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 <config.h>
  22 #include "libserialport.h"
  23 #include "libserialport_internal.h"
  24
  25 /* USB path is a string of at most 8 decimal numbers < 128 separated by dots. */
  26 #define MAX_USB_PATH ((8 * 3) + (7 * 1) + 1)
  27
  28 static void enumerate_hub(struct sp_port *port, const char *hub_name,
  29                           const char *parent_path);
  30
  31 static char *wc_to_utf8(PWCHAR wc_buffer, ULONG size)
  32 {
  33         WCHAR wc_str[(size / sizeof(WCHAR)) + 1];
  34         char *utf8_str;
  35
  36         /* Zero-terminate the wide char string. */
  37         memcpy(wc_str, wc_buffer, size);
  38         wc_str[sizeof(wc_str) - 1] = 0;
  39
  40         /* Compute the size of the UTF-8 converted string. */
  41         if (!(size = WideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, wc_str, -1,
  42                                          NULL, 0, NULL, NULL)))
  43                 return NULL;
  44
  45         /* Allocate UTF-8 output buffer. */
  46         if (!(utf8_str = malloc(size)))
  47                 return NULL;
  48
  49         /* Actually converted to UTF-8. */
  50         if (!WideCharToMultiByte(CP_ACP, WC_NO_BEST_FIT_CHARS, wc_str, -1,
  51                                  utf8_str, size, NULL, NULL)) {
  52                 free(utf8_str);
  53                 return NULL;
  54         }
  55
  56         return utf8_str;
  57 }
  58
  59 static char *get_root_hub_name(HANDLE host_controller)
  60 {
  61         USB_ROOT_HUB_NAME root_hub_name;
  62         PUSB_ROOT_HUB_NAME root_hub_name_wc;
  63         char *root_hub_name_utf8;
  64         ULONG size = 0;
  65
  66         /* Compute the size of the root hub name string. */
  67         if (!DeviceIoControl(host_controller, IOCTL_USB_GET_ROOT_HUB_NAME, 0, 0,
  68                              &root_hub_name, sizeof(root_hub_name), &size, NULL))
  69                 return NULL;
  70
  71         /* Allocate wide char root hub name string. */
  72         size = root_hub_name.ActualLength;
  73         if (!(root_hub_name_wc = malloc(size)))
  74                 return NULL;
  75
  76         /* Actually get the root hub name string. */
  77         if (!DeviceIoControl(host_controller, IOCTL_USB_GET_ROOT_HUB_NAME,
  78                              NULL, 0, root_hub_name_wc, size, &size, NULL)) {
  79                 free(root_hub_name_wc);
  80                 return NULL;
  81         }
  82
  83         /* Convert the root hub name string to UTF-8. */
  84         root_hub_name_utf8 = wc_to_utf8(root_hub_name_wc->RootHubName, size);
  85         free(root_hub_name_wc);
  86         return root_hub_name_utf8;
  87 }
  88
  89 static char *get_external_hub_name(HANDLE hub, ULONG connection_index)
  90 {
  91         USB_NODE_CONNECTION_NAME ext_hub_name;
  92         PUSB_NODE_CONNECTION_NAME ext_hub_name_wc;
  93         char *ext_hub_name_utf8;
  94         ULONG size;
  95
  96         /* Compute the size of the external hub name string. */
  97         ext_hub_name.ConnectionIndex = connection_index;
  98         if (!DeviceIoControl(hub, IOCTL_USB_GET_NODE_CONNECTION_NAME,
  99                              &ext_hub_name, sizeof(ext_hub_name),
 100                              &ext_hub_name, sizeof(ext_hub_name), &size, NULL))
 101                 return NULL;
