On receive we call eth_type_trans() to set skb->protocol. However,
that function also sets skb->pkt_type, which requires several
comparisons to MAC addresses. Nothing in OVS cares about pkt_type,
so this is wasteful. If we actually do egress to the IP stack
through an internal device then we'll call eth_type_trans() to get
everything correctly setup. It's possible for device drivers to
see an incorrect pkt_type or not correctly parse legacy IPX (which
eth_type_trans() also handles) but it's highly unlikely that they
will care.
Signed-off-by: Jesse Gross <jesse@nicira.com>
/* Called with rcu_read_lock. */
void tnl_rcv(struct vport *vport, struct sk_buff *skb)
{
/* Called with rcu_read_lock. */
void tnl_rcv(struct vport *vport, struct sk_buff *skb)
{
- skb->pkt_type = PACKET_HOST;
- skb->protocol = eth_type_trans(skb, skb->dev);
+ /* Packets received by this function are in the following state:
+ * - skb->data points to the inner Ethernet header.
+ * - The inner Ethernet header is in the linear data area.
+ * - skb->csum does not include the inner Ethernet header.
+ * - The layer pointers point at the outer headers.
+ */
+
+ struct ethhdr *eh = (struct ethhdr *)skb->data;
+
+ if (likely(ntohs(eh->h_proto) >= 1536))
+ skb->protocol = eh->h_proto;
+ else
+ skb->protocol = htons(ETH_P_802_2);
skb_dst_drop(skb);
nf_reset(skb);
secpath_reset(skb);
skb_dst_drop(skb);
nf_reset(skb);
secpath_reset(skb);
- skb_reset_network_header(skb);
+ skb_set_network_header(skb, ETH_HLEN);
-
- skb_push(skb, ETH_HLEN);
compute_ip_summed(skb, false);
vport_receive(vport, skb);
compute_ip_summed(skb, false);
vport_receive(vport, skb);