core/homeassistant/components/snmp/sensor.py

285 lines
9.0 KiB
Python

"""Support for displaying collected data over SNMP."""
from __future__ import annotations
from datetime import timedelta
import logging
from struct import unpack
from pyasn1.codec.ber import decoder
from pysnmp.error import PySnmpError
import pysnmp.hlapi.asyncio as hlapi
from pysnmp.hlapi.asyncio import (
CommunityData,
Udp6TransportTarget,
UdpTransportTarget,
UsmUserData,
getCmd,
)
from pysnmp.proto.rfc1902 import Opaque
from pysnmp.proto.rfc1905 import NoSuchObject
import voluptuous as vol
from homeassistant.components.sensor import (
CONF_STATE_CLASS,
PLATFORM_SCHEMA as SENSOR_PLATFORM_SCHEMA,
)
from homeassistant.const import (
CONF_DEVICE_CLASS,
CONF_HOST,
CONF_ICON,
CONF_NAME,
CONF_PORT,
CONF_UNIQUE_ID,
CONF_UNIT_OF_MEASUREMENT,
CONF_USERNAME,
CONF_VALUE_TEMPLATE,
STATE_UNKNOWN,
)
from homeassistant.core import HomeAssistant
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.helpers.template import Template
from homeassistant.helpers.trigger_template_entity import (
CONF_AVAILABILITY,
CONF_PICTURE,
TEMPLATE_SENSOR_BASE_SCHEMA,
ManualTriggerSensorEntity,
)
from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
from .const import (
CONF_ACCEPT_ERRORS,
CONF_AUTH_KEY,
CONF_AUTH_PROTOCOL,
CONF_BASEOID,
CONF_COMMUNITY,
CONF_DEFAULT_VALUE,
CONF_PRIV_KEY,
CONF_PRIV_PROTOCOL,
CONF_VERSION,
DEFAULT_AUTH_PROTOCOL,
DEFAULT_COMMUNITY,
DEFAULT_HOST,
DEFAULT_NAME,
DEFAULT_PORT,
DEFAULT_PRIV_PROTOCOL,
DEFAULT_TIMEOUT,
DEFAULT_VERSION,
MAP_AUTH_PROTOCOLS,
MAP_PRIV_PROTOCOLS,
SNMP_VERSIONS,
)
from .util import async_create_request_cmd_args
_LOGGER = logging.getLogger(__name__)
SCAN_INTERVAL = timedelta(seconds=10)
TRIGGER_ENTITY_OPTIONS = (
CONF_AVAILABILITY,
CONF_DEVICE_CLASS,
CONF_ICON,
CONF_PICTURE,
CONF_UNIQUE_ID,
CONF_STATE_CLASS,
CONF_UNIT_OF_MEASUREMENT,
)
PLATFORM_SCHEMA = SENSOR_PLATFORM_SCHEMA.extend(
{
vol.Required(CONF_BASEOID): cv.string,
vol.Optional(CONF_ACCEPT_ERRORS, default=False): cv.boolean,
vol.Optional(CONF_COMMUNITY, default=DEFAULT_COMMUNITY): cv.string,
vol.Optional(CONF_DEFAULT_VALUE): cv.string,
vol.Optional(CONF_HOST, default=DEFAULT_HOST): cv.string,
vol.Optional(CONF_PORT, default=DEFAULT_PORT): cv.port,
vol.Optional(CONF_VALUE_TEMPLATE): cv.template,
vol.Optional(CONF_VERSION, default=DEFAULT_VERSION): vol.In(SNMP_VERSIONS),
vol.Optional(CONF_USERNAME): cv.string,
vol.Optional(CONF_AUTH_KEY): cv.string,
vol.Optional(CONF_AUTH_PROTOCOL, default=DEFAULT_AUTH_PROTOCOL): vol.In(
MAP_AUTH_PROTOCOLS
),
vol.Optional(CONF_PRIV_KEY): cv.string,
vol.Optional(CONF_PRIV_PROTOCOL, default=DEFAULT_PRIV_PROTOCOL): vol.In(
MAP_PRIV_PROTOCOLS
),
}
).extend(TEMPLATE_SENSOR_BASE_SCHEMA.schema)
async def async_setup_platform(
hass: HomeAssistant,
config: ConfigType,
async_add_entities: AddEntitiesCallback,
discovery_info: DiscoveryInfoType | None = None,
) -> None:
"""Set up the SNMP sensor."""
