package App::Netdisco::Core::Arpnip;
use Dancer qw/:syntax :script/;
use Dancer::Plugin::DBIC 'schema';
use App::Netdisco::Util::Node 'check_mac';
use App::Netdisco::Util::DNS ':all';
use NetAddr::IP::Lite ':lower';
use Time::HiRes 'gettimeofday';
use base 'Exporter';
our @EXPORT = ();
our @EXPORT_OK = qw/ do_arpnip store_arp /;
our %EXPORT_TAGS = (all => \@EXPORT_OK);
=head1 NAME
App::Netdisco::Core::Arpnip
=head1 DESCRIPTION
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 do_arpnip( $device, $snmp )
Given a Device database object, and a working SNMP connection, connect to a
device and discover its ARP cache for IPv4 and Neighbor cache for IPv6.
Will also discover subnets in use on the device and update the Subnets table.
=cut
sub do_arpnip {
my ($device, $snmp) = @_;
unless ($device->in_storage) {
debug sprintf ' [%s] arpnip - skipping device not yet discovered', $device->ip;
return;
}
# get v4 arp table
my $v4 = _get_arps($device, $snmp->at_paddr, $snmp->at_netaddr);
# get v6 neighbor cache
my $v6 = _get_arps($device, $snmp->ipv6_n2p_mac, $snmp->ipv6_n2p_addr);
# get directly connected networks
my @subnets = _gather_subnets($device, $snmp);
# TODO: IPv6 subnets
# would be possible just to use now() on updated records, but by using this
# same value for them all, we _can_ if we want add a job at the end to
# select and do something with the updated set (no reason to yet, though)
my $now = 'to_timestamp('. (join '.', gettimeofday) .')';
# update node_ip with ARP and Neighbor Cache entries
store_arp(\%$_, $now) for @$v4;
debug sprintf ' [%s] arpnip - processed %s ARP Cache entries',
$device->ip, scalar @$v4;
store_arp(\%$_, $now) for @$v6;
debug sprintf ' [%s] arpnip - processed %s IPv6 Neighbor Cache entries',
$device->ip, scalar @$v6;
_store_subnet($_, $now) for @subnets;
debug sprintf ' [%s] arpnip - processed %s Subnet entries',
$device->ip, scalar @subnets;
$device->update({last_arpnip => \$now});
}
# get an arp table (v4 or v6)
sub _get_arps {
my ($device, $paddr, $netaddr) = @_;
my @arps = ();
while (my ($arp, $node) = each %$paddr) {
my $ip = $netaddr->{$arp};
next unless defined $ip;
next unless check_mac($device, $node);
push @arps, {
node => $node,
ip => $ip,
dns => undef,
};
}
debug sprintf ' resolving %d ARP entries with max %d outstanding requests',
scalar @arps, $ENV{'PERL_ANYEVENT_MAX_OUTSTANDING_DNS'};
my $resolved_ips = hostnames_resolve_async(\@arps);
return $resolved_ips;
}
=head2 store_arp( $mac, $ip, $name, $now? )
Stores a new entry to the C<node_ip> table with the given MAC, IP (v4 or v6)
and DNS host name.
Will mark old entries for this IP as no longer C<active>.
Optionally a literal string can be passed in the fourth argument for the
C<time_last> timestamp, otherwise the current timestamp (C<now()>) is used.
=cut
sub store_arp {
my ($hash_ref, $now) = @_;
$now ||= 'now()';
my $ip = $hash_ref->{'ip'};
my $mac = $hash_ref->{'node'};
my $name = $hash_ref->{'dns'};
schema('netdisco')->txn_do(sub {
my $current = schema('netdisco')->resultset('NodeIp')
->search(
{ ip => $ip, -bool => 'active'},
{ columns => [qw/mac ip/] })->update({active => \'false'});
schema('netdisco')->resultset('NodeIp')
->update_or_create(
{
mac => $mac,
ip => $ip,
dns => $name,
active => \'true',
time_last => \$now,
},
{
key => 'primary',
for => 'update',
});
});
}
# gathers device subnets
sub _gather_subnets {
my ($device, $snmp) = @_;
my @subnets = ();
my $ip_netmask = $snmp->ip_netmask;
my $localnet = NetAddr::IP::Lite->new('127.0.0.0/8');
foreach my $entry (keys %$ip_netmask) {
my $ip = NetAddr::IP::Lite->new($entry);
my $addr = $ip->addr;
next if $addr eq '0.0.0.0';
next if $ip->within($localnet);
next if setting('ignore_private_nets') and $ip->is_rfc1918;
my $netmask = $ip_netmask->{$addr};
next if $netmask eq '255.255.255.255' or $netmask eq '0.0.0.0';
my $cidr = NetAddr::IP::Lite->new($addr, $netmask)->network->cidr;
debug sprintf ' [%s] arpnip - found subnet %s', $device->ip, $cidr;
push @subnets, $cidr;
}
return @subnets;
}
# update subnets with new networks
sub _store_subnet {
my ($subnet, $now) = @_;
schema('netdisco')->txn_do(sub {
schema('netdisco')->resultset('Subnet')->update_or_create(
{
net => $subnet,
last_discover => \$now,
},
{ for => 'update' });
});
}
1;