Hi,

On Mon, Feb 27, 2023 at 10:19 AM Josef Miegl [off-list ref] wrote:

The Geneve encapsulation, as defined in RFC 8926, has a Protocol Type
field, which states the Ethertype of the payload appearing after the
Geneve header.

Commit 435fe1c0c1f7 ("net: geneve: support IPv4/IPv6 as inner protocol")
introduced a new IFLA_GENEVE_INNER_PROTO_INHERIT flag that allowed the
use of other Ethertypes than Ethernet. However, for a reason not known
to me, it imposed a restriction that prohibits receiving payloads other
than IPv4, IPv6 and Ethernet.

FWIW I added support for IPv4/IPv6 because these are the use cases I had
and could validate. I don't know what problems could arise from supporting
all possible ethertypes and can't test that.

This patch removes this restriction, making it possible to receive any
Ethertype as a payload, if the IFLA_GENEVE_INNER_PROTO_INHERIT flag is
set.

This seems like an addition not a bugfix so personally seems like it should
be targeting net-next (which is currently closed afaik).

Eyal.

This is especially useful if one wants to encapsulate MPLS, because with
this patch the control-plane traffic (IP, LLC) and the data-plane
traffic (MPLS) can be encapsulated without an Ethernet frame, making
lightweight overlay networks a possibility.

Changes in v2:
  - added a cover letter
  - lines no longer exceed 80 columns


Josef Miegl (1):
  net: geneve: accept every ethertype

 drivers/net/geneve.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

--
2.37.1