X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Fsource%2Fuser-manual.sgml;h=ef21bd299b4a97f7363d096416ed4b4f83bcf755;hp=8e7f2b7800cbe79219e271034d61035d41d9f9e6;hb=f6d1a7ca82613239a15439cc9b3613750d5f55c5;hpb=2f137f1efa164b295bd81d3ed3482ddfdc310aae diff --git a/doc/source/user-manual.sgml b/doc/source/user-manual.sgml index 8e7f2b78..ef21bd29 100644 --- a/doc/source/user-manual.sgml +++ b/doc/source/user-manual.sgml @@ -1,5 +1,5 @@ + @@ -11,8 +11,8 @@ - - + + @@ -34,13 +34,13 @@ This file belongs into ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/ - $Id: user-manual.sgml,v 2.118 2010/02/11 13:59:48 fabiankeil Exp $ + $Id: user-manual.sgml,v 2.159 2013/01/09 15:03:06 fabiankeil Exp $ - Copyright (C) 2001-2010 Privoxy Developers http://www.privoxy.org/ + Copyright (C) 2001-2013 Privoxy Developers http://www.privoxy.org/ See LICENSE. ======================================================================== - NOTE: Please read developer-manual/documentation.html before touching + NOTE: Please read developer-manual/documentation.html before touching anything in this, or other Privoxy documentation. ======================================================================== @@ -55,12 +55,12 @@ - Copyright &my-copy; 2001-2010 by + Copyright &my-copy; 2001-2013 by Privoxy Developers -$Id: user-manual.sgml,v 2.118 2010/02/11 13:59:48 fabiankeil Exp $ +$Id: user-manual.sgml,v 2.159 2013/01/09 15:03:06 fabiankeil Exp $ Features - In addition to the core - features of ad blocking and + In addition to the core + features of ad blocking and cookie management, Privoxy provides many supplemental - features, + features, that give the end-user more control, more privacy and more freedom: @@ -165,14 +165,14 @@ Hal. - Note: - On some platforms, the installer may remove previously installed versions, if + Note: + On some platforms, the installer may remove previously installed versions, if found. (See below for your platform). In any case be sure to backup your old configuration if it is valuable to you. See the note to upgraders section below. - + Binary Packages How to install the binary packages depends on your operating system: @@ -185,7 +185,7 @@ How to install the binary packages depends on your operating system: RPMs can be installed with rpm -Uvh privoxy-&p-version;-1.rpm, - and will use /etc/privoxy for the location + and will use /etc/privoxy for the location of configuration files. @@ -193,13 +193,13 @@ How to install the binary packages depends on your operating system: 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. + 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. + 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. @@ -214,7 +214,7 @@ How to install the binary packages depends on your operating system: Debian and Ubuntu DEBs can be installed with apt-get install privoxy, - and will use /etc/privoxy for the location of + and will use /etc/privoxy for the location of configuration files. @@ -225,7 +225,7 @@ How to install the binary packages depends on your operating system: Just double-click the installer, which will guide you through the installation process. You will find the configuration files - in the same directory as you installed Privoxy in. + in the same directory as you installed Privoxy in. Version 3.0.5 beta introduced full Windows service @@ -256,7 +256,7 @@ How to install the binary packages depends on your operating system: command: services.msc. If you do not take the manual step of modifying Privoxy's service settings, it will not start. Note too that you will need to give Privoxy a user account that - actually exists, or it will not be permitted to + actually exists, or it will not be permitted to write to its log and configuration files. @@ -277,7 +277,7 @@ How to install the binary packages depends on your operating system: First, make sure that no previous installations of - Junkbuster and / or + Junkbuster and / or Privoxy are left on your system. Check that no Junkbuster or Privoxy objects are in @@ -301,31 +301,83 @@ 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 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. + + + 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'). + + + 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. + + + +Installation from source + + 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. + + + 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 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. + 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'). 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). + 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. + + + To uninstall, run the macsetup module's uninstall.sh as sudo from an + administrator account. AmigaOS - Copy and then unpack the lha archive to a suitable location. + 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 + directory, including all configuration and log files. To uninstall, just remove this directory. @@ -352,19 +404,19 @@ How to install the binary packages depends on your operating system: 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 + 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). - 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 + 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. - Configuration files are in /etc/privoxy, the + 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. @@ -377,7 +429,7 @@ How to install the binary packages depends on your operating system: The most convenient way to obtain the Privoxy sources - is to download the source tarball from our + is to download the source tarball from our project download page. @@ -386,8 +438,8 @@ How to install the binary packages depends on your operating system: If you like to live on the bleeding edge and are not afraid of using possibly unstable development versions, you can check out the up-to-the-minute version directly from the - CVS repository. - - + 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 @@ -420,7 +465,7 @@ How to install the binary packages depends on your operating system: In order not to lose your personal changes and adjustments when updating to the latest default.action file we strongly - recommend that you use user.action and + recommend that you use user.action and user.filter for your local customizations of Privoxy. See the Chapter on actions files for details. @@ -437,4603 +482,3201 @@ How to install the binary packages depends on your operating system: What's New in this Release - Privoxy 3.0.16 is a stable release. - The changes since 3.0.15 beta are: + Privoxy 3.0.19 is a stable release. + The changes since 3.0.18 stable are: - - - Added the config file option handle-as-empty-doc-returns-ok to - work around Firefox bug #492459, which causes Firefox to hang - if JavaScripts are blocked in certain situations. The option is - enabled in the default config file. - - - - - Added the config option default-server-timeout to control the - assumed default server timeout. Since Privoxy no longer returns - an error message for connection resets on reused client connections, - assuming larger server timeout values appears to actually work - pretty well as long as connections aren't shared. - - - - - Added optional support for FreeBSD's accf_http(9). Use the - configure option --enable-accept-filter to enable it. - - - - - Added fancier Privoxy icons for win32. Contributed by Jeff H. - - - - - In daemon mode, fd 0, 1 and 2 are bound to /dev/null. - - - - - Resolve localhost using whatever address family the operating - system feels like. Previous betas would try to use IPv4 as this - is what most users expect, but this didn't work reliable on - GNU/Linux systems. - - - - - In the action lists on CGI pages, actions and their parameters are - no longer separated with a space. The action file parser doesn't - actually allow this and will throw an invalid syntax error if actions - and parameters in the action files are separated. Not adding the - spaces means copy and pasting CGI output into the action files works. - - - - - The default keep-alive timeout has been reduced to 5 seconds to work - around hangs in clients that treat the proxy like any other host and - stop allowing any new connections if the "maximum number of - connections per host" is reached. - - - - - Several webbug URLs that look like they are leading to images are now - blocked as image instead of empty documents. Doing the latter causes - WebKit-based clients to show a "missing image" icon which may mess up - the layout. - - - - - Accepts quoted expiration dates even though RFC 2109 10.1.2 - doesn't seem to allow them. Reported anonymously. - - - - - Don't try to forget connections if connection sharing is disabled. - This wasn't a real problem but caused an unnecessary log message. - - - - - The still undocumented --enable-extended-host-patterns configure - option has a better description. - - - - - Fixed an error message that would claim a write to the server - failed when actually writing to the client failed. - - - - - Log the crunch reason before trying to write to the client. - The log is easier to read that way. - - - - - Several log messages about client connections also mention - the socket number. - - - - - handle-as-empty-document no longer depends on the image blocking - code being enabled. - - - - - Privoxy-Log-Parser is roughly 40% faster in highlighting mode. - - - + - uagen, a Firefox User-Agent generator for Privoxy and Mozilla - browsers has been imported and is available in the tarballs - tools directory. + Bug fixes: + + + + Prevent a segmentation fault when de-chunking buffered content. + It could be triggered by malicious web servers if Privoxy was + configured to filter the content and running on a platform + where SIZE_T_MAX isn't larger than UINT_MAX, which probably + includes most 32-bit systems. On those platforms, all Privoxy + versions before 3.0.19 appear to be affected. + To be on the safe side, this bug should be presumed to allow + code execution as proving that it doesn't seems unrealistic. + + + + + Do not expect a response from the SOCKS4/4A server until it + got something to respond to. This regression was introduced + in 3.0.18 and prevented the SOCKS4/4A negotiation from working. + Reported by qqqqqw in #3459781. + + + - The scripts in the tools directory treat unknown parameters - as fatal errors. + General improvements: + + + + Fix an off-by-one in an error message about connect failures. + + + + + Use a GNUMakefile variable for the webserver root directory and + update the path. Sourceforge changed it which broke various + web-related targets. + + + + + Update the CODE_STATUS description. + + + - If you missed the previous two beta versions, you may also be - interested in the additional changes since 3.0.12, the - last stable release: + The following changes were made between 3.0.17 and 3.0.18: - Added IPv6 support. Thanks to Petr Pisar who not only provided - the initial patch but also helped a lot with the integration. - - - - - Added client-side keep-alive support. - - - - - The connection sharing code is only used if the connection-sharing - option is enabled. - - - - - The latency is taken into account when evaluating whether or not to - reuse a connection. This should significantly reduce the number of - connections problems several users reported. - - - - - The max-client-connections option has been added to restrict - the number of client connections below a value enforced by - the operating system. - - - - - If the server doesn't specify how long the connection stays alive, - Privoxy errs on the safe side of caution and assumes it's only a second. - - - - - Setting keep-alive-timeout to 0 disables keep-alive support. Previously - Privoxy would claim to allow persistence but not reuse the connection. - - - - - Pipelined requests are less likely to be mistaken for the request - body of the previous request. Note that Privoxy still has no real - pipeline support and will either serialize pipelined requests or - drop them in which case the client has to resent them. - - - - - Fixed a crash on some Windows versions when header randomization - is enabled and the date couldn't be parsed. - - - - - Privoxy's keep-alive timeout for the current connection is reduced - to the one specified in the client's Keep-Alive header. - - - - - For HTTP/1.1 requests, Privoxy implies keep-alive support by not - setting any Connection header instead of using 'Connection: keep-alive'. - - - - - If the socket isn't reusable, Privoxy doesn't temporarily waste - a socket slot to remember the connection. - - - - - If keep-alive support is disabled but compiled in, the client's - Keep-Alive header is removed. - - - - - Fixed a bug on mingw32 where downloading large files failed if - keep-alive support was enabled. - - - - - Fixed a bug that (at least theoretically) could cause log - timestamps to be occasionally off by about a second. - - - - - The configure script respects the $PATH variable when searching - for groups and id. - - - - - Compressed content with extra fields couldn't be decompressed - and would get passed to the client unfiltered. This problem - has only be detected through statical analysis with clang as - nobody seems to be using extra fields anyway. - - - - - If the server resets the Connection after sending only the headers - Privoxy forwards what it got to the client. Previously Privoxy - would deliver an error message instead. - - - - - Error messages in case of connection timeouts use the right - HTTP status code. - - - - - If spawning a child to handle a request fails, the client - gets an error message and Privoxy continues to listen for - new requests right away. - - - - - The error messages in case of server-connection timeouts or - prematurely closed server connections are now template-based. - - - - - If zlib support isn't compiled in, Privoxy no longer tries to - filter compressed content unless explicitly asked to do so. - - - - - In case of connections that are denied based on ACL directives, - the memory used for the client IP is no longer leaked. - - - - - Fixed another small memory leak if the client request times out - while waiting for client headers other than the request line. + Bug fixes: + + + + If a generated redirect URL contains characters RFC 3986 doesn't + permit, they are (re)encoded. Not doing this makes Privoxy versions + from 3.0.5 to 3.0.17 susceptible to HTTP response splitting (CWE-113) + attacks if the +fast-redirects{check-decoded-url} action is used. + + + + + Fix a logic bug that could cause Privoxy to reuse a server + socket after it got tainted by a server-header-tagger-induced + block that was triggered before the whole server response had + been read. If keep-alive was enabled and the request following + the blocked one was to the same host and using the same forwarding + settings, Privoxy would send it on the tainted server socket. + While the server would simply treat it as a pipelined request, + Privoxy would later on fail to properly parse the server's + response as it would try to parse the unread data from the + first response as server headers for the second one. + Regression introduced in 3.0.17. + + + + + When implying keep-alive in client_connection(), remember that + the client didn't. Fixes a regression introduced in 3.0.13 that + would cause Privoxy to wait for additional client requests after + receiving a HTTP/1.1 request with "Connection: close" set + and connection sharing enabled. + With clients which terminates the client connection after detecting + that the whole body has been received it doesn't really matter, + but with clients that don't the connection would be kept open until + it timed out. + + + + + Fix a subtle race condition between prepare_csp_for_next_request() + and sweep(). A thread preparing itself for the next client request + could briefly appear to be inactive. + If all other threads were already using more recent files, + the thread could get its files swept away under its feet. + So far this has only been reproduced while stress testing in + valgrind while touching action files in a loop. It's unlikely + to have caused any actual problems in the real world. + + + + + Disable filters if SDCH compression is used unless filtering is forced. + If SDCH was combined with a supported compression algorithm, Privoxy + previously could try to decompress it and ditch the Content-Encoding + header even though the SDCH compression wasn't dealt with. + Reported by zebul666 in #3225863. + + + + + Make a copy of the --user value and only mess with that when splitting + user and group. On some operating systems modifying the value directly + is reflected in the output of ps and friends and can be misleading. + Reported by zepard in #3292710. + + + + + If forwarded-connect-retries is set, only retry if Privoxy is actually + forwarding the request. Previously direct connections would be retried + as well. + + + + + Fixed a small memory leak when retrying connections with IPv6 + support enabled. + + + + + Remove an incorrect assertion in compile_dynamic_pcrs_job_list() + It could be triggered by a pcrs job with an invalid pcre + pattern (for example one that contains a lone quantifier). + + + + + If the --user argument user[.group] contains a dot, always bail out + if no group has been specified. Previously the intended, but undocumented + (and apparently untested), behaviour was to try interpreting the whole + argument as user name, but the detection was flawed and checked for '0' + instead of '\0', thus merely preventing group names beginning with a zero. + + + + + In html_code_map[], use a numeric character reference instead of ' + which wasn't standardized before XHTML 1.0. + + + + + Fix an invalid free when compiled with FEATURE_GRACEFUL_TERMINATION + and shut down through http://config.privoxy.org/die + + + + + In get_actions(), fix the "temporary" backwards compatibility hack + to accept block actions without reason. + It also covered other actions that should be rejected as invalid. + Reported by Billy Crook. + + + - The client socket is kept open until the server socket has - been marked as unused. This should increase the chances that - the still-open connection will be reused for the client's next - request to the same destination. Note that this only matters - if connection-sharing is enabled. - - - - - A TODO list has been added to the source tarballs to give potential - volunteers a better idea of what the current goals are. Donations - are still welcome too: http://www.privoxy.org/faq/general.html#DONATE - - - - - In case of missing server data, no error message is send to the - client if the request arrived on a reused connection. The client - is then supposed to silently retry the request without bothering - the user. This should significantly reduce the frequency of the - "No server or forwarder data received" error message many users - reported. - - - - - More reliable detection of prematurely closed client sockets - with keep-alive enabled. - - - - - FEATURE_CONNECTION_KEEP_ALIVE is decoupled from - FEATURE_CONNECTION_SHARING and now available on - all platforms. - - - - - Improved handling of POST requests on reused connections. - Should fix problems with stalled connections after submitting - form data with some browser configurations. - - - - - Fixed various latency calculation issues. - - - - - Allows the client to pass NTLM authentication requests to a - forwarding proxy. This was already assumed and hinted to work - in 3.0.13 beta but actually didn't. Now it's confirmed to work - with IE, Firefox and Chrome. - Thanks to Francois Botha and Wan-Teh Chang - - - - - Fixed a calculation problem if receiving the server headers - takes more than two reads, that could cause Privoxy to terminate - the connection prematurely. Reported by Oliver. - - - - - Compiles again on platforms such as OpenBSD and systems - using earlier glibc version that don't support AI_ADDRCONFIG. - Anonymously submitted in #2872591. - - - - - A bunch of MS VC project files and Suse and Redhat RPM spec - files have been removed as they were no longer maintained for - quite some time. - - - - - Overly long action lines are properly rejected with a proper - error message. Previously they would be either rejected as - invalid or cause a core dump through abort(). - - - - - Already timed-out connections are no longer temporarily remembered. - They weren't reused anyway, but wasted a socket slot. - - - - - len refers to the number of bytes actually read which might - differ from the ones received. Adjust log messages accordingly. - - - - - The optional JavaScript on the CGI page uses encodeURIComponent() - instead of escape() which doesn't encode all characters that matter. - Anonymously reported in #2832722. - - - - - Fix gcc45 warnings in decompress_iob(). - - - - - Various log message improvements. - - - - - Privoxy-Regression-Test supports redirect tests. - - - - - Privoxy-Log-Parser can gather some connection statistics. - - - - - - - - - - -Note to Upgraders - - - A quick list of things to be aware of before upgrading from earlier - versions of 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. - - - - - 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 - service to more than just their local machine should check the main config file, especially the security-relevant options. These are - off by default. - - - - - - Start Privoxy, if the installation program has - not done this already (may vary according to platform). See the section - Starting Privoxy. - - - - - - Set your browser to use Privoxy as HTTP and - HTTPS (SSL) proxy - by setting the proxy configuration for address of - 127.0.0.1 and port 8118. - DO NOT activate proxying for FTP or - any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your - browser from using these protocols. - - - - - - Flush your browser's disk and memory caches, to remove any cached ad images. - If using Privoxy to manage - cookies, - you should remove any currently stored cookies too. - - - - - - A default installation should provide a reasonable starting point for - most. There will undoubtedly be occasions where you will want to adjust the - configuration, but that can be dealt with as the need arises. Little - to no initial configuration is required in most cases, you may want - to enable the - web-based action editor though. - Be sure to read the warnings first. - - - See the Configuration section for more - configuration options, and how to customize your installation. - You might also want to look at the next section for a quick - introduction to how Privoxy blocks ads and - banners. - - - - - - If you experience ads that slip through, innocent images that are - blocked, or otherwise feel the need to fine-tune - Privoxy's behavior, take a look at the actions files. As a quick start, you might - find the richly commented examples - helpful. You can also view and edit the actions files through the web-based user interface. The - Appendix Troubleshooting: Anatomy of an - Action has hints on how to understand and debug actions that - misbehave. - - - - - - - - Please see the section Contacting the - Developers on how to report bugs, problems with websites or to get - help. - - - - - - Now enjoy surfing with enhanced control, comfort and privacy! - - - - - - - - - - -Quickstart to Ad Blocking - - - Ad blocking is but one of Privoxy's - array of features. Many of these features are for the technically minded advanced - user. But, ad and banner blocking is surely common ground for everybody. - - - This section will provide a quick summary of ad blocking so - you can get up to speed quickly without having to read the more extensive - information provided below, though this is highly recommended. - - - First a bit of a warning ... blocking ads is much like blocking SPAM: the - more aggressive you are about it, the more likely you are to block - things that were not intended. And the more likely that some things - may not work as intended. So there is a trade off here. If you want - extreme ad free browsing, be prepared to deal with more - problem sites, and to spend more time adjusting the - configuration to solve these unintended consequences. In short, there is - not an easy way to eliminate all ads. Either take - the easy way and settle for most ads blocked with the - default configuration, or jump in and tweak it for your personal surfing - habits and preferences. - - - Secondly, a brief explanation of Privoxy's - actions. Actions in this context, are - the directives we use to tell Privoxy to perform - some task relating to HTTP transactions (i.e. web browsing). We tell - Privoxy to take some action. Each - action has a unique name and function. While there are many potential - actions in Privoxy's - arsenal, only a few are used for ad blocking. Actions, and action - configuration files, are explained in depth below. - - - Actions are specified in Privoxy's configuration, - followed by one or more URLs to which the action should apply. URLs - can actually be URL type patterns that use - wildcards so they can apply potentially to a range of similar URLs. The - actions, together with the URL patterns are called a section. - - - When you connect to a website, the full URL will either match one or more - of the sections as defined in Privoxy's configuration, - or not. If so, then Privoxy will perform the - respective actions. If not, then nothing special happens. Furthermore, web - pages may contain embedded, secondary URLs that your web browser will - use to load additional components of the page, as it parses the - original page's HTML content. An ad image for instance, is just an URL - embedded in the page somewhere. The image itself may be on the same server, - or a server somewhere else on the Internet. Complex web pages will have many - such embedded URLs. &my-app; can deal with each URL individually, so, for - instance, the main page text is not touched, but images from such-and-such - server are blocked. - - - - The most important actions for basic ad blocking are: block, handle-as-image, - handle-as-empty-document,and - set-image-blocker: - - - - - - - - block - this is perhaps - the single most used action, and is particularly important for ad blocking. - This action stops any contact between your browser and any URL patterns - that match this action's configuration. It can be used for blocking ads, - but also anything that is determined to be unwanted. By itself, it simply - stops any communication with the remote server and sends - Privoxy's own built-in BLOCKED page instead to - let you now what has happened (with some exceptions, see below). - - - - - - handle-as-image - - tells Privoxy to treat this URL as an image. - Privoxy's default configuration already does this - for all common image types (e.g. GIF), but there are many situations where this - is not so easy to determine. So we'll force it in these cases. This is particularly - important for ad blocking, since only if we know that it's an image of - some kind, can we replace it with an image of our choosing, instead of the - Privoxy BLOCKED page (which would only result in - a broken image icon). There are some limitations to this - though. For instance, you can't just brute-force an image substitution for - an entire HTML page in most situations. - - - - - - handle-as-empty-document - - sends an empty document instead of Privoxy's - normal BLOCKED HTML page. This is useful for file types that are neither - HTML nor images, such as blocking JavaScript files. - - - - - - set-image-blocker - tells - Privoxy what to display in place of an ad image that - has hit a block rule. For this to come into play, the URL must match a - block action somewhere in the - configuration, and, it must also match an - handle-as-image action. - - - The configuration options on what to display instead of the ad are: - - - -    pattern - a checkerboard pattern, so that an ad - replacement is obvious. This is the default. - - - - -    blank - A very small empty GIF image is displayed. - This is the so-called invisible configuration option. - - - - -    http://<URL> - A redirect to any image anywhere - of the user's choosing (advanced usage). - - - - - - - - - Advanced users will eventually want to explore &my-app; - filters as well. Filters - are very different from blocks. - A block blocks a site, page, or unwanted contented. Filters - are a way of filtering or modifying what is actually on the page. An example - filter usage: a text replacement of no-no for - nasty-word. That is a very simple example. This process can be - used for ad blocking, but it is more in the realm of advanced usage and has - some pitfalls to be wary off. - - - - The quickest way to adjust any of these settings is with your browser through - the special Privoxy editor at http://config.privoxy.org/show-status - (shortcut: http://p.p/show-status). This - is an internal page, and does not require Internet access. - - - - Note that as of Privoxy 3.0.7 beta the - action editor is disabled by default. Check the - enable-edit-actions - section in the configuration file to learn why and in which - cases it's safe to enable again. - - - - If you decided to enable the action editor, select the appropriate - actions file, and click - Edit. It is best to put personal or - local preferences in user.action since this is not - meant to be overwritten during upgrades, and will over-ride the settings in - other files. Here you can insert new actions, and URLs for ad - blocking or other purposes, and make other adjustments to the configuration. - Privoxy will detect these changes automatically. - - - - A quick and simple step by step example: - - - - - - - - Right click on the ad image to be blocked, then select - Copy Link Location from the - pop-up menu. - - - - - Set your browser to - http://config.privoxy.org/show-status - - - - - Find user.action in the top section, and click - on Edit: - - - - -
