File: faq.html

package info (click to toggle)
squidguard 1.2.0-5
links: PTS
area: main
in suites: sarge
size: 2,924 kB
ctags: 243
sloc: perl: 2,796; yacc: 1,945; ansic: 1,458; makefile: 420; sh: 224; lex: 74
file content (609 lines) | stat: -rw-r--r-- 16,515 bytes
parent folder | download | duplicates (3)
<HTML>

 <HEAD>
  <TITLE>squidGuard - FAQ</TITLE>
  <META name="keywords" lang="en" content="faq,squidGuard,squidguard,squid,Squid,free,redirector,filter">
  <META name="author" content="Pl Baltzersen">
  <META name="copyright" content="&copy; 2000 ElTele st AS.">
 </HEAD>

 <!-- Background white, links blue (unvisited), navy (visited), red (active) -->
 <BODY
  BACKGROUND="/images/background.jpg"
  BGCOLOR="#8EE5EE"
  TEXT="#000000"
  LINK="#0000FF"
  VLINK="#000080"
  ALINK="#FF0000">

  

  <TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0 WIDTH=100%>
   <TR>
    <TD ALIGN=LEFT VALIGN=TOP>
     <TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0>
      <TR>
       <TD ALIGN=LEFT VALIGN=BOTTOM>
	<A HREF="http://ftp.ost.eltele.no/pub/www/proxy/squidGuard/"><IMG
	SRC="/images/squidGuard.gif" BORDER=0
	VALIGN=TOP></A>
	<FONT SIZE=+3>
	 <B>The squidGuard FAQ</B>
	</FONT>
	<IMG SRC="/images/faq.gif" BORDER=0 VALIGN=TOP>
       </TD>
      </TR>
      <TR>
       <TH ALIGN=LEFT VALIGN=TOP>
	<FONT SIZE=-1>
	 <A HREF="/">squidGuard</A> is an ultrafast and free filter,
	 redirector and access controller for <A
	 HREF="http://www.squid-cache.org/">Squid</A>
	 <BR>
	 By <A HREF="/authors/">Pl Baltzersen</A> and <A
	 HREF="/authors/">Lars Erik Hland</A>
	 <BR>
	 <A HREF="/copyright/">Copyright</A> &copy; 1999-2000, <A
	 HREF="http://www.ost.eltele.no/">ElTele st AS</A>
	</FONT>
       </TH>
      </TR>
     </TABLE>
    </TD>
    <TD ALIGN=RIGHT VALIGN=TOP>
     <TABLE CELLPADDING=0 CELLSPACING=0 BORDER=0>
      <TR>
       <TH ALIGN=RIGHT>
	<FONT SIZE=-1>
	 <BR>
	 This page was last modified 2000-08-23
	</FONT>
       </TH>
      </TR>
     </TABLE>
    </TD>
   </TR>
  </TABLE>

  <BR>
  <BR>
  <BR>

  <H2>
   <IMG SRC="/images/arrow-red.gif" BORDER=0 VALIGN=BOTTOM>
   <A NAME="FAQ"></A>
   FAQ - Frequently Asked/Answered Questions
  </H2>

