windows.c

   1 /*
   2  * This file is part of the libserialport project.
   3  *
   4  * Copyright (C) 2013-2014 Martin Ling <martin-libserialport@earth.li>
   5  * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Lesser General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "libserialport.h"
  22 #include "libserialport_internal.h"
  23
  24 /* USB path is a string of at most 8 decimal numbers < 128 separated by dots. */
  25 #define MAX_USB_PATH ((8 * 3) + (7 * 1) + 1)
  26
  27 static void enumerate_hub(struct sp_port *port, const char *hub_name,
  28                           const char *parent_path);
  29
  30 static char *wc_to_utf8(PWCHAR wc_buffer, ULONG size)
  31 {
  32         WCHAR wc_str[(size / sizeof(WCHAR)) + 1];
  33         char *utf8_str;
  34
  35         /* Zero-terminate the wide char string. */
  36         memcpy(wc_str, wc_buffer, size);
  37         wc_str[sizeof(wc_str) - 1] = 0;
  38
  39         /* Compute the size of the UTF-8 converted string. */
  40         if (!(size = WideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, wc_str, -1,
  41                                          NULL, 0, NULL, NULL)))
  42                 return NULL;
  43
  44         /* Allocate UTF-8 output buffer. */
  45         if (!(utf8_str = malloc(size)))
  46                 return NULL;
  47
  48         /* Actually converted to UTF-8. */
  49         if (!WideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, wc_str, -1,
  50                                  utf8_str, size, NULL, NULL)) {
  51                 free(utf8_str);
  52                 return NULL;
  53         }
  54
  55         return utf8_str;
  56 }
  57
  58 static char *get_root_hub_name(HANDLE host_controller)
  59 {
  60         USB_ROOT_HUB_NAME root_hub_name;
  61         PUSB_ROOT_HUB_NAME root_hub_name_wc;
  62         char *root_hub_name_utf8;
  63         ULONG size = 0;
  64
  65         /* Compute the size of the root hub name string. */
  66         if (!DeviceIoControl(host_controller, IOCTL_USB_GET_ROOT_HUB_NAME, 0, 0,
  67                              &root_hub_name, sizeof(root_hub_name), &size, NULL))
  68                 return NULL;
  69
  70         /* Allocate wide char root hub name string. */
  71         size = root_hub_name.ActualLength;
  72         if (!(root_hub_name_wc = malloc(size)))
  73                 return NULL;
  74
  75         /* Actually get the root hub name string. */
  76         if (!DeviceIoControl(host_controller, IOCTL_USB_GET_ROOT_HUB_NAME,
  77                              NULL, 0, root_hub_name_wc, size, &size, NULL)) {
  78                 free(root_hub_name_wc);
  79                 return NULL;
  80         }
  81
  82         /* Convert the root hub name string to UTF-8. */
  83         root_hub_name_utf8 = wc_to_utf8(root_hub_name_wc->RootHubName, size);
  84         free(root_hub_name_wc);
  85         return root_hub_name_utf8;
  86 }
  87
  88 static char *get_external_hub_name(HANDLE hub, ULONG connection_index)
  89 {
  90         USB_NODE_CONNECTION_NAME ext_hub_name;
  91         PUSB_NODE_CONNECTION_NAME ext_hub_name_wc;
  92         char *ext_hub_name_utf8;
  93         ULONG size;
  94
  95         /* Compute the size of the external hub name string. */
  96         ext_hub_name.ConnectionIndex = connection_index;
  97         if (!DeviceIoControl(hub, IOCTL_USB_GET_NODE_CONNECTION_NAME,
  98                              &ext_hub_name, sizeof(ext_hub_name),
