bin/67167: FreeBSDs ftpd has problems under -CURRENT

[dl at leo.org]

>Number:         67167
>Category:       bin
>Synopsis:       FreeBSDs ftpd has problems under -CURRENT
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue May 25 02:10:24 PDT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Daniel Lang <dl at leo.org>
>Release:        FreeBSD 5.2-CURRENT i386
>Organization:
LEO
>Environment:
System: FreeBSD atleo6.leo.org 5.2-CURRENT FreeBSD 5.2-CURRENT #1: Sun Apr 11 18:17:54 CEST 2004 langd at atleo6.leo.org:/usr/obj/usr/src/sys/ATLEO6 i386


>Description:

I run a heavily loaded ftp-server under FreeBSD 5.2-CURRENT.
I am using FreeBSD's own ftpd (/usr/libexec/ftpd) with the following
command-line to provide anonymous ftp access:

/usr/libexec/ftpd -A -D -l -W -r -S -a ftp.leo.org -p /var/run/ftpd.pid

I did so under -STABLE as well. Under -STABLE this performed
extraordinary well (much better than proftpd for instance).
Under -CURRENT every now and then, the system has trouble to
accept new connections. If a connection is established the data
transfer is very fast, but sometimes it takes very long to establish
the connection, such that clients do time out.

I also provide access via HTTP using apache2 linked with libthr.
I never have problems accepting connections over http. The throughput
is similar, maybe just slighlty below ftp (I get 10MB/s via FTP
and 9.3MB/s using HTTP to a machine in the LAN with a 100Mbit/s
NIC, so I can saturate the NIC on the client easily, the server
has a Gigabit NIC (em0)).

Further in the syslog I get tons of the following messages:
[..]
May 25 00:28:13 atleo6 ftpd[9248]: getsockname (/usr/libexec/ftpd): Socket operation on non-socket
May 25 00:30:18 atleo6 ftpd[7836]: getsockname (/usr/libexec/ftpd): Socket operation on non-socket
May 25 00:28:03 atleo6 ftpd[9228]: getsockname (/usr/libexec/ftpd): Socket operation on non-socket
May 25 00:34:02 atleo6 ftpd[9216]: getsockname (/usr/libexec/ftpd): Socket operation on non-socket
May 25 00:36:28 atleo6 ftpd[9698]: getsockname (/usr/libexec/ftpd): Socket operation on non-socket
May 25 00:37:07 atleo6 ftpd[9745]: getsockname (/usr/libexec/ftpd): Socket operation on non-socket
[..]

I know these are poor symptoms, but I am willing to dig into this
issue, if I get instructions. I have excluded INVARIANTS and WITNESS
from the kernel.

>How-To-Repeat:

Run a heavy loaded public ftp server under -current with FreeBSD's ftpd. 

>Fix:

unknown


>Release-Note:
>Audit-Trail:
>Unformatted: