7. The Main Configuration File

By default, the main configuration file is named config, with the exception of Windows, where it is named config.txt. Configuration lines consist of an initial keyword followed by a list of values, all separated by whitespace (any number of spaces or tabs). For example:

  confdir /etc/privoxy

Assigns the value /etc/privoxy to the option confdir and thus indicates that the configuration directory is named "/etc/privoxy/".

All options in the config file except for confdir and logdir are optional. Watch out in the below description for what happens if you leave them unset.

The main config file controls all aspects of Privoxy's operation that are not location dependent (i.e. they apply universally, no matter 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.

7.1. Local Set-up Documentation

If you intend to operate Privoxy for more users than just yourself, it might be a good idea to let them know how to reach you, what you block and why you do that, your policies, etc.

7.1.1. user-manual

Specifies:

Location of the Privoxy User Manual.

Type of value:

A fully qualified URI

Default value:

Unset

Effect if unset:

https://www.privoxy.org/version/user-manual/ will be used, where version is the Privoxy version.

Notes:

The User Manual URI is the single best source of information on Privoxy, and is used for help links from some of the internal CGI pages. The manual itself is normally packaged with the binary distributions, so you probably want to set this to a locally installed copy.

Examples:

The best all purpose solution is simply to put the full local PATH to where the User Manual is located:

  user-manual  /usr/share/doc/privoxy/user-manual

The User Manual is then available to anyone with access to Privoxy, by following the built-in URL: http://config.privoxy.org/user-manual/ (or the shortcut: http://p.p/user-manual/).

If the documentation is not on the local system, it can be accessed from a remote server, as:

  user-manual  http://example.com/privoxy/user-manual/

Warning

If set, this option should be the first option in the config file, because it is used while the config file is being read on start-up.

7.1.2. trust-info-url

Specifies:

A URL to be displayed in the error page that users will see if access to an untrusted page is denied.

Type of value:

URL

Default value:

Unset

Effect if unset:

No links are displayed on the "untrusted" error page.

Notes:

The value of this option only matters if the experimental trust mechanism has been activated. (See trustfile below.)

If you use the trust mechanism, it is a good idea to write up some on-line documentation about your trust policy and to specify the URL(s) here. Use multiple times for multiple URLs.

The URL(s) should be added to the trustfile as well, so users don't end up locked out from the information on why they were locked out in the first place!

7.1.3. admin-address

Specifies:

An email address to reach the Privoxy administrator.

Type of value:

Email address

Default value:

Unset

Effect if unset:

No email address is displayed on error pages and the CGI user interface.

Notes:

If both admin-address and proxy-info-url are unset, the whole "Local Privoxy Support" box on all generated pages will not be shown.

7.1.4. proxy-info-url

Specifies:

A URL to documentation about the local Privoxy setup, configuration or policies.

Type of value:

URL

Default value:

Unset

Effect if unset:

No link to local documentation is displayed on error pages and the CGI user interface.

Notes:

If both admin-address and proxy-info-url are unset, the whole "Local Privoxy Support" box on all generated pages will not be shown.

This URL shouldn't be blocked ;-)

7.2. Configuration and Log File Locations

Privoxy can (and normally does) use a number of other files for additional configuration, help and logging. This section of the configuration file tells Privoxy where to find those other files.

The user running Privoxy, must have read permission for all configuration files, and write permission to any files that would be modified, such as log files and actions files.

7.2.1. confdir

Specifies:

The directory where the other configuration files are located.

Type of value:

Path name

Default value:

/etc/privoxy (Unix) or Privoxy installation dir (Windows)

Effect if unset:

Mandatory

Notes:

No trailing "/", please.

7.2.2. templdir

Specifies:

An alternative directory where the templates are loaded from.

Type of value:

Path name

Default value:

unset

Effect if unset:

The templates are assumed to be located in confdir/template.

Notes:

Privoxy's original templates are usually overwritten with each update. Use this option to relocate customized templates that should be kept. As template variables might change between updates, you shouldn't expect templates to work with Privoxy releases other than the one they were part of, though.

