<!entity history SYSTEM "history.sgml">
<!entity copyright SYSTEM "copyright.sgml">
<!entity license SYSTEM "license.sgml">
-<!entity p-version "3.0.22">
+<!entity p-version "3.0.25">
<!entity p-status "UNRELEASED">
<!entity % p-not-stable "INCLUDE">
<!entity % p-stable "IGNORE">
This file belongs into
ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
- $Id: faq.sgml,v 2.107 2014/12/19 12:31:46 fabiankeil Exp $
+ $Id: faq.sgml,v 2.121 2016/05/03 13:21:55 fabiankeil Exp $
- Copyright (C) 2001-2014 Privoxy Developers http://www.privoxy.org/
+ Copyright (C) 2001-2014 Privoxy Developers https://www.privoxy.org/
See LICENSE.
Based partially on the Internet Junkbuster FAQ originally written by and
<!-- Completely the wrong markup, but very little is allowed -->
<!-- in this part of an article. FIXME -->
<link linkend="copyright">Copyright</link> &my-copy; 2001-2014 by
- <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
+ <ulink url="https://www.privoxy.org/">Privoxy Developers</ulink>
</subscript>
</pubdate>
-<pubdate>$Id: faq.sgml,v 2.107 2014/12/19 12:31:46 fabiankeil Exp $</pubdate>
+<pubdate>$Id: faq.sgml,v 2.121 2016/05/03 13:21:55 fabiankeil Exp $</pubdate>
<!--
]]>
<para>
This FAQ gives quick answers to frequently asked questions about
- <ulink url="http://www.privoxy.org/">Privoxy</ulink>.
+ <ulink url="https://www.privoxy.org/">Privoxy</ulink>.
It is not a substitute for the
<ulink url="../user-manual/index.html"><citetitle>Privoxy User Manual</citetitle></ulink>.
<!--
Please note that this document is a work in progress. This copy represents
the state at the release of version &p-version;.
You can find the latest version of the document at <ulink
- url="http://www.privoxy.org/faq/">http://www.privoxy.org/faq/</ulink>.
+ url="https://www.privoxy.org/faq/">https://www.privoxy.org/faq/</ulink>.
Please see the <link linkend="contact">Contact section</link> if you want to
contact the developers.
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="whyprivoxy">Why <quote>Privoxy</quote>? Why change the name from
+<sect2 renderas="sect3" id="whyprivoxy">
+<title>Why <quote>Privoxy</quote>? Why change the name from
Junkbuster at all?</title>
<para>
Though outdated, Junkbusters Corporation continued to offer their original
</sect2>
<sect2 renderas="sect3" id="whatsanad">
-<title id="knows">How does Privoxy know what is
-an ad, and what is not?</title>
+<title>How does Privoxy know what is an ad, and what is not?</title>
<para>
<application>Privoxy</application>'s approach to blocking ads is twofold:
</para>
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="mistakes">Can Privoxy make mistakes?
+<sect2 renderas="sect3" id="mistakes">
+<title>Can Privoxy make mistakes?
This does not sound very scientific.</title>
<para>
Actually, it's a black art ;-) And yes, it is always possible to have a broad
</sect2>
-<sect2 renderas="sect3">
-<title id="configornot">Will I have to configure Privoxy
+<sect2 renderas="sect3" id="configornot">
+<title>Will I have to configure Privoxy
before I can use it?</title>
<para>
That depends on your expectations.
