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App::DNS::Adblock - A lightweight DNS ad filter


version 0.015


This is an ad filter for use in a local area network. Its function is to load lists of ad domains and answer DNS queries for those domains with a loopback address. Any other DNS queries are forwarded upstream, either to a specified list of nameservers or to those listed in /etc/resolv.conf.

The module loads externally maintained lists of ad hosts intended for use by the adblock plus Firefox extension. Use of the lists focuses only on third-party listings that define dedicated advertising and tracking hosts.

A custom blacklist and/or whitelist can also be loaded. In this case, host listings must conform to a one host per line format.

Once running, local network dns queries can be addressed to the host's ip.


    my $adfilter = App::DNS::Adblock->new();


Without any parameters, the module will function simply as a proxy, forwarding all requests upstream to predefined nameservers.



    my $adfilter = App::DNS::Adblock->new(

        adblock_stack => [
            url => '[day]=&startdate[month]=&startdate[year]=&mimetype=plaintext',
            path => '/var/named/pgl-adblock.txt',     #path to ad hosts
            refresh => 7,                             #refresh value in days (default = 7)

            url => 'abp:subscribe?';
            path => '/var/named/easyprivacy.txt',
            refresh => 5,

The adblock_stack arrayref encloses one or more hashrefs composed of three parameters: a url that returns a list of ad hosts in adblock plus format; a path string that defines where the module will write a local copy of the list; a refresh value that determines what age (in days) the local copy may be before it is refreshed.

A collection of lists is available at The module will accept standard or abp:subscribe? urls. You can cut and paste encoded links directly.


    my $adfilter = App::DNS::Adblock->new(
        blacklist => '/var/named/blacklist',  #path to secondary hosts

A path string that defines where the module will access a local list of ad hosts. A single column is the only acceptable format:

    # ad nauseam


    my $adfilter = App::DNS::Adblock->new(

        whitelist => '/var/named/whitelist',  #path to exclusions

A path string to a single column list of hosts. These hosts will be removed from the filter.

host, port

    my $adfilter = App::DNS::Adblock->new( host => $host, port => $port );

The IP address to bind to. If not defined, the server attempts binding to the local ip. The default port is 53.

forwarders, forwarders_port

    my $adfilter = App::DNS::Adblock->new( forwarders => [ nameserver, ], forwarders_port => $port );

An arrayref of one or more nameservers to forward any DNS queries to. Defaults to nameservers listed in /etc/resolv.conf. The default port is 53. Windows machines should define a forwarder to avoid the default behavior.


    my $adfilter = App::DNS::Adblock->new( setdns  => '1' ); #defaults to '0'

If set, the module attempts to set local dns settings to the host's ip. This may or may not work if there are multiple active interfaces. You may need to manually adjust your local dns settings.


    my $adfilter = App::DNS::Adblock->new( loopback  => '' ); #defaults to ''

If set, the nameserver will return this address rather than the standard loopback address.


    my $adfilter = App::DNS::Adblock->new( debug => '1' ); #defaults to '0'

The debug option logs actions to stdout and can be set from 1-3 with increasing output: the module will feedback (1) logging, (2) nameserver logging, and (3) resolver logging.


Tested under darwin only.


David Watson <>


scripts/ in the distribution

This module is essentially a lightweight, non-Moose version of Net::DNS::Dynamic::Adfilter


This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.

The full text of the license can be found in the LICENSE file included with this module.