3 ## Structure for declaring binding
5 ### struct afb_binding_v2
7 The main structure, of type **afb_binding_v2**, for describing the binding
8 must be exported under the name **afbBindingV2**.
10 This structure is defined as below.
14 * Description of the bindings of type version 2
18 const char *api; /* api name for the binding */
19 const char *specification; /* textual openAPIv3 specification of the binding */
20 const char *info; /* some info about the api, can be NULL */
21 const struct afb_verb_v2 *verbs; /* array of descriptions of verbs terminated by a NULL name */
22 int (*preinit)(); /* callback at load of the binding */
23 int (*init)(); /* callback for starting the service */
24 void (*onevent)(const char *event, struct json_object *object); /* callback for handling events */
25 unsigned noconcurrency: 1; /* avoids concurrent requests to verbs */
29 ### struct afb_verb_v2
31 Each verb is described with a structure of type **afb_verb_v2**
36 * Description of one verb of the API provided by the binding
37 * This enumeration is valid for bindings of type version 2
41 const char *verb; /* name of the verb */
42 void (*callback)(struct afb_req req); /* callback function implementing the verb */
43 const struct afb_auth *auth; /* required authorization */
44 const char *info; /* some info about the verb, can be NULL */
45 uint32_t session; /* authorization and session requirements of the verb */
49 The **session** flags is one of the constant defined below:
51 - AFB_SESSION_NONE : no flag, synonym to 0
52 - AFB_SESSION_LOA_0 : Requires the LOA to be 0 or more, synonym to 0 or AFB_SESSION_NONE
53 - AFB_SESSION_LOA_1 : Requires the LOA to be 1 or more
54 - AFB_SESSION_LOA_2 : Requires the LOA to be 2 or more
55 - AFB_SESSION_LOA_3 : Requires the LOA to be 3 or more
56 - AFB_SESSION_CHECK : Requires the token to be set and valid
57 - AFB_SESSION_REFRESH : Implies a token refresh
58 - AFB_SESSION_CLOSE : Implies cloing the session
60 The LOA (Level Of Assurance) is set, by binding, using the function **afb_req_session_set_LOA**.
62 ### struct afb_auth and enum afb_auth_type
64 The structure **afb_auth** is used within verb description to
65 set security requirements.
66 The interpretation of the structure depends on the value of the field **type**.
71 const enum afb_auth_type type;
75 const struct afb_auth *first;
77 const struct afb_auth *next;
81 The possible values for **type** is defined here:
85 * Enum for Session/Token/Assurance middleware.
89 afb_auth_No = 0, /** never authorized, no data */
90 afb_auth_Token, /** authorized if token valid, no data */
91 afb_auth_LOA, /** authorized if LOA greater than data 'loa' */
92 afb_auth_Permission, /** authorized if permission 'text' is granted */
93 afb_auth_Or, /** authorized if 'first' or 'next' is authorized */
94 afb_auth_And, /** authorized if 'first' and 'next' are authorized */
95 afb_auth_Not, /** authorized if 'first' is not authorized */
96 afb_auth_Yes /** always authorized, no data */
103 static const struct afb_auth _afb_auths_v2_monitor[] = {
104 { .type = afb_auth_Permission, .text = "urn:AGL:permission:monitor:public:set" },
105 { .type = afb_auth_Permission, .text = "urn:AGL:permission:monitor:public:get" },
106 { .type = afb_auth_Or, .first = &_afb_auths_v2_monitor[1], .next = &_afb_auths_v2_monitor[0] }
110 ## Functions of class afb_daemon
112 The 3 following functions are linked to libsystemd.
113 They allow use of **sd_event** features and access
114 to **sd_bus** features.
118 * Retrieves the common systemd's event loop of AFB
120 struct sd_event *afb_daemon_get_event_loop();
123 * Retrieves the common systemd's user/session d-bus of AFB
125 struct sd_bus *afb_daemon_get_user_bus();
128 * Retrieves the common systemd's system d-bus of AFB
130 struct sd_bus *afb_daemon_get_system_bus();
133 The 2 following functions are linked to event management.
134 Broadcasting an event send it to any possible listener.
138 * Broadcasts widely the event of 'name' with the data 'object'.
