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CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
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-TITLE="Privoxy 3.0.13 User Manual"
+TITLE="Privoxy 3.0.17 User Manual"
HREF="index.html"><LINK
REL="PREVIOUS"
TITLE="Privoxy Configuration"
><TH
COLSPAN="3"
ALIGN="center"
->Privoxy 3.0.13 User Manual</TH
+>Privoxy 3.0.17 User Manual</TH
></TR
><TR
><TD
>Privoxy</SPAN
>'s
operation that are not location dependent (i.e. they apply universally, no matter
- where you may be surfing).</P
+ where you may be surfing). Like the filter and action files, the config file is
+ a plain text file and can be modified with a text editor like emacs, vim or
+ notepad.exe.</P
><DIV
CLASS="SECT2"
><H2
debug 2 # show each connection status
debug 4 # show I/O status
debug 8 # show header parsing
- debug 16 # log all data written to the network into the logfile
+ debug 16 # log all data written to the network
debug 32 # debug force feature
debug 64 # debug regular expression filters
debug 128 # debug redirects
> didn't let through, and the reason why.
debug 2048 # CGI user interface
debug 4096 # Startup banner and warnings.
- debug 8192 # Non-fatal errors</PRE
+ debug 8192 # Non-fatal errors
+ debug 32768 # log all data read from the network</PRE
></TD
></TR
></TABLE
HREF="config.html#ACLS"
>access control lists</A
> (ACL's, see below), and/or
- a firewall. If the hostname is localhost, <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- will explicitly try to bind to an IPv4 address. For other hostnames it depends
- on the operating system which IP version will be used.
+ a firewall.
</P
><P
> If you open <SPAN
IP addresses, only the first one is used.
</P
><P
-> Some systems allows IPv4 client to connect to IPv6 server socket.
- Then the client's IPv4 address will be translated by system into
+> 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). <SPAN
CLASS="APPLICATION"
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.
</P
+><P
+> Due to a bug, this option currently also causes Privoxy to
+ retry in case of certain problems with direct connections.
+ </P
></DD
><DT
>Examples:</DT
></DL
></DIV
></DIV
+></DIV
+><DIV
+CLASS="SECT2"
+><H2
+CLASS="SECT2"
+><A
+NAME="MISC"
+>7.6. Miscellaneous</A
+></H2
><DIV
CLASS="SECT3"
><H4
CLASS="SECT3"
><A
NAME="ACCEPT-INTERCEPTED-REQUESTS"
->7.5.5. accept-intercepted-requests</A
+>7.6.1. accept-intercepted-requests</A
></H4
><P
></P
CLASS="SECT3"
><A
NAME="ALLOW-CGI-REQUEST-CRUNCHING"
->7.5.6. allow-cgi-request-crunching</A
+>7.6.2. allow-cgi-request-crunching</A
></H4
><P
></P
CLASS="SECT3"
><A
NAME="SPLIT-LARGE-FORMS"
->7.5.7. split-large-forms</A
+>7.6.3. split-large-forms</A
></H4
><P
></P
CLASS="SECT3"
><A
NAME="KEEP-ALIVE-TIMEOUT"
->7.5.8. keep-alive-timeout</A
+>7.6.4. keep-alive-timeout</A
></H4
><P
></P
>Effect if unset:</DT
><DD
><P
-> Connections are not reused.
+> Connections are not kept alive.
+ </P
+></DD
+><DT
+>Notes:</DT
+><DD
+><P
+> This option allows clients to keep the connection to <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+>
+ alive. If the server supports it, <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> will keep
+ the connection to the server alive as well. Under certain
+ circumstances this may result in speed-ups.
+ </P
+><P
+> By default, <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> 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 <A
+HREF="#CONNECTION-SHARING"
+TARGET="_top"
+>connection-sharing</A
+> option.
+ </P
+><P
+> This option has no effect if <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+>
+ has been compiled without keep-alive support.
+ </P
+><P
+> 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 <SPAN
+CLASS="QUOTE"
+>"grabbing"</SPAN
+> all the
+ connections the browser allows, which means connections to
+ other websites can't be opened until the connections currently
+ in use time out.
+ </P
+><P
+> 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 can't.
+ </P
+></DD
+><DT
+>Examples:</DT
+><DD
+><P
+> keep-alive-timeout 300
+ </P
+></DD
+></DL
+></DIV
+></DIV
+><DIV
+CLASS="SECT3"
+><H4
+CLASS="SECT3"
+><A
+NAME="DEFAULT-SERVER-TIMEOUT"
+>7.6.5. default-server-timeout</A
+></H4
+><P
+></P
+><DIV
+CLASS="VARIABLELIST"
+><DL
+><DT
+>Specifies:</DT
+><DD
+><P
+> Assumed server-side keep-alive timeout if not specified by the server.
