PySide6.QtWebSockets.QWebSocketServer

class QWebSocketServer

Implements a WebSocket-based server. More…

Inheritance diagram of PySide6.QtWebSockets.QWebSocketServer

Synopsis

Methods

Virtual methods

Signals

Note

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Detailed Description

It is modeled after QTcpServer, and behaves the same. So, if you know how to use QTcpServer, you know how to use QWebSocketServer . This class makes it possible to accept incoming WebSocket connections. You can specify the port or have QWebSocketServer pick one automatically. You can listen on a specific address or on all the machine’s addresses. Call listen() to have the server listen for incoming connections.

The newConnection() signal is then emitted each time a client connects to the server. Call nextPendingConnection() to accept the pending connection as a connected QWebSocket . The function returns a pointer to a QWebSocket in QAbstractSocket::ConnectedState that you can use for communicating with the client.

If an error occurs, serverError() returns the type of error, and errorString() can be called to get a human readable description of what happened.

When listening for connections, the address and port on which the server is listening are available as serverAddress() and serverPort() .

Calling close() makes QWebSocketServer stop listening for incoming connections.

QWebSocketServer currently does not support WebSocket Extensions .

Note

When working with self-signed certificates, Firefox bug 594502 prevents Firefox to connect to a secure WebSocket server. To work around this problem, first browse to the secure WebSocket server using HTTPS. FireFox will indicate that the certificate is invalid. From here on, the certificate can be added to the exceptions. After this, the secure WebSockets connection should work.

QWebSocketServer only supports version 13 of the WebSocket protocol, as outlined in RFC 6455 .

There is a default connection handshake timeout of 10 seconds to avoid denial of service, which can be customized using setHandshakeTimeout() .

class SslMode

Indicates whether the server operates over wss (SecureMode) or ws (NonSecureMode)

Constant

Description

QWebSocketServer.SslMode.SecureMode

The server operates in secure mode (over wss)

QWebSocketServer.SslMode.NonSecureMode

The server operates in non-secure mode (over ws)
__init__(serverName, secureMode[, parent=None])
Parameters:

Constructs a new QWebSocketServer with the given serverName. The serverName will be used in the HTTP handshake phase to identify the server. It can be empty, in which case no server name will be sent to the client. The secureMode parameter indicates whether the server operates over wss ( SecureMode ) or over ws ( NonSecureMode ).

parent is passed to the QObject constructor.

acceptError(socketError)
Parameters:

socketError – SocketError

This signal is emitted when the acceptance of a new connection results in an error. The socketError parameter describes the type of error that occurred.

alertReceived(level, type, description)
Parameters:

QWebSocketServer emits this signal if an alert message was received from a peer. level tells if the alert was fatal or it was a warning. type is the code explaining why the alert was sent. When a textual description of the alert message is available, it is supplied in description.

Note

The signal is mostly for informational and debugging purposes and does not require any handling in the application. If the alert was fatal, underlying backend will handle it and close the connection.

Note

Not all backends support this functionality.

See also

alertSent() AlertType

alertSent(level, type, description)
Parameters:

QWebSocketServer emits this signal if an alert message was sent to a peer. level describes if it was a warning or a fatal error. type gives the code of the alert message. When a textual description of the alert message is available, it is supplied in description.

Note

This signal is mostly informational and can be used for debugging purposes, normally it does not require any actions from the application.

Note

Not all backends support this functionality.

See also

alertReceived() AlertType

close()

Closes the server. The server will no longer listen for incoming connections.

closed()

This signal is emitted when the server closed its connection.

See also

close()

error()
Return type:

CloseCode

Returns an error code for the last error that occurred. If no error occurred, CloseCodeNormal is returned.

See also

errorString()

errorString()
Return type:

str

Returns a human readable description of the last error that occurred. If no error occurred, an empty string is returned.

See also

serverError()

handleConnection(socket)
Parameters:

socket – QTcpSocket

Upgrades a tcp socket to websocket.

