Add logging by request

Change-Id: I6dda714bcb8c36392c14a1981cfb8960f3db45b8
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

11 files changed, 258 insertions, 23 deletions

diff --git a/bindings/samples/HelloWorld.c b/bindings/samples/HelloWorld.c
index 09c7d3e7..68af5fc6 100644
--- a/bindings/samples/HelloWorld.c
+++ b/bindings/samples/HelloWorld.c
@@ -325,9 +325,39 @@ static void callsync (struct afb_req request)
 	}
 }
 
+static void verbose (struct afb_req request)
+{
+	int level = 5;
+	json_object *query = afb_req_json(request), *l;
+
+	if (json_object_is_type(query,json_type_int))
+		level = json_object_get_int(query);
+	else if (json_object_object_get_ex(query, "level", &l) && json_object_is_type(l, json_type_int))
+		level = json_object_get_int(l);
+
+	if (!json_object_object_get_ex(query,"message",&l))
+		l = query;
+
+	AFB_REQ_VERBOSE(request, level, "verbose called for %s", json_object_get_string(l));
+	afb_req_success(request, NULL, NULL);
+}
+
 static void exitnow (struct afb_req request)
 {
-	exit(0);
+	int code = 0;
+	json_object *query = afb_req_json(request), *l;
+
+	if (json_object_is_type(query,json_type_int))
+		code = json_object_get_int(query);
+	else if (json_object_object_get_ex(query, "code", &l) && json_object_is_type(l, json_type_int))
+		code = json_object_get_int(l);
+
+	if (!json_object_object_get_ex(query,"reason",&l))
+		l = NULL;
+
+	REQ_NOTICE(request, "in phase of exiting with code %d, reason: %s", code, l ? json_object_get_string(l) : "unknown");
+	afb_req_success(request, NULL, NULL);
+	exit(code);
 }
 
