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lib/App/Netdisco/Util/Node.pm  view on Meta::CPAN

/;
our %EXPORT_TAGS = (all => \@EXPORT_OK);

=head1 NAME

App::Netdisco::Util::Node

=head1 DESCRIPTION

A set of helper subroutines to support parts of the Netdisco application.

There are no default exports, however the C<:all> tag will export all
subroutines.

=head1 EXPORT_OK

=head2 check_mac( $node, $device?, $port_macs? )

Given a MAC address, perform various sanity checks which need to be done
before writing an ARP/Neighbor entry to the database storage.

Returns false, and might log a debug level message, if the checks fail.

Returns a true value (the MAC address in IEEE format) if these checks pass:

=over 4

=item *

MAC address is well-formed (according to common formats)

=item *

MAC address is not all-zero, broadcast, CLIP, VRRP or HSRP

=back

Optionally pass a Device instance or IP to use in logging.

Optionally pass a cached set of Device port MAC addresses as the third
argument, in which case an additional check is added:

=over 4

=item *

MAC address does not belong to an interface on any known Device

=back

=cut

sub check_mac {
  my ($node, $device, $port_macs) = @_;
  return 0 if !$node;

  my $mac = NetAddr::MAC->new(mac => ($node || ''));
  my $devip = ($device ? (ref $device ? $device->ip : $device) : '');
  $port_macs ||= {};

  # incomplete MAC addresses (BayRS frame relay DLCI, etc)
  if (!defined $mac or $mac->errstr) {
      debug sprintf ' [%s] check_mac - mac [%s] malformed - skipping',
        $devip, $node;
      return 0;
  }
  else {
      # lower case, hex, colon delimited, 8-bit groups
      $node = lc $mac->as_ieee;
  }

  # broadcast MAC addresses
  return 0 if $mac->is_broadcast;

  # all-zero MAC addresses
  return 0 if $node eq '00:00:00:00:00:00';

  # CLIP
  return 0 if $node eq '00:00:00:00:00:01';

  # multicast
  if ($mac->is_multicast and not $mac->is_msnlb) {
      debug sprintf ' [%s] check_mac - multicast mac [%s] - skipping',
        $devip, $node;
      return 0;
  }

  # VRRP
  if ($mac->is_vrrp) {
      debug sprintf ' [%s] check_mac - VRRP mac [%s] - skipping',
        $devip, $node;
      return 0;
  }

  # HSRP
  if ($mac->is_hsrp or $mac->is_hsrp2) {
      debug sprintf ' [%s] check_mac - HSRP mac [%s] - skipping',
        $devip, $node;
      return 0;
  }

  # device's own MACs
  if ($port_macs and exists $port_macs->{$node}) {
      debug sprintf ' [%s] check_mac - mac [%s] is device port - skipping',
        $devip, $node;
      return 0;
  }

  return $node;
}

=head2 is_nbtstatable( $ip )

Given an IP address, returns C<true> if Netdisco on this host is permitted by
the local configuration to nbtstat the node.

The configuration items C<nbtstat_no> and C<nbtstat_only> are checked
against the given IP.

Returns false if the host is not permitted to nbtstat the target node.