Make more max lengths constants and add additional MaxLengthExceeded checks (#50337)

* Add more MaxLengthExceeded checks

* remove some validations to reduce performance impact

* check length of generated entity ID

* dont check entity ID twice and use single context id length constant

* fix test

* add missing test

homeassistant/components/recorder/models.py

@@ -20,7 +20,14 @@ from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import relationship
 from sqlalchemy.orm.session import Session
 
-from homeassistant.const import MAX_LENGTH_EVENT_TYPE
+from homeassistant.const import (
+    MAX_LENGTH_EVENT_CONTEXT_ID,
+    MAX_LENGTH_EVENT_EVENT_TYPE,
+    MAX_LENGTH_EVENT_ORIGIN,
+    MAX_LENGTH_STATE_DOMAIN,
+    MAX_LENGTH_STATE_ENTITY_ID,
+    MAX_LENGTH_STATE_STATE,
+)
 from homeassistant.core import Context, Event, EventOrigin, State, split_entity_id
 from homeassistant.helpers.json import JSONEncoder
 import homeassistant.util.dt as dt_util
@@ -63,14 +70,14 @@ class Events(Base):  # type: ignore
     }
     __tablename__ = TABLE_EVENTS
     event_id = Column(Integer, Identity(), primary_key=True)
-    event_type = Column(String(MAX_LENGTH_EVENT_TYPE))
+    event_type = Column(String(MAX_LENGTH_EVENT_EVENT_TYPE))
     event_data = Column(Text().with_variant(mysql.LONGTEXT, "mysql"))
-    origin = Column(String(32))
+    origin = Column(String(MAX_LENGTH_EVENT_ORIGIN))
     time_fired = Column(DATETIME_TYPE, index=True)
     created = Column(DATETIME_TYPE, default=dt_util.utcnow)
-    context_id = Column(String(36), index=True)
+    context_id = Column(String(MAX_LENGTH_EVENT_CONTEXT_ID), index=True)
-    context_user_id = Column(String(36), index=True)
+    context_user_id = Column(String(MAX_LENGTH_EVENT_CONTEXT_ID), index=True)
-    context_parent_id = Column(String(36), index=True)
+    context_parent_id = Column(String(MAX_LENGTH_EVENT_CONTEXT_ID), index=True)
 
     __table_args__ = (
         # Used for fetching events at a specific time
@@ -130,9 +137,9 @@ class States(Base):  # type: ignore
     }
     __tablename__ = TABLE_STATES
     state_id = Column(Integer, Identity(), primary_key=True)
-    domain = Column(String(64))
+    domain = Column(String(MAX_LENGTH_STATE_DOMAIN))
-    entity_id = Column(String(255))
+    entity_id = Column(String(MAX_LENGTH_STATE_ENTITY_ID))
-    state = Column(String(255))
+    state = Column(String(MAX_LENGTH_STATE_STATE))
     attributes = Column(Text().with_variant(mysql.LONGTEXT, "mysql"))
     event_id = Column(
         Integer, ForeignKey("events.event_id", ondelete="CASCADE"), index=True

homeassistant/const.py

@@ -26,9 +26,14 @@ ENTITY_MATCH_ALL: Final = "all"
 # If no name is specified
 DEVICE_DEFAULT_NAME: Final = "Unnamed Device"
 
-# Max characters for an event_type (changing this requires a recorder
+# Max characters for data stored in the recorder (changes to these limits would require
-# database migration)
+# a database migration)
-MAX_LENGTH_EVENT_TYPE: Final = 64
+MAX_LENGTH_EVENT_EVENT_TYPE: Final = 64
+MAX_LENGTH_EVENT_ORIGIN: Final = 32
+MAX_LENGTH_EVENT_CONTEXT_ID: Final = 36
+MAX_LENGTH_STATE_DOMAIN: Final = 64
+MAX_LENGTH_STATE_ENTITY_ID: Final = 255
+MAX_LENGTH_STATE_STATE: Final = 255
 
 # Sun events
 SUN_EVENT_SUNSET: Final = "sunset"

homeassistant/core.py

@@ -47,7 +47,8 @@ from homeassistant.const import (
     EVENT_TIMER_OUT_OF_SYNC,
     LENGTH_METERS,
     MATCH_ALL,
-    MAX_LENGTH_EVENT_TYPE,
+    MAX_LENGTH_EVENT_EVENT_TYPE,
+    MAX_LENGTH_STATE_STATE,
     __version__,
 )
 from homeassistant.exceptions import (
@@ -130,7 +131,7 @@ def valid_entity_id(entity_id: str) -> bool:
 
 def valid_state(state: str) -> bool:
     """Test if a state is valid."""
-    return len(state) < 256
+    return len(state) <= MAX_LENGTH_STATE_STATE
 
 
 def callback(func: CALLABLE_T) -> CALLABLE_T:
@@ -700,8 +701,10 @@ class EventBus:
 
         This method must be run in the event loop.
         """
-        if len(event_type) > MAX_LENGTH_EVENT_TYPE:
+        if len(event_type) > MAX_LENGTH_EVENT_EVENT_TYPE:
-            raise MaxLengthExceeded(event_type, "event_type", MAX_LENGTH_EVENT_TYPE)
+            raise MaxLengthExceeded(
+                event_type, "event_type", MAX_LENGTH_EVENT_EVENT_TYPE
+            )
 
         listeners = self._listeners.get(event_type, [])
 

homeassistant/helpers/entity_registry.py

@@ -24,6 +24,8 @@ from homeassistant.const import (
     ATTR_SUPPORTED_FEATURES,
     ATTR_UNIT_OF_MEASUREMENT,
     EVENT_HOMEASSISTANT_START,
+    MAX_LENGTH_STATE_DOMAIN,
+    MAX_LENGTH_STATE_ENTITY_ID,
     STATE_UNAVAILABLE,
 )
 from homeassistant.core import (
@@ -33,6 +35,7 @@ from homeassistant.core import (
     split_entity_id,
     valid_entity_id,
 )
+from homeassistant.exceptions import MaxLengthExceeded
 from homeassistant.helpers import device_registry as dr
 from homeassistant.helpers.device_registry import EVENT_DEVICE_REGISTRY_UPDATED
 from homeassistant.loader import bind_hass
@@ -201,6 +204,10 @@ class EntityRegistry:
         Conflicts checked against registered and currently existing entities.
         """
         preferred_string = f"{domain}.{slugify(suggested_object_id)}"
+
+        if len(domain) > MAX_LENGTH_STATE_DOMAIN:
+            raise MaxLengthExceeded(domain, "domain", MAX_LENGTH_STATE_DOMAIN)
+
         test_string = preferred_string
         if not known_object_ids:
             known_object_ids = {}
@@ -214,6 +221,11 @@ class EntityRegistry:
             tries += 1
             test_string = f"{preferred_string}_{tries}"
 
+        if len(test_string) > MAX_LENGTH_STATE_ENTITY_ID:
+            raise MaxLengthExceeded(
+                test_string, "generated_entity_id", MAX_LENGTH_STATE_ENTITY_ID
+            )
+
         return test_string
 
     @callback

tests/helpers/test_entity_registry.py

@@ -6,6 +6,7 @@ import pytest
 from homeassistant import config_entries
 from homeassistant.const import EVENT_HOMEASSISTANT_START, STATE_UNAVAILABLE
 from homeassistant.core import CoreState, callback, valid_entity_id
+from homeassistant.exceptions import MaxLengthExceeded
 from homeassistant.helpers import device_registry as dr, entity_registry as er
 
 from tests.common import (
@@ -904,3 +905,47 @@ async def test_disabled_entities_excluded_from_entity_list(hass, registry):
         registry, device_entry.id, include_disabled_entities=True
     )
     assert entries == [entry1, entry2]
+
+
+async def test_entity_max_length_exceeded(hass, registry):
+    """Test that an exception is raised when the max character length is exceeded."""
+
+    long_entity_id_name = (
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+    )
+
+    with pytest.raises(MaxLengthExceeded) as exc_info:
+        registry.async_generate_entity_id("sensor", long_entity_id_name)
+
+    assert exc_info.value.property_name == "generated_entity_id"
+    assert exc_info.value.max_length == 255
+    assert exc_info.value.value == f"sensor.{long_entity_id_name}"
+
+    # Try again but against the domain
+    long_domain_name = long_entity_id_name
+    with pytest.raises(MaxLengthExceeded) as exc_info:
+        registry.async_generate_entity_id(long_domain_name, "sensor")
+
+    assert exc_info.value.property_name == "domain"
+    assert exc_info.value.max_length == 64
+    assert exc_info.value.value == long_domain_name
+
+    # Try again but force a number to get added to the entity ID
+    long_entity_id_name = (
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+        "1234567890123456789012345678901234567890123456789012345678901234567890"
+        "1234567890123456789012345678901234567"
+    )
+
+    with pytest.raises(MaxLengthExceeded) as exc_info:
+        registry.async_generate_entity_id(
+            "sensor", long_entity_id_name, [f"sensor.{long_entity_id_name}"]
+        )
+
+    assert exc_info.value.property_name == "generated_entity_id"
+    assert exc_info.value.max_length == 255
+    assert exc_info.value.value == f"sensor.{long_entity_id_name}_2"