脚本

socket5.py

# -*- coding: utf-8 -*-
import asyncio
from struct import unpack, pack

"""
socket5协议学习
"""


async def handle_echo(reader, writer):
    data = await reader.read(1024 * 64)
    addr = writer.get_extra_info('peername')
    print(f"connect from {addr!r}")
    if len(data) < 3:
        print('too short...')
        writer.close()
        return
    result = unpack('!BBB', data[:3])
    writer.write(b'\x05\x00')
    await writer.drain()
    data = await reader.read(1024 * 64)
    result = unpack('!4B', data[:4])
    if result[0] == 5 and result[1] == 1 and result[3] == 3:
        host_len = unpack('!B', data[4:5])[0]
        host = data[5:host_len + 5].decode()
        port = unpack('!H', data[host_len + 5:])[0]
        print(f'len {host_len},host {host}，port {port}')
        try:
            reader_remote, writer_remote = await asyncio.open_connection(host, port)
            writer.write(pack('!5B', 5, 0, 0, 3, host_len) + host.encode() + pack('!H', port))
            await writer.drain()
            print(f'connect success！{host}')
        except (TimeoutError, ConnectionRefusedError) as _:
            print(f'connect failed！{host}')
            writer.write(pack('!5B', 5, 3, 0, 3, host_len) + host.encode() + pack('!H', port))
            await writer.drain()
            writer.close()
            return
        up_stream = _pipe(reader, writer_remote, host)
        down_stream = _pipe(reader_remote, writer, host)
        await asyncio.gather(up_stream, down_stream)
    if result[0] == 5 and result[1] == 1 and result[3] == 1:
        ip = '.'.join([str(a) for a in unpack('!BBBB', data[4:8])])
        port = unpack('H', data[8:10])[0]
        print(f'ip {ip}，port {port}')
        try:
            reader_remote, writer_remote = await asyncio.open_connection(ip, port)
            writer.write(pack('!8B', 5, 0, 0, 1, *unpack('!BBBB', data[4:8])) + pack('!H', port))
            await writer.drain()
            print(f'connect success！{ip}')
        except (TimeoutError, ConnectionRefusedError) as _:
            print(f'connect failed！{ip}，{repr(_)}')
            writer.write(pack('!8B', 5, 3, 0, 1, *unpack('!BBBB', data[4:8])) + pack('!H', port))
            await writer.drain()
            writer.close()
            return
        up_stream = _pipe(reader, writer_remote, ip)
        down_stream = _pipe(reader_remote, writer, ip)
        await asyncio.gather(up_stream, down_stream)


async def _pipe(reader, writer, host):
    while reader.at_eof:
        try:
            data = await reader.read(1024 * 64)
            if not data:
                writer.close()
                break
        except (ConnectionAbortedError, ConnectionResetError) as _:
            writer.close()
            print(f'{host} 异常退出 {repr(_)}')
            break
        try:
            writer.write(data)
            await writer.drain()
        except (ConnectionAbortedError, ConnectionResetError) as _:
            writer.close()
            print(f'{host} 异常退出 {repr(_)}')
            break
    print(f'{host} 退出')


async def main():
    server = await asyncio.start_server(
        handle_echo, '0.0.0.0', 3333)

    addr = server.sockets[0].getsockname()
    print(f'Serving on {addr}')

    async with server:
        await server.serve_forever()


loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.gather(main()))