Re: [lwip-users] Issue in handling out of sequence segments?

[Kieran Mansley]

On Tue, 2009-08-11 at 14:37 +0200, Kesten, Joerg wrote:
> Does anyone with further insight have some suggestion how this should
> be handled and/or if this really is a bug or just some
> misinterpretation by me?

Although I've just spotted another issue there that won't yet be handled
by my fix: by shrinking the new segment we should also be removing the
FIN flag from it (as it no longer contains the FIN sequence number).
This gets unpleasant as tcp_process() may already have done things based
on it having the FIN in it.  I think the best course of action would be
to say if an in-order received segment contains a FIN, we should bin the
out-of-order sequence queue at that time, because there can be no data
after the FIN and so logically anything that was out of order must have
now been correctly received.  That makes things a bit simpler.  The new
code that trims frames outside of the receive window will also need to
handle FINs better.  I'll re-work the patch for BUG27209

Kieran