David Young said: > > I propose to change the DLT_PRISM_HEADER semantics. I am trying to > identify the stakeholders in such a change, to find out what they think. > I figure some of them read this list. > > For DLT_PRISM_HEADER, libpcap expects a header that is a whopping 144 > bytes long. It does not resemble any header a Prism radio will give, so > the name DLT_PRISM_HEADER for it is misleading. > > Examining linux-wlan-ng and ethereal, the header actually consists of > length-type-value (LTV) tuples for received signal strength, PHY type, > and other radio parameters. This seems like a stab at a generic 802.11 > radio header. Why, then, is it not called DLT_IEEE802_11_RADIO, for > example? The former name is misleading. > > I ask because I am adding to NetBSD a DLT whose header contains the > portions of the Prism header preceding the IEEE802.11 header. I have > tentatively called it DLT_SHORT_PRISM_HEADER, to avoid clashing with > DLT_PRISM_HEADER, but I prefer to rename the old DLT_PRISM_HEADER > to DLT_IEEE802_11_RADIO, and to call the Prism-specific header > DLT_PRISM_HEADER. > > Your thoughts? > > Dave > > -- > David Young OJC Technologies > [EMAIL PROTECTED] Engineering from the Right Brain
As I remember, there's more to it than that; DLT_PRISM_HEADER was originally a short header with just the Prism stuff, but it's now both that *and* the new TLV header, pending support in Linux for a new ARPHRD_ type for the new TLV header (and support in libpcap for a new DLT_ value for the new TLV header). As long as the DLT_PRISM_HEADER header begins with a value other than 0x80211001 (or other 0x80211XXX values), Ethereal will interpret the packet as having the old Prism header. - This is the TCPDUMP workers list. It is archived at http://www.tcpdump.org/lists/workers/index.html To unsubscribe use mailto:[EMAIL PROTECTED]?body=unsubscribe
