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 <libudev.h>
   6 #include <stdint.h>
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/bind.h"
  12 #include "base/logging.h"
  13 #include "base/platform_file.h"
  14 #include "base/stl_util.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/strings/string_piece.h"
  17 #include "base/strings/string_split.h"
  18 #include "device/hid/hid_connection_linux.h"
  19 #include "device/hid/hid_device_info.h"
  20 #include "device/hid/hid_service_linux.h"
  21 #include "device/hid/udev_common.h"
  22
  23 namespace device {
  24
  25 namespace {
  26
  27 const char kHIDSubSystem[] = "hid";
  28
  29 const char kHIDID[] = "HID_ID";
  30 const char kHIDName[] = "HID_NAME";
  31 const char kHIDUnique[] = "HID_UNIQ";
  32
  33 } // namespace
  34
  35 HidServiceLinux::HidServiceLinux() {
  36   DeviceMonitorLinux* monitor = DeviceMonitorLinux::GetInstance();
  37   monitor->AddObserver(this);
  38   monitor->Enumerate(
  39       base::Bind(&HidServiceLinux::OnDeviceAdded, base::Unretained(this)));
  40 }
  41
  42 scoped_refptr<HidConnection> HidServiceLinux::Connect(
  43     const HidDeviceId& device_id) {
  44   HidDeviceInfo device_info;
  45   if (!GetDeviceInfo(device_id, &device_info))
  46     return NULL;
  47
  48   ScopedUdevDevicePtr device =
  49       DeviceMonitorLinux::GetInstance()->GetDeviceFromPath(
  50           device_info.device_id);
  51   if (device)
  52     return new HidConnectionLinux(device_info, device.Pass());
  53   return NULL;
  54 }
  55
  56 HidServiceLinux::~HidServiceLinux() {
  57   if (DeviceMonitorLinux::HasInstance())
  58     DeviceMonitorLinux::GetInstance()->RemoveObserver(this);
  59 }
  60
  61 void HidServiceLinux::OnDeviceAdded(udev_device* device) {
  62   if (!device)
  63     return;
  64
  65   const char* device_path = udev_device_get_syspath(device);
  66   if (!device_path)
  67     return;
  68   const char* subsystem = udev_device_get_subsystem(device);
  69   if (!subsystem || strcmp(subsystem, kHIDSubSystem) != 0)
  70     return;
  71
  72   HidDeviceInfo device_info;
  73   device_info.device_id = device_path;
  74
  75   uint32_t int_property = 0;
  76   const char* str_property = NULL;
  77
  78   const char* hid_id = udev_device_get_property_value(device, kHIDID);
  79   if (!hid_id)
  80     return;
  81
  82   std::vector<std::string> parts;
  83   base::SplitString(hid_id, ':', &parts);
  84   if (parts.size() != 3) {
  85     return;
  86   }
  87
  88   if (HexStringToUInt(base::StringPiece(parts[1]), &int_property)) {
  89     device_info.vendor_id = int_property;
  90   }
  91
  92   if (HexStringToUInt(base::StringPiece(parts[2]), &int_property)) {
  93     device_info.product_id = int_property;
  94   }
  95
  96   str_property = udev_device_get_property_value(device, kHIDUnique);
  97   if (str_property != NULL)
  98     device_info.serial_number = str_property;
  99
 100   str_property = udev_device_get_property_value(device, kHIDName);
 101   if (str_property != NULL)
 102     device_info.product_name = str_property;
 103
 104   AddDevice(device_info);
 105 }
 106
 107 void HidServiceLinux::OnDeviceRemoved(udev_device* device) {
 108   const char* device_path = udev_device_get_syspath(device);;
 109   if (device_path)
 110     RemoveDevice(device_path);
 111 }
 112
 113 } // namespace dev