How to pass real ip of connected client to python proxy?

Question

Python

Good day. I'm new to python, I recently got to sockets, it became necessary to write a proxy application that would proxy any traffic.
So, there is a proxy application that listens on a specific port, it must transmit information (traffic) to a given target, to its IP and port.

A small piece of server code:

HOST, PORT = "", 9091

server = ThreadedTCPServer((HOST, PORT), ThreadedTCPRequestHandler)
SocketServer.ThreadingTCPServer.allow_reuse_address = True
ip, port = server.server_address
server_thread = threading.Thread(target=server.serve_forever)
server_thread.daemon = True
server_thread.start()

Here comes the forwarding:

class Forwarder(threading.Thread):
def __init__(self, source):
threading.Thread.__init__(self)
self.source = source
self.dest = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.dest.connect (("target ip", 20000))

Everything works, but, of course, data containing the ip of the proxy application server, and not real clients, reaches the source.

The question is where to dig, what to use to transfer the IP of clients connected to the proxy.

Answer 1

Search for adding and processing x-forwarded-for header