const char parsers_rcs[] = "$Id: parsers.c,v 1.120 2008/01/04 17:43:45 fabiankeil Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/parsers.c,v $ * * Purpose : Declares functions to parse/crunch headers and pages. * Functions declared include: * `add_to_iob', `client_cookie_adder', `client_from', * `client_referrer', `client_send_cookie', `client_ua', * `client_uagent', `client_x_forwarded', * `client_x_forwarded_adder', `client_xtra_adder', * `content_type', `crumble', `destroy_list', `enlist', * `flush_socket', ``get_header', `sed', `filter_header' * `server_content_encoding', `server_content_disposition', * `server_last_modified', `client_accept_language', * `crunch_client_header', `client_if_modified_since', * `client_if_none_match', `get_destination_from_headers', * `parse_header_time', `decompress_iob' and `server_set_cookie'. * * Copyright : Written by and Copyright (C) 2001-2007 the SourceForge * Privoxy team. http://www.privoxy.org/ * * Based on the Internet Junkbuster originally written * by and Copyright (C) 1997 Anonymous Coders and * Junkbusters Corporation. http://www.junkbusters.com * * This program is free software; you can redistribute it * and/or modify it under the terms of the GNU General * Public License as published by the Free Software * Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will * be useful, but WITHOUT ANY WARRANTY; without even the * implied warranty of MERCHANTABILITY or FITNESS FOR A * PARTICULAR PURPOSE. See the GNU General Public * License for more details. * * The GNU General Public License should be included with * this file. If not, you can view it at * http://www.gnu.org/copyleft/gpl.html * or write to the Free Software Foundation, Inc., 59 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Revisions : * $Log: parsers.c,v $ * Revision 1.120 2008/01/04 17:43:45 fabiankeil * Improve the warning messages that get logged if the action files * "enable" filters but no filters of that type have been loaded. * * Revision 1.119 2007/12/28 18:32:51 fabiankeil * In server_content_type(): * - Don't require leading white space when detecting image content types. * - Change '... not replaced ...' message to sound less crazy if the text * type actually is 'text/plain'. * - Mark the 'text/plain == binary data' assumption for removal. * - Remove a bunch of trailing white space. * * Revision 1.118 2007/12/28 16:56:35 fabiankeil * Minor server_content_disposition() changes: * - Don't regenerate the header name all lower-case. * - Some white space fixes. * - Remove useless log message in case of ENOMEM. * * Revision 1.117 2007/12/06 18:11:50 fabiankeil * Garbage-collect the code to add a X-Forwarded-For * header as it seems to be mostly used by accident. * * Revision 1.116 2007/12/01 13:04:22 fabiankeil * Fix a crash on mingw32 with some Last Modified times in the future. * * Revision 1.115 2007/11/02 16:52:50 fabiankeil * Remove a "can't happen" error block which, over * time, mutated into a "guaranteed to happen" block. * * Revision 1.114 2007/10/19 16:56:26 fabiankeil * - Downgrade "Buffer limit reached" message to LOG_LEVEL_INFO. * - Use shiny new content_filters_enabled() in client_range(). * * Revision 1.113 2007/10/10 17:29:57 fabiankeil * I forgot about Poland. * * Revision 1.112 2007/10/09 16:38:40 fabiankeil * Remove Range and If-Range headers if content filtering is enabled. * * Revision 1.111 2007/10/04 18:07:00 fabiankeil * Move ACTION_VANILLA_WAFER handling from jcc's chat() into * client_cookie_adder() to make sure send-vanilla-wafer can be * controlled through tags (and thus regression-tested). * * Revision 1.110 2007/09/29 10:42:37 fabiankeil * - Remove "scanning headers for" log message again. * - Some more whitespace fixes. * * Revision 1.109 2007/09/08 14:25:48 fabiankeil * Refactor client_referrer() and add conditional-forge parameter. * * Revision 1.108 2007/08/28 18:21:03 fabiankeil * A bunch of whitespace fixes, pointy hat to me. * * Revision 1.107 2007/08/28 18:16:32 fabiankeil * Fix possible memory corruption in server_http, make sure it's not * executed for ordinary server headers and mark some problems for later. * * Revision 1.106 2007/08/18 14:30:32 fabiankeil * Let content-type-overwrite{} honour force-text-mode again. * * Revision 1.105 2007/08/11 14:49:49 fabiankeil * - Add prototpyes for the header parsers and make them static. * - Comment out client_accept_encoding_adder() which isn't used right now. * * Revision 1.104 2007/07/14 07:38:19 fabiankeil * Move the ACTION_FORCE_TEXT_MODE check out of * server_content_type(). Signal other functions * whether or not a content type has been declared. * Part of the fix for BR#1750917. * * Revision 1.103 2007/06/01 16:31:54 fabiankeil * Change sed() to return a jb_err in preparation for forward-override{}. * * Revision 1.102 2007/05/27 12:39:32 fabiankeil * Adjust "X-Filter: No" to disable dedicated header filters. * * Revision 1.101 2007/05/14 10:16:41 fabiankeil * Streamline client_cookie_adder(). * * Revision 1.100 2007/04/30 15:53:11 fabiankeil * Make sure filters with dynamic jobs actually use them. * * Revision 1.99 2007/04/30 15:06:26 fabiankeil * - Introduce dynamic pcrs jobs that can resolve variables. * - Remove unnecessary update_action_bits_for_all_tags() call. * * Revision 1.98 2007/04/17 18:32:10 fabiankeil * - Make tagging based on tags set by earlier taggers * of the same kind possible. * - Log whether or not new tags cause action bits updates * (in which case a matching tag-pattern section exists). * - Log if the user tries to set a tag that is already set. * * Revision 1.97 2007/04/15 16:39:21 fabiankeil * Introduce tags as alternative way to specify which * actions apply to a request. At the moment tags can be * created based on client and server headers. * * Revision 1.96 2007/04/12 12:53:58 fabiankeil * Log a warning if the content is compressed, filtering is * enabled and Privoxy was compiled without zlib support. * Closes FR#1673938. * * Revision 1.95 2007/03/25 14:26:40 fabiankeil * - Fix warnings when compiled with glibc. * - Don't use crumble() for cookie crunching. * - Move cookie time parsing into parse_header_time(). * - Let parse_header_time() return a jb_err code * instead of a pointer that can only be used to * check for NULL anyway. * * Revision 1.94 2007/03/21 12:23:53 fabiankeil * - Add better protection against malicious gzip headers. * - Stop logging the first hundred bytes of decompressed content. * It looks like it's working and there is always debug 16. * - Log the content size after decompression in decompress_iob() * instead of pcrs_filter_response(). * * Revision 1.93 2007/03/20 15:21:44 fabiankeil * - Use dedicated header filter actions instead of abusing "filter". * Replace "filter-client-headers" and "filter-client-headers" * with "server-header-filter" and "client-header-filter". * - Remove filter_client_header() and filter_client_header(), * filter_header() now checks the shiny new * CSP_FLAG_CLIENT_HEADER_PARSING_DONE flag instead. * * Revision 1.92 2007/03/05 13:25:32 fabiankeil * - Cosmetical changes for LOG_LEVEL_RE_FILTER messages. * - Handle "Cookie:" and "Connection:" headers a bit smarter * (don't crunch them just to recreate them later on). * - Add another non-standard time format for the cookie * expiration date detection. * - Fix a valgrind warning. * * Revision 1.91 2007/02/24 12:27:32 fabiankeil * Improve cookie expiration date detection. * * Revision 1.90 2007/02/08 19:12:35 fabiankeil * Don't run server_content_length() the first time * sed() parses server headers; only adjust the * Content-Length header if the page was modified. * * Revision 1.89 2007/02/07 16:52:11 fabiankeil * Fix log messages regarding the cookie time format * (cookie and request URL were mixed up). * * Revision 1.88 2007/02/07 11:27:12 fabiankeil * - Let decompress_iob() * - not corrupt the content if decompression fails * early. (the first byte(s) were lost). * - use pointer arithmetics with defined outcome for * a change. * - Use a different kludge to remember a failed decompression. * * Revision 1.87 2007/01/31 16:21:38 fabiankeil * Search for Max-Forwards headers case-insensitive, * don't generate the "501 unsupported" message for invalid * Max-Forwards values and don't increase negative ones. * * Revision 1.86 2007/01/30 13:05:26 fabiankeil * - Let server_set_cookie() check the expiration date * of cookies and don't touch the ones that are already * expired. Fixes problems with low quality web applications * as described in BR 932612. * * - Adjust comment in client_max_forwards to reality; * remove invalid Max-Forwards headers. * * Revision 1.85 2007/01/26 15:33:46 fabiankeil * Stop filter_header() from unintentionally removing * empty header lines that were enlisted by the continue * hack. * * Revision 1.84 2007/01/24 12:56:52 fabiankeil * - Repeat the request URL before logging any headers. * Makes reading the log easier in case of simultaneous requests. * - If there are more than one Content-Type headers in one request, * use the first one and remove the others. * - Remove "newval" variable in server_content_type(). * It's only used once. * * Revision 1.83 2007/01/12 15:03:02 fabiankeil * Correct a cast, check inflateEnd() exit code * to see if we have to, replace sprintf calls * with snprintf. * * Revision 1.82 2007/01/01 19:36:37 fabiankeil * Integrate a modified version of Wil Mahan's * zlib patch (PR #895531). * * Revision 1.81 2006/12/31 22:21:33 fabiankeil * Skip empty filter files in filter_header() * but don't ignore the ones that come afterwards. * Fixes BR 1619208, this time for real. * * Revision 1.80 2006/12/29 19:08:22 fabiankeil * Reverted parts of my last commit * to keep error handling working. * * Revision 1.79 2006/12/29 18:04:40 fabiankeil * Fixed gcc43 conversion warnings. * * Revision 1.78 2006/12/26 17:19:20 fabiankeil * Bringing back the "useless" localtime() call * I removed in revision 1.67. On some platforms * it's necessary to prevent time zone offsets. * * Revision 1.77 2006/12/07 18:44:26 fabiankeil * Rebuild request URL in get_destination_from_headers() * to make sure redirect{pcrs command} works as expected * for intercepted requests. * * Revision 1.76 2006/12/06 19:52:25 fabiankeil * Added get_destination_from_headers(). * * Revision 1.75 2006/11/13 19:05:51 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 1.74 2006/10/02 16:59:12 fabiankeil * The special header "X-Filter: No" now disables * header filtering as well. * * Revision 1.73 2006/09/23 13:26:38 roro * Replace TABs by spaces in source code. * * Revision 1.72 2006/09/23 12:37:21 fabiankeil * Don't print a log message every time filter_headers is * entered or left. It only creates noise without any real * information. * * Revision 1.71 2006/09/21 19:55:17 fabiankeil * Fix +hide-if-modified-since{-n}. * * Revision 1.70 2006/09/08 12:06:34 fabiankeil * Have hide-if-modified-since interpret the random * range value as minutes instead of hours. Allows * more fine-grained configuration. * * Revision 1.69 2006/09/06 16:25:51 fabiankeil * Always have parse_header_time return a pointer * that actual makes sense, even though we currently * only need it to detect problems. * * Revision 1.68 2006/09/06 10:43:32 fabiankeil * Added config option enable-remote-http-toggle * to specify if Privoxy should recognize special * headers (currently only X-Filter) to change its * behaviour. Disabled by default. * * Revision 1.67 2006/09/04 11:01:26 fabiankeil * After filtering de-chunked instances, remove * "Transfer-Encoding" header entirely instead of changing * it to "Transfer-Encoding: identity", which is invalid. * Thanks Michael Shields . Fixes PR 1318658. * * Don't use localtime in parse_header_time. An empty time struct * is good enough, it gets overwritten by strptime anyway. * * Revision 1.66 2006/09/03 19:38:28 fabiankeil * Use gmtime_r if available, fallback to gmtime with mutex * protection for MacOSX and use vanilla gmtime for the rest. * * Revision 1.65 2006/08/22 10:55:56 fabiankeil * Changed client_referrer to use the right type (size_t) for * hostlenght and to shorten the temporary referrer string with * '\0' instead of adding a useless line break. * * Revision 1.64 2006/08/17 17:15:10 fabiankeil * - Back to timegm() using GnuPG's replacement if necessary. * Using mktime() and localtime() could add a on hour offset if * the randomize factor was big enough to lead to a summer/wintertime * switch. * * - Removed now-useless Privoxy 3.0.3 compatibility glue. * * - Moved randomization code into pick_from_range(). * * - Changed parse_header_time definition. * time_t isn't guaranteed to be signed and * if it isn't, -1 isn't available as error code. * Changed some variable types in client_if_modified_since() * because of the same reason. * * Revision 1.63 2006/08/14 13:18:08 david__schmidt * OS/2 compilation compatibility fixups * * Revision 1.62 2006/08/14 08:58:42 fabiankeil * Changed include from strptime.c to strptime.h * * Revision 1.61 2006/08/14 08:25:19 fabiankeil * Split filter-headers{} into filter-client-headers{} * and filter-server-headers{}. * Added parse_header_time() to share some code. * Replaced timegm() with mktime(). * * Revision 1.60 2006/08/12 