2 * Copyright (C) 2015-2019 "IoT.bzh"
3 * Author "Fulup Ar Foll"
4 * Author: José Bollo <jose.bollo@iot.bzh>
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
29 #include "afb-session.h"
31 #include "afb-token.h"
38 #define COOKIEMASK (COOKIECOUNT - 1)
40 #define _MAXEXP_ ((time_t)(~(time_t)0))
41 #define _MAXEXP2_ ((time_t)((((unsigned long long)_MAXEXP_) >> 1)))
42 #define MAX_EXPIRATION (_MAXEXP_ >= 0 ? _MAXEXP_ : _MAXEXP2_)
43 #define NOW (time_now())
46 * structure for a cookie added to sessions
50 struct cookie *next; /**< link to next cookie */
51 const void *key; /**< pointer key */
52 void *value; /**< value */
53 void (*freecb)(void*); /**< function to call when session is closed */
57 * structure for session
61 struct afb_session *next; /**< link to the next */
62 unsigned refcount; /**< count of reference to the session */
63 int timeout; /**< timeout of the session */
64 time_t expiration; /**< expiration time of the session */
65 pthread_mutex_t mutex; /**< mutex of the session */
66 struct cookie *cookies[COOKIECOUNT]; /**< cookies of the session */
67 char *lang; /**< current language setting for the session */
68 uint8_t closed: 1; /**< is the session closed ? */
69 uint8_t autoclose: 1; /**< close the session when unreferenced */
70 uint8_t notinset: 1; /**< session removed from the set of sessions */
71 uuid_stringz_t uuid; /**< indentification of client seesion */
75 * structure for managing sessions
78 int count; /**< current number of sessions */
79 int max; /**< maximum count of sessions */
80 int timeout; /**< common initial timeout */
81 struct afb_session *heads[HEADCOUNT]; /**< sessions */
82 struct afb_token *initok;/**< common initial token */
83 pthread_mutex_t mutex; /**< declare a mutex to protect hash table */
90 .mutex = PTHREAD_MUTEX_INITIALIZER
94 * Get the actual raw time
96 static inline time_t time_now()
99 clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
103 /* lock the set of sessions for exclusive access */
104 static inline void sessionset_lock()
106 pthread_mutex_lock(&sessions.mutex);
109 /* unlock the set of sessions of exclusive access */
110 static inline void sessionset_unlock()
112 pthread_mutex_unlock(&sessions.mutex);
116 * search within the set of sessions the session of 'uuid'.
117 * 'hashidx' is the precomputed hash for 'uuid'
118 * return the session or NULL
120 static struct afb_session *sessionset_search(const char *uuid, uint8_t hashidx)
122 struct afb_session *session;
124 session = sessions.heads[hashidx];
125 while (session && strcmp(uuid, session->uuid))
126 session = session->next;
131 /* add 'session' to the set of sessions */
132 static int sessionset_add(struct afb_session *session, uint8_t hashidx)
134 /* check availability */
135 if (sessions.max && sessions.count >= sessions.max) {
140 /* add the session */
141 session->next = sessions.heads[hashidx];
142 sessions.heads[hashidx] = session;
147 /* make a new uuid not used in the set of sessions */
148 static uint8_t sessionset_make_uuid (uuid_stringz_t uuid)
153 uuid_new_stringz(uuid);
154 hashidx = pearson4(uuid);
155 } while(sessionset_search(uuid, hashidx));
159 /* lock the 'session' for exclusive access */
160 static inline void session_lock(struct afb_session *session)
162 pthread_mutex_lock(&session->mutex);
165 /* unlock the 'session' of exclusive access */
166 static inline void session_unlock(struct afb_session *session)
168 pthread_mutex_unlock(&session->mutex);
171 /* close the 'session' */
172 static void session_close(struct afb_session *session)
175 struct cookie *cookie;
177 /* close only one time */
178 if (!session->closed) {
184 afb_hook_session_close(session);
187 /* release cookies */
188 for (idx = 0 ; idx < COOKIECOUNT ; idx++) {
189 while ((cookie = session->cookies[idx])) {
190 session->cookies[idx] = cookie->next;
191 if (cookie->freecb != NULL)
192 cookie->freecb(cookie->value);
199 /* destroy the 'session' */
200 static void session_destroy (struct afb_session *session)
203 afb_hook_session_destroy(session);
205 pthread_mutex_destroy(&session->mutex);
210 /* update expiration of 'session' according to 'now' */
211 static void session_update_expiration(struct afb_session *session, time_t now)
215 /* compute expiration */
216 expiration = now + afb_session_timeout(session);
218 expiration = MAX_EXPIRATION;
220 /* record the expiration */
221 session->expiration = expiration;
225 * Add a new session with the 'uuid' (of 'hashidx')
226 * and the 'timeout' starting from 'now'.
