2 * Copyright (C) 2015, 2016, 2017 "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.
25 #include <uuid/uuid.h>
29 #include <json-c/json.h>
31 #include "afb-session.h"
35 #define COOKEYMASK (COOKEYCOUNT - 1)
37 #define NOW (time(NULL))
44 void (*freecb)(void*);
51 time_t expiration; // expiration time of the token
53 pthread_mutex_t mutex;
54 char uuid[37]; // long term authentication of remote client
55 char token[37]; // short term authentication of remote client
56 struct cookie *cookies[COOKEYCOUNT];
59 // Session UUID are store in a simple array [for 10 sessions this should be enough]
61 pthread_mutex_t mutex; // declare a mutex to protect hash table
62 struct afb_session **store; // sessions store
63 int count; // current number of sessions
70 * Get the index of the 'key' in the cookies array.
71 * @param key the key to scan
72 * @return the index of the list for key within cookies
74 static int cookeyidx(const void *key)
76 intptr_t x = (intptr_t)key;
77 unsigned r = (unsigned)((x >> 5) ^ (x >> 15));
78 return r & COOKEYMASK;
82 static void new_uuid(char uuid[37])
85 uuid_generate(newuuid);
86 uuid_unparse_lower(newuuid, uuid);
89 static inline void lock(struct afb_session *session)
91 pthread_mutex_lock(&session->mutex);
94 static inline void unlock(struct afb_session *session)
96 pthread_mutex_unlock(&session->mutex);
99 // Free context [XXXX Should be protected again memory abort XXXX]
100 static void remove_all_cookies(struct afb_session *session)
103 struct cookie *cookie, *next;
106 for (idx = 0 ; idx < COOKEYCOUNT ; idx++) {
107 cookie = session->cookies[idx];
108 session->cookies[idx] = NULL;
109 while (cookie != NULL) {
111 if (cookie->freecb != NULL)
112 cookie->freecb(cookie->value);
119 // Create a new store in RAM, not that is too small it will be automatically extended
120 void afb_session_init (int max_session_count, int timeout, const char *initok)
122 // let's create as store as hashtable does not have any
123 sessions.store = calloc (1 + (unsigned)max_session_count, sizeof *sessions.store);
124 pthread_mutex_init(&sessions.mutex, NULL);
125 sessions.max = max_session_count;
126 sessions.timeout = timeout;
128 /* without token, a secret is made to forbid creation of sessions */
129 new_uuid(sessions.initok);
130 else if (strlen(initok) < sizeof(sessions.store[0]->token))
131 strcpy(sessions.initok, initok);
133 ERROR("initial token '%s' too long (max length 36)", initok);
138 const char *afb_session_initial_token()
140 return sessions.initok;
143 static struct afb_session *search (const char* uuid)
146 struct afb_session *session;
148 assert (uuid != NULL);
150 pthread_mutex_lock(&sessions.mutex);
152 for (idx=0; idx < sessions.max; idx++) {
153 session = sessions.store[idx];
154 if (session && (0 == strcmp (uuid, session->uuid)))
160 pthread_mutex_unlock(&sessions.mutex);
164 static int destroy (struct afb_session *session)
169 assert (session != NULL);
171 pthread_mutex_lock(&sessions.mutex);
173 for (idx=0; idx < sessions.max; idx++) {
174 if (sessions.store[idx] == session) {
175 sessions.store[idx] = NULL;
183 pthread_mutex_unlock(&sessions.mutex);
187 static int add (struct afb_session *session)
192 assert (session != NULL);
194 pthread_mutex_lock(&sessions.mutex);
196 for (idx=0; idx < sessions.max; idx++) {
197 if (NULL == sessions.store[idx]) {
198 sessions.store[idx] = session;
206 pthread_mutex_unlock(&sessions.mutex);
210 // Check if context timeout or not
211 static int is_expired (struct afb_session *ctx, time_t now)
213 assert (ctx != NULL);
214 return ctx->expiration < now;
217 // Check if context is active or not
218 static int is_active (struct afb_session *ctx, time_t now)
220 assert (ctx != NULL);
221 return ctx->uuid[0] != 0 && ctx->expiration >= now;
224 // Loop on every entry and remove old context sessions.hash
225 static void cleanup (time_t now)
227 struct afb_session *ctx;
230 // Loop on Sessions Table and remove anything that is older than timeout
231 for (idx=0; idx < sessions.max; idx++) {
232 ctx = sessions.store[idx];
233 if (ctx != NULL && is_expired(ctx, now)) {
234 afb_session_close (ctx);
239 static struct afb_session *make_session (const char *uuid, int timeout, time_t now)
241 struct afb_session *session;
243 if (!AFB_SESSION_TIMEOUT_IS_VALID(timeout)
244 || (uuid && strlen(uuid) >= sizeof session->uuid)) {
249 /* allocates a new one */
