| # Copyright 2016, Tresys Technology, LLC |
| # |
| # 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 namedtuple |
| |
| from .descriptors import DiffResultDescriptor |
| from .difference import Difference, SymbolWrapper |
| |
| |
| modified_typeattr_record = namedtuple("modified_typeattr", ["added_types", |
| "removed_types", |
| "matched_types"]) |
| |
| |
| class TypeAttributesDifference(Difference): |
| |
| """Determine the difference in type attributes between two policies.""" |
| |
| added_type_attributes = DiffResultDescriptor("diff_type_attributes") |
| removed_type_attributes = DiffResultDescriptor("diff_type_attributes") |
| modified_type_attributes = DiffResultDescriptor("diff_type_attributes") |
| |
| def diff_type_attributes(self): |
| """Generate the difference in type attributes between the policies.""" |
| |
| self.log.info( |
| "Generating type attribute differences from {0.left_policy} to {0.right_policy}". |
| format(self)) |
| |
| self.added_type_attributes, self.removed_type_attributes, matched_attributes = \ |
| self._set_diff( |
| (SymbolWrapper(r) for r in self.left_policy.typeattributes()), |
| (SymbolWrapper(r) for r in self.right_policy.typeattributes())) |
| |
| self.modified_type_attributes = dict() |
| |
| for left_attribute, right_attribute in matched_attributes: |
| # Criteria for modified attributes |
| # 1. change to type set |
| added_types, removed_types, matched_types = self._set_diff( |
| (SymbolWrapper(t) for t in left_attribute.expand()), |
| (SymbolWrapper(t) for t in right_attribute.expand())) |
| |
| if added_types or removed_types: |
| self.modified_type_attributes[left_attribute] = modified_typeattr_record( |
| added_types, removed_types, matched_types) |
| |
| # |
| # Internal functions |
| # |
| def _reset_diff(self): |
| """Reset diff results on policy changes.""" |
| self.log.debug("Resetting type attribute differences") |
| self.added_type_attributes = None |
| self.removed_type_attributes = None |
| self.modified_type_attributes = None |
