/*
* 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 <stdlib.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <cryptfs.h>
#include <ext4_utils/wipe.h>
#include <fs_mgr.h>
#include "common.h"
#include "mounts.h"
static struct fstab* fstab = nullptr;
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_path(const char* path) {
return fs_mgr_get_entry_for_mount_point(fstab, path);
}
// 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;
}
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) {
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 char* path, char* const argv[]) {
int status;
pid_t child;
if ((child = vfork()) == 0) {
execv(path, argv);
_exit(EXIT_FAILURE);
}
waitpid(child, &status, 0);
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
LOG(ERROR) << path << " failed with status " << WEXITSTATUS(status);
}
return WEXITSTATUS(status);
}
int format_volume(const char* volume, const char* directory) {
Volume* v = volume_for_path(volume);
if (v == NULL) {
LOG(ERROR) << "unknown volume \"" << volume << "\"";
return -1;
}
if (strcmp(v->fs_type, "ramdisk") == 0) {
// you can't format the ramdisk.
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) {
// 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 != NULL && v->key_loc[0] == '/') {
LOG(INFO) << "wiping " << v->key_loc;
int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
if (fd < 0) {
LOG(ERROR) << "format_volume: failed to open " << v->key_loc;
return -1;
}
wipe_block_device(fd, get_file_size(fd));
close(fd);
}
ssize_t length = 0;
if (v->length != 0) {
length = v->length;
} else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
length = -CRYPT_FOOTER_OFFSET;
}
int result;
if (strcmp(v->fs_type, "ext4") == 0) {
static constexpr int block_size = 4096;
int raid_stride = v->logical_blk_size / block_size;
int raid_stripe_width = v->erase_blk_size / block_size;
// 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 / block_size;
}
const char* mke2fs_argv[] = { "/sbin/mke2fs_static",
"-F",
"-t",
"ext4",
"-b",
nullptr,
nullptr,
nullptr,
nullptr,
nullptr,
nullptr };
int i = 5;
std::string block_size_str = std::to_string(block_size);
mke2fs_argv[i++] = block_size_str.c_str();
std::string ext_args;
if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
ext_args = android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride,
raid_stripe_width);
mke2fs_argv[i++] = "-E";
mke2fs_argv[i++] = ext_args.c_str();
}
mke2fs_argv[i++] = v->blk_device;
std::string size_str = std::to_string(length / block_size);
if (length != 0) {
mke2fs_argv[i++] = size_str.c_str();
}
result = exec_cmd(mke2fs_argv[0], const_cast<char**>(mke2fs_argv));
if (result == 0 && directory != nullptr) {
const char* e2fsdroid_argv[] = { "/sbin/e2fsdroid_static",
"-e",
"-f",
directory,
"-a",
volume,
v->blk_device,
nullptr };
result = exec_cmd(e2fsdroid_argv[0], const_cast<char**>(e2fsdroid_argv));
}
} else { /* Has to be f2fs because we checked earlier. */
if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0 && length < 0) {
LOG(ERROR) << "format_volume: crypt footer + negative length (" << length
<< ") not supported on " << v->fs_type;
return -1;
}
if (length < 0) {
LOG(ERROR) << "format_volume: negative length (" << length
<< ") not supported on " << v->fs_type;
return -1;
}
char *num_sectors = nullptr;
if (length >= 512 && asprintf(&num_sectors, "%zd", length / 512) <= 0) {
LOG(ERROR) << "format_volume: failed to create " << v->fs_type
<< " command for " << v->blk_device;
return -1;
}
const char *f2fs_path = "/sbin/mkfs.f2fs";
const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, nullptr};
result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
free(num_sectors);
}
if (result != 0) {
PLOG(ERROR) << "format_volume: make " << v->fs_type << " failed on " << v->blk_device;
return -1;
}
return 0;
}
LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
return -1;
}
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;
}
