1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 /*
18 * Apache example module. Provide demonstrations of how modules do things.
19 * It is not meant to be used in a production server. Since it participates
20 * in all of the processing phases, it could conceivable interfere with
21 * the proper operation of other modules -- particularly the ones related
22 * to security.
23 *
24 * In the interest of brevity, all functions and structures internal to
25 * this module, but which may have counterparts in *real* modules, are
26 * prefixed with 'x_' instead of 'example_'.
27 *
28 * To use mod_example_hooks, configure the Apache build with
29 * --enable-example and compile. Set up a <Location> block in your
30 * configuration file like so:
31 *
32 * <Location /example>
33 * SetHandler example-hooks-handler
34 * </Location>
35 *
36 * When you look at that location on your server, you will see a backtrace of
37 * the callbacks that have been invoked up to that point. See the ErrorLog for
38 * more information on code paths that touch mod_example_hooks.
39 *
40 * IMPORTANT NOTES
41 * ===============
42 *
43 * Do NOT use this module on a production server. It attaches itself to every
44 * phase of the server runtime operations including startup, shutdown and
45 * request processing, and produces copious amounts of logging data. This will
46 * negatively affect server performance.
47 *
48 * Do NOT use mod_example_hooks as the basis for your own code. This module
49 * implements every callback hook offered by the Apache core, and your
50 * module will almost certainly not have to implement this much. If you
51 * want a simple module skeleton to start development, use apxs -g.
52 *
53 * XXX TO DO XXX
54 * =============
55 *
56 * * Enable HTML backtrace entries for more callbacks that are not directly
57 * associated with a request
58 * * Make sure every callback that posts an HTML backtrace entry does so in the * right category, so nothing gets overwritten
59 * * Implement some logic to show what happens in the parent, and what in the
60 * child(ren)
61 */
62
63 #include "httpd.h"
64 #include "http_config.h"
65 #include "http_core.h"
66 #include "http_log.h"
67 #include "http_main.h"
68 #include "http_protocol.h"
69 #include "http_request.h"
70 #include "util_script.h"
71 #include "http_connection.h"
72 #ifdef HAVE_UNIX_SUEXEC
73 #include "unixd.h"
74 #endif
75 #include "scoreboard.h"
76 #include "mpm_common.h"
77
78 #include "apr_strings.h"
79
80 #include <stdio.h>
81
82 /*--------------------------------------------------------------------------*/
83 /* */
84 /* Data declarations. */
85 /* */
86 /* Here are the static cells and structure declarations private to our */
87 /* module. */
88 /* */
89 /*--------------------------------------------------------------------------*/
90
91 /*
92 * Sample configuration record. Used for both per-directory and per-server
93 * configuration data.
94 *
95 * It's perfectly reasonable to have two different structures for the two
96 * different environments. The same command handlers will be called for
97 * both, though, so the handlers need to be able to tell them apart. One
98 * possibility is for both structures to start with an int which is 0 for
99 * one and 1 for the other.
100 *
101 * Note that while the per-directory and per-server configuration records are
102 * available to most of the module handlers, they should be treated as
103 * READ-ONLY by all except the command and merge handlers. Sometimes handlers
104 * are handed a record that applies to the current location by implication or
105 * inheritance, and modifying it will change the rules for other locations.
106 */
107 typedef struct x_cfg {
108 int cmode; /* Environment to which record applies
109 * (directory, server, or combination).
110 */
111 #define CONFIG_MODE_SERVER 1
112 #define CONFIG_MODE_DIRECTORY 2
113 #define CONFIG_MODE_COMBO 3 /* Shouldn't ever happen. */
114 int local; /* Boolean: "Example" directive declared
115 * here?
116 */
117 int congenital; /* Boolean: did we inherit an "Example"? */
118 char *trace; /* Pointer to trace string. */
119 char *loc; /* Location to which this record applies. */
120 } x_cfg;
121
122 /*
123 * String pointer to hold the startup trace. No harm working with a global until
124 * the server is (may be) multi-threaded.
125 */
126 static const char *trace = NULL;
127
128 /*
129 * Declare ourselves so the configuration routines can find and know us.
130 * We'll fill it in at the end of the module.
131 */
132 module AP_MODULE_DECLARE_DATA example_hooks_module;
133
134 /*--------------------------------------------------------------------------*/
135 /* */
136 /* The following pseudo-prototype declarations illustrate the parameters */
137 /* passed to command handlers for the different types of directive */
138 /* syntax. If an argument was specified in the directive definition */
139 /* (look for "command_rec" below), it's available to the command handler */
140 /* via the (void *) info field in the cmd_parms argument passed to the */
141 /* handler (cmd->info for the examples below). */
142 /* */
143 /*--------------------------------------------------------------------------*/
144
145 /*
146 * Command handler for a NO_ARGS directive. Declared in the command_rec
147 * list with
148 * AP_INIT_NO_ARGS("directive", function, mconfig, where, help)
149 *
150 * static const char *handle_NO_ARGS(cmd_parms *cmd, void *mconfig);
151 */
152
153 /*
154 * Command handler for a RAW_ARGS directive. The "args" argument is the text
155 * of the commandline following the directive itself. Declared in the
156 * command_rec list with
157 * AP_INIT_RAW_ARGS("directive", function, mconfig, where, help)
158 *
159 * static const char *handle_RAW_ARGS(cmd_parms *cmd, void *mconfig,
160 * const char *args);
161 */
162
163 /*
164 * Command handler for a FLAG directive. The single parameter is passed in
165 * "bool", which is either zero or not for Off or On respectively.
166 * Declared in the command_rec list with
167 * AP_INIT_FLAG("directive", function, mconfig, where, help)
168 *
169 * static const char *handle_FLAG(cmd_parms *cmd, void *mconfig, int bool);
170 */
171
172 /*
173 * Command handler for a TAKE1 directive. The single parameter is passed in
174 * "word1". Declared in the command_rec list with
175 * AP_INIT_TAKE1("directive", function, mconfig, where, help)
176 *
177 * static const char *handle_TAKE1(cmd_parms *cmd, void *mconfig,
178 * char *word1);
179 */
180
181 /*
182 * Command handler for a TAKE2 directive. TAKE2 commands must always have
183 * exactly two arguments. Declared in the command_rec list with
184 * AP_INIT_TAKE2("directive", function, mconfig, where, help)
185 *
186 * static const char *handle_TAKE2(cmd_parms *cmd, void *mconfig,
187 * char *word1, char *word2);
188 */
189
190 /*
191 * Command handler for a TAKE3 directive. Like TAKE2, these must have exactly
192 * three arguments, or the parser complains and doesn't bother calling us.
193 * Declared in the command_rec list with
194 * AP_INIT_TAKE3("directive", function, mconfig, where, help)
195 *
196 * static const char *handle_TAKE3(cmd_parms *cmd, void *mconfig,
197 * char *word1, char *word2, char *word3);
198 */
199
200 /*
201 * Command handler for a TAKE12 directive. These can take either one or two
202 * arguments.
203 * - word2 is a NULL pointer if no second argument was specified.
204 * Declared in the command_rec list with
205 * AP_INIT_TAKE12("directive", function, mconfig, where, help)
206 *
207 * static const char *handle_TAKE12(cmd_parms *cmd, void *mconfig,
208 * char *word1, char *word2);
209 */
210
211 /*
212 * Command handler for a TAKE123 directive. A TAKE123 directive can be given,
213 * as might be expected, one, two, or three arguments.
214 * - word2 is a NULL pointer if no second argument was specified.
215 * - word3 is a NULL pointer if no third argument was specified.
