2 File : doc/source/p-config.sgml
4 Purpose : Used with other docs and files only.
6 Copyright (C) 2001-2018 Privoxy Developers https://www.privoxy.org/
9 ========================================================================
10 NOTE: Please read developer-manual/documentation.html before touching
11 anything in this, or other Privoxy documentation.
12 ========================================================================
15 This file contains all the config file comments and options. It used to
16 build both the user-manual config sections, and all of config (yes, the main
19 Rationale: This is broken up into two files since a file with a prolog
20 (DTD, etc) cannot be sourced as a secondary file. config.sgml is basically
21 a wrapper for this file.
25 OPTIONS: The actual options are included in this file and prefixed with
26 '@@', and processed by the Makefile to strip the '@@'. Default options
27 that should appear commented out should be listed as: '@@#OPTION'.
28 Otherwise, as '@@OPTION'. Example:
30 @@listen-address 127.0.0.1:8118
32 The Makefile does significant other processing too. The final results
33 should be checked to make sure that the perl processing does not
34 fubar something!!! Makefile processing requires w3m, fmt (shell line
38 This file is included into:
41 config (the actual Privoxy config file)
46 <!-- This part only goes into user-manual -->
48 <title>The Main Configuration File</title>
51 By default, the main configuration file is named <filename>config</filename>,
52 with the exception of Windows, where it is named <filename>config.txt</filename>.
53 Configuration lines consist of an initial keyword followed by a list of
54 values, all separated by whitespace (any number of spaces or tabs). For
59 <emphasis>confdir /etc/privoxy</emphasis>
63 Assigns the value <literal>/etc/privoxy</literal> to the option
64 <literal>confdir</literal> and thus indicates that the configuration
65 directory is named <quote>/etc/privoxy/</quote>.
69 All options in the config file except for <literal>confdir</literal> and
70 <literal>logdir</literal> are optional. Watch out in the below description
71 for what happens if you leave them unset.
75 The main config file controls all aspects of <application>Privoxy</application>'s
76 operation that are not location dependent (i.e. they apply universally, no matter
77 where you may be surfing). Like the filter and action files, the config file is
78 a plain text file and can be modified with a text editor like emacs, vim or
86 <!-- This part only goes into the config file -->
89 @@TITLE<!-- between the @@ is stripped by Makefile -->@@
90 Sample Configuration File for Privoxy &p-version;
93 Copyright (C) 2001-2018 Privoxy Developers https://www.privoxy.org/
97 ##################################################################
102 II. FORMAT OF THE CONFIGURATION FILE #
104 1. LOCAL SET-UP DOCUMENTATION #
105 2. CONFIGURATION AND LOG FILE LOCATIONS #
107 4. ACCESS CONTROL AND SECURITY #
110 7. WINDOWS GUI OPTIONS #
112 ##################################################################
120 This file holds Privoxy's main configuration. Privoxy detects
121 configuration changes automatically, so you don't have to restart it
122 unless you want to load a different configuration file.
125 The configuration will be reloaded with the first request after the
126 change was done, this request itself will still use the old configuration,
127 though. In other words: it takes two requests before you see the result of
128 your changes. Requests that are dropped due to ACL don't trigger reloads.
131 When starting Privoxy on Unix systems, give the location of this
132 file as last argument. On Windows systems, Privoxy will look for
133 this file with the name 'config.txt' in the current working directory
134 of the Privoxy process.
138 <literallayout><!-- funky spacing -->
140 II. FORMAT OF THE CONFIGURATION FILE
141 ====================================</literallayout>
144 Configuration lines consist of an initial keyword followed by a list
145 of values, all separated by whitespace (any number of spaces or
149 actionsfile default.action
152 Indicates that the actionsfile is named 'default.action'.
155 The '#' indicates a comment. Any part of a line following a '#' is
156 ignored, except if the '#' is preceded by a '\'.
159 Thus, by placing a # at the start of an existing configuration line,
160 you can make it a comment and it will be treated as if it weren't there.
161 This is called "commenting out" an option and can be useful. Removing
162 the # again is called "uncommenting".
165 Note that commenting out an option and leaving it at its default
166 are two completely different things! Most options behave very
167 differently when unset. See the "Effect if unset" explanation
168 in each option's description for details.
171 Long lines can be continued on the next line by using a `\' as
177 <!-- ************************************************ -->
178 <!-- The following is common to both outputs (mostly) -->
179 <!-- ************************************************ -->
183 <!-- ~~~~~ New section ~~~~~ -->
184 <sect2 id="local-set-up">
185 <title>Local Set-up Documentation</title>
188 If you intend to operate <application>Privoxy</application> for more users
189 than just yourself, it might be a good idea to let them know how to reach
190 you, what you block and why you do that, your policies, etc.
194 <!-- ~~~~~ New section ~~~~~ -->
195 <sect3 renderas="sect4" id="user-manual"><title>user-manual</title>
198 <term>Specifies:</term>
201 Location of the <application>Privoxy</application> User Manual.
206 <term>Type of value:</term>
208 <para>A fully qualified URI</para>
212 <term>Default value:</term>
214 <para><emphasis>Unset</emphasis></para>
218 <term>Effect if unset:</term>
221 <ulink url="https://www.privoxy.org/user-manual/">https://www.privoxy.org/<replaceable class="parameter">version</replaceable>/user-manual/</ulink>
222 will be used, where <replaceable class="parameter">version</replaceable> is the <application>Privoxy</application> version.
230 The User Manual URI is the single best source of information on
231 <application>Privoxy</application>, and is used for help links from some
232 of the internal CGI pages. The manual itself is normally packaged with the
233 binary distributions, so you probably want to set this to a locally
241 Unix, in local filesystem (may not work with all browsers):
243 <screen> user-manual file:///usr/share/doc/privoxy-&p-version;/user-manual/</screen>
245 Windows, in local filesystem, <emphasis>must</emphasis> use forward slash notation:
247 <screen> user-manual file:/c:/some-dir/privoxy-&p-version;/user-manual/</screen>
249 Windows, UNC notation (with forward slashes):
251 <screen> user-manual file://///some-server/some-path/privoxy-&p-version;/user-manual/</screen>
254 The best all purpose solution is simply to put the full local
255 <literal>PATH</literal> to where the <citetitle>User Manual</citetitle> is
258 <screen> user-manual /usr/share/doc/privoxy/user-manual</screen>
260 The User Manual is then available to anyone with access to
261 <application>Privoxy</application>, by following the built-in URL:
262 <literal>http://config.privoxy.org/user-manual/</literal>
263 (or the shortcut: <literal>http://p.p/user-manual/</literal>).
266 If the documentation is not on the local system, it can be accessed
267 from a remote server, as:
269 <screen> user-manual http://example.com/privoxy/user-manual/</screen>
271 <!-- this gets hammered in conversion to config. Text repeated below. -->
274 If set, this option should be <emphasis>the first option in the config
275 file</emphasis>, because it is used while the config file is being read
288 If set, this option should be the first option in the config
289 file, because it is used while the config file is being read.
298 <![%config-file;[<literallayout>@@#user-manual https://www.privoxy.org/user-manual/</literallayout>]]>
302 <!-- ~~~~~ New section ~~~~~ -->
303 <sect3 renderas="sect4" id="trust-info-url"><title>trust-info-url</title>
307 <term>Specifies:</term>
310 A URL to be displayed in the error page that users will see if access to an untrusted page is denied.
315 <term>Type of value:</term>
321 <term>Default value:</term>
323 <para><emphasis>Unset</emphasis></para>
327 <term>Effect if unset:</term>
330 No links are displayed on the "untrusted" error page.
338 The value of this option only matters if the experimental trust mechanism has been
339 activated. (See <link linkend="trustfile"><emphasis>trustfile</emphasis></link> below.)
342 If you use the trust mechanism, it is a good idea to write up some on-line
343 documentation about your trust policy and to specify the URL(s) here.
344 Use multiple times for multiple URLs.
347 The URL(s) should be added to the trustfile as well, so users don't end up
348 locked out from the information on why they were locked out in the first place!
354 <![%config-file;[<literallayout>@@#trust-info-url http://www.example.com/why_we_block.html</literallayout>]]>
355 <![%config-file;[<literallayout>@@#trust-info-url http://www.example.com/what_we_allow.html</literallayout>]]>
359 <!-- ~~~~~ New section ~~~~~ -->
360 <sect3 renderas="sect4" id="admin-address"><title>admin-address</title>
364 <term>Specifies:</term>
367 An email address to reach the <application>Privoxy</application> administrator.
372 <term>Type of value:</term>
374 <para>Email address</para>
378 <term>Default value:</term>
380 <para><emphasis>Unset</emphasis></para>
384 <term>Effect if unset:</term>
387 No email address is displayed on error pages and the CGI user interface.
395 If both <literal>admin-address</literal> and <literal>proxy-info-url</literal>
396 are unset, the whole "Local Privoxy Support" box on all generated pages will
403 <![%config-file;[<literallayout>@@#admin-address privoxy-admin@example.com</literallayout>]]>
407 <!-- ~~~~~ New section ~~~~~ -->
408 <sect3 renderas="sect4" id="proxy-info-url"><title>proxy-info-url</title>
412 <term>Specifies:</term>
415 A URL to documentation about the local <application>Privoxy</application> setup,
416 configuration or policies.
421 <term>Type of value:</term>
427 <term>Default value:</term>
429 <para><emphasis>Unset</emphasis></para>
433 <term>Effect if unset:</term>
436 No link to local documentation is displayed on error pages and the CGI user interface.
444 If both <literal>admin-address</literal> and <literal>proxy-info-url</literal>
445 are unset, the whole "Local Privoxy Support" box on all generated pages will
449 This URL shouldn't be blocked ;-)
455 <![%config-file;[<literallayout>@@#proxy-info-url http://www.example.com/proxy-service.html</literallayout>]]>
459 <!-- ~ End section ~ -->
463 <!-- ~~~~~ New section ~~~~~ -->
465 <sect2 id="conf-log-loc">
466 <title>Configuration and Log File Locations</title>
469 <application>Privoxy</application> can (and normally does) use a number of
470 other files for additional configuration, help and logging.
471 This section of the configuration file tells <application>Privoxy</application>
472 where to find those other files.
476 The user running <application>Privoxy</application>, must have read
477 permission for all configuration files, and write permission to any files
478 that would be modified, such as log files and actions files.
482 <!-- ~~~~~ New section ~~~~~ -->
483 <sect3 renderas="sect4" id="confdir"><title>confdir</title>
487 <term>Specifies:</term>
489 <para>The directory where the other configuration files are located.</para>
493 <term>Type of value:</term>
495 <para>Path name</para>
499 <term>Default value:</term>
501 <para>/etc/privoxy (Unix) <emphasis>or</emphasis> <application>Privoxy</application> installation dir (Windows) </para>
505 <term>Effect if unset:</term>
507 <para><emphasis>Mandatory</emphasis></para>
514 No trailing <quote><literal>/</literal></quote>, please.
520 <![%config-file;[<literallayout>@@confdir .</literallayout>]]>
523 <!-- ~~~~~ New section ~~~~~ -->
524 <sect3 renderas="sect4" id="templdir"><title>templdir</title>
528 <term>Specifies:</term>
530 <para>An alternative directory where the templates are loaded from.</para>
534 <term>Type of value:</term>
536 <para>Path name</para>
540 <term>Default value:</term>
546 <term>Effect if unset:</term>
548 <para>The templates are assumed to be located in confdir/template.</para>
555 <application>Privoxy's</application> original templates are usually
556 overwritten with each update. Use this option to relocate customized
557 templates that should be kept. As template variables might change
558 between updates, you shouldn't expect templates to work with
559 <application>Privoxy</application> releases other than the one
560 they were part of, though.
