Re: [lwip-users] icmp6

[delamer]

Hi Amena,

I don't remember the exact details for the copy, but it may have been 
related to:

- the input/output pbufs are sometimes allocated from different sources
- it's possible the output pbuf needs to be buffered (e.g. if neighbor 
discovery is required before the response)
- I believe there could be different IPv6 option headers in req and resp 
and bring alignment issues

I know I tested no-copy at the time it was developed and run into some 
problem. Hope this gives you a hint if you're investigating.

Regards,
Ivan


On 2018-08-14 10:00, address@hidden wrote:
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> Today's Topics:
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>    1. icmp6 (Amena El Homsi)
>    2. Re: icmp6 (address@hidden)
>    3. Re: LwIP RAW + Zynq - Unresponsive Tx path when Rx is active
>       (Nenad Pekez)
>    4. Re: icmp6 (Amena El Homsi)
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> ----------------------------------------------------------------------
>
> Date: Tue, 14 Aug 2018 15:49:57 +0300
> From: Amena El Homsi <address@hidden>
> To: Mailing list for lwIP users <address@hidden>
> Subject: [lwip-users] icmp6
> Message-ID:
>         <address@hidden>
> Content-Type: text/plain; charset="utf-8"
>
> Hi,
>
> When we receive an echo request using IPv6, LwIP copies the request to 
> new
> pbuf to send the reply.
> Why LwIP doesn't use the echo request pbuf, instead of allocating a new 
> one
> (as what LwIP does when replying to IPv4 echo requests)?
>
> Thanks in advance.
>
> --
>
> Amena El-Homsi
> Computer & Communication Engineer
> Dipl. Eng,  M.S.