+ Some systems allow IPv4 clients to connect to IPv6 server sockets.
+ Then the client's IPv4 address will be translated by the system into
+ IPv6 address space with special prefix ::ffff:0:0/96 (so called IPv4
+ mapped IPv6 address). <application>Privoxy</application> can handle it
+ and maps such ACL addresses automatically.
+ </para>
+ <para>
+ Denying access to particular sites by ACL may have undesired side effects
+ if the site in question is hosted on a machine which also hosts other sites
+ (most sites are).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ Explicitly define the default behavior if no ACL and
+ <literal>listen-address</literal> are set: <quote>localhost</quote>
+ is OK. The absence of a <replaceable class="parameter">dst_addr</replaceable> implies that
+ <emphasis>all</emphasis> destination addresses are OK:
+ </para>
+ <para>
+ <screen>
+ permit-access localhost
+</screen>
+ </para>
+ <para>
+ Allow any host on the same class C subnet as www.privoxy.org access to
+ nothing but www.example.com (or other domains hosted on the same system):
+ </para>
+ <para>
+ <screen>
+ permit-access www.privoxy.org/24 www.example.com/32
+</screen>
+ </para>
+ <para>
+ Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
+ with the exception that 192.168.45.73 may not access the IP address behind
+ www.dirty-stuff.example.com:
+ </para>
+ <para>
+ <screen>
+ permit-access 192.168.45.64/26
+ deny-access 192.168.45.73 www.dirty-stuff.example.com
+</screen>
+ </para>
+ <para>
+ Allow access from the IPv4 network 192.0.2.0/24 even if listening on
+ an IPv6 wild card address (not supported on all platforms):
+ </para>
+ <para>
+ <programlisting>
+ permit-access 192.0.2.0/24
+</programlisting>
+ </para>
+ <para>
+ This is equivalent to the following line even if listening on an
+ IPv4 address (not supported on all platforms):
+ </para>
+ <para>
+ <programlisting>
+ permit-access [::ffff:192.0.2.0]/120
+</programlisting>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
+
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="buffer-limit"><title>buffer-limit</title>
+
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Maximum size of the buffer for content filtering.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>Size in Kbytes</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>4096</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Use a 4MB (4096 KB) limit.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ For content filtering, i.e. the <literal>+filter</literal> and
+ <literal>+deanimate-gif</literal> actions, it is necessary that
+ <application>Privoxy</application> buffers the entire document body.
+ This can be potentially dangerous, since a server could just keep sending
+ data indefinitely and wait for your RAM to exhaust -- with nasty consequences.
+ Hence this option.
+ </para>
+ <para>
+ When a document buffer size reaches the <literal>buffer-limit</literal>, it is
+ flushed to the client unfiltered and no further attempt to
+ filter the rest of the document is made. Remember that there may be multiple threads
+ running, which might require up to <literal>buffer-limit</literal> Kbytes
+ <emphasis>each</emphasis>, unless you have enabled <quote>single-threaded</quote>
+ above.
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+
+<![%config-file;[<literallayout>@@buffer-limit 4096</literallayout>]]>
+</sect3>
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="enable-proxy-authentication-forwarding"><title>enable-proxy-authentication-forwarding</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether or not proxy authentication through &my-app; should work.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>0 or 1</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>0</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Proxy authentication headers are removed.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Privoxy itself does not support proxy authentication, but can
+ allow clients to authenticate against Privoxy's parent proxy.
+ </para>
+ <para>
+ By default Privoxy (3.0.21 and later) don't do that and remove
+ Proxy-Authorization headers in requests and Proxy-Authenticate
+ headers in responses to make it harder for malicious sites to
+ trick inexperienced users into providing login information.
+ </para>
+ <para>
+ If this option is enabled the headers are forwarded.
+ </para>
+ <para>
+ Enabling this option is <emphasis>not recommended</emphasis> if there is
+ no parent proxy that requires authentication or if the local network between
+ Privoxy and the parent proxy isn't trustworthy. If proxy authentication is
+ only required for some requests, it is recommended to use a client header filter
+ to remove the authentication headers for requests where they aren't needed.
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+
+<![%config-file;[<literallayout>@@enable-proxy-authentication-forwarding 0</literallayout>]]>
+</sect3>
+
+</sect2>
+
+<!-- ~ End section ~ -->
+
+
+<!-- ~~~~~ New section ~~~~~ -->
+
+<sect2 id="forwarding">
+<title>Forwarding</title>
+
+<para>
+ This feature allows routing of HTTP requests through a chain of
+ multiple proxies.
