Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!gatech!hubcap!ncrcae!ncrlnk!ncrwic!encad!entec!jlohmeye
From: jlohmeye@entec.Wichita.NCR.COM (John Lohmeyer)
Newsgroups: comp.periphs
Subject: Re: SCSI CAM Questions
Message-ID: <308@entec.Wichita.NCR.COM>
Date: 27 Dec 88 03:53:07 GMT
References: <12872@cup.portal.com>
Reply-To: jlohmeye@entec.UUCP (John Lohmeyer)
Organization: NCR Corporation, Wichita, Kansas
Lines: 38

In article <12872@cup.portal.com> ts@cup.portal.com (Tim W Smith) writes:
>One of the desired features listed at that first CAM meeting was to
>allow both user and kernel access to SCSI.  Has anyone considered
>the security implications of this?  Even if CAM prevents used
>code from accessing devices that are being used by the kernel ( or
>other users ), there is still the problem of the COPY command.  Or
>will CAM have to restrict the SCSI commands available from user mode?
>
I doubt that anyone at the CAM meeting seriously regards CAM as a secure
interface.  The principal problem that the group set out to solve was to
allow software drivers to be independent of the installed host adapter.
As such, I regard this as a very low level interface and not necessarily
available to users.  Whether to allow user access depends on the operating
system policies.  If the system is MS-DOS, it probably would (couldn't really
prevent it).  Other systems with better security simply would not let the
user have access to such an interface.  They would have to do whatever is
necessary to enforce their own security rules.

There is a faction within the CAM group that wants a higher level interface
to be defined.  Perhaps even one that is independent of the I/O interface
below (e.g., SCSI, ESDI, ST506, etc.).  At this higher level, it is indeed
feasible (and perhaps desirable) to include security.  I would like to see
this higher level interface defined -- later.  Our first priority should be
the original task: to define a host adapter independent interface.  This
task is not too difficult to accomplish quickly and is really NEEDED. The
higher level interface will be a more difficult task and as such will take
more time.  (The difficulty is not technical, but rather political.)  Of
course, the higher level interface should use the low level interface when
talking to SCSI devices.

BTW, the next SCSI-2 CAM meeting is January 12 at the Red Lion Inn in Costa
Mesa, CA.  There is no charge for attending this meeting.  If you want
to get the mailings from the CAM Committee, there is a one-time charge of
$200.  If you want a voting membership, there is a $2000 charge which includes
one mailing subscription.  Contact Dal Allan at (408) 867-6630 for more
information.

John Lohmeyer   NCR Corporation   J.Lohmeyer@Wichita.NCR.COM