afb-xreq: hide internal addref/unref to xreqs
[src/app-framework-binder.git] / src / afb-xreq.c
index d021c52..13deeb0 100644 (file)
@@ -16,7 +16,6 @@
  */
 
 #define _GNU_SOURCE
-#define AFB_BINDING_PRAGMA_NO_VERBOSE_MACRO
 
 #include <stdlib.h>
 #include <stdio.h>
 
 /******************************************************************************/
 
-static inline void xreq_addref(struct afb_xreq *xreq)
+static void xreq_finalize(struct afb_xreq *xreq)
+{
+       if (!xreq->replied)
+               afb_xreq_fail(xreq, "error", "no reply");
+       if (xreq->hookflags)
+               afb_hook_xreq_end(xreq);
+       if (xreq->caller)
+               afb_xreq_unhooked_unref(xreq->caller);
+       xreq->queryitf->unref(xreq);
+}
+
+inline void afb_xreq_unhooked_addref(struct afb_xreq *xreq)
 {
        __atomic_add_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED);
 }
 
-static inline void xreq_unref(struct afb_xreq *xreq)
+inline void afb_xreq_unhooked_unref(struct afb_xreq *xreq)
 {
-       if (!__atomic_sub_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED)) {
-               if (!xreq->replied)
-                       afb_xreq_fail(xreq, "error", "no reply");
-               if (xreq->hookflags)
-                       afb_hook_xreq_end(xreq);
-               xreq->queryitf->unref(xreq);
-       }
+       if (!__atomic_sub_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED))
+               xreq_finalize(xreq);
 }
 
 /******************************************************************************/
 
-extern const struct afb_req_itf xreq_itf;
-extern const struct afb_req_itf xreq_hooked_itf;
-
 static inline struct afb_req to_req(struct afb_xreq *xreq)
 {
-       return (struct afb_req){ .itf = xreq->hookflags ? &xreq_hooked_itf : &xreq_itf, .closure = xreq };
+       return (struct afb_req){ .itf = xreq->itf, .closure = xreq };
 }
 
 /******************************************************************************/
@@ -72,9 +74,9 @@ static inline struct afb_req to_req(struct afb_xreq *xreq)
 struct subcall
 {
        struct afb_xreq xreq;
-       struct afb_xreq *caller;
-       void (*callback)(void*, int, struct json_object*);
-       void *closure;
+
+       void (*completion)(struct subcall*, int, struct json_object*);
+
        union {
                struct {
                        struct jobloop *jobloop;
@@ -87,48 +89,47 @@ struct subcall
                                void (*callback2)(void*, int, struct json_object*, struct afb_req);
                        };
                        void *closure;
-               } hooked;
+               };
        };
 };
 
-static int subcall_subscribe(struct afb_xreq *xreq, struct afb_event event)
+static int subcall_subscribe_cb(struct afb_xreq *xreq, struct afb_event event)
 {
        struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
 
-       return afb_xreq_subscribe(subcall->caller, event);
+       return afb_xreq_subscribe(subcall->xreq.caller, event);
 }
 
-static int subcall_unsubscribe(struct afb_xreq *xreq, struct afb_event event)
+static int subcall_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event event)
 {
        struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
 
-       return afb_xreq_unsubscribe(subcall->caller, event);
+       return afb_xreq_unsubscribe(subcall->xreq.caller, event);
 }
 
-static void subcall_reply(struct afb_xreq *xreq, int status, struct json_object *obj)
+static void subcall_reply_cb(struct afb_xreq *xreq, int status, struct json_object *result)
 {
        struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
 
-       if (subcall->callback)
-               subcall->callback(subcall->closure, status, obj);
-       json_object_put(obj);
+       subcall->completion(subcall, status, result);
+       json_object_put(result);
+       afb_xreq_unhooked_unref(&subcall->xreq);
 }
 