7.2.3. temporary-directory

Specifies:

A directory where Privoxy can create temporary files.

Type of value:

Path name

Default value:

unset

Effect if unset:

No temporary files are created, external filters don't work.

Notes:

To execute external filters, Privoxy has to create temporary files. This directive specifies the directory the temporary files should be written to.

It should be a directory only Privoxy (and trusted users) can access.

7.2.4. logdir

Specifies:

The directory where all logging takes place (i.e. where the logfile is located).

Type of value:

Path name

Default value:

/var/log/privoxy (Unix) or Privoxy installation dir (Windows)

Effect if unset:

Mandatory

Notes:

No trailing "/", please.

7.2.5. actionsfile

Specifies:

The actions file(s) to use

Type of value:

Complete file name, relative to confdir

Default values:

  match-all.action # Actions that are applied to all sites and maybe overruled later on.

  default.action   # Main actions file

  user.action      # User customizations

Effect if unset:

No actions are taken at all. More or less neutral proxying.

Notes:

Multiple actionsfile lines are permitted, and are in fact recommended!

The default values are default.action, which is the "main" actions file maintained by the developers, and user.action, where you can make your personal additions.

Actions files contain all the per site and per URL configuration for ad blocking, cookie management, privacy considerations, etc.

7.2.6. filterfile

Specifies:

The filter file(s) to use

Type of value:

File name, relative to confdir

Default value:

default.filter (Unix) or default.filter.txt (Windows)

Effect if unset:

No textual content filtering takes place, i.e. all +filter{name} actions in the actions files are turned neutral.

Notes:

Multiple filterfile lines are permitted.

The filter files contain content modification rules that use regular expressions. These rules permit powerful changes on the content of Web pages, and optionally the headers as well, e.g., you could try to disable your favorite JavaScript annoyances, re-write the actual displayed text, or just have some fun playing buzzword bingo with web pages.

The +filter{name} actions rely on the relevant filter (name) to be defined in a filter file!

A pre-defined filter file called default.filter that contains a number of useful filters for common problems is included in the distribution. See the section on the filter action for a list.

It is recommended to place any locally adapted filters into a separate file, such as user.filter.

7.2.7. logfile

Specifies:

The log file to use

Type of value:

File name, relative to logdir

Default value:

Unset (commented out). When activated: logfile (Unix) or privoxy.log (Windows).

Effect if unset:

No logfile is written.

Notes:

The logfile is where all logging and error messages are written. The level of detail and number of messages are set with the debug option (see below). The logfile can be useful for tracking down a problem with Privoxy (e.g., it's not blocking an ad you think it should block) and it can help you to monitor what your browser is doing.

Depending on the debug options below, the logfile may be a privacy risk if third parties can get access to it. As most users will never look at it, Privoxy only logs fatal errors by default.

For most troubleshooting purposes, you will have to change that, please refer to the debugging section for details.

Any log files must be writable by whatever user Privoxy is being run as (on Unix, default user id is "privoxy").

To prevent the logfile from growing indefinitely, it is recommended to periodically rotate or shorten it. Many operating systems support log rotation out of the box, some require additional software to do it. For details, please refer to the documentation for your operating system.

7.2.8. trustfile

Specifies:

The name of the trust file to use

Type of value:

File name, relative to confdir

Default value:

Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)

Effect if unset:

The entire trust mechanism is disabled.

Notes:

The trust mechanism is an experimental feature for building white-lists and should be used with care. It is NOT recommended for the casual user.

If you specify a trust file, Privoxy will only allow access to sites that are specified in the trustfile. Sites can be listed in one of two ways:

Prepending a ~ character limits access to this site only (and any sub-paths within this site), e.g. ~www.example.com allows access to ~www.example.com/features/news.html, etc.

Or, you can designate sites as trusted referrers, by prepending the name with a + character. The effect is that access to untrusted sites will be granted -- but only if a link from this trusted referrer was used to get there. The link target will then be added to the "trustfile" so that future, direct accesses will be granted. Sites added via this mechanism do not become trusted referrers themselves (i.e. they are added with a ~ designation). There is a limit of 512 such entries, after which new entries will not be made.

