tcpdump mailing list archives
Re: Linktype needed
From: "Guy Harris" <guy () alum mit edu>
Date: Sat, 5 Jun 2004 11:56:20 -0700 (PDT)
Martin Angler said:
my name is Martin Angler and I am developing a BACnet MS/TP - enabled
netdevice-driver
under GNU/Debian Linux. Now I've seen, that there is no linktype that
specifies BACnet
MS/TP. So I wanted to ask whether you could define/implement a
corresponding linktype. I infer from some stuff I've seen that BACnet MS/TP is a link-layer protocol atop which the higher-level BACnet protocols can run (just as they can run atop UDP and 802.2). Will your driver supply "raw" packets with a header specified by the BACnet specification (the ISO standard appears to cost over 350 CHF, so I haven't bought it), or will it supply some form of "cooked" software that might not be what other BACnet MS/TP capture mechanisms might supply? If the former, the linktype should probably be called DLT_BACNET_MS_TP or something such as that; if the latter, the name should probably have something in it to indicate what type of header it is (see, for example, DLT_ARCNET, which should perhaps have been DLT_ARCNET_BSD, and DLT_ARCNET_LINUX, or DLT_APPLE_IP_OVER_IEEE1394, which is not raw Firewire but has a synthetic header).
Other people that worked on an MS/TP dissector (www.abmlinux.de) already
tried to
contact you, but without success.
I don't think I've seen that on tcpdump-workers. Do they have their own driver and, if so, does it supply the same link-layer header (if not, it'd need a separate DLT_ value)? - This is the tcpdump-workers list. Visit https://lists.sandelman.ca/ to unsubscribe.
Current thread:
- Linktype needed Martin Angler (Jun 05)
- <Possible follow-ups>
- Re: Linktype needed Guy Harris (Jun 05)
- Re: Linktype needed Martin Angler (Jun 07)
- Re: Linktype needed Guy Harris (Jun 07)