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net: Separate out SKB validation logic from transmit path. 

dev_hard_start_xmit() does two things, it first validates and
canonicalizes the SKB, then it actually sends it.

Make a set of helper functions for doing the first part.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2014-08-30 15:17:13 -07:00
parent 95f6b3dda2
commit eae3f88ee4
1 changed files with 76 additions and 59 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

135
net/core/dev.c
View File

@ -2644,80 +2644,97 @@ static struct sk_buff *xmit_list(struct sk_buff *first, struct net_device *dev,
return skb;
}
struct sk_buff *validate_xmit_vlan(struct sk_buff *skb, netdev_features_t features)
{
if (vlan_tx_tag_present(skb) &&
!vlan_hw_offload_capable(features, skb->vlan_proto)) {
skb = __vlan_put_tag(skb, skb->vlan_proto,
vlan_tx_tag_get(skb));
if (skb)
skb->vlan_tci = 0;
}
return skb;
}
static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev)
{
netdev_features_t features;
if (skb->next)
return skb;
/* If device doesn't need skb->dst, release it right now while
* its hot in this cpu cache
*/
if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
skb_dst_drop(skb);
features = netif_skb_features(skb);
skb = validate_xmit_vlan(skb, features);
if (unlikely(!skb))
goto out_null;
/* If encapsulation offload request, verify we are testing
* hardware encapsulation features instead of standard
* features for the netdev
*/
if (skb->encapsulation)
features &= dev->hw_enc_features;
if (netif_needs_gso(skb, features)) {
if (unlikely(dev_gso_segment(skb, features)))
goto out_kfree_skb;
} else {
if (skb_needs_linearize(skb, features) &&
__skb_linearize(skb))
goto out_kfree_skb;
/* If packet is not checksummed and device does not
* support checksumming for this protocol, complete
* checksumming here.
*/
if (skb->ip_summed == CHECKSUM_PARTIAL) {
if (skb->encapsulation)
skb_set_inner_transport_header(skb,
skb_checksum_start_offset(skb));
else
skb_set_transport_header(skb,
skb_checksum_start_offset(skb));
if (!(features & NETIF_F_ALL_CSUM) &&
skb_checksum_help(skb))
goto out_kfree_skb;
}
}
return skb;
out_kfree_skb:
kfree_skb(skb);
out_null:
return NULL;
}
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
struct netdev_queue *txq)
{
int rc = NETDEV_TX_OK;
if (likely(!skb->next)) {
netdev_features_t features;
/*
* If device doesn't need skb->dst, release it right now while
* its hot in this cpu cache
*/
if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
skb_dst_drop(skb);
features = netif_skb_features(skb);
if (vlan_tx_tag_present(skb) &&
!vlan_hw_offload_capable(features, skb->vlan_proto)) {
skb = __vlan_put_tag(skb, skb->vlan_proto,
vlan_tx_tag_get(skb));
if (unlikely(!skb))
goto out;
skb->vlan_tci = 0;
}
/* If encapsulation offload request, verify we are testing
* hardware encapsulation features instead of standard
* features for the netdev
*/
if (skb->encapsulation)
features &= dev->hw_enc_features;
if (netif_needs_gso(skb, features)) {
if (unlikely(dev_gso_segment(skb, features)))
goto out_kfree_skb;
if (skb->next)
goto gso;
} else {
if (skb_needs_linearize(skb, features) &&
__skb_linearize(skb))
goto out_kfree_skb;
/* If packet is not checksummed and device does not
* support checksumming for this protocol, complete
* checksumming here.
*/
if (skb->ip_summed == CHECKSUM_PARTIAL) {
if (skb->encapsulation)
skb_set_inner_transport_header(skb,
skb_checksum_start_offset(skb));
else
skb_set_transport_header(skb,
skb_checksum_start_offset(skb));
if (!(features & NETIF_F_ALL_CSUM) &&
skb_checksum_help(skb))
goto out_kfree_skb;
}
}
skb = validate_xmit_skb(skb, dev);
if (!skb)
return rc;
if (likely(!skb->next))
return xmit_one(skb, dev, txq, false);
}
gso:
skb->next = xmit_list(skb->next, dev, txq, &rc);
if (likely(skb->next == NULL)) {
skb->destructor = DEV_GSO_CB(skb)->destructor;
consume_skb(skb);
return rc;
}
out_kfree_skb:
kfree_skb(skb);
out:
return rc;
}
EXPORT_SYMBOL_GPL(dev_hard_start_xmit);