device/hid/hid_service_linux.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "device/hid/hid_service_linux.h"
   6
   7 #include <fcntl.h>
   8 #include <limits>
   9 #include <string>
  10
  11 #include "base/bind.h"
  12 #include "base/files/file.h"
  13 #include "base/files/file_path.h"
  14 #include "base/files/file_util.h"
  15 #include "base/location.h"
  16 #include "base/scoped_observer.h"
  17 #include "base/strings/string_number_conversions.h"
  18 #include "base/strings/string_split.h"
  19 #include "base/thread_task_runner_handle.h"
  20 #include "base/threading/thread_restrictions.h"
  21 #include "components/device_event_log/device_event_log.h"
  22 #include "device/hid/device_monitor_linux.h"
  23 #include "device/hid/hid_connection_linux.h"
  24 #include "device/hid/hid_device_info_linux.h"
  25 #include "device/udev_linux/scoped_udev.h"
  26 #include "net/base/net_util.h"
  27
  28 #if defined(OS_CHROMEOS)
  29 #include "base/sys_info.h"
  30 #include "chromeos/dbus/dbus_thread_manager.h"
  31 #include "chromeos/dbus/permission_broker_client.h"
  32 #endif  // defined(OS_CHROMEOS)
  33
  34 namespace device {
  35
  36 namespace {
  37
  38 const char kHidrawSubsystem[] = "hidraw";
  39 const char kHIDID[] = "HID_ID";
  40 const char kHIDName[] = "HID_NAME";
  41 const char kHIDUnique[] = "HID_UNIQ";
  42 const char kSysfsReportDescriptorKey[] = "report_descriptor";
  43
  44 }  // namespace
  45
  46 struct HidServiceLinux::ConnectParams {
  47   ConnectParams(scoped_refptr<HidDeviceInfoLinux> device_info,
  48                 const ConnectCallback& callback,
  49                 scoped_refptr<base::SingleThreadTaskRunner> task_runner,
  50                 scoped_refptr<base::SingleThreadTaskRunner> file_task_runner)
  51       : device_info(device_info),
  52         callback(callback),
  53         task_runner(task_runner),
  54         file_task_runner(file_task_runner) {}
  55   ~ConnectParams() {}
  56
  57   scoped_refptr<HidDeviceInfoLinux> device_info;
  58   ConnectCallback callback;
  59   scoped_refptr<base::SingleThreadTaskRunner> task_runner;
  60   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner;
  61   base::File device_file;
  62 };
  63
  64 class HidServiceLinux::FileThreadHelper
  65     : public DeviceMonitorLinux::Observer,
  66       public base::MessageLoop::DestructionObserver {
  67  public:
  68   FileThreadHelper(base::WeakPtr<HidServiceLinux> service,
  69                    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
  70       : observer_(this), service_(service), task_runner_(task_runner) {
  71     DeviceMonitorLinux* monitor = DeviceMonitorLinux::GetInstance();
  72     observer_.Add(monitor);
  73     monitor->Enumerate(
  74         base::Bind(&FileThreadHelper::OnDeviceAdded, base::Unretained(this)));
  75     task_runner->PostTask(
  76         FROM_HERE,
  77         base::Bind(&HidServiceLinux::FirstEnumerationComplete, service_));
  78   }
  79
  80   ~FileThreadHelper() override {
  81     DCHECK(thread_checker_.CalledOnValidThread());
  82   }
  83
  84  private:
  85   // DeviceMonitorLinux::Observer:
  86   void OnDeviceAdded(udev_device* device) override {
  87     DCHECK(thread_checker_.CalledOnValidThread());
  88     const char* device_path = udev_device_get_syspath(device);
  89     if (!device_path) {
  90       return;
  91     }
  92     HidDeviceId device_id = device_path;
  93
  94     const char* subsystem = udev_device_get_subsystem(device);
  95     if (!subsystem || strcmp(subsystem, kHidrawSubsystem) != 0) {
  96       return;
  97     }
  98
  99     const char* str_property = udev_device_get_devnode(device);
 100     if (!str_property) {
 101       return;
 102     }
 103     std::string device_node = str_property;
 104
 105     udev_device* parent = udev_device_get_parent(device);
 106     if (!parent) {
 107       return;
 108     }
 109
 110     const char* hid_id = udev_device_get_property_value(parent, kHIDID);
 111     if (!hid_id) {
 112       return;
 113     }
 114
 115     std::vector<std::string> parts = base::SplitString(
