1 /* 2 // Copyright (c) 2018 Intel 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 #ifndef BOOST_COROUTINES_NO_DEPRECATION_WARNING 19 // users should define this if they directly include boost/asio/spawn.hpp, 20 // but by defining it here, warnings won't cause problems with a compile 21 #define BOOST_COROUTINES_NO_DEPRECATION_WARNING 22 #endif 23 24 #include <boost/asio/async_result.hpp> 25 #include <boost/asio/io_context.hpp> 26 #include <boost/asio/posix/stream_descriptor.hpp> 27 #include <boost/asio/post.hpp> 28 #include <boost/asio/spawn.hpp> 29 #include <boost/callable_traits.hpp> 30 #include <sdbusplus/asio/detail/async_send_handler.hpp> 31 #include <sdbusplus/message.hpp> 32 #include <sdbusplus/utility/read_into_tuple.hpp> 33 #include <sdbusplus/utility/type_traits.hpp> 34 35 #include <chrono> 36 #include <string> 37 #include <tuple> 38 39 namespace sdbusplus 40 { 41 42 namespace asio 43 { 44 45 /// Root D-Bus IO object 46 /** 47 * A connection to a bus, through which messages may be sent or received. 48 */ 49 class connection : public sdbusplus::bus::bus 50 { 51 public: 52 // default to system bus 53 connection(boost::asio::io_context& io) : 54 sdbusplus::bus::bus(sdbusplus::bus::new_default()), io_(io), socket(io_) 55 { 56 socket.assign(get_fd()); 57 read_wait(); 58 } 59 connection(boost::asio::io_context& io, sd_bus* bus) : 60 sdbusplus::bus::bus(bus), io_(io), socket(io_) 61 { 62 socket.assign(get_fd()); 63 read_wait(); 64 } 65 ~connection() 66 { 67 // The FD will be closed by the socket object, so assign null to the 68 // sd_bus object to avoid a double close() Ignore return codes here, 69 // because there's nothing we can do about errors 70 socket.release(); 71 } 72 73 /** @brief Perform an asynchronous send of a message, executing the handler 74 * upon return and return 75 * 76 * @param[in] m - A message ready to send 77 * @param[in] handler - handler to execute upon completion; this may be an 78 * asio::yield_context to execute asynchronously as a 79 * coroutine 80 * 81 * @return If a yield context is passed as the handler, the return type is 82 * a message. If a function object is passed in as the handler, 83 * the return type is the result of the handler registration, 84 * while the resulting message will get passed into the handler. 85 */ 86 template <typename MessageHandler> 87 inline BOOST_ASIO_INITFN_RESULT_TYPE(MessageHandler, 88 void(boost::system::error_code, 89 message::message&)) 90 async_send(message::message& m, MessageHandler&& handler, 91 uint64_t timeout = 0) 92 { 93 boost::asio::async_completion< 94 MessageHandler, void(boost::system::error_code, message::message)> 95 init(handler); 96 detail::async_send_handler<typename boost::asio::async_result< 97 MessageHandler, void(boost::system::error_code, 98 message::message)>::completion_handler_type>( 99 std::move(init.completion_handler))(get(), m, timeout); 100 return init.result.get(); 101 } 102 103 /** @brief Perform an asynchronous method call, with input parameter packing 104 * and return value unpacking. 105 * 106 * @param[in] handler - A function object that is to be called as a 107 * continuation for the async dbus method call. The 108 * arguments to parse on the return are deduced from 109 * the handler's signature and then passed in along 110 * with an error code and optional message::message 111 * @param[in] service - The service to call. 112 * @param[in] objpath - The object's path for the call. 113 * @param[in] interf - The object's interface to call. 114 * @param[in] method - The object's method to call. 115 * @param[in] timeout - The timeout for the method call in usec (0 results 116 * in using the default value). 117 * @param[in] a... - Optional parameters for the method call. 118 * 119 * @return immediate return of the internal handler registration. The 120 * result of the actual asynchronous call will get unpacked from 121 * the message and passed into the handler when the call is 122 * complete. 123 */ 124 template <typename MessageHandler, typename... InputArgs> 125 void async_method_call_timed(MessageHandler&& handler, 126 const std::string& service, 127 const std::string& objpath, 128 const std::string& interf, 129 const std::string& method, uint64_t timeout, 130 const InputArgs&... a) 131 { 132 using FunctionTuple = boost::callable_traits::args_t<MessageHandler>; 133 using FunctionTupleType = utility::decay_tuple_t<FunctionTuple>; 134 constexpr bool returnWithMsg = []() { 135 if constexpr ((std::tuple_size_v<FunctionTupleType>) > 1) 136 { 137 return std::is_same_v< 138 std::tuple_element_t<1, FunctionTupleType>, 139 sdbusplus::message::message>; 140 } 141 return false; 142 }(); 143 using UnpackType = utility::strip_first_n_args_t<returnWithMsg ? 