Xdp bench redir map action drop

[dtatulea]

As requested by Jesper, added a egress mode for xdp-bench in redirect-map and redirect-multimap modes. This action can be forward (as before) or drop (new).

Haven't found any guidelines for contribution so please excuse me if I omitted something.

[tohojo]

A few nits, and as Jesper already pointed out on the kernel list, please update the man page as well.

I also have one reservation about the option: --egress-action will silently fail if --load-egress is not set. We should error out here instead, to avoid having silent errors that are hard to debug. Probably the easiest way to do this is to have a DEVMAP_EGRESS_NONE option in the enum that is not exposed as a visible option value, and checking that --load-egress was supplied if the option egress_action value is different from NONE...

[dtatulea]

Thanks for your review!

A few nits, and as Jesper already pointed out on the kernel list, please update the man page as well.

man page updated. LMK if you spot any issues.

I also have one reservation about the option: --egress-action will silently fail if --load-egress is not set. We should error out here instead, to avoid having silent errors that are hard to debug. Probably the easiest way to do this is to have a DEVMAP_EGRESS_NONE option in the enum that is not exposed as a visible option value, and checking that --load-egress was supplied if the option egress_action value is different from NONE...

Fixed using your suggestion. Couldn't think of a better way. For now NONE and FORWARD are equivalent after the initial check. LMK if this is confusing.

[tohojo]

Option handling looks good now!

But please don't edit the man page directly; edit the README.org file, then recompile the man page (should update on make, assuming you have Emacs installed).

Also, totally forgot the first time around: we'll need a selftest for this. Just a simple test to see that the new options work correctly should be fine; you can just copy and adjust one of the existing tests in test-xdp-bench.sh :)

[dtatulea]

Option handling looks good now!

Great!

But please don't edit the man page directly; edit the README.org file, then recompile the man page (should update on make, assuming you have Emacs installed).

Oh, didn't realize that the man page is generated. Will do.

Also, totally forgot the first time around: we'll need a selftest for this. Just a simple test to see that the new options work correctly should be fine; you can just copy and adjust one of the existing tests in test-xdp-bench.sh :)
Ack, will do.

[tohojo]

Looks good - thanks!