X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Fsource%2Ffaq.sgml;h=650d0552de1f6fa92eb70bfba92ef792f2dcc89a;hp=6e10b1b8c52b84f484f5bd25db4ad5ed79a46679;hb=6aa484852b4b0b7efcc3fdff38122b920a9b52be;hpb=2bfb21bf1eed857e7c7ea7975b1a596b2721522d diff --git a/doc/source/faq.sgml b/doc/source/faq.sgml index 6e10b1b8..650d0552 100644 --- a/doc/source/faq.sgml +++ b/doc/source/faq.sgml @@ -8,7 +8,7 @@ - + @@ -27,9 +27,7 @@ This file belongs into ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/ - $Id: faq.sgml,v 2.106 2014/12/19 12:31:28 fabiankeil Exp $ - - Copyright (C) 2001-2014 Privoxy Developers http://www.privoxy.org/ + Copyright (C) 2001-2018 Privoxy Developers https://www.privoxy.org/ See LICENSE. Based partially on the Internet Junkbuster FAQ originally written by and @@ -73,12 +71,12 @@ - Copyright &my-copy; 2001-2014 by - Privoxy Developers + Copyright &my-copy; 2001-2018 by + Privoxy Developers -$Id: faq.sgml,v 2.106 2014/12/19 12:31:28 fabiankeil Exp $ +$Id: faq.sgml,v 2.135 2017/03/27 10:22:27 fabiankeil Exp $ - - @@ -236,8 +231,8 @@ Privoxy work? - -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? Though outdated, Junkbusters Corporation continued to offer their original @@ -289,8 +284,7 @@ from the old Junkbuster? -How does Privoxy know what is -an ad, and what is not? +How does Privoxy know what is an ad, and what is not? Privoxy's approach to blocking ads is twofold: @@ -318,8 +312,8 @@ an ad, and what is not? - -Can Privoxy make mistakes? +<sect2 renderas="sect3" id="mistakes"> +<title>Can Privoxy make mistakes? This does not sound very scientific. Actually, it's a black art ;-) And yes, it is always possible to have a broad @@ -338,8 +332,8 @@ This does not sound very scientific. - -Will I have to configure Privoxy +<sect2 renderas="sect3" id="configornot"> +<title>Will I have to configure Privoxy before I can use it? That depends on your expectations. @@ -463,9 +457,9 @@ warranty? Registration? -I would like to help you, what can I do? +I would like to help you, what can I do? -Would you like to participate? +Would you like to participate? Well, we always need help. There is something for everybody who wants to help us. We welcome new developers, packagers, @@ -479,8 +473,8 @@ warranty? Registration? So first thing, subscribe to the Privoxy Users - or the Privoxy + url="https://lists.privoxy.org/mailman/listinfo/privoxy-users">Privoxy Users + or the Privoxy Developers mailing list, join the discussion, help out other users, provide general feedback or report problems you noticed. @@ -504,7 +498,7 @@ warranty? Registration? + + @@ -696,9 +750,9 @@ All the ads are there. What's wrong? Privoxy is not running at all. Check the log file. For instructions on starting Privoxy and browser configuration, - see the chapter + see the chapter on starting Privoxy in the - User Manual. + User Manual. @@ -711,9 +765,9 @@ Privoxy is running and being used. First, make sure that Privoxy is really running and being used by visiting http://p.p/. You should see the Privoxy main page. If not, see - the chapter + the chapter on starting Privoxy in the - User Manual. + User Manual. @@ -746,8 +800,8 @@ Privoxy is running and being used. Configuration - -What exactly is an <quote>actions</quote> file? + +What exactly is an <quote>actions</quote> file? &my-app; utilizes the concept of @@ -791,8 +845,8 @@ some of these actions. - -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? @@ -825,15 +879,15 @@ the differences? Based on your feedback and the continuing development, updates of default.action will be made available from time to time on the files section of - our project page. + url="https://sourceforge.net/project/showfiles.php?group_id=11118">files section of + our project page. If you wish to receive an email notification whenever we release updates of Privoxy or the actions file, subscribe - to our announce mailing list, ijbswa-announce@lists.sourceforge.net. + url="https://lists.privoxy.org/mailman/listinfo/privoxy-announce">subscribe + to our announce mailing list, privoxy-announce@lists.privoxy.org. @@ -977,8 +1031,8 @@ with a browser? Does that not raise security issues? - -What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>? + +What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>? The default.filter file is where filters as supplied by the developers are defined. @@ -1031,7 +1085,7 @@ with a browser? Does that not raise security issues? If you intend to develop your own filters, you might want to have a look at Privoxy-Filter-Test. + url="https://www.fabiankeil.de/sourcecode/pft/">Privoxy-Filter-Test. @@ -1096,8 +1150,8 @@ with a browser? Does that not raise security issues? - -Instead of ads, now I get a checkerboard pattern. I don't want to see anything. + +Instead of ads, now I get a checkerboard pattern. I don't want to see anything. The replacement for blocked images can be controlled with the set-image-blocker @@ -1119,8 +1173,8 @@ with a browser? Does that not raise security issues? - -Why would anybody want to see a checkerboard pattern? + +Why would anybody want to see a checkerboard pattern? Remember that telling which image is an ad and which isn't, is an educated guess. While we hope that the standard configuration @@ -1134,8 +1188,8 @@ with a browser? Does that not raise security issues? - -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? This happens when the banners are not embedded in the HTML code of the @@ -1174,7 +1228,7 @@ on Win2K/NT/XP? Earlier ]]>3.x versions could run as a system service using srvany.exe. See the discussion at http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118, + 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, for details, and a sample configuration. @@ -1280,7 +1334,7 @@ and thus avoid individual browser configuration? For a good discussion of some of the issues involved (including privacy and security issues), see - http://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. @@ -1524,8 +1578,8 @@ the BLOCKED page? Miscellaneous - -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. How much of an impact depends on many things, including the CPU of the host @@ -1615,6 +1669,13 @@ delays in page requests. What's