Server setMaxConnections() config method

docs/Changelog.md

@@ -10,6 +10,7 @@
 
  * Server `getConnections()`, `getReadableConnections()`, `getWritableConnections()` (@sirn-se)
  * `onHandshake(...)` listener (will deprecate `onConnect(...)`) (@sirn-se)
+ * Server `setMaxConnections(int|null)` (@sirn-se)
 
 ### `3.0.0`
 

docs/Server.md

@@ -42,6 +42,8 @@ $server
     ->setTimeout(300)
     // Specify frame size in bytes (default 4096 bytes)
     ->setFrameSize(1024)
+    // Set maximum number of allowed connections (default is unlimited)
+    ->setMaxConnections(10)
     ;
 
 echo "port:         {$server->getPort()}\n";

examples/echoserver.php

@@ -14,6 +14,7 @@
  *  --ssl : Use SSL, default false
  *  --timeout <int> : Timeout in seconds, default 200 seconds
  *  --framesize <int> : Frame size in bytes, default 4096 bytes
+ *  --connections <int> : Max number of connections, default unlimited
  *  --debug : Output log data (if logger is available)
  */
 
@@ -28,7 +29,7 @@
 // Server options specified or default
 $options = array_merge([
     'port'  => 80,
-], getopt('', ['port:', 'ssl', 'timeout:', 'framesize:', 'debug']));
+], getopt('', ['port:', 'ssl', 'timeout:', 'framesize:', 'connections:', 'debug']));
 
 // Initiate server.
 try {
@@ -51,6 +52,10 @@
         $server->setFrameSize($options['framesize']);
         echo "# Set frame size: {$options['framesize']}\n";
     }
+    if (isset($options['connections'])) {
+        $server->setMaxConnections($options['connections']);
+        echo "# Set max connections: {$options['connections']}\n";
+    }
 
     echo "# Listening on port {$server->getPort()}\n";
     $server->onHandshake(function ($server, $connection, $request, $response) {
@@ -136,6 +141,6 @@
     })->onError(function ($server, $connection, $exception) {
         echo "> Error: {$exception->getMessage()}\n";
     })->start();
-} catch (Throwable $e) {
+} catch (\Throwable $e) {
     echo "# ERROR: {$e->getMessage()}\n";
 }

examples/random_server.php

@@ -11,8 +11,10 @@
  *
  * Console options:
  *  --port <int> : The port to listen to, default 80
+ *  --ssl : Use SSL, default false
  *  --timeout <int> : Timeout in seconds, random default
  *  --framesize <int> : Frame size as bytes, random default
+ *  --connections <int> : Max number of connections, default unlimited
  *  --debug : Output log data (if logger is available)
  */
 
@@ -38,7 +40,7 @@
     'port'      => 80,
     'timeout'   => rand(1, 60),
     'framesize' => rand(1, 4096) * 8,
-], getopt('', ['port:', 'ssl', 'timeout:', 'framesize:', 'debug']));
+], getopt('', ['port:', 'ssl', 'timeout:', 'framesize:', 'connections:', 'debug']));
 
 // Initiate server.
 try {
@@ -47,6 +49,7 @@
         ->addMiddleware(new \WebSocket\Middleware\CloseHandler())
         ->addMiddleware(new \WebSocket\Middleware\PingResponder())
         ;
+    $server->setMaxConnections(1);
 
     // If debug mode and logger is available
     if (isset($options['debug']) && class_exists('WebSocket\Test\EchoLog')) {
@@ -61,6 +64,10 @@
         $server->setFrameSize($options['framesize']);
         echo "# Set frame size: {$options['framesize']}\n";
     }
+    if (isset($options['connections'])) {
+        $server->setMaxConnections($options['connections']);
+        echo "# Set max connections: {$options['connections']}\n";
+    }
 
     echo "# Listening on port {$server->getPort()}\n";
     $server->onHandshake(function ($server, $connection, $request, $response) {
@@ -105,6 +112,6 @@
                 break;
         }
     })->start();
-} catch (Throwable $e) {
+} catch (\Throwable $e) {
     echo "> ERROR: {$e->getMessage()}\n";
 }

src/Server.php

@@ -67,6 +67,7 @@ class Server implements LoggerAwareInterface, Stringable
     private bool $running = false;
     private array $connections = [];
     private array $middlewares = [];
+    private int|null $maxConnections = null;
 