  99                              &ext_hub_name, sizeof(ext_hub_name), &size, NULL))
 100                 return NULL;
 101
 102         /* Allocate wide char external hub name string. */
 103         size = ext_hub_name.ActualLength;
 104         if (size <= sizeof(ext_hub_name)
 105             || !(ext_hub_name_wc = malloc(size)))
 106                 return NULL;
 107
 108         /* Get the name of the external hub attached to the specified port. */
 109         ext_hub_name_wc->ConnectionIndex = connection_index;
 110         if (!DeviceIoControl(hub, IOCTL_USB_GET_NODE_CONNECTION_NAME,
 111                              ext_hub_name_wc, size,
 112                              ext_hub_name_wc, size, &size, NULL)) {
 113                 free(ext_hub_name_wc);
 114                 return NULL;
 115         }
 116
 117         /* Convert the external hub name string to UTF-8. */
 118         ext_hub_name_utf8 = wc_to_utf8(ext_hub_name_wc->NodeName, size);
 119         free(ext_hub_name_wc);
 120         return ext_hub_name_utf8;
 121 }
 122
 123 static char *get_string_descriptor(HANDLE hub_device, ULONG connection_index,
 124                                    UCHAR descriptor_index)
 125 {
 126         char desc_req_buf[sizeof(USB_DESCRIPTOR_REQUEST) +
 127                           MAXIMUM_USB_STRING_LENGTH] = { 0 };
 128         PUSB_DESCRIPTOR_REQUEST desc_req = (void *)desc_req_buf;
 129         PUSB_STRING_DESCRIPTOR desc = (void *)(desc_req + 1);
 130         ULONG size = sizeof(desc_req_buf);
 131
 132         desc_req->ConnectionIndex = connection_index;
 133         desc_req->SetupPacket.wValue = (USB_STRING_DESCRIPTOR_TYPE << 8)
 134                                        | descriptor_index;
 135         desc_req->SetupPacket.wIndex = 0;
 136         desc_req->SetupPacket.wLength = size - sizeof(*desc_req);
 137
 138         if (!DeviceIoControl(hub_device,
 139                              IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION,
 140                              desc_req, size, desc_req, size, &size, NULL)
 141             || size < 2
 142             || desc->bDescriptorType != USB_STRING_DESCRIPTOR_TYPE
 143             || desc->bLength != size - sizeof(*desc_req)
 144             || desc->bLength % 2)
 145                 return NULL;
 146
 147         return wc_to_utf8(desc->bString, desc->bLength);
 148 }
 149
 150 static void enumerate_hub_ports(struct sp_port *port, HANDLE hub_device,
 151                                 ULONG nb_ports, const char *parent_path)
 152 {
 153         char path[MAX_USB_PATH];
 154         ULONG index = 0;
 155
 156         for (index = 1; index <= nb_ports; index++) {
 157                 PUSB_NODE_CONNECTION_INFORMATION_EX connection_info_ex;
 158                 ULONG size = sizeof(*connection_info_ex) + (30 * sizeof(USB_PIPE_INFO));
 159
 160                 if (!(connection_info_ex = malloc(size)))
 161                         break;
 162
 163                 connection_info_ex->ConnectionIndex = index;
 164                 if (!DeviceIoControl(hub_device,
 165                                      IOCTL_USB_GET_NODE_CONNECTION_INFORMATION_EX,
 166                                      connection_info_ex, size,
 167                                      connection_info_ex, size, &size, NULL)) {
 168                         /*
 169                          * Try to get CONNECTION_INFORMATION if
 170                          * CONNECTION_INFORMATION_EX did not work.
