On Mon, 20 Jul 2020 22:15:51 +0530
Sriram Krishnan [off-list ref] wrote:

 
+	/* When using AF_PACKET we need to remove VLAN from frame
+	 * and indicate VLAN information in SKB so HOST OS will
+	 * transmit the VLAN frame
+	 */
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		u16 vlan_tci = 0;
+		skb_reset_mac_header(skb);
+		if (eth_type_vlan(eth_hdr(skb)->h_proto)) {
+			int pop_err;
+			pop_err = __skb_vlan_pop(skb, &vlan_tci);
+			if (likely(pop_err == 0)) {
+				__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci);
+
+				/* Update the NDIS header pkt lengths */
+				packet->total_data_buflen -= VLAN_HLEN;
+				rndis_msg->msg_len = packet->total_data_buflen;
+				rndis_msg->msg.pkt.data_len = packet->total_data_buflen;
+
+			} else {
+				netdev_err(net,"Pop vlan err %x\n",pop_err);
+			}
+		}
+	}

Minor comments.

1. Blank line between declaration and code.
2. Error handling is different than other parts of this code.
   probably just need a goto drop on error.

It seems like you are putting into message, then driver is putting
it into meta-data in next code block. Maybe it should be combined?