DNS.py 文件源码

def proxyrequest(self, request, host, port="53", protocol="udp"):
        clientip = {'clientip': self.client_address[0]}

        reply = None
        try:
            if DNSChef().ipv6:

                if protocol == "udp":
                    sock = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
                elif protocol == "tcp":
                    sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)

            else:
                if protocol == "udp":
                    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
                elif protocol == "tcp":
                    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

            sock.settimeout(3.0)

            # Send the proxy request to a randomly chosen DNS server

            if protocol == "udp":
                sock.sendto(request, (host, int(port)))
                reply = sock.recv(1024)
                sock.close()

            elif protocol == "tcp":
                sock.connect((host, int(port)))

                # Add length for the TCP request
                length = binascii.unhexlify("%04x" % len(request)) 
                sock.sendall(length+request)

                # Strip length from the response
                reply = sock.recv(1024)
                reply = reply[2:]

                sock.close()

        except Exception as e:
            log.warning("Could not proxy request: {}".format(e), extra=clientip)
            dnslog.info("Could not proxy request: {}".format(e), extra=clientip)
        else:
            return reply