+</para>
+<para>
+ Forwarding can be used to chain Privoxy with a caching proxy to speed
+ up browsing. Using a parent proxy may also be necessary if the machine
+ that <application>Privoxy</application> runs on has no direct Internet access.
+</para>
+<para>
+ Note that parent proxies can severely decrease your privacy level.
+ For example a parent proxy could add your IP address to the request
+ headers and if it's a caching proxy it may add the <quote>Etag</quote>
+ header to revalidation requests again, even though you configured Privoxy
+ to remove it. It may also ignore Privoxy's header time randomization and use the
+ original values which could be used by the server as cookie replacement
+ to track your steps between visits.
+</para>
+
+<para>
+ Also specified here are SOCKS proxies. <application>Privoxy</application>
+ supports the SOCKS 4 and SOCKS 4A protocols.
+</para>
+
+<sect3 renderas="sect4" id="forward"><title>forward</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ To which parent HTTP proxy specific requests should be routed.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable class="parameter">target_pattern</replaceable>
+ <replaceable class="parameter">http_parent</replaceable>[:<replaceable class="parameter">port</replaceable>]
+ </para>
+ <para>
+ where <replaceable class="parameter">target_pattern</replaceable> is a <link linkend="af-patterns">URL pattern</link>
+ that specifies to which requests (i.e. URLs) this forward rule shall apply. Use <literal>/</literal> to
+ denote <quote>all URLs</quote>.
+ <replaceable class="parameter">http_parent</replaceable>[:<replaceable class="parameter">port</replaceable>]
+ is the DNS name or IP address of the parent HTTP proxy through which the requests should be forwarded,
+ optionally followed by its listening port (default: 8000).
+ Use a single dot (<literal>.</literal>) to denote <quote>no forwarding</quote>.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para><emphasis>Unset</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Don't use parent HTTP proxies.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
+ forwarded to another HTTP proxy but are made directly to the web servers.
+ </para>
+ <para>
+ <replaceable class="parameter">http_parent</replaceable> can be a
+ numerical IPv6 address (if
+ <ulink url="http://tools.ietf.org/html/rfc3493">RFC 3493</ulink> is
+ implemented). To prevent clashes with the port delimiter, the whole IP
+ address has to be put into brackets. On the other hand a <replaceable
+ class="parameter">target_pattern</replaceable> containing an IPv6 address
+ has to be put into angle brackets (normal brackets are reserved for
+ regular expressions already).
+ </para>
+ <para>
+ Multiple lines are OK, they are checked in sequence, and the last match wins.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ Everything goes to an example parent proxy, except SSL on port 443 (which it doesn't handle):
+ </para>
+ <para>
+ <screen>
+ forward / parent-proxy.example.org:8080
+ forward :443 .
+</screen>
+ </para>
+ <para>
+ Everything goes to our example ISP's caching proxy, except for requests
+ to that ISP's sites:
+ </para>
+ <para>
+ <screen>
+ forward / caching-proxy.isp.example.net:8000
+ forward .isp.example.net .
+</screen>
+ </para>
+ <para>
+ Parent proxy specified by an IPv6 address:
+ </para>
+ <para>
+ <programlisting>
+ forward / [2001:DB8::1]:8000
+</programlisting>
+ </para>
+ <para>
+ Suppose your parent proxy doesn't support IPv6:
+ </para>
+ <para>
+ <programlisting>
+ forward / parent-proxy.example.org:8000
+ forward ipv6-server.example.org .
+ forward <[2-3][0-9a-f][0-9a-f][0-9a-f]:*> .
+</programlisting>
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
+
+
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="socks"><title>
+forward-socks4, forward-socks4a, forward-socks5 and forward-socks5t</title>
+<anchor id="forward-socks4">
+<anchor id="forward-socks4a">
+
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Through which SOCKS proxy (and optionally to which parent HTTP proxy) specific requests should be routed.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable class="parameter">target_pattern</replaceable>
+ <replaceable class="parameter">socks_proxy</replaceable>[:<replaceable class="parameter">port</replaceable>]
+ <replaceable class="parameter">http_parent</replaceable>[:<replaceable class="parameter">port</replaceable>]
+ </para>
+ <para>
+ where <replaceable class="parameter">target_pattern</replaceable> is a
+ <link linkend="af-patterns">URL pattern</link> that specifies to which
+ requests (i.e. URLs) this forward rule shall apply. Use <literal>/</literal> to
+ denote <quote>all URLs</quote>. <replaceable class="parameter">http_parent</replaceable>
+ and <replaceable class="parameter">socks_proxy</replaceable>
+ are IP addresses in dotted decimal notation or valid DNS names
+ (<replaceable class="parameter">http_parent</replaceable>
+ may be <quote>.</quote> to denote <quote>no HTTP forwarding</quote>), and the optional
+ <replaceable class="parameter">port</replaceable> parameters are TCP ports,
+ i.e. integer values from 1 to 65535
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para><emphasis>Unset</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Don't use SOCKS proxies.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Multiple lines are OK, they are checked in sequence, and the last match wins.
