X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=filters.c;h=b2940c1b8f0097b0b2699e7ca126191526a911a8;hp=6f16d847e0f1cab37a56e8ac761f5d9f046e8de6;hb=f4107f65b676b63a199fe4230e58695757f9f199;hpb=97110184221edacdb7d4dfc29de0e38d63f4d831 diff --git a/filters.c b/filters.c index 6f16d847..b2940c1b 100644 --- a/filters.c +++ b/filters.c @@ -1,4 +1,4 @@ -const char filters_rcs[] = "$Id: filters.c,v 1.52 2002/03/24 16:35:57 jongfoster Exp $"; +const char filters_rcs[] = "$Id: filters.c,v 1.103 2008/03/06 16:33:45 fabiankeil Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/filters.c,v $ @@ -9,9 +9,11 @@ const char filters_rcs[] = "$Id: filters.c,v 1.52 2002/03/24 16:35:57 jongfoster * `block_url', `url_actions', `domain_split', * `filter_popups', `forward_url', 'redirect_url', * `ij_untrusted_url', `intercept_url', `pcrs_filter_respose', - * 'ijb_send_banner', and `trust_url' + * `ijb_send_banner', `trust_url', `gif_deanimate_response', + * `jpeg_inspect_response', `execute_single_pcrs_command', + * `rewrite_url', `get_last_url' * - * Copyright : Written by and Copyright (C) 2001 the SourceForge + * Copyright : Written by and Copyright (C) 2001, 2004-2008 the SourceForge * Privoxy team. http://www.privoxy.org/ * * Based on the Internet Junkbuster originally written @@ -38,6 +40,244 @@ const char filters_rcs[] = "$Id: filters.c,v 1.52 2002/03/24 16:35:57 jongfoster * * Revisions : * $Log: filters.c,v $ + * Revision 1.103 2008/03/06 16:33:45 fabiankeil + * If limit-connect isn't used, don't limit CONNECT requests to port 443. + * + * Revision 1.102 2008/03/01 14:00:44 fabiankeil + * Let the block action take the reason for the block + * as argument and show it on the "blocked" page. + * + * Revision 1.101 2008/02/23 16:57:12 fabiankeil + * Rename url_actions() to get_url_actions() and let it + * use the standard parameter ordering. + * + * Revision 1.100 2008/02/23 16:33:43 fabiankeil + * Let forward_url() use the standard parameter ordering + * and mark its second parameter immutable. + * + * Revision 1.99 2008/02/03 13:57:58 fabiankeil + * Add SOCKS5 support for forward-override{}. + * + * Revision 1.98 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 1.97 2007/11/30 15:37:03 fabiankeil + * Use freez instead of free. + * + * Revision 1.96 2007/10/19 16:53:28 fabiankeil + * Add helper function to check if any content filters are enabled. + * + * Revision 1.95 2007/10/17 19:31:20 fabiankeil + * Omitting the zero chunk that ends the chunk transfer encoding seems + * to be the new black. Log the problem and continue filtering anyway. + * + * Revision 1.94 2007/09/29 13:20:20 fabiankeil + * Remove two redundant and one useless log messages. + * + * Revision 1.93 2007/09/29 10:21:16 fabiankeil + * - Move get_filter_function() from jcc.c to filters.c + * so the filter functions can be static. + * - Don't bother filtering body-less responses. + * + * Revision 1.92 2007/09/28 16:38:55 fabiankeil + * - Execute content filters through execute_content_filter(). + * - Add prepare_for_filtering() so filter functions don't have to + * care about de-chunking and decompression. As a side effect this enables + * decompression for gif_deanimate_response() and jpeg_inspect_response(). + * - Change remove_chunked_transfer_coding()'s return type to jb_err. + * Some clowns feel like chunking empty responses in which case + * (size == 0) is valid but previously would be interpreted as error. + * + * Revision 1.91 2007/09/02 15:31:20 fabiankeil + * Move match_portlist() from filter.c to urlmatch.c. + * It's used for url matching, not for filtering. + * + * Revision 1.90 2007/09/02 12:44:17 fabiankeil + * Remove newline at the end of a log_error() message. + * + * Revision 1.89 2007/08/05 13:42:23 fabiankeil + * #1763173 from Stefan Huehner: declare some more functions static. + * + * Revision 1.88 2007/06/01 16:41:11 fabiankeil + * Add forward-override{} to change the forwarding settings through + * action sections. This is mainly interesting to forward different + * clients differently (for example based on User-Agent or request + * origin). + * + * Revision 1.87 2007/04/30 15:53:10 fabiankeil + * Make sure filters with dynamic jobs actually use them. + * + * Revision 1.86 2007/04/30 15:03:28 fabiankeil + * - Introduce dynamic pcrs jobs that can resolve variables. + * - Don't run redirect functions more than once, + * unless they are activated more than once. + * + * Revision 1.85 2007/03/21 12:24:47 fabiankeil + * - Log the content size after decompression in decompress_iob() + * instead of pcrs_filter_response(). + * + * Revision 1.84 2007/03/20 15:16:34 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". + * + * Revision 1.83 2007/03/17 15:20:05 fabiankeil + * New config option: enforce-blocks. + * + * Revision 1.82 2007/03/13 11:28:43 fabiankeil + * - Fix port handling in acl_addr() and use a temporary acl spec + * copy so error messages don't contain a truncated version. + * - Log size of iob before and after decompression. + * + * Revision 1.81 2007/03/05 14:40:53 fabiankeil + * - Cosmetical changes for LOG_LEVEL_RE_FILTER messages. + * - Hide the "Go there anyway" link for blocked CONNECT + * requests where going there anyway doesn't work anyway. + * + * Revision 1.80 2007/02/07 10:55:20 fabiankeil + * - Save the reason for generating http_responses. + * - Block (+block) with status code 403 instead of 404. + * - Use a different kludge to remember a failed decompression. + * + * Revision 1.79 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 1.78 2007/01/28 13:41:18 fabiankeil + * - Add HEAD support to finish_http_response. + * - Add error favicon to internal HTML error messages. + * + * Revision 1.77 2007/01/12 15:36:44 fabiankeil + * Mark *csp as immutable for is_untrusted_url() + * and is_imageurl(). Closes FR 1237736. + * + * Revision 1.76 2007/01/01 19:36:37 fabiankeil + * Integrate a modified version of Wil Mahan's + * zlib patch (PR #895531). + * + * Revision 1.75 2006/12/29 18:30:46 fabiankeil + * Fixed gcc43 conversion warnings, + * changed sprintf calls to snprintf. + * + * Revision 1.74 2006/12/24 17:37:38 fabiankeil + * Adjust comment in pcrs_filter_response() + * to recent pcrs changes. Hohoho. + * + * Revision 1.73 2006/12/23 16:01:02 fabiankeil + * Don't crash if pcre returns an error code + * that pcrs didn't expect. Fixes BR 1621173. + * + * Revision 1.72 2006/12/22 18:52:53 fabiankeil + * Modified is_untrusted_url to complain in case of + * write errors and to give a reason when adding new + * entries to the trustfile. Closes FR 1097611. + * + * Revision 1.71 2006/12/22 14:24:52 fabiankeil + * Skip empty filter files in pcrs_filter_response, + * but don't ignore the ones that come afterwards. + * Fixes parts of BR 1619208. + * + * Revision 1.70 2006/12/09 13:33:15 fabiankeil + * Added some sanity checks for get_last_url(). + * Fixed possible segfault caused by my last commit. + * + * Revision 1.69 2006/12/08 12:39:13 fabiankeil + * Let get_last_url() catch https URLs as well. + * + * Revision 1.68 2006/12/05 14:45:48 fabiankeil + * Make sure get_last_url() behaves like advertised + * and fast-redirects{} can be combined with redirect{}. + * + * Revision 1.67 2006/11/28 15:19:43 fabiankeil + * Implemented +redirect{s@foo@bar@} to generate + * a redirect based on a rewritten version of the + * original URL. + * + * Revision 1.66 2006/09/23 13:26:38 roro + * Replace TABs by spaces in source code. + * + * Revision 1.65 2006/09/21 12:54:43 fabiankeil + * Fix +redirect{}. Didn't work with -fast-redirects. + * + * Revision 1.64 2006/08/31 10:55:49 fabiankeil + * Block requests for untrusted URLs with status + * code 403 instead