On 06/02/14 at 01:43pm, Simon Horman wrote:
> +#ifdef CONFIG_NET_MPLS_GSO
> +static netdev_features_t net_mpls_features(struct sk_buff *skb,
> + struct net_device *dev,
> + netdev_features_t features)
> +{
> + /* There is no support for MPLS LRO. So the only way that
> + * an MPLS skb could require GSO segmentation is if it
> + * was received as a non-MPLS skb and then became an MPLS skb.
> + * This may be effected by Open vSwitch in which case the
> + * mac_len will non-zero and not equal to skb_network_offset
> + * as the former indicates the end of L2 while the latter indicates
> + * the beginning of L3 and there is a gap between them occupied
> + * by the MPLS label stack.
> + *
> + * Thus it is possible to avoid traversing any VLAN tags that are
> + * present to determine if the ethtype is MPLS. Instead the
> + * inequality of mac_len and skb_network_offset are used to
> + * determine if a packet is MPLS for the purpose of determining
> + * offload features.
> + */
> + if (skb->mac_len && skb->mac_len != skb_network_offset(skb))
> + features &= dev->mpls_features;
> + return features;
> +}
Could you elaborate a bit on the safety of this? What about
GRE GSO which sets mac_len to the inner network offset?
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
