Add hooking for events

Change-Id: If5fe736e04c9f4298302c3cbba568f1d6346ee67
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

8 files changed, 468 insertions, 27 deletions

diff --git a/bindings/samples/HelloWorld.c b/bindings/samples/HelloWorld.c
index e2f38ee4..0f58a43b 100644
--- a/bindings/samples/HelloWorld.c
+++ b/bindings/samples/HelloWorld.c
@@ -109,6 +109,13 @@ static int event_push(struct json_object *args, const char *tag)
 	return e ? afb_event_push(e->event, json_object_get(args)) : -1;
 }
 
+static int event_broadcast(struct json_object *args, const char *tag)
+{
+	struct event *e;
+	e = event_get(tag);
+	return e ? afb_event_broadcast(e->event, json_object_get(args)) : -1;
+}
+
 // Sample Generic Ping Debug API
 static void ping(afb_req request, json_object *jresp, const char *tag)
 {
@@ -359,6 +366,31 @@ static void exitnow (afb_req request)
 	exit(code);
 }
 
+static void broadcast(afb_req request)
+{
+	const char *tag = afb_req_value(request, "tag");
+	const char *name = afb_req_value(request, "name");
+	const char *data = afb_req_value(request, "data");
+	json_object *object = data ? json_tokener_parse(data) : NULL;
+
+	if (tag != NULL) {
+		pthread_mutex_lock(&mutex);
+		if (0 > event_broadcast(object, tag))
+			afb_req_fail(request, "failed", "broadcast error");
+		else
+			afb_req_success(request, NULL, NULL);
+		pthread_mutex_unlock(&mutex);
+	} else if (name != NULL) {
+		if (0 > afb_daemon_broadcast_event(name, object))
+			afb_req_fail(request, "failed", "broadcast error");
+		else
+			afb_req_success(request, NULL, NULL);
+	} else {
+		afb_req_fail(request, "failed", "bad arguments");
+	}
+	json_object_put(object);
+}
+
 static int preinit()
 {
 	NOTICE("hello binding comes to live");
@@ -395,6 +427,7 @@ static const afb_verb_v2 verbs[]= {
   { "call",         call       , NULL, AFB_SESSION_NONE },
   { "callsync",     callsync   , NULL, AFB_SESSION_NONE },
   { "verbose",      verbose    , NULL, AFB_SESSION_NONE },
+  { "broadcast",    broadcast  , NULL, AFB_SESSION_NONE },
   { "exit",         exitnow    , NULL, AFB_SESSION_NONE },
   { NULL}
 };
diff --git a/src/afb-config.c b/src/afb-config.c
index dc3388e4..98dd4e55 100644
--- a/src/afb-config.c
+++ b/src/afb-config.c
@@ -87,6 +87,7 @@
 
 #define ADD_CALL           'c'
 #define SET_TRACEDITF      'D'
+#define SET_TRACEEVT       'E'
 #define SET_EXEC           'e'
 #define DISPLAY_HELP       'h'
 #define SET_QUIET          'q'
@@ -99,7 +100,7 @@
 #define SET_VERBOSE        'v'
 #define SET_WORK_DIR       'w'
 
-#define SHORTOPTS	"c:D:ehqrT:t:u:Vvw:"
+#define SHORTOPTS	"c:D:E:ehqrT:t:u:Vvw:"
 
 // Command line structure hold cli --command + help text
 typedef struct {
@@ -154,6 +155,8 @@ static AFB_options cliOptions[] = {
 	{SET_TRACEREQ,      1, "tracereq",    "Log the requests: no, common, extra, all"},
 	{SET_TRACEDITF,     1, "traceditf",   "Log the requests: no, common, extra, all"},
 	{SET_TRACESVC,      1, "tracesvc",    "Log the requests: no, all"},
+	{SET_TRACEEVT,      1, "traceevt",    "Log the requests: no, common, extra, all"},
+
 	{ADD_CALL,          1, "call",        "call at start format of val: API/VERB:json-args"},
 
 	{SET_NO_HTTPD,      0, "no-httpd",    "Forbids HTTP service"},
@@ -192,6 +195,14 @@ static struct enumdesc tracesvc_desc[] = {
 	{ NULL, 0 }
 };
 
