reactos/lib/drivers/sound/mment4/registry.c

   1 /*
   2  * PROJECT:     ReactOS Sound System "MME Buddy" NT4 Library
   3  * LICENSE:     GPL - See COPYING in the top level directory
   4  * FILE:        lib/drivers/sound/mment4/registry.c
   5  *
   6  * PURPOSE:     Registry operation helper for audio device drivers.
   7  *
   8  * PROGRAMMERS: Andrew Greenwood (silverblade@reactos.org)
   9 */
  10
  11 #include <windows.h>
  12 #include <mmsystem.h>
  13 #include <mmddk.h>
  14 #include <ntddsnd.h>
  15
  16 #include <mmebuddy.h>
  17 #include <mment4.h>
  18
  19 /*
  20     Open the parameters key of a sound driver.
  21     NT4 only.
  22 */
  23 MMRESULT
  24 OpenSoundDriverParametersRegKey(
  25     IN  LPWSTR ServiceName,
  26     OUT PHKEY KeyHandle)
  27 {
  28     ULONG KeyLength;
  29     PWCHAR ParametersKeyName;
  30
  31     VALIDATE_MMSYS_PARAMETER( ServiceName );
  32     VALIDATE_MMSYS_PARAMETER( KeyHandle );
  33
  34     /* Work out how long the string will be */
  35     KeyLength = wcslen(REG_SERVICES_KEY_NAME_U) + 1
  36               + wcslen(ServiceName) + 1
  37               + wcslen(REG_PARAMETERS_KEY_NAME_U);
  38
  39     /* Allocate memory for the string */
  40     ParametersKeyName = AllocateWideString(KeyLength);
  41
  42     if ( ! ParametersKeyName )
  43         return MMSYSERR_NOMEM;
  44
  45     /* Construct the registry path */
  46     wsprintf(ParametersKeyName,
  47              L"%s\\%s\\%s",
  48              REG_SERVICES_KEY_NAME_U,
  49              ServiceName,
  50              REG_PARAMETERS_KEY_NAME_U);
  51
  52     SND_TRACE(L"Opening reg key: %wS\n", ParametersKeyName);
  53
  54     /* Perform the open */
  55     if ( RegOpenKeyEx(HKEY_LOCAL_MACHINE,
  56                       ParametersKeyName,
  57                       0,
  58                       KEY_READ,
  59                       KeyHandle) != ERROR_SUCCESS )
  60     {
  61         /* Couldn't open the key */
  62         SND_ERR(L"Failed to open reg key: %wS\n", ParametersKeyName);
  63         FreeMemory(ParametersKeyName);
  64         return MMSYSERR_ERROR;
  65     }
  66
  67     FreeMemory(ParametersKeyName);
  68
  69     return MMSYSERR_NOERROR;
  70 }
  71
  72 /*
  73     Open one of the Device sub-keys belonging to the sound driver.
  74     NT4 only.
  75 */
  76 MMRESULT
  77 OpenSoundDeviceRegKey(
  78     IN  LPWSTR ServiceName,
  79     IN  DWORD DeviceIndex,
  80     OUT PHKEY KeyHandle)
  81 {
  82     DWORD PathLength;
  83     PWCHAR RegPath;
  84
  85     VALIDATE_MMSYS_PARAMETER( ServiceName );
  86     VALIDATE_MMSYS_PARAMETER( KeyHandle );
  87
  88     /*
  89         Work out the space required to hold the path:
  90
  91         HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
  92             sndblst\
  93                 Parameters\
  94                     Device123\
  95     */
  96     PathLength = wcslen(REG_SERVICES_KEY_NAME_U) + 1
  97                + wcslen(ServiceName) + 1
  98                + wcslen(REG_PARAMETERS_KEY_NAME_U) + 1
  99                + wcslen(REG_DEVICE_KEY_NAME_U)
 100                + GetDigitCount(DeviceIndex);
 101
 102     /* Allocate storage for the string */
 103     RegPath = AllocateWideString(PathLength);
 104
 105     if ( ! RegPath )
 106     {
 107         return MMSYSERR_NOMEM;
 108     }
 109
 110     /* Write the path */
 111     wsprintf(RegPath,
 112              L"%ls\\%ls\\%ls\\%ls%d",
 113              REG_SERVICES_KEY_NAME_U,
 114              ServiceName,
 115              REG_PARAMETERS_KEY_NAME_U,
 116              REG_DEVICE_KEY_NAME_U,
 117              DeviceIndex);
 118
 119     SND_TRACE(L"Opening reg key: %wS\n", RegPath);
 120
 121     /* Perform the open */
 122     if ( RegOpenKeyEx(HKEY_LOCAL_MACHINE,
 123                       RegPath,
 124                       0,
 125                       KEY_READ,
 126                       KeyHandle) != ERROR_SUCCESS )
 127     {
 128         /* Couldn't open the key */
 129         SND_ERR(L"Failed to open reg key: %wS\n", RegPath);
 130         FreeMemory(RegPath);
 131         return MMSYSERR_ERROR;
 132     }
 133
 134     FreeMemory(RegPath);
 135
 136     return MMSYSERR_NOERROR;
 137 }