 102
 103         /* Allocate wide char external hub name string. */
 104         size = ext_hub_name.ActualLength;
 105         if (size <= sizeof(ext_hub_name)
 106             || !(ext_hub_name_wc = malloc(size)))
 107                 return NULL;
 108
 109         /* Get the name of the external hub attached to the specified port. */
 110         ext_hub_name_wc->ConnectionIndex = connection_index;
 111         if (!DeviceIoControl(hub, IOCTL_USB_GET_NODE_CONNECTION_NAME,
 112                              ext_hub_name_wc, size,
 113                              ext_hub_name_wc, size, &size, NULL)) {
 114                 free(ext_hub_name_wc);
 115                 return NULL;
 116         }
 117
 118         /* Convert the external hub name string to UTF-8. */
 119         ext_hub_name_utf8 = wc_to_utf8(ext_hub_name_wc->NodeName, size);
 120         free(ext_hub_name_wc);
 121         return ext_hub_name_utf8;
 122 }
 123
 124 static char *get_string_descriptor(HANDLE hub_device, ULONG connection_index,
 125                                    UCHAR descriptor_index)
 126 {
 127         char desc_req_buf[sizeof(USB_DESCRIPTOR_REQUEST) +
 128                           MAXIMUM_USB_STRING_LENGTH] = { 0 };
 129         PUSB_DESCRIPTOR_REQUEST desc_req = (void *)desc_req_buf;
 130         PUSB_STRING_DESCRIPTOR desc = (void *)(desc_req + 1);
 131         ULONG size = sizeof(desc_req_buf);
 132
 133         desc_req->ConnectionIndex = connection_index;
 134         desc_req->SetupPacket.wValue = (USB_STRING_DESCRIPTOR_TYPE << 8)
 135                                        | descriptor_index;
 136         desc_req->SetupPacket.wIndex = 0;
 137         desc_req->SetupPacket.wLength = size - sizeof(*desc_req);
 138
 139         if (!DeviceIoControl(hub_device,
 140                              IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION,
 141                              desc_req, size, desc_req, size, &size, NULL)
 142             || size < 2
 143             || desc->bDescriptorType != USB_STRING_DESCRIPTOR_TYPE
 144             || desc->bLength != size - sizeof(*desc_req)
 145             || desc->bLength % 2)
 146                 return NULL;
 147
 148         return wc_to_utf8(desc->bString, desc->bLength);
 149 }
 150
 151 static void enumerate_hub_ports(struct sp_port *port, HANDLE hub_device,
 152                                 ULONG nb_ports, const char *parent_path)
 153 {
 154         char path[MAX_USB_PATH];
 155         ULONG index = 0;
 156
 157         for (index = 1; index <= nb_ports; index++) {
 158                 PUSB_NODE_CONNECTION_INFORMATION_EX connection_info_ex;
 159                 ULONG size = sizeof(*connection_info_ex) + (30 * sizeof(USB_PIPE_INFO));
 160
 161                 if (!(connection_info_ex = malloc(size)))
 162                         break;
 163
 164                 connection_info_ex->ConnectionIndex = index;
 165                 if (!DeviceIoControl(hub_device,
 166                                      IOCTL_USB_GET_NODE_CONNECTION_INFORMATION_EX,
 167                                      connection_info_ex, size,
 168                                      connection_info_ex, size, &size, NULL)) {
 169                         /*
 170                          * Try to get CONNECTION_INFORMATION if
 171                          * CONNECTION_INFORMATION_EX did not work.
