# Copyright 2016, Tresys Technology, LLC
# Copyright 2017, Chris PeBenito <pebenito@ieee.org>
#
# SPDX-License-Identifier: LGPL-2.1-only
#
from typing import NamedTuple
from ..policyrep import Context, Nodecon
from .context import ContextWrapper
from .descriptors import DiffResultDescriptor
from .difference import Difference, Wrapper
class ModifiedNodecon(NamedTuple):
"""Difference details for a modified netifcon."""
rule: Nodecon
added_context: Context
removed_context: Context
class NodeconsDifference(Difference):
"""Determine the difference in nodecons between two policies."""
added_nodecons = DiffResultDescriptor("diff_nodecons")
removed_nodecons = DiffResultDescriptor("diff_nodecons")
modified_nodecons = DiffResultDescriptor("diff_nodecons")
def diff_nodecons(self) -> None:
"""Generate the difference in nodecons between the policies."""
self.log.info("Generating nodecon differences from {0.left_policy} to {0.right_policy}".
format(self))
self.added_nodecons, self.removed_nodecons, matched_nodecons = self._set_diff(
(NodeconWrapper(n) for n in self.left_policy.nodecons()),
(NodeconWrapper(n) for n in self.right_policy.nodecons()))
self.modified_nodecons = []
for left_nodecon, right_nodecon in matched_nodecons:
# Criteria for modified nodecons
# 1. change to context
if ContextWrapper(left_nodecon.context) != ContextWrapper(right_nodecon.context):
self.modified_nodecons.append(ModifiedNodecon(left_nodecon,
right_nodecon.context,
left_nodecon.context))
#
# Internal functions
#
def _reset_diff(self) -> None:
"""Reset diff results on policy changes."""
self.log.debug("Resetting nodecon differences")
self.added_nodecons = None
self.removed_nodecons = None
self.modified_nodecons = None
class NodeconWrapper(Wrapper[Nodecon]):
"""Wrap nodecon statements for diff purposes."""
__slots__ = ("ip_version", "network")
def __init__(self, ocon: Nodecon) -> None:
self.origin = ocon
self.ip_version = ocon.ip_version
self.network = ocon.network
self.key = hash(ocon)
def __hash__(self):
return self.key
def __lt__(self, other):
return self.origin < other.origin
def __eq__(self, other):
return self.ip_version == other.ip_version and \
self.network == other.network
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