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| 1 // Copyright (c) 2011 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 "content/browser/gamepad/data_fetcher_linux.h" |
| 6 |
| 7 #include "base/debug/trace_event.h" |
| 8 #include "base/string_util.h" |
| 9 #include "base/utf_string_conversions.h" |
| 10 #include "content/common/gamepad_hardware_buffer.h" |
| 11 |
| 12 #include <dlfcn.h> |
| 13 #include <fcntl.h> |
| 14 #include <linux/joystick.h> |
| 15 #include <sys/stat.h> |
| 16 #include <sys/types.h> |
| 17 |
| 18 namespace content { |
| 19 |
| 20 using WebKit::WebGamepad; |
| 21 using WebKit::WebGamepads; |
| 22 |
| 23 // We rely on libudev to be available to notify us about device |
| 24 // insertions/removals, and to get device USB vendor/product information. We |
| 25 // try to dynamically load it here because it may not always be available. If |
| 26 // it isn't, we simply disable all gamepad functionality. This late-binding |
| 27 // apparatus is based on a simplified version of libjingle's |
| 28 // linuxdevicefetcher.cc. We declare the symbols we'll use up front, load the |
| 29 // .so and the symbols out of it at initialization time, and then retrieve |
| 30 // them by index using the LATE(...) macro for (fairly) tidy callsites. |
| 31 |
| 32 #define LIBUDEV_SYMBOLS_IN_USE \ |
| 33 X(udev_device_get_action) \ |
| 34 X(udev_device_get_devnode) \ |
| 35 X(udev_device_get_devtype) \ |
| 36 X(udev_device_get_parent_with_subsystem_devtype) \ |
| 37 X(udev_device_get_property_value) \ |
| 38 X(udev_device_get_subsystem) \ |
| 39 X(udev_device_get_sysattr_value) \ |
| 40 X(udev_device_new_from_syspath) \ |
| 41 X(udev_device_unref) \ |
| 42 X(udev_enumerate_add_match_subsystem) \ |
| 43 X(udev_enumerate_get_list_entry) \ |
| 44 X(udev_enumerate_new) \ |
| 45 X(udev_enumerate_scan_devices) \ |
| 46 X(udev_enumerate_unref) \ |
| 47 X(udev_list_entry_get_name) \ |
| 48 X(udev_list_entry_get_next) \ |
| 49 X(udev_monitor_enable_receiving) \ |
| 50 X(udev_monitor_filter_add_match_subsystem_devtype) \ |
| 51 X(udev_monitor_get_fd) \ |
| 52 X(udev_monitor_new_from_netlink) \ |
| 53 X(udev_monitor_receive_device) \ |
| 54 X(udev_monitor_unref) \ |
| 55 X(udev_new) \ |
| 56 X(udev_unref) |
| 57 |
| 58 enum LibUdevSymbolTable { |
| 59 #define X(sym) LibUdevSymbolTable_INDEX_##sym, |
| 60 LIBUDEV_SYMBOLS_IN_USE |
| 61 #undef X |
| 62 LibUdevSymbolTable_SIZE |
| 63 }; |
| 64 |
| 65 class LibUdevLateBound { |
| 66 public: |
| 67 static LibUdevLateBound* Load() { |
| 68 void* handle = dlopen("libudev.so.0", RTLD_NOW); |
| 69 if (!handle) |
| 70 return NULL; |
| 71 LibUdevLateBound* result = new LibUdevLateBound(handle); |
| 72 #define X(sym) result->symbols_[LibUdevSymbolTable_INDEX_##sym] = \ |
| 73 dlsym(result->handle_, #sym); \ |
| 74 if (!result->symbols_[LibUdevSymbolTable_INDEX_##sym]) { \ |
| 75 delete result; \ |
| 76 return NULL; \ |
| 77 } |
| 78 LIBUDEV_SYMBOLS_IN_USE |
| 79 #undef X |
| 80 return result; |
| 81 } |
| 82 |
| 83 void* GetByIndex(size_t index) { |
| 84 return symbols_[index]; |
| 85 } |
| 86 |
| 87 private: |
| 88 friend class scoped_ptr<LibUdevLateBound>; |
| 89 |
| 90 ~LibUdevLateBound() { |
| 91 dlclose(handle_); |
| 92 } |
| 93 |
| 94 LibUdevLateBound(void* handle) : handle_(handle) { |
| 95 } |
| 96 |
| 97 void* handle_; |
| 98 void* symbols_[LibUdevSymbolTable_SIZE]; |
| 99 |
| 100 DISALLOW_COPY_AND_ASSIGN(LibUdevLateBound); |
| 101 }; |
| 102 |
| 103 #define LATE(sym) (*reinterpret_cast<typeof(&sym)>(udevlib_->GetByIndex( \ |
| 104 LibUdevSymbolTable_INDEX_##sym))) |
| 105 |
| 106 GamepadDataFetcherLinux::GamepadDataFetcherLinux() |
| 107 : udevlib_(LibUdevLateBound::Load()) { |
| 108 if (!udevlib_.get()) |
| 109 return; |
| 110 |
| 111 for (size_t i = 0; i < arraysize(device_fds_); ++i) |
| 112 device_fds_[i] = -1; |
