#!/usr/bin/php
<?php

// file positionen
define('NEWFILE', 'http://10.10.254.100/bridge/config.php?bridgeid=22');
define('OLDFILE', '/etc/bridge/.config.old');

// rrdsrv on 5001/tcp
define('RRDSRV', "10.10.254.100");

class Cmd {
	function run($args) {
		echo "$args\n";
		exec($args, $tmp);
		return $tmp;
	}

	function ebtables($args) {
		return self::run("/sbin/ebtables {$args}");
	}

	function brctl($args) {
		return self::run("/usr/sbin/brctl {$args}");
	}

	function vconfig($args) {
		return self::run("/sbin/vconfig {$args}");
	}

	function ifconfig($args) {
		return self::run("/sbin/ifconfig {$args}");
	}

	function route($args) {
		return self::run("/sbin/route {$args}");
	}

	function tc($args) {
		return self::run("/sbin/tc {$args}");
	}

	function vtund($args) {
		return self::run("/usr/sbin/vtund {$args}");
	}

	function ip($args) {
		return self::run("/sbin/ip {$args}");
	}
}

class Config {
	function fetch() {
		$data = @file_get_contents(NEWFILE);
		if (empty($data))
			return false;

		$arr = @unserialize($data);
		if (!is_array($arr))
			return false;

		return $arr;
	}

	function getOld() {
		if (!file_exists(OLDFILE))
			return false;

		$data = @file_get_contents(OLDFILE);
		$arr = @unserialize($data);
		if (!is_array($arr))
			return false;

		return $arr;
	}

	function getEmpty() {
		return array(
			'bridge' => array(),
			'tunnel' => array(),
			'vlan' => array(),
			'hlsw' => array(),
			'forward' => array()
			);
	}

	function save($arr) {
		if ($arr == self::getEmpty())
			return;

		if (!$fp = @fopen(OLDFILE, "w")) {
			echo "write error\n";
			return;
		}

		fwrite($fp, @serialize($arr));
		fclose($fp);
	}
}

class BaseTables {
	function init($bridge) {
		// bridge present?
		if (!is_dir("/sys/class/net/br0")) {
			// create bridge
			Cmd::brctl("addbr br0");

		} else {
			// delete all subdevices
			$dir = opendir("/sys/class/net/br0/brif");
			while ($dir !== false && (($file = readdir($dir)) !== false)) {
				if ($file == "." || $file == "..")
					continue;

				Cmd::brctl("delif br0 {$file}");
			}
			closedir($dir);
		}

		// bridge init
		Cmd::brctl("setfd 2");
		Cmd::ifconfig("br0 0.0.0.0 up");

		// delete all rules & chains
		Cmd::ebtables("-t nat -F");
		Cmd::ebtables("-t nat -X");
		Cmd::ebtables("-t filter -F");
		Cmd::ebtables("-t filter -X");

		Cmd::ebtables("-t nat -N loop_pkts");
		Cmd::ebtables("-t nat -A loop_pkts -j DROP");

		// TODO: tap_block wird pakete * interfaces durchlaufen
		Cmd::ebtables("-t filter -N tap_block");
		Cmd::ebtables("-t filter -A tap_block -j RETURN");

		// eigene pakete empfangen -> loop
		Cmd::ebtables("-t nat -A PREROUTING -s {$bridge['macmask']} -j loop_pkts");
	}

	function add_tunnel($tunnels) {
		foreach ($tunnels as $tunnel) {
			// pakete durch tunnel von anderer Bridge -> ok
			// pakete von anderen Bridges auf normalen ports -> loop
			Cmd::ebtables("-t nat -A PREROUTING -i {$tunnel['device']} -j ACCEPT");
			Cmd::ebtables("-t nat -A PREROUTING -s {$tunnel['macmask']} -j loop_pkts");