227 * Add it to the set of sessions
228 * Return the created session
230 static struct afb_session *session_add(const char *uuid, int timeout, time_t now, uint8_t hashidx)
232 struct afb_session *session;
234 /* check arguments */
235 if (!AFB_SESSION_TIMEOUT_IS_VALID(timeout)
236 || (uuid && strlen(uuid) >= sizeof session->uuid)) {
241 /* allocates a new one */
242 session = calloc(1, sizeof *session);
243 if (session == NULL) {
249 pthread_mutex_init(&session->mutex, NULL);
250 session->refcount = 1;
251 strcpy(session->uuid, uuid);
252 session->timeout = timeout;
253 session_update_expiration(session, now);
256 if (sessionset_add(session, hashidx)) {
262 afb_hook_session_create(session);
268 /* Remove expired sessions and return current time (now) */
269 static time_t sessionset_cleanup (int force)
271 struct afb_session *session, **prv;
275 /* Loop on Sessions Table and remove anything that is older than timeout */
277 for (idx = 0 ; idx < HEADCOUNT; idx++) {
278 prv = &sessions.heads[idx];
279 while ((session = *prv)) {
280 session_lock(session);
281 if (force || session->expiration < now)
282 session_close(session);
283 if (!session->closed)
284 prv = &session->next;
286 *prv = session->next;
288 session->notinset = 1;
289 if ( !session->refcount) {
290 session_destroy(session);
294 session_unlock(session);
301 * Initialize the session manager with a 'max_session_count',
302 * an initial common 'timeout' and an initial common token 'initok'.
304 * @param max_session_count maximum allowed session count in the same time
305 * @param timeout the initial default timeout of sessions
306 * @param initok the initial default token of sessions
308 int afb_session_init (int max_session_count, int timeout, const char *initok)
313 /* check parameters */
314 if (initok && strlen(initok) >= sizeof sessions.initok) {
315 ERROR("initial token '%s' too long (max length %d)",
316 initok, ((int)(sizeof sessions.initok)) - 1);
321 /* init the sessionset (after cleanup) */
323 sessionset_cleanup(1);
324 sessions.max = max_session_count;
325 sessions.timeout = timeout;
326 if (initok == NULL) {
327 uuid_new_stringz(uuid);
332 rc = afb_token_get(&sessions.initok, initok);
341 * Iterate the sessions and call 'callback' with
342 * the 'closure' for each session.
344 void afb_session_foreach(void (*callback)(void *closure, struct afb_session *session), void *closure)
346 struct afb_session *session;
349 /* Loop on Sessions Table and remove anything that is older than timeout */
351 for (idx = 0 ; idx < HEADCOUNT; idx++) {
352 session = sessions.heads[idx];
354 if (!session->closed)
355 callback(closure, session);
356 session = session->next;
363 * Cleanup the sessionset of its closed or expired sessions
365 void afb_session_purge()
368 sessionset_cleanup(0);
373 * @return the initial token set at initialization
375 const char *afb_session_initial_token()
377 return sessions.initok ? afb_token_string(sessions.initok) : "";
380 /* Searchs the session of 'uuid' */
381 struct afb_session *afb_session_search (const char *uuid)
383 struct afb_session *session;
386 sessionset_cleanup(0);
387 session = sessionset_search(uuid, pearson4(uuid));
388 session = afb_session_addref(session);
395 * Creates a new session with 'timeout'
397 struct afb_session *afb_session_create (int timeout)
399 return afb_session_get(NULL, timeout, NULL);
403 * Returns the timeout of 'session' in seconds
405 int afb_session_timeout(struct afb_session *session)
409 /* compute timeout */
410 timeout = session->timeout;
411 if (timeout == AFB_SESSION_TIMEOUT_DEFAULT)
412 timeout = sessions.timeout;
419 * Returns the second remaining before expiration of 'session'
421 int afb_session_what_remains(struct afb_session *session)
423 return (int)(session->expiration - NOW);
426 /* This function will return exiting session or newly created session */
427 struct afb_session *afb_session_get (const char *uuid, int timeout, int *created)
429 uuid_stringz_t _uuid_;
431 struct afb_session *session;
437 now = sessionset_cleanup(0);
439 /* search for an existing one not too old */
441 hashidx = sessionset_make_uuid(_uuid_);
444 hashidx = pearson4(uuid);
445 session = sessionset_search(uuid, hashidx);
448 afb_session_addref(session);
453 /* create the session */
454 session = session_add(uuid, timeout, now, hashidx);
464 /* increase the use count on 'session' (can be NULL) */
465 struct afb_session *afb_session_addref(struct afb_session *session)
467 if (session != NULL) {
469 afb_hook_session_addref(session);
471 session_lock(session);
473 session_unlock(session);
478 /* decrease the use count of 'session' (can be NULL) */
479 void afb_session_unref(struct afb_session *session)
485 afb_hook_session_unref(session);
487 session_lock(session);
488 if (!--session->refcount) {
489 if (session->autoclose)
490 session_close(session);
491 if (session->notinset) {
492 session_destroy(session);
496 session_unlock(session);
499 /* close 'session' */
500 void afb_session_close (struct afb_session *session)
502 session_lock(session);
503 session_close(session);
504 session_unlock(session);
508 * Set the 'autoclose' flag of the 'session'
510 * A session whose autoclose flag is true will close as
511 * soon as it is no more referenced.
