Junkbuster User Manual $Id: user-manual.sgml,v 1.47 2002/03/11 13:13:27 swa Exp $ By: Junkbuster Developers The user manual gives users information on how to install, configure and use Internet Junkbuster. Internet Junkbuster is a web proxy with advanced filtering capabilities for protecting privacy, filtering web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other obnoxious Internet Junk. Junkbuster has a very flexible configuration and can be customized to suit individual needs and tastes. Internet Junkbuster has application for both stand-alone systems and multi-user networks. You can find the latest version of the user manual at http://ijbswa.sourceforge.net/user-manual/. Introduction Internet Junkbuster is a web proxy with advanced filtering capabilities for protecting privacy, filtering and modifying web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other obnoxious Internet Junk. Junkbuster has a very flexible configuration and can be customized to suit individual needs and tastes. Internet Junkbuster has application for both stand-alone systems and multi-user networks. This documentation is included with the current BETA version of Internet Junkbuster and is mostly complete at this point. The most up to date reference for the time being is still the comments in the source files and in the individual configuration files. Development of version 3.0 is currently nearing completion, and includes many significant changes and enhancements over earlier versions. The target release date for stable v3.0 is soon ;-) Since this is a BETA version, not all new features are well tested. This documentation may be slightly out of sync as a result (especially with CVS sources). And there may be bugs, though hopefully not many! New Features In addition to Junkbuster's traditional features of ad and banner blocking and cookie management, this is a list of new features currently under development: Integrated browser based configuration and control utility (http://i.j.b). Browser-based tracing of rule and filter effects. Modularized configuration that will allow for system wide settings, and individual user settings. (not implemented yet, probably a 3.1 feature) Blocking of annoying pop-up browser windows. HTTP/1.1 compliant (most, but not all 1.1 features are supported). Support for Perl Compatible Regular Expressions in the configuration files, and generally a more sophisticated and flexible configuration syntax over previous versions. GIF de-animation. Web page content filtering (removes banners based on size, invisible web-bugs, JavaScript, pop-ups, status bar abuse, etc.) Bypass many click-tracking scripts (avoids script redirection). Multi-threaded (POSIX and native threads). Auto-detection and re-reading of config file changes. User-customizable HTML templates (e.g. 404 error page). Improved cookie management features (e.g. session based cookies). Builds from source on most UNIX-like systems. Packages available for: Linux (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11 and AmigaOS. In addition, the configuration is much more powerful and versatile over-all. Installation Junkbuster is available as raw source code, or pre-compiled binaries. See the Junkbuster Home Page for binaries and current release info. Junkbuster is also available via CVS. This is the recommended approach at this time. But please be aware that CVS is constantly changing, and it may break in mysterious ways. Source For gzipped tar archives, unpack the source: tar xzvf ijb_source_* [.tgz or .tar.gz] cd ijb_source_2.9.11_beta For retrieving the current CVS sources, you'll need the CVS package installed first. To download CVS source: cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current cd current This will create a directory named current/, which will contain the source tree. Then, in either case, to build from tarball/CVS source: ./configure (--help to see options) make (the make from gnu, gmake for *BSD) su make -n install (to see where all the files will go) make install (to really install) For Redhat and SuSE Linux RPM packages, see below. Red Hat To build Redhat RPM packages, install source as above. Then: autoheader [suggested for CVS source] autoconf [suggested for CVS source] ./configure make redhat-dist This will create both binary and src RPMs in the usual places. Example:    /usr/src/redhat/RPMS/i686/junkbuster-2.9.11-1.i686.rpm    /usr/src/redhat/SRPMS/junkbuster-2.9.11-1.src.rpm To install, of course: rpm -Uvv /usr/src/redhat/RPMS/i686/junkbuster-2.9.11-1.i686.rpm This will place the Junkbuster configuration files in /etc/junkbuster/, and log files in /var/log/junkbuster/. SuSE To build SuSE RPM packages, install source as above. Then: autoheader [suggested for CVS source] autoconf [suggested for CVS source] ./configure make suse-dist This will create both binary and src RPMs in the usual places. Example:    /usr/src/packages/RPMS/i686/junkbuster-2.9.11-1.i686.rpm    /usr/src/packages/SRPMS/junkbuster-2.9.11-1.src.rpm To install, of course: rpm -Uvv /usr/src/packages/RPMS/i686/junkbuster-2.9.11-1.i686.rpm This will place the Junkbuster configuration files in /etc/junkbuster/, and log files in /var/log/junkbuster/. OS/2 Junkbuster is packaged in a WarpIN self- installing archive. The self-installing program will be named depending on the release version, something like: ijbos2_setup_1.2.3.exe. In order to install it, simply run this executable or double-click on its icon and follow the WarpIN installation panels. A shadow of the Junkbuster executable will be placed in your startup folder so it will start automatically whenever OS/2 starts. The directory you choose to install Junkbuster into will contain all of the configuration files. If you would like to build binary images on OS/2 yourself, you will need a few Unix-like tools: autoconf, autoheader and sh. These tools will be used to create the required config.h file, which is not part of the source distribution because it differs based on platform. You will also need a compiler. The distribution has been created using IBM VisualAge compilers, but you can use any compiler you like. GCC/EMX has the disadvantage of needing to be single-threaded due to a limitation of EMX's implementation of the select() socket call. In addition to needing the source code distribution as outlined earlier, you will want to extract the os2seutp directory from CVS: cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co os2setup This will create a directory named os2setup/, which will contain the Makefile.vac makefile and os2build.cmd which is used to completely create the binary distribution. The sequence of events for building the executable for yourself goes something like this: cd current autoheader autoconf sh configure cd ..\os2setup nmake -f Makefile.vac You will see this sequence laid out in os2build.cmd. Windows Click-click. (I need help on this. Not a clue here. Also for configuration section below. HB.) Other Some quick notes on other Operating Systems. For FreeBSD (and other *BSDs?), the build will require gmake instead of the included make. gmake is available from http://www.gnu.org. The rest should be the same as above for Linux/Unix. JunkBuster Configuration All JunkBuster configuration is kept in text files. These files can be edited with a text editor. Many important aspects of JunkBuster can also be controlled easily with a web browser. Controlling Junkbuster with Your Web Browser JunkBuster can be reached by the special URL http://i.j.b/ (or alternately http://ijbswa.sourceforge.net/config/, which is an internal page. You will see the following section: Please choose from the following options: * Show information about the current configuration * Show the source code version numbers * Show the client's request headers. * Show which actions apply to a URL and why * Toggle JunkBuster on or off * Edit the actions list This should be self-explanatory. Note the last item is an editor for the actions list, which is where much of