-static void subcall_destroy(struct afb_xreq *xreq)
+static void subcall_destroy_cb(struct afb_xreq *xreq)
 {
        struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
 
        json_object_put(subcall->xreq.json);
        afb_cred_unref(subcall->xreq.cred);
-       xreq_unref(subcall->caller);
        free(subcall);
 }
 
 const struct afb_xreq_query_itf afb_xreq_subcall_itf = {
-       .reply = subcall_reply,
-       .unref = subcall_destroy,
-       .subscribe = subcall_subscribe,
-       .unsubscribe = subcall_unsubscribe
+       .reply = subcall_reply_cb,
+       .unref = subcall_destroy_cb,
+       .subscribe = subcall_subscribe_cb,
+       .unsubscribe = subcall_unsubscribe_cb
 };
 
 static struct subcall *subcall_alloc(
@@ -161,21 +162,87 @@ static struct subcall *subcall_alloc(
                subcall->xreq.json = args;
                subcall->xreq.api = api;
                subcall->xreq.verb = verb;
-               subcall->caller = caller;
-               xreq_addref(caller);
+               subcall->xreq.caller = caller;
+               afb_xreq_unhooked_addref(caller);
        }
        return subcall;
 }
 
-static void subcall_process(struct subcall *subcall)
+
+static void subcall_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       subcall->callback(subcall->closure, status, result);
+}
+
+static void subcall_req_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       subcall->callback2(subcall->closure, status, result, to_req(subcall->xreq.caller));
+}
+
+static void subcall_hooked_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       afb_hook_xreq_subcall_result(subcall->xreq.caller, status, result);
+       subcall_on_reply(subcall, status, result);
+}
+
+static void subcall_req_hooked_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       afb_hook_xreq_subcall_req_result(subcall->xreq.caller, status, result);
+       subcall_req_on_reply(subcall, status, result);
+}
+
+static void subcall_reply_direct_cb(void *closure, int status, struct json_object *result)
+{
+       struct afb_xreq *xreq = closure;
+
+       if (xreq->replied) {
+               ERROR("subcall replied more than one time!!");
+               json_object_put(result);
+       } else {
+               xreq->replied = 1;
+               subcall_reply_cb(xreq, status, result);
+       }
+}
+
+static void subcall_process(struct subcall *subcall, void (*completion)(struct subcall*, int, struct json_object*))
+{
+       subcall->completion = completion;
+       if (subcall->xreq.caller->queryitf->subcall) {
+               subcall->xreq.caller->queryitf->subcall(
+                       subcall->xreq.caller, subcall->xreq.api, subcall->xreq.verb,
+                       subcall->xreq.json, subcall_reply_direct_cb, &subcall->xreq);
+       } else {
+               afb_xreq_unhooked_addref(&subcall->xreq);
+               afb_xreq_process(&subcall->xreq, subcall->xreq.caller->apiset);
+       }
+}
+
+static void subcall(struct subcall *subcall, void (*callback)(void*, int, struct json_object*), void *cb_closure)
+{
+       subcall->callback = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_on_reply);
+}
+
+static void subcall_req(struct subcall *subcall, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
+{
+       subcall->callback2 = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_req_on_reply);
+}
+
+static void subcall_hooked(struct subcall *subcall, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 {
-       if (subcall->caller->queryitf->subcall) {
-               subcall->caller->queryitf->subcall(
-                       subcall->caller, subcall->xreq.api, subcall->xreq.verb,
-                       subcall->xreq.json, subcall->callback, subcall->closure);
-               xreq_unref(&subcall->xreq);
-       } else
-               afb_xreq_process(&subcall->xreq, subcall->caller->apiset);
+       subcall->callback = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_hooked_on_reply);
+}
+
+static void subcall_req_hooked(struct subcall *subcall, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
+{
+       subcall->callback2 = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_req_hooked_on_reply);
 }
 
 static void subcall_sync_leave(struct subcall *subcall)
@@ -185,12 +252,10 @@ static void subcall_sync_leave(struct subcall *subcall)
                jobs_leave(jobloop);
 }
 
-static void subcall_sync_reply(void *closure, int status, struct json_object *obj)
+static void subcall_sync_reply(struct subcall *subcall, int status, struct json_object *result)
 {
-       struct subcall *subcall = closure;
-
        subcall->status = status;
-       subcall->result = json_object_get(obj);
+       subcall->result = json_object_get(result);
        subcall_sync_leave(subcall);
 }
 
@@ -200,13 +265,30 @@ static void subcall_sync_enter(int signum, void *closure, struct jobloop *jobloo
 
        if (!signum) {
                subcall->jobloop = jobloop;
-               subcall_process(subcall);
+               subcall->result = NULL;
+               subcall->status = 0;
+               subcall_process(subcall, subcall_sync_reply);
        } else {
                subcall->status = -1;
                subcall_sync_leave(subcall);
        }
 }
 
