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41 <h1 class="SECT1"><a name="CONFIG" id="CONFIG">7. The Main Configuration
44 <p>By default, the main configuration file is named <tt class=
45 "FILENAME">config</tt>, with the exception of Windows, where it is named
46 <tt class="FILENAME">config.txt</tt>. Configuration lines consist of an
47 initial keyword followed by a list of values, all separated by whitespace
48 (any number of spaces or tabs). For example:</p>
50 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
51 "emphasis"><i class="EMPHASIS">confdir /etc/privoxy</i></span></tt></p>
53 <p>Assigns the value <tt class="LITERAL">/etc/privoxy</tt> to the option
54 <tt class="LITERAL">confdir</tt> and thus indicates that the
55 configuration directory is named <span class=
56 "QUOTE">"/etc/privoxy/"</span>.</p>
58 <p>All options in the config file except for <tt class=
59 "LITERAL">confdir</tt> and <tt class="LITERAL">logdir</tt> are optional.
60 Watch out in the below description for what happens if you leave them
63 <p>The main config file controls all aspects of <span class=
64 "APPLICATION">Privoxy</span>'s operation that are not location dependent
65 (i.e. they apply universally, no matter where you may be surfing). Like
66 the filter and action files, the config file is a plain text file and can
67 be modified with a text editor like emacs, vim or notepad.exe.</p>
70 <h2 class="SECT2"><a name="LOCAL-SET-UP" id="LOCAL-SET-UP">7.1. Local
71 Set-up Documentation</a></h2>
73 <p>If you intend to operate <span class="APPLICATION">Privoxy</span>
74 for more users than just yourself, it might be a good idea to let them
75 know how to reach you, what you block and why you do that, your
79 <h4 class="SECT3"><a name="USER-MANUAL" id="USER-MANUAL">7.1.1.
82 <div class="VARIABLELIST">
87 <p>Location of the <span class="APPLICATION">Privoxy</span>
91 <dt>Type of value:</dt>
94 <p>A fully qualified URI</p>
97 <dt>Default value:</dt>
100 <p><span class="emphasis"><i class=
101 "EMPHASIS">Unset</i></span></p>
104 <dt>Effect if unset:</dt>
107 <p><a href="http://www.privoxy.org/user-manual/" target=
108 "_top">http://www.privoxy.org/<tt class=
109 "REPLACEABLE"><i>version</i></tt>/user-manual/</a> will be
110 used, where <tt class="REPLACEABLE"><i>version</i></tt> is the
111 <span class="APPLICATION">Privoxy</span> version.</p>
117 <p>The User Manual URI is the single best source of information
118 on <span class="APPLICATION">Privoxy</span>, and is used for
119 help links from some of the internal CGI pages. The manual
120 itself is normally packaged with the binary distributions, so
121 you probably want to set this to a locally installed copy.</p>
125 <p>The best all purpose solution is simply to put the full
126 local <tt class="LITERAL">PATH</tt> to where the <i class=
127 "CITETITLE">User Manual</i> is located:</p>
129 <table border="0" bgcolor="#E0E0E0" width="90%">
133 user-manual /usr/share/doc/privoxy/user-manual
139 <p>The User Manual is then available to anyone with access to
140 <span class="APPLICATION">Privoxy</span>, by following the
141 built-in URL: <tt class=
142 "LITERAL">http://config.privoxy.org/user-manual/</tt> (or the
144 "LITERAL">http://p.p/user-manual/</tt>).</p>
146 <p>If the documentation is not on the local system, it can be
147 accessed from a remote server, as:</p>
149 <table border="0" bgcolor="#E0E0E0" width="90%">
153 user-manual http://example.com/privoxy/user-manual/
159 <div class="WARNING">
160 <table class="WARNING" border="1" width="90%">
162 <td align="center"><b>Warning</b></td>
167 <p>If set, this option should be <span class=
168 "emphasis"><i class="EMPHASIS">the first option in the
169 config file</i></span>, because it is used while the
170 config file is being read on start-up.</p>
181 <h4 class="SECT3"><a name="TRUST-INFO-URL" id="TRUST-INFO-URL">7.1.2.
182 trust-info-url</a></h4>
184 <div class="VARIABLELIST">
189 <p>A URL to be displayed in the error page that users will see
190 if access to an untrusted page is denied.</p>
193 <dt>Type of value:</dt>
199 <dt>Default value:</dt>
202 <p><span class="emphasis"><i class=
203 "EMPHASIS">Unset</i></span></p>
206 <dt>Effect if unset:</dt>
209 <p>No links are displayed on the "untrusted" error page.</p>
215 <p>The value of this option only matters if the experimental
216 trust mechanism has been activated. (See <a href=
217 "config.html#TRUSTFILE"><span class="emphasis"><i class=
218 "EMPHASIS">trustfile</i></span></a> below.)</p>
220 <p>If you use the trust mechanism, it is a good idea to write
221 up some on-line documentation about your trust policy and to
222 specify the URL(s) here. Use multiple times for multiple
225 <p>The URL(s) should be added to the trustfile as well, so
226 users don't end up locked out from the information on why they
227 were locked out in the first place!</p>
234 <h4 class="SECT3"><a name="ADMIN-ADDRESS" id="ADMIN-ADDRESS">7.1.3.
235 admin-address</a></h4>
237 <div class="VARIABLELIST">
242 <p>An email address to reach the <span class=
243 "APPLICATION">Privoxy</span> administrator.</p>
246 <dt>Type of value:</dt>
252 <dt>Default value:</dt>
255 <p><span class="emphasis"><i class=
256 "EMPHASIS">Unset</i></span></p>
259 <dt>Effect if unset:</dt>
262 <p>No email address is displayed on error pages and the CGI
269 <p>If both <tt class="LITERAL">admin-address</tt> and
270 <tt class="LITERAL">proxy-info-url</tt> are unset, the whole
271 "Local Privoxy Support" box on all generated pages will not be
279 <h4 class="SECT3"><a name="PROXY-INFO-URL" id="PROXY-INFO-URL">7.1.4.
280 proxy-info-url</a></h4>
282 <div class="VARIABLELIST">
287 <p>A URL to documentation about the local <span class=
288 "APPLICATION">Privoxy</span> setup, configuration or
292 <dt>Type of value:</dt>
298 <dt>Default value:</dt>
301 <p><span class="emphasis"><i class=
302 "EMPHASIS">Unset</i></span></p>
305 <dt>Effect if unset:</dt>
308 <p>No link to local documentation is displayed on error pages
309 and the CGI user interface.</p>
315 <p>If both <tt class="LITERAL">admin-address</tt> and
316 <tt class="LITERAL">proxy-info-url</tt> are unset, the whole
317 "Local Privoxy Support" box on all generated pages will not be
320 <p>This URL shouldn't be blocked ;-)</p>
328 <h2 class="SECT2"><a name="CONF-LOG-LOC" id="CONF-LOG-LOC">7.2.
329 Configuration and Log File Locations</a></h2>
331 <p><span class="APPLICATION">Privoxy</span> can (and normally does) use
332 a number of other files for additional configuration, help and logging.
333 This section of the configuration file tells <span class=
334 "APPLICATION">Privoxy</span> where to find those other files.</p>
336 <p>The user running <span class="APPLICATION">Privoxy</span>, must have
337 read permission for all configuration files, and write permission to
338 any files that would be modified, such as log files and actions
342 <h4 class="SECT3"><a name="CONFDIR" id="CONFDIR">7.2.1.
345 <div class="VARIABLELIST">
350 <p>The directory where the other configuration files are
354 <dt>Type of value:</dt>
360 <dt>Default value:</dt>
363 <p>/etc/privoxy (Unix) <span class="emphasis"><i class=
364 "EMPHASIS">or</i></span> <span class=
365 "APPLICATION">Privoxy</span> installation dir (Windows)</p>
368 <dt>Effect if unset:</dt>
371 <p><span class="emphasis"><i class=
372 "EMPHASIS">Mandatory</i></span></p>
378 <p>No trailing <span class="QUOTE">"<tt class=
379 "LITERAL">/</tt>"</span>, please.</p>
386 <h4 class="SECT3"><a name="TEMPLDIR" id="TEMPLDIR">7.2.2.
389 <div class="VARIABLELIST">
394 <p>An alternative directory where the templates are loaded
398 <dt>Type of value:</dt>
404 <dt>Default value:</dt>
410 <dt>Effect if unset:</dt>
413 <p>The templates are assumed to be located in
414 confdir/template.</p>
420 <p><span class="APPLICATION">Privoxy's</span> original
421 templates are usually overwritten with each update. Use this
422 option to relocate customized templates that should be kept. As
423 template variables might change between updates, you shouldn't
424 expect templates to work with <span class=
425 "APPLICATION">Privoxy</span> releases other than the one they
426 were part of, though.</p>
433 <h4 class="SECT3"><a name="LOGDIR" id="LOGDIR">7.2.3. logdir</a></h4>
435 <div class="VARIABLELIST">
440 <p>The directory where all logging takes place (i.e. where the
441 <tt class="FILENAME">logfile</tt> is located).</p>
444 <dt>Type of value:</dt>
450 <dt>Default value:</dt>
453 <p>/var/log/privoxy (Unix) <span class="emphasis"><i class=
454 "EMPHASIS">or</i></span> <span class=
455 "APPLICATION">Privoxy</span> installation dir (Windows)</p>
458 <dt>Effect if unset:</dt>
461 <p><span class="emphasis"><i class=
462 "EMPHASIS">Mandatory</i></span></p>
468 <p>No trailing <span class="QUOTE">"<tt class=
469 "LITERAL">/</tt>"</span>, please.</p>
476 <h4 class="SECT3"><a name="ACTIONSFILE" id="ACTIONSFILE">7.2.4.
477 actionsfile</a></h4><a name="DEFAULT.ACTION" id=
478 "DEFAULT.ACTION"></a><a name="STANDARD.ACTION" id=
479 "STANDARD.ACTION"></a><a name="USER.ACTION" id="USER.ACTION"></a>
481 <div class="VARIABLELIST">
486 <p>The <a href="actions-file.html">actions file(s)</a> to
490 <dt>Type of value:</dt>
493 <p>Complete file name, relative to <tt class=
494 "LITERAL">confdir</tt></p>
497 <dt>Default values:</dt>
504 <p class="LITERALLAYOUT">
505 match-all.action # Actions that are applied to all sites and maybe overruled later on.</p>
511 <p class="LITERALLAYOUT">
512 default.action # Main actions file</p>
518 <p class="LITERALLAYOUT">
519 user.action # User customizations</p>
526 <dt>Effect if unset:</dt>
529 <p>No actions are taken at all. More or less neutral
536 <p>Multiple <tt class="LITERAL">actionsfile</tt> lines are
537 permitted, and are in fact recommended!</p>
539 <p>The default values are <tt class=
540 "FILENAME">default.action</tt>, which is the <span class=
541 "QUOTE">"main"</span> actions file maintained by the
542 developers, and <tt class="FILENAME">user.action</tt>, where
543 you can make your personal additions.</p>
545 <p>Actions files contain all the per site and per URL
546 configuration for ad blocking, cookie management, privacy
547 considerations, etc. There is no point in using <span class=
548 "APPLICATION">Privoxy</span> without at least one actions
551 <p>Note that since Privoxy 3.0.7, the complete filename,
552 including the <span class="QUOTE">".action"</span> extension
553 has to be specified. The syntax change was necessary to be
554 consistent with the other file options and to allow previously
555 forbidden characters.</p>
562 <h4 class="SECT3"><a name="FILTERFILE" id="FILTERFILE">7.2.5.
