dbus-sdr/sdrutils.cpp - openbmc/phosphor-host-ipmid - Gitiles

 /*
 // Copyright (c) 2018 Intel 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 "dbus-sdr/sdrutils.hpp"

 namespace details
 {
 uint16_t getSensorSubtree(std::shared_ptr<SensorSubTree>& subtree)
 {
     static std::shared_ptr<SensorSubTree> sensorTreePtr;
     static uint16_t sensorUpdatedIndex = 0;
     std::shared_ptr<sdbusplus::asio::connection> dbus = getSdBus();
     static sdbusplus::bus::match::match sensorAdded(
         *dbus,
         "type='signal',member='InterfacesAdded',arg0path='/xyz/openbmc_project/"
         "sensors/'",
         [](sdbusplus::message::message& m) { sensorTreePtr.reset(); });

     static sdbusplus::bus::match::match sensorRemoved(
         *dbus,
         "type='signal',member='InterfacesRemoved',arg0path='/xyz/"
         "openbmc_project/sensors/'",
         [](sdbusplus::message::message& m) { sensorTreePtr.reset(); });

     if (sensorTreePtr)
     {
         subtree = sensorTreePtr;
         return sensorUpdatedIndex;
     }

     sensorTreePtr = std::make_shared<SensorSubTree>();

     auto mapperCall =
         dbus->new_method_call("xyz.openbmc_project.ObjectMapper",
                               "/xyz/openbmc_project/object_mapper",
                               "xyz.openbmc_project.ObjectMapper", "GetSubTree");
     static constexpr const int32_t depth = 2;
     static constexpr std::array<const char*, 3> interfaces = {
         "xyz.openbmc_project.Sensor.Value",
         "xyz.openbmc_project.Sensor.Threshold.Warning",
         "xyz.openbmc_project.Sensor.Threshold.Critical"};
     mapperCall.append("/xyz/openbmc_project/sensors", depth, interfaces);

     try
     {
         auto mapperReply = dbus->call(mapperCall);
         mapperReply.read(*sensorTreePtr);
     }
     catch (sdbusplus::exception_t& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
         return sensorUpdatedIndex;
     }
     subtree = sensorTreePtr;
     sensorUpdatedIndex++;
     return sensorUpdatedIndex;
 }

 bool getSensorNumMap(std::shared_ptr<SensorNumMap>& sensorNumMap)
 {
     static std::shared_ptr<SensorNumMap> sensorNumMapPtr;
     bool sensorNumMapUpated = false;
     static uint16_t prevSensorUpdatedIndex = 0;
     std::shared_ptr<SensorSubTree> sensorTree;
     uint16_t curSensorUpdatedIndex = details::getSensorSubtree(sensorTree);
     if (!sensorTree)
     {
         return sensorNumMapUpated;
     }

     if ((curSensorUpdatedIndex == prevSensorUpdatedIndex) && sensorNumMapPtr)
     {
         sensorNumMap = sensorNumMapPtr;
         return sensorNumMapUpated;
     }
     prevSensorUpdatedIndex = curSensorUpdatedIndex;

     sensorNumMapPtr = std::make_shared<SensorNumMap>();

     uint16_t sensorNum = 0;
     uint16_t sensorIndex = 0;
     for (const auto& sensor : *sensorTree)
     {
         sensorNumMapPtr->insert(
             SensorNumMap::value_type(sensorNum, sensor.first));
         sensorIndex++;
         if (sensorIndex == maxSensorsPerLUN)
         {
             sensorIndex = lun1Sensor0;
         }
         else if (sensorIndex == (lun1Sensor0 | maxSensorsPerLUN))
         {
             // Skip assigning LUN 0x2 any sensors
             sensorIndex = lun3Sensor0;
         }
         else if (sensorIndex == (lun3Sensor0 | maxSensorsPerLUN))
         {
             // this is an error, too many IPMI sensors
             throw std::out_of_range("Maximum number of IPMI sensors exceeded.");
         }
         sensorNum = sensorIndex;
     }
     sensorNumMap = sensorNumMapPtr;
     sensorNumMapUpated = true;
     return sensorNumMapUpated;
 }
 } // namespace details