Actions Files in Use - - - - - - [ Screenshot of Actions Files in Use ] - - -
- - - - - - You should have a section with only - block listed under - Actions:. - If not, click a Insert new section below - button, and in the new section that just appeared, click the - Edit button right under the word Actions:. - This will bring up a list of all actions. Find - block near the top, and click - in the Enabled column, then Submit - just below the list. - - - - - Now, in the block actions section, - click the Add button, and paste the URL the - browser got from Copy Link Location. - Remove the http:// at the beginning of the URL. Then, click - Submit (or - OK if in a pop-up window). - - - - - Now go back to the original page, and press SHIFT-Reload - (or flush all browser caches). The image should be gone now. - - - - - - - - This is a very crude and simple example. There might be good reasons to use a - wildcard pattern match to include potentially similar images from the same - site. For a more extensive explanation of patterns, and - the entire actions concept, see the Actions - section. - - - - For advanced users who want to hand edit their config files, you might want - to now go to the Actions Files Tutorial. - The ideas explained therein also apply to the web-based editor. - - - There are also various - filters that can be used for ad blocking - (filters are a special subset of actions). These - fall into the advanced usage category, and are explained in - depth in later sections. - - - - - - - - - - - -Starting Privoxy - - Before launching Privoxy for the first time, you - will want to configure your browser(s) to use - Privoxy as a HTTP and HTTPS (SSL) - proxy. The default is - 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions - used port 8000). This is the one configuration step that must be done -! - - - Please note that Privoxy can only proxy HTTP and - HTTPS traffic. It will not work with FTP or other protocols. - - - - -
Proxy Configuration Showing - Mozilla/Netscape HTTP and HTTPS (SSL) Settings - - - - - - [ Screenshot of Mozilla Proxy Configuration ] - - -
- - - - - With Firefox, this is typically set under: - - - - Tools -> Options -> Advanced -> Network ->Connection -> Settings - - - - - Or optionally on some platforms: - - - - Edit -> Preferences -> General -> Connection Settings -> Manual Proxy Configuration - - - - - - With Netscape (and - Mozilla), this can be set under: - - - - - - - Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy - - - - - For Internet Explorer v.5-7: - - - - Tools -> Internet Options -> Connections -> LAN Settings - - - - Then, check Use Proxy and fill in the appropriate info - (Address: 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS - proxy support too (sometimes labeled Secure). Make sure any - checkboxes like Use the same proxy server for all protocols is - UNCHECKED. You want only HTTP and HTTPS (SSL)! - - - - -
Proxy Configuration Showing - Internet Explorer HTTP and HTTPS (Secure) Settings - - - - - - [ Screenshot of IE Proxy Configuration ] - - -
- - - - - After doing this, flush your browser's disk and memory caches to force a - re-reading of all pages and to get rid of any ads that may be cached. Remove - any cookies, - if you want Privoxy to manage that. You are now - ready to start enjoying the benefits of using - Privoxy! - - - - Privoxy itself is typically started by specifying the - main configuration file to be used on the command line. If no configuration - file is specified on the command line, Privoxy - will look for a file named config in the current - directory. Except on Win32 where it will try config.txt. - - - -Red Hat and Fedora - - A default Red Hat installation may not start &my-app; upon boot. It will use - the file /etc/privoxy/config as its main configuration - file. - - - - # /etc/rc.d/init.d/privoxy start - - - - Or ... - - - - # service privoxy start - - - - - -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. - - - - # /etc/init.d/privoxy start - - - - - -Windows - -Click on the &my-app; Icon to start Privoxy. If no configuration file is - specified on the command line, Privoxy will look - for a file named config.txt. Note that Windows will - automatically start &my-app; when the system starts if you chose that option - when installing. - - - Privoxy can run with full Windows service functionality. - On Windows only, the &my-app; program has two new command line arguments - to install and uninstall &my-app; as a service. See the - Windows Installation - instructions for details. - - - - -Solaris, NetBSD, FreeBSD, HP-UX and others - -Example Unix startup command: - - - - # /usr/sbin/privoxy /etc/privoxy/config - - - - - -OS/2 - - During installation, Privoxy is configured to - start automatically when the system restarts. You can start it manually by - double-clicking on the Privoxy icon in the - Privoxy folder. - - - - -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. - - - An administrator username and password must be supplied in order for - the Privoxy Utility to perform any of the tasks. - - - - - -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). - - - - -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 - - - - - - - - -Command Line Options - - Privoxy may be invoked with the following - command-line options: - - - - - - - - --version - - - Print version info and exit. Unix only. - - - - - --help - - - Print short usage info and exit. Unix only. - - - - - --no-daemon - - - Don't become a daemon, i.e. don't fork and become process group - leader, and don't detach from controlling tty. Unix only. - - - - - --pidfile FILE - - - On startup, write the process ID to FILE. Delete the - FILE on exit. Failure to create or delete the - FILE is non-fatal. If no FILE - option is given, no PID file will be used. Unix only. - - - - - --user USER[.GROUP] - - - After (optionally) writing the PID file, assume the user ID of - USER, and if included the GID of GROUP. Exit if the - privileges are not sufficient to do so. Unix only. - - - - - --chroot - - - Before changing to the user ID given in the --user option, - chroot to that user's home directory, i.e. make the kernel pretend to the &my-app; - process that the directory tree starts there. If set up carefully, this can limit - the impact of possible vulnerabilities in &my-app; to the files contained in that hierarchy. - Unix only. - - - - - --pre-chroot-nslookup hostname - - - Specifies a hostname to look up before doing a chroot. On some systems, initializing the - resolver library involves reading config files from /etc and/or loading additional shared - libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces - the number of files that must be copied into the chroot tree. - - - For fastest startup speed, a good value is a hostname that is not in /etc/hosts but that - your local name server (listed in /etc/resolv.conf) can resolve without recursion - (that is, without having to ask any other name servers). The hostname need not exist, - but if it doesn't, an error message (which can be ignored) will be output. - - - - - - configfile - - - If no configfile is included on the command line, - Privoxy will look for a file named - config in the current directory (except on Win32 - where it will look for config.txt instead). Specify - full path to avoid confusion. If no config file is found, - Privoxy will fail to start. - - - - - - - - On MS Windows only there are two additional - command-line options to allow Privoxy to install and - run as a service. See the -Window Installation section -for details. - - - - - - - - - - -Privoxy Configuration - - All Privoxy configuration is stored - in text files. These files can be edited with a text editor. - Many important aspects of Privoxy can - also be controlled easily with a web browser. - - - - - - -Controlling Privoxy with Your Web Browser - - Privoxy's user interface can be reached through the special - URL http://config.privoxy.org/ - (shortcut: http://p.p/), - which is a built-in page and works without Internet access. - You will see the following section: - - - - - - -     Privoxy Menu - - - -         ▪  View & change the current configuration - - -         ▪  View the source code version numbers - - -         ▪  View the request headers. - - -         ▪  Look up which actions apply to a URL and why - - -         ▪  Toggle Privoxy on or off - - -         ▪  Documentation - - - - - - - - This should be self-explanatory. Note the first item leads to an editor for the - actions files, which is where the ad, banner, - cookie, and URL blocking magic is configured as well as other advanced features of - Privoxy. This is an easy way to adjust various - aspects of Privoxy configuration. The actions - file, and other configuration files, are explained in detail below. - - - - Toggle Privoxy On or Off is handy for sites that might - have problems with your current actions and filters. You can in fact use - 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. - - - - Note that several of the features described above are disabled by default - in Privoxy 3.0.7 beta and later. - Check the - configuration file to learn why - and in which cases it's safe to enable them again. - - - - - - - - - - - - -Configuration Files Overview - - For Unix, *BSD and Linux, all configuration files are located in - /etc/privoxy/ by default. For MS Windows, OS/2, and - AmigaOS these are all in the same directory as the - Privoxy executable. - - - - The installed defaults provide a reasonable starting point, though - some settings may be aggressive by some standards. For the time being, the - principle configuration files are: - - - - - - - - The main configuration file is named config - on Linux, Unix, BSD, OS/2, and AmigaOS and config.txt - on Windows. This is a required file. - - - - - - match-all.action is used to define which actions - relating to banner-blocking, images, pop-ups, content modification, cookie handling - etc should be applied by default. It should be the first actions file loaded. - - - default.action defines many exceptions (both positive and negative) - from the default set of actions that's configured in match-all.action. - It should be the second actions file loaded and shouldn't be edited by the user. - - - Multiple actions files may be defined in config. These - are processed in the order they are defined. Local customizations and locally - preferred exceptions to the default policies as defined in - match-all.action (which you will most probably want - to define sooner or later) are best applied in user.action, - where you can preserve them across upgrades. The file isn't installed by all - installers, but you can easily create it yourself with a text editor. - - - There is also a web based editor that can be accessed from - http://config.privoxy.org/show-status - (Shortcut: http://p.p/show-status) for the - various actions files. - - - - - - Filter files (the filter - file) can be used to re-write the raw page content, including - viewable text as well as embedded HTML and JavaScript, and whatever else - lurks on any given web page. The filtering jobs are only pre-defined here; - whether to apply them or not is up to the actions files. - default.filter includes various filters made - available for use by the developers. Some are much more intrusive than - others, and all should be used with caution. You may define additional - filter files in config as you can with - actions files. We suggest user.filter for any - locally defined filters or customizations. - - - - - - - - The syntax of the configuration and filter files may change between different - Privoxy versions, unfortunately some enhancements cost backwards compatibility. - - - - - All files use the # character to denote a - comment (the rest of the line will be ignored) and understand line continuation - through placing a backslash ("\") as the very last character - in a line. If the # is preceded by a backslash, it looses - its special function. Placing a # in front of an otherwise - valid configuration line to prevent it from being interpreted is called "commenting - out" that line. Blank lines are ignored. - - - - The actions files and filter files - can use Perl style regular expressions for - maximum flexibility. - - - - After making any changes, there is no need to restart - Privoxy in order for the changes to take - effect. Privoxy detects such changes - automatically. Note, however, that it may take one or two additional - requests for the change to take effect. When changing the listening address - of Privoxy, these wake up requests - must obviously be sent to the old listening address. - - - - While under development, the configuration content is subject to change. - The below documentation may not be accurate by the time you read this. - Also, what constitutes a default setting, may change, so - please check all your configuration files on important issues. - -]]> - - - - - - - - - - - - &config; - - - - - - - - - -Actions Files - - - - - The actions files are used to define what actions - Privoxy takes for which URLs, and thus determines - how ad images, cookies and various other aspects of HTTP content and - transactions are handled, and on which sites (or even parts thereof). - There are a number of such actions, with a wide range of functionality. - Each action does something a little different. - These actions give us a veritable arsenal of tools with which to exert - our control, preferences and independence. Actions can be combined so that - their effects are aggregated when applied against a given set of URLs. - - - There - are three action files included with Privoxy with - differing purposes: - - - - - - match-all.action - is used to define which - actions relating to banner-blocking, images, pop-ups, - content modification, cookie handling etc should be applied by default. - It should be the first actions file loaded - - - - - default.action - defines many exceptions (both - positive and negative) from the default set of actions that's configured - in match-all.action. It is a set of rules that should - work reasonably well as-is for most users. This file is only supposed to - be edited by the developers. It should be the second actions file loaded. - - - - - user.action - is intended to be for local site - preferences and exceptions. As an example, if your ISP or your bank - has specific requirements, and need special handling, this kind of - thing should go here. This file will not be upgraded. - - - - - Edit Set to Cautious Set to Medium Set to Advanced - - - These have increasing levels of aggressiveness and have no - influence on your browsing unless you select them explicitly in the - editor. A default installation should be pre-set to - Cautious. New users should try this for a while before - adjusting the settings to more aggressive levels. The more aggressive - the settings, then the more likelihood there is of problems such as sites - not working as they should. - - - The Edit button allows you to turn each - action on/off individually for fine-tuning. The Cautious - button changes the actions list to low/safe settings which will activate - ad blocking and a minimal set of &my-app;'s features, and subsequently - there will be less of a chance for accidental problems. The - Medium button sets the list to a medium level of - other features and a low level set of privacy features. The - Advanced button sets the list to a high level of - ad blocking and medium level of privacy. See the chart below. The latter - three buttons over-ride any changes via with the - Edit button. More fine-tuning can be done in the - lower sections of this internal page. - - - While the actions file editor allows to enable these settings in all - actions files, they are only supposed to be enabled in the first one - to make sure you don't unintentionally overrule earlier rules. - - - The default profiles, and their associated actions, as pre-defined in - default.action are: - - - Default Configurations - - - - - - - - Feature - Cautious - Medium - Advanced - - - - - - - - - - - - - - Ad-blocking Aggressiveness - medium - high - high - - - - Ad-filtering by size - no - yes - yes - - - - Ad-filtering by link - no - no - yes - - - Pop-up killing - blocks only - blocks only - blocks only - - - - Privacy Features - low - medium - medium/high - - - - Cookie handling - none - session-only - kill - - - - Referer forging - no - yes - yes - - - - GIF de-animation - no - yes - yes - - - - Fast redirects - no - no - yes - - - - HTML taming - no - no - yes - - - - JavaScript taming - no - no - yes - - - - Web-bug killing - no - yes - yes - - - - Image tag reordering - no - yes - yes - - - - -
- - - - - - - - The list of actions files to be used are defined in the main configuration - file, and are processed in the order they are defined (e.g. - default.action is typically processed before - user.action). The content of these can all be viewed and - edited from http://config.privoxy.org/show-status. - The over-riding principle when applying actions, is that the last action that - matches a given URL wins. The broadest, most general rules go first - (defined in default.action), - followed by any exceptions (typically also in - default.action), which are then followed lastly by any - local preferences (typically in user.action). - Generally, user.action has the last word. - - - - An actions file typically has multiple sections. If you want to use - aliases in an actions file, you have to place the (optional) - alias section at the top of that file. - Then comes the default set of rules which will apply universally to all - sites and pages (be very careful with using such a - universal set in user.action or any other actions file after - default.action, because it will override the result - from consulting any previous file). And then below that, - exceptions to the defined universal policies. You can regard - user.action as an appendix to default.action, - with the advantage that it is a separate file, which makes preserving your - personal settings across Privoxy upgrades easier. - - - - Actions can be used to block anything you want, including ads, banners, or - just some obnoxious URL whose content you would rather not see. Cookies can be accepted - or rejected, or accepted only during the current browser session (i.e. not - written to disk), content can be modified, some JavaScripts tamed, user-tracking - fooled, and much more. See below for a complete list - of actions. - - - - -Finding the Right Mix - - Note that some actions, like cookie suppression - or script disabling, may render some sites unusable that rely on these - techniques to work properly. Finding the right mix of actions is not always easy and - certainly a matter of personal taste. And, things can always change, requiring - refinements in the configuration. In general, it can be said that the more - aggressive your default settings (in the top section of the - actions file) are, the more exceptions for trusted sites you - will have to make later. If, for example, you want to crunch all cookies per - default, you'll have to make exceptions from that rule for sites that you - regularly use and that require cookies for actually useful purposes, like maybe - your bank, favorite shop, or newspaper. - - - - We have tried to provide you with reasonable rules to start from in the - distribution actions files. But there is no general rule of thumb on these - things. There just are too many variables, and sites are constantly changing. - Sooner or later you will want to change the rules (and read this chapter again :). - - - - - -How to Edit - - The easiest way to edit the actions files is with a browser by - using our browser-based editor, which can be reached from http://config.privoxy.org/show-status. - Note: the config file option enable-edit-actions must be enabled for - this to work. The editor allows both fine-grained control over every single - feature on a per-URL basis, and easy choosing from wholesale sets of defaults - like Cautious, Medium or - Advanced. Warning: the Advanced setting is more - aggressive, and will be more likely to cause problems for some sites. - Experienced users only! - - - - If you prefer plain text editing to GUIs, you can of course also directly edit the - the actions files with your favorite text editor. Look at - default.action which is richly commented with many - good examples. - - - - - -How Actions are Applied to Requests - - Actions files are divided into sections. There are special sections, - like the alias sections which will - be discussed later. For now let's concentrate on regular sections: They have a - heading line (often split up to multiple lines for readability) which consist - of a list of actions, separated by whitespace and enclosed in curly braces. - Below that, there is a list of URL and tag patterns, each on a separate line. - - - - To determine which actions apply to a request, the URL of the request is - compared to all URL patterns in each action file. - Every time it matches, the list of applicable actions for the request is - incrementally updated, using the heading of the section in which the - pattern is located. The same is done again for tags and tag patterns later on. - - - - If multiple applying sections set the same action differently, - the last match wins. If not, the effects are aggregated. - E.g. a URL might match a regular section with a heading line of { - +handle-as-image }, - then later another one with just { - +block }, resulting - in both actions to apply. And there may well be - cases where you will want to combine actions together. Such a section then - might look like: - - - - - { +handle-as-image +block{Banner ads.} } - # Block these as if they were images. Send no block page. - banners.example.com - media.example.com/.*banners - .example.com/images/ads/ - - - - You can trace this process for URL patterns and any given URL by visiting http://config.privoxy.org/show-url-info. - - - - Examples and more detail on this is provided in the Appendix, - Troubleshooting: Anatomy of an Action section. - - - - - -Patterns - - As mentioned, Privoxy uses patterns - to determine what actions might apply to which sites and - pages your browser attempts to access. These patterns use wild - card type pattern matching to achieve a high degree of - flexibility. This allows one expression to be expanded and potentially match - against many similar patterns. - - - - Generally, an URL pattern has the form - <domain><port>/<path>, where the - <domain>, 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, - 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, - it has to be put into angle brackets - (<, >). - - - - - www.example.com/ - - - is a domain-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. - - - - - www.example.com - - - means exactly the same. For domain-only patterns, the trailing / may - be omitted. - - - - - www.example.com/index.html - - - matches all the documents on www.example.com - whose name starts with /index.html. - - - - - www.example.com/index.html$ - - - matches only the single document /index.html - on www.example.com. - - - - - /index.html$ - - - matches the document /index.html, regardless of the domain, - i.e. on any web server anywhere. - - - - - :8000/ - - - Matches any URL pointing to TCP port 8000. - - - - - <2001:db8::1>/ - - - Matches any URL with the host address 2001:db8::1. - (Note that the real URL uses plain brackets, not angle brackets.) - - - - - index.html - - - matches nothing, since it would be interpreted as a domain name and - there is no top-level domain called .html. So its - a mistake. - - - - - - - -The Domain 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. - For example: - - - - - .example.com - - - matches any domain with first-level domain com - and second-level domain example. - For example www.example.com, - example.com and foo.bar.baz.example.com. - Note that it wouldn't match if the second-level domain was another-example. - - - - - www. - - - matches any domain that STARTS with - www. (It also matches the domain - www but most of the time that doesn't matter.) - - - - - .example. - - - matches any domain that CONTAINS .example.. - And, by the way, also included would be any files or documents that exist - within that domain since no path limitations are specified. (Correctly - speaking: It matches any FQDN that contains example as - a domain.) This might be www.example.com, - news.example.de, or - www.example.net/cgi/testing.pl for instance. All these - cases are matched. - - - - - - - Additionally, there are wild-cards that you can use in the domain names - themselves. These work similarly to shell globbing type wild-cards: - * represents zero or more arbitrary characters (this is - equivalent to the - Regular - Expression based syntax of .*), - ? represents any single character (this is equivalent to the - regular expression syntax of a simple .), and you can define - character classes in square brackets which is similar to - the same regular expression technique. All of this can be freely mixed: - - - - - ad*.example.com - - - matches adserver.example.com, - ads.example.com, etc but not sfads.example.com - - - - - *ad*.example.com - - - matches all of the above, and then some. - - - - - .?pix.com - - - matches www.ipix.com, - pictures.epix.com, a.b.c.d.e.upix.com etc. - - - - - www[1-9a-ez].example.c* - - - matches www1.example.com, - www4.example.cc, wwwd.example.cy, - wwwz.example.com etc., but not - wwww.example.com. - - - - - - - While flexible, this is not the sophistication of full regular expression based syntax. - - - - - - - - -The Path Pattern - - - Privoxy uses modern POSIX 1003.2 - Regular - Expressions for matching the path portion (after the slash), - and is thus more flexible. - - - - There is an Appendix with a brief quick-start into regular - expressions, you also might want to have a look at your operating system's documentation - on regular expressions (try man re_format). - - - - Note that the path pattern is automatically left-anchored at the /, - i.e. it matches as if it would start with a ^ (regular expression speak - for the beginning of a line). - - - - Please also note that matching in the path is CASE INSENSITIVE - by default, but you can switch to case sensitive at any point in the pattern by using the - (?-i) switch: www.example.com/(?-i)PaTtErN.* will match - only documents whose path starts with PaTtErN in - exactly this capitalization. - - - - - .example.com/.* - - - Is equivalent to just .example.com, since any documents - within that domain are matched with or without the .* - regular expression. This is redundant - - - - - .example.com/.*/index.html$ - - - Will match any page in the domain of example.com that is - named index.html, and that is part of some path. For - example, it matches www.example.com/testing/index.html but - NOT www.example.com/index.html because the regular - expression called for at least two /'s, thus the path - requirement. It also would match - www.example.com/testing/index_html, because of the - special meta-character .. - - - - - .example.com/(.*/)?index\.html$ - - - This regular expression is conditional so it will match any page - named index.html regardless of path which in this case can - have one or more /'s. And this one must contain exactly - .html (but does not have to end with that!). - - - - - .example.com/(.*/)(ads|banners?