/**
* Manages handshaking with the client.
*
* If seeders_stop_seeding config key is set to a number greater than 0,
* we check if we have at least N seeders beyond ourselves for the requested
* torrent and if so, stop seeding (to spare bandwith).
*
* @throws PHPTracker_Seeder_Error_CloseConnection In case when the reqeust is invalid or we don't want or cannot serve the requested torrent.
* @param PHPTracker_Seeder_Client $client
*/
protected function shakeHand(PHPTracker_Seeder_Client $client)
{
$protocol_length = unpack('C', $client->socketRead(1));
$protocol_length = current($protocol_length);
if (($protocol = $client->socketRead($protocol_length)) !== self::PROTOCOL_STRING) {
$this->logger->logError("Client tries to connect with unsupported protocol: " . substr($protocol, 0, 100) . ". Closing connection.");
throw new PHPTracker_Seeder_Error_CloseConnection('Unsupported protocol.');
}
// 8 reserved void bytes.
$client->socketRead(8);
$info_hash = $client->socketRead(20);
$client->peer_id = $client->socketRead(20);
$info_hash_readable = unpack('H*', $info_hash);
$info_hash_readable = reset($info_hash_readable);
$torrent = $this->persistence->getTorrent($info_hash);
if (!isset($torrent)) {
throw new PHPTracker_Seeder_Error_CloseConnection('Unknown info hash.');
}
$client->torrent = $torrent;
// If we have X other seeders already, we stop seeding on our own.
if (0 < ($seeders_stop_seeding = $this->config->get('seeders_stop_seeding', false, 0))) {
$stats = $this->persistence->getPeerStats($info_hash, $this->peer_id);
if ($stats['complete'] >= $seeders_stop_seeding) {
$this->logger->logMessage("External seeder limit ({$seeders_stop_seeding}) reached for info hash {$info_hash_readable}, stopping seeding.");
throw new PHPTracker_Seeder_Error_CloseConnection('Stop seeding, we have others to seed.');
}
}
// Our handshake signal.
$client->socketWrite(pack('C', strlen(self::PROTOCOL_STRING)) . self::PROTOCOL_STRING . pack('a8', '') . $info_hash . pack('a20', $this->peer_id));
$this->logger->logMessage("Handshake completed with peer {$client->peer_id} with address {$client->address}:{$client->port}, info hash: {$info_hash_readable}.");
}
/**
* Announce a peer to be tracked and return message to the client.
*
* This methods needs 'interval' key to be set in the config of the class
* (not i the GET!). This is a number representing seconds for the client to
* wait for the next announcement.
*
* Optional config key 'load_balancing' (ON by defailt) adds 10% dispersion
* to the interval value to avoid possible announce peeks.
*
* @param PHPTracker_Config_Interface $get Config-like representation of the CGI parameters (aka. GET) sent.
* @return string
*/
public function announce(PHPTracker_Config_Interface $get)
{
try {
try {
list($info_hash, $peer_id, $port, $uploaded, $downloaded, $left) = $get->getMulti(array('info_hash', 'peer_id', 'port', 'uploaded', 'downloaded', 'left'), true);
} catch (PHPTracker_Config_Error_Missing $e) {
return $this->announceFailure("Invalid get parameters; " . $e->getMessage());
}
// IP address might be set explicitly in the GET.
$ip = $get->get('ip', false, $this->config->get('ip'));
$event = $get->get('event', false, '');
if (20 != strlen($info_hash)) {
return $this->announceFailure("Invalid length of info_hash.");
}
if (20 != strlen($peer_id)) {
return $this->announceFailure("Invalid length of info_hash.");
}
if (!(is_numeric($port) && is_int($port = $port + 0) && 0 <= $port)) {
return $this->announceFailure("Invalid port value.");
}
if (!(is_numeric($uploaded) && is_int($uploaded = $uploaded + 0) && 0 <= $uploaded)) {
return $this->announceFailure("Invalid uploaded value.");
}
if (!(is_numeric($downloaded) && is_int($downloaded = $downloaded + 0) && 0 <= $downloaded)) {
return $this->announceFailure("Invalid downloaded value.");
}
if (!(is_numeric($left) && is_int($left = $left + 0) && 0 <= $left)) {
return $this->announceFailure("Invalid left value.");
}
$interval = intval($this->config->get('interval'));
$this->persistence->saveAnnounce($info_hash, $peer_id, $ip, $port, $downloaded, $uploaded, $left, 'completed' == $event ? 'complete' : null, 'stopped' == $event ? 0 : $interval * 2);
$peers = $this->persistence->getPeers($info_hash, $peer_id, $get->get('compact', false, false), $get->get('no_peer_id', false, false));
$peer_stats = $this->persistence->getPeerStats($info_hash, $peer_id);
if (true === $this->config->get('load_balancing', false, true)) {
// Load balancing for tracker announcements.
$interval = $interval + mt_rand(round($interval / -10), round($interval / 10));
}
$announce_response = array('interval' => $interval, 'complete' => intval($peer_stats['complete']), 'incomplete' => intval($peer_stats['incomplete']), 'peers' => $peers);
return PHPTracker_Bencode_Builder::build($announce_response);
} catch (Exception $e) {
trigger_error('Failure while announcing: ' . $e->getMessage(), E_USER_WARNING);
return $this->announceFailure("Failed to announce because of internal server error.");
}
}