 172                          */
 173                         PUSB_NODE_CONNECTION_INFORMATION connection_info;
 174
 175                         size = sizeof(*connection_info) + (30 * sizeof(USB_PIPE_INFO));
 176                         if (!(connection_info = malloc(size))) {
 177                                 free(connection_info_ex);
 178                                 continue;
 179                         }
 180                         connection_info->ConnectionIndex = index;
 181                         if (!DeviceIoControl(hub_device,
 182                                              IOCTL_USB_GET_NODE_CONNECTION_INFORMATION,
 183                                              connection_info, size,
 184                                              connection_info, size, &size, NULL)) {
 185                                 free(connection_info);
 186                                 free(connection_info_ex);
 187                                 continue;
 188                         }
 189
 190                         connection_info_ex->ConnectionIndex = connection_info->ConnectionIndex;
 191                         connection_info_ex->DeviceDescriptor = connection_info->DeviceDescriptor;
 192                         connection_info_ex->DeviceIsHub = connection_info->DeviceIsHub;
 193                         connection_info_ex->DeviceAddress = connection_info->DeviceAddress;
 194                         free(connection_info);
 195                 }
 196
 197                 if (connection_info_ex->DeviceIsHub) {
 198                         /* Recursively enumerate external hub. */
 199                         PCHAR ext_hub_name;
 200                         if ((ext_hub_name = get_external_hub_name(hub_device, index))) {
 201                                 snprintf(path, sizeof(path), "%s%ld.",
 202                                          parent_path, connection_info_ex->ConnectionIndex);
 203                                 enumerate_hub(port, ext_hub_name, path);
 204                         }
 205                         free(connection_info_ex);
 206                 } else {
 207                         snprintf(path, sizeof(path), "%s%ld",
 208                                  parent_path, connection_info_ex->ConnectionIndex);
 209
 210                         /* Check if this device is the one we search for. */
 211                         if (strcmp(path, port->usb_path)) {
 212                                 free(connection_info_ex);
 213                                 continue;
 214                         }
 215
 216                         /* Finally grab detailed information regarding the device. */
 217                         port->usb_address = connection_info_ex->DeviceAddress + 1;
 218                         port->usb_vid = connection_info_ex->DeviceDescriptor.idVendor;
 219                         port->usb_pid = connection_info_ex->DeviceDescriptor.idProduct;
 220
 221                         if (connection_info_ex->DeviceDescriptor.iManufacturer)
 222                                 port->usb_manufacturer = get_string_descriptor(hub_device,index,
 223                                            connection_info_ex->DeviceDescriptor.iManufacturer);
 224                         if (connection_info_ex->DeviceDescriptor.iProduct)
 225                                 port->usb_product = get_string_descriptor(hub_device, index,
 226                                            connection_info_ex->DeviceDescriptor.iProduct);
 227                         if (connection_info_ex->DeviceDescriptor.iSerialNumber)
 228                                 port->usb_serial = get_string_descriptor(hub_device, index,
 229                                            connection_info_ex->DeviceDescriptor.iSerialNumber);
 230
 231                         free(connection_info_ex);
 232                         break;
 233                 }
 234         }
 235 }
 236
 237 static void enumerate_hub(struct sp_port *port, const char *hub_name,
 238                           const char *parent_path)
 239 {
 240         USB_NODE_INFORMATION hub_info;
 241         HANDLE hub_device;
 242         ULONG size = sizeof(hub_info);
 243         char *device_name;
 244
 245         /* Open the hub with its full name. */
 246         if (!(device_name = malloc(strlen("\\\\.\\") + strlen(hub_name) + 1)))
 247                 return;
 248         strcpy(device_name, "\\\\.\\");
