Re: What are port requirements for remote lisp?

>>>>> On Thu, 2 Apr 2020 14:16:55 -0400, Mirko Vukovic said:
> 
> On Thu, Apr 2, 2020 at 9:09 AM Martin Simmons <[email protected]> wrote:
> 
> > >>>>> On Thu, 2 Apr 2020 08:33:42 -0400, Mirko Vukovic said:
> > >
> > > On Thu, Apr 2, 2020 at 7:55 AM Martin Simmons <[email protected]>
> > wrote:
> > >
> > > > >>>>> On Wed, 1 Apr 2020 08:59:30 -0400, Mirko Vukovic said:
> > > > >
> > > > > On Tue, Mar 31, 2020 at 11:51 AM Martin Simmons <
> > [email protected]>
> > > > > 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:
> > > > > > >
> > > > > > >    1. 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.
> > > > > >
> > > > > >
> > > > > > >    2. 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.
> > > > > >
> > > > > >
> > > > > > >    3. 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
> > > >
> > > Here is the test log. Telnet and ssh debug are at the bottom.
> > > 1 Start slynk with :dont-close t
> > >
> > > Modified startup script:
> > >
> > > (let ((port 4005))
> > >     (slynk:create-server :port port :dont-close t)
> > >     (format t "~% Created SLYNK server on port ~a" port))
> > > (setf slynk:*use-dedicated-output-stream* nil)
> > >
> > > 2 Started tunnel with verbose option, -v switch
> > >
> > > $ ssh -v -L4005:hal9000:4005 mirko@hal9000
> > >
> > > 3 Telnet on laptop side to laptop port 4005
> > >
> > > @laptop> telnet localhost 4005
> > > Trying ::1...
> > > Connected to localhost.
> > > Escape character is '^]'.
> > > Connection closed by foreign host.
> > >
> > > 4 SSH debug output
> > >
> > > @hal9000> debug1: Connection to port 4005 forwarding to hal9000 port
> > > 4005 requested.
> > > debug1: channel 3: new [direct-tcpip]
> > > channel 3: open failed: connect failed: Connection refused
> > > debug1: channel 3: free: direct-tcpip: listening port 4005 for hal9000
> > > port 4005, connect from ::1 port 64100 to ::1 port 4005, nchannels 4
> >
> > It looks like hal9000 is resolving to the IPv6 localhost address ::1 on
> > hal9000, but the Lisp is probably only listening on IPv4.
> >
> > Try restarting the tunnel with -L4005:127.0.0.1:4005 to force IPv4.
> >
> > __Martin
> >
> 
> I restarted tunnel with IPv4: Now when I type something in the telnet
> session, I get Lisp to respond (with debugger in this case). Sly is still
> not connecting - maybe I need to restart emacs.
> 
> Log:
> 1 Start slynk with :dont-close t as before
> 2 Start tunnel with verbose option, -v switch and IPv4
> 
> $ ssh -v -L4005:127.0.0.1:4005 977315@hal9000
> 
> 3 Telnet on laptop side to laptop port 4005
> 
> @laptop> telnet localhost 4005
> Trying ::1...
> Connected to localhost.
> Escape character is '^]'.
> 
> 3.1 SSH debug output to telnet start
> 
> debug1: Connection to port 4005 forwarding to 127.0.0.1 port 4005 requested.
> debug1: channel 3: new [direct-tcpip]
> 
> 4 Send command via telnet session
> 
> Using telnet session send command:
> 
> *features*
> Connection closed by foreign host.
> 
> 4.1 Results in an error in lisp due to syntax error
> 
> ;; slynk:close-connection: Not an integer string: "*featu"
> ;; closing 0 channels
> ;; closing 0 listeners
> ;; Event history start:
> decode-message
> close-connection: Not an integer string: "\x00FF\x00F4\x00FF\x00FD\x00FF" ...
> close-connection Not an integer string:
> "\x00FF\x00F4\x00FF\x00FD\x00FF" ... done.

This \x00FF\x00F4\x00FF\x00FD\x00FF string is unexpected to me.  Did that
happen when you tried to connect from emacs?  Restarting emacs is probably a
good idea to rule out any issue with its state.


> decode-message
> close-connection: Not an integer string: "*featu" ...
> ;; Event history end.
> ;; Backtrace:
> 0: (NIL #<Unknown Arguments>)
> 1: (NIL #<Unknown Arguments>)
> 2: (SLYNK-BACKEND:CALL-WITH-DEBUGGING-ENVIRONMENT #<Compiled-function
> (:INTERNAL SLYNK::SAFE-BACKTRACE) (Non-Global)  #x302000A0BFFF>)
> 3: (SLYNK::SAFE-BACKTRACE)
> 4: (SLYNK::SIGNAL-SLYNK-ERROR #<CCL::PARSE-INTEGER-NOT-INTEGER-STRING
> #x302000C1F32D> NIL)
> 5: (SIGNAL #<CCL::PARSE-INTEGER-NOT-INTEGER-STRING #x302000C1F32D>)
> 6: (CCL::%ERROR #<CCL::PARSE-INTEGER-NOT-INTEGER-STRING
> #x302000C1F32D> (:STRING "*featu") 5975725205395)
> 7: (PARSE-INTEGER "*featu" :START 0 :END 6 :RADIX 16 :JUNK-ALLOWED NIL)
> 8: (SLYNK-RPC:READ-PACKET #<BASIC-TCP-STREAM ISO-8859-1 (SOCKET/4)
> #x302000BDFD9D>)
> 9: (SLYNK-RPC:READ-MESSAGE #<BASIC-TCP-STREAM ISO-8859-1 (SOCKET/4)
> #x302000BDFD9D> #<Package "SLYNK-IO-PACKAGE">)
> 10: (SLYNK::DECODE-MESSAGE #<BASIC-TCP-STREAM ISO-8859-1 (SOCKET/4)
> #x302000BDFD9D>)
> 11: (SLYNK::READ-LOOP #<MULTITHREADED-CONNECTION #x302000BDEFCD>)
> 12: (CCL::RUN-PROCESS-INITIAL-FORM #<PROCESS reader-thread(9) [Active]
> #x302000BFEFBD> (#<COMPILED-LEXICAL-CLOSURE (:INTERNAL
> CCL::%PROCESS-RUN-FUNCTION) #x302000BFED2F>))
> 13: ((:INTERNAL (CCL::%PROCESS-PRESET-INTERNAL (PROCESS))) #<PROCESS
> reader-thread(9) [Active] #x302000BFEFBD> (#<COMPILED-LEXICAL-CLOSURE
> (:INTERNAL CCL::%PROCESS-RUN-FUNCTION) #x302000BFED2F>))
> 14: ((:INTERNAL CCL::THREAD-MAKE-STARTUP-FUNCTION))
> ;; Connection to Emacs lost. [
> ;;  condition: Not an integer string: "*featu"
> ;;  type: CCL::PARSE-INTEGER-NOT-INTEGER-STRING
> ;;  style: :SPAWN]

This is working as expected -- the slynk/swank server is not a REPL so you
can't just send *features* to it.

__Martin