On Sun, Oct 15, 2017 at 7:36 PM, Michael Mann via Wireshark-dev <[email protected]> wrote: > > > > -----Original Message----- > From: Richard Sharpe <[email protected]> > To: Developer support list for Wireshark <[email protected]> > Sent: Sat, Oct 14, 2017 1:47 pm > Subject: [Wireshark-dev] Reusing the code for various things in ieee802.11 > in other dissectors ... > >> Hi folks, >> >> I am almost finished a dissector for the IEEE1905 Multi-AP technical >> specification draft from August 2017. The work was done for an >> organization in the industry. It is pretty complete and has undergone >> testing with real traffic. >> >> Unfortunately, they make references to elements in IEEE802.11 2016. >> >> One specific item is 9.4.2.22.7 Beacon Reports from IEEE802.11 2016. >> There is another such reference as well. > > I'm not familiar enough with the protocols to know where exactly this is in > the dissector. I recently created a dissector table for tagged fields > ("wlan.tag.number"). I'm guessing this is where the beacon stuff is, so yes > existing dissector tables should handle this.
The problem with this is likely to be point 3 below because the structure as used by IEEE1905 is not tagged (although it does contain TLVs ...) >> >> These raise problems: >> >> 1. I don't want to duplicate code >> 2. The code in the current packet-ieee80211.c dissector is incomplete >> WRT the 2016 version of the spec. (Eg, it does not handle Vendor >> specific or Wide Bandwidth Channel Switch optional sub-elements.) > > I also created a few dissector tables in packet-ieee80211.c for vendor > specific extensions. Most of the cases involved multiple vendors that were > already in the dissector. I think a few more could probably be created. > Most of the ones I left only had OUI_WFA as the only vendor, so I lost > interest in the conversion to adding more dissector tables. > >> 3. The references in IEE1905 are to the underlying structures not the >> tagged structures. >> 4. The code in packet-ieee80211.c is declared static so I can't call >> it if I wanted to. > > Again, specifics about the code are more helpful to me. > >> >> We have mechanisms for dealing with this. One is dissector tables. >> Another is to declare certain functions non-static and put the >> definitions in header files. There might be others. >> >> Are there any suggestions? > > Without seeing the code, I would lean towards suggesting dissector tables as > the solution for most of it. Removing "static" from functions and declaring > them in header files should be more of a last resort. > You can put your patch up for review, even if it is just a WIP. Marking > where you don't want to duplicate code or where you want to call (currently > static) packet-ieee80211.c functions would be helpful. It will be coming as a patch soon ... :-) -- Regards, Richard Sharpe (何以解憂？唯有杜康。--曹操) ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <[email protected]> Archives: https://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://www.wireshark.org/mailman/options/wireshark-dev mailto:[email protected]?subject=unsubscribe
