net/mlx5: HWS, Disallow matcher IP version mixing

net/mlx5: HWS, Disallow matcher IP version mixing

Signal clearly to the user, via an error, that mixing IPv4 and IPv6
rules in the same matcher is not supported. Previously such cases
silently failed by adding a rule that did not work correctly.

Rules can specify an IP version by one of two fields: IP version or
ethertype. At matcher creation, store whether the template matches on
any of these two fields. If yes, inspect each rule for its corresponding
match value and store the IP version inside the matcher to guard against
inconsistencies with subsequent rules.

Furthermore, also check rules for internal consistency, i.e. verify that
the ethertype and IP version match values do not contradict each other.

The logic applies to inner and outer headers independently, to account
for tunneling.

Rules that do not match on IP addresses are not affected.

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/20250422092540.182091-4-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>