ssh foreign server problem

ssh foreign server problem

[Hal Snyder]

I'm having trouble using gnus's nifty ssh foreign host feature. Is it
me, or is there a bug?

I'm running ssh 1.2.26, GNU Emacs 20.3.1, pgnus-0.80, FreeBSD-3.0.

Ssh-agent is running and I have ssh-add'ed my id.

I have a shell account with an ISP, say "isp.com". This is not my main ISP
but they have newsgroups not available on the main news server I use. The
news server will not respond to hosts outside of isp.com.

If I do
  ssh -L 8119:news.isp.com:119 shell.isp.com
then I am able to access the server by configuring a server as follows:

  (nntp "foozle"
      (nntp-address "localhost")
      (nntp-port-number 8119)
      (nntp-record-commands t))
But this is messy.

OTOH, suppose I create another server, per the docs, to use pgnus's built-in
ssh proxying:
  (nntp "barzle"
      (nntp-address "shell.isp.com")
      (nntp-rlogin-program "ssh")
      (nntp-open-connection-function nntp-open-rlogin)
      (nntp-end-of-line "\n")
      (nntp-rlogin-parameters
       ("telnet" "news.isp.com" "nntp")))
When I try to open this server, there's a little traffic out to the
Internet, then gnus just sits there forever saying "Opening nntp
server on barzle...".

Manual telnet from shell.isp.com to news.isp.com, port 119 gets a
positive response from the news server.

I tried setting nntp-record-commands to "t", but nothing goes into the
*nntp-log* buffer.

Any ideas on what's wrong or how to debug this situation?

Re: ssh foreign server problem

[James H. Cloos Jr.]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

>>>>> "Hal" == Hal Snyder <DrXyzzy@mediaone.net> writes:

Hal> ("telnet" "news.isp.com" "nntp")))

I suspect the problem is the use of telnet(1).  Telnet(1) is not well
suited for non-interactive use.

I'd suggest installing netcat (nc(1)) and using that, if said isp.com
doesn't already have it installed.

One source for netcat is:

  <ftp://coast.cs.purdue.edu/pub/tools/unix/netcat/nc110.tgz>

There are other alternatives.  A Perl script, eg, is trivial if the
libnet modules are installed.

Just don't rely on telnet(1) for anything other than interactive use
to a tty.  At least based on my experience....

- -JimC
- -- 
James H. Cloos, Jr.  <http://www.jhcloos.com/cloos/public_key> 1024D/ED7DAEA6 
<cloos@jhcloos.com>     E9E9 F828 61A4 6EA9 0F2B  63E7 997A 9F17 ED7D AEA6
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v0.9.4 (GNU/Linux)
Comment: For info see http://www.gnupg.org

iD8DBQE27iJVmXqfF+19rqYRAhvjAKCZ7mjxJq4MMXHMVKM3SgLBgrxTugCcCLjs
aWT4LJxFSLWpSI7dsUKw0MM=
=bQmK
-----END PGP SIGNATURE-----

Re: ssh foreign server problem

[Hal Snyder]

Thanks! That did it. Never heard of netcat before, but have used
"socket" which seems similar. Anyway, putting nc out on "shell.isp.com"
and using it instead of telnet solved the problem.

Will send a patch for the docs tonight.

"James H. Cloos Jr." <cloos@jhcloos.com> writes:

> >>>>> "Hal" == Hal Snyder <DrXyzzy@mediaone.net> writes:
> 
> Hal> ("telnet" "news.isp.com" "nntp")))
> 
> I suspect the problem is the use of telnet(1).  Telnet(1) is not well
> suited for non-interactive use.
> 
> I'd suggest installing netcat (nc(1)) and using that, if said isp.com
> doesn't already have it installed.
> 
> One source for netcat is:
> 
>   <ftp://coast.cs.purdue.edu/pub/tools/unix/netcat/nc110.tgz>
> 
> There are other alternatives.  A Perl script, eg, is trivial if the
> libnet modules are installed.
> 
> Just don't rely on telnet(1) for anything other than interactive use
> to a tty.  At least based on my experience....

Re: ssh foreign server problem

[Hal Snyder]

Following up my own post:

The docs were right and I was wrong - the fact that ssh proxying
worked with nc(1) was due to my using a different connection. The
problem had nothing to do with gnus - emacs was coming up in a shell
(spawned by Gnome) that didn't see ssh-add's done from outside. Now it
works with telnet, too.

Hal Snyder <DrXyzzy@mediaone.net> writes:

> Thanks! That did it. Never heard of netcat before, but have used
> "socket" which seems similar. Anyway, putting nc out on "shell.isp.com"
> and using it instead of telnet solved the problem.
> 
> Will send a patch for the docs tonight.
> 
> "James H. Cloos Jr." <cloos@jhcloos.com> writes:
> 
> > >>>>> "Hal" == Hal Snyder <DrXyzzy@mediaone.net> writes:
> > 
> > Hal> ("telnet" "news.isp.com" "nntp")))
> > 
> > I suspect the problem is the use of telnet(1).  Telnet(1) is not well
> > suited for non-interactive use.
> > 
> > I'd suggest installing netcat (nc(1)) and using that, if said isp.com
> > doesn't already have it installed.
...