[lwip-users] R: Problem accessing "httpd" web server from a Linux PC

[Bettega Stefano]

If I well remember the httpd examples uses RAW APIs (it's in httpserver_raw 
folder) and it's intended to be used when NO_SYS=1, as it accesses directly the 
internals structures of lwIP. As you are using FreeRTOS, you may have 
unpredictable results. I had the same problem and had to switch to httpserver, 
which uses netconn APIs.

Cheers,
Stefano

-----Messaggio originale-----
Da: address@hidden [mailto:address@hidden Per conto di Info
Inviato: giovedì 3 dicembre 2015 14:34
A: address@hidden
Oggetto: [lwip-users] Problem accessing "httpd" web server from a Linux PC

Hi

I'm using the "httpd" (httpd.c) web server from the lwIP contribution
package (1.4.1) on top of the lwIP 1.4.1 on an embedded system (using
the FreeRTOS). If I access the web server from a Windows PC with the
FireFox browser there is no problem and the pages are all shown like
expected. If I now use the same configuration and trying to access the
web server from a Linux PC (also with the FireFox browser) the pages are
not shown, because there are problems with the communication between the
PC and the lwIP.
The PCs are connected directly (point-to-point) to the embedded system
(means there is no switch, etc. between).

I have activated all the error checking inside the lwIP source code and
also enabled the statistic counters... but it does not show me any
problem. There are no error messages (and no stop trough the build-in
asserts) and the statistic counters look all good, even if a try to
access the web server with the Linux PC.

I have attached two Wireshark recordings, one done while connected with
the Windows PC and the other while connected with the Linux PC. If
somebody with more knowledge could have a look into the recordings and
maybe give me some hints what the problem could be.

Any help would be very welcome

Regards, Roland