1/*
2 * Copyright (C) 2017 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 "BootParameters.h"
18
19#define LOG_TAG "BootParameters"
20
21#include <fcntl.h>
22
23#include <string>
24
25#include <android-base/file.h>
26#include <base/json/json_parser.h>
27#include <base/json/json_reader.h>
28#include <base/json/json_value_converter.h>
29#include <utils/Log.h>
30
31using android::base::RemoveFileIfExists;
32using android::base::ReadFileToString;
33using base::JSONReader;
34using base::JSONValueConverter;
35using base::Value;
36
37namespace android {
38
39namespace {
40
41// Brightness and volume are stored as integer strings in next_boot.json.
42// They are divided by this constant to produce the actual float values in
43// range [0.0, 1.0]. This constant must match its counterpart in
44// DeviceManager.
45constexpr const float kFloatScaleFactor = 1000.0f;
46
47constexpr const char* kNextBootFile = "/data/misc/bootanimation/next_boot.json";
48constexpr const char* kLastBootFile = "/data/misc/bootanimation/last_boot.json";
49
50void swapBootConfigs() {
51    // rename() will fail if next_boot.json doesn't exist, so delete
52    // last_boot.json manually first.
53    std::string err;
54    if (!RemoveFileIfExists(kLastBootFile, &err))
55        ALOGE("Unable to delete last boot file: %s", err.c_str());
56
57    if (rename(kNextBootFile, kLastBootFile) && errno != ENOENT)
58        ALOGE("Unable to swap boot files: %s", strerror(errno));
59
60    int fd = open(kNextBootFile, O_CREAT, DEFFILEMODE);
61    if (fd == -1) {
62        ALOGE("Unable to create next boot file: %s", strerror(errno));
63    } else {
64        // Make next_boot.json writable to everyone so DeviceManagementService
65        // can save saved_parameters there.
66        if (fchmod(fd, DEFFILEMODE))
67            ALOGE("Unable to set next boot file permissions: %s", strerror(errno));
68        close(fd);
69    }
70}
71
72}  // namespace
73
74BootParameters::SavedBootParameters::SavedBootParameters()
75    : brightness(-kFloatScaleFactor), volume(-kFloatScaleFactor) {}
76
77void BootParameters::SavedBootParameters::RegisterJSONConverter(
78        JSONValueConverter<SavedBootParameters>* converter) {
79    converter->RegisterIntField("brightness", &SavedBootParameters::brightness);
80    converter->RegisterIntField("volume", &SavedBootParameters::volume);
81    converter->RegisterRepeatedString("param_names",
82                                      &SavedBootParameters::param_names);
83    converter->RegisterRepeatedString("param_values",
84                                      &SavedBootParameters::param_values);
85}
86
87BootParameters::BootParameters() {
88    swapBootConfigs();
89    loadParameters();
90}
91
92void BootParameters::loadParameters() {
93    std::string contents;
94    if (!ReadFileToString(kLastBootFile, &contents)) {
95        if (errno != ENOENT)
96            ALOGE("Unable to read from %s: %s", kLastBootFile, strerror(errno));
97
98        return;
99    }
100
101    std::unique_ptr<Value> json = JSONReader::Read(contents);
102    if (json.get() == nullptr) {
103        return;
104    }
105
106    JSONValueConverter<SavedBootParameters> converter;
107    if (converter.Convert(*(json.get()), &mRawParameters)) {
108        mBrightness = mRawParameters.brightness / kFloatScaleFactor;
109        mVolume = mRawParameters.volume / kFloatScaleFactor;
110
111        if (mRawParameters.param_names.size() == mRawParameters.param_values.size()) {
112            for (size_t i = 0; i < mRawParameters.param_names.size(); i++) {
113                mParameters.push_back({
114                        .key = mRawParameters.param_names[i]->c_str(),
115                        .value = mRawParameters.param_values[i]->c_str()
116                });
117            }
118        } else {
119            ALOGW("Parameter names and values size mismatch");
120        }
121    }
122}
123
124}  // namespace android
125