			// wenns ausm tunnel kommt, nicht in nen tunnel stecken
			Cmd::ebtables("-t filter -A FORWARD -i {$tunnel['device']} -j tap_block");
			Cmd::ebtables("-t filter -I tap_block 1 -o {$tunnel['device']} -j DROP");
		}
		
		// ansonsten alles in den tunnel packen
		foreach ($tunnels as $tunnel)
			Cmd::ebtables("-t filter -A FORWARD -o {$tunnel['device']} -j ACCEPT");
	}
}

class ForwardTables {
	function init() {
		// delete all vlan devices
		$dir = opendir("/sys/class/net/");
		while ($dir !== false && (($file = readdir($dir)) !== false)) {
			if ($file == "." || $file == "..")
				continue;

			if (strncmp($file, "eth", 3))
				continue;

			$part = explode('.', $file);
			if (!isset($part[1]))
				continue;

			$address = Cmd::ip("-4 addr show dev ${file}");
			if (count($address))
				continue;
			
			Cmd::ifconfig("{$file} down");
			Cmd::vconfig("rem {$file}");
		}
		closedir($dir);

		Cmd::ebtables("-t nat -N hlswmaster");
		Cmd::ebtables("-t nat -A hlswmaster -j DROP");

		Cmd::ebtables("-t nat -N arp_pkts");
		Cmd::ebtables("-t nat -A arp_pkts -j DROP");

		Cmd::ebtables("-t nat -N nonip_pkts");
		Cmd::ebtables("-t nat -A nonip_pkts -j DROP");

		Cmd::ebtables("-t nat -N udp_blocked");
		Cmd::ebtables("-t nat -A udp_blocked -j DROP");

		Cmd::ebtables("-t nat -N udp_forwarded");
		Cmd::ebtables("-t nat -A udp_forwarded -j ACCEPT");

		Cmd::ebtables("-t nat -N fwdfilter");
		Cmd::ebtables("-t nat -A fwdfilter -j udp_blocked");

		Cmd::ebtables("-t filter -N hlswmaster");
		Cmd::ebtables("-t filter -A hlswmaster -j DROP");

		// allow hlsw-master-querys from all clients
		// but forward them only to our masters
		Cmd::ebtables("-t nat -A PREROUTING -p ipv4 --ip-proto udp --ip-dport 7140 -j ACCEPT");
		Cmd::ebtables("-t filter -A FORWARD -p ipv4 --ip-proto udp --ip-dport 7140 -j hlswmaster");

		// only allow hlsw-querys from master servers
		Cmd::ebtables("-t nat -A PREROUTING -p ipv4 --ip-proto udp --ip-sport 7130:7139 -j hlswmaster");

		// udp broadcast und multicast filtern
		Cmd::ebtables("-t nat -A PREROUTING -p ipv4 --ip-proto udp --ip-dst 255.255.255.255 -j fwdfilter");
		Cmd::ebtables("-t nat -A PREROUTING -p ipv4 --ip-proto udp --ip-dst 224.0.0.0/8 -j fwdfilter");

		// udp unicast (falsche netmask beim client) blocken
		Cmd::ebtables("-t nat -A PREROUTING -p ipv4 --ip-proto udp -j udp_blocked");

		// andere protos fuer stats auseinandernehmen
		Cmd::ebtables("-t nat -A PREROUTING -p arp -j arp_pkts");
		Cmd::ebtables("-t nat -A PREROUTING -j nonip_pkts");
	}

	private function add_hlsw($hlsw) {
		Cmd::ebtables("-t nat -I hlswmaster 1 -p ipv4 --ip-src {$hlsw['ip']} -j ACCEPT");
		Cmd::ebtables("-t filter -I hlswmaster 1 -o {$hlsw['dev']} -j ACCEPT");
	}

	private function del_hlsw($hlsw) {
		Cmd::ebtables("-t nat -D hlswmaster -p ipv4 --ip-src {$hlsw['ip']} -j ACCEPT");
		Cmd::ebtables("-t filter -D hlswmaster -o {$hlsw['dev']} -j ACCEPT");
	}

	private function add_vlan($vlan) {
		// vlan 0 and vlan 1 are invalid -> use basename (eth1.1 -> eth1)
		$part = explode('.', $vlan['name']);
		if (isset($part[1]) && ($part[1] >= 2)) {
			Cmd::ifconfig("{$part[0]} 0.0.0.0 up");
			Cmd::vconfig("add {$part[0]} {$part[1]}");
		}

