qcacmn: Donot forward MDNS packets for NAN vdev

MDNS packets if forwarded for a NAN vdev can lead to potential flooding
of the air interface. Hence donot forward them.

Change-Id: Idfdedfb0b5b553745440587448230013f3b56a7d
CRs-Fixed: 2503360

qdf/linux/src/i_qdf_nbuf.h

@@ -777,6 +777,7 @@ bool __qdf_nbuf_data_is_ipv6_udp_pkt(uint8_t *data);
 bool __qdf_nbuf_data_is_ipv6_tcp_pkt(uint8_t *data);
 bool __qdf_nbuf_data_is_ipv4_dhcp_pkt(uint8_t *data);
 bool __qdf_nbuf_data_is_ipv6_dhcp_pkt(uint8_t *data);
+bool __qdf_nbuf_data_is_ipv6_mdns_pkt(uint8_t *data);
 bool __qdf_nbuf_data_is_ipv4_eapol_pkt(uint8_t *data);
 bool __qdf_nbuf_data_is_ipv4_arp_pkt(uint8_t *data);
 bool __qdf_nbuf_is_bcast_pkt(__qdf_nbuf_t nbuf);

qdf/linux/src/qdf_nbuf.c

@@ -1790,6 +1790,35 @@ bool __qdf_nbuf_data_is_ipv6_dhcp_pkt(uint8_t *data)
 }
 qdf_export_symbol(__qdf_nbuf_data_is_ipv6_dhcp_pkt);
 
+/**
+ * __qdf_nbuf_data_is_ipv6_mdns_pkt() - check if skb data is a mdns packet
+ * @data: Pointer to network data buffer
+ *
+ * This api is for ipv6 packet.
+ *
+ * Return: true if packet is MDNS packet
+ *	   false otherwise
+ */
+bool __qdf_nbuf_data_is_ipv6_mdns_pkt(uint8_t *data)
+{
+	uint16_t sport;
+	uint16_t dport;
+
+	sport = *(uint16_t *)(data + QDF_NBUF_TRAC_IPV6_OFFSET +
+				QDF_NBUF_TRAC_IPV6_HEADER_SIZE);
+	dport = *(uint16_t *)(data + QDF_NBUF_TRAC_IPV6_OFFSET +
+					QDF_NBUF_TRAC_IPV6_HEADER_SIZE +
+					sizeof(uint16_t));
+
+	if (sport == QDF_SWAP_U16(QDF_NBUF_TRAC_MDNS_SRC_N_DST_PORT) &&
+	    dport == sport)
+		return true;
+	else
+		return false;
+}
+
+qdf_export_symbol(__qdf_nbuf_data_is_ipv6_mdns_pkt);
+
 /**
  * __qdf_nbuf_data_is_ipv4_mcast_pkt() - check if it is IPV4 multicast packet.
  * @data: Pointer to IPV4 packet data buffer