wrong? hence it could not be intercepted, and you have accessed the real web site at config.privoxy.org. + + 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). + @@ -1698,8 +1759,8 @@ us help you. Your efforts are not wasted, and we do appreciate them. - -Can Privoxy guarantee I am anonymous? + +Can Privoxy guarantee I am anonymous? No. Your chances of remaining anonymous are improved, but unless you chain Privoxy with Tor @@ -1742,8 +1803,8 @@ us help you. Your efforts are not wasted, and we do appreciate them. - -A test site says I am not using a Proxy. + +A test site says I am not using a Proxy. Good! Actually, they are probably testing for some other kinds of proxies. Hiding yourself completely would require additional steps. @@ -1855,8 +1916,8 @@ us help you. Your efforts are not wasted, and we do appreciate them. - -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? @@ -1905,8 +1966,8 @@ content is being altered? - -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? No, it does not have this ability at all. You want something like @@ -1920,8 +1981,8 @@ speed up web browsing? - -What about as a firewall? Can Privoxy protect me? + +What about as a firewall? Can Privoxy protect me? Not in the way you mean, or in the way some firewall vendors claim they can. Privoxy can help protect your privacy, but can't @@ -1930,8 +1991,8 @@ speed up web browsing? - -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? It is technically possible to eliminate banners and ads in a way that frees @@ -1959,8 +2020,8 @@ ads used to be. Why? - -How can Privoxy filter Secure (HTTPS) URLs? + +How can Privoxy filter Secure (HTTPS) URLs? Since secure HTTP connections are encrypted SSL sessions between your browser and the secure site, and are meant to be reliably secure, @@ -1991,8 +2052,22 @@ ads used to be. Why? - -Privoxy runs as a <quote>server</quote>. How +<sect2 renderas="sect3" id="http2"> +<title>Does Privoxy support HTTP/2? + + Privoxy currently doesn't parse HTTP/2 but applications + can tunnel HTTP/2 through Privoxy if Privoxy is configured + to allow CONNECT requests (default) which are also used + for HTTPS. + + + Adding HTTP/2 support is on the TODO list but currently + nobody is known to work on it. + + + + +Privoxy runs as a <quote>server</quote>. How secure is it? Do I need to take any special precautions? On Unix-like systems, Privoxy can run as a non-privileged @@ -2063,7 +2138,7 @@ out of the picture? My logs show Privoxy <quote>crunches</quote> ads, but also its own internal CGI pages. What is a <quote>crunch</quote>? - A crunch simply means Privoxy intercepted + A crunch means Privoxy intercepted something, nothing more. Often this is indeed ads or banners, but Privoxy uses the same mechanism for trapping requests for its own internal pages. For instance, a request for @@ -2080,7 +2155,7 @@ ads, but also its own internal CGI pages. What is a crunch? -Can Privoxy effect files that I download +<title>Can Privoxy affect files that I download from a webserver? FTP server? From the webserver's perspective, there is no difference between @@ -2233,11 +2308,11 @@ and related issues? 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 ASUS Netbooks. + 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. Privoxy's license allows vendor @@ -2264,8 +2339,8 @@ and related issues? Troubleshooting - -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? There are several possibilities: @@ -2306,8 +2381,8 @@ and related issues? - -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? If the ad had been displayed before you added its URL, it will probably be @@ -2389,8 +2464,8 @@ Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua - -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? @@ -2460,7 +2535,7 @@ What can I do? every time I start IE. What gives? - This is a quirk that effects the installation of + This is a quirk that affects the installation of Privoxy, in conjunction with Internet Explorer and Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may appear to be corrupted or invalid DUN settings, or passwords. @@ -2606,37 +2681,6 @@ every time I start IE. What gives? - - - -I get a completely blank page at one site. <quote>View Source</quote> - shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without - Privoxy the page loads fine. - - Chances are that the site suffers from a bug in - PHP, - which results in empty pages being sent if the client explicitly requests - an uncompressed page, like Privoxy does. - This bug has been fixed in PHP 4.2.3. - - - To find out if this is in fact the source of the problem, try adding - the site to a -prevent-compression section in - user.action: - - - # Make exceptions for ill-behaved sites: - # - {-prevent-compression} - .example.com - - If that works, you may also want to report the problem to the - site's webmasters, telling them to use zlib.output_compression - instead of ob_gzhandler in their PHP applications (workaround) - or upgrade to PHP 4.2.3 or later (fix). - - - My logs show many <quote>Unable to get my own hostname</quote> lines. Why? @@ -2702,7 +2746,7 @@ Why? Upgrading Privoxy, or going to the most recent default.action file available from SourceForge + url="https://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge might be worth a try, too. @@ -2940,6 +2984,63 @@ browsing has slowed to a crawl. What gives? + +What are tainted sockets and how do I prevent them? + + &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). + + + 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). + + + 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. + + + These are just two examples, there are currently a bit more than + 25 scenarios in which a socket is considered tainted. + + + 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. + + + + +After adding my custom filters, &my-app; crashes when visitting certain websites + + 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. + + + Unless the problem occurs with the filters available in the default configuration, + this is not considered a Privoxy bug. + + + 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 + pcrestack man page + and the documentation of your operating system. + +