 static int preinit()
@@ -365,6 +395,7 @@ static const struct afb_verb_v2 verbs[]= {
   { "eventpush",    eventpush  , NULL, AFB_SESSION_NONE },
   { "call",         call       , NULL, AFB_SESSION_NONE },
   { "callsync",     callsync   , NULL, AFB_SESSION_NONE },
+  { "verbose",      verbose    , NULL, AFB_SESSION_NONE },
   { "exit",         exitnow    , NULL, AFB_SESSION_NONE },
   { NULL}
 };
diff --git a/include/afb/afb-binding-v1.h b/include/afb/afb-binding-v1.h
index b627d5c4..ef03a6b0 100644
--- a/include/afb/afb-binding-v1.h
+++ b/include/afb/afb-binding-v1.h
@@ -147,20 +147,38 @@ struct afb_binding_interface_v1
  */
 #if !defined(AFB_BINDING_PRAGMA_NO_VERBOSE_MACRO)
 # if !defined(AFB_BINDING_PRAGMA_NO_VERBOSE_DETAILS)
-#  define AFB_ERROR_V1(itf,...)   do{if(itf->verbosity>=0)afb_daemon_verbose(itf->daemon,3,__FILE__,__LINE__,__VA_ARGS__);}while(0)
-#  define AFB_WARNING_V1(itf,...) do{if(itf->verbosity>=1)afb_daemon_verbose(itf->daemon,4,__FILE__,__LINE__,__VA_ARGS__);}while(0)
-#  define AFB_NOTICE_V1(itf,...)  do{if(itf->verbosity>=1)afb_daemon_verbose(itf->daemon,5,__FILE__,__LINE__,__VA_ARGS__);}while(0)
-#  define AFB_INFO_V1(itf,...)    do{if(itf->verbosity>=2)afb_daemon_verbose(itf->daemon,6,__FILE__,__LINE__,__VA_ARGS__);}while(0)
-#  define AFB_DEBUG_V1(itf,...)   do{if(itf->verbosity>=3)afb_daemon_verbose(itf->daemon,7,__FILE__,__LINE__,__VA_ARGS__);}while(0)
+#  define _AFB_LOGGING_V1_(itf,vlevel,llevel,...) \
+	do{ \
+		if(itf->verbosity>=vlevel) \
+			afb_daemon_verbose2_v1(itf->daemon,llevel,__FILE__,__LINE__,__func__,__VA_ARGS__); \
+	}while(0)
+#  define _AFB_REQ_LOGGING_V1_(itf,vlevel,llevel,req,...) \
+	do{ \
+		if(itf->verbosity>=vlevel) \
+			afb_req_verbose(req,llevel,__FILE__,__LINE__,__func__,__VA_ARGS__); \
+	}while(0)
 # else
-#  define AFB_ERROR_V1(itf,...)   do{if(itf->verbosity>=0)afb_daemon_verbose(itf->daemon,3,NULL,0,__VA_ARGS__);}while(0)
-#  define AFB_WARNING_V1(itf,...) do{if(itf->verbosity>=1)afb_daemon_verbose(itf->daemon,4,NULL,0,__VA_ARGS__);}while(0)
-#  define AFB_NOTICE_V1(itf,...)  do{if(itf->verbosity>=1)afb_daemon_verbose(itf->daemon,5,NULL,0,__VA_ARGS__);}while(0)
-#  define AFB_INFO_V1(itf,...)    do{if(itf->verbosity>=2)afb_daemon_verbose(itf->daemon,6,NULL,0,__VA_ARGS__);}while(0)
-#  define AFB_DEBUG_V1(itf,...)   do{if(itf->verbosity>=3)afb_daemon_verbose(itf->daemon,7,NULL,0,__VA_ARGS__);}while(0)
+#  define _AFB_LOGGING_V1_(itf,vlevel,llevel,...) \
+	do{ \
+		if(itf->verbosity>=vlevel) \
+			afb_daemon_verbose_v1(itf->daemon,llevel,NULL,0,NULL,__VA_ARGS__); \
+	}while(0)
+#  define _AFB_REQ_LOGGING_V1_(itf,vlevel,llevel,req,...) \
+	do{ \
+		if(itf->verbosity>=vlevel) \
+			afb_req_verbose(req,llevel,NULL,0,NULL,__VA_ARGS__); \
+	}while(0)
 # endif
+# define AFB_ERROR_V1(itf,...)       _AFB_LOGGING_V1_(itf,0,3,__VA_ARGS__)
+# define AFB_WARNING_V1(itf,...)     _AFB_LOGGING_V1_(itf,1,4,__VA_ARGS__)
+# define AFB_NOTICE_V1(itf,...)      _AFB_LOGGING_V1_(itf,1,5,__VA_ARGS__)
+# define AFB_INFO_V1(itf,...)        _AFB_LOGGING_V1_(itf,2,6,__VA_ARGS__)
+# define AFB_DEBUG_V1(itf,...)       _AFB_LOGGING_V1_(itf,3,7,__VA_ARGS__)
+# define AFB_REQ_ERROR_V1(itf,...)   _AFB_REQ_LOGGING_V1_(itf,0,3,__VA_ARGS__)
+# define AFB_REQ_WARNING_V1(itf,...) _AFB_REQ_LOGGING_V1_(itf,1,4,__VA_ARGS__)
+# define AFB_REQ_NOTICE_V1(itf,...)  _AFB_REQ_LOGGING_V1_(itf,1,5,__VA_ARGS__)
+# define AFB_REQ_INFO_V1(itf,...)    _AFB_REQ_LOGGING_V1_(itf,2,6,__VA_ARGS__)
+# define AFB_REQ_DEBUG_V1(itf,...)   _AFB_REQ_LOGGING_V1_(itf,3,7,__VA_ARGS__)
 #endif
 