 171                          */
 172                         PUSB_NODE_CONNECTION_INFORMATION connection_info;
 173
 174                         size = sizeof(*connection_info) + (30 * sizeof(USB_PIPE_INFO));
 175                         if (!(connection_info = malloc(size))) {
 176                                 free(connection_info_ex);
 177                                 continue;
 178                         }
 179                         connection_info->ConnectionIndex = index;
 180                         if (!DeviceIoControl(hub_device,
 181                                              IOCTL_USB_GET_NODE_CONNECTION_INFORMATION,
 182                                              connection_info, size,
 183                                              connection_info, size, &size, NULL)) {
 184                                 free(connection_info);
 185                                 free(connection_info_ex);
 186                                 continue;
 187                         }
 188
 189                         connection_info_ex->ConnectionIndex = connection_info->ConnectionIndex;
 190                         connection_info_ex->DeviceDescriptor = connection_info->DeviceDescriptor;
 191                         connection_info_ex->DeviceIsHub = connection_info->DeviceIsHub;
 192                         connection_info_ex->DeviceAddress = connection_info->DeviceAddress;
 193                         free(connection_info);
 194                 }
 195
 196                 if (connection_info_ex->DeviceIsHub) {
 197                         /* Recursively enumerate external hub. */
 198                         PCHAR ext_hub_name;
 199                         if ((ext_hub_name = get_external_hub_name(hub_device, index))) {
 200                                 snprintf(path, sizeof(path), "%s%ld.",
 201                                          parent_path, connection_info_ex->ConnectionIndex);
 202                                 enumerate_hub(port, ext_hub_name, path);
 203                         }
 204                         free(connection_info_ex);
 205                 } else {
 206                         snprintf(path, sizeof(path), "%s%ld",
 207                                  parent_path, connection_info_ex->ConnectionIndex);
 208
 209                         /* Check if this device is the one we search for. */
 210                         if (strcmp(path, port->usb_path)) {
 211                                 free(connection_info_ex);
 212                                 continue;
 213                         }
 214
 215                         /* Finally grab detailed information regarding the device. */
 216                         port->usb_address = connection_info_ex->DeviceAddress + 1;
 217                         port->usb_vid = connection_info_ex->DeviceDescriptor.idVendor;
 218                         port->usb_pid = connection_info_ex->DeviceDescriptor.idProduct;
 219
 220                         if (connection_info_ex->DeviceDescriptor.iManufacturer)
 221                                 port->usb_manufacturer = get_string_descriptor(hub_device,index,
 222                                            connection_info_ex->DeviceDescriptor.iManufacturer);
 223                         if (connection_info_ex->DeviceDescriptor.iProduct)
 224                                 port->usb_product = get_string_descriptor(hub_device, index,
 225                                            connection_info_ex->DeviceDescriptor.iProduct);
 226                         if (connection_info_ex->DeviceDescriptor.iSerialNumber)
 227                                 port->usb_serial = get_string_descriptor(hub_device, index,
 228                                            connection_info_ex->DeviceDescriptor.iSerialNumber);
 229
 230                         free(connection_info_ex);
 231                         break;
 232                 }
 233         }
 234 }
 235
 236 static void enumerate_hub(struct sp_port *port, const char *hub_name,
 237                           const char *parent_path)
 238 {
 239         USB_NODE_INFORMATION hub_info;
 240         HANDLE hub_device;
 241         ULONG size = sizeof(hub_info);
 242         char *device_name;
 243
 244         /* Open the hub with its full name. */
 245         if (!(device_name = malloc(strlen("\\\\.\\") + strlen(hub_name) + 1)))
 246                 return;
 247         strcpy(device_name, "\\\\.\\");
