public IcmpMessage(UInt32 destinationIPAddress, IcmpMessageType icmpMessageType, IcmpMessageCode icmpMessageCode, byte[] restOfHeader, byte[] data)
{
this.DestinationIPAddress = destinationIPAddress;
this.IcmpMessageType = icmpMessageType;
this.IcmpMessageCode = icmpMessageCode;
this.RestOfHeader = new byte[4];
if (restOfHeader != null)
{
Array.Copy(restOfHeader, this.RestOfHeader, System.Math.Min(this.RestOfHeader.Length, restOfHeader.Length));
}
if (data != null)
{
this.Data = data;
}
else
{
this.Data = new byte[0];
}
}
public IcmpMessage(UInt32 destinationIPAddress, IcmpMessageType icmpMessageType, IcmpMessageCode icmpMessageCode, byte[] restOfHeader, byte[] data)
{
this.DestinationIPAddress = destinationIPAddress;
this.IcmpMessageType = icmpMessageType;
this.IcmpMessageCode = icmpMessageCode;
this.RestOfHeader = new byte[4];
if (restOfHeader != null)
{
Array.Copy(restOfHeader, this.RestOfHeader, System.Math.Min(this.RestOfHeader.Length, restOfHeader.Length));
}
if (data != null)
{
this.Data = data;
}
else
{
this.Data = new byte[0];
}
}
void SendIcmpMessage(UInt32 destinationIPAddress, IcmpMessageType icmpMessageType, IcmpMessageCode icmpMessageCode, byte[] restOfHeader, byte[] data, Int64 timeoutInMachineTicks)
{
if (_isDisposed)
{
return;
}
lock (_icmpFrameBufferLock)
{
// configure ICMPv4 frame
/* Type */
_icmpFrameBuffer[0] = (byte)icmpMessageType;
/* Code (Subtype) */
_icmpFrameBuffer[1] = (byte)icmpMessageCode;
/* checksum (clear this for now; we will calculate it shortly) */
Array.Clear(_icmpFrameBuffer, 2, 2);
/* restOfHeader */
if (restOfHeader.Length < 4)
{
Array.Clear(_icmpFrameBuffer, 4, 4);
}
Array.Copy(restOfHeader, 0, _icmpFrameBuffer, 4, System.Math.Min(4, restOfHeader.Length));
UInt16 checksum;
lock (_checksumLock)
{
// calculate checksum over entire ICMP frame including data
_checksumBufferArray[0] = _icmpFrameBuffer;
_checksumOffsetArray[0] = 0;
_checksumCountArray[0] = ICMP_FRAME_BUFFER_LENGTH;
_checksumBufferArray[1] = data;
_checksumOffsetArray[1] = 0;
_checksumCountArray[1] = data.Length;
checksum = Utility.CalculateInternetChecksum(_checksumBufferArray, _checksumOffsetArray, _checksumCountArray, 2);
}
_icmpFrameBuffer[2] = (byte)((checksum >> 8) & 0xFF);
_icmpFrameBuffer[3] = (byte)(checksum & 0xFF);
_bufferArray[0] = _icmpFrameBuffer;
_indexArray[0] = 0;
_countArray[0] = ICMP_FRAME_BUFFER_LENGTH;
_bufferArray[1] = data;
_indexArray[1] = 0;
_countArray[1] = data.Length;
_ipv4Layer.Send(1 /* PROTOCOL for ICMP */, _ipv4Layer.IPAddress, destinationIPAddress, _bufferArray, _indexArray, _countArray, timeoutInMachineTicks);
}
}
void SendIcmpMessageInBackground(UInt32 destinationIPAddress, IcmpMessageType icmpMessageType, IcmpMessageCode icmpMessageCode, byte[] restOfHeader, byte[] data)
{
IcmpMessage icmpMessage = new IcmpMessage(destinationIPAddress, icmpMessageType, icmpMessageCode, restOfHeader, data);
_sendIcmpMessagesInBackgroundQueue.Enqueue(icmpMessage);
_sendIcmpMessagesInBackgroundEvent.Set();
}
internal void OnPacketReceived(UInt32 sourceIPAddress, byte[] buffer, Int32 index, Int32 count)
{
if (count < ICMP_HEADER_LENGTH)
{
return;
}
UInt16 verifyChecksum;
lock (_checksumLock)
{
// calculate checksum over entire ICMP frame including data
_checksumBufferArray[0] = buffer;
_checksumOffsetArray[0] = index;
_checksumCountArray[0] = count;
verifyChecksum = Utility.CalculateInternetChecksum(_checksumBufferArray, _checksumOffsetArray, _checksumCountArray, 1);
}
if (verifyChecksum != 0x0000)
{
return;
}
/* parse ICMP message */
