1 /** 2 * Copyright © 2020 IBM Corporation 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #pragma once 17 18 #include "sdbusplus.hpp" 19 20 #include <fmt/format.h> 21 22 #include <nlohmann/json.hpp> 23 #include <phosphor-logging/log.hpp> 24 #include <sdbusplus/bus.hpp> 25 #include <sdeventplus/source/signal.hpp> 26 27 #include <filesystem> 28 #include <fstream> 29 30 namespace phosphor::fan 31 { 32 33 namespace fs = std::filesystem; 34 using json = nlohmann::json; 35 using namespace phosphor::logging; 36 37 constexpr auto confOverridePath = "/etc/phosphor-fan-presence"; 38 constexpr auto confBasePath = "/usr/share/phosphor-fan-presence"; 39 constexpr auto confCompatServ = "xyz.openbmc_project.EntityManager"; 40 constexpr auto confCompatIntf = 41 "xyz.openbmc_project.Configuration.IBMCompatibleSystem"; 42 constexpr auto confCompatProp = "Names"; 43 44 class JsonConfig 45 { 46 public: 47 /** 48 * @brief Get the object paths with the compatible interface 49 * 50 * Retrieve all the object paths implementing the compatible interface for 51 * configuration file loading. 52 */ 53 static auto& getCompatObjPaths() __attribute__((pure)) 54 { 55 static auto paths = util::SDBusPlus::getSubTreePathsRaw( 56 util::SDBusPlus::getBus(), "/", confCompatIntf, 0); 57 return paths; 58 } 59 60 /** 61 * @brief Constructor 62 * 63 * Attempts to set the list of compatible values from the compatible 64 * interface and call the fan app's function to load its config file(s). If 65 * the compatible interface is not found, it subscribes to the 66 * interfacesAdded signal for that interface on the compatible service 67 * defined above. 68 * 69 * @param[in] func - Fan app function to call to load its config file(s) 70 */ 71 JsonConfig(std::function<void()> func) : _loadFunc(func) 72 { 73 _match = std::make_unique<sdbusplus::server::match::match>( 74 util::SDBusPlus::getBus(), 75 sdbusplus::bus::match::rules::interfacesAdded() + 76 sdbusplus::bus::match::rules::sender(confCompatServ), 77 std::bind(&JsonConfig::compatIntfAdded, this, 78 std::placeholders::_1)); 79 80 auto compatObjPaths = getCompatObjPaths(); 81 if (!compatObjPaths.empty()) 82 { 83 for (auto& path : compatObjPaths) 84 { 85 try 86 { 87 // Retrieve json config compatible relative path 88 // locations (last one found will be what's used if more 89 // than one dbus object implementing the comptaible 90 // interface exists). 91 _confCompatValues = 92 util::SDBusPlus::getProperty<std::vector<std::string>>( 93 util::SDBusPlus::getBus(), path, confCompatIntf, 94 confCompatProp); 95 } 96 catch (const util::DBusError&) 97 { 98 // Compatible property unavailable on this dbus object 99 // path's compatible interface, ignore 100 } 101 } 102 _loadFunc(); 103 _match.reset(); 104 } 105 else 106 { 107 // Check if required config(s) are found not needing the 108 // compatible interface, otherwise this is intended to catch the 109 // exception thrown by the getConfFile function when the 110 // required config file was not found. This would then result in 111 // waiting for the compatible interfacesAdded signal 112 try 113 { 114 _loadFunc(); 115 _match.reset(); 116 } 117 catch (const std::runtime_error&) 118 { 119 // Wait for compatible interfacesAdded signal 120 } 121 } 122 } 123 124 /** 125 * @brief InterfacesAdded callback function for the compatible interface. 126 * 127 * @param[in] msg - The D-Bus message contents 128 * 129 * If the compatible interface is found, it uses the compatible property on 130 * the interface to set the list of compatible values to be used when 131 * attempting to get a configuration file. Once the list of compatible 132 * values has been updated, it calls the load function. 133 */ 134 void compatIntfAdded(sdbusplus::message::message& msg) 135 { 136 sdbusplus::message::object_path op; 137 std::map<std::string, 138 std::map<std::string, std::variant<std::vector<std::string>>>> 139 intfProps; 140 141 msg.read(op, intfProps); 142 143 if (intfProps.find(confCompatIntf) == intfProps.end()) 144 { 145 return; 146 } 147 148 const auto& props = intfProps.at(confCompatIntf); 149 // Only one dbus object with the compatible interface is used at a time 150 _confCompatValues = 151 std::get<std::vector<std::string>>(props.at(confCompatProp)); 152 _loadFunc(); 153 } 154 155 /** 156 * Get the json configuration file. The first location found to contain 157 * the json config file for the given fan application is used from the 158 * following locations in order. 