Commit 1503951d authored by Ben Laurie's avatar Ben Laurie
Browse files

Generic hooks (and a demo content filter module). 


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87568 13f79535-47bb-0310-9956-ffa450edef68
parent d2229428

CHANGES

+2 −0
Original line number Diff line number Diff line 
Changes with Apache 2.0b1



  *) Add generic hooks. [Ben Laurie]



  *) Use a real pool to dup the error log descriptor.  [Ryan Bloom]



  *) Fix a segfault caused by mod_ext_filter when the external filter

include/ap_generic_hook.h

0 → 100644
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/* ====================================================================

 * The Apache Software License, Version 1.1

 *

 * Copyright (c) 2000 The Apache Software Foundation.  All rights

 * reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. The end-user documentation included with the redistribution,

 *    if any, must include the following acknowledgment:

 *       "This product includes software developed by the

 *        Apache Software Foundation (http://www.apache.org/)."

 *    Alternately, this acknowledgment may appear in the software itself,

 *    if and wherever such third-party acknowledgments normally appear.

 *

 * 4. The names "Apache" and "Apache Software Foundation" must

 *    not be used to endorse or promote products derived from this

 *    software without prior written permission. For written

 *    permission, please contact apache@apache.org.

 *

 * 5. Products derived from this software may not be called "Apache",

 *    nor may "Apache" appear in their name, without prior written

 *    permission of the Apache Software Foundation.

 *

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED

 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * ====================================================================

 *

 * This software consists of voluntary contributions made by many

 * individuals on behalf of the Apache Software Foundation.  For more

 * information on the Apache Software Foundation, please see

 * <http://www.apache.org/>.

 */



#ifndef APACHE_AP_GENERIC_HOOK_H

#define APACHE_AP_GENERIC_HOOK_H



#include "apr_tables.h"



/**

 * @package Apache hooks functions

 */



#define AP_DECLARE_GENERIC_HOOK(link,ret,name,args) \

typedef ret HOOK_##name args;



AP_DECLARE(void) ap_hook_generic(const char *szName,void (*pfn)(void),

				 const char * const *aszPre,

				 const char * const *aszSucc,int nOrder);



/**

 * Hook to a generic hook.

 *

 * @param name The name of the hook

 * @param pfn A pointer to a function that will be called

 * @param aszPre a NULL-terminated array of strings that name modules whose hooks should precede this one

 * @param aszSucc a NULL-terminated array of strings that name modules whose hooks should succeed this one

 * @param nOrder an integer determining order before honouring aszPre and aszSucc (for example HOOK_MIDDLE)

 */



#define AP_HOOK_GENERIC(name,pfn,aszPre,aszSucc,nOrder) \

    ((void (*)(const char *,HOOK_##name *,const char * const *, \

	       const char * const *,int))&ap_hook_generic)(#name,pfn,aszPre, \

							   aszSucc, nOrder)



apr_array_header_t *ap_generic_hook_get(const char *szName);



/**

 * Implement a generic hook that runs until one of the functions

 * returns something other than OK or DECLINE.

 *

 * @param ret The type of the return value of the hook

 * @param name The name of the hook

 * @param args_decl The declaration of the arguments for the hook

 * @param args_used The names for the arguments for the hook

 * @deffunc int AP_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(link, name, args_decl, args_use)

 */

#define AP_IMPLEMENT_GENERIC_HOOK_RUN_ALL(ret,name,args_decl,args_use,ok,decline) \

AP_DECLARE(ret) ap_run_##name args_decl \

    { \

    LINK_##name *pHook; \

    int n; \

    ret rv; \

    apr_array_header_t *pHookArray=ap_generic_hook_get(#name); \

\

    if(!pHookArray) \

	return ok; \

\

    pHook=(LINK_##name *)pHookArray->elts; \

    for(n=0 ; n < pHookArray->nelts ; ++n) \

	{ \

	rv=pHook[n].pFunc args_use; \

\

	if(rv != ok && rv != decline) \

	    return rv; \

	} \

    return ok; \

    }



#endif /* def APACHE_AP_GENERIC_HOOK_H */

modules/experimental/config.m4

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@@ -5,5 +5,8 @@ APACHE_MODULE(charset_lite, character set translation, , , no) 
APACHE_MODULE(cache, dynamic file caching, , , no)

APACHE_MODULE(disk_cache, disk caching module, , , no)

APACHE_MODULE(ext_filter, external filter module, , , no)

APACHE_MODULE(case_filter, example uppercase conversion filter, , , no)

APACHE_MODULE(generic_hook_export, example hook exporter, , , no)

APACHE_MODULE(generic_hook_import, example hook importer, , , no)



APACHE_MODPATH_FINISH

modules/experimental/mod_case_filter.c

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+113 −0
Original line number Diff line number Diff line 
// Ben messing around...



