EEM_HLEN
if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
(headroom >= EEM_HLEN) && !skb_cloned(skb))
skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
if (skb->len < EEM_HLEN) {
skb_pull(skb, EEM_HLEN);
eem->port.header_len = EEM_HLEN;