Wireshark · Ethereal-dev: [Ethereal-dev] Re: ASN.1/RTSE/ROS/X.411

[ronnie sahlberg <ronniesahlberg@xxxxxxxxx>]

On 7/11/05, Graeme Lunt <graeme.lunt@xxxxxxxxx> wrote:
> Ronnie,
> 
> > Please see the CMIP (which uses ROS)  FTAM and MMS  which are all
> > implemented ontop of ACSE and which shows how some data is passed from
> > the PRES layer to the dissector using the SESSION structure.
> > 
> > Since this structure is already used for these things, this is i think
> > where you would add your extra variable.
> 
> Thanks - I'll have a look at this and see how this works.
> 

Oh, look in the template as well for CMIP.
There is an example of how the switch  there decides what kind of PDU
to dissect, if it is an ASSOCIATE, ABORT or DATA_TRANSFER PDU,
passed up from the SES layer and filled in in the PRES layer.

This is how CMIP known which of the three PDU types it should dissect.


Another think to note which i dont think we have documented yet in the
wiki is that ASN2ETH does not yet handle tagged assignment properly
yet,
assignments of the form

Foo ::= [APPLICATION X] IMPLICIT Bar


See FTAM and the conformance file how to work around this if you need to.
(add FN_BODY to the conformance file to explicitely eat the TAG/LENGTH
and pass on the implicit_tag field.