<?

ob_start("ob_gzhandler");

require_once("include/bittorrent.php");
require_once("include/benc.php");



function err($msg)
{
	benc_resp(array("failure reason" => array(type => "string", value => $msg)));
	exit();
}

function benc_resp($d)
{
	benc_resp_raw(benc(array(type => "dictionary", value => $d)));
}

function benc_resp_raw($x)
{
	header("Content-Type: text/plain");
	header("Pragma: no-cache");
	print($x);
}

$req = "info_hash:peer_id:!ip:port:uploaded:downloaded:left:!event:!passkey";
foreach (explode(":", $req) as $x)
{
	if ($x[0] == "!")
	{
		$x = substr($x, 1);
		$opt = 1;
	}
	else
		$opt = 0;
	if (!isset($_GET[$x]))
	{
		if (!$opt)
			err("missing key");
		continue;
	}
	$GLOBALS[$x] = unesc($_GET[$x]);
}

if (ENA_PASSKEY && (
		strlen($passkey) != 32 && 
		@mysql_num_rows(@mysql_query("SELECT id FROM users WHERE passkey=" . sqlesc($passkey))) != 1))
	err("Invalid passkey! Re-download the .torrent from $BASEURL ($passkey)");
$passkey=sqlesc($passkey);	

foreach (array("info_hash","peer_id") as $x)
{
	if (strlen($GLOBALS[$x]) != 20)
		err("invalid $x (" . strlen($GLOBALS[$x]) . " - " . urlencode($GLOBALS[$x]) . ")");
}

//if (empty($ip) || !preg_match('/^(\d{1,3}\.){3}\d{1,3}$/s', $ip))
	$ip = getip();

$port = 0 + $port;
$downloaded = 0 + $downloaded;
$uploaded = 0 + $uploaded;
$left = 0 + $left;

$rsize = 50;
foreach(array("num want", "numwant", "num_want") as $k)
{
	if (isset($_GET[$k]))
	{
		$rsize = 0 + $_GET[$k];
		break;
	}
}

$agent = $_SERVER["HTTP_USER_AGENT"];

// Deny access made with a browser...
//if (ereg("^Mozilla\\/", $agent) || ereg("^Opera\\/", $agent) || ereg("^Links ", $agent) || ereg("^Lynx\\/", $agent))
//	err("torrent not registered with this tracker");

if (!$port || $port > 0xffff)
	err("invalid port");

if (!isset($event))
	$event = "";

$seeder = ($left == 0) ? "yes" : "no";




$res = mysql_query("SELECT id, banned, seeders + leechers AS numpeers, UNIX_TIMESTAMP(added) AS ts FROM torrents WHERE " . hash_where("info_hash", $info_hash));

$torrent = mysql_fetch_assoc($res);
if (!$torrent)
	err("torrent not registered with this tracker");

$torrentid = $torrent["id"];

$fields = "seeder, peer_id, ip, port, uploaded, downloaded, userid";

$numpeers = $torrent["numpeers"];
$limit = "";
if ($numpeers > $rsize)
	$limit = "ORDER BY RAND() LIMIT $rsize";
$res = mysql_query("SELECT $fields FROM peers WHERE torrent = $torrentid AND connectable = 'yes' $limit");

$resp = 'd' . benc_str('interval') . 'i' . $announce_interval . 'e' . benc_str('peers') . (($compact = ($_GET['compact'] == 1))?'':'l');
unset($self);
while ($row = mysql_fetch_assoc($res))
{
	$row["peer_id"] = hash_pad($row["peer_id"]);

	if ($row["peer_id"] === $peer_id)
	{
		$userid = $row["userid"];
		$self = $row;
		continue;
	}
	if($compact)
	{
		$peer_ip = explode('.', $row["ip"]);
		$plist .= pack("C*", $peer_ip[0], $peer_ip[1], $peer_ip[2], $peer_ip[3]). pack("n*", (int)$row["port"]);
	} else {
		$resp .= "d" .
		benc_str("ip") . benc_str($row["ip"]) .
		benc_str("peer id") . benc_str($row["peer_id"]) .
		benc_str("port") . "i" . $row["port"] . "e" .
		"e";
	}
}

$resp .= ($compact ? benc_str($plist):''). "ee";

$selfwhere = "torrent = $torrentid AND ". (ENA_PASSKEY ?"passkey=$passkey AND ":'') . hash_where("peer_id", $peer_id);

if (!isset($self))
{
	$res = mysql_query("SELECT $fields FROM peers WHERE $selfwhere");
	$row = mysql_fetch_assoc($res);
	if ($row)
	{
		$userid = $row["userid"];
		$self = $row;
	}
}