563 filterfile</a></h4><a name="DEFAULT.FILTER" id="DEFAULT.FILTER"></a>
565 <div class="VARIABLELIST">
570 <p>The <a href="filter-file.html">filter file(s)</a> to use</p>
573 <dt>Type of value:</dt>
576 <p>File name, relative to <tt class="LITERAL">confdir</tt></p>
579 <dt>Default value:</dt>
582 <p>default.filter (Unix) <span class="emphasis"><i class=
583 "EMPHASIS">or</i></span> default.filter.txt (Windows)</p>
586 <dt>Effect if unset:</dt>
589 <p>No textual content filtering takes place, i.e. all
590 <tt class="LITERAL">+<a href=
591 "actions-file.html#FILTER">filter</a>{<tt class=
592 "REPLACEABLE"><i>name</i></tt>}</tt> actions in the actions
593 files are turned neutral.</p>
599 <p>Multiple <tt class="LITERAL">filterfile</tt> lines are
602 <p>The <a href="filter-file.html">filter files</a> contain
603 content modification rules that use <a href=
604 "appendix.html#REGEX">regular expressions</a>. These rules
605 permit powerful changes on the content of Web pages, and
606 optionally the headers as well, e.g., you could try to disable
607 your favorite JavaScript annoyances, re-write the actual
608 displayed text, or just have some fun playing buzzword bingo
611 <p>The <tt class="LITERAL">+<a href=
612 "actions-file.html#FILTER">filter</a>{<tt class=
613 "REPLACEABLE"><i>name</i></tt>}</tt> actions rely on the
614 relevant filter (<tt class="REPLACEABLE"><i>name</i></tt>) to
615 be defined in a filter file!</p>
617 <p>A pre-defined filter file called <tt class=
618 "FILENAME">default.filter</tt> that contains a number of useful
619 filters for common problems is included in the distribution.
620 See the section on the <tt class="LITERAL"><a href=
621 "actions-file.html#FILTER">filter</a></tt> action for a
624 <p>It is recommended to place any locally adapted filters into
625 a separate file, such as <tt class=
626 "FILENAME">user.filter</tt>.</p>
633 <h4 class="SECT3"><a name="LOGFILE" id="LOGFILE">7.2.6.
636 <div class="VARIABLELIST">
641 <p>The log file to use</p>
644 <dt>Type of value:</dt>
647 <p>File name, relative to <tt class="LITERAL">logdir</tt></p>
650 <dt>Default value:</dt>
653 <p><span class="emphasis"><i class="EMPHASIS">Unset (commented
654 out)</i></span>. When activated: logfile (Unix) <span class=
655 "emphasis"><i class="EMPHASIS">or</i></span> privoxy.log
659 <dt>Effect if unset:</dt>
662 <p>No logfile is written.</p>
668 <p>The logfile is where all logging and error messages are
669 written. The level of detail and number of messages are set
670 with the <tt class="LITERAL">debug</tt> option (see below). The
671 logfile can be useful for tracking down a problem with
672 <span class="APPLICATION">Privoxy</span> (e.g., it's not
673 blocking an ad you think it should block) and it can help you
674 to monitor what your browser is doing.</p>
676 <p>Depending on the debug options below, the logfile may be a
677 privacy risk if third parties can get access to it. As most
678 users will never look at it, <span class=
679 "APPLICATION">Privoxy</span> 3.0.7 and later only log fatal
680 errors by default.</p>
682 <p>For most troubleshooting purposes, you will have to change
683 that, please refer to the debugging section for details.</p>
685 <p>Your logfile will grow indefinitely, and you will probably
686 want to periodically remove it. On Unix systems, you can do
687 this with a cron job (see <span class="QUOTE">"man
690 <p>Any log files must be writable by whatever user <span class=
691 "APPLICATION">Privoxy</span> is being run as (on Unix, default
692 user id is <span class="QUOTE">"privoxy"</span>).</p>
699 <h4 class="SECT3"><a name="TRUSTFILE" id="TRUSTFILE">7.2.7.
702 <div class="VARIABLELIST">
707 <p>The name of the trust file to use</p>
710 <dt>Type of value:</dt>
713 <p>File name, relative to <tt class="LITERAL">confdir</tt></p>
716 <dt>Default value:</dt>
719 <p><span class="emphasis"><i class="EMPHASIS">Unset (commented
720 out)</i></span>. When activated: trust (Unix) <span class=
721 "emphasis"><i class="EMPHASIS">or</i></span> trust.txt
725 <dt>Effect if unset:</dt>
728 <p>The entire trust mechanism is disabled.</p>
734 <p>The trust mechanism is an experimental feature for building
735 white-lists and should be used with care. It is <span class=
736 "emphasis"><i class="EMPHASIS">NOT</i></span> recommended for
739 <p>If you specify a trust file, <span class=
740 "APPLICATION">Privoxy</span> will only allow access to sites
741 that are specified in the trustfile. Sites can be listed in one
744 <p>Prepending a <tt class="LITERAL">~</tt> character limits
745 access to this site only (and any sub-paths within this site),
746 e.g. <tt class="LITERAL">~www.example.com</tt> allows access to
747 <tt class="LITERAL">~www.example.com/features/news.html</tt>,
750 <p>Or, you can designate sites as <span class=
751 "emphasis"><i class="EMPHASIS">trusted referrers</i></span>, by
752 prepending the name with a <tt class="LITERAL">+</tt>
753 character. The effect is that access to untrusted sites will be
754 granted -- but only if a link from this trusted referrer was
755 used to get there. The link target will then be added to the
756 <span class="QUOTE">"trustfile"</span> so that future, direct
757 accesses will be granted. Sites added via this mechanism do not
758 become trusted referrers themselves (i.e. they are added with a
759 <tt class="LITERAL">~</tt> designation). There is a limit of
760 512 such entries, after which new entries will not be made.</p>
762 <p>If you use the <tt class="LITERAL">+</tt> operator in the
763 trust file, it may grow considerably over time.</p>
765 <p>It is recommended that <span class=
766 "APPLICATION">Privoxy</span> be compiled with the <tt class=
767 "LITERAL">--disable-force</tt>, <tt class=
768 "LITERAL">--disable-toggle</tt> and <tt class=
769 "LITERAL">--disable-editor</tt> options, if this feature is to
772 <p>Possible applications include limiting Internet access for
781 <h2 class="SECT2"><a name="DEBUGGING" id="DEBUGGING">7.3.
784 <p>These options are mainly useful when tracing a problem. Note that
785 you might also want to invoke <span class="APPLICATION">Privoxy</span>
786 with the <tt class="LITERAL">--no-daemon</tt> command line option when
790 <h4 class="SECT3"><a name="DEBUG" id="DEBUG">7.3.1. debug</a></h4>
792 <div class="VARIABLELIST">
797 <p>Key values that determine what information gets logged.</p>
800 <dt>Type of value:</dt>
803 <p>Integer values</p>
806 <dt>Default value:</dt>
809 <p>0 (i.e.: only fatal errors (that cause Privoxy to exit) are
813 <dt>Effect if unset:</dt>
816 <p>Default value is used (see above).</p>
822 <p>The available debug levels are:</p>
824 <table border="0" bgcolor="#E0E0E0" width="90%">
827 <pre class="PROGRAMLISTING">
828 debug 1 # Log the destination for each request <span class=
829 "APPLICATION">Privoxy</span> let through. See also debug 1024.
830 debug 2 # show each connection status
831 debug 4 # show I/O status
832 debug 8 # show header parsing
833 debug 16 # log all data written to the network
834 debug 32 # debug force feature
835 debug 64 # debug regular expression filters
836 debug 128 # debug redirects
837 debug 256 # debug GIF de-animation
838 debug 512 # Common Log Format
839 debug 1024 # Log the destination for requests <span class=
840 "APPLICATION">Privoxy</span> didn't let through, and the reason why.
841 debug 2048 # CGI user interface
842 debug 4096 # Startup banner and warnings.
843 debug 8192 # Non-fatal errors
844 debug 32768 # log all data read from the network
845 debug 65536 # Log the applying actions
851 <p>To select multiple debug levels, you can either add them or
852 use multiple <tt class="LITERAL">debug</tt> lines.</p>
854 <p>A debug level of 1 is informative because it will show you
855 each request as it happens. <span class="emphasis"><i class=
856 "EMPHASIS">1, 1024, 4096 and 8192 are recommended</i></span> so
857 that you will notice when things go wrong. The other levels are
858 probably only of interest if you are hunting down a specific
859 problem. They can produce a hell of an output (especially
862 <p><span class="APPLICATION">Privoxy</span> used to ship with
863 the debug levels recommended above enabled by default, but due
864 to privacy concerns 3.0.7 and later are configured to only log
867 <p>If you are used to the more verbose settings, simply enable
868 the debug lines below again.</p>
870 <p>If you want to use pure CLF (Common Log Format), you should
871 set <span class="QUOTE">"debug 512"</span> <span class=
872 "emphasis"><i class="EMPHASIS">ONLY</i></span> and not enable
875 <p><span class="APPLICATION">Privoxy</span> has a hard-coded
876 limit for the length of log messages. If it's reached, messages
877 are logged truncated and marked with <span class="QUOTE">"...
878 [too long, truncated]"</span>.</p>
880 <p>Please don't file any support requests without trying to
881 reproduce the problem with increased debug level first. Once
882 you read the log messages, you may even be able to solve the
883 problem on your own.</p>
890 <h4 class="SECT3"><a name="SINGLE-THREADED" id=
891 "SINGLE-THREADED">7.3.2. single-threaded</a></h4>
893 <div class="VARIABLELIST">
898 <p>Whether to run only one server thread.</p>
901 <dt>Type of value:</dt>
904 <p><span class="emphasis"><i class="EMPHASIS">1 or
908 <dt>Default value:</dt>
911 <p><span class="emphasis"><i class="EMPHASIS">0</i></span></p>
914 <dt>Effect if unset:</dt>
917 <p>Multi-threaded (or, where unavailable: forked) operation,
918 i.e. the ability to serve multiple requests simultaneously.</p>
924 <p>This option is only there for debugging purposes.
