qcacmn: Do Multicast Echo Check for Multicast pkts only

Add a check to ensure MEC happens only for multicast
and broadcast pkts only. Also added additional check to
drop the mcbc pkt whose src MAC addr matches to the rx vdev.
This is in addition to the other MEC checks already in place.
CRs-Fixed: 2097918

Change-Id: Ie41fce0368cd6147c2a3678f8f4b31eb400f933c

dp/wifi3.0/dp_rx_err.c

@@ -356,10 +356,34 @@ dp_rx_null_q_desc_handle(struct dp_soc *soc, struct dp_rx_desc *rx_desc,
 	qdf_nbuf_pull_head(nbuf, (l2_hdr_offset + RX_PKT_TLVS_LEN));
 
 	/*
-	 * This is a Multicast echo check, drop the pkt if we meet
-	 * the Multicast Echo Check condition
+	 * Multicast Echo Check is required only if vdev is STA and
+	 * received pkt is a multicast/broadcast pkt. otherwise
+	 * skip the MEC check.
 	 */
+	if (vdev->opmode != wlan_op_mode_sta)
+		goto skip_mec_check;
+
+	if (!hal_rx_msdu_end_da_is_mcbc_get(rx_desc->rx_buf_start))
+		goto skip_mec_check;
+
 	data = qdf_nbuf_data(nbuf);
+	/*
+	 * if the received pkts src mac addr matches with vdev
+	 * mac address then drop the pkt as it is looped back
+	 */
+	if (!(memcmp(&data[DP_MAC_ADDR_LEN],
+			vdev->mac_addr.raw,
+			DP_MAC_ADDR_LEN))) {
+
+		qdf_nbuf_free(nbuf);
+		goto fail;
+	}
+
+	/* if the received pkts src mac addr matches with the
+	 * wired PCs MAC addr which is behind the STA or with
+	 * wireless STAs MAC addr which are behind the Repeater,
+	 * then drop the pkt as it is looped back
+	 */
 	qdf_spin_lock_bh(&soc->ast_lock);
 	if (hal_rx_msdu_end_sa_is_valid_get(rx_desc->rx_buf_start)) {
 		sa_idx = hal_rx_msdu_end_sa_idx_get(rx_desc->rx_buf_start);
@@ -389,6 +413,7 @@ dp_rx_null_q_desc_handle(struct dp_soc *soc, struct dp_rx_desc *rx_desc,
 	}
 	qdf_spin_unlock_bh(&soc->ast_lock);
 
+skip_mec_check:
 	/* WDS Source Port Learning */
 	if (qdf_likely(vdev->rx_decap_type == htt_cmn_pkt_type_ethernet))
 		dp_rx_wds_srcport_learn(soc, rx_desc->rx_buf_start, peer, nbuf);