//// Up/down stats ////////////////////////////////////////////////////////////

if (!isset($self))
{
	if(ENA_PASSKEY && ENA_PASSKEYLIMITCONNECTIONS)
	{
		$valid = @mysql_num_rows(@mysql_query("SELECT id FROM peers WHERE torrent=$torrentid AND passkey=$passkey"));
		if ($valid[0] >= 1 && $seeder == 'no') 
			err("Connection limit exceeded! You may only leech from one location at a time.");
		if ($valid[0] >= 3 && $seeder == 'yes') 
			err("Connection limit exceeded!");
	}
	$rz = mysql_query("SELECT id, uploaded, downloaded, class FROM users WHERE ip='$ip' AND enabled = 'yes' ". (ENA_PASSKEY ? "AND passkey=$passkey ":''). "ORDER BY last_access DESC LIMIT 1") or err("Tracker error 2");
	if ($MEMBERSONLY && mysql_num_rows($rz) == 0)
		err("Unrecognized host ($ip). Please go to $BASEURL to sign-up or login.");
	$az = mysql_fetch_assoc($rz);
	$userid = $az["id"];

//	if ($left > 0 && $az["class"] < UC_VIP)
	if ($az["class"] < UC_VIP)
	{
		$gigs = $az["uploaded"] / (1024*1024*1024);
		$elapsed = floor((gmtime() - $torrent["ts"]) / 3600);
		$ratio = (($az["downloaded"] > 0) ? ($az["uploaded"] / $az["downloaded"]) : 1);
		if ($ratio < 0.5 || $gigs < 5) $wait = 48;
		elseif ($ratio < 0.65 || $gigs < 6.5) $wait = 24;
		elseif ($ratio < 0.8 || $gigs < 8) $wait = 12;
		elseif ($ratio < 0.95 || $gigs < 9.5) $wait = 6;
		else $wait = 0;
		if (($elapsed < $wait)&&($seeder == 'no'))
				err("Not authorized (" . ($wait - $elapsed) . "h) - READ THE FAQ!");
	}
}
else
{
	$upthis = max(0, $uploaded - $self["uploaded"]);
	$downthis = max(0, $downloaded - $self["downloaded"]);

	if ($upthis > 0 || $downthis > 0)
		mysql_query("UPDATE users SET uploaded = uploaded + $upthis, downloaded = downloaded + $downthis WHERE id=$userid") or err("Tracker error 3");
}

///////////////////////////////////////////////////////////////////////////////

function portblacklisted($port)
{
	// direct connect
	if ($port >= 411 && $port <= 413) return true;

	// bittorrent
	if ($port >= 6881 && $port <= 6889) return true;

	// kazaa
	if ($port == 1214) return true;

	// gnutella
	if ($port >= 6346 && $port <= 6347) return true;

	// emule
	if ($port == 4662) return true;

	// winmx
	if ($port == 6699) return true;

	return false;
}

$updateset = array();

if ($event == "stopped")
{
	if (isset($self))
	{
		mysql_query("DELETE FROM peers WHERE $selfwhere");
		if (mysql_affected_rows())
		{
			if ($self["seeder"] == "yes")
				$updateset[] = "seeders = seeders - 1";
			else
				$updateset[] = "leechers = leechers - 1";
		}
	}
}
else
{
	if ($event == "completed")
		$updateset[] = "times_completed = times_completed + 1";

	if (isset($self))
	{
		mysql_query("UPDATE peers SET uploaded = $uploaded, downloaded = $downloaded, to_go = $left, last_action = NOW(), seeder = '$seeder'"
			. ($seeder == "yes" && $self["seeder"] != $seeder ? ", finishedat = " . time() : "") . " WHERE $selfwhere");
		if (mysql_affected_rows() && $self["seeder"] != $seeder)
		{
			if ($seeder == "yes")
			{
				$updateset[] = "seeders = seeders + 1";
				$updateset[] = "leechers = leechers - 1";
			}
			else
			{
				$updateset[] = "seeders = seeders - 1";
				$updateset[] = "leechers = leechers + 1";
			}
		}
	}
	else
	{
		if (portblacklisted($port))
			err("Port $port is blacklisted.");
		else
		{
			$sockres = @fsockopen($ip, $port, $errno, $errstr, 5);
			if (!$sockres)
				$connectable = "no";
			else
			{
				$connectable = "yes";
				@fclose($sockres);
			}
		}

		$ret = mysql_query("INSERT INTO peers (connectable, torrent, peer_id, ip, port, uploaded, downloaded, to_go, started, last_action, seeder, userid, agent, uploadoffset, downloadoffset, passkey) VALUES ('$connectable', $torrentid, " . sqlesc($peer_id) . ", " . sqlesc($ip) . ", $port, $uploaded, $downloaded, $left, NOW(), NOW(), '$seeder', $userid, " . sqlesc($agent) . ", $uploaded, $downloaded, $passkey)");
		if ($ret)
		{
			if ($seeder == "yes")
				$updateset[] = "seeders = seeders + 1";
			else
				$updateset[] = "leechers = leechers + 1";
		}
	}
}

if ($seeder == "yes")
{
	if ($torrent["banned"] != "yes")
		$updateset[] = "visible = 'yes'";
	$updateset[] = "last_action = NOW()";
}

if (count($updateset))
	mysql_query("UPDATE torrents SET " . join(",", $updateset) . " WHERE id = $torrentid");

benc_resp_raw($resp);


?>