| // |
| // Copyright (C) 2012 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 "update_engine/payload_consumer/filesystem_verifier_action.h" |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include <algorithm> |
| #include <cstdlib> |
| #include <memory> |
| #include <string> |
| #include <utility> |
| |
| #include <base/bind.h> |
| #include <base/strings/string_util.h> |
| #include <brillo/data_encoding.h> |
| #include <brillo/message_loops/message_loop.h> |
| #include <brillo/secure_blob.h> |
| #include <brillo/streams/file_stream.h> |
| |
| #include "common/error_code.h" |
| #include "update_engine/common/utils.h" |
| #include "update_engine/payload_consumer/file_descriptor.h" |
| |
| using brillo::data_encoding::Base64Encode; |
| using std::string; |
| |
| // On a partition with verity enabled, we expect to see the following format: |
| // =================================================== |
| // Normal Filesystem Data |
| // (this should take most of the space, like over 90%) |
| // =================================================== |
| // Hash tree |
| // ~0.8% (e.g. 16M for 2GB image) |
| // =================================================== |
| // FEC data |
| // ~0.8% |
| // =================================================== |
| // Footer |
| // 4K |
| // =================================================== |
| |
| // For OTA that doesn't do on device verity computation, hash tree and fec data |
| // are written during DownloadAction as a regular InstallOp, so no special |
| // handling needed, we can just read the entire partition in 1 go. |
| |
| // Verity enabled case: Only Normal FS data is written during download action. |
| // When hasing the entire partition, we will need to build the hash tree, write |
| // it to disk, then build FEC, and write it to disk. Therefore, it is important |
| // that we finish writing hash tree before we attempt to read & hash it. The |
| // same principal applies to FEC data. |
| |
| // |verity_writer_| handles building and |
| // writing of FEC/HashTree, we just need to be careful when reading. |
| // Specifically, we must stop at beginning of Hash tree, let |verity_writer_| |
| // write both hash tree and FEC, then continue reading the remaining part of |
| // partition. |
| |
| namespace chromeos_update_engine { |
| |
| namespace { |
| const off_t kReadFileBufferSize = 128 * 1024; |
| constexpr float kVerityProgressPercent = 0.6; |
| } // namespace |
| |
| void FilesystemVerifierAction::PerformAction() { |
| // Will tell the ActionProcessor we've failed if we return. |
| ScopedActionCompleter abort_action_completer(processor_, this); |
| |
| if (!HasInputObject()) { |
| LOG(ERROR) << "FilesystemVerifierAction missing input object."; |
| return; |
| } |
| install_plan_ = GetInputObject(); |
| |
| if (install_plan_.partitions.empty()) { |
| LOG(INFO) << "No partitions to verify."; |
| if (HasOutputPipe()) |
| SetOutputObject(install_plan_); |
| abort_action_completer.set_code(ErrorCode::kSuccess); |
| return; |
| } |
| install_plan_.Dump(); |
| StartPartitionHashing(); |
| abort_action_completer.set_should_complete(false); |
| } |
| |
| void FilesystemVerifierAction::TerminateProcessing() { |
| cancelled_ = true; |
| Cleanup(ErrorCode::kSuccess); // error code is ignored if canceled_ is true. |
| } |
| |
| void FilesystemVerifierAction::Cleanup(ErrorCode code) { |
| partition_fd_.reset(); |
| // This memory is not used anymore. |
| buffer_.clear(); |
| |
| // If we didn't write verity, partitions were maped. Releaase resource now. |
| if (!install_plan_.write_verity && |
| dynamic_control_->UpdateUsesSnapshotCompression()) { |
