How to determine is socket in working state

Hello, All!

I have a TCP server which listens on port, says, 8888 and I need to
know how many clients connections with this port really works. I mean
socket works, if it's in ESTABLISHED state _AND_ any traffic was
sent/received by it.

netstat isn't useful for this situation because of a lot of connections
could be in ESTABLISHED state between listen() and accept() system
calls, but they aren't working. Yes, I know about
/proc/net/ip_conntrack, but I need a portable solution to FreeBSD and
Solaris and I don't want to demand netfilter compiled to kernel from
users.

Does anyone know a portable utility which can help me?

Thanks,

-- Alexander