Netmap and in-kernel IPFW interactions!

[h bagade]

On Sat, Oct 19, 2013 at 6:58 PM, Raimundo Santos <raitech at gmail.com> wrote:

> On 19 October 2013 06:00, h bagade <bagadeh at gmail.com> wrote:
>
> > Hi Everybody,
> >
> >
> Hello!
>
>
> > I have compiled my kernel with support of netmap without any changes on
> > ipfw. Afterwards, I defined ipfw rules and surprisingly they worked!!
> >
> >
> Being netmap-ed your kernel doesn't mean you are really using it. If your
> data continue to take normal paths, ie, do not touch netmap, it will be
> there to the in kernel classifier take care.
>
>
> > Before my experiment on ipfw, I'd thought because packets are reached to
> > userspace directly by means of netmap, so in-kernel ipfw won't be able to
> > check them in between?!
> >
> >
> You must open the netmap device and interact with it, no more, no less. As
> the OPERATION section of netmap(4) states:
>
> netmap clients must first open the open("/dev/netmap")
>
> If your NIC driver doesn't support netmap, you end up with the normal path
> to frames and packets.
>
>
> > Could anyone clarify me how in-kernel tools are able to work even after
> > netmap is used?
> >
>
> So, to clarify you, you must clarify us: how are you *using* it, actually?
>
> Best Regards,
> Raimundo Santos
> _______________________________________________
> freebsd-net at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>

I've changed em and igb drivers too. In this situation, I think that they
are using netmap and grow-up performance is a sign of the change.  I've
used pkt-gen for performance checking.