Re: [PKT_SCHED]: Allow using nfmark as key in U32 classifier.

[Thomas Graf <tgraf@suug.ch>]

* jamal <1104277165.1100.291.camel@jzny.localdomain> 2004-12-28 18:39
> On Tue, 2004-12-28 at 18:19, Thomas Graf wrote:
> > Why? I don't get that. Generic matches must only be considered if all
> > keys of u32 match. u32 keys are just ANDed matches if one fails we can
> > directly declare the classifier as unmatched. 
> 
> yes - and that still applies here but you can now interleaf - as i
> mentioned earlier:
> 
> match u32 ..
> ematch string "Thomas" ...
> match u32 ...
> ematch meta tcindex ..

Yes but the only avantage of this is that a u32 match can be
made dependant on a ematch. Is this really worth special
handling? It requires special handling not needed for any
of the other classifiers.

I understand your point but don't agree at the moment. I
might change my mind tomorrow ;->

> I dont wanna go into details of whether we could actually make the new
> keys do more than just strict AND from left to right - but you can see
> the potential to "fix" this if we are defining a new key ;->

We should rather do it on cls_api level, unfortunantely it's not that
simple but the current status of having one classifier kind per prio and
no way to interconnect them must be changed somewhen. 

> Ok, the logical expressions are the tricky part. But refer to what i am
> saying above. You still need to be backward compatible. But for the new
> keys you could go onto the adventorous side. I havent given the logical
> expressions much thought but i will in the background

Implementing logical expressions directly into u32 would be bad but
we could have u32 hold a expression tree rather than the ematch
directly which means you could do

match u32 ..
(ematch meta nfmark .. or string "...")
match u32 ..