Add hooking for events
[src/app-framework-binder.git] / src / afb-hook.c
index 2e0255d..aa66b5d 100644 (file)
@@ -23,6 +23,7 @@
 #include <string.h>
 #include <pthread.h>
 #include <unistd.h>
+#include <fnmatch.h>
 
 #include <json-c/json.h>
 
 #include "afb-context.h"
 #include "afb-hook.h"
 #include "afb-session.h"
+#include "afb-cred.h"
 #include "afb-xreq.h"
 #include "afb-ditf.h"
+#include "afb-svc.h"
+#include "afb-evt.h"
 #include "verbose.h"
 
 /**
@@ -62,6 +66,18 @@ struct afb_hook_ditf {
        void *closure; /**< closure for callbacks */
 };
 
+/**
+ * Definition of a hook for svc
+ */
+struct afb_hook_svc {
+       struct afb_hook_svc *next; /**< next hook */
+       unsigned refcount; /**< reference count */
+       char *api; /**< api hooked or NULL for any */
+       unsigned flags; /**< hook flags */
+       struct afb_hook_svc_itf *itf; /**< interface of hook */
+       void *closure; /**< closure for callbacks */
+};
+
 /* synchronisation across threads */
 static pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
 
@@ -71,6 +87,9 @@ static struct afb_hook_xreq *list_of_xreq_hooks = NULL;
 /* list of hooks for ditf */
 static struct afb_hook_ditf *list_of_ditf_hooks = NULL;
 
+/* list of hooks for svc */
+static struct afb_hook_svc *list_of_svc_hooks = NULL;
+
 /******************************************************************************
  * section: default callbacks for tracing requests
  *****************************************************************************/
@@ -95,7 +114,17 @@ static void _hook_xreq_(const struct afb_xreq *xreq, const char *format, ...)
 
 static void hook_xreq_begin_default_cb(void * closure, const struct afb_xreq *xreq)
 {
-       _hook_xreq_(xreq, "BEGIN");
+       if (!xreq->cred)
+               _hook_xreq_(xreq, "BEGIN");
+       else
+               _hook_xreq_(xreq, "BEGIN uid=%d=%s gid=%d pid=%d label=%s id=%s",
+                       (int)xreq->cred->uid,
+                       xreq->cred->user,
+                       (int)xreq->cred->gid,
+                       (int)xreq->cred->pid,
+                       xreq->cred->label?:"(null)",
+                       xreq->cred->id?:"(null)"
+               );
 }
 
 static void hook_xreq_end_default_cb(void * closure, const struct afb_xreq *xreq)
@@ -123,16 +152,6 @@ static void hook_xreq_fail_default_cb(void * closure, const struct afb_xreq *xre
        _hook_xreq_(xreq, "fail(%s, %s)", status, info);
 }
 
-static void hook_xreq_raw_default_cb(void * closure, const struct afb_xreq *xreq, const char *buffer, size_t size)
-{
-       _hook_xreq_(xreq, "raw() -> %.*s", (int)size, buffer);
-}
-
-static void hook_xreq_send_default_cb(void * closure, const struct afb_xreq *xreq, const char *buffer, size_t size)
-{
-       _hook_xreq_(xreq, "send(%.*s)", (int)size, buffer);
-}
-
 static void hook_xreq_context_get_default_cb(void * closure, const struct afb_xreq *xreq, void *value)
 {
        _hook_xreq_(xreq, "context_get() -> %p", value);
@@ -165,12 +184,12 @@ static void hook_xreq_session_set_LOA_default_cb(void * closure, const struct af
 
 static void hook_xreq_subscribe_default_cb(void * closure, const struct afb_xreq *xreq, struct afb_event event, int result)
 {
-       _hook_xreq_(xreq, "subscribe(%s:%p) -> %d", afb_event_name(event), event.closure, result);
+       _hook_xreq_(xreq, "subscribe(%s:%d) -> %d", afb_evt_event_name(event), afb_evt_event_id(event), result);
 }
 
