netdev - [PATCH net-next v11 3/6] openvswitch: set skb protocol and mac

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Date:	Wed,  6 Jul 2016 19:59:53 +0200
From:	Simon Horman <simon.horman@...ronome.com>
To:	netdev@...r.kernel.org
Cc:	dev@...nvswitch.org
Subject: [PATCH net-next v11 3/6] openvswitch: set skb protocol and mac_len when receiving on internal device

* 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.horman@...ronome.com>

---
v11
* Do not set mac_len.
  Instead of relying on mac_len follow-up patches now
  use skb_unset_mac_header()

v10
* Set mac_len

v9
* New patch
---
 net/openvswitch/vport-internal_dev.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
index 434e04c3a189..32d8e94d9bff 100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -48,6 +48,9 @@ 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);
+
 	len = skb->len;
 	rcu_read_lock();
 	err = ovs_vport_receive(internal_dev_priv(netdev)->vport, skb, NULL);
-- 
2.7.0.rc3.207.g0ac5344