def fetch_content(request: werkzeug.Request,
                  response: werkzeug.Response) -> None:
    url = request.args["url"]
    proxy_query_header = make_request_headers(request.headers)

    try:
        proxy_response = requests.get(url,
                                      headers=proxy_query_header,
                                      timeout=TIMEOUT)
    except requests.exceptions.SSLError:
        # Invalid SSL Certificate
        response.status = 526
    except requests.exceptions.ConnectionError:
        response.status = 523
    except requests.exceptions.Timeout:
        response.status = 524
    except requests.exceptions.TooManyRedirects:
        response.status = 520
    else:
        response.body = proxy_response.content
        if proxy_response.status_code == 500:
            response.status = 520
        else:
            copy_proxy_headers(proxy_response, response)

    response.headers["Access-Control-Allow-Origin"] = get_access_url(
        request.headers)
    def _application(self, environ, start_response):
        request = Request(environ)
        self.logger.info(request.full_path)

        status_code = 200
        headers = {'Content-Type': 'application/json'}
        content = ''

        if request.path == '/':  # 接管主页,因为所有请求需要token,主页转发不能正常工作
            headers = {'Content-Type': 'text/html'}
            content = '<h1><a href="https://github.com/xiyaoWong/iotbot-http-transfer">iotbot http tranfer</a><h1>'
        elif request.path.strip('/') == 'favicon.ico':
            status_code = 301
            del headers['Content-Type']
            headers['location'] = 'https://cdn.jsdelivr.net/gh/xiyaowong/FileHost/transfer.png'
        elif request.path.strip('/') == 'genToken':  # 处理token生成请求
            key = request.args.get('key')
            if key == self.key:
                token = self._genarate_token('ok, it\' funny.')
                content = json.dumps({'token': token})
            else:
                content = '{"Ret":1111, "Msg":"key错误"}'
        else:  # 处理其他请求
            # 鉴权
            token = request.args.get('token') or request.headers.get('Authorization')
            if not self._check_token(token):  # 大胆,狗贼
                content = '{"Ret":2222, "Msg":"无效的token"}'
            else:
                try:
                    resp = requests.request(
                        request.method,
                        '{}{}?{}'.format(
                            'http://{}:{}'.format(self.iotbot_host, self.iotbot_port),
                            request.path,
                            request.query_string.decode()),
                        headers=request.headers,
                        data=request.data,
                        timeout=self.timeout
                    )
                except requests.Timeout as e:
                    self.logger.warning(e)
                    content = '{"Ret":3333, "Msg":"请求响应超时"}'
                except requests.ConnectionError as e:
                    self.logger.exception(e)
                    content = '{"Ret":4444, "Msg":"连接错误"}'
                except Exception as e:
                    self.logger.exception(e)
                    content = '{"Ret":5555, "Msg":"请求响应失败"}'
                else:
                    content = resp.content
                    status_code = resp.status_code
                    headers = resp.headers

        response = Response(content)
        response.status = HTTP_STATUS_CODES[status_code]
        response.status_code = status_code
        for header_name, header_value in headers.items():
            response.headers[header_name] = header_value
        return response(environ, start_response)