1 const char filters_rcs[] = "$Id: filters.c,v 1.65 2006/09/21 12:54:43 fabiankeil Exp $";
2 /*********************************************************************
4 * File : $Source: /cvsroot/ijbswa/current/filters.c,v $
6 * Purpose : Declares functions to parse/crunch headers and pages.
7 * Functions declared include:
8 * `acl_addr', `add_stats', `block_acl', `block_imageurl',
9 * `block_url', `url_actions', `domain_split',
10 * `filter_popups', `forward_url', 'redirect_url',
11 * `ij_untrusted_url', `intercept_url', `pcrs_filter_respose',
12 * `ijb_send_banner', `trust_url', `gif_deanimate_response',
13 * `jpeg_inspect_response'
15 * Copyright : Written by and Copyright (C) 2001, 2004 the SourceForge
16 * Privoxy team. http://www.privoxy.org/
18 * Based on the Internet Junkbuster originally written
19 * by and Copyright (C) 1997 Anonymous Coders and
20 * Junkbusters Corporation. http://www.junkbusters.com
22 * This program is free software; you can redistribute it
23 * and/or modify it under the terms of the GNU General
24 * Public License as published by the Free Software
25 * Foundation; either version 2 of the License, or (at
26 * your option) any later version.
28 * This program is distributed in the hope that it will
29 * be useful, but WITHOUT ANY WARRANTY; without even the
30 * implied warranty of MERCHANTABILITY or FITNESS FOR A
31 * PARTICULAR PURPOSE. See the GNU General Public
32 * License for more details.
34 * The GNU General Public License should be included with
35 * this file. If not, you can view it at
36 * http://www.gnu.org/copyleft/gpl.html
37 * or write to the Free Software Foundation, Inc., 59
38 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
42 * Revision 1.65 2006/09/21 12:54:43 fabiankeil
43 * Fix +redirect{}. Didn't work with -fast-redirects.
45 * Revision 1.64 2006/08/31 10:55:49 fabiankeil
46 * Block requests for untrusted URLs with status
47 * code 403 instead of 200.
49 * Revision 1.63 2006/08/31 10:11:28 fabiankeil
50 * Don't free p which is still in use and will be later
51 * freed by free_map(). Don't claim the referrer is unknown
52 * when the client didn't set one.
54 * Revision 1.62 2006/08/14 00:27:47 david__schmidt
55 * Feature request 595948: Re-Filter logging in single line
57 * Revision 1.61 2006/08/03 02:46:41 david__schmidt
58 * Incorporate Fabian Keil's patch work:
\rhttp://www.fabiankeil.de/sourcecode/privoxy/
60 * Revision 1.60 2006/07/18 14:48:46 david__schmidt
61 * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
62 * with what was really the latest development (the v_3_0_branch branch)
64 * Revision 1.58.2.9 2006/01/29 23:10:56 david__schmidt
65 * Multiple filter file support
67 * Revision 1.58.2.8 2005/05/07 21:50:55 david__schmidt
68 * A few memory leaks plugged (mostly on error paths)
70 * Revision 1.58.2.7 2004/10/03 12:53:32 david__schmidt
71 * Add the ability to check jpeg images for invalid
72 * lengths of comment blocks. Defensive strategy
73 * against the exploit:
74 * Microsoft Security Bulletin MS04-028
75 * Buffer Overrun in JPEG Processing (GDI+) Could
76 * Allow Code Execution (833987)
77 * Enabled with +inspect-jpegs in actions files.
79 * Revision 1.58.2.6 2003/12/06 22:18:27 gliptak
80 * Correcting compile problem with FEATURE_IMAGE_BLOCKING
82 * Revision 1.58.2.5 2003/11/11 13:10:31 oes
83 * Fixed bug #839859: "See why" link URL now gets url-encoded.
85 * Revision 1.58.2.4 2003/02/28 12:52:45 oes
88 * Revision 1.58.2.3 2002/09/25 14:51:51 oes
89 * Added basic support for OPTIONS and TRACE HTTP methods:
90 * New function direct_response which handles OPTIONS and
91 * TRACE requests whose Max-Forwards header field is zero.
93 * Revision 1.58.2.2 2002/08/01 17:18:28 oes
94 * Fixed BR 537651 / SR 579724 (MSIE image detect improper for IE/Mac)
96 * Revision 1.58.2.1 2002/07/26 15:18:53 oes
97 * - Bugfix: Executing a filters without jobs no longer results in
98 * turing off *all* filters.
99 * - Security fix: Malicious web servers can't cause a seg fault
100 * through bogus chunk sizes anymore
102 * Revision 1.58 2002/04/24 02:11:17 oes
103 * Jon's multiple AF patch: url_actions now evaluates rules
106 * Revision 1.57 2002/04/08 20:38:34 swa
109 * Revision 1.56 2002/04/05 15:51:24 oes
110 * - bugfix: error-pages now get correct request protocol
111 * - fix for invalid HTML in trust info
113 * Revision 1.55 2002/04/02 16:13:51 oes
114 * Fix: No "Go there anyway" for SSL
116 * Revision 1.54 2002/04/02 14:55:56 oes
117 * Bugfix: is_untrusted_url() now depends on FEATURE_TRUST, not FEATURE_COOKIE_JAR
119 * Revision 1.53 2002/03/26 22:29:54 swa
120 * we have a new homepage!
122 * Revision 1.52 2002/03/24 16:35:57 jongfoster
125 * Revision 1.51 2002/03/24 15:23:33 jongfoster
128 * Revision 1.50 2002/03/24 13:25:43 swa
129 * name change related issues
131 * Revision 1.49 2002/03/16 20:29:14 oes
134 * Revision 1.48 2002/03/13 20:25:34 oes
135 * Better logging for content filters
137 * Revision 1.47 2002/03/13 00:30:52 jongfoster
139 * Added option of always sending redirect for imageblock,
140 * currently disabled with #if 0.
142 * Revision 1.46 2002/03/12 01:42:49 oes
143 * Introduced modular filters
145 * Revision 1.45 2002/03/08 16:47:50 oes
146 * Added choice beween GIF and PNG built-in images
148 * Revision 1.44 2002/03/07 03:49:31 oes
149 * - Fixed compiler warnings etc
150 * - Changed built-in images from GIF to PNG
151 * (with regard to Unisys patent issue)
152 * - Added a 4x4 pattern PNG which is less intrusive
153 * than the logo but also clearly marks the deleted banners
155 * Revision 1.43 2002/01/22 23:51:59 jongfoster
156 * Replacing strsav() with the safer string_append().
