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);
}
}
internal void SendTcpSegment(UInt32 sourceIPAddress, UInt32 destinationIPAddress, UInt16 sourceIPPort, UInt16 destinationIPPort, UInt32 sequenceNumber, UInt32 acknowledgementNumber, UInt16 windowSize, bool sendAck, bool sendPsh, bool sendRst, bool sendSyn, bool sendFin, TcpOption[] tcpOptions, byte[] buffer, Int32 offset, Int32 count, Int64 timeoutInMachineTicks)
{
if (_isDisposed)
{
return;
}
lock (_tcpHeaderBufferLockObject)
{
Int32 tcpHeaderLength = TCP_HEADER_MIN_LENGTH + (sendSyn ? 4 : 0);
// TCP basic header: 20 bytes
_tcpHeaderBuffer[0] = (byte)((sourceIPPort >> 8) & 0xFF);
_tcpHeaderBuffer[1] = (byte)(sourceIPPort & 0xFF);
_tcpHeaderBuffer[2] = (byte)((destinationIPPort >> 8) & 0xFF);
_tcpHeaderBuffer[3] = (byte)(destinationIPPort & 0xFF);
// sequence number
_tcpHeaderBuffer[4] = (byte)((sequenceNumber >> 24) & 0xFF);
_tcpHeaderBuffer[5] = (byte)((sequenceNumber >> 16) & 0xFF);
_tcpHeaderBuffer[6] = (byte)((sequenceNumber >> 8) & 0xFF);
_tcpHeaderBuffer[7] = (byte)(sequenceNumber & 0xFF);
// acknowledment number
if (sendAck)
{
_tcpHeaderBuffer[8] = (byte)((acknowledgementNumber >> 24) & 0xFF);
_tcpHeaderBuffer[9] = (byte)((acknowledgementNumber >> 16) & 0xFF);
_tcpHeaderBuffer[10] = (byte)((acknowledgementNumber >> 8) & 0xFF);
_tcpHeaderBuffer[11] = (byte)(acknowledgementNumber & 0xFF);
}
else
{
Array.Clear(_tcpHeaderBuffer, 8, 4);
}
// header length and flags
_tcpHeaderBuffer[12] = (byte)((tcpHeaderLength / 4) << 4);
// more flags
_tcpHeaderBuffer[13] = (byte)(
(sendFin ? 1 << 0 : 0) |
(sendSyn ? 1 << 1 : 0) |
(sendRst ? 1 << 2 : 0) |
(sendPsh ? 1 << 3 : 0) |
(sendAck ? 1 << 4 : 0)
);
// window size (i.e. how much data we are willing to receive)
_tcpHeaderBuffer[14] = (byte)((windowSize >> 8) & 0xFF);
_tcpHeaderBuffer[15] = (byte)(windowSize & 0xFF);
// tcp checksum
Array.Clear(_tcpHeaderBuffer, 16, 2);
// urgent pointer
/* NOTE: bytes 18-19, never populated */
// TCP options: empty by default policy -- but zero-initialized under any circumstance
Array.Clear(_tcpHeaderBuffer, TCP_HEADER_MIN_LENGTH, TCP_HEADER_MAX_LENGTH - TCP_HEADER_MIN_LENGTH);
/* TCP options */
if (tcpOptions != null)
{
int headerPos = TCP_HEADER_MIN_LENGTH;
for (int iOption = 0; iOption < tcpOptions.Length; iOption++)
{
_tcpHeaderBuffer[headerPos++] = tcpOptions[iOption].Kind;
switch (tcpOptions[iOption].Kind)
{
case 0: /* EOL = End of Option List */
case 1: /* NOP = No OPeration; used for padding */
break;
default:
{
if (tcpOptions[iOption].Data != null)
{
_tcpHeaderBuffer[headerPos++] = (byte)(tcpOptions[iOption].Data.Length + 2);
Array.Copy(tcpOptions[iOption].Data, 0, _tcpHeaderBuffer, headerPos, tcpOptions[iOption].Data.Length);
headerPos += tcpOptions[iOption].Data.Length;
