There is nothing technically wrong with dissectors being developed as
plugins. There might be some technical questions that arise from that
fact, if another dissector is using them, but for now, those issues
seemed to be dealt with correctly (for reference see the whole
openSAFETY vs. SercosIII mix-up)
My main motivation to move the Profinet and Ethercat dissectors out of
the plugin space comes from the fact, that the wireshark developers
encourage everyone to add new dissectors as built-in and not plugins.
If this is being done for all dissectors, the plugins should be moved
accordingly. That is just my way of thinking. Why make something
extra, if it is not needed or wanted anymore.
The reason against plugins might be, and I am just guessing here, that
everyone is talking about the same dissector if it is built-in. But
the plugin could be from a prior installation, or a different
wireshark version. I tried to figure out for some time, why my
dissector would not register underneath the SercosIII dissector, only
to find an old version of that specific plugin lying in my
~/.wireshark/plugins directory. That might be not the best reason in
the world, but for me it was a nasty mix-up, which cost me quite some
For all it's worth, I don't care anymore if the Profinet dissector
stays where it is, or not. I will send in a plug-in in the near
future, adding a heuristic dissection table, similair to SercosIII,
but besides that, I just thought of it as a good practice exercise for
myself moving the whole thing.
One more thing though, Ulf. Modbus/TCP was added with Rev. 3376, EIP
with 7851. Both are fieldbus protocols. Credits were credits due.