<!entity history SYSTEM "history.sgml">
<!entity copyright SYSTEM "copyright.sgml">
<!entity license SYSTEM "license.sgml">
+<!entity GPLv2 SYSTEM "../../LICENSE">
<!entity p-authors SYSTEM "p-authors.sgml">
<!entity config SYSTEM "p-config.sgml">
-<!entity p-version "3.0.18">
+<!entity changelog SYSTEM "changelog.sgml">
+<!entity p-version "3.0.27">
<!entity p-status "UNRELEASED">
<!entity % p-authors-formal "INCLUDE"> <!-- include additional text, etc -->
<!entity % p-not-stable "INCLUDE">
This file belongs into
ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
- $Id: user-manual.sgml,v 2.135 2011/09/04 11:10:12 fabiankeil Exp $
+ $Id: user-manual.sgml,v 2.219 2017/04/20 11:11:43 fabiankeil Exp $
- Copyright (C) 2001-2011 Privoxy Developers http://www.privoxy.org/
+ Copyright (C) 2001-2017 Privoxy Developers https://www.privoxy.org/
See LICENSE.
========================================================================
<subscript>
<!-- Completely the wrong markup, but very little is allowed -->
<!-- in this part of an article. FIXME -->
- <link linkend="copyright">Copyright</link> &my-copy; 2001-2011 by
- <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
+ <link linkend="copyright">Copyright</link> &my-copy; 2001-2017 by
+ <ulink url="https://www.privoxy.org/">Privoxy Developers</ulink>
</subscript>
</pubdate>
-<pubdate>$Id: user-manual.sgml,v 2.135 2011/09/04 11:10:12 fabiankeil Exp $</pubdate>
+<pubdate>$Id: user-manual.sgml,v 2.219 2017/04/20 11:11:43 fabiankeil Exp $</pubdate>
<!--
<para>
The <citetitle>Privoxy User Manual</citetitle> gives users information on how to
install, configure and use <ulink
- url="http://www.privoxy.org/">Privoxy</ulink>.
+ url="https://www.privoxy.org/">Privoxy</ulink>.
</para>
<!-- Include privoxy.sgml boilerplate: -->
<para>
You can find the latest version of the <citetitle>Privoxy User Manual</citetitle> at <ulink
- url="http://www.privoxy.org/user-manual/">http://www.privoxy.org/user-manual/</ulink>.
+ url="https://www.privoxy.org/user-manual/">https://www.privoxy.org/user-manual/</ulink>.
Please see the <link linkend="contact">Contact section</link> on how to
contact the developers.
</para>
-<!-- <para> -->
-<!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
-<!-- </para> -->
</abstract>
</artheader>
<sect1 label="1" id="introduction"><title>Introduction</title>
<para>
This documentation is included with the current &p-status; version of
- <application>Privoxy</application>, v.&p-version;<![%p-not-stable;[,
+ <application>Privoxy</application>, &p-version;<![%p-not-stable;[,
and is mostly complete at this point. The most up to date reference for the
time being is still the comments in the source files and in the individual
configuration files. Development of a new version is currently nearing
<application>Privoxy</application> is available both in convenient pre-compiled
packages for a wide range of operating systems, and as raw source code.
For most users, we recommend using the packages, which can be downloaded from our
- <ulink url="http://sourceforge.net/projects/ijbswa/">Privoxy Project
+ <ulink url="https://sourceforge.net/projects/ijbswa/">Privoxy Project
Page</ulink>.
</para>
<!-- XXX: The installation sections should be sorted -->
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 id="installation-pack-rpm"><title>Red Hat and Fedora RPMs</title>
-
-<para>
- RPMs can be installed with <literal>rpm -Uvh privoxy-&p-version;-1.rpm</literal>,
- and will use <filename>/etc/privoxy</filename> for the location
- of configuration files.
-</para>
-
-<para>
- Note that on Red Hat, <application>Privoxy</application> will
- <emphasis>not</emphasis> be automatically started on system boot. You will
- need to enable that using <command>chkconfig</command>,
- <command>ntsysv</command>, or similar methods.
-</para>
-
-<para>
- If you have problems with failed dependencies, try rebuilding the SRC RPM:
- <literal>rpm --rebuild privoxy-&p-version;-1.src.rpm</literal>. This
- will use your locally installed libraries and RPM version.
-</para>
-
-<para>
- Also note that if you have a <application>Junkbuster</application> RPM installed
- on your system, you need to remove it first, because the packages conflict.
- Otherwise, RPM will try to remove <application>Junkbuster</application>
- automatically if found, before installing <application>Privoxy</application>.
-</para>
-</sect3>
-
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-deb"><title>Debian and Ubuntu</title>
<para>
</sect3>
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 id="installation-pack-bintgz"><title>Solaris <!--, NetBSD, HP-UX--></title>
-
-<para>
- Create a new directory, <literal>cd</literal> to it, then unzip and
- untar the archive. For the most part, you'll have to figure out where
- things go. <!-- FIXME, more info needed? -->
-</para>
-</sect3>
-
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-os2"><title>OS/2</title>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-mac"><title>Mac OS X</title>
<para>
- Unzip the downloaded file (you can either double-click on the zip file
- icon from the Finder, or from the desktop if you downloaded it there).
- Then, double-click on the package installer icon and follow the
- installation process.
+ Installation instructions for the OS X platform depend upon whether
+ you downloaded a ready-built installation package (.pkg or .mpkg) or have
+ downloaded the source code.
</para>
+</sect3>
+<sect3 renderas="sect4" id="OS-X-install-from-package">
+<title>Installation from ready-built package</title>
<para>
- The privoxy service will automatically start after a successful
- installation (in addition to every time your computer starts up). To
- prevent the privoxy service from automatically starting when your
- computer starts up, remove or rename the folder named
- <literal>/Library/StartupItems/Privoxy</literal>.
+ The downloaded file will either be a .pkg (for OS X 10.5 upwards) or a bzipped
+ .mpkg file (for OS X 10.4). The former can be double-clicked as is and the
+ installation will start; double-clicking the latter will unzip the .mpkg file
+ which can then be double-clicked to commence the installation.
</para>
<para>
- To manually start or stop the privoxy service, use the Privoxy Utility
- for Mac OS X. This application controls the privoxy service (e.g.
- starting and stopping the service as well as uninstalling the software).
+ The privoxy service will automatically start after a successful installation
+ (and thereafter every time your computer starts up) however you will need to
+ configure your web browser(s) to use it. To do so, configure them to use a
+ proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
+</para>
+<para>
+ To prevent the privoxy service from automatically starting when your computer
+ starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
+ (on OS X 10.5 and higher) or the folder named
+ <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
</para>
-</sect3>
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 id="installation-amiga"><title>AmigaOS</title>
<para>
- Copy and then unpack the <filename>lha</filename> archive to a suitable location.
- All necessary files will be installed into <application>Privoxy</application>
- directory, including all configuration and log files. To uninstall, just
- remove this directory.
+ To manually start or stop the privoxy service, use the scripts startPrivoxy.sh
+ and stopPrivoxy.sh supplied in /Applications/Privoxy. They must be run from an
+ administrator account, using sudo.
+</para>
+<para>
+ To uninstall, run /Applications/Privoxy/uninstall.command as sudo from an
+ administrator account.
</para>
</sect3>
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 id="installation-tbz"><title>FreeBSD</title>
-
+<sect3 renderas="sect4" id="OS-X-install-from-source">
+<title>Installation from source</title>
<para>
- Privoxy is part of FreeBSD's Ports Collection, you can build and install
- it with <literal>cd /usr/ports/www/privoxy; make install clean</literal>.
+ To build and install the Privoxy source code on OS X you will need to obtain
+ the macsetup module from the Privoxy Sourceforge CVS repository (refer to
+ Sourceforge help for details of how to set up a CVS client to have read-only
+ access to the repository). This module contains scripts that leverage the usual
+ open-source tools (available as part of Apple's free of charge Xcode
+ distribution or via the usual open-source software package managers for OS X
+ (MacPorts, Homebrew, Fink etc.) to build and then install the privoxy binary
+ and associated files. The macsetup module's README file contains complete
+ instructions for its use.
</para>
<para>
- If you don't use the ports, you can fetch and install
- the package with <literal>pkg_add -r privoxy</literal>.
+ The privoxy service will automatically start after a successful installation
+ (and thereafter every time your computer starts up) however you will need to
+ configure your web browser(s) to use it. To do so, configure them to use a
+ proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
</para>
<para>
- The port skeleton and the package can also be downloaded from the
- <ulink url="https://sourceforge.net/project/showfiles.php?group_id=11118">File Release
- Page</ulink>, but there's no reason to use them unless you're interested in the
- beta releases which are only available there.
+ To prevent the privoxy service from automatically starting when your computer
+ starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
+ (on OS X 10.5 and higher) or the folder named
+ <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
</para>
-</sect3>
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 id="installattion-gentoo"><title>Gentoo</title>
<para>
- Gentoo source packages (Ebuilds) for <application>Privoxy</application> are
- contained in the Gentoo Portage Tree (they are not on the download page,
- but there is a Gentoo section, where you can see when a new
- <application>Privoxy</application> Version is added to the Portage Tree).
+ To manually start or stop the privoxy service, use the Privoxy Utility
+ for Mac OS X (also part of the macsetup module). This application can start
+ and stop the privoxy service and display its log and configuration files.
</para>
<para>
- Before installing <application>Privoxy</application> under Gentoo just do
- first <literal>emerge --sync</literal> to get the latest changes from the
- Portage tree. With <literal>emerge privoxy</literal> you install the latest
- version.
+ To uninstall, run the macsetup module's uninstall.sh as sudo from an
+ administrator account.
</para>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 id="installation-freebsd"><title>FreeBSD</title>
+
<para>
- Configuration files are in <filename>/etc/privoxy</filename>, the
- documentation is in <filename>/usr/share/doc/privoxy-&p-version;</filename>
- and the Log directory is in <filename>/var/log/privoxy</filename>.
+ Privoxy is part of FreeBSD's Ports Collection, you can build and install
+ it with <literal>cd /usr/ports/www/privoxy; make install clean</literal>.
</para>
</sect3>
<para>
The most convenient way to obtain the <application>Privoxy</application> sources
is to download the source tarball from our
- <ulink url="http://sourceforge.net/project/showfiles.php?group_id=11118&package_id=10571">project download
+ <ulink url="https://sourceforge.net/projects/ijbswa/files/Sources/">project download
page</ulink>.
</para>
<para>
If you like to live on the bleeding edge and are not afraid of using
possibly unstable development versions, you can check out the up-to-the-minute
- version directly from <ulink url="http://sourceforge.net/cvs/?group_id=11118">the
+ version directly from <ulink url="https://sourceforge.net/p/ijbswa/code/?source=navbar">the
CVS repository</ulink>.
<!--
deprecated...out of business.
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="installation-keepupdated"><title>Keeping your Installation Up-to-Date</title>
-<para>
- As user feedback comes in and development continues, we will make updated versions
- of both the main <link linkend="actions-file">actions file</link> (as a <ulink
- url="http://sourceforge.net/project/showfiles.php?group_id=11118&release_id=103670">separate
- package</ulink>) and the software itself (including the actions file) available for
- download.
-</para>
<para>
If you wish to receive an email notification whenever we release updates of
<application>Privoxy</application> or the actions file, <ulink
- url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
- to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
+ url="https://lists.privoxy.org/mailman/listinfo/privoxy-announce">subscribe
+ to our announce mailing list</ulink>, privoxy-announce@lists.privoxy.org.
</para>
<para>
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="whatsnew">
<title>What's New in this Release</title>
+
+&changelog;
+
+<!-- ~~~~~ New section ~~~~~ -->
+
+<sect2 id="upgradersnote">
+<title>Note to Upgraders</title>
+
<para>
- <application>Privoxy 3.0.17</application> is a stable release.
- The changes since 3.0.16 stable are:
+ A quick list of things to be aware of before upgrading from earlier
+ versions of <application>Privoxy</application>:
</para>
<para>
<itemizedlist>
- <listitem>
- <para>
- Fixed last-chunk-detection for responses where the content was small
- enough to be read with the body, causing Privoxy to wait for the
- end of the content until the server closed the connection or the
- request timed out. Reported by "Karsten" in #3028326.
- </para>
- </listitem>
- <listitem>
- <para>
- Responses with status code 204 weren't properly detected as body-less
- like RFC2616 mandates. Like the previous bug, this caused Privoxy to
- wait for the end of the content until the server closed the connection
- or the request timed out. Fixes #3022042 and #3025553, reported by a
- user with no visible name. Most likely also fixes a bunch of other
- AJAX-related problem reports that got closed in the past due to
- insufficient information and lack of feedback.
- </para>
- </listitem>
- <listitem>
- <para>
- Fixed an ACL bug that made it impossible to build a blacklist.
- Usually the ACL directives are used in a whitelist, which worked
- as expected, but blacklisting is still useful for public proxies
- where one only needs to deny known abusers access.
- </para>
- </listitem>
- <listitem>
- <para>
- Added LOG_LEVEL_RECEIVED to log the not-yet-parsed data read from the
- network. This should make debugging various parsing issues a lot easier.
- </para>
- </listitem>
- <listitem>
- <para>
- The IPv6 code is enabled by default on Windows versions that support it.
- Patch submitted by oCameLo in #2942729.
- </para>
- </listitem>
- <listitem>
- <para>
- In mingw32 versions, the user.filter file is reachable through the
- GUI, just like default.filter is. Feature request 3040263.
- </para>
+
+ <listitem>
+ <para>
+ The recommended way to upgrade &my-app; is to backup your old
+ configuration files, install the new ones, verify that &my-app;
+ is working correctly and finally merge back your changes using
+ <application>diff</application> and maybe <application>patch</application>.
+ </para>
+ <para>
+ There are a number of new features in each &my-app; release and
+ most of them have to be explicitly enabled in the configuration
+ files. Old configuration files obviously don't do that and due
+ to syntax changes using old configuration files with a new
+ &my-app; isn't always possible anyway.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Note that some installers remove earlier versions completely,
+ including configuration files, therefore you should really save
+ any important configuration files!
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ On the other hand, other installers don't overwrite existing configuration
+ files, thinking you will want to do that yourself.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ In the default configuration only fatal errors are logged now.
+ You can change that in the <link linkend="DEBUG">debug section</link>
+ of the configuration file. You may also want to enable more verbose
+ logging until you verified that the new &my-app; version is working
+ as expected.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ Three other config file settings are now off by default:
+ <link linkend="enable-remote-toggle">enable-remote-toggle</link>,
+ <link linkend="enable-remote-http-toggle">enable-remote-http-toggle</link>,
+ and <link linkend="enable-edit-actions">enable-edit-actions</link>.
+ If you use or want these, you will need to explicitly enable them, and
+ be aware of the security issues involved.
+ </para>
</listitem>
+
+<!--
+ <listitem>
+ <para>
+ What constitutes a <quote>default</quote> configuration has changed,
+ and you may want to review which actions are <quote>on</quote> by
+ default. This is primarily a matter of emphasis, but some features
+ you may have been used to, may now be <quote>off</quote> by default.
+ There are also a number of new actions and filters you may want to
+ consider, most of which are not fully incorporated into the default
+ settings as yet (see above).
+ </para>
+ </listitem>
+-->
+<!--
<listitem>
<para>
- Added the configure option --enable-large-file-support to set a few
- defines that are required by platforms like GNU/Linux to support files
- larger then 2GB. Mainly interesting for users without proper logfile
- management.
+ The default actions setting is now <literal>Cautious</literal>. Previous
+ releases had a default setting of <literal>Medium</literal>. Experienced
+ users may want to adjust this, as it is fairly conservative by &my-app;
+ standards and past practices. See <ulink
+ url="http://config.privoxy.org/edit-actions-list?f=default">
+ http://config.privoxy.org/edit-actions-list?f=default</ulink>. New users
+ should try the default settings for a while before turning up the volume.
</para>
</listitem>
+
<listitem>
<para>
- Logging with "debug 16" no longer stops at the first nul byte which is
- pretty useless. Non-printable characters are replaced with their hex value
- so the result can't span multiple lines making parsing them harder then
- necessary.
+ The default setting has filtering turned <emphasis>off</emphasis>, which
+ subsequently means that compression is <emphasis>on</emphasis>. Remember
+ that filtering does not work on compressed pages, so if you use, or want to
+ use, filtering, you will need to force compression off. Example:
</para>
- </listitem>
- <listitem>
<para>
- Privoxy logs when reading an action, filter or trust file.
+ <screen>
+ { +<link linkend="filter">filter</link>{google} +<link linkend="prevent-compression">prevent-compression</link> }
+ .google.</screen>
</para>
- </listitem>
- <listitem>
<para>
- Fixed incorrect regression test markup which caused a test in
- 3.0.16 to fail while Privoxy itself was working correctly.
- While Privoxy accepts hide-referer, too, the action name is actually
- hide-referrer which is also the name used one the final results page,
- where the test expected the alias.
+ Or if you use a number of filters, or filter many sites, you may just want
+ to turn off compression for all sites in
+ <filename>default.action</filename> (or
+ <filename>user.action</filename>).
</para>
+
</listitem>
+
<listitem>
- <para>
- CGI interface improvements:
- <itemizedlist>
- <listitem>
- <para>
- In finish_http_response(), continue to add the 'Connection: close'
- header if the client connection will not be kept alive.
- Anonymously pointed out in #2987454.
- </para>
- </listitem>
- <listitem>
- <para>
- Apostrophes in block messages no longer cause parse errors
- when the blocked page is viewed with JavaScript enabled.
- Reported by dg1727 in #3062296.
- </para>
- </listitem>
- <listitem>
- <para>
- Fix a bunch of anchors that used underscores instead of dashes.
- </para>
- </listitem>
- <listitem>
- <para>
- Allow to keep the client connection alive after crunching the previous request.
- Already opened server connections can be kept alive, too.
- </para>
- </listitem>
- <listitem>
- <para>
- In cgi_show_url_info(), don't forget to prefix URLs that only contain
- http:// or https:// in the path. Fixes #2975765 reported by Adam Piggott.
- </para>
- </listitem>
- <listitem>
- <para>
- Show the 404 CGI page if cgi_send_user_manual() is called while
- local user manual delivery is disabled.
- </para>
- </listitem>
- </itemizedlist>
- </para>
+ <para>
+ Also, <link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> is
+ off by default now. If you've liked this feature in the past, you may want
+ to turn it back on in <filename>user.action</filename> now.
+ </para>
</listitem>
+
+
<listitem>
- <para>
- Action file improvements:
- <itemizedlist>
- <listitem>
- <para>
- Enable user.filter by default. Suggested by David White in #3001830.
- </para>
- </listitem>
- <listitem>
- <para>
- Block .sitestat.com/. Reported by johnd16 in #3002725.
- </para>
- </listitem>
- <listitem>
- <para>
- Block .atemda.com/. Reported by johnd16 in #3002723.
- </para>
- </listitem>
- <listitem>
- <para>
- Block js.adlink.net/. Reported by johnd16 in #3002720.
- </para>
- </listitem>
- <listitem>
- <para>
- Block .analytics.yahoo.com/. Reported by johnd16 in #3002713.
- </para>
- </listitem>
- <listitem>
- <para>
- Block sb.scorecardresearch.com, too. Reported by dg1727 in #2992652.
- </para>
- </listitem>
- <listitem>
- <para>
- Fix problems noticed on Yahoo mail and news pages.
- </para>
- </listitem>
- <listitem>
- <para>
- Remove the too broad yahoo section, only keeping the
- fast-redirects exception as discussed on ijbswa-devel@.
- </para>
- </listitem>
- <listitem>
- <para>
- Don't block adesklets.sourceforge.net. Reported in #2974204.
- </para>
- </listitem>
- <listitem>
- <para>
- Block chartbeat ping tracking. Reported in #2975895.
- </para>
- </listitem>
- <listitem>
- <para>
- Tag CSS and image requests with cautious and medium settings, too.
- </para>
- </listitem>
- <listitem>
- <para>
- Don't handle view.atdmt.com as image. It's used for click-throughs
- so users should be able to "go there anyway".
- Reported by Adam Piggott in #2975927.
- </para>
- </listitem>
- <listitem>
- <para>
- Also let the refresh-tags filter remove invalid refresh tags where
- the 'url=' part is missing. Anonymously reported in #2986382.
- While at it, update the description to mention the fact that only
- refresh tags with refresh times above 9 seconds are covered.
- </para>
- </listitem>
- <listitem>
- <para>
- javascript needs to be blocked with +handle-as-empty-document to
- work around Firefox bug 492459. So move .js blockers from
- +block{Might be a web-bug.} -handle-as-empty-document to
- +block{Might be a web-bug.} +handle-as-empty-document.
- </para>
- </listitem>
- <listitem>
- <para>
- ijbswa-Feature Requests-3006719 - Block 160x578 Banners.
- </para>
- </listitem>
- <listitem>
- <para>
- Block another omniture tracking domain.
- </para>
- </listitem>
- <listitem>
- <para>
- Added a range-requests tagger.
- </para>
- </listitem>
- <listitem>
- <para>
- Added two sections to get Flickr's Ajax interface working with
- default pre-settings. If you change the configuration to block
- cookies by default, you'll need additional exceptions.
- Reported by Mathias Homann in #3101419 and by Patrick on ijbswa-users@.
- </para>
- </listitem>
- </itemizedlist>
- </para>
- </listitem>
- <listitem>
- <para>
- Documentation improvements:
- <itemizedlist>
- <listitem>
- <para>
- Explicitly mention how to match all URLs.
- </para>
- </listitem>
- <listitem>
- <para>
- Consistently recommend socks5 in the Tor FAQ entry and mention
- its advantage compared to socks4a. Reported by David in #2960129.
- </para>
- </listitem>
- <listitem>
- <para>
- Slightly improve the explanation of why filtering may appear
- slower than it is.
- </para>
- </listitem>
- <listitem>
- <para>
- Grammar fixes for the ACL section.
- </para>
- </listitem>
- <listitem>
- <para>
- Fixed a link to the 'intercepting' entry and add another one.
- </para>
- </listitem>
- <listitem>
- <para>
- Rename the 'Other' section to 'Mailing Lists' and reword it
- to make it clear that nobody is forced to use the trackers
- </para>
- </listitem>
- <listitem>
- <para>
- Note that 'anonymously' posting on the trackers may not always
- be possible.
- </para>
- </listitem>
- <listitem>
- <para>
- Suggest to enable debug 32768 when suspecting parsing problems.
- </para>
- </listitem>
- </itemizedlist>
- </para>
- </listitem>
- <listitem>
- <para>
- Privoxy-Log-Parser improvements:
- <itemizedlist>
- <listitem>
- <para>
- Gather statistics for ressources, methods, and HTTP versions
- used by the client.
- </para>
- </listitem>
- <listitem>
- <para>
- Also gather statistics for blocked and redirected requests.
- </para>
- </listitem>
- <listitem>
- <para>
- Provide the percentage of keep-alive offers the client accepted.
- </para>
- </listitem>
- <listitem>
- <para>
- Add a --url-statistics-threshold option.
- </para>
- </listitem>
- <listitem>
- <para>
- Add a --host-statistics-threshold option to also gather
- statistics about how many request where made per host.
- </para>
- </listitem>
- <listitem>
- <para>
- Fix a bug in handle_loglevel_header() where a 'scan: ' got lost.
- </para>
- </listitem>
- <listitem>
- <para>
- Add a --shorten-thread-ids option to replace the thread id with
- a decimal number.
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and ignore: Looks like we got the last chunk together
- with the server headers. We better stop reading.
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and ignore: Continue hack in da house.
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and higlight: Rejecting connection from 10.0.0.2.
- Maximum number of connections reached.
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and highlight: Loading actions file: /usr/local/etc/privoxy/default.action
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and highlight: Loading filter file: /usr/local/etc/privoxy/default.filter
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and highlight: Killed all-caps Host header line: HOST: bestproxydb.com
- </para>
- </listitem>
- <listitem>
- <para>
- Accept and highlight: Reducing expected bytes to 0. Marking
- the server socket tainted after throwing 4 bytes away.
- </para>
- </listitem>
- <listitem>
- <para>
- Accept: Merged multiple header lines to: 'X-FORWARDED-PROTO: http X-HOST: 127.0.0.1'
- </para>
- </listitem>
- </itemizedlist>
- </para>
- </listitem>
- <listitem>
- <para>
- Code cleanups:
- <itemizedlist>
- <listitem>
- <para>
- Remove the next member from the client_state struct. Only the main
- thread needs access to all client states so give it its own struct.
- </para>
- </listitem>
- <listitem>
- <para>
- Garbage-collect request_contains_null_bytes().
- </para>
- </listitem>
- <listitem>
- <para>
- Ditch redundant code in unload_configfile().
- </para>
- </listitem>
- <listitem>
- <para>
- Ditch LogGetURLUnderCursor() which doesn't seem to be used anywhere.
- </para>
- </listitem>
- <listitem>
- <para>
- In write_socket(), remove the write-only variable write_len in
- an ifdef __OS2__ block. Spotted by cppcheck.
- </para>
- </listitem>
- <listitem>
- <para>
- In connect_to(), don't declare the variable 'flags' on OS/2 where
- it isn't used. Spotted by cppcheck.
- </para>
- </listitem>
- <listitem>
- <para>
- Limit the scope of various variables. Spotted by cppcheck.
- </para>
- </listitem>
- <listitem>
- <para>
- In add_to_iob(), turn an interestingly looking for loop into a
- boring while loop.
- </para>
- </listitem>
- <listitem>
- <para>
- Code cleanup in preparation for external filters.
- </para>
- </listitem>
- <listitem>
- <para>
- In listen_loop(), mention the socket on which we accepted the
- connection, not just the source IP address.
- </para>
- </listitem>
- <listitem>
- <para>
- In write_socket(), also log the socket we're writing to.
- </para>
- </listitem>
- <listitem>
- <para>
- In log_error(), assert that escaped characters get logged
- completely or not at all.
- </para>
- </listitem>
- <listitem>
- <para>
- In log_error(), assert that ival and sval have reasonable values.
- There's no reason not to abort() if they don't.
- </para>
- </listitem>
- <listitem>
- <para>
- Remove an incorrect cgi_error_unknown() call in a
- cannot-happen-situation in send_crunch_response().
- </para>
- </listitem>
- <listitem>
- <para>
- Clean up white-space in http_response definition and
- move the crunch_reason to the beginning.
- </para>
- </listitem>
- <listitem>
- <para>
- Turn http_response.reason into an enum and rename it
- to http_response.crunch_reason.
- </para>
- </listitem>
- <listitem>
- <para>
- Silence a 'gcc (Debian 4.3.2-1.1) 4.3.2' warning on i686 GNU/Linux.
- </para>
- </listitem>
- <listitem>
- <para>
- Fix white-space in a log message in remove_chunked_transfer_coding().
- While at it, add a note that the message doesn't seem to
- be entirely correct and should be improved later on.
- </para>
- </listitem>
- </itemizedlist>
- </para>
- </listitem>
- <listitem>
- <para>
- GNUmakefile improvements:
- <itemizedlist>
- <listitem>
- <para>
- Use $(SSH) instead of ssh, so one only needs to specify a username once.
- </para>
- </listitem>
- <listitem>
- <para>
- Removed references to the action feedback thingy that hasn't been
- working for years.
- </para>
- </listitem>
- <listitem>
- <para>
- Consistently use shell.sourceforge.net instead of shell.sf.net so
- one doesn't need to check server fingerprints twice.
- </para>
- </listitem>
- <listitem>
- <para>
- Removed GNUisms in the webserver and webactions targets so they
- work with standard tar.
- </para>
- </listitem>
- </itemizedlist>
- </para>
- </listitem>
+ <para>
+ Some installers may not automatically start
+ <application>Privoxy</application> after installation.
+ </para>
+ </listitem>
+-->
+
</itemizedlist>
</para>
+</sect2>
+</sect1>
<!-- ~~~~~ New section ~~~~~ -->
-
-<sect2 id="upgradersnote">
-<title>Note to Upgraders</title>
-
-<para>
- A quick list of things to be aware of before upgrading from earlier
- versions of <application>Privoxy</application>:
-</para>
-
+<sect1 id="quickstart"><title>Quickstart to Using Privoxy</title>
<para>
<itemizedlist>
<listitem>
<para>
- The recommended way to upgrade &my-app; is to backup your old
- configuration files, install the new ones, verify that &my-app;
- is working correctly and finally merge back your changes using
- <application>diff</application> and maybe <application>patch</application>.
- </para>
- <para>
- There are a number of new features in each &my-app; release and
- most of them have to be explicitly enabled in the configuration
- files. Old configuration files obviously don't do that and due
- to syntax changes using old configuration files with a new
- &my-app; isn't always possible anyway.
- </para>
+ Install <application>Privoxy</application>. See the <link
+ linkend="installation">Installation Section</link> below for platform specific
+ information.
+ </para>
</listitem>
- <listitem>
- <para>
- Note that some installers remove earlier versions completely,
- including configuration files, therefore you should really save
- any important configuration files!
- </para>
- </listitem>
- <listitem>
- <para>
- On the other hand, other installers don't overwrite existing configuration
- files, thinking you will want to do that yourself.
- </para>
- </listitem>
- <listitem>
- <para>
- <filename>standard.action</filename> has been merged into
- the <filename>default.action</filename> file.
- </para>
- </listitem>
- <listitem>
- <para>
- In the default configuration only fatal errors are logged now.
- You can change that in the <link linkend="DEBUG">debug section</link>
- of the configuration file. You may also want to enable more verbose
- logging until you verified that the new &my-app; version is working
- as expected.
- </para>
- </listitem>
-
- <listitem>
- <para>
- Three other config file settings are now off by default:
- <link linkend="enable-remote-toggle">enable-remote-toggle</link>,
- <link linkend="enable-remote-http-toggle">enable-remote-http-toggle</link>,
- and <link linkend="enable-edit-actions">enable-edit-actions</link>.
- If you use or want these, you will need to explicitly enable them, and
- be aware of the security issues involved.
- </para>
- </listitem>
-
-<!--
- <listitem>
- <para>
- What constitutes a <quote>default</quote> configuration has changed,
- and you may want to review which actions are <quote>on</quote> by
- default. This is primarily a matter of emphasis, but some features
- you may have been used to, may now be <quote>off</quote> by default.
- There are also a number of new actions and filters you may want to
- consider, most of which are not fully incorporated into the default
- settings as yet (see above).
- </para>
- </listitem>
--->
-<!--
- <listitem>
- <para>
- The default actions setting is now <literal>Cautious</literal>. Previous
- releases had a default setting of <literal>Medium</literal>. Experienced
- users may want to adjust this, as it is fairly conservative by &my-app;
- standards and past practices. See <ulink
- url="http://config.privoxy.org/edit-actions-list?f=default">
- http://config.privoxy.org/edit-actions-list?f=default</ulink>. New users
- should try the default settings for a while before turning up the volume.
- </para>
- </listitem>
-
- <listitem>
- <para>
- The default setting has filtering turned <emphasis>off</emphasis>, which
- subsequently means that compression is <emphasis>on</emphasis>. Remember
- that filtering does not work on compressed pages, so if you use, or want to
- use, filtering, you will need to force compression off. Example:
- </para>
- <para>
- <screen>
- { +<link linkend="filter">filter</link>{google} +<link linkend="prevent-compression">prevent-compression</link> }
- .google.</screen>
- </para>
- <para>
- Or if you use a number of filters, or filter many sites, you may just want
- to turn off compression for all sites in
- <filename>default.action</filename> (or
- <filename>user.action</filename>).
- </para>
-
- </listitem>
-
- <listitem>
- <para>
- Also, <link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> is
- off by default now. If you've liked this feature in the past, you may want
- to turn it back on in <filename>user.action</filename> now.
- </para>
- </listitem>
-
-
- <listitem>
- <para>
- Some installers may not automatically start
- <application>Privoxy</application> after installation.
- </para>
- </listitem>
--->
-
- </itemizedlist>
-</para>
-
-</sect2>
-</sect1>
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect1 id="quickstart"><title>Quickstart to Using Privoxy</title>
-<para>
- <itemizedlist>
-
- <listitem>
- <para>
- Install <application>Privoxy</application>. See the <link
- linkend="installation">Installation Section</link> below for platform specific
- information.
- </para>
- </listitem>
-
+
<listitem>
<para>
Advanced users and those who want to offer <application>Privoxy</application>
</para>
</listitem>
-<!--
- Did anyone test these lately?
- fk 2007-11-10
- <listitem>
- <para>
- For easy access to &my-app;'s most important controls, drag the provided
- <link linkend="bookmarklets">Bookmarklets</link> into your browser's
- personal toolbar.
- </para>
- </listitem>
--->
-
<listitem>
<para>
Please see the section <link linkend="contact">Contacting the
directory. Except on Win32 where it will try <filename>config.txt</filename>.
</para>
-<sect2 id="start-redhat">
-<title>Red Hat and Fedora</title>
+<sect2 id="start-debian">
+<title>Debian</title>
<para>
- A default Red Hat installation may not start &my-app; upon boot. It will use
- the file <filename>/etc/privoxy/config</filename> as its main configuration
+ We use a script. Note that Debian typically starts &my-app; upon booting per
+ default. It will use the file
+ <filename>/etc/privoxy/config</filename> as its main configuration
file.
</para>
<para>
<screen>
- # /etc/rc.d/init.d/privoxy start
+ # /etc/init.d/privoxy start
</screen>
</para>
+</sect2>
+
+<sect2 id="start-freebsd">
+<title>FreeBSD and ElectroBSD</title>
<para>
- Or ...
+ To start <application>Privoxy</application> upon booting, add
+ "privoxy_enable='YES'" to <filename>/etc/rc.conf</filename>.
+ <application>Privoxy</application> will use
+ <filename>/usr/local/etc/privoxy/config</filename> as its main
+ configuration file.
</para>
<para>
- <screen>
- # service privoxy start
-</screen>
+ If you installed <application>Privoxy</application> into a jail, the
+ paths above are relative to the jail root.
</para>
-</sect2>
-
-<sect2 id="start-debian">
-<title>Debian</title>
<para>
- We use a script. Note that Debian typically starts &my-app; upon booting per
- default. It will use the file
- <filename>/etc/privoxy/config</filename> as its main configuration
- file.
+ To start <application>Privoxy</application> manually, run:
</para>
<para>
<screen>
- # /etc/init.d/privoxy start
+ # service privoxy onestart
</screen>
</para>
</sect2>
</sect2>
<sect2 id="start-unices">
-<title>Solaris, NetBSD, FreeBSD, HP-UX and others</title>
+<title>Generic instructions for Unix derivates (Solaris, NetBSD, HP-UX etc.)</title>
<para>
Example Unix startup command:
</para>
<para>
<screen>
- # /usr/sbin/privoxy /etc/privoxy/config
+ # /usr/sbin/privoxy --user privoxy /etc/privoxy/config
</screen>
</para>
+<para>
+ Note that if you installed <application>Privoxy</application> through
+ a package manager, the package will probably contain a platform-specific
+ script or configuration file to start <application>Privoxy</application>
+ upon boot.
+</para>
</sect2>
<sect2 id="start-os2">
<sect2 id="start-macosx">
<title>Mac OS X</title>
<para>
- After downloading the privoxy software, unzip the downloaded file by
- double-clicking on the zip file icon. Then, double-click on the
- installer package icon and follow the installation process.
-</para>
-<para>
- The privoxy service will automatically start after a successful
- installation. In addition, the privoxy service will automatically
- start every time your computer starts up.
-</para>
-<para>
- To prevent the privoxy service from automatically starting when your
- computer starts up, remove or rename the folder named
- /Library/StartupItems/Privoxy.
-</para>
-<para>
- A simple application named Privoxy Utility has been created which
- enables administrators to easily start and stop the privoxy service.
-</para>
-<para>
- In addition, the Privoxy Utility presents a simple way for
- administrators to edit the various privoxy config files. A method
- to uninstall the software is also available.
+ The privoxy service will automatically start after a successful installation
+ (and thereafter every time your computer starts up) however you will need to
+ configure your web browser(s) to use it. To do so, configure them to use a
+ proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
</para>
<para>
- An administrator username and password must be supplied in order for
- the Privoxy Utility to perform any of the tasks.
+ To prevent the privoxy service from automatically starting when your computer
+ starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
+ (on OS X 10.5 and higher) or the folder named
+ <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
</para>
-</sect2>
-
-
-<sect2 id="start-amigaos">
-<title>AmigaOS</title>
<para>
- Start <application>Privoxy</application> (with RUN <>NIL:) in your
- <filename>startnet</filename> script (AmiTCP), in
- <filename>s:user-startup</filename> (RoadShow), as startup program in your
- startup script (Genesis), or as startup action (Miami and MiamiDx).
- <application>Privoxy</application> will automatically quit when you quit your
- TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that
- <application>Privoxy</application> is still running).
+ To manually start or stop the privoxy service, use the scripts startPrivoxy.sh
+ and stopPrivoxy.sh supplied in /Applications/Privoxy. They must be run from an
+ administrator account, using sudo.
</para>
</sect2>
-<sect2 id="start-gentoo">
-<title>Gentoo</title>
-<para>
- A script is again used. It will use the file <filename>/etc/privoxy/config
- </filename> as its main configuration file.
-</para>
-<para>
- <screen>
- /etc/init.d/privoxy start
- </screen>
-</para>
-<para>
- Note that <application>Privoxy</application> is not automatically started at
- boot time by default. You can change this with the <literal>rc-update</literal>
- command.
-</para>
-<para>
- <screen>
- rc-update add privoxy default
- </screen>
-</para>
-</sect2>
<!--
<para>
<itemizedlist>
+ <listitem>
+ <para>
+ <emphasis>--config-test</emphasis>
+ </para>
+ <para>
+ Exit after loading the configuration files before binding to
+ the listen address. The exit code signals whether or not the
+ configuration files have been successfully loaded.
+ </para>
+ <para>
+ If the exit code is 1, at least one of the configuration files
+ is invalid, if it is 0, all the configuration files have been
+ successfully loaded (but may still contain errors that can
+ currently only be detected at run time).
+ </para>
+ <para>
+ This option doesn't affect the log setting, combination with
+ <emphasis>--no-daemon</emphasis> is recommended if a configured
+ log file shouldn't be used.
+ </para>
+ </listitem>
<listitem>
<para>
<emphasis>--version</emphasis>
<emphasis>--pre-chroot-nslookup hostname</emphasis>
</para>
<para>
- Specifies a hostname to look up before doing a chroot. On some systems, initializing the
- resolver library involves reading config files from /etc and/or loading additional shared
- libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces
+ Specifies a hostname (for example www.privoxy.org) to look up before doing a chroot.
+ On some systems, initializing the resolver library involves reading config files from
+ /etc and/or loading additional shared libraries from /lib.
+ On these systems, doing a hostname lookup before the chroot reduces
the number of files that must be copied into the chroot tree.
</para>
<para>
<!-- ~~~~~ New section ~~~~~ -->
-<sect2>
+<sect2 id="control-with-webbrowser">
<title>Controlling Privoxy with Your Web Browser</title>
<para>
<application>Privoxy</application>'s user interface can be reached through the special
</member>
<member>
▪ <ulink
- url="http://www.privoxy.org/&p-version;/user-manual/">Documentation</ulink>
+ url="https://www.privoxy.org/&p-version;/user-manual/">Documentation</ulink>
</member>
</simplelist>
</msgtext>
it as a test to see whether it is <application>Privoxy</application>
causing the problem or not. <application>Privoxy</application> continues
to run as a proxy in this case, but all manipulation is disabled, i.e.
- <application>Privoxy</application> acts like a normal forwarding proxy. There
- is even a toggle <link linkend="bookmarklets">Bookmarklet</link> offered, so
- that you can toggle <application>Privoxy</application> with one click from
- your browser.
+ <application>Privoxy</application> acts like a normal forwarding proxy.
</para>
<para>
</para>
<!-- ~~~~~ New section ~~~~~ -->
-<sect2>
+<sect2 id="right-mix">
<title>Finding the Right Mix</title>
<para>
Note that some <link linkend="actions">actions</link>, like cookie suppression
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
-<sect2>
+<sect2 id="how-to-edit">
<title>How to Edit</title>
<para>
The easiest way to edit the actions files is with a browser by
<para>
Generally, an URL pattern has the form
- <literal><domain><port>/<path></literal>, where the
- <literal><domain></literal>, the <literal><port></literal>
+ <literal><host><port>/<path></literal>, where the
+ <literal><host></literal>, the <literal><port></literal>
and the <literal><path></literal> are optional. (This is why the special
<literal>/</literal> pattern matches all URLs). Note that the protocol
portion of the URL pattern (e.g. <literal>http://</literal>) should
<emphasis>not</emphasis> be included in the pattern. This is assumed already!
</para>
<para>
- The pattern matching syntax is different for the domain and path parts of
- the URL. The domain part uses a simple globbing type matching technique,
+ The pattern matching syntax is different for the host and path parts of
+ the URL. The host part uses a simple globbing type matching technique,
while the path part uses more flexible
<ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
Expressions</quote></ulink> (POSIX 1003.2).
