Subject: Re: How to time out dead ftpd processes

From: Gregory A Lundberg <[email-masked]>
Date: Thu, 10 Dec 1998 14:05:23 -0500 (EST)

On Thu, 10 Dec 1998, Steve DiBartolomeo wrote:

> In reply to my message about timing out dead processes you wrote:
> 
> -------------------------------------------------------------------------
> Set the idle time limit down.  Sayeth 'man ftpd':
> 
>        The  ftp server will timeout an inactive session after 15 minutes.
>        If the -t option is specified, the inactivity timeout period will
>        be set to timeout seconds.  A client may also request a different
>        timeout period;  the maximum period allowed may be set to timeout
>        seconds with the -T option.  The default limit is 2 hours.
> 
> -------------------------------------------------------------------------
> 
> Thanks, but this begs the question:
> 
> 1. why, if the default idle is 15 minutes, does this guy not get knocked
>    off after 15 minutes? In most cases these processes remain alive
>    indefinitely until I manually kill them.

But are they idle all that time?  I think not.

> 2. If the max default timeout -T = 2hours why isn't this guy knocked
>    off after two hours? Is it possible he keeps sending commands from
>    time to time.?

Almost certainly.  Either he does or he's going through a proxy which does
for him.  I've seen a bit of that, increasingly, recently.

> 3. Is there anyway I can determine if a client is sending a very
>    large timeout period himself?

The -T limits the very-large-ness the client may set.

What you didn't give in your first posting was the version you're running.
There are some bugs in some older versions (circa beta-8 through beta-12)
which left phantoms laying arround.  If you're not running beta-18,
upgrade to that version.

If you're running beta-18, then the guy is probably sending a NOOP every
few whiles to prevent the timeout.  The VR-series includes an option (on
by default) to deny NOOP reseting the timeout limits.  It also includes a
total-connect-time limit which you can configure in the ftpaccess file.
Current version is WU-FTPD 2.4.2 (beta-18) VR11, available from:

  ftp://ftp.vr.net/pub/wu-ftpd/

with several pre-compiled binaries available.

-- 

Gregory A Lundberg		Senior Partner, VRnet Company
1441 Elmdale Drive              [email-masked]
Kettering, OH 45409-1615 USA    1-800-809-2195

---

From: Steve DiBartolomeo <[email-masked]>
Date: Thu, 10 Dec 1998 10:50:10 -0800

In reply to my message about timing out dead processes
you wrote:

2. Is there anyway I can determine if a client is sending a very
   large timeout period himself?

Steve DiBartolomeo                    T (831) 426-6163
Applications Manager                  F (831) 426-2824
Artwork Conversion Software, Inc.     [email-masked]
Santa Cruz, CA 95060                  http://www.artwork.com