| 113 |
| 114 udev_ = LATE(udev_new)(); |
| 115 |
| 116 monitor_ = LATE(udev_monitor_new_from_netlink)(udev_, "udev"); |
| 117 LATE(udev_monitor_filter_add_match_subsystem_devtype)( |
| 118 monitor_, |
| 119 "input", |
| 120 NULL); |
| 121 LATE(udev_monitor_enable_receiving)(monitor_); |
| 122 monitor_fd_ = LATE(udev_monitor_get_fd)(monitor_); |
| 123 |
| 124 EnumerateDevices(); |
| 125 } |
| 126 |
| 127 bool GamepadDataFetcherLinux::IsGamepad( |
| 128 udev_device* dev, |
| 129 size_t& index, |
| 130 std::string& path) { |
| 131 if (!LATE(udev_device_get_property_value)(dev, "ID_INPUT_JOYSTICK")) |
| 132 return false; |
| 133 |
| 134 const char* node_path = LATE(udev_device_get_devnode)(dev); |
| 135 if (!node_path) |
| 136 return false; |
| 137 |
| 138 static const char kJoystickRoot[] = "/dev/input/js"; |
| 139 bool is = strncmp(kJoystickRoot, node_path, sizeof(kJoystickRoot) - 1) == 0; |
| 140 if (is) { |
| 141 index = node_path[sizeof(kJoystickRoot) - 1] - '0'; |
| 142 if (index < 0 || index >= WebGamepads::itemsLengthCap) |
| 143 return false; |
| 144 path = std::string(node_path); |
| 145 } |
| 146 return is; |
| 147 } |
| 148 |
| 149 // Used during enumeration, and monitor notifications. |
| 150 void GamepadDataFetcherLinux::RefreshDevice(udev_device* dev) { |
| 151 size_t index; |
| 152 std::string node_path; |
| 153 if (IsGamepad(dev, index, node_path)) { |
| 154 int& device_fd = device_fds_[index]; |
| 155 WebGamepad& pad = data_.items[index]; |
| 156 GamepadStandardMappingFunction& mapper = mappers_[index]; |
| 157 |
| 158 // The device pointed to by dev contains information about the input |
| 159 // device. In order to get the information about the USB device, get the |
| 160 // parent device with the subsystem/devtype pair of "usb"/"usb_device". |
| 161 // This function walks up the tree several levels. |
| 162 dev = LATE(udev_device_get_parent_with_subsystem_devtype)( |
| 163 dev, |
| 164 "usb", |
| 165 "usb_device"); |
| 166 if (!dev) { |
| 167 // Unable to get device information, don't use this device. |
| 168 device_fd = -1; |
| 169 pad.connected = false; |
| 170 return; |
| 171 } |
| 172 |
| 173 device_fd = open(node_path.c_str(), O_RDONLY | O_NONBLOCK); |
| 174 if (device_fd < 0) { |
| 175 // Unable to open device, don't use. |
| 176 pad.connected = false; |
| 177 return; |
| 178 } |
| 179 |
| 180 const char* vendor_id = |
| 181 LATE(udev_device_get_sysattr_value)(dev, "idVendor"); |
| 182 const char* product_id = |
| 183 LATE(udev_device_get_sysattr_value)(dev, "idProduct"); |
| 184 mapper = GetGamepadStandardMappingFunction(vendor_id, product_id); |
| 185 |
| 186 const char* manufacturer = |
| 187 LATE(udev_device_get_sysattr_value)(dev, "manufacturer"); |
| 188 const char* product = LATE(udev_device_get_sysattr_value)(dev, "product"); |
| 189 |
| 190 // Driver returns utf-8 strings here, so combine in utf-8 and then convert |
| 191 // to WebUChar to build the id string. |
| 192 char tmp[WebGamepad::idLengthCap]; |
| 193 if (mapper) { |
| 194 base::snprintf(tmp, |
| 195 sizeof(tmp), |
| 196 "%s %s (STANDARD GAMEPAD)", |
| 197 manufacturer, |
| 198 product); |
| 199 } else { |
| 200 base::snprintf(tmp, |
| 201 sizeof(tmp), |
| 202 "%s %s (Vendor: %s Product: %s)", |
| 203 manufacturer, |
| 204 product, |
| 205 vendor_id, |
| 206 product_id); |
| 207 } |
| 208 string16 tmp16 = UTF8ToUTF16(tmp); |
| 209 memset(pad.id, 0, sizeof(pad.id)); |
| 210 tmp16.copy(pad.id, sizeof(pad.id) - 1); |
| 211 |
| 212 pad.connected = true; |
| 213 } |
| 214 } |
| 215 |
| 216 void GamepadDataFetcherLinux::EnumerateDevices() { |
| 217 udev_enumerate* enumerate = LATE(udev_enumerate_new)(udev_); |
| 218 LATE(udev_enumerate_add_match_subsystem)(enumerate, "input"); |
| 219 LATE(udev_enumerate_scan_devices)(enumerate); |
| 220 |
