python - 如何在 python + twisted 中检测 HTTP 请求？

Question

我正在使用 python 中的 twisted 10 学习网络编程。在下面的代码中，有什么方法可以在收到数据时检测 HTTP 请求？还从中检索域名、子域、端口值？如果不是 http 数据就丢弃它？

from twisted.internet import stdio, reactor, protocol

from twisted.protocols import basic

import re



class DataForwardingProtocol(protocol.Protocol):

    def _ _init_ _(self):

        self.output = None

        self.normalizeNewlines = False



    def dataReceived(self, data):

        if self.normalizeNewlines:

            data = re.sub(r"(\r\n|\n)", "\r\n", data)

        if self.output:

            self.output.write(data)



class StdioProxyProtocol(DataForwardingProtocol):

    def connectionMade(self):

        inputForwarder = DataForwardingProtocol( )

        inputForwarder.output = self.transport

        inputForwarder.normalizeNewlines = True

        stdioWrapper = stdio.StandardIO(inputForwarder)

        self.output = stdioWrapper

        print "Connected to server.  Press ctrl-C to close connection."



class StdioProxyFactory(protocol.ClientFactory):

    protocol = StdioProxyProtocol



    def clientConnectionLost(self, transport, reason):

        reactor.stop( )



    def clientConnectionFailed(self, transport, reason):

        print reason.getErrorMessage( )

        reactor.stop( )



if __name__ == '_ _main_ _':

    import sys

    if not len(sys.argv) == 3:

        print "Usage: %s host port" % _ _file_ _

        sys.exit(1)



    reactor.connectTCP(sys.argv[1], int(sys.argv[2]), StdioProxyFactory( ))

    reactor.run( )

Answer 1

protocol.dataReceived ，你要覆盖的，级别太低，无法在没有你没有做的智能缓冲的情况下达到目的——根据我刚刚引用的文档，

Called whenever data is received.

Use this method to translate to a higher-level message. Usually, some callback will be made upon the receipt of each complete protocol message.

Parameters

data

a string of indeterminate length. Please keep in mind that you will probably need to buffer some data, as partial (or multiple) protocol messages may be received! I recommend that unit tests for protocols call through to this method with differing chunk sizes, down to one byte at a time.

您似乎完全忽略了文档的这一关键部分。

您可以改为使用 LineReceiver.lineReceived (当然，继承自 protocols.basic.LineReceiver)以利用 HTTP 请求以“行”形式出现的事实——您仍然需要连接作为多个发送的 header 行，因为 this tutorial说:

Header lines beginning with space or tab are actually part of the previous header line, folded into multiple lines for easy reading.

一旦您有了格式良好/经过解析的响应(考虑研究 twisted.web's sources 以便找到一种可以完成的方法)，

retrieve Domain name, Sub Domain, Port values from this?

现在 Host header (参见 the RFC 第 14.23 节)包含此信息。