NAME

Net::MAC::Vendor - look up the vendor for a MAC

SYNOPSIS

        use Net::MAC::Vendor;

        my $mac = "00:0d:93:29:f6:c2";

        my $array = Net::MAC::Vendor::lookup( $mac );

You can also run this as a script with as many arguments as you like. The module realizes it is a script, looks up the information for each MAC, and outputs it.

        perl Net/Mac/Vendor.pm 00:0d:93:29:f6:c2 00:0d:93:29:f6:c5
        
=head1 DESCRIPTION

The Institute of Electrical and Electronics Engineers (IEEE) assigns an Organizational Unique Identifier (OUI) to manufacturers of network interfaces. Each interface has a Media Access Control (MAC) address of six bytes. The first three bytes are the OUI.

This module allows you to take a MAC address and turn it into the OUI and vendor information. You can, for instance, scan a network, collect MAC addresses, and turn those addresses into vendors. With vendor information, you can often guess at what what you are looking at (e.g. an Apple product).

You can use this as a module as its individual functions, or call it as a script with a list of MAC addresses as arguments. The module can figure it out.

This module tries to persitently cache with DBM::Deep the OUI information so it can avoid using the network. If it cannot load DBM::Deep, it uses a normal hash (which is lost when the process finishes). You can preload this cache with the load_cache() function. So far, the module looks in the current working directory for a file named mac_oui.db to find the cache. I need to come up with a way to let the user set that location.

Functions

run( @macs )

If I call this module as a script, this class method automatically runs. It takes the MAC addresses and prints the registered vendor information for each address. I can pass it a list of MAC addresses and run() processes each one of them. It prints out what it discovers.

This method does try to use a cache of OUI to cut down on the times it has to access the network. If the cache is fully loaded (perhaps using load_cache), it may not even use the network at all.

lookup( MAC )

Given the MAC address, return an anonymous array with the vendor information. The first element is the OUI, the second element is the vendor name, and the remaining elements are the address lines. Different records may have different numbers of lines, although the first two should be consistent.

The normalize_mac() function explains the possible formants for MAC.

normalize_mac( MAC )

Takes a MAC address and turns it into the form I need to send to the IEEE lookup, which is the first six bytes in hex separated by hyphens. For instance, 00:0d:93:29:f6:c2 turns into 00-0D-93.

The input string can be a separated by colons or hyphens. They can omit leading 0's (which might make things look odd). We only need the first three bytes

        00:0d:93:29:f6:c2   # usual form
        
        00-0d-93-29-f6-c2   # with hyphens
        
        00:0d:93            # first three bytes
        
        0:d:93              # missing leading zero
        
        :d:93               # missing all leading zeros
        
=cut

sub normalize_mac
	{
	my $input = uc shift;

        my $mac   = join "-",
                grep { /^[0-9A-F]{2}$/ } 
                map { sprintf "%02X", hex }
                ( split /[:-]/, $input )[0..2];
        
        $mac = undef unless $mac =~ /^[0-9A-F]{2}-[0-9A-F]{2}-[0-9A-F]{2}$/;
        carp "Could not normalize MAC [$input]" unless $mac;
        
        return $mac;
        }

fetch_oui( MAC )

Looks up the OUI information on the IEEE website, or uses a cached version of it. Pass it the result of normalize_mac and you should be fine.

The normalize_mac() function explains the possible formants for MAC.

extract_oui_from_html( HTML )

Gets rid of the HTML around the OUI information. It may still be ugly. The HTML is the search results page of the IEEE ouisearch lookup.

parse_oui( STRING )

Takes a string that looks like

        00-03-93   (hex)            Apple Computer, Inc.
        000393     (base 16)        Apple Computer, Inc.
                                                                20650 Valley Green Dr.
                                                                Cupertino CA 95014
                                                                UNITED STATES

and turns it into an array of lines. It discards the first line, strips the leading information from the second line, and strips the leading whitespace from all of the lines.

load_cache

Downloads the current list of all OUIs, parses it with parse_oui(), and stores it in %Cached keyed by the OUIs (i.e. 00-0D-93). The fetch_oui() will use this cache if it exists.

SOURCE AVAILABILITY

This source is part of a SourceForge project which always has the latest sources in CVS, as well as all of the previous releases.

        http://sourceforge.net/projects/brian-d-foy/

If, for some reason, I disappear from the world, one of the other members of the project can shepherd this module appropriately.

AUTHOR

brian d foy <bdfoy@cpan.org>

COPYRIGHT

You may redistribute this under the same terms as Perl itself.