Thanks J :) Absolutely! I did try various flags to optimise performance. For CreateFile (which in .NET is wrapped by the FileStream class) I tried FILE_WRITE_THROUGH (which is FileOptions.WriteThrough in .NET), and found it impacted performance quite a lot.

The key to high performance as you rightly pointed out was preventing flushing. In the end, what worked best was reducing the number of writes to disk (which is the bottleneck). I did that by buffering 10-50 ms worth of TCP data, coupled with only flushing explicitly (using a large buffer so that neither BinaryWriter or FileStream flush automatically).

I think you can use named pipes if you are using SMB. Here is a example code in python (not tested).

import socket import win32pipe import win32file import sys

BUFFER_SIZE = 4096

def create_pipe(pipe_name): return win32pipe.CreateNamedPipe(pipe_name, win32pipe.PIPE_ACCESS_DUPLEX, win32pipe.PIPE_TYPE_BYTE | win32pipe.PIPE_READMODE_BYTE | win32pipe.PIPE_WAIT, 1, BUFFER_SIZE, BUFFER_SIZE, 0, None)

def open_pipe(pipe_name): return win32file.CreateFile(pipe_name, win32file.GENERIC_READ | win32file.GENERIC_WRITE, 0, None, win32file.OPEN_EXISTING, 0, None)

def proxy_server(machine_name): server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server_socket.bind(('0.0.0.0', 8080)) server_socket.listen(1)

    pipe_name_1 = r'\\' + machine_name + r'\pipe\proxy_pipe_1'
    pipe_name_2 = r'\\' + machine_name + r'\pipe\proxy_pipe_2'

    while True:
        client_socket, _ = server_socket.accept()
        pipe_1, pipe_2 = create_pipe(pipe_name_1), create_pipe(pipe_name_2)
        win32pipe.ConnectNamedPipe(pipe_1, None)
        win32pipe.ConnectNamedPipe(pipe_2, None)

        while True:
            data = client_socket.recv(BUFFER_SIZE)
            if not data:
                break
            win32file.WriteFile(pipe_1, data)
            response = win32file.ReadFile(pipe_2, BUFFER_SIZE)[1]
            client_socket.send(response)

        client_socket.close()
        win32file.CloseHandle(pipe_1)
        win32file.CloseHandle(pipe_2)

def proxy_client(server_name, machine_name): target_host, target_port = 'cnn.com', 80

    pipe_name_1 = r'\\' + server_name + r'\pipe\proxy_pipe_1_' + machine_name
    pipe_name_2 = r'\\' + server_name + r'\pipe\proxy_pipe_2_' + machine_name

    pipe_1, pipe_2 = open_pipe(pipe_name_1), open_pipe(pipe_name_2)
    target_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    target_socket.connect((target_host, target_port))

    while True:
        data = win32file.ReadFile(pipe_1, BUFFER_SIZE)[1]
        if not data:
            break
        target_socket.send(data)
        response = target_socket.recv(BUFFER_SIZE)
        win32file.WriteFile(pipe_2, response)

    target_socket.close()
    win32file.CloseHandle(pipe_1)
    win32file.CloseHandle(pipe_2)

if __name__ == '__main__': if len(sys.argv) < 3: print("Usage: python script.py [server|client] [machine_name] [server_name (for client only)]") sys.exit(1)

    mode, machine_name = sys.argv[1], sys.argv[2]

    if mode == 'server':
        proxy_server(machine_name)
    elif mode == 'client':
        if len(sys.argv) < 4:
            print("Please provide the server name or IP address for the client mode.")
            sys.exit(1)
        server_name = sys.argv[3]
        proxy_client(server_name, machine_name)
    else:
        print("Invalid mode. Please use 'server' or 'client'.")
        sys.exit(1)

You wrote all that without testing anything? Oh you used ChatGPT probably

That's awesome!