| LOG(INFO) << "Not writing verity and VABC is enabled, unmapping all " |
| "partitions"; |
| dynamic_control_->UnmapAllPartitions(); |
| } |
| |
| if (cancelled_) |
| return; |
| if (code == ErrorCode::kSuccess && HasOutputPipe()) |
| SetOutputObject(install_plan_); |
| UpdateProgress(1.0); |
| processor_->ActionComplete(this, code); |
| } |
| |
| void FilesystemVerifierAction::UpdateProgress(double progress) { |
| if (delegate_ != nullptr) { |
| delegate_->OnVerifyProgressUpdate(progress); |
| } |
| } |
| |
| void FilesystemVerifierAction::UpdatePartitionProgress(double progress) { |
| // We don't consider sizes of each partition. Every partition |
| // has the same length on progress bar. |
| // TODO(b/186087589): Take sizes of each partition into account. |
| UpdateProgress((progress + partition_index_) / |
| install_plan_.partitions.size()); |
| } |
| |
| bool FilesystemVerifierAction::InitializeFdVABC(bool should_write_verity) { |
| const InstallPlan::Partition& partition = |
| install_plan_.partitions[partition_index_]; |
| |
| if (!should_write_verity) { |
| // In VABC, we cannot map/unmap partitions w/o first closing ALL fds first. |
| // Since this function might be called inside a ScheduledTask, the closure |
| // might have a copy of partition_fd_ when executing this function. Which |
| // means even if we do |partition_fd_.reset()| here, there's a chance that |
| // underlying fd isn't closed until we return. This is unacceptable, we need |
| // to close |partition_fd| right away. |
| if (partition_fd_) { |
| partition_fd_->Close(); |
| partition_fd_.reset(); |
| } |
| // In VABC, if we are not writing verity, just map all partitions, |
| // and read using regular fd on |postinstall_mount_device| . |
| // All read will go through snapuserd, which provides a consistent |
| // view: device will use snapuserd to read partition during boot. |
| // b/186196758 |
| // Call UnmapAllPartitions() first, because if we wrote verity before, these |
| // writes won't be visible to previously opened snapuserd daemon. To ensure |
| // that we will see the most up to date data from partitions, call Unmap() |
| // then Map() to re-spin daemon. |
| dynamic_control_->UnmapAllPartitions(); |
| dynamic_control_->MapAllPartitions(); |
| return InitializeFd(partition.readonly_target_path); |
| } |
| partition_fd_ = |
| dynamic_control_->OpenCowFd(partition.name, partition.source_path, true); |
| if (!partition_fd_) { |
| LOG(ERROR) << "OpenCowReader(" << partition.name << ", " |
| << partition.source_path << ") failed."; |
| return false; |
| } |
| partition_size_ = partition.target_size; |
| return true; |
| } |
| |
| bool FilesystemVerifierAction::InitializeFd(const std::string& part_path) { |
| partition_fd_ = std::make_unique<EintrSafeFileDescriptor>(); |
| const bool write_verity = ShouldWriteVerity(); |
| int flags = write_verity ? O_RDWR : O_RDONLY; |
| if (!utils::SetBlockDeviceReadOnly(part_path, !write_verity)) { |
| LOG(WARNING) << "Failed to set block device " << part_path << " as " |
| << (write_verity ? "writable" : "readonly"); |
| } |
| if (!partition_fd_->Open(part_path.c_str(), flags)) { |
| LOG(ERROR) << "Unable to open " << part_path << " for reading."; |
| return false; |
| } |
| return true; |
| } |
| |
| void FilesystemVerifierAction::WriteVerityAndHashPartition( |
| const off64_t start_offset, |
| const off64_t end_offset, |
| void* buffer, |
| const size_t buffer_size) { |
| auto fd = partition_fd_.get(); |
| TEST_AND_RETURN(fd != nullptr); |
| if (start_offset >= end_offset) { |
| LOG_IF(WARNING, start_offset > end_offset) |
