[PATCH 5/6] winealsa: Rewrite get_reg_devices() using the Nt registry api.

[Andrew Eikum]

Signed-off-by: Andrew Eikum <aeikum at codeweavers.com>

On Tue, Feb 15, 2022 at 01:09:52PM +0000, Huw Davies wrote:
> This code will move to the unixlib.
> 
> Signed-off-by: Huw Davies <huw at codeweavers.com>
> ---
>  dlls/winealsa.drv/mmdevdrv.c | 96 ++++++++++++++++++++++++++++++------
>  1 file changed, 82 insertions(+), 14 deletions(-)
> 
> diff --git a/dlls/winealsa.drv/mmdevdrv.c b/dlls/winealsa.drv/mmdevdrv.c
> index a6ca3827e5f..9a8f80a7beb 100644
> --- a/dlls/winealsa.drv/mmdevdrv.c
> +++ b/dlls/winealsa.drv/mmdevdrv.c
> @@ -166,7 +166,7 @@ static const char defname[] = "default";
>  
>  static const WCHAR drv_keyW[] = {'S','o','f','t','w','a','r','e','\\',
>      'W','i','n','e','\\','D','r','i','v','e','r','s','\\',
> -    'w','i','n','e','a','l','s','a','.','d','r','v',0};
> +    'w','i','n','e','a','l','s','a','.','d','r','v'};
>  static const WCHAR drv_key_devicesW[] = {'S','o','f','t','w','a','r','e','\\',
>      'W','i','n','e','\\','D','r','i','v','e','r','s','\\',
>      'w','i','n','e','a','l','s','a','.','d','r','v','\\','d','e','v','i','c','e','s',0};
> @@ -351,6 +351,73 @@ static void get_device_guid(EDataFlow flow, const char *device, GUID *guid)
>          RegCloseKey(key);
>  }
>  
> +static inline void ascii_to_unicode( WCHAR *dst, const char *src, size_t len )
> +{
> +    while (len--) *dst++ = (unsigned char)*src++;
> +}
> +
> +static HKEY reg_open_key( HKEY root, const WCHAR *name, ULONG name_len )
> +{
> +    UNICODE_STRING nameW = { name_len, name_len, (WCHAR *)name };
> +    OBJECT_ATTRIBUTES attr;
> +    HANDLE ret;
> +
> +    attr.Length = sizeof(attr);
> +    attr.RootDirectory = root;
> +    attr.ObjectName = &nameW;
> +    attr.Attributes = 0;
> +    attr.SecurityDescriptor = NULL;
> +    attr.SecurityQualityOfService = NULL;
> +
> +    if (NtOpenKeyEx( &ret, MAXIMUM_ALLOWED, &attr, 0 )) return 0;
> +    return ret;
> +}
> +
> +static HKEY open_hkcu(void)
> +{
> +    char buffer[256];
> +    WCHAR bufferW[256];
> +    DWORD_PTR sid_data[(sizeof(TOKEN_USER) + SECURITY_MAX_SID_SIZE) / sizeof(DWORD_PTR)];
> +    DWORD i, len = sizeof(sid_data);
> +    SID *sid;
> +
> +    if (NtQueryInformationToken( GetCurrentThreadEffectiveToken(), TokenUser, sid_data, len, &len ))
> +        return 0;
> +
> +    sid = ((TOKEN_USER *)sid_data)->User.Sid;
> +    len = sprintf( buffer, "\\Registry\\User\\S-%u-%u", sid->Revision,
> +                 MAKELONG( MAKEWORD( sid->IdentifierAuthority.Value[5], sid->IdentifierAuthority.Value[4] ),
> +                           MAKEWORD( sid->IdentifierAuthority.Value[3], sid->IdentifierAuthority.Value[2] )));
> +    for (i = 0; i < sid->SubAuthorityCount; i++)
> +        len += sprintf( buffer + len, "-%u", sid->SubAuthority[i] );
> +    ascii_to_unicode( bufferW, buffer, len + 1 );
> +
> +    return reg_open_key( NULL, bufferW, len * sizeof(WCHAR) );
> +}
> +
> +static HKEY reg_open_hkcu_key( const WCHAR *name, ULONG name_len )
> +{
> +    HKEY hkcu = open_hkcu(), key;
> +
> +    key = reg_open_key( hkcu, name, name_len );
