base.c

Go to the documentation of this file.

/****************************** Module Header ******************************\
* Module Name: base.c
*
* Copyright (c) 1985 - 1999, Microsoft Corporation
*
* Contains private versions of routines that used to be in kernel32.dll
*
* History:
* 12-16-94 JimA         Created.
\***************************************************************************/

#include "precomp.h"
#pragma hdrstop

#include <ntddbeep.h>

/***************************************************************************\
* RtlLoadStringOrError
*
* NOTE: Passing a NULL value for lpch returns the string length. (WRONG!)
*
* Warning: The return count does not include the terminating NULL WCHAR;
*
* History:
* 04-05-91 ScottLu      Fixed - code is now shared between client and server
* 09-24-90 MikeKe       From Win30
* 12-09-94 JimA         Use message table.
\***************************************************************************/

int RtlLoadStringOrError(
    UINT wID,
    LPWSTR lpBuffer,            // Unicode buffer
    int cchBufferMax,           // cch in Unicode buffer
    WORD wLangId)
{
    PMESSAGE_RESOURCE_ENTRY MessageEntry;
    int cch;
    NTSTATUS Status;

    /*
     * Make sure the parms are valid.
     */
    if (!lpBuffer || (cchBufferMax-- == 0))
        return 0;

    cch = 0;

    Status = RtlFindMessage((PVOID)hModuleWin, (ULONG_PTR)RT_MESSAGETABLE,
            wLangId, wID, &MessageEntry);
    if (NT_SUCCESS(Status)) {

        /*
         * Copy out the message.  If the whole thing can be copied,
         * copy two fewer chars so the crlf in the message will be
         * stripped out.
         */
        cch = wcslen((PWCHAR)MessageEntry->Text) - 2;
        if (cch > cchBufferMax)
            cch = cchBufferMax;

        RtlCopyMemory(lpBuffer, (PWCHAR)MessageEntry->Text, cch * sizeof(WCHAR));
    }

    /*
     * Append a NULL.
     */
    lpBuffer[cch] = 0;

    return cch;
}


/***************************************************************************\
* UserSleep
*
* Kernel-mode version of Sleep() that must have a timeout value and
* is not alertable.
*
* History:
* 12-11-94 JimA         Created.
\***************************************************************************/

VOID UserSleep(
    DWORD dwMilliseconds)
{
    LARGE_INTEGER TimeOut;

    TimeOut.QuadPart = Int32x32To64( dwMilliseconds, -10000 );
    KeDelayExecutionThread(UserMode, FALSE, &TimeOut);
}


/***************************************************************************\
* UserBeep
*
* Kernel-mode version of Beep().
*
* History:
* 12-16-94 JimA         Created.
\***************************************************************************/

BOOL UserBeep(
    DWORD dwFreq,
    DWORD dwDuration)
{
    OBJECT_ATTRIBUTES ObjectAttributes;
    UNICODE_STRING NameString;
    NTSTATUS Status;
    IO_STATUS_BLOCK IoStatus;
    BEEP_SET_PARAMETERS BeepParameters;
    HANDLE hBeepDevice;
    LARGE_INTEGER TimeOut;

    CheckCritOut();

    if (gbRemoteSession) {
        if (gpRemoteBeepDevice == NULL)
            Status = STATUS_UNSUCCESSFUL;
        else
            Status = ObOpenObjectByPointer(
                          gpRemoteBeepDevice,
                          0,
                          NULL,
                          EVENT_ALL_ACCESS,
                          NULL,
                          KernelMode,
                          &hBeepDevice);
    } else {
        
        RtlInitUnicodeString(&NameString, DD_BEEP_DEVICE_NAME_U);
        
        InitializeObjectAttributes(&ObjectAttributes,
                                   &NameString,
                                   0,
                                   NULL,
                                   NULL);
        
        Status = ZwCreateFile(&hBeepDevice,
                              FILE_READ_DATA | FILE_WRITE_DATA,
                              &ObjectAttributes,
                              &IoStatus,
                              NULL,
                              0,
                              FILE_SHARE_READ | FILE_SHARE_WRITE,
                              FILE_OPEN_IF,
                              0,
                              (PVOID) NULL,
                              0L);
    }
    
    if (!NT_SUCCESS(Status)) {
        return FALSE;
    }

    /*
     * 0,0 is a special case used to turn off a beep.  Otherwise
     * validate the dwFreq parameter to be in range.
     */
    if ((dwFreq != 0 || dwDuration != 0) &&
        (dwFreq < (ULONG)0x25 || dwFreq > (ULONG)0x7FFF)) {
        
        Status = STATUS_INVALID_PARAMETER;
    } else {
        BeepParameters.Frequency = dwFreq;
        BeepParameters.Duration = dwDuration;

        Status = ZwDeviceIoControlFile(hBeepDevice,
                                       NULL,
                                       NULL,
                                       NULL,
                                       &IoStatus,
                                       IOCTL_BEEP_SET,
                                       &BeepParameters,
                                       sizeof(BeepParameters),
                                       NULL,
                                       0);
    }

    EnterCrit();
    _UserSoundSentryWorker();
    LeaveCrit();

    if (!NT_SUCCESS(Status)) {
        ZwClose(hBeepDevice);
        return FALSE;
    }
    
    /*
     * Beep device is asynchronous, so sleep for duration
     * to allow this beep to complete.
     */
    if (dwDuration != (DWORD)-1 && (dwFreq != 0 || dwDuration != 0)) {
        TimeOut.QuadPart = Int32x32To64( dwDuration, -10000);
        
        do {
            Status = KeDelayExecutionThread(UserMode, FALSE, &TimeOut);
        }
        while (Status == STATUS_ALERTED);
    }
    ZwClose(hBeepDevice);
    return TRUE;
}

void RtlInitUnicodeStringOrId(
    PUNICODE_STRING pstrName,
    LPWSTR lpstrName)
{
    if (IS_PTR(lpstrName)) {
        RtlInitUnicodeString(pstrName, lpstrName);
    } else {
        pstrName->Length = pstrName->MaximumLength = 0;
        pstrName->Buffer = lpstrName;
    }
}

---