566 <![%config-file;[<literallayout>@@#templdir .</literallayout>]]>
570 <!-- ~~~~~ New section ~~~~~ -->
571 <sect3 renderas="sect4" id="temporary-directory"><title>temporary-directory</title>
575 <term>Specifies:</term>
577 <para>A directory where Privoxy can create temporary files.</para>
581 <term>Type of value:</term>
583 <para>Path name</para>
587 <term>Default value:</term>
593 <term>Effect if unset:</term>
595 <para>No temporary files are created, external filters don't work.</para>
602 To execute <literal><ulink url="actions-file.html#EXTERNAL-FILTER">external filters</ulink></literal>,
603 <application>Privoxy</application> has to create temporary files.
604 This directive specifies the directory the temporary files should
608 It should be a directory only <application>Privoxy</application>
609 (and trusted users) can access.
615 <![%config-file;[<literallayout>@@#temporary-directory .</literallayout>]]>
619 <!-- ~~~~~ New section ~~~~~ -->
620 <sect3 renderas="sect4" id="logdir"><title>logdir</title>
624 <term>Specifies:</term>
627 The directory where all logging takes place
628 (i.e. where the <filename>logfile</filename> is located).
633 <term>Type of value:</term>
635 <para>Path name</para>
639 <term>Default value:</term>
641 <para>/var/log/privoxy (Unix) <emphasis>or</emphasis> <application>Privoxy</application> installation dir (Windows) </para>
645 <term>Effect if unset:</term>
647 <para><emphasis>Mandatory</emphasis></para>
654 No trailing <quote><literal>/</literal></quote>, please.
660 <![%config-file;[<literallayout>@@logdir .</literallayout>]]>
664 <!-- ~~~~~ New section ~~~~~ -->
665 <sect3 renderas="sect4" id="actionsfile"><title>
668 <anchor id="default.action">
669 <anchor id="standard.action">
670 <anchor id="user.action">
671 <!-- Note: slightly modified this section 04/28/02, hal. See NOTE. -->
674 <term>Specifies:</term>
677 The <link linkend="actions-file">actions file(s)</link> to use
682 <term>Type of value:</term>
684 <para>Complete file name, relative to <literal>confdir</literal></para>
688 <term>Default values:</term>
692 <msgtext><literallayout> match-all.action # Actions that are applied to all sites and maybe overruled later on.</literallayout></msgtext>
695 <msgtext><literallayout> default.action # Main actions file</literallayout></msgtext>
698 <msgtext><literallayout> user.action # User customizations</literallayout></msgtext>
704 <term>Effect if unset:</term>
707 No actions are taken at all. More or less neutral proxying.
715 Multiple <literal>actionsfile</literal> lines are permitted, and are in fact recommended!
718 The default values are <filename>default.action</filename>, which is the
719 <quote>main</quote> actions file maintained by the developers, and
720 <filename>user.action</filename>, where you can make your personal additions.
723 Actions files contain all the per site and per URL configuration for
724 ad blocking, cookie management, privacy considerations, etc.
730 <!-- NOTE: alternate markup to make a simpler list doesn't work due to -->
731 <!-- html -> text conversion, blah -->
732 <![%config-file;[<literallayout>@@actionsfile match-all.action # Actions that are applied to all sites and maybe overruled later on.</literallayout>]]>
733 <![%config-file;[<literallayout>@@actionsfile default.action # Main actions file</literallayout>]]>
735 XXX: Like user.filter, user.action should probably be commented out
736 by default as not all packages install it into the default directory.
739 <![%config-file;[<literallayout>@@actionsfile user.action # User customizations</literallayout>]]>
742 <!-- ~~~~~ New section ~~~~~ -->
743 <sect3 renderas="sect4" id="filterfile"><title>filterfile</title>
744 <anchor id="default.filter">
747 <term>Specifies:</term>
750 The <link linkend="filter-file">filter file(s)</link> to use
755 <term>Type of value:</term>
757 <para>File name, relative to <literal>confdir</literal></para>
761 <term>Default value:</term>
763 <para>default.filter (Unix) <emphasis>or</emphasis> default.filter.txt (Windows)</para>
767 <term>Effect if unset:</term>
770 No textual content filtering takes place, i.e. all
771 <literal>+<link linkend="filter">filter</link>{<replaceable class="parameter">name</replaceable>}</literal>
772 actions in the actions files are turned neutral.
780 Multiple <literal>filterfile</literal> lines are permitted.
783 The <link linkend="filter-file">filter files</link> contain content modification
784 rules that use <link linkend="regex">regular expressions</link>. These rules permit
785 powerful changes on the content of Web pages, and optionally the headers
786 as well, e.g., you could try to disable your favorite JavaScript annoyances,
787 re-write the actual displayed text, or just have some fun
788 playing buzzword bingo with web pages.
792 <literal>+<link linkend="filter">filter</link>{<replaceable class="parameter">name</replaceable>}</literal>
793 actions rely on the relevant filter (<replaceable class="parameter">name</replaceable>)
794 to be defined in a filter file!
797 A pre-defined filter file called <filename>default.filter</filename> that contains
798 a number of useful filters for common problems is included in the distribution.
799 See the section on the <literal><link linkend="filter">filter</link></literal>
803 It is recommended to place any locally adapted filters into a separate
804 file, such as <filename>user.filter</filename>.
810 <![%config-file;[<literallayout>@@filterfile default.filter</literallayout>]]>
811 <![%config-file;[<literallayout>@@filterfile user.filter # User customizations</literallayout>]]>
815 <!-- ~~~~~ New section ~~~~~ -->
816 <sect3 renderas="sect4" id="logfile"><title>logfile</title>
820 <term>Specifies:</term>
828 <term>Type of value:</term>
830 <para>File name, relative to <literal>logdir</literal></para>
834 <term>Default value:</term>
836 <para><emphasis>Unset (commented out)</emphasis>. When activated: logfile (Unix) <emphasis>or</emphasis> privoxy.log (Windows).</para>
840 <term>Effect if unset:</term>
843 No logfile is written.
851 The logfile is where all logging and error messages are written. The level
852 of detail and number of messages are set with the <literal>debug</literal>
853 option (see below). The logfile can be useful for tracking down a problem with
854 <application>Privoxy</application> (e.g., it's not blocking an ad you
855 think it should block) and it can help you to monitor what your browser
859 Depending on the debug options below, the logfile may be a privacy risk
860 if third parties can get access to it. As most users will never look
861 at it, <application>Privoxy</application> only logs fatal errors by default.
864 For most troubleshooting purposes, you will have to change that,
865 please refer to the debugging section for details.
868 Any log files must be writable by whatever user <application>Privoxy</application>
869 is being run as (on Unix, default user id is <quote>privoxy</quote>).
872 To prevent the logfile from growing indefinitely, it is recommended to
873 periodically rotate or shorten it. Many operating systems support log
874 rotation out of the box, some require additional software to do it.
875 For details, please refer to the documentation for your operating system.
881 <![%config-file;[<literallayout>@@logfile logfile</literallayout>]]>
885 <!-- ~~~~~ New section ~~~~~ -->
886 <sect3 renderas="sect4" id="trustfile"><title>trustfile</title>
889 <term>Specifies:</term>
892 The name of the trust file to use
897 <term>Type of value:</term>
899 <para>File name, relative to <literal>confdir</literal></para>
903 <term>Default value:</term>
905 <para><emphasis>Unset (commented out)</emphasis>. When activated: trust (Unix) <emphasis>or</emphasis> trust.txt (Windows)</para>
909 <term>Effect if unset:</term>
912 The entire trust mechanism is disabled.
920 The trust mechanism is an experimental feature for building white-lists and should
921 be used with care. It is <emphasis>NOT</emphasis> recommended for the casual user.
924 If you specify a trust file, <application>Privoxy</application> will only allow
925 access to sites that are specified in the trustfile. Sites can be listed
929 Prepending a <literal>~</literal> character limits access to this site
930 only (and any sub-paths within this site), e.g.
931 <literal>~www.example.com</literal> allows access to
932 <literal>~www.example.com/features/news.html</literal>, etc.
935 Or, you can designate sites as <emphasis>trusted referrers</emphasis>, by
936 prepending the name with a <literal>+</literal> character. The effect is that
937 access to untrusted sites will be granted -- but only if a link from this
938 trusted referrer was used to get there. The link target will then be added
939 to the <quote>trustfile</quote> so that future, direct accesses will be
940 granted. Sites added via this mechanism do not become trusted referrers
941 themselves (i.e. they are added with a <literal>~</literal> designation).
942 There is a limit of 512 such entries, after which new entries will not be
946 If you use the <literal>+</literal> operator in the trust file, it may grow
947 considerably over time.
950 It is recommended that <application>Privoxy</application> be compiled with
951 the <literal>--disable-force</literal>, <literal>--disable-toggle</literal> and
952 <literal> --disable-editor</literal> options, if this feature is to be
956 Possible applications include limiting Internet access for children.
963 <![%config-file;[<literallayout>@@#trustfile trust</literallayout>]]>
967 <!-- ~ End section ~ -->
969 <!-- ~~~~~ New section ~~~~~ -->
970 <sect2 id="debugging">
971 <title>Debugging</title>
974 These options are mainly useful when tracing a problem.
975 Note that you might also want to invoke
976 <application>Privoxy</application> with the <literal>--no-daemon</literal>
977 command line option when debugging.
980 <sect3 renderas="sect4" id="debug"><title>debug</title>
984 <term>Specifies:</term>
987 Key values that determine what information gets logged.
992 <term>Type of value:</term>
994 <para>Integer values</para>
998 <term>Default value:</term>
1000 <para>0 (i.e.: only fatal errors (that cause Privoxy to exit) are logged)</para>
1004 <term>Effect if unset:</term>
1007 Default value is used (see above).
1015 The available debug levels are:
1018 debug 1 # Log the destination for each request &my-app; let through. See also debug 1024.
1019 debug 2 # show each connection status
1020 debug 4 # show I/O status
1021 debug 8 # show header parsing
1022 debug 16 # log all data written to the network
1023 debug 32 # debug force feature
1024 debug 64 # debug regular expression filters
1025 debug 128 # debug redirects
1026 debug 256 # debug GIF de-animation
1027 debug 512 # Common Log Format
1028 debug 1024 # Log the destination for requests &my-app; didn't let through, and the reason why.
1029 debug 2048 # CGI user interface
1030 debug 4096 # Startup banner and warnings.
1031 debug 8192 # Non-fatal errors
1032 debug 32768 # log all data read from the network
1033 debug 65536 # Log the applying actions
1036 To select multiple debug levels, you can either add them or use
1037 multiple <literal>debug</literal> lines.
