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/**
* Copyright © 2020 IBM Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "presence_service.hpp"
#include "types.hpp"
#include "utility.hpp"
namespace phosphor::power::regulators
{
bool DBusPresenceService::isPresent(const std::string& inventoryPath)
{
// Initially assume hardware is not present
bool present{false};
// Try to find cached presence value
auto it = cache.find(inventoryPath);
if (it != cache.end())
{
present = it->second;
}
else
{
// Get presence from D-Bus interface/property
try
{
util::getProperty(INVENTORY_IFACE, PRESENT_PROP, inventoryPath,
INVENTORY_MGR_IFACE, bus, present);
}
catch (const sdbusplus::exception::SdBusError& e)
{
// If exception type is expected and indicates hardware not present
if (isExpectedException(e))
{
present = false;
}
else
{
// Re-throw unexpected exception
throw;
}
}
// Cache presence value
cache[inventoryPath] = present;
}
return present;
}
bool DBusPresenceService::isExpectedException(
const sdbusplus::exception::SdBusError& e)
{
// Initially assume exception is not one of the expected types
bool isExpected{false};
// If the D-Bus error name is set within the exception
if (e.name() != nullptr)
{
// Check if the error name is one of the expected values when hardware
// is not present.
//
// Sometimes the object path does not exist. Sometimes the object path
// exists, but it does not implement the D-Bus interface that contains
// the present property. Both of these cases result in exceptions.
//
// In the case where the interface is not implemented, the systemd
// documentation seems to indicate that the error name should be
// SD_BUS_ERROR_UNKNOWN_INTERFACE. However, in OpenBMC the
// SD_BUS_ERROR_UNKNOWN_PROPERTY error name can occur.
std::string name = e.name();
if ((name == SD_BUS_ERROR_UNKNOWN_OBJECT) ||
(name == SD_BUS_ERROR_UNKNOWN_INTERFACE) ||
(name == SD_BUS_ERROR_UNKNOWN_PROPERTY))
{
isExpected = true;
}
}
return isExpected;
}
} // namespace phosphor::power::regulators