mod_example.c revision 066877f1a045103acfdd376d48cdd473c33f409b
/* ====================================================================
* 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
* 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
*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
/*
* Apache example module. Provide demonstrations of how modules do things.
*
*/
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_log.h"
#include "http_main.h"
#include "http_protocol.h"
#include "http_request.h"
#include "util_script.h"
#include "apr_strings.h"
#include <stdio.h>
/*--------------------------------------------------------------------------*/
/* */
/* Data declarations. */
/* */
/* Here are the static cells and structure declarations private to our */
/* module. */
/* */
/*--------------------------------------------------------------------------*/
/*
* Sample configuration record. Used for both per-directory and per-server
* configuration data.
*
* It's perfectly reasonable to have two different structures for the two
* different environments. The same command handlers will be called for
* both, though, so the handlers need to be able to tell them apart. One
* possibility is for both structures to start with an int which is zero for
* one and 1 for the other.
*
* Note that while the per-directory and per-server configuration records are
* available to most of the module handlers, they should be treated as
* READ-ONLY by all except the command and merge handlers. Sometimes handlers
* are handed a record that applies to the current location by implication or
* inheritance, and modifying it will change the rules for other locations.
*/
typedef struct excfg {
int cmode; /* Environment to which record applies (directory,
* server, or combination).
*/
#define CONFIG_MODE_SERVER 1
#define CONFIG_MODE_DIRECTORY 2
int local; /* Boolean: "Example" directive declared here? */
int congenital; /* Boolean: did we inherit an "Example"? */
char *trace; /* Pointer to trace string. */
char *loc; /* Location to which this record applies. */
} excfg;
/*
* Let's set up a module-local static cell to point to the accreting callback
* trace. As each API callback is made to us, we'll tack on the particulars
* to whatever we've already recorded. To avoid massive memory bloat as
* directories are walked again and again, we record the routine/environment
* the first time (non-request context only), and ignore subsequent calls for
* the same routine/environment.
*/
/*
* To avoid leaking memory from pools other than the per-request one, we
* allocate a module-private pool, and then use a sub-pool of that which gets
* freed each time we modify the trace. That way previous layers of trace
* data don't get lost.
*/
/*
* Declare ourselves so the configuration routines can find and know us.
* We'll fill it in at the end of the module.
*/
/*--------------------------------------------------------------------------*/
/* */
/* The following pseudo-prototype declarations illustrate the parameters */
/* passed to command handlers for the different types of directive */
/* syntax. If an argument was specified in the directive definition */
/* (look for "command_rec" below), it's available to the command handler */
/* via the (void *) info field in the cmd_parms argument passed to the */
/* handler (cmd->info for the examples below). */
/* */
/*--------------------------------------------------------------------------*/
/*
* Command handler for a NO_ARGS directive.
*
* static const char *handle_NO_ARGS(cmd_parms *cmd, void *mconfig);
*/
/*
* Command handler for a RAW_ARGS directive. The "args" argument is the text
* of the commandline following the directive itself.
*
* static const char *handle_RAW_ARGS(cmd_parms *cmd, void *mconfig,
* const char *args);
*/
/*
* Command handler for a FLAG directive. The single parameter is passed in
* "bool", which is either zero or not for Off or On respectively.
*
* static const char *handle_FLAG(cmd_parms *cmd, void *mconfig, int bool);
*/
/*
* Command handler for a TAKE1 directive. The single parameter is passed in
* "word1".
*
* static const char *handle_TAKE1(cmd_parms *cmd, void *mconfig,
* char *word1);
*/
/*
* Command handler for a TAKE2 directive. TAKE2 commands must always have
* exactly two arguments.
*
* static const char *handle_TAKE2(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2);
*/
/*
* Command handler for a TAKE3 directive. Like TAKE2, these must have exactly
* three arguments, or the parser complains and doesn't bother calling us.
*
* static const char *handle_TAKE3(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2, char *word3);
*/
/*
* Command handler for a TAKE12 directive. These can take either one or two
* arguments.
