image_properties_chromeos.cc revision 3be05c82442b2fbab693b6399f64610e8542462b 
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#include "update_engine/image_properties.h"
18
19#include <string>
20#include <vector>
21
22#include <base/files/file_util.h>
23#include <base/logging.h>
24#include <brillo/key_value_store.h>
25
26#include "update_engine/constants.h"
27#include "update_engine/hardware_interface.h"
28#include "update_engine/platform_constants.h"
29#include "update_engine/system_state.h"
30
31namespace {
32
33const char kLsbRelease[] = "/etc/lsb-release";
34
35const char kLsbReleaseAppIdKey[] = "CHROMEOS_RELEASE_APPID";
36const char kLsbReleaseAutoUpdateServerKey[] = "CHROMEOS_AUSERVER";
37const char kLsbReleaseBoardAppIdKey[] = "CHROMEOS_BOARD_APPID";
38const char kLsbReleaseBoardKey[] = "CHROMEOS_RELEASE_BOARD";
39const char kLsbReleaseCanaryAppIdKey[] = "CHROMEOS_CANARY_APPID";
40const char kLsbReleaseIsPowerwashAllowedKey[] = "CHROMEOS_IS_POWERWASH_ALLOWED";
41const char kLsbReleaseUpdateChannelKey[] = "CHROMEOS_RELEASE_TRACK";
42const char kLsbReleaseVersionKey[] = "CHROMEOS_RELEASE_VERSION";
43
44const char kDefaultAppId[] = "{87efface-864d-49a5-9bb3-4b050a7c227a}";
45
46// A prefix added to the path, used for testing.
47const char* root_prefix = nullptr;
48
49std::string GetStringWithDefault(const brillo::KeyValueStore& store,
50                                 const std::string& key,
51                                 const std::string& default_value) {
52  std::string result;
53  if (store.GetString(key, &result))
54    return result;
55  LOG(INFO) << "Cannot load ImageProperty " << key << ", using default value "
56            << default_value;
57  return default_value;
58}
59
60enum class LsbReleaseSource {
61  kSystem,
62  kStateful,
63};
64
65// Loads the lsb-release properties into the key-value |store| reading the file
66// from either the system image or the stateful partition as specified by
67// |source|. The loaded values are added to the store, possibly overriding
68// existing values.
69void LoadLsbRelease(LsbReleaseSource source, brillo::KeyValueStore* store) {
70  std::string path;
71  if (root_prefix)
72    path = root_prefix;
73  if (source == LsbReleaseSource::kStateful)
74    path += chromeos_update_engine::kStatefulPartition;
75  store->Load(base::FilePath(path + kLsbRelease));
76}
77
78}  // namespace
79
80namespace chromeos_update_engine {
81
82namespace test {
83void SetImagePropertiesRootPrefix(const char* test_root_prefix) {
84  root_prefix = test_root_prefix;
85}
86}  // namespace test
87
88ImageProperties LoadImageProperties(SystemState* system_state) {
89  ImageProperties result;
90
91  brillo::KeyValueStore lsb_release;
92  LoadLsbRelease(LsbReleaseSource::kSystem, &lsb_release);
93  result.current_channel = GetStringWithDefault(
94      lsb_release, kLsbReleaseUpdateChannelKey, "stable-channel");
95
96  // In dev-mode and unofficial build we can override the image properties set
97  // in the system image with the ones from the stateful partition, except the
98  // channel of the current image.
99  HardwareInterface* const hardware = system_state->hardware();
100  if (!hardware->IsOfficialBuild() || !hardware->IsNormalBootMode())
101    LoadLsbRelease(LsbReleaseSource::kStateful, &lsb_release);
102
103  // The release_app_id is used as the default appid, but can be override by
104  // the board appid in the general case or the canary appid for the canary
105  // channel only.
106  std::string release_app_id =
107      GetStringWithDefault(lsb_release, kLsbReleaseAppIdKey, kDefaultAppId);
108
109  result.product_id = GetStringWithDefault(
110      lsb_release, kLsbReleaseBoardAppIdKey, release_app_id);
111  result.canary_product_id = GetStringWithDefault(
112      lsb_release, kLsbReleaseCanaryAppIdKey, release_app_id);
113  result.board = GetStringWithDefault(lsb_release, kLsbReleaseBoardKey, "");
114  result.version = GetStringWithDefault(lsb_release, kLsbReleaseVersionKey, "");
115  result.omaha_url =
116      GetStringWithDefault(lsb_release, kLsbReleaseAutoUpdateServerKey,
117                           constants::kOmahaDefaultProductionURL);
118
119  return result;
120}
121
122MutableImageProperties LoadMutableImageProperties(SystemState* system_state) {
123  MutableImageProperties result;
124  brillo::KeyValueStore lsb_release;
125  LoadLsbRelease(LsbReleaseSource::kSystem, &lsb_release);
126  LoadLsbRelease(LsbReleaseSource::kStateful, &lsb_release);
127  result.target_channel = GetStringWithDefault(
128      lsb_release, kLsbReleaseUpdateChannelKey, "stable-channel");
129  if (!lsb_release.GetBoolean(kLsbReleaseIsPowerwashAllowedKey,
130                              &result.is_powerwash_allowed))
131    result.is_powerwash_allowed = false;
132  return result;
133}
134
135bool StoreMutableImageProperties(SystemState* system_state,
136                                 const MutableImageProperties& properties) {
137  brillo::KeyValueStore lsb_release;
138  LoadLsbRelease(LsbReleaseSource::kStateful, &lsb_release);
139  lsb_release.SetString(kLsbReleaseUpdateChannelKey, properties.target_channel);
140  lsb_release.SetBoolean(kLsbReleaseIsPowerwashAllowedKey,
141                         properties.is_powerwash_allowed);
142
143  base::FilePath path(std::string(root_prefix) + kStatefulPartition +
144                      kLsbRelease);
145  if (!base::DirectoryExists(path.DirName()))
146    base::CreateDirectory(path.DirName());
147  return lsb_release.Save(path);
148}
149
150}  // namespace chromeos_update_engine
151