925 <span class="emphasis"><i class="EMPHASIS">It will drastically
926 reduce performance.</i></span></p>
933 <h4 class="SECT3"><a name="HOSTNAME" id="HOSTNAME">7.3.3.
936 <div class="VARIABLELIST">
941 <p>The hostname shown on the CGI pages.</p>
944 <dt>Type of value:</dt>
950 <dt>Default value:</dt>
953 <p><span class="emphasis"><i class=
954 "EMPHASIS">Unset</i></span></p>
957 <dt>Effect if unset:</dt>
960 <p>The hostname provided by the operating system is used.</p>
966 <p>On some misconfigured systems resolving the hostname fails
967 or takes too much time and slows Privoxy down. Setting a fixed
968 hostname works around the problem.</p>
970 <p>In other circumstances it might be desirable to show a
971 hostname other than the one returned by the operating system.
972 For example if the system has several different hostnames and
973 you don't want to use the first one.</p>
975 <p>Note that Privoxy does not validate the specified hostname
984 <h2 class="SECT2"><a name="ACCESS-CONTROL" id="ACCESS-CONTROL">7.4.
985 Access Control and Security</a></h2>
987 <p>This section of the config file controls the security-relevant
988 aspects of <span class="APPLICATION">Privoxy</span>'s
992 <h4 class="SECT3"><a name="LISTEN-ADDRESS" id="LISTEN-ADDRESS">7.4.1.
993 listen-address</a></h4>
995 <div class="VARIABLELIST">
1000 <p>The address and TCP port on which <span class=
1001 "APPLICATION">Privoxy</span> will listen for client
1005 <dt>Type of value:</dt>
1008 <p>[<tt class="REPLACEABLE"><i>IP-Address</i></tt>]:<tt class=
1009 "REPLACEABLE"><i>Port</i></tt></p>
1011 <p>[<tt class="REPLACEABLE"><i>Hostname</i></tt>]:<tt class=
1012 "REPLACEABLE"><i>Port</i></tt></p>
1015 <dt>Default value:</dt>
1018 <p>127.0.0.1:8118</p>
1021 <dt>Effect if unset:</dt>
1024 <p>Bind to 127.0.0.1 (IPv4 localhost), port 8118. This is
1025 suitable and recommended for home users who run <span class=
1026 "APPLICATION">Privoxy</span> on the same machine as their
1033 <p>You will need to configure your browser(s) to this proxy
1034 address and port.</p>
1036 <p>If you already have another service running on port 8118, or
1037 if you want to serve requests from other machines (e.g. on your
1038 local network) as well, you will need to override the
1041 <p>You can use this statement multiple times to make
1042 <span class="APPLICATION">Privoxy</span> listen on more ports
1043 or more <abbr class="ABBREV">IP</abbr> addresses. Suitable if
1044 your operating system does not support sharing <abbr class=
1045 "ABBREV">IPv6</abbr> and <abbr class="ABBREV">IPv4</abbr>
1046 protocols on the same socket.</p>
1048 <p>If a hostname is used instead of an IP address, <span class=
1049 "APPLICATION">Privoxy</span> will try to resolve it to an IP
1050 address and if there are multiple, use the first one
1053 <p>If the address for the hostname isn't already known on the
1054 system (for example because it's in /etc/hostname), this may
1055 result in DNS traffic.</p>
1057 <p>If the specified address isn't available on the system, or
1058 if the hostname can't be resolved, <span class=
1059 "APPLICATION">Privoxy</span> will fail to start.</p>
1061 <p>IPv6 addresses containing colons have to be quoted by
1062 brackets. They can only be used if <span class=
1063 "APPLICATION">Privoxy</span> has been compiled with IPv6
1064 support. If you aren't sure if your version supports it, have a
1066 "LITERAL">http://config.privoxy.org/show-status</tt>.</p>
1068 <p>Some operating systems will prefer IPv6 to IPv4 addresses
1069 even if the system has no IPv6 connectivity which is usually
1070 not expected by the user. Some even rely on DNS to resolve
1071 localhost which mean the "localhost" address used may not
1072 actually be local.</p>
1074 <p>It is therefore recommended to explicitly configure the
1075 intended IP address instead of relying on the operating system,
1076 unless there's a strong reason not to.</p>
1078 <p>If you leave out the address, <span class=
1079 "APPLICATION">Privoxy</span> will bind to all IPv4 interfaces
1080 (addresses) on your machine and may become reachable from the
1081 Internet and/or the local network. Be aware that some GNU/Linux
1082 distributions modify that behaviour without updating the
1083 documentation. Check for non-standard patches if your
1084 <span class="APPLICATION">Privoxy</span> version behaves
1087 <p>If you configure <span class="APPLICATION">Privoxy</span> to
1088 be reachable from the network, consider using <a href=
1089 "config.html#ACLS">access control lists</a> (ACL's, see below),
1090 and/or a firewall.</p>
1092 <p>If you open <span class="APPLICATION">Privoxy</span> to
1093 untrusted users, you will also want to make sure that the
1094 following actions are disabled: <tt class="LITERAL"><a href=
1095 "config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</a></tt>
1096 and <tt class="LITERAL"><a href=
1097 "config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</a></tt></p>
1103 <p>Suppose you are running <span class=
1104 "APPLICATION">Privoxy</span> on a machine which has the address
1105 192.168.0.1 on your local private network (192.168.0.0) and has
1106 another outside connection with a different address. You want
1107 it to serve requests from inside only:</p>
1109 <table border="0" bgcolor="#E0E0E0" width="90%">
1112 <pre class="PROGRAMLISTING">
1113 listen-address 192.168.0.1:8118
1119 <p>Suppose you are running <span class=
1120 "APPLICATION">Privoxy</span> on an IPv6-capable machine and you
1121 want it to listen on the IPv6 address of the loopback
1124 <table border="0" bgcolor="#E0E0E0" width="90%">
1127 <pre class="PROGRAMLISTING">
1128 listen-address [::1]:8118
1139 <h4 class="SECT3"><a name="TOGGLE" id="TOGGLE">7.4.2. toggle</a></h4>
1141 <div class="VARIABLELIST">
1146 <p>Initial state of "toggle" status</p>
1149 <dt>Type of value:</dt>
1155 <dt>Default value:</dt>
1161 <dt>Effect if unset:</dt>
1164 <p>Act as if toggled on</p>
1170 <p>If set to 0, <span class="APPLICATION">Privoxy</span> will
1171 start in <span class="QUOTE">"toggled off"</span> mode, i.e.
1172 mostly behave like a normal, content-neutral proxy with both ad
1173 blocking and content filtering disabled. See <tt class=
1174 "LITERAL">enable-remote-toggle</tt> below.</p>
1181 <h4 class="SECT3"><a name="ENABLE-REMOTE-TOGGLE" id=
1182 "ENABLE-REMOTE-TOGGLE">7.4.3. enable-remote-toggle</a></h4>
1184 <div class="VARIABLELIST">
1189 <p>Whether or not the <a href=
1190 "http://config.privoxy.org/toggle" target="_top">web-based
1191 toggle feature</a> may be used</p>
1194 <dt>Type of value:</dt>
1200 <dt>Default value:</dt>
1206 <dt>Effect if unset:</dt>
1209 <p>The web-based toggle feature is disabled.</p>
1215 <p>When toggled off, <span class="APPLICATION">Privoxy</span>
1216 mostly acts like a normal, content-neutral proxy, i.e. doesn't
1217 block ads or filter content.</p>
1219 <p>Access to the toggle feature can <span class=
1220 "emphasis"><i class="EMPHASIS">not</i></span> be controlled
1221 separately by <span class="QUOTE">"ACLs"</span> or HTTP
1222 authentication, so that everybody who can access <span class=
1223 "APPLICATION">Privoxy</span> (see <span class=
1224 "QUOTE">"ACLs"</span> and <tt class=
1225 "LITERAL">listen-address</tt> above) can toggle it for all
1226 users. So this option is <span class="emphasis"><i class=
1227 "EMPHASIS">not recommended</i></span> for multi-user
1228 environments with untrusted users.</p>
1230 <p>Note that malicious client side code (e.g Java) is also
1231 capable of using this option.</p>
1233 <p>As a lot of <span class="APPLICATION">Privoxy</span> users
1234 don't read documentation, this feature is disabled by
1237 <p>Note that you must have compiled <span class=
1238 "APPLICATION">Privoxy</span> with support for this feature,
1239 otherwise this option has no effect.</p>
1246 <h4 class="SECT3"><a name="ENABLE-REMOTE-HTTP-TOGGLE" id=
1247 "ENABLE-REMOTE-HTTP-TOGGLE">7.4.4. enable-remote-http-toggle</a></h4>
1249 <div class="VARIABLELIST">
1254 <p>Whether or not Privoxy recognizes special HTTP headers to
1255 change its behaviour.</p>
1258 <dt>Type of value:</dt>
1264 <dt>Default value:</dt>
1270 <dt>Effect if unset:</dt>
1273 <p>Privoxy ignores special HTTP headers.</p>
1279 <p>When toggled on, the client can change <span class=
1280 "APPLICATION">Privoxy's</span> behaviour by setting special
1281 HTTP headers. Currently the only supported special header is
1282 <span class="QUOTE">"X-Filter: No"</span>, to disable filtering
1283 for the ongoing request, even if it is enabled in one of the
1286 <p>This feature is disabled by default. If you are using
1287 <span class="APPLICATION">Privoxy</span> in a environment with
1288 trusted clients, you may enable this feature at your
1289 discretion. Note that malicious client side code (e.g Java) is
1290 also capable of using this feature.</p>
1292 <p>This option will be removed in future releases as it has
1293 been obsoleted by the more general header taggers.</p>
1300 <h4 class="SECT3"><a name="ENABLE-EDIT-ACTIONS" id=
1301 "ENABLE-EDIT-ACTIONS">7.4.5. enable-edit-actions</a></h4>
1303 <div class="VARIABLELIST">
1308 <p>Whether or not the <a href=
1309 "http://config.privoxy.org/show-status" target="_top">web-based
1310 actions file editor</a> may be used</p>
1313 <dt>Type of value:</dt>
1319 <dt>Default value:</dt>
1325 <dt>Effect if unset:</dt>
1328 <p>The web-based actions file editor is disabled.</p>
1334 <p>Access to the editor can <span class="emphasis"><i class=
1335 "EMPHASIS">not</i></span> be controlled separately by
1336 <span class="QUOTE">"ACLs"</span> or HTTP authentication, so
1337 that everybody who can access <span class=
1338 "APPLICATION">Privoxy</span> (see <span class=
1339 "QUOTE">"ACLs"</span> and <tt class=
1340 "LITERAL">listen-address</tt> above) can modify its
1341 configuration for all users.</p>
1343 <p>This option is <span class="emphasis"><i class=
1344 "EMPHASIS">not recommended</i></span> for environments with
1345 untrusted users and as a lot of <span class=
1346 "APPLICATION">Privoxy</span> users don't read documentation,
1347 this feature is disabled by default.</p>
1349 <p>Note that malicious client side code (e.g Java) is also
1350 capable of using the actions editor and you shouldn't enable
1351 this options unless you understand the consequences and are
1352 sure your browser is configured correctly.</p>
1354 <p>Note that you must have compiled <span class=
1355 "APPLICATION">Privoxy</span> with support for this feature,
1356 otherwise this option has no effect.</p>
1363 <h4 class="SECT3"><a name="ENFORCE-BLOCKS" id="ENFORCE-BLOCKS">7.4.6.
