Question

是否可以检测为什么在Python中关闭了套接字，即对方发送了FIN还是RST？

我知道检测另一端是否已发送FIN或RST的唯一方法是从套接字读取，并且如果获得空（字节）字符串，则我们已收到FIN或RST。但是如何知道哪一个呢？

import asyncio
import socket

async def async_main(loop):

    server_sock = socket.socket(family=socket.AF_INET, type=socket.SOCK_STREAM,
                                proto=socket.IPPROTO_TCP)
    server_sock.setblocking(False)
    server_sock.bind(('', 8080))
    server_sock.listen(socket.IPPROTO_TCP)

    loop = asyncio.get_event_loop()
    sock, adddress = await loop.sock_accept(server_sock)

    while True:
        data = await loop.sock_recv(sock, 1024)
        if data == b'':
            # Socket closed, but how?
            break
        print(data)

loop = asyncio.get_event_loop()
loop.run_until_complete(async_main(loop))

Answer 1

基于詹姆斯·K·波尔克（James K Polk）的comment（我认为是正确的），您可以通过捕获适当的异常来区分FIN与RST：

    while True:
        is_rst = False
        try:
            data = await loop.sock_recv(sock, 1024)
        except IOError as e:
            if e.errno == errno.ECONNRESET:
                data = b''
                is_rst = True
            else:
               raise
        if data == b'':
            # Connection closed - use is_rst to distinguish
            # between RST and FIN
            break
        print(data)

检测为什么关闭套接字：FIN vs RST

1 个答案: