/// <summary>Sends data as an UDP datagram from a spoofed port.</summary>
/// <param name="spoofedEndPoint">The spoofed local endpoint.</param>
/// <param name="remoteEndPoint">The remote endpoint.</param>
/// <param name="data">An array that contains the data to send.</param>
public static unsafe void Send(IPEndPoint spoofedEndPoint, IPEndPoint remoteEndPoint, byte[] data)
{
UDPHeader header = new UDPHeader(spoofedEndPoint.Address, remoteEndPoint.Address, (ushort)spoofedEndPoint.Port, (ushort)remoteEndPoint.Port, data.Length);
// compute IP header checksum
uint sum = 0;
for (int i = 0; i < 10; ++i)
{
sum += header.IPHeader.Words[i];
}
while ((sum >> 16) != 0)
{
sum = (sum & 0xffff) + (sum >> 16);
}
header.IPHeader.HeaderChecksum = (ushort)~sum;
// compute UDP checksum
sum = 0;
PseudoHeader pseudoHeader = new PseudoHeader(header);
for (int i = 0; i < 10; ++i)
{
sum += pseudoHeader.Words[i];
fixed(byte *dataPtr = data)
{
for (int i = 0; i < data.Length / 2; ++i)
{
sum += ((ushort *)dataPtr)[i];
}
}
if (data.Length % 2 == 1)
{
sum += data[data.Length - 1];
}
while ((sum >> 16) != 0)
{
sum = (sum & 0xffff) + (sum >> 16);
}
header.Checksum = (ushort)~sum;
// copy header and data into datagram
byte[] datagram = new byte[data.Length + sizeof(UDPHeader)];
for (int i = 0; i < sizeof(UDPHeader); ++i)
{
datagram[i] = ((byte *)&header)[i];
}
for (int i = 0; i < data.Length; ++i)
datagram[i + sizeof(UDPHeader)] = data[i]; }
// send datagram
using (Socket rawSocket = new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.Raw)) {
rawSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.HeaderIncluded, true);
rawSocket.SendTo(datagram, remoteEndPoint);
}
}
public IPpacket(ushort IPLength, PacketType type)
{
IPHeaderLength = IPLength;
packetType = type;
pseudoheader = new PseudoHeader();
}
public IPpacket(ushort IPLength, PacketType type)
{
IPHeaderLength = IPLength;
packetType = type;
pseudoheader = new PseudoHeader();
}