159 * 1.) From the confOverridePath location 160 * 2.) From the default confBasePath location 161 * 3.) From config file found using an entry from a list obtained from an 162 * interface's property as a relative path extension on the base path where: 163 * interface = Interface set in confCompatIntf with the property 164 * property = Property set in confCompatProp containing a list of 165 * subdirectories in priority order to find a config 166 * 167 * @brief Get the configuration file to be used 168 * 169 * @param[in] bus - The dbus bus object 170 * @param[in] appName - The phosphor-fan-presence application name 171 * @param[in] fileName - Application's configuration file's name 172 * @param[in] isOptional - Config file is optional, default to 'false' 173 * 174 * @return filesystem path 175 * The filesystem path to the configuration file to use 176 */ 177 static const fs::path getConfFile(sdbusplus::bus::bus& bus, 178 const std::string& appName, 179 const std::string& fileName, 180 bool isOptional = false) 181 { 182 // Check override location 183 fs::path confFile = fs::path{confOverridePath} / appName / fileName; 184 if (fs::exists(confFile)) 185 { 186 return confFile; 187 } 188 189 // If the default file is there, use it 190 confFile = fs::path{confBasePath} / appName / fileName; 191 if (fs::exists(confFile)) 192 { 193 return confFile; 194 } 195 196 // Look for a config file at each entry relative to the base 197 // path and use the first one found 198 auto it = std::find_if( 199 _confCompatValues.begin(), _confCompatValues.end(), 200 [&confFile, &appName, &fileName](const auto& value) { 201 confFile = fs::path{confBasePath} / appName / value / fileName; 202 return fs::exists(confFile); 203 }); 204 if (it == _confCompatValues.end()) 205 { 206 confFile.clear(); 207 } 208 209 if (!isOptional && confFile.empty() && !_confCompatValues.empty()) 210 { 211 log<level::ERR>(fmt::format("Could not find fan {} conf file {}", 212 appName, fileName) 213 .c_str()); 214 } 215 216 if (confFile.empty() && !isOptional) 217 { 218 throw std::runtime_error("No JSON config file found"); 219 } 220 221 return confFile; 222 } 223 224 /** 225 * @brief Load the JSON config file 226 * 227 * @param[in] confFile - File system path of the configuration file to load 228 * 229 * @return Parsed JSON object 230 * The parsed JSON configuration file object 231 */ 232 static const json load(const fs::path& confFile) 233 { 234 std::ifstream file; 235 json jsonConf; 236 237 if (!confFile.empty() && fs::exists(confFile)) 238 { 239 log<level::INFO>( 240 fmt::format("Loading configuration from {}", confFile.string()) 241 .c_str()); 242 file.open(confFile); 243 try 244 { 245 // Enable ignoring `//` or `/* */` comments 246 jsonConf = json::parse(file, nullptr, true, true); 247 } 248 catch (std::exception& e) 249 { 250 log<level::ERR>( 251 fmt::format( 252 "Failed to parse JSON config file: {}, error: {}", 253 confFile.string(), e.what()) 254 .c_str()); 255 throw std::runtime_error( 256 fmt::format( 257 "Failed to parse JSON config file: {}, error: {}", 258 confFile.string(), e.what()) 259 .c_str()); 260 } 261 } 262 else 263 { 264 log<level::ERR>(fmt::format("Unable to open JSON config file: {}", 265 confFile.string()) 266 .c_str()); 267 throw std::runtime_error( 268 fmt::format("Unable to open JSON config file: {}", 269 confFile.string()) 270 .c_str()); 271 } 272 273 return jsonConf; 274 } 275 276 private: 277 /* Load function to call for a fan app to load its config file(s). */ 278 std::function<void()> _loadFunc; 279 280 /** 281 * @brief The interfacesAdded match that is used to wait 282 * for the IBMCompatibleSystem interface to show up. 283 */ 284 std::unique_ptr<sdbusplus::server::match::match> _match; 285 286 /** 287 * @brief List of compatible values from the compatible interface 288 * 289 * Only supports a single instance of the compatible interface on a dbus 290 * object. If more than one dbus object exists with the compatible 291 * interface, the last one found will be the list of compatible values used. 292 */ 293 inline static std::vector<std::string> _confCompatValues; 294 }; 295 296 } // namespace phosphor::fan 297