Re: Tudor's Status Report - #9 of #17

[Fyodor <fyodor () nmap org>]

On Mon, Jul 4, 2016 at 3:52 PM, Tudor-Emil COMAN <
tudor_emil.coman () cti pub ro> wrote:

> Localhost scanning shows all ports marked as unknown.

Hi Tudor.  Good report.  Why do you think localhost scanning isn't
working?  It works with the poll and select engines, right?



> One big problem engine IOCP has is that it uses a lot of memory. Not only
> because one special structure needs to be made for each little
> read/write/connect that happens, for the read event, a read buffer 8192
> bytes in size(to mirror the one in do_actual_read) has to be allocated and
> kept for each read operation at one moment in time.

Is there any way to share the buffers or otherwise reduce the need to have
so many allocated at once?

>  Also I gave the engine a lower priority than poll so it should be called
> explicitly with the --nsock-engine=iocp parameter.
Why set it lower than poll?  I suspect that only a small fraction of 1% of
Nmap scans are going to use the nsock-engine parameter.  So if IOCP is
unequivocally better, it would be a much bigger win if we can make it the
default.  And if it's not better than poll/select, then we need to decide
whether it's still worth integrating.

> I also took a peek into those old registry tweaks.
Thanks, that's good info!

-Fyodor

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