If you use the + operator in the trust file, it may grow considerably over time.

It is recommended that Privoxy be compiled with the --disable-force, --disable-toggle and --disable-editor options, if this feature is to be used.

Possible applications include limiting Internet access for children.

7.3. Debugging

These options are mainly useful when tracing a problem. Note that you might also want to invoke Privoxy with the --no-daemon command line option when debugging.

7.3.1. debug

Specifies:

Key values that determine what information gets logged.

Type of value:

Integer values

Default value:

0 (i.e.: only fatal errors (that cause Privoxy to exit) are logged)

Effect if unset:

Default value is used (see above).

Notes:

The available debug levels are:

  debug     1 # Log the destination for each request. See also debug 1024.
  debug     2 # show each connection status
  debug     4 # show tagging-related messages
  debug     8 # show header parsing
  debug    16 # log all data written to the network
  debug    32 # debug force feature
  debug    64 # debug regular expression filters
  debug   128 # debug redirects
  debug   256 # debug GIF de-animation
  debug   512 # Common Log Format
  debug  1024 # Log the destination for requests Privoxy didn't let through, and the reason why.
  debug  2048 # CGI user interface
  debug  4096 # Startup banner and warnings.
  debug  8192 # Non-fatal errors
  debug 32768 # log all data read from the network
  debug 65536 # Log the applying actions

To select multiple debug levels, you can either add them or use multiple debug lines.

A debug level of 1 is informative because it will show you each request as it happens. 1, 1024, 4096 and 8192 are recommended so that you will notice when things go wrong. The other levels are probably only of interest if you are hunting down a specific problem. They can produce a hell of an output (especially 16).

If you are used to the more verbose settings, simply enable the debug lines below again.

If you want to use pure CLF (Common Log Format), you should set "debug 512" ONLY and not enable anything else.

Privoxy has a hard-coded limit for the length of log messages. If it's reached, messages are logged truncated and marked with "... [too long, truncated]".

Please don't file any support requests without trying to reproduce the problem with increased debug level first. Once you read the log messages, you may even be able to solve the problem on your own.

7.3.2. single-threaded

Specifies:

Whether to run only one server thread.

Type of value:

1 or 0

Default value:

0

Effect if unset:

Multi-threaded (or, where unavailable: forked) operation, i.e. the ability to serve multiple requests simultaneously.

Notes:

This option is only there for debugging purposes. It will drastically reduce performance.

7.3.3. hostname

Specifies:

The hostname shown on the CGI pages.

Type of value:

Text

Default value:

Unset

Effect if unset:

The hostname provided by the operating system is used.

Notes:

On some misconfigured systems resolving the hostname fails or takes too much time and slows Privoxy down. Setting a fixed hostname works around the problem.

In other circumstances it might be desirable to show a hostname other than the one returned by the operating system. For example if the system has several different hostnames and you don't want to use the first one.

Note that Privoxy does not validate the specified hostname value.

7.4. Access Control and Security

This section of the config file controls the security-relevant aspects of Privoxy's configuration.

7.4.1. listen-address

Specifies:

The address and TCP port on which Privoxy will listen for client requests.

Type of value:

[IP-Address]:Port

[Hostname]:Port

Default value:

127.0.0.1:8118

Effect if unset:

Bind to 127.0.0.1 (IPv4 localhost), port 8118. This is suitable and recommended for home users who run Privoxy on the same machine as their browser.

Notes:

You will need to configure your browser(s) to this proxy address and port.

If you already have another service running on port 8118, or if you want to serve requests from other machines (e.g. on your local network) as well, you will need to override the default.

You can use this statement multiple times to make Privoxy listen on more ports or more IP addresses. Suitable if your operating system does not support sharing IPv6 and IPv4 protocols on the same socket.

If a hostname is used instead of an IP address, Privoxy will try to resolve it to an IP address and if there are multiple, use the first one returned.

If the address for the hostname isn't already known on the system (for example because it's in /etc/hostname), this may result in DNS traffic.

