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Current Path : /lib64/python3.6/site-packages/setools/diff/ |
Current File : //lib64/python3.6/site-packages/setools/diff/mlsrules.py |
# Copyright 2016, Tresys Technology, LLC # Copyright 2018, Chris PeBenito <pebenito@ieee.org> # # This file is part of SETools. # # SETools is free software: you can redistribute it and/or modify # it under the terms of the GNU Lesser General Public License as # published by the Free Software Foundation, either version 2.1 of # the License, or (at your option) any later version. # # SETools is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with SETools. If not, see # <http://www.gnu.org/licenses/>. # from collections import defaultdict, namedtuple from .. import MLSRuletype from .descriptors import DiffResultDescriptor from .difference import Difference, Wrapper from .mls import RangeWrapper from .objclass import class_wrapper_factory from .types import type_or_attr_wrapper_factory modified_mlsrule_record = namedtuple("modified_mlsrule", ["rule", "added_default", "removed_default"]) class MLSRulesDifference(Difference): """Determine the difference in MLS rules between two policies.""" added_range_transitions = DiffResultDescriptor("diff_range_transitions") removed_range_transitions = DiffResultDescriptor("diff_range_transitions") modified_range_transitions = DiffResultDescriptor("diff_range_transitions") # Lists of rules for each policy _left_mls_rules = defaultdict(list) _right_mls_rules = defaultdict(list) def diff_range_transitions(self): """Generate the difference in range_transition rules between the policies.""" self.log.info( "Generating range_transition differences from {0.left_policy} to {0.right_policy}". format(self)) if not self._left_mls_rules or not self._right_mls_rules: self._create_mls_rule_lists() added, removed, matched = self._set_diff( self._expand_generator(self._left_mls_rules[MLSRuletype.range_transition], MLSRuleWrapper), self._expand_generator(self._right_mls_rules[MLSRuletype.range_transition], MLSRuleWrapper)) modified = [] for left_rule, right_rule in matched: # Criteria for modified rules # 1. change to default range if RangeWrapper(left_rule.default) != RangeWrapper(right_rule.default): modified.append(modified_mlsrule_record(left_rule, right_rule.default, left_rule.default)) self.added_range_transitions = added self.removed_range_transitions = removed self.modified_range_transitions = modified # # Internal functions # def _create_mls_rule_lists(self): """Create rule lists for both policies.""" # do not expand yet, to keep memory # use down as long as possible self.log.debug("Building MLS rule lists from {0.left_policy}".format(self)) for rule in self.left_policy.mlsrules(): self._left_mls_rules[rule.ruletype].append(rule) self.log.debug("Building MLS rule lists from {0.right_policy}".format(self)) for rule in self.right_policy.mlsrules(): self._right_mls_rules[rule.ruletype].append(rule) self.log.debug("Completed building MLS rule lists.") def _reset_diff(self): """Reset diff results on policy changes.""" self.log.debug("Resetting MLS rule differences") self.added_range_transitions = None self.removed_range_transitions = None self.modified_range_transitions = None # Sets of rules for each policy self._left_mls_rules.clear() self._right_mls_rules.clear() class MLSRuleWrapper(Wrapper): """Wrap MLS rules to allow set operations.""" __slots__ = ("ruletype", "source", "target", "tclass") def __init__(self, rule): self.origin = rule self.source = type_or_attr_wrapper_factory(rule.source) self.target = type_or_attr_wrapper_factory(rule.target) self.tclass = class_wrapper_factory(rule.tclass) self.key = hash(rule) def __hash__(self): return self.key def __lt__(self, other): return self.key < other.key def __eq__(self, other): # because MLSRuleDifference groups rules by ruletype, # the ruletype always matches. return self.source == other.source and \ self.target == other.target and \ self.tclass == other.tclass