ieee80211_add_ssid
frm = ieee80211_add_ssid(frm, NULL, 0);
frm = ieee80211_add_ssid(frm, NULL, 0);
frm = ieee80211_add_ssid(frm, NULL, 0);
frm = ieee80211_add_ssid(frm, ssid, ssidlen);
frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
frm = ieee80211_add_ssid(frm, bss->ni_essid, bss->ni_esslen);
uint8_t *ieee80211_add_ssid(uint8_t *, const uint8_t *, u_int);
data = ieee80211_add_ssid(data, p->ssid, strlen(p->ssid));