Initial import from apache 1.2.6

1 files changed, 1110 insertions, 0 deletions

diff --git a/usr.sbin/httpd/src/modules/example/mod_example.c b/usr.sbin/httpd/src/modules/example/mod_example.c
new file mode 100644
index 00000000000..1aeda876d01
--- /dev/null
+++ b/usr.sbin/httpd/src/modules/example/mod_example.c
@@ -0,0 +1,1110 @@
+/* ====================================================================
+ * Copyright (c) 1995-1997 The Apache Group.  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. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the Apache Group
+ *    for use in the Apache HTTP server project (http://www.apache.org/)."
+ *
+ * 4. The names "Apache Server" and "Apache Group" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission.
+ *
+ * 5. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the Apache Group
+ *    for use in the Apache HTTP server project (http://www.apache.org/)."
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``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 GROUP 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 Group and was originally based
+ * on public domain software written at the National Center for
+ * Supercomputing Applications, University of Illinois, Urbana-Champaign.
+ * For more information on the Apache Group and the Apache HTTP server
+ * project, please see <http://www.apache.org/>.
+ *
+ */
+
+/* 
+ * 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 "util_script.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 example_config {
+    int	    cmode;	/* Environment to which record applies (directory,  */
+			/* server, or combination).			    */
+#define CONFIG_MODE_SERVER 1
+#define CONFIG_MODE_DIRECTORY 2
+#define CONFIG_MODE_COMBO 3  /* Shouldn't ever happen.			    */
+    int	    local;	/* Boolean: was "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.	    */
+} example_config;
+
+/*
+ * 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.
+ */
+static char *trace = NULL;
+static table *static_calls_made = NULL;
+
+/*
+ * 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.
+ */
+static pool *example_pool = NULL;
+static pool *example_subpool = NULL;
+
+/*
+ * Declare ourselves so the configuration routines can find and know us.
+ * We'll fill it in at the end of the module.
+ */
+module example_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 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.
+ */
+static example_config *our_dconfig
+	(request_rec *r) {
+
+    return (example_config *) get_module_config
+				(
+				    r->per_dir_config,
+				    &example_module
+				);
+}
+
+/*
+ * Locate our server configuration record for the specified server.
+ */
+static example_config *our_sconfig
+	(server_rec *s) {
+
+    return (example_config *) get_module_config
+				(
+				    s->module_config,
+				    &example_module
+				);
+}
+
+/*
+ * Likewise for our configuration record for the specified request.
+ */
+static example_config *our_rconfig
+	(request_rec *r) {
+
+    return (example_config *) get_module_config
+				(
+				    r->request_config,
+				    &example_module
+				);
+}
+
+/*
+ * This routine sets up some module-wide cells if they haven't been already.
+ */
+static void setup_module_cells () {
+    /*
+     * If we haven't already allocated our module-private pool, do so now.
+     */
+    if (example_pool == NULL) {
+	example_pool = make_sub_pool (NULL);
+    };
+    /*
+     * Likewise for the table of routine/environment pairs we visit outside of
+     * request context.
+     */
+    if (static_calls_made == NULL) {
+	static_calls_made = make_table (example_pool, 16);
+    };
+}
+
+/*
+ * 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 pool 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 table 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"
+
+static void trace_add
+	(server_rec *s, request_rec *r, example_config *mconfig,
+	 const char *note) {
+
+    char    *sofar;
+    char    *addon;
+    char    *where;
+    pool    *p;
+    char    *trace_copy;
+    example_config
+	    *rconfig;
+
+    /*
+     * Make sure our pools and tables are set up - we need 'em.
+     */
+    setup_module_cells ();
+    /*
+     * Now, if we're in request-context, we use the request pool.
+     */
+    if (r != NULL) {
+	p = r->pool;
+	if ((trace_copy = table_get (r->notes, TRACE_NOTE)) == NULL) {
+	    trace_copy = "";
+	}
+    } else {
+	/*
+	 * We're not in request context, so the trace gets attached to our
+	 * module-wide pool.  We do the create/destroy every time we're called
+	 * 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.
+	 */
+	p = make_sub_pool (example_pool);
+	if (trace != NULL) {
+	    trace = pstrdup (p, trace);
+	}
+	/*
+	 * Now, if we have a sub-pool from before, nuke it and replace with
+	 * the one we just allocated.
+	 */
+	if (example_subpool != NULL) {
+	    destroy_pool (example_subpool);
+	}
+	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.
+     */
+    where = (mconfig != NULL) ? mconfig->loc : "nowhere";
+    where = (where != NULL) ? where : "";
+    /*
+     * Now, if we're not in request context, see if we've been called with
+     * this particular combination before.  The table is allocated in the
+     * module's private pool, which doesn't get destroyed.
