ng_package_msg
item_p ng_package_msg(struct ng_mesg *msg, int flags);
if ((_item = ng_package_msg(msg, NG_NOFLAGS)) == NULL) {\
if ((_item = ng_package_msg(msg, NG_NOFLAGS)) == NULL) {\
if ((_item = ng_package_msg(msg, NG_NOFLAGS)) == NULL) {\
item = ng_package_msg(msg, NG_WAITOK);