+static struct enumdesc traceevt_desc[] = {
+	{ "no",     0 },
+	{ "common", afb_hook_flags_evt_common },
+	{ "extra",  afb_hook_flags_evt_extra },
+	{ "all",    afb_hook_flags_evt_all },
+	{ NULL, 0 }
+};
+
 static struct enumdesc mode_desc[] = {
 	{ "local",  AFB_MODE_LOCAL },
 	{ "remote", AFB_MODE_REMOTE },
@@ -518,6 +529,10 @@ static void parse_arguments(int argc, char **argv, struct afb_config *config)
 			config->tracesvc = argvalenum(optc, tracesvc_desc);
 			break;
 
+		case SET_TRACEEVT:
+			config->traceevt = argvalenum(optc, traceevt_desc);
+			break;
+
 		case SET_NO_HTTPD:
 			noarg(optc);
 			config->noHttpd = 1;
diff --git a/src/afb-config.h b/src/afb-config.h
index acf1f38f..4ff5d141 100644
--- a/src/afb-config.h
+++ b/src/afb-config.h
@@ -57,6 +57,7 @@ struct afb_config {
 	int tracereq;
 	int traceditf;
 	int tracesvc;
+	int traceevt;
 	int noHttpd;
 };
 
diff --git a/src/afb-evt.c b/src/afb-evt.c
index 7b7ce4f3..d80af045 100644
--- a/src/afb-evt.c
+++ b/src/afb-evt.c
@@ -28,6 +28,7 @@
 #include <afb/afb-event-itf.h>
 
 #include "afb-evt.h"
+#include "afb-hook.h"
 #include "verbose.h"
 
 struct afb_evt_watch;
@@ -70,6 +71,9 @@ struct afb_evt_event {
 	/* id of the event */
 	int id;
 
+	/* hooking */
+	int hookflags;
+
 	/* mutex of the event */
 	pthread_mutex_t mutex;
 
@@ -123,41 +127,56 @@ static int event_id_counter = 0;
 static int event_id_wrapped = 0;
 
 /*
- * Broadcasts the event 'evt' with its 'object'
- * 'object' is released (like json_object_put)
- * Returns the count of listener that received the event.
- */
-static int evt_broadcast(struct afb_evt_event *evt, struct json_object *object)
-{
-	return afb_evt_broadcast(evt->name, object);
-}
-
-/*
- * Broadcasts the 'event' with its 'object'
- * 'object' is released (like json_object_put)
+ * Broadcasts the 'event' of 'id' with its 'obj'
+ * 'obj' is released (like json_object_put)
+ * calls hooks if hookflags isn't 0
  * Returns the count of listener having receive the event.
  */
-int afb_evt_broadcast(const char *event, struct json_object *object)
+static int broadcast(const char *event, struct json_object *obj, int id, int hookflags)
 {
 	int result;
 	struct afb_evt_listener *listener;
 
+	if (hookflags & afb_hook_flag_evt_broadcast_before)
+		afb_hook_evt_broadcast_before(event, id, obj);
 	result = 0;
 	pthread_mutex_lock(&listeners_mutex);
 	listener = listeners;
 	while(listener) {
 		if (listener->itf->broadcast != NULL) {
-			listener->itf->broadcast(listener->closure, event, 0, json_object_get(object));
+			listener->itf->broadcast(listener->closure, event, id, json_object_get(obj));
 			result++;
 		}
 		listener = listener->next;
 	}
 	pthread_mutex_unlock(&listeners_mutex);
-	json_object_put(object);
+	if (hookflags & afb_hook_flag_evt_broadcast_after)
+		afb_hook_evt_broadcast_after(event, id, obj, result);
+	json_object_put(obj);
 	return result;
 }
 
 /*
+ * Broadcasts the event 'evt' with its 'object'
+ * 'object' is released (like json_object_put)
+ * Returns the count of listener that received the event.
+ */
+static int evt_broadcast(struct afb_evt_event *evt, struct json_object *object)
+{
+	return broadcast(evt->name, object, evt->id, evt->hookflags);
+}
+
+/*
+ * Broadcasts the 'event' with its 'object'
+ * 'object' is released (like json_object_put)
+ * Returns the count of listener having receive the event.
+ */
+int afb_evt_broadcast(const char *event, struct json_object *object)
+{
+	return broadcast(event, object, 0, -1);
+}
+
+/*
  * Pushes the event 'evt' with 'obj' to its listeners
  * 'obj' is released (like json_object_put)
  * Returns the count of listener taht received the event.
@@ -170,6 +189,8 @@ static int evt_push(struct afb_evt_event *evt, struct json_object *obj)
 
 	result = 0;
 	pthread_mutex_lock(&evt->mutex);
+	if (evt->hookflags & afb_hook_flag_evt_push_before)
+		afb_hook_evt_push_before(evt->name, evt->id, obj);
 	watch = evt->watchs;
 	while(watch) {
 		listener = watch->listener;
@@ -180,6 +201,8 @@ static int evt_push(struct afb_evt_event *evt, struct json_object *obj)
 		}
 		watch = watch->next_by_event;
 	}
+	if (evt->hookflags & afb_hook_flag_evt_push_after)
+		afb_hook_evt_push_after(evt->name, evt->id, obj, result);
 	pthread_mutex_unlock(&evt->mutex);
 	json_object_put(obj);
 	return result;
@@ -190,6 +213,8 @@ static int evt_push(struct afb_evt_event *evt, struct json_object *obj)
  */
 static const char *evt_name(struct afb_evt_event *evt)
 {
+	if (evt->hookflags & afb_hook_flag_evt_name)
+		afb_hook_evt_name(evt->name, evt->id);
 	return evt->name;
 }
 
@@ -256,6 +281,10 @@ static void evt_destroy(struct afb_evt_event *evt)
 				pthread_mutex_unlock(&listener->mutex);
 			}
 
+			/* hook */
+			if (evt->hookflags & afb_hook_flag_evt_drop)
+				afb_hook_evt_drop(evt->name, evt->id);
+
 			/* free */
 			pthread_mutex_destroy(&evt->mutex);
 			free(evt);
@@ -303,6 +332,9 @@ struct afb_event afb_evt_create_event(const char *name)
 	evt->id = event_id_counter;
 	pthread_mutex_init(&evt->mutex, NULL);
 	events = evt;
+	evt->hookflags = afb_hook_flags_evt(evt->name);
+	if (evt->hookflags & afb_hook_flag_evt_create)
+		afb_hook_evt_create(evt->name, evt->id);
 	pthread_mutex_unlock(&events_mutex);
 
 	/* returns the event */
@@ -497,3 +529,16 @@ int afb_evt_remove_watch(struct afb_evt_listener *listener, struct afb_event eve
 	return -1;
 }
 
+/*
+ * update the hooks for events
+ */
+void afb_evt_update_hooks()
+{
+	struct afb_evt_event *evt;
+
+	pthread_mutex_lock(&events_mutex);
+	for (evt = events ; evt ; evt = evt->next)
+		evt->hookflags = afb_hook_flags_evt(evt->name);
+	pthread_mutex_unlock(&events_mutex);
+}
+
diff --git a/src/afb-evt.h b/src/afb-evt.h
index 5b96b93e..2c8da613 100644
--- a/src/afb-evt.h
+++ b/src/afb-evt.h
@@ -44,3 +44,4 @@ extern int afb_evt_event_id(struct afb_event event);
 extern int afb_evt_add_watch(struct afb_evt_listener *listener, struct afb_event event);
 extern int afb_evt_remove_watch(struct afb_evt_listener *listener, struct afb_event event);
 
+extern void afb_evt_update_hooks();
diff --git a/src/afb-hook.c b/src/afb-hook.c
index 6afcd2fb..aa66b5de 100644
--- a/src/afb-hook.c
+++ b/src/afb-hook.c
@@ -23,6 +23,7 @@
 #include <string.h>
 #include <pthread.h>
 #include <unistd.h>
+#include <fnmatch.h>
 
 #include <json-c/json.h>
 
@@ -36,6 +37,7 @@
 #include "afb-xreq.h"
 #include "afb-ditf.h"
 #include "afb-svc.h"
+#include "afb-evt.h"
 #include "verbose.h"
 
 /**
@@ -182,12 +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)
@@ -553,7 +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)
@@ -981,3 +983,304 @@ void afb_hook_unref_svc(struct afb_hook_svc *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
diff --git a/src/afb-hook.h b/src/afb-hook.h
index c1ff8476..91736386 100644
--- a/src/afb-hook.h
+++ b/src/afb-hook.h
@@ -187,14 +187,14 @@ extern void afb_hook_unref_ditf(struct afb_hook_ditf *hook);
 * section hooking svc (service interface)
 *********************************************************/
 
