Mailing List Archive

serial device forwarding with conserver ?
Hi,

I am currently trying to make a (serial) device on one machine available to a
second machine and have started to play with conserver for this. I can connect
to the serial port in question via console.
Now what I'd like to do is create a local device from this, some kind of
/dev/ttyS0_over_conserver

Is this possible ?
And how would one go about ?

(The point is that I want to use a software program that accesses the device
and I need to tell it via an environment variable where to find it, usually
something a la /dev/ttyS0)

Thanks in advance,

Marc Baaden

--
Dr. Marc Baaden - Institut de Biologie Physico-Chimique, Paris
mailto:baaden@smplinux.de - http://www.baaden.ibpc.fr
FAX: +33 15841 5026 - Tel: +33 15841 5176 ou +33 609 843217


_______________________________________________
users mailing list
users@conserver.com
https://www.conserver.com/mailman/listinfo/users
Re: serial device forwarding with conserver ? [ In reply to ]
In a flurry of recycled electrons, Marc Baaden wrote:

> I am currently trying to make a (serial) device on one machine available to a
> second machine and have started to play with conserver for this. I can connect
> to the serial port in question via console.
> Now what I'd like to do is create a local device from this, some kind of
> /dev/ttyS0_over_conserver
>
> Is this possible ?
> And how would one go about ?

It depends....

If the software really wants a serial port, then nothing else will do
(for instance, if it tries to set speed/parity/etc). If all you need
is a device to open, you might try creating a named pipe and a program
to read from the pipe and write to a process running console. A short
tcl script should do that handily. Note in this that you don't
have any control over opening/closing the console connection because you
can't see whether the other side of the pipe is open. (I'm sure someone
will correct me on this.)

z!
_______________________________________________
users mailing list
users@conserver.com
https://www.conserver.com/mailman/listinfo/users
Re: serial device forwarding with conserver ? [ In reply to ]
conserver probably won't help you. there are programs like ser2net and
sredird that will take a serial port and allow you to access it over a
tcp connection, which sounds opposite of what you'd like. somewhere in
the back of my mind i remember seeing a package that takes a tcp
connection (to a terminal server or whatever) and presents it as a local
serial port. that's what you want. i can't, for the life of me, find
any reference to it, though. i do remember terminal server vendors
providing such behavior (local serial ports that access their term
servers) - maybe that's what's confusing me.

and, then again, it would probably have to be a kernel module...which
isn't triggering any memories either. if you don't need it to act like
a real serial port, you might be able to hack something together like
carl suggests.

Bryan
_______________________________________________
users mailing list
users@conserver.com
https://www.conserver.com/mailman/listinfo/users
Re: serial device forwarding with conserver ? [ In reply to ]
Hi,

thanks for all your suggestions.

corrigan@KiNETWORKS.com said:
>> If a /dev/pts type interface work for you, let me know and I can provide
>> further details

I think this would work. I would be interested in trying.


bryan@conserver.com said:
>> [..] i remember seeing a package that takes a tcp connection (to a terminal
>> server or whatever) and presents it as a local serial port. that's what you
>> want. [..]

Yes, I think that's right. I found something that does work (not as nicely
and swiftly as conserver, but for my occasional use it might be sufficient).
The package is called bidilink [1]. For my case this leads to a command:

bidilink "exec:ssh server bidilink tty:/dev/ttyS0" pty:TempDevice

It works, but is a little slower than on the local machine (I had thought
that FastEthernet should be sufficient for a smooth connection of a 9600 baud
device .. ?)
An additional point is that I want to serve /dev/ttyS0 from a linux box to
a Macintosh and there seem to be slight differences (eg no /dev/ptmx on the
mac).


cpz@tuunq.com said:
>> If all you need is a device to open, you might try creating a named pipe and
>> a program to read from the pipe and write to a process running console.

I did wonder whether a named pipe would work. Couldn't one connect the
console process directly to the pipe via some shell magic ?

Many thanks,
Marc

[1] http://0pointer.de/lennart/projects/bidilink/

--
Dr. Marc Baaden - Institut de Biologie Physico-Chimique, Paris
mailto:baaden@smplinux.de - http://www.baaden.ibpc.fr
FAX: +33 15841 5026 - Tel: +33 15841 5176 ou +33 609 843217


_______________________________________________
users mailing list
users@conserver.com
https://www.conserver.com/mailman/listinfo/users