Re: [lwip-users] Server TCP RST prevents client code from draining the receive buffer.

[address@hidden]

Tim Cussins wrote:
> We've encountered a couple of interesting http servers in the wild that
> redirect, then send a TCP RST immediately.
> [..]
> In our case, the data for the redirect appears to make it into LWIP, but
> the subsequent RST causes the pcb to be discarded before we have an
> opportunity to read it. See tcp_in.c:377
That code doesn't mean you can't read the data.
[I strongly doubt that a server sends data *and* RST in one segment!]

Given that, I suspect you are using netconn or socket API.

> Any thoughts on the cleanest modification to LWIP that would allow the
> receive buffer to be drained?

Yes: task #13922 (Remove fatal error handling) has to be done first. 
"Fatal error handling"
currently prevents reads after a "fatal" error (e.g. RST received). 
Technically, this is not required
and you just provided a real-life reason to not do so.

You can expect a fix for 2.0.2 :-)

Simon