		// add device to bridge
		Cmd::ifconfig("{$vlan['name']} 0.0.0.0 up");
		Cmd::brctl("addif br0 {$vlan['name']}");
		// TODO: bei echten devices kann qdisc noch vorhanden sein
		Cmd::tc("qdisc add dev {$vlan['name']} root tbf rate {$vlan['bw']}kbit burst 4k latency 100ms");

		// stats
		Cmd::ebtables("-t nat -I loop_pkts 1 -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -I arp_pkts 1 -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -I nonip_pkts 1 -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -I udp_blocked 1 -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -I udp_forwarded 1 -i {$vlan['name']} -j ACCEPT");

		// ausgehende src-mac anpassen fuer loop detection
		// und damit non-cisco HW funktionieren wuerde :)
		Cmd::ebtables("-t nat -I POSTROUTING 1 -o {$vlan['name']} -j snat --to-source {$vlan['mac']}");
	}

	private function del_vlan($vlan) {
		// remove from bridge
		Cmd::brctl("delif br0 {$vlan['name']}");
		Cmd::ifconfig("{$vlan['name']} down");

		// remove vlan
		$part = explode('.', $vlan['name']);
		if (isset($part[1]) && ($part[1] >= 2))
			Cmd::vconfig("rem {$vlan['name']}");

		// stats
		Cmd::ebtables("-t nat -D loop_pkts -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -D arp_pkts -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -D nonip_pkts -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -D udp_blocked -i {$vlan['name']} -j DROP");
		Cmd::ebtables("-t nat -D udp_forwarded -i {$vlan['name']} -j ACCEPT");

		// snat mac
		Cmd::ebtables("-t nat -D POSTROUTING -o {$vlan['name']} -j snat --to-source {$vlan['mac']}");
	}

	private function add_fwd($fwd) {
		$port = $fwd['portlo'];
		if ($fwd['porthi'] != 0)
			$port .= ':'.$fwd['porthi'];

		$target = ($fwd['active'] ? "udp_forwarded" : "udp_blocked");
		Cmd::ebtables("-t nat -I fwdfilter 1 -p ipv4 --ip-proto udp --ip-dport {$port} -j {$target}");
	}

	private function del_fwd($fwd) {
		$port = $fwd['portlo'];
		if ($fwd['porthi'] != 0)
			$port .= ':'.$fwd['porthi'];

		$target = ($fwd['active'] ? "udp_forwarded" : "udp_blocked");
		Cmd::ebtables("-t nat -D fwdfilter -p ipv4 --ip-proto udp --ip-dport {$port} -j {$target}");
	}

	function checkDiff($old, $new) {
		$oldarr = $old['vlan'];
		$newarr = $new['vlan'];
		foreach ($newarr as $id => $tmp) {
			if (!isset($oldarr[$id])) {
				self::add_vlan($tmp);

			} else if ($tmp !== $oldarr[$id]) {
				// TODO: this is slow
				self::del_vlan($oldarr[$id]);
				self::add_vlan($tmp);
			}
		}
		foreach ($oldarr as $id => $tmp) {
			if (!isset($newarr[$id]))
				self::del_vlan($tmp);
		}

		$oldarr = $old['forward'];
		$newarr = $new['forward'];
		foreach ($newarr as $id => $tmp) {
			if (!isset($oldarr[$id])) {
				self::add_fwd($tmp);

