1 [LEGACY] Binding Reference
2 ==========================
4 # Structure for declaring binding
5 ---------------------------------
7 ### struct afb_binding_v2
9 The main structure, of type **afb_binding_v2**, for describing the binding
10 must be exported under the name **afbBindingV2**.
12 This structure is defined as below.
16 * Description of the bindings of type version 2
20 const char *api; /* api name for the binding */
21 const char *specification; /* textual openAPIv3 specification of the binding */
22 const char *info; /* some info about the api, can be NULL */
23 const struct afb_verb_v2 *verbs; /* array of descriptions of verbs terminated by a NULL name */
24 int (*preinit)(); /* callback at load of the binding */
25 int (*init)(); /* callback for starting the service */
26 void (*onevent)(const char *event, struct json_object *object); /* callback for handling events */
27 unsigned noconcurrency: 1; /* avoids concurrent requests to verbs */
31 ### struct afb_verb_v2
33 Each verb is described with a structure of type **afb_verb_v2**
38 * Description of one verb of the API provided by the binding
39 * This enumeration is valid for bindings of type version 2
43 const char *verb; /* name of the verb */
44 void (*callback)(struct afb_req req); /* callback function implementing the verb */
45 const struct afb_auth *auth; /* required authorization */
46 const char *info; /* some info about the verb, can be NULL */
47 uint32_t session; /* authorization and session requirements of the verb */
51 The **session** flags is one of the constant defined below:
53 - AFB_SESSION_NONE : no flag, synonym to 0
54 - AFB_SESSION_LOA_0 : Requires the LOA to be 0 or more, synonym to 0 or AFB_SESSION_NONE
55 - AFB_SESSION_LOA_1 : Requires the LOA to be 1 or more
56 - AFB_SESSION_LOA_2 : Requires the LOA to be 2 or more
57 - AFB_SESSION_LOA_3 : Requires the LOA to be 3 or more
58 - AFB_SESSION_CHECK : Requires the token to be set and valid
59 - AFB_SESSION_REFRESH : Implies a token refresh
60 - AFB_SESSION_CLOSE : Implies cloing the session
62 The LOA (Level Of Assurance) is set, by binding, using the function **afb_req_session_set_LOA**.
64 ### struct afb_auth and enum afb_auth_type
66 The structure **afb_auth** is used within verb description to
67 set security requirements.
68 The interpretation of the structure depends on the value of the field **type**.
73 const enum afb_auth_type type;
77 const struct afb_auth *first;
79 const struct afb_auth *next;
83 The possible values for **type** is defined here:
87 * Enum for Session/Token/Assurance middleware.
91 afb_auth_No = 0, /** never authorized, no data */
92 afb_auth_Token, /** authorized if token valid, no data */
93 afb_auth_LOA, /** authorized if LOA greater than data 'loa' */
94 afb_auth_Permission, /** authorized if permission 'text' is granted */
95 afb_auth_Or, /** authorized if 'first' or 'next' is authorized */
96 afb_auth_And, /** authorized if 'first' and 'next' are authorized */
97 afb_auth_Not, /** authorized if 'first' is not authorized */
98 afb_auth_Yes /** always authorized, no data */
105 static const struct afb_auth _afb_auths_v2_monitor[] = {
106 { .type = afb_auth_Permission, .text = "urn:AGL:permission:monitor:public:set" },
107 { .type = afb_auth_Permission, .text = "urn:AGL:permission:monitor:public:get" },
108 { .type = afb_auth_Or, .first = &_afb_auths_v2_monitor[1], .next = &_afb_auths_v2_monitor[0] }
112 ## Functions of class afb_daemon
114 The 3 following functions are linked to libsystemd.
115 They allow use of **sd_event** features and access
116 to **sd_bus** features.
120 * Retrieves the common systemd's event loop of AFB
122 struct sd_event *afb_daemon_get_event_loop();
125 * Retrieves the common systemd's user/session d-bus of AFB
127 struct sd_bus *afb_daemon_get_user_bus();
130 * Retrieves the common systemd's system d-bus of AFB
132 struct sd_bus *afb_daemon_get_system_bus();
135 The 2 following functions are linked to event management.
136 Broadcasting an event send it to any possible listener.
140 * Broadcasts widely the event of 'name' with the data 'object'.
141 * 'object' can be NULL.
143 * For convenience, the function calls 'json_object_put' for 'object'.
