reactphp-tcp-proxy.php

<?php declare(strict_types=1);

use React\EventLoop\Factory;
use React\EventLoop\LoopInterface;
use React\Socket\ConnectionInterface;
use React\Socket\Connector;
use React\Socket\Server;
use React\Stream\Util;

require 'vendor/autoload.php';

function createProxy(LoopInterface $loop, Connector $connector, int $port, string $to): Server
{
    $uri = 'tcp://0.0.0.0:' . $port;
    echo 'Listening on: ', $uri, PHP_EOL;
    $proxy = new Server($uri, $loop);
    $proxy->on('connection', function (ConnectionInterface $connection) use ($loop, $to, $connector) {
        $connection->pause();
        $uri = 'tcp://' . $to;
        echo 'Opening connection to: ', $uri, PHP_EOL;
        $connector->connect($uri)->then(function (ConnectionInterface $service) use ($connection) {
            echo 'Connected!', PHP_EOL;
            Util::pipe($connection, $service, ['end' => true]);
            Util::pipe($service, $connection, ['end' => true]);
            $connection->resume();
        }, function (Throwable $throwable) {
            echo $throwable, PHP_EOL;
        });
    });

    return $proxy;
}

$loop = Factory::create();
$connector = new Connector($loop);

$proxies = [];
$signalHandler = function () use (&$signalHandler, &$proxies, $loop) {
    $loop->removeSignal(SIGINT, $signalHandler);
    $loop->removeSignal(SIGTERM, $signalHandler);
    foreach ($proxies as $proxy) {
        $proxy->close();
    }
};
$loop->addSignal(SIGINT, $signalHandler);
$loop->addSignal(SIGTERM, $signalHandler);

foreach (file('/etc/proxy/routes') as $route) {
    [$port, $to] = explode('=>', $route);
    $proxies[] = createProxy($loop, $connector, (int)$port, $to);
}

$loop->run();