1 const char filters_rcs[] = "$Id: filters.c,v 1.58.2.4 2003/02/28 12:52:45 oes Exp $";
2 /*********************************************************************
4 * File : $Source: /cvsroot/ijbswa/current/Attic/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', and `trust_url'
14 * Copyright : Written by and Copyright (C) 2001 the SourceForge
15 * Privoxy team. http://www.privoxy.org/
17 * Based on the Internet Junkbuster originally written
18 * by and Copyright (C) 1997 Anonymous Coders and
19 * Junkbusters Corporation. http://www.junkbusters.com
21 * This program is free software; you can redistribute it
22 * and/or modify it under the terms of the GNU General
23 * Public License as published by the Free Software
24 * Foundation; either version 2 of the License, or (at
25 * your option) any later version.
27 * This program is distributed in the hope that it will
28 * be useful, but WITHOUT ANY WARRANTY; without even the
29 * implied warranty of MERCHANTABILITY or FITNESS FOR A
30 * PARTICULAR PURPOSE. See the GNU General Public
31 * License for more details.
33 * The GNU General Public License should be included with
34 * this file. If not, you can view it at
35 * http://www.gnu.org/copyleft/gpl.html
36 * or write to the Free Software Foundation, Inc., 59
37 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
41 * Revision 1.58.2.4 2003/02/28 12:52:45 oes
44 * Revision 1.58.2.3 2002/09/25 14:51:51 oes
45 * Added basic support for OPTIONS and TRACE HTTP methods:
46 * New function direct_response which handles OPTIONS and
47 * TRACE requests whose Max-Forwards header field is zero.
49 * Revision 1.58.2.2 2002/08/01 17:18:28 oes
50 * Fixed BR 537651 / SR 579724 (MSIE image detect improper for IE/Mac)
52 * Revision 1.58.2.1 2002/07/26 15:18:53 oes
53 * - Bugfix: Executing a filters without jobs no longer results in
54 * turing off *all* filters.
55 * - Security fix: Malicious web servers can't cause a seg fault
56 * through bogus chunk sizes anymore
58 * Revision 1.58 2002/04/24 02:11:17 oes
59 * Jon's multiple AF patch: url_actions now evaluates rules
62 * Revision 1.57 2002/04/08 20:38:34 swa
65 * Revision 1.56 2002/04/05 15:51:24 oes
66 * - bugfix: error-pages now get correct request protocol
67 * - fix for invalid HTML in trust info
69 * Revision 1.55 2002/04/02 16:13:51 oes
70 * Fix: No "Go there anyway" for SSL
72 * Revision 1.54 2002/04/02 14:55:56 oes
73 * Bugfix: is_untrusted_url() now depends on FEATURE_TRUST, not FEATURE_COOKIE_JAR
75 * Revision 1.53 2002/03/26 22:29:54 swa
76 * we have a new homepage!
78 * Revision 1.52 2002/03/24 16:35:57 jongfoster
81 * Revision 1.51 2002/03/24 15:23:33 jongfoster
84 * Revision 1.50 2002/03/24 13:25:43 swa
85 * name change related issues
87 * Revision 1.49 2002/03/16 20:29:14 oes
90 * Revision 1.48 2002/03/13 20:25:34 oes
91 * Better logging for content filters
93 * Revision 1.47 2002/03/13 00:30:52 jongfoster
95 * Added option of always sending redirect for imageblock,
96 * currently disabled with #if 0.
98 * Revision 1.46 2002/03/12 01:42:49 oes
99 * Introduced modular filters
101 * Revision 1.45 2002/03/08 16:47:50 oes
102 * Added choice beween GIF and PNG built-in images
104 * Revision 1.44 2002/03/07 03:49:31 oes
105 * - Fixed compiler warnings etc
106 * - Changed built-in images from GIF to PNG
107 * (with regard to Unisys patent issue)
108 * - Added a 4x4 pattern PNG which is less intrusive
109 * than the logo but also clearly marks the deleted banners
111 * Revision 1.43 2002/01/22 23:51:59 jongfoster
112 * Replacing strsav() with the safer string_append().
114 * Adding missing html_encode() to error message generators. Where encoded
115 * and unencoded versions of a string were provided, removing the unencoded
118 * Revision 1.42 2002/01/17 21:00:32 jongfoster
119 * Moving all our URL and URL pattern parsing code to urlmatch.c.
121 * Using a single, simple url_match(pattern,url) function - rather than
122 * the 3-line match routine which was repeated all over the place.
124 * Renaming free_url to free_url_spec, since it frees a struct url_spec.
126 * Using parse_http_url() to parse URLs without faking a HTTP
127 * request line for parse_http_request().
129 * Revision 1.41 2001/11/13 00:14:07 jongfoster
130 * Fixing stupid bug now I've figured out what || means.
131 * (It always returns 0 or 1, not one of it's paramaters.)
133 * Revision 1.40 2001/10/26 17:37:55 oes
134 * - Re-enabled Netscape 200/404 bug workaround in block_url():
135 * - Removed OS/2 special case
136 * - Made block_url() independant from sed() having been run
137 * - Made trust_url independant from sed() having been run
138 * - Made is_imageurl independant from sed() having been run.
139 * It now checks User-Agent: and Accept: by itself.
142 * Revision 1.39 2001/10/25 03:40:48 david__schmidt
143 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
144 * threads to call select() simultaneously. So, it's time to do a real, live,
145 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
146 * (native). Both versions will work, but using __OS2__ offers multi-threading.
