Re: Perfmon total_alerts tracking bug

Mike Cox <[email protected]>
Newsgroups gmane.comp.security.ids.snort.devel
Message-ID <CANXgGS+8GJqE9LpBybirkC0OvAyKCBQKzmzQk6Kj8Br30hpqQA@mail.gmail.com>
And if it isn't obvious, the fix is to delete the following line from
src/preprocessors/perf-base.c in InitBaseStats():

sfBase->total_iAlerts = 0;

-Mike Cox


On Fri, Aug 21, 2015 at 10:21 AM, Mike Cox <[email protected]> wrote:

> Perfmon will output 'alerts_per_second' and 'total_alerts_per_second' with
> the latter including IP Reputation alerts and the former not.
>
> alerts_per_second is calculated for the time interval and so is
> total_alerts_per_second and previous counts are tracked with the *iAlerts
> variables so they aren't counted again. From src/preprocessors/perf-base.c
> in GetEventsPerSecond():
>
>     sfBaseStats->alerts_per_second =
>         (double)(pc.alert_pkts - sfBase->iAlerts) / Systimes->realtime;
>
>     sfBase->iAlerts = pc.alert_pkts;
>
>     sfBaseStats->total_alerts_per_second =
>         (double)(pc.total_alert_pkts - sfBase->total_iAlerts) /
> Systimes->realtime;
>
>     sfBase->total_iAlerts = pc.total_alert_pkts;
>
> However, total_iAlerts gets reset to 0 after each init; from
> src/preprocessors/perf-base.c in InitBaseStats():
>
> sfBase->total_iAlerts = 0;
>
> So effectively you get this:
>
>     sfBaseStats->total_alerts_per_second =
>         (double)(pc.total_alert_pkts - 0) / Systimes->realtime;
>
> Which I don't believe is what you want.
>
> I checked Snort 2.9.7.5 and Snort 2.9.8 beta and they both had this bug.
>
> -Mike Cox
>

------------------------------------------------------------------------------

_______________________________________________
Snort-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/snort-devel
Archive:
http://sourceforge.net/mailarchive/forum.php?forum_name=snort-devel

Please visit http://blog.snort.org for the latest news about Snort!
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.