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Add the ability to register filters. This commit introduces a warning

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into the build.  This warning will be removed automatically, as soon as
we decide on a prototype for the function causing the warning.  That
decision is tied to which filtering mechanism we decide on.
Submitted by:	Ryan Bloom and Greg Stein


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85926 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Ryan Bloom
2000-07-28 20:31:02 +00:00
parent c90431e69c
commit f89738e6b6
6 changed files with 404 additions and 16 deletions
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2
include/httpd.h
View File

@@ -732,6 +732,8 @@ struct request_rec {
struct ap_rr_xlate *rrx;
#endif /*APACHE_XLATE*/
struct ap_filter_t *filters;
/* Things placed at the end of the record to avoid breaking binary
* compatibility. It would be nice to remember to reorder the entire
* record to improve 64bit alignment the next time we need to break

220
include/util_filter.h Normal file
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@@ -0,0 +1,220 @@
/* ====================================================================
* 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 AP_FILTER_H
#define AP_FILTER_H
#ifdef __cplusplus
extern "C" {
#endif
#ifdef APR_HAVE_STDARG_H
#include <stdarg.h>
#endif
#include "httpd.h"
#include "apr.h"
/*
* FILTER CHAIN
*
* Filters operate using a "chaining" mechanism. The filters are chained
* together into a sequence. When output is generated, it is passed through
* each of the filters on this chain, until it reaches the end (or "bottom")
* and is placed onto the network.
*
* The top of the chain, the code generating the output, is typically called
* a "content generator." The content generator's output is fed into the
* filter chain using the standard Apache output mechanisms: ap_rputs(),
* ap_rprintf(), ap_rwrite(), etc.
*
* Each filter is defined by a callback. This callback takes the output from
* the previous filter (or the content generator if there is no previous
* filter), operates on it, and passes the result to the next filter in the
* chain. This pass-off is performed using the ap_fc_* functions, such as
* ap_fc_puts(), ap_fc_printf(), ap_fc_write(), etc.
*
* When content generation is complete, the system will pass an "end of
* stream" marker into the filter chain. The filters will use this to flush
* out any internal state and to detect incomplete syntax (for example, an
* unterminated SSI directive).
*/
/* forward declare the filter type */
typedef struct ap_filter_t ap_filter_t;
/*
* ap_filter_func:
*
* This function type is used for filter callbacks. It will be passed a
* pointer to "this" filter, and a "bucket" containing the content to be
* filtered.
*
* In filter->ctx, the callback will find its context. This context is
* provided here, so that a filter may be installed multiple times, each
* receiving its own per-install context pointer.
*
* Callbacks are associated with a filter definition, which is specified
* by name. See ap_register_filter() for setting the association between
* a name for a filter and its associated callback (and other information).
*
* The *bucket structure (and all those referenced by ->next and ->prev)
* should be considered "const". The filter is allowed to modify the
* next/prev to insert/remove/replace elements in the bucket list, but
* the types and values of the individual buckets should not be altered.
*/
typedef ap_status_t (*ap_filter_func)();
/*
* ap_filter_type:
*
* Filters have different types/classifications. These are used to group
* and sort the filters to properly sequence their operation.
*
* AP_FTYPE_CONTENT:
* These filters are used to alter the content that is passed through
* them. Examples are SSI or PHP.
*
* AP_FTYPE_CONNECTION:
* These filters will alter the content, but in ways that are more
* strongly associated with the output connection. Examples are
* compression, character recoding, or chunked transfer coding.
*
* It is important to note that these types of filters are not allowed
* in a sub-request. A sub-requests output can certainly be filtered
* by AP_FTYPE_CONTENT filters, but all of the "final processing" is
* determined by the main request.
*
* The types have a particular sort order, which allows us to insert them
* into the filter chain in a determistic order. Within a particular grouping,
* the ordering is equivalent to the order of calls to ap_add_filter().
*/
typedef enum {
AP_FTYPE_CONTENT,
AP_FTYPE_CONNECTION
} ap_filter_type;
/*
* ap_filter_t:
*
* This is the request-time context structure for an installed filter (in
* the output filter chain). It provides the callback to use for filtering,
* the request this filter is associated with (which is important when
* an output chain also includes sub-request filters), the context for this
* installed filter, and the filter ordering/chaining fields.
*
* Filter callbacks are free to use ->ctx as they please, to store context
* during the filter process. Generally, this is superior over associating
* the state directly with the request. A callback should not change any of
* the other fields.
*/
struct ap_filter_t {
ap_filter_func filter_func;
void *ctx;
ap_filter_type ftype;
ap_filter_t *next;
};
/*
* ap_register_filter():
*
* This function is used to register a filter with the system. After this
* registration is performed, then a filter may be added into the filter
* chain by using ap_add_filter() and simply specifying the name.
*
* The filter's callback and type should be passed.
*/
API_EXPORT(void) ap_register_filter(const char *name,
ap_filter_func filter_func,
ap_filter_type ftype);
/*
* ap_add_filter():
*
* Adds a named filter into the filter chain on the specified request record.
* The filter will be installed with the specified context pointer.
*
* Filters added in this way will always be placed at the end of the filters
* that have the same type (thus, the filters have the same order as the
* calls to ap_add_filter). If the current filter chain contains filters
* from another request, then this filter will be added before those other
* filters.
*/
API_EXPORT(void) ap_add_filter(const char *name, void *ctx, request_rec *r);
/*
* Things to do later:
* Add parameters to ap_filter_func type. Those parameters will be something
* like:
* (request_rec *r, ap_filter_t *filter, ap_data_list *the_data)
* obviously, the request_rec is the current request, and the filter
* is the current filter stack. The data_list is a bucket list or
* bucket_brigade, but I am trying to keep this patch neutral. (If this
* comment breaks that, well sorry, but the information must be there
* somewhere. :-)
*
* Add a function like ap_pass_data. This function will basically just
* call the next filter in the chain, until the current filter is NULL. If the
* current filter is NULL, that means that nobody wrote to the network, and
* we have a HUGE bug, so we need to return an error and log it to the
* log file.
*/
#ifdef __cplusplus
}
#endif
#endif /* !AP_FILTER_H */

