[Openswan Users] l2tpd error when closing a connection- Peer tried to disconnect with invalid TID

[Paul Freeman]

Paul
I have done some testing on the xl2tpd 1.04 disconnection problem and
discovered the issue is in the comparison step (line 672) (which you already
knew).

If ((t->qtid != t->ourtid) && (t->ourtid > 0)) ...

It appears to me the assignment of t->qtid and t->ourtid somewhere else in
the code is incorrect or the comparison test itself is wrong as t->qtid <>
t->ourtid.

Not sure where else to look at this stage without reading through the code to
try and understand it better than I do at the moment (which is very
poorly:-)).

I am keen to help if at all possible so if you have suggestions you would
like me to test, please let me know.

Regards

Paul  

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SURREY HILLS, VICTORIA 3127 Email: Paul.Freeman at eml.com.au
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>-----Original Message-----
>From: Paul Wouters [mailto:paul at xelerance.com]
>Sent: Tuesday, October 24, 2006 1:46 AM
>To: Paul Freeman; Paul Wouters; Michael Richardson
>Cc: users at openswan.org
>Subject: Re: [Openswan Users] l2tpd error when closing a connection- Peer
>tried to disconnect with invalid TID
>
>On Mon, 23 Oct 2006, Paul Freeman wrote:
>
>> I am running openswan 2.4.6 and xl2tpd 1.0.4 (from Xelerance) on an IPCOP
>
>> Oct 23 12:04:53 firewall l2tpd[30017]: Connection established to
>> xxx.xxx.xxx.xxx, 1701.  Local: 56119, Remote: 6.  LNS session is
>'default'
>>
>> Oct 23 12:04:54 firewall l2tpd[30017]: Call established with
>xxx.xxx.xxx.xxx,
>> Local: 62656, Remote: 1, Serial: 0
>>
>> ...
>>
>> Oct 23 12:34:33 firewall l2tpd[30017]: control_finish: Peer tried to
>> disconnect with invalid TID (6 != 56119)
>>
>> ...
>>
>> Oct 23 12:34:59 firewall l2tpd[30017]: Maximum retries exceeded for
>tunnel
>> 56119.  Closing.
>>
>> Oct 23 12:34:59 firewall l2tpd[30017]: Connection 6 closed to
>> xxx.xxx.xxx.xxx, port 1701 (Timeout)
>>
>> Oct 23 12:35:04 firewall l2tpd[30017]: Unable to deliver closing message
>for
>> tunnel 56119. Destroying anyway.
>
>> Looking through previous posts on this topic by Jacco de Leeuw and others
>I
>> notice that the code in control.c in (x)l2tpd has been changed, swapping
>to
>> try and correct this.  However I still get the error.  Looking at the
>values
>> of the connection and tunnel ID's I notice that the connection and tunnel
>> ID's are switched around, hence the error message.
>
>I will have a look at this. Did switching the arguments make your log
>entries
>go away?
>
>> Should I be getting this error in my situation?
>
>The error shouldn't be there, but currently we do get the error and ignore
>it.
>
>> Is this a function of having xl2tpd listening on the internal IP address
>or
>> is there some other problem?
>
>No, that has nothing to do with it.
>
>Paul