Allow access to connection in object server

Allow connection object to be accessed out of the dbus_interface. See
#83 for reference.

Similar pattern to asio's get_executor() method exposed on sockets.

Can reduce parameter count when working in code where the dbus_interface
is passed around. When components register their own interface onto
a preexisting dbus_interface but require access to the connection
or the connections underlying execution context.

Change-Id: Ie9df1f2762f639de60b492255d6f9d85920b0fd6
Signed-off-by: Ómar Högni Guðmarsson <[email protected]>

Author: omsigum

include/sdbusplus/asio/object_server.hpp

@@ -398,6 +398,12 @@ class dbus_interface
                                        std::vector<std::string>{name_});
     }
 
+    auto connection() const noexcept
+        -> std::shared_ptr<sdbusplus::asio::connection>
+    {
+        return conn_;
+    }
+
     template <typename PropertyType, typename CallbackTypeGet>
     bool register_property_r(const std::string& name,
                              const PropertyType& property,