services/device/hid/hid_service_linux.cc - chromium/src - Git at Google

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // 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_service_linux.h"

 #include <fcntl.h>
 #include <stdint.h>

 #include <limits>
 #include <memory>
 #include <string>
 #include <utility>

 #include "base/bind.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/sequence_checker.h"
 #include "base/sequenced_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "components/device_event_log/device_event_log.h"
 #include "device/udev_linux/scoped_udev.h"
 #include "device/udev_linux/udev_watcher.h"
 #include "services/device/hid/hid_connection_linux.h"

 #if defined(OS_CHROMEOS)
 #include "base/sys_info.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/permission_broker_client.h"
 #endif  // defined(OS_CHROMEOS)

 namespace device {

 namespace {

 const char kHidrawSubsystem[] = "hidraw";
 const char kHIDID[] = "HID_ID";
 const char kHIDName[] = "HID_NAME";
 const char kHIDUnique[] = "HID_UNIQ";
 const char kSysfsReportDescriptorKey[] = "report_descriptor";

 }  // namespace

 struct HidServiceLinux::ConnectParams {
   ConnectParams(scoped_refptr<HidDeviceInfo> device_info,
                 const ConnectCallback& callback)
       : device_info(std::move(device_info)),
         callback(callback),
         task_runner(base::ThreadTaskRunnerHandle::Get()),
         blocking_task_runner(
             base::CreateSequencedTaskRunnerWithTraits(kBlockingTaskTraits)) {}
   ~ConnectParams() {}

   scoped_refptr<HidDeviceInfo> device_info;
   ConnectCallback callback;
   scoped_refptr<base::SequencedTaskRunner> task_runner;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner;
   base::ScopedFD fd;
 };

 class HidServiceLinux::BlockingTaskHelper : public UdevWatcher::Observer {
  public:
   BlockingTaskHelper(base::WeakPtr<HidServiceLinux> service)
       : service_(std::move(service)),
         task_runner_(base::ThreadTaskRunnerHandle::Get()) {
     DETACH_FROM_SEQUENCE(sequence_checker_);
   }

   ~BlockingTaskHelper() override {
     DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   }

   void Start() {
     base::AssertBlockingAllowed();
     DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

     watcher_ = UdevWatcher::StartWatching(this);
     watcher_->EnumerateExistingDevices();
     task_runner_->PostTask(
         FROM_HERE,
         base::BindOnce(&HidServiceLinux::FirstEnumerationComplete, service_));
   }

  private:
   // UdevWatcher::Observer
   void OnDeviceAdded(ScopedUdevDevicePtr device) override {
     DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     const char* device_path = udev_device_get_syspath(device.get());
     if (!device_path)
       return;
     HidPlatformDeviceId platform_device_id = device_path;

     const char* subsystem = udev_device_get_subsystem(device.get());
     if (!subsystem || strcmp(subsystem, kHidrawSubsystem) != 0)
       return;

     const char* str_property = udev_device_get_devnode(device.get());
     if (!str_property)
       return;
     std::string device_node = str_property;

     udev_device* parent = udev_device_get_parent(device.get());
     if (!parent)
       return;

     const char* hid_id = udev_device_get_property_value(parent, kHIDID);
     if (!hid_id)
       return;

     std::vector<std::string> parts = base::SplitString(
         hid_id, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
     if (parts.size() != 3)
       return;

     uint32_t int_property = 0;
     if (!HexStringToUInt(base::StringPiece(parts[1]), &int_property) ||
         int_property > std::numeric_limits<uint16_t>::max()) {
       return;
     }
     uint16_t vendor_id = int_property;

     if (!HexStringToUInt(base::StringPiece(parts[2]), &int_property) ||
         int_property > std::numeric_limits<uint16_t>::max()) {
       return;
     }
     uint16_t product_id = int_property;

     std::string serial_number;
     str_property = udev_device_get_property_value(parent, kHIDUnique);
     if (str_property)
       serial_number = str_property;

     std::string product_name;
     str_property = udev_device_get_property_value(parent, kHIDName);
     if (str_property)
       product_name = str_property;

     const char* parent_sysfs_path = udev_device_get_syspath(parent);
     if (!parent_sysfs_path)
       return;
     base::FilePath report_descriptor_path =
         base::FilePath(parent_sysfs_path).Append(kSysfsReportDescriptorKey);
     std::string report_descriptor_str;
     if (!base::ReadFileToString(report_descriptor_path, &report_descriptor_str))
       return;