* - word2 is a NULL pointer if no second argument was specified.
*
* static const char *handle_TAKE12(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2);
*/
/*
* Command handler for a TAKE123 directive. A TAKE123 directive can be given,
* as might be expected, one, two, or three arguments.
* - word2 is a NULL pointer if no second argument was specified.
* - word3 is a NULL pointer if no third argument was specified.
*
* static const char *handle_TAKE123(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2, char *word3);
*/
/*
* Command handler for a TAKE13 directive. Either one or three arguments are
* permitted - no two-parameters-only syntax is allowed.
* - word2 and word3 are NULL pointers if only one argument was specified.
*
* static const char *handle_TAKE13(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2, char *word3);
*/
/*
* Command handler for a TAKE23 directive. At least two and as many as three
* arguments must be specified.
* - word3 is a NULL pointer if no third argument was specified.
*
* static const char *handle_TAKE23(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2, char *word3);
*/
/*
* Command handler for a ITERATE directive.
* - Handler is called once for each of n arguments given to the directive.
* - word1 points to each argument in turn.
*
* static const char *handle_ITERATE(cmd_parms *cmd, void *mconfig,
* char *word1);
*/
/*
* Command handler for a ITERATE2 directive.
* - Handler is called once for each of the second and subsequent arguments
* given to the directive.
* - word1 is the same for each call for a particular directive instance (the
* first argument).
* - word2 points to each of the second and subsequent arguments in turn.
*
* static const char *handle_ITERATE2(cmd_parms *cmd, void *mconfig,
* char *word1, char *word2);
*/
/*--------------------------------------------------------------------------*/
/* */
/* These routines are strictly internal to this module, and support its */
/* operation. They are not referenced by any external portion of the */
/* server. */
/* */
/*--------------------------------------------------------------------------*/
/*
* Locate our directory configuration record for the current request.
*/
{
}
#if 0
/*
* Locate our server configuration record for the specified server.
*/
{
}
/*
* Likewise for our configuration record for the specified request.
*/
{
}
#endif
/*
* This routine sets up some module-wide cells if they haven't been already.
*/
static void setup_module_cells(void)
{
/*
* If we haven't already allocated our module-private pool, do so now.
*/
if (example_pool == NULL) {
};
/*
* Likewise for the apr_table_t of routine/environment pairs we visit outside of
* request context.
*/
if (static_calls_made == NULL) {
};
}
/*
* This routine is used to add a trace of a callback to the list. We're
* passed the server record (if available), the request record (if available),
* a pointer to our private configuration record (if available) for the
* environment to which the callback is supposed to apply, and some text. We
* turn this into a textual representation and add it to the tail of the list.
* The list can be displayed by the example_handler() routine.
*
* If the call occurs within a request context (i.e., we're passed a request
* record), we put the trace into the request apr_pool_t and attach it to the
* request via the notes mechanism. Otherwise, the trace gets added
* to the static (non-request-specific) list.
*
* Note that the r->notes apr_table_t is only for storing strings; if you need to
* maintain per-request data of any other type, you need to use another
* mechanism.
*/
#define TRACE_NOTE "example-trace"
const char *note)
{
const char *sofar;
char *addon;
char *where;
apr_pool_t *p;
const char *trace_copy;
/*
* Make sure our pools and tables are set up - we need 'em.
*/
/*
* Now, if we're in request-context, we use the request pool.
*/
if (r != NULL) {
p = r->pool;
trace_copy = "";
}
}
else {
/*
* We're not in request context, so the trace gets attached to our
* in non-request context; this avoids leaking memory in some of
* the subsequent calls that allocate memory only once (such as the
* key formation below).
*
* Make a new sub-pool and copy any existing trace to it. Point the
* trace cell at the copied value.
*/
apr_pool_create(&p, example_pool);
}
/*
* Now, if we have a sub-pool from before, nuke it and replace with
* the one we just allocated.