 bool getSensorSubtree(SensorSubTree& subtree)
 {
     std::shared_ptr<SensorSubTree> sensorTree;
     details::getSensorSubtree(sensorTree);
     if (!sensorTree)
     {
         return false;
     }

     subtree = *sensorTree;
     return true;
 }

 std::string getSensorTypeStringFromPath(const std::string& path)
 {
     // get sensor type string from path, path is defined as
     // /xyz/openbmc_project/sensors/<type>/label
     size_t typeEnd = path.rfind("/");
     if (typeEnd == std::string::npos)
     {
         return path;
     }
     size_t typeStart = path.rfind("/", typeEnd - 1);
     if (typeStart == std::string::npos)
     {
         return path;
     }
     // Start at the character after the '/'
     typeStart++;
     return path.substr(typeStart, typeEnd - typeStart);
 }

 uint8_t getSensorTypeFromPath(const std::string& path)
 {
     uint8_t sensorType = 0;
     std::string type = getSensorTypeStringFromPath(path);
     auto findSensor = sensorTypes.find(type.c_str());
     if (findSensor != sensorTypes.end())
     {
         sensorType = static_cast<uint8_t>(findSensor->second);
     } // else default 0x0 RESERVED

     return sensorType;
 }

 uint16_t getSensorNumberFromPath(const std::string& path)
 {
     std::shared_ptr<SensorNumMap> sensorNumMapPtr;
     details::getSensorNumMap(sensorNumMapPtr);
     if (!sensorNumMapPtr)
     {
         return invalidSensorNumber;
     }

     try
     {
         return sensorNumMapPtr->right.at(path);
     }
     catch (std::out_of_range& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
         return invalidSensorNumber;
     }
 }

 uint8_t getSensorEventTypeFromPath(const std::string& path)
 {
     // TODO: Add support for additional reading types as needed
     return 0x1; // reading type = threshold
 }

 std::string getPathFromSensorNumber(uint16_t sensorNum)
 {
     std::shared_ptr<SensorNumMap> sensorNumMapPtr;
     details::getSensorNumMap(sensorNumMapPtr);
     if (!sensorNumMapPtr)
     {
         return std::string();
     }

     try
     {
         return sensorNumMapPtr->left.at(sensorNum);
     }
     catch (std::out_of_range& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
         return std::string();
     }
 }

 namespace ipmi
 {

 std::map<std::string, std::vector<std::string>>
     getObjectInterfaces(const char* path)
 {
     std::map<std::string, std::vector<std::string>> interfacesResponse;
     std::vector<std::string> interfaces;
     std::shared_ptr<sdbusplus::asio::connection> dbus = getSdBus();

     sdbusplus::message::message getObjectMessage =
         dbus->new_method_call("xyz.openbmc_project.ObjectMapper",
                               "/xyz/openbmc_project/object_mapper",
                               "xyz.openbmc_project.ObjectMapper", "GetObject");
     getObjectMessage.append(path, interfaces);

     try
     {
         sdbusplus::message::message response = dbus->call(getObjectMessage);
         response.read(interfacesResponse);
     }
     catch (const std::exception& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(
             "Failed to GetObject", phosphor::logging::entry("PATH=%s", path),
             phosphor::logging::entry("WHAT=%s", e.what()));
     }

     return interfacesResponse;
 }

 std::map<std::string, Value> getEntityManagerProperties(const char* path,
                                                         const char* interface)
 {
     std::map<std::string, Value> properties;
     std::shared_ptr<sdbusplus::asio::connection> dbus = getSdBus();

