X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Fsource%2Fuser-manual.sgml;h=b4ad6a3b873d08378acd05eab66b0c37718f9c55;hp=017fdf9c9ca465ca8c6fd5fa4395f4eba2174433;hb=9448b3b6afaaa1ba52b6dd0995052ace74415798;hpb=f2ec64186e9816a55e1d24a1a85685f434cd3dd7 diff --git a/doc/source/user-manual.sgml b/doc/source/user-manual.sgml index 017fdf9c..b4ad6a3b 100644 --- a/doc/source/user-manual.sgml +++ b/doc/source/user-manual.sgml @@ -9,9 +9,11 @@ + - + + @@ -34,9 +36,9 @@ 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 2.203 2016/02/26 12:27:32 fabiankeil Exp $ - Copyright (C) 2001-2011 Privoxy Developers http://www.privoxy.org/ + Copyright (C) 2001-2014 Privoxy Developers http://www.privoxy.org/ See LICENSE. ======================================================================== @@ -55,12 +57,12 @@ - Copyright &my-copy; 2001-2011 by + Copyright &my-copy; 2001-2014 by Privoxy Developers -$Id: user-manual.sgml,v 2.135 2011/09/04 11:10:12 fabiankeil Exp $ +$Id: user-manual.sgml,v 2.203 2016/02/26 12:27:32 fabiankeil Exp $ - -Red Hat and Fedora RPMs - - - RPMs can be installed with rpm -Uvh privoxy-&p-version;-1.rpm, - and will use /etc/privoxy for the location - of configuration files. - - - - Note that on Red Hat, Privoxy will - not be automatically started on system boot. You will - need to enable that using chkconfig, - ntsysv, or similar methods. - - - - If you have problems with failed dependencies, try rebuilding the SRC RPM: - rpm --rebuild privoxy-&p-version;-1.src.rpm. This - will use your locally installed libraries and RPM version. - - - - Also note that if you have a Junkbuster RPM installed - on your system, you need to remove it first, because the packages conflict. - Otherwise, RPM will try to remove Junkbuster - automatically if found, before installing Privoxy. - - - Debian and Ubuntu @@ -262,16 +234,6 @@ How to install the binary packages depends on your operating system: - -Solaris <!--, NetBSD, HP-UX--> - - - Create a new directory, cd to it, then unzip and - untar the archive. For the most part, you'll have to figure out where - things go. - - - OS/2 @@ -301,72 +263,83 @@ How to install the binary packages depends on your operating system: Mac OS X - 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. + + +Installation from ready-built package - 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 - /Library/StartupItems/Privoxy. + 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. - 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. + + + To prevent the privoxy service from automatically starting when your computer + starts up, remove or rename the file /Library/LaunchDaemons/org.ijbswa.privoxy.plist + (on OS X 10.5 and higher) or the folder named + /Library/StartupItems/Privoxy (on OS X 10.4 'Tiger'). - - - -AmigaOS - Copy and then unpack the lha archive to a suitable location. - All necessary files will be installed into Privoxy - 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. + + + To uninstall, run /Applications/Privoxy/uninstall.command as sudo from an + administrator account. - - -FreeBSD - + +Installation from source - Privoxy is part of FreeBSD's Ports Collection, you can build and install - it with cd /usr/ports/www/privoxy; make install clean. + 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. - If you don't use the ports, you can fetch and install - the package with pkg_add -r privoxy. + 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. - The port skeleton and the package can also be downloaded from the - File Release - Page, 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 /Library/LaunchDaemons/org.ijbswa.privoxy.plist + (on OS X 10.5 and higher) or the folder named + /Library/StartupItems/Privoxy (on OS X 10.4 'Tiger'). - - - -Gentoo - Gentoo source packages (Ebuilds) for Privoxy 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 - Privoxy 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. - Before installing Privoxy under Gentoo just do - first emerge --sync to get the latest changes from the - Portage tree. With emerge privoxy you install the latest - version. + To uninstall, run the macsetup module's uninstall.sh as sudo from an + administrator account. + + + +FreeBSD + - Configuration files are in /etc/privoxy, the - documentation is in /usr/share/doc/privoxy-&p-version; - and the Log directory is in /var/log/privoxy. + Privoxy is part of FreeBSD's Ports Collection, you can build and install + it with cd /usr/ports/www/privoxy; make install clean. @@ -402,13 +375,6 @@ How to install the binary packages depends on your operating system: Keeping your Installation Up-to-Date - - As user feedback comes in and development continues, we will make updated versions - of both the main actions file (as a separate - package) and the software itself (including the actions file) available for - download. - If you wish to receive an email notification whenever we release updates of @@ -436,674 +402,154 @@ How to install the binary packages depends on your operating system: What's New in this Release + +&changelog; + + + + +Note to Upgraders + - Privoxy 3.0.17 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 Privoxy: - - - 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. - - - - - 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. - - - - - 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. - - - - - 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. - - - - - The IPv6 code is enabled by default on Windows versions that support it. - Patch submitted by oCameLo in #2942729. - - - - - In mingw32 versions, the user.filter file is reachable through the - GUI, just like default.filter is. Feature request 3040263. - + + + + 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 + diff and maybe patch. + + + 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. + + + + + Note that some installers remove earlier versions completely, + including configuration files, therefore you should really save + any important configuration files! + + + + + On the other hand, other installers don't overwrite existing configuration + files, thinking you will want to do that yourself. + + + + + In the default configuration only fatal errors are logged now. + You can change that in the debug section + 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. + + + + + + Three other config file settings are now off by default: + enable-remote-toggle, + enable-remote-http-toggle, + and enable-edit-actions. + If you use or want these, you will need to explicitly enable them, and + be aware of the security issues involved. + + + + + + + - - -Note to Upgraders - - - A quick list of things to be aware of before upgrading from earlier - versions of Privoxy: - - +Quickstart to Using Privoxy - 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 - diff and maybe patch. - - - 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. - + Install Privoxy. See the Installation Section below for platform specific + information. + - - - Note that some installers remove earlier versions completely, - including configuration files, therefore you should really save - any important configuration files! - - - - - On the other hand, other installers don't overwrite existing configuration - files, thinking you will want to do that yourself. - - - - - standard.action has been merged into - the default.action file. - - - - - In the default configuration only fatal errors are logged now. - You can change that in the debug section - 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. - - - - - - Three other config file settings are now off by default: - enable-remote-toggle, - enable-remote-http-toggle, - and enable-edit-actions. - If you use or want these, you will need to explicitly enable them, and - be aware of the security issues involved. - - - - - - - - - - - - - -Quickstart to Using Privoxy - - - - - - Install Privoxy. See the Installation Section below for platform specific - information. - - - + Advanced users and those who want to offer Privoxy @@ -1178,18 +624,6 @@ How to install the binary packages depends on your operating system: - - Please see the section Contacting the @@ -1617,39 +1051,40 @@ How to install the binary packages depends on your operating system: directory. Except on Win32 where it will try config.txt. - -Red Hat and Fedora + +Debian - A default Red Hat installation may not start &my-app; upon boot. It will use - the file /etc/privoxy/config as its main configuration + We use a script. Note that Debian typically starts &my-app; upon booting per + default. It will use the file + /etc/privoxy/config as its main configuration file. - # /etc/rc.d/init.d/privoxy start + # /etc/init.d/privoxy start + + + +FreeBSD and ElectroBSD - Or ... + To start Privoxy upon booting, add + "privoxy_enable='YES'" to /etc/rc.conf. + Privoxy will use + /usr/local/etc/privoxy/config as its main + configuration file. - - # service privoxy start - + If you installed Privoxy into a jail, the + paths above are relative to the jail root. - - - -Debian - We use a script. Note that Debian typically starts &my-app; upon booting per - default. It will use the file - /etc/privoxy/config as its main configuration - file. + To start Privoxy manually, run: - # /etc/init.d/privoxy start + # service privoxy onestart @@ -1673,15 +1108,21 @@ Click on the &my-app; Icon to start Privoxy. If no co -Solaris, NetBSD, FreeBSD, HP-UX and others +Generic instructions for Unix derivates (Solaris, NetBSD, HP-UX etc.) Example Unix startup command: - # /usr/sbin/privoxy /etc/privoxy/config + # /usr/sbin/privoxy --user privoxy /etc/privoxy/config + + Note that if you installed Privoxy through + a package manager, the package will probably contain a platform-specific + script or configuration file to start Privoxy + upon boot. + @@ -1697,71 +1138,24 @@ Example Unix startup command: Mac OS X - 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. - - - The privoxy service will automatically start after a successful - installation. In addition, the privoxy service will automatically - start 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 - /Library/StartupItems/Privoxy. - - - A simple application named Privoxy Utility has been created which - enables administrators to easily start and stop the privoxy service. - - - 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. - 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 /Library/LaunchDaemons/org.ijbswa.privoxy.plist + (on OS X 10.5 and higher) or the folder named + /Library/StartupItems/Privoxy (on OS X 10.4 'Tiger'). - - - - -AmigaOS - Start Privoxy (with RUN <>NIL:) in your - startnet script (AmiTCP), in - s:user-startup (RoadShow), as startup program in your - startup script (Genesis), or as startup action (Miami and MiamiDx). - Privoxy will automatically quit when you quit your - TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that - Privoxy 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. - -Gentoo - - A script is again used. It will use the file /etc/privoxy/config - as its main configuration file. - - - - /etc/init.d/privoxy start - - - - Note that Privoxy is not automatically started at - boot time by default. You can change this with the rc-update - command. - - - - rc-update add privoxy default - - - - + Controlling Privoxy with Your Web Browser Privoxy's user interface can be reached through the special @@ -2048,10 +1464,7 @@ for details. it as a test to see whether it is Privoxy causing the problem or not. Privoxy continues to run as a proxy in this case, but all manipulation is disabled, i.e. - Privoxy acts like a normal forwarding proxy. There - is even a toggle Bookmarklet offered, so - that you can toggle Privoxy with one click from - your browser. + Privoxy acts like a normal forwarding proxy. @@ -2460,7 +1873,7 @@ for details. - + Finding the Right Mix Note that some actions, like cookie suppression @@ -2485,7 +1898,7 @@ for details. - + How to Edit The easiest way to edit the actions files is with a browser by @@ -2575,23 +1988,23 @@ for details. Generally, an URL pattern has the form - <domain><port>/<path>, where the - <domain>, the <port> + <host><port>/<path>, where the + <host>, the <port> and the <path> are optional. (This is why the special / pattern matches all URLs). Note that the protocol portion of the URL pattern (e.g. http://) should not be included in the pattern. This is assumed already! - 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 Regular Expressions (POSIX 1003.2). The port part of a pattern is a decimal port number preceded by a colon - (:). If the domain part contains a numerical IPv6 address, + (:). If the host part contains a numerical IPv6 address, it has to be put into angle brackets (<, >). @@ -2601,7 +2014,7 @@ for details. www.example.com/ - is a domain-only pattern and will match any request to www.example.com, + is a host-only pattern and will match any request to www.example.com, 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 example.com is different and would NOT match. @@ -2612,7 +2025,7 @@ for details. www.example.com - means exactly the same. For domain-only patterns, the trailing / may + means exactly the same. For host-only patterns, the trailing / may be omitted. @@ -2661,6 +2074,15 @@ for details. + + 10.0.0.1/ + + + Matches any URL with the host address 10.0.0.1. + (Note that the real URL uses plain brackets, not angle brackets.) + + + <2001:db8::1>/ @@ -2684,11 +2106,13 @@ for details. -The Domain Pattern +The Host Pattern - 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: @@ -2795,7 +2219,7 @@ for details. -The Path Pattern +The Path Pattern Privoxy uses modern POSIX 1003.2 @@ -2954,6 +2378,23 @@ for details. + +The Negative Tag Patterns + + + To match requests that do not have a certain tag, specify a negative tag pattern + by prefixing the tag pattern line with either NO-REQUEST-TAG: + or NO-RESPONSE-TAG: instead of TAG:. + + + + Negative tag patterns created with NO-REQUEST-TAG: are checked + after all client headers are scanned, the ones created with NO-RESPONSE-TAG: + are checked after all server headers are scanned. In both cases all the created + tags are considered. + + + @@ -3355,7 +2796,7 @@ for details. Type: - Parameterized. + Multi-value. @@ -3383,7 +2824,7 @@ for details. and use their output as input. - 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. @@ -3405,7 +2846,7 @@ for details. {+client-header-filter{hide-tor-exit-notation}} / - + @@ -3442,7 +2883,7 @@ for details. Type: - Parameterized. + Multi-value. @@ -3499,6 +2940,22 @@ TAG:^User-Agent: fetch libfetch/ TAG:^User-Agent: Ubuntu APT-HTTP/ TAG:^User-Agent: MPlayer/ + + + +# 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$ + @@ -4117,9 +3574,19 @@ new action This is a left-over from the time when Privoxy 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. + + + 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. + + + 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 Privoxy it should be + fixed so the following release works without the work around. @@ -4138,14 +3605,14 @@ problem-host.example.com - -fast-redirects + +external-filter Typical use: - Fool some click-tracking scripts and speed up indirect links. + Modify content using a programming language of your choice. @@ -4153,8 +3620,12 @@ problem-host.example.com Effect: - 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 text/plain MIME type for all files + whose type they don't know.) @@ -4163,27 +3634,25 @@ problem-host.example.com Type: - Parameterized. + Multi-value. Parameter: - - - - simple-check to just search for the string http:// - to detect redirection URLs. - - - - - check-decoded-url to decode URLs (if necessary) before searching - for redirection URLs. - - - + + The name of an external content filter, as defined in the + filter file. + External filters can be defined in one or more files as defined by the + filterfile + option in the config file. + + + When used in its negative form, + and without parameters, all filtering with external + filters is completely disabled. + @@ -4191,23 +3660,109 @@ problem-host.example.com Notes: - Many sites, like yahoo.com, don't just link to other sites. Instead, they - will link to some script on their own servers, giving the destination as a - parameter, which will then redirect you to the final target. URLs - resulting from this scheme typically look like: - http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/. - - - Sometimes, there are even multiple consecutive redirects encoded in the - URL. These redirections via scripts make your web browsing more traceable, - since the server from which you follow such a link can see where you go - to. Apart from that, valuable bandwidth and time is wasted, while your - browser asks the server for one redirect after the other. Plus, it feeds - the advertisers. + External filters are scripts or programs that can modify the content in + case common filters + aren't powerful enough. With the exception that this action doesn't + use pcrs-based filters, the notes in the + filter section apply. - - This feature is currently not very smart and is scheduled for improvement. - If it is enabled by default, you will have to create some exceptions to + + + Currently external filters are executed with &my-app;'s privileges. + Only use external filters you understand and trust. + + + + This feature is experimental, the syntax + may change in the future. + + + + + + + Example usage: + + + +external-filter{fancy-filter} + + + + + + + + +fast-redirects + + + + Typical use: + + Fool some click-tracking scripts and speed up indirect links. + + + + + Effect: + + + Detects redirection URLs and redirects the browser without contacting + the redirection server first. + + + + + + Type: + + + Parameterized. + + + + + Parameter: + + + + + simple-check to just search for the string http:// + to detect redirection URLs. + + + + + check-decoded-url to decode URLs (if necessary) before searching + for redirection URLs. + + + + + + + + Notes: + + + Many sites, like yahoo.com, don't just link to other sites. Instead, they + will link to some script on their own servers, giving the destination as a + parameter, which will then redirect you to the final target. URLs + resulting from this scheme typically look like: + http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/. + + + Sometimes, there are even multiple consecutive redirects encoded in the + URL. These redirections via scripts make your web browsing more traceable, + since the server from which you follow such a link can see where you go + to. Apart from that, valuable bandwidth and time is wasted, while your + browser asks the server for one redirect after the other. Plus, it feeds + the advertisers. + + + This feature is currently not very smart and is scheduled for improvement. + If it is enabled by default, you will have to create some exceptions to this action. It can lead to failures in several ways: @@ -4291,7 +3846,7 @@ problem-host.example.com Type: - Parameterized. + Multi-value. @@ -4399,7 +3954,7 @@ problem-host.example.com - +filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites). + +filter{js-events} # Kill JavaScript event bindings and timers (Radically destructive! Only for extra nasty sites). @@ -4411,15 +3966,15 @@ problem-host.example.com - +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups). + +filter{refresh-tags} # Kill automatic refresh tags if refresh time is larger than 9 seconds. - +filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability. + +filter{unsolicited-popups} # Disable only unsolicited pop-up windows. - +filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability. + +filter{all-popups} # Kill all popups in JavaScript and HTML. @@ -4433,5459 +3988,4672 @@ problem-host.example.com +filter{banners-by-link} # Kill banners by their links to known clicktrackers. - - - +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking). - - - - +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap. - - - - +filter{jumping-windows} # Prevent windows from resizing and moving themselves. - - - - +filter{frameset-borders} # Give frames a border and make them resizable. - - - - +filter{demoronizer} # Fix MS's non-standard use of standard charsets. - - - - +filter{shockwave-flash} # Kill embedded Shockwave Flash objects. - - - - +filter{quicktime-kioskmode} # Make Quicktime movies saveable. - - - - +filter{fun} # Text replacements for subversive browsing fun! - - - - +filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably. - - - - +filter{ie-exploits} # Disable some known Internet Explorer bug exploits. - - - - +filter{site-specifics} # Cure for site-specific problems. Don't apply generally! - - - - +filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags. - - - - +filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement. - - - - +filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation. - - - - +filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation. - - - - +filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this. - - - - - - - - - -force-text-mode - - - - Typical use: - - Force Privoxy to treat a document as if it was in some kind of text format. - - - - - Effect: - - - Declares a document as text, even if the Content-Type: isn't detected as such. - - - - - - Type: - - - Boolean. - - - - - Parameter: - - - N/A - - - - - - Notes: - - - As explained above, - Privoxy tries to only filter files that are - in some kind of text format. The same restrictions apply to - content-type-overwrite. - force-text-mode declares a document as text, - without looking at the Content-Type: first. - - - - Think twice before activating this action. Filtering binary data - with regular expressions can cause file damage. - - - - - - - Example usage: - - - -+force-text-mode - - - - - - - - - - -forward-override - - - - Typical use: - - Change the forwarding settings based on User-Agent or request origin - - - - - Effect: - - - Overrules the forward directives in the configuration file. - - - - - - Type: - - - Multi-value. - - - - - Parameter: - - - - forward . to use a direct connection without any additional proxies. - - - - forward 127.0.0.1:8123 to use the HTTP proxy listening at 127.0.0.1 port 8123. - - - - - forward-socks4a 127.0.0.1:9050 . to use the socks4a proxy listening at - 127.0.0.1 port 9050. Replace forward-socks4a with forward-socks4 - to use a socks4 connection (with local DNS resolution) instead, use forward-socks5 - for socks5 connections (with remote DNS resolution). - - - - - forward-socks4a 127.0.0.1:9050 proxy.example.org:8000 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 forward-socks4a with forward-socks4 to use a socks4 connection - (with local DNS resolution) instead, use forward-socks5 - for socks5 connections (with remote DNS resolution). - - - - - - - - Notes: - - - This action takes parameters similar to the - forward 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. - - - - Please read the description for the forward directives before - using this action. Forwarding to the wrong people will reduce your privacy and increase the - chances of man-in-the-middle attacks. - - - 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. - - - Use the show-url-info CGI page - to verify that your forward settings do what you thought the do. - - - - - - - Example usage: - - - -# Always use direct connections for requests previously tagged as -# User-Agent: fetch libfetch/2.0 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$ - - - - - - - - - - -handle-as-empty-document - - - - Typical use: - - Mark URLs that should be replaced by empty documents if they get blocked - - - - - Effect: - - - This action alone doesn't do anything noticeable. It just marks URLs. - If the block action also applies, - the presence or absence of this mark decides whether an HTML BLOCKED - page, or an empty document will be sent to the client as a substitute for the blocked content. - The empty document isn't literally empty, but actually contains a single space. - - - - - - Type: - - - Boolean. - - - - - Parameter: - - - N/A - - - - - - Notes: - - - Some browsers complain about syntax errors if JavaScript documents - are blocked with Privoxy's - 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. - - - The content type for the empty document can be specified with - content-type-overwrite{}, - but usually this isn't necessary. - - - - - - Example usage: - - - # 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$ - - - - - - - - - - -handle-as-image - - - - Typical use: - - Mark URLs as belonging to images (so they'll be replaced by images if they do get blocked, rather than HTML pages) - - - - - Effect: - - - This action alone doesn't do anything noticeable. It just marks URLs as images. - If the block action also applies, - the presence or absence of this mark decides whether an HTML blocked - page, or a replacement image (as determined by the set-image-blocker action) will be sent to the - client as a substitute for the blocked content. - - - - - - Type: - - - Boolean. - - - - - Parameter: - - - N/A - - - - - - Notes: - - - The below generic example section is actually part of default.action. - It marks all URLs with well-known image file name extensions as images and should - be left intact. - - - Users will probably only want to use the handle-as-image action in conjunction with - block, to block sources of banners, whose URLs don't - reflect the file type, like in the second example section. - - - 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 handle-as-image in this situation will not replace the - ad frame with an image, but lead to error messages. - - - - - - Example usage (sections): - - - # 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 - - - - - - - - - - -hide-accept-language - - - - Typical use: - - Pretend to use different language settings. - - - - - Effect: - - - Deletes or replaces the Accept-Language: HTTP header in client requests. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - Keyword: block, or any user defined value. - - - - - - Notes: - - - Faking the browser's language settings can be useful to make a - foreign User-Agent set with - hide-user-agent - more believable. - - - However some sites with content in different languages check the - Accept-Language: to decide which one to take by default. - Sometimes it isn't possible to later switch to another language without - changing the Accept-Language: header first. - - - Therefore it's a good idea to either only change the - Accept-Language: header to languages you understand, - or to languages that aren't wide spread. - - - Before setting the Accept-Language: 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. - - - - - - Example usage (section): - - - # 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} \ -} -/ - - - - - - - - - -hide-content-disposition - - - - Typical use: - - Prevent download menus for content you prefer to view inside the browser. - - - - - Effect: - - - Deletes or replaces the Content-Disposition: HTTP header set by some servers. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - Keyword: block, or any user defined value. - - - - - - Notes: - - - Some servers set the Content-Disposition: HTTP header for - documents they assume you want to save locally before viewing them. - The Content-Disposition: header contains the file name - the browser is supposed to use by default. - - - In most browsers that understand this header, it makes it impossible to - just view the document, without downloading it first, - even if it's just a simple text file or an image. - - - Removing the Content-Disposition: header helps - to prevent this annoyance, but some browsers additionally check the - Content-Type: 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. - - - 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. - - - This action will probably be removed in the future, - use server-header filters instead. - - - - - - Example usage: - - - # Disarm the download link in Sourceforge's patch tracker -{ -filter \ - +content-type-overwrite{text/plain}\ - +hide-content-disposition{block} } - .sourceforge.net/tracker/download\.php - - - - - - - - - -hide-if-modified-since - - - - Typical use: - - Prevent yet another way to track the user's steps between sessions. - - - - - Effect: - - - Deletes the If-Modified-Since: HTTP client header or modifies its value. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - Keyword: block, or a user defined value that specifies a range of hours. - - - - - - Notes: - - - Removing this header is useful for filter testing, where you want to force a real - reload instead of getting status code 304, which would cause the - browser to use a cached copy of the page. - - - Instead of removing the header, hide-if-modified-since 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 - Privoxy does the rest. A negative value means - subtracting, a positive value adding. - - - Randomizing the value of the If-Modified-Since: 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. - - - It is a good idea to only use a small negative value and let - overwrite-last-modified - handle the greater changes. - - - It is also recommended to use this action together with - crunch-if-none-match, - otherwise it's more or less pointless. - - - - - - Example usage (section): - - - # 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} -/ - - - - - - - - - -hide-from-header - - - - Typical use: - - Keep your (old and ill) browser from telling web servers your email address - - - - - Effect: - - - Deletes any existing From: HTTP header, or replaces it with the - specified string. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - Keyword: block, or any user defined value. - - - - - - Notes: - - - The keyword block will completely remove the header - (not to be confused with the block - action). - - - 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. - - - This action is rarely needed, as modern web browsers don't send - From: headers anymore. - - - - - - Example usage: - - - +hide-from-header{block} or - +hide-from-header{spam-me-senseless@sittingduck.example.com} - - - - - - - - - -hide-referrer - - - - Typical use: - - Conceal which link you followed to get to a particular site - - - - - Effect: - - - Deletes the Referer: (sic) HTTP header from the client request, - or replaces it with a forged one. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - - conditional-block to delete the header completely if the host has changed. - - - conditional-forge to forge the header if the host has changed. - - - block to delete the header unconditionally. - - - forge to pretend to be coming from the homepage of the server we are talking to. - - - Any other string to set a user defined referrer. - - - - - - - Notes: - - - conditional-block 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. - - - Leaving the referrer unmodified for requests on the same host - allows the server owner to see the visitor's click path, - 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. - - - 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. - - - Both conditional-block and forge - 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. - - - hide-referer is an alternate spelling of - hide-referrer and the two can be can be freely - substituted with each other. (referrer is the - correct English spelling, however the HTTP specification has a bug - it - requires it to be spelled as referer.) - - - - - - Example usage: - - - +hide-referrer{forge} or - +hide-referrer{http://www.yahoo.com/} - - - - - - - - - -hide-user-agent - - - - Typical use: - - Try to conceal your type of browser and client operating system - - - - - Effect: - - - Replaces the value of the User-Agent: HTTP header - in client requests with the specified value. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - Any user-defined string. - - - - - - Notes: - - - - 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 NOT the right thing to do: good web sites - work browser-independently). - - - - Using this action in multi-user setups or wherever different types of - browsers will access the same Privoxy is - not recommended. 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). - - - More information on known user-agent strings can be found at - http://www.user-agents.org/ - and - http://en.wikipedia.org/wiki/User_agent. - - - - - - Example usage: - - - +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)} - - - - - - - - - -limit-connect - - - - Typical use: - - Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted sites - - - - - Effect: - - - Specifies to which ports HTTP CONNECT requests are allowable. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - A comma-separated list of ports or port ranges (the latter using dashes, with the minimum - defaulting to 0 and the maximum to 65K). - - - - - - Notes: - - - By default, i.e. if no limit-connect action applies, - Privoxy allows HTTP CONNECT requests to all - ports. Use limit-connect if fine-grained control - is desired for some or all destinations. - - - The CONNECT methods exists in HTTP to allow access to secure websites - (https:// 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. - - - Privoxy 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. - - - - - - Example usages: - - - - - - +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 - - - - - - - - -prevent-compression - - - - Typical use: - - - Ensure that servers send the content uncompressed, so it can be - passed through filters. - - - - - - Effect: - - - Removes the Accept-Encoding header which can be used to ask for compressed transfer. - - - - - - Type: - - - Boolean. - - - - - Parameter: - - - N/A - - - - - - Notes: - - - More and more websites send their content compressed by default, which - is generally a good idea and saves bandwidth. But the filter and - deanimate-gifs - actions need access to the uncompressed data. - - - 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. - - - 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. - - - 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. - - - 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 - prevent-compression per default, you might want to add - exceptions for those sites. See the example for how to do that. - - - - - - Example usage (sections): - - - -# 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/ - - - - - - - - - - -overwrite-last-modified - - - - Typical use: - - Prevent yet another way to track the user's steps between sessions. - - - - - Effect: - - - Deletes the Last-Modified: HTTP server header or modifies its value. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - One of the keywords: block, reset-to-request-time - and randomize - - - - - - Notes: - - - Removing the Last-Modified: header is useful for filter - testing, where you want to force a real reload instead of getting status - code 304, which would cause the browser to reuse the old - version of the page. - - - The randomize option overwrites the value of the - Last-Modified: 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 Last-Modified: - header to track visits without using cookies. Randomize - makes it impossible and the browser can still revalidate cached documents. - - - reset-to-request-time overwrites the value of the - Last-Modified: header with the current time. You could use - this option together with - hide-if-modified-since - to further customize your random range. - - - The preferred parameter here is randomize. It is safe - to use, as long as the time settings are more or less correct. - If the server sets the Last-Modified: 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 - hided-if-modified-since, - just to be sure. - - - It is also recommended to use this action together with - crunch-if-none-match. - - - - - - Example usage: - - - # Let the browser revalidate without being tracked across sessions -{ +hide-if-modified-since{-60} \ - +overwrite-last-modified{randomize} \ - +crunch-if-none-match} -/ - - - - - - - - - -redirect - - - - Typical use: - - - Redirect requests to other sites. - - - - - - Effect: - - - Convinces the browser that the requested document has been moved - to another location and the browser should get it from there. - - - - - - Type: - - - Parameterized - - - - - Parameter: - - - An absolute URL or a single pcrs command. - - - - - - Notes: - - - 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. - - - This action will be ignored if you use it together with - block. - It can be combined with - fast-redirects{check-decoded-url} - to redirect to a decoded version of a rewritten URL. - - - 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. - - - In case of problems with your redirects, or simply to watch - them working, enable debug 128. - - - - - - Example usages: - - - # 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/ - - - - - - - - - - -server-header-filter - - - - Typical use: - - - Rewrite or remove single server headers. - - - - - - Effect: - - - All server headers to which this action applies are filtered on-the-fly - through the specified regular expression based substitutions. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - The name of a server-header filter, as defined in one of the - filter files. - - - - - - Notes: - - - 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. - - - Server-header filters are executed after the other header actions have finished - and use their output as input. - - - Please refer to the filter file chapter - to learn which server-header filters are available by default, and how to - create your own. - - - - - - Example usage (section): - - - -{+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 - - - - - - - - - - - -server-header-tagger - - - - Typical use: - - - Enable or disable filters based on the Content-Type header. - - - - - - Effect: - - - 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. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - The name of a server-header tagger, as defined in one of the - filter files. - - - - - - Notes: - - - Server-header taggers are applied to each header on its own, - and as the header isn't modified, each tagger sees - the original. - - - 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 (redirect - and block). - - - Obviously crunching based on tags created by server-header taggers - doesn't prevent the request from showing up in the server's log file. - - - - - - - Example usage (section): - - - -# Tag every request with the content type declared by the server -{+server-header-tagger{content-type}} -/ - - - - - - - - - - - -session-cookies-only - - - - Typical use: - - - Allow only temporary session cookies (for the current - browser session only). - - - - - - Effect: - - - Deletes the expires field from Set-Cookie: - server headers. Most browsers will not store such cookies permanently and - forget them in between sessions. - - - - - - Type: - - - Boolean. - - - - - Parameter: - - - N/A - - - - - - Notes: - - - This is less strict than crunch-incoming-cookies / - crunch-outgoing-cookies and allows you to browse - websites that insist or rely on setting cookies, without compromising your privacy too badly. - - - Most browsers will not permanently store cookies that have been processed by - session-cookies-only 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. - - - It makes no sense at all to use session-cookies-only - together with crunch-incoming-cookies or - crunch-outgoing-cookies. If you do, cookies - will be plainly killed. - - - Note that it is up to the browser how it handles such cookies without an expires - field. If you use an exotic browser, you might want to try it out to be sure. - - - This setting also has no effect on cookies that may have been stored - previously by the browser before starting Privoxy. - These would have to be removed manually. - - - Privoxy also uses - the content-cookies filter - to block some types of cookies. Content cookies are not effected by - session-cookies-only. - - - - - - Example usage: - - - +session-cookies-only - - - - - - - - - -set-image-blocker - - - - Typical use: - - Choose the replacement for blocked images - - - - - Effect: - - - This action alone doesn't do anything noticeable. If both - block and handle-as-image also - apply, i.e. if the request is to be blocked as an image, - then the parameter of this action decides what will be - sent as a replacement. - - - - - - Type: - - - Parameterized. - - - - - Parameter: - - - - - pattern to send a built-in checkerboard pattern image. The image is visually - decent, scales very well, and makes it obvious where banners were busted. - - - - - blank to send a built-in transparent image. This makes banners disappear - completely, but makes it hard to detect where Privoxy has blocked - images on a given page and complicates troubleshooting if Privoxy - has blocked innocent images, like navigation icons. - - - - - target-url to - send a redirect to target-url. You can redirect - to any image anywhere, even in your local filesystem via file:/// URL. - (But note that not all browsers support redirecting to a local file system). - - - A good application of redirects is to use special Privoxy-built-in - URLs, which send the built-in images, as target-url. - This has the same visual effect as specifying blank or pattern in - the first place, but enables your browser to cache the replacement image, instead of requesting - it over and over again. - - - - - - - - Notes: - - - The URLs for the built-in images are http://config.privoxy.org/send-banner?type=type, where type is - either blank or pattern. - - - There is a third (advanced) type, called auto. It is NOT to be - used in set-image-blocker, but meant for use from filters. - Auto will select the type of image that would have applied to the referring page, had it been an image. - - - - - - Example usage: - - - Built-in pattern: - - - +set-image-blocker{pattern} - - - Redirect to the BSD daemon: - - - +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif} - - - Redirect to the built-in pattern for better caching: - - - +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern} - - - - - - - - - -Summary - - 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 Appendix for a brief example on troubleshooting - actions. - - - - - - -Aliases - - Custom actions, known to Privoxy - as aliases, 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, - =, - { and }, but we strongly - recommend that you only use a to z, - 0 to 9, +, and -. - Alias names are not case sensitive, and are not required to start with a - + or - sign, since they are merely textually - expanded. - - - Aliases can be used throughout the actions file, but they must be - defined in a special section at the top of the file! - 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. - - - 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 - shop, you can later change your policy on shops in - one place, and your changes will take effect everywhere - in the actions file where the shop alias is used. Calling aliases - by their purpose also makes your actions files more readable. - - - Currently, there is one big drawback to using aliases, though: - Privoxy'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. - - - - Now let's define some aliases... - - - - - # 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 = +crunch-incoming-cookies +crunch-outgoing-cookies - -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies - +block-as-image = +block{Blocked image.} +handle-as-image - allow-all-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} - - # These aliases define combinations of actions - # that are useful for certain types of sites: - # - fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -prevent-compression - - shop = -crunch-all-cookies -filter{all-popups} - - # Short names for other aliases, for really lazy people ;-) - # - c0 = +crunch-all-cookies - c1 = -crunch-all-cookies - - - - ...