[lwip-users] Re: lwip-users Digest, Vol 78, Issue 12

[Chen]

Simon,

With AVR port of lwIP, I can make connection and the second one will
actualy connected (pending?) but I can't do anything until I close the
first one

What do I need to do if I wish to have not even a single pending
connection, ie. RST it immediately? 

Thanks!

> Incoming connections will be sent a
> RST. However, this doesn't limit
> concurrent connections by default: it has been introduced to limit
> the
> outstanding-connection-queue for netconn- or socket-API. Normally,
> for
> the raw API, there is no such thing (that lies in the nature of the
> single-threaded callback mechanism). However, when using this
> feature,
> you have to call tcp_accepted from your appect function to decrease
> this
> counter. If you defer calling tcp_accepted and call it later, you
> can
> implement a concurrent-connection limitation.
>
> When using the socket- or netconn-API, the stack does this for you.
> Suppose you have one thread calling accept/recv/send/close in a loop
> and
> set the backlog to 1 then you will only have one active and one
> pending
> connection at a time and all other SYNs coming in will be
> RST'ed.
>
> Simon