 249         strcat(device_name, hub_name);
 250         hub_device = CreateFile(device_name, GENERIC_WRITE, FILE_SHARE_WRITE,
 251                                 NULL, OPEN_EXISTING, 0, NULL);
 252         free(device_name);
 253         if (hub_device == INVALID_HANDLE_VALUE)
 254                 return;
 255
 256         /* Get the number of ports of the hub. */
 257         if (DeviceIoControl(hub_device, IOCTL_USB_GET_NODE_INFORMATION,
 258                             &hub_info, size, &hub_info, size, &size, NULL))
 259                 /* Enumerate the ports of the hub. */
 260                 enumerate_hub_ports(port, hub_device,
 261                    hub_info.u.HubInformation.HubDescriptor.bNumberOfPorts, parent_path);
 262
 263         CloseHandle(hub_device);
 264 }
 265
 266 static void enumerate_host_controller(struct sp_port *port,
 267                                       HANDLE host_controller_device)
 268 {
 269         char *root_hub_name;
 270
 271         if ((root_hub_name = get_root_hub_name(host_controller_device))) {
 272                 enumerate_hub(port, root_hub_name, "");
 273                 free(root_hub_name);
 274         }
 275 }
 276
 277 static void get_usb_details(struct sp_port *port, DEVINST dev_inst_match)
 278 {
 279         HDEVINFO device_info;
 280         SP_DEVINFO_DATA device_info_data;
 281         ULONG i, size = 0;
 282
 283         device_info = SetupDiGetClassDevs(&GUID_CLASS_USB_HOST_CONTROLLER, NULL, NULL,
 284                                           DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
 285         device_info_data.cbSize = sizeof(device_info_data);
 286
 287         for (i = 0; SetupDiEnumDeviceInfo(device_info, i, &device_info_data); i++) {
 288                 SP_DEVICE_INTERFACE_DATA device_interface_data;
 289                 PSP_DEVICE_INTERFACE_DETAIL_DATA device_detail_data;
 290                 DEVINST dev_inst = dev_inst_match;
 291                 HANDLE host_controller_device;
 292
 293                 device_interface_data.cbSize = sizeof(device_interface_data);
 294                 if (!SetupDiEnumDeviceInterfaces(device_info, 0,
 295                                                  &GUID_CLASS_USB_HOST_CONTROLLER,
 296                                                  i, &device_interface_data))
 297                         continue;
 298
 299                 if (!SetupDiGetDeviceInterfaceDetail(device_info,&device_interface_data,
 300                                                      NULL, 0, &size, NULL)
 301                     && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
 302                         continue;
 303
 304                 if (!(device_detail_data = malloc(size)))
 305                         continue;
 306                 device_detail_data->cbSize = sizeof(*device_detail_data);
 307                 if (!SetupDiGetDeviceInterfaceDetail(device_info,&device_interface_data,
 308                                                      device_detail_data, size, &size,
 309                                                      NULL)) {
 310                         free(device_detail_data);
 311                         continue;
 312                 }
 313
 314                 while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS
 315                        && dev_inst != device_info_data.DevInst) { }
 316                 if (dev_inst != device_info_data.DevInst) {
 317                         free(device_detail_data);
 318                         continue;
 319                 }
 320
 321                 port->usb_bus = i + 1;
 322
 323                 host_controller_device = CreateFile(device_detail_data->DevicePath,
 324                                                     GENERIC_WRITE, FILE_SHARE_WRITE,
 325                                                     NULL, OPEN_EXISTING, 0, NULL);
 326                 if (host_controller_device != INVALID_HANDLE_VALUE) {
 327                         enumerate_host_controller(port, host_controller_device);
 328                         CloseHandle(host_controller_device);
 329                 }
 330                 free(device_detail_data);
 331         }
 332
 333         SetupDiDestroyDeviceInfoList(device_info);
 334         return;
 335 }
 336
 337 SP_PRIV enum sp_return get_port_details(struct sp_port *port)
 338 {
 339         /*
 340          * Description limited to 127 char, anything longer
 341          * would not be user friendly anyway.