2 : 1, 144 FunctionTupleType>; 145 auto applyHandler = [handler = std::forward<MessageHandler>(handler)]( 146 boost::system::error_code ec, 147 message::message& r) mutable { 148 UnpackType responseData; 149 if (!ec) 150 { 151 try 152 { 153 utility::read_into_tuple(responseData, r); 154 } 155 catch (const std::exception& e) 156 { 157 // Set error code if not already set 158 ec = boost::system::errc::make_error_code( 159 boost::system::errc::invalid_argument); 160 } 161 } 162 // Note. Callback is called whether or not the unpack was 163 // successful to allow the user to implement their own handling 164 if constexpr (returnWithMsg) 165 { 166 auto response = std::tuple_cat(std::make_tuple(ec), 167 std::forward_as_tuple(r), 168 std::move(responseData)); 169 std::apply(handler, response); 170 } 171 else 172 { 173 auto response = std::tuple_cat(std::make_tuple(ec), 174 std::move(responseData)); 175 std::apply(handler, response); 176 } 177 }; 178 message::message m; 179 boost::system::error_code ec; 180 try 181 { 182 m = new_method_call(service.c_str(), objpath.c_str(), 183 interf.c_str(), method.c_str()); 184 m.append(a...); 185 } 186 catch (const exception::SdBusError& e) 187 { 188 ec = boost::system::errc::make_error_code( 189 static_cast<boost::system::errc::errc_t>(e.get_errno())); 190 applyHandler(ec, m); 191 return; 192 } 193 async_send(m, std::forward<decltype(applyHandler)>(applyHandler), 194 timeout); 195 } 196 197 /** @brief Perform an asynchronous method call, with input parameter packing 198 * and return value unpacking. Uses the default timeout value. 199 * 200 * @param[in] handler - A function object that is to be called as a 201 * continuation for the async dbus method call. The 202 * arguments to parse on the return are deduced from 203 * the handler's signature and then passed in along 204 * with an error code and optional message::message 205 * @param[in] service - The service to call. 206 * @param[in] objpath - The object's path for the call. 207 * @param[in] interf - The object's interface to call. 208 * @param[in] method - The object's method to call. 209 * @param[in] a... - Optional parameters for the method call. 210 * 211 * @return immediate return of the internal handler registration. The 212 * result of the actual asynchronous call will get unpacked from 213 * the message and passed into the handler when the call is 214 * complete. 215 */ 216 template <typename MessageHandler, typename... InputArgs> 217 void async_method_call(MessageHandler&& handler, const std::string& service, 218 const std::string& objpath, 219 const std::string& interf, const std::string& method, 220 const InputArgs&... a) 221 { 222 async_method_call_timed(std::forward<MessageHandler>(handler), service, 223 objpath, interf, method, 0, a...); 224 } 225 226 /** @brief Perform a yielding asynchronous method call, with input 227 * parameter packing and return value unpacking 228 * 229 * @param[in] yield - A yield context to async block upon. 230 * @param[in] ec - an error code that will be set for any errors 231 * @param[in] service - The service to call. 232 * @param[in] objpath - The object's path for the call. 233 * @param[in] interf - The object's interface to call. 234 * @param[in] method - The object's method to call. 235 * @param[in] a... - Optional parameters for the method call. 236 * 237 * @return Unpacked value of RetType 238 */ 239 template <typename... RetTypes, typename... InputArgs> 240 auto yield_method_call(boost::asio::yield_context yield, 241 boost::system::error_code& ec, 242 const std::string& service, 243 const std::string& objpath, 244 const std::string& interf, const std::string& method, 245 const InputArgs&... a) 246 { 247 message::message m; 248 try 249 { 250 m = new_method_call(service.c_str(), objpath.c_str(), 251 interf.c_str(), method.c_str()); 252 m.append(a...); 253 } 254 catch (const exception::SdBusError& e) 255 { 256 ec = boost::system::errc::make_error_code( 257 static_cast<boost::system::errc::errc_t>(e.get_errno())); 258 } 259 message::message r; 260 if (!ec) 261 { 262 r = async_send(m, yield[ec]); 263 } 264 if constexpr (sizeof...(RetTypes) == 0) 265 { 266 // void return 267 return; 268 } 269 else if constexpr (sizeof...(RetTypes) == 1) 270 { 271 if constexpr (std::is_same_v<utility::first_type_t<RetTypes...>, 272 void>) 273 { 274 return; 275 } 276 else 277 { 278 // single item return 279 utility::first_type_t<RetTypes...> responseData{}; 280 // before attempting to read, check ec and bail on error 281 if (ec) 282 { 283 return responseData; 284 } 285 try 286 { 287 r.read(responseData); 288 } 289 catch (const std::exception& e) 290 { 291 ec = boost::system::errc::make_error_code( 292 boost::system::errc::invalid_argument); 293 // responseData will be default-constructed... 294 } 295 return responseData; 296 } 297 } 298 else 299 { 300 // tuple of things to return 301 std::tuple<RetTypes...> responseData{}; 302 // before attempting to read, check ec and bail on error 303 if (ec) 304 { 305 return responseData; 306 } 307 try 308 { 309 r.read(responseData); 310 } 311 catch (const std::exception& e) 312 { 313 ec = boost::system::errc::make_error_code( 314 boost::system::errc::invalid_argument); 315 // responseData will be default-constructed... 316 } 317 return responseData; 318 } 319 } 320 321 boost::asio::io_context& get_io_context() 322 { 323 return io_; 324 } 325 326 private: 327 boost::asio::io_context& io_; 328 boost::asio::posix::stream_descriptor socket; 329 330 void read_wait() 331 { 332 socket.async_read_some( 333 boost::asio::null_buffers(), 334 [&](const boost::system::error_code& ec, std::size_t) { 335 if (ec) 336 { 337 return; 338 } 339 if (process_discard()) 340 { 341 read_immediate(); 342 } 343 else 344 { 345 read_wait(); 346 } 347 }); 348 } 349 void read_immediate() 350 { 351 boost::asio::post(io_, [&] { 352 if (process_discard()) 353 { 354 read_immediate(); 355 } 356 else 357 { 358 read_wait(); 359 } 360 }); 361 } 362 }; 363 364 } // namespace asio 365 366 } // namespace sdbusplus 367