/**
* 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}.");
}
/**
* Save announce for all the torrents in the database so clients know where to connect.
*
* This method runs in infinite loop repeating announcing every self::ANNOUNCE_INTERVAL seconds.
*/
protected function announce()
{
$persistence = $this->config->get('persistence');
$iterations = 0;
do {
$all_torrents = $persistence->getAllInfoHash();
foreach ($all_torrents as $torrent_info) {
$persistence->saveAnnounce($torrent_info['info_hash'], $this->peer->peer_id, $this->peer->external_address, $this->peer->port, $torrent_info['length'], 0, 0, 'complete', self::ANNOUNCE_INTERVAL);
}
$this->logger->logMessage('Seeder server announced itself for ' . count($all_torrents) . " torrents at address {$this->peer->external_address}:{$this->peer->port} (announces every " . self::ANNOUNCE_INTERVAL . 's).');
sleep(self::ANNOUNCE_INTERVAL);
} while (++$iterations < self::STOP_AFTER_ITERATIONS);
// Memory leak prevention, see self::STOP_AFTER_ITERATIONS.
$this->logger->logMessage('Announce process restarts to prevent memory leaks.');
exit(0);
}