*/
if (example_subpool != NULL) {
}
example_subpool = p;
trace_copy = trace;
}
/*
* If we weren't passed a configuration record, we can't figure out to
* what location this call applies. This only happens for co-routines
* that don't operate in a particular directory or server context. If we
* got a valid record, extract the location (directory or server) to which
* it applies.
*/
/*
* Now, if we're not in request context, see if we've been called with
* this particular combination before. The apr_table_t is allocated in the
* module's private pool, which doesn't get destroyed.
*/
if (r == NULL) {
char *key;
/*
* Been here, done this.
*/
return;
}
else {
/*
* First time for this combination of routine and environment -
* log it so we don't do it again.
*/
}
}
" </LI>\n", NULL);
if (r != NULL) {
}
else {
trace = trace_copy;
}
/*
* You *could* change the following if you wanted to see the calling
* sequence reported in the server's error_log, but beware - almost all of
* these co-routines are called for every single request, and the impact
* on the size (and readability) of the error_log is considerable.
*/
#define EXAMPLE_LOG_EACH 0
if (EXAMPLE_LOG_EACH && (s != NULL)) {
}
}
/*--------------------------------------------------------------------------*/
/* We prototyped the various syntax for command handlers (routines that */
/* are called when the configuration parser detects a directive declared */
/* by our module) earlier. Now we actually declare a "real" routine that */
/* will be invoked by the parser when our "real" directive is */
/* encountered. */
/* */
/* If a command handler encounters a problem processing the directive, it */
/* signals this fact by returning a non-NULL pointer to a string */
/* describing the problem. */
/* */
/* The magic return value DECLINE_CMD is used to deal with directives */
/* that might be declared by multiple modules. If the command handler */
/* returns NULL, the directive was processed; if it returns DECLINE_CMD, */
/* the next module (if any) that declares the directive is given a chance */
/* at it. If it returns any other value, it's treated as the text of an */
/* error message. */
/*--------------------------------------------------------------------------*/
/*
* Command handler for the NO_ARGS "Example" directive. All we do is mark the
* call in the trace log, and flag the applicability of the directive to the
* current location in that location's configuration record.
*/
{
/*
* "Example Wuz Here"
*/
return NULL;
}
/*--------------------------------------------------------------------------*/
/* */
/* Now we declare our content handlers, which are invoked when the server */
/* encounters a document which our module is supposed to have a chance to */
/* see. (See mod_mime's SetHandler and AddHandler directives, and the */
/* mod_info and mod_status examples, for more details.) */
/* */
/* Since content handlers are dumping data directly into the connexion */
/* (using the r*() routines, such as rputs() and rprintf()) without */
/* intervention by other parts of the server, they need to make */
/* sure any accumulated HTTP headers are sent first. This is done by */
/* calling send_http_header(). Otherwise, no header will be sent at all, */
/* and the output sent to the client will actually be HTTP-uncompliant. */
/*--------------------------------------------------------------------------*/
/*
* Sample content handler. All this does is display the call list that has
* been built up so far.
*
* The return value instructs the caller concerning what happened and what to
* do next:
* OK ("we did our thing")
* DECLINED ("this isn't something with which we want to get involved")
* HTTP_mumble ("an error status should be reported")
*/
static int example_handler(request_rec *r)
{
dcfg = our_dconfig(r);
/*
* We're about to start sending content, so we need to force the HTTP
* headers to be sent at this point. Otherwise, no headers will be sent
* at all. We can set any we like first, of course. **NOTE** Here's
* where you set the "Content-type" header, and you do so by putting it in
* r->content_type, *not* r->headers_out("Content-type"). If you don't
* set it, it will be filled in with the server's default type (typically
* case.
*
* We also need to start a timer so the server can know if the connexion
* is broken.
*/
r->content_type = "text/html";
/*
* If we're only supposed to send header information (HEAD request), we're
* already there.