 static void hook_xreq_unsubscribe_default_cb(void * closure, const struct afb_xreq *xreq, struct afb_event event, int result)
 {
-       _hook_xreq_(xreq, "unsubscribe(%s:%p) -> %d", afb_event_name(event), event.closure, result);
+       _hook_xreq_(xreq, "unsubscribe(%s:%d) -> %d", afb_evt_event_name(event), afb_evt_event_id(event), result);
 }
 
 static void hook_xreq_subcall_default_cb(void * closure, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args)
@@ -193,6 +212,24 @@ static void hook_xreq_subcallsync_result_default_cb(void * closure, const struct
        _hook_xreq_(xreq, "    ...subcallsync... -> %d: %s", status, json_object_to_json_string(result));
 }
 
+static void hook_xreq_vverbose_default_cb(void * closure, const struct afb_xreq *xreq, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
+{
+       int len;
+       char *msg;
+       va_list ap;
+
+       va_copy(ap, args);
+       len = vasprintf(&msg, fmt, ap);
+       va_end(ap);
+
+       if (len < 0)
+               _hook_xreq_(xreq, "vverbose(%d, %s, %d, %s) -> %s ? ? ?", level, file, line, func, fmt);
+       else {
+               _hook_xreq_(xreq, "vverbose(%d, %s, %d, %s) -> %s", level, file, line, func, msg);
+               free(msg);
+       }
+}
+
 static struct afb_hook_xreq_itf hook_xreq_default_itf = {
        .hook_xreq_begin = hook_xreq_begin_default_cb,
        .hook_xreq_end = hook_xreq_end_default_cb,
@@ -200,8 +237,6 @@ static struct afb_hook_xreq_itf hook_xreq_default_itf = {
        .hook_xreq_get = hook_xreq_get_default_cb,
        .hook_xreq_success = hook_xreq_success_default_cb,
        .hook_xreq_fail = hook_xreq_fail_default_cb,
-       .hook_xreq_raw = hook_xreq_raw_default_cb,
-       .hook_xreq_send = hook_xreq_send_default_cb,
        .hook_xreq_context_get = hook_xreq_context_get_default_cb,
        .hook_xreq_context_set = hook_xreq_context_set_default_cb,
        .hook_xreq_addref = hook_xreq_addref_default_cb,
@@ -214,6 +249,7 @@ static struct afb_hook_xreq_itf hook_xreq_default_itf = {
        .hook_xreq_subcall_result = hook_xreq_subcall_result_default_cb,
        .hook_xreq_subcallsync = hook_xreq_subcallsync_default_cb,
        .hook_xreq_subcallsync_result = hook_xreq_subcallsync_result_default_cb,
+       .hook_xreq_vverbose = hook_xreq_vverbose_default_cb
 };
 
 /******************************************************************************
@@ -269,17 +305,6 @@ void afb_hook_xreq_fail(const struct afb_xreq *xreq, const char *status, const c
        _HOOK_XREQ_(fail, xreq, status, info);
 }
 
-const char *afb_hook_xreq_raw(const struct afb_xreq *xreq, const char *buffer, size_t size)
-{
-       _HOOK_XREQ_(raw, xreq, buffer, size);
-       return buffer;
-}
-
-void afb_hook_xreq_send(const struct afb_xreq *xreq, const char *buffer, size_t size)
-{
-       _HOOK_XREQ_(send, xreq, buffer, size);
-}
-
 void *afb_hook_xreq_context_get(const struct afb_xreq *xreq, void *value)
 {
        _HOOK_XREQ_(context_get, xreq, value);
@@ -345,8 +370,13 @@ int afb_hook_xreq_subcallsync_result(const struct afb_xreq *xreq, int status, st
        return status;
 }
 
