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// 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
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
#include <sys/stat.h>
#include <sys/types.h>
#include <string>
#include <vector>
#include <brillo/streams/stream.h>
#include "update_engine/common/action.h"
#include "update_engine/common/hash_calculator.h"
#include "update_engine/payload_consumer/install_plan.h"
// This action will hash all the partitions of the target slot involved in the
// update. The hashes are then verified against the ones in the InstallPlan.
// If the target hash does not match, the action will fail. In case of failure,
// the error code will depend on whether the source slot hashes are provided and
// match.
namespace chromeos_update_engine {
// The step FilesystemVerifier is on. On kVerifyTargetHash it computes the hash
// on the target partitions based on the already populated size and verifies it
// matches the one in the target_hash in the InstallPlan.
// If the hash matches, then we skip the kVerifySourceHash step, otherwise we
// need to check if the source is the root cause of the mismatch.
enum class VerifierStep {
class FilesystemVerifierAction : public InstallPlanAction {
FilesystemVerifierAction() = default;
void PerformAction() override;
void TerminateProcessing() override;
// Used for testing. Return true if Cleanup() has not yet been called due
// to a callback upon the completion or cancellation of the verifier action.
// A test should wait until IsCleanupPending() returns false before
// terminating the main loop.
bool IsCleanupPending() const;
// Debugging/logging
static std::string StaticType() { return "FilesystemVerifierAction"; }
std::string Type() const override { return StaticType(); }
// Starts the hashing of the current partition. If there aren't any partitions
// remaining to be hashed, it finishes the action.
void StartPartitionHashing();
// Schedules the asynchronous read of the filesystem.
void ScheduleRead();
// Called from the main loop when a single read from |src_stream_| succeeds or
// fails, calling OnReadDoneCallback() and OnReadErrorCallback() respectively.
void OnReadDoneCallback(size_t bytes_read);
void OnReadErrorCallback(const brillo::Error* error);
// When the read is done, finalize the hash checking of the current partition
// and continue checking the next one.
void FinishPartitionHashing();
// Cleans up all the variables we use for async operations and tells the
// ActionProcessor we're done w/ |code| as passed in. |cancelled_| should be
// true if TerminateProcessing() was called.
void Cleanup(ErrorCode code);
// The type of the partition that we are verifying.
VerifierStep verifier_step_ = VerifierStep::kVerifyTargetHash;
// The index in the install_plan_.partitions vector of the partition currently
// being hashed.
size_t partition_index_{0};
// If not null, the FileStream used to read from the device.
brillo::StreamPtr src_stream_;
// Buffer for storing data we read.
brillo::Blob buffer_;
bool read_done_{false}; // true if reached EOF on the input stream.
bool cancelled_{false}; // true if the action has been cancelled.
// The install plan we're passed in via the input pipe.
InstallPlan install_plan_;
// Calculates the hash of the data.
std::unique_ptr<HashCalculator> hasher_;
// Reads and hashes this many bytes from the head of the input stream. This
// field is initialized from the corresponding InstallPlan::Partition size,
// when the partition starts to be hashed.
int64_t remaining_size_{0};
} // namespace chromeos_update_engine