+ </P
+></DD
+><DT
+>Type of value:</DT
+><DD
+><P
+> <TT
+CLASS="REPLACEABLE"
+><I
+>Time in seconds.</I
+></TT
+>
+ </P
+></DD
+><DT
+>Default value:</DT
+><DD
+><P
+>None</P
+></DD
+><DT
+>Effect if unset:</DT
+><DD
+><P
+> Connections for which the server didn't specify the keep-alive
+ timeout are not reused.
</P
></DD
><DT
>Notes:</DT
><DD
><P
+> Enabling this option significantly increases the number of connections
+ that are reused, provided the <A
+HREF="#KEEP-ALIVE-TIMEOUT"
+TARGET="_top"
+>keep-alive-timeout</A
+> option
+ is also enabled.
+ </P
+><P
+> While it also increases the number of connections problems
+ when <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> tries to reuse a connection that already has
+ been closed on the server side, or is closed while <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+>
+ 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, <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> will simply
+ close the connection and the client is supposed to retry the
+ request without bothering the user.
+ </P
+><P
+> Enabling this option is therefore only recommended if the
+ <A
+HREF="#CONNECTION-SHARING"
+TARGET="_top"
+>connection-sharing</A
+> option
+ is disabled.
+ </P
+><P
+> It is an error to specify a value larger than the <A
+HREF="#KEEP-ALIVE-TIMEOUT"
+TARGET="_top"
+>keep-alive-timeout</A
+> value.
+ </P
+><P
> This option has no effect if <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
</P
></DD
><DT
+>Examples:</DT
+><DD
+><P
+> default-server-timeout 60
+ </P
+></DD
+></DL
+></DIV
+></DIV
+><DIV
+CLASS="SECT3"
+><H4
+CLASS="SECT3"
+><A
+NAME="CONNECTION-SHARING"
+>7.6.6. connection-sharing</A
+></H4
+><P
+></P
+><DIV
+CLASS="VARIABLELIST"
+><DL
+><DT
+>Specifies:</DT
+><DD
+><P
+> Whether or not outgoing connections that have been kept alive
+ should be shared between different incoming connections.
+ </P
+></DD
+><DT
+>Type of value:</DT
+><DD
+><P
+> <TT
+CLASS="REPLACEABLE"
+><I
+>0 or 1</I
+></TT
+>
+ </P
+></DD
+><DT
+>Default value:</DT
+><DD
+><P
+>None</P
+></DD
+><DT
+>Effect if unset:</DT
+><DD
+><P
+> Connections are not shared.
+ </P
+></DD
+><DT
+>Notes:</DT
+><DD
+><P
+> This option has no effect if <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+>
+ has been compiled without keep-alive support, or if it's disabled.
+ </P
+></DD
+><DT
>Notes:</DT
><DD
><P
There are also a few privacy implications you should be aware of.
</P
><P
-> Outgoing connections are shared between clients (if there are more
- than one) and closing the client that initiated the outgoing connection
- does not affect the connection between <SPAN
+> 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 <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
-> and the server unless
- the client's request hasn't been completed yet. If the outgoing connection
- is idle, it will not be closed until either <SPAN
+>
+ and the server unless the client's request hasn't been completed yet.
+ </P
+><P
+> If the outgoing connection is idle, it will not be closed until either
+ <SPAN
CLASS="APPLICATION"
>Privoxy's</SPAN
->
- or the server's timeout is reached. While it's open, the server knows
- that the system running <SPAN
+> or the server's timeout is reached.
+ While it's open, the server knows that the system running <SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
-> is still there.
+> is still
+ there.
+ </P
+><P
+> 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.
+ </P
+><P
+> 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 <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> to keep outgoing connections alive even if the client
+ itself doesn't support it.
+ </P
+><P
+> 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.
+ </P
+><P
+> This option should only be used by experienced users who
+ understand the risks and can weight them against the benefits.
</P
></DD
><DT
>Examples:</DT
><DD
><P
-> keep-alive-timeout 300
+> connection-sharing 1
</P
></DD
></DL
CLASS="SECT3"
><A
NAME="SOCKET-TIMEOUT"
->7.5.9. socket-timeout</A
+>7.6.7. socket-timeout</A
></H4
><P
></P
></DL
></DIV
></DIV
+><DIV
+CLASS="SECT3"
+><H4
+CLASS="SECT3"
+><A
+NAME="MAX-CLIENT-CONNECTIONS"
+>7.6.8. max-client-connections</A
+></H4
+><P
+></P
+><DIV
+CLASS="VARIABLELIST"
+><DL
+><DT
+>Specifies:</DT
+><DD
+><P
+> Maximum number of client connections that will be served.