of 200. + * + * Revision 1.63 2006/08/31 10:11:28 fabiankeil + * Don't free p which is still in use and will be later + * freed by free_map(). Don't claim the referrer is unknown + * when the client didn't set one. + * + * Revision 1.62 2006/08/14 00:27:47 david__schmidt + * Feature request 595948: Re-Filter logging in single line + * + * Revision 1.61 2006/08/03 02:46:41 david__schmidt + * Incorporate Fabian Keil's patch work: http://www.fabiankeil.de/sourcecode/privoxy/ + * + * Revision 1.60 2006/07/18 14:48:46 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 1.58.2.9 2006/01/29 23:10:56 david__schmidt + * Multiple filter file support + * + * Revision 1.58.2.8 2005/05/07 21:50:55 david__schmidt + * A few memory leaks plugged (mostly on error paths) + * + * Revision 1.58.2.7 2004/10/03 12:53:32 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 1.58.2.6 2003/12/06 22:18:27 gliptak + * Correcting compile problem with FEATURE_IMAGE_BLOCKING + * + * Revision 1.58.2.5 2003/11/11 13:10:31 oes + * Fixed bug #839859: "See why" link URL now gets url-encoded. + * + * Revision 1.58.2.4 2003/02/28 12:52:45 oes + * Fixed a typo + * + * Revision 1.58.2.3 2002/09/25 14:51:51 oes + * Added basic support for OPTIONS and TRACE HTTP methods: + * New function direct_response which handles OPTIONS and + * TRACE requests whose Max-Forwards header field is zero. + * + * Revision 1.58.2.2 2002/08/01 17:18:28 oes + * Fixed BR 537651 / SR 579724 (MSIE image detect improper for IE/Mac) + * + * Revision 1.58.2.1 2002/07/26 15:18:53 oes + * - Bugfix: Executing a filters without jobs no longer results in + * turing off *all* filters. + * - Security fix: Malicious web servers can't cause a seg fault + * through bogus chunk sizes anymore + * + * Revision 1.58 2002/04/24 02:11:17 oes + * Jon's multiple AF patch: url_actions now evaluates rules + * from all AFs. + * + * Revision 1.57 2002/04/08 20:38:34 swa + * fixed JB spelling + * + * Revision 1.56 2002/04/05 15:51:24 oes + * - bugfix: error-pages now get correct request protocol + * - fix for invalid HTML in trust info + * + * Revision 1.55 2002/04/02 16:13:51 oes + * Fix: No "Go there anyway" for SSL + * + * Revision 1.54 2002/04/02 14:55:56 oes + * Bugfix: is_untrusted_url() now depends on FEATURE_TRUST, not FEATURE_COOKIE_JAR + * + * Revision 1.53 2002/03/26 22:29:54 swa + * we have a new homepage! + * * Revision 1.52 2002/03/24 16:35:57 jongfoster * Removing logo * @@ -357,7 +597,7 @@ const char filters_rcs[] = "$Id: filters.c,v 1.52 2002/03/24 16:35:57 jongfoster * a lot! ;-) * * Revision 1.3 2001/05/20 16:44:47 jongfoster - * Removing last hardcoded JunkBusters.com URLs. + * Removing last hardcoded Junkbusters.com URLs. * * Revision 1.2 2001/05/20 01:21:20 jongfoster * Version 2.9.4 checkin. @@ -414,6 +654,7 @@ const char filters_rcs[] = "$Id: filters.c,v 1.52 2002/03/24 16:35:57 jongfoster #include "list.h" #include "deanimate.h" #include "urlmatch.h" +#include "loaders.h" #ifdef _WIN32 #include "win32.h" @@ -430,6 +671,8 @@ const char filters_h_rcs[] = FILTERS_H_VERSION; */ #define ijb_isdigit(__X) isdigit((int)(unsigned char)(__X)) +static jb_err remove_chunked_transfer_coding(char *buffer, size_t *size); +static jb_err prepare_for_filtering(struct client_state *csp); #ifdef FEATURE_ACL /********************************************************************* @@ -505,20 +748,33 @@ int block_acl(struct access_control_addr *dst, struct client_state *csp) * Returns : 0 => Ok, everything else is an error. * *********************************************************************/ -int acl_addr(char *aspec, struct access_control_addr *aca) +int acl_addr(const char *aspec, struct access_control_addr *aca) { - int i, masklength, port; + int i, masklength; + long port; char *p; + char *acl_spec = NULL; masklength = 32; port = 0; - if ((p = strchr(aspec, '/')) != NULL) + /* + * Use a temporary acl spec copy so we can log + * the unmodified original in case of parse errors. + */ + acl_spec = strdup(aspec); + if (acl_spec == NULL) { - *p++ = '\0'; + /* XXX: This will be logged as parse error. */ + return(-1); + } + if ((p = strchr(acl_spec, '/')) != NULL) + { + *p++ = '\0'; if (ijb_isdigit(*p) == 0) { + freez(acl_spec); return(-1); } masklength = atoi(p); @@ -526,26 +782,32 @@ int acl_addr(char *aspec, struct access_control_addr *aca) if ((masklength < 0) || (masklength > 32)) { + freez(acl_spec); return(-1); } - if ((p = strchr(aspec, ':')) != NULL) + if ((p = strchr(acl_spec, ':')) != NULL) { + char *endptr; + *p++ = '\0'; + port = strtol(p, &endptr, 10); - if (ijb_isdigit(*p) == 0) + if (port <= 0 || port > 65535 || *endptr != '\0') { + freez(acl_spec); return(-1); } - port = atoi(p); } - aca->port = port; + aca->port = (unsigned long)port; - aca->addr = ntohl(resolve_hostname_to_ip(aspec)); + aca->addr = ntohl(resolve_hostname_to_ip(acl_spec)); + freez(acl_spec); if (aca->addr == INADDR_NONE) { + /* XXX: This will be logged as parse error. */ return(-1); } @@ -569,81 +831,23 @@ int acl_addr(char *aspec, struct access_control_addr *aca) /********************************************************************* * - * Function : match_portlist + * Function : connect_port_is_forbidden * - * Description : Check if a given number is covered by a comma - * separated list of numbers and ranges (a,b-c,d,..) + * Description : Check to see if CONNECT requests to the destination + * port of this request are forbidden. The check is + * independend of the actual request method. * * Parameters : - * 1 : portlist = String with list - * 2 : port = port to check + * 1 : csp = Current client state (buffers, headers, etc...) * - * Returns : 0 => no match - * 1 => match + * Returns : True if yes, false otherwise. * *********************************************************************/ -int match_portlist(const char *portlist, int port) +int connect_port_is_forbidden(const struct client_state *csp) { - char *min, *max, *next, *portlist_copy; - - min = next = portlist_copy = strdup(portlist); - - /* - * Zero-terminate first item and remember offset for next - */ - if (NULL != (next = strchr(portlist_copy, (int) ','))) - { - *next++ = '\0'; - } - - /* - * Loop through all items, checking for match - */ - while(min) - { - if (NULL == (max = strchr(min, (int) '-'))) - { - /* - * No dash, check for equality - */ - if (port == atoi(min)) - { - free(portlist_copy); - return(1); - } - } - else - { - /* - * This is a range, so check if between min and max, - * or, if max was omitted, between min and 65K - */ - *max++ = '\0'; - if(port >= atoi(min) && port <= (atoi(max) ? atoi(max) : 65535)) - { - free(portlist_copy); - return(1); - } - - } - - /* - * Jump to next item - */ - min = next; - - /* - * Zero-terminate next item and remember offset for n+1 - */ - if ((NULL != next) && (NULL != (next = strchr(next, (int) ',')))) - { - *next++ = '\0'; - } - } - - free(portlist_copy); - return 0; - + return ((csp->action->flags & ACTION_LIMIT_CONNECT) && + !match_portlist(csp->action->string[ACTION_STRING_LIMIT_CONNECT], + csp->http->port)); } @@ -661,10 +865,8 @@ int match_portlist(const char *portlist, int port) *********************************************************************/ struct http_response *block_url(struct client_state *csp) { -#ifdef FEATURE_IMAGE_BLOCKING - char *p; -#endif /* def FEATURE_IMAGE_BLOCKING */ struct http_response *rsp; + const char *new_content_type = NULL; /* * If it's not blocked, don't block it ;-) @@ -673,7 +875,10 @@ struct http_response *block_url(struct client_state *csp) { return NULL; } - + if (csp->action->flags & ACTION_REDIRECT) + { + log_error(LOG_LEVEL_ERROR, "redirect{} overruled by block."); + } /* * Else, prepare