有没有办法限制到 Twisted 协议服务器中特定端口的连接数？

Question

我有一个 python Twisted 服务器应用程序与旧客户端应用程序接口，并且每个客户端都被分配了一个特定的端口来连接到服务器。所以我已经在服务器上的所有这些端口上设置了监听器，它工作得很好，但是我需要建立一些保护措施来禁止多个客户端连接到同一个服务器端口上。当另一个客户端连接到同一个端口时，客户端应用程序上有太多东西会中断，我现在无法更新该应用程序。我必须忍受它的运作方式。 我知道我可以在 connectionMade() 函数中构建一些逻辑，以查看该端口上是否已经存在某人，如果存在，则关闭这个新连接。但我宁愿有一种方法来拒绝它，所以甚至不允许客户端连接。然后客户端会知道他们犯了一个错误，他们可以改变他们尝试连接的端口。

如果有帮助，这里是我的服务器代码的精简版。

from twisted.internet.protocol import Factory
from twisted.internet.protocol import Protocol
from twisted.internet import reactor
from twisted.internet import task
import time

class MyServerTasks():
    def someFunction(msg):
        #Do stuff

    def someOtherFunction(msg):
        #Do other stuff

class MyServer(Protocol):

    def __init__(self, users):
        self.users = users
        self.name = None

    def connectionMade(self):
        #Depending on which port is connected, go do stuff

    def connectionLost(self, reason):
        #Update dictionaries and other global info

    def dataReceived(self, line):
        t = time.strftime('%Y-%m-%d %H:%M:%S')
        d = self.transport.getHost()
        print("{} Received message from {}:{}...{}".format(t, d.host, d.port, line))  #debug
        self.handle_GOTDATA(line)

    def handle_GOTDATA(self, msg):
        #Parse the received data string and do stuff based on the message.
        #For example:
        if "99" in msg:
            MyServerTasks.someFunction(msg)

class MyServerFactory(Factory):

    def __init__(self):
        self.users = {} # maps user names to Chat instances

    def buildProtocol(self, *args, **kwargs):
        protocol = MyServer(self.users)
        protocol.factory = self
        protocol.factory.clients = []
        return protocol

reactor.listenTCP(50010, MyServerFactory())
reactor.listenTCP(50011, MyServerFactory())
reactor.listenTCP(50012, MyServerFactory())
reactor.listenTCP(50013, MyServerFactory())

reactor.run()

Answer 1

当客户端连接到服务器时，twisted使用factory创建 一个protocol（通过调用它的buildProtocol方法）实例来处理客户端请求。

因此，您可以在MyServerFactory 中维护已连接客户端的计数器， 如果计数器已达到最大允许连接的客户端，您可以返回 None 而不是为该客户端创建新协议。 如果工厂没有返回协议，Twisted 将关闭客户端连接 它的buildProtocol 方法。

you can see here

class MyServer(Protocol):

def __init__(self, users):
    self.users = users
    self.name = None

def connectionMade(self):
    #Depending on which port is connected, go do stuff

def connectionLost(self, reason):
    #Update dictionaries and other global info
    self.factory.counter -= 1

def dataReceived(self, line):
    t = time.strftime('%Y-%m-%d %H:%M:%S')
    d = self.transport.getHost()
    print("{} Received message from {}:{}...{}".format(t, d.host, d.port, line))  #debug
    self.handle_GOTDATA(line)

def handle_GOTDATA(self, msg):
    #Parse the received data string and do stuff based on the message.
    #For example:
    if "99" in msg:
        MyServerTasks.someFunction(msg)



 class MyServerFactory(Factory):
   MAX_CLIENT = 2

 def __init__(self):
    self.users = {} # maps user names to Chat instances
    self.counter = 0

 def buildProtocol(self, *args, **kwargs):
    if self.counter == self.MAX_CLIENT:
        return None
    self.counter += 1
    protocol = MyServer(self.users)
    protocol.factory = self
    protocol.factory.clients = []
    return protocol