[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: TCP/IP noise simulator cont.



On Thu, 2 Aug 2001, Gilad Ben-Yossef wrote:

>
>
> Shlomi Fish wrote:
>
> > This letter addresses two issues regarding my TCP/IP noise simulator
> > project:
> >
> > 1. I set up a mailing-list to discuss it. To subscribe send an empty
> > message to ip-noise-subscribe@iglu.org.il .
> >
> > 2. I wish to know how I can "grab traffic using firewalling rules from
> > kernel mode out into user mode" and there decide what to do with the
> > packet (namely, let it go on, drop it or delay it). OmerM showed me an
> > example of how to do a very simple thing like that using a kernel module,
> > but I also like to know how to do it in a user-mod
>
> as someone already pointed out the best answer is QUEUE target of
> Iptables (or use netlink socket).
>

Yes, so I realized.

> BUT, are you sure that's what you want to do? sending packets back and
> forth from kernel space to luser space is very inefficient becuase of
> the context switches that must occur for this to happen. This is very
> unscalable.
>

I'm not saying it is going to be the final product, but it would be a
useful stepping stone. Naturally, I'll need to adapt it to also compile as
a kernel module sooner or later. But experiencing is best done at user
level.

BTW, I found perl bindings to IP-Queue and managed to write a simple noise
generator in Perl. I'm not going to keep it that way, but experiencing is
best done in perl than in C.

Regards,

	Shlomi Fish


> Gilad
>
>
>
> --
> Gilad Ben-Yossef <gilad@benyossef.com>
> http://benyossef.com :: +972(54)756701
> "Anything that can go wrong, will go wrong, while interrupts are disabled. "
> 	-- Murphey's law of kernel programing.
>



----------------------------------------------------------------------
Shlomi Fish        shlomif@t2.technion.ac.il
Home Page:         http://t2.technion.ac.il/~shlomif/
Home E-mail:       shlomif@techie.com

A more experienced programmer does not make less bugs. He just realizes
what went wrong more quickly.


=================================================================
To unsubscribe, send mail to linux-il-request@linux.org.il with
the word "unsubscribe" in the message body, e.g., run the command
echo unsubscribe | mail linux-il-request@linux.org.il