mac80211: eliminate IBSS warning in rate_lowest_index()

In IBSS mode prior to join/creation of new IBSS it is possible that
a frame from unknown station is received and an ibss_add_sta() is
called. This will cause a warning in rate_lowest_index() since the
list of supported rates of our station is not initialized yet.

The fix is to add ibss stations with a rate we received that frame
at; this single-element set will be extended later based on beacon
data. Also there is no need to store stations from a foreign IBSS.

Signed-off-by: Vladimir Koutny <vlado@ksp.sk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index e80336f..c32a0bc 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1823,8 +1823,13 @@
 		if (!bssid)
 			return 0;
 		if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT &&
-		    (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON)
+		    (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_BEACON) {
+			if (!rx->sta)
+				rx->sta = ieee80211_ibss_add_sta(sdata->dev,
+						rx->skb, bssid, hdr->addr2,
+						BIT(rx->status->rate_idx));
 			return 1;
+		}
 		else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
 			if (!(rx->flags & IEEE80211_RX_IN_SCAN))
 				return 0;
@@ -1837,7 +1842,8 @@
 			rx->flags &= ~IEEE80211_RX_RA_MATCH;
 		} else if (!rx->sta)
 			rx->sta = ieee80211_ibss_add_sta(sdata->dev, rx->skb,
-							 bssid, hdr->addr2);
+						bssid, hdr->addr2,
+						BIT(rx->status->rate_idx));
 		break;
 	case IEEE80211_IF_TYPE_MESH_POINT:
 		if (!multicast &&