+     */
+    if (r == NULL) {
+	char	*key;
+
+	key = pstrcat (p, note, ":", where, NULL);
+	if (table_get (static_calls_made, key) != NULL) {
+	    /*
+	     * Been here, done this.
+	     */
+	    return;
+	} else {
+	    /*
+	     * First time for this combination of routine and environment -
+	     * log it so we don't do it again.
+	     */
+	    table_set (static_calls_made, key, "been here");
+	}
+    }
+    addon = pstrcat 
+		(
+		    p,
+		    "   <LI>\n",
+		    "    <DL>\n",
+		    "     <DT><SAMP>",
+		    note,
+		    "</SAMP>\n",
+		    "     </DT>\n",
+		    "     <DD><SAMP>[",
+		    where,
+		    "]</SAMP>\n",
+		    "     </DD>\n",
+		    "    </DL>\n",
+		    "   </LI>\n",
+		    NULL
+		);
+    sofar = (trace_copy == NULL) ? "" : trace_copy;
+    trace_copy = pstrcat (p, sofar, addon, NULL);
+    if (r != NULL) {
+	table_set (r->notes, TRACE_NOTE, trace_copy);
+    } else {
+	trace = trace_copy;
+    }
+    /*
+     * You *could* uncomment 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.
+     */
+/*
+    if (s != NULL) {
+        log_printf (s, "mod_example: %s", note);
+    }
+ */
+}
+
+/*--------------------------------------------------------------------------*/
+/* 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.
+ */
+static const char *cmd_example
+	(cmd_parms *cmd, void *mconfig) {
+
+    example_config
+	    *cfg = (example_config *) mconfig;
+
+    /*
+     * "Example Wuz Here"
+     */
+    cfg->local = 1;
+    trace_add (cmd->server, NULL, cfg, "cmd_example()");
+    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) {
+
+    example_config
+	    *dcfg;
+    example_config
+	    *rcfg;
+
+    dcfg = our_dconfig (r);
+    trace_add (r->server, r, dcfg, "example_handler()");
+    /*
+     * 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
+     * "text/plain").
+     *
+     * We also need to start a timer so the server can know if the connexion
+     * is broken.
+     */
+    r->content_type = "text/html";
+    soft_timeout ("send example call trace", r);
+    send_http_header (r);
+    /*
+     * If we're only supposed to send header information (HEAD request), we're
+     * already there.
+     */
+    if (r->header_only) {
+	kill_timeout (r);
+	return OK;
+    }
+
+    /*
+     * Now send our actual output.  Since we tagged this as being
+     * "text/html", we need to embed any HTML.
+     */
+    rputs ("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 3.2//EN\">\n", r);
+    rputs ("<HTML>\n", r);
+    rputs (" <HEAD>\n", r);
+    rputs ("  <TITLE>mod_example Module Content-Handler Output\n", r);
+    rputs ("  </TITLE>\n", r);
+    rputs (" </HEAD>\n", r);
+    rputs (" <BODY>\n", r);
+    rputs ("  <H1><SAMP>mod_example</SAMP> Module Content-Handler Output\n", r);
+    rputs ("  </H1>\n", r);
+    rputs ("  <P>\n", r);
+    rputs ("  The format for the callback trace is:\n", r);
+    rputs ("  </P>\n", r);
+    rputs ("  <DL>\n", r);
+    rputs ("   <DT><EM>n</EM>.<SAMP>&lt;routine-name&gt;", r);
+    rputs ("(&lt;routine-data&gt;)</SAMP>\n", r);
+    rputs ("   </DT>\n", r);
+    rputs ("   <DD><SAMP>[&lt;applies-to&gt;]</SAMP>\n", r);
+    rputs ("   </DD>\n", r);
+    rputs ("  </DL>\n", r);
+    rputs ("  <P>\n", r);
+    rputs ("  The <SAMP>&lt;routine-data&gt;</SAMP> is supplied by\n", r);
+    rputs ("  the routine when it requests the trace,\n", r);
+    rputs ("  and the <SAMP>&lt;applies-to&gt;</SAMP> is extracted\n", r);
+    rputs ("  from the configuration record at the time of the trace.\n", r); 
+    rputs ("  <STRONG>SVR()</STRONG> indicates a server environment\n", r);
+    rputs ("  (blank means the main or default server, otherwise it's\n", r);
+    rputs ("  the name of the VirtualHost); <STRONG>DIR()</STRONG>\n", r);
+    rputs ("  indicates a location in the URL or filesystem\n", r);
+    rputs ("  namespace.\n", r);
+    rputs ("  </P>\n", r);
+    rprintf
+	(
+	    r,
+	    "  <H2>Static callbacks so far:</H2>\n  <OL>\n%s  </OL>\n",
+	    trace
+	);
+    rprintf
+	(
+	    r,
+	    "  <H2>Request-specific callbacks so far:</H2>\n  <OL>\n%s  </OL>\n",
+	    table_get (r->notes, TRACE_NOTE)
+	);
+    rputs ("  <H2>Environment for <EM>this</EM> call:</H2>\n", r);
+    rputs ("  <UL>\n", r);
+    rprintf (r, "   <LI>Applies-to: <SAMP>%s</SAMP>\n   </LI>\n", dcfg->loc);
+    rprintf
+	(
+	    r,
+	    "   <LI>\"Example\" directive declared here: %s\n   </LI>\n",
+	    (dcfg->local ? "YES" : "NO")
+	);
+    rprintf
+	(
+	    r,
+	    "   <LI>\"Example\" inherited: %s\n   </LI>\n",
+	    (dcfg->congenital ? "YES" : "NO")
+	);
+    rputs ("  </UL>\n", r);
+    rputs (" </BODY>\n", r);
+    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.
