staging: rtl8723au: validate_recv_data_frame() use fctl knowledge to obtain bssid

Use the knowledge we already have from parsing the TODS/FROMDS bits in
hdr->frame_control to obtain the bssid.

Note that get_hdr_bssid() would never return NULL as handling 4
combinations of a 2 bit word leaves little space for falling through
to the 'default' value.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723au/core/rtw_recv.c

@@ -1308,9 +1308,8 @@ static int validate_recv_data_frame(struct rtw_adapter *adapter,
 				    struct recv_frame *precv_frame)
 {
 	u8 bretry;
-	u8 *psa, *pda, *pbssid;
+	u8 *psa, *pda;
 	struct sta_info *psta = NULL;
-	u8 *ptr = precv_frame->pkt->data;
 	struct rx_pkt_attrib *pattrib = & precv_frame->attrib;
 	struct security_priv *psecuritypriv = &adapter->securitypriv;
 	int ret = _SUCCESS;
@@ -1322,39 +1321,39 @@ static int validate_recv_data_frame(struct rtw_adapter *adapter,
 	bretry = ieee80211_has_retry(hdr->frame_control);
 	pda = ieee80211_get_DA(hdr);
 	psa = ieee80211_get_SA(hdr);
-	pbssid = get_hdr_bssid(ptr);
-
-	if (pbssid == NULL) {
-		ret = _FAIL;
-		goto exit;
-	}
 
 	ether_addr_copy(pattrib->dst, pda);
 	ether_addr_copy(pattrib->src, psa);
 
-	ether_addr_copy(pattrib->bssid, pbssid);
-
 	switch (hdr->frame_control &
 		cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
 	case cpu_to_le16(0):
+		ether_addr_copy(pattrib->bssid, hdr->addr3);
 		ether_addr_copy(pattrib->ra, pda);
 		ether_addr_copy(pattrib->ta, psa);
 		ret = sta2sta_data_frame(adapter, precv_frame, &psta);
 		break;
 
 	case cpu_to_le16(IEEE80211_FCTL_FROMDS):
+		ether_addr_copy(pattrib->bssid, hdr->addr2);
 		ether_addr_copy(pattrib->ra, pda);
-		ether_addr_copy(pattrib->ta, pbssid);
+		ether_addr_copy(pattrib->ta, hdr->addr2);
 		ret = ap2sta_data_frame(adapter, precv_frame, &psta);
 		break;
 
 	case cpu_to_le16(IEEE80211_FCTL_TODS):
-		ether_addr_copy(pattrib->ra, pbssid);
+		ether_addr_copy(pattrib->bssid, hdr->addr1);
+		ether_addr_copy(pattrib->ra, hdr->addr1);
 		ether_addr_copy(pattrib->ta, psa);
 		ret = sta2ap_data_frame(adapter, precv_frame, &psta);
 		break;
 
 	case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
+		/*
+		 * There is no BSSID in this case, but the driver has been
+		 * using addr1 so far, so keep it for now.
+		 */
+		ether_addr_copy(pattrib->bssid, hdr->addr1);
 		ether_addr_copy(pattrib->ra, hdr->addr1);
 		ether_addr_copy(pattrib->ta, hdr->addr2);
 		ret = _FAIL;