-#define afb_hook_flag_svc_start_before		0x000001
-#define afb_hook_flag_svc_start_after		0x000002
-#define afb_hook_flag_svc_on_event_before	0x000004
-#define afb_hook_flag_svc_on_event_after	0x000008
-#define afb_hook_flag_svc_call			0x000010
-#define afb_hook_flag_svc_call_result		0x000020
-#define afb_hook_flag_svc_callsync		0x000040
-#define afb_hook_flag_svc_callsync_result	0x000080
+#define afb_hook_flag_svc_start_before			0x000001
+#define afb_hook_flag_svc_start_after			0x000002
+#define afb_hook_flag_svc_on_event_before		0x000004
+#define afb_hook_flag_svc_on_event_after		0x000008
+#define afb_hook_flag_svc_call				0x000010
+#define afb_hook_flag_svc_call_result			0x000020
+#define afb_hook_flag_svc_callsync			0x000040
+#define afb_hook_flag_svc_callsync_result		0x000080
 
 #define afb_hook_flags_svc_all		(afb_hook_flag_svc_start_before|afb_hook_flag_svc_start_after\
 					|afb_hook_flag_svc_on_event_before|afb_hook_flag_svc_on_event_after\
@@ -226,3 +226,44 @@ extern struct afb_hook_svc *afb_hook_create_svc(const char *api, int flags, stru
 extern struct afb_hook_svc *afb_hook_addref_svc(struct afb_hook_svc *hook);
 extern void afb_hook_unref_svc(struct afb_hook_svc *hook);
 
+/*********************************************************
+* section hooking evt (event interface)
+*********************************************************/
+
+#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_name				0x000020
+#define afb_hook_flag_evt_drop				0x000040
+
+#define afb_hook_flags_evt_common	(afb_hook_flag_evt_push_before|afb_hook_flag_evt_broadcast_before)
+#define afb_hook_flags_evt_extra	(afb_hook_flags_evt_common\
+					|afb_hook_flag_evt_push_after|afb_hook_flag_evt_broadcast_after\
+					|afb_hook_flag_evt_create|afb_hook_flag_evt_drop)
+#define afb_hook_flags_evt_all		(afb_hook_flags_evt_extra|afb_hook_flag_evt_name)
+
+struct afb_hook_evt_itf {
+	void (*hook_evt_create)(void *closure, const char *evt, int id);
+	void (*hook_evt_push_before)(void *closure, const char *evt, int id, struct json_object *obj);
+	void (*hook_evt_push_after)(void *closure, const char *evt, int id, struct json_object *obj, int result);
+	void (*hook_evt_broadcast_before)(void *closure, const char *evt, int id, struct json_object *obj);
+	void (*hook_evt_broadcast_after)(void *closure, const char *evt, int id, struct json_object *obj, int result);
+	void (*hook_evt_name)(void *closure, const char *evt, int id);
+	void (*hook_evt_drop)(void *closure, const char *evt, int id);
+};
+
+extern void afb_hook_evt_create(const char *evt, int id);
+extern void afb_hook_evt_push_before(const char *evt, int id, struct json_object *obj);
+extern int afb_hook_evt_push_after(const char *evt, int id, struct json_object *obj, int result);
+extern void afb_hook_evt_broadcast_before(const char *evt, int id, struct json_object *obj);
+extern int afb_hook_evt_broadcast_after(const char *evt, int id, struct json_object *obj, int result);
+extern void afb_hook_evt_name(const char *evt, int id);
+extern void afb_hook_evt_drop(const char *evt, int id);
+
+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);
+
diff --git a/src/main.c b/src/main.c
index 0e97c8a7..fc1ec13e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -573,6 +573,8 @@ static void start()
 		afb_hook_create_ditf(NULL, config->traceditf, NULL, NULL);
 	if (config->tracesvc)
 		afb_hook_create_svc(NULL, config->tracesvc, NULL, NULL);
+	if (config->traceevt)
+		afb_hook_create_evt(NULL, config->traceevt, NULL, NULL);
 
 	/* load bindings */
 	apiset_start_list(config->dbus_clients, afb_api_dbus_add_client, "the afb-dbus client");