144 * Thus, in the case where 'object' should remain available after
145 * the function returns, the function 'json_object_get' shall be used.
147 * Calling this function is only forbidden during preinit.
149 * Returns the count of clients that received the event.
151 int afb_daemon_broadcast_event(const char *name, struct json_object *object);
154 * Creates an event of 'name' and returns it.
156 * Calling this function is only forbidden during preinit.
158 * See afb_event_is_valid to check if there is an error.
160 struct afb_event afb_daemon_make_event(const char *name);
163 The following function is used by logging macros and should normally
165 Instead, you should use the macros:
175 * Send a message described by 'fmt' and following parameters
176 * to the journal for the verbosity 'level'.
178 * 'file', 'line' and 'func' are indicators of position of the code in source files
179 * (see macros __FILE__, __LINE__ and __func__).
181 * 'level' is defined by syslog standard:
182 * EMERGENCY 0 System is unusable
183 * ALERT 1 Action must be taken immediately
184 * CRITICAL 2 Critical conditions
185 * ERROR 3 Error conditions
186 * WARNING 4 Warning conditions
187 * NOTICE 5 Normal but significant condition
188 * INFO 6 Informational
189 * DEBUG 7 Debug-level messages
191 void afb_daemon_verbose(int level, const char *file, int line, const char * func, const char *fmt, ...);
194 The 2 following functions MUST be used to access data of the bindings.
198 * Get the root directory file descriptor. This file descriptor can
199 * be used with functions 'openat', 'fstatat', ...
201 int afb_daemon_rootdir_get_fd();
204 * Opens 'filename' within the root directory with 'flags' (see function openat)
205 * using the 'locale' definition (example: "jp,en-US") that can be NULL.
206 * Returns the file descriptor or -1 in case of error.
208 int afb_daemon_rootdir_open_locale(const char *filename, int flags, const char *locale);
211 The following function is used to queue jobs.
215 * Queue the job defined by 'callback' and 'argument' for being executed asynchronously
216 * in this thread (later) or in an other thread.
217 * If 'group' is not NUL, the jobs queued with a same value (as the pointer value 'group')
218 * are executed in sequence in the order of there submission.
219 * If 'timeout' is not 0, it represent the maximum execution time for the job in seconds.
220 * At first, the job is called with 0 as signum and the given argument.
221 * The job is executed with the monitoring of its time and some signals like SIGSEGV and
222 * SIGFPE. When a such signal is catched, the job is terminated and re-executed but with
223 * signum being the signal number (SIGALRM when timeout expired).
225 * Returns 0 in case of success or -1 in case of error.
227 int afb_daemon_queue_job(void (*callback)(int signum, void *arg), void *argument, void *group, int timeout)
230 The following function must be used when a binding depends on other
231 bindings at its initialization.
235 * Tells that it requires the API of "name" to exist
236 * and if 'initialized' is not null to be initialized.
237 * Calling this function is only allowed within init.
238 * Returns 0 in case of success or -1 in case of error.
240 int afb_daemon_require_api(const char *name, int initialized)
243 This function allows to give a different name to the binding.
244 It can be called during pre-init.
248 * Set the name of the API to 'name'.
249 * Calling this function is only allowed within preinit.
250 * Returns 0 in case of success or -1 in case of error.
252 int afb_daemon_rename_api(const char *name);
255 ## Functions of class afb_service
257 The following functions allow services to call verbs of other
258 bindings for themselves.
262 * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
263 * The result of the call is delivered to the 'callback' function with the 'callback_closure'.
265 * For convenience, the function calls 'json_object_put' for 'args'.
266 * Thus, in the case where 'args' should remain available after
267 * the function returns, the function 'json_object_get' shall be used.
269 * The 'callback' receives 3 arguments:
270 * 1. 'closure' the user defined closure pointer 'callback_closure',
271 * 2. 'status' a status being 0 on success or negative when an error occurred,
272 * 2. 'result' the resulting data as a JSON object.
274 * @param api The api name of the method to call
275 * @param verb The verb name of the method to call
276 * @param args The arguments to pass to the method
277 * @param callback The to call on completion
278 * @param callback_closure The closure to pass to the callback
280 * @see also 'afb_req_subcall'
282 void afb_service_call(
285 struct json_object *args,
286 void (*callback)(void*closure, int status, struct json_object *result),
287 void *callback_closure);
290 * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
291 * 'result' will receive the response.
