netdev-provider: Clarify comment where 'get_next_hop' function looks.

Some readers thought it was looking in an ofproto- or netdev-specific
table.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Flavio Leitner <fbl@redhat.com>
datapath: reorder action netlink attribute definition for upstreaming

Keeping the order of netlink attribute definition in the order of
upstreaming is the best way to keep all released user space program
forward compatible with upstreamed kernel modules.

Adjust action netlink attribute order to match with the current
upstreaming plan.

Recirc and hash actions are introduced in branch 2.3, which will be
fixed by the patch. The MPLS actions have been released since
branch-2.1 but there is no kernel implementation of them prior to
branch 2.3. Thus the ordering change should not affect them.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
userspace: add support for pop_eth and push_eth actions

These actions will allow L2->L3 and L3->L2 switching, and are supposed
to be added to flows installed in the datapath transparently by
ovs-vswitchd.

Signed-off-by: Lorand Jakab <lojakab@cisco.com>
userspace: add layer 3 flow and switching support

This commit relaxes the assumption that all packets have an Ethernet
header, and adds support for layer 3 flows.  For each packet received on
the Linux kernel datapath the l2 and l3 members of struct ofpbuf are
intialized appropriately, and some functions now expect this (notably
flow_extract()), in order to differentiate between layer 2 and layer 3
packets.  struct flow has now a new 'base_layer' member, because we
cannot assume that a flow has no Ethernet header when eth_src and
eth_dst are 0.  For layer 3 packets, the protocol type is still stored
in the eth_type member.

Switching L2->L3 and L3->L2 are both implemented by adding the pop_eth
and push_eth actions respectively when a transition is detected.  The
push_eth action puts 0s on both source and destination MACs.  These
addresses can be modified with mod_dl_dst and mod_dl_src actions.

Added new prerequisite MFP_ETHERNET for fields MFF_ETH_SRC, MFF_ETH_DST,
MFF_VLAN_TCI, MFF_DL_VLAN, MFF_VLAN_VID and MFF_DL_VLAN_PCP.

Signed-off-by: Lorand Jakab <lojakab@cisco.com>
datapath: add layer 3 flow/port support

Implementation of the pop_eth and push_eth actions in the kernel, and
layer 3 flow support.

Signed-off-by: Lorand Jakab <lojakab@cisco.com>