</para>
<para>
The port part of a pattern is a decimal port number preceded by a colon
- (<literal>:</literal>). If the domain part contains a numerical IPv6 address,
+ (<literal>:</literal>). If the host part contains a numerical IPv6 address,
it has to be put into angle brackets
(<literal><</literal>, <literal>></literal>).
</para>
<term><literal>www.example.com/</literal></term>
<listitem>
<para>
- is a domain-only pattern and will match any request to <literal>www.example.com</literal>,
+ is a host-only pattern and will match any request to <literal>www.example.com</literal>,
regardless of which document on that server is requested. So ALL pages in
this domain would be covered by the scope of this action. Note that a
simple <literal>example.com</literal> is different and would NOT match.
<term><literal>www.example.com</literal></term>
<listitem>
<para>
- means exactly the same. For domain-only patterns, the trailing <literal>/</literal> may
+ means exactly the same. For host-only patterns, the trailing <literal>/</literal> may
be omitted.
</para>
</listitem>
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>10.0.0.1/</literal></term>
+ <listitem>
+ <para>
+ Matches any URL with the host address <literal>10.0.0.1</literal>.
+ (Note that the real URL uses plain brackets, not angle brackets.)
+ </para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><literal><2001:db8::1>/</literal></term>
<listitem>
<!-- ~~~~~ New section ~~~~~ -->
-<sect3><title>The Domain Pattern</title>
+<sect3 id="host-pattern"><title>The Host Pattern</title>
<para>
- The matching of the domain part offers some flexible options: if the
- domain starts or ends with a dot, it becomes unanchored at that end.
+ The matching of the host part offers some flexible options: if the
+ host pattern starts or ends with a dot, it becomes unanchored at that end.
+ The host pattern is often referred to as domain pattern as it is usually
+ used to match domain names and not IP addresses.
For example:
</para>
<!-- ~~~~~ New section ~~~~~ -->
-<sect3><title>The Path Pattern</title>
+<sect3 id="path-pattern"><title>The Path Pattern</title>
<para>
<application>Privoxy</application> uses <quote>modern</quote> POSIX 1003.2
<!-- ~~~~~ New section ~~~~~ -->
-<sect3 id="tag-pattern"><title>The Tag Pattern</title>
+<sect3 id="tag-pattern"><title>The Request Tag Pattern</title>
<para>
- Tag patterns are used to change the applying actions based on the
- request's tags. Tags can be created with either the
- <link linkend="CLIENT-HEADER-TAGGER">client-header-tagger</link>
+ Request tag patterns are used to change the applying actions based on the
+ request's tags. Tags can be created based on HTTP headers with either
+ the <link linkend="CLIENT-HEADER-TAGGER">client-header-tagger</link>
or the <link linkend="SERVER-HEADER-TAGGER">server-header-tagger</link> action.
</para>
<para>
- Tag patterns have to start with <quote>TAG:</quote>, so &my-app;
- can tell them apart from URL patterns. Everything after the colon
+ Request tag patterns have to start with <quote>TAG:</quote>, so &my-app;
+ can tell them apart from other patterns. Everything after the colon
including white space, is interpreted as a regular expression with
path pattern syntax, except that tag patterns aren't left-anchored
automatically (&my-app; doesn't silently add a <quote>^</quote>,
</para>
<para>
- Sections can contain URL and tag patterns at the same time,
- but tag patterns are checked after the URL patterns and thus
+ Sections can contain URL and request tag patterns at the same time,
+ but request tag patterns are checked after the URL patterns and thus
always overrule them, even if they are located before the URL patterns.
</para>
<para>
- Once a new tag is added, Privoxy checks right away if it's matched by one
- of the tag patterns and updates the action settings accordingly. As a result
- tags can be used to activate other tagger actions, as long as these other
+ Once a new request tag is added, Privoxy checks right away if it's matched by one
+ of the request tag patterns and updates the action settings accordingly. As a result
+ request tags can be used to activate other tagger actions, as long as these other
taggers look for headers that haven't already be parsed.
</para>
</sect3>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 id="negative-tag-patterns"><title>The Negative Request Tag Patterns</title>
+
+<para>
+ To match requests that do not have a certain request tag, specify a negative tag pattern
+ by prefixing the tag pattern line with either <quote>NO-REQUEST-TAG:</quote>
+ or <quote>NO-RESPONSE-TAG:</quote> instead of <quote>TAG:</quote>.
+</para>
+
+<para>
+ Negative request tag patterns created with <quote>NO-REQUEST-TAG:</quote> are checked
+ after all client headers are scanned, the ones created with <quote>NO-RESPONSE-TAG:</quote>
+ are checked after all server headers are scanned. In both cases all the created
+ tags are considered.
+</para>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 id="client-tag-pattern"><title>The Client Tag Pattern</title>
+
+<!-- XXX: This section contains duplicates content from the
+ client-specific-tag documentation. -->
+
+<warning>
+<para>
+ This is an experimental feature. The syntax is likely to change in future versions.
+</para>
+</warning>
+
+<para>
+ Client tag patterns are not set based on HTTP headers but based on
+ the client's IP address. Users can enable them themselves, but the
+ Privoxy admin controls which tags are available and what their effect
+ is.
+</para>
+
+<para>
+ After a client-specific tag has been defined with the
+ <link linkend="client-specific-tag">client-specific-tag</link>,
+ directive, action sections can be activated based on the tag by using a
+ CLIENT-TAG pattern. The CLIENT-TAG pattern is evaluated at the same priority
+ as URL patterns, as a result the last matching pattern wins. Tags that
+ are created based on client or server headers are evaluated later on
+ and can overrule CLIENT-TAG and URL patterns!
+</para>
+<para>
+ The tag is set for all requests that come from clients that requested
+ it to be set. Note that "clients" are differentiated by IP address,
+ if the IP address changes the tag has to be requested again.
+</para>
+<para>
+ Clients can request tags to be set by using the CGI interface <ulink
+ url="http://config.privoxy.org/client-tags">http://config.privoxy.org/client-tags</ulink>.
+</para>
+
+<para>
+ Example:
+</para>
+
+<para>
+ <screen>
+# If the admin defined the client-specific-tag circumvent-blocks,
+# and the request comes from a client that previously requested
+# the tag to be set, overrule all previous +block actions that
+# are enabled based on URL to CLIENT-TAG patterns.
+{-block}
+CLIENT-TAG:^circumvent-blocks$
+
+# This section is not overruled because it's located after
+# the previous one.
+{+block{Nobody is supposed to request this.}}
+example.org/blocked-example-page</screen>
+</para>
+
+</sect3>
+
</sect2>
<!-- ~ End section ~ -->
<term>Example usage:</term>
<listitem>
<para>
- <screen>+add-header{X-User-Tracking: sucks}</screen>
+ <screen># Add a DNT ("Do not track") header to all requests,
+# event to those that already have one.
+#
+# This is just an example, not a recommendation.
+#
+# There is no reason to believe that user-tracking websites care
+# about the DNT header and depending on the User-Agent, adding the
+# header may make user-tracking easier.
+{+add-header{DNT: 1}}
+/</screen>
</para>
</listitem>
</varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
- <para>Parameterized.</para>
+ <para>Multi-value.</para>
</listitem>
</varlistentry>
and use their output as input.
</para>
<para>
- If the request URL gets changed, &my-app; will detect that and use the new
+ If the request URI gets changed, &my-app; will detect that and use the new
one. This can be used to rewrite the request destination behind the client's
back, for example to specify a Tor exit relay for certain requests.
</para>
{+client-header-filter{hide-tor-exit-notation}}
/
</screen>
- </para>
+ </para>
</listitem>
</varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
- <para>Parameterized.</para>
+ <para>Multi-value.</para>
</listitem>
</varlistentry>
TAG:^User-Agent: Ubuntu APT-HTTP/
TAG:^User-Agent: MPlayer/
</screen>
+ </para>
+ <para>
+ <screen>
+# Tag all requests with the Range header set
+{+client-header-tagger{range-requests}}
+/
+
+# Disable filtering for the tagged requests.
+#
+# With filtering enabled Privoxy would remove the Range headers
+# to be able to filter the whole response. The downside is that
+# it prevents clients from resuming downloads or skipping over
+# parts of multimedia files.
+{-filter -deanimate-gifs}
+TAG:^RANGE-REQUEST$
+ </screen>
+ </para>
+ <para>
+ <screen>
+# Tag all requests with the client IP address
+#
+# (Technically the client IP address isn't included in the
+# client headers but client-header taggers can set it anyway.
+# For details see the tagger in default.filter)
+{+client-header-tagger{client-ip-address}}
+/
+
+# Change forwarding settings for requests coming from address 10.0.0.1
+{+forward-override{forward-socks5 127.0.1.2:2222 .}}
+TAG:^IP-ADDRESS: 10\.0\.0\.1$
+ </screen>
</para>
</listitem>
</varlistentry>
<para>
This is a left-over from the time when <application>Privoxy</application>
didn't support important HTTP/1.1 features well. It is left here for the
- unlikely case that you experience HTTP/1.1 related problems with some server
- out there. Not all HTTP/1.1 features and requirements are supported yet,
- so there is a chance you might need this action.
+ unlikely case that you experience HTTP/1.1-related problems with some server
+ out there.
+ </para>
+ <para>
+ Note that enabling this action is only a workaround. It should not
+ be enabled for sites that work without it. While it shouldn't break
+ any pages, it has an (usually negative) performance impact.
+ </para>
+ <para>
+ If you come across a site where enabling this action helps, please report it,
+ so the cause of the problem can be analyzed. If the problem turns out to be
+ caused by a bug in <application>Privoxy</application> it should be
+ fixed so the following release works without the work around.
</para>
</listitem>
</varlistentry>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="fast-redirects">
-<title>fast-redirects</title>
+<sect3 renderas="sect4" id="external-filter">
+<title>external-filter</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
- <para>Fool some click-tracking scripts and speed up indirect links.</para>
+ <para>Modify content using a programming language of your choice.</para>
</listitem>
</varlistentry>
<term>Effect:</term>
<listitem>
<para>
- Detects redirection URLs and redirects the browser without contacting
- the redirection server first.
+ All instances of text-based type, most notably HTML and JavaScript, to which
+ this action applies, can be filtered on-the-fly through the specified external
+ filter.
+ By default plain text documents are exempted from filtering, because web
+ servers often use the <literal>text/plain</literal> MIME type for all files
+ whose type they don't know.)
</para>
</listitem>
</varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
- <para>Parameterized.</para>
+ <para>Multi-value.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ The name of an external content filter, as defined in the
+ <link linkend="filter-file">filter file</link>.
+ External filters can be defined in one or more files as defined by the
+ <literal><link linkend="filterfile">filterfile</link></literal>
+ option in the <link linkend="config">config file</link>.
+ </para>
+ <para>
+ When used in its negative form,
+ and without parameters, <emphasis>all</emphasis> filtering with external
+ filters is completely disabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ External filters are scripts or programs that can modify the content in
+ case common <literal><link linkend="filter">filters</link></literal>
+ aren't powerful enough. With the exception that this action doesn't
+ use pcrs-based filters, the notes in the
+ <literal><link linkend="filter">filter</link></literal> section apply.
+ </para>
+ <warning>
+ <para>
+ Currently external filters are executed with &my-app;'s privileges.
+ Only use external filters you understand and trust.
+ </para>
+ </warning>
+ <para>
+ This feature is experimental, the <literal><link
+ linkend="external-filter-syntax">syntax</link></literal>
+ may change in the future.
+ </para>
+
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen>+external-filter{fancy-filter}</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="fast-redirects">
+<title>fast-redirects</title>
+
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Fool some click-tracking scripts and speed up indirect links.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Detects redirection URLs and redirects the browser without contacting
+ the redirection server first.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Type:</term>
+ <!-- boolean, parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
</listitem>
</varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
- <para>Parameterized.</para>
+ <para>Multi-value.</para>
</listitem>
</varlistentry>
</para>
<para>
<anchor id="filter-js-events">
- <screen>+filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites).</screen>
+ <screen>+filter{js-events} # Kill JavaScript event bindings and timers (Radically destructive! Only for extra nasty sites).</screen>
</para>
<para>
<anchor id="filter-html-annoyances">
</para>
<para>
<anchor id="filter-refresh-tags">
- <screen>+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups).</screen>
+ <screen>+filter{refresh-tags} # Kill automatic refresh tags if refresh time is larger than 9 seconds.</screen>
</para>
<para>
<anchor id="filter-unsolicited-popups">
- <screen>+filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.</screen>
- </para>
- <para>
- <anchor id="filter-all-popups">
- <screen>+filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.</screen>
- </para>
- <para>
- <anchor id="filter-img-reorder">
- <screen>+filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.</screen>
- </para>
- <para>
- <anchor id="filter-banners-by-size">
- <screen>+filter{banners-by-size} # Kill banners by size.</screen>
- </para>
- <para>
- <anchor id="filter-banners-by-link">
- <screen>+filter{banners-by-link} # Kill banners by their links to known clicktrackers.</screen>
- </para>
- <para>
- <anchor id="filter-webbugs">
- <screen>+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).</screen>
- </para>
- <para>
- <anchor id="filter-tiny-textforms">
- <screen>+filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.</screen>
- </para>
- <para>
- <anchor id="filter-jumping-windows">
- <screen>+filter{jumping-windows} # Prevent windows from resizing and moving themselves.</screen>
- </para>
- <para>
- <anchor id="filter-frameset-borders">
- <screen>+filter{frameset-borders} # Give frames a border and make them resizable.</screen>
- </para>
- <para>
- <anchor id="filter-demoronizer">
- <screen>+filter{demoronizer} # Fix MS's non-standard use of standard charsets.</screen>
- </para>
- <para>
- <anchor id="filter-shockwave-flash">
- <screen>+filter{shockwave-flash} # Kill embedded Shockwave Flash objects.</screen>
- </para>
- <para>
- <anchor id="filter-quicktime-kioskmode">
- <screen>+filter{quicktime-kioskmode} # Make Quicktime movies saveable.</screen>
- </para>
- <para>
- <anchor id="filter-fun">
- <screen>+filter{fun} # Text replacements for subversive browsing fun!</screen>
- </para>
- <para>
- <anchor id="filter-crude-parental">
- <screen>+filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.</screen>
- </para>
- <para>
- <anchor id="filter-ie-exploits">
- <screen>+filter{ie-exploits} # Disable some known Internet Explorer bug exploits.</screen>
- </para>
- <para>
- <anchor id="filter-site-specifics">
- <screen>+filter{site-specifics} # Cure for site-specific problems. Don't apply generally!</screen>
+ <screen>+filter{unsolicited-popups} # Disable only unsolicited pop-up windows.</screen>
</para>
- <para>
- <anchor id="filter-no-ping">
- <screen>+filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.</screen>
- </para>
- <para>
- <anchor id="filter-google">
- <screen>+filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.</screen>
- </para>
- <para>
- <anchor id="filter-yahoo">
- <screen>+filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.</screen>
- </para>
- <para>
- <anchor id="filter-msn">
- <screen>+filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.</screen>
- </para>
- <para>
- <anchor id="filter-blogspot">
- <screen>+filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="force-text-mode">
-<title>force-text-mode</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Force <application>Privoxy</application> to treat a document as if it was in some kind of <emphasis>text</emphasis> format. </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Declares a document as text, even if the <quote>Content-Type:</quote> isn't detected as such.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Boolean.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- N/A
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- As explained <literal><link linkend="filter">above</link></literal>,
- <application>Privoxy</application> tries to only filter files that are
- in some kind of text format. The same restrictions apply to
- <literal><link linkend="content-type-overwrite">content-type-overwrite</link></literal>.
- <literal>force-text-mode</literal> declares a document as text,
- without looking at the <quote>Content-Type:</quote> first.
- </para>
- <warning>
- <para>
- Think twice before activating this action. Filtering binary data
- with regular expressions can cause file damage.
- </para>
- </warning>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen>
-+force-text-mode
- </screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="forward-override">
-<title>forward-override</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Change the forwarding settings based on User-Agent or request origin</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Overrules the forward directives in the configuration file.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Multi-value.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <itemizedlist>
- <listitem>
- <para><quote>forward .</quote> to use a direct connection without any additional proxies.</para>
- </listitem>
- <listitem>
- <para>
- <quote>forward 127.0.0.1:8123</quote> to use the HTTP proxy listening at 127.0.0.1 port 8123.
- </para>
- </listitem>
- <listitem>
- <para>
- <quote>forward-socks4a 127.0.0.1:9050 .</quote> to use the socks4a proxy listening at
- 127.0.0.1 port 9050. Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote>
- to use a socks4 connection (with local DNS resolution) instead, use <quote>forward-socks5</quote>
- for socks5 connections (with remote DNS resolution).
- </para>
- </listitem>
- <listitem>
- <para>
- <quote>forward-socks4a 127.0.0.1:9050 proxy.example.org:8000</quote> to use the socks4a proxy
- listening at 127.0.0.1 port 9050 to reach the HTTP proxy listening at proxy.example.org port 8000.
- Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote> to use a socks4 connection
- (with local DNS resolution) instead, use <quote>forward-socks5</quote>
- for socks5 connections (with remote DNS resolution).
- </para>
- </listitem>
- </itemizedlist>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- This action takes parameters similar to the
- <link linkend="forwarding">forward</link> directives in the configuration
- file, but without the URL pattern. It can be used as replacement, but normally it's only
- used in cases where matching based on the request URL isn't sufficient.
- </para>
- <warning>
- <para>
- Please read the description for the <link linkend="forwarding">forward</link> directives before
- using this action. Forwarding to the wrong people will reduce your privacy and increase the
- chances of man-in-the-middle attacks.
- </para>
- <para>
- If the ports are missing or invalid, default values will be used. This might change
- in the future and you shouldn't rely on it. Otherwise incorrect syntax causes Privoxy
- to exit.
- </para>
- <para>
- Use the <ulink url="http://config.privoxy.org/show-url-info">show-url-info CGI page</ulink>
- to verify that your forward settings do what you thought the do.
- </para>
- </warning>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen>
-# Always use direct connections for requests previously tagged as
-# <quote>User-Agent: fetch libfetch/2.0</quote> and make sure
-# resuming downloads continues to work.
-# This way you can continue to use Tor for your normal browsing,
-# without overloading the Tor network with your FreeBSD ports updates
-# or downloads of bigger files like ISOs.
-# Note that HTTP headers are easy to fake and therefore their
-# values are as (un)trustworthy as your clients and users.
-{+forward-override{forward .} \
- -hide-if-modified-since \
- -overwrite-last-modified \
-}
-TAG:^User-Agent: fetch libfetch/2\.0$
- </screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="handle-as-empty-document">
-<title>handle-as-empty-document</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Mark URLs that should be replaced by empty documents <emphasis>if they get blocked</emphasis></para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- This action alone doesn't do anything noticeable. It just marks URLs.
- If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
- the presence or absence of this mark decides whether an HTML <quote>BLOCKED</quote>
- page, or an empty document will be sent to the client as a substitute for the blocked content.
- The <emphasis>empty</emphasis> document isn't literally empty, but actually contains a single space.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Boolean.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- N/A
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Some browsers complain about syntax errors if JavaScript documents
- are blocked with <application>Privoxy's</application>
- default HTML page; this option can be used to silence them.
- And of course this action can also be used to eliminate the &my-app;
- BLOCKED message in frames.
- </para>
- <para>
- The content type for the empty document can be specified with
- <literal><link linkend="content-type-overwrite">content-type-overwrite{}</link></literal>,
- but usually this isn't necessary.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen># Block all documents on example.org that end with ".js",
-# but send an empty document instead of the usual HTML message.
-{+block{Blocked JavaScript} +handle-as-empty-document}
-example.org/.*\.js$
- </screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="handle-as-image">
-<title>handle-as-image</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Mark URLs as belonging to images (so they'll be replaced by images <emphasis>if they do get blocked</emphasis>, rather than HTML pages)</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- This action alone doesn't do anything noticeable. It just marks URLs as images.
- If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
- the presence or absence of this mark decides whether an HTML <quote>blocked</quote>
- page, or a replacement image (as determined by the <literal><link
- linkend="set-image-blocker">set-image-blocker</link></literal> action) will be sent to the
- client as a substitute for the blocked content.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Boolean.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- N/A
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- The below generic example section is actually part of <filename>default.action</filename>.
- It marks all URLs with well-known image file name extensions as images and should
- be left intact.
- </para>
- <para>
- Users will probably only want to use the handle-as-image action in conjunction with
- <literal><link linkend="block">block</link></literal>, to block sources of banners, whose URLs don't
- reflect the file type, like in the second example section.
- </para>
- <para>
- Note that you cannot treat HTML pages as images in most cases. For instance, (in-line) ad
- frames require an HTML page to be sent, or they won't display properly.
- Forcing <literal>handle-as-image</literal> in this situation will not replace the
- ad frame with an image, but lead to error messages.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage (sections):</term>
- <listitem>
- <para>
- <screen># Generic image extensions:
-#
-{+handle-as-image}
-/.*\.(gif|jpg|jpeg|png|bmp|ico)$
-
-# These don't look like images, but they're banners and should be
-# blocked as images:
-#
-{+block{Nasty banners.} +handle-as-image}
-nasty-banner-server.example.com/junk.cgi\?output=trash
-</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="hide-accept-language">
-<title>hide-accept-language</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Pretend to use different language settings.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes or replaces the <quote>Accept-Language:</quote> HTTP header in client requests.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- Keyword: <quote>block</quote>, or any user defined value.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Faking the browser's language settings can be useful to make a
- foreign User-Agent set with
- <literal><link linkend="hide-user-agent">hide-user-agent</link></literal>
- more believable.
- </para>
- <para>
- However some sites with content in different languages check the
- <quote>Accept-Language:</quote> to decide which one to take by default.
- Sometimes it isn't possible to later switch to another language without
- changing the <quote>Accept-Language:</quote> header first.
- </para>
- <para>
- Therefore it's a good idea to either only change the
- <quote>Accept-Language:</quote> header to languages you understand,
- or to languages that aren't wide spread.
- </para>
- <para>
- Before setting the <quote>Accept-Language:</quote> header
- to a rare language, you should consider that it helps to
- make your requests unique and thus easier to trace.
- If you don't plan to change this header frequently,
- you should stick to a common language.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage (section):</term>
- <listitem>
- <para>
- <screen># Pretend to use Canadian language settings.
-{+hide-accept-language{en-ca} \
-+hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
-}
-/ </screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="hide-content-disposition">
-<title>hide-content-disposition</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Prevent download menus for content you prefer to view inside the browser.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes or replaces the <quote>Content-Disposition:</quote> HTTP header set by some servers.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- Keyword: <quote>block</quote>, or any user defined value.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Some servers set the <quote>Content-Disposition:</quote> HTTP header for
- documents they assume you want to save locally before viewing them.
- The <quote>Content-Disposition:</quote> header contains the file name
- the browser is supposed to use by default.
- </para>
- <para>
- In most browsers that understand this header, it makes it impossible to
- <emphasis>just view</emphasis> the document, without downloading it first,
- even if it's just a simple text file or an image.
- </para>
- <para>
- Removing the <quote>Content-Disposition:</quote> header helps
- to prevent this annoyance, but some browsers additionally check the
- <quote>Content-Type:</quote> header, before they decide if they can
- display a document without saving it first. In these cases, you have
- to change this header as well, before the browser stops displaying
- download menus.
- </para>
- <para>
- It is also possible to change the server's file name suggestion
- to another one, but in most cases it isn't worth the time to set
- it up.
- </para>
- <para>
- This action will probably be removed in the future,
- use server-header filters instead.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen># Disarm the download link in Sourceforge's patch tracker
-{ -filter \
- +content-type-overwrite{text/plain}\
- +hide-content-disposition{block} }
- .sourceforge.net/tracker/download\.php</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="hide-if-modified-since">
-<title>hide-if-modified-since</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Prevent yet another way to track the user's steps between sessions.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes the <quote>If-Modified-Since:</quote> HTTP client header or modifies its value.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- Keyword: <quote>block</quote>, or a user defined value that specifies a range of hours.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Removing this header is useful for filter testing, where you want to force a real
- reload instead of getting status code <quote>304</quote>, which would cause the
- browser to use a cached copy of the page.
- </para>
- <para>
- Instead of removing the header, <literal>hide-if-modified-since</literal> can
- also add or subtract a random amount of time to/from the header's value.
- You specify a range of minutes where the random factor should be chosen from and
- <application>Privoxy</application> does the rest. A negative value means
- subtracting, a positive value adding.
- </para>
- <para>
- Randomizing the value of the <quote>If-Modified-Since:</quote> makes
- it less likely that the server can use the time as a cookie replacement,
- but you will run into caching problems if the random range is too high.
- </para>
- <para>
- It is a good idea to only use a small negative value and let
- <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>
- handle the greater changes.
- </para>
- <para>
- It is also recommended to use this action together with
- <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>,
- otherwise it's more or less pointless.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage (section):</term>
- <listitem>
- <para>
- <screen># Let the browser revalidate but make tracking based on the time less likely.
-{+hide-if-modified-since{-60} \
- +overwrite-last-modified{randomize} \
- +crunch-if-none-match}
-/</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="hide-from-header">
-<title>hide-from-header</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Keep your (old and ill) browser from telling web servers your email address</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes any existing <quote>From:</quote> HTTP header, or replaces it with the
- specified string.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- Keyword: <quote>block</quote>, or any user defined value.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- The keyword <quote>block</quote> will completely remove the header
- (not to be confused with the <literal><link linkend="block">block</link></literal>
- action).
- </para>
- <para>
- Alternately, you can specify any value you prefer to be sent to the web
- server. If you do, it is a matter of fairness not to use any address that
- is actually used by a real person.
- </para>
- <para>
- This action is rarely needed, as modern web browsers don't send
- <quote>From:</quote> headers anymore.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen>+hide-from-header{block}</screen> or
- <screen>+hide-from-header{spam-me-senseless@sittingduck.example.com}</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="hide-referrer">
-<title>hide-referrer</title>
-<anchor id="hide-referer">
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Conceal which link you followed to get to a particular site</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes the <quote>Referer:</quote> (sic) HTTP header from the client request,
- or replaces it with a forged one.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <itemizedlist>
- <listitem>
- <para><quote>conditional-block</quote> to delete the header completely if the host has changed.</para>
- </listitem>
- <listitem>
- <para><quote>conditional-forge</quote> to forge the header if the host has changed.</para>
- </listitem>
- <listitem>
- <para><quote>block</quote> to delete the header unconditionally.</para>
- </listitem>
- <listitem>
- <para><quote>forge</quote> to pretend to be coming from the homepage of the server we are talking to.</para>
- </listitem>
- <listitem>
- <para>Any other string to set a user defined referrer.</para>
- </listitem>
- </itemizedlist>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- <literal>conditional-block</literal> is the only parameter,
- that isn't easily detected in the server's log file. If it blocks the
- referrer, the request will look like the visitor used a bookmark or
- typed in the address directly.
- </para>
- <para>
- Leaving the referrer unmodified for requests on the same host
- allows the server owner to see the visitor's <quote>click path</quote>,
- but in most cases she could also get that information by comparing
- other parts of the log file: for example the User-Agent if it isn't
- a very common one, or the user's IP address if it doesn't change between
- different requests.
- </para>
- <para>
- Always blocking the referrer, or using a custom one, can lead to
- failures on servers that check the referrer before they answer any
- requests, in an attempt to prevent their content from being
- embedded or linked to elsewhere.
- </para>
- <para>
- Both <literal>conditional-block</literal> and <literal>forge</literal>
- will work with referrer checks, as long as content and valid referring page
- are on the same host. Most of the time that's the case.
- </para>
- <para>
- <literal>hide-referer</literal> is an alternate spelling of
- <literal>hide-referrer</literal> and the two can be can be freely
- substituted with each other. (<quote>referrer</quote> is the
- correct English spelling, however the HTTP specification has a bug - it
- requires it to be spelled as <quote>referer</quote>.)
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen>+hide-referrer{forge}</screen> or
- <screen>+hide-referrer{http://www.yahoo.com/}</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="hide-user-agent">
-<title>hide-user-agent</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Try to conceal your type of browser and client operating system</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Replaces the value of the <quote>User-Agent:</quote> HTTP header
- in client requests with the specified value.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- Any user-defined string.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <warning>
- <para>
- This can lead to problems on web sites that depend on looking at this header in
- order to customize their content for different browsers (which, by the
- way, is <emphasis>NOT</emphasis> the right thing to do: good web sites
- work browser-independently).
- </para>
- </warning>
- <para>
- Using this action in multi-user setups or wherever different types of
- browsers will access the same <application>Privoxy</application> is
- <emphasis>not recommended</emphasis>. In single-user, single-browser
- setups, you might use it to delete your OS version information from
- the headers, because it is an invitation to exploit known bugs for your
- OS. It is also occasionally useful to forge this in order to access
- sites that won't let you in otherwise (though there may be a good
- reason in some cases).
- </para>
- <para>
- More information on known user-agent strings can be found at
- <ulink url="http://www.user-agents.org/">http://www.user-agents.org/</ulink>
- and
- <ulink url="http://en.wikipedia.org/wiki/User_agent">http://en.wikipedia.org/wiki/User_agent</ulink>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen>+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="limit-connect">
-<title>limit-connect</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Prevent abuse of <application>Privoxy</application> as a TCP proxy relay or disable SSL for untrusted sites</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Specifies to which ports HTTP CONNECT requests are allowable.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
- defaulting to 0 and the maximum to 65K).
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- By default, i.e. if no <literal>limit-connect</literal> action applies,
- <application>Privoxy</application> allows HTTP CONNECT requests to all
- ports. Use <literal>limit-connect</literal> if fine-grained control
- is desired for some or all destinations.
- </para>
- <para>
- The CONNECT methods exists in HTTP to allow access to secure websites
- (<quote>https://</quote> URLs) through proxies. It works very simply:
- the proxy connects to the server on the specified port, and then
- short-circuits its connections to the client and to the remote server.
- This means CONNECT-enabled proxies can be used as TCP relays very easily.
- </para>
- <para>
- <application>Privoxy</application> relays HTTPS traffic without seeing
- the decoded content. Websites can leverage this limitation to circumvent &my-app;'s
- filters. By specifying an invalid port range you can disable HTTPS entirely.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usages:</term>
- <listitem>
- <!-- I had trouble getting the spacing to look right in my browser -->
- <!-- I probably have the wrong font setup, bollocks. -->
- <!-- Apparently the emphasis tag uses a proportional font no matter what -->
- <para>
- <screen>+limit-connect{443} # Port 443 is OK.
-+limit-connect{80,443} # Ports 80 and 443 are OK.
-+limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
-+limit-connect{-} # All ports are OK
-+limit-connect{,} # No HTTPS/SSL traffic is allowed</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="prevent-compression">
-<title>prevent-compression</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>
- Ensure that servers send the content uncompressed, so it can be
- passed through <literal><link linkend="filter">filter</link></literal>s.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Removes the Accept-Encoding header which can be used to ask for compressed transfer.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Boolean.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- N/A
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- More and more websites send their content compressed by default, which
- is generally a good idea and saves bandwidth. But the <literal><link
- linkend="filter">filter</link></literal> and
- <literal><link linkend="deanimate-gifs">deanimate-gifs</link></literal>
- actions need access to the uncompressed data.
- </para>
- <para>
- When compiled with zlib support (available since &my-app; 3.0.7), content that should be
- filtered is decompressed on-the-fly and you don't have to worry about this action.
- If you are using an older &my-app; version, or one that hasn't been compiled with zlib
- support, this action can be used to convince the server to send the content uncompressed.
- </para>
- <para>
- Most text-based instances compress very well, the size is seldom decreased by less than 50%,
- for markup-heavy instances like news feeds saving more than 90% of the original size isn't
- unusual.
- </para>
- <para>
- Not using compression will therefore slow down the transfer, and you should only
- enable this action if you really need it. As of &my-app; 3.0.7 it's disabled in all
- predefined action settings.
- </para>
- <para>
- Note that some (rare) ill-configured sites don't handle requests for uncompressed
- documents correctly. Broken PHP applications tend to send an empty document body,
- some IIS versions only send the beginning of the content. If you enable
- <literal>prevent-compression</literal> per default, you might want to add
- exceptions for those sites. See the example for how to do that.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage (sections):</term>
- <listitem>
- <para>
- <screen>
-# Selectively turn off compression, and enable a filter
-#
-{ +filter{tiny-textforms} +prevent-compression }
-# Match only these sites
- .google.
- sourceforge.net
- sf.net
-
-# Or instead, we could set a universal default:
-#
-{ +prevent-compression }
- / # Match all sites
-
-# Then maybe make exceptions for broken sites:
-#
-{ -prevent-compression }
-.compusa.com/</screen>
- </para>
- </listitem>
- </varlistentry>
-
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="overwrite-last-modified">
-<title>overwrite-last-modified</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Prevent yet another way to track the user's steps between sessions.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes the <quote>Last-Modified:</quote> HTTP server header or modifies its value.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- One of the keywords: <quote>block</quote>, <quote>reset-to-request-time</quote>
- and <quote>randomize</quote>
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Removing the <quote>Last-Modified:</quote> header is useful for filter
- testing, where you want to force a real reload instead of getting status
- code <quote>304</quote>, which would cause the browser to reuse the old
- version of the page.
- </para>
- <para>
- The <quote>randomize</quote> option overwrites the value of the
- <quote>Last-Modified:</quote> header with a randomly chosen time
- between the original value and the current time. In theory the server
- could send each document with a different <quote>Last-Modified:</quote>
- header to track visits without using cookies. <quote>Randomize</quote>
- makes it impossible and the browser can still revalidate cached documents.
- </para>
- <para>
- <quote>reset-to-request-time</quote> overwrites the value of the
- <quote>Last-Modified:</quote> header with the current time. You could use
- this option together with
- <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
- to further customize your random range.
- </para>
- <para>
- The preferred parameter here is <quote>randomize</quote>. It is safe
- to use, as long as the time settings are more or less correct.
- If the server sets the <quote>Last-Modified:</quote> header to the time
- of the request, the random range becomes zero and the value stays the same.
- Therefore you should later randomize it a second time with
- <literal><link linkend="hide-if-modified-since">hided-if-modified-since</link></literal>,
- just to be sure.
- </para>
- <para>
- It is also recommended to use this action together with
- <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen># Let the browser revalidate without being tracked across sessions
-{ +hide-if-modified-since{-60} \
- +overwrite-last-modified{randomize} \
- +crunch-if-none-match}
-/</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="redirect">
-<title>redirect</title>
-<!--
-new action
--->
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>
- Redirect requests to other sites.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Convinces the browser that the requested document has been moved
- to another location and the browser should get it from there.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- An absolute URL or a single pcrs command.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Requests to which this action applies are answered with a
- HTTP redirect to URLs of your choosing. The new URL is
- either provided as parameter, or derived by applying a
- single pcrs command to the original URL.
- </para>
- <para>
- This action will be ignored if you use it together with
- <literal><link linkend="block">block</link></literal>.
- It can be combined with
- <literal><link linkend="fast-redirects">fast-redirects{check-decoded-url}</link></literal>
- to redirect to a decoded version of a rewritten URL.
- </para>
- <para>
- Use this action carefully, make sure not to create redirection loops
- and be aware that using your own redirects might make it
- possible to fingerprint your requests.
- </para>
- <para>
- In case of problems with your redirects, or simply to watch
- them working, enable <link linkend="DEBUG">debug 128</link>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usages:</term>
- <listitem>
- <para>
- <screen># Replace example.com's style sheet with another one
-{ +redirect{http://localhost/css-replacements/example.com.css} }
- example.com/stylesheet\.css
-
-# Create a short, easy to remember nickname for a favorite site
-# (relies on the browser accept and forward invalid URLs to &my-app;)
-{ +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
- a
-
-# Always use the expanded view for Undeadly.org articles
-# (Note the $ at the end of the URL pattern to make sure
-# the request for the rewritten URL isn't redirected as well)
-{+redirect{s@$@&mode=expanded@}}
-undeadly.org/cgi\?action=article&sid=\d*$
-
-# Redirect Google search requests to MSN
-{+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
-.google.com/search
-
-# Redirect MSN search requests to Yahoo
-{+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
-search.msn.com//results\.aspx\?q=
-
-# Redirect remote requests for this manual
-# to the local version delivered by Privoxy
-{+redirect{s@^http://www@http://config@}}
-www.privoxy.org/user-manual/</screen>
- </para>
- </listitem>
- </varlistentry>
-
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="server-header-filter">
-<title>server-header-filter</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>
- Rewrite or remove single server headers.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- All server headers to which this action applies are filtered on-the-fly
- through the specified regular expression based substitutions.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- boolean, parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- The name of a server-header filter, as defined in one of the
- <link linkend="filter-file">filter files</link>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Server-header filters are applied to each header on its own, not to
- all at once. This makes it easier to diagnose problems, but on the downside
- you can't write filters that only change header x if header y's value is z.
- You can do that by using tags though.
- </para>
- <para>
- Server-header filters are executed after the other header actions have finished
- and use their output as input.
- </para>
- <para>
- Please refer to the <link linkend="filter-file">filter file chapter</link>
- to learn which server-header filters are available by default, and how to
- create your own.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage (section):</term>
- <listitem>
- <para>
- <screen>
-{+server-header-filter{html-to-xml}}
-example.org/xml-instance-that-is-delivered-as-html
-
-{+server-header-filter{xml-to-html}}
-example.org/instance-that-is-delivered-as-xml-but-is-not
- </screen>
- </para>
- </listitem>
- </varlistentry>
-
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="server-header-tagger">
-<title>server-header-tagger</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>
- Enable or disable filters based on the Content-Type header.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Server headers to which this action applies are filtered on-the-fly through
- the specified regular expression based substitutions, the result is used as
- tag.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- boolean, parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- The name of a server-header tagger, as defined in one of the
- <link linkend="filter-file">filter files</link>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- Server-header taggers are applied to each header on its own,
- and as the header isn't modified, each tagger <quote>sees</quote>
- the original.
- </para>
- <para>
- Server-header taggers are executed before all other header actions
- that modify server headers. Their tags can be used to control
- all of the other server-header actions, the content filters
- and the crunch actions (<link linkend="redirect">redirect</link>
- and <link linkend="block">block</link>).
- </para>
- <para>
- Obviously crunching based on tags created by server-header taggers
- doesn't prevent the request from showing up in the server's log file.
- </para>
-
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage (section):</term>
- <listitem>
- <para>
- <screen>
-# Tag every request with the content type declared by the server
-{+server-header-tagger{content-type}}
-/
- </screen>
- </para>
- </listitem>
- </varlistentry>
-
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="session-cookies-only">
-<title>session-cookies-only</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>
- Allow only temporary <quote>session</quote> cookies (for the current
- browser session <emphasis>only</emphasis>).
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- Deletes the <quote>expires</quote> field from <quote>Set-Cookie:</quote>
- server headers. Most browsers will not store such cookies permanently and
- forget them in between sessions.
- </para>
- </listitem>
- </varlistentry>
-
-<varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Boolean.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <para>
- N/A
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- This is less strict than <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> /
- <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal> and allows you to browse
- websites that insist or rely on setting cookies, without compromising your privacy too badly.
- </para>
- <para>
- Most browsers will not permanently store cookies that have been processed by
- <literal>session-cookies-only</literal> and will forget about them between sessions.
- This makes profiling cookies useless, but won't break sites which require cookies so
- that you can log in for transactions. This is generally turned on for all
- sites, and is the recommended setting.
- </para>
- <para>
- It makes <emphasis>no sense at all</emphasis> to use <literal>session-cookies-only</literal>
- together with <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> or
- <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>. If you do, cookies
- will be plainly killed.
- </para>
- <para>
- Note that it is up to the browser how it handles such cookies without an <quote>expires</quote>
- field. If you use an exotic browser, you might want to try it out to be sure.
- </para>
- <para>
- This setting also has no effect on cookies that may have been stored
- previously by the browser before starting <application>Privoxy</application>.
- These would have to be removed manually.
- </para>
- <para>
- <application>Privoxy</application> also uses
- the <link linkend="filter-content-cookies">content-cookies filter</link>
- to block some types of cookies. Content cookies are not effected by
- <literal>session-cookies-only</literal>.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- <screen>+session-cookies-only</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3 renderas="sect4" id="set-image-blocker">
-<title>set-image-blocker</title>
-
-<variablelist>
- <varlistentry>
- <term>Typical use:</term>
- <listitem>
- <para>Choose the replacement for blocked images</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Effect:</term>
- <listitem>
- <para>
- This action alone doesn't do anything noticeable. If <emphasis>both</emphasis>
- <literal><link linkend="block">block</link></literal> <emphasis>and</emphasis> <literal><link
- linkend="handle-as-image">handle-as-image</link></literal> <emphasis>also</emphasis>
- apply, i.e. if the request is to be blocked as an image,
- <emphasis>then</emphasis> the parameter of this action decides what will be
- sent as a replacement.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Type:</term>
- <!-- Boolean, Parameterized, Multi-value -->
- <listitem>
- <para>Parameterized.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Parameter:</term>
- <listitem>
- <itemizedlist>
- <listitem>
- <para>
- <quote>pattern</quote> to send a built-in checkerboard pattern image. The image is visually
- decent, scales very well, and makes it obvious where banners were busted.
