diff options
Diffstat (limited to 'otautil/roots.cpp')
-rw-r--r-- | otautil/roots.cpp | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/otautil/roots.cpp b/otautil/roots.cpp new file mode 100644 index 000000000..815d644e5 --- /dev/null +++ b/otautil/roots.cpp @@ -0,0 +1,285 @@ +/* + * 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 "otautil/roots.h" + +#include <ctype.h> +#include <fcntl.h> +#include <inttypes.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 <iostream> +#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/roots.h> +#include <fs_mgr_dm_linear.h> + +#include "otautil/mounts.h" +#include "otautil/sysutil.h" + +using android::fs_mgr::Fstab; +using android::fs_mgr::FstabEntry; +using android::fs_mgr::ReadDefaultFstab; + +static Fstab fstab; + +void load_volume_table() { + if (!ReadDefaultFstab(&fstab)) { + LOG(ERROR) << "Failed to read default fstab"; + return; + } + + fstab.emplace_back(FstabEntry{ + .mount_point = "/tmp", .fs_type = "ramdisk", .blk_device = "ramdisk", .length = 0 }); + + std::cout << "recovery filesystem table" << std::endl << "=========================" << std::endl; + for (size_t i = 0; i < fstab.size(); ++i) { + const auto& entry = fstab[i]; + std::cout << " " << i << " " << entry.mount_point << " " + << " " << entry.fs_type << " " << entry.blk_device << " " << entry.length + << std::endl; + } + std::cout << std::endl; +} + +Volume* volume_for_mount_point(const std::string& mount_point) { + return android::fs_mgr::GetEntryForMountPoint(&fstab, mount_point); +} + +// Mount the volume specified by path at the given mount_point. +int ensure_path_mounted_at(const std::string& path, const std::string& mount_point) { + return android::fs_mgr::EnsurePathMounted(&fstab, path, mount_point) ? 0 : -1; +} + +int ensure_path_mounted(const std::string& path) { + // Mount at the default mount point. + return android::fs_mgr::EnsurePathMounted(&fstab, path) ? 0 : -1; +} + +int ensure_path_unmounted(const std::string& path) { + return android::fs_mgr::EnsurePathUnmounted(&fstab, path) ? 0 : -1; +} + +static int exec_cmd(const std::vector<std::string>& args) { + CHECK(!args.empty()); + auto argv = StringVectorToNullTerminatedArray(args); + + 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 std::string& volume, const std::string& directory) { + const FstabEntry* v = android::fs_mgr::GetEntryForPath(&fstab, volume); + if (v == nullptr) { + LOG(ERROR) << "unknown volume \"" << volume << "\""; + return -1; + } + if (v->fs_type == "ramdisk") { + LOG(ERROR) << "can't format_volume \"" << volume << "\""; + return -1; + } + if (v->mount_point != volume) { + 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 (v->fs_type != "ext4" && v->fs_type != "f2fs") { + 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.empty() && v->key_loc[0] == '/') { + LOG(INFO) << "Wiping " << v->key_loc; + int fd = open(v->key_loc.c_str(), 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 == "footer") { + android::base::unique_fd fd(open(v->blk_device.c_str(), 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 (v->fs_type == "ext4") { + 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.empty()) { + 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::vector<std::string> make_f2fs_cmd = { + "/system/bin/make_f2fs", + "-g", + "android", + v->blk_device, + }; + if (length >= kSectorSize) { + make_f2fs_cmd.push_back(std::to_string(length / kSectorSize)); + } + + if (exec_cmd(make_f2fs_cmd) != 0) { + PLOG(ERROR) << "format_volume: Failed to make_f2fs on " << v->blk_device; + return -1; + } + if (!directory.empty()) { + std::vector<std::string> sload_f2fs_cmd = { + "/system/bin/sload_f2fs", "-f", directory, "-t", volume, v->blk_device, + }; + if (exec_cmd(sload_f2fs_cmd) != 0) { + PLOG(ERROR) << "format_volume: Failed to sload_f2fs on " << v->blk_device; + return -1; + } + } + return 0; +} + +int format_volume(const std::string& volume) { + return format_volume(volume, ""); +} + +int setup_install_mounts() { + if (fstab.empty()) { + LOG(ERROR) << "can't set up install mounts: no fstab loaded"; + return -1; + } + for (const FstabEntry& entry : fstab) { + // We don't want to do anything with "/". + if (entry.mount_point == "/") { + continue; + } + + if (entry.mount_point == "/tmp" || entry.mount_point == "/cache") { + if (ensure_path_mounted(entry.mount_point) != 0) { + LOG(ERROR) << "Failed to mount " << entry.mount_point; + return -1; + } + } else { + if (ensure_path_unmounted(entry.mount_point) != 0) { + LOG(ERROR) << "Failed to unmount " << entry.mount_point; + return -1; + } + } + } + return 0; +} + +bool logical_partitions_mapped() { + return android::fs_mgr::LogicalPartitionsMapped(); +} + +std::string get_system_root() { + return android::fs_mgr::GetSystemRoot(); +} |