NetUtils.py

class NetUtils:

    @classmethod
    def CheckInterfaceConnected(cls, inDev):

        dev_path = "/sys/class/net/%s" % inDev

        carrier_path = dev_path + "/carrier"
        opersate_path = dev_path + "/operstate"

        retry = 3
        carrier = 0
        while retry > 0:
            try:
                fd = open(carrier_path, 'rb')
                carrier = fd.read()
                break
            except IOError as e:
                code, msg = e.args
                if code == 22: # Invalid argument
                    ShellPipe('ip', 'link', 'set', 'dev', inDev, 'up').Call()
                    retry = retry-1
                    continue
                elif code == 2: # No such file or directory
                    fd = None
                    raise Exception('NIC interface %s Not Found', inDev)
                else:
                    raise
            finally:
                if fd:
                    fd.close()

        if int(carrier) == 1:
            return True

        return False
        
    @classmethod
    def GetInterfaceIP(cls, inDev):
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        return socket.inet_ntoa(fcntl.ioctl(
                s.fileno(),
                0x8915,  # SIOCGIFADDR
                struct.pack('256s', ifname[:15])
            )[20:24])