/* * Copyright (C) 2016, 2017 "IoT.bzh" * Author: José Bollo <jose.bollo@iot.bzh> * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #pragma once #include <stdarg.h> #include "afb-event-itf.h" /* avoid inclusion of <json-c/json.h> */ struct json_object; /* * Describes an argument (or parameter) of a request */ struct afb_arg { const char *name; /* name of the argument or NULL if invalid */ const char *value; /* string representation of the value of the argument */ /* original filename of the argument if path != NULL */ const char *path; /* if not NULL, path of the received file for the argument */ /* when the request is finalized this file is removed */ }; /* * Interface for handling requests. * It records the functions to be called for the request. * Don't use this structure directly. * Use the helper functions documented below. */ struct afb_req_itf { /* CAUTION: respect the order, add at the end */ struct json_object *(*json)(void *closure); struct afb_arg (*get)(void *closure, const char *name); void (*success)(void *closure, struct json_object *obj, const char *info); void (*fail)(void *closure, const char *status, const char *info); void (*vsuccess)(void *closure, struct json_object *obj, const char *fmt, va_list args); void (*vfail)(void *closure, const char *status, const char *fmt, va_list args); void *(*context_get)(void *closure); void (*context_set)(void *closure, void *value, void (*free_value)(void*)); void (*addref)(void *closure); void (*unref)(void *closure); void (*session_close)(void *closure); int (*session_set_LOA)(void *closure, unsigned level); int (*subscribe)(void *closure, struct afb_event event); int (*unsubscribe)(void *closure, struct afb_event event); void (*subcall)(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure); int (*subcallsync)(void *closure, const char *api, const char *verb, struct json_object *args, struct json_object **result); void (*vverbose)(void*closure, int level, const char *file, int line, const char * func, const char *fmt, va_list args); }; /* * Describes the request by bindings from afb-daemon */ struct afb_req { const struct afb_req_itf *itf; /* the interface to use */ void *closure; /* the closure argument for functions of 'itf' */ }; /* * Checks wether the request 'req' is valid or not. * * Returns 0 if not valid or 1 if valid. */ static inline int afb_req_is_valid(struct afb_req req) { return req.itf != NULL; } /* * Gets from the request 'req' the argument of 'name'. * Returns a PLAIN structure of type 'struct afb_arg'. * When the argument of 'name' is not found, all fields of result are set to NULL. * When the argument of 'name' is found, the fields are filled, * in particular, the field 'result.name' is set to 'name'. * * There is a special name value: the empty string. * The argument of name "" is defined only if the request was made using * an HTTP POST of Content-Type "application/json". In that case, the * argument of name "" receives the value of the body of the HTTP request. */ static inline struct afb_arg afb_req_get(struct afb_req req, const char *name) { return req.itf->get(req.closure, name); } /* * Gets from the request 'req' the string value of the argument of 'name'. * Returns NULL if when there is no argument of 'name'. * Returns the value of the argument of 'name' otherwise. * * Shortcut for: afb_req_get(req, name).value */ static inline const char *afb_req_value(struct afb_req req, const char *name) { return afb_req_get(req, name).value; } /* * Gets from the request 'req' the path for file attached to the argument of 'name'. * Returns NULL if when there is no argument of 'name' or when there is no file. * Returns the path of the argument of 'name' otherwise. * * Shortcut for: afb_req_get(req, name).path */ static inline const char *afb_req_path(struct afb_req req, const char *name) { return afb_req_get(req, name).path; } /* * Gets from the request 'req' the json object hashing the arguments. * The returned object must not be released using 'json_object_put'. */ static inline struct json_object *afb_req_json(struct afb_req req) { return req.itf->json(req.closure); } /* * Sends a reply of kind success to the request 'req'. * The status of the reply is automatically set to "success". * Its send the object 'obj' (can be NULL) with an * informationnal comment 'info (can also be NULL). * * For convenience, the function calls 'json_object_put' for 'obj'. * Thus, in the case where 'obj' should remain available after * the function returns, the function 'json_object_get' shall be used. */ static inline void afb_req_success(struct afb_req req, struct json_object *obj, const