openvswitch: support for layer 3 encapsulated packets

At the core of this patch set is removing the assumption in Open vSwitch datapath that all packets have Ethernet header.

The implementation relies on the presence of pop_eth and push_eth actions in datapath flows to facilitate adding and removing Ethernet headers as appropriate. The construction of such flows is left up to user-space.

This series is based on work by Simon Horman, Lorand Jakab, Thomas Morin and others. I kept Lorand's and Simon's s-o-b in the patches that are derived from v11 to record their authorship of parts of the code.

Changes from v12 to v13:

* Addressed Pravin's feedback.
* Removed the GRE vport conversion patch; L3 GRE ports should be created by rtnetlink instead.

Main changes from v11 to v12:

* The patches were restructured and split differently for easier review.
* They were rebased and adjusted to the current net-next. Especially MPLS handling is different (and easier) thanks to the recent MPLS GSO rework.
* Several bugs were discovered and fixed. The most notable is fragment
handling: header adjustment for ARPHRD_NONE devices on tx needs to be done after refragmentation, not before it. This required significant changes in the patchset. Another one is stricter checking of attributes (match on L2 vs. L3 packet) at the kernel level.
* Instead of is_layer3 bool, a mac_proto field is used.

Jiri Benc (8):
openvswitch: use hard_header_len instead of hardcoded ETH_HLEN
openvswitch: add mac_proto field to the flow key
openvswitch: pass mac_proto to ovs_vport_send
openvswitch: support MPLS push and pop for L3 packets
openvswitch: add processing of L3 packets
openvswitch: netlink: support L3 packets
openvswitch: add Ethernet push and pop actions
openvswitch: allow L3 netdev ports

 include/uapi/linux/openvswitch.h |  15 ++++
 net/openvswitch/actions.c        | 111 +++++++++++++++++-------
 net/openvswitch/datapath.c       |  13 +--
 net/openvswitch/flow.c           | 105 +++++++++++++++++------
 net/openvswitch/flow.h           |  22 +++++
 net/openvswitch/flow_netlink.c   | 179 ++++++++++++++++++++++++++-------------
 net/openvswitch/vport-netdev.c   |   9 +-
 net/openvswitch/vport.c          |  31 +++++--
 net/openvswitch/vport.h          |   2 +-
 9 files changed, 353 insertions(+), 134 deletions(-)

1.8.3.1