a response */ @@ -690,14 +895,25 @@ struct http_response *block_url(struct client_state *csp) if (((csp->action->flags & ACTION_IMAGE_BLOCKER) != 0) && is_imageurl(csp)) { + char *p; /* determine HOW images should be blocked */ p = csp->action->string[ACTION_STRING_IMAGE_BLOCKER]; + if(csp->action->flags & ACTION_HANDLE_AS_EMPTY_DOCUMENT) + { + log_error(LOG_LEVEL_ERROR, "handle-as-empty-document overruled by handle-as-image."); + } #if 1 /* Two alternative strategies, use this one for now: */ /* and handle accordingly: */ if ((p == NULL) || (0 == strcmpic(p, "pattern"))) { + rsp->status = strdup("403 Request blocked by Privoxy"); + if (rsp->status == NULL) + { + free_http_response(rsp); + return cgi_error_memory(); + } rsp->body = bindup(image_pattern_data, image_pattern_length); if (rsp->body == NULL) { @@ -715,6 +931,12 @@ struct http_response *block_url(struct client_state *csp) else if (0 == strcmpic(p, "blank")) { + rsp->status = strdup("403 Request blocked by Privoxy"); + if (rsp->status == NULL) + { + free_http_response(rsp); + return cgi_error_memory(); + } rsp->body = bindup(image_blank_data, image_blank_length); if (rsp->body == NULL) { @@ -771,6 +993,33 @@ struct http_response *block_url(struct client_state *csp) } #endif /* Preceeding code is disabled for now */ } + else if(csp->action->flags & ACTION_HANDLE_AS_EMPTY_DOCUMENT) + { + /* + * Send empty document. + */ + new_content_type = csp->action->string[ACTION_STRING_CONTENT_TYPE]; + + freez(rsp->body); + rsp->body = strdup(" "); + rsp->content_length = 1; + + rsp->status = strdup("403 Request blocked by Privoxy"); + if (rsp->status == NULL) + { + free_http_response(rsp); + return cgi_error_memory(); + } + if (new_content_type != 0) + { + log_error(LOG_LEVEL_HEADER, "Overwriting Content-Type with %s", new_content_type); + if (enlist_unique_header(rsp->headers, "Content-Type", new_content_type)) + { + free_http_response(rsp); + return cgi_error_memory(); + } + } + } else #endif /* def FEATURE_IMAGE_BLOCKING */ @@ -780,6 +1029,7 @@ struct http_response *block_url(struct client_state *csp) { jb_err err; struct map * exports; + char *p; /* * Workaround for stupid Netscape bug which prevents @@ -797,7 +1047,7 @@ struct http_response *block_url(struct client_state *csp) } else { - rsp->status = strdup("404 Request for blocked URL"); + rsp->status = strdup("403 Request for blocked URL"); } if (rsp->status == NULL) @@ -815,13 +1065,38 @@ struct http_response *block_url(struct client_state *csp) #ifdef FEATURE_FORCE_LOAD err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1); -#else /* ifndef FEATURE_FORCE_LOAD */ - err = map_block_killer(exports, "force-support"); + /* + * Export the force conditional block killer if + * + * - Privoxy was compiled without FEATURE_FORCE_LOAD, or + * - Privoxy is configured to enforce blocks, or + * - it's a CONNECT request and enforcing wouldn't work anyway. + */ + if ((csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS) + || (0 == strcmpic(csp->http->gpc, "connect"))) #endif /* ndef FEATURE_FORCE_LOAD */ + { + err = map_block_killer(exports, "force-support"); + } + if (!err) err = map(exports, "protocol", 1, csp->http->ssl ? "https://" : "http://", 1); if (!err) err = map(exports, "hostport", 1, html_encode(csp->http->hostport), 0); if (!err) err = map(exports, "path", 1, html_encode(csp->http->path), 0); - + if (!err) err = map(exports, "path-ue", 1, url_encode(csp->http->path), 0); + if (!err) + { + const char *block_reason; + if (csp->action->string[ACTION_STRING_BLOCK] != NULL) + { + block_reason = csp->action->string[ACTION_STRING_BLOCK]; + } + else + { + assert(connect_port_is_forbidden(csp)); + block_reason = "Forbidden CONNECT port."; + } + err = map(exports, "block-reason", 1, html_encode(block_reason), 0); + } if (err) { free_map(exports); @@ -836,8 +1111,9 @@ struct http_response *block_url(struct client_state *csp) return cgi_error_memory(); } } + rsp->reason = RSP_REASON_BLOCKED; - return finish_http_response(rsp); + return finish_http_response(csp, rsp); } @@ -848,7 +1124,7 @@ struct http_response *block_url(struct client_state *csp) * Function : trust_url FIXME: I should be called distrust_url * * Description : Calls is_untrusted_url to determine if the URL is trusted - * and if not, returns a HTTP 304 response with a reject message. + * and if not, returns a HTTP 403 response with a reject message. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -882,17 +1158,19 @@ struct http_response *trust_url(struct client_state *csp) return cgi_error_memory(); } + rsp->status = strdup("403 Request blocked by Privoxy"); exports = default_exports(csp, NULL); - if (exports == NULL) + if (exports == NULL || rsp->status == NULL) { free_http_response(rsp); return cgi_error_memory(); } /* - * Export the host, port, and referrer information + * Export the protocol, host, port, and referrer information */ err = map(exports, "hostport", 1, csp->http->hostport, 1); + if (!err) err = map(exports, "protocol", 1, csp->http->ssl ? "https://" : "http://", 1); if (!err) err = map(exports, "path", 1, csp->http->path, 1); if (NULL != (p = get_header_value(csp->headers, "Referer:"))) @@ -901,7 +1179,7 @@ struct http_response *trust_url(struct client_state *csp) } else { - if (!err) err = map(exports, "referrer", 1, "unknown", 1); + if (!err) err = map(exports, "referrer", 1, "none set", 1); } if (err) @@ -917,7 +1195,7 @@ struct http_response *trust_url(struct client_state *csp) p = strdup(""); for (tl = csp->config->trust_list; (t = *tl) != NULL ; tl++) { - sprintf(buf, "
  • %s
  • \n", t->spec); + snprintf(buf, sizeof(buf), "
  • %s
  • \n", t->spec); string_append(&p, buf); } err = map(exports, "trusted-referrers", 1, p, 0); @@ -939,7 +1217,7 @@ struct http_response *trust_url(struct client_state *csp) p = strdup(""); for (l = csp->config->trust_info->first; l ; l = l->next) { - sprintf(buf, "
  • %s
    \n",l->str, l->str); + snprintf(buf, sizeof(buf), "
  • %s
    \n", l->str, l->str); string_append(&p, buf); } err = map(exports, "trust-info", 1, p, 0); @@ -957,10 +1235,22 @@ struct http_response *trust_url(struct client_state *csp) } /* - * Export the force prefix or the force conditional block killer + * Export the force conditional block killer if + * + * - Privoxy was compiled without FEATURE_FORCE_LOAD, or + * - Privoxy is configured to enforce blocks, or + * - it's a CONNECT request and enforcing wouldn't work anyway. */ #ifdef FEATURE_FORCE_LOAD - err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1); + if ((csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS) + || (0 == strcmpic(csp->http->gpc, "connect"))) + { + err = map_block_killer(exports, "force-support"); + } + else + { + err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1); + } #else /* ifndef FEATURE_FORCE_LOAD */ err = map_block_killer(exports, "force-support"); #endif /* ndef FEATURE_FORCE_LOAD */ @@ -981,181 +1271,464 @@ struct http_response *trust_url(struct client_state *csp) free_http_response(rsp); return cgi_error_memory(); } + rsp->reason = RSP_REASON_UNTRUSTED; - return finish_http_response(rsp); + return finish_http_response(csp, rsp); } #endif /* def FEATURE_TRUST */ -#ifdef FEATURE_FAST_REDIRECTS /********************************************************************* * - * Function : redirect_url + * Function : compile_dynamic_pcrs_job_list * - * Description : Checks for redirection URLs and returns a HTTP redirect - * to the destination URL, if necessary + * Description : Compiles a dynamic pcrs job list (one with variables + * resolved at request time) * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) + * 2 : b = The filter