import socket
+import sys
+from abc import abstractmethod, ABCMeta
+from cStringIO import StringIO
+
+
+def ppp(headline, packet):
+ """ Return string containing the output of scapy packet.show() call. """
+ o = StringIO()
+ old_stdout = sys.stdout
+ sys.stdout = o
+ print(headline)
+ packet.show()
+ sys.stdout = old_stdout
+ return o.getvalue()
+
+
+class NumericConstant(object):
+ __metaclass__ = ABCMeta
+
+ desc_dict = {}
+
+ @abstractmethod
+ def __init__(self, value):
+ self._value = value
+
+ def __int__(self):
+ return self._value
+
+ def __long__(self):
+ return self._value
+
+ def __str__(self):
+ if self._value in self.desc_dict:
+ return self.desc_dict[self._value]
+ return ""
+
class Host(object):
""" Generic test host "connected" to VPPs interface. """