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, Wrapper 24 25 26 modified_portcon_record = namedtuple("modified_portcon", ["rule", 27 "added_context", 28 "removed_context"]) 29 30 31 class PortconsDifference(Difference): 32 33 """Determine the difference in portcons between two policies.""" 34 35 added_portcons = DiffResultDescriptor("diff_portcons") 36 removed_portcons = DiffResultDescriptor("diff_portcons") 37 modified_portcons = DiffResultDescriptor("diff_portcons") 38 39 def diff_portcons(self): 40 """Generate the difference in portcons between the policies.""" 41 42 self.log.info("Generating portcon differences from {0.left_policy} to {0.right_policy}". 43 format(self)) 44 45 self.added_portcons, self.removed_portcons, matched_portcons = self._set_diff( 46 (PortconWrapper(n) for n in self.left_policy.portcons()), 47 (PortconWrapper(n) for n in self.right_policy.portcons())) 48 49 self.modified_portcons = [] 50 51 for left_portcon, right_portcon in matched_portcons: 52 # Criteria for modified portcons 53 # 1. change to context 54 if ContextWrapper(left_portcon.context) != ContextWrapper(right_portcon.context): 55 self.modified_portcons.append(modified_portcon_record(left_portcon, 56 right_portcon.context, 57 left_portcon.context)) 58 59 # 60 # Internal functions 61 # 62 def _reset_diff(self): 63 """Reset diff results on policy changes.""" 64 self.log.debug("Resetting portcon differences") 65 self.added_portcons = None 66 self.removed_portcons = None 67 self.modified_portcons = None 68 69 70 class PortconWrapper(Wrapper): 71 72 """Wrap portcon statements for diff purposes.""" 73 74 def __init__(self, ocon): 75 self.origin = ocon 76 self.protocol = ocon.protocol 77 self.low, self.high = ocon.ports 78 self.key = hash(ocon) 79 80 def __hash__(self): 81 return self.key 82 83 def __lt__(self, other): 84 return self.origin < other.origin 85 86 def __eq__(self, other): 87 return self.protocol == other.protocol and \ 88 self.low == other.low and \ 89 self.high == other.high 90