 116         hid_id, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
 117     if (parts.size() != 3) {
 118       return;
 119     }
 120
 121     uint32_t int_property = 0;
 122     if (!HexStringToUInt(base::StringPiece(parts[1]), &int_property) ||
 123         int_property > std::numeric_limits<uint16_t>::max()) {
 124       return;
 125     }
 126     uint16_t vendor_id = int_property;
 127
 128     if (!HexStringToUInt(base::StringPiece(parts[2]), &int_property) ||
 129         int_property > std::numeric_limits<uint16_t>::max()) {
 130       return;
 131     }
 132     uint16_t product_id = int_property;
 133
 134     std::string serial_number;
 135     str_property = udev_device_get_property_value(parent, kHIDUnique);
 136     if (str_property != NULL) {
 137       serial_number = str_property;
 138     }
 139
 140     std::string product_name;
 141     str_property = udev_device_get_property_value(parent, kHIDName);
 142     if (str_property != NULL) {
 143       product_name = str_property;
 144     }
 145
 146     const char* parent_sysfs_path = udev_device_get_syspath(parent);
 147     if (!parent_sysfs_path) {
 148       return;
 149     }
 150     base::FilePath report_descriptor_path =
 151         base::FilePath(parent_sysfs_path).Append(kSysfsReportDescriptorKey);
 152     std::string report_descriptor_str;
 153     if (!base::ReadFileToString(report_descriptor_path,
 154                                 &report_descriptor_str)) {
 155       return;
 156     }
 157
 158     scoped_refptr<HidDeviceInfo> device_info(new HidDeviceInfoLinux(
 159         device_id, device_node, vendor_id, product_id, product_name,
 160         serial_number,
 161         kHIDBusTypeUSB,  // TODO(reillyg): Detect Bluetooth. crbug.com/443335
 162         std::vector<uint8>(report_descriptor_str.begin(),
 163                            report_descriptor_str.end())));
 164
 165     task_runner_->PostTask(FROM_HERE, base::Bind(&HidServiceLinux::AddDevice,
 166                                                  service_, device_info));
 167   }
 168
 169   void OnDeviceRemoved(udev_device* device) override {
 170     DCHECK(thread_checker_.CalledOnValidThread());
 171     const char* device_path = udev_device_get_syspath(device);
 172     if (device_path) {
 173       task_runner_->PostTask(
 174           FROM_HERE, base::Bind(&HidServiceLinux::RemoveDevice, service_,
 175                                 std::string(device_path)));
 176     }
 177   }
 178
 179   // base::MessageLoop::DestructionObserver:
 180   void WillDestroyCurrentMessageLoop() override {
 181     DCHECK(thread_checker_.CalledOnValidThread());
 182     base::MessageLoop::current()->RemoveDestructionObserver(this);
 183     delete this;
 184   }
 185
 186   base::ThreadChecker thread_checker_;
 187   ScopedObserver<DeviceMonitorLinux, DeviceMonitorLinux::Observer> observer_;
 188
 189   // This weak pointer is only valid when checked on this task runner.
 190   base::WeakPtr<HidServiceLinux> service_;
 191   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 192 };
 193
 194 HidServiceLinux::HidServiceLinux(
 195     scoped_refptr<base::SingleThreadTaskRunner> file_task_runner)
 196     : file_task_runner_(file_task_runner), weak_factory_(this) {
 197   task_runner_ = base::ThreadTaskRunnerHandle::Get();
 198   // The device watcher is passed a weak pointer back to this service so that it
 199   // can be cleaned up after the service is destroyed however this weak pointer
 200   // must be constructed on the this thread where it will be checked.
 201   file_task_runner_->PostTask(
 202       FROM_HERE, base::Bind(&HidServiceLinux::StartHelper,
 203                             weak_factory_.GetWeakPtr(), task_runner_));
 204 }
 205
 206 // static
 207 void HidServiceLinux::StartHelper(
 208     base::WeakPtr<HidServiceLinux> weak_ptr,
 209     scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
 210   // Helper is a message loop destruction observer and will delete itself when
 211   // this thread's message loop is destroyed.
