Loggers specify what log messages they want to receive during registration.

This also allows us to generate the log message only once for all
loggers that need it (avoids calls to custom printf specifier callbacks).

To update the log levels loggers can simply be registered again.

src/libcharon/control/controller.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Tobias Brunner
+ * Copyright (C) 2011-2012 Tobias Brunner
  * Copyright (C) 2007-2011 Martin Willi
  * Copyright (C) 2011 revosec AG
  * Hochschule fuer Technik Rapperswil
@@ -199,11 +199,11 @@ static bool wait_for_listener(interface_listener_t *listener, job_t *job,
 
 METHOD(logger_t, listener_log, void,
 	interface_logger_t *this, debug_t group, level_t level, int thread,
-	ike_sa_t *ike_sa, char* format, va_list args)
+	ike_sa_t *ike_sa, char* message)
 {
 	if (this->listener->ike_sa == ike_sa)
 	{
-		if (!this->callback(this->param, group, level, ike_sa, format, args))
+		if (!this->callback(this->param, group, level, ike_sa, message))
 		{
 			this->listener->status = NEED_MORE;
 			listener_done(this->listener);
@@ -211,6 +211,14 @@ METHOD(logger_t, listener_log, void,
 	}
 }
 
+METHOD(logger_t, listener_get_level, level_t,
+	interface_logger_t *this, debug_t group)
+{
+	/* in order to allow callback listeners to decide what they want to log
+	 * we request any log message, but only if we actually want logging */
+	return this->callback == controller_cb_empty ? LEVEL_SILENT : LEVEL_PRIVATE;
+}
+
 METHOD(job_t, get_priority_medium, job_priority_t,
 	job_t *this)
 {
@@ -350,6 +358,7 @@ METHOD(controller_t, initiate, status_t,
 			.logger = {
 				.public = {
 					.log = _listener_log,
+					.get_level = _listener_get_level,
 				},
 				.callback = callback,
 				.param = param,
@@ -416,6 +425,7 @@ METHOD(controller_t, terminate_ike, status_t,
 			.logger = {
 				.public = {
 					.log = _listener_log,
+					.get_level = _listener_get_level,
 				},
 				.callback = callback,
 				.param = param,
@@ -494,6 +504,7 @@ METHOD(controller_t, terminate_child, status_t,
 			.logger = {
 				.public = {
 					.log = _listener_log,
+					.get_level = _listener_get_level,
 				},
 				.callback = callback,
 				.param = param,
@@ -560,7 +571,7 @@ METHOD(controller_t, terminate_child, status_t,
  * See header
  */
 bool controller_cb_empty(void *param, debug_t group, level_t level,
-						 ike_sa_t *ike_sa, char *format, va_list args)
+						 ike_sa_t *ike_sa, char *message)
 {
 	return TRUE;
 }

src/libcharon/control/controller.h

@@ -24,27 +24,26 @@
 #include <bus/bus.h>
 
 /**
- * callback to log things triggered by controller.
+ * Callback to log things triggered by controller.
  *
- * @param param			echoed parameter supplied when function invoked
+ * @param param			parameter supplied when controller method was called
  * @param group			debugging group
- * @param level			verbosity level if log
+ * @param level			verbosity level
  * @param ike_sa		associated IKE_SA, if any
- * @param format		printf like format string
- * @param args			list of arguments to use for format
- * @return				FALSE to return from invoked function
+ * @param message		log message
+ * @return				FALSE to return from called controller method
  */
 typedef bool (*controller_cb_t)(void* param, debug_t group, level_t level,
-								ike_sa_t* ike_sa, char* format, va_list args);
+								ike_sa_t* ike_sa, char* message);
 
 /**
- * Empty callback function for controller_t functions.
+ * Empty callback function for controller_t methods.
  *
  * If you want to do a synchronous call, but don't need a callback, pass
- * this function to the controllers methods.
+ * this function to the controller methods.
  */
 bool controller_cb_empty(void *param, debug_t group, level_t level,
-						 ike_sa_t *ike_sa, char *format, va_list args);
+						 ike_sa_t *ike_sa, char *message);
 
 typedef struct controller_t controller_t;