[lwip-users] Re: [lwip] Memory leak and queued packets in etharp.c

[leon . woestenberg]

Hello Martin and others,

> address@hidden wrote:
> >
> >
> > Thanks for the bug report and the patch! I am currently code-auditing
the
> > etharp module as I had found another minor bug there.
> >
>
>Do you mention the bug #1603, ARP packet queue?
>I did see this problem also.

No, my _bug_ was #1493. #1603 is a feature request, to queue only
the latest packet submitted to be sent, as per RFC Host Requirements.

But indeed, that is what you are referring to below:

>As I wrote as a comment, I think that no packets
>should be dropped (at least not UDP). We'll need
>some kind of a chained queue (or simply an array)
>for the packets to be resent. Perhaps I'll do
>this within the next one or two weeks.
>
My proposal was to use the ->next pointer in combination
with the tot_len field.

See this chained list of 2 packets, consisting of
4 resp. 2 pbufs.

        #1 #2 #3 #4  #5  #6
tot_len 80 60 40 20 100 100
len     20 20 20 20  50  50

However, this would change the ways pbuf's are linked and
thus introduce changes for the complete stack, or at least
needs a code-audit to ensure that this use of the pbuf
structure does not affect current code.

In am interested to hear about how you would implement
queueing more than just 1 pbuf.

Regards,

Leon.

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