ipdiscover.py 文件源码

def get_local_ip():
    """
    Returns a deferred which will be called with a
    2-uple (lan_flag, ip_address) :
        - lan_flag:
            - True if it's a local network (RFC1918)
            - False if it's a WAN address

        - ip_address is the actual ip address

    @return: A deferred called with the above defined tuple
    @rtype: L{twisted.internet.defer.Deferred}
    """
    # first we try a connected udp socket, then via multicast
    logging.debug("Resolving dns to get udp ip")
    try:
        ipaddr = yield reactor.resolve('A.ROOT-SERVERS.NET')
    except:
        pass
    else:
        udpprot = DatagramProtocol()
        port = reactor.listenUDP(0, udpprot)
        udpprot.transport.connect(ipaddr, 7)
        localip = udpprot.transport.getHost().host
        port.stopListening()

        if is_bogus_ip(localip):
            raise RuntimeError, "Invalid IP address returned"
        else:
            defer.returnValue((is_rfc1918_ip(localip), localip))

    logging.debug("Multicast ping to retrieve local IP")
    ipaddr = yield _discover_multicast()
    defer.returnValue((is_rfc1918_ip(ipaddr), ipaddr))