     sdbusplus::message::message getProperties =
         dbus->new_method_call("xyz.openbmc_project.EntityManager", path,
                               "org.freedesktop.DBus.Properties", "GetAll");
     getProperties.append(interface);

     try
     {
         sdbusplus::message::message response = dbus->call(getProperties);
         response.read(properties);
     }
     catch (const std::exception& e)
     {
         phosphor::logging::log<phosphor::logging::level::ERR>(
             "Failed to GetAll", phosphor::logging::entry("PATH=%s", path),
             phosphor::logging::entry("INTF=%s", interface),
             phosphor::logging::entry("WHAT=%s", e.what()));
     }

     return properties;
 }

 const std::string* getSensorConfigurationInterface(
     const std::map<std::string, std::vector<std::string>>&
         sensorInterfacesResponse)
 {
     auto entityManagerService =
         sensorInterfacesResponse.find("xyz.openbmc_project.EntityManager");
     if (entityManagerService == sensorInterfacesResponse.end())
     {
         return nullptr;
     }

     // Find the fan configuration first (fans can have multiple configuration
     // interfaces).
     for (const auto& entry : entityManagerService->second)
     {
         if (entry == "xyz.openbmc_project.Configuration.AspeedFan" ||
             entry == "xyz.openbmc_project.Configuration.I2CFan" ||
             entry == "xyz.openbmc_project.Configuration.NuvotonFan")
         {
             return &entry;
         }
     }

     for (const auto& entry : entityManagerService->second)
     {
         if (boost::algorithm::starts_with(entry,
                                           "xyz.openbmc_project.Configuration."))
         {
             return &entry;
         }
     }

     return nullptr;
 }

 // Follow Association properties for Sensor back to the Board dbus object to
 // check for an EntityId and EntityInstance property.
 void updateIpmiFromAssociation(const std::string& path,
                                const DbusInterfaceMap& sensorMap,
                                uint8_t& entityId, uint8_t& entityInstance)
 {
     namespace fs = std::filesystem;

     auto sensorAssociationObject =
         sensorMap.find("xyz.openbmc_project.Association.Definitions");
     if (sensorAssociationObject == sensorMap.end())
     {
         if constexpr (debug)
         {
             std::fprintf(stderr, "path=%s, no association interface found\n",
                          path.c_str());
         }

         return;
     }

     auto associationObject =
         sensorAssociationObject->second.find("Associations");
     if (associationObject == sensorAssociationObject->second.end())
     {
         if constexpr (debug)
         {
             std::fprintf(stderr, "path=%s, no association records found\n",
                          path.c_str());
         }

         return;
     }

     std::vector<Association> associationValues =
         std::get<std::vector<Association>>(associationObject->second);

     // loop through the Associations looking for the right one:
     for (const auto& entry : associationValues)
     {
         // forward, reverse, endpoint
         const std::string& forward = std::get<0>(entry);
         const std::string& reverse = std::get<1>(entry);
         const std::string& endpoint = std::get<2>(entry);

         // We only currently concern ourselves with chassis+all_sensors.
         if (!(forward == "chassis" && reverse == "all_sensors"))
         {
             continue;
         }

         // the endpoint is the board entry provided by
         // Entity-Manager. so let's grab its properties if it has
         // the right interface.

         // just try grabbing the properties first.
         std::map<std::string, Value> ipmiProperties =
             getEntityManagerProperties(
                 endpoint.c_str(),
                 "xyz.openbmc_project.Inventory.Decorator.Ipmi");

         auto entityIdProp = ipmiProperties.find("EntityId");
         auto entityInstanceProp = ipmiProperties.find("EntityInstance");
         if (entityIdProp != ipmiProperties.end())
         {
             entityId =
                 static_cast<uint8_t>(std::get<uint64_t>(entityIdProp->second));
         }
         if (entityInstanceProp != ipmiProperties.end())
         {
             entityInstance = static_cast<uint8_t>(
                 std::get<uint64_t>(entityInstanceProp->second));
         }

