ValidateRequestContentSize.php

<?php

declare (strict_types = 1);

namespace App\EventListener;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpFoundation\Response;

final class ValidateRequestContentSize implements EventSubscriberInterface
{
    private $maxContentLength;

    public function __construct(string $max = null)
    {
        $this->maxContentLength = $this->normalizeMaxSize($max ?? ini_get('post_max_size'));
    }

    public function onKernelRequest(GetResponseEvent $event): void
    {
        $request = $event->getRequest();
        $contentLength = $request->headers->get('content-length');

        if ($this->maxContentLength && $contentLength > $this->maxContentLength) {
            $event->setResponse(new Response('', Response::HTTP_REQUEST_ENTITY_TOO_LARGE));
        }
    }

    private function normalizeMaxSize(string $size): ?int
    {
        if ('' === $size) {
            return null;
        }

        $max = ltrim(strtolower(trim($size)), '+');
        if (0 === strpos($max, '0x')) {
            $max = intval($max, 16);
        } elseif (0 === strpos($max, '0')) {
            $max = intval($max, 8);
        } else {
            $max = (int) $max;
        }

        switch (substr($size, -1)) {
            case 't': $max *= 1024;
            // no break
            case 'g': $max *= 1024;
            // no break
            case 'm': $max *= 1024;
            // no break
            case 'k': $max *= 1024;
        }

        return $max;
    }

    public static function getSubscribedEvents()
    {
        return [
            KernelEvents::REQUEST => 'onKernelRequest',
        ];
    }
}