[lwip-users] HTTP server: sockets versus netconns

[Peter Woo]

I'm using lwip to write an http server. Initially I was using the netconn API, but I'm trying to switch to the sockets API since I find it a bit less awkward.

 

After this change, web clients now receive "connection reset" errors upon visiting a page. I've gotten it to work if the entire response is written in one lwip_send() call, but if for instance the header is written in a different call than the message body then the "connection reset" error occurs (I've checked this with a few browsers). I've checked using telnet to verify that identical data (at the payload level) is being received in either case. In other words

 

>   sprintf(outbuf, "<response header><response body>");

>   lwip_send(sock, outbuf, strlen(outbuf), 0);

>   lwip_close(sock);

 

works as expected but

 

>   sprintf(outbuf, "<response header>");

>   lwip_send(sock, outbuf, strlen(outbuf), 0);

>   sprintf(outbuf, "<response body>");

>   lwip_send(sock, outbuf, strlen(outbuf), 0);

>   lwip_close(sock);

 

does not. It still triggers the error if the MSG_MORE flag is passed to the first lwip_send(), which I thought might help. Neither does a "Connection: close" field in the response header make any difference.

 

 

What could be the issue here?