- </para>
- </listitem>
- <listitem>
- <para>
- <quote>blank</quote> to send a built-in transparent image. This makes banners disappear
- completely, but makes it hard to detect where <application>Privoxy</application> has blocked
- images on a given page and complicates troubleshooting if <application>Privoxy</application>
- has blocked innocent images, like navigation icons.
- </para>
- </listitem>
- <listitem>
- <para>
- <quote><replaceable class="parameter">target-url</replaceable></quote> to
- send a redirect to <replaceable class="parameter">target-url</replaceable>. You can redirect
- to any image anywhere, even in your local filesystem via <quote>file:///</quote> URL.
- (But note that not all browsers support redirecting to a local file system).
- </para>
- <para>
- A good application of redirects is to use special <application>Privoxy</application>-built-in
- URLs, which send the built-in images, as <replaceable class="parameter">target-url</replaceable>.
- This has the same visual effect as specifying <quote>blank</quote> or <quote>pattern</quote> in
- the first place, but enables your browser to cache the replacement image, instead of requesting
- it over and over again.
- </para>
- </listitem>
- </itemizedlist>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Notes:</term>
- <listitem>
- <para>
- The URLs for the built-in images are <quote>http://config.privoxy.org/send-banner?type=<replaceable
- class="parameter">type</replaceable></quote>, where <replaceable class="parameter">type</replaceable> is
- either <quote>blank</quote> or <quote>pattern</quote>.
- </para>
- <para>
- There is a third (advanced) type, called <quote>auto</quote>. It is <emphasis>NOT</emphasis> to be
- used in <literal>set-image-blocker</literal>, but meant for use from <link linkend="filter-file">filters</link>.
- Auto will select the type of image that would have applied to the referring page, had it been an image.
- </para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term>Example usage:</term>
- <listitem>
- <para>
- Built-in pattern:
- </para>
- <para>
- <screen>+set-image-blocker{pattern}</screen>
- </para>
- <para>
- Redirect to the BSD daemon:
- </para>
- <para>
- <screen>+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</screen>
- </para>
- <para>
- Redirect to the built-in pattern for better caching:
- </para>
- <para>
- <screen>+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</screen>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-</sect3>
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect3>
-<title>Summary</title>
-<para>
- Note that many of these actions have the potential to cause a page to
- misbehave, possibly even not to display at all. There are many ways
- a site designer may choose to design his site, and what HTTP header
- content, and other criteria, he may depend on. There is no way to have hard
- and fast rules for all sites. See the <link
- linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
- actions.
-</para>
-</sect3>
-</sect2>
-
-<!-- ~~~~~ New section ~~~~~ -->
-<sect2 id="aliases">
-<title>Aliases</title>
-<para>
- Custom <quote>actions</quote>, known to <application>Privoxy</application>
- as <quote>aliases</quote>, can be defined by combining other actions.
- These can in turn be invoked just like the built-in actions.
- Currently, an alias name can contain any character except space, tab,
- <quote>=</quote>,
- <quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
- recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
- <quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
- Alias names are not case sensitive, and are not required to start with a
- <quote>+</quote> or <quote>-</quote> sign, since they are merely textually
- expanded.
-</para>
-<para>
- Aliases can be used throughout the actions file, but they <emphasis>must be
- defined in a special section at the top of the file!</emphasis>
- And there can only be one such section per actions file. Each actions file may
- have its own alias section, and the aliases defined in it are only visible
- within that file.
-</para>
-<para>
- There are two main reasons to use aliases: One is to save typing for frequently
- used combinations of actions, the other one is a gain in flexibility: If you
- decide once how you want to handle shops by defining an alias called
- <quote>shop</quote>, you can later change your policy on shops in
- <emphasis>one</emphasis> place, and your changes will take effect everywhere
- in the actions file where the <quote>shop</quote> alias is used. Calling aliases
- by their purpose also makes your actions files more readable.
-</para>
-<para>
- Currently, there is one big drawback to using aliases, though:
- <application>Privoxy</application>'s built-in web-based action file
- editor honors aliases when reading the actions files, but it expands
- them before writing. So the effects of your aliases are of course preserved,
- but the aliases themselves are lost when you edit sections that use aliases
- with it.
-</para>
-
-<para>
- Now let's define some aliases...
-</para>
-
-<para>
- <screen>
- # Useful custom aliases we can use later.
- #
- # Note the (required!) section header line and that this section
- # must be at the top of the actions file!
- #
- {{alias}}
-
- # These aliases just save typing later:
- # (Note that some already use other aliases!)
- #
- +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
- -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
- +block-as-image = +block{Blocked image.} +handle-as-image
- allow-all-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
-
- # These aliases define combinations of actions
- # that are useful for certain types of sites:
- #
- fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link> -<link linkend="PREVENT-COMPRESSION">prevent-compression</link>
-
- shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link>
-
- # Short names for other aliases, for really lazy people ;-)
- #
- c0 = +crunch-all-cookies
- c1 = -crunch-all-cookies</screen>
-</para>
-
-<para>
- ...and put them to use. These sections would appear in the lower part of an
- actions file and define exceptions to the default actions (as specified further
- up for the <quote>/</quote> pattern):
-</para>
-
-<para>
- <screen>
- # These sites are either very complex or very keen on
- # user data and require minimal interference to work:
- #
- {fragile}
- .office.microsoft.com
- .windowsupdate.microsoft.com
- # Gmail is really mail.google.com, not gmail.com
- mail.google.com
-
- # Shopping sites:
- # Allow cookies (for setting and retrieving your customer data)
- #
- {shop}
- .quietpc.com
- .worldpay.com # for quietpc.com
- mybank.example.com
-
- # These shops require pop-ups:
- #
- {-filter{all-popups} -filter{unsolicited-popups}}
- .dabs.com
- .overclockers.co.uk</screen>
-</para>
-
-<para>
- Aliases like <quote>shop</quote> and <quote>fragile</quote> are typically used for
- <quote>problem</quote> sites that require more than one action to be disabled
- in order to function properly.
-</para>
-</sect2>
-<!--
-hal stop here
--->
-<!-- ~~~~~ New section ~~~~~ -->
-<sect2 id="act-examples">
-<title>Actions Files Tutorial</title>
-<para>
- The above chapters have shown <link linkend="actions-file">which actions files
- there are and how they are organized</link>, how actions are <link
- linkend="actions">specified</link> and <link linkend="actions-apply">applied
- to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
- define and use <link linkend="aliases">aliases</link>. Now, let's look at an
- example <filename>match-all.action</filename>, <filename>default.action</filename>
- and <filename>user.action</filename> file and see how all these pieces come together:
-</para>
-
-<sect3>
-<title>match-all.action</title>
-<para>
- Remember <emphasis>all actions are disabled when matching starts</emphasis>,
- so we have to explicitly enable the ones we want.
-</para>
-
-<para>
- While the <filename>match-all.action</filename> file only contains a
- single section, it is probably the most important one. It has only one
- pattern, <quote><literal>/</literal></quote>, but this pattern
- <link linkend="af-patterns">matches all URLs</link>. Therefore, the set of
- actions used in this <quote>default</quote> section <emphasis>will
- be applied to all requests as a start</emphasis>. It can be partly or
- wholly overridden by other actions files like <filename>default.action</filename>
- and <filename>user.action</filename>, but it will still be largely responsible
- for your overall browsing experience.
-</para>
-
-<para>
- Again, at the start of matching, all actions are disabled, so there is
- no need to disable any actions here. (Remember: a <quote>+</quote>
- preceding the action name enables the action, a <quote>-</quote> disables!).
- Also note how this long line has been made more readable by splitting it into
- multiple lines with line continuation.
-</para>
-
-<para>
- <screen>
-{ \
- +<link linkend="CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</link> \
- +<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
- +<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
-}
-/ # Match all URLs
- </screen>
-</para>
-
-<para>
- The default behavior is now set.
-</para>
-</sect3>
-
-<sect3>
-<title>default.action</title>
-
-<para>
- If you aren't a developer, there's no need for you to edit the
- <filename>default.action</filename> file. It is maintained by
- the &my-app; developers and if you disagree with some of the
- sections, you should overrule them in your <filename>user.action</filename>.
-</para>
-
-<para>
- Understanding the <filename>default.action</filename> file can
- help you with your <filename>user.action</filename>, though.
-</para>
-
-<para>
- The first section in this file is a special section for internal use
- that prevents older &my-app; versions from reading the file:
-</para>
-
-<para>
- <screen>
-##########################################################################
-# Settings -- Don't change! For internal Privoxy use ONLY.
-##########################################################################
-{{settings}}
-for-privoxy-version=3.0.11</screen>
-</para>
-
-<para>
- After that comes the (optional) alias section. We'll use the example
- section from the above <link linkend="aliases">chapter on aliases</link>,
- that also explains why and how aliases are used:
-</para>
-
-<para>
- <screen>
-##########################################################################
-# Aliases
-##########################################################################
-{{alias}}
-
- # These aliases just save typing later:
- # (Note that some already use other aliases!)
- #
- +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
- -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
- +block-as-image = +block{Blocked image.} +handle-as-image
- mercy-for-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
-
- # These aliases define combinations of actions
- # that are useful for certain types of sites:
- #
- fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link>
- shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link></screen>
-</para>
-
-<para>
- The first of our specialized sections is concerned with <quote>fragile</quote>
- sites, i.e. sites that require minimum interference, because they are either
- very complex or very keen on tracking you (and have mechanisms in place that
- make them unusable for people who avoid being tracked). We will simply use
- our pre-defined <literal>fragile</literal> alias instead of stating the list
- of actions explicitly:
-</para>
-
-<para>
- <screen>
-##########################################################################
-# Exceptions for sites that'll break under the default action set:
-##########################################################################
-
-# "Fragile" Use a minimum set of actions for these sites (see alias above):
-#
-{ fragile }
-.office.microsoft.com # surprise, surprise!
-.windowsupdate.microsoft.com
-mail.google.com</screen>
-</para>
-
-<para>
- Shopping sites are not as fragile, but they typically
- require cookies to log in, and pop-up windows for shopping
- carts or item details. Again, we'll use a pre-defined alias:
-</para>
-
-<para>
- <screen>
-# Shopping sites:
-#
-{ shop }
-.quietpc.com
-.worldpay.com # for quietpc.com
-.jungle.com
-.scan.co.uk</screen>
-</para>
-
-<para>
- The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
- action, which may have been enabled in <filename>match-all.action</filename>,
- breaks some sites. So disable it for popular sites where we know it misbehaves:
-</para>
-
-<para>
- <screen>
-{ -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
-login.yahoo.com
-edit.*.yahoo.com
-.google.com
-.altavista.com/.*(like|url|link):http
-.altavista.com/trans.*urltext=http
-.nytimes.com</screen>
-</para>
-
-<para>
- It is important that <application>Privoxy</application> knows which
- URLs belong to images, so that <emphasis>if</emphasis> they are to
- be blocked, a substitute image can be sent, rather than an HTML page.
- Contacting the remote site to find out is not an option, since it
- would destroy the loading time advantage of banner blocking, and it
- would feed the advertisers information about you. We can mark any
- URL as an image with the <literal><link
- linkend="handle-as-image">handle-as-image</link></literal> action,
- and marking all URLs that end in a known image file extension is a
- good start:
-</para>
-
-<para>
- <screen>
-##########################################################################
-# Images:
-##########################################################################
-
-# Define which file types will be treated as images, in case they get
-# blocked further down this file:
-#
-{ +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
-/.*\.(gif|jpe?g|png|bmp|ico)$</screen>
-</para>
-
-<para>
- And then there are known banner sources. They often use scripts to
- generate the banners, so it won't be visible from the URL that the
- request is for an image. Hence we block them <emphasis>and</emphasis>
- mark them as images in one go, with the help of our
- <literal>+block-as-image</literal> alias defined above. (We could of
- course just as well use <literal>+<link linkend="block">block</link>
- +<link linkend="handle-as-image">handle-as-image</link></literal> here.)
- Remember that the type of the replacement image is chosen by the
- <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
- action. Since all URLs have matched the default section with its
- <literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
- action before, it still applies and needn't be repeated:
-</para>
-
-<para>
- <screen>
-# Known ad generators:
-#
-{ +block-as-image }
-ar.atwola.com
-.ad.doubleclick.net
-.ad.*.doubleclick.net
-.a.yimg.com/(?:(?!/i/).)*$
-.a[0-9].yimg.com/(?:(?!/i/).)*$
-bs*.gsanet.com
-.qkimg.net</screen>
-</para>
-
-<para>
- One of the most important jobs of <application>Privoxy</application>
- is to block banners. Many of these can be <quote>blocked</quote>
- by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
- action, which we enabled above, and which deletes the references to banner
- images from the pages while they are loaded, so the browser doesn't request
- them anymore, and hence they don't need to be blocked here. But this naturally
- doesn't catch all banners, and some people choose not to use filters, so we
- need a comprehensive list of patterns for banner URLs here, and apply the
- <literal><link linkend="block">block</link></literal> action to them.
-</para>
-<para>
- First comes many generic patterns, which do most of the work, by
- matching typical domain and path name components of banners. Then comes
- a list of individual patterns for specific sites, which is omitted here
- to keep the example short:
-</para>
-
-<para>
- <screen>
-##########################################################################
-# Block these fine banners:
-##########################################################################
-{ <link linkend="BLOCK">+block{Banner ads.}</link> }
-
-# Generic patterns:
-#
-ad*.
-.*ads.
-banner?.
-count*.
-/.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
-/(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
-
-# Site-specific patterns (abbreviated):
-#
-.hitbox.com</screen>
-</para>
-
-<para>
- It's quite remarkable how many advertisers actually call their banner
- servers ads.<replaceable>company</replaceable>.com, or call the directory
- in which the banners are stored simply <quote>banners</quote>. So the above
- generic patterns are surprisingly effective.
-</para>
-<para>
- But being very generic, they necessarily also catch URLs that we don't want
- to block. The pattern <literal>.*ads.</literal> e.g. catches
- <quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
- but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
- <quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
- well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
- section above.
-</para>
-<para>
- Note that these are exceptions to exceptions from the default! Consider the URL
- <quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
- so it wouldn't get blocked. Then comes the defaults section, which matches the
- URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
- action once again. Then it matches <literal>.*ads.</literal>, an exception to the
- general non-blocking policy, and suddenly
- <literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
- <literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
- applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
- with no <literal><link linkend="BLOCK">block</link></literal> action applying.
-</para>
-
-<para>
- <screen>
-##########################################################################
-# Save some innocent victims of the above generic block patterns:
-##########################################################################
-
-# By domain:
-#
-{ -<link linkend="BLOCK">block</link> }
-adv[io]*. # (for advogato.org and advice.*)
-adsl. # (has nothing to do with ads)
-adobe. # (has nothing to do with ads either)
-ad[ud]*. # (adult.* and add.*)
-.edu # (universities don't host banners (yet!))
-.*loads. # (downloads, uploads etc)
-
-# By path:
-#
-/.*loads/
-
-# Site-specific:
-#
-www.globalintersec.com/adv # (adv = advanced)
-www.ugu.com/sui/ugu/adv</screen>
-</para>
-
-<para>
- Filtering source code can have nasty side effects,
- so make an exception for our friends at sourceforge.net,
- and all paths with <quote>cvs</quote> in them. Note that
- <literal>-<link linkend="FILTER">filter</link></literal>
- disables <emphasis>all</emphasis> filters in one fell swoop!
-</para>
-
-<para>
- <screen>
-# Don't filter code!
-#
-{ -<link linkend="FILTER">filter</link> }
-/(.*/)?cvs
-bugzilla.
-developer.
-wiki.
-.sourceforge.net</screen>
-</para>
-
-<para>
- The actual <filename>default.action</filename> is of course much more
- comprehensive, but we hope this example made clear how it works.
-</para>
-
-</sect3>
-
-<sect3><title>user.action</title>
-
-<para>
- So far we are painting with a broad brush by setting general policies,
- which would be a reasonable starting point for many people. Now,
- you might want to be more specific and have customized rules that
- are more suitable to your personal habits and preferences. These would
- be for narrowly defined situations like your ISP or your bank, and should
- be placed in <filename>user.action</filename>, which is parsed after all other
- actions files and hence has the last word, over-riding any previously
- defined actions. <filename>user.action</filename> is also a
- <emphasis>safe</emphasis> place for your personal settings, since
- <filename>default.action</filename> is actively maintained by the
- <application>Privoxy</application> developers and you'll probably want
- to install updated versions from time to time.
-</para>
-
-<para>
- So let's look at a few examples of things that one might typically do in
- <filename>user.action</filename>:
-</para>
-
-
-<!-- brief sample user.action here -->
-
-<para>
- <screen>
-# My user.action file. <fred@example.com></screen>
-</para>
-
-<para>
- As <link linkend="aliases">aliases</link> are local to the actions
- file that they are defined in, you can't use the ones from
- <filename>default.action</filename>, unless you repeat them here:
-</para>
-
-<para>
- <screen>
-# Aliases are local to the file they are defined in.
-# (Re-)define aliases for this file:
-#
-{{alias}}
-#
-# These aliases just save typing later, and the alias names should
-# be self explanatory.
-#
-+crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
--crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
- allow-all-cookies = -crunch-all-cookies -session-cookies-only
- allow-popups = -filter{all-popups}
-+block-as-image = +block{Blocked as image.} +handle-as-image
--block-as-image = -block
-
-# These aliases define combinations of actions that are useful for
-# certain types of sites:
-#
-fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
-shop = -crunch-all-cookies allow-popups
-
-# Allow ads for selected useful free sites:
-#
-allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
-
-# Alias for specific file types that are text, but might have conflicting
-# MIME types. We want the browser to force these to be text documents.
-handle-as-text = -<link linkend="FILTER">filter</link> +-<link linkend="content-type-overwrite">content-type-overwrite{text/plain}</link> +-<link linkend="FORCE-TEXT-MODE">force-text-mode</link> -<link linkend="HIDE-CONTENT-DISPOSITION">hide-content-disposition</link></screen>
-
-</para>
-
-<para>
- Say you have accounts on some sites that you visit regularly, and
- you don't want to have to log in manually each time. So you'd like
- to allow persistent cookies for these sites. The
- <literal>allow-all-cookies</literal> alias defined above does exactly
- that, i.e. it disables crunching of cookies in any direction, and the
- processing of cookies to make them only temporary.
-</para>
-
-<para>
- <screen>
-{ allow-all-cookies }
- sourceforge.net
- .yahoo.com
- .msdn.microsoft.com
- .redhat.com</screen>
-</para>
-
-<para>
- Your bank is allergic to some filter, but you don't know which, so you disable them all:
-</para>
-
-<para>
- <screen>
-{ -<link linkend="FILTER">filter</link> }
- .your-home-banking-site.com</screen>
-</para>
-
-<para>
- Some file types you may not want to filter for various reasons:
-</para>
-
-<para>
- <screen>
-# Technical documentation is likely to contain strings that might
-# erroneously get altered by the JavaScript-oriented filters:
-#
-.tldp.org
-/(.*/)?selfhtml/
-
-# And this stupid host sends streaming video with a wrong MIME type,
-# so that Privoxy thinks it is getting HTML and starts filtering:
-#
-stupid-server.example.com/</screen>
-</para>
-
-<para>
- Example of a simple <link linkend="BLOCK">block</link> action. Say you've
- seen an ad on your favourite page on example.com that you want to get rid of.
- You have right-clicked the image, selected <quote>copy image location</quote>
- and pasted the URL below while removing the leading http://, into a
- <literal>{ +block{} }</literal> section. Note that <literal>{ +handle-as-image
- }</literal> need not be specified, since all URLs ending in
- <literal>.gif</literal> will be tagged as images by the general rules as set
- in default.action anyway:
-</para>
-
-<para>
- <screen>
-{ +<link linkend="BLOCK">block</link>{Nasty ads.} }
- www.example.com/nasty-ads/sponsor\.gif
- another.example.net/more/junk/here/</screen>
-</para>
-
-<para>
- The URLs of dynamically generated banners, especially from large banner
- farms, often don't use the well-known image file name extensions, which
- makes it impossible for <application>Privoxy</application> to guess
- the file type just by looking at the URL.
- You can use the <literal>+block-as-image</literal> alias defined above for
- these cases.
- Note that objects which match this rule but then turn out NOT to be an
- image are typically rendered as a <quote>broken image</quote> icon by the
- browser. Use cautiously.
-</para>
-
-<para>
- <screen>
-{ +block-as-image }
- .doubleclick.net
- .fastclick.net
- /Realmedia/ads/
- ar.atwola.com/</screen>
-</para>
-
-<para>
- Now you noticed that the default configuration breaks Forbes Magazine,
- but you were too lazy to find out which action is the culprit, and you
- were again too lazy to give <link linkend="contact">feedback</link>, so
- you just used the <literal>fragile</literal> alias on the site, and
- -- <emphasis>whoa!</emphasis> -- it worked. The <literal>fragile</literal>
- aliases disables those actions that are most likely to break a site. Also,
- good for testing purposes to see if it is <application>Privoxy</application>
- that is causing the problem or not. We later find other regular sites
- that misbehave, and add those to our personalized list of troublemakers:
-</para>
-
-<para>
-<screen>
-{ fragile }
- .forbes.com
- webmail.example.com
- .mybank.com</screen>
-</para>
-
-<para>
- You like the <quote>fun</quote> text replacements in <filename>default.filter</filename>,
- but it is disabled in the distributed actions file.
- So you'd like to turn it on in your private,
- update-safe config, once and for all:
-</para>
-
-<para>
-<screen>
-{ +<link linkend="filter-fun">filter{fun}</link> }
- / # For ALL sites!</screen>
-</para>
-
-<para>
- Note that the above is not really a good idea: There are exceptions
- to the filters in <filename>default.action</filename> for things that
- really shouldn't be filtered, like code on CVS->Web interfaces. Since
- <filename>user.action</filename> has the last word, these exceptions
- won't be valid for the <quote>fun</quote> filtering specified here.
-</para>
-
-<para>
- You might also worry about how your favourite free websites are
- funded, and find that they rely on displaying banner advertisements
- to survive. So you might want to specifically allow banners for those
- sites that you feel provide value to you:
-</para>
+ <para>
+ <anchor id="filter-all-popups">
+ <screen>+filter{all-popups} # Kill all popups in JavaScript and HTML.</screen>
+ </para>
+ <para>
+ <anchor id="filter-img-reorder">
+ <screen>+filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.</screen>
+ </para>
+ <para>
+ <anchor id="filter-banners-by-size">
+ <screen>+filter{banners-by-size} # Kill banners by size.</screen>
+ </para>
+ <para>
+ <anchor id="filter-banners-by-link">
+ <screen>+filter{banners-by-link} # Kill banners by their links to known clicktrackers.</screen>
+ </para>
+ <para>
+ <anchor id="filter-webbugs">
+ <screen>+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).</screen>
+ </para>
+ <para>
+ <anchor id="filter-tiny-textforms">
+ <screen>+filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.</screen>
+ </para>
+ <para>
+ <anchor id="filter-jumping-windows">
+ <screen>+filter{jumping-windows} # Prevent windows from resizing and moving themselves.</screen>
+ </para>
+ <para>
+ <anchor id="filter-frameset-borders">
+ <screen>+filter{frameset-borders} # Give frames a border and make them resizable.</screen>
+ </para>
+ <para>
+ <anchor id="filter-iframes">
+ <screen>+filter{iframes} # Removes all detected iframes. Should only be enabled for individual sites.</screen>
+ </para>
+ <para>
+ <anchor id="filter-demoronizer">
+ <screen>+filter{demoronizer} # Fix MS's non-standard use of standard charsets.</screen>
+ </para>
+ <para>
+ <anchor id="filter-shockwave-flash">
+ <screen>+filter{shockwave-flash} # Kill embedded Shockwave Flash objects.</screen>
+ </para>
+ <para>
+ <anchor id="filter-quicktime-kioskmode">
+ <screen>+filter{quicktime-kioskmode} # Make Quicktime movies saveable.</screen>
+ </para>
+ <para>
+ <anchor id="filter-fun">
+ <screen>+filter{fun} # Text replacements for subversive browsing fun!</screen>
+ </para>
+ <para>
+ <anchor id="filter-crude-parental">
+ <screen>+filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.</screen>
+ </para>
+ <para>
+ <anchor id="filter-ie-exploits">
+ <screen>+filter{ie-exploits} # Disable some known Internet Explorer bug exploits.</screen>
+ </para>
+ <para>
+ <anchor id="filter-site-specifics">
+ <screen>+filter{site-specifics} # Cure for site-specific problems. Don't apply generally!</screen>
+ </para>
+ <para>
+ <anchor id="filter-no-ping">
+ <screen>+filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.</screen>
+ </para>
+ <para>
+ <anchor id="filter-google">
+ <screen>+filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.</screen>
+ </para>
+ <para>
+ <anchor id="filter-yahoo">
+ <screen>+filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.</screen>
+ </para>
+ <para>
+ <anchor id="filter-msn">
+ <screen>+filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.</screen>
+ </para>
+ <para>
+ <anchor id="filter-blogspot">
+ <screen>+filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
-<screen>
-{ allow-ads }
- .sourceforge.net
- .slashdot.org
- .osdn.net</screen>
-</para>
-<para>
- Note that <literal>allow-ads</literal> has been aliased to
- <literal>-<link linkend="block">block</link></literal>,
- <literal>-<link linkend="filter-banners-by-size">filter{banners-by-size}</link></literal>, and
- <literal>-<link linkend="filter-banners-by-link">filter{banners-by-link}</link></literal> above.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="force-text-mode">
+<title>force-text-mode</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Force <application>Privoxy</application> to treat a document as if it was in some kind of <emphasis>text</emphasis> format. </para>
+ </listitem>
+ </varlistentry>
-<para>
- Invoke another alias here to force an over-ride of the MIME type <literal>
- application/x-sh</literal> which typically would open a download type
- dialog. In my case, I want to look at the shell script, and then I can save
- it should I choose to.
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Declares a document as text, even if the <quote>Content-Type:</quote> isn't detected as such.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
-<screen>
-{ handle-as-text }
- /.*\.sh$</screen>
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Boolean.</para>
+ </listitem>
+ </varlistentry>
-<para>
- <filename>user.action</filename> is generally the best place to define
- exceptions and additions to the default policies of
- <filename>default.action</filename>. Some actions are safe to have their
- default policies set here though. So let's set a default policy to have a
- <quote>blank</quote> image as opposed to the checkerboard pattern for
- <emphasis>ALL</emphasis> sites. <quote>/</quote> of course matches all URL
- paths and patterns:
-</para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ N/A
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
-<screen>
-{ +<link linkend="set-image-blocker">set-image-blocker{blank}</link> }
-/ # ALL sites</screen>
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ As explained <literal><link linkend="filter">above</link></literal>,
+ <application>Privoxy</application> tries to only filter files that are
+ in some kind of text format. The same restrictions apply to
+ <literal><link linkend="content-type-overwrite">content-type-overwrite</link></literal>.
+ <literal>force-text-mode</literal> declares a document as text,
+ without looking at the <quote>Content-Type:</quote> first.
+ </para>
+ <warning>
+ <para>
+ Think twice before activating this action. Filtering binary data
+ with regular expressions can cause file damage.
+ </para>
+ </warning>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen>
++force-text-mode
+ </screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
</sect3>
-</sect2>
-
-<!-- ~ End section ~ -->
-</sect1>
-
-<!-- ~ End section ~ -->
-
-<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
-
-<sect1 id="filter-file">
-<title>Filter Files</title>
-<para>
- On-the-fly text substitutions need
- to be defined in a <quote>filter file</quote>. Once defined, they
- can then be invoked as an <quote>action</quote>.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="forward-override">
+<title>forward-override</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Change the forwarding settings based on User-Agent or request origin</para>
+ </listitem>
+ </varlistentry>
-<para>
- &my-app; supports three different filter actions:
- <literal><link linkend="filter">filter</link></literal> to
- rewrite the content that is send to the client,
- <literal><link linkend="client-header-filter">client-header-filter</link></literal>
- to rewrite headers that are send by the client, and
- <literal><link linkend="server-header-filter">server-header-filter</link></literal>
- to rewrite headers that are send by the server.
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Overrules the forward directives in the configuration file.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- &my-app; also supports two tagger actions:
- <literal><link linkend="client-header-tagger">client-header-tagger</link></literal>
- and
- <literal><link linkend="server-header-tagger">server-header-tagger</link></literal>.
- Taggers and filters use the same syntax in the filter files, the difference
- is that taggers don't modify the text they are filtering, but use a rewritten
- version of the filtered text as tag. The tags can then be used to change the
- applying actions through sections with <link linkend="tag-pattern">tag-patterns</link>.
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <itemizedlist>
+ <listitem>
+ <para><quote>forward .</quote> to use a direct connection without any additional proxies.</para>
+ </listitem>
+ <listitem>
+ <para>
+ <quote>forward 127.0.0.1:8123</quote> to use the HTTP proxy listening at 127.0.0.1 port 8123.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <quote>forward-socks4a 127.0.0.1:9050 .</quote> to use the socks4a proxy listening at
+ 127.0.0.1 port 9050. Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote>
+ to use a socks4 connection (with local DNS resolution) instead, use <quote>forward-socks5</quote>
+ for socks5 connections (with remote DNS resolution).
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <quote>forward-socks4a 127.0.0.1:9050 proxy.example.org:8000</quote> to use the socks4a proxy
+ listening at 127.0.0.1 port 9050 to reach the HTTP proxy listening at proxy.example.org port 8000.
+ Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote> to use a socks4 connection
+ (with local DNS resolution) instead, use <quote>forward-socks5</quote>
+ for socks5 connections (with remote DNS resolution).
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <quote>forward-webserver 127.0.0.1:80</quote> to use the HTTP
+ server listening at 127.0.0.1 port 80 without adjusting the
+ request headers.
+ </para>
+ <para>
+ This makes it more convenient to use Privoxy to make
+ existing websites available as onion services as well.
+ </para>
+ <para>
+ Many websites serve content with hardcoded URLs and
+ can't be easily adjusted to change the domain based
+ on the one used by the client.
+ </para>
+ <para>
+ Putting Privoxy between Tor and the webserver (or an stunnel
+ that forwards to the webserver) allows to rewrite headers and
+ content to make client and server happy at the same time.
+ </para>
+ <para>
+ Using Privoxy for webservers that are only reachable through
+ onion addresses and whose location is supposed to be secret
+ is not recommended and should not be necessary anyway.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </listitem>
+ </varlistentry>
-<para>
- Multiple filter files can be defined through the <literal> <link
- linkend="filterfile">filterfile</link></literal> config directive. The filters
- as supplied by the developers are located in
- <filename>default.filter</filename>. It is recommended that any locally
- defined or modified filters go in a separately defined file such as
- <filename>user.filter</filename>.
- </para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ This action takes parameters similar to the
+ <link linkend="forwarding">forward</link> directives in the configuration
+ file, but without the URL pattern. It can be used as replacement, but normally it's only
+ used in cases where matching based on the request URL isn't sufficient.
+ </para>
+ <warning>
+ <para>
+ Please read the description for the <link linkend="forwarding">forward</link> directives before
+ using this action. Forwarding to the wrong people will reduce your privacy and increase the
+ chances of man-in-the-middle attacks.
+ </para>
+ <para>
+ If the ports are missing or invalid, default values will be used. This might change
+ in the future and you shouldn't rely on it. Otherwise incorrect syntax causes Privoxy
+ to exit. Due to design limitations, invalid parameter syntax isn't detected until the
+ action is used the first time.
+ </para>
+ <para>
+ Use the <ulink url="http://config.privoxy.org/show-url-info">show-url-info CGI page</ulink>
+ to verify that your forward settings do what you thought the do.
+ </para>
+ </warning>
+ </listitem>
+ </varlistentry>
-<para>
- Common tasks for content filters are to eliminate common annoyances in
- HTML and JavaScript, such as pop-up windows,
- exit consoles, crippled windows without navigation tools, the
- infamous <BLINK> tag etc, to suppress images with certain
- width and height attributes (standard banner sizes or web-bugs),
- or just to have fun.
-</para>
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen>
+# Use an ssh tunnel for requests previously tagged as
+# <quote>User-Agent: fetch libfetch/2.0</quote> and make sure
+# resuming downloads continues to work.
+#
+# This way you can continue to use Tor for your normal browsing,
+# without overloading the Tor network with your FreeBSD ports updates
+# or downloads of bigger files like ISOs.
+#
+# Note that HTTP headers are easy to fake and therefore their
+# values are as (un)trustworthy as your clients and users.
+{+forward-override{forward-socks5 10.0.0.2:2222 .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+}
+TAG:^User-Agent: fetch libfetch/2\.0$
+ </screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
- Enabled content filters are applied to any content whose
- <quote>Content Type</quote> header is recognised as a sign
- of text-based content, with the exception of <literal>text/plain</literal>.
- Use the <link linkend="FORCE-TEXT-MODE">force-text-mode</link> action
- to also filter other content.
-</para>
-<para>
- Substitutions are made at the source level, so if you want to <quote>roll
- your own</quote> filters, you should first be familiar with HTML syntax,
- and, of course, regular expressions.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="handle-as-empty-document">
+<title>handle-as-empty-document</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Mark URLs that should be replaced by empty documents <emphasis>if they get blocked</emphasis></para>
+ </listitem>
+ </varlistentry>
-<para>
- Just like the <link linkend="actions-file">actions files</link>, the
- filter file is organized in sections, which are called <emphasis>filters</emphasis>
- here. Each filter consists of a heading line, that starts with one of the
- <emphasis>keywords</emphasis> <literal>FILTER:</literal>,
- <literal>CLIENT-HEADER-FILTER:</literal> or <literal>SERVER-HEADER-FILTER:</literal>
- followed by the filter's <emphasis>name</emphasis>, and a short (one line)
- <emphasis>description</emphasis> of what it does. Below that line
- come the <emphasis>jobs</emphasis>, i.e. lines that define the actual
- text substitutions. By convention, the name of a filter
- should describe what the filter <emphasis>eliminates</emphasis>. The
- comment is used in the <ulink url="http://config.privoxy.org/">web-based
- user interface</ulink>.
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ This action alone doesn't do anything noticeable. It just marks URLs.
+ If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
+ the presence or absence of this mark decides whether an HTML <quote>BLOCKED</quote>
+ page, or an empty document will be sent to the client as a substitute for the blocked content.
+ The <emphasis>empty</emphasis> document isn't literally empty, but actually contains a single space.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- Once a filter called <replaceable>name</replaceable> has been defined
- in the filter file, it can be invoked by using an action of the form
- +<literal><link linkend="filter">filter</link>{<replaceable>name</replaceable>}</literal>
- in any <link linkend="actions-file">actions file</link>.
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Boolean.</para>
+ </listitem>
+ </varlistentry>
-<para>
- Filter definitions start with a header line that contains the filter
- type, the filter name and the filter description.
- A content filter header line for a filter called <quote>foo</quote> could look
- like this:
-</para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ N/A
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <screen>FILTER: foo Replace all "foo" with "bar"</screen>
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Some browsers complain about syntax errors if JavaScript documents
+ are blocked with <application>Privoxy's</application>
+ default HTML page; this option can be used to silence them.
+ And of course this action can also be used to eliminate the &my-app;
+ BLOCKED message in frames.
+ </para>
+ <para>
+ The content type for the empty document can be specified with
+ <literal><link linkend="content-type-overwrite">content-type-overwrite{}</link></literal>,
+ but usually this isn't necessary.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- Below that line, and up to the next header line, come the jobs that
- define what text replacements the filter executes. They are specified
- in a syntax that imitates <ulink url="http://www.perl.org/">Perl</ulink>'s
- <literal>s///</literal> operator. If you are familiar with Perl, you
- will find this to be quite intuitive, and may want to look at the
- PCRS documentation for the subtle differences to Perl behaviour. Most
- notably, the non-standard option letter <literal>U</literal> is supported,
- which turns the default to ungreedy matching.
-</para>
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen># Block all documents on example.org that end with ".js",
+# but send an empty document instead of the usual HTML message.
+{+block{Blocked JavaScript} +handle-as-empty-document}
+example.org/.*\.js$
+ </screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
- If you are new to
- <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
- Expressions</quote></ulink>, you might want to take a look at
- the <link linkend="regex">Appendix on regular expressions</link>, and
- see the <ulink url="http://perldoc.perl.org/perlre.html">Perl
- manual</ulink> for
- <ulink url="http://perldoc.perl.org/perlop.html">the
- <literal>s///</literal> operator's syntax</ulink> and <ulink
- url="http://perldoc.perl.org/perlre.html">Perl-style regular
- expressions</ulink> in general.
- The below examples might also help to get you started.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="handle-as-image">
+<title>handle-as-image</title>
-<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Mark URLs as belonging to images (so they'll be replaced by images <emphasis>if they do get blocked</emphasis>, rather than HTML pages)</para>
+ </listitem>
+ </varlistentry>
-<sect2><title>Filter File Tutorial</title>
-<para>
- Now, let's complete our <quote>foo</quote> content filter. We have already defined
- the heading, but the jobs are still missing. Since all it does is to replace
- <quote>foo</quote> with <quote>bar</quote>, there is only one (trivial) job
- needed:
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ This action alone doesn't do anything noticeable. It just marks URLs as images.
+ If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
+ the presence or absence of this mark decides whether an HTML <quote>blocked</quote>
+ page, or a replacement image (as determined by the <literal><link
+ linkend="set-image-blocker">set-image-blocker</link></literal> action) will be sent to the
+ client as a substitute for the blocked content.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <screen>s/foo/bar/</screen>
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Boolean.</para>
+ </listitem>
+ </varlistentry>
-<para>
- But wait! Didn't the comment say that <emphasis>all</emphasis> occurrences
- of <quote>foo</quote> should be replaced? Our current job will only take
- care of the first <quote>foo</quote> on each page. For global substitution,
- we'll need to add the <literal>g</literal> option:
-</para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ N/A
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <screen>s/foo/bar/g</screen>
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ The below generic example section is actually part of <filename>default.action</filename>.
+ It marks all URLs with well-known image file name extensions as images and should
+ be left intact.
+ </para>
+ <para>
+ Users will probably only want to use the handle-as-image action in conjunction with
+ <literal><link linkend="block">block</link></literal>, to block sources of banners, whose URLs don't
+ reflect the file type, like in the second example section.
+ </para>
+ <para>
+ Note that you cannot treat HTML pages as images in most cases. For instance, (in-line) ad
+ frames require an HTML page to be sent, or they won't display properly.
+ Forcing <literal>handle-as-image</literal> in this situation will not replace the
+ ad frame with an image, but lead to error messages.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- Our complete filter now looks like this:
-</para>
-<para>
- <screen>FILTER: foo Replace all "foo" with "bar"
-s/foo/bar/g</screen>
-</para>
+ <varlistentry>
+ <term>Example usage (sections):</term>
+ <listitem>
+ <para>
+ <screen># Generic image extensions:
+#
+{+handle-as-image}
+/.*\.(gif|jpg|jpeg|png|bmp|ico)$
-<para>
- Let's look at some real filters for more interesting examples. Here you see
- a filter that protects against some common annoyances that arise from JavaScript
- abuse. Let's look at its jobs one after the other:
-</para>
+# These don't look like images, but they're banners and should be
+# blocked as images:
+#
+{+block{Nasty banners.} +handle-as-image}
+nasty-banner-server.example.com/junk.cgi\?output=trash
+</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
- <screen>
-FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="hide-accept-language">
+<title>hide-accept-language</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Pretend to use different language settings.</para>
+ </listitem>
+ </varlistentry>
-# Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
-#
-s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg</screen>
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Deletes or replaces the <quote>Accept-Language:</quote> HTTP header in client requests.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- Following the header line and a comment, you see the job. Note that it uses
- <literal>|</literal> as the delimiter instead of <literal>/</literal>, because
- the pattern contains a forward slash, which would otherwise have to be escaped
- by a backslash (<literal>\</literal>).
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
-<para>
- Now, let's examine the pattern: it starts with the text <literal><script.*</literal>
- enclosed in parentheses. Since the dot matches any character, and <literal>*</literal>
- means: <quote>Match an arbitrary number of the element left of myself</quote>, this
- matches <quote><script</quote>, followed by <emphasis>any</emphasis> text, i.e.
- it matches the whole page, from the start of the first <script> tag.
-</para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ Keyword: <quote>block</quote>, or any user defined value.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- That's more than we want, but the pattern continues: <literal>document\.referrer</literal>
- matches only the exact string <quote>document.referrer</quote>. The dot needed to
- be <emphasis>escaped</emphasis>, i.e. preceded by a backslash, to take away its
- special meaning as a joker, and make it just a regular dot. So far, the meaning is:
- Match from the start of the first <script> tag in a the page, up to, and including,
- the text <quote>document.referrer</quote>, if <emphasis>both</emphasis> are present
- in the page (and appear in that order).
