Re: [lwip-users] lwip, mqtt and mbedtls

[Manu Abraham]

Hi Simon,

On Fri, Aug 21, 2020 at 2:31 AM goldsimon <goldsimon@gmx.de> wrote:
>
>
>
> Manu Abraham wrote:
> > [..]
> >  #error "lwip_sanity_check: WARNING: TCP_WND is larger than space
> >provided by PBUF_POOL_SIZE * (PBUF_POOL_BUFSIZE - protocol headers).
> >If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS
> >to 1 to disable this error."
> >
> >So, What should be done ?
> >
> >Am I going on the right track, or something is wrong somewhere ?
>
> I think so. TLS has this far only been used in setups with relatively large 
> RAM settings. It could be tweaked, but you'd have to know what you're doing. 
> The current compile time checks are there to help you to not get stuck in the 
> middle of a transfer because you're out of memory. That doesn't mean you 
> always need all memory...


Thanks for the direction.


So, I modified the POOL_SIZE


#define PBUF_POOL_SIZE          24            // (was originally 8)

now it freezes on altcp_mbedtls_connect()

 (931) altcp_mbedtls_connect:
tcp_connect to port 8883
(1181) tcp_conn


This is where it freezes:

err_t
tcp_connect(struct tcp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port,
            tcp_connected_fn connected)
{
  LWIP_DEBUGF(TCP_DEBUG, ("(%d) %s: Done\n", __LINE__, __FUNCTION__));
  return ret;
}

Any idea, why that would be the case ?


Thanks,
Manu