901 - fixed how acls are added into list with new logic - agent cannot overwrite another acl in the list

src/primaite/acl/access_control_list.py

@@ -1,7 +1,7 @@
 # Crown Copyright (C) Dstl 2022. DEFCON 703. Shared in confidence.
 """A class that implements the access control list implementation for the network."""
 import logging
-from typing import Final, List
+from typing import Final, List, Union
 
 from primaite.acl.acl_rule import ACLRule
 from primaite.common.enums import RulePermissionType
@@ -22,7 +22,7 @@ class AccessControlList:
         # Maximum number of ACL Rules in ACL
         self.max_acl_rules: int = max_acl_rules
         # A list of ACL Rules
-        self._acl: List[ACLRule] = []
+        self._acl: List[Union[ACLRule, None]] = [None] * (self.max_acl_rules - 1)
         # Implicit rule
         self.acl_implicit_rule = None
         if self.apply_implicit_rule:
@@ -80,8 +80,11 @@ class AccessControlList:
              Indicates block if all conditions are satisfied.
         """
         for rule in self.acl:
+            print("loops through rule", rule, isinstance(rule, ACLRule))
             if isinstance(rule, ACLRule):
+                print("finds rule")
                 if self.check_address_match(rule, _source_ip_address, _dest_ip_address):
+                    print("source and dest ip match")
                     if (rule.get_protocol() == _protocol or rule.get_protocol() == "ANY") and (
                         str(rule.get_port()) == str(_port) or rule.get_port() == "ANY"
                     ):
@@ -94,7 +97,7 @@ class AccessControlList:
         # If there has been no rule to allow the IER through, it will return a blocked signal by default
         return True
 
-    def add_rule(self, _permission, _source_ip, _dest_ip, _protocol, _port, _position=None):
+    def add_rule(self, _permission, _source_ip, _dest_ip, _protocol, _port, _position):
         """
         Adds a new rule.
 
@@ -106,29 +109,26 @@ class AccessControlList:
             _port: the port
             _position: position to insert ACL rule into ACL list (starting from index 1 and NOT 0)
         """
-        position_index = int(_position)
+        try:
+            position_index = int(_position)
+        except TypeError:
+            _LOGGER.info(f"Position {_position} could not be converted to integer.")
+            return
+
         new_rule = ACLRule(_permission, _source_ip, _dest_ip, _protocol, str(_port))
-        if len(self._acl) + 1 < self.max_acl_rules:
-            if _position is not None:
-                if self.max_acl_rules - 1 > position_index > -1:
-                    try:
-                        # self._acl.insert(position_index, new_rule)
-                        if self._acl[position_index] is None:
-                            self.acl[position_index] = new_rule
-                    except Exception:
-                        _LOGGER.info(f"New Rule could NOT be added to list at position {position_index}.")
+        if self.max_acl_rules - 1 > position_index > -1:
+            try:
+                _LOGGER.info(f"Position {position_index} is valid.")
+                if self._acl[position_index] is None:
+                    _LOGGER.info(f"Inserting rule {new_rule} at position {position_index}")
+                    self._acl[position_index] = new_rule
                 else:
-                    _LOGGER.info(
-                        f"Position {position_index} is an invalid index for list/overwrites implicit firewall rule"
-                    )
-            else:
-                self.acl.append(new_rule)
+                    _LOGGER.info(f"Error: inserting rule at non-empty position {position_index}")
+                    return
+            except Exception:
+                _LOGGER.info(f"New Rule could NOT be added to list at position {position_index}.")
         else:
-            _LOGGER.info(
-                f"The ACL list is FULL."
-                f"The list of ACLs has length {len(self.acl)} and it has a max capacity of {self.max_acl_rules}."
-            )
-        # print("length of this list", len(self._acl))
+            _LOGGER.info(f"Position {position_index} is an invalid/overwrites implicit firewall rule")
 
     def remove_rule(self, _permission, _source_ip, _dest_ip, _protocol, _port):
         """

tests/test_acl.py

@@ -62,6 +62,7 @@ def test_check_acl_block_affirmative():
         acl_rule_port,
         acl_position_in_list,
     )
+    print(len(acl.acl), "len of acl list\n", acl.acl[0])
     assert acl.is_blocked("192.168.1.1", "192.168.1.2", "TCP", "80") == False