+ </para>
+ <para>
+ The difference between <literal>forward-socks4</literal> and <literal>forward-socks4a</literal>
+ is that in the SOCKS 4A protocol, the DNS resolution of the target hostname happens on the SOCKS
+ server, while in SOCKS 4 it happens locally.
+ </para>
+ <para>
+ With <literal>forward-socks5</literal> the DNS resolution will happen on the remote server as well.
+ </para>
+ <para>
+ <literal>forward-socks5t</literal> works like vanilla <literal>forward-socks5</literal> but
+ lets &my-app; additionally use Tor-specific SOCKS extensions. Currently the only supported
+ SOCKS extension is optimistic data which can reduce the latency for the first request made
+ on a newly created connection.
+ </para>
+ <para>
+ <replaceable class="parameter">socks_proxy</replaceable> and
+ <replaceable class="parameter">http_parent</replaceable> can be a
+ numerical IPv6 address (if
+ <ulink url="http://tools.ietf.org/html/rfc3493">RFC 3493</ulink> is
+ implemented). To prevent clashes with the port delimiter, the whole IP
+ address has to be put into brackets. On the other hand a <replaceable
+ class="parameter">target_pattern</replaceable> containing an IPv6 address
+ has to be put into angle brackets (normal brackets are reserved for
+ regular expressions already).
+ </para>
+ <para>
+ If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
+ forwarded to another HTTP proxy but are made (HTTP-wise) directly to the web servers, albeit through
+ a SOCKS proxy.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ From the company example.com, direct connections are made to all
+ <quote>internal</quote> domains, but everything outbound goes through
+ their ISP's proxy by way of example.com's corporate SOCKS 4A gateway to
+ the Internet.
+ </para>
+ <para>
+ <screen>
+ forward-socks4a / socks-gw.example.com:1080 www-cache.isp.example.net:8080
+ forward .example.com .
+</screen>
+ </para>
+ <para>
+ A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this:
+ </para>
+ <para>
+ <screen>
+ forward-socks4 / socks-gw.example.com:1080 .
+</screen>
+ </para>
+
+ <para>
+ To chain Privoxy and Tor, both running on the same system, you would use
+ something like:
+ </para>
+ <para>
+ <screen>
+ forward-socks5 / 127.0.0.1:9050 .
+</screen>
+ </para>
+
+ <para>
+ The public <application>Tor</application> network can't be used to
+ reach your local network, if you need to access local servers you
+ therefore might want to make some exceptions:
+ </para>
+ <para>
+ <screen>
+ forward 192.168.*.*/ .
+ forward 10.*.*.*/ .
+ forward 127.*.*.*/ .
+</screen>
+ </para>
+ <para>
+ Unencrypted connections to systems in these address ranges will
+ be as (un)secure as the local network is, but the alternative is that you
+ can't reach the local network through <application>Privoxy</application>
+ at all. Of course this may actually be desired and there is no reason
+ to make these exceptions if you aren't sure you need them.
+ </para>
+ <para>
+ If you also want to be able to reach servers in your local network by
+ using their names, you will need additional exceptions that look like
+ this:
+ </para>
+ <para>
+ <screen>
+ forward localhost/ .
+</screen>
+ </para>
+
+ </listitem>
+ </varlistentry>
+</variablelist>
+</sect3>
+
+<![%user-man;[ <!-- not included in config due to length -->
+<!-- ~~~~~ New section ~~~~~ -->
+<sect3 renderas="sect4" id="advanced-forwarding-examples"><title>Advanced Forwarding Examples</title>
+
+<para>
+ If you have links to multiple ISPs that provide various special content
+ only to their subscribers, you can configure multiple <application>Privoxies</application>
+ which have connections to the respective ISPs to act as forwarders to each other, so that
+ <emphasis>your</emphasis> users can see the internal content of all ISPs.
