Sending a message to another computer on the network

Ian Smith smithi at
Sat Jun 5 23:16:31 PDT 2004

On Sat, 5 Jun 2004 freebsd-questions-request at wrote:

 > I'm on a FreeBSD 4.10-STABLE machine on 217.209.211.x ,
 > and would like to send a message to Win-box ( on the same network, but not my 
 > machine ) that's filling up my  httpd-access.log with junk.

Yes, these log-bombs are a pain, making it difficult (and slow) to scan
webserver logs with, say, less .. I had to write a script run hourly to
clean these out of our main apache and several vhost logs.

How can you be sure that they're coming from a Windows box, though?

 > The only thing I know is his IP-adress.
 > Is this possible ? If it is, how.
 > Or do I have to block his IP ?

Not much use if it changes, as you say yourself later .. best just send
a few of these log entries, with your later list of times received, to
your/his ISP asking for some action to hassle the (l)user concerned.

 > The junk I receive in my log looks like this :
 > -----------------
 > httpd-error.log :
 > <snip> [Sat Jun 05 14:13:43 2004] [error] [client] request 
 > failed: URI too long (longer than 8190)

Yes, they're all around 8300 bytes here, obvious buffer-overflow fodder,
though I don't know which webserver/s are targetted. Some days we get
between 10-20 per day from a range of IPs in the north-east Asia region,
where it's almost never any use trying to contact the ISPs concerned.

 > -----------------
 > httpd-access.log :
 > <snip>
 > - - [05/Jun/2004:14:11:28 +0200] "SEARCH /\x90\x02\xb1\
 > </snip>
 > and the last line ending with :
 > \x90\x90\x90\x90" 414 391 "-" "-"
 > ----------------

Them's the ones.  You're in a much better position than we are to stop
these, being (at least apparently) from IPs of your own ISP.

I'm unsure whether these are real attack attempts by some worm, or are
just designed as log bombs.  Either way, they got me scriptin' .. email
me (anyone) if you could use my apache.logclean sh script.  It's a bit
heavy-duty (having to stop apache briefly to clean logs) but has made
maintenance easier here, and kept log sizes down by up to 150K per day.

Cheers, Ian

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