core/homeassistant/components/mqtt/util.py

93 lines
2.8 KiB
Python

"""Utility functions for the MQTT integration."""
from typing import Any
import voluptuous as vol
from homeassistant.const import CONF_PAYLOAD
from homeassistant.helpers import config_validation as cv, template
from .const import (
ATTR_PAYLOAD,
ATTR_QOS,
ATTR_RETAIN,
ATTR_TOPIC,
DEFAULT_QOS,
DEFAULT_RETAIN,
)
def valid_topic(value: Any) -> str:
"""Validate that this is a valid topic name/filter."""
value = cv.string(value)
try:
raw_value = value.encode("utf-8")
except UnicodeError as err:
raise vol.Invalid("MQTT topic name/filter must be valid UTF-8 string.") from err
if not raw_value:
raise vol.Invalid("MQTT topic name/filter must not be empty.")
if len(raw_value) > 65535:
raise vol.Invalid(
"MQTT topic name/filter must not be longer than 65535 encoded bytes."
)
if "\0" in value:
raise vol.Invalid("MQTT topic name/filter must not contain null character.")
return value
def valid_subscribe_topic(value: Any) -> str:
"""Validate that we can subscribe using this MQTT topic."""
value = valid_topic(value)
for i in (i for i, c in enumerate(value) if c == "+"):
if (i > 0 and value[i - 1] != "/") or (
i < len(value) - 1 and value[i + 1] != "/"
):
raise vol.Invalid(
"Single-level wildcard must occupy an entire level of the filter"
)
index = value.find("#")
if index != -1:
if index != len(value) - 1:
# If there are multiple wildcards, this will also trigger
raise vol.Invalid(
"Multi-level wildcard must be the last "
"character in the topic filter."
)
if len(value) > 1 and value[index - 1] != "/":
raise vol.Invalid(
"Multi-level wildcard must be after a topic level separator."
)
return value
def valid_subscribe_topic_template(value: Any) -> template.Template:
"""Validate either a jinja2 template or a valid MQTT subscription topic."""
tpl = template.Template(value)
if tpl.is_static:
valid_subscribe_topic(value)
return tpl
def valid_publish_topic(value: Any) -> str:
"""Validate that we can publish using this MQTT topic."""
value = valid_topic(value)
if "+" in value or "#" in value:
raise vol.Invalid("Wildcards can not be used in topic names")
return value
_VALID_QOS_SCHEMA = vol.All(vol.Coerce(int), vol.In([0, 1, 2]))
MQTT_WILL_BIRTH_SCHEMA = vol.Schema(
{
vol.Required(ATTR_TOPIC): valid_publish_topic,
vol.Required(ATTR_PAYLOAD, CONF_PAYLOAD): cv.string,
vol.Optional(ATTR_QOS, default=DEFAULT_QOS): _VALID_QOS_SCHEMA,
vol.Optional(ATTR_RETAIN, default=DEFAULT_RETAIN): cv.boolean,
},
required=True,
)