A async python transparent proxy server (based on iptables TPROXY, asyncio, aiosock)

tproxy.py

import asyncio
from asyncio.streams import start_server
import socket
import aiosocks
import logging

logging.basicConfig(level = logging.WARNING)

log = logging.getLogger(__name__)

async def forward(reader, writer):
    while True:
        d = await reader.read(1024)
        if len(d) == 0:
            break
        writer.write(d)
    writer.close()
    await writer.wait_closed()

async def main():
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_TRANSPARENT, 1)
    sock.bind(('127.0.0.1', 10080))

    async def worker(reader, writer):
        sockname = writer.get_extra_info('sockname') # original destination
        log.warning('got connection, intended for %s', sockname)

        socks5_addr = aiosocks.Socks5Addr('127.0.0.1', 1337)
        preader,pwriter = await aiosocks.open_connection(proxy=socks5_addr, proxy_auth=None, dst=sockname)

        asyncio.create_task(forward(reader, pwriter))
        asyncio.create_task(forward(preader, writer))

    server = await asyncio.start_server(worker, sock = sock)
    await server.serve_forever()

if __name__ == '__main__':
    asyncio.run(main())