Nat reflection and udp

aldo · Sep 9, 2006, 10:44 PM

line 919 fwrite($inetd_fd, "{$starting_localhost_port}\tstream\t{$protocol}\tnowait/0\tnobody\t/usr/bin/nc nc -w 20 {$target} {$loc_pt}\n");
change this to
fwrite($inetd_fd, "{$starting_localhost_port}\tstream\t{$protocol}\tnowait/0\tnobody\t/usr/bin/nc nc -w 20 -u {$target} {$loc_pt}\n");

the problem with this seems to be that this line even though the case is udpsets both tcp and udp streams???? i am sure you might know what this means

line 1891 $ipfrules .= "pass in quick on ${$ifname_real} inet proto tcp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
change this to
$ipfrules .= "pass in quick on ${$ifname_real} inet proto udp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";

hope it helps alan

sullrich · Sep 9, 2006, 10:43 PM

Please issue these commands to test:

fetch -o /etc/inc/ http://www.pfsense.com/~sullrich/filter.inc
/etc/rc.filter_configure

aldo · Sep 9, 2006, 10:59 PM

switch($rule['protocol']) {
case "tcp/udp":
$protocol = "{ tcp udp }";
$ipfrules .= "pass in quick on ${$ifname_real} inet proto tcp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
$ipfrules .= "pass in quick on ${$ifname_real} inet proto udp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
break;
case "tcp":
case "udp":
$protocol = $rule['protocol'];
$ipfrules .= "pass in quick on ${$ifname_real} inet proto udp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
break;
default:
break;
}

**You need to add the case for tcp otherwise tcp get udp case set

the stream looks good but the local host rule needs the tcp case filled in i tested this and it worked fine
case "tcp":
$protocol = $rule['protocol'];
$ipfrules .= "pass in quick on ${$ifname_real} inet proto tcp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
break**;

sullrich · Sep 9, 2006, 11:00 PM

There is no break, it automatically hits the next case.

aldo · Sep 9, 2006, 11:00 PM

ok sorry i just stripped you code when pasting not mine

aldo · Sep 9, 2006, 11:03 PM

one last thing you have an extra white space on the udp stream now.
i did them both in clean cases before and all worked well

for the inetd i added info the the tcp case and the upd case as i did in the localhost allow rule your
solution was definatly neater but there is a whitespace issue

sullrich · Sep 9, 2006, 11:03 PM

Please test the file that I posted. It really should be working now.

sullrich · Sep 9, 2006, 11:03 PM

@aldo:

one last thing you have an extra white space on the udp stream now.
i did them both in clean cases before and all worked well

for the inetd i added info the the tcp case and the upd case as i did in the localhost allow rule your
solution was definatly neater but there is a whitespace issue

Not sure what you mean. Please show me either the generated rules from rules.debug or the netcat entries from inetd.conf

aldo · Sep 9, 2006, 11:06 PM

19000 stream udp nowait/0 nobody /usr/bin/nc nc -u -w 20 192.168.200.200 161
19002 stream tcp nowait/0 nobody /usr/bin/nc nc -w 20 192.168.200.200 8000

sullrich · Sep 9, 2006, 11:08 PM

Yeah it doesn't look "good" but it should work..

aldo · Sep 9, 2006, 11:11 PM

NAT Reflection rules

pass in quick on $lan inet proto udp from any to $loopback port 19000 keep state
label "NAT REFLECT: Allow traffic to localhost"
pass in quick on $lan inet proto udp from any to $loopback port 19001 keep state
label "NAT REFLECT: Allow traffic to localhost"

aldo · Sep 9, 2006, 11:12 PM

/* $Id: filter.inc,v 1.575.2.248 2006/09/09 22:53:48 sullrich Exp $ */

aldo · Sep 9, 2006, 11:14 PM

this definatly works correctly here

switch($rule['protocol']) {
case "tcp/udp":
$protocol = "{ tcp udp }";
$ipfrules .= "pass in quick on ${$ifname_real} inet proto tcp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
$ipfrules .= "pass in quick on ${$ifname_real} inet proto udp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
break;
case "tcp":
$protocol = $rule['protocol'];
$ipfrules .= "pass in quick on ${$ifname_real} inet proto tcp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
break;
case "udp":
$protocol = $rule['protocol'];
$ipfrules .= "pass in quick on ${$ifname_real} inet proto udp from any to $loopback port {$starting_localhost_port} keep state label "NAT REFLECT: Allow traffic to localhost"\n";
break;
default:
break;
}

NAT Reflection rules

pass in quick on $lan inet proto udp from any to $loopback port 19000 keep state
label "NAT REFLECT: Allow traffic to localhost"
pass in quick on $lan inet proto tcp from any to $loopback port 19001 keep state
label "NAT REFLECT: Allow traffic to localhost"

sullrich · Sep 9, 2006, 11:17 PM

Your not making any sense. Are you saying what is commited does not work? There is no difference, the udp case gets hit for tcp OR udp since there is no break.

Watch this example program:

$protocol = "tcp";

switch($protocol) {
case "tcp":
case "udp":
echo "case met";

}

?>

php -f test.php

case met#

As you can see since there is no break, the case "udp" gets processed for either.

Now consider this:

$protocol = "udp";

switch($protocol) {
case "tcp":
case "udp":
echo "case met";

}

?>

php -f test.php

case met#

As you can see you do not need to do it your way.

aldo · Sep 9, 2006, 11:20 PM

i agree but that was the result

sullrich · Sep 9, 2006, 11:24 PM

Rerun the commands that I mentioned earlier. I have updated the file to cover the tcp case either way.

I know for a fact that if other devs catch wind of this they are not going to like it. I would have to agree with them, this should not be necessary.

aldo · Sep 9, 2006, 11:46 PM

i see the issue scott

make the udp case empty above the tcp case
and fill in the tcp case but then look at your working cases in the rdr sections there is the issue
i reran the commands but there is an error in the filter.inc on 389 or thereabouts now as well i fixed an if that was missing an I

role it back scott i will work on it tomorrow i understand what youa re trying to achieve now and how you should do it using your method.
i will have better resourses tomorrow i am at home at moment and is 1am

i will send you the diffs tomorrow for your review

aldo · Sep 10, 2006, 12:20 AM

ok i think you will be happy with the localhost rules but not so pleased with the nc inetd bits
have a look and let me know

it works perfectly and that was my goal

filter.inc.txt

sullrich · Sep 10, 2006, 12:27 AM

Looks like you started with a dated filter.inc.

Can you:

#1 update your filter.inc and make the changes again
#2 send a diff -u patch? I need to also make these changes in -HEAD which this will assist with

aldo · Sep 10, 2006, 12:41 AM

will do it tomorrow for you got it working on a 7-9-06 box.

so will diff for you when i can