139 * 'object' can be NULL.
141 * For convenience, the function calls 'json_object_put' for 'object'.
142 * Thus, in the case where 'object' should remain available after
143 * the function returns, the function 'json_object_get' shall be used.
145 * Returns the count of clients that received the event.
147 int afb_daemon_broadcast_event(const char *name, struct json_object *object);
150 * Creates an event of 'name' and returns it.
152 * See afb_event_is_valid to check if there is an error.
154 struct afb_event afb_daemon_make_event(const char *name);
157 The following function is used by logging macros and should normally
159 Instead, you should use the macros:
169 * Send a message described by 'fmt' and following parameters
170 * to the journal for the verbosity 'level'.
172 * 'file', 'line' and 'func' are indicators of position of the code in source files
173 * (see macros __FILE__, __LINE__ and __func__).
175 * 'level' is defined by syslog standard:
176 * EMERGENCY 0 System is unusable
177 * ALERT 1 Action must be taken immediately
178 * CRITICAL 2 Critical conditions
179 * ERROR 3 Error conditions
180 * WARNING 4 Warning conditions
181 * NOTICE 5 Normal but significant condition
182 * INFO 6 Informational
183 * DEBUG 7 Debug-level messages
185 void afb_daemon_verbose(int level, const char *file, int line, const char * func, const char *fmt, ...);
188 The 2 following functions MUST be used to access data of the bindings.
192 * Get the root directory file descriptor. This file descriptor can
193 * be used with functions 'openat', 'fstatat', ...
195 int afb_daemon_rootdir_get_fd();
198 * Opens 'filename' within the root directory with 'flags' (see function openat)
199 * using the 'locale' definition (example: "jp,en-US") that can be NULL.
200 * Returns the file descriptor or -1 in case of error.
202 int afb_daemon_rootdir_open_locale(const char *filename, int flags, const char *locale);
205 The following function is used to queue jobs.
209 * Queue the job defined by 'callback' and 'argument' for being executed asynchronously
210 * in this thread (later) or in an other thread.
211 * If 'group' is not NUL, the jobs queued with a same value (as the pointer value 'group')
212 * are executed in sequence in the order of there submission.
213 * If 'timeout' is not 0, it represent the maximum execution time for the job in seconds.
214 * At first, the job is called with 0 as signum and the given argument.
215 * The job is executed with the monitoring of its time and some signals like SIGSEGV and
216 * SIGFPE. When a such signal is catched, the job is terminated and re-executed but with
217 * signum being the signal number (SIGALRM when timeout expired).
219 * Returns 0 in case of success or -1 in case of error.
221 int afb_daemon_queue_job(void (*callback)(int signum, void *arg), void *argument, void *group, int timeout)
224 The following function must be used when a binding depends on other
225 bindings at its initialization.
229 * Tells that it requires the API of "name" to exist
230 * and if 'initialized' is not null to be initialized.
231 * Returns 0 in case of success or -1 in case of error.
233 int afb_daemon_require_api(const char *name, int initialized)
236 ## Functions of class afb_service
238 The following functions allow services to call verbs of other
239 bindings for themselves.
243 * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
244 * The result of the call is delivered to the 'callback' function with the 'callback_closure'.
246 * For convenience, the function calls 'json_object_put' for 'args'.
247 * Thus, in the case where 'args' should remain available after
248 * the function returns, the function 'json_object_get' shall be used.
250 * The 'callback' receives 3 arguments:
251 * 1. 'closure' the user defined closure pointer 'callback_closure',
252 * 2. 'status' a status being 0 on success or negative when an error occured,
253 * 2. 'result' the resulting data as a JSON object.
255 * @param api The api name of the method to call
256 * @param verb The verb name of the method to call
257 * @param args The arguments to pass to the method
258 * @param callback The to call on completion
259 * @param callback_closure The closure to pass to the callback
261 * @see also 'afb_req_subcall'
263 void afb_service_call(
266 struct json_object *args,
267 void (*callback)(void*closure, int status, struct json_object *result),
268 void *callback_closure);
271 * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
272 * 'result' will receive the response.
274 * For convenience, the function calls 'json_object_put' for 'args'.
