Net::Pcap does the job, but it's confusing and difficult to operate.  This
module solves that problem in a relatively general way.

I wanted a way to build libpcap filters really quickly.  It shouldn't take two
hours to crank one out, particularly since I imagine they all kinda look the
same.  So, I wrote this to simplify writing sniffers really quickly.

use strict;
use warnings;
use Net::Pcap::Easy;

my $npe = Net::Pcap::Easy->new(
    dev              => "lo",
    filter           => "host 127.0.0.1 and icmp",
    packets_per_loop => 10,
    bytes_to_capture => 1024,

    icmp_callback => sub {
        my ($npe, $ether, $ip, $icmp) = @_;

        print "ICMP: $ether->{src_mac}:$ip->{src_ip} -> $ether->{dest_mac}:$ip->{dest_ip}\n";
    },
);

1 while $npe->loop;