diff options
Diffstat (limited to 'searx/plugins/limiter.py')
| -rw-r--r-- | searx/plugins/limiter.py | 155 |
1 files changed, 16 insertions, 139 deletions
diff --git a/searx/plugins/limiter.py b/searx/plugins/limiter.py index 69bd576d4..d9566b92b 100644 --- a/searx/plugins/limiter.py +++ b/searx/plugins/limiter.py @@ -1,165 +1,42 @@ # SPDX-License-Identifier: AGPL-3.0-or-later # lint: pylint # pyright: basic -"""Some bot protection / rate limitation +"""see :ref:`limiter src`""" -To monitor rate limits and protect privacy the IP addresses are getting stored -with a hash so the limiter plugin knows who to block. A redis database is -needed to store the hash values. - -Enable the plugin in ``settings.yml``: - -- ``server.limiter: true`` -- ``redis.url: ...`` check the value, see :ref:`settings redis` -""" - -import re -import string -import random -from flask import request +import flask from searx import redisdb from searx.plugins import logger -from searx.redislib import incr_sliding_window, secret_hash +from searx.botdetection import limiter +from searx.botdetection import dump_request name = "Request limiter" description = "Limit the number of request" default_on = False preference_section = 'service' -logger = logger.getChild('limiter') - -block_user_agent = re.compile( - r'(' - + r'unknown' - + r'|[Cc][Uu][Rr][Ll]|[wW]get|Scrapy|splash|JavaFX|FeedFetcher|python-requests|Go-http-client|Java|Jakarta|okhttp' - + r'|HttpClient|Jersey|Python|libwww-perl|Ruby|SynHttpClient|UniversalFeedParser|Googlebot|GoogleImageProxy' - + r'|bingbot|Baiduspider|yacybot|YandexMobileBot|YandexBot|Yahoo! Slurp|MJ12bot|AhrefsBot|archive.org_bot|msnbot' - + r'|MJ12bot|SeznamBot|linkdexbot|Netvibes|SMTBot|zgrab|James BOT|Sogou|Abonti|Pixray|Spinn3r|SemrushBot|Exabot' - + r'|ZmEu|BLEXBot|bitlybot' - # unmaintained Farside instances - + r'|' - + re.escape(r'Mozilla/5.0 (compatible; Farside/0.1.0; +https://farside.link)') - + '|.*PetalBot.*' - + r')' -) - -PING_KEY = 'SearXNG_limiter.ping' -TOKEN_KEY = 'SearXNG_limiter.token' - - -def ping(): - redis_client = redisdb.client() - user_agent = request.headers.get('User-Agent', 'unknown') - x_forwarded_for = request.headers.get('X-Forwarded-For', '') - - ping_key = PING_KEY + user_agent + x_forwarded_for - redis_client.set(secret_hash(ping_key), 1, ex=600) - - -def get_token(): - redis_client = redisdb.client() - if not redis_client: - # This function is also called when limiter is inactive / no redis DB - # (see render function in webapp.py) - return '12345678' - token = redis_client.get(TOKEN_KEY) - if token: - token = token.decode('UTF-8') - else: - token = ''.join(random.choice(string.ascii_lowercase + string.digits) for _ in range(8)) - redis_client.set(TOKEN_KEY, token, ex=600) - return token - - -def token_is_valid(token): - valid = token == get_token() - logger.debug("token is valid --> %s", valid) - return valid - - -def is_accepted_request() -> bool: - # pylint: disable=too-many-return-statements - redis_client = redisdb.client() - user_agent = request.headers.get('User-Agent', 'unknown') - x_forwarded_for = request.headers.get('X-Forwarded-For', '') - - if request.path == '/healthz': - return True - if block_user_agent.match(user_agent): - logger.debug("BLOCK %s: %s --> detected User-Agent: %s" % (x_forwarded_for, request.path, user_agent)) - return False - - if request.path == '/search': - - c_burst_max = 2 - c_10min_max = 10 - - ping_key = PING_KEY + user_agent + x_forwarded_for - if redis_client.get(secret_hash(ping_key)): - logger.debug('got a ping') - c_burst_max = 15 - c_10min_max = 150 - else: - logger.debug('missing a ping') - - c_burst = incr_sliding_window(redis_client, 'IP limit, burst' + x_forwarded_for, 20) - c_10min = incr_sliding_window(redis_client, 'IP limit, 10 minutes' + x_forwarded_for, 600) - if c_burst > c_burst_max or c_10min > c_10min_max: - logger.debug("BLOCK %s: too many request", x_forwarded_for) - return False - - if len(request.headers.get('Accept-Language', '').strip()) == '': - logger.debug("BLOCK %s: missing Accept-Language", x_forwarded_for) - return False - - if request.headers.get('Connection') == 'close': - logger.debug("BLOCK %s: got Connection=close", x_forwarded_for) - return False - - accept_encoding_list = [l.strip() for l in request.headers.get('Accept-Encoding', '').split(',')] - if 'gzip' not in accept_encoding_list and 'deflate' not in accept_encoding_list: - logger.debug("BLOCK %s: suspicious Accept-Encoding", x_forwarded_for) - return False - - if 'text/html' not in request.accept_mimetypes: - logger.debug("BLOCK %s: Accept-Encoding misses text/html", x_forwarded_for) - return False - - if request.args.get('format', 'html') != 'html': - c = incr_sliding_window(redis_client, 'API limit' + x_forwarded_for, 3600) - if c > 4: - logger.debug("BLOCK %s: API limit exceeded", x_forwarded_for) - return False +logger = logger.getChild('limiter') - logger.debug( - "OK %s: '%s'" % (x_forwarded_for, request.path) - + " || 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" % user_agent - ) - return True +def pre_request(): + """See :ref:`flask.Flask.before_request`""" + val = limiter.filter_request(flask.request) + if val is not None: + http_status, msg = val + client_ip = flask.request.headers.get('X-Forwarded-For', '<unknown>') + logger.error("BLOCK (IP %s): %s" % (client_ip, msg)) + return 'Too Many Requests', http_status -def pre_request(): - if not is_accepted_request(): - return 'Too Many Requests', 429 + logger.debug("OK: %s" % dump_request(flask.request)) return None -def init(app, settings): +def init(app: flask.Flask, settings) -> bool: if not settings['server']['limiter']: return False - if not redisdb.client(): - logger.error("The limiter requires Redis") # pylint: disable=undefined-variable + logger.error("The limiter requires Redis") return False - app.before_request(pre_request) return True |