|junk) - - - This regular expression will match any path of example.com - that contains any of the words ads, banner, - banners (because of the ?) or junk. - The path does not have to end in these words, just contain them. - - - - - .example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$ - - - This is very much the same as above, except now it must end in either - .jpg, .jpeg, .gif or .png. So this - one is limited to common image formats. - - - - - - - There are many, many good examples to be found in default.action, - and more tutorials below in Appendix on regular expressions. - - - - - - - - -The Tag Pattern - - - Tag patterns are used to change the applying actions based on the - request's tags. Tags can be created with either the - client-header-tagger - or the server-header-tagger action. - - - - Tag patterns have to start with TAG:, so &my-app; - can tell them apart from URL patterns. Everything after the colon - including white space, is interpreted as a regular expression with - path pattern syntax, except that tag patterns aren't left-anchored - automatically (&my-app; doesn't silently add a ^, - you have to do it yourself if you need it). - - - - To match all requests that are tagged with foo - your pattern line should be TAG:^foo$, - TAG:foo would work as well, but it would also - match requests whose tags contain foo somewhere. - TAG: foo wouldn't work as it requires white space. - - - - Sections can contain URL and tag patterns at the same time, - but tag patterns are checked after the URL patterns and thus - always overrule them, even if they are located before the URL patterns. - - - - Once a new tag is added, Privoxy checks right away if it's matched by one - of the tag patterns and updates the action settings accordingly. As a result - tags can be used to activate other tagger actions, as long as these other - taggers look for headers that haven't already be parsed. - - - - For example you could tag client requests which use the - POST method, - then use this tag to activate another tagger that adds a tag if cookies - are sent, and then use a block action based on the cookie tag. This allows - the outcome of one action, to be input into a subsequent action. However if - you'd reverse the position of the described taggers, and activated the - method tagger based on the cookie tagger, no method tags would be created. - The method tagger would look for the request line, but at the time - the cookie tag is created, the request line has already been parsed. - - - - While this is a limitation you should be aware of, this kind of - indirection is seldom needed anyway and even the example doesn't - make too much sense. - - - - - - - - - - - - -Actions - - All actions are disabled by default, until they are explicitly enabled - somewhere in an actions file. Actions are turned on if preceded with a - +, and turned off if preceded with a -. So a - +action means do that action, e.g. - +block means please block URLs that match the - following patterns, and -block means don't - block URLs that match the following patterns, even if +block - previously applied. - - - - - Again, actions are invoked by placing them on a line, enclosed in curly braces and - separated by whitespace, like in - {+some-action -some-other-action{some-parameter}}, - followed by a list of URL patterns, one per line, to which they apply. - Together, the actions line and the following pattern lines make up a section - of the actions file. - - - - Actions fall into three categories: - - - - - - - Boolean, i.e the action can only be enabled or - disabled. Syntax: - - - - +name # enable action name - -name # disable action name - - - Example: +handle-as-image - - - - - - - Parameterized, where some value is required in order to enable this type of action. - Syntax: - - - - +name{param} # enable action and set parameter to param, - # overwriting parameter from previous match if necessary - -name # disable action. The parameter can be omitted - - - Note that if the URL matches multiple positive forms of a parameterized action, - the last match wins, i.e. the params from earlier matches are simply ignored. - - - Example: +hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4} - - - - - - Multi-value. These look exactly like parameterized actions, - but they behave differently: If the action applies multiple times to the - same URL, but with different parameters, all the parameters - from all matches are remembered. This is used for actions - that can be executed for the same request repeatedly, like adding multiple - headers, or filtering through multiple filters. Syntax: - - - - +name{param} # enable action and add param to the list of parameters - -name{param} # remove the parameter param from the list of parameters - # If it was the last one left, disable the action. - -name # disable this action completely and remove all parameters from the list - - - Examples: +add-header{X-Fun-Header: Some text} and - +filter{html-annoyances} - - - - - - - - If nothing is specified in any actions file, no actions are - taken. So in this case Privoxy would just be a - normal, non-blocking, non-filtering proxy. You must specifically enable the - privacy and blocking features you need (although the provided default actions - files will give a good starting point). - - - - Later defined action sections always over-ride earlier ones of the same type. - So exceptions to any rules you make, should come in the latter part of the file (or - in a file that is processed later when using multiple actions files such - as user.action). For multi-valued actions, the actions - are applied in the order they are specified. Actions files are processed in - the order they are defined in config (the default - installation has three actions files). It also quite possible for any given - URL to match more than one pattern (because of wildcards and - regular expressions), and thus to trigger more than one set of actions! Last - match wins. - - - - - The list of valid Privoxy actions are: - - - - - - - - - - - - - -add-header - - - - Typical use: - - Confuse log analysis, custom applications - - - - - Effect: - - - Sends a user defined HTTP header to the web server. - - - - - - Type: - - - Multi-value. - - - - - Parameter: - - - Any string value is possible. Validity of the defined HTTP headers is not checked. - It is recommended that you use the X- prefix - for custom headers. + General improvements: + + + + Privoxy can (re)compress buffered content before delivering + it to the client. Disabled by default as most users wouldn't + benefit from it. + + + + + The +fast-redirects{check-decoded-url} action checks URL + segments separately. If there are other parameters behind + the redirect URL, this makes it unnecessary to cut them off + by additionally using a +redirect{} pcrs command. + Initial patch submitted by Jamie Zawinski in #3429848. + + + + + When loading action sections, verify that the referenced filters + exist. Currently missing filters only result in an error message, + but eventually the severity will be upgraded to fatal. + + + + + Allow to bind to multiple separate addresses. + Patch set submitted by Petr Pisar in #3354485. + + + + + Set socket_error to errno if connecting fails in rfc2553_connect_to(). + Previously rejected direct connections could be incorrectly reported + as DNS issues if Privoxy was compiled with IPv6 support. + + + + + Adjust url_code_map[] so spaces are replaced with %20 instead of '+' + While '+' can be used by client's submitting form data, this is not + actually what Privoxy is using the lookups for. This is more of a + cosmetic issue and doesn't fix any known problems. + + + + + When compiled without FEATURE_FAST_REDIRECTS, do not silently + ignore +fast-redirect{} directives + + + + + Added a workaround for GNU libc's strptime() reporting negative + year values when the parsed year is only specified with two digits. + On affected systems cookies with such a date would not be turned + into session cookies by the +session-cookies-only action. + Reported by Vaeinoe in #3403560 + + + + + Fixed bind failures with certain GNU libc versions if no non-loopback + IP address has been configured on the system. This is mainly an issue + if the system is using DHCP and Privoxy is started before the network + is completely configured. + Reported by Raphael Marichez in #3349356. + Additional insight from Petr Pisar. + + + + + Privoxy log messages now use the ISO 8601 date format %Y-%m-%d. + It's only slightly longer than the old format, but contains + the full date including the year and allows sorting by date + (when grepping in multiple log files) without hassle. + + + + + In get_last_url(), do not bother trying to decode URLs that do + not contain at least one '%' sign. It reduces the log noise and + a number of unnecessary memory allocations. + + + + + In case of SOCKS5 failures, dump the socks response in the log message. + + + + + Simplify the signal setup in main(). + + + + + Streamline socks5_connect() slightly. + + + + + In socks5_connect(), require a complete socks response from the server. + Previously Privoxy didn't care how much data the server response + contained as long as the first two bytes contained the expected + values. While at it, shrink the buffer size so Privoxy can't read + more than a whole socks response. + + + + + In chat(), do not bother to generate a client request in case of + direct CONNECT requests. It will not be used anyway. + + + + + Reduce server_last_modified()'s stack size. + + + + + Shorten get_http_time() by using strftime(). + + + + + Constify the known_http_methods pointers in unknown_method(). + + + + + Constify the time_formats pointers in parse_header_time(). + + + + + Constify the formerly_valid_actions pointers in action_used_to_be_valid(). + + + + + Introduce a GNUMakefile MAN_PAGE variable that defaults to privoxy.1. + The Debian package uses section 8 for the man page and this + should simplify the patch. + + + + + Deduplicate the INADDR_NONE definition for Solaris by moving it to jbsockets.h + + + + + In block_url(), ditch the obsolete workaround for ancient Netscape versions + that supposedly couldn't properly deal with status code 403. + + + + + Remove a useless NULL pointer check in load_trustfile(). + + + + + Remove two useless NULL pointer checks in load_one_re_filterfile(). + + + + + Change url_code_map[] from an array of pointers to an array of arrays + It removes an unnecessary layer of indirection and on 64bit system reduces + the size of the binary a bit. + + + + + Fix various typos. Fixes taken from Debian's 29_typos.dpatch by Roland Rosenfeld. + + + + + Add a dok-tidy GNUMakefile target to clean up the messy HTML + generated by the other dok targets. + + + + + GNUisms in the GNUMakefile have been removed. + + + + + Change the HTTP version in static responses to 1.1 + + + + + Synced config.sub and config.guess with upstream + 2011-11-11/386c7218162c145f5f9e1ff7f558a3fbb66c37c5. + + + + + Add a dedicated function to parse the values of toggles. Reduces duplicated + code in load_config() and provides better error handling. Invalid or missing + toggle values are now a fatal error instead of being silently ignored. + + + + + Terminate HTML lines in static error messages with \n instead of \r\n. + + + + + Simplify cgi_error_unknown() a bit. + + + + + In LogPutString(), don't bother looking at pszText when not + actually logging anything. + + + + + Change ssplit()'s fourth parameter from int to size_t. + Fixes a clang complaint. + + + + + Add a warning that the statistics currently can't be trusted. + Mention Privoxy-Log-Parser's --statistics option as + an alternative for the time being. + + + + + In rfc2553_connect_to(), start setting cgi->error_message on error. + + + + + Change the expected status code returned for http://p.p/die depending + on whether or not FEATURE_GRACEFUL_TERMINATION is available. + + + + + In cgi_die(), mark the client connection for closing. + If the client will fetch the style sheet through another connection + it gets the main thread out of the accept() state and should thus + trigger the actual shutdown. + + + + + Add a proper CGI message for cgi_die(). + + + + + Don't enforce a logical line length limit in read_config_line(). + + + + + Slightly refactor server_last_modified() to remove useless gmtime*() calls. + + + + + In get_content_type(), also recognize '.jpeg' as JPEG extension. + + + + + Add '.png' to the list of recognized file extensions in get_content_type(). + + + + + In block_url(), consistently use the block reason "Request blocked by Privoxy" + In two places the reason was "Request for blocked URL" which hides the + fact that the request got blocked by Privoxy and isn't necessarily + correct as the block may be due to tags. + + + + + In listen_loop(), reload the configuration files after accepting + a new connection instead of before. + Previously the first connection that arrived after a configuration + change would still be handled with the old configuration. + + + + + In chat()'s receive-data loop, skip a client socket check if + the socket will be written to right away anyway. This can + increase the transfer speed for unfiltered content on fast + network connections. + + + + + The socket timeout is used for SOCKS negotiations as well which + previously couldn't timeout. + + + + + Don't keep the client connection alive if any configuration file + changed since the time the connection came in. This is closer to + Privoxy's behaviour before keep-alive support for client connection + has been added and also less confusing in general. + + + + + Treat all Content-Type header values containing the pattern + 'script' as a sign of text. Reported by pribog in #3134970. + + + - - - - Notes: - This action may be specified multiple times, in order to define multiple - headers. This is rarely needed for the typical user. If you don't know what - HTTP headers are, you definitely don't need to worry about this - one. - - - Headers added by this action are not modified by other actions. + Action file improvements: + + + + Moved the site-specific block pattern section below the one for the + generic patterns so for requests that are matched in both, the block + reason for the domain is shown which is usually more useful than showing + the one for the generic pattern. + + + + + Remove -prevent-compression from the fragile alias. It's no longer + used anywhere by default and isn't known to break stuff anyway. + + + + + Add a (disabled) section to block various Facebook tracking URLs. + Reported by Dan Stahlke in #3421764. + + + + + Add a (disabled) section to rewrite and redirect click-tracking + URLs used on news.google.com. + Reported by Dan Stahlke in #3421755. + + + + + Unblock linuxcounter.net/. + Reported by Dan Stahlke in #3422612. + + + + + Block 'www91.intel.com/' which is used by Omniture. + Reported by Adam Piggott in #3167370. + + + + + Disable the handle-as-empty-doc-returns-ok option and mark it as deprecated. + Reminded by tceverling in #2790091. + + + + + Add ".ivwbox.de/" to the "Cross-site user tracking" section. + Reported by Nettozahler in #3172525. + + + + + Unblock and fast-redirect ".awin1.com/.*=http://". + Reported by Adam Piggott in #3170921. + + + + + Block "b.collective-media.net/". + + + + + Widen the Debian popcon exception to "qa.debian.org/popcon". + Seen in Debian's 05_default_action.dpatch by Roland Rosenfeld. + + + + + Block ".gemius.pl/" which only seems to be used for user tracking. + Reported by johnd16 in #3002731. Additional input from Lee and movax. + + + + + Disable banners-by-size filters for '.thinkgeek.com/'. + The filter only seems to catch pictures of the inventory. + + + + + Block requests for 'go.idmnet.bbelements.com/please/showit/'. + Reported by kacperdominik in #3372959. + + + + + Unblock adainitiative.org/. + + + + + Add a fast-redirects exception for '.googleusercontent.com/.*=cache'. + + + + + Add a fast-redirects exception for webcache.googleusercontent.com/. + + + + + Unblock http://adassier.wordpress.com/ and http://adassier.files.wordpress.com/. + + + - - - - Example usage: - - +add-header{X-User-Tracking: sucks} + + Filter file improvements: + + + + Let the yahoo filter hide '.ads'. + + + + + Let the msn filter hide overlay ads for Facebook 'likes' in search + results and elements with the id 's_notf_div'. They only seem to be + used to advertise site 'enhancements'. + + + + + Let the js-events filter additionally disarm setInterval(). + Suggested by dg1727 in #3423775. + + + - - - - - - - -block - - - - Typical use: - - Block ads or other unwanted content - - - - - Effect: - Requests for URLs to which this action applies are blocked, i.e. the - requests are trapped by &my-app; and the requested URL is never retrieved, - but is answered locally with a substitute page or image, as determined by - the handle-as-image, - set-image-blocker, and - handle-as-empty-document actions. - + Documentation improvements: + + + + Clarify the effect of compiling Privoxy with zlib support. + Suggested by dg1727 in #3423782. + + + + + Point out that the SourceForge messaging system works like a black + hole and should thus not be used to contact individual developers. + + + + + Mention some of the problems one can experience when not explicitly + configuring an IP addresses as listen address. + + + + + Explicitly mention that hostnames can be used instead of IP addresses + for the listen-address, that only the first address returned will be + used and what happens if the address is invalid. + Requested by Calestyo in #3302213. + + + - - - - Type: - - - Parameterized. - - - - - Parameter: - - A block reason that should be given to the user. - - - - - Notes: - Privoxy sends a special BLOCKED page - for requests to blocked pages. This page contains the block reason given as - parameter, a link to find out why the block action applies, and a click-through - to the blocked content (the latter only if the force feature is available and - enabled). - - - A very important exception occurs if both - block and handle-as-image, - apply to the same request: it will then be replaced by an image. If - set-image-blocker - (see below) also applies, the type of image will be determined by its parameter, - if not, the standard checkerboard pattern is sent. - - - It is important to understand this process, in order - to understand how Privoxy deals with - ads and other unwanted content. Blocking is a core feature, and one - upon which various other features depend. - - - The filter - action can perform a very similar task, by blocking - banner images and other content through rewriting the relevant URLs in the - document's HTML source, so they don't get requested in the first place. - Note that this is a totally different technique, and it's easy to confuse the two. + Log message improvements: + + + + If only the server connection is kept alive, do not pretend to + wait for a new client request. + + + + + Remove a superfluous log message in forget_connection(). + + + + + In chat(), properly report missing server responses as such + instead of calling them empty. + + + + + In forwarded_connect(), fix a log message nobody should ever see. + + + + + Fix a log message in socks5_connect(), a failed write operation + was logged as failed read operation. + + + + + Let load_one_actions_file() properly complain about a missing + '{' at the beginning of the file. + Simply stating that a line is invalid isn't particularly helpful. + + + + + Do not claim to listen on a socket until Privoxy actually does. + Patch submitted by Petr Pisar #3354485 + + + + + Prevent a duplicated LOG_LEVEL_CLF message when sending out + the "no-server-data" response. + + + + + Also log the client socket when dropping a connection. + + + + + Include the destination host in the 'Request ... marked for + blocking. limit-connect{...} doesn't allow CONNECT ...' message + Patch submitted by Saperski in #3296250. + + + + + Prevent a duplicated log message if none of the resolved IP + addresses were reachable. + + + + + In connect_to(), do not pretend to retry if forwarded-connect-retries + is zero or unset. + + + + + When a specified user or group can't be found, put the name in + single-quotes when logging it. + + + + + In rfc2553_connect_to(), explain getnameinfo() errors better. + + + + + Remove a useless log message in chat(). + + + + + When retrying to connect, also log the maximum number of connection + attempts. + + + + + Rephrase a log message in compile_dynamic_pcrs_job_list(). + Divide the error code and its meaning with a colon. Call the pcrs + job dynamic and not the filter. Filters may contain dynamic and + non-dynamic pcrs jobs at the same time. Only mention the name of + the filter or tagger, but don't claim it's a filter when it could + be a tagger. + + + + + In a fatal error message in load_one_actions_file(), cover both + URL and TAG patterns. + + + + + In pcrs_strerror(), properly report unknown positive error code + values as such. Previously they were handled like 0 (no error). + + + + + In compile_dynamic_pcrs_job_list(), also log the actual error code as + pcrs_strerror() doesn't handle all errors reported by pcre. + + + + + Don't bother trying to continue chatting if the client didn't ask for it. + Reduces log noise a bit. + + + + + Make two fatal error message in load_one_actions_file() more descriptive. + + + + + In cgi_send_user_manual(), log when rejecting a file name due to '/' or '..'. + + + + + In load_file(), log a message if opening a file failed. + The CGI error message alone isn't too helpful. + + + + + In connection_destination_matches(), improve two log messages + to help understand why the destinations don't match. + + + + + Rephrase a log message in serve(). Client request arrival + should be differentiated from closed client connections now. + + + + + In serve(), log if a client connection isn't reused due to a + configuration file change. + + + + + Let mark_server_socket_tainted() always mark the server socket tainted, + just don't talk about it in cases where it has no effect. It doesn't change + Privoxy's behaviour, but makes understanding the log file easier. + + + - - - - Example usage (section): - - - {+block{No nasty stuff for you.}} -# Block and replace with "blocked" page - .nasty-stuff.example.com - -{+block{Doubleclick banners.} +handle-as-image} -# Block and replace with image - .ad.doubleclick.net - .ads.r.us/banners/ - -{+block{Layered ads.} +handle-as-empty-document} -# Block and then ignore - adserver.example.net/.*\.js$ - - - - - - - - - - - -change-x-forwarded-for - - - - Typical use: - - Improve privacy by not forwarding the source of the request in the HTTP headers. - - - - - Effect: - Deletes the X-Forwarded-For: HTTP header from the client request, - or adds a new one. + configure: + + + + Added a --disable-ipv6-support switch for platforms where support + is detected but doesn't actually work. + + + + + Do not check for the existence of strerror() and memmove() twice + + + + + Remove a useless test for setpgrp(2). Privoxy doesn't need it and + it can cause problems when cross-compiling. + + + + + Rename the --disable-acl-files switch to --disable-acl-support. + Since about 2001, ACL directives are specified in the standard + config file. + + + + + Update the URL of the 'Removing outdated PCRE version after the + next stable release' posting. The old URL stopped working after + one of SF's recent site "optimizations". Reported by Han Liu. + + + - - - - Type: - - - Parameterized. - - - - - Parameter: - + + Privoxy-Regression-Test: + - block to delete the header. + + Added --shuffle-tests option to increase the chances of detection race conditions. + - add to create the header (or append - the client's IP address to an already existing one). + Added a --local-test-file option that allows to use Privoxy-Regression-Test without Privoxy. - + + + Added tests for missing socks4 and socks4a forwarders. + + + + + The --privoxy-address option now works with IPv6 addresses containing brackets, too. + + + + + Perform limited sanity checks for parameters that are supposed to have numerical values. + + + + + Added a --sleep-time option to specify a number of seconds to + sleep between tests, defaults to 0. + + + + + Disable the range-requests tagger for tests that break if it's enabled. + + + + + Log messages use the ISO 8601 date format %Y-%m-%d. + + + + + Fix spelling in two error messages. + + + + + In the --help output, include a list of supported tests and their default levels. + + + + + Adjust the tests to properly deal with FEATURE_TOGGLE being disabled. + + + + - - - - Notes: - It is safe and recommended to use block. - - - Forwarding the source address of the request may make - sense in some multi-user setups but is also a privacy risk. + Privoxy-Log-Parser: + + + + Perform limited sanity checks for command line parameters that + are supposed to have numerical values. + + + + + Implement a --unbreak-lines-only option to try to revert MUA breakage. + + + + + Accept and highlight: Added header: Content-Encoding: deflate + + + + + Accept and highlight: Compressed content from 29258 to 8630 bytes. + + + + + Accept and highlight: Client request arrived in time on socket 21. + + + + + Highlight: Didn't receive data in time: a.fsdn.com:443 + + + + + Accept log messages with ISO 8601 time stamps, too. + + + - - - Example usage: - - +change-x-forwarded-for{block} + + uagen: + + + + Bump generated Firefox version to 8.0. + + + + + Only randomize the release date if the new --randomize-release-date + option is enabled. Firefox versions after 4 use a fixed date string + without meaning. + + + - - - + + + - -client-header-filter - - - Typical use: - - - Rewrite or remove single client headers. - + +Note to Upgraders + + + A quick list of things to be aware of before upgrading from earlier + versions of 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. + + + + + 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. + - - - Effect: + + - - Parameterized. - - - - Parameter: - The name of a client-header filter, as defined in one of the - filter files. - - - - - - Notes: - - - Client-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. - - - Client-header filters are executed after the other header actions have finished - and use their output as input. + The default setting has filtering turned off, which + subsequently means that compression is on. Remember + that filtering does not work on compressed pages, so if you use, or want to + use, filtering, you will need to force compression off. Example: - If the request URL 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. + + { +filter{google} +prevent-compression } + .google. - Please refer to the filter file chapter - to learn which client-header filters are available by default, and how to - create your own. + Or if you use a number of filters, or filter many sites, you may just want + to turn off compression for all sites in + default.action (or + user.action). - - - Example usage (section): - - -# Hide Tor exit notation in Host and Referer Headers -{+client-header-filter{hide-tor-exit-notation}} -/ - - + + Also, session-cookies-only is + off by default now. If you've liked this feature in the past, you may want + to turn it back on in user.action now. + - - - + + + Some installers may not automatically start + Privoxy after installation. + + +--> + + + + + + - -client-header-tagger +Quickstart to Using Privoxy + + - - - Typical use: - - - Block requests based on their headers. - - - + + + Install Privoxy. See the Installation Section below for platform specific + information. + + - - Effect: - - - Client headers to which this action applies are filtered on-the-fly through - the specified regular expression based substitutions, the result is used as - tag. - - - + + + Advanced users and those who want to offer Privoxy + service to more than just their local machine should check the main config file, especially the security-relevant options. These are + off by default. + + - - Type: - - - Parameterized. - - + + + Start Privoxy, if the installation program has + not done this already (may vary according to platform). See the section + Starting Privoxy. + + - - Parameter: - - - The name of a client-header tagger, as defined in one of the - filter files. - - - - - - Notes: - - - Client-header taggers are applied to each header on its own, - and as the header isn't modified, each tagger sees - the original. - - - Client-header taggers are the first actions that are executed - and their tags can be used to control every other action. - + + + Set your browser to use Privoxy as HTTP and + HTTPS (SSL) proxy + by setting the proxy configuration for address of + 127.0.0.1 and port 8118. + DO NOT activate proxying for FTP or + any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your + browser from using these protocols. + - - - Example usage (section): - - - -# Tag every request with the User-Agent header -{+client-header-tagger{user-agent}} -/ + + + Flush your browser's disk and memory caches, to remove any cached ad images. + If using Privoxy to manage + cookies, + you should remove any currently stored cookies too. + + + + + + A default installation should provide a reasonable starting point for + most. There will undoubtedly be occasions where you will want to adjust the + configuration, but that can be dealt with as the need arises. Little + to no initial configuration is required in most cases, you may want + to enable the + web-based action editor though. + Be sure to read the warnings first. + + + See the Configuration section for more + configuration options, and how to customize your installation. + You might also want to look at the next section for a quick + introduction to how Privoxy blocks ads and + banners. + + + + + + If you experience ads that slip through, innocent images that are + blocked, or otherwise feel the need to fine-tune + Privoxy's behavior, take a look at the actions files. As a quick start, you might + find the richly commented examples + helpful. You can also view and edit the actions files through the web-based user interface. The + Appendix Troubleshooting: Anatomy of an + Action has hints on how to understand and debug actions that + misbehave. + + + + + + + + Please see the section Contacting the + Developers on how to report bugs, problems with websites or to get + help. + + -# Tagging itself doesn't change the action -# settings, sections with TAG patterns do: -# -# If it's a download agent, use a different forwarding proxy, -# show the real User-Agent and make sure resume works. -{+forward-override{forward-socks5 10.0.0.2:2222 .