+ </P
+></DD
+><DT
+>Type of value:</DT
+><DD
+><P
+> <TT
+CLASS="REPLACEABLE"
+><I
+>Positive number.</I
+></TT
+>
+ </P
+></DD
+><DT
+>Default value:</DT
+><DD
+><P
+>None</P
+></DD
+><DT
+>Effect if unset:</DT
+><DD
+><P
+> Connections are served until a resource limit is reached.
+ </P
+></DD
+><DT
+>Notes:</DT
+><DD
+><P
+> <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> creates one thread (or process) for every incoming client
+ connection that isn't rejected based on the access control settings.
+ </P
+><P
+> If the system is powerful enough, <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> can theoretically deal with
+ several hundred (or thousand) connections at the same time, but some
+ operating systems enforce resource limits by shutting down offending
+ processes and their default limits may be below the ones <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> would
+ require under heavy load.
+ </P
+><P
+> Configuring <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> to enforce a connection limit below the thread
+ or process limit used by the operating system makes sure this doesn't
+ happen. Simply increasing the operating system's limit would work too,
+ but if <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> isn't the only application running on the system,
+ you may actually want to limit the resources used by <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+>.
+ </P
+><P
+> If <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+> is only used by a single trusted user, limiting the
+ number of client connections is probably unnecessary. If there
+ are multiple possibly untrusted users you probably still want to
+ additionally use a packet filter to limit the maximal number of
+ incoming connections per client. Otherwise a malicious user could
+ intentionally create a high number of connections to prevent other
+ users from using <SPAN
+CLASS="APPLICATION"
+>Privoxy</SPAN
+>.
+ </P
+><P
+> Obviously using this option only makes sense if you choose a limit
+ below the one enforced by the operating system.
+ </P
+></DD
+><DT
+>Examples:</DT
+><DD
+><P
+> max-client-connections 256
+ </P
+></DD
+></DL
+></DIV
+></DIV
+><DIV
+CLASS="SECT3"
+><H4
+CLASS="SECT3"
+><A
+NAME="HANDLE-AS-EMPTY-DOC-RETURNS-OK"
+>7.6.9. handle-as-empty-doc-returns-ok</A
+></H4
+><P
+></P
+><DIV
+CLASS="VARIABLELIST"
+><DL
+><DT
+>Note:</DT
+><DD
+><P
+> This is a work-around for Firefox bug 492459:
+ <SPAN
+CLASS="QUOTE"
+>" Websites are no longer rendered if SSL requests for JavaScripts are blocked by a proxy.
+ "</SPAN
+>
+ (<A
+HREF="https://bugzilla.mozilla.org/show_bug.cgi?id=492459"
+TARGET="_top"
+>https://bugzilla.mozilla.org/show_bug.cgi?id=492459</A
+>)
+ </P
+></DD
+><DT
+>Specifies:</DT
+><DD
+><P
+> The status code Privoxy returns for pages blocked with
+
+ <TT
+CLASS="LITERAL"
+><A
+HREF="actions-file.html#HANDLE-AS-EMPTY-DOCUMENT"
+TARGET="_top"
+>+handle-as-empty-document</A
+></TT
+>.
+ </P
+></DD
+><DT
+>Type of value:</DT
+><DD
+><P
+> <TT
+CLASS="REPLACEABLE"
+><I
+>0 or 1</I
+></TT
+>
+ </P
+></DD
+><DT
+>Default value:</DT
+><DD
+><P
+>0</P
+></DD
+><DT
+>Effect if unset:</DT
+><DD
+><P
+> Privoxy returns a status 403(forbidden) for all blocked pages.
+ </P
+></DD
+><DT
+>Effect if set:</DT
+><DD
+><P
+> Privoxy returns a status 200(OK) for pages blocked with +handle-as-empty-document
+ and a status 403(Forbidden) for all other blocked pages.
+ </P
+></DD
+></DL
+></DIV
+></DIV
></DIV
><DIV
CLASS="SECT2"
CLASS="SECT2"
><A
NAME="WINDOWS-GUI"
->7.6. Windows GUI Options</A
+>7.7. Windows GUI Options</A
></H2
><P
> <SPAN