| << "start_offset is greater than end_offset : " << start_offset << " > " |
| << end_offset; |
| if (!verity_writer_->Finalize(fd, fd)) { |
| LOG(ERROR) << "Failed to write verity data"; |
| Cleanup(ErrorCode::kVerityCalculationError); |
| return; |
| } |
| if (dynamic_control_->UpdateUsesSnapshotCompression()) { |
| // Spin up snapuserd to read fs. |
| if (!InitializeFdVABC(false)) { |
| LOG(ERROR) << "Failed to map all partitions"; |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| } |
| HashPartition(0, partition_size_, buffer, buffer_size); |
| return; |
| } |
| const auto cur_offset = fd->Seek(start_offset, SEEK_SET); |
| if (cur_offset != start_offset) { |
| PLOG(ERROR) << "Failed to seek to offset: " << start_offset; |
| Cleanup(ErrorCode::kVerityCalculationError); |
| return; |
| } |
| const auto read_size = |
| std::min<size_t>(buffer_size, end_offset - start_offset); |
| const auto bytes_read = fd->Read(buffer, read_size); |
| if (bytes_read < 0 || static_cast<size_t>(bytes_read) != read_size) { |
| PLOG(ERROR) << "Failed to read offset " << start_offset << " expected " |
| << read_size << " bytes, actual: " << bytes_read; |
| Cleanup(ErrorCode::kVerityCalculationError); |
| return; |
| } |
| if (!verity_writer_->Update( |
| start_offset, static_cast<const uint8_t*>(buffer), read_size)) { |
| LOG(ERROR) << "VerityWriter::Update() failed"; |
| Cleanup(ErrorCode::kVerityCalculationError); |
| return; |
| } |
| UpdatePartitionProgress((start_offset + bytes_read) * 1.0f / partition_size_ * |
| kVerityProgressPercent); |
| CHECK(pending_task_id_.PostTask( |
| FROM_HERE, |
| base::BindOnce(&FilesystemVerifierAction::WriteVerityAndHashPartition, |
| base::Unretained(this), |
| start_offset + bytes_read, |
| end_offset, |
| buffer, |
| buffer_size))); |
| } |
| |
| void FilesystemVerifierAction::HashPartition(const off64_t start_offset, |
| const off64_t end_offset, |
| void* buffer, |
| const size_t buffer_size) { |
| auto fd = partition_fd_.get(); |
| TEST_AND_RETURN(fd != nullptr); |
| if (start_offset >= end_offset) { |
| LOG_IF(WARNING, start_offset > end_offset) |
| << "start_offset is greater than end_offset : " << start_offset << " > " |
| << end_offset; |
| FinishPartitionHashing(); |
| return; |
| } |
| const auto cur_offset = fd->Seek(start_offset, SEEK_SET); |
| if (cur_offset != start_offset) { |
| PLOG(ERROR) << "Failed to seek to offset: " << start_offset; |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| const auto read_size = |
| std::min<size_t>(buffer_size, end_offset - start_offset); |
| const auto bytes_read = fd->Read(buffer, read_size); |
| if (bytes_read < 0 || static_cast<size_t>(bytes_read) != read_size) { |
| PLOG(ERROR) << "Failed to read offset " << start_offset << " expected " |
| << read_size << " bytes, actual: " << bytes_read; |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| if (!hasher_->Update(buffer, read_size)) { |
| LOG(ERROR) << "Hasher updated failed on offset" << start_offset; |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| const auto progress = (start_offset + bytes_read) * 1.0f / partition_size_; |
| UpdatePartitionProgress(progress * (1 - kVerityProgressPercent) + |
| kVerityProgressPercent); |
| CHECK(pending_task_id_.PostTask( |
| FROM_HERE, |
| base::BindOnce(&FilesystemVerifierAction::HashPartition, |
| base::Unretained(this), |
| start_offset + bytes_read, |
| end_offset, |
| buffer, |
| buffer_size))); |
| } |
| |
| void FilesystemVerifierAction::StartPartitionHashing() { |
| if (partition_index_ == install_plan_.partitions.size()) { |
| if (!install_plan_.untouched_dynamic_partitions.empty()) { |
