wifi: mac80211: fix qos on mesh interfaces

When ieee80211_select_queue is called for mesh, the sta pointer is usually
NULL, since the nexthop is looked up much later in the tx path.
Explicitly check for unicast address in that case in order to make qos work
again.

Cc: [e-mail]
Fixes: 50e2ab392919 ("wifi: mac80211: fix queue selection for mesh/OCB interfaces")
Signed-off-by: Felix Fietkau <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Johannes Berg <[e-mail]>

net/mac80211/wme.c

···
 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 			   struct sta_info *sta, struct sk_buff *skb)
 {
+	const struct ethhdr *eth = (void *)skb->data;
 	struct mac80211_qos_map *qos_map;
 	bool qos;
 
···
 	skb_get_hash(skb);
 
 	/* all mesh/ocb stations are required to support WME */
-	if (sta && (sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
-		    sdata->vif.type == NL80211_IFTYPE_OCB))
+	if ((sdata->vif.type == NL80211_IFTYPE_MESH_POINT &&
+	    !is_multicast_ether_addr(eth->h_dest)) ||
+	    (sdata->vif.type == NL80211_IFTYPE_OCB && sta))
 		qos = true;
 	else if (sta)
 		qos = sta->sta.wme;