     scoped_refptr<HidDeviceInfo> device_info(new HidDeviceInfo(
         platform_device_id, vendor_id, product_id, product_name, serial_number,
         // TODO(reillyg): Detect Bluetooth. crbug.com/443335
         mojom::HidBusType::kHIDBusTypeUSB,
         std::vector<uint8_t>(report_descriptor_str.begin(),
                              report_descriptor_str.end()),
         device_node));

     task_runner_->PostTask(
         FROM_HERE,
         base::BindOnce(&HidServiceLinux::AddDevice, service_, device_info));
   }

   void OnDeviceRemoved(ScopedUdevDevicePtr device) override {
     DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     const char* device_path = udev_device_get_syspath(device.get());
     if (device_path) {
       task_runner_->PostTask(
           FROM_HERE, base::BindOnce(&HidServiceLinux::RemoveDevice, service_,
                                     std::string(device_path)));
     }
   }

   SEQUENCE_CHECKER(sequence_checker_);
   std::unique_ptr<UdevWatcher> watcher_;

   // This weak pointer is only valid when checked on this task runner.
   base::WeakPtr<HidServiceLinux> service_;
   scoped_refptr<base::SequencedTaskRunner> task_runner_;

   DISALLOW_COPY_AND_ASSIGN(BlockingTaskHelper);
 };

 HidServiceLinux::HidServiceLinux()
     : blocking_task_runner_(
           base::CreateSequencedTaskRunnerWithTraits(kBlockingTaskTraits)),
       weak_factory_(this) {
   helper_ = std::make_unique<BlockingTaskHelper>(weak_factory_.GetWeakPtr());
   blocking_task_runner_->PostTask(
       FROM_HERE, base::BindOnce(&BlockingTaskHelper::Start,
                                 base::Unretained(helper_.get())));
 }

 HidServiceLinux::~HidServiceLinux() {
   blocking_task_runner_->DeleteSoon(FROM_HERE, helper_.release());
 }

 base::WeakPtr<HidService> HidServiceLinux::GetWeakPtr() {
   return weak_factory_.GetWeakPtr();
 }

 void HidServiceLinux::Connect(const std::string& device_guid,
                               const ConnectCallback& callback) {
   DCHECK(thread_checker_.CalledOnValidThread());

   const auto& map_entry = devices().find(device_guid);
   if (map_entry == devices().end()) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(callback, nullptr));
     return;
   }
   scoped_refptr<HidDeviceInfo> device_info = map_entry->second;

   auto params = std::make_unique<ConnectParams>(device_info, callback);

 #if defined(OS_CHROMEOS)
   chromeos::PermissionBrokerClient* client =
       chromeos::DBusThreadManager::Get()->GetPermissionBrokerClient();
   DCHECK(client) << "Could not get permission broker client.";
   chromeos::PermissionBrokerClient::ErrorCallback error_callback =
       base::Bind(&HidServiceLinux::OnPathOpenError,
                  params->device_info->device_node(), params->callback);
   client->OpenPath(
       device_info->device_node(),
       base::Bind(&HidServiceLinux::OnPathOpenComplete, base::Passed(&params)),
       error_callback);
 #else
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner =
       params->blocking_task_runner;
   blocking_task_runner->PostTask(
       FROM_HERE, base::BindOnce(&HidServiceLinux::OpenOnBlockingThread,
                                 std::move(params)));
 #endif  // defined(OS_CHROMEOS)
 }

 #if defined(OS_CHROMEOS)

 // static
 void HidServiceLinux::OnPathOpenComplete(std::unique_ptr<ConnectParams> params,
                                          base::ScopedFD fd) {
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner =
       params->blocking_task_runner;
   params->fd = std::move(fd);
   blocking_task_runner->PostTask(
       FROM_HERE,
       base::BindOnce(&HidServiceLinux::FinishOpen, std::move(params)));
 }

 // static
 void HidServiceLinux::OnPathOpenError(const std::string& device_path,
                                       const ConnectCallback& callback,
                                       const std::string& error_name,
                                       const std::string& error_message) {
   HID_LOG(EVENT) << "Permission broker failed to open '" << device_path
                  << "': " << error_name << ": " << error_message;
   callback.Run(nullptr);
 }