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 / pattern): - - - - - # 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 - - - - Aliases like shop and fragile are typically used for - problem sites that require more than one action to be disabled - in order to function properly. - - - - - -Actions Files Tutorial - - The above chapters have shown which actions files - there are and how they are organized, how actions are specified and applied - to URLs, how patterns work, and how to - define and use aliases. Now, let's look at an - example match-all.action, default.action - and user.action file and see how all these pieces come together: - - - -match-all.action - - Remember all actions are disabled when matching starts, - so we have to explicitly enable the ones we want. - - - - While the match-all.action file only contains a - single section, it is probably the most important one. It has only one - pattern, /, but this pattern - matches all URLs. Therefore, the set of - actions used in this default section will - be applied to all requests as a start. It can be partly or - wholly overridden by other actions files like default.action - and user.action, but it will still be largely responsible - for your overall browsing experience. - - - - Again, at the start of matching, all actions are disabled, so there is - no need to disable any actions here. (Remember: a + - preceding the action name enables the action, a - disables!). - Also note how this long line has been made more readable by splitting it into - multiple lines with line continuation. - - - - -{ \ - +change-x-forwarded-for{block} \ - +hide-from-header{block} \ - +set-image-blocker{pattern} \ -} -/ # Match all URLs - - - - - The default behavior is now set. - - - - -default.action - - - If you aren't a developer, there's no need for you to edit the - default.action file. It is maintained by - the &my-app; developers and if you disagree with some of the - sections, you should overrule them in your user.action. - - - - Understanding the default.action file can - help you with your user.action, though. - - - - The first section in this file is a special section for internal use - that prevents older &my-app; versions from reading the file: - - - - -########################################################################## -# Settings -- Don't change! For internal Privoxy use ONLY. -########################################################################## -{{settings}} -for-privoxy-version=3.0.11 - - - - After that comes the (optional) alias section. We'll use the example - section from the above chapter on aliases, - that also explains why and how aliases are used: - - - - -########################################################################## -# Aliases -########################################################################## -{{alias}} - - # These aliases just save typing later: - # (Note that some already use other aliases!) - # - +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies - -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies - +block-as-image = +block{Blocked image.} +handle-as-image - mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} - - # These aliases define combinations of actions - # that are useful for certain types of sites: - # - fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer - shop = -crunch-all-cookies -filter{all-popups} - - - - The first of our specialized sections is concerned with fragile - 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 fragile alias instead of stating the list - of actions explicitly: - - - - -########################################################################## -# 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 - - - - 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: - - - - -# Shopping sites: -# -{ shop } -.quietpc.com -.worldpay.com # for quietpc.com -.jungle.com -.scan.co.uk - - - - The fast-redirects - action, which may have been enabled in match-all.action, - breaks some sites. So disable it for popular sites where we know it misbehaves: - - - - -{ -fast-redirects } -login.yahoo.com -edit.*.yahoo.com -.google.com -.altavista.com/.*(like|url|link):http -.altavista.com/trans.*urltext=http -.nytimes.com - - - - It is important that Privoxy knows which - URLs belong to images, so that if 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 handle-as-image action, - and marking all URLs that end in a known image file extension is a - good start: - - - - -########################################################################## -# Images: -########################################################################## - -# Define which file types will be treated as images, in case they get -# blocked further down this file: -# -{ +handle-as-image } -/.*\.(gif|jpe?g|png|bmp|ico)$ - - - - 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 and - mark them as images in one go, with the help of our - +block-as-image alias defined above. (We could of - course just as well use +block - +handle-as-image here.) - Remember that the type of the replacement image is chosen by the - set-image-blocker - action. Since all URLs have matched the default section with its - +set-image-blocker{pattern} - action before, it still applies and needn't be repeated: - - - - -# 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 - - - - One of the most important jobs of Privoxy - is to block banners. Many of these can be blocked - by the filter{banners-by-size} - 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 - block action to them. - - - 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: - - - - -########################################################################## -# Block these fine banners: -########################################################################## -{ +block{Banner ads.} } - -# 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 - - - - It's quite remarkable how many advertisers actually call their banner - servers ads.company.com, or call the directory - in which the banners are stored simply banners. So the above - generic patterns are surprisingly effective. - - - But being very generic, they necessarily also catch URLs that we don't want - to block. The pattern .*ads. e.g. catches - nasty-ads.nasty-corp.com as intended, - but also downloads.sourcefroge.net or - adsl.some-provider.net. So here come some - well-known exceptions to the +block - section above. - - - Note that these are exceptions to exceptions from the default! Consider the URL - downloads.sourcefroge.net: Initially, all actions are deactivated, - so it wouldn't get blocked. Then comes the defaults section, which matches the - URL, but just deactivates the block - action once again. Then it matches .*ads., an exception to the - general non-blocking policy, and suddenly - +block applies. And now, it'll match - .*loads., where -block - applies, so (unless it matches again further down) it ends up - with no block action applying. - - - - -########################################################################## -# Save some innocent victims of the above generic block patterns: -########################################################################## - -# By domain: -# -{ -block } -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 - - - - Filtering source code can have nasty side effects, - so make an exception for our friends at sourceforge.net, - and all paths with cvs in them. Note that - -filter - disables all filters in one fell swoop! - - - - -# Don't filter code! -# -{ -filter } -/(.*/)?cvs -bugzilla. -developer. -wiki. -.sourceforge.net - - - - The actual default.action is of course much more - comprehensive, but we hope this example made clear how it works. - - - - -user.action - - - 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 user.action, which is parsed after all other - actions files and hence has the last word, over-riding any previously - defined actions. user.action is also a - safe place for your personal settings, since - default.action is actively maintained by the - Privoxy developers and you'll probably want - to install updated versions from time to time. - - - - So let's look at a few examples of things that one might typically do in - user.action: - - - - - - - -# My user.action file. <fred@example.com> - - - - As aliases are local to the actions - file that they are defined in, you can't use the ones from - default.action, unless you repeat them here: - - - - -# 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 = -filter +-content-type-overwrite{text/plain} +-force-text-mode -hide-content-disposition - - - - - 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 - allow-all-cookies 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. - - - - -{ allow-all-cookies } - sourceforge.net - .yahoo.com - .msdn.microsoft.com - .redhat.com - - - - Your bank is allergic to some filter, but you don't know which, so you disable them all: - - - - -{ -filter } - .your-home-banking-site.com - - - - Some file types you may not want to filter for various reasons: - - - - -# 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/ - - - - Example of a simple block 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 copy image location - and pasted the URL below while removing the leading http://, into a - { +block{} } section. Note that { +handle-as-image - } need not be specified, since all URLs ending in - .gif will be tagged as images by the general rules as set - in default.action anyway: - - - - -{ +block{Nasty ads.} } - www.example.com/nasty-ads/sponsor\.gif - another.example.net/more/junk/here/ - - - - 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 Privoxy to guess - the file type just by looking at the URL. - You can use the +block-as-image 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 broken image icon by the - browser. Use cautiously. - - - - -{ +block-as-image } - .doubleclick.net - .fastclick.net - /Realmedia/ads/ - ar.atwola.com/ - - - - 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 feedback, so - you just used the fragile alias on the site, and - -- whoa! -- it worked. The fragile - aliases disables those actions that are most likely to break a site. Also, - good for testing purposes to see if it is Privoxy - that is causing the problem or not. We later find other regular sites - that misbehave, and add those to our personalized list of troublemakers: - - - - -{ fragile } - .forbes.com - webmail.example.com - .mybank.com - - - - You like the fun text replacements in default.filter, - 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: - - - - -{ +filter{fun} } - / # For ALL sites! - - - - Note that the above is not really a good idea: There are exceptions - to the filters in default.action for things that - really shouldn't be filtered, like code on CVS->Web interfaces. Since - user.action has the last word, these exceptions - won't be valid for the fun filtering specified here. - - - - 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: - + + + +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking). + + + + +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap. + + + + +filter{jumping-windows} # Prevent windows from resizing and moving themselves. + + + + +filter{frameset-borders} # Give frames a border and make them resizable. + + + + +filter{iframes} # Removes all detected iframes. Should only be enabled for individual sites. + + + + +filter{demoronizer} # Fix MS's non-standard use of standard charsets. + + + + +filter{shockwave-flash} # Kill embedded Shockwave Flash objects. + + + + +filter{quicktime-kioskmode} # Make Quicktime movies saveable. + + + + +filter{fun} # Text replacements for subversive browsing fun! + + + + +filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably. + + + + +filter{ie-exploits} # Disable some known Internet Explorer bug exploits. + + + + +filter{site-specifics} # Cure for site-specific problems. Don't apply generally! + + + + +filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags. + + + + +filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement. + + + + +filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation. + + + + +filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation. + + + + +filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this. + + + + + - - -{ allow-ads } - .sourceforge.net - .slashdot.org - .osdn.net - - - Note that allow-ads has been aliased to - -block, - -filter{banners-by-size}, and - -filter{banners-by-link} above. - + + +force-text-mode + + + + Typical use: + + Force Privoxy to treat a document as if it was in some kind of text format. + + - - Invoke another alias here to force an over-ride of the MIME type - application/x-sh 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. - + + Effect: + + + Declares a document as text, even if the Content-Type: isn't detected as such. + + + - - -{ handle-as-text } - /.*\.sh$ - + + Type: + + + Boolean. + + - - user.action is generally the best place to define - exceptions and additions to the default policies of - default.action. Some actions are safe to have their - default policies set here though. So let's set a default policy to have a - blank image as opposed to the checkerboard pattern for - ALL sites. / of course matches all URL - paths and patterns: - + + Parameter: + + + N/A + + + - - -{ +set-image-blocker{blank} } -/ # ALL sites - + + Notes: + + + As explained above, + Privoxy tries to only filter files that are + in some kind of text format. The same restrictions apply to + content-type-overwrite. + force-text-mode declares a document as text, + without looking at the Content-Type: first. + + + + Think twice before activating this action. Filtering binary data + with regular expressions can cause file damage. + + + + + + Example usage: + + + ++force-text-mode + + + + + - - - - - - - - - - - -Filter Files - - On-the-fly text substitutions need - to be defined in a filter file. Once defined, they - can then be invoked as an action. - - - &my-app; supports three different filter actions: - filter to - rewrite the content that is send to the client, - client-header-filter - to rewrite headers that are send by the client, and - server-header-filter - to rewrite headers that are send by the server. - + + +forward-override + + + + Typical use: + + Change the forwarding settings based on User-Agent or request origin + + - - &my-app; also supports two tagger actions: - client-header-tagger - and - server-header-tagger. - 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 tag-patterns. - + + Effect: + + + Overrules the forward directives in the configuration file. + + + + + Type: + + + Parameterized. + + - - Multiple filter files can be defined through the filterfile config directive. The filters - as supplied by the developers are located in - default.filter. It is recommended that any locally - defined or modified filters go in a separately defined file such as - user.filter. - + + Parameter: + + + + forward . to use a direct connection without any additional proxies. + + + + forward 127.0.0.1:8123 to use the HTTP proxy listening at 127.0.0.1 port 8123. + + + + + forward-socks4a 127.0.0.1:9050 . to use the socks4a proxy listening at + 127.0.0.1 port 9050. Replace forward-socks4a with forward-socks4 + to use a socks4 connection (with local DNS resolution) instead, use forward-socks5 + for socks5 connections (with remote DNS resolution). + + + + + forward-socks4a 127.0.0.1:9050 proxy.example.org:8000 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 forward-socks4a with forward-socks4 to use a socks4 connection + (with local DNS resolution) instead, use forward-socks5 + for socks5 connections (with remote DNS resolution). + + + + + forward-webserver 127.0.0.1:80 to use the HTTP + server listening at 127.0.0.1 port 80 without adjusting the + request headers. + + + This makes it more convenient to use Privoxy to make + existing websites available as onion services as well. + + + 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. + + + 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. + + + 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. + + + + + - - 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. - + + Notes: + + + This action takes parameters similar to the + forward 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. + + + + Please read the description for the forward directives before + using this action. Forwarding to the wrong people will reduce your privacy and increase the + chances of man-in-the-middle attacks. + + + 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. + + + Use the show-url-info CGI page + to verify that your forward settings do what you thought the do. + + + + - - Enabled content filters are applied to any content whose - Content Type header is recognised as a sign - of text-based content, with the exception of text/plain. - Use the force-text-mode action - to also filter other content. - + + Example usage: + + + +# Use an ssh tunnel for requests previously tagged as +# User-Agent: fetch libfetch/2.0 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$ + + + + + + - - Substitutions are made at the source level, so if you want to roll - your own filters, you should first be familiar with HTML syntax, - and, of course, regular expressions. - - - Just like the actions files, the - filter file is organized in sections, which are called filters - here. Each filter consists of a heading line, that starts with one of the - keywords FILTER:, - CLIENT-HEADER-FILTER: or SERVER-HEADER-FILTER: - followed by the filter's name, and a short (one line) - description of what it does. Below that line - come the jobs, i.e. lines that define the actual - text substitutions. By convention, the name of a filter - should describe what the filter eliminates. The - comment is used in the web-based - user interface. - + + +handle-as-empty-document + + + + Typical use: + + Mark URLs that should be replaced by empty documents if they get blocked + + - - Once a filter called name has been defined - in the filter file, it can be invoked by using an action of the form - +filter{name} - in any actions file. - + + Effect: + + + This action alone doesn't do anything noticeable. It just marks URLs. + If the block action also applies, + the presence or absence of this mark decides whether an HTML BLOCKED + page, or an empty document will be sent to the client as a substitute for the blocked content. + The empty document isn't literally empty, but actually contains a single space. + + + - - 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 foo could look - like this: - + + Type: + + + Boolean. + + - - FILTER: foo Replace all "foo" with "bar" - + + Parameter: + + + N/A + + + - - 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 Perl's - s/// 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 U is supported, - which turns the default to ungreedy matching. - + + Notes: + + + Some browsers complain about syntax errors if JavaScript documents + are blocked with Privoxy's + 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. + + + The content type for the empty document can be specified with + content-type-overwrite{}, + but usually this isn't necessary. + + + - - If you are new to - Regular - Expressions, you might want to take a look at - the Appendix on regular expressions, and - see the Perl - manual for - the - s/// operator's syntax and Perl-style regular - expressions in general. - The below examples might also help to get you started. - + + Example usage: + + + # 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$ + + + + + + - + + +handle-as-image -Filter File Tutorial - - Now, let's complete our foo content filter. We have already defined - the heading, but the jobs are still missing. Since all it does is to replace - foo with bar, there is only one (trivial) job - needed: - + + + Typical use: + + Mark URLs as belonging to images (so they'll be replaced by images if they do get blocked, rather than HTML pages) + + - - s/foo/bar/ - + + Effect: + + + This action alone doesn't do anything noticeable. It just marks URLs as images. + If the block action also applies, + the presence or absence of this mark decides whether an HTML blocked + page, or a replacement image (as determined by the set-image-blocker action) will be sent to the + client as a substitute for the blocked content. + + + - - But wait! Didn't the comment say that all occurrences - of foo should be replaced? Our current job will only take - care of the first foo on each page. For global substitution, - we'll need to add the g option: - + + Type: + + + Boolean. + + - - s/foo/bar/g - + + Parameter: + + + N/A + + + - - Our complete filter now looks like this: - - - FILTER: foo Replace all "foo" with "bar" -s/foo/bar/g - + + Notes: + + + The below generic example section is actually part of default.action. + It marks all URLs with well-known image file name extensions as images and should + be left intact. + + + Users will probably only want to use the handle-as-image action in conjunction with + block, to block sources of banners, whose URLs don't + reflect the file type, like in the second example section. + + + 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 handle-as-image in this situation will not replace the + ad frame with an image, but lead to error messages. + + + - - 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: - + + Example usage (sections): + + + # 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 + + + + + + - - -FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse -# 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 - + + +hide-accept-language + + + + Typical use: + + Pretend to use different language settings. + + - - Following the header line and a comment, you see the job. Note that it uses - | as the delimiter instead of /, because - the pattern contains a forward slash, which would otherwise have to be escaped - by a backslash (\). - + + Effect: + + + Deletes or replaces the Accept-Language: HTTP header in client requests. + + + - - Now, let's examine the pattern: it starts with the text <script.