 342          */
 343         char description[128];
 344         SP_DEVINFO_DATA device_info_data = { .cbSize = sizeof(device_info_data) };
 345         HDEVINFO device_info;
 346         int i;
 347
 348         device_info = SetupDiGetClassDevs(NULL, 0, 0,
 349                                           DIGCF_PRESENT | DIGCF_ALLCLASSES);
 350         if (device_info == INVALID_HANDLE_VALUE)
 351                 RETURN_FAIL("SetupDiGetClassDevs() failed");
 352
 353         for (i = 0; SetupDiEnumDeviceInfo(device_info, i, &device_info_data); i++) {
 354                 HKEY device_key;
 355                 DEVINST dev_inst;
 356                 char value[8], class[16];
 357                 DWORD size, type;
 358                 CONFIGRET cr;
 359
 360                 /* Check if this is the device we are looking for. */
 361                 device_key = SetupDiOpenDevRegKey(device_info, &device_info_data,
 362                                                   DICS_FLAG_GLOBAL, 0,
 363                                                   DIREG_DEV, KEY_QUERY_VALUE);
 364                 if (device_key == INVALID_HANDLE_VALUE)
 365                         continue;
 366                 size = sizeof(value);
 367                 if (RegQueryValueExA(device_key, "PortName", NULL, &type, (LPBYTE)value,
 368                                      &size) != ERROR_SUCCESS || type != REG_SZ) {
 369                         RegCloseKey(device_key);
 370                         continue;
 371                 }
 372                 RegCloseKey(device_key);
 373                 value[sizeof(value)-1] = 0;
 374                 if (strcmp(value, port->name))
 375                         continue;
 376
 377                 /* Check port transport type. */
 378                 dev_inst = device_info_data.DevInst;
 379                 size = sizeof(class);
 380                 cr = CR_FAILURE;
 381                 while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS &&
 382                        (cr = CM_Get_DevNode_Registry_PropertyA(dev_inst,
 383                                  CM_DRP_CLASS, 0, class, &size, 0)) != CR_SUCCESS) { }
 384                 if (cr == CR_SUCCESS) {
 385                         if (!strcmp(class, "USB"))
 386                                 port->transport = SP_TRANSPORT_USB;
 387                 }
 388
 389                 /* Get port description (friendly name). */
 390                 dev_inst = device_info_data.DevInst;
 391                 size = sizeof(description);
 392                 while ((cr = CM_Get_DevNode_Registry_PropertyA(dev_inst,
 393                           CM_DRP_FRIENDLYNAME, 0, description, &size, 0)) != CR_SUCCESS
 394                        && CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS) { }
 395                 if (cr == CR_SUCCESS)
 396                         port->description = strdup(description);
 397
 398                 /* Get more informations for USB connected ports. */
 399                 if (port->transport == SP_TRANSPORT_USB) {
 400                         char usb_path[MAX_USB_PATH] = "", tmp[MAX_USB_PATH];
 401                         char device_id[MAX_DEVICE_ID_LEN];
 402
 403                         /* Recurse over parents to build the USB device path. */
 404                         dev_inst = device_info_data.DevInst;
 405                         do {
 406                                 /* Verify that this layer of the tree is USB related. */
 407                                 if (CM_Get_Device_IDA(dev_inst, device_id,
 408                                                       sizeof(device_id), 0) != CR_SUCCESS
 409                                     || strncmp(device_id, "USB\\", 4))
 410                                         continue;
 411
 412                                 /* Discard one layer for composite devices. */
 413                                 char compat_ids[512], *p = compat_ids;
 414                                 size = sizeof(compat_ids);
 415                                 if (CM_Get_DevNode_Registry_PropertyA(dev_inst,
 416                                                                       CM_DRP_COMPATIBLEIDS, 0,
 417                                                                       &compat_ids,
 418                                                                       &size, 0) == CR_SUCCESS) {
 419                                         while (*p) {
 420                                                 if (!strncmp(p, "USB\\COMPOSITE", 13))
 421                                                         break;
 422                                                 p += strlen(p) + 1;
 423                                         }
 424                                         if (*p)
 425                                                 continue;
 426                                 }
 427
 428                                 /* Stop the recursion when reaching the USB root. */
 429                                 if (!strncmp(device_id, "USB\\ROOT", 8))
 430                                         break;
 431
 432                                 /* Prepend the address of current USB layer to the USB path. */
