From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 23 Feb 2018 10:00:22 +0100
Subject: [PATCH] mac80211: support AP 4-addr mode fast-rx

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3774,6 +3774,15 @@ void ieee80211_check_fast_rx(struct sta_
 			!(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
 			(sdata->vif.type != NL80211_IFTYPE_AP_VLAN ||
 			 !sdata->u.vlan.sta);
+
+		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+		    sdata->u.vlan.sta) {
+			fastrx.expected_ds_bits |=
+				cpu_to_le16(IEEE80211_FCTL_FROMDS);
+			fastrx.sa_offs = offsetof(struct ieee80211_hdr, addr4);
+			fastrx.internal_forward = 0;
+		}
+
 		break;
 	default:
 		goto clear;