216 * Declared in the command_rec list with
217 * AP_INIT_TAKE123("directive", function, mconfig, where, help)
218 *
219 * static const char *handle_TAKE123(cmd_parms *cmd, void *mconfig,
220 * char *word1, char *word2, char *word3);
221 */
222
223 /*
224 * Command handler for a TAKE13 directive. Either one or three arguments are
225 * permitted - no two-parameters-only syntax is allowed.
226 * - word2 and word3 are NULL pointers if only one argument was specified.
227 * Declared in the command_rec list with
228 * AP_INIT_TAKE13("directive", function, mconfig, where, help)
229 *
230 * static const char *handle_TAKE13(cmd_parms *cmd, void *mconfig,
231 * char *word1, char *word2, char *word3);
232 */
233
234 /*
235 * Command handler for a TAKE23 directive. At least two and as many as three
236 * arguments must be specified.
237 * - word3 is a NULL pointer if no third argument was specified.
238 * Declared in the command_rec list with
239 * AP_INIT_TAKE23("directive", function, mconfig, where, help)
240 *
241 * static const char *handle_TAKE23(cmd_parms *cmd, void *mconfig,
242 * char *word1, char *word2, char *word3);
243 */
244
245 /*
246 * Command handler for a ITERATE directive.
247 * - Handler is called once for each of n arguments given to the directive.
248 * - word1 points to each argument in turn.
249 * Declared in the command_rec list with
250 * AP_INIT_ITERATE("directive", function, mconfig, where, help)
251 *
252 * static const char *handle_ITERATE(cmd_parms *cmd, void *mconfig,
253 * char *word1);
254 */
255
256 /*
257 * Command handler for a ITERATE2 directive.
258 * - Handler is called once for each of the second and subsequent arguments
259 * given to the directive.
260 * - word1 is the same for each call for a particular directive instance (the
261 * first argument).
262 * - word2 points to each of the second and subsequent arguments in turn.
263 * Declared in the command_rec list with
264 * AP_INIT_ITERATE2("directive", function, mconfig, where, help)
265 *
266 * static const char *handle_ITERATE2(cmd_parms *cmd, void *mconfig,
267 * char *word1, char *word2);
268 */
269
270 /*--------------------------------------------------------------------------*/
271 /* */
272 /* These routines are strictly internal to this module, and support its */
273 /* operation. They are not referenced by any external portion of the */
274 /* server. */
275 /* */
276 /*--------------------------------------------------------------------------*/
277
278 /*
279 * Locate our directory configuration record for the current request.
280 */
our_dconfig(const request_rec * r)281 static x_cfg *our_dconfig(const request_rec *r)
282 {
283 return (x_cfg *) ap_get_module_config(r->per_dir_config, &example_hooks_module);
284 }
285
286 /*
287 * The following utility routines are not used in the module. Don't
288 * compile them so -Wall doesn't complain about functions that are
289 * defined but not used.
290 */
291 #if 0
292 /*
293 * Locate our server configuration record for the specified server.
294 */
295 static x_cfg *our_sconfig(const server_rec *s)
296 {
297 return (x_cfg *) ap_get_module_config(s->module_config, &example_hooks_module);
298 }
299
300 /*
301 * Likewise for our configuration record for the specified request.
302 */
303 static x_cfg *our_rconfig(const request_rec *r)
304 {
305 return (x_cfg *) ap_get_module_config(r->request_config, &example_hooks_module);
306 }
307 #endif /* if 0 */
308
309 /*
310 * Likewise for our configuration record for a connection.
311 */
our_cconfig(const conn_rec * c)312 static x_cfg *our_cconfig(const conn_rec *c)
313 {
314 return (x_cfg *) ap_get_module_config(c->conn_config, &example_hooks_module);
315 }
316
317 /*
318 * You *could* change the following if you wanted to see the calling
319 * sequence reported in the server's error_log, but beware - almost all of
320 * these co-routines are called for every single request, and the impact
321 * on the size (and readability) of the error_log is considerable.
322 */
323 #ifndef EXAMPLE_LOG_EACH
324 #define EXAMPLE_LOG_EACH 0
325 #endif
326
327 #if EXAMPLE_LOG_EACH
example_log_each(apr_pool_t * p,server_rec * s,const char * note)328 static void example_log_each(apr_pool_t *p, server_rec *s, const char *note)
329 {
330 if (s != NULL) {
331 ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, "mod_example: %s", note);
332 } else {
333 apr_file_t *out = NULL;
334 apr_file_open_stderr(&out, p);
335 apr_file_printf(out, "mod_example traced in non-loggable "
336 "context: %s\n", note);
337 }
338 }
339 #endif
340
341 /*
342 * This utility routine traces the hooks called when the server starts up.
343 * It leaves a trace in a global variable, so it should not be called from
344 * a hook handler that runs in a multi-threaded situation.
345 */
346
trace_startup(apr_pool_t * p,server_rec * s,x_cfg * mconfig,const char * note)347 static void trace_startup(apr_pool_t *p, server_rec *s, x_cfg *mconfig,
348 const char *note)
349 {
350 const char *sofar;
351 char *where, *addon;
352
353 #if EXAMPLE_LOG_EACH
354 example_log_each(p, s, note);
355 #endif
356
357 /*
358 * If we weren't passed a configuration record, we can't figure out to
359 * what location this call applies. This only happens for co-routines
360 * that don't operate in a particular directory or server context. If we
361 * got a valid record, extract the location (directory or server) to which
362 * it applies.
363 */
364 where = (mconfig != NULL) ? mconfig->loc : "nowhere";
365 where = (where != NULL) ? where : "";
366
367 addon = apr_pstrcat(p,
368 " <li>\n"
369 " <dl>\n"
370 " <dt><samp>", note, "</samp></dt>\n"
371 " <dd><samp>[", where, "]</samp></dd>\n"
372 " </dl>\n"
373 " </li>\n",
374 NULL);
375
376 /*
377 * Make sure that we start with a valid string, even if we have never been
378 * called.
379 */
380 sofar = (trace == NULL) ? "" : trace;
381
382 trace = apr_pstrcat(p, sofar, addon, NULL);
383 }
384
385
386 /*
387 * This utility route traces the hooks called as a request is handled.
388 * It takes the current request as argument
389 */
390 #define TRACE_NOTE "example-hooks-trace"
391
trace_request(const request_rec * r,const char * note)392 static void trace_request(const request_rec *r, const char *note)
393 {
394 const char *trace_copy, *sofar;
395 char *addon, *where;
396 x_cfg *cfg;
397
398 #if EXAMPLE_LOG_EACH
399 example_log_each(r->pool, r->server, note);
400 #endif
401
402 if ((sofar = apr_table_get(r->notes, TRACE_NOTE)) == NULL) {
403 sofar = "";
404 }
405
406 cfg = our_dconfig(r);
407
408 where = (cfg != NULL) ? cfg->loc : "nowhere";
409 where = (where != NULL) ? where : "";
410
411 addon = apr_pstrcat(r->pool,
412 " <li>\n"
413 " <dl>\n"
414 " <dt><samp>", note, "</samp></dt>\n"
415 " <dd><samp>[", where, "]</samp></dd>\n"
416 " </dl>\n"
417 " </li>\n",
418 NULL);
419
420 trace_copy = apr_pstrcat(r->pool, sofar, addon, NULL);
421 apr_table_set(r->notes, TRACE_NOTE, trace_copy);
422 }
423
424 /*
425 * This utility routine traces the hooks called while processing a
426 * Connection. Its trace is kept in the pool notes of the pool associated
427 * with the Connection.
428 */
429
430 /*
431 * Key to get and set the userdata. We should be able to get away
432 * with a constant key, since in prefork mode the process will have
433 * the connection and its pool to itself entirely, and in
434 * multi-threaded mode each connection will have its own pool.
