async dns support

Netdisco/lib/App/Netdisco/Util/DNS.pm

@@ -4,11 +4,12 @@ use strict;
 use warnings FATAL => 'all';
 
 use Net::DNS;
+use AnyEvent::DNS;
 
 use base 'Exporter';
 our @EXPORT = ();
 our @EXPORT_OK = qw/
-  hostname_from_ip ipv4_from_hostname
+  hostname_from_ip hostnames_resolve_async ipv4_from_hostname
 /;
 our %EXPORT_TAGS = (all => \@EXPORT_OK);
 
@@ -75,5 +76,46 @@ sub ipv4_from_hostname {
   return undef;
 }
 
+=head2 hostnames_resolve_async( $ips )
+
+This method uses a fully asynchronous and high-performance pure-perl stub
+resolver C<AnyEvent::DNS>.
+
+Given a reference to an array of hashes will resolve the C<IPv4> or C<IPv6>
+address in the C<ip> or C<alias> key of each hash into its hostname which
+will be inserted in the C<dns> key of the hash.  The resolver does also
+forward-lookups to verify that the resolved hostnames point to the
+address.
+
+Returns the supplied reference to an array of hashes with dns values for
+addresses which resolved.
+
+=cut
+
+sub hostnames_resolve_async {
+  my $ips = shift;
+
+  my $resolver = AnyEvent::DNS->new();
+    
+  # Set up the condvar
+  my $done = AE::cv;
+  $done->begin( sub { shift->send } );
+
+  foreach my $hash_ref (@$ips) {
+    my $ip = $hash_ref->{'ip'} || $hash_ref->{'alias'};
+    $done->begin;
+    AnyEvent::DNS::reverse_verify $ip,
+            sub { $hash_ref->{'dns'} = shift; $done->end; };
+  }
+
+  # Decrement the cv counter to cancel out the send declaration
+  $done->end;
+
+  # Wait for the resolver to perform all resolutions
+  $done->recv;
+
+  return $ips;
+}
+
 1;
 

Netdisco/lib/App/Netdisco/Util/Device.pm

@@ -13,7 +13,6 @@ our @EXPORT_OK = qw/
   check_only
   is_discoverable
   is_arpnipable
-  can_nodenames
   is_macsuckable
 /;
 our %EXPORT_TAGS = (all => \@EXPORT_OK);
@@ -246,32 +245,6 @@ sub is_arpnipable {
   return 1;
 }
 
-=head2 can_nodenames( $ip )
-
-Given an IP address, returns C<true> if Netdisco on this host is permitted by
-the local configuration to resolve Node IPs to DNS names for the device.
-
-The configuration items C<nodenames_no> and C<nodenames_only> are checked
-against the given IP.
-
-Returns false if the host is not permitted to do this job for the target
-device.
-
-=cut
-
-sub can_nodenames {
-  my $ip = shift;
-  my $device = get_device($ip) or return 0;
-
-  return _bail_msg("can_nodenames device matched nodenames_no")
-    if check_no($device, 'nodenames_no');
-
-  return _bail_msg("can_nodenames: device failed to match nodenames_only")
-    unless check_only($device, 'nodenames_only');
-
-  return 1;
-}
-
 =head2 is_macsuckable( $ip )
 
 Given an IP address, returns C<true> if Netdisco on this host is permitted by