cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

tag_trailer.c (1350B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * net/dsa/tag_trailer.c - Trailer tag format handling
      4 * Copyright (c) 2008-2009 Marvell Semiconductor
      5 */
      6
      7#include <linux/etherdevice.h>
      8#include <linux/list.h>
      9#include <linux/slab.h>
     10
     11#include "dsa_priv.h"
     12
     13static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev)
     14{
     15	struct dsa_port *dp = dsa_slave_to_port(dev);
     16	u8 *trailer;
     17
     18	trailer = skb_put(skb, 4);
     19	trailer[0] = 0x80;
     20	trailer[1] = 1 << dp->index;
     21	trailer[2] = 0x10;
     22	trailer[3] = 0x00;
     23
     24	return skb;
     25}
     26
     27static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev)
     28{
     29	u8 *trailer;
     30	int source_port;
     31
     32	if (skb_linearize(skb))
     33		return NULL;
     34
     35	trailer = skb_tail_pointer(skb) - 4;
     36	if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
     37	    (trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00)
     38		return NULL;
     39
     40	source_port = trailer[1] & 7;
     41
     42	skb->dev = dsa_master_find_slave(dev, 0, source_port);
     43	if (!skb->dev)
     44		return NULL;
     45
     46	if (pskb_trim_rcsum(skb, skb->len - 4))
     47		return NULL;
     48
     49	return skb;
     50}
     51
     52static const struct dsa_device_ops trailer_netdev_ops = {
     53	.name	= "trailer",
     54	.proto	= DSA_TAG_PROTO_TRAILER,
     55	.xmit	= trailer_xmit,
     56	.rcv	= trailer_rcv,
     57	.needed_tailroom = 4,
     58};
     59
     60MODULE_LICENSE("GPL");
     61MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_TRAILER);
     62
     63module_dsa_tag_driver(trailer_netdev_ops);