(RADIATOR) PreClientHook for decoding Cisco NAS-Port attribute

[Hugh Irvine]

Hello Everyone -

Many of you have asked questions about how to deal with Cisco NAS-Port 
attributes, so here is a hook I wrote recently that shows one way of dealing 
with the encoded information.

regards

Hugh


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# cisco-nas-port.pl
# PreClientHook to extract NAS-Port information.
#
# Cisco encodes information in the NAS-Port attribute as follows:
#
# nl-rt-sh-vpn-aer11(config)#radius-server attribute nas-port format ?
#� a �Format is type, channel, port
#� b �Either interface(16) or isdn(16), async(16)
#� c �Data format(bits): shelf(2), slot(4), port(5), channel(5)
#� d �Data format(bits): slot(4), module(1), port(3), vpi(8), vci(16)
#
# This hook is written for Cisco format "d" above (ATM vpi/vci).
#
# The encoded information is extracted and the individual data elements
# are added to the request packet as pseudo-attributes.
#
# Hugh Irvine, Open System Consultants, 20010622

sub
{
	my $p = ${$_[0]};

	my $nasport = $p->get_attr('NAS-Port');

	if (defined($nasport))
	{
		my ($slot, $module, $port, $vpi, $vci);
		$vci = $nasport & 0xffff;
		$nasport = $nasport >> 16;
		$vpi = $nasport & 0xff;
		$nasport = $nasport >> 8;
		$port = $nasport & 0x7;
		$nasport = $nasport >> 3;
		$module = $nasport & 0x1;
		$nasport = $nasport >> 1;
		$slot = $nasport & 0xf;
		$p->add_attr('Cisco-NAS-Port-Vci', $vci)
			if defined $vci;
		$p->add_attr('Cisco-NAS-Port-Vpi', $vpi)
			if defined $vpi;
		$p->add_attr('Cisco-NAS-Port-Port', $port)
			if defined $port;
		$p->add_attr('Cisco-NAS-Port-Module', $module)
			if defined $module;
		$p->add_attr('Cisco-NAS-Port-Slot', $slot)
			if defined $slot;
	}
}