NL80211_ATTR_BEACON_TAIL
if (attrs[NL80211_ATTR_BEACON_TAIL]) {
bcn->tail = nla_data(attrs[NL80211_ATTR_BEACON_TAIL]);
bcn->tail_len = nla_len(attrs[NL80211_ATTR_BEACON_TAIL]);
[NL80211_ATTR_BEACON_TAIL] =