 248         strcat(device_name, hub_name);
 249         hub_device = CreateFile(device_name, GENERIC_WRITE, FILE_SHARE_WRITE,
 250                                 NULL, OPEN_EXISTING, 0, NULL);
 251         free(device_name);
 252         if (hub_device == INVALID_HANDLE_VALUE)
 253                 return;
 254
 255         /* Get the number of ports of the hub. */
 256         if (DeviceIoControl(hub_device, IOCTL_USB_GET_NODE_INFORMATION,
 257                             &hub_info, size, &hub_info, size, &size, NULL))
 258                 /* Enumerate the ports of the hub. */
 259                 enumerate_hub_ports(port, hub_device,
 260                    hub_info.u.HubInformation.HubDescriptor.bNumberOfPorts, parent_path);
 261
 262         CloseHandle(hub_device);
 263 }
 264
 265 static void enumerate_host_controller(struct sp_port *port,
 266                                       HANDLE host_controller_device)
 267 {
 268         char *root_hub_name;
 269
 270         if ((root_hub_name = get_root_hub_name(host_controller_device))) {
 271                 enumerate_hub(port, root_hub_name, "");
 272                 free(root_hub_name);
 273         }
 274 }
 275
 276 static void get_usb_details(struct sp_port *port, DEVINST dev_inst_match)
 277 {
 278         HDEVINFO device_info;
 279         SP_DEVINFO_DATA device_info_data;
 280         ULONG i, size = 0;
 281
 282         device_info = SetupDiGetClassDevs(&GUID_CLASS_USB_HOST_CONTROLLER, NULL, NULL,
 283                                           DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
 284         device_info_data.cbSize = sizeof(device_info_data);
 285
 286         for (i = 0; SetupDiEnumDeviceInfo(device_info, i, &device_info_data); i++) {
 287                 SP_DEVICE_INTERFACE_DATA device_interface_data;
 288                 PSP_DEVICE_INTERFACE_DETAIL_DATA device_detail_data;
 289                 DEVINST dev_inst = dev_inst_match;
 290                 HANDLE host_controller_device;
 291
 292                 device_interface_data.cbSize = sizeof(device_interface_data);
 293                 if (!SetupDiEnumDeviceInterfaces(device_info, 0,
 294                                                  &GUID_CLASS_USB_HOST_CONTROLLER,
 295                                                  i, &device_interface_data))
 296                         continue;
 297
 298                 if (!SetupDiGetDeviceInterfaceDetail(device_info,&device_interface_data,
 299                                                      NULL, 0, &size, NULL)
 300                     && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
 301                         continue;
 302
 303                 if (!(device_detail_data = malloc(size)))
 304                         continue;
 305                 device_detail_data->cbSize = sizeof(*device_detail_data);
 306                 if (!SetupDiGetDeviceInterfaceDetail(device_info,&device_interface_data,
 307                                                      device_detail_data, size, &size,
 308                                                      NULL)) {
 309                         free(device_detail_data);
 310                         continue;
 311                 }
 312
 313                 while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS
 314                        && dev_inst != device_info_data.DevInst) { }
 315                 if (dev_inst != device_info_data.DevInst) {
 316                         free(device_detail_data);
 317                         continue;
 318                 }
 319
 320                 port->usb_bus = i + 1;
 321
 322                 host_controller_device = CreateFile(device_detail_data->DevicePath,
 323                                                     GENERIC_WRITE, FILE_SHARE_WRITE,
 324                                                     NULL, OPEN_EXISTING, 0, NULL);
 325                 if (host_controller_device != INVALID_HANDLE_VALUE) {
 326                         enumerate_host_controller(port, host_controller_device);
 327                         CloseHandle(host_controller_device);
 328                 }
 329                 free(device_detail_data);
 330         }
 331
 332         SetupDiDestroyDeviceInfoList(device_info);
 333         return;
 334 }
 335
 336 SP_PRIV enum sp_return get_port_details(struct sp_port *port)
 337 {
 338         /*
 339          * Description limited to 127 char, anything longer
 340          * would not be user friendly anyway.