 212   new FileThreadHelper(weak_ptr, task_runner);
 213 }
 214
 215 void HidServiceLinux::Connect(const HidDeviceId& device_id,
 216                               const ConnectCallback& callback) {
 217   DCHECK(thread_checker_.CalledOnValidThread());
 218
 219   const auto& map_entry = devices().find(device_id);
 220   if (map_entry == devices().end()) {
 221     task_runner_->PostTask(FROM_HERE, base::Bind(callback, nullptr));
 222     return;
 223   }
 224   scoped_refptr<HidDeviceInfoLinux> device_info =
 225       static_cast<HidDeviceInfoLinux*>(map_entry->second.get());
 226
 227   scoped_ptr<ConnectParams> params(new ConnectParams(
 228       device_info, callback, task_runner_, file_task_runner_));
 229
 230 #if defined(OS_CHROMEOS)
 231   chromeos::PermissionBrokerClient* client =
 232       chromeos::DBusThreadManager::Get()->GetPermissionBrokerClient();
 233   DCHECK(client) << "Could not get permission broker client.";
 234   client->OpenPath(
 235       device_info->device_node(),
 236       base::Bind(&HidServiceLinux::OnPathOpened, base::Passed(&params)));
 237 #else
 238   file_task_runner_->PostTask(FROM_HERE,
 239                               base::Bind(&HidServiceLinux::OpenOnBlockingThread,
 240                                          base::Passed(&params)));
 241 #endif  // defined(OS_CHROMEOS)
 242 }
 243
 244 HidServiceLinux::~HidServiceLinux() {
 245   file_task_runner_->DeleteSoon(FROM_HERE, helper_.release());
 246 }
 247
 248 #if defined(OS_CHROMEOS)
 249
 250 // static
 251 void HidServiceLinux::OnPathOpened(scoped_ptr<ConnectParams> params,
 252                                    dbus::FileDescriptor fd) {
 253   scoped_refptr<base::SingleThreadTaskRunner> file_task_runner =
 254       params->file_task_runner;
 255   file_task_runner->PostTask(
 256       FROM_HERE, base::Bind(&HidServiceLinux::ValidateFdOnBlockingThread,
 257                             base::Passed(&params), base::Passed(&fd)));
 258 }
 259
 260 // static
 261 void HidServiceLinux::ValidateFdOnBlockingThread(
 262     scoped_ptr<ConnectParams> params,
 263     dbus::FileDescriptor fd) {
 264   base::ThreadRestrictions::AssertIOAllowed();
 265
 266   fd.CheckValidity();
 267   if (fd.is_valid()) {
 268     params->device_file = base::File(fd.TakeValue());
 269     FinishOpen(params.Pass());
 270   } else {
 271     HID_LOG(EVENT) << "Permission broker denied access to '"
 272                    << params->device_info->device_node() << "'.";
 273     params->task_runner->PostTask(FROM_HERE,
 274                                   base::Bind(params->callback, nullptr));
 275   }
 276 }
 277
 278 #else
 279
 280 // static
 281 void HidServiceLinux::OpenOnBlockingThread(scoped_ptr<ConnectParams> params) {
 282   base::ThreadRestrictions::AssertIOAllowed();
 283   scoped_refptr<base::SingleThreadTaskRunner> task_runner = params->task_runner;
 284
 285   base::FilePath device_path(params->device_info->device_node());
 286   base::File& device_file = params->device_file;
 287   int flags =
 288       base::File::FLAG_OPEN | base::File::FLAG_READ | base::File::FLAG_WRITE;
 289   device_file.Initialize(device_path, flags);
 290   if (!device_file.IsValid()) {
 291     base::File::Error file_error = device_file.error_details();
 292
 293     if (file_error == base::File::FILE_ERROR_ACCESS_DENIED) {
 294       HID_LOG(EVENT)
 295           << "Access denied opening device read-write, trying read-only.";
 296       flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
 297       device_file.Initialize(device_path, flags);
 298     }
 299   }
 300   if (!device_file.IsValid()) {
 301     HID_LOG(EVENT) << "Failed to open '" << params->device_info->device_node()
 302                    << "': "
 303                    << base::File::ErrorToString(device_file.error_details());
 304     task_runner->PostTask(FROM_HERE, base::Bind(params->callback, nullptr));
 305     return;
 306   }
 307
 308   FinishOpen(params.Pass());
 309 }
 310
 311 #endif  // defined(OS_CHROMEOS)
 312
 313 // static
 314 void HidServiceLinux::FinishOpen(scoped_ptr<ConnectParams> params) {
 315   base::ThreadRestrictions::AssertIOAllowed();
 316   scoped_refptr<base::SingleThreadTaskRunner> task_runner = params->task_runner;
 317
 318   int result = net::SetNonBlocking(params->device_file.GetPlatformFile());
 319   if (result == -1) {
 320     HID_PLOG(ERROR) << "Failed to set the non-blocking flag on the device fd";
 321     task_runner->PostTask(FROM_HERE, base::Bind(params->callback, nullptr));
 322     return;
 323   }
 324
 325   task_runner->PostTask(
 326       FROM_HERE,
 327       base::Bind(&HidServiceLinux::CreateConnection, base::Passed(&params)));
 328 }
 329
 330 // static
 331 void HidServiceLinux::CreateConnection(scoped_ptr<ConnectParams> params) {
 332   DCHECK(params->device_file.IsValid());
 333   params->callback.Run(make_scoped_refptr(
 334       new HidConnectionLinux(params->device_info, params->device_file.Pass(),
 335                              params->file_task_runner)));
 336 }
 337
 338 }  // namespace device