275 * Thus, in the case where 'args' should remain available after
276 * the function returns, the function 'json_object_get' shall be used.
278 * @param api The api name of the method to call
279 * @param verb The verb name of the method to call
280 * @param args The arguments to pass to the method
281 * @param result Where to store the result - should call json_object_put on it -
283 * @returns 0 in case of success or a negative value in case of error.
285 * @see also 'afb_req_subcall'
287 int afb_service_call_sync(
290 struct json_object *args,
291 struct json_object **result);
294 ## Functions of class afb_event
296 This function checks whether the event is valid.
297 It must be used when creating events.
301 * Checks wether the 'event' is valid or not.
303 * Returns 0 if not valid or 1 if valid.
305 int afb_event_is_valid(struct afb_event event);
308 The two following functions are used to broadcast or push
313 * Broadcasts widely the 'event' with the data 'object'.
314 * 'object' can be NULL.
316 * For convenience, the function calls 'json_object_put' for 'object'.
317 * Thus, in the case where 'object' should remain available after
318 * the function returns, the function 'json_object_get' shall be used.
320 * Returns the count of clients that received the event.
322 int afb_event_broadcast(struct afb_event event, struct json_object *object);
325 * Pushes the 'event' with the data 'object' to its observers.
326 * 'object' can be NULL.
328 * For convenience, the function calls 'json_object_put' for 'object'.
329 * Thus, in the case where 'object' should remain available after
330 * the function returns, the function 'json_object_get' shall be used.
332 * Returns the count of clients that received the event.
334 int afb_event_push(struct afb_event event, struct json_object *object);
337 The following function destiys the event.
341 * Drops the data associated to the 'event'
342 * After calling this function, the event
343 * MUST NOT BE USED ANYMORE.
345 void afb_event_drop(struct afb_event event);
348 This function allows to retrieve the exact name of the event.
352 * Gets the name associated to the 'event'.
354 const char *afb_event_name(struct afb_event event);
357 ## Functions of class afb_req
359 This function checks the validity of the **req**.
363 * Checks wether the request 'req' is valid or not.
365 * Returns 0 if not valid or 1 if valid.
367 int afb_req_is_valid(struct afb_req req);
370 The following functions retrieves parameters of the request.
374 * Gets from the request 'req' the argument of 'name'.
375 * Returns a PLAIN structure of type 'struct afb_arg'.
376 * When the argument of 'name' is not found, all fields of result are set to NULL.
377 * When the argument of 'name' is found, the fields are filled,
378 * in particular, the field 'result.name' is set to 'name'.
380 * There is a special name value: the empty string.
381 * The argument of name "" is defined only if the request was made using
382 * an HTTP POST of Content-Type "application/json". In that case, the
383 * argument of name "" receives the value of the body of the HTTP request.
385 struct afb_arg afb_req_get(struct afb_req req, const char *name);
388 * Gets from the request 'req' the string value of the argument of 'name'.
389 * Returns NULL if when there is no argument of 'name'.
390 * Returns the value of the argument of 'name' otherwise.
392 * Shortcut for: afb_req_get(req, name).value
394 const char *afb_req_value(struct afb_req req, const char *name);
397 * Gets from the request 'req' the path for file attached to the argument of 'name'.
398 * Returns NULL if when there is no argument of 'name' or when there is no file.
399 * Returns the path of the argument of 'name' otherwise.
401 * Shortcut for: afb_req_get(req, name).path
403 const char *afb_req_path(struct afb_req req, const char *name);
406 * Gets from the request 'req' the json object hashing the arguments.
407 * The returned object must not be released using 'json_object_put'.
409 struct json_object *afb_req_json(struct afb_req req);
412 The following functions emit the reply to the request.
416 * Sends a reply of kind success to the request 'req'.
417 * The status of the reply is automatically set to "success".
418 * Its send the object 'obj' (can be NULL) with an
419 * informationnal comment 'info (can also be NULL).
421 * For convenience, the function calls 'json_object_put' for 'obj'.
422 * Thus, in the case where 'obj' should remain available after
423 * the function returns, the function 'json_object_get' shall be used.