+void afb_hook_xreq_vverbose(const struct afb_xreq *xreq, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
+{
+       _HOOK_XREQ_(vverbose, xreq, level, file ?: "?", line, func ?: "?", fmt, args);
+}
+
 /******************************************************************************
- * section: 
+ * section: hooking xreqs
  *****************************************************************************/
 
 void afb_hook_init_xreq(struct afb_xreq *xreq)
@@ -525,7 +555,7 @@ static void hook_ditf_vverbose_cb(void*closure, const struct afb_ditf *ditf, int
 
 static void hook_ditf_event_make_cb(void *closure, const struct afb_ditf *ditf, const char *name, struct afb_event result)
 {
-       _hook_ditf_(ditf, "event_make(%s) -> %s:%p", name, afb_event_name(result), result.closure);
+       _hook_ditf_(ditf, "event_make(%s) -> %s:%d", name, afb_evt_event_name(result), afb_evt_event_id(result));
 }
 
 static void hook_ditf_rootdir_get_fd_cb(void *closure, const struct afb_ditf *ditf, int result)
@@ -554,6 +584,10 @@ static void hook_ditf_rootdir_open_locale_cb(void *closure, const struct afb_dit
        }
 }
 
+static void hook_ditf_queue_job(void *closure, const struct afb_ditf *ditf, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout, int result)
+{
+       _hook_ditf_(ditf, "queue_job(%p, %p, %p, %d) -> %d", callback, argument, group, timeout, result);
+}
 
 static struct afb_hook_ditf_itf hook_ditf_default_itf = {
        .hook_ditf_event_broadcast_before = hook_ditf_event_broadcast_before_cb,
@@ -565,10 +599,11 @@ static struct afb_hook_ditf_itf hook_ditf_default_itf = {
        .hook_ditf_event_make = hook_ditf_event_make_cb,
        .hook_ditf_rootdir_get_fd = hook_ditf_rootdir_get_fd_cb,
        .hook_ditf_rootdir_open_locale = hook_ditf_rootdir_open_locale_cb,
+       .hook_ditf_queue_job = hook_ditf_queue_job
 };
 
 /******************************************************************************
- * section: hooks for tracing requests
+ * section: hooks for tracing daemon interface (ditf)
  *****************************************************************************/
 
 #define _HOOK_DITF_(what,...)   \
@@ -637,10 +672,14 @@ int afb_hook_ditf_rootdir_open_locale(const struct afb_ditf *ditf, const char *f
        return result;
 }
 
-
+int afb_hook_ditf_queue_job(const struct afb_ditf *ditf, void (*callback)(int signum, void *arg), void *argument, void *group, int timeout, int result)
+{
+       _HOOK_DITF_(queue_job, ditf, callback, argument, group, timeout, result);
+       return result;
+}
 
 /******************************************************************************
- * section: 
+ * section: hooking ditf
  *****************************************************************************/
 
 int afb_hook_flags_ditf(const char *api)
@@ -725,3 +764,523 @@ void afb_hook_unref_ditf(struct afb_hook_ditf *hook)
        }
 }
 
