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#! /usr/bin/perl
# Gateway script for postfix to send to LDAP mail-enabled groups.
# $Id: postfix_groups.pl,v 1.6 2007/01/29 16:11:07 subbarao Exp $
#++
# NAME
# postfix_groups.pl 8
# SUMMARY
# Pipe mailer program for postfix to send to LDAP mail-enabled groups.
# SYNOPSIS
# postfix_groups.pl <sender> <nexthop> <recipient>
# DESCRIPTION
# postfix_groups.pl delivers mail to LDAP mail-enabled groups. It is
# intended to be invoked by \fBpipe\fR(8). Here is an example of a
# simple mail-enabled LDAP group:
#
# dn: cn=postfix-hackers, ou=Groups, o=hp.com
# .br
# objectClass: top
# .br
# objectClass: groupOfNames
# .br
# objectClass: mailGroup
# .br
# cn: postfix-hackers
# .br
# mail: postfix-hackers@groups.hp.com
# .br
# member: uid=lamont.jones@hp.com, ou=People, o=hp.com
# .br
# member: uid=kartik.subbarao@hp.com, ou=People, o=hp.com
#
# Here are excerpts from the people entries who are members of this group:
#
# dn: uid=lamont.jones@hp.com, ou=People, o=hp.com
# .br
# mailRoutingAddress: lamont@cranston.fc.hp.com
#
# dn: uid=kartik.subbarao@hp.com, ou=People, o=hp.com
# .br
# mailRoutingAddress: subbarao@quest.lf.hp.com
#
# postfix_groups.pl expands the incoming address
# postfix-hackers@groups.hp.com to the destination addresses
# lamont@cranston.fc.hp.com and subbarao@quest.lf.hp.com.
#
# CONFIGURATION
# To configure postfix_groups.pl to handle addresses of the form
# groupaddr@groups.mycompany.com, specify the following in \fBmaster.cf\fR:
#
# groups unix - n n - - pipe
# flags=q user=uucp argv=/path/to/postfix_groups.pl ${sender} ${nexthop} ${recipient}
#
# And the following in the \fBtransport\fR file:
#
# groups.mycompany.com groups:groups
#
# And the following in \fBmain.cf\fR (assuming an LDAP server
# ldap.mycompany.com with the root DN of o=mycompany.com):
#
# groups_destination_recipient_limit = 1
# groups_server_host = ldap.mycompany.com
# groups_search_base = o=mycompany.com
# groups_query_filter = (mail=%u@groups.mycompany.com)
# groups_result_attribute = mailRoutingAddress mgrpRFC822MailMember
# groups_special_result_attribute = member memberURL mgrpDeliverTo
# groups_domain = groups.mycompany.com
# groups_bind = no
#
# Note: The groups_* map should not be referenced in virtual_maps or
# elsewhere. Also note that the groups_destination_recipient_limit
# should be set to 1.
#
## [Describe main.cf parameters]
## TBD
#
## [Describe LDAP attributes that govern mail-enabled groups]
## TBD
#
# AUTHOR
# Kartik Subbarao <subbarao@computer.org>
#
# SEE ALSO
# \fBpipe\fR(8)
# http://www.watersprings.org/pub/id/draft-steinback-ldap-mailgroups-00.txt
# http://playground.sun.com/laser/0066.html
# RFC 2919
## TODO: Document implementation differences/enhancements by this script,
## compared to the draft spec.
#--
use Mail::Internet;
use Mail::Address;
use Net::SMTP;
use Net::LDAP qw (:all);
use URI;
use File::Basename;
use Sys::Syslog qw(:DEFAULT setlogsock);
use strict;
$ENV{'PATH'} = '/usr/local/bin:/usr/sbin:/usr/bin:/bin';
# Exit values from /usr/include/sysexits.h
my $DATAERR=65;
my $NOUSER=67;
