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/*
* Copyright (C) 2007 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 "roots.h"
#include <ctype.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <algorithm>
#include <string>
#include <vector>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <cryptfs.h>
#include <ext4_utils/wipe.h>
#include <fs_mgr.h>
#include <fs_mgr_dm_linear.h>
#include "otautil/mounts.h"
static struct fstab* fstab = nullptr;
static bool did_map_logical_partitions = false;
extern struct selabel_handle* sehandle;
void load_volume_table() {
fstab = fs_mgr_read_fstab_default();
if (!fstab) {
LOG(ERROR) << "Failed to read default fstab";
return;
}
int ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
if (ret == -1) {
LOG(ERROR) << "Failed to add /tmp entry to fstab";
fs_mgr_free_fstab(fstab);
fstab = nullptr;
return;
}
printf("recovery filesystem table\n");
printf("=========================\n");
for (int i = 0; i < fstab->num_entries; ++i) {
const Volume* v = &fstab->recs[i];
printf(" %d %s %s %s %lld\n", i, v->mount_point, v->fs_type, v->blk_device, v->length);
}
printf("\n");
}
Volume* volume_for_mount_point(const std::string& mount_point) {
return fs_mgr_get_entry_for_mount_point(fstab, mount_point);
}
// Finds the volume specified by the given path. fs_mgr_get_entry_for_mount_point() does exact match
// only, so it attempts the prefixes recursively (e.g. "/cache/recovery/last_log",
// "/cache/recovery", "/cache", "/" for a given path of "/cache/recovery/last_log") and returns the
// first match or nullptr.
static Volume* volume_for_path(const char* path) {
if (path == nullptr || path[0] == '\0') return nullptr;
std::string str(path);
while (true) {
Volume* result = fs_mgr_get_entry_for_mount_point(fstab, str);
if (result != nullptr || str == "/") {
return result;
}
size_t slash = str.find_last_of('/');
if (slash == std::string::npos) return nullptr;
if (slash == 0) {
str = "/";
} else {
str = str.substr(0, slash);
}
}
return nullptr;
}
// Mount the volume specified by path at the given mount_point.
int ensure_path_mounted_at(const char* path, const char* mount_point) {
Volume* v = volume_for_path(path);
if (v == nullptr) {
LOG(ERROR) << "unknown volume for path [" << path << "]";
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
// The ramdisk is always mounted.
return 0;
}
if (!scan_mounted_volumes()) {
LOG(ERROR) << "Failed to scan mounted volumes";
return -1;
}
if (!mount_point) {
mount_point = v->mount_point;
}
// If we can't acquire the block device for a logical partition, it likely
// was never created. In that case we try to create it.
if (fs_mgr_is_logical(v) && !fs_mgr_update_logical_partition(v)) {
if (did_map_logical_partitions) {
LOG(ERROR) << "Failed to find block device for partition";
return -1;
}
std::string super_name = fs_mgr_get_super_partition_name();
if (!android::fs_mgr::CreateLogicalPartitions(super_name)) {
LOG(ERROR) << "Failed to create logical partitions";
return -1;
}
did_map_logical_partitions = true;
if (!fs_mgr_update_logical_partition(v)) {
LOG(ERROR) << "Failed to find block device for partition";
return -1;
}
}
const MountedVolume* mv = find_mounted_volume_by_mount_point(mount_point);
if (mv != nullptr) {
// Volume is already mounted.
return 0;
}
mkdir(mount_point, 0755); // in case it doesn't already exist
if (strcmp(v->fs_type, "ext4") == 0 || strcmp(v->fs_type, "squashfs") == 0 ||
strcmp(v->fs_type, "vfat") == 0 || strcmp(v->fs_type, "f2fs") == 0) {
int result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
if (result == -1 && fs_mgr_is_formattable(v)) {
PLOG(ERROR) << "Failed to mount " << mount_point << "; formatting";
bool crypt_footer = fs_mgr_is_encryptable(v) && !strcmp(v->key_loc, "footer");
if (fs_mgr_do_format(v, crypt_footer) == 0) {
result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
} else {
PLOG(ERROR) << "Failed to format " << mount_point;
return -1;
}
}
if (result == -1) {
PLOG(ERROR) << "Failed to mount " << mount_point;
return -1;
}
return 0;
}
LOG(ERROR) << "unknown fs_type \"" << v->fs_type << "\" for " << mount_point;
return -1;
}
int ensure_path_mounted(const char* path) {
// Mount at the default mount point.
return ensure_path_mounted_at(path, nullptr);
}
int ensure_path_unmounted(const char* path) {
const Volume* v = volume_for_path(path);
if (v == nullptr) {
LOG(ERROR) << "unknown volume for path [" << path << "]";
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
// The ramdisk is always mounted; you can't unmount it.
return -1;
}
if (!scan_mounted_volumes()) {
LOG(ERROR) << "Failed to scan mounted volumes";
return -1;
}
MountedVolume* mv = find_mounted_volume_by_mount_point(v->mount_point);
if (mv == nullptr) {
// Volume is already unmounted.
