On Wed, 1 Apr 2020 08:59:30 -0400, Mirko Vukovic said:
On Tue, Mar 31, 2020 at 11:51 AM Martin Simmons martin@lispworks.com wrote:
> On Mon, 30 Mar 2020 21:16:00 -0400, Mirko Vukovic said:
Hello,
My setup is Sly on Spacemacs with Windows 10 running remote lisp on Linux over a corporate network. I have not found a Sly mailing list, and I
hope I
can get an answer here.
Emacs is running Sly on Spacemacs on Windows 10. Lisp is running on a
Linux
server. But Sly does not connect to the listening Lisp. Corporate network security policies have changed. I can ask for IT to accommodate me, but first I need to know what to ask for.
So far, I have opened a tunnel, and started a listening lisp (details below).
In Emacs I get:
sly-connect RET RET RET [sly] Connecting to Slynk on port 4005.. helm-M-x-execute-command: make client process failed: Connection timed
out,
:name, sly-9, :buffer, nil, :host, hal9000, :service, 4005, :nowait, nil, :tls-parameters, nil
The session transcript:
ssh -L4005:localhost:4005 mirko@hal9000
[mirko@hal9000 .roswell]$ ros -L ccl-bin run --load
start-slynk-server.lisp
Added SLYNK path to ASDF:*CENTRAL-REGISTRY* SLYNK's ASDF loader finished. Loaded ASDF system ;; Slynk started at port: 4005.
Created SLYNK server on port 4005 Set *USE-DEDICATED-OUTPUT-STREAM* to NIL Clozure Common Lisp Version 1.11.5/v1.11.5 (LinuxX8664)
For more information about CCL, please see http://ccl.clozure.com.
CCL is free software. It is distributed under the terms of the Apache Licence, Version 2.0. ?
My question is as follows:
- Do I need bi-directional traffic on 4005?
Assuming you are using the ssh tunnel above, then you don't need port 4005 traffic on the LAN (it is all hidden in the tunnel).
The most likely problem is that some firewall on the Windows machine is blocking port 4005. You may need to configure that firewall to allow ssh to listen on localhost:4005 and/or to accept connections to it from Spacemacs. In theory you might have similar localhost firewall issues on hal9000, but that is less likely.
- Do I need bi-directional traffic on 22? (after recent changes I
cannot ssh or scp into my Windows machine)
I'm assuming that you ran the ssh command on the Windows 10 machine and it gave you a working login to hal9000. If so, then it looks like you already have what you need for port 22.
Yes, I can log in to hal9000 with the -L switch:
ssh -L4005:localhost:4005 mirko@hal9000
Last login: Thu Mar 19 14:33:17 2020 from 172.27.236.189 [mirko@hal9000 ~]$
Note that bi-directional traffic on a connected socket is different from whether you can make a connection in both directions.
- What tools can I use to try to narrow down the cause of the
problem?
For instance, can I send a command to the lisp image, and see its
effects
on the lisp side?
Firstly, run "netstat -antp" on hal9000 to see if Lisp is listening on port 4005.
It looks that ccl-bin is listening: $ sudo netstat -antp | grep :4005 tcp 0 0 127.0.0.1:4005 0.0.0.0:* LISTEN 104461/lx86cl64
Secondly, run "netstat -anop tcp" on the Windows 10 machine to see if ssh is listening on port 4005.
I have Msys2's netstat. On the laptop:
which netstat
/c/WINDOWS/system32/netstat /c/Users/mirko/Downloads
netstat -anop tcp | grep :4005
TCP 127.0.0.1:4005 0.0.0.0:0 LISTENING 12052
Yes, both netstat outputs look good at that point.
Thirdly, run "ssh -p 4005 localhost" on the Windows 10 machine. This use a ssh is very bogus, but it should at least give an error message with some diagnostics. (Normally I would use telnet for this, but it is not installed on Windows 10 by default.)
Outputs of both ssh and telnet on the laptop:
which telnet
/usr/bin/telnet /c/Users/mirko/Downloads
telnet localhost 4005
Trying ::1... Connected to localhost. Escape character is '^]'. Connection closed by foreign host.
OK, so it is connected to the Windows side at least.
Check that the Slynk server was created with :dont-close t (or set slynk:*dont-close* to t before creating it). If dont-close is nil, it will only accept one connection, which makes debugging difficult.
Then restart the log in to hal9000 with -v option to ssh to make it print debug information:
ssh -v -L4005:localhost:4005 mirko@hal9000
and try the telnet again to see what is happening at the Linux end.
__Martin