Re: [lwip-users] TCP interface to HTTP client

[Kieran Mansley]

On Fri, 2007-07-13 at 11:52 +0200, Achuth Kamath wrote:
> Hi ,
> I have one doubt regarding the interface of LWIP TCP module to HTTP
> client.
> The case is where we have a HTTP client on top of LWIP stack, and are
> downloading a web page from HTTP server.
> In one special case, lwip_recvfrom() returns NULL., on enabling prints
> we see, 
> "lwip_recvfrom(4): buf == NULL!"
> I am not sure why it is returning NULL, looks like netconn_recv()
> returns NULL.
> 
> My question is, in this case, should the application close the TCP
> connection, calling lwip_close()? Or what best can the application do?
> Also, what might be the possible reasons for netconn_recv() to return
> NULL?

Usually means that the TCP connection has been closed and so there will
be no more data to recv, so calling lwip_close() is probably the right
thing to do if you want to close it in the other direction too.

Kieran