--- services/device/hid/hid_connection_fido.cc.orig 2023-03-09 06:31:50 UTC +++ services/device/hid/hid_connection_fido.cc @@ -0,0 +1,216 @@ +// Copyright 2014 The Chromium Authors +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "services/device/hid/hid_connection_fido.h" + +#include +#include + +#include +#include +#include + +#include "base/files/file_descriptor_watcher_posix.h" +#include "base/memory/ref_counted_memory.h" +#include "base/posix/eintr_wrapper.h" +#include "base/threading/scoped_blocking_call.h" +#include "components/device_event_log/device_event_log.h" +#include "services/device/hid/hid_service.h" + +namespace device { + +class HidConnectionFido::BlockingTaskRunnerHelper { + public: + BlockingTaskRunnerHelper(base::ScopedFD fd, + scoped_refptr device_info, + base::WeakPtr connection) + : fd_(std::move(fd)), + connection_(connection), + origin_task_runner_(base::SequencedTaskRunner::GetCurrentDefault()) { + DETACH_FROM_SEQUENCE(sequence_checker_); + // Report buffers must always have room for the report ID. + report_buffer_size_ = device_info->max_input_report_size() + 1; + has_report_id_ = device_info->has_report_id(); + } + + BlockingTaskRunnerHelper(const BlockingTaskRunnerHelper&) = delete; + BlockingTaskRunnerHelper& operator=(const BlockingTaskRunnerHelper&) = delete; + + ~BlockingTaskRunnerHelper() { + DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); + } + + // Starts the FileDescriptorWatcher that reads input events from the device. + // Must be called on a thread that has a base::MessageLoopForIO. + void Start() { + DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); + + file_watcher_ = base::FileDescriptorWatcher::WatchReadable( + fd_.get(), base::BindRepeating( + &BlockingTaskRunnerHelper::OnFileCanReadWithoutBlocking, + base::Unretained(this))); + } + + void Write(scoped_refptr buffer, + WriteCallback callback) { + DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); + base::ScopedBlockingCall scoped_blocking_call( + FROM_HERE, base::BlockingType::MAY_BLOCK); + + auto data = buffer->front(); + size_t size = buffer->size(); + // if report id is 0, it shouldn't be included + if (data[0] == 0) { + data++; + size--; + } + + ssize_t result = + HANDLE_EINTR(write(fd_.get(), data, size)); + if (result < 0) { + HID_PLOG(EVENT) << "Write failed"; + origin_task_runner_->PostTask(FROM_HERE, + base::BindOnce(std::move(callback), false)); + } else { + if (static_cast(result) != size) { + HID_LOG(EVENT) << "Incomplete HID write: " << result + << " != " << buffer->size(); + } + origin_task_runner_->PostTask(FROM_HERE, + base::BindOnce(std::move(callback), true)); + } + } + + void GetFeatureReport(uint8_t report_id, + scoped_refptr buffer, + ReadCallback callback) { + DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); + base::ScopedBlockingCall scoped_blocking_call( + FROM_HERE, base::BlockingType::MAY_BLOCK); + HID_PLOG(EVENT) << "GendFeatureReport not implemented on OpenBSD"; + origin_task_runner_->PostTask( + FROM_HERE, base::BindOnce(std::move(callback), false, nullptr, 0)); + } + + void SendFeatureReport(scoped_refptr buffer, + WriteCallback callback) { + DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); + base::ScopedBlockingCall scoped_blocking_call( + FROM_HERE, base::BlockingType::MAY_BLOCK); + HID_PLOG(EVENT) << "SendFeatureReport not implemented on OpenBSD"; + origin_task_runner_->PostTask(FROM_HERE, + base::BindOnce(std::move(callback), false)); + } + + private: + void OnFileCanReadWithoutBlocking() { + DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); + + auto buffer = + base::MakeRefCounted(report_buffer_size_); + uint8_t* data = buffer->front(); + size_t length = report_buffer_size_; + if (!has_report_id_) { + // Fido will not prefix the buffer with a report ID if report IDs are not + // used by the device. Prefix the buffer with 0. + *data++ = 0; + length--; + } + + ssize_t bytes_read = HANDLE_EINTR(read(fd_.get(), data, length)); + if (bytes_read < 0) { + if (errno != EAGAIN) { + HID_PLOG(EVENT) << "Read failed"; + // This assumes that the error is unrecoverable and disables reading + // from the device until it has been re-opened. + // TODO(reillyg): Investigate starting and stopping the file descriptor + // watcher in response to pending read requests so that per-request + // errors can be returned to the client. + file_watcher_.reset(); + } + return; + } + if (!has_report_id_) { + // Behave as if the byte prefixed above as the the report ID was read. + bytes_read++; + } + + origin_task_runner_->PostTask( + FROM_HERE, base::BindOnce(&HidConnectionFido::ProcessInputReport, + connection_, buffer, bytes_read)); + } + + SEQUENCE_CHECKER(sequence_checker_); + base::ScopedFD fd_; + size_t report_buffer_size_; + bool has_report_id_; + base::WeakPtr connection_; + const scoped_refptr origin_task_runner_; + std::unique_ptr file_watcher_; +}; + +HidConnectionFido::HidConnectionFido( + scoped_refptr device_info, + base::ScopedFD fd, + scoped_refptr blocking_task_runner, + bool allow_protected_reports, + bool allow_fido_reports) + : HidConnection(device_info, allow_protected_reports, allow_fido_reports), + helper_(nullptr, base::OnTaskRunnerDeleter(blocking_task_runner)), + blocking_task_runner_(std::move(blocking_task_runner)) { + helper_.reset(new BlockingTaskRunnerHelper(std::move(fd), device_info, + weak_factory_.GetWeakPtr())); + blocking_task_runner_->PostTask( + FROM_HERE, base::BindOnce(&BlockingTaskRunnerHelper::Start, + base::Unretained(helper_.get()))); +} + +HidConnectionFido::~HidConnectionFido() {} + +void HidConnectionFido::PlatformClose() { + // By closing the device on the blocking task runner 1) the requirement that + // base::ScopedFD is destroyed on a thread where I/O is allowed is satisfied + // and 2) any tasks posted to this task runner that refer to this file will + // complete before it is closed. + helper_.reset(); +} + +void HidConnectionFido::PlatformWrite( + scoped_refptr buffer, + WriteCallback callback) { + // Fido expects the first byte of the buffer to always be a report ID so the + // buffer can be used directly. + blocking_task_runner_->PostTask( + FROM_HERE, base::BindOnce(&BlockingTaskRunnerHelper::Write, + base::Unretained(helper_.get()), buffer, + std::move(callback))); +} + +void HidConnectionFido::PlatformGetFeatureReport(uint8_t report_id, + ReadCallback callback) { + // The first byte of the destination buffer is the report ID being requested + // and is overwritten by the feature report. + DCHECK_GT(device_info()->max_feature_report_size(), 0u); + auto buffer = base::MakeRefCounted( + device_info()->max_feature_report_size() + 1); + buffer->data()[0] = report_id; + + blocking_task_runner_->PostTask( + FROM_HERE, base::BindOnce(&BlockingTaskRunnerHelper::GetFeatureReport, + base::Unretained(helper_.get()), report_id, + buffer, std::move(callback))); +} + +void HidConnectionFido::PlatformSendFeatureReport( + scoped_refptr buffer, + WriteCallback callback) { + // Fido expects the first byte of the buffer to always be a report ID so the + // buffer can be used directly. + blocking_task_runner_->PostTask( + FROM_HERE, base::BindOnce(&BlockingTaskRunnerHelper::SendFeatureReport, + base::Unretained(helper_.get()), buffer, + std::move(callback))); +} + +} // namespace device