158 * Adding missing html_encode() to error message generators. Where encoded
159 * and unencoded versions of a string were provided, removing the unencoded
162 * Revision 1.42 2002/01/17 21:00:32 jongfoster
163 * Moving all our URL and URL pattern parsing code to urlmatch.c.
165 * Using a single, simple url_match(pattern,url) function - rather than
166 * the 3-line match routine which was repeated all over the place.
168 * Renaming free_url to free_url_spec, since it frees a struct url_spec.
170 * Using parse_http_url() to parse URLs without faking a HTTP
171 * request line for parse_http_request().
173 * Revision 1.41 2001/11/13 00:14:07 jongfoster
174 * Fixing stupid bug now I've figured out what || means.
175 * (It always returns 0 or 1, not one of it's paramaters.)
177 * Revision 1.40 2001/10/26 17:37:55 oes
178 * - Re-enabled Netscape 200/404 bug workaround in block_url():
179 * - Removed OS/2 special case
180 * - Made block_url() independant from sed() having been run
181 * - Made trust_url independant from sed() having been run
182 * - Made is_imageurl independant from sed() having been run.
183 * It now checks User-Agent: and Accept: by itself.
186 * Revision 1.39 2001/10/25 03:40:48 david__schmidt
187 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
188 * threads to call select() simultaneously. So, it's time to do a real, live,
189 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
190 * (native). Both versions will work, but using __OS2__ offers multi-threading.
192 * Revision 1.38 2001/10/23 21:32:33 jongfoster
193 * Adding error-checking to selected functions
195 * Revision 1.37 2001/10/22 15:33:56 david__schmidt
196 * Special-cased OS/2 out of the Netscape-abort-on-404-in-js problem in
197 * filters.c. Added a FIXME in front of the offending code. I'll gladly
198 * put in a better/more robust fix for all parties if one is presented...
199 * It seems that just returning 200 instead of 404 would pretty much fix
200 * it for everyone, but I don't know all the history of the problem.
202 * Revision 1.36 2001/10/10 16:44:16 oes
203 * Added match_portlist function
205 * Revision 1.35 2001/10/07 15:41:23 oes
206 * Replaced 6 boolean members of csp with one bitmap (csp->flags)
208 * New function remove_chunked_transfer_coding that strips chunked
209 * transfer coding to plain and is called by pcrs_filter_response
210 * and gif_deanimate_response if neccessary
212 * Improved handling of zero-change re_filter runs
214 * pcrs_filter_response and gif_deanimate_response now remove
215 * chunked transfer codeing before processing the body.
217 * Revision 1.34 2001/09/20 15:49:36 steudten
219 * Fix BUG: Change int size to size_t size in pcrs_filter_response().
220 * See cgi.c fill_template().
222 * Revision 1.33 2001/09/16 17:05:14 jongfoster
223 * Removing unused #include showarg.h
225 * Revision 1.32 2001/09/16 13:21:27 jongfoster
226 * Changes to use new list functions.
228 * Revision 1.31 2001/09/16 11:38:02 jongfoster
229 * Splitting fill_template() into 2 functions:
230 * template_load() loads the file
231 * template_fill() performs the PCRS regexps.
232 * This is because the CGI edit interface has a "table row"
233 * template which is used many times in the page - this
234 * change means it's only loaded from disk once.
236 * Revision 1.30 2001/09/16 11:00:10 jongfoster
237 * New function alloc_http_response, for symmetry with free_http_response
239 * Revision 1.29 2001/09/13 23:32:40 jongfoster
240 * Moving image data to cgi.c rather than cgi.h
241 * Fixing a GPF under Win32 (and any other OS that protects global
242 * constants from being written to).
244 * Revision 1.28 2001/09/10 10:18:51 oes
245 * Silenced compiler warnings
247 * Revision 1.27 2001/08/05 16:06:20 jongfoster
248 * Modifiying "struct map" so that there are now separate header and
249 * "map_entry" structures. This means that functions which modify a
250 * map no longer need to return a pointer to the modified map.
251 * Also, it no longer reverses the order of the entries (which may be
252 * important with some advanced template substitutions).
254 * Revision 1.26 2001/07/30 22:08:36 jongfoster
255 * Tidying up #defines:
256 * - All feature #defines are now of the form FEATURE_xxx
257 * - Permanently turned off WIN_GUI_EDIT
258 * - Permanently turned on WEBDAV and SPLIT_PROXY_ARGS
260 * Revision 1.25 2001/07/26 10:09:46 oes
261 * Made browser detection a little less naive
263 * Revision 1.24 2001/07/25 17:22:51 oes
264 * Added workaround for Netscape bug that prevents display of page when loading a component fails.
266 * Revision 1.23 2001/07/23 13:40:12 oes
267 * Fixed bug that caused document body to be dropped when pcrs joblist was empty.
269 * Revision 1.22 2001/07/18 12:29:34 oes
270 * - Made gif_deanimate_response respect
271 * csp->action->string[ACTION_STRING_DEANIMATE]
272 * - Logging cosmetics
274 * Revision 1.21 2001/07/13 13:59:53 oes
275 * - Introduced gif_deanimate_response which shares the
276 * generic content modification interface of pcrs_filter_response
277 * and acts as a wrapper to deanimate.c:gif_deanimate()
278 * - Renamed re_process_buffer to pcrs_filter_response
279 * - pcrs_filter_response now returns NULL on failiure
280 * - Removed all #ifdef PCRS
282 * Revision 1.20 2001/07/01 17:01:04 oes
283 * Added comments and missing return statement in is_untrusted_url()
285 * Revision 1.19 2001/06/29 21:45:41 oes
286 * Indentation, CRLF->LF, Tab-> Space
288 * Revision 1.18 2001/06/29 13:27:38 oes
289 * - Cleaned up, renamed and reorderd functions
290 * and improved comments
293 * - Ported to CGI platform. Now delivers
294 * http_response or NULL
295 * - Unified HTML and GIF generation (moved image detection
296 * and GIF generation here from jcc.c:chat())
297 * - Fixed HTTP status to:
298 * - 403 (Forbidden) for the "blocked" HTML message
299 * - 200 (OK) for GIF answers
300 * - 302 (Redirect) for redirect to GIF
303 * - Ported to CGI platform. Now delivers
304 * http_response or NULL
305 * - Separated detection of untrusted URL into
306 * (bool)is_untrusted_url
307 * - Added enforcement of untrusted requests
309 * - Moved redirect_url() from cgi.c to here
310 * and ported it to the CGI platform
312 * - Removed logentry from cancelled commit
314 * Revision 1.17 2001/06/09 10:55:28 jongfoster
315 * Changing BUFSIZ ==> BUFFER_SIZE
317 * Revision 1.16 2001/06/07 23:10:26 jongfoster
318 * Allowing unanchored domain patterns to back off and retry
319 * if they partially match. Optimized right-anchored patterns.
