Re: SCTP: Heartbeat ack recieved without sending Heartbeat

Hi Radhika,

see my comment in-line.

Best regards
Michael

On Jun 16, 2006, at 8:05 PM, radhika agarwal wrote:

> Hi,
>
> If an OOTB heartbeat ack is received, then it shall anyways lead to  
> sending of an abort chunk to the peer, as per section 8.4 of RFC 2960.
>
> If an heartbeat ack chunk is received from a destination addr of a  
> valid association, to which no heartbeat was sent, then the  
> heartbeat ack msg should be discarded.
>
> The processing of such a heartbeat ack message may lead to  
> incorrect calculations of association parameters like RTT
>
> Michael, as for peer sending an incorrect HB info , dont we assume  
> that the peer with which the 4 way handshake is successfully  
> executed is not an attacker. If not then we might have to include  
> another MAC with the HB info field.
If the peer sends wrong HB-ACKs he should not be able to affect other  
associations and not get better
throughput... What I saw is that implementations had an array index  
in the HB Info and we could modify it
such that it was not a valid index anymore. The stack crashed. This  
is what I mean: Check all stuff you get
before using it.
>
> Regards,
> Radhika
>
>
>
>
> Michael Tuexen <[email protected]> wrote:
> Comments in-line,
> Best regards
> Michael
>
> On Jun 16, 2006, at 12:18 PM, Brian F. G. Bidulock wrote:
>
> > ash,
> >
> > See also RFC 4460 Section 2.36.
> That section describes initial path verification. I think his question
> was more general: How do you process a received HB-ACK, when you
> have never sent a HB?
> The other point I made was: Even if you sent a HB, you can not be
> sure that the peer reflects the HB info. It could be an attacker...
> (we did this years ago at an interop and this provided some
> implementations
> problems...)
> >
> > --brian
> >
> > _______________________________________________
> > Sigtran mailing list
> > [email protected]
> > https://www1.ietf.org/mailman/listinfo/sigtran
> >
>
>
> _______________________________________________
> Sigtran mailing list
> [email protected]
> https://www1.ietf.org/mailman/listinfo/sigtran
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________________________
> Life is Beautiful.
> ______________________________________________________________
>
> Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and  
> 30+ countries) for 2¢/min or less.
> _______________________________________________
> Sigtran mailing list
> [email protected]
> https://www1.ietf.org/mailman/listinfo/sigtran