Re: New DLT_ value request

[Guy Harris <guy () alum mit edu>]

Will Barker wrote:
> Please may I request some additional libpcap DLT_ values? I need these to
> map onto the following wiretap values:
>
> 1.      WTAP_ENCAP_PPP_WITH_PHDR
> 2.      WTAP_ENCAP_CHDLC_WITH_PHDR
> 3.      WTAP_ENCAP_FRELAY_WITH_PHDR
> 4.      WTAP_ENCAP_LAPB

What is the format of the extra information you'll be putting at the 
beginning of the {PPP, Cisco HDLC, Frame Relay, LAPB} packets to hold 
the packet direction?  (Number of bytes, values to be put there, etc.)

> In addition is it acceptable to have one further value defined for our own
> proprietary encapsulation type?

By "proprietary" do you mean you'll be using this only internally within 
your company, with special internal versions of tcpdump/Wireshark/etc. 
or special internal-only Wireshark plugins, or do you mean you'll be, 
for example, submitting a dissector for that encapsulation for inclusion 
in Wireshark?

If the former, you could just use one of the DLT_USERn DLT_ values, and 
use one of the WTAP_ENCAP_USERn WTAP_ENCAP values, and not need an 
official DLT_ value.

If the latter, yes, you'd need to have a DLT_ value for that 
encapsulation type, and we'd provide one.

> Is there some formal request process for this?

The official process for asking for a DLT_ value is to, err, umm, send 
mail to tcpdump-workers () tcpdump org asking for the value. :-)

(I.e., this *is* the request process.)
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