+ * Revision 1.97 2007/04/09 18:11:35 fabiankeil
+ * Don't mistake VC++'s _snprintf() for a snprintf() replacement.
+ *
+ * Revision 1.96 2007/03/08 17:41:05 fabiankeil
+ * Use sizeof() more often.
+ *
+ * Revision 1.95 2007/02/10 17:01:37 fabiankeil
+ * Don't overlook map result for the forwarding-type.
+ *
+ * Revision 1.94 2007/02/08 19:44:49 fabiankeil
+ * Use a transparent background for the PNG replacement pattern.
+ *
+ * Revision 1.93 2007/02/07 10:45:22 fabiankeil
+ * - Save the reason for generating http_responses.
+ * - Fix --disable-toggle (again).
+ * - Use TBL birthday hack for 403 responses as well.
+ * - Uglify the @menu@ again to fix JavaScript
+ * errors on the "blocked" template.
+ * - Escape an ampersand in cgi_error_unknown().
+ *
+ * Revision 1.92 2007/01/28 13:41:17 fabiankeil
+ * - Add HEAD support to finish_http_response.
+ * - Add error favicon to internal HTML error messages.
+ *
+ * Revision 1.91 2007/01/27 13:09:16 fabiankeil
+ * Add new config option "templdir" to
+ * change the templates directory.
+ *
+ * Revision 1.90 2007/01/25 13:47:26 fabiankeil
+ * Added "forwarding-failed" template support for error_response().
+ *
+ * Revision 1.89 2007/01/23 15:51:16 fabiankeil
+ * Add favicon delivery functions.
+ *
+ * Revision 1.88 2007/01/23 13:14:32 fabiankeil
+ * - Map variables that aren't guaranteed to be
+ * pure ASCII html_encoded.
+ * - Use CGI_PREFIX to generate URL for user manual
+ * CGI page to make sure CGI_SITE_2_PATH is included.
+ *
+ * Revision 1.87 2007/01/22 15:34:13 fabiankeil
+ * - "Protect" against a rather lame JavaScript-based
+ * Privoxy detection "attack" and check the referrer
+ * before delivering the CGI style sheet.
+ * - Move referrer check for unsafe CGI pages into
+ * referrer_is_safe() and log the result.
+ * - Map @url@ in cgi-error-disabled page.
+ * It's required for the "go there anyway" link.
+ * - Mark *csp as immutable for grep_cgi_referrer().
+ *
+ * Revision 1.86 2007/01/09 11:54:26 fabiankeil
+ * Fix strdup() error handling in cgi_error_unknown()
+ * and cgi_error_no_template(). Reported by Markus Elfring.
+ *
+ * Revision 1.85 2007/01/05 14:19:02 fabiankeil
+ * Handle pcrs_execute() errors in template_fill() properly.
+ *
+ * Revision 1.84 2006/12/28 17:54:22 fabiankeil
+ * Fixed gcc43 conversion warnings and replaced sprintf
+ * calls with snprintf to give OpenBSD's gcc one less reason
+ * to complain.
+ *
+ * Revision 1.83 2006/12/17 19:35:19 fabiankeil
+ * Escape ampersand in Privoxy menu.
+ *
+ * Revision 1.82 2006/12/17 17:53:39 fabiankeil
+ * Suppress the toggle link if remote toggling is disabled.
+ *
+ * Revision 1.81 2006/12/09 13:49:16 fabiankeil
+ * Fix configure option --disable-toggle.
+ * Thanks to Peter Thoenen for reporting this.
+ *
+ * Revision 1.80 2006/12/08 14:45:32 fabiankeil
+ * Don't lose the FORCE_PREFIX in case of
+ * connection problems. Fixes #612235.
+ *
+ * Revision 1.79 2006/11/13 19:05:50 fabiankeil
+ * Make pthread mutex locking more generic. Instead of
+ * checking for OSX and OpenBSD, check for FEATURE_PTHREAD
+ * and use mutex locking unless there is an _r function
+ * available. Better safe than sorry.