the ad, banner, cookie, and URL blocking magic is configured as well as other advanced features of Junkbuster. This is an easy way to adjust various aspects of Junkbuster configuration. The actions file, and other configuration files, are explained in detail below. Junkbuster will automatically detect any changes to these files. Toggle JunkBuster On or Off is handy for sites that might have problems with your current actions and filters, or just to test if a site misbehaves, whether it is JunkBuster causing the problem or not. Junkbuster continues to run as a proxy in this case, but all filtering is disabled. Configuration Files Overview For Unix, *BSD and Linux, all configuration files are located in /etc/junkbuster/ by default. For MS Windows, OS/2, and AmigaOS these are all in the same directory as the Junkbuster executable. The name and number of configuration files has changed from previous versions, and is subject to change as development progresses. The installed defaults provide a reasonable starting point, though possibly aggressive by some standards. For the time being, there are only three default configuration files (this will change in time): The main configuration file is named config on Linux, Unix, BSD, OS/2, and AmigaOS and config.txt on Windows. The ijb.action file is used to define various actions relating to images, banners, pop-ups, access restrictions, banners and cookies. There is a CGI based editor for this file that can be accessed via http://i.j.b. (Other actions files are included as well with differing levels of filtering and blocking, e.g. ijb-basic.action.) The re_filterfile file can be used to re-write the raw page content, including viewable text as well as embedded HTML and JavaScript, and whatever else lurks on any given web page. ijb.action and re_filterfile can use Perl style regular expressions for maximum flexibility. All files use the # character to denote a comment. Such lines are not processed by Junkbuster. After making any changes, there is no need to restart Junkbuster in order for the changes to take effect. Junkbuster should detect such changes automatically. While under development, the configuration content is subject to change. The below documentation may not be accurate by the time you read this. Also, what constitutes a default setting, may change, so please check all your configuration files on important issues. The Main Configuration File Again, the main configuration file is named config on Linux/Unix/BSD and OS/2, and config.txt on Windows. 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: blockfile blocklist.ini Indicates that the blockfile is named blocklist.ini. A # indicates a comment. Any part of a line following a # is ignored, except if the # is preceded by a \. Thus, by placing a # at the start of an existing configuration line, you can make it a comment and it will be treated as if it weren't there. This is called commenting out an option and can be useful to turn off features: If you comment out the logfile line, junkbuster will not log to a file at all. Watch for the default: section in each explanation to see what happens if the option is left unset (or commented out). Long lines can be continued on the next line by using a \ as the very last character. There are various aspects of Junkbuster behavior that can be tuned. Defining Other Configuration Files Junkbuster can use a number of other files to tell it what ads to block, what cookies to accept, etc. This section of the configuration file tells Junkbuster where to find all those other files. On Windows and AmigaOS, Junkbuster looks for these files in the same directory as the executable. On Unix and OS/2, Junkbuster looks for these files in the current working directory. In either case, an absolute path name can be used to avoid problems. When development goes modular and multi-user, the blocker, filter, and per-user config will be stored in subdirectories of confdir. For now, only confdir/templates is used for storing HTML templates for CGI results. The location of the configuration files: confdir /etc/junkbuster # No trailing /, please. The directory where all logging (i.e. logfile and jarfile) takes place. No trailing /, please: logdir /var/log/junkbuster Note that all file specifications below are relative to the above two directories! The ijb.action file contains patterns to specify the actions to apply to requests for each site. Default: Cookies to and from all destinations are kept only during the current browser session (i.e. they are not saved to disk). Pop-ups are disabled for all sites. All sites are filtered through selected sections of re_filterfile. No sites are blocked. The JunkBuster logo is displayed for filtered ads and other images . The syntax of this file is explained in detail below. actionsfile ijb.action The re_filterfile file contains content modification rules that use regular expressions. These rules permit powerful changes on the content of Web pages, e.g., you could disable your favorite JavaScript annoyances, re-write the actual displayed text, or just have some fun replacing Microsoft with MicroSuck wherever it appears on a Web page. Default: whatever the developers are playing with :-/ Filtering requires buffering the page content, which may appear to slow down page rendering since nothing is displayed until all content has passed the filters. (It does not really take longer, but seems that way since the page is not incrementally displayed.) This effect will be more noticeable on slower connections. re_filterfile re_filterfile The logfile is where all logging and error messages are written. The logfile can be useful for tracking down a problem with Junkbuster (e.g., it's not blocking an ad you think it should block) but in most cases you probably will never look at it. Your logfile will grow indefinitely, and you will probably want to periodically remove it. On Unix systems, you can do this with a cron job (see man cron). For Redhat, a logrotate script has been included. On SuSE Linux systems, you can place a line like /var/log/junkbuster.* +1024k 644 nobody.nogroup in /etc/logfiles, with the effect that cron.daily will automatically archive, gzip, and empty the log, when it exceeds 1M size. Default: Log to the a file named logfile. Comment out to disable logging. logfile logfile The jarfile defines where Junkbuster stores the cookies it intercepts. Note that if you use a jarfile, it may grow quite large. Default: Don't store intercepted cookies. #jarfile jarfile If you specify a trustfile, Junkbuster will only allow access to sites that are named in the trustfile. You can also mark sites as trusted referrers, with the effect that access to untrusted sites will be granted, if a link from a trusted referrer was used. The link target will then be added to the trustfile. This is a very restrictive feature that typical users most probably want to leave disabled. Default: Disabled, don't use the trust mechanism. #trustfile trust If you use the trust mechanism, it is a good idea to write up some on-line documentation about your blocking policy and to specify the URL(s) here. They will appear on the page that your users receive when they try to access untrusted content. Use multiple times for multiple URLs. Default: Don't display links on the untrusted info page. trust-info-url http://www.your-site.com/why_we_block.html trust-info-url http://www.your-site.com/what_we_allow.html Other Configuration Options This part of the configuration file contains options that control how Junkbuster operates. Admin-address should be set to the email address of the proxy administrator. It is used in many of the proxy-generated pages. Default: fill@me.in.please. #admin-address fill@me.in.please Proxy-info-url can be set to a URL that contains more info about this Junkbuster installation, it's configuration and policies. It is used in many of the proxy-generated pages and its use is highly recommended in multi-user installations, since your users will want to know why certain content is blocked or modified. Default: Don't show a link to on-line documentation. proxy-info-url http://www.your-site.com/proxy.html Listen-address specifies the address and port where Junkbuster will listen for connections from your Web browser. The default is to listen on the localhost port 8118, and this is suitable for most users. (In your web browser, under proxy configuration, list the proxy server as localhost and the port as 8118). 