Re: [PATCH net-next 1/1] net_sched: Introduce skbmod action

On 16-07-18 01:38 PM, Cong Wang wrote:

On Mon, Jul 18, 2016 at 3:26 AM, Jamal Hadi Salim [off-list ref] wrote:

quoted

On 16-07-18 06:07 AM, Thomas Graf wrote:

quoted

Right. I was at the same point as Jamal and it is nasty to try and
reverse engineer the dumps without any further hints. I assume that's
what he is referring to with difficulties.

That +: if you get me a field which says "dstmac" i dont have to go
and start aggregating 32bit chunks to create a 48bit MAC (or worse
look at the offset and figure where they come from).

Been there, done that. I debugged u32 filter dumps too, I understand
your concern.

But this still looks like solvable to me, although it is definitely not easy,
probably even harder than the parsing logic. I will try to write some
code for iproute2 to see how far I can go.

I am sure that will be useful for someone - just not me.

Adding a new type of action/filter in kernel just for convenience seems
overkill. At very least I think we should just extend the existing ones,
for example, allowing pedit to accept and dump DST_MAC etc. Does this
sound good to you?

Not for me Cong - but i have no doubt it would improve pedit's
usability. Besides that is fixing one app (tc).
What i am trying to do is a common use case. It is an
optimization that has become necessary; your effort could be parallel
to this. Look at how much time we are spending arm chair lawyering this;
please go ahead and do that with iproute2 and let this patch go in. Like
I said this comes from deployment experience and need.

cheers,
jamal