If the specified address isn't available on the system, or if the hostname can't be resolved, Privoxy will fail to start. On GNU/Linux, and other platforms that can listen on not yet assigned IP addresses, Privoxy will start and will listen on the specified address whenever the IP address is assigned to the system

IPv6 addresses containing colons have to be quoted by brackets. They can only be used if Privoxy has been compiled with IPv6 support. If you aren't sure if your version supports it, have a look at http://config.privoxy.org/show-status.

Some operating systems will prefer IPv6 to IPv4 addresses even if the system has no IPv6 connectivity which is usually not expected by the user. Some even rely on DNS to resolve localhost which mean the "localhost" address used may not actually be local.

It is therefore recommended to explicitly configure the intended IP address instead of relying on the operating system, unless there's a strong reason not to.

If you leave out the address, Privoxy will bind to all IPv4 interfaces (addresses) on your machine and may become reachable from the Internet and/or the local network. Be aware that some GNU/Linux distributions modify that behaviour without updating the documentation. Check for non-standard patches if your Privoxy version behaves differently.

If you configure Privoxy to be reachable from the network, consider using access control lists (ACL's, see below), and/or a firewall.

If you open Privoxy to untrusted users, you will also want to make sure that the following actions are disabled: enable-edit-actions and enable-remote-toggle

Example:

Suppose you are running Privoxy on a machine which has the address 192.168.0.1 on your local private network (192.168.0.0) and has another outside connection with a different address. You want it to serve requests from inside only:

  listen-address  192.168.0.1:8118

Suppose you are running Privoxy on an IPv6-capable machine and you want it to listen on the IPv6 address of the loopback device:

  listen-address [::1]:8118

7.4.2. toggle

Specifies:

Initial state of "toggle" status

Type of value:

1 or 0

Default value:

1

Effect if unset:

Act as if toggled on

Notes:

If set to 0, Privoxy will start in "toggled off" mode, i.e. mostly behave like a normal, content-neutral proxy with both ad blocking and content filtering disabled. See enable-remote-toggle below.

7.4.3. enable-remote-toggle

Specifies:

Whether or not the web-based toggle feature may be used

Type of value:

0 or 1

Default value:

0

Effect if unset:

The web-based toggle feature is disabled.

Notes:

When toggled off, Privoxy mostly acts like a normal, content-neutral proxy, i.e. doesn't block ads or filter content.

Access to the toggle feature can not be controlled separately by "ACLs" or HTTP authentication, so that everybody who can access Privoxy (see "ACLs" and listen-address above) can toggle it for all users. So this option is not recommended for multi-user environments with untrusted users.

Note that malicious client side code (e.g Java) is also capable of using this option.

As a lot of Privoxy users don't read documentation, this feature is disabled by default.

Note that you must have compiled Privoxy with support for this feature, otherwise this option has no effect.

7.4.4. enable-remote-http-toggle

Specifies:

Whether or not Privoxy recognizes special HTTP headers to change its behaviour.

Type of value:

0 or 1

Default value:

0

Effect if unset:

Privoxy ignores special HTTP headers.

Notes:

When toggled on, the client can change Privoxy's behaviour by setting special HTTP headers. Currently the only supported special header is "X-Filter: No", to disable filtering for the ongoing request, even if it is enabled in one of the action files.

This feature is disabled by default. If you are using Privoxy in a environment with trusted clients, you may enable this feature at your discretion. Note that malicious client side code (e.g Java) is also capable of using this feature.

This option will be removed in future releases as it has been obsoleted by the more general header taggers.

7.4.5. enable-edit-actions

Specifies:

Whether or not the web-based actions file editor may be used

Type of value:

0 or 1

Default value:

0

Effect if unset:

The web-based actions file editor is disabled.

Notes:

Access to the editor can not be controlled separately by "ACLs" or HTTP authentication, so that everybody who can access Privoxy (see "ACLs" and listen-address above) can modify its configuration for all users.

This option is not recommended for environments with untrusted users and as a lot of Privoxy users don't read documentation, this feature is disabled by default.

