[fix] Fixed subnet division rule validation on empty subnet #866

openwisp_controller/subnet_division/base/models.py

@@ -71,6 +71,7 @@ def rule_class(self):
     def clean(self):
         super().clean()
         self._validate_label()
+        self._validate_master_subnet_validity()
         self._validate_master_subnet_consistency()
         self._validate_ip_address_consistency()
         if not self._state.adding:
@@ -86,6 +87,10 @@ def _validate_label(self):
                 }
             )
 
+    def _validate_master_subnet_validity(self):
+        if not self.master_subnet.subnet:
+            raise ValidationError({'master_subnet': _('Invalid master subnet.')})
+
     def _validate_existing_fields(self):
         db_instance = self._meta.model.objects.get(id=self.id)
         # The size field should not be changed
@@ -104,10 +109,10 @@ def _validate_existing_fields(self):
 
     def _validate_master_subnet_consistency(self):
         master_subnet = self.master_subnet.subnet
-        # Ensure that the size of the generated subnet
-        # is not greater than size of master subnet
+        # Try to generate subnets and validate size
         try:
             next(master_subnet.subnets(new_prefix=self.size))
+        # if size is not consistent, raise error
         except ValueError:
             raise ValidationError(
                 {
@@ -118,7 +123,6 @@ def _validate_master_subnet_consistency(self):
                     )
                 }
             )
-
         # Ensure that master subnet can accommodate
         # the required number of generated subnets
         available = 2 ** (self.size - master_subnet.prefixlen)
@@ -135,7 +139,6 @@ def _validate_master_subnet_consistency(self):
                     )
                 }
             )
-
         # Validate organization of master subnet
         if (
             self.master_subnet.organization is not None

openwisp_controller/subnet_division/tests/test_models.py

@@ -956,6 +956,27 @@ def test_single_subnet_vpn_device_rule(self):
             device_rule.number_of_subnets,
         )
 
+    def test_invalid_master_subnet(self):
+        # Instantiate a subnet without setting its 'subnet' attribute
+        invalid_subnet = Subnet(name='Invalid Subnet')
+        rule = SubnetDivisionRule(
+            type='openwisp_controller.subnet_division.rule_types.vpn.'
+            'VpnSubnetDivisionRuleType',
+            label='TEST',
+            size=28,
+            number_of_subnets=2,
+            number_of_ips=2,
+            organization=self.org,
+            master_subnet=invalid_subnet,  # Invalid master_subnet
+        )
+        with self.assertRaises(ValidationError) as cm:
+            rule.full_clean()
+        e = cm.exception
+        self.assertIn(
+            'Invalid master subnet.',
+            e.message_dict.get('master_subnet', []),
+        )
+
 
 class TestOpenVPNSubnetDivisionRule(
     SubnetDivisionTestMixin,