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Faking the browser's language settings can be useful to make a
+ foreign User-Agent set with
+ <literal><link linkend="hide-user-agent">hide-user-agent</link></literal>
+ more believable.
+ </para>
+ <para>
+ However some sites with content in different languages check the
+ <quote>Accept-Language:</quote> to decide which one to take by default.
+ Sometimes it isn't possible to later switch to another language without
+ changing the <quote>Accept-Language:</quote> header first.
+ </para>
+ <para>
+ Therefore it's a good idea to either only change the
+ <quote>Accept-Language:</quote> header to languages you understand,
+ or to languages that aren't wide spread.
+ </para>
+ <para>
+ Before setting the <quote>Accept-Language:</quote> header
+ to a rare language, you should consider that it helps to
+ make your requests unique and thus easier to trace.
+ If you don't plan to change this header frequently,
+ you should stick to a common language.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- But there's still more pattern to go. The next element, again enclosed in parentheses,
- is <literal>.*</script></literal>. You already know what <literal>.*</literal>
- means, so the whole pattern translates to: Match from the start of the first <script>
- tag in a page to the end of the last <script> tag, provided that the text
- <quote>document.referrer</quote> appears somewhere in between.
-</para>
+ <varlistentry>
+ <term>Example usage (section):</term>
+ <listitem>
+ <para>
+ <screen># Pretend to use Canadian language settings.
+{+hide-accept-language{en-ca} \
++hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
+}
+/ </screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
- This is still not the whole story, since we have ignored the options and the parentheses:
- The portions of the page matched by sub-patterns that are enclosed in parentheses, will be
- remembered and be available through the variables <literal>$1, $2, ...</literal> in
- the substitute. The <literal>U</literal> option switches to ungreedy matching, which means
- that the first <literal>.*</literal> in the pattern will only <quote>eat up</quote> all
- text in between <quote><script</quote> and the <emphasis>first</emphasis> occurrence
- of <quote>document.referrer</quote>, and that the second <literal>.*</literal> will
- only span the text up to the <emphasis>first</emphasis> <quote></script></quote>
- tag. Furthermore, the <literal>s</literal> option says that the match may span
- multiple lines in the page, and the <literal>g</literal> option again means that the
- substitution is global.
-</para>
-<para>
- So, to summarize, the pattern means: Match all scripts that contain the text
- <quote>document.referrer</quote>. Remember the parts of the script from
- (and including) the start tag up to (and excluding) the string
- <quote>document.referrer</quote> as <literal>$1</literal>, and the part following
- that string, up to and including the closing tag, as <literal>$2</literal>.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="hide-content-disposition">
+<title>hide-content-disposition</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Prevent download menus for content you prefer to view inside the browser.</para>
+ </listitem>
+ </varlistentry>
-<para>
- Now the pattern is deciphered, but wasn't this about substituting things? So
- lets look at the substitute: <literal>$1"Not Your Business!"$2</literal> is
- easy to read: The text remembered as <literal>$1</literal>, followed by
- <literal>"Not Your Business!"</literal> (<emphasis>including</emphasis>
- the quotation marks!), followed by the text remembered as <literal>$2</literal>.
- This produces an exact copy of the original string, with the middle part
- (the <quote>document.referrer</quote>) replaced by <literal>"Not Your
- Business!"</literal>.
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Deletes or replaces the <quote>Content-Disposition:</quote> HTTP header set by some servers.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- The whole job now reads: Replace <quote>document.referrer</quote> by
- <literal>"Not Your Business!"</literal> wherever it appears inside a
- <script> tag. Note that this job won't break JavaScript syntax,
- since both the original and the replacement are syntactically valid
- string objects. The script just won't have access to the referrer
- information anymore.
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
-<para>
- We'll show you two other jobs from the JavaScript taming department, but
- this time only point out the constructs of special interest:
-</para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ Keyword: <quote>block</quote>, or any user defined value.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <screen>
-# The status bar is for displaying link targets, not pointless blahblah
-#
-s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig</screen>
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Some servers set the <quote>Content-Disposition:</quote> HTTP header for
+ documents they assume you want to save locally before viewing them.
+ The <quote>Content-Disposition:</quote> header contains the file name
+ the browser is supposed to use by default.
+ </para>
+ <para>
+ In most browsers that understand this header, it makes it impossible to
+ <emphasis>just view</emphasis> the document, without downloading it first,
+ even if it's just a simple text file or an image.
+ </para>
+ <para>
+ Removing the <quote>Content-Disposition:</quote> header helps
+ to prevent this annoyance, but some browsers additionally check the
+ <quote>Content-Type:</quote> header, before they decide if they can
+ display a document without saving it first. In these cases, you have
+ to change this header as well, before the browser stops displaying
+ download menus.
+ </para>
+ <para>
+ It is also possible to change the server's file name suggestion
+ to another one, but in most cases it isn't worth the time to set
+ it up.
+ </para>
+ <para>
+ This action will probably be removed in the future,
+ use server-header filters instead.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <literal>\s</literal> stands for whitespace characters (space, tab, newline,
- carriage return, form feed), so that <literal>\s*</literal> means: <quote>zero
- or more whitespace</quote>. The <literal>?</literal> in <literal>.*?</literal>
- makes this matching of arbitrary text ungreedy. (Note that the <literal>U</literal>
- option is not set). The <literal>['"]</literal> construct means: <quote>a single
- <emphasis>or</emphasis> a double quote</quote>. Finally, <literal>\1</literal> is
- a back-reference to the first parenthesis just like <literal>$1</literal> above,
- with the difference that in the <emphasis>pattern</emphasis>, a backslash indicates
- a back-reference, whereas in the <emphasis>substitute</emphasis>, it's the dollar.
-</para>
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen># Disarm the download link in Sourceforge's patch tracker
+{ -filter \
+ +content-type-overwrite{text/plain}\
+ +hide-content-disposition{block} }
+ .sourceforge.net/tracker/download\.php</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
- So what does this job do? It replaces assignments of single- or double-quoted
- strings to the <quote>window.status</quote> object with a dummy assignment
- (using a variable name that is hopefully odd enough not to conflict with
- real variables in scripts). Thus, it catches many cases where e.g. pointless
- descriptions are displayed in the status bar instead of the link target when
- you move your mouse over links.
-</para>
-<para>
- <screen>
-# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
-#
-s/(<body [^>]*)onunload(.*>)/$1never$2/iU</screen>
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="hide-if-modified-since">
+<title>hide-if-modified-since</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Prevent yet another way to track the user's steps between sessions.</para>
+ </listitem>
+ </varlistentry>
-<para>
- Including the
- <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">OnUnload
- event binding</ulink> in the HTML DOM was a <emphasis>CRIME</emphasis>.
- When I close a browser window, I want it to close and die. Basta.
- This job replaces the <quote>onunload</quote> attribute in
- <quote><body></quote> tags with the dummy word <literal>never</literal>.
- Note that the <literal>i</literal> option makes the pattern matching
- case-insensitive. Also note that ungreedy matching alone doesn't always guarantee
- a minimal match: In the first parenthesis, we had to use <literal>[^>]*</literal>
- instead of <literal>.*</literal> to prevent the match from exceeding the
- <body> tag if it doesn't contain <quote>OnUnload</quote>, but the page's
- content does.
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Deletes the <quote>If-Modified-Since:</quote> HTTP client header or modifies its value.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- The last example is from the fun department:
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
-<para>
- <screen>
-FILTER: fun Fun text replacements
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ Keyword: <quote>block</quote>, or a user defined value that specifies a range of hours.
+ </para>
+ </listitem>
+ </varlistentry>
-# Spice the daily news:
-#
-s/microsoft(?!\.com)/MicroSuck/ig</screen>
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Removing this header is useful for filter testing, where you want to force a real
+ reload instead of getting status code <quote>304</quote>, which would cause the
+ browser to use a cached copy of the page.
+ </para>
+ <para>
+ Instead of removing the header, <literal>hide-if-modified-since</literal> can
+ also add or subtract a random amount of time to/from the header's value.
+ You specify a range of minutes where the random factor should be chosen from and
+ <application>Privoxy</application> does the rest. A negative value means
+ subtracting, a positive value adding.
+ </para>
+ <para>
+ Randomizing the value of the <quote>If-Modified-Since:</quote> makes
+ it less likely that the server can use the time as a cookie replacement,
+ but you will run into caching problems if the random range is too high.
+ </para>
+ <para>
+ It is a good idea to only use a small negative value and let
+ <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>
+ handle the greater changes.
+ </para>
+ <para>
+ It is also recommended to use this action together with
+ <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>,
+ otherwise it's more or less pointless.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- Note the <literal>(?!\.com)</literal> part (a so-called negative lookahead)
- in the job's pattern, which means: Don't match, if the string
- <quote>.com</quote> appears directly following <quote>microsoft</quote>
- in the page. This prevents links to microsoft.com from being trashed, while
- still replacing the word everywhere else.
-</para>
+ <varlistentry>
+ <term>Example usage (section):</term>
+ <listitem>
+ <para>
+ <screen># Let the browser revalidate but make tracking based on the time less likely.
+{+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
- <screen>
-# Buzzword Bingo (example for extended regex syntax)
-#
-s* industry[ -]leading \
-| cutting[ -]edge \
-| customer[ -]focused \
-| market[ -]driven \
-| award[ -]winning # Comments are OK, too! \
-| high[ -]performance \
-| solutions[ -]based \
-| unmatched \
-| unparalleled \
-| unrivalled \
-*<font color="red"><b>BINGO!</b></font> \
-*igx</screen>
-</para>
-<para>
- The <literal>x</literal> option in this job turns on extended syntax, and allows for
- e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="hide-from-header">
+<title>hide-from-header</title>
-<para>
- You get the idea?
-</para>
-</sect2>
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Keep your (old and ill) browser from telling web servers your email address</para>
+ </listitem>
+ </varlistentry>
-<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Deletes any existing <quote>From:</quote> HTTP header, or replaces it with the
+ specified string.
+ </para>
+ </listitem>
+ </varlistentry>
-<sect2 id="predefined-filters"><title>The Pre-defined Filters</title>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
-<!--
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ Keyword: <quote>block</quote>, or any user defined value.
+ </para>
+ </listitem>
+ </varlistentry>
- Note each filter is also listed in the +filter action section above. Please
- keep these listings in sync.
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ The keyword <quote>block</quote> will completely remove the header
+ (not to be confused with the <literal><link linkend="block">block</link></literal>
+ action).
+ </para>
+ <para>
+ Alternately, you can specify any value you prefer to be sent to the web
+ server. If you do, it is a matter of fairness not to use any address that
+ is actually used by a real person.
+ </para>
+ <para>
+ This action is rarely needed, as modern web browsers don't send
+ <quote>From:</quote> headers anymore.
+ </para>
+ </listitem>
+ </varlistentry>
--->
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen>+hide-from-header{block}</screen> or
+ <screen>+hide-from-header{spam-me-senseless@sittingduck.example.com}</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
-<para>
-The distribution <filename>default.filter</filename> file contains a selection of
-pre-defined filters for your convenience:
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="hide-referrer">
+<title>hide-referrer</title>
+<anchor id="hide-referer">
<variablelist>
<varlistentry>
- <term><emphasis>js-annoyances</emphasis></term>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Conceal which link you followed to get to a particular site</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Effect:</term>
<listitem>
<para>
- The purpose of this filter is to get rid of particularly annoying JavaScript abuse.
- To that end, it
+ Deletes the <quote>Referer:</quote> (sic) HTTP header from the client request,
+ or replaces it with a forged one.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
<itemizedlist>
<listitem>
- <para>
- replaces JavaScript references to the browser's referrer information
- with the string "Not Your Business!". This compliments the <literal><link
- linkend="hide-referrer">hide-referrer</link></literal> action on the content level.
- </para>
+ <para><quote>conditional-block</quote> to delete the header completely if the host has changed.</para>
</listitem>
<listitem>
- <para>
- removes the bindings to the DOM's
- <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">unload
- event</ulink> which we feel has no right to exist and is responsible for most <quote>exit consoles</quote>, i.e.
- nasty windows that pop up when you close another one.
- </para>
+ <para><quote>conditional-forge</quote> to forge the header if the host has changed.</para>
</listitem>
<listitem>
- <para>
- removes code that causes new windows to be opened with undesired properties, such as being
- full-screen, non-resizeable, without location, status or menu bar etc.
- </para>
+ <para><quote>block</quote> to delete the header unconditionally.</para>
+ </listitem>
+ <listitem>
+ <para><quote>forge</quote> to pretend to be coming from the homepage of the server we are talking to.</para>
+ </listitem>
+ <listitem>
+ <para>Any other string to set a user defined referrer.</para>
</listitem>
</itemizedlist>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ <literal>conditional-block</literal> is the only parameter,
+ that isn't easily detected in the server's log file. If it blocks the
+ referrer, the request will look like the visitor used a bookmark or
+ typed in the address directly.
</para>
<para>
- Use with caution. This is an aggressive filter, and can break sites that
- rely heavily on JavaScript.
+ Leaving the referrer unmodified for requests on the same host
+ allows the server owner to see the visitor's <quote>click path</quote>,
+ but in most cases she could also get that information by comparing
+ other parts of the log file: for example the User-Agent if it isn't
+ a very common one, or the user's IP address if it doesn't change between
+ different requests.
+ </para>
+ <para>
+ Always blocking the referrer, or using a custom one, can lead to
+ failures on servers that check the referrer before they answer any
+ requests, in an attempt to prevent their content from being
+ embedded or linked to elsewhere.
+ </para>
+ <para>
+ Both <literal>conditional-block</literal> and <literal>forge</literal>
+ will work with referrer checks, as long as content and valid referring page
+ are on the same host. Most of the time that's the case.
+ </para>
+ <para>
+ <literal>hide-referer</literal> is an alternate spelling of
+ <literal>hide-referrer</literal> and the two can be can be freely
+ substituted with each other. (<quote>referrer</quote> is the
+ correct English spelling, however the HTTP specification has a bug - it
+ requires it to be spelled as <quote>referer</quote>.)
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>js-events</emphasis></term>
+ <term>Example usage:</term>
<listitem>
<para>
- This is a very radical measure. It removes virtually all JavaScript event bindings, which
- means that scripts can not react to user actions such as mouse movements or clicks, window
- resizing etc, anymore. Use with caution!
- </para>
- <para>
- We <emphasis>strongly discourage</emphasis> using this filter as a default since it breaks
- many legitimate scripts. It is meant for use only on extra-nasty sites (should you really
- need to go there).
+ <screen>+hide-referrer{forge}</screen> or
+ <screen>+hide-referrer{http://www.yahoo.com/}</screen>
</para>
</listitem>
</varlistentry>
+</variablelist>
+</sect3>
-<varlistentry>
- <term><emphasis>html-annoyances</emphasis></term>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="hide-user-agent">
+<title>hide-user-agent</title>
+
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Try to conceal your type of browser and client operating system</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Effect:</term>
<listitem>
<para>
- This filter will undo many common instances of HTML based abuse.
+ Replaces the value of the <quote>User-Agent:</quote> HTTP header
+ in client requests with the specified value.
</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
<para>
- The <literal>BLINK</literal> and <literal>MARQUEE</literal> tags
- are neutralized (yeah baby!), and browser windows will be created as
- resizeable (as of course they should be!), and will have location,
- scroll and menu bars -- even if specified otherwise.
+ Any user-defined string.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>content-cookies</emphasis></term>
+ <term>Notes:</term>
<listitem>
+ <warning>
+ <para>
+ This can lead to problems on web sites that depend on looking at this header in
+ order to customize their content for different browsers (which, by the
+ way, is <emphasis>NOT</emphasis> the right thing to do: good web sites
+ work browser-independently).
+ </para>
+ </warning>
<para>
- Most cookies are set in the HTTP dialog, where they can be intercepted
- by the
- <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>
- and <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>
- actions. But web sites increasingly make use of HTML meta tags and JavaScript
- to sneak cookies to the browser on the content level.
+ Using this action in multi-user setups or wherever different types of
+ browsers will access the same <application>Privoxy</application> is
+ <emphasis>not recommended</emphasis>. In single-user, single-browser
+ setups, you might use it to delete your OS version information from
+ the headers, because it is an invitation to exploit known bugs for your
+ OS. It is also occasionally useful to forge this in order to access
+ sites that won't let you in otherwise (though there may be a good
+ reason in some cases).
</para>
<para>
- This filter disables most HTML and JavaScript code that reads or sets
- cookies. It cannot detect all clever uses of these types of code, so it
- should not be relied on as an absolute fix. Use it wherever you would also
- use the cookie crunch actions.
+ More information on known user-agent strings can be found at
+ <ulink url="http://www.user-agents.org/">http://www.user-agents.org/</ulink>
+ and
+ <ulink url="http://en.wikipedia.org/wiki/User_agent">http://en.wikipedia.org/wiki/User_agent</ulink>.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen>+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</screen>
</para>
</listitem>
</varlistentry>
+</variablelist>
+</sect3>
+
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="limit-connect">
+<title>limit-connect</title>
+<variablelist>
<varlistentry>
- <term><emphasis>refresh tags</emphasis></term>
+ <term>Typical use:</term>
<listitem>
- <para>
- Disable any refresh tags if the interval is greater than nine seconds (so
- that redirections done via refresh tags are not destroyed). This is useful
- for dial-on-demand setups, or for those who find this HTML feature
- annoying.
- </para>
+ <para>Prevent abuse of <application>Privoxy</application> as a TCP proxy relay or disable SSL for untrusted sites</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>unsolicited-popups</emphasis></term>
+ <term>Effect:</term>
<listitem>
<para>
- This filter attempts to prevent only <quote>unsolicited</quote> pop-up
- windows from opening, yet still allow pop-up windows that the user
- has explicitly chosen to open. It was added in version 3.0.1,
- as an improvement over earlier such filters.
- </para>
- <para>
- Technical note: The filter works by redefining the window.open JavaScript
- function to a dummy function, <literal>PrivoxyWindowOpen()</literal>,
- during the loading and rendering phase of each HTML page access, and
- restoring the function afterward.
- </para>
- <para>
- This is recommended only for browsers that cannot perform this function
- reliably themselves. And be aware that some sites require such windows
- in order to function normally. Use with caution.
+ Specifies to which ports HTTP CONNECT requests are allowable.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>all-popups</emphasis></term>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
<listitem>
- <para>
- Attempt to prevent <emphasis>all</emphasis> pop-up windows from opening.
- Note this should be used with even more discretion than the above, since
- it is more likely to break some sites that require pop-ups for normal
- usage. Use with caution.
- </para>
+ <para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>img-reorder</emphasis></term>
+ <term>Parameter:</term>
<listitem>
<para>
- This is a helper filter that has no value if used alone. It makes the
- <literal>banners-by-size</literal> and <literal>banners-by-link</literal>
- (see below) filters more effective and should be enabled together with them.
+ A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
+ defaulting to 0 and the maximum to 65K).
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>banners-by-size</emphasis></term>
+ <term>Notes:</term>
<listitem>
<para>
- This filter removes image tags purely based on what size they are. Fortunately
- for us, many ads and banner images tend to conform to certain standardized
- sizes, which makes this filter quite effective for ad stripping purposes.
- </para>
- <para>
- Occasionally this filter will cause false positives on images that are not ads,
- but just happen to be of one of the standard banner sizes.
+ By default, i.e. if no <literal>limit-connect</literal> action applies,
+ <application>Privoxy</application> allows HTTP CONNECT requests to all
+ ports. Use <literal>limit-connect</literal> if fine-grained control
+ is desired for some or all destinations.
</para>
<para>
- Recommended only for those who require extreme ad blocking. The default
- block rules should catch 95+% of all ads <emphasis>without</emphasis> this filter enabled.
- </para>
+ The CONNECT methods exists in HTTP to allow access to secure websites
+ (<quote>https://</quote> URLs) through proxies. It works very simply:
+ the proxy connects to the server on the specified port, and then
+ short-circuits its connections to the client and to the remote server.
+ This means CONNECT-enabled proxies can be used as TCP relays very easily.
+ </para>
+ <para>
+ <application>Privoxy</application> relays HTTPS traffic without seeing
+ the decoded content. Websites can leverage this limitation to circumvent &my-app;'s
+ filters. By specifying an invalid port range you can disable HTTPS entirely.
+ </para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>banners-by-link</emphasis></term>
+ <term>Example usages:</term>
<listitem>
- <para>
- This is an experimental filter that attempts to kill any banners if
- their URLs seem to point to known or suspected click trackers. It is currently
- not of much value and is not recommended for use by default.
+ <!-- I had trouble getting the spacing to look right in my browser -->
+ <!-- I probably have the wrong font setup, bollocks. -->
+ <!-- Apparently the emphasis tag uses a proportional font no matter what -->
+ <para>
+ <screen>+limit-connect{443} # Port 443 is OK.
++limit-connect{80,443} # Ports 80 and 443 are OK.
++limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
++limit-connect{-} # All ports are OK
++limit-connect{,} # No HTTPS/SSL traffic is allowed</screen>
</para>
</listitem>
</varlistentry>
+</variablelist>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="limit-cookie-lifetime">
+<title>limit-cookie-lifetime</title>
+
+<variablelist>
<varlistentry>
- <term><emphasis>webbugs</emphasis></term>
+ <term>Typical use:</term>
<listitem>
- <para>
- Webbugs are small, invisible images (technically 1X1 GIF images), that
- are used to track users across websites, and collect information on them.
- As an HTML page is loaded by the browser, an embedded image tag causes the
- browser to contact a third-party site, disclosing the tracking information
- through the requested URL and/or cookies for that third-party domain, without
- the user ever becoming aware of the interaction with the third-party site.
- HTML-ized spam also uses a similar technique to verify email addresses.
- </para>
- <para>
- This filter removes the HTML code that loads such <quote>webbugs</quote>.
- </para>
+ <para>Limit the lifetime of HTTP cookies to a couple of minutes or hours.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>tiny-textforms</emphasis></term>
+ <term>Effect:</term>
<listitem>
<para>
- A rather special-purpose filter that can be used to enlarge textareas (those
- multi-line text boxes in web forms) and turn off hard word wrap in them.
- It was written for the sourceforge.net tracker system where such boxes are
- a nuisance, but it can be handy on other sites, too.
- </para>
- <para>
- It is not recommended to use this filter as a default.
+ Overwrites the expires field in Set-Cookie server headers if it's above the specified limit.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>jumping-windows</emphasis></term>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
<listitem>
- <para>
- Many consider windows that move, or resize themselves to be abusive. This filter
- neutralizes the related JavaScript code. Note that some sites might not display
- or behave as intended when using this filter. Use with caution.
- </para>
+ <para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>frameset-borders</emphasis></term>
+ <term>Parameter:</term>
<listitem>
<para>
- Some web designers seem to assume that everyone in the world will view their
- web sites using the same browser brand and version, screen resolution etc,
- because only that assumption could explain why they'd use static frame sizes,
- yet prevent their frames from being resized by the user, should they be too
- small to show their whole content.
- </para>
- <para>
- This filter removes the related HTML code. It should only be applied to sites
- which need it.
+ The lifetime limit in minutes, or 0.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>demoronizer</emphasis></term>
+ <term>Notes:</term>
<listitem>
<para>
- Many Microsoft products that generate HTML use non-standard extensions (read:
- violations) of the ISO 8859-1 aka Latin-1 character set. This can cause those
- HTML documents to display with errors on standard-compliant platforms.
+ This action reduces the lifetime of HTTP cookies coming from the
+ server to the specified number of minutes, starting from the time
+ the cookie passes Privoxy.
</para>
<para>
- This filter translates the MS-only characters into Latin-1 equivalents.
- It is not necessary when using MS products, and will cause corruption of
- all documents that use 8-bit character sets other than Latin-1. It's mostly
- worthwhile for Europeans on non-MS platforms, if weird garbage characters
- sometimes appear on some pages, or user agents that don't correct for this on
- the fly.
-<!--
- My version of Mozilla (ancient) shows litte square boxes for quote
- characters, and apostrophes on moronized pages. So many pages have this, I
- can read them fine now. HB 08/27/06
--->
+ Cookies with a lifetime below the limit are not modified.
+ The lifetime of session cookies is set to the specified limit.
+ </para>
+ <para>
+ The effect of this action depends on the server.
+ </para>
+ <para>
+ In case of servers which refresh their cookies with each response
+ (or at least frequently), the lifetime limit set by this action
+ is updated as well.
+ Thus, a session associated with the cookie continues to work with
+ this action enabled, as long as a new request is made before the
+ last limit set is reached.
+ </para>
+ <para>
+ However, some servers send their cookies once, with a lifetime of several
+ years (the year 2037 is a popular choice), and do not refresh them
+ until a certain event in the future, for example the user logging out.
+ In this case this action may limit the absolute lifetime of the session,
+ even if requests are made frequently.
+ </para>
+ <para>
+ If the parameter is <quote>0</quote>, this action behaves like
+ <literal><link linkend="session-cookies-only">session-cookies-only</link></literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>shockwave-flash</emphasis></term>
+ <term>Example usages:</term>
<listitem>
- <para>
- A filter for shockwave haters. As the name suggests, this filter strips code
- out of web pages that is used to embed shockwave flash objects.
- </para>
- <para>
+ <para>
+ <screen>+limit-cookie-lifetime{60}
+ </screen>
</para>
</listitem>
</varlistentry>
+</variablelist>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="prevent-compression">
+<title>prevent-compression</title>
+<variablelist>
<varlistentry>
- <term><emphasis>quicktime-kioskmode</emphasis></term>
+ <term>Typical use:</term>
<listitem>
<para>
- Change HTML code that embeds Quicktime objects so that kioskmode, which
- prevents saving, is disabled.
+ Ensure that servers send the content uncompressed, so it can be
+ passed through <literal><link linkend="filter">filter</link></literal>s.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>fun</emphasis></term>
+ <term>Effect:</term>
<listitem>
<para>
- Text replacements for subversive browsing fun. Make fun of your favorite
- Monopolist or play buzzword bingo.
+ Removes the Accept-Encoding header which can be used to ask for compressed transfer.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>crude-parental</emphasis></term>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
<listitem>
- <para>
- A demonstration-only filter that shows how <application>Privoxy</application>
- can be used to delete web content on a keyword basis.
- </para>
+ <para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>ie-exploits</emphasis></term>
+ <term>Parameter:</term>
<listitem>
<para>
- An experimental collection of text replacements to disable malicious HTML and JavaScript
- code that exploits known security holes in Internet Explorer.
- </para>
- <para>
- Presently, it only protects against Nimda and a cross-site scripting bug, and
- would need active maintenance to provide more substantial protection.
+ N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>site-specifics</emphasis></term>
+ <term>Notes:</term>
<listitem>
<para>
- Some web sites have very specific problems, the cure for which doesn't apply
- anywhere else, or could even cause damage on other sites.
+ More and more websites send their content compressed by default, which
+ is generally a good idea and saves bandwidth. But the <literal><link
+ linkend="filter">filter</link></literal> and
+ <literal><link linkend="deanimate-gifs">deanimate-gifs</link></literal>
+ actions need access to the uncompressed data.
</para>
<para>
- This is a collection of such site-specific cures which should only be applied
- to the sites they were intended for, which is what the supplied
- <filename>default.action</filename> file does. Users shouldn't need to change
- anything regarding this filter.
+ When compiled with zlib support (available since &my-app; 3.0.7), content that should be
+ filtered is decompressed on-the-fly and you don't have to worry about this action.
+ If you are using an older &my-app; version, or one that hasn't been compiled with zlib
+ support, this action can be used to convince the server to send the content uncompressed.
+ </para>
+ <para>
+ Most text-based instances compress very well, the size is seldom decreased by less than 50%,
+ for markup-heavy instances like news feeds saving more than 90% of the original size isn't
+ unusual.
+ </para>
+ <para>
+ Not using compression will therefore slow down the transfer, and you should only
+ enable this action if you really need it. As of &my-app; 3.0.7 it's disabled in all
+ predefined action settings.
+ </para>
+ <para>
+ Note that some (rare) ill-configured sites don't handle requests for uncompressed
+ documents correctly. Broken PHP applications tend to send an empty document body,
+ some IIS versions only send the beginning of the content. If you enable
+ <literal>prevent-compression</literal> per default, you might want to add
+ exceptions for those sites. See the example for how to do that.
</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><emphasis>google</emphasis></term>
+ <term>Example usage (sections):</term>
<listitem>
<para>
- A CSS based block for Google text ads. Also removes a width limitation
- and the toolbar advertisement.
- </para>
- </listitem>
- </varlistentry>
+ <screen>
+# Selectively turn off compression, and enable a filter
+#
+{ +filter{tiny-textforms} +prevent-compression }
+# Match only these sites
+ .google.
+ sourceforge.net
+ sf.net
+
+# Or instead, we could set a universal default:
+#
+{ +prevent-compression }
+ / # Match all sites
- <varlistentry>
- <term><emphasis>yahoo</emphasis></term>
- <listitem>
- <para>
- Another CSS based block, this time for Yahoo text ads. And removes
- a width limitation as well.
+# Then maybe make exceptions for broken sites:
+#
+{ -prevent-compression }
+.compusa.com/</screen>
</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><emphasis>msn</emphasis></term>
- <listitem>
- <para>
- Another CSS based block, this time for MSN text ads. And removes
- tracking URLs, as well as a width limitation.
- </para>
- </listitem>
- </varlistentry>
+</variablelist>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="overwrite-last-modified">
+<title>overwrite-last-modified</title>
+<!--
+new action
+-->
+<variablelist>
<varlistentry>
- <term><emphasis>blogspot</emphasis></term>
+ <term>Typical use:</term>
<listitem>
- <para>
- Cleans up some Blogspot blogs. Read the fine print before using this one!
- </para>
- <para>
- This filter also intentionally removes some navigation stuff and sets the
- page width to 100%. As a result, some rounded <quote>corners</quote> would
- appear to early or not at all and as fixing this would require a browser
- that understands background-size (CSS3), they are removed instead.
- </para>
+ <para>Prevent yet another way to track the user's steps between sessions.</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><emphasis>xml-to-html</emphasis></term>
+ <varlistentry>
+ <term>Effect:</term>
<listitem>
<para>
- Server-header filter to change the Content-Type from xml to html.
+ Deletes the <quote>Last-Modified:</quote> HTTP server header or modifies its value.
</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><emphasis>html-to-xml</emphasis></term>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
<listitem>
- <para>
- Server-header filter to change the Content-Type from html to xml.
- </para>
+ <para>Parameterized.</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><emphasis>no-ping</emphasis></term>
+ <varlistentry>
+ <term>Parameter:</term>
<listitem>
<para>
- Removes the non-standard <literal>ping</literal> attribute from
- anchor and area HTML tags.
+ One of the keywords: <quote>block</quote>, <quote>reset-to-request-time</quote>
+ and <quote>randomize</quote>
</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><emphasis>hide-tor-exit-notation</emphasis></term>
+ <varlistentry>
+ <term>Notes:</term>
<listitem>
<para>
- Client-header filter to remove the <command>Tor</command> exit node notation
- found in Host and Referer headers.
+ Removing the <quote>Last-Modified:</quote> header is useful for filter
+ testing, where you want to force a real reload instead of getting status
+ code <quote>304</quote>, which would cause the browser to reuse the old
+ version of the page.
</para>
<para>
- If &my-app; and <command>Tor</command> are chained and &my-app;
- is configured to use socks4a, one can use <quote>http://www.example.org.foobar.exit/</quote>
- to access the host <quote>www.example.org</quote> through the
- <command>Tor</command> exit node <quote>foobar</quote>.
+ The <quote>randomize</quote> option overwrites the value of the
+ <quote>Last-Modified:</quote> header with a randomly chosen time
+ between the original value and the current time. In theory the server
+ could send each document with a different <quote>Last-Modified:</quote>
+ header to track visits without using cookies. <quote>Randomize</quote>
+ makes it impossible and the browser can still revalidate cached documents.
</para>
<para>
- As the HTTP client isn't aware of this notation, it treats the
- whole string <quote>www.example.org.foobar.exit</quote> as host and uses it
- for the <quote>Host</quote> and <quote>Referer</quote> headers. From the
- server's point of view the resulting headers are invalid and can cause problems.
+ <quote>reset-to-request-time</quote> overwrites the value of the
+ <quote>Last-Modified:</quote> header with the current time. You could use
+ this option together with
+ <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
+ to further customize your random range.
</para>
<para>
- An invalid <quote>Referer</quote> header can trigger <quote>hot-linking</quote>
- protections, an invalid <quote>Host</quote> header will make it impossible for
- the server to find the right vhost (several domains hosted on the same IP address).
+ The preferred parameter here is <quote>randomize</quote>. It is safe
+ to use, as long as the time settings are more or less correct.
+ If the server sets the <quote>Last-Modified:</quote> header to the time
+ of the request, the random range becomes zero and the value stays the same.
+ Therefore you should later randomize it a second time with
+ <literal><link linkend="hide-if-modified-since">hided-if-modified-since</link></literal>,
+ just to be sure.
</para>
<para>
- This client-header filter removes the <quote>foo.exit</quote> part in those headers
- to prevent the mentioned problems. Note that it only modifies
- the HTTP headers, it doesn't make it impossible for the server
- to detect your <command>Tor</command> exit node based on the IP address
- the request is coming from.
+ It is also recommended to use this action together with
+ <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>.
</para>
</listitem>
</varlistentry>
-<!--
<varlistentry>
- <term><emphasis> </emphasis></term>
+ <term>Example usage:</term>
<listitem>
- <para>
- </para>
- <para>
+ <para>
+ <screen># Let the browser revalidate without being tracked across sessions
+{ +hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/</screen>
</para>
</listitem>
</varlistentry>
--->
</variablelist>
-
-</sect2>
-</sect1>
-
-<!-- ~ End section ~ -->
-
-
-
-<!-- ~~~~~ New section ~~~~~ -->
-
-<sect1 id="templates">
-<title>Privoxy's Template Files</title>
-<para>
- All <application>Privoxy</application> built-in pages, i.e. error pages such as the
- <ulink url="http://show-the-404-error.page"><quote>404 - No Such Domain</quote>
- error page</ulink>, the <ulink
- url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"><quote>BLOCKED</quote>
- page</ulink>
- and all pages of its <ulink url="http://config.privoxy.org/">web-based
- user interface</ulink>, are generated from <emphasis>templates</emphasis>.
- (<application>Privoxy</application> must be running for the above links to work as
- intended.)
-</para>
-
-<para>
- These templates are stored in a subdirectory of the <link linkend="confdir">configuration
- directory</link> called <filename>templates</filename>. On Unixish platforms,
- this is typically
- <ulink url="file:///etc/privoxy/templates/"><filename>/etc/privoxy/templates/</filename></ulink>.
-</para>
-
-<para>
- The templates are basically normal HTML files, but with place-holders (called symbols
- or exports), which <application>Privoxy</application> fills at run time. It
- is possible to edit the templates with a normal text editor, should you want
- to customize them. (<emphasis>Not recommended for the casual
- user</emphasis>). Should you create your own custom templates, you should use
- the <filename>config</filename> setting <link linkend="templdir">templdir</link>
- to specify an alternate location, so your templates do not get overwritten
- during upgrades.
- </para>
- <para>
- Note that just like in configuration files, lines starting
- with <literal>#</literal> are ignored when the templates are filled in.
-</para>
-
-<para>
- The place-holders are of the form <literal>@name@</literal>, and you will
- find a list of available symbols, which vary from template to template,
- in the comments at the start of each file. Note that these comments are not
- always accurate, and that it's probably best to look at the existing HTML
- code to find out which symbols are supported and what they are filled in with.
-</para>
-
-<para>
- A special application of this substitution mechanism is to make whole
- blocks of HTML code disappear when a specific symbol is set. We use this
- for many purposes, one of them being to include the beta warning in all
- our user interface (CGI) pages when <application>Privoxy</application>
- is in an alpha or beta development stage:
-</para>
-
-<para>
- <screen>
-<!-- @if-unstable-start -->
-
- ... beta warning HTML code goes here ...
-
-<!-- if-unstable-end@ --></screen>
-</para>
-
-<para>
- If the "unstable" symbol is set, everything in between and including
- <literal>@if-unstable-start</literal> and <literal>if-unstable-end@</literal>
- will disappear, leaving nothing but an empty comment:
-</para>
-
-<para>
- <screen><!-- --></screen>
-</para>
-
-<para>
- There's also an if-then-else construct and an <literal>#include</literal>
- mechanism, but you'll sure find out if you are inclined to edit the
- templates ;-)
-</para>
-
-<para>
- All templates refer to a style located at
- <ulink url="http://config.privoxy.org/send-stylesheet"><literal>http://config.privoxy.org/send-stylesheet</literal></ulink>.
- This is, of course, locally served by <application>Privoxy</application>
- and the source for it can be found and edited in the
- <filename>cgi-style.css</filename> template.
-</para>
-
-</sect1>
-
-<!-- ~ End section ~ -->
-
+</sect3>
<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="redirect">
+<title>redirect</title>
+<!--
+new action
+-->
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>
+ Redirect requests to other sites.
+ </para>
+ </listitem>
+ </varlistentry>
-<sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
-Requests</title>
-
-<!-- Include contacting.sgml boilerplate: -->
- &contacting;
-<!-- end boilerplate -->
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Convinces the browser that the requested document has been moved
+ to another location and the browser should get it from there.
+ </para>
+ </listitem>
+ </varlistentry>
-</sect1>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized</para>
+ </listitem>
+ </varlistentry>
-<!-- ~ End section ~ -->
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ An absolute URL or a single pcrs command.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Requests to which this action applies are answered with a
+ HTTP redirect to URLs of your choosing. The new URL is
+ either provided as parameter, or derived by applying a
+ single pcrs command to the original URL.
+ </para>
+ <para>
+ The syntax for pcrs commands is documented in the
+ <link linkend="filter-file">filter file</link> section.
+ </para>
+ <para>
+ Requests can't be blocked and redirected at the same time,
+ applying this action together with
+ <literal><link linkend="block">block</link></literal>
+ is a configuration error. Currently the request is blocked
+ and an error message logged, the behavior may change in the
+ future and result in Privoxy rejecting the action file.
+ </para>
+ <para>
+ This action can be combined with
+ <literal><link linkend="fast-redirects">fast-redirects{check-decoded-url}</link></literal>
+ to redirect to a decoded version of a rewritten URL.
+ </para>
+ <para>
+ Use this action carefully, make sure not to create redirection loops
+ and be aware that using your own redirects might make it
+ possible to fingerprint your requests.
+ </para>
+ <para>
+ In case of problems with your redirects, or simply to watch
+ them working, enable <link linkend="DEBUG">debug 128</link>.
+ </para>
+ </listitem>
+ </varlistentry>
-<!-- ~~~~~ New section ~~~~~ -->
-<sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
+ <varlistentry>
+ <term>Example usages:</term>
+ <listitem>
+ <para>
+ <screen># Replace example.com's style sheet with another one
+{ +redirect{http://localhost/css-replacements/example.com.css} }
+ example.com/stylesheet\.css
-<!-- Include copyright.sgml: -->
- ©right;
-<!-- end copyright -->
+# Create a short, easy to remember nickname for a favorite site
+# (relies on the browser to accept and forward invalid URLs to &my-app;)
+{ +redirect{https://www.privoxy.org/user-manual/actions-file.html} }
+ a
-<!-- ~~~~~ New section ~~~~~ -->
-<sect2><title>License</title>
-<!-- Include copyright.sgml: -->
- &license;
-<!-- end copyright -->
-</sect2>
-<!-- ~ End section ~ -->
+# Always use the expanded view for Undeadly.org articles
+# (Note the $ at the end of the URL pattern to make sure
+# the request for the rewritten URL isn't redirected as well)
+{+redirect{s@$@&mode=expanded@}}
+undeadly.org/cgi\?action=article&sid=\d*$
+# Redirect Google search requests to MSN
+{+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
+.google.com/search
-<!-- ~~~~~ New section ~~~~~ -->
+# Redirect MSN search requests to Yahoo
+{+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
+search.msn.com//results\.aspx\?q=
-<sect2 id="history"><title>History</title>
-<!-- Include history.sgml: -->
- &history;
-<!-- end history -->
-</sect2>
+# Redirect http://example.com/&bla=fasel&toChange=foo (and any other value but "bar")
+# to http://example.com/&bla=fasel&toChange=bar
+#
+# The URL pattern makes sure that the following request isn't redirected again.
+{+redirect{s@toChange=[^&]+@toChange=bar@}}
+example.com/.*toChange=(?!bar)
-<sect2 id="authors"><title>Authors</title>
-<!-- Include p-authors.sgml: -->
- &p-authors;
-<!-- end authors -->
-</sect2>
+# Add a shortcut to look up illumos bugs
+{+redirect{s@^http://i([0-9]+)/.*@https://www.illumos.org/issues/$1@}}
+# Redirected URL = http://i4974/
+# Redirect Destination = https://www.illumos.org/issues/4974
+i[0-9][0-9][0-9][0-9]*/
-</sect1>
+# Redirect remote requests for this manual
+# to the local version delivered by Privoxy
+{+redirect{s@^http://www@http://config@}}
+www.privoxy.org/user-manual/</screen>
+ </para>
+ </listitem>
+ </varlistentry>
-<!-- ~ End section ~ -->
+</variablelist>
+</sect3>
<!-- ~~~~~ New section ~~~~~ -->
-<sect1 id="seealso"><title>See Also</title>
-<!-- Include seealso.sgml: -->
- &seealso;
-<!-- end seealso -->
-</sect1>
+<sect3 renderas="sect4" id="server-header-filter">
+<title>server-header-filter</title>
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>
+ Rewrite or remove single server headers.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ All server headers to which this action applies are filtered on-the-fly
+ through the specified regular expression based substitutions.