19
modules/http/http_protocol.c
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@@ -1278,8 +1278,19 @@ void ap_set_sub_req_protocol(request_rec *rnew, const request_rec *r)
rnew->main = (request_rec *) r;
}
static void end_output_stream(request_rec *r)
{
/*
** ### place holder to tell filters that no more content will be
** ### arriving. typically, they will flush any pending content
*/
}
void ap_finalize_sub_req_protocol(request_rec *sub)
{
/* tell the filter chain there is no more content coming */
end_output_stream(sub);
SET_BYTES_SENT(sub->main);
}
@@ -1833,11 +1844,6 @@ API_EXPORT(void) ap_send_http_header(request_rec *r)
#endif /*APACHE_XLATE*/
}
static void flush_filters(request_rec *r)
{
/* ### place holder to flush pending content through the filters */
}
/* finalize_request_protocol is called at completion of sending the
* response. It's sole purpose is to send the terminating protocol
* information for any wrappers around the response message body
@@ -1845,7 +1851,8 @@ static void flush_filters(request_rec *r)
*/
API_EXPORT(void) ap_finalize_request_protocol(request_rec *r)
{
flush_filters(r);
/* tell the filter chain there is no more content coming */
end_output_stream(r);
if (r->chunked && !r->connection->aborted) {
#ifdef APACHE_XLATE

