mac_sdu_get2
mac_sdu_get2(dsp->ds_mh, NULL, &max_sdu, &multicast_sdu);
mac_sdu_get2(mh, NULL, &sdu, NULL);
mac_sdu_get2(mh, NULL, &sdu, NULL);
extern void mac_sdu_get2(mac_handle_t, uint_t *, uint_t *,
extern void mac_sdu_get2(mac_handle_t, uint_t *, uint_t *,