</para>
</sect2>
-<sect2 renderas="sect3" id="help-the-developers"><title id="jointeam">I would like to help you, what can I do?</title>
+<sect2 renderas="sect3" id="help-the-developers"><title>I would like to help you, what can I do?</title>
-<sect3 renderas="sect4" id="participate"><title id="jointeam-work">Would you like to participate?</title>
+<sect3 renderas="sect4" id="participate"><title>Would you like to participate?</title>
<para>
Well, we <emphasis>always</emphasis> need help. There is something for
everybody who wants to help us. We welcome new developers, packagers,
<sect3 renderas="sect4" id="donate"><title>Would you like to donate?</title>
<para>
Donations are welcome. Our
- <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO">TODO list</ulink>
+ <ulink url="http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup">TODO list</ulink>
is rather long and being able to pay one (or more) developers to work on Privoxy
would make a huge difference, even if it was only for a couple of weeks. Donations may
also be used for Privoxy-related travel expenses (for example to attend conferences),
list items you are interested in the most. For example: Max Mustermann: #16, #1, #14.
</para>
+<para>
+ Note that donations made through Zwiebelfreunde e.V. currently can't be checked
+ automatically so you may not get credited right away. The credits currently
+ reflect donations received before 2016-01-14.
+</para>
+
<para>
If you have any questions regarding donations please mail to either the
public user mailing list or, if it's a private matter, to
- <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink> (Privoxy's SPI liason)
+ <ulink url="mailto:fk@fabiankeil.de">Fabian Keil</ulink> (Privoxy's SPI liaison)
directly.
</sect3>
<application>Privoxy</application> is not running at all. Check the <ulink
url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
on starting <application>Privoxy</application> and browser configuration,
- see the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
+ see the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
on starting <application>Privoxy</application></ulink> in the
- <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
+ <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
</para>
</sect2>
First, make sure that Privoxy is <emphasis>really</emphasis> running and
being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
should see the <application>Privoxy</application> main page. If not, see
- the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
+ the <ulink url="https://www.privoxy.org/user-manual/startup.html">chapter
on starting <application>Privoxy</application></ulink> in the
- <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
+ <ulink url="https://www.privoxy.org/user-manual/">User Manual</ulink>.
</para>
<para>
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="configuration"><title>Configuration</title>
-<sect2 renderas="sect3">
-<title id="actionsfile">What exactly is an <quote>actions</quote> file?</title>
+<sect2 renderas="sect3" id="actionsfile">
+<title>What exactly is an <quote>actions</quote> file?</title>
<para>
&my-app; utilizes the concept of <quote>
</sect2>
-<sect2 renderas="sect3">
-<title id="actconfig">How are actions files configured? What is the easiest
+<sect2 renderas="sect3" id="actconfig">
+<title>How are actions files configured? What is the easiest
way to do this?</title>
<para>
Based on your feedback and the continuing development, updates of
<filename>default.action</filename> will be
made available from time to time on the <ulink
- url="http://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
- our <ulink url="http://sf.net/projects/ijbswa/">project page</ulink>.
+ url="https://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
+ our <ulink url="https://sourceforge.net/projects/ijbswa/">project page</ulink>.
</para>
<para>
If you wish to receive an email notification whenever we release updates of
<application>Privoxy</application> or the actions file, <ulink
- url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
+ url="https://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="filterfile">What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
+<sect2 renderas="sect3" id="filterfile">
+<title>What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
<para>
The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
<para>
If you intend to develop your own filters, you might want to have a look at
<ulink
- url="http://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
+ url="https://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test</ulink>.
</para>
</sect2>
</sect2>
-<sect2 renderas="sect3">
-<title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
+<sect2 renderas="sect3" id="noseeum">
+<title>Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
<para>
The replacement for blocked images can be controlled with the <ulink
url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
</sect2>
-<sect2 renderas="sect3">
-<title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
+<sect2 renderas="sect3" id="whyseeum">
+<title>Why would anybody want to see a checkerboard pattern?</title>
<para>
Remember that <link linkend="whatsanad">telling which image is an ad and which
isn't</link>, is an educated guess. While we hope that the standard configuration
</sect2>
-<sect2 renderas="sect3">
-<title id="blockedbytext">I see some images being replaced with text
+<sect2 renderas="sect3" id="blockedbytext">
+<title>I see some images being replaced with text
instead of the checkerboard image. Why and how do I get rid of this?</title>
<para>
This happens when the banners are not embedded in the HTML code of the
<para>
Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
See the discussion at <ulink
- url="http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118">http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</ulink>,
+ url="https://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118">https://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</ulink>,
for details, and a sample configuration.
