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/*
* Copyright (C) 2018 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 "libdm/dm_target.h"
#include <inttypes.h>
#include <stdio.h>
#include <sys/types.h>
#include <android-base/logging.h>
#include <android-base/macros.h>
#include <android-base/parseint.h>
#include <android-base/strings.h>
#include <libdm/dm.h>
namespace android {
namespace dm {
std::string DmTarget::Serialize() const {
// Create a string containing a dm_target_spec, parameter data, and an
// explicit null terminator.
std::string data(sizeof(dm_target_spec), '\0');
data += GetParameterString();
data.push_back('\0');
// The kernel expects each target to be 8-byte aligned.
size_t padding = DM_ALIGN(data.size()) - data.size();
for (size_t i = 0; i < padding; i++) {
data.push_back('\0');
}
// Finally fill in the dm_target_spec.
struct dm_target_spec* spec = reinterpret_cast<struct dm_target_spec*>(&data[0]);
spec->sector_start = start();
spec->length = size();
snprintf(spec->target_type, sizeof(spec->target_type), "%s", name().c_str());
spec->next = (uint32_t)data.size();
return data;
}
std::string DmTargetZero::GetParameterString() const {
// The zero target type has no additional parameters.
return "";
}
std::string DmTargetLinear::GetParameterString() const {
return block_device_ + " " + std::to_string(physical_sector_);
}
DmTargetVerity::DmTargetVerity(uint64_t start, uint64_t length, uint32_t version,
const std::string& block_device, const std::string& hash_device,
uint32_t data_block_size, uint32_t hash_block_size,
uint32_t num_data_blocks, uint32_t hash_start_block,
const std::string& hash_algorithm, const std::string& root_digest,
const std::string& salt)
: DmTarget(start, length), valid_(true) {
base_args_ = {
std::to_string(version),
block_device,
hash_device,
std::to_string(data_block_size),
std::to_string(hash_block_size),
std::to_string(num_data_blocks),
std::to_string(hash_start_block),
hash_algorithm,
root_digest,
salt,
};
}
void DmTargetVerity::UseFec(const std::string& device, uint32_t num_roots, uint32_t num_blocks,
uint32_t start) {
optional_args_.emplace_back("use_fec_from_device");
optional_args_.emplace_back(device);
optional_args_.emplace_back("fec_roots");
optional_args_.emplace_back(std::to_string(num_roots));
optional_args_.emplace_back("fec_blocks");
optional_args_.emplace_back(std::to_string(num_blocks));
optional_args_.emplace_back("fec_start");
optional_args_.emplace_back(std::to_string(start));
}
void DmTargetVerity::SetVerityMode(const std::string& mode) {
if (mode != "panic_on_corruption" &&
mode != "restart_on_corruption" &&
mode != "ignore_corruption") {
LOG(ERROR) << "Unknown verity mode: " << mode;
valid_ = false;
return;
}
optional_args_.emplace_back(mode);
}
void DmTargetVerity::IgnoreZeroBlocks() {
optional_args_.emplace_back("ignore_zero_blocks");
}
void DmTargetVerity::CheckAtMostOnce() {
optional_args_.emplace_back("check_at_most_once");
}
std::string DmTargetVerity::GetParameterString() const {
std::string base = android::base::Join(base_args_, " ");
if (optional_args_.empty()) {
return base;
}
std::string optional = android::base::Join(optional_args_, " ");
return base + " " + std::to_string(optional_args_.size()) + " " + optional;
}
std::string DmTargetAndroidVerity::GetParameterString() const {
return keyid_ + " " + block_device_;
}
std::string DmTargetBow::GetParameterString() const {
if (!block_size_) return target_string_;
return target_string_ + " 1 block_size:" + std::to_string(block_size_);
}
std::string DmTargetSnapshot::name() const {
if (mode_ == SnapshotStorageMode::Merge) {
return "snapshot-merge";
}
return "snapshot";
}
std::string DmTargetSnapshot::GetParameterString() const {
std::string mode;
switch (mode_) {
case SnapshotStorageMode::Persistent:
case SnapshotStorageMode::Merge:
// Note: "O" lets us query for overflow in the status message. This
// is only supported on kernels 4.4+. On earlier kernels, an overflow
// will be reported as "Invalid" in the status string.
mode = "P";
if (ReportsOverflow(name())) {
mode += "O";
}
break;
case SnapshotStorageMode::Transient:
mode = "N";
break;
default:
LOG(ERROR) << "DmTargetSnapshot unknown mode";
break;
}
return base_device_ + " " + cow_device_ + " " + mode + " " + std::to_string(chunk_size_);
}
// Computes the percentage of complition for snapshot status.
