NAME

Mailmunge::Test::GetMX - Get the MX records for a domain and classify them

ABSTRACT

This class performs an MX lookup on a given domain and returns the IPv4 addresses of the MX hosts, classifying each IP address as described below.

Mailmunge::Test::GetMX is a subclass of Mailmunge::Test.

SYNOPSIS

use Mailmunge::Test::GetMX;

sub filter_sender {
    my ($self, $ctx) = @_;
    my $getmx = Mailmunge::Test::GetMX->new($self);
    my $results = $getmx->get_mx_hosts($ctx->sender);
    if (scalar(@{$results->{bogus}}) {
        $self->log($ctx, 'info', "Found reserved IPs in MX for " . $ctx->sender);
    }
    if (scalar(@{$results->{private}}) {
        $self->log($ctx, 'info', "Found RFC 1918 IPs in MX for " . $ctx->sender);
    }
    if (scalar(@{$results->{loopback}}) {
        $self->log($ctx, 'info', "Found RFC loopback IPs in MX for " . $ctx->sender);
    }
    if (scalar(@{$results->{routable}}) {
        $self->log($ctx, 'info', "Found valid routable IPs in MX for " . $ctx->sender);
    }
}

CONSTRUCTOR

Mailmunge::Test::GetMX->new($filter)

Constructs and returns a new Mailmunge::Test::GetMX object.

get_mx_hosts($domain_or_sender)

Given a domain or an email address, looks up the MX hosts of the domain (or domain of the sender) and returns a hash containing the following four elements:

bogus: An arrayref of MX hosts IPs that have bogus unroutable IP addresses (such as 0.0.0.0, 255.255.255.255, or multicast addresses, for example.)
private: An arrayref of MX host IPs that are in the RFC 1918 private use ranges.
loopback: An arrayref of MX host IPs that are in the range 127.0.0.0/8.
routable: An arrayref of MX host IPs that are globally-routable unicast IPv4 addresses.

You may wish to have your filter reject mail from domains that have bogus MX records; make your decision based on the value returned from get_mx_hosts.

ip4_is_loopback($ip)

Given the string representation of an IPv4 address, returns true if it's in the range 127.0.0.0/8 or false otherwise.

ip4_is_private($ip)

Given the string representation of an IPv4 address, returns true if it's in one of the RFC 1918 private ranges or false otherwise.

ip4_is_reserved($ip)

Given the string representation of an IPv4 address, returns true if it's in one of the following ranges:

Link-local: 169.254.0.0/16
IPv4 Multicast: 224.0.0.0/4
Class E: 240.0.0.0/4
Bogus: 0.0.0.0/32 and 255.255.255.255/32

AUTHOR

Dianne Skoll <dianne@skollsoft.com>

LICENSE

This code is licensed under the terms of the GNU General Public License, version 2.