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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #include "mod_session.h"
19 #include "apr_strings.h"
20 #include "util_filter.h"
22 #include "http_request.h"
23 #include "http_protocol.h"
25 #define SESSION_EXPIRY "expiry"
26 #define HTTP_SESSION "HTTP_SESSION"
29 APR_HOOK_LINK(session_load)
30 APR_HOOK_LINK(session_save)
31 APR_HOOK_LINK(session_encode)
32 APR_HOOK_LINK(session_decode)
34 APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ap, SESSION, int, session_load,
35 (request_rec * r, session_rec ** z), (r, z), DECLINED)
36 APR_IMPLEMENT_EXTERNAL_HOOK_RUN_FIRST(ap, SESSION, int, session_save,
37 (request_rec * r, session_rec * z), (r, z), DECLINED)
38 APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, SESSION, int, session_encode,
39 (request_rec * r, session_rec * z), (r, z), OK, DECLINED)
40 APR_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(ap, SESSION, int, session_decode,
41 (request_rec * r, session_rec * z), (r, z), OK, DECLINED)
43 static int session_identity_encode(request_rec * r, session_rec * z);
44 static int session_identity_decode(request_rec * r, session_rec * z);
45 static int session_fixups(request_rec * r);
48 * Should the session be included within this URL.
50 * This function tests whether a session is valid for this URL. It uses the
51 * include and exclude arrays to determine whether they should be included.
53 static int session_included(request_rec * r, session_dir_conf * conf)
56 const char **includes = (const char **) conf->includes->elts;
57 const char **excludes = (const char **) conf->excludes->elts;
58 int included = 1; /* defaults to included */
61 if (conf->includes->nelts) {
63 for (i = 0; !included && i < conf->includes->nelts; i++) {
64 const char *include = includes[i];
65 if (strncmp(r->uri, include, strlen(include))) {
71 if (conf->excludes->nelts) {
72 for (i = 0; included && i < conf->includes->nelts; i++) {
73 const char *exclude = excludes[i];
74 if (strncmp(r->uri, exclude, strlen(exclude))) {
86 * If the session doesn't exist, a blank one will be created.
88 * @param r The request
89 * @param z A pointer to where the session will be written.
91 static apr_status_t ap_session_load(request_rec * r, session_rec ** z)
94 session_dir_conf *dconf = ap_get_module_config(r->per_dir_config,
97 session_rec *zz = NULL;
100 /* is the session enabled? */
101 if (!dconf || !dconf->enabled) {
105 /* should the session be loaded at all? */
106 if (!session_included(r, dconf)) {
107 ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
108 "excluded by configuration for: %s", r->uri);
112 /* load the session from the session hook */
113 rv = ap_run_session_load(r, &zz);
114 if (DECLINED == rv) {
115 ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r,
116 "session is enabled but no session modules have been configured, "
117 "session not loaded: %s", r->uri);
121 ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
122 "error while loading the session, "
123 "session not loaded: %s", r->uri);
127 /* found a session that hasn't expired? */
128 now = apr_time_now();
129 if (!zz || (zz->expiry && zz->expiry < now)) {
131 /* no luck, create a blank session */
132 zz = (session_rec *) apr_pcalloc(r->pool, sizeof(session_rec));
134 zz->entries = apr_table_make(zz->pool, 10);
135 zz->uuid = (apr_uuid_t *) apr_pcalloc(zz->pool, sizeof(apr_uuid_t));
136 apr_uuid_get(zz->uuid);
140 rv = ap_run_session_decode(r, zz);
142 ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
143 "error while decoding the session, "
144 "session not loaded: %s", r->uri);
149 /* make sure the expiry is set, if present */
150 if (!zz->expiry && dconf->maxage) {
151 zz->expiry = now + dconf->maxage * APR_USEC_PER_SEC;
152 zz->maxage = dconf->maxage;
164 * In most implementations the session is only saved if the dirty flag is
165 * true. This prevents the session being saved unnecessarily.
167 * @param r The request
168 * @param z A pointer to where the session will be written.