// @sectors_initial is the number of sectors_allocated stored right before
// starting the merge.
double DmTargetSnapshot::MergePercent(const DmTargetSnapshot::Status& status,
uint64_t sectors_initial) {
uint64_t s = status.sectors_allocated;
uint64_t t = status.total_sectors;
uint64_t m = status.metadata_sectors;
uint64_t i = sectors_initial == 0 ? t : sectors_initial;
if (t <= s || i <= s) {
return 0.0;
}
if (s == 0 || t == 0 || s <= m) {
return 100.0;
}
return 100.0 / (i - m) * (i - s);
}
bool DmTargetSnapshot::ReportsOverflow(const std::string& target_type) {
DeviceMapper& dm = DeviceMapper::Instance();
DmTargetTypeInfo info;
if (!dm.GetTargetByName(target_type, &info)) {
return false;
}
if (target_type == "snapshot") {
return info.IsAtLeast(1, 15, 0);
}
if (target_type == "snapshot-merge") {
return info.IsAtLeast(1, 4, 0);
}
return false;
}
bool DmTargetSnapshot::ParseStatusText(const std::string& text, Status* status) {
// Try to parse the line as it should be
int args = sscanf(text.c_str(), "%" PRIu64 "/%" PRIu64 " %" PRIu64, &status->sectors_allocated,
&status->total_sectors, &status->metadata_sectors);
if (args == 3) {
return true;
}
auto sections = android::base::Split(text, " ");
if (sections.size() == 0) {
LOG(ERROR) << "could not parse empty status";
return false;
}
// Error codes are: "Invalid", "Overflow" and "Merge failed"
if (sections.size() == 1) {
if (text == "Invalid" || text == "Overflow") {
status->error = text;
return true;
}
} else if (sections.size() == 2 && text == "Merge failed") {
status->error = text;
return true;
}
LOG(ERROR) << "could not parse snapshot status: wrong format";
return false;
}
bool DmTargetSnapshot::GetDevicesFromParams(const std::string& params, std::string* base_device,
std::string* cow_device) {
auto pieces = android::base::Split(params, " ");
if (pieces.size() < 2) {
LOG(ERROR) << "Parameter string is invalid: " << params;
return false;
}
*base_device = pieces[0];
*cow_device = pieces[1];
return true;
}
std::string DmTargetCrypt::GetParameterString() const {
std::vector<std::string> argv = {
cipher_,
key_,
std::to_string(iv_sector_offset_),
device_,
std::to_string(device_sector_),
};
std::vector<std::string> extra_argv;
if (allow_discards_) extra_argv.emplace_back("allow_discards");
if (allow_encrypt_override_) extra_argv.emplace_back("allow_encrypt_override");
if (iv_large_sectors_) extra_argv.emplace_back("iv_large_sectors");
if (sector_size_) extra_argv.emplace_back("sector_size:" + std::to_string(sector_size_));
if (!extra_argv.empty()) argv.emplace_back(std::to_string(extra_argv.size()));
argv.insert(argv.end(), extra_argv.begin(), extra_argv.end());
return android::base::Join(argv, " ");
}
bool DmTargetDefaultKey::Valid() const {
if (!use_legacy_options_format_ && !set_dun_) return false;
return true;
}
std::string DmTargetDefaultKey::GetParameterString() const {
std::vector<std::string> argv;
argv.emplace_back(cipher_);
argv.emplace_back(key_);
if (!use_legacy_options_format_) {
argv.emplace_back("0"); // iv_offset
}
argv.emplace_back(blockdev_);
argv.push_back(std::to_string(start_sector_));
std::vector<std::string> extra_argv;
if (use_legacy_options_format_) {
if (set_dun_) { // v2 always sets the DUN.
extra_argv.emplace_back("set_dun");
}
} else {
extra_argv.emplace_back("allow_discards");
extra_argv.emplace_back("sector_size:4096");
extra_argv.emplace_back("iv_large_sectors");
if (is_hw_wrapped_) extra_argv.emplace_back("wrappedkey_v0");
}
if (!extra_argv.empty()) {
argv.emplace_back(std::to_string(extra_argv.size()));
argv.insert(argv.end(), extra_argv.begin(), extra_argv.end());
}
return android::base::Join(argv, " ");
}
std::string DmTargetUser::GetParameterString() const {
std::vector<std::string> argv;
argv.push_back(std::to_string(start()));
argv.push_back(std::to_string(size()));
argv.push_back(control_device());
return android::base::Join(argv, " ");
}
} // namespace dm
} // namespace android