1040 A debug level of 1 is informative because it will show you each request
1041 as it happens. <emphasis>1, 1024, 4096 and 8192 are recommended</emphasis>
1042 so that you will notice when things go wrong. The other levels are
1043 probably only of interest if you are hunting down a specific problem.
1044 They can produce a hell of an output (especially 16).
1047 If you are used to the more verbose settings, simply enable the debug lines
1051 If you want to use pure CLF (Common Log Format), you should set <quote>debug
1052 512</quote> <emphasis>ONLY</emphasis> and not enable anything else.
1055 <application>Privoxy</application> has a hard-coded limit for the
1056 length of log messages. If it's reached, messages are logged truncated
1057 and marked with <quote>... [too long, truncated]</quote>.
1060 Please don't file any support requests without trying to reproduce
1061 the problem with increased debug level first. Once you read the log
1062 messages, you may even be able to solve the problem on your own.
1068 <![%config-file;[<literallayout>@@#debug 1 # Log the destination for each request &my-app; let through.</literallayout>]]>
1069 <![%config-file;[<literallayout>@@#debug 1024 # Log the destination for requests &my-app; didn't let through, and the reason why.</literallayout>]]>
1070 <![%config-file;[<literallayout>@@#debug 4096 # Startup banner and warnings</literallayout>]]>
1071 <![%config-file;[<literallayout>@@#debug 8192 # Non-fatal errors</literallayout>]]>
1075 <!-- ~~~~~ New section ~~~~~ -->
1076 <sect3 renderas="sect4" id="single-threaded"><title>single-threaded</title>
1080 <term>Specifies:</term>
1083 Whether to run only one server thread.
1088 <term>Type of value:</term>
1090 <para><emphasis>1 or 0</emphasis></para>
1094 <term>Default value:</term>
1096 <para><emphasis>0</emphasis></para>
1100 <term>Effect if unset:</term>
1103 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability to
1104 serve multiple requests simultaneously.
1112 This option is only there for debugging purposes.
1113 <emphasis>It will drastically reduce performance.</emphasis>
1119 <![%config-file;[<literallayout>@@#single-threaded 1</literallayout>]]>
1122 <!-- ~~~~~ New section ~~~~~ -->
1123 <sect3 renderas="sect4" id="hostname"><title>hostname</title>
1127 <term>Specifies:</term>
1130 The hostname shown on the CGI pages.
1135 <term>Type of value:</term>
1141 <term>Default value:</term>
1143 <para><emphasis>Unset</emphasis></para>
1147 <term>Effect if unset:</term>
1150 The hostname provided by the operating system is used.
1158 On some misconfigured systems resolving the hostname fails or
1159 takes too much time and slows Privoxy down. Setting a fixed hostname
1160 works around the problem.
1163 In other circumstances it might be desirable to show a hostname
1164 other than the one returned by the operating system. For example
1165 if the system has several different hostnames and you don't want
1166 to use the first one.
1169 Note that Privoxy does not validate the specified hostname value.
1175 <![%config-file;[<literallayout>@@#hostname hostname.example.org</literallayout>]]>
1180 <!-- ~ End section ~ -->
1183 <!-- ~~~~~ New section ~~~~~ -->
1184 <sect2 id="access-control">
1185 <title>Access Control and Security</title>
1188 This section of the config file controls the security-relevant aspects
1189 of <application>Privoxy</application>'s configuration.
1193 <!-- ~~~~~ New section ~~~~~ -->
1194 <sect3 renderas="sect4" id="listen-address"><title>listen-address</title>
1198 <term>Specifies:</term>
1201 The address and TCP port on which <application>Privoxy</application> will
1202 listen for client requests.
1207 <term>Type of value:</term>
1209 <para>[<replaceable class="parameter">IP-Address</replaceable>]:<replaceable class="parameter">Port</replaceable></para>
1210 <para>[<replaceable class="parameter">Hostname</replaceable>]:<replaceable class="parameter">Port</replaceable></para>
1215 <term>Default value:</term>
1217 <para>127.0.0.1:8118</para>
1221 <term>Effect if unset:</term>
1224 Bind to 127.0.0.1 (IPv4 localhost), port 8118. This is suitable and
1225 recommended for home users who run <application>Privoxy</application> on
1226 the same machine as their browser.
1234 You will need to configure your browser(s) to this proxy address and port.
1237 If you already have another service running on port 8118, or if you want to
1238 serve requests from other machines (e.g. on your local network) as well, you
1239 will need to override the default.
1242 You can use this statement multiple times to make
1243 <application>Privoxy</application> listen on more ports or more
1244 <abbrev>IP</abbrev> addresses. Suitable if your operating system does not
1245 support sharing <abbrev>IPv6</abbrev> and <abbrev>IPv4</abbrev> protocols
1249 If a hostname is used instead of an IP address, <application>Privoxy</application>
1250 will try to resolve it to an IP address and if there are multiple, use the first
1254 If the address for the hostname isn't already known on the system
1255 (for example because it's in /etc/hostname), this may result in DNS
1259 If the specified address isn't available on the system, or if the
1260 hostname can't be resolved, <application>Privoxy</application>
1264 IPv6 addresses containing colons have to be quoted by brackets.
1265 They can only be used if <application>Privoxy</application> has
1266 been compiled with IPv6 support. If you aren't sure if your version
1267 supports it, have a look at
1268 <literal>http://config.privoxy.org/show-status</literal>.
1271 Some operating systems will prefer IPv6 to IPv4 addresses even if the
1272 system has no IPv6 connectivity which is usually not expected by the user.
1273 Some even rely on DNS to resolve localhost which mean the "localhost" address
1274 used may not actually be local.
1277 It is therefore recommended to explicitly configure the intended IP address
1278 instead of relying on the operating system, unless there's a strong reason not to.
1281 If you leave out the address, <application>Privoxy</application> will bind to all
1282 IPv4 interfaces (addresses) on your machine and may become reachable from the
1283 Internet and/or the local network. Be aware that some GNU/Linux distributions
1284 modify that behaviour without updating the documentation. Check for non-standard
1285 patches if your <application>Privoxy</application> version behaves differently.
1288 If you configure <application>Privoxy</application> to be reachable from the
1289 network, consider using <link linkend="acls">access control lists</link>
1290 (ACL's, see below), and/or a firewall.
1293 If you open <application>Privoxy</application> to untrusted users, you will
1294 also want to make sure that the following actions are disabled: <literal><link
1295 linkend="enable-edit-actions">enable-edit-actions</link></literal> and
1296 <literal><link linkend="enable-remote-toggle">enable-remote-toggle</link></literal>
1301 <term>Example:</term>
1304 Suppose you are running <application>Privoxy</application> on
1305 a machine which has the address 192.168.0.1 on your local private network
1306 (192.168.0.0) and has another outside connection with a different address.
1307 You want it to serve requests from inside only:
1310 listen-address 192.168.0.1:8118
1313 Suppose you are running <application>Privoxy</application> on an
1314 IPv6-capable machine and you want it to listen on the IPv6 address
1315 of the loopback device:
1318 listen-address [::1]:8118
1324 <![%config-file;[<literallayout>@@listen-address 127.0.0.1:8118</literallayout>]]>
1328 <!-- ~~~~~ New section ~~~~~ -->
1329 <sect3 renderas="sect4" id="toggle"><title>toggle</title>
1333 <term>Specifies:</term>
1336 Initial state of "toggle" status
1341 <term>Type of value:</term>
1347 <term>Default value:</term>
1353 <term>Effect if unset:</term>
1356 Act as if toggled on
1364 If set to 0, <application>Privoxy</application> will start in
1365 <quote>toggled off</quote> mode, i.e. mostly behave like a normal,
1366 content-neutral proxy with both ad blocking and content filtering
1367 disabled. See <literal>enable-remote-toggle</literal> below.
1373 <![%config-file;[<literallayout>@@toggle 1</literallayout>]]>
1377 <!-- ~~~~~ New section ~~~~~ -->
1378 <sect3 renderas="sect4" id="enable-remote-toggle"><title>enable-remote-toggle</title>
1381 <term>Specifies:</term>
1384 Whether or not the <ulink url="http://config.privoxy.org/toggle">web-based toggle
1385 feature</ulink> may be used
1390 <term>Type of value:</term>
1396 <term>Default value:</term>
1402 <term>Effect if unset:</term>
1405 The web-based toggle feature is disabled.
1413 When toggled off, <application>Privoxy</application> mostly acts like a normal,
1414 content-neutral proxy, i.e. doesn't block ads or filter content.
1417 Access to the toggle feature can <emphasis>not</emphasis> be
1418 controlled separately by <quote>ACLs</quote> or HTTP authentication,
1419 so that everybody who can access <application>Privoxy</application> (see
1420 <quote>ACLs</quote> and <literal>listen-address</literal> above) can
1421 toggle it for all users. So this option is <emphasis>not recommended</emphasis>
1422 for multi-user environments with untrusted users.
1425 Note that malicious client side code (e.g Java) is also
1426 capable of using this option.
1429 As a lot of <application>Privoxy</application> users don't read
1430 documentation, this feature is disabled by default.
1433 Note that you must have compiled <application>Privoxy</application> with
1434 support for this feature, otherwise this option has no effect.
1440 <![%config-file;[<literallayout>@@enable-remote-toggle 0</literallayout>]]>
1444 <!-- ~~~~~ New section ~~~~~ -->
1445 <sect3 renderas="sect4" id="enable-remote-http-toggle"><title>enable-remote-http-toggle</title>
1448 <term>Specifies:</term>
1451 Whether or not Privoxy recognizes special HTTP headers to change its behaviour.
1456 <term>Type of value:</term>
1462 <term>Default value:</term>
1468 <term>Effect if unset:</term>
1471 Privoxy ignores special HTTP headers.
1479 When toggled on, the client can change <application>Privoxy's</application>
1480 behaviour by setting special HTTP headers. Currently the only supported
1481 special header is <quote>X-Filter: No</quote>, to disable filtering for
1482 the ongoing request, even if it is enabled in one of the action files.
1485 This feature is disabled by default. If you are using
1486 <application>Privoxy</application> in a environment with trusted clients,
1487 you may enable this feature at your discretion. Note that malicious client
1488 side code (e.g Java) is also capable of using this feature.
1491 This option will be removed in future releases as it has been obsoleted
1492 by the more general header taggers.
1498 <![%config-file;[<literallayout>@@enable-remote-http-toggle 0</literallayout>]]>
1502 <!-- ~~~~~ New section ~~~~~ -->
1503 <sect3 renderas="sect4" id="enable-edit-actions"><title>enable-edit-actions</title>
1506 <term>Specifies:</term>
1509 Whether or not the <ulink url="http://config.privoxy.org/show-status">web-based actions
1510 file editor</ulink> may be used
1515 <term>Type of value:</term>
1521 <term>Default value:</term>
1527 <term>Effect if unset:</term>
1530 The web-based actions file editor is disabled.
1538 Access to the editor can <emphasis>not</emphasis> be
1539 controlled separately by <quote>ACLs</quote> or HTTP authentication,
1540 so that everybody who can access <application>Privoxy</application> (see
1541 <quote>ACLs</quote> and <literal>listen-address</literal> above) can
1542 modify its configuration for all users.
