2009/7/23 Nestor Tarin Burriel <nestabur@gmail.com>

Hi again Greg,

I've tried your suggestion and it seems like the facts that is the rule checking are the same.

This is my last try:

rule "SnortRuleRetract"

    dialect "mvel"
    when
        $s1 : Snort( sig_name != "(portscan) Open Port")
        $s2 : Snort ( sig_name != "(portscan) Open Port" , id != $s1.id)
    then
        retract($s2);
        System.out.println(" ********* Deleting from WM");
end

And is never fired ...

There are no more rules in the package, this is the only one ... so I don't understand anything ... could be the error in the engine? I dont retract any fact ... as you can see in my code ...

NEStor

2009/7/23 Nestor Tarin Burriel <nestabur@gmail.com>

Yes, that is the purpose ;)

I will try ;)

Thanks 4 your help

2009/7/22 Greg Barton <greg_barton@yahoo.com>

Ah, overlooked that second rule. Have you tried the overlap operator?

So, just to clarify, the purpose of the two rules should be:

SnortRule: If two Snort events that are not port scans of an open port on the same destination arrive more than 5 minutes apart, delete the earlier one.

SnortRuleRetract: If two Snort events that are not port scans of an open port on any two destinations arrive within 5 minutes of each other, delete the earlier one.

Have you tried removing the temporal operators completely, just for testing purposes? What happens? i.e.

"TimelessSnortRule"

$s1 : Snort( sig_name != "(portscan) Open Port") from entry-point "Correlator"

$s2 : Snort( sig_name != "(portscan) Open Port" , id != $s1.id, ip_dst == $s1.ip_dst) from entry-point "Correlator"

"TimelessSnortRuleRetract"

$s1 : Snort( sig_name != "(portscan) Open Port") from entry-point "Correlator"

$s2 : Snort ( sig_name != "(portscan) Open Port" , id != $s1.id) from entry-point "Correlator"

--- On Wed, 7/22/09, Nestor Tarin Burriel <nestabur@gmail.com> wrote:

> From: Nestor Tarin Burriel <nestabur@gmail.com>
> Subject: Re: [rules-users] CEP Rule Help Needed
> To: "Rules Users List" <rules-users@lists.jboss.org>
> Date: Wednesday, July 22, 2009, 1:47 PM

> Thanks Greg,
>
> As you can see in the code I sent, I have the 2
> implementations:
>
> "SnortRule"
>
>         $s1 : Snort( sig_name !=
> "(portscan) Open Port") from entry-point
> "Correlator"
>
>         $s2 : Snort( sig_name != "(portscan)
> Open Port" , id != $s1.id, ip_dst == $s1.ip_dst, this
> after [5m] $s1) from entry-point "Correlator"
>
>
> "SnortRuleRetract"
>         $s1 : Snort( sig_name !=
> "(portscan) Open Port") from entry-point
> "Correlator"
>         $s2 : Snort ( sig_name != "(portscan)
> Open Port" , id != $s1.id, this after [0m,5m] $s1) from
> entry-point "Correlator"
>
>
> and any of them are thrown
>
> ...
>
> 2009/7/22 Greg Barton <greg_barton@yahoo.com>
>
>
>
> Maybe this is a problem of language. Here's what you
> say the rule should do:
>
>
>
> 'After receiving a fact "MyModel" wich name
> != "aaa", if arrives another
>
> with same ip and different id after a
> period between 0 and 5 minutes the
>
> rule have to retract the last one and keep the first
> fact (the older one)'
>
>
>
> Which I would interpret as "Event 1 comes in, then
> event 2 comes in between 0 and 5 minutes later." Does
> that sound right?
>
>
>
> And here's the rule that you think fits the
> requirements:
>
>
>
> rule "SnortRule"
>
>    salience 2
>
>    dialect "mvel"
>
>    when
>
>    $s1 : Snort( sig_name != "(portscan) Open
> Port") from entry-point "Correlator"
>
>    $s2 : Snort( sig_name != "(portscan) Open
> Port" , id != $s1.id, ip_dst == $s1.ip_dst, this
> after [5m] $s1) from entry-point "Correlator"
>
>    then
>
>    System.out.println("******************
> Snort Alert!!!!" + $s1.getData());
>
>    retract($s1);
>
> end
>
>
>
> Check out the docs, though:
>
>
>
> https://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/trunk/target/docs/drools-fusion/html_single/index.html#d0e622
>
>
>
>
> The after operator in this case would check that (5m <=
> $s2.startTimestamp - $s1.endTimeStamp <= +infinity).
>
>
>
> So the rule actually implements "Event 1 comes in,
> then event 2 happens at leat 5 minutes later."
>
>
>
> If you use the second argument of after I think it would
> work:
>
>
>
> $s2 : Snort( sig_name != "(portscan) Open Port" ,
> id != $s1.id, ip_dst == $s1.ip_dst, this
> after [0m,5m] $s1) from entry-point "Correlator"
>
>
>
> According to the docs this should check that (0m <=
> $s2.startTimestamp - $s1.endTimeStamp <= 5m).
>
>
>
> You could alternately use "overlaps". Place an
> @duration(5m) annotation on the Snort declaration and try
> this condition:
>
>
>
> $s2 : Snort( sig_name != "(portscan) Open Port" ,
> id != $s1.id, ip_dst == $s1.ip_dst, this
> overlaps $s1) from entry-point "Correlator"
>
>
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
>
> rules-users mailing list
>
> rules-users@lists.jboss.org
>
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
>

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--
Regards,
PriyaKathan