private static void BlockPacket(ILiveDevice device, WinpkFilterHeader header, Packet packet)
{
var ip = packet.Extract <IPv4Packet>();
var tcp = packet.Extract <TcpPacket>();
if (WebHelper.Address.Equals(ip?.DestinationAddress) &&
tcp?.DestinationPort == 80)
{
// No packet shall pass
return;
}
AllowPacket(device, header, packet);
}
private static void DirtyPacket(ILiveDevice device, WinpkFilterHeader header, Packet packet)
{
var ip = packet.Extract <IPv4Packet>();
var tcp = packet.Extract <TcpPacket>();
if (WebHelper.Address.Equals(ip?.DestinationAddress) &&
tcp?.DestinationPort == 80)
{
// Let's mess with the request a bit
var data = Encoding.UTF8.GetString(tcp.PayloadData);
data = data.Replace("HTTP", "HTML");
tcp.PayloadData = Encoding.UTF8.GetBytes(data);
ip.UpdateIPChecksum();
tcp.UpdateTcpChecksum();
}
AllowPacket(device, header, packet);
}
private static void AllowPacket(ILiveDevice device, WinpkFilterHeader header, Packet packet)
{
device.SendPacket(packet.Bytes, header);
}