320 * Moving ACL and forward files into config file.
321 * Replacing struct gateway with struct forward_spec
323 * Revision 1.15 2001/06/03 19:12:00 oes
324 * extracted-CGI relevant stuff
326 * Revision 1.14 2001/06/01 10:30:55 oes
327 * Added optional left-anchoring to domaincmp
329 * Revision 1.13 2001/05/31 21:21:30 jongfoster
330 * Permissionsfile / actions file changes:
331 * - Changed "permission" to "action" throughout
332 * - changes to file format to allow string parameters
333 * - Moved helper functions to actions.c
335 * Revision 1.12 2001/05/31 17:35:20 oes
337 * - Enhanced domain part globbing with infix and prefix asterisk
338 * matching and optional unanchored operation
340 * Revision 1.11 2001/05/29 11:53:23 oes
341 * "See why" link added to "blocked" page
343 * Revision 1.10 2001/05/29 09:50:24 jongfoster
344 * Unified blocklist/imagelist/permissionslist.
345 * File format is still under discussion, but the internal changes
348 * Also modified interceptor behaviour:
349 * - We now intercept all URLs beginning with one of the following
350 * prefixes (and *only* these prefixes):
352 * * http://ijbswa.sf.net/config/
353 * * http://ijbswa.sourceforge.net/config/
354 * - New interceptors "home page" - go to http://i.j.b/ to see it.
355 * - Internal changes so that intercepted and fast redirect pages
356 * are not replaced with an image.
357 * - Interceptors now have the option to send a binary page direct
358 * to the client. (i.e. ijb-send-banner uses this)
359 * - Implemented show-url-info interceptor. (Which is why I needed
360 * the above interceptors changes - a typical URL is
361 * "http://i.j.b/show-url-info?url=www.somesite.com/banner.gif".
362 * The previous mechanism would not have intercepted that, and
363 * if it had been intercepted then it then it would have replaced
366 * Revision 1.9 2001/05/27 22:17:04 oes
368 * - re_process_buffer no longer writes the modified buffer
369 * to the client, which was very ugly. It now returns the
370 * buffer, which it is then written by chat.
372 * - content_length now adjusts the Content-Length: header
373 * for modified documents rather than crunch()ing it.
374 * (Length info in csp->content_length, which is 0 for
375 * unmodified documents)
377 * - For this to work, sed() is called twice when filtering.
379 * Revision 1.8 2001/05/26 17:13:28 jongfoster
380 * Filled in a function comment.
382 * Revision 1.7 2001/05/26 15:26:15 jongfoster
383 * ACL feature now provides more security by immediately dropping
384 * connections from untrusted hosts.
386 * Revision 1.6 2001/05/26 00:28:36 jongfoster
387 * Automatic reloading of config file.
388 * Removed obsolete SIGHUP support (Unix) and Reload menu option (Win32).
389 * Most of the global variables have been moved to a new
390 * struct configuration_spec, accessed through csp->config->globalname
391 * Most of the globals remaining are used by the Win32 GUI.
393 * Revision 1.5 2001/05/25 22:34:30 jongfoster
396 * Revision 1.4 2001/05/22 18:46:04 oes
398 * - Enabled filtering banners by size rather than URL
399 * by adding patterns that replace all standard banner
400 * sizes with the "Junkbuster" gif to the re_filterfile
402 * - Enabled filtering WebBugs by providing a pattern
403 * which kills all 1x1 images
405 * - Added support for PCRE_UNGREEDY behaviour to pcrs,
406 * which is selected by the (nonstandard and therefore
407 * capital) letter 'U' in the option string.
408 * It causes the quantifiers to be ungreedy by default.
409 * Appending a ? turns back to greedy (!).
411 * - Added a new interceptor ijb-send-banner, which
412 * sends back the "Junkbuster" gif. Without imagelist or
413 * MSIE detection support, or if tinygif = 1, or the
414 * URL isn't recognized as an imageurl, a lame HTML
415 * explanation is sent instead.
417 * - Added new feature, which permits blocking remote
418 * script redirects and firing back a local redirect
420 * The feature is conditionally compiled, i.e. it
421 * can be disabled with --disable-fast-redirects,
422 * plus it must be activated by a "fast-redirects"
423 * line in the config file, has its own log level
424 * and of course wants to be displayed by show-proxy-args
425 * Note: Boy, all the #ifdefs in 1001 locations and
426 * all the fumbling with configure.in and acconfig.h
427 * were *way* more work than the feature itself :-(
429 * - Because a generic redirect template was needed for
430 * this, tinygif = 3 now uses the same.
432 * - Moved GIFs, and other static HTTP response templates
437 * - Removed some >400 CRs again (Jon, you really worked
440 * Revision 1.3 2001/05/20 16:44:47 jongfoster
441 * Removing last hardcoded Junkbusters.com URLs.
443 * Revision 1.2 2001/05/20 01:21:20 jongfoster
444 * Version 2.9.4 checkin.
445 * - Merged popupfile and cookiefile, and added control over PCRS
446 * filtering, in new "permissionsfile".
447 * - Implemented LOG_LEVEL_FATAL, so that if there is a configuration
448 * file error you now get a message box (in the Win32 GUI) rather
449 * than the program exiting with no explanation.
450 * - Made killpopup use the PCRS MIME-type checking and HTTP-header
452 * - Removed tabs from "config"
453 * - Moved duplicated url parsing code in "loaders.c" to a new funcition.
454 * - Bumped up version number.
