#!/usr/bin/perl 
use strict;
use warnings;

use Data::Dumper;
use Getopt::Long;
use Pod::Usage;
$Data::Dumper::Sortkeys = 1;
$Data::Dumper::Quotekeys = 0;

use lib 'lib';
use Mail::DMARC::PurePerl;

my %command_line_options = (
        'domain:s'  => \my $domain,
        'verbose'   => \my $verbose,
        );
GetOptions (%command_line_options);
$verbose = 1 if ! defined $verbose;

$domain ||= $ARGV[0];
$domain or pod2usage;

my $dmarc = Mail::DMARC::PurePerl->new;
$dmarc->verbose($verbose);
$dmarc->header_from($domain);
my $policy = $dmarc->discover_policy() or
    die "no DMARC policy published for $domain\n";

print Dumper( $policy );
if ( $policy->rua ) {
    print "\n";
    my $uri_count = $dmarc->has_valid_reporting_uri( $policy->rua );
    print "valid report URI: ";
    print $uri_count ? "yes\n" : "no\n";
};

exit;

__END__

=pod

=head1 NAME

dmarc_lookup - look up DMARC policy for a domain

=head1 SYNOPSIS

   dmarc_lookup example.com [ --verbose ]

=head1 DESCRIPTION

Query the DNS for a DMARC policy for a (sub)domain. Displays any found results as the DNS record as a perl object. In the simplest case, where the domain name in the email From header matches the I<Organizational Domain>, this is roughly equivalent to the following commands:

    dig +short _dmarc.example.com TXT

    print $_->txtdata."\n"
      for Net::DNS::Resolver->new(dnsrch=>0)->send('_dmarc.example.com','TXT')->answer;

When the domain name in the email From header (header_from) is not an Organizational Domain (ex: www.example.com), an attempt is made to determine the O.D. using the Mozilla Public Suffix List. When the O.D. differs from the header_from, a second DNS query is sent to _dmarc.[O.D.]. 

=head1 EXAMPLES

A DMARC record in DNS format looks like this:

v=DMARC1; p=reject; adkim=s; aspf=s; rua=mailto:[email protected]; pct=100;

DMARC records are stored as TXT resource records in the DNS, at _dmarc.example.com.

Other ways to retrieve a DMARC record for a domain are:

=head1 SEE ALSO

L<Mail::DMARC::Policy>

=head1 AUTHORS

=over 4

=item *

Matt Simerson <[email protected]>

=item *

Davide Migliavacca <[email protected]>

=item *

Marc Bradshaw <[email protected]>

=back

=cut