435 */
436 #define CONN_NOTE "example-hooks-connection"
437
trace_connection(conn_rec * c,const char * note)438 static void trace_connection(conn_rec *c, const char *note)
439 {
440 const char *trace_copy, *sofar;
441 char *addon, *where;
442 void *data;
443 x_cfg *cfg;
444
445 #if EXAMPLE_LOG_EACH
446 example_log_each(c->pool, c->base_server, note);
447 #endif
448
449 cfg = our_cconfig(c);
450
451 where = (cfg != NULL) ? cfg->loc : "nowhere";
452 where = (where != NULL) ? where : "";
453
454 addon = apr_pstrcat(c->pool,
455 " <li>\n"
456 " <dl>\n"
457 " <dt><samp>", note, "</samp></dt>\n"
458 " <dd><samp>[", where, "]</samp></dd>\n"
459 " </dl>\n"
460 " </li>\n",
461 NULL);
462
463 /* Find existing notes and copy */
464 apr_pool_userdata_get(&data, CONN_NOTE, c->pool);
465 sofar = (data == NULL) ? "" : (const char *) data;
466
467 /* Tack addon onto copy */
468 trace_copy = apr_pstrcat(c->pool, sofar, addon, NULL);
469
470 /*
471 * Stash copy back into pool notes. This call has a cleanup
472 * parameter, but we're not using it because the string has been
473 * allocated from that same pool. There is also an unused return
474 * value: we have nowhere to communicate any error that might
475 * occur, and will have to check for the existence of this data on
476 * the other end.
477 */
478 apr_pool_userdata_set((const void *) trace_copy, CONN_NOTE,
479 NULL, c->pool);
480 }
481
trace_nocontext(apr_pool_t * p,const char * file,int line,const char * note)482 static void trace_nocontext(apr_pool_t *p, const char *file, int line,
483 const char *note)
484 {
485 /*
486 * Since we have no request or connection to trace, or any idea
487 * from where this routine was called, there's really not much we
488 * can do. If we are not logging everything by way of the
489 * EXAMPLE_LOG_EACH constant, do nothing in this routine.
490 */
491
492 #ifdef EXAMPLE_LOG_EACH
493 ap_log_perror(file, line, APLOG_MODULE_INDEX, APLOG_NOTICE, 0, p, "%s", note);
494 #endif
495 }
496
497
498 /*--------------------------------------------------------------------------*/
499 /* We prototyped the various syntax for command handlers (routines that */
500 /* are called when the configuration parser detects a directive declared */
501 /* by our module) earlier. Now we actually declare a "real" routine that */
502 /* will be invoked by the parser when our "real" directive is */
503 /* encountered. */
504 /* */
505 /* If a command handler encounters a problem processing the directive, it */
506 /* signals this fact by returning a non-NULL pointer to a string */
507 /* describing the problem. */
508 /* */
509 /* The magic return value DECLINE_CMD is used to deal with directives */
510 /* that might be declared by multiple modules. If the command handler */
511 /* returns NULL, the directive was processed; if it returns DECLINE_CMD, */
512 /* the next module (if any) that declares the directive is given a chance */
513 /* at it. If it returns any other value, it's treated as the text of an */
514 /* error message. */
515 /*--------------------------------------------------------------------------*/
516 /*
517 * Command handler for the NO_ARGS "Example" directive. All we do is mark the
518 * call in the trace log, and flag the applicability of the directive to the
519 * current location in that location's configuration record.
520 */
cmd_example(cmd_parms * cmd,void * mconfig)521 static const char *cmd_example(cmd_parms *cmd, void *mconfig)
522 {
523 x_cfg *cfg = (x_cfg *) mconfig;
524
525 /*
526 * "Example Wuz Here"
527 */
528 cfg->local = 1;
529 trace_startup(cmd->pool, cmd->server, cfg, "cmd_example()");
530 return NULL;
531 }
532
533 /*
534 * This function gets called to create a per-directory configuration
535 * record. This will be called for the "default" server environment, and for
536 * each directory for which the parser finds any of our directives applicable.
537 * If a directory doesn't have any of our directives involved (i.e., they
538 * aren't in the .htaccess file, or a <Location>, <Directory>, or related
539 * block), this routine will *not* be called - the configuration for the
540 * closest ancestor is used.
541 *
542 * The return value is a pointer to the created module-specific
543 * structure.
544 */
x_create_dir_config(apr_pool_t * p,char * dirspec)545 static void *x_create_dir_config(apr_pool_t *p, char *dirspec)
546 {
547 x_cfg *cfg;
548 char *dname = dirspec;
549 char *note;
550
551 /*
552 * Allocate the space for our record from the pool supplied.
553 */
554 cfg = (x_cfg *) apr_pcalloc(p, sizeof(x_cfg));
555 /*
556 * Now fill in the defaults. If there are any `parent' configuration
557 * records, they'll get merged as part of a separate callback.
558 */
559 cfg->local = 0;
560 cfg->congenital = 0;
561 cfg->cmode = CONFIG_MODE_DIRECTORY;
562 /*
563 * Finally, add our trace to the callback list.
564 */
565 dname = (dname != NULL) ? dname : "";
566 cfg->loc = apr_pstrcat(p, "DIR(", dname, ")", NULL);
567 note = apr_psprintf(p, "x_create_dir_config(p == %pp, dirspec == %s)",
568 (void*) p, dirspec);
569 trace_startup(p, NULL, cfg, note);
570 return (void *) cfg;
571 }
572
573 /*
574 * This function gets called to merge two per-directory configuration
575 * records. This is typically done to cope with things like .htaccess files
576 * or <Location> directives for directories that are beneath one for which a
577 * configuration record was already created. The routine has the
578 * responsibility of creating a new record and merging the contents of the
579 * other two into it appropriately. If the module doesn't declare a merge
580 * routine, the record for the closest ancestor location (that has one) is
581 * used exclusively.
582 *
583 * The routine MUST NOT modify any of its arguments!
584 *
585 * The return value is a pointer to the created module-specific structure
586 * containing the merged values.
587 */
x_merge_dir_config(apr_pool_t * p,void * parent_conf,void * newloc_conf)588 static void *x_merge_dir_config(apr_pool_t *p, void *parent_conf,
589 void *newloc_conf)
590 {
591
592 x_cfg *merged_config = (x_cfg *) apr_pcalloc(p, sizeof(x_cfg));
593 x_cfg *pconf = (x_cfg *) parent_conf;
594 x_cfg *nconf = (x_cfg *) newloc_conf;
595 char *note;
596
597 /*
598 * Some things get copied directly from the more-specific record, rather
599 * than getting merged.
600 */
601 merged_config->local = nconf->local;
602 merged_config->loc = apr_pstrdup(p, nconf->loc);
603 /*
604 * Others, like the setting of the `congenital' flag, get ORed in. The
605 * setting of that particular flag, for instance, is TRUE if it was ever
606 * true anywhere in the upstream configuration.
607 */
608 merged_config->congenital = (pconf->congenital | pconf->local);
609 /*
610 * If we're merging records for two different types of environment (server
611 * and directory), mark the new record appropriately. Otherwise, inherit
612 * the current value.
613 */
614 merged_config->cmode =
615 (pconf->cmode == nconf->cmode) ? pconf->cmode : CONFIG_MODE_COMBO;
616 /*
617 * Now just record our being called in the trace list. Include the
618 * locations we were asked to merge.
