private static void ProcessTzspPacket(byte[] packet, ushort listenPort)
{
// TZSP header
// version (1) == 1
// type (1) == 0
// protocol (2) == 1
// tags (N)
// type (1) == anything, but 1 means no more tags (not even the rest of the fields of this tag)
// length (1)
// data (N)
// packetdata (...)
// Ethernet MAC header (14)
// IP header
// +0 version (0.5)
// +0.5 header length / 4 (0.5)
// +2 total length (2)
// +9 protocol (1)
// +12 source address (4)
// +16 destination address (4)
// ...options...
// inner packet
using var stream = new MemoryStream(packet);
using var reader = new MultiEndianBinaryReader(stream, ByteOrder.BigEndian);
var tzspVersion = reader.ReadByte();
if (tzspVersion != 1)
{
throw new NotSupportedException("TZSP version != 1");
}
var tzspType = reader.ReadByte();
if (tzspType != 0)
{
throw new NotSupportedException("TZSP type != 0");
}
var tzspProtocol = reader.ReadUInt16();
if (tzspProtocol != 1)
{
throw new NotSupportedException("TZSP protocol != 1");
}
while (true)
{
var tagType = reader.ReadByte();
if (tagType == 1)
{
break;
}
var tagLength = reader.ReadByte();
stream.Position += tagLength; // Skip the tag.
}
stream.Position += 14; // Skip MAC header
var firstByte = reader.ReadByte();
var ipVersion = (firstByte & 0xF0) >> 4;
if (ipVersion != 4)
{
return; // We only support IPv4
}
var headerLength = (firstByte & 0x0F) * 4;
var positionAfterIpHeader = stream.Position - 1 + headerLength;
stream.Position += 1; // Skip to total length.
// Captured packet, ignoring any TZSP layers.
var totalPacketLengthIncludingIpHeader = reader.ReadUInt16();
stream.Position += 5; // Skip to protocol.
var protocol = reader.ReadByte();
stream.Position += 2; // Skip to source address.
var sourceAddress = new IPAddress(reader.ReadBytesAndVerify(4));
var destinationAddress = new IPAddress(reader.ReadBytesAndVerify(4));
var sourceAddressString = sourceAddress.ToString();
var destinationAddressString = destinationAddress.ToString();
string sourceAddressType = DetermineIPv4AddressType(sourceAddress);
string destinationAddressType = DetermineIPv4AddressType(destinationAddress);
stream.Position = positionAfterIpHeader;
int?sourcePort = null;
int?destinationPort = null;
if (protocol == 17 || protocol == 6)
{
// If UDP or TCP, source and destination port are next fields.
sourcePort = reader.ReadUInt16();
destinationPort = reader.ReadUInt16();
}
else
{
// unknown protocol
}
string protocolName = "unknown";
if (Enum.IsDefined(typeof(ProtocolType), (int)protocol))
{
protocolName = ((ProtocolType)protocol).ToString().ToLowerInvariant();
}
BytesBase.WithLabels(sourceAddressString, sourceAddressType, destinationAddressString, destinationAddressType, protocolName, listenPort.ToString()).Inc(totalPacketLengthIncludingIpHeader);
PacketsBase.WithLabels(sourceAddressString, sourceAddressType, destinationAddressString, destinationAddressType, protocolName, listenPort.ToString()).Inc();
}
public void sendPacket(PacketsBase packet)
{
}