148 * Revision 1.38 2001/10/23 21:32:33 jongfoster
149 * Adding error-checking to selected functions
151 * Revision 1.37 2001/10/22 15:33:56 david__schmidt
152 * Special-cased OS/2 out of the Netscape-abort-on-404-in-js problem in
153 * filters.c. Added a FIXME in front of the offending code. I'll gladly
154 * put in a better/more robust fix for all parties if one is presented...
155 * It seems that just returning 200 instead of 404 would pretty much fix
156 * it for everyone, but I don't know all the history of the problem.
158 * Revision 1.36 2001/10/10 16:44:16 oes
159 * Added match_portlist function
161 * Revision 1.35 2001/10/07 15:41:23 oes
162 * Replaced 6 boolean members of csp with one bitmap (csp->flags)
164 * New function remove_chunked_transfer_coding that strips chunked
165 * transfer coding to plain and is called by pcrs_filter_response
166 * and gif_deanimate_response if neccessary
168 * Improved handling of zero-change re_filter runs
170 * pcrs_filter_response and gif_deanimate_response now remove
171 * chunked transfer codeing before processing the body.
173 * Revision 1.34 2001/09/20 15:49:36 steudten
175 * Fix BUG: Change int size to size_t size in pcrs_filter_response().
176 * See cgi.c fill_template().
178 * Revision 1.33 2001/09/16 17:05:14 jongfoster
179 * Removing unused #include showarg.h
181 * Revision 1.32 2001/09/16 13:21:27 jongfoster
182 * Changes to use new list functions.
184 * Revision 1.31 2001/09/16 11:38:02 jongfoster
185 * Splitting fill_template() into 2 functions:
186 * template_load() loads the file
187 * template_fill() performs the PCRS regexps.
188 * This is because the CGI edit interface has a "table row"
189 * template which is used many times in the page - this
190 * change means it's only loaded from disk once.
192 * Revision 1.30 2001/09/16 11:00:10 jongfoster
193 * New function alloc_http_response, for symmetry with free_http_response
195 * Revision 1.29 2001/09/13 23:32:40 jongfoster
196 * Moving image data to cgi.c rather than cgi.h
197 * Fixing a GPF under Win32 (and any other OS that protects global
198 * constants from being written to).
200 * Revision 1.28 2001/09/10 10:18:51 oes
201 * Silenced compiler warnings
203 * Revision 1.27 2001/08/05 16:06:20 jongfoster
204 * Modifiying "struct map" so that there are now separate header and
205 * "map_entry" structures. This means that functions which modify a
206 * map no longer need to return a pointer to the modified map.
207 * Also, it no longer reverses the order of the entries (which may be
208 * important with some advanced template substitutions).
210 * Revision 1.26 2001/07/30 22:08:36 jongfoster
211 * Tidying up #defines:
212 * - All feature #defines are now of the form FEATURE_xxx
213 * - Permanently turned off WIN_GUI_EDIT
214 * - Permanently turned on WEBDAV and SPLIT_PROXY_ARGS
216 * Revision 1.25 2001/07/26 10:09:46 oes
217 * Made browser detection a little less naive
219 * Revision 1.24 2001/07/25 17:22:51 oes
220 * Added workaround for Netscape bug that prevents display of page when loading a component fails.
222 * Revision 1.23 2001/07/23 13:40:12 oes
223 * Fixed bug that caused document body to be dropped when pcrs joblist was empty.
225 * Revision 1.22 2001/07/18 12:29:34 oes
226 * - Made gif_deanimate_response respect
227 * csp->action->string[ACTION_STRING_DEANIMATE]
228 * - Logging cosmetics
230 * Revision 1.21 2001/07/13 13:59:53 oes
231 * - Introduced gif_deanimate_response which shares the
232 * generic content modification interface of pcrs_filter_response
233 * and acts as a wrapper to deanimate.c:gif_deanimate()
234 * - Renamed re_process_buffer to pcrs_filter_response
235 * - pcrs_filter_response now returns NULL on failiure
236 * - Removed all #ifdef PCRS
238 * Revision 1.20 2001/07/01 17:01:04 oes
239 * Added comments and missing return statement in is_untrusted_url()
241 * Revision 1.19 2001/06/29 21:45:41 oes
242 * Indentation, CRLF->LF, Tab-> Space
244 * Revision 1.18 2001/06/29 13:27:38 oes
245 * - Cleaned up, renamed and reorderd functions
246 * and improved comments
249 * - Ported to CGI platform. Now delivers
250 * http_response or NULL
251 * - Unified HTML and GIF generation (moved image detection
252 * and GIF generation here from jcc.c:chat())
253 * - Fixed HTTP status to:
254 * - 403 (Forbidden) for the "blocked" HTML message
255 * - 200 (OK) for GIF answers
256 * - 302 (Redirect) for redirect to GIF
259 * - Ported to CGI platform. Now delivers
260 * http_response or NULL
261 * - Separated detection of untrusted URL into
262 * (bool)is_untrusted_url
263 * - Added enforcement of untrusted requests
265 * - Moved redirect_url() from cgi.c to here
266 * and ported it to the CGI platform
268 * - Removed logentry from cancelled commit
270 * Revision 1.17 2001/06/09 10:55:28 jongfoster
271 * Changing BUFSIZ ==> BUFFER_SIZE
273 * Revision 1.16 2001/06/07 23:10:26 jongfoster
274 * Allowing unanchored domain patterns to back off and retry
275 * if they partially match. Optimized right-anchored patterns.
