blob: 22742a53d6f42fef709955c2a7fc8f52812b0c8e [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* net/dsa/tag_trailer.c - Trailer tag format handling
* Copyright (c) 2008-2009 Marvell Semiconductor
*/
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/slab.h>
#include "tag.h"
#define TRAILER_NAME "trailer"
static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct dsa_port *dp = dsa_user_to_port(dev);
u8 *trailer;
trailer = skb_put(skb, 4);
trailer[0] = 0x80;
trailer[1] = 1 << dp->index;
trailer[2] = 0x10;
trailer[3] = 0x00;
return skb;
}
static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev)
{
u8 *trailer;
int source_port;
if (skb_linearize(skb))
return NULL;
trailer = skb_tail_pointer(skb) - 4;
if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
(trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00)
return NULL;
source_port = trailer[1] & 7;
skb->dev = dsa_conduit_find_user(dev, 0, source_port);
if (!skb->dev)
return NULL;
if (pskb_trim_rcsum(skb, skb->len - 4))
return NULL;
return skb;
}
static const struct dsa_device_ops trailer_netdev_ops = {
.name = TRAILER_NAME,
.proto = DSA_TAG_PROTO_TRAILER,
.xmit = trailer_xmit,
.rcv = trailer_rcv,
.needed_tailroom = 4,
};
MODULE_DESCRIPTION("DSA tag driver for switches using a trailer tag");
MODULE_LICENSE("GPL");
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_TRAILER, TRAILER_NAME);
module_dsa_tag_driver(trailer_netdev_ops);