 341          */
 342         char description[128];
 343         SP_DEVINFO_DATA device_info_data = { .cbSize = sizeof(device_info_data) };
 344         HDEVINFO device_info;
 345         int i;
 346
 347         device_info = SetupDiGetClassDevs(NULL, 0, 0,
 348                                           DIGCF_PRESENT | DIGCF_ALLCLASSES);
 349         if (device_info == INVALID_HANDLE_VALUE)
 350                 RETURN_FAIL("SetupDiGetClassDevs() failed");
 351
 352         for (i = 0; SetupDiEnumDeviceInfo(device_info, i, &device_info_data); i++) {
 353                 HKEY device_key;
 354                 DEVINST dev_inst;
 355                 char value[8], class[16];
 356                 DWORD size, type;
 357                 CONFIGRET cr;
 358
 359                 /* Check if this is the device we are looking for. */
 360                 device_key = SetupDiOpenDevRegKey(device_info, &device_info_data,
 361                                                   DICS_FLAG_GLOBAL, 0,
 362                                                   DIREG_DEV, KEY_QUERY_VALUE);
 363                 if (device_key == INVALID_HANDLE_VALUE)
 364                         continue;
 365                 size = sizeof(value);
 366                 if (RegQueryValueExA(device_key, "PortName", NULL, &type, (LPBYTE)value,
 367                                      &size) != ERROR_SUCCESS || type != REG_SZ) {
 368                         RegCloseKey(device_key);
 369                         continue;
 370                 }
 371                 RegCloseKey(device_key);
 372                 value[sizeof(value)-1] = 0;
 373                 if (strcmp(value, port->name))
 374                         continue;
 375
 376                 /* Check port transport type. */
 377                 dev_inst = device_info_data.DevInst;
 378                 size = sizeof(class);
 379                 cr = CR_FAILURE;
 380                 while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS &&
 381                        (cr = CM_Get_DevNode_Registry_PropertyA(dev_inst,
 382                                  CM_DRP_CLASS, 0, class, &size, 0)) != CR_SUCCESS) { }
 383                 if (cr == CR_SUCCESS) {
 384                         if (!strcmp(class, "USB"))
 385                                 port->transport = SP_TRANSPORT_USB;
 386                 }
 387
 388                 /* Get port description (friendly name). */
 389                 dev_inst = device_info_data.DevInst;
 390                 size = sizeof(description);
 391                 while ((cr = CM_Get_DevNode_Registry_PropertyA(dev_inst,
 392                           CM_DRP_FRIENDLYNAME, 0, description, &size, 0)) != CR_SUCCESS
 393                        && CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS) { }
 394                 if (cr == CR_SUCCESS)
 395                         port->description = strdup(description);
 396
 397                 /* Get more informations for USB connected ports. */
 398                 if (port->transport == SP_TRANSPORT_USB) {
 399                         char usb_path[MAX_USB_PATH] = "", tmp[MAX_USB_PATH];
 400                         char device_id[MAX_DEVICE_ID_LEN];
 401
 402                         /* Recurse over parents to build the USB device path. */
 403                         dev_inst = device_info_data.DevInst;
 404                         do {
 405                                 /* Verify that this layer of the tree is USB related. */
 406                                 if (CM_Get_Device_IDA(dev_inst, device_id,
 407                                                       sizeof(device_id), 0) != CR_SUCCESS
 408                                     || strncmp(device_id, "USB\\", 4))
 409                                         continue;
 410
 411                                 /* Discard one layer for composite devices. */
 412                                 char compat_ids[512], *p = compat_ids;
 413                                 size = sizeof(compat_ids);
 414                                 if (CM_Get_DevNode_Registry_PropertyA(dev_inst,
 415                                                                       CM_DRP_COMPATIBLEIDS, 0,
 416                                                                       &compat_ids,
 417                                                                       &size, 0) == CR_SUCCESS) {
 418                                         while (*p) {
 419                                                 if (!strncmp(p, "USB\\COMPOSITE", 13))
 420                                                         break;
 421                                                 p += strlen(p) + 1;
 422                                         }
 423                                         if (*p)
 424                                                 continue;
 425                                 }
 426
 427                                 /* Stop the recursion when reaching the USB root. */
 428                                 if (!strncmp(device_id, "USB\\ROOT", 8))
 429                                         break;
 430
 431                                 /* Prepend the address of current USB layer to the USB path. */
