qcacmn: Add check to discard multicast echo packets

The bridge forwards the multicast packets to all the
interfaces attached the bridge.

When the STA network interface receives such packets
from bridge and send it to the AP, it is echoed back
from the BSS.

These packets are not intended for the bridge as it
will lead to looping.

Add a check to detect and drop such packets when
received back from the BSS.

Refactor dp_rx_mcast_echo_check function to fix
compilation errors from the above change.

CRs-Fixed: 2894272
Change-Id: I3f9e92c3598af11d3ff4e6b9b8afbc4110a926fc

dp/wifi3.0/dp_rx.c

@@ -2271,6 +2271,33 @@ void dp_rx_deliver_to_pkt_capture_no_peer(struct dp_soc *soc, qdf_nbuf_t nbuf,
 
 #endif
 
+#if defined(FEATURE_MCL_REPEATER) && defined(FEATURE_MEC)
+/**
+ * dp_rx_mec_check_wrapper() - wrapper to dp_rx_mcast_echo_check
+ * @soc: core DP main context
+ * @peer: dp peer handler
+ * @rx_tlv_hdr: start of the rx TLV header
+ * @nbuf: pkt buffer
+ *
+ * Return: bool (true if it is a looped back pkt else false)
+ */
+static inline bool dp_rx_mec_check_wrapper(struct dp_soc *soc,
+					   struct dp_peer *peer,
+					   uint8_t *rx_tlv_hdr,
+					   qdf_nbuf_t nbuf)
+{
+	return dp_rx_mcast_echo_check(soc, peer, rx_tlv_hdr, nbuf);
+}
+#else
+static inline bool dp_rx_mec_check_wrapper(struct dp_soc *soc,
+					   struct dp_peer *peer,
+					   uint8_t *rx_tlv_hdr,
+					   qdf_nbuf_t nbuf)
+{
+	return false;
+}
+#endif
+
 /**
  * dp_rx_process() - Brain of the Rx processing functionality
  *		     Called from the bottom half (tasklet/NET_RX_SOFTIRQ)
@@ -2933,6 +2960,18 @@ done:
 					tid_stats->intrabss_cnt++;
 					continue; /* Get next desc */
 				}
+
+			if (qdf_unlikely(dp_rx_mec_check_wrapper(soc,
+								 peer,
+								 rx_tlv_hdr,
+								 nbuf))) {
+				/* this is a looped back MCBC pkt,drop it */
+				DP_STATS_INC_PKT(peer, rx.mec_drop, 1,
+						 QDF_NBUF_CB_RX_PKT_LEN(nbuf));
+				qdf_nbuf_free(nbuf);
+				nbuf = next;
+				continue;
+			}
 		}
 
 		dp_rx_fill_gro_info(soc, rx_tlv_hdr, nbuf, &rx_ol_pkt_cnt);