char *info) { req.itf->success(req.closure, obj, info); } /* * Same as 'afb_req_success' but the 'info' is a formatting * string followed by arguments. * * For convenience, the function calls 'json_object_put' for 'obj'. * Thus, in the case where 'obj' should remain available after * the function returns, the function 'json_object_get' shall be used. */ static inline void afb_req_success_f(struct afb_req req, struct json_object *obj, const char *info, ...) __attribute__((format(printf, 3, 4))); static inline void afb_req_success_f(struct afb_req req, struct json_object *obj, const char *info, ...) { va_list args; va_start(args, info); req.itf->vsuccess(req.closure, obj, info, args); va_end(args); } /* * Same as 'afb_req_success_f' but the arguments to the format 'info' * are given as a variable argument list instance. * * For convenience, the function calls 'json_object_put' for 'obj'. * Thus, in the case where 'obj' should remain available after * the function returns, the function 'json_object_get' shall be used. */ static inline void afb_req_success_v(struct afb_req req, struct json_object *obj, const char *info, va_list args) { req.itf->vsuccess(req.closure, obj, info, args); } /* * Sends a reply of kind failure to the request 'req'. * The status of the reply is set to 'status' and an * informationnal comment 'info' (can also be NULL) can be added. * * Note that calling afb_req_fail("success", info) is equivalent * to call afb_req_success(NULL, info). Thus even if possible it * is strongly recommanded to NEVER use "success" for status. */ static inline void afb_req_fail(struct afb_req req, const char *status, const char *info) { req.itf->fail(req.closure, status, info); } /* * Same as 'afb_req_fail' but the 'info' is a formatting * string followed by arguments. */ static inline void afb_req_fail_f(struct afb_req req, const char *status, const char *info, ...) __attribute__((format(printf, 3, 4))); static inline void afb_req_fail_f(struct afb_req req, const char *status, const char *info, ...) { va_list args; va_start(args, info); req.itf->vfail(req.closure, status, info, args); va_end(args); } /* * Same as 'afb_req_fail_f' but the arguments to the format 'info' * are given as a variable argument list instance. */ static inline void afb_req_fail_v(struct afb_req req, const char *status, const char *info, va_list args) { req.itf->vfail(req.closure, status, info, args); } /* * Gets the pointer stored by the binding for the session of 'req'. * When the binding has not yet recorded a pointer, NULL is returned. */ static inline void *afb_req_context_get(struct afb_req req) { return req.itf->context_get(req.closure); } /* * Stores for the binding the pointer 'context' to the session of 'req'. * The function 'free_context' will be called when the session is closed * or if binding stores an other pointer. */ static inline void afb_req_context_set(struct afb_req req, void *context, void (*free_context)(void*)) { req.itf->context_set(req.closure, context, free_context); } /* * Gets the pointer stored by the binding for the session of 'req'. * If the stored pointer is NULL, indicating that no pointer was * already stored, afb_req_context creates a new context by calling * the function 'create_context' and stores it with the freeing function * 'free_context'. */ static inline void *afb_req_context(struct afb_req req, void *(*create_context)(), void (*free_context)(void*)) { void *result = afb_req_context_get(req); if (result == NULL) { result = create_context(); afb_req_context_set(req, result, free_context); } return result; } /* * Frees the pointer stored by the binding for the session of 'req' * and sets it to NULL. * * Shortcut for: afb_req_context_set(req, NULL, NULL) */ static inline void afb_req_context_clear(struct afb_req req) { afb_req_context_set(req, NULL, NULL); } /* * Adds one to the count of references of 'req'. * This function MUST be called by asynchronous implementations * of verbs if no reply was sent before returning. */ static inline void afb_req_addref(struct afb_req req) { req.itf->addref(req.closure); } /* * Substracts one to the count of references of 'req'. * This function MUST be called by asynchronous implementations * of verbs after sending the asynchronous reply. */ static inline void afb_req_unref(struct afb_req req) { req.itf->unref(req.closure); } /* * Closes the session associated with 'req' * and delete all associated contexts. */ static inline void afb_req_session_close(struct afb_req req) { req.itf->session_close(req.closure); } /* * Sets the level of assurance of the session of 'req' * to 'level'. The effect of this function