1545 This option is <emphasis>not recommended</emphasis> for environments
1546 with untrusted users and as a lot of <application>Privoxy</application>
1547 users don't read documentation, this feature is disabled by default.
1550 Note that malicious client side code (e.g Java) is also
1551 capable of using the actions editor and you shouldn't enable
1552 this options unless you understand the consequences and are
1553 sure your browser is configured correctly.
1556 Note that you must have compiled <application>Privoxy</application> with
1557 support for this feature, otherwise this option has no effect.
1563 <![%config-file;[<literallayout>@@enable-edit-actions 0</literallayout>]]>
1567 <sect3 renderas="sect4" id="enforce-blocks"><title>enforce-blocks</title>
1570 <term>Specifies:</term>
1573 Whether the user is allowed to ignore blocks and can <quote>go there anyway</quote>.
1578 <term>Type of value:</term>
1581 <replaceable>0 or 1</replaceable>
1586 <term>Default value:</term>
1588 <para><emphasis>0</emphasis></para>
1592 <term>Effect if unset:</term>
1595 Blocks are not enforced.
1603 <application>Privoxy</application> is mainly used to block and filter
1604 requests as a service to the user, for example to block ads and other
1605 junk that clogs the pipes. <application>Privoxy's</application> configuration
1606 isn't perfect and sometimes innocent pages are blocked. In this situation it
1607 makes sense to allow the user to enforce the request and have
1608 <application>Privoxy</application> ignore the block.
1611 In the default configuration <application>Privoxy's</application>
1612 <quote>Blocked</quote> page contains a <quote>go there anyway</quote>
1613 link to adds a special string (the force prefix) to the request URL.
1614 If that link is used, <application>Privoxy</application> will
1615 detect the force prefix, remove it again and let the request pass.
1618 Of course <application>Privoxy</application> can also be used to enforce
1619 a network policy. In that case the user obviously should not be able to
1620 bypass any blocks, and that's what the <quote>enforce-blocks</quote>
1621 option is for. If it's enabled, <application>Privoxy</application> hides
1622 the <quote>go there anyway</quote> link. If the user adds the force
1623 prefix by hand, it will not be accepted and the circumvention attempt
1629 <term>Examples:</term>
1637 <![%config-file;[<literallayout>@@enforce-blocks 0</literallayout>]]>
1641 <!-- ~~~~~ New section ~~~~~ -->
1642 <sect3 renderas="sect4" id="acls"><title>
1643 ACLs: permit-access and deny-access</title>
1644 <anchor id="permit-access">
1645 <anchor id="deny-access">
1649 <term>Specifies:</term>
1652 Who can access what.
1657 <term>Type of value:</term>
1660 <replaceable class="parameter">src_addr</replaceable>[:<replaceable class="parameter">port</replaceable>][/<replaceable class="parameter">src_masklen</replaceable>]
1661 [<replaceable class="parameter">dst_addr</replaceable>[:<replaceable class="parameter">port</replaceable>][/<replaceable class="parameter">dst_masklen</replaceable>]]
1664 Where <replaceable class="parameter">src_addr</replaceable> and
1665 <replaceable class="parameter">dst_addr</replaceable> are IPv4 addresses in dotted decimal notation or valid
1666 DNS names, <replaceable class="parameter">port</replaceable> is a port
1667 number, and <replaceable class="parameter">src_masklen</replaceable> and
1668 <replaceable class="parameter">dst_masklen</replaceable> are subnet masks in CIDR notation, i.e. integer
1669 values from 2 to 30 representing the length (in bits) of the network address. The masks and the whole
1670 destination part are optional.
1673 If your system implements
1674 <ulink url="http://tools.ietf.org/html/rfc3493">RFC 3493</ulink>, then
1675 <replaceable class="parameter">src_addr</replaceable> and <replaceable
1676 class="parameter">dst_addr</replaceable> can be IPv6 addresses delimeted by
1677 brackets, <replaceable class="parameter">port</replaceable> can be a number
1678 or a service name, and
1679 <replaceable class="parameter">src_masklen</replaceable> and
1680 <replaceable class="parameter">dst_masklen</replaceable> can be a number
1686 <term>Default value:</term>
1688 <para><emphasis>Unset</emphasis></para>
1690 If no <replaceable class="parameter">port</replaceable> is specified,
1691 any port will match. If no <replaceable class="parameter">src_masklen</replaceable> or
1692 <replaceable class="parameter">src_masklen</replaceable> is given, the complete IP
1693 address has to match (i.e. 32 bits for IPv4 and 128 bits for IPv6).
1698 <term>Effect if unset:</term>
1701 Don't restrict access further than implied by <literal>listen-address</literal>
1709 Access controls are included at the request of ISPs and systems
1710 administrators, and <emphasis>are not usually needed by individual users</emphasis>.
1711 For a typical home user, it will normally suffice to ensure that
1712 <application>Privoxy</application> only listens on the localhost
1713 (127.0.0.1) or internal (home) network address by means of the
1714 <link linkend="listen-address"><emphasis>listen-address</emphasis></link>
1718 Please see the warnings in the FAQ that <application>Privoxy</application>
1719 is not intended to be a substitute for a firewall or to encourage anyone
1720 to defer addressing basic security weaknesses.
1723 Multiple ACL lines are OK.
1724 If any ACLs are specified, <application>Privoxy</application> only talks
1725 to IP addresses that match at least one <literal>permit-access</literal> line
1726 and don't match any subsequent <literal>deny-access</literal> line. In other words, the
1727 last match wins, with the default being <literal>deny-access</literal>.
1730 If <application>Privoxy</application> is using a forwarder (see <literal>forward</literal> below)
1731 for a particular destination URL, the <replaceable class="parameter">dst_addr</replaceable>
1732 that is examined is the address of the forwarder and <emphasis>NOT</emphasis> the address
1733 of the ultimate target. This is necessary because it may be impossible for the local
1734 <application>Privoxy</application> to determine the IP address of the
1735 ultimate target (that's often what gateways are used for).
1738 You should prefer using IP addresses over DNS names, because the address lookups take
1739 time. All DNS names must resolve! You can <emphasis>not</emphasis> use domain patterns
1740 like <quote>*.org</quote> or partial domain names. If a DNS name resolves to multiple
1741 IP addresses, only the first one is used.
1744 Some systems allow IPv4 clients to connect to IPv6 server sockets.
1745 Then the client's IPv4 address will be translated by the system into
1746 IPv6 address space with special prefix ::ffff:0:0/96 (so called IPv4
1747 mapped IPv6 address). <application>Privoxy</application> can handle it
1748 and maps such ACL addresses automatically.
1751 Denying access to particular sites by ACL may have undesired side effects
1752 if the site in question is hosted on a machine which also hosts other sites
1758 <term>Examples:</term>
1761 Explicitly define the default behavior if no ACL and
1762 <literal>listen-address</literal> are set: <quote>localhost</quote>
1763 is OK. The absence of a <replaceable class="parameter">dst_addr</replaceable> implies that
1764 <emphasis>all</emphasis> destination addresses are OK:
1767 permit-access localhost
1770 Allow any host on the same class C subnet as www.privoxy.org access to
1771 nothing but www.example.com (or other domains hosted on the same system):
1774 permit-access www.privoxy.org/24 www.example.com/32
1777 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1778 with the exception that 192.168.45.73 may not access the IP address behind
1779 www.dirty-stuff.example.com:
1782 permit-access 192.168.45.64/26
1783 deny-access 192.168.45.73 www.dirty-stuff.example.com
1786 Allow access from the IPv4 network 192.0.2.0/24 even if listening on
1787 an IPv6 wild card address (not supported on all platforms):
1790 permit-access 192.0.2.0/24
1793 This is equivalent to the following line even if listening on an
1794 IPv4 address (not supported on all platforms):
1797 permit-access [::ffff:192.0.2.0]/120
1805 <!-- ~~~~~ New section ~~~~~ -->
1806 <sect3 renderas="sect4" id="buffer-limit"><title>buffer-limit</title>
1810 <term>Specifies:</term>
1813 Maximum size of the buffer for content filtering.
1818 <term>Type of value:</term>
1820 <para>Size in Kbytes</para>
1824 <term>Default value:</term>
1830 <term>Effect if unset:</term>
1833 Use a 4MB (4096 KB) limit.
1841 For content filtering, i.e. the <literal>+filter</literal> and
1842 <literal>+deanimate-gif</literal> actions, it is necessary that
1843 <application>Privoxy</application> buffers the entire document body.
1844 This can be potentially dangerous, since a server could just keep sending
1845 data indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1849 When a document buffer size reaches the <literal>buffer-limit</literal>, it is
1850 flushed to the client unfiltered and no further attempt to
1851 filter the rest of the document is made. Remember that there may be multiple threads
1852 running, which might require up to <literal>buffer-limit</literal> Kbytes
1853 <emphasis>each</emphasis>, unless you have enabled <quote>single-threaded</quote>
1860 <![%config-file;[<literallayout>@@buffer-limit 4096</literallayout>]]>
1863 <!-- ~~~~~ New section ~~~~~ -->
1864 <sect3 renderas="sect4" id="enable-proxy-authentication-forwarding"><title>enable-proxy-authentication-forwarding</title>
1867 <term>Specifies:</term>
1870 Whether or not proxy authentication through &my-app; should work.
1875 <term>Type of value:</term>
1881 <term>Default value:</term>
1887 <term>Effect if unset:</term>
1890 Proxy authentication headers are removed.
1898 Privoxy itself does not support proxy authentication, but can
1899 allow clients to authenticate against Privoxy's parent proxy.
1902 By default Privoxy (3.0.21 and later) don't do that and remove
1903 Proxy-Authorization headers in requests and Proxy-Authenticate
1904 headers in responses to make it harder for malicious sites to
1905 trick inexperienced users into providing login information.
1908 If this option is enabled the headers are forwarded.
1911 Enabling this option is <emphasis>not recommended</emphasis> if there is
1912 no parent proxy that requires authentication or if the local network between
1913 Privoxy and the parent proxy isn't trustworthy. If proxy authentication is
1914 only required for some requests, it is recommended to use a client header filter
1915 to remove the authentication headers for requests where they aren't needed.
1921 <![%config-file;[<literallayout>@@enable-proxy-authentication-forwarding 0</literallayout>]]>
1924 <!-- ~~~~~ New section ~~~~~ -->
1925 <sect3 renderas="sect4" id="trusted-cgi-referer"><title>trusted-cgi-referer</title>
1928 <term>Specifies:</term>
1931 A trusted website or webpage whose links can be followed to reach sensitive CGI pages
1936 <term>Type of value:</term>
1938 <para>URL or URL prefix</para>
1942 <term>Default value:</term>
1948 <term>Effect if unset:</term>
1951 No external pages are considered trusted referers.
1959 Before &my-app; accepts configuration changes through CGI pages like
1960 <link linkend="client-specific-tag">client-tags</link> or the
1961 <link linkend="enable-remote-toggle">remote toggle</link>, it checks
1962 the Referer header to see if the request comes from a trusted source.