250 session = calloc(1, sizeof *session);
251 if (session == NULL) {
255 pthread_mutex_init(&session->mutex, NULL);
257 /* generate the uuid */
259 do { new_uuid(session->uuid); } while(search(session->uuid));
261 strcpy(session->uuid, uuid);
265 strcpy(session->token, sessions.initok);
268 if (timeout == AFB_SESSION_TIMEOUT_DEFAULT)
269 timeout = sessions.timeout;
270 session->timeout = timeout;
271 session->expiration = now + timeout;
272 if (timeout == AFB_SESSION_TIMEOUT_INFINITE || session->expiration < 0) {
273 session->expiration = (time_t)(~(time_t)0);
274 if (session->expiration < 0)
275 session->expiration = (time_t)(((unsigned long long)session->expiration) >> 1);
277 if (!add (session)) {
282 session->access = now;
283 session->refcount = 1;
292 /* Creates a new session with 'timeout' */
293 struct afb_session *afb_session_create (int timeout)
301 return make_session(NULL, timeout, now);
304 /* Searchs the session of 'uuid' */
305 struct afb_session *afb_session_search (const char *uuid)
308 struct afb_session *session;
313 session = search(uuid);
318 /* This function will return exiting session or newly created session */
319 struct afb_session *afb_session_get (const char *uuid, int timeout, int *created)
321 struct afb_session *session;
328 /* search for an existing one not too old */
330 session = search(uuid);
331 if (session != NULL) {
334 session->access = now;
340 /* no existing session found, create it */
341 session = make_session(uuid, timeout, now);
343 *created = !!session;
348 struct afb_session *afb_session_addref(struct afb_session *session)
351 __atomic_add_fetch(&session->refcount, 1, __ATOMIC_RELAXED);
355 void afb_session_unref(struct afb_session *session)
357 if (session != NULL) {
358 assert(session->refcount != 0);
359 if (!__atomic_sub_fetch(&session->refcount, 1, __ATOMIC_RELAXED)) {
360 if (session->uuid[0] == 0) {
362 pthread_mutex_destroy(&session->mutex);
369 // Free Client Session Context
370 void afb_session_close (struct afb_session *session)
372 assert(session != NULL);
373 if (session->uuid[0] != 0) {
374 session->uuid[0] = 0;
375 remove_all_cookies(session);
376 if (session->refcount == 0) {
383 // Sample Generic Ping Debug API
384 int afb_session_check_token (struct afb_session *session, const char *token)
386 assert(session != NULL);
387 assert(token != NULL);
389 // compare current token with previous one
390 if (!is_active (session, NOW))
393 if (session->token[0] && strcmp (token, session->token) != 0)
399 // generate a new token and update client context
400 void afb_session_new_token (struct afb_session *session)
402 assert(session != NULL);
404 // Old token was valid let's regenerate a new one
405 new_uuid(session->token);
407 // keep track of time for session timeout and further clean up
408 if (session->timeout != 0)
409 session->expiration = NOW + session->timeout;
412 /* Returns the uuid of 'session' */
413 const char *afb_session_uuid (struct afb_session *session)
415 assert(session != NULL);
416 return session->uuid;
419 /* Returns the token of 'session' */
420 const char *afb_session_token (struct afb_session *session)
422 assert(session != NULL);
423 return session->token;
426 /* Set, get, replace, remove a cookie key */
427 void *afb_session_cookie(struct afb_session *session, const void *key, void *(*makecb)(void *closure), void (*freecb)(void *item), void *closure, int replace)
431 struct cookie *cookie;
433 idx = cookeyidx(key);
435 cookie = session->cookies[idx];
438 value = makecb ? makecb(closure) : closure;
439 if (replace || makecb || freecb) {
440 cookie = malloc(sizeof *cookie);
448 cookie->value = value;
449 cookie->freecb = freecb;
450 cookie->next = session->cookies[idx];
451 session->cookies[idx] = cookie;
455 } else if (cookie->key == key) {
457 value = cookie->value;
459 value = makecb ? makecb(closure) : closure;
460 if (cookie->value != value && cookie->freecb)
461 cookie->freecb(cookie->value);
462 cookie->value = value;
463 cookie->freecb = freecb;
467 cookie = cookie->next;
474 void *afb_session_get_cookie(struct afb_session *session, const void *key)
476 return afb_session_cookie(session, key, NULL, NULL, NULL, 0);
479 int afb_session_set_cookie(struct afb_session *session, const void *key, void *value, void (*freecb)(void*))
481 return -(value != afb_session_cookie(session, key, NULL, freecb, value, 1));