276 * Moving ACL and forward files into config file.
277 * Replacing struct gateway with struct forward_spec
279 * Revision 1.15 2001/06/03 19:12:00 oes
280 * extracted-CGI relevant stuff
282 * Revision 1.14 2001/06/01 10:30:55 oes
283 * Added optional left-anchoring to domaincmp
285 * Revision 1.13 2001/05/31 21:21:30 jongfoster
286 * Permissionsfile / actions file changes:
287 * - Changed "permission" to "action" throughout
288 * - changes to file format to allow string parameters
289 * - Moved helper functions to actions.c
291 * Revision 1.12 2001/05/31 17:35:20 oes
293 * - Enhanced domain part globbing with infix and prefix asterisk
294 * matching and optional unanchored operation
296 * Revision 1.11 2001/05/29 11:53:23 oes
297 * "See why" link added to "blocked" page
299 * Revision 1.10 2001/05/29 09:50:24 jongfoster
300 * Unified blocklist/imagelist/permissionslist.
301 * File format is still under discussion, but the internal changes
304 * Also modified interceptor behaviour:
305 * - We now intercept all URLs beginning with one of the following
306 * prefixes (and *only* these prefixes):
308 * * http://ijbswa.sf.net/config/
309 * * http://ijbswa.sourceforge.net/config/
310 * - New interceptors "home page" - go to http://i.j.b/ to see it.
311 * - Internal changes so that intercepted and fast redirect pages
312 * are not replaced with an image.
313 * - Interceptors now have the option to send a binary page direct
314 * to the client. (i.e. ijb-send-banner uses this)
315 * - Implemented show-url-info interceptor. (Which is why I needed
316 * the above interceptors changes - a typical URL is
317 * "http://i.j.b/show-url-info?url=www.somesite.com/banner.gif".
318 * The previous mechanism would not have intercepted that, and
319 * if it had been intercepted then it then it would have replaced
322 * Revision 1.9 2001/05/27 22:17:04 oes
324 * - re_process_buffer no longer writes the modified buffer
325 * to the client, which was very ugly. It now returns the
326 * buffer, which it is then written by chat.
328 * - content_length now adjusts the Content-Length: header
329 * for modified documents rather than crunch()ing it.
330 * (Length info in csp->content_length, which is 0 for
331 * unmodified documents)
333 * - For this to work, sed() is called twice when filtering.
335 * Revision 1.8 2001/05/26 17:13:28 jongfoster
336 * Filled in a function comment.
338 * Revision 1.7 2001/05/26 15:26:15 jongfoster
339 * ACL feature now provides more security by immediately dropping
340 * connections from untrusted hosts.
342 * Revision 1.6 2001/05/26 00:28:36 jongfoster
343 * Automatic reloading of config file.
344 * Removed obsolete SIGHUP support (Unix) and Reload menu option (Win32).
345 * Most of the global variables have been moved to a new
346 * struct configuration_spec, accessed through csp->config->globalname
347 * Most of the globals remaining are used by the Win32 GUI.
349 * Revision 1.5 2001/05/25 22:34:30 jongfoster
352 * Revision 1.4 2001/05/22 18:46:04 oes
354 * - Enabled filtering banners by size rather than URL
355 * by adding patterns that replace all standard banner
356 * sizes with the "Junkbuster" gif to the re_filterfile
358 * - Enabled filtering WebBugs by providing a pattern
359 * which kills all 1x1 images
361 * - Added support for PCRE_UNGREEDY behaviour to pcrs,
362 * which is selected by the (nonstandard and therefore
363 * capital) letter 'U' in the option string.
364 * It causes the quantifiers to be ungreedy by default.
365 * Appending a ? turns back to greedy (!).
367 * - Added a new interceptor ijb-send-banner, which
368 * sends back the "Junkbuster" gif. Without imagelist or
369 * MSIE detection support, or if tinygif = 1, or the
370 * URL isn't recognized as an imageurl, a lame HTML
371 * explanation is sent instead.
373 * - Added new feature, which permits blocking remote
374 * script redirects and firing back a local redirect
376 * The feature is conditionally compiled, i.e. it
377 * can be disabled with --disable-fast-redirects,
378 * plus it must be activated by a "fast-redirects"
379 * line in the config file, has its own log level
380 * and of course wants to be displayed by show-proxy-args
381 * Note: Boy, all the #ifdefs in 1001 locations and
382 * all the fumbling with configure.in and acconfig.h
383 * were *way* more work than the feature itself :-(
385 * - Because a generic redirect template was needed for
386 * this, tinygif = 3 now uses the same.
388 * - Moved GIFs, and other static HTTP response templates
393 * - Removed some >400 CRs again (Jon, you really worked
396 * Revision 1.3 2001/05/20 16:44:47 jongfoster
397 * Removing last hardcoded Junkbusters.com URLs.
399 * Revision 1.2 2001/05/20 01:21:20 jongfoster
400 * Version 2.9.4 checkin.
401 * - Merged popupfile and cookiefile, and added control over PCRS
402 * filtering, in new "permissionsfile".
403 * - Implemented LOG_LEVEL_FATAL, so that if there is a configuration
404 * file error you now get a message box (in the Win32 GUI) rather
405 * than the program exiting with no explanation.
406 * - Made killpopup use the PCRS MIME-type checking and HTTP-header
408 * - Removed tabs from "config"
409 * - Moved duplicated url parsing code in "loaders.c" to a new funcition.
410 * - Bumped up version number.