170 static apr_status_t ap_session_save(request_rec * r, session_rec * z)
173 apr_time_t now = apr_time_now();
176 session_dir_conf *dconf = ap_get_module_config(r->per_dir_config,
179 /* sanity checks, should we try save at all? */
181 ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
182 "attempt made to save the session twice, "
183 "session not saved: %s", r->uri);
186 if (z->expiry && z->expiry < now) {
187 ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r,
188 "attempt made to save a session when the session had already expired, "
189 "session not saved: %s", r->uri);
193 /* reset the expiry back to maxage, if the expiry is present */
195 z->expiry = now + dconf->maxage * APR_USEC_PER_SEC;
196 z->maxage = dconf->maxage;
199 /* encode the session */
200 rv = ap_run_session_encode(r, z);
202 ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
203 "error while encoding the session, "
204 "session not saved: %s", r->uri);
209 rv = ap_run_session_save(r, z);
210 if (DECLINED == rv) {
211 ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r,
212 "session is enabled but no session modules have been configured, "
213 "session not saved: %s", r->uri);
217 ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
218 "error while saving the session, "
219 "session not saved: %s", r->uri);
232 * Get a particular value from the session.
233 * @param r The current request.
234 * @param z The current session. If this value is NULL, the session will be
235 * looked up in the request, created if necessary, and saved to the request
237 * @param key The key to get.
238 * @param value The buffer to write the value to.
240 static apr_status_t ap_session_get(request_rec * r, session_rec * z,
241 const char *key, const char **value)
245 rv = ap_session_load(r, &z);
246 if (APR_SUCCESS != rv) {
250 if (z && z->entries) {
251 *value = apr_table_get(z->entries, key);
258 * Set a particular value to the session.
260 * Using this method ensures that the dirty flag is set correctly, so that
261 * the session can be saved efficiently.
262 * @param r The current request.
263 * @param z The current session. If this value is NULL, the session will be
264 * looked up in the request, created if necessary, and saved to the request
266 * @param key The key to set. The existing key value will be replaced.
267 * @param value The value to set.
269 static apr_status_t ap_session_set(request_rec * r, session_rec * z,
270 const char *key, const char *value)
274 rv = ap_session_load(r, &z);
275 if (APR_SUCCESS != rv) {
281 apr_table_set(z->entries, key, value);
284 apr_table_unset(z->entries, key);
291 static int identity_count(int *count, const char *key, const char *val)
293 *count += strlen(key) * 3 + strlen(val) * 3 + 1;
297 static int identity_concat(char *buffer, const char *key, const char *val)
299 char *slider = buffer;
300 int length = strlen(slider);
306 ap_escape_path_segment_buffer(slider, key);
307 slider += strlen(slider);
310 ap_escape_path_segment_buffer(slider, val);
315 * Default identity encoding for the session.
317 * By default, the name value pairs in the session are URLEncoded, separated
318 * by equals, and then in turn separated by ampersand, in the format of an
321 * This was chosen to make it easy for external code to unpack a session,
322 * should there be a need to do so.
324 * @param r The request pointer.
325 * @param z A pointer to where the session will be written.
327 static apr_status_t session_identity_encode(request_rec * r, session_rec * z)
333 char *expiry = apr_psprintf(z->pool, "%" APR_INT64_T_FMT, z->expiry);
334 apr_table_setn(z->entries, SESSION_EXPIRY, expiry);
336 apr_table_do((int (*) (void *, const char *, const char *))
337 identity_count, &length, z->entries, NULL);;
338 buffer = apr_pcalloc(r->pool, length + 1);
339 apr_table_do((int (*) (void *, const char *, const char *))
340 identity_concat, buffer, z->entries, NULL);
347 * Default identity decoding for the session.
349 * By default, the name value pairs in the session are URLEncoded, separated
350 * by equals, and then in turn separated by ampersand, in the format of an
353 * This was chosen to make it easy for external code to unpack a session,
354 * should there be a need to do so.
356 * This function reverses that process, and populates the session table.
358 * Name / value pairs that are not encoded properly are ignored.
360 * @param r The request pointer.
361 * @param z A pointer to where the session will be written.