Note that malicious client side code (e.g Java) is also capable of using the actions editor and you shouldn't enable this options unless you understand the consequences and are sure your browser is configured correctly.

Note that you must have compiled Privoxy with support for this feature, otherwise this option has no effect.

7.4.6. enforce-blocks

Specifies:

Whether the user is allowed to ignore blocks and can "go there anyway".

Type of value:

0 or 1

Default value:

0

Effect if unset:

Blocks are not enforced.

Notes:

Privoxy is mainly used to block and filter requests as a service to the user, for example to block ads and other junk that clogs the pipes. Privoxy's configuration isn't perfect and sometimes innocent pages are blocked. In this situation it makes sense to allow the user to enforce the request and have Privoxy ignore the block.

In the default configuration Privoxy's "Blocked" page contains a "go there anyway" link to adds a special string (the force prefix) to the request URL. If that link is used, Privoxy will detect the force prefix, remove it again and let the request pass.

Of course Privoxy can also be used to enforce a network policy. In that case the user obviously should not be able to bypass any blocks, and that's what the "enforce-blocks" option is for. If it's enabled, Privoxy hides the "go there anyway" link. If the user adds the force prefix by hand, it will not be accepted and the circumvention attempt is logged.

Example:

enforce-blocks 1

7.4.7. ACLs: permit-access and deny-access

Specifies:

Who can access what.

Type of value:

src_addr[:port][/src_masklen] [dst_addr[:port][/dst_masklen]]

Where src_addr and dst_addr are IPv4 addresses in dotted decimal notation or valid DNS names, port is a port number, and src_masklen and dst_masklen are subnet masks in CIDR notation, i.e. integer values from 2 to 30 representing the length (in bits) of the network address. The masks and the whole destination part are optional.

If your system implements RFC 3493, then src_addr and dst_addr can be IPv6 addresses delimited by brackets, port can be a number or a service name, and src_masklen and dst_masklen can be a number from 0 to 128.

Default value:

Unset

If no port is specified, any port will match. If no src_masklen or src_masklen is given, the complete IP address has to match (i.e. 32 bits for IPv4 and 128 bits for IPv6).

Effect if unset:

Don't restrict access further than implied by listen-address

Notes:

Access controls are included at the request of ISPs and systems administrators, and are not usually needed by individual users. For a typical home user, it will normally suffice to ensure that Privoxy only listens on the localhost (127.0.0.1) or internal (home) network address by means of the listen-address option.

Please see the warnings in the FAQ that Privoxy is not intended to be a substitute for a firewall or to encourage anyone to defer addressing basic security weaknesses.

Multiple ACL lines are OK. If any ACLs are specified, Privoxy only talks to IP addresses that match at least one permit-access line and don't match any subsequent deny-access line. In other words, the last match wins, with the default being deny-access.

If Privoxy is using a forwarder (see forward below) for a particular destination URL, the dst_addr that is examined is the address of the forwarder and NOT the address of the ultimate target. This is necessary because it may be impossible for the local Privoxy to determine the IP address of the ultimate target (that's often what gateways are used for).

You should prefer using IP addresses over DNS names, because the address lookups take time. All DNS names must resolve! You can not use domain patterns like "*.org" or partial domain names. If a DNS name resolves to multiple IP addresses, only the first one is used.

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). Privoxy can handle it and maps such ACL addresses automatically.

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).

Examples:

Explicitly define the default behavior if no ACL and listen-address are set: "localhost" is OK. The absence of a dst_addr implies that all destination addresses are OK:

  permit-access  localhost

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):

  permit-access  www.privoxy.org/24 www.example.com/32

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:

  permit-access  192.168.45.64/26
  deny-access    192.168.45.73    www.dirty-stuff.example.com

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):

  permit-access  192.0.2.0/24

This is equivalent to the following line even if listening on an IPv4 address (not supported on all platforms):

  permit-access  [::ffff:192.0.2.0]/120

7.4.8. buffer-limit

Specifies:

Maximum size of the buffer for content filtering.

Type of value:

Size in Kbytes

Default value:

4096

Effect if unset:

Use a 4MB (4096 KB) limit.