412 * Revision 1.1.1.1 2001/05/15 13:58:52 oes
413 * Initial import of version 2.9.3 source tree
416 *********************************************************************/
422 #include <sys/types.h>
431 #endif /* ndef __OS2__ */
432 #include <netinet/in.h>
434 #include <winsock2.h>
435 #endif /* ndef _WIN32 */
439 #endif /* def __OS2__ */
447 #include "jbsockets.h"
448 #include "miscutil.h"
452 #include "deanimate.h"
453 #include "urlmatch.h"
459 const char filters_h_rcs[] = FILTERS_H_VERSION;
461 /* Fix a problem with Solaris. There should be no effect on other
463 * Solaris's isspace() is a macro which uses it's argument directly
464 * as an array index. Therefore we need to make sure that high-bit
465 * characters generate +ve values, and ideally we also want to make
466 * the argument match the declared parameter type of "int".
468 #define ijb_isdigit(__X) isdigit((int)(unsigned char)(__X))
472 /*********************************************************************
474 * Function : block_acl
476 * Description : Block this request?
477 * Decide yes or no based on ACL file.
480 * 1 : dst = The proxy or gateway address this is going to.
481 * Or NULL to check all possible targets.
482 * 2 : csp = Current client state (buffers, headers, etc...)
483 * Also includes the client IP address.
485 * Returns : 0 = FALSE (don't block) and 1 = TRUE (do block)
487 *********************************************************************/
488 int block_acl(struct access_control_addr *dst, struct client_state *csp)
490 struct access_control_list *acl = csp->config->acl;
492 /* if not using an access control list, then permit the connection */
498 /* search the list */
501 if ((csp->ip_addr_long & acl->src->mask) == acl->src->addr)
505 /* Just want to check if they have any access */
506 if (acl->action == ACL_PERMIT)
511 else if ( ((dst->addr & acl->dst->mask) == acl->dst->addr)
512 && ((dst->port == acl->dst->port) || (acl->dst->port == 0)))
514 if (acl->action == ACL_PERMIT)
532 /*********************************************************************
534 * Function : acl_addr
536 * Description : Called from `load_config' to parse an ACL address.
539 * 1 : aspec = String specifying ACL address.
540 * 2 : aca = struct access_control_addr to fill in.
542 * Returns : 0 => Ok, everything else is an error.
544 *********************************************************************/
545 int acl_addr(char *aspec, struct access_control_addr *aca)
547 int i, masklength, port;
553 if ((p = strchr(aspec, '/')) != NULL)
557 if (ijb_isdigit(*p) == 0)
561 masklength = atoi(p);
564 if ((masklength < 0) || (masklength > 32))
569 if ((p = strchr(aspec, ':')) != NULL)
573 if (ijb_isdigit(*p) == 0)
582 aca->addr = ntohl(resolve_hostname_to_ip(aspec));
584 if (aca->addr == INADDR_NONE)
589 /* build the netmask */
591 for (i=1; i <= masklength ; i++)
593 aca->mask |= (1 << (32 - i));
596 /* now mask off the host portion of the ip address
597 * (i.e. save on the network portion of the address).
599 aca->addr = aca->addr & aca->mask;
604 #endif /* def FEATURE_ACL */
607 /*********************************************************************
609 * Function : match_portlist
611 * Description : Check if a given number is covered by a comma
612 * separated list of numbers and ranges (a,b-c,d,..)
615 * 1 : portlist = String with list
616 * 2 : port = port to check
618 * Returns : 0 => no match
621 *********************************************************************/
622 int match_portlist(const char *portlist, int port)
624 char *min, *max, *next, *portlist_copy;
626 min = next = portlist_copy = strdup(portlist);
629 * Zero-terminate first item and remember offset for next
631 if (NULL != (next = strchr(portlist_copy, (int) ',')))
637 * Loop through all items, checking for match
641 if (NULL == (max = strchr(min, (int) '-')))
644 * No dash, check for equality
646 if (port == atoi(min))
655 * This is a range, so check if between min and max,
656 * or, if max was omitted, between min and 65K
659 if(port >= atoi(min) && port <= (atoi(max) ? atoi(max) : 65535))
673 * Zero-terminate next item and remember offset for n+1
675 if ((NULL != next) && (NULL != (next = strchr(next, (int) ','))))
687 /*********************************************************************
689 * Function : block_url
691 * Description : Called from `chat'. Check to see if we need to block this.
694 * 1 : csp = Current client state (buffers, headers, etc...)
