searxng/searx/botdetection/_helpers.py
Markus Heiser fd814aac86 [mod] isolation of botdetection from the limiter
This patch was inspired by the discussion around PR-2882 [2].  The goals of this
patch are:

1. Convert plugin searx.plugin.limiter to normal code [1]
2. isolation of botdetection from the limiter [2]
3. searx/{tools => botdetection}/config.py and drop searx.tools
4. in URL /config, 'limiter.enabled' is true only if the limiter is really
   enabled (Redis is available).

This patch moves all the code that belongs to botdetection into namespace
searx.botdetection and code that belongs to limiter is placed in namespace
searx.limiter.

Tthe limiter used to be a plugin at some point botdetection was added, it was
not a plugin.  The modularization of these two components was long overdue.
With the clear modularization, the documentation could then also be organized
according to the architecture.

[1] https://github.com/searxng/searxng/pull/2882
[2] https://github.com/searxng/searxng/pull/2882#issuecomment-1741716891

To test:

- check the app works without the limiter, check `/config`
- check the app works with the limiter and with the token, check `/config`
- make docs.live .. and read
  - http://0.0.0.0:8000/admin/searx.limiter.html
  - http://0.0.0.0:8000/src/searx.botdetection.html#botdetection

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
2023-11-01 06:44:56 +01:00

130 lines
4.6 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
# pylint: disable=missing-module-docstring, invalid-name
from __future__ import annotations
from ipaddress import (
IPv4Network,
IPv6Network,
IPv4Address,
IPv6Address,
ip_network,
)
import flask
import werkzeug
from searx import logger
from . import config
logger = logger.getChild('botdetection')
def dump_request(request: flask.Request):
return (
request.path
+ " || X-Forwarded-For: %s" % request.headers.get('X-Forwarded-For')
+ " || X-Real-IP: %s" % request.headers.get('X-Real-IP')
+ " || form: %s" % request.form
+ " || Accept: %s" % request.headers.get('Accept')
+ " || Accept-Language: %s" % request.headers.get('Accept-Language')
+ " || Accept-Encoding: %s" % request.headers.get('Accept-Encoding')
+ " || Content-Type: %s" % request.headers.get('Content-Type')
+ " || Content-Length: %s" % request.headers.get('Content-Length')
+ " || Connection: %s" % request.headers.get('Connection')
+ " || User-Agent: %s" % request.headers.get('User-Agent')
)
def too_many_requests(network: IPv4Network | IPv6Network, log_msg: str) -> werkzeug.Response | None:
"""Returns a HTTP 429 response object and writes a ERROR message to the
'botdetection' logger. This function is used in part by the filter methods
to return the default ``Too Many Requests`` response.
"""
logger.debug("BLOCK %s: %s", network.compressed, log_msg)
return flask.make_response(('Too Many Requests', 429))
def get_network(real_ip: IPv4Address | IPv6Address, cfg: config.Config) -> IPv4Network | IPv6Network:
"""Returns the (client) network of whether the real_ip is part of."""
if real_ip.version == 6:
prefix = cfg['real_ip.ipv6_prefix']
else:
prefix = cfg['real_ip.ipv4_prefix']
network = ip_network(f"{real_ip}/{prefix}", strict=False)
# logger.debug("get_network(): %s", network.compressed)
return network
_logged_errors = []
def _log_error_only_once(err_msg):
if err_msg not in _logged_errors:
logger.error(err_msg)
_logged_errors.append(err_msg)
def get_real_ip(request: flask.Request) -> str:
"""Returns real IP of the request. Since not all proxies set all the HTTP
headers and incoming headers can be faked it may happen that the IP cannot
be determined correctly.
.. sidebar:: :py:obj:`flask.Request.remote_addr`
SearXNG uses Werkzeug's ProxyFix_ (with it default ``x_for=1``).
This function tries to get the remote IP in the order listed below,
additional some tests are done and if inconsistencies or errors are
detected, they are logged.
The remote IP of the request is taken from (first match):
- X-Forwarded-For_ header
- `X-real-IP header <https://github.com/searxng/searxng/issues/1237#issuecomment-1147564516>`__
- :py:obj:`flask.Request.remote_addr`
.. _ProxyFix:
https://werkzeug.palletsprojects.com/middleware/proxy_fix/
.. _X-Forwarded-For:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-For
"""
forwarded_for = request.headers.get("X-Forwarded-For")
real_ip = request.headers.get('X-Real-IP')
remote_addr = request.remote_addr
# logger.debug(
# "X-Forwarded-For: %s || X-Real-IP: %s || request.remote_addr: %s", forwarded_for, real_ip, remote_addr
# )
if not forwarded_for:
_log_error_only_once("X-Forwarded-For header is not set!")
else:
from . import cfg # pylint: disable=import-outside-toplevel, cyclic-import
forwarded_for = [x.strip() for x in forwarded_for.split(',')]
x_for: int = cfg['real_ip.x_for'] # type: ignore
forwarded_for = forwarded_for[-min(len(forwarded_for), x_for)]
if not real_ip:
_log_error_only_once("X-Real-IP header is not set!")
if forwarded_for and real_ip and forwarded_for != real_ip:
logger.warning("IP from X-Real-IP (%s) is not equal to IP from X-Forwarded-For (%s)", real_ip, forwarded_for)
if forwarded_for and remote_addr and forwarded_for != remote_addr:
logger.warning(
"IP from WSGI environment (%s) is not equal to IP from X-Forwarded-For (%s)", remote_addr, forwarded_for
)
if real_ip and remote_addr and real_ip != remote_addr:
logger.warning("IP from WSGI environment (%s) is not equal to IP from X-Real-IP (%s)", remote_addr, real_ip)
request_ip = forwarded_for or real_ip or remote_addr or '0.0.0.0'
# logger.debug("get_real_ip() -> %s", request_ip)
return request_ip