is subject of * security policies. * Returns 1 on success or 0 if failed. */ static inline int afb_req_session_set_LOA(struct afb_req req, unsigned level) { return req.itf->session_set_LOA(req.closure, level); } /* * Stores 'req' on heap for asynchrnous use. * Returns a pointer to the stored 'req' or NULL on memory depletion. * The count of reference to 'req' is incremented on success * (see afb_req_addref). */ static inline struct afb_req *afb_req_store(struct afb_req req) { struct afb_req *result = (struct afb_req*)malloc(sizeof *result); if (result != NULL) { *result = req; afb_req_addref(req); } return result; } /* * Retrieves the afb_req stored at 'req' and frees the memory. * Returns the stored request. * The count of reference is UNCHANGED, thus, normally, the * function 'afb_req_unref' should be called on the result * after that the asynchronous reply if sent. */ static inline struct afb_req afb_req_unstore(struct afb_req *req) { struct afb_req result = *req; free(req); return result; } /* * Establishes for the client link identified by 'req' a subscription * to the 'event'. * Returns 0 in case of successful subscription or -1 in case of error. */ static inline int afb_req_subscribe(struct afb_req req, struct afb_event event) { return req.itf->subscribe(req.closure, event); } /* * Revokes the subscription established to the 'event' for the client * link identified by 'req'. * Returns 0 in case of successful subscription or -1 in case of error. */ static inline int afb_req_unsubscribe(struct afb_req req, struct afb_event event) { return req.itf->unsubscribe(req.closure, event); } /* * Makes a call to the method of name 'api' / 'verb' with the object 'args'. * This call is made in the context of the request 'req'. * On completion, the function 'callback' is invoked with the * 'closure' given at call and two other parameters: 'iserror' and 'result'. * 'iserror' is a boolean that indicates if the reply is an error reply. * 'result' is the json object of the reply, you must not call json_object_put * on the result. * * For convenience, the function calls 'json_object_put' for 'args'. * Thus, in the case where 'args' should remain available after * the function returns, the function 'json_object_get' shall be used. */ static inline void afb_req_subcall(struct afb_req req, const char *api, const char *verb, struct json_object *args, void (*callback)(void *closure, int iserror, struct json_object *result), void *closure) { req.itf->subcall(req.closure, api, verb, args, callback, closure); } /* * Makes a call to the method of name 'api' / 'verb' with the object 'args'. * This call is made in the context of the request 'req'. * This call is synchronous, it waits untill completion of the request. * It returns 0 on an error answer and returns 1 when no error was detected. * The object pointed by 'result' is filled and must be released by the caller * after its use by calling 'json_object_put'. * * For convenience, the function calls 'json_object_put' for 'args'. * Thus, in the case where 'args' should remain available after * the function returns, the function 'json_object_get' shall be used. */ static inline int afb_req_subcall_sync(struct afb_req req, const char *api, const char *verb, struct json_object *args, struct json_object **result) { return req.itf->subcallsync(req.closure, api, verb, args, result); } /* * Send associated to 'req' a message described by 'fmt' and following parameters * to the journal for the verbosity 'level'. * * 'file', 'line' and 'func' are indicators of position of the code in source files * (see macros __FILE__, __LINE__ and __func__). * * 'level' is defined by syslog standard: * EMERGENCY 0 System is unusable * ALERT 1 Action must be taken immediately * CRITICAL 2 Critical conditions * ERROR 3 Error conditions * WARNING 4 Warning conditions * NOTICE 5 Normal but significant condition * INFO 6 Informational * DEBUG 7 Debug-level messages */ static inline void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...) __attribute__((format(printf, 6, 7))); static inline void afb_req_verbose(struct afb_req req, int level, const char *file, int line, const char * func, const char *fmt, ...) { va_list args; va_start(args, fmt); req.itf->vverbose(req.closure, level, file, line, func, fmt, args); va_end(args); } /* macro for setting file, line and function automatically */ # if !defined(AFB_BINDING_PRAGMA_NO_VERBOSE_DETAILS) #define AFB_REQ_VERBOSE(req,level,...) afb_req_verbose(req,level,__FILE__,__LINE__,__func__,__VA_ARGS__) #else #define AFB_REQ_VERBOSE(req,level,...) afb_req_verbose(req,level,NULL,0,NULL,__VA_ARGS__) #endif