From owner-freebsd-security Wed Aug 9 6:52:51 2000 Delivered-To: freebsd-security@freebsd.org Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (Postfix) with ESMTP id 6DEB237BA2D for ; Wed, 9 Aug 2000 06:52:47 -0700 (PDT) (envelope-from wollman@khavrinen.lcs.mit.edu) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.3/8.9.3) id JAA18476; Wed, 9 Aug 2000 09:52:40 -0400 (EDT) (envelope-from wollman) Date: Wed, 9 Aug 2000 09:52:40 -0400 (EDT) From: Garrett Wollman Message-Id: <200008091352.JAA18476@khavrinen.lcs.mit.edu> To: "Vladimir Mencl, MK, susSED" Cc: FreeBSD-SECURITY Subject: Re: pine 4.21 port issues? In-Reply-To: References: <20000808201626.I261@speedy.gsinet> Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org < said: > Well, does anybody now, how the locking against the MTA is done? Using kernel file locking. > How do multiple copies of the MTA lock against each other (e.g., > multiple procmails) ? And how does finally an MUA lock against the > MTA ? Same way. > Is there a convention (or a standard) for this locking? It's defined by the local mail delivery agent (in FreeBSD, mail.local). If you read the manual page, this is quite clear. (Our mail.local also creates .lock files, but these cannot be relied upon. These files were originally created because early Unix didn't have file locking, and have persisted thanks to Sun brain-damage.) Using file locking permits MUAs to operate without any elevated privilege, without requiring a world-writable spool directory (although the MDA must still run as root in order to write to user mailboxes and potentially chown new mailboxes to their respective users). -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message