| LOG(INFO) << "Verifying extents of untouched dynamic partitions [" |
| << base::JoinString(install_plan_.untouched_dynamic_partitions, |
| ", ") |
| << "]"; |
| if (!dynamic_control_->VerifyExtentsForUntouchedPartitions( |
| install_plan_.source_slot, |
| install_plan_.target_slot, |
| install_plan_.untouched_dynamic_partitions)) { |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| } |
| |
| Cleanup(ErrorCode::kSuccess); |
| return; |
| } |
| const InstallPlan::Partition& partition = |
| install_plan_.partitions[partition_index_]; |
| const auto& part_path = GetPartitionPath(); |
| partition_size_ = GetPartitionSize(); |
| |
| LOG(INFO) << "Hashing partition " << partition_index_ << " (" |
| << partition.name << ") on device " << part_path; |
| auto success = false; |
| if (IsVABC(partition)) { |
| success = InitializeFdVABC(ShouldWriteVerity()); |
| } else { |
| if (part_path.empty()) { |
| if (partition_size_ == 0) { |
| LOG(INFO) << "Skip hashing partition " << partition_index_ << " (" |
| << partition.name << ") because size is 0."; |
| partition_index_++; |
| StartPartitionHashing(); |
| return; |
| } |
| LOG(ERROR) << "Cannot hash partition " << partition_index_ << " (" |
| << partition.name |
| << ") because its device path cannot be determined."; |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| success = InitializeFd(part_path); |
| } |
| if (!success) { |
| Cleanup(ErrorCode::kFilesystemVerifierError); |
| return; |
| } |
| buffer_.resize(kReadFileBufferSize); |
| hasher_ = std::make_unique<HashCalculator>(); |
| |
| offset_ = 0; |
| filesystem_data_end_ = partition_size_; |
| if (partition.fec_offset > 0) { |
| CHECK_LE(partition.hash_tree_offset, partition.fec_offset) |
| << " Hash tree is expected to come before FEC data"; |
| } |
| CHECK_NE(partition_fd_, nullptr); |
| if (partition.hash_tree_offset != 0) { |
| filesystem_data_end_ = partition.hash_tree_offset; |
| } else if (partition.fec_offset != 0) { |
| filesystem_data_end_ = partition.fec_offset; |
| } |
| if (ShouldWriteVerity()) { |
| LOG(INFO) << "Verity writes enabled on partition " << partition.name; |
| if (!verity_writer_->Init(partition)) { |
| LOG(INFO) << "Verity writes enabled on partition " << partition.name; |
| Cleanup(ErrorCode::kVerityCalculationError); |
| return; |
| } |
| WriteVerityAndHashPartition( |
| 0, filesystem_data_end_, buffer_.data(), buffer_.size()); |
| } else { |
| LOG(INFO) << "Verity writes disabled on partition " << partition.name; |
| HashPartition(0, partition_size_, buffer_.data(), buffer_.size()); |
| } |
| } |
| |
| bool FilesystemVerifierAction::IsVABC( |
| const InstallPlan::Partition& partition) const { |
| return dynamic_control_->UpdateUsesSnapshotCompression() && |
| verifier_step_ == VerifierStep::kVerifyTargetHash && |
| dynamic_control_->IsDynamicPartition(partition.name, |
| install_plan_.target_slot); |
| } |
| |
| const std::string& FilesystemVerifierAction::GetPartitionPath() const { |
| const InstallPlan::Partition& partition = |
| install_plan_.partitions[partition_index_]; |
| switch (verifier_step_) { |
| case VerifierStep::kVerifySourceHash: |
| return partition.source_path; |
| case VerifierStep::kVerifyTargetHash: |
| if (IsVABC(partition)) { |
| return partition.readonly_target_path; |
| } else { |
| return partition.target_path; |
| } |
| } |
| } |
| |
| size_t FilesystemVerifierAction::GetPartitionSize() const { |
| const InstallPlan::Partition& partition = |
| install_plan_.partitions[partition_index_]; |
| switch (verifier_step_) { |
| case VerifierStep::kVerifySourceHash: |
| return partition.source_size; |