			} else if ($tmp !== $oldarr[$id]) {
				self::del_fwd($oldarr[$id]);
				self::add_fwd($tmp);
			}
		}
		foreach ($oldarr as $id => $tmp) {
			if (!isset($newarr[$id]))
				self::del_fwd($tmp);
		}

		$oldarr = $old['hlsw'];
		$newarr = $new['hlsw'];
		foreach ($newarr as $id => $tmp) {
			if (!isset($oldarr[$id])) {
				self::add_hlsw($tmp);

			} else if ($tmp !== $oldarr[$id]) {
				self::del_hlsw($oldarr[$id]);
				self::add_hlsw($tmp);
			}
		}
		foreach ($oldarr as $id => $tmp) {
			if (!isset($newarr[$id]))
				self::del_hlsw($tmp);
		}
	}
}

class Vtund {
	function getBaseConfig() {
		return "
options {
	type stand;
	port 5000;
	timeout 60;
	syslog daemon;
	ifconfig /sbin/ifconfig;
}

default {
	type ether;
	proto udp;
	timeout 60;
	compress no;
	encrypt no;
	keepalive yes;
	stat no;
	speed 0;
	multi kill;

	up {
		ifconfig \"%d 0.0.0.0 up\";
		program /usr/sbin/brctl \"addif br0 %d\";
	};

	down {
		program /usr/sbin/brctl \"delif br0 %d\";
		ifconfig \"%d down\";
	};
}

";
	}

	function getSession($tunnel) {
		return "
{$tunnel['name']} {
	# partner {$tunnel['dest']}
	# our mode: {$tunnel['mode']}
	device {$tunnel['device']};
	password whiterabbit;
}
";
	}

	function buildConfig($arr) {
		if (!$fp = @fopen("/etc/vtund.conf", "w")) {
			echo "could not write vtund config";
			return;
		}

		// basic config
		fwrite($fp, self::getBaseConfig());

		// add sessions
		foreach ($arr as $tunnel)
			fwrite($fp, self::getSession($tunnel));

		fclose($fp);
	}

	function init($arr) {
		self::buildConfig($arr);

		// check if vtund server runs
		$srv_running = false;
		if (file_exists("/var/run/vtund.pid")) {
			$pid = file_get_contents("/var/run/vtund.pid");

			// send SIGHUP, to reread the config
			$srv_running = posix_kill($pid, 1);
		}

		// start the server
		if (!$srv_running)
			Cmd::vtund("-f /etc/vtund.conf -s");

		// kill all clients (_our_ clients, not server childs!)
		$dir = opendir("/var/run/");
		while ($dir !== false && (($file = readdir($dir)) !== false)) {
			if ($file == "." || $file == "..")
				continue;

			if (strncmp($file, "vtund.tap", 9))
				continue;

			// send SIGTERM to client vtund
			$pid = file_get_contents("/var/run/".$file);
			posix_kill($pid, 15);
		}
		closedir($dir);

		// start all clients
		foreach ($arr as $tunnel) {
			if ($tunnel['mode'] == "client")
				Cmd::vtund("-f /etc/vtund.conf -p {$tunnel['name']} {$tunnel['dest']}");
		}
	}
}

class Stats {
	private $sock;
	private $files = array();

	private function write($msg) {
		socket_write($this->sock, $msg."\r\n", strlen($msg."\r\n"));
	}

	private function read() {
		while (true) {
			$fdset = array($this->sock);
			$sel = socket_select($fdset, $write = NULL, $except = NULL, 0, 100000);
			if ($sel == 0 || $sel === false)
				return false;

			return socket_read($this->sock, 1024, PHP_NORMAL_READ);
		}
	}

	private function waitcmd() {
		$retval = array();
		while (($line = $this->read()) !== false && strlen($line) > 0) {
			if (!strncmp($line, 'OK', 2))
				break;

			if (!strncmp($line, 'ERROR', 2)) {
				echo $line;
				break;
			}
			$retval[] = $line;
		}
		return $retval;
	}

	function connect($id) {
		$this->sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
		socket_connect($this->sock, RRDSRV, 5001);

		self::write('ls');
		$list = self::waitcmd();
		foreach ($list as $num => $name)
			$list[$num] = substr(trim($name), 2, 32);