Notes:

For content filtering, i.e. the +filter and +deanimate-gif actions, it is necessary that Privoxy 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.

When a document buffer size reaches the buffer-limit, 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 buffer-limit Kbytes each, unless you have enabled "single-threaded" above.

7.4.9. enable-proxy-authentication-forwarding

Specifies:

Whether or not proxy authentication through Privoxy should work.

Type of value:

0 or 1

Default value:

0

Effect if unset:

Proxy authentication headers are removed.

Notes:

Privoxy itself does not support proxy authentication, but can allow clients to authenticate against Privoxy's parent proxy.

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.

If this option is enabled the headers are forwarded.

Enabling this option is not recommended 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.

7.4.10. trusted-cgi-referer

Specifies:

A trusted website or webpage whose links can be followed to reach sensitive CGI pages

Type of value:

URL or URL prefix

Default value:

Unset

Effect if unset:

No external pages are considered trusted referers.

Notes:

Before Privoxy accepts configuration changes through CGI pages like client-tags or the remote toggle, it checks the Referer header to see if the request comes from a trusted source.

By default only the webinterface domains config.privoxy.org and p.p are considered trustworthy. Requests originating from other domains are rejected to prevent third-parties from modifiying Privoxy's state by e.g. embedding images that result in CGI requests.

In some environments it may be desirable to embed links to CGI pages on external pages, for example on an Intranet homepage the Privoxy admin controls.

The "trusted-cgi-referer" option can be used to add that page, or the whole domain, as trusted source so the resulting requests aren't rejected. Requests are accepted if the specified trusted-cgi-refer is the prefix of the Referer.

If the trusted source is supposed to access the CGI pages via JavaScript the cors-allowed-origin option can be used.

Warning

Declaring pages the admin doesn't control trustworthy may allow malicious third parties to modify Privoxy's internal state against the user's wishes and without the user's knowledge.

7.4.11. cors-allowed-origin

Specifies:

A trusted website which can access Privoxy's CGI pages through JavaScript.

Type of value:

URL

Default value:

Unset

Effect if unset:

No external sites get access via cross-origin resource sharing.

Notes:

Modern browsers by default prevent cross-origin requests made via JavaScript to Privoxy's CGI interface even if Privoxy would trust the referer because it's white listed via the trusted-cgi-referer directive.

Cross-origin resource sharing (CORS) is a mechanism to allow cross-origin requests.

The "cors-allowed-origin" option can be used to specify a domain that is allowed to make requests to Privoxy CGI interface via JavaScript. It is used in combination with the trusted-cgi-referer directive.

Warning

Declaring domains the admin doesn't control trustworthy may allow malicious third parties to modify Privoxy's internal state against the user's wishes and without the user's knowledge.

7.5. Forwarding

This feature allows routing of HTTP requests through a chain of multiple proxies.

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 Privoxy runs on has no direct Internet access.

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 "Etag" 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.

Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS 4A protocols.

7.5.1. forward

Specifies:

To which parent HTTP proxy specific requests should be routed.

Type of value:

target_pattern http_parent[:port]

where target_pattern is a URL pattern that specifies to which requests (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs". http_parent[:port] 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 (.) to denote "no forwarding".

Default value:

Unset

Effect if unset:

Don't use parent HTTP proxies.

Notes:

If http_parent is ".", then requests are not forwarded to another HTTP proxy but are made directly to the web servers.

http_parent can be a numerical IPv6 address (if RFC 3493 is implemented). To prevent clashes with the port delimiter, the whole IP address has to be put into brackets. On the other hand a target_pattern containing an IPv6 address has to be put into angle brackets (normal brackets are reserved for regular expressions already).

Multiple lines are OK, they are checked in sequence, and the last match wins.

Examples:

Everything goes to an example parent proxy, except SSL on port 443 (which it doesn't handle):

  forward   /      parent-proxy.example.org:8080
  forward   :443   .

Everything goes to our example ISP's caching proxy, except for requests to that ISP's sites:

  forward   /                  caching-proxy.isp.example.net:8000
  forward   .isp.example.net   .