} \ - -hide-if-modified-since \ - -overwrite-last-modified \ - -hide-user-agent \ - -filter \ - -deanimate-gifs \ -} -TAG:^User-Agent: NetBSD-ftp/ -TAG:^User-Agent: Novell ZYPP Installer -TAG:^User-Agent: RPM APT-HTTP/ -TAG:^User-Agent: fetch libfetch/ -TAG:^User-Agent: Ubuntu APT-HTTP/ -TAG:^User-Agent: MPlayer/ - - - - + + + Now enjoy surfing with enhanced control, comfort and privacy! + + - - + + - -content-type-overwrite - - - Typical use: - - Stop useless download menus from popping up, or change the browser's rendering mode - - + +Quickstart to Ad Blocking + + + Ad blocking is but one of Privoxy's + array of features. Many of these features are for the technically minded advanced + user. But, ad and banner blocking is surely common ground for everybody. + + + This section will provide a quick summary of ad blocking so + you can get up to speed quickly without having to read the more extensive + information provided below, though this is highly recommended. + + + First a bit of a warning ... blocking ads is much like blocking SPAM: the + more aggressive you are about it, the more likely you are to block + things that were not intended. And the more likely that some things + may not work as intended. So there is a trade off here. If you want + extreme ad free browsing, be prepared to deal with more + problem sites, and to spend more time adjusting the + configuration to solve these unintended consequences. In short, there is + not an easy way to eliminate all ads. Either take + the easy way and settle for most ads blocked with the + default configuration, or jump in and tweak it for your personal surfing + habits and preferences. + + + Secondly, a brief explanation of Privoxy's + actions. Actions in this context, are + the directives we use to tell Privoxy to perform + some task relating to HTTP transactions (i.e. web browsing). We tell + Privoxy to take some action. Each + action has a unique name and function. While there are many potential + actions in Privoxy's + arsenal, only a few are used for ad blocking. Actions, and action + configuration files, are explained in depth below. + + + Actions are specified in Privoxy's configuration, + followed by one or more URLs to which the action should apply. URLs + can actually be URL type patterns that use + wildcards so they can apply potentially to a range of similar URLs. The + actions, together with the URL patterns are called a section. + + + When you connect to a website, the full URL will either match one or more + of the sections as defined in Privoxy's configuration, + or not. If so, then Privoxy will perform the + respective actions. If not, then nothing special happens. Furthermore, web + pages may contain embedded, secondary URLs that your web browser will + use to load additional components of the page, as it parses the + original page's HTML content. An ad image for instance, is just an URL + embedded in the page somewhere. The image itself may be on the same server, + or a server somewhere else on the Internet. Complex web pages will have many + such embedded URLs. &my-app; can deal with each URL individually, so, for + instance, the main page text is not touched, but images from such-and-such + server are blocked. + - - Effect: - - - Replaces the Content-Type: HTTP server header. - - - + + The most important actions for basic ad blocking are: block, handle-as-image, + handle-as-empty-document,and + set-image-blocker: + - - Type: - - - Parameterized. - - + + - - Parameter: - - - Any string. - - - - - - Notes: - - - The Content-Type: HTTP server header is used by the - browser to decide what to do with the document. The value of this - header can cause the browser to open a download menu instead of - displaying the document by itself, even if the document's format is - supported by the browser. - - - The declared content type can also affect which rendering mode - the browser chooses. If XHTML is delivered as text/html, - many browsers treat it as yet another broken HTML document. - If it is send as application/xml, browsers with - XHTML support will only display it, if the syntax is correct. - - - If you see a web site that proudly uses XHTML buttons, but sets - Content-Type: text/html, you can use &my-app; - to overwrite it with application/xml and validate - the web master's claim inside your XHTML-supporting browser. - If the syntax is incorrect, the browser will complain loudly. - - - You can also go the opposite direction: if your browser prints - error messages instead of rendering a document falsely declared - as XHTML, you can overwrite the content type with - text/html and have it rendered as broken HTML document. - - - By default content-type-overwrite only replaces - Content-Type: headers that look like some kind of text. - If you want to overwrite it unconditionally, you have to combine it with - force-text-mode. - This limitation exists for a reason, think twice before circumventing it. - - - Most of the time it's easier to replace this action with a custom - server-header filter. - It allows you to activate it for every document of a certain site and it will still - only replace the content types you aimed at. - - - Of course you can apply content-type-overwrite - to a whole site and then make URL based exceptions, but it's a lot - more work to get the same precision. - + + + block - this is perhaps + the single most used action, and is particularly important for ad blocking. + This action stops any contact between your browser and any URL patterns + that match this action's configuration. It can be used for blocking ads, + but also anything that is determined to be unwanted. By itself, it simply + stops any communication with the remote server and sends + Privoxy's own built-in BLOCKED page instead to + let you now what has happened (with some exceptions, see below). + + + + + + handle-as-image - + tells Privoxy to treat this URL as an image. + Privoxy's default configuration already does this + for all common image types (e.g. GIF), but there are many situations where this + is not so easy to determine. So we'll force it in these cases. This is particularly + important for ad blocking, since only if we know that it's an image of + some kind, can we replace it with an image of our choosing, instead of the + Privoxy BLOCKED page (which would only result in + a broken image icon). There are some limitations to this + though. For instance, you can't just brute-force an image substitution for + an entire HTML page in most situations. + + + + + + handle-as-empty-document - + sends an empty document instead of Privoxy's + normal BLOCKED HTML page. This is useful for file types that are neither + HTML nor images, such as blocking JavaScript files. + + + + + + set-image-blocker - tells + Privoxy what to display in place of an ad image that + has hit a block rule. For this to come into play, the URL must match a + block action somewhere in the + configuration, and, it must also match an + handle-as-image action. + + + The configuration options on what to display instead of the ad are: + + + +    pattern - a checkerboard pattern, so that an ad + replacement is obvious. This is the default. + + + + +    blank - A very small empty GIF image is displayed. + This is the so-called invisible configuration option. + + + + +    http://<URL> - A redirect to any image anywhere + of the user's choosing (advanced usage). + + - - - Example usage (sections): - - - # Check if www.example.net/ really uses valid XHTML -{ +content-type-overwrite{application/xml} } -www.example.net/ + + + + + Advanced users will eventually want to explore &my-app; + filters as well. Filters + are very different from blocks. + A block blocks a site, page, or unwanted contented. Filters + are a way of filtering or modifying what is actually on the page. An example + filter usage: a text replacement of no-no for + nasty-word. That is a very simple example. This process can be + used for ad blocking, but it is more in the realm of advanced usage and has + some pitfalls to be wary off. + + + + The quickest way to adjust any of these settings is with your browser through + the special Privoxy editor at http://config.privoxy.org/show-status + (shortcut: http://p.p/show-status). This + is an internal page, and does not require Internet access. + -# but leave the content type unmodified if the URL looks like a style sheet -{-content-type-overwrite} -www.example.net/.*\.css$ -www.example.net/.*style - - - - - - + + Note that as of Privoxy 3.0.7 beta the + action editor is disabled by default. Check the + enable-edit-actions + section in the configuration file to learn why and in which + cases it's safe to enable again. + + + If you decided to enable the action editor, select the appropriate + actions file, and click + Edit. It is best to put personal or + local preferences in user.action since this is not + meant to be overwritten during upgrades, and will over-ride the settings in + other files. Here you can insert new actions, and URLs for ad + blocking or other purposes, and make other adjustments to the configuration. + Privoxy will detect these changes automatically. + - - - -crunch-client-header + + A quick and simple step by step example: + - - - Typical use: - - Remove a client header Privoxy has no dedicated action for. - - + + - - Effect: - Deletes every header sent by the client that contains the string the user supplied as parameter. + Right click on the ad image to be blocked, then select + Copy Link Location from the + pop-up menu. - - - - Type: - - - Parameterized. - - - - - Parameter: - Any string. - + Set your browser to + http://config.privoxy.org/show-status + - - - - Notes: - This action allows you to block client headers for which no dedicated - Privoxy action exists. - Privoxy will remove every client header that - contains the string you supplied as parameter. - - - Regular expressions are not supported and you can't - use this action to block different headers in the same request, unless - they contain the same string. - - - crunch-client-header is only meant for quick tests. - If you have to block several different headers, or only want to modify - parts of them, you should use a - client-header filter. + Find user.action in the top section, and click + on Edit: - - - Don't block any header without understanding the consequences. - - - - - - Example usage (section): - - - # Block the non-existent "Privacy-Violation:" client header -{ +crunch-client-header{Privacy-Violation:} } -/ - - - - - - + + +
Actions Files in Use + + + + + + [ Screenshot of Actions Files in Use ] + + +
+ + + + + + You should have a section with only + block listed under + Actions:. + If not, click a Insert new section below + button, and in the new section that just appeared, click the + Edit button right under the word Actions:. + This will bring up a list of all actions. Find + block near the top, and click + in the Enabled column, then Submit + just below the list. + + + + + Now, in the block actions section, + click the Add button, and paste the URL the + browser got from Copy Link Location. + Remove the http:// at the beginning of the URL. Then, click + Submit (or + OK if in a pop-up window). + + + + + Now go back to the original page, and press SHIFT-Reload + (or flush all browser caches). The image should be gone now. + + + + - - -crunch-if-none-match - - - - Typical use: - - Prevent yet another way to track the user's steps between sessions. - - + + This is a very crude and simple example. There might be good reasons to use a + wildcard pattern match to include potentially similar images from the same + site. For a more extensive explanation of patterns, and + the entire actions concept, see the Actions + section. + - - Effect: - - - Deletes the If-None-Match: HTTP client header. - - - + + For advanced users who want to hand edit their config files, you might want + to now go to the Actions Files Tutorial. + The ideas explained therein also apply to the web-based editor. + + + There are also various + filters that can be used for ad blocking + (filters are a special subset of actions). These + fall into the advanced usage category, and are explained in + depth in later sections. + - - Type: - - - Boolean. - - + - - Parameter: - - - N/A - - - - - - Notes: - - - Removing the If-None-Match: HTTP client 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. - - - It is also useful to make sure the header isn't used as a cookie - replacement (unlikely but possible). - - - Blocking the If-None-Match: header shouldn't cause any - caching problems, as long as the If-Modified-Since: header - isn't blocked or missing as well. - - - It is recommended to use this action together with - hide-if-modified-since - and - overwrite-last-modified. - - - + + + + + + + +Starting Privoxy + + Before launching Privoxy for the first time, you + will want to configure your browser(s) to use + Privoxy as a HTTP and HTTPS (SSL) + proxy. The default is + 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions + used port 8000). This is the one configuration step that must be done +! + + + Please note that Privoxy can only proxy HTTP and + HTTPS traffic. It will not work with FTP or other protocols. + + + + +
Proxy Configuration Showing + Mozilla/Netscape HTTP and HTTPS (SSL) Settings + + + + + + [ Screenshot of Mozilla Proxy Configuration ] + + +
+ - - Example usage (section): - - - # Let the browser revalidate cached documents but don't -# allow the server to use the revalidation headers for user tracking. -{+hide-if-modified-since{-60} \ - +overwrite-last-modified{randomize} \ - +crunch-if-none-match} -/ - - - - - + + With Firefox, this is typically set under: + - - -crunch-incoming-cookies + + Tools -> Options -> Advanced -> Network ->Connection -> Settings - - - Typical use: - - - Prevent the web server from setting HTTP cookies on your system - - - + - - Effect: - - - Deletes any Set-Cookie: HTTP headers from server replies. - - - + + Or optionally on some platforms: + - - Type: - - - Boolean. - - + + Edit -> Preferences -> General -> Connection Settings -> Manual Proxy Configuration - - Parameter: - - - N/A - - - - - - Notes: - - - This action is only concerned with incoming HTTP cookies. For - outgoing HTTP cookies, use - crunch-outgoing-cookies. - Use both to disable HTTP cookies completely. - - - It makes no sense at all to use this action in conjunction - with the session-cookies-only action, - since it would prevent the session cookies from being set. See also - filter-content-cookies. - - - + - - Example usage: - - - +crunch-incoming-cookies - - - - - + + With Netscape (and + Mozilla), this can be set under: + - - -crunch-server-header - - - - Typical use: - - Remove a server header Privoxy has no dedicated action for. - - - - Effect: - - - Deletes every header sent by the server that contains the string the user supplied as parameter. - - - + + + + Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy - - Type: - - - Parameterized. - - + - - Parameter: - - - Any string. - - - - - - Notes: - - - This action allows you to block server headers for which no dedicated - Privoxy action exists. Privoxy - will remove every server header that contains the string you supplied as parameter. - - - Regular expressions are not supported and you can't - use this action to block different headers in the same request, unless - they contain the same string. - - - crunch-server-header is only meant for quick tests. - If you have to block several different headers, or only want to modify - parts of them, you should use a custom - server-header filter. - - - - Don't block any header without understanding the consequences. - - - - + + For Internet Explorer v.5-7: + - - Example usage (section): - - - # Crunch server headers that try to prevent caching -{ +crunch-server-header{no-cache} } -/ - - - - - + + Tools -> Internet Options -> Connections -> LAN Settings + + + Then, check Use Proxy and fill in the appropriate info + (Address: 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS + proxy support too (sometimes labeled Secure). Make sure any + checkboxes like Use the same proxy server for all protocols is + UNCHECKED. You want only HTTP and HTTPS (SSL)! + - - -crunch-outgoing-cookies + + +
Proxy Configuration Showing + Internet Explorer HTTP and HTTPS (Secure) Settings + + + + + + [ Screenshot of IE Proxy Configuration ] + + +
+ - - - Typical use: - - - Prevent the web server from reading any HTTP cookies from your system - - - - - Effect: - - - Deletes any Cookie: HTTP headers from client requests. - - - + + After doing this, flush your browser's disk and memory caches to force a + re-reading of all pages and to get rid of any ads that may be cached. Remove + any cookies, + if you want Privoxy to manage that. You are now + ready to start enjoying the benefits of using + Privoxy! + - - Type: - - - Boolean. - - + + Privoxy itself is typically started by specifying the + main configuration file to be used on the command line. If no configuration + file is specified on the command line, Privoxy + will look for a file named config in the current + directory. Except on Win32 where it will try config.txt. + + + +Red Hat and Fedora + + A default Red Hat installation may not start &my-app; upon boot. It will use + the file /etc/privoxy/config as its main configuration + file. + + + + # /etc/rc.d/init.d/privoxy start + + + + Or ... + + + + # service privoxy start + + + - - Parameter: - - - N/A - - - - - - Notes: - - - This action is only concerned with outgoing HTTP cookies. For - incoming HTTP cookies, use - crunch-incoming-cookies. - Use both to disable HTTP cookies completely. - - - It makes no sense at all to use this action in conjunction - with the session-cookies-only action, - since it would prevent the session cookies from being read. - - - + +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. + + + + # /etc/init.d/privoxy start + + + - - Example usage: - - - +crunch-outgoing-cookies - - - + +Windows + +Click on the &my-app; Icon to start Privoxy. If no configuration file is + specified on the command line, Privoxy will look + for a file named config.txt. Note that Windows will + automatically start &my-app; when the system starts if you chose that option + when installing. + + + Privoxy can run with full Windows service functionality. + On Windows only, the &my-app; program has two new command line arguments + to install and uninstall &my-app; as a service. See the + Windows Installation + instructions for details. + + - - + +Solaris, NetBSD, FreeBSD, HP-UX and others + +Example Unix startup command: + + + + # /usr/sbin/privoxy /etc/privoxy/config + + + + +OS/2 + + During installation, Privoxy is configured to + start automatically when the system restarts. You can start it manually by + double-clicking on the Privoxy icon in the + Privoxy folder. + + - - -deanimate-gifs + +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. + + + An administrator username and password must be supplied in order for + the Privoxy Utility to perform any of the tasks. + + - - - Typical use: - - Stop those annoying, distracting animated GIF images. - - - - Effect: - - - De-animate GIF animations, i.e. reduce them to their first or last image. - - - + +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). + + - - Type: - - - Parameterized. - - + +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 + + + - - Parameter: - - - last or first - - - - - - Notes: - - - This will also shrink the images considerably (in bytes, not pixels!). If - the option first is given, the first frame of the animation - is used as the replacement. If last is given, the last - frame of the animation is used instead, which probably makes more sense for - most banner animations, but also has the risk of not showing the entire - last frame (if it is only a delta to an earlier frame). - - - You can safely use this action with patterns that will also match non-GIF - objects, because no attempt will be made at anything that doesn't look like - a GIF. - - - + - -downgrade-http-version +must find a better place for this paragraph - - - Typical use: - - Work around (very rare) problems with HTTP/1.1 - - + + The included default configuration files should give a reasonable starting + point. Most of the per site configuration is done in the + actions files. These are + where various cookie actions are defined, ad and banner blocking, and other + aspects of Privoxy configuration. There are several + such files included, with varying levels of aggressiveness. + - - Effect: - - - Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0. - - - + + You will probably want to keep an eye out for sites for which you may prefer + persistent cookies, and add these to your actions configuration as needed. By + default, most of these will be accepted only during the current browser + session (aka session cookies), unless you add them to the + configuration. If you want the browser to handle this instead, you will need + to edit user.action (or through the web based interface) + and disable this feature. If you use more than one browser, it would make + more sense to let Privoxy handle this. In which + case, the browser(s) should be set to accept all cookies. + + + + Another feature where you will probably want to define exceptions for trusted + sites is the popup-killing (through +filter{popups}), + because your favorite shopping, banking, or leisure site may need + popups (explained below). + - - Type: - - - Boolean. - - + + Privoxy does not support all of the optional HTTP/1.1 + features yet. In the unlikely event that you experience inexplicable problems + with browsers that use HTTP/1.1 per default + (like Mozilla or recent versions of I.E.), you might + try to force HTTP/1.0 compatibility. For Mozilla, look under Edit -> + Preferences -> Debug -> Networking. + Alternatively, set the +downgrade-http-version config option in + default.action which will downgrade your browser's HTTP + requests from HTTP/1.1 to HTTP/1.0 before processing them. + - - Parameter: - - - N/A - - - - - - Notes: - - - 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. - - - + + After running Privoxy for a while, you can + start to fine tune the configuration to suit your personal, or site, + preferences and requirements. There are many, many aspects that can + be customized. Actions + can be adjusted by pointing your browser to + http://config.privoxy.org/ + (shortcut: http://p.p/), + and then follow the link to View & Change the Current Configuration. + (This is an internal page and does not require Internet access.) + - - Example usage (section): - - - {+downgrade-http-version} -problem-host.example.com - - - + + In fact, various aspects of Privoxy + configuration can be viewed from this page, including + current configuration parameters, source code version numbers, + the browser's request headers, and actions that apply + to a given URL. In addition to the actions file + editor mentioned above, Privoxy can also + be turned on and off (toggled) from this page. + - - + + If you encounter problems, try loading the page without + Privoxy. If that helps, enter the URL where + you have the problems into the browser + based rule tracing utility. See which rules apply and why, and + then try turning them off for that site one after the other, until the problem + is gone. When you have found the culprit, you might want to turn the rest on + again. + - - -fast-redirects + + If the above paragraph sounds gibberish to you, you might want to read more about the actions concept + or even dive deep into the Appendix + on actions. + - - - Typical use: - - Fool some click-tracking scripts and speed up indirect links. - - + + If you can't get rid of the problem at all, think you've found a bug in + Privoxy, want to propose a new feature or smarter rules, please see the + section Contacting the + Developers below. + - - Effect: - - - Detects redirection URLs and redirects the browser without contacting - the redirection server first. - - - +--> - - Type: - - - Parameterized. - - + + +Command Line Options + + Privoxy may be invoked with the following + command-line options: + - - 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/. + + + --config-test - - 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: - - - Not every URLs with other URLs as parameters is evil. - Some sites offer a real service that requires this information to work. - For example a validation service needs to know, which document to validate. - fast-redirects assumes that every URL parameter that - looks like another URL is a redirection target, and will always redirect to - the last one. Most of the time the assumption is correct, but if it isn't, - the user gets redirected anyway. - - - Another failure occurs if the URL contains other parameters after the URL parameter. - The URL: - http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar. - contains the redirection URL http://www.example.net/, - followed by another parameter. fast-redirects doesn't know that - and will cause a redirect to http://www.example.net/&foo=bar. - Depending on the target server configuration, the parameter will be silently ignored - or lead to a page not found error. You can prevent this problem by - first using the redirect action - to remove the last part of the URL, but it requires a little effort. - - - To detect a redirection URL, fast-redirects only - looks for the string http://, either in plain text - (invalid but often used) or encoded as http%3a//. - Some sites use their own URL encoding scheme, encrypt the address - of the target server or replace it with a database id. In theses cases - fast-redirects is fooled and the request reaches the - redirection server where it probably gets logged. - - - + + Exit after loading the configuration files before binding to + the listen address. The exit code signals whether or not the + configuration files have been successfully loaded. + + + If the exit code is 1, at least one of the configuration files + is invalid, if it is 0, all the configuration files have been + successfully loaded (but may still contain errors that can + currently only be detected at run time). + + + This option doesn't affect the log setting, combination with + --no-daemon is recommended if a configured + log file shouldn't be used. + + + + + --version + + + Print version info and exit. Unix only. + + + + + --help + + + Print short usage info and exit. Unix only. + + + + + --no-daemon + + + Don't become a daemon, i.e. don't fork and become process group + leader, and don't detach from controlling tty. Unix only. + + + + + --pidfile FILE + + + On startup, write the process ID to FILE. Delete the + FILE on exit. Failure to create or delete the + FILE is