+ </para>
+ </listitem>
+ </varlistentry>
-<!-- ~~~~~ New section ~~~~~ -->
-<sect1 id="appendix"><title>Appendix</title>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- boolean, parameterized, Multi-value -->
+ <listitem>
+ <para>Multi-value.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ The name of a server-header filter, as defined in one of the
+ <link linkend="filter-file">filter files</link>.
+ </para>
+ </listitem>
+ </varlistentry>
-<!-- ~~~~~ New section ~~~~~ -->
-<sect2 id="regex">
-<title>Regular Expressions</title>
-<para>
- <application>Privoxy</application> uses Perl-style <quote>regular
- expressions</quote> in its <link linkend="actions-file">actions
- files</link> and <link linkend="filter-file">filter file</link>,
- through the <ulink url="http://www.pcre.org/">PCRE</ulink> and
-<!--
- dead 08/27/06
- <ulink url="http://www.oesterhelt.org/pcrs/">PCRS</ulink> libraries.
--->
- <application>PCRS</application> libraries.
-</para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Server-header filters are applied to each header on its own, not to
+ all at once. This makes it easier to diagnose problems, but on the downside
+ you can't write filters that only change header x if header y's value is z.
+ You can do that by using tags though.
+ </para>
+ <para>
+ Server-header filters are executed after the other header actions have finished
+ and use their output as input.
+ </para>
+ <para>
+ Please refer to the <link linkend="filter-file">filter file chapter</link>
+ to learn which server-header filters are available by default, and how to
+ create your own.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- If you are reading this, you probably don't understand what <quote>regular
- expressions</quote> are, or what they can do. So this will be a very brief
- introduction only. A full explanation would require a <ulink
- url="http://www.oreilly.com/catalog/regex/">book</ulink> ;-)
-</para>
+ <varlistentry>
+ <term>Example usage (section):</term>
+ <listitem>
+ <para>
+ <screen>
+{+server-header-filter{html-to-xml}}
+example.org/xml-instance-that-is-delivered-as-html
-<para>
- Regular expressions provide a language to describe patterns that can be
- run against strings of characters (letter, numbers, etc), to see if they
- match the string or not. The patterns are themselves (sometimes complex)
- strings of literal characters, combined with wild-cards, and other special
- characters, called meta-characters. The <quote>meta-characters</quote> have
- special meanings and are used to build complex patterns to be matched against.
- Perl Compatible Regular Expressions are an especially convenient
- <quote>dialect</quote> of the regular expression language.
-</para>
+{+server-header-filter{xml-to-html}}
+example.org/instance-that-is-delivered-as-xml-but-is-not
+ </screen>
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- To make a simple analogy, we do something similar when we use wild-card
- characters when listing files with the <command>dir</command> command in DOS.
- <literal>*.*</literal> matches all filenames. The <quote>special</quote>
- character here is the asterisk which matches any and all characters. We can be
- more specific and use <literal>?</literal> to match just individual
- characters. So <quote>dir file?.text</quote> would match
- <quote>file1.txt</quote>, <quote>file2.txt</quote>, etc. We are pattern
- matching, using a similar technique to <quote>regular expressions</quote>!
-</para>
+</variablelist>
+</sect3>
-<para>
- Regular expressions do essentially the same thing, but are much, much more
- powerful. There are many more <quote>special characters</quote> and ways of
- building complex patterns however. Let's look at a few of the common ones,
- and then some examples:
-</para>
-<para><simplelist>
- <member>
- <emphasis>.</emphasis> - Matches any single character, e.g. <quote>a</quote>,
- <quote>A</quote>, <quote>4</quote>, <quote>:</quote>, or <quote>@</quote>.
- </member>
-</simplelist></para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="server-header-tagger">
+<title>server-header-tagger</title>
-<para><simplelist>
- <member>
- <emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
- times. Either/or.
- </member>
-</simplelist></para>
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>
+ Enable or disable filters based on the Content-Type header.
+ </para>
+ </listitem>
+ </varlistentry>
-<para><simplelist>
- <member>
- <emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
- times.
- </member>
-</simplelist></para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Server headers to which this action applies are filtered on-the-fly through
+ the specified regular expression based substitutions, the result is used as
+ tag.
+ </para>
+ </listitem>
+ </varlistentry>
-<para><simplelist>
- <member>
- <emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
- times.
- </member>
-</simplelist></para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- boolean, parameterized, Multi-value -->
+ <listitem>
+ <para>Multi-value.</para>
+ </listitem>
+ </varlistentry>
-<para><simplelist>
- <member>
- <emphasis>\</emphasis> - The <quote>escape</quote> character denotes that
- the following character should be taken literally. This is used where one of the
- special characters (e.g. <quote>.</quote>) needs to be taken literally and
- not as a special meta-character. Example: <quote>example\.com</quote>, makes
- sure the period is recognized only as a period (and not expanded to its
- meta-character meaning of any single character).
- </member>
-</simplelist></para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ The name of a server-header tagger, as defined in one of the
+ <link linkend="filter-file">filter files</link>.
+ </para>
+ </listitem>
+ </varlistentry>
-<para><simplelist>
- <member>
- <emphasis>[ ]</emphasis> - Characters enclosed in brackets will be matched if
- any of the enclosed characters are encountered. For instance, <quote>[0-9]</quote>
- matches any numeric digit (zero through nine). As an example, we can combine
- this with <quote>+</quote> to match any digit one of more times: <quote>[0-9]+</quote>.
- </member>
-</simplelist></para>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Server-header taggers are applied to each header on its own,
+ and as the header isn't modified, each tagger <quote>sees</quote>
+ the original.
+ </para>
+ <para>
+ Server-header taggers are executed before all other header actions
+ that modify server headers. Their tags can be used to control
+ all of the other server-header actions, the content filters
+ and the crunch actions (<link linkend="redirect">redirect</link>
+ and <link linkend="block">block</link>).
+ </para>
+ <para>
+ Obviously crunching based on tags created by server-header taggers
+ doesn't prevent the request from showing up in the server's log file.
+ </para>
-<para><simplelist>
- <member>
- <emphasis>( )</emphasis> - parentheses are used to group a sub-expression,
- or multiple sub-expressions.
- </member>
-</simplelist></para>
+ </listitem>
+ </varlistentry>
-<para><simplelist>
- <member>
- <emphasis>|</emphasis> - The <quote>bar</quote> character works like an
- <quote>or</quote> conditional statement. A match is successful if the
- sub-expression on either side of <quote>|</quote> matches. As an example:
- <quote>/(this|that) example/</quote> uses grouping and the bar character
- and would match either <quote>this example</quote> or <quote>that
- example</quote>, and nothing else.
- </member>
-</simplelist></para>
+ <varlistentry>
+ <term>Example usage (section):</term>
+ <listitem>
+ <para>
+ <screen>
+# Tag every request with the content type declared by the server
+{+server-header-tagger{content-type}}
+/
-<para>
- These are just some of the ones you are likely to use when matching URLs with
- <application>Privoxy</application>, and is a long way from a definitive
- list. This is enough to get us started with a few simple examples which may
- be more illuminating:
-</para>
+# If the response has a tag starting with 'image/' enable an external
+# filter that only applies to images.
+#
+# Note that the filter is not available by default, it's just a
+# <literal><link linkend="external-filter-syntax">silly example</link></literal>.
+{+external-filter{rotate-image} +force-text-mode}
+TAG:^image/
+ </screen>
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <emphasis><literal>/.*/banners/.*</literal></emphasis> - A simple example
- that uses the common combination of <quote>.</quote> and <quote>*</quote> to
- denote any character, zero or more times. In other words, any string at all.
- So we start with a literal forward slash, then our regular expression pattern
- (<quote>.*</quote>) another literal forward slash, the string
- <quote>banners</quote>, another forward slash, and lastly another
- <quote>.*</quote>. We are building
- a directory path here. This will match any file with the path that has a
- directory named <quote>banners</quote> in it. The <quote>.*</quote> matches
- any characters, and this could conceivably be more forward slashes, so it
- might expand into a much longer looking path. For example, this could match:
- <quote>/eye/hate/spammers/banners/annoy_me_please.gif</quote>, or just
- <quote>/banners/annoying.html</quote>, or almost an infinite number of other
- possible combinations, just so it has <quote>banners</quote> in the path
- somewhere.
-</para>
+</variablelist>
+</sect3>
-<para>
- And now something a little more complex:
-</para>
-<para>
- <emphasis><literal>/.*/adv((er)?ts?|ertis(ing|ements?))?/</literal></emphasis> -
- We have several literal forward slashes again (<quote>/</quote>), so we are
- building another expression that is a file path statement. We have another
- <quote>.*</quote>, so we are matching against any conceivable sub-path, just so
- it matches our expression. The only true literal that <emphasis>must
- match</emphasis> our pattern is <application>adv</application>, together with
- the forward slashes. What comes after the <quote>adv</quote> string is the
- interesting part.
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="session-cookies-only">
+<title>session-cookies-only</title>
-<para>
- Remember the <quote>?</quote> means the preceding expression (either a
- literal character or anything grouped with <quote>(...)</quote> in this case)
- can exist or not, since this means either zero or one match. So
- <quote>((er)?ts?|ertis(ing|ements?))</quote> is optional, as are the
- individual sub-expressions: <quote>(er)</quote>,
- <quote>(ing|ements?)</quote>, and the <quote>s</quote>. The <quote>|</quote>
- means <quote>or</quote>. We have two of those. For instance,
- <quote>(ing|ements?)</quote>, can expand to match either <quote>ing</quote>
- <emphasis>OR</emphasis> <quote>ements?</quote>. What is being done here, is an
- attempt at matching as many variations of <quote>advertisement</quote>, and
- similar, as possible. So this would expand to match just <quote>adv</quote>,
- or <quote>advert</quote>, or <quote>adverts</quote>, or
- <quote>advertising</quote>, or <quote>advertisement</quote>, or
- <quote>advertisements</quote>. You get the idea. But it would not match
- <quote>advertizements</quote> (with a <quote>z</quote>). We could fix that by
- changing our regular expression to:
- <quote>/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/</quote>, which would then match
- either spelling.
-</para>
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>
+ Allow only temporary <quote>session</quote> cookies (for the current
+ browser session <emphasis>only</emphasis>).
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- <emphasis><literal>/.*/advert[0-9]+\.(gif|jpe?g)</literal></emphasis> - Again
- another path statement with forward slashes. Anything in the square brackets
- <quote>[ ]</quote> can be matched. This is using <quote>0-9</quote> as a
- shorthand expression to mean any digit one through nine. It is the same as
- saying <quote>0123456789</quote>. So any digit matches. The <quote>+</quote>
- means one or more of the preceding expression must be included. The preceding
- expression here is what is in the square brackets -- in this case, any digit
- one through nine. Then, at the end, we have a grouping: <quote>(gif|jpe?g)</quote>.
- This includes a <quote>|</quote>, so this needs to match the expression on
- either side of that bar character also. A simple <quote>gif</quote> on one side, and the other
- side will in turn match either <quote>jpeg</quote> or <quote>jpg</quote>,
- since the <quote>?</quote> means the letter <quote>e</quote> is optional and
- can be matched once or not at all. So we are building an expression here to
- match image GIF or JPEG type image file. It must include the literal
- string <quote>advert</quote>, then one or more digits, and a <quote>.</quote>
- (which is now a literal, and not a special character, since it is escaped
- with <quote>\</quote>), and lastly either <quote>gif</quote>, or
- <quote>jpeg</quote>, or <quote>jpg</quote>. Some possible matches would
- include: <quote>//advert1.jpg</quote>,
- <quote>/nasty/ads/advert1234.gif</quote>,
- <quote>/banners/from/hell/advert99.jpg</quote>. It would not match
- <quote>advert1.gif</quote> (no leading slash), or
- <quote>/adverts232.jpg</quote> (the expression does not include an
- <quote>s</quote>), or <quote>/advert1.jsp</quote> (<quote>jsp</quote> is not
- in the expression anywhere).
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ Deletes the <quote>expires</quote> field from <quote>Set-Cookie:</quote>
+ server headers. Most browsers will not store such cookies permanently and
+ forget them in between sessions.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- We are barely scratching the surface of regular expressions here so that you
- can understand the default <application>Privoxy</application>
- configuration files, and maybe use this knowledge to customize your own
- installation. There is much, much more that can be done with regular
- expressions. Now that you know enough to get started, you can learn more on
- your own :/
-</para>
+<varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Boolean.</para>
+ </listitem>
+ </varlistentry>
-<para>
- More reading on Perl Compatible Regular expressions:
- <ulink url="http://perldoc.perl.org/perlre.html">http://perldoc.perl.org/perlre.html</ulink>
-</para>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <para>
+ N/A
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- For information on regular expression based substitutions and their applications
- in filters, please see the <link linkend="filter-file">filter file tutorial</link>
- in this manual.
-</para>
-</sect2>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ This is less strict than <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> /
+ <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal> and allows you to browse
+ websites that insist or rely on setting cookies, without compromising your privacy too badly.
+ </para>
+ <para>
+ Most browsers will not permanently store cookies that have been processed by
+ <literal>session-cookies-only</literal> and will forget about them between sessions.
+ This makes profiling cookies useless, but won't break sites which require cookies so
+ that you can log in for transactions. This is generally turned on for all
+ sites, and is the recommended setting.
+ </para>
+ <para>
+ It makes <emphasis>no sense at all</emphasis> to use <literal>session-cookies-only</literal>
+ together with <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> or
+ <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>. If you do, cookies
+ will be plainly killed.
+ </para>
+ <para>
+ Note that it is up to the browser how it handles such cookies without an <quote>expires</quote>
+ field. If you use an exotic browser, you might want to try it out to be sure.
+ </para>
+ <para>
+ This setting also has no effect on cookies that may have been stored
+ previously by the browser before starting <application>Privoxy</application>.
+ These would have to be removed manually.
+ </para>
+ <para>
+ <application>Privoxy</application> also uses
+ the <link linkend="filter-content-cookies">content-cookies filter</link>
+ to block some types of cookies. Content cookies are not effected by
+ <literal>session-cookies-only</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
-<!-- ~ End section ~ -->
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
+ <para>
+ <screen>+session-cookies-only</screen>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
<!-- ~~~~~ New section ~~~~~ -->
-<sect2>
-<title>Privoxy's Internal Pages</title>
+<sect3 renderas="sect4" id="set-image-blocker">
+<title>set-image-blocker</title>
-<para>
- Since <application>Privoxy</application> proxies each requested
- web page, it is easy for <application>Privoxy</application> to
- trap certain special URLs. In this way, we can talk directly to
- <application>Privoxy</application>, and see how it is
- configured, see how our rules are being applied, change these
- rules and other configuration options, and even turn
- <application>Privoxy's</application> filtering off, all with
- a web browser.
+<variablelist>
+ <varlistentry>
+ <term>Typical use:</term>
+ <listitem>
+ <para>Choose the replacement for blocked images</para>
+ </listitem>
+ </varlistentry>
-</para>
+ <varlistentry>
+ <term>Effect:</term>
+ <listitem>
+ <para>
+ This action alone doesn't do anything noticeable. If <emphasis>both</emphasis>
+ <literal><link linkend="block">block</link></literal> <emphasis>and</emphasis> <literal><link
+ linkend="handle-as-image">handle-as-image</link></literal> <emphasis>also</emphasis>
+ apply, i.e. if the request is to be blocked as an image,
+ <emphasis>then</emphasis> the parameter of this action decides what will be
+ sent as a replacement.
+ </para>
+ </listitem>
+ </varlistentry>
-<para>
- The URLs listed below are the special ones that allow direct access
- to <application>Privoxy</application>. Of course,
- <application>Privoxy</application> must be running to access these. If
- not, you will get a friendly error message. Internet access is not
- necessary either.
-</para>
+ <varlistentry>
+ <term>Type:</term>
+ <!-- Boolean, Parameterized, Multi-value -->
+ <listitem>
+ <para>Parameterized.</para>
+ </listitem>
+ </varlistentry>
-<para>
- <itemizedlist>
+ <varlistentry>
+ <term>Parameter:</term>
+ <listitem>
+ <itemizedlist>
+ <listitem>
+ <para>
+ <quote>pattern</quote> to send a built-in checkerboard pattern image. The image is visually
+ decent, scales very well, and makes it obvious where banners were busted.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <quote>blank</quote> to send a built-in transparent image. This makes banners disappear
+ completely, but makes it hard to detect where <application>Privoxy</application> has blocked
+ images on a given page and complicates troubleshooting if <application>Privoxy</application>
+ has blocked innocent images, like navigation icons.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <quote><replaceable class="parameter">target-url</replaceable></quote> to
+ send a redirect to <replaceable class="parameter">target-url</replaceable>. You can redirect
+ to any image anywhere, even in your local filesystem via <quote>file:///</quote> URL.
+ (But note that not all browsers support redirecting to a local file system).
+ </para>
+ <para>
+ A good application of redirects is to use special <application>Privoxy</application>-built-in
+ URLs, which send the built-in images, as <replaceable class="parameter">target-url</replaceable>.
+ This has the same visual effect as specifying <quote>blank</quote> or <quote>pattern</quote> in
+ the first place, but enables your browser to cache the replacement image, instead of requesting
+ it over and over again.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </listitem>
+ </varlistentry>
- <listitem>
- <para>
- Privoxy main page:
- </para>
- <blockquote>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
<para>
- <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
+ The URLs for the built-in images are <quote>http://config.privoxy.org/send-banner?type=<replaceable
+ class="parameter">type</replaceable></quote>, where <replaceable class="parameter">type</replaceable> is
+ either <quote>blank</quote> or <quote>pattern</quote>.
</para>
- </blockquote>
- <para>
- There is a shortcut: <ulink url="http://p.p/">http://p.p/</ulink> (But it
- doesn't provide a fall-back to a real page, in case the request is not
- sent through <application>Privoxy</application>)
- </para>
- </listitem>
-
- <listitem>
- <para>
- Show information about the current configuration, including viewing and
- editing of actions files:
- </para>
- <blockquote>
<para>
- <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
+ There is a third (advanced) type, called <quote>auto</quote>. It is <emphasis>NOT</emphasis> to be
+ used in <literal>set-image-blocker</literal>, but meant for use from <link linkend="filter-file">filters</link>.
+ Auto will select the type of image that would have applied to the referring page, had it been an image.
</para>
- </blockquote>
- </listitem>
+ </listitem>
+ </varlistentry>
- <listitem>
- <para>
- Show the source code version numbers:
- </para>
- <blockquote>
+ <varlistentry>
+ <term>Example usage:</term>
+ <listitem>
<para>
- <ulink url="http://config.privoxy.org/show-version">http://config.privoxy.org/show-version</ulink>
+ Built-in pattern:
</para>
- </blockquote>
- </listitem>
-
- <listitem>
- <para>
- Show the browser's request headers:
- </para>
- <blockquote>
<para>
- <ulink url="http://config.privoxy.org/show-request">http://config.privoxy.org/show-request</ulink>
+ <screen>+set-image-blocker{pattern}</screen>
</para>
- </blockquote>
- </listitem>
-
- <listitem>
- <para>
- Show which actions apply to a URL and why:
- </para>
- <blockquote>
<para>
- <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
+ Redirect to the BSD daemon:
</para>
- </blockquote>
- </listitem>
-
- <listitem>
- <para>
- Toggle Privoxy on or off. This feature can be turned off/on in the main
- <filename>config</filename> file. When toggled <quote>off</quote>, <quote>Privoxy</quote>
- continues to run, but only as a pass-through proxy, with no actions taking
- place:
- </para>
- <blockquote>
<para>
- <ulink url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
+ <screen>+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</screen>
</para>
- </blockquote>
- <para>
- Short cuts. Turn off, then on:
- </para>
- <blockquote>
<para>
- <ulink url="http://config.privoxy.org/toggle?set=disable">http://config.privoxy.org/toggle?set=disable</ulink>
+ Redirect to the built-in pattern for better caching:
</para>
- </blockquote>
- <blockquote>
<para>
- <ulink url="http://config.privoxy.org/toggle?set=enable">http://config.privoxy.org/toggle?set=enable</ulink>
+ <screen>+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</screen>
</para>
- </blockquote>
- </listitem>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
- </itemizedlist>
-</para>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 id="summary">
+<title>Summary</title>
<para>
- These may be bookmarked for quick reference. See next.
+ Note that many of these actions have the potential to cause a page to
+ misbehave, possibly even not to display at all. There are many ways
+ a site designer may choose to design his site, and what HTTP header
+ content, and other criteria, he may depend on. There is no way to have hard
+ and fast rules for all sites. See the <link
+ linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
+ actions.
+</para>
+</sect3>
+</sect2>
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="aliases">
+<title>Aliases</title>
+<para>
+ Custom <quote>actions</quote>, known to <application>Privoxy</application>
+ as <quote>aliases</quote>, can be defined by combining other actions.
+ These can in turn be invoked just like the built-in actions.
+ Currently, an alias name can contain any character except space, tab,
+ <quote>=</quote>,
+ <quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
+ recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
+ <quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
+ Alias names are not case sensitive, and are not required to start with a
+ <quote>+</quote> or <quote>-</quote> sign, since they are merely textually
+ expanded.
+</para>
+<para>
+ Aliases can be used throughout the actions file, but they <emphasis>must be
+ defined in a special section at the top of the file!</emphasis>
+ And there can only be one such section per actions file. Each actions file may
+ have its own alias section, and the aliases defined in it are only visible
+ within that file.
+</para>
+<para>
+ There are two main reasons to use aliases: One is to save typing for frequently
+ used combinations of actions, the other one is a gain in flexibility: If you
+ decide once how you want to handle shops by defining an alias called
+ <quote>shop</quote>, you can later change your policy on shops in
+ <emphasis>one</emphasis> place, and your changes will take effect everywhere
+ in the actions file where the <quote>shop</quote> alias is used. Calling aliases
+ by their purpose also makes your actions files more readable.
+</para>
+<para>
+ Currently, there is one big drawback to using aliases, though:
+ <application>Privoxy</application>'s built-in web-based action file
+ editor honors aliases when reading the actions files, but it expands
+ them before writing. So the effects of your aliases are of course preserved,
+ but the aliases themselves are lost when you edit sections that use aliases
+ with it.
</para>
-<sect3 id="bookmarklets">
-<title>Bookmarklets</title>
-<para>
- Below are some <quote>bookmarklets</quote> to allow you to easily access a
- <quote>mini</quote> version of some of <application>Privoxy's</application>
- special pages. They are designed for MS Internet Explorer, but should work
- equally well in Netscape, Mozilla, and other browsers which support
- JavaScript. They are designed to run directly from your bookmarks - not by
- clicking the links below (although that should work for testing).
-</para>
<para>
- To save them, right-click the link and choose <quote>Add to Favorites</quote>
- (IE) or <quote>Add Bookmark</quote> (Netscape). You will get a warning that
- the bookmark <quote>may not be safe</quote> - just click OK. Then you can run the
- Bookmarklet directly from your favorites/bookmarks. For even faster access,
- you can put them on the <quote>Links</quote> bar (IE) or the <quote>Personal
- Toolbar</quote> (Netscape), and run them with a single click.
+ Now let's define some aliases...
</para>
<para>
- <itemizedlist>
+ <screen>
+ # Useful custom aliases we can use later.
+ #
+ # Note the (required!) section header line and that this section
+ # must be at the top of the actions file!
+ #
+ {{alias}}
- <listitem>
- <para>
- <ulink
- url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=enabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Enable</ulink>
- </para>
- </listitem>
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
+ #
+ +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
+ -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
+ +block-as-image = +block{Blocked image.} +handle-as-image
+ allow-all-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
- <listitem>
- <para>
- <ulink
- url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=disabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Disable</ulink>
- </para>
- </listitem>
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
+ #
+ fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link> -<link linkend="PREVENT-COMPRESSION">prevent-compression</link>
- <listitem>
- <para>
- <ulink
- url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=toggle','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Toggle Privoxy</ulink> (Toggles between enabled and disabled)
- </para>
- </listitem>
+ shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link>
- <listitem>
- <para>
- <ulink
- url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y','ijbstatus','width=250,height=2,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy- View Status</ulink>
- </para>
- </listitem>
-<!--
- <listitem>
- <para>
- <ulink url="javascript:w=Math.floor(screen.width/2);h=Math.floor(screen.height*0.9);void(window.open('http://www.privoxy.org/actions/index.php?url='+escape(location.href),'Feedback','screenx='+w+',width='+w+',height='+h+',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Submit Actions File Feedback</ulink>
- </para>
- </listitem>
- -->
- <listitem>
- <para>
- <ulink url="javascript:void(window.open('http://config.privoxy.org/show-url-info?url='+escape(location.href),'Why').focus());">Privoxy - Why?</ulink>
- </para>
- </listitem>
- </itemizedlist>
+ # Short names for other aliases, for really lazy people ;-)
+ #
+ c0 = +crunch-all-cookies
+ c1 = -crunch-all-cookies</screen>
</para>
<para>
- Credit: The site which gave us the general idea for these bookmarklets is
- <ulink url="http://www.bookmarklets.com/">www.bookmarklets.com</ulink>. They
- have more information about bookmarklets.
+ ...and put them to use. These sections would appear in the lower part of an
+ actions file and define exceptions to the default actions (as specified further
+ up for the <quote>/</quote> pattern):
</para>
+<para>
+ <screen>
+ # These sites are either very complex or very keen on
+ # user data and require minimal interference to work:
+ #
+ {fragile}
+ .office.microsoft.com
+ .windowsupdate.microsoft.com
+ # Gmail is really mail.google.com, not gmail.com
+ mail.google.com
-</sect3>
+ # Shopping sites:
+ # Allow cookies (for setting and retrieving your customer data)
+ #
+ {shop}
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ mybank.example.com
+
+ # These shops require pop-ups:
+ #
+ {-filter{all-popups} -filter{unsolicited-popups}}
+ .dabs.com
+ .overclockers.co.uk</screen>
+</para>
+<para>
+ Aliases like <quote>shop</quote> and <quote>fragile</quote> are typically used for
+ <quote>problem</quote> sites that require more than one action to be disabled
+ in order to function properly.
+</para>
</sect2>
+<!--
+hal stop here
+-->
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="act-examples">
+<title>Actions Files Tutorial</title>
+<para>
+ The above chapters have shown <link linkend="actions-file">which actions files
+ there are and how they are organized</link>, how actions are <link
+ linkend="actions">specified</link> and <link linkend="actions-apply">applied
+ to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
+ define and use <link linkend="aliases">aliases</link>. Now, let's look at an
+ example <filename>match-all.action</filename>, <filename>default.action</filename>
+ and <filename>user.action</filename> file and see how all these pieces come together:
+</para>
+<sect3 id="match-all">
+<title>match-all.action</title>
+<para>
+ Remember <emphasis>all actions are disabled when matching starts</emphasis>,
+ so we have to explicitly enable the ones we want.
+</para>
-<!-- ~~~~~ New section ~~~~~ -->
-<sect2 id="chain">
-<title>Chain of Events</title>
<para>
- Let's take a quick look at how some of <application>Privoxy's</application>
- core features are triggered, and the ensuing sequence of events when a web
- page is requested by your browser:
+ While the <filename>match-all.action</filename> file only contains a
+ single section, it is probably the most important one. It has only one
+ pattern, <quote><literal>/</literal></quote>, but this pattern
+ <link linkend="af-patterns">matches all URLs</link>. Therefore, the set of
+ actions used in this <quote>default</quote> section <emphasis>will
+ be applied to all requests as a start</emphasis>. It can be partly or
+ wholly overridden by other actions files like <filename>default.action</filename>
+ and <filename>user.action</filename>, but it will still be largely responsible
+ for your overall browsing experience.
</para>
<para>
- <itemizedlist>
- <listitem>
- <para>
- First, your web browser requests a web page. The browser knows to send
- the request to <application>Privoxy</application>, which will in turn,
- relay the request to the remote web server after passing the following
- tests:
- </para>
- </listitem>
- <listitem>
- <para>
- <application>Privoxy</application> traps any request for its own internal CGI
- pages (e.g <ulink url="http://p.p/">http://p.p/</ulink>) and sends the CGI page back to the browser.
- </para>
- </listitem>
- <listitem>
- <para>
- Next, <application>Privoxy</application> checks to see if the URL
- matches any <link
- linkend="BLOCK"><quote>+block</quote></link> patterns. If
- so, the URL is then blocked, and the remote web server will not be contacted.
- <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>
- and
- <link linkend="HANDLE-AS-EMPTY-DOCUMENT"><quote>+handle-as-empty-document</quote></link>
- are then checked, and if there is no match, an
- HTML <quote>BLOCKED</quote> page is sent back to the browser. Otherwise, if
- it does match, an image is returned for the former, and an empty text
- document for the latter. The type of image would depend on the setting of
- <link linkend="SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></link>
- (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
- </para>
- </listitem>
- <listitem>
- <para>
- Untrusted URLs are blocked. If URLs are being added to the
- <filename>trust</filename> file, then that is done.
- </para>
- </listitem>
- <listitem>
- <para>
- If the URL pattern matches the <link
- linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link> action,
- it is then processed. Unwanted parts of the requested URL are stripped.
- </para>
- </listitem>
- <listitem>
- <para>
- Now the rest of the client browser's request headers are processed. If any
- of these match any of the relevant actions (e.g. <link
- linkend="HIDE-USER-AGENT"><quote>+hide-user-agent</quote></link>,
- etc.), headers are suppressed or forged as determined by these actions and
- their parameters.
- </para>
- </listitem>
- <listitem>
- <para>
- Now the web server starts sending its response back (i.e. typically a web
- page).
- </para>
- </listitem>
- <listitem>
- <para>
- First, the server headers are read and processed to determine, among other
- things, the MIME type (document type) and encoding. The headers are then
- filtered as determined by the
- <link linkend="CRUNCH-INCOMING-COOKIES"><quote>+crunch-incoming-cookies</quote></link>,
- <link linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>,
- and <link linkend="DOWNGRADE-HTTP-VERSION"><quote>+downgrade-http-version</quote></link>
- actions.
- </para>
- </listitem>
- <listitem>
- <para>
- If any <link linkend="FILTER"><quote>+filter</quote></link> action
- or <link
- linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
- action applies (and the document type fits the action), the rest of the page is
- read into memory (up to a configurable limit). Then the filter rules (from
- <filename>default.filter</filename> and any other filter files) are
- processed against the buffered content. Filters are applied in the order
- they are specified in one of the filter files. Animated GIFs, if present,
- are reduced to either the first or last frame, depending on the action
- setting.The entire page, which is now filtered, is then sent by
- <application>Privoxy</application> back to your browser.
- </para>
- <para>
- If neither a <link linkend="FILTER"><quote>+filter</quote></link> action
- or <link
- linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
- matches, then <application>Privoxy</application> passes the raw data through
- to the client browser as it becomes available.
- </para>
- </listitem>
- <listitem>
- <para>
- As the browser receives the now (possibly filtered) page content, it
- reads and then requests any URLs that may be embedded within the page
- source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
- frames), sounds, etc. For each of these objects, the browser issues a
- separate request (this is easily viewable in <application>Privoxy's</application>
- logs). And each such request is in turn processed just as above. Note that a
- complex web page will have many, many such embedded URLs. If these
- secondary requests are to a different server, then quite possibly a very
- differing set of actions is triggered.
- </para>
- </listitem>
+ Again, at the start of matching, all actions are disabled, so there is
+ no need to disable any actions here. (Remember: a <quote>+</quote>
+ preceding the action name enables the action, a <quote>-</quote> disables!).
+ Also note how this long line has been made more readable by splitting it into
+ multiple lines with line continuation.
+</para>
- </itemizedlist>
+<para>
+ <screen>
+{ \
+ +<link linkend="CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</link> \
+ +<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
+ +<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
+}
+/ # Match all URLs
+ </screen>
</para>
+
<para>
- NOTE: This is somewhat of a simplistic overview of what happens with each URL
- request. For the sake of brevity and simplicity, we have focused on
- <application>Privoxy's</application> core features only.
+ The default behavior is now set.
</para>
+</sect3>
-</sect2>
-
+<sect3 id="default-action">
+<title>default.action</title>
-<!-- ~~~~~ New section ~~~~~ -->
-<sect2 id="actionsanat">
-<title>Troubleshooting: Anatomy of an Action</title>
+<para>
+ If you aren't a developer, there's no need for you to edit the
+ <filename>default.action</filename> file. It is maintained by
+ the &my-app; developers and if you disagree with some of the
+ sections, you should overrule them in your <filename>user.action</filename>.
+</para>
<para>
- The way <application>Privoxy</application> applies
- <link linkend="ACTIONS">actions</link> and <link linkend="FILTER">filters</link>
- to any given URL can be complex, and not always so
- easy to understand what is happening. And sometimes we need to be able to
- <emphasis>see</emphasis> just what <application>Privoxy</application> is
- doing. Especially, if something <application>Privoxy</application> is doing
- is causing us a problem inadvertently. It can be a little daunting to look at
- the actions and filters files themselves, since they tend to be filled with
- <link linkend="regex">regular expressions</link> whose consequences are not
- always so obvious.
+ Understanding the <filename>default.action</filename> file can
+ help you with your <filename>user.action</filename>, though.
</para>
<para>
- One quick test to see if <application>Privoxy</application> is causing a problem
- or not, is to disable it temporarily. This should be the first troubleshooting
- step. See <link linkend="bookmarklets">the Bookmarklets</link> section on a quick
- and easy way to do this (be sure to flush caches afterward!). Looking at the
- logs is a good idea too. (Note that both the toggle feature and logging are
- enabled via <filename>config</filename> file settings, and may need to be
- turned <quote>on</quote>.)
+ The first section in this file is a special section for internal use
+ that prevents older &my-app; versions from reading the file:
</para>
+
<para>
- Another easy troubleshooting step to try is if you have done any
- customization of your installation, revert back to the installed
- defaults and see if that helps. There are times the developers get complaints
- about one thing or another, and the problem is more related to a customized
- configuration issue.
+ <screen>
+##########################################################################
+# Settings -- Don't change! For internal Privoxy use ONLY.
+##########################################################################
+{{settings}}
+for-privoxy-version=3.0.11</screen>
</para>
<para>
- <application>Privoxy</application> also provides the
- <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
- page that can show us very specifically how <application>actions</application>
- are being applied to any given URL. This is a big help for troubleshooting.
+ After that comes the (optional) alias section. We'll use the example
+ section from the above <link linkend="aliases">chapter on aliases</link>,
+ that also explains why and how aliases are used:
</para>
<para>
- First, enter one URL (or partial URL) at the prompt, and then
- <application>Privoxy</application> will tell us
- how the current configuration will handle it. This will not
- help with filtering effects (i.e. the <link
- linkend="FILTER"><quote>+filter</quote></link> action) from
- one of the filter files since this is handled very
- differently and not so easy to trap! It also will not tell you about any other
- URLs that may be embedded within the URL you are testing. For instance, images
- such as ads are expressed as URLs within the raw page source of HTML pages. So
- you will only get info for the actual URL that is pasted into the prompt area
- -- not any sub-URLs. If you want to know about embedded URLs like ads, you
- will have to dig those out of the HTML source. Use your browser's <quote>View
- Page Source</quote> option for this. Or right click on the ad, and grab the
- URL.
+ <screen>
+##########################################################################
+# Aliases
+##########################################################################
+{{alias}}
+
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
+ #
+ +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
+ -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
+ +block-as-image = +block{Blocked image.} +handle-as-image
+ mercy-for-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
+
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
+ #
+ fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link>
+ shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link></screen>
</para>
<para>
- Let's try an example, <ulink url="http://google.com">google.com</ulink>,
- and look at it one section at a time in a sample configuration (your real
- configuration may vary):
+ The first of our specialized sections is concerned with <quote>fragile</quote>
+ sites, i.e. sites that require minimum interference, because they are either
+ very complex or very keen on tracking you (and have mechanisms in place that
+ make them unusable for people who avoid being tracked). We will use
+ our pre-defined <literal>fragile</literal> alias instead of stating the list
+ of actions explicitly:
</para>
<para>
<screen>
- Matches for http://www.google.com:
-
- In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
+##########################################################################
+# Exceptions for sites that'll break under the default action set:
+##########################################################################
- {+change-x-forwarded-for{block}
- +deanimate-gifs {last}
- +fast-redirects {check-decoded-url}
- +filter {refresh-tags}
- +filter {img-reorder}
- +filter {banners-by-size}
- +filter {webbugs}
- +filter {jumping-windows}
- +filter {ie-exploits}
- +hide-from-header {block}
- +hide-referrer {forge}
- +session-cookies-only
- +set-image-blocker {pattern}
-/
+# "Fragile" Use a minimum set of actions for these sites (see alias above):
+#
+{ fragile }
+.office.microsoft.com # surprise, surprise!
+.windowsupdate.microsoft.com
+mail.google.com</screen>
+</para>
- { -session-cookies-only }
- .google.com
+<para>
+ Shopping sites are not as fragile, but they typically
+ require cookies to log in, and pop-up windows for shopping
+ carts or item details. Again, we'll use a pre-defined alias:
+</para>
- { -fast-redirects }
- .google.com
+<para>
+ <screen>
+# Shopping sites:
+#
+{ shop }
+.quietpc.com
+.worldpay.com # for quietpc.com
+.jungle.com
+.scan.co.uk</screen>
+</para>
-In file: user.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
-(no matches in this file)
-</screen>
+<para>
+ The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
+ action, which may have been enabled in <filename>match-all.action</filename>,
+ breaks some sites. So disable it for popular sites where we know it misbehaves:
</para>
<para>
- This is telling us how we have defined our
- <link linkend="ACTIONS"><quote>actions</quote></link>, and
- which ones match for our test case, <quote>google.com</quote>.
- Displayed is all the actions that are available to us. Remember,
- the <literal>+</literal> sign denotes <quote>on</quote>. <literal>-</literal>
- denotes <quote>off</quote>. So some are <quote>on</quote> here, but many
- are <quote>off</quote>. Each example we try may provide a slightly different
- end result, depending on our configuration directives.
+ <screen>
+{ -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
+login.yahoo.com
+edit.*.yahoo.com
+.google.com
+.altavista.com/.*(like|url|link):http
+.altavista.com/trans.*urltext=http
+.nytimes.com</screen>
</para>
+
<para>
- The first listing
- is for our <filename>default.action</filename> file. The large, multi-line
- listing, is how the actions are set to match for all URLs, i.e. our default
- settings. If you look at your <quote>actions</quote> file, this would be the
- section just below the <quote>aliases</quote> section near the top. This
- will apply to all URLs as signified by the single forward slash at the end
- of the listing -- <quote> / </quote>.
+ It is important that <application>Privoxy</application> knows which
+ URLs belong to images, so that <emphasis>if</emphasis> they are to
+ be blocked, a substitute image can be sent, rather than an HTML page.
+ Contacting the remote site to find out is not an option, since it
+ would destroy the loading time advantage of banner blocking, and it
+ would feed the advertisers information about you. We can mark any
+ URL as an image with the <literal><link
+ linkend="handle-as-image">handle-as-image</link></literal> action,
+ and marking all URLs that end in a known image file extension is a
+ good start:
</para>
<para>
- But we have defined additional actions that would be exceptions to these general
- rules, and then we list specific URLs (or patterns) that these exceptions
- would apply to. Last match wins. Just below this then are two explicit
- matches for <quote>.google.com</quote>. The first is negating our previous
- cookie setting, which was for <link
- linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>
- (i.e. not persistent). So we will allow persistent cookies for google, at
- least that is how it is in this example. The second turns
- <emphasis>off</emphasis> any <link
- linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link>
- action, allowing this to take place unmolested. Note that there is a leading
- dot here -- <quote>.google.com</quote>. This will match any hosts and
- sub-domains, in the google.com domain also, such as
- <quote>www.google.com</quote> or <quote>mail.google.com</quote>. But it would not
- match <quote>www.google.de</quote>! So, apparently, we have these two actions
- defined as exceptions to the general rules at the top somewhere in the lower
- part of our <filename>default.action</filename> file, and
- <quote>google.com</quote> is referenced somewhere in these latter sections.
+ <screen>
+##########################################################################
+# Images:
+##########################################################################
+
+# Define which file types will be treated as images, in case they get
+# blocked further down this file:
+#
+{ +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
+/.*\.(gif|jpe?g|png|bmp|ico)$</screen>
</para>
<para>
- Then, for our <filename>user.action</filename> file, we again have no hits.
- So there is nothing google-specific that we might have added to our own, local
- configuration. If there was, those actions would over-rule any actions from
- previously processed files, such as <filename>default.action</filename>.