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. The syntax is listen-address [<ip-address>]:<port>. If you leave out the IP address, junkbuster will bind to all interfaces (addresses) on your machine and may become reachable from the Internet. In that case, consider using access control lists (acl's) (see aclfile above), or a firewall. For example, suppose you are running Junkbuster 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 If you want it to listen on all addresses (including the outside connection): listen-address :8118 If you do this, consider using ACLs (see aclfile above). Note: you will need to point your browser(s) to the address and port that you have configured here. Default: localhost:8118 (127.0.0.1:8118). The debug option sets the level of debugging information to log in the logfile (and to the console in the Windows version). A debug level of 1 is informative because it will show you each request as it happens. Higher levels of debug are probably only of interest to developers. debug 1 # GPC = show each GET/POST/CONNECT request debug 2 # CONN = show each connection status debug 4 # IO = show I/O status debug 8 # HDR = show header parsing debug 16 # LOG = log all data into the logfile debug 32 # FRC = debug force feature debug 64 # REF = debug regular expression filter debug 128 # = debug fast redirects debug 256 # = debug GIF de-animation debug 512 # CLF = Common Log Format debug 1024 # = debug kill pop-ups debug 4096 # INFO = Startup banner and warnings. debug 8192 # ERROR = Non-fatal errors It is highly recommended that you enable ERROR reporting (debug 8192), at least until the next stable release. The reporting of FATAL errors (i.e. ones which crash JunkBuster) is always on and cannot be disabled. If you want to use CLF (Common Log Format), you should set debug 512 ONLY, do not enable anything else. Multiple debug directives, are OK - they're logical-OR'd together. debug 15 # same as setting the first 4 listed above Default: debug 1 # URLs debug 4096 # Info debug 8192 # Errors - *we highly recommended enabling this* Junkbuster normally uses multi-threading, a software technique that permits it to handle many different requests simultaneously. In some cases you may wish to disable this -- particularly if you're trying to debug a problem. The single-threaded option forces Junkbuster to handle requests sequentially. Default: Multi-threaded mode. #single-threaded toggle allows you to temporarily disable all Junkbuster's filtering. Just set toggle 0. The Windows version of Junkbuster puts an icon in the system tray, which also allows you to change this option. If you right-click on that icon (or select the Options menu), one choice is Enable. Clicking on enable toggles Junkbuster on and off. This is useful if you want to temporarily disable Junkbuster, e.g., to access a site that requires cookies which you would otherwise have blocked. This can also be toggled via a web browser at the Junkbuster internal address of http://i.j.b on any platform. toggle 1 means Junkbuster runs normally, toggle 0 means that Junkbuster becomes a non-anonymizing non-blocking proxy. Default: 1 (on). toggle 1 For content filtering, i.e. the +filter and +deanimate-gif actions, it is necessary that Junkbuster 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. The buffer-limit option lets you set the maximum size in Kbytes that each buffer may use. When the documents buffer exceeds this size, it is flushed to the client unfiltered and no further attempt to filter the rest of it is made. Remember that there may multiple threads running, which might require increasing the buffer-limit Kbytes each, unless you have enabled single-threaded above. buffer-limit 4069 To enable the web-based ijb.action file editor set enable-edit-actions to 1, or 0 to disable. Note that you must have compiled JunkBuster with support for this feature, otherwise this option has no effect. This internal page can be reached at http://i.j.b. Security note: If this is enabled, anyone who can use the proxy can edit the actions file, and their changes will affect all users. For shared proxies, you probably want to disable this. Default: enabled. enable-edit-actions 1 Allow JunkBuster to be toggled on and off remotely, using your web browser. Set enable-remote-toggleto 1 to enable, and 0 to disable. Note that you must have compiled JunkBuster with support for this feature, otherwise this option has no effect. Security note: If this is enabled, anyone who can use the proxy can toggle it on or off (see http://i.j.b), and their changes will affect all users. For shared proxies, you probably want to disable this. Default: enabled. enable-remote-toggle 1 Access Control List (ACL) Access controls are included at the request of some ISPs and systems administrators, and are not usually needed by individual users. Please note the warnings in the FAQ that this proxy is not intended to be a substitute for a firewall or to encourage anyone to defer addressing basic security weaknesses. If no access settings are specified, the proxy talks to anyone that connects. If any access settings file are specified, then the proxy talks only to IP addresses permitted somewhere in this file and not denied later in this file. Summary -- if using an ACL: Client must have permission to receive service. LAST match in ACL wins. Default behavior is to deny service. The syntax for an entry in the Access Control List is: ACTION SRC_ADDR[/SRC_MASKLEN] [ DST_ADDR[/DST_MASKLEN] ] Where the individual fields are: ACTION = permit-access or deny-access SRC_ADDR = client hostname or dotted IP address SRC_MASKLEN = number of bits in the subnet mask for the source DST_ADDR = server or forwarder hostname or dotted IP address DST_MASKLEN = number of bits in the subnet mask for the target The field separator (FS) is whitespace (space or tab). IMPORTANT NOTE: If the junkbuster is using a forwarder (see below) or a gateway for a particular destination URL, the DST_ADDR that is examined is the address of the forwarder or the gateway and NOT the address of the ultimate target. This is necessary because it may be impossible for the local Junkbuster to determine the address of the ultimate target (that's often what gateways are used for). Here are a few examples to show how the ACL features work: localhost is OK -- no DST_ADDR implies that ALL destination addresses are OK: permit-access localhost A silly example to illustrate permitting any host on the class-C subnet with Junkbuster to go anywhere: permit-access www.junkbusters.com/24 Except deny one particular IP address from using it at all: deny-access ident.junkbusters.com You can also specify an explicit network address and subnet mask. Explicit addresses do not have to be resolved to be used. permit-access 207.153.200.0/24 A subnet mask of 0 matches anything, so the next line permits everyone. permit-access 0.0.0.0/0 Note, you cannot say: permit-access .org to allow all *.org domains. Every IP address listed must resolve fully. An ISP may want to provide a Junkbuster that is accessible by the world and yet restrict use of some of their private content to hosts on its internal network (i.e. its own subscribers). Say, for instance the ISP owns the Class-B IP address block 123.124.0.0 (a 16 bit netmask). This is how they could do it: permit-access 0.0.0.0/0 0.0.0.0/0 # other clients can go anywhere # with the following exceptions: deny-access 0.0.0.0/0 123.124.0.0/16 # block all external requests for # sites on the ISP's