/**
* Manages handshaking with the client.
*
* If seeders_stop_seeding 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 bandwidth).
*
* @param Client $client Client
*
* @throws Error\CloseConnection In case when the request is invalid
* or we don't want or cannot serve
* the requested torrent.
* @return void
*/
protected function shakeHand(Client $client)
{
$protocol_length = unpack('C', $client->socketRead(1));
$protocol_length = current($protocol_length);
$protocol = $client->socketRead($protocol_length);
if ($protocol !== self::PROTOCOL_STRING) {
$this->logger->logError("Client tries to connect with unsupported protocol: " . substr($protocol, 0, 100) . ". Closing connection.");
throw new Error\CloseConnection('Unsupported protocol.');
}
// 8 reserved void bytes.
$client->socketRead(8);
$info_hash = $client->socketRead(20);
$client->setPeerId($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 Error\CloseConnection('Unknown info hash.');
}
$client->setTorrent($torrent);
// If we have X other seeders already, we stop seeding on our own.
if (0 < ($seeders_stop_seeding = $this->seeders_stop_seeding)) {
$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 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->getPeerId()} " . "with address {$client->getAddress()}:{$client->getPort()}, " . "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.
*
* @return void
*/
protected function announce()
{
$persistence = $this->persistence;
$iterations = 0;
do {
$all_torrents = $persistence->getAllInfoHash();
foreach ($all_torrents as $torrent_info) {
$persistence->saveAnnounce($torrent_info['info_hash'], $this->peer->getPeerId(), $this->peer->getExternalAddress(), $this->peer->getPort(), $torrent_info['length'], 0, 0, 'complete', self::ANNOUNCE_INTERVAL);
}
$this->logger->logMessage('Seeder server announced itself for ' . count($all_torrents) . " torrents at address {$this->peer->getExternalAddress()}:" . "{$this->peer->getPort()} (announces every " . self::ANNOUNCE_INTERVAL . 's).');
sleep(self::ANNOUNCE_INTERVAL);
// Memory leak prevention, see self::STOP_AFTER_ITERATIONS.
} while (++$iterations < self::STOP_AFTER_ITERATIONS);
$this->logger->logMessage('Announce process restarts to prevent memory leaks.');
exit(0);
}