1364 enforce-blocks</a></h4>
1366 <div class="VARIABLELIST">
1371 <p>Whether the user is allowed to ignore blocks and can
1372 <span class="QUOTE">"go there anyway"</span>.</p>
1375 <dt>Type of value:</dt>
1378 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
1381 <dt>Default value:</dt>
1384 <p><span class="emphasis"><i class="EMPHASIS">0</i></span></p>
1387 <dt>Effect if unset:</dt>
1390 <p>Blocks are not enforced.</p>
1396 <p><span class="APPLICATION">Privoxy</span> is mainly used to
1397 block and filter requests as a service to the user, for example
1398 to block ads and other junk that clogs the pipes. <span class=
1399 "APPLICATION">Privoxy's</span> configuration isn't perfect and
1400 sometimes innocent pages are blocked. In this situation it
1401 makes sense to allow the user to enforce the request and have
1402 <span class="APPLICATION">Privoxy</span> ignore the block.</p>
1404 <p>In the default configuration <span class=
1405 "APPLICATION">Privoxy's</span> <span class=
1406 "QUOTE">"Blocked"</span> page contains a <span class=
1407 "QUOTE">"go there anyway"</span> link to adds a special string
1408 (the force prefix) to the request URL. If that link is used,
1409 <span class="APPLICATION">Privoxy</span> will detect the force
1410 prefix, remove it again and let the request pass.</p>
1412 <p>Of course <span class="APPLICATION">Privoxy</span> can also
1413 be used to enforce a network policy. In that case the user
1414 obviously should not be able to bypass any blocks, and that's
1415 what the <span class="QUOTE">"enforce-blocks"</span> option is
1416 for. If it's enabled, <span class="APPLICATION">Privoxy</span>
1417 hides the <span class="QUOTE">"go there anyway"</span> link. If
1418 the user adds the force prefix by hand, it will not be accepted
1419 and the circumvention attempt is logged.</p>
1425 <p>enforce-blocks 1</p>
1432 <h4 class="SECT3"><a name="ACLS" id="ACLS">7.4.7. ACLs: permit-access
1433 and deny-access</a></h4><a name="PERMIT-ACCESS" id=
1434 "PERMIT-ACCESS"></a><a name="DENY-ACCESS" id="DENY-ACCESS"></a>
1436 <div class="VARIABLELIST">
1441 <p>Who can access what.</p>
1444 <dt>Type of value:</dt>
1447 <p><tt class="REPLACEABLE"><i>src_addr</i></tt>[:<tt class=
1448 "REPLACEABLE"><i>port</i></tt>][/<tt class=
1449 "REPLACEABLE"><i>src_masklen</i></tt>] [<tt class=
1450 "REPLACEABLE"><i>dst_addr</i></tt>[:<tt class=
1451 "REPLACEABLE"><i>port</i></tt>][/<tt class=
1452 "REPLACEABLE"><i>dst_masklen</i></tt>]]</p>
1454 <p>Where <tt class="REPLACEABLE"><i>src_addr</i></tt> and
1455 <tt class="REPLACEABLE"><i>dst_addr</i></tt> are IPv4 addresses
1456 in dotted decimal notation or valid DNS names, <tt class=
1457 "REPLACEABLE"><i>port</i></tt> is a port number, and <tt class=
1458 "REPLACEABLE"><i>src_masklen</i></tt> and <tt class=
1459 "REPLACEABLE"><i>dst_masklen</i></tt> are subnet masks in CIDR
1460 notation, i.e. integer values from 2 to 30 representing the
1461 length (in bits) of the network address. The masks and the
1462 whole destination part are optional.</p>
1464 <p>If your system implements <a href=
1465 "http://tools.ietf.org/html/rfc3493" target="_top">RFC
1466 3493</a>, then <tt class="REPLACEABLE"><i>src_addr</i></tt> and
1467 <tt class="REPLACEABLE"><i>dst_addr</i></tt> can be IPv6
1468 addresses delimeted by brackets, <tt class=
1469 "REPLACEABLE"><i>port</i></tt> can be a number or a service
1470 name, and <tt class="REPLACEABLE"><i>src_masklen</i></tt> and
1471 <tt class="REPLACEABLE"><i>dst_masklen</i></tt> can be a number
1475 <dt>Default value:</dt>
1478 <p><span class="emphasis"><i class=
1479 "EMPHASIS">Unset</i></span></p>
1481 <p>If no <tt class="REPLACEABLE"><i>port</i></tt> is specified,
1482 any port will match. If no <tt class=
1483 "REPLACEABLE"><i>src_masklen</i></tt> or <tt class=
1484 "REPLACEABLE"><i>src_masklen</i></tt> is given, the complete IP
1485 address has to match (i.e. 32 bits for IPv4 and 128 bits for
1489 <dt>Effect if unset:</dt>
1492 <p>Don't restrict access further than implied by <tt class=
1493 "LITERAL">listen-address</tt></p>
1499 <p>Access controls are included at the request of ISPs and
1500 systems administrators, and <span class="emphasis"><i class=
1501 "EMPHASIS">are not usually needed by individual
1502 users</i></span>. For a typical home user, it will normally
1503 suffice to ensure that <span class="APPLICATION">Privoxy</span>
1504 only listens on the localhost (127.0.0.1) or internal (home)
1505 network address by means of the <a href=
1506 "config.html#LISTEN-ADDRESS"><span class="emphasis"><i class=
1507 "EMPHASIS">listen-address</i></span></a> option.</p>
1509 <p>Please see the warnings in the FAQ that <span class=
1510 "APPLICATION">Privoxy</span> is not intended to be a substitute
1511 for a firewall or to encourage anyone to defer addressing basic
1512 security weaknesses.</p>
1514 <p>Multiple ACL lines are OK. If any ACLs are specified,
1515 <span class="APPLICATION">Privoxy</span> only talks to IP
1516 addresses that match at least one <tt class=
1517 "LITERAL">permit-access</tt> line and don't match any
1518 subsequent <tt class="LITERAL">deny-access</tt> line. In other
1519 words, the last match wins, with the default being <tt class=
1520 "LITERAL">deny-access</tt>.</p>
1522 <p>If <span class="APPLICATION">Privoxy</span> is using a
1523 forwarder (see <tt class="LITERAL">forward</tt> below) for a
1524 particular destination URL, the <tt class=
1525 "REPLACEABLE"><i>dst_addr</i></tt> that is examined is the
1526 address of the forwarder and <span class="emphasis"><i class=
1527 "EMPHASIS">NOT</i></span> the address of the ultimate target.
1528 This is necessary because it may be impossible for the local
1529 <span class="APPLICATION">Privoxy</span> to determine the IP
1530 address of the ultimate target (that's often what gateways are
1533 <p>You should prefer using IP addresses over DNS names, because
1534 the address lookups take time. All DNS names must resolve! You
1535 can <span class="emphasis"><i class="EMPHASIS">not</i></span>
1536 use domain patterns like <span class="QUOTE">"*.org"</span> or
1537 partial domain names. If a DNS name resolves to multiple IP
1538 addresses, only the first one is used.</p>
1540 <p>Some systems allow IPv4 clients to connect to IPv6 server
1541 sockets. Then the client's IPv4 address will be translated by
1542 the system into IPv6 address space with special prefix
1543 ::ffff:0:0/96 (so called IPv4 mapped IPv6 address).
1544 <span class="APPLICATION">Privoxy</span> can handle it and maps
1545 such ACL addresses automatically.</p>
1547 <p>Denying access to particular sites by ACL may have undesired
1548 side effects if the site in question is hosted on a machine
1549 which also hosts other sites (most sites are).</p>
1555 <p>Explicitly define the default behavior if no ACL and
1556 <tt class="LITERAL">listen-address</tt> are set: <span class=
1557 "QUOTE">"localhost"</span> is OK. The absence of a <tt class=
1558 "REPLACEABLE"><i>dst_addr</i></tt> implies that <span class=
1559 "emphasis"><i class="EMPHASIS">all</i></span> destination
1560 addresses are OK:</p>
1562 <table border="0" bgcolor="#E0E0E0" width="90%">
1565 <pre class="SCREEN">
1566 permit-access localhost
1572 <p>Allow any host on the same class C subnet as www.privoxy.org
1573 access to nothing but www.example.com (or other domains hosted
1574 on the same system):</p>
1576 <table border="0" bgcolor="#E0E0E0" width="90%">
1579 <pre class="SCREEN">
1580 permit-access www.privoxy.org/24 www.example.com/32
1586 <p>Allow access from any host on the 26-bit subnet
1587 192.168.45.64 to anywhere, with the exception that
1588 192.168.45.73 may not access the IP address behind
1589 www.dirty-stuff.example.com:</p>
1591 <table border="0" bgcolor="#E0E0E0" width="90%">
1594 <pre class="SCREEN">
1595 permit-access 192.168.45.64/26
1596 deny-access 192.168.45.73 www.dirty-stuff.example.com
1602 <p>Allow access from the IPv4 network 192.0.2.0/24 even if
1603 listening on an IPv6 wild card address (not supported on all
1606 <table border="0" bgcolor="#E0E0E0" width="90%">
1609 <pre class="PROGRAMLISTING">
1610 permit-access 192.0.2.0/24
1616 <p>This is equivalent to the following line even if listening
1617 on an IPv4 address (not supported on all platforms):</p>
1619 <table border="0" bgcolor="#E0E0E0" width="90%">
1622 <pre class="PROGRAMLISTING">
1623 permit-access [::ffff:192.0.2.0]/120
1634 <h4 class="SECT3"><a name="BUFFER-LIMIT" id="BUFFER-LIMIT">7.4.8.