network permit 0.0.0.0/0 www.my_isp.com # except for the ISP's main # web site permit 123.124.0.0/16 0.0.0.0/0 # the ISP's clients can go # anywhere Note that if some hostnames are listed with multiple IP addresses, the primary value returned by DNS (via gethostbyname()) is used. Default: Anyone can access the proxy. Forwarding This feature allows chaining of HTTP requests via multiple proxies. It can be used to better protect privacy and confidentiality when accessing specific domains by routing requests to those domains to a special purpose filtering proxy such as lpwa.com. Or to use a caching proxy to speed up browsing. It can also be used in an environment with multiple networks to route requests via multiple gateways allowing transparent access to multiple networks without having to modify browser configurations. Also specified here are SOCKS proxies. Junkbuster SOCKS 4 and SOCKS 4A. The difference is that SOCKS 4A will resolve the target hostname using DNS on the SOCKS server, not our local DNS client. The syntax of each line is: forward target_domain[:port] http_proxy_host[:port] forward-socks4 target_domain[:port] socks_proxy_host[:port] http_proxy_host[:port] forward-socks4a target_domain[:port] socks_proxy_host[:port] http_proxy_host[:port] If http_proxy_host is ., then requests are not forwarded to a HTTP proxy but are made directly to the web servers. Lines are checked in sequence, and the last match wins. There is an implicit line equivalent to the following, which specifies that anything not finding a match on the list is to go out without forwarding or gateway protocol, like so: forward .* . # implicit In the following common configuration, everything goes to Lucent's LPWA, except SSL on port 443 (which it doesn't handle): forward .* lpwa.com:8000 forward :443 . See the FAQ for instructions on how to automate the login procedure for LPWA. Some users have reported difficulties related to LPWA's use of . as the last element of the domain, and have said that this can be fixed with this: forward lpwa. lpwa.com:8000 (NOTE: the syntax for specifying target_domain has changed since the previous paragraph was written -- it will not work now. More information is welcome.) In this fictitious example, everything goes via an ISP's caching proxy, except requests to that ISP: forward .* caching.myisp.net:8000 forward myisp.net . For the @home network, we're told the forwarding configuration is this: forward .* proxy:8080 Also, we're told they insist on getting cookies and JavaScript, so you should add home.com to the cookie file. We consider JavaScript a security risk. Java need not be enabled. In this example direct connections are made to all internal domains, but everything else goes through Lucent's LPWA by way of the company's SOCKS gateway to the Internet. forward-socks4 .* lpwa.com:8000 firewall.my_company.com:1080 forward my_company.com . This is how you could set up a site that always uses SOCKS but no forwarders: forward-socks4a .* . firewall.my_company.com:1080 An advanced example for network administrators: If you have links to multiple ISPs that provide various special content to their subscribers, you can configure forwarding to pass requests to the specific host that's connected to that ISP so that everybody can see all of the content on all of the ISPs. This is a bit tricky, but here's an example: host-a has a PPP connection to isp-a.com. And host-b has a PPP connection to isp-b.com. host-a can run a Junkbuster proxy with forwarding like this: forward .* . forward isp-b.com host-b:8118 host-b can run a Junkbuster proxy with forwarding like this: forward .* . forward isp-a.com host-a:8118 Now, anyone on the Internet (including users on host-a and host-b) can set their browser's proxy to either host-a or host-b and be able to browse the content on isp-a or isp-b. Here's another practical example, for University of Kent at Canterbury students with a network connection in their room, who need to use the University's Squid web cache. forward *. ssbcache.ukc.ac.uk:3128 # Use the proxy, except for: forward .ukc.ac.uk . # Anything on the same domain as us forward * . # Host with no domain specified forward 129.12.*.* . # A dotted IP on our /16 network. forward 127.*.*.* . # Loopback address forward localhost.localdomain . # Loopback address forward www.ukc.mirror.ac.uk . # Specific host If you intend to chain Junkbuster and squid locally, then chain as browser -> squid -> junkbuster is the recommended way. Your squid configuration could then look like this: # Define junkbuster as parent cache cache_peer 127.0.0.1 parent 8118 0 no-query # Define ACL for protocol FTP acl FTP proto FTP # Do not forward ACL FTP to junkbuster always_direct allow FTP # Do not forward ACL CONNECT (https) to junkbuster always_direct allow CONNECT # Forward the rest to junkbuster never_direct allow all Windows GUI Options Junkbuster has a number of options specific to the Windows GUI interface: If activity-animation is set to 1, the Junkbuster icon will animate when Junkbuster is active. To turn off, set to 0. activity-animation 1 If log-messages is set to 1, Junkbuster will log messages to the console window: log-messages 1 If log-buffer-size is set to 1, the size of the log buffer, i.e. the amount of memory used for the log messages displayed in the console window, will be limited to log-max-lines (see below). Warning: Setting this to 0 will result in the buffer to grow infinitely and eat up all your memory! log-buffer-size 1 log-max-lines is the maximum number of lines held in the log buffer. See above. log-max-lines 200 If log-highlight-messages is set to 1, Junkbuster will highlight portions of the log messages with a bold-faced font: log-highlight-messages 1 The font used in the console window: log-font-name Comic Sans MS Font size used in the console window: log-font-size 8 show-on-task-bar controls whether or not Junkbuster will appear as a button on the Task bar when minimized: show-on-task-bar 0 If close-button-minimizes is set to 1, the Windows close button will minimize Junkbuster instead of closing the program (close with the exit option on the File menu). close-button-minimizes 1 The hide-console option is specific to the MS-Win console version of JunkBuster. If this option is used, Junkbuster will disconnect from and hide the command console. #hide-console The Actions File The ijb.action file (formerly actionsfile) is used to define what actions Junkbuster takes, and thus determines how images, cookies and various other aspects of HTTP content and transactions are handled. Images can be anything you want, including ads, banners, or just some obnoxious image that you would rather not see. Cookies can be accepted or rejected, or accepted only during the current browser session (i.e. not written to disk). Changes to ijb.action should be immediately visible to Junkbuster without the need to restart. To determine which actions apply to a request, the URL of the request is compared to all patterns in this file. Every time it matches, the list of applicable actions for the URL is incrementally updated. You can trace this process by visiting http://i.j.b/show-url-info. The actions file can be edited with a browser by loading http://i.j.b/, and then select Edit Actions. There are four types of lines in this file: comments (begin with a # character), actions, aliases and patterns, all of which are explained below, as well as the configuration file syntax that Junkbuster understands. URL Domain and Path Syntax Generally, a pattern has the form <domain>/<path>, where both the <domain> and <path> part are optional. If you only specify a domain part, the / can be left out: www.example.com - is a domain only pattern and will match any request to www.example.com. www.example.com/ - means exactly the same. www.example.com/index.html - matches only the single document /index.html on www.example.com. /index.html - matches the document /index.html, regardless of the domain. index.html - matches nothing, since it would be interpreted as a domain name and there is no top-level domain called .html. The matching of the domain part offers some flexible options: if the domain starts or ends with a dot, it becomes unanchored at that end. For example: .example.com - matches any domain that ENDS in .example.com. www. - matches any domain that STARTS with www. Additionally, there are wild-cards that you can use in the domain names themselves. They work pretty similar to shell wild-cards: * stands for zero or more arbitrary characters, ? stands for any single character. And you can define character classes in square brackets and they can be freely mixed: ad*.example.com - matches adserver.example.com, ads.example.com, etc but not sfads.example.com. *ad*.example.com - matches all of the above, and then some. .?pix.com - matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com, etc. www[1-9a-ez].example.com - matches www1.example.com, www4.example.com, wwwd.example.com, wwwz.example.com, etc., but not wwww.example.com. If Junkbuster was compiled with pcre support (default), Perl compatible regular expressions can be used. See the pcre/docs/ directory or man perlre (also available on http://www.perldoc.com/perl5.6/pod/perlre.html) for details. A brief discussion of regular expressions is in the Appendix. For instance: /.*/advert[0-9]+\.jpe?g - would match a URL from any domain, with any path that includes advert followed immediately by one or more digits, then a . and ending in either jpeg or jpg. So we match example.com/ads/advert2.jpg, and www.example.com/ads/banners/advert39.jpeg, but not www.example.com/ads/banners/advert39.gif (no gifs in the example pattern). Please note that matching in the path is case INSENSITIVE by default, but you can switch to case sensitive at any point in the pattern by using the (?-i) switch: www.example.com/(?-i)PaTtErN.* - will match only documents whose path starts with PaTtErN in exactly this capitalization. Actions Actions are enabled if preceded with a +, and disabled if preceded with a -. Actions are invoked by enclosing the action name in curly braces (e.g. {+some_action}), followed by a list of URLs to which the action applies. There are three classes of actions: Boolean (e.g. +/-block): {+name} # enable this action {-name} # disable this action parameterized (e.g. +/-hide-user-agent): {+name{param}} # enable action and set parameter to param {-name} # disable action Multi-value (e.g. {+/-add-header{Name: value}}, {+/-wafer{name=value}}): {+name{param}} # enable action and add parameter param {-name{param}} # remove the parameter param {-name} # disable this action totally If nothing is specified in this file, no actions are taken. So in this case JunkBuster would just be a normal, non-blocking, non-anonymizing proxy. You must specifically enable the privacy and blocking features you need (although the provided default ijb.action file will give a good starting point). Later defined actions always over-ride earlier ones. For multi-valued actions, the actions are applied in the order they are specified. The list of valid Junkbuster actions are: Add the specified HTTP header, which is not checked for validity. You may specify this many times to specify many different headers: +add-header{Name: value} Block this URL totally. +block De-animate all animated GIF images, i.e. reduce them to their last frame. This will also shrink the images considerably (in bytes, not pixels!). If the option first is given, the first frame of the animation is used as the replacement. If last is given, the last frame of the animation is used instead, which probably makes more sense for most banner animations, but also has the risk of not showing the entire last frame (if it is only a delta to an earlier frame). +deanimate-gifs{last} +deanimate-gifs{first} +downgrade will downgrade HTTP/1.1 client requests to HTTP/1.0 and downgrade the responses as well. Use this action for servers that use HTTP/1.1 protocol features that Junkbuster doesn't handle well yet. HTTP/1.1 is only partially implemented. Default is not to downgrade requests. +downgrade Many sites, like yahoo.com, don't just link to other sites. Instead, they will link to some script on their own server, giving the destination as a parameter, which will then redirect you to the final target. URLs resulting from this scheme typically look like: http://some.place/some_script?http://some.where-else. Sometimes, there are even multiple consecutive redirects encoded in the URL. These redirections via scripts make your web browsing more traceable, since the server from which you follow such a link can see where you go to. Apart from that, valuable bandwidth and time is wasted, while your browser ask the server for one redirect after the other. Plus, it feeds the advertisers. The +fast-redirects option enables interception of these requests by Junkbuster, who will cut off all but the last valid URL in the request and send a local redirect back to your browser without contacting the remote site. +fast-redirects Apply the filters in the section_header section of the re_filterfile file to the site(s). Re_filterfile sections are grouped according to like functionality. +filter{section_header} Filter sections that are pre-defined in the supplied re_filterfile include:
html-annoyances: Get rid of particularly annoying HTML abuse. js-annoyances: Get rid of particularly annoying JavaScript abuse no-poups: Kill all popups in JS and HTML frameset-borders: Give frames a border webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking) no-refresh: Automatic refresh sucks on auto-dialup lines fun: Text replacements for subversive browsing fun! nimda: Remove (virus) Nimda code. banners-by-size: Kill banners by size crude-parental: Kill all web pages that contain the words "sex" or "warez"
Block any existing X-Forwarded-for header, and do not add a new one: +hide-forwarded If the browser sends a From: header containing your e-mail address, this either completely removes the header (block), or changes it to the specified e-mail address. +hide-from{block} +hide-from{spam@sittingduck.xqq} Don't send the Referer: (sic) header to the web site. You can block it, forge a URL to the same server as the request (which is preferred because some sites will not send images otherwise) or set it to a constant string of your choice. +hide-referer{block} +hide-referer{forge} +hide-referer{http://nowhere.com} Alternative spelling of +hide-referer. It has the same parameters, and can be freely mixed with, +hide-referer. (referrer is the correct English spelling, however the HTTP specification has a bug - it requires it to be spelled referer.) +hide-referrer{...} Change the User-Agent: header so web servers can't tell your browser type. Warning! This breaks many web sites. Specify the user-agent value you want. Example, pretend to be using Netscape on Linux: +hide-user-agent{Mozilla (X11; I; Linux 2.0.32 i586)} Treat this URL as an image. This only matters if it's also +blocked, in which case a blocked image can be sent rather than a HTML page. See +image-blocker{} below for the control over what is actually sent. +image Decides what to do with URLs that end up tagged with {+block +image}, e.g an advertizement. There are five options. -image-blocker will send a HTML blocked page, usually resulting in a broken image icon. +image-blocker{logo} will send a JunkBuster logo image. +image-blocker{blank} will send a 1x1 transparent GIF image. And finally, +image-blocker{http://xyz.com} will send a HTTP temporary redirect to the specified image. This has the advantage of the icon being being cached by the browser, which will speed up the display. +image-blocker{pattern} will send a checkboard type pattern, which scales better than the logo (which can get blocky if the browser enlarges it too much). +image-blocker{logo} +image-blocker{blank} +image-blocker{pattern} +image-blocker{http://i.j.b/send-banner} By default (i.e. in the absence of a +limit-connect action), Junkbuster will only allow CONNECT requests to port 443, which is the standard port for https as a precaution. The CONNECT methods exists in HTTP to allow access to secure websites (https:// URLs) through proxies. It works very simply: the proxy connects to the server on the specified port, and then short-circuits its connections to the client and to the remote proxy. This can be a big security hole, since CONNECT-enabled proxies can be abused as TCP relays very easily. If you want to allow CONNECT for more ports than this, or want to forbid CONNECT altogether, you can specify a comma separated list of ports and port ranges (the latter using dashes, with the minimum defaulting to 0 and max to 65K): +limit-connect{443} # This is the default and need no be specified. +limit-connect{80,443} # Ports 80 and 443 are OK. +limit-connect{-3, 7, 20-100, 500-} # Port less than 3, 7, 20 to 100 #and above 500 are OK. +no-compression prevents the website from compressing the data. Some websites do this, which can be a problem for Junkbuster, since +filter, +no-popup and +gif-deanimate will not work on compressed data. This will slow down connections to those websites, though. Default is nocompression is turned on. +nocompression If the website sets cookies, no-cookies-keep will make sure they are erased when you exit and restart your web browser. This makes profiling cookies useless, but won't break sites which require cookies so that you can log in for transactions. Default: on. +no-cookies-keep Prevent the website from reading cookies: +no-cookies-read Prevent the website from setting cookies: +no-cookies-set Filter the website through a built-in filter to disable those obnoxious JavaScript pop-up windows via window.open(), etc. The two alternative spellings are equivalent. +no-popup +no-popups This action only applies if you are using a jarfile for saving cookies. It sends a cookie to every site stating that you do not accept any copyright on cookies sent to you, and asking them not to track you. Of course, this is a (relatively) unique header they could use to track you. +vanilla-wafer This allows you to add an arbitrary cookie. It can be specified multiple times in order to add as many cookies as you like. +wafer{name=value}
The meaning of any of the above is reversed by preceding the action with a -, in place of the +. Some examples: Turn off cookies by default, then allow a few through for specified sites: # Turn off all persistent cookies { +no-cookies-read } { +no-cookies-set } # Allow cookies for this browser session ONLY { +no-cookies-keep } # Exceptions to the above, sites that benefit from persistent cookies { -no-cookies-read } { -no-cookies-set } { -no-cookies-keep } .javasoft.com .sun.com .yahoo.com .msdn.microsoft.com .redhat.com # Alternative way of saying the same thing {-no-cookies-set -no-cookies-read -no-cookies-keep} .sourceforge.net .sf.net Now turn off fast redirects, and then we allow two exceptions: # Turn them off! {+fast-redirects} # Reverse it for these two sites, which don't work right without it. {-fast-redirects} www.ukc.ac.uk/cgi-bin/wac\.cgi\? login.yahoo.com Turn on page filtering according to rules in the defined sections of refilterfile, and make one exception for sourceforge: # Run everything through the filter file, using only the # specified sections: +filter{html-annoyances} +filter{js-annoyances} +filter{no-popups}\ +filter{webbugs} +filter{nimda} +filter{banners-by-size} # Then disable filtering of code from sourceforge! {-filter} .cvs.sourceforge.net Now some URLs that we want blocked, ie we won't see them. Many of these use regular expressions that will expand to match multiple URLs: # Blocklist: {+block} /.*/(.*[-_.])?ads?[0-9]?(/|[-_.].*|\.(gif|jpe?g)) /.*/(.*[-_.])?count(er)?(\.cgi|\.dll|\.exe|[?/]) /.*/(ng)?adclient\.cgi /.*/(plain|live|rotate)[-_.]?ads?/ /.*/(sponsor)s?[0-9]?/ /.*/_?(plain|live)?ads?(-banners)?/ /.*/abanners/ /.*/ad(sdna_image|gifs?)/ /.*/ad(server|stream|juggler)\.(cgi|pl|dll|exe) /.*/adbanners/ /.*/adserver /.*/adstream\.cgi /.*/adv((er)?ts?|ertis(ing|ements?))?/ /.*/banner_?ads/ /.*/banners?/ /.*/banners?\.cgi/ /.*/cgi-bin/centralad/getimage /.*/images/addver\.gif /.*/images/marketing/.*\.(gif|jpe?g) /.*/popupads/ /.*/siteads/ /.*/sponsor.*\.gif /.*/sponsors?[0-9]?/ /.*/advert[0-9]+\.jpg /Media/Images/Adds/ /ad_images/ /adimages/ /.*/ads/ /bannerfarm/ /grafikk/annonse/ /graphics/defaultAd/ /image\.ng/AdType /image\.ng/transactionID /images/.*/.*_anim\.gif # alvin brattli /ip_img/.*\.(gif|jpe?g) /rotateads/ /rotations/ /worldnet/ad\.cgi /cgi-bin/nph-adclick.exe/ /.*/Image/BannerAdvertising/ /.*/ad-bin/ /.*/adlib/server\.cgi /autoads/
Aliases Custom actions, known to Junkbuster as aliases, can be defined by combining other actions. These can in turn be invoked just like the built-in actions. Currently, an alias can contain any character except space, tab, =, { or }. But please use only a- z, 0-9, +, and -. Alias names are not case sensitive, and must be defined before anything else in the ijb.actionfile ! And there can only be one set of aliases defined. Now let's define a few aliases: # Useful customer aliases we can use later. These must come first! {{alias}} +no-cookies = +no-cookies-set +no-cookies-read -no-cookies = -no-cookies-set -no-cookies-read fragile = -block -no-cookies -filter -fast-redirects -hide-referer -no-popups shop = -no-cookies -filter -fast-redirects +imageblock = +block +image #For people who don't like to type too much: ;-) c0 = +no-cookies c1 = -no-cookies c2 = -no-cookies-set +no-cookies-read c3 = +no-cookies-set -no-cookies-read #... etc. Customize to your heart's content. Some examples using our shop and fragile aliases from above: # These sites are very complex and require # minimal interference. {fragile} .office.microsoft.com .windowsupdate.microsoft.com .nytimes.com # Shopping sites - still want to block ads. {shop} .quietpc.com .worldpay.com # for quietpc.com .jungle.com .scan.co.uk # These shops require pop-ups {shop -no-popups} .dabs.com .overclockers.co.uk
The Filter File Any web page can be dynamically modified with the filter file. This modification can be removal, or re-writing, of any web page content, including tags and non-visible content. The default filter file is re_filterfile, located in the config directory. The included example file is divided into sections. Each section begins with the FILTER keyword, followed by the identifier for that section, e.g. FILTER: webbugs. Each section performs a similar type of filtering, such as html-annoyances. This file uses regular expressions to alter or remove any string in the target page. The expressions can only operate on one line at a time. Some examples from the included default re_filterfile: Stop web pages from displaying annoying messages in the status bar by deleting such references: FILTER: html-annoyances # New browser windows should be resizeable and have a location and status # bar. Make it so. # s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig s/scrolling="?(no|0|Auto)"?/scrolling=1/ig s/menubar="?(no|0)"?/menubar=1/ig # The <BLINK> tag was a crime! # s*<blink>|</blink>**ig # Is this evil? # #s/framespacing="?(no|0)"?//ig #s/margin(height|width)=[0-9]*//gi Just for kicks, replace any occurrence of Microsoft with MicroSuck, and have a little fun with topical buzzwords: FILTER: fun s/microsoft(?!.com)/MicroSuck/ig # Buzzword Bingo: # s/industry-leading|cutting-edge|award-winning/<font color=red><b>BINGO!</b></font>/ig Kill those pesky little web-bugs: # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking) FILTER: webbugs s/<img\s+[^>]*?(width|height)\s*=\s*['"]?1\D[^>]*?(width|height)\s*=\s*['"]?1(\D[^>]*?)?>/<!-- Squished WebBug -->/sig Templates When Junkbuster displays one of its internal pages, such as a 404 Not Found error page, it uses the appropriate template. On Linux, BSD, and Unix, these are located in /etc/junkbuster/templates by default. These may be customized, if desired.
