[matthew.bradley@xxxxxxxxxxxxx]

No replies to my post - would it be possible to check in the attached patch?

I plan to add additional functionality to the COTP dissector. Does anyone
have any items for a wish list?

Matthew
> -----Original Message-----
> From: CNS - Matthew Bradley 
> Sent: 14 May 2004 21:32
> To: Ethereal Dev (E-mail)
> Subject: COTP TSAP fields
> 
> 
> Please find attached a patch for packet-clnp.c. It adds 
> fields for source and destination TSAP for COTP.
> 
> 1. As COTP does not define the format of TSAPs, the current 
> Ethereal implementation looks at whether the data contains 
> printable ASCII bytes and either outputs a string or a byte 
> representation. In my environment (ICL OSLAN), TSAPs are 
> always bytes, e.g. 0x5610 and I wanted an elegant way of 
> constructing filters to allow me to express such TSAPs in 
> filters as bytes. At the same time, many COTP implementations 
> will use printable strings. So I came up with the following 
> implementation:
> 
> * There are four new fields: 
> cotp.src-tsap,cotp.src-tsap-bytes,cotp.dst-tsap,cotp.dst-tsap-
> bytes. Using source TSAPs as the example, if the dissector 
> encounters a source TSAP variable parameter it will add both 
> a cotp.src-tsap and a cotp.src-tsap-btyes to the tree. One, 
> however, will always be hidden.
> 
> * I have added a new preference option to the dissector, 
> tsap_display that has three settings: auto, string or bytes. 
> If the option is set to default, then the choice of which 
> field to make hidden will be determined by the "is it ASCII 
> and printable" routine. If 'string', then it will always be 
> the cotp.src-tsap-bytes and cotp.dst-tsap-bytes that hidden; 
> if 'bytes' then it will always be cotp.src-tsap and 
> cotp.dst-tsap bytes that are hidden. The default is 'auto'.
> 
> Is this solution OK? Are there any better ways of achieving 
> the same end?
> 
> 2. As stated above, I only have two byte TSAP fields to test 
> with. I would appreciate if someone could test the patch with 
> some printable string TSAP COTP, or mail me a capture to test with.
> 
> The patch was written and tested against 0.10.3. 
> 
> All feedback and criticism welcome.
> 
> Matthew
> 



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