456 * Revision 1.1.1.1 2001/05/15 13:58:52 oes
457 * Initial import of version 2.9.3 source tree
460 *********************************************************************/
466 #include <sys/types.h>
475 #endif /* ndef __OS2__ */
476 #include <netinet/in.h>
478 #include <winsock2.h>
479 #endif /* ndef _WIN32 */
483 #endif /* def __OS2__ */
491 #include "jbsockets.h"
492 #include "miscutil.h"
496 #include "deanimate.h"
497 #include "urlmatch.h"
503 const char filters_h_rcs[] = FILTERS_H_VERSION;
505 /* Fix a problem with Solaris. There should be no effect on other
507 * Solaris's isspace() is a macro which uses it's argument directly
508 * as an array index. Therefore we need to make sure that high-bit
509 * characters generate +ve values, and ideally we also want to make
510 * the argument match the declared parameter type of "int".
512 #define ijb_isdigit(__X) isdigit((int)(unsigned char)(__X))
516 /*********************************************************************
518 * Function : block_acl
520 * Description : Block this request?
521 * Decide yes or no based on ACL file.
524 * 1 : dst = The proxy or gateway address this is going to.
525 * Or NULL to check all possible targets.
526 * 2 : csp = Current client state (buffers, headers, etc...)
527 * Also includes the client IP address.
529 * Returns : 0 = FALSE (don't block) and 1 = TRUE (do block)
531 *********************************************************************/
532 int block_acl(struct access_control_addr *dst, struct client_state *csp)
534 struct access_control_list *acl = csp->config->acl;
536 /* if not using an access control list, then permit the connection */
542 /* search the list */
545 if ((csp->ip_addr_long & acl->src->mask) == acl->src->addr)
549 /* Just want to check if they have any access */
550 if (acl->action == ACL_PERMIT)
555 else if ( ((dst->addr & acl->dst->mask) == acl->dst->addr)
556 && ((dst->port == acl->dst->port) || (acl->dst->port == 0)))
558 if (acl->action == ACL_PERMIT)
576 /*********************************************************************
578 * Function : acl_addr
580 * Description : Called from `load_config' to parse an ACL address.
583 * 1 : aspec = String specifying ACL address.
584 * 2 : aca = struct access_control_addr to fill in.
586 * Returns : 0 => Ok, everything else is an error.
588 *********************************************************************/
589 int acl_addr(char *aspec, struct access_control_addr *aca)
591 int i, masklength, port;
597 if ((p = strchr(aspec, '/')) != NULL)
601 if (ijb_isdigit(*p) == 0)
605 masklength = atoi(p);
608 if ((masklength < 0) || (masklength > 32))
613 if ((p = strchr(aspec, ':')) != NULL)
617 if (ijb_isdigit(*p) == 0)
626 aca->addr = ntohl(resolve_hostname_to_ip(aspec));
628 if (aca->addr == INADDR_NONE)
633 /* build the netmask */
635 for (i=1; i <= masklength ; i++)
637 aca->mask |= (1 << (32 - i));
640 /* now mask off the host portion of the ip address
641 * (i.e. save on the network portion of the address).
643 aca->addr = aca->addr & aca->mask;
648 #endif /* def FEATURE_ACL */
651 /*********************************************************************
653 * Function : match_portlist
655 * Description : Check if a given number is covered by a comma
656 * separated list of numbers and ranges (a,b-c,d,..)
659 * 1 : portlist = String with list
660 * 2 : port = port to check
662 * Returns : 0 => no match
665 *********************************************************************/
666 int match_portlist(const char *portlist, int port)
668 char *min, *max, *next, *portlist_copy;
670 min = next = portlist_copy = strdup(portlist);
673 * Zero-terminate first item and remember offset for next
675 if (NULL != (next = strchr(portlist_copy, (int) ',')))
681 * Loop through all items, checking for match
685 if (NULL == (max = strchr(min, (int) '-')))
688 * No dash, check for equality
690 if (port == atoi(min))
699 * This is a range, so check if between min and max,
700 * or, if max was omitted, between min and 65K
703 if(port >= atoi(min) && port <= (atoi(max) ? atoi(max) : 65535))
717 * Zero-terminate next item and remember offset for n+1
719 if ((NULL != next) && (NULL != (next = strchr(next, (int) ','))))
731 /*********************************************************************
733 * Function : block_url
735 * Description : Called from `chat'. Check to see if we need to block this.
738 * 1 : csp = Current client state (buffers, headers, etc...)
740 * Returns : NULL => unblocked, else HTTP block response
742 *********************************************************************/
743 struct http_response *block_url(struct client_state *csp)
745 struct http_response *rsp;
746 const char *new_content_type = NULL;
749 * If it's not blocked, don't block it ;-)
751 if ((csp->action->flags & ACTION_BLOCK) == 0)
755 if (csp->action->flags & ACTION_REDIRECT)
757 log_error(LOG_LEVEL_ERROR, "redirect{} overruled by block.");
760 * Else, prepare a response
762 if (NULL == (rsp = alloc_http_response()))
764 return cgi_error_memory();
768 * If it's an image-url, send back an image or redirect
769 * as specified by the relevant +image action
771 #ifdef FEATURE_IMAGE_BLOCKING
772 if (((csp->action->flags & ACTION_IMAGE_BLOCKER) != 0)
776 /* determine HOW images should be blocked */
777 p = csp->action->string[ACTION_STRING_IMAGE_BLOCKER];
779 if(csp->action->flags & ACTION_HANDLE_AS_EMPTY_DOCUMENT)
781 log_error(LOG_LEVEL_ERROR, "handle-as-empty-document overruled by handle-as-image.");
783 #if 1 /* Two alternative strategies, use this one for now: */
785 /* and handle accordingly: */
786 if ((p == NULL) || (0 == strcmpic(p, "pattern")))
788 rsp->status = strdup("403 Request blocked by Privoxy");
789 if (rsp->status == NULL)
791 free_http_response(rsp);
792 return cgi_error_memory();
794 rsp->body = bindup(image_pattern_data, image_pattern_length);
795 if (rsp->body == NULL)
797 free_http_response(rsp);
798 return cgi_error_memory();
800 rsp->content_length = image_pattern_length;
802 if (enlist_unique_header(rsp->headers, "Content-Type", BUILTIN_IMAGE_MIMETYPE))
804 free_http_response(rsp);
805 return cgi_error_memory();
809 else if (0 == strcmpic(p, "blank"))
811 rsp->status = strdup("403 Request blocked by Privoxy");
812 if (rsp->status == NULL)
814 free_http_response(rsp);
815 return cgi_error_memory();
817 rsp->body = bindup(image_blank_data, image_blank_length);
818 if (rsp->body == NULL)
820 free_http_response(rsp);
821 return cgi_error_memory();
823 rsp->content_length = image_blank_length;
825 if (enlist_unique_header(rsp->headers, "Content-Type", BUILTIN_IMAGE_MIMETYPE))
827 free_http_response(rsp);
828 return cgi_error_memory();
834 rsp->status = strdup("302 Local Redirect from Privoxy");
835 if (rsp->status == NULL)
837 free_http_response(rsp);
838 return cgi_error_memory();
841 if (enlist_unique_header(rsp->headers, "Location", p))
843 free_http_response(rsp);
844 return cgi_error_memory();
848 #else /* Following code is disabled for now */
850 /* and handle accordingly: */
851 if ((p == NULL) || (0 == strcmpic(p, "pattern")))
853 p = CGI_PREFIX "send-banner?type=pattern";
855 else if (0 == strcmpic(p, "blank"))
857 p = CGI_PREFIX "send-banner?type=blank";
859 rsp->status = strdup("302 Local Redirect from Privoxy");
860 if (rsp->status == NULL)
862 free_http_response(rsp);
863 return cgi_error_memory();
866 if (enlist_unique_header(rsp->headers, "Location", p))
868 free_http_response(rsp);
869 return cgi_error_memory();
871 #endif /* Preceeding code is disabled for now */
873 else if(csp->action->flags & ACTION_HANDLE_AS_EMPTY_DOCUMENT)
876 * Send empty document.
