Introduction

• Pål Marius Baltzersen
• Lars-Erik Håland

• It can filter the surfing duration on a user basis.

• In english.
• An unofficial Faq

Comparison

Competitors

• websify from Gotzon Astondoa is a free filter for windows. It can use our blacklists.
• urlfiterservice a software for any browser on Windows (XP, 7, 10 )
• ufdbguard is a free and fast (8-9 time faster than squidguard) redirector which can use an commercial URL database : http://www.urlfilterdb.com
• http://tatewake.com/projects.htm Tatewake works on windows and is written in JAVA. It use use squidguard's database to create a hosts file for windows.
• http://soulcatcher.sourceforge.net Soulcatcher is very similar to squidguard
• http://software.othello.ch/mod_dnsbl a blocking DNS-based module designed apache and Squid. It can use our database.
• An access module for filtering ISA server
• redirector from Ian Lea is written in Perl. It was the first redirector available. Slow, and hungry of memory.
• Squirm 1.0b First redirector written in C. Faster, and more careful of memory usage than redirector. No more available.
• JunkBuster which is not really a redirector (in Squid sense) but more a second proxy to connect to squid. It strips banners in web page.
• Jesred "Son" of squirm. Faster, a little more memory is needed.
• Custodian. It "hashed" its blocklist to hide urls. No more available file. I haven't test it.
• RedServer. Another one. No more available.
• DansGuardian Son of active guardian, it looks for content and PICS level. It's now a competitor, no more a complement of SquidGuard. It's a filtering proxy and not a redirector.
• E2guardian Son of Dansguardian, it looks for content and PICS level. It use also urls filtering.
• Many commercial sites sells filtering databases and software.
  • http://www.cyberpatrol.com
  • http://www.websense.com
  • http://www.languard.com
  • http://www.n2h2.com
  • http://www.rulespace.com
  • http://www.surfcontrol.com
  • http://www.xdetect.com

Advantages

• It's a lot faster : for a 2.000 Urls list to filter and a 11.000 Urls database, on a pentium 233 :
  • Squirm : 2 minutes 25 seconds
  • Jesred : 1 minute 45 seconds
  • SquidGuard : 9 seconds !!!
  We can say, it doesn't care of database size :
  • a 100 Urls database tooks 6 seconds
  • a 11000 Urls database tooks 9 seconds (now the adult database contains 100 000 urls)
• Faster, in our case, is equal to "less redirector needed" : 20 for squidguard, 25 for squirm. Following a chart of redirector usage
  
  • with squirm you need 3 redirectors 60% of time, with squidguard, only 5%
  • with squirm you need 7 redirectors 10% of time, with squidguard, less than 0.5 %
  
• It can redirect url depending on :
  • IP adress of client
  • User identity (RFC 1413) or login/password
  • URL (of course)
  • "Class" of redirection (e.g. we can define a class banner, adult, and so on...)
• If database size doesn't matter, it means that we can put MANY urls. So we use less generic regular expression, which make many errors (the computer xxx in nasa.gov domains e.g.)

contrib

Some databases

• http://www.squidblacklist.org/,
• http://squidguard.mesd.k12.or.us/blacklists.tgz (mixed of bn-paf, our database and some local additions)
• http://www.shallalist.de/ squidguard maintainers,
• http://urlblacklist.com a commercial one,

Related Projects

• http://www.surbl.org is a site to prevent spam. As we know, porno-business like spam. Surbl will, likely, create a DNS zone for adult web site...

FAQ

• Squid 2.6 isn't working : it replace
  • redirect_program by url_rewrite_program
  • redirect_children by url_rewrite_children
  • A new command appears url_rewrite_concurrency
• Nothing is blocked Many reasons :
  • Unix access right are incorrect. The user who launch squid, is the same who launch squidguard. So, this user must be able to read text database and to write db file, and log file. So, directory looks like this :

    		drwxr-xr-x  2 root     root	     1024 avr  2  2001 logs
    		-rw-r-----  1 squid    squid	   100000 oct 23 08:13 logs/squidGuard.log
    		-rw-r-----  1 squid    squid	     1000 oct 23 08:13 logs/squidGuard.error
    		drwxr-xr-x  2 root     root	     1024 avr  2  2001 db
    		drwxr-xr-x  2 root     root	     1024 avr  2  2001 db/dest
    		drwxr-xr-x  2 squid    squid	     1024 avr  2  2001 db/dest/adult
    		-rw-r--r--  1 squid    squid	     1024 avr  2  2001 db/dest/adult/domains
    		-rw-r--r--  1 squid    squid	     1024 avr  2  2001 db/dest/adult/domains.db
    		-rw-r--r--  1 squid    squid	     1024 avr  2  2001 db/dest/adult/urls
    		-rw-r--r--  1 squid    squid	     1024 avr  2  2001 db/dest/adult/urls.db
    		...
    		drwxr-xr-x  2 squid    squid	     1024 avr  2  2001 db/dest/warez
    		...
    		drwxr-xr-x  2 root     root          1024 avr  2  2001 db/src
    		...
    		

  • You forgot none at the end of rule. Default is "accept"
  • You made a syntax error. temporal definition are quite tricky.
• I can't download blacklist. Many reasons :
  • You, or your entreprise, are protected by a "low level" firewall which is unable to understand "active ftp". Check your ftp client, and change mode to "passive ftp".
  • You, or your entreprise, are protected by a "too sensitive" "high level" firewall which say that length of file path are too longue. Firewall1 (Checkpoint) is one of these. Look at ftp://ftp.ut-capitole.fr/blacklist which is a link to ftp://ftp.ut-capitole.fr/pub/cache/squidguard_contrib. May Help

Definition

• Redirector :
  Official Squid FAQ definition : http://squid.nlanr.net/Squid/FAQ/FAQ-15.html
  A redirector is a program which connects to Squid and allows to "translate" URLs before sending them to Squid Process :
  • for restricting access (erotic or financial Urls)
  • for stripping banners to accelerate web usage
  • for redirecting Urls on a local mirror (Netscape Navigator downloading e.g.)
  To put them in place, uncomment redirector line in squid.conf and enter children processes you need : redirect_program /usr/local/squidGuard/bin/squidGuard
  redirect_children 20
  Common redirectors use from 800 Ko to 1600 Ko.
  You can also, if you don't care about very rare "workaround" (less than 0.01%) accept to bypass redirector if they are all busy, by adding this line. redirector_bypass on