Path: utzoo!attcan!cmtl01!matrox!uvm-gen!uunet!lll-winken!ames!pasteur!ucbvax!hplabs!pyramid!csg
From: csg@pyramid.pyramid.com (Carl S. Gutekunst)
Newsgroups: comp.mail.sendmail
Subject: Re: sendmail_5.61 and resolver
Message-ID: <56510@pyramid.pyramid.com>
Date: 26 Jan 89 05:58:54 GMT
References: <1201@uw-entropy.ms.washington.edu>
Organization: Pyramid Technology Corp., Mountain View, CA
Lines: 49

In article <1201@uw-entropy.ms.washington.edu> hubert@bogachiel.ms.washington.edu (Steve Hubert) writes:
>Some time in between version 5.52 and 5.61 of sendmail there were two
>new lines added to deliver.c that are causing me trouble, and I don't
>understand why they are there....
>
>	_res.options &= ~(RES_DEFNAMES | RES_DNSRCH);		/* XXX */
>	_res.options |= RES_DEFNAMES | RES_DNSRCH;	/* XXX */

Your analysis of these is correct. Their purpose is to force the resolver to
assume no default domain; i.e., your sendmail.cf must assemble a fully quali-
fied domain name before you call the [IPC] mailer. This rules out the use of
short local names.

Karl Kleinpaste and I were debating the pros and cons of it. Karl is a domain
purist, so at Ohio State his sendmail.cf always canonicalizes to FQDNs, no
matter where the mail is going. So Karl didn't even notice the above lines,
and if anything they are a Good Thing for him since they catch errors in the
sendmail.cf. 

Here at Pyramid, we have lots of naive users: sales, marketing, upper manage-
ment, the usual. :-) Many users don't like seeing "pyrpressure.pyramid.com"
when all they were trying to do was send mail to the person at the next desk;
they'd rather see the local name "pyrpressure". When that hits the resolver
with the above flags turned off, the resolver notices that there is no '.' in
the name, and promptly slings it back with a "no such host" error. This is
particularly annoying for me, since by this time I've already checked the name
against a list of known local hosts.

So I commented the lines back out. 

Note: sendmail 5.59, which is identical to 5.61 expect for security fixes, has
these lines commented out. It's what practically everyone has been running for
a couple of years. So I find it difficult to believe commenting them out is
catagorically wrong. I would say that anything that breaks an existing, work-
ing sendmail.cf *is* catagorically wrong. And this change does do that.

>So the question is, what are those two lines there for?

Karl and I decided it was Keith Bostic's way of telling everyone to use FQDNs.
:-) :-) :-)

>And what does the comment /* XXX */ mean?  That looks ominous, sort of like
>a skull and cross bones or something.

That is pretty close. That particular notation is even in some V7 code, and
its all over in the BSD kernel. Means something that is highly questionable,
or uncertain.

<csg>