| Message ID | 1354827296-12009-2-git-send-email-gallatin@myri.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2012-12-06 at 15:54 -0500, Andrew Gallatin wrote: > This patch copies the vlan device's dev->features to its > dev->vlan_features, which allows packets to arrive at > vlan_dev_hard_start_xmit() with their offloads intact. > > When a packet destined for a vlan interface is transmitted, it passes > through dev_hard_start_xmit() (and netif_skb_features()) twice. First > on its way to vlan_dev_hard_start_xmit(), and then again on its way to > the backing device's xmit handler. If the vlan device does not setup > its dev->vlan_features, then netif_skb_features() will strip the > features on the first trip through it (on the way to > vlan_dev_hard_start_xmit()). > > Signed-off-by: Andrew Gallatin <gallatin@myri.com> > --- > net/8021q/vlan_dev.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c > index 4a6d31a..9d4b3c9 100644 > --- a/net/8021q/vlan_dev.c > +++ b/net/8021q/vlan_dev.c > @@ -559,6 +559,7 @@ static int vlan_dev_init(struct net_device *dev) > > dev->features |= real_dev->vlan_features | NETIF_F_LLTX; > dev->gso_max_size = real_dev->gso_max_size; > + dev->vlan_features = dev->features; To repeat myself: no, this will result in the features being transferred to VLAN devices stacked on top of this one (to an arbitrary depth!). Ben. > /* ipv6 shared card related stuff */ > dev->dev_id = real_dev->dev_id;
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 4a6d31a..9d4b3c9 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -559,6 +559,7 @@ static int vlan_dev_init(struct net_device *dev) dev->features |= real_dev->vlan_features | NETIF_F_LLTX; dev->gso_max_size = real_dev->gso_max_size; + dev->vlan_features = dev->features; /* ipv6 shared card related stuff */ dev->dev_id = real_dev->dev_id;
This patch copies the vlan device's dev->features to its dev->vlan_features, which allows packets to arrive at vlan_dev_hard_start_xmit() with their offloads intact. When a packet destined for a vlan interface is transmitted, it passes through dev_hard_start_xmit() (and netif_skb_features()) twice. First on its way to vlan_dev_hard_start_xmit(), and then again on its way to the backing device's xmit handler. If the vlan device does not setup its dev->vlan_features, then netif_skb_features() will strip the features on the first trip through it (on the way to vlan_dev_hard_start_xmit()). Signed-off-by: Andrew Gallatin <gallatin@myri.com> --- net/8021q/vlan_dev.c | 1 + 1 file changed, 1 insertion(+)