 
-
-
diff --git a/include/afb/afb-binding-v2.h b/include/afb/afb-binding-v2.h
index e763f1cf..66601b23 100644
--- a/include/afb/afb-binding-v2.h
+++ b/include/afb/afb-binding-v2.h
@@ -96,18 +96,33 @@ struct afb_binding_data_v2 AFB_BINDING_DATA_NAME_V2  __attribute__ ((weak));
 		if(AFB_BINDING_DATA_NAME_V2.verbosity>=vlevel) \
 			afb_daemon_verbose_v2(llevel,__FILE__,__LINE__,__func__,__VA_ARGS__); \
 	}while(0)
+#  define _AFB_REQ_LOGGING_V2_(vlevel,llevel,req,...) \
+	do{ \
+		if(AFB_BINDING_DATA_NAME_V2.verbosity>=vlevel) \
+			afb_req_verbose(req,llevel,__FILE__,__LINE__,__func__,__VA_ARGS__); \
+	}while(0)
 # else
 #  define _AFB_LOGGING_V2_(vlevel,llevel,...) \
 	do{ \
 		if(afbBindingV2data.verbosity>=vlevel) \
 			afb_daemon_verbose_v2(llevel,NULL,0,NULL,__VA_ARGS__); \
 	}while(0)
+#  define _AFB_REQ_LOGGING_V2_(vlevel,llevel,req,...) \
+	do{ \
+		if(AFB_BINDING_DATA_NAME_V2.verbosity>=vlevel) \
+			afb_req_verbose(req,llevel,NULL,0,NULL,__VA_ARGS__); \
+	}while(0)
 # endif
-# define AFB_ERROR_V2(...)   _AFB_LOGGING_V2_(0,3,__VA_ARGS__)
-# define AFB_WARNING_V2(...) _AFB_LOGGING_V2_(1,4,__VA_ARGS__)
-# define AFB_NOTICE_V2(...)  _AFB_LOGGING_V2_(1,5,__VA_ARGS__)
-# define AFB_INFO_V2(...)    _AFB_LOGGING_V2_(2,6,__VA_ARGS__)
-# define AFB_DEBUG_V2(...)   _AFB_LOGGING_V2_(3,7,__VA_ARGS__)
+# define AFB_ERROR_V2(...)       _AFB_LOGGING_V2_(0,3,__VA_ARGS__)
+# define AFB_WARNING_V2(...)     _AFB_LOGGING_V2_(1,4,__VA_ARGS__)
+# define AFB_NOTICE_V2(...)      _AFB_LOGGING_V2_(1,5,__VA_ARGS__)
+# define AFB_INFO_V2(...)        _AFB_LOGGING_V2_(2,6,__VA_ARGS__)
+# define AFB_DEBUG_V2(...)       _AFB_LOGGING_V2_(3,7,__VA_ARGS__)
+# define AFB_REQ_ERROR_V2(...)   _AFB_REQ_LOGGING_V2_(0,3,__VA_ARGS__)
+# define AFB_REQ_WARNING_V2(...) _AFB_REQ_LOGGING_V2_(1,4,__VA_ARGS__)
+# define AFB_REQ_NOTICE_V2(...)  _AFB_REQ_LOGGING_V2_(1,5,__VA_ARGS__)
+# define AFB_REQ_INFO_V2(...)    _AFB_REQ_LOGGING_V2_(2,6,__VA_ARGS__)
+# define AFB_REQ_DEBUG_V2(...)   _AFB_REQ_LOGGING_V2_(3,7,__VA_ARGS__)
 #endif
 
 #include "afb-daemon-v2.h"
diff --git a/include/afb/afb-binding.h b/include/afb/afb-binding.h
index e2fd34d8..a7872517 100644
--- a/include/afb/afb-binding.h
+++ b/include/afb/afb-binding.h
@@ -102,6 +102,12 @@
 #  define INFO			AFB_INFO_V1
 #  define DEBUG			AFB_DEBUG_V1
 
+#  define REQ_ERROR		AFB_REQ_ERROR_V1
+#  define REQ_WARNING		AFB_REQ_WARNING_V1
+#  define REQ_NOTICE		AFB_REQ_NOTICE_V1
+#  define REQ_INFO		AFB_REQ_INFO_V1
+#  define REQ_DEBUG		AFB_REQ_DEBUG_V1
+
 # endif
 
 #define afb_daemon_get_event_loop	afb_daemon_get_event_loop_v1
@@ -147,6 +153,12 @@
 #  define INFO			AFB_INFO_V2
 #  define DEBUG			AFB_DEBUG_V2
 
+#  define REQ_ERROR		AFB_REQ_ERROR_V2
+#  define REQ_WARNING		AFB_REQ_WARNING_V2
+#  define REQ_NOTICE		AFB_REQ_NOTICE_V2
+#  define REQ_INFO		AFB_REQ_INFO_V2
+#  define REQ_DEBUG		AFB_REQ_DEBUG_V2
+
 # endif
 
 #define afb_daemon_get_event_loop	afb_daemon_get_event_loop_v2
diff --git a/include/afb/afb-daemon-v1.h b/include/afb/afb-daemon-v1.h
index 84095e04..6390dd16 100644
--- a/include/afb/afb-daemon-v1.h
+++ b/include/afb/afb-daemon-v1.h
@@ -74,8 +74,21 @@ static inline struct afb_event afb_daemon_make_event_v1(struct afb_daemon daemon
 /*
  * Send a message described by 'fmt' and following parameters
  * to the journal for the verbosity 'level'.
- * 'file' and 'line' are indicators of position of the code in source files.
+ *
+ * 'file' and 'line' are indicators of position of the code in source files
+ * (see macros __FILE__ and __LINE__).
+ *
  * 'daemon' MUST be the daemon given in interface when activating the binding.
+ *
+ * '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_daemon_verbose_v1(struct afb_daemon daemon, int level, const char *file, int line, const char *fmt, ...) __attribute__((format(printf, 5, 6)));
 static inline void afb_daemon_verbose_v1(struct afb_daemon daemon, int level, const char *file, int line, const char *fmt, ...)
@@ -87,6 +100,34 @@ static inline void afb_daemon_verbose_v1(struct afb_daemon daemon, int level, co
 }
 