+ *
+ * Fixes "./configure --disable-pthread" and should result
+ * in less threading-related problems on pthread-using platforms,
+ * but it still doesn't fix BR#1122404.
+ *
+ * Revision 1.78 2006/09/21 19:22:07 fabiankeil
+ * Use CGI_PREFIX to check the referrer.
+ * The check for "http://config.privoxy.org/" fails
+ * if the user modified CGI_SITE_2_HOST.
+ *
+ * Revision 1.77 2006/09/21 15:17:23 fabiankeil
+ * Adjusted headers for Privoxy's cgi responses:
+ * Don't set Last-Modified, Expires and Cache-Control
+ * headers for redirects; always set "Connection: close".
+ *
+ * Revision 1.76 2006/09/07 14:06:38 fabiankeil
+ * Only predate the Last-Modified header for cgi responses
+ * that are delivered with status code 404 or 503.
+ *
+ * Revision 1.75 2006/09/07 11:56:39 fabiankeil
+ * Mark cgi_send_user_manual as harmless,
+ * to fix the access denied problem Hal spotted.
+ * The manual has no secret content, therefore we
+ * don't have to care about "secure" referrers.
+ *
+ * Revision 1.74 2006/09/06 18:45:03 fabiankeil
+ * Incorporate modified version of Roland Rosenfeld's patch to
+ * optionally access the user-manual via Privoxy. Closes patch 679075.
+ *
+ * Formatting changed to Privoxy style, added call to
+ * cgi_error_no_template if the requested file doesn't
+ * exist and modified check whether or not Privoxy itself
+ * should serve the manual. Should work cross-platform now.
+ *
+ * Revision 1.73 2006/08/03 02:46:41 david__schmidt
+ * Incorporate Fabian Keil's patch work:\rhttp://www.fabiankeil.de/sourcecode/privoxy/
+ *
+ * Revision 1.72 2006/07/18 14:48:45 david__schmidt
+ * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
+ * with what was really the latest development (the v_3_0_branch branch)
+ *
+ * Revision 1.70.2.13 2004/02/17 13:30:23 oes
+ * Moved cgi_error_disabled() from cgiedit.c to
+ * cgi.c to re-enable build with --disable-editor.
+ * Fixes Bug #892744. Thanks to Matthew Fischer
+ * for spotting.
+ *
+ * Revision 1.70.2.12 2003/12/17 16:33:16 oes
+ * - Added new function cgi_redirect to handle creation of
+ * HTTP redirect messages formerly repeated in the code.
+ * - Send cgi_error_disabled instead of cgi_error_404 when
+ * referrer check fails
+ * - Dynamic content now gets Expires header field with date
+ * in the past
+ *
+ * Revision 1.70.2.11 2003/10/23 12:29:26 oes
+ * Bugfix: Transparent PNG was not transparent. Thanks to
+ * Dan Razzell of Starfish Systems for notice and new PNG.
+ *
+ * Revision 1.70.2.10 2003/06/06 07:54:25 oes
+ * Security fix: dspatch_known_cgi no longer considers an empty
+ * referrer safe for critical CGIs, since malicious links could
+ * reside on https:// locations which browsers don't advertize as
+ * referrers. Closes bug #749916, thanks to Jeff Epler for the
+ * hint. Goodbye One-Click[tm] toggling :-(
+ *
+ * Revision 1.70.2.9 2003/05/08 15:11:31 oes
+ * Nit
+ *
+ * Revision 1.70.2.8 2003/04/29 13:33:51 oes
+ * Killed a compiler warning on OSX
+ *
+ * Revision 1.70.2.7 2003/04/03 13:50:58 oes
+ * - Don't call cgi_error_disabled ifndef FEATURE_CGI_EDIT_ACTIONS
+ * (fixes bug #710056)
+ * - Show toggle info only if we have it
+ *
+ * Revision 1.70.2.6 2003/03/12 01:26:25 david__schmidt
+ * Move declaration of struct tm dummy outside of a control block so it is
+ * accessible later on during snprintf in get_http_time.