* - enclosed in parentheses. Since the dot matches any character, and * - means: Match an arbitrary number of the element left of myself, this - matches <script, followed by any text, i.e. - it matches the whole page, from the start of the first <script> tag. - + + Type: + + + Parameterized. + + - - That's more than we want, but the pattern continues: document\.referrer - matches only the exact string document.referrer. The dot needed to - be escaped, 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 document.referrer, if both are present - in the page (and appear in that order). - + + Parameter: + + + Keyword: block, or any user defined value. + + + - - But there's still more pattern to go. The next element, again enclosed in parentheses, - is .*</script>. You already know what .* - 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 - document.referrer appears somewhere in between. - + + Notes: + + + Faking the browser's language settings can be useful to make a + foreign User-Agent set with + hide-user-agent + more believable. + + + However some sites with content in different languages check the + Accept-Language: to decide which one to take by default. + Sometimes it isn't possible to later switch to another language without + changing the Accept-Language: header first. + + + Therefore it's a good idea to either only change the + Accept-Language: header to languages you understand, + or to languages that aren't wide spread. + + + Before setting the Accept-Language: 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. + + + - - 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 $1, $2, ... in - the substitute. The U option switches to ungreedy matching, which means - that the first .* in the pattern will only eat up all - text in between <script and the first occurrence - of document.referrer, and that the second .* will - only span the text up to the first </script> - tag. Furthermore, the s option says that the match may span - multiple lines in the page, and the g option again means that the - substitution is global. - + + Example usage (section): + + + # 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} \ +} +/ + + + + + - - So, to summarize, the pattern means: Match all scripts that contain the text - document.referrer. Remember the parts of the script from - (and including) the start tag up to (and excluding) the string - document.referrer as $1, and the part following - that string, up to and including the closing tag, as $2. - - - Now the pattern is deciphered, but wasn't this about substituting things? So - lets look at the substitute: $1"Not Your Business!"$2 is - easy to read: The text remembered as $1, followed by - "Not Your Business!" (including - the quotation marks!), followed by the text remembered as $2. - This produces an exact copy of the original string, with the middle part - (the document.referrer) replaced by "Not Your - Business!". - + + +hide-content-disposition + + + + Typical use: + + Prevent download menus for content you prefer to view inside the browser. + + - - The whole job now reads: Replace document.referrer by - "Not Your Business!" 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. - + + Effect: + + + Deletes or replaces the Content-Disposition: HTTP header set by some servers. + + + + + + Type: + + + Parameterized. + + - - We'll show you two other jobs from the JavaScript taming department, but - this time only point out the constructs of special interest: - + + Parameter: + + + Keyword: block, or any user defined value. + + + - - -# The status bar is for displaying link targets, not pointless blahblah -# -s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig - + + Notes: + + + Some servers set the Content-Disposition: HTTP header for + documents they assume you want to save locally before viewing them. + The Content-Disposition: header contains the file name + the browser is supposed to use by default. + + + In most browsers that understand this header, it makes it impossible to + just view the document, without downloading it first, + even if it's just a simple text file or an image. + + + Removing the Content-Disposition: header helps + to prevent this annoyance, but some browsers additionally check the + Content-Type: 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. + + + 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. + + + This action will probably be removed in the future, + use server-header filters instead. + + + - - \s stands for whitespace characters (space, tab, newline, - carriage return, form feed), so that \s* means: zero - or more whitespace. The ? in .*? - makes this matching of arbitrary text ungreedy. (Note that the U - option is not set). The ['"] construct means: a single - or a double quote. Finally, \1 is - a back-reference to the first parenthesis just like $1 above, - with the difference that in the pattern, a backslash indicates - a back-reference, whereas in the substitute, it's the dollar. - + + Example usage: + + + # Disarm the download link in Sourceforge's patch tracker +{ -filter \ + +content-type-overwrite{text/plain}\ + +hide-content-disposition{block} } + .sourceforge.net/tracker/download\.php + + + + + - - So what does this job do? It replaces assignments of single- or double-quoted - strings to the window.status 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. - - - -# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html -# -s/(<body [^>]*)onunload(.*>)/$1never$2/iU - + + +hide-if-modified-since + + + + Typical use: + + Prevent yet another way to track the user's steps between sessions. + + - - Including the - OnUnload - event binding in the HTML DOM was a CRIME. - When I close a browser window, I want it to close and die. Basta. - This job replaces the onunload attribute in - <body> tags with the dummy word never. - Note that the i 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 [^>]* - instead of .* to prevent the match from exceeding the - <body> tag if it doesn't contain OnUnload, but the page's - content does. - + + Effect: + + + Deletes the If-Modified-Since: HTTP client header or modifies its value. + + + - - The last example is from the fun department: - + + Type: + + + Parameterized. + + - - -FILTER: fun Fun text replacements + + Parameter: + + + Keyword: block, or a user defined value that specifies a range of hours. + + + -# Spice the daily news: -# -s/microsoft(?!\.com)/MicroSuck/ig - + + Notes: + + + Removing this header is useful for filter testing, where you want to force a real + reload instead of getting status code 304, which would cause the + browser to use a cached copy of the page. + + + Instead of removing the header, hide-if-modified-since 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 + Privoxy does the rest. A negative value means + subtracting, a positive value adding. + + + Randomizing the value of the If-Modified-Since: 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. + + + It is a good idea to only use a small negative value and let + overwrite-last-modified + handle the greater changes. + + + It is also recommended to use this action together with + crunch-if-none-match, + otherwise it's more or less pointless. + + + - - Note the (?!\.com) part (a so-called negative lookahead) - in the job's pattern, which means: Don't match, if the string - .com appears directly following microsoft - in the page. This prevents links to microsoft.com from being trashed, while - still replacing the word everywhere else. - + + Example usage (section): + + + # 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} +/ + + + + + - - -# 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 - - - The x option in this job turns on extended syntax, and allows for - e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting. - + + +hide-from-header - - You get the idea? - - + + + Typical use: + + Keep your (old and ill) browser from telling web servers your email address + + - + + Effect: + + + Deletes any existing From: HTTP header, or replaces it with the + specified string. + + + -The Pre-defined Filters + + Type: + + + Parameterized. + + - + + Example usage: + + + +hide-from-header{block} or + +hide-from-header{spam-me-senseless@sittingduck.example.com} + + + + + - -The distribution default.filter file contains a selection of -pre-defined filters for your convenience: - + + +hide-referrer + - js-annoyances + Typical use: + + Conceal which link you followed to get to a particular site + + + + + Effect: - The purpose of this filter is to get rid of particularly annoying JavaScript abuse. - To that end, it + Deletes the Referer: (sic) HTTP header from the client request, + or replaces it with a forged one. + + + + + + Type: + + + Parameterized. + + + + + Parameter: + - - replaces JavaScript references to the browser's referrer information - with the string "Not Your Business!". This compliments the hide-referrer action on the content level. - + conditional-block to delete the header completely if the host has changed. - - removes the bindings to the DOM's - unload - event which we feel has no right to exist and is responsible for most exit consoles, i.e. - nasty windows that pop up when you close another one. - + conditional-forge to forge the header if the host has changed. - - 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. - + block to delete the header unconditionally. + + + forge to pretend to be coming from the homepage of the server we are talking to. + + + Any other string to set a user defined referrer. - - - Use with caution. This is an aggressive filter, and can break sites that - rely heavily on JavaScript. - - js-events + Notes: - 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! + conditional-block 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. - We strongly discourage 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). + Leaving the referrer unmodified for requests on the same host + allows the server owner to see the visitor's click path, + 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. - - - - - html-annoyances - - This filter will undo many common instances of HTML based abuse. + 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. - The BLINK and MARQUEE 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. + Both conditional-block and forge + 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. + + + hide-referer is an alternate spelling of + hide-referrer and the two can be can be freely + substituted with each other. (referrer is the + correct English spelling, however the HTTP specification has a bug - it + requires it to be spelled as referer.) - content-cookies + Example usage: - Most cookies are set in the HTTP dialog, where they can be intercepted - by the - crunch-incoming-cookies - and crunch-outgoing-cookies - actions. But web sites increasingly make use of HTML meta tags and JavaScript - to sneak cookies to the browser on the content level. + +hide-referrer{forge} or + +hide-referrer{http://www.yahoo.com/} + + + + + + + + +hide-user-agent + + + + Typical use: + + Try to conceal your type of browser and client operating system + + + + + Effect: + - 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. + Replaces the value of the User-Agent: HTTP header + in client requests with the specified value. - refresh tags + Type: + + + Parameterized. + + + + + Parameter: - 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. + Any user-defined string. - unsolicited-popups + Notes: + + + 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 NOT the right thing to do: good web sites + work browser-independently). + + - This filter attempts to prevent only unsolicited 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. + Using this action in multi-user setups or wherever different types of + browsers will access the same Privoxy is + not recommended. 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). - Technical note: The filter works by redefining the window.open JavaScript - function to a dummy function, PrivoxyWindowOpen(), - during the loading and rendering phase of each HTML page access, and - restoring the function afterward. + More information on known user-agent strings can be found at + http://www.user-agents.org/ + and + http://en.wikipedia.org/wiki/User_agent. + + + + + Example usage: + - 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. + +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)} + + + + + + +limit-connect + + + + Typical use: + + Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted sites + + - all-popups + Effect: - Attempt to prevent all 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. + Specifies to which ports HTTP CONNECT requests are allowable. - img-reorder + Type: + - - This is a helper filter that has no value if used alone. It makes the - banners-by-size and banners-by-link - (see below) filters more effective and should be enabled together with them. - + Parameterized. - banners-by-size + Parameter: - 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. + A comma-separated list of ports or port ranges (the latter using dashes, with the minimum + defaulting to 0 and the maximum to 65K). + + + + + Notes: + - 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 limit-connect action applies, + Privoxy allows HTTP CONNECT requests to all + ports. Use limit-connect if fine-grained control + is desired for some or all destinations. - Recommended only for those who require extreme ad blocking. The default - block rules should catch 95+% of all ads without this filter enabled. - + The CONNECT methods exists in HTTP to allow access to secure websites + (https:// 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. + + + Privoxy 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. + - banners-by-link + Example usages: - - 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. + + + + + +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 + + + + + + +limit-cookie-lifetime + - webbugs + Typical use: - - 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. - - - This filter removes the HTML code that loads such webbugs. - + Limit the lifetime of HTTP cookies to a couple of minutes or hours. - tiny-textforms + Effect: - 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. - - - 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. - jumping-windows + Type: + - - 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. - + Parameterized. - frameset-borders + Parameter: - 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. - - - This filter removes the related HTML code. It should only be applied to sites - which need it. + The lifetime limit in minutes, or 0. - demoronizer + Notes: - 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. - 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. - + Cookies with a lifetime below the limit are not modified. + The lifetime of session cookies is set to the specified limit. + + + The effect of this action depends on the server. + + + 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. + + + 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. + + + If the parameter is 0, this action behaves like + session-cookies-only. - shockwave-flash + Example usages: - - 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. - - + + +limit-cookie-lifetime{60} + + + + + + +prevent-compression + - quicktime-kioskmode + Typical use: - 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 filters. - fun + Effect: - 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. - crude-parental + Type: + + + Boolean. + + + + + Parameter: - A demonstration-only filter that shows how Privoxy - can be used to delete web content on a keyword basis. + N/A - ie-exploits + Notes: - An experimental collection of text replacements to disable malicious HTML and JavaScript - code that exploits known security holes in Internet Explorer. + More and more websites send their content compressed by default, which + is generally a good idea and saves bandwidth. But the filter and + deanimate-gifs + actions need access to the uncompressed data. - Presently, it only protects against Nimda and a cross-site scripting bug, and - would need active maintenance to provide more substantial protection. + 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. + + + 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. + + + 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. + + + 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 + prevent-compression per default, you might want to add + exceptions for those sites. See the example for how to do that. - site-specifics + Example usage (sections): - Some web sites have very specific problems, the cure for which doesn't apply - anywhere else, or could even cause damage on other sites. - - - 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 - default.action file does. Users shouldn't need to change - anything regarding this filter. + +# 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/ + + + + + + +overwrite-last-modified + + + + Typical use: + + Prevent yet another way to track the user's steps between sessions. + + + - google + Effect: - A CSS based block for Google text ads. Also removes a width limitation - and the toolbar advertisement. + Deletes the Last-Modified: HTTP server header or modifies its value. - - yahoo + + Type: + - - Another CSS based block, this time for Yahoo text ads. And removes - a width limitation as well. - + Parameterized. - - msn + + Parameter: - Another CSS based block, this time for MSN text ads. And removes - tracking URLs, as well as a width limitation. + One of the keywords: block, reset-to-request-time + and randomize - blogspot + Notes: - Cleans up some Blogspot blogs. Read the fine print before using this one! + Removing the Last-Modified: header is useful for filter + testing, where you want to force a real reload instead of getting status + code 304, which would cause the browser to reuse the old + version of the page. - This filter also intentionally removes some navigation stuff and sets the - page width to 100%. As a result, some rounded corners 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. + The randomize option overwrites the value of the + Last-Modified: 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 Last-Modified: + header to track visits without using cookies. Randomize + makes it impossible and the browser can still revalidate cached documents. + + + reset-to-request-time overwrites the value of the + Last-Modified: header with the current time. You could use + this option together with + hide-if-modified-since + to further customize your random range. + + + The preferred parameter here is randomize. It is safe + to use, as long as the time settings are more or less correct. + If the server sets the Last-Modified: 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 + hided-if-modified-since, + just to be sure. + + + It is also recommended to use this action together with + crunch-if-none-match. - - xml-to-html + + Example usage: - - Server-header filter to change the Content-Type from xml to html. + + # Let the browser revalidate without being tracked across sessions +{ +hide-if-modified-since{-60} \ + +overwrite-last-modified{randomize} \ + +crunch-if-none-match} +/ + + - - html-to-xml + + + +redirect + + + + Typical use: - Server-header filter to change the Content-Type from html to xml. + Redirect requests to other sites. - - no-ping + + Effect: - Removes the non-standard ping attribute from - anchor and area HTML tags. + Convinces the browser that the requested document has been moved + to another location and the browser should get it from there. - - hide-tor-exit-notation + + Type: + + + Parameterized + + + + + Parameter: - Client-header filter to remove the Tor exit node notation - found in Host and Referer headers. - - - If &my-app; and Tor are chained and &my-app; - is configured to use socks4a, one can use http://www.example.org.foobar.exit/ - to access the host www.example.org through the - Tor exit node foobar. - - - As the HTTP client isn't aware of this notation, it treats the - whole string www.example.org.foobar.exit as host and uses it - for the Host and Referer headers. From the - server's point of view the resulting headers are invalid and can cause problems. - - - An invalid Referer header can trigger hot-linking - protections, an invalid Host header will make it impossible for - the server to find the right vhost (several domains hosted on the same IP address). - - - This client-header filter removes the foo.exit 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 Tor exit node based on the IP address - the request is coming from. + An absolute URL or a single pcrs command. - - - - - - - - - - - - - -Privoxy's Template Files - - All Privoxy built-in pages, i.e. error pages such as the - 404 - No Such Domain - error page, the BLOCKED - page - and all pages of its web-based - user interface, are generated from templates. - (Privoxy must be running for the above links to work as - intended.) - - - - These templates are stored in a subdirectory of the configuration - directory called templates. On Unixish platforms, - this is typically - /etc/privoxy/templates/. - - - - The templates are basically normal HTML files, but with place-holders (called symbols - or exports), which Privoxy fills at run time. It - is possible to edit the templates with a normal text editor, should you want - to customize them. (Not recommended for the casual - user). Should you create your own custom templates, you should use - the config setting templdir - to specify an alternate location, so your templates do not get overwritten - during upgrades. - - - Note that just like in configuration files, lines starting - with # are ignored when the templates are filled in. - - - - The place-holders are of the form @name@, 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. - - - - 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 Privoxy - is in an alpha or beta development stage: - - - - -<!-- @if-unstable-start --> - - ... beta warning HTML code goes here ... - -<!