363 static apr_status_t session_identity_decode(request_rec * r, session_rec * z)
367 char *encoded, *pair;
368 const char *sep = "&";
370 /* sanity check - anything to decode? */
375 /* decode what we have */
376 encoded = apr_pstrcat(r->pool, z->encoded, NULL);
377 pair = apr_strtok(encoded, sep, &last);
378 while (pair && pair[0]) {
380 const char *psep = "=";
381 char *key = apr_strtok(pair, psep, &plast);
382 char *val = apr_strtok(NULL, psep, &plast);
385 apr_table_unset(z->entries, key);
387 else if (!ap_unescape_all(key) && !ap_unescape_all(val)) {
388 if (!strcmp(SESSION_EXPIRY, key)) {
389 z->expiry = (apr_time_t) apr_atoi64(val);
392 apr_table_set(z->entries, key, val);
396 pair = apr_strtok(NULL, sep, &last);
404 * Ensure any changes to the session are committed.
406 * This is done in an output filter so that our options for where to
407 * store the session can include storing the session within a cookie:
408 * As an HTTP header, the cookie must be set before the output is
409 * written, but after the handler is run.
411 * NOTE: It is possible for internal redirects to cause more than one
412 * request to be present, and each request might have a session
413 * defined. We need to go through each session in turn, and save each
416 * The same session might appear in more than one request. The first
417 * attempt to save the session will be called
419 static apr_status_t session_output_filter(ap_filter_t * f,
420 apr_bucket_brigade * in)
423 /* save all the sessions in all the requests */
424 request_rec *r = f->r->main;
429 session_rec *z = NULL;
430 session_dir_conf *conf = ap_get_module_config(r->per_dir_config,
433 /* load the session, or create one if necessary */
434 /* when unset or on error, z will be NULL */
435 ap_session_load(r, &z);
436 if (!z || z->written) {
441 /* if a header was specified, insert the new values from the header */
442 if (conf->header_set) {
443 const char *override = apr_table_get(r->err_headers_out, conf->header);
445 override = apr_table_get(r->headers_out, conf->header);
448 z->encoded = override;
449 session_identity_decode(r, z);
453 /* save away the session, and we're done */
454 /* when unset or on error, we've complained to the log */
455 ap_session_save(r, z);
460 /* remove ourselves from the filter chain */
461 ap_remove_output_filter(f);
463 /* send the data up the stack */
464 return ap_pass_brigade(f->next, in);
469 * Insert the output filter.
471 static void session_insert_output_filter(request_rec * r)
473 ap_add_output_filter("MOD_SESSION_OUT", NULL, r, r->connection);
479 * Load the session within a fixup - this ensures that the session is
480 * properly loaded prior to the handler being called.
482 * The fixup is also responsible for injecting the session into the CGI
483 * environment, should the admin have configured it so.
485 * @param r The request
487 static int session_fixups(request_rec * r)
489 session_dir_conf *conf = ap_get_module_config(r->per_dir_config,
492 session_rec *z = NULL;
494 /* if an error occurs or no session has been configured, we ignore
495 * the broken session and allow it to be recreated from scratch on save
498 ap_session_load(r, &z);
500 if (z && conf->env) {
501 session_identity_encode(r, z);
503 apr_table_set(r->subprocess_env, HTTP_SESSION, z->encoded);
513 static void *create_session_dir_config(apr_pool_t * p, char *dummy)
515 session_dir_conf *new =
516 (session_dir_conf *) apr_pcalloc(p, sizeof(session_dir_conf));
518 new->includes = apr_array_make(p, 10, sizeof(const char **));
519 new->excludes = apr_array_make(p, 10, sizeof(const char **));
524 static void *merge_session_dir_config(apr_pool_t * p, void *basev, void *addv)
526 session_dir_conf *new = (session_dir_conf *) apr_pcalloc(p, sizeof(session_dir_conf));
