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

[address@hidden]

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.
Excerpt from doc/rawapi.txt
The callback function will be passed a NULL pbuf to indicate that the 
remote host has closed the connection.

Does that make it clear enough? :-)

Simon