619 */
620 note = apr_psprintf(p, "x_merge_dir_config(p == %pp, parent_conf == "
621 "%pp, newloc_conf == %pp)", (void*) p,
622 (void*) parent_conf, (void*) newloc_conf);
623 trace_startup(p, NULL, merged_config, note);
624 return (void *) merged_config;
625 }
626
627 /*
628 * This function gets called to create a per-server configuration
629 * record. It will always be called for the "default" server.
630 *
631 * The return value is a pointer to the created module-specific
632 * structure.
633 */
x_create_server_config(apr_pool_t * p,server_rec * s)634 static void *x_create_server_config(apr_pool_t *p, server_rec *s)
635 {
636
637 x_cfg *cfg;
638 char *sname = s->server_hostname;
639
640 /*
641 * As with the x_create_dir_config() reoutine, we allocate and fill
642 * in an empty record.
643 */
644 cfg = (x_cfg *) apr_pcalloc(p, sizeof(x_cfg));
645 cfg->local = 0;
646 cfg->congenital = 0;
647 cfg->cmode = CONFIG_MODE_SERVER;
648 /*
649 * Note that we were called in the trace list.
650 */
651 sname = (sname != NULL) ? sname : "";
652 cfg->loc = apr_pstrcat(p, "SVR(", sname, ")", NULL);
653 trace_startup(p, s, cfg, "x_create_server_config()");
654 return (void *) cfg;
655 }
656
657 /*
658 * This function gets called to merge two per-server configuration
659 * records. This is typically done to cope with things like virtual hosts and
660 * the default server configuration The routine has the responsibility of
661 * creating a new record and merging the contents of the other two into it
662 * appropriately. If the module doesn't declare a merge routine, the more
663 * specific existing record is used exclusively.
664 *
665 * The routine MUST NOT modify any of its arguments!
666 *
667 * The return value is a pointer to the created module-specific structure
668 * containing the merged values.
669 */
x_merge_server_config(apr_pool_t * p,void * server1_conf,void * server2_conf)670 static void *x_merge_server_config(apr_pool_t *p, void *server1_conf,
671 void *server2_conf)
672 {
673
674 x_cfg *merged_config = (x_cfg *) apr_pcalloc(p, sizeof(x_cfg));
675 x_cfg *s1conf = (x_cfg *) server1_conf;
676 x_cfg *s2conf = (x_cfg *) server2_conf;
677 char *note;
678
679 /*
680 * Our inheritance rules are our own, and part of our module's semantics.
681 * Basically, just note whence we came.
682 */
683 merged_config->cmode =
684 (s1conf->cmode == s2conf->cmode) ? s1conf->cmode : CONFIG_MODE_COMBO;
685 merged_config->local = s2conf->local;
686 merged_config->congenital = (s1conf->congenital | s1conf->local);
687 merged_config->loc = apr_pstrdup(p, s2conf->loc);
688 /*
689 * Trace our call, including what we were asked to merge.
690 */
691 note = apr_pstrcat(p, "x_merge_server_config(\"", s1conf->loc, "\",\"",
692 s2conf->loc, "\")", NULL);
693 trace_startup(p, NULL, merged_config, note);
694 return (void *) merged_config;
695 }
696
697
698 /*--------------------------------------------------------------------------*
699 * *
700 * Now let's declare routines for each of the callback hooks in order. *
701 * (That's the order in which they're listed in the callback list, *not *
702 * the order in which the server calls them! See the command_rec *
703 * declaration near the bottom of this file.) Note that these may be *
704 * called for situations that don't relate primarily to our function - in *
705 * other words, the fixup handler shouldn't assume that the request has *
706 * to do with "example" stuff. *
707 * *
708 * With the exception of the content handler, all of our routines will be *
709 * called for each request, unless an earlier handler from another module *
710 * aborted the sequence. *
711 * *
712 * There are three types of hooks (see include/ap_config.h): *
713 * *
714 * VOID : No return code, run all handlers declared by any module *
715 * RUN_FIRST : Run all handlers until one returns something other *
716 * than DECLINED. Hook runner result is result of last callback *
717 * RUN_ALL : Run all handlers until one returns something other than OK *
718 * or DECLINED. The hook runner returns that other value. If *
719 * all hooks run, the hook runner returns OK. *
720 * *
721 * Handlers that are declared as "int" can return the following: *
722 * *
723 * OK Handler accepted the request and did its thing with it. *
724 * DECLINED Handler took no action. *
725 * HTTP_mumble Handler looked at request and found it wanting. *
726 * *
727 * See include/httpd.h for a list of HTTP_mumble status codes. Handlers *
728 * that are not declared as int return a valid pointer, or NULL if they *
729 * DECLINE to handle their phase for that specific request. Exceptions, if *
730 * any, are noted with each routine. *
731 *--------------------------------------------------------------------------*/
732
733 /*
734 * This routine is called before the server processes the configuration
735 * files. There is no return value.
736 */
x_pre_config(apr_pool_t * pconf,apr_pool_t * plog,apr_pool_t * ptemp)737 static int x_pre_config(apr_pool_t *pconf, apr_pool_t *plog,
738 apr_pool_t *ptemp)
739 {
740 /*
741 * Log the call and exit.
742 */
743 trace_startup(ptemp, NULL, NULL, "x_pre_config()");
744
745 return OK;
746 }
747
748 /*
749 * This routine is called after the server processes the configuration
750 * files. At this point the module may review and adjust its configuration
751 * settings in relation to one another and report any problems. On restart,
752 * this routine will be called twice, once in the startup process (which
753 * exits shortly after this phase) and once in the running server process.
754 *
755 * The return value is OK, DECLINED, or HTTP_mumble. If we return OK, the
756 * server will still call any remaining modules with an handler for this
757 * phase.
758 */
x_check_config(apr_pool_t * pconf,apr_pool_t * plog,apr_pool_t * ptemp,server_rec * s)759 static int x_check_config(apr_pool_t *pconf, apr_pool_t *plog,
760 apr_pool_t *ptemp, server_rec *s)
761 {
762 /*
763 * Log the call and exit.
764 */
765 trace_startup(ptemp, s, NULL, "x_check_config()");
766 return OK;
767 }
768
769 /*
770 * This routine is called when the -t command-line option is supplied.
771 * It executes only once, in the startup process, after the check_config
772 * phase and just before the process exits. At this point the module
773 * may output any information useful in configuration testing.
774 *
775 * This is a VOID hook: all defined handlers get called.
776 */
x_test_config(apr_pool_t * pconf,server_rec * s)777 static void x_test_config(apr_pool_t *pconf, server_rec *s)
778 {
779 apr_file_t *out = NULL;
780
781 apr_file_open_stderr(&out, pconf);
782
783 apr_file_printf(out, "Example module configuration test routine\n");
784
785 trace_startup(pconf, s, NULL, "x_test_config()");
786 }
787
788 /*
789 * This routine is called to perform any module-specific log file
790 * openings. It is invoked just before the post_config phase
791 *
792 * The return value is OK, DECLINED, or HTTP_mumble. If we return OK, the
793 * server will still call any remaining modules with an handler for this
794 * phase.
795 */
x_open_logs(apr_pool_t * pconf,apr_pool_t * plog,apr_pool_t * ptemp,server_rec * s)796 static int x_open_logs(apr_pool_t *pconf, apr_pool_t *plog,
797 apr_pool_t *ptemp, server_rec *s)
798 {
799 /*
800 * Log the call and exit.
801 */
802 trace_startup(ptemp, s, NULL, "x_open_logs()");
803 return OK;
804 }
805
806 /*
807 * This routine is called after the server finishes the configuration
808 * process. At this point the module may review and adjust its configuration
809 * settings in relation to one another and report any problems. On restart,
810 * this routine will be called only once, in the running server process.
