l2_packet: Add support for NDISC packet filter in l2_packet_linux

Signed-off-by: Kyeyoon Park <kyeyoonp@qca.qualcomm.com>

src/l2_packet/l2_packet.h

@@ -41,6 +41,7 @@ struct l2_ethhdr {
 
 enum l2_packet_filter_type {
 	L2_PACKET_FILTER_DHCP,
+	L2_PACKET_FILTER_NDISC,
 };
 
 /**

src/l2_packet/l2_packet_linux.c

@@ -56,6 +56,24 @@ static const struct sock_fprog dhcp_sock_filter = {
 };
 
 
+/* Generated by 'sudo tcpdump -dd -s 150 multicast and ip6[6]=58' */
+static struct sock_filter ndisc_sock_filter_insns[] = {
+	{ 0x30, 0, 0, 0x00000000 },
+	{ 0x45, 0, 5, 0x00000001 },
+	{ 0x28, 0, 0, 0x0000000c },
+	{ 0x15, 0, 3, 0x000086dd },
+	{ 0x30, 0, 0, 0x00000014 },
+	{ 0x15, 0, 1, 0x0000003a },
+	{ 0x6, 0, 0, 0x00000096 },
+	{ 0x6, 0, 0, 0x00000000 },
+};
+
+static const struct sock_fprog ndisc_sock_filter = {
+	.len = ARRAY_SIZE(ndisc_sock_filter_insns),
+	.filter = ndisc_sock_filter_insns,
+};
+
+
 int l2_packet_get_own_addr(struct l2_packet_data *l2, u8 *addr)
 {
 	os_memcpy(addr, l2->own_addr, ETH_ALEN);
@@ -240,6 +258,9 @@ int l2_packet_set_packet_filter(struct l2_packet_data *l2,
 	case L2_PACKET_FILTER_DHCP:
 		sock_filter = &dhcp_sock_filter;
 		break;
+	case L2_PACKET_FILTER_NDISC:
+		sock_filter = &ndisc_sock_filter;
+		break;
 	default:
 		return -1;
 	}