878 new_content_type = csp->action->string[ACTION_STRING_CONTENT_TYPE];
881 rsp->body = strdup(" ");
882 rsp->content_length = 1;
884 rsp->status = strdup("403 Request blocked by Privoxy");
885 if (rsp->status == NULL)
887 free_http_response(rsp);
888 return cgi_error_memory();
890 if (new_content_type != 0)
892 log_error(LOG_LEVEL_HEADER, "Overwriting Content-Type with %s", new_content_type);
893 if (enlist_unique_header(rsp->headers, "Content-Type", new_content_type))
895 free_http_response(rsp);
896 return cgi_error_memory();
902 #endif /* def FEATURE_IMAGE_BLOCKING */
905 * Else, generate an HTML "blocked" message:
909 struct map * exports;
913 * Workaround for stupid Netscape bug which prevents
914 * pages from being displayed if loading a referenced
915 * JavaScript or style sheet fails. So make it appear
916 * as if it succeeded.
918 if ( NULL != (p = get_header_value(csp->headers, "User-Agent:"))
919 && !strncmpic(p, "mozilla", 7) /* Catch Netscape but */
920 && !strstr(p, "Gecko") /* save Mozilla, */
921 && !strstr(p, "compatible") /* MSIE */
922 && !strstr(p, "Opera")) /* and Opera. */
924 rsp->status = strdup("200 Request for blocked URL");
928 rsp->status = strdup("404 Request for blocked URL");
931 if (rsp->status == NULL)
933 free_http_response(rsp);
934 return cgi_error_memory();
937 exports = default_exports(csp, NULL);
940 free_http_response(rsp);
941 return cgi_error_memory();
944 #ifdef FEATURE_FORCE_LOAD
945 err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
946 if (csp->http->ssl != 0)
947 #endif /* ndef FEATURE_FORCE_LOAD */
949 err = map_block_killer(exports, "force-support");
952 if (!err) err = map(exports, "protocol", 1, csp->http->ssl ? "https://" : "http://", 1);
953 if (!err) err = map(exports, "hostport", 1, html_encode(csp->http->hostport), 0);
954 if (!err) err = map(exports, "path", 1, html_encode(csp->http->path), 0);
955 if (!err) err = map(exports, "path-ue", 1, url_encode(csp->http->path), 0);
960 free_http_response(rsp);
961 return cgi_error_memory();
964 err = template_fill_for_cgi(csp, "blocked", exports, rsp);
967 free_http_response(rsp);
968 return cgi_error_memory();
972 return finish_http_response(rsp);
978 /*********************************************************************
980 * Function : trust_url FIXME: I should be called distrust_url
982 * Description : Calls is_untrusted_url to determine if the URL is trusted
983 * and if not, returns a HTTP 403 response with a reject message.
986 * 1 : csp = Current client state (buffers, headers, etc...)
988 * Returns : NULL => trusted, else http_response.
990 *********************************************************************/
991 struct http_response *trust_url(struct client_state *csp)
993 struct http_response *rsp;
994 struct map * exports;
995 char buf[BUFFER_SIZE];
997 struct url_spec **tl;
1002 * Don't bother to work on trusted URLs
1004 if (!is_untrusted_url(csp))
1010 * Else, prepare a response:
1012 if (NULL == (rsp = alloc_http_response()))
1014 return cgi_error_memory();
1017 rsp->status = strdup("403 Request blocked by Privoxy");
1018 exports = default_exports(csp, NULL);
1019 if (exports == NULL || rsp->status == NULL)
1021 free_http_response(rsp);
1022 return cgi_error_memory();
1026 * Export the protocol, host, port, and referrer information
1028 err = map(exports, "hostport", 1, csp->http->hostport, 1);
1029 if (!err) err = map(exports, "protocol", 1, csp->http->ssl ? "https://" : "http://", 1);
1030 if (!err) err = map(exports, "path", 1, csp->http->path, 1);
1032 if (NULL != (p = get_header_value(csp->headers, "Referer:")))
1034 if (!err) err = map(exports, "referrer", 1, html_encode(p), 0);
1038 if (!err) err = map(exports, "referrer", 1, "none set", 1);
1044 free_http_response(rsp);
1045 return cgi_error_memory();
1049 * Export the trust list
1052 for (tl = csp->config->trust_list; (t = *tl) != NULL ; tl++)
1054 sprintf(buf, "<li>%s</li>\n", t->spec);
1055 string_append(&p, buf);
1057 err = map(exports, "trusted-referrers", 1, p, 0);
1062 free_http_response(rsp);
1063 return cgi_error_memory();
1067 * Export the trust info, if available
1069 if (csp->config->trust_info->first)
1071 struct list_entry *l;
1074 for (l = csp->config->trust_info->first; l ; l = l->next)
1076 sprintf(buf, "<li> <a href=\"%s\">%s</a><br>\n",l->str, l->str);
1077 string_append(&p, buf);
1079 err = map(exports, "trust-info", 1, p, 0);
1083 err = map_block_killer(exports, "have-trust-info");
1089 free_http_response(rsp);
1090 return cgi_error_memory();
1094 * Export the force prefix or the force conditional block killer
1096 #ifdef FEATURE_FORCE_LOAD
1097 err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
1098 #else /* ifndef FEATURE_FORCE_LOAD */
1099 err = map_block_killer(exports, "force-support");
1100 #endif /* ndef FEATURE_FORCE_LOAD */
1105 free_http_response(rsp);
1106 return cgi_error_memory();
1110 * Build the response
1112 err = template_fill_for_cgi(csp, "untrusted", exports, rsp);
1115 free_http_response(rsp);
1116 return cgi_error_memory();
1119 return finish_http_response(rsp);
1121 #endif /* def FEATURE_TRUST */
1124 #ifdef FEATURE_FAST_REDIRECTS
1125 /*********************************************************************
1127 * Function : redirect_url
1129 * Description : Checks for redirection URLs and returns a HTTP redirect
1130 * to the destination URL, if necessary
1133 * 1 : csp = Current client state (buffers, headers, etc...)