*/
if (r->header_only) {
return OK;
}
/*
* Now send our actual output. Since we tagged this as being
*/
ap_rputs(DOCTYPE_HTML_3_2, r);
ap_rputs("<HTML>\n", r);
ap_rputs(" <HEAD>\n", r);
ap_rputs(" <TITLE>mod_example Module Content-Handler Output\n", r);
ap_rputs(" </TITLE>\n", r);
ap_rputs(" </HEAD>\n", r);
ap_rputs(" <BODY>\n", r);
ap_rputs(" <H1><SAMP>mod_example</SAMP> Module Content-Handler Output\n", r);
ap_rputs(" </H1>\n", r);
ap_rputs(" <P>\n", r);
ap_rprintf(r, " Apache HTTP Server version: \"%s\"\n",
ap_rputs(" <BR>\n", r);
ap_rputs(" </P>\n", r);;
ap_rputs(" <P>\n", r);
ap_rputs(" The format for the callback trace is:\n", r);
ap_rputs(" </P>\n", r);
ap_rputs(" <DL>\n", r);
ap_rputs(" <DT><EM>n</EM>.<SAMP><routine-name>", r);
ap_rputs("(<routine-data>)</SAMP>\n", r);
ap_rputs(" </DT>\n", r);
ap_rputs(" <DD><SAMP>[<applies-to>]</SAMP>\n", r);
ap_rputs(" </DD>\n", r);
ap_rputs(" </DL>\n", r);
ap_rputs(" <P>\n", r);
ap_rputs(" The <SAMP><routine-data></SAMP> is supplied by\n", r);
ap_rputs(" the routine when it requests the trace,\n", r);
ap_rputs(" and the <SAMP><applies-to></SAMP> is extracted\n", r);
ap_rputs(" from the configuration record at the time of the trace.\n", r);
ap_rputs(" <STRONG>SVR()</STRONG> indicates a server environment\n", r);
ap_rputs(" (blank means the main or default server, otherwise it's\n", r);
ap_rputs(" the name of the VirtualHost); <STRONG>DIR()</STRONG>\n", r);
ap_rputs(" indicates a location in the URL or filesystem\n", r);
ap_rputs(" namespace.\n", r);
ap_rputs(" </P>\n", r);
ap_rprintf(r, " <H2>Static callbacks so far:</H2>\n <OL>\n%s </OL>\n",
trace);
ap_rputs(" <H2>Request-specific callbacks so far:</H2>\n", r);
ap_rputs(" <H2>Environment for <EM>this</EM> call:</H2>\n", r);
ap_rputs(" <UL>\n", r);
ap_rprintf(r, " <LI>\"Example\" directive declared here: %s\n </LI>\n",
ap_rprintf(r, " <LI>\"Example\" inherited: %s\n </LI>\n",
ap_rputs(" </UL>\n", r);
ap_rputs(" </BODY>\n", r);
ap_rputs("</HTML>\n", r);
/*
* We're all done, so cancel the timeout we set. Since this is probably
* the end of the request we *could* assume this would be done during
* post-processing - but it's possible that another handler might be
* called and inherit our outstanding timer. Not good; to each its own.
*/
/*
* We did what we wanted to do, so tell the rest of the server we
* succeeded.
*/
return OK;
}
/*--------------------------------------------------------------------------*/
/* */
/* Now let's declare routines for each of the callback phase in order. */
/* (That's the order in which they're listed in the callback list, *not */
/* the order in which the server calls them! See the command_rec */
/* declaration near the bottom of this file.) Note that these may be */
/* called for situations that don't relate primarily to our function - in */
/* other words, the fixup handler shouldn't assume that the request has */
/* to do with "example" stuff. */
/* */
/* With the exception of the content handler, all of our routines will be */
/* called for each request, unless an earlier handler from another module */
/* aborted the sequence. */
/* */
/* Handlers that are declared as "int" can return the following: */
/* */
/* OK Handler accepted the request and did its thing with it. */
/* DECLINED Handler took no action. */
/* HTTP_mumble Handler looked at request and found it wanting. */
/* */
/* What the server does after calling a module handler depends upon the */
/* handler's return value. In all cases, if the handler returns */
/* DECLINED, the server will continue to the next module with an handler */
/* for the current phase. However, if the handler return a non-OK, */
/* non-DECLINED status, the server aborts the request right there. If */
/* the handler returns OK, the server's next action is phase-specific; */
/* see the individual handler comments below for details. */
/* */
/*--------------------------------------------------------------------------*/
/*
* This function is called during server initialisation. Any information
* that needs to be recorded must be in static cells, since there's no
* configuration record.