+ *
+ * Revision 1.70.2.5 2003/03/11 11:53:58 oes
+ * Cosmetic: Renamed cryptic variable
+ *
+ * Revision 1.70.2.4 2003/03/07 03:41:03 david__schmidt
+ * Wrapping all *_r functions (the non-_r versions of them) with mutex semaphores for OSX. Hopefully this will take care of all of those pesky crash reports.
+ *
+ * Revision 1.70.2.3 2002/11/28 18:14:32 oes
+ * Disable access to critical CGIs via untrusted referrers.
+ * This prevents users from being tricked by malicious websites
+ * into making unintentional configuration changes:
+ *
+ * - Added flag to each cgi_dispatcher that allows or denies
+ * external linking
+ * - Introduced proviorical function that greps for the
+ * referrer header before regular header parsing happens
+ * - Added safety check to dispatch_known_cgi. CGI is called
+ * if (cgi harmless || no referrer || we are referrer).
+ * Else a) toggle calls are modified not to change status and
+ * b) all other calls are denied.
+ *
+ * Revision 1.70.2.2 2002/11/12 16:20:37 oes
+ * Added missing #ifdef FEATURE_TOGGLE around g_bToggleIJB; fixes bug #636651
+ *
+ * Revision 1.70.2.1 2002/08/05 11:17:46 oes
+ * Fixed Bug #587820, i.e. added workaround for IE bug that includes fragment identifier in (cgi) query
+ *
+ * Revision 1.70 2002/05/19 11:33:20 jongfoster
+ * If a CGI error was not handled, and propogated back to
+ * dispatch_known_cgi(), then it was assumed to be "out of memory".
+ * This gave a very misleading error message.
+ *
+ * Now other errors will cause a simple message giving the error
+ * number and asking the user to report a bug.
+ *
+ * Bug report:
+ * http://sourceforge.net/tracker/index.php?func=detail
+ * &aid=557905&group_id=11118&atid=111118
+ *
+ * Revision 1.69 2002/05/14 21:28:40 oes
+ * - Fixed add_help_link to link to the (now split) actions
+ * part of the config chapter
+ * - Renamed helplink export to actions-help-prefix
+ *
+ * Revision 1.68 2002/05/12 21:36:29 jongfoster
+ * Correcting function comments
+ *
+ * Revision 1.67 2002/04/30 12:02:07 oes
+ * Nit: updated a comment
+ *
+ * Revision 1.66 2002/04/26 18:32:57 jongfoster
+ * Fixing a memory leak on error
+ *
+ * Revision 1.65 2002/04/26 12:53:51 oes
+ * - New function add_help_link
+ * - default_exports now exports links to the user manual
+ * and a prefix for links into the config chapter
+ *
+ * Revision 1.64 2002/04/24 02:17:21 oes
+ * - Better descriptions for CGIs
+ * - Hide edit-actions, more shortcuts
+ * - Moved get_char_param, get_string_param and get_number_param here
+ * from cgiedit.c
+ *
+ * Revision 1.63 2002/04/15 19:06:43 jongfoster
+ * Typos
+ *
+ * Revision 1.62 2002/04/10 19:59:46 jongfoster
+ * Fixes to #include in templates:
+ * - Didn't close main file if loading an included template fails.
+ * - I'm paranoid and want to disallow "#include /etc/passwd".
+ *
+ * Revision 1.61 2002/04/10 13:37:48 oes
+ * Made templates modular: template_load now recursive with max depth 1
+ *
+ * Revision 1.60 2002/04/08 20:50:25 swa
+ * fixed JB spelling
+ *
+ * Revision 1.59 2002/04/05 15:51:51 oes
+ * - added send-stylesheet CGI
+ * - bugfix: error-pages now get correct request protocol
+ * - fixed
+ * - kludged CGI descriptions and menu not to break JS syntax
+ *
+ * Revision 1.58 2002/03/29 03:33:13 david__schmidt
+ * Fix Mac OSX compiler warnings
+ *
+ * Revision 1.57 2002/03/26 22:29:54 swa
+ * we have a new homepage!
