linux-stable/net/dsa/tag_qca.c
Vivien Didelot fe47d56306 net: dsa: factor skb freeing on xmit
As of a86d8becc3 ("net: dsa: Factor bottom tag receive functions"),
the rcv caller frees the original SKB in case or error.

Be symmetric with that and make the xmit caller do the same.

At the same time, fix the checkpatch NULL comparison check:

        CHECK: Comparison to NULL could be written "!nskb"
    #208: FILE: net/dsa/tag_trailer.c:35:
    +	if (nskb == NULL)

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-01 17:34:56 -04:00

116 lines
3.2 KiB
C

/*
* 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)
return NULL;
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->dp->index);
*phdr = htons(hdr);
return skb;
}
static struct sk_buff *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(!pskb_may_pull(skb, QCA_HDR_LEN)))
return NULL;
/* 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))
return NULL;
/* 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->cpu_dp->ds;
if (!ds)
return NULL;
/* Get source port information */
port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK);
if (!ds->ports[port].netdev)
return NULL;
/* Update skb & forward the frame accordingly */
skb->dev = ds->ports[port].netdev;
return skb;
}
const struct dsa_device_ops qca_netdev_ops = {
.xmit = qca_tag_xmit,
.rcv = qca_tag_rcv,
};