Wireshark-dev: Re: [Wireshark-dev] Does lua provide something like range strings?
From: Peter Wu <[email protected]>
Date: Wed, 10 Oct 2018 18:29:52 +0200
On Tue, Oct 09, 2018 at 11:38:29AM -0700, Richard Sharpe wrote:
> On Tue, Oct 9, 2018 at 7:14 AM Peter Wu <[email protected]> wrote:
> >
> > Hi Richard,
> >
> > On Mon, Oct 08, 2018 at 10:59:35AM -0700, Richard Sharpe wrote:
> > > I am wondering if the Lua interp in Wireshark provides the equivalent
> > > of range strings?
> > >
> > > Does anyone know?
> > >
> > > I guess I could make the indexes strings, since they are associative
> > > arrays anyway but looking up a value in a range would be difficult.
> >
> > There does not seem to be support for range strings, but it could be
> > added. See value_string_from_table in epan/wslua/wslua_proto_field.c for
> > an example.
> >
> > I suppose that the natural syntax would be:
> >
> >     local your_range_string = {
> >         { 0, 24, "First quarter" },
> >         { 25, 54, "Second quarter" },
> >     };
> 
> Hmmm, I think it might need more than that:
> 
> #define WSLUA_OPTARG_ProtoField_new_VALUESTRING 4 /* A table
> containing the text that
>         corresponds to the values, or a table containing unit name for
> the values if base is
>         `base.UNIT_STRING`, or one of `frametype.NONE`,
> `frametype.REQUEST`, `frametype.RESPONSE`,
>         `frametype.ACK` or `frametype.DUP_ACK` if field type is
> ftypes.FRAMENUM. */
> 
> The code handling a new ProtoField assumes that arg 4 is a ValueString
> ... there would have to be some way to indicate that it is a range
> string.
> 
> The BASE field is field 5. We could have symbols ORed into that, I guess.

Right, the current documentation already contains a case for
base.UNIT_STRING, you would have to add an additional base.RANGE_STRING.

Will you be working on this feature?
-- 
Kind regards,
Peter Wu
https://lekensteyn.nl