image_properties.h revision 856166594771c61973856f563e622ccb7dd48aa1 
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
26namespace chromeos_update_engine {
27
28class SystemState;
29
30// The read-only system properties of the running image.
31struct 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.
53struct 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.
65ImageProperties LoadImageProperties(SystemState* system_state);
66
67// Loads the mutable image properties from the stateful partition if found or the
68// system image otherwise.
69MutableImageProperties LoadMutableImageProperties(SystemState* system_state);
70
71// Stores the mutable image properties in the stateful partition. Returns
72// whether the operation succeeded.
73bool 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|.
78namespace test {
79void SetImagePropertiesRootPrefix(const char* test_root_prefix);
80}  // namespace test
81
82}  // namespace chromeos_update_engine
83
84#endif  // UPDATE_ENGINE_IMAGE_PROPERTIES_H_
85