}
else
{
_tcpHeaderBuffer[headerPos++] = 2; /* only 2 bytes--the kind and the length--with no data */
}
}
break;
}
}
}
UInt16 checksum;
lock (_tcpPseudoHeaderBufferLockObject)
{
// create temporary pseudo header
_tcpPseudoHeaderBuffer[0] = (byte)((sourceIPAddress >> 24) & 0xFF);
_tcpPseudoHeaderBuffer[1] = (byte)((sourceIPAddress >> 16) & 0xFF);
_tcpPseudoHeaderBuffer[2] = (byte)((sourceIPAddress >> 8) & 0xFF);
_tcpPseudoHeaderBuffer[3] = (byte)(sourceIPAddress & 0xFF);
_tcpPseudoHeaderBuffer[4] = (byte)((destinationIPAddress >> 24) & 0xFF);
_tcpPseudoHeaderBuffer[5] = (byte)((destinationIPAddress >> 16) & 0xFF);
_tcpPseudoHeaderBuffer[6] = (byte)((destinationIPAddress >> 8) & 0xFF);
_tcpPseudoHeaderBuffer[7] = (byte)(destinationIPAddress & 0xFF);
_tcpPseudoHeaderBuffer[8] = 0; // ZERO
_tcpPseudoHeaderBuffer[9] = (byte)IPv4Layer.ProtocolType.Tcp; // Protocol Number
UInt16 tcpLength = (UInt16)(tcpHeaderLength + count);
_tcpPseudoHeaderBuffer[10] = (byte)((tcpLength >> 8) & 0xFF);
_tcpPseudoHeaderBuffer[11] = (byte)(tcpLength & 0xFF);
// calculate checksum over entire pseudo-header, UDP header and data
_checksumBufferArray[0] = _tcpPseudoHeaderBuffer;
_checksumOffsetArray[0] = 0;
_checksumCountArray[0] = TCP_PSEUDO_HEADER_LENGTH;
_checksumBufferArray[1] = _tcpHeaderBuffer;
_checksumOffsetArray[1] = 0;
_checksumCountArray[1] = tcpHeaderLength;
_checksumBufferArray[2] = buffer;
_checksumOffsetArray[2] = offset;
_checksumCountArray[2] = count;
checksum = Utility.CalculateInternetChecksum(_checksumBufferArray, _checksumOffsetArray, _checksumCountArray); /* NOTE: this function will append a pad byte if necessary for 16-bit alignment before calculation */
}
// insert checksujm into UDP header
_tcpHeaderBuffer[16] = (byte)((checksum >> 8) & 0xFF);
_tcpHeaderBuffer[17] = (byte)(checksum & 0xFF);
// queue up our buffer arrays
_bufferArray[0] = _tcpHeaderBuffer;
_indexArray[0] = 0;
_countArray[0] = tcpHeaderLength;
_bufferArray[1] = buffer;
_indexArray[1] = offset;
_countArray[1] = count;
/* TODO: deal with our flags and timeout_ms; we shouldn't just be sending while blocking -- and ignoring the flags */
_ipv4Layer.Send((byte)IPv4Layer.ProtocolType.Tcp, sourceIPAddress, destinationIPAddress, _bufferArray, _indexArray, _countArray, timeoutInMachineTicks);
}
}
/* TODO: we can't lock permanently while waiting for another UDP packet to be sent; get rid of the _udpHeaderBufferLock "lock that could stay locked forever" */
public override Int32 SendTo(byte[] buffer, Int32 offset, Int32 count, Int32 flags, Int64 timeoutInMachineTicks, UInt32 ipAddress, UInt16 ipPort)
{
if (!_sourceIpAddressAndPortAssigned)
{
Bind(IP_ADDRESS_ANY, IP_PORT_ANY);
}
lock (_udpHeaderBufferLockObject)
{
// UDP header: 8 bytes
_udpHeaderBuffer[0] = (byte)((_srcIPPort >> 8) & 0xFF);
