig " . escapeshellarg($realif) . " delete", true);

			if ($destroy == true)

				pfSense_interface_flags($realif, -IFF_UP);

		}		

		break;

		case '6to4':

			interface_6to4_configure($interface);

			break;

function interface_6to4_configure($interface = "wan"){

	global $config, $g;

	$iflist = get_configured_interface_with_descr(false, true);

	/* because this is a tunnel interface we can only function 

	 *	with a public IPv4 address on the interface */

	$wancfg = $config['interfaces'][$interface];

	$wanif = $wancfg['if'];

	if (empty($wancfg))

		$wancfg = array();

	$wanif = get_real_interface($interface);

	$ip4address = find_interface_ip($wanif);

	if((!is_ipaddrv4($ip4address)) || (is_private_ip($ip4address))) {

		log_error("The interface IPv4 '{$ip4address}' address on interface '{$wanif}' is not public, not configuring 6RD tunnel");

		return false;

	}

	/* create the long prefix notation for math, save the prefix length */

	$stfprefixlen = 16;

	$stfprefix = Net_IPv6::uncompress("2002::");

	$stfarr = explode(":", $stfprefix);

	$v4prefixlen = "0";

	/* we need the hex form of the interface IPv4 address */

	$ip4arr = explode(".", $ip4address);

	$hexwanv4 = "";

	foreach($ip4arr as $octet)

		$hexwanv4 .= sprintf("%02x", $octet);

	/* we need the hex form of the broker IPv4 address */

	$ip4arr = explode(".", "192.88.99.1");

	$hexbrv4 = "";

	foreach($ip4arr as $octet)

		$hexbrv4 .= sprintf("%02x", $octet);

	/* binary presentation of the prefix for all 128 bits. */

	$stfprefixbin = "";

	foreach($stfarr as $element) {

		$stfprefixbin .= sprintf("%016b", hexdec($element));

	}

	/* just save the left prefix length bits */

	$stfprefixstartbin = substr($stfprefixbin, 0, $stfprefixlen);

	/* if the prefix length is not 32 bits we need to shave bits off from the left of the v4 address. */

	$stfbrokerbin = substr(sprintf("%032b", hexdec($hexbrv4)), $v4prefixlen, 32);

	$stfbrokerbin = str_pad($stfprefixstartbin . $stfbrokerbin, 128, "0", STR_PAD_RIGHT);;

	/* for the local subnet too. */

	$stflanbin = substr(sprintf("%032b", hexdec($hexwanv4)), $v4prefixlen, 32);

	$stflanbin = str_pad($stfprefixstartbin . $stflanbin, 128, "0", STR_PAD_RIGHT);;

	/* convert the 128 bits for the broker address back into a valid IPv6 address */ 

	$stfbrarr = array();

	$stfbrbinarr = array();

	$stfbrbinarr = str_split($stfbrokerbin, 16);

	foreach($stfbrbinarr as $bin)

		$stfbrarr[] = dechex(bindec($bin));

	$stfbrarr[7] = 1;

	$stfbrgw = Net_IPv6::compress(implode(":", $stfbrarr));

	/* convert the 128 bits for the broker address back into a valid IPv6 address */ 

	$stflanarr = array();

	$stflanbinarr = array();

	$stflanbinarr = str_split($stflanbin, 16);

	foreach($stflanbinarr as $bin)

		$stflanarr[] = dechex(bindec($bin));

	$stflanpr = Net_IPv6::compress(implode(":", $stflanarr));

	$stflanarr[7] = 1;

	$stflan = Net_IPv6::compress(implode(":", $stflanarr));

	/* setup the stf interface */

	mwexec("/sbin/ifconfig stf0 destroy");

	mwexec("/sbin/ifconfig stf0 create");

	mwexec("/sbin/ifconfig stf0 inet6 {$stflanpr} prefixlen 16");

	log_error("Set IPv6 address inet6 {$stflanpr} prefixlen 16 for stf0, route {$stfbrgw}");

	/* write out a default router file */

	file_put_contents("{$g['tmp_path']}/{$wanif}_routerv6", "{$stfbrgw}");

	file_put_contents("{$g['tmp_path']}/{$wanif}_defaultgwv6", "{$stfbrgw}");

	return 0;

}