513 * @param session the session to set
514 * @param autoclose the value to set
516 void afb_session_set_autoclose(struct afb_session *session, int autoclose)
518 session->autoclose = !!autoclose;
521 /* is 'session' closed? */
522 int afb_session_is_closed (struct afb_session *session)
524 return session->closed;
527 /* Returns the uuid of 'session' */
528 const char *afb_session_uuid (struct afb_session *session)
530 return session->uuid;
534 * Get the index of the 'key' in the cookies array.
535 * @param key the key to scan
536 * @return the index of the list for key within cookies
538 static int cookeyidx(const void *key)
540 intptr_t x = (intptr_t)key;
541 unsigned r = (unsigned)((x >> 5) ^ (x >> 15));
542 return r & COOKIEMASK;
546 * Set, get, replace, remove a cookie of 'key' for the 'session'
548 * The behaviour of this function depends on its parameters:
550 * @param session the session
551 * @param key the key of the cookie
552 * @param makecb the creation function or NULL
553 * @param freecb the release function or NULL
554 * @param closure an argument for makecb or the value if makecb==NULL
555 * @param replace a boolean enforcing replacement of the previous value
557 * @return the value of the cookie
559 * The 'key' is a pointer and compared as pointers.
561 * For getting the current value of the cookie:
563 * afb_session_cookie(session, key, NULL, NULL, NULL, 0)
565 * For storing the value of the cookie
567 * afb_session_cookie(session, key, NULL, NULL, value, 1)
569 void *afb_session_cookie(struct afb_session *session, const void *key, void *(*makecb)(void *closure), void (*freecb)(void *item), void *closure, int replace)
573 struct cookie *cookie, **prv;
575 /* get key hashed index */
576 idx = cookeyidx(key);
578 /* lock session and search for the cookie of 'key' */
579 session_lock(session);
580 prv = &session->cookies[idx];
584 /* 'key' not found, create value using 'closure' and 'makecb' */
585 value = makecb ? makecb(closure) : closure;
586 /* store the the only if it has some meaning */
587 if (replace || makecb || freecb) {
588 cookie = malloc(sizeof *cookie);
591 /* calling freecb if there is no makecb may have issue */
592 if (makecb && freecb)
597 cookie->value = value;
598 cookie->freecb = freecb;
604 } else if (cookie->key == key) {
605 /* cookie of key found */
607 /* not replacing, get the value */
608 value = cookie->value;
610 /* create value using 'closure' and 'makecb' */
611 value = makecb ? makecb(closure) : closure;
613 /* free previous value is needed */
614 if (cookie->value != value && cookie->freecb)
615 cookie->freecb(cookie->value);
617 /* if both value and freecb are NULL drop the cookie */
618 if (!value && !freecb) {
622 /* store the value and its releaser */
623 cookie->value = value;
624 cookie->freecb = freecb;
629 prv = &(cookie->next);
633 /* unlock the session and return the value */
634 session_unlock(session);
639 * Get the cookie of 'key' in the 'session'.
641 * @param session the session to search in
642 * @param key the key of the data to retrieve
644 * @return the data staored for the key or NULL if the key isn't found
646 void *afb_session_get_cookie(struct afb_session *session, const void *key)
648 return afb_session_cookie(session, key, NULL, NULL, NULL, 0);
652 * Set the cookie of 'key' in the 'session' to the 'value' that can be
653 * cleaned using 'freecb' (if not null).
655 * @param session the session to set
656 * @param key the key of the data to store
657 * @param value the value to store at key
658 * @param freecb a function to use when the cookie value is to remove (or null)
660 * @return 0 in case of success or -1 in case of error
662 int afb_session_set_cookie(struct afb_session *session, const void *key, void *value, void (*freecb)(void*))
664 return -(value != afb_session_cookie(session, key, NULL, freecb, value, 1));
668 * Set the language attached to the session
670 * @param session the session to set
671 * @param lang the language specifiction to set to session
673 * @return 0 in case of success or -1 in case of error
675 int afb_session_set_language(struct afb_session *session, const char *lang)
683 oldl = session->lang;
684 session->lang = newl;
690 * Get the language attached to the session
692 * @param session the session to query
693 * @param lang a default language specifiction
695 * @return the langauage specification to use for session
697 const char *afb_session_get_language(struct afb_session *session, const char *lang)
699 return session->lang ?: lang;