non-fatal. If no FILE + option is given, no PID file will be used. Unix only. + + + + + --user USER[.GROUP] + + + After (optionally) writing the PID file, assume the user ID of + USER, and if included the GID of GROUP. Exit if the + privileges are not sufficient to do so. Unix only. + + + + + --chroot + + + Before changing to the user ID given in the --user option, + chroot to that user's home directory, i.e. make the kernel pretend to the &my-app; + process that the directory tree starts there. If set up carefully, this can limit + the impact of possible vulnerabilities in &my-app; to the files contained in that hierarchy. + Unix only. + + + + + --pre-chroot-nslookup hostname + + + Specifies a hostname to look up before doing a chroot. On some systems, initializing the + resolver library involves reading config files from /etc and/or loading additional shared + libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces + the number of files that must be copied into the chroot tree. + + + For fastest startup speed, a good value is a hostname that is not in /etc/hosts but that + your local name server (listed in /etc/resolv.conf) can resolve without recursion + (that is, without having to ask any other name servers). The hostname need not exist, + but if it doesn't, an error message (which can be ignored) will be output. + + - - Example usage: - - - - { +fast-redirects{simple-check} } - one.example.com + + + configfile + + + If no configfile is included on the command line, + Privoxy will look for a file named + config in the current directory (except on Win32 + where it will look for config.txt instead). Specify + full path to avoid confusion. If no config file is found, + Privoxy will fail to start. + + - { +fast-redirects{check-decoded-url} } - another.example.com/testing - - - + + - - + + On MS Windows only there are two additional + command-line options to allow Privoxy to install and + run as a service. See the +Window Installation section +for details. + + + + + + + - -filter +Privoxy Configuration + + All Privoxy configuration is stored + in text files. These files can be edited with a text editor. + Many important aspects of Privoxy can + also be controlled easily with a web browser. + - - - Typical use: - - Get rid of HTML and JavaScript annoyances, banner advertisements (by size), - do fun text replacements, add personalized effects, etc. - - - - Effect: - - - 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 regular - expression based substitutions. (Note: as of version 3.0.3 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.) - - - + - - Type: - - - Parameterized. - - - - - Parameter: - - - The name of a content filter, as defined in the filter file. - Filters can be defined in one or more files as defined by the - filterfile - option in the config file. - default.filter is the collection of filters - supplied by the developers. Locally defined filters should go - in their own file, such as user.filter. - - - When used in its negative form, - and without parameters, all filtering is completely disabled. - - - - - - Notes: - - - For your convenience, there are a number of pre-defined filters available - in the distribution filter file that you can use. See the examples below for - a list. - - - Filtering requires buffering the page content, which may appear to - slow down page rendering since nothing is displayed until all content has - passed the filters. (It does not really take longer, but seems that way - since the page is not incrementally displayed.) This effect will be more - noticeable on slower connections. - - - Rolling your own - filters requires a knowledge of - Regular - Expressions and - HTML. - This is very powerful feature, and potentially very intrusive. - Filters should be used with caution, and where an equivalent - action is not available. - - - The amount of data that can be filtered is limited to the - buffer-limit - option in the main config file. The - default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered - data, and all pending data, is passed through unfiltered. - - - Inappropriate MIME types, such as zipped files, are not filtered at all. - (Again, only text-based types except plain text). Encrypted SSL data - (from HTTPS servers) cannot be filtered either, since this would violate - the integrity of the secure transaction. In some situations it might - be necessary to protect certain text, like source code, from filtering - by defining appropriate -filter exceptions. - - - Compressed content can't be filtered either, unless &my-app; - is compiled with zlib support (requires at least &my-app; 3.0.7), - in which case &my-app; will decompress the content before filtering - it. - - - If you use a &my-app; version without zlib support, but want filtering to work on - as much documents as possible, even those that would normally be sent compressed, - you must use the prevent-compression - action in conjunction with filter. - - - Content filtering can achieve some of the same effects as the - block - action, i.e. it can be used to block ads and banners. But the mechanism - works quite differently. One effective use, is to block ad banners - based on their size (see below), since many of these seem to be somewhat - standardized. - - - Feedback with suggestions for new or - improved filters is particularly welcome! - - - The below list has only the names and a one-line description of each - predefined filter. There are more - verbose explanations of what these filters do in the filter file chapter. - - - + +Controlling Privoxy with Your Web Browser + + Privoxy's user interface can be reached through the special + URL http://config.privoxy.org/ + (shortcut: http://p.p/), + which is a built-in page and works without Internet access. + You will see the following section: - - Example usage (with filters from the distribution default.filter file). - See the Predefined Filters section for - more explanation on each: - - - - +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse. - - - - +filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites). - - - - +filter{html-annoyances} # Get rid of particularly annoying HTML abuse. - - - - +filter{content-cookies} # Kill cookies that come in the HTML or JS content. - - - - +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups). - - - - +filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability. - - - - +filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability. - - - - +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective. - - - - +filter{banners-by-size} # Kill banners by size. - - - - +filter{banners-by-link} # Kill banners by their links to known clicktrackers. - - - - +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking). - + + + + + +     Privoxy Menu + + + +         ▪  View & change the current configuration + + +         ▪  View the source code version numbers + + +         ▪  View the request headers. + + +         ▪  Look up which actions apply to a URL and why + + +         ▪  Toggle Privoxy on or off + + +         ▪  Documentation + + + + + + + + This should be self-explanatory. Note the first item leads to an editor for the + actions files, which is where the ad, banner, + cookie, and URL blocking magic is configured as well as other advanced features of + Privoxy. This is an easy way to adjust various + aspects of Privoxy configuration. The actions + file, and other configuration files, are explained in detail below. + + + + Toggle Privoxy On or Off is handy for sites that might + have problems with your current actions and filters. You can in fact use + 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. + + + + Note that several of the features described above are disabled by default + in Privoxy 3.0.7 beta and later. + Check the + configuration file to learn why + and in which cases it's safe to enable them again. + + + + + + + + + + + + +Configuration Files Overview + + For Unix, *BSD and Linux, all configuration files are located in + /etc/privoxy/ by default. For MS Windows, OS/2, and + AmigaOS these are all in the same directory as the + Privoxy executable. + + + + The installed defaults provide a reasonable starting point, though + some settings may be aggressive by some standards. For the time being, the + principle configuration files are: + + + + + + - - +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap. + The main configuration file is named config + on Linux, Unix, BSD, OS/2, and AmigaOS and config.txt + on Windows. This is a required file. + + + - - +filter{jumping-windows} # Prevent windows from resizing and moving themselves. + match-all.action is used to define which actions + relating to banner-blocking, images, pop-ups, content modification, cookie handling + etc should be applied by default. It should be the first actions file loaded. - - +filter{frameset-borders} # Give frames a border and make them resizable. + default.action defines many exceptions (both positive and negative) + from the default set of actions that's configured in match-all.action. + It should be the second actions file loaded and shouldn't be edited by the user. - - +filter{demoronizer} # Fix MS's non-standard use of standard charsets. + Multiple actions files may be defined in config. These + are processed in the order they are defined. Local customizations and locally + preferred exceptions to the default policies as defined in + match-all.action (which you will most probably want + to define sooner or later) are best applied in user.action, + where you can preserve them across upgrades. The file isn't installed by all + installers, but you can easily create it yourself with a text editor. - - +filter{shockwave-flash} # Kill embedded Shockwave Flash objects. + There is also a web based editor that can be accessed from + http://config.privoxy.org/show-status + (Shortcut: http://p.p/show-status) for the + various actions files. + + + - - +filter{quicktime-kioskmode} # Make Quicktime movies saveable. + Filter files (the filter + file) can be used to re-write the raw page content, including + viewable text as well as embedded HTML and JavaScript, and whatever else + lurks on any given web page. The filtering jobs are only pre-defined here; + whether to apply them or not is up to the actions files. + default.filter includes various filters made + available for use by the developers. Some are much more intrusive than + others, and all should be used with caution. You may define additional + filter files in config as you can with + actions files. We suggest user.filter for any + locally defined filters or customizations. + + + + + + + The syntax of the configuration and filter files may change between different + Privoxy versions, unfortunately some enhancements cost backwards compatibility. + + + + + All files use the # character to denote a + comment (the rest of the line will be ignored) and understand line continuation + through placing a backslash ("\") as the very last character + in a line. If the # is preceded by a backslash, it looses + its special function. Placing a # in front of an otherwise + valid configuration line to prevent it from being interpreted is called "commenting + out" that line. Blank lines are ignored. + + + + The actions files and filter files + can use Perl style regular expressions for + maximum flexibility. + + + + After making any changes, there is no need to restart + Privoxy in order for the changes to take + effect. Privoxy detects such changes + automatically. Note, however, that it may take one or two additional + requests for the change to take effect. When changing the listening address + of Privoxy, these wake up requests + must obviously be sent to the old listening address. + + + + While under development, the configuration content is subject to change. + The below documentation may not be accurate by the time you read this. + Also, what constitutes a default setting, may change, so + please check all your configuration files on important issues. + +]]> + + + + + + + + + + + + &config; + + + + + + + + + +Actions Files + + + + + The actions files are used to define what actions + Privoxy takes for which URLs, and thus determines + how ad images, cookies and various other aspects of HTTP content and + transactions are handled, and on which sites (or even parts thereof). + There are a number of such actions, with a wide range of functionality. + Each action does something a little different. + These actions give us a veritable arsenal of tools with which to exert + our control, preferences and independence. Actions can be combined so that + their effects are aggregated when applied against a given set of URLs. + + + There + are three action files included with Privoxy with + differing purposes: + + + + - - +filter{fun} # Text replacements for subversive browsing fun! + match-all.action - is used to define which + actions relating to banner-blocking, images, pop-ups, + content modification, cookie handling etc should be applied by default. + It should be the first actions file loaded + + - - +filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably. + default.action - defines many exceptions (both + positive and negative) from the default set of actions that's configured + in match-all.action. It is a set of rules that should + work reasonably well as-is for most users. This file is only supposed to + be edited by the developers. It should be the second actions file loaded. + + - - +filter{ie-exploits} # Disable some known Internet Explorer bug exploits. + user.action - is intended to be for local site + preferences and exceptions. As an example, if your ISP or your bank + has specific requirements, and need special handling, this kind of + thing should go here. This file will not be upgraded. + + - - +filter{site-specifics} # Cure for site-specific problems. Don't apply generally! + Edit Set to Cautious Set to Medium Set to Advanced - - +filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags. + These have increasing levels of aggressiveness and have no + influence on your browsing unless you select them explicitly in the + editor. A default installation should be pre-set to + Cautious. New users should try this for a while before + adjusting the settings to more aggressive levels. The more aggressive + the settings, then the more likelihood there is of problems such as sites + not working as they should. - - +filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement. + The Edit button allows you to turn each + action on/off individually for fine-tuning. The Cautious + button changes the actions list to low/safe settings which will activate + ad blocking and a minimal set of &my-app;'s features, and subsequently + there will be less of a chance for accidental problems. The + Medium button sets the list to a medium level of + other features and a low level set of privacy features. The + Advanced button sets the list to a high level of + ad blocking and medium level of privacy. See the chart below. The latter + three buttons over-ride any changes via with the + Edit button. More fine-tuning can be done in the + lower sections of this internal page. - - +filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation. + While the actions file editor allows to enable these settings in all + actions files, they are only supposed to be enabled in the first one + to make sure you don't unintentionally overrule earlier rules. - - +filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation. + The default profiles, and their associated actions, as pre-defined in + default.action are: - - +filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this. - - - - - + Default Configurations + + + + + + + + Feature + Cautious + Medium + Advanced + + + + + + + + + + + + + + Ad-blocking Aggressiveness + medium + high + high + + + + Ad-filtering by size + no + yes + yes + + + + Ad-filtering by link + no + no + yes + + + Pop-up killing + blocks only + blocks only + blocks only + + + Privacy Features + low + medium + medium/high + - - -force-text-mode - - - - Typical use: - - Force Privoxy to treat a document as if it was in some kind of text format. - - + + Cookie handling + none + session-only + kill + - - Effect: - - - Declares a document as text, even if the Content-Type: isn't detected as such. - - - + + Referer forging + no + yes + yes + - - Type: - - - Boolean. - - + + GIF de-animation + no + yes + yes + - - Parameter: - - - N/A - - - + + Fast redirects + no + no + yes + - - 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 - - - - - - + + HTML taming + no + no + yes + + + JavaScript taming + no + no + yes + - - -forward-override - - - - Typical use: - - Change the forwarding settings based on User-Agent or request origin - - + + Web-bug killing + no + yes + yes + - - Effect: - - - Overrules the forward directives in the configuration file. - - - + + Image tag reordering + no + yes + yes + - - 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$ - - - - - - + + The list of actions files to be used are defined in the main configuration + file, and are processed in the order they are defined (e.g. + default.action is typically processed before + user.action). The content of these can all be viewed and + edited from http://config.privoxy.org/show-status. + The over-riding principle when applying actions, is that the last action that + matches a given URL wins. The broadest, most general rules go first + (defined in default.action), + followed by any exceptions (typically also in + default.action), which are then followed lastly by any + local preferences (typically in user.action). + Generally, user.action has the last word. + + + + An actions file typically has multiple sections. If you want to use + aliases in an actions file, you have to place the (optional) + alias section at the top of that file. + Then comes the default set of rules which will apply universally to all + sites and pages (be very careful with using such a + universal set in user.action or any other actions file after + default.action, because it will override the result + from consulting any previous file). And then below that, + exceptions to the defined universal policies. You can regard + user.action as an appendix to default.action, + with the advantage that it is a separate file, which makes preserving your + personal settings across Privoxy upgrades easier. + + + Actions can be used to block anything you want, including ads, banners, or + just some obnoxious URL whose content you would rather not see. Cookies can be accepted + or rejected, or accepted only during the current browser session (i.e. not + written to disk), content can be modified, some JavaScripts tamed, user-tracking + fooled, and much more. See below for a complete list + of actions. + - -handle-as-empty-document - - - - Typical use: - - Mark URLs that should be replaced by empty documents if they get blocked - - + +Finding the Right Mix + + Note that some actions, like cookie suppression + or script disabling, may render some sites unusable that rely on these + techniques to work properly. Finding the right mix of actions is not always easy and + certainly a matter of personal taste. And, things can always change, requiring + refinements in the configuration. In general, it can be said that the more + aggressive your default settings (in the top section of the + actions file) are, the more exceptions for trusted sites you + will have to make later. If, for example, you want to crunch all cookies per + default, you'll have to make exceptions from that rule for sites that you + regularly use and that require cookies for actually useful purposes, like maybe + your bank, favorite shop, or newspaper. + - - 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. - - - + + We have tried to provide you with reasonable rules to start from in the + distribution actions files. But there is no general rule of thumb on these + things. There just are too many variables, and sites are constantly changing. + Sooner or later you will want to change the rules (and read this chapter again :). + + - - Type: - - - Boolean. - - + + +How to Edit + + The easiest way to edit the actions files is with a browser by + using our browser-based editor, which can be reached from http://config.privoxy.org/show-status. + Note: the config file option enable-edit-actions must be enabled for + this to work. The editor allows both fine-grained control over every single + feature on a per-URL basis, and easy choosing from wholesale sets of defaults + like Cautious, Medium or + Advanced. Warning: the Advanced setting is more + aggressive, and will be more likely to cause problems for some sites. + Experienced users only! + - - Parameter: - - - N/A - - - + + If you prefer plain text editing to GUIs, you can of course also directly edit the + the actions files with your favorite text editor. Look at + default.action which is richly commented with many + good examples. + + - - 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$ - - - - - - + +How Actions are Applied to Requests + + Actions files are divided into sections. There are special sections, + like the alias sections which will + be discussed later. For now let's concentrate on regular sections: They have a + heading line (often split up to multiple lines for readability) which consist + of a list of actions, separated by whitespace and enclosed in curly braces. + Below that, there is a list of URL and tag patterns, each on a separate line. + + + To determine which actions apply to a request, the URL of the request is + compared to all URL patterns in each action file. + Every time it matches, the list of applicable actions for the request is + incrementally updated, using the heading of the section in which the + pattern is located. The same is done again for tags and tag patterns later on. + - - -handle-as-image + + If multiple applying sections set the same action differently, + the last match wins. If not, the effects are aggregated. + E.g. a URL might match a regular section with a heading line of { + +handle-as-image }, + then later another one with just { + +block }, resulting + in both actions to apply. And there may well be + cases where you will want to combine actions together. Such a section then + might look like: + - - - Typical use: - - Mark URLs as belonging to images (so they'll be replaced by images if they do get blocked, rather than HTML pages) - - + + + { +handle-as-image +block{Banner ads.} } + # Block these as if they were images. Send no block page. + banners.example.com + media.example.com/.*banners + .example.com/images/ads/ + - - 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. - - - + + You can trace this process for URL patterns and any given URL by visiting http://config.privoxy.org/show-url-info. + - - Type: - - - Boolean. - - + + Examples and more detail on this is provided in the Appendix, + Troubleshooting: Anatomy of an Action section. + + + + + +Patterns + + As mentioned, Privoxy uses patterns + to determine what actions might apply to which sites and + pages your browser attempts to access. These patterns use wild + card type pattern matching to achieve a high degree of + flexibility. This allows one expression to be expanded and potentially match + against many similar patterns. + + + + Generally, an URL pattern has the form + <domain><port>/<path>, where the + <domain>, 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, + 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, + it has to be put into angle brackets + (<, >). + + - Parameter: + www.example.com/ - N/A + is a domain-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. - - Notes: + www.example.com - - 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. + + means exactly the same. For domain-only patterns, the trailing / may + be omitted. - - Example usage (sections): + www.example.com/index.html - # 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 - + matches all the documents on www.example.com + whose name starts with /index.html. - - - - - - -hide-accept-language - - - Typical use: + www.example.com/index.html$ - Pretend to use different language settings. + + matches only the single document /index.html + on www.example.com. + - - Effect: + /index.html$ - Deletes or replaces the Accept-Language: HTTP header in client requests. + matches the document /index.html, regardless of the domain, + i.e. on any web server anywhere. - - Type: - + / - Parameterized. + + Matches any URL because there's no requirement for either the + domain or the path to match anything. + - - Parameter: + :8000/ - Keyword: block, or any user defined value. - + Matches any URL pointing to TCP port 8000. + - - Notes: + <2001:db8::1>/ - 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. + Matches any URL with the host address 2001:db8::1. + (Note that the real URL uses plain brackets, not angle brackets.) - - Example usage (section): + index.html - - # 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} \ -} -/ + + matches nothing, since it would be interpreted as a domain name and + there is no top-level domain called .html. So its + a mistake. - - -hide-content-disposition - +The Domain 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. + For example: + + - Typical use: + .example.com - Prevent download menus for content you prefer to view inside the browser. + + matches any domain with first-level domain com + and second-level domain example. + For example www.example.com, + example.com and foo.bar.baz.example.com. + Note that it wouldn't match if the second-level domain was another-example. + - - Effect: + www. - Deletes or replaces the Content-Disposition: HTTP header set by some servers. + matches any domain that STARTS with + www. (It also matches the domain + www but most of the time that doesn't matter.) - - Type: - + .example. - Parameterized. + + matches any domain that CONTAINS .example.. + And, by the way, also included would be any files or documents that exist + within that domain since no path limitations are specified. (Correctly + speaking: It matches any FQDN that contains example as + a domain.) This might be www.example.com, + news.example.de, or + www.example.net/cgi/testing.pl for instance. All these + cases are matched. + + + + + Additionally, there are wild-cards that you can use in the domain names + themselves. These work similarly to shell globbing type wild-cards: + * represents zero or more arbitrary characters (this is + equivalent to the + Regular + Expression based syntax of .*), + ? represents any single character (this is equivalent to the + regular expression syntax of a simple .), and you can define + character classes in square brackets which is similar to + the same regular expression technique. All of this can be freely mixed: + + - Parameter: + ad*.example.com - Keyword: block, or any user defined value. - + matches adserver.example.com, + ads.example.com, etc but not sfads.example.com + - - Notes: + *ad*.example.com - 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. + matches all of the above, and then some. + + + + .?pix.com + - This action will probably be removed in the future, - use server-header filters instead. + matches www.ipix.com, + pictures.epix.com, a.b.c.d.e.upix.com etc. - - Example usage: + www[1-9a-ez].example.c* - - # Disarm the download link in Sourceforge's patch tracker -{ -filter \ - +content-type-overwrite{text/plain}\ - +hide-content-disposition{block} } - .sourceforge.net/tracker/download\.php + + matches www1.example.com, + www4.example.cc, wwwd.example.cy, + wwwz.example.com etc., but not + wwww.example.com. + + + While flexible, this is not the sophistication of full regular expression based syntax. + + + + - -hide-if-modified-since - - - - Typical use: - - Prevent yet another way to track the user's steps between sessions. - - +The Path Pattern - - Effect: - - - Deletes the If-Modified-Since: HTTP client header or modifies its value. - - - + + Privoxy uses modern POSIX 1003.2 + Regular + Expressions for matching the path portion (after the slash), + and is thus more flexible. + + + + There is an Appendix with a brief quick-start into regular + expressions, you also might want to have a look at your operating system's documentation + on regular expressions (try man re_format). + + + + Note that the path pattern is automatically left-anchored at the /, + i.e. it matches as if it would start with a ^ (regular expression speak + for the beginning of a line). + + + + Please also note that matching in the path is CASE INSENSITIVE + by default, but you can switch to case sensitive at any point in the pattern by using the + (?-i) switch: www.example.com/(?-i)PaTtErN.