Actually, I have "Ethernet type II style frames", but if I disable my plugin, I can see that ETH dissector find a trailer, without having a length in type/length field. Moreover, I know that in my frames, the padding is added by the ethernet layer, so I should dissect the trailer at the ethernet level.

I saw ETH dissector uses a pseudo header with FCS length, but I can't reuse this value in my heuristic dissector (because not defined when heuristic dissector list is called) and I don't know how to do it without this value...

Thanks for your help

Yvan