#!/usr/local/bin/perl
##
## Sendmail mailer for Mailman
##
## Simulates these aliases:
##
##testlist:              "|/home/mailman/mail/mailman post testlist"
##testlist-admin:        "|/home/mailman/mail/mailman admin testlist"
##testlist-bounces:      "|/home/mailman/mail/mailman bounces testlist"
##testlist-confirm:      "|/home/mailman/mail/mailman confirm testlist"
##testlist-join:         "|/home/mailman/mail/mailman join testlist"
##testlist-leave:        "|/home/mailman/mail/mailman leave testlist"
##testlist-owner:        "|/home/mailman/mail/mailman owner testlist"
##testlist-request:      "|/home/mailman/mail/mailman request testlist"
##testlist-subscribe:    "|/home/mailman/mail/mailman subscribe testlist"
##testlist-unsubscribe:  "|/home/mailman/mail/mailman unsubscribe testlist"
##owner-testlist:        testlist-owner

## Some assembly required.
$MMWRAPPER = "/etc/mail/mailman";
$MMLISTDIR = "/etc/mailman/lists";
$SENDMAIL = "/usr/lib/sendmail -oem -oi";
$VERSION = '$Id: mm-handler,v 1.2 2002/04/05 19:41:09 bwarsaw Exp $';

## Comment this if you offer local user addresses.
$NOUSERS = "\nPersonal e-mail addresses are not offered by this server.";

# uncomment for debugging....
#$DEBUG = 1;

use FileHandle;
use Sys::Hostname;
use Socket;

($VERS_STR = $VERSION) =~ s/^\$\S+\s+(\S+),v\s+(\S+\s+\S+\s+\S+).*/\1 \2/;

$BOUNDARY = sprintf("%08x-%d", time, time % $$);

## Informative, non-standard rejection letter
sub mail_error {
	my ($in, $to, $list, $server, $reason) = @_;
	my $sendmail;

	if ($server && $server ne "") {
		$servname = $server;
	} else {
		$servname = "This server";
		$server = &get_ip_addr;
	}

	#$sendmail = new FileHandle ">/tmp/mm-$$";
	$sendmail = new FileHandle "|$SENDMAIL $to";
	if (!defined($sendmail)) {
		print STDERR "$0: cannot exec \"$SENDMAIL\"\n";
		exit (-1);
	}

	$sendmail->print ("From: MAILER-DAEMON\@$server
To: $to
Subject: Returned mail: List unknown
Mime-Version: 1.0
Content-type: multipart/mixed; boundary=\"$BOUNDARY\"
Content-Disposition: inline

--$BOUNDARY
Content-Type: text/plain; charset=us-ascii
Content-Description: Error processing your mail
Content-Disposition: inline

Your mail for $list could not be sent:
	$reason

For a list of publicly-advertised mailing lists hosted on this server,
visit this URL:
	http://$server/

If this does not resolve your problem, you may write to:
	postmaster\@$server
or
	mailman-owner\@$server


$servname delivers e-mail to registered mailing lists
and to the administrative addresses defined and required by IETF
Request for Comments (RFC) 2142 [1].
$NOUSERS

The Internet Engineering Task Force [2] (IETF) oversees the development
of open standards for the Internet community, including the protocols
and formats employed by Internet mail systems.

For your convenience, your original mail is attached.


[1] Crocker, D. \"Mailbox Names for Common Services, Roles and
    Functions\".  http://www.ietf.org/rfc/rfc2142.txt

[2] http://www.ietf.org/

--$BOUNDARY
Content-Type: message/rfc822
Content-Description: Your undelivered mail
Content-Disposition: attachment

");

	while ($_ = <$in>) {
		$sendmail->print ($_);
	}

	$sendmail->print ("\n");
	$sendmail->print ("--$BOUNDARY--\n");

	close($sendmail);
}

## Get my IP address, in case my sendmail doesn't tell me my name.
sub get_ip_addr {
	my $host = hostname;
	my $ip = gethostbyname($host);
	return inet_ntoa($ip);
}

## Split an address into its base list name and the appropriate command
## for the relevant function.
sub split_addr {
	my ($addr) = @_;
	my ($list, $cmd);
	my @validfields = qw(admin bounces confirm join leave owner request
				subscribe unsubscribe);

	if ($addr =~ /(.*)-(.*)\+.*$/) {
		$list = $1;
		$cmd = "$2";
	} else {
		$addr =~ /(.*)-(.*)$/;
		$list = $1;
		$cmd = $2;
	}
	if (grep /^$cmd$/, @validfields) {
		if ($list eq "owner") {
			$list = $cmd;
			$cmd = "owner";
		}
	} else {
		$list = $addr;
		$cmd = "post";
	}

	return ($list, $cmd);
}

## The time, formatted as for an mbox's "From_" line.
sub mboxdate {
	my ($time) = @_;
	my @days = qw(Sun Mon Tue Wed Thu Fri Sat);
	my @months = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);
	my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) =
		localtime($time);

	## Two-digit year handling complies with RFC 2822 (section 4.3),
	## with the addition that three-digit years are accommodated.
	if ($year < 50) {
		$year += 2000;
	} elsif ($year < 1900) {
		$year += 1900;
	}

	return sprintf ("%s %s %2d %02d:%02d:%02d %d",
		$days[$wday], $months[$mon], $mday,
		$hour, $min, $sec, $year);
}

BEGIN: {
	$sender = undef;
	$server = undef;
	@to = ();
	while ($#ARGV >= 0) {
		if ($ARGV[0] eq "-r") {
			$sender = $ARGV[1];
			shift @ARGV;
		} elsif (!defined($server)) {
			$server = $ARGV[0];
		} else {
			push(@to, $ARGV[0]);
		}
		shift @ARGV;
	}

	if ($DEBUG) {
		$to = join(',', @to);
		print STDERR "to: $to\n";
		print STDERR "sender: $sender\n";
		print STDERR "server: $server\n";
		exit(-1);
	}

ADDR:	for $addr (@to) {
		$prev = undef;
		$list = $addr;

		$cmd= "post";
		if (! -f "$MMLISTDIR/$list/config.pck") {
			($list, $cmd) = &split_addr($list);
			if (! -f "$MMLISTDIR/$list/config.pck") {
				$was_to = $addr;
				$was_to .= "\@$server" if ("$server" ne "");
				mail_error(\*STDIN, $sender, $was_to, $server,
					"no list named \"$list\" is known by $server");
				next ADDR;
			}
		}

		$wrapper = new FileHandle "|$MMWRAPPER $cmd $list";
		if (!defined($wrapper)) {
			## Defer?
			print STDERR "$0: cannot exec ",
				"\"$MMWRAPPER $cmd $list\": deferring\n";
			exit (-1);
		}

		# Don't need these without the "n" flag on the mailer def....
		#$date = &mboxdate(time);
		#$wrapper->print ("From $sender  $date\n");

		# ...because we use these instead.
		$from_ = <STDIN>;
		$wrapper->print ($from_);

		$wrapper->print ("X-Mailman-Handler: $VERSION\n");
		while (<STDIN>) {
			$wrapper->print ($_);
		}
		close($wrapper);
	}
}