527 session_dir_conf *add = (session_dir_conf *) addv;
528 session_dir_conf *base = (session_dir_conf *) basev;
530 new->enabled = (add->enabled_set == 0) ? base->enabled : add->enabled;
531 new->enabled_set = add->enabled_set || base->enabled_set;
532 new->maxage = (add->maxage_set == 0) ? base->maxage : add->maxage;
533 new->maxage_set = add->maxage_set || base->maxage_set;
534 new->header = (add->header_set == 0) ? base->header : add->header;
535 new->header_set = add->header_set || base->header_set;
536 new->env = (add->env_set == 0) ? base->env : add->env;
537 new->env_set = add->env_set || base->env_set;
538 new->includes = apr_array_append(p, base->includes, add->includes);
539 new->excludes = apr_array_append(p, base->excludes, add->excludes);
546 set_session_enable(cmd_parms * parms, void *dconf, int flag)
548 session_dir_conf *conf = dconf;
550 conf->enabled = flag;
551 conf->enabled_set = 1;
557 set_session_maxage(cmd_parms * parms, void *dconf, const char *arg)
559 session_dir_conf *conf = dconf;
561 conf->maxage = atol(arg);
562 conf->maxage_set = 1;
568 set_session_header(cmd_parms * parms, void *dconf, const char *arg)
570 session_dir_conf *conf = dconf;
573 conf->header_set = 1;
579 set_session_env(cmd_parms * parms, void *dconf, int flag)
581 session_dir_conf *conf = dconf;
589 static const char *add_session_include(cmd_parms * cmd, void *dconf, const char *f)
591 session_dir_conf *conf = dconf;
593 const char **new = apr_array_push(conf->includes);
599 static const char *add_session_exclude(cmd_parms * cmd, void *dconf, const char *f)
601 session_dir_conf *conf = dconf;
603 const char **new = apr_array_push(conf->excludes);
610 static const command_rec session_cmds[] =
612 AP_INIT_FLAG("Session", set_session_enable, NULL, RSRC_CONF|OR_AUTHCFG,
613 "on if a session should be maintained for these URLs"),
614 AP_INIT_TAKE1("SessionMaxAge", set_session_maxage, NULL, RSRC_CONF|OR_AUTHCFG,
615 "length of time for which a session should be valid. Zero to disable"),
616 AP_INIT_TAKE1("SessionHeader", set_session_header, NULL, RSRC_CONF|OR_AUTHCFG,
617 "output header, if present, whose contents will be injected into the session."),
618 AP_INIT_FLAG("SessionEnv", set_session_env, NULL, RSRC_CONF|OR_AUTHCFG,
619 "on if a session should be written to the CGI environment. Defaults to off"),
620 AP_INIT_TAKE1("SessionInclude", add_session_include, NULL, RSRC_CONF|OR_AUTHCFG,
621 "URL prefixes to include in the session. Defaults to all URLs"),
622 AP_INIT_TAKE1("SessionExclude", add_session_exclude, NULL, RSRC_CONF|OR_AUTHCFG,
623 "URL prefixes to exclude from the session. Defaults to no URLs"),
627 static void register_hooks(apr_pool_t * p)
629 ap_register_output_filter("MOD_SESSION_OUT", session_output_filter,
630 NULL, AP_FTYPE_CONTENT_SET);
631 ap_hook_insert_filter(session_insert_output_filter, NULL, NULL,
633 ap_hook_insert_error_filter(session_insert_output_filter,
634 NULL, NULL, APR_HOOK_MIDDLE);
635 ap_hook_fixups(session_fixups, NULL, NULL, APR_HOOK_MIDDLE);
636 ap_hook_session_encode(session_identity_encode, NULL, NULL,
637 APR_HOOK_REALLY_FIRST);
638 ap_hook_session_decode(session_identity_decode, NULL, NULL,
639 APR_HOOK_REALLY_LAST);
640 APR_REGISTER_OPTIONAL_FN(ap_session_get);
641 APR_REGISTER_OPTIONAL_FN(ap_session_set);
642 APR_REGISTER_OPTIONAL_FN(ap_session_load);
643 APR_REGISTER_OPTIONAL_FN(ap_session_save);
646 AP_DECLARE_MODULE(session) =
648 STANDARD20_MODULE_STUFF,
649 create_session_dir_config, /* dir config creater */
650 merge_session_dir_config, /* dir merger --- default is to override */
651 NULL, /* server config */
652 NULL, /* merge server config */
653 session_cmds, /* command apr_table_t */
654 register_hooks /* register hooks */