  <P>
   Currently in semirandom order:
  </P>
  <OL>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="1"></A>
       <A NAME="maillist"></A>
       Is there a mailing list for squidGuard?
      </B>
     </DT>
     <DD>
      <A
      HREF="/contact/">Yes!</A>.
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="2"></A>
       <A NAME="db3x"></A>
       I have db3.x.x installed and squidGuard won't compile?
      </B>
     </DT>
     <DD>
      Only <A HREF="http://ftp.ost.eltele.no/pub/db/">db2.x.x</A>
      versions are supported. We are working on db3.x.x support, but
      the API has changed so it may take a while to fix.
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="3"></A>
       <A NAME="implicit"></A>
       squidGuard does not block?
      </B>
     </DT>
     <DD>
      There my be at least 2 reasons for this:
      <OL>
       <LI>
        You didn't end your pass rules with "none". Pass rules ends
        with an implicit "all". It is good practice to allways en the
        pass rules with either "all" or "none" to make them clear. Ie.
        use:
	<BR>
	<TT>pass good none</TT>
	<BR>
	or
	<BR>
	<TT>pass good !bad all</TT>
       </LI>
       <LI>
        squidGuard goes into emergency mode. Reasons may be syntax
        errors in the config file, reference to non existing database
        files, filprotection problems or missing directories. Check
        the squidGuard log.
	<BR>
        <B>Note:</B>When run under Squid, squidGuard is run with the
        same user and group ID as Squid
        (<B><TT>cache_effective_user</TT></B> and
        <B><TT>cache_effective_group</TT></B> in squid.conf). The
        squidGuard configuration and database files must be readable
        for this user and/or group and the squidGuard log directory
        must be writable for this user and/or group. If not squidGuard
        will go into the "pass all for all" emergency mode.
       </LI>
      </OL>
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="4"></A>
       <A NAME="debug"></A>
       How do I debug squidGuard?
      </B>
     </DT>
     <DD>
      Do something like this:
      <BR>
      <B><TT>echo&nbsp;"http://foo/bar&nbsp;10.0.0.1/-&nbsp;-&nbsp;GET"&nbsp;|&nbsp;/usr/local/bin/squidGuard&nbsp;-c&nbsp;/tmp/test.cfg&nbsp;-d</TT></B>
      <BR>
      This redirects the log to stderr. The response is either a blank
      line (pass on) or a the input with the URL part rewritten
      (redirect).
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="5"></A>
       <A NAME="av"></A>
       How can I block audio and video?
      </B>
     </DT>
     <DD>
      Use an <A HREF="/config/#Expressionlists">expressionlist</A>
      with something like this:
      <BR>
      <B><TT>\.(ra?m|mpe?g?|mov|movie|qt|avi|dif|dvd?|mpv2|mp3)($|\?)</TT></B>
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="6"></A>
       <A NAME="blacklist_project"></A>
       Are there any blacklist exchange plans?
      </B>
     </DT>
     <DD>
      Yes, we plan to add an interface to the new web site to allow
      proxyadministrators to indirectly add and remove URLs from the
      robot config. Though there are still some practical issues to
      solve.
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="7"></A>
       <A NAME="blacklist_contrib"></A>
       How can I contribute to the blacklists?
      </B>
     </DT>
     <DD>
      If you have lists of links that would map to missing blacklist
      entries, or lists of exceptions/errors, please send them to <A
      HREF="mailto:blacklist@squidguard.org">blacklist@squidguard.org</A>
      <BR>
      <B>Note</B>: The link list must consist of fully qualified URLs,
      ie. http://... (<U>not</U> the blacklist format).
      <BR>
      The exception/error lists must consist of domains and urls as
      (potentially) found in the blacklists.
      <BR>
      Direct additions to the domain and url lists are not very