</para>
</sect2>
<para>
For a good discussion of some of the issues involved (including privacy and
security issues), see
- <ulink url="http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118">http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</ulink>.
+ <ulink url="https://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118">https://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</ulink>.
</para>
</sect2>
<sect1 id="misc"><title>Miscellaneous</title>
-<sect2 renderas="sect3">
-<title id="slowsme">How much does Privoxy slow my browsing down? This
+<sect2 renderas="sect3" id="slowsme">
+<title>How much does Privoxy slow my browsing down? This
has to add extra time to browsing.</title>
<para>
How much of an impact depends on many things, including the CPU of the host
hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
web site at config.privoxy.org.
</para>
+<para>
+ Note that config.privoxy.org resolves to a public IP address.
+ If you use config.privoxy.org as ping or traceroute target you will
+ reach the system on the Internet (Privoxy can't intercept ICMP requests).
+ If you want to ping the system Privoxy runs on,
+ you should use its IP address or local DNS name (if it has got one).
+</para>
</sect2>
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="anonforsure">Can Privoxy guarantee I am anonymous?</title>
+<sect2 renderas="sect3" id="anonforsure">
+<title>Can Privoxy guarantee I am anonymous?</title>
<para>
No. Your chances of remaining anonymous are improved, but unless you
<ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
</sect2>
-<sect2 renderas="sect3">
-<title id="proxytest">A test site says I am not using a Proxy.</title>
+<sect2 renderas="sect3" id="proxytest">
+<title>A test site says I am not using a Proxy.</title>
<para>
Good! Actually, they are probably testing for some other kinds of proxies.
Hiding yourself completely would require additional steps.
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="sitebreak">Might some things break because header information or
+<sect2 renderas="sect3" id="sitebreak">
+<title>Might some things break because header information or
content is being altered?</title>
<para>
</sect2>
-<sect2 renderas="sect3">
-<title id="caching">Can Privoxy act as a <quote>caching</quote> proxy to
+<sect2 renderas="sect3" id="caching">
+<title>Can Privoxy act as a <quote>caching</quote> proxy to
speed up web browsing?</title>
<para>
No, it does not have this ability at all. You want something like
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="firewall">What about as a firewall? Can Privoxy protect me?</title>
+<sect2 renderas="sect3" id="firewall">
+<title>What about as a firewall? Can Privoxy protect me?</title>
<para>
Not in the way you mean, or in the way some firewall vendors claim they can.
<application>Privoxy</application> can help protect your privacy, but can't
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="wasted">I have large empty spaces / a checkerboard pattern now where
+<sect2 renderas="sect3" id="wasted">
+<title>I have large empty spaces / a checkerboard pattern now where
ads used to be. Why?</title>
<para>
It is technically possible to eliminate banners and ads in a way that frees
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="ssl">How can Privoxy filter Secure (HTTPS) URLs?</title>
+<sect2 renderas="sect3" id="ssl">
+<title>How can Privoxy filter Secure (HTTPS) URLs?</title>
<para>
Since secure HTTP connections are encrypted SSL sessions between your browser
and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
</sect2>
-<sect2 renderas="sect3">
-<title id="secure">Privoxy runs as a <quote>server</quote>. How
+<sect2 renderas="sect3" id="secure">
+<title>Privoxy runs as a <quote>server</quote>. How
secure is it? Do I need to take any special precautions?</title>
<para>
On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
</para>
<para>
Lately there have been reports of problems with some kind of
- Privoxy versions that come preinstalled on some Netbooks.
- Some of the problems described are inconsistent with the behaviour
- of official Privoxy versions, which suggests that the preinstalled
- software may contain vendor modifications that we don't know about
- and thus can't debug.
