URLFetcher/traffic-forwarder.py

import socket
import sys
import threading
import time

def server(local_port, remote_cid, remote_port):
    try:
        dock_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        dock_socket.bind(('', local_port))
        dock_socket.listen(5)

        while True:
            client_socket = dock_socket.accept()[0]

            server_socket = socket.socket(socket.AF_VSOCK, socket.SOCK_STREAM)
            server_socket.connect((remote_cid, remote_port))

            outgoing_thread = threading.Thread(target = forward, args = (client_socket, server_socket))
            incoming_thread = threading.Thread(target = forward, args = (server_socket, client_socket))

            outgoing_thread.start()
            incoming_thread.start()
    finally:
        new_thread = threading.Thread(target = server, args = (local_port, remote_cid, remote_port))
        new_thread.start()
    
    return

def forward(source, destination):
    string = ' '
    while string:
        string = source.recv(1024)
        if string:
            destination.sendall(string)
        else:
            source.shutdown(socket.SHUT_RD)
            destination.shutdown(socket.SHUT_WR)

def main(args):
    local_port = int(args[0])
    remote_cid = int(args[1])
    remote_port = int(args[2])

    thread = threading.Thread(target = server, args = (local_port, remote_cid, remote_port))
    thread.start()

    while True:
       time.sleep(60)

if __name__ == '__main__':
    main(sys.argv[1:])