mac80211_hwsim: write TSF timestamp correctly to S1G beacon

S1G beacons are different from normal management beacons, so write
the timestamp to the correct location there.
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200922022818.15855-17-thomas@adapt-ip.com
[rewrite commit message that was not useful after patch reordering]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -1687,9 +1687,19 @@ static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
 	mgmt = (struct ieee80211_mgmt *) skb->data;
 	/* fake header transmission time */
 	data->abs_bcn_ts = mac80211_hwsim_get_tsf_raw();
-	mgmt->u.beacon.timestamp = cpu_to_le64(data->abs_bcn_ts +
-					       data->tsf_offset +
-					       24 * 8 * 10 / txrate->bitrate);
+	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
+		struct ieee80211_ext *ext = (void *) mgmt;
+
+		ext->u.s1g_beacon.timestamp = cpu_to_le32(data->abs_bcn_ts +
+							  data->tsf_offset +
+							  10 * 8 * 10 /
+							  txrate->bitrate);
+	} else {
+		mgmt->u.beacon.timestamp = cpu_to_le64(data->abs_bcn_ts +
+						       data->tsf_offset +
+						       24 * 8 * 10 /
+						       txrate->bitrate);
+	}
 
 	mac80211_hwsim_tx_frame(hw, skb,
 				rcu_dereference(vif->chanctx_conf)->def.chan);