696 * Returns : NULL => unblocked, else HTTP block response
698 *********************************************************************/
699 struct http_response *block_url(struct client_state *csp)
701 #ifdef FEATURE_IMAGE_BLOCKING
703 #endif /* def FEATURE_IMAGE_BLOCKING */
704 struct http_response *rsp;
707 * If it's not blocked, don't block it ;-)
709 if ((csp->action->flags & ACTION_BLOCK) == 0)
715 * Else, prepare a response
717 if (NULL == (rsp = alloc_http_response()))
719 return cgi_error_memory();
723 * If it's an image-url, send back an image or redirect
724 * as specified by the relevant +image action
726 #ifdef FEATURE_IMAGE_BLOCKING
727 if (((csp->action->flags & ACTION_IMAGE_BLOCKER) != 0)
730 /* determine HOW images should be blocked */
731 p = csp->action->string[ACTION_STRING_IMAGE_BLOCKER];
733 #if 1 /* Two alternative strategies, use this one for now: */
735 /* and handle accordingly: */
736 if ((p == NULL) || (0 == strcmpic(p, "pattern")))
738 rsp->body = bindup(image_pattern_data, image_pattern_length);
739 if (rsp->body == NULL)
741 free_http_response(rsp);
742 return cgi_error_memory();
744 rsp->content_length = image_pattern_length;
746 if (enlist_unique_header(rsp->headers, "Content-Type", BUILTIN_IMAGE_MIMETYPE))
748 free_http_response(rsp);
749 return cgi_error_memory();
753 else if (0 == strcmpic(p, "blank"))
755 rsp->body = bindup(image_blank_data, image_blank_length);
756 if (rsp->body == NULL)
758 free_http_response(rsp);
759 return cgi_error_memory();
761 rsp->content_length = image_blank_length;
763 if (enlist_unique_header(rsp->headers, "Content-Type", BUILTIN_IMAGE_MIMETYPE))
765 free_http_response(rsp);
766 return cgi_error_memory();
772 rsp->status = strdup("302 Local Redirect from Privoxy");
773 if (rsp->status == NULL)
775 free_http_response(rsp);
776 return cgi_error_memory();
779 if (enlist_unique_header(rsp->headers, "Location", p))
781 free_http_response(rsp);
782 return cgi_error_memory();
786 #else /* Following code is disabled for now */
788 /* and handle accordingly: */
789 if ((p == NULL) || (0 == strcmpic(p, "pattern")))
791 p = CGI_PREFIX "send-banner?type=pattern";
793 else if (0 == strcmpic(p, "blank"))
795 p = CGI_PREFIX "send-banner?type=blank";
797 rsp->status = strdup("302 Local Redirect from Privoxy");
798 if (rsp->status == NULL)
800 free_http_response(rsp);
801 return cgi_error_memory();
804 if (enlist_unique_header(rsp->headers, "Location", p))
806 free_http_response(rsp);
807 return cgi_error_memory();
809 #endif /* Preceeding code is disabled for now */
812 #endif /* def FEATURE_IMAGE_BLOCKING */
815 * Else, generate an HTML "blocked" message:
819 struct map * exports;
822 * Workaround for stupid Netscape bug which prevents
823 * pages from being displayed if loading a referenced
824 * JavaScript or style sheet fails. So make it appear
825 * as if it succeeded.
827 if ( NULL != (p = get_header_value(csp->headers, "User-Agent:"))
828 && !strncmpic(p, "mozilla", 7) /* Catch Netscape but */
829 && !strstr(p, "Gecko") /* save Mozilla, */
830 && !strstr(p, "compatible") /* MSIE */
831 && !strstr(p, "Opera")) /* and Opera. */
833 rsp->status = strdup("200 Request for blocked URL");
837 rsp->status = strdup("404 Request for blocked URL");
840 if (rsp->status == NULL)
842 free_http_response(rsp);
843 return cgi_error_memory();
846 exports = default_exports(csp, NULL);
849 free_http_response(rsp);
850 return cgi_error_memory();
853 #ifdef FEATURE_FORCE_LOAD
854 err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
855 if (csp->http->ssl != 0)
856 #endif /* ndef FEATURE_FORCE_LOAD */
858 err = map_block_killer(exports, "force-support");
861 if (!err) err = map(exports, "protocol", 1, csp->http->ssl ? "https://" : "http://", 1);
862 if (!err) err = map(exports, "hostport", 1, html_encode(csp->http->hostport), 0);
863 if (!err) err = map(exports, "path", 1, html_encode(csp->http->path), 0);
864 if (!err) err = map(exports, "path-ue", 1, url_encode(csp->http->path), 0);
869 free_http_response(rsp);
870 return cgi_error_memory();
873 err = template_fill_for_cgi(csp, "blocked", exports, rsp);
876 free_http_response(rsp);
877 return cgi_error_memory();
881 return finish_http_response(rsp);
887 /*********************************************************************
889 * Function : trust_url FIXME: I should be called distrust_url
891 * Description : Calls is_untrusted_url to determine if the URL is trusted
892 * and if not, returns a HTTP 304 response with a reject message.
895 * 1 : csp = Current client state (buffers, headers, etc...)
897 * Returns : NULL => trusted, else http_response.