811 *
812 * The return value is OK, DECLINED, or HTTP_mumble. If we return OK, the
813 * server will still call any remaining modules with an handler for this
814 * phase.
815 */
x_post_config(apr_pool_t * pconf,apr_pool_t * plog,apr_pool_t * ptemp,server_rec * s)816 static int x_post_config(apr_pool_t *pconf, apr_pool_t *plog,
817 apr_pool_t *ptemp, server_rec *s)
818 {
819 /*
820 * Log the call and exit.
821 */
822 trace_startup(ptemp, s, NULL, "x_post_config()");
823 return OK;
824 }
825
826 /*
827 * All our process-death routine does is add its trace to the log.
828 */
x_child_exit(void * data)829 static apr_status_t x_child_exit(void *data)
830 {
831 char *note;
832 server_rec *s = data;
833 char *sname = s->server_hostname;
834
835 /*
836 * The arbitrary text we add to our trace entry indicates for which server
837 * we're being called.
838 */
839 sname = (sname != NULL) ? sname : "";
840 note = apr_pstrcat(s->process->pool, "x_child_exit(", sname, ")", NULL);
841 trace_startup(s->process->pool, s, NULL, note);
842 return APR_SUCCESS;
843 }
844
845 /*
846 * All our process initialiser does is add its trace to the log.
847 *
848 * This is a VOID hook: all defined handlers get called.
849 */
x_child_init(apr_pool_t * p,server_rec * s)850 static void x_child_init(apr_pool_t *p, server_rec *s)
851 {
852 char *note;
853 char *sname = s->server_hostname;
854
855 /*
856 * The arbitrary text we add to our trace entry indicates for which server
857 * we're being called.
858 */
859 sname = (sname != NULL) ? sname : "";
860 note = apr_pstrcat(p, "x_child_init(", sname, ")", NULL);
861 trace_startup(p, s, NULL, note);
862
863 apr_pool_cleanup_register(p, s, x_child_exit, x_child_exit);
864 }
865
866 /*
867 * The hook runner for ap_hook_http_scheme is aliased to ap_http_scheme(),
868 * a routine that the core and other modules call when they need to know
869 * the URL scheme for the request. For instance, mod_ssl returns "https"
870 * if the server_rec associated with the request has SSL enabled.
871 *
872 * This hook was named 'ap_hook_http_method' in httpd 2.0.
873 *
874 * This is a RUN_FIRST hook: the first handler to return a non NULL
875 * value aborts the handler chain. The http_core module inserts a
876 * fallback handler (with APR_HOOK_REALLY_LAST preference) that returns
877 * "http".
878 */
x_http_scheme(const request_rec * r)879 static const char *x_http_scheme(const request_rec *r)
880 {
881 /*
882 * Log the call and exit.
883 */
884 trace_request(r, "x_http_scheme()");
885
886 /* We have no claims to make about the request scheme */
887 return NULL;
888 }
889
890 /*
891 * The runner for this hook is aliased to ap_default_port(), which the
892 * core and other modules call when they need to know the default port
893 * for a particular server. This is used for instance to omit the
894 * port number from a Redirect response Location header URL if the port
895 * number is equal to the default port for the service (like 80 for http).
896 *
897 * This is a RUN_FIRST hook: the first handler to return a non-zero
898 * value is the last one executed. The http_core module inserts a
899 * fallback handler (with APR_HOOK_REALLY_LAST order specifier) that
900 * returns 80.
901 */
x_default_port(const request_rec * r)902 static apr_port_t x_default_port(const request_rec *r)
903 {
904 /*
905 * Log the call and exit.
906 */
907 trace_request(r, "x_default_port()");
908 return 0;
909 }
910
911 /*
912 * This routine is called just before the handler gets invoked. It allows
913 * a module to insert a previously defined filter into the filter chain.
914 *
915 * No filter has been defined by this module, so we just log the call
916 * and exit.
917 *
918 * This is a VOID hook: all defined handlers get called.
919 */
x_insert_filter(request_rec * r)920 static void x_insert_filter(request_rec *r)
921 {
922 /*
923 * Log the call and exit.
924 */
925 trace_request(r, "x_insert_filter()");
926 }
927
928 /*
929 * This routine is called to insert a previously defined error filter into
930 * the filter chain as the request is being processed.
931 *
932 * For the purpose of this example, we don't have a filter to insert,
933 * so just add to the trace and exit.
934 *
935 * This is a VOID hook: all defined handlers get called.
936 */
x_insert_error_filter(request_rec * r)937 static void x_insert_error_filter(request_rec *r)
938 {
939 trace_request(r, "x_insert_error_filter()");
940 }
941
942 /*--------------------------------------------------------------------------*/
943 /* */
944 /* Now we declare our content handlers, which are invoked when the server */
945 /* encounters a document which our module is supposed to have a chance to */
946 /* see. (See mod_mime's SetHandler and AddHandler directives, and the */
947 /* mod_info and mod_status examples, for more details.) */
948 /* */
949 /* Since content handlers are dumping data directly into the connection */
950 /* (using the r*() routines, such as rputs() and rprintf()) without */
951 /* intervention by other parts of the server, they need to make */
952 /* sure any accumulated HTTP headers are sent first. This is done by */
953 /* calling send_http_header(). Otherwise, no header will be sent at all, */
954 /* and the output sent to the client will actually be HTTP-uncompliant. */
955 /*--------------------------------------------------------------------------*/
956 /*
957 * Sample content handler. All this does is display the call list that has
958 * been built up so far.
959 *
960 * This routine gets called for every request, unless another handler earlier
961 * in the callback chain has already handled the request. It is up to us to
962 * test the request_rec->handler field and see whether we are meant to handle
963 * this request.
964 *
965 * The content handler gets to write directly to the client using calls like
966 * ap_rputs() and ap_rprintf()
967 *
968 * This is a RUN_FIRST hook.
969 */
x_handler(request_rec * r)970 static int x_handler(request_rec *r)
971 {
972 x_cfg *dcfg;
973 char *note;
974 void *conn_data;
975 apr_status_t status;
976
977 dcfg = our_dconfig(r);
978 /*
979 * Add our trace to the log, and whether we get to write
980 * content for this request.
981 */
982 note = apr_pstrcat(r->pool, "x_handler(), handler is \"",
983 r->handler, "\"", NULL);
984 trace_request(r, note);
985
986 /* If it's not for us, get out as soon as possible. */
987 if (strcmp(r->handler, "example-hooks-handler")) {
988 return DECLINED;
989 }
990
991 /*
992 * Set the Content-type header. Note that we do not actually have to send
993 * the headers: this is done by the http core.
994 */
995 ap_set_content_type(r, "text/html");
996 /*
997 * If we're only supposed to send header information (HEAD request), we're
998 * already there.
999 */
1000 if (r->header_only) {
1001 return OK;
1002 }
1003
1004 /*
1005 * Now send our actual output. Since we tagged this as being
1006 * "text/html", we need to embed any HTML.
