/// <summary>
/// Creates UDP datagram based on the specified IP packet.
/// </summary>
/// <param name="ipPacket">A source IpPacket Object that contains a UDP datagram.</param>
/// <param name="reuseOriginalBuffer">A flag that determines if the original packet's buffer needs to be reused.</param>
/// <returns>A new UdpDatagram instance.</returns>
/// <exception cref="System.ArgumentNullException">ipPacket is null</exception>
/// <exception cref="System.NotSupportedException">Only UDP packets are supported.</exception>
/// <exception cref="System.ArgumentOutOfRangeException">ipPacket.PacketData is empty.</exception>
public static UdpDatagram ToUdpDatagram(this IIpPacket ipPacket, bool reuseOriginalBuffer = true)
{
if (ipPacket == null)
{
throw new ArgumentNullException("ipPacket");
}
if (ipPacket.ProtocolType != ProtocolType.Udp)
{
throw new NotSupportedException("Only UDP packets are supported.");
}
if (ipPacket.PacketData.Count <= 0)
{
throw new ArgumentOutOfRangeException();
}
var packetData = ipPacket.PacketData.AsByteArraySegment();
UdpDatagramHeader udpDatagramHeader = null;
if (ipPacket.PacketData.Count > 8)
{
udpDatagramHeader = new UdpDatagramHeader(
packetData.Array.ReadNetOrderUShort(packetData.Offset),
packetData.Array.ReadNetOrderUShort(2 + packetData.Offset),
packetData.Array.ReadNetOrderUShort(4 + packetData.Offset),
packetData.Array.ReadNetOrderUShort(6 + packetData.Offset));
}
ArraySegment <byte> udpData;
if (reuseOriginalBuffer)
{
udpData = new ArraySegment <byte>(
packetData.Array,
packetData.Offset + 8,
packetData.Count - 8);
}
else
{
var ipOptionsDataArray = new byte[packetData.Count - 8];
Array.Copy(packetData.Array, packetData.Offset + 8, ipOptionsDataArray, 0, packetData.Count - 8);
udpData = new ArraySegment <byte>(ipOptionsDataArray);
}
var udpDatagram = new UdpDatagram
{
PacketHeader = ipPacket.PacketHeader,
UdpDatagramHeader = udpDatagramHeader,
UdpData = udpData,
ReceivedTime = ipPacket.ReceivedTime
};
return(udpDatagram);
}
/// <summary>
/// Creates UDP datagram based on the specified IP packet.
/// </summary>
/// <param name="ipPacket">A source IpPacket Object that contains a UDP datagram.</param>
/// <param name="reuseOriginalBuffer">A flag that determines if the original packet's buffer needs to be reused.</param>
/// <returns>A new UdpDatagram instance.</returns>
/// <exception cref="System.ArgumentNullException">ipPacket is null</exception>
/// <exception cref="System.NotSupportedException">Only UDP packets are supported.</exception>
/// <exception cref="System.ArgumentOutOfRangeException">ipPacket.PacketData is empty.</exception>
public static UdpDatagram ToUdpDatagram(this IIpPacket ipPacket, bool reuseOriginalBuffer = true)
{
if (ipPacket == null)
{
throw new ArgumentNullException("ipPacket");
}
if (ipPacket.ProtocolType != ProtocolType.Udp)
{
throw new NotSupportedException("Only UDP packets are supported.");
}
if (ipPacket.PacketData.Count <= 0)
{
throw new ArgumentOutOfRangeException();
}
var packetData = ipPacket.PacketData.AsByteArraySegment();
UdpDatagramHeader udpDatagramHeader = null;
if (ipPacket.PacketData.Count > 8)
{
udpDatagramHeader = new UdpDatagramHeader(
packetData.Array.ReadNetOrderUShort(packetData.Offset),
packetData.Array.ReadNetOrderUShort(2 + packetData.Offset),
packetData.Array.ReadNetOrderUShort(4 + packetData.Offset),
packetData.Array.ReadNetOrderUShort(6 + packetData.Offset));
}
ArraySegment<byte> udpData;
if (reuseOriginalBuffer)
{
udpData = new ArraySegment<byte>(
packetData.Array,
packetData.Offset + 8,
packetData.Count - 8);
}
else
{
var ipOptionsDataArray = new byte[packetData.Count - 8];
Array.Copy(packetData.Array, packetData.Offset + 8, ipOptionsDataArray, 0, packetData.Count - 8);
udpData = new ArraySegment<byte>(ipOptionsDataArray);
}
var udpDatagram = new UdpDatagram
{
PacketHeader = ipPacket.PacketHeader,
UdpDatagramHeader = udpDatagramHeader,
UdpData = udpData,
ReceivedTime = ipPacket.ReceivedTime
};
return udpDatagram;
}
