OpenSwoole: Streamed response adds invalid "Transfer-Encoding: chunked" header

[Radiergummi]

• Octane Version: 1.3.0 (current, see repro)
• Laravel Version: 9.26.1 (current, see repro)
• PHP Version: 8.1.2
• Server & Version: Swoole / RoadRunner 4.10.0
• Database Driver & Version: -

Description:

When using Octane with the swoole integration, streaming downloads from the filesystem don't work with certain software because an illegal header combination is added to the response; as per RFC 2616, Section 4.4, the Content-Length and Transfer-Encoding headers may not be used together:

"Messages MUST NOT include both a Content-Length header field and a non-identity transfer-coding. If the message does include a non-identity transfer-coding, the Content-Length MUST be ignored."

The following code sample demonstrates the issue:

Route::get('/download', static function (FilesystemManager $filesystem) {
    return $filesystem->disk('local')->download(
        'public/test.jpg',
        'test-download.jpg',
        ['Content-Type' => 'image/jpeg']
    );
});

This yields the following response:

HTTP/1.1 200 OK
Cache-Control: no-cache, private
Connection: keep-alive
Content-Disposition: attachment; filename=test-download.jpg
Content-Length: 515879
Content-Type: image/jpeg
Date: Mon, 29 Aug 2022 15:04:05 GMT
Server: OpenSwoole 4.10.0
Set-Cookie: XSRF-TOKEN=(token here); expires=Mon, 29-Aug-2022 17:04:05 GMT; path=/; samesite=lax
Set-Cookie: laravel_session=(session key here); expires=Mon, 29-Aug-2022 17:04:05 GMT; path=/; httponly; samesite=lax
Transfer-Encoding: chunked

(binary content here)

As you can see, there's a Content-Length, and a Transfer-Encoding: chunked header in the response. This causes nginx to throw up, for example (log entry from production):

f1nih 2022/08/29 09:17:39 [error] 32#32: *78 upstream sent "Content-Length" and "Transfer-Encoding"
headers at the same time while reading response header from upstream

The issue does not occur with the RoadRunner server enabled. Also, this might be related to #109.

Steps To Reproduce:

See the reproduction repository:
matchory/laravel-octane-bug-report-transfer-encoding

0. Install dependencies using composer install
1. Start the server using php artisan octane:start
2. Perform a GET request on the /download endpoint, for example using cURL:

   curl -IX GET http://localhost:8000/download

3. Observe the response headers

[Radiergummi]

As a temporary fix, I removed the Content-Length header by setting it to null:

Route::get('/download', static function (FilesystemManager $filesystem) {
    return $filesystem->disk('local')->download(
        'public/test.jpg',
        'test-download.jpg',
-        ['Content-Type' => 'image/jpeg']
+        ['Content-Type' => 'image/jpeg', 'Content-Length' => null]
    );
});

This precludes Laravel from setting its own Content-Length header, so the response won't contain any, and nginx doesn't complain. This makes it impossible to have download progress on client browsers, however, so this is merely a temporary workaround.

[nunomaduro]

Taking a look at this next week.

[nunomaduro]

Sorry, but the fact that this issue only exists on Swoole, and not on RoadRunner / Regular Nginx, tells me that this is an issue with Swoole itself. Please reach out to the authors library here: https://github.com/swoole/swoole-src/issues.

[Radiergummi]

@nunomaduro understandable. Might you have any pointers for me which OpenSwoole APIs Laravel uses? I'm a bit into the code, but not that deep.

[ignacioalles]

The same situation occurs with swoole (tested with 4.8.10 and 5.0.0), octane 1.3 and it also occurs with not streamed responses with explicit Content-Length like

return response('Hello', 200, [ 'Content-Length' => 5  ]);

[ignacioalles]

It seems to be a bad behaviour of Swoole\Http\Response::write(string $content) method, since end(string $content) method works as expected.

The following test sample using write() method to send content:

$http->on('Request', function (Request $request, Response $response) {
    $response->header('Content-Length', 5);
    $response->write('Hello');
    $response->end();
});

produces:

HTTP/1.1 200 OK
Content-Length: 5
Server: swoole-http-server
Connection: keep-alive
Content-Type: text/html
Date: Wed, 21 Sep 2022 15:47:19 GMT
Transfer-Encoding: chunked

Hello

while sending content in end() like:

$http->on('Request', function (Request $request, Response $response) {
    $response->header('Content-Length', 5);
    $response->end('Hello');
});

does not include Transfer-Encoding header:

HTTP/1.1 200 OK
Content-Length: 5
Server: swoole-http-server
Connection: keep-alive
Content-Type: text/html
Date: Wed, 21 Sep 2022 15:49:46 GMT

Hello