 
     /* ---------- Magic methods ------------------------------------------------------------------------------------ */
@@ -157,7 +158,7 @@ public function getTimeout(): int
      */
     public function setFrameSize(int $frameSize): self
     {
-        if ($frameSize < 1) {
+        if ($frameSize < 3) {
             throw new InvalidArgumentException("Invalid frameSize '{$frameSize}' provided");
         }
         $this->frameSize = $frameSize;
@@ -257,6 +258,20 @@ public function addMiddleware(MiddlewareInterface $middleware): self
         return $this;
     }
 
+    /**
+     * Set maximum number of connections allowed, null means unlimited.
+     * @param int|null $maxConnections
+     * @return self
+     */
+    public function setMaxConnections(int|null $maxConnections): self
+    {
+        if ($maxConnections < 1) {
+            throw new InvalidArgumentException("Invalid maxConnections '{$maxConnections}' provided");
+        }
+        $this->maxConnections = $maxConnections;
+        return $this;
+    }
+
 
     /* ---------- Messaging operations ----------------------------------------------------------------------------- */
 
@@ -417,6 +432,10 @@ protected function createSocketServer(): void
     protected function acceptSocket(SocketServer $socket): void
     {
         try {
+            if (!is_null($this->maxConnections) && $this->getConnectionCount() >= $this->maxConnections) {
+                $this->logger->warning("[server] Denied connection, reached max {$this->maxConnections}");
+                return;
+            }
             $stream = $socket->accept();
             $name = $stream->getRemoteName();
             $this->streams->attach($stream, $name);

tests/suites/server/ConfigErrorTest.php

@@ -56,4 +56,13 @@ public function testInvalidFrameSize(): void
         $server = new Server();
         $server->setFrameSize(0);
     }
+
+    public function testInvalidMaxConnections(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionCode(0);
+        $this->expectExceptionMessage("Invalid maxConnections '0' provided");
+        $server = new Server();
+        $server->setMaxConnections(0);
+    }
 }

tests/suites/server/ConfigTest.php

@@ -113,6 +113,7 @@ public function testServerConfiguration(): void
         });
         $this->assertSame($server, $server->setTimeout(300));
         $this->assertSame($server, $server->setFrameSize(64));
+        $this->assertSame($server, $server->setMaxConnections(64));
         $this->assertSame($server, $server->addMiddleware(new Callback()));
 
         $this->assertEquals('WebSocket\Server(ssl://0.0.0.0:9000)', "{$server}");

tests/suites/server/ServerTest.php

@@ -658,4 +658,39 @@ public function testUnmaskedException(): void
         $this->expectSocketStreamClose();
         unset($server);
     }
+
+    public function testMaxConnectionsOverflow(): void
+    {
+        $this->expectStreamFactory();
+        $server = new Server(8000);
+        $server->setStreamFactory(new StreamFactory());
+        $server->setMaxConnections(1);
+
+        $this->expectWsServerSetup(scheme: 'tcp', port: 8000);
+        $this->expectWsSelectConnections(['@server']);
+        $this->expectSocketServerAccept();
+        $this->expectSocketStream();
+        $this->expectSocketStreamGetMetadata();
+        $this->expectSocketStreamGetRemoteName()->setReturn(function () {
+            return 'fake-connection-1';
+        });
+        $this->expectStreamCollectionAttach();
+        $this->expectSocketStreamGetLocalName()->setReturn(function () {
+            return 'fake-connection-1';
+        });
+        $this->expectSocketStreamGetRemoteName();
+        $this->expectSocketStreamSetTimeout();
+        $this->expectWsServerPerformHandshake();
+        $this->expectSocketStreamIsConnected();
+        $this->expectWsSelectConnections(['@server'])->addAssert(function () use ($server) {
+            $server->stop();
+        });
+
+        $server->start();
+        $this->assertEquals(1, $server->getConnectionCount());
+
+        $this->expectSocketStreamIsConnected();
+        $this->expectSocketStreamClose();
+        unset($server);
+    }
 }