 #else

 // static
 void HidServiceLinux::OpenOnBlockingThread(
     std::unique_ptr<ConnectParams> params) {
   base::AssertBlockingAllowed();
   scoped_refptr<base::SequencedTaskRunner> task_runner = params->task_runner;

   base::FilePath device_path(params->device_info->device_node());
   base::File device_file;
   int flags =
       base::File::FLAG_OPEN | base::File::FLAG_READ | base::File::FLAG_WRITE;
   device_file.Initialize(device_path, flags);
   if (!device_file.IsValid()) {
     base::File::Error file_error = device_file.error_details();

     if (file_error == base::File::FILE_ERROR_ACCESS_DENIED) {
       HID_LOG(EVENT)
           << "Access denied opening device read-write, trying read-only.";
       flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
       device_file.Initialize(device_path, flags);
     }
   }
   if (!device_file.IsValid()) {
     HID_LOG(EVENT) << "Failed to open '" << params->device_info->device_node()
                    << "': "
                    << base::File::ErrorToString(device_file.error_details());
     task_runner->PostTask(FROM_HERE, base::BindOnce(params->callback, nullptr));
     return;
   }
   params->fd.reset(device_file.TakePlatformFile());
   FinishOpen(std::move(params));
 }

 #endif  // defined(OS_CHROMEOS)

 // static
 void HidServiceLinux::FinishOpen(std::unique_ptr<ConnectParams> params) {
   base::AssertBlockingAllowed();
   scoped_refptr<base::SequencedTaskRunner> task_runner = params->task_runner;

   if (!base::SetNonBlocking(params->fd.get())) {
     HID_PLOG(ERROR) << "Failed to set the non-blocking flag on the device fd";
     task_runner->PostTask(FROM_HERE, base::BindOnce(params->callback, nullptr));
     return;
   }

   task_runner->PostTask(
       FROM_HERE,
       base::BindOnce(&HidServiceLinux::CreateConnection, std::move(params)));
 }

 // static
 void HidServiceLinux::CreateConnection(std::unique_ptr<ConnectParams> params) {
   DCHECK(params->fd.is_valid());
   params->callback.Run(base::MakeRefCounted<HidConnectionLinux>(
       std::move(params->device_info), std::move(params->fd),
       std::move(params->blocking_task_runner)));
 }

 }  // namespace device
	// Copyright 2014 The Chromium Authors. All rights reserved.
	// 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_service_linux.h"

	#include <fcntl.h>
	#include <stdint.h>

	#include <limits>
	#include <memory>
	#include <string>
	#include <utility>

	#include "base/bind.h"
	#include "base/files/file.h"
	#include "base/files/file_path.h"
	#include "base/files/file_util.h"
	#include "base/files/scoped_file.h"
	#include "base/location.h"
	#include "base/macros.h"
	#include "base/memory/ptr_util.h"
	#include "base/sequence_checker.h"
	#include "base/sequenced_task_runner.h"
	#include "base/strings/string_number_conversions.h"
	#include "base/strings/string_split.h"
	#include "base/task_scheduler/post_task.h"
	#include "base/threading/thread_restrictions.h"
	#include "base/threading/thread_task_runner_handle.h"
	#include "build/build_config.h"
	#include "components/device_event_log/device_event_log.h"
	#include "device/udev_linux/scoped_udev.h"
	#include "device/udev_linux/udev_watcher.h"
	#include "services/device/hid/hid_connection_linux.h"

	#if defined(OS_CHROMEOS)
	#include "base/sys_info.h"
	#include "chromeos/dbus/dbus_thread_manager.h"
	#include "chromeos/dbus/permission_broker_client.h"
	#endif // defined(OS_CHROMEOS)

	namespace device {

	namespace {

	const char kHidrawSubsystem[] = "hidraw";
	const char kHIDID[] = "HID_ID";
	const char kHIDName[] = "HID_NAME";
	const char kHIDUnique[] = "HID_UNIQ";
	const char kSysfsReportDescriptorKey[] = "report_descriptor";

	} // namespace

	struct HidServiceLinux::ConnectParams {
	ConnectParams(scoped_refptr<HidDeviceInfo> device_info,
	const ConnectCallback& callback)
	: device_info(std::move(device_info)),
	callback(callback),
	task_runner(base::ThreadTaskRunnerHandle::Get()),
	blocking_task_runner(
	base::CreateSequencedTaskRunnerWithTraits(kBlockingTaskTraits)) {}
	~ConnectParams() {}

	scoped_refptr<HidDeviceInfo> device_info;
	ConnectCallback callback;
	scoped_refptr<base::SequencedTaskRunner> task_runner;
	scoped_refptr<base::SequencedTaskRunner> blocking_task_runner;
	base::ScopedFD fd;
	};

	class HidServiceLinux::BlockingTaskHelper : public UdevWatcher::Observer {
	public:
	BlockingTaskHelper(base::WeakPtr<HidServiceLinux> service)
	: service_(std::move(service)),
	task_runner_(base::ThreadTaskRunnerHandle::Get()) {
	DETACH_FROM_SEQUENCE(sequence_checker_);
	}