1635 buffer-limit</a></h4>
1637 <div class="VARIABLELIST">
1642 <p>Maximum size of the buffer for content filtering.</p>
1645 <dt>Type of value:</dt>
1648 <p>Size in Kbytes</p>
1651 <dt>Default value:</dt>
1657 <dt>Effect if unset:</dt>
1660 <p>Use a 4MB (4096 KB) limit.</p>
1666 <p>For content filtering, i.e. the <tt class=
1667 "LITERAL">+filter</tt> and <tt class=
1668 "LITERAL">+deanimate-gif</tt> actions, it is necessary that
1669 <span class="APPLICATION">Privoxy</span> buffers the entire
1670 document body. This can be potentially dangerous, since a
1671 server could just keep sending data indefinitely and wait for
1672 your RAM to exhaust -- with nasty consequences. Hence this
1675 <p>When a document buffer size reaches the <tt class=
1676 "LITERAL">buffer-limit</tt>, it is flushed to the client
1677 unfiltered and no further attempt to filter the rest of the
1678 document is made. Remember that there may be multiple threads
1679 running, which might require up to <tt class=
1680 "LITERAL">buffer-limit</tt> Kbytes <span class=
1681 "emphasis"><i class="EMPHASIS">each</i></span>, unless you have
1682 enabled <span class="QUOTE">"single-threaded"</span> above.</p>
1689 <h4 class="SECT3"><a name="ENABLE-PROXY-AUTHENTICATION-FORWARDING"
1690 id="ENABLE-PROXY-AUTHENTICATION-FORWARDING">7.4.9.
1691 enable-proxy-authentication-forwarding</a></h4>
1693 <div class="VARIABLELIST">
1698 <p>Whether or not proxy authentication through <span class=
1699 "APPLICATION">Privoxy</span> should work.</p>
1702 <dt>Type of value:</dt>
1708 <dt>Default value:</dt>
1714 <dt>Effect if unset:</dt>
1717 <p>Proxy authentication headers are removed.</p>
1723 <p>Privoxy itself does not support proxy authentication, but
1724 can allow clients to authenticate against Privoxy's parent
1727 <p>By default Privoxy (3.0.21 and later) don't do that and
1728 remove Proxy-Authorization headers in requests and
1729 Proxy-Authenticate headers in responses to make it harder for
1730 malicious sites to trick inexperienced users into providing
1731 login information.</p>
1733 <p>If this option is enabled the headers are forwarded.</p>
1735 <p>Enabling this option is <span class="emphasis"><i class=
1736 "EMPHASIS">not recommended</i></span> if there is no parent
1737 proxy that requires authentication or if the local network
1738 between Privoxy and the parent proxy isn't trustworthy. If
1739 proxy authentication is only required for some requests, it is
1740 recommended to use a client header filter to remove the
1741 authentication headers for requests where they aren't
1750 <h2 class="SECT2"><a name="FORWARDING" id="FORWARDING">7.5.
1753 <p>This feature allows routing of HTTP requests through a chain of
1754 multiple proxies.</p>
1756 <p>Forwarding can be used to chain Privoxy with a caching proxy to
1757 speed up browsing. Using a parent proxy may also be necessary if the
1758 machine that <span class="APPLICATION">Privoxy</span> runs on has no
1759 direct Internet access.</p>
1761 <p>Note that parent proxies can severely decrease your privacy level.
1762 For example a parent proxy could add your IP address to the request
1763 headers and if it's a caching proxy it may add the <span class=
1764 "QUOTE">"Etag"</span> header to revalidation requests again, even
1765 though you configured Privoxy to remove it. It may also ignore
1766 Privoxy's header time randomization and use the original values which
1767 could be used by the server as cookie replacement to track your steps
1770 <p>Also specified here are SOCKS proxies. <span class=
1771 "APPLICATION">Privoxy</span> supports the SOCKS 4 and SOCKS 4A
1775 <h4 class="SECT3"><a name="FORWARD" id="FORWARD">7.5.1.
1778 <div class="VARIABLELIST">
1783 <p>To which parent HTTP proxy specific requests should be
1787 <dt>Type of value:</dt>
1790 <p><tt class="REPLACEABLE"><i>target_pattern</i></tt>
1791 <tt class="REPLACEABLE"><i>http_parent</i></tt>[:<tt class=
1792 "REPLACEABLE"><i>port</i></tt>]</p>
1794 <p>where <tt class="REPLACEABLE"><i>target_pattern</i></tt> is
1795 a <a href="actions-file.html#AF-PATTERNS">URL pattern</a> that
1796 specifies to which requests (i.e. URLs) this forward rule shall
1797 apply. Use <tt class="LITERAL">/</tt> to denote <span class=
1798 "QUOTE">"all URLs"</span>. <tt class=
1799 "REPLACEABLE"><i>http_parent</i></tt>[:<tt class=
1800 "REPLACEABLE"><i>port</i></tt>] is the DNS name or IP address
1801 of the parent HTTP proxy through which the requests should be
1802 forwarded, optionally followed by its listening port (default:
1803 8000). Use a single dot (<tt class="LITERAL">.</tt>) to denote
1804 <span class="QUOTE">"no forwarding"</span>.</p>
1807 <dt>Default value:</dt>
1810 <p><span class="emphasis"><i class=
1811 "EMPHASIS">Unset</i></span></p>
1814 <dt>Effect if unset:</dt>
1817 <p>Don't use parent HTTP proxies.</p>
1823 <p>If <tt class="REPLACEABLE"><i>http_parent</i></tt> is
1824 <span class="QUOTE">"."</span>, then requests are not forwarded
1825 to another HTTP proxy but are made directly to the web
1828 <p><tt class="REPLACEABLE"><i>http_parent</i></tt> can be a
1829 numerical IPv6 address (if <a href=
1830 "http://tools.ietf.org/html/rfc3493" target="_top">RFC 3493</a>
1831 is implemented). To prevent clashes with the port delimiter,
1832 the whole IP address has to be put into brackets. On the other
1833 hand a <tt class="REPLACEABLE"><i>target_pattern</i></tt>
1834 containing an IPv6 address has to be put into angle brackets
1835 (normal brackets are reserved for regular expressions
1838 <p>Multiple lines are OK, they are checked in sequence, and the
1839 last match wins.</p>
1845 <p>Everything goes to an example parent proxy, except SSL on
1846 port 443 (which it doesn't handle):</p>
1848 <table border="0" bgcolor="#E0E0E0" width="90%">
1851 <pre class="SCREEN">
1852 forward / parent-proxy.example.org:8080
1859 <p>Everything goes to our example ISP's caching proxy, except
1860 for requests to that ISP's sites:</p>
1862 <table border="0" bgcolor="#E0E0E0" width="90%">
1865 <pre class="SCREEN">
1866 forward / caching-proxy.isp.example.net:8000
1867 forward .isp.example.net .
1873 <p>Parent proxy specified by an IPv6 address:</p>
1875 <table border="0" bgcolor="#E0E0E0" width="90%">
1878 <pre class="PROGRAMLISTING">
1879 forward / [2001:DB8::1]:8000
1885 <p>Suppose your parent proxy doesn't support IPv6:</p>
1887 <table border="0" bgcolor="#E0E0E0" width="90%">
1890 <pre class="PROGRAMLISTING">
1891 forward / parent-proxy.example.org:8000
1892 forward ipv6-server.example.org .
1893 forward <[2-3][0-9a-f][0-9a-f][0-9a-f]:*> .
1904 <h4 class="SECT3"><a name="SOCKS" id="SOCKS">7.5.2. forward-socks4,
1905 forward-socks4a, forward-socks5 and forward-socks5t</a></h4><a name=
1906 "FORWARD-SOCKS4" id="FORWARD-SOCKS4"></a><a name="FORWARD-SOCKS4A"
1907 id="FORWARD-SOCKS4A"></a>
1909 <div class="VARIABLELIST">
1914 <p>Through which SOCKS proxy (and optionally to which parent
1915 HTTP proxy) specific requests should be routed.</p>
1918 <dt>Type of value:</dt>
1921 <p><tt class="REPLACEABLE"><i>target_pattern</i></tt>
1922 <tt class="REPLACEABLE"><i>socks_proxy</i></tt>[:<tt class=
1923 "REPLACEABLE"><i>port</i></tt>] <tt class=
1924 "REPLACEABLE"><i>http_parent</i></tt>[:<tt class=
1925 "REPLACEABLE"><i>port</i></tt>]</p>
1927 <p>where <tt class="REPLACEABLE"><i>target_pattern</i></tt> is
1928 a <a href="actions-file.html#AF-PATTERNS">URL pattern</a> that
1929 specifies to which requests (i.e. URLs) this forward rule shall
1930 apply. Use <tt class="LITERAL">/</tt> to denote <span class=
1931 "QUOTE">"all URLs"</span>. <tt class=
1932 "REPLACEABLE"><i>http_parent</i></tt> and <tt class=
1933 "REPLACEABLE"><i>socks_proxy</i></tt> are IP addresses in
1934 dotted decimal notation or valid DNS names (<tt class=
1935 "REPLACEABLE"><i>http_parent</i></tt> may be <span class=
1936 "QUOTE">"."</span> to denote <span class="QUOTE">"no HTTP
1937 forwarding"</span>), and the optional <tt class=
1938 "REPLACEABLE"><i>port</i></tt> parameters are TCP ports, i.e.
1939 integer values from 1 to 65535</p>
1942 <dt>Default value:</dt>
1945 <p><span class="emphasis"><i class=
1946 "EMPHASIS">Unset</i></span></p>
1949 <dt>Effect if unset:</dt>
1952 <p>Don't use SOCKS proxies.</p>
1958 <p>Multiple lines are OK, they are checked in sequence, and the
1959 last match wins.</p>
1961 <p>The difference between <tt class=
1962 "LITERAL">forward-socks4</tt> and <tt class=
1963 "LITERAL">forward-socks4a</tt> is that in the SOCKS 4A
1964 protocol, the DNS resolution of the target hostname happens on
1965 the SOCKS server, while in SOCKS 4 it happens locally.</p>
1967 <p>With <tt class="LITERAL">forward-socks5</tt> the DNS
1968 resolution will happen on the remote server as well.</p>
1970 <p><tt class="LITERAL">forward-socks5t</tt> works like vanilla
1971 <tt class="LITERAL">forward-socks5</tt> but lets <span class=
1972 "APPLICATION">Privoxy</span> additionally use Tor-specific
1973 SOCKS extensions. Currently the only supported SOCKS extension
1974 is optimistic data which can reduce the latency for the first
1975 request made on a newly created connection.</p>
1977 <p><tt class="REPLACEABLE"><i>socks_proxy</i></tt> and
1978 <tt class="REPLACEABLE"><i>http_parent</i></tt> can be a
1979 numerical IPv6 address (if <a href=
1980 "http://tools.ietf.org/html/rfc3493" target="_top">RFC 3493</a>
1981 is implemented). To prevent clashes with the port delimiter,
1982 the whole IP address has to be put into brackets. On the other
1983 hand a <tt class="REPLACEABLE"><i>target_pattern</i></tt>
1984 containing an IPv6 address has to be put into angle brackets
1985 (normal brackets are reserved for regular expressions
1988 <p>If <tt class="REPLACEABLE"><i>http_parent</i></tt> is
1989 <span class="QUOTE">"."</span>, then requests are not forwarded
1990 to another HTTP proxy but are made (HTTP-wise) directly to the
1991 web servers, albeit through a SOCKS proxy.</p>
1997 <p>From the company example.com, direct connections are made to
1998 all <span class="QUOTE">"internal"</span> domains, but
1999 everything outbound goes through their ISP's proxy by way of
2000 example.com's corporate SOCKS 4A gateway to the Internet.</p>
2002 <table border="0" bgcolor="#E0E0E0" width="90%">
2005 <pre class="SCREEN">
2006 forward-socks4a / socks-gw.example.com:1080 www-cache.isp.example.net:8080
2007 forward .example.com .
