Python代理-> dansguardian：如何发送原始源ip？

Question

我有一个DNS的python代理。 当我收到DNS请求时，我需要代表原始源将http请求传递给dansguardian，让它决定对请求的处理方式，获取结果，并根据dansguardian的响应将客户端重定向到其他地方。

网络骨架是这样的：

Client -> DNS Proxy -> DG -> Privoxy -> Web.

客户端请求A ，DNS代理拦截，代表客户端询问DG，得到答案：1.如果DG对其进行了过滤，则代理发送本地IP地址而不是A问题的实际IP。 2.如果DG没有过滤，DNS代理服务器将使客户端的网络自然流动。

这是我尝试过的示例python代码：

        data,addr = sock.recvfrom(1024)
        OriginalDNSPacket = data
        # I get OriginalDNSPacket from a socket
        # to which iptables redirected all port 53 packets
        UDPanswer = sendQues(OriginalDNSPacket, '8.8.8.8') 
        proxies = {'http': 'http://127.0.0.1:8080'} # DG Port
        s = requests.Session()

        d = DNSRecord.parse(UDPanswer)
        print d
        ques_domain = str(d.questions[0].get_qname())[:-1]
        ques_tld = tldextract.extract(ques_domain)
        ques_tld = "{}.{}".format(ques_tld.domain, ques_tld.suffix)
        print ques_tld
        for rr in d.rr:
            try:
                s.mount("http://"+ques_tld, SourceAddressAdapter(addr[0])) # This was a silly try, I know.
                s.proxies.update(proxies)
                response = s.get("http://"+ques_tld)
                print dir(response.content)
                print response.content
                if "Access Denied" in response.content:
                    d.rr = []
                    d.add_answer(*RR.fromZone(ques_domain + " A " + SERVER_IP))
                    d.add_answer(*RR.fromZone(ques_domain + " AAAA  fe80::a00:27ff:fe4a:c8ec"))
                    print d
                    socket.sendto(d.pack(), addr)
                    return
                else:
                    socket.sendto(UDPanswer, addr)
                    return
            except Exception, e:
                print e
                pass

问题是如何将请求发送给DG，并欺骗请求（例如，请求来自客户端）？

Answer 1

在dansguardian.conf中，需要启用usexforwardedfor 。

因此，conf现在看起来像这样：

...
# if on it adds an X-Forwarded-For: <clientip> to the HTTP request
# header.  This may help solve some problem sites that need to know the
# source ip. on | off
forwardedfor = on


# if on it uses the X-Forwarded-For: <clientip> to determine the client
# IP. This is for when you have squid between the clients and DansGuardian.
# Warning - headers are easily spoofed. on | off
usexforwardedfor = on
...

在代理服务器上，我只需要添加以下内容（我之前曾尝试过），但是由于DG conf的原因，它不起作用：

response = s.get("http://"+ques_tld, headers={'X-Forwarded-For': addr[0]})

它像魅力一样运作。

谢谢@boardrider。