NFC: Add support for SO_TIMESTAMP LLCP socket option

Set timestamp in sent and received sk_buffs. timestamp is then put in
msghdr structure in llcp_sock_recvmsg().
Signed-off-by: NThierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

net/nfc/llcp/commands.c

@@ -304,6 +304,8 @@ int nfc_llcp_send_symm(struct nfc_dev *dev)
 
 	skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
 
+	__net_timestamp(skb);
+
 	nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_TX);
 
 	return nfc_data_exchange(dev, local->target_idx, skb,

net/nfc/llcp/llcp.c

@@ -668,6 +668,8 @@ static void nfc_llcp_tx_work(struct work_struct *work)
 			if (ptype == LLCP_PDU_I)
 				copy_skb = skb_copy(skb, GFP_ATOMIC);
 
+			__net_timestamp(skb);
+
 			nfc_llcp_send_to_raw_sock(local, skb,
 						  NFC_LLCP_DIRECTION_TX);
 
@@ -1245,6 +1247,8 @@ static void nfc_llcp_rx_work(struct work_struct *work)
 		print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
 			       16, 1, skb->data, skb->len, true);
 
+	__net_timestamp(skb);
+
 	nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_RX);
 
 	switch (ptype) {

net/nfc/llcp/sock.c

@@ -678,6 +678,8 @@ static int llcp_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 		return -EFAULT;
 	}
 
+	sock_recv_timestamp(msg, sk, skb);
+
 	if (sk->sk_type == SOCK_DGRAM && msg->msg_name) {
 		struct nfc_llcp_ui_cb *ui_cb = nfc_llcp_ui_skb_cb(skb);
 		struct sockaddr_nfc_llcp sockaddr;