Re: [nmap-svn] r28292 - in nmap: . nsock/src

[Fyodor <fyodor () insecure org>]

On Fri, Mar 16, 2012 at 01:02:57PM -0700, commit-mailer () insecure org wrote:
> Log:
> Update nsock_tod before creating a timer.
>
> nsock_tod is Nsock's idea of the current time. It is updated when an
> nsock_pool is initialized, on each iteration of nsock_loop, and in a few
> other places. What could go wrong, with respect to timers, is a sequence
> like this:
>       nsp_new
>       [... some long delay ...]
>       nsock_create_timer(timeout)
>       nsock_loop
> The time elapsed after the creatino of the timer until it fires would
> not be timeout, but rather timeout - delay. If the delay was long
> enough, the timer would fire as loop as nsock_loop was entered.
>
> This showed itself in IPv6 OS detection. We schedule 6 timers
> immediately, 100 ms apart. If the pcap_open or anything else took too
> long, then the timers would fire all at once. This messed up the
> calculation of the TCP_ISR feature.
>
> Perhaps we should do this when any new event is created? It is already
> done manually at the beginning of each of the connect functions.

Adding this to event creation sounds good to me.

Cheers,
-F
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