Parent proxy specified by an IPv6 address:

  forward   /                   [2001:DB8::1]:8000

Suppose your parent proxy doesn't support IPv6:

  forward  /                        parent-proxy.example.org:8000
  forward  ipv6-server.example.org  .
  forward  <[2-3][0-9a-f][0-9a-f][0-9a-f]:*>   .

7.5.2. forward-socks4, forward-socks4a, forward-socks5 and forward-socks5t

Specifies:

Through which SOCKS proxy (and optionally to which parent HTTP proxy) specific requests should be routed.

Type of value:

target_pattern [user:pass@]socks_proxy[:port] http_parent[:port]

where target_pattern is a URL pattern that specifies to which requests (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs". http_parent and socks_proxy are IP addresses in dotted decimal notation or valid DNS names (http_parent may be "." to denote "no HTTP forwarding"), and the optional port parameters are TCP ports, i.e. integer values from 1 to 65535. user and pass can be used for SOCKS5 authentication if required.

Default value:

Unset

Effect if unset:

Don't use SOCKS proxies.

Notes:

Multiple lines are OK, they are checked in sequence, and the last match wins.

The difference between forward-socks4 and forward-socks4a 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.

With forward-socks5 the DNS resolution will happen on the remote server as well.

forward-socks5t works like vanilla forward-socks5 but lets Privoxy 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.

socks_proxy and http_parent can be a numerical IPv6 address (if RFC 3493 is implemented). To prevent clashes with the port delimiter, the whole IP address has to be put into brackets. On the other hand a target_pattern containing an IPv6 address has to be put into angle brackets (normal brackets are reserved for regular expressions already).

If http_parent is ".", then requests are not forwarded to another HTTP proxy but are made (HTTP-wise) directly to the web servers, albeit through a SOCKS proxy.

Examples:

From the company example.com, direct connections are made to all "internal" domains, but everything outbound goes through their ISP's proxy by way of example.com's corporate SOCKS 4A gateway to the Internet.

  forward-socks4a   /              socks-gw.example.com:1080  www-cache.isp.example.net:8080
  forward           .example.com   .

A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this:

  forward-socks4   /               socks-gw.example.com:1080  .

To connect SOCKS5 proxy which requires username/password authentication:

  forward-socks5   /               user:pass@socks-gw.example.com:1080  .

To chain Privoxy and Tor, both running on the same system, you would use something like:

  forward-socks5t   /               127.0.0.1:9050 .

Note that if you got Tor through one of the bundles, you may have to change the port from 9050 to 9150 (or even another one). For details, please check the documentation on the Tor website.

The public Tor 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:

  forward         192.168.*.*/     .
  forward          10.*.*.*/       .
  forward         127.*.*.*/       .

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 Privoxy 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.

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:

 forward           localhost/     .

7.5.3. Advanced Forwarding Examples

If you have links to multiple ISPs that provide various special content only to their subscribers, you can configure multiple Privoxies which have connections to the respective ISPs to act as forwarders to each other, so that your users can see the internal content of all ISPs.

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 Privoxy. Their forwarding configuration can look like this:

host-a:

  forward    /           .
  forward    .isp-b.example.net  host-b:8118

host-b:

  forward    /           .
  forward    .isp-a.example.org  host-a:8118

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.

If you intend to chain Privoxy and squid locally, then chaining as browser -> squid -> privoxy is the recommended way.

Assuming that Privoxy and squid run on the same box, your squid configuration could then look like this:

  # 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

You would then need to change your browser's proxy settings to squid's address and port. Squid normally uses port 3128. If unsure consult http_port in squid.conf.

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 antivir.example.com, port 8010:

  forward   /                          .
  forward   /.*\.(exe|com|dll|zip)$    antivir.example.com:8010

7.5.4. forwarded-connect-retries

Specifies:

How often Privoxy retries if a forwarded connection request fails.

Type of value:

Number of retries.

Default value:

0

Effect if unset:

Connections forwarded through other proxies are treated like direct connections and no retry attempts are made.

Notes:

forwarded-connect-ret