*
* There is no return value.
*/
/*
* All our module initialiser does is add its trace to the log.
*/
{
char *note;
char *sname = s->server_hostname;
/*
* Set up any module cells that ought to be initialised.
*/
/*
* The arbitrary text we add to our trace entry indicates for which server
* we're being called.
*/
}
/*
* This function is called when an heavy-weight process (such as a child) is
* being run down or destroyed. As with the child initialisation function,
* any information that needs to be recorded must be in static cells, since
* there's no configuration record.
*
* There is no return value.
*/
/*
* All our process-death routine does is add its trace to the log.
*/
{
server_rec *s = sv;
char *note;
char *sname = s->server_hostname;
/*
* The arbitrary text we add to our trace entry indicates for which server
* we're being called.
*/
return APR_SUCCESS;
}
/*
* This function is called during server initialisation when an heavy-weight
* process (such as a child) is being initialised. As with the
* module initialisation function, any information that needs to be recorded
* must be in static cells, since there's no configuration record.
*
* There is no return value.
*/
/*
* All our process initialiser does is add its trace to the log.
*/
{
char *note;
char *sname = s->server_hostname;
/*
* Set up any module cells that ought to be initialised.
*/
/*
* The arbitrary text we add to our trace entry indicates for which server
* we're being called.
*/
}
/*
* This function gets called to create a per-directory configuration
* record. This will be called for the "default" server environment, and for
* each directory for which the parser finds any of our directives applicable.
* If a directory doesn't have any of our directives involved (i.e., they
* aren't in the .htaccess file, or a <Location>, <Directory>, or related
* block), this routine will *not* be called - the configuration for the
* closest ancestor is used.
*
* The return value is a pointer to the created module-specific
* structure.
*/
{
/*
* Allocate the space for our record from the pool supplied.
*/
/*
* Now fill in the defaults. If there are any `parent' configuration
* records, they'll get merged as part of a separate callback.
*/
cfg->congenital = 0;
/*
* Finally, add our trace to the callback list.
*/
return (void *) cfg;
}
/*
* This function gets called to merge two per-directory configuration
* records. This is typically done to cope with things like .htaccess files
* or <Location> directives for directories that are beneath one for which a
* configuration record was already created. The routine has the
* responsibility of creating a new record and merging the contents of the
* other two into it appropriately. If the module doesn't declare a merge
* routine, the record for the closest ancestor location (that has one) is
* used exclusively.
*
* The routine MUST NOT modify any of its arguments!
*
* The return value is a pointer to the created module-specific structure
* containing the merged values.
*/
void *newloc_conf)
{
char *note;
/*
* Some things get copied directly from the more-specific record, rather
* than getting merged.
*/
/*
* Others, like the setting of the `congenital' flag, get ORed in. The
* setting of that particular flag, for instance, is TRUE if it was ever
* true anywhere in the upstream configuration.
*/
/*
* If we're merging records for two different types of environment (server
* and directory), mark the new record appropriately. Otherwise, inherit
* the current value.
*/
/*
* Now just record our being called in the trace list. Include the
* locations we were asked to merge.
*/
return (void *) merged_config;
}
/*
* This function gets called to create a per-server configuration
* record. It will always be called for the "default" server.
*
* The return value is a pointer to the created module-specific
* structure.