+</para>
+
+<para>
+ Assume that host-a has a PPP connection to isp-a.example.net. And host-b has a PPP connection to
+ isp-b.example.org. Both run <application>Privoxy</application>. Their forwarding
+ configuration can look like this:
+</para>
+
+<para>
+ host-a:
+</para>
+
+<para>
+ <screen>
+ forward / .
+ forward .isp-b.example.net host-b:8118
+</screen>
+</para>
+
+<para>
+ host-b:
+</para>
+
+<para>
+ <screen>
+ forward / .
+ forward .isp-a.example.org host-a:8118
+</screen>
+</para>
+
+<para>
+ Now, your users can set their browser's proxy to use either
+ host-a or host-b and be able to browse the internal content
+ of both isp-a and isp-b.
+</para>
+
+<para>
+ If you intend to chain <application>Privoxy</application> and
+ <application>squid</application> locally, then chaining as
+ <literal>browser -> squid -> privoxy</literal> is the recommended way.
+</para>
+
+<para>
+ Assuming that <application>Privoxy</application> and <application>squid</application>
+ run on the same box, your <application>squid</application> configuration could then look like this:
+</para>
+
+<para>
+ <screen>
+ # Define Privoxy as parent proxy (without ICP)
+ cache_peer 127.0.0.1 parent 8118 7 no-query
+
+ # Define ACL for protocol FTP
+ acl ftp proto FTP
+
+ # Do not forward FTP requests to Privoxy
+ always_direct allow ftp
+
+ # Forward all the rest to Privoxy
+ never_direct allow all</screen>
+</para>
+
+<para>
+ You would then need to change your browser's proxy settings to <application>squid</application>'s address and port.
+ Squid normally uses port 3128. If unsure consult <literal>http_port</literal> in <filename>squid.conf</filename>.
+</para>
+
+<para>
+ You could just as well decide to only forward requests you suspect
+ of leading to Windows executables through a virus-scanning parent proxy,
+ say, on <literal>antivir.example.com</literal>, port 8010:
+</para>
+
+<para>
+ <screen>
+ forward / .
+ forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010</screen>
+</para>
+
+</sect3>
+]]>
+
+<sect3 renderas="sect4" id="forwarded-connect-retries"><title>forwarded-connect-retries</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ How often Privoxy retries if a forwarded connection request fails.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable class="parameter">Number of retries.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para><emphasis>0</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Connections forwarded through other proxies are treated like direct connections and no retry attempts are made.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ <replaceable class="parameter">forwarded-connect-retries</replaceable> is mainly interesting
+ for socks4a connections, where <application>Privoxy</application> can't detect why the connections failed.
+ The connection might have failed because of a DNS timeout in which case a retry makes sense,
+ but it might also have failed because the server doesn't exist or isn't reachable. In this
+ case the retry will just delay the appearance of Privoxy's error message.
+ </para>
+ <para>
+ Note that in the context of this option, <quote>forwarded connections</quote> includes all connections
+ that Privoxy forwards through other proxies. This option is not limited to the HTTP CONNECT method.
+ </para>
+ <para>
+ Only use this option, if you are getting lots of forwarding-related error messages
+ that go away when you try again manually. Start with a small value and check Privoxy's
+ logfile from time to time, to see how many retries are usually needed.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ forwarded-connect-retries 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@forwarded-connect-retries 0</literallayout>]]>
+</sect3>
+
+</sect2>
+
+<sect2 id="misc">
+<title>Miscellaneous</title>
+
+<sect3 renderas="sect4" id="accept-intercepted-requests"><title>accept-intercepted-requests</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether intercepted requests should be treated as valid.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>0 or 1</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para><emphasis>0</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Only proxy requests are accepted, intercepted requests are treated as invalid.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ If you don't trust your clients and want to force them
+ to use <application>Privoxy</application>, enable this
+ option and configure your packet filter to redirect outgoing
+ HTTP connections into <application>Privoxy</application>.
