Ethereal-dev: Re: [ethereal-dev] TCP stream, UDP fragmentation

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From: Guy Harris <gharris@xxxxxxxxxxxx>
Date: Sun, 21 Nov 1999 23:56:31 -0800
> An important feature would be to provide somehow the dissectors with the 
> concatenated data from multiple packets.

Yes!

> An incarnation of the same problem are fragmented UDP packets.

Yes!

> Modern NFS servers support 32K read/write size, so we get (over Ethernet)
> 23 UDP fragments (1472 UDP bytes) and only the first has the UDP/RPC/NFS
> header.

Even boring old 8K reads/writes have this problem over most network -
and READDIR replies are even worse.

This is what got me interested in packet analyzer programs in the first
place - "snoop" couldn't decode past the first fragment of a READDIR
reply (and Microsoft Network Monitor couldn't decode past the first TCP
segment of a FindFirst/FindNext reply, which is the equivalent problem
for SMB), and I had to do it by hand.  (The underlying problem was
probably a file system problem I discovered when looking at a separate
non-networking crash, so perhaps a better tool wouldn't have helped,
but....)

I've wanted better capabilities for quite a while, and have been
thinking about how to do it for a while - unfortunately, I don't have a
definite idea on how to do it, but I'll try to put together my current
ideas soon (where "soon" may not be until some time next week).