1135 * Returns : NULL if URL was clean, HTTP redirect otherwise.
1137 *********************************************************************/
1138 struct http_response *redirect_url(struct client_state *csp)
1141 struct http_response *rsp;
1142 char *redirect_mode = NULL;
1145 if ((csp->action->flags & ACTION_REDIRECT))
1147 q = csp->action->string[ACTION_STRING_REDIRECT];
1149 else if ((csp->action->flags & ACTION_FAST_REDIRECTS))
1151 redirect_mode = csp->action->string[ACTION_STRING_FAST_REDIRECTS];
1152 if (0 == strcmpic(redirect_mode, "check-decoded-url"))
1154 p = q = csp->http->path;
1155 log_error(LOG_LEVEL_REDIRECTS, "Decoding path: %s if necessary.", p);
1158 if (*p == '%') /* Escape sequence? */
1160 /* Yes, translate from hexadecimal to decimal */
1174 /* No, forward character. */
1180 p = q = csp->http->path;
1181 log_error(LOG_LEVEL_REDIRECTS, "Checking path for redirects: %s", p);
1184 * find the last URL encoded in the request
1186 while ((p = strstr(p, "http://")) != NULL)
1193 /* All redirection actions are disabled */
1197 * if there was any, generate and return a HTTP redirect
1199 if (q != csp->http->path)
1201 log_error(LOG_LEVEL_REDIRECTS, "redirecting to: %s", q);
1203 if (NULL == (rsp = alloc_http_response()))
1205 return cgi_error_memory();
1208 if ( enlist_unique_header(rsp->headers, "Location", q)
1209 || (NULL == (rsp->status = strdup("302 Local Redirect from Privoxy"))) )
1211 free_http_response(rsp);
1212 return cgi_error_memory();
1215 return finish_http_response(rsp);
1223 #endif /* def FEATURE_FAST_REDIRECTS */
1226 #ifdef FEATURE_IMAGE_BLOCKING
1227 /*********************************************************************
1229 * Function : is_imageurl
1231 * Description : Given a URL, decide whether it is an image or not,
1232 * using either the info from a previous +image action
1233 * or, #ifdef FEATURE_IMAGE_DETECT_MSIE, and the browser
1234 * is MSIE and not on a Mac, tell from the browser's accept
1238 * 1 : csp = Current client state (buffers, headers, etc...)
1240 * Returns : True (nonzero) if URL is an image, false (0)
1243 *********************************************************************/
1244 int is_imageurl(struct client_state *csp)
1246 #ifdef FEATURE_IMAGE_DETECT_MSIE
1249 tmp = get_header_value(csp->headers, "User-Agent:");
1250 if (tmp && strstr(tmp, "MSIE") && !strstr(tmp, "Mac_"))
1252 tmp = get_header_value(csp->headers, "Accept:");
1253 if (tmp && strstr(tmp, "image/gif"))
1255 /* Client will accept HTML. If this seems counterintuitive,
1265 #endif /* def FEATURE_IMAGE_DETECT_MSIE */
1267 return ((csp->action->flags & ACTION_IMAGE) != 0);
1270 #endif /* def FEATURE_IMAGE_BLOCKING */
1273 #ifdef FEATURE_TRUST
1274 /*********************************************************************
1276 * Function : is_untrusted_url
1278 * Description : Should we "distrust" this URL (and block it)?
1280 * Yes if it matches a line in the trustfile, or if the
1281 * referrer matches a line starting with "+" in the
1286 * 1 : csp = Current client state (buffers, headers, etc...)
1288 * Returns : 0 => trusted, 1 => untrusted
1290 *********************************************************************/
1291 int is_untrusted_url(struct client_state *csp)
1293 struct file_list *fl;
1294 struct block_spec *b;
1295 struct url_spec **trusted_url;
1296 struct http_request rhttp[1];
1297 const char * referer;
1301 * If we don't have a trustlist, we trust everybody
1303 if (((fl = csp->tlist) == NULL) || ((b = fl->f) == NULL))
1308 memset(rhttp, '\0', sizeof(*rhttp));
1311 * Do we trust the request URL itself?
1313 for (b = b->next; b ; b = b->next)
1315 if (url_match(b->url, csp->http))
1321 if (NULL == (referer = get_header_value(csp->headers, "Referer:")))
1323 /* no referrer was supplied */
1329 * If not, do we maybe trust its referrer?
1331 err = parse_http_url(referer, rhttp, csp);
1337 for (trusted_url = csp->config->trust_list; *trusted_url != NULL; trusted_url++)
1339 if (url_match(*trusted_url, rhttp))
1341 /* if the URL's referrer is from a trusted referrer, then
1342 * add the target spec to the trustfile as an unblocked
1343 * domain and return NULL (which means it's OK).