1007 */
1008 ap_rputs(DOCTYPE_HTML_3_2, r);
1009 ap_rputs("<HTML>\n", r);
1010 ap_rputs(" <HEAD>\n", r);
1011 ap_rputs(" <TITLE>mod_example_hooks Module Content-Handler Output\n", r);
1012 ap_rputs(" </TITLE>\n", r);
1013 ap_rputs(" </HEAD>\n", r);
1014 ap_rputs(" <BODY>\n", r);
1015 ap_rputs(" <H1><SAMP>mod_example_hooks</SAMP> Module Content-Handler Output\n", r);
1016 ap_rputs(" </H1>\n", r);
1017 ap_rputs(" <P>\n", r);
1018 ap_rprintf(r, " Apache HTTP Server version: \"%s\"\n",
1019 ap_get_server_banner());
1020 ap_rputs(" <BR>\n", r);
1021 ap_rprintf(r, " Server built: \"%s\"\n", ap_get_server_built());
1022 ap_rputs(" </P>\n", r);
1023 ap_rputs(" <P>\n", r);
1024 ap_rputs(" The format for the callback trace is:\n", r);
1025 ap_rputs(" </P>\n", r);
1026 ap_rputs(" <DL>\n", r);
1027 ap_rputs(" <DT><EM>n</EM>.<SAMP><routine-name>", r);
1028 ap_rputs("(<routine-data>)</SAMP>\n", r);
1029 ap_rputs(" </DT>\n", r);
1030 ap_rputs(" <DD><SAMP>[<applies-to>]</SAMP>\n", r);
1031 ap_rputs(" </DD>\n", r);
1032 ap_rputs(" </DL>\n", r);
1033 ap_rputs(" <P>\n", r);
1034 ap_rputs(" The <SAMP><routine-data></SAMP> is supplied by\n", r);
1035 ap_rputs(" the routine when it requests the trace,\n", r);
1036 ap_rputs(" and the <SAMP><applies-to></SAMP> is extracted\n", r);
1037 ap_rputs(" from the configuration record at the time of the trace.\n", r);
1038 ap_rputs(" <STRONG>SVR()</STRONG> indicates a server environment\n", r);
1039 ap_rputs(" (blank means the main or default server, otherwise it's\n", r);
1040 ap_rputs(" the name of the VirtualHost); <STRONG>DIR()</STRONG>\n", r);
1041 ap_rputs(" indicates a location in the URL or filesystem\n", r);
1042 ap_rputs(" namespace.\n", r);
1043 ap_rputs(" </P>\n", r);
1044 ap_rprintf(r, " <H2>Startup callbacks so far:</H2>\n <OL>\n%s </OL>\n",
1045 trace);
1046 ap_rputs(" <H2>Connection-specific callbacks so far:</H2>\n", r);
1047
1048 status = apr_pool_userdata_get(&conn_data, CONN_NOTE,
1049 r->connection->pool);
1050 if ((status == APR_SUCCESS) && conn_data) {
1051 ap_rprintf(r, " <OL>\n%s </OL>\n", (char *) conn_data);
1052 } else {
1053 ap_rputs(" <P>No connection-specific callback information was "
1054 "retrieved.</P>\n", r);
1055 }
1056
1057 ap_rputs(" <H2>Request-specific callbacks so far:</H2>\n", r);
1058 ap_rprintf(r, " <OL>\n%s </OL>\n", apr_table_get(r->notes, TRACE_NOTE));
1059 ap_rputs(" <H2>Environment for <EM>this</EM> call:</H2>\n", r);
1060 ap_rputs(" <UL>\n", r);
1061 ap_rprintf(r, " <LI>Applies-to: <SAMP>%s</SAMP>\n </LI>\n", dcfg->loc);
1062 ap_rprintf(r, " <LI>\"Example\" directive declared here: %s\n </LI>\n",
1063 (dcfg->local ? "YES" : "NO"));
1064 ap_rprintf(r, " <LI>\"Example\" inherited: %s\n </LI>\n",
1065 (dcfg->congenital ? "YES" : "NO"));
1066 ap_rputs(" </UL>\n", r);
1067 ap_rputs(" </BODY>\n", r);
1068 ap_rputs("</HTML>\n", r);
1069 /*
1070 * We're all done, so cancel the timeout we set. Since this is probably
1071 * the end of the request we *could* assume this would be done during
1072 * post-processing - but it's possible that another handler might be
1073 * called and inherit our outstanding timer. Not good; to each its own.
1074 */
1075 /*
1076 * We did what we wanted to do, so tell the rest of the server we
1077 * succeeded.
1078 */
1079 return OK;
1080 }
1081
1082 /*
1083 * The quick_handler hook presents modules with a very powerful opportunity to
1084 * serve their content in a very early request phase. Note that this handler
1085 * can not serve any requests from the file system because hooks like
1086 * map_to_storage have not run. The quick_handler hook also runs before any
1087 * authentication and access control.
1088 *
1089 * This hook is used by mod_cache to serve cached content.
1090 *
1091 * This is a RUN_FIRST hook. Return OK if you have served the request,
1092 * DECLINED if you want processing to continue, or a HTTP_* error code to stop
1093 * processing the request.
1094 */
x_quick_handler(request_rec * r,int lookup_uri)1095 static int x_quick_handler(request_rec *r, int lookup_uri)
1096 {
1097 /*
1098 * Log the call and exit.
1099 */
1100 trace_request(r, "x_quick_handler()");
1101 return DECLINED;
1102 }
1103
1104 /*
1105 * This routine is called just after the server accepts the connection,
1106 * but before it is handed off to a protocol module to be served. The point
1107 * of this hook is to allow modules an opportunity to modify the connection
1108 * as soon as possible. The core server uses this phase to setup the
1109 * connection record based on the type of connection that is being used.
1110 *
1111 * This is a RUN_ALL hook.
1112 */
x_pre_connection(conn_rec * c,void * csd)1113 static int x_pre_connection(conn_rec *c, void *csd)
1114 {
1115 char *note;
1116
1117 /*
1118 * Log the call and exit.
1119 */
1120 note = apr_psprintf(c->pool, "x_pre_connection(c = %pp, p = %pp)",
1121 (void*) c, (void*) c->pool);
1122 trace_connection(c, note);
1123
1124 return OK;
1125 }
1126
1127 /* This routine is used to actually process the connection that was received.
1128 * Only protocol modules should implement this hook, as it gives them an
1129 * opportunity to replace the standard HTTP processing with processing for
1130 * some other protocol. Both echo and POP3 modules are available as
1131 * examples.
1132 *
1133 * This is a RUN_FIRST hook.
1134 */
x_process_connection(conn_rec * c)1135 static int x_process_connection(conn_rec *c)
1136 {
1137 trace_connection(c, "x_process_connection()");
1138
1139 return DECLINED;
1140 }
1141
1142 /*
1143 * This routine is called after the request has been read but before any other
1144 * phases have been processed. This allows us to make decisions based upon
1145 * the input header fields.
1146 *
1147 * This is a HOOK_VOID hook.
1148 */
x_pre_read_request(request_rec * r,conn_rec * c)1149 static void x_pre_read_request(request_rec *r, conn_rec *c)
1150 {
1151 /*
1152 * We don't actually *do* anything here, except note the fact that we were
1153 * called.
1154 */
1155 trace_request(r, "x_pre_read_request()");
1156 }
1157
1158 /*
1159 * This routine is called after the request has been read but before any other
1160 * phases have been processed. This allows us to make decisions based upon
1161 * the input header fields.
1162 *
1163 * This is a RUN_ALL hook.
1164 */
x_post_read_request(request_rec * r)1165 static int x_post_read_request(request_rec *r)
1166 {
1167 /*
1168 * We don't actually *do* anything here, except note the fact that we were
1169 * called.
1170 */
1171 trace_request(r, "x_post_read_request()");
1172 return DECLINED;
1173 }
1174
1175 /*
1176 * This routine gives our module an opportunity to translate the URI into an
1177 * actual filename. If we don't do anything special, the server's default
1178 * rules (Alias directives and the like) will continue to be followed.
1179 *
1180 * This is a RUN_FIRST hook.
1181 */
x_translate_name(request_rec * r)1182 static int x_translate_name(request_rec *r)
1183 {
1184
1185 /*
1186 * We don't actually *do* anything here, except note the fact that we were
1187 * called.
