Free squidguard software for linux

squidGuard is a combined filter, redirector and access controller plugin for Squid.
squidGuard can be used for next activities:
limit the web access for some users to a list of accepted/well known web servers and/or URLs only.
block access to some listed or blacklisted web servers and/or URLs for some users. **)
block access to URLs matching a list of regular expressions or words for some users. **)
enforce the use of domainnames/prohibit the use of IP address in URLs. **)
redirect blocked URLs to an "intelligent" CGI based info page. **)
redirect unregistered user to a registration form.
redirect popular downloads like Netscape, MSIE etc. to local copies.
redirect banners to an empty GIF. **)
have different access rules based on time of day, day of the week, date etc.
have different rules for different user groups.
Enhancements:
- The source block takes a new argument: continue. With this command an ipaddress or user can be configured in serval Sourceblocks. If a client is found but not blocked, squidGuard will continue to search in the next source block, if the continue command is defined. Thanks to Valentin Chopov for the patch

DansGuardian is an award winning web content filtering proxy for Linux, FreeBSD, OpenBSD, NetBSD, Mac OS X, HP-UX, and Solaris that uses Squid to do all the fetching. DansGuardian project filters using multiple methods. These methods include URL and domain filtering, content phrase filtering, PICS filtering, MIME filtering, file extension filtering, POST limiting.
The content phrase filtering will check for pages that contain profanities and phrases often associated with pornography and other undesirable content. The POST filtering allows you to block or limit web upload. The URL and domain filtering is able to handle huge lists and is significantly faster than squidGuard.
The filtering has configurable domain, user and source ip exception lists. SSL Tunneling is supported.
The configurable logging produces a log in an easy to read format which has the option to only log the text-based pages, thus significantly reducing redundant information such as every image on a page.
Pretty much all parts of DansGuardian are configurable thus giving the end administrator user total control over what is filtered and not some third-party company.
Main features:
- Significantly cheaper than IGear (one of the best commercial filters).
- Can block adverts by the use of an advert URL block list.
- Can filter text and HTML pages for obscene (sexual, racial, violent, etc) content.
- Uses an advanced phrase weighting system to reduce over or under blocking.
- Can filter sites using the PICS labeling system.
- Can filter according to MIME type and file extension.
- Can filter according to URLs including Regular Expression URLs.
- URL filtering is compatible with squidGuard black lists.
- The URL filtering is able to filter https requests.
- Can work in a whitelist mode where all sites except those listed are blocked.
- Can block all IP based URLs.
- Is able to block sites when users try using the IP address of the site instead.
- Produces a log in a very human readable format.
- Optionally produces a log in CSV format for east import into databases etc.
- Is able to log the username using either Ident or basic proxy authentication.
- It has the ability to switch off filtering for specified sites, parts of sites, browser IPs and usernames.
- Can block specified source IPs and usernames.
- Can block or limit web uploading (e.g. attachments in Hotmail).
- Has the ability to work in a stealth mode where it logs sites that would have been blocked, but does not block them. This allows you to monitor your users without them knowing.
- Uses a very intelligent algorithm to match phrases in web pages mixed in with HTML code and white space.
- Big5, Unicode and top-bit set characters can be used in search phrases.
- DansGuardian 2.4.0 is over 6 times faster than DansGuardian 1.x.x.
- URL filtering is significantly faster than squidGuard.
- The configuration lists use the same incredibly fast code that allows them all to be hundreds of thousands of entries long.
- 100% C++ and can compile on GCC 3.
- Can be made to re-read config files with a HUP signal.
- Works perfectly in conjunction with Squid and Oops. Also see this important information.
- Has no 3rd party library requirements (no nb++ as was used in version 1) so can be installed much easier and so is also provided as an RPM.
- Supports (adds) the squid X-Forwarded-For header line.
- Supports compressed (Content-Encoding gzip and deflate) HTML.
- Can be made to only listen on 1 IP.

Viralator is a Perl script that virus scans HTTP/FTP downloads request on a UNIX server after passing through the Squid proxy server.
Even when I implemented virus protection for my network email server we still continued to get the odd virus. Most of the viruses came from people using free webmail accounts like Hotmail or Yahoo and downloading the infected attachments to their machines or through downloading junk.
Rather than block access to the users I decided to look at how we could better protect the network. I looked at a couple of different products both comercial and free but they were either too expensive or did not meet my needs.
That is how Viralator was born. Viralator Proxy Virus Scanner is licenced under the GPL.
Viralator should work in any UNIX system that uses Apache and Squid servers. We have reports about successful instalations on:
- RedHat Linux
- Mandrake Linux
- SuSe Linux
- e-Smith Linux
- Slackware Linux
- Conectiva Linux
- Debian Gnu Linux
Supported Redirectors:
- Squirm
- SquidGuard
- Jesred
Supported Virus Scanners
- AntiVir
- AVP
- RAV
- Inoculate
- Sophos Sweep
- McAfee
- Trend
- Clamav
- Bit Defender (free edition)
The original concept for Viralator came from the Viromat project. Without Viromat the Viralator project would not have had a starting point. We can also thank Ralph Meyer for badgering me into releasing the script under the GPL.
Enhancements:
- Parenthesis are included on the regular expression used to validate URLs.
- The character set checking step, which was not working before last patch released, has been fixed.