+static int subcallsync(struct subcall *subcall, struct json_object **result)
+{
+       int rc;
+
+       afb_xreq_unhooked_addref(&subcall->xreq);
+       rc = jobs_enter(NULL, 0, subcall_sync_enter, subcall);
+       *result = subcall->result;
+       if (rc < 0 || subcall->status < 0) {
+               *result = *result ?: afb_msg_json_internal_error();
+               rc = -1;
+       }
+       afb_xreq_unhooked_unref(&subcall->xreq);
+       return rc;
+}
+
 /******************************************************************************/
 
 static void vinfo(void *first, void *second, const char *fmt, va_list args, void (*fun)(void*,void*,const char*))
@@ -306,13 +388,13 @@ static void xreq_context_set_cb(void *closure, void *value, void (*free_value)(v
 static void xreq_addref_cb(void *closure)
 {
        struct afb_xreq *xreq = closure;
-       xreq_addref(xreq);
+       afb_xreq_unhooked_addref(xreq);
 }
 
 static void xreq_unref_cb(void *closure)
 {
        struct afb_xreq *xreq = closure;
-       xreq_unref(xreq);
+       afb_xreq_unhooked_unref(xreq);
 }
 
 static void xreq_session_close_cb(void *closure)
@@ -364,42 +446,30 @@ int afb_xreq_unsubscribe(struct afb_xreq *xreq, struct afb_event event)
 static void xreq_subcall_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 {
        struct afb_xreq *xreq = closure;
-       struct subcall *subcall;
+       struct subcall *sc;
 
-       subcall = subcall_alloc(xreq, api, verb, args);
-       if (subcall == NULL) {
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
                if (callback)
                        callback(cb_closure, 1, afb_msg_json_internal_error());
                json_object_put(args);
        } else {
-               subcall->callback = callback;
-               subcall->closure = cb_closure;
-               subcall_process(subcall);
+               subcall(sc, callback, cb_closure);
        }
 }
 
-static void xreq_subcall_req_reply_cb(void *closure, int status, struct json_object *result)
-{
-       struct subcall *subcall = closure;
-       subcall->hooked.callback2(subcall->hooked.closure, status, result, to_req(subcall->caller));
-}
-
 static void xreq_subcall_req_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
 {
        struct afb_xreq *xreq = closure;
-       struct subcall *subcall;
+       struct subcall *sc;
 
-       subcall = subcall_alloc(xreq, api, verb, args);
-       if (subcall == NULL) {
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
                if (callback)
                        callback(cb_closure, 1, afb_msg_json_internal_error(), to_req(xreq));
                json_object_put(args);
        } else {
-               subcall->callback = xreq_subcall_req_reply_cb;
-               subcall->closure = subcall;
-               subcall->hooked.callback2 = callback;
-               subcall->hooked.closure = cb_closure;
-               subcall_process(subcall);
+               subcall_req(sc, callback, cb_closure);
        }
 }
 
@@ -407,27 +477,17 @@ static void xreq_subcall_req_cb(void *closure, const char *api, const char *verb
 static int xreq_subcallsync_cb(void *closure, const char *api, const char *verb, struct json_object *args, struct json_object **result)
 {
        int rc;
-       struct subcall *subcall;
+       struct subcall *sc;
        struct afb_xreq *xreq = closure;
        struct json_object *resu;
 
-       subcall = subcall_alloc(xreq, api, verb, args);
-       if (!subcall) {
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (!sc) {
                rc = -1;
                resu = afb_msg_json_internal_error();
                json_object_put(args);
        } else {
-               subcall->callback = subcall_sync_reply;
-               subcall->closure = subcall;
-               subcall->jobloop = NULL;
-               subcall->result = NULL;
-               subcall->status = 0;
-               rc = jobs_enter(NULL, 0, subcall_sync_enter, subcall);
-               resu = subcall->result;
-               if (rc < 0 || subcall->status < 0) {
-                       resu = resu ?: afb_msg_json_internal_error();
-                       rc = -1;
-               }
+               rc = subcallsync(sc, &resu);
        }
        if (result)
                *result = resu;
@@ -438,8 +498,15 @@ static int xreq_subcallsync_cb(void *closure, const char *api, const char *verb,
 