1188 */
1189 trace_request(r, "x_translate_name()");
1190 return DECLINED;
1191 }
1192
1193 /*
1194 * This routine maps r->filename to a physical file on disk. Useful for
1195 * overriding default core behavior, including skipping mapping for
1196 * requests that are not file based.
1197 *
1198 * This is a RUN_FIRST hook.
1199 */
x_map_to_storage(request_rec * r)1200 static int x_map_to_storage(request_rec *r)
1201 {
1202 /*
1203 * We don't actually *do* anything here, except note the fact that we were
1204 * called.
1205 */
1206 trace_request(r, "x_map_to_storage()");
1207 return DECLINED;
1208 }
1209
1210 /*
1211 * this routine gives our module another chance to examine the request
1212 * headers and to take special action. This is the first phase whose
1213 * hooks' configuration directives can appear inside the <Directory>
1214 * and similar sections, because at this stage the URI has been mapped
1215 * to the filename. For example this phase can be used to block evil
1216 * clients, while little resources were wasted on these.
1217 *
1218 * This is a RUN_ALL hook.
1219 */
x_header_parser(request_rec * r)1220 static int x_header_parser(request_rec *r)
1221 {
1222 /*
1223 * We don't actually *do* anything here, except note the fact that we were
1224 * called.
1225 */
1226 trace_request(r, "x_header_parser()");
1227 return DECLINED;
1228 }
1229
1230
1231 /*
1232 * This routine is called to check for any module-specific restrictions placed
1233 * upon the requested resource. (See the mod_access_compat module for an
1234 * example.)
1235 *
1236 * This is a RUN_ALL hook. The first handler to return a status other than OK
1237 * or DECLINED (for instance, HTTP_FORBIDDEN) aborts the callback chain.
1238 */
x_check_access(request_rec * r)1239 static int x_check_access(request_rec *r)
1240 {
1241 trace_request(r, "x_check_access()");
1242 return DECLINED;
1243 }
1244
1245 /*
1246 * This routine is called to check the authentication information sent with
1247 * the request (such as looking up the user in a database and verifying that
1248 * the [encrypted] password sent matches the one in the database).
1249 *
1250 * This is a RUN_FIRST hook. The return value is OK, DECLINED, or some
1251 * HTTP_mumble error (typically HTTP_UNAUTHORIZED).
1252 */
x_check_authn(request_rec * r)1253 static int x_check_authn(request_rec *r)
1254 {
1255 /*
1256 * Don't do anything except log the call.
1257 */
1258 trace_request(r, "x_check_authn()");
1259 return DECLINED;
1260 }
1261
1262 /*
1263 * This routine is called to check to see if the resource being requested
1264 * requires authorisation.
1265 *
1266 * This is a RUN_FIRST hook. The return value is OK, DECLINED, or
1267 * HTTP_mumble. If we return OK, no other modules are called during this
1268 * phase.
1269 *
1270 * If *all* modules return DECLINED, the request is aborted with a server
1271 * error.
1272 */
x_check_authz(request_rec * r)1273 static int x_check_authz(request_rec *r)
1274 {
1275 /*
1276 * Log the call and return OK, or access will be denied (even though we
1277 * didn't actually do anything).
1278 */
1279 trace_request(r, "x_check_authz()");
1280 return DECLINED;
1281 }
1282
1283 /*
1284 * This routine is called to determine and/or set the various document type
1285 * information bits, like Content-type (via r->content_type), language, et
1286 * cetera.
1287 *
1288 * This is a RUN_FIRST hook.
1289 */
x_type_checker(request_rec * r)1290 static int x_type_checker(request_rec *r)
1291 {
1292 /*
1293 * Log the call, but don't do anything else - and report truthfully that
1294 * we didn't do anything.
1295 */
1296 trace_request(r, "x_type_checker()");
1297 return DECLINED;
1298 }
1299
1300 /*
1301 * This routine is called to perform any module-specific fixing of header
1302 * fields, et cetera. It is invoked just before any content-handler.
1303 *
1304 * This is a RUN_ALL HOOK.
1305 */
x_fixups(request_rec * r)1306 static int x_fixups(request_rec *r)
1307 {
1308 /*
1309 * Log the call and exit.
1310 */
1311 trace_request(r, "x_fixups()");
1312 return DECLINED;
1313 }
1314
1315 /*
1316 * This routine is called to perform any module-specific logging activities
1317 * over and above the normal server things.
1318 *
1319 * This is a RUN_ALL hook.
1320 */
x_log_transaction(request_rec * r)1321 static int x_log_transaction(request_rec *r)
1322 {
1323 trace_request(r, "x_log_transaction()");
1324 return DECLINED;
1325 }
1326
1327 #ifdef HAVE_UNIX_SUEXEC
1328
1329 /*
1330 * This routine is called to find out under which user id to run suexec
1331 * Unless our module runs CGI programs, there is no reason for us to
1332 * mess with this information.
1333 *
1334 * This is a RUN_FIRST hook. The return value is a pointer to an
1335 * ap_unix_identity_t or NULL.
1336 */
x_get_suexec_identity(const request_rec * r)1337 static ap_unix_identity_t *x_get_suexec_identity(const request_rec *r)
1338 {
1339 trace_request(r, "x_get_suexec_identity()");
1340 return NULL;
1341 }
1342 #endif
1343
1344 /*
1345 * This routine is called to create a connection. This hook is implemented
1346 * by the Apache core: there is no known reason a module should override
1347 * it.
1348 *
1349 * This is a RUN_FIRST hook.
1350 *
1351 * Return NULL to decline, a valid conn_rec pointer to accept.
1352 */
x_create_connection(apr_pool_t * p,server_rec * server,apr_socket_t * csd,long conn_id,void * sbh,apr_bucket_alloc_t * alloc)1353 static conn_rec *x_create_connection(apr_pool_t *p, server_rec *server,
1354 apr_socket_t *csd, long conn_id,
1355 void *sbh, apr_bucket_alloc_t *alloc)
1356 {
1357 trace_nocontext(p, __FILE__, __LINE__, "x_create_connection()");
1358 return NULL;
1359 }
1360
1361 /*
1362 * This hook is defined in server/core.c, but it is not actually called
1363 * or documented.
1364 *
1365 * This is a RUN_ALL hook.
1366 */
x_get_mgmt_items(apr_pool_t * p,const char * val,apr_hash_t * ht)1367 static int x_get_mgmt_items(apr_pool_t *p, const char *val, apr_hash_t *ht)
1368 {
1369 /* We have nothing to do here but trace the call, and no context
1370 * in which to trace it.
1371 */
1372 trace_nocontext(p, __FILE__, __LINE__, "x_check_config()");
1373 return DECLINED;
1374 }
1375
1376 /*
1377 * This routine gets called shortly after the request_rec structure
1378 * is created. It provides the opportunity to manipulae the request
1379 * at a very early stage.
1380 *
1381 * This is a RUN_ALL hook.
1382 */
x_create_request(request_rec * r)1383 static int x_create_request(request_rec *r)
1384 {
1385 /*
1386 * We have a request_rec, but it is not filled in enough to give
1387 * us a usable configuration. So, add a trace without context.
1388 */
1389 trace_nocontext( r->pool, __FILE__, __LINE__, "x_create_request()");
1390 return DECLINED;
1391 }
1392
1393 /*
1394 * This routine gets called during the startup of the MPM.
1395 * No known existing module implements this hook.
1396 *
1397 * This is a RUN_ALL hook.
1398 */
x_pre_mpm(apr_pool_t * p,ap_scoreboard_e sb_type)1399 static int x_pre_mpm(apr_pool_t *p, ap_scoreboard_e sb_type)
1400 {
1401 trace_nocontext(p, __FILE__, __LINE__, "x_pre_mpm()");
1402 return DECLINED;
1403 }
1404
1405 /*
1406 * This hook gets run periodically by a maintenance function inside
1407 * the MPM. Its exact purpose is unknown and undocumented at this time.
