/// <summary>
/// Constructor
/// </summary>
/// <param name="interfaceAddress">The MAC address of the interface to receive the data on</param>
public LLCSocket(PhysicalAddress interfaceAddress)
{
SocketHandle = socket(EAddressFamily.LLC, ESocketType.Datagram, EProtocol.Null);
if (SocketHandle < 0)
{
throw new Exception("Failed to create socket for the LLC protocol family. Either permissions or missing kernel module (llc2.o)");
}
//Console.WriteLine("Socket called " + SocketHandle.ToString());
var socketAddress = new SocketAddressLLC
{
sllc_family = EAddressFamily.LLC,
sllc_arphrd = EAddressFamily.EthernetHardwareAddress,
sllc_sap = (byte)ESapType.SNAP,
};
socketAddress.MacAddress = interfaceAddress;
var result = bind(SocketHandle, ref socketAddress, (IntPtr)16);
if (result < 0)
{
throw new Exception("Error binding the socket to the LLC/SNAP protocol. Either permissions or missing module (llc2.o).");
}
//Console.WriteLine("Bind called " + result.ToString());
}
/// <summary>
/// Receive data from the remote host. This uses a fixed size buffer of 2000 bytes which should be safe for 802.2 packets.
/// </summary>
/// <param name="remoteHost">Return value of the remote host the the frame was received from</param>
/// <returns>The buffer received from the remote host</returns>
public byte [] ReceiveFrom(out PhysicalAddress remoteHost)
{
var buffer = new byte[2000];
var destinationAddress = new SocketAddressLLC();
IntPtr addressLength = (IntPtr)16;
var result = recvfrom(SocketHandle, buffer, (IntPtr)2000, 0, ref destinationAddress, ref addressLength);
//Console.WriteLine("recvfrom called " + result.ToString());
if ((long)result <= 0)
{
remoteHost = null;
return(null);
}
// TODO : Use map instead
remoteHost = destinationAddress.MacAddress;
return(buffer.Take((int)result).ToArray());
}
private static extern IntPtr recvfrom(int sockfd, byte [] buf, IntPtr len, int flags, ref SocketAddressLLC src_addr, ref IntPtr addrlen);
private static extern int bind(int fd, ref SocketAddressLLC address, IntPtr addressLength);
