#
# Copyright (c) 2011, EPFL (Ecole Politechnique Federale de Lausanne)
# All rights reserved.
#
# Created by Marco Canini, Daniele Venzano, Dejan Kostic, Jennifer Rexford
# Contributed to this file: Peter Peresini
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#   -  Redistributions of source code must retain the above copyright notice,
#      this list of conditions and the following disclaimer.
#   -  Redistributions in binary form must reproduce the above copyright notice,
#      this list of conditions and the following disclaimer in the documentation
#      and/or other materials provided with the distribution.
#   -  Neither the names of the contributors, nor their associated universities or
#      organizations may be used to endorse or promote products derived from this
#      software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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from invariant import Invariant
from violation import Violation

from lib.of_modify_state_message import ModifyStateMessage
from lib.of_packet_out_message import PacketOutMessage

class NoTruncate(Invariant):
	def __init__(self):
		Invariant.__init__(self, "NoTruncate")

	def path_start_cb(self, model):
		self.bufid = None
		self.packetname = None

	def before_cnt_packet_in_cb(self, buffer_id, packet, inport, reason):
		self.bufid = buffer_id
		self.packetname = packet.name

	def after_cnt_packet_in_cb(self, controller, packet, return_value):
		self.bufid = None

	def switch_enqueue_command_cb(self, switch, command):
		if isinstance(command, ModifyStateMessage) or isinstance(command, PacketOutMessage):
			if command.packet is not None and \
					self.packetname == command.packet.name and \
					command.buffer_id != self.bufid:
				v = Violation(self, "Truncated packet " + str(command.packet))
				self.reportViolation(v)

	def __getstate__(self):
		return {}
