connections in CLOSED state

[Anton Yuzhaninov]

It seems to be there is some race and/or leak in tcp stack:

1. Netstat show connections in closed state (for a long time):

 > netstat -n | egrep '(Proto|CLOSED)'
Proto Recv-Q Send-Q  Local Address          Foreign Address       (state)
tcp4       0      0 10.25.1.54.35543       10.25.1.54.35544       CLOSED
tcp4       0      0 10.25.1.54.57273       10.25.1.54.57274       CLOSED
tcp4       0      0 10.25.1.54.40445       10.25.1.54.62378       CLOSED
tcp4       0      0 10.25.1.54.43403       10.25.1.54.43404       CLOSED
tcp4       0      0 10.25.1.54.36380       10.25.1.54.36381       CLOSED
...

2. sockstat don't show any processes to which this sockets can belong to.

some info from kgdb:

 > netstat -nA -p tcp | egrep '(Tcpcb|CLOSED)'
Tcpcb    Proto Recv-Q Send-Q  Local Address      Foreign Address   (state)
ffffff01abfb8370 tcp4       0      0 10.25.1.54.35543   10.25.1.54.35544   CLOSED

(kgdb) set $t = (struct tcpcb) *0xffffff01abfb8370
(kgdb) p $t->t_inpcb->inp_socket->so_count
$18 = 0

 > uname -srp
FreeBSD 8.2-PRERELEASE-20110101 amd64

-- 
  Anton Yuzhaninov