1 /* 2 * Copyright 2020 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 <array> 19 #include <chrono> 20 #include <cstdint> 21 #include <list> 22 #include <memory> 23 #include <mutex> 24 #include <string> 25 26 #include "hci/address.h" 27 #include "module.h" 28 #include "storage/adapter_config.h" 29 #include "storage/config_cache.h" 30 #include "storage/device.h" 31 #include "storage/mutation.h" 32 33 namespace bluetooth { 34 35 namespace shim { 36 class BtifConfigInterface; 37 } 38 39 namespace storage { 40 41 class StorageModule : public bluetooth::Module { 42 public: 43 static const std::string kInfoSection; 44 static const std::string kFileSourceProperty; 45 static const std::string kTimeCreatedProperty; 46 static const std::string kTimeCreatedFormat; 47 48 static const std::string kAdapterSection; 49 50 // Create the storage module where: 51 // - config_file_path is the path to the config file on disk, a .bak file will be created with the original 52 // - config_save_delay is the duration after which to dump config to disk after SaveDelayed() is called 53 // - temp_devices_capacity is the number of temporary, typically unpaired devices to hold in a memory based LRU 54 // - is_restricted_mode and is_single_user_mode are flags from upper layer 55 StorageModule( 56 std::string config_file_path, 57 std::chrono::milliseconds config_save_delay, 58 size_t temp_devices_capacity, 59 bool is_restricted_mode, 60 bool is_single_user_mode); 61 ~StorageModule() override; 62 static const ModuleFactory Factory; 63 64 // Methods to access the storage layer via Device abstraction 65 // - Devices will be lazily created when methods below are called. Hence, no std::optional<> nor nullptr is used in 66 // the return type. User of the API can use the Device object's API to find out if the device has existed before 67 // - Devices with no config values will not be saved to config cache 68 // - Devices that are not paired will also be discarded when stack shutdown 69 70 // Concept: 71 // 72 // BR/EDR Address: 73 // -> Public static address only, begin with 3 byte IEEE assigned OUI number 74 // 75 // BLE Addresses 76 // -> Public Address: begin with IEEE assigned OUI number 77 // -> Static: static public address do not change 78 // -> Private/Variable: We haven't seen private/variable public address yet 79 // -> Random Address: randomly generated, does not begin with IEEE assigned OUI number 80 // -> Static: static random address do not change 81 // -> Private/Variable: private random address changes once so often 82 // -> Resolvable: this address can be resolved into a static address using identity resolving key (IRK) 83 // -> Non-resolvable: this address is for temporary use only, do not save this address 84 // 85 // MAC addresses are six bytes only and hence are only regionally unique 86 87 // Get a device object using the |legacy_key_address|. In legacy config, each device's config is stored in a config 88 // section keyed by a single MAC address. For BR/EDR device, this is straightforward as a BR/EDR device has only a 89 // single public static MAC address. However, for LE devices using private addresses, we only learn its real static 90 // address after pairing. Since we still need to store that device's information prior to pairing, we use the 91 // first-seen address of that device, no matter random private or static public, as a "key" to store that device's 92 // config. This method gives you a device object using this legacy key. If the key does not exist, the device will 93 // be lazily created in the config 94 Device GetDeviceByLegacyKey(hci::Address legacy_key_address); 95 96 // A classic (BR/EDR) or dual mode device can be uniquely located by its classic (BR/EDR) MAC address 97 Device GetDeviceByClassicMacAddress(hci::Address classic_address); 98 99 // A LE or dual mode device can be uniquely located by its identity address that is either: 100 // -> Public static address 101 // -> Random static address 102 // If remote device uses LE random private resolvable address, user of this API must resolve its identity address 103 // before calling this method to get the device object 104 // 105 // Note: A dual mode device's identity address is normally the same as its BR/EDR address, but they can also be 106 // different. Hence, please don't make such assumption and don't use GetDeviceByBrEdrMacAddress() interchangeably 107 Device GetDeviceByLeIdentityAddress(hci::Address le_identity_address); 108 109 // A think copyable, movable, comparable object that is used to access adapter level information 110 AdapterConfig GetAdapterConfig(); 111 112 // Get a list of bonded devices from config 113 std::vector<Device> GetBondedDevices(); 114 115 // Modify the underlying config by starting a mutation. All entries in the mutation will be applied atomically when 116 // Commit() is called. User should never touch ConfigCache() directly. 117 Mutation Modify(); 118 119 protected: 120 void ListDependencies(ModuleList* list) override; 121 void Start() override; 122 void Stop() override; 123 std::string ToString() const override; 124 125 friend shim::BtifConfigInterface; 126 // For shim layer only 127 ConfigCache* GetConfigCache(); 128 // For unit test only 129 ConfigCache* GetMemoryOnlyConfigCache(); 130 // Normally, underlying config will be saved at most 3 seconds after the first config change in a series of changes 131 // This method triggers the delayed saving automatically, the delay is equal to |config_save_delay_| 132 void SaveDelayed(); 133 // In some cases, one may want to save the config immediately to disk. Call this method with caution as it runs 134 // immediately on the calling thread 135 void SaveImmediately(); 136 137 private: 138 struct impl; 139 mutable std::recursive_mutex mutex_; 140 std::unique_ptr<impl> pimpl_; 141 std::string config_file_path_; 142 std::string config_backup_path_; 143 std::chrono::milliseconds config_save_delay_; 144 size_t temp_devices_capacity_; 145 bool is_restricted_mode_; 146 bool is_single_user_mode_; 147 148 DISALLOW_COPY_AND_ASSIGN(StorageModule); 149 }; 150 151 } // namespace storage 152 } // namespace bluetooth 153