293 * For convenience, the function calls 'json_object_put' for 'args'.
294 * Thus, in the case where 'args' should remain available after
295 * the function returns, the function 'json_object_get' shall be used.
297 * @param api The api name of the method to call
298 * @param verb The verb name of the method to call
299 * @param args The arguments to pass to the method
300 * @param result Where to store the result - should call json_object_put on it -
302 * @returns 0 in case of success or a negative value in case of error.
304 * @see also 'afb_req_subcall'
306 int afb_service_call_sync(
309 struct json_object *args,
310 struct json_object **result);
313 ## Functions of class afb_event
315 This function checks whether the event is valid.
316 It must be used when creating events.
320 * Checks wether the 'event' is valid or not.
322 * Returns 0 if not valid or 1 if valid.
324 int afb_event_is_valid(struct afb_event event);
327 The two following functions are used to broadcast or push
332 * Broadcasts widely the 'event' with the data 'object'.
333 * 'object' can be NULL.
335 * For convenience, the function calls 'json_object_put' for 'object'.
336 * Thus, in the case where 'object' should remain available after
337 * the function returns, the function 'json_object_get' shall be used.
339 * Returns the count of clients that received the event.
341 int afb_event_broadcast(struct afb_event event, struct json_object *object);
344 * Pushes the 'event' with the data 'object' to its observers.
345 * 'object' can be NULL.
347 * For convenience, the function calls 'json_object_put' for 'object'.
348 * Thus, in the case where 'object' should remain available after
349 * the function returns, the function 'json_object_get' shall be used.
351 * Returns the count of clients that received the event.
353 int afb_event_push(struct afb_event event, struct json_object *object);
356 The following function destroys the event.
360 * Drops the data associated to the 'event'
361 * After calling this function, the event
362 * MUST NOT BE USED ANYMORE.
364 void afb_event_drop(struct afb_event event);
367 This function allows to retrieve the exact name of the event.
371 * Gets the name associated to the 'event'.
373 const char *afb_event_name(struct afb_event event);
376 ## Functions of class afb_req
378 This function checks the validity of the **req**.
382 * Checks wether the request 'req' is valid or not.
384 * Returns 0 if not valid or 1 if valid.
386 int afb_req_is_valid(struct afb_req req);
389 The following functions retrieves parameters of the request.
393 * Gets from the request 'req' the argument of 'name'.
394 * Returns a PLAIN structure of type 'struct afb_arg'.
395 * When the argument of 'name' is not found, all fields of result are set to NULL.
396 * When the argument of 'name' is found, the fields are filled,
397 * in particular, the field 'result.name' is set to 'name'.
399 * There is a special name value: the empty string.
400 * The argument of name "" is defined only if the request was made using
401 * an HTTP POST of Content-Type "application/json". In that case, the
402 * argument of name "" receives the value of the body of the HTTP request.
404 struct afb_arg afb_req_get(struct afb_req req, const char *name);
407 * Gets from the request 'req' the string value of the argument of 'name'.
408 * Returns NULL if when there is no argument of 'name'.
409 * Returns the value of the argument of 'name' otherwise.
411 * Shortcut for: afb_req_get(req, name).value
413 const char *afb_req_value(struct afb_req req, const char *name);
416 * Gets from the request 'req' the path for file attached to the argument of 'name'.
417 * Returns NULL if when there is no argument of 'name' or when there is no file.
418 * Returns the path of the argument of 'name' otherwise.
420 * Shortcut for: afb_req_get(req, name).path
422 const char *afb_req_path(struct afb_req req, const char *name);
425 * Gets from the request 'req' the json object hashing the arguments.
426 * The returned object must not be released using 'json_object_put'.
428 struct json_object *afb_req_json(struct afb_req req);
431 The following functions emit the reply to the request.
435 * Sends a reply of kind success to the request 'req'.
436 * The status of the reply is automatically set to "success".
437 * Its send the object 'obj' (can be NULL) with an
438 * informational comment 'info (can also be NULL).
440 * For convenience, the function calls 'json_object_put' for 'obj'.
441 * Thus, in the case where 'obj' should remain available after
442 * the function returns, the function 'json_object_get' shall be used.
444 void afb_req_success(struct afb_req req, struct json_object *obj, const char *info);
447 * Same as 'afb_req_success' but the 'info' is a formatting
448 * string followed by arguments.
450 * For convenience, the function calls 'json_object_put' for 'obj'.