425 void afb_req_success(struct afb_req req, struct json_object *obj, const char *info);
428 * Same as 'afb_req_success' but the 'info' is a formatting
429 * string followed by arguments.
431 * For convenience, the function calls 'json_object_put' for 'obj'.
432 * Thus, in the case where 'obj' should remain available after
433 * the function returns, the function 'json_object_get' shall be used.
435 void afb_req_success_f(struct afb_req req, struct json_object *obj, const char *info, ...);
438 * Same as 'afb_req_success_f' but the arguments to the format 'info'
439 * are given as a variable argument list instance.
441 * For convenience, the function calls 'json_object_put' for 'obj'.
442 * Thus, in the case where 'obj' should remain available after
443 * the function returns, the function 'json_object_get' shall be used.
445 void afb_req_success_v(struct afb_req req, struct json_object *obj, const char *info, va_list args);
448 * Sends a reply of kind failure to the request 'req'.
449 * The status of the reply is set to 'status' and an
450 * informationnal comment 'info' (can also be NULL) can be added.
452 * Note that calling afb_req_fail("success", info) is equivalent
453 * to call afb_req_success(NULL, info). Thus even if possible it
454 * is strongly recommended to NEVER use "success" for status.
456 void afb_req_fail(struct afb_req req, const char *status, const char *info);
459 * Same as 'afb_req_fail' but the 'info' is a formatting
460 * string followed by arguments.
462 void afb_req_fail_f(struct afb_req req, const char *status, const char *info, ...);
465 * Same as 'afb_req_fail_f' but the arguments to the format 'info'
466 * are given as a variable argument list instance.
468 void afb_req_fail_v(struct afb_req req, const char *status, const char *info, va_list args);
471 The following functions handle the session data.
475 * Gets the pointer stored by the binding for the session of 'req'.
476 * When the binding has not yet recorded a pointer, NULL is returned.
478 void *afb_req_context_get(struct afb_req req);
481 * Stores for the binding the pointer 'context' to the session of 'req'.
482 * The function 'free_context' will be called when the session is closed
483 * or if binding stores an other pointer.
485 void afb_req_context_set(struct afb_req req, void *context, void (*free_context)(void*));
488 * Gets the pointer stored by the binding for the session of 'req'.
489 * If the stored pointer is NULL, indicating that no pointer was
490 * already stored, afb_req_context creates a new context by calling
491 * the function 'create_context' and stores it with the freeing function
494 void *afb_req_context(struct afb_req req, void *(*create_context)(), void (*free_context)(void*));
497 * Frees the pointer stored by the binding for the session of 'req'
498 * and sets it to NULL.
500 * Shortcut for: afb_req_context_set(req, NULL, NULL)
502 void afb_req_context_clear(struct afb_req req);
505 * Closes the session associated with 'req'
506 * and delete all associated contexts.
508 void afb_req_session_close(struct afb_req req);
511 * Sets the level of assurance of the session of 'req'
512 * to 'level'. The effect of this function is subject of
514 * Returns 1 on success or 0 if failed.
516 int afb_req_session_set_LOA(struct afb_req req, unsigned level);
519 The 4 following functions must be used for asynchronous handling requests.
523 * Adds one to the count of references of 'req'.
524 * This function MUST be called by asynchronous implementations
525 * of verbs if no reply was sent before returning.
527 void afb_req_addref(struct afb_req req);
530 * Substracts one to the count of references of 'req'.
531 * This function MUST be called by asynchronous implementations
532 * of verbs after sending the asynchronous reply.
534 void afb_req_unref(struct afb_req req);
537 * Stores 'req' on heap for asynchronous use.
538 * Returns a handler to the stored 'req' or NULL on memory depletion.
539 * The count of reference to 'req' is incremented on success
540 * (see afb_req_addref).
542 struct afb_stored_req *afb_req_store(struct afb_req req);
545 * Retrieves the afb_req stored at 'sreq'.
546 * Returns the stored request.
547 * The count of reference is UNCHANGED, thus, the
548 * function 'afb_req_unref' should be called on the result
549 * after that the asynchronous reply if sent.
551 struct afb_req afb_req_unstore(struct afb_stored_req *sreq);
554 The two following functions are used to associate client with events
559 * Establishes for the client link identified by 'req' a subscription
561 * Returns 0 in case of successful subscription or -1 in case of error.
