Re: telnet "connection closed"

David Holland (dholland@eecs.harvard.edu)
Thu, 3 Apr 1997 10:47:47 -0500 (EST)


> >> This isnt a kernel question (I think).
> >> Does anyone know why if I telnet to someplace from a linux box and do cat
> >> <a big file> after a few lines I get "Connection closed"?
> >> Is this some flood protection?
>
> > I think it's a buffer overflow in the networking code. I noticed the
> > same thing when tarring 200 megabyte on my alpha last weekend using
> > the verbose flag on a 9600 baud terminal. It seems in.telnetd (in this
> > case a RedHat 4.1 alpha stock distribution) doens't handle it very
> > well.
>
> Nonsense. It's a known bug in the telnet program as distributed in
> NetKit-0.09. It's reproducible by telnetting to Solaris and HP-UX
> hosts (and presumably Linux hosts as well) and performing an 'ls'
> on a directory with a lot of entries, such as /usr/bin. Drop back
> to an older version of telnet and everything will be fine.

For everyone's information, here's the patch for this problem; it'll
be fixed in the next release of telnet.

-----BEGIN PGP SIGNED MESSAGE-----

This patch (against NetKit-0.09's telnet) should fix the problem where
it hangs up if asked to swallow lots of data at high speed on a
slowish terminal like an xterm window.

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`
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-- 
   - David A. Holland             |    VINO project home page:
     dholland@eecs.harvard.edu    | http://www.eecs.harvard.edu/vino