[Bro] &expire_func/&create_expire question

Christian Kreibich christian at whoop.org
Fri Nov 17 17:39:45 PST 2006

On Fri, 2006-11-17 at 16:43 -0800, Vern Paxson wrote:
> > Real time is out, since 1s hasn't yet passed. But network time has
> > advanced 91s before I see the callback!? 
> Timer expiration is driven off of packet arrivals.  Is there a lengthy
> lull in arriving packets that causes the 91 second delay?

Uh-oh. I've discovered that packets in that trace were not in
chronological order, sorry. So I switched to one that covers ~3 minutes,
definitely sorted and without substantial gaps, and now the delay is at
60s, when a burst of expirations is triggered.

I've uploaded the stdout output I get with that trace and the below code
at http://www.cl.cam.ac.uk/~cpk25/bro/expiration-log.txt.gz .

function expire(t: table[count] of count, idx:count): interval
        print fmt("Expiring %d at %s", idx, network_time());
        return 0 sec;

global state: table[count] of count &create_expire=1sec &expire_func=expire;
global idx: count = 0;

event new_packet(c: connection, p: pkt_hdr)
        state[idx] = idx;

        print fmt("%s", network_time());


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