* will match + only documents whose path starts with PaTtErN in + exactly this capitalization. + + - Type: - + .example.com/.* - Parameterized. + + Is equivalent to just .example.com, since any documents + within that domain are matched with or without the .* + regular expression. This is redundant + - - Parameter: + .example.com/.*/index.html$ - Keyword: block, or a user defined value that specifies a range of hours. - + Will match any page in the domain of example.com that is + named index.html, and that is part of some path. For + example, it matches www.example.com/testing/index.html but + NOT www.example.com/index.html because the regular + expression called for at least two /'s, thus the path + requirement. It also would match + www.example.com/testing/index_html, because of the + special meta-character .. + - - Notes: + .example.com/(.*/)?index\.html$ - 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. + This regular expression is conditional so it will match any page + named index.html regardless of path which in this case can + have one or more /'s. And this one must contain exactly + .html (but does not have to end with that!). + + + + .example.com/(.*/)(ads|banners?|junk) + - It is also recommended to use this action together with - crunch-if-none-match, - otherwise it's more or less pointless. + This regular expression will match any path of example.com + that contains any of the words ads, banner, + banners (because of the ?) or junk. + The path does not have to end in these words, just contain them. - - Example usage (section): + .example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$ - - # 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} -/ + + This is very much the same as above, except now it must end in either + .jpg, .jpeg, .gif or .png. So this + one is limited to common image formats. + + + There are many, many good examples to be found in default.action, + and more tutorials below in Appendix on regular expressions. + + + + - -hide-from-header +The Tag Pattern + + + Tag patterns are used to change the applying actions based on the + request's tags. Tags can be created with either the + client-header-tagger + or the server-header-tagger action. + + + + Tag patterns have to start with TAG:, so &my-app; + can tell them apart from URL patterns. Everything after the colon + including white space, is interpreted as a regular expression with + path pattern syntax, except that tag patterns aren't left-anchored + automatically (&my-app; doesn't silently add a ^, + you have to do it yourself if you need it). + + + + To match all requests that are tagged with foo + your pattern line should be TAG:^foo$, + TAG:foo would work as well, but it would also + match requests whose tags contain foo somewhere. + TAG: foo wouldn't work as it requires white space. + + + + Sections can contain URL and tag patterns at the same time, + but tag patterns are checked after the URL patterns and thus + always overrule them, even if they are located before the URL patterns. + + + + Once a new tag is added, Privoxy checks right away if it's matched by one + of the tag patterns and updates the action settings accordingly. As a result + tags can be used to activate other tagger actions, as long as these other + taggers look for headers that haven't already be parsed. + + + + For example you could tag client requests which use the + POST method, + then use this tag to activate another tagger that adds a tag if cookies + are sent, and then use a block action based on the cookie tag. This allows + the outcome of one action, to be input into a subsequent action. However if + you'd reverse the position of the described taggers, and activated the + method tagger based on the cookie tagger, no method tags would be created. + The method tagger would look for the request line, but at the time + the cookie tag is created, the request line has already been parsed. + + + + While this is a limitation you should be aware of, this kind of + indirection is seldom needed anyway and even the example doesn't + make too much sense. + + + + + + + + + + + + +Actions + + All actions are disabled by default, until they are explicitly enabled + somewhere in an actions file. Actions are turned on if preceded with a + +, and turned off if preceded with a -. So a + +action means do that action, e.g. + +block means please block URLs that match the + following patterns, and -block means don't + block URLs that match the following patterns, even if +block + previously applied. + + + + + Again, actions are invoked by placing them on a line, enclosed in curly braces and + separated by whitespace, like in + {+some-action -some-other-action{some-parameter}}, + followed by a list of URL patterns, one per line, to which they apply. + Together, the actions line and the following pattern lines make up a section + of the actions file. + + + + Actions fall into three categories: + + + + + + + Boolean, i.e the action can only be enabled or + disabled. Syntax: + + + + +name # enable action name + -name # disable action name + + + Example: +handle-as-image + + + + + + + Parameterized, where some value is required in order to enable this type of action. + Syntax: + + + + +name{param} # enable action and set parameter to param, + # overwriting parameter from previous match if necessary + -name # disable action. The parameter can be omitted + + + Note that if the URL matches multiple positive forms of a parameterized action, + the last match wins, i.e. the params from earlier matches are simply ignored. + + + Example: +hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4} + + + + + + Multi-value. These look exactly like parameterized actions, + but they behave differently: If the action applies multiple times to the + same URL, but with different parameters, all the parameters + from all matches are remembered. This is used for actions + that can be executed for the same request repeatedly, like adding multiple + headers, or filtering through multiple filters. Syntax: + + + + +name{param} # enable action and add param to the list of parameters + -name{param} # remove the parameter param from the list of parameters + # If it was the last one left, disable the action. + -name # disable this action completely and remove all parameters from the list + + + Examples: +add-header{X-Fun-Header: Some text} and + +filter{html-annoyances} + + + + + + + + If nothing is specified in any actions file, no actions are + taken. So in this case Privoxy would just be a + normal, non-blocking, non-filtering proxy. You must specifically enable the + privacy and blocking features you need (although the provided default actions + files will give a good starting point). + + + + Later defined action sections always over-ride earlier ones of the same type. + So exceptions to any rules you make, should come in the latter part of the file (or + in a file that is processed later when using multiple actions files such + as user.action). For multi-valued actions, the actions + are applied in the order they are specified. Actions files are processed in + the order they are defined in config (the default + installation has three actions files). It also quite possible for any given + URL to match more than one pattern (because of wildcards and + regular expressions), and thus to trigger more than one set of actions! Last + match wins. + + + + + The list of valid Privoxy actions are: + + + + + + + + + + + + + +add-header Typical use: - Keep your (old and ill) browser from telling web servers your email address + Confuse log analysis, custom applications @@ -5041,17 +3684,16 @@ new action Effect: - Deletes any existing From: HTTP header, or replaces it with the - specified string. + Sends a user defined HTTP header to the web server. Type: - + - Parameterized. + Multi-value. @@ -5059,27 +3701,24 @@ new action Parameter: - Keyword: block, or any user defined value. + Any string value is possible. Validity of the defined HTTP headers is not checked. + It is recommended that you use the X- prefix + for custom headers. - - + + 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 may be specified multiple times, in order to define multiple + headers. This is rarely needed for the typical user. If you don't know what + HTTP headers are, you definitely don't need to worry about this + one. - This action is rarely needed, as modern web browsers don't send - From: headers anymore. + Headers added by this action are not modified by other actions. @@ -5087,9 +3726,8 @@ new action Example usage: - - +hide-from-header{block} or - +hide-from-header{spam-me-senseless@sittingduck.example.com} + + +add-header{X-User-Tracking: sucks} @@ -5098,14 +3736,14 @@ new action - -hide-referrer - + +block + Typical use: - Conceal which link you followed to get to a particular site + Block ads or other unwanted content @@ -5113,15 +3751,23 @@ new action Effect: - Deletes the Referer: (sic) HTTP header from the client request, - or replaces it with a forged one. + Requests for URLs to which this action applies are blocked, i.e. the + requests are trapped by &my-app; and the requested URL is never retrieved, + but is answered locally with a substitute page or image, as determined by + the handle-as-image, + set-image-blocker, and + handle-as-empty-document actions. + Type: - + Parameterized. @@ -5130,170 +3776,78 @@ new action 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. - - + A block reason that should be given to the user. - - + + 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. + Privoxy sends a special BLOCKED page + for requests to blocked pages. This page contains the block reason given as + parameter, a link to find out why the block action applies, and a click-through + to the blocked content (the latter only if the force feature is available and + enabled). - 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. + A very important exception occurs if both + block and handle-as-image, + apply to the same request: it will then be replaced by an image. If + set-image-blocker + (see below) also applies, the type of image will be determined by its parameter, + if not, the standard checkerboard pattern is sent. - 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.) + It is important to understand this process, in order + to understand how Privoxy deals with + ads and other unwanted content. Blocking is a core feature, and one + upon which various other features depend. - - - - - Example usage: - - +hide-referrer{forge} or - +hide-referrer{http://www.yahoo.com/} + The filter + action can perform a very similar task, by blocking + banner images and other content through rewriting the relevant URLs in the + document's HTML source, so they don't get requested in the first place. + Note that this is a totally different technique, and it's easy to confuse the two. - - - - - - -hide-user-agent - - Typical use: + Example usage (section): - Try to conceal your type of browser and client operating system - - + + {+block{No nasty stuff for you.}} +# Block and replace with "blocked" page + .nasty-stuff.example.com - - Effect: - - - Replaces the value of the User-Agent: HTTP header - in client requests with the specified value. - - - +{+block{Doubleclick banners.} +handle-as-image} +# Block and replace with image + .ad.doubleclick.net + .ads.r.us/banners/ - - Type: - - - Parameterized. +{+block{Layered ads.} +handle-as-empty-document} +# Block and then ignore + adserver.example.net/.*\.js$ + - - 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). Example of this: some MSN sites will not - let Mozilla enter, yet forging to a - Netscape 6.1 user-agent works just fine. - (Must be just a silly MS goof, I'm sure :-). - - - 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 + +change-x-forwarded-for Typical use: - Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted sites + Improve privacy by not forwarding the source of the request in the HTTP headers. @@ -5301,7 +3855,8 @@ new action Effect: - Specifies to which ports HTTP CONNECT requests are allowable. + Deletes the X-Forwarded-For: HTTP header from the client request, + or adds a new one. @@ -5317,49 +3872,37 @@ new action 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). - + + + block to delete the header. + + + + add to create the header (or append + the client's IP address to an already existing one). + + + - + 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. + It is safe and recommended to use block. - 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. - + Forwarding the source address of the request may make + sense in some multi-user setups but is also a privacy risk. + - - Example usages: + Example usage: - - - - +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 + +change-x-forwarded-for{block} @@ -5367,16 +3910,15 @@ new action - -prevent-compression + +client-header-filter Typical use: - Ensure that servers send the content uncompressed, so it can be - passed through filters. + Rewrite or remove single client headers. @@ -5385,16 +3927,17 @@ new action Effect: - Removes the Accept-Encoding header which can be used to ask for compressed transfer. + All client headers to which this action applies are filtered on-the-fly through + the specified regular expression based substitutions. Type: - + - Boolean. + Parameterized. @@ -5402,69 +3945,48 @@ new action Parameter: - N/A + The name of a client-header filter, as defined in one of the + filter files. - + 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. + Client-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. - 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. + Client-header filters are executed after the other header actions have finished + and use their output as input. - 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. + 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. - 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. + Please refer to the filter file chapter + to learn which client-header filters are available by default, and how to + create your own. + - Example usage (sections): + Example usage (section): - - -# 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/ + + +# Hide Tor exit notation in Host and Referer Headers +{+client-header-filter{hide-tor-exit-notation}} +/ + @@ -5474,16 +3996,16 @@ new action - -overwrite-last-modified - + +client-header-tagger + Typical use: - Prevent yet another way to track the user's steps between sessions. + + Block requests based on their headers. + @@ -5491,14 +4013,16 @@ new action Effect: - Deletes the Last-Modified: HTTP server header or modifies its value. + Client 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. @@ -5508,81 +4032,88 @@ new action Parameter: - One of the keywords: block, reset-to-request-time - and randomize - + The name of a client-header tagger, as defined in one of the + filter files. + - + 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. + Client-header taggers are applied to each header on its own, + and as the header isn't modified, each tagger sees + the original. - It is also recommended to use this action together with - crunch-if-none-match. + Client-header taggers are the first actions that are executed + and their tags can be used to control every other action. - + - Example usage: + Example usage (section): - # Let the browser revalidate without being tracked across sessions -{ +hide-if-modified-since{-60} \ - +overwrite-last-modified{randomize} \ - +crunch-if-none-match} -/ + +# Tag every request with the User-Agent header +{+client-header-tagger{user-agent}} +/ + +# Tagging itself doesn't change the action +# settings, sections with TAG patterns do: +# +# If it's a download agent, use a different forwarding proxy, +# show the real User-Agent and make sure resume works. +{+forward-override{forward-socks5 10.0.0.2:2222 .} \ + -hide-if-modified-since \ + -overwrite-last-modified \ + -hide-user-agent \ + -filter \ + -deanimate-gifs \ +} +TAG:^User-Agent: NetBSD-ftp/ +TAG:^User-Agent: Novell ZYPP Installer +TAG:^User-Agent: RPM APT-HTTP/ +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$ + + + - -redirect - + +content-type-overwrite + Typical use: - - Redirect requests to other sites. - + Stop useless download menus from popping up, or change the browser's rendering mode @@ -5590,8 +4121,7 @@ new action Effect: - Convinces the browser that the requested document has been moved - to another location and the browser should get it from there. + Replaces the Content-Type: HTTP server header. @@ -5600,7 +4130,7 @@ new action Type: - Parameterized + Parameterized. @@ -5608,89 +4138,94 @@ new action Parameter: - An absolute URL or a single pcrs command. + Any string. - + 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. + The Content-Type: HTTP server header is used by the + browser to decide what to do with the document. The value of this + header can cause the browser to open a download menu instead of + displaying the document by itself, even if the document's format is + supported by the browser. - 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. + The declared content type can also affect which rendering mode + the browser chooses. If XHTML is delivered as text/html, + many browsers treat it as yet another broken HTML document. + If it is send as application/xml, browsers with + XHTML support will only display it, if the syntax is correct. - 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. + If you see a web site that proudly uses XHTML buttons, but sets + Content-Type: text/html, you can use &my-app; + to overwrite it with application/xml and validate + the web master's claim inside your XHTML-supporting browser. + If the syntax is incorrect, the browser will complain loudly. - In case of problems with your redirects, or simply to watch - them working, enable debug 128. + You can also go the opposite direction: if your browser prints + error messages instead of rendering a document falsely declared + as XHTML, you can overwrite the content type with + text/html and have it rendered as broken HTML document. - - - - - 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 + By default content-type-overwrite only replaces + Content-Type: headers that look like some kind of text. + If you want to overwrite it unconditionally, you have to combine it with + force-text-mode. + This limitation exists for a reason, think twice before circumventing it. + + + Most of the time it's easier to replace this action with a custom + server-header filter. + It allows you to activate it for every document of a certain site and it will still + only replace the content types you aimed at. + + + Of course you can apply content-type-overwrite + to a whole site and then make URL based exceptions, but it's a lot + more work to get the same precision. + + + -# Redirect MSN search requests to Yahoo -{+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}} -search.msn.com//results\.aspx\?q= + + Example usage (sections): + + + # Check if www.example.net/ really uses valid XHTML +{ +content-type-overwrite{application/xml} } +www.example.net/ -# Redirect remote requests for this manual -# to the local version delivered by Privoxy -{+redirect{s@^http://www@http://config@}} -www.privoxy.org/user-manual/ +# but leave the content type unmodified if the URL looks like a style sheet +{-content-type-overwrite} +www.example.net/.*\.css$ +www.example.net/.*style + - - -server-header-filter + + +crunch-client-header Typical use: - - Rewrite or remove single server headers. - + Remove a client header Privoxy has no dedicated action for. @@ -5698,15 +4233,14 @@ www.privoxy.org/user-manual/ Effect: - All server headers to which this action applies are filtered on-the-fly - through the specified regular expression based substitutions. + Deletes every header sent by the client that contains the string the user supplied as parameter. Type: - + Parameterized. @@ -5716,63 +4250,65 @@ www.privoxy.org/user-manual/ Parameter: - The name of a server-header filter, as defined in one of the - filter files. + Any string. - + 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. + This action allows you to block client headers for which no dedicated + Privoxy action exists. + Privoxy will remove every client header that + contains the string you supplied as parameter. - Server-header filters are executed after the other header actions have finished - and use their output as input. + Regular expressions are not supported and you can't + use this action to block different headers in the same request, unless + they contain the same string. - Please refer to the filter file chapter - to learn which server-header filters are available by default, and how to - create your own. + crunch-client-header is only meant for quick tests. + If you have to block several different headers, or only want to modify + parts of them, you should use a + client-header filter. - + + + Don't block any header without understanding the consequences. + + + 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 + # Block the non-existent "Privacy-Violation:" client header +{ +crunch-client-header{Privacy-Violation:} } +/ - + - - -server-header-tagger - + +crunch-if-none-match + Typical use: - - Enable or disable filters based on the Content-Type header. - + Prevent yet another way to track the user's steps between sessions. @@ -5780,18 +4316,16 @@ example.org/instance-that-is-delivered-as-xml-but-is-not 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. + Deletes the If-None-Match: HTTP client header. Type: - + - Parameterized. + Boolean. @@ -5799,63 +4333,65 @@ example.org/instance-that-is-delivered-as-xml-but-is-not Parameter: - The name of a server-header tagger, as defined in one of the - filter files. + N/A - + Notes: - Server-header taggers are applied to each header on its own, - and as the header isn't modified, each tagger sees - the original. + Removing the If-None-Match: HTTP client 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. - 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). + It is also useful to make sure the header isn't used as a cookie + replacement (unlikely but possible). - Obviously crunching based on tags created by server-header taggers - doesn't prevent the request from showing up in the server's log file. + Blocking the If-None-Match: header shouldn't cause any + caching problems, as long as the If-Modified-Since: header + isn't blocked or missing as well. - - + + It is recommended to use this action together with + hide-if-modified-since + and + overwrite-last-modified. + + Example usage (section): - -# Tag every request with the content type declared by the server -{+server-header-tagger{content-type}} -/ - - + # Let the browser revalidate cached documents but don't +# allow the server to use the revalidation headers for user tracking. +{+hide-if-modified-since{-60} \ + +overwrite-last-modified{randomize} \ + +crunch-if-none-match} +/ + - - -session-cookies-only + +crunch-incoming-cookies Typical use: - Allow only temporary session cookies (for the current - browser session only). + Prevent the web server from setting HTTP cookies on your system @@ -5864,14 +4400,12 @@ example.org/instance-that-is-delivered-as-xml-but-is-not Effect: - Deletes the expires field from Set-Cookie: - server headers. Most browsers will not store such cookies permanently and - forget them in between sessions. + Deletes any Set-Cookie: HTTP headers from server replies. - + Type: @@ -5887,42 +4421,21 @@ example.org/instance-that-is-delivered-as-xml-but-is-not - + 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. + This action is only concerned with incoming HTTP cookies. For + outgoing HTTP cookies, use + crunch-outgoing-cookies. + Use both to disable HTTP cookies completely. - Privoxy also uses - the content-cookies filter - to block some types of cookies. Content cookies are not effected by - session-cookies-only. + It makes no sense at all to use this action in conjunction + with the session-cookies-only action, + since it would prevent the session cookies from being set. See also + filter-content-cookies. @@ -5931,7 +4444,7 @@ example.org/instance-that-is-delivered-as-xml-but-is-not Example usage: - +session-cookies-only + +crunch-incoming-cookies @@ -5940,14 +4453,16 @@ example.org/instance-that-is-delivered-as-xml-but-is-not - -set-image-blocker - + +crunch-server-header + Typical use: - Choose the replacement for blocked images + Remove a server header Privoxy has no dedicated action for. @@ -5955,97 +4470,62 @@ example.org/instance-that-is-delivered-as-xml-but-is-not 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. + Deletes every header sent by the server that contains the string the user supplied as parameter. - - - 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. - - - + + + Type: + + + Parameterized. - Notes: + Parameter: - 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. + Any string. - Example usage: + Notes: - Built-in pattern: - - - +set-image-blocker{pattern} - - - Redirect to the BSD daemon: + This action allows you to block server headers for which no dedicated + Privoxy action exists. Privoxy + will remove every server header that contains the string you supplied as parameter. - +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif} + Regular expressions are not supported and you can't + use this action to block different headers in the same request, unless + they contain the same string. - Redirect to the built-in pattern for better caching: + crunch-server-header is only meant for quick tests. + If you have to block several different headers, or only want to modify + parts of them, you should use a custom + server-header filter. - - +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern} + + + Don't block any header without understanding the consequences. + + + + + + + Example usage (section): + + + # Crunch server headers that try to prevent caching +{ +crunch-server-header{no-cache} } +/ @@ -6054,3683 +4534,5084 @@ example.org/instance-that-is-delivered-as-xml-but-is-not - -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. - + +crunch-outgoing-cookies - - The first section in this file is a special section for internal use - that prevents older &my-app; versions from reading the file: - + + + Typical use: + + + Prevent the web server from reading any HTTP cookies from your system + + + - - -########################################################################## -# Settings -- Don't change! For internal Privoxy use ONLY. -########################################################################## -{{settings}} -for-privoxy-version=3.0.11 - + + Effect: + + + Deletes any Cookie: HTTP headers from client requests. + + + - - 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: - + + Type: + + + Boolean. + + - - -########################################################################## -# Aliases -########################################################################## -{{alias}} + + Parameter: + + + N/A + + + - # 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} + + Notes: + + + This action is only concerned with outgoing HTTP cookies. For + incoming HTTP cookies, use + crunch-incoming-cookies. + Use both to disable HTTP cookies completely. + + + It makes no sense at all to use this action in conjunction + with the session-cookies-only action, + since it would prevent the session cookies from being read. + + + - # 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} - + + Example usage: + + + +crunch-outgoing-cookies + + + - - 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 - + + +deanimate-gifs - - 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 - + + + Typical use: + + Stop those annoying, distracting animated GIF images. + + - - 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: - + + Effect: + + + De-animate GIF animations, i.e. reduce them to their first or last image. + + + - - -{ -fast-redirects } -login.yahoo.com -edit.*.yahoo.com -.google.com -.altavista.com/.*(like|url|link):http -.altavista.com/trans.