+/******************************************************************************
+ * section: default callbacks for tracing service interface (svc)
+ *****************************************************************************/
+
+static void _hook_svc_(const struct afb_svc *svc, const char *format, ...)
+{
+       int len;
+       char *buffer;
+       va_list ap;
+
+       va_start(ap, format);
+       len = vasprintf(&buffer, format, ap);
+       va_end(ap);
+
+       if (len < 0)
+               NOTICE("hook svc-%s allocation error for %s", svc->api, format);
+       else {
+               NOTICE("hook svc-%s %s", svc->api, buffer);
+               free(buffer);
+       }
+}
+
+static void hook_svc_start_before_default_cb(void *closure, const struct afb_svc *svc)
+{
+       _hook_svc_(svc, "start.before");
+}
+
+static void hook_svc_start_after_default_cb(void *closure, const struct afb_svc *svc, int status)
+{
+       _hook_svc_(svc, "start.after -> %d", status);
+}
+
+static void hook_svc_on_event_before_default_cb(void *closure, const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
+{
+       _hook_svc_(svc, "on_event.before(%s, %d, %s)", event, eventid, json_object_to_json_string(object));
+}
+
+static void hook_svc_on_event_after_default_cb(void *closure, const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
+{
+       _hook_svc_(svc, "on_event.after(%s, %d, %s)", event, eventid, json_object_to_json_string(object));
+}
+
+static void hook_svc_call_default_cb(void *closure, const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
+{
+       _hook_svc_(svc, "call(%s/%s, %s) ...", api, verb, json_object_to_json_string(args));
+}
+
+static void hook_svc_call_result_default_cb(void *closure, const struct afb_svc *svc, int status, struct json_object *result)
+{
+       _hook_svc_(svc, "    ...call... -> %d: %s", status, json_object_to_json_string(result));
+}
+
+static void hook_svc_callsync_default_cb(void *closure, const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
+{
+       _hook_svc_(svc, "callsync(%s/%s, %s) ...", api, verb, json_object_to_json_string(args));
+}
+
+static void hook_svc_callsync_result_default_cb(void *closure, const struct afb_svc *svc, int status, struct json_object *result)
+{
+       _hook_svc_(svc, "    ...callsync... -> %d: %s", status, json_object_to_json_string(result));
+}
+
+static struct afb_hook_svc_itf hook_svc_default_itf = {
+       .hook_svc_start_before = hook_svc_start_before_default_cb,
+       .hook_svc_start_after = hook_svc_start_after_default_cb,
+       .hook_svc_on_event_before = hook_svc_on_event_before_default_cb,
+       .hook_svc_on_event_after = hook_svc_on_event_after_default_cb,
+       .hook_svc_call = hook_svc_call_default_cb,
+       .hook_svc_call_result = hook_svc_call_result_default_cb,
+       .hook_svc_callsync = hook_svc_callsync_default_cb,
+       .hook_svc_callsync_result = hook_svc_callsync_result_default_cb
+};
+
+/******************************************************************************
+ * section: hooks for tracing service interface (svc)
+ *****************************************************************************/
+
+#define _HOOK_SVC_(what,...)   \
+       struct afb_hook_svc *hook; \
+       pthread_rwlock_rdlock(&rwlock); \
+       hook = list_of_svc_hooks; \
+       while (hook) { \
+               if (hook->itf->hook_svc_##what \
+                && (hook->flags & afb_hook_flag_svc_##what) != 0 \
+                && (!hook->api || !strcasecmp(hook->api, svc->api))) { \
+                       hook->itf->hook_svc_##what(hook->closure, __VA_ARGS__); \
+               } \
+               hook = hook->next; \
+       } \
+       pthread_rwlock_unlock(&rwlock);
+
+void afb_hook_svc_start_before(const struct afb_svc *svc)
+{
+       _HOOK_SVC_(start_before, svc);
+}
+
+int afb_hook_svc_start_after(const struct afb_svc *svc, int status)
+{
+       _HOOK_SVC_(start_after, svc, status);
+       return status;
+}
+
+void afb_hook_svc_on_event_before(const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
+{
+       _HOOK_SVC_(on_event_before, svc, event, eventid, object);
+}
+
