veth: move loopback logic to common location

The veth driver contains code to forward an skb
from the start_xmit function of one network
device into the receive path of another device.

Moving that code into a common location lets us
reuse the code for direct forwarding of data
between macvlan ports, and possibly in other
drivers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnd Bergmann 2009-11-26 06:07:08 +00:00 committed by David S. Miller
parent 1bda8aa86b
commit 445409602c
3 changed files with 45 additions and 14 deletions

View file

@ -155,8 +155,6 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
struct veth_net_stats *stats, *rcv_stats;
int length, cpu;
skb_orphan(skb);
priv = netdev_priv(dev);
rcv = priv->peer;
rcv_priv = netdev_priv(rcv);
@ -168,20 +166,12 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
if (!(rcv->flags & IFF_UP))
goto tx_drop;
if (skb->len > (rcv->mtu + MTU_PAD))
goto rx_drop;
skb->tstamp.tv64 = 0;
skb->pkt_type = PACKET_HOST;
skb->protocol = eth_type_trans(skb, rcv);
if (dev->features & NETIF_F_NO_CSUM)
skb->ip_summed = rcv_priv->ip_summed;
skb->mark = 0;
secpath_reset(skb);
nf_reset(skb);
length = skb->len;
length = skb->len + ETH_HLEN;
if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
goto rx_drop;
stats->tx_bytes += length;
stats->tx_packets++;
@ -189,7 +179,6 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
rcv_stats->rx_bytes += length;
rcv_stats->rx_packets++;
netif_rx(skb);
return NETDEV_TX_OK;
tx_drop:

View file

@ -1562,6 +1562,8 @@ extern int dev_set_mac_address(struct net_device *,
extern int dev_hard_start_xmit(struct sk_buff *skb,
struct net_device *dev,
struct netdev_queue *txq);
extern int dev_forward_skb(struct net_device *dev,
struct sk_buff *skb);
extern int netdev_budget;

View file

@ -105,6 +105,7 @@
#include <net/dst.h>
#include <net/pkt_sched.h>
#include <net/checksum.h>
#include <net/xfrm.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/kmod.h>
@ -1419,6 +1420,45 @@ static inline void net_timestamp(struct sk_buff *skb)
skb->tstamp.tv64 = 0;
}
/**
* dev_forward_skb - loopback an skb to another netif
*
* @dev: destination network device
* @skb: buffer to forward
*
* return values:
* NET_RX_SUCCESS (no congestion)
* NET_RX_DROP (packet was dropped)
*
* dev_forward_skb can be used for injecting an skb from the
* start_xmit function of one device into the receive queue
* of another device.
*
* The receiving device may be in another namespace, so
* we have to clear all information in the skb that could
* impact namespace isolation.
*/
int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
skb_orphan(skb);
if (!(dev->flags & IFF_UP))
return NET_RX_DROP;
if (skb->len > (dev->mtu + dev->hard_header_len))
return NET_RX_DROP;
skb_dst_drop(skb);
skb->tstamp.tv64 = 0;
skb->pkt_type = PACKET_HOST;
skb->protocol = eth_type_trans(skb, dev);
skb->mark = 0;
secpath_reset(skb);
nf_reset(skb);
return netif_rx(skb);
}
EXPORT_SYMBOL_GPL(dev_forward_skb);
/*
* Support routine. Sends outgoing frames to any network
* taps currently in use.