On Thu, Jun 02, 2016 at 03:01:47PM -0700, pravin shelar wrote: > On Wed, Jun 1, 2016 at 11:24 PM, Simon Horman > <simon.hor...@netronome.com> wrote: > > * Set skb protocol based on contents of packet. I have observed this is > > necessary to get actual protocol of a packet when it is injected into an > > internal device e.g. by libnet in which case skb protocol will be set to > > ETH_ALL. > > > > * Set the mac_len which has been observed to not be set up correctly when > > an ARP packet is generated and sent via an openvswitch bridge. > > My test case is a scenario where there are two open vswtich bridges. > > One outputs to a tunnel port which egresses on the other. > > > > The motivation for this is that support for outputting to layer 3 (non-tap) > > GRE tunnels as implemented by a subsequent patch depends on protocol and > > mac_len being set correctly on receive. > > > > Signed-off-by: Simon Horman <simon.hor...@netronome.com> > > > > --- > > v10 > > * Set mac_len > > > > v9 > > * New patch > > --- > > net/openvswitch/vport-internal_dev.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/net/openvswitch/vport-internal_dev.c > > b/net/openvswitch/vport-internal_dev.c > > index 2ee48e447b72..f89b1efa88f1 100644 > > --- a/net/openvswitch/vport-internal_dev.c > > +++ b/net/openvswitch/vport-internal_dev.c > > @@ -48,6 +48,10 @@ static int internal_dev_xmit(struct sk_buff *skb, struct > > net_device *netdev) > > { > > int len, err; > > > > + skb->protocol = eth_type_trans(skb, netdev); > > + skb_push(skb, ETH_HLEN); > > + skb_reset_mac_len(skb); > > + > resetting mac-len breaks the assumption about mac_len for referencing > MPLS header ref: skb_mpls_header().
Thanks I had overlooked this. I think it is actually safe as the mac_len is recalculated quite soon in key_extract() and IIRC the most important thing is for mac_len to be 0 or non-zero for the benefit of ovs_flow_key_extract(). None the less it does seem untidy and moreover inconsistent with the handling in netdev_port_receive() by a latter patch which does the following: eth_type = eth_type_trans(skb, skb->dev); skb->mac_len = skb->data - skb_mac_header(skb); __skb_push(skb, skb->mac_len); if (eth_type == htons(ETH_P_8021Q)) skb->mac_len += VLAN_HLEN; Perhaps that logic ought to be in a helper used by both internal_dev_xmit() and netdev_port_receive(). Or somehow centralised in ovs_vport_receive().