+void afb_hook_svc_on_event_after(const struct afb_svc *svc, const char *event, int eventid, struct json_object *object)
+{
+       _HOOK_SVC_(on_event_after, svc, event, eventid, object);
+}
+
+void afb_hook_svc_call(const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
+{
+       _HOOK_SVC_(call, svc, api, verb, args);
+}
+
+void afb_hook_svc_call_result(const struct afb_svc *svc, int status, struct json_object *result)
+{
+       _HOOK_SVC_(call_result, svc, status, result);
+}
+
+void afb_hook_svc_callsync(const struct afb_svc *svc, const char *api, const char *verb, struct json_object *args)
+{
+       _HOOK_SVC_(callsync, svc, api, verb, args);
+}
+
+int afb_hook_svc_callsync_result(const struct afb_svc *svc, int status, struct json_object *result)
+{
+       _HOOK_SVC_(callsync_result, svc, status, result);
+       return status;
+}
+
+/******************************************************************************
+ * section: hooking services (svc)
+ *****************************************************************************/
+
+int afb_hook_flags_svc(const char *api)
+{
+       int flags;
+       struct afb_hook_svc *hook;
+
+       pthread_rwlock_rdlock(&rwlock);
+       flags = 0;
+       hook = list_of_svc_hooks;
+       while (hook) {
+               if (!api || !hook->api || !strcasecmp(hook->api, api))
+                       flags |= hook->flags;
+               hook = hook->next;
+       }
+       pthread_rwlock_unlock(&rwlock);
+       return flags;
+}
+
+struct afb_hook_svc *afb_hook_create_svc(const char *api, int flags, struct afb_hook_svc_itf *itf, void *closure)
+{
+       struct afb_hook_svc *hook;
+
+       /* alloc the result */
+       hook = calloc(1, sizeof *hook);
+       if (hook == NULL)
+               return NULL;
+
+       /* get a copy of the names */
+       hook->api = api ? strdup(api) : NULL;
+       if (api && !hook->api) {
+               free(hook);
+               return NULL;
+       }
+
+       /* initialise the rest */
+       hook->refcount = 1;
+       hook->flags = flags;
+       hook->itf = itf ? itf : &hook_svc_default_itf;
+       hook->closure = closure;
+
+       /* record the hook */
+       pthread_rwlock_wrlock(&rwlock);
+       hook->next = list_of_svc_hooks;
+       list_of_svc_hooks = hook;
+       pthread_rwlock_unlock(&rwlock);
+
+       /* returns it */
+       return hook;
+}
+
+struct afb_hook_svc *afb_hook_addref_svc(struct afb_hook_svc *hook)
+{
+       pthread_rwlock_wrlock(&rwlock);
+       hook->refcount++;
+       pthread_rwlock_unlock(&rwlock);
+       return hook;
+}
+
+void afb_hook_unref_svc(struct afb_hook_svc *hook)
+{
+       struct afb_hook_svc **prv;
+
+       if (hook) {
+               pthread_rwlock_wrlock(&rwlock);
+               if (--hook->refcount)
+                       hook = NULL;
+               else {
+                       /* unlink */
+                       prv = &list_of_svc_hooks;
+                       while (*prv && *prv != hook)
+                               prv = &(*prv)->next;
+                       if(*prv)
+                               *prv = hook->next;
+               }
+               pthread_rwlock_unlock(&rwlock);
+               if (hook) {
+                       /* free */
+                       free(hook->api);
+                       free(hook);
+               }
+       }
+}
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+/*********************************************************
+* section hooking evt (event interface)
+*********************************************************/
+
+/**
+ * Definition of a hook for evt
+ */
+struct afb_hook_evt {
+       struct afb_hook_evt *next; /**< next hook */
+       unsigned refcount; /**< reference count */
+       char *pattern; /**< event pattern name hooked or NULL for any */
+       unsigned flags; /**< hook flags */
+       struct afb_hook_evt_itf *itf; /**< interface of hook */
+       void *closure; /**< closure for callbacks */
+};
+
+/* list of hooks for evt */
+static struct afb_hook_evt *list_of_evt_hooks = NULL;
+
+
+/******************************************************************************