1348 if (NULL != (fp = fopen(csp->config->trustfile, "a")))
1352 char * new_entry = strdup("~");
1354 string_append(&new_entry, csp->http->hostport);
1356 path = csp->http->path;
1357 if ( (path[0] == '/')
1359 && ((path_end = strchr(path + 2, '/')) != NULL))
1361 /* since this path points into a user's home space
1362 * be sure to include this spec in the trustfile.
1364 int path_len = path_end - path; /* save offset */
1365 path = strdup(path); /* Copy string */
1368 path_end = path + path_len; /* regenerate ptr to new buffer */
1369 *(path_end + 1) = '\0'; /* Truncate path after '/' */
1371 string_join(&new_entry, path);
1374 if (new_entry != NULL)
1376 fprintf(fp, "%s\n", new_entry);
1381 /* FIXME: No way to handle out-of memory, so mostly ignoring it */
1382 log_error(LOG_LEVEL_ERROR, "Out of memory adding pattern to trust file");
1392 #endif /* def FEATURE_TRUST */
1395 /*********************************************************************
1397 * Function : pcrs_filter_response
1399 * Description : Execute all text substitutions from all applying
1400 * +filter actions on the text buffer that's been accumulated
1401 * in csp->iob->buf. If this changes the contents, set
1402 * csp->content_length to the modified size and raise the
1403 * CSP_FLAG_MODIFIED flag.
1406 * 1 : csp = Current client state (buffers, headers, etc...)
1408 * Returns : a pointer to the (newly allocated) modified buffer.
1409 * or NULL if there were no hits or something went wrong
1411 *********************************************************************/
1412 char *pcrs_filter_response(struct client_state *csp)
1415 size_t size, prev_size;
1417 char *old = csp->iob->cur, *new = NULL;
1420 struct file_list *fl;
1421 struct re_filterfile_spec *b;
1422 struct list_entry *filtername;
1424 int i, found_filters = 0;
1429 if (csp->iob->cur >= csp->iob->eod)
1433 size = csp->iob->eod - csp->iob->cur;
1436 * Need to check the set of re_filterfiles...
1438 for (i = 0; i < MAX_AF_FILES; i++)
1451 if (0 == found_filters)
1453 log_error(LOG_LEVEL_ERROR, "Unable to get current state of regexp filtering.");
1458 * If the body has a "chunked" transfer-encoding,
1459 * get rid of it first, adjusting size and iob->eod
1461 if (csp->flags & CSP_FLAG_CHUNKED)
1463 log_error(LOG_LEVEL_RE_FILTER, "Need to de-chunk first");
1464 if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
1468 csp->iob->eod = csp->iob->cur + size;
1469 csp->flags |= CSP_FLAG_MODIFIED;
1472 for (i = 0; i < MAX_AF_FILES; i++)
1475 if ((NULL == fl) || (NULL == fl->f))
1478 * For all applying +filter actions, look if a filter by that
1479 * name exists and if yes, execute it's pcrs_joblist on the
1482 for (b = fl->f; b; b = b->next)
1484 for (filtername = csp->action->multi[ACTION_MULTI_FILTER]->first;
1485 filtername ; filtername = filtername->next)
1487 if (strcmp(b->name, filtername->str) == 0)
1489 int current_hits = 0;
1491 if ( NULL == b->joblist )
1493 log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name);
1498 /* Apply all jobs from the joblist */
1499 for (job = b->joblist; NULL != job; job = job->next)
1501 current_hits += pcrs_execute(job, old, size, &new, &size);
1502 if (old != csp->iob->cur) free(old);
1506 log_error(LOG_LEVEL_RE_FILTER, "re_filtering %s%s (size %d) with filter %s produced %d hits (new size %d).",
1507 csp->http->hostport, csp->http->path, prev_size, b->name, current_hits, size);
1509 hits += current_hits;
1516 * If there were no hits, destroy our copy and let
1517 * chat() use the original in csp->iob
1525 csp->flags |= CSP_FLAG_MODIFIED;
1526 csp->content_length = size;
1534 /*********************************************************************
1536 * Function : gif_deanimate_response
1538 * Description : Deanimate the GIF image that has been accumulated in
1539 * csp->iob->buf, set csp->content_length to the modified
1540 * size and raise the CSP_FLAG_MODIFIED flag.
1543 * 1 : csp = Current client state (buffers, headers, etc...)
1545 * Returns : a pointer to the (newly allocated) modified buffer.
1546 * or NULL in case something went wrong.
1548 *********************************************************************/
1549 char *gif_deanimate_response(struct client_state *csp)
1551 struct binbuffer *in, *out;
1553 size_t size = csp->iob->eod - csp->iob->cur;
1556 * If the body has a "chunked" transfer-encoding,
1557 * get rid of it first, adjusting size and iob->eod
1559 if (csp->flags & CSP_FLAG_CHUNKED)
1561 log_error(LOG_LEVEL_DEANIMATE, "Need to de-chunk first");
1562 if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
1566 csp->iob->eod = csp->iob->cur + size;
1567 csp->flags |= CSP_FLAG_MODIFIED;
1570 if ( (NULL == (in = (struct binbuffer *)zalloc(sizeof *in )))
1571 || (NULL == (out = (struct binbuffer *)zalloc(sizeof *out))) )
1573 log_error(LOG_LEVEL_DEANIMATE, "failed! (no mem)");
1577 in->buffer = csp->iob->cur;
1580 if (gif_deanimate(in, out, strncmp("last", csp->action->string[ACTION_STRING_DEANIMATE], 4)))
1582 log_error(LOG_LEVEL_DEANIMATE, "failed! (gif parsing)");
1589 if ((int)size == out->offset)
1591 log_error(LOG_LEVEL_DEANIMATE, "GIF not changed.");
1595 log_error(LOG_LEVEL_DEANIMATE, "Success! GIF shrunk from %d bytes to %d.", size, out->offset);
1597 csp->content_length = out->offset;
1598 csp->flags |= CSP_FLAG_MODIFIED;
1608 /*********************************************************************
1610 * Function : jpeg_inspect_response
1615 * 1 : csp = Current client state (buffers, headers, etc...)
1617 * Returns : a pointer to the (newly allocated) modified buffer
1618 * or NULL in case something went wrong.