-- if-unstable-end@ --> - - - - If the "unstable" symbol is set, everything in between and including - @if-unstable-start and if-unstable-end@ - will disappear, leaving nothing but an empty comment: - - - - <!-- --> - - - - There's also an if-then-else construct and an #include - mechanism, but you'll sure find out if you are inclined to edit the - templates ;-) - - - - All templates refer to a style located at - http://config.privoxy.org/send-stylesheet. - This is, of course, locally served by Privoxy - and the source for it can be found and edited in the - cgi-style.css template. - - - - - - - + + Requests can't be blocked and redirected at the same time, + applying this action together with + block + 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. + + + This action can be combined with + fast-redirects{check-decoded-url} + to redirect to a decoded version of a rewritten URL. + + + 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. + + + In case of problems with your redirects, or simply to watch + them working, enable debug 128. + + + - + + Example usages: + + + # Replace example.com's style sheet with another one +{ +redirect{http://localhost/css-replacements/example.com.css} } + example.com/stylesheet\.css -Contacting the Developers, Bug Reporting and Feature -Requests +# 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{http://www.privoxy.org/user-manual/actions-file.html} } + a - - &contacting; - +# 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 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) - -Privoxy Copyright, License and History +# 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]*/ - - ©right; - +# Redirect remote requests for this manual +# to the local version delivered by Privoxy +{+redirect{s@^http://www@http://config@}} +www.privoxy.org/user-manual/ + + + - -License - - &license; - - - + + + +server-header-filter -History - - &history; - - - -Authors - - &p-authors; - - + + + Typical use: + + + Rewrite or remove single server headers. + + + - + + Effect: + + + All server headers to which this action applies are filtered on-the-fly + through the specified regular expression based substitutions. + + + - + + Type: + + + Multi-value. + + + + Parameter: + + + The name of a server-header filter, as defined in one of the + filter files. + + + - -See Also - - &seealso; - - + + Notes: + + + 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. + + + Server-header filters are executed after the other header actions have finished + and use their output as input. + + + Please refer to the filter file chapter + to learn which server-header filters are available by default, and how to + create your own. + + + + + Example usage (section): + + + +{+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 + + + + - -Appendix + + - -Regular Expressions - - Privoxy uses Perl-style regular - expressions in its actions - files and filter file, - through the PCRE and - - PCRS libraries. - - - - If you are reading this, you probably don't understand what regular - expressions are, or what they can do. So this will be a very brief - introduction only. A full explanation would require a book ;-) - - - - 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 meta-characters have - special meanings and are used to build complex patterns to be matched against. - Perl Compatible Regular Expressions are an especially convenient - dialect of the regular expression language. - - - - To make a simple analogy, we do something similar when we use wild-card - characters when listing files with the dir command in DOS. - *.* matches all filenames. The special - character here is the asterisk which matches any and all characters. We can be - more specific and use ? to match just individual - characters. So dir file?.text would match - file1.txt, file2.txt, etc. We are pattern - matching, using a similar technique to regular expressions! - - - - Regular expressions do essentially the same thing, but are much, much more - powerful. There are many more special characters and ways of - building complex patterns however. Let's look at a few of the common ones, - and then some examples: - - - - - . - Matches any single character, e.g. a, - A, 4, :, or @. - - - - - - ? - The preceding character or expression is matched ZERO or ONE - times. Either/or. - - + +server-header-tagger - - - + - The preceding character or expression is matched ONE or MORE - times. - - + + + Typical use: + + + Enable or disable filters based on the Content-Type header. + + + - - - * - The preceding character or expression is matched ZERO or MORE - times. - - + + Effect: + + + 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. + + + - - - \ - The escape character denotes that - the following character should be taken literally. This is used where one of the - special characters (e.g. .) needs to be taken literally and - not as a special meta-character. Example: example\.com, makes - sure the period is recognized only as a period (and not expanded to its - meta-character meaning of any single character). - - + + Type: + + + Multi-value. + + - - - [ ] - Characters enclosed in brackets will be matched if - any of the enclosed characters are encountered. For instance, [0-9] - matches any numeric digit (zero through nine). As an example, we can combine - this with + to match any digit one of more times: [0-9]+. - - + + Parameter: + + + The name of a server-header tagger, as defined in one of the + filter files. + + + - - - ( ) - parentheses are used to group a sub-expression, - or multiple sub-expressions. - - + + Notes: + + + Server-header taggers are applied to each header on its own, + and as the header isn't modified, each tagger sees + the original. + + + 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 (redirect + and block). + + + Obviously crunching based on tags created by server-header taggers + doesn't prevent the request from showing up in the server's log file. + - - - | - The bar character works like an - or conditional statement. A match is successful if the - sub-expression on either side of | matches. As an example: - /(this|that) example/ uses grouping and the bar character - and would match either this example or that - example, and nothing else. - - + + - - These are just some of the ones you are likely to use when matching URLs with - Privoxy, 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: - + + Example usage (section): + + + +# Tag every request with the content type declared by the server +{+server-header-tagger{content-type}} +/ - - /.*/banners/.* - A simple example - that uses the common combination of . and * 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 - (.*) another literal forward slash, the string - banners, another forward slash, and lastly another - .*. We are building - a directory path here. This will match any file with the path that has a - directory named banners in it. The .* 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: - /eye/hate/spammers/banners/annoy_me_please.gif, or just - /banners/annoying.html, or almost an infinite number of other - possible combinations, just so it has banners in the path - somewhere. - +# 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 +# silly example. +{+external-filter{rotate-image} +force-text-mode} +TAG:^image/ + + + + - - And now something a little more complex: - + + - - /.*/adv((er)?ts?|ertis(ing|ements?))?/ - - We have several literal forward slashes again (/), so we are - building another expression that is a file path statement. We have another - .*, so we are matching against any conceivable sub-path, just so - it matches our expression. The only true literal that must - match our pattern is adv, together with - the forward slashes. What comes after the adv string is the - interesting part. - - - Remember the ? means the preceding expression (either a - literal character or anything grouped with (...) in this case) - can exist or not, since this means either zero or one match. So - ((er)?ts?|ertis(ing|ements?)) is optional, as are the - individual sub-expressions: (er), - (ing|ements?), and the s. The | - means or. We have two of those. For instance, - (ing|ements?), can expand to match either ing - OR ements?. What is being done here, is an - attempt at matching as many variations of advertisement, and - similar, as possible. So this would expand to match just adv, - or advert, or adverts, or - advertising, or advertisement, or - advertisements. You get the idea. But it would not match - advertizements (with a z). We could fix that by - changing our regular expression to: - /.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/, which would then match - either spelling. - + + +session-cookies-only - - /.*/advert[0-9]+\.(gif|jpe?g) - Again - another path statement with forward slashes. Anything in the square brackets - [ ] can be matched. This is using 0-9 as a - shorthand expression to mean any digit one through nine. It is the same as - saying 0123456789. So any digit matches. The + - 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: (gif|jpe?g). - This includes a |, so this needs to match the expression on - either side of that bar character also. A simple gif on one side, and the other - side will in turn match either jpeg or jpg, - since the ? means the letter e 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 advert, then one or more digits, and a . - (which is now a literal, and not a special character, since it is escaped - with \), and lastly either gif, or - jpeg, or jpg. Some possible matches would - include: //advert1.jpg, - /nasty/ads/advert1234.gif, - /banners/from/hell/advert99.jpg. It would not match - advert1.gif (no leading slash), or - /adverts232.jpg (the expression does not include an - s), or /advert1.jsp (jsp is not - in the expression anywhere). - + + + Typical use: + + + Allow only temporary session cookies (for the current + browser session only). + + + - - We are barely scratching the surface of regular expressions here so that you - can understand the default Privoxy - 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 :/ - + + Effect: + + + Deletes the expires field from Set-Cookie: + server headers. Most browsers will not store such cookies permanently and + forget them in between sessions. + + + - - More reading on Perl Compatible Regular expressions: - http://perldoc.perl.org/perlre.html - + + Type: + + + Boolean. + + - - For information on regular expression based substitutions and their applications - in filters, please see the filter file tutorial - in this manual. - - + + Parameter: + + + N/A + + + - + + Notes: + + + This is less strict than crunch-incoming-cookies / + crunch-outgoing-cookies and allows you to browse + websites that insist or rely on setting cookies, without compromising your privacy too badly. + + + Most browsers will not permanently store cookies that have been processed by + session-cookies-only 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. + + + It makes no sense at all to use session-cookies-only + together with crunch-incoming-cookies or + crunch-outgoing-cookies. If you do, cookies + will be plainly killed. + + + Note that it is up to the browser how it handles such cookies without an expires + field. If you use an exotic browser, you might want to try it out to be sure. + + + This setting also has no effect on cookies that may have been stored + previously by the browser before starting Privoxy. + These would have to be removed manually. + + + Privoxy also uses + the content-cookies filter + to block some types of cookies. Content cookies are not effected by + session-cookies-only. + + + + + + Example usage: + + + +session-cookies-only + + + + + - -Privoxy's Internal Pages + +set-image-blocker - - Since Privoxy proxies each requested - web page, it is easy for Privoxy to - trap certain special URLs. In this way, we can talk directly to - Privoxy, and see how it is - configured, see how our rules are being applied, change these - rules and other configuration options, and even turn - Privoxy's filtering off, all with - a web browser. + + + Typical use: + + Choose the replacement for blocked images + + - + + Effect: + + + This action alone doesn't do anything noticeable. If both + block and handle-as-image also + apply, i.e. if the request is to be blocked as an image, + then the parameter of this action decides what will be + sent as a replacement. + + + - - The URLs listed below are the special ones that allow direct access - to Privoxy. Of course, - Privoxy must be running to access these. If - not, you will get a friendly error message. Internet access is not - necessary either. - + + Type: + + + Parameterized. + + - - + + Parameter: + + + + + pattern to send a built-in checkerboard pattern image. The image is visually + decent, scales very well, and makes it obvious where banners were busted. + + + + + blank to send a built-in transparent image. This makes banners disappear + completely, but makes it hard to detect where Privoxy has blocked + images on a given page and complicates troubleshooting if Privoxy + has blocked innocent images, like navigation icons. + + + + + target-url to + send a redirect to target-url. You can redirect + to any image anywhere, even in your local filesystem via file:/// URL. + (But note that not all browsers support redirecting to a local file system). + + + A good application of redirects is to use special Privoxy-built-in + URLs, which send the built-in images, as target-url. + This has the same visual effect as specifying blank or pattern in + the first place, but enables your browser to cache the replacement image, instead of requesting + it over and over again. + + + + + - - - Privoxy main page: - -
+ + Notes: + - http://config.privoxy.org/ + The URLs for the built-in images are http://config.privoxy.org/send-banner?type=type, where type is + either blank or pattern. -
- - There is a shortcut: http://p.p/ (But it - doesn't provide a fall-back to a real page, in case the request is not - sent through Privoxy) - - - - - - Show information about the current configuration, including viewing and - editing of actions files: - -
- http://config.privoxy.org/show-status + There is a third (advanced) type, called auto. It is NOT to be + used in set-image-blocker, but meant for use from filters. + Auto will select the type of image that would have applied to the referring page, had it been an image. -
- + + - - - Show the source code version numbers: - -
+ + Example usage: + - http://config.privoxy.org/show-version + Built-in pattern: -
- - - - - Show the browser's request headers: - -
- http://config.privoxy.org/show-request + +set-image-blocker{pattern} -
- - - - - Show which actions apply to a URL and why: - -
- http://config.privoxy.org/show-url-info + Redirect to the BSD daemon: -
- - - - - Toggle Privoxy on or off. This feature can be turned off/on in the main - config file. When toggled off, Privoxy - continues to run, but only as a pass-through proxy, with no actions taking - place: - -
- http://config.privoxy.org/toggle + +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif} -
- - Short cuts. Turn off, then on: - -
- http://config.privoxy.org/toggle?set=disable + Redirect to the built-in pattern for better caching: -
-
- http://config.privoxy.org/toggle?set=enable + +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern} -
- + + + + + + + + +Summary + + 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 Appendix for a brief example on troubleshooting + actions. + + + + + + +Aliases + + Custom actions, known to Privoxy + as aliases, 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, + =, + { and }, but we strongly + recommend that you only use a to z, + 0 to 9, +, and -. + Alias names are not case sensitive, and are not required to start with a + + or - sign, since they are merely textually + expanded. + + + Aliases can be used throughout the actions file, but they must be + defined in a special section at the top of the file! + 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. + + + 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 + shop, you can later change your policy on shops in + one place, and your changes will take effect everywhere + in the actions file where the shop alias is used. Calling aliases + by their purpose also makes your actions files more readable. + + + Currently, there is one big drawback to using aliases, though: + Privoxy'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. + + + + Now let's define some aliases... + + + + + # 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 = +crunch-incoming-cookies +crunch-outgoing-cookies + -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies + +block-as-image = +block{Blocked image.} +handle-as-image + allow-all-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} - - These may be bookmarked for quick reference. See next. + # These aliases define combinations of actions + # that are useful for certain types of sites: + # + fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -prevent-compression - + shop = -crunch-all-cookies -filter{all-popups} - -Bookmarklets - - Below are some bookmarklets to allow you to easily access a - mini version of some of Privoxy's - 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). + # Short names for other aliases, for really lazy people ;-) + # + c0 = +crunch-all-cookies + c1 = -crunch-all-cookies + - To save them, right-click the link and choose Add to Favorites - (IE) or Add Bookmark (Netscape). You will get a warning that - the bookmark may not be safe - just click OK. Then you can run the - Bookmarklet directly from your favorites/bookmarks. For even faster access, - you can put them on the Links bar (IE) or the Personal - Toolbar (Netscape), and run them with a single click. + ...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 / pattern): - - - - - Privoxy - Enable - - - - - - Privoxy - Disable - - + + # 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 - - - Privoxy - Toggle Privoxy (Toggles between enabled and disabled) - - + # Shopping sites: + # Allow cookies (for setting and retrieving your customer data) + # + {shop} + .quietpc.com + .worldpay.com # for quietpc.com + mybank.example.com - - - Privoxy- View Status - - - - - - Privoxy - Why? - - - + # These shops require pop-ups: + # + {-filter{all-popups} -filter{unsolicited-popups}} + .dabs.com + .overclockers.co.uk - Credit: The site which gave us the general idea for these bookmarklets is - www.bookmarklets.com. They - have more information about bookmarklets. + Aliases like shop and fragile are typically used for + problem sites that require more than one action to be disabled + in order to function properly. - - - - - - + - -Chain of Events + +Actions Files Tutorial - Let's take a quick look at how some of Privoxy's - core features are triggered, and the ensuing sequence of events when a web - page is requested by your browser: + The above chapters have shown which actions files + there are and how they are organized, how actions are specified and applied + to URLs, how patterns work, and how to + define and use aliases. Now, let's look at an + example match-all.action, default.action + and user.action file and see how all these pieces come together: + +match-all.action - - - - First, your web browser requests a web page. The browser knows to send - the request to Privoxy, which will in turn, - relay the request to the remote web server after passing the following - tests: - - - - - Privoxy traps any request for its own internal CGI - pages (e.g http://p.p/) and sends the CGI page back to the browser. - - - - - Next, Privoxy checks to see if the URL - matches any +block patterns. If - so, the URL is then blocked, and the remote web server will not be contacted. - +handle-as-image - and - +handle-as-empty-document - are then checked, and if there is no match, an - HTML BLOCKED 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 - +set-image-blocker - (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere). - - - - - Untrusted URLs are blocked. If URLs are being added to the - trust file, then that is done. - - - - - If the URL pattern matches the +fast-redirects action, - it is then processed. Unwanted parts of the requested URL are stripped. - - - - - Now the rest of the client browser's request headers are processed. If any - of these match any of the relevant actions (e.g. +hide-user-agent, - etc.), headers are suppressed or forged as determined by these actions and - their parameters. - - - - - Now the web server starts sending its response back (i.e. typically a web - page). - - - - - 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 - +crunch-incoming-cookies, - +session-cookies-only, - and +downgrade-http-version - actions. - - - - - If any +filter action - or +deanimate-gifs - 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 - default.filter 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 - Privoxy back to your browser. - - - If neither a +filter action - or +deanimate-gifs - matches, then Privoxy passes the raw data through - to the client browser as it becomes available. - - - - - 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 Privoxy's - 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. - - - - + Remember all actions are disabled when matching starts, + so we have to explicitly enable the ones we want. + - 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 - Privoxy's core features only. + While the match-all.action file only contains a + single section, it is probably the most important one. It has only one + pattern, /, but this pattern + matches all URLs. Therefore, the set of + actions used in this default section will + be applied to all requests as a start. It can be partly or + wholly overridden by other actions files like default.action + and user.action, but it will still be largely responsible + for your overall browsing experience. - - - - - -Troubleshooting: Anatomy of an Action + + Again, at the start of matching, all actions are disabled, so there is + no need to disable any actions here. (Remember: a + + preceding the action name enables the action, a - disables!). + Also note how this long line has been made more readable by splitting it into + multiple lines with line continuation. + - The way Privoxy applies - actions and filters - 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 - see just what Privoxy is - doing. Especially, if something Privoxy 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 - regular expressions whose consequences are not - always so obvious. + +{ \ + +change-x-forwarded-for{block} \ + +hide-from-header{block} \ + +set-image-blocker{pattern} \ +} +/ # Match all URLs + - One quick test to see if Privoxy is causing a problem - or not, is to disable it temporarily. This should be the first troubleshooting - step. See the Bookmarklets 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 config file settings, and may need to be - turned on.) - - - 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. + The default behavior is now set. + + + +default.action - Privoxy also provides the - http://config.privoxy.org/show-url-info - page that can show us very specifically how actions - are being applied to any given URL. This is a big help for troubleshooting. + If you aren't a developer, there's no need for you to edit the + default.action file. It is maintained by + the &my-app; developers and if you disagree with some of the + sections, you should overrule them in your user.action. - First, enter one URL (or partial URL) at the prompt, and then - Privoxy will tell us - how the current configuration will handle it. This will not - help with filtering effects (i.e. the +filter 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 View - Page Source option for this. Or right click on the ad, and grab the - URL. + Understanding the default.action file can + help you with your user.action, though. - Let's try an example, google.com, - and look at it one section at a time in a sample configuration (your real - configuration may vary): + The first section in this file is a special section for internal use + that prevents older &my-app; versions from reading the file: - Matches for http://www.google.com: - - In file: default.action [ View ] [ Edit ] +########################################################################## +# Settings -- Don't change! For internal Privoxy use ONLY. +########################################################################## +{{settings}} +for-privoxy-version=3.0.11 + - {+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} -/ + + After that comes the (optional) alias section. We'll use the example + section from the above chapter on aliases, + that also explains why and how aliases are used: + - { -session-cookies-only } - .google.com + + +########################################################################## +# Aliases +########################################################################## +{{alias}} - { -fast-redirects } - .google.com + # These aliases just save typing later: + # (Note that some already use other aliases!) + # + +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies + -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies + +block-as-image = +block{Blocked image.