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Executor.php
108 lines (85 loc) · 3.13 KB
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Executor.php
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<?php
namespace React\Dns\Query;
use React\Dns\BadServerException;
use React\Dns\Model\Message;
use React\Dns\Protocol\Parser;
use React\Dns\Protocol\BinaryDumper;
use React\EventLoop\LoopInterface;
use React\Promise\Deferred;
use React\Socket\Connection;
class Executor implements ExecutorInterface
{
private $loop;
private $parser;
private $dumper;
private $timeout;
public function __construct(LoopInterface $loop, Parser $parser, BinaryDumper $dumper, $timeout = 5)
{
$this->loop = $loop;
$this->parser = $parser;
$this->dumper = $dumper;
$this->timeout = $timeout;
}
public function query($nameserver, Query $query)
{
$request = $this->prepareRequest($query);
$queryData = $this->dumper->toBinary($request);
$transport = strlen($queryData) > 512 ? 'tcp' : 'udp';
return $this->doQuery($nameserver, $transport, $queryData, $query->name);
}
public function prepareRequest(Query $query)
{
$request = new Message();
$request->header->set('id', $this->generateId());
$request->header->set('rd', 1);
$request->questions[] = (array) $query;
$request->prepare();
return $request;
}
public function doQuery($nameserver, $transport, $queryData, $name)
{
$parser = $this->parser;
$loop = $this->loop;
$response = new Message();
$deferred = new Deferred();
$retryWithTcp = function () use ($nameserver, $queryData, $name) {
return $this->doQuery($nameserver, 'tcp', $queryData, $name);
};
$timer = $this->loop->addTimer($this->timeout, function () use (&$conn, $name, $deferred) {
$conn->close();
$deferred->reject(new TimeoutException(sprintf("DNS query for %s timed out", $name)));
});
$conn = $this->createConnection($nameserver, $transport);
$conn->on('data', function ($data) use ($retryWithTcp, $conn, $parser, $response, $transport, $deferred, $timer) {
$responseReady = $parser->parseChunk($data, $response);
if (!$responseReady) {
return;
}
$timer->cancel();
if ($response->header->isTruncated()) {
if ('tcp' === $transport) {
$deferred->reject(new BadServerException('The server set the truncated bit although we issued a TCP request'));
} else {
$conn->end();
$deferred->resolve($retryWithTcp());
}
return;
}
$conn->end();
$deferred->resolve($response);
});
$conn->write($queryData);
return $deferred->promise();
}
protected function generateId()
{
return mt_rand(0, 0xffff);
}
protected function createConnection($nameserver, $transport)
{
$fd = stream_socket_client("$transport://$nameserver", $errno, $errstr, 0, STREAM_CLIENT_CONNECT | STREAM_CLIENT_ASYNC_CONNECT);
stream_set_blocking($fd, 0);
$conn = new Connection($fd, $this->loop);
return $conn;
}
}