# Copyright 2016, Tresys Technology, LLC # Copyright 2018, Chris PeBenito <pebenito@ieee.org> # # SPDX-License-Identifier: LGPL-2.1-only # from typing import cast, List, NamedTuple, Optional from ..policyrep import Bounds, BoundsRuletype, Type from .descriptors import DiffResultDescriptor from .difference import Difference, Wrapper from .types import type_wrapper_factory class ModifiedBounds(NamedTuple): """Difference details for a modified bounds rule.""" rule: Bounds added_bound: Type removed_bound: Type class BoundsDifference(Difference): """Determine the difference in *bounds between two policies.""" added_typebounds = DiffResultDescriptor("diff_typebounds") removed_typebounds = DiffResultDescriptor("diff_typebounds") modified_typebounds = DiffResultDescriptor("diff_typebounds") # Lists of rules for each policy _left_typebounds: Optional[List[Bounds]] = None _right_typebounds: Optional[List[Bounds]] = None def diff_typebounds(self) -> None: """Generate the difference in typebound rules between the policies.""" self.log.info("Generating typebounds differences from {0.left_policy} to {0.right_policy}". format(self)) if self._left_typebounds is None or self._right_typebounds is None: self._create_typebound_lists() self.added_typebounds, self.removed_typebounds, matched_typebounds = self._set_diff( (BoundsWrapper(c) for c in cast(List[Bounds], self._left_typebounds)), (BoundsWrapper(c) for c in cast(List[Bounds], self._right_typebounds)), key=lambda b: str(b.child)) self.modified_typebounds = [] for left_bound, right_bound in matched_typebounds: if type_wrapper_factory(left_bound.parent) != type_wrapper_factory(right_bound.parent): self.modified_typebounds.append(ModifiedBounds( left_bound, right_bound.parent, left_bound.parent)) # # Internal functions # def _create_typebound_lists(self) -> None: """Create rule lists for both policies.""" self._left_typebounds = [] for rule in self.left_policy.bounds(): if rule.ruletype == BoundsRuletype.typebounds: self._left_typebounds.append(rule) else: self.log.error("Unknown rule type: {0} (This is an SETools bug)". format(rule.ruletype)) self._right_typebounds = [] for rule in self.right_policy.bounds(): if rule.ruletype == BoundsRuletype.typebounds: self._right_typebounds.append(rule) else: self.log.error("Unknown rule type: {0} (This is an SETools bug)". format(rule.ruletype)) def _reset_diff(self) -> None: """Reset diff results on policy changes.""" self.log.debug("Resetting all *bounds differences") self.added_typebounds = None self.removed_typebounds = None # Sets of rules for each policy self._left_typebounds = None self._right_typebounds = None class BoundsWrapper(Wrapper[Bounds]): """Wrap *bounds for diff purposes.""" __slots__ = ("ruletype", "parent", "child") def __init__(self, rule: Bounds) -> None: self.origin = rule self.ruletype = rule.ruletype self.parent = type_wrapper_factory(rule.parent) self.child = type_wrapper_factory(rule.child) self.key = hash(rule) def __hash__(self): return self.key def __lt__(self, other): return self.key < other.key def __eq__(self, other): return self.ruletype == other.ruletype and \ self.child == other.child