	~BlockingTaskHelper() override {
	DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
	}

	void Start() {
	base::AssertBlockingAllowed();
	DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);

	watcher_ = UdevWatcher::StartWatching(this);
	watcher_->EnumerateExistingDevices();
	task_runner_->PostTask(
	FROM_HERE,
	base::BindOnce(&HidServiceLinux::FirstEnumerationComplete, service_));
	}

	private:
	// UdevWatcher::Observer
	void OnDeviceAdded(ScopedUdevDevicePtr device) override {
	DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
	const char* device_path = udev_device_get_syspath(device.get());
	if (!device_path)
	return;
	HidPlatformDeviceId platform_device_id = device_path;

	const char* subsystem = udev_device_get_subsystem(device.get());
	if (!subsystem \|\| strcmp(subsystem, kHidrawSubsystem) != 0)
	return;

	const char* str_property = udev_device_get_devnode(device.get());
	if (!str_property)
	return;
	std::string device_node = str_property;

	udev_device* parent = udev_device_get_parent(device.get());
	if (!parent)
	return;

	const char* hid_id = udev_device_get_property_value(parent, kHIDID);
	if (!hid_id)
	return;

	std::vector<std::string> parts = base::SplitString(
	hid_id, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
	if (parts.size() != 3)
	return;

	uint32_t int_property = 0;
	if (!HexStringToUInt(base::StringPiece(parts[1]), &int_property) \|\|
	int_property > std::numeric_limits<uint16_t>::max()) {
	return;
	}
	uint16_t vendor_id = int_property;

	if (!HexStringToUInt(base::StringPiece(parts[2]), &int_property) \|\|
	int_property > std::numeric_limits<uint16_t>::max()) {
	return;
	}
	uint16_t product_id = int_property;

	std::string serial_number;
	str_property = udev_device_get_property_value(parent, kHIDUnique);
	if (str_property)
	serial_number = str_property;

	std::string product_name;
	str_property = udev_device_get_property_value(parent, kHIDName);
	if (str_property)
	product_name = str_property;

	const char* parent_sysfs_path = udev_device_get_syspath(parent);
	if (!parent_sysfs_path)
	return;
	base::FilePath report_descriptor_path =
	base::FilePath(parent_sysfs_path).Append(kSysfsReportDescriptorKey);
	std::string report_descriptor_str;
	if (!base::ReadFileToString(report_descriptor_path, &report_descriptor_str))
	return;

	scoped_refptr<HidDeviceInfo> device_info(new HidDeviceInfo(
	platform_device_id, vendor_id, product_id, product_name, serial_number,
	// TODO(reillyg): Detect Bluetooth. crbug.com/443335
	mojom::HidBusType::kHIDBusTypeUSB,
	std::vector<uint8_t>(report_descriptor_str.begin(),
	report_descriptor_str.end()),
	device_node));

	task_runner_->PostTask(
	FROM_HERE,
	base::BindOnce(&HidServiceLinux::AddDevice, service_, device_info));
	}

	void OnDeviceRemoved(ScopedUdevDevicePtr device) override {
	DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
	const char* device_path = udev_device_get_syspath(device.get());
	if (device_path) {
	task_runner_->PostTask(
	FROM_HERE, base::BindOnce(&HidServiceLinux::RemoveDevice, service_,
	std::string(device_path)));
	}
	}

	SEQUENCE_CHECKER(sequence_checker_);
	std::unique_ptr<UdevWatcher> watcher_;

	// This weak pointer is only valid when checked on this task runner.
	base::WeakPtr<HidServiceLinux> service_;
	scoped_refptr<base::SequencedTaskRunner> task_runner_;

	DISALLOW_COPY_AND_ASSIGN(BlockingTaskHelper);
	};

	HidServiceLinux::HidServiceLinux()
	: blocking_task_runner_(
	base::CreateSequencedTaskRunnerWithTraits(kBlockingTaskTraits)),
	weak_factory_(this) {
	helper_ = std::make_unique<BlockingTaskHelper>(weak_factory_.GetWeakPtr());
	blocking_task_runner_->PostTask(
	FROM_HERE, base::BindOnce(&BlockingTaskHelper::Start,
	base::Unretained(helper_.get())));
	}

