1 //
2 // Copyright (C) 2015 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 
17 // This module abstracts the properties tied to the current running image. These
18 // properties are meant to be constant during the life of this daemon, but can
19 // be modified in dev-move or non-official builds.
20 
21 #ifndef UPDATE_ENGINE_IMAGE_PROPERTIES_H_
22 #define UPDATE_ENGINE_IMAGE_PROPERTIES_H_
23 
24 #include <string>
25 
26 namespace chromeos_update_engine {
27 
28 class SystemState;
29 
30 // The read-only system properties of the running image.
31 struct ImageProperties {
32   // The product id of the image used for all channels, except canary.
33   std::string product_id;
34   // The canary-channel product id.
35   std::string canary_product_id;
36 
37   // The product version of this image.
38   std::string version;
39 
40   // The board name this image was built for.
41   std::string board;
42 
43   // The release channel this image was obtained from.
44   std::string current_channel;
45 
46   // The Omaha URL this image should get updates from.
47   std::string omaha_url;
48 };
49 
50 // The mutable image properties are read-write image properties, initialized
51 // with values from the image but can be modified by storing them in the
52 // stateful partition.
53 struct MutableImageProperties {
54   // The release channel we are tracking.
55   std::string target_channel;
56 
57   // Whether powerwash is allowed when downloading an update for the selected
58   // target_channel.
59   bool is_powerwash_allowed{false};
60 };
61 
62 // Loads all the image properties from the running system. In case of error
63 // loading any of these properties from the read-only system image a default
64 // value may be returned instead.
65 ImageProperties LoadImageProperties(SystemState* system_state);
66 
67 // Loads the mutable image properties from the stateful partition if found or the
68 // system image otherwise.
69 MutableImageProperties LoadMutableImageProperties(SystemState* system_state);
70 
71 // Stores the mutable image properties in the stateful partition. Returns
72 // whether the operation succeeded.
73 bool StoreMutableImageProperties(SystemState* system_state,
74                                  const MutableImageProperties& properties);
75 
76 // Sets the root_prefix used to load files from during unittests to
77 // |test_root_prefix|. Passing a nullptr value resets it to the default.
78 namespace test {
79 void SetImagePropertiesRootPrefix(const char* test_root_prefix);
80 }  // namespace test
81 
82 }  // namespace chromeos_update_engine
83 
84 #endif  // UPDATE_ENGINE_IMAGE_PROPERTIES_H_
85