      usefull, since they are the output from the robot; not the
      input.  Though if you have a long list that would have been
      usefull you may of course <I>reverse engineer</I> it through:
      <BR>
      <TT>sed&nbsp;'s@^@http://www.@;s@$@/@'&nbsp;domains&nbsp;urls&nbsp;&gt;links</TT>
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="8"></A>
       <A NAME="testing_timeconstraints"></A>
       How can I test timeconstraints
      </B>
     </DT>
     <DD>
      You can set a simulated start time with the
      <TT><B>-t&nbsp;<EM>yyyy-mm-dd</EM>T<EM>HH:MM:SS</EM></B></TT>
      option:
      <DL>
       <DD>
	<TT>
	 <B>
	  squidGuard&nbsp;-c&nbsp;test.conf&nbsp;-t&nbsp;1999-12-31T23:59:30&nbsp;-d&nbsp;&lt;test.in&gt;test.out&nbsp;2&gt;test.log
	 </B>
	</TT>
       </DD>
      </DL>
      With the -t option squidGuard parses the given date&amp;time and
      calculates an offset from the current time at startup and then
      adds this offset to all timevalues during runtime.
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="9"></A>
       <A NAME="no_args_form_squid"></A>
       squidGuard compiles fine and the tests succeed, but it seems to
       pass all when run under Squid
      </B>
     </DT>
     <DD>
      There may be at leaste two reasons for this:
      <UL>
       <LI>
        Some versions of Squid (supposedly 2.2.*) silently ignores
        argumets to the right of
        <B><TT>redirect_program&nbsp;<I>prefix</I>/bin/squidGuard</TT></B>. Solutions
        are one of:
	<UL>
	 <LI>
	  Set the actual config file location at <A
	  HREF="/install/#Defaultconfigfile">compiletime</A>
	  with <B><TT>--with-sg-config</TT></B>
	 </LI>
	 <LI>
	  Use a shell wraper with
	  <B><TT>redirect_program&nbsp;<I>prefix</I>/bin/squidGuard.sh</TT></B>
	  and make <TT><I>prefix</I>/bin/squidGuard.sh</TT> an
	  executable shell like:
	  <DL>
	   <DD>
	    <TT>
	     <B>
	      #! /bin/sh -
	      <BR>
	      exec&nbsp;<I>prefix</I>/bin/squidGuard&nbsp;-c&nbsp;<I>whatever</I>/squidGuard.conf
	     </B>
	    </TT>
	   </DD>
	  </DL>
	 </LI>
	</UL>
       </LI>
       <LI>
        When run under Squid, squidGuard is run with the same user and
        group ID as Squid (<B><TT>cache_effective_user</TT></B> and
        <B><TT>cache_effective_group</TT></B> in squid.conf). The
        squidGuard configuration and database files must be readable
        for this user and/or group and the squidGuard log directory
        must be writable for this user and/or group. If not squidGuard
        will go into the "pass all for all" emergency mode.
       </LI>
      </UL>
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="10"></A>
       <A NAME="native_lex"></A>
       compilation of sg.l on fails with <TT>"sg.l:line ...: Error:
       Too many positions"</TT> with native lex
      </B>
     </DT>
     <DD>
      Some native versions of lex have problems with sg.l. The
      solution is to use <A HREF="/links/#Flex">GNU flex</A> wich is better
      anyway. Do "<TT>setenv LEX flex</TT>" if configure selects the
      native lex before flex. Flex should compile <I>right out of the
      box</I> similar to other GNU programs. (Thanks to
      laurent.foulonneau@mail.loyalty.nc).
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="11"></A>
       <A NAME="auth_module"></A>
       Can I use proxy authenticated user the same way as RFC931/Ident
       user?
      </B>
     </DT>
     <DD>
      Yes, if you patch Squid &lt; 2.3 with this simple <A
      HREF="http://ftp.ost.eltele.no/pub/www/proxy/squidGuard/contrib/squid-2.2-authuser.patch">diff</A>,
      kindly contributed by <A
      HREF="mailto:antony@abacus.co.uk">Antony T Curtis</A>, the
      authenticated user will be passed from Squid to squidGuard. This
      patch has apparently already been incorporated in squid-2.3:
      <BR>
      <TT>
       <PRE>
	A useful patch to Squid 2.2STABLE which fixes per-user redirection where
	the user is authenticated using proxy-auth...

