[Cc Jiri Benc]
On Sat, Jun 18, 2016 at 06:38:54PM -0700, pravin shelar wrote:
> On Thu, Jun 16, 2016 at 10:53 PM, Simon Horman
> <simon.hor...@netronome.com> wrote:
> > On Tue, Jun 07, 2016 at 03:45:27PM -0700, pravin shelar wrote:
> >> On Mon, Jun 6, 2016 at 8:08 PM, Simon Horman <simon.hor...@netronome.com>
> >> wrote:
> >> > 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.
> ....
> ....
> >> > 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().
> >>
> >> This does looks bit complex. Can we use other skb metadata like
> >> skb_mac_header_was_set()?
> >
> > Yes, I think that can be made to work if skb->mac_header is unset
> > for l3 packets in netdev_port_receive(). The following is an incremental
> > patch on the entire series. Is this the kind of thing you had in mind?
> >
> > diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
> > index 86f2cfb19de3..42587d5bf894 100644
> > --- a/net/openvswitch/flow.c
> > +++ b/net/openvswitch/flow.c
> > @@ -729,7 +729,7 @@ int ovs_flow_key_extract(const struct ip_tunnel_info
> > *tun_info,
> > key->phy.skb_mark = skb->mark;
> > ovs_ct_fill_key(skb, key);
> > key->ovs_flow_hash = 0;
> > - key->phy.is_layer3 = skb->mac_len == 0;
> > + key->phy.is_layer3 = skb_mac_header_was_set(skb) == 0;
> > key->recirc_id = 0;
> >
> > err = key_extract(skb, key);
> > diff --git a/net/openvswitch/vport-internal_dev.c
> > b/net/openvswitch/vport-internal_dev.c
> > index 484ba529c682..8973d4db509b 100644
> > --- a/net/openvswitch/vport-internal_dev.c
> > +++ b/net/openvswitch/vport-internal_dev.c
> > @@ -50,7 +50,6 @@ static int internal_dev_xmit(struct sk_buff *skb, struct
> > net_device *netdev)
> >
> > skb->protocol = eth_type_trans(skb, netdev);
> > skb_push(skb, ETH_HLEN);
> > - skb_reset_mac_len(skb);
> >
> > len = skb->len;
> > rcu_read_lock();
> > diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c
> > index 3df36df62ee9..4cf3f12ffc99 100644
> > --- a/net/openvswitch/vport-netdev.c
> > +++ b/net/openvswitch/vport-netdev.c
> > @@ -60,22 +60,9 @@ static void netdev_port_receive(struct sk_buff *skb)
> > if (vport->dev->type == ARPHRD_ETHER) {
> > skb_push(skb, ETH_HLEN);
> > skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
> > - } else if (vport->dev->type == ARPHRD_NONE) {
> > - if (skb->protocol == htons(ETH_P_TEB)) {
> > - __be16 eth_type;
> > -
> > - if (unlikely(skb->len < ETH_HLEN))
> > - goto error;
> > -
> > - 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;
> > - } else {
> > - skb->mac_len = 0;
> > - }
> > + } else if (vport->dev->type == ARPHRD_NONE &&
> > + skb->protocol != htons(ETH_P_TEB)) {
> > + skb->mac_header = (typeof(skb->mac_header))~0U;
> > }
> >
> > ovs_vport_receive(vport, skb, skb_tunnel_info(skb));
>
> This certainly looks better. I was wondering if we can unset the mac
> header offset in L3 tunnel devices itself. So there is no need to have
> this check here.
I think that might be possible for GRE by modifying the following in
__ipgre_rcv().
if (tunnel->dev->type != ARPHRD_NONE)
skb_pop_mac_header(skb);
else
skb_reset_mac_header(skb);
But I am unsure what side effects this might have on other users of the
code.
Jiri, do you have any thoughts on this?
