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 #include <vector>
26 
27 #include "hci/address.h"
28 #include "module.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 security::internal {
40 class SecurityManagerImpl;
41 }
42 
43 namespace hci {
44 class AclManager;
45 }
46 
47 namespace storage {
48 
49 class StorageModule : public bluetooth::Module {
50 public:
51   static const std::string kInfoSection;
52   static const std::string kFileSourceProperty;
53   static const std::string kTimeCreatedProperty;
54   static const std::string kTimeCreatedFormat;
55 
56   static const std::string kAdapterSection;
57 
58   StorageModule(const StorageModule&) = delete;
59   StorageModule& operator=(const StorageModule&) = delete;
60 
61   ~StorageModule();
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
66   // nullptr is used in
67   //   the return type. User of the API can use the Device object's API to find out if the device
68   //   has existed before
69   // - Devices with no config values will not be saved to config cache
70   // - Devices that are not paired will also be discarded when stack shutdown
71 
72   // Concept:
73   //
74   // BR/EDR Address:
75   //  -> Public static address only, begin with 3 byte IEEE assigned OUI number
76   //
77   // BLE Addresses
78   //  -> Public Address: begin with IEEE assigned OUI number
79   //     -> Static: static public address do not change
80   //     -> Private/Variable: We haven't seen private/variable public address yet
81   //  -> Random Address: randomly generated, does not begin with IEEE assigned OUI number
82   //     -> Static: static random address do not change
83   //     -> Private/Variable: private random address changes once so often
84   //        -> Resolvable: this address can be resolved into a static address using identity
85   //        resolving key (IRK)
86   //        -> Non-resolvable: this address is for temporary use only, do not save this address
87   //
88   // MAC addresses are six bytes only and hence are only regionally unique
89 
90   // Get a device object using the |legacy_key_address|. In legacy config, each device's config is
91   // stored in a config section keyed by a single MAC address. For BR/EDR device, this is
92   // straightforward as a BR/EDR device has only a single public static MAC address. However, for LE
93   // devices using private addresses, we only learn its real static address after pairing. Since we
94   // still need to store that device's information prior to pairing, we use the first-seen address
95   // of that device, no matter random private or static public, as a "key" to store that device's
96   // config. This method gives you a device object using this legacy key. If the key does not exist,
97   // the device will be lazily created in the config
98   Device GetDeviceByLegacyKey(hci::Address legacy_key_address);
99 
100   // A classic (BR/EDR) or dual mode device can be uniquely located by its classic (BR/EDR) MAC
101   // address
102   Device GetDeviceByClassicMacAddress(hci::Address classic_address);
103 
104   // A LE or dual mode device can be uniquely located by its identity address that is either:
105   //   -> Public static address
106   //   -> Random static address
107   // If remote device uses LE random private resolvable address, user of this API must resolve its
108   // identity address before calling this method to get the device object
109   //
110   // Note: A dual mode device's identity address is normally the same as its BR/EDR address, but
111   // they can also be different. Hence, please don't make such assumption and don't use
112   // GetDeviceByBrEdrMacAddress() interchangeably
113   Device GetDeviceByLeIdentityAddress(hci::Address le_identity_address);
114 
115   // Get a list of bonded devices from config
116   std::vector<Device> GetBondedDevices();
117 
118   // Modify the underlying config by starting a mutation. All entries in the mutation will be
119   // applied atomically when Commit() is called. User should never touch ConfigCache() directly.
120   Mutation Modify();
121 
122 protected:
123   void ListDependencies(ModuleList* list) const override;
124   void Start() override;
125   void Stop() override;
126   std::string ToString() const override;
127 
128   friend shim::BtifConfigInterface;
129   friend hci::AclManager;
130   friend security::internal::SecurityManagerImpl;
131   // For unit test only
132   ConfigCache* GetMemoryOnlyConfigCache();
133   // Normally, underlying config will be saved at most 3 seconds after the first config change in a
134   // series of changes This method triggers the delayed saving automatically, the delay is equal to
135   // |config_save_delay_|
136   void SaveDelayed();
137   // In some cases, one may want to save the config immediately to disk. Call this method with
138   // caution as it runs immediately on the calling thread
139   void SaveImmediately();
140   // remove all content in this config cache, restore it to the state after the explicit constructor
141   void Clear();
142 
143   // Create the storage module where:
144   // - config_file_path is the path to the config file on disk
145   // - config_save_delay is the duration after which to dump config to disk after SaveDelayed() is
146   // called
147   // - temp_devices_capacity is the number of temporary, typically unpaired devices to hold in a
148   // memory based LRU
149   // - is_restricted_mode and is_single_user_mode are flags from upper layer
150   StorageModule(std::string config_file_path, std::chrono::milliseconds config_save_delay,
151                 size_t temp_devices_capacity, bool is_restricted_mode, bool is_single_user_mode);
152 
153   bool HasSection(const std::string& section) const;
154   bool HasProperty(const std::string& section, const std::string& property) const;
155 
156   std::optional<std::string> GetProperty(const std::string& section,
157                                          const std::string& property) const;
158   void SetProperty(std::string section, std::string property, std::string value);
159 
160   std::vector<std::string> GetPersistentSections() const;
161 
162   void RemoveSection(const std::string& section);
163   bool RemoveProperty(const std::string& section, const std::string& property);
164   void ConvertEncryptOrDecryptKeyIfNeeded();
165   // Remove sections with |property| set
166   void RemoveSectionWithProperty(const std::string& property);
167 
168   void SetBool(const std::string& section, const std::string& property, bool value);
169   std::optional<bool> GetBool(const std::string& section, const std::string& property) const;
170   void SetUint64(const std::string& section, const std::string& property, uint64_t value);
171   std::optional<uint64_t> GetUint64(const std::string& section, const std::string& property) const;
172   void SetUint32(const std::string& section, const std::string& property, uint32_t value);
173   std::optional<uint32_t> GetUint32(const std::string& section, const std::string& property) const;
174   void SetInt64(const std::string& section, const std::string& property, int64_t value);
175   std::optional<int64_t> GetInt64(const std::string& section, const std::string& property) const;
176   void SetInt(const std::string& section, const std::string& property, int value);
177   std::optional<int> GetInt(const std::string& section, const std::string& property) const;
178   void SetBin(const std::string& section, const std::string& property,
179               const std::vector<uint8_t>& value);
180   std::optional<std::vector<uint8_t>> GetBin(const std::string& section,
181                                              const std::string& property) const;
182 
183 private:
184   struct impl;
185   mutable std::recursive_mutex mutex_;
186   std::unique_ptr<impl> pimpl_;
187   std::string config_file_path_;
188   std::string config_backup_path_;
189   std::chrono::milliseconds config_save_delay_;
190   size_t temp_devices_capacity_;
191   bool is_restricted_mode_;
192   bool is_single_user_mode_;
193   static bool is_config_checksum_pass(int check_bit);
194 };
195 
196 }  // namespace storage
197 }  // namespace bluetooth
198