+ </para>
+ <para>
+ Make sure that <application>Privoxy's</application> own requests
+ aren't redirected as well. Additionally take care that
+ <application>Privoxy</application> can't intentionally connect
+ to itself, otherwise you could run into redirection loops if
+ <application>Privoxy's</application> listening port is reachable
+ by the outside or an attacker has access to the pages you visit.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ accept-intercepted-requests 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@accept-intercepted-requests 0</literallayout>]]>
+</sect3>
+
+<sect3 renderas="sect4" id="allow-cgi-request-crunching"><title>allow-cgi-request-crunching</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether requests to <application>Privoxy's</application> CGI pages can be blocked or redirected.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>0 or 1</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para><emphasis>0</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ <application>Privoxy</application> ignores block and redirect actions for its CGI pages.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ By default <application>Privoxy</application> ignores block or redirect actions
+ for its CGI pages. Intercepting these requests can be useful in multi-user
+ setups to implement fine-grained access control, but it can also render the complete
+ web interface useless and make debugging problems painful if done without care.
+ </para>
+ <para>
+ Don't enable this option unless you're sure that you really need it.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ allow-cgi-request-crunching 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@allow-cgi-request-crunching 0</literallayout>]]>
+</sect3>
+
+<sect3 renderas="sect4" id="split-large-forms"><title>split-large-forms</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether the CGI interface should stay compatible with broken HTTP clients.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>0 or 1</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para><emphasis>0</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ The CGI form generate long GET URLs.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ <application>Privoxy's</application> CGI forms can lead to
+ rather long URLs. This isn't a problem as far as the HTTP
+ standard is concerned, but it can confuse clients with arbitrary
+ URL length limitations.
+ </para>
+ <para>
+ Enabling split-large-forms causes <application>Privoxy</application>
+ to divide big forms into smaller ones to keep the URL length down.
+ It makes editing a lot less convenient and you can no longer
+ submit all changes at once, but at least it works around this
+ browser bug.
+ </para>
+ <para>
+ If you don't notice any editing problems, there is no reason
+ to enable this option, but if one of the submit buttons appears
+ to be broken, you should give it a try.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ split-large-forms 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@split-large-forms 0</literallayout>]]>
+</sect3>
+
+<sect3 renderas="sect4" id="keep-alive-timeout"><title>keep-alive-timeout</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Number of seconds after which an open connection will no longer be reused.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>Time in seconds.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>None</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Connections are not kept alive.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ This option allows clients to keep the connection to &my-app;
+ alive. If the server supports it, &my-app; will keep
+ the connection to the server alive as well. Under certain
+ circumstances this may result in speed-ups.
+ </para>
+ <para>
+ By default, &my-app; will close the connection to the server if
+ the client connection gets closed, or if the specified timeout
+ has been reached without a new request coming in. This behaviour
+ can be changed with the <ulink
+ url="#CONNECTION-SHARING">connection-sharing</ulink> option.
+ </para>
+ <para>
+ This option has no effect if <application>Privoxy</application>
+ has been compiled without keep-alive support.
+ </para>
+ <para>
+ Note that a timeout of five seconds as used in the default
+ configuration file significantly decreases the number of
+ connections that will be reused. The value is used because
+ some browsers limit the number of connections they open to
+ a single host and apply the same limit to proxies. This can
+ result in a single website <quote>grabbing</quote> all the
+ connections the browser allows, which means connections to
+ other websites can't be opened until the connections currently
+ in use time out.
+ </para>
+ <para>
+ Several users have reported this as a Privoxy bug, so the
+ default value has been reduced. Consider increasing it to
+ 300 seconds or even more if you think your browser can handle
+ it. If your browser appears to be hanging, it probably can't.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ keep-alive-timeout 300
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@keep-alive-timeout 5</literallayout>]]>
+</sect3>
+
+
+<sect3 renderas="sect4" id="tolerate-pipelining"><title>tolerate-pipelining</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether or not pipelined requests should be served.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>0 or 1.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>None</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ If Privoxy receives more than one request at once, it terminates the
+ client connection after serving the first one.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ &my-app; currently doesn't pipeline outgoing requests,
+ thus allowing pipelining on the client connection is not
+ guaranteed to improve the performance.
+ </para>
+ <para>
+ By default &my-app; tries to discourage clients from pipelining
+ by discarding aggressively pipelined requests, which forces the
+ client to resend them through a new connection.
+ </para>
+ <para>
+ This option lets &my-app; tolerate pipelining. Whether or not
+ that improves performance mainly depends on the client configuration.
+ </para>
+ <para>
+ If you are seeing problems with pages not properly loading,
+ disabling this option could work around the problem.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ tolerate-pipelining 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@tolerate-pipelining 1</literallayout>]]>
+</sect3>
+
+
+<sect3 renderas="sect4" id="default-server-timeout"><title>default-server-timeout</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Assumed server-side keep-alive timeout if not specified by the server.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>Time in seconds.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>None</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Connections for which the server didn't specify the keep-alive
+ timeout are not reused.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Enabling this option significantly increases the number of connections
+ that are reused, provided the <ulink
+ url="#KEEP-ALIVE-TIMEOUT">keep-alive-timeout</ulink> option
+ is also enabled.