my $SOFTWARE=70;
my $OSFILE=72;
my $NOPERM=77;
my $TEMPFAIL=75; # Most LDAP-related errors are transient failures
my $sender = shift(@ARGV); # ${sender}
my $map = shift(@ARGV); # ${nexthop} == map name
my $recipient = shift(@ARGV); # ${recipient}
my $debug = 0;
if ($debug && ! -t STDIN) {
open(STDOUT, "> /tmp/postfix_groups.stdout");
open(STDERR, "> /tmp/postfix_groups.stderr");
}
setlogsock('unix');
openlog(basename($0), 'pid', 'mail');
# Read postfix configuration from main.cf into %postconf hash
my $maincf_file = '/etc/postfix/main.cf';
my %postconf;
get_postfix_params($maincf_file, \%postconf);
my $ldap_host = $postconf{"${map}_server_host"} || 'localhost';
my $ldap_port = $postconf{"${map}_server_port"} || 389;
my $ldap_timeout = $postconf{"${map}_timeout"} || 120;
my $basedn = $postconf{"${map}_search_base"};
my @excluded_resolved_domains =
split(" ", $postconf{"${map}_excluded_resolved_domains"});
my $mail_attr = 'mail';
my $member_attr = 'member';
my @group_objectclasses = qw(groupOfNames groupOfURLs);
my @ldapurl_attrs = qw(memberURL mgrpDeliverTo);
my @default_result_attrs = split(" ", $postconf{"${map}_result_attribute"});
my @allowed_broadcaster_result_attrs = ($mail_attr, @default_result_attrs);
my $allowed_broadcaster_attr = 'mgrpAllowedBroadcaster';
my $errorsto_attr = 'mgrpErrorsTo';
my $addheader_attr = 'mgrpAddHeader';
my $removeheader_attr = 'mgrpRemoveHeader';
my $smtp_host = 'localhost'; # Use smtpd running on localhost
my $smtpd_recipient_limit = $postconf{smtpd_recipient_limit}
|| `postconf -h smtpd_recipient_limit`
|| 1000;
chomp $smtpd_recipient_limit;
# Read message from STDIN
my $message = Mail::Internet->new(\*STDIN, Modify => 0);
my $ldap = Net::LDAP->new($ldap_host,
port => $ldap_port,
timeout => $ldap_timeout)
or warn("$ldap_host: $@\n"), exit $TEMPFAIL;
## TODO: Explicitly specify the attributes retrieved by the first search, so
## that it can match the specific names as defined (e.g. member, etc)
my $ldapmesg = $ldap->search(base => $basedn,
filter => "(mail=$recipient)");
if ($ldapmesg->code) {
warn("$ldap_host: ", $ldapmesg->error, "\n");
exit $TEMPFAIL;
}
# $mail_attr is assumed to be a unique attribute
my $entry = $ldapmesg->entry(0)
or warn("Couldn't find entry for $recipient in $ldap_host\n"), exit $NOUSER;
my @allowed_broadcasters = $entry->get_value($allowed_broadcaster_attr);
my $errorsto = $entry->get_value($errorsto_attr);
my @addheaders = $entry->get_value($addheader_attr);
my @removeheaders = $entry->get_value($removeheader_attr);
my $header = $message->head;
$header->add('X-postfixgroups-version', ('$Revision: 1.6 $' =~ /\$Revision:\s+([^\s]+)/)[0]);
# Check if user is allowed to send to this list
my $from = (Mail::Address->parse($header->get('From:')))[0];
my $fromaddr = $from->address;
my @allowed_fromaddrs;
foreach my $allowed_broadcaster (@allowed_broadcasters) {
# Allowed broadcasters can be specified as a mailto: or ldap: URL.
my $uri = URI->new($allowed_broadcaster);
if ($uri->scheme eq 'ldap') {
# Expand the LDAP entry for all appropriate mail addresses,
my @attrs = $uri->attributes;
