tag_qca.c
3.58 KB
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/*
* Copyright (c) 2015, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/etherdevice.h>
#include "dsa_priv.h"
#define QCA_HDR_LEN 2
#define QCA_HDR_VERSION 0x2
#define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14)
#define QCA_HDR_RECV_VERSION_S 14
#define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11)
#define QCA_HDR_RECV_PRIORITY_S 11
#define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6)
#define QCA_HDR_RECV_TYPE_S 6
#define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3)
#define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
#define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14)
#define QCA_HDR_XMIT_VERSION_S 14
#define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11)
#define QCA_HDR_XMIT_PRIORITY_S 11
#define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8)
#define QCA_HDR_XMIT_CONTROL_S 8
#define QCA_HDR_XMIT_FROM_CPU BIT(7)
#define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0)
static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct dsa_slave_priv *p = netdev_priv(dev);
u16 *phdr, hdr;
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
if (skb_cow_head(skb, 0) < 0)
goto out_free;
skb_push(skb, QCA_HDR_LEN);
memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN);
phdr = (u16 *)(skb->data + 2 * ETH_ALEN);
/* Set the version field, and set destination port information */
hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S |
QCA_HDR_XMIT_FROM_CPU |
BIT(p->port);
*phdr = htons(hdr);
return skb;
out_free:
kfree_skb(skb);
return NULL;
}
static int qca_tag_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct dsa_switch_tree *dst = dev->dsa_ptr;
struct dsa_switch *ds;
u8 ver;
int port;
__be16 *phdr, hdr;
if (unlikely(!dst))
goto out_drop;
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb)
goto out;
if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN)))
goto out_drop;
/* The QCA header is added by the switch between src addr and Ethertype
* At this point, skb->data points to ethertype so header should be
* right before
*/
phdr = (__be16 *)(skb->data - 2);
hdr = ntohs(*phdr);
/* Make sure the version is correct */
ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S;
if (unlikely(ver != QCA_HDR_VERSION))
goto out_drop;
/* Remove QCA tag and recalculate checksum */
skb_pull_rcsum(skb, QCA_HDR_LEN);
memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN,
ETH_HLEN - QCA_HDR_LEN);
/* This protocol doesn't support cascading multiple switches so it's
* safe to assume the switch is first in the tree
*/
ds = dst->ds[0];
if (!ds)
goto out_drop;
/* Get source port information */
port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
if (!ds->ports[port].netdev)
goto out_drop;
/* Update skb & forward the frame accordingly */
skb_push(skb, ETH_HLEN);
skb->pkt_type = PACKET_HOST;
skb->dev = ds->ports[port].netdev;
skb->protocol = eth_type_trans(skb, skb->dev);
skb->dev->stats.rx_packets++;
skb->dev->stats.rx_bytes += skb->len;
netif_receive_skb(skb);
return 0;
out_drop:
kfree_skb(skb);
out:
return 0;
}
const struct dsa_device_ops qca_netdev_ops = {
.xmit = qca_tag_xmit,
.rcv = qca_tag_rcv,
};