03:54:37 david__schmidt * Windows service integration * * Revision 1.59 2006/08/03 02:46:41 david__schmidt * Incorporate Fabian Keil's patch work: http://www.fabiankeil.de/sourcecode/privoxy/ * * Revision 1.58 2006/07/18 14:48:47 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 1.56.2.10 2006/01/21 16:16:08 david__schmidt * Thanks to Edward Carrel for his patch to modernize OSX's pthreads support. See bug #1409623. * * Revision 1.56.2.9 2004/10/03 12:53:45 david__schmidt * Add the ability to check jpeg images for invalid * lengths of comment blocks. Defensive strategy * against the exploit: * Microsoft Security Bulletin MS04-028 * Buffer Overrun in JPEG Processing (GDI+) Could * Allow Code Execution (833987) * Enabled with +inspect-jpegs in actions files. * * Revision 1.56.2.8 2003/07/11 13:21:25 oes * Excluded text/plain objects from filtering. This fixes a * couple of client-crashing, download corruption and * Privoxy performance issues, whose root cause lies in * web servers labelling content of unknown type as text/plain. * * Revision 1.56.2.7 2003/05/06 12:07:26 oes * Fixed bug #729900: Suspicious HOST: headers are now killed and regenerated if necessary * * Revision 1.56.2.6 2003/04/14 21:28:30 oes * Completing the previous change * * Revision 1.56.2.5 2003/04/14 12:08:16 oes * Added temporary workaround for bug in PHP < 4.2.3 * * Revision 1.56.2.4 2003/03/07 03:41:05 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 1.56.2.3 2002/11/10 04:20:02 hal9 * Fix typo: supressed -> suppressed * * Revision 1.56.2.2 2002/09/25 14:59:53 oes * Improved cookie logging * * Revision 1.56.2.1 2002/09/25 14:52:45 oes * Added basic support for OPTIONS and TRACE HTTP methods: * - New parser function client_max_forwards which decrements * the Max-Forwards HTTP header field of OPTIONS and TRACE * requests by one before forwarding * - New parser function client_host which extracts the host * and port information from the HTTP header field if the * request URI was not absolute * - Don't crumble and re-add the Host: header, but only generate * and append if missing * * Revision 1.56 2002/05/12 15:34:22 jongfoster * Fixing typo in a comment * * Revision 1.55 2002/05/08 16:01:07 oes * Optimized add_to_iob: * - Use realloc instead of malloc(), memcpy(), free() * - Expand to powers of two if possible, to get * O(log n) reallocs instead of O(n). * - Moved check for buffer limit here from chat * - Report failure via returncode * * Revision 1.54 2002/04/02 15:03:16 oes * Tiny code cosmetics * * Revision 1.53 2002/03/26 22:29:55 swa * we have a new homepage! * * Revision 1.52 2002/03/24 13:25:43 swa * name change related issues * * Revision 1.51 2002/03/13 00:27:05 jongfoster * Killing warnings * * Revision 1.50 2002/03/12 01:45:35 oes * More verbose logging * * Revision 1.49 2002/03/09 20:03:52 jongfoster * - Making various functions return int rather than size_t. * (Undoing a recent change). Since size_t is unsigned on * Windows, functions like read_socket that return -1 on * error cannot return a size_t. * * THIS WAS A MAJOR BUG - it caused frequent, unpredictable * crashes, and also frequently caused JB to jump to 100% * CPU and stay there. (Because it thought it had just * read ((unsigned)-1) == 4Gb of data...) * * - The signature of write_socket has changed, it now simply * returns success=0/failure=nonzero. * * - Trying to get rid of a few warnings --with-debug on * Windows, I've introduced a new type "jb_socket". This is * used for the socket file descriptors. On Windows, this * is SOCKET (a typedef for unsigned). Everywhere else, it's * an int. The error value can't be -1 any more, so it's * now JB_INVALID_SOCKET (which is -1 on UNIX, and in * Windows it maps to the #define INVALID_SOCKET.) * * - The signature of bind_port has changed. * * Revision 1.48 2002/03/07 03:46:53 oes * Fixed compiler warnings etc * * Revision 1.47 2002/02/20 23:15:13 jongfoster * Parsing functions now handle out-of-memory gracefully by returning * an error code. * * Revision 1.46 2002/01/17 21:03:47 jongfoster * Moving all our URL and URL pattern parsing code to urlmatch.c. * * Revision 1.45 2002/01/09 14:33:03 oes * Added support for localtime_r. * * Revision 1.44 2001/12/14 01:22:54 steudten * Remove 'user:pass@' from 'proto://user:pass@host' for the * new added header 'Host: ..'. (See Req ID 491818) * * Revision 1.43 2001/11/23 00:26:38 jongfoster * Fixing two really stupid errors in my previous commit * * Revision 1.42 2001/11/22 21:59:30 jongfoster * Adding code to handle +no-cookies-keep * * Revision 1.41 2001/11/05 23:43:05 steudten * Add time+date to log files. * * Revision 1.40 2001/10/26 20:13:09 jongfoster * ctype.h is needed in Windows, too. * * Revision 1.39 2001/10/26 17:40:04 oes * Introduced get_header_value() * Removed http->user_agent, csp->referrer and csp->accept_types * Removed client_accept() * * Revision 1.38 2001/10/25 03:40:48 david__schmidt * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple * threads to call select() simultaneously. So, it's time to do a real, live, * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__ * (native). Both versions will work, but using __OS2__ offers multi-threading. * * Revision 1.37 2001/10/23 21:36:02 jongfoster * Documenting sed()'s error behaviou (doc change only) * * Revision 1.36 2001/10/13 12:51:51 joergs * Removed client_host, (was only required for the old 2.0.2-11 http://noijb. * force-load), instead crumble Host: and add it (again) in client_host_adder * (in case we get a HTTP/1.0 request without Host: header and forward it to * a HTTP/1.1 server/proxy). * * Revision 1.35 2001/10/09 22:39:21 jongfoster * assert.h is also required under Win32, so moving out of #ifndef _WIN32 * block. * * Revision 1.34 2001/10/07 18:50:55 oes * Added server_content_encoding, renamed server_transfer_encoding * * Revision 1.33 2001/10/07 18:04:49 oes * Changed server_http11 to server_http and its pattern to "HTTP". * Additional functionality: it now saves the HTTP status into * csp->http->status and sets CT_TABOO for Status 206 (partial range) * * Revision 1.32 2001/10/07 15:43:28 oes * Removed FEATURE_DENY_GZIP and replaced it with client_accept_encoding, * client_te and client_accept_encoding_adder, triggered by the new * +no-compression action. For HTTP/1.1 the Accept-Encoding header is * changed to allow only identity and chunked, and the TE header is * crunched. For HTTP/1.0, Accept-Encoding is crunched. * * parse_http_request no longer does anything than parsing. The rewriting * of http->cmd and version mangling are gone. It now also recognizes * the put and delete methods and saves the url in http->url. Removed * unused variable. * * renamed content_type and content_length to have the server_ prefix * * server_content_type now only works if csp->content_type != CT_TABOO * * added server_transfer_encoding, which * - Sets CT_TABOO to prohibit filtering if encoding compresses * - Raises the CSP_FLAG_CHUNKED flag if Encoding is "chunked" * - Change from "chunked" to "identity" if body was chunked * but has been de-chunked for filtering. * * added server_content_md5 which crunches any Content-MD5 headers * if the body was modified. * * made server_http11 conditional on +downgrade action * * Replaced 6 boolean members of csp with one bitmap (csp->flags) * * Revision 1.31 2001/10/05 14:25:02 oes * Crumble Keep-Alive from Server * * Revision 1.30 2001/09/29 12:56:03 joergs * IJB now changes HTTP/1.1 to HTTP/1.0 in requests and answers. * * Revision 1.29 2001/09/24 21:09:24 jongfoster * Fixing 2 memory leaks that Guy spotted, where the paramater to * enlist() was not being free()d. * * Revision 1.28 2001/09/22 16:32:28 jongfoster * Removing unused #includes. * * Revision 1.27 2001/09/20 15:45:25 steudten * * add casting from size_t to int for printf() * remove local variable shadow s2 * * Revision 1.26 2001/09/16 17:05:14 jongfoster * Removing unused #include showarg.h * * Revision 1.25 2001/09/16 13:21:27 jongfoster * Changes to use new list functions. * * Revision 1.24 2001/09/13 23:05:50 jongfoster * Changing the string paramater to the header parsers a "const". * * Revision 1.23 2001/09/12 18:08:19 steudten * * In parse_http_request() header rewriting miss the host value, so * from http://www.mydomain.com the result was just " / " not * http://www.mydomain.com/ in case we forward. * * Revision 1.22 2001/09/10 10:58:53 oes * Silenced compiler warnings * * Revision 1.21 2001/07/31 14:46:00 oes * - Persistant connections now suppressed * - sed() no longer appends empty header to csp->headers * * Revision 1.20 2001/07/30 22:08:36 jongfoster * Tidying up #defines: * - All feature #defines are now of the form FEATURE_xxx * - Permanently turned off WIN_GUI_EDIT * - Permanently turned on WEBDAV and SPLIT_PROXY_ARGS * * Revision 1.19 2001/07/25 17:21:54 oes * client_uagent now saves copy of User-Agent: header value * * Revision 1.18 2001/07/13 14:02:46 oes * - Included fix to repair broken HTTP requests that * don't contain a path, not even '/'. * - Removed all #ifdef PCRS * - content_type now always inspected and classified as * text, gif or other. * - formatting / comments * * Revision 1.17 2001/06/29 21:45:41 oes * Indentation, CRLF->LF, Tab-> Space * * Revision 1.16 2001/06/29 13:32:42 oes * - Fixed a comment * - Adapted free_http_request * - Removed logentry from cancelled commit * * Revision 1.15 2001/06/03 19:12:38 oes * deleted const struct interceptors * * Revision 1.14 2001/06/01 18:49:17 jongfoster * Replaced "list_share" with "list" - the tiny memory gain was not * worth the extra complexity. * * Revision 1.13 2001/05/31 21:30:33 jongfoster * Removed list code - it's now in list.[ch] * Renamed "permission" to "action", and changed many features * to use the actions file rather than the global config. * * Revision 1.12 2001/05/31 17:33:13 oes * * CRLF -> LF * * Revision 1.11 2001/05/29 20:11:19 joergs * '/ * inside comment' warning removed. * * Revision 1.10 2001/05/29 09:50:24 jongfoster * Unified blocklist/imagelist/permissionslist. * File format is still under discussion, but the internal changes * are (mostly) done. * * Also modified interceptor behaviour: * - We now intercept all URLs beginning with one of the following * prefixes (and *only* these prefixes): * * http://i.j.b/ * * http://ijbswa.sf.net/config/ * * http://ijbswa.sourceforge.net/config/ * - New interceptors "home page" - go to http://i.j.b/ to see it. * - Internal changes so that intercepted and fast redirect pages * are not replaced with an image. * - Interceptors now have the option to send a binary page direct * to the client. (i.e. ijb-send-banner uses this) * - Implemented show-url-info interceptor. (Which is why I needed * the above interceptors changes - a typical URL is * "http://i.j.b/show-url-info?url=www.somesite.com/banner.gif". * The previous mechanism would not have intercepted that, and * if it had been intercepted then it then it would have replaced * it with an image.) * * Revision 1.9 2001/05/28 17:26:33 jongfoster * Fixing segfault if last header was crunched. * Fixing Windows build (snprintf() is _snprintf() under Win32, but we * can use the cross-platform sprintf() instead.) * * Revision 1.8 2001/05/27 22:17:04 oes * * - re_process_buffer no longer writes the modified buffer * to the client, which was very ugly. It now returns the * buffer, which it is then written by chat. * * - content_length now adjusts the Content-Length: header * for modified documents rather than crunch()ing it. * (Length info in csp->content_length, which is 0 for * unmodified documents) * * - For this to work, sed() is called twice when filtering. * * Revision 1.7 2001/05/27 13:19:06 oes * Patched Joergs solution for the content-length in. * * Revision 1.6 2001/05/26 13:39:32 jongfoster * Only crunches Content-Length header if applying RE filtering. * Without this fix, Microsoft Windows Update wouldn't work. * * Revision 1.5 2001/05/26 00:28:36 jongfoster * Automatic reloading of config file. * Removed obsolete SIGHUP support (Unix) and Reload menu option (Win32). * Most of the global variables have been moved to a new * struct configuration_spec, accessed through csp->config->globalname * Most of the globals remaining are used by the Win32 GUI. * * Revision 1.4 2001/05/22 18:46:04 oes * * - Enabled filtering banners by size rather than URL * by adding patterns that replace all standard banner * sizes with the "Junkbuster" gif to the re_filterfile * * - Enabled filtering WebBugs by providing a pattern * which kills all 1x1 images * * - Added support for PCRE_UNGREEDY behaviour to pcrs, * which is selected by the (nonstandard and therefore * capital) letter 'U' in the option string. * It causes the quantifiers to be ungreedy by default. * Appending a ? turns back to greedy (!). * * - Added a new interceptor ijb-send-banner, which * sends back the "Junkbuster" gif. Without imagelist or * MSIE detection support, or if tinygif = 1, or the * URL isn't recognized as an imageurl, a lame HTML * explanation is sent instead. * * - Added new feature, which permits blocking remote * script redirects and firing back a local redirect * to the browser. * The feature is conditionally compiled, i.e. it * can be disabled with --disable-fast-redirects, * plus it must be activated by a "fast-redirects" * line in the config file, has its own log level * and of course wants to be displayed by show-proxy-args * Note: Boy, all the #ifdefs in 1001 locations and * all the fumbling with configure.in and acconfig.h * were *way* more work than the feature itself :-( * * - Because a generic redirect template was needed for * this, tinygif = 3 now uses the same. * * - Moved GIFs, and other static HTTP response templates * to project.h * * - Some minor fixes * * - Removed some >400 CRs again (Jon, you really worked * a lot! ;-) * * Revision 1.3 2001/05/20 01:21:20 jongfoster * Version 2.9.4 checkin. * - Merged popupfile and cookiefile, and added control over PCRS * filtering, in new "permissionsfile". * - Implemented LOG_LEVEL_FATAL, so that if there is a configuration * file error you now get a message box (in the Win32 GUI) rather * than the program exiting with no explanation. * - Made killpopup use the PCRS MIME-type checking and HTTP-header * skipping. * - Removed tabs from "config" * - Moved duplicated url parsing code in "loaders.c" to a new funcition. * - Bumped up version number. * * Revision 1.2 2001/05/17 23:02:36 oes * - Made referrer option accept 'L' as a substitute for '§' * * Revision 1.1.1.1 2001/05/15 13:59:01 oes * Initial import of version 2.9.3 source tree * * *********************************************************************/ #include "config.h" #ifndef _WIN32 #include #include #endif #include #include #include #include #ifdef __GLIBC__ /* * Convince GNU's libc to provide a strptime prototype. */ #define __USE_XOPEN #endif /*__GLIBC__ */ #include #ifdef FEATURE_ZLIB #include #endif #if !defined(_WIN32) && !defined(__OS2__) #include #endif #include "project.h" #ifdef FEATURE_PTHREAD #include "jcc.h" /* jcc.h is for mutex semapores only */ #endif /* def FEATURE_PTHREAD */ #include "list.h" #include "parsers.h" #include "encode.h" #include "ssplit.h" #include "errlog.h" #include "jbsockets.h" #include "miscutil.h" #include "list.h" #include "actions.h" #include "filters.h" #ifndef HAVE_STRPTIME #include "strptime.h" #endif const char parsers_h_rcs[] = PARSERS_H_VERSION; /* Fix a problem with Solaris. There should be no effect on other * platforms. * Solaris's isspace() is a macro which uses its argument directly * as an array index. Therefore we need to make sure that high-bit * characters generate +ve values, and ideally we also want to make * the argument match the declared parameter type of "int". * * Why did they write a character function that can't take a simple * "char" argument? Doh! */ #define ijb_isupper(__X) isupper((int)(unsigned char)(__X)) #define ijb_tolower(__X) tolower((int)(unsigned char)(__X)) static jb_err scan_headers(struct client_state *csp); static jb_err header_tagger(struct client_state *csp, char *header); static jb_err parse_header_time(const char *header_time, time_t *result); static jb_err crumble (struct client_state *csp, char **header); static jb_err connection (struct client_state *csp, char **header); static jb_err filter_header (struct client_state *csp, char **header); static jb_err client_referrer (struct client_state *csp, char **header); static jb_err client_uagent (struct client_state *csp, char **header); static jb_err client_ua (struct client_state *csp, char **header); static jb_err client_from (struct client_state *csp, char **header); static jb_err client_send_cookie (struct client_state *csp, char **header); static jb_err client_x_forwarded (struct client_state *csp, char **header); static jb_err client_accept_encoding (struct client_state *csp, char **header); static jb_err client_te (struct client_state *csp, char **header); static jb_err client_max_forwards (struct client_state *csp, char **header); static jb_err client_host (struct client_state *csp, char **header); static jb_err client_if_modified_since (struct client_state *csp, char **header); static jb_err client_accept_language (struct client_state *csp, char **header); static jb_err client_if_none_match (struct client_state *csp, char **header); static jb_err crunch_client_header (struct client_state *csp, char **header); static jb_err client_x_filter (struct client_state *csp, char **header); static jb_err client_range (struct client_state *csp, char **header); static jb_err server_set_cookie (struct client_state *csp, char **header); static jb_err server_content_type (struct client_state *csp, char **header); static jb_err server_content_length (struct client_state *csp, char **header); static jb_err server_content_md5 (struct client_state *csp, char **header); static jb_err server_content_encoding (struct client_state *csp, char **header); static jb_err server_transfer_coding (struct client_state *csp, char **header); static jb_err server_http (struct client_state *csp, char **header); static jb_err crunch_server_header (struct client_state *csp, char **header); static jb_err server_last_modified (struct client_state *csp, char **header); static jb_err server_content_disposition(struct client_state *csp, char **header); static jb_err client_host_adder (struct client_state *csp); static jb_err client_cookie_adder (struct client_state *csp); static jb_err client_xtra_adder (struct client_state *csp); static jb_err connection_close_adder (struct client_state *csp); static jb_err create_forged_referrer(char **header, const char *hostport); static jb_err create_fake_referrer(char **header, const char *fake_referrer); static jb_err handle_conditional_hide_referrer_parameter(char **header, const char *host, const int parameter_conditional_block); const struct parsers client_patterns[] = { { "referer:", 8, client_referrer }, { "user-agent:", 11, client_uagent }, { "ua-", 3, client_ua }, { "from:", 5, client_from }, { "cookie:", 7, client_send_cookie }, { "x-forwarded-for:", 16, client_x_forwarded }, { "Accept-Encoding:", 16, client_accept_encoding }, { "TE:", 3, client_te }, { "Host:", 5, client_host }, { "if-modified-since:", 18, client_if_modified_since }, { "Keep-Alive:", 11, crumble }, { "connection:", 11, connection }, { "proxy-connection:", 17, crumble }, { "max-forwards:", 13, client_max_forwards }, { "Accept-Language:", 16, client_accept_language }, { "if-none-match:", 14, client_if_none_match }, { "Range:", 6, client_range }, { "Request-Range:", 14, client_range }, { "If-Range:", 9, client_range }, { "X-Filter:", 9, client_x_filter }, { "*", 0, crunch_client_header }, { "*", 0, filter_header }, { NULL, 0, NULL } }; const struct parsers server_patterns[] = { { "HTTP/", 5, server_http }, { "set-cookie:", 11, server_set_cookie }, { "connection:", 11, connection }, { "Content-Type:", 13, server_content_type }, { "Content-MD5:", 12, server_content_md5 }, { "Content-Encoding:", 17, server_content_encoding }, { "Transfer-Encoding:", 18, server_transfer_coding }, { "Keep-Alive:", 11, crumble }, { "content-disposition:", 20, server_content_disposition }, { "Last-Modified:", 14, server_last_modified }, { "*", 0, crunch_server_header }, { "*", 0, filter_header }, { NULL, 0, NULL } }; const struct parsers server_patterns_light[] = { { "Content-Length:", 15, server_content_length }, { "Transfer-Encoding:", 18, server_transfer_coding }, #ifdef FEATURE_ZLIB { "Content-Encoding:", 17, server_content_encoding }, #endif /* def FEATURE_ZLIB */ { NULL, 0, NULL } }; const add_header_func_ptr add_client_headers[] = { client_host_adder, client_cookie_adder, client_xtra_adder, /* Temporarily disabled: client_accept_encoding_adder, */ connection_close_adder, NULL }; const add_header_func_ptr add_server_headers[] = { connection_close_adder, NULL }; /* The vanilla wafer. */ static const char VANILLA_WAFER[] = "NOTICE=TO_WHOM_IT_MAY_CONCERN_" "Do_not_send_me_any_copyrighted_information_other_than_the_" "document_that_I_am_requesting_or_any_of_its_necessary_components._" "In_particular_do_not_send_me_any_cookies_that_" "are_subject_to_a_claim_of_copyright_by_anybody._" "Take_notice_that_I_refuse_to_be_bound_by_any_license_condition_" "(copyright_or_otherwise)_applying_to_any_cookie._"; /********************************************************************* * * Function : flush_socket * * Description : Write any pending "buffered" content. * * Parameters : * 1 : fd = file descriptor of the socket to read * 2 : csp = Current client state (buffers, headers, etc...) * * Returns : On success, the number of bytes written are returned (zero * indicates nothing was written). On error, -1 is returned, * and errno is set appropriately. If count is zero and the * file descriptor refers to a regular file, 0 will be * returned without causing any other effect. For a special * file, the results are not portable. * *********************************************************************/ int flush_socket(jb_socket fd, struct client_state *csp) { struct iob *iob = csp->iob; int len = iob->eod - iob->cur; if (len <= 0) { return(0); } if (write_socket(fd, iob->cur, (size_t)len)) { return(-1); } iob->eod = iob->cur = iob->buf; return(len); } /********************************************************************* * * Function : add_to_iob * * Description : Add content to the buffered page, expanding the * buffer if necessary. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : buf = holds the content to be added to the page * 3 : n = number of bytes to be added * * Returns : JB_ERR_OK on success, JB_ERR_MEMORY if out-of-memory * or buffer limit reached. * *********************************************************************/ jb_err add_to_iob(struct client_state *csp, char *buf, int n) { struct iob *iob = csp->iob; size_t used, offset, need, want; char *p; if (n <= 0) return JB_ERR_OK; used = (size_t)(iob->eod - iob->buf); offset = (size_t)(iob->cur - iob->buf); need = used + (size_t)n + 1; /* * If the buffer can't hold the new data, extend it first. * Use the next power of two if possible, else use the actual need. */ if (need > csp->config->buffer_limit) { log_error(LOG_LEVEL_INFO, "Buffer limit reached while extending the buffer (iob)"); return JB_ERR_MEMORY; } if (need > iob->size) { for (want = csp->iob->size ? csp->iob->size : 512; want <= need;) want *= 2; if (want <= csp->config->buffer_limit && NULL != (p = (char *)realloc(iob->buf, want))) { iob->size = want; } else if (NULL != (p = (char *)realloc(iob->buf, need))) { iob->size = need; } else { log_error(LOG_LEVEL_ERROR, "Extending the buffer (iob) failed: %E"); return JB_ERR_MEMORY; } /* Update the iob pointers */ iob->cur = p + offset; iob->eod = p + used; iob->buf = p; } /* copy the new data into the iob buffer */ memcpy(iob->eod, buf, (size_t)n); /* point to the end of the data */ iob->eod += n; /* null terminate == cheap insurance */ *iob->eod = '\0'; return JB_ERR_OK; } #ifdef FEATURE_ZLIB /********************************************************************* * * Function : decompress_iob * * Description : Decompress buffered page, expanding the * buffer as necessary. csp->iob->cur * should point to the the beginning of the * compressed data block. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK on success, * JB_ERR_MEMORY if out-of-memory limit reached, and * JB_ERR_COMPRESS if error decompressing buffer. * *********************************************************************/ jb_err decompress_iob(struct client_state *csp) { char *buf; /* new, uncompressed buffer */ char *cur; /* Current iob position (to keep the original * iob->cur unmodified if we return early) */ size_t bufsize; /* allocated size of the new buffer */ size_t old_size; /* Content size before decompression */ size_t skip_size; /* Number of bytes at the beginning of the iob that we should NOT decompress. */ int status; /* return status of the inflate() call */ z_stream zstr; /* used by calls to zlib */ assert(csp->iob->cur - csp->iob->buf > 0); assert(csp->iob->eod - csp->iob->cur > 0); bufsize = csp->iob->size; skip_size = (size_t)(csp->iob->cur - csp->iob->buf); old_size = (size_t)(csp->iob->eod - csp->iob->cur); cur = csp->iob->cur; if (bufsize < 10) { /* * This is to protect the parsing of gzipped data, * but it should(?) be valid for deflated data also. */ log_error(LOG_LEVEL_ERROR, "Buffer too small decompressing iob"); return JB_ERR_COMPRESS; } if (csp->content_type & CT_GZIP) { /* * Our task is slightly complicated by the facts that data * compressed by gzip does not include a zlib header, and * that there is no easily accessible interface in zlib to * handle a gzip header. We strip off the gzip header by * hand, and later inform zlib not to expect a header. */ /* * Strip off the gzip header. Please see RFC 1952 for more * explanation of the appropriate fields. */ if ((*cur++ != (char)0x1f) || (*cur++ != (char)0x8b) || (*cur++ != Z_DEFLATED)) { log_error(LOG_LEVEL_ERROR, "Invalid gzip header when decompressing"); return JB_ERR_COMPRESS; } else { int flags = *cur++; /* * XXX: These magic numbers should be replaced * with macros to give a better idea what they do. */ if (flags & 0xe0) { /* The gzip header has reserved bits set; bail out. */ log_error(LOG_LEVEL_ERROR, "Invalid gzip header flags when decompressing"); return JB_ERR_COMPRESS; } cur += 6; /* Skip extra fields if necessary. */ if (flags & 