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filters.h

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#ifndef FILTERS_H_INCLUDED
#define FILTERS_H_INCLUDED
#define FILTERS_H_VERSION "$Id: filters.h,v 2.0 2002/06/04 14:34:21 jongfoster Exp $"
/* ******************************************************************
 * $Source: /cvsroot/ijbswa/current/src/filters.h,v $
 * ******************************************************************
 *
 * Written by and Copyright (C) 2001 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.
 * 
 * *****************************************************************/
/**
 * @file
 *
 * Declares functions to parse/crunch headers and pages.
 * Functions declared include:
 * `acl_addr', `add_stats', `block_acl', `block_imageurl',
 * `block_url', `url_actions', `filter_popups', `forward_url'
 * `ij_untrusted_url', `intercept_url', `re_process_buffer',
 * `show_proxy_args', and `trust_url'
 * 
 *
 * $Log: filters.h,v $
 * Revision 2.0  2002/06/04 14:34:21  jongfoster
 * Moving source files to src/
 * 
 * Revision 1.20  2002/04/02 14:56:16  oes
 * Bugfix: is_untrusted_url() and trust_url() now depend on FEATURE_TRUST, not FEATURE_COOKIE_JAR
 * 
 * Revision 1.19  2002/03/26 22:29:54  swa
 * we have a new homepage!
 * 
 * Revision 1.18  2002/03/25 22:12:45  oes
 * Added fix for undefined INADDR_NONE on Solaris by Bart Schelstraete
 * 
 * Revision 1.17  2002/03/24 13:25:43  swa
 * name change related issues
 * 
 * Revision 1.16  2002/01/17 21:01:02  jongfoster
 * Moving all our URL and URL pattern parsing code to urlmatch.c.
 * 
 * Revision 1.15  2001/10/10 16:44:16  oes
 * Added match_portlist function
 * 
 * Revision 1.14  2001/10/07 15:41:40  oes
 * Added prototype for remove_chunked_transfer_coding
 * 
 * Revision 1.13  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 1.12  2001/07/29 19:01:11  jongfoster
 * Changed _FILENAME_H to FILENAME_H_INCLUDED.
 * Added forward declarations for needed structures.
 * 
 * Revision 1.11  2001/07/13 14:00:18  oes
 *  - Introduced gif_deanimate_response
 *  - Renamed re_process_buffer to pcrs_filter_response
 *  - Removed all #ifdef PCRS
 * 
 * Revision 1.10  2001/06/29 13:29:01  oes
 * Cleaned up and updated to reflect the changesin
 * filters.c
 * 
 * Revision 1.9  2001/06/07 23:10:53  jongfoster
 * Replacing struct gateway with struct forward_spec
 * 
 * Revision 1.8  2001/06/03 19:12:00  oes
 * extracted-CGI relevant stuff
 * 
 * Revision 1.7  2001/05/31 21:21:30  jongfoster
 * Permissionsfile / actions file changes:
 * - Changed "permission" to "action" throughout
 * - changes to file format to allow string parameters
 * - Moved helper functions to actions.c
 * 
 * Revision 1.6  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 1.5  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 1.4  2001/05/26 15:26:15  jongfoster
 * ACL feature now provides more security by immediately dropping
 * connections from untrusted hosts.
 * 
 * Revision 1.3  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 1.2  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 1.1.1.1  2001/05/15 13:58:52  oes
 * Initial import of version 2.9.3 source tree
 * 
 * 
 */
/* *****************************************************************/


#include "project.h"

#ifdef __cplusplus
extern "C" {
#endif


struct access_control_addr;
struct client_state;
struct http_request;
struct http_response;
struct current_action_spec;
struct url_actions;
struct url_spec;


/*
 * ACL checking
 */
#ifdef FEATURE_ACL
extern int block_acl(struct access_control_addr *dst, struct client_state *csp);
extern int acl_addr(char *aspec, struct access_control_addr *aca);
#endif /* def FEATURE_ACL */
extern int match_portlist(const char *portlist, int port);

/*
 * Interceptors
 */
extern struct http_response *block_url(struct client_state *csp);
extern struct http_response *redirect_url(struct client_state *csp);
#ifdef FEATURE_TRUST
extern struct http_response *trust_url(struct client_state *csp);
#endif /* def FEATURE_TRUST */

/*
 * Request inspectors
 */
#ifdef FEATURE_TRUST
extern int is_untrusted_url(struct client_state *csp);
#endif /* def FEATURE_TRUST */
#ifdef FEATURE_IMAGE_BLOCKING
extern int is_imageurl(struct client_state *csp);
#endif /* def FEATURE_IMAGE_BLOCKING */

/*
 * Determining applicable actions
 */
extern void url_actions(struct http_request *http, 
                        struct client_state *csp);
extern void apply_url_actions(struct current_action_spec *action, 
                              struct http_request *http, 
                              struct url_actions *b);
/*
 * Determining parent proxies
 */
extern const struct forward_spec *forward_url(struct http_request *http, struct client_state *csp);

/*
 * Content modification
 */
extern char *pcrs_filter_response(struct client_state *csp);
extern char *gif_deanimate_response(struct client_state *csp);
extern int remove_chunked_transfer_coding(char *buffer, const size_t size);

/*
 * Solaris fix:
 */
#ifndef INADDR_NONE
#define INADDR_NONE -1
#endif     

/* 
 * Revision control strings from this header and associated .c file
 */

/** Version information about filters.c. */
extern const char filters_rcs[];

/** Version information about filters.h. */
extern const char filters_h_rcs[];

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* ndef FILTERS_H_INCLUDED */

/*
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  tab-width: 3
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*/

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