Quickstart to Using Junkbuster Install package, then run and enjoy! JunkBuster is typically started by specifying the main configuration file to be used on the command line. Example Unix startup command: # /usr/sbin/junkbuster /etc/junkbuster/config An init script is provided for SuSE and Redhat. For for SuSE: /etc/rc.d/junkbuster start For RedHat: /etc/rc.d/init.d/junkbuster start If no configuration file is specified on the command line, Junkbuster will look for a file named config in the current directory. Except on Win32 where it will try config.txt. If no file is specified on the command line and no default configuration file can be found, Junkbuster will fail to start. Be sure your browser is set to use the proxy which is by default at localhost, port 8118. With Netscape (and Mozilla), this can be set under Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools > Internet Properties -> Connections -> LAN Setting. Then, check Use Proxy and fill in the appropriate info (Address: localhost, Port: 8118). Include if HTTPS proxy support too. The included default configuration files should give a reasonable starting point, though may be somewhat aggressive in blocking junk. You will probably want to keep an eye out for sites that require persistent cookies, and add these to ijb.action as needed. By default, most of these will be accepted only during the current browser session, until you add them to the configuration. If you want the browser to handle this instead, you will need to edit ijb.action and disable this feature. If you use more than one browser, it would make more sense to let Junkbuster handle this. In which case, the browser(s) should be set to accept all cookies. If a particular site shows problems loading properly, try adding it to the {fragile} section of ijb.action. This will turn off most actions for this site. Junkbuster is HTTP/1.1 compliant, but not all 1.1 features are as yet implemented. If browsers that support HTTP/1.1 (like Mozilla or recent versions of I.E.) experience problems, you might try to force HTTP/1.0 compatibility. For Mozilla, look under Edit -> Preferences -> Debug -> Networking. Or set the +downgrade config option in ijb.action. After running Junkbuster for a while, you can start to fine tune the configuration to suit your personal, or site, preferences and requirements. There are many, many aspects that can be customized. Actions (as specified in ijb.action) can be adjusted by pointing your browser to http://i.j.b/, and then follow the link to edit the actions list. (This is an internal page and does not require Internet access.) In fact, various aspects of Junkbuster configuration can be viewed from this page, including current configuration parameters, source code version numbers, the browser's request headers, and actions that apply to a given URL. In addition to the ijb.action file editor mentioned above, Junkbuster can also be turned on and off from this page. If you encounter problems, please verify it is a Junkbuster bug, by disabling Junkbuster, and then trying the same page. Also, try another browser if possible to eliminate browser or site problems. Before reporting it as a bug, see if there is not a configuration option that is enabled that is causing the page not to load. You can then add an exception for that page or site. If a bug, please report it to the developers (see below). Command Line Options JunkBuster may be invoked with the following command-line options: --version Print version info and exit, Unix only. --help Print a short usage info and exit, Unix only. --no-daemon Don't become a daemon, i.e. don't fork and become process group leader, don't detach from controlling tty. Unix only. --pidfile FILE On startup, write the process ID to FILE. Delete the FILE on exit. Failiure to create or delete the FILE is non-fatal. If no FILE option is given, no PID file will be used. Unix only. --user USER[.GROUP] After (optionally) writing the PID file, assume the user ID of USER, and if included the GID of GROUP. Exit if the privileges are not sufficient to do so. Unix only. configfile If no configfile is included on the command line, JunkBuster will look for a file named config in the current directory (except on Win32 where it will look for config.txt instead). Specify full path to avoid confusion. Contacting the Developers, Bug Reporting and Feature Requests We value your feedback. However, to provide you with the best support, please note: Use the Sourceforge support forum to get help. Submit bugs only thru our Sourceforge bug forum. Make sure that the bug has not already been submitted. Please try to verify that it is a Junkbuster bug, and not a browser or site bug first. If you are using your own custom configuration, please try the stock configs to see if the problem is a configuration related bug. And if not using the latest development snapshot, please try the latest one. Or even better, CVS sources. Submit feature requests only thru our Sourceforge feature request forum. For any other issues, feel free to use the mailing lists. Anyone interested in actively participating in development and related discussions can join the appropriate mailing list here. Archives are available here too. Copyright and History License Internet Junkbuster is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details, which is available from the Free Software Foundation, Inc, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. History Junkbuster was originally written by Anonymous Coders and Junkbuster's Corporation, and was released as free open-source software under the GNU GPL. Stefan Waldherr made many improvements, and started the SourceForge project to rekindle development. There are now several active developers contributing. The last stable release was v2.0.2, which has now grown whiskers ;-). See also   http://sourceforge.net/projects/ijbswa   http://ijbswa.sourceforge.net/   http://i.j.b/   http://www.junkbusters.com/ht/en/cookies.html   http://www.waldherr.org/junkbuster/   http://privacy.net/analyze/  http://www.squid-cache.org/ Appendix Regular Expressions Junkbuster can use regular expressions in various config files. Assuming support for pcre (Perl Compatible Regular Expressions) is compiled in, which is the default. Such configuration directives do not require regular expressions, but they can be used to increase flexibility by matching a pattern with wild-cards against URLs. If you are reading this, you probably don't understand what regular expressions are, or what they can do. So this will be a very brief introduction only. A full explanation would require a book ;-) Regular expressions is a way of matching one character expression against another to see if it matches or not. One of the expressions is a literal string of readable characters (letter, numbers, etc), and the other is a complex string of literal characters combined with wild-cards, and other special characters, called meta-characters. The meta-characters have special meanings and are used to build the complex pattern to be matched against. Perl Compatible Regular Expressions is an enhanced form of the regular expression language with backward compatibility. To make a simple analogy, we do something similar when we use wild-card characters when listing files with the dir command in DOS. *.