} +handle-as-image + mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} -In file: user.action [ View ] [ Edit ] -(no matches in this file) - + # These aliases define combinations of actions + # that are useful for certain types of sites: + # + fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer + shop = -crunch-all-cookies -filter{all-popups} - This is telling us how we have defined our - actions, and - which ones match for our test case, google.com. - Displayed is all the actions that are available to us. Remember, - the + sign denotes on. - - denotes off. So some are on here, but many - are off. Each example we try may provide a slightly different - end result, depending on our configuration directives. + The first of our specialized sections is concerned with fragile + 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 fragile alias instead of stating the list + of actions explicitly: + - The first listing - is for our default.action 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 actions file, this would be the - section just below the aliases section near the top. This - will apply to all URLs as signified by the single forward slash at the end - of the listing -- / . + +########################################################################## +# 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 - 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 .google.com. The first is negating our previous - cookie setting, which was for +session-cookies-only - (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 - off any +fast-redirects - action, allowing this to take place unmolested. Note that there is a leading - dot here -- .google.com. This will match any hosts and - sub-domains, in the google.com domain also, such as - www.google.com or mail.google.com. But it would not - match www.google.de! So, apparently, we have these two actions - defined as exceptions to the general rules at the top somewhere in the lower - part of our default.action file, and - google.com is referenced somewhere in these latter sections. + 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: - Then, for our user.action 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 default.action. - user.action typically has the last word. This is the - best place to put hard and fast exceptions, + +# Shopping sites: +# +{ shop } +.quietpc.com +.worldpay.com # for quietpc.com +.jungle.com +.scan.co.uk - And finally we pull it all together in the bottom section and summarize how - Privoxy is applying all its actions - to google.com: - + The fast-redirects + action, which may have been enabled in match-all.action, + breaks some sites. So disable it for popular sites where we know it misbehaves: +{ -fast-redirects } +login.yahoo.com +edit.*.yahoo.com +.google.com +.altavista.com/.*(like|url|link):http +.altavista.com/trans.*urltext=http +.nytimes.com + - Final results: - - -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} + + It is important that Privoxy knows which + URLs belong to images, so that if 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 handle-as-image action, + and marking all URLs that end in a known image file extension is a + good start: - Notice the only difference here to the previous listing, is to - fast-redirects and session-cookies-only, - which are activated specifically for this site in our configuration, - and thus show in the Final Results. + +########################################################################## +# Images: +########################################################################## + +# Define which file types will be treated as images, in case they get +# blocked further down this file: +# +{ +handle-as-image } +/.*\.(gif|jpe?g|png|bmp|ico)$ - Now another example, ad.doubleclick.net: + 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 and + mark them as images in one go, with the help of our + +block-as-image alias defined above. (We could of + course just as well use +block + +handle-as-image here.) + Remember that the type of the replacement image is chosen by the + set-image-blocker + action. Since all URLs have matched the default section with its + +set-image-blocker{pattern} + action before, it still applies and needn't be repeated: +# 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 + - { +block{Domains starts with "ad"} } - ad*. + + One of the most important jobs of Privoxy + is to block banners. Many of these can be blocked + by the filter{banners-by-size} + 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 + block action to them. + + + 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: + - { +block{Domain contains "ad"} } - .ad. + + +########################################################################## +# Block these fine banners: +########################################################################## +{ +block{Banner ads.} } - { +block{Doubleclick banner server} +handle-as-image } - .[a-vx-z]*.doubleclick.net - +# 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 - We'll just show the interesting part here - the explicit matches. It is - matched three different times. Two +block{} sections, - and a +block{} +handle-as-image, - which is the expanded form of one of our aliases that had been defined as: - +block-as-image. (Aliases are defined in - the first section of the actions file and typically used to combine more - than one action.) + It's quite remarkable how many advertisers actually call their banner + servers ads.company.com, or call the directory + in which the banners are stored simply banners. So the above + generic patterns are surprisingly effective. + + + But being very generic, they necessarily also catch URLs that we don't want + to block. The pattern .*ads. e.g. catches + nasty-ads.nasty-corp.com as intended, + but also downloads.sourcefroge.net or + adsl.some-provider.net. So here come some + well-known exceptions to the +block + section above. + + + Note that these are exceptions to exceptions from the default! Consider the URL + downloads.sourcefroge.net: Initially, all actions are deactivated, + so it wouldn't get blocked. Then comes the defaults section, which matches the + URL, but just deactivates the block + action once again. Then it matches .*ads., an exception to the + general non-blocking policy, and suddenly + +block applies. And now, it'll match + .*loads., where -block + applies, so (unless it matches again further down) it ends up + with no block action applying. - 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 ad.doubleclick.net - is done here -- as both a +block{} - and an - +handle-as-image. - The custom alias +block-as-image just - simplifies the process and make it more readable. + +########################################################################## +# Save some innocent victims of the above generic block patterns: +########################################################################## + +# By domain: +# +{ -block } +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 - One last example. Let's try http://www.example.net/adsl/HOWTO/. - This one is giving us problems. We are getting a blank page. Hmmm ... + Filtering source code can have nasty side effects, + so make an exception for our friends at sourceforge.net, + and all paths with cvs in them. Note that + -filter + disables all filters in one fell swoop! +# Don't filter code! +# +{ -filter } +/(.*/)?cvs +bugzilla. +developer. +wiki. +.sourceforge.net + - Matches for http://www.example.net/adsl/HOWTO/: + + The actual default.action is of course much more + comprehensive, but we hope this example made clear how it works. + - In file: default.action [ View ] [ Edit ] + - {-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} } - / +user.action - { +block{Path contains "ads".} +handle-as-image } - /ads - + + 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 user.action, which is parsed after all other + actions files and hence has the last word, over-riding any previously + defined actions. user.action is also a + safe place for your personal settings, since + default.action is actively maintained by the + Privoxy developers and you'll probably want + to install updated versions from time to time. - Ooops, the /adsl/ is matching /ads 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 - user.action file) that explicitly - un blocks ( - {-block}) paths with - adsl 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 + user.action: + + + +# My user.action file. <fred@example.com> + - { -block } - /adsl - + + As aliases are local to the actions + file that they are defined in, you can't use the ones from + default.action, unless you repeat them here: - 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 Shift+Reload. + +# 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 = -filter +-content-type-overwrite{text/plain} +-force-text-mode -hide-content-disposition + - 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 + allow-all-cookies 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. - - { +block{Path starts with "ads".} +handle-as-image } - /ads - +{ allow-all-cookies } + sourceforge.net + .yahoo.com + .msdn.microsoft.com + .redhat.com - 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 default.action 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 - +filter actions. - These tend to be harder to troubleshoot. - Try adding the URL for the site to one of aliases that turn off - +filter: + Your bank is allergic to some filter, but you don't know which, so you disable them all: - - { shop } - .quietpc.com - .worldpay.com # for quietpc.com - .jungle.com - .scan.co.uk - .forbes.com - +{ -filter } + .your-home-banking-site.com - { shop } is an alias that expands to - { -filter -session-cookies-only }. - Or you could do your own exception to negate filtering: - + Some file types you may not want to filter for various reasons: +# 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 - +# 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/ - This would turn off all filtering for these sites. This is best - put in user.action, 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 block 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 copy image location + and pasted the URL below while removing the leading http://, into a + { +block{} } section. Note that { +handle-as-image + } need not be specified, since all URLs ending in + .gif will be tagged as images by the general rules as set + in default.action anyway: - Images that are inexplicably being blocked, may well be hitting the -+filter{banners-by-size} - rule, which assumes - that images of certain sizes are ad banners (works well - most of the time since these tend to be standardized). + +{ +block{Nasty ads.} } + www.example.com/nasty-ads/sponsor\.gif + another.example.net/more/junk/here/ - { fragile } 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 Privoxy to guess + the file type just by looking at the URL. + You can use the +block-as-image 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 broken image icon by the + browser. Use cautiously. + - - { fragile } - # Handle with care: easy to break - mail.google. - mybank.example.com +{ +block-as-image } + .doubleclick.net + .fastclick.net + /Realmedia/ads/ + ar.atwola.com/ - - Remember to flush caches! Note that the - mail.google reference lacks the TLD portion (e.g. - .com). This will effectively match any TLD with - google in it, such as mail.google.de., - 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 feedback, so + you just used the fragile alias on the site, and + -- whoa! -- it worked. The fragile + aliases disables those actions that are most likely to break a site. Also, + good for testing purposes to see if it is Privoxy + that is causing the problem or not. We later find other regular sites + that misbehave, and add those to our personalized list of troublemakers: + - 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. + +{ fragile } + .forbes.com + webmail.example.com + .mybank.com - - - - - - Revision 2.90 2008/09/26 16:53:09 fabiankeil - Update "What's new" section. + - Revision 2.89 2008/09/21 15:38:56 fabiankeil - Fix Portage tree sync instructions in Gentoo section. - Anonymously reported at ijbswa-developers@. + - Revision 2.88 2008/09/21 14:42:52 fabiankeil - Add documentation for change-x-forwarded-for{}, - remove documentation for hide-forwarded-for-headers. + - Revision 2.87 2008/08/30 15:37:35 fabiankeil - Update entities. + +Filter Files - Revision 2.86 2008/08/16 10:12:23 fabiankeil - Merge two sentences and move the URL to the end of the item. + + On-the-fly text substitutions need + to be defined in a filter file. Once defined, they + can then be invoked as an action. + - Revision 2.85 2008/08/16 10:04:59 fabiankeil - Some more syntax fixes. This version actually builds. + + &my-app; supports three different pcrs-based filter actions: + filter to + rewrite the content that is send to the client, + client-header-filter + to rewrite headers that are send by the client, and + server-header-filter + to rewrite headers that are send by the server. + - Revision 2.84 2008/08/16 09:42:45 fabiankeil - Turns out building docs works better if the syntax is valid. + + &my-app; also supports two tagger actions: + client-header-tagger + and + server-header-tagger. + 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 tag-patterns. + - Revision 2.83 2008/08/16 09:32:02 fabiankeil - Mention changes since 3.0.9 beta. + + Finally &my-app; supports the + external-filter action + to enable external filters + written in proper programming languages. + - 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. + + Multiple filter files can be defined through the filterfile config directive. The filters + as supplied by the developers are located in + default.filter. It is recommended that any locally + defined or modified filters go in a separately defined file such as + user.filter. + - Revision 2.80 2008/07/18 16:54:30 fabiankeil - Remove erroneous whitespace in documentation link. - Reported by John Chronister in #2021611. + + 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. + - Revision 2.79 2008/06/27 18:00:53 markm68k - remove outdated startup information for mac os x + + Enabled content filters are applied to any content whose + Content Type header is recognised as a sign + of text-based content, with the exception of text/plain. + Use the force-text-mode action + to also filter other content. + - Revision 2.78 2008/06/21 17:03:03 fabiankeil - Fix typo. + + Substitutions are made at the source level, so if you want to roll + your own filters, you should first be familiar with HTML syntax, + and, of course, regular expressions. + - Revision 2.77 2008/06/14 13:45:22 fabiankeil - Re-add a colon I unintentionally removed a few revisions ago. + + Just like the actions files, the + filter file is organized in sections, which are called filters + here. Each filter consists of a heading line, that starts with one of the + keywords FILTER:, + CLIENT-HEADER-FILTER: or SERVER-HEADER-FILTER: + followed by the filter's name, and a short (one line) + description of what it does. Below that line + come the jobs, i.e. lines that define the actual + text substitutions. By convention, the name of a filter + should describe what the filter eliminates. The + comment is used in the web-based + user interface. + - Revision 2.76 2008/06/14 13:21:28 fabiankeil - Prepare for the upcoming 3.0.9 beta release. + + Once a filter called name has been defined + in the filter file, it can be invoked by using an action of the form + +filter{name} + in any actions file. + - 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. + + 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 foo could look + like this: + - 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. + + FILTER: foo Replace all "foo" with "bar" + - Revision 2.73 2008/05/23 14:43:18 fabiankeil - Remove previously out-commented block that caused syntax problems. + + 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 Perl's + s/// 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. + - Revision 2.72 2008/05/12 10:26:14 fabiankeil - Synchronize content filter descriptions with the ones in default.filter. + + Most notably, the non-standard option letter U is supported, + which turns the default to ungreedy matching (add ? to + quantifiers to turn them greedy again). + - Revision 2.71 2008/04/10 17:37:16 fabiankeil - Actually we use "modern" POSIX 1003.2 regular - expressions in path patterns, not PCRE. + + The non-standard option letter D (dynamic) allows + to use the variables $host, $origin (the IP address the request came from), + $path and $url. They will be replaced with the value they refer to before + the filter is executed. + - Revision 2.70 2008/04/10 15:59:12 fabiankeil - Add another section to the client-header-tagger example that shows - how to actually change the action settings once the tag is created. + + Note that '$' 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 $url. + - Revision 2.69 2008/03/29 12:14:25 fabiankeil - Remove send-wafer and send-vanilla-wafer actions. + + The non-standard option letter T (trivial) prevents + parsing for backreferences in the substitute. Use it if you want to include + text like '$&' in your substitute without quoting. + - Revision 2.68 2008/03/28 15:13:43 fabiankeil - Remove inspect-jpegs action. + + If you are new to + Regular + Expressions, you might want to take a look at + the Appendix on regular expressions, and + see the Perl + manual for + the + s/// operator's syntax and Perl-style regular + expressions in general. + The below examples might also help to get you started. + - 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. + - 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. +Filter File Tutorial + + Now, let's complete our foo content filter. We have already defined + the heading, but the jobs are still missing. Since all it does is to replace + foo with bar, there is only one (trivial) job + needed: + - Revision 2.64 2008/03/01 14:10:28 fabiankeil - Use new block syntax. Still needs some polishing. + + s/foo/bar/ + - Revision 2.63 2008/02/22 05:50:37 markm68k - fix merge problem + + But wait! Didn't the comment say that all occurrences + of foo should be replaced? Our current job will only take + care of the first foo on each page. For global substitution, + we'll need to add the g option: + - Revision 2.62 2008/02/11 11:52:23 hal9 - Fix entity ... s/&/& + + s/foo/bar/g + - Revision 2.61 2008/02/11 03:41:47 markm68k - more updates for mac os x + + Our complete filter now looks like this: + + + FILTER: foo Replace all "foo" with "bar" +s/foo/bar/g + - Revision 2.60 2008/02/11 03:40:25 markm68k - more updates for mac os x + + 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: + - 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/ + + +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 + - 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. + + Following the header line and a comment, you see the job. Note that it uses + | as the delimiter instead of /, because + the pattern contains a forward slash, which would otherwise have to be escaped + by a backslash (\). + - Revision 2.55 2008/01/19 21:26:37 hal9 - Add IE7 to configuration section per Gerry. + + Now, let's examine the pattern: it starts with the text <script.