- <filename>user.action</filename> typically has the last word. This is the
- best place to put hard and fast exceptions,
+ And then there are known banner sources. They often use scripts to
+ generate the banners, so it won't be visible from the URL that the
+ request is for an image. Hence we block them <emphasis>and</emphasis>
+ mark them as images in one go, with the help of our
+ <literal>+block-as-image</literal> alias defined above. (We could of
+ course just as well use <literal>+<link linkend="block">block</link>
+ +<link linkend="handle-as-image">handle-as-image</link></literal> here.)
+ Remember that the type of the replacement image is chosen by the
+ <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
+ action. Since all URLs have matched the default section with its
+ <literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
+ action before, it still applies and needn't be repeated:
</para>
<para>
- And finally we pull it all together in the bottom section and summarize how
- <application>Privoxy</application> is applying all its <quote>actions</quote>
- to <quote>google.com</quote>:
+ <screen>
+# Known ad generators:
+#
+{ +block-as-image }
+ar.atwola.com
+.ad.doubleclick.net
+.ad.*.doubleclick.net
+.a.yimg.com/(?:(?!/i/).)*$
+.a[0-9].yimg.com/(?:(?!/i/).)*$
+bs*.gsanet.com
+.qkimg.net</screen>
+</para>
+<para>
+ One of the most important jobs of <application>Privoxy</application>
+ is to block banners. Many of these can be <quote>blocked</quote>
+ by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
+ action, which we enabled above, and which deletes the references to banner
+ images from the pages while they are loaded, so the browser doesn't request
+ them anymore, and hence they don't need to be blocked here. But this naturally
+ doesn't catch all banners, and some people choose not to use filters, so we
+ need a comprehensive list of patterns for banner URLs here, and apply the
+ <literal><link linkend="block">block</link></literal> action to them.
+</para>
+<para>
+ First comes many generic patterns, which do most of the work, by
+ matching typical domain and path name components of banners. Then comes
+ a list of individual patterns for specific sites, which is omitted here
+ to keep the example short:
</para>
<para>
<screen>
+##########################################################################
+# Block these fine banners:
+##########################################################################
+{ <link linkend="BLOCK">+block{Banner ads.}</link> }
- Final results:
+# Generic patterns:
+#
+ad*.
+.*ads.
+banner?.
+count*.
+/.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
+/(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
- -add-header
- -block
- +change-x-forwarded-for{block}
- -client-header-filter{hide-tor-exit-notation}
- -content-type-overwrite
- -crunch-client-header
- -crunch-if-none-match
- -crunch-incoming-cookies
- -crunch-outgoing-cookies
- -crunch-server-header
- +deanimate-gifs {last}
- -downgrade-http-version
- -fast-redirects
- -filter {js-events}
- -filter {content-cookies}
- -filter {all-popups}
- -filter {banners-by-link}
- -filter {tiny-textforms}
- -filter {frameset-borders}
- -filter {demoronizer}
- -filter {shockwave-flash}
- -filter {quicktime-kioskmode}
- -filter {fun}
- -filter {crude-parental}
- -filter {site-specifics}
- -filter {js-annoyances}
- -filter {html-annoyances}
- +filter {refresh-tags}
- -filter {unsolicited-popups}
- +filter {img-reorder}
- +filter {banners-by-size}
- +filter {webbugs}
- +filter {jumping-windows}
- +filter {ie-exploits}
- -filter {google}
- -filter {yahoo}
- -filter {msn}
- -filter {blogspot}
- -filter {no-ping}
- -force-text-mode
- -handle-as-empty-document
- -handle-as-image
- -hide-accept-language
- -hide-content-disposition
- +hide-from-header {block}
- -hide-if-modified-since
- +hide-referrer {forge}
- -hide-user-agent
- -limit-connect
- -overwrite-last-modified
- -prevent-compression
- -redirect
- -server-header-filter{xml-to-html}
- -server-header-filter{html-to-xml}
- -session-cookies-only
- +set-image-blocker {pattern} </screen>
+# Site-specific patterns (abbreviated):
+#
+.hitbox.com</screen>
</para>
<para>
- Notice the only difference here to the previous listing, is to
- <quote>fast-redirects</quote> and <quote>session-cookies-only</quote>,
- which are activated specifically for this site in our configuration,
- and thus show in the <quote>Final Results</quote>.
+ It's quite remarkable how many advertisers actually call their banner
+ servers ads.<replaceable>company</replaceable>.com, or call the directory
+ in which the banners are stored literally <quote>banners</quote>. So the above
+ generic patterns are surprisingly effective.
</para>
-
<para>
- Now another example, <quote>ad.doubleclick.net</quote>:
+ But being very generic, they necessarily also catch URLs that we don't want
+ to block. The pattern <literal>.*ads.</literal> e.g. catches
+ <quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
+ but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
+ <quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
+ well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
+ section above.
+</para>
+<para>
+ Note that these are exceptions to exceptions from the default! Consider the URL
+ <quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
+ so it wouldn't get blocked. Then comes the defaults section, which matches the
+ URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
+ action once again. Then it matches <literal>.*ads.</literal>, an exception to the
+ general non-blocking policy, and suddenly
+ <literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
+ <literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
+ applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
+ with no <literal><link linkend="BLOCK">block</link></literal> action applying.
</para>
<para>
<screen>
+##########################################################################
+# Save some innocent victims of the above generic block patterns:
+##########################################################################
- { +block{Domains starts with "ad"} }
- ad*.
+# By domain:
+#
+{ -<link linkend="BLOCK">block</link> }
+adv[io]*. # (for advogato.org and advice.*)
+adsl. # (has nothing to do with ads)
+adobe. # (has nothing to do with ads either)
+ad[ud]*. # (adult.* and add.*)
+.edu # (universities don't host banners (yet!))
+.*loads. # (downloads, uploads etc)
- { +block{Domain contains "ad"} }
- .ad.
+# By path:
+#
+/.*loads/
- { +block{Doubleclick banner server} +handle-as-image }
- .[a-vx-z]*.doubleclick.net
-</screen>
+# Site-specific:
+#
+www.globalintersec.com/adv # (adv = advanced)
+www.ugu.com/sui/ugu/adv</screen>
</para>
<para>
- We'll just show the interesting part here - the explicit matches. It is
- matched three different times. Two <quote>+block{}</quote> sections,
- and a <quote>+block{} +handle-as-image</quote>,
- which is the expanded form of one of our aliases that had been defined as:
- <quote>+block-as-image</quote>. (<link
- linkend="ALIASES"><quote>Aliases</quote></link> are defined in
- the first section of the actions file and typically used to combine more
- than one action.)
+ Filtering source code can have nasty side effects,
+ so make an exception for our friends at sourceforge.net,
+ and all paths with <quote>cvs</quote> in them. Note that
+ <literal>-<link linkend="FILTER">filter</link></literal>
+ disables <emphasis>all</emphasis> filters in one fell swoop!
</para>
<para>
- Any one of these would have done the trick and blocked this as an unwanted
- image. This is unnecessarily redundant since the last case effectively
- would also cover the first. No point in taking chances with these guys
- though ;-) Note that if you want an ad or obnoxious
- URL to be invisible, it should be defined as <quote>ad.doubleclick.net</quote>
- is done here -- as both a <link
- linkend="BLOCK"><quote>+block{}</quote></link>
- <emphasis>and</emphasis> an
- <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>.
- The custom alias <quote><literal>+block-as-image</literal></quote> just
- simplifies the process and make it more readable.
+ <screen>
+# Don't filter code!
+#
+{ -<link linkend="FILTER">filter</link> }
+/(.*/)?cvs
+bugzilla.
+developer.
+wiki.
+.sourceforge.net</screen>
</para>
<para>
- One last example. Let's try <quote>http://www.example.net/adsl/HOWTO/</quote>.
- This one is giving us problems. We are getting a blank page. Hmmm ...
+ The actual <filename>default.action</filename> is of course much more
+ comprehensive, but we hope this example made clear how it works.
</para>
-<para>
- <screen>
-
- Matches for http://www.example.net/adsl/HOWTO/:
-
- In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
+</sect3>
- {-add-header
- -block
- +change-x-forwarded-for{block}
- -client-header-filter{hide-tor-exit-notation}
- -content-type-overwrite
- -crunch-client-header
- -crunch-if-none-match
- -crunch-incoming-cookies
- -crunch-outgoing-cookies
- -crunch-server-header
- +deanimate-gifs
- -downgrade-http-version
- +fast-redirects {check-decoded-url}
- -filter {js-events}
- -filter {content-cookies}
- -filter {all-popups}
- -filter {banners-by-link}
- -filter {tiny-textforms}
- -filter {frameset-borders}
- -filter {demoronizer}
- -filter {shockwave-flash}
- -filter {quicktime-kioskmode}
- -filter {fun}
- -filter {crude-parental}
- -filter {site-specifics}
- -filter {js-annoyances}
- -filter {html-annoyances}
- +filter {refresh-tags}
- -filter {unsolicited-popups}
- +filter {img-reorder}
- +filter {banners-by-size}
- +filter {webbugs}
- +filter {jumping-windows}
- +filter {ie-exploits}
- -filter {google}
- -filter {yahoo}
- -filter {msn}
- -filter {blogspot}
- -filter {no-ping}
- -force-text-mode
- -handle-as-empty-document
- -handle-as-image
- -hide-accept-language
- -hide-content-disposition
- +hide-from-header{block}
- +hide-referer{forge}
- -hide-user-agent
- -overwrite-last-modified
- +prevent-compression
- -redirect
- -server-header-filter{xml-to-html}
- -server-header-filter{html-to-xml}
- +session-cookies-only
- +set-image-blocker{blank} }
- /
+<sect3 id="user-action"><title>user.action</title>
- { +block{Path contains "ads".} +handle-as-image }
- /ads
-</screen>
+<para>
+ So far we are painting with a broad brush by setting general policies,
+ which would be a reasonable starting point for many people. Now,
+ you might want to be more specific and have customized rules that
+ are more suitable to your personal habits and preferences. These would
+ be for narrowly defined situations like your ISP or your bank, and should
+ be placed in <filename>user.action</filename>, which is parsed after all other
+ actions files and hence has the last word, over-riding any previously
+ defined actions. <filename>user.action</filename> is also a
+ <emphasis>safe</emphasis> place for your personal settings, since
+ <filename>default.action</filename> is actively maintained by the
+ <application>Privoxy</application> developers and you'll probably want
+ to install updated versions from time to time.
</para>
<para>
- Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote> in our
- configuration! But we did not want this at all! Now we see why we get the
- blank page. It is actually triggering two different actions here, and
- the effects are aggregated so that the URL is blocked, and &my-app; is told
- to treat the block as if it were an image. But this is, of course, all wrong.
- We could now add a new action below this (or better in our own
- <filename>user.action</filename> file) that explicitly
- <emphasis>un</emphasis> blocks (
- <link linkend="BLOCK"><quote>{-block}</quote></link>) paths with
- <quote>adsl</quote> in them (remember, last match in the configuration
- wins). There are various ways to handle such exceptions. Example:
+ So let's look at a few examples of things that one might typically do in
+ <filename>user.action</filename>:
</para>
+
+<!-- brief sample user.action here -->
+
<para>
<screen>
+# My user.action file. <fred@example.com></screen>
+</para>
- { -block }
- /adsl
-</screen>
+<para>
+ As <link linkend="aliases">aliases</link> are local to the actions
+ file that they are defined in, you can't use the ones from
+ <filename>default.action</filename>, unless you repeat them here:
</para>
<para>
- Now the page displays ;-)
- Remember to flush your browser's caches when making these kinds of changes to
- your configuration to insure that you get a freshly delivered page! Or, try
- using <literal>Shift+Reload</literal>.
+ <screen>
+# Aliases are local to the file they are defined in.
+# (Re-)define aliases for this file:
+#
+{{alias}}
+#
+# These aliases just save typing later, and the alias names should
+# be self explanatory.
+#
++crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ allow-all-cookies = -crunch-all-cookies -session-cookies-only
+ allow-popups = -filter{all-popups}
++block-as-image = +block{Blocked as image.} +handle-as-image
+-block-as-image = -block
+
+# These aliases define combinations of actions that are useful for
+# certain types of sites:
+#
+fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
+shop = -crunch-all-cookies allow-popups
+
+# Allow ads for selected useful free sites:
+#
+allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
+
+# Alias for specific file types that are text, but might have conflicting
+# MIME types. We want the browser to force these to be text documents.
+handle-as-text = -<link linkend="FILTER">filter</link> +-<link linkend="content-type-overwrite">content-type-overwrite{text/plain}</link> +-<link linkend="FORCE-TEXT-MODE">force-text-mode</link> -<link linkend="HIDE-CONTENT-DISPOSITION">hide-content-disposition</link></screen>
+
</para>
<para>
- But now what about a situation where we get no explicit matches like
- we did with:
+ Say you have accounts on some sites that you visit regularly, and
+ you don't want to have to log in manually each time. So you'd like
+ to allow persistent cookies for these sites. The
+ <literal>allow-all-cookies</literal> alias defined above does exactly
+ that, i.e. it disables crunching of cookies in any direction, and the
+ processing of cookies to make them only temporary.
</para>
<para>
<screen>
-
- { +block{Path starts with "ads".} +handle-as-image }
- /ads
-</screen>
+{ allow-all-cookies }
+ sourceforge.net
+ .yahoo.com
+ .msdn.microsoft.com
+ .redhat.com</screen>
</para>
<para>
- That actually was very helpful and pointed us quickly to where the problem
- was. If you don't get this kind of match, then it means one of the default
- rules in the first section of <filename>default.action</filename> is causing
- the problem. This would require some guesswork, and maybe a little trial and
- error to isolate the offending rule. One likely cause would be one of the
- <link linkend="FILTER"><quote>+filter</quote></link> actions.
- These tend to be harder to troubleshoot.
- Try adding the URL for the site to one of aliases that turn off
- <link linkend="FILTER"><quote>+filter</quote></link>:
+ Your bank is allergic to some filter, but you don't know which, so you disable them all:
</para>
<para>
<screen>
-
- { shop }
- .quietpc.com
- .worldpay.com # for quietpc.com
- .jungle.com
- .scan.co.uk
- .forbes.com
-</screen>
+{ -<link linkend="FILTER">filter</link> }
+ .your-home-banking-site.com</screen>
</para>
<para>
- <quote><literal>{ shop }</literal></quote> is an <quote>alias</quote> that expands to
- <quote><literal>{ -filter -session-cookies-only }</literal></quote>.
- Or you could do your own exception to negate filtering:
-
+ Some file types you may not want to filter for various reasons:
</para>
<para>
<screen>
+# Technical documentation is likely to contain strings that might
+# erroneously get altered by the JavaScript-oriented filters:
+#
+.tldp.org
+/(.*/)?selfhtml/
- { -filter }
- # Disable ALL filter actions for sites in this section
- .forbes.com
- developer.ibm.com
- localhost
-</screen>
+# And this stupid host sends streaming video with a wrong MIME type,
+# so that Privoxy thinks it is getting HTML and starts filtering:
+#
+stupid-server.example.com/</screen>
</para>
<para>
- This would turn off all filtering for these sites. This is best
- put in <filename>user.action</filename>, for local site
- exceptions. Note that when a simple domain pattern is used by itself (without
- the subsequent path portion), all sub-pages within that domain are included
- automatically in the scope of the action.
+ Example of a simple <link linkend="BLOCK">block</link> action. Say you've
+ seen an ad on your favourite page on example.com that you want to get rid of.
+ You have right-clicked the image, selected <quote>copy image location</quote>
+ and pasted the URL below while removing the leading http://, into a
+ <literal>{ +block{} }</literal> section. Note that <literal>{ +handle-as-image
+ }</literal> need not be specified, since all URLs ending in
+ <literal>.gif</literal> will be tagged as images by the general rules as set
+ in default.action anyway:
</para>
<para>
- Images that are inexplicably being blocked, may well be hitting the
-<link linkend="FILTER-BANNERS-BY-SIZE"><quote>+filter{banners-by-size}</quote></link>
- rule, which assumes
- that images of certain sizes are ad banners (works well
- <emphasis>most of the time</emphasis> since these tend to be standardized).
+ <screen>
+{ +<link linkend="BLOCK">block</link>{Nasty ads.} }
+ www.example.com/nasty-ads/sponsor\.gif
+ another.example.net/more/junk/here/</screen>
</para>
<para>
- <quote><literal>{ fragile }</literal></quote> is an alias that disables most
- actions that are the most likely to cause trouble. This can be used as a
- last resort for problem sites.
+ The URLs of dynamically generated banners, especially from large banner
+ farms, often don't use the well-known image file name extensions, which
+ makes it impossible for <application>Privoxy</application> to guess
+ the file type just by looking at the URL.
+ You can use the <literal>+block-as-image</literal> alias defined above for
+ these cases.
+ Note that objects which match this rule but then turn out NOT to be an
+ image are typically rendered as a <quote>broken image</quote> icon by the
+ browser. Use cautiously.
</para>
+
<para>
<screen>
-
- { fragile }
- # Handle with care: easy to break
- mail.google.
- mybank.example.com</screen>
+{ +block-as-image }
+ .doubleclick.net
+ .fastclick.net
+ /Realmedia/ads/
+ ar.atwola.com/</screen>
</para>
-
<para>
- <emphasis>Remember to flush caches!</emphasis> Note that the
- <literal>mail.google</literal> reference lacks the TLD portion (e.g.
- <quote>.com</quote>). This will effectively match any TLD with
- <literal>google</literal> in it, such as <literal>mail.google.de.</literal>,
- just as an example.
+ Now you noticed that the default configuration breaks Forbes Magazine,
+ but you were too lazy to find out which action is the culprit, and you
+ were again too lazy to give <link linkend="contact">feedback</link>, so
+ you just used the <literal>fragile</literal> alias on the site, and
+ -- <emphasis>whoa!</emphasis> -- it worked. The <literal>fragile</literal>
+ aliases disables those actions that are most likely to break a site. Also,
+ good for testing purposes to see if it is <application>Privoxy</application>
+ that is causing the problem or not. We later find other regular sites
+ that misbehave, and add those to our personalized list of troublemakers:
</para>
+
<para>
- If this still does not work, you will have to go through the remaining
- actions one by one to find which one(s) is causing the problem.
+<screen>
+{ fragile }
+ .forbes.com
+ webmail.example.com
+ .mybank.com</screen>
</para>
-</sect2>
-
-</sect1>
-
- <!--
-
- This program is free software; you can redistribute it
- and/or modify it under the terms of the GNU General
- Public License as published by the Free Software
- Foundation; either version 2 of the License, or (at
- your option) any later version.
-
- This program is distributed in the hope that it will
- be useful, but WITHOUT ANY WARRANTY; without even the
- implied warranty of MERCHANTABILITY or FITNESS FOR A
- PARTICULAR PURPOSE. See the GNU General Public
- License for more details.
-
- The GNU General Public License should be included with
- this file. If not, you can view it at
- http://www.gnu.org/copyleft/gpl.html
- or write to the Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
- USA
-
- $Log: user-manual.sgml,v $
- Revision 2.135 2011/09/04 11:10:12 fabiankeil
- Ditch trailing whitespace
-
- Revision 2.134 2011/08/18 11:45:02 fabiankeil
- Don't use unspecified MSN sites as examples for User-Agent-based descrimination
-
- Without knowing the URLs, nobody can easily verify it and it could
- be mistaken as FUD. I also assume that it's no longer an issue anyway.
-
- Revision 2.133 2011/08/18 11:42:50 fabiankeil
- Bump some more documentation copyright ranges.
-
- Revision 2.132 2011/08/17 10:40:07 fabiankeil
- Update the entities.
-
- This commit is chronological out of order.
-
- Revision 2.131 2011/04/19 13:14:10 fabiankeil
- Fix spelling errors in the documentation. Found with codespell.
-
- Revision 2.130 2010/12/01 19:28:28 fabiankeil
- Hopefully unbreak the dok target when using some kind of jade.
-
- Reported by Lee.
-
- Revision 2.129 2010/11/13 20:17:11 fabiankeil
- Merge ChangeLog updates
-
- Revision 2.128 2010/11/10 22:00:13 fabiankeil
- Update the first paragraph of the 'What's New' section.
-
- Revision 2.127 2010/11/10 21:48:54 fabiankeil
- Update the "What's New" section.
-
- Revision 2.126 2010/11/06 12:55:48 fabiankeil
- Set p-version to 3.0.17
-
- Revision 2.125 2010/09/03 17:39:37 fabiankeil
- Slightly improve the explanation of why filtering may appear slower than it is.
-
- Revision 2.124 2010/05/01 18:21:30 fabiankeil
- Explicitly mention how to match any URL.
-
- Revision 2.123 2010/02/19 16:00:38 fabiankeil
- Even more fixes.
-
- Revision 2.122 2010/02/19 15:22:47 fabiankeil
- Add missing word.
-
- Revision 2.121 2010/02/15 15:30:13 fabiankeil
- Mention the use of the no-such-domain template for DNS problems with FEATURE_IPV6_SUPPORT enabled.
-
- Revision 2.120 2010/02/13 17:38:39 fabiankeil
- Update entities for 3.0.16 stable.
-
- Revision 2.119 2010/02/13 16:37:37 fabiankeil
- Update 'What's new?' section.
-
- Revision 2.118 2010/02/11 13:59:48 fabiankeil
- Mention that the headers added by the add-header action aren't modified by other actions.
-
- Revision 2.117 2010/01/11 12:56:04 fabiankeil
- Bump copyright range as p-config.sgml's copyright line is only used in the config file.
-
- Revision 2.116 2009/11/15 14:24:12 fabiankeil
- Prepare to generate docs for 3.0.16 UNRELEASED.
-
- Revision 2.115 2009/10/10 06:19:34 fabiankeil
- Ditch a duplicated 'since'.
-
- Revision 2.114 2009/10/10 05:51:48 fabiankeil
- Update "What's new" section.
-
- Revision 2.113 2009/10/10 05:48:55 fabiankeil
- Prepare for 3.0.15 beta.
-
- Revision 2.112 2009/07/24 12:20:30 fabiankeil
- Remove duplicated period.
-
- Revision 2.111 2009/07/18 18:11:11 fabiankeil
- Don't claim that NTLM should work when there are multiple reports that it doesn't.
-
- Revision 2.110 2009/07/18 16:25:17 fabiankeil
- Fix trailing whitespace.
-
- Revision 2.109 2009/07/18 16:24:39 fabiankeil
- Bump entities for 3.0.14 beta.
-
- Revision 2.108 2009/07/18 15:49:23 fabiankeil
- Add most of the changes in 3.0.14 to the "What's New" section.
-
- Revision 2.107 2009/06/12 14:30:58 fabiankeil
- Update entities for 3.0.13 beta.
-
- Revision 2.106 2009/06/12 11:04:13 fabiankeil
- Import ChangeLog for 3.0.13 beta.
-
- Revision 2.105 2009/04/17 11:32:57 fabiankeil
- Grammar and spelling fixes.
-
- Revision 2.104 2009/04/17 11:27:49 fabiankeil
- Petr Pisar's privoxy-3.0.12-ipv6-3.diff.
-
- Revision 2.103 2009/03/21 10:49:05 fabiankeil
- Merge updated ChangeLog.
-
- Revision 2.102 2009/03/15 19:31:36 fabiankeil
- Update "What's New in this Release" section.
+<para>
+ You like the <quote>fun</quote> text replacements in <filename>default.filter</filename>,
+ but it is disabled in the distributed actions file.
+ So you'd like to turn it on in your private,
+ update-safe config, once and for all:
+</para>
- Revision 2.101 2009/02/25 19:01:56 fabiankeil
- Fix typo.
+<para>
+<screen>
+{ +<link linkend="filter-fun">filter{fun}</link> }
+ / # For ALL sites!</screen>
+</para>
- Revision 2.100 2009/02/19 17:14:11 fabiankeil
- - Copy the release cycle description from announce.txt into
- the "What's New" section.
- - Stop referring to the ChangeLog for a "complete list of changes".
- The "What's New" section already contains the complete list.
+<para>
+ Note that the above is not really a good idea: There are exceptions
+ to the filters in <filename>default.action</filename> for things that
+ really shouldn't be filtered, like code on CVS->Web interfaces. Since
+ <filename>user.action</filename> has the last word, these exceptions
+ won't be valid for the <quote>fun</quote> filtering specified here.
+</para>
- Revision 2.99 2009/02/19 02:20:22 hal9
- Make some links in seealso conditional. Man page is now privoxy only links.
+<para>
+ You might also worry about how your favourite free websites are
+ funded, and find that they rely on displaying banner advertisements
+ to survive. So you might want to specifically allow banners for those
+ sites that you feel provide value to you:
+</para>
- Revision 2.98 2009/02/16 17:10:33 fabiankeil
- Fix entry about shortened log messages. Noticed by Lee.
+<para>
+<screen>
+{ allow-ads }
+ .sourceforge.net
+ .slashdot.org
+ .osdn.net</screen>
+</para>
- Revision 2.97 2009/02/14 18:01:00 fabiankeil
- Import ChangeLog.
+<para>
+ Note that <literal>allow-ads</literal> has been aliased to
+ <literal>-<link linkend="block">block</link></literal>,
+ <literal>-<link linkend="filter-banners-by-size">filter{banners-by-size}</link></literal>, and
+ <literal>-<link linkend="filter-banners-by-link">filter{banners-by-link}</link></literal> above.
+</para>
- Revision 2.96 2009/02/14 13:14:03 fabiankeil
- Unbreak syntax.
+<para>
+ Invoke another alias here to force an over-ride of the MIME type <literal>
+ application/x-sh</literal> which typically would open a download type
+ dialog. In my case, I want to look at the shell script, and then I can save
+ it should I choose to.
+</para>
- Revision 2.95 2009/02/14 12:51:26 fabiankeil
- Mention match-all.action in the "Actions Files Tutorial" section.
+<para>
+<screen>
+{ handle-as-text }
+ /.*\.sh$</screen>
+</para>
- Revision 2.94 2009/02/14 11:50:31 fabiankeil
- Some indentation fixes.
+<para>
+ <filename>user.action</filename> is generally the best place to define
+ exceptions and additions to the default policies of
+ <filename>default.action</filename>. Some actions are safe to have their
+ default policies set here though. So let's set a default policy to have a
+ <quote>blank</quote> image as opposed to the checkerboard pattern for
+ <emphasis>ALL</emphasis> sites. <quote>/</quote> of course matches all URL
+ paths and patterns:
+</para>
- Revision 2.93 2009/02/14 10:14:42 fabiankeil
- Mention match-all.action in the action file descriptions.
+<para>
+<screen>
+{ +<link linkend="set-image-blocker">set-image-blocker{blank}</link> }
+/ # ALL sites</screen>
+</para>
- Revision 2.92 2009/02/12 16:08:26 fabiankeil
- Declare the code stable.
+</sect3>
+</sect2>
- Revision 2.91 2009/01/13 16:50:35 fabiankeil
- The standard.action file is gone.
+<!-- ~ End section ~ -->
- Revision 2.90 2008/09/26 16:53:09 fabiankeil
- Update "What's new" section.
+</sect1>
- Revision 2.89 2008/09/21 15:38:56 fabiankeil
- Fix Portage tree sync instructions in Gentoo section.
- Anonymously reported at ijbswa-developers@.
+<!-- ~ End section ~ -->
- Revision 2.88 2008/09/21 14:42:52 fabiankeil
- Add documentation for change-x-forwarded-for{},
- remove documentation for hide-forwarded-for-headers.
+<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
- Revision 2.87 2008/08/30 15:37:35 fabiankeil
- Update entities.
+<sect1 id="filter-file">
+<title>Filter Files</title>
- Revision 2.86 2008/08/16 10:12:23 fabiankeil
- Merge two sentences and move the URL to the end of the item.
+<para>
+ On-the-fly text substitutions need
+ to be defined in a <quote>filter file</quote>. Once defined, they
+ can then be invoked as an <quote>action</quote>.
+</para>
- Revision 2.85 2008/08/16 10:04:59 fabiankeil
- Some more syntax fixes. This version actually builds.
+<para>
+ &my-app; supports three different pcrs-based filter actions:
+ <literal><link linkend="filter">filter</link></literal> to
+ rewrite the content that is send to the client,
+ <literal><link linkend="client-header-filter">client-header-filter</link></literal>
+ to rewrite headers that are send by the client, and
+ <literal><link linkend="server-header-filter">server-header-filter</link></literal>
+ to rewrite headers that are send by the server.
+</para>
- Revision 2.84 2008/08/16 09:42:45 fabiankeil
- Turns out building docs works better if the syntax is valid.
+<para>
+ &my-app; also supports two tagger actions:
+ <literal><link linkend="client-header-tagger">client-header-tagger</link></literal>
+ and
+ <literal><link linkend="server-header-tagger">server-header-tagger</link></literal>.
+ Taggers and filters use the same syntax in the filter files, the difference
+ is that taggers don't modify the text they are filtering, but use a rewritten
+ version of the filtered text as tag. The tags can then be used to change the
+ applying actions through sections with <link linkend="tag-pattern">tag-patterns</link>.
+</para>
- Revision 2.83 2008/08/16 09:32:02 fabiankeil
- Mention changes since 3.0.9 beta.
+<para>
+ Finally &my-app; supports the
+ <literal><link linkend="external-filter">external-filter</link></literal> action
+ to enable <literal><link linkend="external-filter-syntax">external filters</link></literal>
+ written in proper programming languages.
+</para>
- Revision 2.82 2008/08/16 09:00:52 fabiankeil
- Fix example URL pattern (once more with feeling).
- Revision 2.81 2008/08/16 08:51:28 fabiankeil
- Update version-related entities.
+<para>
+ Multiple filter files can be defined through the <literal> <link
+ linkend="filterfile">filterfile</link></literal> config directive. The filters
+ as supplied by the developers are located in
+ <filename>default.filter</filename>. It is recommended that any locally
+ defined or modified filters go in a separately defined file such as
+ <filename>user.filter</filename>.
+ </para>
- Revision 2.80 2008/07/18 16:54:30 fabiankeil
- Remove erroneous whitespace in documentation link.
- Reported by John Chronister in #2021611.
+<para>
+ Common tasks for content filters are to eliminate common annoyances in
+ HTML and JavaScript, such as pop-up windows,
+ exit consoles, crippled windows without navigation tools, the
+ infamous <BLINK> tag etc, to suppress images with certain
+ width and height attributes (standard banner sizes or web-bugs),
+ or just to have fun.
+</para>
- Revision 2.79 2008/06/27 18:00:53 markm68k
- remove outdated startup information for mac os x
+<para>
+ Enabled content filters are applied to any content whose
+ <quote>Content Type</quote> header is recognised as a sign
+ of text-based content, with the exception of <literal>text/plain</literal>.
+ Use the <link linkend="FORCE-TEXT-MODE">force-text-mode</link> action
+ to also filter other content.
+</para>
- Revision 2.78 2008/06/21 17:03:03 fabiankeil
- Fix typo.
+<para>
+ Substitutions are made at the source level, so if you want to <quote>roll
+ your own</quote> filters, you should first be familiar with HTML syntax,
+ and, of course, regular expressions.
+</para>
- Revision 2.77 2008/06/14 13:45:22 fabiankeil
- Re-add a colon I unintentionally removed a few revisions ago.
+<para>
+ Just like the <link linkend="actions-file">actions files</link>, the
+ filter file is organized in sections, which are called <emphasis>filters</emphasis>
+ here. Each filter consists of a heading line, that starts with one of the
+ <emphasis>keywords</emphasis> <literal>FILTER:</literal>,
+ <literal>CLIENT-HEADER-FILTER:</literal> or <literal>SERVER-HEADER-FILTER:</literal>
+ followed by the filter's <emphasis>name</emphasis>, and a short (one line)
+ <emphasis>description</emphasis> of what it does. Below that line
+ come the <emphasis>jobs</emphasis>, i.e. lines that define the actual
+ text substitutions. By convention, the name of a filter
+ should describe what the filter <emphasis>eliminates</emphasis>. The
+ comment is used in the <ulink url="http://config.privoxy.org/">web-based
+ user interface</ulink>.
+</para>
- Revision 2.76 2008/06/14 13:21:28 fabiankeil
- Prepare for the upcoming 3.0.9 beta release.
+<para>
+ Once a filter called <replaceable>name</replaceable> has been defined
+ in the filter file, it can be invoked by using an action of the form
+ +<literal><link linkend="filter">filter</link>{<replaceable>name</replaceable>}</literal>
+ in any <link linkend="actions-file">actions file</link>.
+</para>
- Revision 2.75 2008/06/13 16:06:48 fabiankeil
- Update the "What's New in this Release" section with
- the ChangeLog entries changelog2doc.pl could handle.
+<para>
+ Filter definitions start with a header line that contains the filter
+ type, the filter name and the filter description.
+ A content filter header line for a filter called <quote>foo</quote> could look
+ like this:
+</para>
- Revision 2.74 2008/05/26 15:55:46 fabiankeil
- - Update "default profiles" table.
- - Add some more pcrs redirect examples and note that
- enabling debug 128 helps to get redirects working.
+<para>
+ <screen>FILTER: foo Replace all "foo" with "bar"</screen>
+</para>
- Revision 2.73 2008/05/23 14:43:18 fabiankeil
- Remove previously out-commented block that caused syntax problems.
+<para>
+ Below that line, and up to the next header line, come the jobs that
+ define what text replacements the filter executes. They are specified
+ in a syntax that imitates <ulink url="http://www.perl.org/">Perl</ulink>'s
+ <literal>s///</literal> operator. If you are familiar with Perl, you
+ will find this to be quite intuitive, and may want to look at the
+ PCRS documentation for the subtle differences to Perl behaviour.
+</para>
- Revision 2.72 2008/05/12 10:26:14 fabiankeil
- Synchronize content filter descriptions with the ones in default.filter.
+<para>
+ Most notably, the non-standard option letter <literal>U</literal> is supported,
+ which turns the default to ungreedy matching (add <literal>?</literal> to
+ quantifiers to turn them greedy again).
+</para>
- Revision 2.71 2008/04/10 17:37:16 fabiankeil
- Actually we use "modern" POSIX 1003.2 regular
- expressions in path patterns, not PCRE.
+<para>
+ The non-standard option letter <literal>D</literal> (dynamic) allows
+ to use the variables $host, $origin (the IP address the request came from),
+ $path, $url and $listen-address (the address on which Privoxy accepted the
+ client request. Example: 127.0.0.1:8118).
+ They will be replaced with the value they refer to before the filter
+ is executed.
+</para>
- Revision 2.70 2008/04/10 15:59:12 fabiankeil
- Add another section to the client-header-tagger example that shows
- how to actually change the action settings once the tag is created.
+<para>
+ Note that '$' is a bad choice for a delimiter in a dynamic filter as you
+ might end up with unintended variables if you use a variable name
+ directly after the delimiter. Variables will be resolved without
+ escaping anything, therefore you also have to be careful not to chose
+ delimiters that appear in the replacement text. For example '<' should
+ be save, while '?' will sooner or later cause conflicts with $url.
+</para>
- Revision 2.69 2008/03/29 12:14:25 fabiankeil
- Remove send-wafer and send-vanilla-wafer actions.
+<para>
+ The non-standard option letter <literal>T</literal> (trivial) prevents
+ parsing for backreferences in the substitute. Use it if you want to include
+ text like '$&' in your substitute without quoting.
+</para>
- Revision 2.68 2008/03/28 15:13:43 fabiankeil
- Remove inspect-jpegs action.
+<para>
+ If you are new to
+ <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
+ Expressions</quote></ulink>, you might want to take a look at
+ the <link linkend="regex">Appendix on regular expressions</link>, and
+ see the <ulink url="http://perldoc.perl.org/perlre.html">Perl
+ manual</ulink> for
+ <ulink url="http://perldoc.perl.org/perlop.html">the
+ <literal>s///</literal> operator's syntax</ulink> and <ulink
+ url="http://perldoc.perl.org/perlre.html">Perl-style regular
+ expressions</ulink> in general.
+ The below examples might also help to get you started.
+</para>
- Revision 2.67 2008/03/27 18:31:21 fabiankeil
- Remove kill-popups action.
- Revision 2.66 2008/03/06 16:33:47 fabiankeil
- If limit-connect isn't used, don't limit CONNECT requests to port 443.
+<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
- Revision 2.65 2008/03/04 18:30:40 fabiankeil
- Remove the treat-forbidden-connects-like-blocks action. We now
- use the "blocked" page for forbidden CONNECT requests by default.
+<sect2 id="filter-file-tut"><title>Filter File Tutorial</title>
+<para>
+ Now, let's complete our <quote>foo</quote> content filter. We have already defined
+ the heading, but the jobs are still missing. Since all it does is to replace
+ <quote>foo</quote> with <quote>bar</quote>, there is only one (trivial) job
+ needed:
+</para>
- Revision 2.64 2008/03/01 14:10:28 fabiankeil
- Use new block syntax. Still needs some polishing.
+<para>
+ <screen>s/foo/bar/</screen>
+</para>
- Revision 2.63 2008/02/22 05:50:37 markm68k
- fix merge problem
+<para>
+ But wait! Didn't the comment say that <emphasis>all</emphasis> occurrences
+ of <quote>foo</quote> should be replaced? Our current job will only take
+ care of the first <quote>foo</quote> on each page. For global substitution,
+ we'll need to add the <literal>g</literal> option:
+</para>
- Revision 2.62 2008/02/11 11:52:23 hal9
- Fix entity ... s/&/&
+<para>
+ <screen>s/foo/bar/g</screen>
+</para>
- Revision 2.61 2008/02/11 03:41:47 markm68k
- more updates for mac os x
+<para>
+ Our complete filter now looks like this:
+</para>
+<para>
+ <screen>FILTER: foo Replace all "foo" with "bar"
+s/foo/bar/g</screen>
+</para>
- Revision 2.60 2008/02/11 03:40:25 markm68k
- more updates for mac os x
+<para>
+ Let's look at some real filters for more interesting examples. Here you see
+ a filter that protects against some common annoyances that arise from JavaScript
+ abuse. Let's look at its jobs one after the other:
+</para>
- Revision 2.59 2008/02/11 00:52:34 markm68k
- reflect new changes for mac os x
- Revision 2.58 2008/02/03 21:37:40 hal9
- Apply patch from Mark: s/OSX/OS X/
+<para>
+ <screen>
+FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
- Revision 2.57 2008/02/03 19:10:14 fabiankeil
- Mention forward-socks5.
+# Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
+#
+s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg</screen>
+</para>
- Revision 2.56 2008/01/31 19:11:35 fabiankeil
- Let the +client-header-filter{hide-tor-exit-notation} example apply
- to all requests as "tainted" Referers aren't limited to exit TLDs.
+<para>
+ Following the header line and a comment, you see the job. Note that it uses
+ <literal>|</literal> as the delimiter instead of <literal>/</literal>, because
+ the pattern contains a forward slash, which would otherwise have to be escaped
+ by a backslash (<literal>\</literal>).
+</para>
- Revision 2.55 2008/01/19 21:26:37 hal9
- Add IE7 to configuration section per Gerry.
+<para>
+ Now, let's examine the pattern: it starts with the text <literal><script.*</literal>
+ enclosed in parentheses. Since the dot matches any character, and <literal>*</literal>
+ means: <quote>Match an arbitrary number of the element left of myself</quote>, this
+ matches <quote><script</quote>, followed by <emphasis>any</emphasis> text, i.e.
+ it matches the whole page, from the start of the first <script> tag.
+</para>
- Revision 2.54 2008/01/19 17:52:39 hal9
- Re-commit to fix various minor issues for new release.
+<para>
+ That's more than we want, but the pattern continues: <literal>document\.referrer</literal>
+ matches only the exact string <quote>document.referrer</quote>. The dot needed to
+ be <emphasis>escaped</emphasis>, i.e. preceded by a backslash, to take away its
+ special meaning as a joker, and make it just a regular dot. So far, the meaning is:
+ Match from the start of the first <script> tag in a the page, up to, and including,
+ the text <quote>document.referrer</quote>, if <emphasis>both</emphasis> are present
+ in the page (and appear in that order).
+</para>
- Revision 2.53 2008/01/19 15:03:05 hal9
- Doc sources tagged for 3.0.8 release.
+<para>
+ But there's still more pattern to go. The next element, again enclosed in parentheses,
+ is <literal>.*</script></literal>. You already know what <literal>.*</literal>
+ means, so the whole pattern translates to: Match from the start of the first <script>
+ tag in a page to the end of the last <script> tag, provided that the text
+ <quote>document.referrer</quote> appears somewhere in between.
+</para>
- Revision 2.52 2008/01/17 01:49:51 hal9
- Change copyright notice for docs s/2007/2008/. All these will be rebuilt soon
- enough.
+<para>
+ This is still not the whole story, since we have ignored the options and the parentheses:
+ The portions of the page matched by sub-patterns that are enclosed in parentheses, will be
+ remembered and be available through the variables <literal>$1, $2, ...</literal> in
+ the substitute. The <literal>U</literal> option switches to ungreedy matching, which means
+ that the first <literal>.*</literal> in the pattern will only <quote>eat up</quote> all
+ text in between <quote><script</quote> and the <emphasis>first</emphasis> occurrence
+ of <quote>document.referrer</quote>, and that the second <literal>.*</literal> will
+ only span the text up to the <emphasis>first</emphasis> <quote></script></quote>
+ tag. Furthermore, the <literal>s</literal> option says that the match may span
+ multiple lines in the page, and the <literal>g</literal> option again means that the
+ substitution is global.