	*** src/redirect.c.orig Tue Jun 22 14:04:43 1999
	--- src/redirect.c      Tue Jun 22 15:46:41 1999
	***************
	*** 103,108 ****
	--- 103,110 ----
	      cbdataAdd(r, cbdataXfree, 0);
	      r-&gt;orig_url = xstrdup(http-&gt;uri);
	      r-&gt;client_addr = conn-&gt;log_addr;
	+     if (http-&gt;request-&gt;user_ident[0])
	+       r-&gt;client_ident = http-&gt;request-&gt;user_ident; else
	      if (conn-&gt;ident == NULL || *conn-&gt;ident == '\0') {
		r-&gt;client_ident = dash_str;
	      } else {</PRE>
      </TT>
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="12"></A>
       <A NAME="perl"></A>
       Can I manipulate domains.db and urls.db from Perl?
      </B>
     </DT>
     <DD>
      Yes, but you must bind custom comparefunctions. Also note the
      domains are stored with a leading ".":
      <BR>
      <TT>
       <PRE>
        use DB_File;

	sub mirror($) {
	  scalar(reverse(shift));
	}

	sub domainmatch($$) {
	  my $search = mirror(lc(shift));
	  my $found = mirror(lc(shift));
	  if ("$search." eq $found) {
	    return(0);
	  } else {
	    return(substr($search,0,length($found)) cmp $found);
	  }
	}

	sub urlmatch($$) {
	  my $search = lc(shift) . "/";
	  my $found = lc(shift) . "/";
	  if ($search eq $found) {
	    return(0);
	  } else {
	    return(substr($search,0,length($found)) cmp $found);
	  }
	}

	my (%url,%domain);

	$DB_BTREE-&gt;{compare} = \&amp;urlmatch;
	my $url_db = tie(%url, "DB_File", "urls.db", O_CREAT|O_RDWR, 0664, $DB_BTREE)
	|| die("urls.db: $!\n");

	$DB_BTREE-&gt;{compare} = \&amp;domainmatch;
	my $domain_db = tie(%domain, "DB_File", "domains.db", O_CREAT|O_RDWR, 0664, $DB_BTREE)
	|| die("domains.db: $!\n");

	# Now you can operate on %url and %domain just as normal perl hashes:)
	# Add "playboy.com" to the domainlist unless it's already there:
	$domain{".playboy.com"} = "" unless(exists($domain{"playboy.com"}));
	# or use the DB_File functions put, get, del and seq:
	# Add "sex.com" and "dir.yahoo.com/business_and_economy/companies/sex"
	# and delete "cnn.com":
	$domain_db-&gt;put(".sex.com","") unless(exists($domain{"sex.com"}));
	$domain_db-&gt;sync; # Seems to only sync the last change.
	$domain_db-&gt;del("cnn.com") if(exists($domain{"cnn.com"}));
	$domain_db-&gt;sync; # Seems to only sync the last change.
	$url_db-&gt;put("xyz.com/~sex","") unless(exists($url{"xyz.com/~sex"}));
	$url_db-&gt;sync; # Seems to only sync the last change.

	$url_db-&gt;sync; # Seems to only sync the last change.
	$domain_db-&gt;sync; # Seems to only sync the last change.
	undef($url_db); # Destroy the object
	undef($domain_db); # Destroy the object
	untie(%url); # Sync and close the file and undef the hash
	untie(%domain); # Sync and close the file and undef the hash</PRE>
      </TT>
      See the perltie(1) and DB_File(3) man pages that comes with Perl for more info.
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="13"></A>
       <A NAME="listdb"></A>
       How can I list domains.db or urls.db from Perl?
      </B>
     </DT>
     <DD>
      Use a script like this:
      <BR>
      <TT>
       <PRE>
	#!/local/bin/perl -w
	use strict;
	use DB_File;