* matches all filenames. The special character here is the asterisk which matches any and all characters. We can be more specific and use ? to match just individual characters. So dir file?.text would match file1.txt, file2.txt, etc. We are pattern matching, using a similar technique to regular expressions! Regular expressions do essentially the same thing, but are much, much more powerful. There are many more special characters and ways of building complex patterns however. Let's look at a few of the common ones, and then some examples: . - Matches any single character, e.g. a, A, 4, :, or @. ? - The preceding character or expression is matched ZERO or ONE times. Either/or. + - The preceding character or expression is matched ONE or MORE times. * - The preceding character or expression is matched ZERO or MORE times. \ - The escape character denotes that the following character should be taken literally. This is used where one of the special characters (e.g. .) needs to be taken literally and not as a special meta-character. [] - Characters enclosed in brackets will be matched if any of the enclosed characters are encountered. () - parentheses are used to group a sub-expression, or multiple sub-expressions. | - The bar character works like an or conditional statement. A match is successful if the sub-expression on either side of | matches. s/string1/string2/g - This is used to rewrite strings of text. string1 is replaced by string2 in this example. These are just some of the ones you are likely to use when matching URLs with Junkbuster, and is a long way from a definitive list. This is enough to get us started with a few simple examples which may be more illuminating: /.*/banners/.* - A simple example that uses the common combination of . and * to denote any character, zero or more times. In other words, any string at all. So we start with a literal forward slash, then our regular expression pattern (.*) another literal forward slash, the string banners, another forward slash, and lastly another .*. We are building a directory path here. This will match any file with the path that has a directory named banners in it. The .* matches any characters, and this could conceivably be more forward slashes, so it might expand into a much longer looking path. For example, this could match: /eye/hate/spammers/banners/annoy_me_please.gif, or just /banners/annoying.html, or almost an infinite number of other possible combinations, just so it has banners in the path somewhere. A now something a little more complex: /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward slashes again (/), so we are building another expression that is a file path statement. We have another .*, so we are matching against any conceivable sub-path, just so it matches our expression. The only true literal that must match our pattern is adv, together with the forward slashes. What comes after the adv string is the interesting part. Remember the ? means the preceding expression (either a literal character or anything grouped with (...) in this case) can exist or not, since this means either zero or one match. So ((er)?ts?|ertis(ing|ements?)) is optional, as are the individual sub-expressions: (er), (ing|ements?), and the s. The | means or. We have two of those. For instance, (ing|ements?), can expand to match either ing OR ements?. What is being done here, is an attempt at matching as many variations of advertisement, and similar, as possible. So this would expand to match just adv, or advert, or adverts, or advertising, or advertisement, or advertisements. You get the idea. But it would not match advertizements (with a z). We could fix that by changing our regular expression to: /.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/, which would then match either spelling. /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward slashes. Anything in the square brackets [] can be matched. This is using 0-9 as a shorthand expression to mean any digit one through nine. It is the same as saying 0123456789. So any digit matches. The + means one or more of the preceding expression must be included. The preceding expression here is what is in the square brackets -- in this case, any digit one through nine. Then, at the end, we have a grouping: (gif|jpe?g). This includes a |, so this needs to match the expression on either side of that bar character also. A simple gif on one side, and the other side will in turn match either jpeg or jpg, since the ? means the letter e is optional and can be matched once or not at all. So we are building an expression here to match image GIF or JPEG type image file. It must include the literal string advert, then one or more digits, and a . (which is now a literal, and not a special character, since it is escaped with \), and lastly either gif, or jpeg, or jpg. Some possible matches would include: //advert1.jpg, /nasty/ads/advert1234.gif, /banners/from/hell/advert99.jpg. It would not match advert1.gif (no leading slash), or /adverts232.jpg (the expression does not include an s), or /advert1.jsp (jsp is not in the expression anywhere). s/microsoft(?!.com)/MicroSuck/i - This is a substitution. MicroSuck will replace any occurrence of microsoft. The i at the end of the expression means ignore case. The (?!.com) means the match should fail if microsoft is followed by .com. In other words, this acts like a NOT modifier. In case this is a hyperlink, we don't want to break it ;-). We are barely scratching the surface of regular expressions here so that you can understand the default Junkbuster configuration files, and maybe use this knowledge to customize your own installation. There is much, much more that can be done with regular expressions. Now that you know enough to get started, you can learn more on your own :/ More reading on Perl Compatible Regular expressions: http://www.perldoc.com/perl5.6/pod/perlre.html JunkBuster's Internal Pages Since JunkBuster proxies each requested web page, it is easy for JunkBuster to trap certain URLs. In this way, we can talk directly to JunkBuster, and see how it is configured, see how our rules are being applied, change these rules and other configuration options, and even turn JunkBuster's filtering off, all with a web browser. The URLs listed below are the special ones that allow direct access to JunkBuster. Of course, JunkBuster must be running to access these. If not, you will get a friendly error message. Junkbuster main page:
http://ijbswa.sourceforge.net/config/
Alternately, this may be reached at http://i.j.b/, but this variation may not work as reliably as the above in some configurations.
Show information about the current configuration:
http://ijbswa.sourceforge.net/config/show-status
Show the source code version numbers:
http://ijbswa.sourceforge.net/config/show-version
Show the client's request headers:
http://ijbswa.sourceforge.net/config/show-request
Show which actions apply to a URL and why:
http://ijbswa.sourceforge.net/config/show-url-info
Toggle JunkBuster on or off:
http://ijbswa.sourceforge.net/config/toggle
Short cuts. Turn off, then on:
http://ijbswa.sourceforge.net/config/toggle?set=disable
http://ijbswa.sourceforge.net/config/toggle?set=enable
Edit the actions list file:
http://ijbswa.sourceforge.net/config/edit-actions
These may be bookmarked for quick reference.