int link_add(Manager *manager, sd_rtnl_message *message, Link **ret);
void link_drop(Link *link);
-int link_get_address_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata);
int link_address_drop_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata);
int link_route_drop_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata);