Modifying Packets

IPQueue allows us to specify a modified packet with a verdict
If specified, it replaces the original packet
Replace all occurrences of "FOO" with "BAR":

    my $tcp = NetPacket::TCP->decode($ip->{data});

    $tcp->{data} =~ s/FOO/BAR/g;
    $ip->{data} = $tcp->encode($ip);
    my $raw = $ip->encode;

    $ipq->set_verdict($msg->packet_id, NF_ACCEPT, length($raw), $raw);