ieee80211_compute_duration
overhead = ieee80211_compute_duration(ic->ic_rt,
dur = ieee80211_compute_duration(ic->ic_rt, pktlen, rate, isshort)
rt->info[i].lpAckDuration = ieee80211_compute_duration(rt,
rt->info[i].spAckDuration = ieee80211_compute_duration(rt,
uint16_t ieee80211_compute_duration(const struct ieee80211_rate_table *,
frame_time = ieee80211_compute_duration(ic->ic_rt, framelen,