The QWebSocketServer object will take ownership of the socket object and delete it when appropriate.

handshakeInterruptedOnError(error)
Parameters:

error – QSslError

QWebSocketServer emits this signal if a certificate verification error was found and if early error reporting was enabled in QSslConfiguration.

handshakeTimeout()
Return type:

std::chrono::milliseconds

Returns the handshake timeout for new connections in milliseconds.

The default is 10 seconds. If a peer uses more time to complete the handshake their connection is closed.

handshakeTimeoutMS()
Return type:

int

Returns the handshake timeout for new connections in milliseconds.

The default is 10 seconds. If a peer uses more time to complete the handshake their connection is closed.

hasPendingConnections()
Return type:

bool

Returns true if the server has pending connections; otherwise returns false.

isListening()
Return type:

bool

Returns true if the server is currently listening for incoming connections; otherwise returns false. If listening fails, error() will return the reason.

See also

listen() error()

listen([address=QHostAddress.Any[, port=0]])
Parameters:
Return type:

bool

Tells the server to listen for incoming connections on address address and port port. If port is 0, a port is chosen automatically. If address is QHostAddress::Any, the server will listen on all network interfaces.

Returns true on success; otherwise returns false.

See also

isListening()

maxPendingConnections()
Return type:

int

Returns the maximum number of pending accepted connections. The default is 30.

nativeDescriptor()
Return type:

qintptr

Note

This function is deprecated.

Returns the native socket descriptor the server uses to listen for incoming instructions, or -1 if the server is not listening. If the server is using QNetworkProxy, the returned descriptor may not be usable with native socket functions.

newConnection()

This signal is emitted every time a new connection is available.

nextPendingConnection()
Return type:

QWebSocket

Returns the next pending connection as a connected QWebSocket object. QWebSocketServer does not take ownership of the returned QWebSocket object. It is up to the caller to delete the object explicitly when it will no longer be used, otherwise a memory leak will occur. nullptr is returned if this function is called when there are no pending connections.

Note: The returned QWebSocket object cannot be used from another thread.

originAuthenticationRequired(pAuthenticator)
Parameters:

pAuthenticator – QWebSocketCorsAuthenticator

This signal is emitted when a new connection is requested. The slot connected to this signal should indicate whether the origin (which can be determined by the origin() call) is allowed in the authenticator object (by issuing setAllowed() ).

If no slot is connected to this signal, all origins will be accepted by default.

Note

It is not possible to use a QueuedConnection to connect to this signal, as the connection will always succeed.

pauseAccepting()

Pauses incoming new connections. Queued connections will remain in queue.

peerVerifyError(error)
Parameters:

error – QSslError

QWebSocketServer can emit this signal several times during the SSL handshake, before encryption has been established, to indicate that an error has occurred while establishing the identity of the peer. The error is usually an indication that QWebSocketServer is unable to securely identify the peer.

This signal provides you with an early indication when something is wrong. By connecting to this signal, you can manually choose to tear down the connection from inside the connected slot before the handshake has completed. If no action is taken, QWebSocketServer will proceed to emitting sslErrors() .

See also

sslErrors()

preSharedKeyAuthenticationRequired(authenticator)
Parameters:

authenticator – QSslPreSharedKeyAuthenticator

QWebSocketServer emits this signal when it negotiates a PSK ciphersuite, and therefore a PSK authentication is then required.

When using PSK, the client must send to the server a valid identity and a valid pre shared key, in order for the SSL handshake to continue. Applications can provide this information in a slot connected to this signal, by filling in the passed authenticator object according to their needs.

Note

Ignoring this signal, or failing to provide the required credentials, will cause the handshake to fail, and therefore the connection to be aborted.

Note

The authenticator object is owned by the socket and must not be deleted by the application.

See also

preSharedKeyAuthenticationRequired()

proxy()
Return type:

QNetworkProxy

Returns the network proxy for this server. By default QNetworkProxy::DefaultProxy is used.

See also

setProxy()

resumeAccepting()

Resumes accepting new connections.

See also

pauseAccepting()

secureMode()
Return type:

SslMode

Returns the secure mode the server is running in.