         // Now check the entity-manager entry for this sensor to see
         // if it has its own value and use that instead.
         //
         // In theory, checking this first saves us from checking
         // both, except in most use-cases identified, there won't be
         // a per sensor override, so we need to always check both.
         std::string sensorNameFromPath = fs::path(path).filename();

         std::string sensorConfigPath = endpoint + "/" + sensorNameFromPath;

         // Download the interfaces for the sensor from
         // Entity-Manager to find the name of the configuration
         // interface.
         std::map<std::string, std::vector<std::string>>
             sensorInterfacesResponse =
                 getObjectInterfaces(sensorConfigPath.c_str());

         const std::string* configurationInterface =
             getSensorConfigurationInterface(sensorInterfacesResponse);

         // We didnt' find a configuration interface for this sensor, but we
         // followed the Association property to get here, so we're done
         // searching.
         if (!configurationInterface)
         {
             break;
         }

         // We found a configuration interface.
         std::map<std::string, Value> configurationProperties =
             getEntityManagerProperties(sensorConfigPath.c_str(),
                                        configurationInterface->c_str());

         entityIdProp = configurationProperties.find("EntityId");
         entityInstanceProp = configurationProperties.find("EntityInstance");
         if (entityIdProp != configurationProperties.end())
         {
             entityId =
                 static_cast<uint8_t>(std::get<uint64_t>(entityIdProp->second));
         }
         if (entityInstanceProp != configurationProperties.end())
         {
             entityInstance = static_cast<uint8_t>(
                 std::get<uint64_t>(entityInstanceProp->second));
         }

         // stop searching Association records.
         break;
     } // end for Association vectors.

     if constexpr (debug)
     {
         std::fprintf(stderr, "path=%s, entityId=%d, entityInstance=%d\n",
                      path.c_str(), entityId, entityInstance);
     }
 }

 } // namespace ipmi
	/*
	// Copyright (c) 2018 Intel 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 "dbus-sdr/sdrutils.hpp"

	namespace details
	{
	uint16_t getSensorSubtree(std::shared_ptr<SensorSubTree>& subtree)
	{
	static std::shared_ptr<SensorSubTree> sensorTreePtr;
	static uint16_t sensorUpdatedIndex = 0;
	std::shared_ptr<sdbusplus::asio::connection> dbus = getSdBus();
	static sdbusplus::bus::match::match sensorAdded(
	*dbus,
	"type='signal',member='InterfacesAdded',arg0path='/xyz/openbmc_project/"
	"sensors/'",
	[](sdbusplus::message::message& m) { sensorTreePtr.reset(); });

	static sdbusplus::bus::match::match sensorRemoved(
	*dbus,
	"type='signal',member='InterfacesRemoved',arg0path='/xyz/"
	"openbmc_project/sensors/'",
	[](sdbusplus::message::message& m) { sensorTreePtr.reset(); });

	if (sensorTreePtr)
	{
	subtree = sensorTreePtr;
	return sensorUpdatedIndex;
	}

	sensorTreePtr = std::make_shared<SensorSubTree>();

	auto mapperCall =
	dbus->new_method_call("xyz.openbmc_project.ObjectMapper",
	"/xyz/openbmc_project/object_mapper",
	"xyz.openbmc_project.ObjectMapper", "GetSubTree");
	static constexpr const int32_t depth = 2;
	static constexpr std::array<const char*, 3> interfaces = {
	"xyz.openbmc_project.Sensor.Value",
	"xyz.openbmc_project.Sensor.Threshold.Warning",
	"xyz.openbmc_project.Sensor.Threshold.Critical"};
	mapperCall.append("/xyz/openbmc_project/sensors", depth, interfaces);