| case VerifierStep::kVerifyTargetHash: |
| return partition.target_size; |
| } |
| } |
| |
| bool FilesystemVerifierAction::ShouldWriteVerity() { |
| const InstallPlan::Partition& partition = |
| install_plan_.partitions[partition_index_]; |
| return verifier_step_ == VerifierStep::kVerifyTargetHash && |
| install_plan_.write_verity && |
| (partition.hash_tree_size > 0 || partition.fec_size > 0); |
| } |
| |
| void FilesystemVerifierAction::FinishPartitionHashing() { |
| if (!hasher_->Finalize()) { |
| LOG(ERROR) << "Unable to finalize the hash."; |
| Cleanup(ErrorCode::kError); |
| return; |
| } |
| const InstallPlan::Partition& partition = |
| install_plan_.partitions[partition_index_]; |
| LOG(INFO) << "Hash of " << partition.name << ": " |
| << HexEncode(hasher_->raw_hash()); |
| |
| switch (verifier_step_) { |
| case VerifierStep::kVerifyTargetHash: |
| if (partition.target_hash != hasher_->raw_hash()) { |
| LOG(ERROR) << "New '" << partition.name |
| << "' partition verification failed."; |
| if (partition.source_hash.empty()) { |
| // No need to verify source if it is a full payload. |
| Cleanup(ErrorCode::kNewRootfsVerificationError); |
| return; |
| } |
| // If we have not verified source partition yet, now that the target |
| // partition does not match, and it's not a full payload, we need to |
| // switch to kVerifySourceHash step to check if it's because the |
| // source partition does not match either. |
| verifier_step_ = VerifierStep::kVerifySourceHash; |
| } else { |
| partition_index_++; |
| } |
| break; |
| case VerifierStep::kVerifySourceHash: |
| if (partition.source_hash != hasher_->raw_hash()) { |
| LOG(ERROR) << "Old '" << partition.name |
| << "' partition verification failed."; |
| LOG(ERROR) << "This is a server-side error due to mismatched delta" |
| << " update image!"; |
| LOG(ERROR) << "The delta I've been given contains a " << partition.name |
| << " delta update that must be applied over a " |
| << partition.name << " with a specific checksum, but the " |
| << partition.name |
| << " we're starting with doesn't have that checksum! This" |
| " means that the delta I've been given doesn't match my" |
| " existing system. The " |
| << partition.name << " partition I have has hash: " |
| << Base64Encode(hasher_->raw_hash()) |
| << " but the update expected me to have " |
| << Base64Encode(partition.source_hash) << " ."; |
| LOG(INFO) << "To get the checksum of the " << partition.name |
| << " partition run this command: dd if=" |
| << partition.source_path |
| << " bs=1M count=" << partition.source_size |
| << " iflag=count_bytes 2>/dev/null | openssl dgst -sha256 " |
| "-binary | openssl base64"; |
| LOG(INFO) << "To get the checksum of partitions in a bin file, " |
| << "run: .../src/scripts/sha256_partitions.sh .../file.bin"; |
| Cleanup(ErrorCode::kDownloadStateInitializationError); |
| return; |
| } |
| // The action will skip kVerifySourceHash step if target partition hash |
| // matches, if we are in this step, it means target hash does not match, |
| // and now that the source partition hash matches, we should set the |
| // error code to reflect the error in target partition. We only need to |
| // verify the source partition which the target hash does not match, the |
| // rest of the partitions don't matter. |
| Cleanup(ErrorCode::kNewRootfsVerificationError); |
| return; |
| } |
| // Start hashing the next partition, if any. |
| buffer_.clear(); |
| if (partition_fd_) { |
| partition_fd_->Close(); |
| partition_fd_.reset(); |
| } |
| StartPartitionHashing(); |
| } |
| |
| } // namespace chromeos_update_engine |