1965 By default only the webinterface domains
1966 <ulink url="http://config.privoxy.org/">config.privoxy.org</ulink>
1968 <ulink url="http://p.p/">p.p</ulink>
1969 are considered trustworthy.
1970 Requests originating from other domains are rejected to prevent
1971 third-parties from modifiying Privoxy's state by e.g. embedding
1972 images that result in CGI requests.
1975 In some environments it may be desirable to embed links to CGI pages
1976 on external pages, for example on an Intranet homepage the Privoxy admin
1980 The <quote>trusted-cgi-referer</quote> option can be used to add that page,
1981 or the whole domain, as trusted source so the resulting requests aren't
1983 Requests are accepted if the specified trusted-cgi-refer is the prefix
1987 If the trusted source is supposed to access the CGI pages via
1988 JavaScript the <link linkend="cors-allowed-origin">cors-allowed-origin</link>
1993 Declaring pages the admin doesn't control trustworthy may allow
1994 malicious third parties to modify Privoxy's internal state against
1995 the user's wishes and without the user's knowledge.
2002 <![%config-file;[<literallayout>@@#trusted-cgi-referer http://www.example.org/local-privoxy-control-page</literallayout>]]>
2006 <!-- ~~~~~ New section ~~~~~ -->
2007 <sect3 renderas="sect4" id="cors-allowed-origin"><title>cors-allowed-origin</title>
2010 <term>Specifies:</term>
2013 A trusted website which can access &my-app;'s CGI pages through JavaScript.
2018 <term>Type of value:</term>
2024 <term>Default value:</term>
2030 <term>Effect if unset:</term>
2033 No external sites get access via cross-origin resource sharing.
2041 Modern browsers by default prevent cross-origin requests made
2042 via JavaScript to &my-app;'s CGI interface even if &my-app;
2043 would trust the referer because it's white listed via the
2044 <link linkend="trusted-cgi-referer">trusted-cgi-referer</link>
2048 <ulink url="https://en.wikipedia.org/wiki/Cross-origin_resource_sharing"
2049 >Cross-origin resource sharing (CORS)</ulink> is a mechanism to allow
2050 cross-origin requests.
2053 The <quote>cors-allowed-origin</quote> option can be used to specify
2054 a domain that is allowed to make requests to Privoxy CGI interface
2055 via JavaScript. It is used in combination with the
2056 <link linkend="trusted-cgi-referer">trusted-cgi-referer</link>
2061 Declaring domains the admin doesn't control trustworthy may allow
2062 malicious third parties to modify Privoxy's internal state against
2063 the user's wishes and without the user's knowledge.
2070 <![%config-file;[<literallayout>@@#cors-allowed-origin http://www.example.org/</literallayout>]]>
2075 <!-- ~ End section ~ -->
2078 <!-- ~~~~~ New section ~~~~~ -->
2080 <sect2 id="forwarding">
2081 <title>Forwarding</title>
2084 This feature allows routing of HTTP requests through a chain of
2088 Forwarding can be used to chain Privoxy with a caching proxy to speed
2089 up browsing. Using a parent proxy may also be necessary if the machine
2090 that <application>Privoxy</application> runs on has no direct Internet access.
2093 Note that parent proxies can severely decrease your privacy level.
2094 For example a parent proxy could add your IP address to the request
2095 headers and if it's a caching proxy it may add the <quote>Etag</quote>
2096 header to revalidation requests again, even though you configured Privoxy
2097 to remove it. It may also ignore Privoxy's header time randomization and use the
2098 original values which could be used by the server as cookie replacement
2099 to track your steps between visits.
2103 Also specified here are SOCKS proxies. <application>Privoxy</application>
2104 supports the SOCKS 4 and SOCKS 4A protocols.
2107 <sect3 renderas="sect4" id="forward"><title>forward</title>
2110 <term>Specifies:</term>
2113 To which parent HTTP proxy specific requests should be routed.
2118 <term>Type of value:</term>
2121 <replaceable class="parameter">target_pattern</replaceable>
2122 <replaceable class="parameter">http_parent</replaceable>[:<replaceable class="parameter">port</replaceable>]
2125 where <replaceable class="parameter">target_pattern</replaceable> is a <link linkend="af-patterns">URL pattern</link>
2126 that specifies to which requests (i.e. URLs) this forward rule shall apply. Use <literal>/</literal> to
2127 denote <quote>all URLs</quote>.
2128 <replaceable class="parameter">http_parent</replaceable>[:<replaceable class="parameter">port</replaceable>]
2129 is the DNS name or IP address of the parent HTTP proxy through which the requests should be forwarded,
2130 optionally followed by its listening port (default: 8000).
2131 Use a single dot (<literal>.</literal>) to denote <quote>no forwarding</quote>.
2136 <term>Default value:</term>
2138 <para><emphasis>Unset</emphasis></para>
2142 <term>Effect if unset:</term>
2145 Don't use parent HTTP proxies.
2153 If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
2154 forwarded to another HTTP proxy but are made directly to the web servers.
2157 <replaceable class="parameter">http_parent</replaceable> can be a
2158 numerical IPv6 address (if
2159 <ulink url="http://tools.ietf.org/html/rfc3493">RFC 3493</ulink> is
2160 implemented). To prevent clashes with the port delimiter, the whole IP
2161 address has to be put into brackets. On the other hand a <replaceable
2162 class="parameter">target_pattern</replaceable> containing an IPv6 address
2163 has to be put into angle brackets (normal brackets are reserved for
2164 regular expressions already).
2167 Multiple lines are OK, they are checked in sequence, and the last match wins.
2172 <term>Examples:</term>
2175 Everything goes to an example parent proxy, except SSL on port 443 (which it doesn't handle):
2178 forward / parent-proxy.example.org:8080
2182 Everything goes to our example ISP's caching proxy, except for requests
2183 to that ISP's sites:
2186 forward / caching-proxy.isp.example.net:8000
2187 forward .isp.example.net .
2190 Parent proxy specified by an IPv6 address:
2193 forward / [2001:DB8::1]:8000
2196 Suppose your parent proxy doesn't support IPv6:
2199 forward / parent-proxy.example.org:8000
2200 forward ipv6-server.example.org .
2201 forward <[2-3][0-9a-f][0-9a-f][0-9a-f]:*> .
2209 <!-- ~~~~~ New section ~~~~~ -->
2210 <sect3 renderas="sect4" id="socks"><title>
2211 forward-socks4, forward-socks4a, forward-socks5 and forward-socks5t</title>
2212 <anchor id="forward-socks4">
2213 <anchor id="forward-socks4a">
2217 <term>Specifies:</term>
2220 Through which SOCKS proxy (and optionally to which parent HTTP proxy) specific requests should be routed.
2225 <term>Type of value:</term>
2228 <replaceable class="parameter">target_pattern</replaceable>
2229 <replaceable class="parameter">socks_proxy</replaceable>[:<replaceable class="parameter">port</replaceable>]
2230 <replaceable class="parameter">http_parent</replaceable>[:<replaceable class="parameter">port</replaceable>]
2233 where <replaceable class="parameter">target_pattern</replaceable> is a
2234 <link linkend="af-patterns">URL pattern</link> that specifies to which
2235 requests (i.e. URLs) this forward rule shall apply. Use <literal>/</literal> to
2236 denote <quote>all URLs</quote>. <replaceable class="parameter">http_parent</replaceable>
2237 and <replaceable class="parameter">socks_proxy</replaceable>
2238 are IP addresses in dotted decimal notation or valid DNS names
2239 (<replaceable class="parameter">http_parent</replaceable>
2240 may be <quote>.</quote> to denote <quote>no HTTP forwarding</quote>), and the optional
2241 <replaceable class="parameter">port</replaceable> parameters are TCP ports,
2242 i.e. integer values from 1 to 65535
2247 <term>Default value:</term>
2249 <para><emphasis>Unset</emphasis></para>
2253 <term>Effect if unset:</term>
2256 Don't use SOCKS proxies.
2264 Multiple lines are OK, they are checked in sequence, and the last match wins.
2267 The difference between <literal>forward-socks4</literal> and <literal>forward-socks4a</literal>
2268 is that in the SOCKS 4A protocol, the DNS resolution of the target hostname happens on the SOCKS
2269 server, while in SOCKS 4 it happens locally.
2272 With <literal>forward-socks5</literal> the DNS resolution will happen on the remote server as well.
2275 <literal>forward-socks5t</literal> works like vanilla <literal>forward-socks5</literal> but
2276 lets &my-app; additionally use Tor-specific SOCKS extensions. Currently the only supported
2277 SOCKS extension is optimistic data which can reduce the latency for the first request made
2278 on a newly created connection.
2281 <replaceable class="parameter">socks_proxy</replaceable> and
2282 <replaceable class="parameter">http_parent</replaceable> can be a
2283 numerical IPv6 address (if
2284 <ulink url="http://tools.ietf.org/html/rfc3493">RFC 3493</ulink> is
2285 implemented). To prevent clashes with the port delimiter, the whole IP
2286 address has to be put into brackets. On the other hand a <replaceable
2287 class="parameter">target_pattern</replaceable> containing an IPv6 address
2288 has to be put into angle brackets (normal brackets are reserved for
2289 regular expressions already).
2292 If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
2293 forwarded to another HTTP proxy but are made (HTTP-wise) directly to the web servers, albeit through
2299 <term>Examples:</term>
2302 From the company example.com, direct connections are made to all
2303 <quote>internal</quote> domains, but everything outbound goes through
2304 their ISP's proxy by way of example.com's corporate SOCKS 4A gateway to
2308 forward-socks4a / socks-gw.example.com:1080 www-cache.isp.example.net:8080
2309 forward .example.com .
2312 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this:
2315 forward-socks4 / socks-gw.example.com:1080 .
2319 To chain Privoxy and Tor, both running on the same system, you would use
2323 forward-socks5t / 127.0.0.1:9050 .
2326 Note that if you got Tor through one of the bundles, you may
2327 have to change the port from 9050 to 9150 (or even another one).
2328 For details, please check the documentation on the
2329 <ulink url="https://torproject.org/">Tor website</ulink>.
2332 The public <application>Tor</application> network can't be used to
2333 reach your local network, if you need to access local servers you
2334 therefore might want to make some exceptions:
2337 forward 192.168.*.*/ .
2339 forward 127.*.*.*/ .
2342 Unencrypted connections to systems in these address ranges will
2343 be as (un)secure as the local network is, but the alternative is that you
2344 can't reach the local network through <application>Privoxy</application>
2345 at all. Of course this may actually be desired and there is no reason
2346 to make these exceptions if you aren't sure you need them.
2349 If you also want to be able to reach servers in your local network by
2350 using their names, you will need additional exceptions that look like
2354 forward localhost/ .
2362 <![%user-man;[ <!-- not included in config due to length -->
2363 <!-- ~~~~~ New section ~~~~~ -->
2364 <sect3 renderas="sect4" id="advanced-forwarding-examples"><title>Advanced Forwarding Examples</title>
2367 If you have links to multiple ISPs that provide various special content
2368 only to their subscribers, you can configure multiple <application>Privoxies</application>
2369 which have connections to the respective ISPs to act as forwarders to each other, so that
2370 <emphasis>your</emphasis> users can see the internal content of all ISPs.
