TCP Rerouting using Pythons socket module

python-tcp-reroute.py

import multiprocessing
import time
import socket


def process_1():
    # this demonstrates a third party lib
    print("Process 1 is running")
    while True:
        time.sleep(10)
        host = "localhost"
        port = 5555

        client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        client.connect((host,port))
        client.send(b"9")

        response = client.recv(4096)
        print("Client", response)
        client.close()

def process_2():
    # this demonstrates the functionality of the internal port forwarder
    print("Process 2 is running")

    # Define the local and remote addresses
    LOCAL_HOST = 'localhost'
    LOCAL_PORT = 5555
    REMOTE_HOST = 'localhost'
    REMOTE_PORT = 4444

    # Create a socket object
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    # Bind the socket to a local address
    server_socket.bind((LOCAL_HOST, LOCAL_PORT))

    # Listen for incoming connections
    server_socket.listen(1)

    print('Server listening on {}:{}'.format(LOCAL_HOST, LOCAL_PORT))

    # Accept incoming connections and forward traffic to the remote host
    while True:
        client_socket, client_address = server_socket.accept()
        print('Accepted connection from {}:{}'.format(client_address[0], client_address[1]))
        
        # Connect to the remote host
        remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        remote_socket.connect((REMOTE_HOST, REMOTE_PORT))
        
        # Forward incoming data to the remote host
        data = client_socket.recv(1024)
        print("client sent", data)
        if not data:
            break
        remote_socket.sendall(data)
        
        # Forward outgoing data from the remote host back to the client
        data = remote_socket.recv(1024)
        print("remote sent", data)
        if not data:
            break
        client_socket.sendall(data)

        # Close the sockets
        client_socket.close()
        remote_socket.close()

if __name__ == '__main__':
    p1 = multiprocessing.Process(target=process_1)
    p2 = multiprocessing.Process(target=process_2)
    
    p1.start()
    p2.start()

    p1.join()
    p2.join()