2013 <p>A rule that uses a SOCKS 4 gateway for all destinations but
2014 no HTTP parent looks like this:</p>
2016 <table border="0" bgcolor="#E0E0E0" width="90%">
2019 <pre class="SCREEN">
2020 forward-socks4 / socks-gw.example.com:1080 .
2026 <p>To chain Privoxy and Tor, both running on the same system,
2027 you would use something like:</p>
2029 <table border="0" bgcolor="#E0E0E0" width="90%">
2032 <pre class="SCREEN">
2033 forward-socks5t / 127.0.0.1:9050 .
2039 <p>The public <span class="APPLICATION">Tor</span> network
2040 can't be used to reach your local network, if you need to
2041 access local servers you therefore might want to make some
2044 <table border="0" bgcolor="#E0E0E0" width="90%">
2047 <pre class="SCREEN">
2048 forward 192.168.*.*/ .
2050 forward 127.*.*.*/ .
2056 <p>Unencrypted connections to systems in these address ranges
2057 will be as (un)secure as the local network is, but the
2058 alternative is that you can't reach the local network through
2059 <span class="APPLICATION">Privoxy</span> at all. Of course this
2060 may actually be desired and there is no reason to make these
2061 exceptions if you aren't sure you need them.</p>
2063 <p>If you also want to be able to reach servers in your local
2064 network by using their names, you will need additional
2065 exceptions that look like this:</p>
2067 <table border="0" bgcolor="#E0E0E0" width="90%">
2070 <pre class="SCREEN">
2071 forward localhost/ .
2082 <h4 class="SECT3"><a name="ADVANCED-FORWARDING-EXAMPLES" id=
2083 "ADVANCED-FORWARDING-EXAMPLES">7.5.3. Advanced Forwarding
2086 <p>If you have links to multiple ISPs that provide various special
2087 content only to their subscribers, you can configure multiple
2088 <span class="APPLICATION">Privoxies</span> which have connections to
2089 the respective ISPs to act as forwarders to each other, so that
2090 <span class="emphasis"><i class="EMPHASIS">your</i></span> users can
2091 see the internal content of all ISPs.</p>
2093 <p>Assume that host-a has a PPP connection to isp-a.example.net. And
2094 host-b has a PPP connection to isp-b.example.org. Both run
2095 <span class="APPLICATION">Privoxy</span>. Their forwarding
2096 configuration can look like this:</p>
2100 <table border="0" bgcolor="#E0E0E0" width="100%">
2103 <pre class="SCREEN">
2105 forward .isp-b.example.net host-b:8118
2113 <table border="0" bgcolor="#E0E0E0" width="100%">
2116 <pre class="SCREEN">
2118 forward .isp-a.example.org host-a:8118
2124 <p>Now, your users can set their browser's proxy to use either host-a
2125 or host-b and be able to browse the internal content of both isp-a
2128 <p>If you intend to chain <span class="APPLICATION">Privoxy</span>
2129 and <span class="APPLICATION">squid</span> locally, then chaining as
2130 <tt class="LITERAL">browser -> squid -> privoxy</tt> is the
2131 recommended way.</p>
2133 <p>Assuming that <span class="APPLICATION">Privoxy</span> and
2134 <span class="APPLICATION">squid</span> run on the same box, your
2135 <span class="APPLICATION">squid</span> configuration could then look
2138 <table border="0" bgcolor="#E0E0E0" width="100%">
2141 <pre class="SCREEN">
2142 # Define Privoxy as parent proxy (without ICP)
2143 cache_peer 127.0.0.1 parent 8118 7 no-query
2145 # Define ACL for protocol FTP
2148 # Do not forward FTP requests to Privoxy
2149 always_direct allow ftp
2151 # Forward all the rest to Privoxy
2152 never_direct allow all
2158 <p>You would then need to change your browser's proxy settings to
2159 <span class="APPLICATION">squid</span>'s address and port. Squid
2160 normally uses port 3128. If unsure consult <tt class=
2161 "LITERAL">http_port</tt> in <tt class="FILENAME">squid.conf</tt>.</p>
2163 <p>You could just as well decide to only forward requests you suspect
2164 of leading to Windows executables through a virus-scanning parent
2165 proxy, say, on <tt class="LITERAL">antivir.example.com</tt>, port
2168 <table border="0" bgcolor="#E0E0E0" width="100%">
2171 <pre class="SCREEN">
2173 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
2181 <h4 class="SECT3"><a name="FORWARDED-CONNECT-RETRIES" id=
2182 "FORWARDED-CONNECT-RETRIES">7.5.4. forwarded-connect-retries</a></h4>
2184 <div class="VARIABLELIST">
2189 <p>How often Privoxy retries if a forwarded connection request
2193 <dt>Type of value:</dt>
2196 <p><tt class="REPLACEABLE"><i>Number of retries.</i></tt></p>
2199 <dt>Default value:</dt>
2202 <p><span class="emphasis"><i class="EMPHASIS">0</i></span></p>
2205 <dt>Effect if unset:</dt>
2208 <p>Connections forwarded through other proxies are treated like
2209 direct connections and no retry attempts are made.</p>
2216 "REPLACEABLE"><i>forwarded-connect-retries</i></tt> is mainly
2217 interesting for socks4a connections, where <span class=
2218 "APPLICATION">Privoxy</span> can't detect why the connections
2219 failed. The connection might have failed because of a DNS
2220 timeout in which case a retry makes sense, but it might also
2221 have failed because the server doesn't exist or isn't
2222 reachable. In this case the retry will just delay the
2223 appearance of Privoxy's error message.</p>
2225 <p>Note that in the context of this option, <span class=
2226 "QUOTE">"forwarded connections"</span> includes all connections
2227 that Privoxy forwards through other proxies. This option is not
2228 limited to the HTTP CONNECT method.</p>
2230 <p>Only use this option, if you are getting lots of
2231 forwarding-related error messages that go away when you try
2232 again manually. Start with a small value and check Privoxy's
2233 logfile from time to time, to see how many retries are usually
2240 <p>forwarded-connect-retries 1</p>
2248 <h2 class="SECT2"><a name="MISC" id="MISC">7.6. Miscellaneous</a></h2>
2251 <h4 class="SECT3"><a name="ACCEPT-INTERCEPTED-REQUESTS" id=
2252 "ACCEPT-INTERCEPTED-REQUESTS">7.6.1.
2253 accept-intercepted-requests</a></h4>
2255 <div class="VARIABLELIST">
2260 <p>Whether intercepted requests should be treated as valid.</p>
2263 <dt>Type of value:</dt>
2266 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
2269 <dt>Default value:</dt>
2272 <p><span class="emphasis"><i class="EMPHASIS">0</i></span></p>
2275 <dt>Effect if unset:</dt>
2278 <p>Only proxy requests are accepted, intercepted requests are
2279 treated as invalid.</p>
2285 <p>If you don't trust your clients and want to force them to
2286 use <span class="APPLICATION">Privoxy</span>, enable this
2287 option and configure your packet filter to redirect outgoing
2288 HTTP connections into <span class=
2289 "APPLICATION">Privoxy</span>.</p>
2291 <p>Note that intercepting encrypted connections (HTTPS) isn't
2294 <p>Make sure that <span class="APPLICATION">Privoxy's</span>
2295 own requests aren't redirected as well. Additionally take care
2296 that <span class="APPLICATION">Privoxy</span> can't
2297 intentionally connect to itself, otherwise you could run into
2298 redirection loops if <span class="APPLICATION">Privoxy's</span>
2299 listening port is reachable by the outside or an attacker has
2300 access to the pages you visit.</p>
2306 <p>accept-intercepted-requests 1</p>
2313 <h4 class="SECT3"><a name="ALLOW-CGI-REQUEST-CRUNCHING" id=
2314 "ALLOW-CGI-REQUEST-CRUNCHING">7.6.2.