+     */
+    kill_timeout (r);
+    /*
+     * 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.
+ */
+static void example_init
+	(server_rec *s, pool *p) {
+
+    char    *note;
+    char    *sname = s->server_hostname;
+
+    /*
+     * Set up any module cells that ought to be initialised.
+     */
+    setup_module_cells ();
+    /*
+     * The arbitrary text we add to our trace entry indicates for which server
+     * we're being called.
+     */
+    sname = (sname != NULL) ? sname : "";
+    note = pstrcat (p, "example_init(", sname, ")", NULL);
+    trace_add (s, NULL, NULL, note);
+}
+
+/*
+ * This function gets called to create up 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.
+ */
+static void *example_dir_create
+	(pool *p, char *dirspec) {
+
+    example_config
+	    *cfg;
+    char    *dname = dirspec;
+
+    /*
+     * Allocate the space for our record from the pool supplied.
+     */
+    cfg = (example_config *) pcalloc (p, sizeof(example_config));
+    /*
+     * Now fill in the defaults.  If there are any `parent' configuration
+     * records, they'll get merged as part of a separate callback.
+     */
+    cfg->local = 0;
+    cfg->congenital = 0;
+    cfg->cmode = CONFIG_MODE_DIRECTORY;
+    /*
+     * Finally, add our trace to the callback list.
+     */
+    dname = (dname != NULL) ? dname : "";
+    cfg->loc = pstrcat (p, "DIR(", dname, ")", NULL);
+    trace_add (NULL, NULL, cfg, "example_dir_create()");
+    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.
+ */
+static void *example_dir_merge
+	(pool *p, void *parent_conf, void *newloc_conf) {
+
+    example_config
+	    *merged_config =
+		(example_config *) pcalloc (p, sizeof(example_config));
+    example_config
+	    *pconf = (example_config *) parent_conf;
+    example_config
+	    *nconf = (example_config *) newloc_conf;
+    char    *note;
+
+    /*
+     * Some things get copied directly from the more-specific record, rather
+     * than getting merged.
+     */
+    merged_config->local = nconf->local;
+    merged_config->loc = pstrdup (p, nconf->loc);
+    /*
+     * 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.
+     */
+    merged_config->congenital = (pconf->congenital | pconf->local);
+    /*
+     * If we're merging records for two different types of environment (server
+     * and directory), mark the new record appropriately.  Otherwise, inherit
+     * the current value.
+     */
+    merged_config->cmode =
+	(pconf->cmode == nconf->cmode) ? pconf->cmode : CONFIG_MODE_COMBO;
+    /*
+     * Now just record our being called in the trace list.  Include the
+     * locations we were asked to merge.
+     */
+    note = pstrcat
+	    (
+		p,
+		"example_dir_merge(\"",
+		pconf->loc,
+		"\",\"",
+		nconf->loc,
+		"\")",
+		NULL
+	    );
+    trace_add (NULL, NULL, merged_config, note);
+    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.
+ */
+static void *example_server_create
+	(pool *p, server_rec *s) {
+
+    example_config
+	    *cfg;
+    char    *sname = s->server_hostname;
+
+    /*
+     * As with the example_dir_create() reoutine, we allocate and fill in an
+     * empty record.
+     */
+    cfg = (example_config *) pcalloc (p, sizeof(example_config));
+    cfg->local = 0;
+    cfg->congenital = 0;
+    cfg->cmode = CONFIG_MODE_SERVER;
+    /*
+     * Note that we were called in the trace list.