20
modules/http/http_request.c
View File

@@ -770,6 +770,9 @@ API_EXPORT(request_rec *) ap_sub_req_method_uri(const char *method,
rnew->htaccess = r->htaccess;
rnew->per_dir_config = r->server->lookup_defaults;
/* start with the same set of output filters */
rnew->filters = r->filters;
ap_set_sub_req_protocol(rnew, r);
/* would be nicer to pass "method" to ap_set_sub_req_protocol */
@@ -858,6 +861,9 @@ API_EXPORT(request_rec *) ap_sub_req_lookup_file(const char *new_file,
rnew->htaccess = r->htaccess;
rnew->chunked = r->chunked;
/* start with the same set of output filters */
rnew->filters = r->filters;
ap_set_sub_req_protocol(rnew, r);
fdir = ap_make_dirstr_parent(rnew->pool, r->filename);
@@ -961,16 +967,22 @@ API_EXPORT(request_rec *) ap_sub_req_lookup_file(const char *new_file,
API_EXPORT(int) ap_run_sub_req(request_rec *r)
{
#ifndef APACHE_XLATE
int retval = ap_invoke_handler(r);
#else /*APACHE_XLATE*/
/* Save the output conversion setting of the caller across subrequests */
int retval;
/* see comments in process_request_internal() */
ap_run_insert_filter(r);
#ifndef APACHE_XLATE
retval = ap_invoke_handler(r);
#else /*APACHE_XLATE*/
{
/* Save the output conversion setting across subrequests */
ap_xlate_t *saved_xlate;
ap_bgetopt(r->connection->client, BO_WXLATE, &saved_xlate);
retval = ap_invoke_handler(r);
ap_bsetopt(r->connection->client, BO_WXLATE, &saved_xlate);
}
#endif /*APACHE_XLATE*/
ap_finalize_sub_req_protocol(r);
return retval;

3
server/Makefile.in
View File

@@ -8,7 +8,8 @@ LTLIBRARY_SOURCES = \
http_protocol.c http_request.c http_vhost.c util.c util_date.c \
util_script.c util_uri.c util_md5.c util_cfgtree.c util_ebcdic.c \
rfc1413.c http_connection.c iol_file.c iol_socket.c listen.c \
mpm_common.c util_charset.c util_debug.c util_xml.c
mpm_common.c util_charset.c util_debug.c util_xml.c \
util_filter.c
include $(top_srcdir)/build/ltlib.mk

146
server/util_filter.c Normal file
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@@ -0,0 +1,146 @@
/* ====================================================================
* 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 "util_filter.h"
/*
* ap_filter_rec_t:
*
* This (internal) structure is used for recording information about the
* registered filters. It associates a name with the filter's callback
* and filter type.
*
* At the moment, these are simply linked in a chain, so a ->next pointer
* is available.
*/
typedef struct ap_filter_rec_t {
const char *name;
ap_filter_func filter_func;
ap_filter_type ftype;
struct ap_filter_rec_t *next;
} ap_filter_rec_t;
/* ### make this visible for direct manipulation?
### use a hash table
*/
static ap_filter_rec_t *registered_filters = NULL;
/* NOTE: Apache's current design doesn't allow a pool to be passed thu,
so we depend on a global to hold the correct pool
*/
#define FILTER_POOL ap_global_hook_pool
#include "ap_hooks.h" /* for ap_global_hook_pool */
/*
** This macro returns true/false if a given filter should be inserted BEFORE
** another filter. This will happen when one of: 1) there isn't another
** filter; 2) that filter has a higher filter type (class); 3) that filter
** corresponds to a different request.
*/
#define INSERT_BEFORE(f, before_this) ((before_this) == NULL \
|| (before_this)->ftype > (f)->ftype)
static ap_status_t filter_cleanup(void *ctx)
{
registered_filters = NULL;
return APR_SUCCESS;
}
API_EXPORT(void) ap_register_filter(const char *name,
ap_filter_func filter_func,
ap_filter_type ftype)
{
ap_filter_rec_t *frec = ap_palloc(FILTER_POOL, sizeof(*frec));
frec->name = name;
frec->filter_func = filter_func;
frec->ftype = ftype;
frec->next = registered_filters;
registered_filters = frec;
ap_register_cleanup(FILTER_POOL, NULL, filter_cleanup, NULL);
}
API_EXPORT(void) ap_add_filter(const char *name, void *ctx, request_rec *r)
{
ap_filter_rec_t *frec = registered_filters;
for (; frec != NULL; frec = frec->next) {
if (!strcasecmp(name, frec->name)) {
ap_filter_t *f = ap_pcalloc(r->pool, sizeof(*f));
f->filter_func = frec->filter_func;
f->ctx = ctx;
f->ftype = frec->ftype;
if (INSERT_BEFORE(f, r->filters)) {
f->next = r->filters;
r->filters = f;
}
else {
ap_filter_t *fscan = r->filters;
while (!INSERT_BEFORE(f, fscan->next))
fscan = fscan->next;
f->next = fscan->next;
fscan->next = f;
}
break;
}
}
}