2374 Assume that host-a has a PPP connection to isp-a.example.net. And host-b has a PPP connection to
2375 isp-b.example.org. Both run <application>Privoxy</application>. Their forwarding
2376 configuration can look like this:
2385 forward .isp-b.example.net host-b:8118
2394 forward .isp-a.example.org host-a:8118
2398 Now, your users can set their browser's proxy to use either
2399 host-a or host-b and be able to browse the internal content
2400 of both isp-a and isp-b.
2404 If you intend to chain <application>Privoxy</application> and
2405 <application>squid</application> locally, then chaining as
2406 <literal>browser -> squid -> privoxy</literal> is the recommended way.
2410 Assuming that <application>Privoxy</application> and <application>squid</application>
2411 run on the same box, your <application>squid</application> configuration could then look like this:
2415 # Define Privoxy as parent proxy (without ICP)
2416 cache_peer 127.0.0.1 parent 8118 7 no-query
2418 # Define ACL for protocol FTP
2421 # Do not forward FTP requests to Privoxy
2422 always_direct allow ftp
2424 # Forward all the rest to Privoxy
2425 never_direct allow all</screen>
2428 You would then need to change your browser's proxy settings to <application>squid</application>'s address and port.
2429 Squid normally uses port 3128. If unsure consult <literal>http_port</literal> in <filename>squid.conf</filename>.
2433 You could just as well decide to only forward requests you suspect
2434 of leading to Windows executables through a virus-scanning parent proxy,
2435 say, on <literal>antivir.example.com</literal>, port 8010:
2440 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010</screen>
2445 <sect3 renderas="sect4" id="forwarded-connect-retries"><title>forwarded-connect-retries</title>
2448 <term>Specifies:</term>
2451 How often Privoxy retries if a forwarded connection request fails.
2456 <term>Type of value:</term>
2459 <replaceable class="parameter">Number of retries.</replaceable>
2464 <term>Default value:</term>
2466 <para><emphasis>0</emphasis></para>
2470 <term>Effect if unset:</term>
2473 Connections forwarded through other proxies are treated like direct connections and no retry attempts are made.
2481 <replaceable class="parameter">forwarded-connect-retries</replaceable> is mainly interesting
2482 for socks4a connections, where <application>Privoxy</application> can't detect why the connections failed.
2483 The connection might have failed because of a DNS timeout in which case a retry makes sense,
2484 but it might also have failed because the server doesn't exist or isn't reachable. In this
2485 case the retry will just delay the appearance of Privoxy's error message.
2488 Note that in the context of this option, <quote>forwarded connections</quote> includes all connections
2489 that Privoxy forwards through other proxies. This option is not limited to the HTTP CONNECT method.
2492 Only use this option, if you are getting lots of forwarding-related error messages
2493 that go away when you try again manually. Start with a small value and check Privoxy's
2494 logfile from time to time, to see how many retries are usually needed.
2499 <term>Examples:</term>
2502 forwarded-connect-retries 1
2507 <![%config-file;[<literallayout>@@forwarded-connect-retries 0</literallayout>]]>
2513 <title>Miscellaneous</title>
2515 <sect3 renderas="sect4" id="accept-intercepted-requests"><title>accept-intercepted-requests</title>
2518 <term>Specifies:</term>
2521 Whether intercepted requests should be treated as valid.
2526 <term>Type of value:</term>
2529 <replaceable>0 or 1</replaceable>
2534 <term>Default value:</term>
2536 <para><emphasis>0</emphasis></para>
2540 <term>Effect if unset:</term>
2543 Only proxy requests are accepted, intercepted requests are treated as invalid.
2551 If you don't trust your clients and want to force them
2552 to use <application>Privoxy</application>, enable this
2553 option and configure your packet filter to redirect outgoing
2554 HTTP connections into <application>Privoxy</application>.
2557 Note that intercepting encrypted connections (HTTPS) isn't supported.
2560 Make sure that <application>Privoxy's</application> own requests
2561 aren't redirected as well. Additionally take care that
2562 <application>Privoxy</application> can't intentionally connect
2563 to itself, otherwise you could run into redirection loops if
2564 <application>Privoxy's</application> listening port is reachable
2565 by the outside or an attacker has access to the pages you visit.
2568 If you are running Privoxy as intercepting proxy without being
2569 able to intercept all client requests you may want to adjust
2570 the CGI templates to make sure they don't reference content from
2576 <term>Examples:</term>
2579 accept-intercepted-requests 1
2584 <![%config-file;[<literallayout>@@accept-intercepted-requests 0</literallayout>]]>
2587 <sect3 renderas="sect4" id="allow-cgi-request-crunching"><title>allow-cgi-request-crunching</title>
2590 <term>Specifies:</term>
2593 Whether requests to <application>Privoxy's</application> CGI pages can be blocked or redirected.
2598 <term>Type of value:</term>
2601 <replaceable>0 or 1</replaceable>
2606 <term>Default value:</term>
2608 <para><emphasis>0</emphasis></para>
2612 <term>Effect if unset:</term>
2615 <application>Privoxy</application> ignores block and redirect actions for its CGI pages.
2623 By default <application>Privoxy</application> ignores block or redirect actions
2624 for its CGI pages. Intercepting these requests can be useful in multi-user
2625 setups to implement fine-grained access control, but it can also render the complete
2626 web interface useless and make debugging problems painful if done without care.
2629 Don't enable this option unless you're sure that you really need it.
2634 <term>Examples:</term>
2637 allow-cgi-request-crunching 1
2642 <![%config-file;[<literallayout>@@allow-cgi-request-crunching 0</literallayout>]]>
2645 <sect3 renderas="sect4" id="split-large-forms"><title>split-large-forms</title>
2648 <term>Specifies:</term>
2651 Whether the CGI interface should stay compatible with broken HTTP clients.
2656 <term>Type of value:</term>
2659 <replaceable>0 or 1</replaceable>
2664 <term>Default value:</term>
2666 <para><emphasis>0</emphasis></para>
2670 <term>Effect if unset:</term>
2673 The CGI form generate long GET URLs.
2681 <application>Privoxy's</application> CGI forms can lead to
2682 rather long URLs. This isn't a problem as far as the HTTP
2683 standard is concerned, but it can confuse clients with arbitrary
2684 URL length limitations.
2687 Enabling split-large-forms causes <application>Privoxy</application>
2688 to divide big forms into smaller ones to keep the URL length down.
2689 It makes editing a lot less convenient and you can no longer
2690 submit all changes at once, but at least it works around this
2694 If you don't notice any editing problems, there is no reason
2695 to enable this option, but if one of the submit buttons appears
2696 to be broken, you should give it a try.
2701 <term>Examples:</term>
2709 <![%config-file;[<literallayout>@@split-large-forms 0</literallayout>]]>
2712 <sect3 renderas="sect4" id="keep-alive-timeout"><title>keep-alive-timeout</title>
2715 <term>Specifies:</term>
2718 Number of seconds after which an open connection will no longer be reused.
2723 <term>Type of value:</term>
2726 <replaceable>Time in seconds.</replaceable>
2731 <term>Default value:</term>
2737 <term>Effect if unset:</term>
2740 Connections are not kept alive.
2748 This option allows clients to keep the connection to &my-app;
2749 alive. If the server supports it, &my-app; will keep
2750 the connection to the server alive as well. Under certain
2751 circumstances this may result in speed-ups.
2754 By default, &my-app; will close the connection to the server if
2755 the client connection gets closed, or if the specified timeout
2756 has been reached without a new request coming in. This behaviour
2757 can be changed with the <ulink
2758 url="#CONNECTION-SHARING">connection-sharing</ulink> option.
2761 This option has no effect if <application>Privoxy</application>
2762 has been compiled without keep-alive support.
2765 Note that a timeout of five seconds as used in the default
2766 configuration file significantly decreases the number of
2767 connections that will be reused. The value is used because
2768 some browsers limit the number of connections they open to
2769 a single host and apply the same limit to proxies. This can
2770 result in a single website <quote>grabbing</quote> all the
2771 connections the browser allows, which means connections to
2772 other websites can't be opened until the connections currently
2776 Several users have reported this as a Privoxy bug, so the
2777 default value has been reduced. Consider increasing it to
2778 300 seconds or even more if you think your browser can handle
2779 it. If your browser appears to be hanging, it probably can't.
2784 <term>Examples:</term>
2787 keep-alive-timeout 300
2792 <![%config-file;[<literallayout>@@keep-alive-timeout 5</literallayout>]]>
2796 <sect3 renderas="sect4" id="tolerate-pipelining"><title>tolerate-pipelining</title>
2799 <term>Specifies:</term>
2802 Whether or not pipelined requests should be served.
2807 <term>Type of value:</term>
2810 <replaceable>0 or 1.</replaceable>
2815 <term>Default value:</term>
2821 <term>Effect if unset:</term>
2824 If Privoxy receives more than one request at once, it terminates the
2825 client connection after serving the first one.
2833 &my-app; currently doesn't pipeline outgoing requests,
2834 thus allowing pipelining on the client connection is not
2835 guaranteed to improve the performance.
2838 By default &my-app; tries to discourage clients from pipelining
2839 by discarding aggressively pipelined requests, which forces the
2840 client to resend them through a new connection.
2843 This option lets &my-app; tolerate pipelining. Whether or not
2844 that improves performance mainly depends on the client configuration.
2847 If you are seeing problems with pages not properly loading,
2848 disabling this option could work around the problem.
2853 <term>Examples:</term>
2856 tolerate-pipelining 1
2861 <![%config-file;[<literallayout>@@tolerate-pipelining 1</literallayout>]]>
2865 <sect3 renderas="sect4" id="default-server-timeout"><title>default-server-timeout</title>
2868 <term>Specifies:</term>
2871 Assumed server-side keep-alive timeout if not specified by the server.
2876 <term>Type of value:</term>
2879 <replaceable>Time in seconds.</replaceable>
2884 <term>Default value:</term>
2890 <term>Effect if unset:</term>
2893 Connections for which the server didn't specify the keep-alive
2894 timeout are not reused.
2902 Enabling this option significantly increases the number of connections
2903 that are reused, provided the <ulink
2904 url="#KEEP-ALIVE-TIMEOUT">keep-alive-timeout</ulink> option
2908 While it also increases the number of connections problems
2909 when &my-app; tries to reuse a connection that already has
2910 been closed on the server side, or is closed while &my-app;
2911 is trying to reuse it, this should only be a problem if it
2912 happens for the first request sent by the client. If it happens
2913 for requests on reused client connections, &my-app; will simply
2914 close the connection and the client is supposed to retry the
2915 request without bothering the user.
2918 Enabling this option is therefore only recommended if the
2920 url="#CONNECTION-SHARING">connection-sharing</ulink> option
2924 It is an error to specify a value larger than the <ulink
2925 url="#KEEP-ALIVE-TIMEOUT">keep-alive-timeout</ulink> value.
2928 This option has no effect if <application>Privoxy</application>
2929 has been compiled without keep-alive support.