*/
{
char *sname = s->server_hostname;
/*
* As with the example_create_dir_config() reoutine, we allocate and fill
* in an empty record.
*/
cfg->congenital = 0;
/*
* Note that we were called in the trace list.
*/
return (void *) cfg;
}
/*
* This function gets called to merge two per-server configuration
* records. This is typically done to cope with things like virtual hosts and
* the default server configuration The routine has the responsibility of
* creating a new record and merging the contents of the other two into it
* appropriately. If the module doesn't declare a merge routine, the more
* specific existing record is used exclusively.
*
* The routine MUST NOT modify any of its arguments!
*
* The return value is a pointer to the created module-specific structure
* containing the merged values.
*/
void *server2_conf)
{
char *note;
/*
* Our inheritance rules are our own, and part of our module's semantics.
* Basically, just note whence we came.
*/
/*
* Trace our call, including what we were asked to merge.
*/
return (void *) merged_config;
}
/*
* This routine is called after the request has been read but before any other
* phases have been processed. This allows us to make decisions based upon
* the input header fields.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, no
* further modules are called for this phase.
*/
static int example_post_read_request(request_rec *r)
{
cfg = our_dconfig(r);
/*
* We don't actually *do* anything here, except note the fact that we were
* called.
*/
return DECLINED;
}
/*
* This routine gives our module an opportunity to translate the URI into an
* actual filename. If we don't do anything special, the server's default
* rules (Alias directives and the like) will continue to be followed.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, no
* further modules are called for this phase.
*/
static int example_translate_handler(request_rec *r)
{
cfg = our_dconfig(r);
/*
* We don't actually *do* anything here, except note the fact that we were
* called.
*/
return DECLINED;
}
/*
* This routine is called to check the authentication information sent with
* the request (such as looking up the user in a database and verifying that
* the [encrypted] password sent matches the one in the database).
*
* The return value is OK, DECLINED, or some HTTP_mumble error (typically
* HTTP_UNAUTHORIZED). If we return OK, no other modules are given a chance
* at the request during this phase.
*/
static int example_check_user_id(request_rec *r)
{
cfg = our_dconfig(r);
/*
* Don't do anything except log the call.
*/
return DECLINED;
}
/*
* This routine is called to check to see if the resource being requested
* requires authorisation.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, no
* other modules are called during this phase.
*
* If *all* modules return DECLINED, the request is aborted with a server
* error.
*/
static int example_auth_checker(request_rec *r)
{
cfg = our_dconfig(r);
/*
* Log the call and return OK, or access will be denied (even though we
* didn't actually do anything).
*/
return DECLINED;
}
/*
* This routine is called to check for any module-specific restrictions placed
* upon the requested resource. (See the mod_access module for an example.)
*
* The return value is OK, DECLINED, or HTTP_mumble. All modules with an
* handler for this phase are called regardless of whether their predecessors
* return OK or DECLINED. The first one to return any other status, however,
* will abort the sequence (and the request) as usual.
*/
static int example_access_checker(request_rec *r)
{
cfg = our_dconfig(r);
return DECLINED;
}
/*
* information bits, like Content-type (via r->content_type), language, et
* cetera.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, no
* further modules are given a chance at the request for this phase.
*/
static int example_type_checker(request_rec *r)
{
cfg = our_dconfig(r);
/*
* Log the call, but don't do anything else - and report truthfully that
* we didn't do anything.
*/
return DECLINED;
}
/*
* This routine is called to perform any module-specific fixing of header
* fields, et cetera. It is invoked just before any content-handler.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, the
* server will still call any remaining modules with an handler for this
* phase.
*/
static int example_fixer_upper(request_rec *r)
{
cfg = our_dconfig(r);
/*
* Log the call and exit.
*/
return OK;
}
/*
* This routine is called to perform any module-specific logging activities
* over and above the normal server things.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, any
* remaining modules with an handler for this phase will still be called.