+</para>
- Revision 2.51 2007/12/23 16:48:24 fabiankeil
- Use more precise example descriptions for the mysterious domain patterns.
+<para>
+ So, to summarize, the pattern means: Match all scripts that contain the text
+ <quote>document.referrer</quote>. Remember the parts of the script from
+ (and including) the start tag up to (and excluding) the string
+ <quote>document.referrer</quote> as <literal>$1</literal>, and the part following
+ that string, up to and including the closing tag, as <literal>$2</literal>.
+</para>
- Revision 2.50 2007/12/08 12:44:36 fabiankeil
- - Remove already commented out pre-3.0.7 changes.
- - Update the "new log defaults" paragraph.
+<para>
+ Now the pattern is deciphered, but wasn't this about substituting things? So
+ lets look at the substitute: <literal>$1"Not Your Business!"$2</literal> is
+ easy to read: The text remembered as <literal>$1</literal>, followed by
+ <literal>"Not Your Business!"</literal> (<emphasis>including</emphasis>
+ the quotation marks!), followed by the text remembered as <literal>$2</literal>.
+ This produces an exact copy of the original string, with the middle part
+ (the <quote>document.referrer</quote>) replaced by <literal>"Not Your
+ Business!"</literal>.
+</para>
- Revision 2.49 2007/12/06 18:21:55 fabiankeil
- Update hide-forwarded-for-headers description.
+<para>
+ The whole job now reads: Replace <quote>document.referrer</quote> by
+ <literal>"Not Your Business!"</literal> wherever it appears inside a
+ <script> tag. Note that this job won't break JavaScript syntax,
+ since both the original and the replacement are syntactically valid
+ string objects. The script just won't have access to the referrer
+ information anymore.
+</para>
- Revision 2.48 2007/11/24 19:07:17 fabiankeil
- - Mention request rewriting.
- - Enable the conditional-forge paragraph.
- - Minor rewordings.
+<para>
+ We'll show you two other jobs from the JavaScript taming department, but
+ this time only point out the constructs of special interest:
+</para>
- Revision 2.47 2007/11/18 14:59:47 fabiankeil
- A few "Note to Upgraders" updates.
+<para>
+ <screen>
+# The status bar is for displaying link targets, not pointless blahblah
+#
+s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig</screen>
+</para>
- Revision 2.46 2007/11/17 17:24:44 fabiankeil
- - Use new action defaults.
- - Minor fixes and rewordings.
+<para>
+ <literal>\s</literal> stands for whitespace characters (space, tab, newline,
+ carriage return, form feed), so that <literal>\s*</literal> means: <quote>zero
+ or more whitespace</quote>. The <literal>?</literal> in <literal>.*?</literal>
+ makes this matching of arbitrary text ungreedy. (Note that the <literal>U</literal>
+ option is not set). The <literal>['"]</literal> construct means: <quote>a single
+ <emphasis>or</emphasis> a double quote</quote>. Finally, <literal>\1</literal> is
+ a back-reference to the first parenthesis just like <literal>$1</literal> above,
+ with the difference that in the <emphasis>pattern</emphasis>, a backslash indicates
+ a back-reference, whereas in the <emphasis>substitute</emphasis>, it's the dollar.
+</para>
- Revision 2.45 2007/11/16 11:48:46 hal9
- Fix one typo, and add a couple of small refinements.
+<para>
+ So what does this job do? It replaces assignments of single- or double-quoted
+ strings to the <quote>window.status</quote> object with a dummy assignment
+ (using a variable name that is hopefully odd enough not to conflict with
+ real variables in scripts). Thus, it catches many cases where e.g. pointless
+ descriptions are displayed in the status bar instead of the link target when
+ you move your mouse over links.
+</para>
- Revision 2.44 2007/11/15 03:30:20 hal9
- Results of spell check.
+<para>
+ <screen>
+# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
+#
+s/(<body [^>]*)onunload(.*>)/$1never$2/iU</screen>
+</para>
- Revision 2.43 2007/11/14 18:45:39 fabiankeil
- - Mention some more contributors in the "New in this Release" list.
- - Minor rewordings.
+<para>
+ Including the
+ <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">OnUnload
+ event binding</ulink> in the HTML DOM was a <emphasis>CRIME</emphasis>.
+ When I close a browser window, I want it to close and die. Basta.
+ This job replaces the <quote>onunload</quote> attribute in
+ <quote><body></quote> tags with the dummy word <literal>never</literal>.
+ Note that the <literal>i</literal> option makes the pattern matching
+ case-insensitive. Also note that ungreedy matching alone doesn't always guarantee
+ a minimal match: In the first parenthesis, we had to use <literal>[^>]*</literal>
+ instead of <literal>.*</literal> to prevent the match from exceeding the
+ <body> tag if it doesn't contain <quote>OnUnload</quote>, but the page's
+ content does.
+</para>
- Revision 2.42 2007/11/12 03:32:40 hal9
- Updates for "What's New" and "Notes to Upgraders". Various other changes in
- preparation for new release. User Manual is almost ready.
+<para>
+ The last example is from the fun department:
+</para>
- Revision 2.41 2007/11/11 16:32:11 hal9
- This is primarily syncing What's New and Note to Upgraders sections with the many
- new features and changes (gleaned from memory but mostly from ChangeLog).
+<para>
+ <screen>
+FILTER: fun Fun text replacements
- Revision 2.40 2007/11/10 17:10:59 fabiankeil
- In the first third of the file, mention several times that
- the action editor is disabled by default in 3.0.7 beta and later.
+# Spice the daily news:
+#
+s/microsoft(?!\.com)/MicroSuck/ig</screen>
+</para>
- Revision 2.39 2007/11/05 02:34:49 hal9
- Various changes in preparation for the upcoming release. Much yet to be done.
+<para>
+ Note the <literal>(?!\.com)</literal> part (a so-called negative lookahead)
+ in the job's pattern, which means: Don't match, if the string
+ <quote>.com</quote> appears directly following <quote>microsoft</quote>
+ in the page. This prevents links to microsoft.com from being trashed, while
+ still replacing the word everywhere else.
+</para>
- Revision 2.38 2007/09/22 16:01:42 fabiankeil
- Update embedded show-url-info output.
+<para>
+ <screen>
+# Buzzword Bingo (example for extended regex syntax)
+#
+s* industry[ -]leading \
+| cutting[ -]edge \
+| customer[ -]focused \
+| market[ -]driven \
+| award[ -]winning # Comments are OK, too! \
+| high[ -]performance \
+| solutions[ -]based \
+| unmatched \
+| unparalleled \
+| unrivalled \
+*<font color="red"><b>BINGO!</b></font> \
+*igx</screen>
+</para>
- Revision 2.37 2007/08/27 16:09:55 fabiankeil
- Fix pre-chroot-nslookup description which I failed to
- copy and paste properly. Reported by Stephen Gildea.
+<para>
+ The <literal>x</literal> option in this job turns on extended syntax, and allows for
+ e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting.
+</para>
- Revision 2.36 2007/08/26 16:47:14 fabiankeil
- Add Stephen Gildea's pre-chroot-nslookup patch [#1276666],
- extensive comments moved to user manual.
+<para>
+ You get the idea?
+</para>
+</sect2>
- Revision 2.35 2007/08/26 14:59:49 fabiankeil
- Minor rewordings and fixes.
+<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
- Revision 2.34 2007/08/05 15:19:50 fabiankeil
- - Don't claim HTTP/1.1 compliance.
- - Use $ in some of the path pattern examples.
- - Use a hide-user-agent example argument without
- leading and trailing space.
- - Make it clear that the cookie actions work with
- HTTP cookies only.
- - Rephrase the inspect-jpegs text to underline
- that it's only meant to protect against a single
- exploit.
+<sect2 id="predefined-filters"><title>The Pre-defined Filters</title>
- Revision 2.33 2007/07/27 10:57:35 hal9
- Add references for user-agent strings for hide-user-agenet
+<!--
- Revision 2.32 2007/06/07 12:36:22 fabiankeil
- Apply Roland's 29_usermanual.dpatch to fix a bunch
- of syntax errors I collected over the last months.
+ Note each filter is also listed in the +filter action section above. Please
+ keep these listings in sync.
- Revision 2.31 2007/06/02 14:01:37 fabiankeil
- Start to document forward-override{}.
+-->
- Revision 2.30 2007/04/25 15:10:36 fabiankeil
- - Describe installation for FreeBSD.
- - Start to document taggers and tag patterns.
- - Don't confuse devils and daemons.
+<para>
+The distribution <filename>default.filter</filename> file contains a selection of
+pre-defined filters for your convenience:
+</para>
- Revision 2.29 2007/04/05 11:47:51 fabiankeil
- Some updates regarding header filtering,
- handling of compressed content and redirect's
- support for pcrs commands.
+<variablelist>
+ <varlistentry>
+ <term><emphasis>js-annoyances</emphasis></term>
+ <listitem>
+ <para>
+ The purpose of this filter is to get rid of particularly annoying JavaScript abuse.
+ To that end, it
+ <itemizedlist>
+ <listitem>
+ <para>
+ replaces JavaScript references to the browser's referrer information
+ with the string "Not Your Business!". This compliments the <literal><link
+ linkend="hide-referrer">hide-referrer</link></literal> action on the content level.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ removes the bindings to the DOM's
+ <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">unload
+ event</ulink> which we feel has no right to exist and is responsible for most <quote>exit consoles</quote>, i.e.
+ nasty windows that pop up when you close another one.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ removes code that causes new windows to be opened with undesired properties, such as being
+ full-screen, non-resizeable, without location, status or menu bar etc.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+ <para>
+ Use with caution. This is an aggressive filter, and can break sites that
+ rely heavily on JavaScript.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.28 2006/12/10 23:42:48 hal9
- Fix various typos reported by Adam P. Thanks.
+ <varlistentry>
+ <term><emphasis>js-events</emphasis></term>
+ <listitem>
+ <para>
+ This is a very radical measure. It removes virtually all JavaScript event bindings, which
+ means that scripts can not react to user actions such as mouse movements or clicks, window
+ resizing etc, anymore. Use with caution!
+ </para>
+ <para>
+ We <emphasis>strongly discourage</emphasis> using this filter as a default since it breaks
+ many legitimate scripts. It is meant for use only on extra-nasty sites (should you really
+ need to go there).
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.27 2006/11/14 01:57:47 hal9
- Dump all docs prior to 3.0.6 release. Various minor changes to faq and user
- manual.
+<varlistentry>
+ <term><emphasis>html-annoyances</emphasis></term>
+ <listitem>
+ <para>
+ This filter will undo many common instances of HTML based abuse.
+ </para>
+ <para>
+ The <literal>BLINK</literal> and <literal>MARQUEE</literal> tags
+ are neutralized (yeah baby!), and browser windows will be created as
+ resizeable (as of course they should be!), and will have location,
+ scroll and menu bars -- even if specified otherwise.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.26 2006/10/24 11:16:44 hal9
- Add new filters.
+ <varlistentry>
+ <term><emphasis>content-cookies</emphasis></term>
+ <listitem>
+ <para>
+ Most cookies are set in the HTTP dialog, where they can be intercepted
+ by the
+ <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>
+ and <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>
+ actions. But web sites increasingly make use of HTML meta tags and JavaScript
+ to sneak cookies to the browser on the content level.
+ </para>
+ <para>
+ This filter disables most HTML and JavaScript code that reads or sets
+ cookies. It cannot detect all clever uses of these types of code, so it
+ should not be relied on as an absolute fix. Use it wherever you would also
+ use the cookie crunch actions.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.25 2006/10/18 10:50:33 hal9
- Add note that since filters are off in Cautious, compression is ON. Turn off
- compression to make filters work on all sites.
+ <varlistentry>
+ <term><emphasis>refresh-tags</emphasis></term>
+ <listitem>
+ <para>
+ Disable any refresh tags if the interval is greater than nine seconds (so
+ that redirections done via refresh tags are not destroyed). This is useful
+ for dial-on-demand setups, or for those who find this HTML feature
+ annoying.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.24 2006/10/03 11:13:54 hal9
- More references to the new filters. Include html this time around.
+ <varlistentry>
+ <term><emphasis>unsolicited-popups</emphasis></term>
+ <listitem>
+ <para>
+ This filter attempts to prevent only <quote>unsolicited</quote> pop-up
+ windows from opening, yet still allow pop-up windows that the user
+ has explicitly chosen to open. It was added in version 3.0.1,
+ as an improvement over earlier such filters.
+ </para>
+ <para>
+ Technical note: The filter works by redefining the window.open JavaScript
+ function to a dummy function, <literal>PrivoxyWindowOpen()</literal>,
+ during the loading and rendering phase of each HTML page access, and
+ restoring the function afterward.
+ </para>
+ <para>
+ This is recommended only for browsers that cannot perform this function
+ reliably themselves. And be aware that some sites require such windows
+ in order to function normally. Use with caution.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.23 2006/10/02 22:43:53 hal9
- Contains new filter definitions from Fabian, and few other miscellaneous
- touch-ups.
+ <varlistentry>
+ <term><emphasis>all-popups</emphasis></term>
+ <listitem>
+ <para>
+ Attempt to prevent <emphasis>all</emphasis> pop-up windows from opening.
+ Note this should be used with even more discretion than the above, since
+ it is more likely to break some sites that require pop-ups for normal
+ usage. Use with caution.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.22 2006/09/22 01:27:55 hal9
- Final commit of probably various minor changes here and there. Unless
- something changes this should be ready for pending release.
+ <varlistentry>
+ <term><emphasis>img-reorder</emphasis></term>
+ <listitem>
+ <para>
+ This is a helper filter that has no value if used alone. It makes the
+ <literal>banners-by-size</literal> and <literal>banners-by-link</literal>
+ (see below) filters more effective and should be enabled together with them.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.21 2006/09/20 03:21:36 david__schmidt
- Just the tiniest tweak. Wafer thin!
+ <varlistentry>
+ <term><emphasis>banners-by-size</emphasis></term>
+ <listitem>
+ <para>
+ This filter removes image tags purely based on what size they are. Fortunately
+ for us, many ads and banner images tend to conform to certain standardized
+ sizes, which makes this filter quite effective for ad stripping purposes.
+ </para>
+ <para>
+ Occasionally this filter will cause false positives on images that are not ads,
+ but just happen to be of one of the standard banner sizes.
+ </para>
+ <para>
+ Recommended only for those who require extreme ad blocking. The default
+ block rules should catch 95+% of all ads <emphasis>without</emphasis> this filter enabled.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.20 2006/09/10 14:53:54 hal9
- Results of spell check. User manual has some updates to standard.actions file
- info.
+ <varlistentry>
+ <term><emphasis>banners-by-link</emphasis></term>
+ <listitem>
+ <para>
+ This is an experimental filter that attempts to kill any banners if
+ their URLs seem to point to known or suspected click trackers. It is currently
+ not of much value and is not recommended for use by default.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.19 2006/09/08 12:19:02 fabiankeil
- Adjust hide-if-modified-since example values
- to reflect the recent changes.
+ <varlistentry>
+ <term><emphasis>webbugs</emphasis></term>
+ <listitem>
+ <para>
+ Webbugs are small, invisible images (technically 1X1 GIF images), that
+ are used to track users across websites, and collect information on them.
+ As an HTML page is loaded by the browser, an embedded image tag causes the
+ browser to contact a third-party site, disclosing the tracking information
+ through the requested URL and/or cookies for that third-party domain, without
+ the user ever becoming aware of the interaction with the third-party site.
+ HTML-ized spam also uses a similar technique to verify email addresses.
+ </para>
+ <para>
+ This filter removes the HTML code that loads such <quote>webbugs</quote>.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.18 2006/09/08 02:38:57 hal9
- Various changes:
- -Fix a number of broken links.
- -Migrate the new Windows service command line options, and reference as
- needed.
- -Rebuild so that can be used with the new "user-manual" config capabilities.
- -Etc.
+ <varlistentry>
+ <term><emphasis>tiny-textforms</emphasis></term>
+ <listitem>
+ <para>
+ A rather special-purpose filter that can be used to enlarge textareas (those
+ multi-line text boxes in web forms) and turn off hard word wrap in them.
+ It was written for the sourceforge.net tracker system where such boxes are
+ a nuisance, but it can be handy on other sites, too.
+ </para>
+ <para>
+ It is not recommended to use this filter as a default.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.17 2006/09/05 13:25:12 david__schmidt
- Add Windows service invocation stuff (duplicated) in FAQ and in user manual under Windows startup. One probably ought to reference the other.
+ <varlistentry>
+ <term><emphasis>jumping-windows</emphasis></term>
+ <listitem>
+ <para>
+ Many consider windows that move, or resize themselves to be abusive. This filter
+ neutralizes the related JavaScript code. Note that some sites might not display
+ or behave as intended when using this filter. Use with caution.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.16 2006/09/02 12:49:37 hal9
- Various small updates for new actions, filterfiles, etc.
+ <varlistentry>
+ <term><emphasis>frameset-borders</emphasis></term>
+ <listitem>
+ <para>
+ Some web designers seem to assume that everyone in the world will view their
+ web sites using the same browser brand and version, screen resolution etc,
+ because only that assumption could explain why they'd use static frame sizes,
+ yet prevent their frames from being resized by the user, should they be too
+ small to show their whole content.
+ </para>
+ <para>
+ This filter removes the related HTML code. It should only be applied to sites
+ which need it.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.15 2006/08/30 11:15:22 hal9
- More work on the new actions, especially filter-*-headers, and What's New
- section. User Manual is close to final form for 3.0.4 release. Some tinkering
- and proof reading left to do.
+ <varlistentry>
+ <term><emphasis>demoronizer</emphasis></term>
+ <listitem>
+ <para>
+ Many Microsoft products that generate HTML use non-standard extensions (read:
+ violations) of the ISO 8859-1 aka Latin-1 character set. This can cause those
+ HTML documents to display with errors on standard-compliant platforms.
+ </para>
+ <para>
+ This filter translates the MS-only characters into Latin-1 equivalents.
+ It is not necessary when using MS products, and will cause corruption of
+ all documents that use 8-bit character sets other than Latin-1. It's mostly
+ worthwhile for Europeans on non-MS platforms, if weird garbage characters
+ sometimes appear on some pages, or user agents that don't correct for this on
+ the fly.
+<!--
+ My version of Mozilla (ancient) shows litte square boxes for quote
+ characters, and apostrophes on moronized pages. So many pages have this, I
+ can read them fine now. HB 08/27/06
+-->
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.14 2006/08/29 10:59:36 hal9
- Add a "Whats New in this release" Section. Further work on multiple filter
- files, and assorted other minor changes.
+ <varlistentry>
+ <term><emphasis>shockwave-flash</emphasis></term>
+ <listitem>
+ <para>
+ A filter for shockwave haters. As the name suggests, this filter strips code
+ out of web pages that is used to embed shockwave flash objects.
+ </para>
+ <para>
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.13 2006/08/22 11:04:59 hal9
- Silence warnings and errors. This should build now. New filters were only
- stubbed in. More to be done.
+ <varlistentry>
+ <term><emphasis>quicktime-kioskmode</emphasis></term>
+ <listitem>
+ <para>
+ Change HTML code that embeds Quicktime objects so that kioskmode, which
+ prevents saving, is disabled.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.12 2006/08/14 08:40:39 fabiankeil
- Documented new actions that were part of
- the "minor Privoxy improvements".
+ <varlistentry>
+ <term><emphasis>fun</emphasis></term>
+ <listitem>
+ <para>
+ Text replacements for subversive browsing fun. Make fun of your favorite
+ Monopolist or play buzzword bingo.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 2.11 2006/07/18 14:48:51 david__schmidt
- Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
- with what was really the latest development (the v_3_0_branch branch)
+ <varlistentry>
+ <term><emphasis>crude-parental</emphasis></term>
+ <listitem>
+ <para>
+ A demonstration-only filter that shows how <application>Privoxy</application>
+ can be used to delete web content on a keyword basis.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.43 2005/05/23 09:59:10 hal9
- Fix typo 'loose'
+ <varlistentry>
+ <term><emphasis>ie-exploits</emphasis></term>
+ <listitem>
+ <para>
+ An experimental collection of text replacements to disable malicious HTML and JavaScript
+ code that exploits known security holes in Internet Explorer.
+ </para>
+ <para>
+ Presently, it only protects against Nimda and a cross-site scripting bug, and
+ would need active maintenance to provide more substantial protection.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.42 2004/12/04 14:39:57 hal9
- Fix two minor typos per bug SF report.
+ <varlistentry>
+ <term><emphasis>site-specifics</emphasis></term>
+ <listitem>
+ <para>
+ Some web sites have very specific problems, the cure for which doesn't apply
+ anywhere else, or could even cause damage on other sites.
+ </para>
+ <para>
+ This is a collection of such site-specific cures which should only be applied
+ to the sites they were intended for, which is what the supplied
+ <filename>default.action</filename> file does. Users shouldn't need to change
+ anything regarding this filter.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.41 2004/03/23 12:58:42 oes
- Fixed an inaccuracy
+ <varlistentry>
+ <term><emphasis>google</emphasis></term>
+ <listitem>
+ <para>
+ A CSS based block for Google text ads. Also removes a width limitation
+ and the toolbar advertisement.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.40 2004/02/27 12:48:49 hal9
- Add comment re: redirecting to local file system for set-image-blocker may
- is dependent on browser.
+ <varlistentry>
+ <term><emphasis>yahoo</emphasis></term>
+ <listitem>
+ <para>
+ Another CSS based block, this time for Yahoo text ads. And removes
+ a width limitation as well.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.39 2004/01/30 22:31:40 oes
- Added a hint re bookmarklets to Quickstart section
+ <varlistentry>
+ <term><emphasis>msn</emphasis></term>
+ <listitem>
+ <para>
+ Another CSS based block, this time for MSN text ads. And removes
+ tracking URLs, as well as a width limitation.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.38 2004/01/30 16:47:51 oes
- Some minor clarifications
+ <varlistentry>
+ <term><emphasis>blogspot</emphasis></term>
+ <listitem>
+ <para>
+ Cleans up some Blogspot blogs. Read the fine print before using this one!
+ </para>
+ <para>
+ This filter also intentionally removes some navigation stuff and sets the
+ page width to 100%. As a result, some rounded <quote>corners</quote> would
+ appear to early or not at all and as fixing this would require a browser
+ that understands background-size (CSS3), they are removed instead.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.37 2004/01/29 22:36:11 hal9
- Updates for no longer filtering text/plain, and demoronizer default settings,
- and copyright notice dates.
+ <varlistentry>
+ <term><emphasis>xml-to-html</emphasis></term>
+ <listitem>
+ <para>
+ Server-header filter to change the Content-Type from xml to html.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.36 2003/12/10 02:26:26 hal9
- Changed the demoronizer filter description.
+ <varlistentry>
+ <term><emphasis>html-to-xml</emphasis></term>
+ <listitem>
+ <para>
+ Server-header filter to change the Content-Type from html to xml.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.35 2003/11/06 13:36:37 oes
- Updated link to nightly CVS tarball
+ <varlistentry>
+ <term><emphasis>no-ping</emphasis></term>
+ <listitem>
+ <para>
+ Removes the non-standard <literal>ping</literal> attribute from
+ anchor and area HTML tags.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.34 2003/06/26 23:50:16 hal9
- Add a small bit on filtering and problems re: source code being corrupted.
+ <varlistentry>
+ <term><emphasis>hide-tor-exit-notation</emphasis></term>
+ <listitem>
+ <para>
+ Client-header filter to remove the <command>Tor</command> exit node notation
+ found in Host and Referer headers.
+ </para>
+ <para>
+ If &my-app; and <command>Tor</command> are chained and &my-app;
+ is configured to use socks4a, one can use <quote>http://www.example.org.foobar.exit/</quote>
+ to access the host <quote>www.example.org</quote> through the
+ <command>Tor</command> exit node <quote>foobar</quote>.
+ </para>
+ <para>
+ As the HTTP client isn't aware of this notation, it treats the
+ whole string <quote>www.example.org.foobar.exit</quote> as host and uses it
+ for the <quote>Host</quote> and <quote>Referer</quote> headers. From the
+ server's point of view the resulting headers are invalid and can cause problems.
+ </para>
+ <para>
+ An invalid <quote>Referer</quote> header can trigger <quote>hot-linking</quote>
+ protections, an invalid <quote>Host</quote> header will make it impossible for
+ the server to find the right vhost (several domains hosted on the same IP address).
+ </para>
+ <para>
+ This client-header filter removes the <quote>foo.exit</quote> part in those headers
+ to prevent the mentioned problems. Note that it only modifies
+ the HTTP headers, it doesn't make it impossible for the server
+ to detect your <command>Tor</command> exit node based on the IP address
+ the request is coming from.
+ </para>
+ </listitem>
+ </varlistentry>
- Revision 1.123.2.33 2003/05/08 18:17:33 roro
- Use apt-get instead of dpkg to install Debian package, which is more
- solid, uses the correct and most recent Debian version automatically.
+<!--
+ <varlistentry>
+ <term><emphasis> </emphasis></term>
+ <listitem>
+ <para>
+ </para>
+ <para>
+ </para>
+ </listitem>
+ </varlistentry>
+-->
+</variablelist>
- Revision 1.123.2.32 2003/04/11 03:13:57 hal9
- Add small note about only one filterfile (as opposed to multiple actions
- files).
+</sect2>
- Revision 1.123.2.31 2003/03/26 02:03:43 oes
- Updated hard-coded copyright dates
+<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
+<sect2 id="external-filter-syntax"><title>External filter syntax</title>
+<para>
+ External filters are scripts or programs that can modify the content in
+ case common <literal><link linkend="filter">filters</link></literal>
+ aren't powerful enough.
+</para>
+<para>
+ External filters can be written in any language the platform &my-app; runs
+ on supports.
+</para>
+<para>
+ They are controlled with the
+ <literal><link linkend="external-filter">external-filter</link></literal> action
+ and have to be defined in the <literal><link linkend="filterfile">filterfile</link></literal>
+ first.
+</para>
+<para>
+ The header looks like any other filter, but instead of pcrs jobs, external
+ filters contain a single job which can be a program or a shell script (which
+ may call other scripts or programs).
+</para>
+<para>
+ External filters read the content from STDIN and write the rewritten
+ content to STDOUT.
+ The environment variables PRIVOXY_URL, PRIVOXY_PATH, PRIVOXY_HOST,
+ PRIVOXY_ORIGIN, PRIVOXY_LISTEN_ADDRESS can be used to get some details
+ about the client request.
+</para>
+<para>
+ &my-app; will temporary store the content to filter in the
+ <literal><link linkend="temporary-directory">temporary-directory</link></literal>.
+</para>
+<para>
+ <screen>
+EXTERNAL-FILTER: cat Pointless example filter that doesn't actually modify the content
+/bin/cat
- Revision 1.123.2.30 2003/03/24 12:58:56 hal9
- Add new section on Predefined Filters.
+# Incorrect reimplementation of the filter above in POSIX shell.
+#
+# Note that it's a single job that spans multiple lines, the line
+# breaks are not passed to the shell, thus the semicolons are required.
+#
+# If the script isn't trivial, it is recommended to put it into an external file.
+#
+# In general, writing external filters entirely in POSIX shell is not
+# considered a good idea.
+EXTERNAL-FILTER: cat2 Pointless example filter that despite its name may actually modify the content
+while read line; \
+do \
+ echo "$line"; \
+done
+
+EXTERNAL-FILTER: rotate-image Rotate an image by 180 degree. Test filter with limited value.
+/usr/local/bin/convert - -rotate 180 -
+
+EXTERNAL-FILTER: citation-needed Adds a "[citation needed]" tag to an image. The coordinates may need adjustment.
+/usr/local/bin/convert - -pointsize 16 -fill white -annotate +17+418 "[citation needed]" -
+</screen>
+</para>
- Revision 1.123.2.29 2003/03/20 02:45:29 hal9
- More problems with \-\-chroot causing markup problems :(
+<warning>
+ <para>
+ Currently external filters are executed with &my-app;'s privileges!
+ Only use external filters you understand and trust.
+ </para>
+</warning>
+<para>
+ External filters are experimental and the syntax may change in the future.
+</para>
+</sect2>
- Revision 1.123.2.28 2003/03/19 00:35:24 hal9
- Manual edit of revision log because 'chroot' (even inside a comment) was
- causing Docbook to hang here (due to double hyphen and the processor thinking
- it was a comment).
+</sect1>
- Revision 1.123.2.27 2003/03/18 19:37:14 oes
- s/Advanced|Radical/Adventuresome/g to avoid complaints re fun filter
+<!-- ~ End section ~ -->
- Revision 1.123.2.26 2003/03/17 16:50:53 oes
- Added documentation for new chroot option
- Revision 1.123.2.25 2003/03/15 18:36:55 oes
- Adapted to the new filters
- Revision 1.123.2.24 2002/11/17 06:41:06 hal9
- Move default profiles table from FAQ to U-M, and other minor related changes.
- Add faq on cookies.
+<!-- ~~~~~ New section ~~~~~ -->
- Revision 1.123.2.23 2002/10/21 02:32:01 hal9
- Updates to the user.action examples section. A few new ones.
+<sect1 id="templates">
+<title>Privoxy's Template Files</title>
+<para>
+ All <application>Privoxy</application> built-in pages, i.e. error pages such as the
+ <ulink url="http://show-the-404-error.page"><quote>404 - No Such Domain</quote>
+ error page</ulink>, the <ulink
+ url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"><quote>BLOCKED</quote>
+ page</ulink>
+ and all pages of its <ulink url="http://config.privoxy.org/">web-based
+ user interface</ulink>, are generated from <emphasis>templates</emphasis>.
+ (<application>Privoxy</application> must be running for the above links to work as
+ intended.)
+</para>
- Revision 1.123.2.22 2002/10/12 00:51:53 hal9
- Add demoronizer to filter section.
+<para>
+ These templates are stored in a subdirectory of the <link linkend="confdir">configuration
+ directory</link> called <filename>templates</filename>. On Unixish platforms,
+ this is typically
+ <ulink url="file:///etc/privoxy/templates/"><filename>/etc/privoxy/templates/</filename></ulink>.
+</para>
- Revision 1.123.2.21 2002/10/10 04:09:35 hal9
- s/Advanced/Radical/ and added very brief note.
+<para>
+ The templates are basically normal HTML files, but with place-holders (called symbols
+ or exports), which <application>Privoxy</application> fills at run time. It
+ is possible to edit the templates with a normal text editor, should you want
+ to customize them. (<emphasis>Not recommended for the casual
+ user</emphasis>). Should you create your own custom templates, you should use
+ the <filename>config</filename> setting <link linkend="templdir">templdir</link>
+ to specify an alternate location, so your templates do not get overwritten
+ during upgrades.
+ </para>
+ <para>
+ Note that just like in configuration files, lines starting
+ with <literal>#</literal> are ignored when the templates are filled in.
+</para>
- Revision 1.123.2.20 2002/10/10 03:49:21 hal9
- Add notes to session-cookies-only and Quickstart about pre-existing
- cookies. Also, note content-cookies work differently.
+<para>
+ The place-holders are of the form <literal>@name@</literal>, and you will
+ find a list of available symbols, which vary from template to template,
+ in the comments at the start of each file. Note that these comments are not
+ always accurate, and that it's probably best to look at the existing HTML
+ code to find out which symbols are supported and what they are filled in with.
+</para>
- Revision 1.123.2.19 2002/09/26 01:25:36 hal9
- More explanation on Privoxy patterns, more on content-cookies and SSL.
+<para>
+ A special application of this substitution mechanism is to make whole
+ blocks of HTML code disappear when a specific symbol is set. We use this
+ for many purposes, one of them being to include the beta warning in all
+ our user interface (CGI) pages when <application>Privoxy</application>
+ is in an alpha or beta development stage:
+</para>
- Revision 1.123.2.18 2002/08/22 23:47:58 hal9
- Add 'Documentation' to Privoxy Menu shot in Configuration section to match
- CGIs.
+<para>
+ <screen>
+<!-- @if-unstable-start -->
- Revision 1.123.2.17 2002/08/18 01:13:05 hal9
- Spell checked (only one typo this time!).
+ ... beta warning HTML code goes here ...
- Revision 1.123.2.16 2002/08/09 19:20:54 david__schmidt
- Update to Mac OS X startup script name
+<!-- if-unstable-end@ --></screen>
+</para>
- Revision 1.123.2.15 2002/08/07 17:32:11 oes
- Converted some internal links from ulink to link for PDF creation; no content changed
+<para>
+ If the "unstable" symbol is set, everything in between and including
+ <literal>@if-unstable-start</literal> and <literal>if-unstable-end@</literal>
+ will disappear, leaving nothing but an empty comment:
+</para>
- Revision 1.123.2.14 2002/08/06 09:16:13 oes
- Nits re: actions file download
+<para>
+ <screen><!-- --></screen>
+</para>
- Revision 1.123.2.13 2002/08/02 18:23:19 g_sauthoff
- Just 2 small corrections to the Gentoo sections
+<para>
+ There's also an if-then-else construct and an <literal>#include</literal>
+ mechanism, but you'll sure find out if you are inclined to edit the
+ templates ;-)
+</para>
- Revision 1.123.2.12 2002/08/02 18:17:21 g_sauthoff
- Added 2 Gentoo sections
+<para>
+ All templates refer to a style located at
+ <ulink url="http://config.privoxy.org/send-stylesheet"><literal>http://config.privoxy.org/send-stylesheet</literal></ulink>.
+ This is, of course, locally served by <application>Privoxy</application>
+ and the source for it can be found and edited in the
+ <filename>cgi-style.css</filename> template.
+</para>
- Revision 1.123.2.11 2002/07/26 15:20:31 oes
- - Added version info to title
- - Added info on new filters
- - Revised parts of the filter file tutorial
- - Added info on where to get updated actions files
+</sect1>
- Revision 1.123.2.10 2002/07/25 21:42:29 hal9
- Add brief notes on not proxying non-HTTP protocols.
+<!-- ~ End section ~ -->
- Revision 1.123.2.9 2002/07/11 03:40:28 david__schmidt
- Updated Mac OS X sections due to installation location change
- Revision 1.123.2.8 2002/06/09 16:36:32 hal9
- Clarifications on filtering and MIME. Hardcode 'latest release' in index.html.
+<!-- ~~~~~ New section ~~~~~ -->
- Revision 1.123.2.7 2002/06/09 00:29:34 hal9
- Touch ups on filtering, in actions section and Anatomy.
+<sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
+Requests</title>
- Revision 1.123.2.6 2002/06/06 23:11:03 hal9
- Fix broken link. Linkchecked all docs.
+<!-- Include contacting.sgml boilerplate: -->
+ &contacting;
+<!-- end boilerplate -->
- Revision 1.123.2.5 2002/05/29 02:01:02 hal9
- This is break out of the entire config section from u-m, so it can
- eventually be used to generate the comments, etc in the main config file
- so that these are in sync with each other.
+</sect1>
- Revision 1.123.2.4 2002/05/27 03:28:45 hal9
- Ooops missed something from David.
+<!-- ~ End section ~ -->
- Revision 1.123.2.3 2002/05/27 03:23:17 hal9
- Fix FIXMEs for OS2 and Mac OS X startup. Fix Redhat typos (should be Red Hat).
- That's a wrap, I think.
- Revision 1.123.2.2 2002/05/26 19:02:09 hal9
- Move Amiga stuff around to take of FIXME in start up section.
+<!-- ~~~~~ New section ~~~~~ -->
+<sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
- Revision 1.123.2.1 2002/05/26 17:04:25 hal9
- -Spellcheck, very minor edits, and sync across branches
+<!-- Include copyright.sgml: -->
+ ©right;
+<!-- end copyright -->
- Revision 1.123 2002/05/24 23:19:23 hal9
- Include new image (Proxy setup). More fun with guibutton.
- Minor corrections/clarifications here and there.
+<para>
+ <application>Privoxy</application> is free software; you can
+ redistribute it and/or modify it under the terms of the
+ <citetitle>GNU General Public License</citetitle>, version 2,
+ as published by the Free Software Foundation and included in
+ the next section.
+</para>
- Revision 1.122 2002/05/24 13:24:08 oes
- Added Bookmarklet for one-click pre-filled access to show-url-info
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="license"><title>License</title>
+<para>
+ <screen><![ RCDATA [ &GPLv2; ]]></screen>
+</para>
- Revision 1.121 2002/05/23 23:20:17 oes
- - Changed more (all?) references to actions to the
- <literal><link> style.
- - Small fixes in the actions chapter
- - Small clarifications in the quickstart to ad blocking
- - Removed <emphasis> from <title>s since the new doc CSS
- renders them red (bad in TOC).
+</sect2>
+<!-- ~ End section ~ -->
- Revision 1.120 2002/05/23 19:16:43 roro
- Correct Debian specials (installation and startup).
- Revision 1.119 2002/05/22 17:17:05 oes
- Added Security hint
+<!-- ~~~~~ New section ~~~~~ -->
- Revision 1.118 2002/05/21 04:54:55 hal9
- -New Section: Quickstart to Ad Blocking
- -Reformat Actions Anatomy to match new CGI layout
+<sect2 id="history"><title>History</title>
+<!-- Include history.sgml: -->
+ &history;
+<!-- end history -->
+</sect2>
- Revision 1.117 2002/05/17 13:56:16 oes
- - Reworked & extended Templates chapter
- - Small changes to Regex appendix
- - #included authors.sgml into (C) and hist chapter
+<sect2 id="authors"><title>Authors</title>
+<!-- Include p-authors.sgml: -->
+ &p-authors;
+<!-- end authors -->
+</sect2>
- Revision 1.116 2002/05/17 03:23:46 hal9
- Fixing merge conflict in Quickstart section.
+</sect1>
- Revision 1.115 2002/05/16 16:25:00 oes
- Extended the Filter File chapter & minor fixes
+<!-- ~ End section ~ -->
- Revision 1.114 2002/05/16 09:42:50 oes
- More ulink->link, added some hints to Quickstart section
- Revision 1.113 2002/05/15 21:07:25 oes
- Extended and further commented the example actions files
+<!-- ~~~~~ New section ~~~~~ -->
+<sect1 id="seealso"><title>See Also</title>
+<!-- Include seealso.sgml: -->
+ &seealso;
+<!-- end seealso -->
+</sect1>
- Revision 1.112 2002/05/15 03:57:14 hal9
- Spell check. A few minor edits here and there for better syntax and
- clarification.
- Revision 1.111 2002/05/14 23:01:36 oes
- Fixing the fixes
- Revision 1.110 2002/05/14 19:10:45 oes
- Restored alphabetical order of actions
+<!-- ~~~~~ New section ~~~~~ -->
+<sect1 id="appendix"><title>Appendix</title>
- Revision 1.109 2002/05/14 17:23:11 oes
- Renamed the prevent-*-cookies actions, extended aliases section and moved it before the example AFs
- Revision 1.108 2002/05/14 15:29:12 oes
- Completed proofreading the actions chapter
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="regex">
+<title>Regular Expressions</title>
+<para>
+ <application>Privoxy</application> uses Perl-style <quote>regular
+ expressions</quote> in its <link linkend="actions-file">actions
+ files</link> and <link linkend="filter-file">filter file</link>,
+ through the <ulink url="http://www.pcre.org/">PCRE</ulink> and
+<!--
+ dead 08/27/06
+ <ulink url="http://www.oesterhelt.org/pcrs/">PCRS</ulink> libraries.
+-->
+ <application>PCRS</application> libraries.
+</para>
- Revision 1.107 2002/05/12 03:20:41 hal9
- Small clarifications for 127.0.0.1 vs localhost for listen-address since this
- apparently an important distinction for some OS's.
+<para>
+ If you are reading this, you probably don't understand what <quote>regular
+ expressions</quote> are, or what they can do. So this will be a very brief
+ introduction only. A full explanation would require a <ulink
+ url="http://www.oreilly.com/catalog/regex/">book</ulink> ;-)
+</para>
- Revision 1.106 2002/05/10 01:48:20 hal9
- This is mostly proposed copyright/licensing additions and changes. Docs
- are still GPL, but licensing and copyright are more visible. Also, copyright
- changed in doc header comments (eliminate references to JB except FAQ).
+<para>
+ Regular expressions provide a language to describe patterns that can be
+ run against strings of characters (letter, numbers, etc), to see if they
+ match the string or not. The patterns are themselves (sometimes complex)
+ strings of literal characters, combined with wild-cards, and other special
+ characters, called meta-characters. The <quote>meta-characters</quote> have
+ special meanings and are used to build complex patterns to be matched against.
+ Perl Compatible Regular Expressions are an especially convenient
+ <quote>dialect</quote> of the regular expression language.
+</para>
- Revision 1.105 2002/05/05 20:26:02 hal9
- Sorting out license vs copyright in these docs.