	foreach (@ARGV) {
	  my (%db, $key, $val);
	  die("$_: $!\n") unless(-f);
	  tie(%db, "DB_File", $_, O_RDONLY, 0664, $DB_BTREE) || die("$_: $!\n");
	  foreach $key (keys(%db)) {
	    if($val = $db{$key}) {
	      $val = "\"$val\"";
	    } else {
	      $val = "undef";
	    }
	    print "$key -&gt; $val\n";
	  }
	  untie(%db);
	}</PRE>
      </TT>
      See the perltie(1) and DB_File(3) man pages that comes with Perl for more info.
     </DD>
    </DL>
   </LI>
   <BR>
   <LI>
    <DL>
     <DT>
      <B>
       <A NAME="14"></A>
       <A NAME="/bin/false"></A>
       How can I get around "make: don't know how to make /bin/false. Stop"?
      </B>
     </DT>
     <DD>
      Your system does not have lynx and not /bin/false either: If it
      has /usr/bin/false do:
      <BR>
      <TT>
       <PRE>
	# ln -s ../usr/bin/false /bin/.</PRE>
      </TT>
      Alternatively:
      <BR>
      <TT>
       <PRE>
	# echo exit 255 >/bin/false
	# chmod a+rx /bin/false</PRE>
      </TT>
     </DD>
    </DL>
   </LI>
  </OL>



  <P>
   If you have questions and/or answers that should be on the FAQ list
   please send them to <A
   HREF="mailto:squidguard@squidguard.org?subject=SquidGuard%20FAQ?">squidguard@squidguard.org</A>
  </P>


  <BR>
  <HR WIDTH=40%>
  <BR>
  <TABLE ALIGN=CENTER CELLPADDING=3 CELLSPACING=0 BORDER=0>
   <TR>
    <TD ALIGN=CENTER>
     <A HREF="http://www.gnu.org/"><IMG
     SRC="http://info.ost.eltele.no/icons/gnu-logo.gif" BORDER=0
     VALIGN=TOP></A>
    </TD>
    <TD ALIGN=CENTER>
     <A HREF="http://www.perl.com/pub/"><IMG
     SRC="http://info.ost.eltele.no/icons/perl-logo.gif" BORDER=0
     VALIGN=TOP></A>
    </TD>
    <TD ALIGN=CENTER>
     <A HREF="http://www.sun.com/solaris/"><IMG
     SRC="http://info.ost.eltele.no/icons/solaris-logo.gif" BORDER=0
     VALIGN=BOTTOM></A>
    </TD>
    <TD ALIGN=CENTER>
     <A HREF="http://www.sun.com/servers/"><IMG
     SRC="http://info.ost.eltele.no/icons/sun-logo.gif" BORDER=0
     VALIGN=BOTTOM></A>
    </TD>
    <TD ALIGN=CENTER>
     <A HREF="http://www.ost.eltele.no/"><IMG
      SRC="http://info.ost.eltele.no/icons/eltele-logo.gif" BORDER=0
      VALIGN=BOTTOM></A>
    </TD>
   </TR>
  </TABLE>
  <TABLE ALIGN=CENTER CELLPADDING=3 CELLSPACING=0 BORDER=0>
   <TR>
    <TD ALIGN=CENTER>
     <A HREF="http://www.apache.org/httpd.html"><IMG
     SRC="http://info.ost.eltele.no/icons/apache-logo.gif" BORDER=0
     VALIGN=BOTTOM></A>
    </TD>
    <TD ALIGN=CENTER>
     <A HREF="http://www.squid-cache.org/"><IMG
     SRC="http://info.ost.eltele.no/icons/squid-logo.gif" BORDER=0
     VALIGN=BOTTOM></A>
    </TD>
    <TD ALIGN=CENTER>
     <A HREF="http://www.squidguard.org/"><IMG
     SRC="http://info.ost.eltele.no/freeware/squidGuard/squidGuard.gif"
     BORDER=0 VALIGN=BOTTOM></A>
    </TD>
   </TR>
  </TABLE>
  <TABLE ALIGN=CENTER CELLPADDING=3 CELLSPACING=0 BORDER=0>
   <TR>
    <TD ALIGN=CENTER>
     <A HREF="http://info.ost.eltele.no/freeware/identd/"><IMG
     SRC="http://info.ost.eltele.no/freeware/identd/identd.gif"
     BORDER=0 VALIGN=BOTTOM></A>
    </TD>
   </TR>
  </TABLE>


 </BODY>
</HTML>