if (@attrs) {
# If attributes are specified in the LDAP URL,
# their values are expanded as DNs, instead of expanding
# the LDAP entry itself.
my $mesg = $ldap->search(base => $uri->dn,
scope => 'base',
filter => "(objectclass=*)",
attrs => \@attrs);
if ($mesg->code) {
if ($mesg->code == LDAP_NO_SUCH_OBJECT) {
syslog('warning', "Could not find allowed broadcaster " . $uri->dn);
next;
}
warn("$ldap_host: ", $mesg->error, "\n");
exit $TEMPFAIL;
}
my $entry = $mesg->entry(0) or next;
foreach my $dnval (map { $entry->get_value($_) } @attrs) {
push(@allowed_fromaddrs,
expand_entry(dn => $dnval,
resultattrs => \@allowed_broadcaster_result_attrs));
}
}
else {
# Expand the entry, and append to the list of allowed
# broadcaster addresses.
push(@allowed_fromaddrs,
expand_entry(dn => $uri->dn,
resultattrs => \@allowed_broadcaster_result_attrs));
}
}
elsif ($uri->scheme eq 'mailto') {
push(@allowed_fromaddrs, $uri->to);
}
else {
# Unknown scheme, treat it as an RFC 822 mail address
push(@allowed_fromaddrs, $allowed_broadcaster);
}
}
if (@allowed_fromaddrs) {
if (!grep(/^$fromaddr$/i, @allowed_fromaddrs)) {
warn("$fromaddr is not allowed to send to $recipient\n");
exit $NOPERM;
}
}
# Populate Errors-To: header if requested. Also adjust envelope sender.
if ($errorsto) {
# Only supports RFC 822 mail address specification for now
$errorsto =~ s/^mailto://;
$header->add(undef, "Errors-To: $errorsto");
$sender = $errorsto;
}
# Add List-Id header (defined in RFC 2919)
(my $listid = $recipient) =~ s/@/.list-id./;
$header->add('List-Id', $listid);
# Adjust message headers as appropriate
foreach my $addh (@addheaders) { $header->add(undef, $addh) }
foreach my $remh (@removeheaders) { $header->delete($remh) }
if ($debug) {
open(DEBUGMESSAGE, "> /tmp/postfix_groups.message");
$message->print(\*DEBUGMESSAGE);
close DEBUGMESSAGE;
}
# Get target addresses
my @alladdrs = expand_entry(entry => $entry);
# Exclude specified domains
my (@addrs, @excluded_addrs);
foreach my $addr (@alladdrs) {
my $excluded;
foreach my $domain (@excluded_resolved_domains) {
grep(/$domain$/, $addr) and $excluded = 1, last;
}
if ($excluded) { push(@excluded_addrs, $addr) }
else { push(@addrs, $addr) }
}
syslog('warning', "The following addresses were explicitly excluded from $recipient: " . join(',', @excluded_addrs))
if @excluded_addrs;
# Sort list of addresses by reversed domain name, to assist with bundling mail
@addrs = sort { lc(reverse($a)) cmp lc(reverse($b)) } @addrs;
$debug and print join("\n", @addrs) . "\n";
