sk_tx_desc
static void sk_txcksum(if_t, struct mbuf *, struct sk_tx_desc *);
sk_txcksum(if_t ifp, struct mbuf *m, struct sk_tx_desc *f)
struct sk_tx_desc *f = NULL;
struct sk_tx_desc *cur_tx;
bzero(rd->sk_tx_ring, sizeof(struct sk_tx_desc) * SK_TX_RING_CNT);
struct sk_tx_desc *sk_tx_ring;
((sc)->sk_rdata.sk_tx_ring_paddr + sizeof(struct sk_tx_desc) * (i))
(sizeof(struct sk_tx_desc) * SK_TX_RING_CNT)