Wireshark-dev: Re: [Wireshark-dev] 3GPP 23.038 encoding and string length

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Tue, 24 Dec 2013 11:44:41 -0800
On Dec 24, 2013, at 5:30 AM, mmann78@xxxxxxxxxxxx wrote:

> Isn't it simple enough to add a proto_tree_add_gsm_sms_item (or similar) API

We already have tvbuff and proto_tree_ routines that take bit offsets and bit counts, so this may be another case where the regular routines don't work; a routine to handle TS 23.038 encoding, taking a *bit* offset and a count of *characters*, might be the best solution here.

I'd vote for proto_tree_add_ts_23_038_item(), though - that encoding isn't used only in the GSM/3GPP/LTE version of SMS.

> and enforce the hf_ variables have ENC_3GPP_TS_23_038 encoding?

I'm not sure what you mean by "enforce the hf_ variables have ENC_3GPP_TS_23_038 encoding"; named fields don't have an encoding, so you can't enforce that a named field (which is what an hf_ variable refers to) have a particular encoding.

> I don't think the meaning of the length field of proto_tree_add_item should be different based on encoding,

It shouldn't be based on the encoding.