1 /* 2 * Copyright 2022, The Android Open Source Project 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 <aidl/android/hardware/automotive/can/Result.h> 19 20 #include <android-base/macros.h> 21 #include <utils/Mutex.h> 22 23 #include <atomic> 24 #include <mutex> 25 26 namespace aidl::android::hardware::automotive::can { 27 28 class CanBus { 29 public: 30 /** 31 * Some interface types (such as SLCAN) don't get an interface name until after being 32 * initialized, hence ifname is optional. 33 * 34 * You MUST ensure mIfname is initialized prior to the completion of preUp(). 35 */ 36 CanBus(std::string_view ifname = std::string_view{""}); 37 38 virtual ~CanBus(); 39 40 Result up(); 41 Result down(); 42 std::string getIfaceName(); 43 44 protected: 45 /** 46 * Prepare the SocketCAN interface. 47 * 48 * After calling this method, mIfname network interface is available and ready to be brought up. 49 * 50 * \return true upon success and false upon failure 51 */ 52 virtual Result preUp(); 53 54 /** 55 * Cleanup after bringing the interface down. 56 * 57 * This is a counterpart to preUp(). 58 * 59 * \return true upon success and false upon failure 60 */ 61 virtual bool postDown(); 62 63 /** Network interface name. */ 64 std::string mIfname; 65 66 private: 67 /** 68 * Guard for up flag is required to be held for entire time when the interface is being used 69 * because we don't want the interface to be torn down while executing that operation. 70 */ 71 std::mutex mIsUpGuard; 72 bool mIsUp GUARDED_BY(mIsUpGuard) = false; 73 74 bool mDownAfterUse; 75 }; 76 77 } // namespace aidl::android::hardware::automotive::can 78