mac80211: support station 4-addr mode fast-rx

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -3747,10 +3747,6 @@ void ieee80211_check_fast_rx(struct sta_info *sta)
 
 	switch (sdata->vif.type) {
 	case NL80211_IFTYPE_STATION:
-		/* 4-addr is harder to deal with, later maybe */
-		if (sdata->u.mgd.use_4addr)
-			goto clear;
-
 		if (sta->sta.tdls) {
 			fastrx.da_offs = offsetof(struct ieee80211_hdr, addr1);
 			fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr2);
@@ -3763,6 +3759,13 @@ void ieee80211_check_fast_rx(struct sta_info *sta)
 				cpu_to_le16(IEEE80211_FCTL_FROMDS);
 		}
 
+		if (sdata->u.mgd.use_4addr && !sta->sta.tdls) {
+			fastrx.expected_ds_bits |=
+				cpu_to_le16(IEEE80211_FCTL_TODS);
+			fastrx.da_offs = offsetof(struct ieee80211_hdr, addr3);
+			fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr4);
+		}
+
 		if (!sdata->u.mgd.powersave)
 			break;