1620 *********************************************************************/
1621 char *jpeg_inspect_response(struct client_state *csp)
1623 struct binbuffer *in = NULL, *out = NULL;
1625 size_t size = csp->iob->eod - csp->iob->cur;
1628 * If the body has a "chunked" transfer-encoding,
1629 * get rid of it first, adjusting size and iob->eod
1631 if (csp->flags & CSP_FLAG_CHUNKED)
1633 log_error(LOG_LEVEL_DEANIMATE, "Need to de-chunk first");
1634 if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
1638 csp->iob->eod = csp->iob->cur + size;
1639 csp->flags |= CSP_FLAG_MODIFIED;
1642 if (NULL == (in = (struct binbuffer *)zalloc(sizeof *in )))
1644 log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg no mem 1)");
1648 if (NULL == (out = (struct binbuffer *)zalloc(sizeof *out)))
1650 log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg no mem 2)");
1654 in->buffer = csp->iob->cur;
1658 * Calling jpeg_inspect has the side-effect of creating and
1659 * modifying the image buffer of "out" directly.
1661 if (jpeg_inspect(in, out))
1663 log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg parsing)");
1671 csp->content_length = out->offset;
1672 csp->flags |= CSP_FLAG_MODIFIED;
1682 /*********************************************************************
1684 * Function : remove_chunked_transfer_coding
1686 * Description : In-situ remove the "chunked" transfer coding as defined
1687 * in rfc2616 from a buffer.
1690 * 1 : buffer = Pointer to the text buffer
1691 * 2 : size = Number of bytes to be processed
1693 * Returns : The new size, i.e. the number of bytes from buffer which
1694 * are occupied by the stripped body, or 0 in case something
1697 *********************************************************************/
1698 int remove_chunked_transfer_coding(char *buffer, const size_t size)
1701 unsigned int chunksize = 0;
1702 char *from_p, *to_p;
1705 from_p = to_p = buffer;
1707 if (sscanf(buffer, "%x", &chunksize) != 1)
1709 log_error(LOG_LEVEL_ERROR, "Invalid first chunksize while stripping \"chunked\" transfer coding");
1713 while (chunksize > 0)
1715 if (NULL == (from_p = strstr(from_p, "\r\n")))
1717 log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding");
1721 if ((newsize += chunksize) >= size)
1723 log_error(LOG_LEVEL_ERROR, "Chunksize exceeds buffer in \"chunked\" transfer coding");
1728 memmove(to_p, from_p, (size_t) chunksize);
1729 to_p = buffer + newsize;
1730 from_p += chunksize + 2;
1732 if (sscanf(from_p, "%x", &chunksize) != 1)
1734 log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding");
1739 /* FIXME: Should this get its own loglevel? */
1740 log_error(LOG_LEVEL_RE_FILTER, "De-chunking successful. Shrunk from %d to %d\n", size, newsize);
1746 /*********************************************************************
1748 * Function : url_actions
1750 * Description : Gets the actions for this URL.
1753 * 1 : http = http_request request for blocked URLs
1754 * 2 : csp = Current client state (buffers, headers, etc...)
1758 *********************************************************************/
1759 void url_actions(struct http_request *http,
1760 struct client_state *csp)
1762 struct file_list *fl;
1763 struct url_actions *b;
1766 init_current_action(csp->action);
1768 for (i = 0; i < MAX_AF_FILES; i++)
1770 if (((fl = csp->actions_list[i]) == NULL) || ((b = fl->f) == NULL))
1775 apply_url_actions(csp->action, http, b);
1782 /*********************************************************************
1784 * Function : apply_url_actions
1786 * Description : Applies a list of URL actions.
1789 * 1 : action = Destination.
1790 * 2 : http = Current URL
1791 * 3 : b = list of URL actions to apply
1795 *********************************************************************/
1796 void apply_url_actions(struct current_action_spec *action,
1797 struct http_request *http,
1798 struct url_actions *b)
1802 /* Should never happen */
1806 for (b = b->next; NULL != b; b = b->next)
1808 if (url_match(b->url, http))
1810 merge_current_action(action, b->action);
1816 /*********************************************************************
1818 * Function : forward_url
1820 * Description : Should we forward this to another proxy?
1823 * 1 : http = http_request request for current URL
1824 * 2 : csp = Current client state (buffers, headers, etc...)
1826 * Returns : Pointer to forwarding information.
1828 *********************************************************************/
1829 const struct forward_spec * forward_url(struct http_request *http,
1830 struct client_state *csp)
1832 static const struct forward_spec fwd_default[1] = { FORWARD_SPEC_INITIALIZER };
1833 struct forward_spec *fwd = csp->config->forward;
1842 if (url_match(fwd->url, http))
1853 /*********************************************************************
1855 * Function : direct_response
1857 * Description : Check if Max-Forwards == 0 for an OPTIONS or TRACE
1858 * request and if so, return a HTTP 501 to the client.
1860 * FIXME: I have a stupid name and I should handle the
1861 * requests properly. Still, what we do here is rfc-
1862 * compliant, whereas ignoring or forwarding are not.
1865 * 1 : csp = Current client state (buffers, headers, etc...)
1867 * Returns : http_response if , NULL if nonmatch or handler fail
1869 *********************************************************************/
1870 struct http_response *direct_response(struct client_state *csp)
1872 struct http_response *rsp;
1873 struct list_entry *p;
1875 if ((0 == strcmpic(csp->http->gpc, "trace"))
1876 || (0 == strcmpic(csp->http->gpc, "options")))
1878 for (p = csp->headers->first; (p != NULL) ; p = p->next)
1880 if (!strncmp("Max-Forwards:", p->str, 13)
1881 && (*(p->str+13) != '\0') && (atoi(p->str+13) == 0))
1883 /* FIXME: We could handle at least TRACE here,
1884 but that would require a verbatim copy of
1885 the request which we don't have anymore */
1887 log_error(LOG_LEVEL_HEADER, "Found Max-Forwards:0 in OPTIONS or TRACE request -- Returning 501");
1889 /* Get mem for response or fail*/
1890 if (NULL == (rsp = alloc_http_response()))
1892 return cgi_error_memory();
1895 if (NULL == (rsp->status = strdup("501 Not Implemented")))
1897 free_http_response(rsp);
1898 return cgi_error_memory();
1902 return(finish_http_response(rsp));