On Fri, Mar 30, 2001 at 02:34:34PM +0200, Hartmut Mueller wrote:
> I wrote three dissectors for the Building Automation and Control Network
> protocol.
Checked in.
Some cleanups I made:
I made the "next_tvb" variables local to the dissectors rather
than global (they're not used outside the dissectors);
I made the dissectors static (as they're not called outside the
file in which they're defined), and removed the header files
that declared them (as the header files are then not exporting
anything);
I got rid of the "CHECK_DISPLAY_AS_DATA()" calls (for any
dissector registered in a dissector table, or registered with
"register_dissector()" and called only through a handle, the
check is done in the code that handles dissector tables or
handles; the dissector doesn't have to do the check itself);
I moved the code to set "pinfo->current_proto", and to set the
Protocol and Info columns, before any field in the packet is
referred to (so that they're set before any exception is
thrown);
I changed a number of calls to "proto_tree_add_XXX()", for
various values of "XXX", to "proto_tree_add_item()" (if the
field value in a "proto_tree_add_XXX()" call isn't a variable
that's used elsewhere, or a value other than what's fetched from
the packet, you might as well use "proto_tree_add_item()" and
let "proto_tree_add_item()" fetch the value for you;
I passed -1, in some cases, as the "reported length" argument to
"tvb_new_subset()" - that lets "tvb_new_subset()" calculate the
reported length for you (which should be based on the reported
length of the frame, which may be greater than the amount of
data in the frame, if the capture was done with a snapshot
length less than the actual length of the frame).
> There are other data link layer protocols than BVLL to be implemented as
> dissectors because it is also possible to communicate over MS/TP (EIA-485),
> LonTalk (tm) and ARCNET. BACnet/IP was just a good starting point for me.
Hmm.
NetBSD, at least, supports ARCNET, and its libpcap and tcpdump support
ARCNET, I think; we may want to make Ethereal support it.
> I would be very happy about a Win32 version of Ethereal with BACnet included
> because I don't have any Win32 compiler around.
The next Ethereal release will include your BACNET code.