899 *********************************************************************/
900 struct http_response *trust_url(struct client_state *csp)
902 struct http_response *rsp;
903 struct map * exports;
904 char buf[BUFFER_SIZE];
906 struct url_spec **tl;
911 * Don't bother to work on trusted URLs
913 if (!is_untrusted_url(csp))
919 * Else, prepare a response:
921 if (NULL == (rsp = alloc_http_response()))
923 return cgi_error_memory();
926 exports = default_exports(csp, NULL);
929 free_http_response(rsp);
930 return cgi_error_memory();
934 * Export the protocol, host, port, and referrer information
936 err = map(exports, "hostport", 1, csp->http->hostport, 1);
937 if (!err) err = map(exports, "protocol", 1, csp->http->ssl ? "https://" : "http://", 1);
938 if (!err) err = map(exports, "path", 1, csp->http->path, 1);
940 if (NULL != (p = get_header_value(csp->headers, "Referer:")))
942 if (!err) err = map(exports, "referrer", 1, html_encode(p), 0);
946 if (!err) err = map(exports, "referrer", 1, "unknown", 1);
952 free_http_response(rsp);
953 return cgi_error_memory();
957 * Export the trust list
960 for (tl = csp->config->trust_list; (t = *tl) != NULL ; tl++)
962 sprintf(buf, "<li>%s</li>\n", t->spec);
963 string_append(&p, buf);
965 err = map(exports, "trusted-referrers", 1, p, 0);
970 free_http_response(rsp);
971 return cgi_error_memory();
975 * Export the trust info, if available
977 if (csp->config->trust_info->first)
979 struct list_entry *l;
982 for (l = csp->config->trust_info->first; l ; l = l->next)
984 sprintf(buf, "<li> <a href=\"%s\">%s</a><br>\n",l->str, l->str);
985 string_append(&p, buf);
987 err = map(exports, "trust-info", 1, p, 0);
991 err = map_block_killer(exports, "have-trust-info");
997 free_http_response(rsp);
998 return cgi_error_memory();
1002 * Export the force prefix or the force conditional block killer
1004 #ifdef FEATURE_FORCE_LOAD
1005 err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
1006 #else /* ifndef FEATURE_FORCE_LOAD */
1007 err = map_block_killer(exports, "force-support");
1008 #endif /* ndef FEATURE_FORCE_LOAD */
1013 free_http_response(rsp);
1014 return cgi_error_memory();
1018 * Build the response
1020 err = template_fill_for_cgi(csp, "untrusted", exports, rsp);
1023 free_http_response(rsp);
1024 return cgi_error_memory();
1027 return finish_http_response(rsp);
1029 #endif /* def FEATURE_TRUST */
1032 #ifdef FEATURE_FAST_REDIRECTS
1033 /*********************************************************************
1035 * Function : redirect_url
1037 * Description : Checks for redirection URLs and returns a HTTP redirect
1038 * to the destination URL, if necessary
1041 * 1 : csp = Current client state (buffers, headers, etc...)
1043 * Returns : NULL if URL was clean, HTTP redirect otherwise.
1045 *********************************************************************/
1046 struct http_response *redirect_url(struct client_state *csp)
1049 struct http_response *rsp;
1051 p = q = csp->http->path;
1052 log_error(LOG_LEVEL_REDIRECTS, "checking path for redirects: %s", p);
1055 * find the last URL encoded in the request
1057 while ((p = strstr(p, "http://")) != NULL)
1063 * if there was any, generate and return a HTTP redirect
1065 if (q != csp->http->path)
1067 log_error(LOG_LEVEL_REDIRECTS, "redirecting to: %s", q);
1069 if (NULL == (rsp = alloc_http_response()))
1071 return cgi_error_memory();
1074 if ( enlist_unique_header(rsp->headers, "Location", q)
1075 || (NULL == (rsp->status = strdup("302 Local Redirect from Privoxy"))) )
1077 free_http_response(rsp);
1078 return cgi_error_memory();
1081 return finish_http_response(rsp);
1089 #endif /* def FEATURE_FAST_REDIRECTS */
1092 #ifdef FEATURE_IMAGE_BLOCKING
1093 /*********************************************************************
1095 * Function : is_imageurl
1097 * Description : Given a URL, decide whether it is an image or not,
1098 * using either the info from a previous +image action
1099 * or, #ifdef FEATURE_IMAGE_DETECT_MSIE, and the browser
1100 * is MSIE and not on a Mac, tell from the browser's accept
1104 * 1 : csp = Current client state (buffers, headers, etc...)
1106 * Returns : True (nonzero) if URL is an image, false (0)
1109 *********************************************************************/
1110 int is_imageurl(struct client_state *csp)
1112 #ifdef FEATURE_IMAGE_DETECT_MSIE
1115 tmp = get_header_value(csp->headers, "User-Agent:");
1116 if (tmp && strstr(tmp, "MSIE") && !strstr(tmp, "Mac_"))
1118 tmp = get_header_value(csp->headers, "Accept:");
1119 if (tmp && strstr(tmp, "image/gif"))
1121 /* Client will accept HTML. If this seems counterintuitive,
1131 #endif /* def FEATURE_IMAGE_DETECT_MSIE */
1133 return ((csp->action->flags & ACTION_IMAGE) != 0);
1136 #endif /* def FEATURE_IMAGE_BLOCKING */
1139 #ifdef FEATURE_TRUST
1140 /*********************************************************************
1142 * Function : is_untrusted_url
1144 * Description : Should we "distrust" this URL (and block it)?
1146 * Yes if it matches a line in the trustfile, or if the
1147 * referrer matches a line starting with "+" in the
1152 * 1 : csp = Current client state (buffers, headers, etc...)
1154 * Returns : 0 => trusted, 1 => untrusted
1156 *********************************************************************/
1157 int is_untrusted_url(struct client_state *csp)
1159 struct file_list *fl;
1160 struct block_spec *b;
1161 struct url_spec **trusted_url;
1162 struct http_request rhttp[1];
1163 const char * referer;
1167 * If we don't have a trustlist, we trust everybody
1169 if (((fl = csp->tlist) == NULL) || ((b = fl->f) == NULL))
1174 memset(rhttp, '\0', sizeof(*rhttp));
1177 * Do we trust the request URL itself?
1179 for (b = b->next; b ; b = b->next)
1181 if (url_match(b->url, csp->http))
1187 if (NULL == (referer = get_header_value(csp->headers, "Referer:")))
1189 /* no referrer was supplied */
1195 * If not, do we maybe trust its referrer?
1197 err = parse_http_url(referer, rhttp, csp);
1203 for (trusted_url = csp->config->trust_list; *trusted_url != NULL; trusted_url++)
1205 if (url_match(*trusted_url, rhttp))
1207 /* if the URL's referrer is from a trusted referrer, then
1208 * add the target spec to the trustfile as an unblocked
1209 * domain and return NULL (which means it's OK).
