userspace: Switching of L3 packets in L2 pipeline

Ports have a new layer3 attribute if they send/receive L3 packets.

The packet_type included in structs dp_packet and flow is considered in
ofproto-dpif. The classical L2 match fields (dl_src, dl_dst, dl_type, and
vlan_tci, vlan_vid, vlan_pcp) now have Ethernet as pre-requisite.

A dummy ethernet header is pushed to L3 packets received from L3 ports
before the the pipeline processing starts. The ethernet header is popped
before sending a packet to a L3 port.

For datapath ports that can receive L2 or L3 packets, the packet_type
becomes part of the flow key for datapath flows and is handled
appropriately in dpif-netdev.

In the 'else' branch in flow_put_on_pmd() function, the additional check
flow_equal(&match.flow, &netdev_flow->flow) was removed, as a) the dpcls
lookup is sufficient to uniquely identify a flow and b) it caused false
negatives because the flow in netdev->flow may not properly masked.

In dpif_netdev_flow_put() we now use the same method for constructing the
netdev_flow_key as the one used when adding the flow to the dplcs to make sure
these always match. The function netdev_flow_key_from_flow() used so far was
not only inefficient but sometimes caused mismatches and subsequent flow
update failures.

The kernel datapath does not support the packet_type match field.
Instead it encodes the packet type implictly by the presence or absence of
the Ethernet attribute in the flow key and mask.
This patch filters the PACKET_TYPE attribute out of netlink flow key and
mask to be sent to the kernel datapath.

Signed-off-by: Lorand Jakab <lojakab@cisco.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Signed-off-by: Jan Scheurich <jan.scheurich@ericsson.com>
Co-authored-by: Zoltan Balogh <zoltan.balogh@ericsson.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

lib/netdev.h

@@ -100,6 +100,7 @@ struct netdev_tunnel_config {
 
     bool csum;
     bool dont_fragment;
+    bool is_layer3;
 };
 
 void netdev_run(void);