Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site topaz.ARPA
Path: utzoo!watmath!clyde!cbosgd!cbdkc1!desoto!packard!topaz!hedrick
From: hedrick@topaz.ARPA (Chuck Hedrick)
Newsgroups: net.mail
Subject: Re: colons in mail addresses (domains and UCB Mail)
Message-ID: <1801@topaz.ARPA>
Date: Sat, 27-Apr-85 19:31:15 EDT
Article-I.D.: topaz.1801
Posted: Sat Apr 27 19:31:15 1985
Date-Received: Sun, 28-Apr-85 08:18:56 EDT
References: <684@plus5.UUCP> <1698@decwrl.UUCP> <485@decuac.UUCP> <498@decuac.UUCP>
Reply-To: hedrick@topaz.UUCP (Hedrick)
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 91


I believe you have fallen into a hack intended to support some obscure
syntax used only at UCB.  We discovered this when trying to fix Mail
so that replies didn't include my own name.  Let me clarify.  I
get a message
   from: foo!bar
   to: hedrick@topaz.arpa
I issue the "r" command, and get something like
   to: foo!bar, foo!hedrick@topaz.arpa
There is code that tries to eliminate your own name in this case.
However it looks only for "hedrick", not "hedrick@topaz".  Further
exploration shows that before doing this comparison a route-optimization
routine is called.  This is intended to turn foo!bar!baz!foo!user into
foo!user.  It is also supposed to turn hedrick@topaz into just plain
hedrick.  Unfortunately, it does not recognize topaz.arpa, just topaz.
It turns out that this is because our system name is set to topaz.
(If we set it to topaz.arpa, UUCP and other software do odd things.)
I did the obvious, which is to modify the routine that sets up the
internal host name to append .arpa *if there is no domain already*.
(Shortly we are going to be topaz.rutgers.edu, so we don't want .arpa
stuck on forever.)  At that point, I was shocked to see a reply go
to something like arpa:hedrick@topaz.  I looked a bit more into that
route optimization code, and concluded that I would never understand
it in finite time.  I replaced it with a simple version that understands
only normal RFC822 syntax, and everything works.  The only change
is in the module optim.c.  < is the new version, > the old.  The
majority of this code is in the routine arpafix, or something like
that, which is responsible for path optimization of addresses
involving Internet.  The idea is that anything@local-host should
be treated simply as anything.  It is then passed back through
the optimizer again.  This is so that foo!bar!baz!foo!user@local-host
will turn into foo!user.  We replace lots of complex tests with
the simple test for whether the host after the last @ or % is the
local host.  And when we recycle through the optimizer, we use
a local address of daemon, instead of host:LOCAL:daemon, or
whatever monstrosity was there before.  (This latter is what was
causing the stray colon.)  It is possible that our code does not
handle some odd case that the original code does handle, but it
seems to do the right thing in the cases that I understand.  I
believe that there are more horrors in optim.c just waiting to pounce
on you.  But I am reluctant to do anything to it until I see an
actual problem.

**** the following is a global declaration.  It can go anywhere before
**** the module arpafix
22,23d21
< char localhost[64];
< 
**** here is the main body of the change, in arpafix.
191c189,192
< 	if (!icequal(cp,localhost))
---
> 	arpamach = netlook(cp, '@');
> 	if (arpamach == 0) {
> 		if (debug)
> 			fprintf(stderr, "machine %s unknown, uses: %s\n", cp, name);
192a194,200
> 	}
> 	if (((nettype(arpamach) & nettype(LOCAL)) & ~AN) == 0) {
> 		if (debug)
> 			fprintf(stderr, "machine %s known but remote, uses: %s\n",
> 			    cp, name);
> 		return(name);
> 	}
198c206,214
< 	strcpy(fakepath, "daemon");
---
> 	fake[0] = arpamach;
> 	fake[1] = ':';
> 	fake[2] = LOCAL;
> 	fake[3] = ':';
> 	fake[4] = 0;
> 	prefer(fake);
> 	strcpy(fakepath, netname(fake[0]));
> 	stradd(fakepath, fake[1]);
> 	strcat(fakepath, "daemon");
**** the following is once-only code that sets up the internal host name.
695d710
< 
698a714
> 	static char host[64];
700,702c716
< 	gethostname(localhost, sizeof localhost);
< 	if (!any('.',localhost))
< 		strcat(localhost,".arpa");
---
> 	gethostname(host, sizeof host);
710c724
< 	np->nt_machine = localhost;
---
> 	np->nt_machine = host;