[squid-users] Ad-zapping redirector causes IE to think it never completes loading a page

Hi everyone,

I am running Squid 2.5STABLE5 and trying to block a few of the more
prominent web advertisements that chew bandwidth. The way I have tried
to set this up is with i) two acls to match advert objects - one a
dstdomain and one a url_regex ii) a short perl redirector which
redirects requests for these ad objects to a 1x1 transparent gif hosted
on a local server.

This seems to be working to a point. The problem I am experiencing is
that many (but not all) pages which have ads that get redirected load ok
but Internet Explorer browsers never think the page has completed
loading. It sits there with the IE icon whirling around and 'Opening
page http://requested.address.com' in the status bar. This doesn't
prevent users from viewing their pages, but it is annoying. Prior to
using the redirector I just denied and TCP_RESET the requests which
matched the advert acls using deny_info - this did not cause the
continuous loading behaviour that we are experiecing with the
redirector.

Should I be appending the newline character at the end of the redirected
URL (see code below)? Is there anything else wrong with the redirector
code? How do I prevent this continuously loading page behaviour?

Initially I was trying to redirect to an image which I hosted within the
squid-internet-static area. This was causing cache.log to fill up with
forwarding loop warnings. I realise that it is indeed forwarding back
to itself but think that this should be allowed for internal-static
objects. Is there a way to get rid of the warnings? In the meantime
the GIF is now hosted on an internal webserver.

---- Appropriate lines of squid.conf ----
acl denied_advert_domains dstdomain -i
"/usr/local/squid/etc/denied_advert_domains"
acl denied_advert_urls url_regex -i
"/usr/local/squid/etc/denied_advert_urls"
redirect_program /usr/local/squid/bin/ad_redir.pl
redirect_children 5
redirector_access allow denied_advert_domains
redirector_access allow denied_advert_urls
redirector_access deny all
---- End squid.conf lines ----

---- Redirector program ad_redir.pl ----
#!/usr/bin/perl
$|=1;
while (<>) {
  print "http://host.domain.com/1x1transgif.gif\n"
}
---- End of program ----

Thanks for any help that is provided.

Regards,
Ken.
Received on Tue Oct 26 2004 - 00:10:53 MDT