*/
static int example_logger(request_rec *r)
{
cfg = our_dconfig(r);
return DECLINED;
}
/*
* This routine is called to give the module a chance to look at the request
* headers and take any appropriate specific actions early in the processing
* sequence.
*
* The return value is OK, DECLINED, or HTTP_mumble. If we return OK, any
* remaining modules with handlers for this phase will still be called.
*/
static int example_header_parser(request_rec *r)
{
cfg = our_dconfig(r);
return DECLINED;
}
/*--------------------------------------------------------------------------*/
/* */
/* Which functions are responsible for which hooks in the server. */
/* */
/*--------------------------------------------------------------------------*/
/*
* Each function our module provides to handle a particular hook is
* specified here. The functions are registered using
* ap_hook_foo(name, predecessors, successors, position)
* where foo is the name of the hook.
*
* The args are as follows:
* name -> the name of the function to call.
* predecessors -> a list of modules whose calls to this hook must come
* before this module.
* successors -> a list of modules whose calls to this hook must come
* after this module.
* position -> The relative position of this module. One of APR_HOOK_FIRST,
* APR_HOOK_MIDDLE, or APR_HOOK_LAST. Most modules will use
* APR_HOOK_MIDDLE. If multiple modules use the same relative
* position, Apache will determine which to call first.
* If your module relies on another module to run first,
* or another module running after yours, use the
*
* The number in brackets indicates the order in which the routine is called
* during request processing. Note that not all routines are necessarily
* called (such as if a resource doesn't have access restrictions).
* The actual delivery of content to the browser [9] is not handled by
* a hook; see the handler declarations below.
*/
static void example_register_hooks(apr_pool_t *p)
{
/* module initializer */
/* [1] post read_request handling */
/* [2] filename-to-URI translation */
/* [3] header parser */
/* [4] check access by host address */
/* [6] check user_id is valid *here* */
/* [8] fixups */
/* [9] is for the handlers; see below */
/* [10] logger */
/* process initializer */
}
/*--------------------------------------------------------------------------*/
/* */
/* All of the routines have been declared now. Here's the list of */
/* directives specific to our module, and information about where they */
/* may appear and how the command parser should pass them to us for */
/* processing. Note that care must be taken to ensure that there are NO */
/* collisions of directive names between modules. */
/* */
/*--------------------------------------------------------------------------*/
/*
* List of directives specific to our module.
*/
static const command_rec example_cmds[] =
{
"Example", /* directive name */
cmd_example, /* config action routine */
NULL, /* argument to include in call */
OR_OPTIONS, /* where available */
"Example directive - no arguments" /* directive description */
),
{NULL}
};
/*--------------------------------------------------------------------------*/
/* */
/* Now the list of content handlers available from this module. */
/* */
/*--------------------------------------------------------------------------*/
/*
* List of content handlers our module supplies. Each handler is defined by
* two parts: a name by which it can be referenced (such as by
* {Add,Set}Handler), and the actual routine name. The list is terminated by
* a NULL block, since it can be of variable length.
*
* Note that content-handlers are invoked on a most-specific to least-specific
* invoked before one that was declared for "text / *". Note also that
* if a content-handler returns anything except DECLINED, no other
* content-handlers will be called.
*/
static const handler_rec example_handlers[] =
{
{"example-handler", example_handler},
{NULL}
};
/*--------------------------------------------------------------------------*/
/* */
/* Finally, the list of callback routines and data structures that provide */
/* the static hooks into our module from the other parts of the server. */
/* */
/*--------------------------------------------------------------------------*/
/*
* Module definition for configuration. If a particular callback is not
* needed, replace its routine name below with the word NULL.
*/
{
example_create_dir_config, /* per-directory config creator */
example_merge_dir_config, /* dir config merger */
example_create_server_config, /* server config creator */
example_merge_server_config, /* server config merger */
example_cmds, /* command table */
example_handlers, /* list of content delivery handlers */
example_register_hooks, /* set up other request processing hooks */
};