> +    NtClose( hkcu );
> +
> +    return key;
> +}
> +
> +ULONG reg_query_value( HKEY hkey, const WCHAR *name,
> +                       KEY_VALUE_PARTIAL_INFORMATION *info, ULONG size )
> +{
> +    unsigned int name_size = name ? lstrlenW( name ) * sizeof(WCHAR) : 0;
> +    UNICODE_STRING nameW = { name_size, name_size, (WCHAR *)name };
> +
> +    if (NtQueryValueKey( hkey, &nameW, KeyValuePartialInformation,
> +                         info, size, &size ))
> +        return 0;
> +
> +    return size - FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION, Data);
> +}
> +
>  static snd_pcm_stream_t alsa_get_direction(EDataFlow flow)
>  {
>      return (flow == eRender) ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE;
> @@ -496,27 +563,28 @@ static void get_reg_devices(EDataFlow flow, WCHAR ***ids, GUID **guids, UINT *nu
>  {
>      static const WCHAR ALSAOutputDevices[] = {'A','L','S','A','O','u','t','p','u','t','D','e','v','i','c','e','s',0};
>      static const WCHAR ALSAInputDevices[] = {'A','L','S','A','I','n','p','u','t','D','e','v','i','c','e','s',0};
> +    char buffer[4096];
> +    KEY_VALUE_PARTIAL_INFORMATION *key_info = (void *)buffer;
>      HKEY key;
> -    WCHAR reg_devices[256];
> -    DWORD size = sizeof(reg_devices), type;
> +    DWORD size;
>      const WCHAR *value_name = (flow == eRender) ? ALSAOutputDevices : ALSAInputDevices;
>  
>      /* @@ Wine registry key: HKCU\Software\Wine\Drivers\winealsa.drv */
> -    if(RegOpenKeyW(HKEY_CURRENT_USER, drv_keyW, &key) == ERROR_SUCCESS){
> -        if(RegQueryValueExW(key, value_name, 0, &type,
> -                    (BYTE*)reg_devices, &size) == ERROR_SUCCESS){
> -            WCHAR *p = reg_devices;
> +    if((key = reg_open_hkcu_key(drv_keyW, sizeof(drv_keyW)))){
> +        if((size = reg_query_value(key, value_name, key_info, sizeof(buffer)))){
> +            WCHAR *p = (WCHAR *)key_info->Data;
>  
> -            if(type != REG_MULTI_SZ){
> +            if(key_info->Type != REG_MULTI_SZ){
>                  ERR("Registry ALSA device list value type must be REG_MULTI_SZ\n");
> -                RegCloseKey(key);
> +                NtClose(key);
>                  return;
>              }
>  
>              while(*p){
> -                char devname[64];
> +                int len = lstrlenW(p);
> +                char *devname = malloc(len * 3 + 1);
>  
> -                WideCharToMultiByte(CP_UNIXCP, 0, p, -1, devname, sizeof(devname), NULL, NULL);
> +                WideCharToMultiByte(CP_UNIXCP, 0, p, -1, devname, len * 3 + 1, NULL, NULL);
>  
>                  if(alsa_try_open(devname, flow)){
>                      if(*num){
> @@ -530,12 +598,12 @@ static void get_reg_devices(EDataFlow flow, WCHAR ***ids, GUID **guids, UINT *nu
>                      get_device_guid(flow, devname, &(*guids)[*num]);
>                      ++*num;
>                  }
> -
> -                p += lstrlenW(p) + 1;
> +                free(devname);
> +                p += len + 1;
>              }
>          }
>  
> -        RegCloseKey(key);
> +        NtClose(key);
>      }
>  }
>  
> -- 
> 2.25.1
> 
>