mac_header
mp0 = mac_header(mh, sol->sll_addr, sol->sll_protocol, mp, 0);
mp = mac_header(dsp->ds_mh, addr, mac_sap, payload, extra_len);
hdr_mp = mac_header(tsock->ts_link->bl_mh, daddr,
extern mblk_t *mac_header(mac_handle_t, const uint8_t *, uint32_t, mblk_t *,