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From: Charles Forsyth <forsyth@terzarima.net>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] the meaning of group
Date: Mon, 28 Jan 2008 22:10:59 +0000	[thread overview]
Message-ID: <b97ed081ef4f66fcf0eaffc4b24adfd7@terzarima.net> (raw)
In-Reply-To: <876a8b7b9733e7f1321f06c5110772ae@quanstro.net>

> explain how it could be more elaborate.

it's completely up to them (as it is to fossil or kfs, which use a file /adm/users that they maintain themselves).
the location and representation of group membership, and its interpretation are all independent things.
that is, all three aspects could be handled by different services: for instance something like google's Chubby could
store a group map in s-expression form [unknown to chubby] but read and interpreted by other servers, even with
different interpretations of what that representation meant)

as another example, in a flash file system we did for inferno, there wasn't an /adm/users but a ctl file
of some sort received requests to manage a group membership similar to fossil console requests.

as a further example, SPKI's public key certificates can be used in various ways to establish group membership,
typically by producing a certificate stating that a given principal (represented by a public key)
is a member of a local name (ie group) rooted at another principal's public key. the latter principal
might correspond to the `owner' of a resource.  this example is more interesting than some of the others
because there isn't (in general) a group membership list; also SPKI itself allows delegation and compound
group names.

in your case, however, a simple scheme might have the kernel (or just a device) accept a ctl request that added
or removed a user name from a local group table, and then system start up script(s) would load the table from some agreed source
(and presumably one that's adequately reliable).  i think something like that was mentioned,
if not discussed, many months ago on the list.


  reply	other threads:[~2008-01-28 22:10 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-28 19:57 erik quanstrom
2008-01-28 20:29 ` Charles Forsyth
2008-01-28 20:33   ` erik quanstrom
2008-01-28 22:10     ` Charles Forsyth [this message]
2008-01-28 22:49       ` erik quanstrom
2008-01-28 23:06         ` Charles Forsyth
2008-01-28 23:35           ` erik quanstrom
2008-01-29  5:28             ` Bruce Ellis
2008-01-29 15:58             ` roger peppe

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