1 # Copyright 2016, Tresys Technology, LLC 2 # 3 # This file is part of SETools. 4 # 5 # SETools is free software: you can redistribute it and/or modify 6 # it under the terms of the GNU Lesser General Public License as 7 # published by the Free Software Foundation, either version 2.1 of 8 # the License, or (at your option) any later version. 9 # 10 # SETools is distributed in the hope that it will be useful, 11 # but WITHOUT ANY WARRANTY; without even the implied warranty of 12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 # GNU Lesser General Public License for more details. 14 # 15 # You should have received a copy of the GNU Lesser General Public 16 # License along with SETools. If not, see 17 # <http://www.gnu.org/licenses/>. 18 # 19 from collections import namedtuple 20 21 from .context import ContextWrapper 22 from .descriptors import DiffResultDescriptor 23 from .difference import Difference, SymbolWrapper 24 25 26 modified_initsids_record = namedtuple("modified_initsid", ["added_context", "removed_context"]) 27 28 29 class InitialSIDsDifference(Difference): 30 31 """Determine the difference in initsids between two policies.""" 32 33 added_initialsids = DiffResultDescriptor("diff_initialsids") 34 removed_initialsids = DiffResultDescriptor("diff_initialsids") 35 modified_initialsids = DiffResultDescriptor("diff_initialsids") 36 37 def diff_initialsids(self): 38 """Generate the difference in initial SIDs between the policies.""" 39 40 self.log.info("Generating initial SID differences from {0.left_policy} to {0.right_policy}". 41 format(self)) 42 43 self.added_initialsids, self.removed_initialsids, matched_initialsids = self._set_diff( 44 (SymbolWrapper(i) for i in self.left_policy.initialsids()), 45 (SymbolWrapper(i) for i in self.right_policy.initialsids())) 46 47 self.modified_initialsids = dict() 48 49 for left_initialsid, right_initialsid in matched_initialsids: 50 # Criteria for modified initialsids 51 # 1. change to context 52 if ContextWrapper(left_initialsid.context) != ContextWrapper(right_initialsid.context): 53 self.modified_initialsids[left_initialsid] = modified_initsids_record( 54 right_initialsid.context, left_initialsid.context) 55 56 # 57 # Internal functions 58 # 59 def _reset_diff(self): 60 """Reset diff results on policy changes.""" 61 self.log.debug("Resetting initialsid differences") 62 self.added_initialsids = None 63 self.removed_initialsids = None 64 self.modified_initialsids = None 65