list to compile * - * Returns : NULL if URL was clean, HTTP redirect otherwise. + * Returns : NULL in case of errors, otherwise the + * pcrs job list. * *********************************************************************/ -struct http_response *redirect_url(struct client_state *csp) +pcrs_job *compile_dynamic_pcrs_job_list(const struct client_state *csp, const struct re_filterfile_spec *b) { - char *p, *q; - struct http_response *rsp; - - p = q = csp->http->path; - log_error(LOG_LEVEL_REDIRECTS, "checking path for redirects: %s", p); + struct list_entry *pattern; + pcrs_job *job_list = NULL; + pcrs_job *dummy = NULL; + pcrs_job *lastjob = NULL; + int error = 0; - /* - * find the last URL encoded in the request - */ - while ((p = strstr(p, "http://")) != NULL) + const struct pcrs_variable variables[] = { - q = p++; - } - - /* - * if there was any, generate and return a HTTP redirect - */ - if (q != csp->http->path) + {"url", csp->http->url, 1}, + {"path", csp->http->path, 1}, + {"host", csp->http->host, 1}, + {"origin", csp->ip_addr_str, 1}, + {NULL, NULL, 1} + }; + + for (pattern = b->patterns->first; pattern != NULL; pattern = pattern->next) { - log_error(LOG_LEVEL_REDIRECTS, "redirecting to: %s", q); + assert(pattern->str != NULL); - if (NULL == (rsp = alloc_http_response())) + dummy = pcrs_compile_dynamic_command(pattern->str, variables, &error); + if (NULL == dummy) { - return cgi_error_memory(); + assert(error < 0); + log_error(LOG_LEVEL_ERROR, + "Adding filter job \'%s\' to dynamic filter %s failed: %s", + pattern->str, b->name, pcrs_strerror(error)); + continue; } - - if ( enlist_unique_header(rsp->headers, "Location", q) - || (NULL == (rsp->status = strdup("302 Local Redirect from Privoxy"))) ) + else { - free_http_response(rsp); - return cgi_error_memory(); + if (error == PCRS_WARN_TRUNCATION) + { + log_error(LOG_LEVEL_ERROR, + "At least one of the variables in \'%s\' had to " + "be truncated before compilation", pattern->str); + } + if (job_list == NULL) + { + job_list = dummy; + } + else + { + lastjob->next = dummy; + } + lastjob = dummy; } + } + + return job_list; +} + + +/********************************************************************* + * + * Function : rewrite_url + * + * Description : Rewrites a URL with a single pcrs command + * and returns the result if it differs from the + * original and isn't obviously invalid. + * + * Parameters : + * 1 : old_url = URL to rewrite. + * 2 : pcrs_command = pcrs command formatted as string (s@foo@bar@) + * + * + * Returns : NULL if the pcrs_command didn't change the url, or + * the result of the modification. + * + *********************************************************************/ +char *rewrite_url(char *old_url, const char *pcrs_command) +{ + char *new_url = NULL; + int hits; - return finish_http_response(rsp); + assert(old_url); + assert(pcrs_command); + + new_url = pcrs_execute_single_command(old_url, pcrs_command, &hits); + + if (hits == 0) + { + log_error(LOG_LEVEL_REDIRECTS, + "pcrs command \"%s\" didn't change \"%s\".", + pcrs_command, old_url); + freez(new_url); + } + else if (hits < 0) + { + log_error(LOG_LEVEL_REDIRECTS, + "executing pcrs command \"%s\" to rewrite %s failed: %s", + pcrs_command, old_url, pcrs_strerror(hits)); + freez(new_url); + } + else if (strncmpic(new_url, "http://", 7) && strncmpic(new_url, "https://", 8)) + { + log_error(LOG_LEVEL_ERROR, + "pcrs command \"%s\" changed \"%s\" to \"%s\" (%u hi%s), " + "but the result doesn't look like a valid URL and will be ignored.", + pcrs_command, old_url, new_url, hits, (hits == 1) ? "t" : "ts"); + freez(new_url); } else { - return NULL; + log_error(LOG_LEVEL_REDIRECTS, + "pcrs command \"%s\" changed \"%s\" to \"%s\" (%u hi%s).", + pcrs_command, old_url, new_url, hits, (hits == 1) ? "t" : "ts"); } + return new_url; + } -#endif /* def FEATURE_FAST_REDIRECTS */ -#ifdef FEATURE_IMAGE_BLOCKING +#ifdef FEATURE_FAST_REDIRECTS /********************************************************************* * - * Function : is_imageurl + * Function : get_last_url * - * Description : Given a URL, decide whether it is an image or not, - * using either the info from a previous +image action - * or, #ifdef FEATURE_IMAGE_DETECT_MSIE, the info from - * the browser's accept header. + * Description : Search for the last URL inside a string. + * If the string already is a URL, it will + * be the first URL found. * * Parameters : - * 1 : csp = Current client state (buffers, headers, etc...) + * 1 : subject = the string to check + * 2 : redirect_mode = +fast-redirect{} mode * - * Returns : True (nonzero) if URL is an image, false (0) - * otherwise + * Returns : NULL if no URL was found, or + * the last URL found. * *********************************************************************/ -int is_imageurl(struct client_state *csp) +char *get_last_url(char *subject, const char *redirect_mode) { -#ifdef FEATURE_IMAGE_DETECT_MSIE + char *new_url = NULL; char *tmp; - tmp = get_header_value(csp->headers, "User-Agent:"); - if (tmp && strstr(tmp, "MSIE")) + assert(subject); + assert(redirect_mode); + + subject = strdup(subject); + if (subject == NULL) { - tmp = get_header_value(csp->headers, "Accept:"); - if (tmp && strstr(tmp, "image/gif")) + log_error(LOG_LEVEL_ERROR, "Out of memory while searching for redirects."); + return NULL; + } + + if (0 == strcmpic(redirect_mode, "check-decoded-url")) + { + log_error(LOG_LEVEL_REDIRECTS, "Decoding \"%s\" if necessary.", subject); + new_url = url_decode(subject); + if (new_url != NULL) { - /* Client will accept HTML. If this seems counterintuitive, - * blame Microsoft. - */ - return(0); + freez(subject); + subject = new_url; } else { - return(1); + log_error(LOG_LEVEL_ERROR, "Unable to decode \"%s\".", subject); } } -#endif /* def FEATURE_IMAGE_DETECT_MSIE */ - return ((csp->action->flags & ACTION_IMAGE) != 0); + log_error(LOG_LEVEL_REDIRECTS, "Checking \"%s\" for redirects.", subject); + + /* + * Find the last URL encoded in the request + */ + tmp = subject; + while ((tmp = strstr(tmp, "http://")) != NULL) + { + new_url = tmp++; + } + tmp = (new_url != NULL) ? new_url : subject; + while ((tmp = strstr(tmp, "https://")) != NULL) + { + new_url = tmp++; + } + + if ((new_url != NULL) + && ( (new_url != subject) + || (0 == strncmpic(subject, "http://", 7)) + || (0 == strncmpic(subject, "https://", 8)) + )) + { + /* + * Return new URL if we found a redirect + * or if the subject already was a URL. + * + * The second case makes sure that we can + * chain get_last_url after another redirection check + * (like rewrite_url) without losing earlier redirects. + */ + new_url = strdup(new_url); + freez(subject); + return new_url; + } + + freez(subject); + return NULL; } -#endif /* def FEATURE_IMAGE_BLOCKING */ +#endif /* def FEATURE_FAST_REDIRECTS */ -#ifdef FEATURE_COOKIE_JAR /********************************************************************* * - * Function : is_untrusted_url - * - * Description : Should we "distrust" this URL (and block it)? + * Function : redirect_url * - * Yes if it matches a line in the trustfile, or if the - * referrer matches a line starting with "+" in the - * trustfile. - * No otherwise. + * Description : Checks if Privoxy should answer the request with + * a HTTP redirect and generates the redirect if + * necessary. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) * - * Returns : 0 => trusted, 1 => untrusted + * Returns : NULL if the request can pass, HTTP redirect otherwise. * *********************************************************************/ -int is_untrusted_url(struct client_state *csp) +struct http_response *redirect_url(struct client_state *csp) { - struct file_list *fl; - struct block_spec *b; - struct url_spec **trusted_url; - struct http_request rhttp[1]; - const char * referer; - jb_err err; - + struct http_response *rsp; +#ifdef FEATURE_FAST_REDIRECTS /* - * If we don't have a trustlist, we trust everybody + * XXX: Do we still need FEATURE_FAST_REDIRECTS + * as compile-time option? The user can easily disable + * it in his action file. */ - if (((fl = csp->tlist) == NULL) || ((b = fl->f) == NULL)) + char * redirect_mode; +#endif /* def FEATURE_FAST_REDIRECTS */ + char *old_url = NULL; + char *new_url = NULL; + char *redirection_string; + + if ((csp->action->flags & ACTION_REDIRECT)) { - return 0; - } + redirection_string = csp->action->string[ACTION_STRING_REDIRECT]; - memset(rhttp, '\0', sizeof(*rhttp)); + /* + * If the redirection string begins with 's', + * assume it's a pcrs command, otherwise treat it as + * properly formatted URL and use it for the redirection + * directly. + * + * According to RFC 2616 section 14.30 the URL + * has to be absolute and if the user tries: + * +redirect{shit/this/will/be/parsed/as/pcrs_command.html} + * she would get undefined results anyway. + * + */ - /* - * Do we trust the request URL itself? - */ - for (b = b->next; b ; b = b->next) - { - if (url_match(b->url, csp->http)) + if (*redirection_string == 's') { - return b->reject; + old_url = csp->http->url; + new_url = rewrite_url(old_url, redirection_string); + } + else + { + log_error(LOG_LEVEL_REDIRECTS, + "No pcrs command recognized, assuming that \"%s\" is already properly formatted.", + redirection_string); + new_url = strdup(redirection_string); } } - if (NULL == (referer = get_header_value(csp->headers, "Referer:"))) +#ifdef FEATURE_FAST_REDIRECTS + if ((csp->action->flags & ACTION_FAST_REDIRECTS)) { - /* no referrer was supplied */ - return 1; + redirect_mode = csp->action->string[ACTION_STRING_FAST_REDIRECTS]; + + /* + * If it exists, use the previously rewritten URL as input + * otherwise just use the old path. + */ + old_url = (new_url != NULL) ? new_url : strdup(csp->http->path); + new_url = get_last_url(old_url, redirect_mode); + freez(old_url); } /* - * If not, do we maybe trust its referrer? + * Disable redirect checkers, so that they + * will be only run more than once if the user + * also enables them through tags. + * + * From a performance point of view + * it doesn't matter, but the duplicated + * log messages are annoying. */ + csp->action->flags &= ~ACTION_FAST_REDIRECTS; +#endif /* def FEATURE_FAST_REDIRECTS */ + csp->action->flags &= ~ACTION_REDIRECT; + + /* Did any redirect action trigger? */ + if (new_url) + { + if (0 == strcmpic(new_url, csp->http->url)) + { + log_error(LOG_LEVEL_ERROR, + "New URL \"%s\" and old URL \"%s\" are the same. Redirection loop prevented.", + csp->http->url, new_url); + freez(new_url); + } + else + { + log_error(LOG_LEVEL_REDIRECTS, "New URL is: %s", new_url); + + if (NULL == (rsp = alloc_http_response())) + { + freez(new_url); + return cgi_error_memory(); + } + + if ( enlist_unique_header(rsp->headers, "Location", new_url) + || (NULL == (rsp->status = strdup("302 Local Redirect from Privoxy"))) ) + { + freez(new_url); + free_http_response(rsp); + return cgi_error_memory(); + } + rsp->reason = RSP_REASON_REDIRECTED; + freez(new_url); + + return finish_http_response(csp, rsp); + } + } + + /* Only reached if no redirect is required */ + return NULL; + +} + + +#ifdef FEATURE_IMAGE_BLOCKING +/********************************************************************* + * + * Function : is_imageurl + * + * Description : Given a URL, decide whether it is an image or not, + * using either the info from a previous +image action + * or, #ifdef FEATURE_IMAGE_DETECT_MSIE, and the browser + * is MSIE and not on a Mac, tell from the browser's accept + * header. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : True (nonzero) if URL is an image, false (0) + * otherwise + * + *********************************************************************/ +int is_imageurl(const struct client_state *csp) +{ +#ifdef FEATURE_IMAGE_DETECT_MSIE + char *tmp; + + tmp = get_header_value(csp->headers, "User-Agent:"); + if (tmp && strstr(tmp, "MSIE") && !strstr(tmp, "Mac_")) + { + tmp = get_header_value(csp->headers, "Accept:"); + if (tmp && strstr(tmp, "image/gif")) + { + /* Client will accept HTML. If this seems counterintuitive, + * blame Microsoft. + */ + return(0); + } + else + { + return(1); + } + } +#endif /* def FEATURE_IMAGE_DETECT_MSIE */ + + return ((csp->action->flags & ACTION_IMAGE) != 0); + +} +#endif /* def FEATURE_IMAGE_BLOCKING */ + + +#ifdef FEATURE_TRUST +/********************************************************************* + * + * Function : is_untrusted_url + * + * Description : Should we "distrust" this URL (and block it)? + * + * Yes if it matches a line in the trustfile, or if the + * referrer matches a line starting with "+" in the + * trustfile. + * No otherwise. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : 0 => trusted, 1 => untrusted + * + *********************************************************************/ +int is_untrusted_url(const struct client_state *csp) +{ + struct file_list *fl; + struct block_spec *b; + struct url_spec **trusted_url; + struct http_request rhttp[1]; + const char * referer; + jb_err err; + + /* + * If we don't have a trustlist, we trust everybody + */ + if (((fl = csp->tlist) == NULL) || ((b = fl->f) == NULL)) + { + return 0; + } + + memset(rhttp, '\0', sizeof(*rhttp)); - /* - * Parse the URL from the referrer + * Do we trust the request URL itself? */ + for (b = b->next; b ; b = b->next) + { + if (url_match(b->url, csp->http)) + { + return b->reject; + } + } + + if (NULL == (referer = get_header_value(csp->headers, "Referer:"))) + { + /* no referrer was supplied */ + return 1; + } + + /* + * If not, do we maybe trust its referrer? + */ err = parse_http_url(referer, rhttp, csp); if (err) { @@ -1168,7 +1741,7 @@ int is_untrusted_url(struct client_state *csp) { /* if the URL's referrer is from a trusted referrer, then * add the target spec to the trustfile as an unblocked - * domain and return NULL (which means it's OK). + * domain and return 0 (which means it's OK). */ FILE *fp; @@ -1199,10 +1772,20 @@ int is_untrusted_url(struct client_state *csp) string_join(&new_entry, path); } + /* + * Give a reason for generating this entry. + */ + string_append(&new_entry, " # Trusted referrer was: "); + string_append(&new_entry, referer); + if (new_entry != NULL) { - fprintf(fp, "%s\n", new_entry); - free(new_entry); + if (-1 == fprintf(fp, "%s\n", new_entry)) + { + log_error(LOG_LEVEL_ERROR, "Failed to append \'%s\' to trustfile \'%s\': %E", + new_entry, csp->config->trustfile); + } + freez(new_entry); } else { @@ -1212,23 +1795,27 @@ int is_untrusted_url(struct client_state *csp) fclose(fp); } + else + { + log_error(LOG_LEVEL_ERROR, "Failed to append new entry for \'%s\' to trustfile \'%s\': %E", + csp->http->hostport, csp->config->trustfile); + } return 0; } } + return 1; } -#endif /* def FEATURE_COOKIE_JAR */ +#endif /* def FEATURE_TRUST */ /********************************************************************* * * Function : pcrs_filter_response * - * Description : Ecexute all text substitutions from all applying - * +filter actions on the text buffer that's been accumulated - * in csp->iob->buf. If this changes the contents, set - * csp->content_length to the modified size and raise the - * CSP_FLAG_MODIFIED flag. + * Description : Execute all text substitutions from all applying + * +filter actions on the text buffer that's been + * accumulated in csp->iob->buf. * * Parameters : * 1 : csp = Current client state (buffers, headers, etc...) @@ -1237,18 +1824,21 @@ int is_untrusted_url(struct client_state *csp) * or NULL if there were no hits or something went wrong * *********************************************************************/ -char *pcrs_filter_response(struct client_state *csp) +static char *pcrs_filter_response(struct client_state *csp) { int hits=0; - size_t size; + size_t size, prev_size; - char *old = csp->iob->cur, *new = NULL; + char *old = NULL; + char *new = NULL; pcrs_job *job; struct file_list *fl; struct re_filterfile_spec *b; struct list_entry *filtername; + int i, found_filters = 0; + /* * Sanity first */ @@ -1256,29 +1846,49 @@ char *pcrs_filter_response(struct client_state *csp) { return(NULL); } - size = csp->iob->eod - csp->iob->cur; - - if ( ( NULL == (fl = csp->rlist) ) || ( NULL == fl->f) ) - { - log_error(LOG_LEVEL_ERROR, "Unable to get current state of regexp filtering."); - return(NULL); - } /* - * If the body has a "chunked" transfer-encoding, - * get rid of it first, adjusting size and iob->eod + * Need to check the set of re_filterfiles... */ - if (csp->flags & CSP_FLAG_CHUNKED) + for (i = 0; i < MAX_AF_FILES; i++) { - log_error(LOG_LEVEL_RE_FILTER, "Need to de-chunk first"); - if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size))) + fl = csp->rlist[i]; + if (NULL != fl) { - return(NULL); + if (NULL != fl->f) + { + found_filters = 1; + break; + } } - csp->iob->eod = csp->iob->cur + size; - csp->flags |= CSP_FLAG_MODIFIED; } + if (0 == found_filters) + { + log_error(LOG_LEVEL_ERROR, "Inconsistent configuration: " + "content filtering enabled, but no content filters available."); + return(NULL); + } + + size = (size_t)(csp->iob->eod - csp->iob->cur); + old = csp->iob->cur; + + 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 it's pcrs_joblist on the @@ -1286,35 +1896,86 @@ char *pcrs_filter_response(struct client_state *csp) */ for (b = fl->f; b; b = b->next) { + if (b->type != FT_CONTENT_FILTER) + { + /* Skip header filters */ + continue; + } + for (filtername = csp->action->multi[ACTION_MULTI_FILTER]->first; filtername ; filtername = filtername->next) { if (strcmp(b->name, filtername->str) == 0) { - int current_hits = 0; + int current_hits = 0; /* Number of hits caused by this filter */ + int job_number = 0; /* Which job we're currently executing */ + int job_hits = 0; /* How many hits the current job caused */ + pcrs_job *joblist = b->joblist; + + if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b); - if ( NULL == b->joblist ) + if (NULL == joblist) { log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name); - return(NULL); + continue; } - log_error(LOG_LEVEL_RE_FILTER, "re_filtering %s%s (size %d) with filter %s...", - csp->http->hostport, csp->http->path, size, b->name); - + prev_size = size; /* Apply all jobs from the joblist */ - for (job = b->joblist; NULL != job; job = job->next) + for (job = joblist; NULL != job; job = job->next) { - current_hits += pcrs_execute(job, old, size, &new, &size); - if (old != csp->iob->cur) free(old); - old=new; + job_number++; + job_hits = pcrs_execute(job, old, size, &new, &size); + + if (job_hits >= 0) + { + /* + * That went well. Continue filtering + * and use the result of this job as + * input for the next one. + */ + current_hits += job_hits; + if (old != csp->iob->cur) + { + freez(old); + } + old = new; + } + else + { + /* + * This job caused an unexpected error. Inform the user + * and skip the rest of the jobs in this filter. We could + * continue with the next job, but usually the jobs + * depend on each other or are similar enough to + * fail for the same reason. + * + * At the moment our pcrs expects the error codes of pcre 3.4, + * but newer pcre versions can return additional error codes. + * As a result pcrs_strerror()'s error message might be + * "Unknown error ...", therefore we print the numerical value + * as well. + * + * XXX: Is this important enough for LOG_LEVEL_ERROR or + * should we use LOG_LEVEL_RE_FILTER instead? + */ + log_error(LOG_LEVEL_ERROR, "Skipped filter \'%s\' after job number %u: %s (%d)", + b->name, job_number, pcrs_strerror(job_hits), job_hits); + break; + } } - log_error(LOG_LEVEL_RE_FILTER, " ...produced %d hits (new size %d).", current_hits, size); + if (b->dynamic) pcrs_free_joblist(joblist); + + log_error(LOG_LEVEL_RE_FILTER, + "filtering %s%s (size %d) with \'%s\' produced %d hits (new size %d).", + csp->http->hostport, csp->http->path, prev_size, b->name, current_hits, size); + hits += current_hits; } } } + } /* * If there were no hits, destroy our copy and let @@ -1322,7 +1983,7 @@ char *pcrs_filter_response(struct client_state *csp) */ if (!hits) { - free(new); + freez(new); return(NULL); } @@ -1350,26 +2011,13 @@ char *pcrs_filter_response(struct client_state *csp) * or NULL in case something went wrong. * *********************************************************************/ -char *gif_deanimate_response(struct client_state *csp) +static char *gif_deanimate_response(struct client_state *csp) { struct binbuffer *in, *out; char *p; - size_t size = csp->iob->eod - csp->iob->cur; + size_t size; - /* - * If the body has a "chunked" transfer-encoding, - * get rid of it first, adjusting size and iob->eod - */ - if (csp->flags & CSP_FLAG_CHUNKED) - { - log_error(LOG_LEVEL_DEANIMATE, "Need to de-chunk first"); - if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size))) - { - return(NULL); - } - csp->iob->eod = csp->iob->cur + size; - csp->flags |= CSP_FLAG_MODIFIED; - } + size = (size_t)(csp->iob->eod - csp->iob->cur); if ( (NULL == (in = (struct binbuffer *)zalloc(sizeof *in ))) || (NULL == (out = (struct binbuffer *)zalloc(sizeof *out))) ) @@ -1384,7 +2032,7 @@ char *gif_deanimate_response(struct client_state *csp) if (gif_deanimate(in, out, strncmp("last", csp->action->string[ACTION_STRING_DEANIMATE], 4))) { log_error(LOG_LEVEL_DEANIMATE, "failed! (gif parsing)"); - free(in); + freez(in); buf_free(out); return(NULL); } @@ -1401,14 +2049,157 @@ char *gif_deanimate_response(struct client_state *csp) csp->content_length = out->offset; csp->flags |= CSP_FLAG_MODIFIED; p = out->buffer; - free(in); - free(out); + freez(in); + freez(out); return(p); } } +/********************************************************************* + * + * Function : jpeg_inspect_response + * + * Description : + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : a pointer to the (newly allocated) modified buffer + * or NULL in case something went wrong. + * + *********************************************************************/ +static char *jpeg_inspect_response(struct client_state *csp) +{ + struct binbuffer *in = NULL; + struct binbuffer *out = NULL; + char *p = NULL; + size_t size; + + size = (size_t)(csp->iob->eod - csp->iob->cur); + + if (NULL == (in = (struct binbuffer *)zalloc(sizeof *in ))) + { + log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg no mem 1)"); + return NULL; + } + + if (NULL == (out = (struct binbuffer *)zalloc(sizeof *out))) + { + log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg no mem 2)"); + return NULL; + } + + in->buffer = csp->iob->cur; + in->size = size; + + /* + * Calling jpeg_inspect has the side-effect of creating and + * modifying the image buffer of "out" directly. + */ + if (jpeg_inspect(in, out)) + { + log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg parsing)"); + freez(in); + buf_free(out); + return(NULL); + + } + else + { + csp->content_length = out->offset; + csp->flags |= CSP_FLAG_MODIFIED; + p = out->buffer; + freez(in); + freez(out); + return(p); + } + +} + + +/********************************************************************* + * + * Function : get_filter_function + * + * Description : Decides which content filter function has + * to be applied (if any). + * + * XXX: Doesn't handle filter_popups() + * because of the different prototype. Probably + * we should ditch filter_popups() anyway, it's + * even less reliable than popup blocking based + * on pcrs filters. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : The content filter function to run, or + * NULL if no content filter is active + * + *********************************************************************/ +filter_function_ptr get_filter_function(struct client_state *csp) +{ + filter_function_ptr filter_function = NULL; + + /* + * Are we enabling text mode by force? + */ + if (csp->action->flags & ACTION_FORCE_TEXT_MODE) + { + /* + * Do we really have to? + */ + if (csp->content_type & CT_TEXT) + { + log_error(LOG_LEVEL_HEADER, "Text mode is already enabled."); + } + else + { + csp->content_type |= CT_TEXT; + log_error(LOG_LEVEL_HEADER, "Text mode enabled by force. Take cover!"); + } + } + + if (!(csp->content_type & CT_DECLARED)) + { + /* + * The server didn't bother to declare a MIME-Type. + * Assume it's text that can be filtered. + * + * This also regulary happens with 304 responses, + * therefore logging anything here would cause + * too much noise. + */ + csp->content_type |= CT_TEXT; + } + + /* + * Choose the applying filter function based on + * the content type and action settings. + */ + if ((csp->content_type & CT_TEXT) && + (csp->rlist != NULL) && + (!list_is_empty(csp->action->multi[ACTION_MULTI_FILTER]))) + { + filter_function = pcrs_filter_response; + } + else if ((csp->content_type & CT_GIF) && + (csp->action->flags & ACTION_DEANIMATE)) + { + filter_function = gif_deanimate_response; + } + else if ((csp->content_type & CT_JPEG) && + (csp->action->flags & ACTION_JPEG_INSPECT)) + { + filter_function = jpeg_inspect_response; + } + + return filter_function; +} + + /********************************************************************* * * Function : remove_chunked_transfer_coding @@ -1418,14 +2209,15 @@ char *gif_deanimate_response(struct client_state *csp) * * Parameters : * 1 : buffer = Pointer to the text buffer - * 2 : size = Number of bytes to be processed + * 2 : size = In: Number of bytes to be processed, + * Out: Number of bytes after de-chunking. + * (undefined in case of errors) * - * Returns : The new size, i.e. the number of bytes from buffer which - * are occupied by the stripped body, or 0 in case something - * went wrong + * Returns : JB_ERR_OK for success, + * JB_ERR_PARSE otherwise * *********************************************************************/ -int remove_chunked_transfer_coding(char *buffer, const size_t size) +static jb_err remove_chunked_transfer_coding(char *buffer, size_t *size) { size_t newsize = 0; unsigned int chunksize = 0; @@ -1437,7 +2229,7 @@ int remove_chunked_transfer_coding(char *buffer, const size_t size) if (sscanf(buffer, "%x", &chunksize) != 1) { log_error(LOG_LEVEL_ERROR, "Invalid first chunksize while stripping \"chunked\" transfer coding"); - return(0); + return JB_ERR_PARSE; } while (chunksize > 0) @@ -1445,9 +2237,14 @@ int remove_chunked_transfer_coding(char *buffer, const size_t size) if (NULL == (from_p = strstr(from_p, "\r\n"))) { log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding"); - return(0); + return JB_ERR_PARSE; + } + + if ((newsize += chunksize) >= *size) + { + log_error(LOG_LEVEL_ERROR, "Chunksize exceeds buffer in \"chunked\" transfer coding"); + return JB_ERR_PARSE; } - newsize += chunksize; from_p += 2; memmove(to_p, from_p, (size_t) chunksize); @@ -1456,46 +2253,173 @@ int remove_chunked_transfer_coding(char *buffer, const size_t size) if (sscanf(from_p, "%x", &chunksize) != 1) { - log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding"); - return(0); + log_error(LOG_LEVEL_INFO, "Invalid \"chunked\" transfer encoding detected and ignored."); + break; + } + } + + /* XXX: Should get its own loglevel. */ + log_error(LOG_LEVEL_RE_FILTER, "De-chunking successful. Shrunk from %d to %d", *size, newsize); + + *size = newsize; + + return JB_ERR_OK; + +} + + +/********************************************************************* + * + * Function : prepare_for_filtering + * + * Description : If necessary, de-chunks and decompresses + * the content so it can get filterd. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : JB_ERR_OK for success, + * JB_ERR_PARSE otherwise + * + *********************************************************************/ +static jb_err prepare_for_filtering(struct client_state *csp) +{ + jb_err err = JB_ERR_OK; + + /* + * If the body has a "chunked" transfer-encoding, + * get rid of it, adjusting size and iob->eod + */ + if (csp->flags & CSP_FLAG_CHUNKED) + { + size_t size = (size_t)(csp->iob->eod - csp->iob->cur); + + log_error(LOG_LEVEL_RE_FILTER, "Need to de-chunk first"); + err = remove_chunked_transfer_coding(csp->iob->cur, &size); + if (JB_ERR_OK == err) + { + csp->iob->eod = csp->iob->cur + size; + csp->flags |= CSP_FLAG_MODIFIED; + } + else + { + return JB_ERR_PARSE; } } - /* FIXME: Should this get its own loglevel? */ - log_error(LOG_LEVEL_RE_FILTER, "De-chunking successful. Shrunk from %d to %d\n", size, newsize); - return(newsize); +#ifdef FEATURE_ZLIB + /* + * If the body has a supported transfer-encoding, + * decompress it, adjusting size and iob->eod. + */ + if (csp->content_type & (CT_GZIP|CT_DEFLATE)) + { + if (0 == csp->iob->eod - csp->iob->cur) + { + /* Nothing left after de-chunking. */ + return JB_ERR_OK; + } + err = decompress_iob(csp); + + if (JB_ERR_OK == err) + { + csp->flags |= CSP_FLAG_MODIFIED; + csp->content_type &= ~CT_TABOO; + } + else + { + /* + * Unset CT_GZIP and CT_DEFLATE to remember not + * to modify the Content-Encoding header later. + */ + csp->content_type &= ~CT_GZIP; + csp->content_type &= ~CT_DEFLATE; + } + } +#endif + + return err; } /********************************************************************* * - * Function : url_actions + * Function : execute_content_filter + * + * Description : Executes a given content filter. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * 2 : content_filter = The filter function to execute + * + * Returns : Pointer to the modified buffer, or + * NULL if filtering failed or wasn't necessary. + * + *********************************************************************/ +char *execute_content_filter(struct client_state *csp, filter_function_ptr content_filter) +{ + if (0 == csp->iob->eod - csp->iob->cur) + { + /* + * No content (probably status code 301, 302 ...), + * no filtering necessary. + */ + return NULL; + } + + if (JB_ERR_OK != prepare_for_filtering(csp)) + { + /* + * failed to de-chunk or decompress. + */ + return NULL; + } + + if (0 == csp->iob->eod - csp->iob->cur) + { + /* + * Clown alarm: chunked and/or compressed nothing delivered. + */ + return NULL; + } + + return ((*content_filter)(csp)); +} + + +/********************************************************************* + * + * Function : get_url_actions * * Description : Gets the actions for this URL. * * Parameters : - * 1 : http = http_request request for blocked URLs - * 2 : csp = Current client state (buffers, headers, etc...) + * 1 : csp = Current client state (buffers, headers, etc...) + * 2 : http = http_request request for blocked URLs * * Returns : N/A * *********************************************************************/ -void url_actions(struct http_request *http, - struct client_state *csp) +void get_url_actions(struct client_state *csp, struct http_request *http) { struct file_list *fl; struct url_actions *b; + int i; init_current_action(csp->action); - if (((fl = csp->actions_list) == NULL) || ((b = fl->f) == NULL)) + for (i = 0; i < MAX_AF_FILES; i++) { - return; - } + if (((fl = csp->actions_list[i]) == NULL) || ((b = fl->f) == NULL)) + { + return; + } - apply_url_actions(csp->action, http, b); + apply_url_actions(csp->action, http, b); + } + return; } @@ -1533,6 +2457,153 @@ void apply_url_actions(struct current_action_spec *action, } +/********************************************************************* + * + * Function : get_forward_override_settings + * + * Description : Returns forward settings as specified with the + * forward-override{} action. forward-override accepts + * forward lines similar to the one used in the + * configuration file, but without the URL pattern. + * + * For example: + * + * forward / . + * + * in the configuration file can be replaced with + * the action section: + * + * {+forward-override{forward .}} + * / + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : Pointer to forwarding structure in case of success. + * Invalid syntax is fatal. + * + *********************************************************************/ +const static struct forward_spec *get_forward_override_settings(struct client_state *csp) +{ + const char *forward_override_line = csp->action->string[ACTION_STRING_FORWARD_OVERRIDE]; + char forward_settings[BUFFER_SIZE]; + char *http_parent = NULL; + /* variable names were chosen for consistency reasons. */ + struct forward_spec *fwd = NULL; + int vec_count; + char *vec[3]; + + assert(csp->action->flags & ACTION_FORWARD_OVERRIDE); + /* Should be enforced by load_one_actions_file() */ + assert(strlen(forward_override_line) < sizeof(forward_settings) - 1); + + /* Create a copy ssplit can modify */ + strlcpy(forward_settings, forward_override_line, sizeof(forward_settings)); + + if (NULL != csp->fwd) + { + /* + * XXX: Currently necessary to prevent memory + * leaks when the show-url-info cgi page is visited. + */ + unload_forward_spec(csp->fwd); + } + + /* + * allocate a new forward node, valid only for + * the lifetime of this request. Save its location + * in csp as well, so sweep() can free it later on. + */ + fwd = csp->fwd = zalloc(sizeof(*fwd)); + if (NULL == fwd) + { + log_error(LOG_LEVEL_FATAL, + "can't allocate memory for forward-override{%s}", forward_override_line); + /* Never get here - LOG_LEVEL_FATAL causes program exit */ + } + + vec_count = ssplit(forward_settings, " \t", vec, SZ(vec), 1, 1); + if ((vec_count == 2) && !strcasecmp(vec[0], "forward")) + { + fwd->type = SOCKS_NONE; + + /* Parse the parent HTTP proxy host:port */ + http_parent = vec[1]; + + } + else if (vec_count == 3) + { + char *socks_proxy = NULL; + + if (!strcasecmp(vec[0], "forward-socks4")) + { + fwd->type = SOCKS_4; + socks_proxy = vec[1]; + } + else if (!strcasecmp(vec[0], "forward-socks4a")) + { + fwd->type = SOCKS_4A; + socks_proxy = vec[1]; + } + else if (!strcasecmp(vec[0], "forward-socks5")) + { + fwd->type = SOCKS_5; + socks_proxy = vec[1]; + } + + if (NULL != socks_proxy) + { + /* Parse the SOCKS proxy host[:port] */ + fwd->gateway_host = strdup(socks_proxy); + + if (NULL != (socks_proxy = strchr(fwd->gateway_host, ':'))) + { + *socks_proxy++ = '\0'; + fwd->gateway_port = strtol(socks_proxy, NULL, 0); + } + + if (fwd->gateway_port <= 0) + { + fwd->gateway_port = 1080; + } + + http_parent = vec[2]; + } + } + + if (NULL == http_parent) + { + log_error(LOG_LEVEL_FATAL, + "Invalid forward-override syntax in: %s", forward_override_line); + /* Never get here - LOG_LEVEL_FATAL causes program exit */ + } + + /* Parse http forwarding settings */ + if (strcmp(http_parent, ".") != 0) + { + fwd->forward_host = strdup(http_parent); + + if (NULL != (http_parent = strchr(fwd->forward_host, ':'))) + { + *http_parent++ = '\0'; + fwd->forward_port = strtol(http_parent, NULL, 0); + } + + if (fwd->forward_port <= 0) + { + fwd->forward_port = 8000; + } + } + + assert (NULL != fwd); + + log_error(LOG_LEVEL_CONNECT, + "Overriding forwarding settings based on \'%s\'", forward_override_line); + + return fwd; +} + + /********************************************************************* * * Function : forward_url @@ -1540,18 +2611,23 @@ void apply_url_actions(struct current_action_spec *action, * Description : Should we forward this to another proxy? * * Parameters : - * 1 : http = http_request request for current URL - * 2 : csp = Current client state (buffers, headers, etc...) + * 1 : csp = Current client state (buffers, headers, etc...) + * 2 : http = http_request request for current URL * * Returns : Pointer to forwarding information. * *********************************************************************/ -const struct forward_spec * forward_url(struct http_request *http, - struct client_state *csp) +const struct forward_spec *forward_url(struct client_state *csp, + const struct http_request *http) { static const struct forward_spec fwd_default[1] = { FORWARD_SPEC_INITIALIZER }; struct forward_spec *fwd = csp->config->forward; + if (csp->action->flags & ACTION_FORWARD_OVERRIDE) + { + return get_forward_override_settings(csp); + } + if (fwd == NULL) { return fwd_default; @@ -1570,6 +2646,96 @@ const struct forward_spec * forward_url(struct http_request *http, } +/********************************************************************* + * + * Function : direct_response + * + * Description : Check if Max-Forwards == 0 for an OPTIONS or TRACE + * request and if so, return a HTTP 501 to the client. + * + * FIXME: I have a stupid name and I should handle the + * requests properly. Still, what we do here is rfc- + * compliant, whereas ignoring or forwarding are not. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : http_response if , NULL if nonmatch or handler fail + * + *********************************************************************/ +struct http_response *direct_response(struct client_state *csp) +{ + struct http_response *rsp; + struct list_entry *p; + + if ((0 == strcmpic(csp->http->gpc, "trace")) + || (0 == strcmpic(csp->http->gpc, "options"))) + { + for (p = csp->headers->first; (p != NULL) ; p = p->next) + { + if (!strncmpic("Max-Forwards:", p->str, 13)) + { + unsigned int max_forwards; + + /* + * If it's a Max-Forwards value of zero, + * we have to intercept the request. + */ + if (1 == sscanf(p->str+12, ": %u", &max_forwards) && max_forwards == 0) + { + /* + * FIXME: We could handle at least TRACE here, + * but that would require a verbatim copy of + * the request which we don't have anymore + */ + log_error(LOG_LEVEL_HEADER, + "Detected header \'%s\' in OPTIONS or TRACE request. Returning 501.", + p->str); + + /* Get mem for response or fail*/ + if (NULL == (rsp = alloc_http_response())) + { + return cgi_error_memory(); + } + + if (NULL == (rsp->status = strdup("501 Not Implemented"))) + { + free_http_response(rsp); + return cgi_error_memory(); + } + + rsp->is_static = 1; + rsp->reason = RSP_REASON_UNSUPPORTED; + + return(finish_http_response(csp, rsp)); + } + } + } + } + return NULL; +} + + +/********************************************************************* + * + * Function : content_filters_enabled + * + * Description : Checks whether there are any content filters + * enabled for the current request. + * + * Parameters : + * 1 : csp = Current client state (buffers, headers, etc...) + * + * Returns : TRUE for yes, FALSE otherwise + * + *********************************************************************/ +inline int content_filters_enabled(const struct client_state *csp) +{ + return (((csp->rlist != NULL) && + (!list_is_empty(csp->action->multi[ACTION_MULTI_FILTER]))) || + (csp->action->flags & (ACTION_DEANIMATE|ACTION_JPEG_INSPECT))); +} + /* Local Variables: tab-width: 3