/// <summary>
/// WSASend Hook. Use this to modify any particular outgoing data, or use
/// outgoing data to modify internal structures (e.g. parse world update
/// sends and use parsed data to change NPC locations, block types, etc.
///
/// NOTES: Buffer is a ref to an WSABuffer structure. To access packet data, it
/// needs to be marshalled. Marshal.Copy(Buffer.buf, newbuffer, number_of_bytes)
/// is the safest way. number_of_bytes in WSASend calls is stored in Buffer.len,
/// as a plain int.
/// </summary>
/// <param name="socketHandle">The socket handle.</param>
/// <param name="Buffer">The buffer pointer.</param>
/// <param name="BufferCount">The buffer count.</param>
/// <param name="bytesTransferred">The bytes transferred POST SEND.</param>
/// <param name="socketFlags">The socket flags.</param>
/// <param name="overlapped">The overlapped data.</param>
/// <param name="completionRoutine">The completion routine after overlap processing.</param>
/// <returns></returns>
static int WSASendHooked(
[In] IntPtr socketHandle,
[In] ref WSABuffer Buffer,
[In] int BufferCount,
[In] IntPtr bytesTransferred,
[In] SocketFlags socketFlags,
[In] IntPtr overlapped,
[In] IntPtr completionRoutine)
{
//var newBuffer = new byte[Buffer.len]; //buffer to hold sent bytes
//Marshal.Copy(Buffer.buf,newBuffer,0,Buffer.len);
/*if (newBuffer[4] == 0x19)
* {
* var n = Commands.ProcessData(newBuffer, 1);
* if (n.Length == -1)
* {
* return 0;
* }
* int i = 0;
* foreach (byte b in n.Data)
* {
* Marshal.WriteByte(Buffer.buf, i, b);
* i++;
* }
*
* Buffer.len = n.Length;
* }*/
//call WSASend
return(WSASend(socketHandle, ref Buffer, BufferCount, bytesTransferred, socketFlags, overlapped,
completionRoutine));
}
static extern int WSASend(
[In] IntPtr socketHandle,
[In] ref WSABuffer Buffer,
[In] int BufferCount,
[In] IntPtr bytesTransferred,
[In] SocketFlags socketFlags,
[In] IntPtr overlapped,
[In] IntPtr completionRoutine
);
/// <summary>
/// WSARecv Hook. Use this hook to modify incoming data, keeping length intact.
/// Any changes to length apparently will cause a socket fault (unraised), though
/// actual cause is unknown. It should be safe to rewrite incoming data and marshal
/// it back to the original pointer, through Marshal.WriteByte(Buffer.buf, index);
///
/// There are possibly ways to modify packet data to be inert, if reducing a recieved
/// packet to a stub is necessary.
///
/// NOTES: Buffer is a ref to an WSABuffer structure. To access packet data, it needs
/// to be marshalled. Marshal.Copy(Buffer.buf, newbuffer, number_of_bytes) is the
/// safest way. number_of_bytes can be retrieved by marshalling bytesTransferred to
/// an Int32 type with Marshal.ReadInt32(bytesTransferred).
/// </summary>
/// <param name="socketHandle">The socket handle.</param>
/// <param name="Buffer">The buffer pointer.</param>
/// <param name="BufferCount">The buffer count.</param>
/// <param name="bytesTransferred">The bytes transferred.</param>
/// <param name="socketFlags">The socket flags.</param>
/// <param name="overlapped">The overlapped data.</param>
/// <param name="completionRoutine">The completion routine after overlap processing.</param>
/// <returns></returns>
static int WSARecvHooked(
[In] IntPtr socketHandle,
[In, Out] ref WSABuffer Buffer,
[In] int BufferCount,
[In, Out] IntPtr bytesTransferred,
[In, Out] ref SocketFlags socketFlags,
[In] IntPtr overlapped,
[In] IntPtr completionRoutine)
{
var result = WSARecv(socketHandle, ref Buffer, BufferCount, bytesTransferred, ref socketFlags,
overlapped, completionRoutine);
if (result != 0)
{
Console.WriteLine("Socket Error!\n");
#if DEBUG
Console.WriteLine("WSARecv (original) returned errorno: " + result);
#endif
return(result);
}
int bytes = Marshal.ReadInt32(bytesTransferred);
if (bytes > 0)
{
var newBuffer = new byte[bytes];
Marshal.Copy(Buffer.buf, newBuffer, 0, bytes);
//wrap ProcessData call, so an exception in it shouldn't cause
//easyhook to detach.
try
{
var packet = Commands.ProcessData(newBuffer, 0, socketHandle.ToInt32());
//write packet data to buffer. keep it in the try/catch because if
//processdata fails, this will fail because packet is null.
Marshal.Copy(packet.Data, 0, Buffer.buf, packet.Length);
} catch (Exception e)
{
Console.WriteLine("Serious error in Commands.cs: " + e + "\n");
#if DEBUG
Console.WriteLine("HOOK MAY BE DETACHED\n");
#endif
}
}
return(result);
}