1214 if (NULL != (fp = fopen(csp->config->trustfile, "a")))
1218 char * new_entry = strdup("~");
1220 string_append(&new_entry, csp->http->hostport);
1222 path = csp->http->path;
1223 if ( (path[0] == '/')
1225 && ((path_end = strchr(path + 2, '/')) != NULL))
1227 /* since this path points into a user's home space
1228 * be sure to include this spec in the trustfile.
1230 int path_len = path_end - path; /* save offset */
1231 path = strdup(path); /* Copy string */
1234 path_end = path + path_len; /* regenerate ptr to new buffer */
1235 *(path_end + 1) = '\0'; /* Truncate path after '/' */
1237 string_join(&new_entry, path);
1240 if (new_entry != NULL)
1242 fprintf(fp, "%s\n", new_entry);
1247 /* FIXME: No way to handle out-of memory, so mostly ignoring it */
1248 log_error(LOG_LEVEL_ERROR, "Out of memory adding pattern to trust file");
1258 #endif /* def FEATURE_TRUST */
1261 /*********************************************************************
1263 * Function : pcrs_filter_response
1265 * Description : Execute all text substitutions from all applying
1266 * +filter actions on the text buffer that's been accumulated
1267 * in csp->iob->buf. If this changes the contents, set
1268 * csp->content_length to the modified size and raise the
1269 * CSP_FLAG_MODIFIED flag.
1272 * 1 : csp = Current client state (buffers, headers, etc...)
1274 * Returns : a pointer to the (newly allocated) modified buffer.
1275 * or NULL if there were no hits or something went wrong
1277 *********************************************************************/
1278 char *pcrs_filter_response(struct client_state *csp)
1283 char *old = csp->iob->cur, *new = NULL;
1286 struct file_list *fl;
1287 struct re_filterfile_spec *b;
1288 struct list_entry *filtername;
1293 if (csp->iob->cur >= csp->iob->eod)
1297 size = csp->iob->eod - csp->iob->cur;
1299 if ( ( NULL == (fl = csp->rlist) ) || ( NULL == fl->f) )
1301 log_error(LOG_LEVEL_ERROR, "Unable to get current state of regexp filtering.");
1306 * If the body has a "chunked" transfer-encoding,
1307 * get rid of it first, adjusting size and iob->eod
1309 if (csp->flags & CSP_FLAG_CHUNKED)
1311 log_error(LOG_LEVEL_RE_FILTER, "Need to de-chunk first");
1312 if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
1316 csp->iob->eod = csp->iob->cur + size;
1317 csp->flags |= CSP_FLAG_MODIFIED;
1321 * For all applying +filter actions, look if a filter by that
1322 * name exists and if yes, execute it's pcrs_joblist on the
1325 for (b = fl->f; b; b = b->next)
1327 for (filtername = csp->action->multi[ACTION_MULTI_FILTER]->first;
1328 filtername ; filtername = filtername->next)
1330 if (strcmp(b->name, filtername->str) == 0)
1332 int current_hits = 0;
1334 if ( NULL == b->joblist )
1336 log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name);
1340 log_error(LOG_LEVEL_RE_FILTER, "re_filtering %s%s (size %d) with filter %s...",
1341 csp->http->hostport, csp->http->path, size, b->name);
1343 /* Apply all jobs from the joblist */
1344 for (job = b->joblist; NULL != job; job = job->next)
1346 current_hits += pcrs_execute(job, old, size, &new, &size);
1347 if (old != csp->iob->cur) free(old);
1351 log_error(LOG_LEVEL_RE_FILTER, " ...produced %d hits (new size %d).", current_hits, size);
1352 hits += current_hits;
1358 * If there were no hits, destroy our copy and let
1359 * chat() use the original in csp->iob
1367 csp->flags |= CSP_FLAG_MODIFIED;
1368 csp->content_length = size;
1376 /*********************************************************************
1378 * Function : gif_deanimate_response
1380 * Description : Deanimate the GIF image that has been accumulated in
1381 * csp->iob->buf, set csp->content_length to the modified
1382 * size and raise the CSP_FLAG_MODIFIED flag.
1385 * 1 : csp = Current client state (buffers, headers, etc...)
1387 * Returns : a pointer to the (newly allocated) modified buffer.
1388 * or NULL in case something went wrong.
1390 *********************************************************************/
1391 char *gif_deanimate_response(struct client_state *csp)
1393 struct binbuffer *in, *out;
1395 size_t size = csp->iob->eod - csp->iob->cur;
1398 * If the body has a "chunked" transfer-encoding,
1399 * get rid of it first, adjusting size and iob->eod
1401 if (csp->flags & CSP_FLAG_CHUNKED)
1403 log_error(LOG_LEVEL_DEANIMATE, "Need to de-chunk first");
1404 if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
1408 csp->iob->eod = csp->iob->cur + size;
1409 csp->flags |= CSP_FLAG_MODIFIED;
1412 if ( (NULL == (in = (struct binbuffer *)zalloc(sizeof *in )))
1413 || (NULL == (out = (struct binbuffer *)zalloc(sizeof *out))) )
1415 log_error(LOG_LEVEL_DEANIMATE, "failed! (no mem)");
1419 in->buffer = csp->iob->cur;
1422 if (gif_deanimate(in, out, strncmp("last", csp->action->string[ACTION_STRING_DEANIMATE], 4)))
1424 log_error(LOG_LEVEL_DEANIMATE, "failed! (gif parsing)");
1431 if ((int)size == out->offset)
1433 log_error(LOG_LEVEL_DEANIMATE, "GIF not changed.");
1437 log_error(LOG_LEVEL_DEANIMATE, "Success! GIF shrunk from %d bytes to %d.", size, out->offset);
1439 csp->content_length = out->offset;
1440 csp->flags |= CSP_FLAG_MODIFIED;
1450 /*********************************************************************
1452 * Function : remove_chunked_transfer_coding
1454 * Description : In-situ remove the "chunked" transfer coding as defined
1455 * in rfc2616 from a buffer.
