Added a thread save, allocating settings get_str variant called alloc_str

src/libstrongswan/settings.c

@@ -444,6 +444,25 @@ METHOD(settings_t, get_str, char*,
 	return def;
 }
 
+METHOD(settings_t, alloc_str, char*,
+	private_settings_t *this, char *key, char *def, ...)
+{
+	char *value;
+	va_list args;
+
+	va_start(args, def);
+	/* additional lock to savely strdup */
+	this->lock->read_lock(this->lock);
+	value = strdupnull(find_value(this, this->top, key, args));
+	this->lock->unlock(this->lock);
+	va_end(args);
+	if (value)
+	{
+		return value;
+	}
+	return def;
+}
+
 /**
  * Described in header
  */
@@ -1192,6 +1211,7 @@ settings_t *settings_create(char *file)
 	INIT(this,
 		.public = {
 			.get_str = _get_str,
+			.alloc_str = _alloc_str,
 			.get_int = _get_int,
 			.get_double = _get_double,
 			.get_time = _get_time,

src/libstrongswan/settings.h

@@ -146,13 +146,31 @@ struct settings_t {
 	/**
 	 * Get a settings value as a string.
 	 *
+	 * This functions returns a string held by settings_t. It is not thread
+	 * save, a thread calling load_files might free the returned string at
+	 * any time. Use the thread save alloc_str if a different thread might
+	 * call load_files() or set_str().
+	 *
 	 * @param key		key including sections, printf style format
 	 * @param def		value returned if key not found
 	 * @param ...		argument list for key
-	 * @return			value pointing to internal string
+	 * @return			value pointing to internal string, not to be freed
 	 */
 	char* (*get_str)(settings_t *this, char *key, char *def, ...);
 
+	/**
+	 * Get a settings value as a string, thread save variant.
+	 *
+	 * This function is identical to get_str, but is thread save. It allocates
+	 * a copy for the returned string which must be freed.
+	 *
+	 * @param key		key including sections, printf style format
+	 * @param def		value returned if key not found
+	 * @param ...		argument list for key
+	 * @return			allocated string, to be free
+	 */
+	char* (*alloc_str)(settings_t *this, char *key, char *def, ...);
+
 	/**
 	 * Get a boolean yes|no, true|false value.
 	 *