		$dirname = 'bridge-'.$id;
		if (!in_array($dirname, $list)) {
			self::write('mkdir '. $dirname);
			self::waitcmd();
		}

		self::write('cd '. $dirname);
		self::waitcmd();

		self::write('ls');
		$list = self::waitcmd();
		foreach ($list as $num => $name)
			$list[$num] = substr(trim($name), 2, 32);

		$this->files = $list;
	}

	function get_vlans() {
		$result = array();

		unset($lines);
		$lines = Cmd::ebtables('-t nat -L loop_pkts --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-i') !== false) {
				$parts = explode(' ', $line);
				$result[$parts[1]]['loop'] = $parts[11];
			}
		}

		unset($lines);
		$lines = Cmd::ebtables('-t nat -L arp_pkts --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-i') !== false) {
				$parts = explode(' ', $line);
				$result[$parts[1]]['arp'] = $parts[11];
			}
		}

		unset($lines);
		$lines = Cmd::ebtables('-t nat -L nonip_pkts --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-i') !== false) {
				$parts = explode(' ', $line);
				$result[$parts[1]]['nonip'] = $parts[11];
			}
		}

		unset($lines);
		$lines = Cmd::ebtables('-t nat -L udp_blocked --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-i') !== false) {
				$parts = explode(' ', $line);
				$result[$parts[1]]['blocked'] = $parts[11];
			}
		}

		unset($lines);
		$lines = Cmd::ebtables('-t nat -L udp_forwarded --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-i') !== false) {
				$parts = explode(' ', $line);
				$result[$parts[1]]['forwarded'] = $parts[11];
			}
		}

		unset($lines);
		$lines = Cmd::ebtables('-t nat -L POSTROUTING --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-o') !== false) {
				$parts = explode(' ', $line);
				$result[$parts[1]]['output'] = $parts[14];
			}
		}

		foreach ($result as $name => $data) {
			$fullname = "vlan-$name.rrd";
			if (!in_array($fullname, $this->files)) {
				$cmd = "create $fullname --start now -s 60 ".
					'DS:loop:DERIVE:60:0:10000000 '.
					'DS:arp:DERIVE:60:0:10000000 '.
					'DS:nonip:DERIVE:60:0:10000000 '.
					'DS:block:DERIVE:60:0:10000000 '.
					'DS:fwd:DERIVE:60:0:10000000 '.
					'DS:out:DERIVE:60:0:10000000 '.
					'RRA:AVERAGE:0.5:1:720 RRA:AVERAGE:0.5:5:576 '.
					'RRA:MIN:0.5:1:720 RRA:MIN:0.5:5:576 '.
					'RRA:MAX:0.5:1:720 RRA:MAX:0.5:5:576 ';
				self::write($cmd);
				self::waitcmd();
			}

			$cmd = "update $fullname N:{$data['loop']}:{$data['arp']}:{$data['nonip']}:{$data['blocked']}:{$data['forwarded']}:{$data['output']}";
			self::write($cmd);
			self::waitcmd();
		}
	}

	function get_forwards($forwards) {
		$names = array();
		foreach ($forwards as $id => $fwd) {
			$key = $fwd['portlo'];
			if ($fwd['porthi'] != 0)
				$key .= ':'.$fwd['porthi'];

