On 5/7/16 12:32 PM, Shmulik Ladkani wrote:
Hi David,
On Sat, 7 May 2016 08:50:49 -0600 David Ahern <d...@cumulusnetworks.com> wrote:
+static inline
+struct sk_buff *l3mdev_l3_rcv(struct sk_buff *skb, u16 proto)
+{
+ struct net_device *master = NULL;
+
+ if (netif_is_l3_slave(skb->dev))
+ master = netdev_master_upper_dev_get_rcu(skb->dev);
+
+ else if (netif_is_l3_master(skb->dev))
+ master = skb->dev;
+
+ if (master && master->l3mdev_ops->l3mdev_l3_rcv)
+ skb = master->l3mdev_ops->l3mdev_l3_rcv(master, skb, proto);
In the case where netif_is_l3_master(skb->dev) is true, can you explain
why we need to pass it through the l3mdev_l3_rcv callback again?
what do you mean again? This is only time the l3mdev_l3_rcv method is
called on a packet.
You have the following:
if (netif_is_l3_slave(skb->dev))
master = netdev_master_upper_dev_get_rcu(skb->dev);
else if (netif_is_l3_master(skb->dev))
master = skb->dev;
if (master && master->l3mdev_ops->l3mdev_l3_rcv)
skb = master->l3mdev_ops->l3mdev_l3_rcv(master, skb, proto);
So in both conditions (skb->dev being the slave or the master) the skb
is passed to master's l3mdev_l3_rcv callback.
Appreciate if you can elaborate:
- Why callback needs to be invoked when skb->dev is the L3 master?
Every l3mdev_ops has converged on that ordering -- if l3 slave else if
l3 master.
- On which circumstances we end up entering
l3mdev_ip_rcv/l3mdev_ip6_rcv where skb->dev is the master?
If I got it right, we enter 'ip_rcv_finish' on a slave device,
the callback is invoked and eventually sets skb->dev and skb->skb_iif
to the VRF device; then ip_rcv_finish continues processing the
altered skb (with the changed skb->dev).
So on which cicumstances do we enter 'ip_rcv_finish' where the
skb->dev is ALREADY a master device?
If you look at the full patchset I posted on 5/4 the patch after PKTINFO
allows local traffic. That change needs the netif_is_l3_master().