host = config.get(CONF_HOST)
port = config.get(CONF_PORT)
community = config.get(CONF_COMMUNITY)
baseoid: str = config[CONF_BASEOID]
version = config[CONF_VERSION]
username = config.get(CONF_USERNAME)
authkey = config.get(CONF_AUTH_KEY)
authproto = config[CONF_AUTH_PROTOCOL]
privkey = config.get(CONF_PRIV_KEY)
privproto = config[CONF_PRIV_PROTOCOL]
accept_errors = config.get(CONF_ACCEPT_ERRORS)
default_value = config.get(CONF_DEFAULT_VALUE)
try:
# Try IPv4 first.
target = UdpTransportTarget((host, port), timeout=DEFAULT_TIMEOUT)
except PySnmpError:
# Then try IPv6.
try:
target = Udp6TransportTarget((host, port), timeout=DEFAULT_TIMEOUT)
except PySnmpError as err:
_LOGGER.error("Invalid SNMP host: %s", err)
return
if version == "3":
if not authkey:
authproto = "none"
if not privkey:
privproto = "none"
auth_data = UsmUserData(
username,
authKey=authkey or None,
privKey=privkey or None,
authProtocol=getattr(hlapi, MAP_AUTH_PROTOCOLS[authproto]),
privProtocol=getattr(hlapi, MAP_PRIV_PROTOCOLS[privproto]),
)
else:
auth_data = CommunityData(community, mpModel=SNMP_VERSIONS[version])
request_args = await async_create_request_cmd_args(hass, auth_data, target, baseoid)
get_result = await getCmd(*request_args)
errindication, _, _, _ = get_result
if errindication and not accept_errors:
_LOGGER.error(
"Please check the details in the configuration file: %s",
errindication,
)
return
name = config.get(CONF_NAME, Template(DEFAULT_NAME, hass))
trigger_entity_config = {CONF_NAME: name}
for key in TRIGGER_ENTITY_OPTIONS:
if key not in config:
continue
trigger_entity_config[key] = config[key]
value_template: Template | None = config.get(CONF_VALUE_TEMPLATE)
data = SnmpData(request_args, baseoid, accept_errors, default_value)
async_add_entities([SnmpSensor(hass, data, trigger_entity_config, value_template)])
class SnmpSensor(ManualTriggerSensorEntity):
"""Representation of a SNMP sensor."""
_attr_should_poll = True
def __init__(
self,
hass: HomeAssistant,
data: SnmpData,
config: ConfigType,
value_template: Template | None,
) -> None:
"""Initialize the sensor."""
super().__init__(hass, config)
self.data = data
self._state = None
self._value_template = value_template
async def async_added_to_hass(self) -> None:
"""Handle adding to Home Assistant."""
await super().async_added_to_hass()
await self.async_update()
async def async_update(self) -> None:
"""Get the latest data and updates the states."""
await self.data.async_update()
raw_value = self.data.value
if (value := self.data.value) is None:
value = STATE_UNKNOWN
elif self._value_template is not None:
value = self._value_template.async_render_with_possible_json_value(
value, STATE_UNKNOWN
)
self._attr_native_value = value
self._process_manual_data(raw_value)
class SnmpData:
"""Get the latest data and update the states."""
def __init__(self, request_args, baseoid, accept_errors, default_value) -> None:
"""Initialize the data object."""
self._request_args = request_args
self._baseoid = baseoid
self._accept_errors = accept_errors
self._default_value = default_value
self.value = None
async def async_update(self):
"""Get the latest data from the remote SNMP capable host."""
get_result = await getCmd(*self._request_args)
errindication, errstatus, errindex, restable = get_result
if errindication and not self._accept_errors:
_LOGGER.error("SNMP error: %s", errindication)
elif errstatus and not self._accept_errors:
_LOGGER.error(
"SNMP error: %s at %s",
errstatus.prettyPrint(),
restable[-1][int(errindex) - 1] if errindex else "?",
)
elif (errindication or errstatus) and self._accept_errors:
self.value = self._default_value
else:
for resrow in restable:
self.value = self._decode_value(resrow[-1])
def _decode_value(self, value):
"""Decode the different results we could get into strings."""
_LOGGER.debug(
"SNMP OID %s received type=%s and data %s",
self._baseoid,
type(value),
value,
)
if isinstance(value, NoSuchObject):
_LOGGER.error(
"SNMP error for OID %s: No Such Object currently exists at this OID",
self._baseoid,
)
return self._default_value
if isinstance(value, Opaque):
# Float data type is not supported by the pyasn1 library,
# so we need to decode this type ourselves based on:
# https://tools.ietf.org/html/draft-perkins-opaque-01
if bytes(value).startswith(b"\x9f\x78"):
return str(unpack("!f", bytes(value)[3:])[0])
# Otherwise Opaque types should be asn1 encoded
try:
decoded_value, _ = decoder.decode(bytes(value))
return str(decoded_value)
except Exception as decode_exception: # noqa: BLE001
_LOGGER.error(
"SNMP error in decoding opaque type: %s", decode_exception
)
return self._default_value
return str(value)