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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "BootParameters.h"
#define LOG_TAG "BootParameters"
#include <errno.h>
#include <fcntl.h>
#include <android-base/file.h>
#include <json/json.h>
#include <utils/Log.h>
using android::base::ReadFileToString;
using android::base::RemoveFileIfExists;
using android::base::WriteStringToFile;
using Json::ArrayIndex;
using Json::Reader;
using Json::Value;
namespace android {
namespace {
// Keys for deprecated parameters. Devices that OTA from N to O and that used
// the hidden BootParameters API will store these in the JSON blob. To support
// the transition from N to O, these keys are mapped to the new parameters.
constexpr const char *kKeyLegacyVolume = "volume";
constexpr const char *kKeyLegacyAnimationsDisabled = "boot_animation_disabled";
constexpr const char *kKeyLegacyParamNames = "param_names";
constexpr const char *kKeyLegacyParamValues = "param_values";
constexpr const char *kNextBootFile = "/data/misc/bootanimation/next_boot.proto";
constexpr const char *kLastBootFile = "/data/misc/bootanimation/last_boot.proto";
constexpr const char *kLegacyNextBootFile = "/data/misc/bootanimation/next_boot.json";
constexpr const char *kLegacyLastBootFile = "/data/misc/bootanimation/last_boot.json";
void removeLegacyFiles() {
std::string err;
if (!RemoveFileIfExists(kLegacyLastBootFile, &err)) {
ALOGW("Unable to delete %s: %s", kLegacyLastBootFile, err.c_str());
}
err.clear();
if (!RemoveFileIfExists(kLegacyNextBootFile, &err)) {
ALOGW("Unable to delete %s: %s", kLegacyNextBootFile, err.c_str());
}
}
void createNextBootFile() {
errno = 0;
int fd = open(kNextBootFile, O_CREAT, DEFFILEMODE);
if (fd == -1) {
ALOGE("Unable to create next boot file: %s", strerror(errno));
} else {
// Make next_boot.json writable to everyone so DeviceManagementService
// can save saved_parameters there.
if (fchmod(fd, DEFFILEMODE))
ALOGE("Unable to set next boot file permissions: %s", strerror(errno));
close(fd);
}
}
} // namespace
// Renames the 'next' boot file to the 'last' file and reads its contents.
bool BootParameters::swapAndLoadBootConfigContents(const char *lastBootFile,
const char *nextBootFile,
std::string *contents) {
if (!ReadFileToString(nextBootFile, contents)) {
RemoveFileIfExists(lastBootFile);
return false;
}
errno = 0;
if (rename(nextBootFile, lastBootFile) && errno != ENOENT)
ALOGE("Unable to swap boot files: %s", strerror(errno));
return true;
}
BootParameters::BootParameters() {
loadParameters();
}
// Saves the boot parameters state to disk so the framework can read it.
void BootParameters::storeParameters() {
errno = 0;
if (!WriteStringToFile(mProto.SerializeAsString(), kLastBootFile)) {
ALOGE("Failed to write boot parameters to %s: %s", kLastBootFile, strerror(errno));
}
// WriteStringToFile sets the file permissions to 0666, but these are not
// honored by the system.
errno = 0;
if (chmod(kLastBootFile, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)) {
ALOGE("Failed to set permissions for %s: %s", kLastBootFile, strerror(errno));
}
}
// Load the boot parameters from disk, try the old location and format if the
// file does not exist. Note:
// - Parse errors result in defaults being used (a normal boot).
// - Legacy boot parameters default to a silent boot.
void BootParameters::loadParameters() {
// Precedence is given to the new file format (.proto).
std::string contents;
if (swapAndLoadBootConfigContents(kLastBootFile, kNextBootFile, &contents)) {
parseBootParameters(contents);
} else if (swapAndLoadBootConfigContents(kLegacyLastBootFile, kLegacyNextBootFile, &contents)) {
parseLegacyBootParameters(contents);
storeParameters();
removeLegacyFiles();
}
createNextBootFile();
}
void BootParameters::parseBootParameters(const std::string &contents) {
if (!mProto.ParseFromString(contents)) {
ALOGW("Failed to parse parameters from %s", kLastBootFile);
return;
}
loadStateFromProto();
}
// Parses the JSON in the proto.
void BootParameters::parseLegacyBootParameters(const std::string &contents) {
Value json;
if (!Reader().parse(contents, json)) {
ALOGW("Failed to parse parameters from %s", kLegacyLastBootFile);
return;
}
int volume = 0;
bool bootAnimationDisabled = true;
Value &jsonValue = json[kKeyLegacyVolume];
if (jsonValue.isIntegral()) {
volume = jsonValue.asInt();
}
jsonValue = json[kKeyLegacyAnimationsDisabled];
if (jsonValue.isIntegral()) {
bootAnimationDisabled = jsonValue.asInt() == 1;
}
// Assume a silent boot unless all of the following are true -
// 1. The volume is neither 0 nor -1000 (the legacy default value).
// 2. The boot animations are explicitly enabled.
// Note: brightness was never used.
mProto.set_silent_boot((volume == 0) || (volume == -1000) || bootAnimationDisabled);
Value &keys = json[kKeyLegacyParamNames];
Value &values = json[kKeyLegacyParamValues];
if (keys.isArray() && values.isArray() && (keys.size() == values.size())) {
for (ArrayIndex i = 0; i < keys.size(); ++i) {
auto &key = keys[i];
auto &value = values[i];
if (key.isString() && value.isString()) {
auto userParameter = mProto.add_user_parameter();
userParameter->set_key(key.asString());
userParameter->set_value(value.asString());
}
}
}
loadStateFromProto();
}
void BootParameters::loadStateFromProto() {
// A missing key returns a safe, default value.
// Ignore invalid or missing parameters.
mIsSilentBoot = mProto.silent_boot();
for (const auto ¶m : mProto.user_parameter()) {
mParameters.push_back({.key = param.key().c_str(), .value = param.value().c_str()});
}
}
} // namespace android
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