Wireshark-dev: [Wireshark-dev] Re : Ethernet trailer

Date: Wed, 6 May 2009 06:53:18 +0000 (GMT)
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


De : Richard Brodie <leogah@xxxxxxxxxxx>
À : wireshark-dev@xxxxxxxxxxxxx
Envoyé le : Mercredi, 6 Mai 2009, 1h08mn 41s
Objet : Re: [Wireshark-dev] Ethernet trailer

> Moreover, I don't understand how ethernet dissector can find if there
is padding or not.

You can only do this with '802.3' style frames where the type/length
field contains a length.
In the typical case, where the type/length field identifies a type, it's
all passed up to the next
layer which will have to work it out for itself.

Richard Brodie..
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