+ * section: default callbacks for tracing service interface (evt)
+ *****************************************************************************/
+
+static void _hook_evt_(const char *evt, int id, const char *format, ...)
+{
+       int len;
+       char *buffer;
+       va_list ap;
+
+       va_start(ap, format);
+       len = vasprintf(&buffer, format, ap);
+       va_end(ap);
+
+       if (len < 0)
+               NOTICE("hook evt-%s:%d allocation error for %s", evt, id, format);
+       else {
+               NOTICE("hook evt-%s:%d %s", evt, id, buffer);
+               free(buffer);
+       }
+}
+
+static void hook_evt_create_default_cb(void *closure, const char *evt, int id)
+{
+       _hook_evt_(evt, id, "create");
+}
+
+static void hook_evt_push_before_default_cb(void *closure, const char *evt, int id, struct json_object *obj)
+{
+       _hook_evt_(evt, id, "push.before(%s)", json_object_to_json_string(obj));
+}
+
+
+static void hook_evt_push_after_default_cb(void *closure, const char *evt, int id, struct json_object *obj, int result)
+{
+       _hook_evt_(evt, id, "push.after(%s) -> %d", json_object_to_json_string(obj), result);
+}
+
+static void hook_evt_broadcast_before_default_cb(void *closure, const char *evt, int id, struct json_object *obj)
+{
+       _hook_evt_(evt, id, "broadcast.before(%s)", json_object_to_json_string(obj));
+}
+
+static void hook_evt_broadcast_after_default_cb(void *closure, const char *evt, int id, struct json_object *obj, int result)
+{
+       _hook_evt_(evt, id, "broadcast.after(%s) -> %d", json_object_to_json_string(obj), result);
+}
+
+static void hook_evt_name_default_cb(void *closure, const char *evt, int id)
+{
+       _hook_evt_(evt, id, "name");
+}
+
+static void hook_evt_drop_default_cb(void *closure, const char *evt, int id)
+{
+       _hook_evt_(evt, id, "drop");
+}
+
+static struct afb_hook_evt_itf hook_evt_default_itf = {
+       .hook_evt_create = hook_evt_create_default_cb,
+       .hook_evt_push_before = hook_evt_push_before_default_cb,
+       .hook_evt_push_after = hook_evt_push_after_default_cb,
+       .hook_evt_broadcast_before = hook_evt_broadcast_before_default_cb,
+       .hook_evt_broadcast_after = hook_evt_broadcast_after_default_cb,
+       .hook_evt_name = hook_evt_name_default_cb,
+       .hook_evt_drop = hook_evt_drop_default_cb
+};
+
+/******************************************************************************
+ * section: hooks for tracing service interface (evt)
+ *****************************************************************************/
+
+#define _HOOK_EVT_(what,...)   \
+       struct afb_hook_evt *hook; \
+       pthread_rwlock_rdlock(&rwlock); \
+       hook = list_of_evt_hooks; \
+       while (hook) { \
+               if (hook->itf->hook_evt_##what \
+                && (hook->flags & afb_hook_flag_evt_##what) != 0 \
+                && (!hook->pattern || !fnmatch(hook->pattern, evt, FNM_CASEFOLD))) { \
+                       hook->itf->hook_evt_##what(hook->closure, __VA_ARGS__); \
+               } \
+               hook = hook->next; \
+       } \
+       pthread_rwlock_unlock(&rwlock);
+
+void afb_hook_evt_create(const char *evt, int id)
+{
+       _HOOK_EVT_(create, evt, id);
+}
+
+void afb_hook_evt_push_before(const char *evt, int id, struct json_object *obj)
+{
+       _HOOK_EVT_(push_before, evt, id, obj);
+}
+
+int afb_hook_evt_push_after(const char *evt, int id, struct json_object *obj, int result)
+{
+       _HOOK_EVT_(push_after, evt, id, obj, result);
+       return result;
+}
+
+void afb_hook_evt_broadcast_before(const char *evt, int id, struct json_object *obj)
+{
+       _HOOK_EVT_(broadcast_before, evt, id, obj);
+}
+
+int afb_hook_evt_broadcast_after(const char *evt, int id, struct json_object *obj, int result)
+{
+       _HOOK_EVT_(broadcast_after, evt, id, obj, result);
+       return result;
+}
+
+void afb_hook_evt_name(const char *evt, int id)
+{
+       _HOOK_EVT_(name, evt, id);
+}
+
+void afb_hook_evt_drop(const char *evt, int id)
+{
+       _HOOK_EVT_(drop, evt, id);
+}
+
+/******************************************************************************
+ * section: hooking services (evt)
