Developer
<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\HttpKernel\HttpCache;
use Symfony\Component\HttpFoundation\IpUtils;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\HttpKernelInterface;
/**
* @author Nicolas Grekas <p@tchwork.com>
*
* @internal
*/
class SubRequestHandler
{
public static function handle(HttpKernelInterface $kernel, Request $request, int $type, bool $catch): Response
{
// save global state related to trusted headers and proxies
$trustedProxies = Request::getTrustedProxies();
$trustedHeaderSet = Request::getTrustedHeaderSet();
// remove untrusted values
$remoteAddr = $request->server->get('REMOTE_ADDR');
if (!$remoteAddr || !IpUtils::checkIp($remoteAddr, $trustedProxies)) {
$trustedHeaders = [
'FORWARDED' => $trustedHeaderSet & Request::HEADER_FORWARDED,
'X_FORWARDED_FOR' => $trustedHeaderSet & Request::HEADER_X_FORWARDED_FOR,
'X_FORWARDED_HOST' => $trustedHeaderSet & Request::HEADER_X_FORWARDED_HOST,
'X_FORWARDED_PROTO' => $trustedHeaderSet & Request::HEADER_X_FORWARDED_PROTO,
'X_FORWARDED_PORT' => $trustedHeaderSet & Request::HEADER_X_FORWARDED_PORT,
'X_FORWARDED_PREFIX' => $trustedHeaderSet & Request::HEADER_X_FORWARDED_PREFIX,
];
foreach (array_filter($trustedHeaders) as $name => $key) {
$request->headers->remove($name);
$request->server->remove('HTTP_'.$name);
}
}
// compute trusted values, taking any trusted proxies into account
$trustedIps = [];
$trustedValues = [];
foreach (array_reverse($request->getClientIps()) as $ip) {
$trustedIps[] = $ip;
$trustedValues[] = sprintf('for="%s"', $ip);
}
if ($ip !== $remoteAddr) {
$trustedIps[] = $remoteAddr;
$trustedValues[] = sprintf('for="%s"', $remoteAddr);
}
// set trusted values, reusing as much as possible the global trusted settings
if (Request::HEADER_FORWARDED & $trustedHeaderSet) {
$trustedValues[0] .= sprintf(';host="%s";proto=%s', $request->getHttpHost(), $request->getScheme());
$request->headers->set('Forwarded', $v = implode(', ', $trustedValues));
$request->server->set('HTTP_FORWARDED', $v);
}
if (Request::HEADER_X_FORWARDED_FOR & $trustedHeaderSet) {
$request->headers->set('X-Forwarded-For', $v = implode(', ', $trustedIps));
$request->server->set('HTTP_X_FORWARDED_FOR', $v);
} elseif (!(Request::HEADER_FORWARDED & $trustedHeaderSet)) {
Request::setTrustedProxies($trustedProxies, $trustedHeaderSet | Request::HEADER_X_FORWARDED_FOR);
$request->headers->set('X-Forwarded-For', $v = implode(', ', $trustedIps));
$request->server->set('HTTP_X_FORWARDED_FOR', $v);
}
// fix the client IP address by setting it to 127.0.0.1,
// which is the core responsibility of this method
$request->server->set('REMOTE_ADDR', '127.0.0.1');
// ensure 127.0.0.1 is set as trusted proxy
if (!IpUtils::checkIp('127.0.0.1', $trustedProxies)) {
Request::setTrustedProxies(array_merge($trustedProxies, ['127.0.0.1']), Request::getTrustedHeaderSet());
}
try {
return $kernel->handle($request, $type, $catch);
} finally {
// restore global state
Request::setTrustedProxies($trustedProxies, $trustedHeaderSet);
}
}
}
Developer
To ensure a smooth integration process and optimal performance, follow these best practices: