Fix #120 - Limit hierarchical objects to 5 levels.

irrd/rpsl/fields.py

@@ -465,10 +465,15 @@ def parse_set_name(prefixes: List[str], value: str, messages: RPSLParserMessages
     output_components: List[str] = []
     prefix_display = '/'.join(prefixes)
 
+    if strict_validation and len(input_components) > 5:
+        messages.error(f'Set names can have a maximum of five components.')
+        return None
+
     if strict_validation and not any([c.upper().startswith(tuple(prefixes)) for c in input_components]):
         messages.error(f"Invalid set name {value}: at least one component must be "
                        f"an actual set name (i.e. start with {prefix_display})")
         return None
+
     for component in input_components:
         if strict_validation and component.upper() in reserved_words:
             messages.error(f"Invalid set name {value}: component {component} is a reserved word")

irrd/rpsl/tests/test_fields.py

@@ -249,14 +249,17 @@ def test_validate_set_name_field():
         "Set name AS01:AS-3 was reformatted as AS1:AS-3"
     ]
 
+    long_set = "AS1:AS-B:AS-C:AS-D:AS-E:AS-F"
     assert_validation_err("at least one component must be an actual set name", field.parse, "AS1",)
     assert_validation_err("at least one component must be an actual set name", field.parse, "AS1:AS3")
     assert_validation_err("not a valid AS number, nor does it start with AS-", field.parse, "AS1:AS-FOO:RS-FORBIDDEN")
     assert_validation_err("not a valid AS number nor a valid set name", field.parse, ":AS-FOO")
     assert_validation_err("not a valid AS number nor a valid set name", field.parse, "AS-FOO:")
+    assert_validation_err("can have a maximum of five components", field.parse, long_set)
     assert_validation_err("reserved word", field.parse, "AS1:AS-ANY")
 
     assert field.parse("AS-ANY", messages, strict_validation=False).value == "AS-ANY"
+    assert field.parse(long_set, messages, strict_validation=False).value == long_set
 
     field = RPSLSetNameField(prefix="RS")
     messages = RPSLParserMessages()