*urltext=http -.nytimes.com - + + Type: + + + Parameterized. + + - - 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: - + + Parameter: + + + last or first + + + - - -########################################################################## -# Images: -########################################################################## + + Notes: + + + This will also shrink the images considerably (in bytes, not pixels!). If + the option first is given, the first frame of the animation + is used as the replacement. If last is given, the last + frame of the animation is used instead, which probably makes more sense for + most banner animations, but also has the risk of not showing the entire + last frame (if it is only a delta to an earlier frame). + + + You can safely use this action with patterns that will also match non-GIF + objects, because no attempt will be made at anything that doesn't look like + a GIF. + + + -# 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)$ - + + Example usage: + + + +deanimate-gifs{last} + + + + + - - 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: - + + +downgrade-http-version - - -# 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 - + + + Typical use: + + Work around (very rare) problems with HTTP/1.1 + + - - 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: - + + Effect: + + + Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0. + + + - - -########################################################################## -# Block these fine banners: -########################################################################## -{ +block{Banner ads.} } + + Type: + + + Boolean. + + -# 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)?)/ + + Parameter: + + + N/A + + + -# Site-specific patterns (abbreviated): -# -.hitbox.com - + + Notes: + + + 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. + + + 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. + + + - - 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. - + + Example usage (section): + + + {+downgrade-http-version} +problem-host.example.com + + + - - -########################################################################## -# 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) + + +fast-redirects -# By path: -# -/.*loads/ + + + Typical use: + + Fool some click-tracking scripts and speed up indirect links. + + -# Site-specific: -# -www.globalintersec.com/adv # (adv = advanced) -www.ugu.com/sui/ugu/adv - + + Effect: + + + Detects redirection URLs and redirects the browser without contacting + the redirection server first. + + + - - 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! - + + Type: + + + Parameterized. + + - - -# Don't filter code! -# -{ -filter } -/(.*/)?cvs -bugzilla. -developer. -wiki. -.sourceforge.net - + + 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 actual default.action is of course much more - comprehensive, but we hope this example made clear how it works. - + + 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: + + + Not every URLs with other URLs as parameters is evil. + Some sites offer a real service that requires this information to work. + For example a validation service needs to know, which document to validate. + fast-redirects assumes that every URL parameter that + looks like another URL is a redirection target, and will always redirect to + the last one. Most of the time the assumption is correct, but if it isn't, + the user gets redirected anyway. + + + Another failure occurs if the URL contains other parameters after the URL parameter. + The URL: + http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar. + contains the redirection URL http://www.example.net/, + followed by another parameter. fast-redirects doesn't know that + and will cause a redirect to http://www.example.net/&foo=bar. + Depending on the target server configuration, the parameter will be silently ignored + or lead to a page not found error. You can prevent this problem by + first using the redirect action + to remove the last part of the URL, but it requires a little effort. + + + To detect a redirection URL, fast-redirects only + looks for the string http://, either in plain text + (invalid but often used) or encoded as http%3a//. + Some sites use their own URL encoding scheme, encrypt the address + of the target server or replace it with a database id. In theses cases + fast-redirects is fooled and the request reaches the + redirection server where it probably gets logged. + + + + + + Example usage: + + + + { +fast-redirects{simple-check} } + one.example.com + { +fast-redirects{check-decoded-url} } + another.example.com/testing + + + + + -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. - + + +filter - - So let's look at a few examples of things that one might typically do in - user.action: - + + + Typical use: + + Get rid of HTML and JavaScript annoyances, banner advertisements (by size), + do fun text replacements, add personalized effects, etc. + + + + Effect: + + + 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 regular + expression based substitutions. (Note: as of version 3.0.3 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.) + + + - + + Type: + + + Parameterized. + + - - -# My user.action file. <fred@example.com> - + + Parameter: + + + The name of a content filter, as defined in the filter file. + Filters can be defined in one or more files as defined by the + filterfile + option in the config file. + default.filter is the collection of filters + supplied by the developers. Locally defined filters should go + in their own file, such as user.filter. + + + When used in its negative form, + and without parameters, all filtering is completely disabled. + + + - - 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: - + + Notes: + + + For your convenience, there are a number of pre-defined filters available + in the distribution filter file that you can use. See the examples below for + a list. + + + Filtering requires buffering the page content, which may appear to + slow down page rendering since nothing is displayed until all content has + passed the filters. (The total time until the page is completely rendered + doesn't change much, but it may be perceived as slower since the page is + not incrementally displayed.) + This effect will be more noticeable on slower connections. + + + Rolling your own + filters requires a knowledge of + Regular + Expressions and + HTML. + This is very powerful feature, and potentially very intrusive. + Filters should be used with caution, and where an equivalent + action is not available. + + + The amount of data that can be filtered is limited to the + buffer-limit + option in the main config file. The + default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered + data, and all pending data, is passed through unfiltered. + + + Inappropriate MIME types, such as zipped files, are not filtered at all. + (Again, only text-based types except plain text). Encrypted SSL data + (from HTTPS servers) cannot be filtered either, since this would violate + the integrity of the secure transaction. In some situations it might + be necessary to protect certain text, like source code, from filtering + by defining appropriate -filter exceptions. + + + Compressed content can't be filtered either, but if &my-app; + is compiled with zlib support and a supported compression algorithm + is used (gzip or deflate), &my-app; can first decompress the content + and then filter it. + + + If you use a &my-app; version without zlib support, but want filtering to work on + as much documents as possible, even those that would normally be sent compressed, + you must use the prevent-compression + action in conjunction with filter. + + + Content filtering can achieve some of the same effects as the + block + action, i.e. it can be used to block ads and banners. But the mechanism + works quite differently. One effective use, is to block ad banners + based on their size (see below), since many of these seem to be somewhat + standardized. + + + Feedback with suggestions for new or + improved filters is particularly welcome! + + + The below list has only the names and a one-line description of each + predefined filter. There are more + verbose explanations of what these filters do in the filter file chapter. + + + + + + Example usage (with filters from the distribution default.filter file). + See the Predefined Filters section for + more explanation on each: + + + + +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse. + + + + +filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites). + + + + +filter{html-annoyances} # Get rid of particularly annoying HTML abuse. + + + + +filter{content-cookies} # Kill cookies that come in the HTML or JS content. + + + + +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups). + + + + +filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability. + + + + +filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability. + + + + +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective. + + + + +filter{banners-by-size} # Kill banners by size. + + + + +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. + + + + + - - -# 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 + + +force-text-mode + + + + Typical use: + + Force Privoxy to treat a document as if it was in some kind of text format. + + -# Allow ads for selected useful free sites: -# -allow-ads = -block -filter{banners-by-size} -filter{banners-by-link} + + Effect: + + + Declares a document as text, even if the Content-Type: isn't detected as such. + + + -# 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 + + Type: + + + Boolean. + + - + + Parameter: + + + N/A + + + - - 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. - + + 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. + + + + - - -{ allow-all-cookies } - sourceforge.net - .yahoo.com - .msdn.microsoft.com - .redhat.com - + + Example usage: + + + ++force-text-mode + + + + + + - - Your bank is allergic to some filter, but you don't know which, so you disable them all: - - - -{ -filter } - .your-home-banking-site.com - + + +forward-override + + + + Typical use: + + Change the forwarding settings based on User-Agent or request origin + + - - Some file types you may not want to filter for various reasons: - + + Effect: + + + Overrules the forward directives in the configuration file. + + + - - -# Technical documentation is likely to contain strings that might -# erroneously get altered by the JavaScript-oriented filters: -# -.tldp.org -/(.*/)?selfhtml/ + + Type: + + + Multi-value. + + -# 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/ - + + 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). + + + + + - - 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: - + + 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. + + + + - - -{ +block{Nasty ads.} } - www.example.com/nasty-ads/sponsor\.gif - another.example.net/more/junk/here/ - + + 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$ + + + + + + - - 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/ - + + +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. + + + - - 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: - + + Type: + + + Boolean. + + - - -{ fragile } - .forbes.com - webmail.example.com - .mybank.com - + + Parameter: + + + N/A + + + - - 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: - + + 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. + + + - - -{ +filter{fun} } - / # For ALL sites! - + + 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$ + + + + + + - - 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: - + + +handle-as-image - - -{ allow-ads } - .sourceforge.net - .slashdot.org - .osdn.net - + + + Typical use: + + Mark URLs as belonging to images (so they'll be replaced by images if they do get blocked, rather than HTML pages) + + - - Note that allow-ads has been aliased to - -block, - -filter{banners-by-size}, and - -filter{banners-by-link} above. - + + 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. + + + - - 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. - + + Type: + + + Boolean. + + - - -{ handle-as-text } - /.*\.sh$ - + + Parameter: + + + N/A + + + - - 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: - + + 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. + + + - - -{ +set-image-blocker{blank} } -/ # ALL sites - + + 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. + + + - -Filter Files + + Type: + + + Parameterized. + + - - On-the-fly text substitutions need - to be defined in a filter file. Once defined, they - can then be invoked as an action. - + + Parameter: + + + Keyword: block, or any user defined value. + + + - - &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. - + + 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. + + + - - &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. - + + 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} \ +} +/ + + + + + - - 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. - + + +hide-content-disposition + + + + Typical use: + + Prevent download menus for content you prefer to view inside the browser. + + - - 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. - + + Effect: + + + Deletes or replaces the Content-Disposition: HTTP header set by some servers. + + + - - 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. - + + Type: + + + Parameterized. + + - - 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. - + + Parameter: + + + Keyword: block, or any user defined value. + + + - - 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. - + + 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. + + + - - 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. - - - - 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: - + + 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 + + + + + - - FILTER: foo Replace all "foo" with "bar" - - - 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. - + + +hide-if-modified-since + + + + Typical use: + + Prevent yet another way to track the user's steps between sessions. + + - - 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. - + + 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. + + + -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: - + + 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. + + + - - s/foo/bar/ - + + 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} +/ + + + + + - - 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: - - - s/foo/bar/g - + + +hide-from-header - - Our complete filter now looks like this: - - - FILTER: foo Replace all "foo" with "bar" -s/foo/bar/g - + + + Typical use: + + Keep your (old and ill) browser from telling web servers your email address + + - - 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: - + + Effect: + + + Deletes any existing From: HTTP header, or replaces it with the + specified string. + + + + + Type: + + + Parameterized. + + - - -FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse + + Parameter: + + + Keyword: block, or any user defined value. + + + -# 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 - + + 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. + + + - - 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 (\). - + + Example usage: + + + +hide-from-header{block} or + +hide-from-header{spam-me-senseless@sittingduck.example.com} + + + + + - - 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. - - - 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). - + + +hide-referrer + + + + Typical use: + + Conceal which link you followed to get to a particular site + + - - 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. - + + Effect: + + + Deletes the Referer: (sic) HTTP header from the client request, + or replaces it with a forged one. + + + - - 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. - + + Type: + + + Parameterized. + + - - 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. - + + 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. + + + + - - 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!". - + + 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.) + + + - - 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. - + + Example usage: + + + +hide-referrer{forge} or + +hide-referrer{http://www.yahoo.com/} + + + + + - - We'll show you two other jobs from the JavaScript taming department, but - this time only point out the constructs of special interest: - - - -# The status bar is for displaying link targets, not pointless blahblah -# -s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig - + + +hide-user-agent - - \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. - + + + Typical use: + + Try to conceal your type of browser and client operating system + + - - 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. - + + Effect: + + + Replaces the value of the User-Agent: HTTP header + in client requests with the specified value. + + + - - -# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html -# -s/(<body [^>]*)onunload(.*>)/$1never$2/iU - + + Type: + + + Parameterized. + + - - 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. - + + Parameter: + + + Any user-defined string. + + + - - The last example is from the fun department: - + + 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. + + + - - -FILTER: fun Fun text replacements + + Example usage: + + + +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)} + + + + + -# Spice the daily news: -# -s/microsoft(?!\.com)/MicroSuck/ig - - - 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. - + + +limit-connect - - -# 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 - + + + Typical use: + + Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted sites + + - - 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. - + + Effect: + + + Specifies to which ports HTTP CONNECT requests are allowable. + + + - - You get the idea? - - + + 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). + + + -The Pre-defined Filters + + 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. + + + - + + + + +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 + + + + + - Note each filter is also listed in the +filter action section above. Please - keep these listings in sync. - ---> - -The distribution default.filter file contains a selection of -pre-defined filters for your convenience: - + + +limit-cookie-lifetime - js-annoyances + Typical use: + + Limit the lifetime of HTTP cookies to a couple of minutes or hours. + + + + + Effect: - 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. - - - + Overwrites the expires field in Set-Cookie server headers if it's above the specified limit. + + + + + Type: + + + Parameterized. + + + + + Parameter: + - Use with caution. This is an aggressive filter, and can break sites that - rely heavily on JavaScript. + The lifetime limit in minutes, or 0. - + - 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! + 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. - 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). + 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. - - html-annoyances + + Example usages: - - 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. + + +limit-cookie-lifetime{60} + + + + + + +prevent-compression + - content-cookies + Typical use: - 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. + Ensure that servers send the content uncompressed, so it can be + passed through filters. + + + + + 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. + Removes the Accept-Encoding header which can be used to ask for compressed transfer. - refresh tags + Type: + + + Boolean. + + + + + 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. + N/A - unsolicited-popups + Notes: - 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. + 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. - 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. + 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. - 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. + 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. - all-popups + Example usage (sections): - 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. + +# 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. - img-reorder + Type: + + + Parameterized. + + + + + Parameter: - 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. + One of the keywords: block, reset-to-request-time + and randomize - banners-by-size + Notes: - 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. + 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. - 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. + 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. - Recommended only for those who require extreme ad blocking. The default - block rules should catch 95+% of all ads without this filter enabled. + 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. - banners-by-link + Example usage: - - 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. + + # Let the browser revalidate without being tracked across sessions +{ +hide-if-modified-since{-60} \ + +overwrite-last-modified{randomize} \ + +crunch-if-none-match} +/ + + + + + +redirect + + - 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. + Redirect requests to other sites. - 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. + Convinces the browser that the requested document has been moved + to another location and the browser should get it from there. - 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. + An absolute URL or a single pcrs command. - 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. + 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 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. - + The syntax for pcrs commands is documented in the + filter file section. - - - - - 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. + 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. - quicktime-kioskmode + Example usages: - Change HTML code that embeds Quicktime objects so that kioskmode, which - prevents saving, is disabled. + # 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 + + - fun + Typical use: - Text replacements for subversive browsing fun. Make fun of your favorite - Monopolist or play buzzword bingo. + Rewrite or remove single server headers. - crude-parental + Effect: - A demonstration-only filter that shows how Privoxy - can be used to delete web content on a keyword basis. + All server headers to which this action applies are filtered on-the-fly + through the specified regular expression based substitutions. - ie-exploits + Type: + - - 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. - + Parameterized. - site-specifics + Parameter: - 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. + The name of a server-header filter, as defined in one of the + filter files. - google + Notes: - A CSS based block for Google text ads. Also removes a width limitation - and the toolbar advertisement. + 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. - - - - - yahoo - - Another CSS based block, this time for Yahoo text ads. And removes - a width limitation as well. + 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 + + - - msn + + + + + + +server-header-tagger + + + + Typical use: - Another CSS based block, this time for MSN text ads. And removes - tracking URLs, as well as a width limitation. + Enable or disable filters based on the Content-Type header. - blogspot + Effect: - 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. + 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. - - xml-to-html - - - Server-header filter to change the Content-Type from xml to html. - - - - - - html-to-xml + + Type: + - - Server-header filter to change the Content-Type from html to xml. - + Parameterized. - - no-ping + + Parameter: - Removes the non-standard ping attribute from - anchor and area HTML tags. + The name of a server-header tagger, as defined in one of the + filter files. - - hide-tor-exit-notation + + Notes: - 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. + Server-header taggers are applied to each header on its own, + and as the header isn't modified, each tagger sees + the original. - 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). + 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). - 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. + Obviously crunching based on tags created by server-header taggers + doesn't prevent the request from showing up in the server's log file. - + + - - - - - - - - - - - - - -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. - - - - - - - - - - -Contacting the Developers, Bug Reporting and Feature -Requests - - - &contacting; - - - - - - - - -Privoxy Copyright, License and History - - - ©right; - - - -License - - &license; - - - - - - -History - - &history; - - - -Authors - - &p-authors; - - - - - - - - - -See Also - - &seealso; - - - - - - -Appendix + + - -Regular Expressions - - Privoxy uses Perl-style regular - expressions in its actions - files and filter file, - through the PCRE and - - PCRS libraries. - + +session-cookies-only - - 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 ;-) - + + + Typical use: + + + Allow only temporary session cookies (for the current + browser session only). + + + - - 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. - + + Effect: + + + Deletes the expires field from Set-Cookie: + server headers. Most browsers will not store such cookies permanently and + forget them in between sessions. + + + - - 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! - + + Type: + + + Boolean. + + - - 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: - + + Parameter: + + + N/A + + + - - - . - Matches any single character, e.g. a, - A, 4, :, or @. - - + + 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. + + + - - - ? - The preceding character or expression is matched ZERO or ONE - times. Either/or. - - + + Example usage: + + + +session-cookies-only + + + + + - - - + - The preceding character or expression is matched ONE or MORE - times. - - - - - * - The preceding character or expression is matched ZERO or MORE - times. - - + + +set-image-blocker - - - \ - 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). - - + + + Typical use: + + Choose the replacement for blocked images + + - - - [ ] - 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]+. - - + + 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. + + + - - - ( ) - parentheses are used to group a sub-expression, - or multiple sub-expressions. - - + + Type: + + + Parameterized. + + - - - | - 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. - - + + 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. + + + - - 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: + + + 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} + + + + + - - /.*/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. - + + +Summary - And now something a little more complex: + 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 - /.*/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. + 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. - - 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. + 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. - - /.*/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). + 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. - - 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 :/ + 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. - More reading on Perl Compatible Regular expressions: - http://perldoc.perl.org/perlre.html + Now let's define some aliases... - For information on regular expression based substitutions and their applications - in filters, please see the filter file tutorial - in this manual. - - - - + + # 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} - - -Privoxy's Internal Pages + # 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 - - 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. + shop = -crunch-all-cookies -filter{all-popups} + # Short names for other aliases, for really lazy people ;-) + # + c0 = +crunch-all-cookies + c1 = -crunch-all-cookies - 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. + ...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 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) - - + + # 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 - - - Show information about the current configuration, including viewing and - editing of actions files: - -
- - http://config.privoxy.org/show-status - -
- - - - - Show the source code version numbers: - -
- - http://config.privoxy.org/show-version - -
- - - - - Show the browser's request headers: - -
- - http://config.privoxy.org/show-request - -
- - - - - Show which actions apply to a URL and why: - -
- - http://config.privoxy.org/show-url-info - -
- - - - - 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 - -