 /*
+ * Send 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__).
+ *
+ * 'daemon' MUST be the daemon given in interface when activating the binding.
+ *
+ * '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_daemon_verbose2_v1(struct afb_daemon daemon, int level, const char *file, int line, const char *func, const char *fmt, ...) __attribute__((format(printf, 6, 7)));
+static inline void afb_daemon_verbose2_v1(struct afb_daemon daemon, int level, const char *file, int line, const char *func, const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+	daemon.itf->vverbose_v2(daemon.closure, level, file, line, func, fmt, args);
+	va_end(args);
+}
+
+/*
  * Get the root directory file descriptor. This file descriptor can
  * be used with functions 'openat', 'fstatat', ...
  */
diff --git a/include/afb/afb-daemon-v2.h b/include/afb/afb-daemon-v2.h
index 3ecd763b..6cfc60ba 100644
--- a/include/afb/afb-daemon-v2.h
+++ b/include/afb/afb-daemon-v2.h
@@ -69,7 +69,19 @@ static inline struct afb_event afb_daemon_make_event_v2(const char *name)
 /*
  * Send a message described by 'fmt' and following parameters
  * to the journal for the verbosity 'level'.
- * 'file' and 'line' are indicators of position of the code in source files.
+ *
+ * '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_daemon_verbose_v2(int level, const char *file, int line, const char * func, const char *fmt, ...) __attribute__((format(printf, 5, 6)));
 static inline void afb_daemon_verbose_v2(int level, const char *file, int line, const char * func, const char *fmt, ...)
diff --git a/include/afb/afb-req-itf.h b/include/afb/afb-req-itf.h
index 65f2bfe6..8c18a831 100644
--- a/include/afb/afb-req-itf.h
+++ b/include/afb/afb-req-itf.h
@@ -67,6 +67,8 @@ struct afb_req_itf {
 
 	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);
 };
 
 /*
@@ -390,3 +392,35 @@ static inline int afb_req_subcall_sync(struct afb_req req, const char *api, cons
 	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
diff --git a/src/afb-hook.c b/src/afb-hook.c
index cade990c..6afcd2fb 100644
--- a/src/afb-hook.c
+++ b/src/afb-hook.c
@@ -210,6 +210,24 @@ 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,
@@ -229,6 +247,7 @@ 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
 };
 
 /******************************************************************************
@@ -349,6 +368,11 @@ 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: hooking xreqs
  *****************************************************************************/
diff --git a/src/afb-hook.h b/src/afb-hook.h
index 8fe30d5b..c1ff8476 100644
--- a/src/afb-hook.h
+++ b/src/afb-hook.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#include <stdarg.h>
+
 struct req;
 struct afb_context;
 struct json_object;
@@ -53,6 +55,7 @@ struct afb_hook_xreq;
 #define afb_hook_flag_req_subcall_result	0x010800
 #define afb_hook_flag_req_subcallsync		0x020000
 #define afb_hook_flag_req_subcallsync_result	0x040000
+#define afb_hook_flag_req_vverbose		0x080000
 
 /* common flags */
 #define afb_hook_flags_req_life		(afb_hook_flag_req_begin|afb_hook_flag_req_end)
@@ -69,7 +72,8 @@ struct afb_hook_xreq;
 
 /* predefined groups */
 #define afb_hook_flags_req_common	(afb_hook_flags_req_life|afb_hook_flags_req_args|afb_hook_flags_req_result\
-					|afb_hook_flags_req_session|afb_hook_flags_req_event|afb_hook_flags_req_subcall)
+					|afb_hook_flags_req_session|afb_hook_flags_req_event|afb_hook_flags_req_subcall\
+					|afb_hook_flag_req_vverbose)
 #define afb_hook_flags_req_extra	(afb_hook_flags_req_common|afb_hook_flags_req_ref|afb_hook_flags_req_context)
 #define afb_hook_flags_req_all		(afb_hook_flags_req_extra)
 