451 * Thus, in the case where 'obj' should remain available after
452 * the function returns, the function 'json_object_get' shall be used.
454 void afb_req_success_f(struct afb_req req, struct json_object *obj, const char *info, ...);
457 * Same as 'afb_req_success_f' but the arguments to the format 'info'
458 * are given as a variable argument list instance.
460 * For convenience, the function calls 'json_object_put' for 'obj'.
461 * Thus, in the case where 'obj' should remain available after
462 * the function returns, the function 'json_object_get' shall be used.
464 void afb_req_success_v(struct afb_req req, struct json_object *obj, const char *info, va_list args);
467 * Sends a reply of kind failure to the request 'req'.
468 * The status of the reply is set to 'status' and an
469 * informational comment 'info' (can also be NULL) can be added.
471 * Note that calling afb_req_fail("success", info) is equivalent
472 * to call afb_req_success(NULL, info). Thus even if possible it
473 * is strongly recommended to NEVER use "success" for status.
475 void afb_req_fail(struct afb_req req, const char *status, const char *info);
478 * Same as 'afb_req_fail' but the 'info' is a formatting
479 * string followed by arguments.
481 void afb_req_fail_f(struct afb_req req, const char *status, const char *info, ...);
484 * Same as 'afb_req_fail_f' but the arguments to the format 'info'
485 * are given as a variable argument list instance.
487 void afb_req_fail_v(struct afb_req req, const char *status, const char *info, va_list args);
490 The following functions handle the session data.
494 * Gets the pointer stored by the binding for the session of 'req'.
495 * When the binding has not yet recorded a pointer, NULL is returned.
497 void *afb_req_context_get(struct afb_req req);
500 * Stores for the binding the pointer 'context' to the session of 'req'.
501 * The function 'free_context' will be called when the session is closed
502 * or if binding stores an other pointer.
504 void afb_req_context_set(struct afb_req req, void *context, void (*free_context)(void*));
507 * Gets the pointer stored by the binding for the session of 'req'.
508 * If the stored pointer is NULL, indicating that no pointer was
509 * already stored, afb_req_context creates a new context by calling
510 * the function 'create_context' and stores it with the freeing function
513 void *afb_req_context(struct afb_req req, void *(*create_context)(), void (*free_context)(void*));
516 * Frees the pointer stored by the binding for the session of 'req'
517 * and sets it to NULL.
519 * Shortcut for: afb_req_context_set(req, NULL, NULL)
521 void afb_req_context_clear(struct afb_req req);
524 * Closes the session associated with 'req'
525 * and delete all associated contexts.
527 void afb_req_session_close(struct afb_req req);
530 * Sets the level of assurance of the session of 'req'
531 * to 'level'. The effect of this function is subject of
533 * Returns 1 on success or 0 if failed.
535 int afb_req_session_set_LOA(struct afb_req req, unsigned level);
538 The 4 following functions must be used for asynchronous handling requests.
542 * Adds one to the count of references of 'req'.
543 * This function MUST be called by asynchronous implementations
544 * of verbs if no reply was sent before returning.
546 void afb_req_addref(struct afb_req req);
549 * Substracts one to the count of references of 'req'.
550 * This function MUST be called by asynchronous implementations
551 * of verbs after sending the asynchronous reply.
553 void afb_req_unref(struct afb_req req);
556 * Stores 'req' on heap for asynchronous use.
557 * Returns a handler to the stored 'req' or NULL on memory depletion.
558 * The count of reference to 'req' is incremented on success
559 * (see afb_req_addref).
561 struct afb_stored_req *afb_req_store(struct afb_req req);
564 * Retrieves the afb_req stored at 'sreq'.
565 * Returns the stored request.
566 * The count of reference is UNCHANGED, thus, the
567 * function 'afb_req_unref' should be called on the result
568 * after that the asynchronous reply if sent.
570 struct afb_req afb_req_unstore(struct afb_stored_req *sreq);
573 The two following functions are used to associate client with events
578 * Establishes for the client link identified by 'req' a subscription
580 * Returns 0 in case of successful subscription or -1 in case of error.
582 int afb_req_subscribe(struct afb_req req, struct afb_event event);
585 * Revokes the subscription established to the 'event' for the client
586 * link identified by 'req'.
587 * Returns 0 in case of successful subscription or -1 in case of error.