* + enclosed in parentheses. Since the dot matches any character, and * + means: Match an arbitrary number of the element left of myself, this + matches <script, followed by any text, i.e. + it matches the whole page, from the start of the first <script> tag. + - Revision 2.54 2008/01/19 17:52:39 hal9 - Re-commit to fix various minor issues for new release. + + That's more than we want, but the pattern continues: document\.referrer + matches only the exact string document.referrer. The dot needed to + be escaped, 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 document.referrer, if both are present + in the page (and appear in that order). + - Revision 2.53 2008/01/19 15:03:05 hal9 - Doc sources tagged for 3.0.8 release. + + But there's still more pattern to go. The next element, again enclosed in parentheses, + is .*</script>. You already know what .* + 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 + document.referrer appears somewhere in between. + - 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. + + 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 $1, $2, ... in + the substitute. The U option switches to ungreedy matching, which means + that the first .* in the pattern will only eat up all + text in between <script and the first occurrence + of document.referrer, and that the second .* will + only span the text up to the first </script> + tag. Furthermore, the s option says that the match may span + multiple lines in the page, and the g option again means that the + substitution is global. + - Revision 2.51 2007/12/23 16:48:24 fabiankeil - Use more precise example descriptions for the mysterious domain patterns. + + So, to summarize, the pattern means: Match all scripts that contain the text + document.referrer. Remember the parts of the script from + (and including) the start tag up to (and excluding) the string + document.referrer as $1, and the part following + that string, up to and including the closing tag, as $2. + - 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. + + Now the pattern is deciphered, but wasn't this about substituting things? So + lets look at the substitute: $1"Not Your Business!"$2 is + easy to read: The text remembered as $1, followed by + "Not Your Business!" (including + the quotation marks!), followed by the text remembered as $2. + This produces an exact copy of the original string, with the middle part + (the document.referrer) replaced by "Not Your + Business!". + - Revision 2.49 2007/12/06 18:21:55 fabiankeil - Update hide-forwarded-for-headers description. + + The whole job now reads: Replace document.referrer by + "Not Your Business!" 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. + - Revision 2.48 2007/11/24 19:07:17 fabiankeil - - Mention request rewriting. - - Enable the conditional-forge paragraph. - - Minor rewordings. + + We'll show you two other jobs from the JavaScript taming department, but + this time only point out the constructs of special interest: + - Revision 2.47 2007/11/18 14:59:47 fabiankeil - A few "Note to Upgraders" updates. + + +# The status bar is for displaying link targets, not pointless blahblah +# +s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig + - Revision 2.46 2007/11/17 17:24:44 fabiankeil - - Use new action defaults. - - Minor fixes and rewordings. + + \s stands for whitespace characters (space, tab, newline, + carriage return, form feed), so that \s* means: zero + or more whitespace. The ? in .*? + makes this matching of arbitrary text ungreedy. (Note that the U + option is not set). The ['"] construct means: a single + or a double quote. Finally, \1 is + a back-reference to the first parenthesis just like $1 above, + with the difference that in the pattern, a backslash indicates + a back-reference, whereas in the substitute, it's the dollar. + - Revision 2.45 2007/11/16 11:48:46 hal9 - Fix one typo, and add a couple of small refinements. + + So what does this job do? It replaces assignments of single- or double-quoted + strings to the window.status 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. + - Revision 2.44 2007/11/15 03:30:20 hal9 - Results of spell check. + + +# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html +# +s/(<body [^>]*)onunload(.*>)/$1never$2/iU + - Revision 2.43 2007/11/14 18:45:39 fabiankeil - - Mention some more contributors in the "New in this Release" list. - - Minor rewordings. + + Including the + OnUnload + event binding in the HTML DOM was a CRIME. + When I close a browser window, I want it to close and die. Basta. + This job replaces the onunload attribute in + <body> tags with the dummy word never. + Note that the i 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 [^>]* + instead of .* to prevent the match from exceeding the + <body> tag if it doesn't contain OnUnload, but the page's + content does. + - 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. + + The last example is from the fun department: + - 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). + + +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 + - Revision 2.39 2007/11/05 02:34:49 hal9 - Various changes in preparation for the upcoming release. Much yet to be done. + + Note the (?!\.com) part (a so-called negative lookahead) + in the job's pattern, which means: Don't match, if the string + .com appears directly following microsoft + in the page. This prevents links to microsoft.com from being trashed, while + still replacing the word everywhere else. + - Revision 2.38 2007/09/22 16:01:42 fabiankeil - Update embedded show-url-info output. + + +# 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 + - 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. + + The x option in this job turns on extended syntax, and allows for + e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting. + - 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. + + You get the idea? + + - Revision 2.35 2007/08/26 14:59:49 fabiankeil - Minor rewordings and fixes. + - 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. +The Pre-defined Filters - Revision 2.33 2007/07/27 10:57:35 hal9 - Add references for user-agent strings for hide-user-agenet + - 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. + +The distribution default.filter file contains a selection of +pre-defined filters for your convenience: + - 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. + + + js-annoyances + + + The purpose of this filter is to get rid of particularly annoying JavaScript abuse. + To that end, it + + + + replaces JavaScript references to the browser's referrer information + with the string "Not Your Business!". This compliments the hide-referrer action on the content level. + + + + + removes the bindings to the DOM's + unload + event which we feel has no right to exist and is responsible for most exit consoles, i.e. + nasty windows that pop up when you close another one. + + + + + 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. + + + + + + Use with caution. This is an aggressive filter, and can break sites that + rely heavily on JavaScript. + + + - Revision 2.28 2006/12/10 23:42:48 hal9 - Fix various typos reported by Adam P. Thanks. + + js-events + + + 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! + + + We strongly discourage 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). + + + - 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. + + html-annoyances + + + This filter will undo many common instances of HTML based abuse. + + + The BLINK and MARQUEE 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. + + + - Revision 2.26 2006/10/24 11:16:44 hal9 - Add new filters. + + content-cookies + + + Most cookies are set in the HTTP dialog, where they can be intercepted + by the + crunch-incoming-cookies + and crunch-outgoing-cookies + actions. But web sites increasingly make use of HTML meta tags and JavaScript + to sneak cookies to the browser on the content level. + + + 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. + + + - 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. + + refresh-tags + + + 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. + + + - Revision 2.24 2006/10/03 11:13:54 hal9 - More references to the new filters. Include html this time around. + + unsolicited-popups + + + This filter attempts to prevent only unsolicited 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. + + + Technical note: The filter works by redefining the window.open JavaScript + function to a dummy function, PrivoxyWindowOpen(), + during the loading and rendering phase of each HTML page access, and + restoring the function afterward. + + + 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. + + + - Revision 2.23 2006/10/02 22:43:53 hal9 - Contains new filter definitions from Fabian, and few other miscellaneous - touch-ups. + + all-popups + + + Attempt to prevent all 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. + + + - 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. + + img-reorder + + + This is a helper filter that has no value if used alone. It makes the + banners-by-size and banners-by-link + (see below) filters more effective and should be enabled together with them. + + + - Revision 2.21 2006/09/20 03:21:36 david__schmidt - Just the tiniest tweak. Wafer thin! + + banners-by-size + + + 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. + + + 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. + + + Recommended only for those who require extreme ad blocking. The default + block rules should catch 95+% of all ads without this filter enabled. + + + - Revision 2.20 2006/09/10 14:53:54 hal9 - Results of spell check. User manual has some updates to standard.actions file - info. + + banners-by-link + + + 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. + + + - Revision 2.19 2006/09/08 12:19:02 fabiankeil - Adjust hide-if-modified-since example values - to reflect the recent changes. + + webbugs + + + 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. + + + This filter removes the HTML code that loads such webbugs. + + + - 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. + + tiny-textforms + + + 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. + + + It is not recommended to use this filter as a default. + + + - 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. + + jumping-windows + + + 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. + + + - Revision 2.16 2006/09/02 12:49:37 hal9 - Various small updates for new actions, filterfiles, etc. + + frameset-borders + + + 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. + + + This filter removes the related HTML code. It should only be applied to sites + which need it. + + + - 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. + + demoronizer + + + 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 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. + + + + - 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. + + shockwave-flash + + + 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. + + + + + - 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. + + quicktime-kioskmode + + + Change HTML code that embeds Quicktime objects so that kioskmode, which + prevents saving, is disabled. + + + - Revision 2.12 2006/08/14 08:40:39 fabiankeil - Documented new actions that were part of - the "minor Privoxy improvements". + + fun + + + Text replacements for subversive browsing fun. Make fun of your favorite + Monopolist or play buzzword bingo. + + + - 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) + + crude-parental + + + A demonstration-only filter that shows how Privoxy + can be used to delete web content on a keyword basis. + + + - Revision 1.123.2.43 2005/05/23 09:59:10 hal9 - Fix typo 'loose' + + ie-exploits + + + An experimental collection of text replacements to disable malicious HTML and JavaScript + code that exploits known security holes in Internet Explorer. + + + Presently, it only protects against Nimda and a cross-site scripting bug, and + would need active maintenance to provide more substantial protection. + + + - Revision 1.123.2.42 2004/12/04 14:39:57 hal9 - Fix two minor typos per bug SF report. + + site-specifics + + + Some web sites have very specific problems, the cure for which doesn't apply + anywhere else, or could even cause damage on other sites. + + + 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 + default.action file does. Users shouldn't need to change + anything regarding this filter. + + + - Revision 1.123.2.41 2004/03/23 12:58:42 oes - Fixed an inaccuracy + + google + + + A CSS based block for Google text ads. Also removes a width limitation + and the toolbar advertisement. + + + - 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. + + yahoo + + + Another CSS based block, this time for Yahoo text ads. And removes + a width limitation as well. + + + - Revision 1.123.2.39 2004/01/30 22:31:40 oes - Added a hint re bookmarklets to Quickstart section + + msn + + + Another CSS based block, this time for MSN text ads. And removes + tracking URLs, as well as a width limitation. + + + - Revision 1.123.2.38 2004/01/30 16:47:51 oes - Some minor clarifications + + blogspot + + + Cleans up some Blogspot blogs. Read the fine print before using this one! + + + This filter also intentionally removes some navigation stuff and sets the + page width to 100%. As a result, some rounded corners 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. + + + - 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. + + xml-to-html + + + Server-header filter to change the Content-Type from xml to html. + + + - Revision 1.123.2.36 2003/12/10 02:26:26 hal9 - Changed the demoronizer filter description. + + html-to-xml + + + Server-header filter to change the Content-Type from html to xml. + + + - Revision 1.123.2.35 2003/11/06 13:36:37 oes - Updated link to nightly CVS tarball + + no-ping + + + Removes the non-standard ping attribute from + anchor and area HTML tags. + + + - 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. + + hide-tor-exit-notation + + + Client-header filter to remove the Tor exit node notation + found in Host and Referer headers. + + + If &my-app; and Tor are chained and &my-app; + is configured to use socks4a, one can use http://www.example.org.foobar.exit/ + to access the host www.example.org through the + Tor exit node foobar. + + + As the HTTP client isn't aware of this notation, it treats the + whole string www.example.org.foobar.exit as host and uses it + for the Host and Referer headers. From the + server's point of view the resulting headers are invalid and can cause problems. + + + An invalid Referer header can trigger hot-linking + protections, an invalid Host header will make it impossible for + the server to find the right vhost (several domains hosted on the same IP address). + + + This client-header filter removes the foo.exit 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 Tor exit node based on the IP address + the request is coming from. + + + - 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. + + - 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). + - Revision 1.123.2.31 2003/03/26 02:03:43 oes - Updated hard-coded copyright dates + +External filter syntax + + External filters are scripts or programs that can modify the content in + case common filters + aren't powerful enough. + + + External filters can be written in any language the platform &my-app; runs + on supports. + + + They are controlled with the + external-filter action + and have to be defined in the filterfile + first. + + + 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). + + + 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 can be used to get some details about the + client request. + + + &my-app; will temporary store the content to filter in the + temporary-directory. + + + +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]" - + + - Revision 1.123.2.29 2003/03/20 02:45:29 hal9 - More problems with \-\-chroot causing markup problems :( + + + Currently external filters are executed with &my-app;'s privileges! + Only use external filters you understand and trust. + + + + External filters are experimental and the syntax may change in the future. + + - 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). + - Revision 1.123.2.27 2003/03/18 19:37:14 oes - s/Advanced|Radical/Adventuresome/g to avoid complaints re fun filter + - 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. + - Revision 1.123.2.23 2002/10/21 02:32:01 hal9 - Updates to the user.action examples section. A few new ones. + +Privoxy's Template Files + + All Privoxy built-in pages, i.e. error pages such as the + 404 - No Such Domain + error page, the BLOCKED + page + and all pages of its web-based + user interface, are generated from templates. + (Privoxy must be running for the above links to work as + intended.) + - Revision 1.123.2.22 2002/10/12 00:51:53 hal9 - Add demoronizer to filter section. + + These templates are stored in a subdirectory of the configuration + directory called templates. On Unixish platforms, + this is typically + /etc/privoxy/templates/. + - Revision 1.123.2.21 2002/10/10 04:09:35 hal9 - s/Advanced/Radical/ and added very brief note. + + The templates are basically normal HTML files, but with place-holders (called symbols + or exports), which Privoxy fills at run time. It + is possible to edit the templates with a normal text editor, should you want + to customize them. (Not recommended for the casual + user). Should you create your own custom templates, you should use + the config setting templdir + to specify an alternate location, so your templates do not get overwritten + during upgrades. + + + Note that just like in configuration files, lines starting + with # are ignored when the templates are filled in. + - 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. + + The place-holders are of the form @name@, 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. + - Revision 1.123.2.19 2002/09/26 01:25:36 hal9 - More explanation on Privoxy patterns, more on content-cookies and SSL. + + 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 Privoxy + is in an alpha or beta development stage: + - Revision 1.123.2.18 2002/08/22 23:47:58 hal9 - Add 'Documentation' to Privoxy Menu shot in Configuration section to match - CGIs. + + +<!-- @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@ --> + - 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 + + If the "unstable" symbol is set, everything in between and including + @if-unstable-start and if-unstable-end@ + will disappear, leaving nothing but an empty comment: + - Revision 1.123.2.14 2002/08/06 09:16:13 oes - Nits re: actions file download + + <!-- --> + - Revision 1.123.2.13 2002/08/02 18:23:19 g_sauthoff - Just 2 small corrections to the Gentoo sections + + There's also an if-then-else construct and an #include + mechanism, but you'll sure find out if you are inclined to edit the + templates ;-) + - Revision 1.123.2.12 2002/08/02 18:17:21 g_sauthoff - Added 2 Gentoo sections + + All templates refer to a style located at + http://config.privoxy.org/send-stylesheet. + This is, of course, locally served by Privoxy + and the source for it can be found and edited in the + cgi-style.css template. + - 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 + - Revision 1.123.2.10 2002/07/25 21:42:29 hal9 - Add brief notes on not proxying non-HTTP protocols. + - 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. + - Revision 1.123.2.7 2002/06/09 00:29:34 hal9 - Touch ups on filtering, in actions section and Anatomy. +Contacting the Developers, Bug Reporting and Feature +Requests - Revision 1.123.2.6 2002/06/06 23:11:03 hal9 - Fix broken link. Linkchecked all docs. + + &contacting; + - 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. + - Revision 1.123.2.4 2002/05/27 03:28:45 hal9 - Ooops missed something from David. + - 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. + +Privoxy Copyright, License and History - Revision 1.123.2.1 2002/05/26 17:04:25 hal9 - -Spellcheck, very minor edits, and sync across branches + + ©right; + - 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. + + Privoxy is free software; you can + redistribute it and/or modify it under the terms of the + GNU General Public License, version 2, + as published by the Free Software Foundation and included in + the next section. + - Revision 1.122 2002/05/24 13:24:08 oes - Added Bookmarklet for one-click pre-filled access to show-url-info + +License + + + - Revision 1.121 2002/05/23 23:20:17 oes - - Changed more (all?) references to actions to the - style. - - Small fixes in the actions chapter - - Small clarifications in the quickstart to ad blocking - - Removed from 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 + + &history; + + - 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 +Authors + + &p-authors; + + - Revision 1.116 2002/05/17 03:23:46 hal9 - Fixing merge conflict in Quickstart section. + - Revision 1.115 2002/05/16 16:25:00 oes - Extended the Filter File chapter & minor fixes + - 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 + +See Also + + &seealso; + + - 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 + +Appendix - 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 + + +Regular Expressions + + Privoxy uses Perl-style regular + expressions in its actions + files and filter file, + through the PCRE and + + PCRS libraries. + - 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. + + If you are reading this, you probably don't understand what regular + expressions are, or what they can do. So this will be a very brief + introduction only. A full explanation would require a book ;-) + - 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). + + 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 meta-characters have + special meanings and are used to build complex patterns to be matched against. + Perl Compatible Regular Expressions are an especially convenient + dialect of the regular expression language. + - Revision 1.105 2002/05/05 20:26:02 hal9 - Sorting out license vs copyright in these docs. + + To make a simple analogy, we do something similar when we use wild-card + characters when listing files with the dir command in DOS. + *.