NAME

POE::Component::Client::DNSBL - A component that provides non-blocking DNSBL lookups

SYNOPSIS

  use strict;
  use POE qw(Component::Client::DNSBL);

  die "Please provide at least one IP address to lookup\n" unless scalar @ARGV;

  my $dnsbl = POE::Component::Client::DNSBL->spawn();

  POE::Session->create(
	package_states => [
	    'main' => [ qw(_start _stop _response) ],
	],
	heap => { 
		  addresses => [ @ARGV ], 
		  dnsbl => $dnsbl 
	},
  );

  $poe_kernel->run();
  exit 0;

  sub _start {
     my ($kernel,$heap) = @_[KERNEL,HEAP];
     $heap->{dnsbl}->lookup(
	event => '_response',
	address => $_,
     ) for @{ $heap->{addresses} };
     return;
  }

  sub _stop {
     my ($kernel,$heap) = @_[KERNEL,HEAP];
     $kernel->call( $heap->{dnsbl}->session_id(), 'shutdown' );
     return;
  }

  sub _response {
     my ($kernel,$heap,$record) = @_[KERNEL,HEAP,ARG0];
     if ( $record->{error} ) {
	print "An error occurred, ", $record->{error}, "\n";
	return;
     }
     if ( $record->{response} eq 'NXDOMAIN' ) {
	print $record->{address}, " is okay\n";
	return;
     }
     print join( " ", $record->{address}, $record->{response}, $record->{reason} ), "\n";
     return;
  }

DESCRIPTION

POE::Component::Client::DNSBL is a POE component that provides non-blocking DNS blacklist lookups to other components and POE sessions. It uses POE::Component::Client::DNS to perform the requested queries.

Only IPv4 lookups are supported and unless a DNSBL zone is specified the component will use zen.spamhaus.org.

CONSTRUCTOR

spawn

Takes a number of parameters:

'alias', set an alias that you can use to address the component later;
'options', a hashref of POE session options;
'dnsbl', the DNSBL zone to send queries to, default zen.spamhaus.org;
'resolver', optionally provide a POE::Component::Client::DNS to use;

Returns an object.

METHODS

session_id

Takes no arguments. Returns the ID of the component's session.

shutdown

Terminates the component.

lookup

Performs a DNSBL lookup. Takes a number of parameters:

'event', the name of the event to send the reply to. ( Mandatory );
'address', the IPv4 address to lookup ( Mandatory );
'session', send the resultant event to an alternative session, ( default is the sender );

You may also pass arbitary key/values. Arbitary keys should have an underscore prefix '_'.

INPUT EVENTS

shutdown

Terminates the component.

lookup

Performs a DNSBL lookup. Takes a number of parameters:

'event', the name of the event to send the reply to. ( Mandatory );
'address', the IPv4 address to lookup ( Mandatory );
'session', send the resultant event to an alternative session, ( default is the sender );
'dnsbl', optionally override the configured DNSBL for this particular lookup;

You may also pass arbitary key/values. Arbitary keys should have an underscore prefix '_'.

OUTPUT EVENTS

The component will send an event in response to lookup requests. ARG0 will be a hashref containing the key/values of the original request ( including any arbitary key/values passed ).

'response', the status returned by the DNSBL, it will be NXDOMAIN if the address given was okay;
'reason', if an address is blacklisted, this may contain the reason;
'error', if something goes wrong with the DNS lookup the error string will be contained here;
'dnsbl', the DNSBL that was used for this request;

AUTHOR

Chris BinGOs Williams <chris@bingosnet.co.uk>

SEE ALSO

http://en.wikipedia.org/wiki/DNSBL

http://www.spamhaus.org/zen/

POE

POE::Component::Client::DNS