+ "parental control" software based on Privoxy that came preinstalled on
+ certain <ulink url="https://sourceforge.net/p/ijbswa/bugs/813/">ASUS Netbooks</ulink>.
+ The problems described are inconsistent with the behaviour of official
+ Privoxy versions, which suggests that the preinstalled software may
+ contain vendor modifications that we don't know about and thus can't debug.
</para>
<para>
Privoxy's <link linkend="copyright">license</link> allows vendor
<sect1 id="trouble">
<title>Troubleshooting</title>
-<sect2 renderas="sect3">
-<title id="refused">I cannot connect to any websites. Or, I am getting
+<sect2 renderas="sect3" id="refused">
+<title>I cannot connect to any websites. Or, I am getting
<quote>connection refused</quote> message with every web page. Why?</title>
<para>
There are several possibilities:
</para>
</sect2>
-<sect2 renderas="sect3">
-<title id="flushit">I just added a new rule, but the steenkin ad is
+<sect2 renderas="sect3" id="flushit">
+<title>I just added a new rule, but the steenkin ad is
still getting through. How?</title>
<para>
If the ad had been displayed before you added its URL, it will probably be
</sect2>
-<sect2 id="badsite" renderas="sect3">
-<title >One of my favorite sites does not work with Privoxy.
+<sect2 renderas="sect3" id="badsite">
+<title>One of my favorite sites does not work with Privoxy.
What can I do?</title>
<para>
<para>
Upgrading <application>Privoxy</application>, or going to the most recent
<filename>default.action</filename> file available from <ulink
- url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
+ url="https://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>
might be worth a try, too.
</para>
</sect2>
</para>
</sect2>
+<sect2 renderas="sect3" id="tainted-sockets">
+<title>What are tainted sockets and how do I prevent them?</title>
+<para>
+ &my-app; marks sockets as tainted when it can't use them to
+ serve additional requests.
+ This does not necessarily mean that something went wrong and
+ information about tainted sockets is only logged if connection
+ debugging is enabled (debug 2).
+</para>
+<para>
+ For example server sockets that were used for CONNECT requests
+ (which are used to tunnel https:// requests) are considered tainted
+ once the client closed its connection to &my-app;.
+ Technically &my-app; could keep the connection to the server open,
+ but the server would not accept requests that do not belong to the
+ previous TLS/SSL session (and the client may even have terminated
+ the session).
+</para>
+<para>
+ Server sockets are also marked tainted when a client requests a
+ resource, but closes the connection before &my-app; has completely
+ received (and forwarded) the resource to the client.
+ In this case the server would (probably) accept additional requests,
+ but &my-app; could not get the response without completely reading
+ the leftovers from the previous response.
+</para>
+<para>
+ These are just two examples, there are currently a bit more than
+ 25 scenarios in which a socket is considered tainted.
+</para>
+<para>
+ While sockets can also be marked tainted as a result of a technical
+ problem that may be worth fixing, the problem will be explicitly
+ logged as error.
+</para>
+</sect2>
+
+<sect2 renderas="sect3" id="pcre-stack-limit">
+<title>After adding my custom filters, &my-app; crashes when visitting certain websites</title>
+<para>
+ This can happen if your custom filters require more memory than &my-app;
+ is allowed to use.
+ Usually the problem is that the operating system enforces a stack size limit
+ that isn't sufficient.
+</para>
+<para>
+ Unless the problem occurs with the filters available in the default configuration,
+ this is not considered a Privoxy bug.
+</para>
+<para>
+ To prevent the crashes you can rewrite your filter to use less ressources,
+ increase the relevant memory limit or recompile pcre to use less stack space.
+ For details please see the
+ <ulink url="http://pcre.org/original/doc/html/pcrestack.html">pcrestack man page</ulink>
+ and the documentation of your operating system.
+</para>
</sect1>