 433                                 DWORD address;
 434                                 size = sizeof(address);
 435                                 if (CM_Get_DevNode_Registry_PropertyA(dev_inst, CM_DRP_ADDRESS,
 436                                                         0, &address, &size, 0) == CR_SUCCESS) {
 437                                         strcpy(tmp, usb_path);
 438                                         snprintf(usb_path, sizeof(usb_path), "%d%s%s",
 439                                                  (int)address, *tmp ? "." : "", tmp);
 440                                 }
 441                         } while (CM_Get_Parent(&dev_inst, dev_inst, 0) == CR_SUCCESS);
 442
 443                         port->usb_path = strdup(usb_path);
 444
 445                         /* Wake up the USB device to be able to read string descriptor. */
 446                         char *escaped_port_name;
 447                         HANDLE handle;
 448                         if (!(escaped_port_name = malloc(strlen(port->name) + 5)))
 449                                 RETURN_ERROR(SP_ERR_MEM, "Escaped port name malloc failed");
 450                         sprintf(escaped_port_name, "\\\\.\\%s", port->name);
 451                         handle = CreateFile(escaped_port_name, GENERIC_READ, 0, 0,
 452                                             OPEN_EXISTING,
 453                                             FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, 0);
 454                         free(escaped_port_name);
 455                         CloseHandle(handle);
 456
 457                         /* Retrieve USB device details from the device descriptor. */
 458                         get_usb_details(port, device_info_data.DevInst);
 459                 }
 460                 break;
 461         }
 462
 463         SetupDiDestroyDeviceInfoList(device_info);
 464
 465         RETURN_OK();
 466 }
 467
 468 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 469 {
 470         HKEY key;
 471         TCHAR *value, *data;
 472         DWORD max_value_len, max_data_size, max_data_len;
 473         DWORD value_len, data_size, data_len;
 474         DWORD type, index = 0;
 475         char *name;
 476         int name_len;
 477         int ret = SP_OK;
 478
 479         DEBUG("Opening registry key");
 480         if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
 481                         0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS) {
 482                 SET_FAIL(ret, "RegOpenKeyEx() failed");
 483                 goto out_done;
 484         }
 485         DEBUG("Querying registry key value and data sizes");
 486         if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 487                                 &max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS) {
 488                 SET_FAIL(ret, "RegQueryInfoKey() failed");
 489                 goto out_close;
 490         }
 491         max_data_len = max_data_size / sizeof(TCHAR);
 492         if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR)))) {
 493                 SET_ERROR(ret, SP_ERR_MEM, "Registry value malloc failed");
 494                 goto out_close;
 495         }
 496         if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR)))) {
 497                 SET_ERROR(ret, SP_ERR_MEM, "Registry data malloc failed");
 498                 goto out_free_value;
 499         }
 500         DEBUG("Iterating over values");
 501         while (
 502                 value_len = max_value_len + 1,
 503                 data_size = max_data_size,
 504                 RegEnumValue(key, index, value, &value_len,
 505                         NULL, &type, (LPBYTE)data, &data_size) == ERROR_SUCCESS)
 506         {
 507                 if (type == REG_SZ) {
 508                         data_len = data_size / sizeof(TCHAR);
 509                         data[data_len] = '\0';
 510 #ifdef UNICODE
 511                         name_len = WideCharToMultiByte(CP_ACP, 0, data, -1, NULL, 0, NULL, NULL);
 512 #else
 513                         name_len = data_len + 1;
 514 #endif
 515                         if (!(name = malloc(name_len))) {
 516                                 SET_ERROR(ret, SP_ERR_MEM, "Registry port name malloc failed");
 517                                 goto out;
 518                         }
 519 #ifdef UNICODE
 520                         WideCharToMultiByte(CP_ACP, 0, data, -1, name, name_len, NULL, NULL);
 521 #else
 522                         strcpy(name, data);
 523 #endif
 524                         DEBUG_FMT("Found port %s", name);
 525                         if (!(*list = list_append(*list, name))) {
 526                                 SET_ERROR(ret, SP_ERR_MEM, "List append failed");
 527                                 free(name);
 528                                 goto out;
 529                         }
 530                         free(name);
 531                 }
 532                 index++;
 533         }
 534 out:
 535         free(data);
 536 out_free_value:
 537         free(value);
 538 out_close:
 539         RegCloseKey(key);
 540 out_done:
 541
 542         return ret;
 543 }