+ </para>
+ <para>
+ While it also increases the number of connections problems
+ when &my-app; tries to reuse a connection that already has
+ been closed on the server side, or is closed while &my-app;
+ is trying to reuse it, this should only be a problem if it
+ happens for the first request sent by the client. If it happens
+ for requests on reused client connections, &my-app; will simply
+ close the connection and the client is supposed to retry the
+ request without bothering the user.
+ </para>
+ <para>
+ Enabling this option is therefore only recommended if the
+ <ulink
+ url="#CONNECTION-SHARING">connection-sharing</ulink> option
+ is disabled.
+ </para>
+ <para>
+ It is an error to specify a value larger than the <ulink
+ url="#KEEP-ALIVE-TIMEOUT">keep-alive-timeout</ulink> value.
+ </para>
+ <para>
+ This option has no effect if <application>Privoxy</application>
+ has been compiled without keep-alive support.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ default-server-timeout 60
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@#default-server-timeout 60</literallayout>]]>
+</sect3>
+
+
+<sect3 renderas="sect4" id="connection-sharing"><title>connection-sharing</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Whether or not outgoing connections that have been kept alive
+ should be shared between different incoming connections.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>0 or 1</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>None</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Connections are not shared.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ This option has no effect if <application>Privoxy</application>
+ has been compiled without keep-alive support, or if it's disabled.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ Note that reusing connections doesn't necessary cause speedups.
+ There are also a few privacy implications you should be aware of.
+ </para>
+ <para>
+ If this option is effective, outgoing connections are shared between
+ clients (if there are more than one) and closing the browser that initiated
+ the outgoing connection does no longer affect the connection between &my-app;
+ and the server unless the client's request hasn't been completed yet.
+ </para>
+ <para>
+ If the outgoing connection is idle, it will not be closed until either
+ <application>Privoxy's</application> or the server's timeout is reached.
+ While it's open, the server knows that the system running &my-app; is still
+ there.
+ </para>
+ <para>
+ If there are more than one client (maybe even belonging to multiple users),
+ they will be able to reuse each others connections. This is potentially
+ dangerous in case of authentication schemes like NTLM where only the
+ connection is authenticated, instead of requiring authentication for
+ each request.
+ </para>
+ <para>
+ If there is only a single client, and if said client can keep connections
+ alive on its own, enabling this option has next to no effect. If the client
+ doesn't support connection keep-alive, enabling this option may make sense
+ as it allows &my-app; to keep outgoing connections alive even if the client
+ itself doesn't support it.
+ </para>
+ <para>
+ You should also be aware that enabling this option increases the likelihood
+ of getting the "No server or forwarder data" error message, especially if you
+ are using a slow connection to the Internet.
+ </para>
+ <para>
+ This option should only be used by experienced users who
+ understand the risks and can weight them against the benefits.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ connection-sharing 1
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@#connection-sharing 1</literallayout>]]>
+</sect3>
+
+
+<sect3 renderas="sect4" id="socket-timeout"><title>socket-timeout</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Number of seconds after which a socket times out if
+ no data is received.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>Time in seconds.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>None</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ A default value of 300 seconds is used.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Notes:</term>
+ <listitem>
+ <para>
+ The default is quite high and you probably want to reduce it.
+ If you aren't using an occasionally slow proxy like Tor, reducing
+ it to a few seconds should be fine.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Examples:</term>
+ <listitem>
+ <para>
+ socket-timeout 300
+ </para>
+ </listitem>
+ </varlistentry>
+</variablelist>
+<![%config-file;[<literallayout>@@socket-timeout 300</literallayout>]]>
+</sect3>
+
+
+<sect3 renderas="sect4" id="max-client-connections"><title>max-client-connections</title>
+<variablelist>
+ <varlistentry>
+ <term>Specifies:</term>
+ <listitem>
+ <para>
+ Maximum number of client connections that will be served.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Type of value:</term>
+ <listitem>
+ <para>
+ <replaceable>Positive number.</replaceable>
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Default value:</term>
+ <listitem>
+ <para>128</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Effect if unset:</term>
+ <listitem>
+ <para>
+ Connections are served until a resource limit is reached.