2934 <term>Examples:</term>
2937 default-server-timeout 60
2942 <![%config-file;[<literallayout>@@#default-server-timeout 60</literallayout>]]>
2946 <sect3 renderas="sect4" id="connection-sharing"><title>connection-sharing</title>
2949 <term>Specifies:</term>
2952 Whether or not outgoing connections that have been kept alive
2953 should be shared between different incoming connections.
2958 <term>Type of value:</term>
2961 <replaceable>0 or 1</replaceable>
2966 <term>Default value:</term>
2972 <term>Effect if unset:</term>
2975 Connections are not shared.
2983 This option has no effect if <application>Privoxy</application>
2984 has been compiled without keep-alive support, or if it's disabled.
2992 Note that reusing connections doesn't necessary cause speedups.
2993 There are also a few privacy implications you should be aware of.
2996 If this option is effective, outgoing connections are shared between
2997 clients (if there are more than one) and closing the browser that initiated
2998 the outgoing connection does no longer affect the connection between &my-app;
2999 and the server unless the client's request hasn't been completed yet.
3002 If the outgoing connection is idle, it will not be closed until either
3003 <application>Privoxy's</application> or the server's timeout is reached.
3004 While it's open, the server knows that the system running &my-app; is still
3008 If there are more than one client (maybe even belonging to multiple users),
3009 they will be able to reuse each others connections. This is potentially
3010 dangerous in case of authentication schemes like NTLM where only the
3011 connection is authenticated, instead of requiring authentication for
3015 If there is only a single client, and if said client can keep connections
3016 alive on its own, enabling this option has next to no effect. If the client
3017 doesn't support connection keep-alive, enabling this option may make sense
3018 as it allows &my-app; to keep outgoing connections alive even if the client
3019 itself doesn't support it.
3022 You should also be aware that enabling this option increases the likelihood
3023 of getting the "No server or forwarder data" error message, especially if you
3024 are using a slow connection to the Internet.
3027 This option should only be used by experienced users who
3028 understand the risks and can weight them against the benefits.
3033 <term>Examples:</term>
3036 connection-sharing 1
3041 <![%config-file;[<literallayout>@@#connection-sharing 1</literallayout>]]>
3045 <sect3 renderas="sect4" id="socket-timeout"><title>socket-timeout</title>
3048 <term>Specifies:</term>
3051 Number of seconds after which a socket times out if
3052 no data is received.
3057 <term>Type of value:</term>
3060 <replaceable>Time in seconds.</replaceable>
3065 <term>Default value:</term>
3071 <term>Effect if unset:</term>
3074 A default value of 300 seconds is used.
3082 The default is quite high and you probably want to reduce it.
3083 If you aren't using an occasionally slow proxy like Tor, reducing
3084 it to a few seconds should be fine.
3089 <term>Examples:</term>
3097 <![%config-file;[<literallayout>@@socket-timeout 300</literallayout>]]>
3101 <sect3 renderas="sect4" id="max-client-connections"><title>max-client-connections</title>
3104 <term>Specifies:</term>
3107 Maximum number of client connections that will be served.
3112 <term>Type of value:</term>
3115 <replaceable>Positive number.</replaceable>
3120 <term>Default value:</term>
3126 <term>Effect if unset:</term>
3129 Connections are served until a resource limit is reached.
3137 &my-app; creates one thread (or process) for every incoming client
3138 connection that isn't rejected based on the access control settings.
3141 If the system is powerful enough, &my-app; can theoretically deal with
3142 several hundred (or thousand) connections at the same time, but some
3143 operating systems enforce resource limits by shutting down offending
3144 processes and their default limits may be below the ones &my-app; would
3145 require under heavy load.
3148 Configuring &my-app; to enforce a connection limit below the thread
3149 or process limit used by the operating system makes sure this doesn't
3150 happen. Simply increasing the operating system's limit would work too,
3151 but if &my-app; isn't the only application running on the system,
3152 you may actually want to limit the resources used by &my-app;.
3155 If &my-app; is only used by a single trusted user, limiting the
3156 number of client connections is probably unnecessary. If there
3157 are multiple possibly untrusted users you probably still want to
3158 additionally use a packet filter to limit the maximal number of
3159 incoming connections per client. Otherwise a malicious user could
3160 intentionally create a high number of connections to prevent other
3161 users from using &my-app;.
3164 Obviously using this option only makes sense if you choose a limit
3165 below the one enforced by the operating system.
3168 One most POSIX-compliant systems &my-app; can't properly deal with
3169 more than FD_SETSIZE file descriptors at the same time and has to reject
3170 connections if the limit is reached. This will likely change in a
3171 future version, but currently this limit can't be increased without
3172 recompiling &my-app; with a different FD_SETSIZE limit.
3177 <term>Examples:</term>
3180 max-client-connections 256
3185 <![%config-file;[<literallayout>@@#max-client-connections 256</literallayout>]]>
3189 <sect3 renderas="sect4" id="listen-backlog"><title>listen-backlog</title>
3192 <term>Specifies:</term>
3195 Connection queue length requested from the operating system.
3200 <term>Type of value:</term>
3203 <replaceable>Number.</replaceable>
3208 <term>Default value:</term>
3214 <term>Effect if unset:</term>
3217 A connection queue length of 128 is requested from the operating system.
3225 Under high load incoming connection may queue up before Privoxy
3226 gets around to serve them. The queue length is limitted by the
3227 operating system. Once the queue is full, additional connections
3228 are dropped before Privoxy can accept and serve them.
3231 Increasing the queue length allows Privoxy to accept more
3232 incomming connections that arrive roughly at the same time.
3235 Note that Privoxy can only request a certain queue length,
3236 whether or not the requested length is actually used depends
3237 on the operating system which may use a different length instead.
3240 On many operating systems a limit of -1 can be specified to
3241 instruct the operating system to use the maximum queue length
3242 allowed. Check the listen man page to see if your platform allows this.
3245 On some platforms you can use "netstat -Lan -p tcp" to see the effective
3249 Effectively using a value above 128 usually requires changing
3250 the system configuration as well. On FreeBSD-based system the
3251 limit is controlled by the kern.ipc.soacceptqueue sysctl.
3256 <term>Examples:</term>
3264 <![%config-file;[<literallayout>@@#listen-backlog -1</literallayout>]]>
3268 <sect3 renderas="sect4" id="enable-accept-filter"><title>enable-accept-filter</title>
3271 <term>Specifies:</term>
3274 Whether or not Privoxy should use an accept filter
3279 <term>Type of value:</term>
3282 <replaceable>0 or 1</replaceable>
3287 <term>Default value:</term>
3293 <term>Effect if unset:</term>
3296 No accept filter is enabled.
3304 Accept filters reduce the number of context switches by not
3305 passing sockets for new connections to Privoxy until a complete
3306 HTTP request is available.
3309 As a result, Privoxy can process the whole request right away
3310 without having to wait for additional data first.
3313 For this option to work, Privoxy has to be compiled with
3314 FEATURE_ACCEPT_FILTER and the operating system has to support
3315 it (which may require loading a kernel module).
3318 Currently accept filters are only supported on FreeBSD-based
3320 <ulink url="https://www.freebsd.org/cgi/man.cgi?query=accf_http">accf_http(9)
3322 to learn how to enable the support in the operating system.
3327 <term>Examples:</term>
3330 enable-accept-filter 1
3335 <![%config-file;[<literallayout>@@#enable-accept-filter 1</literallayout>]]>
3339 <sect3 renderas="sect4" id="handle-as-empty-doc-returns-ok"><title>handle-as-empty-doc-returns-ok</title>
3342 <term>Specifies:</term>
3345 The status code Privoxy returns for pages blocked with
3346 <!-- URL will only end up in the user manual so the relative link should work. -->
3347 <literal><ulink url="actions-file.html#HANDLE-AS-EMPTY-DOCUMENT">+handle-as-empty-document</ulink></literal>.
3352 <term>Type of value:</term>
3355 <replaceable>0 or 1</replaceable>
3360 <term>Default value:</term>
3366 <term>Effect if unset:</term>
3369 Privoxy returns a status 403(forbidden) for all blocked pages.
3374 <term>Effect if set:</term>
3377 Privoxy returns a status 200(OK) for pages blocked with +handle-as-empty-document
3378 and a status 403(Forbidden) for all other blocked pages.
3386 This directive was added as a work-around for Firefox bug 492459:
3387 <quote>Websites are no longer rendered if SSL requests for JavaScripts are blocked by a proxy.</quote>
3388 (<ulink url="https://bugzilla.mozilla.org/show_bug.cgi?id=492459">
3389 https://bugzilla.mozilla.org/show_bug.cgi?id=492459</ulink>),
3390 the bug has been fixed for quite some time, but this directive is also useful
3391 to make it harder for websites to detect whether or not resources are being
3397 <![%config-file;[<literallayout>@@#handle-as-empty-doc-returns-ok 1</literallayout>]]>
3401 <sect3 renderas="sect4" id="enable-compression"><title>enable-compression</title>
3404 <term>Specifies:</term>
3407 Whether or not buffered content is compressed before delivery.
3412 <term>Type of value:</term>
3415 <replaceable>0 or 1</replaceable>
3420 <term>Default value:</term>
3426 <term>Effect if unset:</term>
3429 Privoxy does not compress buffered content.
3434 <term>Effect if set:</term>
3437 Privoxy compresses buffered content before delivering it to the client,
3438 provided the client supports it.
3446 This directive is only supported if Privoxy has been compiled with
3447 FEATURE_COMPRESSION, which should not to be confused with FEATURE_ZLIB.
3450 Compressing buffered content is mainly useful if Privoxy and the
3451 client are running on different systems. If they are running on the
3452 same system, enabling compression is likely to slow things down.
3453 If you didn't measure otherwise, you should assume that it does
3454 and keep this option disabled.
3457 Privoxy will not compress buffered content below a certain length.
3462 <![%config-file;[<literallayout>@@#enable-compression 1</literallayout>]]>
3466 <sect3 renderas="sect4" id="compression-level"><title>compression-level</title>
3469 <term>Specifies:</term>
3472 The compression level that is passed to the zlib library when compressing buffered content.
3477 <term>Type of value:</term>
3480 <replaceable>Positive number ranging from 0 to 9.</replaceable>
3485 <term>Default value:</term>
3494 Compressing the data more takes usually longer than compressing
3495 it less or not compressing it at all. Which level is best depends
3496 on the connection between Privoxy and the client. If you can't
3497 be bothered to benchmark it for yourself, you should stick with
3498 the default and keep compression disabled.
3501 If compression is disabled, the compression level is irrelevant.
3506 <term>Examples:</term>
3509 # Best speed (compared to the other levels)
3515 # No compression. Only useful for testing as the added header
3516 # slightly increases the amount of data that has to be sent.
3517 # If your benchmark shows that using this compression level
3518 # is superior to using no compression at all, the benchmark
3519 # is likely to be flawed.
3525 <![%config-file;[<literallayout>@@#compression-level 1</literallayout>]]>
3529 <sect3 renderas="sect4" id="client-header-order"><title>client-header-order</title>
3532 <term>Specifies:</term>
3535 The order in which client headers are sorted before forwarding them.
3540 <term>Type of value:</term>
3543 <replaceable>Client header names delimited by spaces or tabs</replaceable>
3548 <term>Default value:</term>
3557 By default &my-app; leaves the client headers in the order they
3558 were sent by the client. Headers are modified in-place, new headers
3559 are added at the end of the already existing headers.
