Fix creating policy rules from subattributes.

In case of policy rule checks for rules like e.g.
"create_port:fixed_ips:subnet" couldn't be created to be
passed to policy enforcer because policy module could only
create rule checks for subattributes which are dict types.

With this patch checks for such rules can be created also for
attributes which are list of dicts, like e.g. fixed_ips in port
resource.

Change-Id: I02fffe77f57a513d2362df78885d327042bb8095
Closes-Bug: #1822105
(cherry picked from commit 9318fb8bb9)

neutron/conf/policies/port.py

@@ -68,7 +68,8 @@ rules = [
     policy.DocumentedRuleDefault(
         'create_port:fixed_ips',
         base.policy_or(base.RULE_ADVSVC,
-                       base.RULE_ADMIN_OR_NET_OWNER),
+                       base.RULE_ADMIN_OR_NET_OWNER,
+                       'rule:shared'),
         'Specify ``fixed_ips`` information when creating a port',
         ACTION_POST
     ),
@@ -118,6 +119,20 @@ rules = [
         'Specify ``allowed_address_pairs`` attribute when creating a port',
         ACTION_POST
     ),
+    policy.DocumentedRuleDefault(
+        'create_port:allowed_address_pairs:mac_address',
+        base.RULE_ADMIN_OR_NET_OWNER,
+        ('Specify ``mac_address` of `allowed_address_pairs`` '
+         'attribute when creating a port'),
+        ACTION_POST
+    ),
+    policy.DocumentedRuleDefault(
+        'create_port:allowed_address_pairs:ip_address',
+        base.RULE_ADMIN_OR_NET_OWNER,
+        ('Specify ``ip_address`` of ``allowed_address_pairs`` '
+         'attribute when creating a port'),
+        ACTION_POST
+    ),
 
     policy.DocumentedRuleDefault(
         'get_port',
@@ -235,6 +250,20 @@ rules = [
         'Update ``allowed_address_pairs`` attribute of a port',
         ACTION_PUT
     ),
+    policy.DocumentedRuleDefault(
+        'update_port:allowed_address_pairs:mac_address',
+        base.RULE_ADMIN_OR_NET_OWNER,
+        ('Update ``mac_address`` of ``allowed_address_pairs`` '
+         'attribute of a port'),
+        ACTION_PUT
+    ),
+    policy.DocumentedRuleDefault(
+        'update_port:allowed_address_pairs:ip_address',
+        base.RULE_ADMIN_OR_NET_OWNER,
+        ('Update ``ip_address`` of ``allowed_address_pairs`` '
+         'attribute of a port'),
+        ACTION_PUT
+    ),
     policy.DocumentedRuleDefault(
         'update_port:data_plane_status',
         'rule:admin_or_data_plane_int',

neutron/policy.py

@@ -153,6 +153,17 @@ def _build_subattr_match_rule(attr_name, attr, action, target):
     return policy.AndCheck(sub_attr_rules)
 
 
+def _build_list_of_subattrs_rule(attr_name, attribute_value, action):
+    rules = []
+    for sub_attr in attribute_value:
+        if isinstance(sub_attr, dict):
+            for k in sub_attr:
+                rules.append(policy.RuleCheck(
+                    'rule', '%s:%s:%s' % (action, attr_name, k)))
+    if rules:
+        return policy.AndCheck(rules)
+
+
 def _process_rules_list(rules, match_rule):
     """Recursively walk a policy rule to extract a list of match entries."""
     if isinstance(match_rule, policy.RuleCheck):
@@ -188,8 +199,8 @@ def _build_match_rule(action, target, pluralized):
                                                 target, action):
                     attribute = res_map[resource][attribute_name]
                     if 'enforce_policy' in attribute:
-                        attr_rule = policy.RuleCheck('rule', '%s:%s' %
-                                                     (action, attribute_name))
+                        attr_rule = policy.RuleCheck(
+                            'rule', '%s:%s' % (action, attribute_name))
                         # Build match entries for sub-attributes
                         if _should_validate_sub_attributes(
                                 attribute, target[attribute_name]):
@@ -197,6 +208,15 @@ def _build_match_rule(action, target, pluralized):
                                 [attr_rule, _build_subattr_match_rule(
                                     attribute_name, attribute,
                                     action, target)])
+
+                        attribute_value = target[attribute_name]
+                        if isinstance(attribute_value, list):
+                            subattr_rule = _build_list_of_subattrs_rule(
+                                attribute_name, attribute_value, action)
+                            if subattr_rule:
+                                attr_rule = policy.AndCheck(
+                                    [attr_rule, subattr_rule])
+
                         match_rule = policy.AndCheck([match_rule, attr_rule])
     return match_rule
 

neutron/tests/unit/test_policy.py

@@ -184,7 +184,13 @@ FAKE_RESOURCES = {"%ss" % FAKE_RESOURCE_NAME:
                             'validate': {'type:dict':
                                          {'sub_attr_1': {'type:string': None},
                                           'sub_attr_2': {'type:string': None}}}
-                            }},
+                            },
+                   'list_attr': {'allow_post': True,
+                                 'allow_put': True,
+                                 'is_visible': True,
+                                 'default': None,
+                                 'enforce_policy': True
+                                 }},
                   # special plural name
                   "%s" % FAKE_SPECIAL_RESOURCE_NAME.replace('y', 'ies'):
                   {'attr': {'allow_post': True,
@@ -253,6 +259,10 @@ class NeutronPolicyTestCase(base.BaseTestCase):
             "create_fake_resource:attr": "rule:admin_or_owner",
             "create_fake_resource:attr:sub_attr_1": "rule:admin_or_owner",
             "create_fake_resource:attr:sub_attr_2": "rule:admin_only",
+            "create_fake_resource:list_attr": "rule:admin_only_or_owner",
+            "create_fake_resource:list_attr:admin_element": "rule:admin_only",
+            "create_fake_resource:list_attr:user_element": (
+                "rule:admin_or_owner"),
 
             "create_fake_policy:": "rule:admin_or_owner",
         }
@@ -471,6 +481,23 @@ class NeutronPolicyTestCase(base.BaseTestCase):
                               action,
                               target)
 
+    def test_enforce_subattribute_as_list(self):
+        action = "create_" + FAKE_RESOURCE_NAME
+        target = {
+            'tenant_id': 'fake',
+            'list_attr': [{'user_element': 'x'}]}
+        result = policy.enforce(self.context,
+                                action, target, None)
+        self.assertTrue(result)
+
+    def test_enforce_subattribute_as_list_forbiden(self):
+        action = "create_" + FAKE_RESOURCE_NAME
+        target = {
+            'tenant_id': 'fake',
+            'list_attr': [{'admin_element': 'x'}]}
+        self.assertRaises(oslo_policy.PolicyNotAuthorized, policy.enforce,
+                          self.context, action, target, None)
+
     def test_retryrequest_on_notfound(self):
         failure = exceptions.NetworkNotFound(net_id='whatever')
         action = "create_port:mac"