+ *
+ * Revision 1.56 2002/03/24 17:50:46 jongfoster
+ * Fixing compile error if actions file editor disabled
+ *
+ * Revision 1.55 2002/03/24 16:55:06 oes
+ * Making GIF checkerboard transparent
+ *
+ * Revision 1.54 2002/03/24 16:18:15 jongfoster
+ * Removing old logo
+ *
+ * Revision 1.53 2002/03/24 16:06:00 oes
+ * Correct transparency for checkerboard PNG. Thanks, Magnus!
+ *
+ * Revision 1.52 2002/03/24 15:23:33 jongfoster
+ * Name changes
+ *
+ * Revision 1.51 2002/03/24 13:25:43 swa
+ * name change related issues
+ *
+ * Revision 1.50 2002/03/16 23:54:06 jongfoster
+ * Adding graceful termination feature, to help look for memory leaks.
+ * If you enable this (which, by design, has to be done by hand
+ * editing config.h) and then go to http://i.j.b/die, then the program
+ * will exit cleanly after the *next* request. It should free all the
+ * memory that was used.
+ *
+ * Revision 1.49 2002/03/13 00:27:04 jongfoster
+ * Killing warnings
+ *
+ * Revision 1.48 2002/03/08 17:47:07 jongfoster
+ * Adding comments
+ *
+ * Revision 1.47 2002/03/08 16:41:33 oes
+ * Added GIF images again
+ *
+ * Revision 1.46 2002/03/07 03:48:38 oes
+ * - Changed built-in images from GIF to PNG
+ * (with regard to Unisys patent issue)
+ * - Added a 4x4 pattern PNG which is less intrusive
+ * than the logo but also clearly marks the deleted banners
+ *
+ * Revision 1.45 2002/03/06 22:54:35 jongfoster
+ * Automated function-comment nitpicking.
+ *
+ * Revision 1.44 2002/03/05 22:43:45 david__schmidt
+ * - Better error reporting on OS/2
+ * - Fix double-slash comment (oops)
+ *
+ * Revision 1.43 2002/03/05 21:33:45 david__schmidt
+ * - Re-enable OS/2 building after new parms were added
+ * - Fix false out of memory report when resolving CGI templates when no IP
+ * address is available of failed attempt (a la no such domain)
+ *
+ * Revision 1.42 2002/01/21 00:33:20 jongfoster
+ * Replacing strsav() with the safer string_append() or string_join().
+ * Adding map_block_keep() to save a few bytes in the edit-actions-list HTML.
+ * Adding missing html_encode() to error message generators.
+ * Adding edit-actions-section-swap and many "shortcuts" to the list of CGIs.
+ *
+ * Revision 1.41 2002/01/17 20:56:22 jongfoster
+ * Replacing hard references to the URL of the config interface
+ * with #defines from project.h
+ *
+ * Revision 1.40 2002/01/09 14:26:46 oes
+ * Added support for thread-safe gmtime_r call.
+ *
+ * Revision 1.39 2001/11/16 00:48:13 jongfoster
+ * Fixing a compiler warning
+ *
+ * Revision 1.38 2001/11/13 00:31:21 jongfoster
+ * - Adding new CGIs for use by non-JavaScript browsers:
+ * edit-actions-url-form
+ * edit-actions-add-url-form
+ * edit-actions-remove-url-form
+ * - Fixing make_menu()'s HTML generation - it now quotes the href parameter.
+ * - Fixing || bug.
+ *
+ * Revision 1.37 2001/11/01 14:28:47 david__schmidt
+ * Show enablement/disablement status in almost all templates.
