File Coverage

blib/lib/Mail/SPF/Mech/MX.pm

Criterion	Covered	Total	%
statement	22	42	52.3
branch	0	14	0.0
condition	0	6	0.0
subroutine	7	10	70.0
pod	2	3	66.6
total	31	75	41.3

#
# Mail::SPF::Mech::MX
# SPF record "mx" mechanism class.
#
# (C) 2005-2012 Julian Mehnle
#     2005      Shevek
# $Id: MX.pm 57 2012-01-30 08:15:31Z julian $
#
##############################################################################

package Mail::SPF::Mech::MX;

=head1 NAME

Mail::SPF::Mech::MX - SPF record C mechanism class

=head1 VERSION

version 3.20250505

=cut

use warnings;
use strict;

use base 'Mail::SPF::SenderIPAddrMech';

use constant TRUE   => (0 == 0);
use constant FALSE  => not TRUE;

use constant name           => 'mx';
use constant name_pattern   => qr/${\name}/i;

=head1 DESCRIPTION

An object of class B represents an SPF record mechanism of
type C.

=head2 Constructors

The following constructors are provided:

=over

=item B: returns I

Creates a new SPF record C mechanism object.

%options is a list of key/value pairs representing any of the following
options:

=over

=item B

=item B

=item B

=item B

See L.

=back

=item B: returns I;
throws I, I

Creates a new SPF record C mechanism object by parsing the string and
any options given.

=back

=head2 Class methods

The following class methods are provided:

=over

=item B

=item B

=item B

=item B

See L.

=item B: returns I

Returns B<'mx'>.

=item B: returns I

Returns a regular expression that matches a mechanism name of B<'mx'>.

=back

=head2 Instance methods

The following instance methods are provided:

=over

=cut

sub parse_params {
    my ($self) = @_;
    $self->parse_domain_spec();
    $self->parse_ipv4_ipv6_prefix_lengths();
    return;
}

=item B

=item B

=item B

=cut

sub params {
    my ($self) = @_;
    my $params;
    $params .= ':' . $self->{domain_spec}
        if  defined($self->{domain_spec});
    $params .= '/' . $self->{ipv4_prefix_length}
        if  defined($self->{ipv4_prefix_length})
        and $self->{ipv4_prefix_length} != $self->default_ipv4_prefix_length;
    $params .= '//' . $self->{ipv6_prefix_length}
        if  defined($self->{ipv6_prefix_length})
        and $self->{ipv6_prefix_length} != $self->default_ipv6_prefix_length;
    return $params;
}

=item B

=item B

=item B

See L.

=item B: returns I

Returns the C parameter of the mechanism.

=item B: returns I

Returns the IPv4 network prefix length of the mechanism.

=item B: returns I

Returns the IPv6 network prefix length of the mechanism.

=cut

# Make read-only accessors:
__PACKAGE__->make_accessor($_, TRUE)
    foreach qw(domain_spec ipv4_prefix_length ipv6_prefix_length);

=item B: returns I

Checks whether any MX hosts of the mechanism's target domain name (that is, any
of the host addresses of its DNS C records) matches the given request's IP
address (see L), and returns B if it does,
or B otherwise.  The mechanism's IP network prefix lengths are respected
when matching address records against the request's IP address.  See RFC 4408,
5 and 5.4, for the exact algorithm used.

=cut

sub match {
    my ($self, $server, $request) = @_;

    $server->count_dns_interactive_term($request);

    my $target_domain = $self->domain($server, $request);
    my $mx_packet     = $server->dns_lookup($target_domain, 'MX');
    my @mx_rrs        = $mx_packet->answer
        or $server->count_void_dns_lookup($request);

    # Respect the MX mechanism lookups limit (RFC 4408, 5.4/3/4):
    @mx_rrs = splice(@mx_rrs, 0, $server->max_name_lookups_per_mx_mech)
        if defined($server->max_name_lookups_per_mx_mech);

    # TODO Use A records from packet's "additional" section?  Probably not.

    # Check MX records:
    foreach my $rr (@mx_rrs) {
        if ($rr->type eq 'MX') {
            return TRUE
                if $self->match_in_domain($server, $request, $rr->exchange);
        }
        else {
            # Unexpected RR type.
            # TODO Generate debug info or ignore silently.
        }
    }

    return FALSE;
}

=back

=head1 SEE ALSO

L, L, L, L

L

For availability, support, and license information, see the README file
included with Mail::SPF.

=head1 AUTHORS

Julian Mehnle , Shevek

=cut

TRUE;