Re: [lwip-users] lwip recv callback questions

[Mike He]

Thanks Sergio,

1. Can you point me to a description of how to use the different error 
codes, then?

3. I just located the httpserver_raw in vendor's lwip package. It also 
doesn't call tcp_accepted. Perhaps the problem is that my vendor is 
using an outdated version, 1.3.2?




On 5/30/2014 10:47 AM, Sergio R. Caprile wrote:
> Hi, following is MY opinion (and experience)
>
> 1: Since the callback function is called by the stack as I instructed, I
> wouldn´t answer with ERR_ARG, since arg is just as I instructed the
> stack to call me... so, if you still do it because you don't trust the
> stack, then don't rely on it to stop calling you the wrong way... goto 3;
> 2: Once you tcp_recvd() those bytes and answer ERR_OK, you are the owner
> of the pbuf, you can free it when you want. Remember that that memory
> won't be available to hold new packets until you release it.
> 3: Vendors do what they think will sell more. I wouldn't use their
> examples as a learning tool for lwIP. Instead, check the available
> examples in the contrib tree: SMTP for a client, netio/httpserver_raw
> for a server
>
> Regards