| 221 udev_list_entry* devices = LATE(udev_enumerate_get_list_entry)(enumerate); |
| 222 for (udev_list_entry* dev_list_entry = devices; |
| 223 dev_list_entry != NULL; |
| 224 dev_list_entry = LATE(udev_list_entry_get_next)(dev_list_entry)) { |
| 225 // Get the filename of the /sys entry for the device and create a |
| 226 // udev_device object (dev) representing it |
| 227 const char* path = LATE(udev_list_entry_get_name)(dev_list_entry); |
| 228 udev_device* dev = LATE(udev_device_new_from_syspath)(udev_, path); |
| 229 RefreshDevice(dev); |
| 230 LATE(udev_device_unref)(dev); |
| 231 } |
| 232 // Free the enumerator object |
| 233 LATE(udev_enumerate_unref)(enumerate); |
| 234 } |
| 235 |
| 236 GamepadDataFetcherLinux::~GamepadDataFetcherLinux() { |
| 237 LATE(udev_unref)(udev_); |
| 238 } |
| 239 |
| 240 void GamepadDataFetcherLinux::CheckForAddRemoveEvents() { |
| 241 // Poll for udev events. Events occur when devices attached to the system |
| 242 // are added, removed, or change state. udev_monitor_receive_device() will |
| 243 // return a device object representing the device which changed and what |
| 244 // type of change occured. |
| 245 // |
| 246 // The select() system call is used to ensure that the call to |
| 247 // udev_monitor_receive_device() will not block. |
| 248 fd_set fds; |
| 249 struct timeval tv; |
| 250 FD_ZERO(&fds); |
| 251 FD_SET(monitor_fd_, &fds); |
| 252 tv.tv_sec = 0; |
| 253 tv.tv_usec = 0; |
| 254 |
| 255 // Check if our file descriptor has received data. |
| 256 if (select(monitor_fd_ + 1, &fds, NULL, NULL, &tv) > 0 |
| 257 && FD_ISSET(monitor_fd_, &fds)) { |
| 258 // Make the call to receive the device. |
| 259 // select() ensured that this will not block. |
| 260 udev_device* dev = LATE(udev_monitor_receive_device)(monitor_); |
| 261 RefreshDevice(dev); |
| 262 LATE(udev_device_unref)(dev); |
| 263 } |
| 264 } |
| 265 |
| 266 void GamepadDataFetcherLinux::ReadDeviceData(size_t index) { |
| 267 int& fd = device_fds_[index]; |
| 268 WebGamepad& pad = data_.items[index]; |
| 269 DCHECK(fd >= 0); |
| 270 |
| 271 js_event event; |
| 272 while (read(fd, &event, sizeof(struct js_event)) > 0) { |
| 273 size_t item = event.number; |
| 274 if (event.type & JS_EVENT_AXIS) { |
| 275 if (item >= WebGamepad::axesLengthCap) |
| 276 continue; |
| 277 pad.axes[item] = event.value / 32767.f; |
| 278 if (item >= pad.axesLength) |
| 279 pad.axesLength = item + 1; |
| 280 } else if (event.type & JS_EVENT_BUTTON) { |
| 281 if (item >= WebGamepad::buttonsLengthCap) |
| 282 continue; |
| 283 pad.buttons[item] = event.value ? 1.0 : 0.0; |
| 284 if (item >= pad.buttonsLength) |
| 285 pad.buttonsLength = item + 1; |
| 286 } |
| 287 pad.timestamp = event.time; |
| 288 } |
| 289 } |
| 290 |
| 291 void GamepadDataFetcherLinux::GetGamepadData(WebGamepads* pads, bool) { |
| 292 TRACE_EVENT0("GAMEPAD", "GetGamepadData"); |
| 293 |
| 294 // If we were unable to load libudev then we are disabled, simply return no |
| 295 // data. |
| 296 if (!udevlib_.get()) { |
| 297 pads->length = 0; |
| 298 return; |
| 299 } |
| 300 |
| 301 data_.length = WebGamepads::itemsLengthCap; |
| 302 |
| 303 CheckForAddRemoveEvents(); |
| 304 |
| 305 // Update our internal state. |
| 306 for (size_t i = 0; i < WebGamepads::itemsLengthCap; ++i) { |
| 307 if (device_fds_[i] >= 0) { |
| 308 ReadDeviceData(i); |
| 309 } |
| 310 } |
| 311 |
| 312 // Copy to the current state to the output buffer, using the mapping |
| 313 // function, if there is one available. |
| 314 pads->length = data_.length; |
| 315 for (size_t i = 0; i < WebGamepads::itemsLengthCap; ++i) { |
| 316 if (mappers_[i]) |
| 317 mappers_[i](data_.items[i], &pads->items[i]); |
| 318 else |
| 319 pads->items[i] = data_.items[i]; |
| 320 } |
| 321 } |
| 322 |
| 323 } // namespace content |
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