1408 *
1409 * This is a RUN_ALL hook.
1410 */
x_monitor(apr_pool_t * p,server_rec * s)1411 static int x_monitor(apr_pool_t *p, server_rec *s)
1412 {
1413 trace_nocontext(p, __FILE__, __LINE__, "x_monitor()");
1414 return DECLINED;
1415 }
1416
1417 /*--------------------------------------------------------------------------*/
1418 /* */
1419 /* Which functions are responsible for which hooks in the server. */
1420 /* */
1421 /*--------------------------------------------------------------------------*/
1422 /*
1423 * Each function our module provides to handle a particular hook is
1424 * specified here. The functions are registered using
1425 * ap_hook_foo(name, predecessors, successors, position)
1426 * where foo is the name of the hook.
1427 *
1428 * The args are as follows:
1429 * name -> the name of the function to call.
1430 * predecessors -> a list of modules whose calls to this hook must be
1431 * invoked before this module.
1432 * successors -> a list of modules whose calls to this hook must be
1433 * invoked after this module.
1434 * position -> The relative position of this module. One of
1435 * APR_HOOK_FIRST, APR_HOOK_MIDDLE, or APR_HOOK_LAST.
1436 * Most modules will use APR_HOOK_MIDDLE. If multiple
1437 * modules use the same relative position, Apache will
1438 * determine which to call first.
1439 * If your module relies on another module to run first,
1440 * or another module running after yours, use the
1441 * predecessors and/or successors.
1442 *
1443 * The number in brackets indicates the order in which the routine is called
1444 * during request processing. Note that not all routines are necessarily
1445 * called (such as if a resource doesn't have access restrictions).
1446 * The actual delivery of content to the browser [9] is not handled by
1447 * a hook; see the handler declarations below.
1448 */
x_register_hooks(apr_pool_t * p)1449 static void x_register_hooks(apr_pool_t *p)
1450 {
1451 ap_hook_pre_config(x_pre_config, NULL, NULL, APR_HOOK_MIDDLE);
1452 ap_hook_check_config(x_check_config, NULL, NULL, APR_HOOK_MIDDLE);
1453 ap_hook_test_config(x_test_config, NULL, NULL, APR_HOOK_MIDDLE);
1454 ap_hook_open_logs(x_open_logs, NULL, NULL, APR_HOOK_MIDDLE);
1455 ap_hook_post_config(x_post_config, NULL, NULL, APR_HOOK_MIDDLE);
1456 ap_hook_child_init(x_child_init, NULL, NULL, APR_HOOK_MIDDLE);
1457 ap_hook_handler(x_handler, NULL, NULL, APR_HOOK_MIDDLE);
1458 ap_hook_quick_handler(x_quick_handler, NULL, NULL, APR_HOOK_MIDDLE);
1459 ap_hook_pre_connection(x_pre_connection, NULL, NULL, APR_HOOK_MIDDLE);
1460 ap_hook_process_connection(x_process_connection, NULL, NULL, APR_HOOK_MIDDLE);
1461 ap_hook_pre_read_request(x_pre_read_request, NULL, NULL,
1462 APR_HOOK_MIDDLE);
1463 /* [1] post read_request handling */
1464 ap_hook_post_read_request(x_post_read_request, NULL, NULL,
1465 APR_HOOK_MIDDLE);
1466 ap_hook_log_transaction(x_log_transaction, NULL, NULL, APR_HOOK_MIDDLE);
1467 ap_hook_http_scheme(x_http_scheme, NULL, NULL, APR_HOOK_MIDDLE);
1468 ap_hook_default_port(x_default_port, NULL, NULL, APR_HOOK_MIDDLE);
1469 ap_hook_translate_name(x_translate_name, NULL, NULL, APR_HOOK_MIDDLE);
1470 ap_hook_map_to_storage(x_map_to_storage, NULL,NULL, APR_HOOK_MIDDLE);
1471 ap_hook_header_parser(x_header_parser, NULL, NULL, APR_HOOK_MIDDLE);
1472 ap_hook_fixups(x_fixups, NULL, NULL, APR_HOOK_MIDDLE);
1473 ap_hook_type_checker(x_type_checker, NULL, NULL, APR_HOOK_MIDDLE);
1474 ap_hook_check_access(x_check_access, NULL, NULL, APR_HOOK_MIDDLE,
1475 AP_AUTH_INTERNAL_PER_CONF);
1476 ap_hook_check_authn(x_check_authn, NULL, NULL, APR_HOOK_MIDDLE,
1477 AP_AUTH_INTERNAL_PER_CONF);
1478 ap_hook_check_authz(x_check_authz, NULL, NULL, APR_HOOK_MIDDLE,
1479 AP_AUTH_INTERNAL_PER_CONF);
1480 ap_hook_insert_filter(x_insert_filter, NULL, NULL, APR_HOOK_MIDDLE);
1481 ap_hook_insert_error_filter(x_insert_error_filter, NULL, NULL, APR_HOOK_MIDDLE);
1482 #ifdef HAVE_UNIX_SUEXEC
1483 ap_hook_get_suexec_identity(x_get_suexec_identity, NULL, NULL, APR_HOOK_MIDDLE);
1484 #endif
1485 ap_hook_create_connection(x_create_connection, NULL, NULL, APR_HOOK_MIDDLE);
1486 ap_hook_get_mgmt_items(x_get_mgmt_items, NULL, NULL, APR_HOOK_MIDDLE);
1487 ap_hook_create_request(x_create_request, NULL, NULL, APR_HOOK_MIDDLE);
1488 ap_hook_pre_mpm(x_pre_mpm, NULL, NULL, APR_HOOK_MIDDLE);
1489 ap_hook_monitor(x_monitor, NULL, NULL, APR_HOOK_MIDDLE);
1490 }
1491
1492 /*--------------------------------------------------------------------------*/
1493 /* */
1494 /* All of the routines have been declared now. Here's the list of */
1495 /* directives specific to our module, and information about where they */
1496 /* may appear and how the command parser should pass them to us for */
1497 /* processing. Note that care must be taken to ensure that there are NO */
1498 /* collisions of directive names between modules. */
1499 /* */
1500 /*--------------------------------------------------------------------------*/
1501 /*
1502 * List of directives specific to our module.
1503 */
1504 static const command_rec x_cmds[] =
1505 {
1506 AP_INIT_NO_ARGS(
1507 "Example", /* directive name */
1508 cmd_example, /* config action routine */
1509 NULL, /* argument to include in call */
1510 OR_OPTIONS, /* where available */
1511 "Example directive - no arguments" /* directive description */
1512 ),
1513 {NULL}
1514 };
1515 /*--------------------------------------------------------------------------*/
1516 /* */
1517 /* Finally, the list of callback routines and data structures that provide */
1518 /* the static hooks into our module from the other parts of the server. */
1519 /* */
1520 /*--------------------------------------------------------------------------*/
1521 /*
1522 * Module definition for configuration. If a particular callback is not
1523 * needed, replace its routine name below with the word NULL.
1524 */
1525 AP_DECLARE_MODULE(example_hooks) =
1526 {
1527 STANDARD20_MODULE_STUFF,
1528 x_create_dir_config, /* per-directory config creator */
1529 x_merge_dir_config, /* dir config merger */
1530 x_create_server_config, /* server config creator */
1531 x_merge_server_config, /* server config merger */
1532 x_cmds, /* command table */
1533 x_register_hooks, /* set up other request processing hooks */
1534 };
1535