| # 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 .context import ContextWrapper |
| from .descriptors import DiffResultDescriptor |
| from .difference import Difference, Wrapper |
| |
| |
| modified_fsuse_record = namedtuple("modified_fsuse", ["rule", |
| "added_context", |
| "removed_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): |
| """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(modified_fsuse_record(left_rule, |
| right_rule.context, |
| left_rule.context)) |
| |
| # |
| # Internal functions |
| # |
| def _reset_diff(self): |
| """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): |
| |
| """Wrap fs_use_* rules to allow set operations.""" |
| |
| def __init__(self, rule): |
| 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 |