[ovs-dev] [PATCH 1/2] Improve dl_type checking in ofpact_check__

[Jesse Gross]

On Wed, May 1, 2013 at 1:11 AM, Simon Horman <horms at verge.net.au> wrote:
> Some actions require an MPLS dl_type while others require a non-MPLS
> dl_type. Enforce this for actions handled in ofpact_check__().
>
> Update the following actions to require an non-MPLS dl_type:
>
> set_ipv4_src
> set_ipv4_dst
> set_ipv4_dscp
> set_l4_src_port
> set_l4_dst_port
> dec_ttl
>
> Update the following actions to require an MPLS dl_type:
>
> set_mpls_ttl
> dec_mpls_ttl
> pop_mpls
>
> Update handling of the following actions to use the dl_type set by MPLS
> push and pop actions if it differs from the orginal dl_type. This allows
> their existing checks to encorce dl_type pre-requisites correctly.
>
>         output_reg
>         bundle
>         reg_move
>         stack_push
>         stack_pop
>         learn
>         multipath
>
> Signed-off-by: Simon Horman <horms at verge.net.au>

I think this is somewhat inconsistent with the handling of other
OpenFlow actions in the presence of wildcards. For example, a
completely wildcarded flow will allow a set TCP port action to succeed
while a set MPLS action will fail.

Personally, I'm in favor of stricter checking but that's not what has
been done historically. We do have those stricter checks for
extensions like the register actions and we could do the same for MPLS
although that seems like it would be very confusing.

Regardless, I think we could probably also assume that updating the
flow is the common case and do it once at the top of the loop rather
than for each action type.