_udpHeaderBuffer[1] = (byte)(_srcIPPort & 0xFF);
_udpHeaderBuffer[2] = (byte)((ipPort >> 8) & 0xFF);
_udpHeaderBuffer[3] = (byte)(ipPort & 0xFF);
UInt16 udpLength = (UInt16)(UDP_HEADER_LENGTH + count);
_udpHeaderBuffer[4] = (byte)((udpLength >> 8) & 0xFF);
_udpHeaderBuffer[5] = (byte)(udpLength & 0xFF);
_udpHeaderBuffer[6] = 0; // for now, no checksum; we'll populate this when we calculate checksum over the pseudoheader + header + data + 16-bit-alignment-if-necessary-zero-pad-byte
_udpHeaderBuffer[7] = 0; // checksum (continued)
UInt16 checksum;
lock (_udpPseudoHeaderBufferLockObject)
{
// create temporary pseudo header
_udpPseudoHeaderBuffer[0] = (byte)((_srcIPAddress >> 24) & 0xFF);
_udpPseudoHeaderBuffer[1] = (byte)((_srcIPAddress >> 16) & 0xFF);
_udpPseudoHeaderBuffer[2] = (byte)((_srcIPAddress >> 8) & 0xFF);
_udpPseudoHeaderBuffer[3] = (byte)(_srcIPAddress & 0xFF);
_udpPseudoHeaderBuffer[4] = (byte)((ipAddress >> 24) & 0xFF);
_udpPseudoHeaderBuffer[5] = (byte)((ipAddress >> 16) & 0xFF);
_udpPseudoHeaderBuffer[6] = (byte)((ipAddress >> 8) & 0xFF);
_udpPseudoHeaderBuffer[7] = (byte)(ipAddress & 0xFF);
_udpPseudoHeaderBuffer[8] = 0; // ZERO
_udpPseudoHeaderBuffer[9] = (byte)IPv4Layer.ProtocolType.Udp; // Protocol Number
_udpPseudoHeaderBuffer[10] = (byte)((udpLength >> 8) & 0xFF);
_udpPseudoHeaderBuffer[11] = (byte)(udpLength & 0xFF);
// calculate checksum over entire pseudo-header, UDP header and data
_checksumBufferArray[0] = _udpPseudoHeaderBuffer;
_checksumOffsetArray[0] = 0;
_checksumCountArray[0] = UDP_PSEUDO_HEADER_LENGTH;
_checksumBufferArray[1] = _udpHeaderBuffer;
_checksumOffsetArray[1] = 0;
_checksumCountArray[1] = UDP_HEADER_LENGTH;
_checksumBufferArray[2] = buffer;
_checksumOffsetArray[2] = offset;
_checksumCountArray[2] = count;
checksum = Utility.CalculateInternetChecksum(_checksumBufferArray, _checksumOffsetArray, _checksumCountArray); /* NOTE: this function will append a pad byte if necessary for 16-bit alignment before calculation */
}
// insert checksujm into UDP header
_udpHeaderBuffer[6] = (byte)((checksum >> 8) & 0xFF);
_udpHeaderBuffer[7] = (byte)(checksum & 0xFF);
// queue up our buffer arrays
_bufferArray[0] = _udpHeaderBuffer;
_indexArray[0] = 0;
_countArray[0] = UDP_HEADER_LENGTH;
_bufferArray[1] = buffer;
_indexArray[1] = offset;
_countArray[1] = count;
/* TODO: deal with our flags and timeout_ms; we shouldn't just be sending while blocking -- and ignoring the flags */
_ipv4Layer.Send((byte)IPv4Layer.ProtocolType.Udp, _srcIPAddress, ipAddress, _bufferArray, _indexArray, _countArray, timeoutInMachineTicks);
}
/* TODO: return actual # of bytes sent, if different; this may be caused by a limit on UDP datagram size, timeout while sending data, etc. */
return(count);
}
