#!/usr/bin/perl -w

use strict;
use Net::PcapUtils;
use NetPacket::Ethernet qw(:strip);
use NetPacket::IP qw(:strip);
use NetPacket::TCP;

sub process_pkt {
    my($arg, $hdr, $pkt) = @_;

    my $tcp_obj = NetPacket::TCP->decode(ip_strip(eth_strip($pkt)));

    if (($tcp_obj->{src_port} == 80) or ($tcp_obj->{dest_port} == 80)) {
        print ($tcp_obj->{data});
    }
}

Net::PcapUtils::loop(\&process_pkt, FILTER => 'tcp');