net/mlx5: HWS, Harden IP version definer checks

[ Upstream commit 6991a975 ]

Replicate some sanity checks that firmware does, since hardware steering
does not go through firmware.

When creating a definer, disallow matching on IP addresses without also
matching on IP version. The latter can be satisfied by matching either
on the version field in the IP header, or on the ethertype field.

Also refuse to match IPv4 IHL alongside IPv6.

Signed-off-by: Vlad Dogaru <vdogaru@nvidia.com>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://patch.msgid.link/20250422092540.182091-3-mbloch@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>