How to pass $_SESSION variables to a websocket server?
Question
I have searched a lot on the web but didn't find a useful clue.
I have a websocket server and a web server running together on my local machine.
I need to pass $_SESSION data to the websocket server when a client connects to it using the browser API 'new WebSocket("ws://localhost")' (the request is send to the websocket using a reverse proxy, which knows it when receives requests with an 'Upgrade' header).
The point is that the clients successfully connect to the ws server, but I need to recover also their SESSION data using the $_SESSION variables setted by the HTTP web server.
Actually my situation is this (I am using the Ratchet library):
use Ratchet\Server\IoServer;
use Ratchet\Http\HttpServer;
use Ratchet\WebSocket\WsServer;
use MyApp\MyAppClassChat;
require dirname(__DIR__) . '/vendor/autoload.php';
$server = IoServer::factory(new HttpServer(new WsServer(new MyAppClass())), 8080);
$server->run();
The MyAppClass is very simple:
<?php
namespace MyAppClass;
use Ratchet\MessageComponentInterface;
use Ratchet\ConnectionInterface;
class MyAppClass implements MessageComponentInterface {
protected $clients;
public function __construct() {
$this->clients = new \SplObjectStorage;
}
public function onOpen(ConnectionInterface $conn) {
/* I would like to put recover the session infos of the clients here
but the session_start() call returns an empty array ($_SESSION variables have been previuosly set by the web server)*/
session_start();
var_dump($_SESSION) // empty array...
echo "New connection! ({$conn->resourceId})\n";
}
public function onMessage(ConnectionInterface $from, $msg) {
$numberOfReceivers = count($this->clients) -1;
echo sprintf('Connection %d sending message "%s" to %d other connection%s' . "\n", $from->resourceId, $msg,
$numberOfReceivers, $numberOfReceivers == 1 ? '' : 's');
$this->clients->rewind();
while ($this->clients->valid())
{
$client = $this->clients->current();
if ($client !== $from) {
$client->send($msg);
}
$this->clients->next();
}
}
public function onClose(ConnectionInterface $conn) {
$this->clients->detach($conn);
echo "Connection {$conn->resourceId} has disconnected\n";
}
public function onError(ConnectionInterface $conn, \Exception $e) {
echo "An error has occurred: {$e->getMessage()}\n";
$conn->close();
}
}
Is there a way to do that with my actual layout or should I configure apache in order to use mod_proxy_wstunnel module?
Thanks for help!!!
3 answers
solution1
14 ACCPTED 2014-09-02 01:30:26
As other StackOverflow answers show ( Ratchet without Symfony session , Starting a session within a ratchet websocket connection ), there is no way to directly share the $_SESSION variable between Apache and the Ratchet process. It is possible, however, to start a session with the Apache server and then access the session cookie within the Ratchet code.
Apache server's index.html starts the session:
<?php
// Get the session ID.
$ses_id = session_id();
if (empty($ses_id)) {
session_start();
$ses_id = session_id();
}
?><!DOCTYPE html> ...
Ratchet MessageComponentInterface code accesses the session token:
public function onMessage(ConnectionInterface $from, $msg) {
$sessionId = $from->WebSocket->request->getCookies()['PHPSESSID'];
# Do stuff with the token...
}
Once both servers know the user's session token, they can use the token to share information through a MySQL database (which is what I do):
# Access session data from a database:
$stmt = $this->mysqli->prepare("SELECT * FROM users WHERE cookie=?");
$stmt->bind_param('s', $sessionId);
$stmt->execute();
$result = $stmt->get_result();
Alternatively, you could do a more exotic form of inter-process communication:
# Ratchet server:
$opts = array(
'http'=>array(
'method'=>'GET',
'header'=>"Cookie: PHPSESSID=$sessionId\r\n"
)
);
$context = stream_context_create($opts);
$json = file_get_contents('http://localhost:80/get_session_info.php', false, $context);
$session_data = json_decode($json);
# Apache server's get_session_info.php
# Note: restrict access to this path so that remote users can't dump
# their own session data.
echo json_encode($_SESSION);
solution2
1 2021-03-27 19:29:37
This might seem a bit hacky but it's the only way I could figure out how to accomplish this.
Assuming you already know the directory and sessionId you can read the data from the session file directly using session_encode() , session_decode() as follows. My session files are prefixed with sess_ which may not be the case for others so keep that in mind. Note that this will save and then restore any existing $_SESSION data after extracting the variables from the session file:
$contents = file_get_contents($sessionDir . 'sess_' . $sessionId);
$sessionData = $this->decodeSession($contents);
return $sessionData;
private function decodeSession($sessionString)
{
$currentSession = session_encode();
foreach ($_SESSION as $key => $value){
unset($_SESSION[$key]);
}
session_decode($sessionString);
$sessionVariables = $_SESSION;
foreach ($_SESSION as $key => $value){
unset($_SESSION[$key]);
}
session_decode($currentSession);
return $sessionVariables;
}
solution3
1 2022-02-11 18:17:53
To complete the answers of dmiller309 and fred, I can't comment yet:(
I wouldn't store the session in database, I would simply use the directory that save the sessions, searching for the one that interest me, using session_save_path() .
public function onMessage(ConnectionInterface $from, $msg) {
$session_file = session_save_path()."/sess_".$from->WebSocket->request->getCookies()['PHPSESSID'];
if(!file_exists($session_file))
// The session doesn't exist
return ;
$content = file_get_contents($session_file);
$session_id = "0";
foreach($sections = explode(";", $content) as $k => $section) {
$data = explode("|", $section, 2);
if(isset($data[0]) and $data[0] == "id" and isset($data[1]) and substr_count($data[1], '"') == 2) {
$session_id = substr($data[1], strpos($data[1], '"')+1, -1);
break;
}
}
if($session_id == "0")
// The session has no "id"
return ;
// ID stored in $session_id, equivalent to $_SESSION["id"]
}
Note: All sessions start with "sess_"
Note 2: I stored the session ID in a string , so I get it between quotes.
Note 3: I didn't use session_decode() for safety reason, as the result is stored in $_SESSION , I assume it might result in a Race Condition .
I didn't test, you can let me know if something doesn't work.
Of course, it's possible to do the same for the other values stored in your session.
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