| # 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, Wrapper |
| |
| |
| modified_bounds_record = namedtuple("modified_bound", ["rule", "added_bound", "removed_bound"]) |
| |
| |
| 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 = None |
| _right_typebounds = None |
| |
| def diff_typebounds(self): |
| """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 self._left_typebounds), |
| (BoundsWrapper(c) for c in self._right_typebounds), |
| key=lambda b: str(b.child)) |
| |
| self.modified_typebounds = [] |
| |
| for left_bound, right_bound in matched_typebounds: |
| if SymbolWrapper(left_bound.parent) != SymbolWrapper(right_bound.parent): |
| self.modified_typebounds.append(modified_bounds_record( |
| left_bound, right_bound.parent, left_bound.parent)) |
| |
| # |
| # Internal functions |
| # |
| def _create_typebound_lists(self): |
| """Create rule lists for both policies.""" |
| self._left_typebounds = [] |
| for rule in self.left_policy.bounds(): |
| if rule.ruletype == "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 == "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): |
| """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): |
| |
| """Wrap *bounds for diff purposes.""" |
| |
| def __init__(self, rule): |
| self.origin = rule |
| self.ruletype = rule.ruletype |
| self.parent = SymbolWrapper(rule.parent) |
| self.child = SymbolWrapper(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 |