@@ -92,6 +96,7 @@ struct afb_hook_xreq_itf {
 	void (*hook_xreq_subcall_result)(void * closure, const struct afb_xreq *xreq, int status, struct json_object *result);
 	void (*hook_xreq_subcallsync)(void * closure, const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args);
 	void (*hook_xreq_subcallsync_result)(void * closure, const struct afb_xreq *xreq, int status, struct json_object *result);
+	void (*hook_xreq_vverbose)(void * closure, const struct afb_xreq *xreq, int level, const char *file, int line, const char *func, const char *fmt, va_list args);
 };
 
 extern void afb_hook_init_xreq(struct afb_xreq *xreq);
@@ -119,6 +124,7 @@ extern void afb_hook_xreq_subcall(const struct afb_xreq *xreq, const char *api,
 extern void afb_hook_xreq_subcall_result(const struct afb_xreq *xreq, int status, struct json_object *result);
 extern void afb_hook_xreq_subcallsync(const struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args);
 extern int afb_hook_xreq_subcallsync_result(const struct afb_xreq *xreq, int status, struct json_object *result);
+extern 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);
 
 /*********************************************************
 * section hooking ditf (daemon interface)
diff --git a/src/afb-xreq.c b/src/afb-xreq.c
index 0b828277..61ba4fd9 100644
--- a/src/afb-xreq.c
+++ b/src/afb-xreq.c
@@ -257,6 +257,12 @@ static int xreq_subcallsync_cb(void *closure, const char *api, const char *verb,
 	return 1;
 }
 
+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);
+}
+
 /******************************************************************************/
 
 static struct json_object *xreq_hooked_json_cb(void *closure)
@@ -397,6 +403,16 @@ static int xreq_hooked_subcallsync_cb(void *closure, const char *api, const char
 	return afb_hook_xreq_subcallsync_result(xreq, r, *result);
 }
 
+static void xreq_hooked_vverbose_cb(void*closure, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
+{
+	struct afb_xreq *xreq = closure;
+	va_list ap;
+	va_copy(ap, args);
+	xreq_vverbose_cb(closure, level, file, line, func, fmt, args);
+	afb_hook_xreq_vverbose(xreq, level, file, line, func, fmt, ap);
+	va_end(ap);
+}
+
 /******************************************************************************/
 
 const struct afb_req_itf xreq_itf = {
@@ -415,7 +431,8 @@ const struct afb_req_itf xreq_itf = {
 	.subscribe = xreq_subscribe_cb,
 	.unsubscribe = xreq_unsubscribe_cb,
 	.subcall = xreq_subcall_cb,
-	.subcallsync = xreq_subcallsync_cb
+	.subcallsync = xreq_subcallsync_cb,
+	.vverbose = xreq_vverbose_cb
 };
 
 const struct afb_req_itf xreq_hooked_itf = {
@@ -434,7 +451,8 @@ const struct afb_req_itf xreq_hooked_itf = {
 	.subscribe = xreq_hooked_subscribe_cb,
 	.unsubscribe = xreq_hooked_unsubscribe_cb,
 	.subcall = xreq_hooked_subcall_cb,
-	.subcallsync = xreq_hooked_subcallsync_cb
+	.subcallsync = xreq_hooked_subcallsync_cb,
+	.vverbose = xreq_hooked_vverbose_cb
 };
 
 static inline struct afb_req to_req(struct afb_xreq *xreq)
diff --git a/src/verbose.h b/src/verbose.h
index 71d5fe1e..6bedc323 100644
--- a/src/verbose.h
+++ b/src/verbose.h
@@ -20,9 +20,33 @@
 
 #include <stdarg.h>
 
+/*
+  verbosity tune the count of reported messages
+
+   verbosity value : reported messages
+   ----------------+------------------------
+    lesser than 0  : no message at all
+         0         : ERROR
+         1         : ERROR, WARNING, NOTICE
+         2         : ERROR, WARNING, NOTICE, INFO
+    greater than 2 : ERROR, WARNING, NOTICE, INFO, DEBUG
+
+*/
 extern int verbosity;
 
 extern void verbose_set_name(const char *name, int authority);
+
+/*
+ Level is defined by syslog standard:
+       KERN_EMERG             0        System is unusable
+       KERN_ALERT             1        Action must be taken immediately
+       KERN_CRIT              2        Critical conditions
+       KERN_ERR               3        Error conditions
+       KERN_WARNING           4        Warning conditions
+       KERN_NOTICE            5        Normal but significant condition
+       KERN_INFO              6        Informational
+       KERN_DEBUG             7        Debug-level messages
+*/
 extern void verbose(int level, const char *file, int line, const char *function, const char *fmt, ...) __attribute__((format(printf, 5, 6)));
 extern void vverbose(int level, const char *file, int line, const char *function, const char *fmt, va_list args);