// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2013 - 2018 Intel Corporation. */

#include "fm10k.h"

/**
 * ies_type_trans - determine packet's protocol ID and insert IES header
 * @skb: received data buffer
 *
 * This function is like eth_type_trans but for ies-tagged packets.  The
 * result of this function is that the IES header stored in the context
 * block is transferred to the start of the frame and the mac header is
 * padded to account for it.
 */
__be16 ies_type_trans(struct sk_buff *skb)
{
	__be64 *ies;

	/* perform some basic accounting to cleanup and prep sk_buff */
	skb_reset_mac_header(skb);
	skb->pkt_type = PACKET_OTHERHOST;

	/* create room for IES header */
	BUG_ON((skb_mac_header(skb) - skb->head) < (sizeof(struct fm10k_ies)));
	skb->mac_header -= sizeof(struct fm10k_ies);
	ies = (__be64 *)skb_mac_header(skb);

	/* Place the timestamp and FTAG in the newly allocated space */
	ies[0] = cpu_to_be64(le64_to_cpu(FM10K_CB(skb)->tstamp));
	ies[1] = cpu_to_be64(le64_to_cpu(FM10K_CB(skb)->fi.ftag));

	/* return our own proprietary protocol */
	return htons(ETH_P_IES);
}

static int ies_rcv(struct sk_buff *skb, struct net_device __always_unused *dev,
		   struct packet_type __always_unused *pt,
		   struct net_device __always_unused *orig_dev)
{
	/* free the skb, as there is no real protocol to handle it */
	dev_kfree_skb(skb);

	return 0;
}

struct packet_type ies_packet_type __read_mostly = {
	.type = htons(ETH_P_IES),
	.func = ies_rcv,
};