## TODO: do some more enhanced sorting to better collapse addresses,
## to minimize the number of messages sent out.
# Send the message
my $smtp = Net::SMTP->new($smtp_host, Debug => $debug)
or warn("Could not contact SMTP server on $smtp_host\n"), exit $TEMPFAIL;
my @badaddrs;
while (@addrs) {
my (@rcpt_to, @goodaddrs, %seen);
$smtp->mail($sender);
# Break up recipients based on $smtpd_recipient_limit
@rcpt_to = splice(@addrs, 0, $smtpd_recipient_limit);
@goodaddrs = $smtp->to(@rcpt_to, { SkipBad => 1 });
@seen{@goodaddrs} = ();
foreach my $addr (@rcpt_to) {
push(@badaddrs, $addr) unless exists $seen{$addr};
}
unless ($smtp->data(split(/^/m, $message->as_string))) {
warn("Message not accepted by SMTP server $smtp_host\n");
exit $SOFTWARE;
}
}
syslog('warning', "The following addresses were not accepted by the SMTP server on $smtp_host: " . join(',', @badaddrs))
if @badaddrs;
exit;
# Read postfix configuration from main.cf into a hash
sub get_postfix_params
{
my ($maincf_file, $hashref) = @_;
local $/ = undef;
open(MAINCF, $maincf_file) or warn("$maincf_file: $!\n"), exit $OSFILE;
my $maincfstr = <MAINCF>; close MAINCF;
$maincfstr =~ s/^#.*?\n//mg; # Get rid of comments
$maincfstr =~ s/\n[ \t]+/ /mg; # Collapse line continuation
foreach (split(/\n/, $maincfstr)) {
my ($param, $val);
($param, $val) = /\s*(\S+)\s*=\s*(.*?)\s*$/;
$hashref->{$param} = $val;
}
}
# Expand an LDAP entry, returning a list of results (culled for duplicates)
sub expand_entry
{
my %arg = (@_);
my (%results, @result_attrs);
my ($dn, $mesg, $entry, @entries, %seen);
@result_attrs = $arg{resultattrs}
? @{$arg{resultattrs}} : @default_result_attrs;
push(@entries, $arg{entry}) if $arg{entry}; # Passed as entry
push(@entries, $arg{dn}) if $arg{dn}; # Passed as DN
while (my $entry = shift(@entries)) {
unless (ref $entry) { # Actually a DN, get corresponding entry
my $dn = $entry;
$mesg = $ldap->search(base => $dn,
scope => 'base',
filter => "(objectclass=*)",
attrs => [ $mail_attr,
$member_attr,
@ldapurl_attrs,
@result_attrs ]);
if ($mesg->code) {
if ($mesg->code == LDAP_NO_SUCH_OBJECT) {
syslog('warning', "Could not find entry $dn");
next;
}
warn("$ldap_host: ", $mesg->error, "\n");
exit $TEMPFAIL;
}
$entry = $mesg->entry(0) or next;
}
# Add any result attributes of the entry itself to the results hash
foreach my $value (map { $entry->get_value($_) } @result_attrs) {
$results{$value} = 1;
}
# Add any static group member DNs to the list of entries
if ($entry->exists($member_attr)) {
# Break infinite loops from malformed nested groups
push(@entries, $entry->get_value($member_attr))
unless $seen{$entry->dn};
}
# Perform any specified dynamic queries
foreach my $query (map { $entry->get_value($_) } @ldapurl_attrs) {
my $uri = URI->new($query);
$mesg = $ldap->search(base => $uri->dn,
scope => $uri->scope,
filter => $uri->filter,
attrs => ['objectclass', @result_attrs]);
if ($mesg->code) {
if ($mesg->code == LDAP_NO_SUCH_OBJECT) {
syslog('warning', "Invalid base DN in $query\n");
next;
}
warn("$ldap_host: ", $mesg->error, "\n");
exit $TEMPFAIL;
}
# Add the result attributes of each group member to the results hash
foreach my $memberentry ($mesg->entries) {
foreach my $value (map { $memberentry->get_value($_) }
@result_attrs) {
$results{$value} = 1;
}
# Add any nested groups to the list of entries to be expanded
my $isgroup;
foreach my $oc (@group_objectclasses) {
grep(/^$oc$/i, $memberentry->get_value('objectClass'))
and $isgroup = 1, last;
}
if ($isgroup) {
# Check for infinite loops in nested groups
push(@entries, $memberentry->dn)
unless $seen{$memberentry->dn};
}
}
}
# Mark that we saw this entry's dn
$seen{$entry->dn} = 1;
}
return keys %results;
}
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