#include "httpd.h"

#include "http_config.h"

#include "apr_general.h"

#include "util_filter.h"

#include "ap_buckets.h"

#include "http_request.h"



static const char s_szCaseFilterName[]="CaseFilter";

module case_filter_module;



typedef struct

    {

    int bEnabled;

    } CaseFilterConfig;



static void *CaseFilterCreateServerConfig(apr_pool_t *p,server_rec *s)

    {

    CaseFilterConfig *pConfig=apr_pcalloc(p,sizeof *pConfig);



    pConfig->bEnabled=0;



    return pConfig;

    }



static void CaseFilterInsertFilter(request_rec *r)

    {

    CaseFilterConfig *pConfig=ap_get_module_config(r->server->module_config,

						   &case_filter_module);



    if(!pConfig->bEnabled)

	return;



    ap_add_output_filter(s_szCaseFilterName,NULL,r,r->connection);

    }



static apr_status_t CaseFilterOutFilter(ap_filter_t *f,

					ap_bucket_brigade *pbbIn)

    {

    ap_bucket *pbktIn;

    ap_bucket_brigade *pbbOut;



    // XXX: is this the most appropriate pool?

    pbbOut=ap_brigade_create(f->r->pool);

    AP_BRIGADE_FOREACH(pbktIn,pbbIn)

	{

	const char *data;

	apr_size_t len;

	char *buf;

	apr_size_t n;

	ap_bucket *pbktOut;



	if(AP_BUCKET_IS_EOS(pbktIn))

	    {

	    // XXX: why can't I reuse pbktIn???

	    ap_bucket *pbktEOS=ap_bucket_create_eos();

	    AP_BRIGADE_INSERT_TAIL(pbbOut,pbktEOS);

	    break;

	    }



	// read

	ap_bucket_read(pbktIn,&data,&len,1);



	// write

	buf=apr_palloc(f->r->pool,len);

	for(n=0 ; n < len ; ++n)

	    buf[n]=toupper(data[n]);



	// XXX: should we use a heap bucket instead? Or a transient (in

	// which case we need a separate brigade for each bucket)?

	pbktOut=ap_bucket_create_pool(buf,len,f->r->pool);

	AP_BRIGADE_INSERT_TAIL(pbbOut,pbktOut);

	}



    // XXX: is there any advantage to passing a brigade for each bucket?

    return ap_pass_brigade(f->next,pbbOut);

    }



static const char *CaseFilterEnable(cmd_parms *cmd, void *dummy, int arg)

    {

    CaseFilterConfig *pConfig=ap_get_module_config(cmd->server->module_config,

						   &case_filter_module);

    pConfig->bEnabled=arg;



    return NULL;

    }



static const command_rec CaseFilterCmds[] = 

    {

    AP_INIT_FLAG("CaseFilter", CaseFilterEnable, NULL, RSRC_CONF,

                 "Run a case filter on this host"),

    { NULL }

    };



static void CaseFilterRegisterHooks(void)

    {

    ap_hook_insert_filter(CaseFilterInsertFilter,NULL,NULL,AP_HOOK_MIDDLE);

    ap_register_output_filter(s_szCaseFilterName,CaseFilterOutFilter,

			      AP_FTYPE_CONTENT);

    }



module case_filter_module =

{

    STANDARD20_MODULE_STUFF,

    NULL,

    NULL,

    CaseFilterCreateServerConfig,

    NULL,

    CaseFilterCmds,

    NULL,

    CaseFilterRegisterHooks

};

modules/experimental/mod_generic_hook_export.c

0 → 100644
+83 −0
Original line number Diff line number Diff line 
/* ====================================================================

 * The Apache Software License, Version 1.1

 *

 * Copyright (c) 2000 The Apache Software Foundation.  All rights

 * reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. The end-user documentation included with the redistribution,

 *    if any, must include the following acknowledgment:

 *       "This product includes software developed by the

 *        Apache Software Foundation (http://www.apache.org/)."

 *    Alternately, this acknowledgment may appear in the software itself,

 *    if and wherever such third-party acknowledgments normally appear.

 *

 * 4. The names "Apache" and "Apache Software Foundation" must

 *    not be used to endorse or promote products derived from this

 *    software without prior written permission. For written

 *    permission, please contact apache@apache.org.

 *

 * 5. Products derived from this software may not be called "Apache",

 *    nor may "Apache" appear in their name, without prior written

 *    permission of the Apache Software Foundation.

 *

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED

 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 * ====================================================================

 *

 * This software consists of voluntary contributions made by many

 * individuals on behalf of the Apache Software Foundation.  For more

 * information on the Apache Software Foundation, please see

 * <http://www.apache.org/>.

 */



#include "httpd.h"

#include "http_config.h"

#include "mod_generic_hook_export.h"

#include "http_protocol.h"



AP_IMPLEMENT_GENERIC_HOOK_RUN_ALL(int,generic_hook_test,(const char *szStr),

				  (szStr),OK,DECLINED)



static int ExportLogTransaction(request_rec *r)

{

    return ap_run_generic_hook_test(r->the_request);

}



static void ExportRegisterHooks(void)

{

    ap_hook_log_transaction(ExportLogTransaction,NULL,NULL,AP_HOOK_MIDDLE);

}



module generic_hook_export_module =

{

    STANDARD20_MODULE_STUFF,

    NULL,

    NULL,

    NULL,

    NULL,

    NULL,

    NULL,

    ExportRegisterHooks

};