1458 * 1 : buffer = Pointer to the text buffer
1459 * 2 : size = Number of bytes to be processed
1461 * Returns : The new size, i.e. the number of bytes from buffer which
1462 * are occupied by the stripped body, or 0 in case something
1465 *********************************************************************/
1466 int remove_chunked_transfer_coding(char *buffer, const size_t size)
1469 unsigned int chunksize = 0;
1470 char *from_p, *to_p;
1473 from_p = to_p = buffer;
1475 if (sscanf(buffer, "%x", &chunksize) != 1)
1477 log_error(LOG_LEVEL_ERROR, "Invalid first chunksize while stripping \"chunked\" transfer coding");
1481 while (chunksize > 0)
1483 if (NULL == (from_p = strstr(from_p, "\r\n")))
1485 log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding");
1489 if ((newsize += chunksize) >= size)
1491 log_error(LOG_LEVEL_ERROR, "Chunksize exceeds buffer in \"chunked\" transfer coding");
1496 memmove(to_p, from_p, (size_t) chunksize);
1497 to_p = buffer + newsize;
1498 from_p += chunksize + 2;
1500 if (sscanf(from_p, "%x", &chunksize) != 1)
1502 log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding");
1507 /* FIXME: Should this get its own loglevel? */
1508 log_error(LOG_LEVEL_RE_FILTER, "De-chunking successful. Shrunk from %d to %d\n", size, newsize);
1514 /*********************************************************************
1516 * Function : url_actions
1518 * Description : Gets the actions for this URL.
1521 * 1 : http = http_request request for blocked URLs
1522 * 2 : csp = Current client state (buffers, headers, etc...)
1526 *********************************************************************/
1527 void url_actions(struct http_request *http,
1528 struct client_state *csp)
1530 struct file_list *fl;
1531 struct url_actions *b;
1534 init_current_action(csp->action);
1536 for (i = 0; i < MAX_ACTION_FILES; i++)
1538 if (((fl = csp->actions_list[i]) == NULL) || ((b = fl->f) == NULL))
1543 apply_url_actions(csp->action, http, b);
1550 /*********************************************************************
1552 * Function : apply_url_actions
1554 * Description : Applies a list of URL actions.
1557 * 1 : action = Destination.
1558 * 2 : http = Current URL
1559 * 3 : b = list of URL actions to apply
1563 *********************************************************************/
1564 void apply_url_actions(struct current_action_spec *action,
1565 struct http_request *http,
1566 struct url_actions *b)
1570 /* Should never happen */
1574 for (b = b->next; NULL != b; b = b->next)
1576 if (url_match(b->url, http))
1578 merge_current_action(action, b->action);
1584 /*********************************************************************
1586 * Function : forward_url
1588 * Description : Should we forward this to another proxy?
1591 * 1 : http = http_request request for current URL
1592 * 2 : csp = Current client state (buffers, headers, etc...)
1594 * Returns : Pointer to forwarding information.
1596 *********************************************************************/
1597 const struct forward_spec * forward_url(struct http_request *http,
1598 struct client_state *csp)
1600 static const struct forward_spec fwd_default[1] = { FORWARD_SPEC_INITIALIZER };
1601 struct forward_spec *fwd = csp->config->forward;
1610 if (url_match(fwd->url, http))
1621 /*********************************************************************
1623 * Function : direct_response
1625 * Description : Check if Max-Forwards == 0 for an OPTIONS or TRACE
1626 * request and if so, return a HTTP 501 to the client.
1628 * FIXME: I have a stupid name and I should handle the
1629 * requests properly. Still, what we do here is rfc-
1630 * compliant, whereas ignoring or forwarding are not.
1633 * 1 : csp = Current client state (buffers, headers, etc...)
1635 * Returns : http_response if , NULL if nonmatch or handler fail
1637 *********************************************************************/
1638 struct http_response *direct_response(struct client_state *csp)
1640 struct http_response *rsp;
1641 struct list_entry *p;
1643 if ((0 == strcmpic(csp->http->gpc, "trace"))
1644 || (0 == strcmpic(csp->http->gpc, "options")))
1646 for (p = csp->headers->first; (p != NULL) ; p = p->next)
1648 if (!strncmp("Max-Forwards:", p->str, 13)
1649 && (*(p->str+13) != '\0') && (atoi(p->str+13) == 0))
1651 /* FIXME: We could handle at least TRACE here,
1652 but that would require a verbatim copy of
1653 the request which we don't have anymore */
1655 log_error(LOG_LEVEL_HEADER, "Found Max-Forwards:0 in OPTIONS or TRACE request -- Returning 501");
1657 /* Get mem for response or fail*/
1658 if (NULL == (rsp = alloc_http_response()))
1660 return cgi_error_memory();
1663 if (NULL == (rsp->status = strdup("501 Not Implemented")))
1665 free_http_response(rsp);
1666 return cgi_error_memory();
1670 return(finish_http_response(rsp));