	HidServiceLinux::~HidServiceLinux() {
	blocking_task_runner_->DeleteSoon(FROM_HERE, helper_.release());
	}

	base::WeakPtr<HidService> HidServiceLinux::GetWeakPtr() {
	return weak_factory_.GetWeakPtr();
	}

	void HidServiceLinux::Connect(const std::string& device_guid,
	const ConnectCallback& callback) {
	DCHECK(thread_checker_.CalledOnValidThread());

	const auto& map_entry = devices().find(device_guid);
	if (map_entry == devices().end()) {
	base::ThreadTaskRunnerHandle::Get()->PostTask(
	FROM_HERE, base::Bind(callback, nullptr));
	return;
	}
	scoped_refptr<HidDeviceInfo> device_info = map_entry->second;

	auto params = std::make_unique<ConnectParams>(device_info, callback);

	#if defined(OS_CHROMEOS)
	chromeos::PermissionBrokerClient* client =
	chromeos::DBusThreadManager::Get()->GetPermissionBrokerClient();
	DCHECK(client) << "Could not get permission broker client.";
	chromeos::PermissionBrokerClient::ErrorCallback error_callback =
	base::Bind(&HidServiceLinux::OnPathOpenError,
	params->device_info->device_node(), params->callback);
	client->OpenPath(
	device_info->device_node(),
	base::Bind(&HidServiceLinux::OnPathOpenComplete, base::Passed(&params)),
	error_callback);
	#else
	scoped_refptr<base::SequencedTaskRunner> blocking_task_runner =
	params->blocking_task_runner;
	blocking_task_runner->PostTask(
	FROM_HERE, base::BindOnce(&HidServiceLinux::OpenOnBlockingThread,
	std::move(params)));
	#endif // defined(OS_CHROMEOS)
	}

	#if defined(OS_CHROMEOS)

	// static
	void HidServiceLinux::OnPathOpenComplete(std::unique_ptr<ConnectParams> params,
	base::ScopedFD fd) {
	scoped_refptr<base::SequencedTaskRunner> blocking_task_runner =
	params->blocking_task_runner;
	params->fd = std::move(fd);
	blocking_task_runner->PostTask(
	FROM_HERE,
	base::BindOnce(&HidServiceLinux::FinishOpen, std::move(params)));
	}

	// static
	void HidServiceLinux::OnPathOpenError(const std::string& device_path,
	const ConnectCallback& callback,
	const std::string& error_name,
	const std::string& error_message) {
	HID_LOG(EVENT) << "Permission broker failed to open '" << device_path
	<< "': " << error_name << ": " << error_message;
	callback.Run(nullptr);
	}

	#else

	// static
	void HidServiceLinux::OpenOnBlockingThread(
	std::unique_ptr<ConnectParams> params) {
	base::AssertBlockingAllowed();
	scoped_refptr<base::SequencedTaskRunner> task_runner = params->task_runner;

	base::FilePath device_path(params->device_info->device_node());
	base::File device_file;
	int flags =
	base::File::FLAG_OPEN \| base::File::FLAG_READ \| base::File::FLAG_WRITE;
	device_file.Initialize(device_path, flags);
	if (!device_file.IsValid()) {
	base::File::Error file_error = device_file.error_details();

	if (file_error == base::File::FILE_ERROR_ACCESS_DENIED) {
	HID_LOG(EVENT)
	<< "Access denied opening device read-write, trying read-only.";
	flags = base::File::FLAG_OPEN \| base::File::FLAG_READ;
	device_file.Initialize(device_path, flags);
	}
	}
	if (!device_file.IsValid()) {
	HID_LOG(EVENT) << "Failed to open '" << params->device_info->device_node()
	<< "': "
	<< base::File::ErrorToString(device_file.error_details());
	task_runner->PostTask(FROM_HERE, base::BindOnce(params->callback, nullptr));
	return;
	}
	params->fd.reset(device_file.TakePlatformFile());
	FinishOpen(std::move(params));
	}

	#endif // defined(OS_CHROMEOS)

	// static
	void HidServiceLinux::FinishOpen(std::unique_ptr<ConnectParams> params) {
	base::AssertBlockingAllowed();
	scoped_refptr<base::SequencedTaskRunner> task_runner = params->task_runner;

	if (!base::SetNonBlocking(params->fd.get())) {
	HID_PLOG(ERROR) << "Failed to set the non-blocking flag on the device fd";
	task_runner->PostTask(FROM_HERE, base::BindOnce(params->callback, nullptr));
	return;
	}

	task_runner->PostTask(
	FROM_HERE,
	base::BindOnce(&HidServiceLinux::CreateConnection, std::move(params)));
	}

	// static
	void HidServiceLinux::CreateConnection(std::unique_ptr<ConnectParams> params) {
	DCHECK(params->fd.is_valid());
	params->callback.Run(base::MakeRefCounted<HidConnectionLinux>(
	std::move(params->device_info), std::move(params->fd),
	std::move(params->blocking_task_runner)));
	}

	} // namespace device