[ovs-dev] [PATCH net-next 2/2] openvswitch: netlink attributes for IPv6 tunneling

[Jesse Gross]

On Wed, Sep 30, 2015 at 12:28 AM, Jiri Benc <jbenc at redhat.com> wrote:
> On Tue, 29 Sep 2015 20:05:00 -0700, Jesse Gross wrote:
>> This appears to me to be a bug in the existing code.
>> ovs_tunnel_get_egress_info() as a general mechanism is still in use
>> and should work with both the old and new configuration methods.
>
> It's currently used only from the compat layer (the API that the user
> space that is unaware of lwtunnels use).

Yes but that is a bug. From the perspective of the intended use of
this function, I don't think there is any difference between compat
and non-compat users.

> I don't understand what it would be good for with lwtunnel based
> tunnels. The metadata_dst is created in the validate_and_copy_set_tun
> function (net/openvswitch/flow_netlink.c) and used to specify egress
> encapsulation metadata. The ovs_tunnel_get_egress_info function is not
> needed.

This function is used to report back information that is the result of
the encapsulation process, such as the UDP source port chosen. Take a
look at net/openvswitch/actions.c:output_userspace(), particularly the
OVS_USERSPACE_ATTR_EGRESS_TUN_PORT case.