Re: [lwip-users] Usage of TCP_EVENT_RECV macro

[Roland Winistörfer]

Hello Leon

Thank you for your answer.
Do you have any idea why the callback is not installed ? I guess this is 
done automatically at every call of tcp_alloc() ?

BTW: This problem only occurs after the TCP connection is closed.

Regards, Roland


Leon Woestenberg wrote:

> Hello Roland, Lee,
>
> For any packet p, the macro first looks if the recv() callback is 
> non-NULL and passes the packet, otherwise drops (simply frees) the 
> given packet p.
>
> In this case, TCP_EVENT_RECV() is called with a NULL packet p to 
> indicate EOF to the callback function.
>
> **The real problem seems to be that the callback function is not 
> installed, i.e. pcb->recv == NULL**
>
> However, the macro should not try to free a NULL packet and shouldn't. 
> I will fix this in CVS.
>
> Regards, Leon.