#!/bin/sh
##########################################################
# Aleksander Adamowski <olo@altkom.com.pl>
# śro lut 26 15:52:05 CET 2003
# Skrypt przekazujacy dane do serwera pocztowego
# nasluchujacego na porcie 2500 i dopisujacy
# naglowek received od rblsmtpd
#
# The script adds a "Received" header based on info from
# rblsmtpd/tcpserver passed inside env variables
# and forwards data to a mail server that listens
# on a filtered port 2500
#
##########################################################

perl_filter='
use POSIX;


if (!defined($ENV{TCPREMOTEHOST})){
	$ENV{TCPREMOTEHOST}="unknownhost";
}
if (!defined($ENV{TCPREMOTEIP})){
	$ENV{TCPREMOTEIP}="127.0.0.1";
}
if (!defined($ENV{TCPLOCALHOST})){
	$ENV{TCPLOCALHOST}=$ENV{HOSTNAME};
}
$| = 1;
$data_notyet = 1;
$tls_notyet = 1;
setlocale(LC_TIME, "C");
$now=POSIX::strftime(" %a, %d %b %Y %H:%M:%S %z", localtime);

LINE:
while ($tls_notyet && ($_ = <>)) {
	# If STARTTLS detected, exit the loop and switch to byte-by-byte binary forwarding mode:
	if (/^starttls/i) {
		print $_ or die "-p destination: $!\n";
		$tls_notyet = 0;
	}
	last LINE if !$tls_notyet;
	if ($data_notyet) {
		if (s/(^data\r?\n)/$1Received: from $ENV{TCPREMOTEHOST} ([$ENV{TCPREMOTEIP}])\r\n    by $ENV{TCPLOCALHOST} (rblsmtpd);$now\r\n/im) {
			$data_notyet = 0;
			s/^(.{72})(.)$/$1\r\n    $2/gm;
		}
	}
} continue {
	print $_ or die "-p destination: $!\n";
}  

# STARTTLS occured, we have to forward all data byte-by-byte without buffering
# (as we cannot predict how long will the data be)
if (!$tls_notyet) {
	my $buf;
	while (sysread STDIN, $buf, 1) {
		syswrite STDOUT, $buf;
	}
}
'

if [ -n "$RBL_TRUSTED_NET" ]; then
  # the client is in a trusted net - we connect from 127.0.0.1 so that Netscape Messaging Server
  # can differentiate and allow relaying for this client:
	perl -e "$perl_filter" | nc -w 8 localhost 2500
else
  # the client is in an untrusted net - we connect from 127.0.0.3 so that Netscape Messaging Server
  # will block any relaying attempts using its antirelay plug-in:
	perl -e "$perl_filter" | nc -w 8 -s 127.0.0.3 localhost 2500
fi