 static void xreq_vverbose_cb(void*closure, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
 {
-       /* TODO: improves the implementation. example: on condition make a list of log messages that will be returned */
-       vverbose(level, file, line, func, fmt, args);
+       char *p;
+       struct afb_xreq *xreq = closure;
+
+       if (!fmt || vasprintf(&p, fmt, args) < 0)
+               vverbose(level, file, line, func, fmt, args);
+       else {
+               verbose(level, file, line, func, "[REQ/API %s] %s", xreq->api, p);
+               free(p);
+       }
 }
 
 static struct afb_stored_req *xreq_store_cb(void *closure)
@@ -448,6 +515,18 @@ static struct afb_stored_req *xreq_store_cb(void *closure)
        return closure;
 }
 
+static int xreq_has_permission_cb(void*closure, const char *permission)
+{
+       struct afb_xreq *xreq = closure;
+       return afb_auth_has_permission(xreq, permission);
+}
+
+static char *xreq_get_application_id_cb(void*closure)
+{
+       struct afb_xreq *xreq = closure;
+       return xreq->cred && xreq->cred->id ? strdup(xreq->cred->id) : NULL;
+}
+
 /******************************************************************************/
 
 static struct json_object *xreq_hooked_json_cb(void *closure)
@@ -544,59 +623,35 @@ static int xreq_hooked_unsubscribe_cb(void *closure, struct afb_event event)
        return afb_hook_xreq_unsubscribe(xreq, event, r);
 }
 
-static void xreq_hooked_subcall_reply_cb(void *closure, int status, struct json_object *result)
-{
-       struct subcall *subcall = closure;
-
-       afb_hook_xreq_subcall_result(subcall->caller, status, result);
-       subcall->hooked.callback(subcall->hooked.closure, status, result);
-}
-
 static void xreq_hooked_subcall_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 {
        struct afb_xreq *xreq = closure;
-       struct subcall *subcall;
+       struct subcall *sc;
 
        afb_hook_xreq_subcall(xreq, api, verb, args);
-       subcall = subcall_alloc(xreq, api, verb, args);
-       if (subcall == NULL) {
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
                if (callback)
                        callback(cb_closure, 1, afb_msg_json_internal_error());
                json_object_put(args);
        } else {
-               subcall->callback = xreq_hooked_subcall_reply_cb;
-               subcall->closure = subcall;
-               subcall->hooked.callback = callback;
-               subcall->hooked.closure = cb_closure;
-               subcall_process(subcall);
+               subcall_hooked(sc, callback, cb_closure);
        }
 }
 
-static void xreq_hooked_subcall_req_reply_cb(void *closure, int status, struct json_object *result)
-{
-       struct subcall *subcall = closure;
-
-       afb_hook_xreq_subcall_req_result(subcall->caller, status, result);
-       subcall->hooked.callback2(subcall->hooked.closure, status, result, to_req(subcall->caller));
-}
-
 static void xreq_hooked_subcall_req_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
 {
        struct afb_xreq *xreq = closure;
-       struct subcall *subcall;
+       struct subcall *sc;
 
        afb_hook_xreq_subcall_req(xreq, api, verb, args);
-       subcall = subcall_alloc(xreq, api, verb, args);
-       if (subcall == NULL) {
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
                if (callback)
                        callback(cb_closure, 1, afb_msg_json_internal_error(), to_req(xreq));
                json_object_put(args);
        } else {
-               subcall->callback = xreq_hooked_subcall_req_reply_cb;
-               subcall->closure = subcall;
-               subcall->hooked.callback2 = callback;
-               subcall->hooked.closure = cb_closure;
-               subcall_process(subcall);
+               subcall_req_hooked(sc, callback, cb_closure);
        }
 }
 
@@ -627,6 +682,20 @@ static struct afb_stored_req *xreq_hooked_store_cb(void *closure)
        return r;
 }
 
