需要帮助在两个套接字之间创建TCP中继

Question

我遇到了以下情况：

SomeServer(S) <-> (C)MyApp(S) <-> (C)User

(S) represents a server socket
(C) represents a client socket

基本上，MyApp 和 SomeServer 之间开始进行通信（SomeServer(S) <-> (C)MyApp），一旦一些身份验证程序成功，MyApp(S) 就开始等待 (C)User 连接。一旦 User 连接上，MyApp 就会把 SomeServer 的数据转发给 User。这个过程是双向的。

我已经成功实现了 SomeServer(S) <-> (C)MyApp 的部分，但我无法让 MyApp(S) <-> (C)User 正常工作。我能做到的是 User 成功连接到 MyApp(S)，但无法转发数据！

好的，希望这能让你明白 ;) 现在让我展示一下我的 MyApp 的代码。顺便说一下，SomeServer 和 User 的实现对解决我的问题并不重要，因为这两个部分都无法修改。

我在代码中添加了注释，指出了我遇到问题的地方。哦，我还应该提到，如果有必要，我可以完全放弃“服务器部分”的代码，换成其他代码。这只是一个概念验证（POC），所以我主要关注的是功能的实现，而不是编写高效的代码。感谢你的时间。

''' MyApp.py module '''

import asyncore, socket
import SSL

# Client Section
# Connects to SomeServer

class MyAppClient(asyncore.dispatcher):

    def __init__(self, host, port):
        asyncore.dispatcher.__init__(self)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.connect((host, port))

    connectionPhase = 1
    def handle_read(self):
        print "connectionPhase =", self.connectionPhase

    # The following IF statements may not make sense
    # as I have removed code irrelevant to this question

    if self.connectionPhase < 3: # authentication phase
            data = self.recv(1024)
            print 'Received:', data

            # Client/Server authentication is handled here
            # Everything from this point on happens over
            # an encrypted socket using SSL

            # Start the RelayServer listening on localhost 8080
            # self.socket is encrypted and is the socket communicating
            # with SomeServer

            rs = RelayServer(('localhost', 8080), self.socket)
            print 'RelayServer started'

        # connectionPhase = 3 when this IF loop is done

        elif self.connectionPhase == 3: # receiving data for User
            data = self.recv(1024)

            print 'Received data - forward to User:', data

            # Forward this data to User
            # Don't understand why data is being read here
            # when the RelayServer was instantiated above

# Server Section
# Connects to User

class RelayConnection(asyncore.dispatcher):
    def __init__(self, client, sock):
        asyncore.dispatcher.__init__(self)
        self.client = client
        print "connecting to %s..." % str(sock)

    def handle_connect(self):
        print "connected."
        # Allow reading once the connection
        # on the other side is open.
        self.client.is_readable = True


    # For some reason this never runs, i.e. data from SomeServer
    # isn't read here, but instead in MyAppClient.handle_read()
    # don't know how to make it arrive here instead as it should
    # be relayed to User

    def handle_read(self):
        self.client.send(self.recv(1024))

class RelayClient(asyncore.dispatcher):
    def __init__(self, server, client, sock):
        asyncore.dispatcher.__init__(self, client)
        self.is_readable = False
        self.server = server
        self.relay = RelayConnection(self, sock)

    def handle_read(self):
        self.relay.send(self.recv(1024))

    def handle_close(self):
        print "Closing relay..."
        # If the client disconnects, close the
        # relay connection as well.
        self.relay.close()
        self.close()

    def readable(self):
        return self.is_readable

class RelayServer(asyncore.dispatcher):
    def __init__(self, bind_address, MyAppClient_sock):
        asyncore.dispatcher.__init__(self)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.bind(bind_address)
        self.MyAppClient_sock = MyAppClient_sock
        print self.MyAppClient_sock
        self.listen(1)

    def handle_accept(self):
        conn, addr = self.accept()
        RelayClient(self, conn, self.MyAppClient_sock)

if __name__ == "__main__":
    # Connect to host
    # First connection stage
    connectionPhase = 1
    c = MyAppClient('host', port) # SomeServer's host and port

    asyncore.loop()

编辑：

@samplebias 我用你的代码（未显示）替换了我的整个模块，并重新添加了我需要的所有身份验证等部分。

此时，我得到的结果和我之前的代码是一样的。我的意思是，MyApp（或你代码中的服务器）已经连接到 SomeServer，并且数据可以双向传输。到目前为止一切正常。当 User（或客户端应用程序）连接到 localhost 8080 时，这段代码会被执行：

if not self.listener:
    self.listener = Listener(self.listener_addr, self)

但是，这段代码没有被执行

  # if user is attached, send data
    elif self.user:
        print 'self.user'
        self.user.send(data)

所以，服务器没有把数据转发给用户。我在用户类中添加了打印语句，以查看哪些代码被执行，只有 init 被执行，而 handle_read() 从未运行。

这是为什么呢？

事件处理身份验证套接字编程客户端-服务器模型概念验证双向通信 tcp中继数据转发

需要帮助在两个套接字之间创建TCP中继

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