	try
	{
	auto mapperReply = dbus->call(mapperCall);
	mapperReply.read(*sensorTreePtr);
	}
	catch (sdbusplus::exception_t& e)
	{
	phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
	return sensorUpdatedIndex;
	}
	subtree = sensorTreePtr;
	sensorUpdatedIndex++;
	return sensorUpdatedIndex;
	}

	bool getSensorNumMap(std::shared_ptr<SensorNumMap>& sensorNumMap)
	{
	static std::shared_ptr<SensorNumMap> sensorNumMapPtr;
	bool sensorNumMapUpated = false;
	static uint16_t prevSensorUpdatedIndex = 0;
	std::shared_ptr<SensorSubTree> sensorTree;
	uint16_t curSensorUpdatedIndex = details::getSensorSubtree(sensorTree);
	if (!sensorTree)
	{
	return sensorNumMapUpated;
	}

	if ((curSensorUpdatedIndex == prevSensorUpdatedIndex) && sensorNumMapPtr)
	{
	sensorNumMap = sensorNumMapPtr;
	return sensorNumMapUpated;
	}
	prevSensorUpdatedIndex = curSensorUpdatedIndex;

	sensorNumMapPtr = std::make_shared<SensorNumMap>();

	uint16_t sensorNum = 0;
	uint16_t sensorIndex = 0;
	for (const auto& sensor : *sensorTree)
	{
	sensorNumMapPtr->insert(
	SensorNumMap::value_type(sensorNum, sensor.first));
	sensorIndex++;
	if (sensorIndex == maxSensorsPerLUN)
	{
	sensorIndex = lun1Sensor0;
	}
	else if (sensorIndex == (lun1Sensor0 \| maxSensorsPerLUN))
	{
	// Skip assigning LUN 0x2 any sensors
	sensorIndex = lun3Sensor0;
	}
	else if (sensorIndex == (lun3Sensor0 \| maxSensorsPerLUN))
	{
	// this is an error, too many IPMI sensors
	throw std::out_of_range("Maximum number of IPMI sensors exceeded.");
	}
	sensorNum = sensorIndex;
	}
	sensorNumMap = sensorNumMapPtr;
	sensorNumMapUpated = true;
	return sensorNumMapUpated;
	}
	} // namespace details

	bool getSensorSubtree(SensorSubTree& subtree)
	{
	std::shared_ptr<SensorSubTree> sensorTree;
	details::getSensorSubtree(sensorTree);
	if (!sensorTree)
	{
	return false;
	}

	subtree = *sensorTree;
	return true;
	}

	std::string getSensorTypeStringFromPath(const std::string& path)
	{
	// get sensor type string from path, path is defined as
	// /xyz/openbmc_project/sensors/<type>/label
	size_t typeEnd = path.rfind("/");
	if (typeEnd == std::string::npos)
	{
	return path;
	}
	size_t typeStart = path.rfind("/", typeEnd - 1);
	if (typeStart == std::string::npos)
	{
	return path;
	}
	// Start at the character after the '/'
	typeStart++;
	return path.substr(typeStart, typeEnd - typeStart);
	}

	uint8_t getSensorTypeFromPath(const std::string& path)
	{
	uint8_t sensorType = 0;
	std::string type = getSensorTypeStringFromPath(path);
	auto findSensor = sensorTypes.find(type.c_str());
	if (findSensor != sensorTypes.end())
	{
	sensorType = static_cast<uint8_t>(findSensor->second);
	} // else default 0x0 RESERVED

	return sensorType;
	}

	uint16_t getSensorNumberFromPath(const std::string& path)
	{
	std::shared_ptr<SensorNumMap> sensorNumMapPtr;
	details::getSensorNumMap(sensorNumMapPtr);
	if (!sensorNumMapPtr)
	{
	return invalidSensorNumber;
	}

	try
	{
	return sensorNumMapPtr->right.at(path);
	}
	catch (std::out_of_range& e)
	{
	phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
	return invalidSensorNumber;
	}
	}

	uint8_t getSensorEventTypeFromPath(const std::string& path)
	{
	// TODO: Add support for additional reading types as needed
	return 0x1; // reading type = threshold
	}

	std::string getPathFromSensorNumber(uint16_t sensorNum)
	{
	std::shared_ptr<SensorNumMap> sensorNumMapPtr;
	details::getSensorNumMap(sensorNumMapPtr);
	if (!sensorNumMapPtr)
	{
	return std::string();
	}

	try
	{
	return sensorNumMapPtr->left.at(sensorNum);
	}
	catch (std::out_of_range& e)
	{
	phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
	return std::string();
	}
	}

	namespace ipmi
	{

	std::map<std::string, std::vector<std::string>>
	getObjectInterfaces(const char* path)
	{
	std::map<std::string, std::vector<std::string>> interfacesResponse;
	std::vector<std::string> interfaces;
	std::shared_ptr<sdbusplus::asio::connection> dbus = getSdBus();

	sdbusplus::message::message getObjectMessage =
	dbus->new_method_call("xyz.openbmc_project.ObjectMapper",
	"/xyz/openbmc_project/object_mapper",
	"xyz.openbmc_project.ObjectMapper", "GetObject");
	getObjectMessage.append(path, interfaces);

	try
	{
	sdbusplus::message::message response = dbus->call(getObjectMessage);
	response.read(interfacesResponse);
	}
	catch (const std::exception& e)
	{
	phosphor::logging::log<phosphor::logging::level::ERR>(
	"Failed to GetObject", phosphor::logging::entry("PATH=%s", path),
	phosphor::logging::entry("WHAT=%s", e.what()));
	}

	return interfacesResponse;
	}

	std::map<std::string, Value> getEntityManagerProperties(const char* path,
	const char* interface)
	{
	std::map<std::string, Value> properties;
	std::shared_ptr<sdbusplus::asio::connection> dbus = getSdBus();

	sdbusplus::message::message getProperties =
	dbus->new_method_call("xyz.openbmc_project.EntityManager", path,
	"org.freedesktop.DBus.Properties", "GetAll");
	getProperties.append(interface);

	try
	{
	sdbusplus::message::message response = dbus->call(getProperties);
	response.read(properties);
	}
	catch (const std::exception& e)
	{
	phosphor::logging::log<phosphor::logging::level::ERR>(
	"Failed to GetAll", phosphor::logging::entry("PATH=%s", path),
	phosphor::logging::entry("INTF=%s", interface),
	phosphor::logging::entry("WHAT=%s", e.what()));
	}

	return properties;
	}

	const std::string* getSensorConfigurationInterface(
	const std::map<std::string, std::vector<std::string>>&
	sensorInterfacesResponse)
	{
	auto entityManagerService =
	sensorInterfacesResponse.find("xyz.openbmc_project.EntityManager");
	if (entityManagerService == sensorInterfacesResponse.end())
	{
	return nullptr;
	}

	// Find the fan configuration first (fans can have multiple configuration
	// interfaces).
	for (const auto& entry : entityManagerService->second)
	{
	if (entry == "xyz.openbmc_project.Configuration.AspeedFan" \|\|
	entry == "xyz.openbmc_project.Configuration.I2CFan" \|\|
	entry == "xyz.openbmc_project.Configuration.NuvotonFan")
	{
	return &entry;
	}
	}

	for (const auto& entry : entityManagerService->second)
	{
	if (boost::algorithm::starts_with(entry,
	"xyz.openbmc_project.Configuration."))
	{
	return &entry;
	}
	}

	return nullptr;
	}

	// Follow Association properties for Sensor back to the Board dbus object to
	// check for an EntityId and EntityInstance property.
	void updateIpmiFromAssociation(const std::string& path,
	const DbusInterfaceMap& sensorMap,
	uint8_t& entityId, uint8_t& entityInstance)
	{
	namespace fs = std::filesystem;