return 0;
}
return unmount_mounted_volume(mv);
}
static int exec_cmd(const std::vector<std::string>& args) {
CHECK_NE(static_cast<size_t>(0), args.size());
std::vector<char*> argv(args.size());
std::transform(args.cbegin(), args.cend(), argv.begin(),
[](const std::string& arg) { return const_cast<char*>(arg.c_str()); });
argv.push_back(nullptr);
pid_t child;
if ((child = fork()) == 0) {
execv(argv[0], argv.data());
_exit(EXIT_FAILURE);
}
int status;
waitpid(child, &status, 0);
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
LOG(ERROR) << args[0] << " failed with status " << WEXITSTATUS(status);
}
return WEXITSTATUS(status);
}
static int64_t get_file_size(int fd, uint64_t reserve_len) {
struct stat buf;
int ret = fstat(fd, &buf);
if (ret) return 0;
int64_t computed_size;
if (S_ISREG(buf.st_mode)) {
computed_size = buf.st_size - reserve_len;
} else if (S_ISBLK(buf.st_mode)) {
uint64_t block_device_size = get_block_device_size(fd);
if (block_device_size < reserve_len ||
block_device_size > std::numeric_limits<int64_t>::max()) {
computed_size = 0;
} else {
computed_size = block_device_size - reserve_len;
}
} else {
computed_size = 0;
}
return computed_size;
}
int format_volume(const char* volume, const char* directory) {
const Volume* v = volume_for_path(volume);
if (v == nullptr) {
LOG(ERROR) << "unknown volume \"" << volume << "\"";
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
LOG(ERROR) << "can't format_volume \"" << volume << "\"";
return -1;
}
if (strcmp(v->mount_point, volume) != 0) {
LOG(ERROR) << "can't give path \"" << volume << "\" to format_volume";
return -1;
}
if (ensure_path_unmounted(volume) != 0) {
LOG(ERROR) << "format_volume: Failed to unmount \"" << v->mount_point << "\"";
return -1;
}
if (strcmp(v->fs_type, "ext4") != 0 && strcmp(v->fs_type, "f2fs") != 0) {
LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
return -1;
}
// If there's a key_loc that looks like a path, it should be a block device for storing encryption
// metadata. Wipe it too.
if (v->key_loc != nullptr && v->key_loc[0] == '/') {
LOG(INFO) << "Wiping " << v->key_loc;
int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
if (fd == -1) {
PLOG(ERROR) << "format_volume: Failed to open " << v->key_loc;
return -1;
}
wipe_block_device(fd, get_file_size(fd));
close(fd);
}
int64_t length = 0;
if (v->length > 0) {
length = v->length;
} else if (v->length < 0 ||
(v->key_loc != nullptr && strcmp(v->key_loc, "footer") == 0)) {
android::base::unique_fd fd(open(v->blk_device, O_RDONLY));
if (fd == -1) {
PLOG(ERROR) << "format_volume: failed to open " << v->blk_device;
return -1;
}
length =
get_file_size(fd.get(), v->length ? -v->length : CRYPT_FOOTER_OFFSET);
if (length <= 0) {
LOG(ERROR) << "get_file_size: invalid size " << length << " for "
<< v->blk_device;
return -1;
}
}
if (strcmp(v->fs_type, "ext4") == 0) {
static constexpr int kBlockSize = 4096;
std::vector<std::string> mke2fs_args = {
"/system/bin/mke2fs", "-F", "-t", "ext4", "-b", std::to_string(kBlockSize),
};
int raid_stride = v->logical_blk_size / kBlockSize;
int raid_stripe_width = v->erase_blk_size / kBlockSize;
// stride should be the max of 8KB and logical block size
if (v->logical_blk_size != 0 && v->logical_blk_size < 8192) {
raid_stride = 8192 / kBlockSize;
}
if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
mke2fs_args.push_back("-E");
mke2fs_args.push_back(
android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride, raid_stripe_width));
}
mke2fs_args.push_back(v->blk_device);
if (length != 0) {
mke2fs_args.push_back(std::to_string(length / kBlockSize));
}
int result = exec_cmd(mke2fs_args);
if (result == 0 && directory != nullptr) {
std::vector<std::string> e2fsdroid_args = {
"/system/bin/e2fsdroid", "-e", "-f", directory, "-a", volume, v->blk_device,
};
result = exec_cmd(e2fsdroid_args);
}
if (result != 0) {
PLOG(ERROR) << "format_volume: Failed to make ext4 on " << v->blk_device;
return -1;
}
return 0;
}
// Has to be f2fs because we checked earlier.
static constexpr int kSectorSize = 4096;
std::string cmd("/sbin/mkfs.f2fs");
// clang-format off
std::vector<std::string> make_f2fs_cmd = {
cmd,
"-g", "android",
v->blk_device,
};
// clang-format on
if (length >= kSectorSize) {
make_f2fs_cmd.push_back(std::to_string(length / kSectorSize));
}
int result = exec_cmd(make_f2fs_cmd);
if (result == 0 && directory != nullptr) {
cmd = "/sbin/sload.f2fs";
// clang-format off
std::vector<std::string> sload_f2fs_cmd = {
cmd,
"-f", directory,
"-t", volume,
v->blk_device,
};
// clang-format on
result = exec_cmd(sload_f2fs_cmd);
}
if (result != 0) {
PLOG(ERROR) << "format_volume: Failed " << cmd << " on " << v->blk_device;
return -1;
}
return 0;
}
int format_volume(const char* volume) {
return format_volume(volume, nullptr);
}
int setup_install_mounts() {
if (fstab == nullptr) {
LOG(ERROR) << "can't set up install mounts: no fstab loaded";
return -1;
}
for (int i = 0; i < fstab->num_entries; ++i) {
const Volume* v = fstab->recs + i;
// We don't want to do anything with "/".
if (strcmp(v->mount_point, "/") == 0) {
continue;
}
if (strcmp(v->mount_point, "/tmp") == 0 || strcmp(v->mount_point, "/cache") == 0) {
if (ensure_path_mounted(v->mount_point) != 0) {
LOG(ERROR) << "Failed to mount " << v->mount_point;
return -1;
}
} else {
if (ensure_path_unmounted(v->mount_point) != 0) {
LOG(ERROR) << "Failed to unmount " << v->mount_point;
return -1;
}
}
}
return 0;
}
bool logical_partitions_mapped() {
return did_map_logical_partitions;
}