# Copyright 2016, Tresys Technology, LLC # # SPDX-License-Identifier: LGPL-2.1-only # from typing import NamedTuple, Optional from ..policyrep import Context, Netifcon from .context import ContextWrapper from .descriptors import DiffResultDescriptor from .difference import Difference, Wrapper class ModifiedNetifcon(NamedTuple): """Difference details for a modified netifcon.""" rule: Netifcon added_context: Optional[Context] removed_context: Optional[Context] added_packet: Optional[Context] removed_packet: Optional[Context] class NetifconsDifference(Difference): """Determine the difference in netifcons between two policies.""" added_netifcons = DiffResultDescriptor("diff_netifcons") removed_netifcons = DiffResultDescriptor("diff_netifcons") modified_netifcons = DiffResultDescriptor("diff_netifcons") def diff_netifcons(self) -> None: """Generate the difference in netifcons between the policies.""" self.log.info("Generating netifcon differences from {0.left_policy} to {0.right_policy}". format(self)) self.added_netifcons, self.removed_netifcons, matched_netifcons = self._set_diff( (NetifconWrapper(n) for n in self.left_policy.netifcons()), (NetifconWrapper(n) for n in self.right_policy.netifcons())) self.modified_netifcons = [] for left_netifcon, right_netifcon in matched_netifcons: # Criteria for modified netifcons # 1. change to context # 2. change to packet context if ContextWrapper(left_netifcon.context) != ContextWrapper(right_netifcon.context): removed_context = left_netifcon.context added_context = right_netifcon.context else: removed_context = None added_context = None if ContextWrapper(left_netifcon.packet) != ContextWrapper(right_netifcon.packet): removed_packet = left_netifcon.packet added_packet = right_netifcon.packet else: removed_packet = None added_packet = None if removed_context or removed_packet: self.modified_netifcons.append(ModifiedNetifcon( left_netifcon, added_context, removed_context, added_packet, removed_packet)) # # Internal functions # def _reset_diff(self) -> None: """Reset diff results on policy changes.""" self.log.debug("Resetting netifcon differences") self.added_netifcons = None self.removed_netifcons = None self.modified_netifcons = None class NetifconWrapper(Wrapper[Netifcon]): """Wrap netifcon statements for diff purposes.""" __slots__ = ("netif") def __init__(self, ocon: Netifcon) -> None: self.origin = ocon self.netif = ocon.netif self.key = hash(ocon) def __hash__(self): return self.key def __lt__(self, other): return self.netif < other.netif def __eq__(self, other): return self.netif == other.netif