net: dsa: Refactor transmit path to eliminate duplication
All tagging protocols do the same thing: increment device statistics,
make room for the tag to be inserted, create the tag, invoke the parent
network device transmit function.
In order to prepare for adding netpoll support, which requires the tag
creation, but not using the parent network device transmit function, do
some little refactoring which eliminates duplication between the 4
tagging protocols supported.
We need to return a sk_buff pointer back to the caller because the tag
specific transmit function may have to reallocate the original skb (e.g:
tag_trailer.c) and this is the one we should be transmitting, not the
original sk_buff we were passed.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 0917123..5fc87ee 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -421,21 +421,32 @@
static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct dsa_slave_priv *p = netdev_priv(dev);
+ struct sk_buff *nskb;
- return p->xmit(skb, dev);
-}
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
-static netdev_tx_t dsa_slave_notag_xmit(struct sk_buff *skb,
- struct net_device *dev)
-{
- struct dsa_slave_priv *p = netdev_priv(dev);
+ /* Transmit function may have to reallocate the original SKB */
+ nskb = p->xmit(skb, dev);
+ if (!nskb)
+ return NETDEV_TX_OK;
- skb->dev = p->parent->dst->master_netdev;
- dev_queue_xmit(skb);
+ /* Queue the SKB for transmission on the parent interface, but
+ * do not modify its EtherType
+ */
+ nskb->dev = p->parent->dst->master_netdev;
+ dev_queue_xmit(nskb);
return NETDEV_TX_OK;
}
+static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ /* Just return the original SKB */
+ return skb;
+}
+
/* ethtool operations *******************************************************/
static int