			$names[$key] = "forward-$id.rrd";
		}

		$result = array();
		$lines = Cmd::ebtables('-t nat -L fwdfilter --Lc');
		foreach ($lines as $line) {
			if (strpos($line, '-p') !== false) {
				$parts = explode(' ', $line);
				if (!isset($names[$parts[5]]))
					continue;

				switch ($parts[7]) {
				case 'udp_forwarded,':
					$result[$names[$parts[5]]] = "N:{$parts[14]}:0";
					break;

				case 'udp_blocked,':
					$result[$names[$parts[5]]] = "N:0:{$parts[14]}";
					break;
				}
			}
		}

		foreach ($result as $fullname => $data) {
			if (!in_array($fullname, $this->files)) {
				$cmd = "create $fullname --start now -s 60 ".
					'DS:fwd:DERIVE:60:0:10000000 '.
					'DS:block:DERIVE:60:0:10000000 '.
					'RRA:AVERAGE:0.5:1:720 RRA:AVERAGE:0.5:5:576 '.
					'RRA:MIN:0.5:1:720 RRA:MIN:0.5:5:576 '.
					'RRA:MAX:0.5:1:720 RRA:MAX:0.5:5:576 ';
				self::write($cmd);
				self::waitcmd();
			}

			self::write("update $fullname $data");
			self::waitcmd();
		}
	}

	function get_masters($masters) {
		$lines_from = Cmd::ebtables('-t nat -L hlswmaster --Lc'); 
		$lines_to = Cmd::ebtables('-t filter -L hlswmaster --Lc');

		$result = array();
		foreach ($masters as $id => $hlsw) {
			foreach ($lines_from as $line) {
				if (strpos($line, $hlsw['ip'])) {
					$parts = explode(' ', $line);
					$from = $parts[14];
					break;
				}
			}

			foreach ($lines_to as $line) {
				if (strpos($line, $hlsw['dev'])) {
					$parts = explode(' ', $line);
					$to = $parts[12];
					break;
				}
			}
			$result['hlsw-'.$id.'.rrd'] = "N:{$from}:{$to}";
		}

		foreach ($result as $fullname => $data) {
			if (!in_array($fullname, $this->files)) {
				$cmd = "create $fullname --start now -s 60 ".
					'DS:from:DERIVE:60:0:10000000 '.
					'DS:to:DERIVE:60:0:10000000 '.
					'RRA:AVERAGE:0.5:1:720 RRA:AVERAGE:0.5:5:576 '.
					'RRA:MIN:0.5:1:720 RRA:MIN:0.5:5:576 '.
					'RRA:MAX:0.5:1:720 RRA:MAX:0.5:5:576 ';
				self::write($cmd);
				self::waitcmd();
			}

			self::write("update $fullname $data");
			self::waitcmd();
		}
	}

	function close() {
		socket_close($this->sock);
	}
}


/* teh main */

$init = (isset($_SERVER['argv'][1]) && $_SERVER['argv'][1] == "init");

// get old config, fallback to the empty config
$oldarr = Config::getOld();
if ($oldarr === false)
	$oldarr = Config::getEmpty();

// get new config, fallback to old config
$newarr = Config::fetch();
if ($newarr === false) {
	echo "Fetch failed!\n";
	$newarr = $oldarr;
}

// main config changed -> reset everything
if ($oldarr['bridge'] != $newarr['bridge'])
	$init = true;

// tunnel config changed -> reset everything
if ($oldarr['tunnel'] != $newarr['tunnel'])
	$init = true;

if ($init) {
	// basic bridge layout, loop detection
	BaseTables::init($newarr['bridge']);

	// add bridge rules for tunnels
	BaseTables::add_tunnel($newarr['tunnel']);

	// vlan + port stuff
	ForwardTables::init();

	// setup tunnels
	Vtund::init($newarr['tunnel']);

	// we do a init, so diff between $empty -> $new
	$oldarr = Config::getEmpty();
}

// add VLANs, Forward-Ports and HLSW Master Server
ForwardTables::checkDiff($oldarr, $newarr);

// gather stats and send them to rrdtool server via tcp
$stats = new Stats();
$stats->connect($newarr['bridge']['id']);
$stats->get_vlans();
$stats->get_forwards($newarr['forward']);
$stats->get_masters($newarr['hlsw']);
$stats->close();

// save the config
Config::save($newarr);

?>