	auto sensorAssociationObject =
	sensorMap.find("xyz.openbmc_project.Association.Definitions");
	if (sensorAssociationObject == sensorMap.end())
	{
	if constexpr (debug)
	{
	std::fprintf(stderr, "path=%s, no association interface found\n",
	path.c_str());
	}

	return;
	}

	auto associationObject =
	sensorAssociationObject->second.find("Associations");
	if (associationObject == sensorAssociationObject->second.end())
	{
	if constexpr (debug)
	{
	std::fprintf(stderr, "path=%s, no association records found\n",
	path.c_str());
	}

	return;
	}

	std::vector<Association> associationValues =
	std::get<std::vector<Association>>(associationObject->second);

	// loop through the Associations looking for the right one:
	for (const auto& entry : associationValues)
	{
	// forward, reverse, endpoint
	const std::string& forward = std::get<0>(entry);
	const std::string& reverse = std::get<1>(entry);
	const std::string& endpoint = std::get<2>(entry);

	// We only currently concern ourselves with chassis+all_sensors.
	if (!(forward == "chassis" && reverse == "all_sensors"))
	{
	continue;
	}

	// the endpoint is the board entry provided by
	// Entity-Manager. so let's grab its properties if it has
	// the right interface.

	// just try grabbing the properties first.
	std::map<std::string, Value> ipmiProperties =
	getEntityManagerProperties(
	endpoint.c_str(),
	"xyz.openbmc_project.Inventory.Decorator.Ipmi");

	auto entityIdProp = ipmiProperties.find("EntityId");
	auto entityInstanceProp = ipmiProperties.find("EntityInstance");
	if (entityIdProp != ipmiProperties.end())
	{
	entityId =
	static_cast<uint8_t>(std::get<uint64_t>(entityIdProp->second));
	}
	if (entityInstanceProp != ipmiProperties.end())
	{
	entityInstance = static_cast<uint8_t>(
	std::get<uint64_t>(entityInstanceProp->second));
	}

	// Now check the entity-manager entry for this sensor to see
	// if it has its own value and use that instead.
	//
	// In theory, checking this first saves us from checking
	// both, except in most use-cases identified, there won't be
	// a per sensor override, so we need to always check both.
	std::string sensorNameFromPath = fs::path(path).filename();

	std::string sensorConfigPath = endpoint + "/" + sensorNameFromPath;

	// Download the interfaces for the sensor from
	// Entity-Manager to find the name of the configuration
	// interface.
	std::map<std::string, std::vector<std::string>>
	sensorInterfacesResponse =
	getObjectInterfaces(sensorConfigPath.c_str());

	const std::string* configurationInterface =
	getSensorConfigurationInterface(sensorInterfacesResponse);

	// We didnt' find a configuration interface for this sensor, but we
	// followed the Association property to get here, so we're done
	// searching.
	if (!configurationInterface)
	{
	break;
	}

	// We found a configuration interface.
	std::map<std::string, Value> configurationProperties =
	getEntityManagerProperties(sensorConfigPath.c_str(),
	configurationInterface->c_str());

	entityIdProp = configurationProperties.find("EntityId");
	entityInstanceProp = configurationProperties.find("EntityInstance");
	if (entityIdProp != configurationProperties.end())
	{
	entityId =
	static_cast<uint8_t>(std::get<uint64_t>(entityIdProp->second));
	}
	if (entityInstanceProp != configurationProperties.end())
	{
	entityInstance = static_cast<uint8_t>(
	std::get<uint64_t>(entityInstanceProp->second));
	}

	// stop searching Association records.
	break;
	} // end for Association vectors.

	if constexpr (debug)
	{
	std::fprintf(stderr, "path=%s, entityId=%d, entityInstance=%d\n",
	path.c_str(), entityId, entityInstance);
	}
	}

	} // namespace ipmi