[SOLVED] Tcp connections hang on CLOSE

Client close the socket first, when there is not much data from server, tcp connection shutdown is okay like:

FIN -->
   <-- ACK
   <-- FIN, ACK
ACK -->

When the server is busying sending data:

FIN -->
    <-- ACK,PSH
RST -->

And the server connection comes to CLOSE_WAIT state and hang on there for a long time.

What's the problem here? client related or server related? This happens on Redhat5 for local sockets.

This article talk about why "RST" is sent, but I do not know why the server connection stuck on CLOSE_WAIT, and do not send a FIN out.

[EDIT]I ignored the most important information, this happens on qemu's slirp network emulation. It seems to be a problem of slirp bug for dealing with close connection.

Tcp connections hang on CLOSE_WAIT status