+ * There is a little trickiness here: apparent recursive resolution of
+ * @if-enabled-then@ caused the toggle template to show status out-of-phase with
+ * the actual enablement status. So a similar construct,
+ * @if-enabled-display-then@, is used to resolve the status display on non-'toggle'
+ * templates.
+ *
+ * Revision 1.36 2001/10/26 17:33:27 oes
+ * marginal bugfix
+ *
+ * Revision 1.35 2001/10/23 21:48:19 jongfoster
+ * Cleaning up error handling in CGI functions - they now send back
+ * a HTML error page and should never cause a FATAL error. (Fixes one
+ * potential source of "denial of service" attacks).
+ *
+ * CGI actions file editor that works and is actually useful.
+ *
+ * Ability to toggle Junkbuster remotely using a CGI call.
+ *
+ * You can turn off both the above features in the main configuration
+ * file, e.g. if you are running a multi-user proxy.
+ *
+ * Revision 1.34 2001/10/18 22:22:09 david__schmidt
+ * Only show "Local support" on templates conditionally:
+ * - if either 'admin-address' or 'proxy-info-url' are uncommented in config
+ * - if not, no Local support section appears
+ *
+ * Revision 1.33 2001/10/14 22:28:41 jongfoster
+ * Fixing stupid typo.
+ *
+ * Revision 1.32 2001/10/14 22:20:18 jongfoster
+ * - Changes to CGI dispatching method to match CGI names exactly,
+ * rather than doing a prefix match.
+ * - No longer need to count the length of the CGI handler names by hand.
+ * - Adding new handler for 404 error when disptching a CGI, if none of
+ * the handlers match.
+ * - Adding new handlers for CGI actionsfile editor.
+ *
+ * Revision 1.31 2001/10/10 10:56:39 oes
+ * Failiure to load template now fatal. Before, the user got a hard-to-understand assertion failure from cgi.c
+ *
+ * Revision 1.30 2001/10/02 15:30:57 oes
+ * Introduced show-request cgi
+ *
+ * Revision 1.29 2001/09/20 15:47:44 steudten
+ *
+ * Fix BUG: Modify int size to size_t size in fill_template()
+ * - removes big trouble on machines where sizeof(int) != sizeof(size_t).
+ *
+ * Revision 1.28 2001/09/19 18:00:37 oes
+ * - Deletef time() FIXME (Can't fail under Linux either, if
+ * the argument is guaranteed to be in out address space,
+ * which it is.)
+ * - Fixed comments
+ * - Pointer notation cosmetics
+ * - Fixed a minor bug in template_fill(): Failiure of
+ * pcrs_execute() now secure.
+ *
+ * Revision 1.27 2001/09/16 17:08:54 jongfoster
+ * Moving simple CGI functions from cgi.c to new file cgisimple.c
+ *
+ * Revision 1.26 2001/09/16 15:47:37 jongfoster
+ * First version of CGI-based edit interface. This is very much a
+ * work-in-progress, and you can't actually use it to edit anything
+ * yet. You must #define FEATURE_CGI_EDIT_ACTIONS for these changes
+ * to have any effect.
+ *
+ * Revision 1.25 2001/09/16 15:02:35 jongfoster
+ * Adding i.j.b/robots.txt.
+ * Inlining add_stats() since it's only ever called from one place.
+ *
+ * Revision 1.24 2001/09/16 11:38:01 jongfoster
+ * Splitting fill_template() into 2 functions:
+ * template_load() loads the file
+ * template_fill() performs the PCRS regexps.
+ * This is because the CGI edit interface has a "table row"
+ * template which is used many times in the page - this
+ * change means it's only loaded from disk once.
+ *
+ * Revision 1.23 2001/09/16 11:16:05 jongfoster
+ * Better error handling in dispatch_cgi() and parse_cgi_parameters()
+ *
+ * Revision 1.22 2001/09/16 11:00:10 jongfoster
+ * New function alloc_http_response, for symmetry with free_http_response
+ *