#!/usr/bin/perl -wT
#
# /usr/local/sbin/localmkpostfixvirtual
# Copyright 2001-2006 Jonas Smedegaard <dr@jones.dk>
#
# $Id: localmkpostfixvirtual,v 1.26 2006-08-22 22:59:25 jonas Exp $
#
# Generate virtual file for postfix
#
# Hints are stored in the "Other" field (using chfn).
#
# Each user should have space-separated hints like this:
# "mailname1@ mailname2@mailgroup1 mailname3@mailgroup2 mailname4@maildomain7".
#
# The user of each mailgroup should have hints like "@domain1 @domain2"
# for each hosted maildomain.
#
# Generate virtual file like this:
#
#  # ( cd /etc/postfix && localmkpostfixvirtual > virtual.new && diff virtual virtual.new )
#
# ..and if the changes are correct, activate the new virtual file:
#
#  # ( cd /etc/postfix && mv virtual.new virtual && postmap virtual )
#
# Optional: Several mailgroups can be tied together (when amount of hints
# exceeds the limit of the "Other" field: List them all in
# "Office" or "roomnumber" field of primary mailgroup (include the
# primary mailgroup itself!).
#
# Optional: root can have hints like "postmaster@ hostmaster@ support@"
# for default accounts tied to the sysadmin (default: "postmaster@").
#
# Suggestion: Add mailgroup users like this:
# adduser --system --no-create-home --group --disabled-password <uid>
#

use strict;

use User::pwent;
use User::grent;
#use Data::Dumper;

my (%username, %fullname, %office, %workphone, %homephone, %other);
my (%username_by_gid, %addresshints, %domains);

while (my $pw = getpwent()) {

	$username_by_gid{$pw->gid} = $pw->name;
	($fullname{$pw->name}, $office{$pw->name}, $workphone{$pw->name}, $homephone{$pw->name}, $other{$pw->name}) = split /\s*,\s*/, $pw->gecos;
	if (defined($other{$pw->name})) {
		@{$addresshints{$pw->name}} = grep {/^([\.[:alnum:]_-]+|\+)?@([\.[:alnum:]_-]+)?$/} split /\s+/, $other{$pw->name};
	}
#DEBUG: ($pw->name eq "annette") and print STDERR Dumper(@{$addresses{$pw->name}});
}

my (%owner, %members, %groups);

while (my $gr = getgrent()) {

	$owner{$gr->name} = $username_by_gid{$gr->gid};
	$members{$gr->name} = $gr->members;
	foreach my $member (@{$members{$gr->name}}) {
		push @{$groups{$member}}, $gr->name unless (defined($owner{$gr->name}) and $gr->name eq $owner{$gr->name});
	}
}

my (%warned);

sub warnonce($$$) {
	my ($test, $id, $warning) = @_;

	if ($test) {
		return 1;
	}
	if ($warned{$id}) {
		return '';
	}
	print STDERR 'W: ' . $warning . "\n";
	$warned{$id} = 1;
	return '';
}

sub print_accounts($$$$) {
	my ($username, $mailgroup, $maildomain, $pre_text, $post_fallback_text) = @_;

	($pre_text) && print $pre_text . "\n";
	my $user_seen;
	my $joker_seen;
#DEBUG: print STDERR "$mailgroup $maildomain\n";
#DEBUG: ($username eq "annette") and print STDERR Dumper(@{$addresshints{$username}});
	if (not &warnonce(defined(@{$addresshints{$username}}), "addresshints_$username", "Skipping non-hinted username \"$username\".")) {
		return '';
	}
	my @localparthints = @{$addresshints{$username}};
	my @localparts = grep {s/(.+)@($mailgroup|$maildomain)?$/$1/} @localparthints;
	foreach my $localpart (@localparts) {
		for ($localpart) {
			if (/^\+$/) {
				if (!$joker_seen) {
					print "\@$maildomain $username\n";
					$joker_seen = $username;
				} else {
					print "#WARNING: Catch-all for $maildomain already set to $joker_seen!";
				}
			} else {
				print "$localpart\@$maildomain $username\n";
			}
		}
		$user_seen++;
	}
	print $post_fallback_text . "\n" if ($post_fallback_text && !$user_seen);
	print "\n";
}

sub usercomment($) {
	my $user = shift;
	my @s = ();

	if (&warnonce(defined($fullname{$user}), "fullname_$user", "User \"$user\" lacks fullname.")) {
		push @s, $fullname{$user};
	}
	if (&warnonce(defined(@{$groups{$user}}), "groups_$user", "User \"$user\" belongs to no (secondary) group.")) {
		push @s, '(' . join(' ', @{$groups{$user}}) . ')';
	}
	if (@s) {
		unshift @s, '#';
	}
	my $string = join(' ', @s);

	return "$string";
}

my $loop;
my @mailgroups = @ARGV ? @ARGV : @{$members{'maildomains'}};
foreach my $mailgroup (@mailgroups) {
	if (not &warnonce(defined(@{$addresshints{$mailgroup}}), "addresshints_$mailgroup", "Skipping empty mailgroup \"$mailgroup\".")) {
		next;
	}
	my @maildomainhints = @{$addresshints{$mailgroup}};
	my @maildomains = grep {s/^@(.+)/$1/} @maildomainhints;
	foreach my $maildomain (@maildomains) {
		my (@mailgroupowners, @mailusers);
		my @mailgroupgroups = split / +/, $office{$mailgroup};
		push @mailgroupgroups, $mailgroup unless (@mailgroupgroups);
		foreach my $mailgroupgroup (@mailgroupgroups) {
			push @mailgroupowners, $owner{$mailgroupgroup} if ($owner{$mailgroupgroup});
			push @mailusers, @{$members{$mailgroupgroup}};
		}
		my @mailgroupowners_sorted = sort @mailgroupowners;
		my @mailusers_sorted = sort @mailusers;
#DEBUG: print STDERR Dumper(@mailusers); die;
		if ($loop) {
			print "\n##################################################################\n\n";
		}
		$loop++;
		&print_accounts('root', $mailgroup, $maildomain, "$maildomain VIRTUAL", "postmaster\@$maildomain root");
		# Do mailgroup owners (and don't warn if there's no addresses attached)
		foreach my $mailgroupowner (@mailgroupowners_sorted) {
			&print_accounts($mailgroupowner, $mailgroup, $maildomain, '# ' . $fullname{$mailgroupowner} . ' (' . join(' ', @{$groups{$mailgroupowner}}) . ')');
		}
		# Do secondary mailgroup members
		foreach my $mailuser (@mailusers_sorted) {
#			&print_accounts($mailuser, $mailgroup, $maildomain, '# ' . $fullname{$mailuser} . ' (' . join(' ', @{$groups{$mailuser}}) . ')', "#WARNING: No addresses for $mailuser");
			&print_accounts($mailuser, $mailgroup, $maildomain, &usercomment($mailuser), "#WARNING: No addresses for $mailuser");
		}
	}
}