+static int xreq_hooked_has_permission_cb(void*closure, const char *permission)
+{
+       struct afb_xreq *xreq = closure;
+       int r = xreq_has_permission_cb(closure, permission);
+       return afb_hook_xreq_has_permission(xreq, permission, r);
+}
+
+static char *xreq_hooked_get_application_id_cb(void*closure)
+{
+       struct afb_xreq *xreq = closure;
+       char *r = xreq_get_application_id_cb(closure);
+       return afb_hook_xreq_get_application_id(xreq, r);
+}
+
 /******************************************************************************/
 
 const struct afb_req_itf xreq_itf = {
@@ -648,7 +717,9 @@ const struct afb_req_itf xreq_itf = {
        .subcallsync = xreq_subcallsync_cb,
        .vverbose = xreq_vverbose_cb,
        .store = xreq_store_cb,
-       .subcall_req = xreq_subcall_req_cb
+       .subcall_req = xreq_subcall_req_cb,
+       .has_permission = xreq_has_permission_cb,
+       .get_application_id = xreq_get_application_id_cb
 };
 
 const struct afb_req_itf xreq_hooked_itf = {
@@ -670,7 +741,9 @@ const struct afb_req_itf xreq_hooked_itf = {
        .subcallsync = xreq_hooked_subcallsync_cb,
        .vverbose = xreq_hooked_vverbose_cb,
        .store = xreq_hooked_store_cb,
-       .subcall_req = xreq_hooked_subcall_req_cb
+       .subcall_req = xreq_hooked_subcall_req_cb,
+       .has_permission = xreq_hooked_has_permission_cb,
+       .get_application_id = xreq_hooked_get_application_id_cb
 };
 
 /******************************************************************************/
@@ -695,14 +768,11 @@ void afb_xreq_success(struct afb_xreq *xreq, struct json_object *obj, const char
 
 void afb_xreq_success_f(struct afb_xreq *xreq, struct json_object *obj, const char *info, ...)
 {
-       char *message;
        va_list args;
+
        va_start(args, info);
-       if (info == NULL || vasprintf(&message, info, args) < 0)
-               message = NULL;
+       afb_req_success_v(to_req(xreq), obj, info, args);
        va_end(args);
-       afb_xreq_success(xreq, obj, message);
-       free(message);
 }
 
 void afb_xreq_fail(struct afb_xreq *xreq, const char *status, const char *info)
@@ -712,14 +782,12 @@ void afb_xreq_fail(struct afb_xreq *xreq, const char *status, const char *info)
 
 void afb_xreq_fail_f(struct afb_xreq *xreq, const char *status, const char *info, ...)
 {
-       char *message;
        va_list args;
+
        va_start(args, info);
-       if (info == NULL || vasprintf(&message, info, args) < 0)
-               message = NULL;
+       afb_req_fail_v(to_req(xreq), status, info, args);
        va_end(args);
-       afb_xreq_fail(xreq, status, message);
-       free(message);
+
 }
 
 const char *afb_xreq_raw(struct afb_xreq *xreq, size_t *size)
@@ -823,7 +891,7 @@ static int xreq_session_check_apply_v2(struct afb_xreq *xreq, uint32_t sessionfl
                return -1;
        }
 
-       if (auth && !afb_auth_check(auth, xreq)) {
+       if (auth && !afb_auth_check(xreq, auth)) {
                afb_xreq_fail_f(xreq, "denied", "authorisation refused");
                errno = EPERM;
                return -1;
@@ -860,6 +928,7 @@ void afb_xreq_call_verb_v2(struct afb_xreq *xreq, const struct afb_verb_v2 *verb
 void afb_xreq_init(struct afb_xreq *xreq, const struct afb_xreq_query_itf *queryitf)
 {
        memset(xreq, 0, sizeof *xreq);
+       xreq->itf = &xreq_hooked_itf; /* hook by default */
        xreq->refcount = 1;
        xreq->queryitf = queryitf;
 }
@@ -874,55 +943,102 @@ void afb_xreq_fail_unknown_verb(struct afb_xreq *xreq)
        afb_xreq_fail_f(xreq, "unknown-verb", "verb %s unknown within api %s", xreq->verb, xreq->api);
 }
 