* matches all filenames. The special + character here is the asterisk which matches any and all characters. We can be + more specific and use ? to match just individual + characters. So dir file?.text would match + file1.txt, file2.txt, etc. We are pattern + matching, using a similar technique to regular expressions! + - Revision 1.104 2002/05/04 08:44:45 swa - bumped version + + Regular expressions do essentially the same thing, but are much, much more + powerful. There are many more special characters and ways of + building complex patterns however. Let's look at a few of the common ones, + and then some examples: + - 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. + + + . - Matches any single character, e.g. a, + A, 4, :, or @. + + - Revision 1.102 2002/05/03 17:46:00 oes - Further proofread & reactivated short build instructions + + + ? - The preceding character or expression is matched ZERO or ONE + times. Either/or. + + - 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. + + + + - The preceding character or expression is matched ONE or MORE + times. + + - Revision 1.100 2002/04/29 03:05:55 hal9 - Add clarification on differences of new actions files. + + + * - The preceding character or expression is matched ZERO or MORE + times. + + - Revision 1.99 2002/04/28 16:59:05 swa - more structure in starting section + + + \ - The escape character denotes that + the following character should be taken literally. This is used where one of the + special characters (e.g. .) needs to be taken literally and + not as a special meta-character. Example: example\.com, makes + sure the period is recognized only as a period (and not expanded to its + meta-character meaning of any single character). + + - 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 :( + + + [ ] - Characters enclosed in brackets will be matched if + any of the enclosed characters are encountered. For instance, [0-9] + matches any numeric digit (zero through nine). As an example, we can combine + this with + to match any digit one of more times: [0-9]+. + + - Revision 1.97 2002/04/27 21:04:42 hal9 - -Rewrite of Actions File example. - -Add section for user-manual directive in config. + + + ( ) - parentheses are used to group a sub-expression, + or multiple sub-expressions. + + - 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). + + + | - The bar character works like an + or conditional statement. A match is successful if the + sub-expression on either side of | matches. As an example: + /(this|that) example/ uses grouping and the bar character + and would match either this example or that + example, and nothing else. + + - 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 + + These are just some of the ones you are likely to use when matching URLs with + Privoxy, 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: + - 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. + + /.*/banners/.* - A simple example + that uses the common combination of . and * 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 + (.*) another literal forward slash, the string + banners, another forward slash, and lastly another + .*. We are building + a directory path here. This will match any file with the path that has a + directory named banners in it. The .* 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: + /eye/hate/spammers/banners/annoy_me_please.gif, or just + /banners/annoying.html, or almost an infinite number of other + possible combinations, just so it has banners in the path + somewhere. + - 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. + + And now something a little more complex: + - Revision 1.91 2002/04/24 02:39:31 hal9 - Add 'Chain of Events' section. + + /.*/adv((er)?ts?|ertis(ing|ements?))?/ - + We have several literal forward slashes again (/), so we are + building another expression that is a file path statement. We have another + .*, so we are matching against any conceivable sub-path, just so + it matches our expression. The only true literal that must + match our pattern is adv, together with + the forward slashes. What comes after the adv string is the + interesting part. + - Revision 1.90 2002/04/23 21:41:25 hal9 - Linuxconf is deprecated on RH, substitute chkconfig. + + Remember the ? means the preceding expression (either a + literal character or anything grouped with (...) in this case) + can exist or not, since this means either zero or one match. So + ((er)?ts?|ertis(ing|ements?)) is optional, as are the + individual sub-expressions: (er), + (ing|ements?), and the s. The | + means or. We have two of those. For instance, + (ing|ements?), can expand to match either ing + OR ements?. What is being done here, is an + attempt at matching as many variations of advertisement, and + similar, as possible. So this would expand to match just adv, + or advert, or adverts, or + advertising, or advertisement, or + advertisements. You get the idea. But it would not match + advertizements (with a z). We could fix that by + changing our regular expression to: + /.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/, which would then match + either spelling. + - Revision 1.89 2002/04/23 21:05:28 oes - Added hint for startup on Red Hat + + /.*/advert[0-9]+\.(gif|jpe?g) - Again + another path statement with forward slashes. Anything in the square brackets + [ ] can be matched. This is using 0-9 as a + shorthand expression to mean any digit one through nine. It is the same as + saying 0123456789. So any digit matches. The + + 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: (gif|jpe?g). + This includes a |, so this needs to match the expression on + either side of that bar character also. A simple gif on one side, and the other + side will in turn match either jpeg or jpg, + since the ? means the letter e 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 advert, then one or more digits, and a . + (which is now a literal, and not a special character, since it is escaped + with \), and lastly either gif, or + jpeg, or jpg. Some possible matches would + include: //advert1.jpg, + /nasty/ads/advert1234.gif, + /banners/from/hell/advert99.jpg. It would not match + advert1.gif (no leading slash), or + /adverts232.jpg (the expression does not include an + s), or /advert1.jsp (jsp is not + in the expression anywhere). + - Revision 1.88 2002/04/23 05:37:54 hal9 - Add AmigaOS install stuff. + + We are barely scratching the surface of regular expressions here so that you + can understand the default Privoxy + 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 :/ + - 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 + + More reading on Perl Compatible Regular expressions: + http://perldoc.perl.org/perlre.html + - Revision 1.86 2002/04/21 01:46:32 hal9 - Re-write actions section. + + For information on regular expression based substitutions and their applications + in filters, please see the filter file tutorial + in this manual. + + - Revision 1.85 2002/04/18 21:23:23 hal9 - Fix ugly typo (mine). + - 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 + + +Privoxy's Internal Pages - Revision 1.82 2002/04/18 12:04:50 oes - Cosmetics + + Since Privoxy proxies each requested + web page, it is easy for Privoxy to + trap certain special URLs. In this way, we can talk directly to + Privoxy, and see how it is + configured, see how our rules are being applied, change these + rules and other configuration options, and even turn + Privoxy's filtering off, all with + a web browser. - Revision 1.81 2002/04/18 11:50:24 oes - Extended Install section - needs fixing by packagers + - Revision 1.80 2002/04/18 10:45:19 oes - Moved text to buildsource.sgml, renamed some filters, details + + The URLs listed below are the special ones that allow direct access + to Privoxy. Of course, + Privoxy must be running to access these. If + not, you will get a friendly error message. Internet access is not + necessary either. + - Revision 1.79 2002/04/18 03:18:06 hal9 - Spellcheck, and minor touchups. + + - Revision 1.78 2002/04/17 18:04:16 oes - Proofreading part 2 + + + Privoxy main page: + +
+ + http://config.privoxy.org/ + +
+ + There is a shortcut: http://p.p/ (But it + doesn't provide a fall-back to a real page, in case the request is not + sent through Privoxy) + + - Revision 1.77 2002/04/17 13:51:23 oes - Proofreading, part one + + + Show information about the current configuration, including viewing and + editing of actions files: + +
+ + http://config.privoxy.org/show-status + +
+ - 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. + + + Show the source code version numbers: + +
+ + http://config.privoxy.org/show-version + +
+ - Revision 1.75 2002/04/12 02:08:48 david__schmidt - Remove OS/2 building info... it is already in the developer-manual + + + Show the browser's request headers: + +
+ + http://config.privoxy.org/show-request + +
+ - Revision 1.74 2002/04/11 00:54:38 hal9 - Add small section on submitting actions. + + + Show which actions apply to a URL and why: + +
+ + http://config.privoxy.org/show-url-info + +
+ - Revision 1.73 2002/04/10 18:45:15 swa - generated + + + Toggle Privoxy on or off. This feature can be turned off/on in the main + config file. When toggled off, Privoxy + continues to run, but only as a pass-through proxy, with no actions taking + place: + +
+ + http://config.privoxy.org/toggle + +
+ + Short cuts. Turn off, then on: + +
+ + http://config.privoxy.org/toggle?set=disable + +
+
+ + http://config.privoxy.org/toggle?set=enable + +
+ - Revision 1.72 2002/04/10 04:06:19 hal9 - Added actions feedback to Bookmarklets section + + - Revision 1.71 2002/04/08 22:59:26 hal9 - Version update. Spell chkconfig correctly :) + - 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. + + +Chain of Events + + Let's take a quick look at how some of Privoxy's + core features are triggered, and the ensuing sequence of events when a web + page is requested by your browser: + - Revision 1.68 2002/04/04 18:46:47 swa - consistent look. reuse of copyright, history et. al. + + + + + First, your web browser requests a web page. The browser knows to send + the request to Privoxy, which will in turn, + relay the request to the remote web server after passing the following + tests: + + + + + Privoxy traps any request for its own internal CGI + pages (e.g http://p.p/) and sends the CGI page back to the browser. + + + + + Next, Privoxy checks to see if the URL + matches any +block patterns. If + so, the URL is then blocked, and the remote web server will not be contacted. + +handle-as-image + and + +handle-as-empty-document + are then checked, and if there is no match, an + HTML BLOCKED 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 + +set-image-blocker + (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere). + + + + + Untrusted URLs are blocked. If URLs are being added to the + trust file, then that is done. + + + + + If the URL pattern matches the +fast-redirects action, + it is then processed. Unwanted parts of the requested URL are stripped. + + + + + Now the rest of the client browser's request headers are processed. If any + of these match any of the relevant actions (e.g. +hide-user-agent, + etc.), headers are suppressed or forged as determined by these actions and + their parameters. + + + + + Now the web server starts sending its response back (i.e. typically a web + page). + + + + + 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 + +crunch-incoming-cookies, + +session-cookies-only, + and +downgrade-http-version + actions. + + + + + If any +filter action + or +deanimate-gifs + 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 + default.filter 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 + Privoxy back to your browser. + + + If neither a +filter action + or +deanimate-gifs + matches, then Privoxy passes the raw data through + to the client browser as it becomes available. + + + + + 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 Privoxy's + 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. + + - Revision 1.67 2002/04/04 17:27:57 swa - more single file to be included at multiple points. make maintaining easier + + + + 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 + Privoxy's core features only. + - 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. + - 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. + + +Troubleshooting: Anatomy of an Action - Revision 1.63 2002/04/01 16:24:49 hal9 - Define entities to include boilerplate text. See doc/source/*. + + The way Privoxy applies + actions and filters + 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 + see just what Privoxy is + doing. Especially, if something Privoxy 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 + regular expressions whose consequences are not + always so obvious. + - 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. + + One quick test to see if Privoxy 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 config file settings, and may need to be + turned on.) + + + 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. + - Revision 1.61 2002/03/29 01:31:08 hal9 - Minor update. + + Privoxy also provides the + http://config.privoxy.org/show-url-info + page that can show us very specifically how actions + are being applied to any given URL. This is a big help for troubleshooting. + - Revision 1.60 2002/03/27 01:57:34 hal9 - Added more to Anatomy section. + + First, enter one URL (or partial URL) at the prompt, and then + Privoxy will tell us + how the current configuration will handle it. This will not + help with filtering effects (i.e. the +filter 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 View + Page Source option for this. Or right click on the ad, and grab the + URL. + - Revision 1.59 2002/03/27 00:54:33 hal9 - Touch up intro for new name. + + Let's try an example, google.com, + and look at it one section at a time in a sample configuration (your real + configuration may vary): + - Revision 1.58 2002/03/26 22:29:55 swa - we have a new homepage! + + + 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 [ View ] [ Edit ] - 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 [ View ] [ Edit ] +(no matches in this file) + + - Revision 1.52 2002/03/24 11:01:06 swa - name change + + This is telling us how we have defined our + actions, and + which ones match for our test case, google.com. + Displayed is all the actions that are available to us. Remember, + the + sign denotes on. - + denotes off. So some are on here, but many + are off. Each example we try may provide a slightly different + end result, depending on our configuration directives. + + + The first listing + is for our default.action 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 actions file, this would be the + section just below the aliases section near the top. This + will apply to all URLs as signified by the single forward slash at the end + of the listing -- / . + - 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. + + 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 .google.com. The first is negating our previous + cookie setting, which was for +session-cookies-only + (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 + off any +fast-redirects + action, allowing this to take place unmolested. Note that there is a leading + dot here -- .google.com. This will match any hosts and + sub-domains, in the google.com domain also, such as + www.google.com or mail.google.com. But it would not + match www.google.de! So, apparently, we have these two actions + defined as exceptions to the general rules at the top somewhere in the lower + part of our default.action file, and + google.com is referenced somewhere in these latter sections. + - Revision 1.50 2002/03/23 05:06:21 hal9 - Touch up. + + Then, for our user.action 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 default.action. + user.action typically has the last word. This is the + best place to put hard and fast exceptions, + - Revision 1.49 2002/03/21 17:01:05 hal9 - New section in Appendix. + + And finally we pull it all together in the bottom section and summarize how + Privoxy is applying all its actions + to google.com: - Revision 1.48 2002/03/12 06:33:01 hal9 - Catching up to Andreas and re_filterfile changes. + - Revision 1.47 2002/03/11 13:13:27 swa - correct feedback channels + + - 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} + - Revision 1.44 2002/03/09 17:08:48 hal9 - New section on Jon's actions file editor, and move some stuff around. + + Notice the only difference here to the previous listing, is to + fast-redirects and session-cookies-only, + which are activated specifically for this site in our configuration, + and thus show in the Final Results. + - Revision 1.43 2002/03/08 00:47:32 hal9 - Added imageblock{pattern}. + + Now another example, ad.doubleclick.net: + - Revision 1.42 2002/03/07 18:16:55 swa - looks better + + - 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 + + - Revision 1.38 2002/03/05 23:55:14 hal9 - Stupid I did it again. Double hyphen in comment breaks jade. + + We'll just show the interesting part here - the explicit matches. It is + matched three different times. Two +block{} sections, + and a +block{} +handle-as-image, + which is the expanded form of one of our aliases that had been defined as: + +block-as-image. (Aliases are defined in + the first section of the actions file and typically used to combine more + than one action.) + - Revision 1.37 2002/03/05 23:53:49 hal9 - jade barfs on '- -' embedded in comments. - -user option broke it. + + 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 ad.doubleclick.net + is done here -- as both a +block{} + and an + +handle-as-image. + The custom alias +block-as-image just + simplifies the process and make it more readable. + - Revision 1.36 2002/03/05 22:53:28 hal9 - Add new - - user option. + + One last example. Let's try http://www.example.net/adsl/HOWTO/. + This one is giving us problems. We are getting a blank page. Hmmm ... + - Revision 1.35 2002/03/05 00:17:27 hal9 - Added section on command line options. + + - 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 [ View ] [ Edit ] - 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 + + - Revision 1.30 2002/03/02 22:00:14 hal9 - Updated 'New Features' list. Ran through spell-checker. + + Ooops, the /adsl/ is matching /ads 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 + user.action file) that explicitly + un blocks ( + {-block}) paths with + adsl in them (remember, last match in the configuration + wins). There are various ways to handle such exceptions. Example: + - Revision 1.29 2002/03/02 20:34:07 david__schmidt - Update OS/2 build section + + - 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 + + - Revision 1.27 2002/01/11 14:14:32 hal9 - Added a very short section on Templates + + 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 Shift+Reload. + - Revision 1.26 2002/01/09 20:02:50 hal9 - Fix bug re: auto-detect config file changes. + + But now what about a situation where we get no explicit matches like + we did with: + - Revision 1.25 2002/01/09 18:20:30 hal9 - Touch ups for *.action files. + + - Revision 1.24 2001/12/02 01:13:42 hal9 - Fix typo. + { +block{Path starts with "ads".} +handle-as-image } + /ads + + - Revision 1.23 2001/12/02 00:20:41 hal9 - Updates for recent changes. + + 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 default.action 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 + +filter actions. + These tend to be harder to troubleshoot. + Try adding the URL for the site to one of aliases that turn off + +filter: + - Revision 1.22 2001/11/05 23:57:51 hal9 - Minor update for startup now daemon mode. + + - 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 + + - Revision 1.18 2001/10/24 18:45:26 hal9 - *** empty log message *** + + { shop } is an alias that expands to + { -filter -session-cookies-only }. + 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. + - Revision 1.16 2001/10/21 17:19:21 swa - wrong url in documentation + + - 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 + + - Revision 1.13 2001/10/10 17:28:33 hal9 - Very minor changes. + + This would turn off all filtering for these sites. This is best + put in user.action, 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. + - Revision 1.12 2001/09/28 02:57:04 hal9 - Ditto :/ + + Images that are inexplicably being blocked, may well be hitting the ++filter{banners-by-size} + rule, which assumes + that images of certain sizes are ad banners (works well + most of the time since these tend to be standardized). + - Revision 1.11 2001/09/28 02:25:20 hal9 - Ditto. + + { fragile } 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. + + + - 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 + - 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. + + Remember to flush caches! Note that the + mail.google reference lacks the TLD portion (e.g. + .com). This will effectively match any TLD with + google in it, such as mail.google.de., + just as an example. + + + 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. + - Revision 1.6 2001/09/24 14:10:32 hal9 - Including David's OS/2 installation instructions. + - Revision 1.2 2001/09/13 15:27:40 swa - cosmetics + - Revision 1.1 2001/09/12 15:36:41 swa - source files for junkbuster documentation +