aosp12/system/gsid/libgsi.cpp

134 lines
3.8 KiB
C++

//
// Copyright (C) 2019 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 "libgsi/libgsi.h"
#include <string.h>
#include <unistd.h>
#include <string>
#include <android-base/file.h>
#include <android-base/parseint.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include "file_paths.h"
#include "libgsi_private.h"
namespace android {
namespace gsi {
using namespace std::literals;
using android::base::ReadFileToString;
using android::base::Split;
using android::base::unique_fd;
bool IsGsiRunning() {
return !access(kGsiBootedIndicatorFile, F_OK);
}
bool IsGsiInstalled() {
return !access(kDsuInstallStatusFile, F_OK);
}
static bool WriteAndSyncFile(const std::string& data, const std::string& file) {
unique_fd fd(open(file.c_str(), O_WRONLY | O_NOFOLLOW | O_CLOEXEC));
if (fd < 0) {
return false;
}
if (!android::base::WriteFully(fd, data.c_str(), data.size())) {
return false;
}
return fsync(fd) == 0;
}
std::string GetDsuSlot(const std::string& install_dir) {
return android::base::Basename(install_dir);
}
bool CanBootIntoGsi(std::string* error) {
// Always delete this as a safety precaution, so we can return to the
// original system image. If we're confident GSI will boot, this will
// get re-created by MarkSystemAsGsi.
android::base::RemoveFileIfExists(kGsiBootedIndicatorFile);
if (!IsGsiInstalled()) {
*error = "not detected";
return false;
}
std::string boot_key;
if (!GetInstallStatus(&boot_key)) {
*error = "error ("s + strerror(errno) + ")";
return false;
}
// Give up if we've failed to boot kMaxBootAttempts times.
int attempts;
if (GetBootAttempts(boot_key, &attempts)) {
if (attempts + 1 > kMaxBootAttempts) {
*error = "exceeded max boot attempts";
return false;
}
std::string new_key;
if (!access(kDsuOneShotBootFile, F_OK)) {
// Mark the GSI as disabled. This only affects the next boot, not
// the current boot. Note that we leave the one_shot status behind.
// This is so IGsiService can still return GSI_STATE_SINGLE_BOOT
// while the GSI is running.
new_key = kInstallStatusDisabled;
} else {
new_key = std::to_string(attempts + 1);
}
if (!WriteAndSyncFile(new_key, kDsuInstallStatusFile)) {
*error = "error ("s + strerror(errno) + ")";
return false;
}
return true;
}
if (boot_key != kInstallStatusOk) {
*error = "not enabled";
return false;
}
return true;
}
bool UninstallGsi() {
return android::base::WriteStringToFile(kInstallStatusWipe, kDsuInstallStatusFile);
}
bool DisableGsi() {
return android::base::WriteStringToFile(kInstallStatusDisabled, kDsuInstallStatusFile);
}
bool MarkSystemAsGsi() {
return android::base::WriteStringToFile("1", kGsiBootedIndicatorFile);
}
bool GetInstallStatus(std::string* status) {
return android::base::ReadFileToString(kDsuInstallStatusFile, status);
}
bool GetBootAttempts(const std::string& boot_key, int* attempts) {
return android::base::ParseInt(boot_key, attempts);
}
} // namespace gsi
} // namespace android