0x04) { /* * Skip a given number of bytes, specified * as a 16-bit little-endian value. */ /* * XXX: This code used to be: * * csp->iob->cur += *csp->iob->cur++ + (*csp->iob->cur++ << 8); * * which I had to change into: * * cur += *cur++ + (*cur++ << 8); * * at which point gcc43 finally noticed that the value * of cur is undefined (it depends on which of the * summands is evaluated first). * * I haven't come across a site where this * code is actually executed yet, but I hope * it works anyway. */ int skip_bytes; skip_bytes = *cur++; skip_bytes = *cur++ << 8; assert(skip_bytes == *csp->iob->cur - 2 + ((*csp->iob->cur - 1) << 8)); /* * The number of bytes to skip should be positive * and we'd like to stay in the buffer. */ if ((skip_bytes < 0) || (skip_bytes >= (csp->iob->eod - cur))) { log_error(LOG_LEVEL_ERROR, "Unreasonable amount of bytes to skip (%d). Stopping decompression", skip_bytes); return JB_ERR_COMPRESS; } log_error(LOG_LEVEL_INFO, "Skipping %d bytes for gzip compression. Does this sound right?", skip_bytes); cur += skip_bytes; } /* Skip the filename if necessary. */ if (flags & 0x08) { /* A null-terminated string is supposed to follow. */ while (*cur++ && (cur < csp->iob->eod)); } /* Skip the comment if necessary. */ if (flags & 0x10) { /* A null-terminated string is supposed to follow. */ while (*cur++ && (cur < csp->iob->eod)); } /* Skip the CRC if necessary. */ if (flags & 0x02) { cur += 2; } if (cur >= csp->iob->eod) { /* * If the current position pointer reached or passed * the buffer end, we were obviously tricked to skip * too much. */ log_error(LOG_LEVEL_ERROR, "Malformed gzip header detected. Aborting decompression."); return JB_ERR_COMPRESS; } } } else if (csp->content_type & CT_DEFLATE) { /* * XXX: The debug level should be lowered * before the next stable release. */ log_error(LOG_LEVEL_INFO, "Decompressing deflated iob: %d", *cur); /* * In theory (that is, according to RFC 1950), deflate-compressed * data should begin with a two-byte zlib header and have an * adler32 checksum at the end. It seems that in practice only * the raw compressed data is sent. Note that this means that * we are not RFC 1950-compliant here, but the advantage is that * this actually works. :) * * We add a dummy null byte to tell zlib where the data ends, * and later inform it not to expect a header. * * Fortunately, add_to_iob() has thoughtfully null-terminated * the buffer; we can just increment the end pointer to include * the dummy byte. */ csp->iob->eod++; } else { log_error(LOG_LEVEL_ERROR, "Unable to determine compression format for decompression"); return JB_ERR_COMPRESS; } /* Set up the fields required by zlib. */ zstr.next_in = (Bytef *)cur; zstr.avail_in = (unsigned int)(csp->iob->eod - cur); zstr.zalloc = Z_NULL; zstr.zfree = Z_NULL; zstr.opaque = Z_NULL; /* * Passing -MAX_WBITS to inflateInit2 tells the library * that there is no zlib header. */ if (inflateInit2 (&zstr, -MAX_WBITS) != Z_OK) { log_error(LOG_LEVEL_ERROR, "Error initializing decompression"); return JB_ERR_COMPRESS; } /* * Next, we allocate new storage for the inflated data. * We don't modify the existing iob yet, so in case there * is error in decompression we can recover gracefully. */ buf = zalloc(bufsize); if (NULL == buf) { log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob"); return JB_ERR_MEMORY; } assert(bufsize >= skip_size); memcpy(buf, csp->iob->buf, skip_size); zstr.avail_out = bufsize - skip_size; zstr.next_out = (Bytef *)buf + skip_size; /* Try to decompress the whole stream in one shot. */ while (Z_BUF_ERROR == (status = inflate(&zstr, Z_FINISH))) { /* We need to allocate more memory for the output buffer. */ char *tmpbuf; /* used for realloc'ing the buffer */ size_t oldbufsize = bufsize; /* keep track of the old bufsize */ /* * If zlib wants more data then there's a problem, because * the complete compressed file should have been buffered. */ if (0 == zstr.avail_in) { log_error(LOG_LEVEL_ERROR, "Unexpected end of compressed iob"); return JB_ERR_COMPRESS; } /* * If we tried the limit and still didn't have enough * memory, just give up. */ if (bufsize == csp->config->buffer_limit) { log_error(LOG_LEVEL_ERROR, "Buffer limit reached while decompressing iob"); return JB_ERR_MEMORY; } /* Try doubling the buffer size each time. */ bufsize *= 2; /* Don't exceed the buffer limit. */ if (bufsize > csp->config->buffer_limit) { bufsize = csp->config->buffer_limit; } /* Try to allocate the new buffer. */ tmpbuf = realloc(buf, bufsize); if (NULL == tmpbuf) { log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob"); freez(buf); return JB_ERR_MEMORY; } else { char *oldnext_out = (char *)zstr.next_out; /* * Update the fields for inflate() to use the new * buffer, which may be in a location different from * the old one. */ zstr.avail_out += bufsize - oldbufsize; zstr.next_out = (Bytef *)tmpbuf + bufsize - zstr.avail_out; /* * Compare with an uglier method of calculating these values * that doesn't require the extra oldbufsize variable. */ assert(zstr.avail_out == tmpbuf + bufsize - (char *)zstr.next_out); assert((char *)zstr.next_out == tmpbuf + ((char *)oldnext_out - buf)); assert(zstr.avail_out > 0); buf = tmpbuf; } } if (Z_STREAM_ERROR == inflateEnd(&zstr)) { log_error(LOG_LEVEL_ERROR, "Inconsistent stream state after decompression: %s", zstr.msg); /* * XXX: Intentionally no return. * * According to zlib.h, Z_STREAM_ERROR is returned * "if the stream state was inconsistent". * * I assume in this case inflate()'s status * would also be something different than Z_STREAM_END * so this check should be redundant, but lets see. */ } if (status != Z_STREAM_END) { /* We failed to decompress the stream. */ log_error(LOG_LEVEL_ERROR, "Error in decompressing to the buffer (iob): %s", zstr.msg); return JB_ERR_COMPRESS; } /* * Finally, we can actually update the iob, since the * decompression was successful. First, free the old * buffer. */ freez(csp->iob->buf); /* Now, update the iob to use the new buffer. */ csp->iob->buf = buf; csp->iob->cur = csp->iob->buf + skip_size; csp->iob->eod = (char *)zstr.next_out; csp->iob->size = bufsize; /* * Make sure the new uncompressed iob obeys some minimal * consistency conditions. */ if ((csp->iob->buf < csp->iob->cur) && (csp->iob->cur <= csp->iob->eod) && (csp->iob->eod <= csp->iob->buf + csp->iob->size)) { const size_t new_size = (size_t)(csp->iob->eod - csp->iob->cur); if (new_size > 0) { log_error(LOG_LEVEL_RE_FILTER, "Decompression successful. Old size: %d, new size: %d.", old_size, new_size); } else { /* zlib thinks this is OK, so lets do the same. */ log_error(LOG_LEVEL_INFO, "Decompression didn't result in any content."); } } else { /* It seems that zlib did something weird. */ log_error(LOG_LEVEL_ERROR, "Unexpected error decompressing the buffer (iob): %d==%d, %d>%d, %d<%d", csp->iob->cur, csp->iob->buf + skip_size, csp->iob->eod, csp->iob->buf, csp->iob->eod, csp->iob->buf + csp->iob->size); return JB_ERR_COMPRESS; } return JB_ERR_OK; } #endif /* defined(FEATURE_ZLIB) */ /********************************************************************* * * Function : get_header * * Description : This (odd) routine will parse the csp->iob * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : Any one of the following: * * 1) a pointer to a dynamically allocated string that contains a header line * 2) NULL indicating that the end of the header was reached * 3) "" indicating that the end of the iob was reached before finding * a complete header line. * *********************************************************************/ char *get_header(struct client_state *csp) { struct iob *iob; char *p, *q, *ret; iob = csp->iob; if ((iob->cur == NULL) || ((p = strchr(iob->cur, '\n')) == NULL)) { return(""); /* couldn't find a complete header */ } *p = '\0'; ret = strdup(iob->cur); if (ret == NULL) { /* FIXME No way to handle error properly */ log_error(LOG_LEVEL_FATAL, "Out of memory in get_header()"); } iob->cur = p+1; if ((q = strchr(ret, '\r')) != NULL) *q = '\0'; /* is this a blank line (i.e. the end of the header) ? */ if (*ret == '\0') { freez(ret); return(NULL); } return(ret); } /********************************************************************* * * Function : get_header_value * * Description : Get the value of a given header from a chained list * of header lines or return NULL if no such header is * present in the list. * * Parameters : * 1 : header_list = pointer to list * 2 : header_name = string with name of header to look for. * Trailing colon required, capitalization * doesn't matter. * * Returns : NULL if not found, else value of header * *********************************************************************/ char *get_header_value(const struct list *header_list, const char *header_name) { struct list_entry *cur_entry; char *ret = NULL; size_t length = 0; assert(header_list); assert(header_name); length = strlen(header_name); for (cur_entry = header_list->first; cur_entry ; cur_entry = cur_entry->next) { if (cur_entry->str) { if (!strncmpic(cur_entry->str, header_name, length)) { /* * Found: return pointer to start of value */ ret = (char *) (cur_entry->str + length); while (*ret && ijb_isspace(*ret)) ret++; return(ret); } } } /* * Not found */ return NULL; } /********************************************************************* * * Function : scan_headers * * Description : Scans headers, applies tags and updates action bits. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK * *********************************************************************/ static jb_err scan_headers(struct client_state *csp) { struct list_entry *h; /* Header */ jb_err err = JB_ERR_OK; for (h = csp->headers->first; (err == JB_ERR_OK) && (h != NULL) ; h = h->next) { /* Header crunch()ed in previous run? -> ignore */ if (h->str == NULL) continue; log_error(LOG_LEVEL_HEADER, "scan: %s", h->str); err = header_tagger(csp, h->str); } return err; } /********************************************************************* * * Function : sed * * Description : add, delete or modify lines in the HTTP header streams. * On entry, it receives a linked list of headers space * that was allocated dynamically (both the list nodes * and the header contents). * * As a side effect it frees the space used by the original * header lines. * * XXX: should be split to remove the first_run hack. * * Parameters : * 1 : pats = list of patterns to match against headers * 2 : more_headers = list of functions to add more * headers (client or server) * 3 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK in case off success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ jb_err sed(const struct parsers pats[], const add_header_func_ptr more_headers[], struct client_state *csp) { struct list_entry *p; const struct parsers *v; const add_header_func_ptr *f; jb_err err = JB_ERR_OK; int first_run; /* * If filtering is enabled, sed is run twice, * but most of the work needs to be done only once. */ first_run = (more_headers != NULL ) ? 1 : 0; if (first_run) /* Parse and print */ { scan_headers(csp); for (v = pats; (err == JB_ERR_OK) && (v->str != NULL) ; v++) { for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL) ; p = p->next) { /* Header crunch()ed in previous run? -> ignore */ if (p->str == NULL) continue; /* Does the current parser handle this header? */ if ((strncmpic(p->str, v->str, v->len) == 0) || (v->len == CHECK_EVERY_HEADER_REMAINING)) { err = v->parser(csp, (char **)&(p->str)); } } } /* place any additional headers on the csp->headers list */ for (f = more_headers; (err == JB_ERR_OK) && (*f) ; f++) { err = (*f)(csp); } } else /* Parse only */ { /* * The second run is only needed if the body was modified * and the content-lenght has changed. */ if (strncmpic(csp->http->cmd, "HEAD", 4)) { /*XXX: Code duplication */ for (v = pats; (err == JB_ERR_OK) && (v->str != NULL) ; v++) { for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL) ; p = p->next) { /* Header crunch()ed in previous run? -> ignore */ if (p->str == NULL) continue; /* Does the current parser handle this header? */ if (strncmpic(p->str, v->str, v->len) == 0) { err = v->parser(csp, (char **)&(p->str)); } } } } } return err; } /********************************************************************* * * Function : header_tagger * * Description : Executes all text substitutions from applying * tag actions and saves the result as tag. * * XXX: Shares enough code with filter_header() and * pcrs_filter_response() to warrant some helper functions. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = Header that is used as tagger input * * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ static jb_err header_tagger(struct client_state *csp, char *header) { int wanted_filter_type; int multi_action_index; int i; pcrs_job *job; struct file_list *fl; struct re_filterfile_spec *b; struct list_entry *tag_name; int found_filters = 0; const size_t header_length = strlen(header); if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) { wanted_filter_type = FT_SERVER_HEADER_TAGGER; multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER; } else { wanted_filter_type = FT_CLIENT_HEADER_TAGGER; multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER; } /* Check if there are any filters */ for (i = 0; i < MAX_AF_FILES; i++) { fl = csp->rlist[i]; if (NULL != fl) { if (NULL != fl->f) { found_filters = 1; break; } } } if (0 == found_filters) { log_error(LOG_LEVEL_ERROR, "Inconsistent configuration: " "tagging enabled, but no taggers available."); return(JB_ERR_OK); } for (i = 0; i < MAX_AF_FILES; i++) { fl = csp->rlist[i]; if ((NULL == fl) || (NULL == fl->f)) { /* * Either there are no filter files * left, or this filter file just * contains no valid filters. * * Continue to be sure we don't miss * valid filter files that are chained * after empty or invalid ones. */ continue; } /* For all filters, */ for (b = fl->f; b; b = b->next) { if (b->type != wanted_filter_type) { /* skip the ones we don't care about, */ continue; } /* leaving only taggers that could apply, of which we use the ones, */ for (tag_name = csp->action->multi[multi_action_index]->first; NULL != tag_name; tag_name = tag_name->next) { /* that do apply, and */ if (strcmp(b->name, tag_name->str) == 0) { char *modified_tag = NULL; char *tag = header; size_t size = header_length; pcrs_job *joblist = b->joblist; if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b); if (NULL == joblist) { log_error(LOG_LEVEL_RE_FILTER, "Tagger %s has empty joblist. Nothing to do.", b->name); continue; } /* execute their pcrs_joblist on the header. */ for (job = joblist; NULL != job; job = job->next) { const int hits = pcrs_execute(job, tag, size, &modified_tag, &size); if (0 < hits) { /* Success, continue with the modified version. */ if (tag != header) { freez(tag); } tag = modified_tag; } else { /* Tagger doesn't match */ if (0 > hits) { /* Regex failure, log it but continue anyway. */ log_error(LOG_LEVEL_ERROR, "Problems with tagger \'%s\' and header \'%s\': %s", b->name, *header, pcrs_strerror(hits)); } freez(modified_tag); } } if (b->dynamic) pcrs_free_joblist(joblist); /* If this tagger matched */ if (tag != header) { if (0 == size) { /* * There is to technical limitation which makes * it impossible to use empty tags, but I assume * no one would do it intentionally. */ freez(tag); log_error(LOG_LEVEL_INFO, "Tagger \'%s\' created an empty tag. Ignored.", b->name); continue; } if (!list_contains_item(csp->tags, tag)) { if (JB_ERR_OK != enlist(csp->tags, tag)) { log_error(LOG_LEVEL_ERROR, "Insufficient memory to add tag \'%s\', " "based on tagger \'%s\' and header \'%s\'", tag, b->name, *header); } else { char *action_message; /* * update the action bits right away, to make * tagging based on tags set by earlier taggers * of the same kind possible. */ if (update_action_bits_for_tag(csp, tag)) { action_message = "Action bits updated accordingly."; } else { action_message = "No action bits update necessary."; } log_error(LOG_LEVEL_HEADER, "Tagger \'%s\' added tag \'%s\'. %s", b->name, tag, action_message); } } else { /* XXX: Is this log-worthy? */ log_error(LOG_LEVEL_HEADER, "Tagger \'%s\' didn't add tag \'%s\'. " "Tag already present", b->name, tag); } freez(tag); } /* if the tagger matched */ } /* if the tagger applies */ } /* for every tagger that could apply */ } /* for all filters */ } /* for all filter files */ return JB_ERR_OK; } /* here begins the family of parser functions that reformat header lines */ /********************************************************************* * * Function : filter_header * * Description : Executes all text substitutions from all applying * +(server|client)-header-filter actions on the header. * Most of the code was copied from pcrs_filter_response, * including the rather short variable names * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ static jb_err filter_header(struct client_state *csp, char **header) { int hits=0; int matches; size_t size = strlen(*header); char *newheader = NULL; pcrs_job *job; struct file_list *fl; struct re_filterfile_spec *b; struct list_entry *filtername; int i, found_filters = 0; int wanted_filter_type; int multi_action_index; if (csp->flags & CSP_FLAG_NO_FILTERING) { return JB_ERR_OK; } if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) { wanted_filter_type = FT_SERVER_HEADER_FILTER; multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER; } else { wanted_filter_type = FT_CLIENT_HEADER_FILTER; multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER; } /* * Need to check the set of re_filterfiles... */ for (i = 0; i < MAX_AF_FILES; i++) { fl = csp->rlist[i]; if (NULL != fl) { if (NULL != fl->f) { found_filters = 1; break; } } } if (0 == found_filters) { log_error(LOG_LEVEL_ERROR, "Inconsistent configuration: " "header filtering enabled, but no matching filters available."); return(JB_ERR_OK); } for (i = 0; i < MAX_AF_FILES; i++) { fl = csp->rlist[i]; if ((NULL == fl) || (NULL == fl->f)) { /* * Either there are no filter files * left, or this filter file just * contains no valid filters. * * Continue to be sure we don't miss * valid filter files that are chained * after empty or invalid ones. */ continue; } /* * For all applying +filter actions, look if a filter by that * name exists and if yes, execute its pcrs_joblist on the * buffer. */ for (b = fl->f; b; b = b->next) { if (b->type != wanted_filter_type) { /* Skip other filter types */ continue; } for (filtername = csp->action->multi[multi_action_index]->first; filtername ; filtername = filtername->next) { if (strcmp(b->name, filtername->str) == 0) { int current_hits = 0; pcrs_job *joblist = b->joblist; if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b); if (NULL == joblist) { log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name); continue; } log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %d) with \'%s\' ...", *header, size, b->name); /* Apply all jobs from the joblist */ for (job = joblist; NULL != job; job = job->next) { matches = pcrs_execute(job, *header, size, &newheader, &size); if ( 0 < matches ) { current_hits += matches; log_error(LOG_LEVEL_HEADER, "Transforming \"%s\" to \"%s\"", *header, newheader); freez(*header); *header = newheader; } else if ( 0 == matches ) { /* Filter doesn't change header */ freez(newheader); } else { /* RegEx failure */ log_error(LOG_LEVEL_ERROR, "Filtering \'%s\' with \'%s\' didn't work out: %s", *header, b->name, pcrs_strerror(matches)); if (newheader != NULL) { log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader); freez(newheader); } } } if (b->dynamic) pcrs_free_joblist(joblist); log_error(LOG_LEVEL_RE_FILTER, "... produced %d hits (new size %d).", current_hits, size); hits += current_hits; } } } } /* * Additionally checking for hits is important because if * the continue hack is triggered, server headers can * arrive empty to separate multiple heads from each other. */ if ((0 == size) && hits) { log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header); freez(*header); } return(JB_ERR_OK); } /********************************************************************* * * Function : connection * * Description : Makes sure that the value of the Connection: header * is "close" and signals connection_close_adder * to do nothing. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err connection(struct client_state *csp, char **header) { char *old_header = *header; /* Do we have a 'Connection: close' header? */ if (strcmpic(*header, "Connection: close")) { /* No, create one */ *header = strdup("Connection: close"); if (header == NULL) { return JB_ERR_MEMORY; } log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header); freez(old_header); } /* Signal connection_close_adder() to return early. */ if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) { csp->flags |= CSP_FLAG_SERVER_CONNECTION_CLOSE_SET; } else { csp->flags |= CSP_FLAG_CLIENT_CONNECTION_CLOSE_SET; } return JB_ERR_OK; } /********************************************************************* * * Function : crumble * * Description : This is called if a header matches a pattern to "crunch" * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err crumble(struct client_state *csp, char **header) { log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header); freez(*header); return JB_ERR_OK; } /********************************************************************* * * Function : crunch_server_header * * Description : Crunch server header if it matches a string supplied by the * user. Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ static jb_err crunch_server_header(struct client_state *csp, char **header) { const char *crunch_pattern; /* Do we feel like crunching? */ if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER)) { crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER]; /* Is the current header the lucky one? */ if (strstr(*header, crunch_pattern)) { log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern); freez(*header); } } return JB_ERR_OK; } /********************************************************************* * * Function : server_content_type * * Description : Set the content-type for filterable types (text/.*, * .*xml.*, javascript and image/gif) unless filtering has been * forbidden (CT_TABOO) while parsing earlier headers. * NOTE: Since text/plain is commonly used by web servers * for files whose correct type is unknown, we don't * set CT_TEXT for it. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_content_type(struct client_state *csp, char **header) { /* Remove header if it isn't the first Content-Type header */ if ((csp->content_type & CT_DECLARED)) { /* * Another, slightly slower, way to see if * we already parsed another Content-Type header. */ assert(NULL != get_header_value(csp->headers, "Content-Type:")); log_error(LOG_LEVEL_ERROR, "Multiple Content-Type headers. Removing and ignoring: \'%s\'", *header); freez(*header); return JB_ERR_OK; } /* * Signal that the Content-Type has been set. */ csp->content_type |= CT_DECLARED; if (!(csp->content_type & CT_TABOO)) { /* * XXX: The assumption that text/plain is a sign of * binary data seems to be somewhat unreasonable nowadays * and should be dropped after 3.0.8 is out. */ if ((strstr(*header, "text/") && !strstr(*header, "plain")) || strstr(*header, "xml") || strstr(*header, "application/x-javascript")) { csp->content_type |= CT_TEXT; } else if (strstr(*header, "image/gif")) { csp->content_type |= CT_GIF; } else if (strstr(*header, "image/jpeg")) { csp->content_type |= CT_JPEG; } } /* * Are we messing with the content type? */ if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE) { /* * Make sure the user doesn't accidently * change the content type of binary documents. */ if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE)) { freez(*header); *header = strdup("Content-Type: "); string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]); if (header == NULL) { log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!"); return JB_ERR_MEMORY; } log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header); } else { log_error(LOG_LEVEL_HEADER, "%s not replaced. " "It doesn't look like a content type that should be filtered. " "Enable force-text-mode if you know what you're doing.", *header); } } return JB_ERR_OK; } /********************************************************************* * * Function : server_transfer_coding * * Description : - Prohibit filtering (CT_TABOO) if transfer coding compresses * - Raise the CSP_FLAG_CHUNKED flag if coding is "chunked" * - Remove header if body was chunked but has been * de-chunked for filtering. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_transfer_coding(struct client_state *csp, char **header) { /* * Turn off pcrs and gif filtering if body compressed */ if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate")) { #ifdef FEATURE_ZLIB /* * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here. */ log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.", csp->http->cmd, *header); #endif /* def FEATURE_ZLIB */ csp->content_type = CT_TABOO; } /* * Raise flag if body chunked */ if (strstr(*header, "chunked")) { csp->flags |= CSP_FLAG_CHUNKED; /* * If the body was modified, it has been de-chunked first * and the header must be removed. * * FIXME: If there is more than one transfer encoding, * only the "chunked" part should be removed here. */ if (csp->flags & CSP_FLAG_MODIFIED) { log_error(LOG_LEVEL_HEADER, "Removing: %s", *header); freez(*header); } } return JB_ERR_OK; } /********************************************************************* * * Function : server_content_encoding * * Description : This function is run twice for each request, * unless FEATURE_ZLIB and filtering are disabled. * * The first run is used to check if the content * is compressed, if FEATURE_ZLIB is disabled * filtering is then disabled as well, if FEATURE_ZLIB * is enabled the content is marked for decompression. * * The second run is used to remove the Content-Encoding * header if the decompression was successful. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_content_encoding(struct client_state *csp, char **header) { #ifdef FEATURE_ZLIB if ((csp->flags & CSP_FLAG_MODIFIED) && (csp->content_type & (CT_GZIP | CT_DEFLATE))) { /* * We successfully decompressed the content, * and have to clean the header now, so the * client no longer expects compressed data.. * * XXX: There is a difference between cleaning * and removing it completely. */ log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header); freez(*header); } else if (strstr(*header, "gzip")) { /* Mark for gzip decompression */ csp->content_type |= CT_GZIP; } else if (strstr(*header, "deflate")) { /* Mark for zlib decompression */ csp->content_type |= CT_DEFLATE; } else if (strstr(*header, "compress")) { /* * We can't decompress this; therefore we can't filter * it either. */ csp->content_type |= CT_TABOO; } #else /* !defined(FEATURE_ZLIB) */ if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate")) { /* * Body is compressed, turn off pcrs and gif filtering. */ csp->content_type |= CT_TABOO; /* * Log a warning if the user expects the content to be filtered. */ if ((csp->rlist != NULL) && (!list_is_empty(csp->action->multi[ACTION_MULTI_FILTER]))) { log_error(LOG_LEVEL_INFO, "Compressed content detected, content filtering disabled. " "Consider recompiling Privoxy with zlib support or " "enable the prevent-compression action."); } } #endif /* defined(FEATURE_ZLIB) */ return JB_ERR_OK; } /********************************************************************* * * Function : server_content_length * * Description : Adjust Content-Length header if we modified * the body. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_content_length(struct client_state *csp, char **header) { const size_t max_header_length = 80; /* Regenerate header if the content was modified. */ if (csp->flags & CSP_FLAG_MODIFIED) { freez(*header); *header = (char *) zalloc(max_header_length); if (*header == NULL) { return JB_ERR_MEMORY; } snprintf(*header, max_header_length, "Content-Length: %d", (int)csp->content_length); log_error(LOG_LEVEL_HEADER, "Adjusted Content-Length to %d", (int)csp->content_length); } return JB_ERR_OK; } /********************************************************************* * * Function : server_content_md5 * * Description : Crumble any Content-MD5 headers if the document was * modified. FIXME: Should we re-compute instead? * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_content_md5(struct client_state *csp, char **header) { if (csp->flags & CSP_FLAG_MODIFIED) { log_error(LOG_LEVEL_HEADER, "Crunching Content-MD5"); freez(*header); } return JB_ERR_OK; } /********************************************************************* * * Function : server_content_disposition * * Description : If enabled, blocks or modifies the "Content-Disposition" header. * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_content_disposition(struct client_state *csp, char **header) { const char *newval; /* * Are we messing with the Content-Disposition header? */ if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0) { /* Me tinks not */ return JB_ERR_OK; } newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION]; if ((newval == NULL) || (0 == strcmpic(newval, "block"))) { /* * Blocking content-disposition header */ log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header); freez(*header); return JB_ERR_OK; } else { /* * Replacing Content-Disposition header */ freez(*header); *header = strdup("Content-Disposition: "); string_append(header, newval); if (*header != NULL) { log_error(LOG_LEVEL_HEADER, "Content-Disposition header crunched and replaced with: %s", *header); } } return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } /********************************************************************* * * Function : server_last_modified * * Description : Changes Last-Modified header to the actual date * to help hide-if-modified-since. * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_last_modified(struct client_state *csp, char **header) { const char *newval; char buf[BUFFER_SIZE]; char newheader[50]; #ifdef HAVE_GMTIME_R struct tm gmt; #endif struct tm *timeptr = NULL; time_t now, last_modified; long int rtime; long int days, hours, minutes, seconds; /* * Are we messing with the Last-Modified header? */ if ((csp->action->flags & ACTION_OVERWRITE_LAST_MODIFIED) == 0) { /*Nope*/ return JB_ERR_OK; } newval = csp->action->string[ACTION_STRING_LAST_MODIFIED]; if (0 == strcmpic(newval, "block") ) { /* * Blocking Last-Modified header. Useless but why not. */ log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header); freez(*header); return JB_ERR_OK; } else if (0 == strcmpic(newval, "reset-to-request-time")) { /* * Setting Last-Modified Header to now. */ get_http_time(0, buf); freez(*header); *header = strdup("Last-Modified: "); string_append(header, buf); if (*header == NULL) { log_error(LOG_LEVEL_HEADER, "Insufficent memory. Last-Modified header got lost, boohoo."); } else { log_error(LOG_LEVEL_HEADER, "Reset to present time: %s", *header); } } else if (0 == strcmpic(newval, "randomize")) { const char *header_time = *header + sizeof("Last-Modified:"); log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header); now = time(NULL); #ifdef HAVE_GMTIME_R timeptr = gmtime_r(&now, &gmt); #elif FEATURE_PTHREAD pthread_mutex_lock(&gmtime_mutex); timeptr = gmtime(&now); pthread_mutex_unlock(&gmtime_mutex); #else timeptr = gmtime(&now); #endif if (JB_ERR_OK != parse_header_time(header_time, &last_modified)) { log_error(LOG_LEVEL_HEADER, "Couldn't parse: %s in %s (crunching!)", header_time, *header); freez(*header); } else { rtime = (long int)difftime(now, last_modified); if (rtime) { int negative = 0; if (rtime < 0) { rtime *= -1; negative = 1; log_error(LOG_LEVEL_HEADER, "Server time in the future."); } rtime = pick_from_range(rtime); if (negative) rtime *= -1; last_modified += rtime; #ifdef HAVE_GMTIME_R timeptr = gmtime_r(&last_modified, &gmt); #elif FEATURE_PTHREAD pthread_mutex_lock(&gmtime_mutex); timeptr = gmtime(&last_modified); pthread_mutex_unlock(&gmtime_mutex); #else timeptr = gmtime(&last_modified); #endif strftime(newheader, sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr); freez(*header); *header = strdup("Last-Modified: "); string_append(header, newheader); if (*header == NULL) { log_error(LOG_LEVEL_ERROR, "Insufficent memory, header crunched without replacement."); return JB_ERR_MEMORY; } if (LOG_LEVEL_HEADER & debug) /* Save cycles if the user isn't interested. */ { days = rtime / (3600 * 24); hours = rtime / 3600 % 24; minutes = rtime / 60 % 60; seconds = rtime % 60; log_error(LOG_LEVEL_HEADER, "Randomized: %s (added %d da%s %d hou%s %d minut%s %d second%s", *header, days, (days == 1) ? "y" : "ys", hours, (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)"); } } else { log_error(LOG_LEVEL_HEADER, "Randomized ... or not. No time difference to work with."); } } } return JB_ERR_OK; } /********************************************************************* * * Function : client_accept_encoding * * Description : Rewrite the client's Accept-Encoding header so that * if doesn't allow compression, if the action applies. * Note: For HTTP/1.0 the absence of the header is enough. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_accept_encoding(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0) { log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress content"); freez(*header); /* Temporarily disable the correct behaviour to * work around a PHP bug. * * if (!strcmpic(csp->http->ver, "HTTP/1.1")) * { * *header = strdup("Accept-Encoding: identity;q=1.0, *;q=0"); * if (*header == NULL) * { * return JB_ERR_MEMORY; * } * } * */ } return JB_ERR_OK; } /********************************************************************* * * Function : client_te * * Description : Rewrite the client's TE header so that * if doesn't allow compression, if the action applies. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_te(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0) { freez(*header); log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress transfer"); } return JB_ERR_OK; } /********************************************************************* * * Function : client_referrer * * Description : Handle the "referer" config setting properly. * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_referrer(struct client_state *csp, char **header) { const char *parameter; /* booleans for parameters we have to check multiple times */ int parameter_conditional_block; int parameter_conditional_forge; #ifdef FEATURE_FORCE_LOAD /* * Since the referrer can include the prefix even * if the request itself is non-forced, we must * clean it unconditionally. * * XXX: strclean is too broad */ strclean(*header, FORCE_PREFIX); #endif /* def FEATURE_FORCE_LOAD */ if ((csp->action->flags & ACTION_HIDE_REFERER) == 0) { /* Nothing left to do */ return JB_ERR_OK; } parameter = csp->action->string[ACTION_STRING_REFERER]; assert(parameter != NULL); parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block")); parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge")); if (!parameter_conditional_block && !parameter_conditional_forge) { /* * As conditional-block and conditional-forge are the only * parameters that rely on the original referrer, we can * remove it now for all the others. */ freez(*header); } if (0 == strcmpic(parameter, "block")) { log_error(LOG_LEVEL_HEADER, "Referer crunched!"); return JB_ERR_OK; } else if (parameter_conditional_block || parameter_conditional_forge) { return handle_conditional_hide_referrer_parameter(header, csp->http->hostport, parameter_conditional_block); } else if (0 == strcmpic(parameter, "forge")) { return create_forged_referrer(header, csp->http->hostport); } else { /* interpret parameter as user-supplied referer to fake */ return create_fake_referrer(header, parameter); } } /********************************************************************* * * Function : client_accept_language * * Description : Handle the "Accept-Language" config setting properly. * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_accept_language(struct client_state *csp, char **header) { const char *newval; /* * Are we messing with the Accept-Language? */ if ((csp->action->flags & ACTION_HIDE_ACCEPT_LANGUAGE) == 0) { /*I don't think so*/ return JB_ERR_OK; } newval = csp->action->string[ACTION_STRING_LANGUAGE]; if ((newval == NULL) || (0 == strcmpic(newval, "block")) ) { /* * Blocking Accept-Language header */ log_error(LOG_LEVEL_HEADER, "Crunching Accept-Language!"); freez(*header); return JB_ERR_OK; } else { /* * Replacing Accept-Language header */ freez(*header); *header = strdup("Accept-Language: "); string_append(header, newval); if (*header == NULL) { log_error(LOG_LEVEL_ERROR, "Insufficent memory. Accept-Language header crunched without replacement."); } else { log_error(LOG_LEVEL_HEADER, "Accept-Language header crunched and replaced with: %s", *header); } } return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } /********************************************************************* * * Function : crunch_client_header * * Description : Crunch client header if it matches a string supplied by the * user. Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success and always succeeds * *********************************************************************/ static jb_err crunch_client_header(struct client_state *csp, char **header) { const char *crunch_pattern; /* Do we feel like crunching? */ if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER)) { crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER]; /* Is the current header the lucky one? */ if (strstr(*header, crunch_pattern)) { log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern); freez(*header); } } return JB_ERR_OK; } /********************************************************************* * * Function : client_uagent * * Description : Handle the "user-agent" config setting properly * and remember its original value to enable browser * bug workarounds. Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_uagent(struct client_state *csp, char **header) { const char *newval; if ((csp->action->flags & ACTION_HIDE_USER_AGENT) == 0) { return JB_ERR_OK; } newval = csp->action->string[ACTION_STRING_USER_AGENT]; if (newval == NULL) { return JB_ERR_OK; } freez(*header); *header = strdup("User-Agent: "); string_append(header, newval); log_error(LOG_LEVEL_HEADER, "Modified: %s", *header); return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } /********************************************************************* * * Function : client_ua * * Description : Handle "ua-" headers properly. Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_ua(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0) { log_error(LOG_LEVEL_HEADER, "crunched User-Agent!"); freez(*header); } return JB_ERR_OK; } /********************************************************************* * * Function : client_from * * Description : Handle the "from" config setting properly. * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_from(struct client_state *csp, char **header) { const char *newval; if ((csp->action->flags & ACTION_HIDE_FROM) == 0) { return JB_ERR_OK; } freez(*header); newval = csp->action->string[ACTION_STRING_FROM]; /* * Are we blocking the e-mail address? */ if ((newval == NULL) || (0 == strcmpic(newval, "block")) ) { log_error(LOG_LEVEL_HEADER, "crunched From!"); return JB_ERR_OK; } log_error(LOG_LEVEL_HEADER, " modified"); *header = strdup("From: "); string_append(header, newval); return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK; } /********************************************************************* * * Function : client_send_cookie * * Description : Crunches the "cookie" header if necessary. * Called from `sed'. * * XXX: Stupid name, doesn't send squat. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_send_cookie(struct client_state *csp, char **header) { if (csp->action->flags & ACTION_NO_COOKIE_READ) { log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header); freez(*header); } return JB_ERR_OK; } /********************************************************************* * * Function : client_x_forwarded * * Description : Handle the "x-forwarded-for" config setting properly, * also used in the add_client_headers list. Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ jb_err client_x_forwarded(struct client_state *csp, char **header) { if ((csp->action->flags & ACTION_HIDE_FORWARDED) != 0) { freez(*header); log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!"); } return JB_ERR_OK; } /********************************************************************* * * Function : client_max_forwards * * Description : If the HTTP method is OPTIONS or TRACE, subtract one * from the value of the Max-Forwards header field. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_max_forwards(struct client_state *csp, char **header) { int max_forwards; if ((0 == strcmpic(csp->http->gpc, "trace")) || (0 == strcmpic(csp->http->gpc, "options"))) { assert(*(*header+12) == ':'); if (1 == sscanf(*header+12, ": %u", &max_forwards)) { if (max_forwards > 0) { snprintf(*header, strlen(*header)+1, "Max-Forwards: %u", --max_forwards); log_error(LOG_LEVEL_HEADER, "Max-Forwards value for %s request reduced to %u.", csp->http->gpc, max_forwards); } else if (max_forwards < 0) { log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header); freez(*header); } } else { log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header); freez(*header); } } return JB_ERR_OK; } /********************************************************************* * * Function : client_host * * Description : If the request URI did not contain host and * port information, parse and evaluate the Host * header field. * * Also, kill ill-formed HOST: headers as sent by * Apple's iTunes software when used with a proxy. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_host(struct client_state *csp, char **header) { char *p, *q; /* * If the header field name is all upper-case, chances are that it's * an ill-formed one from iTunes. BTW, killing innocent headers here is * not a problem -- they are regenerated later. */ if ((*header)[1] == 'O') { log_error(LOG_LEVEL_HEADER, "Killed all-caps Host header line: %s", *header); freez(*header); return JB_ERR_OK; } if (!csp->http->hostport || (*csp->http->hostport == '*') || *csp->http->hostport == ' ' || *csp->http->hostport == '\0') { if (NULL == (p = strdup((*header)+6))) { return JB_ERR_MEMORY; } chomp(p); if (NULL == (q = strdup(p))) { freez(p); return JB_ERR_MEMORY; } freez(csp->http->hostport); csp->http->hostport = p; freez(csp->http->host); csp->http->host = q; q = strchr(csp->http->host, ':'); if (q != NULL) { /* Terminate hostname and evaluate port string */ *q++ = '\0'; csp->http->port = atoi(q); } else { csp->http->port = csp->http->ssl ? 443 : 80; } log_error(LOG_LEVEL_HEADER, "New host and port from Host field: %s = %s:%d", csp->http->hostport, csp->http->host, csp->http->port); } /* Signal client_host_adder() to return right away */ csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET; return JB_ERR_OK; } /********************************************************************* * * Function : client_if_modified_since * * Description : Remove or modify the If-Modified-Since header. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_if_modified_since(struct client_state *csp, char **header) { char newheader[50]; #ifdef HAVE_GMTIME_R struct tm gmt; #endif struct tm *timeptr = NULL; time_t tm = 0; const char *newval; long int rtime; long int hours, minutes, seconds; int negative = 0; char * endptr; if ( 0 == strcmpic(*header, "If-Modified-Since: Wed, 08 Jun 1955 12:00:00 GMT")) { /* * The client got an error message because of a temporary problem, * the problem is gone and the client now tries to revalidate our * error message on the real server. The revalidation would always * end with the transmission of the whole document and there is * no need to expose the bogus If-Modified-Since header. */ log_error(LOG_LEVEL_HEADER, "Crunching useless If-Modified-Since header."); freez(*header); } else if (csp->action->flags & ACTION_HIDE_IF_MODIFIED_SINCE) { newval = csp->action->string[ACTION_STRING_IF_MODIFIED_SINCE]; if ((0 == strcmpic(newval, "block"))) { log_error(LOG_LEVEL_HEADER, "Crunching %s", *header); freez(*header); } else /* add random value */ { const char *header_time = *header + sizeof("If-Modified-Since:"); if (JB_ERR_OK != parse_header_time(header_time, &tm)) { log_error(LOG_LEVEL_HEADER, "Couldn't parse: %s in %s (crunching!)", header_time, *header); freez(*header); } else { rtime = strtol(newval, &endptr, 0); if (rtime) { log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %d minut%s)", *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es"); if (rtime < 0) { rtime *= -1; negative = 1; } rtime *= 60; rtime = pick_from_range(rtime); } else { log_error(LOG_LEVEL_ERROR, "Random range is 0. Assuming time transformation test.", *header); } tm += rtime * (negative ? -1 : 1); #ifdef HAVE_GMTIME_R timeptr = gmtime_r(&tm, &gmt); #elif FEATURE_PTHREAD pthread_mutex_lock(&gmtime_mutex); timeptr = gmtime(&tm); pthread_mutex_unlock(&gmtime_mutex); #else timeptr = gmtime(&tm); #endif strftime(newheader, sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr); freez(*header); *header = strdup("If-Modified-Since: "); string_append(header, newheader); if (*header == NULL) { log_error(LOG_LEVEL_HEADER, "Insufficent memory, header crunched without replacement."); return JB_ERR_MEMORY; } if (LOG_LEVEL_HEADER & debug) /* Save cycles if the user isn't interested. */ { hours = rtime / 3600; minutes = rtime / 60 % 60; seconds = rtime % 60; log_error(LOG_LEVEL_HEADER, "Randomized: %s (%s %d hou%s %d minut%s %d second%s", *header, (negative) ? "subtracted" : "added", hours, (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)"); } } } } return JB_ERR_OK; } /********************************************************************* * * Function : client_if_none_match * * Description : Remove the If-None-Match header. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_if_none_match(struct client_state *csp, char **header) { if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH) { log_error(LOG_LEVEL_HEADER, "Crunching %s", *header); freez(*header); } return JB_ERR_OK; } /********************************************************************* * * Function : client_x_filter * * Description : Disables filtering if the client set "X-Filter: No". * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success * *********************************************************************/ jb_err client_x_filter(struct client_state *csp, char **header) { if ( 0 == strcmpic(*header, "X-Filter: No")) { if (!(csp->config->feature_flags & RUNTIME_FEATURE_HTTP_TOGGLE)) { log_error(LOG_LEVEL_INFO, "Ignored the client's request to fetch without filtering."); } else { if (csp->action->flags & ACTION_FORCE_TEXT_MODE) { log_error(LOG_LEVEL_HEADER, "force-text-mode overruled the client's request to fetch without filtering!"); } else { csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */ csp->flags |= CSP_FLAG_NO_FILTERING; log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering."); } log_error(LOG_LEVEL_HEADER, "Crunching %s", *header); freez(*header); } } return JB_ERR_OK; } /********************************************************************* * * Function : client_range * * Description : Removes Range, Request-Range and If-Range headers if * content filtering is enabled. If the client's version * of the document has been altered by Privoxy, the server * could interpret the range differently than the client * intended in which case the user could end up with * corrupted content. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK * *********************************************************************/ static jb_err client_range(struct client_state *csp, char **header) { if (content_filters_enabled(csp)) { log_error(LOG_LEVEL_HEADER, "Content filtering is enabled." " Crunching: \'%s\' to prevent range-mismatch problems.", *header); freez(*header); } return JB_ERR_OK; } /* the following functions add headers directly to the header list */ /********************************************************************* * * Function : client_host_adder * * Description : Adds the Host: header field if it is missing. * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_host_adder(struct client_state *csp) { char *p; jb_err err; if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET) { /* Header already set by the client, nothing to do. */ return JB_ERR_OK; } if ( !csp->http->hostport || !*(csp->http->hostport)) { /* XXX: When does this happen and why is it OK? */ log_error(LOG_LEVEL_INFO, "Weirdness in client_host_adder detected and ignored."); return JB_ERR_OK; } /* * remove 'user:pass@' from 'proto://user:pass@host' */ if ( (p = strchr( csp->http->hostport, '@')) != NULL ) { p++; } else { p = csp->http->hostport; } /* XXX: Just add it, we already made sure that it will be unique */ log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p); err = enlist_unique_header(csp->headers, "Host", p); return err; } /********************************************************************* * * Function : client_cookie_adder * * Description : Used in the add_client_headers list to add "wafers". * Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ jb_err client_cookie_adder(struct client_state *csp) { char *tmp; struct list_entry *wafer; struct list_entry *wafer_list; jb_err err; /* * If the user has not supplied any wafers, and the user has not * told us to suppress the vanilla wafer, then send the vanilla wafer. */ if ((0 != (csp->action->flags & ACTION_VANILLA_WAFER)) && list_is_empty(csp->action->multi[ACTION_MULTI_WAFER])) { enlist(csp->action->multi[ACTION_MULTI_WAFER], VANILLA_WAFER); } wafer_list = csp->action->multi[ACTION_MULTI_WAFER]->first; if (NULL == wafer_list) { /* Nothing to do */ return JB_ERR_OK; } tmp = strdup("Cookie: "); for (wafer = wafer_list; (NULL != tmp) && (NULL != wafer); wafer = wafer->next) { if (wafer != wafer_list) { /* As this isn't the first wafer, we need a delimiter. */ string_append(&tmp, "; "); } string_join(&tmp, cookie_encode(wafer->str)); } if (tmp == NULL) { return JB_ERR_MEMORY; } log_error(LOG_LEVEL_HEADER, "addh: %s", tmp); err = enlist(csp->headers, tmp); free(tmp); return err; } #if 0 /********************************************************************* * * Function : client_accept_encoding_adder * * Description : Add an Accept-Encoding header to the client's request * that disables compression if the action applies, and * the header is not already there. Called from `sed'. * Note: For HTTP/1.0, the absence of the header is enough. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_accept_encoding_adder(struct client_state *csp) { if ( ((csp->action->flags & ACTION_NO_COMPRESSION) != 0) && (!strcmpic(csp->http->ver, "HTTP/1.1")) ) { return enlist_unique(csp->headers, "Accept-Encoding: identity;q=1.0, *;q=0", 16); } return JB_ERR_OK; } #endif /********************************************************************* * * Function : client_xtra_adder * * Description : Used in the add_client_headers list. Called from `sed'. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err client_xtra_adder(struct client_state *csp) { struct list_entry *lst; jb_err err; for (lst = csp->action->multi[ACTION_MULTI_ADD_HEADER]->first; lst ; lst = lst->next) { log_error(LOG_LEVEL_HEADER, "addh: %s", lst->str); err = enlist(csp->headers, lst->str); if (err) { return err; } } return JB_ERR_OK; } /********************************************************************* * * Function : connection_close_adder * * Description : "Temporary" fix for the needed but missing HTTP/1.1 * support. Adds a "Connection: close" header to csp->headers * unless the header was already present. Called from `sed'. * * FIXME: This whole function shouldn't be neccessary! * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err connection_close_adder(struct client_state *csp) { const unsigned int flags = csp->flags; /* * Return right away if * * - we're parsing server headers and the server header * "Connection: close" is already set, or if * * - we're parsing client headers and the client header * "Connection: close" is already set. */ if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE && flags & CSP_FLAG_SERVER_CONNECTION_CLOSE_SET) ||(!(flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE) && flags & CSP_FLAG_CLIENT_CONNECTION_CLOSE_SET)) { return JB_ERR_OK; } log_error(LOG_LEVEL_HEADER, "Adding: Connection: close"); return enlist(csp->headers, "Connection: close"); } /********************************************************************* * * Function : server_http * * Description : - Save the HTTP Status into csp->http->status * - Set CT_TABOO to prevent filtering if the answer * is a partial range (HTTP status 206) * - Rewrite HTTP/1.1 answers to HTTP/1.0 if +downgrade * action applies. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_http(struct client_state *csp, char **header) { sscanf(*header, "HTTP/%*d.%*d %d", &(csp->http->status)); if (csp->http->status == 206) { csp->content_type = CT_TABOO; } if ((csp->action->flags & ACTION_DOWNGRADE) != 0) { /* XXX: Should we do a real validity check here? */ if (strlen(*header) > 8) { (*header)[7] = '0'; log_error(LOG_LEVEL_HEADER, "Downgraded answer to HTTP/1.0"); } else { /* * XXX: Should we block the request or * enlist a valid status code line here? */ log_error(LOG_LEVEL_INFO, "Malformed server response detected. " "Downgrading to HTTP/1.0 impossible."); } } return JB_ERR_OK; } /********************************************************************* * * Function : server_set_cookie * * Description : Handle the server "cookie" header properly. * Log cookie to the jar file. Then "crunch", * accept or rewrite it to a session cookie. * Called from `sed'. * * TODO: Allow the user to specify a new expiration * time to cause the cookie to expire even before the * browser is closed. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * 2 : header = On input, pointer to header to modify. * On output, pointer to the modified header, or NULL * to remove the header. This function frees the * original string if necessary. * * Returns : JB_ERR_OK on success, or * JB_ERR_MEMORY on out-of-memory error. * *********************************************************************/ static jb_err server_set_cookie(struct client_state *csp, char **header) { time_t now; time_t cookie_time; struct tm tm_now; time(&now); #ifdef FEATURE_COOKIE_JAR if (csp->config->jar) { /* * Write timestamp into outbuf. * * Complex because not all OSs have tm_gmtoff or * the %z field in strftime() */ char tempbuf[ BUFFER_SIZE ]; #ifdef HAVE_LOCALTIME_R tm_now = *localtime_r(&now, &tm_now); #elif FEATURE_PTHREAD pthread_mutex_lock(&localtime_mutex); tm_now = *localtime (&now); pthread_mutex_unlock(&localtime_mutex); #else tm_now = *localtime (&now); #endif strftime(tempbuf, BUFFER_SIZE-6, "%b %d %H:%M:%S ", &tm_now); /* strlen("set-cookie: ") = 12 */ fprintf(csp->config->jar, "%s %s\t%s\n", tempbuf, csp->http->host, *header + 12); } #endif /* def FEATURE_COOKIE_JAR */ if ((csp->action->flags & ACTION_NO_COOKIE_SET) != 0) { log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header); freez(*header); } else if ((csp->action->flags & ACTION_NO_COOKIE_KEEP) != 0) { /* Flag whether or not to log a message */ int changed = 0; /* A variable to store the tag we're working on */ char *cur_tag; /* Skip "Set-Cookie:" (11 characters) in header */ cur_tag = *header + 11; /* skip whitespace between "Set-Cookie:" and value */ while (*cur_tag && ijb_isspace(*cur_tag)) { cur_tag++; } /* Loop through each tag in the cookie */ while (*cur_tag) { /* Find next tag */ char *next_tag = strchr(cur_tag, ';'); if (next_tag != NULL) { /* Skip the ';' character itself */ next_tag++; /* skip whitespace ";" and start of tag */ while (*next_tag && ijb_isspace(*next_tag)) { next_tag++; } } else { /* "Next tag" is the end of the string */ next_tag = cur_tag + strlen(cur_tag); } /* * Check the expiration date to see * if the cookie is still valid, if yes, * rewrite it to a session cookie. */ if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8)) { char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */ /* Did we detect the date properly? */ if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time)) { /* * Nope, treat it as if it was still valid. * * XXX: Should we remove the whole cookie instead? */ log_error(LOG_LEVEL_ERROR, "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url); memmove(cur_tag, next_tag, strlen(next_tag) + 1); changed = 1; } else { /* * Yes. Check if the cookie is still valid. * * If the cookie is already expired it's probably * a delete cookie and even if it isn't, the browser * will discard it anyway. */ /* * XXX: timegm() isn't available on some AmigaOS * versions and our replacement doesn't work. * * Our options are to either: * * - disable session-cookies-only completely if timegm * is missing, * * - to simply remove all expired tags, like it has * been done until Privoxy 3.0.6 and to live with * the consequence that it can cause login/logout * problems on servers that don't validate their * input properly, or * * - to replace it with mktime in which * case there is a slight chance of valid cookies * passing as already expired. * * This is the way it's currently done and it's not * as bad as it sounds. If the missing GMT offset is * enough to change the result of the expiration check * the cookie will be only valid for a few hours * anyway, which in many cases will be shorter * than a browser session. */ if (cookie_time - now < 0) { log_error(LOG_LEVEL_HEADER, "Cookie \'%s\' is already expired and can pass unmodified.", *header); /* Just in case some clown sets more then one expiration date */ cur_tag = next_tag; } else { /* * Still valid, delete expiration date by copying * the rest of the string over it. * * (Note that we cannot just use "strcpy(cur_tag, next_tag)", * since the behaviour of strcpy is undefined for overlapping * strings.) */ memmove(cur_tag, next_tag, strlen(next_tag) + 1); /* That changed the header, need to issue a log message */ changed = 1; /* * Note that the next tag has now been moved to *cur_tag, * so we do not need to update the cur_tag pointer. */ } } } else { /* Move on to next cookie tag */ cur_tag = next_tag; } } if (changed) { assert(NULL != *header); log_error(LOG_LEVEL_HEADER, "Cookie rewritten to a temporary one: %s", *header); } } return JB_ERR_OK; } #ifdef FEATURE_FORCE_LOAD /********************************************************************* * * Function : strclean * * Description : In-Situ-Eliminate all occurances of substring in * string * * Parameters : * 1 : string = string to clean * 2 : substring = substring to eliminate * * Returns : Number of eliminations * *********************************************************************/ int strclean(const char *string, const char *substring) { int hits = 0; size_t len; char *pos, *p; len = strlen(substring); while((pos = strstr(string, substring)) != NULL) { p = pos + len; do { *(p - len) = *p; } while (*p++ != '\0'); hits++; } return(hits); } #endif /* def FEATURE_FORCE_LOAD */ /********************************************************************* * * Function : parse_header_time * * Description : Parses time formats used in HTTP header strings * to get the numerical respresentation. * * Parameters : * 1 : header_time = HTTP header time as string. * 2 : result = storage for header_time in seconds * * Returns : JB_ERR_OK if the time format was recognized, or * JB_ERR_PARSE otherwise. * *********************************************************************/ static jb_err parse_header_time(const char *header_time, time_t *result) { struct tm gmt; /* * Zero out gmt to prevent time zone offsets. * * While this is only necessary on some platforms * (mingw32 for example), I don't know how to * detect these automatically and doing it everywhere * shouldn't hurt. */ memset(&gmt, 0, sizeof(gmt)); /* Tue, 02 Jun 2037 20:00:00 */ if ((NULL == strptime(header_time, "%a, %d %b %Y %H:%M:%S", &gmt)) /* Tue, 02-Jun-2037 20:00:00 */ && (NULL == strptime(header_time, "%a, %d-%b-%Y %H:%M:%S", &gmt)) /* Tue, 02-Jun-37 20:00:00 */ && (NULL == strptime(header_time, "%a, %d-%b-%y %H:%M:%S", &gmt)) /* Tuesday, 02-Jun-2037 20:00:00 */ && (NULL == strptime(header_time, "%A, %d-%b-%Y %H:%M:%S", &gmt)) /* Tuesday Jun 02 20:00:00 2037 */ && (NULL == strptime(header_time, "%A %b %d %H:%M:%S %Y", &gmt))) { return JB_ERR_PARSE; } *result = timegm(&gmt); return JB_ERR_OK; } /********************************************************************* * * Function : get_destination_from_headers * * Description : Parse the "Host:" header to get the request's destination. * Only needed if the client's request was forcefully * redirected into Privoxy. * * Code mainly copied from client_host() which is currently * run too late for this purpose. * * Parameters : * 1 : headers = List of headers (one of them hopefully being * the "Host:" header) * 2 : http = storage for the result (host, port and hostport). * * Returns : JB_ERR_MEMORY in case of memory problems, * JB_ERR_PARSE if the host header couldn't be found, * JB_ERR_OK otherwise. * *********************************************************************/ jb_err get_destination_from_headers(const struct list *headers, struct http_request *http) { char *q; char *p; char *host; host = get_header_value(headers, "Host:"); if (NULL == host) { log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found."); return JB_ERR_PARSE; } if (NULL == (p = strdup((host)))) { log_error(LOG_LEVEL_ERROR, "Out of memory while parsing \"Host:\" header"); return JB_ERR_MEMORY; } chomp(p); if (NULL == (q = strdup(p))) { freez(p); log_error(LOG_LEVEL_ERROR, "Out of memory while parsing \"Host:\" header"); return JB_ERR_MEMORY; } freez(http->hostport); http->hostport = p; freez(http->host); http->host = q; q = strchr(http->host, ':'); if (q != NULL) { /* Terminate hostname and evaluate port string */ *q++ = '\0'; http->port = atoi(q); } else { http->port = http->ssl ? 443 : 80; } /* Rebuild request URL */ freez(http->url); http->url = strdup(http->ssl ? "https://" : "http://"); string_append(&http->url, http->hostport); string_append(&http->url, http->path); if (http->url == NULL) { return JB_ERR_MEMORY; } log_error(LOG_LEVEL_HEADER, "Destination extracted from \"Host:\" header. New request URL: %s", http->url); return JB_ERR_OK; } /********************************************************************* * * Function : create_forged_referrer * * Description : Helper for client_referrer to forge a referer as * 'http://[hostname:port/' to fool stupid * checks for in-site links * * Parameters : * 1 : header = Pointer to header pointer * 2 : hostport = Host and optionally port as string * * Returns : JB_ERR_OK in case of success, or * JB_ERR_MEMORY in case of memory problems. * *********************************************************************/ static jb_err create_forged_referrer(char **header, const char *hostport) { assert(NULL == *header); *header = strdup("Referer: http://"); string_append(header, hostport); string_append(header, "/"); if (NULL == *header) { return JB_ERR_MEMORY; } log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header); return JB_ERR_OK; } /********************************************************************* * * Function : create_fake_referrer * * Description : Helper for client_referrer to create a fake referrer * based on a string supplied by the user. * * Parameters : * 1 : header = Pointer to header pointer * 2 : hosthost = Referrer to fake * * Returns : JB_ERR_OK in case of success, or * JB_ERR_MEMORY in case of memory problems. * *********************************************************************/ static jb_err create_fake_referrer(char **header, const char *fake_referrer) { assert(NULL == *header); if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8))) { log_error(LOG_LEVEL_HEADER, "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer); } *header = strdup("Referer: "); string_append(header, fake_referrer); if (NULL == *header) { return JB_ERR_MEMORY; } log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header); return JB_ERR_OK; } /********************************************************************* * * Function : handle_conditional_hide_referrer_parameter * * Description : Helper for client_referrer to crunch or forge * the referrer header if the host has changed. * * Parameters : * 1 : header = Pointer to header pointer * 2 : host = The target host (may include the port) * 3 : parameter_conditional_block = Boolean to signal * if we're in conditional-block mode. If not set, * we're in conditional-forge mode. * * Returns : JB_ERR_OK in case of success, or * JB_ERR_MEMORY in case of memory problems. * *********************************************************************/ static jb_err handle_conditional_hide_referrer_parameter(char **header, const char *host, const int parameter_conditional_block) { char *referer = strdup(*header); const size_t hostlenght = strlen(host); if (NULL == referer) { freez(*header); return JB_ERR_MEMORY; } /* referer begins with 'Referer: http[s]://' */ if (hostlenght < (strlen(referer)-17)) { /* * Shorten referer to make sure the referer is blocked * if www.example.org/www.example.com-shall-see-the-referer/ * links to www.example.com/ */ referer[hostlenght+17] = '\0'; } if (NULL == strstr(referer, host)) { /* Host has changed */ if (parameter_conditional_block) { log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header); freez(*header); } else { freez(*header); freez(referer); return create_forged_referrer(header, host); } } freez(referer); return JB_ERR_OK; } /* Local Variables: tab-width: 3 end: */