Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!mips!sgi!vjs@rhyolite.wpd.sgi.com
From: vjs@rhyolite.wpd.sgi.com (Vernon Schryver)
Newsgroups: comp.mail.uucp
Subject: Re: Imminent death of UUCP Zone predicted
Message-ID: <64757@sgi.sgi.com>
Date: 21 Jul 90 20:31:55 GMT
References: <707@logicon.com> <1990Jul16.200955.29906@chinet.chi.il.us> <26A73D1C.73C0@tct.uucp>
Sender: vjs@rhyolite.wpd.sgi.com
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 62


Something that has worked at sgi.sgi.com for several years is the following:

 1) Define a sendmail class set with an
	"FB /usr/lib/uucp/Systems #bad822 %s"
    to define a class of UUCP neighbors that think a!b@c is parsed a!(b@c).
    or that prepend "theirname!" to perfectly good "b@c" From:'s.
    
 2) Define a sendmail class set with an
	"FG /usr/lib/uucp/Systems #domain-host %s"
    to define a class of UUCP neighbors that understand RFC-822.
    
 3) Accept all reasonable and many unreasonable mixtures of RFC-822 addresses,
    822-source routes, UUCP routes, and so on
    In S0, rewrite everything into 822, converting ! routes to source routes.
    The class B defined in #1 is useful here.

 4) resolve to different mailers depending on whether the destination
    is (a) reached via SMTP, (b) reached via UUCP but the first hop is to a
    member of the class G defined in #2 above, or (c) dumb UUCP.

    In the mailers (a), (b), & (c), do the following to To: From: Cc: etc.:
	(a) -convert all UUCP to 822 source routes.  (Yes, source routes
	      are deprecated in 1123, but how else to comply with what
	      is may be a human's routing directive?)
	    -Leave simple 822 addresses alone.

	(b) -leave receipent (To: Cc:...) UUCP routes with more than one host
	      alone (of course after stripping our own hostname).
	      (e.g., a!b!c is unchanged, as is a!b.dom.ain!c)
	    -Convert a!b into b@a.
	    -Prepend our UUCP hostname to UUCP sender (e.g. From:) a!b!c
	    -Leave good 822 addresses alone.

	(c) -convert everything to ! routes, and prepend or strip
	      our UUCP hostname as required.

The main point is to rewrite addresses gatewayed to and from the UUCP
universe, and to distinquish between neighbors in the UUCP universe from
those in the RFC-822 universe who just happen to reached via UUCP
transport.  That latter happens fairly often, when it is inappropriate to
use NFSNET or when it would be nice to send email complaining that an
Internet link is broken.

Even when you have 50 or 100 active UUCP links, it turns out to be easy
to maintain this scheme.  Gradually, most of our UUCP neighbors have been
marked in what is now /usr/lib/uucp/Systems as understanding RFC-822.

"Be liberal in what you accept, conservative in what you send" applies
without saying.


The sendmail.cf files on the thousands of machines on the SGI network
are maintained with vi/emacs/etc.  That is not a big deal, because there
are only about 4 distinct files, with the rest being rcp'ed by
one of 3 shell scripts which change something like 3 lines to do things
like setting the local DNS domain and choosing a smart relay for strange stuff.


Vernon Schryver
Silicon Graphics
vjs@sgi.com