samba - Feb 2003 - Starting a process from a windows client

I am hoping to run a Unix process from code running on a windows client, I
am told this can be done using Samba, does any one have any example code to
do this? 

Regards 
Ivan Scattergood 
London  Software Development
Internal 8-727-4929 (Lovat Lane)
Internal 8-727-4756 (Cannon Street)
External +44 (0) 20 7961 4929 
Fax +44 (0) 20 7961 4860 
<http://www.fidelity.co.uk>

> I am hoping to run a Unix process from code running on a windows client, I
> am told this can be done using Samba, does any one have any example code to
> do this?
I can't imagine how this would work. Perhaps ssh would be 
what you're looking for? There's an excellent windows client 
at http://www.chiark.greenend.org.uk/~sgtatham/putty/

>Date: Tue, 25 Feb 2003 11:23:34 -0000
>From: "Scattergood, Ivan" <Ivan.Scattergood@uk.fid-intl.com>
>To: "'samba@lists.samba.org'"
<samba@lists.samba.org>
>Subject: [Samba] Starting a process from a windows client 
>Message-ID:
<7B729E8C5D69D411B2B6001083FD190403321D43@ukldn703nts.ldn.uk.fid-intl.com>
>Content-Type: text/plain
>MIME-Version: 1.0
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>Message: 60
>
>I am hoping to run a Unix process from code running on a windows client, I
>am told this can be done using Samba, does any one have any example code to
>do this? 
>
>Regards 
>Ivan Scattergood 
>London  Software Development
>Internal 8-727-4929 (Lovat Lane)
>Internal 8-727-4756 (Cannon Street)
>External +44 (0) 20 7961 4929 
>Fax +44 (0) 20 7961 4860 
><http://www.fidelity.co.uk> 
The preexec option might help, for
example:

[procstrater]
path = /tmp
preexec = /usr/local/scripts/test.sh &
preexec close = yes   # ?
... other options (path etc.) ...

Now everytime a user accesses the procstrater share
the program gets startet with the users unix-access-rights
You may use root preexec = /...  and pass the Users
name as an option (root preexec = /test.sh %U).
Then the script is startet with root privileges (...warning...)
an the script can manage the user rights internaly with
the username passed in the command line.

I'm not sure about preexec close. If "test.sh"
returns a non-zero value the share gets closed according 
to the Samba-Documentation if this option is set.
This might prevent the share from staying open
and not executing preexec during the next connection
from the client. I never used the preexec close option.

Another option might be to "abuse" the print command,
for example:

[procstarter]
printable = yes
print command = /usr/local/scripts/test.sh &; rm %s
# or 
# print command = /usr/local/scripts/test.sh %s 
# print command = /usr/local/scripts/test.sh %U %s 
... other options (path etc.) ...

Now everytime a user "prints" something to the
procstarter-"printer" test.sh is startet with the users 
accessrights. You can set the script SUID root 
(...usual warnings about this....) and can manage the 
access rights internaly by passing the users name with %U.
Don't forget to remove the print-file (%s), to clean up
Or even more "tricky" bind a postscipt-printer-driver or
"text-only-driver" to the print-share. You can parse the 
print-file (Name in %s) for input to your process (and 
remove it afterwards). 
I'm not sure about the syntax but "man smb.conf"
should help you.
Both "share-access" and "printing" can be done 
from within a Windows-programm, when this is
what you mean by "code running on the client".

There may be better methods than using Samba
to start/control processes an a server (rpc, rmi).

Martin

Thanks for the Advice chaps. 

I have found out that I can run scripts through Xstart, the NT service
portion of or terminal program. It in turn uses SSH. I think that's going to
be the easiest solution. 

-----Original Message-----
From: Steve Williams [mailto:swilliams@rinax.com]
Sent: Tuesday, February 25, 2003 17:10
To: Jon Niehof
Cc: Scattergood, Ivan; 'samba@lists.samba.org'
Subject: Re: [Samba] Starting a process from a windows client


Hi,

An amazingly powerful tool that I have used before to accomplish what 
you are talking about.  **WARNING**  make sure that you consider 
security when you design your project, this is very powerful, hence 
DANGEROUS!

Cheers,
Steve

From
man smb.conf:

magic script (S)

    This parameter specifies the name of a file which, if opened, will
    be executed by the server when the file is closed. This allows a
    UNIX script to be sent to the Samba host and executed on behalf of
    the connected user.

    Scripts executed in this way will be deleted upon completion
    assuming that the user has the appropriate level of privilege and
    the file permissions allow the deletion.

    If the script generates output, output will be sent to the file
    specified by the /magic output/ <#MAGICOUTPUT> parameter (see above).

    Note that some shells are unable to interpret scripts containing
    CR/LF instead of CR as the end-of-line marker. Magic scripts must be
    executable /as is/ on the host, which for some hosts and some shells
    will require filtering at the DOS end.

    Magic scripts are /EXPERIMENTAL/ and should /NOT/ be relied upon.

    Default: /None. Magic scripts disabled./

    Example: *magic script = user.csh*





Jon Niehof wrote:
>> I am hoping to run a Unix process from code running on a windows 
>> client, I
>> am told this can be done using Samba, does any one have any example 
>> code to
>> do this?
>
> I can't imagine how this would work. Perhaps ssh would be what
you're
> looking for? There's an excellent windows client at 
> http://www.chiark.greenend.org.uk/~sgtatham/putty/
>
>
>