/*
* 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 "install/fuse_sdcard_install.h"
#include <dirent.h>
#include <signal.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <algorithm>
#include <functional>
#include <memory>
#include <vector>
#include <android-base/logging.h>
#include <android-base/strings.h>
#include "bootloader_message/bootloader_message.h"
#include "fuse_provider.h"
#include "fuse_sideload.h"
#include "install/install.h"
#include "otautil/roots.h"
static constexpr const char* SDCARD_ROOT = "/sdcard";
// How long (in seconds) we wait for the fuse-provided package file to
// appear, before timing out.
static constexpr int SDCARD_INSTALL_TIMEOUT = 10;
// Set the BCB to reboot back into recovery (it won't resume the install from
// sdcard though).
static void SetSdcardUpdateBootloaderMessage() {
std::vector<std::string> options;
std::string err;
if (!update_bootloader_message(options, &err)) {
LOG(ERROR) << "Failed to set BCB message: " << err;
}
}
// Returns the selected filename, or an empty string.
static std::string BrowseDirectory(const std::string& path, Device* device, RecoveryUI* ui) {
ensure_path_mounted(path);
std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path.c_str()), closedir);
if (!d) {
PLOG(ERROR) << "error opening " << path;
return "";
}
std::vector<std::string> dirs;
std::vector<std::string> entries{ "../" }; // "../" is always the first entry.
dirent* de;
while ((de = readdir(d.get())) != nullptr) {
std::string name(de->d_name);
if (de->d_type == DT_DIR) {
// Skip "." and ".." entries.
if (name == "." || name == "..") continue;
dirs.push_back(name + "/");
} else if (de->d_type == DT_REG && android::base::EndsWithIgnoreCase(name, ".zip")) {
entries.push_back(name);
}
}
std::sort(dirs.begin(), dirs.end());
std::sort(entries.begin(), entries.end());
// Append dirs to the entries list.
entries.insert(entries.end(), dirs.begin(), dirs.end());
std::vector<std::string> headers{ "Choose a package to install:", path };
size_t chosen_item = 0;
while (true) {
chosen_item = ui->ShowMenu(
headers, entries, chosen_item, true,
std::bind(&Device::HandleMenuKey, device, std::placeholders::_1, std::placeholders::_2));
// Return if WaitKey() was interrupted.
if (chosen_item == static_cast<size_t>(RecoveryUI::KeyError::INTERRUPTED)) {
return "";
}
const std::string& item = entries[chosen_item];
if (chosen_item == 0) {
// Go up but continue browsing (if the caller is BrowseDirectory).
return "";
}
std::string new_path = path + "/" + item;
if (new_path.back() == '/') {
// Recurse down into a subdirectory.
new_path.pop_back();
std::string result = BrowseDirectory(new_path, device, ui);
if (!result.empty()) return result;
} else {
// Selected a zip file: return the path to the caller.
return new_path;
}
}
// Unreachable.
}
static bool StartSdcardFuse(const std::string& path) {
auto file_data_reader = std::make_unique<FuseFileDataProvider>(path, 65536);
if (!file_data_reader->Valid()) {
return false;
}
// The installation process expects to find the sdcard unmounted. Unmount it with MNT_DETACH so
// that our open file continues to work but new references see it as unmounted.
umount2("/sdcard", MNT_DETACH);
return run_fuse_sideload(std::move(file_data_reader)) == 0;
}
int ApplyFromSdcard(Device* device, bool* wipe_cache, RecoveryUI* ui) {
if (ensure_path_mounted(SDCARD_ROOT) != 0) {
LOG(ERROR) << "\n-- Couldn't mount " << SDCARD_ROOT << ".\n";
return INSTALL_ERROR;
}
std::string path = BrowseDirectory(SDCARD_ROOT, device, ui);
if (path.empty()) {
LOG(ERROR) << "\n-- No package file selected.\n";
ensure_path_unmounted(SDCARD_ROOT);
return INSTALL_ERROR;
}
ui->Print("\n-- Install %s ...\n", path.c_str());
SetSdcardUpdateBootloaderMessage();
// We used to use fuse in a thread as opposed to a process. Since accessing
// through fuse involves going from kernel to userspace to kernel, it leads
// to deadlock when a page fault occurs. (Bug: 26313124)
pid_t child;
if ((child = fork()) == 0) {
bool status = StartSdcardFuse(path);
_exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
}
// FUSE_SIDELOAD_HOST_PATHNAME will start to exist once the fuse in child
// process is ready.
int result = INSTALL_ERROR;
int status;
bool waited = false;
for (int i = 0; i < SDCARD_INSTALL_TIMEOUT; ++i) {
if (waitpid(child, &status, WNOHANG) == -1) {
result = INSTALL_ERROR;
waited = true;
break;
}
struct stat sb;
if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &sb) == -1) {
if (errno == ENOENT && i < SDCARD_INSTALL_TIMEOUT - 1) {
sleep(1);
continue;
} else {
LOG(ERROR) << "Timed out waiting for the fuse-provided package.";
result = INSTALL_ERROR;
kill(child, SIGKILL);
break;
}
}
result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0 /*retry_count*/, ui);
break;
}
if (!waited) {
// Calling stat() on this magic filename signals the fuse
// filesystem to shut down.
struct stat sb;
stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &sb);
waitpid(child, &status, 0);
}
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
LOG(ERROR) << "Error exit from the fuse process: " << WEXITSTATUS(status);
}
ensure_path_unmounted(SDCARD_ROOT);
return result;
}