3562 The header order can be used to fingerprint client requests
3563 independently of other headers like the User-Agent.
3566 This directive allows to sort the headers differently to better
3567 mimic a different User-Agent. Client headers will be emitted
3568 in the order given, headers whose name isn't explicitly specified
3569 are added at the end.
3572 Note that sorting headers in an uncommon way will make fingerprinting
3573 actually easier. Encrypted headers are not affected by this directive.
3578 <![%config-file;[<literallayout>@@#client-header-order Host \
3595 <sect3 renderas="sect4" id="client-specific-tag"><title>client-specific-tag</title>
3598 <term>Specifies:</term>
3601 The name of a tag that will always be set for clients that
3602 requested it through the webinterface.
3607 <term>Type of value:</term>
3610 <replaceable>Tag name followed by a description that will be shown in the webinterface</replaceable>
3615 <term>Default value:</term>
3625 This is an experimental feature. The syntax is likely to change
3630 Client-specific tags allow Privoxy admins to create different
3631 profiles and let the users chose which one they want without
3632 impacting other users.
3635 One use case is allowing users to circumvent certain blocks
3636 without having to allow them to circumvent all blocks.
3637 This is not possible with the
3638 <link linkend="enable-remote-toggle">enable-remote-toggle feature</link>
3639 because it would bluntly disable all blocks for all users and also affect
3640 other actions like filters.
3641 It also is set globally which renders it useless in most multi-user setups.
3644 After a client-specific tag has been defined with the client-specific-tag
3645 directive, action sections can be activated based on the tag by using a
3646 <ulink url="actions-file.html#CLIENT-TAG-PATTERN">CLIENT-TAG</ulink> pattern.
3647 The CLIENT-TAG pattern is evaluated at the same priority
3648 as URL patterns, as a result the last matching pattern wins.
3649 Tags that are created based on client or server headers are evaluated
3650 later on and can overrule CLIENT-TAG and URL patterns!
3653 The tag is set for all requests that come from clients that requested
3655 Note that "clients" are differentiated by IP address,
3656 if the IP address changes the tag has to be requested again.
3659 Clients can request tags to be set by using the CGI interface <ulink
3660 url="http://config.privoxy.org/client-tags">http://config.privoxy.org/client-tags</ulink>.
3661 The specific tag description is only used on the web page and should
3662 be phrased in away that the user understand the effect of the tag.
3667 <term>Examples:</term>
3670 # Define a couple of tags, the described effect requires action sections
3671 # that are enabled based on CLIENT-TAG patterns.
3672 client-specific-tag circumvent-blocks Overrule blocks but do not affect other actions
3673 disable-content-filters Disable content-filters but do not affect other actions
3680 <!-- ~ End section ~ -->
3682 <sect3 renderas="sect4" id="client-tag-lifetime"><title>client-tag-lifetime</title>
3685 <term>Specifies:</term>
3688 How long a temporarily enabled tag remains enabled.
3693 <term>Type of value:</term>
3696 <replaceable>Time in seconds.</replaceable>
3701 <term>Default value:</term>
3711 This is an experimental feature. The syntax is likely to change
3716 In case of some tags users may not want to enable them permanently,
3717 but only for a short amount of time, for example to circumvent a block
3718 that is the result of an overly-broad URL pattern.
3721 The CGI interface <ulink
3722 url="http://config.privoxy.org/client-tags">http://config.privoxy.org/client-tags</ulink>
3723 therefore provides a "enable this tag temporarily" option.
3724 If it is used, the tag will be set until the client-tag-lifetime
3730 <term>Examples:</term>
3733 # Increase the time to life for temporarily enabled tags to 3 minutes
3734 client-tag-lifetime 180
3741 <!-- ~ End section ~ -->
3743 <sect3 renderas="sect4" id="trust-x-forwarded-for"><title>trust-x-forwarded-for</title>
3746 <term>Specifies:</term>
3749 Whether or not Privoxy should use IP addresses specified with the X-Forwarded-For header
3754 <term>Type of value:</term>
3757 <replaceable>0 or one</replaceable>
3762 <term>Default value:</term>
3772 This is an experimental feature. The syntax is likely to change
3777 If clients reach Privoxy through another proxy, for example a load
3778 balancer, Privoxy can't tell the client's IP address from the connection.
3779 If multiple clients use the same proxy, they will share the same
3780 client tag settings which is usually not desired.
3783 This option lets Privoxy use the X-Forwarded-For header value as
3784 client IP address. If the proxy sets the header, multiple clients
3785 using the same proxy do not share the same client tag settings.
3788 This option should only be enabled if Privoxy can only be reached
3789 through a proxy and if the proxy can be trusted to set the header
3790 correctly. It is recommended that ACL are used to make sure only
3791 trusted systems can reach Privoxy.
3794 If access to Privoxy isn't limited to trusted systems, this option
3795 would allow malicious clients to change the client tags for other
3796 clients or increase Privoxy's memory requirements by registering
3797 lots of client tag settings for clients that don't exist.
3802 <term>Examples:</term>
3805 # Allow systems that can reach Privoxy to provide the client
3806 # IP address with a X-Forwarded-For header.
3807 trust-x-forwarded-for 1
3814 <!-- ~ End section ~ -->
3816 <!-- ~~~~~ New section ~~~~~ -->
3818 <sect3 renderas="sect4" id="receive-buffer-size"><title>receive-buffer-size</title>
3821 <term>Specifies:</term>
3824 The size of the buffer Privoxy uses to receive data from the server.
3829 <term>Type of value:</term>
3832 <replaceable>Size in bytes</replaceable>
3837 <term>Default value:</term>
3846 Increasing the receive-buffer-size increases Privoxy's memory usage but
3847 can lower the number of context switches and thereby reduce the
3848 cpu usage and potentially increase the throughput.
3851 This is mostly relevant for fast network connections and
3852 large downloads that don't require filtering.
3855 Reducing the buffer size reduces the amount of memory Privoxy
3856 needs to handle the request but increases the number of systemcalls
3857 and may reduce the throughput.
3860 A dtrace command like:
3861 <quote>sudo dtrace -n 'syscall::read:return /execname == "privoxy"/ { @[execname] = llquantize(arg0, 10, 0, 5, 20); @m = max(arg0)}'</quote>
3862 can be used to properly tune the receive-buffer-size.
3863 On systems without dtrace, strace or truss may be used as
3864 less convenient alternatives.
3867 If the buffer is too large it will increase Privoxy's memory
3868 footprint without any benefit. As the memory is (currently)
3869 cleared before using it, a buffer that is too large can
3870 actually reduce the throughput.
3875 <term>Examples:</term>
3878 # Increase the receive buffer size
3879 receive-buffer-size 32768
3886 <!-- ~ End section ~ -->
3890 <!-- ~~~~~ New section ~~~~~ -->
3892 <sect2 id="windows-gui">
3893 <title>Windows GUI Options</title>
3895 <application>Privoxy</application> has a number of options specific to the
3896 Windows GUI interface:
3899 <anchor id="activity-animation">
3900 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3902 If <quote>activity-animation</quote> is set to 1, the
3903 <application>Privoxy</application> icon will animate when
3904 <quote>Privoxy</quote> is active. To turn off, set to 0.
3907 <![%config-file;[<literallayout>@@#activity-animation 1</literallayout>]]>
3910 <emphasis>activity-animation 1</emphasis>
3914 <anchor id="log-messages">
3915 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3917 If <quote>log-messages</quote> is set to 1,
3918 <application>Privoxy</application> copies log messages to the console
3920 The log detail depends on the <link linkend="debug">debug</link> directive.
3923 <![%config-file;[<literallayout>@@#log-messages 1</literallayout>]]>
3926 <emphasis>log-messages 1</emphasis>
3930 <anchor id="log-buffer-size">
3931 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3933 If <quote>log-buffer-size</quote> is set to 1, the size of the log buffer,
3934 i.e. the amount of memory used for the log messages displayed in the
3935 console window, will be limited to <quote>log-max-lines</quote> (see below).
3939 Warning: Setting this to 0 will result in the buffer to grow infinitely and
3940 eat up all your memory!
3943 <![%config-file;[<literallayout>@@#log-buffer-size 1</literallayout>]]>
3946 <emphasis>log-buffer-size 1</emphasis>
3950 <anchor id="log-max-lines">
3951 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3953 <application>log-max-lines</application> is the maximum number of lines held
3954 in the log buffer. See above.
3957 <![%config-file;[<literallayout>@@#log-max-lines 200</literallayout>]]>
3960 <emphasis>log-max-lines 200</emphasis>
3964 <anchor id="log-highlight-messages">
3965 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3967 If <quote>log-highlight-messages</quote> is set to 1,
3968 <application>Privoxy</application> will highlight portions of the log
3969 messages with a bold-faced font:
3972 <![%config-file;[<literallayout>@@#log-highlight-messages 1</literallayout>]]>
3975 <emphasis>log-highlight-messages 1</emphasis>
3979 <anchor id="log-font-name">
3980 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3982 The font used in the console window:
3985 <![%config-file;[<literallayout>@@#log-font-name Comic Sans MS</literallayout>]]>
3988 <emphasis>log-font-name Comic Sans MS</emphasis>
3992 <anchor id="log-font-size">
3993 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
3995 Font size used in the console window:
3998 <![%config-file;[<literallayout>@@#log-font-size 8</literallayout>]]>
4001 <emphasis>log-font-size 8</emphasis>
4005 <anchor id="show-on-task-bar">
4006 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
4008 <quote>show-on-task-bar</quote> controls whether or not
4009 <application>Privoxy</application> will appear as a button on the Task bar
4013 <![%config-file;[<literallayout>@@#show-on-task-bar 0</literallayout>]]>
4016 <emphasis>show-on-task-bar 0</emphasis>
4020 <anchor id="close-button-minimizes">
4021 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
4023 If <quote>close-button-minimizes</quote> is set to 1, the Windows close
4024 button will minimize <application>Privoxy</application> instead of closing
4025 the program (close with the exit option on the File menu).
4028 <![%config-file;[<literallayout>@@#close-button-minimizes 1</literallayout>]]>
4031 <emphasis>close-button-minimizes 1</emphasis>
4035 <anchor id="hide-console">
4036 <![%config-file;[<para>@@</para>]]> <!-- for spacing -->
4038 The <quote>hide-console</quote> option is specific to the MS-Win console
4039 version of <application>Privoxy</application>. If this option is used,
4040 <application>Privoxy</application> will disconnect from and hide the
4044 <![%config-file;[<literallayout>@@#hide-console</literallayout>]]>
4047 #<emphasis>hide-console</emphasis>
4054 <!-- end config content common to both outputs -->
4057 <!-- These are dummy anchors to keep the processor quiet -->
4058 <!-- when building config-file only (ie. they are used in u-m only) -->
4061 <anchor id="filter">
4062 <anchor id="filter-file">
4064 <anchor id="actions-file">
4065 <anchor id="af-patterns">
4069 <!-- eof p-config.sgml -->