need help on a plugins: bitwise of CDP value

[Rno]

Hello,
I'm developing a plugin that scan my network and via CDP memorise all switch/router, and the link between them.
For that I'm using CDP and the capabilities of the device. This capabilities is a binary ORed field with the following value:
Router: 0x01
TB Bridge: 0x02
SR Bridge: 0x04
Switch: 0x08
Host: 0x10
IGMP conditional filtering: 0x20
Repeater: 0x40
VoIP Phone: 0x80
Remotely-Managed Device: 0x100

for a switch it has to be 0x08, and that match most device; for Cisco Nexus switch, in L3 config, it's look like I have to get the code 0x200, to avoid Wifi Access point.
But I can make it work, the cdp data I get is an hex string with this value:
00 00 02 29

I try many different mix and data conversion, i'm still unable to figure out how to do a binary & between the CDP data and the hexcode of the Switch I have.

anyone willing to give me some help on this ?

[cigamit]

This should give you an example of how to decode it.

Code: Select all

$code = 0x0229;

$types = array(
  'Router' => 0x01,
  'TB Bridge' => 0x02,
  'SR Bridge' => 0x4,
  'Switch' => 0x08,
  'Host' => 0x10,
  'IGMP conditional filtering' => 0x20,
  'Repeater' => 0x40,
  'VoIP Phone' => 0x80,
  'Remotely-Managed Device' => 0x100,
  'Wifi AP' => 0x200
);

foreach ($types as $t => $c) {
	if ($code & $c) {
		print "$t\n";
	}
}

This should print

Router
Switch
IGMP conditional filtering
Wifi AP

[Rno]

Thanks finally I decide to use a case/switch situation, that let me filter some device that advertise itself as switch, but dose not fit my needs!!