searxng/searx/botdetection/http_connection.py

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""
Method ``http_connection``
--------------------------

The ``http_connection`` method evaluates a request as the request of a bot if
the Connection_ header is set to ``close``.

.. _Connection:
   https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Connection

"""
# pylint: disable=unused-argument

from typing import Optional
import flask
import werkzeug

from searx.tools import config
from ._helpers import too_many_requests


def filter_request(request: flask.Request, cfg: config.Config) -> Optional[werkzeug.Response]:
    if request.headers.get('Connection', '').strip() == 'close':
        return too_many_requests(request, "HTTP header 'Connection=close")
    return None