 432                                 DWORD address;
 433                                 size = sizeof(address);
 434                                 if (CM_Get_DevNode_Registry_PropertyA(dev_inst, CM_DRP_ADDRESS,
 435                                                         0, &address, &size, 0) == CR_SUCCESS) {
 436                                         strcpy(tmp, usb_path);
 437                                         snprintf(usb_path, sizeof(usb_path), "%d%s%s",
 438                                                  (int)address, *tmp ? "." : "", tmp);
 439                                 }
 440                         } while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS);
 441
 442                         port->usb_path = strdup(usb_path);
 443
 444                         /* Wake up the USB device to be able to read string descriptor. */
 445                         char *escaped_port_name;
 446                         HANDLE handle;
 447                         if (!(escaped_port_name = malloc(strlen(port->name) + 5)))
 448                                 RETURN_ERROR(SP_ERR_MEM, "Escaped port name malloc failed");
 449                         sprintf(escaped_port_name, "\\\\.\\%s", port->name);
 450                         handle = CreateFile(escaped_port_name, GENERIC_READ, 0, 0,
 451                                             OPEN_EXISTING,
 452                                             FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, 0);
 453                         free(escaped_port_name);
 454                         CloseHandle(handle);
 455
 456                         /* Retrieve USB device details from the device descriptor. */
 457                         get_usb_details(port, device_info_data.DevInst);
 458                 }
 459                 break;
 460         }
 461
 462         SetupDiDestroyDeviceInfoList(device_info);
 463
 464         RETURN_OK();
 465 }
 466
 467 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 468 {
 469         HKEY key;
 470         TCHAR *value, *data;
 471         DWORD max_value_len, max_data_size, max_data_len;
 472         DWORD value_len, data_size, data_len;
 473         DWORD type, index = 0;
 474         char *name;
 475         int name_len;
 476         int ret = SP_OK;
 477
 478         DEBUG("Opening registry key");
 479         if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
 480                         0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS) {
 481                 SET_FAIL(ret, "RegOpenKeyEx() failed");
 482                 goto out_done;
 483         }
 484         DEBUG("Querying registry key value and data sizes");
 485         if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 486                                 &max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS) {
 487                 SET_FAIL(ret, "RegQueryInfoKey() failed");
 488                 goto out_close;
 489         }
 490         max_data_len = max_data_size / sizeof(TCHAR);
 491         if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR)))) {
 492                 SET_ERROR(ret, SP_ERR_MEM, "Registry value malloc failed");
 493                 goto out_close;
 494         }
 495         if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR)))) {
 496                 SET_ERROR(ret, SP_ERR_MEM, "Registry data malloc failed");
 497                 goto out_free_value;
 498         }
 499         DEBUG("Iterating over values");
 500         while (
 501                 value_len = max_value_len + 1,
 502                 data_size = max_data_size,
 503                 RegEnumValue(key, index, value, &value_len,
 504                         NULL, &type, (LPBYTE)data, &data_size) == ERROR_SUCCESS)
 505         {
 506                 if (type == REG_SZ) {
 507                         data_len = data_size / sizeof(TCHAR);
 508                         data[data_len] = '\0';
 509 #ifdef UNICODE
 510                         name_len = WideCharToMultiByte(CP_ACP, 0, data, -1, NULL, 0, NULL, NULL);
 511 #else
 512                         name_len = data_len + 1;
 513 #endif
 514                         if (!(name = malloc(name_len))) {
 515                                 SET_ERROR(ret, SP_ERR_MEM, "Registry port name malloc failed");
 516                                 goto out;
 517                         }
 518 #ifdef UNICODE
 519                         WideCharToMultiByte(CP_ACP, 0, data, -1, name, name_len, NULL, NULL);
 520 #else
 521                         strcpy(name, data);
 522 #endif
 523                         DEBUG_FMT("Found port %s", name);
 524                         if (!(*list = list_append(*list, name))) {
 525                                 SET_ERROR(ret, SP_ERR_MEM, "List append failed");
 526                                 free(name);
 527                                 goto out;
 528                         }
 529                         free(name);
 530                 }
 531                 index++;
 532         }
 533 out:
 534         free(data);
 535 out_free_value:
 536         free(value);
 537 out_close:
 538         RegCloseKey(key);
 539 out_done:
 540
 541         return ret;
 542 }