- - - + # 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 - These may be bookmarked for quick reference. See next. + 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. - -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). + 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. + - 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. + 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 + + - - - Privoxy - Enable - - + + The default behavior is now set. + + - - - Privoxy - Disable - - + +default.action - - - Privoxy - Toggle Privoxy (Toggles between enabled and disabled) - - + + 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. + - - - Privoxy- View Status - - - - - - Privoxy - Why? - - - + + Understanding the default.action file can + help you with your user.action, though. - Credit: The site which gave us the general idea for these bookmarklets is - www.bookmarklets.com. They - have more information about bookmarklets. + 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} + - - -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: + 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: - - - - 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. - - - - + +########################################################################## +# 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 + - 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. + 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 + - - -Troubleshooting: Anatomy of an Action + + 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: + - 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. + +{ -fast-redirects } +login.yahoo.com +edit.*.yahoo.com +.google.com +.altavista.com/.*(like|url|link):http +.altavista.com/trans.*urltext=http +.nytimes.com - 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.) + 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: + - 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. + +########################################################################## +# 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)$ - 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. + 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: - 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. + +# 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 - 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): + 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: - Matches for http://www.google.com: - - In file: default.action [ View ] [ Edit ] +########################################################################## +# Block these fine banners: +########################################################################## +{ +block{Banner ads.} } - {+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} -/ - - { -session-cookies-only } - .google.com +# 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)?)/ - { -fast-redirects } - .google.com +# Site-specific patterns (abbreviated): +# +.hitbox.com + -In file: user.action [ View ] [ Edit ] -(no matches in this file) - + + 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. - 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. + +########################################################################## +# 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 + - 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 -- / . + 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! - 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. + +# Don't filter code! +# +{ -filter } +/(.*/)?cvs +bugzilla. +developer. +wiki. +.sourceforge.net - 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, + The actual default.action is of course much more + comprehensive, but we hope this example made clear how it works. - - And finally we pull it all together in the bottom section and summarize how - Privoxy is applying all its actions - to google.com: + - +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. + - 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} + + So let's look at a few examples of things that one might typically do in + user.action: + + + - 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. + +# My user.action file. <fred@example.com> - Now another example, ad.doubleclick.net: + 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 - { +block{Domains starts with "ad"} } - ad*. +# 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 - { +block{Domain contains "ad"} } - .ad. +# 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 - { +block{Doubleclick banner server} +handle-as-image } - .[a-vx-z]*.doubleclick.net - - 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.) + 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. - 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. + +{ allow-all-cookies } + sourceforge.net + .yahoo.com + .msdn.microsoft.com + .redhat.com - 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 ... + Your bank is allergic to some filter, but you don't know which, so you disable them all: +{ -filter } + .your-home-banking-site.com + - Matches for http://www.example.net/adsl/HOWTO/: + + Some file types you may not want to filter for various reasons: + - In file: default.action [ View ] [ Edit ] + + +# Technical documentation is likely to contain strings that might +# erroneously get altered by the JavaScript-oriented filters: +# +.tldp.org +/(.*/)?selfhtml/ - {-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} } - / +# 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/ + - { +block{Path contains "ads".} +handle-as-image } - /ads - + + 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: - 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: + +{ +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/ + - { -block } - /adsl - + + 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: - 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. + +{ fragile } + .forbes.com + webmail.example.com + .mybank.com - But now what about a situation where we get no explicit matches like - we did with: + 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: - - - { +block{Path starts with "ads".} +handle-as-image } - /ads - + +{ +filter{fun} } + / # For ALL sites! - 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: + 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. - - - { shop } - .quietpc.com - .worldpay.com # for quietpc.com - .jungle.com - .scan.co.uk - .forbes.com - + 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: - { shop } is an alias that expands to - { -filter -session-cookies-only }. - Or you could do your own exception to negate filtering: - + +{ allow-ads } + .sourceforge.net + .slashdot.org + .osdn.net - - - { -filter } - # Disable ALL filter actions for sites in this section - .forbes.com - developer.ibm.com - localhost - + Note that allow-ads has been aliased to + -block, + -filter{banners-by-size}, and + -filter{banners-by-link} above. - 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. + 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. - 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). + +{ handle-as-text } + /.*\.sh$ - { 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. - - - - - { fragile } - # Handle with care: easy to break - mail.google. - mybank.example.com + 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: - - 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. + +{ +set-image-blocker{blank} } +/ # ALL sites + - - - - 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 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. - Revision 2.82 2008/08/16 09:00:52 fabiankeil - Fix example URL pattern (once more with feeling). + + 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 2.81 2008/08/16 08:51:28 fabiankeil - Update version-related entities. + + 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 2.80 2008/07/18 16:54:30 fabiankeil - Remove erroneous whitespace in documentation link. - Reported by John Chronister in #2021611. + + 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 2.79 2008/06/27 18:00:53 markm68k - remove outdated startup information for mac os x + + 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 2.78 2008/06/21 17:03:03 fabiankeil - Fix typo. + + 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 2.77 2008/06/14 13:45:22 fabiankeil - Re-add a colon I unintentionally removed a few revisions ago. + + 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 2.76 2008/06/14 13:21:28 fabiankeil - Prepare for the upcoming 3.0.9 beta release. + + 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 2.75 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: foo Replace all "foo" with "bar" + - 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. + + 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. + - Revision 2.73 2008/05/23 14:43:18 fabiankeil - Remove previously out-commented block that caused syntax problems. + + 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 2.72 2008/05/12 10:26:14 fabiankeil - Synchronize content filter descriptions with the ones in default.filter. - Revision 2.71 2008/04/10 17:37:16 fabiankeil - Actually we use "modern" POSIX 1003.2 regular - expressions in path patterns, not PCRE. + - 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. +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 2.69 2008/03/29 12:14:25 fabiankeil - Remove send-wafer and send-vanilla-wafer actions. + + s/foo/bar/ + - Revision 2.68 2008/03/28 15:13:43 fabiankeil - Remove inspect-jpegs action. + + 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 2.67 2008/03/27 18:31:21 fabiankeil - Remove kill-popups action. + + s/foo/bar/g + - Revision 2.66 2008/03/06 16:33:47 fabiankeil - If limit-connect isn't used, don't limit CONNECT requests to port 443. + + Our complete filter now looks like this: + + + FILTER: foo Replace all "foo" with "bar" +s/foo/bar/g + - 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. + + 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 2.64 2008/03/01 14:10:28 fabiankeil - Use new block syntax. Still needs some polishing. - Revision 2.63 2008/02/22 05:50:37 markm68k - fix merge problem + + +FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse - Revision 2.62 2008/02/11 11:52:23 hal9 - Fix entity ... s/&/& +# 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 2.61 2008/02/11 03:41:47 markm68k - more updates for mac os x + + 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 2.60 2008/02/11 03:40:25 markm68k - more updates for mac os x + + 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 2.59 2008/02/11 00:52:34 markm68k - reflect new changes for mac os x + + 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 2.58 2008/02/03 21:37:40 hal9 - Apply patch from Mark: s/OSX/OS X/ + + 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 2.57 2008/02/03 19:10:14 fabiankeil - Mention forward-socks5. + + 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 2.56 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. + + 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 2.55 2008/01/19 21:26:37 hal9 - Add IE7 to configuration section per Gerry. + + 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 2.54 2008/01/19 17:52:39 hal9 - Re-commit to fix various minor issues for new release. + + 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 2.53 2008/01/19 15:03:05 hal9 - Doc sources tagged for 3.0.8 release. + + We'll show you two other jobs from the JavaScript taming department, but + this time only point out the constructs of special interest: + - Revision 2.52 2008/01/17 01:49:51 hal9 - Change copyright notice for docs s/2007/2008/. All these will be rebuilt soon - enough. + + +# The status bar is for displaying link targets, not pointless blahblah +# +s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig + - Revision 2.51 2007/12/23 16:48:24 fabiankeil - Use more precise example descriptions for the mysterious domain patterns. + + \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 2.50 2007/12/08 12:44:36 fabiankeil - - Remove already commented out pre-3.0.7 changes. - - Update the "new log defaults" paragraph. + + 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 2.49 2007/12/06 18:21:55 fabiankeil - Update hide-forwarded-for-headers description. + + +# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html +# +s/(<body [^>]*)onunload(.*>)/$1never$2/iU + - Revision 2.48 2007/11/24 19:07:17 fabiankeil - - Mention request rewriting. - - Enable the conditional-forge paragraph. - - 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 2.47 2007/11/18 14:59:47 fabiankeil - A few "Note to Upgraders" updates. + + The last example is from the fun department: + - Revision 2.46 2007/11/17 17:24:44 fabiankeil - - Use new action defaults. - - Minor fixes and rewordings. + + +FILTER: fun Fun text replacements - Revision 2.45 2007/11/16 11:48:46 hal9 - Fix one typo, and add a couple of small refinements. +# Spice the daily news: +# +s/microsoft(?!\.com)/MicroSuck/ig + - Revision 2.44 2007/11/15 03:30:20 hal9 - Results of spell check. + + 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 2.43 2007/11/14 18:45:39 fabiankeil - - Mention some more contributors in the "New in this Release" list. - - Minor rewordings. + + +# 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 2.42 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 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 2.41 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). + + You get the idea? + + - 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. + - Revision 2.39 2007/11/05 02:34:49 hal9 - Various changes in preparation for the upcoming release. Much yet to be done. +The Pre-defined Filters - Revision 2.38 2007/09/22 16:01:42 fabiankeil - Update embedded show-url-info output. + - Revision 2.35 2007/08/26 14:59:49 fabiankeil - Minor rewordings and fixes. + +The distribution default.filter file contains a selection of +pre-defined filters for your convenience: + - 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. + + + 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 2.33 2007/07/27 10:57:35 hal9 - Add references for user-agent strings for hide-user-agenet + + 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 2.32 2007/06/07 12:36:22 fabiankeil - Apply Roland's 29_usermanual.dpatch to fix a bunch - of syntax errors I collected over the last months. + + 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 2.31 2007/06/02 14:01:37 fabiankeil - Start to document forward-override{}. + + 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 2.30 2007/04/25 15:10:36 fabiankeil - - Describe installation for FreeBSD. - - Start to document taggers and tag patterns. - - Don't confuse devils and daemons. + + 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 2.29 2007/04/05 11:47:51 fabiankeil - Some updates regarding header filtering, - handling of compressed content and redirect's - support for pcrs commands. + + 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 2.28 2006/12/10 23:42:48 hal9 - Fix various typos reported by Adam P. Thanks. + + 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 2.27 2006/11/14 01:57:47 hal9 - Dump all docs prior to 3.0.6 release. Various minor changes to faq and user - manual. + + 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 2.26 2006/10/24 11:16:44 hal9 - Add new filters. + + 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 2.25 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. + + 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 2.24 2006/10/03 11:13:54 hal9 - More references to the new filters. Include html this time around. + + 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 2.23 2006/10/02 22:43:53 hal9 - Contains new filter definitions from Fabian, and few other miscellaneous - touch-ups. + + 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 2.22 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. + + 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 2.21 2006/09/20 03:21:36 david__schmidt - Just the tiniest tweak. Wafer thin! + + 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 2.20 2006/09/10 14:53:54 hal9 - Results of spell check. User manual has some updates to standard.actions file - info. + + 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 2.19 2006/09/08 12:19:02 fabiankeil - Adjust hide-if-modified-since example values - to reflect the recent 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 2.18 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. + + quicktime-kioskmode + + + Change HTML code that embeds Quicktime objects so that kioskmode, which + prevents saving, is disabled. + + + - 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. + + fun + + + Text replacements for subversive browsing fun. Make fun of your favorite + Monopolist or play buzzword bingo. + + + - Revision 2.16 2006/09/02 12:49:37 hal9 - Various small updates for new actions, filterfiles, etc. + + crude-parental + + + A demonstration-only filter that shows how Privoxy + can be used to delete web content on a keyword basis. + + + - 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. + + 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 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. + + 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 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. + + google + + + A CSS based block for Google text ads. Also removes a width limitation + and the toolbar advertisement. + + + - Revision 2.12 2006/08/14 08:40:39 fabiankeil - Documented new actions that were part of - the "minor Privoxy improvements". + + yahoo + + + Another CSS based block, this time for Yahoo text ads. And removes + a width limitation as well. + + + - 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) + + msn + + + Another CSS based block, this time for MSN text ads. And removes + tracking URLs, as well as a width limitation. + + + - Revision 1.123.2.43 2005/05/23 09:59:10 hal9 - Fix typo 'loose' + + 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 1.123.2.42 2004/12/04 14:39:57 hal9 - Fix two minor typos per bug SF report. + + xml-to-html + + + Server-header filter to change the Content-Type from xml to html. + + + - Revision 1.123.2.41 2004/03/23 12:58:42 oes - Fixed an inaccuracy + + html-to-xml + + + Server-header filter to change the Content-Type from html to xml. + + + - 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. + + no-ping + + + Removes the non-standard ping attribute from + anchor and area HTML tags. + + + - Revision 1.123.2.39 2004/01/30 22:31:40 oes - Added a hint re bookmarklets to Quickstart section + + 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 1.123.2.38 2004/01/30 16:47:51 oes - Some minor clarifications + + - 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. + + - Revision 1.123.2.36 2003/12/10 02:26:26 hal9 - Changed the demoronizer filter description. + - Revision 1.123.2.35 2003/11/06 13:36:37 oes - Updated link to nightly CVS tarball - 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. - 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). + +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 1.123.2.31 2003/03/26 02:03:43 oes - Updated hard-coded copyright dates + + These templates are stored in a subdirectory of the configuration + directory called templates. On Unixish platforms, + this is typically + /etc/privoxy/templates/. + - Revision 1.123.2.30 2003/03/24 12:58:56 hal9 - Add new section on Predefined Filters. + + 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 1.123.2.29 2003/03/20 02:45:29 hal9 - More problems with \-\-chroot causing markup problems :( + + 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 1.123.2.28 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). + + 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 1.123.2.27 2003/03/18 19:37:14 oes - s/Advanced|Radical/Adventuresome/g to avoid complaints re fun filter + + +<!-- @if-unstable-start --> - Revision 1.123.2.26 2003/03/17 16:50:53 oes - Added documentation for new chroot option + ... beta warning HTML code goes here ... - Revision 1.123.2.25 2003/03/15 18:36:55 oes - Adapted to the new filters +<!-- if-unstable-end@ --> + - 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. + + 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 1.123.2.23 2002/10/21 02:32:01 hal9 - Updates to the user.action examples section. A few new ones. + + <!-- --> + - Revision 1.123.2.22 2002/10/12 00:51:53 hal9 - Add demoronizer to filter section. + + 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 1.123.2.21 2002/10/10 04:09:35 hal9 - s/Advanced/Radical/ and added very brief note. + + 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 1.123.2.20 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. + - Revision 1.123.2.19 2002/09/26 01:25:36 hal9 - More explanation on Privoxy patterns, more on content-cookies and SSL. + - Revision 1.123.2.18 2002/08/22 23:47:58 hal9 - Add 'Documentation' to Privoxy Menu shot in Configuration section to match - CGIs. - Revision 1.123.2.17 2002/08/18 01:13:05 hal9 - Spell checked (only one typo this time!). - Revision 1.123.2.16 2002/08/09 19:20:54 david__schmidt - Update to Mac OS X startup script name + - 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 +Contacting the Developers, Bug Reporting and Feature +Requests - Revision 1.123.2.14 2002/08/06 09:16:13 oes - Nits re: actions file download + + &contacting; + - Revision 1.123.2.13 2002/08/02 18:23:19 g_sauthoff - Just 2 small corrections to the Gentoo sections + - Revision 1.123.2.12 2002/08/02 18:17:21 g_sauthoff - Added 2 Gentoo sections + - 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. + +Privoxy Copyright, License and History - Revision 1.123.2.9 2002/07/11 03:40:28 david__schmidt + + ©right; + - Updated Mac OS X sections due to installation location change + +License + + &license; + + + - 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. + - Revision 1.123.2.6 2002/06/06 23:11:03 hal9 - Fix broken link. Linkchecked all docs. +History + + &history; + + - 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. +Authors + + &p-authors; + + - 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. - Revision 1.123.2.1 2002/05/26 17:04:25 hal9 - -Spellcheck, very minor edits, and sync across branches + +See Also + + &seealso; + + - 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. - Revision 1.122 2002/05/24 13:24:08 oes - Added Bookmarklet for one-click pre-filled access to show-url-info - 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). +<!-- ~~~~~ New section ~~~~~ --> +<sect1 id="appendix"><title>Appendix - 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 + + +Regular Expressions + + Privoxy uses Perl-style regular + expressions in its actions + files and filter file, + through the PCRE and + + PCRS libraries. + - Revision 1.118 2002/05/21 04:54:55 hal9 - -New Section: Quickstart to Ad Blocking - -Reformat Actions Anatomy to match new CGI layout + + 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 1.117 2002/05/17 13:56:16 oes - - Reworked & extended Templates chapter - - Small changes to Regex appendix - - #included authors.sgml into (C) and hist chapter + + 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 1.116 2002/05/17 03:23:46 hal9 - Fixing merge conflict in Quickstart section. + + 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 1.115 2002/05/16 16:25:00 oes - Extended the Filter File chapter & minor fixes + + 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 1.114 2002/05/16 09:42:50 oes - More ulink->link, added some hints to Quickstart section + + + . - Matches any single character, e.g. a, + A, 4, :, or @. + + - Revision 1.113 2002/05/15 21:07:25 oes - Extended and further commented the example actions files + + + ? - The preceding character or expression is matched ZERO or ONE + times. Either/or. + + - Revision 1.112 2002/05/15 03:57:14 hal9 - Spell check. A few minor edits here and there for better syntax and - clarification. + + + + - The preceding character or expression is matched ONE or MORE + times. + + - Revision 1.111 2002/05/14 23:01:36 oes - Fixing the fixes + + + * - The preceding character or expression is matched ZERO or MORE + times. + + - Revision 1.110 2002/05/14 19:10:45 oes - Restored alphabetical order of actions + + + \ - 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 1.109 2002/05/14 17:23:11 oes - Renamed the prevent-*-cookies actions, extended aliases section and moved it before the example AFs + + + [ ] - 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 1.108 2002/05/14 15:29:12 oes - Completed proofreading the actions chapter + + + ( ) - parentheses are used to group a sub-expression, + or multiple sub-expressions. + + - 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. + + + | - 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 1.106 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). + + 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 1.105 2002/05/05 20:26:02 hal9 - Sorting out license vs copyright in these docs. + + /.*/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 1.104 2002/05/04 08:44:45 swa - bumped version + + And now something a little more complex: + - 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. + + /.*/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 1.102 2002/05/03 17:46:00 oes - Further proofread & reactivated short build instructions + + 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 1.101 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. + + /.*/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 1.100 2002/04/29 03:05:55 hal9 - Add clarification on differences of new actions files. + + 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 1.99 2002/04/28 16:59:05 swa - more structure in starting section + + More reading on Perl Compatible Regular expressions: + http://perldoc.perl.org/perlre.html + - 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 :( + + For information on regular expression based substitutions and their applications + in filters, please see the filter file tutorial + in this manual. + + - Revision 1.97 2002/04/27 21:04:42 hal9 - -Rewrite of Actions File example. - -Add section for user-manual directive in config. + - 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). - 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 + + +Privoxy's Internal Pages - 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. + + 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 1.92 2002/04/25 18:55:13 hal9 - More catchups on new actions files, and new actions names. - Other assorted cleanups, and minor modifications. + - Revision 1.91 2002/04/24 02:39:31 hal9 - Add 'Chain of Events' section. + + 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 1.90 2002/04/23 21:41:25 hal9 - Linuxconf is deprecated on RH, substitute chkconfig. + + - Revision 1.89 2002/04/23 21:05:28 oes - Added hint for startup on Red Hat + + + 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 1.88 2002/04/23 05:37:54 hal9 - Add AmigaOS install stuff. + + + Show information about the current configuration, including viewing and + editing of actions files: + +
+ + http://config.privoxy.org/show-status + +
+ - 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 + + + Show the source code version numbers: + +
+ + http://config.privoxy.org/show-version + +
+ - Revision 1.86 2002/04/21 01:46:32 hal9 - Re-write actions section. + + + Show the browser's request headers: + +
+ + http://config.privoxy.org/show-request + +
+ - Revision 1.85 2002/04/18 21:23:23 hal9 - Fix ugly typo (mine). + + + Show which actions apply to a URL and why: + +
+ + http://config.privoxy.org/show-url-info + +
+ - Revision 1.84 2002/04/18 21:17:13 hal9 - Spell Redhat correctly (ie Red Hat). A few minor grammar corrections. + + + 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 1.83 2002/04/18 18:21:12 oes - Added RPM install detail + + - Revision 1.82 2002/04/18 12:04:50 oes - Cosmetics + + These may be bookmarked for quick reference. See next. - 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 + +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). + + + 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. + - 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 - Enable + + - Revision 1.77 2002/04/17 13:51:23 oes - Proofreading, part one + + + Privoxy - Disable + + - 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. + + + Privoxy - Toggle Privoxy (Toggles between enabled and disabled) + + - Revision 1.75 2002/04/12 02:08:48 david__schmidt - Remove OS/2 building info... it is already in the developer-manual + + + Privoxy- View Status + + + + + + Privoxy - Why? + + + + - Revision 1.74 2002/04/11 00:54:38 hal9 - Add small section on submitting actions. + + Credit: The site which gave us the general idea for these bookmarklets is + www.bookmarklets.com. They + have more information about bookmarklets. + - Revision 1.73 2002/04/10 18:45:15 swa - generated - 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. 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. + - 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 +