-static void process_sync(struct afb_xreq *xreq)
+static void init_hooking(struct afb_xreq *xreq)
 {
-       const struct afb_api *api;
-
-       /* init hooking */
        afb_hook_init_xreq(xreq);
        if (xreq->hookflags)
                afb_hook_xreq_begin(xreq);
-
-       /* search the api */
-       api = (const struct afb_api*)xreq->context.api_key;
-       if (api)
-               api->itf->call(api->closure, xreq);
-       else {
-               api = afb_apiset_lookup_started(xreq->apiset, xreq->api, 1);
-               if (errno == ENOENT)
-                       afb_xreq_fail_f(xreq, "unknown-api", "api %s not found", xreq->api);
-               else
-                       afb_xreq_fail_f(xreq, "bad-api-state", "api %s not started correctly: %m", xreq->api);
-       }
+       else
+               xreq->itf = &xreq_itf; /* unhook the interface */
 }
 
+/**
+ * job callback for asynchronous and secured processing of the request.
+ */
 static void process_async(int signum, void *arg)
 {
        struct afb_xreq *xreq = arg;
+       const struct afb_api *api;
 
        if (signum != 0) {
+               /* emit the error (assumes that hooking is initialised) */
                afb_xreq_fail_f(xreq, "aborted", "signal %s(%d) caught", strsignal(signum), signum);
        } else {
-               process_sync(xreq);
+               /* init hooking */
+               init_hooking(xreq);
+               /* invoke api call method to process the reqiest */
+               api = (const struct afb_api*)xreq->context.api_key;
+               api->itf->call(api->closure, xreq);
        }
-       xreq_unref(xreq);
+       /* release the request */
+       afb_xreq_unhooked_unref(xreq);
 }
 
+/**
+ * Early request failure of the request 'xreq' with, as usual, 'status' and 'info'
+ * The early failure occurs only in function 'afb_xreq_process' where normally,
+ * the hooking is not initialised. So this "early" failure takes care to initialise
+ * the hooking in first.
+ */
+static void early_failure(struct afb_xreq *xreq, const char *status, const char *info, ...)
+{
+       va_list args;
+
+       /* init hooking */
+       init_hooking(xreq);
+
+       /* send error */
+       va_start(args, info);
+       afb_req_fail_v(to_req(xreq), status, info, args);
+       va_end(args);
+}
+
+/**
+ * Enqueue a job for processing the request 'xreq' using the given 'apiset'.
+ * Errors are reported as request failures.
+ */
 void afb_xreq_process(struct afb_xreq *xreq, struct afb_apiset *apiset)
 {
        const struct afb_api *api;
+       struct afb_xreq *caller;
 
+       /* lookup at the api */
        xreq->apiset = apiset;
        api = afb_apiset_lookup_started(apiset, xreq->api, 1);
-       xreq->context.api_key = (void*)api;
+       if (!api) {
+               if (errno == ENOENT)
+                       early_failure(xreq, "unknown-api", "api %s not found (for verb %s)", xreq->api, xreq->verb);
+               else
+                       early_failure(xreq, "bad-api-state", "api %s not started correctly: %m", xreq->api);
+               goto end;
+       }
+       xreq->context.api_key = api;
+
+       /* check self locking */
+       if (!api->noconcurrency)
+               api = NULL;
+       else {
+               caller = xreq->caller;
+               while (caller) {
+                       if (caller->context.api_key == api) {
+                               /* noconcurrency lock detected */
+                               ERROR("self-lock detected in call stack for API %s", xreq->api);
+                               early_failure(xreq, "self-locked", "recursive self lock, API %s", xreq->api);
+                               goto end;
+                       }
+                       caller = caller->caller;
+               }
+       }
 
-       xreq_addref(xreq);
-       if (jobs_queue(api && api->noconcurrency ? (void*)api : NULL, afb_apiset_timeout_get(apiset), process_async, xreq) < 0) {
+       /* queue the request job */
+       afb_xreq_unhooked_addref(xreq);
+       if (jobs_queue(api, afb_apiset_timeout_get(apiset), process_async, xreq) < 0) {
                /* TODO: allows or not to proccess it directly as when no threading? (see above) */
                ERROR("can't process job with threads: %m");
-               afb_xreq_fail_f(xreq, "cancelled", "not able to create a job for the task");
-               xreq_unref(xreq);
+               early_failure(xreq, "cancelled", "not able to create a job for the task");
+               afb_xreq_unhooked_unref(xreq);
        }
-       xreq_unref(xreq);
+end:
+       afb_xreq_unhooked_unref(xreq);
 }