563 int afb_req_subscribe(struct afb_req req, struct afb_event event);
566 * Revokes the subscription established to the 'event' for the client
567 * link identified by 'req'.
568 * Returns 0 in case of successful subscription or -1 in case of error.
570 int afb_req_unsubscribe(struct afb_req req, struct afb_event event);
573 The following functions must be used to make request in the name of the
574 client (with its permissions).
578 * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
579 * This call is made in the context of the request 'req'.
580 * On completion, the function 'callback' is invoked with the
581 * 'closure' given at call and two other parameters: 'iserror' and 'result'.
582 * 'status' is 0 on success or negative when on an error reply.
583 * 'result' is the json object of the reply, you must not call json_object_put
586 * For convenience, the function calls 'json_object_put' for 'args'.
587 * Thus, in the case where 'args' should remain available after
588 * the function returns, the function 'json_object_get' shall be used.
591 * - 'afb_req_subcall_req' that is convenient to keep request alive automatically.
592 * - 'afb_req_subcall_sync' the synchronous version
594 void afb_req_subcall(
598 struct json_object *args,
599 void (*callback)(void *closure, int status, struct json_object *result),
603 * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
604 * This call is made in the context of the request 'req'.
605 * On completion, the function 'callback' is invoked with the
606 * original request 'req', the 'closure' given at call and two
607 * other parameters: 'iserror' and 'result'.
608 * 'status' is 0 on success or negative when on an error reply.
609 * 'result' is the json object of the reply, you must not call json_object_put
612 * For convenience, the function calls 'json_object_put' for 'args'.
613 * Thus, in the case where 'args' should remain available after
614 * the function returns, the function 'json_object_get' shall be used.
617 * - 'afb_req_subcall' that doesn't keep request alive automatically.
618 * - 'afb_req_subcall_sync' the synchronous version
620 static inline void afb_req_subcall_req(struct afb_req req, const char *api, const char *verb, struct json_object *args, void (*callback)(void *closure, int iserror, struct json_object *result, struct afb_req req), void *closure)
622 req.itf->subcall_req(req.closure, api, verb, args, callback, closure);
626 * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
627 * This call is made in the context of the request 'req'.
628 * This call is synchronous, it waits untill completion of the request.
629 * It returns 0 on success or a negative value on error answer.
630 * The object pointed by 'result' is filled and must be released by the caller
631 * after its use by calling 'json_object_put'.
633 * For convenience, the function calls 'json_object_put' for 'args'.
634 * Thus, in the case where 'args' should remain available after
635 * the function returns, the function 'json_object_get' shall be used.
638 * - 'afb_req_subcall_req' that is convenient to keep request alive automatically.
639 * - 'afb_req_subcall' that doesn't keep request alive automatically.
641 int afb_req_subcall_sync(
645 struct json_object *args,
646 struct json_object **result);
649 The following function is used by logging macros and should normally
651 Instead, you should use the macros:
654 - **AFB_REQ_WARNING**
661 * Send associated to 'req' a message described by 'fmt' and following parameters
662 * to the journal for the verbosity 'level'.
664 * 'file', 'line' and 'func' are indicators of position of the code in source files
665 * (see macros __FILE__, __LINE__ and __func__).
667 * 'level' is defined by syslog standard:
668 * EMERGENCY 0 System is unusable
669 * ALERT 1 Action must be taken immediately
670 * CRITICAL 2 Critical conditions
671 * ERROR 3 Error conditions
672 * WARNING 4 Warning conditions
673 * NOTICE 5 Normal but significant condition
674 * INFO 6 Informational
675 * DEBUG 7 Debug-level messages
677 void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...);
682 The following macros must be used for logging:
692 The following macros can be used for logging in the context
693 of a request **req** of type **afb_req**:
696 AFB_REQ_ERROR(req,fmt,...)
697 AFB_REQ_WARNING(req,fmt,...)
698 AFB_REQ_NOTICE(req,fmt,...)
699 AFB_REQ_INFO(req,fmt,...)
700 AFB_REQ_DEBUG(req,fmt,...)
703 By default, the logging macros add file, line and function