IEEE802154_MFR_SIZE  316 net/ieee802154/header_ops.c 	return IEEE802154_MTU - hlen - IEEE802154_MFR_SIZE;
IEEE802154_MFR_SIZE  721 net/mac802154/llsec.c 	if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)