589 int afb_req_unsubscribe(struct afb_req req, struct afb_event event);
592 The following functions must be used to make request in the name of the
593 client (with its permissions).
597 * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
598 * This call is made in the context of the request 'req'.
599 * On completion, the function 'callback' is invoked with the
600 * 'closure' given at call and two other parameters: 'iserror' and 'result'.
601 * 'status' is 0 on success or negative when on an error reply.
602 * 'result' is the json object of the reply, you must not call json_object_put
605 * For convenience, the function calls 'json_object_put' for 'args'.
606 * Thus, in the case where 'args' should remain available after
607 * the function returns, the function 'json_object_get' shall be used.
610 * - 'afb_req_subcall_req' that is convenient to keep request alive automatically.
611 * - 'afb_req_subcall_sync' the synchronous version
613 void afb_req_subcall(
617 struct json_object *args,
618 void (*callback)(void *closure, int status, struct json_object *result),
622 * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
623 * This call is made in the context of the request 'req'.
624 * On completion, the function 'callback' is invoked with the
625 * original request 'req', the 'closure' given at call and two
626 * other parameters: 'iserror' and 'result'.
627 * 'status' is 0 on success or negative when on an error reply.
628 * 'result' is the json object of the reply, you must not call json_object_put
631 * For convenience, the function calls 'json_object_put' for 'args'.
632 * Thus, in the case where 'args' should remain available after
633 * the function returns, the function 'json_object_get' shall be used.
636 * - 'afb_req_subcall' that doesn't keep request alive automatically.
637 * - 'afb_req_subcall_sync' the synchronous version
639 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)
641 req.itf->subcall_req(req.closure, api, verb, args, callback, closure);
645 * Makes a call to the method of name 'api' / 'verb' with the object 'args'.
646 * This call is made in the context of the request 'req'.
647 * This call is synchronous, it waits until completion of the request.
648 * It returns 0 on success or a negative value on error answer.
649 * The object pointed by 'result' is filled and must be released by the caller
650 * after its use by calling 'json_object_put'.
652 * For convenience, the function calls 'json_object_put' for 'args'.
653 * Thus, in the case where 'args' should remain available after
654 * the function returns, the function 'json_object_get' shall be used.
657 * - 'afb_req_subcall_req' that is convenient to keep request alive automatically.
658 * - 'afb_req_subcall' that doesn't keep request alive automatically.
660 int afb_req_subcall_sync(
664 struct json_object *args,
665 struct json_object **result);
668 The following function is used by logging macros and should normally
670 Instead, you should use the macros:
673 - **AFB_REQ_WARNING**
680 * Send associated to 'req' a message described by 'fmt' and following parameters
681 * to the journal for the verbosity 'level'.
683 * 'file', 'line' and 'func' are indicators of position of the code in source files
684 * (see macros __FILE__, __LINE__ and __func__).
686 * 'level' is defined by syslog standard:
687 * EMERGENCY 0 System is unusable
688 * ALERT 1 Action must be taken immediately
689 * CRITICAL 2 Critical conditions
690 * ERROR 3 Error conditions
691 * WARNING 4 Warning conditions
692 * NOTICE 5 Normal but significant condition
693 * INFO 6 Informational
694 * DEBUG 7 Debug-level messages
696 void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...);
699 The functions below allow a binding involved in the platform security
700 to explicitly check a permission of a client or to get the calling
701 application identity.
705 * Check whether the 'permission' is granted or not to the client
706 * identified by 'req'.
708 * Returns 1 if the permission is granted or 0 otherwise.
710 int afb_req_has_permission(struct afb_req req, const char *permission);
713 * Get the application identifier of the client application for the
716 * Returns the application identifier or NULL when the application
717 * can not be identified.
719 * The returned value if not NULL must be freed by the caller
721 char *afb_req_get_application_id(struct afb_req req);
724 * Get the user identifier (UID) of the client application for the
727 * Returns -1 when the application can not be identified.
729 int afb_req_get_uid(struct afb_req req);
734 The following macros must be used for logging:
744 The following macros can be used for logging in the context
745 of a request **req** of type **afb_req**:
748 AFB_REQ_ERROR(req,fmt,...)
749 AFB_REQ_WARNING(req,fmt,...)
750 AFB_REQ_NOTICE(req,fmt,...)
751 AFB_REQ_INFO(req,fmt,...)
752 AFB_REQ_DEBUG(req,fmt,...)
755 By default, the logging macros add file, line and function