Re: [lwip-users] new data callback with pbuf pointer of zero

[Kieran Mansley]

On 22 Nov 2009, at 18:07, JM wrote:

> I'm a bit confused by this one.  It took me a while to track down the cause 
> of my crashes, but I finally discovered that the callback specified by 
> tcp_recv was being passed a a pointer of zero for the pbuf.  The callback 
> function never checked for this and cause the processor to throw an exception 
> because of the invalid pbuf pointer.  Anyway, I have the callback return if 
> the passed pbuf is zero and now it's fine.  The passed error code is zero.  
> 
> What would cause it to be passed zero for the pbuf?  By definition, isn't 
> this callback used when there is data to provide?  I'm using 1.3.0 in raw 
> mode.

Probably the other end has closed the connection.  i.e it signifies no more 
data will be received.

Kieran