/* Type */
IcmpMessageType icmpMessageType = (IcmpMessageType)buffer[index + 0];
/* Code (Subtype) */
IcmpMessageCode icmpMessageCode = (IcmpMessageCode)buffer[index + 1];
/* Rest of header */
byte[] restOfHeader = new byte[4];
Array.Copy(buffer, index + 4, restOfHeader, 0, restOfHeader.Length);
/* Data */
byte[] data = new byte[count - 8];
Array.Copy(buffer, index + 8, data, 0, data.Length);
/* process ICMP message */
switch (icmpMessageType)
{
case IcmpMessageType.Echo:
{
SendIcmpMessageInBackground(sourceIPAddress, IcmpMessageType.EchoReply, IcmpMessageCode.None, restOfHeader, data);
}
break;
//case IcmpMessageType.EchoReply:
// {
// lock (_outstandingEchoRequestsLock)
// {
// for (int i = 0; i < _outstandingEchoRequests.Count; i++)
// {
// if (_outstandingEchoRequests[i] != null)
// {
// // check to see if this request matches
// EchoRequest echoRequest = (EchoRequest)_outstandingEchoRequests[i];
// if (echoRequest.DestinationIPAddress == sourceIPAddress)
// {
// /* parse restOfHeader */
// UInt16 identifier = (UInt16)((restOfHeader[0] << 8) + restOfHeader[1]);
// UInt16 sequenceNumber = (UInt16)((restOfHeader[2] << 8) + restOfHeader[3]);
// if ((echoRequest.Identifier == identifier) && (echoRequest.SequenceNumber == sequenceNumber) && (echoRequest.Data.Length == data.Length))
// {
// bool dataMatches = true;
// for (int iData = 0; iData < data.Length; iData++)
// {
// if (data[iData] != echoRequest.Data[iData])
// {
// dataMatches = false;
// break;
// }
// }
// if (dataMatches)
// echoRequest.SetResponseReceived();
// }
// }
// }
// }
// }
// }
// break;
default:
break;
}
}
void SendIcmpMessage(UInt32 destinationIPAddress, IcmpMessageType icmpMessageType, IcmpMessageCode icmpMessageCode, byte[] restOfHeader, byte[] data, Int64 timeoutInMachineTicks)
{
if (_isDisposed) return;
lock (_icmpFrameBufferLock)
{
// configure ICMPv4 frame
/* Type */
_icmpFrameBuffer[0] = (byte)icmpMessageType;
/* Code (Subtype) */
_icmpFrameBuffer[1] = (byte)icmpMessageCode;
/* checksum (clear this for now; we will calculate it shortly) */
Array.Clear(_icmpFrameBuffer, 2, 2);
/* restOfHeader */
if (restOfHeader.Length < 4) Array.Clear(_icmpFrameBuffer, 4, 4);
Array.Copy(restOfHeader, 0, _icmpFrameBuffer, 4, System.Math.Min(4, restOfHeader.Length));
UInt16 checksum;
lock (_checksumLock)
{
// calculate checksum over entire ICMP frame including data
_checksumBufferArray[0] = _icmpFrameBuffer;
_checksumOffsetArray[0] = 0;
_checksumCountArray[0] = ICMP_FRAME_BUFFER_LENGTH;
_checksumBufferArray[1] = data;
_checksumOffsetArray[1] = 0;
_checksumCountArray[1] = data.Length;
checksum = Utility.CalculateInternetChecksum(_checksumBufferArray, _checksumOffsetArray, _checksumCountArray, 2);
}
_icmpFrameBuffer[2] = (byte)((checksum >> 8) & 0xFF);
_icmpFrameBuffer[3] = (byte)(checksum & 0xFF);
_bufferArray[0] = _icmpFrameBuffer;
_indexArray[0] = 0;
_countArray[0] = ICMP_FRAME_BUFFER_LENGTH;
_bufferArray[1] = data;
_indexArray[1] = 0;
_countArray[1] = data.Length;
_ipv4Layer.Send(1 /* PROTOCOL for ICMP */, _ipv4Layer.IPAddress, destinationIPAddress, _bufferArray, _indexArray, _countArray, timeoutInMachineTicks);
}
}
void SendIcmpMessageInBackground(UInt32 destinationIPAddress, IcmpMessageType icmpMessageType, IcmpMessageCode icmpMessageCode, byte[] restOfHeader, byte[] data)
{
IcmpMessage icmpMessage = new IcmpMessage(destinationIPAddress, icmpMessageType, icmpMessageCode, restOfHeader, data);
_sendIcmpMessagesInBackgroundQueue.Enqueue(icmpMessage);
_sendIcmpMessagesInBackgroundEvent.Set();
}
