# Copyright 2016, Tresys Technology, LLC # # SPDX-License-Identifier: LGPL-2.1-only # from typing import NamedTuple from ..policyrep import Context, FSUse from .context import ContextWrapper from .descriptors import DiffResultDescriptor from .difference import Difference, Wrapper class ModifiedFSUse(NamedTuple): """Difference details for a modified fs_use_*.""" rule: FSUse added_context: Context removed_context: Context class FSUsesDifference(Difference): """Determine the difference in fs_use_* rules between two policies.""" added_fs_uses = DiffResultDescriptor("diff_fs_uses") removed_fs_uses = DiffResultDescriptor("diff_fs_uses") modified_fs_uses = DiffResultDescriptor("diff_fs_uses") def diff_fs_uses(self) -> None: """Generate the difference in fs_use rules between the policies.""" self.log.info( "Generating fs_use_* differences from {0.left_policy} to {0.right_policy}". format(self)) self.added_fs_uses, self.removed_fs_uses, matched = self._set_diff( (FSUseWrapper(fs) for fs in self.left_policy.fs_uses()), (FSUseWrapper(fs) for fs in self.right_policy.fs_uses())) self.modified_fs_uses = [] for left_rule, right_rule in matched: # Criteria for modified rules # 1. change to context if ContextWrapper(left_rule.context) != ContextWrapper(right_rule.context): self.modified_fs_uses.append(ModifiedFSUse(left_rule, right_rule.context, left_rule.context)) # # Internal functions # def _reset_diff(self) -> None: """Reset diff results on policy changes.""" self.log.debug("Resetting fs_use_* rule differences") self.added_fs_uses = None self.removed_fs_uses = None self.modified_fs_uses = None class FSUseWrapper(Wrapper[FSUse]): """Wrap fs_use_* rules to allow set operations.""" __slots__ = ("ruletype", "fs", "context") def __init__(self, rule: FSUse) -> None: self.origin = rule self.ruletype = rule.ruletype self.fs = rule.fs self.context = ContextWrapper(rule.context) 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.fs == other.fs