From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guy Harris Subject: Assigning a new DLT_ value for "standardized" radiotap? Date: Tue, 16 Feb 2010 18:08:15 -0800 Message-ID: <5F21AFA5-4D4C-49A0-A228-A1177630E366@alum.mit.edu> Mime-Version: 1.0 (Apple Message framework v1078) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Return-path: Sender: radiotap-owner-sUITvd46vNxg9hUCZPvPmw@public.gmane.org To: radiotap-sUITvd46vNxg9hUCZPvPmw@public.gmane.org List-Id: radiotap@radiotap.org The presence-bit-number collisions mentioned on the radiotap Web site = appear to be due to OpenBSD doing its own thing: 14: FCS in OpenBSD, RX Flags in the standard and assigned for = that in NetBSD and Linux 15: hardware queue in OpenBSD, proposed for TX flags in the = standard and assigned for that in NetBSD and Linux 16: RSSI in OpenBSD, proposed for RTS Retries in the standard = and assigned for that in NetBSD and Linux (There was also a brief period of time, between 2007-06-11 and = 2007-07-01, where FreeBSD used 14 for the extended channel information, = but it got moved to 18; it appears that was done before FreeBSD 7.0 got = released, so it doesn't appear that any *released* version used 14 for = the extended channel information.) I've filed an bug against this: = http://cvs.openbsd.org/cgi-bin/query-pr-wrapper?full=3Dyes&numbers=3D5691 but nothing has been done for it; I've also asked Reyk Floeter about it, = and heard nothing. I forget whether I've asked Damien Bergamini about = it or not. Unfortunately, there are probably both OpenBSD and NetBSD/Linux captures = out there with a network type value of 127, so we can't easily make = tcpdump or Wireshark or... handle both automatically (a command-line = flag for tcpdump and a preference for Wireshark could be used). If we = were to introduce a new DLT_ value for "standard radiotap", tcpdump and = Wireshark could unconditionally interpret those presence bit values as = having the NetBSD/Linux meaning, and use a flag/preference or whatever = for the existing value (or just blow off OpenBSD). Would that be useful?=