Re: [lwip-users] udp

[Marc Boucher]

On Sun, Mar 16, 2003 at 09:59:48AM -0500, David Haas wrote:
> Hi Leon,
> 
> The problem is that the pbuf which the reference count is incremented in 
> is a ROM type pbuf. The actual data buffer was passed in using the 
> sendto() function call and freeing the pbuf which is pointing to it will 
> not free the original data buffer. So although the ARP queue does 
> increment the reference count and does properly free the pbuf 
> afterwards, this particular pbuf is of type ROM and actually only points 
> to the data buffer. Nothing is done to free the original data buffer and 
> no signal is received by the application to know when it can free the 
> data buffer.
> 
> I cannot beleive that anyone is using UDP with the sockets interface and 
> not running into this problem (unless I really missed something here).
> 
> David.

We have been successfully using UDP sockets for WAP and DNS without
ARP over non-ethernet interfaces (PPP and GPRS).

Marc