# dbab(8) -- dnsmasq based ad blocking

## SYNOPSIS

    # start dbab-svr server
	/etc/init.d/dbab start

    # stop dbab-svr server
	/etc/init.d/dbab stop

    # get/update ad blocking list
	/usr/sbin/dbab-get-list

	# add your own to the ad blocking list
	/usr/sbin/dbab-add-list


## DESCRIPTION

dbab provides a total solution for SOHO service environment, smoothly integrates DHCP, DNS, local caching and Ad blocking into harmony.
Ad blocking is done by DNSmasq + Pixelserv, i.e., done at the DNS level -- all requests to ad-sites are blocked right there at DNS. No more user space extensive pattern matching necessary at all. Work for your mobile devices as well. You don't need to install anything to your mobile devices to enjoy the ad-free and speed-up browsing.


## ALTERNATIVES

People may also use browsers' adblock-plus extension to block ads, but fewer think over how it works internally. Here is an overview of Adblock Plus from a thousand mile high [1] -- whenever the browser needs to load something, the extension kicks in and do a thorough pattern matching of all known ad urls using regular expressions, then hectically replace all found ad urls with something else. This is done on every page, every load, and every component of the web page, using JavaScript. Thus it is by nature slow and CPU intensive, at least inefficient. There are other alternatives to this, e.g., privoxy, but the concepts are the same.

[1] http://adblockplus.org/en/faq_internal

## ADVANTAGES

Comparing to other ad-blocking efforts, `dbab` will be super light. Only a few operations are enough to determine and stop the ads. No heavy-lifting (using CPU intensive URL pattern matching) necessary. Thus it will be lighting fast as well. 

The advantages of using `dbab` are:

- **Work at the DNS level**. Leave the web pages intact, without any pattern matching, string substitution, and/or html elements replacing.
- **Work for your mobile devices as well**. Were you previously in the dilemma of choosing ads free or slow response for your mobile devices (iphone, ipad, etc)? Now you don't. You don't need to install any thing to your mobile devices for them to enjoy the ad-free browsing experience. Moreover, their browsing speed will increase dramatically on revisited pages/images. 
- **Serve instantly**. All ads will be replaced by a 1x1 pixel gif image served locally by the `dbab-svr` server.
- **Maintenance free**. You don't need to maintain the list of ad sites yourself. The block list can be downloaded from pgl.yoyo.org periodically. If you don't like some of the entries there, you can add-to or remove-from that list easily. 

## DBAB-SVR

The `dbab-svr` is a super minimal web server / pixelserv, it has one purpose of serving a 1x1 pixel transparent gif file. It can optionally provide the automatic WPAD service as well if so configured. By default it listens on localhost. 

## DBAB-GET-LIST

The `dbab-get-list` is used to get dnsmasq blocking list from pgl.yoyo.org to be used by DNSmasq. The result is stored as `/etc/dnsmasq.d/dnsmasq.adblock.conf`.

You can run it once, or put it in a cron job so as to update the block list periodically. E.g., to update on a weekly basis:

    ln -s /usr/sbin/dbab-get-list /etc/cron.weekly/

## DBAB-ADD-LIST

You can use `dbab-add-list` to add your own entries to `dnsmasq` blocking list, if the list from pgl.yoyo.org is not sufficient for you. The result is stored as `/etc/dnsmasq.d/dnsmasq.trashsites.conf`.

## DBAB-CHK-LIST

The `dbab-chk-list` can help you to check if your own list is already covered by pgl.yoyo.org.

## DHCP-ADD-WPAD

he `dhcp-add-wpad` will take the content in `/etc/dbab.proxy` as the host name of the squid caching server, as well as taking the content in `/etc/dbab.addr` as
the IP address of `dhcp` server, then enable the automatic WPAD service within the system, with the help of the DNS and DHCP server. 

## FILES 

* /etc/dbab.addr:  
  The IP address that `dbab-svr` listens on. Defaults to localhost.
  
* /etc/dbab.list-:  
  The entries you want to filter out from the pgl.yoyo.org lists. List sites you still wish to visit there. 

* /etc/dbab.list+:  
  The entries you want to add to blocking list on top of the pgl.yoyo.org list, used by `dbab-add-list`. 

* /etc/dbab.proxy:  
  The name or IP address of your squid caching server. Defaults to localhost.
  
* /usr/share/doc/dbab/dbab.html:  
  The more detailed introduction and installation guild.
  

## AUTHOR

Copyright: 2013~2014 Tong Sun `suntong001 at users.sourceforge.net`  
License: BSD-3-Clause

The pixelserv was originally downloaded from  
 http://proxytunnel.sourceforge.net/files/pixelserv.pl.txt  
Wrote by Piet Wintjens, with BSD (no advertising clause) license.
