/*
* 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 "updater/updater_runtime.h"
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <ext4_utils/wipe.h>
#include <fs_mgr.h>
#include <selinux/label.h>
#include <tune2fs.h>
#include "mounts.h"
#include "otautil/sysutil.h"
std::string UpdaterRuntime::GetProperty(const std::string_view key,
const std::string_view default_value) const {
return android::base::GetProperty(std::string(key), std::string(default_value));
}
std::string UpdaterRuntime::FindBlockDeviceName(const std::string_view name) const {
return std::string(name);
}
static bool setMountFlag(const std::string& flag, unsigned* mount_flags) {
static constexpr std::pair<const char*, unsigned> mount_flags_list[] = {
{ "noatime", MS_NOATIME },
{ "noexec", MS_NOEXEC },
{ "nosuid", MS_NOSUID },
{ "nodev", MS_NODEV },
{ "nodiratime", MS_NODIRATIME },
{ "ro", MS_RDONLY },
{ "rw", 0 },
{ "remount", MS_REMOUNT },
{ "bind", MS_BIND },
{ "rec", MS_REC },
{ "unbindable", MS_UNBINDABLE },
{ "private", MS_PRIVATE },
{ "slave", MS_SLAVE },
{ "shared", MS_SHARED },
{ "defaults", 0 },
};
for (const auto& [name, value] : mount_flags_list) {
if (flag == name) {
*mount_flags |= value;
return true;
}
}
return false;
}
static bool parseMountFlags(const std::string& flags, unsigned* mount_flags,
std::string* fs_options) {
bool is_flag_set = false;
std::vector<std::string> flag_list;
for (const auto& flag : android::base::Split(flags, ",")) {
if (!setMountFlag(flag, mount_flags)) {
// Unknown flag, so it must be a filesystem specific option.
flag_list.push_back(flag);
} else {
is_flag_set = true;
}
}
*fs_options = android::base::Join(flag_list, ',');
return is_flag_set;
}
int UpdaterRuntime::Mount(const std::string_view location, const std::string_view mount_point,
const std::string_view fs_type, const std::string_view mount_options) {
std::string mount_point_string(mount_point);
std::string mount_options_string(mount_options);
char* secontext = nullptr;
unsigned mount_flags = 0;
std::string fs_options;
if (sehandle_) {
selabel_lookup(sehandle_, &secontext, mount_point_string.c_str(), 0755);
setfscreatecon(secontext);
}
mkdir(mount_point_string.c_str(), 0755);
if (secontext) {
freecon(secontext);
setfscreatecon(nullptr);
}
if (!parseMountFlags(mount_options_string, &mount_flags, &fs_options)) {
// Fall back to default
mount_flags = MS_NOATIME | MS_NODEV | MS_NODIRATIME;
}
return mount(std::string(location).c_str(), mount_point_string.c_str(),
std::string(fs_type).c_str(), mount_flags, fs_options.c_str());
}
bool UpdaterRuntime::IsMounted(const std::string_view mount_point) const {
scan_mounted_volumes();
MountedVolume* vol = find_mounted_volume_by_mount_point(std::string(mount_point).c_str());
return vol != nullptr;
}
std::pair<bool, int> UpdaterRuntime::Unmount(const std::string_view mount_point) {
scan_mounted_volumes();
MountedVolume* vol = find_mounted_volume_by_mount_point(std::string(mount_point).c_str());
if (vol == nullptr) {
return { false, -1 };
}
int ret = unmount_mounted_volume(vol);
return { true, ret };
}
bool UpdaterRuntime::ReadFileToString(const std::string_view filename, std::string* content) const {
return android::base::ReadFileToString(std::string(filename), content);
}
bool UpdaterRuntime::WriteStringToFile(const std::string_view content,
const std::string_view filename) const {
return android::base::WriteStringToFile(std::string(content), std::string(filename));
}
int UpdaterRuntime::WipeBlockDevice(const std::string_view filename, size_t len) const {
android::base::unique_fd fd(open(std::string(filename).c_str(), O_WRONLY));
if (fd == -1) {
PLOG(ERROR) << "Failed to open " << filename;
return false;
}
// The wipe_block_device function in ext4_utils returns 0 on success and 1 for failure.
return wipe_block_device(fd, len);
}
int UpdaterRuntime::RunProgram(const std::vector<std::string>& args, bool is_vfork) const {
CHECK(!args.empty());
auto argv = StringVectorToNullTerminatedArray(args);
LOG(INFO) << "about to run program [" << args[0] << "] with " << argv.size() << " args";
pid_t child = is_vfork ? vfork() : fork();
if (child == 0) {
execv(argv[0], argv.data());
PLOG(ERROR) << "run_program: execv failed";
_exit(EXIT_FAILURE);
}
int status;
waitpid(child, &status, 0);
if (WIFEXITED(status)) {
if (WEXITSTATUS(status) != 0) {
LOG(ERROR) << "run_program: child exited with status " << WEXITSTATUS(status);
}
} else if (WIFSIGNALED(status)) {
LOG(ERROR) << "run_program: child terminated by signal " << WTERMSIG(status);
}
return status;
}
int UpdaterRuntime::Tune2Fs(const std::vector<std::string>& args) const {
auto tune2fs_args = StringVectorToNullTerminatedArray(args);
// tune2fs changes the filesystem parameters on an ext2 filesystem; it returns 0 on success.
return tune2fs_main(tune2fs_args.size() - 1, tune2fs_args.data());
}
std::string UpdaterRuntime::AddSlotSuffix(const std::string_view arg) const {
return std::string(arg) + fs_mgr_get_slot_suffix();
}
