[ovs-dev] tunneling: new GRE vport option and action

[romain.lenglet at berabera.info]

Hi,

This series of 2 patches extends the GRE vport implementation to:
1) add an option to prevent matching received GRE packets on their
   remote (source) IP address;
2) add a vendor OpenFlow action to dynamically set the destination IP
   address of GRE packets in a flow.

The code in those patches is Copyright (C) 2010 Midokura, Inc. and
under the same licenses as the modified files.

We're using the new match_in_remote_ip option (patch 1/2) for instance
to use GRE with IP Multicast addresses as destination addresses.  In
this use case, OVS bridges on all hosts have one GRE port sending GRE
packets to the multicast IP address, and subscribe to that multicast
group to receive the GRE packets from all other hosts.  Disabling
matching on the source IP address is necessary to receive GRE packets
from more than one host.  In this case, GRE packets are matched on the
GRE key for each port.

We're using the new set_tunnel_nw_dst action (patch 2/2) to
dynamically set the destination IP address of GRE packets separately
for each flow.  This allows chosing the destination IP of tunnels
per-flow, instead of per-port.  This is much more scalable and
practical than using one GRE port per flow.  The only drawback is that
header caching has to be automatically disabled when that action is
applied to a packet.

Any chances to integrate those patches into the master branch? :)

Sincerely,
--
Romain Lenglet
Midokura, Inc.