2315 allow-cgi-request-crunching</a></h4>
2317 <div class="VARIABLELIST">
2322 <p>Whether requests to <span class=
2323 "APPLICATION">Privoxy's</span> CGI pages can be blocked or
2327 <dt>Type of value:</dt>
2330 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
2333 <dt>Default value:</dt>
2336 <p><span class="emphasis"><i class="EMPHASIS">0</i></span></p>
2339 <dt>Effect if unset:</dt>
2342 <p><span class="APPLICATION">Privoxy</span> ignores block and
2343 redirect actions for its CGI pages.</p>
2349 <p>By default <span class="APPLICATION">Privoxy</span> ignores
2350 block or redirect actions for its CGI pages. Intercepting these
2351 requests can be useful in multi-user setups to implement
2352 fine-grained access control, but it can also render the
2353 complete web interface useless and make debugging problems
2354 painful if done without care.</p>
2356 <p>Don't enable this option unless you're sure that you really
2363 <p>allow-cgi-request-crunching 1</p>
2370 <h4 class="SECT3"><a name="SPLIT-LARGE-FORMS" id=
2371 "SPLIT-LARGE-FORMS">7.6.3. split-large-forms</a></h4>
2373 <div class="VARIABLELIST">
2378 <p>Whether the CGI interface should stay compatible with broken
2382 <dt>Type of value:</dt>
2385 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
2388 <dt>Default value:</dt>
2391 <p><span class="emphasis"><i class="EMPHASIS">0</i></span></p>
2394 <dt>Effect if unset:</dt>
2397 <p>The CGI form generate long GET URLs.</p>
2403 <p><span class="APPLICATION">Privoxy's</span> CGI forms can
2404 lead to rather long URLs. This isn't a problem as far as the
2405 HTTP standard is concerned, but it can confuse clients with
2406 arbitrary URL length limitations.</p>
2408 <p>Enabling split-large-forms causes <span class=
2409 "APPLICATION">Privoxy</span> to divide big forms into smaller
2410 ones to keep the URL length down. It makes editing a lot less
2411 convenient and you can no longer submit all changes at once,
2412 but at least it works around this browser bug.</p>
2414 <p>If you don't notice any editing problems, there is no reason
2415 to enable this option, but if one of the submit buttons appears
2416 to be broken, you should give it a try.</p>
2422 <p>split-large-forms 1</p>
2429 <h4 class="SECT3"><a name="KEEP-ALIVE-TIMEOUT" id=
2430 "KEEP-ALIVE-TIMEOUT">7.6.4. keep-alive-timeout</a></h4>
2432 <div class="VARIABLELIST">
2437 <p>Number of seconds after which an open connection will no
2438 longer be reused.</p>
2441 <dt>Type of value:</dt>
2444 <p><tt class="REPLACEABLE"><i>Time in seconds.</i></tt></p>
2447 <dt>Default value:</dt>
2453 <dt>Effect if unset:</dt>
2456 <p>Connections are not kept alive.</p>
2462 <p>This option allows clients to keep the connection to
2463 <span class="APPLICATION">Privoxy</span> alive. If the server
2464 supports it, <span class="APPLICATION">Privoxy</span> will keep
2465 the connection to the server alive as well. Under certain
2466 circumstances this may result in speed-ups.</p>
2468 <p>By default, <span class="APPLICATION">Privoxy</span> will
2469 close the connection to the server if the client connection
2470 gets closed, or if the specified timeout has been reached
2471 without a new request coming in. This behaviour can be changed
2472 with the <a href="#CONNECTION-SHARING" target=
2473 "_top">connection-sharing</a> option.</p>
2475 <p>This option has no effect if <span class=
2476 "APPLICATION">Privoxy</span> has been compiled without
2477 keep-alive support.</p>
2479 <p>Note that a timeout of five seconds as used in the default
2480 configuration file significantly decreases the number of
2481 connections that will be reused. The value is used because some
2482 browsers limit the number of connections they open to a single
2483 host and apply the same limit to proxies. This can result in a
2484 single website <span class="QUOTE">"grabbing"</span> all the
2485 connections the browser allows, which means connections to
2486 other websites can't be opened until the connections currently
2487 in use time out.</p>
2489 <p>Several users have reported this as a Privoxy bug, so the
2490 default value has been reduced. Consider increasing it to 300
2491 seconds or even more if you think your browser can handle it.
2492 If your browser appears to be hanging, it probably can't.</p>
2498 <p>keep-alive-timeout 300</p>
2505 <h4 class="SECT3"><a name="TOLERATE-PIPELINING" id=
2506 "TOLERATE-PIPELINING">7.6.5. tolerate-pipelining</a></h4>
2508 <div class="VARIABLELIST">
2513 <p>Whether or not pipelined requests should be served.</p>
2516 <dt>Type of value:</dt>
2519 <p><tt class="REPLACEABLE"><i>0 or 1.</i></tt></p>
2522 <dt>Default value:</dt>
2528 <dt>Effect if unset:</dt>
2531 <p>If Privoxy receives more than one request at once, it
2532 terminates the client connection after serving the first
2539 <p><span class="APPLICATION">Privoxy</span> currently doesn't
2540 pipeline outgoing requests, thus allowing pipelining on the
2541 client connection is not guaranteed to improve the
2544 <p>By default <span class="APPLICATION">Privoxy</span> tries to
2545 discourage clients from pipelining by discarding aggressively
2546 pipelined requests, which forces the client to resend them
2547 through a new connection.</p>
2549 <p>This option lets <span class="APPLICATION">Privoxy</span>
2550 tolerate pipelining. Whether or not that improves performance
2551 mainly depends on the client configuration.</p>
2553 <p>If you are seeing problems with pages not properly loading,
2554 disabling this option could work around the problem.</p>
2560 <p>tolerate-pipelining 1</p>
2567 <h4 class="SECT3"><a name="DEFAULT-SERVER-TIMEOUT" id=
2568 "DEFAULT-SERVER-TIMEOUT">7.6.6. default-server-timeout</a></h4>
2570 <div class="VARIABLELIST">
2575 <p>Assumed server-side keep-alive timeout if not specified by
2579 <dt>Type of value:</dt>
2582 <p><tt class="REPLACEABLE"><i>Time in seconds.</i></tt></p>
2585 <dt>Default value:</dt>
2591 <dt>Effect if unset:</dt>
2594 <p>Connections for which the server didn't specify the
2595 keep-alive timeout are not reused.</p>
2601 <p>Enabling this option significantly increases the number of
2602 connections that are reused, provided the <a href=
2603 "#KEEP-ALIVE-TIMEOUT" target="_top">keep-alive-timeout</a>
2604 option is also enabled.</p>
2606 <p>While it also increases the number of connections problems
2607 when <span class="APPLICATION">Privoxy</span> tries to reuse a
2608 connection that already has been closed on the server side, or
2609 is closed while <span class="APPLICATION">Privoxy</span> is
2610 trying to reuse it, this should only be a problem if it happens
2611 for the first request sent by the client. If it happens for
2612 requests on reused client connections, <span class=
2613 "APPLICATION">Privoxy</span> will simply close the connection
2614 and the client is supposed to retry the request without
2615 bothering the user.</p>
2617 <p>Enabling this option is therefore only recommended if the
2618 <a href="#CONNECTION-SHARING" target=
2619 "_top">connection-sharing</a> option is disabled.</p>
2621 <p>It is an error to specify a value larger than the <a href=
2622 "#KEEP-ALIVE-TIMEOUT" target="_top">keep-alive-timeout</a>
2625 <p>This option has no effect if <span class=
2626 "APPLICATION">Privoxy</span> has been compiled without
2627 keep-alive support.</p>
2633 <p>default-server-timeout 60</p>
2640 <h4 class="SECT3"><a name="CONNECTION-SHARING" id=
2641 "CONNECTION-SHARING">7.6.7. connection-sharing</a></h4>
2643 <div class="VARIABLELIST">
2648 <p>Whether or not outgoing connections that have been kept
2649 alive should be shared between different incoming
2653 <dt>Type of value:</dt>
2656 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
2659 <dt>Default value:</dt>
2665 <dt>Effect if unset:</dt>
2668 <p>Connections are not shared.</p>
2674 <p>This option has no effect if <span class=
2675 "APPLICATION">Privoxy</span> has been compiled without
2676 keep-alive support, or if it's disabled.</p>
2682 <p>Note that reusing connections doesn't necessary cause
2683 speedups. There are also a few privacy implications you should
2686 <p>If this option is effective, outgoing connections are shared
2687 between clients (if there are more than one) and closing the
2688 browser that initiated the outgoing connection does no longer
2689 affect the connection between <span class=
2690 "APPLICATION">Privoxy</span> and the server unless the client's
2691 request hasn't been completed yet.</p>
2693 <p>If the outgoing connection is idle, it will not be closed
2694 until either <span class="APPLICATION">Privoxy's</span> or the
2695 server's timeout is reached. While it's open, the server knows
2696 that the system running <span class=
2697 "APPLICATION">Privoxy</span> is still there.</p>
2699 <p>If there are more than one client (maybe even belonging to
2700 multiple users), they will be able to reuse each others
2701 connections. This is potentially dangerous in case of
2702 authentication schemes like NTLM where only the connection is
2703 authenticated, instead of requiring authentication for each
2706 <p>If there is only a single client, and if said client can
2707 keep connections alive on its own, enabling this option has
2708 next to no effect. If the client doesn't support connection
2709 keep-alive, enabling this option may make sense as it allows
2710 <span class="APPLICATION">Privoxy</span> to keep outgoing
2711 connections alive even if the client itself doesn't support
2714 <p>You should also be aware that enabling this option increases
2715 the likelihood of getting the "No server or forwarder data"
2716 error message, especially if you are using a slow connection to
2719 <p>This option should only be used by experienced users who
2720 understand the risks and can weight them against the
2727 <p>connection-sharing 1</p>
2734 <h4 class="SECT3"><a name="SOCKET-TIMEOUT" id="SOCKET-TIMEOUT">7.6.8.
2735 socket-timeout</a></h4>
2737 <div class="VARIABLELIST">
2742 <p>Number of seconds after which a socket times out if no data
2746 <dt>Type of value:</dt>
2749 <p><tt class="REPLACEABLE"><i>Time in seconds.</i></tt></p>
2752 <dt>Default value:</dt>
2758 <dt>Effect if unset:</dt>
2761 <p>A default value of 300 seconds is used.</p>
2767 <p>The default is quite high and you probably want to reduce
2768 it. If you aren't using an occasionally slow proxy like Tor,
2769 reducing it to a few seconds should be fine.</p>
2775 <p>socket-timeout 300</p>
2782 <h4 class="SECT3"><a name="MAX-CLIENT-CONNECTIONS" id=
2783 "MAX-CLIENT-CONNECTIONS">7.6.9. max-client-connections</a></h4>
2785 <div class="VARIABLELIST">
2790 <p>Maximum number of client connections that will be
2794 <dt>Type of value:</dt>
2797 <p><tt class="REPLACEABLE"><i>Positive number.</i></tt></p>
2800 <dt>Default value:</dt>
2806 <dt>Effect if unset:</dt>
2809 <p>Connections are served until a resource limit is
2816 <p><span class="APPLICATION">Privoxy</span> creates one thread
2817 (or process) for every incoming client connection that isn't
2818 rejected based on the access control settings.</p>
2820 <p>If the system is powerful enough, <span class=
2821 "APPLICATION">Privoxy</span> can theoretically deal with
2822 several hundred (or thousand) connections at the same time, but
2823 some operating systems enforce resource limits by shutting down
2824 offending processes and their default limits may be below the
2825 ones <span class="APPLICATION">Privoxy</span> would require
2826 under heavy load.</p>
2828 <p>Configuring <span class="APPLICATION">Privoxy</span> to
2829 enforce a connection limit below the thread or process limit
2830 used by the operating system makes sure this doesn't happen.
