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   // A unique string that identifies this build. Normally a combination of the
41   // the version, signing keys and build target.
42   std::string build_fingerprint;
43 
44   // The board name this image was built for.
45   std::string board;
46 
47   // The release channel this image was obtained from.
48   std::string current_channel;
49 
50   // The Omaha URL this image should get updates from.
51   std::string omaha_url;
52 };
53 
54 // The mutable image properties are read-write image properties, initialized
55 // with values from the image but can be modified by storing them in the
56 // stateful partition.
57 struct MutableImageProperties {
58   // The release channel we are tracking.
59   std::string target_channel;
60 
61   // Whether powerwash is allowed when downloading an update for the selected
62   // target_channel.
63   bool is_powerwash_allowed{false};
64 };
65 
66 // Loads all the image properties from the running system. In case of error
67 // loading any of these properties from the read-only system image a default
68 // value may be returned instead.
69 ImageProperties LoadImageProperties(SystemState* system_state);
70 
71 // Loads the mutable image properties from the stateful partition if found or the
72 // system image otherwise.
73 MutableImageProperties LoadMutableImageProperties(SystemState* system_state);
74 
75 // Stores the mutable image properties in the stateful partition. Returns
76 // whether the operation succeeded.
77 bool StoreMutableImageProperties(SystemState* system_state,
78                                  const MutableImageProperties& properties);
79 
80 // Sets the root_prefix used to load files from during unittests to
81 // |test_root_prefix|. Passing a nullptr value resets it to the default.
82 namespace test {
83 void SetImagePropertiesRootPrefix(const char* test_root_prefix);
84 }  // namespace test
85 
86 }  // namespace chromeos_update_engine
87 
88 #endif  // UPDATE_ENGINE_IMAGE_PROPERTIES_H_
89