+     */
+    sname = (sname != NULL) ? sname : "";
+    cfg->loc = pstrcat (p, "SVR(", sname, ")", NULL);
+    trace_add (s, NULL, cfg, "example_server_create()");
+    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.
+ */
+static void *example_server_merge
+	(pool *p, void *server1_conf, void *server2_conf) {
+
+    example_config
+	    *merged_config =
+		(example_config *) pcalloc (p, sizeof(example_config));
+    example_config
+	    *s1conf = (example_config *) server1_conf;
+    example_config
+	    *s2conf = (example_config *) server2_conf;
+    char    *note;
+
+    /*
+     * Our inheritance rules are our own, and part of our module's semantics.
+     * Basically, just note whence we came.
+     */
+    merged_config->cmode =
+	(s1conf->cmode == s2conf->cmode) ? s1conf->cmode : CONFIG_MODE_COMBO;
+    merged_config->local = s2conf->local;
+    merged_config->congenital = (s1conf->congenital | s1conf->local);
+    merged_config->loc = pstrdup (p, s2conf->loc);
+    /*
+     * Trace our call, including what we were asked to merge.
+     */
+    note = pstrcat
+	    (
+		p,
+		"example_server_merge(\"",
+		s1conf->loc,
+		"\",\"",
+		s2conf->loc,
+		"\")",
+		NULL
+	    );
+    trace_add (NULL, NULL, merged_config, note);
+    return (void *) merged_config;
+}
+
+/*
+ * 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_xlate
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    /*
+     * We don't actually *do* anything here, except note the fact that we were
+     * called.
+     */
+    trace_add (r->server, r, cfg, "example_xlate()");
+    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_ckuser
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    /*
+     * Don't do anything except log the call.
+     */
+    trace_add (r->server, r, cfg, "example_ckuser()");
+    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_ckauth
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    /*
+     * Log the call and return OK, or access will be denied (even though we
+     * didn't actually do anything).
+     */
+    trace_add (r->server, r, cfg, "example_ckauth()");
+    return OK;
+}
+
+/*
+ * 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_ckaccess
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    trace_add (r->server, r, cfg, "example_ckaccess()");
+    return OK;
+}
+
+/*
+ * This routine is called to determine and/or set the various document type
+ * 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_typer
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    /*
+     * Log the call, but don't do anything else - and report truthfully that
+     * we didn't do anything.
+     */
+    trace_add (r->server, r, cfg, "example_typer()");
+    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
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    /*
+     * Log the call and exit.
+     */
+    trace_add (r->server, r, cfg, "example_fixer()");
+    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) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    trace_add (r->server, r, cfg, "example_logger()");
+    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_hparser
+	(request_rec *r) {
+
+    example_config
+	    *cfg;
+
+    cfg = our_dconfig (r);
+    trace_add (r->server, r, cfg, "example_hparser()");
+    return DECLINED;
+}
+
+/*--------------------------------------------------------------------------*/
+/*									    */
+/* 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.
+ */
+command_rec example_commands[] = {
+    {
+	"Example",			/* directive name */
+	cmd_example,			/* action routine for directive */
+	NULL,				/* argument to include in call */
+	OR_OPTIONS,			/* where available */
+	NO_ARGS,			/* arguments */
+	"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
+ * basis; that is, a handler that is declared for "text/plain" will be
+ * 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.
+ */
+handler_rec example_handlers[] = {
+    { "example-handler", example_handler },
+    { NULL }
+};
+
+/*--------------------------------------------------------------------------*/
+/*									    */
+/* Finally, the list of callback routines and data structures that	    */
+/* provide the 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.
+ *
+ * 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).
+ */
+module example_module = {
+    STANDARD_MODULE_STUFF,
+    example_init,		/* initializer */
+    example_dir_create,		/* per-directory config creater */
+    example_dir_merge,		/* dir config merger - default is to override */
+    example_server_create,	/* server config creator */
+    example_server_merge,	/* server config merger */
+    example_commands,		/* command table */
+    example_handlers,		/* [6] list of handlers */
+    example_xlate,		/* [1] filename-to-URI translation */
+    example_ckuser,		/* [4] check/validate HTTP user_id */
+    example_ckauth,		/* [5] check HTTP user_id is valid *here* */
+    example_ckaccess,		/* [3] check access by host address, etc. */
+    example_typer,		/* [6] MIME type checker/setter */
+    example_fixer,		/* [7] fixups */
+    example_logger,		/* [9] logger */
+    example_hparser		/* [2] header parser */
+};