python - UDP 打洞不起作用

Question

我正在尝试创建一个聊天程序，该程序通过 UDP 打洞并直接连接到代理提供的节点。

我现在的脚本在本地运行得很好。当我尝试使用外部地址进行连接时，问题就出现了。我自己无法解决这个问题，所以我希望有人可以帮助我!

import socket
import json
import landerdb
import threading

class PeerChat:

    address = None

    def __init__(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.db = landerdb.Connect("nodes")
        self.brok_ip = ""
        self.brok_port = 5000
        self.nick = "Test"
        self.friends = []

    def listen(self):
        self.command = {

            "HERE":self.here,
            "MSG":self.msg,
            } 

        global address
        self.sock.bind(address)
        while True:
            msg, addr = self.sock.recvfrom(1024)
            try:
                data = json.loads(msg)
            except:
                continue
            if data[u'cmd'] in self.command:
                threading.Thread(target=self.command[data[u'cmd']], args=(addr, data)).start()

    def main(self):
        while True:
            msg = raw_input("> ")
            msg = msg.split()
            try:
                msg = json.dumps({"cmd":msg[0], "data":' '.join(msg[2:]), "nick":self.nick, "to":msg[1]})
            except:
                continue
            for x in self.db.find("nodes", "all"):
                self.sock.sendto(msg, tuple(x['addr']))

    def here(self, addr, data):
        if not self.db.find("nodes", {"addr":addr}):
            self.db.insert("nodes", {"addr":addr})
        if data['nick'] in self.friends:
            print data['nick'] + " has come online."
    def msg(self, addr, data):
        if data['to'] == self.nick:
            print data['nick']+": "+data['data']

    def GetNodes(self):
        self.sock.sendto("", (self.brok_ip, self.brok_port))
        with open("nodes", 'wb') as file:
            while True:
                msg, addr = self.sock.recvfrom(1024)
                if msg == "\n":
                    break
                file.write(msg)
        msg, addr = self.sock.recvfrom(1024)
        global address 
        address = ("0.0.0.0", int(msg))   
        for x in self.db.find("nodes", "all"):
            addr = tuple(x['addr'])
            self.sock.sendto(json.dumps({"cmd":"HERE", "nick":self.nick}),addr)

if __name__ == "__main__":
    PeerChat().GetNodes()
    threading.Thread(target=PeerChat().listen).start()
    PeerChat().main()

Answer 1

我还没有在外部测试过这段代码，因为我在大学，但我使用稍微不同的线路来设置 UDP 连接。

他们可能会给你一些想法......

#!/usr/bin/python
import socket
import struct

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('239.255.60.60', 4876)) 
mreq = struct.pack("=4sl", socket.inet_aton("239.255.60.60"), socket.INADDR_ANY)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
packet_number = 0

while True:

    packet_number += 1
    print packet_number
    raw_data = sock.recv(1024)
    print raw_data
    print

我并不完全理解这一切，但它对我有用。改编自here 。您应该阅读整个页面几次以了解他们在说什么。搜索“IP_MULTICAST_TTL”页面，我发现您需要在 sock.setsockopt 中设置 socket.IP_MULTICAST_TTL, 33，其中数字是大于 32 的任何数字。请记住，我几乎同样不确定正如您现阶段...