sasl_server_add_plugin
LIBSASL_API int sasl_server_add_plugin(const char *plugname,
add_plugin = (add_plugin_t *)sasl_server_add_plugin;
sasl_server_add_plugin("EXTERNAL", &external_server_plug_init);
{ "sasl_server_plug_init", (add_plugin_t *)sasl_server_add_plugin },