+<para>
+ To make a simple analogy, we do something similar when we use wild-card
+ characters when listing files with the <command>dir</command> command in DOS.
+ <literal>*.*</literal> matches all filenames. The <quote>special</quote>
+ character here is the asterisk which matches any and all characters. We can be
+ more specific and use <literal>?</literal> to match just individual
+ characters. So <quote>dir file?.text</quote> would match
+ <quote>file1.txt</quote>, <quote>file2.txt</quote>, etc. We are pattern
+ matching, using a similar technique to <quote>regular expressions</quote>!
+</para>
- Revision 1.104 2002/05/04 08:44:45 swa
- bumped version
+<para>
+ Regular expressions do essentially the same thing, but are much, much more
+ powerful. There are many more <quote>special characters</quote> and ways of
+ building complex patterns however. Let's look at a few of the common ones,
+ and then some examples:
+</para>
- Revision 1.103 2002/05/04 00:40:53 hal9
- -Remove the TOC first page kludge. It's fixed proper now in ldp.dsl.in.
- -Some minor additions to Quickstart.
+<para><simplelist>
+ <member>
+ <emphasis>.</emphasis> - Matches any single character, e.g. <quote>a</quote>,
+ <quote>A</quote>, <quote>4</quote>, <quote>:</quote>, or <quote>@</quote>.
+ </member>
+</simplelist></para>
- Revision 1.102 2002/05/03 17:46:00 oes
- Further proofread & reactivated short build instructions
+<para><simplelist>
+ <member>
+ <emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
+ times. Either/or.
+ </member>
+</simplelist></para>
- Revision 1.101 2002/05/03 03:58:30 hal9
- Move the user-manual config directive to top of section. Add note about
- Privoxy needing read permissions for configs, and write for logs.
+<para><simplelist>
+ <member>
+ <emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
+ times.
+ </member>
+</simplelist></para>
- Revision 1.100 2002/04/29 03:05:55 hal9
- Add clarification on differences of new actions files.
+<para><simplelist>
+ <member>
+ <emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
+ times.
+ </member>
+</simplelist></para>
- Revision 1.99 2002/04/28 16:59:05 swa
- more structure in starting section
+<para><simplelist>
+ <member>
+ <emphasis>\</emphasis> - The <quote>escape</quote> character denotes that
+ the following character should be taken literally. This is used where one of the
+ special characters (e.g. <quote>.</quote>) needs to be taken literally and
+ not as a special meta-character. Example: <quote>example\.com</quote>, makes
+ sure the period is recognized only as a period (and not expanded to its
+ meta-character meaning of any single character).
+ </member>
+</simplelist></para>
- Revision 1.98 2002/04/28 05:43:59 hal9
- This is the break up of configuration.html into multiple files. This
- will probably break links elsewhere :(
+<para><simplelist>
+ <member>
+ <emphasis>[ ]</emphasis> - Characters enclosed in brackets will be matched if
+ any of the enclosed characters are encountered. For instance, <quote>[0-9]</quote>
+ matches any numeric digit (zero through nine). As an example, we can combine
+ this with <quote>+</quote> to match any digit one of more times: <quote>[0-9]+</quote>.
+ </member>
+</simplelist></para>
- Revision 1.97 2002/04/27 21:04:42 hal9
- -Rewrite of Actions File example.
- -Add section for user-manual directive in config.
+<para><simplelist>
+ <member>
+ <emphasis>( )</emphasis> - parentheses are used to group a sub-expression,
+ or multiple sub-expressions.
+ </member>
+</simplelist></para>
- Revision 1.96 2002/04/27 05:32:00 hal9
- -Add short section to Filter Files to tie in with +filter action.
- -Start rewrite of examples in Actions Examples (not finished).
+<para><simplelist>
+ <member>
+ <emphasis>|</emphasis> - The <quote>bar</quote> character works like an
+ <quote>or</quote> conditional statement. A match is successful if the
+ sub-expression on either side of <quote>|</quote> matches. As an example:
+ <quote>/(this|that) example/</quote> uses grouping and the bar character
+ and would match either <quote>this example</quote> or <quote>that
+ example</quote>, and nothing else.
+ </member>
+</simplelist></para>
- Revision 1.95 2002/04/26 17:23:29 swa
- bookmarks cleaned, changed structure of user manual, screen and programlisting cleanups, and numerous other changes that I forgot
+<para>
+ These are just some of the ones you are likely to use when matching URLs with
+ <application>Privoxy</application>, and is a long way from a definitive
+ list. This is enough to get us started with a few simple examples which may
+ be more illuminating:
+</para>
- Revision 1.94 2002/04/26 05:24:36 hal9
- -Add most of Andreas suggestions to Chain of Events section.
- -A few other minor corrections and touch up.
+<para>
+ <emphasis><literal>/.*/banners/.*</literal></emphasis> - A simple example
+ that uses the common combination of <quote>.</quote> and <quote>*</quote> to
+ denote any character, zero or more times. In other words, any string at all.
+ So we start with a literal forward slash, then our regular expression pattern
+ (<quote>.*</quote>) another literal forward slash, the string
+ <quote>banners</quote>, another forward slash, and lastly another
+ <quote>.*</quote>. We are building
+ a directory path here. This will match any file with the path that has a
+ directory named <quote>banners</quote> in it. The <quote>.*</quote> matches
+ any characters, and this could conceivably be more forward slashes, so it
+ might expand into a much longer looking path. For example, this could match:
+ <quote>/eye/hate/spammers/banners/annoy_me_please.gif</quote>, or just
+ <quote>/banners/annoying.html</quote>, or almost an infinite number of other
+ possible combinations, just so it has <quote>banners</quote> in the path
+ somewhere.
+</para>
- Revision 1.92 2002/04/25 18:55:13 hal9
- More catchups on new actions files, and new actions names.
- Other assorted cleanups, and minor modifications.
+<para>
+ And now something a little more complex:
+</para>
- Revision 1.91 2002/04/24 02:39:31 hal9
- Add 'Chain of Events' section.
+<para>
+ <emphasis><literal>/.*/adv((er)?ts?|ertis(ing|ements?))?/</literal></emphasis> -
+ We have several literal forward slashes again (<quote>/</quote>), so we are
+ building another expression that is a file path statement. We have another
+ <quote>.*</quote>, so we are matching against any conceivable sub-path, just so
+ it matches our expression. The only true literal that <emphasis>must
+ match</emphasis> our pattern is <application>adv</application>, together with
+ the forward slashes. What comes after the <quote>adv</quote> string is the
+ interesting part.
+</para>
- Revision 1.90 2002/04/23 21:41:25 hal9
- Linuxconf is deprecated on RH, substitute chkconfig.
+<para>
+ Remember the <quote>?</quote> means the preceding expression (either a
+ literal character or anything grouped with <quote>(...)</quote> in this case)
+ can exist or not, since this means either zero or one match. So
+ <quote>((er)?ts?|ertis(ing|ements?))</quote> is optional, as are the
+ individual sub-expressions: <quote>(er)</quote>,
+ <quote>(ing|ements?)</quote>, and the <quote>s</quote>. The <quote>|</quote>
+ means <quote>or</quote>. We have two of those. For instance,
+ <quote>(ing|ements?)</quote>, can expand to match either <quote>ing</quote>
+ <emphasis>OR</emphasis> <quote>ements?</quote>. What is being done here, is an
+ attempt at matching as many variations of <quote>advertisement</quote>, and
+ similar, as possible. So this would expand to match just <quote>adv</quote>,
+ or <quote>advert</quote>, or <quote>adverts</quote>, or
+ <quote>advertising</quote>, or <quote>advertisement</quote>, or
+ <quote>advertisements</quote>. You get the idea. But it would not match
+ <quote>advertizements</quote> (with a <quote>z</quote>). We could fix that by
+ changing our regular expression to:
+ <quote>/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/</quote>, which would then match
+ either spelling.
+</para>
- Revision 1.89 2002/04/23 21:05:28 oes
- Added hint for startup on Red Hat
+<para>
+ <emphasis><literal>/.*/advert[0-9]+\.(gif|jpe?g)</literal></emphasis> - Again
+ another path statement with forward slashes. Anything in the square brackets
+ <quote>[ ]</quote> can be matched. This is using <quote>0-9</quote> as a
+ shorthand expression to mean any digit one through nine. It is the same as
+ saying <quote>0123456789</quote>. So any digit matches. The <quote>+</quote>
+ means one or more of the preceding expression must be included. The preceding
+ expression here is what is in the square brackets -- in this case, any digit
+ one through nine. Then, at the end, we have a grouping: <quote>(gif|jpe?g)</quote>.
+ This includes a <quote>|</quote>, so this needs to match the expression on
+ either side of that bar character also. A simple <quote>gif</quote> on one side, and the other
+ side will in turn match either <quote>jpeg</quote> or <quote>jpg</quote>,
+ since the <quote>?</quote> means the letter <quote>e</quote> is optional and
+ can be matched once or not at all. So we are building an expression here to
+ match image GIF or JPEG type image file. It must include the literal
+ string <quote>advert</quote>, then one or more digits, and a <quote>.</quote>
+ (which is now a literal, and not a special character, since it is escaped
+ with <quote>\</quote>), and lastly either <quote>gif</quote>, or
+ <quote>jpeg</quote>, or <quote>jpg</quote>. Some possible matches would
+ include: <quote>//advert1.jpg</quote>,
+ <quote>/nasty/ads/advert1234.gif</quote>,
+ <quote>/banners/from/hell/advert99.jpg</quote>. It would not match
+ <quote>advert1.gif</quote> (no leading slash), or
+ <quote>/adverts232.jpg</quote> (the expression does not include an
+ <quote>s</quote>), or <quote>/advert1.jsp</quote> (<quote>jsp</quote> is not
+ in the expression anywhere).
+</para>
- Revision 1.88 2002/04/23 05:37:54 hal9
- Add AmigaOS install stuff.
+<para>
+ We are barely scratching the surface of regular expressions here so that you
+ can understand the default <application>Privoxy</application>
+ configuration files, and maybe use this knowledge to customize your own
+ installation. There is much, much more that can be done with regular
+ expressions. Now that you know enough to get started, you can learn more on
+ your own :/
+</para>
- Revision 1.87 2002/04/23 02:53:15 david__schmidt
- Updated Mac OS X installation section
- Added a few English tweaks here an there
+<para>
+ More reading on Perl Compatible Regular expressions:
+ <ulink url="http://perldoc.perl.org/perlre.html">http://perldoc.perl.org/perlre.html</ulink>
+</para>
- Revision 1.86 2002/04/21 01:46:32 hal9
- Re-write actions section.
+<para>
+ For information on regular expression based substitutions and their applications
+ in filters, please see the <link linkend="filter-file">filter file tutorial</link>
+ in this manual.
+</para>
+</sect2>
- Revision 1.85 2002/04/18 21:23:23 hal9
- Fix ugly typo (mine).
+<!-- ~ End section ~ -->
- Revision 1.84 2002/04/18 21:17:13 hal9
- Spell Redhat correctly (ie Red Hat). A few minor grammar corrections.
- Revision 1.83 2002/04/18 18:21:12 oes
- Added RPM install detail
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="internal-pages">
+<title>Privoxy's Internal Pages</title>
- Revision 1.82 2002/04/18 12:04:50 oes
- Cosmetics
+<para>
+ Since <application>Privoxy</application> proxies each requested
+ web page, it is easy for <application>Privoxy</application> to
+ trap certain special URLs. In this way, we can talk directly to
+ <application>Privoxy</application>, and see how it is
+ configured, see how our rules are being applied, change these
+ rules and other configuration options, and even turn
+ <application>Privoxy's</application> filtering off, all with
+ a web browser.
- Revision 1.81 2002/04/18 11:50:24 oes
- Extended Install section - needs fixing by packagers
+</para>
- Revision 1.80 2002/04/18 10:45:19 oes
- Moved text to buildsource.sgml, renamed some filters, details
+<para>
+ The URLs listed below are the special ones that allow direct access
+ to <application>Privoxy</application>. Of course,
+ <application>Privoxy</application> must be running to access these. If
+ not, you will get a friendly error message. Internet access is not
+ necessary either.
+</para>
- Revision 1.79 2002/04/18 03:18:06 hal9
- Spellcheck, and minor touchups.
+<para>
+ <itemizedlist>
- Revision 1.78 2002/04/17 18:04:16 oes
- Proofreading part 2
+ <listitem>
+ <para>
+ Privoxy main page:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
+ </para>
+ </blockquote>
+ <para>
+ There is a shortcut: <ulink url="http://p.p/">http://p.p/</ulink> (But it
+ doesn't provide a fall-back to a real page, in case the request is not
+ sent through <application>Privoxy</application>)
+ </para>
+ </listitem>
- Revision 1.77 2002/04/17 13:51:23 oes
- Proofreading, part one
+ <listitem>
+ <para>
+ Show information about the current configuration, including viewing and
+ editing of actions files:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
+ </para>
+ </blockquote>
+ </listitem>
- Revision 1.76 2002/04/16 04:25:51 hal9
- -Added 'Note to Upgraders' and re-ordered the 'Quickstart' section.
- -Note about proxy may need requests to re-read config files.
+ <listitem>
+ <para>
+ Show the source code version numbers:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/show-version">http://config.privoxy.org/show-version</ulink>
+ </para>
+ </blockquote>
+ </listitem>
- Revision 1.75 2002/04/12 02:08:48 david__schmidt
- Remove OS/2 building info... it is already in the developer-manual
+ <listitem>
+ <para>
+ Show the browser's request headers:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/show-request">http://config.privoxy.org/show-request</ulink>
+ </para>
+ </blockquote>
+ </listitem>
- Revision 1.74 2002/04/11 00:54:38 hal9
- Add small section on submitting actions.
+ <listitem>
+ <para>
+ Show which actions apply to a URL and why:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
+ </para>
+ </blockquote>
+ </listitem>
- Revision 1.73 2002/04/10 18:45:15 swa
- generated
+ <listitem>
+ <para>
+ Toggle Privoxy on or off. This feature can be turned off/on in the main
+ <filename>config</filename> file. When toggled <quote>off</quote>, <quote>Privoxy</quote>
+ continues to run, but only as a pass-through proxy, with no actions taking
+ place:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
+ </para>
+ </blockquote>
+ <para>
+ Short cuts. Turn off, then on:
+ </para>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/toggle?set=disable">http://config.privoxy.org/toggle?set=disable</ulink>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <ulink url="http://config.privoxy.org/toggle?set=enable">http://config.privoxy.org/toggle?set=enable</ulink>
+ </para>
+ </blockquote>
+ </listitem>
- Revision 1.72 2002/04/10 04:06:19 hal9
- Added actions feedback to Bookmarklets section
+ </itemizedlist>
+</para>
- Revision 1.71 2002/04/08 22:59:26 hal9
- Version update. Spell chkconfig correctly :)
+</sect2>
- Revision 1.70 2002/04/08 20:53:56 swa
- ?
- Revision 1.69 2002/04/06 05:07:29 hal9
- -Add privoxy-man-page.sgml, for man page.
- -Add authors.sgml for AUTHORS (and p-authors.sgml)
- -Reworked various aspects of various docs.
- -Added additional comments to sub-docs.
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="chain">
+<title>Chain of Events</title>
+<para>
+ Let's take a quick look at how some of <application>Privoxy's</application>
+ core features are triggered, and the ensuing sequence of events when a web
+ page is requested by your browser:
+</para>
- Revision 1.68 2002/04/04 18:46:47 swa
- consistent look. reuse of copyright, history et. al.
+<para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ First, your web browser requests a web page. The browser knows to send
+ the request to <application>Privoxy</application>, which will in turn,
+ relay the request to the remote web server after passing the following
+ tests:
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ <application>Privoxy</application> traps any request for its own internal CGI
+ pages (e.g <ulink url="http://p.p/">http://p.p/</ulink>) and sends the CGI page back to the browser.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Next, <application>Privoxy</application> checks to see if the URL
+ matches any <link
+ linkend="BLOCK"><quote>+block</quote></link> patterns. If
+ so, the URL is then blocked, and the remote web server will not be contacted.
+ <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>
+ and
+ <link linkend="HANDLE-AS-EMPTY-DOCUMENT"><quote>+handle-as-empty-document</quote></link>
+ are then checked, and if there is no match, an
+ HTML <quote>BLOCKED</quote> page is sent back to the browser. Otherwise, if
+ it does match, an image is returned for the former, and an empty text
+ document for the latter. The type of image would depend on the setting of
+ <link linkend="SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></link>
+ (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Untrusted URLs are blocked. If URLs are being added to the
+ <filename>trust</filename> file, then that is done.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ If the URL pattern matches the <link
+ linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link> action,
+ it is then processed. Unwanted parts of the requested URL are stripped.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Now the rest of the client browser's request headers are processed. If any
+ of these match any of the relevant actions (e.g. <link
+ linkend="HIDE-USER-AGENT"><quote>+hide-user-agent</quote></link>,
+ etc.), headers are suppressed or forged as determined by these actions and
+ their parameters.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Now the web server starts sending its response back (i.e. typically a web
+ page).
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ First, the server headers are read and processed to determine, among other
+ things, the MIME type (document type) and encoding. The headers are then
+ filtered as determined by the
+ <link linkend="CRUNCH-INCOMING-COOKIES"><quote>+crunch-incoming-cookies</quote></link>,
+ <link linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>,
+ and <link linkend="DOWNGRADE-HTTP-VERSION"><quote>+downgrade-http-version</quote></link>
+ actions.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ If any <link linkend="FILTER"><quote>+filter</quote></link> action
+ or <link
+ linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
+ action applies (and the document type fits the action), the rest of the page is
+ read into memory (up to a configurable limit). Then the filter rules (from
+ <filename>default.filter</filename> and any other filter files) are
+ processed against the buffered content. Filters are applied in the order
+ they are specified in one of the filter files. Animated GIFs, if present,
+ are reduced to either the first or last frame, depending on the action
+ setting.The entire page, which is now filtered, is then sent by
+ <application>Privoxy</application> back to your browser.
+ </para>
+ <para>
+ If neither a <link linkend="FILTER"><quote>+filter</quote></link> action
+ or <link
+ linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
+ matches, then <application>Privoxy</application> passes the raw data through
+ to the client browser as it becomes available.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ As the browser receives the now (possibly filtered) page content, it
+ reads and then requests any URLs that may be embedded within the page
+ source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
+ frames), sounds, etc. For each of these objects, the browser issues a
+ separate request (this is easily viewable in <application>Privoxy's</application>
+ logs). And each such request is in turn processed just as above. Note that a
+ complex web page will have many, many such embedded URLs. If these
+ secondary requests are to a different server, then quite possibly a very
+ differing set of actions is triggered.
+ </para>
+ </listitem>
- Revision 1.67 2002/04/04 17:27:57 swa
- more single file to be included at multiple points. make maintaining easier
+ </itemizedlist>
+</para>
+<para>
+ NOTE: This is somewhat of a simplistic overview of what happens with each URL
+ request. For the sake of brevity and simplicity, we have focused on
+ <application>Privoxy's</application> core features only.
+</para>
- Revision 1.66 2002/04/04 06:48:37 hal9
- Structural changes to allow for conditional inclusion/exclusion of content
- based on entity toggles, e.g. 'entity % p-not-stable "INCLUDE"'. And
- definition of internal entities, e.g. 'entity p-version "2.9.13"' that will
- eventually be set by Makefile.
- More boilerplate text for use across multiple docs.
+</sect2>
- Revision 1.65 2002/04/03 19:52:07 swa
- enhance squid section due to user suggestion
- Revision 1.64 2002/04/03 03:53:43 hal9
- A few minor bug fixes, and touch ups. Ready for review.
+<!-- ~~~~~ New section ~~~~~ -->
+<sect2 id="actionsanat">
+<title>Troubleshooting: Anatomy of an Action</title>
- Revision 1.63 2002/04/01 16:24:49 hal9
- Define entities to include boilerplate text. See doc/source/*.
+<para>
+ The way <application>Privoxy</application> applies
+ <link linkend="ACTIONS">actions</link> and <link linkend="FILTER">filters</link>
+ to any given URL can be complex, and not always so
+ easy to understand what is happening. And sometimes we need to be able to
+ <emphasis>see</emphasis> just what <application>Privoxy</application> is
+ doing. Especially, if something <application>Privoxy</application> is doing
+ is causing us a problem inadvertently. It can be a little daunting to look at
+ the actions and filters files themselves, since they tend to be filled with
+ <link linkend="regex">regular expressions</link> whose consequences are not
+ always so obvious.
+</para>
- Revision 1.62 2002/03/30 04:15:53 hal9
- - Fix privoxy.org/config links.
- - Paste in Bookmarklets from Toggle page.
- - Move Quickstart nearer top, and minor rework.
+<para>
+ One quick test to see if <application>Privoxy</application> is causing a problem
+ or not, is to disable it temporarily. This should be the first troubleshooting
+ step (be sure to flush caches afterward!). Looking at the
+ logs is a good idea too. (Note that both the toggle feature and logging are
+ enabled via <filename>config</filename> file settings, and may need to be
+ turned <quote>on</quote>.)
+</para>
+<para>
+ Another easy troubleshooting step to try is if you have done any
+ customization of your installation, revert back to the installed
+ defaults and see if that helps. There are times the developers get complaints
+ about one thing or another, and the problem is more related to a customized
+ configuration issue.
+</para>
- Revision 1.61 2002/03/29 01:31:08 hal9
- Minor update.
+<para>
+ <application>Privoxy</application> also provides the
+ <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
+ page that can show us very specifically how <application>actions</application>
+ are being applied to any given URL. This is a big help for troubleshooting.
+</para>
- Revision 1.60 2002/03/27 01:57:34 hal9
- Added more to Anatomy section.
+<para>
+ First, enter one URL (or partial URL) at the prompt, and then
+ <application>Privoxy</application> will tell us
+ how the current configuration will handle it. This will not
+ help with filtering effects (i.e. the <link
+ linkend="FILTER"><quote>+filter</quote></link> action) from
+ one of the filter files since this is handled very
+ differently and not so easy to trap! It also will not tell you about any other
+ URLs that may be embedded within the URL you are testing. For instance, images
+ such as ads are expressed as URLs within the raw page source of HTML pages. So
+ you will only get info for the actual URL that is pasted into the prompt area
+ -- not any sub-URLs. If you want to know about embedded URLs like ads, you
+ will have to dig those out of the HTML source. Use your browser's <quote>View
+ Page Source</quote> option for this. Or right click on the ad, and grab the
+ URL.
+</para>
- Revision 1.59 2002/03/27 00:54:33 hal9
- Touch up intro for new name.
+<para>
+ Let's try an example, <ulink url="http://google.com">google.com</ulink>,
+ and look at it one section at a time in a sample configuration (your real
+ configuration may vary):
+</para>
- Revision 1.58 2002/03/26 22:29:55 swa
- we have a new homepage!
+<para>
+ <screen>
+ Matches for http://www.google.com:
- Revision 1.57 2002/03/24 20:33:30 hal9
- A few minor catch ups with name change.
+ In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
- Revision 1.56 2002/03/24 16:17:06 swa
- configure needs to be generated.
+ {+change-x-forwarded-for{block}
+ +deanimate-gifs {last}
+ +fast-redirects {check-decoded-url}
+ +filter {refresh-tags}
+ +filter {img-reorder}
+ +filter {banners-by-size}
+ +filter {webbugs}
+ +filter {jumping-windows}
+ +filter {ie-exploits}
+ +hide-from-header {block}
+ +hide-referrer {forge}
+ +session-cookies-only
+ +set-image-blocker {pattern}
+/
- Revision 1.55 2002/03/24 16:08:08 swa
- we are too lazy to make a block-built
- privoxy logo. hence removed the option.
+ { -session-cookies-only }
+ .google.com
- Revision 1.54 2002/03/24 15:46:20 swa
- name change related issue.
+ { -fast-redirects }
+ .google.com
- Revision 1.53 2002/03/24 11:51:00 swa
- name change. changed filenames.
+In file: user.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
+(no matches in this file)
+</screen>
+</para>
- Revision 1.52 2002/03/24 11:01:06 swa
- name change
+<para>
+ This is telling us how we have defined our
+ <link linkend="ACTIONS"><quote>actions</quote></link>, and
+ which ones match for our test case, <quote>google.com</quote>.
+ Displayed is all the actions that are available to us. Remember,
+ the <literal>+</literal> sign denotes <quote>on</quote>. <literal>-</literal>
+ denotes <quote>off</quote>. So some are <quote>on</quote> here, but many
+ are <quote>off</quote>. Each example we try may provide a slightly different
+ end result, depending on our configuration directives.
+</para>
+<para>
+ The first listing
+ is for our <filename>default.action</filename> file. The large, multi-line
+ listing, is how the actions are set to match for all URLs, i.e. our default
+ settings. If you look at your <quote>actions</quote> file, this would be the
+ section just below the <quote>aliases</quote> section near the top. This
+ will apply to all URLs as signified by the single forward slash at the end
+ of the listing -- <quote> / </quote>.
+</para>
- Revision 1.51 2002/03/23 15:13:11 swa
- renamed every reference to the old name with foobar.
- fixed "application foobar application" tag, fixed
- "the foobar" with "foobar". left junkbustser in cvs
- comments and remarks to history untouched.
+<para>
+ But we have defined additional actions that would be exceptions to these general
+ rules, and then we list specific URLs (or patterns) that these exceptions
+ would apply to. Last match wins. Just below this then are two explicit
+ matches for <quote>.google.com</quote>. The first is negating our previous
+ cookie setting, which was for <link
+ linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>
+ (i.e. not persistent). So we will allow persistent cookies for google, at
+ least that is how it is in this example. The second turns
+ <emphasis>off</emphasis> any <link
+ linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link>
+ action, allowing this to take place unmolested. Note that there is a leading
+ dot here -- <quote>.google.com</quote>. This will match any hosts and
+ sub-domains, in the google.com domain also, such as
+ <quote>www.google.com</quote> or <quote>mail.google.com</quote>. But it would not
+ match <quote>www.google.de</quote>! So, apparently, we have these two actions
+ defined as exceptions to the general rules at the top somewhere in the lower
+ part of our <filename>default.action</filename> file, and
+ <quote>google.com</quote> is referenced somewhere in these latter sections.
+</para>
- Revision 1.50 2002/03/23 05:06:21 hal9
- Touch up.
+<para>
+ Then, for our <filename>user.action</filename> file, we again have no hits.
+ So there is nothing google-specific that we might have added to our own, local
+ configuration. If there was, those actions would over-rule any actions from
+ previously processed files, such as <filename>default.action</filename>.
+ <filename>user.action</filename> typically has the last word. This is the
+ best place to put hard and fast exceptions,
+</para>
- Revision 1.49 2002/03/21 17:01:05 hal9
- New section in Appendix.
+<para>
+ And finally we pull it all together in the bottom section and summarize how
+ <application>Privoxy</application> is applying all its <quote>actions</quote>
+ to <quote>google.com</quote>:
- Revision 1.48 2002/03/12 06:33:01 hal9
- Catching up to Andreas and re_filterfile changes.
+</para>
- Revision 1.47 2002/03/11 13:13:27 swa
- correct feedback channels
+<para>
+ <screen>
- Revision 1.46 2002/03/10 00:51:08 hal9
- Added section on JB internal pages in Appendix.
+ Final results:
- Revision 1.45 2002/03/09 17:43:53 swa
- more distros
+ -add-header
+ -block
+ +change-x-forwarded-for{block}
+ -client-header-filter{hide-tor-exit-notation}
+ -content-type-overwrite
+ -crunch-client-header
+ -crunch-if-none-match
+ -crunch-incoming-cookies
+ -crunch-outgoing-cookies
+ -crunch-server-header
+ +deanimate-gifs {last}
+ -downgrade-http-version
+ -fast-redirects
+ -filter {js-events}
+ -filter {content-cookies}
+ -filter {all-popups}
+ -filter {banners-by-link}
+ -filter {tiny-textforms}
+ -filter {frameset-borders}
+ -filter {demoronizer}
+ -filter {shockwave-flash}
+ -filter {quicktime-kioskmode}
+ -filter {fun}
+ -filter {crude-parental}
+ -filter {site-specifics}
+ -filter {js-annoyances}
+ -filter {html-annoyances}
+ +filter {refresh-tags}
+ -filter {unsolicited-popups}
+ +filter {img-reorder}
+ +filter {banners-by-size}
+ +filter {webbugs}
+ +filter {jumping-windows}
+ +filter {ie-exploits}
+ -filter {google}
+ -filter {yahoo}
+ -filter {msn}
+ -filter {blogspot}
+ -filter {no-ping}
+ -force-text-mode
+ -handle-as-empty-document
+ -handle-as-image
+ -hide-accept-language
+ -hide-content-disposition
+ +hide-from-header {block}
+ -hide-if-modified-since
+ +hide-referrer {forge}
+ -hide-user-agent
+ -limit-connect
+ -overwrite-last-modified
+ -prevent-compression
+ -redirect
+ -server-header-filter{xml-to-html}
+ -server-header-filter{html-to-xml}
+ -session-cookies-only
+ +set-image-blocker {pattern} </screen>
+</para>
- Revision 1.44 2002/03/09 17:08:48 hal9
- New section on Jon's actions file editor, and move some stuff around.
+<para>
+ Notice the only difference here to the previous listing, is to
+ <quote>fast-redirects</quote> and <quote>session-cookies-only</quote>,
+ which are activated specifically for this site in our configuration,
+ and thus show in the <quote>Final Results</quote>.
+</para>
- Revision 1.43 2002/03/08 00:47:32 hal9
- Added imageblock{pattern}.
+<para>
+ Now another example, <quote>ad.doubleclick.net</quote>:
+</para>
- Revision 1.42 2002/03/07 18:16:55 swa
- looks better
+<para>
+ <screen>
- Revision 1.41 2002/03/07 16:46:43 hal9
- Fix a few markup problems for jade.
+ { +block{Domains starts with "ad"} }
+ ad*.
- Revision 1.40 2002/03/07 16:28:39 swa
- provide correct feedback channels
+ { +block{Domain contains "ad"} }
+ .ad.
- Revision 1.39 2002/03/06 16:19:28 hal9
- Note on perceived filtering slowdown per FR.
+ { +block{Doubleclick banner server} +handle-as-image }
+ .[a-vx-z]*.doubleclick.net
+</screen>
+</para>
- Revision 1.38 2002/03/05 23:55:14 hal9
- Stupid I did it again. Double hyphen in comment breaks jade.
+<para>
+ We'll just show the interesting part here - the explicit matches. It is
+ matched three different times. Two <quote>+block{}</quote> sections,
+ and a <quote>+block{} +handle-as-image</quote>,
+ which is the expanded form of one of our aliases that had been defined as:
+ <quote>+block-as-image</quote>. (<link
+ linkend="ALIASES"><quote>Aliases</quote></link> are defined in
+ the first section of the actions file and typically used to combine more
+ than one action.)
+</para>
- Revision 1.37 2002/03/05 23:53:49 hal9
- jade barfs on '- -' embedded in comments. - -user option broke it.
+<para>
+ Any one of these would have done the trick and blocked this as an unwanted
+ image. This is unnecessarily redundant since the last case effectively
+ would also cover the first. No point in taking chances with these guys
+ though ;-) Note that if you want an ad or obnoxious
+ URL to be invisible, it should be defined as <quote>ad.doubleclick.net</quote>
+ is done here -- as both a <link
+ linkend="BLOCK"><quote>+block{}</quote></link>
+ <emphasis>and</emphasis> an
+ <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>.
+ The custom alias <quote><literal>+block-as-image</literal></quote> just
+ simplifies the process and make it more readable.
+</para>
- Revision 1.36 2002/03/05 22:53:28 hal9
- Add new - - user option.
+<para>
+ One last example. Let's try <quote>http://www.example.net/adsl/HOWTO/</quote>.
+ This one is giving us problems. We are getting a blank page. Hmmm ...
+</para>
- Revision 1.35 2002/03/05 00:17:27 hal9
- Added section on command line options.
+<para>
+ <screen>
- Revision 1.34 2002/03/04 19:32:07 oes
- Changed default port to 8118
+ Matches for http://www.example.net/adsl/HOWTO/:
- Revision 1.33 2002/03/03 19:46:13 hal9
- Emphasis on where/how to report bugs, etc
+ In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
- Revision 1.32 2002/03/03 09:26:06 joergs
- AmigaOS changes, config is now loaded from PROGDIR: instead of
- AmiTCP:db/junkbuster/ if no configuration file is specified on the
- command line.
+ {-add-header
+ -block
+ +change-x-forwarded-for{block}
+ -client-header-filter{hide-tor-exit-notation}
+ -content-type-overwrite
+ -crunch-client-header
+ -crunch-if-none-match
+ -crunch-incoming-cookies
+ -crunch-outgoing-cookies
+ -crunch-server-header
+ +deanimate-gifs
+ -downgrade-http-version
+ +fast-redirects {check-decoded-url}
+ -filter {js-events}
+ -filter {content-cookies}
+ -filter {all-popups}
+ -filter {banners-by-link}
+ -filter {tiny-textforms}
+ -filter {frameset-borders}
+ -filter {demoronizer}
+ -filter {shockwave-flash}
+ -filter {quicktime-kioskmode}
+ -filter {fun}
+ -filter {crude-parental}
+ -filter {site-specifics}
+ -filter {js-annoyances}
+ -filter {html-annoyances}
+ +filter {refresh-tags}
+ -filter {unsolicited-popups}
+ +filter {img-reorder}
+ +filter {banners-by-size}
+ +filter {webbugs}
+ +filter {jumping-windows}
+ +filter {ie-exploits}
+ -filter {google}
+ -filter {yahoo}
+ -filter {msn}
+ -filter {blogspot}
+ -filter {no-ping}
+ -force-text-mode
+ -handle-as-empty-document
+ -handle-as-image
+ -hide-accept-language
+ -hide-content-disposition
+ +hide-from-header{block}
+ +hide-referer{forge}
+ -hide-user-agent
+ -overwrite-last-modified
+ +prevent-compression
+ -redirect
+ -server-header-filter{xml-to-html}
+ -server-header-filter{html-to-xml}
+ +session-cookies-only
+ +set-image-blocker{blank} }
+ /
- Revision 1.31 2002/03/02 22:45:52 david__schmidt
- Just tweaking
+ { +block{Path contains "ads".} +handle-as-image }
+ /ads
+</screen>
+</para>
- Revision 1.30 2002/03/02 22:00:14 hal9
- Updated 'New Features' list. Ran through spell-checker.
+<para>
+ Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote> in our
+ configuration! But we did not want this at all! Now we see why we get the
+ blank page. It is actually triggering two different actions here, and
+ the effects are aggregated so that the URL is blocked, and &my-app; is told
+ to treat the block as if it were an image. But this is, of course, all wrong.
+ We could now add a new action below this (or better in our own
+ <filename>user.action</filename> file) that explicitly
+ <emphasis>un</emphasis> blocks (
+ <link linkend="BLOCK"><quote>{-block}</quote></link>) paths with
+ <quote>adsl</quote> in them (remember, last match in the configuration
+ wins). There are various ways to handle such exceptions. Example:
+</para>
- Revision 1.29 2002/03/02 20:34:07 david__schmidt
- Update OS/2 build section
+<para>
+ <screen>
- Revision 1.28 2002/02/24 14:34:24 jongfoster
- Formatting changes. Now changing the doctype to DocBook XML 4.1
- will work - no other changes are needed.
+ { -block }
+ /adsl
+</screen>
+</para>
- Revision 1.27 2002/01/11 14:14:32 hal9
- Added a very short section on Templates
+<para>
+ Now the page displays ;-)
+ Remember to flush your browser's caches when making these kinds of changes to
+ your configuration to insure that you get a freshly delivered page! Or, try
+ using <literal>Shift+Reload</literal>.
+</para>
- Revision 1.26 2002/01/09 20:02:50 hal9
- Fix bug re: auto-detect config file changes.
+<para>
+ But now what about a situation where we get no explicit matches like
+ we did with:
+</para>
- Revision 1.25 2002/01/09 18:20:30 hal9
- Touch ups for *.action files.
+<para>
+ <screen>
- Revision 1.24 2001/12/02 01:13:42 hal9
- Fix typo.
+ { +block{Path starts with "ads".} +handle-as-image }
+ /ads
+</screen>
+</para>
- Revision 1.23 2001/12/02 00:20:41 hal9
- Updates for recent changes.
+<para>
+ That actually was very helpful and pointed us quickly to where the problem
+ was. If you don't get this kind of match, then it means one of the default
+ rules in the first section of <filename>default.action</filename> is causing
+ the problem. This would require some guesswork, and maybe a little trial and
+ error to isolate the offending rule. One likely cause would be one of the
+ <link linkend="FILTER"><quote>+filter</quote></link> actions.
+ These tend to be harder to troubleshoot.
+ Try adding the URL for the site to one of aliases that turn off
+ <link linkend="FILTER"><quote>+filter</quote></link>:
+</para>
- Revision 1.22 2001/11/05 23:57:51 hal9
- Minor update for startup now daemon mode.
+<para>
+ <screen>
- Revision 1.21 2001/10/31 21:11:03 hal9
- Correct 2 minor errors
+ { shop }
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .jungle.com
+ .scan.co.uk
+ .forbes.com
+</screen>
+</para>
- Revision 1.18 2001/10/24 18:45:26 hal9
- *** empty log message ***
+<para>
+ <quote><literal>{ shop }</literal></quote> is an <quote>alias</quote> that expands to
+ <quote><literal>{ -filter -session-cookies-only }</literal></quote>.
+ Or you could do your own exception to negate filtering:
- Revision 1.17 2001/10/24 17:10:55 hal9
- Catching up with Jon's recent work, and a few other things.
+</para>
- Revision 1.16 2001/10/21 17:19:21 swa
- wrong url in documentation
+<para>
+ <screen>
- Revision 1.15 2001/10/14 23:46:24 hal9
- Various minor changes. Fleshed out SEE ALSO section.
+ { -filter }
+ # Disable ALL filter actions for sites in this section
+ .forbes.com
+ developer.ibm.com
+ localhost
+</screen>
+</para>
- Revision 1.13 2001/10/10 17:28:33 hal9
- Very minor changes.
+<para>
+ This would turn off all filtering for these sites. This is best
+ put in <filename>user.action</filename>, for local site
+ exceptions. Note that when a simple domain pattern is used by itself (without
+ the subsequent path portion), all sub-pages within that domain are included
+ automatically in the scope of the action.
+</para>
- Revision 1.12 2001/09/28 02:57:04 hal9
- Ditto :/
+<para>
+ Images that are inexplicably being blocked, may well be hitting the
+<link linkend="FILTER-BANNERS-BY-SIZE"><quote>+filter{banners-by-size}</quote></link>
+ rule, which assumes
+ that images of certain sizes are ad banners (works well
+ <emphasis>most of the time</emphasis> since these tend to be standardized).
+</para>
- Revision 1.11 2001/09/28 02:25:20 hal9
- Ditto.
+<para>
+ <quote><literal>{ fragile }</literal></quote> is an alias that disables most
+ actions that are the most likely to cause trouble. This can be used as a
+ last resort for problem sites.
+</para>
+<para>
+ <screen>
- Revision 1.9 2001/09/27 23:50:29 hal9
- A few changes. A short section on regular expression in appendix.
+ { fragile }
+ # Handle with care: easy to break
+ mail.google.
+ mybank.example.com</screen>
+</para>
- Revision 1.8 2001/09/25 00:34:59 hal9
- Some additions, and re-arranging.
- Revision 1.7 2001/09/24 14:31:36 hal9
- Diddling.
+<para>
+ <emphasis>Remember to flush caches!</emphasis> Note that the
+ <literal>mail.google</literal> reference lacks the TLD portion (e.g.
+ <quote>.com</quote>). This will effectively match any TLD with
+ <literal>google</literal> in it, such as <literal>mail.google.de.</literal>,
+ just as an example.
+</para>
+<para>
+ If this still does not work, you will have to go through the remaining
+ actions one by one to find which one(s) is causing the problem.
+</para>
- Revision 1.6 2001/09/24 14:10:32 hal9
- Including David's OS/2 installation instructions.
+</sect2>
- Revision 1.2 2001/09/13 15:27:40 swa
- cosmetics
+</sect1>
- Revision 1.1 2001/09/12 15:36:41 swa
- source files for junkbuster documentation
+ <!--
- Revision 1.3 2001/09/10 17:43:59 swa
- first proposal of a structure.
+ This program is free software; you can redistribute it
+ and/or modify it under the terms of the GNU General
+ Public License as published by the Free Software
+ Foundation; either version 2 of the License, or (at
+ your option) any later version.
- Revision 1.2 2001/06/13 14:28:31 swa
- docs should have an author.
+ This program is distributed in the hope that it will
+ be useful, but WITHOUT ANY WARRANTY; without even the
+ implied warranty of MERCHANTABILITY or FITNESS FOR A
+ PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
- Revision 1.1 2001/06/13 14:20:37 swa
- first import of project's documentation for the webserver.
+ The GNU General Public License should be included with
+ this file. If not, you can view it at
+ http://www.gnu.org/copyleft/gpl.html
+ or write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ USA
-->
projects / privoxy.git / blobdiff