See also

QWebSocketServer() SslMode

serverAddress()
Return type:

QHostAddress

Returns the server’s address if the server is listening for connections; otherwise returns QHostAddress::Null.

serverError(closeCode)
Parameters:

closeCode – CloseCode

This signal is emitted when an error occurs during the setup of a WebSocket connection. The closeCode parameter describes the type of error that occurred

See also

errorString()

serverName()
Return type:

str

Returns the server name that is used during the http handshake phase.

See also

setServerName()

serverPort()
Return type:

int

Returns the server’s port if the server is listening for connections; otherwise returns 0.

serverUrl()
Return type:

QUrl

Returns a URL clients can use to connect to this server if the server is listening for connections. Otherwise an invalid URL is returned.

setHandshakeTimeout(msec)
Parameters:

msec – int

This is an overloaded function.

setHandshakeTimeout(msec)
Parameters:

msec – std::chrono::milliseconds

Sets the handshake timeout for new connections to msec milliseconds.

By default this is set to 10 seconds. If a peer uses more time to complete the handshake, their connection is closed. You can pass a negative value (e.g. -1) to disable the timeout.

setMaxPendingConnections(numConnections)
Parameters:

numConnections – int

Sets the maximum number of pending accepted connections to numConnections. WebSocketServer will accept no more than numConnections incoming connections before nextPendingConnection() is called. By default, the limit is 30 pending connections.

QWebSocketServer will emit the error() signal with the CloseCodeAbnormalDisconnection close code when the maximum of connections has been reached. The WebSocket handshake will fail and the socket will be closed.

setNativeDescriptor(descriptor)
Parameters:

descriptor – qintptr

Return type:

bool

Note

This function is deprecated.

Sets the socket descriptor this server should use when listening for incoming connections to socketDescriptor.

Returns true if the socket is set successfully; otherwise returns false. The socket is assumed to be in listening state.

setProxy(networkProxy)
Parameters:

networkProxy – QNetworkProxy

Sets the explicit network proxy for this server to networkProxy.

To disable the use of a proxy, use the QNetworkProxy::NoProxy proxy type:

server->setProxy(QNetworkProxy::NoProxy);

See also

proxy()

setServerName(serverName)
Parameters:

serverName – str

Sets the server name that will be used during the HTTP handshake phase to the given serverName. The serverName can be empty, in which case an empty server name will be sent to the client. Existing connected clients will not be notified of this change, only newly connecting clients will see this new name.

See also

serverName()

setSocketDescriptor(socketDescriptor)
Parameters:

socketDescriptor – qintptr

Return type:

bool

Sets the socket descriptor this server should use when listening for incoming connections to socketDescriptor.

Returns true if the socket is set successfully; otherwise returns false. The socket is assumed to be in listening state.

setSslConfiguration(sslConfiguration)
Parameters:

sslConfiguration – QSslConfiguration

Sets the SSL configuration for the QWebSocketServer to sslConfiguration. This method has no effect if QWebSocketServer runs in non-secure mode ( NonSecureMode ).

setSupportedSubprotocols(protocols)
Parameters:

protocols – list of strings

Sets the list of protocols supported by the server to protocols.

socketDescriptor()
Return type:

qintptr

Returns the native socket descriptor the server uses to listen for incoming instructions, or -1 if the server is not listening. If the server is using QNetworkProxy, the returned descriptor may not be usable with native socket functions.

sslConfiguration()
Return type:

QSslConfiguration

Returns the SSL configuration used by the QWebSocketServer . If the server is not running in secure mode ( SecureMode ), this method returns QSslConfiguration::defaultConfiguration().

sslErrors(errors)
Parameters:

errors – .list of QSslError

QWebSocketServer emits this signal after the SSL handshake to indicate that one or more errors have occurred while establishing the identity of the peer. The errors are usually an indication that QWebSocketServer is unable to securely identify the peer. Unless any action is taken, the connection will be dropped after this signal has been emitted.

errors contains one or more errors that prevent QSslSocket from verifying the identity of the peer.

supportedSubprotocols()
Return type:

list of strings

Returns the list of protocols supported by the server.

supportedVersions()
Return type:

.list of QWebSocketProtocol.Version

Returns a list of WebSocket versions that this server is supporting.