From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 23 Feb 2018 10:05:08 +0100
Subject: [PATCH] mac80211: support station 4-addr mode fast-rx

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

--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -160,7 +160,6 @@ static int ieee80211_change_iface(struct
 	if (type == NL80211_IFTYPE_AP_VLAN &&
 	    params && params->use_4addr == 0) {
 		RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
-		ieee80211_check_fast_rx_iface(sdata);
 	} else if (type == NL80211_IFTYPE_STATION &&
 		   params && params->use_4addr >= 0) {
 		sdata->u.mgd.use_4addr = params->use_4addr;
@@ -1574,7 +1573,6 @@ static int ieee80211_change_station(stru
 			}
 
 			rcu_assign_pointer(vlansdata->u.vlan.sta, sta);
-			__ieee80211_check_fast_rx_iface(vlansdata);
 		}
 
 		if (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3738,10 +3738,6 @@ void ieee80211_check_fast_rx(struct 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);
@@ -3754,6 +3750,13 @@ void ieee80211_check_fast_rx(struct 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;