pybl

Squid helper handling squidguard blacklists written in python

• Only supports domains blacklists actually (ie : google.com, www.google.com, mail.google.com, etc.)
• In config specified blacklists are loaded in memory or CDB backend using https://github.com/bbayles/python-pure-cdb
• Usable as an external acl plugin for squid 3
• Written because of poor development on squidguard and some issues using blacklists on squid
• Python 3 supported as of 2020
• Similar tool in Golang will replace this one in the future

Usage

Add this configuration to squid.conf :

external_acl_type urlblacklist_lookup ttl=5 %DST /usr/bin/python /usr/local/pybl/pybl.py
...
acl urlblacklist external urlblacklist_lookup
...
http_access deny urlblacklist

Config file must be include following statements

url = http://dsi.ut-capitole.fr/blacklists/download/blacklists.tar.gz
basedir = /usr/local/pybl/
categories = adult,malware  # categories are coma separated values
backend = cdb

• url : squidguard-like blacklists files, this variable is not already usable
• basedir : root path containing blacklists files, metadata (update datetime)
• categories : blacklists to use for filtering
• backend : database flavour (ram|cdb)

TODO

• Auto-fetcher using url if blacklists are not already downloaded or stored on the squid machine (wip)
• Compatibility with python3 only
• Filters for regex urls
• Code optimisation (profiling) and cleaning (wip)
• Tests (wip)
• ...

DBs support ideas

• High performance but heavy RAM usage when using dict()
• Sqlite3 tested, small memory footprint, but very slow
• CDB backend seems to be as fast as attended, with a very small footprint

DBs Benchmarks (2016)

RAM usage for one thread with categories ["adult","malware"]

Debian 8 / python 2.7.9 / squid 3.4.8

• ram : 90Mo
• cdb : 6Mo

Ubuntu 20.04 / python 3.8.2 / squid 4.9

• ram : 249Mo
• cdb : 12Mo

License

Copyright (c) 2020 PaulBSD
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
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