2831 Simply increasing the operating system's limit would work too,
2832 but if <span class="APPLICATION">Privoxy</span> isn't the only
2833 application running on the system, you may actually want to
2834 limit the resources used by <span class=
2835 "APPLICATION">Privoxy</span>.</p>
2837 <p>If <span class="APPLICATION">Privoxy</span> is only used by
2838 a single trusted user, limiting the number of client
2839 connections is probably unnecessary. If there are multiple
2840 possibly untrusted users you probably still want to
2841 additionally use a packet filter to limit the maximal number of
2842 incoming connections per client. Otherwise a malicious user
2843 could intentionally create a high number of connections to
2844 prevent other users from using <span class=
2845 "APPLICATION">Privoxy</span>.</p>
2847 <p>Obviously using this option only makes sense if you choose a
2848 limit below the one enforced by the operating system.</p>
2850 <p>One most POSIX-compliant systems <span class=
2851 "APPLICATION">Privoxy</span> can't properly deal with more than
2852 FD_SETSIZE file descriptors at the same time and has to reject
2853 connections if the limit is reached. This will likely change in
2854 a future version, but currently this limit can't be increased
2855 without recompiling <span class="APPLICATION">Privoxy</span>
2856 with a different FD_SETSIZE limit.</p>
2862 <p>max-client-connections 256</p>
2869 <h4 class="SECT3"><a name="HANDLE-AS-EMPTY-DOC-RETURNS-OK" id=
2870 "HANDLE-AS-EMPTY-DOC-RETURNS-OK">7.6.10.
2871 handle-as-empty-doc-returns-ok</a></h4>
2873 <div class="VARIABLELIST">
2878 <p>The status code Privoxy returns for pages blocked with
2879 <tt class="LITERAL"><a href=
2880 "actions-file.html#HANDLE-AS-EMPTY-DOCUMENT" target=
2881 "_top">+handle-as-empty-document</a></tt>.</p>
2884 <dt>Type of value:</dt>
2887 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
2890 <dt>Default value:</dt>
2896 <dt>Effect if unset:</dt>
2899 <p>Privoxy returns a status 403(forbidden) for all blocked
2903 <dt>Effect if set:</dt>
2906 <p>Privoxy returns a status 200(OK) for pages blocked with
2907 +handle-as-empty-document and a status 403(Forbidden) for all
2908 other blocked pages.</p>
2914 <p>This is a work-around for Firefox bug 492459: <span class=
2915 "QUOTE">" Websites are no longer rendered if SSL requests for
2916 JavaScripts are blocked by a proxy. "</span> (<a href=
2917 "https://bugzilla.mozilla.org/show_bug.cgi?id=492459" target=
2918 "_top">https://bugzilla.mozilla.org/show_bug.cgi?id=492459</a>)
2919 As the bug has been fixed for quite some time this option
2920 should no longer be needed and will be removed in a future
2921 release. Please speak up if you have a reason why the option
2922 should be kept around.</p>
2929 <h4 class="SECT3"><a name="ENABLE-COMPRESSION" id=
2930 "ENABLE-COMPRESSION">7.6.11. enable-compression</a></h4>
2932 <div class="VARIABLELIST">
2937 <p>Whether or not buffered content is compressed before
2941 <dt>Type of value:</dt>
2944 <p><tt class="REPLACEABLE"><i>0 or 1</i></tt></p>
2947 <dt>Default value:</dt>
2953 <dt>Effect if unset:</dt>
2956 <p>Privoxy does not compress buffered content.</p>
2959 <dt>Effect if set:</dt>
2962 <p>Privoxy compresses buffered content before delivering it to
2963 the client, provided the client supports it.</p>
2969 <p>This directive is only supported if Privoxy has been
2970 compiled with FEATURE_COMPRESSION, which should not to be
2971 confused with FEATURE_ZLIB.</p>
2973 <p>Compressing buffered content is mainly useful if Privoxy and
2974 the client are running on different systems. If they are
2975 running on the same system, enabling compression is likely to
2976 slow things down. If you didn't measure otherwise, you should
2977 assume that it does and keep this option disabled.</p>
2979 <p>Privoxy will not compress buffered content below a certain
2987 <h4 class="SECT3"><a name="COMPRESSION-LEVEL" id=
2988 "COMPRESSION-LEVEL">7.6.12. compression-level</a></h4>
2990 <div class="VARIABLELIST">
2995 <p>The compression level that is passed to the zlib library
2996 when compressing buffered content.</p>
2999 <dt>Type of value:</dt>
3002 <p><tt class="REPLACEABLE"><i>Positive number ranging from 0 to
3006 <dt>Default value:</dt>
3015 <p>Compressing the data more takes usually longer than
3016 compressing it less or not compressing it at all. Which level
3017 is best depends on the connection between Privoxy and the
3018 client. If you can't be bothered to benchmark it for yourself,
3019 you should stick with the default and keep compression
3022 <p>If compression is disabled, the compression level is
3029 <table border="0" bgcolor="#E0E0E0" width="90%">
3032 <pre class="SCREEN">
3033 # Best speed (compared to the other levels)
3037 # No compression. Only useful for testing as the added header
3038 # slightly increases the amount of data that has to be sent.
3039 # If your benchmark shows that using this compression level
3040 # is superior to using no compression at all, the benchmark
3041 # is likely to be flawed.
3054 <h4 class="SECT3"><a name="CLIENT-HEADER-ORDER" id=
3055 "CLIENT-HEADER-ORDER">7.6.13. client-header-order</a></h4>
3057 <div class="VARIABLELIST">
3062 <p>The order in which client headers are sorted before
3063 forwarding them.</p>
3066 <dt>Type of value:</dt>
3069 <p><tt class="REPLACEABLE"><i>Client header names delimited by
3070 spaces or tabs</i></tt></p>
3073 <dt>Default value:</dt>
3082 <p>By default <span class="APPLICATION">Privoxy</span> leaves
3083 the client headers in the order they were sent by the client.
3084 Headers are modified in-place, new headers are added at the end
3085 of the already existing headers.</p>
3087 <p>The header order can be used to fingerprint client requests
3088 independently of other headers like the User-Agent.</p>
3090 <p>This directive allows to sort the headers differently to
3091 better mimic a different User-Agent. Client headers will be
3092 emitted in the order given, headers whose name isn't explicitly
3093 specified are added at the end.</p>
3095 <p>Note that sorting headers in an uncommon way will make
3096 fingerprinting actually easier. Encrypted headers are not
3097 affected by this directive.</p>
3105 <h2 class="SECT2"><a name="WINDOWS-GUI" id="WINDOWS-GUI">7.7. Windows
3106 GUI Options</a></h2>
3108 <p><span class="APPLICATION">Privoxy</span> has a number of options
3109 specific to the Windows GUI interface:</p><a name="ACTIVITY-ANIMATION"
3110 id="ACTIVITY-ANIMATION"></a>
3112 <p>If <span class="QUOTE">"activity-animation"</span> is set to 1, the
3113 <span class="APPLICATION">Privoxy</span> icon will animate when
3114 <span class="QUOTE">"Privoxy"</span> is active. To turn off, set to
3117 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3118 "emphasis"><i class="EMPHASIS">activity-animation 1</i></span><br>
3119 </tt></p><a name="LOG-MESSAGES" id=
3122 <p>If <span class="QUOTE">"log-messages"</span> is set to 1,
3123 <span class="APPLICATION">Privoxy</span> copies log messages to the
3124 console window. The log detail depends on the <a href=
3125 "config.html#DEBUG">debug</a> directive.</p>
3127 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3128 "emphasis"><i class="EMPHASIS">log-messages 1</i></span><br>
3129 </tt></p><a name="LOG-BUFFER-SIZE" id=
3130 "LOG-BUFFER-SIZE"></a>
3132 <p>If <span class="QUOTE">"log-buffer-size"</span> is set to 1, the
3133 size of the log buffer, i.e. the amount of memory used for the log
3134 messages displayed in the console window, will be limited to
3135 <span class="QUOTE">"log-max-lines"</span> (see below).</p>
3137 <p>Warning: Setting this to 0 will result in the buffer to grow
3138 infinitely and eat up all your memory!</p>
3140 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3141 "emphasis"><i class="EMPHASIS">log-buffer-size 1</i></span><br>
3142 </tt></p><a name="LOG-MAX-LINES" id=
3143 "LOG-MAX-LINES"></a>
3145 <p><span class="APPLICATION">log-max-lines</span> is the maximum number
3146 of lines held in the log buffer. See above.</p>
3148 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3149 "emphasis"><i class="EMPHASIS">log-max-lines 200</i></span><br>
3150 </tt></p><a name="LOG-HIGHLIGHT-MESSAGES" id=
3151 "LOG-HIGHLIGHT-MESSAGES"></a>
3153 <p>If <span class="QUOTE">"log-highlight-messages"</span> is set to 1,
3154 <span class="APPLICATION">Privoxy</span> will highlight portions of the
3155 log messages with a bold-faced font:</p>
3157 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3158 "emphasis"><i class="EMPHASIS">log-highlight-messages 1</i></span><br>
3159 </tt></p><a name="LOG-FONT-NAME" id=
3160 "LOG-FONT-NAME"></a>
3162 <p>The font used in the console window:</p>
3164 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3165 "emphasis"><i class="EMPHASIS">log-font-name Comic Sans
3167 </tt></p><a name="LOG-FONT-SIZE" id=
3168 "LOG-FONT-SIZE"></a>
3170 <p>Font size used in the console window:</p>
3172 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3173 "emphasis"><i class="EMPHASIS">log-font-size 8</i></span><br>
3174 </tt></p><a name="SHOW-ON-TASK-BAR" id=
3175 "SHOW-ON-TASK-BAR"></a>
3177 <p><span class="QUOTE">"show-on-task-bar"</span> controls whether or
3178 not <span class="APPLICATION">Privoxy</span> will appear as a button on
3179 the Task bar when minimized:</p>
3181 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3182 "emphasis"><i class="EMPHASIS">show-on-task-bar 0</i></span><br>
3183 </tt></p><a name="CLOSE-BUTTON-MINIMIZES" id=
3184 "CLOSE-BUTTON-MINIMIZES"></a>
3186 <p>If <span class="QUOTE">"close-button-minimizes"</span> is set to 1,
3187 the Windows close button will minimize <span class=
3188 "APPLICATION">Privoxy</span> instead of closing the program (close with
3189 the exit option on the File menu).</p>
3191 <p class="LITERALLAYOUT"><tt class="LITERAL"> <span class=
3192 "emphasis"><i class="EMPHASIS">close-button-minimizes 1</i></span><br>
3193 </tt></p><a name="HIDE-CONSOLE" id=
3196 <p>The <span class="QUOTE">"hide-console"</span> option is specific to
3197 the MS-Win console version of <span class="APPLICATION">Privoxy</span>.
3198 If this option is used, <span class="APPLICATION">Privoxy</span> will
3199 disconnect from and hide the command console.</p>
3201 <p class="LITERALLAYOUT"><tt class="LITERAL"> #<span class=
3202 "emphasis"><i class="EMPHASIS">hide-console</i></span><br>
3203 </tt></p>
3207 <div class="NAVFOOTER">
3208 <hr align="left" width="100%">
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