+ *****************************************************************************/
+
+int afb_hook_flags_evt(const char *name)
+{
+       int flags;
+       struct afb_hook_evt *hook;
+
+       pthread_rwlock_rdlock(&rwlock);
+       flags = 0;
+       hook = list_of_evt_hooks;
+       while (hook) {
+               if (!name || !hook->pattern || !fnmatch(hook->pattern, name, FNM_CASEFOLD))
+                       flags |= hook->flags;
+               hook = hook->next;
+       }
+       pthread_rwlock_unlock(&rwlock);
+       return flags;
+}
+
+struct afb_hook_evt *afb_hook_create_evt(const char *pattern, int flags, struct afb_hook_evt_itf *itf, void *closure)
+{
+       struct afb_hook_evt *hook;
+
+       /* alloc the result */
+       hook = calloc(1, sizeof *hook);
+       if (hook == NULL)
+               return NULL;
+
+       /* get a copy of the names */
+       hook->pattern = pattern ? strdup(pattern) : NULL;
+       if (pattern && !hook->pattern) {
+               free(hook);
+               return NULL;
+       }
+
+       /* initialise the rest */
+       hook->refcount = 1;
+       hook->flags = flags;
+       hook->itf = itf ? itf : &hook_evt_default_itf;
+       hook->closure = closure;
+
+       /* record the hook */
+       pthread_rwlock_wrlock(&rwlock);
+       hook->next = list_of_evt_hooks;
+       list_of_evt_hooks = hook;
+       pthread_rwlock_unlock(&rwlock);
+
+       /* returns it */
+       return hook;
+}
+
+struct afb_hook_evt *afb_hook_addref_evt(struct afb_hook_evt *hook)
+{
+       pthread_rwlock_wrlock(&rwlock);
+       hook->refcount++;
+       pthread_rwlock_unlock(&rwlock);
+       return hook;
+}
+
+void afb_hook_unref_evt(struct afb_hook_evt *hook)
+{
+       struct afb_hook_evt **prv;
+
+       if (hook) {
+               pthread_rwlock_wrlock(&rwlock);
+               if (--hook->refcount)
+                       hook = NULL;
+               else {
+                       /* unlink */
+                       prv = &list_of_evt_hooks;
+                       while (*prv && *prv != hook)
+                               prv = &(*prv)->next;
+                       if(*prv)
+                               *prv = hook->next;
+               }
+               pthread_rwlock_unlock(&rwlock);
+               if (hook) {
+                       /* free */
+                       free(hook->pattern);
+                       free(hook);
+               }
+       }
+}
+
+#if 0
+#define afb_hook_flag_evt_create                       0x000001
+#define afb_hook_flag_evt_push_before                  0x000002
+#define afb_hook_flag_evt_push_after                   0x000004
+#define afb_hook_flag_evt_broadcast_before             0x000008
+#define afb_hook_flag_evt_broadcast_after              0x000010
+#define afb_hook_flag_evt_drop                         0x000020
+#define afb_hook_flag_evt_name                         0x000040
+
+struct afb_hook_evt_itf {
+       void (*hook_evt_create)(void *closure, const char *evt);
+       void (*hook_evt_push_before)(void *closure, const char *evt);
+       void (*hook_evt_push_after)(void *closure, const char *evt, int result);
+       void (*hook_evt_broadcast_before)(void *closure, const char *evt);
+       void (*hook_evt_broadcast_after)(void *closure, const char *evt, int result);
+       void (*hook_evt_drop)(void *closure, const char *evt);
+       void (*hook_evt_name)(void *closure, const char *evt);
+};
+
+extern void afb_hook_evt_create(const char *evt);
+extern void afb_hook_evt_push_before(const char *evt);
+extern int afb_hook_evt_push_after(const char *evt, int result);
+extern void afb_hook_evt_broadcast_before(const char *evt);
+extern int afb_hook_evt_broadcast_after(const char *evt, int result);
+extern void afb_hook_evt_drop(const char *evt);
+extern void afb_hook_evt_name(const char *evt);
+
+extern int afb_hook_flags_evt(const char *name);
+extern struct afb_hook_evt *afb_hook_create_evt(const char *name, int flags, struct afb_hook_evt_itf *itf, void *closure);
+extern struct afb_hook_evt *afb_hook_addref_evt(struct afb_hook_evt *hook);
+extern void afb_hook_unref_evt(struct afb_hook_evt *hook);
+#endif