Method _is_websocket_upgrade

gunicorn/asgi/protocol.py:892–911

Check if request is a WebSocket upgrade. Per RFC 6455 Section 4.1, the opening handshake requires: - HTTP method MUST be GET - Upgrade header MUST be "websocket" (case-insensitive) - Connection header MUST contain "Upgrade"

(self, request)

            await request.drain_body()

    def _is_websocket_upgrade(self, request):
        """Check if request is a WebSocket upgrade.

        Per RFC 6455 Section 4.1, the opening handshake requires:
        - HTTP method MUST be GET
        - Upgrade header MUST be "websocket" (case-insensitive)
        - Connection header MUST contain "Upgrade"
        """
        # RFC 6455: The method of the request MUST be GET
        if request.method != "GET":
            return False

        upgrade = None
        connection = None
        for name, value in request.headers:
            if name == "UPGRADE":
                upgrade = value.lower()
            elif name == "CONNECTION":
                connection = value.lower()
        return upgrade == "websocket" and connection and "upgrade" in connection

    async def _handle_websocket(self, request, sockname, peername):
        """Handle WebSocket upgrade request."""