smbclient messages to a specific user ?

[Cole, Timothy D.]

> -----Original Message-----
> From:	Dejan Ilic [SMTP:dejan.ilic at home.se]
> Sent:	Thursday, January 13, 2000 12:17
> To:	Multiple recipients of list SAMBA-NTDOM
> Subject:	smbclient messages to a specific user ?
> 
> Hello.
>  I'm using Samba 2.0.5a (PDC) and "smbclient -M" to send feedback messages
>  to users sitting on WinNT4 machines. The feedback is mostly accounting
>  information like number of pages left that the user can print, or quota
>  status when logging in etc.
> 
>  smbclient can send to a specific (netbiosname) machine but not to a
>  specific user on that machine. You can only supply the senders user, not
>  receiver. This is not a problem today as we have WinNT workstations where
>  only one user at time work, and the messages are usualy directed to that
>  user.
> 
>  But there are two problems with this limitation:
>  *) Ie when printing a lengthy document the user can log out, leave the
>     machine and got to the printer and wait for the printer to finish its
>     job. When the job is done the server will send a message to the
>     computer, but the user has left, and the message will be printed on
> the
>     loginscreen, or to the next user sitting on by the computer now!
> 
>     This could lead to some confusion and possibly leaking of semi-private
> 
>     information. I would like to avoid that if possible by directing the
>     message to a specific user on that machine. The other users should not
>     be able to see the message.
> 
>  *) The limitation will become unbearable when we start using WinNT 
>     Terminal Servers here. Sending a message to a TS could mean that all
>     the users logged in will se the message (?), when only one in realy
>     interested in the result. You could imagine a server with 20-35 users
>     logged in and every time someone prints or logs in everybody get a
>     message that they realy shouldn't receive.
> 
> Windows NT4 "net send" command has a possibility to send to a specific
> user. I must admit that I haven't used it, but it indicates that it should
> work.
> 
> Is it possible to extend smbclient so that it can send messages to a
> specific user on a specific machine (or domain), or is it a limitation in
> Windows implementation ? Hopefully implemented in a Samba 2.0.x :-)
> 
	Basically the way it works is that each user that logs in registers
a NetBIOS/WINS record:  username<03h>, with the IP of the machine they're
logged in on.  I believe when net send sends to a specific user, it looks up
this record, then dispatches the message to the messenger service at that
particular IP.

	I don't think it's any more involved than that, since it's not
unheard of to have problems with having two users with the same name in
different domains to each randomly get print notifications and other
messages intended for the other.  I think this is because the domain isn't a
component of the 0x03 name, so the most recent user to log in gets all
messages for all users with the same name in all domains.

	This also suggests to me that the actual windows messanging setup is
machine-based, rather than user-based.  I have really no idea how terminal
server copes with that, or if it even does.